Calcareous termite mounds in South Africa are ancient carbon reservoirs

Ecosystems that offer carbon sequestration by leaching bicarbonate to groundwater are valuable natural capital. One region that may offer this service is the west coast of South Africa. Over 20 % is covered by soil mounds ("heuweltjies") up to 40 m diameter, 2 m high, inhabited by the southern harvester termite Microhodotermes viator and enriched in soil organic and inorganic carbon and soluble minerals. We aimed to generate radiogenic and stable isotope data for soils and groundwater in a region where these data are absent, to 1) verify the atmosphere-soil-groundwater link, and 2) resolve the timing and pattern of calcite dissolution and water infiltration in the landscape. Results show that soil and groundwater sulfate have the same marine aerosol source. Episodic calcite dissolution in mound centers, which increased during periods of global cooling, has been set against background input of marine aerosols since before the Last Glacial according to radiocarbon (14C) ages. Our data push back soil organic carbon 14C ages of inhabited termite mounds to 13-19 ka (kiloannum, thousand years before present), nest carbonate 14C ages to 33 ka, and mound soil carbonate 14C ages to 34 ka, making these the oldest active termite features ever dated. These ages are consistent with soil organic carbon and carbonate 14C ages of regional, non-mound, coastal petrocalcic horizons formed by accumulation of carbonate leached from their overlying aeolian dune fields. Harvesting activities of termites inject younger organic material around nests >1 m deep, leading to continuous renewal of important soil carbon reservoirs at depth. Termite bioturbation increases the system's ability to dissolve carbonate. The central, bioturbated part of the mounds have greater infiltration depths and greater calcite dissolution, whereas surrounding soils experienced more surface runoff. Calcareous termite mounds offer a mechanism to sequester CO2 through dissolution and leaching of soil carbonate-bicarbonate to groundwater.

Oral Cavity Squamous Cell Carcinomas in Patients with a History of Oral Lichen Planus: Frequency and Outcomes

PURPOSE/OBJECTIVE(S)

Oral lichen planus (OLP) is an inflammatory condition which affects the mucous membranes of the oral cavity. While previous studies have described the association between OLP and development of oral cavity cancer, there is currently a paucity of literature examining the impact of this disease on treatment response and prognosis. As such, we present a retrospective cohort study of Oral cavity squamous cell carcinoma (OCSCC) patients with a history of OLP to explore the course of their disease.

MATERIALS/METHODS

Using an IRB approved tertiary care registry of head and neck cancer patients, we identified patients with OCSCC who had a prior diagnosis of OLP. The number of new primary tumors, rates of local (LF), regional (RF) and distant failure (DF), as well as overall survival (OS) were assessed using Cox proportional hazards and Kaplan Meier analysis for actuarial survival estimates.

RESULTS

Fifty-four patients with OCSCC and OLP were identified with 109 individual OCSCC diagnoses. Patients had a median age of 67 years, were predominantly female (n = 42, 77.8%) and never smokers (n = 29, 53.7%) with a median follow up after diagnosis of OCSCC of 46.5 months. Nine patients (16.7%) had a history of immunosuppression of whom 6 (11.1%) had chronic steroid use for treatment of OLP. Within the cohort, 33 (61.1%) of OLP patients had a single OCSCC, 11 (20.4%) had 2, and 10 (18.5%) had >3 separate tumors develop. The most common oral cavity subsites were oral tongue (n = 42, 38.5%), followed by alveolar ridge (n = 14, 12.8%) and gingiva (n = 13, 11.9%). Papillary SCC subtype was identified in 10.1%. 92.7% of tumors (n = 101) were treated with primary surgery, with 23 (21.1%) receiving adjuvant RT and 10 of those patients receiving concurrent chemotherapy. Among resected patients, pathologic stages were predominantly T1-2 (84.1%) and N0 (50% vs N1 15.6% and N2a-3 34.4%). The mean RT dose was 62 Gy in 32 fractions. Locoregional failure occurred in 24.8% of cancers (n = 27), with local and regional failure occurring in 13.8% (n = 15) and 11% (n = 12) of lesions, respectively. Recurrence free survival at 3 and 5 years was 75% and 70.3%, respectively, with overall survival at 3 and 5 years of 71.1% and 67%, respectively.

CONCLUSION

Patients with OCSCC and a history of OLP are predominantly female and never smokers. The tumors that develop in such patients are often early stage but a proportion of patients appear to be at higher risk of developing multiple malignancies and surveillance of this patient population to identify new tumors is crucial.

Stereotactic Body Radiation Therapy (SBRT) for Head and Neck Cancer Re-Irradiation: Should >180˚ Carotid Encasement or Dermal Involvement Remain an Exclusion Criteria?

PURPOSE/OBJECTIVE(S)

Patients with recurrent head and neck cancer (HNC) who present with carotid encasement (CE) >180˚ and skin involvement/abutment (SI/A) are often not considered for SBRT re-irradiation and are excluded from RTOG 3507. We reviewed our institutional experience of SBRT re-irradiation in such cases.

MATERIALS/METHODS

From an IRB approved registry, we identified previously irradiated HNC patients treated by SBRT with CE >180˚, SI/A, or use of bolus from 2013-2022. Toxicity as per CTCAEv4.0 and recurrence patterns were analyzed. The cumulative incidence of local progression was estimated with death as a competing risk. Survival analysis was performed with the Kaplan-Meier method.

RESULTS

Thirty-five patients were treated with SBRT to 37 sites with median follow up of 5.7 months (mo) (IQR 2.7-10.6). A total of 20 cases exhibited CE >180˚, 20 cases had SI/A, and 3 cases had both. The median time from prior radiation was 12.7 mo (range 1.9-144.1). Histology was squamous cell carcinoma in 89%. The site of SBRT was most commonly the neck (65%), 24% mucosa, 8% skull base, and 3% scalp. SBRT was delivered in 5 fractions every other day (62%) or 2 fractions per week (38%). 78% (N = 29) received ≥40 Gy while 22% (N = 8) received a lower dose. The cumulative incidence of local failure at 3 and 6 mo was 12.4% (95% CI 0.8-24.0) and 31.3% (95% CI 14.9-47.8), respectively. The median time of local and regional recurrence free survival was 7.0 and 4.9 mo. Median OS was 8.3 mo. Of the 20 cases with true SI, 40% (N = 8) completely resolved, 35% (N = 7) improved or had residual ulceration attributed to disease, and 25% (N = 5) had ulceration related to toxicity. There were no carotid bleeding events (CBE) related to SBRT, however 10% (N = 2) experienced fatal CBE related to progressive disease at 2.3 mo and 6.7 mo from SBRT. The rate of grade ≥2 treatment related skin toxicity was 19% (N = 7) and only occurred in those with pre-SBRT SI/A. These included a grade 2 neck wound and tracheostomy infection, a grade 3 infection, and two grade 3 soft tissue necrosis. One patient had cellulitis/meningitis related to scalp radiation, and one had an untreated SBRT wound as they transitioned to hospice. Dysphagia requiring PEG occurred in 5% (N = 2), one of which was related to CNX palsy. Six patients (17%) had post-SBRT nerve impairment including one each of grade 2 facial nerve paralysis, grade 2 brachial plexopathy, grade 3 CNVIII dysfunction, grade 3 CNX impairment, and two patients with grade 2 CNXII impairment.

CONCLUSION

SBRT for locally recurrent previously radiated HNC can provide effective local control in a patient population at high risk of morbidity and mortality from local disease progression. In patients who have >180˚ CE or SI/A, we observed non-trivial toxicity, but disease progression may have been more morbid. For appropriately counseled patients with limited treatment options, CE or SI/A may not be an absolute contraindication to SBRT re-irradiation.

Local Cost-Effectiveness of Nasopharyngeal Carcinoma Screening Strategies in Southern China: Secondary Analysis of the PRO-NPC-001 Cluster-Randomized Trial

PURPOSE/OBJECTIVE(S)

Population-based screening for endemic nasopharyngeal carcinoma (NPC) detects most cases at an early stage. In a cluster-randomized trial conducted in Guangdong, a combination of Epstein-Barr Virus (EBV) anti-VCA/EBNA1 IgA serology and endoscopy reduced NPC mortality. We conducted a secondary analysis of this trial in conjunction with local incidence and cost data, hypothesizing that screening would be cost-effective in this region.

MATERIALS/METHODS

We estimated population-level NPC mortality reduction, resource utilization, and cost-effectiveness of 12 unique screening strategies in six populations in Guangdong/Guangxi using a previously-validated time-inhomogeneous decision-analytic cohort model. These 12 strategies evaluated combinations of serology, nasopharyngeal swab PCR (NP PCR), endoscopy, and head/neck MRI. Incidence data, screening costs, and healthcare costs were obtained from local cancer registries, laboratories conducting ELISA/PCR, and the Guangdong provincial healthcare system. We evaluated variable screening ages, sexes, intervals, and durations to identify optimal screening approaches from the perspective of the healthcare system in southern China. An incremental cost-effectiveness ratio (ICER) willingness-to-pay threshold of 1.50 times the per-capita GDP was considered cost-effective in southern China.

RESULTS

For the base strategy screening 50-year-old men and women using only serology and endoscopy, the average cost per screened subject for a single round of screening over a five-year cycle was ¥175.69. The addition of MRI improved sensitivity (76% vs. 62%) and approximately doubled screening costs. Triage with NP PCR was cost-neutral when used in conjunction with MRI and reduced endoscopy/MRI utilization by 37% with a 3-4% reduction in screening sensitivity. Among 50-year-old men and women, screening was cost-effective in all populations provided that medium-risk subjects were not referred for endoscopy/MRI (ICER/GDP 0.62-0.83). The use of NP PCR without MRI (ICER/GDP 0.83) was dominated by the base strategy (ICER/GDP 0.62) due to higher costs and NPC mortality. After a single five-year screening cycle, screening reduced population NPC mortality by 14% with serology + endoscopy and 21% with serology + endoscopy + MRI. Introduction of MRI with or without NP PCR could be cost-effective in all populations. For MRI-based strategies, the most efficient use of resources was deferral of endoscopy unless MRI was abnormal (ICER/GDP 0.67). Overall, the best-performing strategies balanced NPC mortality, screening costs, and MRI utilization.

CONCLUSION

EBV serology-based screening for endemic NPC is likely to be cost-effective among adult men and women in Guangdong and Guangxi. Referring medium-risk subjects for endoscopy/MRI should be avoided, and NP PCR should be used to triage individuals for MRI rather than endoscopy. These data may aid the design of population-based screening programs in this region.

Definitive Radiotherapy for the Treatment of Gross Disease in Unresected Differentiated Thyroid Cancer

PURPOSE/OBJECTIVE(S)

While surgery (with or without radioactive iodine (RAI)) is the mainstay of locoregional control in differentiated thyroid cancer (DTC), patients with unresectable disease present a clinical challenge. Uncontrolled disease in the neck can lead to substantial morbidity and mortality in DTC and obtaining locoregional control is vital to preserving quality of life and longevity. High dose definitive radiotherapy (RT) for gross disease in DTC is understudied. This study examines the efficacy of definitive RT in this setting.

MATERIALS/METHODS

From an IRB-approved registry of head and neck cancer cases treated at a tertiary care center over a period of 8 years (2014-2022), patients with incompletely resected or unresectable DTC including papillary, follicular, mixed, medullary, and poorly differentiated types were identified. All patients were treated to the neck and/or thyroid regions with visible gross disease to a definitive dose of radiation. The primary endpoint was local control within the radiated portal with a secondary endpoint of locoregional control within the neck.

RESULTS

A total of 31 patients were identified, of whom 74.2% were Caucasian. Fourteen were female (45.2%), and 17 (54.8%) were male. The median age was 68 years (range 26-90) and the median follow-up was 31 months. Histologically, 19 (61.3%) cases were papillary, 4 (12.9%) were follicular, 2 (6.5%) were mixed, 3 (9.7%) were medullary, and 3 (9.7%) were poorly differentiated. Among patients with non-medullary DTC 18 (69.2%) received prior RAI. Twelve patients were treated with radiation at initial diagnosis, while 19 patients were treated at the time of recurrence; two patients received concurrent chemotherapy. Twenty-eight patients (90.3%) were treated with IMRT and 3 (9.7%) were treated with SBRT. The median dose to the gross disease was 66 Gy (range 30-70.4) in 32 fractions (range 5-35). Overall, 5 patients (16.1%) experienced a locoregional failure after RT and all experienced failure in the RT portal. The actuarial infield control/locoregional control of radiation therapy at 3 and 5 years was 84.8% and 74.2%, respectively. Overall survival at 3 and 5 years was 68.5% and 47.4%, respectively. Among patients who had a locoregional failure after RT, 2 patients were salvaged with systemic therapy, 2 patients with surgery, and 1 patient with SBRT re-irradiation (40 Gy/5 fractions). The patient salvaged with SBRT remains without disease 8 months post-RT.

CONCLUSION

Definitive radiotherapy is a highly effective strategy to obtain durable control of unresected DTC. It should be standard for unresected disease and considered as a viable alternative for patients with borderline resectable disease for whom resection would be highly morbid.

Partial Tongue Sparing without Marginal Failures: The Dosimetric Advantages for Oral Tongue Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Due to a lack of internal barriers, many radiation oncologists believe whole tongue (WT) irradiation is warranted in the adjuvant setting for oral tongue cancer. Our institutional practice is to include the resection bed and flap with a 5-10 mm margin, attempting to spare unaffected oral tongue. We hypothesize that partial tongue (PT) irradiation, when feasible, results in decreased dose to surrounding normal structures without an increased risk of local recurrence (LR).

MATERIALS/METHODS

Patients with a new diagnosis of squamous cell carcinoma of the oral tongue treated with adjuvant IMRT between 2010 and 2021 were collected from an IRB approved database. PT was defined as <80% of residual tongue in the clinical target volume (CTV). Recurrence was deemed local if in the tongue or floor of mouth, and in field if within the CTV or marginal if outside of CTV. Mean dose to mandible, pharyngeal constrictors, and oral cavity were evaluated. Comparisons between groups were made using parametric one-way ANOVA. Multivariable linear regression was used to predict mean radiation dose. Local control and overall survival were estimated using Kaplan-Meier.

RESULTS

A total of 130 patients are included with median follow up 34.1 months (IQR 13.5-64.6). Radiation dose was 48-72 Gy in 24-36 fractions, most commonly 60-66 Gy in 30-33 fractions (84.6%). All were treated to oral cavity, and neck irradiation included bilateral 96 (72%), unilateral 31 (24%), and none 3 (4%). PT sparing was feasible in 91 (70%) and 39 (30%) required WT. Primary tumor stage in PT included 20 pT1, 50 pT2, 17 pT3, and 4 pT4, and WT included 3 pT1, 8 pT2, 15 pT3, and 13 pT4. 3-year local control for PT and WT was 96% and 87%, respectively. LR occurred in 14 patients overall (10.8%), 6.6% (6) of patients treated with PT and 20.5% (8) treated with WT (p = 0.072). Of the LR for PT, stage was 2 pT1, 3 pT2, and 1 pT3, and all occurred within the radiation field. Of the LR for WT, stage was 1 each of pT1 and pT2, 2 pT3, and 4 pT4. Overall survival was 57%, regional and distant recurrence was each 17.7%. Dosimetric analysis for PT vs WT is described in Table 1, demonstrating lower mean dose when the primary tumor CTV is limited to PT. Unilateral neck irradiation also resulted in a lower mandible [-8.5 Gy (-11.2 - -5.8)], pharyngeal constrictor [-14.3 Gy (-18.1 - -10.5)], and oral cavity [-9.0 Gy (-13.0 - -5.0)] dose (all p<0.001).

CONCLUSION

Limiting the primary tumor CTV to PT for adjuvant radiotherapy resulted in significant sparing of the mandible and pharyngeal constrictors, and a routinely lower oral cavity mean dose of ≥3.5 Gy. There was a low risk of LR when implementing PT, and all LR occurred in field. Given the increased sparing of normal structures, and low risk of LR outside of PT radiation field, sparing a portion of unaffected oral tongue should be considered.

Phase II Randomized Trial of Single- vs. Two-Fraction Spine Stereotactic Radiosurgery for the Treatment of Vertebral Metastases

PURPOSE/OBJECTIVE(S)

As systemic therapies improve significantly, more patients with limited metastatic disease are undergoing spine stereotactic radiosurgery (sSRS). High dose (≥24 Gy) single fraction sSRS has been associated with a vertebral compression fracture (VCF) risk of up to 40%. Comparatively, lower dose (16-18 Gy) single fraction sSRS is associated with a fracture risk of 15-20%, with the risk increasing as the dose increases. To mitigate the risk of VCF, while optimizing higher dose delivery, some have advocated utilizing two-fraction sSRS regimen. Therefore, we designed a phase II randomized trial in which we hypothesized that single fraction sSRS is non-inferior to two-fraction sSRS with respect to VCF but offers patients greater convenience.

MATERIALS/METHODS

Inclusion criteria include age ≥18, Karnofsky performance score ≥70, vertebral metastasis from C3 to L5, maximum of three separate sites of metastases, limited paraspinal extension (<5 cm), and no rapid neurological decline. Patients must also be either Recursive Partitioning Analysis Class 1 (KPS >70 AND controlled systemic disease) or Class 2 (KPS >70, uncontrolled systemic disease OR KPS ≤70, age ≥54, no visceral metastases). Exclusion criteria include multiple primary cancers, primary neoplasm of the spine, prior surgery at the site of sSRS, spinal cord compression, bony retropulsion resulting in neurologic deficit, inability to undergo/contraindication to MRI, or diffuse multi-level metastatic spine disease. Our primary hypothesis is that single fraction sSRS (experimental arm - 16-18 Gy) is non-inferior to two fraction sSRS (standard arm - 24 Gy). Furthermore, we hypothesize that both treatment arms will have similar local control, pain control, quality of life and toxicity profiles. The primary endpoint of this trial is the development or progression of VCF at 6 months. Secondary endpoints include local control, pain control, quality of life and toxicity all of which will be assessed at 12 months. For the sample size calculation, we assumed a VCF risk of 17% in the experimental arm and a 7% risk in the standard arm. Based on these calculations, we aim to enroll 130 patients, 65 in each arm. This trial is currently enrolling patients actively, and approximately 30% of expected enrollment has been completed to date. This trial is registered on clinicaltrials.gov: NCT04218617.

RESULTS

Pending full accrual.

CONCLUSION

Pending full accrual.

2131. Performance of Dried Blood Spot (DBS) for the Diagnosis of Congenital Cytomegalovirus (cCMV) in a Single Center: A Real-World Experience

Background

The newborn DBS has been used for the retrospective diagnosis as well as a screening method for cCMV. We aimed to assess the sensitivity and specificity of this test compared to traditional methods, for the diagnosis of children suspected to have cCMV in the first 21 DOL.

Methods

In this single-center retrospective cohort study, all patients (N= 304) with a request for DBS testing between 2013 and 2021 were reviewed. Those with a DBS available for testing, a medical record at our institution, and at least one diagnostic test for cCMV obtained within the first 21 days of life (DOL) were included for review (N=86).

DBS were requested from the Texas State Health Department and sent to the Center for Disease Control for testing by DNA CMV PCR.

DBS results were compared to patients whose diagnoses were made via traditional testing with at least one accepted method (urine culture, urine PCR, blood PCR and/or saliva culture) obtained within the first 21 DOL. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

Results

Of the 86 patients included, 59 had a diagnosis of cCMV established by conventional testing, with 50 of them having a positive DBS and 9 a negative result. DBS had a sensitivity of 84.7%, specificity of 100 %, positive predictive value of 100 % and a negative predictive value of 75%.

Those patients with a true positive DBS had a higher median level of viremia by CMV blood PCR (6487 IU/ml vs 471 IU/ml, p= 0.012) when compared to those with a false negative result.

All patients with cCMV and congenital hearing loss had a positive DBS (N=15). A significant difference was noted in the median viremia levels of those patients with cCMV with congenital hearing loss vs those with cCMV without congenital hearing loss (17,547 IU/ml vs 3,175 IU/ml, p=0.012)

Of those cCMV patients that developed late onset hearing loss (N=9), 8 had a true positive DBS and 1 had a false negative result.

Conclusion

DBS could be useful in the diagnosis of cCMV, and its performance may be related to the level of CMV viremia at birth. DBS appears to be able to accurately identify those patients with congenital hearing loss and those who will develop late onset hearing loss. Future studies are needed to determine the best population that can be identified by this test.

Disclosures

Ryan H. Rochat, MD, PhD, MS, Merck Sharpe & Dohme: Grant/Research Support Jerry A. Miller, MS, PhD, CPH, Merck: Grant/Research Support Gail J. Demmler-Harrison, MD, Elsevier: Book royalties|Merck: Grant/Research Support|Microgen: Advisor/Consultant|Microgen: Grant/Research Support|Moderna: Advisor/Consultant|UpToDate Wolters Kluwer Health: Royalties.

Saline groundwater in the Buffels River catchment, Namaqualand, South Africa: A new look at an old problem

Namaqualand, South Africa, is a global biodiversity hotspot but local populations are affected by challenging economic conditions largely because of poor access to water. In this study groundwater types are characterised and sources of salts and salinisation processes are identified using hydrochemistry and δ¹⁸O, δ²H and ⁸⁷Sr/⁸⁶Sr data. Analysis of δ¹⁸O and δ²H data suggests that evaporation does not play a major role in salinisation of the groundwater. However, major ion chemistry and ⁸⁷Sr/⁸⁶Sr ratios indicate that salts present in the groundwater are linked to dry deposition of marine aerosols and ion-exchange reactions in soils in the alluvial aquifer systems. The hydrochemical variability of the groundwater in the basement aquifer system suggests that there are strong local controls linked to weathering processes in individual basement rock types. The region is also notable for the high density of heuweltjies, biophysical features associated with increased nutrient levels, associated with termite activity. Electromagnetic scanning as well as measurement of water-soluble soil electrical conductivity values on and off heuweltjies, show that heuweltjies are saline with salinity increasing with depth. The level of groundwater salinity correlates with the level of heuweltjie salinity. Precipitation records from the last 150 years provide support for the hypothesis that accumulated salts, and in particular, heuweltjie salts are flushed into the groundwater system during sporadic large volume precipitation events. Thus, heuweltjies and hence termite activity, could potentially represent a previously unrecognized contributor to groundwater salinisation across Namaqualand and in other parts of the world.

Spatial and temporal variability of tritium in precipitation within South Africa and it's bearing on hydrological studies

Tritium, the radioactive isotope of hydrogen, has been used to understand groundwater recharge processes for decades. The current variation of tritium in the atmosphere is largely attributed to stratospheric production and fall out rates as well as global circulation phenomena controlling the hydrological cycle. Global controls on the variability in atmospheric tritium activity are poorly suited to explain local variation and tritium activities in precipitation are often assumed to be uniform over both local and regional catchments and watersheds. This assumption can result in both over and under estimation of modern recharge within an aquifer when using tritium as the recharge proxy. In order to minimize the inherent prediction residuals associated with tritium based recharge investigations, the variability of tritium in precipitation was modelled from 127 spatial precipitation samples taken over a two year period, combined with a 76 precipitation sample group-set taken over a one year period in a single location. Precipitation events were traced backward in time, from the point of collection, using HYSPLIT modelling to ascertain the origins of moisture content as well as the altitudes of moisture origin reached along the particle track. Tritium activities, collected over a one year period in Paarl, range from 0.45 to 4.16 TU and have a mean of 1.59 TU. Spatial storm events in the Western Cape in 2017 and 2018 had a range from 0 to 2.2 and 0.37 to 3.27 TU, respectively, with mean activities of 1.18 (n = 34) and 1.25 TU (n = 32). Both storm events had similar tritium variability (σ = 0.5 n = 35 and 0.48 n = 32). Regional precipitation events had the largest range of tritium activities (0.55-12.2 TU). Although not all tritium activities can be explained by interrogating the water mass origin, this study suggests that approximately 90% of events can be completely or partially attributed to the origin of the water mass. The variability of tritium, both spatially and temporally, was higher than expected, confirming that when uniform tritium inputs are used, the groundwater system would provide inaccurate modern recharge estimates. Higher spatial resolution of tritium variation in precipitation for a particular region will improve our ability to relate tritium activities in groundwater to local precipitation.

The Impact of Asymptomatic Congenital Cytomegalovirus on Adult Quality of Life

OBJECTIVE

Children born with asymptomatic congenital cytomegalovirus infection (AcCMV) have increased risk for hearing loss, which may affect their quality of life into adulthood. We aim to determine quality of life outcomes among adults who were identified at birth with AcCMV compared with controls, using the cohort of the Houston Congenital CMV Longitudinal Study.

METHODS

Quality of life was determined using the self-reported Quality of Life Inventory (QOLI). Sixty-one of 109 AcCMV subjects and 23 of 51 controls completed QOLI. Percentile scores of subjects were compared with percentile scores of controls using Student t tests. QOLI percentile scores were compared among AcCMV subjects with (N = 14) and without hearing loss (N = 47).

RESULTS

There was no difference in mean percentile scores on QOLI between AcCMV subjects (59.8 [SD = 27.6]) and controls (57.3 [SD = 35.3]; p = 0.754). Percentile scores indicate an average overall quality of life classification for AcCMV subjects and controls. There was no difference in mean percentile scores on the QOLI between AcCMV subjects with and without hearing loss (54.8 [SD = 25.2]) and 61.3 [SD = 28.3]; p = 0.440, respectively).

CONCLUSION

Adults born with AcCMV do not seem to have lower ratings of quality of life compared with uninfected controls. Although our study had small sample size, hearing loss does not seem to be a significant predictor of QOLI percentile scores among AcCMV subjects. Quality of life in adulthood does not seem to be affected by an individual's awareness of screening positive for CMV, which supports the notion of "no harm" occurring from universal newborn screening for congenital CMV infection.

Maternal cytomegalovirus immune status and hearing loss outcomes in congenital cytomegalovirus-infected offspring

Objectives

The purpose of this study is to determine the relationship between maternal primary and recurrent CMV infection during pregnancy, symptoms at birth in the newborn, and long term hearing loss through18 years of age.

Patients and methods

237 mother-infant pairs in the Houston, Texas area identified through maternal CMV IgG and IgM antibody serologic screening and newborn screening using urine CMV culture to identify congenital CMV infection were enrolled in the Houston Congenital CMV Longitudinal Study. Mothers were categorized as having primary or recurrent or unknown maternal CMV infections, and newborns were categorized at birth as having symptomatic or asymptomatic congenital CMV infection, or as uninfected controls. All three newborn groups were followed longitudinally with serial hearing evaluations up to 18 years of age. The relationship between type of maternal CMV infection, newborn classification, and the occurrence of hearing loss over time was determined through Kaplan-Meier survival analysis, life table analysis, and a simulated ascertainment of maternal infection type for the unknown categories.

Results

Of 77 newborns with symptomatic congenital CMV infection, 12 (16%) of mothers had a primary CMV infection during pregnancy; 4 (5%) had a non-primary infection, and the type of infection in 48 (79%) could not be determined and were classified as unknown type of maternal infection. Fifty Seven (74%) of the 77 symptomatic children had hearing loss by 18 years of age, including 9 of the 12 (75%) who were born to mothers with primary infection and 48 (79%) of the 61 with unknown type of maternal infection. Of the 109 newborns with asymptomatic congenital CMV infection, 51 (47%) were born to mothers with a primary CMV infection during pregnancy, 18 (17%) to mothers with a recurrent infection; and 40 (37%) had unknown type of infection. Of these 109 asymptomatic cases, 22 (20%) developed hearing loss, including 14 out of 51 (28%) of those born to mothers with primary infection, two out of the 18 (11%) born to mothers with recurrent infection, and 6 out of the 40 (15%) to mothers of unknown infection type. Of the 51 uninfected newborn controls, 10 (20%) of mothers had a primary CMV infection during pregnancy, 5 (10%) had a non-primary infection, 10 (20%) were never infected, and 26 (51%) were assigned unknown type of infection. Three controls (6%) developed hearing loss, with 1 being born to a mother with primary infection and 1 to a mother never infected with CMV.

Conclusions

Both primary and non-primary maternal CMV infections during pregnancy resulted in symptomatic and asymptomatic congenital CMV infection. Symptomatic congenital CMV infection was more likely to occur after primary maternal CMV infection. Sensorineural hearing loss occurred in children born to mothers with both primary and non-primary CMV infections, and in both asymptomatic and symptomatic congenital CMV infection, but was more common after maternal primary infection. Most, but not all, hearing loss in children with cCMV associated hearing loss was first detected within the first year of life.

International multicentre review of perioperative management and outcome for catecholamine-producing tumours

BACKGROUND

Surgery for catecholamine-producing tumours can be complicated by intraoperative and postoperative haemodynamic instability. Several perioperative management strategies have emerged but none has been evaluated in randomized trials. To assess this issue, contemporary perioperative management and outcome data from 21 centres were collected.

METHODS

Twenty-one centres contributed outcome data from patients who had surgery for phaeochromocytoma and paraganglioma between 2000 and 2017. The data included the number of patients with and without α-receptor blockade, surgical and anaesthetic techniques, complications and perioperative mortality.

RESULTS

Across all centres, data were reported on 1860 patients with phaeochromocytoma or paraganglioma, of whom 343 underwent surgery without α-receptor blockade. The majority of operations (78·9 per cent) were performed using minimally invasive techniques, including 16·1 per cent adrenal cortex-sparing procedures. The cardiovascular complication rate was 5·0 per cent overall: 5·9 per cent (90 of 1517) in patients with preoperative α-receptor blockade and 0·9 per cent (3 of 343) among patients without α-receptor blockade. The mortality rate was 0·5 per cent overall (9 of 1860): 0·5 per cent (8 of 517) in pretreated and 0·3 per cent (1 of 343) in non-pretreated patients.

CONCLUSION

There is substantial variability in the perioperative management of catecholamine-producing tumours, yet the overall complication rate is low. Further studies are needed to better define the optimal management approach, and reappraisal of international perioperative guidelines appears desirable.

Specific Programmed Multiple Development–Thin Layer Chromatography of Furazolidone in Chicken, Turkey, Swine, and Bovine Tissues: Collaborative Study

A specific method for assay of furazolidone at 2 ppb has been developed using programmed multiple development-thin layer chromatography (PMD-TLC) and the conversion of the drug to a fluorescent species which is quantitated by fluorodensitometry on the TLC plate. The method requires only 5 g tissue, specifies an automatic spotter for PMD-TLC, and is capable of measuring &lt;1 ng of drug when the fluorodensitometer is coupled with a computing integrator. This procedure requires an average of 2 man-hours per sample and can be completed in one day. Six laboratories collaboratively studied the method for assay of furazolidone at the 2, 3, and 6 ppb levels in chicken, turkey, swine, and bovine tissues. Tissues were fortified by each laboratory and then processed through extraction, solvent partition, programmed multiple development-thin layer chromatography, and fluorodensitometry. Results showed satisfactory recoveries and accuracy. A statistical comparison of the results demonstrated that 5 of the 6 laboratories obtained similar results. The higher responses from the sixth laboratory appeared to be due to an exceptional vacuum system and the use of silated flasks. The mean drug recovery response for the tissues spiked at 2 ppb from the 5 laboratories was 2.2324 ng ± 20.2% (SD), which at the 99.7% confidence level gives no overlap with control tissue data. The results can be expected to be repeatable within and among laboratories.

Intelligence and Academic Achievement With Asymptomatic Congenital Cytomegalovirus Infection

OBJECTIVES

To examine intelligence, language, and academic achievement through 18 years of age among children with congenital cytomegalovirus infection identified through hospital-based newborn screening who were asymptomatic at birth compared with uninfected infants.

METHODS

We used growth curve modeling to analyze trends in IQ (full-scale, verbal, and nonverbal intelligence), receptive and expressive vocabulary, and academic achievement in math and reading. Separate models were fit for each outcome, modeling the change in overall scores with increasing age for patients with normal hearing (n = 78) or with sensorineural hearing loss (SNHL) diagnosed by 2 years of age (n = 11) and controls (n = 40).

RESULTS

Patients with SNHL had full-scale intelligence and receptive vocabulary scores that were 7.0 and 13.1 points lower, respectively, compared with controls, but no significant differences were noted in these scores among patients with normal hearing and controls. No significant differences were noted in scores for verbal and nonverbal intelligence, expressive vocabulary, and academic achievement in math and reading among patients with normal hearing or with SNHL and controls.

CONCLUSIONS

Infants with asymptomatic congenital cytomegalovirus infection identified through newborn screening with normal hearing by age 2 years do not appear to have differences in IQ, vocabulary or academic achievement scores during childhood, or adolescence compared with uninfected children.

Hearing Loss in Children With Asymptomatic Congenital Cytomegalovirus Infection

OBJECTIVES

To assess the prevalence, characteristics, and risk of sensorineural hearing loss (SNHL) in children with congenital cytomegalovirus infection identified through hospital-based newborn screening who were asymptomatic at birth compared with uninfected children.

METHODS

We included 92 case-patients and 51 controls assessed by using auditory brainstem response and behavioral audiometry. We used Kaplan-Meier survival analysis to estimate the prevalence of SNHL, defined as ≥25 dB hearing level at any frequency and Cox proportional hazards regression analyses to compare SNHL risk between groups.

RESULTS

At age 18 years, SNHL prevalence was 25% (95% confidence interval [CI]: 17%-36%) among case-patients and 8% (95% CI: 3%-22%) in controls (hazard ratio [HR]: 4.0; 95% CI: 1.2-14.5; P = .02). Among children without SNHL by age 5 years, the risk of delayed-onset SNHL was not significantly greater for case-patients than for controls (HR: 1.6; 95% CI: 0.4-6.1; P = .5). Among case-patients, the risk of delayed-onset SNHL was significantly greater among those with unilateral congenital/early-onset hearing loss than those without (HR: 6.9; 95% CI: 2.5-19.1; P < .01). The prevalence of severe to profound bilateral SNHL among case-patients was 2% (95% CI: 1%-9%).

CONCLUSIONS

Delayed-onset and progression of SNHL among children with asymptomatic congenital cytomegalovirus infection continued to occur throughout adolescence. However, the risk of developing SNHL after age 5 years among case-patients was not different than in uninfected children. Overall, 2% of case-patients developed SNHL that was severe enough for them to be candidates for cochlear implantation.

Moisture, anisotropy, stress state, and strain rate effects on bighorn sheep horn keratin mechanical properties

This paper investigates the effects of moisture, anisotropy, stress state, and strain rate on the mechanical properties of the bighorn sheep (Ovis Canadensis) horn keratin. The horns consist of fibrous keratin tubules extending along the length of the horn and are contained within an amorphous keratin matrix. Samples were tested in the rehydrated (35wt% water) and ambient dry (10wt% water) conditions along the longitudinal and radial directions under tension and compression. Increased moisture content was found to increase ductility and decrease strength, as well as alter the stress state dependent nature of the material. The horn keratin demonstrates a significant strain rate dependence in both tension and compression, and also showed increased energy absorption in the hydrated condition at high strain rates when compared to quasi-static data, with increases of 114% in tension and 192% in compression. Compressive failure occurred by lamellar buckling in the longitudinal orientation followed by shear delamination. Tensile failure in the longitudinal orientation occurred by lamellar delamination combined with tubule pullout and fracture. The structure-property relationships quantified here for bighorn sheep horn keratin can be used to help validate finite element simulations of ram's impacting each other as well as being useful for other analysis regarding horn keratin on other animals.

STATEMENT OF SIGNIFICANCE

The horn of the bighorn sheep is an anisotropic composite composed of keratin that is highly sensitive to moisture content. Keratin is also found in many other animals in the form of hooves, claws, beaks, and feathers. Only one previous study contains high rate experimental data, which was performed in the dry condition and only in compression. Considering the bighorn sheep horns' protective role in high speed impacts along with the moisture and strain rate sensitivity, more high strain rate data is needed to fully characterize and model the material. This study provides high strain rate results demonstrating the effects of moisture, anisotropy, and stress state. As a result, the comprehensive data allows modeling efforts to be greatly improved.

Efficacy of amitraz-impregnated collars on white-tailed deer (Artiodactyla: Cervidae) in reducing free-living populations of lone star ticks (Acari: Ixodidae)

Over a 7 yr period, we monitored the effect of a commercially available, amitraz impregnated anti-tick collar in controlling free-living populations of lone star ticks, Amblyomma americanum (L.) when manually fitted around necks of white-tailed deer, Odocoileus virginianus (Zimmermann). Study animals in treatment and control groups were confined in 38.8 ha game-fenced and densely vegetated treatment plots in South Texas. Tick densities during years 1 and 7 served as untreated pre- and posttreatment comparisons and treatments occurred during years 2 through 5. Reductions in tick densities in the treatment plot were compared against tick densities in a control plot having similar vegetation and numbers of untreated deer. During years of treatment, indices of control pressure ranged from 18.2 to 82.6 for nymphs and 16.9-78.7 for adults, and efficacy, expressed as percentage control during the final year of treatment, was 77.2 and 85.0%, respectively, for nymphal and adult ticks. These data show that acaricidal collar treatments provide efficacies very similar to those achieved with the existing ivermectin-medicated bait and '4-Poster' topical treatment technologies to control ticks feeding on wild white-tailed deer.

Efficacy of AR-R15896AR in the rat monofilament model of transient middle cerebral artery occlusion

The monofilament technique of transient middle cerebral artery occlusion (MCAO) was used in 3 separate studies to evaluate the efficacy of the low-affinity, use-dependent N-methyl-d-aspartate receptor antagonist, AR-R15896AR. First, a dose-response curve was attempted. Wister Kyoto rats received 2 hours of MCAO. Five minutes later, a 30-minute intravenous infusion of AR-R15896AR was given, followed by subcutaneous implantation of Alzet minipumps that were calibrated to maintain specified plasma levels (approximately 682, 1885, or 2682 ng/mL) of AR-R15896 (free base) for 1 week. The highest plasma level attained significantly decreased the percentage of damage to the subcortex, cortex, and total brain. Second, the high-dose, 1-week treatment regimen was repeated to determine if neuroprotection would extend to 8 weeks after MCAO. Indeed, in separate groups of animals, significant reduction in the percentage of damage, which was generally confined to the cortex and subcortex, was observed at 1, 2, 4, and 8 weeks. Third, verification was achieved in another laboratory. Lister Hooded rats received 60 minutes of transient MCAO. At 70 minutes, an acute dose of AR-R15896AR (20.3 mg/kg) was injected intraperitoneally and the rats were killed 23 hours later. This treatment group also exhibited significant reduction in the volume of infarction in the subcortex, cortex, and total brain. The outcome of these investigations supports the ongoing Phase II clinical trials in patients with acute stroke.

Multimodal hyperspectral imaging for the noninvasive diagnosis of cervical neoplasia

OBJECTIVE

To determine the ability of Multimodal Hyperspectral Imaging (MHI) to noninvasively detect, localize and diagnose cervical neoplasia.

MATERIALS AND METHODS

The cervical epithelium was interrogated by MHI using tissue fluorescence and reflectance measurements after the probe was placed on the ectocervix. A Papanicolaou smear was taken, and a colposcopic examination was performed and cervical histologic specimens were collected, when indicated. MHI and Pap smear sensitivity and specificity data were compared with colposcopic and histologic results.

RESULTS

Nineteen patients had CIN2 or higher, 30 had CIN1, 34 had benign cellular changes or metaplasia, and 28 were normal by both Pap smear and colposcopic examination. At equal specificity (70%) for both tests, the sensitivity of MHI was 97%, compared to 72% for the Pap smear.

CONCLUSION

MHI detected cervical cancer precursors at a rate greater than that obtained by a simultaneously collected Pap smear.

P3-11-03: A Phase I Trial of D-Limonene in Newly Diagnosed Breast Cancer Patients: A Chemoprevention Study

Background: D-limonene (DL) is a highly lipophilic monoterpene found naturally in citrus that has been demonstrated in preclinical studies to have anticancer properties. Early phase clinical trials support the investigation of DL in the chemoprevention of breast cancer. We sought to evaluate whether DL and its presumed active metabolite perillic acid (PA) would distribute extensively to the breast tissue and reach an effective drug concentration. We hypothesized that the mechanism of DL is related to the induction of apoptosis in cancer cells.

Materials and Methods: We enrolled 40 patients with newly diagnosed Stage 0–2 breast cancer to take 2 grams daily of oral DL for 2–6 weeks prior to planned surgical intervention. Blood was drawn pre/post intervention to assess for toxicity and plasma concentration of DL and PA. Adverse effects related or possibly related to the study drug were noted. A small piece of breast tissue adjacent to the tumor mass was used to measure drug concentration for each patient. DL and PA levels in breast tissue were analyzed by gas chromatography and liquid chromatography, respectively, in tandem with mass spectrometry. Analysis of variance testing was used to determine if DL or PA preferentially concentrated in the breast tissue compared to plasma. We tested for a possible modulation of the biomarkers estrogen receptor (ER), progesterone receptor, HER2, Ki67 or grade pre/post treatment by comparing results from the core biopsy to the surgical pathology and applying pairwise Student's T tests. The caspase 3 and the annexin V assays were performed by plating 10,000 cells per well for the cell lines MCF7, MDA-231, BT474, and T47D and separately administering DL and PA acid in serial dilutions in their treatment concentration ranges in triplicate and read by microplate. Results: DL was found to preferentially concentrate in breast tissue versus plasma (tissue/plasma concentration ratio (TPCR) of 1297, p&lt;0.001) while PA did not concentrate (TPCR of 1.4, p=0.9). 20 patients (50%) reported Grade 1 eructation, which was the most common adverse effect. A slight decrease in white count from a mean of 7.1 to 6.6 (p=0.03) and a slight increase in ALT from a mean of 22.5 to 26.9 (p=0.03) were noted. No other statistically significant changes in laboratory values related to serum complete blood count, renal, hepatic or other studies were noted. No change in tissue biomarkers were noted post-treatment. DL produced a dose dependent increase in the apoptotic markers cleaved caspase 3 and annexin V for the ER positive cell lines MCF7, BT474, and T47D, however, no such response was noted for the triple negative cell line MDA-231. A PA dose response trend was noted with the annexin V but not the caspase 3 assay for each cell line.

Discussion: D-limonene preferentially concentrates in the breast tissue and is a candidate chemopreventive agent based on its favorable side effect profile. PA does not readily concentrate in the breast when administered as oral DL. Our correlative studies establish that DL induces apoptosis in ER positive breast cancer cell lines; no definite relationship between PA and apoptosis was found. Further clinical trials of DL are necessary to establish its potential role as a chemopreventive agent in breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-11-03.

THE EFFECTS OF EXPOSURE TO COLD UPON EXPERIMENTAL INFECTION OF THE RESPIRATORY TRACT

1. Respiratory infection of rabbits with Bacillus bovisepticus (snuffles) is favored by chilling the animals after they have been accustomed to heat. 2. The character of this disease, which occurs frequently in rabbits under natural conditions, makes the application of the experimental results to similar respiratory conditions in man less open to objection than in similar experiments with other infections. 3. The weight of experimental evidence, including our own, does not justify the elimination of exposure to cold as a possible though secondary factor in the incidence of acute respiratory disease. 4. From the limited data of our last two experiments it is suggested that any marked change of temperature predisposes rabbits to this infection, the severity of which varies with the amount of change, and that a change from low to high temperature has an even more marked effect than that from high to low.

The effects of temperature and water concentration on the otolith incorporation of barium and manganese in black rockfish Sebastes melanops

Observations of multiple years of geographic variation in [Ba:Ca](otolith) and [Mn:Ca](otolith) in black rockfish Sebastes melanops prompted this study to examine the effects of temperature and water concentration on the otolith incorporation of Ba and Mn in this wholly marine species. The replicated experiment design consisted of two water temperatures (7.4 and 13.0 degrees C) and four water concentrations of Ba:Ca and Mn:Ca. A positive, linear relationship between [Ba:Ca](water) and [Ba:Ca](otolith) was observed at both temperatures. A positive temperature effect was also observed with mean partition coefficients for Ba (D(Ba)) greater in the 13 degrees C than in the 7.4 degrees C treatments (mean = 0.061 and 0.048, respectively). There was no relationship between [Mn:Ca](water) and [Mn:Ca](otolith) although a negative temperature effect was observed. Mean partition coefficients for Mn (D(Mn)) were lower in the 13 degrees C than in the 7.4 degrees C treatments (mean = 0.027 and 0.036, respectively). The data presented support the assumption of a positive, linear relationship between water and otolith Metal:Ca concentrations for Ba:Ca but not for Mn:Ca. Thus, although indicative of residence in distinct water masses, observed variation in [Metal:Ca](otolith) may not reflect variation in water concentration and can be affected by temperature. Caution should be applied in the interpretation of geographic variation of [Mn:Ca](otolith) until the mechanisms regulating its incorporation are more fully understood.

Efficacy of eprinomectin and doramectin against Amblyomma americanum (Acari: Ixodidae) on cattle

Steers were treated with doramectin or eprinomectin by daily oral capsule for 28 consecutive days. The level of doramectin in the serum of steers treated at 200 microg/kg/d reached a maximum of 104.0 +/- 22.1 ppb at day 21 and declined from 93.3 +/- 20.5 ppb on the final day of treatment to below detectable by day 56. Steers treated at 50 microg/kg/d reached a maximum level of doramectin in the serum of 24.7 +/- 1.2 ppb on day 21 and declined from 24.7 +/- 0.6 ppb on the final day of treatment to less than detectable on day 42. Both doramectin dosages provided 100% control of estimated larvae (EL) of Amblyomma americanum (L.) (Acari: Ixodidae) throughout the 28-d treatment period. Daily oral treatment with eprinomectin at a dosage of 200 microg/kg for 28 consecutive days produced a maximum concentration in the serum of 41.6 +/- 11.0 ppb at day 14. On the final day of eprinomectin treatment, the serum concentration was 38.3 +/- 5.9 ppb. Seven days later at day 35, eprinomectin was not detectable in the serum. For steers treated at 50 microg/kg/d for 28 consecutive days, the serum level of eprinomectin reached a maximum of 10.0 +/- 3.0 ppb on day 28 and was undetectable on day 35. Both eprinomectin dosages provided complete control of EL of A. americanum during the 28-d treatment period. Because eprinomectin is efficacious against A. americanum at lower serum levels in cattle and is eliminated from the serum at a more rapid rate than either doramectin or ivermectin, it provides advantages for use in applications such as the medicated bait for control of ticks on white-tailed deer and could have potential for use in the Cattle Fever Tick Eradication Program.

A sustained release gel formulation of doramectin for control of lone star ticks (Acari: Ixodidae) and horn flies (Diptera: Muscidae) on cattle

A gel formulation formed by incorporating technical doramectin into a 10% hydroxypropyl methylcellulose aqueous solution was used to subcutaneously inject steers at varying dosages. Doramectin serum concentration of steers receiving 600 microg (AI)/kg body weight declined from 21.9 ppb at 0.5 wk to below detectable at 8 wk postinjection. The 1,200 microg (AI)/kg injection resulted in serum concentrations of 29.1 ppb at 0.5 wk and declined to 0.5 ppb at 8 wk postinjection. Both the 600 and 1,200 microg (AI)/kg injections provided 100% inhibition of index of fecundity (IF) in adult lone star ticks, Amblyomma americanum L. (Acari: Ixodidae) through week 8, after which inhibition declined to 79.4 and 45.3%, respectively, during the 12th week posttreatment. For steers treated at 600 microg (AI)/kg, mortality of adult horn flies, Hematobia irritans L. (Diptera: Muscidae), declined from 16.9% during week 2 to 3.1% during week 7 postinjection. The blood from steers treated at 1,200 microg (AI)/kg resulted in a similar decline in mortality of blood fed adult horn flies from 29.4% during week 1 to 4.0% during week 7. The 600 microg (AI)/kg treatment provided complete control of larval horn flies in the manure for 9 wk, whereas the 1,200 microg (AI)/kg injection gave complete control for 14 wk posttreatment. The doramectin gel formulation provided long-lasting delivery of doramectin to cattle and extended control of lone star ticks and larval horn flies. Such a simple and inexpensive formulation could be useful in tick eradication programs by reducing the frequency of gathering cattle.

Reduced interference by gray squirrels with 4-poster deer treatment bait stations by using timed-release bait

When white-tailed deer, Odocoileus virginianus, feed on corn bait dispensed by 4-poster tick control devices, they rub against paint rollers impregnated with acaricide. Gray squirrels, Sciurus carolinensis, also feed on the corn bait in the feeding troughs of 4-posters, but in doing so, leave abundant corn fragments and meal that impede the flow of uneaten corn into the troughs. Large accumulations of fragments and meal adversely affect the operation of 4-posters and their use by deer. A battery-operated closure mechanism controlled by a photo sensor was developed to block the flow of corn into the troughs during the day when squirrels are active and deer infrequently visit 4-posters. The effectiveness of the diurnal corn restriction (DCR) concept and restriction mechanism was tested in a field trial at a tick-infested site in Maryland. DCR effectively eliminated accumulation of whole corn, partially eaten corn and corn meal in corn troughs associated with squirrel feeding. At the same time, deer usage of 4-posters was not diminished.

Assessing bioterrorism preparedness and response of rural veterinarians: experiences and training needs

Veterinarians play a unique role in emergency preparedness and response, and federal agencies and academic institutions therefore allocate considerable resources to provide training to enhance their readiness. However, the level of preparedness of veterinarians in many rural regions is yet to be improved. This article reports an assessment of the bioterrorism preparedness, specifically the experience and training needs, of rural veterinarians in North Texas. The study employed a cross-sectional design with a study population that included all veterinarians (N = 352) in the 37 counties within Texas Department of State Health Services Regions 2 and 3. Data on veterinarians practicing or residing in the target region were obtained from the Texas State Board of Veterinary Medical Examiners. The response rate was 35% (n = 121). Results indicate that chemical exposure was the condition most frequently seen and treated, followed by botulism and anthrax. The majority (80%) of respondents indicated that they had not previously participated in training related to bioterrorism preparedness, and many (41%) also indicated a willingness to participate in a state health department-initiated bioterrorism response plan. However, only 18% were confident in their ability to diagnose and treat bioterrorism cases. These results suggest that many North Texas veterinarians practicing in rural regions could benefit from additional training in bioterrorism preparedness and response. An area in particular need of further training is the diagnosis and treatment of Category A agents. Federal, state, and local health agencies are urged to increase training opportunities and to make additional efforts to involve veterinarians in bioterrorism preparedness and response.

The effect of oral contraceptives on the nitric oxide system and renal function

We have demonstrated that oral contraceptive (OC) users exhibit elevated angiotensin II levels and angiotensin II type 1 receptor expression, indicative of renin-angiotensin system (RAS) activation, yet the renal and systemic consequences are minimal, suggesting that there is increased vasodilatory activity, counteracting the effect of RAS activation. We hypothesized that the nitric oxide (NO) system would be upregulated in OC users and that this would be reflected by a blunted hemodynamic response to l-arginine infusion. All subjects were studied after a 7-day controlled sodium and protein diet. Inulin and para-aminohippurate clearance techniques were used to assess renal function. l-Arginine was infused at 100, 250, and 500 mg/kg, each over 30 min. Skin endothelial NO synthase mRNA expression was assessed by real-time PCR. While OC nonusers exhibited significant increases in effective renal plasma flow (670.8 +/- 35.6 to 816.2 +/- 59.7 ml.min(-1).1.73 m(-2)) and glomerular filtration rate (133.4 +/- 4.3 to 151.0 +/- 5.7 ml.min(-1).1.73 m(-2), P = 0.04) and declines in renal vascular resistance (81.1 +/- 6.1 to 63.5 +/- 6.2 mmHg.ml(-1).min, P = 0.001) at the lower l-arginine infusion rates, the responses in OC users were blunted. While l-arginine reduced mean arterial pressure at the 250 and 500 mg/kg doses in OC nonusers, OC users only exhibited a decrease in mean arterial pressure at the highest infusion rate. In contrast, tissue endothelial NO synthase mRNA levels were higher in the OC users (P = 0.04). In summary, these findings suggest that the NO system is upregulated by OC use in young, healthy women. Increased activity of the NO pathway may modulate the hemodynamic effects of RAS activation in OC users.

A spatial-temporal approach to surveillance of prostate cancer disparities in population subgroups

BACKGROUND

Prostate cancer mortality disparities exist among racial/ethnic groups in the United States, yet few studies have explored the spatiotemporal trend of the disease burden. To better understand mortality disparities by geographic regions over time, the present study analyzed the geographic variations of prostate cancer mortality by three Texas racial/ethnic groups over a 22-year period.

METHODS

The Spatial Scan Statistic developed by Kulldorff et al was used. Excess mortality was detected using scan windows of 50% and 90% of the study period and a spatial cluster size of 50% of the population at risk. Time trend was analyzed to examine the potential temporal effects of clustering. Spatial queries were used to identify regions with multiple racial/ethnic groups having excess mortality.

RESULTS

The most likely area of excess mortality for blacks occurred in Dallas-Metroplex and upper east Texas areas between 1990 and 1999; for Hispanics, in central Texas between 1992 and 1996: and for non-Hispanic whites, in the upper south and west to central Texas areas between 1990 and 1996. Excess mortality persisted among all racial/ethnic groups in the identified counties. The second scan revealed that three counties in west Texas presented an excess mortality for Hispanics from 1980-2001. Many counties bore an excess mortality burden for multiple groups. There is no time trend decline in prostate cancer mortality for blacks and non-Hispanic whites in Texas.

CONCLUSION

Disparities in prostate cancer mortality among racial/ethnic groups existed in Texas. Central Texas counties with excess mortality in multiple subgroups warrant further investigation.

Pathogenicity of three formulations of entomopathogenic fungi for control of adult Haematobia irritans (Diptera: Muscidae)

Powder formulations of three species of entomopathogenic fungi were evaluated for their pathogenic effect upon adult horn flies, Hematobia irritans (L.) (Diptera: Muscidae). Flies were treated with conidia and blastospores of the entomopathogenic fungi Beauveria bassiana (Bals.) Vuill. (strain GHA), Metarhizium anisopliae (Metschnikoff) Sorokin (strain ESCI), and Paecilomyces fimosoroseus (Wize) Brown & Smith (strain ARSEF 3581) in the laboratory. At 4 d postexposure, flies treated with B. bassiana had an average of 98.4% mortality versus 43.5% from treatment with M. anisopliae and 13.0% from treatment with P. fiimosoroseus. At 7 d postexposure, flies treated with B. bassiana had an average of 100.0% mortality compared with 73.0% from treatment with M. anisopliae and 33.3% from treatment with P.fumosoroseus. Mean lethal time (LT50) was 2.70, 4.98, and 7.97 d for B. bassiana, M. anisopliae, and P. fiumosoroseus, respectively. Entomopathogenic fungi such as B. bassiana and M. anisopliae may have the potential for controlling populations of horn flies. These studies indicate that B. bassiana and M. anisopliae were not only pathogenic to adult horn flies, but they caused mortality in a short time.

Surveillance of the colorectal cancer disparities among demographic subgroups: a spatial analysis

OBJECTIVE

The literature suggests that colorectal cancer mortality in Texas is distributed inhomogeneously among specific demographic subgroups and in certain geographic regions over an extended period. To understand the extent of the demographic and geographic disparities, the present study examined colorectal cancer mortality in 15 demographic groups in Texas counties between 1990 and 2001.

METHODS

The Spatial Scan Statistic was used to assess the standardized mortality ratio, duration and age-adjusted rates of excess mortality, and their respective p-values for testing the null hypothesis of homogeneity of geographic and temporal distribution.

RESULTS

The study confirmed the excess mortality in some Texas counties found in the literature, identified 13 additional excess mortality regions, and found 4 health regions with persistent excess mortality involving several population subgroups.

CONCLUSION

Health disparities of colorectal cancer mortality continue to exist in Texas demographic subpopulations. Health education and intervention programs should be directed to the at-risk subpopulations in the identified regions.

A high frequency resonance in the responses of retinal ganglion cells to rapidly modulated stimuli: a computer model

Brisk Y-type ganglion cells in the cat retina exhibit a high frequency resonance (HFR) in their responses to large, rapidly modulated stimuli. We used a computer model to test whether negative feedback mediated by axon-bearing amacrine cells onto ganglion cells could account for the experimentally observed properties of HFRs. Temporal modulation transfer functions (tMTFs) recorded from model ganglion cells exhibited HFR peaks whose amplitude, width, and locations were qualitatively consistent with experimental data. Moreover, the wide spatial distribution of axon-mediated feedback accounted for the observed increase in HFR amplitude with stimulus size. Model phase plots were qualitatively similar to those recorded from Y ganglion cells, including an anomalous phase advance that in our model coincided with the amplification of low-order harmonics that overlapped the HFR peak. When axon-mediated feedback in the model was directed primarily to bipolar cells, whose synaptic output was graded, or else when the model was replaced with a simple cascade of linear filters, it was possible to produce large HFR peaks but the region of anomalous phase advance was always eliminated, suggesting the critical involvement of strongly non-linear feedback loops. To investigate whether HFRs might contribute to visual processing, we simulated high frequency ocular tremor by rapidly modulating a naturalistic image. Visual signals riding on top of the imposed jitter conveyed an enhanced representation of large objects. We conclude that by amplifying responses to ocular tremor, HFRs may selectively enhance the processing of large image features.

Epithelioid haemangioma in association with a deep arteriovenous malformation

Epithelioid haemangiomas are benign, vascular tumours characterized by the proliferation of epithelioid endothelial cells with abundant eosinophilic hyaline cytoplasm. We report a case of epithelioid haemangioma in association with a deep arteriovenous malformation of the subclavian artery. The association of reactive vascular proliferations with arteriovenous malformations is uncommonly reported.

Radon track imaging in CR-39 plastic detectors using confocal scanning laser microscopy

Confocal scanning laser microscopy (CSLM) has been used to provide the first images of radon track populations in two external CR-39 plastic detectors. Measurements of variables including track area distribution and estimates of the angle of track inclination (dip) derived from surface CSLM sections are presented. CSLM depth slices, combined with three-dimensional (3D) visualization techniques, provide a new, non-destructive way of examining the 2D and 3D geometry of the etched tracks within solid-state nuclear track detectors that may prove useful in complementing existing optical microscopy methods.

Distribution of horn flies on individual cows as a percentage of the total horn fly population

Twenty-three mixed-breed herd cows were phenotyped for their ability to serve as a suitable host for Haematobia irritans, the horn fly. Based upon consistent observations within the lower quartile or upper quartile of individual fly counts, four cows were phenotyped as low carriers and five cows were phenotyped as high carriers of horn flies. The cows designated as low carriers consistently carried levels of flies below the economic threshold. However, during a period of fly population explosion, low carriers harbored flies well above the economic threshold. Although the number of flies counted on these low carrying cattle increased as the population increased, the relative percentage of the population that they carried changed very little. A hypothesis is proposed to explain this observation, and future studies are suggested.

Control of Ixodes scapularis (Acari: Ixodidae) with topical self-application of permethrin by white-tailed deer inhabiting NASA, Beltsville, Maryland

We report the first successful area-wide reduction of Ixodes scapularis by using minimal amounts of permethrin self-applied by free-ranging white-tailed deer in as little as 3 y of nearly continuous treatment. The study to control all active stages of L. scapularis Say was initiated in April 1995, at the Goddard Space Flight Center, National Aeronautics and Space Administration (NASA), Beltsville, Maryland (treated location), and the Patuxent Wildlife Research Center, Laurel, Maryland (non-treated location). The locations had similar flora and fauna, and pre-treatment sampling (April to October 1995) of deer, plots, and mice for I. scapularis indicated nearly similar tick populations at both locations. After pre-treatment sampling, 4 deer '4-poster' stations were placed at NASA, while the control area received none. Ten percent permethrin, supplied to 4 roller covers on each station, was passively transferred to the head, neck, and ears of free-ranging deer feeding at the stations. This treatment resulted in elimination of adult I. scapularis on sampled deer (100% control) by the 2nd y of treatment and reductions of immature tick stages on mice. During the 3rd y of treatment, adult, nymphal, and larval questing ticks were reduced by 91-100% from sampled plots, and nymphal and larval ticks were reduced by 70-95% on sampled mice.

Pharmacokinetics of ivermectin in llamas (Lama glama)

The pharmacokinetic behaviour of ivermectin was investigated in adult llamas (Lama glama) by using high performance liquid chromatography with a lower limit of quantification of 2 ng/ml to measure its concentration in serum. Llamas were treated with one of three commercial formulations (injectable, pour-on or oral paste) at dosages recommended by the manufacturer, or with an experimental injectable sustained-release formulation. In five llamas given 1 per cent ivermectin subcutaneously at 200 microg/kg, the median peak serum concentration (Cmax) was 3 ng/ml and the area under the serum concentration-time curve (AUC) was 13.5 ng x day/ml. In six llamas treated topically with 0.5 per cent ivermedin pour-on at 500 microg/kg, Cmax was 2.5 ng/ml or less and the AUC was 7.75 ng x day/ml or less. In seven llamas with measurable concentrations of ivermedin, the median times to peak serum concentration (tmax) were six days after subcutaneous injection and seven days after treatment with the pour-on formulation. In six llamas, the serum concentration of ivermectin remained less than 2 ng/ml for 124 hours after treatment with a 1.87 per cent oral paste at 200 microg/kg. In five llamas treated subcutaneously with 25 per cent ivermectin sustained-release microspheres at 1500 microg/kg, the median Cmax was 5 ng/ml and the median AUC was 224 ng x day/ml.

Infrared frequency-modulation probing of product formation in alkyl + O2 reactions. Part IV. Reactions of propyl and butyl radicals with O2

The time-resolved production of HO2 in the Cl-initiated oxidation of iso- and n-butane is measured using continuous-wave (CW) infrared frequency modulation spectroscopy between 298 and 693 K. The yield of HO2 is determined relative to the Cl2/CH3OH/O2 system. As in studies of smaller alkanes, the branching fraction to HO2 + alkene in butyl + O2 displays a dramatic rise with increasing temperature between about 550 and 700 K (the "transition region") which is accompanied by a qualitative change in the time behavior of the HO2 production. At low temperatures the HO2 is formed promptly; a second, slower production of HO2 is responsible for the bulk of the increased yield in the transition temperature region. In contrast to reactions of smaller alkyl radicals with O2, the total HO2 yield in the butyl radical reactions appears to remain significantly below 1 up to 700 K, implying a significant role for OH-producing channels. The slower HO2 production in butane oxidation displays an apparent activation energy similar to that measured for smaller alkyl + O2 reactions, suggesting that the energetics of the HO2 elimination transition state are similar for a broad range of R + O2 systems. A combination of QCISD(T) based characterizations of the propyl and butyl + O2 potential energy surfaces and master equation based characterization of the propyl + O2 kinetics provide the framework for explanation of the experimentally observed HO2 production in Cl-initiated propane and butane oxidation. These calculations suggest that the HO2 elimination channel is similar in all reaction systems, and that hydroperoxyalkyl (QOOH) species produced by internal H-atom abstraction in RO2 can provide a path to OH formation. However, the QOOH formed by the energetically favorable 1,5 isomerization (via a six-membered ring transition state) generally experiences significant barriers (relative to the radical + O2 reactants) to the production of an oxetane + OH. In contrast, the barriers to forming OH + an oxirane or an oxolane, via 1,4 or 1,6 isomerizations, respectively, are generally below reactants.

A theoretical analysis of the reaction between propargyl and molecular oxygen

The temperature- and pressure-dependent kinetics of the reaction between propargyl and molecular oxygen have been studied with a combination of electronic structure theory, transition state theory, and the time-dependent master equation. The stationary points on the potential energy surface were located with B3LYP density functional theory. Approximate QCISD(T,Full)/6-311++G(3df,2pd) energies were obtained at these stationary points. At low temperatures the reaction is dominated by addition to the CH2 side of the propargyl radical followed by stabilization. However, addition to the CH side, which is followed by one of various possible internal rearrangements, becomes the dominant process at higher temperatures. These internal rearrangements involve a splitting of the O2 bond via the formation of 3-, 4- or 5-membered rings, with the apparent products being CH2CO + HCO. Rearrangement via the 3-membered ring is found to dominate the kinetics. Rearrangement from the CH2 addition product, via a 4-membered ring, would yield H2CO + HCCO, but the barrier to this rearrangement is too high to be kinetically significant. Other possible products require H transfers and, as a result, appear to be kinetically irrelevant. Modest variations in the energetics of a few key stationary points (most notably the entrance barrier heights) yield kinetic results that are in good agreement with the experimental results of Slagle and Gutman (I. R. Slagle and D. Gutman, Proc. Combust. Inst., 1986, 21, 875) and of Atkinson and Hudgens (D. B. Atkinson and J. W. Hudgens, J. Phys. Chem. A, 1999, 103, 4242).

A direct transition state theory based analysis of the branching in NH2 + NO

A combination of high-level quantum-chemical simulations and sophisticated transition state theory analyses is employed in a study of the temperature dependence of the N2H + OH-->HNNOH recombination reaction. The implications for the branching between N2H + OH and N2 + H2O in the NH2 + NO reaction are also explored. The transition state partition function for the N2H + OH recombination reaction is evaluated with a direct implementation of variable reaction coordinate (VRC) transition state theory (TST). The orientation dependent interaction energies are directly determined at the CAS + 1 + 2/cc-pvdz level. Corrections for basis set limitations are obtained via calculations along the cis and trans minimum energy paths employing an approximately aug-pvtz basis set. The calculated rate constant for the N2H + OH-->HNNOH recombination is found to decrease significantly with increasing temperature, in agreement with the predictions of our earlier theoretical study. Conventional transition state theory analyses, employing new coupled cluster estimates for the vibrational frequencies and energies at the saddlepoints along the NH2 + NO reaction pathway, are coupled with the VRC-TST analyses for the N2H + OH channels to provide estimates for the branching in the NH2 + NO reaction. Modest variations in the exothermicity of the reaction (1-2 kcal mol-1), and in a few of the saddlepoint energies (2-4 kcal mol-1), yield TST based predictions for the branching fraction that are in satisfactory agreement with related experimental results. The unmodified results are in reasonable agreement for higher temperatures, but predict too low a branching ratio near room temperature, as well as too steep an initial rise.

Losartan may modulate erythropoietin production

Erythropoietin (Epo) is distinct amongst haematopoietic hormones, in that it is produced remote from the bone marrow. The tissue oxygen pressure required to trigger the Epo gene under physiological conditions is uniquely sited at a restricted area in the kidney termed the critmeter. Angiotensin II (Ang II) increases sodium reabsorption and hence oxygen consumption at any given bloodflow rate; therefore, it may affect the balance of renal oxygen supply vs. demand and hence Epo production. The purpose of this study was to determine whether Epo production is modulated by the renin-angiotensin system (RAS). Twenty normal subjects on a controlled sodium and protein diet had glomerular filtration rate (GFR) and renal plasma flow (RPF)assessed by standard methods of inulin and para-aminohippurate clearance, respectively, at baseline, hourly after the administration of losartan (25 mg) and after each 30 minute period of the infusion of Ang II at doses of 0.5, 1.5 and 2.5 ng/kg/minute. The baseline GFR was 115+/-4.0 ml/minute/1.73 m2, RPF 650+/-29 ml/minute/1.73 m2 and Epo 12.4+/-0.8 U/L. In spite of a marked increase in filtration fraction (FF) with Ang II, no changes in serum Epo levels were observed at two hours(11.7+/-1.3 U/L, p=n.s. compared with baseline). After the administration of losartan, there was a variable effect on FF, but a strong correlation of the change in serum Epo concentration and the change in FF(r=0.648, p=0.002), suggesting that the RAS may modulate Epo production.

The Ivomec SR Bolus for control of Boophilus annulatus (Acari: Ixodidae) on cattle in South Texas

When Hereford heifers infested with Boophilus annulatus (Say) were treated with a single Ivomec SR Bolus, the concentration of ivermectin in the serum of the treated cattle reached a maximum of 8.8 +/- 0.9 ppb at 2 wk posttreatment. The single bolus treatment resulted in 84.4% control of standard engorging B. annulatus females on treated cattle over the 20-wk trial. Although fewer engorged ticks were collected from the sentinel heifers exposed in the treated pasture than those in the control pasture at weeks 4, 10, and 16 posttreatment, none of the differences was statistically significant. Each exposure of sentinel cattle found free-living ticks in both the treated and control pastures, indicating the infestation was not eliminated by the treatment. When the trial was repeated using two Ivomec SR Boluses/heifer, the concentration of ivermectin in the serum of the treated cattle reached a maximum level of 31.2 +/- 3.9 ppb at week 13 posttreatment. The use of two boluses/heifer resulted in 99.6% control of standard engorging B. annulatus females over the 20-wk trial. No ticks were found on sentinels placed in the treated pasture after week 9 posttreatment, an indication that the treatment had eliminated the free-living population in the treated pasture. From these studies, we conclude that a single Ivomec SR Bolus is incapable of sufficient control of B. annulatus to meet the rigid requirements of the Cattle Fever Tick Eradication Program in South Texas. Although two boluses per animal did eliminate the ticks from treated heifers and the pasture they were in, the treatment would not be sufficiently efficacious for mature cattle (>400 kg) for it to be useful in the program.

Rehabilitation of a patient with severe dentoalveolar injuries: a case report with a 10-year follow-up

This clinical report describes the emotional and physical rehabilitation of a young man. The impact of the injuries sustained and repeated failure of traditional dental treatment methods had caused the patient to become quite withdrawn. A successful outcome followed surgical placement of multiple titanium plasma-sprayed cylindrical fixtures in severely damaged dental supporting tissues to serve as intermediary abutments for complex maxillary and mandibular fixed prostheses. The loss of crestal bone during the postprosthetic years is determined. The advantages only implant dentistry could bring are identified.

Treatment of chronic granulomatous disease with nonmyeloablative conditioning and a T-cell-depleted hematopoietic allograft

BACKGROUND

The treatment of chronic granulomatous disease with conventional allogeneic hematopoietic stem-cell transplantation carries a high risk of serious complications and death. We investigated the feasibility of stem-cell transplantation without ablation of the recipient's bone marrow.

METHODS

Ten patients, five children and five adults, with chronic granulomatous disease underwent peripheral-blood stem-cell transplantation from an HLA-identical sibling. We used a nonmyeloablative conditioning regimen consisting of cyclophosphamide, fludarabine, and antithymocyte globulin. The allograft was depleted of T cells to reduce the risk of severe graft-versus-host disease. Donor lymphocytes were administered at intervals of 30 days or more after the transplantation to facilitate engraftment.

RESULTS

After a median follow-up of 17 months (range, 8 to 26), the proportion of donor neutrophils in the circulation in 8 of the 10 patients was 33 to 100 percent, a level that can be expected to provide normal host defense; in 6 the proportion was 100 percent. In two patients, graft rejection occurred. Acute graft-versus-host disease (grade II, III, or IV) developed in three of the four adult patients with engraftment, one of whom subsequently had chronic graft-versus-host disease. None of the five children had grade II, III, or IV acute graft-versus-host disease. During the follow-up period, four serious infections occurred among the patients who had engraftment. Three of the 10 recipients died. Preexisting granulomatous lesions resolved in the patients in whom transplantation was successful.

CONCLUSIONS

Nonmyeloablative conditioning followed by a T-cell-depleted hematopoietic stem-cell allograft is a feasible option for patients with chronic granulomatous disease, recurrent life-threatening infections, and an HLA-identical family donor.

Effect of oral contraceptives on the renin angiotensin system and renal function

We examined the effect of oral contraceptive (OC) usage on the renin angiotensin system (RAS) in two related experiments. In the first experiment, subjects were 34 healthy, normotensive, premenopausal women, 15 OC users and 19 OC nonusers, mean age 25 +/- 1 yr, ingesting a controlled sodium diet. We assessed arterial pressure, glomerular filtration rate, effective renal plasma flow, renal vascular resistance (RVR), and filtration fraction (FF) using inulin and p-aminohippurate clearance techniques, both at baseline and in response to the ANG II receptor blocker losartan. In the second experiment, in similar subjects, 10 OC users and 10 nonusers, we examined circulating RAS components [angiotensinogen, ANG II, aldosterone, plasma renin activity (PRA), and active renin] in response to incremental lower body negative pressure (LBNP), to determine whether renin secretion is suppressed by OC usage. OC users exhibited elevations in systolic blood pressure, RVR, and FF compared with nonusers, which were partially corrected by losartan. In the LBNP phase of the study, baseline measures of PRA, angiotensinogen, ANG II, and aldosterone were all increased in the OC group compared with the control group. Active renin levels did not differ between groups. Incremental LBNP resulted in increased circulating levels of RAS components in both groups. We conclude that the RAS is activated in women using OCs. There was no evidence that decreases in renin secretion result in normalization of the RAS as a whole.

Sickle cell crisis in the adult: chest radiographic findings and comparison with pediatric sickle cell disease

With the advent of improved therapy, an increasing proportion of individuals suffering from sickle cell disease (SCD) are surviving into adulthood. In contrast to children, little has been documented concerning the typical radiographic findings in adults presenting with sickle cell crises (SCC). We describe the chest radiographic (CXR) manifestations of adults with SCD presenting in SSC, correlated to hemoglobin (Hb) values, and compare them to those of the pediatric sickle cell population. The chest radiographs of 66 consecutive adults presenting to our emergency department complaining of symptoms consistent with acute SCC were retrospectively reviewed over a 12-month period. The radiographic findings were correlated with admission Hb values and compared with those of 50 children with known SCD presenting with SCC. Chi square analysis revealed no significant difference between the cardiovascular and bony findings in the adults and in those of the pediatric controls (p > 0.08-p > 1.0). However, one important difference in the two cohorts was that upper lobe infiltrates occurred exclusively in the pediatric group (p = 0.06). There was a statistically significant (p < 0.05) difference in cardiovascular and skeletal abnormalities between adults with Hb above and below the mean (8.2 g/dL). The radiographic features of adults presenting in acute SCCs are similar to those of children. Although the chest radiograph is often normal, in decreasing frequency, cardiovascular abnormalities, pneumonia sparing the upper lobes, and aseptic osteonecrosis of the shoulders and spine are not uncommon. There is a significant relationship, however, between cardiovascular abnormalities and Hb levels.

Angiotensin II type 1 receptor gene polymorphisms in humans: physiology and pathophysiology of the genotypes

Many studies have attempted to relate genetic variants of components of the renin-angiotensin system to complex diseases such as essential hypertension, cardiovascular disease and progressive renal failure. The angiotensin II type 1 receptor (AT1R) gene is an important example of this approach. Many polymorphisms of the AT1R gene have been identified, but the A1166-->C polymorphism has been the most extensively studied. The physiological significance of this polymorphism is uncertain because of its location in the 3'-untranslated region of the gene. The present review summarizes association studies of the AT1R gene, focusing on clinical end-points and physiological responses.