The low-LET radiation contribution to the tumor dose in diffusing alpha-emitters radiation therapy

BACKGROUND

Diffusing alpha-emitters Radiation Therapy ("Alpha DaRT") is a new technique that enables the use of alpha particles for the treatment of solid tumors. Alpha DaRT employs interstitial sources carrying a few μ $\mu$ Ci of224 $^{224}$ Ra below their surface, designed to release a chain of short-lived atoms (progeny of224 $^{224}$ Ra) which emit alpha particles, along with beta, Auger, and conversion electrons, x- and gamma rays. These atoms diffuse around the source and create-primarily through their alpha decays-a lethal high-dose region measuring a few millimeters in diameter.

PURPOSE

While previous studies focused on the dose from the alpha emissions alone, this work addresses the electron and photon dose contributed by the diffusing atoms and by the atoms remaining on the source surface, for both a single Alpha DaRT source and multi-source lattices. This allows to evaluate the low-LET contribution to the tumor dose and tumor cell survival, and demonstrate the sparing of surrounding healthy tissue.

METHODS

The low-LET dose is calculated using the EGSnrc and FLUKA Monte Carlo (MC) codes. We compare the results of a simple line-source approximation with no diffusion to those of a full simulation, which implements a realistic source geometry and the spread of diffusing atoms. We consider two opposite scenarios: one with low diffusion and high212 $^{212}$ Pb leakage, and the other with high diffusion and low leakage. The low-LET dose in source lattices is calculated by superposition of single-source contributions. Its effect on cell survival is estimated with the linear quadratic model in the limit of low dose rate.

RESULTS

For sources carrying 3  μ $\umu$ Ci/cm224 $^{224}$ Ra arranged in a hexagonal lattice with 4 mm spacing, the minimal low-LET dose between sources is∼ 18 - 30 $\sim 18-30$  Gy for the two test cases and is dominated by the beta contribution. The low-LET dose drops below 5 Gy∼ 3 $\sim 3$  mm away from the outermost source in the lattice with an effective maximal dose rate of< 0.04 $<0.04$  Gy/h. The accuracy of the line-source/no-diffusion approximation is∼ 15 % $\sim 15\%$ for the total low-LET dose over clinically relevant distances (2-4 mm). The low-LET dose reduces tumor cell survival by a factor of∼ 2 - 200 $\sim 2-200$ .

CONCLUSIONS

The low-LET dose in Alpha DaRT can be modeled by conventional MC techniques with appropriate leakage corrections to the source activity. For 3  μ $\umu$ Ci/cm224 $^{224}$ Ra sources, the contribution of the low-LET dose can reduce cell survival inside the tumor by up to two orders of magnitude. The low-LET dose to surrounding healthy tissue is negligible. Increasing source activities by a factor of 5 can bring the low-LET dose itself to therapeutic levels, in addition to the high-LET dose contributed by alpha particles, leading to a "self-boosted" Alpha DaRT configuration, and potentially allowing to increase the lattice spacing.

RADIATION DETECTOR FOR THE ISRAELI FIRST RESPONDERS-METHODOLOGY OF SELECTION

This paper presents the rationale and development of a methodology of selection of a radiation detector that can be used by first responders arriving to a terror event scene, not knowing if the event involves any radioactive materials. This detector can be used to detect and quantify the presence of gamma radiation. The role of this detector in a radiological terror event is reviewed via the operational concept for handling radiological terror in Israel. The development of the methodology of selection included a literature survey of relevant radiation detector categories, followed by a user-side survey of requirements based on the first responders' experience along with the Israeli Ministry of Defense perspective on the management of radiological events, supplemented by the input from experts in aspects of radiation detection, radiation protection and dosimetry from the Israel Atomic Energy Commission's Soreq Nuclear Research Center. The general qualitative characterisation of requirements was then quantified using a scoring method, enabling the methodological evaluation and numerical ranking of available detectors. Plans to evaluate candidate detector models according to the developed methodology are outlined. The detectors evaluation will be conducted as part of the procurement procedure of future detectors for first responders.

Diffusing alpha-emitters radiation therapy in combination with temozolomide or bevacizumab in human glioblastoma multiforme xenografts

Glioblastoma multiforme (GBM) is at present an incurable disease with a 5-year survival rate of 5.5%, despite improvements in treatment modalities such as surgery, radiation therapy, chemotherapy [e.g., temozolomide (TMZ)], and targeted therapy [e.g., the antiangiogenic agent bevacizumab (BEV)]. Diffusing alpha-emitters radiation therapy (DaRT) is a new modality that employs radium-224-loaded seeds that disperse alpha-emitting atoms inside the tumor. This treatment was shown to be effective in mice bearing human-derived GBM tumors. Here, the effect of DaRT in combination with standard-of-care therapies such as TMZ or BEV was investigated. In a viability assay, the combination of alpha radiation with TMZ doubled the cytotoxic effect of each of the treatments alone in U87 cultured cells. A colony formation assay demonstrated that the surviving fraction of U87 cells treated by TMZ in combination with alpha irradiation was lower than was achieved by alpha- or x-ray irradiation as monotherapies, or by x-ray combined with TMZ. The treatment of U87-bearing mice with DaRT and TMZ delayed tumor development more than the monotherapies. Unlike other radiation types, alpha radiation did not increase VEGF secretion from U87 cells in culture. BEV treatment introduced several days after DaRT implantation improved tumor control, compared to BEV or DaRT as monotherapies. The combination was also shown to be superior when starting BEV administration prior to DaRT implantation in large tumors relative to the seed size. BEV induced a decrease in CD31 staining under DaRT treatment, increased the diffusive spread of 224Ra progeny atoms in the tumor tissue, and decreased their clearance from the tumor through the blood. Taken together, the combinations of DaRT with standard-of-care chemotherapy or antiangiogenic therapy are promising approaches, which may improve the treatment of GBM patients.

A METHOD TO IDENTIFY AND LOCALIZE A SINGLE HOT PARTICLE IN THE LUNGS USING AN ARRAY OF HIGH-PURITY GERMANIUM DETECTORS FOR IMPROVED ESTIMATE OF THE DEPOSITED ACTIVITY

A new method has been developed to identify and localize a single hot particle in the lungs using an array of four high-purity germanium detectors. The method is based upon calculating a set of three count rate ratios (generated by each individual detector in the array) that are evaluated in sequence to designate whether the measured deposition can be associated with a hot particle rather than the default assumption of a uniform activity distribution. Identification and localization of the hot particle are determined from a single in vivo measurement in which detectors are positioned above and below the thorax. The method was tested using an anthropomorphic thorax phantom in which point sources of 241Am, 137Cs and 60Co were individually inserted in the lungs at 15 different locations and were measured using a scanning bed whole-body counter. Depending upon source location and photon energy, a bias of -35% up to +76% could be introduced by falsely assuming a uniform activity distribution in the lungs. This bias would directly translate to an erroneous dose estimate to the lungs. It was demonstrated that by using the appropriate detector efficiencies for the single hot particle, the bias associated with the activity determination is reduced to <10% and ~2% in average.

Implementation of a triage monitoring program for internal exposure to short-lived radionuclides in Israel-challenges and recommendations

Monitoring internal exposure to short-lived radionuclides is challenging, due to the frequent measurements required. ISO Standard 16 637 and the Swiss Personal Dosimetry Ordinance describe a screening measurement (triage monitoring) conducted in the workplace to identify workers suspected of internal exposure. Based on a previous study that examined the feasibility of using several commonly found radiation monitors in Israel in a triage monitoring program, we conducted a pilot study towards the implementation of triage monitoring in nuclear medicine facilities in Israel. The pilot study was conducted while considering the current Israeli regulations and local safety culture. We implemented the triage monitoring program in three nuclear medicine facilities in Israel, with a total of 55 monitored workers. The pilot study consisted of two stages: a short-term stage conducted in the largest manufacture of radiopharmaceuticals in Israel and a long-term stage in two nuclear medicine departments in Israel. During the first stage of the study, participants were asked to conduct a daily measurement at the end of the workday and send a urine sample to the national internal dosimetry laboratory. The second stage lasted 5 months in a major hospital and 18 months in a regional hospital. The workers were asked to perform the measurement at the end of the shift and send a urine sample if a defined threshold had been crossed. The mean participation rate in the long-term stage (>70%) indicates that implementation of the triage monitoring program could be successful in Israel. Based on the findings of the study, practical recommendations are listed: suitable monitoring devices, allocating a monitoring location, time of measurement, training of the workers, record keeping and coordination with a certified dosimetry laboratory. The pilot study recommendations were submitted to the Israel Institute for Occupational Safety and Hygiene at the Ministry of Labor, Social Affairs and Social Services.

Abstract P2-04-02: Comparison of DNA methylation patterns in normal breast tissue from women with and without breast cancer

BACKGROUND: Increasing evidence suggests that epigenetic mechanisms play critical roles in the development of breast cancer. However, precise DNA methylation signatures associated with breast cancer susceptibility remain unknown. We sought to compare DNA methylation changes in the normal breast tissue of women with and without breast cancer to identify patterns of aberrant DNA methylation in women with breast cancer.

METHODS:Samples of normal breast tissue were collected from four cohorts of women: age &lt; 50 years with and without breast cancer, and age ≥50 years with and without breast cancer. Normal breast tissue from healthy women was obtained from the Komen Tissue Bank at IU Simon Cancer Center and from women presenting for reduction mammoplasty at Yale New Haven Hospital. Normal breast tissue from women with breast cancer was obtained from patients undergoing adjuvant total mastectomy at Yale Breast Center. DNA was extracted using Qiagen AllPrep Universal kit. Raw data files in idat format were imported to Partek Genomics Suite 6.6 for normalization and differential methylation analysis. Raw intensities were normalized using With Array Normalization (SWAN) method. Principal component analysis (PCA) were performed as quality control. Differentially methylated loci (DML) between control and breast cancer groups were detected when False discovery rate (FDR) &lt; 0.05 and fold change &gt; 1.5. Functional enrichment analysis of genes with DML in the gene body were conducted using METACORE™. Pathways with FDR &lt; 0.05 were selected.

RESULTS: Ninety-three normal breast tissue samples from 89 subjects were analyzed (breast cancer=40, unaffected=53). Comparison of DNA methylation patterns between women with and without breast cancer revealed 200 DMLs. The majority of DMLs (186) were hyper-methylated in breast cancer patients, and 48 DMLs locate in enhancers of genes. 170 DMLs locate in 134 genes, enriched in two pathways: (1) Cell adhesion_Endothelial cell contacts by junctional mechanisms, and (2) Neurophysiological process_Constitutive and regulated NMDA receptor trafficking. Genes associated with cell adhesion and cell contacts included: ACTN2, GJA4, GJA7 and MAGI1. Two hyper-methylated loci were found in enhancers of ACTN2. In addition, one hyper-methylated locus in GJA4, one hyper-methylated and one hypo-methylated loci in GJA7, and two hyper-methylated loci in MAGI1 were detected in breast cancer patients. Genes associated with NMDA receptor trafficking include: TPK1, ADCY4 and LIN7C. One and two loci were found in TPK1 and ADCY4, respectively, that were hyper-methylated in normal breast tissue from cancer patients in the gene body, while a hypo-methylated locus in breast cancer patients was identified in LIN7C.

CONCLUSIONS: Comparison of DNA methylation patterns of normal breast tissue from women with and without breast cancer reveal specific mechanistic pathways and genes that are differentially methylated in women with breast cancer. DNA methylation of normal breast tissue deserves further study as a potential biomarker for breast cancer risk stratification and may lend new insight into mechanisms of breast cancer development.

Citation Format: Hofstatter EW, Zhu Y, Horvath S, Chagpar AB, Wali VB, Bossuyt V, Storniolo AM, Hatzis C, Patwardhan G, Von Wahlde M-K, Butler M, Epstein L, Stavris K, Sturrock T, Au A, Kwei S, Pusztai L. Comparison of DNA methylation patterns in normal breast tissue from women with and without breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-04-02.

AN ESTIMATION OF THE EXPOSURE OF THE POPULATION OF ISRAEL TO NATURAL SOURCES OF IONIZING RADIATION

The radiation dose to the population of Israel due to exposure to natural sources of ionizing radiation was assessed. The main contributor to the dose is radon that accounts for 60% of the exposure to natural sources. The dose due to radon inhalation was assessed by combining the results of a radon survey in single-family houses with the results of a survey in apartments in multi-storey buildings. The average annual dose due to radon inhalation was found to be 1.2 mSv. The dose rate due to exposure to cosmic radiation was assessed using a code that calculates the dose rate at different heights above sea level, taking into account the solar cycle. The annual dose was calculated based on the fraction of time spent indoors and the attenuation provided by buildings and was found to be 0.2 mSv. The annual dose due to external exposure to the terrestrial radionuclides was similarly assessed. The indoor dose rate was calculated using a model that takes into account the concentrations of the natural radionuclides in building materials, the density and the thickness of the walls. The dose rate outdoors was calculated based on the concentrations of the natural radionuclides in different geological units in Israel as measured in an aerial survey and measurements above ground. The annual dose was found to be 0.2 mSv. Doses due to internal exposure other than exposure to radon were also calculated and were found to be 0.4 mSv. The overall annual exposure of the population of Israel to natural sources of ionizing radiation is therefore 2 mSv and ranges between 1.7 and 2.7 mSv.

Abstract PD4-07: Impact of breast density legislation on Hispanic / Latinas in the Northeast, US

Objective: Changes in health care delivery and policies resulting from translational research efforts are intended to benefit a broad segment of the affected population. Yet, uptake of new approaches may not occur at the same level and/or pace in all groups, inadvertently increasing disparities in cancer outcomes. Our objective is to explore the impact of recently enacted legislation associated with routine mammography screening on Hispanic /Latino women living in Connecticut. Background: Breast densities are the non-fat (epithelial and stromal) breast tissue observable on screening mammograms. They are associated with a 4 to 6 fold increase in breast cancer risk and complicate the reading of screening mammograms, resulting in lowered sensitivity. Connecticut (CT) and many other states have enacted legislation requiring supplemental testing to be offered to women with dense breasts. Per CT statute, insurance companies must cover the cost of ultrasound screening of an entire breast/breasts for women with heterogeneously or extremely dense breasts. Additionally, personal information on breast density must be included in the mailed result following a screening mammogram. The intent is to improve early detection in women with dense breasts and to increase awareness of the greater risk of associated with dense breast tissue. Methods: After this law was enacted in 2008, we undertook a large prospective study of mammography screening in community based Hispanic/Latinas. We enrolled women seeking care in primary health care settings in the 4 CT cities with the largest H/L populations. Eligible women were ages 40-75, self-identified as H/L, and had negative history for breast cancer or breast biopsy. With 75% participation for baseline interview and 98% consent for medical record review, we report baseline interview data and mammography results (medical records) over a 2.5 - 4 year follow-up on 668 H/L women, ages 40-79, living in CT at the time of enrollment (2009-2011). Results: The women in this study were mostly foreign or Puerto Rican born (84%), lower socioeconomic status (51% with household incomes less than $10,000 per year; 54% less had than a high school education) than the general population; median age was 51. Nearly half (46.0%) reported no usual care provider. Only 14% reported speaking English "very well". Most women reported that they received a mammogram in the previous year (65.0%). 21.4% of women met the criteria for receiving additional bilateral ultrasound testing due to heterogeneously dense (19.2%) or extremely dense (2.3%) breast tissue on screening mammograms occurring during follow up. Of the 128 women eligible for follow-up ultrasound, 18 (14%) received this exam. Conclusion: Although state law requires patient notification of breast density and insurance coverage for supplementary bilateral ultrasound tests in women with moderate to extremely dense breasts, our results show low uptake in Hispanic/Latino women in CT. In this largely foreign born, English second language population, effective communication regarding breast cancer risk, breast density, and the availability of follow-up ultrasound or other testing may represent a significant cancer care challenge.

Citation Format: Jones BA, Philpotts L, Cooley R, Silber A, Epstein L, Claye E. Impact of breast density legislation on Hispanic / Latinas in the Northeast, US. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD4-07.

Radon concentrations in different types of dwellings in Israel

The average radon concentration in Israeli dwellings was assessed by combining the results of a 2006 radon survey in single-family houses with the results of a 2011 radon survey in apartments of multistorey buildings. Both surveys were based on long-term measurements using CR-39 detectors. The survey in multistorey buildings was intended to assess the influence of recent practices in the local building industry on the radon concentrations. These practices include the use of building materials with higher concentrations of the natural radionuclides in the last 20 y than before, as well as the improvement in sealing techniques over that period. Another practice in place since the early 1990 s is the building of a shielded area in every apartment that is known as an RSS (residential secure space). The RSS is a room built from massive concrete walls, floor and ceiling that can be hermetically sealed and is intended to protect its residents from a missile attack. The influence of the above-mentioned features on radon concentrations was estimated by dividing the participating apartments into two groups: apartments in buildings >20 y, built using building materials with low concentrations of the natural radionuclides, regular sealing and without an RSS and apartments in buildings newer than 10 y, built using building materials with higher concentrations of the natural radionuclides, improved sealing and including an RSS. It was found that the average radon concentration in apartments in new buildings was significantly higher than in old buildings and the average radon concentration in single-family houses was significantly higher than in apartments in multistorey buildings. Doses due to indoor radon were estimated on the basis of the updated information included in the 2009 International Commission on Radiological Protection statement on radon.

Adhesion of Macroconidia to the Plant Surface and Virulence of Nectria haematococca

To study spore attachment of the cucurbit pathogen Nectria haematococca (anamorph, Fusarium solani f. sp. cucurbitae), mutants with adhesion-deficient macroconidia were isolated. The adhesion-deficient mutants were selected after treatment with N-methyl-N' -nitro-N-nitrosoguanidine followed by repeated enrichment for macroconidia which did not attach to polystyrene. Two independently derived mutants produced macroconidia with an approximately 50% reduction in attachment to polystyrene and to zucchini fruits. When macroconidia were inoculated into wounded zucchini fruits, the adhesion-deficient mutants were as virulent as the wild-type strain. However, in disease assays in which macroconidia were deposited onto the surface of unwounded zucchini, the mutants were less virulent than the wild type. Thus, adhesion of N. haematococca macroconidia to its host surface appears to be a virulence factor.

Genetic and Biochemical Characterization of Nectria haematococca Strains with Adhesive and Adhesion-Reduced Macroconidia

A previous study reported the isolation of two mutants (LE1 and LE2) of the plant pathogenic fungus Nectria haematococca (anamorph, Fusarium solani f. sp. cucurbitae) with macroconidia with reduced ability to adhere (Att) to zucchini fruits and polystyrene. The adhesion-reduced-phenotype in LE1 and LE2 macroconidia is temperature sensitive and dependent on the concentration of nutrients. Classical genetic analysis of progeny derived from LE1 identified a mutation in a genetic locus, named Att1. The 90-kDa glycoprotein and macroconidial tip mucilage which were previously associated with the development of adhesion competence in Att macroconidia are specifically associated with macroconidia; neither is produced on microconidia, which are relatively nonadherent. However, macroconidia of both Att and Att strains produce the 90-kDa glycoprotein and the macroconidial tip mucilage.

Initial use of portable monitoring versus polysomnography to confirm obstructive sleep apnea in symptomatic patients: an economic decision model

BACKGROUND

When using portable (level III and level IV) studies to "rule in" obstructive sleep apnea (OSA) in symptomatic patients, the pre-test probability (P) needs to be sufficiently high to minimize patients with negative tests who require full polysomnography.

METHODS

We used a theoretical decision analysis model to assess the pre-test probability above which it would be appropriate to use portable studies to rule in disease in symptomatic patients with suspected OSA. For the base case, we considered a symptomatically sleepy patient referred with a probability of OSA of P. We determined the lower threshold of P appropriate for a clinical algorithm based upon an initial ambulatory study compared to initial diagnosis with PSG by comparing costs using the PSG algorithm with a diagnostic algorithm involving initial assessment with a portable study.

RESULTS

In our base case, the pre-test probability above which portable testing would be less costly than initial diagnostic PSG would be 0.47. When an initial split night study was compared to portable testing, the pre-test probability above which portable testing was more economically attractive was greater (0.68). Values of P, however, varied considerably depending on values of many variables, including costs of diagnostic testing and CPAP compliance.

CONCLUSIONS

Using a decision model, we have developed a theoretical framework to ascertain the pre-test disease probability above which portable studies would be economically attractive as an initial test in the assessment of patients with suspected OSA.

Sewage and community shower drains are environmental reservoirs of Fusarium solani species complex group 1, a human and plant pathogen

In two recent studies, clinical isolates in the Fusarium solani species complex (FSSC) were sequenced; one of the most common lineages was FSSC Group 1 (FSSC 1), a phylogenetic species that is synonymous with F. solani f. sp. cucurbitae race 2, a pathogen of cucurbit fruits. FSSC 1 was also identified in sink and shower drains in two hospitals. The environmental sources of FSSC 1 are important for understanding the epidemiology of both human and plant diseases caused by this organism. FSSC 1 was detected in sewage influent at all six tested urban wastewater treatment plants (WWTPs) in California with a concentration ranging from 75 to 413 colony-forming units (cfu) l(-1), a mean of 246 +/- 52 cfu l(-1) and a median of 254 cfu l(-1). During the treatment process, the concentration of FSSC 1 in the solid and liquid fractions diminished. FSSC 1 was detected in five and six of 14 community shower drains by culturing and polymerase chain reaction, respectively, whereas FSSC DNA was detected in all drains. FSSC accounted for 17 +/- 6% (n = 14) of the total fungal DNA in the drains. FSSC 1 was rarely isolated from post-harvest cucurbit fruits and was not found in cucurbit fields in California.

Identification of Fusarium solani f. sp. cucurbitae Race 1 and Race 2 with PCR and Production of Disease-Free Pumpkin Seeds

Fusarium solani f. sp. cucurbitae causes a fruit rot of cucurbits and is classified into two races that are actually distinct species: F. solani f. sp. cucurbitae race 1 (Fsc1) and race 2 (Fsc2). Because Fsc1 and Fsc2 are not easily distinguished morphologically, we developed a polymerase chain reaction (PCR) assay for rapid identification. Taxon-specific primers were designed from translation elongation factor 1-α sequences. Because clean seed is critical for disease control, we conducted experiments to determine if we could predict whether seed would be infected based on a visual rating of the fruit at harvest. In two trials in commercial pumpkin fields, eight fruit in each of four categories were selected: asymptomatic fruit, mildly infected fruit, severely infected fruit but without lesions extending into the seed cavity, and severely infected fruit with at least one lesion extending into the seed cavity. Isolates from both lesions and seed were identified as Fsc1 based on the PCR assay. No infected seed were recovered from fruit in which the surface was lesion-free or in which a lesion extended less than midway through the fruit flesh. Consequently, a rapid, visual inspection and exclusion of symptomatic fruit should be sufficient to obtain uninfected seed, even in infested fields.

Treatment options for type 2 diabetes in adolescents and youth: a study of the comparative efficacy of metformin alone or in combination with rosiglitazone or lifestyle intervention in adolescents with type 2 diabetes

Despite the increased prevalence of type 2 diabetes mellitus (T2DM) in the pediatric population, there is limited information about the relative effectiveness of treatment approaches. This article describes the rationale and design of a National Institutes of Health-sponsored multi-site, randomized, parallel group clinical trial designed to test the hypothesis that aggressive reduction in insulin resistance early in the course of T2DM is beneficial for prolongation of glycemic control, as well as improvement in associated abnormalities and risk factors. Specifically, the trial compares treatment with metformin with two alternate approaches, one pharmacologic (combining metformin treatment with rosiglitazone) and one combining metformin with an intensive lifestyle intervention program. The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study recruits 800 patients over a 4-yr period and follows them for a minimum of 2 yr and maximum of 6 yr. Patients are 10-17 yr of age, within 2 yr of diagnosis of diabetes at the time of randomization, lack evidence of autoimmunity, and have sustained C-peptide secretion. The primary outcome is time to loss of glycemic control, defined as a hemoglobin A1c >8% for 6 consecutive months. Secondary outcomes include the effect of the alternative treatments on insulin secretion and resistance, body composition, nutrition, physical activity and fitness, cardiovascular risk monitoring, microvascular complications, quality of life, depression, eating pathology, and resource utilization. TODAY is the first large-scale, systematic study of treatment effectiveness for T2DM in youth. When successfully completed, this study will provide critical new information regarding the natural history of T2DM in youth, the benefits of initiating early aggressive treatment in these patients, and the efficacy of delivering an intensive and sustained lifestyle intervention to children with T2DM.

A class Vb chitin synthase in Colletotrichum graminicola is localized in the growing tips of multiple cell types, in nascent septa, and during septum conversion to an end wall after hyphal breakage

Previous complementation of a chitin synthase class Vb null mutant (Colletotrichum graminicola chsA) indicated that the encoded protein is responsible for approximately 30% of the conidial chitin, is essential for conidial wall strength in media with high water potential, and contributes to strength of hyphal tips. We complemented a chsA null mutant with chsA fused to the green-fluorescent protein (sgfp) gene driven by a heterologous constitutively expressed promoter. Comparisons of the strain with the ectopic chsA-sgfp to the wild type indicated that ChsA-sGFP serves the same biological functions as ChsA in that like the wild type, the chsADelta chsA::sgfp (EC) had conidia that did not explode and hyphal tips that did not swell. Confocal microscopy of ChsA-sGFP (EC) cells stained with the membrane stain FM 4-64 (N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide) indicated that ChsA is localized in the plasma membrane of the following: growing apices of hyphal branches, conidiophores, and falcate and oval conidia; in nascent septa; and in septa that are being converted to an end wall after hyphal breakage. The data support the hypothesis that chsA either directly or indirectly encodes the information for its localization, that ChsA is localized in the plasma membrane, and that the class Vb enzyme produces chitin synthase in multiple cells and after wall breakage.

Fine particles and meteorological conditions are associated with lung function in children with asthma living near two power plants

Fine particles are thought to pose a risk to health, especially for vulnerable groups such as children with asthma. These children are also known to be affected by meteorological and seasonal changes. We assessed the association between air pollution and lung function via peak expiratory flow (PEF), controlling for seasonal changes, meteorological conditions and personal physiological, clinical and sociodemographic measurements, in a panel of schoolchildren with asthma living near two power plants in Israel. Two hundred and eighty-five children with confirmed asthma performed PEF tests and completed a respiratory symptoms diary twice a day. Particulate matter <10 microm in diameter (PM10), particulate matter <2.5 microm in diameter (PM2.5) and meteorological conditions were measured at six fixed stations. Data were analysed using time series analysis-generalized linear model and generalized estimating equations. The models were built under the assumption that any health outcome belongs to a multivariate hierarchical system and depends on meteorological, geophysical and sociocultural variables and pollution factors. No significant differences were found in the demographic (age, gender, mean parental education level, parental smoking habits, place of birth and housing density), physiological (body mass index) and clinical factors (illness severity) between the communities participating in the study. A significant direct effect of PM2.5 on the PEF was found in Ashdod (P=0.000). In Sderot, this effect was through an interaction between PM10 and the sequential day of the year (P=0.000). The main conclusion of this study is that children with asthma are at risk from air pollution and geophysical conditions. Policy makers should take these results into consideration when setting thresholds for environmental protection.

Rootstock Effects on Pistachio Trees Grown in Verticillium dahliae-Infested Soil

ABSTRACT In a field trial in soil infested with Verticillium dahliae, we compared the yield, growth, incidence of symptoms of Verticillium wilt, and mortality of two interspecific hybrid pistachio tree rootstocks (UCBI and PGII) with the standard rootstocks: the V. dahliae-resistant and susceptible Pistacia integerrima and P. atlantica, respectively. After 10 years, the trees were destructively sampled for V. dahliae in the xylem at the graft union. The results indicate that trees on the (P. atlantica 'KAC' x P. integerrima) hybrid UCBI rootstock grew and yielded as well as those on P. integerrima. Trees on the hybrid PGII yielded the least. Analysis of variance and log-linear models indicate that in soil infested with V. dahliae, three associations significantly affect pistachio nut yield. Rootstock affects scion vigor and extent of infection. Third, the extent of infection and scion vigor are inversely associated. Although trees on the P. integerrima rootstock had the highest ratings in a visual assessment of vigor, 65% were infected with V. dahliae in the trunk in the graft region compared with 73% in P. atlantica and 25% in UCBI. Thus, P. integerrima and UCBI have at least one different mechanism for resistance to V. dahliae.

Low back pain--a community-based study of care-seeking and therapeutic effectiveness

PURPOSE

To describe care seeking characteristics among low back pain subjects (LBP); to describe the perceived effectiveness of interventions by recipients of care for LBP; and, to discuss the gap between LBP management guidelines and actual practice in primary care.

METHODS

The population consisted of 555 subjects who were recruited from a cross sectional survey of all inhabitants of a small town in Israel. They reported 1 month LBP and were further probed regarding the characteristics of their pain and pattern of care. Data collection was performed by a self-administered questionnaire.

RESULTS

Some form of care was sought by 78.7% of the participants. More than half (58%) visited a physician, 34.4% were prescribed drug therapy, 37.1% attended physical therapy and 28.6% turned to alternative medicine. Participants with severe pain were more likely to seek care. That was demonstrated by all pain measures (e.g. high Roland and Morris disability scores (8.2+/-5.6 vs 4.4+/-4.1), high symptoms frequency (8.9+/-4.1 vs 7.5+/-3.6) and high pain severity scores (5.6+/-2.2 vs 4.5+/-1.7)). The intervention perceived to be most effective was alternative medicine (graded as 'effective' or 'very effective' by 62.8%), followed by therapeutic exercise programmes (56.9%), bed rest (51.9%) and physical therapy (46.8%).

CONCLUSIONS

Individuals reporting severe LBP were more likely to seek care. The treatment utilities perceived to be most effective were alternative medicine and therapeutic exercises, whereas the least effective were physicians' office visits. A gap was found between clinical guidelines and physicians referrals for other therapeutic interventions.

Incidence of and risk factors for HIV-associated distal sensory polyneuropathy

OBJECTIVE

To assess the incidence of and risk factors for distal sensory polyneuropathy (DSP) in a cohort of HIV-infected subjects.

METHODS

We followed 272 subjects semiannually for up to 30 months. DSP was diagnosed if subjects had decreased or absent ankle jerks, decreased or absent vibratory perception at the toes, or decreased pinprick or temperature in a stocking distribution. Subjects were further classified at each visit as having asymptomatic DSP (ADSP) (signs only) or symptomatic DSP (SDSP) if, in addition to the neurologic signs, paresthesias or pain was reported.

RESULTS

At baseline, 45% of the subjects did not meet criteria for DSP, 20% met criteria for ADSP, and 35% met criteria for SDSP. Dideoxynucleoside therapy was used by 23% of the patients, and this treatment was independent of their neuropathy status. In longitudinal univariate analyses, history of AIDS diagnoses (hazard ratio [HR] = 1.89; p = 0.02) and lower CD4 cell count (HR = 0.69; p = 0.0006) were risk factors for incident DSP (ADSP or SDSP). However, for incident SDSP only, in addition to history of AIDS diagnoses, mood and neurologic (other than DSP) and functional abnormalities were significant risk factors. Functional abnormalities remained a significant risk factor in a multiple regression analysis. The presence of ADSP and the use of dideoxynucleosides at baseline were not significant risk factors for incident SDSP. The Kaplan-Meier estimate of the 1-year incidence of SDSP was 36%.

CONCLUSION

Subjects with moderate-to-severe immunosuppression from HIV infection commonly have SDSP. However, sex, use of dideoxynucleosides, and presence of ADSP were not significant risk factors for SDSP.

Comparative outcomes for individual cognitive-behavior therapy, supportive-expressive group psychotherapy, and sertraline for the treatment of depression in multiple sclerosis

This study compared the efficacy of 3 16-week treatments for depression in 63 patients with multiple sclerosis (MS) and major depressive disorder (MDD): individual cognitive-behavioral therapy (CBT), supportive-expressive group therapy (SEG). and the antidepressant sertraline. Significant reductions were seen from pre- to posttreatment in all measures of depression. Intent-to-treat and completers analyses using the Beck Depression Inventory (BDI; A. T. Beck, C. H. Ward. M. Medelson. J. Mock, & J. Erbaugh, 1961) and MDD diagnosis found that CBT and sertraline were more effective than SEG at reducing depression. These results were largely supported by the BDI-18, which eliminates BDI items confounded with MS. However, the Hamilton Rating Scale for Depression (M. Hamilton, 1960) did not show consistent differences between treatments. Reasons for this inconsistency are discussed. These findings suggest that CBT or sertraline is more likely to be effective in treating MDD in MS compared with supportive group treatments.

Human herpesvirus 6 limbic encephalitis after stem cell transplantation

Central nervous system complications are common in stem cell transplant recipients, but selective involvement of the medial temporal area is unusual. The 5 patients reported here presented after stem cell transplantation with increased hippocampal T2 signal on magnetic resonance imaging and increased hippocampal glucose uptake on [F-18]fluorodeoxyglucose-positron emission tomography (FDG-PET) associated with short-term memory loss, insomnia, and temporal lobe electrographic seizure activity. The initial scalp electroencephalograms (EEGs) failed to detect seizure activity in these patients, although the memory dysfunction along with the magnetic resonance imaging and FDG-PET findings suggested subcortical seizure activity. However, extended EEG monitoring revealed repetitive temporal lobe electrographic seizure activity. Follow-up MRIs in 2 patients and postmortem findings on 1 patient suggested that hippocampal sclerosis had developed following the clinical syndrome. Cerebrospinal fluid studies revealed the presence of human herpesvirus 6, variant B, DNA in all of 3 patients who had lumbar punctures. Immunohistochemical staining for the P41 and P101 human herpesvirus 6 protein antigens showed numerous immunoreactive astrocytes and neurons in the hippocampus of 1 of the patients who died from other causes. Because of its subtle clinical presentation, this syndrome may be underrecognized, but can be diagnosed with appropriate magnetic resonance imaging techniques, EEG monitoring, and cerebrospinal fluid viral studies.

Pesticide applications of copper on perennial crops in California, 1993 to 1998

Inorganic copper is used as a broad-spectrum fungicide and bacteriocide on a variety of agricultural crops. After application, the copper residue typically accumulates in the upper 15 cm of soil. Data from the California Pesticide Use Reports were used to estimate the augmentation of copper in the soil that resulted from pesticide applications for the six years from 1993 to 1998 on 12 crops that are grown without rotation. The estimated mean mg Cu kg(-1) soil added to the upper 15 cm during the six years was the following: walnut (Juglans regia L.), 28; peach [Prunus persica (L.) Batsch var. persica], 22; nectarine [Prunuspersica (L.) Batsch var. nucipersica (Suckow) C.K. Schneid], 19; cherry (Pseudolmedia oxyphyllaria Donn. Sm.), 18; rice (Orvza sativa L.), 16; apricot (Prunus armeniaca L.), 11; orange [Citrus sinensis (L.) Osbeck) and plum (Prunus domestica L. subsp. domestica ), 9; lemon [Citrus limon (L.) Burm.f.] and almond [Prunus dulcis (Mill.) D.A. Webb], 6; pear (Pyrus communis L.), 4; and grape (Vitis vinifera L.), 3. In addition, for the first five of these crops, we estimated the area that was treated with each level of kg Cu ha(-1). For example, for walnut orchards, we estimated that 12 500 ha, or 17% of the planted area, was treated with a quantity of Cu that would increase the total concentration of Cu in the upper 15 cm of soil by at least 50 mg Cu kg(-1) soil. A comparison of the amount of Cu per unit planted area that was applied in the first and second half of the study indicated that the intensity of copper use is either relatively constant or increasing, depending on the crop. The findings are discussed in relation to the potential effect of continued long-term use of Cu pesticides on soil sustainability.

Epidemiological analysis of tuberculosis treatment outcome as a tool for changing TB control policy in Israel

BACKGROUND

Sensing an inadequacy of tuberculosis control due to an influx of TB associated with immigration, we analyzed TB treatment outcome in Israel by population groups.

OBJECTIVES

To provide an epidemiological basis necessary for any new national TB control policy, and to bring it to the attention of the medical profession in Israel and abroad since its results led to a change in Israel's TB control policy.

METHODS

We reviewed all TB cases notified during the period 1990 to September 1992. "New cases" (820 cases, 93.5%) and "re-treatment cases" (57 cases, 6.5%) were analyzed according to three mutually exclusive groups: "successful outcome," "death," and "potentially unsatisfactory outcome" (according to WHO/IUATLD definitions).

RESULTS

Of 820 "new cases," 26.6% had a "satisfactory outcome," 68.5% had a "potentially unsatisfactory outcome" and 4.9% died; compared to 47.4%, 45.6% and 7% among 57 "re-treatment cases," respectively. Using logistic regression analysis, outcome was associated with the district health office (P < 0.0001), the TB "experience" of the notifying clinic (P < 0.0001), and the form of TB (P = 0.02). No significant relationships were obtained for population groups, gender and age, interval between arrival in Israel and TB notification, and bacteriological results.

CONCLUSIONS

Non-supervised TB treatment resulted in poor outcomes regardless of population groups. Better outcomes occurred in the larger TB clinics. Therefore, in addition to measures such as adequate drug supplies, reorganization of TB laboratories and training of TB personnel, we recommend the "directly observed treatment short-course" for all cases as well as reducing the number of treatment centers thereby increasing their case load.

Low back pain: reliability of a set of pain measurement tools

OBJECTIVES

To determine the reliability and internal consistency of a set of low back pain (LBP)-related measurement tools and to determine whether they are appropriate for use in a large-scale, community-based sample in Israel.

DESIGN

Test-retest reliability study, with an interval of 2 to 14 days between test and retest.

SETTING

Physiotherapy clinics.

PARTICIPANTS

One hundred fifty-one patients with LBP.

MAIN OUTCOME MEASURES

The Modified Roland-Morris Disability Questionnaire (MRMQ); a simple verbal pain severity scale; and modified pain symptoms frequency and bothersomeness indices. Three measures of variables with potential association with LBP were also used: a Fear-Avoidance Beliefs Questionnaire (FABQ), work satisfaction scale, and the Baecke Physical Activity Questionnaire (BPAQ).

RESULTS

Test-retest reliability was high for the MRMQ, pain symptom indices, work index of the FABQ, and occupational activity index of the BPAQ; the internal consistency of the MRMQ and FABQ work index were also high (intraclass correlation coefficient >or= .89; alpha = .89).

CONCLUSIONS

Most measurement tools are reliable and suitable for community LBP studies in Israel.

Factors associated with incident human immunodeficiency virus-dementia

BACKGROUND

Antecedents to human immunodeficiency virus-dementia (HIV-D) are poorly understood.

OBJECTIVE

To identify risk factors for HIV-D.

METHODS

Subjects who are positive for HIV who have CD4+ counts either below 200/microL or below 300/microL with evidence of cognitive impairment were enrolled in this study. Neurologic, cognitive, functional, and laboratory assessments were done semiannually for up to 30 months. Human immunodeficiency virus-dementia was diagnosed using American Academy of Neurology criteria for probable HIV-1-associated dementia complex.

RESULTS

One hundred forty-six nondemented patients were enrolled, 45 of whom subsequently met criteria for incident HIV-D. In univariate analyses using the Cox proportional hazards regression model, the following variables were significantly associated with time to develop dementia: cognitive: abnormal scores on Timed Gait, Verbal Fluency, Grooved Pegboard, and Digit Symbol tests; attention-memory, psychomotor, and executive function domain scores; and the diagnosis of minor cognitive/motor disorder; neurologic and medical: increased abnormalities on the neurologic examination, extrapyramidal signs, history of HIV-related medical symptoms; functional: higher reported role or physical function difficulties. Depression was also a strong risk factor, along with sex, hematocrit, hemoglobin, and beta2-microglobulin levels. In a multivariate model that used cognitive domain scores, covariates with significant hazard ratios included depression, executive dysfunction, and the presence of minor cognitive/motor disorder.

CONCLUSION

Cognitive deficits, minor cognitive/motor disorder, and depression may be early manifestations of HIV-D.

Clinical trials in HIV-associated cognitive impairment: cognitive and functional outcomes

Cognitive and functional outcomes are of primary interest in the design of efficacy trials in HIV-associated cognitive impairment. In a longitudinal cohort study, weak associations were found between measures of cognitive performance and commonly used measures of daily functioning (mostly self-report measures) in HIV-infected individuals. Modifications of current functional scales or new functional instruments are needed to assess the clinical relevance of cognitive changes in clinical trials of HIV-associated cognitive impairment.

Lipophosphoglycan is a virulence factor distinct from related glycoconjugates in the protozoan parasite Leishmania major

Protozoan parasites of the genus Leishmania undergo a complex life cycle involving transmission by biting sand flies and replication within mammalian macrophage phagolysosomes. A major component of the Leishmania surface coat is the glycosylphosphatidylinositol (GPI)-anchored polysaccharide called lipophosphoglycan (LPG). LPG has been proposed to play many roles in the infectious cycle, including protection against complement and oxidants, serving as the major ligand for macrophage adhesion, and as a key factor mitigating host responses by deactivation of macrophage signaling pathways. However, all structural domains of LPG are shared by other major surface or secretory products, providing a biochemical redundancy that compromises the ability of in vitro tests to establish whether LPG itself is a virulence factor. To study truly lpg(-) parasites, we generated Leishmania major lacking the gene LPG1 [encoding a putative galactofuranosyl (Gal(f)) transferase] by targeted gene disruption. The lpg1(-) parasites lacked LPG but contained normal levels of related glycoconjugates and GPI-anchored proteins. Infections of susceptible mice and macrophages in vitro showed that these lpg(-) Leishmania were highly attenuated. Significantly and in contrast to previous LPG mutants, reintroduction of LPG1 into the lpg(-) parasites restored virulence. Thus, genetic approaches allow dissection of the roles of this complex family of interrelated parasite virulence factors, and definitively establish the role of LPG itself as a parasite virulence factor. Because the lpg1(-) mutant continue to synthesize bulk GPI-anchored Gal(f)-containing glycolipids other than LPG, a second pathway distinct from the Golgi-associated LPG synthetic compartment must exist.

The role of phosphoglycans in Leishmania-sand fly interactions

Leishmania promastigotes synthesize an abundance of phosphoglycans, either attached to the cell surface through phosphatidylinositol anchors (lipophosphoglycan, LPG) or secreted as protein-containing glycoconjugates. These phosphoglycans are thought to promote the survival of the parasite within both its vertebrate and invertebrate hosts. The relative contributions of different phosphoglycan-containing molecules in Leishmania-sand fly interactions were tested by using mutants specifically deficient in either total phosphoglycans or LPG alone. Leishmania donovani promastigotes deficient in both LPG and protein-linked phosphoglycans because of loss of LPG2 (encoding the Golgi GDP-Man transporter) failed to survive the hydrolytic environment within the early blood-fed midgut. In contrast, L. donovani and Leishmania major mutants deficient solely in LPG expression because of loss of LPG1 (involved in biosynthesis of the core oligosaccharide LPG domain) had only a slight reduction in the survival and growth of promastigotes within the early blood-fed midgut. The ability of the LPG1-deficient promastigotes to persist in the midgut after blood meal excretion was completely lost, and this defect was correlated with their inability to bind to midgut epithelial cells in vitro. For both mutants, when phosphoglycan expression was restored to wild-type levels by reintroduction of LPG1 or LPG2 (as appropriate), then the wild-type phenotype was also restored. We conclude, first, that LPG is not essential for survival in the early blood-fed midgut but, along with other secreted phosphoglycan-containing glycoconjugates, can protect promastigotes from the digestive enzymes in the gut and, second, that LPG is required to mediate midgut attachment and to maintain infection in the fly during excretion of the digested blood meal.

Lymphotropic virions affect chemokine receptor-mediated neural signaling and apoptosis: implications for human immunodeficiency virus type 1-associated dementia

Chemokine receptors pivotal for human immunodeficiency virus type 1 (HIV-1) infection in lymphocytes and macrophages (CCR3, CCR5, and CXCR4) are expressed on neural cells (microglia, astrocytes, and/or neurons). It is these cells which are damaged during progressive HIV-1 infection of the central nervous system. We theorize that viral coreceptors could effect neural cell damage during HIV-1-associated dementia (HAD) without simultaneously affecting viral replication. To these ends, we studied the ability of diverse viral strains to affect intracellular signaling and apoptosis of neurons, astrocytes, and monocyte-derived macrophages. Inhibition of cyclic AMP, activation of inositol 1,4,5-trisphosphate, and apoptosis were induced by diverse HIV-1 strains, principally in neurons. Virions from T-cell-tropic (T-tropic) strains (MN, IIIB, and Lai) produced the most significant alterations in signaling of neurons and astrocytes. The HIV-1 envelope glycoprotein, gp120, induced markedly less neural damage than purified virions. Macrophage-tropic (M-tropic) strains (ADA, JR-FL, Bal, MS-CSF, and DJV) produced the least neural damage, while 89.6, a dual-tropic HIV-1 strain, elicited intermediate neural cell damage. All T-tropic strain-mediated neuronal impairments were blocked by the CXCR4 antibody, 12G5. In contrast, the M-tropic strains were only partially blocked by 12G5. CXCR4-mediated neuronal apoptosis was confirmed in pure populations of rat cerebellar granule neurons and was blocked by HA1004, an inhibitor of calcium/calmodulin-dependent protein kinase II, protein kinase A, and protein kinase C. Taken together, these results suggest that progeny HIV-1 virions can influence neuronal signal transduction and apoptosis. This process occurs, in part, through CXCR4 and is independent of CD4 binding. T-tropic viruses that traffic in and out of the brain during progressive HIV-1 disease may play an important role in HAD neuropathogenesis.

Evaluation of triage decisions for intensive care admission

OBJECTIVE

To assess physician decision-making in triage for intensive care and how judgments impact on patient survival.

DESIGN

Prospective, descriptive study.

SETTING

General intensive care unit, university medical center.

INTERVENTIONS

All patients triaged for admission to a general intensive care unit were studied. Information was collected for the patient's age, diagnoses, surgical status, admission purpose, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and mortality. The number of available beds at the time of triage and reasons for refused admission were obtained.

MEASUREMENTS AND MAIN RESULTS

Of 382 patients, 290 were admitted, 92 (24%) were refused admission, and 31 were admitted at a later time. Differences between admission diagnoses were found between patients admitted or not admitted (p < .001). Patients refused admission had higher APACHE II scores (15.6+/-1.5 admitted later and 15.8+/-1.4 never admitted) than did admitted patients (12.1+/-.4; p < .001). The frequency of admitting patients decreased when the intensive care unit was full (p < .001). Multivariate analysis revealed that triage to intensive care correlated with age, a full unit, surgical status, and diagnoses. Hospital mortality was lower in admitted (14%) than in refused patients (36% admitted later and 46% never admitted; p < .01) and in admitted patients with APACHE II scores of 11 to 20 (p = .02). The 28-day survival of patients was greater for admitted patients compared with patients never admitted (p = .01).

CONCLUSIONS

Physicians triage patients to intensive care based on the number of beds available, the admission diagnosis, severity of disease, age, and operative status. Admitting patients to intensive care is associated with a lower mortality rate, especially in patients with APACHE scores of 11 to 20.

Entrainment/mapping criteria for the prediction of termination of ventricular tachycardia by single radiofrequency lesion in patients with coronary artery disease

BACKGROUND

A variety of mapping criteria have been proposed to localize critical sites at which radiofrequency (RF) can predictably terminate reentrant ventricular tachycardia (VT) caused by coronary artery disease. The purpose of this study was to determine the accuracy of using a combination of 3 mapping criteria in predicting termination of VT by a single RF lesion.

METHODS AND RESULTS

Fifteen consecutive patients with coronary artery disease and recurrent sustained VT underwent an attempted RF ablation of 20 monomorphic VTs. Successful termination of VT by a single RF lesion was predicted if all the following mapping criteria were met: (1) an exact QRS match in the 12-lead ECG during entrainment; (2) a return cycle length </=10 ms of the VT cycle length; (3) presystolic potentials (<70% of VT cycle length) with an activation time to the QRS within 10 ms of the stimulus to QRS. Inability to meet these 3 criteria was considered to predict failure of VT termination by RF energy at that site. RF ablation was applied to 44 left ventricular sites in 20 VTs at which at least 1 of the mapping criteria was met. VT was terminated with a single RF lesion in 19 of 19 sites meeting all criteria; RF failed to terminate VT at 24 of 25 sites at which all 3 criteria were not met (P<0.0005).

CONCLUSIONS

To maximize success and minimize the number of RF lesions in patients with infarct-related VT, all the above 3 mapping criteria should be met before the application of RF energy.

Neonatal outcome of inborn and transported very-low-birth-weight infants: relevance of perinatal factors

OBJECTIVE

To compare the neonatal outcome (survival, intraventricular hemorrhage and bronchopulmonary dysplasia) of inborn and outborn very-low-birth-weight infants accounting for sociodemographic, obstetric and perinatal variables.

STUDY DESIGN

Ninety-one premature infants with birth weights of 750-1250 g delivered between 1990 and 1994 in a hospital providing neonatal intensive care were compared with 76 premature babies delivered in a referring hospital. In the statistical analysis, variables with a statistically significant association with the outcome variables and dissimilar distributions in the two hospitals were identified and entered together with the hospital of birth as explanatory variables in a logistic regression.

RESULTS

No statistically significant differences between the outcome variables of the two populations examined were observed, whether before or after accounting for the covariates. The odds ratios (outborns relative to inborns) were 1.18 for mortality, 1.25 for bronchopulmonary dysplasia and 1.53 for severe intraventricular hemorrhage. In the multivariate analyses, respiratory distress syndrome was significantly associated with mortality; both low birth weight and the presence of respiratory distress syndrome were associated with the development of bronchopulmonary dysplasia; the evolvement of severe intraventricular hemorrhage was associated with respiratory distress syndrome, initial low Apgar score, advanced multiparity and delivery at the 28-29th week compared to the 23rd-27th week. Antenatal steroid administration had a protective effect.

CONCLUSION

Our results concur with the notion that a tertiary center is the optimal location for delivery of the high risk neonate. Improvement in medical and nursing care prenatally and at delivery and transportation, including frequent administration of antenatal steroids and earlier administration of surfactant prior to transportation, may minimize the disadvantage of delivery in a referring hospital.

The contribution of multiple data sources to a clinical audit of lymphoma in a teaching hospital

OBJECTIVE

To assess the independent contribution of data sources used for case ascertainment in a clinical audit of the outcome of lymphoma patients in our institution.

DESIGN

In the absence of a unified register of lymphoma patients diagnosed and/or treated in our institution, we used an elective approach to case ascertainment. Sources included two internal databases (computerized discharge data for hospitalizations and outpatient oncology database) and one external (Israel Cancer Registry) database. Histologic diagnosis was confirmed by search of on-line pathology files or discharge summaries. Demographic, histologic and survival characteristics were compared among patients identified through each data source. Survival was assessed via record linkage with the Population Registry.

SETTING

A tertiary care university teaching hospital.

STUDY PARTICIPANTS

Seven hundred and twelve patients with lymphoma diagnosed between 1987 and 1992.

RESULTS

All three sources contributed independently to the total, with the majority (583 or 82%) via hospitalizations. Overlap among the sources was minimal with only 73 (10.3%) of the patients being common to all three sources. Differences (P < 0.05) in the age distribution, country of birth and population groups (defined by religion) as well as histologic diagnoses among the sources were noted. In addition, survival of those ascertained via the outpatient database was higher than those ascertained from other sources (P=0.02 for Hodgkin's disease) even after controlling for age.

CONCLUSIONS

The use of multiple data sources for case ascertainment in clinical audit is justified when no patient register exists. The results indicate that use of a single internal data source would have resulted both in an underestimate of the scope of lymphoma in our institution and significant bias in terms of patient characteristics and outcome.

Transformation-mediated developmental mutants of Glomerella graminicola

Glomerella graminicola transformants were generated by insertional plasmid mutagenesis. Five transformants with developmental mutant phenotypes that segregated in crosses as single-gene mutations were selected. In four transformants, the mutant phenotype cosegregated with the inserted plasmid DNA. At least three of the mutants result from gene disruption, as demonstrated by recovery of the mutant phenotypes after transformation of wild type with "rescued" plasmid DNA. Whereas the wild type produces uninucleate, salmon-colored conidia, the tagged mutant M26 has white conidia. After exposure to either UV light or singlet oxygen, the percentage germination of M26 conidia is reduced compared to that of the wild-type conidia, indicating that the spore pigment confers protection from UV light and singlet oxygen. The tagged mutant T30 has weakened walls; falcate conidia rupture and hyphae have swollen regions unless the medium is amended with an osmoticum. The tagged mutant T29 has falcate conidia with one to four nuclei; wild-type falcate conidia are uninucleate. Two other mutants, one which grows slowly and one having conidia with increased curvature, are also described.