Impact of angiotension I converting enzyme gene I/D polymorphism on running performance, lipid, and biochemical parameters in ultra-marathoners

The insertion (I) or deletion (D) polymorphism in the angiotension I converting enzyme gene, (ACE I/D, rs1799752) is associated with human exercise endurance and performance. However, most of the aforementioned studies focus on marathons, swimming, and triathlons, while the ACE polymorphism in ultra-marathoners has not yet been reported. We studied the impact of ACE I/D polymorphism in ultra-marathoners and investigated its relationship with lipid profiles, interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP) levels in runners before and after ultra-marathon racing.This observational study used data from a 100-km ultra-marathon in Taipei, Taiwan. Twenty-four male participants were analyzed for their ACE insertion/deletion polymorphism, lipid profiles, hs-CRP, IL-6 in serum immediately before and after ultra-marathon running.In our 24 subjects analyzed, 7, 14, and 3 subjects were of I/I, I/D, and D/D genotypes, respectively. Runners with the D polymorphism (I/D and D/D) showed a trend of better performance in the 100-km ultra-marathon (measured by completion time in minutes, P = .036). In this group, the previous best marathon performance was also significantly better than the I/I group (P = .047). After adjusting for body mass index (BMI), the difference in performance was not significant. Ketone levels, IL-6, and hs-CRP levels were highly increased at immediately and 24-hour post-race. No correlation was found between different ACE polymorphisms and common biochemical parameters examined.We report the first study in the impact of the ACE I/D (rs1799752) on ultra-marathoners. Presence of the D polymorphism in ACE gene is associated with better performance, although the BMI of the runners contribute as a major factor. There was no difference in the biochemical or lipid parameters measured among different ACE polymorphisms.

Changes of heart rate variability predicting patients with acute exacerbation of chronic obstructive pulmonary disease requiring hospitalization after Emergency Department treatment

BACKGROUND

Indexes of heart rate variability (HRV) appear to reflect severity and may have prognostic value in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We hypothesized that AECOPD without adequate treatment response would demonstrate impaired cardiac autonomic regulation and changes in HRV after emergency department (ED) treatment.

METHODS

A prospective study of measuring HRV in admitted and discharged patients with AECOPD shortly after ED arrival and again 24 h after treatment.

RESULTS

Total consecutive 33 patients (18 admitted and 15 discharged, age 77.1 ± 1.6 years) were enrolled. Among admitted patients, high frequency in normalized unit (HF%) was significantly lower (P < 0.001) while Ratio of LF to HF (LF/HF ratio) was significantly higher (P < 0.001) than discharged. 24 h after treatment, admitted patients had a significantly larger increase in HF% (P < 0.002) and larger decrease in LF/HF ratio (P < 0.05) than discharged. ROC curve analysis show the relative potential of the ΔHF% and ΔLF/HF% in the discrimination of groups. The area under the ROC curve between the 2 groups was 0.807 (P < 0.01) and 0.722 (P < 0.05), respectively. The best cut-off value for the admission between groups was ΔHF% >7.1 and ΔLF/HF% ≦-0.39.

CONCLUSION

Patients with AECOPD requiring admission after ED treatment had a greater increase in HF% and greater decrease in LF/HF ratio compared to those discharged. Our study demonstrates patient with ΔHF% was >7.1 or a ΔLF/HF% ≦-0.39 require admission despite 24 h of ED treatment.

Dosimetric comparison of different treatment modalities for stereotactic radiotherapy

Background

The modalities for performing stereotactic radiotherapy (SRT) on the brain include the cone-based linear accelerator (linac), the flattening filter-free (FFF) volumetric modulated arc therapy (VMAT) linac, and tomotherapy. In this study, the cone-based linac, FFF-VMAT linac, and tomotherapy modalities were evaluated by measuring the differences in doses delivered during brain SRT and experimentally assessing the accuracy of the output radiation doses through clinical measurements.

Methods

We employed a homemade acrylic dosimetry phantom representing the head, within which a thermoluminescent dosimeter (TLD) and radiochromic EBT3 film were installed. Using the conformity/gradient index (CGI) and Paddick methods, the quality of the doses delivered by the various SRT modalities was evaluated. The quality indicators included the uniformity, conformity, and gradient indices. TLDs and EBT3 films were used to experimentally assess the accuracy of the SRT dose output.

Results

The dose homogeneity indices of all the treatment modalities were lower than 1.25. The cone-based linac had the best conformity for all tumors, regardless of the tumor location and size, followed by the FFF-VMAT linac; tomography was the worst-performing treatment modality in this regard. The cone-based linac had the best gradient, regardless of the tumor location and size, whereas the FFF-VMAT linac had a better gradient than tomotherapy for a large tumor diameter (28 mm). The TLD and EBT3 measurements of the dose at the center of tumors indicated that the average difference between the measurements and the calculated dose was generally less than 4%. When the 3% 3-mm gamma passing rate metric was used, the average passing rates of all three treatment modalities exceeded 98%.

Conclusions

Regarding the dose, the cone-based linac had the best conformity and steepest dose gradient for tumors of different sizes and distances from the brainstem. The results of this study suggest that SRT should be performed using the cone-based linac on tumors that require treatment plans with a steep dose gradient, even as the tumor is slightly irregular, we should also consider using a high dose gradient of the cone base to treat and protect the normal tissue. If normal tissues require special protection exist at positions that are superior or inferior to the tumor, we can consider using tomotherapy or Cone base with couch at 0° for treatment.

Spontaneous Intramural Intestinal Hemorrhage versus Acute Mesenteric Ischemia by CT Evaluation

Objective The purpose of our study was to differentiate the imaging findings of patients with spontaneous intramural intestinal hemorrhage (SIIH) from those with acute mesenteric ischemia (AMI) after abdominal computed tomography (CT) survey in the emergency department. Methods We retrospectively included 83 patients diagnosed with SIIH or AMI after abdominal CT. Results The mean ages of 30 SIIH patients and 53 AMI patients were 74.4±14.6 years and 75.8±11.2 years, respectively. Patients with SIIH had significantly thicker maximal intestinal wall thickening (14.8±3.9 vs. 10.9 ±4.1, p<0.001), a lower rate of ileum involvement (26.7% vs. 77.4%, p<0.001) and a higher rate of ascites (96.7% vs. 64.2%, p<0.001) compared with patients with AMI. Neither pneumatosis intestinalis (p<0.001) nor portomesenteric gas (p<0.01) were detected in SIIH patients but were observed in AMI patients. A receiver-operating characteristic (ROC) curve analysis showed that the optimal cut-off value for maximal intestinal wall thickening between groups was 10.4 mm and the area under the ROC curve between groups was 0.752 (p<0.0001). A multiple logistic regression analysis showed that the independent predictors of SIIH were non-involvement of the ileum (odds ratio, OR, 6.998; p=0.001), maximal intestinal wall thickening ≥10.4 mm (OR, 5.748; p=0.040) and ascites (OR, 13.348; p=0.023). The area under the ROC curve for the model was 0.854 (p<0.001). Conclusion The independent predictors of SIIH from AMI after abdominal CT in acute abdominal patients include non-involvement of the ileum, intestinal wall thickening ≥10.4 mm, and ascites.

How to differentiate spontaneous intramural intestinal hemorrhage from acute mesenteric ischemia

OBJECTS

The purpose of our study was to assess the diagnostic values of laboratory tests to differentiate spontaneous intramural intestinal hemorrhage (SIIH) from acute mesenteric ischemia (AMI) after abdominal computed tomography (CT) survey in the emergency department (ED).

METHOD

We retrospectively included 76 patients diagnosed SIIH or AMI after abdominal CT.

RESULTS

The mean ages of 28 SIIH patients and 48 AMI patients were 75.9 ± 13.7 years and 75.8 ± 11.6 years, respectively. Patients with SIIH had significantly higher rate of Coumadin use (P < .001) and localized tenderness (P < .05). In laboratory findings, SIIH patients had prolonged prothrombin time (PT) (83.6 ± 30.0 vs. 13.4 ± 3.2, P < .001), lower blood urea nitrogen (P < .05), lower creatinine (P < .05), and lower creatine kinase (P < .05). Prolonged PT showed good discriminative value to differentiate acute abdomen patients with SIIH from AMI after abdominal CT, with an area under the receiver operating characteristic curve of 0.980 (95% confidence interval, 0.918-0.998; P < .0001). Prolonged PT cut-off value of ≧22.5 seconds had a sensitivity of 92.9% and a specificity of 100%. Logistic regression analysis identified prolonged PT as an independent predictor of SIIH (odds ratio, OR, 22.2; P = .007).

CONCLUSION

Abdominal pain patients with either SIIH or AMI are rare in the ED, but abdominal CT sometimes cannot help to differentiate them due to similar CT findings. Prolonged PT might help emergency physicians and surgeons differentiate SIIH from AMI in such cases.

Non-compressibility ratio of sonography in deep venous thrombosis

BACKGROUND

The risk of post-thrombotic syndrome and pulmonary embolism can be increased if there is failure to diagnose deep venous thrombosis (DVT) promptly. Emergency physicians (EPs) need a quick and readily available test to diagnose, treat and help them decide whether to discharge or admit DVT patients in a timely manner. The aim of this study was to investigate the value of the non-compressibility ratio of thrombosed veins in DVT patients, and give EPs an objective value to aid them in their decision-making with regard to DVT patients in the emergency department.

METHODS

We reviewed 34 adult patients with DVT diagnosed by sonography in an emergency department. Medical records including demographic data and sonography results were retrospectively reviewed and analyzed.

RESULTS

Mean age was 72.9 ± 16.5 years. Group I comprised 14 patients (41.2%) who had DVT in the popliteal and femoral veins. Group II comprised 8 patients (23.5%) who had DVT isolated to the popliteal vein and 12 patients (35.3%) who had DVT isolated to the femoral vein. Group I had a significantly higher non-compressibility ratio than Group II (93.4 ± 6.2% vs. 80.1 ± 19.2%, p < 0.05). The area under the receiver operating characteristic curve of the non-compressibility ratio between discriminating groups was 0.711 (95% confidence interval, 0.527-0.854; p < 0.05). The clinical prognostic score of Group I was significantly higher than that of Group II (6.2 ± 1.8 vs. 4.1 ± 2.6, p < 0.05). There was a significant positive correlation between the non-compressibility ratio of the thrombosed vein and the clinical prognostic score (p = 0.001).

CONCLUSION

The non-compressibility ratio of the thrombosed vein provides EPs with an objective test to evaluate the severity of DVT and to admit patients for consideration of adverse outcomes.

Anticoagulant-induced intramural intestinal hemorrhage

BACKGROUND

Long-term use of warfarin can provide benefits in the treatment of many diseases, but adverse bleeding events are unpreventable because of a narrow therapeutic range.

OBJECTIVE

The aim of this retrospective chart review with data abstraction was to investigate the clinical presentations of intestinal intramural hemorrhage in emergency department (ED) patients.

METHODS

We reviewed the cases of 17 patients with acute abdominal pain in our ED. Medical records including demographic data and results of abdominal computed tomography were retrospectively reviewed and analyzed.

RESULTS

The mean ± SD age of the reviewed patients was 77.7 ± 8.5 years (range, 60-93 years). The mean ± SD duration from onset of symptoms to ED visit was 2.5 ± 1.3 days (range, 1-5 days). All patients had abdominal pain, and 64.7% had nausea/vomiting. A total of 64.7% of patients had peritoneal signs. The jejunum was most commonly involved (88.2% of all cases). The maximal mean ± SD wall thickening of the bowel was 14.1 ± 4.4 mm (range, 7.4-26.7 mm), and the estimated mean ± SD length was 35.6 ± 24.4 cm (range, 9-105 cm). The mean ± SD prothrombin time and activated partial thromboplastin time were prolonged to 86.5 ± 26.9 and 116.2 ± 43.1 seconds, respectively. All patients received medical treatment and survived. At the last follow-up (mean, 27.4 months), none of the patients had recurrence of intestinal intramural hemorrhage or intestinal obstruction.

CONCLUSION

Prolonged prothrombin time and drug history can indicate the possibility of intramural intestinal hemorrhage, and abdominal computed tomography may help to exclude surgical diseases and prevent unnecessary surgery.

Ultrastructural changes of posterior lingual glands after hypoglossal denervation in hamsters

Posterior lingual glands consist of two sets of minor salivary glands that serve important functions in oral physiology. To investigate the hypothesis that the hypoglossal nerve provides sympathetic innervation to the posterior lingual glands, we examined ultrastructural changes in the glands following hypoglossal denervation. In the posterior deep lingual glands (of von Ebner), the serous acinar cells showed a decrease in the number of secretory granules and an increase in lipofuscin accumulation. The ratios of cells containing lipofuscin granules were 11.39, 36.49 and 50.46%, respectively, of the control, 3- and 7-day post-axotomy glands (P < 0.001). Intraepithelial phagocytotic activity was increased. The mucous acinar cells in the posterior superficial lingual glands (of Weber) also showed degenerative changes after hypoglossal denervation. One week after nerve transection, marked cytoplasmic vacuolation and fragmentation of organelles were frequently observed. Degenerative changes were also found in unmyelinated axons associated with the glands. We provide the first evidence of the structural and functional connections between the sympathetic component of the hypoglossal nerve and posterior lingual glands.

IgE-binding epitopes of the American cockroach Per a 3 allergen

BACKGROUND

The Per a 3 is a species-specific allergen of the American cockroach (Periplaneta americana) related to insect hemolymph proteins and includes four known isoallergens. This study aimed to identify Per a 3 linear IgE-binding epitopes.

METHODS

Per a 3 recombinant fragments were generated from the recombinant Per a 3.01 allergen (685 amino acid residues) by using existing restriction sites or by using polymerase chain reaction products, and expressed in Escherichia coli. Antigenicities were assessed by immunoblotting, enzyme-linked immunosorbent assay (ELISA), and binding inhibition with human IgE.

RESULTS

Human IgE recognized recombinant fragments 340-425, 466-579, 502-595, and 595-636 as revealed by immunoblotting and ELISA. On the other hand, the N-terminal fragment 1-399, recombinants 410-443, 472-551, 502-579, 606-636, and the C-terminal fragment 636-685 were unable to bind human IgE. Amino acid sequences 400-409, 466-471, 580-595, and 595-605 were shown to be required for IgE binding to the Per a 3.01 allergen, suggesting that the C-terminus contains most of the IgE-binding sites. Four peptides corresponding to these IgE-binding amino acid sequences were synthesized. These peptides reacted with most sera (62.5-87.5%) tested as revealed by ELISA, demonstrating a heterogeneous IgE-binding response. Moreover, preincubation of IgE-positive recombinant proteins and synthetic peptides with atopic IgE resulted in marked inhibition of the IgE binding to Per a 3.01 allergen. Amino acid sequences 400TVLRDPVFYQ409, 466NNVDQI471, 580VDKGHNYCGYPENLLI595, and 595IPKGKKGGQAY605 of the major recombinant American cockroach Per a 3.01 allergen were involved in IgE binding.

CONCLUSION

These findings will advance our understanding of the antigenic structures responsible for allergenicity to the American cockroach, thereby providing strategies for the development of immunotherapies.

Benzene exposure and hematopoietic mortality: A long-term epidemiologic risk assessment

BACKGROUND

Previous studies of a cohort of rubber hydrochloride workers indicated an association between benzene exposure and excess mortality from leukemia and multiple myeloma. To determine whether risks remain elevated with increasing time since plant shutdown, we extended follow-up from 1981 through 1996.

MATERIALS AND METHODS

We evaluated risk using standardized mortality ratios (SMR) and generalized Cox proportional hazards regression models.

RESULTS

Five new leukemia cases were observed in benzene-exposed white males, but the summary SMR for this group declined from 3.37 (95% CI = 1.54-6.41) to 2.56 (95% CI = 1.43-4.22). In regression models, cumulative exposure was significantly associated with elevated relative risks for leukemia mortality. Four new multiple myeloma deaths occurred, three of which were in workers judged to be unexposed.

CONCLUSIONS

These findings reaffirm the leukemogenic effects of benzene exposure and suggest that excess risk diminishes with time.

Translation drag coefficient of a self-similar assembly of spheres immersed in an incompressible fluid

On the basis of deterministic fractals and the Rotne-Prager hydrodynamic interaction tensor, we confirm the asymptotic as well as the finite size scaling of the friction coefficient lambda of a self-similar structure. The fractal assembly is made of N spheres with its dimension varying from D < 1 to D = 3. The number of spheres can be as high as N approximately O(10(4)). The asymptotic scaling behavior of the friction coefficient per sphere is lambda approximately N(1/D-1) for D > 1, lambda approximately (lnN)(-1) for D = 1, and lambda approximately N(0) for D < 1. The crossover behavior indicates that while in the regime of D > 1 the hydrodynamic screening effect grows with the size, for D<1 it is limited in a finite range, which decays with decreasing D.

Comparison of immunogenicity of simultaneous and nonsimultaneous vaccination with MMR and JE vaccine among 15-month-old children

To evaluate the immunogenicity of measles- mumps- rubella (MMR) vaccination with Japanese encephalitis (JE) vaccine nonsimultaneously and simultaneously, 145 babies, aged 15 months were enrolled into two groups. Group A received MMR and JE vaccines nonsimultaneously at an interval of 6 weeks; group B received the vaccinations simultaneously. Antibody titers of MMR and JE were detected before and 8 weeks after vaccination. A total of 118 babies (61 in group A; 57 in group B) completed the study. In group A, mean increments of logarithmic geometric mean titers (GMTs) of MMR and JE were 4.51, 5.93, 4.07 and 1.99; seroresponse rates were 100% (61/61), 77.05% (47/61), 96.72% (59/61) and 59.02% (36/61) respectively. In group B, mean increments of logarithmic GMTs of MMR and JE were 4.35, 5.37, 4.44 and 1.93; seroresponse rates were 98.25% (56/57), 77.19% (44/57), 98.25% (56/57) and 57.89% (33/57) respectively. There were no significant differences between these two groups. These results suggest that simultaneous and nonsimultaneous vaccination with MMR and JE vaccines were similar in immunogenicity.

Prediction of human transplantation arteriopathy and coronary events with lung/heart count ratios during intravenous dipyridamole thallium-201 imaging

BACKGROUND

Cardiac allograft arteriopathy often limits long-term survival in transplantation recipients but has been difficult to detect by standard diagnostic methods. Because of the diffuse nature of transplantation coronary disease, we postulated that a lung/heart ratio during dipyridamole thallium imaging might better predict arteriopathy-related complications than diagnostic methods that detect discrete luminal stenoses.

METHODS AND RESULTS

Sixty-six unselected heart transplantation recipients were evaluated with annual coronary arteriograms, endomyocardial biopsy, and intravenous dipyridamole thallium testing (initial study group). The mean lung/heart ratio on an anterior planar image was 0.40 for all patients; therefore <0.40 was arbitrarily defined as normal. After October 1992, 98 patients were tested (validation study group) and a lung/heart ratio cutoff of 0.40 was evaluated prospectively. Coronary end points were defined as (1) at least 1 coronary artery stenosis >/=50% of the luminal diameter, (2) sudden cardiac death, and (3) acute myocardial infarction. Stepwise logistic regression analysis was performed to identify independent predictors of future coronary end points. For the initial study group, the lung/heart ratio on the first annual thallium study was the only independent predictor of subsequent cardiac end points (0.47 +/- 0.13 [SD] with end points vs 0.38 +/- 0.11 without end points, P <.05). For the validation study group, independent predictors of subsequent coronary events included the lung/heart ratio and the radionuclide left ventricular ejection fraction. No patient with a lung/heart ratio <0.40 and a left ventricular ejection fraction >/=0.50 developed a cardiac event during 21 +/- 11 months of follow-up.

CONCLUSIONS

A lung/heart ratio >/=0.40 on dipyridamole thallium testing is a sensitive predictor of coronary events after heart transplantation. Patients with heart transplantion who have a lung/heart ratio <0.40 and normal systolic left ventricular function are at low risk for subsequent coronary events and may not require annual surveillance by coronary arteriography.

An empirical comparison of lead exposure pathway models

Structural equation modeling is a statistical method for partitioning the variance in a set of interrelated multivariate outcomes into that which is due to direct, indirect, and covariate (exogenous) effects. Despite this model's flexibility to handle different experimental designs, postulation of a causal chain among the endogenous variables and the points of influence of the covariates is required. This has motivated the researchers at the University of Cincinnati Department of Environmental Health to be guided by a theoretical model for movement of lead from distal sources (exterior soil or dust and paint lead) to proximal sources (interior dust lead) and then finally to biologic outcomes (handwipe and blood lead). The question of whether a single structural equation model built from proximity arguments can be applied to diverse populations observed in different communities with varying lead amounts, sources, and bioavailabilities is addressed in this article. This reanalysis involved data from 1855 children less than 72 months of age enrolled in 11 studies performed over approximately 15 years. Data from children residing near former ore-processing sites were included in this reanalysis. A single model adequately fit the data from these 11 studies; however, the model needs to be flexible to include pathways that are not frequently observed. As expected, the more proximal sources of interior dust lead and handwipe lead were the most important predictors of blood lead; soil lead often had a number of indirect influences. A limited number of covariates were also isolated as usually affecting the endogenous lead variables. The blood lead levels surveyed at the ore-processing sites were comparable to and actually somewhat lower than those reported in the the Third National Health and Nutrition Examination Survey. Lessened bioavailability of the lead at certain of these sites is a probable reason for this finding.

Comparison of detection of extended-spectrum beta-lactamases by agar dilution method, E-test ESBL screen and double disk test

The extended-spectrum beta-lactamases (ESBL) are derived from TEM-or SHV-enzymes. They mediate resistance to broad-spectrum beta-lactams and can cause infectious outbreaks in hospitals. Rapid recognition and diagnosis are important for the clinician to prescribe more effective treatment. In the present study, a group of 52 probable ESBL-producing Klebsiella pneumoniae and Escherichia coli having a suspected resistant antibiogram phenotype were included. The E-test ESBL screen and the double disk test were performed for these isolates for detection of ESBL-producing strains, as compared with the conventional agar dilution method. The agreement between the E-test ESBL screen or the double disk test and the conventional agar dilution method was good and the degree of agreement were 86.5% and 92.3% respectively. The results showed that both the E-test ESBL screen and the double disk test were useful and convenient for detection of ESBLs.

Tuberculous arthritis of sacroiliac joint with abscess formation: a case report

Extrapulmonary tuberculosis at times appears to be an unusual presentation of the disease. Its incidence has not decreased, though a slow decline in pulmonary tuberculosis has been observed over the past decades around the world. The diagnosis of extrapulmonary tuberculosis is still rather difficult today. Tuberculosis of the bones and joints, which constitutes a smaller part of extrapulmonary tuberculosis, is relatively rare in documented cases and can yield variable clinical manifestations. This study describes a young male patient who developed a rare condition of tuberculous arthritis of the right sacroiliac joint, with an abscess formation over the anterior aspect of the right iliac fossa and iliopsoas muscle. The diagnosis was made by roentgenographic examinations and proved by microscopic confirmation of the presence tuberculous bacilli in drainage from the involved foci. Antituberculosis therapy was begun thereafter. Symptoms improved and the patient was regularly followed up at the Outpatient Department. It is suggested that in patients with prolonged fever and possible Mycobacterium tuberculosis infections, repeated roentgenographic and microbiological examinations are mandatory.

Silicosis among foundry workers. Implication for the need to revise the OSHA standard

To evaluate the risk of pneumoconiosis among workers in a Midwestern automotive foundry, medical records and silica sand exposure data were analyzed for 1,072 current and retired employees with at least 5 years of employment as of June 1991. Approximately half of these employees had worked at the foundry for 20 or more years. Sixty workers were found to have radiographic evidence of pneumoconiosis. Twenty-eight workers had radiographs consistent with silicosis, of which 25 were consistent with simple silicosis and three with progressive massive fibrosis. The prevalence of radiographic changes consistent with silicosis increased with: number of years worked at the foundry (6% for 20-29 years and 12% for 30 or more years); cigarette smoking (12.2% among smokers with high silica exposure vs. 4.4% among never smokers with high silica exposure); work area within the foundry (cleaning room, core room, mold area, core knockout); and quantitative silica exposure (0.3-2.7% of workers at the current Occupational Safety and Health Administration (OSHA) standard and 4.9-9.9% of workers above the OSHA standard). In addition, the odds of developing radiographic changes consistent with silicosis were increased for African Americans (odds ratio = 2.14, 95% confidence interval 0.85-5.60) in comparison with whites. (The risk was similar when silica exposure was equal, but African-American workers on average had greater exposure to silica, despite having a similar duration of work as white workers.) Another eight workers had radiographic evidence of asbestosis, and 24 had pleural plaques. These asbestos-related changes were not associated with increasing exposure to silica but rather were associated with being in the maintenance department and performing repair work. After controlling for cigarette smoking, race, and exposure to silica at another job besides the foundry, the authors found a 1.45 increased risk of developing a radiograph consistent with silicosis after 20 years of work at the current OSHA standard, and a 2.10 increased risk after 40 years of work at the current OSHA standard. On the basis of these findings, the authors recommend maintaining silica air levels no higher than the exposure level of 0.05 mg/m3 recommended by the National Institute for Occupational Safety and Health.

Formation of morphine from codeine in Chinese subjects of different CYP2D6 genotypes

Codeine and morphine pharmacokinetics among different CYP2D6 genotypes was compared in this study. Polymerase chain reaction tests were used to determine CYP2D6 genotypes in leukocyte deoxyribonucleic acid in 32 unrelated volunteers. Based on the genotypes, subjects were categorized into three groups: homozygous C/C188 (n = 8), heterozygous C/T188 (n = 12), and homozygous T/T188 (n = 12). Each subject was given a single oral dose of 30 mg codeine phosphate tablet after overnight fasting. Plasma concentration of codeine and 24-hour urinary morphine recovery were measured with HPLC. All three genotypes of subjects showed almost identical time profiles of plasma codeine. Urinary morphine glucuronide was hydrolyzed with beta-glucuronidase. The total recovered amount of morphine and glucuronides was 4349 +/- 646, 2564 +/- 242, and 1127 +/- 164 nmol (mean +/- SEM), respectively, for C/C188, C/T188, and T/T188 subjects (p < 0.05). The significant lower amount of urinary morphine but identical codeine plasma concentration suggested a lower partial clearance of the formation of morphine from codeine in T/T188 subjects. The results suggest a future study to assess the analgesic effect of codeine in different genotypes of CYP2D6 extensive metabolizers.

Clinical correlates of quantitative acoustic analysis in ataxic dysarthria

The speech of 15 Taiwanese patients with cerebellar dysfunction and ataxic dysarthria was investigated utilizing techniques of acoustic analysis and instrumental measurement. Semiquantitative assessment of cerebellar function (SQACF) was also performed. The results of the acoustic analysis of the cerebellar speech were then correlated with the findings in the SQACF. The overlapping of voice onset time highly correlates with truncal ataxia as well as eye movement abnormality and eye-hand coordination. The prolongation of vowel duration also correlates significantly with tandem walking, dysdiadochokinesia and eye movement abnormality. The correlation of the speech function with other cerebellar motor functions provides further insight into the functional anatomy for cerebellar speech motor control. This study concludes that the midline structures-vermis and fastigial nucleus-seem to be the primary focus for the coordination of motor speech in the cerebellum.

Use of restriction endonuclease analysis of plasmids and pulsed-field gel electrophoresis to investigate outbreaks of methicillin-resistant Staphylococcus aureus infection

We used restriction endonuclease analysis of plasmids (REAP) and pulsed-field gel electrophoresis (PFGE) to investigate clusterings of methicillin-resistant Staphylococcus aureus (MRSA) infections in our orthopedic unit, neurosurgery unit, intensive care unit, and burn unit. Fourteen different strain types were identified by REAP and 10 different strain types were identified by PFGE among 25 MRSA isolates collected during these incidents of infection. Though neither technique was clearly superior to the other for typing MRSA isolates, REAP is recommended as a relatively simple and reproducible technique for the preliminary investigation of MRSA infection outbreaks in clinical settings.

Epidemiological typing of Flavimonas oryzihabitans by PCR and pulsed-field gel electrophoresis

Flavimonas oryzihabitans has emerged as a potential nosocomial pathogen in recent years. The typing method for characterization of this species has never been reported before. Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based PCR were used to generate DNA fingerprints for 14F. oryzihabitans isolates obtained from eight episodes of nosocomial infections during a 2-year period. Both techniques successfully classified these clinical isolates into eight distinct genotypes, thus indicating that all of these episodes of infections were independent. In contrast, repeated isolates from the same patient were assigned to identical genotypes. The reproducibility of both techniques was good. Therefore, we conclude that both PFGE and ERIC-PCR have comparable reproducible and discriminatory powers for the typing of F. oryzihabitans and may be useful for clarifying the epidemiology of this species; however, ERIC-PCR has the advantages of both speed and simplicity.

Comparison of different PCR approaches for characterization of Burkholderia (Pseudomonas) cepacia isolates

In this study, we evaluated three PCR methods for epidemiological typing of Burkholderia (Pseudomonas) cepacia--PCR-ribotyping, arbitrarily primed PCR (AP-PCR) and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR)--and compared them with pulsed-field gel electrophoresis. The analysis was performed with 31 isolates of B. cepacia, comprising 23 epidemiologically unrelated isolates and 8 isolates collected from the same patient during two episodes of bacteremia. Pulsed-field gel electrophoresis, ERIC-PCR, and AP-PCR identified 23 distinct types among the 23 unrelated isolates, while PCR-ribotyping only identified 12 strain types, even after AluI digestion of the amplification products. Among the eight isolates collected from the same patient, all typing techniques revealed two clones of strains. The day-to-day reproducibilities of PCR-ribotyping and ERIC-PCR were good, while greater day-to-day variations were noted in the fingerprints obtained by AP-PCR. We conclude that all three PCR techniques are useful for rapid epidemiological typing of B. cepacia, but ERIC-PCR seems to be more reproducible and discriminative.

DNA fingerprinting of Pseudomonas aeruginosa serotype O11 by enterobacterial repetitive intergenic consensus-polymerase chain reaction and pulsed-field gel electrophoresis

We report the use of pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based polymerase chain reaction (PCR) to characterize clinical isolates of Pseudomonas aeruginosa serotype O11 collected from an incident of hospital-acquired infection. Both typing techniques differentiated 20 different strain types among seven epidemiologically related isolates and 22 epidemiologically unrelated isolates. There was complete concordance between these two techniques. Our results indicate that the ERIC-based PCR technique represents a rapid and simple means for typing P. aeruginosa serotype O11 with a level of discrimination equivalent to that of PFGE.

Comparison of susceptibility to extended-spectrum beta-lactam antibiotics and ciprofloxacin among gram-negative bacilli isolated from intensive care units

The in vitro activities of extended-spectrum beta-lactam antibiotics (including piperacillin, cefotaxime, ceftriaxone, ceftazidime, cefepime, imipenem, and meropenems) were assessed and compared with the activity of ciprofloxacin against 366 clinical Gram-negative bacilli isolates from the intensive care units of Taichung Veterans General Hospital. The most prevalent species isolated were Pseudomonas aeruginosa and Acinetobacter baumannii. The activities of ceftazidime, cefepime, imipenem, and meropenem against these isolates were comparable to that of ciprofloxacin. Meropenem was found to be the most potent extended-spectrum beta-lactam antibiotic tested and the MIC50s and MIC90s for most of these multiresistant strains were lower than those of imipenem, ceftazidime, and cefepime, except for Stenotrophomonas maltophilia. The extended-spectrum beta-lactam antibiotics that were still active against S. maltophilia were piperacillin and ceftazidime. More than 50% of Enterobacter spp. were resistant to third-generation cephalosporins and piperacillin, but they remained susceptible to carbapenems and cefepime.

Analysis of clonal relationships among isolates of Shigella sonnei by different molecular typing methods

Shigella sonnei is a major cause of diarrheal disease in developed as well as in developing countries. Epidemiologic studies of this organism have been limited by the lack of a simple and effective method for comparing strains. In this study, we have compared different molecular typing methods, i.e., plasmid profile analysis, restriction endonuclease analysis of plasmids, rRNA gene restriction analysis (ribotyping), pulsed-field gel electrophoresis (PFGE), and enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR) for typing 20 clinical isolates of S. sonnei collected from six incidents of infection. PFGE and ERIC-PCR fingerprintings had the highest discriminatory power for discrimination of epidemiologically related isolates from epidemiologically unrelated strains of S. sonnei, and both gave seven distinct strain types among these isolates and the type strain of the species. Plasmid study and ribotyping produced only six and typing techniques demonstrated two distinct patterns, respectively, among these strains. All of these molecular an identical fingerprint for eight temporally related sporadic isolates. It is possible that these temporally related isolates belonged to a single bacterial clone and circulated obscurely through the community. Our results indicate that the ERIC-PCR technique represents a rapid and simple means for typing S. sonnei with a level of discrimination equivalent to that of PFGE but greater than those of plasmid profile analysis, restriction endonuclease analysis of plasmids, and ribotyping.

Maternal and fetal cardiovascular responses to methamphetamine in the pregnant sheep

OBJECTIVES

Our purpose was to evaluate the maternal and fetal cardiovascular effects of maternally administered methamphetamine and to determine the extent of placental transfer.

STUDY DESIGN

Seven near-term pregnant sheep were surgically instrumented to measure maternal and fetal blood pressure and heart rate, cardiac output, uterine flow, and umbilical flow. A single dose of methamphetamine 1 mg/kg was administered as a bolus to study maternal and fetal cardiovascular responses and placental transfer.

RESULTS

Maternal administration of methamphetamine caused increases in maternal blood pressure, heart rate, cardiac output, and systemic vascular resistance and decreased uterine blood flow. Peak maternal changes occurred within 10 minutes after methamphetamine administration and were near baseline by 180 minutes. Fetal blood pressure increased and returned slowly to baseline by 2 hours. After an initial decrease fetal heart rate increased above baseline values over the next 2 hours. Umbilical blood flow also decreased initially and then increased slightly. Fetal pH and PO2 tended to decrease. Maternal and fetal methamphetamine levels reached a maximum of 2.9 and 1.9 micrograms/ml, respectively. Rapid and significant placental transfer, delayed excretion into the amniotic fluid, and slow elimination from the maternal and fetal circulation were demonstrated.

CONCLUSION

Methamphetamine readily crosses the ovine placenta, producing significant and long-lasting maternal and fetal cardiovascular effects, which may have long-term consequences, especially if administered repetitively.

Frontal cephalometric study of dentofacial morphology in children with bilateral clefts of lip, alveolus and palate

The transverse dentofacial morphology of 36 children with bilateral cleft lip, alveolus and palate was studied by means of a frontal proportional cephalometric analysis at the ages of three, eight and twelve years. Comparison of the variables of the cleft group was made with the normal dimensions as obtained from the Bolton cephalometric templates. The results indicated that the BCLP group presented characteristics and significant differences from the normal in the dimensions of the nasal septum width and the mandibular intergonial width as they are both related to the interorbital width, the maxillary intermolar width as it is related to the mandibular intermolar width and the maxillary width as it is related to the mandibular intergonial width at all three ages. The maxillary base and intermolar widths, although significantly different at the ages of three and eight years, showed no significant deviation from normality at the age of twelve years. Following orthodontic treatment between the ages of seven to twelve years, the maxillary intermolar width of the treated subgroup was significantly larger than in the untreated subjects.

An electron microscopical study of epiplexus and supraependymal cells in the prenatal rat brain following a maternal injection of 6-aminonicotinamide

Epiplexus and supraependymal cells in the lateral ventricles of both normal and experimental prenatal rats were studied with the scanning and transmission electron microscopes. In normal rats, the epiplexus cells, which were predominantly spindle shaped, displayed long filopodial processes inserted into the palisade of microvilli of the choroid epithelium; their cell bodies appeared relatively smooth with occasional blebs. In experimental animals in which the mother was given an injection of 6-aminonicotinamide (6-AN), the cell bodies of the epiplexus cells became extremely ruffled or blebbed. They were seen to be actively involved in the phagocytosis of leaked erythrocytes. The behaviour of supraependymal cells was rather similar. When stimulated by a 6-AN injection, the cells showed large prominent blebs and they too were engaged in phagocytic activity. It was concluded from this study that intraventricular macrophages bearing numerous filopodia are the less active cells whereas those bearing shorter processes, in particular, blebs or ruffles, represent the active form.

A scanning and transmission electron microscopic study of amoeboid microglial cells in the prenatal rat brain following a maternal injection of 6-aminonicotinamide

The amoeboid microglial cells in the cavum septum pellucidum of prenatal rats aged 22 days post-conception were studied by scanning and transmission electron microscopy. The cells in normal rats had numerous filopodia, while those in experimental animals whose mothers had received an intraperitoneal injection of 6-aminonicotinamide (6-AN) on the 14th day of gestation, showed an abundance of blebs or possessed smoother contours. Extravasated red blood cells and nerve fibres were seen to be engulfed by the amoeboid cells of the blebbed as well as the smooth type. Transmission electron microscopy confirmed the phagocytosis of red blood cells and nerve fibres in the cytoplasm of the amoeboid cells. It is postulated that the amoeboid microglial cells responded to 6-AN by increasing their phagocytic activity and by changing their surface morphology. The factors leading to such alterations are discussed.

Isolation and culture of amoeboid microglial cells from the corpus callosum and cavum septum pellucidum in postnatal rats

In phase contrast and scanning electron microscopy, diverse structural forms of cells tenaciously adherent to glass coverslips were observed in the culture of the corpus callosum and cavum septum pellucidum from postnatal rats. In day 1 culture, many of the cultured cells were round, with well spread peripheral cytoplasm which appeared homogeneous. Cell organelles aggregated mainly around the reniform or round nucleus. Some cells showed spinous projections. In day 3-5 culture, the cells became irregular, sending out long branching pseudopodial processes; often they displayed a vacuolated cytoplasm. The cultured cells were highly phagocytic, as shown by their uptake of colloidal carbon particles and latex beads, in light microscopy and scanning electron microscopy, respectively. Cytochemical studies have shown that the cells were peroxidase-negative but were strongly positive for non-specific esterase, similar to the amoeboid microglial cells in the postnatal corpus callosum. On the basis of their structural features, both in phase contrast and scanning electron microscopy, experimental as well as cytochemical properties, it is concluded that the cells in the present culture are in fact amoeboid microglial cells which are active macrophages in the developing corpus callosum.

Light and electron microscopic and cytochemical identification of amoeboid microglial cells in the brain of prenatal rats

The development of amoeboid microglial cells was studied in embryonic rats extending from the twelfth day post-conception (E12) through late gestation. With the silver stain, amoeboid microglial cells in the supraventricular corpus callosum appeared at around E17 and their number increased dramatically to more than 20 times just before birth. Most of the cells were round with projecting fine cytoplasmic processes. The silver-stained preparations also showed that the supraventricular region was vascularised around E13. With the same method, it has been shown that islands, with an admixture of erythroblasts and amoeboid microglial cells, were a common feature in the embryonic brains. Electron microscopic study confirmed the existence of amoeboid microglial cells in E15-E18 rats. Among these, there were small dense cells with little cytoplasm containing predominantly free polyribosomes. At the cell surface, there were microvilli. Other cells were large and appeared to be actively involved in phagocytosing degenerating cells. Transitional forms were present. With growth, the amoeboid microglial cells further differentiated and their cytoplasm accumulated abundant lysosomal granules. Cytochemical study showed that amoeboid microglial cells in the embryonic brains were stained for non-specific esterase. The observations in the present study suggest that amoeboid microglial cells are formed following vascularisation of the brain tissues. The invading mesenchymal cells with haemopoietic potentiality not only develop into endothelial cells but also into extravascular small amoeboid microglial cells which have the features of monocytes, and which, with growth, will transform into the large macrophagic cells.

Scanning electron microscopy of amoeboid microglial cells in the transient cavum septum pellucidum in pre- and postnatal rats

The cavum septum pellucidum in rats of different ages was studied by light and scanning electron microscopy. A reconstruction from serial paraffin sections showed that the cavum was a pyramidal shaped closed cavity which was bounded above by the corpus callosum and inferolaterally by the lateral septal nuclei. The first sign of the cavum formation was noted in the 20 days post conception rat where there was a loosening up of the neuropil beneath the corpus callosum deep to the longitudinal fissure. A variable number of amoeboid microglial cells, characterised by their abundant eosinophilic cytoplasm, was seen among the smaller immature cells in the wide interstitial spaces. A definitive cavity was formed in the 21 days post conception rat and it continued to grow until the fifth postnatal day when it gradually diminished in size to become slit-like by the fifteenth postnatal day. The scanning electron microscope showed that the wall of the cavum was composed of a feltwork of glial and nerve fibres. Two types of cells were present in the cavum: cells identified as glioblasts, and amoeboid microglial cells. The glioblasts were were characterised by having a smooth cell body with radiating long processes. The amoeboid microglial cells showed diverse forms of surface protrusions: blebs, filopodia and membrane ruffles similar to other tissue macrophages. They were either adherent to the walls of the cavum, clustered around the blood vessel which traversed the cavum, or floating freely in the lumen. It was suggested that the amoeboid microglial cells were probably derived from extravasated blood monocytes in response to the physical damage resulting from the formation of the cavum septum pellucidum in the developing brain.

Fine structural changes in the hamster pineal gland after blinding and superior cervical ganglionectomy

Pineal glands of male hamsters 8 weeks after removal of both eyes or both superior cervical ganglia and those of untreated animals were studied by electron microscopy. In the blinded hamsters the reproductive organs were remarkably involuted, whereas the pinealocytes enlarged and were characterized by a tremendous hypertrophy of the smooth-surfaced endoplasmic reticulum, in the mesh of which some dense cored vesicles were distributed. In constrast the pinealocytes of ganglionectomized hamsters atrophied and were noted by a large number of lysosomes and sparsity of the agranular reticulum, the testes being significantly larger than the controls. The findings were interpreted to be compatible with the view that the pineal capability of producing antigonadal substance is augmented by blinding and is suppressed by cervical ganglionectomy due to the impairment of normal functioning of the pineal by denervation. It is assumed that the degree of development of the smooth endoplasmic reticulum in the pinealocyte is parallel to, and reflects that of the pineal activity. Probably the membranous organelle is involved in the elaboration of the pineal antigonadal substance.