Ultrasound in urological emergency: results of self audit and implications for training

The efficacy of ultrasound examination by the trainee urologists in the management of urological emergencies admitted in a district general hospital was studied. Fifty patients (100 kidney units) had renal ultrasound performed by urological trainees on acute admission. The results were compared with subsequent definitive radiological investigations. On analysis of 100 renal units there were 7 discordant results, 2 false negatives and 5 false positives achieving 97% specificity (95% confidence interval 93% to 100%) and 84% sensitivity (95% confidence interval 71% to 97%). Adopting 50-patient analysis there was 89% specificity (95% confidence interval 74% to 100%) and 84% sensitivity (95% confidence interval 71% to 97%). These intervals indicate the levels of success to be expected in future studies. The study shows that urological trainees can use ultrasound with high levels of accuracy improving patient management.

Time course of radiation-induced apoptosis in the adult rat spinal cord

Radiation-induced apoptosis has been reported in thymic, lymphoid, haematopoietic cells and intestinal epithelium but is infrequently documented in other adult mammalian cell types. In this study, we examined the time course of radiation-induced apoptosis in the adult cervical rat spinal cord following a single dose of 8 or 22 Gy. Apoptosis was assessed by morphological criteria under light and electron microscopy, and immunohistochemically in-situ using Apoptag to detect 3' -OH ends of DNA fragments. Little evidence of apoptosis (0.3 +/- 0.1 apoptotic nuclei per spinal cord section) was observed in control un-irradiated spinal cord. A significant increase in the number of apoptotic cells per spinal cord section was seen at 4 h after 8 (13.6 +/- 1.3) or 22 Gy (22.0 +/- 2.7). The number of apoptotic nuclei reached a peak at 8 h (44.7 +/- 3.7 after 8 Gy, 49.5 +/- 4.3 after 22 Gy), and returned to the baseline level by 24 h (2.4 +/- 0.7 after 8 Gy, 3.3 +/- 0.7 after 22 Gy). A dose of 22 Gy induced significantly more apoptoses than 8 Gy at 4, 6, 10 and 12 h (P < or = 0.033), but not at 8 h. More apoptotic nuclei were observed in white matter (64-92%) than gray matter (8-36%). All the apoptotic cells were observed in glial cells, and there was no evidence of radiation-induced apoptosis in the vascular endothelial cells or neurons. The morphological features of the apoptotic cells under electron microscopy and the absence of GFAP staining suggested that they were oligodendrocytes. We conclude that radiation induces apoptosis in the adult rat spinal cord, and that the development of apoptosis follows a specific time course.

An experimental design approach to retrospective exposure assessment

There are several methods currently in use for retrospective estimation of quantitative exposure levels in occupational and environmental epidemiologic studies. The most popular is a job-exposure matrix approach using a combination of existing data and professional judgment. Another method is the use of statistical models based on available exposure data. The authors present an alternative approach using an experimental design in which several factors thought to affect exposure levels are identified and set at specific levels in a cross-classified design. This approach was used to estimate historical exposures to formaldehyde in a mortality study of embalmers. Exposures were estimated as a function of solution concentration, air exchange rate, and autopsied versus intact body. There were 12 combinations involving these 3 factors and a total of 25 embalming procedures (approximately 2 replicates of each combination) performed at a college of mortuary science. In addition to these design factors several covariates such as temperature, humidity, and the occurrence of spills were considered in an analysis of covariance statistical model. The results of the model prediction were validated against published measurements, and field samples were taken in several funeral homes. The overall accuracy of the model predictions was comparable to the variation found in replicate measurements of identical embalming procedures.

Efficacy of fetal echocardiography and yield by risk category

OBJECTIVE

To determine the efficacy and yield of tertiary center fetal echocardiography for different high-risk groups.

METHODS

Between January 1, 1982, and January 1, 1994, scans for anomalies were performed on 3246 women at increased risk for congenital heart disease in their offspring. Gestational age was 16-25 weeks in 83%. Maternal and gestational age as well as prenatal and postnatal diagnosis were recorded, and follow-up was sought for all pregnancies. By comparing prenatal and postnatal diagnoses, sensitivity, specificity, and predictive values were estimated. Multiple logistic regression was applied to establish the relative yield within the high-risk group.

RESULTS

Follow-up was available in 3223 cases (99%). In a separate validation study of 777 women for whom a second set of follow-up data was requested, no additional anomalies were revealed. In total, 20 of 47 cases of cardiac malformations were detected (sensitivity 43%). When taking into account cases that remained undetected because of unfavorable scanning conditions (ie, minute size of the anomaly, awkward fetal position, or severe maternal obesity), the sensitivity for congenital heart disease rose to 51%. Specificity and predictive values were high (above 95%). The relative yield across the high-risk group appeared to be high for parental congenital heart disease and maternal diabetes mellitus, whereas a previous infant or other relatives affected, maternal anti-epileptic drug use, maternal drug abuse, and other reasons for referral each had an estimated yield approximately equal to the prevalence of congenital heart disease in the general population (0.8%).

CONCLUSION

Fetal echocardiography for known increased risk appears to be moderately effective. Clear differences in yield are present across currently accepted risk categories.

The efficacy of flecainide versus digoxin in the management of fetal supraventricular tachycardia

Fetal supraventricular tachycardia (SVT) can be successfully treated transplacentally, but in cases where fetal hydrops develops there is considerable morbidity and mortality. The present study was carried out to establish whether the introduction of flecainide altered obstetric management and fetal outcome. A retrospective analysis took place of 51 singleton pregnancies which were referred to the division of prenatal diagnosis because of fetal tachycardia between 1982 and 1993. SVT was documented in 50 out of 51 fetuses, one of which displayed a combination of extensive rhabdomyomas and severe hydrops and died shortly after referral. In the other fetus ventricular tachycardia was diagnosed. Of the remaining 49 fetuses, 14 did not receive any prenatal treatment, but nine needed postnatal treatment. Transplacental treatment of SVT took place in 35 fetuses, of which 22 presented without hydrops and 13 with hydrops. These subsets differed significantly with respect to restoration of normal sinus rhythm (73% vs. 30%; p < 0.001) and mortality (0% vs. 46%; p < 0.001). Digoxin was effective in restoring sinus rhythm in 55 per cent of the non-hydropic fetuses but in only eight per cent of the hydropic fetuses. Flecainide was effective in restoring sinus rhythm in all non-hydropic fetuses where digoxin treatment failed, and in 43 per cent of hydropic fetuses. Administration of flecainide resulted in a significantly reduced mortality (p < 0.001) compared with digoxin treatment. No adverse effects were seen. Postnatal anti-arrhythmic treatment was necessary in 23 infants. Treatment could be withdrawn within one year in all cases but one.

Blood-spinal cord barrier function and morphometry after single doses of x-rays in rat spinal cord

PURPOSE

The effects of irradiation on blood-spinal cord barrier (BSCB) function and ultrastructure were evaluated using a rat spinal cord model.

METHODS AND MATERIALS

Rats received a single dose of 25 Gy to the cervical spinal cord (C2-T2). At various times following irradiation and before the onset of paralysis, BSCB function was assessed using horseradish peroxidase (HRP) as a vascular tracer, and barrier-related structural changes in the capillaries were evaluated using morphometric techniques.

RESULTS

Focal extravasation of HRP was seen at 93 days after irradiation, and extensive extravasation was apparent by 114 days in white matter, but not in gray matter. At 93 days, pathologic changes apparent by light microscopy were very minor in the white matter of the irradiated segment. By 107 days, myelin beading, Wallerian degeneration, edema, and histiocytes were apparent in white matter, and these features became increasingly prominent over the following weeks. No noteworthy changes were seen in gray matter at these times. Electron microscopic examination showed that, during the first 93 days following irradiation, more than half of the endothelial cells in white matter had disappeared (p < 0.05). In terms of the putative vascular pores, no abnormalities in endothelial junctions (the presumed small pore) were found, but there was an increase in the density of endothelial vesicles (a putative form of the large pore) in irradiated white matter (p < 0.001), but not in gray matter. Pericytes, thought to act as a second line of defence in the blood-brain barrier, increased in size but not in number in the irradiated white matter of the spinal cord.

CONCLUSION

We suggest that radiation damage to endothelial cells, which form the BSCB prior to the onset of neurological deficit, may play an important role in the pathogenesis of white matter necrosis.

Acute bacterial prostatitis with osteomyelitis

This short case presentation concerns the simultaneous occurrence of acute bacterial prostatitis and osteomyelitis due to staphylococcal bacteraemia hitherto unrecorded in the literature.

Occupational exposures and female breast cancer mortality in the United States

Mortality records from 24 states, gathered from 1984 to 1989 and coded for occupation and industry, were used to develop leads to workplace exposures as possible breast cancer risk factors. A case-control approach was used, with separate analyses for blacks and whites. After excluding homemakers, 33,509 cases and 117,794 controls remained. A job exposure matrix was used to estimate the probability and level of 31 workplace exposures. After adjusting for socioeconomic status, suggestive associations for probability and level of exposure were found for styrene, several organic solvents (methylene chloride, carbon tetrachloride, formaldehyde), and several metals/metal oxides and acid mists. Because of the methodologic limitations of this study, its primary value is in suggesting hypotheses for further evaluation. The findings for styrene, selected solvents, and metals and metal-related exposures deserve additional study.

An International Effort to Improve Methods of Data Collection and Exposure Assessment for Community-based Case-Control Studies of Occupational Disease

The authors recommend that an international effort be made to develop standardized questionnaires for collecting occupational exposure information and to develop standard assessment procedures for evaluating occupational exposures in community-based case-control studies. Such standardization should improve the quality and credibility of findings from this type of study, as well as the comparability of results across studies.

Dose-related effects of alcohol on dynamic posturography and oculomotor measures

Four healthy male volunteers < 30 years of age participated in a blinded study of placebo versus low (0.45 g/kg lean body weight = LBW), medium (0.80 g/kg LBW) and high (1.05 g/kg LBW) dose ethanol ingestion to investigate its effect upon gaze and posture control. Serial electronystagmography and computerized platform posturography were performed at different points along each subject's blood alcohol concentration (BAC) curve as measured by breath analysis. Smooth pursuit and positional testing revealed subtle abnormalities at sub-intoxicating BACs. In addition, instability on posturography was evident on the Sensory Organization Test with no statistically significant influence observed on muscle latency testing as determined by sway analysis. We conclude that even low ethanol BAC levels produce widespread gaze and posture control effects which can be easily documented.

Occupational case-control studies: I. Collecting information on work histories and work-related exposures

The strength and credibility of evidence from occupational case-control studies largely depend on the validity and precision with which the work history is reported and the exposure is assessed. We discuss the two steps which ultimately lead to an exposure decision. The first step involves the exchange between the respondent and an interviewer. The latter is usually naïve to occupations and workplace exposures and, as such, is limited to asking generic and open-ended questions about the workplace. Often, this type of information is too nonspecific to assess exposure. In the second step, an expert reviews the information reported on each occupation and decides on exposure status without contacting either the interviewer or respondent. Exposure assessment is not, therefore, integrated with data collection and, in fact, is usually not initiated until after all the interviews are completed. As such, the exposure expert does not have an opportunity to resolve questions before making the exposure decision. To improve the quality and specificity of data collected, we have developed over 40 sets of close-ended questions (branch questions) which are specific to defined occupations. These branch questions, incorporated into a computer-assisted telephone interview, are asked if selected occupations or their synonyms are reported. Second, to link the data collection process with the assessment process, we have developed a procedure called SCORE (Subject Corrected Occupational Report) which provides the industrial hygienist with a cost efficient method to ask questions directly of respondents. Shortly after each interview is completed, a computerized version of the work history is reviewed by the industrial hygienist who develops questions when more information is needed. Subsequently, respondents are mailed a form listing their reported work history along with the questions. After two mailings, 73% of participants in a pilot study returned the SCORE form.

Occupational case-control studies: II. Recommendations for exposure assessment

Obtaining valid and reliable quantitative exposure estimates is a significant challenge in community-based case-control studies in part, because industrial hygiene monitoring data are usually not available and detailed information on the job and work environment is usually not systematically obtained or assessed. To improve the quality and credibility of disease risk information obtained from occupational case-control studies, we recommend that standardized exposure assessment methods be used to derive quantitative exposure estimates. We identify sources of variation inherent to the assessment process, including: the quality of the information reported on the job, industry, activities, and materials; the industrial hygienist's familiarity with the reported job/industry; the probability that the job/industry was exposed, which depends on plant preferences for particular substances, on process technology, and on customer specifications; and variability in workplace characteristics. To improve the reliability of estimating job-related exposures both within and between studies, we recommend that the epidemiologic analyses be conducted with and without data rated to be of poor quality; that contact be made with experts when the study industrial hygienist is unfamiliar with the manufacturing process in question; that existing data bases be used to estimate the probability of exposure; that a data base be developed that describes manufacturing processes; and that explicit criteria based on industrial hygiene principles be used to evaluate workplace characteristics. In addition, a procedure is described for deriving quantitative exposure estimates by using a reference scale of frequently monitored jobs with their associated mean exposure levels. Areas of research are identified to improve exposure assessment in community-based case-control studies.

Occupational exposure to chlorinated aliphatic hydrocarbons and risk of astrocytic brain cancer

Chlorinated aliphatic hydrocarbons (CAHs) were evaluated as potential risk factors for astrocytic brain tumors. Job-exposure matrices for six individual CAHs and for the general class of organic solvents were applied to data from a case-control study of brain cancer among white men. The matrices indicated whether the CAHs were likely to have been used in each industry and occupation by decade (1920-1980), and provided estimates of probability and intensity of exposure for "exposed" industries and occupations. Cumulative exposure indices were calculated for each subject. Associations of astrocytic brain cancer were observed with likely exposure to carbon tetrachloride, methylene chloride, tetrachloroethylene, and trichloroethylene, but were strongest for methylene chloride. Exposure to chloroform or methyl chloroform showed little indication of an association with brain cancer. Risk of astrocytic brain tumors increased with probability and average intensity of exposure, and with duration of employment in jobs considered exposed to methylene chloride, but not with a cumulative exposure score. These trends could not be explained by exposures to the other solvents.

Occupational exposure to chlorinated aliphatic hydrocarbons: job exposure matrix

A job exposure matrix combining features to increase the accuracy of exposure assessment was developed to evaluate cancer risks from workplace exposures to six chlorinated aliphatic hydrocarbons (CAHs). A detailed description of the matrix is provided to satisfy the need for more in-depth discussion of exposure assessment methods than is typical in today's epidemiologic literature. The matrix assigns semiquantitative estimates of the probability and intensity of exposure to each four-digit Standard Industrial Classification (SIC) and Standard Occupational Classification (SOC) code potentially associated with exposure to each CAH. The matrix also accounts for the changing patterns of use of the CAHs by decade from the 1920s to the 1980s. An algorithm combines these parameters to assign each study subject a unique lifetime probability of exposure and an estimated score of cumulative exposure for each CAH. These assignments can then become the subjects of analyses. The ability of the matrix to reduce the number of false positive exposure assessments is discussed and illustrated. A companion paper describes the detailed epidemiologic findings of this application of the matrix.

Women in the formaldehyde industry: their exposures and their jobs

Several studies have examined disease risks for women separately from risks for men, but few have examined exposure differences. This report used data from an epidemiological study of formaldehyde workers to compare formaldehyde exposures between men and women. Exposures were estimated from historical monitoring results, walk-through workplace surveys, interviews with long-term workers, and reviews of historical records. The mean of the exposures in the first job, the last job, and the highest exposed job were calculated by gender. Differences were found when all subjects were included in the analysis (men having higher exposures, on average, than women), but when nonexposed subjects were removed (40% of women, 6% of men), differences were minor. There was a substantial difference in the estimated peak exposure between men and women that decreased, but remained, when only exposed subjects were included. Evaluation of exposures in 1940 to 1945, 1965, and 1979 found that women had a higher average exposure than men in 1940 to 1945, but this pattern was reversed in 1965. By 1979, the average difference between the two genders had disappeared. A comparison of cumulative exposure found that exposed women had half the total exposure of exposed men. More men than women were exposed to other chemicals. Women tended to predominate in clerical, laboratory, assembly, finishing, inspecting, packing, and shipping jobs.

Growth characteristics of early passage cell lines compared with established TCC bladder lines

The growth patterns of established cell lines from bladder transitional cell carcinoma (TCC) were compared with early passage cell lines. The growth of established cell line 5637 was uninhibited in both serum free (basal) and serum containing media. The early passage line (DR) grew only in serum containing medium. This confirms the unreliability of results from biological studies on established (continuous) cell lines.

Clinical significance of maternal anti-Ro/SS-A antibodies in children with isolated heart block

OBJECTIVES

We studied 30 consecutive children with isolated heart block to assess the clinical impact of the presence of maternal anti-Ro/SS-A antibodies for isolated heart block.

BACKGROUND

Isolated heart block in children, often associated with maternal autoimmune disease leading to anti-Ro/SS-A auto-antibody production, is an infrequent but potentially lethal disorder.

METHODS

Thirty children with isolated heart block were studied with respect to medical history and electrocardiographic (ECG) analysis. The presence of anti-Ro/SS-A antibodies was determined in the maternal serum. We also examined the ECGs of all brothers and sisters of the patients for conduction abnormalities.

RESULTS

Twenty-one of the 30 children had an anti-Ro/SS-A-positive mother (group A); the other 9 children had an anti-Ro/SS-A-negative mother (group B). Comparison of the clinical data from both mothers and children revealed that these two groups differed significantly with respect to the following: Prenatal diagnosis and obstetric complications occurred more often in group A, whereas progression to complete block, QRS width > 0.08 s, premature ventricular contractions and ventricular standstills > 4.5 s occurred more often in group B. In addition, mothers of children in group A reported more spontaneous abortions. All siblings of children in groups A and B had normal ECGs, excluding a subclinical form of heart block.

CONCLUSIONS

Two types of heart block can be recognized: Congenital heart block is associated with maternal anti-Ro/SS-A antibodies and numerous obstetric and neonatal complications. It is diagnosed prenatally or at birth and is usually complete at onset and probably has a substantial recurrence risk. Heart block that is acquired later in life is not associated with maternal autoimmunity and has no risk for recurrence. It often presents as a partial block but progresses to complete block in time.

Quantitation of blood-brain barrier ultrastructure

This paper describes a quantitative approach to evaluating the ultrastructural features of brain capillaries that relate to the low non-specific permeability of the blood-brain barrier (BBB). Critical features in this approach include examination of large numbers of tissue samples and consistent, objective means of measuring features of interest. Junctional clefts, i.e., continuous channels between tight junctional regions correlate well with the know vascular permeability, being low in normal adult blood-brain barrier, high in fetal brain, and high in tumours, both human and rat. Endothelial vesicles do not always correlate with vascular permeability. They have a low density in normal adult BBB, but are also low in fetal BBB and low in some intracranial tumour vessels. However, they have a high density in muscle capillaries, and others have shown that they increase in BBB vessels damaged by hypertension. Fenestrations are consistently high in leaky vessels, but not all leaky vessels have fenestrations. The density of mitochondria in endothelial cells is high in BBB vessels of some species but not in others. Glut-1, the glucose transporter of the BBB is asymmetrically distributed between the luminal and abluminal membranes of BBB capillaries, being almost four times as numerous on the abluminal face. A large intracellular pool of glucose transporter may provide a means for rapid upregulation of the surface transporters.

Radiographer-performed abdominal and pelvic ultrasound: its value in a urology out-patient clinic

OBJECTIVE

To assess the efficacy of radiographer-performed ultrasound examination as a routine investigative procedure in a urological out-patient clinic.

PATIENTS AND METHODS

A total of 151 patients attending a District General Hospital Urological Out-patient Department underwent an ultrasound examination in the clinic.

RESULTS

Diagnosis by ultrasound was achieved in 93% of patients. The remaining patients underwent further investigations. Two (1%) patients with normal scans had small bladder tumours. Subsequent intravenous urography in these individuals showed normal upper tracts.

CONCLUSION

Abdominal and pelvic ultrasound examination performed in the urological out-patient clinic on unprepared patients was the only investigation necessary for evaluation of common problems such as non-specific urinary symptoms, recurrent urinary tract infections and bladder outlet obstruction.