Association between night work and prostate cancer: a systematic review and meta-analysis

OBJECTIVE

The aim was to conduct a systematic review and meta-analysis to study the association between night work and the development of prostate cancer.

METHODS

A systematic literature search was conducted in CINAHL, Embase, MEDLINE, and Web of Science. Studies were included based on a PECOS; the population included men in/above the working age, exposure defined as night work, outcome defined as prostate cancer, and study design restricted to cohort studies. The exclusion of articles, risk-of-bias assessment, and data extraction were performed by two reviewers. A meta-analysis was conducted using a random-effects model, including a sensitivity analysis stratified based on the risk-of-bias assessment. We evaluated publication bias using a funnel plot and Egger´s test, and the level of evidence was assessed using GRADE.

RESULTS

A total of 528 articles were identified, and eight cohort studies were included. Three studies had a moderate risk of bias, while five studies had a high risk of bias. The meta-analysis showed a pooled hazard ratio (HR) of 1.0 (95% CI 0.6-1.7). In the sensitivity analysis, moderate vs. high risk-of-bias studies showed a pooled HR of 1.2 (95% CI 0.3-4.1) and 0.9 (95% CI 0.6-1.3), respectively. Based on GRADE, the level of evidence was rated low.

CONCLUSION

We found no association between night work and the development of prostate cancer. The evidence was assessed as limited and inconsistent. Future studies encompassing consistent definitions of night work, including objective exposure data, are highly warranted.

Targeted gene sequencing and whole-exome sequencing in autopsied fetuses with prenatally diagnosed kidney anomalies

Identification of fetal kidney anomalies invites questions about underlying causes and recurrence risk in future pregnancies. We therefore investigated the diagnostic yield of next-generation sequencing in fetuses with bilateral kidney anomalies and the correlation between disrupted genes and fetal phenotypes. Fetuses with bilateral kidney anomalies were screened using an in-house-designed kidney-gene panel. In families where candidate variants were not identified, whole-exome sequencing was performed. Genes uncovered by this analysis were added to our kidney panel. We identified likely deleterious variants in 11 of 56 (20%) families. The kidney-gene analysis revealed likely deleterious variants in known kidney developmental genes in 6 fetuses and TMEM67 variants in 2 unrelated fetuses. Kidney histology was similar in the latter 2 fetuses-presenting a distinct prenatal form of nephronophthisis. Exome sequencing identified ROBO1 variants in one family and a GREB1L variant in another family. GREB1L and ROBO1 were added to our kidney-gene panel and additional variants were identified. Next-generation sequencing substantially contributes to identifying causes of fetal kidney anomalies. Genetic causes may be supported by histological examination of the kidneys. This is the first time that SLIT-ROBO signaling is implicated in human bilateral kidney agenesis.

Uncontrolled hypertension is associated with coronary artery calcification and electrocardiographic left ventricular hypertrophy: a case-control study

We conducted a 1:2 matched case-control study in order to evaluate whether the prevalence of coronary artery calcium (CAC) and electrocardiographic left ventricular hypertrophy (LVH) or strain was higher in patients with uncontrolled hypertension than in subjects from the general population, and evaluate the association between CAC and LVH in patients with uncontrolled hypertension. Cases were patients with uncontrolled hypertension, whereas the controls were random individuals from the general population without cardiovascular disease. CAC score was assessed using a non-contrast computed tomographic scan. LVH was evaluated using the Sokolow-Lyon voltage combination and Cornell voltage-duration product, respectively. Associations between CAC, LVH and traditional cardiovascular risk factors were tested by means of ordinal, conditional and classic binary logistic regression models. We found that uncontrolled hypertension was independently associated with both an ordinal CAC score category (odds ratio (OR) 3.9 (95% CI, 1.6-9.1), P = 0.002), the presence of CAC score>99 (OR 4.5 (95% CI, 1.4-14.7), P = 0.01) and electrocardiographic LVH (OR 10.1 (95% CI, 3.4-30.2), P < 0.001) on both univariate and multivariable analyses. There was, however, no correlation between CAC and LVH. The lack of an association between CAC and LVH suggests that they are markers of different complications of hypertension and may have independent predictive values. Patients with both CAC and LVH may be at higher risk than those in whom only one of these markers is present.

Job strain in relation to body mass index: pooled analysis of 160 000 adults from 13 cohort studies

BACKGROUND

Evidence of an association between job strain and obesity is inconsistent, mostly limited to small-scale studies, and does not distinguish between categories of underweight or obesity subclasses.

OBJECTIVES

To examine the association between job strain and body mass index (BMI) in a large adult population.

METHODS

We performed a pooled cross-sectional analysis based on individual-level data from 13 European studies resulting in a total of 161 746 participants (49% men, mean age, 43.7 years). Longitudinal analysis with a median follow-up of 4 years was possible for four cohort studies (n = 42 222).

RESULTS

A total of 86 429 participants were of normal weight (BMI 18.5-24.9 kg m(-2) ), 2149 were underweight (BMI < 18.5 kg m(-2) ), 56 572 overweight (BMI 25.0-29.9 kg m(-2) ) and 13 523 class I (BMI 30-34.9 kg m(-2) ) and 3073 classes II/III (BMI ≥ 35 kg m(-2) ) obese. In addition, 27 010 (17%) participants reported job strain. In cross-sectional analyses, we found increased odds of job strain amongst underweight [odds ratio 1.12, 95% confidence interval (CI) 1.00-1.25], obese class I (odds ratio 1.07, 95% CI 1.02-1.12) and obese classes II/III participants (odds ratio 1.14, 95% CI 1.01-1.28) as compared with participants of normal weight. In longitudinal analysis, both weight gain and weight loss were related to the onset of job strain during follow-up.

CONCLUSIONS

In an analysis of European data, we found both weight gain and weight loss to be associated with the onset of job strain, consistent with a 'U'-shaped cross-sectional association between job strain and BMI. These associations were relatively modest; therefore, it is unlikely that intervention to reduce job strain would be effective in combating obesity at a population level.

Electrospray ionization tandem mass spectrometry sequencing of novel skin peptides from Ranid frogs containing disulfide bridges

Tandem mass spectrometry sequencing, as well as Edman sequencing of peptides belonging to the Rana genus, represents a difficult task due to the presence of a disulfide bridge at the C-terminus and their rather high molecular masses (over 2000 Da). The present study throws light upon the sequence of three rather long peptides (more than 20 amino acid residues each) isolated from the skin secretion of Russian frogs, Rana ridibunda and Rana arvalis. This novel aspect involves the fact that the sequences (including two sequences established de novo) were determined exclusively by means of mass spectrometry. A combination of electron capture dissociation (ECD) and collision-induced dissociaiton (CID) data accompanied by exact mass measurements (LTQ Fourier transform ion cyclotron resonance mass spectrometer) facilitated reaching the goal. To overcome the difficulty dealing with disulphide bridges ("Rana box"), reduction of the S-S bond with dithiotreitol followed by derivatization of Cys residues with iodoacetamide was used. The sequence was determined using combined spectral data on y and b series of fragment ions. A multiple mass spectrometry (MS(3)) experiment was also used to elucidate the sequence inside the "Rana box" after cysteine derivatization. Exact mass measurements were used to differentiate between Lys and Gln residues, while characteristic losses of 29 and 43 Da (d and w fragment ions) in CID and ECD experiments allowed us to distinguish between Ile and Leu isomeric acids.

Continuous cultivations of a Penicillium chrysogenum strain expressing the expandase gene from Streptomyces clavuligerus: Kinetics of adipoyl-7-aminodeacetoxycephalosporanic acid and byproduct formations

The production kinetics of a transformed strain of Penicillium chrysogenum expressing the expandase gene from Streptomyces clavuligerus was investigated in chemostat cultivations. The recombinant strain produces adipoyl-7-aminodeacetoxycephalosporanic acid (ad-7-ADCA) as the major product; however, during the cultivations, the appearance of a major unknown and poorly secreted product was observed. Investigations using high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectroscopy (LC-MS) showed that this byproduct has a six-membered dihydrothiazine ring, which is characteristic for cephalosporins. The byproduct may be formed via isopenicillin N by as-yet unknown mechanisms, but involving expandase. It is likely that the unknown compound (UC) is deacetoxycephalosporin C (DAOC). Investigation of the instability of the various beta-lactams produced showed higher instability for compounds with a five-membered thiazolidine ring than those with a six-membered dihydrothiazine ring. Furthermore, secretion of products and byproducts was shown to be quite different. The productivity was studied as a function of the dilution rate in the range 0.015 to 0.090 h(-1). The specific productivity of total beta-lactams was compared with that of the penicillin-G-producing host strain, and it was found to be lower at dilution rates of <0.06 h(-1). Quantification of the fluxes through the pathway leading to ad-7-ADCA showed a decrease in flux toward ad-7-ADCA, and an increase in flux toward UC as the dilution rate increased. Northern analysis of the biosynthetic genes showed that expression of the enzymes involved in the ad-7-ADCA pathway decreased as the dilution rate increased.

Life expectancies among survivors of acute cerebrovascular disease

BACKGROUND AND PURPOSE

Stroke survivors represent a large group of persons for whom age-differentiated life expectancy tables do not exist. Such tables are vital for many purposes. The aim of the present study was to estimate age- and sex-specific life expectancies among individuals who have survived the acute phase (1 month) of a cerebrovascular disease (CVD).

METHODS

All patients who were registered with the Swedish National Hospital Discharge Registry with an admission for CVD (ICD codes 430 to 438) between January 1, 1989, and November 30, 1993, and were alive at the end of 1993 (N=103 591) were followed for mortality rates in 1994. The same was done for 1983. Actuarial analyses were used to convert death rates into life expectancies.

RESULTS

Life expectancy among CVD survivors increased with time (1983 versus 1994): 22.9% for men (95% CI 18.3% to 27.6%) and 12.9% for women (95% CI 9.1% to 16.6%). The life expectancy ratio in 1983 between CVD survivors and the general population was 0.571 (95% CI 0.533 to 0.590) for men and 0.578 (95% CI 0.562 to 0.592) for women. In 1994, the corresponding ratios were 0.641 (95% CI 0.629 to 0.654) and 0.611 (95% CI 0.601 to 0.622). The life expectancy ratios between female and male survivors were 1.28 (95% CI 1.23 to 1.34) in 1983 and 1.18 (95% CI 1.15 to 1.21) in 1994. The prognosis for survivors who experienced occlusion and stenosis of the precerebral arteries was better than that for survivors of an intracerebral hemorrhage (P=4.4E-4) or occlusion of cerebral arteries (P=3.8E-8).

CONCLUSIONS

Although the prognosis has improved for all ages, stroke survivors still constitute a large group of persons with a low life expectancy compared with the general population.

A family of DNA repeats in Aspergillus nidulans has assimilated degenerated retrotransposons

In the course of a chromosomal walk towards the centromere of chromosome IV of Aspergillus nidulans, several cross-hybridizing genomic cosmid clones were isolated. Restriction mapping of two such clones revealed that their restriction patterns were similar in a region of at least 15 kb, indicating the presence of a large repeat. The nature of the repeat was further investigated by sequencing and Southern analysis. The study revealed a family of long dispersed repeats with a high degree of sequence similarity. The number and location of the repeats vary between wild isolates. Two copies of the repeat contained degenerated long-terminal-repeat (LTR) retrotransposons, which were named Dane1 and Dane2 (for Degenerated Aspergillus nidulans element). The pattern of degeneration suggested that a process similar to the repeat-induced point-mutation (RIP) phenomenon, first described in Neurospora crassa, may have operated in A. nidulans. The data indicate that this family of repeats has assimilated mobile elements that subsequently degenerated but then underwent further duplications as a part of the host repeats.

Advantages of external accumulation for electron capture dissociation in Fourier transform mass spectrometry

A combination of external accumulation (XA) with electron capture dissociation (ECD) improves the electron capture efficiency, shortens the analysis time, and allows for rapid integration of multiple scans in Fourier transform mass spectrometry. This improves the signal-to-noise ratio and increases the number of detected products, including structurally important MS3 fragments. With XA-ECD, the range of the labile species amenable to ECD is significantly extended. Examples include the first-time determination of the positions of six GalNAc groups in a 60-residue peptide, five sialic acid and six O-linked GalNAc groups in a 25-residue peptide, and the sulfate group position in a 11-residue peptide. Even weakly bound supramolecular aggregates, including nonspecific peptide complexes, can be analyzed with XA-ECD. Preliminary results are reported on high-rate XA-ECD that uses an indirectly heated dispenser cathode as an electron source. This shortens the irradiation time to > or = 1 ms and increases the acquisition rate to 3 scans/s, an improvement by a factor of 10-100.

Genetic and physical mapping of two centromere-proximal regions of chromosome IV in Aspergillus nidulans

Chromosome IV is the smallest chromosome of Aspergillus nidulans. The centromere-proximal portion of the chromosome was mapped physically using overlapping clones of a cosmid genomic library. Two contiguous segments of a physical map, based on restriction mapping of cosmid clones, were generated, together covering more than 0.4 Mb DNA. A reverse genetic mapping approach was used to establish a correlation between physical and genetic maps; i.e., marker genes were integrated into physically mapped segments and subsequently mapped by mitotic and meiotic recombination. The resulting data, together with additional classical genetic mapping, lead to a substantial revision of the genetic map of the chromosome, including the position of the centromere. Comparison of physical and genetic maps indicates that meiotic recombination is low in subcentromeric DNA, its frequency being reduced from 1 crossover per 0.8 Mb to approximately 1 crossover per 5 Mb per meiosis. The portion of the chromosome containing the functional centromere was not mapped because repeat-rich regions hindered further chromosome walking. The size of the missing segment was estimated to be between 70 and 400 kb.

Comparison of electron capture dissociation and collisionally activated dissociation of polycations of peptide nucleic acids

Electron capture dissociation (ECD) in Fourier transform ion cyclotron resonance mass spectrometry coupled with electrospray ionization enhances the sequence elucidation of peptide nucleic acids compared with conventional low-energy collisionally activated dissociation (CAD). Examples are shown where ECD produced complete or extensive sequence coverage in PNAs six to ten nucleobases long. However, facile base losses from the reduced species and low abundances of backbone ECD fragments presented a significant problem. This was rationalized through the lower degree of charge solvation on the backbone compared to polypeptides. Combination of both CAD and ECD data is advantageous, as these techniques produce cleavages at different sites.

Yeast chromosomes have been significantly reshaped during their evolutionary history

The structure of the first eukaryotic genome, belonging to Saccharomyces cerevisiae, has been deduced; however, very little is known about its origin. In order to trace events that led to the current state of the Saccharomyces nuclear genomes, random fragments of genomic DNA from three yeasts were sequenced and compared to the S. cerevisiae database sequence. Whereas, S. cerevisiae and Saccharomyces bayanus show perfect synteny, a significant portion of the analysed fragments from Saccharomyces servazzii and Saccharomyces kluyveri show a different arrangement of genes when compared to S. cerevisiae. When the sequenced fragments were probed to the corresponding karyotype, a group of genes present on a single chromosome of S. servazzii and S. kluyveri had homologues scattered on several S. cerevisiae chromosomes. Apparently, extensive reorganisation of the chromosomes has taken place during evolution of the Saccharomyces yeasts. In addition, while one gross duplication could have taken place, at least a few genes have been duplicated independently at different time-points in the evolution.

Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, the current state of knowledge regarding pathologic prognostic factors (factors linked to outcome) and predictive factors (factors predicting response to therapy) in colorectal carcinoma was evaluated. A multidisciplinary group of clinical (including the disciplines of medical oncology, surgical oncology, and radiation oncology), pathologic, and statistical experts in colorectal cancer reviewed all relevant medical literature and stratified the reported prognostic factors into categories that reflected the strength of the published evidence demonstrating their prognostic value. Accordingly, the following categories of prognostic factors were defined. Category I includes factors definitively proven to be of prognostic import based on evidence from multiple statistically robust published trials and generally used in patient management. Category IIA includes factors extensively studied biologically and/or clinically and repeatedly shown to have prognostic value for outcome and/or predictive value for therapy that is of sufficient import to be included in the pathology report but that remains to be validated in statistically robust studies. Category IIB includes factors shown to be promising in multiple studies but lacking sufficient data for inclusion in category I or IIA. Category III includes factors not yet sufficiently studied to determine their prognostic value. Category IV includes factors well studied and shown to have no prognostic significance.

MATERIALS AND METHODS

The medical literature was critically reviewed, and the analysis revealed specific points of variability in approach that prevented direct comparisons among published studies and compromised the quality of the collective data. Categories of variability recognized included the following: (1) methods of analysis, (2) interpretation of findings, (3) reporting of data, and (4) statistical evaluation. Additional points of variability within these categories were defined from the collective experience of the group. Reasons for the assignment of an individual prognostic factor to category I, II, III, or IV (categories defined by the level of scientific validation) were outlined with reference to the specific types of variability associated with the supportive data. For each factor and category of variability related to that factor, detailed recommendations for improvement were made. The recommendations were based on the following aims: (1) to increase the uniformity and completeness of pathologic evaluation of tumor specimens, (2) to enhance the quality of the data needed for definitive evaluation of the prognostic value of individual prognostic factors, and (3) ultimately, to improve patient care.

RESULTS AND CONCLUSIONS

Factors that were determined to merit inclusion in category I were as follows: the local extent of tumor assessed pathologically (the pT category of the TNM staging system of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer [AJCC/UICC]); regional lymph node metastasis (the pN category of the TNM staging system); blood or lymphatic vessel invasion; residual tumor following surgery with curative intent (the R classification of the AJCC/UICC staging system), especially as it relates to positive surgical margins; and preoperative elevation of carcinoembryonic antigen elevation (a factor established by laboratory medicine methods rather than anatomic pathology). Factors in category IIA included the following: tumor grade, radial margin status (for resection specimens with nonperitonealized surfaces), and residual tumor in the resection specimen following neoadjuvant therapy (the ypTNM category of the TNM staging system of the AJCC/UICC). (ABSTRACT TRUNCATED)

Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, the current state of knowledge regarding pathologic prognostic factors (factors linked to outcome) and predictive factors (factors predicting response to therapy) in colorectal carcinoma was evaluated. A multidisciplinary group of clinical (including the disciplines of medical oncology, surgical oncology, and radiation oncology), pathologic, and statistical experts in colorectal cancer reviewed all relevant medical literature and stratified the reported prognostic factors into categories that reflected the strength of the published evidence demonstrating their prognostic value. Accordingly, the following categories of prognostic factors were defined. Category I includes factors definitively proven to be of prognostic import based on evidence from multiple statistically robust published trials and generally used in patient management. Category IIA includes factors extensively studied biologically and/or clinically and repeatedly shown to have prognostic value for outcome and/or predictive value for therapy that is of sufficient import to be included in the pathology report but that remains to be validated in statistically robust studies. Category IIB includes factors shown to be promising in multiple studies but lacking sufficient data for inclusion in category I or IIA. Category III includes factors not yet sufficiently studied to determine their prognostic value. Category IV includes factors well studied and shown to have no prognostic significance.

MATERIALS AND METHODS

The medical literature was critically reviewed, and the analysis revealed specific points of variability in approach that prevented direct comparisons among published studies and compromised the quality of the collective data. Categories of variability recognized included the following: (1) methods of analysis, (2) interpretation of findings, (3) reporting of data, and (4) statistical evaluation. Additional points of variability within these categories were defined from the collective experience of the group. Reasons for the assignment of an individual prognostic factor to category I, II, III, or IV (categories defined by the level of scientific validation) were outlined with reference to the specific types of variability associated with the supportive data. For each factor and category of variability related to that factor, detailed recommendations for improvement were made. The recommendations were based on the following aims: (1) to increase the uniformity and completeness of pathologic evaluation of tumor specimens, (2) to enhance the quality of the data needed for definitive evaluation of the prognostic value of individual prognostic factors, and (3) ultimately, to improve patient care.

RESULTS AND CONCLUSIONS

Factors that were determined to merit inclusion in category I were as follows: the local extent of tumor assessed pathologically (the pT category of the TNM staging system of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer [AJCC/UICC]); regional lymph node metastasis (the pN category of the TNM staging system); blood or lymphatic vessel invasion; residual tumor following surgery with curative intent (the R classification of the AJCC/UICC staging system), especially as it relates to positive surgical margins; and preoperative elevation of carcinoembryonic antigen elevation (a factor established by laboratory medicine methods rather than anatomic pathology). Factors in category IIA included the following: tumor grade, radial margin status (for resection specimens with nonperitonealized surfaces), and residual tumor in the resection specimen following neoadjuvant therapy (the ypTNM category of the TNM staging system of the AJCC/UICC). (ABSTRACT TRUNCATED)

Computerized training and proficiency testing. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial

ISSUES

Computerized technologies probably will revolutionize the field of gynecologic cytology in the next century. Such technologies will be useful in both training and evaluating proficiency. However, manual screening/review of gynecologic cytology preparations is the current "gold standard" for both training and assessment of proficiency.

CONSENSUS POSITION

Training programs for cytotechnologists and pathologists should provide instruction and experience in new technologies, but their introduction may depend on the availability of equipment and staff. Advantages of digital images for training include standardization of teaching sets and interactive capabilities, allowing educational feedback. Computerized support/assistance devices aid in complete screening of the slide during training and provide feedback to cytologists on screening techniques. Liquid-based cytopreparatory instruments facilitate multiple glass slides for teaching or testing. Proficiency testing (PT) in cytology has similar quality assurance goals as in other areas of the laboratory, but the subjective nature of cytologic analysis poses many challenges for implementation. There is consensus that all cytology practitioners would like to know the proficiency of the laboratory. However, the majority question the value and validity of any large-scale formal testing programs. Locator and diagnostic skills are both critical in cytology, but assessment of each skill may occur in different ways using computerized technologies. Any type of assessment should provide educational feedback to participants. Psychometric issues in PT include the consideration of different types of validity, including face, content, construct and criterion related. The reliability or consistency of the testing event is also critical. A valid and reliable correlation between work performance and performance on a PT needs to be established. The goal is to ensure that PT will identify submarginal practitioners and that persons successful on PT are in fact competent. Any cytology PT program should also be considered in the context of other laboratory quality assurance tools and the entire cervical cancer screening program. Regulatory agencies should evaluate entire laboratory performance, while each laboratory director should assume primary responsibility for evaluating and documenting the competency and daily performance of each practicing cytologist. Professional scientific organizations should take the lead in recommending methods and standards of performance assessment.

ONGOING ISSUES

A reliable method of correlating daily competency with results on PT is not yet established. Methods may evolve ever time using new technologies. The use of computerized techniques and images for assessment will require careful deliberation by experts as well as validation by practicing cytologists. Variables include diagnostic categories for testing, numbers of challenges per testing event, types of slide preparations and characteristics of the digital images. Availability of equipment and staff will affect the introduction of new technologies in different regions.

Cytopathology laboratory improvement programs of the College of American Pathologists: Laboratory Accreditation Program (CAP LAP) and Performance Improvement Program in Cervicovaginal Cytology (CAP PAP)

Major programs of the College of American Pathologists (CAP) are directed toward improvement of laboratory practices through peer review, interlaboratory comparison, education, and development of practice standards and guidelines. Two programs provided to cytopathology laboratories, the Laboratory Accreditation Program and the Interlaboratory Comparison Program in Cervicovaginal Cytology, are dedicated to these laboratory improvement principles. In 1996, each of these programs served over 2100 laboratories that provide cytopathology services. This paper reviews the peer development, structure, and administration of the Laboratory Accreditation Program and the Interlaboratory Comparison Program in Cervicovaginal Cytology, focusing on recent and ongoing initiatives to enhance their contribution to continued improvement of gynecologic cytopathology laboratory practices.

Atypical squamous cells of undetermined significance. Current laboratory practices of participants in the College of American Pathologists Interlaboratory. Comparison Program in Cervicovaginal Cytology

OBJECTIVE

To evaluate current laboratory practices and rates for atypical squamous cells of undetermined significance (ASCUS), a category of epithelial cell abnormality in the Bethesda System.

DESIGN

Questionnaire surveys were mailed in December 1993 and March 1994.

SETTING

Cytopathology laboratory participants in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology (PAP).

RESULTS

Most responding laboratories (82.5%) limited the use of "atypia" terminology to abnormalities of undetermined significance. Nearly half of the laboratories employed only the term ASCUS for squamous epithelial changes in this category. The median rate of ASCUS in 1993 was 2.8%, with 10% of laboratories reporting rates greater than 9.0%. The median squamous intraepithelial lesion rate was 2.0%, with a median ASCUS-squamous intraepithelial lesion ratio of 1.3. The majority of laboratories qualified a portion of ASCUS cases and issued recommendations for follow-up when appropriate. Fifty-six percent of laboratories surveyed included patients diagnosed with ASCUS in follow-up programs. Laboratories estimated that about 20% (median response) of patients with ASCUS smears had a squamous intraepithelial lesion or equivalent diagnosis made within a year's follow-up.

CONCLUSIONS

The ASCUS category is used by the majority of laboratories as recommended by the Bethesda System, but reporting rates vary. The results of this survey and associated surveys provide laboratories with useful benchmark figures for interlaboratory comparison of ASCUS practices.

Traffic-related air pollution: exposure and health effects in Copenhagen street cleaners and cemetery workers

This questionnaire-based study found a significantly higher prevalence of chronic bronchitis, asthma, and several other symptoms in 116 Copenhagen street cleaners who were exposed to traffic-related air pollution at levels that were slightly lower than the 1987 World Health Organization-recommended threshold values, compared with 115 Copenhagen cemetery workers exposed to lower pollution levels. Logistic regression analysis, controlling for age and smoking, was conducted, and odds ratios and 95% confidence intervals were calculated to be 2.5 for chronic bronchitis (95% confidence interval = 1.2-5.1), 2.3 for asthma (95% confidence interval = 1.0-5.1), and 1.8-7.9 for other symptoms (95% confidence interval = 1.0-28.2). Except for exposure to air pollution, the two groups were comparable, i.e., they had similar terms of employment and working conditions. The exposure ranges during an 8-h work day, averaged from readings taken at five monitored street positions, were: 41-257 ppb nitric oxide (1-h max: 865 ppb); 23-43 ppb nitrogen dioxide (1-h max: 208 ppb); 1.0-4.3 ppm carbon monoxide (8-h max: 7.1 ppm); 14-28 ppb sulfur dioxide (1-h max: 112 ppb); and 10-38 ppb ozone (1-h max: 72 ppb).

Atypical squamous cells of undetermined significance: interlaboratory comparison and quality assurance monitors

The Bethesda System recognizes "Atypical Squamous Cells of Undetermined Significance" (ASCUS) as a category of epithelial cell abnormality. Neither the acceptable rate of ASCUS nor the clinical follow-up are well defined. This study focused on interlaboratory comparison and quality assurance methods for evaluating the rate and outcome of ASCUS. Data was collected from questionnaire surveys from the College of American Pathologists Interlaboratory PAP Program and the four authors' laboratories. Most PAP laboratories (82.5%) limit the use of "atypia" terminology to abnormalities of undetermined significance. According to PAP data, the median rate of ASCUS in 1992 was 2.9%, with 10% of laboratories reporting rates greater than 9.0%. The median squamous intraepithelial lesion (SIL) rate was 2.2%, with a median ASCUS/SIL ration of 1.3. The authors' laboratories (university, independent, and hospital) revealed ASCUS rates of 1.6-9.0%, while SIL rates were 2.1-9.0%. The ASCUS/SIL ratio was less variable, 0.8-2.7. Follow-up of ASCUS patients in the authors' laboratories showed 10.3-43% with SIL, but less than 6% with high grade SIL. The ratio ASCUS/SIL may serve as a useful laboratory monitor. Peer review and follow-up studies of ASCUS serve to validate laboratory criteria and consequent clinical follow-up. Communication with clinicians is vital in ensuring optimal patient care.

Improving accuracy in gynecologic cytology. Results of the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology

The College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology (PAP) is a quarterly mailed glass-slide quality improvement program. This growing program started as a pilot in 1989 with 207 laboratories. In 1991, 605 laboratories participated. The diagnostic menu is modified from the Bethesda System and divides referenced slides into a negative series (normal, infectious, and reactive) and a positive series of epithelial lesions. A facsimile option facilitates immediate educational feedback. The 1989 through 1991 major discrepancy rate averaged 5%. The consensus laboratory response had higher concordance than either pathologist or cytotechnologist responses. Low-grade squamous intraepithelial lesion was the leading cause of false-negative participant response, while reactive/reparative change was the leading cause of false-positive response. Pathologist false-negative and false-positive responses from group or large case-volume practices were significantly lower than those from solo or small case-volume practices. Cytotechnologists in multiple-technologist or large-volume laboratories had significantly lower false-negative responses than solo technologists or those in low case-volume laboratories, but false-positive rates did not differ. Experienced participants had fewer major discrepancies. The Interlaboratory Comparison Program in Cervicovaginal Cytology illustrates the feasibility of a large, mailed glass-slide program, and offers laboratories a continuous method for monitoring and improving performance in gynecologic cytology.

Specimen adequacy evaluation in gynecologic cytopathology: current laboratory practice in the College of American Pathologists Interlaboratory Comparison Program and tentative guidelines for future practice

Routine specimen adequacy evaluation, as advocated by The Bethesda System (TBS), can play an important role in improving the sensitivity and accuracy of cervical cytopathology screening. The effectiveness of this measure, however, has been limited by the lack of uniform criteria for adequacy. Practice parameters are now emerging, through TBS development of tentative criteria and interlaboratory comparison of adequacy practices. This study reviews 1) nationwide responses to surveys of laboratory practices in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology (CAP PAP); 2) the definitions of adequacy based on TBS; and 3) the results of implementation of these criteria in a private independent laboratory, university hospital laboratory, and private nonprofit hospital laboratory. In the initial CAP PAP survey in 1990, 35% of responding laboratories routinely reported specimen adequacy, increasing to 66% in 1991 and 85% in 1992. Interlaboratory variations in adequacy practices were observed, however, underscoring the need for consensus criteria. The experience in the authors' laboratories indicates that TBS criteria can serve as a sound guideline. Effective implementation of adequacy assessment in the individual laboratory requires careful attention to ensuring the quality of adequacy ratings, correlating clinical and prior laboratory information, issuing clear and concise reports, and giving recommendations judiciously. Through interlaboratory comparison and consistent intralaboratory emphasis on specimen adequacy, greater uniformity of adequacy assessment can be achieved, and adequacy evaluation can achieve its promise of improving the quality of cervical cytopathology.

Terminology and specimen adequacy in cervicovaginal cytology. The College of American Pathologists Interlaboratory Comparison Program experience

The 600 participants in the College of American Pathologists 1991 Interlaboratory Comparison Program in Cervicovaginal Cytology were surveyed by mailed questionnaire in March 1991. The total annual gynecologic specimen volume of the 362 respondents was over 7 million. Nearly all participants (94%) used a descriptive diagnosis for cases not within normal limits. Most (87%) have implemented or plan to implement the Bethesda System. A Papanicolaou class system was not used by 66%. Terminology for reporting squamous lesions with premalignant potential was variable, with many laboratories using two or more sets of terms. Specimen adequacy was routinely reported by 66% of participants. Median rates of unsatisfactory and "less than optimal" specimens reported by participants in 1990 were 0.5% to 0.9% (range, 0% to greater than 20%) and 3.0% to 4.9% (range, 0% to greater than 40%), respectively. Leading reasons for both unsatisfactory and less than optimal smears included scant cellularity, obscuring inflammation, obscuring blood or menses, and poor preservation. Absent endocervical component was also a leading reason for less than optimal specimens. The largest number of respondents required endocervical columnar cells and/or metaplastic cells as the criteria for an endocervical component. In conclusion, nearly all laboratories use descriptive terminology for smears that are abnormal, and most laboratories routinely report specimen adequacy. Frequency and criteria for unsatisfactory and less than optimal smears vary significantly, supporting the need for consensus definitions of specimen adequacy.

Intraincisional antibiotic in addition to systemic antibiotic treatment fails to reduce wound infection rates in contaminated abdominal surgery. A controlled clinical trial

One hundred ninety patients with peritonitis at the time of abdominal surgery were allocated at random to systemic antibiotic treatment alone or systemic antibiotic treatment combined with topical application of antibiotics in the wound at the time of wound closure. The overall wound infection rate was 17 percent without significant difference between the two treatment groups (P greater than 0.80).

Excretion, deconjugation, and absorption of bile acids after colectomy for ulcerative colitis. Comparative studies in patients with conventional ileostomy and patients with Kock's reservoir

Bile acid metabolism was studied in 26 patients with a continent ileostomy (Kock's reservoir) and 32 patients with conventional ileostomy. All had been colectomized for ulcerative colitis. In patients with a continent ileostomy the 14C-glycocholic acid breath test showed increased pulmonary 14CO2 excretion as evidence of abnormal bacterial deconjugation of bile acids and increased faecal 14C excretion as evidence of bile acid malabsorption. Faecal bile acid excretion, determined chemically, and, by inference, bile acid synthesis were only moderately increased (median, 1.8 mmol/day). The disturbance of bile acid metabolism was similar to that found in 32 patients with conventional ileostomy, but more pronounced with higher faecal 14C. A significant difference was that no abnormal bacterial deconjugation took place in patients with conventional ileostomy, since their pulmonary 14CO2 excretion was subnormal. Stool mass was almost identical in the two groups, with median values of 665 and 663 g/day, respectively. Faecal fat excretion was normal in most in both groups. Thus bile acid metabolism is slightly more disturbed in patients with a continent ileostomy than in patients with conventional ileostomy. The resulting malabsorption was modest in both groups.

Treatment of abscesses in the vulva. Conventional open treatment versus primary suture under antibiotic cover

Seventy patients were treated for a subcutaneous abscess in the vulva. In 35 consecutive patients the abscess was treated conventionally with deroofing of the abscess and wet dressings. In the other 35 consecutive patients the abscess was treated by incision, curettage and primary suture under antibiotic cover with a single dose of clindamycin. In the conventionally treated group the median stay in hospital was 7 days and the median healing time 18 days. In the group treated by primary suture the median stay in hospital was 2 days and the median healing time 7 days (P less than 0.0001). Recurrence of abscess was observed in one patient in each group. No other complications were observed in either group. It is concluded that vulvar abscesses may be treated safely and advantageously by primary suture under antibiotic cover.

New approach to treatment of severe incisional abscesses following laparotomy. Wound closure under systemic antibiotic cover four days after drainage

Forty consecutive patients who developed subcutaneous abscesses after intraperitoneal operations were treated by incision and drainage followed by suture of the wound four days later under antibiotic cover. The wound was closed by means of interrupted Prolene sutures. No sutures were placed in the wound cavity, and no drain was applied. The antibiotic used was clindamycin 600 mg intravenously peroperatively and 150 mg every six hours for four days.

Adhesives for retaining prefixed urothelial cells on slides after imprinting from cellulosic filters

Cells of prefixed urine specimens collected on Millipore filters can be imprinted onto labelled microslides coated with adhesives. The proportion of cells transferred to the slides and recovered from the filters was investigated using three different adhesives. Egg albumen-glycerin and Apathy's syrup did not increase the transfer of cells as compared with experiments without adhesives; the proportion of transferred cells varied from less than 10% to more than 70%. Gelatin-chrome alum had, with minor variations, a pronounced adhesive effect: at least 94% of the cells was always recovered after the cells were transferred from filters to slides. Practical details, including advantages of the filter imprint method, are discussed.

Sterilization by vas occlusion without transection does not reduce postvasectomy sperm-agglutinating antibodies in serum. A randomized trial of vas occlusion versus vasectomy

The influence of transection of the vasa on the increase in sperm-agglutinating activity in serum after vasectomy was investigated in a prospective randomized study. Sixty-eight males requesting vasectomy were allocated to either of two groups: vas occlusion by tantalum clips without transection of the vasa, or conventional vasectomy by transection and ligation. Sperm-agglutinating antibodies were determined by a micro-agglutination test before and 6 months after vasectomy or vas occlusion. A significant increase in sperm-agglutinating activity in serum after sterilization was found in both groups, but there was no intergroup difference.

Release of gastric inhibitory polypeptide and insulin in response to intrajejunal glucose in duodenal ulcer patients before and after truncal vagotomy

Six duodenal ulcer patients were investigated before and 3 months after truncal vagotomy and pyloroplasty. Plasma concentrations of gastric inhibitory polypeptide (GIP), insulin, and glucose were measured during intrajejunal infusion of 50 g of glucose. The GIP response was significantly diminished postoperatively; insulin and glucose concentrations, however, were unchanged. The reduction of GIP release was positively correlated with the reduction of the peak acid output. The results suggest that a reduced vagal innervation of the intestine is accompanied by reduced GIP release after intrajejunal glucose, depending on the degree of completeness of vagotomy.

Increased abnormal urothelial cells in voided urine following excretory urography

A prospective study of 45 consecutive patients scheduled for excretory urography demonstrated a statistically significant increase in the proportion of abnormal urothelial cells, including pseudomalignant cells, recovered in the urine between three hours and seven days after urography. The total number of urothelial cells recovered in the urine did not increase at any time. The Millipore filter imprint technique, which allows semiquantitative examination of urothelial cells from urine, is discussed.

Protective choledochoduodenostomy in multiple common duct stones in the aged

Forty-nine patients more than 70 years of age had a follow-up examination two to eight years after choledochoduodenostomy for common duct stones or for common duct strictures following a previous biliary tract operation. Death followed operation in two patients and was not related to the choledochoduodenostomy itself. Results of the follow-up examination revealed that none of the patients had had signs or symptoms of cholangitis, jaundice or episodes of fever. One patient only had recurrent, but mild, biliary colic. Choledochoduodenostomy is well tolerated in old age and justified in elderly patients with multiple stones in dilated common ducts as a precaution against retained or recurrent common duct stones.

Basal hyposecretion of gastric inhibitory polypeptide after Roux-Y hepaticojejunostomy in man

We previously showed that basal and pentagastrin-stimulated gastric acid secretion, gastrin in serum and gastrin in antral mucosa were significantly greater in patients with Roux-Y hepaticojejunostomy than in those with choledochoduodenostomy. These findings prompted investigation of basal secretion of gastric inhibitory polypeptide (a peptide with an enterogastrone as well as an insulinogenic effect), insulin and glucose in the same patients. Basal gastric inhibitory polypeptide was significantly lower in patients with Roux-Y hepaticojejunostomy than in those with choledochoduodensotomy, whereas glucose and insulin did not differ in the two groups. No correlation could be demonstrated between gastric inhibitory polypeptide, gastric acid secretion and gastrin, suggesting that hyposecretion of gastric inhibitory polypeptide is not a pathogenetic factor for the hypersecretion of gastric acid secretion in patients with Roux-Y hepaticojejunostomy. Hyposecretion of gastric inhibitory polypeptide and gastric acid hypersecretion in patients with bile diversion seem to be two independent phenomena.