Laboratory techniques for the diagnosis of chlamydial infections

Yolk-sac inoculation of embryonated eggs was superseded 25 years ago by the use of cell cultures (often McCoy) for the isolation of Chlamydia trachomatis. Centrifugation of specimens onto the cell monolayers was shown to increase sensitivity, but little of late has further improved sensitivity which is at least ten-fold greater than that of eggs. However, culture is slow and labour intensive so that non-cultural techniques without these drawbacks have come to dominate. Direct fluorescent antibody (DFA) tests are rapid and have sensitivities that range from 70% to 100% for men and 68% to 100% for women, and specificities that range from 87% to 99% for men and 82% to 100% for women; if the tests are read by competent observers the values are at the top end of the ranges. The detection rate may be enhanced even further by relatively low-speed centrifugation of specimens before staining. Skilled reading is not a feature of enzyme immunoassays (EIAs) which according to the literature have sensitivities that range from 62% to 97% for men and 64% to 100% for women, and specificities that range from 92% to 100% for men and 89% to 100% for women. However, comparison against poor reference tests is responsible for most of the higher values and the clinician should not be misled into believing that EIAs have excellent sensitivity; the lower values in the ranges are closer to reality. Furthermore, EIAs that are being designed for use by general practitioners should be regarded with the greatest caution since lack of sensitivity means that chlamydia-positive patients will go undetected. The polymerase chain reaction (PCR) is not bedevilled by insensitivity but it is no more sensitive than the most sensitive cell culture or DFA tests. PCR is unsuitable for routine diagnosis but has a place as a research tool. For men, examination of "first-catch" urine samples by the best of the non-cultural procedures provides an acceptable non-invasive approach to diagnosis; for women, the value of examining urine may be less, but needs to be thoroughly tested. However, there is little doubt that a Cytobrush used to obtain cervical specimens holds no practical advantage over a swab. Serological tests are reliant on the provision of paired sera for making a diagnosis; high antibody titres in single sera may be suggestive of an aetiological association in deep-seated chlamydial infections (epididymitis, arthritis, salpingitis, etc), but unequivocal interpretation is unusual, particularly in an individual case, since the distinction between a current and past infection is problematical.

Simplification of procedures used to test urine samples for Chlamydia trachomatis

Two methods of simplifying the procedure for examining urine samples for Chlamydia trachomatis were investigated. When 73 urine samples from 56 men with acute non-gonococcal urethritis were examined by direct immunofluorescence (MicroTrak), centrifuging 1 ml volumes of urine at 13,000 rpm for five minutes was at least as efficient for detecting C trachomatis as centrifuging larger volumes at 3000 rpm for 30 minutes. Furthermore, examination of urine produced during a visit to a sexually transmitted disease clinic was at least as efficient as examination of early morning urine for detecting C trachomatis by MicroTrak, or by an enzyme immunoassay (IDEIA). Both modifications have practical advantages and should encourage the use of urine samples for diagnosing chlamydial infections in men.

The value of urine samples from men with non-gonococcal urethritis for the detection of Chlamydia trachomatis

Chlamydia trachomatis was sought at first and subsequent clinic visits in urethral swabs and urines from 112 heterosexual men with acute non-gonococcal urethritis (NGU). In comparison with a urethral swab tested by Micro Trak (MT), a urine deposit tested in the same way was 90% as sensitive. Examining a urine deposit by the enzyme immunoassay IDEIA was a little less sensitive (89%) than examining a similar deposit by MT, and was less sensitive (82%) than examining a urethral swab by MT. The results of testing urines were little influenced by collecting them either before or after swabbing the urethra, and there was evidence that examining all of a urine sample by IDEIA would have increased sensitivity. Overall, 55 (49%) of the men were diagnosed as C trachomatis-positive based on the results of testing both a urethral swab and a urine sample. Furthermore, a small numbers of chlamydiae were detected by examining urine by MT and, to a lesser extent, by IDEIA, so that there is no reason why this non-invasive approach should not be successful in men other than those with acute NGU.

Detection of Chlamydia trachomatis by the polymerase chain reaction in swabs and urine from men with non-gonococcal urethritis

A polymerase chain reaction (PCR) was developed for Chlamydia trachomatis in which a 380 base pair DNA fragment was amplified. Amplification occurred with the DNA from the 15 serovars but not with that from other Chlamydia spp or with DNA from a variety of other organisms. Chlamydial DNA (10(-16) g) could be detected and the PCR seemed to be able to detect single organisms. Urethral swabs were obtained from 37 men with acute non-gonococcal urethritis (NGU), 18 (49%) of whom were positive for C trachomatis by MicroTrak. As a result of clinical re-examinations 65 urethral swabs were available for analysis by the PCR. In comparison with MicroTrak, PCR had a sensitivity of 95%, a specificity of 94%, a positive predictive value of 86% and a negative predictive value of 98%. The PCR was apparently less sensitive (82%) in tests on urine samples. Overall, however, values of sensitivity and specificity of the PCR compared favourably with those of MicroTrak. The PCR for C trachomatis is likely to be a valuable technique for research, but problems of DNA contamination suggest that it should not be recommended for routine diagnosis.

Shoulder arthroplasty for rheumatoid arthritis

Forty-two Designed After Natural Anatomy (DANA) total shoulder arthroplasties (Howmedica, Rutherford, New Jersey) were performed in 34 rheumatoid patients. Thirty shoulders in 23 patients were followed for a minimum of two years. Twelve of the 30 shoulders (40%) had significant rotator cuff tears. The average rating for pain improved from 3 points preoperatively to 8 points postoperatively for the overall group, and the average rating for function improved from 3 points preoperatively to 6 points postoperatively. Range of motion (ROM) improved substantially in patients treated with a regular glenoid component. Four patients were treated with hooded glenoid components designed to improve stability for shoulders in which the rotator cuff was deficient. In the rotator-cuff-deficient patients, pain and function improved; however, ROM was unchanged. Complications, including one acromial fracture and two loose glenoid components, required revision surgery.

Total knee arthroplasty in rheumatoid arthritis. A comparison of the polycentric and total condylar prostheses

From 1971 to 1985, 393 total knee arthroplasties (TKAs) were performed in patients for rheumatoid arthritis. Of these, 112 used polycentric prostheses and 131 used total condylar prostheses. One hundred seven of the patients with polycentric prostheses and 102 of the patients with total condylar prostheses were followed for a minimum of two years (average, 61 and 55 months, respectively). At the time of the latest examination, nine knees with polycentric prostheses required revision surgery: six for tibial component loosening and instability and three for patellofemoral pain. Five knees with total condylar prostheses required revision: one for chronic instability, one for a late posttraumatic patellar fracture, and three for late hematogenous infections. The total condylar prostheses with patellar resurfacing had better scores for pain (8.5 points) than the polycentric prosthesis without patellofemoral resurfacing (7.0 points). The total condylar prosthesis appeared more durable in terms of fixation, with no evidence of aseptic loosening of femoral or tibial components noted in this series thus far.

Equipment design issues for the in vivo X-ray fluorescence analysis of bone lead

Several groups have reported the development of systems, based on the principle of X-ray fluorescence, for the in vivo measurement of bone lead concentrations. These systems have used the detection of either the characteristic L or K X-rays resulting from excitation by a suitable photon source. This paper examines design issues related to the development of these systems. These design issues are, in most instances, a result of consideration of the physical principles involved, and hence there are many features common to the systems developed by the individual groups. Design issues discussed in this paper include the selection of the site for measurement, source-sample-detector configuration, and collimation. Specific examples from published work are used to demonstrate the relevant features.

Periprosthetic chronic inflammation characterized through the measurement of superoxide anion production by synovial-derived macrophages

Periprosthetic macrophages were isolated from the synovium of primary and revision arthroplasty patients. Inflammatory activity was determined by the level of superoxide (O2-) production de novo and in response to phorbol myristate acetate (PMA) stimulation. Nonstimulated primary arthroplasty-derived macrophages produced 2.54 +/- 2.04 pmoles of O2-/minute/10(5) cells. When identical reaction tubes were stimulated with PMA, O2- levels increased to 5.76 +/- 3.77 pmol of O2-/minute/10(5) cells. Nonstimulated revision arthroplasty-derived macrophages produced 3.26 +/- 2.02 pmol of O2-/minute/10(5) cells during this ten-minute time period. When identical reaction tubes were stimulated with PMA, O2- levels increased to 3.98 +/- 2.52 pmol of O2-/minute/10(5) cells. The difference in the ratio of O2- production in response to stimulation between primary and revision groups was statistically significant. The observation of a chronic moderate level of activation and the lack of responsiveness to a potent stimulator suggests that macrophage inflammatory activity is down-regulated in periprosthetic synovium.

Body composition in myelomeningocele

Body composition and measures of obesity were evaluated in 59 subjects with myelomeningocele (MMC), aged 0.3-29 y, by anthropometry and measures of body cell mass (BCM) and intra- and extracellular water (ICW and ECW), derived from total body potassium and deuterium-isotope dilution; these results were compared with reference data. Body composition was normal in preambulatory children with MMC. Beyond ages 3-4 y there was significant depletion of BCM and total body water, with maldistribution of water (increased ECW and decreased ICW) and increased percentage body fat above that expected for age and sex. These findings were more pronounced in females and in those with high lesions, and were less pronounced in those who remained ambulatory. These changes may result in metabolic and nutritional maladaption during stress. The relation of BCM, total body water depletion and increased ECW to decreasing ambulatory activity suggests that early nutritional and mobility programs warrant further study.

Postoperative irradiation for the prevention of heterotopic bone: analysis of different dose schedules and shielding considerations

Ninety-seven high risk hips were irradiated postoperatively for prevention of heterotopic bone (HTB) in the UCLA Department of Radiation Oncology from 1980 to 1988. Ninety-two hips in 82 patients were eligible for analysis with a minimum follow-up of 2 months and a median follow-up of 10 months. Forty-nine of the hips had porous coated ingrowth prostheses. From 1980 to 1986, 2 Gy fractions were used to deliver 20 Gy (8 hips), 12 Gy (1 hip), and 10 Gy (27 hips). Since December of 1986, 38 hips received 8 Gy in two increments and 18 hips received a single 7 Gy fraction. All porous ingrowth components were shielded with custom blocks. Six out of 92 hips developed clinically significant (Brooker grade 3 or 4 heterotopic bone). There was one clinically significant failure in 78 hips (1.3%) when irradiation was initiated before post-operative day (POD) #6 and shielding was properly placed. One clinical failure occurred in 38 hips which received 8 Gy in two increments. One clinical failure occurred out of the 18 hips treated with 7 Gy in one fraction. This failure could be related to block malposition. There were four clinical failures in the 36 hips treated with 2 Gy fractions to total doses of 10 Gy, 12 Gy, or 20 Gy. Three of these failures were associated with initiation of treatment after POD #5, and the fourth was related to block malposition. Unshielded trochanteric osteotomies resulted in five migrations and seven fibrous unions for a total non-osseous union rate of 12/36 (33%). Shielding of the remaining 28 trochanteric osteotomies resulted in a non-osseous union rate of 7% (0 migrations and 2 fibrous unions). There were no failures of union of components, and the only side effects noted in the series were the five trochanteric migrations. In conclusion, the use of 8 Gy in two increments or 7 Gy in one fraction was found to be as efficacious as conventional 2 Gy fractionation schemes with no increase in side effects. For optimal results, treatment should be implemented prior to POD #5 with shielding of the trochanteric osteotomy. Postoperative irradiation to prevent HTB can be used in hips with porous components using properly placed blocks to shield the porous region.

A 2-year quantitative assessment of Chlamydia trachomatis in a sexually transmitted diseases clinic population by the MicroTrak direct smear immunofluorescence test

The MicroTrak direct smear immunofluorescence test was used to determine the prevalence of Chlamydia trachomatis elementary bodies (EBs) in groups of patients in various clinical categories, most of whom were seen in a clinic for sexually transmitted diseases (STD). Overall, 8138 adequate specimens were tested, of which 14.3% were found to contain chlamydial EBs. Of the samples from patients seen in the STD clinic, over 70% were from women and 14.9% of these were positive, as were 15.7% of those from men. EBs were detected in 27% of samples from infants and in 7.0% of those from adults with conjunctivitis. EBs were detected most often in men with nongonococcal urethritis (40.2%), infants with conjunctivitis (30%) and contacts of chlamydiae-positive patients (24.5%) and least often in 'prostatitis' (2.9%) and patients tested to determine the success of treatment (2.7%). Over 40% of samples from both the male urethra and the cervix contained 10 or fewer EBs, highlighting the importance of recognizing small numbers and the sensitivity required of other detection procedures.

Leaf Senescence in a Nonyellowing Mutant of Festuca pratensis: Metabolism of Cytochrome f

In a mutant genotype of Festuca pratensis Huds., net degradation of a number of thylakoid membrane proteins during senescence is impaired. Previous studies have suggested that the highly hydrophobic intrinsic chlorophyll-binding proteins were the definitive subjects of the metabolic lesion. In the present study we find that cytochrome f, as determined by haem-staining, Western blotting, enzyme-linked immunosorbent assay, and immunogold electron microscopy, is also abnormally stable in the mutant. The structural feature common to all the proteins in the mutant so far recognized to be abnormally stable is possession of a tetrapyrrole prosthetic group. It is suggested that degradation of chlorophyll and haem may regulate degradation of the associated apoproteins, and hence has an important role to play in membrane protein turnover and in mobilisation of amino acids during chloroplast disassembly.

The Masters Degree in Medical Physics at Queensland University of Technology--14 years on

In 1975, the Masters Degree in Medical Physics was first made available at the Queensland Institute of Technology (now Queensland University of Technology, QUT), and is offered on both a part time and full time basis. An option for a Graduate Diploma award after completion of the in-house course work stage is available. The research project may be undertaken either in Brisbane or elsewhere. Such projects have been undertaken in Perth, Hong Kong, Sydney, etc. It is a broad based program, embracing activities of current professional importance while including aspects which have potential importance. Recognition that medical physics is a dynamic speciality ensures that the content of the program is kept under continuous review, and changes made as required. It is of interest to observe that of graduates from the course, approximately 50% have moved into the hospitals and private medical research, 11% into government health departments, 16% into the mining industry, 9% into tertiary education, and 14% into non medical or sales areas. Many have gained senior positions in their selected vocations. The success of the program in providing a useful professional person is due in no small measure to the collaboration of many dedicated professionals in the field. This collaboration relates to informal and formal contact between academic staff and students within the Physics Department, and personnel in hospitals, public health establishments and industry.

The genetic control of direct-repeat recombination in Saccharomyces: the effect of rad52 and rad1 on mitotic recombination at GAL10, a transcriptionally regulated gene

We have previously shown direct-repeat recombination events leading to loss of a plasmid integrated at the GAL10 locus in Saccharomyces cerevisiae are stimulated by transcription of the region. We have examined the role of two recombination- and repair-defective mutations, rad1 and rad52, on direct repeat recombination in transcriptionally active and inactive sequences. We show that the RAD52 gene is required for transcription-stimulated recombination events leading to loss of the integrated plasmid. Similarly, Gal+ events between the duplicated repeats that retain the integrated plasmid DNA (Gal+ Ura+ replacement events) are reduced 20-fold in the rad52 mutant in sequences that are constitutively expressed. In contrast, in sequences that are not expressed, the rad52 mutation reduces plasmid loss events by only twofold and Gal+ Ura+ replacements by fourfold. We also observe an increase in disome-associated plasmid loss events in the rad52 mutant, indicative of chromosome gain. This event is not affected by expression of the region. Plasmid loss events in rad1 mutant strains are reduced only twofold in transcriptionally active sequences and are not affected in sequences that are repressed. However, the rad1 and rad52 double mutant shows a decrease in plasmid loss events greater than the sum of the decreases in the rates of this event displayed by either single mutant in both constitutive and repressed DNA, indicating a synergistic interaction between these two genes. The synergism is limited to recombination since the rad1 rad52 double mutant is no more sensitive when compared with either single mutant in its ability to survive radiation damage. Finally, the recombination pathway that remains in the double mutant is positively affected by transcription of the region.

A search for infectious agents in chronic abacterial prostatitis using ultrasound guided biopsy

A series of 60 patients with a diagnosis of chronic abacterial prostatitis, as defined by the Stamey procedure, was studied by transrectal prostatic ultrasound and subsequent transperineal biopsy of the abnormal areas of the prostate in order to ascertain the role of micro-organisms in this condition. Histological assessment revealed a chronic inflammatory infiltrate, generally of low grade, in 53 patients (88%). Organisms were isolated from the prostatic tissue of only 9 patients (15%) and were considered to be contaminants from the perineal skin, since treatment with an appropriate antimicrobial agent failed to alter symptoms or affect the leucocyte count in the urine or prostatic fluid. Chronic abacterial prostatitis may be a non-organismal inflammatory process.

Total body potassium in cystic fibrosis

To further evaluate the nature of malnutrition, define at-risk groups, and confirm the efficacy of nutritional supplementation on body composition in cystic fibrosis (CF), we have conducted longitudinal and cross-sectional studies of total body potassium (TBK) in 161 unselected CF subjects aged 1 month to 17 years. TBK was determined by measurement of 40K in a whole body counter, reflecting body cell mass (BCM), the vital work-performing and growing cellular component of the body. Compared with normal TBK data for age and sex from pooled measurements of 1,629 healthy children aged 1 week to 17 years, CF infants (n = 12) diagnosed by newborn screening were depleted in TBK at diagnosis and showed catch-up with therapy by 1 year; CF children aged 2-17 years (n = 140) showed a tendency for inadequate accretion of TBK (and thus BCM) with increasing age, although the normal correlation between TBK and weight and height was maintained in the majority suggesting a pattern of nutritional stunting of growth; and malnourished CF children (n = 9) showed significant catch-up in TBK with long-term nutritional rehabilitation (85-98% of TBK predicted for weight and height). These studies suggest that potentially serious, but possibly correctable deficits, in the growth of the body cell mass as measured by TBK occur commonly in CF. These deficits may be established very early in life and if not corrected lead to progressive nutritional growth retardation with increasing age.

Improved sensitivity of an enzyme immunoassay IDEIA for detecting Chlamydia trachomatis

In tests on 375 genital tract specimens a commercially available enzyme immunoassay for Chlamydia trachomatis (IDEIA; Boots-Celltech) was found to have sensitivity values of 62% for men and 74% for women, and a specificity of 97% for both groups, relative to the results obtained by a fluorescence assay (Micro Trak; Syva). The positive predictive value and the negative predictive value of the immunoassay were 91% and 87%, respectively. Collection of samples for IDEIA in transport medium in plastic phials, as opposed to glass phials recommended by the manufacturer, had no effect on these values. Tests of the sensitivity of IDEIA using laboratory strains of C trachomatis showed that the assay detected chlamydial elementary bodies only at dilutions at least 10-fold lower than those at which they could be detected by Micro Trak. Tests of the specificity of the assay with microorganisms found in the genital tract, other than chlamydiae, showed that reactions occurred with a number of these. Testing three cervical swabs from the same patient, with the material taken into a single phial of transport medium, increased the sensitivity of IDEIA from 74% to 96%, without reducing the specificity which remained at 97%. It is concluded that this approach enchances the value of the test in a sexually transmitted disease clinic population and may do so in a population with a low prevalence of chlamydiae.

Elevated recombination rates in transcriptionally active DNA

We have examined the effect of RNA polymerase II-dependent transcription on recombination between directly repeated sequences of the GAL10 gene in S. cerevisiae. Direct repeat recombination leading either to plasmid loss or conversion was examined in isogenic strains containing null mutations in the positive activator, GAL4, or the repressor, GAL80. A 15-fold increase in the rate of plasmid loss is observed in cells constitutively expressing the construct compared with cells that are not. Conversion events that retain the integrated plasmid are not stimulated by expression of the repeats. Northern analysis of strains containing plasmid inserts with various promoter mutations suggests that the stimulation in recombination is mediated by events initiating within the integrated plasmid sequences.

The role of Chlamydia trachomatis in chronic abacterial prostatitis: a study using ultrasound guided biopsy

We studied 50 patients with chronic abacterial prostatitis as defined by the Stamey procedure via transrectal prostatic ultrasound and subsequent transperineal biopsy of the abnormal areas of the prostate to ascertain the role of Chlamydia trachomatis organisms (chlamydiae) in this condition. Chlamydiae were detected by an immunofluorescence technique in the urethra of 1 patient (2 per cent) but they were not recovered in McCoy cell culture from the prostatic tissue of any patient nor were they detected in the tissue by immunofluorescence. In addition, serum antibody to Chlamydia trachomatis was not found even in moderate titer. The approach in this study has overcome the problem of urethral contamination in the assessment of prostatic specimens from patients with chronic abacterial prostatitis. There is no evidence that chlamydiae are directly implicated in the disease, although the possibility of an earlier active role cannot be excluded.

Leaf senescence in a non-yellowing mutant of Festuca pratensis: Proteins of photosystem II

The senescence of leaves is characterized by yellowing as chlorophyll pigments are degraded. Proteins of the chloroplasts also decline during this phase of development. There exists a non-yellowing mutant genotype of Festuca pratensis Huds. which does not suffer a loss of chlorophyll during senescence. The fate of chloroplast membrane proteins was studied in mutant and wild-type plants by immune blotting and immuno-electron microscopy. Intrinsic proteins of photosystem II, exemplified by the light-harvesting chlorophyll a/b-binding protein (LHCP-2) and D1, were shown to be unusually stable in the mutant during senescence, whereas the extrinsic 33-kilodalton protein of the oxygen-evolving complex was equally lable in both genotypes. An ultrastructural study revealed that while the intrinsic proteins remained in the internal membranes of the chloroplasts, they ceased to display the heterogenous lateral distribution within the lamellae which was characteristic of nonsenescent chloroplasts. These observations are discussed in the light of possible mechanisms of protein turnover in chloroplasts.

Acute epididymitis: a microbiological and ultrasonographic study

In a prospective study of 24 men (mean age 28.3 years) with acute epididymitis who underwent epididymal aspiration, micro-organisms were detected in 15 (62.5%). Chlamydia trachomatis accounted for 10 (42%) of the cases, being located in both the urethra and epididymis in 5 individuals. Chlamydial serology supported the diagnosis of chlamydial infection, there being a strong correlation between the detection of C. trachomatis and elevated titres of both chlamydial IgG and IgM antibodies. In 4 patients (mean age 55.5 years), Escherichia coli was cultured from both mid-stream urine and epididymal aspirate. Transrectal ultrasound revealed abnormal prostatic scans in 19 patients (79%). These data confirm the aetiological role of C. trachomatis, support the notion that micro-organisms spread intra-canalicularly and suggest that the prostate is also involved in the inflammatory process in acute epididymitis.

Lack of effect of selenium on induction of tumors of esophagus and bladder in rats by two nitrosamines

The effect of differences in level of dietary selenium on the induction of esophageal and bladder tumors in rats by two nitrosamines was investigated. Groups of 20 female F344 rats were given a synthetic diet containing less than 0.05 ppm Se to which selenium (as sodium selenite) was added at the concentration of 0.35, 0.7, 1.4 and 2.1 ppm selenium. These four groups, plus one without added Se, were treated with 20 ml per rat per day, 5 days a week, of a solution of nitrosomethylcyclohexylamine containing 5 mg/liter. A parallel five groups were treated in the same way with a solution of nitrosomethyl-3-carboxypropylamine in drinking water containing 600 mg per liter, as drinking water. Treatment lasted 28 weeks, at which time some animals had developed tumors. A group of 20 rats fed 0, 1.4 and 2.1 ppm Se was not treated with carcinogen. Rats consuming 1.4 ppm or 2.1 ppm Se gained weight more slowly than other groups. There was no significant difference in survival between the five groups treated with each carcinogen but receiving different dietary levels of selenium. Neither was there any significant difference between groups receiving each carcinogen in the incidence of tumors of the esophagus induced by nitrosomethylcyclohexylamine or of tumors of the urinary bladder induced by nitrosomethylcarboxypropylamine. Control rats on the synthetic diets did not survive as well as untreated rats eating regular chow diet. In these conditions there was no effect of dietary selenium levels on the induction of tumors in female rats by the two carcinogenic nitrosamines we used.

DNA alkylation by nitrosobis-(2-oxopropyl)amine in rats of different ages

We have examined the methylation of liver DNA (O6- and N7-methylguanine) by nitrosobis-(2-oxopropyl)amine (BOP) in male and female rats at various ages, following treatment with 2.5 mg of BOP; this dose given twice weekly for 30 weeks induces tumors in all animals. Except in young rats there was more methylation in female rat liver than in male rat liver, when adjusted for different sizes of the animals. There were differences in the extent of methylation between young (4 weeks) and older rats, but not between young adult (20 weeks) and old adult (65 weeks) males; the latter developed liver tumors when treated with BOP, and the former did not. There was no obvious relation between increased susceptibility to liver tumor induction by BOP and the extent of alkylation of liver DNA. Methylation of DNA was lower in the kidney than in the liver and, here, there was little difference between the sexes. In the testis there was N7-methylation of guanine in DNA, but no O6-methylguanine was detected.

Longitudinal study of the body composition of weight gain in exclusively breast-fed and intake-measured whey-based formula-fed infants to age 3 months

Body composition and the composition of weight gain in 82 healthy infants during the first 3 months of life were measured in relation to the type of feeding and nutrient intakes by serial measurements of total body potassium (TBK), anthropometry, and formula intake. Infants were exclusively fed either breast milk (n = 34, B fed) or whey-based formula (n = 48, F fed). Formula intakes were substantially lower than WHO-FAO recommendations (although serial weights paralleled standards), and were significantly greater in male infants, who had greater gains in weight and lean tissue than females. In both sexes, tissues low in K (fat and extracellular water) were added faster to the body weight than lean tissue. Overall, compared with B fed infants, F fed infants gained less weight between birth and 10 days and more weight between 10 and 90 days, although mean actual weights at 90 days were similar; formula feeding caused greater fat deposition in males and greater daily gains in lean mass in females. Differences in both quantity and quality of ingested nutrients account for these differences although the biological importance of these findings is speculative. These studies further elucidate the nature of growth in relation to modern feeding practices and the question of optimal versus maximal nutrient intake and growth in early life.

The Dana total shoulder arthroplasty

Fifty-six Dana unconstrained total shoulder arthroplasties in forty-seven patients were followed for a minimum of two years. The preoperative diagnoses included osteoarthritis, rheumatoid arthritis, traumatic arthritis, avascular necrosis, failed hemiarthroplasty, and failed total shoulder arthroplasty of another design. For all of the patients, the average rating for pain improved from 3 points preoperatively to 8 points postoperatively, and the average rating for function improved from 3 to 7 points. The ranges of abduction and of external rotation improved substantially in the shoulders that were affected by osteoarthritis, rheumatoid arthritis, or osteonecrosis. Ten patients were treated with a hooded glenoid component, designed to improve stability in shoulders in which the rotator cuff is deficient. In these shoulders, both the rating for pain and the rating for function improved, although the range of motion did not. Complications that required revision of the arthroplasty developed in five shoulders in which a regular component had been implanted and in two that had a hooded glenoid component. A radiolucent line developed at the bone-cement interface of the glenoid component in fifty-three shoulders, but only two revisions were done for loosening of the glenoid component.

Carcinogenesis by nitroso-2-hydroxyethylurea in splenectomized hamsters

Several nitrosoalkylureas tested for carcinogenic activity in Syrian hamsters have as their main effect the induction of hemangiosarcomas of the spleen, many of which appear to metastasize to the liver. To investigate whether any of these lesions in the liver might not be metastases, a group of female Syrian hamsters was surgically splenectomized and treated with nitroso-2-hydroxyethylurea (NHEU) dissolved in corn oil/ethyl acetate once a week for 22 weeks. The animals survived much longer (median 45 weeks) than a comparable group of unsplenectomized female hamsters given identical treatment (median 24 weeks). The absence of hemangiosarcomas of the liver in the splenectomized hamsters showed that the presumed metastases seen in intact animals were, in fact, just that. A second interesting conclusion is that the compound did not produce a concomitant increase in tumors of other types.

Inflammatory joint disease and human immunodeficiency virus infection

Nine men positive for antibody to human immunodeficiency virus (HIV) who developed peripheral, non-erosive arthritis were followed up. The clinical features were compatible with reactive arthritis but were atypical in several respects: the joint symptoms were generally severe, persistent, and unresponsive to non-steroidal anti-inflammatory drugs. The onset of arthritis was associated with various infections, none of which are known to be associated with the development of reactive arthritis. HLA typing was performed for three patients, all of whom were positive for HLA-B27. HIV was isolated from the synovial fluid of one patient. No patient had AIDS before developing arthritis, but four progressed to having AIDS after a mean of 7.5 months, and two died. Arthritis resolved in only one patient. The possibility of HIV infection should be considered in all patients with conditions suggesting reactive arthritis. Synovitis in patients with severe immunodeficiency has important pathogenetic implications.

Evidence that Chlamydia trachomatis causes seronegative arthritis in women

Chlamydia trachomatis elementary bodies (EBs) were found in synovial membranes or synovial fluid cell deposits from five of 15 women with seronegative mono- or oligoarthritis by means of a fluorescein conjugated anti-chlamydial monoclonal antibody (Micro Trak; Syva). Genital tract specimens were taken from only five of the patients, one of whom had intra-articular EBs, but none was chlamydia positive. Six of 10 patients tested were HLA-B27 positive, and chlamydial IgG antibody, measured by microimmunofluorescence, was present at a titre of 1/greater than or equal to 64 in the sera of five of the 15 patients, three of the five having EBs in their joints. In contrast, chlamydial EBs were not detected in the joints of a control group of 10 other women, most of whom had rheumatoid arthritis. None of them was HLA-B27 positive, and only one had a chlamydial antibody titre of 1/greater than or equal to 64. Neither Mycoplasma hominis nor ureaplasmas were isolated from the synovial fluids of seven patients and five controls who were tested. Antibody to M genitalium, however, was detected in five of the 10 patients but in none of the controls. This evidence apart, there was no other suggest that mycoplasmas or ureaplasmas might be responsible for arthritis which could not be attributed to chlamydiae.

Alkylation of DNA in rats by N-nitrosomethyl-(2-hydroxyethyl)amine: dose response and persistence of the alkylated lesions in vivo

The in vivo alkylation of DNA by N-nitrosomethyl-(2-hydroxyethyl)amine (NMHEA) was examined in male and female F-344/N rats. NMHEA is a strong hepatocarcinogen in female rats when administered by gavage but a weaker hepatocarcinogen in male rats. Groups of 5 rats of each sex were treated by gavage with various doses of NMHEA dissolved in corn oil. After 4 h the animals were sacrificed and the livers, lungs, and kidneys were removed. The DNA from each liver was isolated and the neutral thermal and mild acid hydrolysates were separated by high-performance liquid chromatography. The alkylated guanines were quantified by fluorescence spectroscopy. NMHEA gives rise to four fluorescent alkylated guanines, 7- and O6-methylguanines, and 7- and O6-hydroxyethylguanines. The dose-response data revealed that all four lesions increased with dose. There was approximately 10x more methylation than hydroxyethylation at the 7 position of guanine. There was less O6 alkylation, but both methylation and hydroxyethylation were observed at all of the doses studied. The overall alkylation was the same in males and females at the 10- and 20-mg/kg doses, but at higher doses the females exhibited significantly higher levels of alkylation than males. The level of alkylation of DNA isolated from non-target tissues, lung, and kidney was low. The persistence of these lesions in vivo was studied at a dose of 25 mg/kg. Groups of five animals each were sacrificed at various times from 0 to 96 h. There was no significant difference between the sexes in persistence of any of the lesions in the liver. The 7-alkylguanines disappeared slowly over the observation period. 7-Methylguanine was present at 30% of the maximum level after 96 h, while 7-hydroxyethylguanine appeared to be more stable. The O6-alkylguanines were removed rapidly from the liver, being at base level by 48 h. The rapid removal of O6-hydroxyethylguanine suggests a repair process independent of O6-alkylguanine-DNA guanine alkyl transferase: an excision repair is postulated. In vitro alkylation of calf thymus DNA by N-nitrosomethyl-(2-tosyloxyethyl)amine, a surrogate for the putative O-sulfate conjugate of NMHEA, resulted in exclusive methylation of DNA-guanine at both the 7 and O6 positions; no hydroxyethylation was detected. In vitro alkylation of calf thymus DNA with 2-hydroxyethyl-ethylnitrosourea resulted in exclusive hydroxyethylation of DNA-guanine at the 7 and O6 positions.(ABSTRACT TRUNCATED AT 400 WORDS)

The induction of bladder tumors in F344 rats by intravesicular administration of some nitrosamines

Three nitrosamines, metabolically related and formed in vivo from the bladder carcinogen nitrosomethyl-n-octylamine, were administered to groups of 12 female F344 rats by intraurethral instillation twice a week for 30 weeks. All three compounds induced tumors in the urinary bladder. Nitrosomethyl-2-oxopropylamine at 10 mg/ml was the most potent, causing death of half of the animals with tumors at 43 weeks, following a total dose of 1.0 mmol; most of the rats also had tumors of the nasal mucosa, and there were some tumors of the kidney and kidney pelvis. Nitrosomethyl-2-hydroxypropylamine at 10 mg/ml (total dose 1.0 mmol) was much less effective, the median week of death being 83 weeks. In addition to bladder tumors, this group had tumors of the nasal mucosa, esophagus, and kidney. Nitrosomethyl-3-carboxypropylamine at 75 mg/ml and a total dose of 6.2 mmol per rat induced a high incidence of bladder tumors and tumors of the kidney pelvis, but not tumors of the nasal mucosa; the median week of death for this group was 55 weeks. It is concluded that nitrosomethyl-n-alkylamines that induce bladder tumors by oral administration to rats are metabolized to nitrosomethyl-3-carboxypropylamine, which is excreted in the urine and further metabolized to nitrosomethyl-2-oxopropylamine, the proximate bladder carcinogen.

The use of postoperative irradiation for the prevention of heterotopic bone formation after total hip replacement

Formation of heterotopic bone (HTB) following total hip replacement may partially or completely ankylose the joint space, causing pain and/or limiting the range of motion. Patients at high risk for formation of HTB postoperatively include those with previous HTB formation, heterotopic osteoarthritis, and active rheumatoid spondylitis. Patients in these high risk groups have a 63-69% incidence of post-operative HTB formation, usually seen radiographically by 2 months post-operation. From 1980-1986 twenty-nine hips in 28 consecutively treated patients were irradiated post-operatively at the UCLA Center for the Health Sciences. The indication for irradiation was documented HTB formation previously in 26 of the 27 hips presented below. From 1980-1982 patients received 20 Gray (Gy) in 2 Gy fractions; from 1982-1986 the dose was reduced to 10 Gy in 2 Gy fractions. Twenty-seven hips in 26 patients completed therapy and were available for evaluation, with a minimum of 2 month follow-up, and a median follow-up of 12 months. Three of 27 hips developed significant HTB (Brooker grade III or IV) post-operatively, whereas 5 of 27 hips developed minor, nonsymptomatic HTB (Brooker grade I). When irradiation was begun by postoperative day 4, 0 of 17 hips formed significant HTB. If irradiation began after post-operative day 4, 3 of 10 hips formed significant HTB (Brooker grade III or IV). These 3 hips received doses of 10 Gy in one hip and 20 Gy in the other 2 hips. There were no differences in the incidence or severity of side effects in the 10 Gy vs. the 20 Gy treatment groups. Eighteen hips received 10 Gy, 8 hips 20 Gy and, 1 hip 12 Gy. In conclusion, 10 Gy in 5 fractions appears as effective as 20 Gy in 10 fractions at preventing post-operative formation of HTB. For optimal results, treatment should begin as early as possible prior to post-operative day 4.

The enigma of non-gonococcal urethritis: role for Bacteroides ureolyticus

Although up to about half the cases of acute non-gonococcal urethritis (NGU) are caused by Chlamydia trachomatis organisms (chlamydiae) and a smaller, ill-defined, proportion probably by Ureaplasma urealyticum organisms (ureaplasmas), the aetiology of all cases is not understood. Clarification of the role of the anaerobe, Bacteroides ureolyticus, was sought in the current study. Seventy five chlamydia negative patients with NGU were treated on a double blind placebo controlled basis with metronidazole. After seven days more of the 35 patients given this drug tended to improve clinically than the 40 given the placebo, but the difference was not significant. Of 23 chlamydia negative but anaerobe positive men, however, 78% (7/9) receiving metronidazole responded clinically, but only 7% (1/14) receiving placebo responded (p less than 0.001). Furthermore, whereas 78% of the anaerobe positive men given metronidazole recovered, only 23% (6/26) of the anaerobe negative men did so (p less than 0.02). No further evidence for the role of ureaplasmas in the aetiology of NGU was obtained, but the data suggest that B ureolyticus organisms, and perhaps other anaerobes, have an important role in a small proportion of cases and that the beneficial effects of metronidazole given on an empirical basis will be confined to anaerobe positive urethritis.

Effects of feminization of male F344 rats on induction of tumors and on nucleic acid alkylation by nitrosobis-(2-oxopropyl)amine

Groups of male and female F344 rats were treated twice weekly by gavage with 2.5 mg of nitrosobis-(2-oxopropyl)amine (BOP) for 35 weeks. Additional groups given the same treatment were male rats castrated at birth, male rats bearing an implant of a pellet containing estradiol and castrated male rats bearing an estradiol pellet. Most rats died with tumors related to the treatment; intact male rats survived the least well of the five groups. Most rats in all groups had alveolar/bronchiolar neoplasms of the lung. Many of the male rats also had follicular cell neoplasms of the thyroid and transitional cell neoplasms of the urinary bladder and kidney pelvis; there were no liver tumors in intact male rats. Almost all female rats and castrated male rats had liver neoplasms, including hepatocellular, cholangiocellular and hemangiosarcomatous neoplasms, but few neoplasms of the thyroid, kidney or bladder. The male rats feminized with estradiol, intact or castrated, had liver neoplasms, mainly cholangiocellular, and also neoplasms of the thyroid. Two rats of each of the five groups were treated at 20 weeks of age with [14C]BOP. As measured by respiration of 14CO2, metabolism of BOP was faster in the two groups of male rats with the estradiol implant than in the other groups. DNA and RNA of the liver were isolated 6 h after treatment. The extent of methylation of liver DNA as 7-methylguanine and O6-methylguanine was higher in the females and in the feminized males than in the intact male rats, but when normalized to the dose of nitrosamine per unit body weight there was little difference among the five groups.

A simple method for the detection of Chlamydia trachomatis infections in general practice

Chlamydial infection is an important cause of genital tract disease in women and is often silent. Collection, storage and transportation of specimens required for culture pose problems which have made studies difficult and diagnosis impractical outside hospitals or sexually transmitted disease clinics.The direct monoclonal antibody test (MicroTrak, Syva) for detecting chlamydiae is comparable with the traditional culture method in sensitivity and specificity. The test requires only the preparation of a smear on a slide, making it convenient for use in general practice. The feasibility of using this procedure in an inner city practice was demonstrated in tests on 188 women who required pelvic examination. Of 169 women from whom valid specimens were obtained 18 (10.7%) were found to have a chlamydial infection. Only three of the infected women were asymptomatic and the organisms were associated particularly with dysuria. The value of the test in comparison with other procedures currently available for detecting chlamydiae is emphasized.

Tumors in F344 rats by oral administration of 1,3-diethyltriazene

A group of 20 male F344 rats was given by gavage a solution of 2.5 mg of 1,3-diethyltriazene in 0.2 ml corn oil twice a week for 20 weeks. Diethyltriazene is very unstable in hydroxylic solvents, but when administered in oil by gavage it induced tumors in almost all of the treated animals, 16 of which had neoplasms of the forestomach; 13 of which were carcinomas. In addition 9 rats had adenomas of the nasal mucosa, two had alveolar-bronchiolar adenomas of the lung, one had a carcinoma of the esophagus and one an adenocarcinoma of the ileum. Half of the rats had died by week 56 of the experiment, the first at week 40 and the last at week 73. The induction of tumors at sites distant from the stomach indicate that diethyltriazene is more stable in the body than would be predicted from its chemical behavior. Although diethyltriazene is a protected alkyldiazonium ion, its carcinogenic effects in rats differ from ethylnitrosoureas, which are also ethylating agents.

Evaluation of enzyme immunoassay (Chlamydiazyme) for detecting Chlamydia trachomatis in genital tract specimens

An enzyme immunoassay (Chlamydiazyme) for detecting Chlamydia trachomatis was evaluated on genital specimens from 96 men and 272 women attending a clinic for sexually transmitted diseases (STD clinic). Compared with a direct immunofluorescence test for chlamydial elementary bodies, the enzyme immunoassay had a sensitivity of 58% on specimens from men, a specificity of 90%, a positive predictive value of 93%, and a negative predictive value of 88%; the assay had a sensitivity of 67% on specimens from women, a specificity of 89%, a positive predictive value of 63% and a negative predictive value of 90%. Immunofluorescence provided the most stringent test for the performance of the enzyme immunoassay as values were improved a little when a cell culture procedure was used for comparison. Further evidence for the lack of sensitivity was the detection of elementary bodies, sometimes in large numbers, in the enzyme immunoassay buffer of 13 of 19 specimens that had given a negative enzyme immunoassay result and the finding in comparative titrations of four laboratory strains that the enzyme immunoassay was at least 100-fold less able to detect chlamydiae than either immunofluorescence or the cell culture procedure. Lack of specificity may be associated with the finding that the enzyme immunoassay antibody reacted with strains of Acinetobacter calcoaceticus, Escherichia coli, Gardnerella vaginalis, Neisseria gonorrhoeae and group B streptococci. The enzyme immunoassay was not considered to be sufficiently sensitive, specific, or reproducible for routine use.

Nutritional rehabilitation in cystic fibrosis: controlled studies of effects on nutritional growth retardation, body protein turnover, and course of pulmonary disease

The effects of a sustained increase in energy and protein intake on weight gain, growth, body protein metabolism, and the course of pulmonary disease were studied in 10 undernourished patients with cystic fibrosis unable to maintain nutrition and growth by the oral route and with declining nutritional and pulmonary status in the year prior to study. A 1-year course of nutrient supplementation using a semielemental high-nitrogen formula was delivered by nocturnal intragastric feeding or as an orally administered supplement; progress was compared with that of 14 height-, sex- and FEV1-matched patients with cystic fibrosis receiving conventional therapy. Supplementation resulted in a catch-up weight gain and sustained improvement in linear growth, with fewer pulmonary infections per year than during the initial observation period. Better weight gain and linear growth than in the comparison group were observed, as well as a significant reversal of the trend for deteriorating lung function. Compared with data from healthy children, 15N-glycine kinetics demonstrated increased protein breakdown and negligible net protein deposition in the treatment group prior to supplementation. After supplementation, synthesis in excess of breakdown, with net protein accretion, occurred by 1 month of supplementation. By 6 to 12 months a significant reduction in the previously high rate of mean synthesis and breakdown was observed, with maintenance of net anabolism. These dynamic changes in whole-body protein turnover reflect a long-term improvement in energy and protein intake, which can favorably affect nutrition, growth, and the course of pulmonary disease in problem cases of cystic fibrosis.

Microbiological survey of acute epididymitis

In an 18 month period, 198 men presented with a painful, swollen, and tender epididymis or testicular or scrotal pain. Fifty were excluded from analysis because of prior antibiotic treatment or a history of the disease, or both. Of the remaining patients, epididymitis was not diagnosed in 108, though 23 (21%) of them had urethritis. Thus 40 men were seen who had acute unilateral epididymitis. Of the 27 less than 35 years old, 13 (48%) had a urethral chlamydial infection and two others a gonococcal infection. Sexually transmitted micro-organisms were not confined, however, to the younger age group, though only two (15%) of 13 men who were 35 years or older had a urethral chlamydial infection. Most, that is 29 (73%), of the patients with acute epididymitis also had urethritis when first seen. Urethral micro-organisms were found most often in 13 men who had severe epididymitis, chlamydial infection occurring in eight (62%) of the patients in this category.

The CAD hip arthroplasty. Five to ten-year follow-up

One hundred and fourteen total hip arthroplasties in 100 patients were performed using the CAD (computer-assisted design) prosthesis at The Hospital for Special Surgery between 1975 and 1977. Sixty-one of these patients (seventy-four hips) have been followed both clinically and radiographically for a minimum of five years (average, 7.1 years). While no hip required revision before five years, seven hips were revised between six and ten years postoperatively. Ten hips had an excellent result; forty-eight, good; eight, fair; and one, poor. Radiographic analysis revealed narrowing of the cortex of the bone medially at the region of the proximal part of the stem in the hips that were operated on as compared with the contralateral side that was not operated on. Nine hips (12 per cent) had one to two-millimeter radiolucent lines at the femoral bone-cement interface, and in five the lines were progressive. Fourteen hips (19 per cent) had radiolucent lines at the femoral bone-cement interface with a maximum width of 0.5 millimeter. Thirty-four (42 per cent) had more than three millimeters of resorption of the calcar or superomedial cyst formation. Survivorship analysis of the prosthesis predicted a 77 per cent survival rate at nine years. None of the prosthetic stems fractured despite the fact that the population was young, active, heavy, and predominantly male. The incidence of calcar resorption, however, was higher than in other studies. Thus, while the revision rate compared favorably with that of similar studies using other stem designs, compromise of the bone stock of the proximal end of the femur may be a significant disadvantage of this type of prosthesis.

Chronic lead nephropathy in Queensland: alternative methods of diagnosis

Indices of past lead absorption were measured and compared in patients with chronic renal failure from many causes, including some with chronic lead nephropathy. X-ray fluorescence (XRF) yielded finger bone lead concentrations by a new in vivo method. These correlated significantly with excess urinary lead following calcium di-sodium EDTA (ethylenediamine tetra-acetate) and erythrocyte lead concentration. Discriminant function analysis demonstrated that the patients in the study could be separated into two groups without any reference to the EDTA lead excretion test using the following variables, all of which contributed significantly to the discrimination. In order of importance, these were: a childhood history of acute lead poisoning, a history of gout, a family history of gout and detectable XRF finger bone lead. Although the XRF finger bone lead measurement is convenient and non-invasive, its lack of sensitivity (48%) limits its usefulness as a screening test for chronic lead nephropathy.

The Micro Trak test for rapid detection of chlamydiae in diagnosing and managing women with abdominal pain

Using a fluorescein labelled monoclonal antibody ("Micro Trak") to identify chlamydia elementary bodies in endocervical smears, we detected Chlamydia trachomatis in 31 (21%) of 150 cases of classic pelvic inflammatory diseases (PID) and in 42 (18%) of 232 cases of abdominal pain not diagnosed as PID. Only 43 (59%) of the women yielding chlamydiae would have received treatment in the absence of a diagnostic service for chlamydial infection. Evidence of chlamydial infection should be sought in all women presenting to a sexually transmitted disease (STD) clinic with abdominal pain.

Rapid, reliable diagnosis of chlamydial ophthalmia by means of monoclonal antibodies

The use of fluorescein-conjugated monoclonal antibody (Syva, UK) provided a rapid reliable diagnostic test for Chlamydia trachomatis in conjunctival samples from 100 adults with acute follicular conjunctivitis and seven babies with suspected chlamydial ophthalmia neonatorum. Elementary bodies (EBs) were seen in smears from 11 of the adults, and culture confirmed C. trachomatis infection in nine of them. Both tests were positive with specimens from four of the neonates. No specimens from either group of patients produced a negative result in the smear test but a positive result by culture. However, the two adult patients with chlamydial ophthalmia who had negative cultures but were EB-positive had both had prior topical tetracycline therapy.