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Biomedical subjects

B J Thomas

Publications and source records attributed to B J Thomas.

At least 163 records · Page 9Linked to original sources
PubMed1986

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.

Abdomen↗
PubMed1986

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.

Acute Disease↗
PubMed1986

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.

Adult↗
PubMed1985

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.

Adult↗
PubMed1985

Investigation into the value of Papanicolaou stained cervical smears for the diagnosis of chlamydial cervical infection.

Forty five (37%) of 121 female contacts of men with non-gonococcal urethritis or gonorrhoea were chlamydia positive, as judged by isolation or by detecting elementary bodies in smears with a fluorescein labelled chlamydial monoclonal antibody. Only six (13%) of these, however, had Papanicolaou stained smears in which there were inclusion like changes suggestive of chlamydial infection. Furthermore, of 15 patients who had such cytological changes, chlamydiae were detected in only six and the abnormalities were found also in Papanicolaou stained smears from 10 (13%) of the 76 chlamydia negative patients. Modifying the Papanicolaou stained smears by including endocervical material did not increase sensitivity. In addition, destaining and restaining them with the monoclonal antibody was time consuming and the results were unreliable. The staining of cervical smears with Papanicolaou reagent is a technique of low sensitivity and specificity for diagnosing or screening for chlamydial cervical infection and cannot be recommended.

Cervix Mucus↗
PubMed1985

A case report of alprazolam-induced stuttering.

A case is presented in which, by a double-blind, placebo-controlled trial, alprazolam was shown to produce reversible stuttering. Because this effect has been associated with tricyclic antidepressants but not benzodiazepines, the case provides further evidence for pharmacologic effects similar to tricyclic antidepressants.

Adult↗
PubMed1985

Results of the administration of diphosphonate for the prevention of heterotopic ossification after total hip arthroplasty.

We evaluated the results in 177 patients with 200 total hip arthroplasties that had been performed for primary osteoarthritis. Severe postoperative heterotopic-bone formation (grades III and IV according to the classification of Brooker et al.) was found in thirty-six hips (18 per cent). The incidence of heterotopic bone formation was found to be slightly higher in the patients who had received diphosphonate than in the control group of patients who had received either a placebo or no drug therapy. The postoperative range of motion of the hips as well as ratings for pain, walking, and function did not differ significantly between the treated and untreated groups. The results of this study were consistent with those of previously published reports that demonstrated that while diphosphonates did not prevent heterotopic bone formation in laboratory animals they did result in a delay of mineralization of osteoid. This delay did not, as was hoped, significantly improve the range of motion of the involved hips in our series.

Clinical Trials as Topic↗
PubMed1984

Regulation of pyruvate oxidation in blowfly flight muscle mitochondria: requirement for ADP.

Blowfly (Phormia regina) flight muscle mitochondria oxidized pyruvate ( + proline) in the presence of either ADP (coupled respiration) or carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP-uncoupled respiration). There was an absolute requirement for ADP (Km = 8.0 microM) when pyruvate oxidation was stimulated by FCCP in the presence of oligomycin. This requirement for ADP was limited to the oxidation of pyruvate; uncoupled alpha-glycerolphosphate oxidation proceeded maximally even in the absence of added ADP. Atractylate inhibited uncoupled pyruvate oxidation whether added before (greater than 99%) or after (95%) initiation of respiration with FCCP. In the presence of FCCP, oligomycin, and limiting concentrations of ADP (less than 110 microM), there was a shutoff in the uptake of oxygen. This inhibition of respiration was completely reversed by the addition of more ADP. Plots of net oxygen uptake as a function of the limiting ADP concentration were linear; the observed ADP/O ratio was 0.22 +/- 0.025. An ADP/O ratio of 0.2 was predicted if phosphorylation occurred only at the succinyl-CoA synthetase step of the tricarboxylate cycle. Experiments performed in the presence of limiting concentrations of ADP, and designed to monitor changes in the mitochondrial content of ADP and ATP, demonstrated that the shutoff in oxygen uptake was not due to the presence of a high intramitochondrial concentration of ATP. Indeed, ATP, added to the medium prior to the addition of FCCP, inhibited uncoupled pyruvate oxidation; the apparent KI was 0.8 mM. These results are consistent with the hypothesis that it is the intramitochondrial ATP/ADP ratio that is one of the controlling factors in determining the rate of flux through the tricarboxylate cycle. Changes in the mitochondrial content of citrate, isocitrate, alpha-ketoglutarate, and malate during uncoupled pyruvate oxidation in the presence of a limiting concentration of ADP were consistent with the hypothesis that the mitochondrial NAD + -linked isocitric dehydrogenase is a major site for such control through the tricarboxylate cycle.

Adenosine Diphosphate↗
PubMed1984

Calcium inhibition of the NAD+-linked isocitrate dehydrogenase from blowfly flight muscle mitochondria.

Free Ca2+ was shown to inhibit the NAD+-isocitrate dehydrogenase from blowfly flight muscle mitochondria. Inhibition by free Ca2+ concentrations of 40 microM or greater was found in the absence or presence of ADP and citrate, two known activators of the enzyme. Calcium decreased the affinity of the enzyme for its substrate, the magnesium DL-isocitrate chelate; no change in the apparent V of the reaction was observed. Calcium was inhibitory when activity was measured in the presence of fixed concentrations of magnesium DL-isocitrate chelate in the presence of several fixed concentrations of either free isocitrate3-, an activator, or free Mg2+, an inhibitor of the enzyme. That NAD+-isocitrate dehydrogenase from blowfly flight muscle mitochondria was not activated by micromolar free Ca2+ is consistent with the view that calcium does not play a role in regulating the flux through the tricarboxylate cycle in this species.

Adenosine Diphosphate↗
PubMed1984

Purification and properties of thiol beta-lactamase. A mutant of pBR322 beta-lactamase in which the active site serine has been replaced with cysteine.

The specifically mutated enzyme thiol beta-lactamase has been expressed in Escherichia coli by means of the trp promoter and purified to homogeneity. The gene for this enzyme results from a single base change N410 A----T in the gene of pBR322 RTEM beta-lactamase (EC 3.5.2.6, penicillinase, penicillin amido-beta-lactamhydrolase) which alters the codon for the active site Ser 70 to that for Cys. Precursor thiol beta-lactamase is processed to give the same NH2-terminal sequence as that for wild type enzyme. In contrast to the wild type enzyme, thiol beta-lactamase contains one free titratable thiol group/molecule. Thiol beta-lactamase catalyzes the hydrolysis of beta-lactams with a substrate specificity that is distinct from that of wild type enzyme. For benzyl-penicillin and ampicillin, the Km values are similar to wild type values although the kcat values are 1-2% that of wild type enzyme. For the cephalosporin nitrocefin, the Km is greater than 10-fold that of the wild type and the kcat is at least as large as the kcat for the wild type enzyme. Thiol beta-lactamase is different from wild type beta-lactamase in that it is not competitively inhibited by boric acid although a small degree of noncompetitive inhibition does occur. Whereas the circular dichroism spectra of both enzymes are nearly identical, thiol beta-lactamase at 40 degrees C is 3-fold more resistant to trypsin than is the wild type enzyme.

Amino Acid Sequence↗
PubMed1984

Chronic renal failure with gout: a marker of chronic lead poisoning.

EDTA (calcium disodium edetate) lead mobilization and x-ray fluorescence (XRF) finger bone lead tests were done in 42 patients with chronic renal failure and without persisting lead intoxication. Nineteen of 23 patients with gout and 8 of 19 without gout had positive EDTA lead mobilization tests. Those patients with gout excreted significantly more excess lead chelate than those without gout. In the gout group 17 patients denied any childhood or industrial exposure to lead. They had a greater number of positive tests and excreted significantly more excess lead chelate than 14 patients with neither gout nor lead exposure. These results confirm that gout in the presence of chronic renal failure is a useful marker of chronic lead poisoning. Of 27 patients with positive lead mobilization tests, only 13 had elevated XRF finger bone lead concentrations (sensitivity 48%). Three of 15 patients with negative lead mobilization tests had elevated XRF finger bone lead concentrations (specificity 80%). Although the XRF finger bone lead test is a convenient noninvasive addition to the diagnostic evaluation of patients with chronic renal failure and gout, its application is limited due to the lack of sensitivity of the method.

Aged↗
PubMed1984

Whole body cellular and collagen nitrogen in healthy and wasted man.

The classical literature shows that wasting of body protein takes place mainly from the cellular compartment leaving high proportions of extracellular collagen. Whole body nitrogen ( WBN ) is proportional to whole body protein (cellular + extracellular) while whole body potassium ( WBK ) is almost entirely intracellular. WBK might be an adequate index of cellular wasting. WBN was measured by neutron activation and WBK by counting 40K in 29 healthy males and 131 male and female patients with wide ranges of body composition. Our wasted patients with Crohn's disease or ulcerative colitis, had higher WBN / WBK ratios than matched healthy controls and the difference between the two groups was in the cellular ratio (23.6 mol of N/mol of K, 0.33 g of N/mmol of K, 3 mmol of K/g of N). A multiple regression model for all the subjects represented cellular nitrogen by a term in WBK and extracellular nitrogen by simple anthropometric measurements. The partial regression coefficient of WBN on WBK was 22.6 +/- 1.1 (SE) mol of N/mol of K; this was also similar to the cellular ratio. Our results were compatible with extracellular protein (mainly collagen, which is 35% of normal whole body protein) remaining resistant to wasting even when severe loss of cellular protein occurs. The high ratios of WBN / WBK in wasted patients can be explained by this disproportionate wasting of cellular substances and they do not imply alterations in the cellular N/K ratio. We suggested that the stable ratio of WBK to cellular protein makes it an effective index of cellular wasting. The resistance of collagen to wasting and the preponderance of extracellular mass in the fat-free mass of wasted subjects, make WBN and fat-free mass unreliable guides to the extent of wasting.

Activation Analysis↗
PubMed1984

Sensitivity of detecting Chlamydia trachomatis elementary bodies in smears by use of a fluorescein labelled monoclonal antibody: comparison with conventional chlamydial isolation.

Commercially produced fluorescein labelled monoclonal antibodies for the detection of Chlamydia trachomatis have recently become available. One is for detecting inclusions in cell culture (culture confirmation) and the other for detecting elementary bodies in smears from potentially infected sites. We have compared the two monoclonal antibodies with our routine isolation method, which utilises Giemsa staining of cycloheximide treated McCoy cell cultures. The culture confirmation system offered no advantages over Giemsa staining for the detection of inclusions in cell monolayers. By contrast, using monoclonal antibody to detect elementary bodies in smears was much quicker and simpler and slightly more sensitive than isolation of chlamydiae in cell culture. For specimens from seven babies with conjunctivitis and from 35 female contacts of men with non-gonococcal urethritis, there was complete agreement between the results of detecting inclusions in culture and those of seeking elementary bodies in smears. For samples from 100 men with non-gonococcal urethritis and from 100 men with gonorrhoea there was 99% and 94% agreement, respectively, between the results of the two tests. Other aspects and possible uses of the new detection system are discussed.

Antibodies, Monoclonal↗
PubMed1984

In vivo X-ray fluorescence estimation of bone lead concentrations in Queensland adults.

A group of 200 Queensland adults without known health problems had in-vivo estimation of finger bone lead concentrations using X-ray fluorescence analysis (XRF). Forty of these subjects had elevated levels of bone lead of 25 ppm or more, consistent with exposure to the metal. Although the correlation between Queensland residence during childhood and raised bone lead levels was not significant, there were significant correlations between childhood residence in a painted wooden house and raised levels, and between occupational exposure and raised levels. Of the 40 subjects with elevated lead levels only two had neither a history of occupational exposure or childhood residence in a wooden house, whereas 11 of the 25 who had a history of both occupational and residential exposure were positive. The data are consistent with lead in housepaint, or absorbed during occupational exposure, being the two major sources of raised bone lead concentrations.

Adult↗
PubMed1984

Treatment of primary osteoarthritis of the hip. A comparison of total joint and surface replacement arthroplasty.

Of 285 total hip arthroplasties (260 patients) performed for primary osteoarthritis during a six-year period, 135 were resurfaced using a Tharies prosthesis (total hip articular replacement with internal eccentric shells) and 150 were treated with the Trapezoidal-28 total hip replacement. From each of these two groups 100 hips (ninety-one patients in the Tharies group and eighty-six in the Trapezoidal-28 group) that had been followed for two to seven years were evaluated at the time of follow-up in accordance with a predetermined protocol. The patients were younger in the Tharies than in the Trapezoidal-28 group (average ages, fifty-eight and sixty-six years), included more men (sixty compared with thirty-five), and were more active postoperatively. The average follow-up was forty-seven months for the total joint-replacement group and thirty-eight months for the surface replacement group. At follow-up the ratings for pain, walking, and function according to the University of California at Los Angeles 10-point scale and the clinical results were identical in the two groups. Heterotopic ossification (Brooker grade III or IV) developed after thirteen Trapezoidal-28 and twenty-two Tharies arthroplasties. Radiographs made at six and twelve months and at final follow-up showed that the incidence of radiolucencies about the acetabular component was higher in the resurfacing group: fifty-seven with complete radiolucent lines after an average follow-up of thirty-eight months compared with thirty-six with complete lines after an average follow-up of forty-seven months. There were three failures in the joint-replacement group: a hematogenous staphylococcal deep infection that required a Girdlestone procedure, a femoral stem fracture that required revision, and loosening of an acetabular component for which revision was performed. There was also one dislocation, successfully treated by closed reduction. Similarly, in the resurfacing group there were three failures: two loose acetabular components, revised successfully, and one loose femoral component that necessitated total joint arthroplasty. Multivariate stepwise regression analysis showed that the factors that affected the final extent and width of the acetabular radiolucencies adversely after resurfacing were: any radiolucent lines that were visible at six months, a high level of physical activity after arthroplasty, and a thin superior cement mantle.(ABSTRACT TRUNCATED AT 400 WORDS)

Activities of Daily Living↗
PubMed1984

Congenital paraxial hemicorpectomy. A case report.

Although physicians may be familiar with terms such as "fibular paraxial hemiamelia," they often do not realize that the defects may involve more proximal levels than are first apparent. The following case report demonstrates a paraxial defect that begins at the level of T2 and extends the remainder of the body. No previous case has been reported, and because of the peculiar distribution of the anomaly, the situation has been termed "congenital paraxial hemicorpectomy."

Abnormalities, Multiple↗