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Biomedical subjects

B J Thomas

Publications and source records attributed to B J Thomas.

At least 19 recordsLinked to original sources
PubMed1992

Detection of Chlamydia trachomatis DNA in joints of reactive arthritis patients by polymerase chain reaction.

In 1986, Chlamydia trachomatis elementary bodies were found by direct immunofluorescence (DIF) in synovial-fluid cell deposits and synovial-membrane biopsy samples from five of eight patients with sexually acquired reactive arthritis (SARA) but in none of eight controls with other types of arthritis. Cells from the original slides (stored at 4 degrees C) have now been examined by a polymerase chain reaction (PCR) that amplifies DNA for the major outer membrane protein of C trachomatis. Chlamydial DNA was found in samples from four DIF-positive patients, one DIF-negative patient, and one DIF-negative control. Overall, there was 80% concordance for DIF and PCR results. This study supports our previous finding of chlamydiae in joints in reactive arthritis.

Adult↗
PubMed1992

Nutritional support in children with end-stage liver disease: a randomized crossover trial of a branched-chain amino acid supplement.

Malnutrition is common in children with end-stage liver disease (ESLD) awaiting orthotopic liver transplantation (OLT), and nutritional support is assuming an important role in preoperative management. To evaluate preoperative nutritional therapy, 19 children (median age 1.25 y) with ESLD awaiting OLT were prospectively studied. Two high-energy, isoenergetic and isonitrogenous nutritional formulations delivered nasogastrically were compared: a branched-chain amino acid (BCAA)-enriched semielemental formulation and a matched standard semielemental formation. Twelve of 19 patients completed a randomized controlled study before OLT and 10 of 19 completed a full crossover study. Improvements in weight and height occurred during the BCAA supplements, with no statistical change on the standard formulation. Significant increases in total body potassium, midupper arm circumference, and subscapular skinfold thickness occurred during the BCAA supplements, whereas no significant changes occurred during the standard formulation period. Significantly fewer albumin infusions were required during the BCAA supplement. These findings suggest that BCAA-enriched formulas have advantages over standard semielemental formulas in improving nutritional status in children with ESLD, and are deserving of wider application and study.

Albumins↗
PubMed1992

The nature of malnutrition in children with end-stage liver disease awaiting orthotopic liver transplantation.

To evaluate malnutrition in chronic liver disease, and its relationship to nutrient deficiencies and hepatic dysfunction, 27 children with end-stage liver disease were studied. Mean protein-energy intakes were 70% of recommended daily intakes. The patients were underweight and stunted with reduced mean triceps and subscapular skinfold thicknesses and midupper arm circumference. Mean total body potassium was only 63 +/- 18% of that expected for age and sex. Deficiency of essential fatty acids (32%), and low concentrations of fat-soluble vitamins (A, 92%; E, 32%), iron (32%), zinc (42%), and selenium (13%) were common. Serum ammonia concentrations were raised in all patients, and increased methionine, tyrosine, and glutamic acid, and reduced glutamine concentrations were noted. There was no correlation between the degree of malnutrition and the degree of liver synthetic function, the degree of cholestasis, or the degree of liver injury. We suggest that potentially correctable factors in addition to liver failure (eg, inadequate absorbed intake) were important determinants of malnutrition in these patients.

Amino Acids↗
PubMed1992

Systemic and local carcinogenesis by directly acting N-nitroso compounds given to rats by intravesicular administration.

A number of directly acting carcinogenic N-nitroso compounds were administered to female F344 rats intravesically, to assess their ability to induce tumors locally in the urinary bladder and systemically following absorption through the bladder mucosa. The compounds were alkylnitosoureas and alkylnitrosocarbamates and could be formed by interaction of amides with bacterially produced nitrite in infected bladders. Methylnitrosourethane was very toxic: doses of 1-2 mg caused death of some rats. A total dose of 0.15 mmol of ethylnitrosourethane, which was much less toxic, was administered to each rat and almost all developed bladder tumors. Ethylnitrosourea also gave rise to bladder tumors following intravesical treatment, and induced some tumors systemically, whereas methylnitrosourea, 2-methoxyethylnitrosourea and 2-hydroxypropylnitrosourea induced bladder tumors in high incidence and few tumors systemically. Nitrosooxazolidone was quite toxic and induced few bladder tumors. The dialkylnitrosoureas were more stable and some induced more tumors systemically than the monoalkylnitrosoureas. 1,3-Dimethylnitrosourea induced no bladder tumors and 1,3-diethylnitrosourea very few, but both induced tumors systemically that were similar to those induced by gavage treatment of rats. 1-Ethyl-1-nitroso-3-hydroxyethylurea, 1-hydroxyethyl-1-nitroso-3-ethylurea and 1-(2-hydroxypropyl)-1-nitroso-3-(2-chloroethyl)-urea induced bladder tumors in a majority of rats treated intravesically; the first induced many tumors systemically. Most of the bladder tumors were transitional cell papillomas and carcinomas, but there were a few squamous cell tumors, smooth muscle tumors, sarcomas and carcinosarcomas. The effects of intravesical administration of the directly acting alkylating compounds are compared with the effects of similar doses given to rats by gavage.

Administration, Intravesical↗
PubMed1992

The carcinogenic effect of methapyrilene combined with nitrosodiethylamine given to rats in low doses.

The carcinogenic effects of combinations of methapyrilene hydrochloride (MP), nitrosodiethylamine (NDEA), and phenobarbital (PB) or partial hepatectomy (PH) were examined following sequential treatment of rats. MP is a generally non-genotoxic liver carcinogen of moderate potency, NDEA is a genotoxic liver carcinogen, PB is primarily a liver tumor promoter and PH induces cell proliferation. The dose of each carcinogen was chosen to be below that causing significant liver tumor incidence when given singly. There were 12 protocols involving groups of 28 female rats each. Short treatments with NDEA and MP were followed by 60 weeks of PB promotion or by partial hepatectomy. Each treatment was given separately or in double combination as controls. Several animals of each group were killed at intervals during the experiment for examination of toxic effects and the presence of altered hepatic foci. In only 3 of 12 groups was there a significant incidence of rats with liver neoplasms: the two groups given three treatments: NDEA, MP and PB (86% tumors) or NDEA, MP and PH (33%), and the group receiving NDEA and MP without promotion (46%). The results clearly indicated a co-carcinogenic effect between NDEA and MP. Continuous PB potentiated tumor development, while PH did not. There was no evidence of liver toxicity from any of the treatments, but clear cell foci observed in three groups at weeks 13 and 33 correlated with the later development of liver neoplasms.

Adenoma↗
PubMed1992

Multi-frequency bioelectrical impedance augments the diagnosis and management of lymphoedema in post-mastectomy patients.

The value of multiple frequency bioelectric impedence analysis (MFBIA) in the monitoring and management of post-mastectomy lymphoedema of the arm was evaluated in 15 patients and controls. The technique was found to produce quantitative agreement with a clinical diagnosis of lymphoedema and with the currently-used measure (limb volume calculated from circumferential measurements) of limb size. The significance of this finding lies in MFBIA being diagnostically informative: it indicates when an observed change in limb volume is directly, albeit theoretically, attributable to accumulation of extracellular fluid. MFBIA potentially offers the means for earlier definitive diagnosis and more-accurate monitoring of extracellular fluid changes during and after treatment.

Adult↗
PubMed1992

British Diabetic Association's discussion paper on the role of 'diabetic' foods. Nutrition Subcommittee of the British Diabetic Association's Professional Advisory Committee.

1. Most diabetic foods provide slightly, but not substantially, less energy than comparable non-diabetic products. 2. Many diabetic foods have a higher fat content than their non-diabetic equivalents. This is contrary to the requirements of the 1984 Food Labelling Regulations. 3. Many diabetic products have a relatively high content of protein. 4. In percentage terms, the greatest difference between diabetic and non-diabetic foods remains that of carbohydrate content, particularly carbohydrate other than fructose or sorbitol. On a per portion basis (for instance, per teaspoon of jam) the difference is relatively small and likely to be of minimal practical significance. 5. Diabetic foods cost between 1.5 and 4 times as much as their non-diabetic equivalents. 6. Some ordinary reduced-sugar/low calorie products are preferable to diabetic products in terms of fat and energy content and cost. 7. The promotion and widespread availability of diabetic foods tend to delude patients into believing that these products are advantageous, or even necessary. Their existence also undermines current dietary teaching by implying that people with diabetes cannot eat normal foods. 8. Diabetic foods offer no significant physiological or psychological benefits to diabetic patients and can even be counterproductive to good diabetic control. There is no longer a need for special diabetic foods in the modern dietary management of diabetes.

Diet, Diabetic↗
PubMed1992

A longitudinal study of pelvic inflammatory disease.

OBJECTIVE: To study the microbiology and long term prognosis of pelvic inflammatory disease (PID). DESIGN: A prospective study of women with laparoscopically confirmed PID. SETTING: Teaching hospital in central London. SUBJECTS: 23 women with PID. OUTCOME MEASURES: Microbiological investigations at the time of diagnosis and at follow up; subsequent fertility and the occurrence of pelvic pain. RESULTS: PID diagnosed by laparoscopy was regarded as moderate to severe in 15 cases. Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum or a combination of these micro-organisms were detected most frequently in the cervix, less often in the endometrium and least in the tubes, C. trachomatis being the micro-organism found most commonly in the tubes. There was serological evidence of acute chlamydial infection in 13 of 20 cases in which paired sera were available and a serological response to M. hominis in 9 of 12 cases in which it was possible to evaluate the results. On the basis of microbiological and serological results, C. trachomatis appeared to be the most important aetiological agent in 10 cases, N. gonorrhoeae in four cases, M. hominis in three cases and U. urealyticum in none; in five cases, two of these micro-organisms appeared to be of equal importance. After 1 to 3 years, 33% of the women were having difficulty conceiving and 56% continued to complain of pelvic pain. CONCLUSION: It is difficult to be certain of the infectious cause of PID in any given case. However, the evidence that N. gonorrhoeae and C. trachomatis are pathogens is very strong. M. hominis may be responsible for a few cases on its own or together with other micro-organisms.

Cervix Uteri↗
PubMed1992

Small numbers of Chlamydia trachomatis elementary bodies on slides detected by the polymerase chain reaction.

A method is described in which smears on slides, which had been examined previously in a direct fluorescence antibody (DFA) test for Chlamydia trachomatis, were tested by the polymerase chain reaction (PCR). Twenty four (73%) of 33 smears which contained fewer than 10 elementary bodies when examined by the DFA test were positive by the PCR. Of the nine negative smears, seven contained only one or two elementary bodies. However, single elementary bodies were detected by the PCR in seven of the 24 positive samples. Fifteen smears were negative by both methods. The ability to detect small numbers of elementary bodies by the PCR and its specificity for negative smears indicates its potential for retrospective analysis of stored, archival smears on slides.

Chlamydia Infections↗
PubMed1992

Heterotopic bone formation after total hip arthroplasty.

Formation of heterotopic bone can cause pain and limit motion, thus ruin what would otherwise have been an excellent result after total hip arthroplasty. The cause of bone formation remains controversial, and diphosphonates have been ineffective in its prevention. Radiotherapy and nonsteroidal anti-inflammatory drugs, however, are effective preventative agents. Once the bone is formed, however, surgical excision is the only effective treatment.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1979

Low frequency of chlamydial antibodies in patients with Crohn's disease and ulcerative colitis.

Serum samples from 55 patients with Crohn's disease and from 23 patients with ulcerative colitis were tested for antibodies to Chlamydia trachomatis immunotypes by a micro-immunofluorescence technique. Antibody titres of 1:8 or greater against several immunotypes were detected in 14.5% of patients with Crohn's disease and in 21.7% of those with ulcerative colitis. These figures resemble the incidence in a healthy, non-venereal-disease population. Furthermore, there was no correlation between the presence of antibody and such factors as duration of symptoms, localisation of disease, or disease activity. These findings indicate that there is no reason to believe that Crohn's disease involves chlamydiae or that examination for chlamydial antibody is helpful in diagnosis.

Adult↗
PubMed1979

Nutrient intake, adiposity, and diabetes.

To study the role of nutritional factors in the genesis of diabetes, estimations of blood sugar concentration, food intake, and adiposity (as body mass index; BMI) were carried out on three normal population samples--namely, 961 employees of Beecham Ltd, 1005 employees of the Greater London Council, and 1488 middle-aged male civil servants (Whitehall study). Blood sugar concentrations and indices of glucose tolerance correlated positively with the degree of adiposity but tended to be negatively correlated with total food energy intake and its component nutrients (total carbohydrate, sucrose, and fat). This inverse trend was largely accounted for by highly significant inverse correlations between food energy intake and adiposity, a relation found in both sexes and in all three population samples and which extended across the whole range of nutrient intake and BMI. These findings suggest that greater degrees of adiposity are associated with lower than average food energy intakes and hence lower total energy expenditures. The association of increased adiposity with low food energy consumption may indicate an underlying "low energy throughput" state, and it may be the mechanisms of this, as well as the obesity, that are responsible for disease.

Adipose Tissue↗
PubMed1978

In vivo measurement of calcium by the 37Ar method: a study of the effect of recirculating breath collection systems on the exhalation rate.

A study has been made of the effect that different methods of breath collection have on the measurement of calcium in vivo by the 40Ca(n,alpha) 37Ar method. The effect of open and rebreathing breath collection methods has been examined by using intravenous injections of 133Xe. This study has indicated that comparison of calcium measurements between individuals and between centres is likely to be accurate only if breath is collected on 'open circuit'.

Argon↗