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Biomedical subjects

S T Chambers

Publications and source records attributed to S T Chambers.

At least 91 records · Page 5Linked to original sources
PubMed1991

Pyogenic liver abscesses: a retrospective review of 24 cases.

OBJECTS: to review our experience of pyogenic liver abscess with attention to the value of ultrasound and computerised tomography, and the duration of antimicrobial therapy. METHOD: retrospective review of all pyogenic liver abscesses in Christchurch hospitals between 1972 and 1989. RESULTS: twenty-four cases were identified. The presentation of these cases was typical of those described in other series. Ultrasound scanning was positive in 69% of cases, and computerised tomography in 94%. Enteric organisms were isolated from blood or abscess cavities in all but two cases. Two patients died soon after admission and three were treated with antimicrobial therapy alone. The remainder underwent either a percutaneous or surgical drainage procedure, and received antimicrobial therapy. The antimicrobial therapy was clearly inappropriate in two patients. Eight patients (67%) with single abscesses received less than 10 days of antimicrobial therapy. Four patients (50%) with multiple abscesses received less than 18 days therapy. No patient relapsed. CONCLUSIONS: ultrasound is a convenient initial imaging technique, but may give false negative results. Computerised tomography should be done promptly if clinical suspicion of a liver abscess persists. Both surgical and percutaneous drainage techniques gave good results in combination with antimicrobial therapy. It is probably unnecessary to give prolonged courses of antimicrobial therapy following drainage of single liver abscess, provided there is rapid resolution. Multiple abscesses, or those which are not drained, may require longer courses of antimicrobial therapy.

Adolescent↗
PubMed1991

Antimicrobial effects of lomefloxacin in vitro.

The MIC of lomefloxacin was determined for 554 isolates from the urinary tract. Some of the more resistant strains of Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, and Pseudomonas aeruginosa were studied in a dynamic in-vitro model in order to study dosing strategies. The model simulated, in Mueller-Hinton broth, the profile of plasma lomefloxacin concentrations in volunteers. Bacteria were exposed to a range of lomefloxacin concentration profiles achievable by oral dosing. The first dose of lomefloxacin was rapidly bactericidal in a dose-dependent manner for all strains. On re-exposure, a dose-dependent inhibitory effect was observed. Drug-resistant mutants were readily isolated from all bacteria tested on lomefloxacin-containing plates. These occurred at a high frequency in P. aeruginosa (10(-1)), but less frequently in K. pneumoniae (10(-3)). P. mirabilis (10(-5)), and E. coli (10(-6)). The number of resistant mutants isolated tended to be lower with use of higher drug concentrations. The results suggest that lomefloxacin dosing regimens ensuring maintenance of a high serum concentration: MIC ratio will result in maximal antibacterial effects and minimal problems with resistant strains.

4-Quinolones↗
PubMed1991

Epstein-Barr virus infection acquired from a cadaveric renal transplant.

A 42-year-old man, seronegative for Epstein-Barr virus (EBV), received a cadaveric renal transplant. Serology from the 27-year-old male donor indicated an active EBV infection. Following treatment for acute rejection with OKT3 the recipient developed a severe systemic illness. Clinical features strongly suggested an acute EBV infection and serology showed seroconversion for EBV. The patient died and autopsy histology revealed widespread polymorphic lymphocyte infiltration in lymph nodes and solid organs. To our knowledge this is the first report of a kidney being transplanted from a donor who was subsequently shown to have had EBV infection at the time of organ retrieval. The EBV status of an organ donor should be considered more frequently.

Adult↗
PubMed1989

Antibiotic therapy costs.

The total cost of antibiotics, rather than acquisition costs alone was estimated. Preparation and administration costs, laboratory and monitoring costs, and labour costs are considered separately for the major antibiotics used within Christchurch Hospital. The oral route of antibiotic administration is by far the cheapest. The cost of infusion therapy compared with an IV push is considerable. This added about +15-+30 in equipment costs and another +20-+30 in labour costs and often constituted over 50% of the total cost of therapy. The cost of adverse reactions and differences in efficacy should ultimately be included but it was impossible to quantitate these factors in terms of absolute costs. Acquisition costs alone are a poor guide to the true costs of therapy. The cost of administering the drug should be considered in the contexts of efficacy, toxicity and impact on the environment. We contend that these considerations should be implied to the overall impact on the hospital budget, rather than the pharmacy costs alone.

Anti-Bacterial Agents↗
PubMed1987

Enteric colonization with antibiotic resistant bacteria in nurses working in intensive care units.

To determine whether nurses who worked in an intensive care unit (ICU) might acquire enteric colonization with Gram-negative aerobic bacteria from their patients, rectal swabs were obtained from the patients and nurses in the ICU, from nurses working in a coronary care unit (CCU) and from young women with urinary tract infection who had not been exposed to the hospital environment. The healthy women differed from the patients in that their enteric flora contained greater numbers of lactose fermenting bacteria, they were less often colonized by resistant organisms and when resistant bacteria were present they were less abundant than in the patients. Nurses who had been treated with antimicrobial agents during the preceding six months were colonized more often with antibiotic resistant enteric bacteria. There was no evidence of transmission of antibiotic resistant Escherichia coli from patients to nurses largely because this species had been virtually eliminated from the patients by intensive use of antimicrobial agents. Instead, several multiresistant species of Klebsiella, Citrobacter and Pseudomonas were isolated from the patients and ICU nurses. It was difficult, however, to define clearly patient-nurse controls who had no exposure to the ICU patients. These observations and those of other investigators emphasize the need for examination of control populations and of therapeutic use of antibiotics when examining the issue of environmental acquisition of antibiotic resistant bacteria.

Adolescent↗
PubMed1987

Dimethylthetin can substitute for glycine betaine as an osmoprotectant molecule for Escherichia coli.

Glycine betaine is believed to be the most active naturally occurring osmoprotectant molecule for Escherichia coli and other bacteria. It is a dipolar ion possessing a quaternary ammonimum group and a carboxylic acid group. To examine the molecular requirements for osmoprotective activity, dimethylthetin was compared with glycine betaine. Dimethylthetin is identical to glycine betaine except for substitution of dimethyl sulfonium for the quaternary nitrogen group. Dimethylthetin was found to be about equally as effective as glycine betaine in permitting E. coli to grow in hypertonic NaCl, and both compounds were recovered almost completely from bacterial cells grown in the presence of hypertonic NaCl. 3-Dimethylsulfonioproprionate, an analog of dimethylthetin observed in marine algae, and 3-Dimethylsulfonio-2-methylproprionate were found to be less active. Dimethylthetin may prove useful as a molecular probe to study betaine metabolism and as a model for the development of antibacterial agents.

Betaine↗
PubMed1987

Isolation of glycine betaine and proline betaine from human urine. Assessment of their role as osmoprotective agents for bacteria and the kidney.

Human urine is osmoprotective for enteric bacteria, permitting E. coli to grow with high concentrations of NaCl and other salts and even higher concentrations of sucrose and mannitol but not urea. The active material in urine is soluble in methanol and is precipitated by ammonium reineckate at acid pH. Using gel filtration and high-pressure liquid chromatography, we have identified two major osmoprotective compounds in urine. One is glycine betaine; the other is proline betaine as demonstrated by nuclear magnetic resonance, mass spectrum scanning, and chemical synthesis. Proline betaine has not been described previously to our knowledge in vertebrate tissues. It is known to be a cell volume-regulating agent for marine red algae and the euryhaline mollusk Elysia chloritica. We suggest that the presence of glycine and proline betaines in human urine may reflect an osmoprotective role for the kidney and that they protect bacteria in the urine only fortuitously.

Betaine↗
PubMed1987

Osmoprotective activity for Escherichia coli in mammalian renal inner medulla and urine. Correlation of glycine and proline betaines and sorbitol with response to osmotic loads.

Escherichia coli are protected against hypertonic NaCl by human urine. We have shown that this is due in part to the presence of glycine betaine and proline betaine. Several investigators have proposed that betaines and sorbitol are concentrated in the cells of the renal inner medulla where they exert a protective role against urea and extracellular osmotic forces. E. coli was used in the present studies as an "osmosensor" to detect osmoprotective activity in mammalian tissues. The greatest activity was found in extracts of renal inner medulla and to a lesser extent in the renal outer medulla and cortex of several mammalian species. Liver extracts were more active than other nonrenal tissues. Bacterial osmoprotective activity and concentration of glycine betaine in the renal inner medulla of rabbits were found to correlate closely with urinary osmolarity. Concentrations of sorbitol were found to be also increased in the renal inner medulla during osmotic stress, but this compound is not osmoprotective for E. coli. Glycine and proline betaine were recovered in urine of rabbits and were increased in those given high osmotic loads. Only small amounts of proline betaine were recovered in the renal inner medulla. The source from which proline betaine is derived is unknown.

Animals↗
PubMed1985

Paratyphoid fever presenting with grand mal fits and cerebellar signs.

We report a case of Salmonella paratyphi B infection in a man who presented with cerebellar signs and convulsions. Later he developed vertebral osteomyelitis and a paravertebral abscess. He was treated successfully with chloramphenicol for 14 days and then long-term amoxycillin.

Abscess↗
PubMed1984

Paradoxical expansion of intracranial tuberculomas during chemotherapy.

4 patients with tuberculosis, 3 of whom had tuberculous meningitis, were noted to have tuberculomas on computed tomographic scanning. During antituberculous chemotherapy the intracranial lesions increased in size in all 4 patients at a time when the clinical state and cerebrospinal-fluid abnormalities were improving; in 2 of the patients the regional lymph nodes also enlarged greatly. Though the expansion of the cerebral lesions caused anxiety and led to some changes in chemotherapy, the lesions eventually diminished in size.

Adult↗
PubMed1977

An audit of weight reduction in a diabetic clinic.

A group of long-term attenders at a diabetic outpatient clinic were compared with new patients who were referred for the first time by their own general practitioners. There was some evidence that first attenders, especially women, appear to lose weight significantly over the subsequent three years, such weight loss being more marked when the diet therapy is also combined with a re-organisation of their attendances over a month, to provide education both to the patients and to the relatives. This preliminary information suggests that the development of patient self-sufficiency programmes in diabetes in the New Zealand setting appears to have economic justification.

Body Weight↗
PubMed1976

Lithium associated thyroid disease--a report of 14 cases of hypothyroidism and 4 cases of thyrotoxicosis.

Thyroid function was assessed in 80 patients receiving long-term lithium therapy. Three of the 80 patients were biochemically hypothyroid and a further patient was receiving thyroxine for lithium associated hypothyroidism. A further eight patients had elevated TSH levels and eight patients had subnormal serum triiodothyronine levels. After a 24 month follow up period seven of the 80 patients have developed clinical hypothyroidism. One patient had elevated thyroid parameters and clinical features of mild hyperthyroidism. Additional clinical and laboratory data are included from seven patients with lithium associated hypothyroidism and three patients with lithium associated thyrotoxicosis who were not included in the survey population.

Adolescent↗