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Biomedical subjects

S Pearson

Publications and source records attributed to S Pearson.

At least 19 recordsLinked to original sources
PubMed1992

Use of ribosomal RNA gene restriction patterns to investigate two outbreaks of Campylobacter enteritis in Melbourne, Australia.

The analysis of ribosomal RNA (rRNA) gene patterns (ribotyping) has been used to differentiate strains within bacterial species. We used this method to investigate two outbreaks of campylobacter enteritis that occurred recently in Melbourne, Australia. The first outbreak involved seven patients although isolates from only five patients were available for typing. The second outbreak consisted of three patients infected with human immunodeficiency virus (HIV) on the same ward of a hospital. Analysis of the rRNA gene patterns revealed identical patterns for the isolates from five patients in the first outbreak, suggesting that these isolates were from the same source. However, ribotyping of the four isolates from the second outbreak showed three distinct ribotypes indicative of contact with unrelated sources. This study demonstrated that ribotyping is a useful, reliable and convenient typing scheme for epidemiological purposes.

Australia↗
PubMed1992

Phenotypic variation of Staphylococcus epidermidis isolated from a patient with native valve endocarditis.

Two colonial variants of Staphylococcus epidermidis were isolated from the valvular tissue of a patient with native valve endocarditis. In addition to differing in colonial morphology, the two variants differed in hemolysis on blood-containing media, in adherence capacity, and in the expression of certain enzymes. Under suitable conditions, both variants were themselves capable of phenotypic variation, although they differed in the rate at which variants were generated. The variants yielded identical profiles on restriction endonuclease analysis of plasmid DNA and pulsed-field gel electrophoresis of whole-cell DNA. This report suggests a possible role for phenotypic variation in coagulase-negative staphylococcal virulence. Congo red agar would be an excellent medium for studying the contribution of variation to the virulence of these organisms.

Adult↗
PubMed1991

Induction and prevention of pin loosening in external fixation: an in vivo study on sheep tibiae.

In external fixation of fractures, pin loosening is a major concern. Preloading the pins is generally done to ensure their stability within the bone cortex. The effect of radial preload and bending preload in reducing resorption at the pin/bone interface was tested. Schanz screws were fixed to live sheep tibiae using a pneumatically operated external fixator frame. Evaluation was based on radiological observation and fluorochrome histology using sequential labels. Though not completely absent, bone resorption was minimal in the radial preload group, compared with the two other groups. More important, the bone-to-pin contact surface in the radial preload group was found to be almost intact after 5 weeks. In this study, radial preload appears to be superior to bending preload in terms of minimizing the problems of pin loosening.

Animals↗
PubMed1991

Role of a cell surface-associated protein in adherence and dental caries.

Insertional inactivation of the Streptococcus mutans spaP gene was used to construct an isogenic mutant (834) of strain NG8 (serotype c) which lacked the major cell surface-associated protein referred to as P1 (15). Results of several studies suggest that P1 is involved in the adherence of S. mutans to saliva-coated apatite surfaces. With an in vitro model system of hydroxyapatite (HA) beads coated with parotid saliva (PS) and additional HA surfaces coated with PS and in situ-formed glucan, it was observed that mutant 834 adhered poorly to the PS/HA surfaces. In contrast, both parent and mutant strains bound to the PS-glucan/HA surface. Groups of intact and desalivated rats were infected with each strain to determine relative capacities to induce dental caries. Rats were fed a highly cariogenic diet containing 56% sucrose for 3 to 5 weeks. Each strain colonized the rodent model and caused similar levels of smooth-surface caries under these dietary conditions. It was concluded that P1 influences the ability of organisms to adhere to saliva-coated surfaces and possibly affects primary colonization of the oral cavity in the absence of a glucan surface but has no effect on glucan-mediated adherence in vitro or in vivo.

Animals↗
PubMed1990

Is routine colposcopic assessment necessary following laser ablation of cervical intraepithelial neoplasia?

The colposcopic and cytological findings at follow-up of 1000 women treated by laser ablation for cervical intraepithelial neoplasia or human papillomavirus infection at the Regional Department of Gynaecological Oncology, Gateshead, were reviewed. Colposcopy detected six of 27 patients with residual disease compared with cytology which was abnormal in 26 of the 27 and detected 21 as abnormal on the first visit after laser treatment. In our unit invasive disease after laser treatment was never detected solely on initial colposcopic review.

Adolescent↗
PubMed1990

Loop diathermy cone biopsy.

A technique for cone biopsy using loop diathermy is presented. The diathermy loop consists of an insulated shaft attached to an insulated transverse or U-shaped arm, to which the loop wire is attached. The diathermy power is supplied by an electrosurgical unit. Among the first 50 cases, the mean age was 41.6 years; 72% of the cases were reported as cervical intraepithelial neoplasia III and 6% as microinvasive carcinoma. The mean length of the cone was 20.2 mm and the mean weight 3.9 g. Only 10% of the cones were reported as incompletely excised. No major complications were observed, and minor complications were reported in four patients (8%). We found this technique to be quick, simple, and economical. It provides a good histologic specimen with a low incidence of short-term morbidity.

Adult↗
PubMed1990

Hindfoot arthrodesis in adults utilizing a dowel graft technique.

Surgical fusion may be indicated to stabilize deformed or painful hindfoot joints. Although more commonly performed in children or adolescents, it is the salvage procedure available for adults. Twenty-six patients (30 feet; 20 women, six men) followed for an average of 44.1 months after hindfoot arthrodesis were investigated in a prospective study. Most (20 patients, 24 feet) had inflammatory arthritis, usually rheumatoid, two had previous fractures, and four patients had other diagnoses. All had fusions done using a dowel graft technique. Twenty-four patients (92%) were completely satisfied with the operation, one had mild reservations, and the one dissatisfied patient was a technical failure. All joints were fused utilizing clinical and roentgenographic evaluation. A detailed roentgenographic assessment indicated that the talometatarsal angle was the most effective measurement to assess the clinical deformity. Anteroposterior weight-bearing roentgenograms of the ankle were also important in evaluating these patients preoperatively and postoperatively. Postoperatively, only nine ankles appeared normal roentgenographically, while the others worsened, and four required ankle arthrodesis.

Adult↗
PubMed1979

Clinical use of cefamandole: a new cephalosporin.

Cefamandole, a new cephalosporin derivative, has been used in treatment of six patients who had diminished renal function and respiratory infections, and of 14 patients with urinary tract infections (UTI). Infection was eliminated in all patients with respiratory infections, and in seven of the patients with UTI. No serious side effects were encountered and, even in patients with pre-existing renal dysfunction, no reduction in renal function occurred.

Adolescent↗
PubMed1979

The treatment of ACTH Paraneoplastic syndrome with aminoglutethimide.

A 60-year-old white female with oat-cell carcinoma of the lung presents with a recurrent pulmonary nodule and Cushing syndrome. The tumor is uncontrollable with MeCCNU and cyclophosphamide (Cytoxan), consequently the symptoms of Cushing disease become severe. Cushing syndrome is documented by laboratory examinations. Aminoglutethimide, an anticonvulsant, is used to reverse the symptomatology and also the laboratory values. When aminoglutethimide is discontinued, the laboratory findings return to pretreatment levels.

Adrenocorticotropic Hormone↗
PubMed1978

Serum beta2-microglobulin in the assessment of renal function.

This study was undertaken to compare the serum beta2-microglobulin (beta2-m) as a test of renal function with the plasm creatinine and the glomerular filtration rate as estimated by the 24 hour endogenous creatinine clearance and the single injection 51Cr EDTA clearance method. Of the 33 patients with a variety of renal diseases and the four healthy volunteers studied, an excellent correlation was found between the serum beta2-m concentration (measured by radioimmunoassay) and the plasma creatinine, the creatinine clearance and the 51Cr EDTA clearance. When a more simple and less expensive method becomes available for the measurement of serum beta2-m it could prove a useful test of renal function. The assay of beta2-m in the urine could prove valuable for assessing whether proteinuria is glomerular or tubular in origin.

Beta-Globulins↗