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Biomedical subjects

S R Clark

Publications and source records attributed to S R Clark.

32 records · Page 2Linked to original sources
PubMed1989

Rectal prolapse caused by blunt abdominal trauma.

We describe a case of incarcerated rectal prolapse caused by blunt abdominal trauma. Emergency treatment consisted of manual reduction with the patient under general anesthesia, proctosigmoidoscopy, and peritoneal lavage. Subsequent definitive surgical therapy was then performed after bowel preparation and consisted of anterior resection of the sigmoid colon with posterior (sacral) rectopexy.

Abdominal Injuries↗
PubMed1989

Mass fatality aircraft disaster processing.

On Dec. 12, 1985, a contract transport carrying 248 U.S. Army personnel crashed on takeoff at Gander, Nfld., Canada, killing all the passengers as well as the crew of eight. This was the worst aircraft accident in U.S. military history and, at the time was the fifth worst accident in aviation history. Cooperation between the governments of Canada and the United States allowed for the transport of all human remains to the U.S. Air Force mortuary facility at Dover AFB, DE, where they were processed, identified, and ultimately returned to their families for burial. Under ideal circumstances, any medical examiner's office or mortuary facility would be overwhelmed by a mass disaster of this magnitude. Before the arrival of the first shipment of bodies, a concerted planning effort was undertaken and the facility arranged so that remains would pass in a logical sequence through a series of 10 "work stations." This report details the process and outlines the logistics of the operations.

Accidents, Aviation↗
PubMed1988

A comparison of cyclobenzaprine and placebo in the management of fibrositis. A double-blind controlled study.

The efficacy of cyclobenzaprine (Flexeril), as compared with placebo, was tested in a 12-week, double-blind, controlled trial of 120 patients with fibrositis. Of the patients who received placebo, 52% dropped out due to lack of efficacy of the drug, compared with 16% of patients taking cyclobenzaprine. The dropout rate due to adverse reactions was similar in the 2 groups. Patients taking cyclobenzaprine experienced a significant decrease in the severity of pain and a significant increase in the quality of sleep. There was a trend toward improvement in the symptoms of fatigue, but morning stiffness was not alleviated. These improvements in symptoms were associated with a significant reduction in the total number of tender points and in muscle tightness. Our findings indicate that cyclobenzaprine is a useful adjunct in treating patients with the fibrositis syndrome.

Adult↗
PubMed1988

Electromyographic biofeedback for treatment of tinnitus.

Electromyographic (EMG) feedback procedures were utilized in treating two adult patients with idiopathic subjective tinnitus. The relationship between behavioral severity ratings of tinnitus and EMG activity at the frontalis muscle was investigated using a single-subject, double-reversal experimental design. Biofeedback procedures were effective in modifying EMG activity levels, but changes in EMG levels were not related systematically to behavioral ratings of tinnitus. It was concluded that the physiologic effects of EMG biofeedback procedures may not be the active ingredient in such treatment procedures.

Biofeedback, Psychology↗
PubMed1987

Morphological and metastatic murine melanoma variants: motility, adhesiveness, cell surface and in vivo properties.

The behaviour in vivo of tight and loose variants of murine melanoma cells is further characterized. In vitro clonal morphology is reproduced on a variety of substrates. Results suggest that repeated selection of loose cells can co-select for cells with high metastatic and colonization potentials. Measurement of cell motility shows that 1G3 (loose) cells are more motile than 1G8 (tight) which are restricted to movements within clonal boundaries. Studies of adhesive properties show that loose cells are more easily detached from the substrate with trypsin or EDTA and that both cell lines attach more quickly to monolayers of loose cells than to tight ones. No gross differences are found either in attachment rates to plastic and ECM or in aggregation and disaggregation rates. Analysis of the cell surface has not revealed any differences between 1G8 and 1G3 in the sialylation of terminal galactose and N-acetylgalactosamine residues or in neuraminidase releasable sialic acid. The binding patterns of iodinated lectins to SDS-PAGE separated proteins are similar for both lines except for one 85/90 KD protein which is more abundant in 1G3 than 1G8 cells after neuraminidase treatment. The results show enhanced differences in metastatic potential of tight and loose clones after selective cloning and that there may be important differences in motility and cell-substrate interactions.

Animals↗
PubMed1984

Selection of metastatic variants on the basis of clonal morphology in vitro.

The highly metastatic mouse melanoma cell line F87 C16 T2 is heterogeneous for clonal morphology in vitro. Tight, intermediate and loose morphologies can be distinguished. The tight and loose morphologies are selectable on repeated subcloning and stable for at least 15 passages in vitro. Both types of clones and the cell lines derived from them produce tumours in mice but the loose cells produce faster growing primaries and more secondary deposits than tight cells. The loose cells grow only marginally faster than the tight cells in vitro and the saturation densities of both are similar. Direct cloning of cells dissociated from tumours shows that the tight and loose morphologies are stable in vivo and that there is no obvious selection for either cell type in primary or secondary tumours. Nevertheless injections of progressively fewer cells suggests that loose cells are up to ten times more efficient at producing tumours. Our findings are discussed in relation to current ideas on the importance of heterogeneity and selection in the production of metastases.

Animals↗
PubMed1983

Cell fusion segregates progressive growth from metastasis.

Cell fusion has been used to analyse the genetic determinants of metastasis at the cellular level. Highly metastatic mouse melanoma cells were fused with diploid mouse lymphocytes and a range of hybrid clones isolated and tested for tumorigenicity and metastatic potential by s.c. injection into newborn, histocompatible, sublethally-irradiated mice. Although almost all clones tested were tumorigenic, most had considerably reduced metastatic potential. This suggests that tumorigenicity and metastasis are determined by different genetic elements. Histological examination of primary tumours produced by metastatic and non-metastatic hybrid cell lines showed that an essential step in the production of metastases is the separation of tumour cells from the main tumour mass and their movement into the surrounding tissues. The primary tumours of a metastatic hybrid cell line showed local invasiveness whereas those of a non-metastatic cell line did not.

Animals↗
PubMed1981

Electromyographic feedback treatment for tinnitus aurium.

The relationship between behavioral severity ratings of tinnitus and electromyographic (EMG) activity recorded at the frontalis muscle was investigated in a single adult female. A within-subject, double reversal experimental design was utilized. Although auditory biofeedback procedures were effective in decreasing and increasing EMG activity at frontalis muscle sites, changes in EMG levels were not systematically related to behavioral severity ratings of either tinnitus or annoyance. Psychoacoustic judgements of tinnitus parameters were similarly unrelated to EMG levels. Psychological strategies were developed by the subject that apparently were associated with increases as well as decreases in EMG activity.

Behavior↗
PubMedDate not supplied

Relationship of osteomyelitis and associated soft-tissue lesions with green liver discoloration in tom turkeys.

Tom turkey carcasses with partial green discolored livers (n = 191) or normal livers (n = 198) were examined for osteomyelitis and/or associated soft-tissue lesions. Seventy-nine turkeys with green discolored livers had osteomyelitis and/or associated soft-tissue lesions (41.4%), including 53 with just osteomyelitis (27.7%), while 112 (59.6%) had no osteomyelitis and/or soft-tissue lesions. Only five turkeys (2.5%) with normal livers had osteomyelitis. Discolored livers were significantly heavier, but carcasses with discolored livers weighed significantly less than carcasses with normal livers. Bacteria were isolated from 54 of 61 osteomyelitis lesions (88.5%); most frequently staphylococci (50.8%) followed by Escherichia coli (14.8%), Streptococcus sp. (13.1%), and occasional other organisms. Most associated soft-tissue lesions and livers were sterile (74.7%). These finding indicate that although turkey carcasses with green discolored livers are more likely to have osteomyelitis and/or associated soft-tissue lesions than turkey carcasses with normal livers, there is also an approximately equal chance they will not have these lesions.

Abattoirs↗
PubMedDate not supplied

Soft tissue problems associated with rheumatic disease.

Rheumatic disease and associated soft tissue problems encompass a large number of syndromes and account for a high percentage of visits to primary care practitioners. This article describes the symptoms, causes, and treatments for five of the problems most commonly encountered: bursitis, tendinitis, carpal tunnel syndrome, myofascial pain syndrome, and fibromyalgia. Effective management requires a structured history, physical examination, and definitive diagnosis that distinguishes the soft tissue problem from a joint problem and an inflammatory syndrome from a noninflammatory syndrome. The overriding principle is self-management of treatments that focuses on relief of pain, maintenance of function, and avoidance of factors that cause recurrence or exacerbation of the problem. Medications, physical therapies, biomechanical aids, and exercise strategies, along with cognitive-behavioral techniques for the more chronic problems, are all known to decrease symptoms and to assist patients in returning to normal functioning.

Bursitis↗