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Biomedical subjects

R G Bennett

Publications and source records attributed to R G Bennett.

At least 73 records · Page 4Linked to original sources
PubMed1991

Cigarette smoking and flap and full-thickness graft necrosis.

The association between cigarette smoking and necrosis of flaps and full-thickness grafts was analyzed in 220 patients. Review of a series of 916 flaps and full-thickness grafts revealed 44 patients in whom some degree of tissue necrosis occurred. These patients with necrosis were age and gender matched with 176 controls randomly selected from the remaining 872 patients. Current high-level smokers, that is those smoking one or more packs per day, had necrosis develop approximately three times more frequently than never smokers, low-level smokers (less than one pack per day), or former smokers (95% confidence interval, 1.2 to 8.2). Former smokers (relative risk, 1.4; 95% confidence interval, 0.6 to 3.2) and low-level smokers (relative risk, 1.1; 95% confidence interval, 0.2 to 6.1) were at a negligible increased risk for necrosis that was not significantly different from never smokers. Once tissue necrosis developed, the median percent of the visible flap or graft tissue that necrosed was approximately threefold greater among current smokers (regardless of the number of packs per day smoked) than never smokers.

Adult↗
PubMed1990

Fine-needle aspiration for diagnosis of intranodal squamous-cell carcinoma metastatic from the skin.

Fine-needle aspiration is a useful way to determine the presence of squamous-cell carcinoma in enlarged lymph nodes of patients at high risk for metastases. Advantages include a high degree of accuracy, outpatient as well as inpatient availability, and negligible potential for seeding of malignant cells. Cutaneous oncologists should consider using this technique in patients with lymphadenopathy and a previous history of cutaneous squamous cell carcinoma.

Aged↗
PubMed1990

Systemic isotretinoin: effects on dermal wound healing in a rabbit ear model in vivo.

Clinical observations have suggested that wound healing may be altered in patients treated with systemic isotretinoin. In this study, we examined the effects of systemic isotretinoin on dermal wound healing and connective tissue metabolism in a rabbit ear model. Forty 6-mm punch-biopsy wounds were created in the ears of two control rabbits as well as two experimental animals fed isotretinoin, 4 mg/kg per day. Clinical inspection and histologic examination revealed no difference between the control and isotretinoin-treated rabbits in terms of the time required for complete wound healing or the appearance of the final scar. The tissue removed from the wound site at days 0, 7, 14, and 21 after wounding was subjected to analysis of a collagen production and collagen gene expression. Collagen production, determined by the synthesis of [3H]hydroxyproline after incubation of tissue slices with [3H]proline in vitro or by the measurement of the steady-state levels of types I and III procollagen mRNAs, was not significantly different between the two groups. The results indicate that systemic administration of isotretinoin does not affect collagen synthesis in the rabbit ear model of wound healing.

Animals↗
PubMed1990

The bilateral dog-ear transposition flap.

An original technique is presented for the closure of circular defects that cannot be closed primarily without undue tension. The technique involves the creation of dog-ear tissue, which is then fully utilized in the closure. The technique involves no sacrifice of normal tissue and results in a relatively short, cosmetically acceptable scar.

Dermatologic Surgical Procedures↗
PubMed1990

Acne keloidalis.

Explore the source record for details and available documents.

Acne Keloid↗
PubMed1990

Postantibiotic colonization with Clostridium difficile in nursing home patients.

Clostridium difficile causes pseudomembranous colitis and is responsible for 20% to 25% of cases of postantibiotic diarrhea. In an earlier study, nursing-home patients with C. difficile infection were noted to have a high mortality rate. Because most of these infected patients had been treated with antibiotics, it was not clear whether this high mortality rate was associated with C. difficile infection or simply with antibiotic treatment. A prospective study was carried out to determine the rate of postantibiotic C. difficile colonization and risk factors for infection in patients in a 233-bed long-term care facility, as well as to determine whether C. difficile infection is associated with increased mortality. During a six-month period 150 courses of antibiotics were prescribed for 108 patients. Stool specimens were collected from 36 (33%) patients following the first course of antibiotic treatment, and 12 (33%) were infected with C. difficile. Risk factors for infection included ward location and stool incontinence. Age, body-mass index less than or equal to 18 kg/m2, and diagnoses of dementia and pressure scores tended to be associated with infection, but not significantly. Early mortality rates did not differ, but 12-month mortality for the infected patients was higher (83% vs 50%, P = .05). Therefore, we conclude that postantibiotic C. difficile infection serves as a marker of death in nursing-home patients, one that can be differentiated from the risk of antibiotic treatment alone. This increased death rate may be related in part to clinically unrecognized pseudomembranous colitis or, alternatively, to absorption of C. difficile toxins or even endotoxin from the gut lumen into the systemic circulation.

Adult↗
PubMed1990

Bacterial transference during electrodesiccation and electrocoagulation.

Electrodesiccation and electrocoagulation are commonly used to control bleeding and destroy tissue. In certain outpatient settings, the clinician routinely uses one of these electrosurgical modalities on successive patients without sterilization or antisepsis of the treatment electrode tip. In controlled laboratory experiments using electrodesiccation and electrocoagulation, we investigated bacterial transference of Staphylococcus aureus from inoculated tissue to sterile electrode tips and from inoculated electrode tips to sterile tissue. With use on inoculated tissue, sterile electrode tips remained sterile after electrocoagulation but not after electrodesiccation. Bacterial transference from inoculated electrode tips to sterile tissue occurred with electrodesiccation but not with electrocoagulation. These results are consistent with bacterial destruction by electric current and suggest that bacterial transference via the treatment electrosurgery electrode from one patient to another is possible but much more probable during electrodesiccation than during electrocoagulation.

Animals↗
PubMed1989

Protein-losing enteropathy associated with Clostridium difficile infection.

A commercially available radial immunodiffusion assay was used to measure serum alpha-1-antitrypsin levels in stool samples from subjects aged over 60 years as a marker of protein-losing enteropathy. alpha 1-antitrypsin was found in all of 12 patients with colonoscopy-confirmed pseudomembranous colitis, 6 of 14 (43%) patients with Clostridium difficile diarrhoea without pseudomembranes, 6 of 12 (50%) nursing-home patients culture-positive for Cl difficile but negative for its cytotoxin, and none of 15 healthy control subjects. It is concluded that serum protein loss into the gastrointestinal tract can occur as a result of Cl difficile infection, that its presence correlates with the severity of disease, and that it may occur even in the absence of diarrhoea. The diagnosis of protein-losing enteropathy should be considered for all patients with Cl difficile infection, particularly elderly nursing-home patients, in whom the risk of Cl difficile disease and the frequency of severe malnutrition are high.

Adolescent↗
PubMed1989

Human papillomavirus type 16 DNA in periungual squamous cell carcinomas.

Ten squamous cell carcinomas (in situ or invasive) of the fingernail region were analyzed for the presence of DNA sequences homologous to human papillomavirus (HPV) by dot blot hybridization. In most patients, the lesions were verrucae of long-term duration that were refractory to conventional treatment methods. Eight of the lesions contained HPV DNA sequences, and in six of these the sequences were related to HPV 16 as deduced from low-stringency nucleic acid hybridization followed by low- and high-stringency washes. Furthermore, the restriction endonuclease digestion pattern of DNA isolated from four of these lesions was diagnostic of episomal HPV 16. The high-frequency association of HPV 16 with periungual squamous cell carcinoma is similar to that reported for HPV 16 with squamous cell carcinomas on mucous membranes at other sites, notably the genital tract. Our findings suggest that HPV 16 may play an important role in the development of squamous cell carcinomas of the finger, most notably those lesions that are chronic and located in the periungual area.

Adult↗
PubMed1989

Air-fluidized bed treatment of nursing home patients with pressure sores.

There are no large studies on long-term treatment of nursing home patients with pressure sores. A 4-year experience of treating 95 nursing home patients on air-fluidized beds was reviewed. Treated patients were elderly (median age 73 years) and neurologically impaired (79% with dementia, cerebral vascular accident, or anoxic encephalopathy). The index pressure sores (deepest truncal sore for each patient) were large (median surface area 35.3 cm2) and commonly located on the sacrum (41%) and trochanters (38%). Only 13 of 95 (14%) index sores healed completely, and only two small sores healed in less than 30 days. No others treated less than 30 days had greater than or equal to 50% reduction in sore surface area. Patients were grouped according to whether or not treatment was less than 30 days, and for those treated greater than or equal to 30 days, according to whether or not greater than or equal to 50% reduction in sore surface area occurred. None of the easily measured patient characteristics examined were associated with longer or more successful treatment. These results indicate that although air-fluidized beds can be used to treat pressure sores successfully, even in severely debilitated nursing home patients, no simple criteria can be used to predict which patients will benefit from this treatment. Because long periods of time are necessary for treatment [median trial length 79 days and 17 of 95 (18%) trials greater than 180 days], substantial patient-care expenditures result.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Evaluation of a latex agglutination test for Clostridium difficile in two nursing home outbreaks.

The Culturette Brand Clostridium difficile test (CDT; Marion Laboratories, Inc., Kansas City, Mo.) is a latex agglutination test for C. difficile. The recent controversy involving the identity of antigens detected by CDT has made decisions on its use difficult. We compared the test results with those of selective culture and stool cytotoxin assays in investigations of two nursing home outbreaks of C. difficile-associated disease in order to formulate usage recommendations. Selective culture for C. difficile identified 27 (19%) of 142 subjects as carriers. CDT and the stool cytotoxin assay identified only 52 and 48% of these carriers, respectively. Compared with the stool cytotoxin assay, CDT had a high sensitivity (92%) and specificity (89%) for the detection of C. difficile disease, but the positive predictive value of the test was only 17% when the prevalence of disease was 2%. We conclude that the CDT should not be used to identify carriers but that it is a sufficiently sensitive and specific screening test for diagnosing C. difficile disease. However, since the positive predictive value of the CDT is low when the prevalence of disease is low, positive test results should be confirmed by the stool cytotoxin assay.

Adult↗
PubMed1989

Mohs micrographic surgery for skin cancers of the neck.

The neck is not a common area for a skin cancer to occur. However, when it does occur and extends deeply, careful extirpation is necessary so that vital structures will be identified and, if possible, preserved. The Mohs surgeon can most accurately determine the true extent of malignancies in this area; the head and neck surgeon can best identify and protect important anatomic structures. Together both physicians can achieve the best chance of cure and lessen the complication rate for patients with selected invasive cutaneous tumors of the neck. Future collaborative efforts will undoubtedly be directed toward complete extirpation of deeper tumors of the neck, especially those of the pharynx, hypopharynx, and trachea.

Head and Neck Neoplasms↗
PubMed1989

The meaning and significance of tissue margins.

The treating surgeon should be aware of the various methods of grossly sectioning and microscopically examining tissue. For tumors that are life threatening or difficult to cure, one should request careful examination of as much of the cut surgical margins as feasible. Whatever is done with the tissue, the physician should communicate adequately with the pathologist so that each will be aware of the other's limitations and what is actually being provided for the patient. Proper understanding of the terms cut surgical margins and pathologic margins and their general noncongruence will help to dispel confusion and lend credence to more carefully constructed studies in the future.

Biopsy↗
PubMed1988

Selection of wound closure materials.

Selection of wound closure materials (sutures, needles, staples, and skin tapes) is presented. The characteristics of commonly used suture materials and needles are discussed as a background for their rational selection and usage. The attributes of staples and sutureless skin closures (skin tapes) are also given and contrasted with those of sutures.

Absorption↗
PubMed1988

Selectively enhanced procollagen gene expression in sclerosing (morphea-like) basal cell carcinoma as reflected by elevated pro alpha 1(I) and pro alpha 1(III) procollagen messenger RNA steady-state levels.

Sclerosing or morphea-like variant of basal cell carcinoma (BCC) is characterized by an extensive connective tissue stroma, and histopathology has suggested that the extracellular matrix is largely composed of collagen. In addition, fibronectin deposition has been proposed to modulate tumor growth in BCC. In this study, we examined the expression of genes coding for type I, III, and IV procollagens, as well as for fibronectin, in tissue from 10 patients with sclerosing BCC. For comparison, tissues from 5 patients with nodular BCC and 4 controls were examined. Total RNA was isolated by CsCl density gradient centrifugation, and messenger RNA (mRNA) steady-state levels were determined by slot-blot hybridizations with human sequence specific complementary DNAs (cDNAs). The abundance of type I procollagen mRNA in sclerosing BCC tissue was increased to 233.6 +/- 36.7% of the controls (mean +/- SEM). The corresponding value for type III procollagen mRNA in sclerosing BCC was 281.8 +/- 54.8% of the controls. Consequently, the steady-state ratio of type I/III procollagen mRNAs in sclerosing BCCs (5.0 +/- 1.2; mean +/- SD) was within the control range. Thus, there is a coordinate increase in type I and type III procollagen mRNA levels in sclerosing BCC. In contrast, the values for type I and type III procollagen mRNAs in nodular BCC were not different from the controls. In addition, type IV procollagen and fibronectin mRNA levels were not different from the controls either in sclerosing or nodular BCCs, attesting to the selectivity of the increase in type I and III procollagen mRNA levels in sclerosing BCC. These observations may relate to the excessive deposition of the extracellular matrix stroma surrounding the tumor cells in sclerosing BCC.

Basal Cell Carcinoma↗