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Biomedical subjects

D C Whitaker

Publications and source records attributed to D C Whitaker.

At least 19 recordsLinked to original sources

Angina with a normal coronary angiogram caused by amyloidosis.

A case of severe intractable angina pectoris with normal angiography is presented. Following video assisted thoracic sympathectomy the patient died of heart failure. Microvascular cardiac amyloidosis was diagnosed at the postmortem examination. This report alerts clinicians to this possible diagnosis when treating patients with severe angina when no cause is found and discusses the poor prognosis in such cases.

Aged↗

Neuroprotection during cardiac surgery: strategies to reduce cognitive decline.

Although the population receiving cardiac surgery is older and therefore more prone to cognitive deterioration, these difficulties have declined over the last ten years. It is likely that the multiple changes introduced to cardiac surgery over time have had a cumulative benefit in protecting the brain. The most likely causes of cognitive difficulties are microemboli delivered to the brain during surgery, altered cerebral perfusion and an inflammatory response. The interventions that have been implemented can be divided into those which have attempted to reduce the potential causes of damage and those aimed at reducing the impact by attempting to protect the brain. The evidence for three main types of intervention (equipment, techniques and drugs) is reviewed in this paper. Although many interventions are available only a few have shown a clear benefit. Progress in the future will require larger studies to address this multifactorial problem.

Brain↗

Postsurgical wound management.

Successful outcomes in cutaneous surgery depend on a variety of factors, including preoperative assessment of the patient's health and expectations, intraoperative skill and attention to detail, and managing the postoperative period. Once the procedure is complete, careful selection of dressings, provision of adequate analgesia, judicious management of complications and monitoring the phases of early maturation while providing patient education improve the likelihood of long-term patient and physician satisfaction.

Analgesia↗

The impact of herbal medicines on dermatologic surgery.

BACKGROUND: In recent years herbal medicines and supplements have become increasingly popular. With their increased popularity, more publications are warning about the potential harmful effects of some of these products. OBJECTIVE: To present scientific evidence of the benefits and surgical risks of herbal products. METHODS: A Medline search and review of the literature was performed. RESULTS: Many herbal medicines are relevant in dermatologic surgery since Ginkgo biloba, garlic, ginger, ginseng, feverfew, and vitamin E may increase the risk of bleeding, and ephedra may potentiate the side effects of epinephrine. CONCLUSION: Dermatologists should be aware of these herbal products and their uses. Many of these products prescribed by alternative medicine physicians or purchased over the counter should be discontinued prior to dermatologic surgery to minimize the risk of surgical complications.

Blood Loss, Surgical↗

The use of leucocyte-depleting and conventional arterial line filters in cardiac surgery: a systematic review of clinical studies.

Although various forms of arterial line filter have been available for use during cardiopulmonary bypass (CPB) for 30 years, their use is not universal. The aim of this review was to seek evidence of the clinical benefit of using conventional or leucocyte-depleting arterial line filters during bypass. A literature search revealed 28 relevant clinical studies. Despite the wide variety of patient populations, types of filter and outcome measures utilized in studies, a few conclusions are possible. Whereas conventional filtration has the definite effect of reducing neuropsychological deficit post-CPB, the results of studies using the leucocyte-depleting filter are less clear cut. Leucocyte-depleting filters have potential for reducing inflammatory mediated heart and lung injury, however it is recommended that any additional benefit of leucocyte-depleting filters over conventional filters should be further tested by randomized controlled trials of sufficient size.

Cardiopulmonary Bypass↗

Injectability and tissue compatibility of poly-(N-vinyl-2-pyrrolidone) in the skin of rats: a pilot study.

BACKGROUND: Filling substances have been used in dermatologic surgery for decades, but an ideal agent has yet to be discovered. Poly-(N-vinyl-2-pyrrolidone) is a hydrogel that has been used in medical settings for more than 50 years, but not as a cutaneous filling agent. OBJECTIVE: We investigated the intracutaneous injectability and tissue compatibility of this hydrogel in a rat model. Particular attention was paid to ease of injection through small needles, volume retention of the implant, clinical course, and histocompatibility. METHODS: The shaved backs of 12 anesthetized Sprague-Dawley rats were injected with the sterilized hydrogel and the rats closely observed. The rats were sacrificed in groups of four at 2, 4, and 12 weeks after implantation. Implant size was measured, volume calculated, and biopsies taken at each time interval. RESULTS: Poly-(N-vinyl-2-pyrrolidone) is easily injected through 30-gauge needles. All rats tolerated the implants well clinically. Histopathology revealed well-circumscribed implants with pseudoencapsulation, neoangiogenesis, and mixed inflammatory cells predominating at the periphery. Volume calculations revealed an average of 33% reduction at 4 weeks and 35% reduction at 12 weeks. CONCLUSION: Poly-(N-vinyl-2-pyrrolidone) is easy to inject intracutaneously and is well tolerated in the rat model. Short-term volume retention is good. Histopathology suggests a subclinical inflammatory reaction expected with implantation of a synthetic substance into the skin. Additional studies are necessary to investigate the continued persistence of the hydrogel and its long-term effects on surrounding tissue.

Animals↗

Clinical factors influencing periocular surgical defects after Mohs micrographic surgery.

PURPOSE: To determine if the surgical defect after excision of periocular skin cancers can be predicted preoperatively. METHODS: Review of medical records of patients who underwent excision of periocular skin cancers between 1990 and 1995. RESULTS: Two hundred sixty-four patients (157 men, 107 women) with a total of 281 malignant tumors were treated. Basal cell carcinoma accounted for 92.2% of the tumors, whereas squamous cell carcinoma constituted 6.4% of lesions. The lower eyelid and medial canthus were the most frequent sites of involvement. Data analysis was conducted on tumor size, cell type, location, and the Mohs stages and sections that were required for cure. Morpheaform basal cell carcinomas required the most Mohs stages and sections and resulted in the largest excisional defects when compared with clinical tumor dimensions. The lateral canthus had the fewest tumors, but lesions in this area resulted in the largest excisional defects (mean, 9.5 cm2) when compared with lesions of the medial eyelid (p = 0.35). The average size of the defect after Mohs excision of basal cell carcinoma was 4.2 to 4.6 times the original clinical tumor size. For morpheaform basal cell carcinoma, however, the average excisional defect was 6.1 times larger. Conversely, the average defect after excision of squamous cell carcinoma was only 2.6 times as large as the original clinical tumor size. CONCLUSIONS: These data are useful in predicting the size of a defect after Mohs excision of periocular skin cancer, based on the original clinical tumor size.

Adolescent↗

The independent pathology laboratory as a reporting source for cutaneous melanoma incidence in Iowa, 1977-1994.

BACKGROUND: Health care changes during the past decade have resulted in a greater proportion of cutaneous melanoma (CM) cases diagnosed in nonhospital settings, increasing the potential for cases to be missed by population-based cancer registries. OBJECTIVE: Our purpose was to assess changes in case-finding sources in Iowa from 1977 to 1994 and to determine the extent of underreporting for the State Health Registry of Iowa, a population-based cancer registry. METHODS: This study examines changing trends in the incidence of CM and compares case-finding sources (hospitals/clinics, hospital pathology laboratories, and independent pathology laboratories). A survey of dermatologists serving Iowans provides estimates of underreporting. RESULTS: During the period 1977 to 1994, invasive CM increased 82%, whereas in situ CM increased 900%. The proportion of CM cases diagnosed in independent pathology laboratories increased to 25% of all cases. A range of 10.4% to 17.1% underreporting was estimated based on the survey of dermatologists. CONCLUSION: To improve the accuracy of surveillance, population-based cancer registries need to make a greater effort accessing pathology reports from nonhospital settings.

Dermatology↗