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Biomedical subjects

D F Cowan

Publications and source records attributed to D F Cowan.

At least 55 records · Page 3Linked to original sources
PubMed1987

Correlation of histopathological, cytological and flow cytometric findings in neoplastic and nonneoplastic lesions of the bladder.

Biopsy diagnosis, urine cytology and flow cytometry features of urine and bladder washings were compared in 81 cases of benign and malignant bladder disease. Some patients were followed by urine cytology and flow cytometry during treatment of tumors. There was a good correlation of the 3 parameters in relatively high grade tumors (II and III) but an inconsistent appearance of cells in the urine diagnosable by either urine cytology or flow cytometry for low grade lesions. High grade flat neoplasms may be detectable by urine cytology and flow cytometry before they are visible on endoscopy. Flow cytometry may indicate urothelial proliferation before it is apparent on urine cytology. Exfoliative benign lesions are diagnosed readily by the combination of urine cytology and flow cytometry. In benign and malignant lesions shedding of viable cells and, therefore, accessibility to urine cytology and flow cytometry are inconsistent. The need for repeated examinations in the case of low grade lesions suggests that the method is not reliable for single test screening programs but it is a valuable means of followup in cases of suspected or diagnosed disease.

Biopsy↗
PubMed1986

Invasive verrucous carcinoma of urinary bladder treated by irradiation.

A case of inoperable, invasive verrucous carcinoma of the urinary bladder treated by irradiation is presented. The incidence of anaplastic transformation of verrucous carcinoma after irradiation is lower and the coincidence of verrucous carcinoma and well-differentiated squamous carcinoma higher than is generally recognized. Radiation should be considered in inoperable cases. The pertinent literature is reviewed.

Aged↗
PubMed1984

Oral contraceptives, pregnancy, and focal nodular hyperplasia of the liver.

There is uncertainty regarding the role, if any, of oral contraceptive steroids in the development of focal nodular hyperplasia of the liver. In a 36-year-old woman, a large left hepatic lobe tumor developed that was detected after 11 years of using these drugs. The tumor regressed when administration of the drug was stopped but began to increase in size during a subsequent pregnancy. A left hepatic lobectomy during the second trimester disclosed focal nodular hyperplasia. Both contraceptive steroids and pregnancy, with high levels of endogenous sex steroids, favored tumor growth in this patient, suggesting that focal nodular hyperplasia can be steroid related.

Adenoma↗
PubMed1984

Rapid detection of fungi in tissues using calcofluor white and fluorescence microscopy.

Rapid intraoperative examination of tissues for fungi is important for the surgical control of infection. Staining of frozen or paraffin-embedded tissues with calcofluor white (CFW) is a rapid nonspecific method for the identification of fungal infection. When viewed with a fluorescence microscope, fungal elements stained with CFW are sharply delineated from surrounding tissue and easily identified. Calcofluor white also stains tissue elements such as keratin, collagen, and elastin, which provide useful landmarks for the examination. To a much lesser degree, bacteria are also stained with CFW.

Animals↗
PubMed1983

Primary intratracheal neurilemoma.

We report a case in a 38-year-old white woman of a benign primary intratracheal neurilemoma that recurred 12 years after an initial endoscopic excision. Of the 12 intratracheal neurilemomas that have previously been reported, all occurred in white persons in an age range of 6 to 71 years and most were located in the lower trachea and produced symptoms of cough and wheezing.

Adult↗
PubMed1976

Effects of implanted Doppler flowmeters on femoral vein autografts.

Thirteen femoral vein autografts were placed into the corresponding ipsilateral femoral arteries of 8 mongrel dogs. Cuff-type Doppler (ultrasonic) flowmeters were placed around six of the grafts. None of the vessels thrombosed. Blood flow velocities were measured in all vessels up until the time of sacrifice (mean 95 +/- 5 days after surgery) or accidental death (one dog, 49 days after surgery). The only case of graft failure was attributed to infection at the flowmeter site. With this single exception, the vein grafts exhibited uniformity in histological appearance from dog to dog. These data suggest that implantation of properly designed Doppler flow transducers may have clinical applications. This technique permits continuous or intermittent assessment of blood flow characteristics through a graft without additional trauma or cost to the patient. It is free of the many inherent disadvantages of chronically implanted electromagnetic flowmeters and may negate the need in some instances for followup angiographic studies.

Animals↗
PubMed1976

Ultrasonically-guided percutaneous nephrostomy. Report of 24 cases.

Ultrasonically-guided percutaneous nephrostomy using the Seldinger technique was attempted on 24 kidneys in 19 patients with obstructive hydronephrosis. Seventeen of the procedures were successful, 4 failed, and in 3 the catheter slipped out of the renal pelvis 1-48 hours after insertion. The procedure is simple and independent of renal function. Postrenal uremia can be relieved, infected hydronephrosis drained prior to elective surgery, and urinary parameters assessed. Injection of contrast material can define pathological anatomy in those cases where excretory urography and retrograde pyelography are unsatisfactory. No significant complications were encountered.

Fistula↗