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Biomedical subjects

P Humphrey

Publications and source records attributed to P Humphrey.

At least 37 records · Page 2Linked to original sources
PubMed1994

Comparison of retrograde endo-pyelotomy and endo-balloon rupture of the ureteropelvic junction in a porcine model.

Excellent results and durable success have been achieved with antegrade and retrograde endo-pyelotomy for treating primary and secondary ureteropelvic junction obstruction. Recently, a 30F dilating balloon was used to rupture the ureteropelvic junction (ENDOBRST) with encouraging results. While balloon distention of the ureteropelvic junction is a technically simpler procedure than endo-pyelotomy, clinical and laboratory data comparing the 2 methods are lacking. In an acute and chronic animal study we compared endo-pyelotomy via a ureteral cutting balloon incision to balloon rupture (that is 30F) of the normal ureteropelvic junction in each of 20 female farm pigs. Eight pigs were harvested acutely after treatment, and a macroscopic and histological examination of the treated ureteropelvic junction was completed. In 11 chronic pigs after endo-pyelotomy a 7F double pigtail ureteral stent was placed bilaterally and then removed after 6 weeks. Evaluation in the chronic group consisted of a furosemide washout renogram and retrograde pyelogram immediately preoperatively and 6 weeks after stent removal. The animals were likewise harvested 6 weeks after stent removal. One control pig underwent passage of the balloon cutting catheter and balloon dilating catheters without activation or dilation, respectively. Ureteral stents were placed bilaterally for 6 weeks and the pig was otherwise treated similarly to the other chronic study animals. In the acute group all ureters after endo-pyelotomy demonstrated retroperitoneal extravasation of contrast material. At harvest the ureters had been cleanly incised along a length of 3 to 4 cm. through the adventitial layer. In contrast, the balloon treated ureters showed free retroperitoneal extravasation in only half of the animals. Among the balloon treated ureters 7 of 8 had a linear tear of varying length (1 to 5 cm.) involving all but a thin adventitial layer of tissue. Histologically, the endo-pyelotomy ureters demonstrated a clean, linear transmural incision with virtually no destruction of surrounding tissue in 6 cases. In the remaining 2 cases an incision into but not completely through the muscular layer was observed. The balloon treated ureters showed a perforation through the muscular wall in 7 cases. However, periureteral hemorrhage and urothelial loss were common findings. In the chronic group infection and continued urine extravasation from the endo-pyelotomy site resulted in a 45% mortality rate. Of the surviving 6 pigs 83% of the balloon treated and 67% of the endo-pyelotomy pigs had a patent ureteropelvic junction by retrograde pyelogram and renogram. Histologically, the 2 sides were indistinguishable, with both showing mild fibrosis and chronic inflammation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Development of a mouse model for nonbacterial prostatitis.

Nonbacterial prostatitis is a common clinical entity which is often difficult to diagnose and treat. Little is known with regard to the etiology and pathogenesis of this disease process. To develop an animal model and characterize the immune parameters of nonbacterial prostatitis, we harvested the prostates from SJL, AJ, Balb/c, C57bl/6 and C57bl/6 lpr mice. These prostates were homogenized and injected into syngeneic mice. Controls were injected with Freund's complete adjuvant only. Mice from each group were sacrificed 30 days after injection, and the prostates were harvested. Prostatic tissue was examined histologically for degree of inflammation. None of the Balb/c mice exhibited prostatic inflammation. The SJL and AJ mice exhibited varying degrees of prostatic inflammation. All of the C57bl/6 mice were found to have lymphocytic infiltration of the stroma and periglandular region. The C57bl/6 lpr mice did not appear to be more susceptible than the parental strain. Adoptive transfer studies demonstrated the prostatic inflammation to be at least in part immune mediated. We conclude that injection of syngenic prostate antigen induces prostatic inflammation similar to clinical nonbacterial prostatitis. Nonbacterial prostatitis may be an autoimmune process.

Animals↗
PubMed1993

Atypical adenomatous hyperplasia of the prostate: morphologic criteria for its distinction from well-differentiated carcinoma.

Atypical adenomatous hyperplasia (AAH) is a localized proliferation of small glands within the prostate that may be mistaken for carcinoma. To determine the diagnostic criteria for separating AAH from carcinoma, seven observers independently evaluated 54 selected lesions from 44 transurethral resection specimens. Three patterns of glandular proliferation were observed, all arising in association with nodular hyperplasia: AAH (38 foci), atypical small acinar proliferation of uncertain significance (eight foci), and well-differentiated carcinoma (eight foci). Of 24 architectural and cytologic features evaluated, the following were useful in separating these three patterns: variation in nuclear size (14%, 22%, and 25%, respectively), mean nucleolar diameter (0.69 micron, 1.43 microns, and 1.78 microns, respectively), largest nucleolar diameter (mean, 1.66 microns, 2.71 microns, and 2.81 microns, respectively), percentage of nucleoli greater than 1 micron in diameter (17.6%, 58.1%, and 77.5%, respectively), crystalloids within suspicious glands (16%, 13%, and 75%, respectively), luminal basophilic mucinous secretions, infiltrative borders, discontinuity of the basal cell layer in AAH (compared with complete absence in carcinoma; shown with basal cell-specific anti-keratin monoclonal antibody 34 beta E12 immunostaining), and intact basement membrane in AAH (compared with discontinuity in carcinoma; shown with type IV collagen immunostaining). Features that could not reliably separate AAH from carcinoma included lesion shape, circumscription, multifocality, average gland size, variation in gland size and shape, nuclear shape, chromatin pattern, and amount and tinctorial quality of cytoplasm. Although the biologic significance of AAH is uncertain, its light microscopic appearance and immunophenotype allow it to be distinguished from carcinoma in most cases.

Adenoma↗
PubMed1993

Prevalence of pseudorabies (Aujeszky's disease) virus antibodies in feral swine in Florida.

Serum samples collected from feral swine (Sus scrofa) throughout Florida (USA) from 1980 to 1989 were tested for antibodies to pseudorabies virus (PRV) by the serum neutralization test, the latex agglutination test, or by the enzyme-linked immunosorbent assay. Seropositive swine were detected at 11 of 13 sites with a composite seroprevalence of 34.8% (579 of 1,662 samples; range = 5.9% to 58.2%) for sites with seropositive swine. Data on age and sex of the swine were available from three sites. Seroprevalence in males and females did not differ significantly (P = 0.62 for the combined data). Seroprevalence in adult (> or = 8 mo) and juvenile swine (< 8 mo) was significantly different at all sites (P < 0.05 for the combined data). From these data, PRV infections appear to occur widely in populations of Florida feral swine and may seriously undermine efforts to eradicate this virus from the domestic swine population of the USA.

Age Factors↗
PubMed1993

Prevalence of Brucella sp. antibodies in feral swine in Florida.

Serum samples collected from feral swine (Sus scrofa) throughout Florida (USA) from 1974 to 1989 were tested for antibodies to Brucella sp. by the card test, the standard tube test, the rivanol test or the complement fixation test. Seropositive swine were detected at six of 18 sites with a composite prevalence of 23.4% (238 of 1,015 samples; range = 5.5% to 33.3%) for sites with seropositive swine. At one site for which age and sex data were available there was no significant difference (P = 0.50) in seroprevalence between males and females. Antibody prevalence in adult (> or = 8 mo) and juvenile swine (< 8 mo), however, was significantly different (P < 0.05). Based on these data, Brucella sp. infections are limited only to certain populations of feral swine. To avoid the spread of Brucella sp. organisms, however, relocation of feral swine is not recommended.

Age Factors↗
PubMed1992

Clonal origin of epithelial ovarian carcinoma: analysis by loss of heterozygosity, p53 mutation, and X-chromosome inactivation.

BACKGROUND: It has been suggested that multiple sites of epithelial ovarian carcinoma on the peritoneal surface reflect polyclonal disease arising from multiple primary tumors in the peritoneal mesothelium, rather than monoclonal disease spread by metastases from one primary ovarian cancer. PURPOSE: The purpose of this study was to investigate whether ovarian cancer has a monoclonal or polyclonal origin. METHODS: DNA specimens were obtained from peripheral blood lymphocytes (normal DNA) and from multiple tumor deposits of 17 women with epithelial ovarian carcinoma: primary tumors, metastatic deposits, and ascites. The clonal origin of each tumor was determined by performing (a) analysis to detect loss of heterozygosity at five loci on chromosomes 5, 11, 13, and 17; (b) sequencing of exons 5-8 of the p53 gene; and (c) X-chromosome inactivation analysis of the phosphoglycerate kinase (PGK) gene. RESULTS: In 15 of the 17 cases analyzed, there was clear evidence of monoclonal origin. The probability that the genetic events documented in these 15 cases occurred as independent events in each tumor deposit ranged from 2.5 x 10(-1) to 3.7 x 10(-16). In two cases, the pattern of allelic deletion and p53 gene mutation was compatible with either a monoclonal origin or origin from two primary ovarian tumors. CONCLUSIONS: The results did not support the hypothesis that ovarian cancer is a multifocal, polyclonal disease. Instead, the data suggest that sporadic epithelial ovarian carcinoma has either a monoclonal or a dual primary origin. IMPLICATIONS: These findings have important implications for understanding of the natural history of ovarian cancer and for clinical strategies aimed at prevention and early detection. Further studies will be required to determine the clonal origin of familial hereditary ovarian cancer.

Alleles↗
PubMed1992

Isolated traumatic accessory splenic rupture: a case report and literature review.

Although small and relatively protected, an accessory spleen can be the cause of acute intraabdominal symptoms following minimal trauma. Although a splenic fracture or laceration may not be apparent on by CT scan, the scan cannot rule out the possibility. The diagnosis of splenic injury should be entertained in light of appropriate history and physical findings. The case we present and prior similar cases are a useful review of isolated accessory splenic rupture due to blunt trauma.

Abdominal Injuries↗
PubMed1991

Carotid endarterectomy in a community hospital surgical practice.

Three hundred twenty-four carotid endarterectomies (CEAs) were performed on 303 patients over 5 years. Sixty per cent of the patients were symptomatic with completed stroke (36.4%), amaurosis fugax (35.4%) or transient ischemic attack (TIA) (50.5%). Some patients had multiple symptoms. Perioperative stroke occurred in four patients (1.2%) and 30-day mortality in five (1.5%). The combined stroke-mortality rate was 2.8 per cent. Other postoperative complications included TIA (1.9%), cranial nerve injury (3.1%), wound hematoma (6.5%), and hypertensive reperfusion syndrome (9.6%). Ten early reoperations were performed for wound hematoma (7) or technical problems (3). Follow-up of 284 CEAs (88%) at a means of 31 months revealed 33 late deaths, with two due to stroke. Late strokes occurred in 11 patients (3.9%). Five late strokes were ipsilateral (1.8%) and six were contralateral (2.1%) to the operated carotid artery. Ninety-seven carotid arteries were evaluated by duplex ultrasound scanning at a mean postoperative interval of 27.2 months. Ninety-two per cent had 0-30 per cent restenosis, 5 per cent had 40 per cent to 60 per cent restenosis and 3 per cent had 70 per cent or greater restenosis. The authors conclude that CEA can be performed with acceptable morbidity and mortality rates and that it is a durable operation that reduces the risk of late stroke.

Adult↗
PubMed1990

A simple method to improve the accuracy of non-invasive ultrasound in selecting TIA patients for cerebral angiography.

A prospective study is reported of the ability of B mode ultrasound imaging and continuous wave Doppler flow studies to detect different degrees of stenosis of the extracranial internal carotid artery (ICA) in 186 arteries in 99 patients with transient ischaemic attacks (TIA) and minor ischaemic stroke. A simple mathematical equation has been developed which combines the image and flow data to provide a single predictor of the degree of angiographic stenosis which has advantages over either ultrasonic modality used alone. The sensitivity and specificity of the predictive model in the detection of stenosis greater than or equal to 25% was 73% and 98%, of stenosis greater than or equal to 50% was 90% and 93%, of stenosis greater than or equal to 75%, 65% and 99% and occlusion 100% and 94% respectively. The principal clinical value of ultrasound screening is to spare patients with "non-significant" stenosis the risk of unnecessary angiography. Thus a simple measure of the Duplex screening tests' performance is the proportion of all strokes occurring as a complication of angiography that are avoided by changing the investigation policy from "angiograms for all carotid TIA and minor ischaemic stroke patients" to "angiograms for all patients with abnormal ultrasound results". If Duplex scanning were used to select patients most likely to have a significant abnormality on angiography, depending on the degree of stenosis to be detected, 52-85% of angiographic strokes might be avoided. If the predictive equation were used 62-88% of angiographic strokes might be avoided.

Blood Flow Velocity↗
PubMed1988

The ratio of prostate chips with cancer: a new measure of tumor extent and its relationship to grade and prognosis.

The ratio of chips with cancer to the total number of chips was studied in 118 patients with prostate cancer who underwent transurethral prostatectomy. We found that this ratio is a prognosticator closely associated to the stage of tumor (local or extensive) and to the chance of death from prostate cancer. Stage, the ratio of positive chips and the Gleason histologic score are all closely tied one to another, and it is unclear from this initial study whether these variables provide independent or additive prognostic information. Nevertheless, the ratio of positive chips shows far better interobserver agreement than does the Gleason score, and in patients with the most common predominant score of three, it can separate most of those with localized disease from most of those with extensive disease. Thus the ratio shows promise as a reliable predictor of stage of disease and of long-term failure, and hence it may help in the choice of patients for curative surgery.

Adenocarcinoma↗