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Biomedical subjects

K P Morrissey

Publications and source records attributed to K P Morrissey.

12 recordsLinked to original sources
PubMed1999

The effects of mesh bioprosthesis on the spermatic cord structures: a preliminary report in a canine model.

PURPOSE: The use of mesh bioprosthesis during inguinal herniorrhaphy is now considered routine. To our knowledge, no studies have examined the effects of mesh induced fibrosis on the structure and function of the adjacent spermatic cord. We present our experience in a canine model. MATERIALS AND METHODS: Unilateral inguinal hernia defects were created in 12 male beagle dogs. Half were repaired using Marlex mesh and half using a classic Shouldice technique. The inguinal anatomy was then re-examined at 6 and 12 months. Testicular temperature and volume, peripheral and testicular vein testosterone levels, testicular blood flow, vasography, testicular and cord histology, and sperm motility/morphology were recorded. Groups were compared with each other as well as to the non-operated (control) side. RESULTS: Although post-operative testicular volumes from both the mesh and Shouldice groups were similar to controls (p >0.05), there was a downward trend after mesh repair (17.8 cc pre versus 12.6 cc post) but this did not reach statistical significance (p = 0.17). Testicular temperatures and blood flow did not differ between experimental groups and controls. While testicular vein testosterone levels were significantly higher than peripheral venous levels after Shouldice repair, this difference was lost after mesh repair. Contralateral (control) testicular vein testosterone levels were higher in animals repaired with mesh than by an anatomic Shouldice repair (p <0.05). There was a significant decrease in cross sectional vasal luminal diameter in both the anatomic and mesh repair groups versus their respective contralateral controls (p <0.05). This was correlated with a marked foreign body reaction to the mesh in the soft tissues surrounding the vas in spermatic cords exposed to Marlex. All vasograms demonstrated patency. Gross pathology was abnormal in 3/6 dogs with mesh repair (2 hydroceles and 1 ischemic testis) and 0/6 animals after Shouldice repair. A traumatic neuroma was identified in the mesh group. Sperm morphology and motility did not differ between the two groups. CONCLUSIONS: Half of the testicles had gross abnormalities after mesh repair versus none in the control and Shouldice dogs. Although all vasograms were patent, vasal luminal size was significantly decreased with a marked soft tissue foreign body reaction identified after mesh repair. A traumatic neuroma was identified suggesting nerve entrapment in the fibrotic mesh reaction, which may account for post-operative pain seen in some patients. Marlex mesh may adversely affect spermatic cord structure and function and further work is required to fully elucidate its effects.

Animals↗
PubMed1989

DNA content of rectal scrapings from individuals at low and high risk for the development of colorectal cancer. A feasibility study.

Scrapings of superficial rectal mucosa were collected from 31 patients with colorectal carcinoma, 66 patients with sporadic adenoma, and 53 control subjects with no personal or family history of colorectal cancer. The DNA ploidy level and proliferative patterns of each specimen were analyzed by flow cytometry (FCM). A GMS index, calculated as the ratio of G2 + M:S, was found to be significantly lower in control subjects than in any of the high-risk groups studied. Aneuploidy was more prevalent in rectal scrapings from cancer patients and adenoma patients than in those from control subjects. Aneuploid cell populations were detected in apparently normal rectal scrapings from two control subjects. Some high-risk individuals (i.e., cancer patients and patients with adenomas and a family history of cancer) exhibited higher proportions of tetraploid (designated G2/M) cells and a higher G2/M:S phase ratio than control subjects. The results accumulated thus far show that the rectal scraping procedure is safe and easy to perform. Our limited findings give hope that the DNA content analysis of cells obtained by rectal scraping may eventually prove useful in mass screening for colorectal cancer risk. However, definitive evaluation will require further refinement and elaboration of analytic technique and testing on more patients at various levels of predetermined risk.

Adenoma↗
PubMed1977

Biliary lipid metabolism in the pregnant baboon.

The serum cholesterol value, bile acid pool size and kinetics as well as lipid composition of gallbladder bile have been studied in seven baboons during nine pregnancies. During pregnancy, the per cent decrease in the average serum cholesterol value ranged from 25.6 to 74.4 per cent, mean 54.5 +/- 14.3 per cent, compared with that of antepartum averages. In seven of the nine pregnancies, chenodeoxycholic acid pool size decreased in the range of 40.1 to 86.6 per cent. In two pregnancies, the pool size of this bile acid was essentially unchanged. Total bile acid pool size also decreased from a mean of 990 +/- 260 milligrams antepartum to 520 +/- 200 milligrams in the third trimester, p less than 0.01. With regard to the cholesterol, phospholipid and bile salt content of gallbladder bile, cholesterol value decreased from an antepartum mean of 19.1 +/- 3.9 to 14.1 +/- 4.5 micromoles per milliliter in the third trimester. As a consequence, the lithogenic index of gallbladder bile decreased during pregnancy. The changes in chenodeoxycholic and total bile acid pool size are qualitatively similar to those reported by other investigators following the administration of estrogens to both baboons and other animal species. In the pregnant baboon, the decrease in pool size and in synthesis rate of bile acids is accompanied by a decrease in the cholesterol content of gallbladder bile. These changes in the lipid content of gallbladder bile are reflected in a decrease in the mean lithogenic index. These data suggest that the baboon may be an inappropriate model for studies of the relationship of pregnancy to cholesterol cholelithiasis in humans. In the baboon, both serum and biliary cholesterol values decrease during pregnancy. In humans, serum cholesterol levels increase during pregnancy. If the content of biliary cholesterol is a reflection of the serum concentration of this lipid, as has been suggested in recent studies, human bile may be more lithogenic during pregnancy. Additional studies are necessary to define the role of gallbladder contractility and bile stasis to gallstone formation during pregnancy.

Animals↗
PubMed1976

Chenodeoxycholic acid induced liver injury in pregnant and neonatal baboons.

The prolonged feeding of chenodeoxycholic acid produces hepatic injury in both pregnant and non-pregnant baboons. CDC feeding does not adversely affect ovarina function and no teratogenic effects of this bile acid were noted in 16 live birth and two stillborn progeny of CDC fed animals. However, 10 of the 16 live birth neonates and one stillborn had focal hepatic lesions histologically similar to those observed in the adult animals. In addition one neonate had gross hepatic necrosis. The severity of the liver damage was related to the content of lithocholic acid in the bile of both the neonates and their mothers. Experiments with 14C-chenodeoxycholic and 14C-lithocholic acid demonstrate that the lithocholate in the enterohepatic circulation of the neonate is derived from the CDC fed to the pregnant adult. In the gallbladder bile of the neonate most, but not all, of the lithocholate is conjugated but unsulfated. Both newborn and adult baboons sulfate lithocholic acid but to an extent less than that reported for man. Less efficient sulfation of lithocholic acid in the baboon may exaggerate the toxicity of CDC feeding in this species compared to man. Nevertheless, the potential for adverse effects on the fetal liver must be recognized as a risk associated with the use of chenodeoxycholic acid in women of child-bearing age.

Animals↗
PubMed1975

Toxicity of chenodeoxycholic acid in the nonhuman primate.

Toxicologic aspects of long-term therapy with the gallstone-dissolving agent, chenodeoxycholic acid (CDC) are under study in the baboon. Eighteen animals, subdivided into low (20 mg. per kilogram per day), incremental (18 to 38 mg. per kilogram per day), and high (38 mg. per kilogram per day) dose groups were fed CDC daily for 8 to 15 months. During that period they maintained on appearance of excellent, unchanged health and behavior indistinguishable from that of eight control animals. However, 15 of the 18 CDC-fed animals showed significant elevations of monthly serum glutamic pyruvic transaminase-serum glutamic oxalacetic transaminase determinations, and 14 of the 18, from all dose groups, developed significant focal histologic changes in serial liver biopsies. Histologic changes are similar to those described for lithocholic acid toxicity and correlate with an elevated percentage of chenodeoxycholic acid and, particularly, with lithocholic acid (8 to 14 percent) in gallbladder bile of the CDC-fed animals. A few CDC-fed animals showed histologic changes without enzymatic changes and vice versa. To date none of the focal hepatic lesions appears irreversible; it is too early to determine whether continued CDC feeding results in progression, stabilization, or regression of changes. More intensive surveillance of human subjects receiving chenodeoxycholic acid is indicated.

Alanine Transaminase↗
PubMedDate not supplied

Appendiceal CT in 140 cases. Diagnostic criteria for acute and necrotizing appendicitis.

Computed tomography (CT) was performed in 140 patients with suspected acute appendicitis. Thin collimation (5 mm), intravenous contrast enhancement, 1-second scan times, and supplementary cecal air insufflation were emphasized. CT accuracy was 98% overall (137/140), and 99% in the 124 cases with early surgery. Necrotizing appendicitis was diagnosed by CT with 86% accuracy and 90% positive predictive value.

Acute Disease↗