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Biomedical subjects

B McGregor

Publications and source records attributed to B McGregor.

32 records · Page 2Linked to original sources
PubMed1992

Liver transplantation for erythropoietic protoporphyria. Report of a new case with subsequent medium-term follow-up.

We report a new case of successful liver transplantation in a 36-year-old patient with terminal hepatic failure due to erythropoietic protoporphyria. Data regarding protoporphyrin levels in erythrocytes and feces, before and after transplantation, seem to indicate that in this case protoporphyrin overproduction was in part due to liver synthesis. Four years after surgery, the patient is completely free of skin photosensitivity. His liver function tests are normal; there are no visible protoporphyrin deposits or ultrastructural abnormalities in his new liver. However, recurrence of the disease in the long term cannot be excluded, since erythrocyte protoporphyrin levels remained elevated after liver transplantation.

Adult↗
PubMed1990

Association of human papillomavirus and colon neoplasms.

Human papillomavirus has been shown to be associated with squamous carcinomas. We evaluated benign and malignant colon tissues for the presence of human papillomavirus infection to determine if a similar relationship exists between human papillomavirus and colon neoplasms. Colon tissues were screened using an immunohistochemical technique to detect human papillomavirus antigen. In situ DNA hybridization was then performed on those tissues that yielded positive results by immunohistochemistry. Groups were compared using chi 2 analysis. Human papillomavirus antigen was present in 23% of normal colon specimens, 60% of benign tumors, and 97% of carcinomas. Human papilloma viral genome was demonstrated in 27% of benign tumors and in nearly 43% of all carcinomas tested. These data indicate that human papillomavirus infects the columnar mucosa of the colon, and that an association exists between human papillomavirus and colon neoplasia.

Adenoma↗
PubMed1990

Immunohistochemical demonstration of human papilloma virus antigen in human colon neoplasms.

The presence of human papilloma virus (HPV) has recently been demonstrated in colon tumors, but the incidence of HPV infection in normal colon mucosa or in benign or malignant neoplasms of the mucosa is unknown. We studied both neoplastic and normal human colon tissue for the presence of HPV antigen using immunohistochemical techniques. Ninety colon specimens were studied. Three consecutive series of normal colon mucosa (N = 30), single benign tubulovillous adenomas (N = 30), and invasive carcinomas (N = 30) were selected and confirmed histologically. Formalin-fixed paraffin-embedded samples of each tissue were prepared using immunohistochemical techniques and resultant slides were read blindly and graded simply as positive or negative for HPV antigen. The presence of HPV antigen varied dramatically between groups, with 97% of the invasive carcinomas, 60% of the benign tubulovillous adenomas, and 23% of the normal mucosa positive for HPV antigen. Groups were statistically significant using chi 2 analysis (P less than 0.001). We conclude that an association exists between the human colon neoplasia and the presence of HPV antigen. This may suggest an etiologic role of the virus in colon cancer.

Adenoma↗
PubMed1990

Ethanol diffuses across the gastric muscle wall.

Ethanol inhibits the electrical and mechanical activities of gastric smooth muscle, but only at concentrations higher than can be provided by serum delivery. We speculated that the ethanol concentration in the gastric wall may exceed plasma levels by direct diffusion across the mucosa and through the muscle layers. A model of acute ethanol ingestion was created by partitioning the stomachs of three dogs with a surgical stapling device and instilling carbon 14 (14C)-labeled ethanol into the proximal segments. The flux of ethanol was traced by counting 14C in serial sections of the gastric wall. A mucosa-to-serosa gradient of 14C activity was established. The data indicate that direct diffusion from the mucosal surface will produce dramatically higher concentrations of ethanol in gastric muscle than would be anticipated from serum levels alone.

Animals↗
PubMed1989

Effects of enteric neural stimulation on chloride transport in human left colon in vitro.

Nonpathological segments of muscle-stripped left colon from patients undergoing surgery for carcinoma, diverticulitis, or other causes were set up in flux chambers in order to determine the influence of intrinsic neurons on ion transport. In the basal state, both sodium and chloride were actively absorbed, and there was no significant residual ion flux. Electrical field stimulation of the intrinsic mucosal innervation evoked an increase in short-circuit current that was dependent on stimulus frequency and strength. The response was mimicked by scorpion venom, which is known to depolarize neurons, and was nearly abolished by tetrodotoxin, which prevents neurotransmitter release. Atropine reduced, but did not abolish, the response to neural stimulation. Carbachol, aminophylline, and theophylline significantly increased short-circuit current above basal levels. Electrical field stimulation evoked an increase in short-circuit current that could be accounted for by a decrease in net chloride absorption without any significant effect on sodium absorption or residual ion flux. These results suggest that ion transport in the human left colon is regulated by intrinsic submucosal cholinergic neurons as well as other neuronal types, and activation of these nerves could provide the basis for certain diarrheal disorders.

Aged↗
PubMed1989

Inguinal herniation justifies sigmoidoscopy.

Controversy exists concerning the association of inguinal hernia and colonic carcinoma and, more specifically, whether the development of an inguinal hernia justifies sigmoidoscopy. To study the role of endoscopic screening in cases of inguinal hernia, we prospectively evaluated 464 patients with inguinal hernia over a 54-month period with flexible sigmoidoscopy. Each patient was over the age of 40 and male. Sigmoidoscopy documented polyps (97 patients, 21 percent) and carcinoma (22 patients, 5 percent). Multiple neoplasms were observed in 6 percent (7 of 119 patients). Occult blood was detected in the fecal specimens of 8 percent of the total group of patients, but in only 13 percent of the patients with polyps or carcinomas. A normal examination occurred in only 38 percent of the total group. By using the presence of an inguinal hernia in patients older than 40 years of age as an indication for sigmoidoscopy, we found that more than one of every four patients had an asymptomatic, concurrent malignant or premalignant colonic lesion. Flexible sigmoidoscopy should be used for screening colonic neoplasms in patients with inguinal hernia.

Adult↗
PubMed1986

Optimal fluid management after aortic reconstruction: a prospective study of two crystalloid solutions.

To determine optimal fluid management after elective aortic surgery we compared postoperative administration of 5% dextrose Ringer's lactate solution (102 patients) with 5% dextrose half-normal saline solution (80 patients). For 72 hours after operation, intravenous fluids were titrated to maintain urine output between 50 and 100 ml/hr. The group receiving 5% dextrose Ringer's lactate required less intravenous volume per day (2005 +/- 138 ml [mean +/- standard error of the mean] vs. 2701 +/- 145 ml, p less than 0.05), gained less weight (0.8 +/- 0.2 kg vs. 3.2 +/- 0.2 kg, p less than 0.05), and sustained less hyponatremia (serum sodium reduction, 0.1 mEq/L vs. 4.5 mEq/L, p less than 0.05). The group receiving 5% dextrose Ringer's lactate exhibited consistently lower pulmonary capillary wedge pressure (7.3 +/- 1.0 mm Hg vs. 11.4 +/- 1.9 mm Hg) and required treatment for fluid overload in 9 of 102 instances compared with 30 of 80 instances with hypotonic saline solution (p less than 0.05). The patients receiving 5% dextrose Ringer's lactate maintained higher arterial PO2 at 40% forced inspiratory oxygen (PaO2, 83 +/- 3 torr vs. PaO2, 67 +/- 5 torr, p less than 0.05). Optimal fluid management was approached by the use of 5% dextrose Ringer's lactate solution postoperatively. The use of hypotonic saline solution after aortic surgery offered no advantage and predisposed the patient to volume overload.

Aortic Diseases↗
PubMed1980

Motor neurone disease with elevated cerebrospinal fluid protein.

The correlation between age and CSF protein in 38 patients with pathologically proven motor neurone disease was the reverse of that described for normal subjects by Tibbling et al in 1977. Eight had CSF protein ranging from 0.75 g/1 to 1.52 g/L. These patients were younger, but other clinical and gross and light microscopy pathological features were not significantly different from those with lower CSF protein. Transudation from serum may be only one of the mechanisms underlying this elevation in CSF protein.

Adolescent↗
PubMed1978

The role of bone scanning in the assessment of prostatic carcinoma.

Fifty new cases of carcinoma of the prostate were assessed prior to treatment to determine the incidence of bony metastases. The radioisotope bone scan was the most sensitive method of detecting metastases and of localising them. It was twice as accurate as the serum acid phosphatase estimation. Skeletal X-rays were the least accurate method. Forty-six per cent of patients had abnormal bone scans at presentation. The histological grade of the tumour correlated well with the bone scan. The higher the grade, the more likely was the bone scan to be abnormal. There is need for greater accuracy in detecting metastases, and the bone marrow acid phosphatase estimation, either alone or in conjunction with the bone scan, may provide this accuracy.

Acid Phosphatase↗
PubMedDate not supplied

Kidney preservation with IGL-1 solution: a preliminary report.

The University of Wisconsin (UW) solution is the most commonly used preservation solution. However, a new preservation solution-IGL-1-contains an inversion of K and Na concentrations and substitution of polyethylene glycol for hydroxyethyl starch in the UW solution. The present study is the first clinical experience on the outcome of kidneys preserved in IGL-1 solution. From June 2003 to June 2004, 119 cadaveric kidneys were retrieved and stored in IGL-1 solutions; among the 119 organs, this study includes 37 IGL-1-preserved kidneys that were locally transplanted versus 33 kidneys stored in University of Wisconsin (UW) solution that were also locally transplanted. The groups were comparable with regard to donor and recipient characteristics. Renal function outcome was evaluated by comparing delayed graft function (DGF) rates, the evolution of serum creatinine, daily urine output, and creatinine clearance. Biopsies were performed after reperfusion to evaluate apoptosis. The incidence of DGF was 5.71% among IGL-1 kidneys and 13.79% among UW kidneys. Creatinine values were significantly lower among the IGL-1 group from 2 to 14 days postoperative and at 1 month. Daily urinary output did not show any significant differences between the two groups. IGL-1 kidneys had a superior creatinine clearance during the first 15 postoperative days compared to UW kidneys. Kidneys preserved in IGL-1 solution showed fewer apoptotic cells compared to kidneys preserved in UW solution. This preliminary report suggests a superiority of IGL-1 for the immediate outcome of transplanted kidneys.

Adenosine↗