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Biomedical subjects

J D Hamilton

Publications and source records attributed to J D Hamilton.

At least 109 records · Page 6Linked to original sources
PubMed1979

Anti-self HLA may be clonally expressed.

A monolayer absorption technique was used to test the hypothesis that killer cells directed to self HLA-associated minor histocompatibility antigens (H-Y) were divisible into subsets. The results showed that sensitized killer cells, which recognized two combined antigens HLA-A2; H-Y and HLA-B7; H-Y could indeed be divided into two populations. One was directed to HLA-A2; H-Y and the other to HLA-B7; H-Y. These results can be interpreted in the context of the altered self hypothesis. However, when interpreted in the context of the dual recognition hypothesis, they strongly suggest that independant clones of killer T cells exist which are committed to the recognition of self HLA.

Autoimmune Diseases↗
PubMed1978

Small-bowel malabsorption and gastrointestinal malignancy.

In addition to lymphoma, there is an increased incidence of gastrointestinal carcinoma in patients with malabsorption due to celiac disease. This is frequently manifested by a loss of response to gluten withdrawal. Four such cases are described: one patient had lymphoma and the other three had cancer of the esophagus, jejunum, and pancreas, respectively. The literature indicates that carcinoma of the esophagus and small bowel is particularly common in patients with celiac disease. These findings suggest that celiac disease should be considered a premalignant condition and that such patients should undergo a regular radiographic survey to detect early cancer.

Aged↗
PubMed1978

Hemolytic anemia in patients receiving sulfasalazine.

Hemolytic anemia is a well-recognized complication of sulfasalazine treatment. 17 of 40 (43%) patients with inflammatory bowel disease receiving sulfasalazine had evidence of hemolysis as detected by starch gel electrophoresis. Only 47% (8) of patients with hemolysis had Heinz body formation. The hemoglobin was significantly reduced in patients with hemolysis and 53% had a reticulocyte count of greater than 5%. A significant correlation was noted between hemolysis and serum sulfapyridine level, but no correlation was seen with serum sulfasalazine level. There was no significant difference in disease extent or activity in patients with hemolysis compared to those without hemolysis. Hemolysis is not a rare side-effect of sulfasalazine therapy. Heinz body formation is not invariably found in sulfasalazine-induced hemolysis.

Anemia, Hemolytic↗
PubMed1978

Viral infection-homograft interactions in a murine model.

The effects on some host defenses of murine cytomegalovirus (MCMV) and(or) EL(4), a mouse ascites homograft, were studied in mice. Assays of cellular and humoral immunity in response to either or both of these perturbations were carried out by quantitation of various immune activities.Limited studies demonstrated no effect of EL(4) inoculation on the host response to MCMV by organ viral titer, duration of viral persistence, or anti MCMV complement-fixing antibody titer. Prior infection with MCMV, however, resulted in greatly reduced numbers of splenocytes, the source in this study of immune effector cells. Residual splenocytes demonstrated less response to both phyto-hemagglutinin and lipopolysaccharide, particularly in the 2-3-wk interval after infection. Similarly, responder cells in mixed lymphocyte cultures were less reactive when derived from infected animals. Lymphocyte-mediated cytolysis of EL(4) was significantly less in mice infected on the day of and 7, 14, and 21 days before the tumor homograft with a return to control levels by 28 days. 90% of the cell-mediated cytolysis could be eliminated by treatment with anti-theta serum. Serum-mediated cytolysis of EL(4) was also reduced in infected animals. No suppressor cells or serum inhibitory factors could be identified in infected animals. Although alternative explanations exist, this study suggests that in infected animals there is a significant reduction in both the number and function of bone marrow-derived and thymus-derived cells directed against the alloantigens in EL(4).

Animals↗
PubMed1978

The clinical librarian and the patient: report of a project at McMaster University Medical Centre.

In June 1975 a clinical librarian project was initiated in the Gastroenterology Programme of McMaster University Medical Centre. The objectives of the project were to assist patients in participating more knowledgeably in their own health care and to assist health professionals in applying the latest information from biomedical literature to patient care. The implementation and development of the service are described, including the use of feedback from patients and health professionals to assess the impact of the librarians' participation in clinical settings. Benefits included: 1) increased accessibility of information resources to patients, 2) a greater awareness by health professionals of the usefulness of biomedical literature and the library in patient care, and 3) an opportunity for the librarian to gain a first-hand view of activities and information needs in a clinical setting. Key points in determining the successful implementation of the project are given.

Canada↗
PubMed1977

"Blood and guts": one component of an integrated program in biologic sciences as applied to medicine.

The 3-year medical school program at McMaster University encourages an approach to learning a physician can apply throughout his or her career. The program has four phases and provides early exposure to relevant clinical material. In phase 3, the basic science phase, the structure and function of organ systems in health and disease are studied. Understanding the mechanisms of disease in order to be able to relate clinical symptoms and signs to physiologic and pathologic processes is emphasized. The four 10-week units deal with groups of organ systems. The "blood and guts" unit teaches the student hematology and gastroenterology through a variety of problem-based methods. Specialists in the relevant scientific disciplines influence selection and construction of the problems presented. The students are evaluated by the faculty tutor on their accomplishment of specific objectives related to their competence in solving biomedical problems.

Curriculum↗
PubMed1977

A preparatory course for medical students who lack a conventional academic background.

McMaster University School of Medicine admits students who may not have had an extensive education in physics, chemistry, and biology. For several years a short preliminary course was offered to those students. The course has since been discontinued, and its objectives have been incorporated into the M.D. program. This approach has been taken in an attempt to conform to the educational policy of the program. However, since the course was seen to be highly successful and, therefore, may be of use to others, its objectives and teaching methods are described.

Biology↗
PubMed1977

Effects of cold exposure and dehydration on renal function in black-tailed prairie dogs.

Black-tailed prairie dogs (Cynomys ludovicianus) were deprived of food and water for several weeks during the fall and winter in a cold-room hibernaculum (Ta 5-8 degrees C), and for several days at room temperature during the summer. Body temperatures (Tb) were determined periodically in nine animals by radiotransmitters implanted in the abdomen. Animals deprived of food and water in the summer were killed when maximum urine concentration was achieved. Eight animals in the winter were active when killed after 7-35 days in the hibernaculum with Tb between 18 and 36 degrees C. Five animals that became torpid periodically in the winter were killed after 19-42 days in the hibernaculum when their Tb indicated torpor (Tb less than 13 degrees C). Active animals in the summer and winter possessed pronounced renal corticomedullary urea and sodium concentration gradients. Torpid animals lacked these gradients and had lower urine and plasma osmotic concentrations than active animals. Plasma urea values and terminal osmolal U/P ratios were lowest in torpid prairie dogs.

Animals↗
PubMed1977

Persistence of proctitis in 2 cases of clindamycin-associated colitis.

Two cases of persisting proctitis after an episode of clindamycin-associated colitis are reported. Both patients had fulminant colitis and required emergency operation. Severe proctitis persisted in the rectal stumps until their removal 8 months after the initial diagnosis of colitis was made. Persisting proctitis has not previously been described in clindamycin-associated colitis.

Adult↗
PubMed1976

Transmission of hepatitis B by a human bite: an occupational hazard.

Hepatitis B developed in a policeman 15 weeks after he was bitten on the hand. A few days after the bite hepatitis B developed in the assailant. The bite had drawn blood and this method of inoculation was presumed to be the route of transmission of the virus. Compensation was awarded on the grounds that this was an occupationally acquired disease.

Adult↗
PubMed1976

Role of gluten, prednisone, and azathioprine in non-responsive coeliac disease.

A case of severe "non-responsive" coeliac disease has been shown to be sensitive to gluten whilst under prednisone therapy, but not without prednisone. This adds an additional dimension to the criteria for diagnosis of coeliac disease. Cases of non-responsive coeliac disease may require both prednisone and gluten exclusion to induce a remission. In this patient, azathioprine induced and sustained a remission when unacceptably high doses of prednisone had failed, and may prove to be a valuable immunosuppressive in non-responsive coeliac disease.

Administration, Oral↗
PubMed1976

Paecilomyces varioti endocarditis on a prosthetic aortic valve.

Fungal endocarditis following prosthetic valve surgery has assumed increased importance as a cause of postoperative death. We present, to our knowledge, the first case of the fungus Paecilomyces varioti producing endocarditis on a prosthetic aortic valve. This seems to be an extremely indolent organism which exhibits an apparent response to antibiotic therapyl. In vitro evidence suggests that this fungus is sensitive to attainable serum levels of both 5-fluorocytosine and amphotericin B. However, after viewing the extracted valve and the devastating embolic phenomenon in our patient, we believe that medical therapy alone would not suffice. Thus we suggest that prompt valve replacement be performed in future cases.

Aortic Valve↗
PubMed1975

Combined activity of amphotericin B and 5-fluorocytosine against Cryptococcus neoformans in vitro and in vivo in mice.

The in vitro and in vivo activities of amphotericin B and 5-fluorocytosine (5-FC) alone and in combination were studied to determine possible drug interactions against two strains of Cryptococcus neoformans, one sensitive to 5-FC and one resistant to 5-FC. In vitro tube dilution studies demonstrated only additive effects with the 5-FC-sensitive organism but antagonism with eth 5-FC-resistant organism. A mouse model of cryptococcal meningitis allowed comparative drug trails in a new model for the detection of drug interactions. Drug combinations were no more effective against meningitis caused by the 5-FC-sensitive organism than the additive effects of the individual drugs. However, meningitis caused by the 5-FC-resistant Cryptococcus responded less to drug combinations than to either drug alone. Serum levels of amphotericin B and 5-FC were comparable in all groups. No evidence of toxicity from the drug combinations was found. No inhibition of development of resistance to 5-FC by the combination with amphotericin B was detected.

Amphotericin B↗
PubMed1975

Fungal infection following renal transplantation.

Twenty-seven deep fungal infections developed in 22 of 171 patients following renal transplantation. These infections included cryptococcosis (ten), nocardiosis (seven), candidiasis (four), aspergillosis (two), phycomycosis (two), chromomycosis (one), and subcutaneous infection with Phialophora gougeroti (one). Twelve infections occurred in living-related and ten in cadaveric recipients. Nineteen of the 22 patients were male. Infections occurred from 0 to 61 months after transplantation. Complicating non-fungal infections were present concomitantly in 15 patients. Thirteen patients died, eight probably as a result of fungal infection. Appropriate diagnostic procedures yielded a diagnosis in 20 of 27 infections, and therapy was begun in 18 patients. Serologic, culture, and biopsy procedures useful in making rapid diagnoses are advocated in the hope of increasing survival.

Adolescent↗