Biomedical subjects
J D Hamilton
Publications and source records attributed to J D Hamilton.
Thioridazine retinopathy within the upper dosage limit.
Explore the source record for details and available documents.
Reactivation of latent murine cytomegalovirus from kidney.
Cytomegalovirus (CMV) is presumed to cause latent infection, but the sites of infection are incompletely known. We propose that latent murine cytomegalovirus is present in kidney and may be reactivated by explanation. Immunosuppressive agents and allogeneic stimuli may enhance this process. Balb/c mice were infected 11 to 14 months previously with 10(5) pfu of Smith strain murine cytomegalovirus intraperitoneally. Kidneys from 15 infected and nine uninfected mice were washed, minced into 1 to 2 mm2 explants and placed into separate tissue culture wells containing a mouse embryo fibroblast monolayer. Explants were untreated or treated with azathioprine, cyclophosphamide, anti-thymocyte serum, or allogeneic lymphocytes. Daily observations for CPE and passage of supernatant to fresh mouse embryo fibroblast were done. Standard cultures of blood, kidney, and salivary gland were negative. However, virus was isolated from the explants of 8/15 animals, with a reactivation time of 30 to 70 days. No significant difference in reactivation time was noted between treated or untreated explants. Restriction enzyme analysis of viral DNA confirmed identity with the original strain. These data show that latent murine cytomegalovirus is present in murine kidney tissue and may be reactivated by explantation.
The source of murine cytomegalovirus in mice receiving kidney allografts.
The sources of cytomegalovirus (CMV) infection in kidney transplant recipients include reactivation of latent endogenous virus in the recipient or reactivation of latent virus in donated blood or kidney. In the present study, kidneys from mice latently infected with one strain of murine CMV were transplanted into either uninfected recipients or recipients latently infected with a different strain of murine CMV; the recipients were immunosuppressed, subsequently were cultured for murine CMV, and the infecting strain was characterized. The results show that reactivation of latent murine CMV from the donated kidney can be the source of active infection in previously uninfected recipients. When the recipient had been previously infected, however, reactivation of the endogenous recipient strain of murine CMV was the source of active infection in 10 of 12 instances. At no time were both exogenous and endogenous strains of virus reactivated simultaneously. These studies indicate that donor kidney may be the source of latent virus in the uninfected recipient but that endogenous virus predominates in previously infected recipients.
Transmission of latent cytomegalovirus in a murine kidney tissue transplantation model.
This paper examines the hypothesis that latent murine cytomegalovirus (MCMV) may be transmitted in kidney tissue to transplant recipients. Balb/c mice were infected with MCMV, and at intervals of less than 1 week to greater than 1 year, transmission of the virus from infected donors was attempted by transplantation of kidney sections or transfusion of blood into uninfected recipients. Graft recipients were killed from 2-4 weeks later, and cultured for MCMV. Restriction endonuclease digestion profiles of viral DNA were performed. Acutely infected donors transmitted MCMV in kidney tissue to 83-66% of untreated, susceptible recipients. Latently infected donors transmitted the infecting strain of virus to 20% of all and 31% of immunosuppressed recipients but to 37% of the syngeneic versus 21% of the allogeneic (P less than .027). Blood transfusions transmitted latent virus to 28% of recipients. In conclusion, kidney tissue may serve as the source of latent virus in this murine transplantation model. Retained blood in the kidney is unlikely to be the only source of virus.
Pseudo-posttraumatic stress disorder.
Explore the source record for details and available documents.
Nonurban male homosexuals: epidemiologic, immunologic and virologic characteristics.
Twenty asymptomatic male homosexuals living in North Carolina were evaluated looking at epidemiologic, immunologic and virologic characteristics. In ten subjects selected for inhalant nitrite use a significantly higher frequency of multiple drug abuse and a trend toward greater sexual promiscuity was found in comparison with ten nonnitrite users. None of the 20 subjects had chronic lymphadenopathy. Cytomegalovirus (CMV) was not found in urine, blood or throat washings, but was found in 29% of the subjects' semen specimens--a finding that was significantly linked (P less than .05) to the presence of CMV IgM antibody in serum. There were no abnormal helper lymphocytes: suppressor T lymphocyte ratios (all greater than 1.3) and lymphocyte mitogen stimulations were not different from heterosexual controls in contrast to frequent abnormalities reported in male homosexuals in metropolitan areas. If these immunologic findings are reproducible, they may be important in understanding why the Acquired Immunodeficiency Syndrome has clustered in large cities.
Non-A, non-B hepatitis and chronic dialysis--another dilemma.
To define the incidence of non-A, non-B (NANB) hepatitis and evaluate possible risk factors, we reviewed records of 163 patients on chronic dialysis during a 3-year period. 23 cases of NANB hepatitis occurred, 13 (27%) in 49 center dialysis, 8 (10%) in 77 home hemodialysis (p less than 0.02) and 2 (5%) in 37 peritoneal dialysis patients (p less than 0.01). Hepatitis patients received significantly more transfusions than controls. Numbers of transfusions and of patients transfused were not significantly different in center patients compared to home and peritoneal. 8 NANB patients received no transfusions. NANB was the most common cause of hepatitis in our unit (68%). Although transfusions were a likely etiologic factor, to explain the increased risk in center dialysis patients, disease in patients not transfused and development of NANB hepatitis without a known parenteral exposure in a physician assigned to the Nephrology Service, we feel another etiologic factor was important, the dialysis center.
Hepatitis B virus vaccine. An analysis of its potential use in medical workers.
At the Duke University Medical Center, Durham, NC, there are approximately ten recognized hepatitis B virus (HBV) infections per year in employees. The hospital's hepatitis control program costs $91,995 per year, including costs for workman's compensation, hyperimmune globulin, laboratory tests, lost revenue, liability, personnel, and medical treatment. A program to immunize high-risk medical center personnel and to accommodate residual HBV problems in nonimmunized employees would cost $206,304 in the first year. By seven years the cumulative costs of an immunization program would equal those without a program and at ten years would be cost saving ($746,742 with program v $919,950 without a program). Given certain assumptions, HBV vaccine is a cost-beneficial alternative for a major employee health hazard.
Hepatitis B surface antigen could harbour the infective agent of AIDS.
Explore the source record for details and available documents.
Esophageal tuberculosis: findings on barium swallow and computed tomography.
Esophageal tuberculosis secondary to tuberculous mediastinal lymphadenopathy is a very unusual presentation of adult tuberculosis. We report a patient presenting with fever of unknown origin and dysphagia. Barium swallow demonstrated esophageal displacement, mucosal ulceration and perforation with a fistulous tract into the mediastinum. CT of the mediastinum gave the most complete delineation of the tuberculous mediastinal lymphadenopathy which surrounded and displaced the esophagus. The fistulous tract extending from the esophagus into the nodal mass was also seen on CT.
Brain abscess caused by a variety of cladosporium trichoides.
A brain abscess caused by a new variety of Cladosporium trichoides occurred in a previously healthy man. A reversed T-suppressor/helper cell ratio was noted as the only immunologic abnormality. He required three surgical procedures, the last an occipital lobectomy, and antifungal chemotherapy to control his disease. He received 2,068 mg of amphotericin B and one year of flucytosine at 6 g per day. Ten months after the last surgery he is without evidence of disease. C. trichoides var. chlamydosporum was isolated from the abscess. It differed from C. trichoides by producing chlamydospores in vitro and only hyphae in the brain abscess. On modified Sabouraud agar, the fungus did not grow at 25 degrees C and grew poorly at 30 degrees C and 37 degrees C. Histologic sections revealed necrosis, no encapsulation, and no epitheliod cells.
Possible tobramycin delirium.
Explore the source record for details and available documents.
Failure of ketoconazole in cryptococcal meningitis.
Explore the source record for details and available documents.
Inadequate sensitivity of tuberculin tine test for screening employee populations.
Tuberculin Tine and Mantoux skin tests were simultaneously applied to opposite arms of 1,065 medical center employees during their usual preemployment and annual health examinations for the purpose of evaluating the Tine test sensitivity. Of 829 skin tests read, 39 (5%) were positive by the Mantoux method. Tine tests were positive in 27 of the 39: a sensitivity of 69% and a false-negative rate of 31%. In view of these results, the tuberculin tine test is not sensitive enough and is not indicated for employee screening programs when finding tuberculosis infection, and not disease, is the primary goal.
Acquired cytomegalovirus retinitis. Four new cases and a review of the literature with implications for management.
49 cases of acquired cytomegalovirus retinitis were reviewed including three new cases in renal allograft recipients and one in a patient with Hodgkin's Disease. Diagnosis in over 90% of cases was based on the distinctive funduscopic appearance of cytomegalovirus (CMV) retinitis. When performed, urine, subretinal fluid, and blood buffy coat cultures were positive for CMV in 97, 67 and 39% of cases, respectively. More than two-thirds of these patients were organ transplant recipients who received chronic immunosuppressive therapy. Attempted therapy of CMV retinitis with a variety of regimens has not been proven to be effective. At present, no specific treatment is recommended unless it is given under a controlled therapeutic trial.
Hepatitis B in a medical center.
The Employee Health Service of Duke University has been evaluating all employees with known blood product exposures through a standardized protocol since January 1977. All known cases of hepatitis B among employees were also evaluated. During the 40-month period of this report, 1,235 substantiated blood product or body fluid exposures occurred. The blood involved in 155 of the exposures was positive for HBsAg. Of the 155 employees involved in these exposures, 101 were found to be nonimmune to hepatitis B and were followed for at least nine months after exposure. Three (3.0%) developed clinical hepatitis B. An additional 24 employees also developed hepatitis B during this 40-month period, a cumulative incidence of 106.0 per 100,000 employee years. Hepatitis B appears to be a significant occupational hazard for hospital personnel in a tertiary medical center.