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Biomedical subjects

J A Stewart

Publications and source records attributed to J A Stewart.

At least 19 recordsLinked to original sources
PubMed1979

Controlled clinical trial of prophylactic human-leukocyte interferon in renal transplantation. Effects on cytomegalovirus and herpes simplex virus infections.

A double-blind, placebo-controlled trial of interferon prophylaxis against viral infections was conducted in renal-transplant recipients receiving standard immunosuprressive therapy with or without antithymocyte globulin. Interferon was administered for six weeks, beginning on the day of transplantation. Cytomegalovirus excretion began earlier and viremia was more frequent in placebo-treated than in interferon-treated patients. Cytomegalovirus viremia correlated with clinical syndromes was more frequent in recipients of antithymocyte globulin. In contrast, neither interferon nor antithymocyte globulin altered excretion of herpes simplex virus. Reversible leukopenia and thrombocytopenia occurred in seven interferon recipients. Patient and graft survival were comparable in interferon and placebo groups. There preliminary results suggest that a six-week course of prophylactic interferon delays shedding of cytomegalovirus and decreases the incidence of viremia after transplantation. In contrast, antithymocyte globulin appears to increase the severity of infection from cytomegalovirus among these patients.

Adult↗
PubMed1979

Detection of persistent left superior vena cava by two-dimensional contrast echocardiography.

One hundred seventy adult patients with possible congenital or valvular heart disease underwent contrast two-dimensional echocardiographic examination as part of a precatheterization evaluation. Persistent left superior vena cava was detected in 5 patients, each of whom demonstrated an abnormally large coronary sinus. Injection of echocardiographic contrast material from a peripheral left arm vein resulted in early opacification of this structure before other right-side chambers, thus suggesting abnormal venous drainage. Persistent left superior vena cava was confirmed in all 5 patients at the time of catheterization and/or surgery.

Adolescent↗
PubMed1979

Left atrial myxoma: false negative echocardiographic findings in a tumor demonstrated by coronary arteriography.

A report of left atrial myxoma discovered at coronary arteriography by virtue of unusual tumor "vascularity" is presented in which establishing the diagnosis by means of echocardiography proved difficult. The difficulty may have been due to the highly vascular nature of the tumor with resultant loss of the acoustic reflectivity required for echocardiographic demonstration. Previous cases in which left atrial myxomas have shown arteriographically demonstrable "tumor vascularity" are reviewed.

Aged↗
PubMed1979

Cryohypophysectomy for bone pain of metastatic breast cancer.

In a series of 22 patients, cryohypophysectomy gave relief of bone pain from metastatic breast cancer for 3 months in 55% of patients and for 6 months in 32% of patients. On average they were pain free for 55% of their remaining life. Advantages of this technique are the avoidance of a major operation, the mild disturbance to the patient, a short hospital stay and the paucity of significant complications apart from a need for hormone replacement.

Bone Neoplasms↗
PubMed1979

Immune-complex glomerulonephritis associated with cytomegalovirus infection.

Histologic and immunopathologic studies were performed at autopsy on the kidneys of a patient in whom hematuria and proteinuria developed in association with cytomegalovirus (CMV) pneumonitis. Light microscopic examination of the kidneys revealed focal mesangial proliferative glomerulonephritis. Immunofluorescent microscopy revealed a granular deposition of IgG, IgA, C3, and C4, mainly in the mesangium. CMV antigens were also demonstrated in a similar immunofluorescent pattern. Glomerulus-bound immunoglobulins were eluted and demonstrated to contain antibodies to CMV antigens. These findings suggest that in some patients who have CMV infection immune-complex glomerulonephritis is induced by glomerular deposition of CMV antigen-antibody complexes.

Antigens, Bacterial↗
PubMed1979

Malapposition of the mitral valve: a two-dimensional echocardiographic sign of left ventricular dysfunction.

A pattern of mitral valve closure (malapposition) was observed in 75 of 1,267 patients examined with two-dimensional echocardiography. Criteria defining malapposition are: (a) the mitral valve leaflets exhibit a reduced area of coaptation during systole, (b) the angle at the point of coaptation of the anterior and posterior mitral valve leaflets becomes progressively more obtuse, approaching 180 degrees, and (c) the atrioventricular groove, the coaptation point, and the basal portion of the aortic root lie along the same vertical line. Malapposition appears to be the common denominator of previously described M-mode abnormalities seen in altered left ventricular hemodynamics and dysfunction.

Diagnosis, Differential↗
PubMed1978

Primary cytomegalovirus and opportunistic infections. Incidence in renal transplant recipients.

Thirty-five renal allograft recipients were studied concerning the relationship between cytomegalovirus (CMV), herpes simplex virus (HSV), and opportunistic bacterial and fungal infections. The incidence of opportunistic infections was determined for patients whose tests prior to transplantation were seronegative in complement fixation and indirect hemagglutination assays of CMV antibody and for those patients whose tests were seropositive. Among the six seronegative patients with seronegative tests, four (66%) experienced active CMV infection within two months, and four died of Candida or Aspergillus infection within six months after transplantation. Among the 22 patients with seropositive tests, only one (4%) had a fungal infection and it was nonfatal (P less than .05). The increased morbidity and mortality due to fungal and bacterial infections in transplant recipients with seronegative CMV tests appears, therefore, to be related to primary CMV infection rather than to generalized immunodeficiency.

Antibodies, Viral↗
PubMed1978

Identification of the functional ionic groups of papain by pH/rate profile analysis.

The pH dependence of papain catalysis was analyzed by a scheme which evaluates the kinetic contribution of both protonated and unprotonated species of functional groups involved in catalysis. Kinetic measurements were made at constant pH, without buffers, by automatic titration. The rate-determining step for papain-catalyzed hydrolysis of alpha-N-benzoyl-L-arginine ethyl ester, determined by nucleophile competition, changed from acylation below pH 6.5 to mixed acylation-deacylation above pH 6.5. Kinetic analysis indicated that three prototropic groups governed the pH-specificity of alpha-N-benzoyl-L-arginine ethyl ester hydrolysis. These prototropic groups had pKa values of 4.8, 6.5 to 6.7, and 8.7. Theoretical treatment of the kinetics provided an excellent fit with the experimentally found profile when the contribution of all three prototropic groups was considered. Analysis showed that, in acid, the pathways of papain catalysis were functional with either two or three active-site protons. In base, a single functional ionic pathway is associated with an active site with only one proton. Pathways involving an unprotonated active site are catalytically inoperative in both acid and base. These results indicate that papain exhibits several catalytically functional ionic pathways. The results are discussed in terms of pKa assignments, and the mechanism of papain catalysis.

Arginine↗
PubMed1978

The microbiological flora of penile ulcerations.

The penile ulcerations of 100 consecutive men were tested for microorganisms. A polymicrobial flora was identified in the ulcers of 97 men. The microorganisms recovered from these ulcers included combinations of anaerobic and aerobic bacteria (including Mycoplasma), herpes simplex virus, yeasts, and filamentous fungi. Fifty-three study entrants had microorganisms, identified by culture or serologic tests, that were considered primary in ulcer pathogenesis. Herpes simplex virus was the most prevalent and Treponema pallidum was the next most prevalent pathogen identified. Of our patients, 5% had two recognized pathogens confirmed by laboratory tests, and only one of these was suspected at clinical examination. In addition, the study suggests that microorganisms other than Haemophilus ducreyi can produce ulcers with a morphology mimicking chancroid.

Adolescent↗
PubMed1978

The effects of prenatal protein restriction on the developing mouse cerebrum.

Purified low protein maternal diets cause a reduction in total weight and protein content but not in DNA content (cell number) of the cerebrum of newborn mice. Female mice were fed diets in which 8%, 11%, 15%, or 27% (control) was casein as the sole source of protein for 1 or 2 months prior to mating and throughout gestation. A 15% casein diet fed for 1 month had no effect on brain weight, DNA content (cell number) or protein content in the cerebrums of newborn mice. Female mice fed an 8% or 11% protein diet for 1 or 2 months prior to conception and throughout gestation gave birth to young that had a decreased cerebral weight and protein content. However in neither case was the amount of cerebral DNA (cell number) of the newborn from females in the low protein group significantly different from that in the cerebrums of mice born to females on the normal protein diet.

Animals↗
PubMed1978

Influence of genital herpes on results of fluorescent treponemal antibody absorption test.

Both the fluorescent treponemal antibody absorption (FTS-ABS) test and Venereal Disease Laboratory (VDRL) test for syphilis were performed routinely on 113 men with histories of genital ulcerations. The difference in negative VDRL and borderline FTS-ABS results between patients with and without herpes simplex virus in their genital ulcers and no evidence of previous or untreated syphilis was not statistically significant. Furthermore, use of the FTA-ABS test as a confirmatory rather than a screening test eliminates false-positive, borderline, or reactive results in patients with non-syphilitic ulcers.

False Positive Reactions↗
PubMed1978

Cytomegalovirus infection in dialysis patients and personnel.

In a 12-month prospective study of cytomegalovirus infection on an acute hemodialysis unit, 10 of 80 patients (13%) and none of 26 staff developed active cytomegalovirus infection. Seven infections were coincidental with renal allograft rejection; three occurred 3 to 6 weeks after the transfusion of multiple units of conventional blood into seronegative patients. No person-to-person transmission was documented. In contrast to the effects of transfusing conventional blood, all 21 patients who entered dialysis without detectable cytomegalovirus antibody and received 2 to 10 U of frozen deglycerolyzed erythrocytes (total of 157 U) remained seronegative. Transmission of cytomegalovirus infection with transfusion with conventional blood is probably secondary to passage of leukocyte-borne virus that is lost during the freezing and deglycerolization procedure. Frozen erythrocytes prepared by cytoagglomeration procedures appear to be free of viable leukocytes and appear to carry a minimal risk of transmitting cytomegalovirus infection.

Acute Disease↗
PubMed1977

Small-scale trial of live-attenuated influenza vaccine (A/Hong Kong/68).

Seventy-one men who were given live-attenuated A/Hong Kong/68 (H3N2) influenza vaccine during November 1973, and 34 men given placebo were examined for changes in antibody level. Overall, 12 of the 71 men (17%) given the vaccine showed a fourfold rise in haemagglutination-inhibition (HI) antibody titre after 14 days. No such rises were seen in the 34 men given placebo. However, 10 of the men showing a fourfold rise were from 19 who had no detectable HI antibody to this virus before vaccination, representing a conversion rate of 53%. The other two had a HI titre of 1/10 before vaccination. The absence of antibody response, at 14 days, in those with an HI titre of 1/20 or greater may indicated that this represents a protective level against infection. However, the vaccine virus was probably overattenuated and may have constituted a weaker challenge than might occur with a wild strain. No influenza virus was isolated from either group in the week after vaccination and no evidence of transmission to the placebo group was seen. Mild symptoms, chills, muscle pain, and stiffness were more frequently seen in the 12 persons showing a fourfold rise in antibody than in the rest of the volunteers.

Administration, Intranasal↗