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Biomedical subjects

D J Sexton

Publications and source records attributed to D J Sexton.

At least 109 records · Page 6Linked to original sources
PubMed1989

HIV-associated myocarditis treated with zidovudine (AZT).

Congestive cardiomyopathy has been reported in patients infected with human immunodeficiency virus (HIV). In this report of diffuse lymphocytic myocarditis in a patient who tested positive for HIV antibody after receiving blood from an HIV-positive donor, the patient failed to respond to conventional medical therapy. Although no opportunistic infection or malignancy was observed by electron-and light-microscopic examination of the endomyocardial tissue sample at biopsy, it was decided to give the patient zidovudine (AZT) at a dosage of 200 mg every 4 hours. Definite clinical improvement was noted on repeat right heart catheterization and endomyocardial biopsy 3 months after the initiation of AZT therapy. This case supports the theory that myocarditis can be caused by HIV and suggests that AZT may be useful in the treatment of patients with HIV-associated cardiomyopathy.

Journal Article↗
PubMed1987

Interactions between precipitating and nonprecipitating antibodies in the formation of immune complexes.

In the present study, we used monoclonal antidinitrophenol (DNP) antibodies to determine certain of the biophysical characteristics of precipitating and nonprecipitating antibodies. In addition, we studied the dynamics of immune complex (IC) formation when precipitating antibodies react with antigen in the presence of nonprecipitating antibodies. The antigen utilized in these studies was DNP-bovine serum albumin. All isolated nonprecipitating anti-DNP antibodies were of the IgG2b isotype, whereas all antibodies with other isotypes (IgG1, IgG3, IgM, IgA and IgE) were precipitating. Nonprecipitating antibodies did not differ significantly from precipitating antibodies in affinity, valence, or isoelectric point. Nonprecipitating antibodies inhibited the formation of precipitable IC between antigen and precipitating antibodies. In addition, preformed IC precipitates were solubilized by nonprecipitating antibodies. The solubilization of IC precipitates was influenced by the isotype of the precipitating antibody and by the antibody:antigen ratio in the IC precipitate. By isokinetic sucrose density centrifugation, we determined that solubilization of IC precipitates by nonprecipitating antibodies was associated with release of free precipitating antibody and formation of soluble IC between the antigen and the nonprecipitating antibody. In conclusion, in this study the nonprecipitating property of mouse anti-DNP antibodies is isotype-specific. Nonprecipitating antibodies compete and displace precipitating antibodies from the antigen, resulting in inhibition of IC precipitation and in IC solubilization. On the basis of the present results, we postulate that antibody-antibody interactions are important determinants of precipitating ability, and that these interactions are a characteristic of antibody isotype.

Animals↗
PubMed1985

Mucormycosis after open fracture injury.

An 18-year-old woman (a former intravenous drug abuser) sustained open tibial plateau and shaft fractures, followed by cellulitis and a wound infection caused by a Rhizopus species, which is a fungus of the class Mucorales. The patient responded to surgical debridement and a prolonged course of amphotericin B. No lymphocyte abnormality or other host immune defect could be demonstrated in this patient.

Accidents, Traffic↗
PubMed1985

Pregnancy-associated group B streptococcal endocarditis: a report of two fatal cases.

Group B streptococci commonly colonize parturient women, yet pregnancy-associated endocarditis due to this organism is rare. Most reports of group B streptococcal endocarditis are from the preantibiotic era and occurred in women with rheumatic mitral valve disease. Reported herein are two cases of fatal group B streptococcal endocarditis involving the aortic valve of women with no preexisting heart disease. One had undergone a second-trimester abortion and the other had a normal pregnancy and uncomplicated vaginal delivery.

Abortion, Induced↗
PubMed1982

Endophthalmitis: current approaches.

Seventy patients referred with a diagnosis of endophthalmitis underwent anterior chamber and vitreous taps with intracameral antibiotic injections. Fifty-four eyes were culture positive, 34 (63%) after previous intraocular surgery, 12 (22%) had sustained penetrating trauma, and 8 (15%) resulted from a metastatic infection. Of 61 total isolates, 48 (79%) were gram positive, 9 (15%) were gram negative, and 5 (8%) were fungi. Visual recovery after surgery was related to the relative virulence of the organisms isolated. Twenty-four (44%) eyes achieved 20/400 or better vision, but only seven (13%) obtained 20/40 or better vision. Patients with a markedly abnormal ERG operatively demonstrated poor visual acuity recovery, while patients with near normal ERG recovered better vision. The authors currently recommend vitrectomy in patients with endophthalmitis whenever the retina cannot be visualized.

Adult↗
PubMed1979

Cytomegalovirus infection and chronic hemodialysis.

Serologic and virologic studies of cytomegalovirus (CMV), a virus infection often disseminated in immunosuppressed patients, were initiated among hemodialysis patients, home dialysis partners, hemodialysis center personnel, and several groups of patients. No evidence was found of activation or persistence of CMV infections in connection with chronic renal disease or in association with hemodialysis. Evidence of increased CMV activation and/or infection was found among individuals who had re-entered the dialysis program following renal allograft rejection. The data indicate that dialysis personnel and home dialysis partners are not at increased risk for CMV infection. The findings of this study, which contrast with those pertaining to hepatitis B infection, suggest that different mechanisms are responsible for establishing both infection and persistence of CMV and hepatitis B.

Adult↗
PubMed1978

Amebiasis: epidemiologic studies in the United States, 1971-1974.

Seven investigations of suspected foci of amebiasis between October 1971 and June 1974 lead to three conclusions. (1) A number of laboratories have vastly overdiagnosed amebiasis and have reported leukocytes in stools as Entamoeba histolytica. Two laboratories found to be in error were in community hospitals, and one was at a teaching hospital associated with a medical school and a school of public health. These three laboratories had been diagnosing more than 1200 cases of amebiasis a year for 20 years. (2) When amebiasis does occur, it is likely to be misdiagnosed. In one outbreak with four cases and three deaths, amebiasis was not diagnosed until two patients had died and another was critically ill. Sporadic cases may be mistakenly diagnosed as ulcerative colitis and inappropriately treated with steroids. (3) Foci of endemic amebiasis continue to exist in the United States, both in institutions and in noninstitutional settings.

Amebiasis↗
PubMed1977

Inappropriate antidiuretic hormone secretion. Occurrence in a patient with Rocky Mountain spotted fever.

A 51-year-old man with serologically confirmed Rocky Mountain spotted fever was believed to have inappropriate antidiuretic hormone (ADH) secretion. He was observed for four days in the hospital until the correct diagnosis was made. During this period, he progressively became more hyponatremic, despite a low BUN level and the administration of large amounts of sodium and water. At the time, his serum sodium concentration was 117 mEq/liter, and his urine was hypertonic to that of serum. Thereafter, his serum sodium level rose with fluid restriction. Rickettsia-induced CNS damage may have lead to the inappropriate ADH release that was observed in this patient.

Humans↗
PubMed1977

Endemic amebiasis in an extended family.

Two cousins from a large Spanish-American family were simultaneously diagnosed as having amebic liver abscesses. Survey of 183 extended-family members revealed that 45.7% of 162 had a positive amebiasis indirect hemagglutination test and 12.6% of 111 had cysts or trophozoites of Entamoeba histolytica demonstrated in a single stool examination. A total of five family members had had liver abscesses; two deaths had occurred. In a random sample survey of the remainder of the community, only one person (0.3%) had a positive serologic test. Within the extended family, person-to-person appeared to be the predominant mode of transmission. Water supplies were not contaminated. Both community and extended family homes had the same source of water. Type and source of food supply were not correlated with infection and there was no evidence to implicate an infected food handler. Clustering of seropositivity occurred in homes without indoor toilets. Homes of the extended family were more crowded and significantly fewer of them had indoor toilets. Endemic foci of amebiasis continue to exist in the United States. Follow-up family and other close contacts of persons with amebiasis will frequently identify other cases.

Feces↗