Dynamic in vitro and in vivo performance of a permanent total artificial heart.

In vivo characterization studies were performed to compare the dynamic in vivo performance of the Penn State/3M Health Care electric total artificial heart to existing in vitro data. Fully implanted systems were utilized including the artificial heart, controller, backup batteries, compliance chamber, and transcutaneous energy transmission. Catheters were implanted to measure central venous pressure (CVP), left atrial pressure (LAP), right atrial pressure (RAP), pulmonary artery pressure (PAP), and aortic pressure (AoP). Cardiac output (CO) was determined from the implanted controller, and systemic vascular resistance (SVR) was calculated. Steady state data were collected for each animal along with data regarding the transient responses to changes in preload and afterload. Preload was manipulated through volume changes. Afterload changes were accomplished through vasoactive agents. Increased preload caused little change in cardiac output because the pump output was nearly maximum at baseline. LAP, AoP, and SVR increased with increasing RAP. Decreased preload caused a reduction in CO, LAP, and SVR. Afterload increase resulted in a slight decrease in flow and an increase in system power and SVR. Afterload reduction was accompanied by a decrease in preload and a concomitant reduction in flow. Overall, the system response was similar to the response observed in vitro.

Clinical presentation and outcome of patients with HIV infection and tuberculosis caused by multiple-drug-resistant bacilli.

OBJECTIVE: To determine the clinical manifestations of patients with human immunodeficiency virus (HIV) infection and tuberculosis caused by multiple-drug-resistant bacilli compared with those with single-drug-resistant or susceptible bacilli. DESIGN: Descriptive, case-control, and cohort studies. SETTING: A large urban teaching hospital. PATIENTS: Sixty-two patients with tuberculosis caused by multiple-drug-resistant bacilli (cases) and 55 patients with tuberculosis caused by single-drug-resistant or susceptible bacilli (controls). MEASUREMENTS: Characteristics of clinical presentation, radiographs, pathologic abnormalities, antituberculosis treatment, and clinical course. RESULTS: Twenty cases (32%) had concomitant pulmonary and extrapulmonary disease at presentation compared with 9 controls (16%; odds ratio, 2.4; 95% CI, 1.0 to 5.9). More cases had alveolar infiltrates (76%; odds ratio, 3.6; CI, 1.2 to 11.4), interstitial infiltrates with a reticular pattern (67%; odds ratio, 7.8; CI, 1.0 to 83.5), and cavitations (18%; odds ratio, 6.6; CI, 0.8 to 315.3) on initial chest radiographs compared with controls (49%, 19%, and 3%, respectively). Pathologic specimens from cases showed extensive necrosis, poor granuloma formation, marked inflammatory changes with a predominance of neutrophils, and abundant acid-fast bacilli. Twenty-five cases received two or more effective antituberculosis drugs for more than 2 months. Only 2 cases had three consecutive negative cultures for Mycobacterium tuberculosis; one patient died within 1 day of the last negative culture, and the other had positive cultures 496 days later. The remaining 23 cases had persistently or intermittently positive cultures despite therapy. The clinical course of these cases suggested overwhelming miliary tuberculosis with involvement of the lungs (77%), pleura (15%), stool (34%), meninges (13%), bone marrow (16%), blood (10%), lymph nodes (10%), and skin (8%). The median survival time was 2.1 months for cases compared with 14.6 months for controls (P = 0.001, log-rank test). CONCLUSIONS: Tuberculosis caused by multiple-drug-resistant bacilli in patients with HIV infection is associated with widely disseminated disease, poor treatment response with an inability to eradicate the organism, and substantial mortality.

Detection of herpesvirus DNA in vitreous and aqueous specimens by the polymerase chain reaction.

Members of the herpesvirus family, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and herpes simplex virus (HSV), have been recognized as causal agents of chorioretinal inflammatory diseases. We investigated the use of the polymerase chain reaction for the detection of CMV, HSV, and EBV genomes in aqueous, subretinal fluid, and vitreous specimens in patients with clinically diagnosed CMV retinitis. Cytomegalovirus but not HSV or EBV genomic sequences were detected in all of these clinical specimens. We also investigated 18 normal aqueous and eight normal vitreous specimens obtained from patients undergoing cataract or vitrectomy surgery. Cytomegalovirus, HSV, and EBV DNA were not detected in any of the normal aqueous specimens. There was one weakly positive CMV normal vitreous, but none was HSV or EBV positive by the polymerase chain reaction. These results indicate that the polymerase chain reaction may be useful as a rapid and sensitive diagnostic technique to aid in the confirmation of clinical observations.

Acquired immunodeficiency syndrome associated with Acanthamoeba infection and other opportunistic organisms.

A 29-year-old Haitian man with acquired immunodeficiency syndrome presented with nasal obstruction and epistaxis. A computed tomogram of the head showed thickened nasal and paranasal sinus mucosa. A biopsy specimen of the turbinate disclosed inflammatory tissue containing amoebic trophozoites. The patient was empirically treated with rifampin and ketoconazole. He died four months after biopsy of other complications of acquired immunodeficiency syndrome. At autopsy, the amoebic infection was found only in the paranasal sinuses, a calf nodule, and in an intradermal abscess in the left leg. Pneumocystitis carinii pneumonia, Mycobacterium avium-cellulare in the liver and retroperitoneal lymph nodes, cytomegalovirus infection of the adrenal glands, and Kaposi's sarcoma in the spleen were additionally present. The organism was cultured and studied by electron microscopy, dark-field microscopy, and immunofluorescence.

Immunohistologic identification of fungi in systemic and cutaneous mycoses.

Using specific antibodies and the peroxidase-antiperoxidase technique, we were able to demonstrate a variety of fungal organisms in smears and sections of formaldehyde-fixed, paraffin-embedded tissue. The procedure is simple, fast, and accurate and may be used as an alternative to, or in conjunction with, cultural methods to identify fungi specifically.

Disseminated Mycobacterium avium-intracellulare infection appearing as a panniculitis.

A 34-year-old woman had wide-spread panniculitis due to a disseminated infection with Mycobacteria avium-intracellulare. The patient had previously received treatment with high dosages of corticosteroids. Suppurative lesions teeming with acid-fast bacilli and without formation of granulomas were found in many organs, including the skin, mediastinum, spleen, liver, and gastrointestinal tract. Both the appearance of disseminated M avium-intracellular infection resembling panniculitis and the involvement of mediastinum have not previously been reported, to our knowledge.

Immunoglobulin G- and M-specific enzyme-linked immunosorbent assay for detection of dengue antibodies.

An enzyme-linked immunosorbent assay for the detection of antibodies to dengue virus is described. This method correlates well with a hemagglutination inhibition technique. The enzyme-linked immunosorbent assay can also be specific for human immunoglobulin M antibodies when a mu-chain-specific antiglobulin-enzyme conjugate and fractionated serum are employed. By using this technique, dengue immunoglobulin M antibodies were demonstrated in an infant suspected of having a recent dengue infection.

The effects of transient candidemia on the brain: preliminary observations on a rodent model for experimental deep candidosis.

Deep candidosis was established in healthy uncompromised Wistar rats by injecting Candida albicans into the right internal carotid artery. Death of these animals could be produced within seven days by injecting 10(7) yeasts. The kidneys were most severely infected, and the entire brain was involved. No animal demonstrated leptomeningitis. Within one to two days microabscesses developed, subsiding into a histiocytic response in five to seven days. By seven days, chronic inflammation with noncaseating granulomas was seen. Throughout the study, cerebrospinal fluid and blood cultures failed to demonstrate the fungus. This rodent model is similar to human cerebral candidosis.