Rapid ventricular pacing in pigs: an experimental model of congestive heart failure.

To develop an improved animal model of congestive heart failure, 11 female farm pigs (wt, 42-46 kg) underwent rapid ventricular pacing at 230 beats/min for 7 days with a modified Medtronic unipolar pacemaker connected to an apical pacing lead. After 7 days the pacemaker was turned off, anesthesia induced, the chest opened, and cardiac hemodynamic and dimensional studies were performed. Results were subsequently compared with data from 12 control pigs that received no pacing.

Long-term changes in corneal endothelium after keratoplasty. A follow-up study.

In 1983, Abbott et al. assessed endothelial cell population and function in 100 clear corneal grafts (72 patients) that were an average of 17.4 years postkeratoplasty.

Molecular, biochemical, and cellular biology of human breast cancer.

The meeting at Tamarron illustrated the multiplicity of molecular changes found in breast cancer and concluded with the disquieting sense that, so far, there is no simple unifying molecular model to explain the etiology of the disease. Perhaps the complex nature of breast cancer precludes formulation of a simple model. The biologic heterogeneity of breast cancers may reflect the fact that, at the molecular level, there is more than one way to accomplish each of the phenotypic changes necessary for malignant growth.

Family of human neuronal external surface epitopes defined by Torpedo monoclonal antibodies.

We are employing a library of monoclonal antibodies (MAbs) that were made to Torpedo cholinergic synaptosomes to identify conserved, physiologically vital epitopes of the neuronal surface. Our particular interest is in those epitopes that are present on some but not all neurons. In the present study we screened this library on different cell lines, the neuronal cell lines PC12, NG108, MC-IXC, and SY5Y, and the endocrine cell lines GH-3 and HIT.

Future directions. Collagen-based prostheses for meniscal regeneration.

Prosthetic meniscal replacement offers the ability to stabilize the meniscectomized knee and provide prophylaxis against early degenerative arthritis. Since prosthetic meniscal replacement may be performed in the setting of normal articular cartilage, a prosthesis will be required to match the exact joint configuration, induce the same lubricity, produce the same coefficient of friction, and absorb and dampen the same joint forces (without incurring significant creep or abrasion) as does the normal meniscus. This feat is currently beyond the capabilities of artificial materials alone.

Dissociated vertical deviation in a patient with Duane's retraction syndrome.

Dissociated vertical deviation is a not uncommon strabismic syndrome characterized by upward deviation of an eye when occluded, with downward movement of the eye when occlusion is removed. Associated findings include latent nystagmus and horizontal strabismus. Duane's retraction syndrome is the clinical declaration of anomalous cranial nerve innervation characterized by a marked limitation or absence of abduction, variable limitation of adduction, narrowing of the palpebral fissure, and apparent globe retraction on attempted adduction.

Anterior ischaemic optic neuropathy and intraocular pressure.

Anterior ischaemic optic neuropathy is a stroke syndrome of the distal optic nerve, characterised by disc oedema and optic nerve dysfunction--loss of central vision, loss of colour vision, a relative afferent pupillary defect, and nerve fibre layer field loss. We prospectively evaluated the changes of intraocular pressure throughout the day in 16 patients with non-arteritic anterior ischaemic optic neuropathy and 15 normal control subjects of similar age and race. The peak intraocular pressure exceeded 21 mm Hg in five of the ischaemic optic neuropathy patients but none of the controls.

Optimal cardioplegia and 24-hour heart storage with simplified UW solution containing polyethylene glycol.

Recent work has shown that UW may be better than standard cardioplegic solutions for short-term heart preservation. In this study we have used a rabbit heart model to evaluate a simplified UW solution in which penicillin, dexamethasone, insulin, allopurinol, and adenosine were omitted and 5% polyethylene glycol (PEG20M) was substituted for hydroxyethyl starch. The test systems consisted of 4-hr cardioplegic storage at 15 degrees C with repeated flushing every 30 min for 2 hr and 24-hr hypoxic low-flow microperfusion (3 ml/g/24 hr) at 0 degrees C.

Seroconversion, staging and survival. Natural history of HIV infection.

With the discovery of human immunodeficiency virus (HIV), researchers identified the etiologic agent for acquired immunodeficiency syndrome (AIDS). Although neither a cure nor a vaccine exists for this fatal disease, considerable information is now available on the progression from HIV infection through AIDS. Understanding the natural history of this progression can facilitate early detection and intervention.

Crystalloid versus colloid fluid therapy after cardiac surgery.

Differences in hemodynamic stability and fluid requirements were examined in patients randomly assigned to receive either normal saline crystalloid solution (N = 10) or hetastarch colloid solution (N = 11) after coronary artery bypass or valve operation. Both solutions were administered in the same manner for 8 hours after surgery, with hourly assessment of hemodynamic parameters and intake/output data. Infusion rates and 8-hour intake were higher for the group receiving normal saline solution (p less than 0.

Effects of left ventricular pressure reductions on right ventricular systolic performance.

Reductions in left ventricular pressure (LVP) have been shown to produce a leftward shift of the interventricular septum and to reduce left ventricular contribution to right ventricular performance. To evaluate the magnitude of this contribution in the intact heart, five anesthetized pigs were implanted with a left prosthetic ventricle to gradually decrease LVP while maintaining arterial systemic pressure. Three descriptors of RV global and regional systolic function were studied in the septum to free wall (RVSFW) and anterior to posterior (RVAP) dimensions and in an outflow tract segment length (RVSL), during both steady state and transient inferior vena cava occlusion.

Atypical corneal manifestations of multiple myeloma. A clinical, histopathologic, and immunohistochemical report.

A 52-year-old male developed bilateral subepithelial amorphous corneal deposits as well as diffuse noniridescent anterior stromal haze of unknown etiology. The deposits increased in density and a penetrating keratoplasty was performed in one eye when vision became sufficiently compromised. Pathological evaluation of the tissue included light and electron microscopy and immunohistochemical studies.

Use of pericardium to control bleeding after ascending aortic graft replacement.

We present the case of a patient who required replacement of an ascending aortic composite graft for endocarditis complicated by uncontrollable bleeding from the proximal anastomotic site. A new method of creating a right atrial-to-periprosthetic space fistula with autologous pericardium was used with a favorable result.

Naturally occurring antibodies against Mycobacterium avium complex.

Serum obtained from 57 healthy individuals and patients admitted to the hospital owing to diverse pathological causes, as well as serum from seven patients with AIDS and disseminated Mycobacterium avium complex (MAC) infection, were studied to determine the prevalence of IgG and IgM antibodies against surface proteins of M. avium complex. Immunodot assay to detect serum positivity against MAC and Western Blot technique in order to determine the MAC antigens eliciting antibody production were performed.

Successful biventricular circulatory support as a bridge to cardiac transplantation during prolonged ventricular fibrillation and asystole.

The indications for biventricular versus left ventricular mechanical circulatory support as a bridge to cardiac transplantation are not well established. In this study, 27 potential heart transplant candidates who were in imminent risk of dying before donor heart procurement were implanted with Thoratec prosthetic ventricles (21 biventricular and six left ventricular) at three medical centers. A total of 21 patients (16 biventricular and five left ventricular) underwent successful cardiac transplantation after 1-65 days of circulatory support, and 19 were discharged from the hospital.

Monoclonal antibody Tor 23 binds a subset of neural cells in the human cortex and displays an altered binding distribution in Alzheimer's disease.

Recent evidence suggests that alterations in molecules of the external neuronal surface may be pivotal factors in Alzheimer's disease (AD) either as primary or secondary lesions. We are studying neuronal surface components with a library of monoclonal antibodies (MAbs) made to highly purified, exclusively cholinergic nerve terminals of the Torpedo ray. The most extensively characterized of the Tor MAbs.

Treatment of experimental disseminated Mycobacterium avium complex infection in mice with recombinant IL-2 and tumor necrosis factor.

Mycobacterium avium complex (MAC) is the most common bloodstream pathogen isolated from patients with AIDS. We have previously shown that TNF alone or in combination with IL-2 can activate human and murine macrophages in vitro to kill MAC strains isolated from disseminated infections. To determine whether treatment with TNF and IL-2 could effect the course of disseminated MAC infections in a murine model of disseminated MAC infection, we infected C57BL mice with 3 x 10(8) bacteria i.

Portasystemic shunt fraction quantification using transrectal administration of iodine-123 iodoamphetamine in dogs with chronic bile duct ligation and after propranolol administration.

Following transrectal administration, 123I iodoamphetamine (IMP) has been shown in both animal and patient studies to be capable of detecting the presence of portasystemic shunting (PSS). However, the ability of this method to actually quantitate PSS in the presence of cirrhosis and propranolol has not been demonstrated. We studied nine dogs with hitologically proven cirrhosis induced by chronic bile duct ligation.

Oxidative and non-oxidative intracellular killing of Mycobacterium avium complex.

Among mycobacteria, those belonging to the Mycobacterium avium complex (MAC) are the most common cause of bacteremia in AIDS patients. To understand better the mechanisms by which human macrophages kill intracellular MAC, we studied in an in vitro test system transparent morphotypes of the three most common bacteremic serotypes from AIDS patients and an opaque variant, obtained in vitro from the most mouse-virulent strain (MAC 101). The three serotypes differed in susceptibility to oxidative bactericidal mechanisms of macrophages.

Bacteriostatic and bactericidal in-vitro activity of meropenem against clinical isolates, including Mycobacterium avium complex.

For clinical isolates the MICs of meropenem were significantly lower than the MICs of imipenem, especially against Pseudomonas aeruginosa. Furthermore, meropenem was bactericidal for Pseudomonas spp., including Ps.

Measuring creatine kinase MB isoenzyme in a maintenance hemodialysis population: chemiluminometric immunoassay and electrophoresis compared.

In an effort to clarify the issue of potentially false increases in creatine kinase (EC 2.7.3.