Adoption of HIV-related services among urban US hospitals: 1988 and 1991.

Recent reports document that US hospitals vary considerably, notably by ownership, in the number of acquired immunodeficiency syndrome (AIDS) patients they treat. Still, little is known about other types of hospital response to human immunodeficiency virus (HIV) and AIDS and the relative strength of ownership as a determining factor. With annual survey data from the American Hospital Association the authors examine the formal adoption of HIV-related services among urban US hospitals at the turn of the decade.

Terminal differentiation-dependent alteration in the expression of translation elongation factor-1 alpha and its sister gene, S1, in neurons.

Elongation factor-1 alpha (EF-1 alpha) is a highly conserved, abundantly expressed protein that functions in peptide elongation during mRNA translation. Mammalian species contain a second EF-1 alpha gene, S1, whose expression is limited to brain, heart, and skeletal muscle. Such tissue specificity in S1 gene expression led us to hypothesize that this specialized member of the EF-1 alpha family is possibly essential to terminally differentiated, long-lived cells such as neurons, cardiomyocytes, and myocytes.

Continuous ST segment recording during thrombolysis in acute myocardial infarction: a report on orthogonal ECG monitoring.

Background: A noninvasive, real time method is needed to identify failures of thrombolysis and evaluate new treatments in acute myocardial infarction (MI).

Objective: To study XYZ monitored ST segment evolution during thrombolysis in acute MI and to examine the correlation of ST parameters to outcome.

Design: Thirty-five patients receiving tissue plasminogen activator (tPA) (n = 18) or streptokinase (SK) (n = 17) for acute MI were monitored by vector-cardiography during the first 12 h of thrombolytic therapy.

Calcium absorption, endogenous excretion, and endocrine changes during and after long-term bed rest.

Negative calcium balance is a known consequence of bed rest, and is manifested in elevated urine and fecal calcium (Ca). Elevated fecal Ca can result from either decreased absorption, increased endogenous fecal excretion, or both. We measured the Ca absorption and endogenous fecal excretion in eight healthy male volunteers before and during 4 months of bed rest.

Hologic QDR 2000 whole-body scans: a comparison of three combinations of scan modes and analysis software.

This study reports on the short-term in vivo precision and absolute measurements of three combinations of whole-body scan modes and analysis software using a Hologic QDR 2000 dual-energy X-ray densitometer. A group of 21 normal, healthy volunteers (11 male and 10 female) were scanned six times, receiving one pencil-beam and one array whole-body scan on three occasions approximately 1 week apart. The following combinations of scan modes and analysis software were used: pencil-beam scans analyzed with Hologic's standard whole-body software (PB scans); the same pencil-beam analyzed with Hologic's newer "enhanced" software (EPB scans); and array scans analyzed with the enhanced software (EA scans).

Support service use by persons with AIDS and their caregivers.

The purpose of this study was to identify factors related to the use and non-use of emotional and practical support services by persons with AIDS (PWAs) and their informal caregivers. Unmet need for PWA support services and perceived barriers to the use of these types of services were also identified. Structured interviews were conducted with 472 self-selected informal AIDS caregivers in greater Los Angeles and the San Francisco Bay area.

Rapid, sensitive, and noninvasive sampling technique for determination of chloroform in alveolar breath.

A sampling technique for the determination of chloroform in alveolar breath is presented. Subjects exhale in a homemade device for collection of the alveolar fraction. The collected sample is transferred to a partially evacuated headspace vial and subsequently analyzed by capillary gas chromatography using electron-capture detection.

Effects of retained diaphyseal plates on forearm bone density and grip strength.

Numerous complications have been attributed to elective plate removal following successful treatment of both bone diaphyseal forearm fractures, yet the effects of retained implants are not known. Fourteen patients were reviewed for residual forearm grip strength (FGS) and bone mineral density (BMD) following uneventful union. Patients were analyzed in two groups based upon time from fixation: group I, > 2 years but < or = 5 years, and group II, > 5 years.

Improved beat-to-beat timing measurements of His-bundle signal.

A simplified bioelectric model of the atrioventricular (AV) junction is proposed to better understand the underlying biophysical generation of intracardiac His-bundle signal and to analyze the effects of electrocatheter displacements on waveform morphology and estimation of AV node conduction time (AVCT). Based on this model, an inverse problem approach has been developed to estimate electrode displacements occurring in real recordings. A measurement correction method is proposed to improve estimation of AVCT.

Evaluation of dermal and respiratory chloroform exposure in humans.

Chloroform is a known contaminant of chlorinated drinking water and of swimming pool water disinfected with chlorine or one of its derivatives. Few data exist regarding the importance of dermal and inhalation exposure routes to the chloroform body burden resulting from domestic and recreational use of chlorinated water. In our experimental study involving 11 male swimmers, we quantified the body burden resulting from exposure to various concentrations of chloroform in water and air of an indoor swimming pool, during a daily 55-min exercise period.

Production of Alzheimer 4kDa beta-amyloid peptide requires the C-terminal cytosolic domain of the amyloid precursor protein.

Amyloid precursor protein (APP) is metabolized through at least three pathways: the constitutive secretory pathway, the endosomal-lysosomal pathway and the 4-kDa A beta-producing pathway. The 4-kDa A beta (4 kDa A beta)-producing pathway which may play a primary role in the pathogenesis of Alzheimer's disease (AD) is presently unknown. In the present paper, we examine the production of the 4 kDa A beta in K562 lymphoid cells transfected with a truncated APP695 construct (APP delta 652-695) encoding an APP which lacks the cytosolic C-terminal domain except the four N-terminal amino acids, KKKQ.

Eddy current correction in volume-localized MR spectroscopy.

The quality of volume-localized magnetic resonance spectroscopy is affected by eddy currents caused by gradient switching. Eddy currents can be reduced with improved gradient systems; however, it has been suggested that the distortion due to eddy currents can be compensated for during postprocessing with a single-frequency reference signal. The authors propose modifying current techniques for acquiring the single-frequency reference signal by using relaxation weighting to reduce interference from components that cannot be eliminated by digital filtering alone.

Changes in intervertebral disc cross-sectional area with bed rest and space flight.

Study Design: We measured the cross-sectional area of the intervertebral discs of normal volunteers after an overnight rest; before, during, and after 5 or 17 weeks of bed rest; and before and after 8 days of weightlessness.

Objectives: This study sought to determine the degree of expansion of the lumbar discs resulting from bed rest and space flight.

Summary Of Background Data: Weightlessness and bed rest, an analog for weightlessness, reduce the mechanical loading on the musculoskeletal system.

Ultrasound diagnosis of thymic hemorrhage in an infant with late-onset hemorrhagic disease.

Thymic hemorrhage related to coagulopathy by vitamin K deficiency is a rare condition. We report a case in a 4-week-old boy presenting with acute onset of respiratory distress and anemia. Ultrasound examination of a compressive anterior mediastinal mass established the diagnosis of thymic hemorrhage and allowed us to follow resolution under medical treatment.

A role for extracellular matrix degradation and matrix metalloproteinases in senile dementia?

In brain as in cartilage, the extracellular matrix contains aggregates formed by hyaluronic acid (HA) and proteoglycans. In osteoarthritic cartilage, release of the proteoglycans from the aggregates by cleavage of the HA-binding region results in the accumulation of the HA-binding region and in the fragmentation of the released proteoglycans. Stromelysin, a matrix neutral metalloproteinase, is one of the enzymes responsible for the cleavage of the HA-binding region.

MD Concept: a model for integrating medical knowledge.

Many integrated clinical information systems depend on large knowledge bases containing dictionary of terms as well as specific information about each term and the relationships between terms. We propose a knowledge base model called MD Concept which is based on a semantic network and uses an object-oriented paradigm and relational tables. A prototype has been developed which integrates the Unified Medical Language System (UMLS) with other databases including the Systematized Nomenclature of Medicine (SNOMED II), the Diagnostic and Statistical Manual of Mental Disorders (DSM-IIIR) and a pharmaceutical database.

Zinc and copper balances in healthy adult males during and after 17 wk of bed rest.

The effects of long-term bed rest on zinc and copper balances were measured in seven healthy men. Volunteers aged 22-54 y (mean +/- SD, 34 +/- 12 y), 168-185 cm in height (173 +/- 5 cm), and 64-86 kg in weight (74 +/- 9 kg) remained on a metabolic ward for 29 wk. Subjects were ambulatory during weeks 1-5, remained in continuous bed rest for weeks 6-22, and were reambulated during weeks 23-29.

Nutrition and human physiological adaptations to space flight.

Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements.

Propagation in the AV node: a model based on a simplified two-dimensional structure and a bidomain tissue representation.

A model is proposed to explain mechanisms of propagation in the atrioventricular (AV) node of the heart. The model is based on a simplified two-dimensional anatomic description of the central node region and on a bidomain tissue model for the propagation. The central region is described as a three-tissue compartment model; the proximal tissue composed of ANL cells, the central tissue composed of N cells and the distal tissue composed of NH cells.

Examining HIV-related knowledge among adults in the U.S.

Supplemental AIDS data from the 1987 National Health Interview Survey indicate that adults in the U.S. know the most frequent modes of HIV transmission, but lack a more comprehensive understanding of HIV and AIDS.

Prevention of space flight induced soft tissue calcification and disuse osteoporosis.

This paper emphasizes the devastating effects of displacement of calcium during space flight, due to increased bone turnover.