Characteristics of vasopressin release during controlled reduction in arterial pressure.

Because of the interruption of the descending sympathetic nervous pathways, individuals with cervical spinal cord injury experience orthostatic hypotension when in an upright posture. The changes in hemodynamic parameters that occur during upright posture can be closely monitored and quantitated during progressive head-up tilting on a tilt table. We have utilized this method to assess the response of vasopressin and other vasoactive hormones to gradual, progressive reductions in arterial pressure and to identify possible threshold responses to baroreceptor stimulation in human subjects.

Complexation of iron cation by sodium urate crystals and gouty inflammation.

Gouty inflammation can be suppressed by an iron chelator. We therefore hypothesized that arthritis associated with sodium urate crystal deposition could follow the incomplete complexation of iron cation with subsequent oxidant generation as the metal cycles through reduced and oxidized states. Urate crystals adsorbed Fe3+ in vitro and crystals collected from a human tophus had significant concentrations of ionizable iron.

Case report: acute renal vein thrombosis in patients with spinal cord injury and secondary amyloidosis.

Chronic spinal cord injury, when complicated by chronic suppurative infections, has replaced chronic tuberculosis as a leading cause of secondary amyloidosis. Renal involvement with secondary amyloidosis is characterized by the presence of nephrotic range proteinuria and an increased incidence of renal vein thrombosis. Two cases of acute renal vein thrombosis associated with secondary amyloidosis in patients with spinal cord injury are presented.

Determining the accuracy of calculating systolic wall thickening using a fast Fourier transform approximation: a simulation study based on canine and patient data.

Unlabelled: The high court yields of 99mTc-sestamibi make possible the acquisition of multiple gated SPECT studies with relatively high count densities. By reorienting these studies into gated short-axis slices, and extracting the three-dimensional myocardial perfusion distribution, we can study wall thickening using an amplitude and phase analysis methodology that examines the change in counts throughout the cardiac cycle. There have been two main concerns raised about this count-based technique: (1) What effect does the sampling rate have on the calculation of systolic wall thickening? and (2) What effect does count density have on the calculation of systolic wall thickening?

Methods: We designed a simulation study using myocardial wall thickening data obtained from ultrasonic crystals implanted in the myocardium of a normal canine.

Autoerotic deaths: four cases.

We describe the circumstances and post mortem medical findings of 4 unusual fatalities where death occurred during autoerotic practice. Three cases occurred in young to middle-aged men--hanging, electrocution and inhalation of a zucchini. The manner of death in each was accidental.

Relationship of performance on the ERGOS work simulator to illness behavior in a workers' compensation population with low back versus limb injury.

A prospective blinded cohort study was performed to test for a difference in the pattern of physical activity factors measured with the ERGOS work simulator in subjects with low back injuries versus those with limb injuries. Also tested was the relationship between physical activity factors measured with the ERGOS and several psychological tests and measures of nonorganic pain behavior in subjects with low back pain. Subjects were 70 men, 22 to 64 years old, who attended a 2-week physical capacity assessment after undergoing rehabilitation for a work-related injury.

Pattern of performance in workers with low back pain during a comprehensive motor performance evaluation.

Study Design: Tests of limb and back motor performance were administered to males with low back pain at the completion of a back-school program.

Objectives: The objective of the study was to determine the relationship between such motor performance and the propensity for abnormal illness behavior as indicated by the Waddell score.

Summary Of Background Data: Previous studies in similar subjects had revealed a nonbiologic pattern of lumbar strength and movement in back-school patients, and correlations between lumbar variables, Waddell score, and 'global' psychologic measures.

CENP-C is required for maintaining proper kinetochore size and for a timely transition to anaphase.

The human autoantigen CENP-C has been demonstrated by immunoelectron microscopy to be a component of the inner kinetochore plate. Here we have used antibodies raised against various portions of CENP-C to probe its function in mitosis. We show that nuclear microinjection of anti-CENP-C antibodies during interphase causes a transient arrest at the following metaphase.

Multicenter trial validation for quantitative analysis of same-day rest-stress technetium-99m-sestamibi myocardial tomograms.

Unlabelled: The accuracy of an automated quantitative analysis of same-day rest/stress 99mTc sestamibi SPECT images for detection and localization of coronary artery disease (CAD) was assessed in a multicenter trial consisting of 161 patients from 7 different clinical sites utilizing various camera computer systems.

Methods: Of the 161 patients, 102 had angiographically documented coronary artery disease, 22 had normal coronary arteriograms, and 37 had a low (< 5%) likelihood of coronary artery disease based on their age, sex, symptoms and the results of their exercise electrocardiograms. The patients were studied using previously optimized image acquisition and processing protocols.

Oral ondansetron for preventing nausea and vomiting.

Available clinical data on the use of oral ondansetron for the prevention of nausea and vomiting in patients undergoing cancer chemotherapy or surgery are reviewed. Injectable ondansetron hydrochloride is very effective in preventing nausea and vomiting associated with even the most emetogenic antineoplastic drugs. In December 1992, 4- and 8-mg oral tablets (ondansetron hydrochloride dihydrate) became available.

Cycling fatalities in Western Australia.

Objective: To present a review of the circumstances of 64 cycling fatalities in Western Australia (WA) during the nine-year period 1984-1992, and the major injuries sustained by the cyclists.

Data Sources: The number of deaths was ascertained from lists maintained by the WA Police Department, Forensic Pathology Division of the Health Department and the Coroner's office. Individual case files held by the Coroner's office and Forensic Pathology Division were then examined for details of the circumstances of each incident, epidemiological data, and medical and toxicological findings.

Nuclear events of apoptosis in vitro in cell-free mitotic extracts: a model system for analysis of the active phase of apoptosis.

We have developed a cell-free system that induces the morphological transformations characteristic of apoptosis in isolated nuclei. The system uses extracts prepared from mitotic chicken hepatoma cells following a sequential S phase/M phase synchronization. When nuclei are added to these extracts, the chromatin becomes highly condensed into spherical domains that ultimately extrude through the nuclear envelope, forming apoptotic bodies.

Three-dimensional coronary angiography.

For at least two decades coronary cine-angiograms have been reviewed on film projectors. The cardiologist most often reviews the multiple two-dimensional projections of the coronary arterial tree on a screen, and then mentally create a three-dimensional (3-D) model of the patient's arteries. The ability to synthesize this data and grasp the three-dimensionality of a patient's specific anatomy is quite difficult and requires extensive training and experience to perfect.

Three-dimensional display of cardiac single photon emission computed tomography.

Similar to other cardiac imaging modalities, the quest for a three-dimensional display that can be used for visualizing cardiac single photon emission, computed tomography studies has resulted in several techniques: surface shading, surface modeling, and volume rendering. Each of these techniques has its own advantages and disadvantages. Surface shading yields displays that can be used to enhance a patient's or referring clinician's understanding of a diagnosis, but they are rarely used for diagnostic purposes.

Quantitative same-day rest-stress technetium-99m-sestamibi SPECT: definition and validation of stress normal limits and criteria for abnormality.

Gender-matched stress normal limits and criteria for abnormality for rest-stress 99mTc-sestamibi same-day myocardial perfusion imaging were developed and validated in 160 patients who were imaged using previously developed optimized acquisition, processing and quantitative protocols. The gender-matched mean and standard deviation of the normal response were calculated using 35 male and 25 female patients with a < 5% likelihood of coronary artery disease. Receiver-operating curve analysis using expert visual interpretation as the "gold standard" was used to determine the optimal criteria for abnormality detection, in terms of standard deviations from the mean and minimum defect size for each of the four major zones of the polar map, in a pilot population consisting of an additional 35 male and 25 female patients with a variety of perfusion defects.

Vasopressin-independent alterations in renal water excretion in quadriplegia.

Postural effects on water excretion are known to be increased in patients with cervical spinal cord injury and may result in marked impairment of the ability to excrete a water load, especially in erect posture. Both vasopressin-dependent and vasopressin-independent mechanisms have been implicated. To assess the roles of these mechanisms and further identify the factors involved in the renal response to erect posture, sustained water loading studies were performed on 11 quadriplegic subjects and 9 healthy control subjects, supine and erect (sitting).

Concurrent validity of the ERGOS work simulator versus conventional functional capacity evaluation techniques in a workers' compensation population.

A prospective blinded cohort study was performed in an interdisciplinary vocational evaluation program to investigate the concurrent validity of the ERGOS work simulator in comparison to current methods of evaluation. Seventy men and eight women, aged 22 to 64 years, who attended for a 2-week physical capacity assessment participated in the study. Physical activity factors as defined by the Canadian Classification and Dictionary of Occupations and the American Dictionary of Occupational Titles were assessed for all subjects under three evaluation conditions: the ERGOS work simulator, an exercise-oriented physical evaluation by a rehabilitation therapist, and performance of project-format industrial tasks.

Reversible vasopressin deficiency in severe hypernatremia.

Studies to assess the relationship between plasma arginine vasopressin concentration (Pavp) and plasma osmolality (Posm) were performed on an elderly patient with dementia who developed severe hypernatremia due to inadequate water intake following a debilitating hip fracture. Serum sodium concentrations were 174 and 196 mEq/L on two consecutive hospital admissions. During the second of these admissions, sequential measurements of Pavp and Posm were obtained as hypernatremia was gradually corrected.

Evidence that generation of inositol 1,4,5-trisphosphate and hydrolysis of phosphatidylinositol 4,5-bisphosphate are rapid responses following addition of fungal elicitor which induces phytoalexin synthesis in lucerne (Medicago sativa) suspension culture cells.

Treatment of lucerne suspension culture cells with glycoprotein elicitor from the phytopathogenic fungus Verticillium albo-atrum R & B triggers Ca(2+)-mediated induction of antimicrobial secondary metabolites termed phytoalexins. The present study investigated the possible role of polyphosphoinositide signal transduction in phytoalexin elicitation. Within 1 min of addition of elicitor to lucerne suspension culture cells we found a 100-160% (15-25 pmol/g fresh wt) increase in the level of compound with chromatographic and electrophoretic properties expected for an inositol trisphosphate (InsP3) and which was strongly bound by an inositol 1,4,5-trisphosphate (Ins(1,4,5)P3)-specific binding protein; after 3 min the level of this compound had fallen below that observed prior to elicitor challenge.

Expression of the La Crosse M segment proteins in a recombinant vaccinia expression system mediates pH-dependent cellular fusion.

To study the expression of La Crosse virus (LAC) glycoproteins, G1 and G2, we constructed a cDNA copy of the open reading frame (ORF) of the middle RNA segment and expressed it in a recombinant vaccinia virus (VV.ORF). Cells infected with VV.

Mapping DNA within the mammalian kinetochore.

The location of the cis-acting DNA sequences that direct the assembly of the mammalian kinetochore is not known. A variety of circumstantial evidence, however, has led to the widespread belief that they are present throughout the kinetochore including the kinetochore outer plate. To investigate this question directly, we have used two independent methods to localize DNA in and around the mammalian kinetochore.

Coexistence of anti-neutrophil cytoplasmic antibody-associated glomerulonephritis and membranous glomerulopathy.

The association of renal Wegener's granulomatosis with other glomerular diseases is very rare. A case of anti-neutrophil cytoplasmic antibody-associated necrotizing glomerulonephritis superimposed on a membranous glomerulopathy in a patient with systemic Wegener's granulomatosis is reported. Renal failure was corrected by immunosuppressive therapy treatment, but a non-nephrotic-range proteinuria persisted for several months.

Metabolic cost and efficiency in two forms of squatting exercise in children and adults.

These experiments investigated the oxygen consumption and work efficiency of adults and children performing identical movement patterns. Adult men (mean age 24) and male children (mean age 12) performed squatting exercises with and without a pause at the lowest point of the squat. The former were termed no rebound squats and the latter were termed rebound squats.

Definition of the upstream efficiency element of the simian virus 40 late polyadenylation signal by using in vitro analyses.

The polyadenylation signal for the late mRNAs of simian virus 40 is known to have sequence elements located both upstream and downstream of the AAUAAA which affect efficiency of utilization of the signal. The upstream efficiency element has been previously characterized by using deletion mutations and transfection analyses. Those studies suggested that the upstream element lies between 13 and 48 nucleotides upstream of the AAUAAA.