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Biomedical subjects

J Strong

Publications and source records attributed to J Strong.

At least 37 records · Page 2Linked to original sources
PubMed1995

The Warfarin-Aspirin Symptomatic Intracranial Disease Study.

We conducted a retrospective, multicenter study to compare the efficacy of warfarin with aspirin for the prevention of major vascular events (ischemic stroke, myocardial infarction, or sudden death) in patients with symptomatic stenosis of a major intracranial artery. Patients with 50 to 99% stenosis of an intracranial artery (carotid; anterior, middle, or posterior cerebral; vertebral; or basilar) were identified by reviewing the results of consecutive angiograms performed at participating centers between 1985 and 1991. Only patients with TIA or stroke in the territory of the stenotic artery qualified for inclusion in the study. Patients were prescribed warfarin or aspirin according to local physician preference and were followed by chart review and personal or telephone interview. Seven centers enrolled 151 patients; 88 were treated with warfarin and 63 were treated with aspirin. Median follow-up was 14.7 months (warfarin group) and 19.3 months (aspirin group). Vascular risk factors and mean percent stenosis of the symptomatic artery were similar in the two groups, yet the rates of major vascular events were 18.1 per 100 patient-years of follow-up in the aspirin group (stroke rate, 10.4/100 patient-years; myocardial infarction or sudden death rate, 7.7/100 patient-years) compared with 8.4 per 100 patient-years of follow-up in the warfarin group (stroke rate, 3.6/100 patient-years; myocardial infarction or sudden death rate, 4.8/100 patient-years). Kaplan-Meier analysis showed a significantly higher percentage of patients free of major vascular events among patients treated with warfarin (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Coping with chronic low back pain: an idiographic exploration through focus groups.

OBJECTIVE: This article explores the coping construct held by individuals with chronic low back pain. The research addresses two criteria identified as important for coping research: it looks at people's appraisals and responses to the specific stressor of living with chronic low back pain, and it seeks to identify what these individuals actually think and do in response to the ongoing stressor of living with chronic pain. METHOD: Fifteen people with chronic low back pain who responded to a media release participated in focus group discussions on coping with chronic pain. RESULTS: Analysis indicated the desirability, if not need, for a somatic focus, the reliance on higher order cognitive strategies for planful action, and the use of a varied repertoire of coping strategies. CONCLUSIONS: These findings are discussed both in terms of adjustment to chronic illness and in relation to current pain management practices.

Activities of Daily Living↗
PubMed1995

Opportunity costs associated with long decision making.

In certain cases, prompt utilization of an already negotiated group purchasing agreement will save a hospital more money than bidding out the same products. This occurs because there are large opportunity costs associated with not taking savings immediately. Savings can be further enhanced by redeploying staff to contract for items not covered by group agreements.

Contract Services↗
PubMed1994

Chronic low back pain: toward an integrated psychosocial assessment model.

This study reports on the integration of 6 dimensions of chronic low back pain to provide a multidimensional profile of the patient. These dimensions were pain intensity, functional disability, attitudes toward pain, pain coping strategies, depression, and illness behavior. Cluster analysis of the data obtained from 100 patients with chronic low back pain revealed the presence of 3 distinct patient groups: patients who were in control, patients who were depressed and disabled, and patients who were active copers with high denial. The validity of these clusters was supported by significance testing on several external variables.

Adaptation, Psychological↗
PubMed1994

Function and the patient with chronic low back pain.

OBJECTIVE: To undertake a comparative examination of the reliability and validity of two frequently used self-report measures of functional disability, the Pain Disability Index (PDI) and the Oswestry Low Back Pain Disability Questionnaire (OLBPDQ). DESIGN: A descriptive ex-post facto design was used in the study. SETTING: Pain clinics and neurosurgical units at three metropolitan hospitals. SUBJECTS: One hundred patients with chronic low back pain of noncancer origin were administered the two questionnaires as part of a larger questionnaire battery. RESULTS: Acceptable internal consistency values of 0.76 for the PDI and 0.71 for the OLBPDQ were obtained. A correlation of r = 0.63 was found between the PDI and the OLBPDQ, supporting the concurrent validity of the two scales. Both the scales were found to be correlated to the Beck Depression Inventory scores (PDI, r = 0.42; OLBPDQ, r = 0.39), with higher disability associated with greater depression. Only the total PDI score was found to be sensitive to functional status differences within the patient sample. CONCLUSIONS: These findings support other recent work in favor of the PDI. The PDI had a slightly higher internal consistency and was more sensitive than the OLBPDQ.

Adult↗
PubMed1994

A comparison of lesions in small intracerebral arteries among Japanese men in Hawaii and Japan.

BACKGROUND AND PURPOSE: This report examines the hypothesis that the higher risk of stroke among Japanese men in Japan compared with those in Hawaii is related to pathology in small intracerebral arteries by comparing the prevalence of such lesions in autopsied participants from two cohorts of Japanese men in Japan and Hawaii. METHODS: Existing histological sections from the left basal ganglia from 232 men from Japan and 175 men of Japanese ancestry in Hawaii were examined for selected abnormalities in arteries between 100 and 300 microns in diameter by three pathologists. The presence of lacunar infarcts was also noted, and information about cerebral infarcts, cerebral hemorrhages, and atherosclerosis in the circle of Willis was available for the Hawaii group. RESULTS: Lacunar infarcts and all small intracerebral artery lesions except medial fibrosis were more common at every age in Japan than in Hawaii. By cause of death, all lesions were three or more times more prevalent among men who died of stroke than of noncardiovascular causes in both areas. In the Hawaii group, the small intracerebral artery lesions were significantly associated with autopsy evidence of cerebral and lacunar infarcts, and with atherosclerosis in the large arteries of the circle of Willis. Among a large number of risk factors measured at the baseline examination in Hawaii, only high blood pressure and reported usual Asian diet were significantly associated with one or more measures of small intracerebral artery lesions. CONCLUSIONS: An overview of the accumulated data indicated that small intracerebral artery pathology plays an important role in the high risk of stroke in Japanese men in Japan compared with those in Hawaii. These studies support the idea that hypertension is a necessary factor in the causal pathway, but also indicate that some other factors are involved. Some aspect of an Asian diet continues to be of importance for future research.

Age Factors↗
PubMed1993

Serum stimulation of UDP-glucose dehydrogenase activity in Swiss 3T3 fibroblasts.

A new HPLC assay was developed to measure UDP-glucose dehydrogenase (UDP-GDH) activity in crude homogenates of 3T3 fibroblasts. UDP-GDH activity is directly related to the proliferative activity of the cell culture: enzyme activity is highest in log phase cells and decreases as the culture approaches quiescence. Serum stimulation of quiescent 3T3 fibroblasts results in an increase in UDP-GDH activity that has two components that are differentially affected by inhibitors of protein synthesis. Following serum stimulation, changes in cellular UDP-glucuronic acid concentrations mirror changes in UDP-GDH activity. UDP-xylose is a potent inhibitor of UDP-GDH but inhibitory concentrations of UDP-xylose could not be detected in cell extracts.

3T3 Cells↗
PubMed1991

Cytoplasmic components of acetylcholine receptor clusters of cultured rat myotubes: the 58-kD protein.

A 58-kD protein, identified in extracts of postsynaptic membrane from Torpedo electric organ, is enriched at sites where acetylcholine receptors (AChR) are concentrated in vertebrate muscle (Froehner, S. C., A. A. Murnane, M. Tobler, H. B. Peng, and R. Sealock. 1987. J. Cell Biol. 104:1633-1646). We have studied the 58-kD protein in AChR clusters isolated from cultured rat myotubes. Using immunofluorescence microscopy we show that the 58-kD protein is highly enriched at AChR clusters, but is also present in regions of the myotube membrane lacking AChR. Within clusters, the 58-kD protein codistributes with AChR, and is absent from adjacent membrane domains involved in myotube-substrate contact. Semiquantitative fluorescence measurements suggest that molecules of the 58-kD protein and AChR are present in approximately equal numbers. Differential extraction of peripheral membrane proteins from isolated AChR clusters suggests that the 58-kD protein is more tightly bound to cluster membrane than is actin or spectrin, but less tightly bound than the receptor-associated 43-kD protein. When AChR clusters are disrupted either in intact cells or after isolation, the 58-kD protein still codistributes with AChR. Clusters visualized by electron microscopy after immunogold labeling and quick-freeze, deep-etch replication show that, within AChR clusters, the 58-kD protein is sharply confined to AChR-rich domains, where it is present in a network of filaments lying on the cytoplasmic surface of the membrane. Additional actin filaments overlie, and are attached to, this network. Our results suggest that within AChR domains of clusters, the 58-kD protein lies between AChR and the receptor-associated 43-kD protein, and the membrane-skeletal proteins, beta-spectrin, and actin.

Animals↗
PubMed1991

Pain intensity measurement in chronic low back pain.

This study investigated the psychometric properties of eight pain intensity measures used with chronic low back pain patients. All measures were similar in terms of scale distribution and rates of incorrect responses, with all scales apart from the Pain Rating Index significantly correlated. Principal axis factoring of data from 92 patients indicated the presence of one general factor on which all pain intensity measures except the Pain Rating Index loaded. The 101-point Numeric Rating Scale and the Box Scale had the strongest relationship, with loadings of 0.90. The Numeric Rating Scale and the Box Scale appear to be the scales of choice for the measurement of pain intensity in the low back pain patient.

Adult↗
PubMed1990

Quick-freeze, deep-etch replication of cells in monolayers.

We have made several technical improvements for quick-freeze, deep-etch replication of monolayers of cells grown on, or attached to, glass coverslips. Cells studied include muscle cells of rat and Xenopus cultured on glass coverslips, and erythrocytes attached to coverslips coated with poly-L-lysine. We describe methods for identifying particular areas of cultures, e.g., clusters of acetylcholine receptors on muscle cells, by light microscopy and then relocating these areas after replication. For good preservation of structure by quick-freezing, it is necessary to ensure that the surface to be frozen is covered by a minimum depth of water (less than 10 microns). Insufficient or excess water left on the sample during freezing causes recognizable artifacts in its replica. We describe two ways to control the water table--one by improving visual control of water removal, the other by blowing excess water off the sample surface with a jet of nitrogen applied during its descent to the freezing block. Finally, we describe a new specimen holder that allows us to etch and replicate six samples at once with good thermal contact between the stage and samples.

Animals↗
PubMed1990

Hepatic low density lipoprotein receptors, HMG-CoA reductase, and plasma lipids and apolipoproteins in high- and low-responding rhesus monkeys: effect of cholestyramine treatment.

Plasma lipids and apolipoproteins, and hepatic LDL receptor and HMG-CoA reductase activities in biopsy samples were measured in high- and low-responding rhesus monkeys maintained on a cholesterol-rich and regular diets. The effect of a 30-day cholestyramine treatment on the above parameters under both dietary conditions was also determined. On the cholesterol-rich diet the high-responders, when compared to the low-responders, had several-fold increased plasma cholesterol and apoB concentrations and significantly lower HDL apoA-I and cholesterol concentrations. Hepatic LDL receptor and HMG-CoA reductase activities were not detectable in the high-responders, while the low-responders expressed a reduced number of LDL receptors of normal affinity. Administration of cholestyramine resulted in a rapid induction of the hepatic LDL receptors in the high-responders and a small additional increase in the low-responders. Cholestyramine treatment also stimulated the expression of the hepatic HMG-CoA reductase in both groups of monkeys. These changes were accompanied by a dramatic drop in plasma cholesterol and apoB concentrations in the high-responders and, to a lesser extent, in the low-responders. Plasma HDL concentrations in the high-responders rose to levels higher than those seen in the low-responders. The affinity and receptor number were similar in both groups of monkeys on the control diet, but the low-responders had significantly higher HMG-CoA reductase activities. Administration of cholestyramine during the control diet had a small but significant additional effect on the hepatic LDL receptors of the low-responders but not of the high-responders.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Orthognathic surgery. Restoring form and function of the jaw.

Orthognathic surgery can achieve positive changes in a patient's facial appearance and functional abilities. Motivated patients seek this elective treatment, which requires a long-term commitment. By understanding the surgical techniques involved, the perioperative nurse can plan intraoperative care better and help these individuals reach their goals.

Adolescent↗
PubMed1988

Uptake and metabolism of myo-inositol by L1210 leukaemia cells.

The initial rate of uptake of [3H]myo-inositol by L1210 murine leukaemia cells is directly proportional to the extracellular concentration and unaffected by several analogues of myo-inositol even at millimolar concentrations. Scyllitol, a geometric isomer of myo-inositol, partially inhibited the uptake of myo-inositol (40% at 0.1 mM). A portion of the uptake of myo-inositol was not inhibited even at 5 mM-scyllitol. At steady-state the intracellular concentration of [3H]myo-inositol is directly proportional to the extracellular concentration. Addition of myo-inositol to medium does not enhance the growth of L1210 cells; these cells can maintain an extracellular concentration of 20 microM-myo-inositol even when grown in myo-inositol-free medium. Synthesis of myo-inositol from glucose by L1210 cells was demonstrated by use of [13C]glucose and m.s. L1210 cells maintain myo-inositol pools by a combination of synthesis de novo and uptake of exogenous myo-inositol by either passive diffusion or a low affinity carrier.

Animals↗
PubMed1988

Membrane domains of AChR clusters of cultured rat myotubes revealed by rapid-freeze, deep-etch, rotary-replication.

Acetylcholine receptor clusters of cultured rat myotubes are examined by thin-section EM and by rapid-freeze, deep-etch, rotary-replication technique to observe the cortical cytoskeleton; AChR are localized by binding of fluorescent toxin. Cluster membrane is composed of three types of membrane domain which interdigitate with each other. The AChR domain is rich in the integral membrane receptor, lies further from the substrate than the other two, and is overlain by an extensive irregular meshwork of anastomosing filaments containing actin and a beta isoform of spectrin. Contact domains resemble focal contacts of fibroblasts, in that membrane lying close to the substrate is overlain by bundles of actin filaments running parallel to the membrane; some finer filaments link the parallel filaments to each other and to the membrane. Coated-membrane domains are overlain by polymerized clathrin and, like contact domains, lie close to the substrate and have external connections to it; these domains are associated with coated vesicles, but not with intracellular filaments. The three domains have few if any connections to each other, and occupy mutually exclusive territories in the cluster.

Actin Cytoskeleton↗
PubMed1985

Mechanism of DNA strand breaks by mitonafide, an imide derivative of 3-nitro-1,8-naphthalic acid.

The metabolism and the mechanism of action of 5-nitro-2-(2-dimethylaminoethyl)-benzo(de) isoquinoline-1,3-dione (mitonafide), a nitro-containing antitumor drug, have been studied. Incubation of mitonafide under anaerobic conditions with rat liver microsomes and NADPH formed the fully reduced amine metabolite, 5-aminomitonafide. The formation of the amine metabolite was not inhibited by SKF-525A, metyrapone or piperonyl butoxide, indicating that the cytochrome P-450 was not involved in this reduction. Incubation of mitonafide with rat liver microsomes and NADPH under aerobic conditions stimulated oxygen consumption; piperonyl butoxide, SKF-525A, superoxide dismutase and catalase had no effect on this stimulation. Both mitonafide and 5-aminomitonafide were found to bind to DNA in a similar manner. However, in inducing single-stand breaks in the DNA of L1210 cells mitonafide was 10-fold more potent than 5-aminomitonafide. These results suggest that metabolic activation of mitonafide to species other than that of the amine metabolite may play a significant role in the induction of DNA damage and the biological activity of the drug.

Animals↗
PubMed1985

Regional measurements of [14C]misonidazole distribution and blood flow in subcutaneous RT-9 experimental tumors.

Regional [14C]misonidazole-derived radioactivity (MISO*) was measured by quantitative autoradiography in s.c. RT-9 experimental tumors 0.5, 2, and 4 h after an i.v. bolus (25 mg) and constant infusion (10 mg/h) in rats. Misonidazole (MISO) concentration in plasma, tumor, and other tissues was also measured by high-pressure liquid chromatography. The distribution of MISO* in the tumors always resulted in a characteristic pattern with high peripheral and low central values. The high-activity regions in the tumor rim achieved tissue: plasma MISO* activity ratios of 0.97 and 2.2 by 0.5 and 4 h, respectively; for central tumor regions, this ratio was 0.20 and 0.32 for the same periods, respectively. The limited distribution of MISO* to central tumor regions could be correlated to low values of blood flow (measured with [131I]iodoantipyrine) and to diffusion from peripheral tumor regions. Low blood flow in the central regions of these tumors will significantly limit the distribution of MISO and other drugs to viable-appearing cells in these areas and could account in part for the failures of chemotherapy in certain solid tumors. Pharmacokinetic modeling indicates that 1 to 9 h may be necessary for MISO concentrations in some tumor regions to reach 50% of that in plasma.

Animals↗