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Biomedical subjects

M Hanson

Publications and source records attributed to M Hanson.

At least 73 records · Page 4Linked to original sources

Autocrine/paracrine induction of tissue inhibitor of metalloproteinase-1 in Chinese hamster ovary cells by oncostatin M.

Chinese hamster ovary (CHO) cells expressing recombinant human oncostatin M (rOM) were found to secrete high levels of a 28-kDa protein. Sequence analysis of the protein suggested that it was hamster tissue inhibitor of metalloproteinase-1 (TIMP-1). In this study, we show that induction of TIMP-1 mRNA and protein by CHO cells is due to rOM action in an autocrine/paracrine mode. TIMP-1 expression in rOM-producing CHO cells increased concomitantly with methotrexate-induced rOM amplification. TIMP-1 upregulation was not caused by either transfection of nonspecific DNA nor was it a direct effect of treatment of the cells with methotrexate. These results suggest that oncostatin M is a potent inducer of TIMP-1 and that its receptor-mediated expression is conserved across species.

Animals↗

Firesetting during the preschool period: assessment and intervention issues.

OBJECTIVE: To describe a methodology of assessing preschoolers involved in firesetting incidents, and outline the psychiatric implications of firesetting incidents in young children. METHOD: To outline The Arson Prevention Program for Children and present case vignettes. RESULTS: The heightened risk of burn injury or fatality in fires caused by young children is highlighted and practical suggestions for facilitating the immediate safety of the child and family are presented. CONCLUSION: Despite the popular notion that fire interest and play is relatively benign in young children, the cases show that, as with older children, firesetting in preschoolers can be associated with serious child and/or family psychopathology.

Attention Deficit Disorder with Hyperactivity↗

Magnetic characterization of iron oxides for magnetic resonance imaging.

The OMP particle and four additional iron oxide samples were investigated in terms of zero field cooled magnetization (ZFCM) curves and hysteresis loops. The observation of superparamagnetic blocking and the absence of magnetic remanence demonstrated that the samples are superparamagnetic at room temperature. The magnitude of the ZFCM peak temperatures are in qualitative agreement with the iron oxide crystal size. One sample deviated from the remaining four in that it had a significantly lower magnetic moment and an irregular ZFCM curve showing the presence of various less magnetic phases. The similar results obtained with the OMP particles and the individual OMP crystallites without the polymer support show that the superparamagnetic properties of the individual OMP crystallites are retained on the OMP particle. Depending on the application, the ZFCM experiment may be viewed as an alternative or a supplement to Mössbauer spectroscopy in studies of the superparamagnetic blocking of iron oxides.

Contrast Media↗

Interactions of lysozyme with hydrophilic and hydrophobic polymethacrylate stationary phases in reversed phase chromatography (RPC).

Two silicas, one with a mean pore diameter of 30 nm and the other non-porous, were coated with polymethacrylates of increasing hydrophobicity in the sequence: poly-2-hydroxyethylmethacrylate (P2HEMA)1 polyethylmethacrylate (PEMA) and poly-n-octylmethacrylate (POMA). Association constants, Kass, between lysozyme and the coated silicas were determined by means of frontal analysis, and the apparent heats of adsorption, delta Happ, by means of microcalorimetry. Using Kass and delta Happ the changes in the apparent free energy, delta Gapp, and in the apparent entropy, delta Sapp, were calculated at a concentration of lysozyme < 10 mumol/l. The association between the lysozyme and the coated silica gave negative delta Happ and delta Sapp values. The delta Sapp values calculated from the experimental data in the absence of an added electrolyte and with 0.1 M sodium perchlorate present to be -12 (-96) J/mol deg on the P2HEMA silica, -27 (-51) J/mol deg on the PEMA silica, -98 (-186) J/mol deg on the POMA silica, respectively. The high delta Sapp value of the lysozyme on the POMA silica reflects a kind of stabilisation effect due to the conformational changes of lysozyme on the most hydrophobic POMA silica. As evidenced by RPC, lysozyme elutes on the POMA column in its totally unfolded form enabling a more disordered conformation with respect to entropy than in the native form.

Calorimetry↗

Patient-centered redesign. More collaborative clinical input into capital budget decisions.

As part of a restructuring program at a large, acute care hospital, a new, collaborative form of clinical management called triads has been initiated. Members of these collaborative management teams are being collectively empowered to better enable them to establish a continuously improving, cost-effective clinical service. This article describes the impact of this new structure on the capital budgeting process in changing a centralized, committee-based system of decision making with limited clinical nursing input to one that is increasingly decentralized, interdisciplinary, and focused on patients.

Budgets↗

Evaluation of clinical and laboratory aspects of antibody tests for detection of hepatitis C virus infection in blood donors and recipients from a low-risk population.

BACKGROUND: When the first-generation enzyme immunoassay (EIA) for detection of antibody to hepatitis C virus (anti-HCV) was approved in May 1990, blood banking agencies recommended testing of all components in inventory. In many cases, one or more components from these units had already been transfused. STUDY DESIGN AND METHODS: Donors that reacted in first-generation EIAs and recipients of their components were identified, and anti-HCV test methods (including first-generation EIA, second-generation EIA, and recombinant immunoblot assay [RIBA]) were evaluated. RESULTS: Of 66 donors identified as anti-HCV-positive by first-generation EIA, 17 were positive in second-generation EIA. Of these 17, 9 reacted in RIBA; 6 of these showed evidence of HCV infection in polymerase chain reaction (4) and/or probable transmission of HCV to a transfusion recipient (3). Of the 48 specimens that were positive in first-generation EIA and negative in second-generation EIA, only 1 was positive in RIBA; serum was not available for polymerase chain reaction testing, and there were no living transfusion recipients in whom to assess evidence of transmission of HCV. CONCLUSION: This study documents the low predictive value of EIAs for anti-HCV in a low-prevalence blood donor population and emphasizes the need for additional testing to confirm the specificity of samples that react in the screening tests.

Adolescent↗

Facilitating problem drinking clients' transition from inpatient to outpatient care.

Engaging and retaining problem drinkers in the helping process are among the most difficult tasks encountered by professionals working with alcoholic clients. The engagement process is particularly difficult for individuals who are referred for outpatient treatment following inpatient care. This article reports on the use of transition groups to improve the linkages between inpatient and outpatient alcoholism treatment. Findings revealed that clients who had access to a transition group had more favorable outcomes than did individuals who had no access to the group. The group was especially useful for inpatients who had encounters with the outpatient clinic before their hospitalizations. This investigation illustrates the positive impact of simple service adjustments on the delivery of care.

Adult↗

Delinquent firesetters: a comparative study of delinquency and firesetting histories.

Twenty-five male delinquents (aged nine to 16) who had legal charges for setting fires filed against them were compared to a group of age and sex matched delinquents who had legal charges filed against them that were not related to firesetting. Groups were compared on demographic variables and on their delinquency and fire related histories. The only significant difference to emerge was a higher proportion of past firesetting in the group with fire-related charges. The present results indicate that a subgroup of antisocial recidivist firesetters exists among young offenders and underscore the importance of obtaining a thorough fire related history from youth who are before the court on fire related charges.

Adolescent↗

MR and positron emission tomography in the diagnosis of surgically correctable temporal lobe epilepsy.

PURPOSE: To determine the association of an MR abnormality and a positron emission tomography (PET) abnormality with a good outcome in patients with temporal lobe epilepsy after lobectomy, the association of combined PET and MR findings with good outcomes after lobectomy, and MR and PET pathologic correlation. METHODS: MR and PET were performed on 27 patients in a blinded study. Histologic studies were correlated with foci of increased T2 signal. RESULTS: Increased signal or decreased volume of the hippocampus was noted in 13 of 15 patients with mesial temporal sclerosis. Twelve of 15 had positive PET findings. MR identified 20 (83%) of the 24 patients with good outcomes. PET identified 71%. When MR and PET were combined, they detected 95% of the patients with good outcome. Region of interest measurements of the hippocampus in 11 study patients and 7 control subjects documented a significant increase in signal in the patients with seizures. Histologic correlative studies demonstrated that increased T2 signals related to astrocytosis in the hippocampus and adjacent white matter. CONCLUSIONS: MR (increased signal and decreased volume of the hippocampus) significantly improved the capability to identify those persons who would be helped by lobectomy. MR sensitivity exceeded that of PET.

Adolescent↗

Blood donor screening. Factors influencing decision making.

A questionnaire assessing expert opinion on reducing the risk of transfusion-transmitted disease through selection and testing of blood donors was distributed to transfusion medicine professionals. A second questionnaire assessing the publics' perception of blood transfusion safety was distributed to selected nonexperts. Both groups agreed that recipient safety should be a priority. However, issues such as the impact of testing on the available donor pool, the psychosocial effects of donor deferral, and costs related to each risk-reduction strategy also must be considered. Evaluation of the associated cost as well as the expected benefit will not only assure the safety of blood recipients but also will contribute to controlling the cost of health care.

Blood Donors↗

Localization of tRNA genes on the Petunia hybrida 3704 mitochondrial genome.

22 tRNA genes corresponding to 17 tRNA species were localized on the master circle of Petunia hybrida mitochondrial (mt) DNA. Genes for trnN, trnM, trnS-GGA, trnW and trnH are of the 'chloroplast-like' type and presumably originate from promiscuous chloroplast (cp) DNA sequences inserted into the petunia mitochondrial genome. A comparison of the mt tRNAs or tRNA genes population present in two monocotyledonous plants (wheat and maize) and two dicotyledonous plants (petunia and potato) show slight differences in the genetic origin of individual tRNAs. The organization of the petunia mt tRNA genes as well as the number of tRNA gene copies, compared to other plant species, is discussed.

Anticodon↗

T-cell receptor V beta chain expression in patients with juvenile rheumatoid arthritis.

The V beta chain repertoire in peripheral blood T-cell was analyzed in 23 patients with juvenile rheumatoid arthritis (JRA). Of these, 15 patients had active disease as defined by tender and swollen joints. The ESR was elevated in all but three patients, C-reactive protein (CRP) was elevated in eight. Three patients were investigated during active and inactive phases of the disease. In the active phase of the disease T-cell composition was characterized by an increased number of CD4+ helper cells due to a marked increase in the CD4+CD45RA+ subgroup (34.0 +/- 10.9%, P < 0.001) and a decrease in CD8+CD29+ T-cells (10.3 +/- 5.6%, P < 0.05) compared to controls (15.4 +/- 10.0% and 17.8 +/- 12.3%, respectively). Using the monoclonal antibodies available to determine T-cell receptor (TCR) expression, patients with active disease demonstrated a significant predominance of T-cells bearing TCRs of the V beta 5 family as determined by flow cytometry (7.6 +/- 6.7 vs 3.4 +/- 1.3 in controls, P = 0.01). In active polyarthritis, up to 24% of peripheral blood T-cells expressed TCRs of the same family. In the majority of JRA patients and especially in non-active disease, no preferential TCRs were found compared to controls. However, even defining only a part of TCRs by immunofluorescence, in certain patients a preferential or dominant expression of a single V beta gene family in the T-cells was found, supporting the concept of an involvement of T-cells in the autoimmune pathogenesis of JRA.

Adolescent↗

Correlation of adenosine echocardiography and thallium scintigraphy.

Echocardiography and thallium-201 imaging with coronary vasodilators such as dipyridamole have been shown to be useful in detecting the presence and prognostic significance of coronary artery disease. Adenosine, a potent and direct coronary vasodilator, has a shorter physiologic half-life than dipyridamole, which exerts its effect by blocking the cellular uptake of adenosine. Because of the potential advantage of dipyridamole, we undertook this study to determine the correlation of adenosine echocardiography with thallium scintigraphy. Forty-two patients (18 men and 24 women; mean age 64) who were unable to undergo treadmill exercise and were known or suspected to have coronary artery disease were studied. A baseline echocardiogram was obtained in four standard views followed by adenosine infusion at a rate of 140 micrograms/kg/min for 6 minutes. Thallium-201 was administered 3 minutes into the infusion while a second echocardiogram was performed. Thallium-201 imaging was begun immediately after the infusion of adenosine and repeated 4 hours later. Sixteen patients underwent coronary angiography within 1 month of the adenosine echocardiogram and thallium-201 study. At the peak infused dose of adenosine there was a significant increase in heart rate (12 beats/min; p = 0.0001) and rate-pressure product (1.3 x 10(3) beats/min x mm Hg; p = 0.02) and statistically insignificant decreases in systolic and diastolic blood pressures. Sixty-two percent of patients experienced side effects during the adenosine infusion, with chest pain, shortness of breath, and flushing occurring most frequently. These side effects resolved within 1 to 2 minutes after the infusion was stopped. Ischemic electrocardiographic changes occurred in 19% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

Overview on drug and alcohol testing in the workplace.

A flashpoint in the debate over workplace responses to alcohol and drug use by members of the workforce centres on the chemical testing of current employees and job applicants for alcohol and drug use. Drug testing may be the most contentious issue faced by enterprises struggling to develop fair and effective programmes to deal with the consequences of substance use in the workplace. The present paper examines scientific evidence on the nature and extent of alcohol and drug use by members of the workforce, evidence linking alcohol and drug use to workplace problems, workplace strategies for managing alcohol- and drug-related difficulties, and arguments for and against drug and alcohol testing. To date, the evidence supportive of alcohol and drug testing is inconclusive. Testing programmes may be useful in identifying drug users in the workforce. Their deterrent value is uncertain, however, and they are not efficient tools for linking drug users to assistance programmes. Enterprises that are contemplating establishing testing programmes should consider: (a) whether substance use is a problem in their setting; (b) whether testing will respond to the problem; (c) the costs and benefits of testing; and (d) any ethical and legal questions raised by the programmes.

Cost-Benefit Analysis↗

ANP-mediated volume depletion attenuates renal responses in humans.

Brief low-dose infusions of atrial natriuretic peptide (ANP) that emulate physiological plasma concentrations in humans have little if any effect on renal excretory function. This study explored the possibility that ANP-mediated reductions in cardiac filling pressures (through ANP's rapid effect on capillary dynamics) could attenuate its purported renal effects. Protocol A consisted of 16 healthy subjects (ages 19-27 yr old) who underwent three consecutive 45-min experimental sequences: 1) placebo, 2) ANP (10 ng.kg-1 x min-1), and 3) ANP alone (n = 8) or ANP with simultaneous lower body positive pressure (LBPP, n = 8). Electrocardiogram and direct measures of arterial and central venous pressures were continuously monitored. Blood was sampled at the end of each 45-min sequence before subjects stood to void. Compared with control (placebo), ANP produced a hemoconcentration and increased plasma norepinephrine, but did not change heart rate, blood pressure, plasma levels of renin, aldosterone, or vasopressin, or renal excretion of volume or sodium. In subjects receiving LBPP to maintain central venous pressure during the last 45 min of ANP infusion, norepinephrine did not increase and urine volume and sodium excretion increased (P < 0.05). In a second study (protocol B), five healthy subjects received a placebo infusion for 45 min followed by two consecutive 45-min infusions of ANP (10 ng.kg-1 x min-1). Central venous pressure was maintained (LBPP) at placebo baseline throughout the two ANP infusion periods. Urine volume and sodium excretion rates increased progressively and significantly during both ANP infusion periods (P < 0.05) without significant changes in creatinine clearance, blood pressure, or heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗