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Biomedical subjects

A Spitzer

Publications and source records attributed to A Spitzer.

At least 55 records · Page 3Linked to original sources
PubMed1995

Social support: how does it really work?

This study examines social support effect on stress and adaptation through the mediating effect of control. Participants in the study were 12 male and 65 female rheumatoid arthritis patients who were being treated in the outpatient clinics of three large hospitals in Israel. Findings suggest that social support did have a significant effect on stress and adaptation, though this effect was through the mediating effect of control and not as a buffer as was suggested previously. Implications of the results for nursing science are discussed.

Adaptation, Psychological↗
PubMed1995

Stimulation of sudomotor axon reflex mechanism by carbachol in healthy subjects and patients suffering from diabetic polyneuropathy.

Sudomotor axon reflex (SAR) mechanism was stimulated by percutaneous iontophoresis of carbachol in healthy subjects and patients suffering from diabetic polyneuropathy (PNP) of differing severity (stage I-III). SAR response was assessed by hygrometry and compared with histamine induced neurogenic vasodilation (laser-Doppler flowmetry) and itching sensation (visual analogue scale), which may provide information on neuro-secretion and afferent function of nociceptive unmyelinated nerve fibers. Carbachol induced long lasting SAR response with maximal sweating rates 20-30 minutes after stimulus onset. In diabetic patients the carbachol induced SAR response and the histamine induced itching sensation were significantly reduced in stage III of PNP. In contrast, histamine induced vasodilatation was significantly impaired in all stages of PNP. It is concluded that prolonged SAR response following iontophoresis of carbachol can simplify evaluation of sudomotor function when compared to established tests using intradermal application of acetylcholine. Furthermore, to demonstrate impairment of unmyelinated nerve fibers in PNP, histamine induced vasodilatation was found to be more sensitive than SAR response.

Adult↗
PubMed1995

School-age children's perceptions of mental illness.

The purpose of this study was to describe how school-age children perceive mental illness. The specific aims of this study were to describe the impact of age and sex on children's ability to identify and classify deviant behavior, and to identify how school-age children perceive mental illness by looking at how they define the concept, characterize the mentally ill, and understand causality and treatment. The random sample consisted of 90 school-age children. Thirty children were in grade 1, 30 in grade 4, and 30 in grade 7. A multimethods approach combining qualitative and quantitative techniques was used to analyze data. Major study findings indicated that age was not a significant factor in children's ability to classify deviant behavior; however, there was a sex main effect: Boys were able to better identify deviant behaviors than girls. A developmental trend was noted in children's ability to be aware of what mental illness is, to acknowledge characteristics of people who are mentally ill, to differentiate between mental illness and mental retardation, to identify various etiologies of mental illness, and to choose appropriate treatment modalities.

Adolescent↗
PubMed1995

Internal body perceptions of Ethiopian Jews who emigrated to Israel.

Previous research regarding knowledge about internal organs among school-age children tied this knowledge to the development of cognitive capabilities. Studies have rarely considered the impact of culture on this knowledge. The purpose of this study was to examine internal body perceptions among Ethiopian Jews who emigrated to Israel. A total of 65 children (stratified according to age) and 19 adults were interviewed. Findings indicated that Ethiopian children reported fewer body organs than did Western children. Further, Ethiopian children and adults, unlike people from Western societies, did not think about the body in terms of different biophysical functions. Rather, they perceived the body as a holistic system in which a divine providence was responsible for body organs working together harmoniously. Implications of the differing perceptions about internal body organs, health, illness, and treatment are discussed.

Adolescent↗
PubMed1995

School-age children's understanding of the relations between their behavior and their asthma management.

This research examined the behaviors children reported to be linked to their asthma flare-ups, the extent to which reported links were in the theoretically expected direction, explanatory models children gave for linkages they espoused, and the extent to which reporting a greater number of theoretically appropriate linkages was associated with a variety of asthma-related beliefs and behaviors. Most children reported that their behavior had an affect on their breathing and most often the reported impact was in theoretically expected directions (73%-100%). The ability of children to provide substantive explanatory models was more limited. Significant relationships were found between the child's number of theoretically appropriate affirmative responses and several subsequent measures of asthma knowledge, extent of child's responsibility to implement daily asthma management by both parent and child report, child's self-efficacy rating on his or her ability to perform asthma self-management activities, and the child's report of frequency with which routine asthma management behaviors were performed.

Adolescent↗
PubMed1994

Sequential occurrence of IgA nephropathy and Henoch-Schönlein purpura: support for common pathogenesis.

We report a patient who developed Henoch-Schönlein purpura (HSP) 13 years after he presented with IgA nephropathy (IgAN). In both HSP and IgAN renal biopsy most commonly reveals focal proliferative glomerulonephritis on light microscopy and immunofluorescence displays mesangial IgA deposits. In addition, patients with HSP or IgAN have elevated serum IgA levels, circulating IgA immune complexes, IgA-bearing lymphocytes, immunoglobulin-producing cells, and binding of IgG to glomerular components of similar molecular weight. The occurrence of both diseases in the same patient or the same families and the presence of immune abnormalities compatible with HSP or IgAN in relatives of patients with these diseases suggest a common pathogenesis.

Adult↗
PubMed1994

High-frequency jet versus conventional ventilation in infants undergoing Blalock-Taussig shunts.

Nine infants undergoing modified Blalock-Taussig shunts were randomized to both high-frequency jet ventilation (HFJV) and conventional ventilation (CV). Vital signs, blood gases, mean airway pressure, lung mechanics, functional residual capacity, and lung movement were compared on both modes of ventilation keeping peak inspiratory and expiratory pressures constant. The mean airway pressure was lower on HFJV than on CV (8.5 versus 10.9 cm H2O). Arterial partial pressure of oxygen was greater on HFJV than on CV (55 versus 46 mm Hg), arterial partial pressure of carbon dioxide was lower on HFJV than on CV (28 versus 37 mm Hg), whereas compliance (0.54 versus 0.56 mL.cm H2O-1.kg-1). resistance (110 versus 95 cm H2O/L.s), and functional residual capacity (23 versus 22.5 mL/kg) remained the same. Lung movement and degree of retraction necessary for surgical exposure as evaluated by an independent observer was less with HFJV compared with CV. Compared with CV during the creation of Blalock-Taussig shunts, HFJV provides better gas exchange at lower mean airway pressure with similar lung function, lung volume, and hemodynamics.

Airway Resistance↗
PubMed1994

Are affective disorders associated with alterations of heart rate variability?

A standardized heart rate analysis was carried out in unmedicated patients with major depression, melancholic type (n = 16), panic disorder (n = 16), reactive depression with suicide attempts during the preceding 24 h (n = 16) and in 16 normal control subjects. The investigations included time- and frequency-derived measurements of heart rate variability. In the patients with reactive depression, no differences could be detected as compared with the control group. The patients with panic disorder showed a significantly increased low-frequency band of spectral analysis (P < 0.01) and a marginally significant increment of heart rate (P = 0.05), probably indicating predominance of sympathetic control of heart rate. In the patients with major depression, we found significantly lower values of heart's beat-to-beat intervals and of the high-frequency peak of spectral analysis than in the other groups (P < 0.025), indicating decreased parasympathetic activity.

Adjustment Disorders↗
PubMed1994

Enhanced rates of cleavage and development for sheep zygotes cultured to the blastocyst stage in vitro in the absence of serum and somatic cells: amino acids, vitamins, and culturing embryos in groups stimulate development.

The aim of this study was to develop a serum-free culture system that could support high levels of cleavage and blastocyst formation from sheep zygotes developed in vitro. To this end, we investigated the effects on sheep zygote development of amino acids, ammonium, vitamins, and culture of embryos in groups in Synthetic Oviduct Fluid (SOF) medium supplemented with BSA (32 mg/ml). The inclusion of amino acids in the culture medium had no effect on the percentage of embryos arrested at the 8-16-cell stage when embryos were cultured singly in the same drop of medium for 6 days (43% in SOF; 41% in SOF+amino acids). However, in medium containing all Eagle's amino acids, replacing the culture medium every 48 h to alleviate ammonium toxicity significantly decreased the number of arrested embryos (6%; p < 0.05) and significantly increased blastocyst cell number (52 cells in SOF; 105 cells in SOF+amino acids; p < 0.01) and the number of embryos developing to the blastocyst stage (29% in SOF; 67% in SOF+amino acids; p < 0.05). When the medium was renewed every 48 h, nonessential amino acids and glutamine also significantly decreased the number of arrested embryos (p < 0.05). Culturing embryos singly or in groups in SOF medium with all Eagle's amino acids that was renewed every 48 h resulted in significant increases in blastocyst hatching and mean cell number (47%, 31%, and 79%; 105, 136, and 173 cells for embryos cultured singly, in groups of 2, and in groups of 4, respectively). After culture in groups of 4, blastocyst cell numbers were equivalent to in vivo-developed controls (160 cells) and significantly greater than those developed in serum (103 cells; p < 0.01). Analysis of blastocyst metabolism, expressed on a per-cell basis, revealed that amino acids did not affect either glucose uptake or lactate production, whereas the addition of amino acids and vitamins resulted in a significant increase in both parameters (p < 0.01). A similar response was observed in serum-derived blastocysts. Ammonium production by sheep blastocysts after culture in the presence of amino acids was significantly greater than that produced by mouse blastocysts, indirect evidence that ruminant embryos utilize amino acids to a greater extent than do rodent embryos.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1994

NMR-visible intracellular P(i) and phosphoesters during regulation of Na(+)-P(i) cotransport in opossum kidney cells.

There is an inverse relationship between intracellular concentration of P(i) ([P(i)]i) in the kidney and maximum velocity (Vmax) of Na(+)-P(i) cotransport in brush-border membrane vesicles both in P(i)-deprived and growing animals. However, at any given [P(i)]i, the Vmax is substantially higher in growing than in P(i)-deprived animals. This suggests that growth and P(i) depletion act on P(i) transport via different mechanisms. We tested this hypothesis by measuring the nuclear magnetic resonance-visible phosphate and the Vmax of Na(+)-P(i) cotransport in proximal tubule-like cells [opossum kidney (OK) cells] cultured in vitro. OK cells incubated in 1 mM extracellular P(i) had a [P(i)]i of 1.1 +/- 0.2 mM and a P(i) uptake of 1.47 +/- 0.06 nmol/mg in 5 min. Exposure of OK cells to P(i)-free medium decreased [P(i)]i by 80 +/- 7% (P < 0.01) and stimulated P(i) transport by 34 +/- 7% (P < 0.05). Exposure of OK cells to 10(-8) M insulin-like growth factor I (IGF-I) increased P(i) transport by 25 +/- 8% (P < 0.05) but did not affect [P(i)]i. The stimulation of Vmax produced by IGF-I was additive to that due to P(i) restriction. In addition, P(i) deprivation decreased the phosphomonoesters by 0.66 +/- 0.04-fold (P < 0.05) and increased the phosphodiesters by 2.5 +/- 0.5-fold (P < 0.01). Treatment with IGF-I increased both the phosphomonoesters (1.2 +/- 0.1-fold) and the phosphodiesters (4.1 +/- 0.6-fold). These results support the assumption that low P(i) supply and IGF-I stimulate Na(+)-P(i) cotransport by independent mechanisms.

Animals↗
PubMed1993

The fractional excretion of urea: a new diagnostic test for acute renal allograft rejection.

Fractional excretion of sodium (FENa) has been used in the diagnosis of acute renal allograft failure on the assumption that poor allograft perfusion should result in a low FENa. However, many patients receive medications which affect the active transport of Na+ and thus FENa. In contrast, the fractional excretion of urea (FEurea) is mostly dependent on passive forces and is therefore less influenced by drug therapy. To test the hypothesis that FEurea might be more useful than FENa in evaluating graft failure, we compared FEurea with FENa during 79 episodes of acute renal allograft dysfunction due to acute rejection (AR), cyclosporine nephrotoxicity (CsA-Nx), viral infection, or bacterial infection in 32 children and young adults with renal transplants. There was no significant difference between groups in FENa. However, FEurea was significantly lower (P < 0.05) in patients with CsA-Nx (32.6 +/- 1.9%) and viral infection (32.9 +/- 3.2%) than those with AR (45.1 +/- 1.7%) or bacterial infection (38.9 +/- 2.5%). FEurea was < 35% in 20 of 28 (71.4%) episodes of CsA-Nx and 8 of 11 (72.2%) of viral infection, but only 5 of 36 (13.9%) of AR (P < 0.05). FEurea was also measured during stable graft function, 7-14 days prior to allograft dysfunction. CsA-Nx was associated with a 30.5 +/- 8.3% decrease in FEurea. FEurea did not change in patients with AR. Based on these findings, we present an algorithm to aid in the differential diagnosis of acute renal allograft failure.

Acute Disease↗
PubMed1993

Role of intracellular phosphate in the regulation of renal phosphate transport during development.

Direct correlations have been observed between the renal intracellular concentration of phosphate ([Pi]i) and postnatal age (3-13 weeks in rats, 1-4 weeks in guinea pigs), as well as between the dietary supply of Pi and [Pi]i. In turn, [Pi]i was found to be inversely correlated with the renal tubular transport of phosphate (TRPi). However, age- and diet-related differences in [Pi]i alone do not explain the high capacity of Na(+)-Pi cotransport present in the kidney of the neonate. Therefore, we explored whether changes in TRPi induced by altering Pi demand (whole body growth or bone mineralization) are mediated by factors other than changes in [Pi]i. TRPi was measured in vivo and nuclear magnetic resonance-visible [Pi]i in perfused kidneys of 8-week-old genetically growth hormone (GH)-deficient and GH-treated dwarf rats and in 8-week-old thyroparathyroidectomized (TPTX) Sprague-Dawley (SD) rats treated or untreated with etidronate (EHDP), an inhibitor of bone mineralization. In dwarf rats, [Pi]i was 1.2 +/- 0.2 mM and TRPi 2.4 +/- 0.2 mumol/ml glomerular filtrate. In TPTX SD rats, [Pi]i was 1.6 +/- 0.2 mM and TRPi 4.2 +/- 0.3 mumol/ml glomerular filtrate. Administration of GH to dwarf rats resulted in increases in Pi transport of 38% +/- 8% (P < 0.05), while administration of EHDP to TPTX SD rats decreased TRPi by 52% +/- 7% (P < 0.05). Neither GH nor EHDP significantly affected [Pi]i. Thus, in the rat changes in TRPi due to alterations in Pi demand occur in the absence of significant changes in [Pi]i.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The significance of pain in children's experiences of hemophilia.

The purpose of this research was to document how children with hemophilia describe their experiences with pain in relation to their understanding of their unique illness and treatment experiences. Subjects were 20 children with hemophilia who were between the age of 6 years and 13 years and had no evidence of cognitive problems. Following the principles of grounded theory, data about children's experiences of hemophilia were obtained through a semi-structured interview using five pictorial stimuli representing illness and treatment domains. Data analysis was conducted using the constant comparative method. Findings indicated that pain experiences had a major role in children's perceptions of their illness and treatment experiences and in the meaning attached to these experiences.

Adolescent↗
PubMed1992

Illness and treatment appraisal processes of healthy and hemophilic boys.

The purposes of this study was to describe patterns characterizing appraisal processes of chronically ill and healthy school-age boys regarding illness and treatment situations. The specific aims were to describe (a) the domains representing the process of appraisal, (b) the relationships among the domains, and (c) the patterns of appraisal based on the interplay among the various domains. The sample included 18 healthy boys and 18 hemophilic boys. The two groups were matched on the basis of child's age and family socioeconomic level. A qualitative methodology was used to understand the ways in which boys appraise illness- and treatment-related stimuli. Findings showed that appraisal processes of school-age boys were comprised of four interacting domains: delineation of the context, fears related to the stimuli, the emotional response to the stimuli, and the final decision. The characteristics of these domains and the relationships among them resulted in two patterns of appraisal: amplification and minimization.

Adaptation, Psychological↗
PubMed1992

The influence of the shape of mechanical stimuli on muscle stretch reflexes and SEP.

Stretching of human thenar muscle was carried out using mechanical stimuli of different amplitudes and velocities in 50 normal subjects. Amplitudes of early M1 and late M2 reflex responses as well as cortical evoked potentials were recorded. M1 and M2 increased with a larger mechanical stimulus. Steeper mechanical stimuli generated larger M1 amplitudes, whereas M2 remained unaffected. Amplitudes of early cortical evoked potentials increased with increase of both rise-time and amplitude of muscle stretch. The shape of the mechanical stimulus is critical for the resulting reflex response. The different behaviours of M1 and M2 with increasing stimulus velocity are in favour of their different origins. Our results support a participation of slowly conducting muscle spindle afferents in the generation of the late M2 response in distal human hand muscles.

Adult↗