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Biomedical subjects

Y Weinstein

Publications and source records attributed to Y Weinstein.

At least 19 recordsLinked to original sources
PubMed2000

Anaerobic power and muscle strength in young hemophilia patients.

PURPOSE: The purpose of this study was to evaluate muscle strength and anaerobic power in young boys with hemophilia compared with healthy boys. METHODS: Thirteen boys with severe hemophilia (H) (mean (+/- SD) age = 12.0 +/- 3.17 yr) and 16 control (C) boys (age = 11.9 +/- 2.8 yr) performed elbow and knee flexion and extension on the Biodex System II dynamometer at two angular velocities. They also performed a Wingate Anaerobic Test (WAnT) for the legs and for the arms. All H subjects received prophylactic factor VIII treatment in the 24 h pretesting, and no test was performed in the presence of hemorrhage. RESULTS: C were consistently stronger than H in all dynamic strength measures (e.g., elbow flexors: 0.47 +/- 0.15 vs 0.36 +/- 0.08 N x m x kg(-1) for C and H, respectively, P < 0.05). Anaerobic mean power was also higher in C compared with H in both upper and lower extremities (arms: 3.08 +/- 0.99 vs 2.22 +/- 0.46 W x kg(-1) for C and H, respectively; legs: 6.94 +/- 1.62 vs 5.54 +/- 1.03 W x kg(-1) for C and H, respectively, P < 0.05). Upper and lower extremity strength, as well as anaerobic power, increased with age in C but not in H. By using the Godin Leisure-Time Exercise Questionnaire, H were found to be much less active, especially in intense activities, compared with C. CONCLUSION: Children and adolescents with hemophilia are characterized by lower muscle strength and anaerobic power compared with age-matched controls. This may be related to their lower leisure-time activity.

Adolescent↗
PubMed2000

Specific inspiratory muscle training in well-trained endurance athletes.

PURPOSE: It has been reported that arterial O2 desaturation occurs during maximal aerobic exercise in elite endurance athletes and that it might be associated with respiratory muscle fatigue and relative hypoventilation. We hypothesized that specific inspiratory muscle training (SIMT) will result in improvement in respiratory muscle function and thereupon in aerobic capacity in well-trained endurance athletes. METHODS: Twenty well-trained endurance athletes volunteered to the study and were randomized into two groups: 10 athletes comprised the training group and received SIMT, and 10 athletes were assigned to a control group and received sham training. Inspiratory training was performed using a threshold inspiratory muscle trainer, for 0.5 h x d(-1) six times a week for 10 wk. Subjects in the control group received sham training with the same device, but with no resistance. RESULTS: Inspiratory muscle strength (PImax) increased significantly from 142.2 +/- 24.8 to 177.2 +/- 32.9 cm H2O (P < 0.005) in the training but remained unchanged in the control group. Inspiratory muscle endurance (PmPeak) also increased significantly, from 121.6 +/- 13.7 to 154.4 +/- 22.1 cm H2O (P < 0.005), in the training group, but not in the control group. The improvement in the inspiratory muscle performance in the training group was not associated with improvement in peak VEmax, VO2max breathing reserve (BR). or arterial O2 saturation (%SaO2), measured during or at the peak of the exercise test. CONCLUSIONS: It may be concluded that 10 wk of SIMT can increase the inspiratory muscle performance in well-trained athletes. However, this increase was not associated with improvement in aerobic capacity, as determined by VO2max, or in arterial O2 desaturation during maximal graded exercise challenge. The significance of such results is uncertain and further studies are needed to elucidate the role of respiratory muscle training in the improvement of aerobic-type exercise capacity.

Adolescent↗
PubMed2000

Impairment in quality of life among patients seeking surgery for hyperhidrosis (excessive sweating): preliminary results.

BACKGROUND: The present paper describes the initial stages of the development and administration of a short, disease-specific, health related questionnaire to assess the impact of suffering from hyperhidrosis (excessive sweating) on the Quality of Life (QoL) of patients who are anticipating surgery for this disorder. METHOD: The study was performed in two stages: 1. The life domains in which the condition impairs QoL were assessed by in-depth interviews with 10 patients suffering from hyperhidrosis. 2. A questionnaire covering five life domains was built based on these interviews. 3. This questionnaire was administered to 48 patients, 30 females and 18 males between the ages 15 and 48. RESULTS: Results showed that subjective QoL was significantly lower among females in four of the five life areas and that duration of the condition correlates with a lower quality of life. A regression analysis showed that the subjective suffering of the patients was explained mainly by social aspects. CONCLUSIONS: The questionnaire is a novel attempt to assess QoL in a disorder with strong esthetic and social consequences and could improve communication between patients and their physicians.

Adult↗
PubMed1999

Antitumor and immunotherapeutic effects of activated invasive T lymphoma cells that display short-term interleukin 1alpha expression.

Expression of cytokines in malignant cells represents a novel approach for therapeutic treatment of tumors. Previously, we demonstrated the immunostimulatory effectiveness of interleukin 1alpha (IL-1alpha) gene transfer in experimental fibrosarcoma tumors. Here, we report the antitumor and immunotherapeutic effects of short-term expression of IL-1alpha by malignant T lymphoma cells. Activation in culture of T lymphoma cells with lipopolysaccharide-stimulated macrophages induces the expression of IL-1alpha. The short-term expression of IL-1alpha persists in the malignant T cells for a few days (approximately 3-6 days) after termination of the in vitro activation procedure and, thus, has the potential to stimulate antitumor immune responses in vivo. As an experimental tumor model, we used the RO1 invasive T lymphoma cell line. Upon i.v. inoculation, these cells invade the vertebral column and compress the spinal cord, resulting in hind leg paralysis and death of the mice. Activated RO1 cells, induced to express IL-1alpha in a short-term manner, manifested reduced tumorigenicity: approximately 75% of the mice injected with activated RO1 cells remained tumor free. IL-1 was shown to be essential for the eradication of activated T lymphoma cells because injection of activated RO1 cells together with IL-1-specific inhibitors, i.e., the IL-1 receptor antagonist or the M 20 IL-1 inhibitor, reversed reduced tumorigenicity patterns and led to progressive tumor growth and death of the mice. Furthermore, activated RO1 cells could serve as a treatment by intervening in the growth of violent RO1 cells after tumor take. Thus, when activated RO1 cells were injected 6 or 9 days after the inoculation of violent cells, mortality was significantly reduced. IL-1alpha, in its unique membrane-associated form, in addition to its cytosolic and secreted forms, may represent a focused adjuvant for potentiating antitumor immune responses at low levels of expression, below those that are toxic to the host. Further assessment of the immunotherapeutic potential of short-term expression of IL-1alpha in activated tumor cells may allow its improved application in the treatment of malignancies.

Animals↗
PubMed1998

The ftsZ gene as a tool for detection of Mycoplasma fermentans.

Mycoplasma fermentans was reported as a common contaminant of cell cultures, and was shown to either induce or suppress several immunological functions. A strain of M. fermentans was recently isolated from a mouse T-lymphoma cell line, which differs from other M. fermentans strains by its growth characteristics and was designated (in the authors' records) as strain 609. Using the differential display technique (DD), a differentially expressed gene that was identified as the M. fermentans 609 ftsZ gene was isolated. Comparison of the nucleotide sequence of the M. fermentans 609 ftsZ gene to other ftsZ genes showed a 98% homology with Mycoplasma fermentans strain K7 and approximately 50% homology with Mycoplasma pulmonis and Mycoplasma genitalium. Comparison of the putative amino acid sequences of the FtsZ proteins showed similar homology. A polymerase chain reaction (PCR) assay to detect the presence of this ftsZ gene was established; it is a fast and convenient assay to detect infection of cells by the M. fermentans species. This work demonstrates that: (i) DD can be used as a useful technique to identify and isolate mycoplasmal genes from infected cells; and (ii) the ftsZ gene can be a useful marker to distinguish between different species of mycoplasma.

Amino Acid Sequence↗
PubMed1998

The effect of heat exposure on performance of and recovery from high-intensity, intermittent exercise.

Environmental heat is known to hamper aerobic performance. The purpose of this study was to examine the effect of heat on the performance of anaerobic exercise and the recovery from such exercise. Eleven trained men underwent two identical exercise-recovery protocols in neutral (22 degrees C, N) and hot (35 degrees C, H) conditions, in a cross-balanced order. Exercise consisted of a series of five 15 s bouts separated by 30 s of active recovery between bouts. The 60 min resting recovery was evaluated with a subsequent exercise series. Subjects were kept euhydrated with water. Peak power developed in the initial exercise series was higher in H compared with N (720 +/- 80 vs 664 +/- 74 W, respectively, p < 0.05). In the second series of exercise, peak power slightly improved in N but decreased in H (6.1 vs -4.1 %, respectively). Mean power was higher in the initial exercise series in H compared with N (636 +/- 83 vs 584 +/- 60 W, respectively, p < 0.05). No significant change occurred in the subsequent series of exercise. There was no difference in peak lactate following the initial series, nor in the decrease of lactate during recovery between the two conditions. Likewise, there were no differences in the changes in electrolyte concentrations and serum osmolality during recovery. VO2 and heart rate decreased following exercise in a similar manner in the two conditions. Rectal temperature increased similarly but remained elevated during H compared with N (p<0.05). In conclusion, the results of this study suggest that heat exposure may improve anaerobic performance but does not appear to affect the physiological responses during 60 min of recovery. Future research should examine the effect of more extreme heat stress, as well as shorter recovery periods.

Adult↗
PubMed1998

Reliability of peak-lactate, heart rate, and plasma volume following the Wingate test.

PURPOSE: The 30-s Wingate Anaerobic Test (WAnT) has been used to assess anaerobic performance capacity and to evaluate physiological responses to supramaximal exercise. Blood lactate concentration ([La]) following supramaximal exercise is often used in the field and in the laboratory to assess the glycolytic contribution to exercise. Although the reliability of the performance in the WAnT has been established, this has not been the case with the WAnT's [La] response. Thus, the main purpose of this research was to study the test-retest reliability of peak [La] following the WAnT. Additionally, the test-retest reliability of the heart rate (HR) and plasma volume changes (deltaPV) response was also evaluated. METHODS: Twenty-nine subjects (15 male, 14 female) of diverse training levels as well as physical characteristics (mean +/- SD: 23.3+/-7.0 yr, 62.5+/-12.0 kg, 170.8+/-9.7 cm, and 16.3+/-6.2% fat) performed two WAnTs within 1 wk. Capillary blood was sampled from a prewarmed fingertip at rest, just before the WAnT and at 3, 5, 7, and 9 min following it. HR was also measured during these times. RESULTS: Mean-power (MP) (+/-SE) in test 1 and test 2 was 8.4+/-0.2 and 8.3+/-0.2 W X kg(-1) body mass, respectively. Peak [La] was attained 5-7 min following the WAnTs and was not significantly different between test 1 and test 2 (9.7+/-0.3 vs 9.8+/-0.3 mM, respectively). Peak HR occurred within 5 s post-WAnT and was not different between tests (170.8+/-2.2 and 171.3+/-2.2 beats X min(-1), in test 1 and test 2, respectively). Peak deltaPV was not different between tests (-12.0+/-3.4 and -11.1+/-3.2%, in test 1 and test 2, respectively). The intraclass reliability coefficients for peak [La]. peak HR and deltaPV were 0.926, 0.941, and 0.878, respectively, whereas the corresponding value for MP was 0.982. CONCLUSIONS: We conclude that peak [La], peak HR, and deltaPV following the WAnT are reliable measures.

Adult↗
PubMed1997

The effect of environmental temperature on testosterone and cortisol responses to high intensity, intermittent exercise in humans.

The purpose of this study was to examine the testosterone, cortisol, and the molar ratio of testosterone to cortisol (T:C) blood concentration responses to intermittent, high intensity exercise in the heat. Eight active men [mean age 25 (SD 3) years, mass 71.1 (SD 5.5) kg, height 175.9 (SD 4.4) cm] performed two series of five 15-s Wingate anaerobic power tests in both hot (H, 35 degrees C) and thermoneutral (TN, 22 degrees C) environments. Each period of exercise was separated by 30-s of active recovery. Each series was separated by 60 min of passive recovery. Blood samples were obtained before (PRE), immediately post (IP), and 5(5R), 10(10R), 15(15R), 30(30R), 45(45R), and 60(60R) min following exercise. Peak power was significantly higher, during the first series of exercise, in the H compared to TN. No significant differences were seen in any of the variables between the first and second series of exercise in either environmental condition. Furthermore, no significant differences between these conditions were observed in heart rate, blood lactic acid concentration, or rectal temperature. A significant decrease in cortisol concentration was observed between PRE and IP, during both conditions. However, no significant interactions between TN or H were seen. No change from PRE was observed in testosterone or T:C during either TN or H. It would appear that testosterone and cortisol respond similarly to repeated periods of short duration high intensity exercise, in either thermoneutral or moderately hot environments.

Adult↗
PubMed1997

Identification of genes induced by interleukin-3 and erythropoietin via the Jak-Stat5 pathway using enhanced differential display-reverse southern.

Cytokines mediate their effects on growth and maturation of hematopoietic cells by binding to their cognate receptors and activating target genes. Interleukin-3 (IL-3) and erythropoietin (Epo) induce signal transduction via the Jak-Stat pathway. We report here on the identification of several known and novel genes induced by IL-3 and Epo, using a modified version of the PCR-based technique, enhanced differential display (EDD). We modified the technique to facilitate the screening and verification of the differential expression of the genes by using reverse Southern blotting (RS) and PCR-Southern blotting, and we called it EDD-RS. From the initial 110 genetags that were identified as differential expressed genes, 14 contained more than one gene. Among the differentially expressed genes, 24 are known genes and 39 are novel genes. Several of the known genes, such as IRF-1 and P21waf, were previously observed by others to be induced by IL-3 and Epo, but their dependence on Stat5 activation in cytokine-dependent cells was unknown. Other known genes, such as crp and Mssp2/1, were not described previously as target genes for cytokine induction. The results demonstrate that EDD-RS is an efficient method to identify cytokine-induced genes and can be productive in delineating the signal required for their induction.

Blotting, Southern↗
PubMed1996

Tyrosine phosphorylation of measles virus P-phosphoprotein in persistently infected neuroblastoma cells.

Replication and encapsidation of measles virus (MV) requires the interaction between the nuclear protein (N) and the phosphoprotein (P). It is known that both proteins are phosphorylated on serine and threonine residues. Recently we have shown that N is phosphorylated on tyrosine in persistently-infected mouse neuroblastoma cells (NS20Y/MS). Here, we show that P in NS20Y/MS is also phosphorylated on tyrosine. To investigate whether cellular tyrosine kinases can bind and phosphorylate P, a solid phase kinase assay was employed. We show that bacterially-expressed MV P fragments, were phosphorylated on tyrosine by purified mouse c-Src protein-tyrosine kinase and when mixed with uninfected neuroblastoma cell (NS20Y) extracts, these P fragments were phosphorylated on tyrosine in addition to serine and threonine. These results imply that MV P is a substrate for tyrosine phosphorylation by cellular tyrosine kinase(s).

Animals↗
PubMed1996

A treadmill test of sprint running.

Anaerobic power is characterized by a high degree of specificity regarding both the recruited muscles as well as the recruitment pattern. The popular Wingate Anaerobic Test (WAnT) is a cycling test that does not satisfy the need for a running-specific anaerobic test. We describe such a test, using a novel type of a commercially available treadmill (BRL 1800, Gymrol, France). The ergometer is equipped with a torque motor to neutralize the frictional resistance of the treadmill belt, and a hip-belt harness connected to a horizontal rod. Force applied to the harness is monitored by a strain gauge mounted on the rod, while vertical movement is monitored by a potentiometer at the posterior fixed end of the rod. These, in conjunction with the treadmill belt speed, enable the computation of horizontal and vertical power as well as the combined total output. Power is calculated both as 'peak' power (highest 2.5 s segment) and 'mean' power (20 s duration). Preliminary results of young athletes were generally consistent with the expected age-related changes in anaerobic power. Values obtained on the anaerobic treadmill were always higher than the corresponding WAnT values previously obtained in comparable age groups. The higher values were probably due to the larger muscle mass involved and the shorter peak and mean power durations (2.5 and 20 s versus 5 and 30 s in the WAnT, respectively). This test should enable not only running-specific anaerobic power monitoring but also the characterization of the relationship between the horizontal and vertical components of that power.

Adolescent↗
PubMed1996

Erythropoietin induces activation of Stat5 through association with specific tyrosines on the receptor that are not required for a mitogenic response.

The cytoplasmic domain of the erythropoietin receptor (EpoR) contains a membrane-distal region that is dispensable for mitogenesis but is required for the recruitment and tyrosine phosphorylation of a variety of signaling proteins. The membrane-proximal region of 96 amino acids is necessary and sufficient for mitogenesis as well as Jak2 activation, induction of c-fos, c-myc, cis, the T-cell receptor gamma locus (TCR-gamma), and c-pim-1. The studies presented here demonstrate that this region is also necessary and sufficient for the activation of Stat5A and Stat5B. The membrane-proximal domain contains a single tyrosine, Y-343, which when mutated eliminates the ability of the receptor to couple Epo binding to the activation of Stat5. Furthermore, peptide competitions demonstrate that this site, when phosphorylated, can disrupt Stat5 DNA binding activity, consistent with a role of Y-343 as a site of recruitment to the receptor. Cells expressing the truncated, Y343F mutant (a mutant with a Y-to-F alteration at position 343) proliferate in response to Epo in a manner comparable to that of the controls. However, in these cells, Epo stimulation does not induce the appearance of transcripts for cis, TCR-gamma, or c-fos, suggesting a role for Stat5 in their regulation.

Amino Acid Sequence↗
PubMed1995

Structural and functional analysis of the promoter of the murine V gamma 1.1 T cell receptor gene.

The expression of the germ-line gene V gamma 1.1-C gamma 4 of the T cell receptor (TcR) gamma chain depends on interleukin (IL)-3 induction in hematopoietic cells, while in T cells, the rearranged gene is expressed constitutively. To understand the mechanism that controls TcR gamma gene expression, we cloned and characterized the structure and function of the V gamma 1.1-C gamma 4 TcR promoter. IL-3-dependent cell lines and T cell lines utilized the same transcriptional start sites. In chloramphenicol acetyltransferase (CAT) assays, the minimal 70-bp promoter confers strong transcriptional activity which is 50-60% of the Moloney long terminal repeat promoter activity. The 500-bp promoter region linked to the CAT gene exhibits IL-3 dependency similar to the endogenous TcR gamma gene. The immediate 3' and 5' flanking sequences inhibit the promoter activity two- to fourfold. The promoter lacks an obvious TATA box or CAAT box sequences, but contains a GC box in the untranslated region 3' to the promoter. The GC box is the core sequence of the element which binds Sp1-like proteins. Cloning of this Sp1 binding element in front of the thymidine kinase (TK) promoter and mutations generated in this site demonstrate its function as a silencer. Ultraviolet cross-linking analysis with the Sp1 binding site from the TcR gamma promoter revealed binding of a 90-100-kDa protein in a T cell line (EL-4) and 40-50 and 90-100-kDa proteins in FDC-P1 cells. The possible function of the Sp1-like protein in silencing the minimal promoter activity is discussed.

3T3 Cells↗
PubMed1995

Regulation of mental states and biofeedback techniques: effects on breathing pattern.

The purpose of the present study was to examine whether breathing pattern may be used as a reliable index for the effectiveness of techniques applied for the regulation of mental states. Heart rate (HR), breathing pattern, galvanic skin response (GSR), and electromyogram (EMG) of the frontalis muscle were measured in 39 male and female subjects aged 18-25 years during 10-minute treatment with relaxation technique (autogenic training and/or music) followed by 10 minutes of imagery training. In the first 7 sessions biofeedback (BFB) was not included, while during the last 6 sessions BFB was introduced and utilized by the subjects. Relaxation (music or autogenic training) led to a decrease in breathing frequency, attributed to lengthening of expiration time, as well as reduced HR, GSR, and frontalis EMG response. In most instances imagery training was related to an increase in these indices. Specifically, significant tachypnea was observed during imagery of sprint running. In most cases BFB substantially augmented the physiological responses. In conclusion, our data suggest that, compared with HR, GSR, and EMG responses, the breathing pattern is at least as sensitive to the mental techniques employed, and may be useful as a psychophysiological index for diagnosis and testing, especially in sport practice.

Adult↗
PubMed1995

Blood lactate concentration following exercise: effects of heat exposure and of active recovery in heat-acclimatized subjects.

The purpose of this study was to examine the effect of ambient heat on the decrease in blood lactate concentration ([LA]bl) during passive and during active recovery. Ten trained men performed six 1-min bouts of exercise at 100% VO2peak on a cycle ergometer, with 1-min rest between the bouts. Each subject exercised twice in thermoneutral (22 degrees C, 40% RH, TN), and twice in hot (35 degrees C, 30% RH, H) conditions. Exercise was followed by either 40 min of passive recovery (sitting) or by 20 min active recovery (cycling at 35% VO2peak) and 20 min passive recovery, named thereafter, 'active recovery'. Capillary blood lactate was measured before, 1 min after, and every 5 min during recovery. Heart rate (HR), rectal and skin temperatures (Tre, Tsk) were monitored continuously. VO2 was measured prior to exercise, during the last exercise bout, the first 10 min of recovery, and periodically thereafter. Post-exercise [LA]bl was similar in all treatments (13.5 +/- 1.8, 13.0 +/- 1.3, 14.8 +/- 4.1, 13.3 +/- 2.6 mmol.l-1 for TN-active, TN-passive, H-active and H-passive, respectively). [LA]bl was significantly lower during active, compared to passive recovery in both, TN and H conditions. Environmental heart did not independently affect [LA]bl during passive or active recovery. Exercise resulted in an elevation in Tre in all treatments, with a significantly higher Tre during active recovery in H compared to the other sessions. Likewise, no differences in HR and in VO2 were observed between H and TN conditions during active nor during passive recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1995

Tyrosine phosphorylation of measles virus nucleocapsid protein in persistently infected neuroblastoma cells.

Subacute sclerosing panencephalitis is a slowly progressing fatal human disease of the central nervous system which is a delayed sequel of measles virus (MV) infection. A typical pathological feature of this disease is the presence of viral ribonucleocapsid structures in the form of inclusion bodies and the absence of infectious virus or budding viral particles. The mechanisms governing the establishment and maintenance of a persistent MV infection in brain cells are still largely unknown. To understand the mechanisms underlying MV persistence in neuronal cells, a tissue culture model was studied. Clone NS20Y/MS of the murine neuroblastoma C1300 persistently infected with the wild-type Edmonston strain of MV secretes relatively high levels of alpha/beta interferon (IFN). As shown previously, treatment of the persistently infected cultures with anti-IFN serum converted the persistent state into a productive infection indicated by the appearance of multinucleated giant cells. In this study, we have investigated whether alpha/beta IFN produced by NS20Y/MS cells activates cellular protein tyrosine kinases which will induce tyrosine phosphorylating activity specific to virus-infected cells. We present data to show augmented protein tyrosine kinase activity in the persistently infected cells. We demonstrate that the MV N protein is phosphorylated on tyrosine in addition to serine and threonine in the persistent state but not in NS20Y cells acutely infected with MV.

2',5'-Oligoadenylate Synthetase↗