Transient decrease of neutrophil chemotaxis following aerobic exercise

PURPOSE: Intense exercise affects the immune system, increasing the susceptibility of athletes to viral and bacterial infections. We have previously shown a significant decrease of fMLP-neutrophil migration 24 h after aerobic exercise. In this study we aimed to look at the differential effect of different chemoattractants on neutrophil migration following aerobic exercise, to determine the recovery time, and to better understand the role of the cell skeleton behind the impaired chemotaxis. METHODS: Sixteen female volunteers aged 22-30 yr were tested before, 24, and 48 h after aerobic exercise (30 min running at 70% (.)VO(2max). The submaximal exercise test was conducted a week after the (.)VO(2max) test.We studied the membrane cell receptor response to fMLP, IL-8, and C5a, which have specific ligand-receptor pathways. Further, we studied the cytoskeletal response by investigating the cell polarization and the F-actin polymerization. RESULTS: Significant decrease of the neutrophil net chemotaxis was detected with fMLP, IL-8 and C5a, 24 h after exercise (50 +/- 5%, P = 0.0001; 48 +/- 12%, P = 0.0015; and 32 +/- 11%, P = 0.011, respectively). Complete recovery was observed within 48 h with all chemoattractants. Normal neutrophil random migration and F-actin polymerization were found. Decreased neutrophil polarization was detected (46 +/- 6% vs 22 +/- 8% of polarized cells, before and after effort, respectively; P = 0.004). Correlation between polarization and chemotactic migration was found (r = 0.945; P = 0.001). CONCLUSIONS: The impaired chemotactic response, observed 24 h after exercise, was similar using different chemoattractants. This finding indicates a possible exercise-induced effect on a common factor at the ligand-receptor level. The abnormal cell polarization indicates skeletal dysfunction that should be further investigated and elucidated. The normal fMLP-stimulated-F-actin polymerization reflects an adequate pathway of signal transduction for the formyl peptide.     

Diurnal fluctuation of leukocyte G6PD activity. A possible explanation for the normal neutrophil bactericidal activity and the low incidence of pyogenic infections in patients with severe G6PD deficiency in Israel

Acute hemolytic anemia associated with red blood cell (RBC) glucose-6-phosphate dehydrogenase (G6PD) deficiency is commonly encountered in the Mediterranean basin. Nevertheless, concomitant clinical evidence of white blood cell G6PD deficiency is extremely rare in Israel. This study sought to assess simultaneously levels of G6PD activity in polymorphonuclear leukocytes (PMN) and in red blood cells (RBC) of patients with G6PD deficiency, including full-term newborn infants. In PMN, the correlation between G6PD activity, hexose monophosphate shunt activity, and superoxide anion release was evaluated. In G6PD-deficient patients, a parallel and significantly decreased G6PD activity was found in neutrophils (range of activity 0-4.5 IU/10(6) PMN) and erythrocytes (range of activity 0-1.8 IU/g Hb), compared with healthy controls (5-23 IU/10(6) PMN and 2.4-6.4 IU/g Hb, respectively). A positive correlation was found in PMN between the levels of G6PD activity, hexose monophosphate (HMP) shunt activity, and superoxide anion release (p < 0.01). Nevertheless, all patients' bactericidal activity of neutrophils remained in the range of healthy controls. Although many episodes of acute hemolytic anemia were recorded, no increased incidence of pyogenic infections was observed in any group of patients investigated. Neutrophil and erythrocyte G6PD levels were re-assessed in some of these patients several times a day. A significant diurnal fluctuation of the enzyme activity was found. It is speculated that the patients produce fluctuating daily quantities of NADPH, sufficient to initiate the neutrophil respiratory burst and to achieve normal bactericidal activity, necessary to prevent the development of microbial infections.     

Survival of frozen-thawed human ovarian fetal follicles in long-term organ culture

Ovarian follicles obtained from second and third-trimester human fetuses survived 4 weeks in organ culture and secreted 17-beta estradiol (E(2)).     

Outcome of IgM- and IgG-seropositive cases of varicella zoster in pregnancy

OBJECTIVE: To study the outcome of IgG- and IgM-seropositive cases of varicella zoster virus (VZV) in pregnancy. STUDY DESIGN: The VZV immune status of 120 pregnant women who had been exposed to VZV and did not recall a history of VZV infection was determined, and 109 were VZV immune. Eleven women were both IgG and IgM seropositive, and the outcomes of their pregnancies were studied. RESULTS: Nine of the 11 VZV IgM-, IgG-seropositive pregnant women were asymptomatic, without fetal damage. CONCLUSION: The majority of the women were asymptomatic, but no statement about the relative risk of being affected by the virus can be made.     

Young infants' morbidity and exposure to fine particles in a region with two power plants

This study investigated the effect of fine particulate matter (PM2.5) in ambient air on hospital admissions and emergency room (ER) visits among young children (0-3 yr) residing in 4 communities in southern Israel, within an area 5-25 km from the 2 power plants, which operate within 25 km of each other. Daily records of hospitalizations and ER visits for respiratory diseases at the 3 hospitals serving the region were examined for 9 mo, October 1, 2000-June 30, 2001. Mean PM2.5 concentrations for the four communities ranged from 11.6 to 28.1 microg/m3. Time series analysis revealed a statistically significant association (p < 0.05) between the numbers of hospitalizations and ER visits for respiratory symptoms and concentrations of PM2.5. This effect was evaluated for 0-3 lag days, directly, and for interactions with temperatures and seasonal parameters. The respiratory health of young children may be affected by 24 hr concentrations of PM2.5 < 60 microg/m3, the threshold proposed by both Israel and the United States.     

Switching elderly chronic psychotic patients to olanzapine

The purpose of this study was to examine whether elderly chronic schizophrenia or schizoaffective disorder patients would clinically improve if switched to olanzapine from previous neuroleptic treatment. Twenty-one hospitalized patients, aged 6088 yr, with a diagnosis of chronic schizophrenia or schizoaffective disorder who were being treated with typical neuroleptic medication were switched to olanzapine. The Positive and Negative Symptom Scale (PANSS), Geriatric Depression Scale (GDS) and Clinical Global Impression Severity (CGI-S) Scale were completed while patients were on their previous medication regimen and again 6 months after the last patient had been started on olanzapine. The mean duration of treatment was 289 d (S.D.=139). Three patients discontinued the medication. Mean end dose of olanzapine was 12.9 mg (S.D.=5.7). Paired sample t tests were used to test change on PANSS Positive, Negative and Total scales, CGI, GDS and body weight. PANSS (Positive, p=0.002; Negative, p=0.003; General, p=0.003; and Total, p=0.000) and CGI (p=0.000) but not the GDS (p=0.67) demonstrated statistically significant improvement. There was no significant change in body weight (p=0.61). Elderly patients with aggravation of chronic schizophrenia showed improvement after being switched to olanzapine with no weight gain. Clinically meaningful change was observed in positive and negative psychotic symptomatology but not in depressive symptoms.     

Endothelin receptor B inhibition triggers apoptosis and enhances angiogenesis in melanomas

Endothelin receptor B (ETRB or EDNRB) is overexpressed in most human melanomas and is proposed to provide a marker of melanoma progression. We have shown previously that inhibition of ETRB leads to increased human melanoma cell death in vitro and in vivo, resulting in shrinkage of tumors grown in immunocompromised mice. In the present work, we analyzed the effects of ETRB inhibition on 10 human melanoma cell lines derived from tumors at distinct stages of progression. Our observations suggest that the ETRB antagonist BQ788 induces apoptosis most effectively in metastatic melanoma cells. Microarray analysis shows that BQ788 treatment leads to a reduction in the expression of the survival factor BCL-2A1 and the DNA repair factor poly(ADP-ribose) polymerase 3 that is more pronounced in cells derived from metastatic than primary melanoma. Decreased cell viability was observed to correlate with reduction in ETRB expression, and reduction in ETRB protein levels by small interfering RNA led to an increase in cell death. Interestingly, reduction of ETRB expression by BQ788 was accompanied by a strong induction of VEGF expression and repression of the angiogenic suppressor gravin. These changes in gene expression correlated with increased angiogenesis in tumors injected with ETRB antagonist in vivo. Taken together, our observations suggest that ETRB may provide a potential therapeutic target in high-grade melanomas and identify candidate pathways that may be implicated in the regulation of cell survival and tumor progression associated with ETRB signaling.     

Mitochondrial pro-apoptotic ARTS protein is lost in the majority of acute lymphoblastic leukemia patients

Acquired resistance towards apoptosis is the hallmark of most if not all types of cancer. We have previously identified and characterized ARTS, a broadly expressed protein localized to mitochondria. ARTS was initially shown to mediate TGF-beta induced apoptosis. Recently, we have found that high levels of ARTS induce apoptosis without additional pro-apoptotic stimuli. Further, ARTS promotes apoptosis in response to a wide variety of pro-apoptotic stimuli. Here, we report that the expression of ARTS is lost in all lymphoblasts of more than 70% of childhood acute lymphoblastic leukemia (ALL) patients. The loss of ARTS is specific, as the related non-apoptotic protein H5, bearing 83% identity to ARTS, is unaffected. During remission, ARTS expression is detected again in almost all patients. Two leukemic cell lines, ALL-1 and HL-60 lacking ARTS, were resistant to apoptotic induction by ara-C. Transfection of ARTS into these cells restored their ability to undergo apoptosis in response to this chemotherapeutic agent. We found that methylation process contributes to the loss of ARTS expression. We conclude that the loss of ARTS may provide a selective advantage for cells to escape apoptosis thereby contributing to their transformation to malignant lymphoblasts. We therefore propose that ARTS can function as a tumor suppressor protein in childhood ALL.