The effect of cytochalasin B on effector--target cell interaction. Quantitative and ultrastructural study.

Interaction between pokeweed mitogen-stimulated secondary lymphocytes (PWM-lymphocytes) and target fibroblasts resulted in over 80 per cent adherence of the sensitized lymphocytes to the target cells. Adherence is by pseudopod penetration into target fibroblasts. The only lymphocyte cellular components found in the contact region were microfilaments. Cytochalasin B completely inhibited the specific adsorption of the PWM-secondary lymphocytes to the target cells. What adhesion did take place in the presence of cytochalasin B was found to be nonspecific. Ultrastructurally, the contact between lymphocyte and target cells was altered by the drug, when pseudopods were not observed. Possible effects of cytochalasin B on lymphocyte-mediated cytolysis, mainly by its effect on microfilament function, is discussed.     

Spontaneous migration and adherence of leukocytes and the NBT test of peripheral blood neutrophils in patients with iron deficiency anemia]

Literature reports suggest that iron-deficiency may contribute to the development or intensification of the condition termed generally "immunodeficiency". In the available literature no reports were found on a precise evaluation of the functions of peripheral blood neutrophils in iron deficiency anaemia. The purpose of the presented study was: 1) estimation of the adherence of neutrophils from peripheral blood to fibres, 2) evaluation of the indices of spontaneous and latex-stimulated NBT reduction by the neutrophils, and 3) the test of spontaneous migration of peripheral blood leucocytes. The study of 20 patients with iron-deficiency anaemia, with counts of total leucocytes and absolute neutrophil count in peripheral blood showed increased adherence of the neutrophils and reduced spontaneous migration of leucocytes in the 3-hour test, but no changes in the test of spontaneous and latex-stimulated NBT reduction. In the discussion an interpretation of the observed abnormalities in the studied biological functions of the neutrophils in patients with iron-deficiency anaemia is tentatively put forward, stressing that in this anaemia despite absence of changes in the counts of peripheral blood neutrophils, spontaneous migration of peripheral blood neutrophils in the 3-hour test is reduced, perhaps as a result of increased adherence of neutrophils.     

Recovery from and consequences of severe iatrogenic lymphopenia (induced to treat autoimmune diseases)

To ascertain the consequences of severe leukopenia and the tempo of recovery, we studied the immunity of 56 adult patients treated for multiple sclerosis or systemic sclerosis with autologous CD34 cell transplantation using extremely lymphoablative conditioning. NK cell, monocyte, and neutrophil counts recovered to normal by 1 month; dendritic cell and B cell counts by 6 months; and T cell counts by 2 years posttransplant, although CD4 T cell counts remained borderline low. Initial peripheral expansion was robust for CD8 T cells but only moderate for CD4 T cells. Subsequent thymopoiesis was slow, especially in older patients. Importantly, levels of antibodies, including autoantibodies, did not drop substantially. Infections were frequent during the first 6 months, when all immune cells were deficient, and surprisingly rare (0.21 per patient year) at 7-24 months posttransplant, when only T cells (particularly CD4 T cells) were deficient. In conclusion, peripheral expansion of CD8 but not CD4 T cells is highly efficient. Prolonged CD4 lymphopenia is associated with relatively few infections, possibly due to antibodies produced by persisting pretransplant plasma cells.     

Cytochemical properties of peripheral blood neutrophils in patients with hyperthyroidism]

In the cytoenzymatic investigations of peripheral blood neutrophils in patients with hyperthyroidism there was found the increase of acid phosphatase activity, beta-glucuronidase, leucine aminopeptidase, and catalase moreover there was found the decrease of the activity of alkaline phosphatase. After a two-week treatment with thiamazole (methimazole++) 50 mg in 24-hour dose there was observed the decrease of acid phosphatase activity in neutrophils. During incubation of plasma containing leucocytes, from healthy persons, with L-thyroxine there was observed the increase of the activity for acid phosphatase and beta-glucuronidase. In patients with hyperthyroidism there appear many changes of enzymic equipment of neutrophils which are concerned with lysosomal and connected with cell membrane enzymes. The results of cytochemical investigations after application of thiamazole and no difference, with exception of catalase, between patients with Graves-Basedow disease and with toxic goitre and the results of investigations in vitro with L-thyroxin point out, that there is the possibility of connection between the observed changes in the range of enzymic equipment of neutrophils and the hormonal state of the investigated group of patients.     

Diversity of bat-associated Leptospira in the Peruvian Amazon inferred by bayesian phylogenetic analysis of 16S ribosomal DNA sequences

The role of bats as potential sources of transmission to humans or as maintenance hosts of leptospires is poorly understood. We quantified the prevalence of leptospiral colonization in bats in the Peruvian Amazon in the vicinity of Iquitos, an area of high biologic diversity. Of 589 analyzed bats, culture (3 of 589) and molecular evidence (20 of 589) of leptospiral colonization was found in the kidneys, yielding an overall colonization rate of 3.4%. Infection rates differed with habitat and location, and among different bat species. Bayesian analysis was used to infer phylogenic relationships of leptospiral 16S ribosomal DNA sequences. Tree topologies were consistent with groupings based on DNA-DNA hybridization studies. A diverse group of leptospires was found in peri-Iquitos bat populations including Leptospira interrogans (5 clones), L. kirschneri (1), L. borgpetersenii (4), L. fainei (1), and two previously undescribed leptospiral species (8). Although L. kirschenri and L. interrogans have been previously isolated from bats, this report is the first to describe L. borgpetersenii and L. fainei infection of bats. A wild animal reservoir of L. fainei has not been previously described. The detection in bats of the L. interrogans serovar Icterohemorrhagiae, a leptospire typically maintained by peridomestic rats, suggests a rodent-bat infection cycle. Bats in Iquitos maintain a genetically diverse group of leptospires. These results provide a solid basis for pursuing molecular epidemiologic studies of bat-associated Leptospira, a potentially new epidemiologic reservoir of transmission of leptospirosis to humans.     

Combined analysis of polymorphisms in glutathione S-transferase M1 and microsomal epoxide hydrolase in lung cancer patients

Many genes involved in the metabolism of carcinogens have been found to be polymorphic in the human population, and specific alleles are associated with increased risk of cancer at various sites. The etiology of most commonly occurring cancers cannot be explained by allelic variability at a single locus. A combined analysis of two polymorphic enzymes, glutathione S-transferase M1 (GSTM1), microsomal epoxide hydrolase (EPHX1)) and their implication as lung cancer risk factors was performed in a case- control study of non small cell lung cancer. Polymerase chain reaction (PCR) or PCR-RFLP-based methods were used to detect variant genotypes of GSTM1 and EPHX1 (113Tyr-113His in exon 3 and 139His-139Arg in exon 4) in 150 controls and group of lung cancer patients (n=121). The slow 113His EPHX1 allele tended to be more frequent among the patients (frequency 0.587) than among the controls (0.320) (Fisher s exact test, p=0.33). The combined EPHX1 homozygote genotype His113/His139 (predicted very slow activity) versus all other genotype combination was associated with an increased risk of lung cancer (OR=2.29; 95% C.I.=0.94- 5.82), particularly in non-smokers (OR=11.23; 95% C.I.=1.48- 88.41). Polymorphism in GSTM1 had no statistically significant impact on lung cancer risk alone (OR=1.09; 95% C.I.: 0.65-1.82). However, obtained the results revealed that combinations GSTM1 null with homozygote His113/His139 genotype (predicted very slow activity EPHX1) significantly increased lung cancer risk (OR=3.65; 95% C.I.: 1.04-16.07). No overall relationship between genotype combinations predicted high EPHX1 activity and lung cancer risk was confirmed in all followed respects. However, the number of investigated individuals in our study was relatively small, therefore these findings should be judged with circumspectness.     

beta-Adducin polymorphisms, blood pressure, and sodium excretion in three European populations

The associations of the beta-adducin C1797T polymorphism with blood pressure (BP) and various indexes of sodium homeostasis were investigated in 388 men and 456 women, aged 18 to 60 years, recruited from three European populations (Cracow, Poland, n = 300; Novosibirsk, Russian Federation, n = 274; Mirano, Italy; n = 270). Phenotypes included 24-h ambulatory BP and urinary excretion of electrolytes and aldosterone. Subjects were genotyped for the beta-adducin polymorphism. Both a population-based association study and a family-based analysis were performed. Urinary sodium excretion was higher in Cracow than in Mirano (241 v 185 mmol/24 h, P <.05) and intermediate in Novosibirsk (206 mmol/24 h). The beta-adducin T allele (15.2% v 9.1%, P <.0001) was more prevalent in Mirano than in the two Slavic centers. In both population-based and family-based association analyses, there was significant heterogeneity between Slavic and Italian subjects in the phenotype-genotype relationships with beta-adducin. In the Slavic centers, 24-h systolic BP was higher in T allele carriers than in CC homozygotes (122.3 v 119.7 mm Hg, P =.03), whereas this was not the case in Mirano (121.8 v 122.9 mm Hg, P =.42). In Slavic (212.6 v 233.1 mmol/24 h) as well as in Italian (166.1 v 191.5 mmol/24 h) participants, 24-h sodium excretion was lower (P =.01) in T allele carriers than in CC homozygotes. These results were confirmed in the family-based analysis of offspring using a quantitative transmission disequilibrium test. In conclusion, the frequency of the beta-adducin T allele and salt intake differ across European populations. Thus, both variation in genetic background and salt intake may explain the observed heterogeneity in the phenotype-genotype relationships. Genetic determinants of complex quantitative traits such as BP can only be investigated within their epidemiologic context.