The partial characterization of alcohol dehydrogenase null alleles from natural populations ofDrosophila melanogaster

Twenty-three alcohol dehydrogenase (ADH) putative null alleles extracted from four Tasmanian (Australia) populations of Drosophila melanogaster produce no ADH activity and are unable to form active heterodimers with either AdhF or AdhS. Twelve of these nulls were tested by enzyme-linked immunosorbent assay (ELISA) and did not produce any ADH cross-reacting material (CRM). The null homozygotes had similar, but slightly lower, mortalities on ethanol-supplemented media compared to an artificially induced null allele. Heterozygotes between the null alleles and standard AdhF and AdhS alleles had intermediate ADH activity and CRM levels.     

Microcin-E492-insensitive mutants of Escherichia coli K12

Mutations in three Escherichia coli K12 genes, tonB, exbB and the newly discovered semA, reduce sensitivity to the low Mr polypeptide antibiotic microcin E492. The products of the tonB and exbB genes were previously shown to be involved in the uptake of siderophore-complexed iron and in the action of a number of colicins. Strains mutated at or close to semA (collectively referred to as sem mutations) remained fully sensitive to these colicins, and grew as well as wild-type strains under conditions of iron starvation. Expression of a number of sem-lacZ operon fusions was not affected by iron limitation, and sem mutations did not affect the production of iron-regulated outer membrane proteins which are known or thought to be involved in iron uptake. Hfr conjugation and P1 phage transduction experiments indicated that semA is located close to pabB at 40 min on the E. coli K12 chromosome. This places semA close to the mng locus, wherein mutations result in decreased manganese sensitivity. However, strains carrying the semA mutation exhibited increased manganese sensitivity.     

Glycogen and trehalose accumulation during colony development in Streptomyces antibioticus

Streptomyces antibioticus accumulated glycogen and trehalose in a characteristic way during growth on solid medium. Glycogen storage in the substrate mycelium took place during development of the aerial mycelium. The concentration of nitrogen source in the culture medium influenced the time at which accumulation started as well as the maximum levels of polysaccharide stored. Degradation of these glycogen reserves was observed near the beginning of sporulation. The onset of sporogenesis was always accompanied by a new accumulation of glycogen in sporulating hyphae. During spore maturation the accumulated polysaccharide was degraded. No glycogen was observed in aerial non-sporulating hyphae or in mature spores. Trehalose was detected during all phases of colony development. A preferential accumulation was found in aerial hyphae and spores, where it reached levels up to 12% of the cell dry weight. The possible roles of both carbohydrates in the developmental cycle of Streptomyces are discussed.     

The hair of the common hare (Lepus europaeus Pall.) and of the common vole (Microtus arvalis Pall.) as indicator of the environmental pollution

We made the INAA of hair of the common hare (Lepus europaeus Pall.) and of the common vole (Microtus arvalis Pall.) living in the emission zones. Both the hare and the vole are almost exclusively herbivores; they consume relatively large amounts of contaminated food and mirror reliably the contamination degree of the respective ecosystem. The use of free-living animals for the control of the environmental quality may complete effectively the information obtained by examination of habitants. Though the free-living animals lead a rather different way of existence it has been found that the analyses of their hair correlate very well with the analyses of human hair. It may be expected that the changes of concentrations of heavy metals will manifest themselves earlier in animals than in men, because the animals are strictly tied to the local food sources. The hair samples of hares contained increased concentrations of Sm, La, Au, As, Se, Cr, Sc, Fe, Ce, Th and Co. The hair of voles showed increased concentrations of Sm, La, Zn, As, Se, Cr, Sc, Fe, Sb, Ce, Cs and Co. A conspicuous trend towards the cumulation in hair was observed in the following elements: As, Se, Sc and Fe. The increase of their concentrations in the hair of animals from the emission regions amounted as such as to 10(3)%.     

Metabolic comparison between basophils and other leukocytes from human blood

Basophilic granulocytes were purified from the blood of normal individuals by successive isopyknic centrifugation and elutriation centrifugation. Starting with the leukocyte-rich fraction of 500 ml of blood, we recovered 31 to 80% (mean 51%, n = 20) of the basophils in 45 to 87% purity (mean 69%, n = 23). The contaminating cells were mainly lymphocytes. The basophils were greater than 98% vital (exclusion of ethidium bromide and hydrolysis of fluorescein diacetate). The histamine content of the basophils was 1.1 to 2 pg/cell (mean 1.6 pg/cell, n = 22). With anti-IgE, 30 to 50% of the histamine was released; with phorbol myristic acetate (PMA) or the calcium ionophore A23187, 70 to 100% of the histamine was released. Serum-opsonized zymosan (STZ) did not induce histamine release. Reactions with monoclonal antibodies revealed that the basophils expressed the C3bi receptor (CR3) and the leukocyte function-associated antigen 1 (LFA1), but not the gp 150,95 antigen, the C3b receptor (CR1), or the low avidity Fc gamma receptor. Basophils carry class I but not class II HLA antigens. During incubation of the basophils with serum-opsonized Staphylococcus aureus or Escherichia coli, these bacteria were neither phagocytized nor killed. STZ, PMA, A23187, or anti-IgE did not initiate an "oxidative burst" in the basophils. This was tested with oxygen consumption, cytochrome c reduction, NBT reduction, chemiluminescence, and release of hydrogen peroxide. Moreover, we did not detect cytochrome b558, superoxide dismutase, catalase, or peroxidase in the basophils. Of the typical granule-associated enzymes lysozyme, Vitamin B12-binding protein, and beta-glucuronidase, only beta-glucuronidase was present in the basophils in detectable amounts. This enzyme was released, together with histamine, on incubation of the cells with PMA, A23187, or anti-IgE, but not with STZ. We conclude that basophils from normal human blood are not phagocytes and are probably not involved in the oxidative defense of the host against foreign antigens.     

Properties of a panel of monoclonal antibodies which react with the human T cell antigen receptor on the leukemic line HPB-ALL and a subset of normal peripheral blood T lymphocytes

Five Mab raised against the T cell antigen receptor of the human T cell line HPB-ALL which react with a subpopulation of normal peripheral blood T cells are described. Three Mab, 3D6, 1C1, and 1C2, react with 3 to 5% of normal PBL and stimulate proliferation of the cells with which they react. An increase in the number of cells which react with all five Mab occurs. Two Mab, 2D4 and 65, react with subsets of the cells which bind 1C1, 1C2, and 3D6 and divide the family into four subgroups, 2D4+ 65+, 2D4+ 65-, 2D4- 65+, and 2D4- 65-. Functional T cell clones in all four subfamilies have been observed. Cytolytic function can be correlated with the TcR phenotype expressed because all of the Mab which react with a particular clone inhibit its ability to lyse a specific target. The epitopes recognized by the panel are closely related because all five block each other's binding to HPB-ALL. In addition, the determinants recognized by 3D6, 1C1, and 1C2 on normal lymphocytes are probably very closely related because all clones examined react with all three Mab.     

Arbovirological survey in Silica plateau area, Roznava District, Czechoslovakia

The serosurveys conducted in the Silica plateau area of the Slovak karst region revealed the presence of specific neutralizing antibody against tick-borne encephalitis (TBE) virus in 18% of local inhabitants (33 examined, mostly goats and sheep farmers), 54% of goats (26 examined), 18% of sheep (120 examined) and 13% of cattle (60 examined), against Lipovník (LIP) virus in 30% of inhabitants, 88% of goats, 55% of sheep and 45% of cattle, and against Bhanja (BHA) virus in 27% of inhabitants, 46% of goats, 29% of sheep and 23% of cattle. The results of hemagglutination-inhibition tests with TBE and BHA antigens were analogous. A detailed analysis of these serologic data points to a recent enhancement of the circulation of LIP and BHA viruses and to a very low TBE virus activity in this natural focus of arboviral infections. The immunological surveys of the 32 former "Roznava disease" patients, conducted 25 years after an extensive epidemic of a TBE virus infection that originated in Roznava in 1951, revealed the presence of neutralizing (and also hemagglutination-inhibiting) antibodies against TBE virus in as many as 78% of cases. Antibodies against LIP and BHA viruses were also detectable in the sera of 16% and 9%, respectively, of these individuals. Populations of the ectoparasites examined for the presence of arbovirus comprised 231 Ixodes ricinus, 806 Dermacentor marginatus and 204 Haemaphysalis punctata ticks and 117 specimens of the louse-flies Melophagus ovinus. Two strains of arbivirus that were antigenically related to Lipovník and Tribec viruses belonging to a group of Kemerovo viruses were isolated from male and female I. ricinus ticks collected from cattle.     

Androgen metabolism in the human epididymis. Effect of in vivo estrogen administration

Androgen metabolism in human epididymis was studied by incubating tissue fragments with isotopically labeled testosterone (T) and androstenedione (A) under batch and superfusion conditions. Epididymides were obtained from 16 patients with prostatic cancer, 5 of them treated with diethylstilbestrol (2.5 mg/d) for several months prior to castration. Results from batch incubations with [3H]T (100 nM) for 2 h at 25 degrees C indicated a markedly lower 5 alpha-reductase activity in tissues from estrogen-treated patients, as evaluated by measuring the amounts of radioactive 5 alpha-dihydrotestosterone, 5 alpha-androstanediols and 5 alpha-androstanedione present in tissue and medium at the end of the incubation period. Superfusion experiments confirmed this estrogen effect and also showed a shift of the interconversion between A and T towards the reductive direction and a diminished tissue retention of DHT after estrogen treatment. These effects may contribute to the marked regression of the epididymal epithelium that was noted in the estrogen-treated patients, which is thought to be mainly the result of the inhibition of androgen biosynthesis caused by chemical hypophysectomy.     

A backpack system for long-term osmotic minipump infusions into unrestrained marmoset monkeys

A backpack system is described whereby osmotic minipumps are used to infuse gonadotrophin-releasing hormone (GnRH) subcutaneously in a pulsatile manner into infertile socially subordinate female marmoset monkeys (Callithrix jacchus jacchus). This procedure enables long-term infusion of GnRH without the necessity of repeated subcutaneous implantation of pumps and GnRH reservoirs. The backpack and cannulae system is inexpensive and can be constructed from commonly available materials. The GnRH treatment successfully overcame the suppression of pituitary luteinizing hormone secretion imposed by the low social status of female marmoset monkeys.     

Normal serotonin uptake by blood platelets and brain synaptosomes but selective impairment of platelet serotonin storage in mice with Chediack-Higashi syndrome

The Chediack-Higashi syndrome (CHS) is an autosomal recessive disorder reported in man and in several animal species including the "beige mice" (bg/bg). Among several manifestations of this genetic trait, deficiency of secretable substances - including serotonin - normally stored in platelet dense granules is a characteristic feature. The animal model of Chediak-Higashi syndrome used in the present study provides a unique opportunity to compare the kinetics of serotonin (5-hydroxytryptamine, 5-HT) uptake in platelets and brain synaptosomes in conditions of selective reduction of 5HT concentration in the platelets. The kinetics of 5HT uptake, as measured in the present study, was normal in synaptosomes and platelets from the same animals. The lower intraplatelet 5HT levels in bg/bg animals as compared to normal synaptosomes levels in the presence of normal uptake offer an indirect proof that the 5HT defect described in the CHS is due to an impaired 5HT storage mechanism. This is supported by the observation that spontaneous release of 5HT was markedly increased in platelets from CH5 mice but was normal in synaptosomes from the same animals. Thus platelets are a reliable model to study 5HT uptake, but not 5HT storage and release in brain synaptosomes.