The human metallothionein gene cluster is not disrupted in myelomonocytic leukemia

The human metallothionein gene complex on chromosome 16 has been remapped to 16q13 using high-resolution in situ hybridization. The complex is not disrupted by the rearrangement breakpoint on the long arm of chromosome 16 in patients with myelomonocytic leukemia with abnormal eosinophils, as had been previously reported. The locus order on 16q is cen-MT-FRA16B-D16S4-inversion breakpoint-HP-tel.     

Human metallothionein genes: structure of the functional locus at 16q13

The functional human metallothionein (MT) genes are located on chromosome 16q13. We have physically mapped the functional human MT locus by isolation and restriction digest mapping of cloned DNA. The mapped region contains all sequences on chromosome 16 that hybridize to metallothionein gene probes and comprises 14 tightly linked MT genes, 6 of which have not been previously described. This analysis defines the genetic limits of metallothionein functional diversity in the human genome.     

Mediation of 8-hydroxy-guanine formation in DNA by thiazin dyes plus light

We have discovered that methylene blue plus light mediates the formation of 8-OHdG in DNA. Methylene blue is one of several thiazin dyes and we report here that the other thiazin dyes tested, in combination with white light, are effective in mediating 8-OHdG formation in DNA. The effectiveness of light plus the thiazin dyes in forming 8-OHdG in DNA were as follows: methylene blue greater than azure B greater than azure A greater than toluidine blue greater than thionin. Two other compounds tested; riboflavin and fuschin acid, in combination with light, caused formation of very little, if any, 8-OHdG in DNA. Thiazin dye mediated formation of 8-OHdG in DNA was not inhibited by the spin trap alpha-phenyl-t-butyl nitrone, which supports our previous observations that oxygen free radical scavengers did not inhibit methylene blue plus light mediated 8-OHdG formation in DNA. Ascorbate addition to methylene blue plus DNA, in the absence of light, was ineffective in mediating 8-OHdG formation in DNA.     

An extract from Prospects and Risks of Gene Technology: The Report of the Enquete Commission to the Bundestag of the Federal Republic of Germany

We are pleased to publish an English translation of the crucial section on germ line gene therapy from the Report of the German Enquete Commission. This section of the Report raises basic ethical questions concerning embryo research, as well as more specific questions relating to germ line gene therapy. This form of gene therapy involves genetic modification of the germ cells. Such a modification would be passed on to any descendents of the person whose genes had been altered. The Report had previously dealt with somatic gene therapy, which does not affect the germ line and hence is not passed on to descendents.     

Histamine-like immunoreactivity in photoreceptors of the compound eyes and ocelli of the flies Calliphora erythrocephala and Musca domestica

Summary Antibodies to histamine were used for immunocytochemical studies of the visual system in the flies Calliphora erythrocephala and Musca domestica. Specific immunolabeling of photoreceptors was found both in the compound eyes and ocelli of both species. In the compound eyes histamine-like immunoreactivity (HA-IR) was found in all the short visual fibers (photoreceptors R1–6) and one type of long visual fiber (photoreceptor R8). In addition, the ocellar photoreceptors also show HA-IR. In view of earlier biochemical and pharmacological/physiological findings by Elias and Evans (1983) and Hardie (1987) it thus seems likely that histamine is a neurotransmitter in insect photoreceptors. Interestingly, the second type of long visual fiber (photoreceptor R7) has recently been found to be GABA-immunoreactive (Datum et al. 1986). The two types of long visual fibers may hence use different transmitters which act on different receptors of the postsynaptic neurons in the second visual neuropil, the medulla. In addition to the photoreceptors in the retina and ocelli, we found processes of HA-IR neurons in one of the optic lobe neuropils, the lobula. This finding indicates that histamine may also be a transmitter in certain interneurons in the visual system.Abbreviations HA histamine - GABA -amino butyric acid - GAD glutamic acid decarboxylase - 5-HT 5-hydroxytryptamine (serotonin) - HA-IR histamine-like immunoreactivity - R1-R6 class of short-axoned photoreceptors - R7 and R8 long-axoned photoreceptors - LMC large monopolar neuron of lamina - HSA human serum albumin - PBS phosphate-buffered saline - DEPC diethylpyrocarbonate     

Responses of plasma human atrial natriuretic factor to high intensity submaximal exercise in the heat

No data exists regarding responses of human atrial natriuretic factor (ANF) to exercise in the heat. The purpose of this study was to examine the responses of plasma ANF to high intensity submaximal (71% +/- 0.9 VO2max) exercise in the heat over an eight day acclimation period. Fourteen healthy males volunteered to participate in the study. Subjects performed intermittent exercises on a treadmill (0% grade) during 50 min of each 100 min trial in an environmental chamber maintained at 41.2 +/- 0.5 degrees C, 39.0 +/- 1.7% relative humidity. Blood was obtained from an antecubital vein after standing 20 min in the heat prior to exercise, and immediately after exercise. Measures were compared on days 1, 4 and 8. ANF did not change pre- to post-exercise nor did it change over the eight day heat acclimation period despite other heat acclimation adaptations. Conversely, plasma aldosterone (ALDO), renin activity (PRA) and cortisol (COR) all increased (p less than 0.05) pre- to post-exercise on each day but again no changes were observed over the eight day period. These data support that ANF may not increase when ALDO and PRA increases are observed.     

Effect of culture media and growth phase on the morphology of lactobacilli and on their ability to adhere to epithelial cells

Previous studies have demonstrated that the ability of lactobacilli to attach to and colonize uroepithelial surfaces is an important characteristic that enhances interference against uropathogenic bacteria. This adherence capacity was found to vary amongst lactobacillus strains and with the type of growth medium used to culture the organisms. The present study was undertaken to examine further the effect of culture media and growth phase on lactobacillus adherence to uroepithelial cells in vitro. In addition, a freeze substitution technique was developed to examine the morphology of strainsLactobacillus casei ssrhamnosus RC-17,L. casei GR-1, andL. acidophilus T-13 in relation to growth conditions and adhesion. A growth curve was plotted for strain GR-1, and adherence was found to be lowest for bacteria in early log phase (39 bacteria per uroepithelial cell) and highest in stationary phase (59 bacteria per uroepithelial cell). Strains RC-17 and GR-1 attached in high numbers to uroepithelial cells, whereas T-13 was poorly adherent. The latter formed a long, relatively dense, fibrous capsule after growth in brain heart infusion yeast extract agar, unlike strains GR-1 and RC-17, which formed a short, tightly bound, electron-dense capsule which surrounded the cells in a radial fashion. Growth of RC-17 in batch cultures of human urine, with and without addition of carbohydrates, resulted in formation of an irregular, fibrous extracellular matrix. These experiments illustrate that growth phase and culture conditions affect the extracellular structure of lactobacilli and also affect the adherence capacity of these bacteria. Structural changes mediated by availability of nutrients may partly explain why lactobacilli vary between species and between hosts in their colonization of the urogenital tract.     

Recognition of a genus-wide antigen ofLegionella by a monoclonal antibody

A monoclonal antibody was produced against a cytoplasmic membrane protein that appears to be common to all species of the genusLegionella. The antibody was positive in polyacrylamide gel electrophoresis and Western blotting with extracts of all of 22 species type strains ofLegionella that were tested. The apparent molecular mass of the protein varied from 57.2 to 62.1 kilodaltons for the 23 species type strains ofLegionella. An enzyme-linked immunosorbent assay (ELISA) was developed with the monoclonal antibody to enable rapid screening of clinical and environmental isolates forLegionella. All of 23 species type strains ofLegionella that were tested were strongly positive with the monoclonal antibody in the ELISA. Among 27 other bacterial species and 84 strains that were tested, onlyBordetella ssp. andAcinetobacter lwoffii were cross-reactive in the ELISA. These two cross-reactive species are readily distinguishable fromLegionella by culture characteristics. The monoclonal antibody may also be useful in tests to detect the genus-wide antigen in body fluids of patients with legionellosis.     

Blood alcohol concentration and microencephaly: a dose-response study in the neonatal rat

The relationships among microencephaly, peak blood alcohol concentration (BAC), and dose of alcohol were examined in a rat model of third-trimester fetal alcohol effects. Ethyl alcohol was administered to neonatal rats from postnatal day 4 to day 10 during the brain growth spurt via an artificial rearing technique. Groups of rats received one of nine doses of alcohol (0.0, 2.5, 3.3, 4.0, 4.5, 5.3, 6.6, 7.5, or 8.5 g/kg body weight) administered in 8 hours each day. BACs were determined on postnatal days 6 and 7 at times corresponding to peak and trough BACs, respectively. On postnatal day 10, brains were removed, and total brain weights, cerebellar weights and brainstem weights were measured. Pups receiving 4.0 g/kg/day or less had mean peak BACs below 150 mg/dl and did not exhibit significant microencephaly when compared with controls. Higher dosages further increased the peak BAC and produced significant microencephaly. While a dose of 4.5 g/kg/day was sufficient to decrease significantly both total brain weight and cerebellar weight, a minimum dose of 6.6 g/kg/day was required for significant restriction of brainstem weight. The dose of 7.5 g/kg/day yielded a mean peak BAC of 420 mg/dl and reduced total brain weight, cerebellar weight, and brainstem weight by 33%, 52%, and 22%, respectively, relative to controls. Exposure to 8.5 g/kg/day was uniformly lethal. Peak BAC and total brain weight were highly correlated (r = -.916). As peak BAC increased, total brain weight decreased linearly. Comparisons with previous studies indicate that condensing the daily dose of alcohol effectively reduced the threshold doses for microencephaly and lethality.