Lung cancer and indoor air pollution in Xuan Wei, China

In Xuan Wei County, Yunnan Province, lung cancer mortality is among China's highest and, especially in females, is more closely associated with indoor burning of "smoky" coal, as opposed to wood or "smokeless" coal, than with tobacco smoking. Indoor air samples were collected during the burning of all three fuels. In contrast to wood and smokeless coal emissions, smoky coal emission has high concentrations of submicron particles containing mutagenic organics, especially in aromatic and polar fractions. These studies suggested an etiologic link between domestic smoky coal burning and lung cancer in Xuan Wei.     

Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response

In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.     

Halophytes are promising sources for producing biofuel

The that the arid regions of Russia and Central Asiatic countries have an inexhaustible potential for the development of the raw materials base of biofuel power engineering is shown: vast territories of yet uncultivated lands, surplus of solar energy, large reserves of saline water, and significant genetic resources of halophytes that are plants with maximum resistance to salt stress. According to the data of experiments, in case of irrigation with saline water, halophytes form 15–18 and more t/ha of dry biomass in the arid regions of Russia, Uzbekistan, and Kazakhstan, which is comparable with lucerne irrigated with fresh water. The task of expanding and deepening the research into the use of halophyte resources for obtaining biofuel in the arid regions of Russia is stated to be urgent.     

The genome of the diatom Thalassiosira pseudonana: ecology, evolution, and metabolism

Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 20% of global carbon fixation. We report the 34 million-base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand-base pair plastid and 44 thousand-base pair mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.     

Seasonal fluctuation of parasitic infestation in donkeys (Equus asinus) in Oodi village,Kgatleng District,Botswana

During the period March to September 2000, a study was conducted in Oodi village, Kgatleng District, Botswana, to investigate the seasonal fluctuation of internal, external and blood parasites of donkeys. Twelve adult donkeys were randomly selected from a farmer with a herd of 15 donkeys. Monthly visits were made to the farmer when the donkeys were examined for parasites. The only ectoparasites recovered from the donkeys were instars of various tick species. The most prevalent tick was Rhipicephalus evertsi evertsi (98.4%), followed by Amblyomma hebraeum and Hyalomma species. The only haemoparasite seen on microscopy was Babesia equi at low parasitaemia in 26.8% of the donkeys. However, no clinical babesiosis was evident. Coprological examination showed the presence of strongyle eggs in moderate numbers. Very low numbers of coccidia oocysts were found in the faecal samples. High tick numbers and worm egg counts coincided with the warm, wet months in contrast to the low numbers recovered during the cold, dry months. An interview conducted by the authors indicated that donkeys were nutritionally marginalised by owners. Supplementary feeding was therefore recommended, especially during the winter months when grazing is poor.     

A persistent untranslated sequence within bacteriophage T4 DNA topoisomerase gene 60

A 50-nucleotide untranslated region is shown to be present within the coding sequence of Escherichia coli bacteriophage T4 gene 60, which encodes one of the subunits for its type II DNA topoisomerase. This interruption is part of the transcribed messenger RNA and appears not to be removed before translation. Thus, the usual colinearity between messenger RNA and the encoded protein sequence apparently does not exist in this case. The interruption is bracketed by a direct repeat of five base pairs. A mechanism is proposed in which folding of the untranslated region brings together codons separated by the interruption so that the elongating ribosome may skip the 50 nucleotides during translation. The alternative possibility, that the protein is efficiently translated from a very minor and undetectable form of processed messenger RNA, seems unlikely, but has not been completely ruled out.     

Identification and characterization of a virus infecting pepper in Southern Primorskii Krai

Infection of pepper caused by an isometric virus with a 30 ± 3 nm virion diameter is revealed. The thermal inactivation point of virus in jimsonweed sap is 75–80°C, longevity in vitro 3 days at 25°C, and dilution end-point of virus 10^?3–10^?4. The capsid of the virus contains two types of protein with molecular mass 55 and 12.6 kDa. A distant antigenic relatedness to the tobacco ringspot virus of the genus Nepovirus is shown.     

Splice variants of the alpha subunit of the G protein Gs activate both adenylyl cyclase and calcium channels

Signal transducing guanine nucleotide binding (G) proteins are heterotrimers with different alpha subunits that confer specificity for interactions with receptors and effectors. Eight to ten such G proteins couple a large number of receptors for hormones and neurotransmitters to at least eight different effectors. Although one G protein can interact with several receptors, a given G protein was thought to interact with but one effector. The recent finding that voltage-gated calcium channels are stimulated by purified Gs, which stimulates adenylyl cyclase, challenged this concept. However, purified Gs may have four distinct alpha-subunit polypeptides, produced by alternative splicing of messenger RNA. By using recombinant DNA techniques, three of the splice variants were synthesized in Escherichia coli and each variant was shown to stimulate both adenylyl cyclase and calcium channels. Thus, a single G protein alpha subunit may regulate more than one effector function.     

Observations on mineral transformations and potential environmental consequences during the oxidation of iron sulphide‐rich materials in incubation experiments

This paper attempts to acquire a good understanding of the formation and evolution of acid sulphate soils (ASS), as well as to assess the consequent environmental impacts. An incubation experiment to simulate the development of ASS under various weathering scenarios was set up. Fresh monosulphidic black ooze (MBO) material was divided into three parts and each was subjected to different drying and rewetting regimes by controlling an artificial water table in an incubation cell. The observations focused on the changes in mineralogy of the material and reflectance spectral changes during the oxidation process, and the ionic composition and chemical status of the solutions generated. Mineralogical investigations with hyperspectral and XRD analysis showed that frequent inundation produced extensive surface oxidation and a change from iron sulphide minerals to stable end members such as goethite. For the material experiencing moderate or occasional inundation, oxidation was less advanced and a different secondary mineral suite, with iron sulphate minerals such as jarosite, was present. Solutions generated from all the incubation cells were generally acidic with pH around 3.5, indicating that sulphide oxidation occurred rapidly in all cells. Sulphate concentrations in solutions from the different cells were calculated from the measurements of SO₄^2? and other anions in solutions and may approximate the rates of sulphide oxidation. Potential environmental impacts were illustrated in terms of soil acidity, salinity and trace metal release, and the effects of the different wetting/drying regimes on the oxidative process also provided insight into potential weathering effects in a changing climate.     

Endothelin stimulation of cytosolic calcium and gonadotropin secretion in anterior pituitary cells

The presence of endothelin, a vasoconstrictor peptide, in the hypothalamus and posterior pituitary suggests that it also regulates neural and other nonvascular target cells. In pituitary gonadotrophs, low doses of endothelin evoked oscillations in the intracellular calcium concentration, and high doses induced a biphasic calcium response. Mobilization of intracellular calcium predominated during the spike phase of the calcium response to endothelin, whereas calcium entry through dihydropyridine-sensitive channels contributed to both the spike and plateau phases of the calcium response. Endothelin was a potent as hypothalamic gonadotropin-releasing hormone (GnRH) in stimulation of gonadotropin release in perifused pituitary cells. Endothelin bound specifically to pituitary cells with a dissociation constant of 70 picomolar, and induced rapid formation of inositol trisphosphate and diacyglycerol. Although intracellular calcium concentration and gonadotropin secretory responses to endothelin were independent to the GnRH receptor, endothelin and GnRH appeared to have a common signal transduction mechanism. These observations suggest that endothelin can act as a neuropeptide to regulate anterior pituitary function.