HIV/AIDS in Asia: The shape of epidemics and their molecular epidemiology

The Asia-Pacific region is a home to 60% of the population in the world and to approximately one quarter of people with HIV/AIDS. Close to a million of people has been infected and a half million people died of AIDS annually in Asia, becoming the second largest epicenter of global AIDS epidemic. Molecular epidemiology has been useful tool to track a course of HIV spread. In-depth knowledge from the studies on molecular epidemiology elucidates the dynamics of HIV spread and the interrelationship of epidemics in the different regions in Asia. Foundation items: Grant support from Ministry of Health, Labour and Welfare and Ministry of Education, Science and Technology in Japan; Japanese Foundation for AIDS Prevention.     

Leber congenital amaurosis and retinitis pigmentosa with Coats-like exudative vasculopathy are associated with mutations in the crumbs homologue 1 (CRB1) gene

Mutations in the crumbs homologue 1 (CRB1) gene cause a specific form of retinitis pigmentosa (RP) that is designated "RP12" and is characterized by a preserved para-arteriolar retinal pigment epithelium (PPRPE) and by severe loss of vision at age <20 years. Because of the early onset of disease in patients who have RP with PPRPE, we considered CRB1 to be a good candidate gene for Leber congenital amaurosis (LCA). Mutations were detected in 7 (13%) of 52 patients with LCA from the Netherlands, Germany, and the United States. In addition, CRB1 mutations were detected in five of nine patients who had RP with Coats-like exudative vasculopathy, a relatively rare complication of RP that may progress to partial or total retinal detachment. Given that four of five patients had developed the complication in one eye and that not all siblings with RP have the complication, CRB1 mutations should be considered an important risk factor for the Coats-like reaction, although its development may require additional genetic or environmental factors. Although no clear-cut genotype-phenotype correlation could be established, patients with LCA, which is the most severe retinal dystrophy, carry null alleles more frequently than do patients with RP. Our findings suggest that CRB1 mutations are a frequent cause of LCA and are strongly associated with the development of Coats-like exudative vasculopathy in patients with RP.     

Membrane topology of the lactococcal bacteriocin ATP-binding cassette transporter protein LcnC. Involvement of LcnC in lactococcin a maturation

Many non-lantibiotic bacteriocins of lactic acid bacteria are produced as precursors with N-terminal leader peptides different from those present in preproteins exported by the general sec-dependent (type II) secretion pathway. These bacteriocins utilize a dedicated (type I) secretion system for externalization. The secretion apparatus for the lactococcins A, B, and M/N (LcnA, B, and M/N) from Lactococcus lactis is composed of the two membrane proteins LcnC and LcnD. LcnC belongs to the ATP-binding cassette transporters, whereas LcnD is a protein with similarities to other accessory proteins of type I secretion systems. This paper shows that the N-terminal part of LcnC is involved in the processing of the precursor of LcnA. By making translational fusions of LcnC to the reporter proteins beta-galactosidase (LacZ) and alkaline phosphatase (PhoA*), it was shown that both the N- and C-terminal parts of LcnC are located in the cytoplasm. As the N terminus of LcnC is required for LcnA maturation and is localized in the cytoplasm, we conclude that the processing of the bacteriocin LcnA to its mature form takes place at the cytosolic side of the cytoplasmic membrane.     

Cloning and characterization of a cDNA encoding a novel fibroblast growth factor preferentially expressed in human heart

A novel human fibroblast growth factor (hFGF), which shows 75% sequence homology with fibroblast growth factor-9, was isolated in random sequencing of a human heart cDNA library. The full-length sequence is 928 bp, the encoded protein is composed of 168 amino acid residues, and its pI value and molecular weight were estimated to be 8.13 and 19.1 kDa, respectively. RT-PCR using Marathon human heart cDNA shows that the coding region is approximately 507 bp. Southern hybridization showed a single band which indicates that this is a single copy gene. Northern hybridization done on a human multiple tissues blot showed that the gene is preferentially expressed in human heart, very weakly detectable in human brain and not detectable in 18 other different human tissues.     

Fine structure of the gill epithelium of the terrestrial mudskipper, Periophthalmodon schlosseri

In this paper, we describe the fine structure of the branchial epithelium of the amphibious, air-breathing mudskipper Periophthalmodon schlosseri, and relate the observed structure to functions in gas exchange, and to the elimination of sodium chloride and ammonia. Also, we describe the fine structure of the opercular epithelimicrom. The gill lamellar epithelium is thickened by the presence of large mitochondria-rich (MR) cells. These MR cells are further characterized by an extensive tubular system that is continuous with the basolateral plasma membrane and by a deep apical crypt often lined with microvilli. There are very few specialized MR accessory cells, which are associated with NaCl excretion in marine teleosts. Instead, MR cells are commonly isolated from each other laterally by flattened cells rich in intermediate filaments. These filament-rich (FR) cells are interconnected by desmosomes and have unusual canaliculi. These branchial FR cells are unique to P. schlosseri and may have a structural role. Electron-dense pavement cells rich in vesicles and large vacuous mitochondria compose the superficial layer of the epithelium. The unusual morphology of P. schlosseri's gill lamellae may be related to the animal's ability to effectively eliminate ammonia during air exposure. The inner opercular lining and parts of the leading edge of the filament have intraepithelial capillaries, which provide a more suitable gas exchange surface than the thickened lamellae with its restricted interlamellar water spaces. The arrangement of respiratory and ion exchange epithelia is opposite to that found in all other fish in which the lamellae typically function in gas exchange and the gill filament in ion regulation.     

Sour taste preferences of children relate to preference for novel and intense stimuli

Previous research has suggested that some children have a preference for sour tastes. The origin of this preference remains unclear. We investigated whether preference for sour tastes is related to a difference in rated sour intensity due to physiological properties of saliva, or to an overall preference for intense and new stimuli. Eighty-nine children 7-12 years old carried out a rank-order procedure for preference and category scale for perceived intensity for four gelatins (i.e. 0.0 M, 0.02 M, 0.08 M, 0.25 M added citric acid) and four yellow cards that differed in brightness. In addition, we measured their willingness to try a novel candy and their flow and buffering capacity of their saliva. Fifty-eight percent of the children tested preferred one of the two most sour gelatins. These children had a higher preference for the brightest color (P < 0.05) and were more likely to try the candy with the unknown flavor (P < 0.001) than children who did not prefer the most sour gelatins. Preference for sour taste was not related with differences in rated sour intensity, however those who preferred sour taste had a higher salivary flow (P < 0.05). These findings show that a substantial proportion of young children have a preference for extreme sour taste. This appears to be related to the willingness to try unknown foods and preference for intense visual stimuli. Further research is needed to investigate how these findings can be implemented in the promotion of sour-tasting food such as fruit.     

Atypical presentation of depression in the elderly: fact or fiction?

Depression in the elderly is often thought to have a different clinical presentation in many patients. This so-called atypical depression is characterised by less sadness and feelings of guilt and more somatic symptoms, impaired cognition and behavioural symptoms. Studies that compare depressive signs and symptoms in elderly and younger patients are reviewed. Published studies do not support the suggestion that major depression in the elderly often have a different clinical presentation. Vascular depression and depression in patients with severe dementia may be exceptions. Conceptual and methodological issues that play an important role are discussed.     

Pulsatile LH release is diminished, whereas FSH secretion is normal, in hypocretin-deficient narcoleptic men

Hypocretin (orexin) peptides are involved in the regulation of energy balance and pituitary hormone release. Narcolepsy is a sleep disorder characterized by disruption of hypocretin neurotransmission. Pituitary LH secretion is diminished in hypocretin-deficient animal models, and intracerebroventricular administration of hypocretin-1 activates the hypothalamo-pituitary-gonadal axis in rats. We evaluated whether hypocretin deficiency affects gonadotropin release in humans. To this end, we deconvolved 24-h serum concentrations of LH and FSH in seven hypocretin-deficient narcoleptic males (N) and seven controls (C) matched for age, body mass index, and sex. Basal plasma concentrations of testosterone, estradiol, and sex hormone-binding globulin were similar in both groups. Mean 24-h LH concentration was significantly lower in narcolepsy patients [3.0 +/- 0.4 (N) vs. 4.2 +/- 0.3 (C) U/l, P = 0.01], which was primarily due to a reduction of pulsatile LH secretion [23.5 +/- 1.6 (N) vs. 34.3 +/- 4.9 (C) U.l(-1).24 h(-1), P = 0.02]. The orderliness of LH and FSH secretion, quantitated by the approximate entropy statistic, was greater in patients than in controls. In contrast, all other features of FSH release were similar in narcoleptic and control groups. Also, LH and FSH secretions in response to intravenous administration of 100 microg of GnRH were similar in patients and controls. These data indicate that endogenous hypocretins are involved in the regulation of the hypothalamo-pituitary-gonadal axis activity in humans. In particular, reduced LH release in the face of normal pituitary responsivity to GnRH stimulation in narcoleptic men suggests that hypocretins promote endogenous GnRH secretion.