CoQ10: could it have a role in cancer management?

Coenzyme Q10 or ubiquinone has been shown to have both anti-cancer and immune system enhancing properties when tested in animals. Preliminary results reported here suggest that it might inhibit tumour-associated cytokines. Clinical studies conducted with combination therapies of CoQ10 and other antioxidants are ongoing, but the results are difficult evaluate owing to the lack of proper control groups and of initial randomisation. Also on the basis of some anti-cancer effects of antioxidants reported in literature, further animal studies and a proper clinical trial of coenzyme Q10 in cancer patients are needed.     

Does carnitine have a role in fat absorption?

The effect of D-carnitine and tetradecylglycidic acid (TDGA), an inhibitor of carnitine palmitoyltransferase, on intestinal absorption of palmitic acid was determined. The proximal intestinal segment was ligated in adult male rats and filled with 0.5 microCi of 14C-palmitic acid alone or with either D-carnitine or TDGA. Thirty minutes later the radioactivity was determined in the intestinal lumen, intestinal wall and plasma. The absorption of palmitic acid was decreased in the presence of D-carnitine (10 mg/ml) as evidenced by significantly lower levels of radioactivity in the gut wall and the plasma and by significantly greater residual radioactivity in the lumenal contents. L-carnitine had no effect on plasma radioactivity but if D- and L-carnitine were given together the effect of D-carnitine was still in evidence. TDGA also inhibited intestinal absorption of palmitic acid.     

Does Rbmy have a role in sperm development in mice?

The Y(d1) deletion in mice removes most of the multi-copy Rbmy gene cluster that is located adjacent to the centromere on the Y short arm (Yp). XY(d1) mice develop as females because Sry is inactivated, probably because it is now juxtaposed to centromeric heterochromatin. We have previously produced XY(d1)Sry transgenic males and found that they have a substantially increased frequency of abnormal sperm. Staining of testis sections with a polyclonal anti-RBMY antibody appeared to show a marked decrease of RBMY protein in the spermatids of XY(d1)Sry males compared to control males, which led us to suggest that this may be responsible for the increase in sperm anomalies. In the current study we sought to determine whether augmenting Rbmy expression specifically in the spermatids of XY(d1)Sry males would ameliorate the sperm defects. An expressing Rbmy transgene driven by the spermatid-specific mouse protamine 1 promotor (mP1Rbmy) was therefore introduced into XY(d1)Sry males. This failed to reduce the frequency of abnormal sperm. In the course of this study, a new RBMY antibody was generated that, in contrast to the original antibody, failed to detect RBMY in spermatid stages by immunostaining. The lack of RBMY was confirmed by western blotting of lysates from purified round spermatids and elongating spermatids. The implications of these results for the proposed role for RBMY in sperm development are discussed.     

NAD-dependent hydrogenase from Alcaligenes eutrophus Z1: Does it have a regulatory centre?

Evidence is presented for the existence of a relatively high-potential regulatory centre in the NAD-dependent hydrogenase from the hydrogen oxidizing bacterium Alcaligenes eutrophus Z1. Reduction of the hydrogenase to the redox potentials lower than -100 mV converts the enzyme into a catalytically active state that is remarkably stable to oxidants. Once activated, the enzyme does not loose its activity on intensive oxygenation for at least 3 hours. A novel hydrogenase ESR signal with a wide temperature optimum and a approximately -100 mV midpoint redox potential was detected. We suggest that the reduction of this redox centre trigger conformational changes in the inactive oxidized enzyme molecule, thus reorganizing the latter into the active one.     

High-density lipoprotein: does it have a dark side?

There are proven pleiotropic anti-atherogenic actions of high-density lipoprotein (HDL). However, in systemic inflammation, HDL can have pro-inflammatory properties that may contribute to accelerated atherosclerosis, likely mediated by a change in the structure of HDL to pro-inflammatory HDL (PiHDL). Validation of the technically challenging assay for PiHDL, and confirmation of an association of PiHDL in multiple populations with known risk for atherosclerosis will eventually provide a useful biomarker. Identification of PiHDL in patients with rheumatic disease may help identify patients at risk of accelerated atherosclerosis, and focus our therapeutic interventions.     

Does FSH signaling have a gender?

FSH is the main endocrine control of mammalian reproduction. FSH triggers somatic cells of the gonads which support germ cells metabolically, i.e. Sertoli cells of the seminiferous tubules, and granulosa cells harboring the oocyte, within the ovarian follicle. FSH leads to similar biological responses in both cell types since it stimulates proliferation and differentiation, according to the developmental stage. However, FSH receptor knock-out female mice are infertile, unlike male mice. Hence, FSH is not equally important in both sexes. Nevertheless, does FSH induce distinct signalling mechanisms in its target cells ? Here, we compare the signalling mechanisms induced by FSH in ovarian and testicular physiology.     

Does zoo herpetology have a future?

Fifty-two North American zoo reptile and amphibian departments were surveyed to determine their contributions to recognized American Zoo and Aquarium Association (AZA)-sponsored programs and formalized research projects over the past 10 years. Surveys also requested information concerning the allocation of resources for conservation and research programs, staff educational background, and entry level salaries. Twenty-two institutions responded to the survey, collectively indicating a total of 164 technical papers, 16 field studies, and 101 non-technical articles completed between 1987 and 1997. Of the 164 technical papers published, 130 (79%) were contributed by three institutions. Of the 16 field studies, seven were outside the United States, whereas nine focused on native species and ecosystems. Six of the reported field studies involved only financial or logistical support. Of the 101 non-technical articles, 42 (42%) were contributed by a single institution. Twenty-one formalized in-house research projects were reported. However, only four appeared to have a clearly defined objective. Survey respondents also reported nine species of reptiles and one amphibian taxon are managed by Species Survival Plans (SSPs). There are currently 12 Taxon Advisory Group (TAG) coordinators, with four of the current coordinators having served on multiple TAG committees. There are 41 AZA-approved studbooks for reptiles and two for amphibians, with 29 having actually been published to date. The average starting salary reported in our survey for entry level keeper positions was $19,500 (range, $13,500–30,000). The average level of education reported was high school graduate. There was no correlation between productivity and higher wages, or level of education. Only one institution received funding specifically for research. We conclude that zoo herpetology departments are not realizing their potential for formalized research and conservation projects and propose recommendations for future involvement. Zoo Biol 17:453–462, 1998. © 1998 Wiley-Liss, Inc.     

Does the parallel evolution pattern between the replication-segregation proteins and HU have a biological significance?

The bacterial chromosome is a highly compacted nucleoproteic structure. Its apparent disordered morphology is difficult to conciliate with newly discovered mechanisms governing the propagation of genetic information between mother and daughter cells. Recent experiments in bacterial genetics, biochemistry and cytology from a number of laboratories are beginning to unravel how at each cell division, DNA replication and segregation proteins interact spatially with specific DNA motifs to orchestrate replication and movement of replication forks and chromosomes. We propose here a method to confirm and perhaps extend these experiments by in silico protein sequence comparisons and phylogeny. This analysis showed a parallel evolution between the histone-like protein HU and key protein factors involved in DNA replication and chromosome segregation.     

The World Health Organisation. WHO in Europe: does it have a role?

WHO is under pressure from all sides to justify its existence. Donors want to know what they are getting for their money, and health professionals question the relevance of the organisation''s work. The pressure to justify itself is perhaps strongest of all in Europe, where most member countries have fully fledged health infrastructures and high overall levels of health. Now there is the additional threat of encroachment into the field of public health by the European Union. The disintegration of the Soviet bloc has given WHO''s regional office in Europe a new sense of purpose and led to a major shift in resources towards the countries of central and eastern Europe. But WHO''s critics are calling for a different shift in the way its European office works: from its current concentration on broad based policy issues to the nitty-gritty of health care management and delivery.     

Metapopulation dynamics: Does it help to have more of the same?

With the interest in conservation biology shifting towards processes from patterns, and to populations from communities, the theory of metapopulation dynamics is replacing the equilibrium theory of island biogeography as the population ecology paradigm in conservation biology. The simplest models of metapopulation dynamics make predictions about the effects of habitat fragmentation - size and isolation of habitat patches - on metapopulation persistence. The simple models may be enriched by considerations of the effects of demographic and environmental stochasticity on the size and extinction probability of local populations. Environmental stochasticity affects populations at two levels: it makes local extinctions more probable, and it also decreases metapopulation persistence time by increasing the correlation of extinction events across populations. Some controversy has arisen over the significance of correlated extinctions, and how they may affect the optimal subdivision of metapopulations to maximize their persistence time.     

Does glucagon have a positive inotropic effect in the human heart?

Glucagon is considered to exert cardiostimulant effects, most notably the enhancement of heart rate and contractility, due to the stimulation of glucagon receptors associated with Gs protein stimulation which causes adenylyl cyclase activation and the consequent increase in 3′,5′-cyclic adenosine monophosphate production in the myocardium. These effects have been extensively demonstrated in experimental studies in different animal species. However, efforts to extrapolate the experimental data to patients with low cardiac output states, such as acute heart failure or cardiogenic shock, have been disappointing. The experimental and clinical data on the cardiac effects of glucagon are described here.     

Does the 'non-coding' strand code?

The hypothesis that DNA strands complementary to the coding strand contain in phase coding sequences has been investigated. Statistical analysis of the 50 genes of bacteriophage T7 shows no significant correlation between patterns of codon usage on the coding and non-coding strands. In Bacillus and yeast genes the correlation observed is not different from that expected with random synonymous codon usage, while a high correlation seen in 52 E. coli genes can be explained in terms of an excess of RNY codons. A deficiency of UUA, CUA and UCA codons (complementary to termination) seems to be restricted to the E. coli genes, and may be due to low abundance of the relevant cognate tRNA species. Thus the analysis shows that the non-coding strand has the properties expected of a sequence complementary to a coding strand, with no indications that it encodes, or may have encoded, proteins.