Baboon vaginal microbiota: an overlooked aspect of primate physiology

The bacterial population of the primate vaginal canal is an infant primate's first exposure to the microbial population inhabiting the outside world. Yet, little is known about this population and the effect it might have on the development and survival of the infant primate. As a first step toward characterizing the vaginal microbiota of a nonhuman primate, we used denaturing gradient gel electrophoresis to evaluate variations in the vaginal microbiota of a group of 35 baboons (Papio hamadryas), which were housed in a facility where they shared the same diet and the same environmental conditions. We found that, despite the uniform environment, there were appreciable differences in the composition of the microbiota from one individual to another. Our results also indicate that a simple swab test is sufficient for sampling the vaginal microbiota in the field, a finding that should help make more detailed characterization of the microbiota of wild primates feasible in the future. Am. J. Primatol. 72:467–474, 2010. © 2010 Wiley‐Liss, Inc.     

Biochemistry and physiology of plant hormones

Book Review

Biochemistry and physiology of plant hormonesT.C. Moore, 2nd edition. Berlin, Heidelberg, New York, London, Paris, Tokyo, Hong Kong: Springer-Verlag, 1989. xv + 350 pages. DM 98.00. ISBN 3-540-9684-5     

Late life: a new frontier for physiology

Late life is a distinct phase of life that occurs after the aging period and is now known to be general among aging organisms. While aging is characterized by a deterioration in survivorship and fertility, late life is characterized by the cessation of such age-related deterioration. Thus, late life presents a new and interesting area of research not only for evolutionary biology but also for physiology. In this article, we present the theoretical and experimental background to late life, as developed by evolutionary biologists and demographers. We discuss the discovery of late life and the two main theories developed to explain this phase of life: lifelong demographic heterogeneity theory and evolutionary theory based on the force of natural selection. Finally, we suggest topics for future physiological research on late life.     

Exploiting host microtubule dynamics: a new aspect of bacterial invasion

During infection, many pathogenic bacteria modulate the actin cytoskeleton of eukaryotic host cells to facilitate various infectious processes such as the attachment to or invasion of epithelial cells. Additionally, some pathogenic bacteria are capable of modulating the dynamics of host microtubule (MTs). Although the molecular basis for this is still poorly understood, a recent study of the Shigella VirA effector protein, which is delivered via a type III secretion system, suggests that MT destabilization plays an important role in Shigella infection.     

Thyroid hormones and their effects: a new perspective

The thyroid hormones are very hydrophobic and those that exhibit biological activity are 3',5',3,5-L-tetraiodothyronine (T4), 3',5,3-L-triiodothyronine (T3), 3',5',3-L-triiodothyronine (rT3) and 3,5',-L-diiothyronine (3,5-T2). At physiological pH, dissociation of the phenolic -OH group of these iodothyronines is an important determinant of their physical chemistry that impacts on their biological effects. When non-ionized these iodothyronines are strongly amphipathic. It is proposed that iodothyronines are normal constituents of biological membranes in vertebrates. In plasma of adult vertebrates, unbound T4 and T3 are regulated in the picomolar range whilst protein-bound T4 and T3 are maintained in the nanomolar range. The function of thyroid-hormone-binding plasma proteins is to ensure an even distrubtion throughout the body. Various iodothyronines are produced by three types of membrane-bound cellular deiodinase enzyme systems in vertebrates. The distribution of deiodinases varies between tissues and each has a distinct developmental profile. Thyroid hormones. (1) the nuclear receptor mode is especially important in the thyroid hormone axis that controls plasma and cellular levels of these hormones. (2) These hormones are strongly associated with membranes in tissues and normally rigidify these membranes. (3) They also affect the acyl composition of membrane bilayers and it is suggested that this is due to the cells responding to thyroid-hormone-induced membrane rigidificataion. Both their immediate effects on the physical state of membranes and the consequent changes in membrane composition result in several other thyroid hormone effects. Effects on metabolism may be due primarily to membrane acyl changes. There are other actions of thyroid hormones involving membrane receptors and influences on cellular interactions with the extracellulara matrix. The effects of thyroid hormones are reviewed and appear to b combinations of these various modes of action. During development, vertebrates show a surge in T4 and other thyroid hormones, as well as distinctive profiles in the appearance of the deiodinase enzymes and nuclear receptors. Evidence from the use of analogues supports multiple modes of action. Re-examination of data from th early 1960s supports a membrane action. Findings from receptor 'knockout' mice supports an important role for receptors in the development of the thyroid axis. These iodothyronines may be better thought of as 'vitamone'-like molecules than traditional hormonal messengers.     

An approach to primary prevention from the aspect of applied physiology

The main reason for our decreasing population number--a most remarkable indicator of the inadequacy of our health culture--is the high rate of overall mortality. In its background one finds a number of risk factors of high prevalence, such as hypertension disease, addiction pathology, reduced stress tolerance as well as physical and psychic inactivity. Patterns of life that are positive are scarce and as yet not attractive or efficient. The spirit of primary prevention is yet far from permeating medicine; the most the clinical side did realize has been a recognition of the population's need for regular medical screenings. A completely new approach that involves prevention programs embracing the whole of society, and an elaboration of new strategies are badly needed to achieve a desirable change in the present set of values. One of the already available remedies is to give full and science-based support to the positive life patterns in our culture, for instance by demonstrating how physiology can be applied to human life, by putting the latter within a broader scope, namely that of psychophysiology and social psychology. In this framework the elements to be discussed are such aspects of culture as dietary habits, physical exercise, and mental and sexual hygiene. Placing greater emphasis on sports and intense habitual physical exercise can promote a healthier lifestyle, above all in our youth.     

Salivary protein polymorphism in Kenya: evidence for a new AMY1 allele

Salivary protein polymorphism was studied in 200 schoolboys, mainly Kisii and Luo from Kenya, East Africa. The frequencies of PR, PA, DB, PB and AMY1 genes were as follows: PR*1: 0.66, PA*(+): 0.18, DB*(+): 0.55, PB*2: 0.12, AMY1*A2: 0.008, AMY1*E: 0.03. These frequencies were compared with other population data, in particular from West African and US Negroes. The most interesting finding with respect to the gene frequencies is the low PB*2 frequency and the absence of AMY1*3 in Kenya. Furthermore, a new phenotype in the AMY1 system was described which suggests the presence of an allele with an estimated frequency of 0.02.     

Sex hormone-binding globulin: Anatomy and physiology of a new regulatory system

Sex hormone-binding globulin (SHBG) is a plasma glycoprotein that binds a number of circulating steroid hormones (testosterone, dihydrotestosterone and estradiol) with high affinity, thus regulating their free concentration in plasma. In addition to binding steroids, SHBG itself binds to receptor sites on plasma membranes with somewhat unusual kinetics. Both the off and on rates are quite slow. The steroid-binding and membrane-binding functions are interwined in what is clearly an allosteric relationship. Occupation of SHBG's steroid-binding site by a steroid inhibits its ability to bind to its membrane receptor-binding site. This inhibition is not related to a steroid's biological activity. Metabolites of steroids without biological activity, e.g. 2-methoxyestradiol, actively inhibit SHBG's interaction with its membrane receptor. However, if unliganded SHBG is allowed to bind to its receptor on intact cells, and an appropriate steroid hormone then is introduced, adenylate cyclase is activated and intracellular cAMP increases. This function is specific for steroids with biological activity, 2-methoxyestradiol has no activity in this arena. These observations demonstrate a potentially important role for SHBG as a regulator of cell function. They also demonstrate an additional mode of action of steroid hormones, one that does not require that the steroid interact with a steroid receptor.     

Salivary vitamins E and C in oral cancer

Lipid peroxidation may be involved in cancer and essential nutrients that can scavenge free radicals, such as vitamins E and C, operate in concert. Levels of antioxidant vitamins E and C were estimated in 50 patients with oral cancer and 24 healthy persons served as control. Significantly lower levels of vitamins E and C were observed in oral cancer patients as compared to controls (P < 0.011). Antioxidant nutrients may be utilized to a greater extent in oral cancer patients to counteract free radical-mediated cell disturbances, resulting in a reduction in salivary antioxidant levels.     

Strigolactones: new plant hormones in action

Main conclusion

The key step in the mode of action of strigolactones is the enzymatic detachment of the D-ring. The thus formed hydroxy butenolide induces conformational changes of the receptor pocket which trigger a cascade of reactions in the signal transduction.

Abstract

Strigolactones (SLs) constitute a new class of plant hormones which are of increasing importance in plant science. For the last 60 years, they have been known as germination stimulants for parasitic plants. Recently, several new bio-properties of SLs have been discovered such as the branching factor for arbuscular mycorrhizal fungi, regulation of plant architecture (inhibition of bud outgrowth and of shoot branching) and the response to abiotic factors, etc. To broaden horizons and encourage new ideas for identifying and synthesising new and structurally simple SLs, this review is focused on molecular aspects of this new class of plant hormones. Special attention has been given to structural features, the mode of action of these phytohormones in various biological actions, the design of SL analogs and their applications.

     

Salivary analytes in patients with oral squamous cell carcinoma

Literature data indicates that measurement of certain salivary constituents might serve as a useful diagnostic/prognostic tool in the patients with oral squamous cell carcinoma (OSCC). In 24 patients with OSCC (60 +/- 2.5 yrs) and in 24 controls (24 +/- 3.7 yrs) we have determined levels of salivary magnesium, calcium, copper, chloride, phosphate, potassium, sodium, total proteins and amylase. Sodium, potassium and chloride were determined by indirect potentiometry whereas copper, magnesium and phosphate were determined by atomic absorption spectrophotometry. Total proteins were determined by pyrogalol colorimetric method. Amylase levels were determined by continued colorimetric method. Statistical analysis was performed by use of chi2 test and Spearman's correlation test. The results of this study indicate that the concentrations of sodium and chloride were significantly elevated in patients with OSCC when compared to the controls. However, level of total protein was significantly decreased when compared to the healthy controls. Furthermore, there was a negative correlation between alcohol consumption and total protein concentration in patients with oral carcinoma. We might conclude that in patients with OSCC increased salivary sodium and chloride might reflect their overall dehydration status due to alcohol consumption rather than consequence of OSCC itself.     

Salivary proteins as predictors and controls for oral health

We will provide a translational view of using the recent technological advances in dental research for predicting, monitoring, and preventing the development of oral diseases by investigating the diagnostic and therapeutic role of salivary proteins. New analytical state-of-the-art technologies such as mass spectrometry and atomic force microscopy have revolutionized the field of oral biology. These novel technologies open avenues for a comprehensive characterization of the salivary proteins followed by the evaluation of the physiological functions which could make possible in a near future the development of a new series of synthetic protein for therapeutic propose able to prevent global oral diseases such as periodontal disease and dental caries, the two most prevalent oral diseases in the World.     

Salivary levels of tumor necrosis factor-alpha in oral lichen planus

OBJECTIVE: Oral lichen planus (OLP) is chronic inflammatory disease of the oral mucosa, presenting in various clinical forms. The etiology of OLP is still unknown but mounting evidence points to the immunologic basis of this disorder. AIM: Our study was undertaken to quantify the salivary levels of pro-inflammatory tumor necrosis factor-alpha (TNF-alpha) in the reticular and the erosive/atrophic forms of OLP, compared with age-matched healthy control volunteers. SUBJECTS AND METHODS: Whole saliva from 40 patients with active lesions of OLP, as well as from 20 healthy persons, was investigated for the presence of TNF-alpha by enzyme immunoassay. RESULTS: Salivary TNF-alpha levels were significantly increased in patients with OLP in comparison with healthy subjects. The presence of TNF-alpha showed positive correlation to clinical forms of OLP, being significantly higher in the erosive/atrophic type than in the reticular type of disease. CONCLUSION: Saliva provides an ideal medium for the detection of pro-inflammatory markers of the oral cavity. In patients with OLP, TNF-alpha levels in saliva are elevated, correlating with the severity of illness. Salivary TNF-alpha analysis may be a useful diagnostic tool and a potential prognostic marker in OLP.