Snoring in adults: some epidemiologic aspects.

Although snoring is a common problem it has received little attention in the medical literature. Therefore, a study was undertaken to determine the prevalence and epidemiologic aspects of snoring. The results showed that it is much more common than previously thought--86% of the married men and 57% of the married women were reported to snore. Overall, snoring was found to be more frequent in adult men than women, and its prevalence in adults was not related to age. It was found that 15% of the husbands and 52% of the wives were bothered by their spouse''s snoring. Physicians must be made more aware of this problem and its potential effects on patients.     

Evolutionary aspects of some neuropeptides.

The study of biologically active peptides is a study of structural homology and functional diversity. Some fundamental peptide structures used as chemical messengers by simple organisms were evidently maintained throughout evolution with little change. In higher organisms these structures may still be used for functions related to the original use as well as for very different purposes. Examples are given of the multifunctional roles of common peptides and of the mechanisms by means of which these functions are separated and regulated. The active core of ACTH appears to be used as a signal in regulation of reproduction throughout the range of eukaryotes and also appears in a baffling range of other important proteins. The ubiquitous nature of this peptide sequence suggests that it plays a universal role in recognition or activation of specific receptors. Peptides used in lower species as hormones or chemical defense substances play an important role in research as presagers of the discovery of corresponding mammalian peptides.     

Radiation protection: the NCRP guidelines and some considerations for the future.

The National Council on Radiation Protection and Measurements (NCRP) in the USA and the International Commission on Radiological Protection (ICRP), worldwide, were formed about 1928 and have since made recommendations on appropriate levels of protection from ionizing radiation for workers and for the public. These recommendations and much of the guidance provided by these organizations have usually been adopted by regulatory bodies around the world. In the case of the NCRP, the levels have fallen from 0.1 roentgen per day in 1934 to the current 5 rem per year (a factor of about 5). The present levels recommended by both the ICRP and the NCRP correspond to reasonable levels of risk where the risks of harm from ionizing radiation are compared with the hazards of other, commonly regarded, as safe, industries. Some considerations for the future in radiation protection include trends in exposure levels (generally downward for the average exposure to workers) and improvements in risk estimation; questions of lifetime limits, de minimis levels, and partial body exposures; plus problems of high LET radiations, acceptability of risk, synergisms, and risk systems for protection.     

Cannabidiol: an overview of some chemical and pharmacological aspects. Part I: chemical aspects

Over the last few years considerable attention has focused on cannabidiol (CBD), a major non-psychotropic constituent of Cannabis. In Part I of this review we present a condensed survey of the chemistry of CBD; in Part II, to be published later, we shall discuss the anti-convulsive, anti-anxiety, anti-psychotic, anti-nausea and anti-rheumatoid arthritic properties of CBD. CBD does not bind to the known cannabinoid receptors and its mechanism of action is yet unknown. In Part II we shall also present evidence that it is conceivable that, in part at least, its effects are due to its recently discovered inhibition of anandamide uptake and hydrolysis and to its anti-oxidative effect.     

Population structure of the Indian people: some microevolutionary aspects

Some aspects of population structure, namely village endogamy, marital distance and consanguinity in India are discussed. These parameters show social and geographic variation. The role of culture is of great importance in determining the mating pattern of a population. In the Indian situation, group endogamy in general does not cause inbreeding. Consanguinity is a cultural phenomenon of long-standing tradition, and so far there is no strong indication of a temporal change.     

Radiation protection by Terminalia chebula: Some mechanistic aspects

Radioprotective ability of the aqueous extract of the fruit of Terminalia chebula (TCE) was evaluated for its antioxidant and radioprotective abilities. TCE (50 μg) was able to neutralise 1,1-diphenyl-2-picrylhydrazyl, a stable free radical by 92.9%. The free radical neutralizing ability of TCE was comparable to that of ascorbate (100 μM) 93.5% and gallic acid (100 μM) 91.5% and was higher than that of the diethyldithiocarbamate (200 μM) 55.4%, suggesting the free radical activity of TCE. TCE protected the plasmid DNA pBR322 from undergoing the radiation-induced strand breaks. Radiation damage converts the supercoiled form (ccc) of plasmid to open circular form (oc); the presence of TCE during radiation exposure protected the plasmid from undergoing these damages. The administration of TCE (80 mg/kg body weight, i.p.) prior to whole body irradiation of mice (4 Gy) resulted in a reduction of peroxidation of membrane lipids in the mice liver as well as a decrease in radiation-induced damage to DNA, as assayed by single-cell gel electrophoresis (comet assay). TCE also protected the human lymphocytes from undergoing the gamma radiation-induced damage to DNA exposed in vitro to 2 Gy gamma-radiation. These results suggest the radioprotective ability of TCE.     

Conformational aspects of polypeptides. XXIX. Conformational assignments for some aromatic polypeptides by far-UV Cotton effects. New results

Recent improvements in apparatus permit the examination of circular dichroism (CD) and optical rotatory dispersion (ORD) spectra to 185 mμ. In addition, new solvents which are transparent to 185 mμ have become available for synthetic polypeptides. The spectral region 185–250 mμ is extremely important for the amide (peptide) chromophore, because of the presence at these wavelengths of the n–π* and π–π* bands,¹ and of another transition, the assignment of which remains unsettled.²     

Ultrastructure of Giardia duodenalis trophozoites group from hamster: some relevant aspects.

Trophozoites of Giardia duodenalis group obtained from fragments or scratched of hamster's mucosa were examined by transmission electron microscopy. The fine structure of the trophozoites are presented and compared with those described for other animals. Some of the trophozoites present the cytoplasm full of glycogen, rough endoplasmic reticulum-like structures and homogeneous inclusions not enclosed by membranes, recognized as lipid drops, which had not been observed in Giardia from other animals. The adhesive disk is composed of a layer of microtubules, from which fibrous ribbons extend into the cytoplasm; these ribbons are linked by layer of cross-bridge filaments that shows an intermediary dense band, described for the first time in this paper. The authors regard this band as the result of the cross-bridge filaments slinding in the medium region between adjacent fibrous ribbons, and suggest a contractile activity for them. The role of the adhesive disk on the trophozoite mechanism of attachment to host mucosa is also discussed.     

The steady state kinetics of some biological systems: III. Thermodynamic aspects

Some thermodynamic aspects of steady systems are considered. The time rates of changes, “flux”, of various thermodynamic quantities are formulated. In particular the free energy flux in the steady state, the difference between the free energy flux in the steady and time dependent states and the change in free energy flux upon transition between steady states are discussed. Equations are derived which exhibit the formal similarities and differences between the free energy flux and the conventional free energy change. The temperature dependence of the steady state rate is examined and conditions for “mastery” by a single step discussed. A brief discussion of the role ofrate in the coupling of exergonic and endergonic reactions is given.