Insitu nick translation, an alternative to cytogenetics in analyzing mutagen effects on human-cells

A chromosomal break indicates a double-stranded DNA break of the chromatin fiber. Cytogenetic observations can enumerate chromosome breaks but cannot detect single-stranded DNA breaks (nicks). When a high frequency of chromosomal breaks occurs in a cell population, whether spontaneously occurred or mutagen induced, a higher frequency of nicks is expected. In order to correlate these two type of DNA lesions, we used human lymphoblastoid lines known to be either hypersensitive or relatively resistant to the genotoxicity of bleomycin. The frequency of nicks was estimated by grain counts over interphase nuclei in autoradiographs following the technique of in situ nick translation. Good agreement was found between these two sets of data, viz, hypersensitive lines showed a high frequency of chromatid breaks as well as a high frequency of grain counts, and vice versa. These results suggest that the phenomenon of differential bleomycin sensitivity is genetically determined.

Stress and exercise among the Japanese elderly

This study seeks to replicate and extend research on the stress process by examining the relationships among stress, social support, physical exercise, and depressive symptoms with data provided by a recent nationwide survey of older adults in Japan. The findings reveal that more frequent physical exercise is associated with less psychological distress. Moreover, the data suggest that some (but not all) types of stressors tend to diminish the frequency of physical activity. Finally, and perhaps most important, the results reveal that social support tends to promote more frequent exercise. This can occur in two ways. First, more emotional support was related to better exercise habits. In addition, negative interaction was also associated with more frequent exercise, suggesting that informal social sanctions can foster positive health behaviors.

Patterns of nonresponse in a national survey of elderly Japanese

Data from a nationwide sample of older adults in Japan were analyzed to determine patterns of unit nonresponse. Maximum likelihood logistic regression analyses identified age, sex, geographic region, and urbanicity as significant predictors of response status. The probability of nonresponse was higher for men, persons living in certain regions, and those in large urban areas. Age had a curvilinear relationship with response status; the probability of nonresponse decreased from age 60 to age 70, and then increased again with the highest rates at the oldest ages. When nonrespondents were disaggregated into three different groups based on reason for nonparticipation (i.e., refusals, not-at-homes, other reasons), variation in the results was found. For example, while men were more likely than women to refuse an interview or be absent from home during the survey period, they were no more likely to not participate for other reasons. Use of different response rate calculations and a substitution sampling procedure were not found to seriously affect study results.

Plasma lipoproteins, biliary lipids and bile acid profile differ in various strains of Syrian hamsters Mesocricetus auratus

1. Plasma and biliary lipids were assessed in four strains of Syrian hamsters [Charles River Lakeview, (CHR), Biobreeder F1B (BIO), Harlan Sprague-Dawley (HAR) and Sasco (SAS)] fed a cholesterol-free diet. 2. Plasma cholesterol differed with SAS > CHR > HAR > BIO. 3. BIO Hamsters had the lowest HDL and highest VLDL + LDL/HDL ratio, but their biliary secretion of bile acids, phospholipids and cholesterol was 50% lower than other hamsters. 4. Chenodeoxycholate was highest in CHR and the cholate:cheno ratio depressed in CHR hamsters. 5. CHR hamsters had the highest lithogenic index and cholesterol-saturated bile.

Two new taxane diterpenoids from Taxus mairei

Two new taxane diterpenoids were isolated from the heartwood of Taxus mairei and identified as 5 alpha, 7 beta, 9 alpha, 10 beta, 13 alpha-pentaacetoxy-2 alpha-benzoyloxy-4 alpha, 20-dihydroxytax-11-ene [2] and 7 beta, 9 alpha, 10 beta, 13 alpha, 20-pentaacetoxy-2 alpha-benzoyloxy-4 alpha, 5 alpha-dihydroxytax-11-ene[3]. The structures of 2 and 3 were determined primarily on the basis of analysis of their 1H-nmr, 13C-nmr, 1H-1H 2D COSY, 1H-13C 2D COSY, DEPT, and mass spectra. This is the first report of naturally occurring taxoids lacking a D ring but oxygenated at the 4, 5, and 20 positions.

Cholesterol gallstone induction in hamsters reflects strain differences in plasma lipoproteins and bile acid profiles

Because different strains of hamsters vary in their susceptibility to gallstones, the relationship between plasma lipoproteins, hepatic cholesterol, bile lipids and bile acid profile was examined during gallstone induction in strains of male Syrian hamsters from Charles River Lakeview (CHR), Biobreeder F1B (BIO) and Harlan Sprague-Dawley (HAR). Gallstones were induced by feeding a purified diet containing 0.4 or 0.8% cholesterol for 5 wk. Basal plasma total cholesterol was similar, but the hypercholesterolemia induced by dietary challenge was significantly lower in CHR than in HAR and BIO hamsters. Cholesterol-fed CHR hamsters transported cholesterol mainly in HDL (47%), whereas VLDL-C + IDL-C predominated in BIO and HAR hamsters, and their HDL transported only 28 and 38%, respectively. HAR hamsters accumulated the most hepatic cholesterol, revealed the highest cholate/cheno ratio, the lowest glycine/taurine ratio and hydrophobicity index. HAR also developed the fewest cholesterol gallstones (23%), while 64% of CHR and 58% of BIO hamsters had cholesterol gallstones and 34% of BIO hamsters developed pigment stones. Doubling dietary cholesterol from 0.4 to 0.8% doubled the incidence of cholesterol gallstones but exerted minimal impact on other parameters compared to strain differences. Thus, different strains of hamsters vary considerably with respect to biliary cholesterol, bile acid profile and formation of cholesterol gallstones associated with differences in plasma lipoprotein profiles.

The patB gene product, required for growth of the cyanobacterium Anabaena sp. strain PCC 7120 under nitrogen-limiting conditions, contains ferredoxin and helix-turn-helix domains

A mutant of Anabaena sp. strain PCC 7120, called PAT-2, that grows poorly under nitrogen-fixing conditions, has been isolated. The heterocysts of the mutant strain develop much more slowly than those of the wild type and are spaced more closely in an older culture of the mutant than in the wild type. The wild-type gene that complements the mutation in PAT-2, called patB, was isolated and characterized. The predicted 529-amino-acid PatB protein contains a region very similar to the Fe4S4 bacterial-type ferredoxins near its N terminus and a helix-turn-helix motif near its C terminus. This pattern of domains resembles those of transcriptional regulators in both prokaryotes and eukaryotes. The mutation in strain PAT-2 is the deletion of G at nucleotide 1342 in the patB gene, resulting in the loss of a 62-amino-acid fragment from the C terminus of the PatB protein, including the helix-turn-helix motif.

Stable heparin-producing cell lines derived from the Furth murine mastocytoma

Stable cell lines that synthesize heparin have been established from the Furth murine mastocytoma. The parental line (MST) divides in suspension every 14-18 h in growth medium supplemented with fetal bovine serum or defined growth factors. Adherent subclones were selected by adhesion to plastic culture vessels. Both adherent and nonadherent cells contain about 0.4 micrograms of glycosaminoglycan hexuronic acid per 10(6) cells, composed of 80% heparin and 20% chondroitin sulfate E. Deaminative cleavage of MST heparin by HNO2 at pH 1.5 released disaccharides that were similar in composition to those obtained from commercial heparin, except that disaccharides containing 3,6-O-desulfated GlcN units were not found. Greater than 90% of the glycosaminoglycans were stored in cytoplasmic granules, and challenge of the cells with dinitrophenylated bovine serum albumin and anti-dinitrophenyl IgE released a portion of the stored material. Growth studies of subclones showed that MST cells tolerate a 10-fold variation in glycosaminoglycan content. Incubation of cells with sodium chlorate reduced glycosaminoglycan sulfation by > 95% without affecting cell growth. Thus, granule glycosaminoglycans appear to be nonessential for growth of MST cells.

[A software design for standard grayscale printout of China-made automatic static quantitative TBC visual field analyser]

A method of "TBC GRAPH" software design for standard grayscale printout of TBC static quantitative perimetry is introduced. The software is operated in IBM PC/XT or PC/AT compatible computer, using Chinese Character Disk Operating System (CCDOS) which has widespread users in China. Symbols were established by using CCDOS word--make function, and sectoral as well as symbolic matrix were made, which realized the standard grayscale printout. The software is recommended for use in ophthalmic clinic and education.

Social support among the aged in Wuhan, China

"This study provides information on supportive social relations in a sample of 2,762 elderly people in Wuhan, China. The elderly concerned were found to be actively engaged in exchanges of social support with their families and kin. They not only receive assistance but also provide a substantial amount of help to others. These supportive ties were highly positive and satisfactory to the great majority of the respondents. Only moderate correlations were found among various dimensions of social support. These results underscore the multi-dimensional nature of social support and suggest that caution needs to be exercised in extrapolating interpersonal exchanges from social embeddedness."

The spectral VEP in normal subjects and dichromats

The spectral VEP in 13 normal subjects (25 eyes), four cases (8 eyes) of protanopes and 8 cases (15 eyes) of deuteranopes were tested. In normal subjects, the shortest latencies of N1, P1, N2 were in 560 nm and the greatest amplitudes of N1-P1 and P1-N2 were 560-570 nm, around which the latencies were delayed and the amplitudes were decreased as the wavelengths of stimulative light increased or decreased gradually. The spectral VEP pattern of deuteranopes was similar to the normal subjects. In the protanopes, the shorter latencies of N1,P1,N2 and greater amplitudes of N1-P1, P1-N2 appeared in 520-530 nm and 570 nm, forming the two-thoughs and two-peaks shapes, with the shortest latencies and the greatest amplitudes in 520-530 nm. There were statistically significant differences of amplitudes and/or latencies in some wavelengths between the protanopes and normals and between the deuteranopes and normals.

Quantitative evaluation of flicker ERG waveforms in low vision patients

Flicker electroretinograms (FERGs) of 30Hz were recorded for 46 eyes (23 cases) of low vision, including 38 eyes with retinal diseases and 8 eyes with optic neuropathy, and for 39 normal eyes (33 cases). The recorded wave forms were analysed by two methods: (1) to measure the peak to peak amplitude and pseudophase directly, and (2) to measure the amplitude and phase of fundamental response component (30Hz) by discrete Fourier transform (DFT). The abnormality ratios between these two methods were compared in low vision patients. All the eyes with optic neuropathy showed normal flicker ERG, the abnormality ratios of directly measured amplitude and the amplitude by DFT were 60.9% in 28 eyes and 71.7% in 33 eyes with retinal diseases respectively, the difference being no statistically significant (P > 0.05), while the abnormality ratios of directly measured pseudo-phase and the phase by DFT were 60.9% in 28 eyes and 82.6% in 38 eyes with retinal diseases respectively, the difference being statistically significant (P < 0.05). These results suggest that FERGs are an objective way to test the retinal function, and DFT for flicker ERGs are more useful in quantitative evaluation of the retinal function.

The structure of the Mental Health Inventory among Chinese in Taiwan

This study attempted to ascertain the construct validity and external validity of the Mental Health Inventory in a Chinese population in Taiwan and contrast these results with results obtained from studies of several U.S. populations. In particular, a series of measurement models were specified and evaluated to address the issues of reliability and validity. Data were collected from personal interviews of a probability sample of 1,194 Chinese respondents 14 years of age and older in four townships in southwest Taiwan. The Mental Health Inventory was found to involve two major components: positive well-being and psychological distress. As a hierarchical structure, each component consists of one second-order and two or three first-order factors. The relationships between well-being and distress can be characterized as substantially independent and modestly bipolar depending on the level and specification.

Impact of self-management education on the functional health status of older adults with heart disease

This paper presents findings from the evaluation of a self-management education program based on self-regulation principles. Older men and women (N = 324) were randomly assigned to program and control groups. Outcomes were measured using the Sickness Impact Profile. Twelve months following baseline data collection, psychosocial functioning of program participants was significantly better than that of controls. Different program effects were noted when results were analyzed by participant gender.

The patA gene product, which contains a region similar to CheY of Escherichia coli, controls heterocyst pattern formation in the cyanobacterium Anabaena 7120

In Anabaena 7120, heterocysts (cells specialized for nitrogen fixation) develop at the ends of filaments and at intervals within each filament. We have isolated a mutant Anabaena strain that develops heterocysts mostly at the ends of filaments. This mutant, PAT-1, grows poorly under nitrogen-fixing conditions. The wild-type gene that complements the mutation in PAT-1, called patA, was cloned and sequenced. The predicted PatA protein contains 379 amino acids distributed among three "domains" based on predictions of hydropathy and flexibility. The carboxyl-terminal domain is very similar to that of CheY and other response regulators in two-component regulatory systems in eubacteria. The patA mutation suppresses the multiheterocyst phenotype produced by extra copies of the wild-type hetR gene described previously, suggesting that PatA and HetR are components of the same environment-sensing regulatory circuit in Anabaena.

Characterization of a non-tissue-specific, 3',5'-cyclic adenosine monophosphate-responsive element in the proximal region of the rat prolactin gene

The nature of a DNA element located in the -100 to -85 region of the rat PRL gene has been characterized. Previous studies demonstrated that this region may contribute to basal and hormonally regulated expression of the PRL gene. As this region contains a sequence with similarity to a consensus cAMP-responsive element (CRE), a possible role for the cAMP response element binding protein (CREB) has been explored. A point mutation which made the PRL CRE-like sequence less like a consensus CRE had little effect on basal or cAMP-stimulated expression of a PRL-luciferase reporter gene. DNase footprint studies demonstrated that the proximal region of the PRL gene does not contain a high affinity CREB binding site. Mobility shift experiments demonstrated that the major GH3 nuclear protein which interacts with the -100 to -85 region of the PRL gene in vitro is not CREB. Transfection of a dominant inhibitor of CREB action had little or no effect on expression of an indicator gene containing the PRL proximal region. Thus, the PRL proximal region does not contain a high affinity CREB binding site, and it is unlikely that CREB plays a major role in expression of the PRL gene. The functional capabilities of the -100 to -85 region of the PRL gene were then tested in a transfection assay. Synthetic multimers of this region were found to be sufficient to permit a transcriptional response to cAMP or TRH in GH3 cells and cAMP in Rat-1 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Mössbauer study of the native, reduced and substrate-reacted Desulfovibrio gigas aldehyde oxido-reductase

The Desulfovibrio gigas aldehyde-oxido-reductase contains molybdenum and iron-sulfur clusters. Mössbauer spectroscopy was used to characterize the iron-sulfur clusters. Spectra of the enzyme in its oxidized, partially reduced and benzaldehyde-reacted states were recorded at different temperatures and applied magnetic fields. All the iron atoms in D. gigas aldehyde oxido-reductase are organized as [2Fe-2S] clusters. In the oxidized enzyme, the clusters are diamagnetic and exhibit a single quadrupole doublet with parameters (delta EQ = 0.62 +/- 0.02 mm/s and delta = 0.27 +/- 0.01 mm/s) typical for the [2Fe-2S]2+ state. Mössbauer spectra of the reduced clusters also show the characteristics of a [2Fe-2S]1+ cluster and can be explained by a spin-coupling model proposed for the [2Fe-2S] cluster where a high-spin ferrous ion (S = 2) is antiferromagnetically coupled to a high-spin ferric ion (S = 5/2) to form a S = 1/2 system. Two ferrous sites with different delta EQ values (3.42 mm/s and 2.93 mm/s at 85 K) are observed for the reduced enzyme, indicating the presence of two types of [2Fe-2S] clusters in the D. gigas enzyme. Taking this observation together with the re-evaluated value of iron content (3.5 +/- 0.1 Fe/molecule), it is concluded that, similar to other Mo-hydroxylases, the D. gigas aldehyde oxido-reductase also contains two spectroscopically distinguishable [2Fe-2S] clusters.

[The variations of PRL, LH, FSH and testosterone in renal disease]

Blood PRL was measured with RIA in 22 males and 19 females with various degrees of renal insufficiency. At the same time, blood LH, FSH, testosterone were studied in all the male patients and 20 sex-age matched healthy subjects. The results showed that the levels of PRL and LH were increased, and the level of testosterone was decreased significantly in male uremic patients. There was a significant negative correlation between PRL and testosterone. All the above parameters were measured again 8-25 days after continuous ambulatory peritoneal dialysis (CAPD) therapy in 5 male uremic patients. The BUN and Cr levels decreased and the clinical manifestations of uremia improved, but the levels of PRL, LH, FSH and testosterone showed no significant changes. The mechanisms of these variations were discussed.