Directed movement of chromosome arms and fragments in mitotic newt lung cells using optical scissors and optical tweezers

A pulsed-laser microbeam at 532 nm wavelength (optical scissors) and a laser-induced optical trap at 1064 nm wavelength (optical tweezers) have been successively combined to dissect and manipulate chromosomes in live newt lung epithelial cells. These preliminary experimental results demonstrated that chromosome fragments dissected by laser microbeam surgery, regardless of their size, could be easily pulled or rotated by optical forces when positioned at the periphery of the mitotic spindle. In addition, chromosome arms which were not subjected to laser microsurgery also could be moved with the optical tweezers at the spindle periphery. In our previous study on rat kangaroo kidney cells (PTK2), this degree of facilty in manipulating chromosome movement was not possible, most likely due to the close proximity of the intermediate filament "cage" to the spindle. It is concluded herein that optical scissors and tweezers can be used in combination to study the interaction of chromosomes with the mitotic spindle in cells where the peripheral regions of the spindle are unobstructed by intermediate filaments. This can be performed on newt cells, where the diameter of the cage can be substantially larger than the diameter of the spindle.

[Pulmonary melioidosis. Report of 4 cases and literature reviewed]

In this report, We present 4 patients with pulmonary melioidosis. The literatures on epidemiology, clinical manifestation, roentogenology, diagnosis and therapeutics of melioidosis are reviewed.

[The effect of astragalus polysaccharides (APS) on cell mediated immunity (CMI) in burned mice]

In this paper, the changes in CMI in mice were determined after burn injury, and the effects of APS on CMI of burned mice were investigated in vivo. The results showed that on day 6 postburn, spleen index and thymus index were reduced, T lymphocyte transformation and interleukin 2 (IL-2) production were suppressed. Furthermore, the serum and macrophages from burned mice showed significant suppressive activity upon T lymphocyte transformation in vitro, and suppressive index (SI) of suppressor T cell (Ts) was greater than that of normal controls. Intraperitoneal administration of APS (250mg/kg daily, from day 0 to 5 could restore spleen index and thymus index of burned mice, reverse the suppression of T lymphocyte transformation and IL-2 production, reduce remarkably the suppressive activity of serum, macrophages and Ts. It is suggested that (1) burn injury-induced suppression of CMI may be related to the augmented suppressive activity of serum, macrophages and Ts; (2) administration of APS may restore the impaired CMI after burn injury by reducing the suppressive activity of postburn serum, macrophages and Ts.

[Reproducibility of a self-administered questionnaire for dietary habits, smoking, and drinking]

Reproducibility of results from a self-administered questionnaire on dietary habits (the frequency of taking various foods and eating habits), smoking and drinking was examined to study the reliability of the questionnaire, stability of lifestyle, and the validity of the questionnaire in assessing lifestyle as a risk factor in chronic diseases. The study sample included 120 males and 173 females in a rural town in Kyoto Prefecture, who participated in a series of three health examinations in 1988, 1989, and 1992. A survey using the same questionnaire was performed before each health examination. Reproducibility was assessed by correlation (Spearman's rank correlation coefficient or kappa coefficient), exact agreement of category answered, and comparison of mean frequency. An attempt was made to separate reliability and stability from reproducibility using the data from the questionnaire obtained in the three years. Good reproducibility for one-year and four-year intervals was found for foods taken habitually or often (boiled rice, cooked rice gruel with tea, milk, coffee, fruits and bread), and habits (eating breakfast, some eating habits, smoking and drinking). The same was also found for cigarette or alcohol consumption among current consumers except that cigarette consumption over a four-year interval was more likely to change. The reliability of the questionnaire and stability of these items were considered satisfactory, suggesting that the questionnaire was a valid method of assessing long-term lifestyle. Poor reproducibility of results regarding consumption of green-yellow and other vegetables indicated both poor reliability and a change in consumption over four years, and suggested poor validity. However, disagreement in more than one category of vegetables was not large and misclassification in assessing them as risk factors and changes in frequency of consumption may not be large either. Although correlation coefficients for the items of dairy food and eating snacks were fair, disagreement in more than one category was relatively large which may have caused misclassification. The mean frequency of consumption of pickles and fishpaste, ham or sausage significantly decreased over the four year interval. This may reflect the influence of health education on reducing salt intake.

[Burden of cigarette smoking on medical costs paid by national health insurance in a rural town]

This study examined the direct association between medical costs and cigarette smoking and modification of interest in visiting medical facilities. The study sample consisted of 966 males 30 years of age or older in a rural town in Kyoto Prefecture, who were members of the National Health Insurance. The subjects were respondents to a previous questionnaire about smoking in February, 1989. There were 544 current smokers, 226 ex-smokers and 141 nonsmokers. Fifty-five subjects did not answer the question about smoking habits. Outpatient medical costs paid by National Health Insurance for the fiscal year 1989 were analyzed. Average medical costs of ex-smokers were the highest of all groups-current, ex-, and non-smokers (30-49, 50-69, and 70+ years of age). Those of current smokers and of the combined current or ex-smokers group were higher than those of non-smokers (30-49 and 50-69 years of age). None of these differences were significant by nonparametric test. The effect of smoking on medical costs was evaluated by odds ratio of the largest class of costs (50,000+ yen for 30-49 years of age, 200,000+ yen for 50-69 years of age, and 500,000+ yen for 70+ years of age) for various types of smokers compared with non-smokers by logistic regression. The odds ratios of current, ex-, and current or ex-smokers 30-49 and 50-69 years of age were between 2 to 3, but not significant. The odds ratio of subjects 70 years of age or older was smaller than unity and not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis and characterization of anti-idiotypic anti-T4 antibodies

We injected rabbits with purified monoclonal murine immunoglobulin (IgG1) or polyclonal antithyroxine antibodies (anti-T4) and polyclonal anti-triiodothyroacetic acid (anti-Triac) antibodies to stimulate the production of anti-idiotypic antibodies. Purified immunoglobulins from all five rabbits immunized with monoclonal primary antibodies were able to inhibit the interaction between [125I]T4 and the primary antibody. The preimmune sera were inactive. This effect was not due to endogenous T4 contamination or contamination with the injected primary antibody. Half-maximal inhibition of binding of primary antibody with anti-idiotype was between 1.6 and 30 micrograms of total immunoglobulins. Addition of normal mouse IgG1 did not alter the inhibitory effect of the anti-idiotypic antibody, suggesting that this effect is specific. These anti-idiotypic antibodies reacted differently with different polyclonal antibodies, reflecting the heterogeneous nature of polyclonal antibody populations. Polyclonal antibodies were less effective in stimulating anti-idiotypic antibody production. One polyclonal anti-T4 and one anti-Triac antibody produced weak anti-idiotypic antibody that had to be used at a concentration of > 600 micrograms of total immunoglobulins to be inhibitory. Both inhibited the binding of T4 to the monoclonal anti-T4 antibody. However, they were ineffective in inhibiting the function of their own antigen, the polyclonal anti-T4 or anti-Triac antibody. We tested the most potent anti-idiotypic antibodies for their ability to compete with T4 for other T4-binding proteins. Specific inhibition of T4 binding to thyroid-binding globulin was observed with half-maximal effect at approximately 450 micrograms of total IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular modelling of the inclusion complexes between beta-cyclodextrin and (R)/(S)-methylphenobarbitone and its application to HPLC

Molecular modelling of beta-cyclodextrin and optimisation of its potential energy suggests that a favoured conformation is that distorted from a symmetrical torus. The inclusion of water molecules into the torus cavity simulates the increased stability in an aqueous solvent. Complexes of beta-cyclodextrin with (R)- and (S)-enantiomers of methylphenobarbitone have been modelled and energetically optimised by the application of molecular mechanics. The simulations suggests that the guest molecules adopt an orientation in which the phenyl ring is projected into the torus cavity, with in each case the plane of the ring parallel to a longer axis of the distorted torus and slightly displaced from the axis through the torus cavity. It is suggested that the asymmetry in the macrocyclic ring contributes to chiral recognition as a result of additional discriminatory binding to the barbiturate ring residue of each enantiomer, which occupy different 3D geometries. The enantiomers form complexes of different minimum potential energies. The resulting difference in complex stability can be related to the behaviour of beta-cyclodextrin, as a mobile phase additive in reverse-phase HPLC to effect chiral separation of rac-methylphenobarbitone during chromatography.

Comparison of Fo extraction methods for high-precision voice perturbation measurements

Voice perturbation measures, such as jitter and shimmer, depend on accurate extraction of fundamental frequency (Fo) and amplitude of various waveform types. The extraction method directly affects the accuracy of the measures, particularly if several waveform types (with or without formant structure) are under consideration and if noise and modulation are present in the signal. For frequency perturbation, high precision is defined here as the ability to extract Fo to +/- 0.01% under conditions of noise and modulation. Three Fo-extraction methods and their software implementations are discussed and compared. The methods are cycle-to-cycle waveform matching, zero-crossing and peak-picking. Interpolation between samples is added to make the extractions more accurate and reliable. The sensitivity of the methods to different parameters such as sampling frequency, mean Fo, signal-to-noise ratio, frequency modulation, and amplitude modulation are explored.

Inhibition by genistein of prolactin-induced Nb2 lymphoma cell mitogenesis

Tyrosine kinase activation in mediating the mitogenic action of prolactin (PRL) has been evaluated. Use was made of genistein, a tyrosine kinase antagonist, and cultured rat Nb2 lymphoma cells, i.e. the lactogen-dependent Nb2-11 line and a lactogen-independent subline, Nb2-SFJCD1. Genistein was found to be a potent growth-inhibitor for both lines, inhibiting 3H-thymidine incorporation in Nb2-11 and Nb2-SFJCD1 cells with IC50s of 4.2 and 6.7 micrograms/ml, respectively. Genistein also inhibited expression and translation of the heat shock protein 70 gene and pp40 protein substrate phosphorylation which, in Nb2-11 cells, followed PRL addition within minutes. Genistein inhibition of DNA synthesis in G1-arrested Nb2-11 cells was most pronounced if the agent was added within 1 h of PRL treatment. The results indicate that, while both Nb2 cell lines have a general growth requirement for tyrosyl phosphorylation, the early, PRL-induced tyrosine kinase activation is a component of the PRL mitogenic signal transduction pathway.

[The effect on longevity of blood pressure and body mass index in a community of Kyoto]

To assess the combined influence of blood pressure and body mass index (BMI) on death from all-cause and circulatory diseases, a retrospective cohort study was performed in a community of Kyoto from 1978 to 1991. Between 1978 and 1982, 1,629 people (650 men and 979 women) aged 40-69 years, representing 76.6% of this age group in the community, were screened for entry into this study. A total of 134 deaths were observed and death by circulatory diseases was 36.6% of the all-cause deaths. The survival rate, calculated by the Kaplan-Meier method, was higher among normotensives [systolic blood pressure (SBP) < 140 mmHg and diastolic blood pressure (DBP) < 90] compared to borderline hypertensives (SBP = 140-159 and/or DBP = 90-94) and hypertensives (SBP > = 160 or DBP > = 95, or using antihypertensive medication) for subjects aged 50-69 years both males and females. The hazard ratio of all-cause and circulatory disease mortality for sex, age, blood pressure and BMI as covariables was estimated from the Cox proportional hazard model. The hazard ratio (95% confidence interval) was greater for circulatory disease mortality [2.76 (1.37-5.75) for borderline hypertensive and 2.53 (1.21-5.26) for hypertensive] than for all-cause mortality [1.86 (1.22-2.84) for borderline hypertensive and 2.03 (1.32-3.10) for hypertensive]. These results indicate that hypertension increases risk of circulatory disease mortality and decreases survival rate. While the effect of obesity was not as strong for circulatory disease mortality as blood pressure, an increase in hazard ratio with increasing BMI was suggested in this study.

[Association between participation in health check and visiting medical facilities in residents in a rural town]

Participants in a community secondary prevention action sponsored by the local government were compared with non-participants with respect to utilization of medical facilities for medical examinations. The study sample consisted of 1,013 males and 1,042 females aged 40 years or over, in a rural town in Kyoto prefecture, who were members of the National Health Insurance. Data from National Health Insurance records, such as date of consultation and type of medical examinations, were analyzed. The secondary prevention action sponsored by the town consisted of a multiphasic health check for circulatory or other chronic diseases, and screenings for tuberculosis and cancers of the stomach, lung, breast and cervix. Medical examinations included urine test, blood cell count, electrocardiography, laboratory tests for serum transaminases, serum glucose, and fecal occult blood, X-ray or endoscopy of the stomach, chest X-ray, mammography, and cervical cytology. Results of the study showed that those who attended the town sponsored secondary prevention action were more likely to utilize local medical facilities, and those who did not participate were likely to visit facilities outside the town. Medical facilities, both local and outside the town, had a larger proportion of examinations corresponding to health examinations or stomach cancer screening than the town office, however, the town office had a larger proportion of lung or cervical cancer screening. The health examination and stomach cancer screening in the town office, and in the medical facilities appeared to be redundant while lung and cervical cancer screening were complemented tests at medical facilities. When these examinations are targeted as modifying factors in the natural history of diseases, consideration should be given to both the records of secondary prevention actions as well as medical records of other medical facilities that may be utilized.

[Comparison of a rural town and a fishing town: diet and circulatory system diseases]

We report a comparative study of the Standardized Mortality Ratio (SMR) for circulatory system diseases and diet in a rural town and a fishing town in Kyoto Prefecture. SMR was assessed during the 5-year period from 1983 through 1987, and compared with the standard age- and sex-adjusted demographic and mortality statistics compiled by the National Census Bureau of Japan in 1985. A food frequency questionnaire in which the respondents evaluated their food consumption during the previous 1-year period was used to assess diet. The questionnaire was administered during February 1989 in the rural town and during February 1990 in the fishing town. In comparison with the standard statistics, SMR was higher in the rural town and lower in the fishing town. The inhabitants of the fishing town more frequently consumed low-fat and low-sodium foods, such as fish, potatoes, tofu, and green, yellow and other vegetables, and less frequently consumed high-fat and high-sodium foods, such as meat, fried food, pickles, than did the inhabitants of the rural town. The residents of the fishing town also consumed a greater variety of foods in one week. The two towns differ in geography and economic structure, and their inhabitants have different life-styles and eating habits. The lower SMR for circulatory system diseases in the fishing town may be related to the greater consumption of fish and vegetables with lower meat and salt intake, as well as the balanced of diet.

Genetic fusion of subunits of a dimeric protein substantially enhances its stability and rate of folding

The gene V protein of bacteriophage f1 is a single-stranded DNA and RNA-binding protein composed of two identical subunits. We have constructed single-chain variants of the protein using short peptide linkers of five or six amino acids to connect the carboxyl terminus of one monomer to the amino terminus of the second monomer. The resulting subunit-fusion gene V proteins were found to bind single-stranded DNA nearly as tightly as the wild-type protein. Denaturation measurements show that the subunit-fusion gene V proteins are 5 kcal/mol (1 kcal = 4.18 kJ) more stable than the wild-type protein at a protein concentration of 10 microM. The rate of unfolding of the protein is essentially unaffected by the fusion of monomeric subunits, whereas the rate of folding is greatly enhanced. Our results suggest a simple way of obtaining a substantial thermodynamic stabilization for some oligomeric proteins.

Comparison of the metabolic and endocrine effects of 3,5,3'-triiodothyroacetic acid and thyroxine

To test the hypothesis that 3,5,3'-triiodothyroacetic acid (Triac) is more active as a TSH suppressor than on peripheral parameters of thyroid hormone action, the following parameters were studied: basal metabolic rate, sleeping energy expenditure (SEE), sex hormone-binding globulin, and cholesterol. In a double blind trial, 14 subjects received during 3 weeks (phase 1) 180 micrograms T4 or 1700 micrograms Triac daily, divided into 3 doses, to suppress thyroidal secretion. The dosage was doubled for the next 3 weeks (phase 2). Under T4 treatment, TSH reached 0.11 mU/L during phase 1 and less than 0.03 mU/L during phase 2. With Triac, a marked TSH inhibition occurred after 1 week (0.17 mU/L), followed by an escape during the following 2 weeks (0.63 mU/L). During phase 2, an almost complete TSH suppression was obtained (0.03 mU/L). Both Triac doses suppressed endogenous thyroid hormone secretion, as evidenced by T4 and rT3 levels. Both substances induced a 2-fold stimulation of sex hormone-binding globulin during phase 2. Serum cholesterol decreased similarly, without affecting the high/low density lipoprotein ratio. T4 increased SEE by 4.1% and 8.5% during phases 1 and 2. Triac failed to induce the expected peripheral metabolic responses of the thyroid hormones, as demonstrated by an unchanged SEE and basal metabolic rate. These results clearly show a preferential action of Triac on TSH suppression.

Effect of the antioxidant TK 12627 (Irganox) on monodeiodination and on the levels of messenger ribonucleic acid of 5'-deiodinase type I and spot 14

Until now, most potent inhibitors of monodeiodination are iodinated, propylthiouracil being an exception. We report here studies on a new non-iodinated substance, triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methyl-phenyl) propionate (TK 12627 or Irganox), which is used as a very efficient antioxidant in the chemistry of plastics. The studies were performed with 23 hypothyroid rats that received Irganox in their daily food (8 mg.day-1 x (100 g body wt)-1) for 3 weeks. Thyroxine (T4) metabolism was studied by implanting minipumps delivering 2.3 nmol T4.day-1 x (100 g body wt)-1 for 1 week. On day 1 before sacrifice, another minipump containing [125I]-3,5,3'-triiodothyronine (T3, 2.6 microCi/day) and [131I]-3,3',5'-triiodothyronine (rT3, 2.1 microCi/day) was implanted. The results showed that with Irganox treatment serum T4 concentrations were higher (p < 0.05). Serum T3 concentrations markedly decreased (1.07 +/- 0.07 vs 0.65 +/- 0.04 nmol/l), accompanied by a decrease of free T3 concentrations (p < 0.001). Serum rT3 concentrations increased by 50% (p < 0.001). Serum thyrotropin levels were mostly unmeasurable. The plasma clearance rate decreased slightly for T4 (19%, p < 0.05) and remarkably for rT3 (46.7%, p < 0.001). The conversion rate of T4 to rT3 did not change. Deiodinase type I (5'D-I) activity decreased in both liver and kidney tissues by 54% and 52%, respectively, and correlated with T3 (r2 = 0.79 and 0.65, respectively). Brain deiodinase type III (5D-III) was unchanged and type II (5'D-II) was unmeasurable.(ABSTRACT TRUNCATED AT 250 WORDS)

Astral and spindle forces in PtK2 cells during anaphase B: a laser microbeam study

Rat kangaroo kidney epithelium (PtK2) cells develop prominent asters and spindles during anaphase B of mitosis. It has been shown that severing the spindle at early anaphase B in living PtK1 cells results in a dramatic increase in the rate of pole-pole separation. This result suggested that the asters pull on the spindle poles, putting tension on the spindle, while the spindle acts as a governor, limiting the rate of pole separation. To further test these inferences, we used a UV-laser microbeam to damage one of the two asters in living PtK2 cells at early anaphase B and monitored the effects on individual spindle pole movements, pole-pole separation rates and astral microtubules (MTs). Irradiation at the estimated position of a centrosome greatly reduced its array of astral MTs and nearly stopped the movement of the irradiated pole, whereas the sister pole retained its normal array of astral MTs and actually accelerated. Control irradiations, either close to the estimated position of the centrosome or beside the spindle at the equator, had little or no effect on either spindle pole movements or astral MTs. These results support the inferences that during anaphase B in living PtK cells, the central spindle is under tension generated by pulling forces in the asters (presumably MT-mediated) and that the spindle generates counterforces that limit the rate of pole separation. The results also suggest that the central spindle in living PtK cells may be able to generate a pushing force.

Equilibrium denaturation of recombinant human FK binding protein in urea

The equilibrium folding behavior of recombinant human FK-binding protein, a peptidyl-prolyl cis-trans-isomerase, was examined by urea-induced denaturation using probes of protein structure including intrinsic tryptophan fluorescence, second-derivative UV absorbance, CD, and NMR. All optical probes of protein structure indicate that FKBP is capable of folding reversibly. The second-derivative UV absorbance and CD probes of the structure exhibited urea denaturation transitions at approximately 4.3 M urea. The fluorescence of the single protein tryptophan is quenched in the folded state. During the unfolding-folding transition, the unquenching of tryptophan fluorescence occurs at a slightly lower urea concentration (3.9 M urea) than the changes observed for the other optical probes of folding. These probes of structure demonstrate little dependence on protein concentration in the range of 0.2- approximately 3 mg/mL across the urea-induced denaturation transition. The reversibility of the unfolding-folding transition was confirmed from two-dimensional 15N/1H heteronuclear single-quantum coherence (HSQC) spectra of [U-15N]FKBP. In addition, the native-denatured transitions for 57 individual amino acids were determined from an analysis of these spectra acquired at different urea concentrations. Analysis of the transitions for all clearly observable HSQC cross peaks for residues distributed throughout the protein and comparison to the optical folding transitions, indicate that FKBP global folding is consistent with a two-state process. Although direct measurement of FKBP catalytic activity in urea was complex, enzyme activity was observed up to the beginning of the FKBP urea-denaturation transition.(ABSTRACT TRUNCATED AT 250 WORDS)

[A discussion of jaws relation in complete denture restoration]

We studied jaws relation of 8 edentulous patients after complete denture restoration by using Digital Sirognathograph (D-SGG).The results indicated that the maximum intercuspation occlusion (i.e.CO or MCP) is not commonly coincident with the CRO,and the discrepancy is statistically significant.The CO is anterior to the CRO by 0.72+/-0.39mm,and it may vary significantly in different closures of the same patient. This implies that the termination of the occlusion with neuromusculature is not strictly precise and constant,but alters in a corresponding range.So,it seems reasonable to develop a "freedom of centric" in the range of 0.72+/-0.39mm anterior to the CRO.The physiological functional occlusion,therefore,is restricted to neither of the CO nor the CRO, but is guided between the two.

Optical trapping for chromosome manipulation: a wavelength dependence of induced chromosome bridges

Using a tunable titanium-sapphire laser, we have compared different wavelengths (from 700 to 840 nm) for their utility in optical trapping of chromosomes in mitotic rat kangaroo Potorous tridactylus (PtK2) cells. It was found that irradiation with a near-infrared light induces the sticking together of chromosome shoulders. The attached chromatids failed to separate, or separated with significant delay and formed a chromosome bridge during anaphase. Using this bridge (and induced c-mitosis) as a reference, we compared the action of different wavelengths (from 700 to 840 nm). Chromosomes were irradiated at metaphase and the cells were observed until the end of cytokinesis. Chromosomes were irradiated for different periods of time, using 130 mW of power at the objective focal plane. The biological responses observed after optical trapping were: (1) normal cell division, (2) formation of a temporary chromosome bridge, (3) formation of a permanent chromosome bridge, (4) complete blockage of chromosome separation (c-mitosis). The chromosomes were found to have a maximal sensitivity to 760-765 nm light and minimal sensitivity to 700 and 800-820 nm light. Cells with chromosomes irradiated for a long time, using wavelength 760-765 nm, generally were incapable of going through anaphase and remained in c-mitosis. We conclude that the optimal wavelengths for optical trapping are 700 and 800-820 nm.

Micromanipulation of chromosomes in PTK2 cells using laser microsurgery (optical scalpel) in combination with laser-induced optical force (optical tweezers)

An optical scalpel and optical tweezer have been combined to perform intracellular microsurgery and micromanipulation in vivo. When only laser microsurgery was performed on metaphase chromosomes, the dissected sister chromatid fragments drifted off to either the side of the spindle or completely off the spindle. At anaphase the fragments separated and the two arms generally moved to their respective daughter cells. When the chromosome arm was cut during anaphase A and B, the distal chromosome fragment separated from the rest of the chromosome and moved toward the pole, following the proximal chromosome fragment. Distal chromosome fragments laser-dissected during metaphase were held together throughout anaphase using the optical trap. Optical trapping of dissected chromosome fragments during anaphase A and B inhibited movement of the chromosome fragment to its pole. As a result, the trapped chromosome fragments were (1) incorporated into the opposite daughter cell, (2) lost in the cleavage furrow during cytokinesis, or (3) eventually incorporated into the correct daughter cell. These results indicate that optical traps are effective in holding laser-dissected chromosome fragments throughout mitosis. This new tool should be useful for studies on chromosome movement and cell genetics.

Roles of multiple glucose transporters in Saccharomyces cerevisiae

In Saccharomyces cerevisiae, TRK1 and TRK2 are required for high- and low-affinity K+ transport. Among suppressors of the K+ transport defect in trk1 delta trk2 delta cells, we have identified members of the sugar transporter gene superfamily. One suppressor encodes the previously identified glucose transporter HXT1, and another encodes a new member of this family, HXT3. The inferred amino acid sequence of HXT3 is 87% identical to that of HXT1, 64% identical to that of HXT2, and 32% identical to that of SNF3. Like HXT1 and HXT2, overexpression of HXT3 in snf3 delta cells confers growth on low-glucose or raffinose media. The function of another new member of the HXT superfamily, HXT4 (previously identified by its ability to suppress the snf3 delta phenotype; L. Bisson, personal communication), was revealed in experiments that deleted all possible combinations of the five members of the glucose transporter gene family. Neither SNF3, HXT1, HXT2, HXT3, nor HXT4 is essential for viability. snf3 delta hxt1 delta hxt2 delta hxt3 delta hxt4 delta cells are unable to grow on media containing high concentrations of glucose (5%) but can grow on low-glucose (0.5%) media, revealing the presence of a sixth transporter that is itself glucose repressible. This transporter may be negatively regulated by SNF3 since expression of SNF3 abolishes growth of hxt1 delta hxt2 delta hxt3 delta hxt4 delta cells on low-glucose medium. HXT1, HXT2, HXT3, and HXT4 can function independently: expression of any one of these genes is sufficient to confer growth on medium containing at least 1% glucose. A synergistic relationship between SNF3 and each of the HXT genes is suggested by the observation that SNF2 hxt1 delta hxt2 delta hxt3 delta hxt4 delta cells and snf3 delta HXT1 HXT2 HXT3 HXT4 cells are unable to grow on raffinose (low fructose) yet SNF3 in combination with any single HXT gene is sufficient for growth on raffinose. HXT1 and HXT3 are differentially regulated. HXT1::lacZ is maximally expressed during exponential growth whereas HXT3::lacZ is maximally expressed after entry into stationary phase.

[Clinical and experimental study on its regulatory function of yi xin decoction (heart-nourishing decoction) to lipids metabolic disturbance in coronary heart disease]

In this research, 74 patients with coronary heart disease (CHD) were grouped in matched-pair, one group took orally Inositol and Mai Tong as the control group, the other group took orally Yi Xin Decoction as the tested group. Indices, i. e. serum levels of apolipoprotein A-1 (Apo A-1), apolipoprotein B (Apo-B), high density lipoprotein cholesterol (HDL-c), high density lipoprotein subcomponent cholesterol (HDL2-c), B-lipoprotein (B-LP), total cholesterol (Tch), triglyceride (TG) were measured before and after treatment for 28 days; the results showed that the patients with CHD have prominent derangement of lipid metabolism, which is similar to previous reports. Yi Xin Decoction modified according to Syndrome Differentiation, produced the effect of decreasing the serum Apo-B levels and TG. It also increased Apo-A-1, HDL-c and HDL2-c respectively. Moreover the effect of lowering Apo-B and raising HDL-c in the Yi Xin Decoction group was better than that in the control group. There was no side effect at all; all these indicated that Yi Xin Decoction has a remarkable function of regulating the disturbance of lipid metabolism in CHD patients. In order to further investigate the curative effect of Yi Xin Decoction and elucidate its mechanism, the authors have also investigated Yi Xin Decoction on the experimental mice with hyperlipemia. The result Showed that Tch and TG in atromid and Yi Xin Decoction group reduced after medication, P < 0.01. In comparing with control group, the HDL-c and acidic cholesterol in stool Yi Xin Decoction group rose, P < 0.05. The above study has provided reliable basis for the clinical application of Yi Xin Decoction and also a new medicine to regulate disturbance of lipid metabolism for CHD patients.

[Effect of mieyanling oral liquid on the immune responses in normal and cyclophosphamide treated mice]

It has been proved that Mieyanling in Vivo and in Vitro, can augment the lymphocyte transformation rate induced by PHA, Con-A or LPS in mice. The suppressed immune function caused by cyclophosphamide can also be significantly relieved by Mieyanling Oral Liquid.

Comparison of hematopoietic and immune recovery after autologous bone marrow or blood stem cell transplants

We studied hematopoietic and immune recovery in 40 subjects receiving autologous bone marrow (ABMT) or blood stem cell transplants (ABSCT). Supportive care, transplant-related morbidity, duration of hospitalization and cost were also considered. ABSCT was associated with more rapid recovery of all hematopoietic lineages than was ABMT. However, kinetics of immune recovery were similar between the groups. In the ABSCT group, there was a correlation between numbers of blood progenitor cells infused and the rate of hematopoietic recovery. The accelerated hematopoietic recovery following ABSCT correlated with less morbidity, fewer transfusions, briefer hospitalization and lower cost than ABMT.

Optical trapping in animal and fungal cells using a tunable, near-infrared titanium-sapphire laser

We have compared two different laser-induced optical light traps for their utility in moving organelles within living animal cells and walled fungal cells. The first trap employed a continuous wave neodymium-yttrium aluminum garnet (Nd-YAG) laser at a wavelength of 1.06 micron. A second trap was constructed using a titanium-sapphire laser tunable from 700 to 1000 nm. With the latter trap we were able to achieve much stronger traps with less laser power and without damage to either mitochondria or spindles. Chromosomes and nuclei were easily displaced, nucleoli were separated and moved far away from interphase nuclei, and Woronin bodies were removed from septa. In comparison, these manipulations were not possible with the Nd-YAG laser-induced trap. The optical force trap induced by the tunable titanium-sapphire laser should find wide application in experimental cell biology because the wavelength can be selected for maximization of force production and minimization of energy absorption which leads to unwanted cell damage.

Micromanipulation of mitotic chromosomes in PTK2 cells using laser-induced optical forces ("optical tweezers")

To study the potential use of optical forces to manipulate chromosome movement, we have used a Nd:YAG laser at a wavelength of 1.06 microns focused into a phase contrast microscope. Metaphase and anaphase chromosomes were exposed while being monitored by video microscopy. The results indicated that when optical forces were applied to late-moving metaphase chromosomes on the side closest to the nearest spindle pole, the trapped chromosomes initiated movement to the metaphase plate. The chromosome velocities were two to eight times the normal rate depending on the chromosome size, geometry, and trapping site. At the initiation of anaphase, a pair of chromatids could be held by the optical trap and kept motionless throughout anaphase while the other pairs of chromatids separated and moved to opposite spindle poles. As a result, the trapped chromosome either was incorporated into one of the daughter cells or was lost in the cleavage furrow, or the two chromatids eventually separated and moved to their respective daughter cells. If the trap was removed at the beginning of anaphase B, the chromosome moved back to the poles. Our experiments demonstrate that the laser-induced optical force trap is a potential new technique to study noninvasively the mitotic spindle of living cells.

Reversible denaturation of the gene V protein of bacteriophage f1

The guanidine hydrochloride (GuHCl)-induced denaturation of the gene V protein of bacteriophage f1 has been studied, using the chemical reactivity of a cysteine residue that is buried in the folded protein and the circular dichroism (CD) at 211 and 229 nm as measures of the fraction of polypeptide chains in the folded form. It is found that this dimeric protein unfolds in a single cooperative transition from a folded dimer to two unfolded monomers. A folded, monomeric form of the gene V protein was not detected at equilibrium. The kinetics of unfolding of the gene V protein in 3 M GuHCl and the refolding in 2 M GuHCl are also consistent with a transition between a folded dimer and two unfolded monomers. The GuHCl concentration dependence of the rates of folding and unfolding suggests that the transition state for folding is near the folded conformation.

New type of X-linked progressive muscular dystrophy involving shoulder girdle and back

A new type of X-linked muscular dystrophy is described in a family in which 7 men had boyhood onset of progressive dystrophy involving muscles of the shoulder and back but not the calves or face. The scapula-back muscles are affected, but the calf muscles are normal. All patients are still able to walk. The oldest patient is now 37 years old. The muscular dystrophy has been specified by electromyography, pathologic tissue microscopic examination, electron microscopic study, and elevated CK. This type of muscular dystrophy has not been reported previously.

[Rapid identification of Mycobacterium tuberculosis and other mycobacteria with Mycobacterium tuberculosis whole chromosomal DNA probe]

The dot-blots containing DNA isolated from nonmycobacterial and mycobacterial microorganisms were hybridized with 32P-labeled M. tuberculosis whole chromosomal DNA at the various temperatures. The probe did not cross-hybridize to DNA of nonmycobacterial microorganisms (E. coli, Plasmid pUC19, Nocardia asteriodes), nor with DNA from all mycobacteria tested except M. bovis BCG under the higher temperature conditions. Microorganisms could also be directly spotted and lysed on nitrocellulose filters and used for hybridization thus making this technique suitable for clinical diagnosis.

Effects of pulse length and pulse strength on transfection by electroporation

The relative importance of pulse field strength E and pulse length tau 1/2 (half decay time of an exponential decay pulse) on the stable transfection frequency for HeLa or HUT-78 cells was investigated. Cells were transfected with plasmids containing the promoter and drug resistant genes pRSVgpt or pRSVneo by electroporation. The stable transfection frequency was assayed using the marker rescue technique. The transfection frequency increases with increasing values of E tau 1/2. For a given pulse length, the transfection frequency is proportional to the power of the pulse (E2 tau 1/2). Pulses with half decay times of 2.2 to 4.6 ms appear to be more efficient than 0.275 to 0.31 ms for stable transfection of HeLa cells.

An estradiol-dependent protein from chicken liver binds single-stranded DNA and RNA

We have identified two estradiol-dependent single-stranded DNA binding proteins in the nucleus and cytoplasm of chicken hepatocytes that bind the sequence 5'TCACCTTCGCTATG3' in the first exon of the chicken vitellogenin gene. As judged by chromatography on heparin-Sepharose and by proteolytic clipping bandshift assay, the two proteins are different. Furthermore, they only bind to the oligonucleotide corresponding to the upper strand. Depurination and depyrimidination interference experiments with the cytoplasmic protein show that the bases CCTT-G are involved in the protein-DNA interaction. An RNA corresponding to the upper strand of the gene between nucleotide positions -73 and +53 competes for binding to the single-stranded DNA. UV cross-linking experiments performed with bromouridine-substituted single-stranded RNA reveal that an estradiol-dependent hepatocyte cytoplasmic protein with a Mr of 71,000 binds to the mRNA-like single-stranded RNA.

[The relationship between coronary artery stenosis and myocardial metabolism of oxygen demand in dogs]

In open chest dogs, a micrometer constrictor was used to produce three different coronary artery stenosis (AS) on left circumflex coronary artery, and hemodynamics, blood gas and coronary sinus pH, lactate were then measured. In mild coronary AS, resting coronary artery flow (CBF) did not decrease; but lactate increased. In critical coronary AS, CBF slightly decreased, MVO2 decreased and lactate increased. There was a decrease in CBF, O2 supply/consumption ratio, coronary sinus pH and an increase in oxygen extraction and lactate with severe coronary AS. The percent area stenosis (%AS) was highly correlated with O2 supply (r = -0.92), poorly correlated with MVO2 (r = -0.58) when it was higher than 75%.

Study on mechanism of micronucleoli formation by laser microirradiation

In the male rat kangaroo cell line PTK2, argon laser (514.5 nm) microirradiation of both nucleoli in interphase cells 30, 23, and 12 h before mitosis, and nucleoli in early prophase cells resulted in the formation of micronucleoli, i.e., several small nucleolus-like bodies, in daughter cells. The irradiated cells were stained with methylene blue, which indicated that the nucleolar RNA was destroyed by laser microirradiation. Feulgen staining was applied to the irradiated cells in combination with the measurements of an MPV-II model microphotometer. Irradiated nucleoli were negative for DNA-Feulgen stain, which indicated that nucleolar DNA was destroyed by laser irradiation, so the nucleolar organizer gene was destroyed. After the nucleoli had been irradiated, the cells were continuously incubated at 37 degrees C for 12 and/or 24 h, then fixed and stained with AgNO3. Most of the nucleoli irradiated silver-stained negative that demonstrated that when the nucleoli were irradiated, rDNA was destroyed and transcription stopped. However, some silver grains were found in the nucleoplasm, whereas the nucleoli were silver-stained negative. The results suggest that subsidiary nucleolar organizer loci might exist scattered throughout the genome.

Balanced X;15 translocation 46,X,t(X;15)(q21;q23) associated with primary amenorrhea

Cytogenetic studies on a woman with primary amenorrhea showed an X;15 translocation, karyotype 46,X,t(X;15)(q21;q23). Fifteen percent of the buccal cells showed a normal-sized sex chromatin body. The normal X chromosome was uniformly inactivated. Many balanced X;15 translocations have been reported; however, breakpoints in our patient differ from those reported previously. This case also supports earlier evidence that ovarian development fails when the breakpoint of the X chromosome is in the region X q13-q25 or q13-q27.

Optimization of electrofusion parameters for efficient production of murine hybridomas

Several factors which affect the production of murine hybridomas by electrofusion using SP2/0 myelomas were examined. These factors included the ionic composition, specific resistance and osmotic strength of the fusion medium, proteolytic pretreatment of the cells, and field strength of the single, rectangular, 15 or 20 microseconds electric pulse. Individual experiments were observed by phase microscopy, video-recorded, and subsequently analyzed. The efficiency of hybridoma formation was measured by the number of hybrid colonies which survived HAT medium selection. In most cases, the peak efficiency occurred when the pulse field was between 3 and 4 kV/cm. Ca++ and Mg++, in 0.1 and 0.5 mM concentrations, respectively, helped to prevent large-scale SP2/0 lysis following pulse application. Reduction of the osmolarity of the fusion medium allowed for an approximate two-fold increase in the hybrid production efficiency. However, other variations, including an increase of the specific resistance of the medium to 1.7 x 10(4) omega cm, and a reduction of the pulse width to 15 microseconds, allowed significantly higher efficiencies. Dispase pretreatment of the myelomas led to additional improvements when using a 15 microseconds pulse. The data suggest that for this system, the highest efficiencies are obtained by maximizing the attractive polarization forces between cells, while adjusting the ionic composition and pulse parameters to preserve myeloma viability.

Uptake of fluorescence-labeled dextrans by 10T 1/2 fibroblasts following permeation by rectangular and exponential-decay electric field pulses

The uptake of fluorescence-labeled dextrans by adherent 10T 1/2 murine fibroblasts following electric field pulse application was used as a criterion for the efficiency of electropermeation. The cells in monolayers were permeated by immersing a coaxial electrode in culture dishes. The percentage of cells which exhibited fluorescence uptake following electric field pulse application was measured at independently varying pulse field strength and pulse length. Dextrans with molecular weights equal to or higher than 41,000 dalton require higher field strength or longer pulse time to penetrate the cells. There is no detectable advantage of using a rectangular pulse against using an exponential decay pulse of similar power. The uptake was proportional to the product of the pulse amplitude and duration over the experimental range of 40-950 microseconds and 0.1-14.5 kV/cm. Cell survival decreases at the upper end of this range. The result provides a direct comparison of electric parameters which so far have not been standardized with regard to cell electropermeation.

[Cytotoxic effect of hematoporphyrin derivative (HPD) plus light irradiation in vitro]

Cytotoxic effect of HPD plus light irradiation on PTK2 and HeLa cells in vitro were studied by laser microbeam irradiation. The dynamic changes, in three different steps as observed in the cells ranged from visible damage to cell lysis, were recorded at the monocellular level. It was found that the speed of the cytotoxic process varied chiefly with the dose of light used. The cytotoxic progress of PTK2 and HeLa cells was compared and analyzed. In addition, the cytotoxic effects of three different laser wavelengths (6328A, 5145A and 4880A) plus HPD were compared. The most significant killing effect occurred at 6328A wavelength of red light.

Establishment of nucleolar deficient sublines of PtK2 (Potorous tridactylis) by ultraviolet laser microirradiation

One of the two nucleoli of tetraploid PtK2 WA cells in early prophase was irradiated with an ultraviolet (UV) laser microbeam. The daughter cells that maintained the nucleolar deficiency were isolated and cloned. Five nucleolar deficient sublines of PtK2 WA were established, thus providing an experimental system to study the ribosomal gene-nucleolar organizer complex.

Induced genetic deficiency of the nucleolar organizer in rat kangaroo cells (PTK1) by ultraviolet laser microirradiation

An ultraviolet laser microbeam was used to irradiate one of the two nucleolar organizer regions of PTK1 cells in early prophase. The directed nucleolar deficiency induced by ultraviolet laser irradiation was maintained in the daughter cells through subsequent cell generations. However, the frequent occurrence of spontaneous cell fusion in low density cells following the cloning procedure facilitated a recovery of cells to two or more nucleoli.

A new N-nitroso compound, N-3-methylbutyl-N-1-methylacetonylnitrosamine, in corn-bread inoculated with fungi

A new N--nitroso compound, N--1--methylacetonyl--N--3--methylbutylnitrosamine (MAMBNA) is found in corn-bread inoculated with the common fungi, such as Fusarium moniliforme, Geotrichun candidum, Aspergillus terreus or A. flavipes, encountered in food of Lin Xian County, Henan Province. The preliminary identification of this compound with TLC has been confirmed by GC-MS analysis. Furthermore, we have synthesized the MAMBNA and the chemical analysis shows that it is identical with the MAMBNA isolated from the corn-bread extract. In addition to the MAMBNA, dimethylnitrosamine, diethylnitrosamine and methylbenzylnitrosamine are formed also in the fungus-inoculated corn-bread after 8-day incubation and an addition of a small amount of sodium nitrite. The presence of precursor compounds for the formation of nitrosamine in the mouldy maize flour and their significance in respect to the etiology of esophageal cancer in high-risk areas have been discussed.