A novel protein, CSG2p, is required for Ca2+ regulation in Saccharomyces cerevisiae

Nineteen mutants that lost the ability to grow in 100 mM Ca2+ (but remained insensitive to 50 mM Sr2+) were identified in a screen of approximately 60,000 mutagenized yeast colonies. Cells carrying mutations in the CSG2 gene grow normally in low Ca2+ medium but have decreased growth rates when the Ca2+ concentration is above 10 mM. The csg2 mutant cells accumulate much higher levels of Ca2+ in a compartment that is exchangeable with extracellular Ca2+ but the nonexchangeable Ca2+ pool which predominates in wild-type cells is not influenced. Sr2+ influx is not increased in the csg2 mutant cells. Mg2+ decreases the amount of Ca2+ in the non-exchangeable pool without influencing the csg2-induced exchangeable Ca2+ pool. The data indicate that the csg2 mutation causes a selective increase in Ca2+ accumulation into a pool which is distinct from the vacuolar pool. The CSG2 protein consists of 410 amino acids, contains nine putative transmembrane segments, four potential sites for N-linked glycosylation, and a sequence with homology to the EF-hand Ca(2+)-binding site.

Postingestive alliesthesia produced by exogenous cholecystokinin and blocked by abdominal vagotomy

Facial consummatory responses reflecting ingestive and aversive perceptions were studied and quantified in rats chronically implanted with oral catheters. A gustatory stimulus of 50 microliters of 1.75 M sucrose was injected into the mouth every 5 min during 65 min. At 5 min, 2 micrograms/kg exogenous cholecystokinin (CCK) was injected intraperitoneally. Typical ingestive facial consummatory responses were observed in response to sweet stimuli before the load. Aversive consummatory responses were observed in response to sweet stimuli after the intraperitoneal exogenous CCK (negative alliesthesia). Control intraperitoneal injection of saline was not followed by negative alliesthesia in response to sweet oral stimuli. In the last part of the experiment rats were vagotomized or underwent sham operation. When the vagotomized rats were again subjected to the same gustatory sessions, the intraperitoneal exogenous CCK was not followed by negative alliesthesia in response to sweet stimuli, whereas sham-operated rats presented a strong negative alliesthesia. These results in rats suggest that CCK mediates duodenal preabsorptive signal for alimentary alliesthesia. They also suggest that the effect is peripheral, with the vagus nerve as afferent pathway.

[Investigation on vertigoes in childhood]

This paper analysed the pathogenesis and the vestibular test results of 87 cases of vertigo in the childhood below the age of 13 years old. 83 cases (95.4%) were vestibular peripheral lesions, and 4 cases were vestibular central lesions. 34.5% of them were benign paroxysmal vertigo and 14.9% were the Meniere's disease which all occurred at the age more than 9 years old. The appearances of ENG were semicircular canal hypofunction in 57 cases (65.5%). The function of ocular movement was abnormal in a few cases. The posturography results were compared with an age-matched control group. Posturographic recording showed length of locus and velocity increased in the thirteen patients of semicircular canal hypofunction.

Effects of low-level lead on retinal ganglion sustained and transient cells in developing rats

Neonatal rats were exposed to lead from parturition to weaning via the milk of dams drinking 0.2% lead acetate solutions. The alterations in the excitability and temporal response properties of retinal ganglion cells in adult rats (90 days) following developmental lead exposure were studied. The results of this investigation demonstrated that the lead exposure in neonatal rats caused an increase in excitability, and a decrease in optimal temporal frequency, bandwidth at half amplitude, temporal resolution, and response phase of the retinal ganglion cells in adult rats. Compared with the sustained cells, the transient cells had a much greater alteration in excitability and temporal response properties.

Experimental study of the internal signal of alliesthesia induced by sweet molecules in rats

To identify the preabsorptive signal that arouses alliesthesia, we compared the effects of five sweet molecules: glucose (3 g.5 ml-1), cyclamate (0.280 g.5 ml-1), saccharin (0.016 g.5 ml-1), aspartame (0.020 g.5 ml-1), and mannitol (3 g.5 ml-1) on the intestive aversive responses of rats. In Experiment 1, the sweet stimuli were adjusted to taste similarly sweet, and they were administered orally; they aroused similar ingestive responses. In Experiment 2, an isovolumetric load of each of the five molecules was administered in the stomach and its influence on ingestive/aversive response aroused by oral sucrose was recorded. Negative alliesthesia was obtained after gastric loads of glucose and mannitol, but not after gastric loads of cyclamate, saccharin, and aspartame.

A bioassay based on recombinant DNA technology for determining selenium concentration

The trace element selenium has recently attracted attention, particularly because (i) selenocysteine is involved in the active site of various prokaryotic and eukaryotic enzymes, some of which have a role in human health; (ii) selenocysteine incorporation into these proteins is coded by UGA codons; and (iii) as a result, selenocysteine is now considered to be the 21st amino acid in an expanded genetic code. Here, we built recombinant DNA constructs in which expression of the lac'Z gene is driven in Escherichia coli by UGA-directed selenocysteine incorporation. In this system, levels of beta-galactosidase activity are proportionally and specifically related to the presence and concentrations of several specific simple selenium derivatives. The system can thus be used as a sensitive bioassay for their determination. This bioassay is one of a few using recombinant DNA technology to provide a reporter for simple detection of a chemical trace element.

[Analysis of trace elements in scalp hair of healthy people, breast cancer and hyperplasia patients with XRF method]

The trace element analysis on the scalp hair of patients with breast cancer and hyperplasia was made using the XRF method and compared with that of healthy people. The hair samples from 42 breast cancer patients, 57 hyperplasia patients and 31 healthy people were collected respectively. The results showed that Mn, Cr and K content in the hair of the patients with cancer was much higher than that of the normal (P < 0.05). Significant differences were also found between patients with breast cancer and with hyperplasia in K and Fe content. The former was much higher than the latter (P < 0.05).

Observation of therapeutic effect in 50 cases of chronic renal failure treated with rhubarb and adjuvant drugs

Treatment of chronic renal failure with rhubarb and adjuvant drugs combined with other appropriate measures alleviates the suffering of the patients and improves the quality of their survival. Most patients can take care of themselves after treatment, and some can engage in half-day work. The treatment prolongs the life of the patient, and reduces medical expenses. It is of definite social and economic benefit, and conforms with China's conditions. Except for very severe cases whose blood creatinine exceeds 884 mumol/L, it can be given to all patients. It can also be used as a transitional measure before more radical therapies may be instituted.

Evaluation of the critical value of driving fatigue based on the fuzzy sets theory

Applying the newly developed multistage evaluation method based on the fuzzy sets theory, we have evaluated the sense of driving fatigue of 8 male drivers who covered 400 km in 8 hr in the daytime, empirically revealing the distribution of the degree of driving fatigue. The critical values from "no" to "a bit" and "a bit" to "fatigued" are 1 and 5.5 hr, respectively. Finally, a tentative study of the psychophysical relations between driving time and driving fatigue has been made, leading to a curve of driving fatigue under the conditions of this experiment.

[Preparation of an anti-human immunotoxin against bladder carcinoma and its in vitro targeting cytotoxicity]

The intact ricin was linked to a monoclonal antibody BD I-1, which recognizes a determinant expressed on two human bladder carcinoma cell lines, BIU-87 and E-J, to form an immunotoxin BD I-1 Ricin. The results of indirect immunofluorescence test, FACS analysis and competition binding assay showed that the binding activity of antibody in this immunotoxin was retained by 80% of the original activity. The in vitro cytotoxicity assay indicated that the immunotoxin in the presence of 0.1 mol/L galactose is potent cytotoxic agent for BIU-87 and E-J cell lines. The immunotoxin BD 1-1-Ricin could kill the target cells BIU-87 and E-J cell lines by 50% at a concentration of 0.00008 mumoI/L and 0.00025 mumol/L respectively. At a concentration of 0.001 mumol/L no apparent cytotoxic activity to human colon carcinoma Lovo cell line was observed.

[Determination of sugar components in wild and cultured sclerotia of Grifola umbellata (pers. ex Fr.) Pilat at different ages]

Our determination indicates that in both wild and cultured sclerotia of Grifola umbellata the contents of reducing sugar decrease with the growing years; the contents of Polysaccharide peak in the second year of growth; the contents of protein increase with the growing years; the contents of fat reaches maximum in the first year of growth; in cultured sclerotia ergosterol becomes highest in contents when the plant is two years old, while in wild sclerotia it remains lowest.

Potent HIV-1 protease inhibitors with antiviral activities in vitro

A series of novel difluoroketones with low molecular weight (less than 600 m.u.) and which are potent inhibitors of the HIV-1 protease (IC50 = 1.0 to 21 nM) were synthesized. These compounds also exhibited antiviral activity by inhibition of the cytopathic effect of HIV-1(3)B in MT-4 cells in vitro.

[Determination of water soluble silicon from herbal drugs]

This article has set up a method for silicon determination by ammonium molybdate-ferrous sulfate-sodium carbonate spectrophotometry. The method is simple, convenient, quick, effective and free of the influence of phosphate ion and reducing agents such as vitamin C and so on. By this method water soluble silicon has been determined in 38 herbal drugs.

[An APC composite analysis system for analyzing the cause of perinatal death]

As the cause of perinatal death is multi-factorial and complex, its analysis should be a composite one. The method stated here includes the following: The APC analysis system. A is autopsy, P is placental pathological examination and C is the clinical data. The analysis is based mainly on the diagnosis of autopsy, with the findings of placenta as a non-negligible component part of the autopsy. As for the clinical data, they are both as the start point of the autopsy and the final check for the conclusion drawn from the pathological examination. The analysis procedure of a complex case is given in detail for example. Strictly applying this system, the causes of perinatal death were clarified in 99.3% of 137 cases, and in 98.6% (66/67) of stillbirths. The underlying factors of primary perinatal death are usually neglected, which could be found out as well with this system. For example, the underlying factors inducing intrauterine anoxia of 92.3% of cases (36/39) were determined by using the APC system. The role played by the placental pathological examination in this analysis system is clearly shown and stressed, especially in the stillbirths. The quality of causal analysis of perinatal death is greatly improved by applying the APC analysis system.

Observations on the treatment of coronary heart disease by kuo guan qu yu ling

Based on the therory of promoting flow of qi and dispersing blood stasis, the KUO GUAN QU YU LING coronary--dilating and stagnation--dispersing) powder in capsules were prepared for the treatment of 60 cases of coronary heart disease. After a 30 day course of treatment, cardiac ischemia was improved in 64.7% and the symptom of angina pectoris was relieved in 61.7% of the patients. This drug also acted to reduce blood lipids and to improve left cardiac function. Pharmacological study indicated that this preparation improved the tolerance of cardiac muscle against anoxia and prevented ventricular fibrillation and cardiac damage from ischemia.