Evaluation of the quality of bedside monitoring of the blood glucose level in a teaching hospital.

We evaluated the precision and accuracy of monitoring of the blood glucose level in the laboratory and at the bedside with one of four glucose meters by an experienced operator and by 39 nurses in a teaching hospital. For precision studies aqueous quality control materials were used. A total of 85 blood samples were tested. The precision of the glucose meters (expressed as the coefficient of variation [CV]) in the hands of the experienced operator ranged from 6.7% to 11.1%. The correlation between the values obtained by the experienced operator and the reference values obtained in the laboratory was high (0.95 to 0.98). The precision of the values obtained by the nurses using the meters ranged from 13.7% on medical wards to 45.7% in the intensive care unit (ICU). The correlation between these values and those obtained in the central laboratory ranged from 0.72 to 0.82. Twenty-four percent of the glucose values determined on medical wards and 62% of those determined in the ICU deviated from the reference value by at least 20%. Of the 85 patients 12 (14%) would have received different insulin dosages had the reference value been available at the same time as the glucose meter reading: in 3 of the patients the discrepancy was 6 units of insulin or greater. Continuous quality control of bedside monitoring of the blood glucose level is needed. In addition, personnel who use glucose meters should receive adequate training.     

An isothermal titration calorimetric method to determine the kinetic parameters of enzyme catalytic reaction by employing the product inhibition as probe.

An isothermal titration calorimetric (ITC) method was developed to measure the kinetic parameters of ribonuclease A catalytic hydrolysis of cytidine 2',3'-cyclic monophosphate. Employing the inhibition of product as a probe, the K(m), K(i), k(c), and DeltaH(m) can be determined by two simple calorimetric measurements. First, the substrate was titrated into the cell containing high concentration of enzyme. The molar reaction heat was calculated from the titration peak area divided by substrate moles per titration, and the initial catalytic reaction rate in the presence of various concentrations of product can be calculated from the peak height and the molar reaction heat. From Michaelis-Menten function in the presence of inhibitors, the relationship between K(m) and K(i) can be obtained. Then, the dissociation constant, which is equal to K(i), was measured by a regular ITC experiment. Thus, K(m) and k(c) can be calculated. The method developed here can be applied in other enzyme catalytic systems with inhibitive products.     

Expression of dengue virus structural proteins and nonstructural protein NS1 by a recombinant vaccinia virus.

A recombinant vaccinia virus containing cloned DNA sequences coding for the three structural proteins and nonstructural proteins NS1 and NS2a of dengue type 4 virus was constructed. Infection of CV-1 cells with this recombinant virus produced dengue virus structural proteins as well as the nonstructural protein NS1. These proteins were precipitated by specific antisera and exhibited the same molecular size and glycosylation patterns as authentic dengue virus proteins. Infection of cotton rats with the recombinant virus induced NS1 antibodies in 1 of 11 animals. However, an immune response to the PreM and E glycoproteins was not detected. A reduced level of gene expression was probably the reason for the limited serologic response to these dengue virus antigens.     

Sequence and translation of the murine coronavirus 5''-end genomic RNA reveals the N-terminal structure of the putative RNA polymerase.

A 28-kilodalton protein has been suggested to be the amino-terminal protein cleavage product of the putative coronavirus RNA polymerase (gene A) (M.R. Denison and S. Perlman, Virology 157:565-568, 1987). To elucidate the structure and mechanism of synthesis of this protein, the nucleotide sequence of the 5' 2.0 kilobases of the coronavirus mouse hepatitis virus strain JHM genome was determined. This sequence contains a single, long open reading frame and predicts a highly basic amino-terminal region. Cell-free translation of RNAs transcribed in vitro from DNAs containing gene A sequences in pT7 vectors yielded proteins initiated from the 5'-most optimal initiation codon at position 215 from the 5' end of the genome. The sequence preceding this initiation codon predicts the presence of a stable hairpin loop structure. The presence of an RNA secondary structure at the 5' end of the RNA genome is supported by the observation that gene A sequences were more efficiently translated in vitro when upstream noncoding sequences were removed. By comparing the translation products of virion genomic RNA and in vitro transcribed RNAs, we established that our clones encompassing the 5'-end mouse hepatitis virus genomic RNA encode the 28-kilodalton N-terminal cleavage product of the gene A protein. Possible cleavage sites for this protein are proposed.     

秦岭产珠子参叶的达玛烷型皂甙研究(1)

从陕西省秦岭产珠子参(Panax japonicus C.A.Meyer var.major(Burk.)Wu etFeng)的叶中分离到十个新的达玛烷型四环三萜皂甙,经光谱测定和化学降解,其中四个的化学结构分别为珠子参甙(majoroside)F_1(1)、F_2(2)、F_3(3)和F_4(4)。同时,还分离到已知的人参甙(ginsenoside)Rd(5)、Re(6)、Rg_1(7)、Rg_2(8)和F_2(9)。     

Low-Level Microwave Irradiations Affect Central Cholinergic Activity in the Rat

Sodium-dependent high-affinity choline uptake was measured in various regions of the brains of rats irradiated for 45 min with either pulsed or continuous-wave low-level microwaves (2,450 MHz; power density, 1 mW/cm2; average whole-body specific absorption rate, 0.6 W/kg). Pulsed microwave irradiation (2-microseconds pulses, 500 pulses/s) decreased choline uptake in the hippocampus and frontal cortex but had no significant effect on the hypothalamus, striatum, and inferior colliculus. Pretreatment with a narcotic antagonist (naloxone or naltrexone; 1 mg/kg i.p.) blocked the effect of pulsed microwaves on hippocampal choline uptake but did not significantly alter the effect on the frontal cortex. Irradiation with continuous-wave microwaves did not significantly affect choline uptake in the hippocampus, striatum, and hypothalamus but decreased the uptake in the frontal cortex. The effect on the frontal cortex was not altered by pretreatment with narcotic antagonist. These data suggest that exposure to low-level pulsed or continuous-wave microwaves leads to changes in cholinergic functions in the brain.     

用薄层色谱分离提纯单半乳糖和双半乳糖双甘油酯

本文选择两种溶剂体系,用两次单向薄层层析,从小麦抗寒与不抗寒品系天然橡胶胶乳分离提纯出6种单半乳糖和双半乳糖双甘油酯。并比较了它们的疏水侧链的脂肪酸组成。小麦糖脂疏水侧链脂肪酸的不饱和指数远大于天然胶乳糖脂。抗寒品系胶乳糖脂疏水侧链脂肪酸不饱和指数大于不抗寒品系。双半乳糖双甘油酯疏水侧链脂肪酸不饱和指数均大于其单半乳糖糖脂。     

Evidence for a junctional feet-ryanodine receptor complex from sarcoplasmic reticulum

Heavy sarcoplasmic reticulum vesicles, labelled with the Ca2+ release channel probe [3H]ryanodine, were solubilized in detergent, then centrifuged through sucrose gradients. A single peak of ryanodine binding activity was observed with an apparent sedimentation coefficient of 30S. Electron microscopy of the peak fraction showed disk structures of 25-28 nm diameter and 10 nm thickness. Proteins specifically enriched in the peak fraction were the Mr 160,000 and 260,000 and junctional feet proteins (Mr 320,000 and 300,000). This suggests that the feet proteins and ryanodine receptor may be specifically associated into a large oligomeric complex comprising subunits of Mr 160,000-320,000.