[Isolation of bilirubin oxidase from Myrothecium verrucaria and the optimum conditions of enzyme production]

A bilirubin oxidase (EC 1.3.3.5) producing strain, Mv 2.1089, was isolated from several strains of Myrothecium verrucaria by dilution method. The optimum conditions of enzyme production were investigated and the results were as follows: the suitable medium was cultured at 25 degrees C on a rotating shaker glucose and peptone, at pH 6.0. The strain was cultured at 25 degrees C on a rotating shaker (150 r/min) for 96 h. Bilirubin oxidase with 0.5-1.5 u/ml was obtained in the culture medium.

A three-year follow-up study of age-related dementia in an urban area of Beijing

A 3-year follow-up study of 1090 people aged 60 years or over in an urban area of Beijing, China, was conducted to determine the incidence of dementia and its characteristics of distribution. This cohort has been studied first in a cross-sectional survey of dementia in 1986. The follow-up examination employed the same interviewers, psychiatrists, instruments (Mini-Mental State Examination and the Crichton Royal Behavior Rating Scale) and diagnostic criteria for dementia (modified DSM-III) in 1989. The respondent rate in this study was 75.7%. The average annual incidence rate of moderate and severe dementia for greater than or equal to 60 years was 0.3% (95% confidence interval 0.08-0.52%). As expected, the rate increased sharply with aging. No sex difference was found. The prevalence rate of moderate and severe dementia was 1.10% among those aged greater than or equal to 65 years, similar to that (1.82%) in the first survey. Our results showed that the multi-infarct dementia was somewhat more common than primary degenerative dementia (ratio 3:2), both among incident cases and current prevalent ones. The average duration of dementia in the community was 8.0 years (SD 3.4). The risk for death in demented patients was 3 times higher than in the whole cohort (standardized mortality ratio = 2.95), and no specific cause of death was observed. In addition, our study showed that elderly people with less education, a history of consistent unemployment, limited physical activity and stroke history had a higher risk for developing dementia.

Contribution of multiple rounds of viral entry and reverse transcription to expression of human immunodeficiency virus type 1. A quantitative kinetic study

Human immunodeficiency virus 1 (HIV-1) infection in vitro has been analyzed by the kinetics of expression of HIV-1 RNA and antigens during treatment with antiviral agents. Intracellular HIV-1 RNA rose from input values of 15 molecules per cell to 28 molecules per cell within 3 h after infection and reached a peak of 13,125 in 5 days. The first detectable increase in levels of HIV-1 capsid protein production was 1 day after infection. Virus infection was interrupted at different time points by the introduction of either 2',3'-dideoxycytidine, 3'-azido-3'-deoxythymidine, or suramin to block reverse transcription, or recombinant soluble CD4 to block binding and re-entry of progeny virus. Two results are noteworthy. First, the three inhibitors of reverse transcription blocked viral expression when added up to 48 h after infection. Second, the extent of infection, although postponed, is not greatly altered by culture of infected cells in recombinant soluble CD4. These data imply that reinfection with progeny virus, while necessary for rapid virus expression, is not required for the establishment of productive HIV-1 infection.

[Selection of optimum technological conditions for vinegar-processing of fresh rhizoma Corydalis]

The Total alkaloid contents of chloroform extracts and aqueous decoctions of different vinegar-processed samples of fresh Rhizoma Corydalis were determined and compared using orthogonal experimental design. Two optimum schemes suggested by the results are 1. If aqueous decoction is wanted, the fresh tuber Corydalis should be scalded by hot edible vinegar till the liquid has permeated to its center; 2. If total alkaloid extract is required for making Chinese traditional patent medicine, the fresh Rhizoma should be slightly scalded with edible vinegar which has been diluted with an equal volume of water.

Refractive index measurement using a standard compensating method

The first three significant digits of a sample's refractive index are compensated by a standard, therefore a precise measurement, which is the same as the refractive index of the standard, can be obtained. The method only needs a thin sample.

[Comparison of analgesic effect between locally vinegar-processed preparation of fresh rhizoma Corydalis and traditionally vinegar-processed rhizoma Corydalis]

Hot plate and writhing methods were used in the comparison of the analgesic effect of vinegar-processed fresh tuber corydalis and the traditionally vinegar-processed Rhizoma Corydalis. The result shows that the effect of the former is stronger than that of the latter.

Lipid-protein interactions in thylakoid membranes of chilling-resistant and -sensitive plants studied by spin label electron spin resonance spectroscopy

Lipid-protein interactions in thylakoid membranes from lettuce, pea, tomato, and cucumber have been studied using spin-labeled analogues of the thylakoid membrane lipid components, monogalactosyl diglyceride and phosphatidylglycerol. The electron spin resonance spectra of the spin-labeled lipids all consist of two components, one corresponding to the fluid lipid environment in the membranes and the other to the motionally restricted lipids interacting with the integral membrane proteins. Comparison of the spectra from the same spin label in thylakoid membranes from different plants shows that the overall lipid fluidity in the membranes decreases with chilling sensitivity. Spectral subtraction has been used to quantitate the fraction of the membrane lipids in contact with integral membrane proteins. Thylakoid membranes of cucumber, a typical chilling-sensitive plant, have been found to have a higher proportion of motionally restricted lipids and a different lipid selectivity for lipid-protein interaction, as compared with those of pea, a typical chilling-resistant plant. This correlation with chilling sensitivity holds generally for the different plants studied. It seems likely that the chilling sensitivity in thylakoid membranes is not determined by lipid fluidity alone, but also by the lipid-protein interactions which could affect protein function in a more direct manner.

The development of the lamprey pattern generator for locomotion

The life cycle of the lamprey includes a larval stage that can last for several years. The motor behavior of the larval lamprey, the ammocoete, has been only minimally studied and little is known of the neural correlates of that behavior. Comparison of known larval behavior to that of adults leaves unclear whether there are large or small changes in the spinal nervous system during transformation. The motor output of isolated larval and transforming spinal cords when stimulated to "swim" with D-glutamate has some differences from that of comparable adult preparations, but shares many important features with adults. Primarily, the fictive swimming is less well regulated and less stable than adults of the same species. We propose that a major difference in the structure and organization of the central pattern generator for locomotion between adults and ammocoetes is a relative lack or immaturity of some cell types that participate in the coordination of the segments and the generation of the rhythm of the periodic bursting.

Inhibitory effect of omeprazole on the metabolism of midazolam in vitro

To examine the effect of omeprazole on the hepatic drug metabolizing enzyme system microsomes from rat and human liver samples were incubated with midazolam (CAS 59467-70-8) in the absence and presence of various concentrations of omeprazole (CAS 73590-58-6), its sulfone metabolite and for comparison also with cimetidine. In the extracted incubation mixtures unchanged midazolam, a-OH-midazolam, 4-OH-midazolam and di-OH-midazolam were analyzed by HPLC. In both species omeprazole (and its sulfone) inhibited the formation of all three oxidized metabolites of midazolam and the corresponding IC50-values (range 0.2-1.3 mmol/l for rat microsomes and 0.2-1.5 mmol/l for human microsomes) were comparable to cimetidine (range 0.05 to 3.8 mmol/l). These results indicate that the oxidative metabolism of midazolam can be inhibited in vitro by omeprazole (and/or its sulfone metabolite) and this interaction should be considered if both drugs are administered concomitantly in man.

[Chemical evaluation of vinegar-processing method for fresh rhizoma Corydalis]

Qualitative and quantitative analysis were carried out on the samples of Rhizoma Corydalis in both the locally vinegar-processed (fresh) and traditionally vinegar-processed forms. No difference was found in the main chemical constituents. However, both the total alkaloids and the corydalis B content of the former are higher than those of the latter.

Tuning sensitivity of dye laser birefringent filters

An analysis of the angle between the optical axis and the optical surface of a birefringent filter used in the cw dye laserhas been made. It shows that the tuning sensitivity of the filter reaches its maximum when the angle is ~30-35 degrees .

[Effects of fu-mai mixture on oxygen consumption, PaO2 and pulmonary artery pressure of animals under hypoxia]

10% Fu-mai mixture has been used in anoxia mice per os 0.5 ml one time. The experimental results indicate that the tolerance to anoxia under low or normal pressures is increased and the oxygen consumption at 5th, 10th, 15th, 20th and 25th minute is reduced. Moreover, the decrease of PaO2 and increase of pulmonic pressure in acute anoxia rabbits can be inhibited by transfusing 2.5 ml of the mixture. The virulence is very slight.

Is cyclosporin A an inhibitor of drug metabolism?

1. The potential for a drug interaction between cyclosporin A and midazolam was investigated since both compounds appear to be metabolized by the same cytochrome P-450 isoenzyme. 2. In vitro evaluation of the binding of cyclosporin A to rat microsomal cytochrome P-450 indicated a Ks-value of 0.4 microM. In further studies with rat liver microsomes IC50-values of 6, 8 and 70 microM cyclosporin A were determined for the inhibition of the metabolism of midazolam to its alpha-OH-,4-OH- and di-OH-metabolites, respectively. 3. Comparative studies with human liver microsomes indicated IC50-values of approximately 300 microM for the formation of alpha-OH-midazolam and of 65 microM for the formation of 4-OH-midazolam. 4. The pharmacokinetics of a single intravenous dose of midazolam (0.075 mg kg-1) was studied in nine patients receiving cyclosporin A to prevent rejection of their transplanted kidneys. The average steady state blood concentrations of cyclosporin A, measured by r.i.a. using a specific monoclonal antibody, varied during a dosing interval between 175 and 600 ng ml-1. 5. In these patients the hepatic elimination of midazolam was characterized by a mean t1/2 (+/- s.d.) of 2.3 +/- 1.2 h and a plasma clearance (CL) of 414 +/- 95 ml min-1. These values were not different from those of normal human subjects (t1/2 = 1.5 to 4 h, CL = 350 to 700 ml min-1). 6. From the results of the in vitro experiments it is concluded that cyclosporin A may potentially inhibit drug metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary lymphomas of the lung: morphological, immunohistochemical and clinical features

Sixty-two cases of primary malignant lymphoma of the lung were investigated. Fifty-eight lymphomas were of B- and two of T-cell type. Two cases of high-grade lymphoma could not be further classified. The largest group (43 cases) consisted of low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue. These showed features similar to low-grade B-cell lymphomas of the mucosa-associated lymphoid tissue of the stomach. The low-grade lymphomas showed a peak occurrence in the sixth decade, the high-grade lymphomas in the seventh decade. Males predominated slightly. Three-quarters of the patients with low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue showed solitary or multiple sharply defined nodules of the lung. The prognosis of the B-cell-derived lung lymphomas without constitutional symptoms was relatively favourable, regardless of whether they were of low- or high-grade malignancy, whereas patients with constitutional symptoms and the two patients with T-cell lymphomas showed a bad prognosis. However, recurrences and metastases in the lung, stomach, lymph nodes and salivary glands were seen in about 46% of the cases of low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue.

Titration of human immunodeficiency virus type 1 (HIV-1) and quantitative analysis of virus expression in vitro using liquid RNA-RNA hybridization

An assay is described for titration of human immunodeficiency virus type 1 (HIV-1) and for quantitative analysis of virus expression in vitro. The assay utilizes a liquid RNA-RNA hybridization method coupled with reversible target capture (RTC) on oligo(dT) derivatized magnetic particles. The assay provides a rapid, specific, and sensitive method for quantitation of HIV-1 RNA molecules present either in cells or in viral particles from cell-free culture media. Chronically infected monocytoid U1.1 cells were found to carry 52 pg HIV-1 RNA per 200,000 cells (160 HIV-1 RNA molecules per cell). In contrast, acutely infected CEM and H9 cells carried 3010 and 4370 pg HIV-1 RNA per 200,000 cells (9040 and 13,110 HIV-1 RNA molecules per cell, respectively). No hybridization was observed with uninfected cells or cells infected with HIV-2, HTLV-I, HTLV-II, or EBV. Use of liquid HIV-1 RNA hybridization in association with HIV-1 protein detection methods permits more complete characterization of HIV-1 expression in host cells than either method alone, and also provides a method for standardizing preparations of virus.

Lipid-protein interactions in stacked and destacked thylakoid membranes and the influence of phosphorylation and illumination. Spin label ESR studies

The effects of membrane destacking, protein phosphorylation, and continuous illumination have been studied in pea thylakoid membranes using ESR spectroscopy of an incorporated spin-labelled phosphatidylglycerol. This spin-labelled analogue of an endogenous thylakoid lipid has previously been shown to exhibit a selectivity of interaction with thylakoid proteins. Neither destacking, phosphorylation nor illumination was found to change the ESR spectra appreciably, suggesting that for phosphatidylglycerol at least, neither the number of protein-associated membrane lipids nor their pattern of selectivity was altered. The redistribution of the thylakoid protein complexes in the membrane, under these various conditions, therefore takes place with conservation of the properties of the lipid/protein interface.

Determination of the fast axis with an infrared spectrometer for quartz and mica waveplates

The variation of dichroism with wavelength is used in an infrared spectrometer to find the fast and slow axes of quartz and mica waveplates.

[Observations on neuronal activity in frontal cortex and EMGs in monkeys during performing noxious and innocuous heat discrimination GO/NO-GO task]

To study the functional implication of neuronal responses in frontal cortex to noxious and innocuous heat stimuli, experiments were carried out on two monkeys (Macaca mulatta) during performing a delayed discrimination GO/NO-GO task. The animals were trained to hold a lever for at least 3 s in the response period when an innocuous heat stimulus had been applied to the forearm in the cue period, or release it within 1 s with a noxious one. After a criterion of 90% of correct responses in 3 successive days was reached, single neuronal activity was recorded from the frontal cortex along with EMGs from six muscles in both arms. Of 142 task-related neurons recorded, 87 (66.4%) were related to heat, 34 to visual, and 21 to both visual and heat stimuli. Among the heat-related neurons, 22 were responsive to noxious heat, 18 to innocuous heat, and 47 to both. Of the neurons responding to both noxious and innocuous heat stimuli, 4 neurons showed changes in discharge rates, depending on the type of stimuli. In most cases, muscular activities just appeared at the moment of lever pressing and/or releasing in m. extensor digitorium communis, m. flexor carpi ulnaris and m. flexor carpi radialis of the performing arm. No regular muscular activities appeared in other muscles and in other periods of the task. The result showed that the neuronal responses in frontal cortex elicited by heat stimuli in the cue period were not related directly to the initiation and modulation of behaviours.(ABSTRACT TRUNCATED AT 250 WORDS)