Elevation of glutathione levels by ammonium ions in primary cultures of rat astrocytes

It is well established that ammonia is detoxified in the brain to form glutamine and that astrocytes play a major role in this process. The synthesis of glutamine requires glutamate and ATP. Since glutamate and ATP are also required for the synthesis of glutathione (GSH), we examined the effect of pathophysiological concentrations of ammonia on levels of GSH in primary cultures of astrocytes. GSH content in the medium increased in a dose- and time-dependent manner in the presence of ammonia. After an initial decrease, cellular GSH content increased in a similar manner. The levels of glutathione disulfide (GSSG) were also increased. A linear relationship was observed between ammonia concentration and the increase in GSH levels. An increase in the efflux of GSH from cells into medium was also observed under these conditions. Buthionine sulfoximine and acivicin, but not methionine sulfoximine, blocked the ammonia induced increase in GSH levels. No, or minor, changes in the activities of enzymes (gamma-glutamyl transpeptidase, GSH reductase and GSH-peroxidase) that might influence GSH levels were identified and thus could not account for the ammonia induced increase in GSH levels in astrocytes. These findings indicate that pathophysiological concentrations of ammonium ions result in increased astroglial levels of GSH which may affect the metabolism and function of astrocytes.

[Relation of pilots symptoms with some physiological parameters under vestibular stimulus]

OBJECTIVE

To investigate the relation of vestibular stimulus induced symptoms to electrogastrogram (EGG), electronystagmogram (ENG), acupoint potential (AP), skin temperature (ST) heart rate variability (HRV) and content of urine hormones.

METHOD

The physiological parameters were recorded before, during and after vestibular stimuli. Graybiel's scoring standard was used, and progressive regression analysis of symptoms and physiological parameters were made.

RESULT

The regression equations were obtained from data before, during and after the stimuli.

CONCLUSION

Three regression equations might be used.

Molecular basis of NMDA receptor-coupled ion channel modulation by S-nitrosylation

Several ion channels are thought to be directly modulated by nitric oxide (NO), but the molecular basis of this regulation is unclear. Here we show that the NMDA receptor (NMDAR)-associated ion channel was modulated not only by exogenous NO but also by endogenous NO. Site-directed mutagenesis identified a critical cysteine residue (Cys 399) on the NR2A subunit whose S-nitrosylation (NO+ transfer) under physiological conditions underlies this modulation. In cell systems expressing NMDARs with mutant NR2A subunits in which this single cysteine was replaced by an alanine, the effect of endogenous NO was lost. Thus endogenous S-nitrosylation can regulate ion channel activity.

Treatment of severe electrical burns

In summary, electrical injury is a typical type of burn injury with a unique mechanism of systemic and local damage. Resuscitation is more complex in critical patients than that of thermal injury. Local management is more difficult, which could be eventually accomplished by sequential procedures of debridement and operation. Although the modern trend of performing early debridement and operation might be promising, traditional experiences are still being used in clinical care. Progress in clinical management has brought about an improvement in therapeutic outcome, resulting in a decrease of amputation rate and reduced disability. Some typical types of electrical injury demand special treatment, which might prove to be effective. Close observation and timely treatment of the injury itself and related complications will be lifesaving in caring for critical electrical injury. Some special therapeutic measures would be indicated and might be fruitful in proving their efficacy. New measures aimed at theoretical problems will be promising if electroporation could be effectively treated.

[Epidemiological analysis on the risk factors of intrauterine transmission of hepatitis virus C]

OBJECTIVE

To investigate the possibility and risk factors of intrauterine transmission of hepatitis virus C (HCV) in Taiyuan City.

METHODS

Anti-HCV and HCV RNA were detected by enzyme linked immunosorbent assay(ELISA) and reverse transcriptase Polymerase Chain Reaction(RT-PCR), in 64 mothers with HCV or HCV RNA positive and their newborns cord blood samples. Case-control study was used for the risk factors analysis.

RESULTS

The infection rate of HCV was 66.15% in newborns from anti-HCV or HCV RNA positive mothers. The intrauterine transmission rate was 100% in newborns from HCV RNA positive mothers. There was a significant correlation between HCV intrauterine transmission and maternal history of blood transfusion and abnormal serum alanine aminotransferase(ALT), and the relative risk was 317.15 and 2.60, respectively.

CONCLUSIONS

The higher incidence of intrauterine transmission was found in newborns from HCV RNA or anti-HCV positive mothers. The high risk factors of intrauterine transmission are maternal blood transfusion history and abnormal ALT.

Proteasome-dependent cyst formation and stage-specific ubiquitin mRNA accumulation in Entamoeba invadens

Proteases play an important role in the pathogenic mechanisms and differentiation events of protozoan parasites; the proteasome/ubiquitin system is essential for maintaining the differentiation state of many cell types. A single input of the specific inhibitor of proteasomes, lactacystin, prevented encystation of the protozoan parasite Entameoba invadens, whereas a cysteine protease inhibitor, E64, only delayed encystation. The ameba target of lactacystin was purified and it displayed the features typical of eukaryotic 20S proteasome complexes. In addition, transcripts encoding ubiquitin were detectable in trophozoites stage cells, disappeared immediately following transfer of amoebae to encystation induction medium, and reappeared at the same time during encystation as other encystation-specific transcripts. These results demonstrate that proteasome function is required during the conversion of the disease-causing trophozoite into the infectious cyst stage of Entamoeba parasites, and that ubiquitin transcript levels undergo an unusual decrease during the early stages of this differentiation process.

Immunocytochemical localization of histamine in enterochromaffin-like (ECL) cells in rat oxyntic mucosa: a transmission electron microscopy study using monoclonal antibodies and conventional glutaraldehyde-based fixation

Histamine (HA), contained in the enterochromaffin-like (ECL) cells of the gastric mucosa in animals, plays an important role in gastric acid secretion, although methods for its exact morphological localization are still lacking. We used a pre-embedding indirect immunoperoxidase approach to define the fine structural localization of HA in rat oxyntic mucosa that was fixed with a glutaraldehyde-based fixative and HA monoclonal antibodies (MAbs AHA-1 and 2). Transmission electron microscopy showed that the peroxidase endproduct not only was concentrated in the cores of cytoplasmic granules but also was distributed to a high degree in the cytoplasm peripheral to the granules of the ECL cells. These results suggest that in ECL cells HA is enzymatically synthesized in the cytoplasm, then is transported and stored in the cores of the granules before its release from the basal lamina. The present HA immunoelectron microscopic method with MAbs would be applicable more generally to the ultrastructural identification of HA-containing cells.

A genetic linkage map of tef [Eragrostis tef (Zucc.) Trotter] based on amplified fragment length polymorphism

A genetic linkage map of tef was constructed with amplified fragment length polymorphism (AFLP) markers using F(5) recombinant inbred lines (RILs) derived by single seed descent from the intraspecific cross of 'Kaye Murri'×'Fesho'. A total of 192 EcoRI/MseI primer combinations were screened for parental polymorphism. Around three polymorphic fragments per primer combination were detected, indicating a low polymorphism level in tef. Fifty primer combinations were selected to assay the mapping population, and 226 loci segregated among 85 F(5) RILs. Most AFLP loci behaved as dominant markers (presence or absence of a band), but about 15% of the loci were codominant. Significant deviations from the expected Mendelian segregation ratio were observed for 26 loci. The genetic linkage map comprised 211 markers assembled into 25 linkage groups and covered 2,149 cM of genome. AFLP is an efficient marker system for mapping plant species with low polymorphism such as tef. This is the first genetic linkage map constructed for tef. It will facilitate the mapping of genes controlling agronomically important traits and cultivar improvement in tef.

Amplified fragment length polymorphism markers linked to a major quantitative trait locus controlling scab resistance in wheat

ABSTRACT Scab is a destructive disease of wheat. To accelerate development of scab-resistant wheat cultivars, molecular markers linked to scab resistance genes have been identified by using recombinant inbred lines (RILs) derived by single-seed descent from a cross between the resistant wheat cultivar Ning 7840 (resistant to spread of scab within the spike) and the susceptible cultivar Clark. In the greenhouse, F(5), F(6), F(7), and F(10) families were evaluated for resistance to spread of scab within a spike by injecting about 1,000 conidiospores of Fusarium graminearum into a central spikelet. Inoculated plants were kept in moist chambers for 3 days to promote initial infection and then transferred to greenhouse benches. Scab symptoms were evaluated four times (3, 9, 15, and 21 days after inoculation). The frequency distribution of scab severity indicated that resistance to spread of scab within a spike was controlled by a few major genes. DNA was isolated from both parents and F(9) plants of the 133 RILs. A total of 300 combinations of amplified fragment length polymorphism (AFLP) primers were screened for polymorphisms using bulked segregant analysis. Twenty pairs of primers revealed at least one polymorphic band between the two contrasting bulks. The segregation of each of these bands was evaluated in the 133 RILs. Eleven AFLP markers showed significant association with scab resistance, and an individual marker explained up to 53% of the total variation (R(2)). The markers with high R(2) values mapped to a single linkage group. By interval analysis, one major quantitative trait locus for scab resistance explaining up to 60% of the genetic variation for scab resistance was identified. Some of the AFLP markers may be useful in marker-assisted breeding to improve resistance to scab in wheat.

[Effects of vestibular stimulus on heart rate variability]

Possible effects of vestibular stimulation autonomic nerve function in pilots were studied by observing changes of Heart Rate Variability (HRV). Time domain and frequency domain analyses demonstrated that the primarily averages, standard deviation of the HRV averages(SD), least or greatest value, deviation of greatest minus least value, interrelated averages, square root of the mean of the sum of squares of differences between adjacent R-R intervals (RMSSD), total power(TP), low frequency(LF), high frequency(HF), LF/TP, HF/TP, and LF/HF all had significant increase or decrease (P <0.05 - <0.01) and the degrees of changes were related to the intensity of the stimulations.

Immunoelectron microscopic study for polyamines

The polyamines (PAs) are ubiquitous polycationic metabolites in eukaryotic and prokaryotic cells and are believed to be intimately involved in the regulation of DNA, RNA, and protein biosynthesis, the exact function of which remains unclear, mainly because of a lack of knowledge of PA subcellular localization. In this study, using immunoelectron microscopy, we have demonstrated that PAs are predominantly located on free and attached ribosomes of the rough endoplasmic reticulum in the neurons of the lateral reticular nucleus of rat medulla oblongata. The nuclei, axons, and nerve endings were devoid of PA. This suggests that PAs are one of the components of biologically active ribosomes, being closely involved in the translation processes of protein biosynthesis.

Synergistic activation of the N-methyl-D-aspartate receptor subunit 1 promoter by myocyte enhancer factor 2C and Sp1

The N-methyl-D-aspartate (NMDA) subtype of glutamate receptor plays important roles in neuronal development, plasticity, and cell death. NMDA receptor subunit 1 (NR1) is an essential subunit of the NMDA receptor and is developmentally expressed in postnatal neurons of the central nervous system. Here we identify on the NR1 promoter a binding site for myocyte enhancer factor 2C (MEF2C), a developmentally expressed neuron/muscle transcription factor found in cerebrocortical neurons, and study its regulation of the NR1 gene. Co-expression of MEF2C and Sp1 cDNAs in primary neurons or cell lines synergistically activates the NR1 promoter. Disruption of the MEF2 site or the MEF2C DNA binding domain moderately reduces this synergism. Mutation of the Sp1 sites or the activation domains of Sp1 protein strongly reduces the synergism. Results of yeast two-hybrid and co-immunoprecipitation experiments reveal a physical interaction between MEF2C and Sp1 proteins. The MEF2C DNA binding domain is sufficient for this interaction. Dominant-negative MEF2C interferes with expression of NR1 mRNA in neuronally differentiated P19 cells. Growth factors, including epidermal growth factor and basic fibroblast growth factor, can up-regulate NR1 promoter activity in stably transfected PC12 cells, even in the absence of the MEF2 site, but the Sp1 sites are necessary for this growth factor regulation, suggesting that Sp1 sites may mediate these effects.

[Patterns of care in community mental health services in Lombardy]

OBJECTIVE

The analysis aims to study patterns of care of patients in contact with 5 Psychiatric Services in Lombardy. Four patterns have been identified long term-high users, non long term-high users, long term-non high users, non long term-non high users.

DESIGN

Data were provided by the regional Psychiatric Information System. The cohort of patients have been composed by 5,670 patients included in 1994 one year prevalence.

SETTING

Five Psychiatric Services (Merate, Treviglio, Crema, Desio, Castano Primo) with a total population of 610,184 inhabitants aged over 14. MAIN UTILISED MEASURES: Some sociodemographic and clinical variables have been taken into consideration for a descriptive analysis; a multinomial logistic regression model was used to identify the characteristics of patients associated with different patterns.

RESULTS

Long term-high users were 5.3%, i.e. a mean rate of 4.9/10,000 residents over 14, and absorbed 60% of resources, the absence of a partner was associated in regression analysis with this pattern. Non long term-high users were 1.2%, i.e. a mean rate of 1.1/10,000 residents over 14, and absorbed 7.8% of resources; age below 45, unemployment, absence of a partner, severe mental illness and first contact with Psychiatric Services in the period 1985-1989 were predictive variables. Long term-non high users were 23.4%, i.e. a mean rate of 21.6/10,000 residents over 14, and absorbed 18.1% of resources; age below 45, unemployment, living alone, absence of a partner, severe mental illness and first contact with Psychiatric Services before 1990 were predictive variables. Non long term-non high users were 70.1%, i.e. a mean rate of 64.8/10,000 residents over 14 and, absorbed 18.1% of resources.

CONCLUSIONS

Data show that on the whole the activity of Psychiatric Services is addressed to most serious patients, though considerable differences between Psychiatric Services utilisation may be found. This study highlights the importance of a regional Psychiatric Information System, that allows the monitoring in time and in the regional territory of patterns of care.

Enzyme immunoassay for a characteristic protein in the animal crude drug lumbricus

A new method was developed to measure the content of a Lumbricus component in a traditional Chinese medicine (TCM). An antiserum specific to Lumbricus was elicited in a rabbit following immunization with a suspension of Lumbricus fragments. A characteristic antigen protein, 70 kDa, was found in Lumbricus and was purified almost to singleness using a column chromatography series of gel filtration and DEAE-Sepharose. A selected antibody enzyme immunoassay (SAEIA) was developed using the antiserum and the purified 70 kDa protein as a solid-phase antigen. The SAEIA was specific to Lumbricus species, and showed no cross-reaction with any crude drugs other than Lumbricus. This SAEIA detected 70 kDa protein in the amount of 10 ng/ml with excellent reproducibility (coefficient of variation=3.0%) and an EC50 of 0.24 microg/ml. Using this assay, Lumbricus levels were easily determined in a Lumbricus-based TCM Kazecoll, but not in the control Kazecoll (Kakkonto) prepared without Lumbricus. The SAEIA for 70 kDa protein was simple, accurate, reproducible and may provide a general analytical method for the quality control of Lumbricus-based TCMs.

Androgen regulation of the human ornithine decarboxylase promoter in prostate cancer cells

We studied the response of the human ornithine decarboxylase (ODC) promoter to androgen in human prostate cancer cell lines. In the well-differentiated, androgen-sensitive human prostate cancer line LNCaP, a genomic ODC promoter fragment that includes putative androgen response elements was suppressed by androgen. In contrast, the androgen-regulated probasin promoter was induced by androgens. The ODC promoter was also induced by cotransfected androgen receptor in the poorly differentiated, androgen-insensitive human prostate cancer cell line PPC-1. We examined the effects of cotransfected mutant androgen receptors containing the LNCaP mutation or DNA-binding mutations. All cotransfected androgen receptors switched the ODC androgen response from suppression to induction in LNCaP cells. Gel-shift and DNA footprint assays demonstrated androgen receptor binding to an ODC sequence that does not contain a consensus androgen response element. Deletion of the sequence abolished androgen suppression of the ODC promoter. We propose a model of pleiotropic gene regulation by androgen that requires a regulatory balance between androgen receptor and a transcription factor binding to the nonconsensus androgen response element.

[Observation of electronystagmogram in pilots under vestibular stimulation]

The relationship between electronystagmogram(ENG) and intensity of vestibular stimulation was observed in 62 pilots. 31 pilots received low intensity vestibular stimulation and the other 31 pilots received higher intensity vestibular stimulation. Electronystagmogram were recorded and analysed. The results showed that there was no relationship between the ENG parameters and stimulation intensity, but both slow phase and fast phase velocities and amplitudes were lower under Coriolis acceleration stimulus, while all of them were higher under angular acceleration and angular stimulations. It was also found that the fast phase amplitude of ENG was related to motion sickness symptoms of the subjects.

Single-stranded DNA-binding proteins and neuron-restrictive silencer factor participate in cell-specific transcriptional control of the NMDAR1 gene

Our previous studies revealed that a proximal region of the N-methyl-D-aspartate receptor 1 (NMDAR1) promoter is important for cell-type-specific expression. We have now explored the contributions of several regulatory elements to this specificity. Deletion of the neuron-restrictive silencer element partially relieved the suppression of promoter activity in C6 glioma and HeLa cells. An overlapping G(C/G)G/tandem Sp1-containing region crucial for both basal and nerve growth factor (NGF)-regulated promoter activity specifically bound nuclear proteins on its purine-rich sense strand. A faster migrating complex, single-stranded binding protein complex 1 (SBPC1), was highly enriched in HeLa cells, whereas a slower migrating complex, SBPC2, was enriched in PC12 cells. A high ratio of 2/1 complex correlated with a high level of promoter activity. NGF treatment of PC12 cells reduced SBPC1 but increased SBPC2. Competition experiments showed that the SBPC1 binding required a dG4 sequence and the SBPC2 needed a core of TG3A plus a 5'-flanking sequence. Single-stranded DNA encompassing TG3A and/or dG4 specifically suppressed cotransfected NMDAR1 promoter activity. UV cross-linking studies indicated that a 31.5-kDa protein mainly formed SBPC1, whereas SBPC2 contained several larger proteins. Our results suggest that neuron-restrictive silencer factor and single-stranded DNA-binding proteins may both play a role in cell-type specificity of the NMDAR1 gene, and the latter may also be involved in basal and NGF-regulated activity.

Development and application of a sandwich enzyme immunoassay for Glycyrrhizae Radix protein (GRP) using monoclonal antibodies

We have developed mouse monoclonal antibodies (anti-GRP mAb-1-5, all IgG1 sub-isotype mAbs) against Glycyrrhizae Radix protein (GRP), which was recently determined to be a marker protein of Glycyrrhizae Radix (GR). Among these, anti-GRP mAb-1 and 2 were found to recognize different epitopes on the GRP molecule, as demonstrated by ELISA analysis, and were used for the development of a sandwich enzyme immunoassay (SEIA) for GRP in traditional Chinese medicines (TCMs). The SEIA was based on the principle of binding an analyte to anti-GRP mAb2 coated on polystyrene microtiter wells, followed by immunoreaction with biotinylated anti-GRP mAb1 and horseradish peroxidase-streptavidin. The SEIA was specific to GRP in GRs, and showed no cross-reaction with any Leguminosae crude drugs other than GRs. This SEIA detected GRP with excellent reproducibility (coefficient of variation=5.9%), an EC50 of 11.5 ng/well and a detection limit of 0.1 ng/well. The present SEIA was about 10-times more sensitive in detecting GRP than the selected antibody enzyme immunoassay (SAEIA) for GRP previously developed using an antiserum to GR itself. Also, the SEIA has such a low assay background that it allowed us to detect a low concentration of GRP in Kyuki-tyoketsu-in-daiichi-kagen (KTIDK), a TCM consisting of only 2.7% GR. The GRP SEIA was simple, accurate, reproducible and may provide a general analytical method for the quality control of GR-based TCMs.

Isolation and characterization of phenoloxidase from egg masses of the gastropod mollusc, Biomphalaria glabrata

Previous studies have shown that phenoloxidase activity is present in the albumen gland and egg masses of Biomphalaria glabrata, and its potential role in egg formation in this snail has been proposed. In the present study, a phenoloxidase enzyme has been isolated from the supernatant of egg mass homogenates using a combination of hydrophobic interaction chromatography and gel filtration high-performance liquid chromatography (GF-HPLC). The isolated phenoloxidase eluted as a single peak of activity upon GF-HPLC (representing a 132-fold purification) and subsequently was detected as a single band with an estimated molecular mass of 35 kDa by SDS-PAGE analysis. Phenylthiourea-inhibitable mono- and diphenoloxidase activities were demonstrated for the isolated enzyme suggesting that both enzyme activities are associated with a single, tyrosinase-type molecule.

Phenoloxidase activity in the reproductive system of Biomphalaria glabrata: role in egg production and effect of schistosome infection

Infection by larval trematodes often causes a cessation of egg production in its molluscan intermediate host and is referred to as parasitic castration. Because phenoloxidase (PO) has been shown to be involved in egg formation in other invertebrate species, we investigated the role of PO in normal egg production in the snail, Biomphalaria glabrata, and the effects of Schistosoma mansoni infection on the PO pathway in this snail. Our data showed that PO activity in the albumen gland (AG) is initially expressed when snails reach a size of approximately 8 mm in shell diameter and continues to increase as snails grow, indicating a developmental link between snail size and AG PO expression. Egglaying was also shown to be coincidental with the onset of PO expression in the AG, thereby supporting a direct association between PO activity and egg production. In addition, exposure of snails to diethyldithiocarbamate (DDC), a PO inhibitor, affected normal in vivo egg production, as evidenced by a significant decrease in the numbers of eggs laid in DDC-treated groups compared to nontreated groups. Normal resumption of egg-laying activity in treated snails following withdrawal of the drug indicated that inhibition was reversible. Taken together, the results of our developmental and DDC-exposure studies provide strong support for a crucial role of PO in normal egg production in this animal. Finally, AG PO activities of infected and uninfected control snails were measured over the course of S. mansoni infection. Our results showed that both total and specific enzyme activities in the AG of infected snails were significantly decreased at 28 and 33 days postinfection (PI) when compared to those of control snails. Results of subsequent experiments assessing the effects of larval infection on L-tyrosine (PO substrate) levels in AG and ovotestis revealed a significant increase in the levels of this compound in both organs over the course of infection. It is concluded that AG PO activity is functionally linked to egg formation in normal snails and that a strong association exists between parasite-mediated decrease in AG PO activity and parasitic castration. However, from the data presented, a direct causal relationship linking infection, decreased PO, and castration has yet to be established.

[EGG and nausea under vestibular stimulus]

81 pilots were exposed to vestibular stimulus with Coriolis acceleration. They were divided into two groups, the first group consisted of 38 pilots with nausea symptoms, the second group 43 pilots without nausea symptom. Dominant frequency instability coefficient (DFIC), dominant power instability coefficient (DPIC), Tachygastria, Bradygastria and normal slow wave components (NSW) of the electrogastrogram (EGG) were analyzed. The results showed that Bradygastria and NSW of EGG were related to nausea symptom of pilots under Coriolis stimulation.

Polyamine-like immunoreactivity in rat neurons

The localization of polyamine (PA) pools in motor, sensory, and autonomic neurons and in the nerve cells of the hypothalamo-hypophysial system of rats was examined by immunocytochemical method using the monoclonal antibody ASPM-29 specific to spermine (Spm) and spermidine (Spd) fixed in situ. Strong PA immunoreactivity was found in the cytoplasm and dendrites of the large perikaryon of motor neurons in the anterior spinal column, in the Purkinje cells of the cerebellum, in the pyramidal cells of the cerebrum, in the nerve cells of the paraventricular and supraoptic nuclei in the hypothalamus, and in the nerve cells of the spinal and autonomic ganglions. No PA immunoreactivity was seen in the nucleus and nerve terminals of the neurons. The PA immunoreactivities in the motor and sensory neurons were characterized by clustered masses and blocks of immunoreactive cells. Irrespective of location, small and medium-sized neurons were weakly PA-positive. The glia cells, some stellite cells, and Schwann cells were almost completely PA-negative. These results may suggest that in neurons PAs are not transported axonally, but are located in conjunction with Nissl bodies (the rough endoplasmic reticulum), specified as sites for protein synthesis within cells.

Application of a licorice root specific protein to a general method for the assay of licorice root components in traditional Chinese medicines

A new fuzzy immunoassay method generally applied to ten Glycyrrhizae Radix (GR) preparations of four different botanical origins was studied. Four kinds of antisera were elicited in rabbits immunized with GRs of different botanical origins. The presence of the characteristic GR protein (GRP) was shown using Western blot analyses and selected antibody enzyme immunoassay (SAEIA) methods. A GRP was isolated from one of the GR specimens which was selected using SAEIA methods. The isolated GRP was heated to reduce its binding activity to an anti-GR serum. A new fuzzy SAEIA method generally applicable for assay of the extract of the ten GR specimens was developed using heat-treated GRP as the solid-phase antigen. The fuzzy SAEIA method was successfully applied for the detection and quantitative analysis of the GR component contained in traditional Chinese medicines.

Influence of a Rhamnolipid Biosurfactant on the Transport of Bacteria through a Sandy Soil

The objective of this study was to investigate the influence of an anionic rhamnolipid biosurfactant on the transport of bacterial cells through soil under saturated conditions. Three cell types with various hydrophobicities, i.e., Pseudomonas aeruginosa ATCC 9027, ATCC 27853, and ATCC 15442, were used in this study. In a series of experiments, columns packed with sterile sand were saturated with sterile artificial groundwater for 15 h, and then 3 pore volumes of (sup3)H-labeled bacterial suspensions with various rhamnolipid concentrations was pumped through the column. This was followed by 4 pore volumes of the rhamnolipid solution alone. The measured bacterial cell breakthrough curves were optimized by using an advection-dispersion transport model incorporating two-domain reversible sorption (instantaneous and rate limited) and with two first-order sink terms for irreversible adsorption. The influence of the rhamnolipid on the surface charge densities of the bacteria and the porous medium was also investigated. The results show that the rhamnolipid enhanced the transport of all cell types tested. For example, the rhamnolipid increased the recovery of the most hydrophilic strain, ATCC 9027, from 22.5 to 56.3%. Similarly, the recovery of ATCC 27853 increased from 36.8 to 49.4%, and the recovery of ATCC 15442, the most hydrophobic strain, increased from 17.7 to 40.5% in the presence of the rhamnolipid. The negative surface charge density of the porous medium was increased, while the surface charge density of the bacteria was not changed in the presence of the rhamnolipid. The model results suggest that the rhamnolipid predominantly affected irreversible adsorption of cells.

[Changes of electrogastrogram in pilots under vestibular stimulus]

The active electrogastrogram (EGG) of 81 pilots under vestibular stimulus was recorded and analysed by the method of running spectrum analysis. The subjects were randomly divided into group A and B. The results showed: that changes in dominant frequency instability coefficient (DFIC), dominant power instability coefficient(DPIC), tachygastria, bradygastria and normal slow wave components (NSW) of EGG occured under vestibular stimulus. These parameters of EGG may be used as indices to reflect the function of autonomic nervous system under vestibular stimulus. No difference of those parameters had been found between group A and B during the period of per-rotating, and the period of rotation.

A general enzyme immunoassay for the licorice root component contained in traditional Chinese medicines

The development and application of a new enzyme immunoassay for general assay of the Glycyrrhizae radix (GR) component in Chinese traditional medicines is described. Three commercial GR-based medicines, Tohoku kanzo (GRTK), Seihoku Kanzo (GRSEK) and Sinkyo kanzo (GRSK) were used as GR specimens. Anti-GRSK serum was elicited from rabbits immunized with GRSK fragments. The presence of common proteins as specific antigens of GR was first established by Western blot analysis of extracts of GRSK, GRSEK or GRTK using anti-GRSK. The specific antigens were applied to develop an ELISA for the assay of GR extract. Anti-GRSK was put in competition with a sample or standard GR extract and immobilized GRSK components in microtiter plate wells. The proportion of antibody binding to the solid-phase GRSK component was detected using an enzyme-labeled second antibody. The ELISA method was specific to GRSK extract and showed low sensitivity for the assay of GRTK extract. The technique of selected antibody enzyme immunoassay (SAEIA) was applied to develop a sensitive general assay method. Solid-phase GRTK extract, rather than immobilized GRSK extract, was used in the SAEIA. The SAEIA possessed the same quantitative working range of between 1 and 100 micrograms/ml for the assay of each extract of GRTK, GRSK and GRSEK. The SAEIA was successful in the detection and quantitative measurement of GR component contents in Chinese traditional medicines.

Nerve growth factor up-regulates the N-methyl-D-aspartate receptor subunit 1 promoter in PC12 cells

The N-methyl-D-aspartate (NMDA) subtype of glutamate receptor plays important roles in synaptic plasticity, the induction of long term potentiation, and excitotoxicity. Mechanisms governing the regulation of expression of its subunit genes remain largely unknown. The promoter of the essential subunit of the NMDA receptor heteromer, NMDAR1, contains DNA binding elements recognized by the nerve growth factor-inducible/early growth reaction factor (NGFI/Egr) family of transcription factors that are rapidly induced by neurotrophins, such as nerve growth factor (NGF). This study examined the effect of NGF on the activity of the N-methyl-D-aspartate receptor subunit 1 (NMDAR1) promoter/luciferase reporter constructs in PC12 cells, which contain the high affinity TrkA receptor for NGF and the low affinity p75(NTR) receptor for neurotrophins. NGF up-regulated the activity of the NMDAR1 promoter by 3-4-fold in a time- and dose-dependent manner. 5' deletional analysis of the promoter indicated that the responsive element(s) resides in the proximal region containing GSG and Sp1 sites. Mutational analysis of these sites revealed that both were important for NGF regulation. Transient expression of Egr-1 increased activity of the wild type promoter but failed to increase activity of a GSG mutant promoter. Other neurotrophins did not activate the promoter, while K-252a inhibited the action of NGF. These results suggest that the NGF effect is mediated by the high affinity NGF receptor, Trk A and that neurotrophin binding to the low affinity neurotrophin receptor, p75(NTR), alone does not affect the promoter activity. Our results suggest that NGF is able to up-regulate the activity of the NMDAR1 promoter and may play a role in controlling the expression levels of NMDA receptors.

[Observation on acupoint electric potential in pilots under vestibular stimulation]

To study the possibility of using acupoint electric potential as an index for evaluation of pilot's reaction to vestibular stimulation, electric potential was measured on both sides of left and right Neiguan points and Zusanli points in 80 pilots. Rotation chair was used as the method of stimulation. The results showed that changes of acupoint electric potentials were not significant (P >0.05) during 5 min uniform rotation. While the changes under head motion stimulation were significant (P<0.05 or 0.01) as compared with the pretest values. Relationship between symptoms and the corresponding acupoint potential changes remain to be studied further.

[The study of DSX-I type microcomputer autometic control injector system]

This paper studies the propulsive force of injector system controlled by 8031 single-chip microcomputer for Medical use By using one 8031 single-chip microcomputer as a microprocessor, the minimal autometic control system is constructed, which turns real-time control into reality. This product is a modern appliance used in diagnostic imaging medicine, in design of which the advanced instrument and electrical machinery are integrated into a unified structure. The clinic data demonstrate that the contrast medium can be injected to patients with rapidly and evenly. Dynamic CT Scanning can be intensified at any site of the body. x-ray dose exposed and lobour intensity to the operator can be decreased greatly, raise working efficiency.

Phenoloxidase activity in the reproductive system and egg masses of the pulmonate gastropod, Biomphalaria glabrata

Phenoloxidase (PO) activity in the albumen gland (AG) and egg masses (EM) of Biomphalaria glabrata was assessed using high-performance liquid chromatography combined with electrochemical detection and colorimetric techniques. Both AG and EM extracts catalyzed the hydroxylation of L-tyrosine (monophenol oxidase activity, MPO) and oxidation of L-dopa (diphenol oxidase activity, DPO). However, no PO activity was found in the ovotestis. Both MPO and DPO activities in AG and EM were significantly inhibited by 1-phenyl-2-thiourea and inactivated by boiling. Approximately 35% of MPO and 44% of DPO activities were detected in the soluble fraction of homogenized EM, in contrast to that of homogenized AG, which contained about 5% and 12%, respectively, of MPO and DPO activities. N-acetyl-dopamine, a diphenolic compound, enhanced the hydroxylation of tyrosine by the PO. The presence of both MPO and DPO activities also was confirmed by the accelerated accumulation of dopachrome during incubation of EM extracts with L-tyrosine in the absence of ascorbate. Temperature and pH optima for this enzyme were 30 degrees C and 7.5, respectively. The potential roles of PO in egg formation in B glabrata are discussed.

[The therapeutic effect of somatostatin on acute severe pancreatitis: a clinical contrastive observation]

We observed the effect of somatostatin on the treatment of acute severe pancreatitis and on the inhibition of pancreatic secretion. 21 patients with acute severe pancreatitis were divided into control group (n = 12) and treatment group (n = 9) according to the admission time from 1992 to 1995. The control group was treated regularly and the treatment group was given intravenous somatostatin within 24h of onset 6mg/day for 5-7 days besides the regular treatment. No significant difference was noted in the general conditions of the two groups on admission. The volume of stomach suction in the somatostatin treated group was lower than that in the controls on the 2nd, 3rd and 4th admission days (P < 0.05). The serum amylase level of the treatment group was lower than that of the controls. 12 complications occurred in the somatostatin treated group as compared with 17 in the control group (P > 0.05). The clinical cure time was 15.6 +/- 4.8 days for the treatment group and 21.5 +/- 7.6 days for the controls (P = 0.02). We consider that as a pancreatic secretion inhibitor somatostatin can control the disease process and shorten the clinical cure time to some extent if it is used on the early stage of acute severe pancreatitis.

A new method for the detection and quantitative measurement of the contents of trichosanthes root component composing Chinese traditional medicines

A new method was developed to estimate the content of Trichosanthes root (TR) component in two Chinese traditional medicines. Characteristic antigens of TR were separated from TR extract using rabbit antiserum specific for TR, a dried root tuber of Trichosanthes kirilowii. Two selected antibody enzyme immunoassay (SAEIA) methods, the SAEIA A for assay of TR extract and the SAEIA B for assay of karasurin A were used as detection methods for the separation of TR antigens. Using several column chromatographies, two kinds of TR antigens, a protein component and a glycan component, were separated from TR extract. A SAEIA C method for assay of TR glycan component was developed using biotinylated second antibody and peroxidase-labeled avidin as the detection method. The SAEIA C was also found applicable for specific assay of TR extract as well as for the contents of TR component present in two Chinese traditional medicines, prescriptions of which contained TR. Content of trichosantin, an abortifacient protein component of T. kirilowii, in both the medicines were also measured by applying the SAEIA B for assay of karasurin A. Little trichosantin was found in either medicine and the reason for this was determined.

Glucose metabolism and insulin release in mouse beta HC9 cells, as model for wild-type pancreatic beta-cells

Glucose metabolism and its relationship with glucose-induced insulin release were studied in beta HC9 and beta TC3 cells to identify and characterize key factors controlling the intermediary metabolism of glucose and glucose-induced insulin release. The beta HC9 cell line, derived from pancreatic islets with beta-cell hyperplasia, is characterized by a normal concentration-dependency curve for glucose-stimulated insulin release, whereas the beta TC3 cell line, derived from pancreatic beta-cell tumors, shows a marked leftward shift of this curve. Maximum velocity and the Michaelis-Menten constant of glucose uptake in beta HC9 and beta TC3 cells were similar, even though GLUT-2 expression in these two cell lines differed. In both cell lines, the kinetic characteristics of glucose usage, glucose oxidation, and glucose-induced oxygen consumption were similar to those of glucose phosphorylation, indicating that the kinetics of glucose metabolism from the glucose phosphorylation step in the cytosol to the mitochondrial process of oxidative phosphorylation are determined by the glucose-phosphorylating enzyme, that is, by glucokinase in beta HC9 cells and by hexokinase in beta TC3 cells. Thus beta HC9 cells provide an opportunity for the quantitative analysis of glucose metabolism, the associated generation of coupling factors, and other essential beta-cell functions involved in glucose sensing and insulin secretion.

Specificities of five kinds of antisera produced against crude drugs, pinella tuber, hoelen, glycyrrhizae radix, trichosanthes root and panax ginseng

Five kinds of rabbit antisera produced against five kinds of crude drugs, Pinella Tuber, Glycyrrhizae Radix (GR), Trichosanthes Root, Hoelen, and Panax Ginseng, and five kinds of extracts of the same crude drugs were prepared. Specificity of each antiserum was demonstrated by two immunological methods for analyses, the selected antibody enzyme immunoassay (SAEIA) and western blotting, and five crude drug extracts as specimens. Each crude drug extract contained characteristic antigen specific to the corresponding antiserum. Characteristic antigens were suggested as protein components. Characteristic antigen of the crude drug GR was separated from GR extract by three chromatographic procedures and a protein component was separated. The separated protein was successfully applied to develop a SAEIA method applicable for specific assays of both the separated protein and GR extract.

Determination of urinary acetylpolyamines by a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA)

A monoclonal antibody (mAb), ASPM-2, produced against N-(gamma-maleimidobutyryloxy)-succinimide (GMBS)-conjugated polyamine spermine [Spm; Fujiwara et al. (1994) Histochemistry 102, 397-404] was used for the development of an enzyme-linked immunosorbent assay (ELISA) for acetylpolyamines (Ac-PAs) in human urine. The ELISA is based on the principle of competition between an analyte and Spm-glutaraldehyde-bovine serum albumin conjugate-coated polystyrene microtiter wells for the mAb, followed by immunoreaction with biotinylated anti-mouse immunoglobulin and horseradish peroxidase-streptavidin. The ASPM-2 mAb showed strong immunoreaction with N1,N12-diacetylspermine (2Ac-Spm), N-monoacetylspermine (Ac-Spm), and N1-acetylspermidine (N1-Ac-Spd), the EC50 values being 29, 50, and 51 microM, respectively, but no cross-reaction with other PA-related compounds or amino acids. The method was used to measure urinary Ac-PA levels in healthy subjects and cancer patients, without pretreatment of the specimens, mean concentrations of 3.25 and 2.80 mumol per 24-h urine, respectively (as N1-Ac-Spd), being found. The ASPM-2 ELISA for N1-Ac-Spd, which is the PA most relevant to the analysis of human urine among the three Ac-PAs mentioned above, is specific and accurate, and can easily be used to analyze large numbers of specimens in parallel. It should thus have potential for studying the relationship between urinary N1-Ac-Spd levels and cancer.

Observation of light diffraction by time-resolved femtosecond correlation interferometry

We demonstrate time development of the diffraction of light waves from objects for what is to our knowledge the f irst time by using a new femtosecond correlation interferometry. This new dynamical optics method allows for the conversion of temporal information to space information with femtosecond resolution and has the potential to produce a time-resolved femtosecond movie for the visualization of light-wave propagation in space for scientific, biological, and medical applications.

The maximum information principle and the evolution of nucleotide sequences

The probability distributions of bases in nucleotide sequences are deduced from the maximum information principle by maximizing the entropy (due to random mutation of bases) under certain constraints (Markovian entropy, G + C content, etc, due to selection). Two formulations are given with respect to different selective constraints. The deviations of theoretical distributions from experimental data are lower than 10% for most sequences. It is shown that the Lagrange multipliers change from species to species systematically--i.e. selective constraints correlate with evolution.

Terabit speed retrieval of femtosecond accumulated photon echoes

An accumulated photon echo readout speed as fast as 27 Tbits/s was demonstrated by a new single-shot cross-correlation method for a femtosecond four-pulse packet stored by spectral hole burning in an octaethylporphine-doped polystyrene sample.

Spatial regulation of SpMTA metallothionein gene expression in sea urchin embryos by a regulatory cassette in intron 1

The SpMTA metallothionein (MT) gene of the sea urchin Strongylocentrotus purpuratus is restricted in its expression to the aboral ectoderm in gastrulae and pluteus larvae. The proximal 1.6 kb of the 5'-flanking region together with the 1.12-kb first intron of the SpMTA gene are sufficient for its correct cell-type specific expression in transgenic embryos. This restricted spatial expression is largely eliminated by deletion of an interior 405-bp region in the intron. Within this region is a 295-bp, genomically repetitive, transposon-like segment (Nemer et al., 1993), containing several sequence motifs highly homologous to posited regulatory elements in the promoters of other genes (Thiebaud et al., 1990). The P3A and P5 sites in this apparent regulatory cassette were shown through competition to bind with relatively high affinities the same nuclear factors, bound by their counterpart sites in the CyIIIa actin promoter.

Functional analysis of the proximal 5'-flanking region of the N-methyl-D-aspartate receptor subunit gene, NMDAR1

The NMDAR1 receptor subunit is a common subunit of N-methyl-D-aspartate receptors. We have previously characterized 3 kilobases (kb) of 5'-flanking sequence of the NMDAR1 gene and now report on the ability of this region to direct transcription of a reporter gene and on its interaction with nuclear proteins. The sequence 356 base pairs (bp) 5' of the first nucleotide of codon 1 was sufficient to express a luciferase reporter gene in rat PC12 pheochromocytoma cells. Additional sequences upstream of nucleotide -356 influenced the activity approximately 2-fold. A labeled 112-bp fragment (position -356 to -245) formed six complexes (C1A and -B, C2A and -B, and C3A and -B), grouped as three double bands, with nuclear extracts from PC12 cells. Competition with Sp1 oligonucleotides abolished formation of C2A and -B and C3A and -B complexes. Sp1 antibody recognized the C3A complex in supershift experiments. Prior immunoprecipitation of nuclear extracts with Sp1 antibody abolished formation CA2 and -B and C3A and -B complexes. Purified Sp1 protein alone did not form a C3A complex but potentiated its formation when PC12 nuclear extract was added. A GC-rich sequence in this fragment was protected from DNase I digestion by nuclear extract. These results suggest that a 356-bp sequence comprises the NMDAR1 basal promoter, and that NMDAR1 gene expression may be regulated by Sp1-like nuclear factors.

A clinical analysis of 38 patients with primary tracheo bronchial tumors

During a 17-year period, 38 patients with primary tracheobronchial tumors received surgical treatment in PUMC Hospital. Among the 38, 12 had low-malignancy tracheal tumors, 11 had benign tracheal tumors, 14 had low malignancy bronchial tumors and 1 had a benign bronchial tumor. Fifteen operations were performed on 12 patients with low-malignancy tracheal tumors, including local resection of the tumor and tracheal wall in 4 and curettage of the tumor plus electrical cauterization in 10. Postoperative radiotherapy was used as an adjuvant treatment in 8 patients with adenocystic carcinoma. Eight patients have survived for more than 5 years and 3 patients have survived for longer than 10 years postoperatively. All 11 patients with benign tumors received curettage of the tumor and were followed up for an average of 6.5 years. Among them, 9 are still alive. Of the 14 patients with low malignancy bronchial tumors, 5 underwent curettage of the tumor plus electrical cauterization through incision of the main bronchus or intermedial bronchus, and 7 underwent lobectomy or pneumonectomy. The authors conclude that the correct diagnosis rate can be increased by enhancing recognition of this disease and applying tracheal tomography and bronchoscopy.

c-fos promoter insensitivity to phorbol ester and possible role of protein kinase C in androgen-independent cancer cells

In exploring the biological basis of androgen-independent prostate cancer, we observed serum-independent growth of androgen-independent cells. We then discovered that in androgen-independent but not androgen-dependent cells, the serum-responsive gene c-fos is insensitive to phorbol esters, which regulate c-fos through the same mechanisms as serum. Transient expression of protein kinase C, through which phorbol esters activate c-fos, was sufficient to desensitize c-fos in androgen-dependent cells. Incubation in protein kinase C inhibitor chelerythrine killed androgen-independent but not androgen-dependent cells. This finding implicates protein kinase C activity in androgen-independent prostate cancer and suggests novel therapeutic strategies.

A mutant of protein phosphatase-1 that exhibits altered toxin sensitivity

A chimeric mutant was constructed in which a 4-amino acid region (GEFD, residues 274-277) of rabbit muscle protein phosphatase-1 was replaced with the sequence YRCG corresponding to residues 267-270 of rabbit protein phosphatase-2A. This was based on the findings of a gene mutation in okadaic acid-resistant cells which results in a Cys-->Gly conversion in protein phosphatase-2A. The YRCG mutant of protein phosphatase-1 was expressed and purified. The properties of the mutant enzyme were investigated in terms of its sensitivity toward several toxin inhibitors (okadaic acid, microcystin, nodularin, calyculin A, and cantharidic acid), as well as inhibitor-2. The mutant enzyme exhibited a gain of function in the form of a 10-fold increased sensitivity toward okadaic acid that suggests this region is involved in toxin binding. Significant changes in sensitivity to inhibitor-2 and several of the other toxins were also observed, indicating that these may have a common binding region.

Primary structure of human liver glycogen synthase deduced by cDNA cloning

The cDNA for human liver glycogen synthase was isolated by screening a human liver cDNA library constructed in lambda gt11. The full cDNA was 2912 bp in length. It coded for a protein of 703 amino acid residues with a molecular mass of 80.9 kDa. The number of amino acids was identical to and the deduced amino acid sequence homology was 92% that of the rat liver enzyme. The human and rat liver glycogen synthases are truncated by 34 amino acids compared to the human muscle enzyme, and by 32 amino acids compared to the rabbit muscle enzyme. The amino acid similarity between human liver and human muscle glycogen synthase was only 69%. It was least similar in the N and C terminal regions of the molecule. Two highly conserved regions are present in all published amino acid sequences for glycogen synthase, including those of the two yeast enzymes. These regions include the amino acid sequences from 201 to 400 and 501 to 600. This high conservation suggests that the catalytic site and the glucose-6-P and nucleotide allosteric sites are included in these regions.

Characterization of deletion mutants of the catalytic subunit of protein phosphatase-1

Deletion mutagenesis was used to define the core region of the catalytic subunit of rabbit muscle protein phosphatase-1. Deletions in the N terminus were found to lead to loss of expression. Deletions of up to 33 residues from the C-terminal region were tolerated, and the truncated enzymes were fully active. Deletion of an additional 21 residues led to loss of expression. Mutants which had had 33 and 25 residues deleted maintained specific activities that were comparable to those of the wild type enzyme. The response of these two deletion mutants to okadaic acid, microcystin, and inhibitor-2 was determined. Only slightly lower IC50 values were observed in all cases, showing that the C terminus itself does not play a major role in the binding of these inhibitors. The deletion mutants formed stable complexes with inhibitor-2 as shown by gel filtration. These studies provide unambiguous evidence that the extreme C-terminal region of protein phosphatase-1 is not directly involved in catalytic function or in the binding of inhibitor-2, microcystin, or okadaic acid, and they also establish that the first approximately 300 residues of the sequence constitute a sufficient core for protein phosphatase-1 catalytic functions.

Expression of recombinant inhibitor-2 in E. coli and its utilization for the affinity chromatography of protein phosphatase-1

The coding sequence for rabbit muscle protein phosphatase inhibitor-2 was inserted into the pET3a expression vector. This vector allowed the expression of recombinant inhibitor-2 at levels of ca. 1.5% of the soluble protein. A simple procedure allowed the purification of inhibitor-2 from Escherichia coli lysates. This involved heat-treatment, followed by chromatography on Blue-Sepharose and Q-Sepharose. Recombinant inhibitor-2 inhibited rabbit muscle protein phosphatase-1 with a potency similar to that reported for the wild type protein. The recombinant protein was coupled to CH-Sepharose and this support was found to bind the catalytic subunit of protein phosphatase-1 with high efficiency. A procedure for a single-step affinity purification of recombinant ppase-1 from E. coli lysates was shown to be feasible.