[Analysis of collagen in burned skin with SDS-polyacrylamide gel electrophoresis]

Type III collagen was determined by SDS-polyacrylamide gel electrophoresis in normal rabbit skin, skin with deep II degrees burn 72h after injury, skin one month after burn, and healed burn 1.5 month after injury. Results showed that there was a reduction of type III collagen in the process of healing of burn wounds.

Regulation of human clotting factor IX cDNA expression in transgenic mice

To study the expression of human clotting factor IX cDNA in transgenic mice, which is an essential work on gene therapy for hemophilia B, 3 recombinant constructions containing different lengths of human clotting factor IX cDNA have been introduced into the cultured cells. All of the recombinant constructions were found to be expressed well in vitro. They were then microinjected into the male pronuclei of the fertilized mouse eggs respectively for generating transgenic mice. Unfortunately, none of them was expressed in any transgenic mice. These results show that the expression of the human clotting factor IX cDNA in the transgenic mice can be determined by cis regulatory element(s). As compared with the results from other related works, it is suggested that the cis regulatory element(s) is resided in the 5'-end non-coding region.

[Effect of 153Sm-EDTMP on hematopoiesis and vital organs of 93 patients with bone tumor]

In the present study data on blood cell count, serum biochemistry, electrolyte, enzyme and vital organs of 93 patients with bone tumor or metastasis were investigated before and after treatment with 153Sm-EDTMP. The results showed that, 7 days and 30 days after the administration of 153Sm-EDTMP (< 29.6 MBq) (0.8 mCi/kg), the levels of hemoglobin, WBC lymphocyte count, and the liver and kidney function of all patients were not significantly different from the baseline data before treatment (P > 0.05). Although at 7 days, there was a declination of the granulocyte count, it returned to normal at 30 days (P > 0.05). The platelet count was significantly decreased (0.05 > P > 0.01). at 30 days after the administration of 153Sm-EDTMP. Thirteen patients received 74-185 MBq (2-5mCi/kg) and their myelo biopsies at 3 and 18 months showed no sign of acute or chronic toxicosis.

The Arabidopsis MADS-box gene AGL3 is widely expressed and encodes a sequence-specific DNA-binding protein

The Arabidopsis AGL3 gene was previously identified on the basis of sequence similarity to the floral homeotic gene AGAMOUS (AG), which encodes a protein with a conserved MADS domain that is also found in human and yeast transcription factors (SRF and MCM1, respectively). Analysis of newly isolated full-length cDNA clones as well as genomic clones indicates that AGL3 is indeed a MADS-box gene with a general intron-exon structure similar to other plant MADS-box genes. However, unlike the others, which are expressed specifically in flowers, AGL3 is expressed in all above-ground vegetative organs, as well as in flowers, but not in roots. Furthermore, since AGL3 is MADS-domain protein, it is likely that it is also a DNA-binding protein regulating transcription. To characterize AGL3 as a DNA-binding protein in vitro, we expressed the AGL3 protein in Escherichia coli, and characterized its DNA-binding properties. We show that AGL3 binds to sequences which resemble the target sequences of SRF and MCM1, and have determined the consensus sequence to which AGL3 binds using random oligonucleotides. These results suggest that AGL3 is a widely distributed DNA-binding protein, which may be involved the transcriptional regulation of genes in many cells.

Synthesis of (17R)- and (17S)-17-hydroxy-14, 15-secoandrost-4-en-15-yn-3-one and the X-ray crystal structure of the (17S)-diastereomer

(17R,S)-17-Hydroxy-14,15-secoandrost-4-en-15-yn-3-one has been shown previously to be a mechanism-based inactivator of rat liver 3 alpha-hydroxysteroid dehydrogenase. This manuscript describes the synthesis of this diastereomeric 14,15-secosteroid from [2S-(2 alpha,4a alpha,4b beta, 10a beta)]- 1,2,3,4a,4b,7,9,10,10a-decahydro-2,4b-dimethyl-7-oxo-2-phenanth renecarboxylic acid methyl ester. The separation of this diastereomeric 14,15-secosteroid into (17R)- and (17S)-17-hydroxy-14,15-secoandrost-4-en-15-yn-3-one was accomplished by HPLC separation of the (S)-1-[(4-methylphenyl)sulphonyl]-2-pyrrolidinecarboxylate derivatives on a silica column. The crystal structure of (17S)-17-hydroxy-14,15-secoandrost-4-en-15-yn-3-one was then solved by X-ray diffraction analysis to establish unambiguously the absolute configuration of the diastereomeric 14,15-secosteroid.

Spatial frequency multiplexing of optical fiber sensor arrays

A new technique to multiplex interferometric optical fiber sensors in the spatial frequency domain is reported that is especially suitable for applications in smart structures and materials. It can greatly reduce the number of fiber-optical devices in the network system and employs a high-speed noniterative phase-retrieval technique to trace the phase changes in each fiber sensor. In addition, the sensor system operation is virtually immune to the polarization fading problem without the need for polarization-maintaining fibers or any special devices. A preliminary investigation based on computer simulation has been undertaken to assess the system's feasibility and performance.

Repeated radial keratotomy

38 cases 59 eyes received repeated radial keratotomy in which the secondary incisions were performed along the scars of old incisions. The average follow-up after the reoperation was 13 months. Before reoperation, the mean spherical equivalent of the refraction was -3.78D and the mean keratometry was 40.15D. 13 months after the reoperation, the mean spherical equivalent of the refraction decreased by 2.30D, and the mean keratometry decreased by 2.04D. After the reoperation, the mean uncorrected visual acuity increased by 5 lines. There was no relationship between the therapeutic effect of the reoperation and the degree of initial myopia or pre-reoperative keratometry. The repeated radial keratotomy can decrease the degree of astigmatism and its complications are few.

Regulation of prostaglandin H synthase 1 and 2 in MyoD transfected cells

Exponentially growing DD-1 cells (differentiation-defective cells) synthesize prostaglandins, while exponentially growing MyoDD-1 cells (differentiation-competent cells; DD-1 cells transfected with the myogenic regulatory gene MyoD) synthesize little or no prostaglandins and have reduced levels of prostaglandin H synthase-1 RNA [J. R. Wolf et al., 1993, Exp. Cell Res. 207, 439]. However, MyoDD-1 cells have the capability of synthesizing prostaglandins in response to serum stimulation of serum-deprived cells. The serum stimulation of prostaglandin biosynthesis is associated with transient increases in both prostaglandin H synthase-2 RNA and protein. DD-1 cells and MyoDD-1 cells are similar with respect to prostaglandin biosynthesis and expression of prostaglandin H synthase-2 following serum stimulation of serum-deprived cells. In contrast, the expression of prostaglandin H synthase-1 is higher in DD-1 cells as compared to MyoDD-1 cells under all culture conditions. Thus, expression of myogenic regulatory genes is associated with the differential regulation of prostaglandin H synthase-1 and prostaglandin H synthase-2.

Suppression of potato spindle tuber viroid replication and symptom expression by mutations which stabilize the pathogenicity domain

Nucleotides within the pathogenicity domain of potato spindle tuber viroid (PSTVd) are known to play an important role in regulating symptom expression, but the underlying molecular mechanism is unknown. In order to determine more precisely how structural features within the pathogenicity domain regulate symptom expression, we have characterized a series of mutations that progressively stabilize premelting region 1 and the rest of the "virulence modulating" region. The structural effects of these mutations were monitored by temperature gradient gel electrophoresis of circularized RNA transcripts, and their biological effects were assessed by quantitative bioassays in tomato. Closure of a 4-nucleotide loop within the premelting region 1 virtually abolished PSTVd infectivity, especially when a nearby 2-nucleotide loop was also closed. Although RNA transcripts containing less stabilizing mutations were readily infectious, none of the four single and one double substitutions examined were stably maintained in vivo. The pattern of spontaneous, apparently compensatory sequence changes observed in the progeny suggests that PSTVd variants with less stable secondary structures enjoy a selective advantage. Mutations which stabilize the pathogenicity domain of PSTVd in vitro also suppressed symptom expression, but at least one other mutation having no obvious structural effects was associated with a similar phenotype. Conformational stability appears to be only one of several factors regulating PSTVd replication and pathogenicity.

Susceptibility to hepatocellular carcinoma is associated with genetic variation in the enzymatic detoxification of aflatoxin B1

Aflatoxin B1 (AFB1) has been postulated to be a hepatocarcinogen in humans, possibly by causing p53 mutations at codon 249. AFB1 is metabolized via the phase I and II detoxification pathways; hence, genetic variation at those loci may predict susceptibility to the effects of AFB1. To test this hypothesis, genetic variation in two AFB1 detoxification genes, epoxide hydrolase (EPHX) and glutathione S-transferase M1 (GSTM1), was contrasted with the presence of serum AFB1-albumin adducts, the presence of hepatocellular carcinoma (HCC), and with p53 codon 249 mutations. Mutant alleles at both loci were significantly overrepresented in individuals with serum AFB1-albumin adducts in a cross-sectional study. Mutant alleles of EPHX were significantly overrepresented in persons with HCC, also in a case-control study. The relationship of EPHX to HCC varied by hepatitis B surface antigen status and indicated that a synergistic effect may exist. p53 codon 249 mutations were observed only among HCC patients with one or both high-risk genotypes. These results indicate that individuals with mutant genotypes at EPHX and GSTM1 may be at greater risk of developing AFB1 adducts, p53 mutations, and HCC when exposed to AFB1. Hepatitis B carriers with the high-risk genotypes may be an even greater risk than carriers with low-risk genotypes. These findings support the existence of genetic susceptibility in humans to the environmental carcinogen AFB1 and indicate that there is a synergistic increase in risk of HCC with the combination of hepatitis B virus infection and susceptible genotype.

Additive activation of yeast LEU4 transcription by multiple cis elements

The LEU4 gene of Saccharomyces cerevisiae and the enzyme encoded by LEU4, alpha-isopropylmalate synthase, occupy a special position in amino acid metabolism. alpha-Isopropylmalate synthase catalyzes the first committed step in leucine biosynthesis. However, the reaction product alpha-isopropylmalate is not only an intermediate in the leucine biosynthetic pathway, but also functions as co-activator of at least six genes, both within and outside of the leucine pathway. The metabolic importance of alpha-isopropylmalate appears to be reflected in the surprisingly multifaceted regulation of LEU4 expression. This report describes an analysis of functional cis elements in the LEU4 promoter. Five such elements were identified. Three distal elements, designated UASLEU, GCE-A, and GCE-B, are responsible for regulation by the regulatory proteins Leu3p and Gen4p, respectively. The incremental activation of LEU4 by these elements is additive and independent. In addition, two proximal elements were localized. One of these conforms to the TATA consensus sequence and exhibits high affinity for TATA binding protein. The other element shows strong sequence identity with the Bas2p binding site and appears to be involved in basal and phosphate-mediated regulation of LEU4.

Synthesis of (17R)- and (17S)-17-hydroxy-14, 15-secoandrost-4-en-15-yn-3-one and the X-ray crystal structure of the (17S)-diastereomer

(17R,S)-17-Hydroxy-14,15-secoandrost-4-en-15-yn-3-one has been shown previously to be a mechanism-based inactivator of rat liver 3 alpha-hydroxysteroid dehydrogenase. This manuscript describes the synthesis of this diastereomeric 14,15-secosteroid from [2S-2 alpha,4a alpha,4b beta,10a beta)]- 1,2,3,4a,4b,7,9,10,10a-decahydro-2,4b-dimethyl-7-oxo-2-phenanth renecarboxylic acid methyl ester. The separation of this diastereomeric 14,15-secosteroid into (17R)- and (17S)-17-hydroxy-14,15-secoandrost-4-en-15-yn-3-one was accomplished by HPLC separation of the (S)-1-[(4-methylphenyl)sulphonyl]-2-pyrrolidinecarboxylate derivatives on a silica column. The crystal structure of (17S)-17-hydroxy-14,15-secoandrost-4-en-15-yn-3-one was then solved by X-ray diffraction analysis to establish unambiguously the absolute configuration of the diastereomeric 14,15-secosteroid.

[Effects of leech and ground beetle powder on hemorheology and blood lipid of ischemic stroke]

In order to improve blood supply for the brain, restore the functions of the cerebral cells and the limbs, and increas the curative rate, the leech (Hirudo nipponica and ground beetle Eupolyphage sinensis), powder (LGBP) to the patients according to the principle of promoting the blood circulation to remove the stasis was administered, and the clinical observation and experimental study was conducted. Its effects were compared with those of Western medicines. The results showed that after medication of LGBP, the blood flow of brain significantly increased, the hypoxia was improved, blood viscosity and blood lipid were lowered and thrombosis was inhibited in vitro or in vivo. No toxic side-effects caused by LGBP was found.

Excited-state enhancement of the third-order nonlinear optical susceptibility of nonether polyphenylquinoxaline

The microscopic third-order nonlinear-optical susceptibility gamma(-omega; omega, omega, -omega) of a conjugated polymer, nonether polyphenylquinoxaline, was observed to be enhanced by two times from 355-nm optically pumped excited-state populations under the condition of unsaturated pumping. We studied the time evolution of the enhancement and verified by a fluorescence measurement that the excited-state enhancement of gamma(-omega; omega, omega, -omega) is proportional to the population of the excited state.

[Rectal administration of ash bark]

A TLC-densitometric method was applied to determine aesculin in rabbit blood. The best way for ash bark rectal administration was found by orthogonal design [L4(2(3))]. The two routes of administration (per rectal, P.O.) were compared by bioavailabilities and the result indicated that per rectal was better than P.O. Modified isolated rectum-bag method was applied successfully to finding the best way for rectal administration of ash bark.

[Effect of dietary and/or exercise intervention on incidence of diabetes in 530 subjects with impaired glucose tolerance from 1986-1992]

577 subjects with impaired glucose tolerance (IGT) aged from 25 to 74 were identified in Daqing in 1986. They were stratified according to BMI > or = 25 (352 cases) and BMI < 25 (225 cases) and subjects in each BMI group were randomly assigned to four groups: control, diet, exercise and diet plus exercise intervention groups (each group had similar age, BMI, fasting and 2-hour plasma glucose level). A six-year follow up study indicated that incidence of diabetes per 100-person-year was 15.7, 10.0, 8.3 and 9.6 in control, diet, exercise and diet plus exercise groups respectively. Proportional hazards regression analysis controlling for differences in baseline factors (age, sex, BMI and plasma glucose) showed that diet and/or exercise intervention were inversely related to the incidence of diabetes. The better the actual intervention, the less the incidence of diabetes. Therefore, the results strongly indicate that diet and/or exercise intervention treatment are effective methods to reduce the incidence of diabetes.

Receptor-mediated activation of recombinant Trpl expressed in Sf9 insect cells

The Drosophila proteins, Trp and Trpl, are suggested to be cation channels responsible for depolarization of the receptor potential associated with stimulation of insect photoreceptor cells by light. Consistent with this hypothesis, we recently showed that recombinant Trpl forms Ca(2+)- and Ba(2+)-permeable non-selective cation channels when expressed in Sf9 cells using the baculovirus expression vector. As Trpl may be activated in the photoreceptor cell after stimulation of phospholipase C, we hypothesized that a similar regulation of recombinant Trpl may be observed in the Sf9 cell after activation of heterologous membrane receptors linked to Ca(2+)-signal-transduction pathways. To test this hypothesis, Ca2+ signalling was examined in Fura-2-loaded Sf9 cells infected with baculovirus containing cDNA for the M5 muscarinic receptor alone (M5 cells) or in cells co-infected with both M5 and Trpl-containing baculoviruses (M5-Trpl cells). Addition of carbachol (100 microM) to M5 cells produced an increase in cytosolic free Ca2+ concentration ([Ca2+]i) (mean +/- S.D.; n = 17) from 101 +/- 20 to 762 +/- 178 nM which declined to a sustained elevated level of 384 +/- 102 nM after 3 min. The sustained component was eliminated by removal of extracellular Ca2+ or by addition of La3+ or Gd3+ (10 microM). In M5-Trpl cells, basal [Ca2+]i increased as a function of time after infection. To evaluate the contribution of Ca2+ influx to the overall profile observed, Ba2+, a Ca2+ surrogate that is not a substrate for the Ca2+ pump, was used. The increase in basal [Ca2+]i seen in M5-Trpl cells was associated with an increase in basal Ba2+ influx. Addition of carbachol to M5-Trpl cells at 30-36 h after infection produced a large increase in [Ca2+]i to a sustained value of 677 +/- 143 nM. This change in [Ca2+]i was (1) blocked by atropine, (2) attenuated in the absence of extracellular Ca2+, and (3) relatively insensitive to La3+, but blocked by Gd3+ in the 0.1-1 mM range. In the presence of 10 microM Gd3+ to block the endogenous-receptor-mediated Ca(2+)-influx in M5-Trpl cells. In sharp contrast increase in Ba2+ influx in M5-Trpl cells. In sharp contrast, neither Ca2+ nor Ba2+ influx through Trpl was affected by thapsigargin, a selective inhibitor of the endoplasmic reticulum Ca(2+)-ATPase pump.(ABSTRACT TRUNCATED AT 400 WORDS)

Decreased levels of adenylate cyclase contribute to the down-regulation of beta-adrenergic signal transduction in the salivary glands of the non-obese diabetic (NOD) mouse

Stimulation of salivary gland secretion by treatment of NOD mice with the beta-adrenergic receptor agonist, isoproterenol, was previously shown to cause a lower accumulation of intracellular cAMP than that found that in BALB/c controls (Hu et al., 1994, Am. J. Physiol. 266: G433). This was, in part, due to decreased levels of beta-adrenergic receptor localized in the plasma membrane. In the present investigation, basal levels of cAMP in the salivary glands of NOD mice were found to be similar to controls, while direct stimulation of adenylate cyclase by incubation of isolated membranes with forskolin showed a reduced cAMP accumulation in NOD mice versus BALB/c control mice. Using direct [3H]-forskolin binding, it was determined that the plasma membranes of NOD mice salivary glands contain reduced levels of membrane-associated adenylate cyclase.

[Research on rectal administration of bark of official Magnolia]

Fluorescence assay was applied to the determination of magnolol in rabbit blood, and the best way to administer the bark of official magnolia per rectal was established by orthogonal test. Then the two routes of administration were compared by AUC of magnolol and per rectal was found better than P.O. In addition, the modified isolated rectum-bag method was applied successfully to the research on rectal administration of bark of official magnolia.