[Analysis of chlorogenic acid in sunflower cake by thin-layer chromatography]

The analytical method of chlorogenic acid in sunflower cake by thin-layer chromatography(TLC) was developed. With 36% acetic acid as mobile phase and on the polyamide film plate, the Rf value of chlorogenic acid was 0.61. The calibration curve was linear in the range of 0.05 microgram-0.6 microgram of chlorogenic acid with the detection limit of 0.025 microgram and the average recovery of 97.53%. The inter-plate accuracy of chlorogenic acid was 2.57%. With 70% ethyl alcohol as extracting solvent and 30 min of extraction time, the amount of chlorogenic acid in the extract, the residue amount of chlorogenic acid in the sunflower cake and the extraction rate were determined and calculated by applying this method. The optimal time of extraction was found.

The concentration of selected minerals and phytate in Malaysian Brachiaria decumbens

Samples of Brachiaria decumbens collected from 5 farms representing the Peninsular Malaysia were subjected to selected trace mineral and phytate analyses to explain the pathogenesis of B decumbens intoxication. Concentrations of Cu, Zn, Fe and Mo were comparable to other grasses while that of phytate was low. The molar ratios of Cu:Zn, Cu:Mo, and Cu:Fe warrant that Cu deficiency is involved in the toxicity of B decumbens. This might aggravate the development of photosensitization of unpigmented or lightly pigmented areas of affected animals. The Zn:phytate ratio could predispose to Zn deficiency during intoxication.

Effects of copper overload on hepatic lipid peroxidation and antioxidant defense in rats

The influence of copper (Cu) overload on hepatic lipid peroxidation and antioxidation defense capacity was studied by overloading rats with copper sulphate orally (500 mg Cu/kg bw) 5 d/w for 8 w. Malondialdehyde (MDA), Cu-Zn superoxide dismutase (SOD), and Se-glutathione peroxidase (GSH-Px) were measured in serum and liver homogenate at 2, 4 and 8 w of dosing. Liver Cu concentration and alanine aminotransferase (ALT) activity were also determined. As Cu loading progressed, there were multiparameter changes with significant ALT elevation, increased MDA concentrations in serum and liver homogenate, and dramatic declines of SOD and GSH-Px activities in erythrocytes and whole blood respectively, along with marked elevation of hepatic Cu in the Cu-dosed group. Excessive Cu accumulation in the liver depressed SOD and GSH-Px activities and resulted in high MDA in serum and liver homogenate due to the lipid peroxidation induced by the Cu overload.

Sensitive detection of a plant virus by electrochemical enzyme-linked immunoassay

The electrochemical enzyme-linked immunoassay increases the sensitivity of the detection of cucumber mosaic virus (CMV) by 5-fold compared with the spectrophotometric o-phenylenediamine (OPD) enzyme-linked immunosorbent assay (ELISA). The detection limit for the purified CMV is 1.0 ng/mL and the highest dilution ratio of the infected leaf sap is 1:5.0 x 10(4). The method is based on coupling the oxidation reaction of o-aminophenol (OAP)-H2O2 catalyzed by HRP-IgG conjugate with the electro-reduction of the enzymatic product. The enzymatic product 2-aminophenoxazine-3-one exhibits a sensitive second order derivative linear-sweep voltammetric response at the potential of -0.65 V (vs. Ag/AgCl) in pH 8.0 Britton-Robinson (B-R) buffer solution. So it can be applied to the detection of the plant virus with highly improved sensitivity.

[Analysis of 1-(2,6-dichlorophenyl)-2-indolone and related materials by high performance liquid chromatography]

The separation of 1-(2,6-dichlorophenyl)-2-indolone (DCI) and related materials in the synthesis of medical intermediate DCI from 2, 6-dichlorophenol and phenylamine was investigated with high performance liquid chromatography under different chromatographic conditions. The results showed that DCI and related materials were in baseline separation by using CLC-CN(150 mm x 6.0 mm i.d., 7 microns) as column, MeOH-H2O(6:4, V/V) as mobile phase and a flow-rate at 1 mL/min. A rapid, accurate and reproducible HPLC method for determining DCI was developed. Fine and crude DCI samples were detected, results showed that N-(2,6-dichlorodiphenyl)-chloracetyl amide (CBCC) was the main impurity in fine sample, and CBCC and 2,6-dichlorodiphenylamine were the main impurities in the crude one.

Assessment of decisions in the treatment of Helicobacter pylori-related duodenal ulcer: a cost-effectiveness study

AIMS

Many treatment trials for Helicobacter pylori have been reported but few have evaluated treatment in terms of both cost and effectiveness. It is important to find a therapy with a high eradication rate and low cost, especially in China. The aim of the study is to assess the efficiency of therapy for duodenal ulcers, including ulcer healing, H. pylori eradication and ulcer recurrence.

METHODS

Ninety-six consecutive patients with duodenal ulcers and H. pylori infection were randomly allocated into two groups: AMT group (amoxycillin + metronidazole + tagamet); OA group (omeprazole + amoxycillin). Side-effects were recorded during the treatment period. Endoscopic examinations were repeated at the 7th or 8th week to assess ulcer healing. Patients were followed up for 6 months and repeat endoscopy was performed. Ulcer healing rate, H. pylori eradication rate and ulcer recurrence rate were compared. All costs were recorded and a cost-effectiveness analysis was conducted.

RESULTS

In the AMT and OA groups, the ulcer healing rate was 83.7 and 93.5%, respectively (P = 0.27). The eradication rate of H. pylori was 65.1 and 69.6%, respectively and was significantly higher in patients with an ulcer diameter < or = 1 cm compared with those with an ulcer diameter > 1 cm, irrespective of treatment group. There was no difference in recurrence rate, duration of pain or the time lost because of the disease. Moderate or severe side-effects were found in 8.9% in AMT group and 6.5% in OA group. The cost of treatment for ulcer healing, H. pylori eradication and reduction in ulcer recurrence were all lower in the AMT group than in the OA group. Sensitivity analysis supported the result that AMT was more cost effective than OA.

CONCLUSIONS

The AMT therapy was more effective and less costly than the OA therapy, especially in patients with H. pylori-related duodenal ulcers < 1 cm diameter.

[Effects of L-malate, an inhibitor of glutamate decarboxylase, on learning and memory in mice]

Oral administration of L-malate 600 mg.kg-1 for 5 days before training can significantly promote memory acquisition, consolidation and retrieval, respectively, on anisodine-, chloramphenicol-, and ethanol-induced memory impairment in mice. Ketamine (8.5 mg.kg-1, i.p.), a selective NMDA receptor antagonist, was found to inhibit the anti-amnesic activity of L-malate. The glutamate (Glu) and GABA content in mice brain was measured by high-performance liquid chromatography with fluorescence detection. The content of GABA was shown to be decreased from 2.3 +/- 0.5 mumol.g-1 to 1.3 +/- 0.5 mumol.g-1 (P < 0.01), so the Glu/GABA ratio was increased significantly. These results suggest that the decrease of cerebral GABA level and the increase of Glu/GABA ratio is favorable to learning and memory.

Molecular epidemiology and variation of hepatitis B in recent immigrant families to Australia

Natural variation in hepatitis B virus (HBV) was studied in asymptomatic carriers originating from countries of high endemicity. HBV DNA was detected by dot blot and/or polymerase chain reaction (PCR) in 34 of the 184 members of 22 new immigrant families who agreed to be tested after one of their children had been found to have current or past hepatitis B in a school survey. PCR products from both the S and distal-X pre-C regions were sequenced. One vaccinated child had the classical "escape" mutation at amino acid position 126 in the S-gene and two other children and two adults had other substitutions at amino acid positions 133, 120, 165, and 159. Mutations were more frequent in the distal-X pre-C region and included two pre-C mutants and 13 other amino acid substitutions. The strains originating in the various countries were placed in almost identical groups by phylogenetic analysis using each amplicon, and determination of subtype by antigenic analysis gave the same result as sequencing. The S-data allowed recognition of three dominant strains within genotype B, while the distal-X pre-C data provided better discrimination between family groups. No change was found when the sequence of samples obtained for the study was compared with those collected from 14 of the children two years earlier. There was some evidence of horizontal spread in addition to vertical transmission. Reports of mutations of HBV in patients with severe or unusual clinical features should be interpreted with caution until the prevalence of the mutant in asymptomatic carriers has been determined.

A reproducible, simple, and sensitive high-performance capillary electrophoresis method for simultaneous determination of capreomycin, ofloxacin and pasiniazide in urine

Separation and determination of capreomycin (Cp), ofloxacin (Oflx) and pasiniazide (Ipa) in urine by high-performance capillary electrophoresis (HPCE) with 280 nm detection have been studied systematically. The calibration lines were linear in the range of 0.5 approximately 50 mg 1(-1), and the detection limits (S/N = 3) were 0.15, 0.20 and 0.10 mg 1(-1) for Cp, Oflx and Ipa, respectively. The recoveries for these materials from urine were higher than 93.5%. The accuracy and intra- and inter- day reproducibility of Cp, Oflx and Ipa were determined with satisfactory results. This method was successfully used for determining Cp. Oflx and Ipa in human urine.

Comparison of high-performance capillary electrophoresis and liquid chromatography on analysis of zinc 5-aminosalicylate dihydrate and related materials

Separation and determination of zinc 5-aminosalicylate dihydrate (ZASA) and related materials by high-performance capillary electrophoresis (HPCE) and liquid chromatography (HPLC) have been studied systematically. The R.S.D. of peak time and area and detection limits of materials were lower in HPLC compared to HPCE. HPCE and HPLC were used for determining ZASA and related materials in crude and treated ZASA using acid and heat, and similar results with both techniques showed the principal impurities in the crude ZASA were 5-aminosalicylic acid (ASA) and salicylic acid (SA), the compounds from ZASA decomposing under conditions of acid and heat were ASA, p-aminophenol and 5-benzeneazosalicylic acid.

Expression of multiple thyroid hormone receptor mRNAs in human oocytes, cumulus cells, and granulosa cells

Thyroid hormones have diverse effects on ovarian function. We examined the expression of thyroid hormone receptor (TR) mRNAs (including TRalpha-1, TRbeta-1, TRbeta-2, and c-erbAalpha-2 isoforms) in three types of cells from human follicles, and determined the concentration of free tri-iodothyronine (T3) present in human follicular fluid. Human failed-fertilized oocytes, granulosa (GC) and cumulus (CC) cells from patients of the in-vitro fertilization (IVF) programme at Alliant Hospital Fertility Center were used to detect TR mRNA expression using reverse transcription-polymerase chain reaction (RT-PCR) followed by Southern blot analysis. Human spermatozoa were also analysed to determine whether results obtained with CC would be affected by the presence of spermatozoa. beta-Actin mRNA was amplified in each cell type as a positive control for the RT-PCR. Our results show that human oocytes express TRalpha-1, TRbeta-1, TRbeta-2, and c-erbAalpha-2 mRNAs and that these same isoforms are expressed in both human granulosa cells and cumulus cells. No differences were detected in the apparent amounts of RT-PCR products when comparing GC with CC, suggesting a similar pattern of expression of these RNAs. beta-actin mRNA was detected in spermatozoa, but TRalpha-1 expression was not detectable. The concentrations of free T3 measured in follicular fluid were similar to, or slightly below, those in serum of euthyroid patients. These data demonstrated that several isoforms of TR mRNA are expressed in the human oocyte, and hence thyroid hormone may have direct affects on the oocyte, as well as on GC and CC. In addition thyroid hormone may have indirect effects on the oocytes via the CC.

Comparison of high performance capillary electrophoresis and liquid chromatography for the determination of acyclovir and guanine in pharmaceuticals and urine

High-performance capillary electrophoresis (HPCE) and high-performance liquid chromatography (HPLC) were developed and applied to the determination of acyclovir (ACV) and guanine (G) in pharmaceuticals. The comparison study showed that two methods gave comparable results in linear range, recovery and reproducibility. HPCE was used for the determination of ACV and G in urine; the recovery was better than 81.3% and the RSD was less than 4.4%.

Properties of practical oral liposome-Streptococcus mutans glucosyltransferase vaccines for effective induction of caries protection

Here we report the effectiveness of various liposome vaccines containing Streptococcus mutans glucosyltransferase (GTF) in protecting against dental caries after oral immunization. Rats were immunized by gastric intubation of the appropriate liposome vaccine at weaning and boosted 3 times. Rats were infected with S. mutans following initial immunization and fed cariogenic diet (Diet 305). Saliva and serum were collected during the study and assessed for antibody activity by enzyme-linked immunosorbent assay. Mandibles were removed on day 47 and assessed for S. mutans levels and then for caries. Animals immunized with sonicated, filtered and microemulsified GTF liposome preparations had decreased levels of dental caries compared with control animals given empty liposomes. Rats given dehydrated/rehydrated or purified liposomal GTF also had significantly less caries than control group (GTF alone). Because of economy, ease of preparation and efficiency in amount of antigen used, filtered, dehydrated/ rehydrated and purified liposomal GTF preparations are most practical for use in further assessing the efficacy of liposomal GTF in oral immunization.

Conjugation of cholera toxin or its B subunit to liposomes for targeted delivery of antigens

Several immunoadjuvant systems have been proposed to enhance mucosal immune responses of orally administered purified antigens. Cholera toxin (CT) or its B subunit (CTB) have been found to promote immune responses to antigens when they are co-administered via mucosal routes. Oral administration of antigens incorporated into liposomes has also been shown to result in enhanced mucosal immune responses. Here, we describe the covalent coupling of CT and CTB to small unilamellar liposomes for targeting these vesicles to Peyer's patch M cells, following their oral administration. Conjugation was done by means of a thioether bond using succinimidyl(4-N-maleimidomethyl)cyclohexane-1-carboxylate to modify the dipalmitoylphosphatidyl-ethanolamine constituent of liposomes and N-succinimidyl-3-(2-pyridyldithio)propionate to thiolate CT or CTB. The biological activity of CT or CTB bound to liposomes was confirmed by a hemagglutination assay using GM1-enriched human erythrocytes. Furthermore, oral administration of CT-conjugated liposomes to rats resulted in the induction of serum IgG and salivary IgA anti-CT responses. CT-conjugated liposomes may prove to be a useful system for targeted delivery and immunoenhancement of weakly immunogenic antigens.

Oral immunization of humans with dehydrated liposomes containing Streptococcus mutans glucosyltransferase induces salivary immunoglobulin A2 antibody responses

Seven healthy adult volunteers each ingested an enteric-coated capsule containing 500 micrograms of Streptococcus mutans glucosyltransferase (GTF) in dehydrated liposomes for 3 consecutive days. The immunization regimen was repeated 28 days later. Parotid saliva and plasma were collected prior to and at a weekly interval for 8 weeks following the first immunization for analysis of anti-GTF activity by enzyme-linked immunosorbent assay. The levels of immunoglobulin A1 (IgA1) and IgA2 anti-GTF activities increased in the parotid saliva from 5 of 7 individuals after immunization. Increases in the mean level of IgA1 and IgA2 anti-GTF responses peaked on day 35 (77% and 175% increase over baseline, respectively), although variation was noted in the kinetics and subclass of responses between individuals. No salivary IgG or IgM responses were observed. Low plasma IgM, IgG and IgA anti-GTF responses were seen in immunized subjects. Oral immunization with a dehydrated liposome-protein vaccine was effective in inducing a secretory IgA antibody response, which was primarily of the IgA2 subclass. These results provide the first evidence for the use an oral dehydrated liposome-protein vaccine in humans.

[Relation of effects of matrine on rat vasa deferens to activation of calcium channels]

Effective mechanisms of matrine (Mat) in contraction were observed in isolated rat vasa deferens. Mat caused a strong concentration-dependent contraction of vasa deferens, and this contraction was competitively inhibited by prazosin (Pra, 10 mumol.L-1) and nifedipine (Nif, 50 nmol.L-1), with depression of maximal responses. Their pA2 value was 5.1 and 9.29, respectively. The contraction was also inhibited by verapamil (Ver, 1 mumol.L-1) with depression of maximal responses; but this antagonism was noncompetitive. Its pD2 value was 6.07. Mat promoted CaCl2-induced contraction of vas deferens. The effect of Mat was enhanced in proportion to increase in concentrations of CaCl2. Mat markedly strengthened KCl-induced contraction of vas deferens. The results suggest that one of the mechanisms of the contractive effects of Mat within a certain range of concentrations was related to the activation of the calcium channel.

[Study on surgical resection length of esophageal carcinoma: an analysis of 2325 cases of the resected samples with esophageal carcinoma]

The paper studied the relationship between the resected length above and below the esophageal carcinoma and positive rate of the residual carcinoma in the resected rims. The positive rates of the carcinoma were 65.0%, 17.2%, 12.3%, 10.6%, 6.7%, 5.8%, 4.0%, 3.1%, 2.0%, 0.9% and 0% respectively while the length of the resected esophagus above and below the carcinoma was 1-10 cm and 10 cm respectively. The results shown that it would be the best for all patients with esophaged carcinoma to resect esophagus more than 10 cm in length above and below the carcinoma respectively.

Neonatal hearing impairment complicated by neonatal pneumonia. Application of auditory evoked potentials in neonatology

A group of 433 neonates with pneumonia were studied through the monitoring of audiology on the basis of epidemiology in perineonatal hearing impairment and applied auditory evoked potentials. The results showed that 29 cases had a threshold of more than 30 dBnHL in primary auditory brainstem response test (6.7%), and 19 cases with threshold, more than 40 dBnHL in primary 40Hz-auditory event related potential (40Hz-AERP) test (4.4%). The follow-up between the 3rd and 12th month after the initial test demonstrated that 12 cases had hearing impairment to various degrees.

[Blood and urine prostaglandin E2 and prostaglandin F2 alpha in patients with chronic gastritis and peptic ulcer]

The blood and urine prostaglandin E2 (PGE2), Prostaglandin F2 alpha (PGF2 alpha) in 106 cases of chronic gastritis and peptic ulcer were investigated by RIA. Meanwhile, the relationship among PGE2, PGF2 alpha and the Syndromes of TCM were approached. The result showed: In comparing with the normal control, the blood and urine PGE2 of 106 cases were obviously higher (P < 0.01), but PGF2 alpha was not (P > 0.05). The urine PGE2 and PGF2 alpha of moderate gastritis were markedly higher than those of mild gastritis (P < 0.05), but there were no significant difference between blood PGE2, PGF2 alpha of moderate gastritis and those of mild gastritis (P > 0.05). The blood PGE2, PGE2/PGF2 alpha ratio of Dampness-Heat in Spleen-Stomach Syndrome and the blood PGE2/PGF2 alpha ratio of incoordination between Liver and Stomach Syndrome were higher than those of Spleen Stomach Deficiency Syndrome in all the cases (P < 0.05). Compared with the normal control, both the decreased amplitude of blood PGE2/urine PGE2 and increased amplitude of blood PGF2 alpha/urine PGF2 alpha ratio showed as following: Spleen-Stomach Deficiency Syndrome > incoordination between Liver and stomach Syndrome > Dampness-Heat in Spleen-Stomach Syndrome. This study suggested: (1) There was a close relation between PGE2 and chronic gastritis and peptic ulcer; (2) There was no correlation between blood PGE2, PGF2 alpha and urine PGE2, PGF2 alpha; (3) PG was possibly a useful objective parameter to the Syndrome Differentiation in TCM.

Purification and characterization of two DNA helicases from calf thymus nuclei

Two DNA helicases from calf thymus nuclei have been purified and characterized. The two proteins, designated as nuclear DNA helicase I and II, were copurified on Bio-Rex 70, DEAE-Sepharose, phosphocellulose and subsequently separated from each other on a heparin-Sepharose column. Final purification of DNA helicase I was achieved on single-stranded DNA-cellulose and that of DNA helicase II on ATP-agarose. On denaturing polyacrylamide gels, nuclear DNA helicase I displayed two polypeptide bands of 170 and 200 kDa; nuclear DNA helicase II also consisted of two bands, in this case of 100 and 130 kDa. Both enzymes catalyzed the unwinding of a DNA primer from a single-stranded DNA template but had different nucleotide requirements for their energy supply. While nuclear DNA helicase I preferred to hydrolyze ATP or dATP to support its unwinding activity, nuclear DNA helicase II could utilize all four rNTPs or dNTPs, though ATP or dATP were still preferred to other nucleotides. ADP, AMP, or adenosine 5'-O-(thiotriphosphate) could not be used by either enzyme in the unwinding reactions. A divalent cation was essential for activity of both enzymes. Nuclear DNA helicase I required 3-5 mM Mg2+ or 1 mM Mn2+ for optimal unwinding. In contrast, nuclear DNA helicase II displayed high activity even at very low concentrations of Mg2+. Nuclear DNA helicase I was stimulated by NaCl, KCl, or potassium acetate up to concentrations of 150 mM; in contrast, nuclear DNA helicase II was strongly inhibited at salt concentrations over 75 mM. Both DNA helicases had an associated ATPase activity. However, while the ATPase activity of nuclear DNA helicase I was stimulated only in presence of single-stranded DNA, the ATPase activity of the nuclear DNA helicase II was stimulated by single-stranded DNA and, even more efficiently, by RNA. Finally, the translocation of both DNA helicases had a polarity from 3' to 5' with respect to the single-stranded DNA template to which the enzymes were bound. A comparison of these DNA helicases with the other reported mammalian DNA helicases will be given. The significance of the association of the two DNA helicases during the process of the purification will be discussed.

Characteristics of giant cells and factors related to the formation of giant cells in myocarditis

Giant cell myocarditis is a serious and frequently fatal inflammatory heart disease of which the etiology remains unknown. In the present study, we investigated the origin of multinucleated giant cells in myocarditis with the use of an experimental model. We also examined the factors relating to the formation of giant cells in myocarditis. Severe myocarditis characterized by the appearance of multinucleated giant cells was induced in Lewis rats by immunization with cardiac myosin in complete Freund's adjuvant. Two types of giant cells, foreign body giant cell-like and myocytelike, were observed in this myocarditis. Immunohistochemical studies revealed that both types of multinucleated giant cells were stained with OX42 and ED1 (macrophage markers) and were not stained with anti-desmin antibody and HHF35 (markers for muscle fibers). Therefore, it is likely that multinucleated giant cells in this myocarditis are derived from macrophages. During the course of the disease, the appearance of multinucleated giant cells was restricted to a period corresponding with the fulminant phase of inflammation. When the severity of the disease was modulated by immunization with various doses of the antigen, multinucleated giant cells appeared only in severe myocarditis after inoculation of a large dose of the antigen. Administration of immunoadjuvants also affected the formation of giant cells. Most of the rats injected with cardiac myosin in complete Freund's adjuvant developed giant cell myocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of central effects produced by intracerebral injection of glutamic acid, quisqualic acid, and kainic acid]

Icv glutamic acid (Glu), quisqualic acid (QA) and kainic acid (KA) significantly increased spontaneous activity of mice in photecell box, and induced dose-dependent rise of blood pressure in anesthetized rats. Their intensities were arranged in the order of KA greater than Glu greater than QA. In mice step-through test Glu 0.1 micrograms icv improved learning and memory; KA 1 ng had no evident effect; and QA 0.1 microgram impaired learning and memory, which were also confirmed by step-down test in normal mice. Therefore, the non-NMDA (N-methyl-D-aspartate) receptor subtype might be different from the NMDA receptor subtype in the action of learning and memory.

[Relationship between facilitatory effect of piracetam on memory and glutamate receptors]

By Y-maze method, repeated administrations of sodium glutamate 400 mg.kg-1.d-1 ip for 5 d before training remarkably reduced the number of trials from 45.3 +/- 15.5 of the control to 20.0 +/- 6.9 in mouse of anisodine-induced memory impairment. Ketamine (10 mg.kg-1, ip), a selective NMDA receptor antagonist, inhibited the anti-amnesic activity of piracetam. The number of memory errors was raised from 1.9 +/- 1.5 to 2.6 +/- 2.1 in mouse step-down test. Piracetam 500 mg.kg-1.d-1 ip for 3 d caused a decrease in mouse brain glutamate content and glutamate/GABA rate from 7.07 +/- 0.83 mumol.g-1 to 5.69 +/- 0.60 mumol.g-1 and 4.98 +/- 0.63 to 4.52 +/- 0.81, respectively. These results suggest that facilitatory effect of piracetam on memory may be mediated by glutamate receptor.

Short intussusception valves prevent reflux after jejunal interposition bilioduodenal anastomosis

Short whole circumference and semi-circumference intussusception valves were created in interposition cholecysto-jejunal-duodenal conduits in pigs to determine which method best prevented gastrointestinal reflux into the biliary tract. Following intravenous injection of 99 mTc-HIDA the time interval for its excretion from the liver and appearance in the duodenum was not different in either whole or semi-circumference valve animals or in controls without valves. After intragastric administration of 99 mTc-DTPA the relative radioactivity of gallbladder contents (reflux) in the cohort without valves was significantly higher than in both cohorts with valves. Animals with semi-circumferential valves in turn had significantly higher levels of nuclide than those with whole circumference valves. Reflux was observed grossly in 100% of animals without valves, in 20% of those with semi-circumference valves, and in no animals with whole circumference valves. This study indicates that both whole and semi-circumference intussusception valves placed in jejunal biliary conduits allow unimpeded flow of bile into the gastrointestinal tract. Whole circumference valves are more effective for prevention of reflux than semi-circumferential valves.

Accuracy of DNA primase

The base-pairing fidelity of DNA primase from calf thymus was studied in vitro by using a misinsertion assay based on synthetic polydeoxynucleotide templates. With poly(dT) as template, GMP misinsertions occurred with a frequency of one error per 1600 correctly incorporated nucleotides, while UMP and CMP were inserted with a frequency of 1/300 and 1/500, respectively. Accuracy with poly(dC, dT) as template was 1/200 for the misinsertion of UMP, and 1/300 for the misinsertion of CMP. Thus, DNA primase is the least accurate polynucleotide-synthesizing enzyme known. The results are discussed in terms of an obvious necessity for a priming mechanism at the beginning of DNA synthesis.

Somatic cell hybrid and long-range physical mapping of 11p13 microdissected genomic clones

Microdissection and microcloning of banded human metaphase chromosomes have been used to construct a genomic library of 20,000 clones that is highly enriched for chromosome 11p13 DNA sequences. Clones from this library have been mapped on a panel of human-rodent somatic cell hybrids that divides the region from distal p12 to proximal p14 into seven physical intervals, A total of 1500 clones has been isolated, 250 clones have been characterized, and 58 clones have been mapped. Six of the clones were used to complete a long-range physical map of 7.5 megabases through the region. Two of the clones are localized to the Wilms tumor (WT) region, three are localized to the aniridia (AN2) region, and two are localized to the region between WT and AN2. The library represents DNA sequences spanning a distance of approximately 13 x 10(6) base pairs, with an average density of one clone per 37,000 base pairs.

[Antagonism of Zn2+ on nootropic action of piracetam in mice]

In mouse step-down test, the memory impairments of acquisition, consolidation and recognition were induced by anisodine, chloramphenical and ethanol, respectively. Piracetam 100 mg/(kg.d) ip for 5 d improved the anisodine-induced impairment of learning. ZnSO4 5 mg/(kg.d) po for 5 d did not improve the 3 impairments. Memory impairments were enhanced by a combined administration of ZnSO4 and piracetam in these 3 models. These results were confirmed by Y-maze method in normal mice.

[Observation on the therapeutic effect of external counterpulsation in progressive muscular dystrophy]

Twelve cases of progressive muscular dystrophy were treated with external counterpulsation (ECP). The therapeutic results of ECP were shown as follows: markedly improved, 3 cases: improved 6 cases: slightly improved 2 cases and no effect 1 case after ECP Clinical, improvement in various degrees developed in all the cases. Dystrophy muscle enlarged in 11 of the 12 cases. Gastrocnemius muscles softened and lessened in 3 of 8 cases. CPK markedly decreased in 9 of 10 cases. In electron microscopic examination the ultrastructure of the diseased muscles was found to have obviously improved, the structure and form of most mitochondria returned to normal, and collection of glycogen was rarely seen.

Observation of the curative effect of external counter-pulsation therapy on progressive muscular dystrophy

External counter-pulsation therapy was applied to 12 cases of progressive muscular dystrophy with effects of varying degressive markably effective in 3 cases, effective in 6, improved in 2 and no effect in one. In 11 of 12 cases the atrophic muscles became normal, in 3 of 8 cases the gastrocnemius softened and in 9 of 10 cases creatine phosphokinase greatly reduced. Electron microscopy found that the ultramicrostructure of the diseased muscles greatly improved, the structure and morphology of most mitochondria became normal, and glycogenesis disappeared.

The application of leukocyte adherence inhibition assay to patients with colorectal cancer. Comparison with serum level of carcinoembryonic antigen and sialic acid

Antitumor immune response to colorectal cancer extracts was tested by leukocyte adherence inhibition (LAI) assay. Of 38 colorectal cancer patients, 26 (68.4 percent) were LAI positive. The sensitivity of LAI assay was found to be inversely related to the stage of the disease. In contrast, 2 of 50 (4 percent) healthy individuals, 2 of 37 (5.4 percent) patients with nonmalignant gastrointestinal diseases, and 2 of 32 (6.3 percent) patients with malignancies other than colorectal cancer were LAI positive. Serum carcinoembryonic antigen (CEA) and serum sialic acid (SA) also were determined in 38 colorectal cancer patients. Using LAI assay in combination with CEA determination could improve the detection rate of colorectal cancer.

[Effects of cerebral GABA level on learning and memory]

In step-down tests, icv GABA 0.1 micrograms (3 min before training) or ip amino-oxyacetic acid 20 mg/kg (1.5 h before training) both significantly impaired memory acquisition in mice. But semicarbazide (ip 110 mg/kg 3.5 h before training), an inhibitor of GABA synthesis, improved the anisodine-induced impairments of learning. The effects of GABA was also enhanced by aminooxyacetic acid. The results suggest that the increase of cerebral GABA contents is unfavourable to learning and memory.