[The effect of plasmids on the resistance of E. coli to phages]

The introduction of the ColV, I-K94 or R124 plasmid into Escherichia coli K12 resulted in resistance to certain phages. Derivatives of E. coli carrying the plasmid R124 and ColV, I-K94 were resistance to the phages T4, Mel comparing with the plasmid-free parent and the plasmid ColV, I-K94 conferred resistance to the phage Tull*. It suggested that an envelope change caused by the plasmids might be responsible for the resistance because most of the phages fell to absorb to the plasmid-bearing E. coli cells.

Treatment of 100 cases of nerve deafness with injectio radix salviae miltiorrhizae

100 cases of nerve deafness were treated with Injectio Radix Salviae Miltiorrhizae by i.v. drip, and additional drugs that promoted blood circulation were used according to symptom differentiation. Results were 28 cases cured, 45 cases improved, and 27 cases failed, for a total effective rate of 73%.

Effects of a benz[e]indene on gamma-aminobutyric acid-gated chloride currents in cultured postnatal rat hippocampal neurons

Benz[e]indenes (BIs) are tricyclic molecules that can be envisioned as steroids without an A-ring. Because certain steroids are known to alter gamma-aminobutyric acid (GABA) responses in central neurons, we examined the effects of a substituted BI resembling 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-OH-DHP) on GABA-gated chloride currents in cultured postnatal rat hippocampal neurons. The compound, BI-1, reversibly potentiated GABA currents at concentrations of > 10 nM, with an EC50 value of 0.2 microM. BI-1 increased the apparent affinity of GABA for its receptor, decreasing the GABA EC50 from 9 microM to 3 microM. BI-1 had no effect on the shape of the GABA current-voltage relationship and did not alter the GABA reversal potential. The effects of BI-1 were not altered by benzodiazepine or picrotoxin site antagonists. At concentrations up to 10 microM, where maximal effects on GABA currents were seen, BI-1 did not directly activate a membrane current. This contrasts with the effects of 3 alpha-OH-DHP, which activated chloride currents at concentrations that were subsaturating for GABA potentiation. These results suggest that the BIs may be useful for determining the mechanisms by which steroids potentiate GABA responses and directly gate chloride channels.

Ultrastructural study of cerebral arteries in Moyamoya disease

The cerebral arteries in seven cases of Moyamoya disease, demonstrated by angiography were observed by light, transmission and scanning electron microscopy. In two cases, the lumen of the terminal portion of the internal carotid artery was completely occluded by proliferated connective tissue. The characteristic pathologic change was extensive destruction of the smooth muscle cells and the elastica interna. Degeneration and necrosis of smooth muscle cells were obvious in the media. Many condensed organelles and other elements of cellular destruction were dispersed throughout the interstitium. The media was thinned. The proliferated smooth muscle cells in the intima showed the same destructive changes as in the media. The elastica interna was excessively infolded and was thickened or thinned, disrupted or disintegrated in some segments. Identical, but less severe and more localized changes were seen in three middle cerebral arteries (M2 and M5 segments) and two collateral arteries at the base of brain. These changes suggest that Moyamoya disease is a progressive disorder characterized by repeated destruction of smooth muscle cells occurRing over a long time period. The pathogenesis of these changes is discussed.

Functional changes in salivary glands of autoimmune disease-prone NOD mice

Lymphocytic infiltration of the salivary glands in autoimmune diseases results in the human condition known as xerostomia. To date, an animal model for the autoimmune development of salivary gland dysfunction has yet to be described. With the autoimmune diabetes-prone nonobese diabetic (NOD) mouse strain, salivary flow rates and total saliva protein concentration in both male and female mice showed a progressive decline in the nondiabetic and diabetic states. Submandibular gland weight decreased from control mice with the progression to onset of diabetes in both sexes, whereas the weight of the parotid gland remained unchanged. The level of saliva amylase activity, when measured relative to unit volume, decreased in nondiabetic males but increased upon onset of diabetes to control values. When expressed relative to protein concentration in saliva, amylase activity was depressed for both sets of NOD mice but was higher upon diabetes onset than in the nondiabetic animals. In females a similar pattern was observed except that amylase activity expressed relative to unit volume was not significantly depressed in either set of NOD mice. The same observations were made for glandular amylase activity. The level of epidermal growth factor (a product of the ductal cells of the submandibular gland) was reduced over 500- and 18-fold for male and female diabetic mice, respectively. Sodium dodecyl sulfate polyacrylamide gels of total saliva showed changes in mobility as well as concentration of several proteins in the NOD mice.(ABSTRACT TRUNCATED AT 250 WORDS)

[Purification, characterization and reverse cholesterol transport of human serum apolipoprotein A-IV]

In order to study the function of apoA-IV, human serum apoA-IV was isolated and purified. LDS was isolated with NaBr density gradient ultracentrifugation and then incubated with intralipid according to the method of Weinberg and Scanu. Protein complex containing apoA-IV was obtained. The apo-IV was purified from protein complex by preparative SDS-PAGE, electroelution and removal of SDS. ApoA-IV thus prepared gave a single band on SDS-PAGE with a MW of 46 kD. Amino acid composition and isoelectric focusing pI (5.27 and 5.47) of apoA-IV were similar to those reported in the literature. The effects of apoA-IV and liposome (apoA-IV: DMPC) on cholesterol efflux from hum skin fibroblast were studied. There was no significant difference (P > 0.5) between apoA-IV and control but a very significant difference (P < 0.001) between liposome (apoA-IV:DMPC) and control, suggesting that liposomes (apoA-IV:DMPC) play a role in reverse cholesterol transport. The results may offer a new approach for the prevention and treatment of atherosclerotic coronary heart disease.

Effects of l-stepholidine on synaptosomal Ca(2+)-ATPase and subcellular calmodulin in rat striatum

Our results showed that l-stepholidine (l-SPD) inhibited basal Ca(2+)-ATPase activity in rat striatal synaptosomes with an IC50 of 31.5 mumol.L-1, suggesting its interaction with Ca2+ transport. l-SPD inhibited also calmodulin (CaM)-activated basal Ca(2+)-ATPase in a concentration-dependent manner. A complete reversal of CaM activation of Ca(2+)-ATPase was observed with l-SPD 10 mumol.L-1. The activity of synaptosomal Ca(2+)-ATPase and membrane-bound CaM level were decreased in haloperidol (1 mg.kg-1.d-1, ip) and l-SPD (5, 10, and 30 mg.kg-1.d-1, ip) treated rats for 7 and 14 d, respectively. But the activity of Ca(2+)-ATPase and membrane CaM level were increased after treatment with the same of doses haloperidol and l-SPD for 21 d. During the treatments with haloperidol and l-SPD cytosolic and nuclear CaM levels were not altered. These results suggest that l-SPD may modulate the release and synthesis of dopamine (DA) and the negative feedback regulation of presynaptic DA receptors by altering Ca2+ and CaM regulating processes in the central dopaminergic nervous system.

[The toxicity of herbicide Asulam]

We conducted a series of toxicity tests and short-term mutagenic assays of Asulam and 40% (W/V) sodium Asulam. It was found that the LD50 of Asulam with acute oral toxicity was 30000 mg/kg for mice, and the LD50 of sodium Asulam for mice and rats were equal (8250 mg/kg). The cumulative coefficient of sodium Asulam in Wistar rats was 9.42. None died from sodium Asulam absorbed via skin. Negative results were obtained in Ames test, Bacillus subtilis repair test and the micronucleus test. There was no significant difference between the control group and the treated groups in the chromosomal aberration rates of spermatogonia and primary spermatocytes of mice testis. The results indicated that Asulam should be regarded as a substance of low toxicity and low accumulation. No mutagenicity was observed in our experiment.

Activity of primate putamen neurons is selective to the mode of voluntary movement: visually guided, self-initiated or memory-guided

The aim of this report was to investigate the neural processes of movement initiation and control in which the basal ganglia play an essential role. Single-neuron activity was recorded in the putamen of monkeys performing learned arm movements initiated in three different modes: sensorially guided, internally-timed self-initiated and memory guided. There were no significant differences in the magnitude and timing of both prime mover and supporting muscle activity between the three modes of movement. Over half of the task-related neurons showed strong activity in one of the three modes of movement initiation, but were only slightly activated in the other two modes. No clear preference for a particular movement mode was evident in the population of putamen neurons as a whole. These results are consistent with the hypothesis that there are heterogeneous groups of neurons in the putamen, and that each group of neurons participates in retrieving a different kind of information required for movement based on either external sensory events or on internally stored information.

[Effects of artificial cultured Panax notoginseng cell on cardiovascular system]

Alcoholic extract from artificial cultured Panax notoginseng cell (SCC) ip has been found conducive to increasing the resistance of mice to anoxia. In vitro it helps to increase the outflow of coronary vessels, decrease the heart rate, inhibit the constriction of aortic strip stimulated by nor-epinephrine and relax spasmodic constriction of ileum smooth muscles markedly. SCC powder suspension on po administration can contract bleeding and coagulation time. The pharmacologic activities of SCC are similar to those of crude Panax notoginseng.

[Study of 315 pedigrees with idiopathic mental retardation by segregation analysis]

315 pedigrees with idiopathic mental retardation (MR) have been studied by complex segregation analysis. The results show that there is no major gene effect in the mild MR, but in the medium and severe MR there are major gene effect. The pattern of inheritance of the medium MR may be codominant and the penetrance of the dominant gene is 0.91. The mode of inheritance of the severe MR may be recessive and probably without sporadic cases.

An improved ELISA with linear sweep voltammetry detection

An improved ELISA combined with linear sweep voltammetry detection of p-nitrophenol generated by an enzyme has been investigated in this study. p-nitrophenol, produced from alkaline phosphatase catalysing p-nitrophenyl phosphate, yielded an oxidative peak at 1.06 V (vs. Ag/AgCl) with a wax-impregnated tubular graphite anode. Without separation, the small three-electrode system was directly inserted in the well of an ELISA plate for detection. The detection limit for p-nitrophenol was 1 x 10(-6) M, lower than that obtained by measuring the absorbance of p-nitrophenol. The feasibility of utilizing linear sweep voltammetry as a detection scheme was demonstrated by determining metallothionein, granulocyte-colony stimulating factor and Xenopus laevis keratin using the above new system. The method was simple, reproducible and much more sensitive than traditional spectrophotometry.

2-Amino-3-(methylamino)propanoic acid (BMAA) bioavailability in the primate

2-Amino-3-(methylamino)-propanoic acid (BMAA) is a low potency excitatory amino acid present in the cycad plant that has been proposed as a factor in the high incidence of amyotrophic lateral sclerosis-parkinsonism dementia (ALS-PD) in the western Pacific region. We employed stable isotopic forms of BMAA to assess the oral bioavailability of this compound in cynomolgous monkeys (n = 3). The stable isotope labeled BMAA ([15N]-BMAA) was injected i.v. at the same time that the unlabeled compound was administered orally. Both forms of BMAA were then quantified in a 48h urine sample by gas chromatography-mass spectrometry (GC/MS). Following oral dosing, 80% of the administered BMAA was absorbed into the systemic circulation; thus, oral bioavailability was high and other routes of administration could not result in significantly higher circulating levels of BMAA for a given administered dose.

Antagonism of l-stepholidine on D2 receptor-mediated inhibition of synaptosomal adenylate cyclase in rat corpus striatum

In the presence of Sch 23390 0.1 mumol.L-1, dopamine (DA) inhibited the activity of synaptosomal adenylate cyclase (AC) isolated from rat striatum in a concentration-dependent manner with IC50 value of 2.2 mumol.L-1. The maximal inhibition corresponded to a 51% decrease of basal enzyme activity and was obtained at DA 100 mumol.L-1. The inhibitory effect of DA was reversed by selective D2 receptor antagonist spiperone 10 mumol.L-1. N-0437, a selective D2 DA receptor agonist also inhibited the activity of AC in the manner similar to that of DA. Both the inhibitions induced by DA and N-0437 were antagonized by l-stepholidine (l-SPD). However, in the presence of Sch 23390, l-SPD alone also inhibited the activity of AC by 29% and 33% at the concentrations of 10 and 100 mumol.L-1, respectively. The inhibition of l-SPD on AC activity was significantly antagonized by spiperone. In the presence of Sch 23390, both DA and N-0437 increased the activity of high affinity GTP phosphohydrolase in striatal synaptosomes. The increases of GTP phosphohydrolase activity stimulated by DA and N-0437 were completely reversed by l-SPD 100 mumol.L-1. These results suggest that l-SPD antagonizes or reverses the D2 receptor-mediated inhibition of AC activity through affecting the regulation of Gi (inhibitory guanine nucleotide-dependent protein) on D2 receptor-coupled AC and therefore affects the negative feedback of presynaptic DA receptors. Moreover, the inhibition of AC activity induced by l-SPD alone may provide a useful biochemical index for dual action of l-SPD.

Electroretinographic oscillatory potentials in diabetic retinopathy. An analysis in the domains of time and frequency

The oscillatory potentials of the electroretinogram in dark and light adaptation were evaluated by Fourier transform in 87 diabetics and 74 age-matched controls. The study consisted of four groups: normal control, no observable diabetic retinopathy, background diabetic retinopathy and proliferative diabetic retinopathy. A reduction in the amplitude of each oscillatory potential, the summed amplitudes, the area and the total power of the oscillatory potentials as well as delayed implicit time of each oscillatory potential peak in dark and light adaptation could be found in patients with background diabetic retinopathy and proliferative diabetic retinopathy. The amplitude of oscillatory potential 4 in dark adaptation and the total power of the oscillatory potentials in light adaptation seemed to be affected in patients with no observable diabetic retinopathy. The implicit time of oscillatory potential 2 in dark adaptation was valuable to distinguish between patients with no observable diabetic retinopathy and background diabetic retinopathy.

[A case-control study on risk factors of female hypertension in Tianjin City]

A pair matched case-control study was conducted in 301 pairs female patients with essential hypertension and their controls. The data was analysed by the multiple conditional Logistic regression. The results showed the risk factors associated with hypertension were: body weight (OR = 1.17, 95% CI: 1.12-1.23), the family history of hypertension (OR = 2.18, 95% CI: 1.49-3.21) the family income (OR = 0.73, 95% CI: 0.56-0.94), heart rate (OR = 2.30, 95% CI: 1.41-3.76). OR for the age of menarche was significantly different before and after being adjusted by body weight. There were no relationship between the age of menopause, the age of the first birth, parties, oral contraceptive use or smoking status and hypertension. The paper suggested that the difference of prevalence of hypertension in male and female over 45 years old cannot be explained by menopause or the factors on birth in women.

A histological, ultrastructural and immunohistochemical study of superficial temporal arteries and middle meningeal arteries in moyamoya disease

Pathologic changes in superficial temporal arteries (STA) and middle meningeal arteries (MMA) biopsied from 15 patients with moyamoya disease (MD) who had undergone cerebro-temporal arterio-synangiosis were studied histologically, ultrastructurally and immunohistochemically. The main pathologic features were: proliferation of smooth muscle cells (SMCs) and thickening of the intima, degeneration and destruction of SMCs in the media and intima, and the presence of condensed organelles in necrosed SMCs or the interstitium among SMCs, or both outside and within the elastica interna (EI). The EI had become thin, porous, fragmented and was even absent in some segments. These changes are different from those of other forms of angiopathy, but identical with those at the ends of internal carotid arteries (ICA) reported by us previously, being pathognomonic for MD. These changes in the STA and MMA reveal that MD involves not only the ICA but also the intra- and extracranial branches of external carotid arteries. The medial necrosis of SMCs seems to be the primary injury of the arterial wall in MD. STA tissue blocks from two cases of MD were stained immunohistochemically. By electron microscopy, IgG-, IgM-, and C3-positive granules were observed on the ER of endothelial and intimal cells. Further studies on more cases are needed to determine whether an immunoreaction has occurred in these arteries.

Uterine influences on the formation of subnormal corpora lutea in seasonally anestrous ewes

The hypothesis that subnormal luteal function after induced ovulation in anestrous ewes was the result of uterine influences exerted during the periovulatory period was tested. Crossbred ewes (n = 27) in seasonal anestrus were induced to ovulate by administration of 12 doses of 250 ng of LHRH at 2-h intervals, followed immediately by a bolus injection of LHRH (250 micrograms; d 0). Ewes were unilaterally hysterectomized on either d -3 (PRELHRH) or 2 (POSTLHRH). Daily blood samples were collected and assayed for progesterone (P4) and 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM). All ewes were slaughtered on d 10, and corpora lutea (CL) were collected, weighed, and assayed for concentration of P4. All ewes that ovulated exclusively in the ovary ipsilateral to the remaining uterine horn had a transient increase in plasma P4 of 2 to 3 d (short luteal phase). In ewes with at least one CL in the isolated ovary, elevated plasma P4 was maintained after hysterectomy but was consistently lower (P less than .05) in POSTLHRH ewes than in PRELHRH ewes. Concentrations of PGFM did not differ between treatments. The CL ipsilateral to the remaining uterine horn weighted less (P less than .01) and contained less P4 (P less than .01) than contralateral CL. These data confirm the hypothesis that premature regression of subnormal CL is uterine-dependent in a local fashion. Presence of the uterus during the follicular and(or) early luteal phase inhibited subsequent luteal function in seasonally anestrous ewes.

Resistance to trimethoprim in Haemophilus influenzae

The mechanisms of resistance to trimethoprim in eleven U.K. clinical isolates of Haemophilus influenzae were studied. The levels of dihydrofolate reductase (DHFR) activities in crude extracts from four resistant wild-types were similar to those in susceptible controls. However, activities in extracts from the other seven resistant wild-type isolates, and transformants of two of these, were at least triple those in the sensitive strains. Resistance to trimethoprim was also selected for in vitro during prolonged exposure to the drug and was associated with increased levels of DHFR specific activity in the mutants. DHFR enzymes were, however, still very susceptible to inhibition by trimethoprim. Activities in four extracts, including one from a transformant of a resistant mutant, were reduced by at least 45% following incubation with 10(-8) M trimethoprim. The results suggested that overproduction of the chromosomal DHFR enzyme may be the resistance mechanism in some organisms. The much lower DHFR activities measured in extracts from other resistant isolates may reflect synthesis of chromosomal enzymes that have reduced susceptibility to trimethoprim.

Effects of hyperlipidemic sera and lipoproteins on prostacyclin synthesis by rabbit aortic smooth muscle cells

The effects of various hyperlipidemic sera and serum high density lipoproteins (HDL) and low density lipoproteins (LDL) on the synthesis of prostacyclin (PGI2) by rabbit aortic smooth muscle cells in culture were studied. Data show that HDL induces a dose-dependent increase in the synthesis of PGI2 in smooth muscle cells. Although LDL at comparable cholesterol concentrations to HDL also results in an increase of PGI2 synthesis in a dose-dependent pattern, the extent of this increase is much less than that induced by HDL. Smooth muscle cells incubated with hyperlipidemic serum and hyperlipidemic + aspirin-treated sera synthesize less PGI2 as compared to normal serum, but cells incubated with hyperlipidemic + 8501-treated serum generate an amount of PGI2 similar to that seen with normal serum. We suggest that 8501 may directly stimulate PGI2 synthetase in smooth muscle cells.

Clinical and experimental observations on treatment of peptic ulcer with wei yang an (easing peptic-ulcer) capsule

The therapeutic effects of peptic ulcer treated with cimetidine and Wei Yang An were compared clinically and experimentally by the double blind method. Results showed that the effects of the two are similar, but the long-term effect of Wei Yang An was better. Wei Yang An was also good for most cimetidine resistant ulcers, with few side effect. Animal experiment showed that Wei Yang An inhibited the ulcers.