[Clinical study of superoxide dismutase in recurrent aphthous ulceration]

Activity of superoxide dismutase (SOD) was determined in erythrocytes obtained from 74 patients with recurrent aphthous ulcerations (RAU) and 100 healthy individuals. The results showed that activity level of SOD in RAU was significantly lower as compared with that in the controls (P less than 0.01). The activity of SOD in 30 cases of RAU at interval period was elevated on reexamination, but it was still lower than that in the controls (P less than 0.01). There is evidence that damage of superoxide radicals (O.2) and decrease of activity of SOD may play important roles in the pathogenesis of RAU. A random double-blind, placebo-controlled, cross-over trial on membrane SOD was carried out in 40 patients with RAU. The results demonstrated that the effective rate of SOD was 90%, being markedly higher than that of placebo. It is suggested that membrane SOD, as a topical medicine, could increase the concentration of SOD on the ulcerous surfaces, prevent O.2-induced injury, decrease capillary permeability, relieve inflammation and improve cure of ulcer.

[Identification of Yi nationality's secret recipe for treating snakebite]

The authors have investigated and found an effective secret recipe for the treatment of snakebite in Mabian, an autonomous county of the Yi nationality in Sichuan Province. Morphologic identification has shown that the recipe is composed of the herb of Pedicularis muscicola and the rhizome of Polygonum viviparum in the ratio of one to one. To facilitate further application, popularization and improvement of the recipe, its histological characteristics have also been studied microscopically.

Sign of chi((3)) in polysilane polymers

The signs of the third-order optical nonlinear susceptibility chi((3)) of polysilane have been determined to be negative at 532 nm and positive at 1064 nm from single-beam Z-scan measurements. The small and positive chi((3)) at 1064 nm arises from the bound-electronic process. The negative chi((3)) at 532 nm is attributed to two-photon absorption resonance transition.

[Analysis of Trace elements in processed products of Pinellia ternata (Thunb.) Breit]

This article reports the detecting result of trace elements in processed products of Pinellia ternata and of the contents of As, Hg, Pb in the products processed with sulfur. The result shows that all the processing procedures are necessary and safe.

Gas chromatographic determination of aldicarb and its metabolites in urine

A method is described for the determination of aldicarb and its metabolites (the sulphoxide and sulphone) in urine by gas chromatography with flame photometric detection (GC-FPD). The sample was concentrated with a column containing activated charcoal and Florisil, and then eluted with dichloromethane-acetone (1:1, v/v). The aldicarb and aldicarb sulphoxide in the eluate solution were oxidized to aldicarb sulphone and the total sulphone concentration was determined by GC-FPD after extraction with dichloromethane and clean-up with an activated charcoal column. The detection limit was 0.0024 mg/l. The mean recoveries from spiked urine in the range 0.04-0.12 mg/l were 90.9%, 86.6%, 92.6% for aldicarb, aldicarb sulphoxide and aldicarb sulphone, respectively.

Modulation of extracellular matrix gene expression by heparin and endothelial cell growth factor in human smooth muscle cells

We have previously shown that human vascular smooth muscle cells grown for several passages in the presence of heparin and endothelial cell growth factor (ECGF) exhibit profound alterations in the synthesis of extracellular matrix proteins. In the present study, we demonstrate that the mRNA steady-state levels for various matrix macromolecules were altered in the presence of heparin and ECGF, but not ECGF alone. Specifically, the expression of types I and IV collagens, fibronectin, and decorin proteoglycan genes were markedly inhibited, whereas that of versican proteoglycan and beta-actin genes were unaffected. The effects were fully reversible. The suppression of the collagen gene expression was related to decreased collagen production by cells incubated with heparin and ECGF. Thus, heparin and ECGF synergistically elicit a coordinate and selective inhibition of matrix gene expression in human smooth muscle cells.

Ultrafast all-optical deflection based on an induced area modulation in nonlinear materials

A novel all-optical area-modulation scheme is suggested and experimentally demonstrated. In a mutually perpendicular interaction geometry inside a nonlinear material, the signal beam, which passes through an induced temporal prism formed by an area-modulated optical pump beam, undergoes a spatial phase modulation that leads to a beam deflection. Advantages and potential applications of the new all-optical modulation are addressed.

The influence of limb alignment on the gait of above-knee amputees

Biomechanical gait tests on above-knee amputees were conducted in which the alignment of the prosthesis was changed systematically. An eight-segment biomechanical model of the above-knee amputee was developed to analyse and present the three-dimensional kinematic and kinetic data obtained. The effects of alignment changes on the above-knee amputees' gait were studied in terms of the angular displacements of the lower limbs, ground reactions and intersegmental moments. It was found that following the alignment changes the angular displacement at the hip joint on the prosthetic side showed compensatory actions by the amputee. The ground reaction force was sensitive to alignment changes, and in particular, the changes in the characteristics of the fore-aft component of the ground force could be related to the alignment changes. The antero-posterior intersegmental moments at the prosthetic ankle and knee joints were evidently influenced by alignment.

Acetylcholine, Ca2+ overload and oscillatory potentials in isolated ventricular myocytes

The events caused by overdrive-induced calcium overload were studied in guinea pig isolated ventricular myocytes. Overdrive may induce oscillatory potentials (Vos) and a prolonged depolarization (Vex), as well as the underlying currents (Ios and Iex, respectively). Acetylcholine (ACh) reduced or abolished these events, an action which was blocked by atropine. Norepinephrine exaggerated the effects of overdrive, and ACh markedly antagonized such an enhancement. Caffeine at low concentrations increased both Ios and Iex whereas at high concentrations caffeine abolished Ios but increased Iex. Quinacrine abolished both events. Voltage clamp depolarizing steps abolished Ios (and did not reverse it). Thus, the effects of Ca overload are antagonized by ACh in the absence and presence of sympathetic enhancement. Also, the mechanism underlying Ios appears to involve an electrogenic Ca extrusion and not an increase in a nonspecific conductance.

Replication of bovine papillomavirus type 1 DNA initiates within an E2-responsive enhancer element

When bovine papillomavirus transforms cells in vitro, it maintains its genome as a multicopy nuclear plasmid. Plasmid DNA extracted from such transformed cells was analyzed by the two-dimensional gel electrophoresis technique of Brewer and Fangman (B. Brewer and W. Fangman, Cell 51:463-471, 1987). The replication intermediates detected in these assays were found to be the sums of the oligomeric and monomeric forms of the replicating plasmids. The multimeric DNAs were shown by field inversion gel electrophoresis and partial restriction digestion to be head-to-tail concatemers of the monomeric forms. Furthermore, the multimers progressed in size by steps of one monomer, indicating that they did not arise by replication segregation mistakes of the unit length, which would predict a ladder spaced by integrals of two monomers. To map the plasmid DNA replication origin, the replication intermediates of the monomers were isolated by successive sucrose gradient centrifugation and then examined by the two-dimensional gel electrophoresis method. The patterns detected show that bovine papillomavirus type 1 replicates in these cells bidirectionally and that one replication origin site in the viral genome is utilized. By employing several restriction enzymes and specific viral DNA probes to dissect the replication intermediates, we were able to map the origin of initiation site with some precision. The initiation site, which maps to bovine papillomavirus type 1 DNA position 7730 +/- 100 bp, places the origin within that region of the viral upstream regulatory region which contains the major cluster of transcription factor E2-binding sites, E2RE1. Thus, the actual viral plasmid origin of replication maps near, but outside, genetic elements previously shown to be important for plasmid maintenance.

[Isolation and identification of oral spirochaetes and Fusobacterium in juvenile periodontitis]

Periodontal pocket specimens of 40 juveniles periodontitis (JP) and specimens from gingival sulcus in 40 normal juveniles (NP) were examined. 25 strains of anaerobic oral spirochaete (62.5%) (17 strains were Treponema microdentium, 3 strains macrodentium, 2 strains T orale, 3 strains Borrelia) and 21 strains of fusobacterium were isolated in 40 JP. In 40 NP, 2 strains of spirochaetes (5%) and 3 strains fusobacterium (7.5%) were found. This study shows that there is a relationship between the infection of spirochaeta, fusobacterium and JP.

[Dissolution of metronidazole stilus]

Metronidazole stilus is a new preparation to be inserted into periodontal pockets for treatment of periodontitis. The certificate and file number of approval given to this new product were issued by the Ministry of Public Health in August, 1989. Its shape looks like a toothpick and the width, thickness and length are 1.5mm, 0.7mm and 3 cm, respectively. The content of metronidazole in each cm of the stilus is 2.2 mg. We have studied the dissolution of the new preparation by rotation basket method. The kinetic process of dissolution approximates first order kinetics. The K, t0.5 and t0.9 are 0.0624 min-1, 12.8 and 38.6 minutes, respectively. The requirement is that the dissolved percentage should not be lower than 60% of the added amount in 30 minutes. In order to have a dissolution test similar to that of the stilus in dental pockets, we examined the dissolution in static condition. The results showed that a very high dissolution rate appeared in the beginning, but it decreased quickly, and 71.76% of metronidazole was not dissolved until 48 hours. So one insertion per two days for clinical use is suggested.

Prebiotic synthesis of histidine

The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

[Specific monoclonal antibodies to F41 adhesin of enterotoxigenic Escherichia coli and their potential uses as diagnostic and therapeutic reagents]

A set of hybridoma cell lines, namely, L10, B10, C32, B1, E7, E40 and B49, secreting monoclonal antibodies (MABs) specific to F41 adhesin antigens of ETEC was obtained by somatic hybridization. These MABs manifested strongly specific binding reactivities in DA, ELISA and IFA to all tested F41+ ETEC strains. All these MABs recognized the same or closely related epitopes on the adhesin, as indicated in antigen-competition ELISA with HRP-labeled MABs. The distribution patterns of these epitopes which appeared repeatedly on each pilus were visualized by MAB-immunogold technique and immunoelectron microscopy. The adhesion of ETEC bearing F41 adhesin to the epithelial cells of small intestine from new borne calves and piglets was inhibited in vitro by F41-specific MABs. A dot-immunobinding assay based on F41-specific MABs was developed for determining F41 antigens in fecal samples with HRP-labeled MABs. The assay was highly sensitive and specific, and could be used in rapid detection and screening of F41 adhesin antigens in field samples.

Pharmacokinetics and autoradiography of [3H] or [14C]stepholidine

After iv [3H]stepholidine (SPD) 12 MBq/kg, the concentration-time curve in rats was found to be a two-compartment open model. The distribution phase T1/2 alpha = 3.6 min, the elimination phase T1/2 beta = 168 min. The absorbed radioactivities of [3H] SPD in 15-30 min were 80-87%. The amounts of [3H]SPD bound to plasma protein, liver and kidney homogenates were estimated to be 37, 31, and 30%, respectively. During 3 d after ip [3H]SPD 50 MBq/kg, 56% of the radioactivity was excreted in urine and 5% in feces, thus, it suggested that [3H]SPD was mainly excreted by kidneys. After iv a single dose of [14C]SPD in mice, the whole-body autoradiography showed that [14C]SPD was rapidly distributed among various tissues. High radioactivities were found in kidneys, liver, brain, salivary glands, Harder's glands, heart blood and muscle at 2 min and intensively localized in kidneys and stomach mucosa at 30 min. The radioactivities in these tissues disappeared 4 and 8 h later, while that in intestine could not be detected 24 h later.

Effect of a cell differentiation inducer, ganglioside GM3, on the neutral glycosphingolipid composition and cell membrane fluidity of a human promyelocytic leukemia cell line HL-60

In this paper the authors confirmed the finding reported by Nojiri et al that exogenous ganglioside GM3 could induce HL-60 cells to differentiate along the monocytic-macrophage route with significant inhibition of proliferation. It was found that after differentiation the neutral GSL content of CDH and CMH increased, while that of CXH, a polyhexosyl ceramide with a TLC mobility slower than CQH, decreased significantly. The membrane fluidity of HL-60 cells decreased after GM3 treatment.

Molecular Characterization of the Brittle-2 Gene Effect on Maize Endosperm ADPglucose Pyrophosphorylase Subunits

Activity of the enzyme ADPglucose pyrophosphorylase is known to be reduced in maize (Zea mays L.) endosperm mutants at two independent loci, Shrunken-2 (Sh(2)) and Brittle-2 (Bt(2)). Spinach leaf ADPglucose pyrophosphorylase has previously been shown to comprise two subunits of 51 and 54 kilodaltons. Anti-bodies raised to each of the two subunits of spinach leaf ADPglucose pyrophosphorylase were found to cross-react to different bands on Western blots prepared from polyacrylamide gel electrophoresis separated wild-type maize endosperm proteins. The anti-spinach leaf 51 kilodalton subunit antibody cross-reacted with a 55 kilodalton maize endosperm protein and the anti-spinach leaf 54 kilodalton subunit antibody cross-reacted with a 60 kilodalton maize endosperm protein. These immunological reactions were observed in maize endosperm extracts and with a highly purified preparation of maize endosperm ADPglucose pyrophosphorylase. Mutant bt(2) endosperm lacked the 55 kilodalton subunit while mutant sh(2) endosperm lacked the 60 kilodalton subunit on Western blots. These results suggest that the maize endosperm ADPglucose pyrophosphorylase is made up of two immunologically dissimilar subunits and that the bt(2) and sh(2) mutations cause reduction in ADPglucose pyrophosphorylase activity through the lack of one of these two subunits. An ADPglucose pyrophosphorylase cDNA clone antigenically selected from a rice seed cDNA expression library was found to hybridize strongly with a cDNA corresponding to a maize endosperm transcript which is absent in a W64A bt(2) mutant. Thus, the bt(2) mutant causes the absence not only of the small subunit but of the corresponding transcript. Bt(2) is implicated as the structural gene for the small (54 kilodalton) subunit of maize endosperm ADPglucose pyrophosphorylase.

[Relation of the changes in hemorheologic indices and the site and size of cerebral infarction]

According to the CT findings, 83 cases of cerebral infarction were divided into two groups. One group consisted of cases with occlusion of the cerebral arterial main trunks and the other of those with occlusion of the penetrating arteries. The HCT and the whole blood viscosity were higher in the former group, whereas the rate of platelet aggregation was higher in the latter group. These results suggested that the physiopathology involved in the formation of the large cerebral infarction in the cerebral cortex and subcortex was different from that of the small infarction in the deep cerebral structures. Besides, it was found that the blood viscosity has positive relationship with the size of the cerebral infarction in the former group. It was presumed that the HCT and the blood viscosity should be reduced immediately for treating the larger cerebral infarction, but to lower the rate of platelet aggregation for treating the small infarction in the deep cerebral structures would be of benefit.

Effects of strophanthidin on the slow inward current in guinea-pig isolated ventricular myocytes

1. The effect of strophanthidin on the slow inward current (Isi) and on contractile force were studied in guinea-pig isolated ventricular myocytes and intact papillary muscles, respectively. In myocytes, both low (10 nmol/L) and high (1-10 mumols/L) concentrations had small or no effects in either direction on Isi whereas norepinephrine (10-100 nmol/L) increased it. To determine whether the same results are obtained after decreasing or increasing intracellular calcium or sodium, the same concentrations of strophanthidin were tested in different procedures that are known to (i) increase [Ca]i and decrease [Na]i (high [Ca]o, 3.6-5.4 mmol/L; low [Na]o, 112 mmol/L; (ii) decrease [Ca]i and increase [Na]i (low [Ca]o, 0.45-1 mmol/L; Sr, 1 mmol/L; (iii) decrease [Ca]i and [Na]i (Cd, 0.1-0.2 mmol/L); and (iv) increase [Ca]i and [Na]i (veratridine, 0.2 mumol/L). High [Ca]o and veratridine increased whereas low [Ca]o and Cd decreased Isi. In contrast, during these various procedures, strophanthidin had small and inconsistent effects at a low or high concentration. In intact papillary muscles, low strophanthidin decreased whereas high strophanthidin increased contractile force. It is concluded that strophanthidin has little direct or indirect effect on Isi and that the decrease in force by low and increase in force by high concentrations in intact muscle are probably related to demonstrated decrease and increase, respectively, in intracellular sodium activity.

[The effect of intrapartum and neonatal asphyxia on the cognitive and behavioral development of children]

The present study includes 4 groups of subjects: 30 children with a history of intrapartum asphyxia, 30 children with a history of mild neonatal asphyxia, 15 children with a history of severe but transitory neonatal asphyxia, and 30 children who had normal deliveries. Psychological and neuropsychological assessments were done at 6 years of age. There are no significant difference among 4 groups in IQ, social maturity age, most neuropsychological functions and incidence of attention deficit disorder with hyperactivity. 4 test scores in Halstead-Reitan Battery infer to visual-motor functioning showed backwardness in asphyxiated groups. Behavior problems are more frequently seen in the asphyxiated groups than in the control group.