Treatment of 119 cases of verruca vulgaris and verruca plana by external application of pulvis pepper alba.
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Administration, Topical↗
Biomedical subjects
L Zhao
Publications and source records attributed to L Zhao.
[Studies on some characteristics of a strain of mink infectious enteritis virus].
A strain of mink infectious enteritis virus that was isolated from the east district of China can be bred on FK cell. Concentrated viruses were purified by using Sepharose-4B chromatography. The size of the virus was about 20-22 nm by electron microscope. Viral nucleic acid was extracted from pure virus by using SDS-protease K-Phenol. Tests with diphenylamine, acridine orange and the curve of thermal dentuation, etc. showed that the virus had a single-stranded DNA. The molecular weight of the ssDNA was from 1.5 x 10(6) to 2.0 x 10(6) determined by length of the virul nucleic acid.
DNA, Single-Stranded↗
[An experimental animal model study of HCMV].
This Paper is a study of animal model on the Kunmin and BALB/C mice infected HCMV-AD169. The death-rate showed a marked higher BALB/C mice (28.75%) than the kunmin mice. The Kunmin mice Percentage of diseased (94.74%) higher than BALB/C mice. Brian tissue of two groups mice that pathological changed was equal by HCMV infected.
Animals↗
[Pharmacognostical study on the Chinese drug biejia].
The Chinese drug Biejia is taken from a variety of animals. In this paper, 3 kinds of Biejia from different genera have been studied in their pharmacognostical characteristics and microproperties. A key has been complied based on the experimental results.
Animals↗
Structure of the gene for the catalytic subunit of human DNA polymerase delta (POLD1).
We have isolated genomic DNA clones covering the gene for human DNA polymerase delta catalytic subunit (POLD1) and its 5' flanking sequence. This gene is divided into 27 exons and is distributed over at least 32 kb of DNA. The exons and most of the introns are relatively small. The sizes of the exons range from 55 to 201 bp. Seven introns are smaller than 100 bp. Intron 1 is the largest intron, with a size of greater than 10 kb. All of the intron-exon junctions match well with the reported consensus sequences. Multiple copies of the Alu repetitive sequence and the variable number of tandem repeats were found in several introns. Transcription of POLD1 appears to initiate at multiple sites. The major start site was 53 nucleotides upstream of the ATG start codon. The sequence of the promoter and upstream DNA is G+C rich and does not contain a TATA sequence. Several potential transcription factor-binding sites, including the AP2-, CTF-, Ets1-, GCF-, MBF-1-, NF-E1-, and Sp1-binding sites, were found in this region. A 1.8-kb pol delta promoter DNA directed the expression of a luciferase reporter gene when transfected into HeLa cells.
Base Sequence↗
Progression of precancerous gastric lesions.
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Biopsy↗
Detection of residual leukemic cells in patients with acute promyelocytic leukemia by the fluorescence in situ hybridization method: potential for predicting relapse.
The translocation between chromosomes 15 and 17, t(15;17)(q22-24;q11-21), is present in the bone marrow cells of most patients with acute promyelocytic leukemia (APL). Although conventional cytogenetic methods are useful for diagnosing this disease, difficulties are experienced in detecting residual disease among those patients who have achieved remission. In this study, we used the fluorescence in situ hybridization (FISH) method to attempt to detect residual leukemic cells in 10 APL patients in clinical remission. The duration of remission ranged from 2 to 93 months at the time of study. Multiple bone marrow samples were analyzed by FISH in most patients. In 6 patients, no cell with t(15;17) was found. These patients remain in complete remission at present (approximately 25 to 33 months since first studied by FISH). In 4 patients, low frequencies of cells with t(15;17) were observed in at least one bone marrow sample examined. All of these patients relapsed within 1 to 14 months. No cell with t(15;17) was identified by the conventional G-banding method in any sample. The FISH results correlated well with that of a two-round nested reverse transcription polymerase chain reaction assay that was performed on the same samples. Thus, our study suggests that FISH is potentially a useful tool for detecting residual APL cells and for identifying patients at high risk of relapse.
Base Sequence↗
Separation of pure populations of epithelial cells from rabbit distal colon.
A simple method using divalent chelators is described for the isolation of viable populations of surface and crypt cells from rabbit distal colon. Histological studies were performed to monitor colonocyte dissociation and determine contamination by nonepithelial cells. Cell viability was assessed by trypan blue exclusion assay and by 22Na uptake measurements. Electron microscopy was used to determine the integrity of the isolated cells. Alkaline phosphatase and [3H]thymidine uptake were measured to assess the purity of the different cell fractions. Combined fractions 4 and 5 contained the highest percentage of pure surface cells, while fractions 10, 11, and 12 were predominantly crypts. Alkaline phosphatase activity was 13 +/- 3-fold higher in the surface cells than in the crypt cells, while [3H]thymidine uptake was 8 +/- 4-fold higher in the crypt cells than in the surface cells. Amiloride-sensitive and -insensitive 22Na uptake was the same in the surface cells directly after isolation and after 3 h in culture. In this study we demonstrate a method for the preparation of highly enriched fractions of rabbit colon surface and crypt cells that remain viable and functional in short-term culture.
Animals↗
Immunolocalization of interleukin-1 alpha in rat mandibular molars and its enhancement after in vivo injection of epidermal growth factor.
Immunolocalization of interleukin-1 alpha in the first mandibular molars of rats from day 0-12 postnatally showed that the protein was localized in the epithelial stellate reticulum adjacent to the dental follicle. Staining of the stellate reticulum was most prominent in the early days postnatally and was absent by postnatal day 11. Injection of epidermal growth factor into rats at day 0 greatly increased the intensity of the staining for interleukin-1 alpha in the stellate reticulum. Epidermal growth factor (EGF) enhanced the gene expression of interleukin-1 alpha in stellate reticulum cells in vitro, and this study suggests there is enhanced translation of interleukin-1 alpha messenger RNA in the stellate reticulum following EGF injection. In turn, the interleukin-1 alpha may exert its effect on the dental follicle cells adjacent to the stellate reticulum because EGF also enhanced expression of the interleukin-1 receptor type I messenger RNA in cultured dental follicle cells as well as enhancing its expression in vivo. In view of the fact that injection of EGF will stimulate precocious eruption of teeth, its stimulus of interleukin-1 alpha synthesis in the stellate reticulum may be the mechanism by which EGF initiates a cascade of molecular events to signal the onset of tooth eruption.
Animals↗
Effects of purified Clostridium difficile toxin A on rabbit distal colon.
BACKGROUND & AIMS: Antibiotic-associated pseudomembranous colitis in humans is caused by proliferation of Clostridium difficile, which elaborates an enterotoxin toxin A that causes epithelial damage and altered motility in rabbit small intestine. The aim of this study was to assess the effects of toxin A on rabbit distal colonic motility and to relate this to histological damage and inflammatory mediator production. METHODS: Two hundred micrograms per milliliter of toxin A was placed in a distal colonic loop in anesthetized rabbits, and myoelectric activity was recorded for the following 7 hours. The colon was histologically evaluated and assayed for eicosanoid production. The effects of toxin A on longitudinal and circular muscle were also assessed in vitro. RESULTS: Beginning 1 hour after instillation, toxin A caused a significant increase in the number of spike bursts without altering slow wave frequency; this was associated with an increase in mucosal neutrophils and increased production of prostaglandin E2 and leukotrienes B4 and C4/D4/E4. Seven hours after administration of toxin A, mediator levels and myoelectric activity remained increased but significant mucosal damage was now also present. Toxin A did not affect longitudinal or circular muscle in vitro. CONCLUSIONS: C. difficile toxin A caused a significant neutrophil infiltration and an increased myoelectric activity before producing mucosal damage. The myoelectric effect may be indirect, resulting from the production of motility-altering arachidonic acid metabolites.
Animals↗
Effect of zinc on strength and fatigue resistance of amalgam.
OBJECTIVES: This study was conducted to determine the effect of zinc in amalgam on the static mechanical properties and resistance to fatigue-crack propagation of amalgams. METHODS: Fatigue, creep, compressive and flexure tests were performed on high-Cu Dispersalloy (Johnson and Johnson Dental Products Co., East Windsor, NJ, USA) and low-Cu Velvalloy (S.S. White Dental Products Int., Philadelphia, PA, USA) in both Zn-containing and Zn-free formulations. Linear Elastic Fracture Mechanics principles were used to characterize the fatigue behavior (crack lengths were monitored). RESULTS: The incorporation of Zn into these amalgams significantly improved their fatigue and creep resistance, while the effect of Zn on the static compressive and flexure strengths was not consistent. Zn significantly increased (p < 0.05) the resistance to fatigue crack propagation during Stage II crack growth for both amalgams, and increased the variations in crack velocity for a given stress intensity difference, without visibly altering the path or nature of the fatigue cracks. Possible influences on fatigue behavior were the mixed microstructure (particles and matrix), the nature of the crack tip, and creep. SIGNIFICANCE: The superior resistance to tensile fatigue crack propagation of amalgams containing small amounts of Zn (approximately 1 wt%) in vitro compared with amalgams with no Zn correlated with the superior resistance to marginal breakdown in vivo of Zn-containing amalgams. The range of stress intensities over which stable cracks could propagate was small, while the large variations observed in fatigue crack growth rates for individual materials invalidate predicting a unique fatigue life from the empirical equations obtained.
Analysis of Variance↗
The myosin catalytic domain does not rotate during the working power stroke.
Electron paramagnetic resonance spectroscopy of a spin probe attached to cys-707 on myosin cross-bridges was used to monitor the orientation of the myosin catalytic domain at the beginning and end of the working power stroke in active muscle. Elevated concentrations of orthophosphate and decreased pH were used to shift the population of cross-bridges from force-producing states into low force, pre-power-stroke states. The spectrum of probes in active fibers was not changed by conditions that reduced tension by 70%, indicating that the orientation of the catalytic domain was the same at the beginning and end of the power stroke. Thus the data show that the catalytic domain remains rigidly oriented on the actin filament during the power stroke.
Animals↗
Muscle cross-bridges bound to actin are disordered in the presence of 2,3-butanedione monoxime.
Electron paramagnetic resonance spectroscopy was used to monitor the orientation of muscle cross-bridges attached to actin in a low force and high stiffness state that may occur before force generation in the actomyosin cycle of interactions. 2,3-butanedione monoxime (BDM) has been shown to act as an uncompetitive inhibitor of the myosin ATPase that stabilizes a myosin.ADP.P(i) complex. Such a complex is thought to attach to actin at the beginning of the powerstroke. Addition of 25 mM BDM decreases tension by 90%, although stiffness remains high, 40-50% of control, showing that cross-bridges are attached to actin but generate little or no force. Active cross-bridge orientation was monitored via electron paramagnetic resonance spectroscopy of a maleimide spin probe rigidly attached to cys-707 (SH-1) on the myosin head. A new labeling procedure was used that showed improved specificity of labeling. In 25 mM BDM, the probes have an almost isotropic angular distribution, indicating that cross-bridges are highly disordered. We conclude that in the pre-powerstroke state stabilized by BDM, cross-bridges are attached to actin, generating little force, with a large portion of the catalytic domain of the myosin heads disordered.
Actins↗
Cross-reactivity of Rickettsia japonica and Rickettsia typhi demonstrated by immunofluorescence and Western immunoblotting.
Cross-reactivity between Rickettsia japonica and R. typhi was observed by immunofluorescence tests using sera from patients with Oriental spotted fever (OSF), from whom the causative agent was isolated and identified as R. japonica. Western immunoblotting with these sera revealed that only the 120-kilodalton surface polypeptide, i.e., rickettsial outer membrane protein (rOmp) B, has a common antigenicity with the 105-kilodalton surface polypeptide of R. typhi. In some cases, antibodies specifically reactive with R. typhi were detected in acute-phase sera followed by a significant rise in titers, possibly because of an anamnestic response to a previous infection with an R. typhi-like agent; the sera retained reactivity to R. typhi even after absorption by a homologous strain. A lipopolysaccharide (LPS)-like antigen of R. typhi was found to be reactive with some sera of OSF patients. The ladder bands on Western immunoblot of rickettsial organisms were confirmed to be polysaccharide in nature, which was demonstrated by comparing them with the pattern of silver-stained gel of proteinase K-treated rickettsial specimens after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Antibodies, Bacterial↗
Uptake of chloroform by skin during short exposures to contaminated water.
Uptake of chloroform into hairless rat stratum corneum from dilute aqueous solutions was studied using tape-stripping to determine amounts deposited in the skin under various environmental exposure scenarios. The length of exposure of sedated animals to the chloroform-containing medium, the frequency and duration of tape-stripping, and the number of tape-strips per location were varied to map the stratum corneum substantivity of chloroform. Eight minutes immersion of the rat within a well-stirred solution at 36 degrees C was found to be adequate time for the gradient to be established fully across the stratum corneum. Penetration was progressively deeper as the exposure time increased. Substantial evaporative loss of chloroform from the aqueous medium of application seem to be responsible for lower cumulative amounts taken up when the same solution was held on the rat's skin within a stainless steel template of fixed area. Of the total uptake (29 mg) from a dilute stirred solution of chloroform (0.44 mg/ml) at 36 degrees C, about 95% was systematically absorbed after a 30 min exposure as determined by residuals (measurement of bath concentrations).
Animals↗
The cardiovirulent phenotype of coxsackievirus B3 is determined at a single site in the genomic 5' nontranslated region.
We report the construction of chimeric coxsackievirus B3 (CVB3) strains in which sequences of an infectious cDNA copy of a noncardiovirulent CVB3 genome were replaced by the homologous sequences from a cardiovirulent CVB3 genome to identify which of 10 predicted genetic sites determine cardiovirulence. Cardiovirulent phenotype expression was consistently linked to nucleotide 234 (U in cardiovirulent CVB3 and C in avirulent CVB3) in the 5' nontranslated region. Reconstructions of the parental noncardiovirulent CVB3 genome from chimeras restored the noncardiovirulent phenotype when tested in mice. Inoculation of severe combined immunodeficient (scid) mice with the noncardiovirulent CVB3 strain resulted in massive cardiomyocyte necrosis in all animals. Sequence analysis of viral genomes isolated from twelve scid mouse hearts showed that only nucleotide position 234 was different (a C-->U transition) from that in the input parental noncardiovirulent CVB3 genome. Higher-order RNA structures predicted by two different algorithms did not demonstrate an obvious local effect caused by the C-->U change at nucleotide 234. Initial studies of parental and chimeric CVB3 replication in primary cultures of fetal murine heart fibroblasts and in adult murine cardiac myocytes demonstrated that viral RNA transcriptional efficiency is approximately 10-fold lower for noncardiovirulent CVB3 than for cardiovirulent CVB3. CVB3 did not shut off protein synthesis in murine cardiac fibroblasts, nor were levels of viral protein synthesis significantly different as a function of viral phenotype. Taken together, these data support a significant role for determination of the CVB3 cardiovirulence phenotype by nucleotide 234 in the 5' nontranslated region, possibly via a transcriptional mechanism.
Animals↗
Characterization of PGE2 receptors in isolated rabbit colonic crypt cells.
The physiological effects of prostaglandins (PG) are mediated through their interactions with specific receptors on effector cells. In this study the properties of PGE2 receptors in the rabbit distal colon were examined. We report the presence of specific, saturable, and high-affinity binding sites of PGE2 of the EP2 subtype in isolated colonic crypts. Scatchard analysis revealed the presence of two binding sites with dissociation constants of 0.3 and 10.8 nM and corresponding maximum number of receptors of 15 and 134 fmol/10(6) cells. From competition experiments in the presence of guanosine 5'-O-(3-thiotriphosphate), PGE2 binding was decreased, suggesting that the receptor is coupled to a G protein. No PGE2 binding sites were detected in surface cells. Levels of adenosine 3',5'-cyclic monophosphate (cAMP) were measured in isolated epithelial cells after being exposed to different concentrations of PGE2. cAMP levels were significantly increased only in the crypt cells when exposed to PGE2. These data provide the first demonstration for the existence of PGE2 receptors on colonic crypt cells, which when activated lead to increased levels of cAMP.
Animals↗
Transcription and translation of CSF-1 in the dental follicle.
The dental follicle, a loose connective tissue sac which surrounds the unerupted tooth, is required for eruption to occur. Injection of colony-stimulating factor-1 (CSF-1) will accelerate molar eruption in rats, as well as stimulate tooth eruption in osteopetrotic rats. Utilizing in situ hybridization and reverse- transcription polymerase chain-reaction techniques, we show here that CSF-1 mRNA is present in vivo in the dental follicle of the first mandibular molar of the rat. Analysis of the molars from day 0 through day 10 post-natally demonstrates that the maximal expression of CSF-1 mRNA is at day 3 post-natally. Immunostaining also reveals that the CSF-1 mRNA is translated, with immunostaining for the CSF-1 itself, being heavy in early post-natal days and absent by day 9 postnatally. In view of the fact that there is a maximal influx of mononuclear cells (monocytes) into the dental follicle at day 3 post-natally--an influx which increases the numbers of osteoclasts needed to form a tooth eruption pathway--it is probable that the maximal expression of CSF-1 mRNA by day 3 post-natally contributes to this monocyte influx. Thus, this study establishes a relationship among a molecule (CSF-1), cell (monocyte), and tissue (dental follicle) that appear to play a major role in tooth eruption.
Animals↗