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Biomedical subjects

S Huang

Publications and source records attributed to S Huang.

At least 703 records · Page 39Linked to original sources
PubMed1971

Hepatitis-associated antigen hepatitis. An electron microscopic study of virus-like particles in liver cells.

Light and electron microscopic examinations were carried out on liver tissues from 6 renal transplant recipients who developed Australia antigen-associated hepatitis, referred to in this paper as hepatitis-associated antigen (HAA) hepatitis. While under immunosuppressive therapy, the patients showed rapid progression of acute hepatitis to chronic active hepatitis and posthepatitic cirrhosis resulting in liver failure. By electron microscopy, in 5 of 6 patients, characteristic virus-like particles of 230 A size were observed in massive numbers in the nucleus and occasionally in the cytoplasm of liver cells. No similar particles were found in liver biopsies from other patients. These particles had an appearance of nucleocapsid without an outer coat, and were believed to be the viruses in their natural infective states. The predominantly intranuclear location of the particles and the associated nuclear changes suggested that the nucleus is the primary site of virus replication. The finding of the virus-like particles is believed to be diagnostic for HAA hepatitis. While HAA is implicated in serum hepatitis, the identification of HAA with the virus-like particles of this study is still to be established. In the phagosomes, there were some particles showing an outer membrane and a tail-like structure. Both the coated and the noncoated particles were believed to be the same virus. The phagosomes also contained what appeared to be "degradated" viral material. The lysosomal activity in the infected hepatitic cells seemed to be increased. This study showed nonspecific changes of the liver cell nuclei and organelles, probably related to viral infection. The precise mechanism of cell injury remains to be elucidated. However, the result of this study has provided a reasonable basis for future investigations of HAA hepatitis.

Biopsy↗
PubMedDate not supplied

High levels of carcinogenic polycyclic aromatic hydrocarbons (PAH) in 20 brands of Chinese cigarettes.

Tar and nicotine levels have been made to conform to EU standards as of 1 July 2004, but data on tobacco-derived carcinogenic compounds, such as PAH, in Chinese cigarettes are lacking in the literature. Levels of tar, nicotine, carbon monoxide and PAH were measured in 20 cigarette brands purchased in China between 2003 and 2004. Higher nicotine and tar levels were found in Chinese cigarettes than in European brands just 3 months before the above deadline; carcinogenic PAH levels were about 1.5 fold higher than in European cigarettes, but analysed singly, the mean value of benzo(a)pyrene (B(a)P) and dibenzo(a,h)anthracene (DBA), the most potent carcinogenic PAH yields, were 2.4 and 4.4 fold higher, respectively. Tar levels were well correlated with carcinogenic PAH (r = 0.53, P < 0.01), thus providing an easily measurable parameter for ranking various cigarette brands in developing countries where more sophisticated techniques might not be feasible for lack of funds and expertise.

Carcinogens↗
PubMedDate not supplied

Fluoride profiles in dental calculus from Japanese, Chinese and British residents.

Whether the fluoride concentrations and profiles differ in human dental calculus obtained from different countries was investigated. A total of 203 dental calculus deposits on 203 permanent teeth from residents (mean age, 52.1 years) of Nagoya (Japan), Shanghai (China), Leeds (Great Britain) and the Wuhan mountainous area (China, fluoridated area) were analysed. An abrasive microsampling procedure was used to examine fluoride distribution. There were five types of fluoride profiles in dental calculus in each area/country (designated types L, J, U, T, W). In supragingival calculus, type L (highest in the outermost layers) and type J (highest in the innermost layers) both had significantly higher values than type U (high in the surface and innermost layers) but were relatively identical. In subgingival calculus, type W (high in the outermost, mid and innermost layers) was characteristics. Calculus from the Wuhan mountainous area (fluoridated) had the highest fluoride concentration, followed by Leeds (non-fluoridated), and Nagoya and Shanghai (non-fluoridated) calculus had the lowest. Fluoride concentrations in supragingival calculus were higher in teeth extracted because of periodontal diseases than dental caries. It is concluded that fluoride concentrations and distribution in dental calculus differ from country to country, probably due to different fluoride environments.

Adult↗
PubMedDate not supplied

Dual expression of GABA or serotonin and dopamine in Xenopus amacrine cells is transient and may be regulated by laminar cues.

Both local cell-cell interactions and lineage bias have roles in determining the different retina cell phenotypes. In this study, subpopulations of amacrine cells that dually express GABA or serotonin (5-HT) and dopamine (DA) are identified in the early Xenopus tadpole (stages 42-48) retina. GABA is first detected by immunocytochemistry in amacrine cells at stage 35/36, 5-HT at stage 39, and DA at stage 41. As the number of these subtypes of amacrine cells increases by differentiation, a subset of them transiently express two neurotransmitters. GABA/DA double-labeled amacrine cells are detected first at stage 42, at which time they constitute 52% of the DA-containing population; this percentage decreases to only 3% by stage 48. 5-HT/DA amacrine cells are detected only at stage 44, constituting about 20% of the DA-containing cells and 4% of the small-dim 5-HT-containing cells. Regional location does not differentially affect the differentiation of these three types of amacrine cells (DA only, GABA/DA, and 5-HT/DA cells); each type is found more in the anterior and dorsal than the posterior and ventral quadrants, and their overall distribution patterns are statistically indistinguishable. However, these subtypes of amacrine cells reside in different sublamina of the inner nuclear layer. DA-only amacrine cells are located predominantly in the inner sublayer of the 2-3 cell thick amacrine cell layer, closest to the inner plexiform and the ganglion cell layers. Both types of double-labeled cells are located mostly in the outer sublayer of the amacrine cell layer, closest to other interneurons in the inner nuclear layer. This distinct sublaminar location of different neurotransmitter phenotypes suggests that local laminar cues influence the coexpression of neurotransmitters in amacrine cells.

Animals↗
PubMedDate not supplied

Micropatterned surfaces for control of cell shape, position, and function.

The control of cell position and function is a fundamental focus in the development of applications ranging from cellular biosensors to tissue engineering. Using microcontact printing of self-assembled monolayers (SAMs) of alkanethiolates on gold, we manufactured substrates that contained micrometer-scale islands of extracellular matrix (ECM) separated by nonadhesive regions such that the pattern of islands determined the distribution and position of bovine and human endothelial cells. In addition, the size and geometry of the islands were shown to control cell shape. Traditional approaches to modulate cell shape, either by attaching suspended cells to microbeads of different sizes or by plating cells on substrates coated with different densities of ECM, suggested that cell shape may play an important role in control of apoptosis as well as growth. Data are presented which show how micropatterned substrates were used to definitively test this hypothesis. Progressively restricting bovine and human endothelial cell extension by culturing cells on smaller and smaller micropatterned adhesive islands regulated a transition from growth to apoptosis on a single continuum of cell spreading, thus confirming the central role of cell shape in cell function. The micropatterning technology is therefore essential not only for construction of biosurface devices but also for the investigation of the fundamental biology of cell-ECM interactions.

Animals↗
PubMedDate not supplied

A case report of frosted branch angiitis and its visual electrophysiology.

We reported a 5-years old boy with frosted branch angiitis in both eyes. The visual acuities of the two eyes were suddenly lost to 5/50. The fluorescein angiography, electroretinograms (ERGs) and pattern evoked potentials (PVEPs) had been tested at the acute and the recovery stage of the disease. At the onset of the disease, fluorescein angiography showed obvious dye leakage from dilated retinal veins. The PVEPs and whole field ERGs including rod, maximum, OPs and cone responses were seriously decreased and prolonged, indicating that the visual pathway's and retinal functions were greatly damaged. The patient had an excellent response to systemic prednisone. One month after the treatment, the visual acuities recovered to 60/50 in both eyes. The fluorescein angiography showed that leakage from blood vessels was diminished, but the lesions at macula and optic disc were persisted a longer time even to the end of treatment. Through 6 months medication, nearly all of the electrophysiological abnormalities had been resolved.

Administration, Oral↗
PubMedDate not supplied

Formation of haematopoietic microenvironment and haematopoietic stem cells from single human bone marrow stem cells.

Haematopoietic stem cells are a population of cells capable both of self renewal and of differentiation into a variety of haematopoietic lineages. Enrichment techniques of human haematopoietic stem cells have used the expression of CD34, present on bone marrow progenitor cells. But most CD34+ bone marrow cells are committed to their lineage, and more recent efforts have focused on the precise characterization of the pluripotent subset of CD34+ cells. Here we report the characterization of two distinct subsets of pluripotent stem cells from human fetal bone marrow, a CD34+, HLA-DR+, CD38- subset that can differentiate into all haematopoietic lineages, and a distinct more primitive subset, that is CD34+, HLA-DR-, CD38-, that can differentiate into haematopoietic precursors and stromal cells capable of supporting the differentiation of these precursors. These data represent, to our knowledge, the first identification of a single cell capable of reconstituting the haematopoietic cells and their associated bone marrow microenvironment.

ADP-ribosyl Cyclase↗
PubMedDate not supplied

Inheritance of organelle DNA sequences in a citrus-poncirus intergeneric cross.

Many land plants deviate from the maternal pattern of organelle inheritance. In this study, heterologous mitochondrial and chloroplast probes were used to investigate the inheritance of organelle genomes in the progeny of an intergeneric cross. The seed parent was LB 1-18 (a hybrid of Citrus reticulata Blanco cv. Clementine x C. paradisi Macf. cv. Duncan) and the pollen parent was the cross-compatible species Poncirus trifoliata (L.) Raf. All 26 progeny examined exhibited maternal inheritance of plastid petA and petD loci. However, 17 of the 26 progeny exhibited an apparent biparental inheritance of mitochondrial atpA, cob, coxII, and coxIII restriction fragment length polymorphisms (RFLPs) and maternal inheritance of mitochondrial rrn26 and coxI RFLPs. The remaining nine progeny inherited only maternal mitochondrial DNA (mtDNA) configurations. Investigations of plant mitochondrial genome inheritance are complicated by the multipartite structure of this genome, nuclear gene control over mitochondrial genome organization, and transfer of mitochondrial sequences to the nucleus. In this study, paternal mtDNA configurations were not detected in purified mtDNA of progeny plants, but were present in progeny DNA preparations enriched for nuclear genome sequences. MtDNA sequences in the nuclear genome therefore produced an inheritance pattern that mimics biparental inheritance of mtDNA.

Citrus↗
PubMedDate not supplied

The peripheral analgesic effect of meperidine in reducing propofol injection pain is not naloxone-reversible.

BACKGROUND AND OBJECTIVES: Meperidine is frequently used in general anesthesia and perioperative analgesia. In addition to its opioid action, meperidine possesses some local anesthetic properties. A preliminary study using the tourniquet venous retention technique found meperidine to be more effective in reducing propofol injection pain than fentanyl or morphine, both of which were slightly better than placebo. This study was undertaken to evaluate whether this peripheral analgesic effect of meperidine is affected by naloxone. METHODS: In a randomized, double-blind manner, after venous occlusion with a tourniquet, meperidine 40 mg was given intravenously to patients in group A (n = 31), meperidine 40 mg followed by naloxone 0.04 mg to group B (n = 32), meperidine 40 mg followed by naloxone 0.2 mg to group C (n = 30), and normal saline placebo to group D (n = 30). The venous retention of drug(s) was maintained for 1 minute, followed by tourniquet release and intravenous administration of propofol 100 mg. Pain assessment was made immediately after the propofol injection. RESULTS: All three groups given meperidine had significantly less propofol injection pain (P < .01 ) than the group given saline placebo, and there was no difference among groups A, B, and C. CONCLUSION: The peripheral analgesic effect of meperidine in reducing propofol injection pain is not mediated by its opioid activity.

Adjuvants, Anesthesia↗
PubMedDate not supplied

Arsenic trioxide induces apoptosis in cisplatin-sensitive and -resistant ovarian cancer cell lines.

Arsenic trioxide (As(2)O(3)), has been used for centuries in traditional Chinese medicine; it has considerable efficacy in the treatment of relapsed acute promyelocytic leukemia, inducing partial differentiation and promoting apoptosis of malignant promyelocytes. Although a number of studies have demonstrated that As(2)O(3) has potent activity against cell growth in a series of leukemia cell lines, little information is available regarding this compound's effect on cell growth in solid tumor cell lines. In this study, we investigated the effects of As(2)O(3)in vitro on ovarian cancer cell lines sensitive (3AO) and resistant (3AO/CDDP) to cisplatin. The 3-(4,5-dimethy-thiazoyl-2-yl)-2,5-diphenyl-tetrazolium bromide assay was used to evaluate cytotoxicity. Flow cytometric analysis was used to determine the apoptosis, cell cycle distribution. We clearly demonstrated that As(2)O(3) induced cell apoptosis and inhibition of cell growth in both the cell lines. Furthermore, we identified that As(2)O(3)-induced apoptosis involved Fas pathway. As(2)O(3) is an active agent against ovarian cancer cells and could be effective in the clinical treatment of ovarian cancer.

Apoptosis↗
PubMedDate not supplied

Pharmacokinetics of saquinavir-SGC in HIV-infected pregnant women.

PURPOSE: To evaluate saquinavir (SQV) pharmacokinetics, tolerance, and safety in 10 HIV-infected pregnant women between 14-32 weeks gestation. METHOD: This was a phase I, prospective, area-under-the-curve (AUC) targeted study. Antepartum treatment consisted of SQV 1200 mg tid, lamivudine 150 mg bid, and zidovudine 200 mg tid. The SQV targeted exposure was an 8-hour AUC (AUC(8)) of 3000 ng. h/mL; the study was to be halted if the first 4 participants did not achieve this AUC(8). Cord blood and plasma samples were collected in neonates at birth. RESULTS: Four women completed the SQV pharmacokinetic assessments. Exposure in all 4 patients was below the target AUC(8). Median (range) AUC(8) and trough (C8H) were 1672 (738-2614) ng. h/mL and 60 (<15-332) ng/mL, respectively. Oral clearance (CL/F) was 9.3 (5.1-16.6) L/h/kg and C(max) was 599 (177-953) ng/mL. Cord and neonate plasma concentrations were mostly undetectable; 1 of 5 infants was HIV-infected at 24 weeks. CONCLUSION: These data suggest highly variable SQV pharmacokinetics in pregnant women, and exposure at 1200 mg tid may not be adequate for longer term therapy; both the AUC(8) and C8H were considerably below average. Because ritonavir has been shown to significantly increase SQV concentrations, this combination should be further explored in this population.

Adult↗