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Biomedical subjects

C L Chen

Publications and source records attributed to C L Chen.

At least 271 records · Page 15Linked to original sources
PubMed1995

Characterization and regulation of two testicular inhibin/activin beta B-subunit messenger ribonucleic acids that are transcribed from alternate initiation sites.

We and others have shown that the inhibin/activin beta B-subunit gene is expressed differently in the gonads. Two species of 4.8- and 3.7-kilobase (kb) beta B-subunit messenger RNA (mRNA) with equal concentrations were identified in the testis, whereas 1 predominant 4.8-kb and a minor 3.7-kb mRNA were observed in the ovary. In this study, we analyzed the structures of these 2 mRNAs in rat testis and showed that both 4.8- and 3.7-kb beta B-subunit mRNAs were terminated at the region proximal to 2.2 kb down-stream from the translation stop codon. However, only 4.8-kb mRNA could be detected when RNA probes prepared from the 5'-region 1 kb up-stream from the translation start site were used for Northern blot analysis. Our observations suggested that the 2 heterogeneously sized beta B-subunit mRNAs are transcribed from different initiation sites. Transcription of the 4.8-kb mRNA was initiated at 3 adjacent nucleotides, GGA, 1.1 kb up-stream from the translation start codon ATG, whereas multiple transcription initiation sites spreading over 150 nucleotides upstream from the ATG codon were previously identified for 3.7-kb mRNA. Neither of the 2 transcripts contained TATA and CAAT boxes in their promoters. The 5'-flanking DNAs required for transcription of the 4.8- and 3.7-kb mRNA were examined by their ability to induce transient expression of the chloramphenicol acetyltransferase (CAT) gene in MA-10 Leydig tumor cells. A marked increase in CAT activity was detected when the 5'-flanking DNA for the 4.8- or 3.7-kb transcript was progressively shortened from its 5'-end. Maximal CAT activity was observed when -409 and -139 basepair beta B-subunit DNA up-stream from the 4.8- and 3.7-kb transcription initiation site, respectively, were fused to the CAT gene, suggesting the presence of a negative regulatory element(s) at the up-stream regions of these promoters. Although putative AP-2 sites were identified, treatment of the transfected cells with cAMP and/or phorbol 12-myristate 13-acetate did not apparently change CAT activity driven by either the 4.8- or 3.7-kb promoter. Our results concluded that 1) the two inhibin/activin beta B-subunit mRNAs were transcribed from different initiation sites; 2) both promoters may be controlled by up-stream negative regulatory elements; and 3) neither of these promoters is responsive to cAMP and/or phorbol esters under the conditions employed.

Activins↗
PubMed1995

[The incidence and mortality rates of head injuries in Kaohsiung City, Taiwan (1991-1992)].

Head injury is a leading cause of mortality, morbidity and disability in Taiwan. This study was based on data from the investigation of head injuries in Kaohsiung City, Taiwan, during the period July 1, 1991 to June 30, 1992. The 3729 cases identified represented an overall incidence rate of 267/100,000--359/100,000 for males and 170/100,000 for females. The highest incidence rate was seen in the elderly group, followed by the 20-29 year age group. The population with the highest risk was males aged 20-29 years, with an incidence rate of 585/100,000. Seventy percent of all cases were from motor vehicle-related causes, followed by falls (15.3%) and assaults (8.7%). Of the motor vehicle-related head injuries, 70.9% resulted from motorcycle accidents. The incidence rate of motor vehicle head injuries was 188/100,000--248/100,000 for males and 125/100,000 for females. At all ages motor vehicle head injuries were higher in males than in females. Mortality rates from head injuries were 26/100,000--38/100,000 for males and 14/100,000 for females. The overall case fatality rate was 10%, and 61% of all deaths occurred prior to hospitalization. The case fatality rate was highest in older age groups. Initial clinical assessment was recorded using the Glasgow Coma Scale. Eighty-one percent of the cases were considered mild, and 19% moderate to severe in degree including 367 deaths. The males and the aged not only had a higher incidence of head injuries but also had a higher proportion of more severe ones. These findings indicate that head injuries are nonrandom and likely to occur in certain types of individuals under certain circumstances.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗
PubMed1995

[Head injuries in children and adolescents: treatment and outcome].

We conducted a retrospective study to investigate the treatment and outcome of head injuries in children and adolescents in Taiwan. The study group consisted of 820 children and adolescents with head injuries admitted to Chang Gung Memorial Hospital from January 1985 to December 1989. The data were obtained from chart review and questionnaire. The cases were divided into four age-groups: group A (0-4 years old), group B (5-9 years old), group C (10-14 years old) and group D (15-17 years old). Computed tomogram of the brain was performed in 92% of the cases and most had abnormal findings. The frontal, temporal and parietal regions in that order accounted for the most focal sites of injuries on computed tomogram. Brain and other major surgery were necessary in 23.7% and 11.3% of the cases, respectively. Of the 15.3% of cases with seizures, most had early-onset seizures. A questionnaire of 398 survivors, showed that most patients achieved a good recovery level (94.2%) on the Glasgow outcome scale, a normal recovery (83.8%) of motor function and independent walking (96.0%) in locomotion. Vision and hearing were impaired in only 9.3% and 6.0% of cases, respectively. Approximately 97% of the patients aged 5 years or over recovered to be independent in their daily living activities and in normal communication. There were no significant differences in their above outcome-analyses among the different age-groups.

Adolescent↗
PubMed1995

Pharmacokinetics and plasma protein binding of the new potent class III antiarrhythmic agent 3-[4-(1H-imidazol-1-yl)benzoyl]-7-isopropyl-3, 7-diazabicyclo[3.3.1]nonane dihydroperchlorate.

GLG-V-13 (3-[4-(1H-imidazol-1-yl)benzoyl]-7-isopropyl-3,7-diazabicyclo [3.3.1] nonane dihydroperchlorate, CAS 155029-33-7) has been shown to be a potent class III antiarrhythmic agent. The oral and intravenous pharmacokinetics and plasma protein binding of GLG-V-13 in dogs and in rabbits have now been investigated. Plasma GLG-V-13 concentration-time profiles, following an i.v. bolus dose of 6 mg/kg, were fitted to a 2-compartment model. The volume of distribution at steady state (Vd(ss)), the total systemic (ClB), and the elimination half-life (t1/2 beta) were 4.441 l/kg, 1.113 l/h/kg, and 2.485 h in dogs and 3.723 l/kg, 1.548 l/h/kg, and 1.401 h in rabbits. Following i.v. dosing, approximately 9.38% of the parent compound was excreted in dogs urine (0-72 h). Changes in plasma GLG-V-13 concentrations, after oral administration of GLG-V-13 (6 mg/kg), were best described by the 1-compartment pharmacokinetic model. The tmax and Cmax were 1.69 h, 0.54 mg/l in dogs and 1.44 h, 0.35 mg/l in rabbits. On oral administration, GLG-V-13 was moderately eliminated (t1/2kel' 1.867 h-1 in dogs and 3.961 h-1 in rabbits, respectively). Oral bioavailability was estimated to be 53.2% +/- 11.3% in dogs and 66.7% +/- 7.7% in rabbits. About 8.74% of the oral dose (6 mg/kg) was excreted via the dog urine (0-72 h). In vitro binding of GLG-V-13 to dog plasma protein was 29.4 +/- 9.90% (from 0.5 to 4 mg/l). Ex vivo binding of GLG-V-13 to dog plasma protein was 10.4 +/- 7.20%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Nodular amyloidosis of the lung and the breast mimicking breast carcinoma with pulmonary metastasis.

Nodular amyloidosis of the breast and lung is a rare condition of unknown aetiology. The disease runs a benign course, but offers a diagnostic problem due to nonspecific histological features. We describe the case of a 56 year old woman with a 5 year history of multiple nodules of both lungs and left breast, clinically mimicking breast carcinoma with pulmonary metastasis. To our knowledge, this is the first case of cytologically proven amyloidosis diagnosed by ultrasound-guided percutaneous transthoracic fine-needle aspiration of pulmonary nodules.

Amyloidosis↗
PubMed1995

Rebleeding rate of various stigmata of recent hemorrhage in peptic ulcer bleeding with different severity.

The stigmata of recent hemorrhage (SRH) have been used as a factor for predicting peptic ulcer rebleeding. In previous studies, the rebleeding rate of the visible vessel varied. A hypothesis had been proposed stating that the evolution of the color of the stigmata depends on the point in the healing process of the blood clot on the bleeding ulcer. This retrospective study evaluates the rebleeding rates associated with various colors of stigmata of recent hemorrhage. Of a total of 623 cases of peptic ulcer bleeding (474 male and 149 female, with a mean age of 59 years old), there were 232 gastric ulcers, 369 duodenal ulcers, and 22 stomal ulcers. Stigmata of recent hemorrhage were found in 387 cases (62%). The overall rebleeding rate for those with gastric ulcers was higher than for those with duodenal ulcers (24.2% versus 16.3%, p<0.05), especially for oozing and sentinel clots, the rebleeding rates for active bleeding, blood clots, sentinel clots, and others were 35%, 24.8%, 17%, and 11.3% respectively. The red clot of stigmata of recent hemorrhage had a slightly higher rebleeding rate than the black clot, but the difference was not statistically important. Furthermore, the 5 duodenal ulcers with white sentinel clots experienced no rebleeding. When comparing the rebleeding rates between groups with massive and minor bleeding, a significantly higher rebleeding rate was found in the massive bleeding group (50.5% versus 6.6%, p < 0.001). It can thus be seen that the different types of stigmata of recent hemorrhage represent different stages in the healing process of a bleeding ulcer. A white sentinel clot had a change of not rebleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Chi-Square Distribution↗
PubMed1995

Pharmacokinetics of intravenously administration of prednisolone in the horse as determined by radioimmunoassay.

A radioimmunoassay was developed for prednisolone using IgG purified from rabbit antiserum. The assay was employed to determine the pharmacokinetics of prednisolone following intravenous administration of 450 mg of prednisolone sodium succinate (Solu Delta Cortef) to five adult Thoroughbred horses. The RIA had a sensitivity of 2 ng/ml and was relatively specific. It had cross-reactivity with 21-deoxycortisol (83.3%) cortisol (27.8%), 11-beta-hydroxyprogesterone (39.2%) and 17-hydroxyprogesterone (50%). However, it did not cross-react with naturally occurring steroids (cholesterol, testosterone, estradiol or progesterone) or synthetic steroids (betamethasone, methylprednisolone, prednisone or triamcinolone). Radioimmunoassay of the horse serum samples detected the presence of prednisolone for 5 to 7 hours post administration. The pharmacokinetic parameters tested and their means were a half-life of 1.150 +/- 0.233 (+/- SEM) hours, an excretion constant of 0.686 +/- 0.018 Ke/hr, a volume of distribution of 607 +/- 109 ml/kg, and a clearance rate of 374 +/- 47 ml/hr/kg. RIA also detected the presence of prednisolone in the urine beginning one hour post administration. The prednisolone in the urine increased significantly at 2 hours and reached a peak at 4 hours post administration. The urinary levels decreased at 5, 6, and 7 hours and peaked again at 8 hours. The level then gradually decreased and reached the minimal detectable levels in 48 hours. These results showed that the RIA was sensitive and relatively specific for the determination of prednisolone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Inhibition of locus coeruleus neurons by serotonin at high doses.

Using brain slice and intracellular recording techniques, this study was conducted in the attempt to evaluate whether serotonin (5-HT) is able to directly influence neuronal activities of the locus coeruleus (LC). LC neurons in the brain slice preparation show spontaneous firing in the absence of synaptic input; neurons in this work had firing rates ranging from 0.18-3.6 Hz (mean = 1.18 +/- 0.26 Hz). Concentrations of 5-HT from 30 to 300 microM were used, which reversibly decreased the spontaneous firing rate in 30 out of 36 LC neurons tested. In testing those cells with more than one concentration, the effect was dose-dependent. For LC neurons which showed complete block of firing by 5-HT (300 microM), the latency to block was found to be directly related to the firing rate. In addition to the inhibition of spontaneous firing, 5-HT (300 microM) also caused a 0-5 mV (mean = 3.2 mV, n = 10) hyperpolarization associated with a 2.2-21% (mean = 11.5%, n = 10) decrease in input resistance. Lower concentrations of 5-HT (30-100 microM) did not produce any significant change in membrane potential or input resistance in neurons of the LC. The 5-HT receptor antagonist methysergide (10 microM) was tested in 6 cells. Methysergide antagonized the 5-HT-induced inhibition of firing, hyperpolarization and reduction in input resistance. We concluded that 5-HT has inhibitory actions at high doses when applied to LC neurons in the brain slice preparation. 5-HT's inhibitory effects on LC neurons appear to be mediated by 5-HT receptors since they are antagonized by methysergide.

Animals↗
PubMed1995

[Head injuries in children and adolescents: causes and natures].

To investigate the nature of exposure factors, and effectiveness of countermeasures in head injuries in children and adolescent of Taiwan area, we conducted a retrospective study on 820 children and adolescents with head injuries consecutively admitted to Chang Gung Memorial Hospital from January 1985 to December 1989. We analyzed the data by chart review and divided the cases into four age-groups: group A (0-4 years old), group B (5-9 years old), group C (10-14 year old) and group D (15-17 years old). The boy to girl ratio was 2.43. The largest proportions of head injuries were the adolescents in group D. The most common cause of head injury was traffic accidents (74%); while the falls were contributed the main cause in other studies. In all group A, B and D, the majority of traffic accidents were pedestrian injury; while in group D, the motorcyclists or car drivers were responsible for the accidents. Fall from height was the major cause of fall in all four age-groups, but it was fall from bicycle or during play or sports in group C. Injuries were most common in summer and clustered at afternoon in all patients. Majority of head injuries occurred outdoors. Most children and adolescents suffered from mild head injury, but there were still 203 cases with severe head injury (24%). Eighty-one cases (9.9%) were either discharged in critical condition or died at the hospital. There were no significant differences in mortality among four age-groups.

Accidental Falls↗
PubMed1995

Characterization of a prolactin-synthesizing rat pituitary cell line immortalized by the temperature-sensitive mutant SV40.

A prolactin (PRL) synthesizing rat anterior pituitary (AP) cell line named tAP-CLC-2 was established by transformation with mutant temperature-sensitive A (tsA) simian virus 40 (SV40). The transformed cells were temperature-sensitive for morphology, cell propagation, and expression of phenotypic genes. Monolayer primary rat AP cells were transfected with a mutant SV40 (tsA 205) at 10 times the multiplicity of infection (MOI) at 34 degrees C. After cell clones formed, each clone was isolated and transferred to separate flask until sufficient cells were grown for freezing and characterization. At the permissive temperature (34 degrees C), these cells were spindle-shaped and grew rapidly like tumor cells. However, at the nonpermissive temperature (40 degrees C), the cells exhibited a rounded shape and ceased to propagate because the gene for maintenance of transformation was not expressed. Cell extracts from the cell line tAP-CLC-2 showed an inhibition curve parallel to that of normal rat pituitary cell extracts in a PRL radioimmunoassay (RIA). The gel filtration profile of immunoassayable PRL obtained from fast performance liquid chromatography (FPLC) showed that tAP-CLC-2 cell extract exhibited a PRL peak coincidental with primary rat pituitary cell extracts. Western blot showed that cell extracts from the tAP-CLC-2 cell line and from normal rat pituitary glands shared a similar, major immunoreactive PRL band. The tAP-CLC-2 cell line was responsive to estradiol (E 2; 10(-7) M), progesterone (10(-8) M), and gonadotropin-releasing hormone (GnRH; 10(-9) M) treatments. These hormonal treatments increased (p < 0.05) cell PRL content. Interestingly, treatment with a high dose (10(-7) M) of ovine luteinizing hormone (oLH) also increased (p < 0.05) PRL content in the cell line; a low dose (10(-9) M) of oLH did not. The cell line appeared to synthesize growth hormone (GH) as well. These results indicate this cell line has properties shared by primary AP cells and can provide a unique model for the study of the synthesis and gene regulation of PRL in vitro.

Animals↗
PubMed1994

Construction of Tn917ac1, a transposon useful for mutagenesis and cloning of Bacillus subtilis genes.

A Tn917 derivative was constructed for the purposes of mutagenesis and cloning of Bacillus subtilis genes. This transposon, Tn917ac1 (4.6 kb), consisted of terminal inverted repeats of Tn917, the res sequence, a ColE1 origin of replication (ori) and two drug-resistance genes. The plasmid carrying this transposon, named pD917, contained the erm-tnpR-tnpA gene cluster of Tn917 and a temperature-sensitive ori of pE194. For the purpose of mutagenesis, transposition of Tn917ac1 was induced by culturing strains harboring pD917 in a medium containing a low concentration of erythromycin. Cells with a Tn917ac1 insertion in the chromosome were selected on agar containing chloramphenicol after heat treatment to eliminate the plasmidic form of pD917. DNA fragments adjacent to Tn917ac1 could be cloned by restriction digestion of the chromosomal DNA and by transforming the self-ligated restriction fragments into Escherichia coli. Sequence analysis revealed that Tn917ac1 was integrated into the chromosome of B. subtilis by transposition in a recE strain and by transposition or integration of pD917 in a wild-type strain. Tn917ac1 has been demonstrated to be useful for mutating and cloning of the genes involved in the biosynthesis of fengycin in B. subtilis F29-3.

Bacillus subtilis↗
PubMed1994

Vascular patterns of gestational trophoblastic tumors by color Doppler ultrasound.

BACKGROUND: Destruction of uterine vasculature is a common phenomenon in gestational trophoblastic tumors. The authors categorized such uterine vasculature by color Doppler ultrasound and studied its clinical significance. METHODS: Color Doppler ultrasound was performed in 28 patients with gestational trophoblastic tumors. The vascular morphologic manifestations were recorded, and the peak systolic velocity and resistance index of uterine artery were calculated. Serum beta-human chorionic gonadotropin (hCG) levels were measured periodically to monitor chemotherapy response. Seventeen uneventful postmole uteri were used as controls. Two-tailed Student's t-test and Fisher's exact test were used for statistical analysis. RESULTS: The gestational trophoblastic tumors were categorized as diffuse type (N = 7), lacunar type (N = 16), and compact type (n = 5) according to their vascular patterns. The mean serum beta-hCG level at diagnosis in diffuse type lesions (6608 +/- 6320 mIU/mL) was significantly lower than in the lacunar type (40462 +/- 39735 mIU/mL; P = 0.04) and compact type (212114 +/- 205126 mIU/mL; P = 0.02), whereas the level in compact type lesions was significantly higher than in the lacunar type (P = 0.003). Lacunar type lesions exhibited a significantly lower uterine artery resistance index (0.51 +/- 0.13) than diffuse type (0.66 +/- 0.10; P = 0.03) or compact type lesions (0.70 +/- 0.06; P = 0.02). All lesions exhibited significantly higher peak systolic velocity than control subjects (P < 0.001); however, no significant difference was observed among them. Brief courses (< 5 cycles) of chemotherapy cured more diffuse type (6 of 7) than lacunar type (3 of 15, P = 0.006) or compact type lesions (0 of 5, P = 0.008). Histopathologic diagnosis was available for 11 lesions. They were invasive mole in seven lacunar type lesions and choriocarcinoma in four compact type lesions. CONCLUSION: Vascular morphologic patterns of gestational trophoblastic tumors by color Doppler ultrasound correlated well with beta-hCG levels, uterine hemodynamics, chemotherapy response, and possibly the histopathologic diagnosis.

Arteries↗
PubMed1994

Characterization of two promoters of a rat pregnancy-specific glycoprotein gene.

Pregnancy-specific glycoproteins (PSGs) are the major placental glycoproteins, that together with the carcinoembryonic antigens comprise a subfamily within the immunoglobulin superfamily. In order to develop an animal model for understanding the molecular mechanisms underlying the control of PSG expression, we isolated and characterized cDNA and genomic clones encoding a rodent PSG, rnCGM3. The rnCGM3 cDNA is 2761 bp in length and contains an open reading frame that encodes a 475 amino acid polypeptide with a domain arrangement of L1N1-L2N2-L3N3-A. The sequence in 5'-untranslated and L1 regions of rnCGM3 is identical to a previously identified cDNA, rnCGM6. The transcription initiation sites of both genes are located at nucleotide -197 upstream of the translation start site. In transient transfection assays using a chloramphenicol acetyltransferase (CAT) reporter gene, we demonstrated that DNA elements at nucleotides -326 to -185 (PI) and -147 and -86 (PII) relative to the translation start site of rnCGM3 could both function as promoters. The downstream promoter, PII, which is located within the first exon, shares high sequence identity with the minimal promoters of human PSG genes. Electrophoretic mobility shift assays (EMSAs) showed that protein factors in placental cell extracts formed three complexes (PIICI, PIICII, and PIICIII) with the PII promoter element. The PIICIII complex was also observed by DNase I footprinting analysis. Unlike PII, the upstream promoter, PI, contains a TATA box. DNase I footprinting analysis revealed two nuclear protein binding sites at nucleotides -311 to -290 (PISI) and -257 to -239 (PISII) in PI. EMSAs showed that protein factors in placental cell extracts bound to both sites and deletion of either site markedly reduced CAT expression. PISII contains a palindromic motif, TGTTGCTCAACA, and protein cross-linking and Southwestern hybridization analyses demonstrated that the protein factor binding to PISII had an apparent molecular mass of 40 kDa.

Amino Acid Sequence↗
PubMed1994

Identification of T-cell receptor alpha-chain genes in the chicken.

T-cell receptor (TCR) alpha-chain (TCR alpha) and beta-chain (TCR beta) genes are well characterized in mammals, while only TCR beta genes have been identified in other vertebrates. To identify avian TCR alpha genes, we used monoclonal anti-CD3 antibodies to isolate chicken TCR alpha for peptide sequence analysis. Degenerate oligonucleotide probes were then used to isolate a candidate TCR alpha cDNA clone that hybridized with a 1.7-kb mRNA species present only in alpha beta T cells and in tissues populated by these cells. Southern blot analysis revealed gene rearrangement in thymocytes and alpha beta T-cell lines. The TCR alpha cDNA candidate encoded an open reading frame of 275 amino acids, the predicted variable (V)-, joining (J)-, and constant (C)-region amino acid sequences of which shared approximately 40%, 60%, and 25% homology with corresponding mammalian sequences. A single C alpha gene and approximately 25 V alpha genes were identified by using region-specific probes. The V alpha cDNA probe isolated from a V beta 1+ cell line reacted with transcripts from one of five V beta 2+ cell lines, suggesting shared use of V alpha genes by V beta 1+ and V beta 2+ T cells and the existence of other V alpha gene families. A genomic V alpha sequence was flanked by classical recombination signal sequences but, unlike previously defined V genes, the leader and V alpha region were encoded by a single exon. The data indicate evolutionary conservation of the basic TCR alpha gene structure in birds and mammals.

Amino Acid Sequence↗
PubMed1994

Characterization of avian natural killer cells and their intracellular CD3 protein complex.

Natural killer (NK) cell activity appears to be conserved throughout vertebrate development but NK cells have only been well characterized in mammals. Candidate NK cells have been identified in the chicken as cytoplasmic CD3+ and surface T cell receptor (TCR)/CD3- (TCRO) lymphocytes that often express CD8. The fact that the TCRO cells are abundant in the embryonic spleen before T cells enter this organ allowed us to cultivate the embryonic TCRO cells using growth factors derived from activated adult lymphocytes. These TCRO cells were cytotoxic for an NK target cell line. They expressed cell surface CD8, a putative interleukin-2 receptor, CD45 and a receptor for IgG, but did not express CD4, major histocompatibility complex class II or immunoglobulin. Biochemical analysis of the cytoplasmic CD3 antigen revealed two of the three CD3 gamma, delta and epsilon homologues, and RNA transcripts for the third. The CD3 monoclonal antibody also precipitated a 32-kDa dimer that may represent a heterodimer of different CD3 constituents. TCR alpha and beta gene transcripts were not detected in the TCRO cells. These results indicate that the avian TCRO cell is the mammalian NK cell homologue. The shared evolutionary features of T cells and NK cells in birds and mammals support the idea that they derive from a common progenitor.

Animals↗
PubMed1994

Factors associated with viremia and elevated transaminase levels in asymptomatic hepatitis D virus-infected risk groups.

To detect hepatitis D virus (HDV) RNA in asymptomatic HDV-infected risk groups, Northern blot hybridization was carried out using a strand-specific riboprobe. Univariate and multivariate analyses were carried out to evaluate factors associated with HDV viremia and elevated transaminase levels in these subjects. Two (15%) of 13 antibody to HDV (anti-HDV) -positive intravenous drug addicts, 15 (33%) of 45 anti-HDV positive prostitutes, and 6 (40%) of 15 anti-HDV positive brothel goers had detectable serum HDV RNA. Older age (> 31 years old) was negatively associated with HDV RNA (P < .04), while hepatitis B e antigen (HBeAg) was positively associated with it (P < .002) in univariate analysis. Only HBeAg was still significant in multivariate analysis (P < .05). Of the 76 asymptomatic anti-HDV positive case, 28 (37%) had mildly elevated serum ALT levels and only 5 (7%) had ALT levels more than twice normal (> 80 U/L). HBeAg (P < .05) and HDV RNA (P < .02) were two factors associated with ALT elevation in univariate analysis, and HDV RNA was the only significant factor in multivariate analysis (P < .005). In summary, active replication of HBV seemed to be of help for the assembly of HDV and viremia. However, active replication of HDV was associated mostly with mildly elevated ALT levels in these subjects. These cases may represent a particular group in the disease spectrum of HDV infection.

Adolescent↗
PubMed1994

Characterization of a major cell wall antigen and potential adhesin in three strains of Candida albicans.

Selected strains of Candida albicans were examined to reveal the surface antigenicity and biochemical nature of major cell wall proteins that also were shown to serve as cellular adhesins on human buccal epithelial cells. Confirmation of the adhesive properties of these cells was made by scanning electron microscopy and immunofluorescence microscopy. Particular attention was directed at the clinical isolate KM-302. By means of indirect immunofluorescence staining, the KM-302 blastoconidia absorbed rabbit anti-C. albicans ATCC-32354 serum, revealing specific localization of surface antigens on germ tubes and pseudohyphae. Extracellular polymeric material and the cell wall extract of C. albicans KM-302 blastoconidia were found to contain a major surface antigen of 49 kDa that exhibited 42% adhesion inhibition in vitro. Of considerable significance is that immunogold localization by electron microscopy showed the antigen to be almost exclusively cell wall bound. This major antigen, identified in affinity and gel filtration chromatography fractions, was composed of 4% carbohydrate and 95.7% protein and had an isoelectric point of 6.1. The major antigen also showed a high level of similarity with that of C. albicans strain SC-5314 inasmuch as the major antigen of that strain had carbohydrate and protein compositions of 4 and 95.5%, respectively. Both of these strains also possessed the same percent of adhesion inhibition on human buccal epithelial cells.

Antigens, Fungal↗