Showing papers by "Taipei Veterans General Hospital published in 1988"

Sequence duplication and internal deletion in the integrated human papillomavirus type 16 genome cloned from a cervical carcinoma.

Abstract: Integrated human papillomavirus type 16 (HPV16) sequences were cloned from a cervical carcinoma and analyzed by restriction mapping and nucleotide sequencing The viral integration sites were mapped within the E1 and E2 open reading frames (ORFs) The E4 and E5 ORFs were entirely deleted An internal deletion of 376 base pairs (bp) was found disrupting the L1 and L2 ORFs Sequencing analysis showed that an AGATGT/ACATCT inverted repeat marked the deletion junction with two flanking direct repeats 14 and 8 bp in length A 1,330-bp sequence duplication containing the long control region (LCR) and the E6 and E7 ORFs was also found The duplication junction was formed by two 24-bp direct repeats with 79% (19 of 24) homology located within the LCR and the E2 ORF of the prototype viral genome, respectively This observation leads us to propose that the initial viral integration involved an HPV16 dimer in which the direct repeats in tandem units recombined, resulting in reiteration of only a portion of the original duplication A guanosine insertion between nucleotides 1137 and 1138 created a continuous E1 ORF which was previously shown to be disrupted Results from this study indicate that sequence reiteration and internal deletion in the integrated, and possibly in the episomal, HPV16 genome are influenced by specific nucleotide sequences in the viral genome Moreover, reiteration of the LCR/E6/E7 sequences further supports the hypothesis that the E6/E7 ORFs may code for oncogenic proteins and that regulatory signals in the LCR may play a role in cellular transformation

Sodium-Valproate-Induced Interstitial Nephritis

Abstract: A 5-year-old Chinese girl had had absence seizures and received sodium valproate (VPA) treatment which provided good control. Six months later, she developed interstitial nephritis with proteinuria an

Controlled fed‐batch fermentation of recombinant Saccharomyces cerevisiae to produce hepatitis B surface antigen

Abstract: We have performed controlled fed-batch fermentation experiments to compare the production level of hepatitis B surface antigen (HBsAg) by recombinant yeast Saccharomyces cerevisiae strains (YNN27/pYBH-1, YNN27/ p2micro-S11, YNN27/pDCB-S2) containing plasmid vector with alcohol dehydrogenase (ADH1), acid phosphatase (PHO5), and glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, respectively. Yeast cell concentrations of 15-35 g dry cell weight/L were obtained. By limiting phosphorous concentration, HBsAg expression level for the YNN27/p2micro-S11 strain with inducible PHO5 promoter reached 0.2-0.3 mg/L. By controlling nutrient addition rate and dissolved oxygen concentration, HBsAg concentrations of 3-10 mg/L were achieved in 60-70 h fermentation using the YNN27/pDCB-S2 strain with the constitutive GPD promoter.

Insulin controlled-release microcapsules to prolong the hypoglycemic effect in diabetic rats.

Abstract: A solvent evaporation process was employed for preparing insulin microcapsules by using biodegradable polymers [polylactic acid (PLA), HP-55] and non-biodegradable polymers [ethylcellulose (EC), ethylenevinyl acetate (EVA)]. The release behavior of insulin microcapsules in pH 7.4 phosphate buffer solution was undertaken by a continuous flow column method. Seven types of insulin microcapsules were respectively injected into the flanks of fasting-diabetic SD rats induced by streptozotocin. The glucose levels and insulin concentrations in the blood were periodically sampled from the tail and assayed by a glucose analyzer and RIA method. Body weights were measured twice per week. The release rate was controllably dependent on the polymer used. The PLA micro-capsules could maintain normoglycemia only for five days, whereas the (PLA+1%EVA) microcapsules exhibited two times the hypoglycemic effect of PLA microcapsules, but (PLA+1%EVA) microcapsules treated with 4% wax extended the duration of hypoglycemic effect...

Characteristics of Five Monoclonal Antibodies to Major Allergens of the Short Ragweed Pollen

Abstract: Monoclonal antibodies against major allergens of the short ragweed pollen were produced by fusion of NS-1 cells with splenic cells from BaLB/C mice that had been immunized separately with the major al

Serial cell-mediated immunological changes in terminal uremic patients on continuous ambulatory peritoneal dialysis therapy.

Abstract: To investigate the mechanism of immunologic defects in uremia, we examined the cell-mediated immunity in 20 uremic patients with well balanced dietary assessments before continuous ambulatory peritoneal dialysis (CAPD) therapy and the serial changes in cell-mediated immunity 3, 6, 9, and 12 months after therapy. Absolute lymphocyte count, active T, total T, OKT4, OKT8, and B-cell levels were significantly lower in uremic patients than in controls, but progressively increased after CAPD treatment. The lymphoproliferative responses to mitogens decreased and were more evidently suppressed in the presence of autologous plasma. The suppressive effect of autologous plasma could be abolished by indomethacin treatment. The plasma prostaglandin E2 level, which was increased in uremic patients, decreased after CAPD treatment. These results suggest that prostaglandin E2 may play an important role in the suppression of T-cell function. The T-cell response to the stimulation of autologous non-T cells (autologous mixed-lymphocyte reaction; AMLR) in uremic patients was also low in patients before CAPD treatment. The patients' autoreactive T cells could suppress AMLR, and so did the supernatant from AMLR and isolated T-cell culture of uremic patients. These results suggest the existence of suppressor autoreactive T cells which can release suppressor factor(s). However, to our surprise, the autoreactive T-cell proliferation increased, and the suppressive effect of the supernatant was abolished after CAPD therapy. The mechanism for this peculiar phenomenon is not known and deserves further investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of the growth of human colorectal carcinoma cells (LS174T) by radiolabeled monoclonal antibody (131I-MAbC27) in tissue culture and nude mice.

Abstract: A monoclonal antibody against carcinoembryonic antigen (CEA), MAbC27, and its F(ab′)2 fragments were prepared and labeled with131I. They effectively suppressed the growth of a human colorectal carcinoma cell line, LS174T, both in culture medium and in inoculated nude mice, whereas131I-labeled normal mouse immunoglobulin or131I itself did not have similar effects. Intravenous injection of131I-MAbC27 or131I-MAbF(ab′)2 following inoculation of carcinoma cells suppressed their growthin vivo. The suppression effect was even more effective when intact antibody rather than its F(ab′)2 fragments was used, especially when the treatment was repeated. This study indicates that radiolabeled MAbC27 may be used as a therapeutic agent in CEA-secreting human colorectal carcinomas.

The molecular basis of HbH disease in Taiwan.

Abstract: We have determined the molecular characteristics of α-thalassemia in 12 HbH subjects from Taiwan by restriction endonuclease mapping with α-and ζ-specific probes. We have found four types of defects in the α-thalassemia-2 genetic determinant: α3.7 type I; α4.2; αCS; and ααT. All HbH subjects carried the ——SEA genotype in the α-thalassemia-1 determinant. At least two different subtypes of ——SEA genotype were observed in this study.

Monoclonal antibodies specific for human IgE and their clinical applications.

Abstract: By applying the hybridoma technique, two mouse anti-human Immunoglobulin E (IgE) monoclonal antibodies, designated as E17-58 and E20-62, were generated and characterized. E17-58 was a murine IgG2b with an affinity constant of 4 x 10(8)l/mole. E20-62 was a murine IgG1 with an affinity constant of 1 x 10(8) l/mole. These two antibodies recognized different antigenic determinants specific to the IgE molecule. They were used in combination to quantify the total serum IgE level of forty-nine persons. Data obtained correlated highly with that obtained by using the Pharmacia PRIST Kit (r = 0.91). E17-58 was also used to detect the anti-Aspergillus specific IgE of twenty-one atopic patients by a radioimmunosorbent test. The positive rate detected correlated very well with the skin test (p less than 0.05). In addition, in the Western blot system, these monoclonal antibodies were capable of identifying IgE binding components of crude allergen extracts. Extracts from pollens of Bermuda grass were evaluated, and a new major allergenic component with a molecular weight of 40 kd was identified.

Decreased antibody-dependent cellular cytotoxicity in minimal change nephrotic syndrome.

Abstract: Secondary IgG response to a tetanus toxoid booster and in vitro measurement of immunoglobulin synthesis, antibody-dependent cellular cytotoxicity (ADCC) and gamma-interferon (IFN-gamma) production were evaluated in 20 healthy controls and in 17 children with minimal change nephrotic syndrome (MCNS), during the acute nephrotic phase and 6 months after remission. Defective responses were observed in all but IFN-gamma production during the acute nephrotic phase; these improved with disease remission. There was a significant correlation between decreases in vitro IgG production and ADCC reaction. These data indicate that defective antibody production is associated with decreased ADCC during the acute nephrotic phase of MCNS.

Localization of human colorectal carcinoma xenografts in mice using radiolabeled monoclonal antibody to carcinoembryonic antigen.

Abstract: A mouse IgG1 monoclonal antibody (MAbC27) with high affinity for human carcinoembryonic antigen (CEA) has been used in vitro and in vivo for study of human colorectal carcinoma (CRC). After introduction to tumor-bearing mice, the distribution of radiolabeled MAbC27 and its F(ab')2 fragments was analyzed by direct measurement of radioactivity in the tumor and in normal organs as well as by whole-body scanning. Radiolabeled MAbC27 and its F(ab')2 were used successfully in localizing tumor xenografts in mice 40 and 20 hr after inoculation, respectively. A tumor as small as 60 mg (4.2 mm in diameter) was visualized by labeled F(ab')2. Circulating CEA, up to 200 micrograms per mouse did not prevent successful tumor imaging. This study indicates that the MAbC27 is highly useful in detection and localization of CRC in mice.

Molecular analysis of hemoglobin H disease in Taiwan

Abstract: The molecular basis of seven Chinese patients in Taiwan with hemoglobin H disease was investigated and was found to be heterogeneous in the mutation type. They were alpha-thalassemia-1 mutation combined with hemoglobin Constant Spring, an undetermined nondeletion form of alpha-thalassemia and a deletion form of alpha-thalassemia-2 mutations. The alpha-thalassemia-1 mutation was shown to be the --SEA type I haplotype.

Enhanced enzyme activity after incubation with zinc can be used to distinguish heterozygotes of Pompe's disease.

Abstract: In an attempt to identify heterozygotes for Pompe's disease, the acid alpha-D-glucosidase activity at pH 4 in phytohemagglutinin-stimulated lymphocytes was measured. In the standard assay an overlap in the enzyme activity between normal controls and obligate heterozygotes was demonstrated. When the assay was modified by adding zinc chloride into the incubation mixture, the enzyme activity of the lymphocyte homogenates did not change. However, the enzyme activity increased dramatically after intact lymphocytes were preincubated with zinc chloride. There was no more overlap in the acid alpha-D-glucosidase activity between normal controls and obligate heterozygotes when lymphocytes were incubated 1 h with 10(-4) mol/liter zinc chloride or 2 h with 10(-3) or 10(-4) mol/liter zinc chloride. This modified enzyme activity should facilitate improved heterozygote detection.

Erythrocyte hydroxymethylbilane synthase activity in a Chinese family with acute intermittent porphyria.

Abstract: Etude d'une famille chinoise avec analyse de l'activite enzymatique de l'uroporphyrinogen I synthase erythrocytaire et du porphobilinogen urinaire