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Biomedical subjects

D Huang

Publications and source records attributed to D Huang.

At least 271 records · Page 15Linked to original sources
PubMed1989

Epstein-Barr virus (EBV)-containing nasopharyngeal carcinoma cells express the B-cell activation antigen blast2/CD23 and low levels of the EBV receptor CR2.

Anaplastic nasopharyngeal carcinoma (NPC) cells invariably harbor the Epstein-Barr virus (EBV) genome, an association that is unique among human virus-associated cancers. Although EBV is able to replicate in epithelial cells, results with expression of the EBV receptor (complement receptor type 2 [CR2]; also called CD21) in normal and malignant epithelial cells are conflicting. We grew five different EBV-associated NPC tumors in nude mice, and by using a sensitive transcriptional assay, we detected a very weak transcription signal of the EBV receptor CR2 gene in these cells. This suggests that low levels of EBV receptor may be expressed by malignant epithelial nasopharyngeal cells. The gene coding for Blast2/CD23, a B-cell activation molecule induced by EBV, was transcribed in three of the transplanted NPC tumors. The soluble form of the Blast2/CD23 protein was also detected in medium taken from short-term cultures of the same NPC cell lines. In contrast to the lymphoid system, in which Blast2/CD23 expression is associated with EBV nuclear antigen (EBNA2) expression, no EBNA2 protein could be detected in these NPC epithelial cells. Our study represents the first demonstration of Blast2/CD23 expression in epithelial cells. As the soluble form of the Blast2/CD23 protein possesses growth factor activity associated with EBV-induced B-cell immortalization, these results suggest a possible role for this molecule in the pathogenesis of NPC.

Animals↗
PubMed1989

Effects of thyroid status on atrial natriuretic peptide release from isolated rat atria.

The effect of thyroid hormone on circulating levels of atrial natriuretic peptide (ANP) was studied in experimental hyperthyroid and hypothyroid rats. Plasma ANP was 102 +/- 5 pg/ml in euthyroid rats, 82 +/- 4 pg/ml in hypothyroid rats, and 138 +/- 11 pg/ml in hyperthyroid rats. We have also measured immunoreactive ANP in the atria of euthyroid, hypothyroid, and hyperthyroid rats. ANP content and concentration in the atria were lower (546 +/- 32 pg/mg tissue) in hyperthyroid rats than in hypothyroid rats (802 +/- 74 pg/mg tissue). Right atrium from euthyroid, hypothyroid, and hyperthyroid rats was superfused with a modified Langendorff preparation. Spontaneous release of ANP was significantly higher from the hyperthyroid rats (20 +/- 2 pg.min-1.mg-1) than from the hypothyroid rats (5.6 +/- 0.5 pg.min-1.mg-1). ANP release from the euthyroid rats was 9.3 +/- 1.2 pg.min-1.mg-1. These results indicate hyperthyroidism causes an increase in ANP secretion and a decreased release occurs during hypothyroidism.

Animals↗
PubMed1989

[Cerebrospinal fluid rhinorrhea].

Twenty-three cases of cerebrospinal rhinorrhea were reported. Seventeen were traumatic. Fistulae were mostly located in the ethmoid plate and the roof of the ethmoid sinus. Seventeen were treated by operation with 8 receiving more than two operations. The results were analysed and the diagnosis and treatment of the rhinorrhea discussed.

Adolescent↗
PubMed1988

Acid-induced esophagitis in cats is prevented by sucralfate but not synthetic prostaglandin E.

The cytoprotective effects of liquid sucralfate and a synthetic analog of prostaglandin E1 (PGE1) on acid-induced esophagitis in cats were studied. Esophagitis was induced in adult cats using a constant infusion of 0.1 N HCl at 1 ml/min for 20 min. Animals were infused for either one or three days. Mucosal lesions were evaluated by blinded investigators using both fiberoptic endoscopy and light microscopy. Histologic changes included basal cell hyperplasia, intraepithelial leukocytosis, and subepithelial leukocytosis. Liquid sucralfate given prior to acid infusion consistently prevented acid-induced lesions in both one- and three-day infusions, demonstrated by both endoscopy and quantitative histologic scoring. Indomethacin (200 micrograms/kg) given prior to sucralfate and acid did not affect sucralfate cytoprotection. Synthetic PGE1, given in doses of 5 micrograms/kg and 100 micrograms/kg, afforded no esophageal cytoprotection. These studies indicate that sucralfate is cytoprotective against acid-induced esophageal injury in cats, an effect that does not appear to be mediated by prostaglandin. In addition, synthetic PGE1 does not confer protection in this animal model.

Animals↗
PubMed1988

Regression of intracerebral lesions in T prolymphocytic leukaemia treated with intravenous deoxycoformycin.

A case of T-prolymphocytic leukaemia (T-PLL) presenting with deafness and confusion is reported. Computerised tomography (CT) of the head showed several well-defined, rounded, high attenuation areas in the temporal, parietal and occipital regions of the brain substance that were suggestive of metastases. Treatment with weekly intravenous deoxycoformycin produced complete resolution of the CT abnormalities together with haematological evidence of disease regression 6 weeks after treatment was started.

Antineoplastic Agents↗
PubMed1987

Acute unilateral pulmonary nonventilation due to mucous plugs.

Acute bronchial obstruction by mucous plugs may be manifested clinically by dyspnea, hypoxemia, and respiratory alkalosis mimicking pulmonary thromboembolism. In eight cases with complete interruption of ventilation to an entire lung, chest radiography failed to reveal the extent of the obstruction. Perfusion was substantially less affected than ventilation. Routine ventilation-perfusion scintigraphy with technetium-99m DTPA aerosol aids in the diagnosis of acute major bronchial obstruction in patients with suspected pulmonary thromboembolism.

Acute Disease↗
PubMed1986

Comparative discriminative stimulus properties of dl-cathinone, d-amphetamine, and cocaine in rats.

The discriminative stimulus properties of dl-cathinone (dl-CAT), d-amphetamine (d-A), and cocaine (COC) were compared and effects of haloperidol pretreatment on these properties were studied in rats. The ED50's of each drug were also determined. Stimulus generalization (i.e., greater than 75% of responses occurring on the drug lever) occurred with each of the three training drugs to all three test drugs. The degree of generalization was less between d-amphetamine and dl-cathinone than between d-amphetamine and cocaine or between cocaine and dl-cathinone. No significant differences were observed among the ED50's of each test drug obtained in all three training groups. Pretreatment with haloperidol failed to alter the stimulus properties of dl-cathinone. Haloperidol administration did partially antagonize the stimulus complex induced by d-amphetamine and cocaine. It is concluded that all three agents share somewhat similar but not identical, stimulus properties. The stimulus properties of the training dose of d-amphetamine may be somewhat different from those of dl-cathinone and may be more dependent on functional dopaminergic pathways.

Alkaloids↗
PubMed1986

Unusual radiologic presentations of bronchioloalveolar carcinoma.

Bronchioloalveolar carcinoma appears with variable radiologic features. The usual findings include a single nodule, multiple nodules, or areas of consolidation in lung. An air bronchogram in an area of nodular or mass-like density is also a well-known feature. We here report six patients whose disease illustrates interesting or unusual aspects of this neoplasm. The findings include: Minimal radiological signs despite diffuse disease found on CT scan or at surgery (two patients). Thickening of the wall of a preexisting lung cavity: presumed bronchogenic cyst. Expansile lobar consolidation without an air bronchogram simulating pleural disease. An elongated lobulated area of mass-like density resembling mucoid impaction. Homogeneous lobar atelectasis without an air bronchogram. Consideration of these varied features may aid in the radiological diagnosis of bronchioloalveolar carcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1984

The effects of dl-cathinone, d-amphetamine and cocaine on avoidance responding in rats and their interactions with haloperidol and methysergide.

The effects of dl-cathinone (dl-CAT), d-amphetamine (d-A), and cocaine (COC) on conditioned shock avoidance responding and their interactions with haloperidol and methysergide on this behavior were studied in male Wistar rats. All three stimulants produced significant increases in intertrial interval (ITI) responding and in the number of avoidance responses and a decrease in avoidance latencies. These actions were antagonized by pretreatment with haloperidol (0.07 and 0.15 mg/kg, IP). Pretreatment with methysergide (1.0 and 2.0 mg/kg, IP) increased the effects of all three stimulants on ITI responding, but not on the other two parameters. These results suggest that the effects of these stimulants on avoidance responding may be mediated by dopaminergic systems. In addition, these stimulant-induced changes on ITI responding probably also involve actions on serotonergic systems.

Alkaloids↗
PubMed1981

[A 5 consecutive day combination of CIS platinum and bleomycin in squamous cell bronchial carcinoma (author's transl)].

Twenty patients with inoperable squamous cell carcinoma of the lung (14 previously untreated and 6 previously treated) received a combination of bleomycin and cis-platinum for 6 consecutive days every 3 or 4 weeks. Pulmonary toxicity was minimal with only one case of reversible bleomycin-induced acute interstitial pneumopathy. The response rate was 65 p.cent. Thirteen patients had an objective response, including 5 apparently complete regressions. All responders were previously untreated patients. The results are discussed in the light of pharmacokinetic and cell kinetic data, and lead to a proposal for a non-conventional combined approach in squamous cell carcinoma of the lung, hitherto relatively unresponsive to chemotherapy.

Adult↗