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Biomedical subjects

J N Wang

Publications and source records attributed to J N Wang.

At least 37 records · Page 2Linked to original sources

Tricuspid atresia with persistent truncus arteriosus.

The association of tricuspid atresia and persistent truncus arteriosus is a very rare congenital anomaly. We report a newborn with a prenatal diagnosis of tricuspid atresia, in whom associated type II persistent truncus arteriosus was found by postnatal echocardiography. The patient had mild cyanosis and developed heart failure soon after birth. Balloon septostomy was performed to enlarge the interatrial communication. However, her condition rapidly deteriorated and she died of sepsis and heart failure at the age of 14 days.

Female↗

A study of the referral patterns of obstetric clinics and the performance of receiving neonatal intensive care units in Taiwan.

To study the referral patterns of obstetric clinics, and the performance of receiving intensive care units measured by the survival of transported neonates, transport records were collected prospectively between July, 1991 and June, 1992. Two hundred and fifty-four transported neonates born in 51 obstetric clinics (level I units) in Tainan City and County, in southern Taiwan, were enrolled in this study. Nineteen percent of the transported neonates were very low birthweight infants (< 1500 g). Nearly equal numbers of them were transported to eight district hospitals (level II units) and to a tertiary center (level III unit), but these infants were 1.5 times more likely to die in a level II unit than a level III unit. In addition, equal numbers of infants assisted by mechanical ventilators were transported to level II and III units, but these infants were three times more likely to die in a level II unit than a level III unit (P = 0.006). Seventy-seven percent of the normal birthweight infants (> or = 2500 g) were transported to level II units, and the mortality in this group was 12.3% compared with 0% in those transported to the level III unit. Approximately 56% of these normal birthweight infants in level II units died of severe birth asphyxia. The referral patterns of level 1 units had an unfavorable effect on the survival of neonates requiring mechanical ventilation. Enhancing the skills of the staff in level I units to recognize and stabilize such infants, elevating the capability of level II units in treating some of these cases, and increasing the hospital beds for level III care are necessary to increase their chance of survival.

Health Services Research↗

Laryngeal candidiasis in children.

Candidiasis of the larynx is rare and often related to immunocompromised hosts. We here report a case of laryngeal candidiasis in an immunocompetent infant. The diagnosis was obtained by direct fibre-optic laryngoscopy with specimens submitted for culture. He received anti-fungal medication and was quite well at 1-year follow up. The pertinent literature is also reviewed.

Administration, Oral↗

Cantrell's syndrome in an infant.

Cantrell's syndrome is a rare combination of congenital midline thoracoabdominal defects and congenital heart disease. surgical repair can correct many of the anomalies. We report a neonate who presented with a short sternum, defective upper abdominal muscle, ectopic umbilicus, anterior diaphragmatic defect, ventricular septal defect and an intra-abdominal left ventricular diverticulum. Initially, the infant was treated with digoxin and diuretics for 5 months. Due to poor control of heart failure, one-stage surgical correction was performed with patch repair of the ventricular septal defect, ligation of left ventricular diverticulum and closure of the defects of the diaphragm and upper abdominal wall.

Abnormalities, Multiple↗

Trifascicular block with intermittent complete atrioventricular block in a child.

Trifascicular block, which consists of impaired conduction in the three main fascicles of the ventricular conduction system, may progress to high-grade or complete atrioventricular block. It rarely occurs in children with a structurally normal heart. We report a case of trifascicular block in a previously healthy 9-year-old girl. The patient presented with repetitive seizures. The electrocardiogram showed a complete right bundle branch block, left axis deviation, PR interval prolongation, and intermittent high-degree and complete atrioventricular block. She was successfully treated with a temporary pacemaker and her electrocardiogram returned to a normal sinus rhythm in 3 days. She has remained well over a 4-year follow-up. Although her cardiac enzyme levels were normal, the clinical course and electrocardiography findings suggested myocarditis. We emphasize the diagnosis of trifascicular block using electrocardiography; clinical outcome is good, if the patient is managed properly.

Child↗

Infantile hypertrophic pyloric stenosis after surgery for esophageal atresia with tracheoesophageal fistula.

Infants with esophageal atresia and tracheoesophageal fistula may have other associated anomalies. The development of infantile hypertrophic pyloric stenosis in the postoperative course of esophageal atresia with tracheoesophageal fistula is rarely reported. Because its symptoms may mimick postoperative complications such as gastroesophageal reflux or anastomotic stricture, the diagnosis may be delayed. We report an infant who had surgery for esophageal atresia with tracheoesophageal fistula at birth. The infant presented with nonbilious projectile vomiting at 4 weeks of age. Plain abdominal x-ray, barium upper gastrointestinal series and abdominal ultrasonography all supported the diagnosis of hypertrophic pyloric stenosis. The diagnosis was confirmed during surgery. After pyloromyotomy, the patient's condition improved.

Abnormalities, Multiple↗

Swertifrancheside, an HIV-reverse transcriptase inhibitor and the first flavone-xanthone dimer, from Swertia franchetiana.

The first flavone-xanthone C-glucoside, swertifrancheside, was isolated from Swertia franchetiana, and its structure was elucidated on the basis of spectroscopic analysis as 1,5,8-trihydroxy-3-methoxy-7-(5',7',3'',4''- tetrahydroxy-6'-C-beta-D-glucopyranosyl-4'-oxy-8'-flavyl)-xanthone . This compound was a moderately potent inhibitor of HIV reverse transcriptase.

Antimalarials↗

CO and particle pollution of indoor air in Beijing and its elemental analysis.

Three representative types of houses in Beijing were selected and, in each type, smoking and nonsmoking households were compared, IP, RP, and CO concentrations in the living room and kitchen were monitored during each season, and the level of COHb in the heads of the households were measured. The study showed that indoor air pollution was rather severe, especially during winter, when particulate concentrations markedly exceeded the standard and CO concentration was as high as 47 ppm. Indoor air pollution was closely related to the type of house, particularly to the mode of heating. In houses, of the same type, pollution improved greatly after central heating facilities were installed. Analysis of 30 elements revealed that pollution was typically caused by coal burning, aggravated by dusty wind, but high indoor Pb levels were probably due to the use of LPG for cooking. In our study the effect of cigarette smoking was sometimes masked by the severe indoor pollution.

Air Pollutants↗

Human exposure to carbon monoxide and inhalable particulate in Beijing, China.

Twenty nonsmoking volunteers were selected from the staff members of the Institute of Health according to their housing conditions. Carbon monoxide (CO) and particulate matter in the outdoor and indoor air and personal exposure were monitored simultaneously for 1 week in summer and 1 week in winter. At the same time some public areas, such as workplaces and shopping and traffic areas, were also monitored. The average outdoor concentration for CO was 1.5 ppm in summer and 3.9 ppm in winter; indoors it averaged 2.8 ppm in summer and 20.1 ppm in winter. Personal exposure fluctuated between these values. The level of COHb averaged 0.2% in summer and 1.9% in winter. The level of inhalable particles was higher in winter than in summer, but the difference was not as marked as that for CO. The activity diary showed that the time spent at home was around 66% and that total indoor (home and workplace) time was over 90%. This indicates the importance of studying indoor pollution and personal exposure.

Adult↗

An equilibrium between distorted and undistorted DNA in the adult chicken beta A-globin gene.

We have used single strand specific nucleases to map DNA distortion in the adult chicken beta A-globin gene. We have detected two structures of that kind and have mapped nuclease-cutting sites at one base resolution. One prominent site is centered at -190 relative to the RNA capping site and is positioned at the center of a stretch of contiguous C residues. The second site is near the first intron/exon junction (+620) and appears as a series of discrete 1-base-long enzyme-cutting sites. Based upon the pattern of nuclease cutting and the kinetics of nuclease cutting we conclude that the "poly(C)" stretch may assume a looped geometry in supertwisted DNA molecules which is similar to that proposed by Felsenfeld (Nickol, J. M., and Felsenfeld, G. (1983) Cell 35, 467-477). We show that S1 nuclease cuts within the intron occur mainly at the end points of polypurine segments and suggest that such end points may assume a distorted transitional geometry. We find that Neurospora crassa endonuclease cuts both the promotor and intron sites in linear DNA molecules but that in linear DNA the cutting process is limited by a first order conformation change of the DNA substrate. Based upon those kinetics we propose that in unstressed DNA, each of the two sites can convert between a distorted and undistorted geometry. In the enzyme assay buffer at 37 degrees C, the time constant for the equilibrium is nearly 10 h for the promotor site and 7 h for the intron.

Animals↗

The effect of female strain on identification of male mice carrying reciprocal translocations.

Chemicals capable of inducing heritable chromosomal effects may be detected by the mouse heritable translocation test, which is based on the detection of a specific type of transmissible abnormality, namely, reciprocal translocation. Since mice carrying such a chromosomal abnormality usually have reduced fertility, they may be identified on the basis of fertility data. In the present study, the efficiency of two female strains for identifying CD-1 male translocation heterozygotes was examined. Thirty-three 10-wk-old CD-1 male mice were injected IP with triethylenemelamine (0.025 mg/kg/day) 5 days a wk for 5 wk. The treated males were then mated to untreated CD-1 females for 2 wk to produce progeny. The F1 males were raised to maturity, tested for fertility by using two female strains (CD-1 and B6C3F1), and analyzed cytogenetically. The cytogenetic analysis confirmed that 41 males were translocation heterozygotes and 125 were normal. Examination of the fertility data showed that in the test with CD-1 females all translocation heterozygotes were identified but 19 normal mice were identified as potential translocation carriers because of decreased fertility. In the test with B6C3F1 females, five translocation heterozygotes were not identified on the basis of fertility data, and 11 normal mice were misclassified as potential translocation carriers.

Animals↗