Biomedical subjects

B Hwang

Publications and source records attributed to B Hwang.

At least 37 records · Page 2Linked to original sources

PubMed2000

Transcatheter closure of atrial septal defect with a CardioSEAL device.

Transcatheter closure of an interatrial septal defect (ASD) with a CardioSEAL device was successfully performed on 12 Taiwanese children. There were five boys and seven girls, aged from 3.6-13.9 (8.3+/-3.2) years and with body weight of 15-57 (33.7+/-14.7) kgs. After one year of follow-up studies, which included physical examination, ECG, chest X-ray and echocardiography, complete closure of ASD was achieved in nine (75%) patients. Two children with a trivial residual shunt were asymptomatic and without audible cardiac murmur. A girl had a small residual left to right atrial shunt by color Doppler echocardiography, but without audible cardiac murmur. There were no immediate or intermediate complications. Transcatheter implantation of the CardioSEAL device is a safe and proper treatment for children with non-complicated small to medium secundum ASD.

Adolescent↗

PubMed2000

Crude protein content and amino acid composition in Taiwanese human milk.

Breast milk provides the essential nutrients for infants in readily available form. The content of nitrogen in human milk is of great importance because it relates to the growth of infants in the early stage, and the composition of nitrogenated compounds varies according to the lactational stage. Three-hundred-and-three human milk specimens were obtained from 240 healthy mothers living in two different districts in Taiwan, and 264 specimens were used for the analysis. The crude protein content, total and free amino acid compositions as well as urea content were evaluated using pooled milk samples according to different lactational stages and geographical location. The crude protein content decreased sharply from colostrum (2.51 g/100 mL) to mature milk (1.25 g/100 mL). Total amino acids account for 80-85% of the crude protein throughout the whole lactation period. Crude protein also contained 30 to 35 mg/ 100 mL urea and 41 to 48 mg/ 100 mL free amino acids as non-protein nitrogen components. The ratio of essential to non-essential amino acids remained constant throughout the lactation period in spite of a decline in amino acid content. The amino acid composition per 1 g of nitrogen varied during the lactation period. The differences of these lactational changing patterns of individual amino acids were probably reflected by variation of the protein composition during lactation. The sum of free amino acid content ranged from 43 to 50 mg/100 mL in Taipei and 40 to 45 mg/100 ml, in Kaohsiung. Although the variations of free amino acids during the lactation period differed among amino acids, glutamic acid predominated in mature milk while phosphoethanolamine was predominant in colostrum.

Adult↗

PubMed2000

The assessment of anaerobic blood culture in children.

Over the past 20 years, there has been a decline in the percentage of positive blood cultures yielding anaerobic organisms. Due to the limited blood volume drawn from pediatric patients, we have assessed the value of routine anaerobic blood cultures in children. From January 1994 to December 1998, 9886 paired aerobic and anaerobic blood cultures were analyzed in the pediatric microbiology laboratory at the Taipei Veterans General Hospital. Six hundred and eighteen (6.25%) isolates were considered to be clinically important microorganisms. Staphylococci, streptococci, aerobic gram-negative bacilli, and yeasts showed more significant growth within the aerobic culture than that within the anaerobic culture. Significantly more aerobic gram-positive cocci, aerobic gram-negative bacilli, and yeasts were detected at least 1 day earlier by using the aerobic culture. Three patients with documented anaerobic bacteremia had obvious symptoms related to anaerobic infections. Our study concludes that routine use of anaerobic blood culture in pediatric patients is not necessary. Anaerobic blood cultures should be reserved for patients with diseases like intra-abdominal or oral infections, neutropenic patients on steroid therapy, pressure sores, cellulitis, and human bite wounds.

Bacteremia↗

PubMed2000

Toxic megacolon secondary to infective colitis in children.

BACKGROUND AND PURPOSE: Toxic megacolon is a fulminating and potentially lethal complication of severe colitis. Toxic megacolon secondary to infective colitis in children is rare. We analyzed the clinical course, pathology, treatment, and outcome of toxic megacolon secondary to infective colitis in children. METHODS: The medical records of all 20 children treated for infective colitis complicated with toxic megacolon during a 12-month (October 1997-October 1998) period were retrospectively reviewed. RESULTS: There were 10 boys and 10 girls, with a mean (+/- standard deviation, SD) age of 26.2 +/- 12.9 months (range, 6-57 mo). With an initial presentation of nonspecific gastroenteritis syndrome lasting several days, the disease progressed rapidly. In the acute stage, most patients developed toxic signs such as mental change, ranging from irritability to stupor (20, 100%), fever (19, 95%), tachycardia (20, 100%), abdominal distension (20, 100%), and abnormal stool pattern (19, 95%). Initial investigations revealed anemia (11, 55%), leukocytosis (11, 55%), and elevated levels of C-reactive protein ranging from 25.0 mg/L to 483.0 mg/L with a mean +/- SD of 185.7 +/- 129.1 mg/L (normal range, < 8 mg/L) (20, 100%). Salmonella enteritidis (12 patients, 60%) and Clostridium difficile (1, 5%) were isolated from stool samples in some cases. Plain abdominal x-rays revealed severe colonic dilatation. Prolonged hospitalization (mean, 33.6 d) and intensive therapy including a combination of broad-spectrum antibiotics, physical decompression, and total parenteral nutrition were necessary. Three patients (15%) underwent surgical management; the pathologic findings in these patients demonstrated severe transmural inflammation. We believe that bacterial and/or endotoxin translocation played an important role in gut failure. Three patients (15%) in the study died. CONCLUSION: Toxic megacolon in infective colitis is a fulminating illness that has a high mortality rate. The disease course can be divided into three stages: the acute toxic stage, the gut failure stage, and the convalescence or deterioration stage. Early diagnosis and aggressive management are important.

Bacterial Infections↗

PubMed2000

Cytomegalovirus pericarditis with cardiac tamponade in a young infant.

The principal viruses implicated in pericarditis are enteroviruses. Cytomegalovirus pericarditis is quite rare and has been reported in immunocompromised patients with acquired immunodeficiency syndrome, malignant neoplasm or organ transplantation. We report a three-month-old male infant who suffered from cough and rhinorrhea for two weeks. He developed shortness of breath for three days, and fever for one day, prior to admission. Physical examination revealed tachycardia, tachypnea, pale conjunctiva, hepatomegaly, and a muffled heart sound without significant murmur. Chest radiography showed marked enlargement of the cardiac silhouette. Echocardiography demonstrated a large amount of pericardial effusion with impaired diastolic ventricular function. After pericardial drainage and supportive treatment, the fluid gradually disappeared. Viral culture of the pericardial fluid and serologic data confirmed a cytomegalovirus infection. Cytomegalovirus pericarditis should be included in the differential diagnosis of pericardial effusion in a young infant.

Cardiac Tamponade↗

PubMed2000

Cardiac manifestations of fatal enterovirus infection during the 1998 outbreak in Taiwan.

BACKGROUND: An outbreak of hand-foot-and-mouth disease caused by enterovirus infection occurred in Taiwan in 1998 and more than 70 infants and children with fulminant courses died. We compared the cardiac manifestations of fatal cases with patients who survived the enterovirus infection. METHODS: A total 187 patients with enterovirus infection were treated at Taichung Veterans General Hospital between April and June 1998. Enterovirus infection was diagnosed by history, clinical features, polymerase chain reaction study and/or viral culture. Cardiac examinations including complete physical examinations, electrocardiography and echocardiography were performed on seven cases (group I) with or without central nervous system (CNS) involvement, 30 patients with CNS involvement (group II), and 150 patients without CNS involvement (group III). RESULTS: There were no significant differences in sex distribution, days of fever, heart rate, systemic blood pressure or time from the onset of symptoms to hospital admission among the three groups. All group I patients had features of acute congestive heart failure, pulmonary edema and neurologic signs except one who presented with right-sided heart failure and neurologic signs. The echocardiographic findings of group I were a lower fractional shortening, lower ejection fraction, and more severe and higher incidence of mitral regurgitation (p < 0.01) than in groups II and III, but there were no significant differences in end-systolic wall stress, left ventricular end-diastolic internal dimension and incidence of pericardial effusion among the three groups. CONCLUSIONS: We conclude that seven infants and children (group I) died due to either severe cardiomyopathy or encephalopathy. The possible pathogenesis of enterovirus infection leading to death is reviewed and analyzed.

Brain Diseases↗

PubMed2000

Intratracheal oxygen administration during bronchoscopy in newborns: comparison between two different weight groups of infants.

BACKGROUND: The development of ultrathin fiberoptic bronchoscopy (FB) has made the examination of neonatal airways a practical possibility. The aim of this study was to assess the effects of intratracheal oxygen (ITO) administration on blood oxygenation and carbon dioxide (CO2) changes during FB in different body-weight infants. METHODS: Newborns suspected of having airway problems, but in a stable cardiopulmonary condition were studied. An ultrathin (outside diameter, 2.2 mm) fiberoptic bronchoscope that was modified by adding an external tube (internal diameter, 0.3 mm; outside diameter, 0.64 mm) to deliver oxygen was used. For ITO administration, a low oxygen flow rate of 0.1 l/kg/min was delivered directly into the trachea. Oxygenation and CO2 measurements were obtained at five different stages: 1) just before FB (baseline); 2) with the tip of the bronchoscope at the supralarynx; 3) with the tip at the carina without ITO; 4) with the tip at the carina with ITO; and 5) 15 minutes after FB. Forty infants were studied completely and divided into two groups according to their body weight: 1) the light-weight group (< 2,500 g), 21 infants; and 2) the heavy-weight group (> or = 2,500 g), 19 infants. RESULTS: In both groups, arterial blood oxyhemoglobin saturation and oxygen tension decreased significantly (p < 0.05) when the tip of the bronchoscope advanced from the nostril to the supralarynx, and further decreased (p < 0.01) when at the carina level. Small infants had greater decrements of both oxygenation measurements (p < 0.05) than the large infants. After ITO administration, both oxygenation measurements increased significantly (p < 0.001) and returned to baseline following FB. Both end tidal pressure of CO2 (P(ET)CO2) and arterial CO2 tension (PaCO2) significantly increased from the baseline when the FB tip was advanced from the supralarynx to the carina (p < 0.05). During ITO administration, the PaCO2 increased (p < 0.01) but the P(ET)CO2 decreased (p < 0.001). After FB, both CO2 measurements returned to baseline. The pH only decreased during ITO administration. CONCLUSIONS: We conclude that FB causes significant hypoxemia and hypercapnia in newborns, especially in underweight infants. Appropriate ITO can be considered a safe and beneficial technique for maintaining oxygenation during FB. P(ET)CO2 monitoring may mask true blood CO2 retention during ITO administration.

Birth Weight↗

PubMed2000

Influence of ventricular septal defect type on surgical results in children with tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF) with subpulmonary ventricular septal defects (VSD) is relatively more common among Orientals than among Occidentals. This study assessed the influence of type of VSD on surgical results in children with TOF. METHODS: Fifty-one patients with TOF (age range, 14 months to 11 years, mean 40.7 months, median 30 months, 29 boys, 22 girls) who underwent total correction by a single surgeon between January 1992 and December 1995 were retrospectively studied. Of the 51 patients, 17 patients with subpulmonary VSD were classified as group I. The remaining 34 patients with perimembranous VSD were classified as group II. All patients underwent a combined transatrial and transpulmonary surgical approach. Early postoperative results were evaluated 7 to 10 days after surgery and late postoperative results were evaluated 1 year after surgery. RESULTS: There were no statistically significant differences between the two groups in age, sex, body weight, pulmonary to systemic flow ratio, pulmonary to aortic annulus diameter ratio or preceding palliative shunt or balloon pulmonary valvuloplasty. Nevertheless, group I patients had better oxygen saturation preoperatively (84.2 +/- 4.4% vs 80.3 +/- 7.6%, p = 0.037). During surgery, the transannular patch rate was higher in group I (100% vs 73.5%, p = 0.003). The cardiopulmonary bypass time, postoperative stay in the intensive care unit, duration of chest tube placement, early postoperative residual VSD rate, and early and late postoperative residual pulmonary stenosis rate were not significantly different between the groups. However, late postoperative residual VSD rate was 33.3% in group I and 6.45% in group II, which was statistically significant (p = 0.029). There were no significant differences in arrhythmia between the two groups. CONCLUSIONS: Patients with TOF with subpulmonary VSD had a better preoperative oxygenation, higher transannular patch rate during surgery and a higher incidence of late residual VSD than those with TOF with perimembranous VSD.

Cardiac Surgical Procedures↗

PubMed1999

Congenital hypothyroidism with multiple ovarian cysts.

UNLABELLED: A case of ectopic thyroid with congenital hypothyroidism presenting with bilateral multicystic ovaries without marked precocious puberty is reported. The cystic ovaries disappeared dramatically after thyroid hormone therapy. CONCLUSION: When ovarian cysts are found in prepubescent females, the possibility of associated hypothyroidism should be considered.

Age Determination by Skeleton↗

PubMed1999

Social interactions of high school students with mental retardation and their general education peers.

The informal social interaction behavior that is typical of a high school lunchroom in which general and special education students are physically included was described. Using systematic observation and social comparison methods, we compared the performance of two groups of students (12 general education students and 12 students with mental retardation). Both similarities and differences were found in the interactions of students with mental retardation and their general education peers with respect to social behaviors, conversational topics, and context within which interactions occurred. However, despite being in proximity, students with mental retardation rarely interacted with any of approximately 500 general education students present in the lunchroom. Implications are discussed for increasing social interaction among high school students.

Adolescent↗

PubMed1999

Prevalence and parental origin in Tetralogy of Fallot associated with chromosome 22q11 microdeletion.

OBJECTIVE: Tetralogy of Fallot is a common cardiac anomaly that is associated with chromosome 22q11 microdeletion. In this study we examined the mode of transmission as well as the parental origin of microdeletion in patients with tetralogy of Fallot. METHODS: Eighty-four children with sporadic tetralogy of Fallot (40 boys and 44 girls; mean age, 34 months) were analyzed for microdeletion at chromosome 22q11 by genotype analysis, using five microsatellite markers, D22S427, D22S941, D22S944, D22S264 and D22S311, and confirmed by quantitative polymerase chain reaction, using TUPLE1 and D22S264. All parents of these subjects consented to their own participation and their child's participation in the clinical evaluation and molecular study. To provide a molecular characterization of microdeletion, we isolated DNA from the parents and typed their DNA with each of the five polymorphic markers. RESULTS: Sixty-six patients were associated with pulmonary stenosis; and 8 of these cases (12%) had microdeletion. Eighteen patients were associated with pulmonary atresia, and 6 (33%) of these cases had microdeletion. The parental origins of the 14 patients with microdeletion were paternal in 3 cases and maternal in 11 cases. The most common mode of transmission was de novo without parental hemizygosity (93%). Transmission by autosomal dominant heredity was uncommon (7%). CONCLUSIONS: Biased parental origin was consistently found in tetralogy of Fallot patients with chromosomal 22q11 microdeletion. Our results indicated a higher prevalence of microdeletion because of inheritance of maternal microdeletion (78%).

Abnormalities, Multiple↗

PubMed1999

Treatment of pulmonary atresia with intact ventricular septum in early infancy.

BACKGROUND: Early treatment for the neonate with pulmonary atresia and intact ventricular septum (PA-IVS) is important if a high mortality rate is to be avoided. The treatment includes prostaglandin administration, balloon atrial septostomy, pulmonary valvotomy, a shunting procedure and patch repair for the right ventricular outflow tract (RVOT). This study discusses the early treatment and risk factors of this disease that are essential for assessing the risk of surgery and predicting outcome. METHODS: The medical records, echocardiograms, catheterization data and cineangiograms of 29 patients with PA-IVS diagnosed at our institution from 1987 to 1997 were reviewed retrospectively. Clinical manifestations including age, body weight, sex ratio, type of surgery and outcome were analyzed. RESULTS: Three of four patients with a right ventricular volume of less than 1 ml died, and all patients with a right ventricular volume of greater than 2 ml survived. Four of six patients with a tricuspid valvular area of between 0.25 and 0.5 cm2 died, but patients with an area of greater than 0.5 cm2 survived. One case with a monopartite right ventricle died. Patients with a bipartite or tripartite right ventricle had higher survival rates than those with a monopartite right ventricle. Patients with a the right ventricle dependent coronary sinusoid had a higher risk for mortality, even after surgery, than those with normal coronary circulation. CONCLUSIONS: A small right ventricular volume, the presence of a coronary sinusoid involving the right ventricle, a short linear length of the tricuspid valve and a small area of the tricuspid valve were the risk factors associated with a negative outcome in neonates with PA-IVS.

Female↗

PubMed1999

Hemodynamic and neurohumoral changes after abdominal aortic constriction in rats.

Cardiac after-load, neurohumoral reaction and the secondary cardiac hypertrophy were studied in six groups of Sprague-Dawley (SD) rats with abdominal aortic constriction. We found that abdominal aortic constriction above the renal arteries decreased the heart rate and cardiac output, and increased the pulse pressure. These abnormalities would return to normal after constriction ended. Captopril, propranolol and prazosin could reduce the increase of pulse pressure but still had decreased in cardiac output of rats with abdominal constriction. Aortic constriction also increased the aortic impedance and cardiac load but decreased aortic compliance. These changes could also be lessened by captopril, propranolol and prazosin. We have confirmed that aortic constriction can induce secondary cardiac hypertrophy, but the pathogenesis might be due to multiple factors.

Animals↗

PubMed1999

Percutaneous transluminal coronary angioplasty for renovascular hypertension in a child: a case report.

Since its introduction, percutaneous transluminal coronary angioplasty has become an alternative therapeutic modality to surgical and medical treatment for renovascular hypertension. We report the case of a nine-year-old boy who had hypertension caused by renal arterial stenosis. The patient's high blood pressure was 164/100 mmHg, which was discovered incidentally during a physical check-up. A selective renal angiography showed a severe short-segment stenosis with post-stenotic dilatation of the left renal artery. A 4-mm balloon catheter was advanced through the stenotic area and was inflated five times to dilate the stenosis. After the procedure, the selective renal angiography showed a significant increase in the diameter of the left renal artery. Blood pressure decreased to normal immediately after the procedure. During the one-year follow-up period, the patient remained normotensive without the use of antihypertensive drugs.

Angioplasty, Balloon, Coronary↗

PubMed1999

High-frequency oscillatory ventilation in premature infants.

BACKGROUND: Although assisted ventilation has reduced the mortality rate of premature infants, pulmonary disease is still the major cause of morbidity and mortality in very low birth weight infants. We designed this study to evaluate the efficacy and safety of high-frequency oscillatory ventilation (HFOV) in premature infants and to compare the outcome for early intervention with HFOV versus conventional ventilation (CV). METHODS: From January, 1997, to June, 1998, we analyzed premature infants with respiratory failure who required mechanical ventilation and supplemental oxygen to support adequate gas exchange in our neonatal intensive care unit. Patients were eligible if their gestational age was less than 35 weeks or their birth weight was less than 1,751 g. A total of 35 neonates were enrolled in the study. Eighteen infants were treated with HFOV, and 17 infants were treated with CV. They were treated with early intervention of HFOV or CV, within 24 hours-of-age. Patients were excluded if a lethal congenital anomaly, bacteremia, hydrops fetalis, congenital diaphragmatic hernia or intubation only for apnea were noted. Data on demographics, gas exchange and outcome parameters were collected for each patient enrolled in the study. RESULTS: No differences were noted in the demographic features between the study groups. All of the enrolled patients suffered from variable grades of respiratory distress syndrome. A significantly shorter intubation period was found in the HFOV group compared with the CV group (2.8 +/- 1.5 days vs 8.8 +/- 9.4 days; p = 0.013). CONCLUSIONS: HFOV is a safe and effective therapy for premature infants with respiratory failure due to respiratory distress syndrome.

Female↗

PubMed1998

Cloning of genes specifically expressed in rice embryogenic cells.

We have examined differences in gene expression pattern between embryogenic callus (EC) and nonembryogenic callus (NEC) derived from mature seed embryo of rice (Oryza sativa L. cv Donggin). Three EC-specific transcripts were identified by differential display of amplified cDNAs. Specific expression of two partial cDNAs, designated as REC1 and REC2, respectively, was confirmed by a northern blot analysis. Partial nucleotide sequence of the clone REC1 showed no homology with any known genes, but partial amino acid sequence deduced from the clone REC2 exhibited 55-82% homology with nickel-cobalt-resistant proteins identified from a bacterium, Alcaligenes eutrophus CH34.

Amino Acid Sequence↗

PubMed1998

Metabolic detriment in donor heart valves induced by ischemia and cryopreservation.

BACKGROUND: The injury resulting from postmortem ischemia is a critical deterrent to the availability of donor valves. Using the reduction of XTT-tetrazolium salt as a marker of metabolic sequelae, we assessed the injurious effect of ischemia and the metabolic sequelae in 156 porcine semilunar leaflets. METHODS: The leaflets were randomly allocated to noncryoprocessed (n = 72) or cryoprocessed (n = 72) groups. At each preservation temperature of 4 degrees C, 24 degrees C, or 37 degrees C, 24 leaflets each were exposed to one of four storage periods of 9, 17, 30, or 60 hours. Twelve fresh aortic leaflets served as baseline reference samples. RESULTS: There was a progressive loss in the metabolic functioning of valve leaflet cells in both noncryopreserved and cryopreserved tissue as the storage times increased. Cryopreserved tissue showed a greater loss of function than noncryopreserved tissue did. The metabolic injury was mainly a consequence of cryoprocessing. The greatest loss in metabolic functioning occurred in the valves stored for 60 hours. The least favorable combination of variables was cryopreservation and a precryopreservation storage time of 60 hours. CONCLUSIONS: We conclude that 30- to 60-hour delays do not have a significant metabolic effect on cardiac leaflets. Thus it may be possible to safely extend the permissible ischemic periods after organ harvest.

Animals↗

PubMed1998

Heparinization on pericardial substitutes can reduce adhesion and epicardial inflammation in the dog.

OBJECTIVE: Primary concerns about currently available pericardial substitutes include adhesion and epicardial reaction. The purpose of this study is to evaluate host reaction to pericardial substitutes with and without incorporating slow heparin release. METHODS: To avoid biologic variation among these pericardial patches, we made a composite of six membranes. The composite membrane consisted of epoxy-fixed patches with (1) or without (2) ionically bound heparin, a glutaraldehyde-fixed patch with (3) or without (4) ionically bound heparin, an expanded polytetrafluoroethylene patch (5), and a polyester polymeric patch (6). Ten recipient dogs weighing from 12 to 19 kg (mean 13.6 kg) were used to assess the composite membranes as pericardial substitutes. The implanted composite membranes were retrieved 1 week (one dog), 2 weeks (one dog), 4 weeks (one dog), 8 weeks (one dog), and 12 weeks (six dogs) after implantation. RESULTS: Overall, the synthetic patches had a more notable inflammatory reaction than the biologic patches with or without ionically bound heparin. The heparin-bound patches caused significantly less inflammation than their nonheparinized counterparts. The heparinized porcine patches cross-linked with different compounds were found to have less fibrous formation than the nonheparinized patches and the synthetic patches. CONCLUSIONS: Heparinized pericardial substitutes may cause less adhesion and inflammatory reaction than nonheparinized material.

Animals↗