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Biomedical subjects

M H Chang

Publications and source records attributed to M H Chang.

At least 181 records · Page 10Linked to original sources
PubMed1989

Factors affecting clearance of hepatitis B e antigen in hepatitis B surface antigen carrier children.

To understand the natural history of chronic hepatitis B virus infection in children, we studied factors affecting the clearance of hepatitis B e antigen (HBeAg). One hundred sixty-nine apparently healthy children whose sera were positive for HBeAg and hepatitis B surface antigen (HBsAg) and who were recruited by screening were followed prospectively to delineate the HBeAg clearance rate. Another 59 carrier children visiting the outpatient clinic because of symptoms or abnormal liver function were studied for comparison. The annual HBeAg clearance rate was low (less than 2%) during the first 3 years of life but increased with age. The HBeAg clearance rate in children older than 6 years of age was lower in those whose mothers had HBsAg positivity (14.3%) than in those whose mothers had no detectable HBsAg (35.3%). Children who were brought for medical care had higher HBeAg clearance rates (42.4%) than those who were recruited by screening (14.6%) because immune clearance of hepatitis B virus and hence HBeAg often led to hepatocellular damage manifested by abnormal liver function profiles or by symptoms that had caused the parents to seek medical care for their children. We conclude that age, source of subject recruitment, and maternal HBsAg status are important factors affecting HBeAg clearance rate in HBsAg carriers.

Adolescent↗
PubMed1989

Serum alpha-fetoprotein levels in normal infants: a reappraisal of regression analysis and sex difference.

Age-dependent changes of serum alpha-fetoprotein (AFP) levels were analyzed in 284 normal infants, including 113 full-term neonates and 171 infants between 1-12 months old. Serial statistical analyses attempted to clarify some confusing and conflicting observations presently existing in the literature. The results showed the following: (a) variations of AFP values were homogeneous throughout infancy, after the logarithmic transformation that is essential in dealing with AFP data. (b) To obtain an approximately 95% prediction band of normal AFP levels in infancy, the regression analysis should be based on the power regression rather than the exponential progression model: log Y = 7.397 - 2.622.log (X + 10), where X = age in days and Y = AFP level in nanograms per milliliter. (c) A sex-related difference existed with higher mean values for male babies between 2-4 days of age, a fact that may be missed with casual analysis. In addition, the mean AFP level was found to be relatively constant at some time during the 1st week of life, in contrast to its subsequent extremely rapid decline. These characteristic changes deserve further investigation.

Female↗
PubMed1989

Chronic duodenal ulcer in children: clinical observation and response to treatment.

Chronic duodenal ulcer is diagnosed more frequently in children since recent advances in panendoscopy techniques. From 1976 to 1986, chronic duodenal ulcer was diagnosed in 33 children in this hospital. There was a marked male preponderance (male: female = 4.5:1). Family history for peptic ulcer was positive in 36% of the patients. The important element of emotional stress was identified in 39% of the patients. Thirty patients received medical treatment, and 26 were observed for more than 1 year (1-10 years). In 11 children, medication was changed because of symptom recurrence and change in the mode of treatment. The patients were divided into three groups with different treatment regimens: antacid (12 cases), cytoprotective agent (sucralfate, 17 cases), and histamine H2-receptor antagonist (cimetidine, eight cases). The response to short-term (eight-week) therapy was similarly good (83-94%) in the three treatment groups. However, sucralfate is superior to antacid in the ongoing maintenance therapy of chronic duodenal ulcer in childhood. Because chronic duodenal ulcer recurred frequently, it is crucial to give long-term maintenance therapy.

Adolescent↗
PubMed1989

Acute duodenal ulcer.

A series of 31 infants and children with acute duodenal ulcer verified by endoscopy was studied over an eight year period. Eighteen (58%) of them were under 2 years of age. The most common symptom was upper gastrointestinal bleeding (n = 27, 87%). Twenty nine patients (94%) had a preceding illness characterised by diarrhoea, upper respiratory tract infection, or fever, which was not necessarily treated with antipyretic drugs. Initial endoscopy showed that ulcer lesions were solitary in 14 patients and present on the anterior wall (n = 11), posterior wall (n = 2), or both (n = 1). Multiple ulcers were found in 17 patients, and present in the bulb with (n = 6) or without (n = 11) extension into the second part of duodenum. The most conspicuous finding was the irregularly shaped ulcers seen in eight young children with similar clinical and endoscopic features. Sixteen patients were re-endoscoped one to two weeks after the initial examination; the ulcers had entirely disappeared in 13, and there were only small residual ulcers in three. Thirty patients were treated medically and only one (with uncontrollable haemorrhage) required operation. Most patients were symptom free two to six years after the initial diagnosis. Our results suggest that young children may develop acute duodenal ulcers after viral illnesses whether or not they are treated with drugs, mainly antipyretics. This kind of acute duodenal ulcer usually heals quickly irrespective of the morphology, site, and number of ulcers.

Acute Disease↗
PubMed1989

Extrahepatic biliary obstruction caused by cancer of non-liver origin in children: report of 5 cases.

Obstructive jaundice secondary to external compression of the extrahepatic bile duct caused by tumor of non-liver origin was found in 5 of 199 consecutive children with cancer between 1986 and 1988 at the Department of Pediatrics, National Taiwan University Hospital. Of the 5 patients, 2 had non-Hodgkin's lymphoma and the other 3 had acute promyelocytic leukemia, histiocytosis X and neuroblastoma, respectively. Extrahepatic biliary obstruction occurred as part of the initial presentation of malignancy in 3 cases, and later in the course of disease in the other 2 cases. In each instance, abdominal ultrasonography and computed tomography revealed dilatation of intrahepatic biliary trees due to mass compressing effects. A huge multilobulated tumor and multiple enlarged lymph nodes near the porta hepatis were found in all 3 patients who underwent an exploratory laparotomy. Wedge biopsy of the liver showed no cancer cell invasion. One case died before chemotherapy had commenced. The other 4 patients received chemotherapy and 3 of them received additional radiotherapy. Although jaundice and tumor regressed dramatically with this mode of treatments, subsequent recurrence of tumor without jaundice rapidly ensued in 3 patients. They all died, except 1 case, within 18 months from the occurrence of jaundice. This suggests that these patients were in an advanced stage of disease and should be diagnosed early and treated vigorously. Accordingly, cancer of non-liver origin, although rare, should be considered in the differential diagnosis of obstructive jaundice if survival is to be improved in these cancer children.

Adolescent↗
PubMed1989

Acute effects of fever, fasting and aspirin on infant rat gastric mucosa.

Clinical experience shows that young children with gastrointestinal bleeding have frequently had some preceding febrile illness for which aspirin was administered. Febrile young children often have poor food or liquid intake, or have been in a fasting state because of diarrhea, vomiting or anorexia. The objective of this study was to determine the acute effects of fever, fasting and oral aspirin administration on the gastrointestinal mucosa. One hundred and sixty-eight infant rats, from 21 to 28 days of age and weighting from 70 to 120 g were studied. Random assignment was made to eight groups (Grs): Control (Gr I); aspirin administration only (Gr II); fasting only (Gr III); fever only (Gr IV); aspirin and fever (Gr V); fasting and fever (Gr VI); aspirin and fasting (Gr VII); and aspirin, fever and fasting (Gr VIII). Aspirin was given orally in a single daily dose of 200 mg/kg for two days. Fever was induced by an intraperitoneal injection of 0.6 ml salmonella vaccine. Fasting time lasted from 40 to 48 hours (8 hours prior to the beginning of the experiment to the end of study). The severity of the gastric bleeding was estimated by scoring the number of petechiae and the percentage of the hemorrhagic erosion area from grade 0 to 3. Results showed that rats in Grs VII and VIII had significantly more severe grades of petechiae and hemorrhage than the other groups. These were the groups where the risk factors of fasting and aspirin administration coexisted. In addition to fasting, Gr VIII had fever, but this group did not show more gastric mucosal damage than Gr VII showed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Fasting serum gastrin values in normal Chinese children.

To determine the reference ranges and developmental pattern of serum gastrin in Chinese children, fasting serum samples of 362 Chinese infants and children aged from newborns to 14 years were measured by radioimmunoassay. All the participants were healthy and were without gastrointestinal disorders. The mean gastrin values for cord blood (111.55 +/- 68.05 pg/ml) and newborns (100.05 +/- 72.43 pg/ml) are higher than those for adult controls (43.85 +/- 15.59 pg/ml). The mean gastrin value achieves its highest level of 179.86 +/- 94.61 pg/ml on the 3rd day of age. Physiologic hypergastrinemia persists throughout the whole neonatal period. The mean gastrin value for infants between 6 days and 6 months of age is 96.08 +/- 50.05 pg/ml, this decreases to 76.73 +/- 44.23 pg/ml at 7 to 12 months of age, and to 75.89 +/- 43.88 pg/ml at 1 year of age. It reaches the low adult level (40-45 pg/ml) at about 2 years of age.

Adolescent↗
PubMed1988

Hepatitis D virus infection in children with acute or chronic hepatitis B virus infection in Taiwan.

To investigate the prevalence and clinical features of hepatitis D virus infection (HDV) in childhood, total antibody to hepatitis D antigen (anti-HD) in serum samples from 247 children (29 with acute hepatitis B, 68 with chronic hepatitis B, and 150 with asymptomatic hepatitis B surface antigen (HBsAg) carriers with normal liver function profiles) were studied using solid-phase competitive radioimmunoassay. Anti-HD was detected in three of the 29 children with acute hepatitis B and in only one of the 68 with chronic hepatitis B; none of the serum specimens from 150 asymptomatic carriers with normal liver function profile showed detectable anti-HD. All three children with HDV coinfection cleared HBsAg and seroconverted to anti-HBs, whereas one with superinfection finally had normal liver function without clearance of HBsAg. To identify possible sources of HDV infection, HBV markers and anti-HD in family members were also examined. One 4-month-old infant boy became infected through a blood transfusion from his hepatitis B e antigen (HBeAg)-positive carrier father, who had anti-HD. A 4-month-old infant girl was infected through close contact with her HBeAg-negative carrier father, who had HDV superinfection. The infection sources remained undefined in another two patients. The mothers of these four children were seronegative for anti-HD, indicating that perinatal transmission is not the usual mode of HDV infection in Taiwan. The natural course of either acute or chronic HBV infections in childhood in Taiwan may be more closely related to HBV itself, or to some other yet unrecognized factor, rather than to HDV infection.

Acute Disease↗
PubMed1988

Incidence and characterization of Bacillus cereus isolates contaminating dairy products.

A total of 293 dairy products purchased from local markets were examined to determine the incidence of and characterize Bacillus cereus. Isolations were made on mannitol-egg yolk-polymyxin B agar medium and confirmed by several staining and biochemical tests. B. cereus occurred in 17% of fermented milks, 52% of ice creams, 35% of soft ice creams, 2% of pasteurized milks and pasteurized fruit- or nut-flavored reconstituted milks, and 29% of milk powders, mostly in fruit- or nut-flavored milk mixes. The average population of B. cereus in these dairy products was 15 to 280 CFU/ml or CFU/g (range, 5 to 800). The characteristics of these B. cereus isolates in terms of heat resistance, biochemical reactions, and antibiotic susceptibility were similar to previously reported data except for a higher utilization of sucrose. Some isolates were especially resistant to carbenicillin, nalidixic acid, streptomycin, and tetracycline. The MICs for the isolates were also determined. All of the tested isolates lysed rabbit erythrocytes; 98% showed verotoxicity, 68% showed cytotonic toxicity for CHO cells, and 3 of 11 selected isolates that showed strong hemolysin activity killed adult mice.

Animals↗
PubMed1988

Arthrobacter viscosus DNA is modified at GATC sequence.

Arthrobacter viscosus DNA was resistance to digestion by restriction enzymes that are sensitive to methylation of the cytosine residue (but not of adenine) within the GATC recognition sequence. Restriction enzymes sensitive to methylation of cytosine in other recognition sequences were not affected. A. viscosus DNA thus appeared to contain methylated cytosine specifically at the GATC sequence.

Animals↗
PubMed1987

Fulminant hepatitis in children in Taiwan: the important role of hepatitis B virus.

In a recent period of 64 months, fulminant hepatitis was diagnosed in 17 children at National Taiwan University Hospital. Eleven patients were younger than 12 months of age. Hepatitis A IgM antibody and delta-antibody were negative in all 17. Eleven (65%) patients had hepatitis B core IgM antibody, fulminant hepatitis B. Two to 5 months before onset of hepatitis. Five of the 11 children had received blood transfusions. Three of the five donors had hepatitis B e antibody (anti-HBe) and were hepatitis B virus DNA-negative hepatitis B surface antigen (HBsAg) carriers; another two were HBsAg negative, screened by a less sensitive reverse passive hemagglutination method. The mothers of all six infants younger than 6 months of age had HBsAg. HBe antigen and antibody were studied in five of these six mothers; all five had anti-HBe. We conclude that hepatitis B virus is the most important cause of fulminant hepatitis in children in Taiwan.

Acute Disease↗
PubMed1987

Childhood hepatocellular carcinoma develops exclusively in hepatitis B surface antigen carriers in three decades in Taiwan. Report of 51 cases strongly associated with rapid development of liver cirrhosis.

To elucidate the etiologic role of chronic hepatitis B virus (HBV) infection and the role of liver cirrhosis in hepatocellular carcinoma (HCC), pathologic and virologic features of the disease were studied in 51 children with HCC; these accounted for 4.3% of 1195 pathologically proven HCC patients examined in the last three decades. Males predominated (M/F = 3.3:1), and the mean age was 11 years (range: 4-15 years). Hepatitis B surface antigen (HBsAg) was detected in the liver and/or serum of 100% of 42 children by immunocytochemical and/or radioimmunoassay, in the serum of 90% of 10 siblings, and more importantly in 94.1% of 17 mothers, suggesting that infection from familial HBsAg carriers, particularly carrier mothers, may contribute to the high incidence. Liver cirrhosis was frequent (74%), especially in the unresectable cases (87%); in the 20 children under 9 years of age, 95% were cirrhotic, a significantly higher level than the 58% of the 26 older children, P less than 0.005. All but one had advanced HCC, with 1-year survival in only 10.5%. The advanced HCC coupled with young age suggests that HCC can develop rapidly. The low positive rates of serum hepatitis B e antigen (HBeAg, 18%) and liver hepatitis B core antigen (11%) coupled with high frequency of liver cirrhosis indicate that an early HBeAg seroconversion to anti-HBe, in association with severe liver injury, may play an important role in the rapid development of HCC in children.

Adolescent↗