Biomedical subjects

M H Chang

Publications and source records attributed to M H Chang.

At least 217 records · Page 12Linked to original sources

PubMedDate not supplied

Pathology of chronic hepatitis B virus infection in children: with special reference to the intrahepatic expression of hepatitis B virus antigens.

The clinical, virologic and pathologic features of chronic hepatitis B virus infection were studied in 66 children, of whom 29 were symptomatic and 37 asymptomatic. The majority (79%) of symptomatic children had histologically aggressive diseases: 11 had chronic active hepatitis and 10 had cirrhosis. In contrast, most asymptomatic children had nonaggressive diseases (35 cases); only 2 had chronic active hepatitis. Nine of the 10 children with cirrhosis were under 6 years of age, and the cirrhosis was often advanced, indicating that hepatitis B virus infection can cause the rapid development of cirrhosis in early life. HBcAg was present in 71% of 62 cases examined and correlated well with the status of HBeAg in serum. Cytoplasmic HBcAg was more frequently associated with aggressive disease than was nuclear HBcAg expression alone or no detectable HBcAg in the liver. A male predominance (75%) was found, particularly in children with aggressive diseases (91%) compared to those with nonaggressive forms of disease (67%). Sera from mothers of 43 of these children were tested for HBsAg, and 51% were positive. HBsAg was particularly common among mothers of children with symptomatic disease (69%) or cirrhosis (100%). These findings suggest that male sex and perinatal infection are important factors in the development of overt chronic hepatitis B and cirrhosis in children.

Adolescent↗

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Correlation of hepatocyte HBsAg expression with virus replication and liver pathology.

To elucidate the biologic significance of hepatocyte HBsAg, its expression patterns were correlated with virus replication and liver pathology in 578 liver biopsies taken from chronic HBsAg carriers aged 1 to 80 years. Five major patterns of hepatocyte HBsAg were identified: homogeneous [intense and discrete, (Pattern A), faint and discrete, (Pattern B) and faint and grouped (Pattern C)]; globular or spotty (Pattern D), and marginal (Pattern E). Pattern A was always associated with viremia and also very frequently with membrane HBsAg expression, but rarely with active liver disease. It occurred most commonly in HBeAg-positive carrier children and young adults, reflecting an early immune tolerance phase with active virus replication. Pattern B was also usually associated with viremia, but very commonly associated with active disease (70%), reflecting active virus replication with enhanced immune response. Pattern E (marginal HBsAg), which was always in group distribution resembling a clonal expansion, predominated the HBeAg-negative phase and was associated with absence of viremia and occurred mostly in older adults with inactive bipolar disease spectrum (normal liver/mild disease or cirrhosis/hepatocellular carcinoma); this reflects a late phase of inactive virus replication or integration. Patterns C and D did not correlate well with viremia, but also tended to have inactive diseases as did Pattern E. These findings suggest that hepatocyte HBsAg expression is closely related to the natural course of chronic hepatitis B virus infection.

Adolescent↗

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Chronic viral hepatitis.

Among hepatitis A to E viruses, hepatitis B, C, and D viruses can cause chronic hepatitis, in both children and adults. Hepatitis B virus (HBV) infection is the most prevalent and important one. Perinatal transmission accounts for about 40-45% of chronic HBV infection in hyperendemic areas. Horizontal transmission through intramuscular injection using non-sterile needles and intrafamilial spread accounts for the other half of carriers. During the natural course of HBV infection, the host gradually clears HBV and hepatitis B e antigen (HBeAg), liver damage and elevation of aminotransferases occur during the process of HBV clearance. The most effective way to eliminate HBV infection is immunoprophylaxis starting since birth. It can prevent both HBV and hepatitis D virus (HDV) infections. Hepatitis C virus (HCV) infection in children occurs mainly in high risk children, such as those who received blood product or injection using non-sterile needles, or infants of HCV viremic mothers, etc. Screening of blood product reduced markedly the prevalence of post-transfusion HCV infection, but the prevention of sporadic cases requires HCV vaccination which is still under investigation.

Child↗

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Follow-up immunogenicity of an inactivated hepatitis A virus vaccine in healthy children: results after 5 years.

Long-term persistence of hepatitis A virus (HAV) serum antibody in vaccinated children has not been demonstrated in previous studies. To study the long-term immunogenicity to HAV vaccine, three doses of strain HM 175 HAV vaccine with 360 enzyme-linked immunosorbent assay units were administered to 107 children, aged from 1.0 to 6.8 years, at 0, 1, and 6 months. The administration of one vaccine dose induced seropositivity (anti-HAV titer > or = 20 mIU ml-1) in 95% of all vaccinees at month 1. All subjects remained seropositive until month 6. The titers of HAV antibody remained above 20 mIU ml-1 in all subjects followed up to 60 months. The geometric mean titer (GMT) reached its peak (3802 mIU ml-1) at month 7, i.e. 1 month after the booster dose, and then declined until the end of follow-up at month 60 (661 mIU ml-1). A trend of higher GMT in female subjects persisted up to month 60. The changes of the GMT over time were best described by the regression equation: log (GMT) = 3.26-0.08 x (age in years) (r = -0.95, P = 0.014). According to this equation, the geometric mean concentration would reach 20 mIU ml-1 at around 24.5 years after the beginning of vaccination. In conclusion, those who completed the recommended three-dose inactivated HAV vaccination series remained seroprotective for at least 5 years. Theoretically, such a vaccination program can provide a protective period of over 20 years in children. This paper may be the first to describe at least 5-year immunogenicity of inactivated HAV vaccination in healthy children.

Child↗

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Neonatal hepatitis: a follow-up study.

Fifty-six patients with moderate to severe neonatal hepatitis were followed for 12 to 78 months. Two died from causes other than hepatitis itself and were free from liver disease at the time of death. Of the remaining 54 patients, seven died of hepatitis, two are living with chronic liver disease and psychomotor retardation, and 45 are living without liver disease. High peak bilirubin levels and liver histologic findings of periportal fibrosis, moderate to severe portal inflammation, and/or diffuse giant cell transformation appear to be major factors predictive for poor outcome. Cytomegalovirus (CMV) infection was a common associated infection. Evidence of CMV infection was found in 22 (49%) of the 45 patients studied. Three of them died, and one is still living with cirrhosis of the liver. Metabolic disorders such as alpha-1-antitrypsin deficiency, galactosemia, and aminoaciduria and/or aminoacidemia were carefully screened but were not found in these cases. A fatal case had a sibling who had died of a similar disease course. Chinese infants may have metabolic and familial cholestasis diseases requiring further investigation.

Bilirubin↗

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Lactose malabsorption and small-intestinal lactase in normal Chinese children.

A total of 852 healthy Chinese children from 1 month to 14 years of age were investigated for lactose malabsorption using the breath hydrogen test. A lactose load of 2 g/kg was administered to 528 children and 1 g/kg to another 324 children. The incidence of lactose malabsorption was significantly different among various age groups and between the two different lactose dosages. While the incidence of malabsorption increased strikingly from the age of 3 to the age of 5 years, the age effect remained constant after the age of 6 years. The lactose load of 2 g/kg induced a higher incidence of malabsorption in study subjects than 1 g/kg did, and the dose effect increased for those aged below 5 years and decreased above 5 years. Small-intestinal lactase was also studied in 34 children aged from 2 months to 15 years. The lactase activity was highest in children 2 years old or younger, gradually decreasing with increasing age. In conclusion, lactase activity in Chinese children decreases gradually after 3 years of age, a finding that correlates well with the results of the breath hydrogen test.

Adolescent↗

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Changing aetiologic patterns of acute viral hepatitis in Taiwanese children.

During 1981-86, 76 children were diagnosed as having acute viral hepatitis at the Department of Pediatrics, National Taiwan University Hospital, which is a major referral centre for hepatitis in children in northern Taiwan. The majority (64%) of children had acute hepatitis B which had occurred mainly during infancy. Perinatal transmission from a hepatitis B e negative surface antigen (HBsAg) carrier mother or infection through blood transfusion from a donor who had escaped notice by a less sensitive screening test (reverse passive haemagglutination test) for HBsAg were the two important modes of transmission of hepatitis B virus. The number of cases of acute hepatitis B declined after 1984, with the beginning of the nation-wide hepatitis B vaccination programme. Due to an outbreak of hepatitis A in northern Taiwan in 1982, the number of cases of hepatitis A peaked that year. Subsequently, cases of acute hepatitis A decreased remarkably. Better socio-economic conditions and improved hygiene might have contributed to the marked decrease of viral hepatitis A. The frequency of non-A, non-B hepatitis remained stable during the study period. It is possible to conclude that the aetiologic pattern of acute hepatitis in Taiwanese children changed during the past 6 years: clinical cases of hepatitis A and B decreased, probably because of more effective control of hepatitis A and B virus infections, whereas the control of non-A, non-B virus apparently requires further efforts.

Adolescent↗

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Safety and immunogenicity of hepatitis A vaccine in healthy adult volunteers.

The immunogenicity and adverse reaction of an inactivated hepatitis A (HA) vaccine were investigated. Sixty healthy adult volunteers who lacked antibody to HA virus (anti-HAV) received three doses of vaccine containing 720 enzyme-linked immunosorbent assay (ELISA) units (EL.U) according to a 0, 1 and 6 month schedule. Blood tests for serum liver enzymes and anti-HAV were performed at screening 7 days prior to, and 1, 6 and 7 months after the first dose. Anti-HAV was tested by radio immunoassay and ELISA for titre determination. The seroconversion rates measured by ELISA were 98.3% (59/60) at months 1 and 6 and 100% at month 7. Sixty-one per cent (109/180) of the documented injections were followed by local symptoms, essentially mild soreness at the site of injection; and 22.2% (40/180) by minor general symptoms including malaise, fatigue and lethargy. It is concluded that HA vaccine is highly immunogenic and safe. It may replace immunoglobulin as an effective method of preventing HA virus infection in adults.

Adult↗

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The role of autonomic neuropathy in the genesis of intradialytic hypotension.

BACKGROUND: Intradialytic hypotension is a frequent complication of hemodialysis. Some authors have pointed to autonomic neuropathy as a major cause of intradialytic hypotension. However, other authors have found no such association. METHODS: Tilt-table test and time-domain measures of heart rate variation were used to determine autonomic function. Conventional nerve conduction studies (NCS) were also performed to assess whether intradialytic hypotension is associated with polyneuropathy and autonomic neuropathy. RESULTS: The incidences of polyneuropathy confirmed by standard NCS were similar for the intradialytic hypotensive and normotensive subjects, implying that polyneuropathy is not strongly related to intradialytic hypotension. However, heart rate variation decreased significantly in intradialytic hypotensive subjects, suggesting that isolated autonomic neuropathy plays a major role in the pathogenesis of intradialytic hypotension. One of 9 intradialytic hypotensive subjects had normal autonomic tests and 2 of 18 normotensive subjects had abnormal autonomic function, implying that intradialytic hypotension is not caused by autonomic neuropathy alone. CONCLUSION: Autonomic neuropathy plays an important role in the genesis of intradialytic neuropathy. Tilt-table is easily performed and time-domain measures for heart rate variation are easily determined. Tilt-table test and time-domain measures provide useful information concerning autonomic function.

Adult↗

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Choledochal cyst in infancy: a follow-up study.

From January 1980 to February 1997, 19 cases, 8 males and 11 females, of choledochal cyst were diagnosed before one year old. The majority of patients were diagnosed by ultrasonography before 6 months old (15/19; 79%), including two diagnosed prenatally. According to Todani's classification, type Ia was the most common (74%), followed by type Ic (26%). Fourteen patients underwent Roux-en-Y choledocho- or hepatico-jejunostomy and cyst excision, 3 patients underwent Kasai operation, and I patient underwent external biliary drainage only. The remaining one patient with Trisomy 18 anomaly refused operation. Four of the 10 patients in whom liver histologic examinations were performed, had liver cirrhosis. The follow-up period of these patients ranged from 6 months to 9 years, with a mean of 4.1 years. We divided these 19 cases into 2 groups, according to the presence or absence of biliary atresia. In the 7 infants with biliary atresia (37%), all presented with jaundice and alcoholic stool. Two patients died due to delayed presentation and surgery, both had liver cirrhosis. One patient is living with liver cirrhosis. Another patient was lost to follow-up, but frequent cholangitis was noted till 8 months old. The remaining 3 patients are living and well. In the 12 without biliary atresia, 9 patients are living and well. Two patients died, one due to Trisomy 18 anomaly and the other with delayed surgery and liver cirrhosis. One case was lost to follow-up. In summary: 1-) a possibility of the association of biliary atresia in infants with choledochal cyst should be carefully searched and considered as a unique group; 2) ultrasonography is a good diagnostic tool in choledochal cyst during prenatal or infancy period; 3) the mortality cases were characterized by prolonged bile stasis, biliary cirrhosis, delayed surgery, or multiple anomalies; 4) surgery should be performed as early as possible for those with persistent jaundice and light colored stools.

Choledochal Cyst↗

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Carnitine transport defect presenting with hyperammonemia: report of one case.

Carnitine (beta-hydroxy-gamma-trimethylaminobutyric acid) is involved in the transport of long-chain fatty acids into the mitochondrial matrix and removal of potentially toxic acylcarnitine esters. Carnitine transport defect is a very rare metabolic disease. A 7-month-old female infant was found to have consciousness disturbance, hyperammonemia, hepatomegaly and elevated transaminases. Both the concentrations of free carnitine and acylcarnitines in her blood were very low. The diagnosis of carnitine transport defect was confirmed by assays of carnitine uptake and transport in skin fibroblasts. She responded dramatically to carnitine therapy, and there was no hyperammonemia attack for more than 3 years. Her cardiac function also remained normal.

Ammonia↗

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Shock in the pediatric emergency service: five years' experience.

We undertook a retrospective study of the risk factors determining outcome of nontraumatic patients with shock in the pediatric emergency service. From October 1992 through September 1997, 22 patients with the diagnosis of shock were identified, including 11 with septic shock (50%), 7 with hypovolemic shock (32%) and 4 with cardiogenic shock (18%). Their age ranged from 2 months to 19 years old. Among the cases, 14 patients (64%) had other underlying diseases. Gram-negative bacterial sepsis (6/11, 55%), dilated cardiomyopathy (2/4, 50%) and acute gastroenteritis (7/7, 100%) were the most frequent causes of septic, cardiogenic and hypovolemic shock, respectively. In total, 12 patients (55%) died. The mortality rate was high in septic shock (9/11, 82%) and cardiogenic shock patients (3/4, 75%), but low in hypovolemic shock patients (0/7, 0%). The risk factors of poor outcome in patients with shock included thrombocytopenia, prolonged prothrombin time and partial thromboplastin time. Patients with leukopenia, a higher level of C-reactive protein, or under 2 years of age tended to have poor outcome.

Adolescent↗

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Isolation of Eikenella corrodens from polymicrobial hepatic abscess: report of one case.

Eikenella corrodens is a rare cause of hepatic abscess. We report a case of a hepatic abscess caused by (1) Bacteroides fragilis, (2) Streptococcus constellatus and (3) E. corrodens, which illustrates potential problems of antibiotic coverage due to the presence of Eikenella species. The infection followed an episode of acute gastroenteritis and the clinical course appeared indolent evolving over one week. Besides empirical antibiotics, initial percutaneous aspiration was performed and yielded pus which grew E. corrodens concomitantly with Streptococcus species. E. corrodens was sensitive to penicillin but resistant to clindamycin and metronidazole. But B. fragilis was resistant to penicillin. So the antibiotics were switched to amoxicillin/clavulanate. Unfortunately fever persisted and the abscess increased in size. Therefore echo-guided percutaneous drainage with pigtail catheter was installed. Fever subsided 5 days later. After 21 days treatment of antibiotics, the patient was discharged in good condition despite having some sterile fluid in the residual abscess cavity. Two months after discharge the follow-up echogram confirmed complete resolution of the residual abscess. This patient shows us the existence of E. corrodens in pediatric patients, especially when the hepatic abscess is very likely from the spread of an oral or abdominal infection.

Anti-Bacterial Agents↗

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Immunogenicity and reactogenicity of two recombinant hepatitis B vaccines in healthy adolescents on two-dose schedule.

This is an open, randomized study to compare the immunogenicity and reactogenicity of two recombinant hepatitis B virus (HBV) vaccines. The HBV-NF is a new formulation with a new adjuvant phenoxyethanol which replaced the conventional adjuvant of a commercially available recombinant HBV vaccine (Engerix-B). These two vaccines had the same 20 micrograms hepatitis B surface antigen (HBsAg). They were administered to the deltoid muscle of 116 healthy adolescents, aged between twelve and eighteen years, according to the 0, 6-month schedule. Serum was taken at month 0, 1, 6, and 7. Antibody to HBsAg was tested by radioimmunoassay. Geometric mean titers of both vaccines displayed no significant difference at month 1, 6, and 7. Following the second dose of vaccine, the seroprotection titer (10 mIU/ml) rates at month 7 were 90.9% in HBV-NF and 93.4% in Engerix-B, respectively (p = 0.43). The incidences of local and general adverse reactions were from 3% to 7% without significant difference between the two vaccines and the reactions were all mild and tolerable. Based on this study, regimens of this two-dose schedule proved to be safe and immunogenic, which may provide a cost-effective alternative for HBV mass vaccination program in adolescents.

Adolescent↗

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Steroids used to desensitize penicillamine allergy in Wilson disease.

Patients with Wilson disease require life-long treatment and penicillamine is the drug of choice. We present a 14-year-old boy with Wilson disease who developed hypersensitivity reaction 2 days after starting penicillamine therapy. His symptoms included fever, maculopapular rash and lip edema. The allergic reaction disappeared when penicillamine was discontinued, but relapsed after reinstituting penicillamine at a lower dose. Desensitization was attempted by introducing steroid therapy, the dose of 0.7 mg per kilogram per day of prednisolone for 2 days, then penicillamine was successfully tolerated. Subsequent tapering of the daily prednisolone dose was performed till it was discontinued one month after treatment began. We suggest that concomitant use of steroid and penicillamine should be used for the treatment of patients who develop penicillamine intolerance.

Adolescent↗

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Hereditary fructose intolerance presenting as Reye's-like syndrome: report of one case.

Hereditary fructose intolerance (HFI) is an autosomal recessive disease caused by catalytic deficiency of aldolase B (fructose-1, 6-bisphosphate aldolase). Herein we report on a case of hereditary fructose intolerance with initial presentation of episodic unconsciousness, seizure, hypoglycemia, hepatomegaly, and abnormal liver function since the patient was 11 months old. She was diagnosed as Reye's-like syndrome according to a liver biopsy done at 20 months of age. As she grew up, cold sweating, abdominal pain or gastrointestinal discomfort shortly after the intake of fruits was noted and she developed an aversion to fruits, vegetables and sweet-tasting foods. At 9 years of age, a fructose tolerance test signified a positive result that induced hypoglycemia, transient hypophosphatemia, hyperuricaemia, elevation of serum magnesium, and accumulation of lactic acid. Appropriate dietary management and precautions were recommended. The patient has been symptom-free and exhibited normal growth and development when followed up to 12 years of age.

Child↗

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Recurrence of intussusception in childhood.

Intussusception is the most common cause of intestinal obstruction between 3 months and 6 years of age. Recurrence after reduction of intussusception in childhood is not rare. To assess the incidence and determinants of recurrence of intussusception in childhood, we conducted a prospective observation in an emergency service of a large referral center during a four-year period. We encountered 89 cases with intussusception of whom nine cases (10.1%) had episodes of recurrent intussusception. Five patients had a single recurrence, three had double recurrence and one had triple recurrence. Age of first intussusception, sex, or concurrent adenovirus infection was not related to the recurrence. None of the 27 patients who needed operative reduction had recurrence, while 9 of 62 patients who were reduced successfully by barium enema developed recurrence (P = 0.05). Compared with the first episode, significantly less vomiting, rectal bleeding and shorter duration of abdominal pain or irritable crying were noted during recurrent episodes. All the recurrent episodes were reduced successfully by barium enema. We conclude that recurrent intussusception in childhood tends to be diagnosed earlier than previous episodes and treated successfully by hydrostatic reduction without complication. Surgical reduction of recurrent intussusception may be reserved for cases of failure of hydrostatic reduction, positive peritoneal sign or existence of pathological lead point because of favorable response to barium reduction. Recurrent intussusception seldom occurs in patients who underwent surgical reduction.

Adolescent↗

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Left paraduodenal hernia presenting as intestinal obstruction: report of one case.

We report a case of internal hernia of the small intestine in a 13-year-old boy with presentation of partial intestinal obstruction. The patient suffered from recurrent abdominal pain and chronic constipation over the past few years. An abdominal mass was suspected from clinical manifestations and images derived from abdominal echography. Upper gastrointestinal contrast study revealed poor motility at the distal jejunum with barium stasis. Follow-up film on the next day delineated medially and downwardly displaced splenic flexure and proximal descending colon. At operation, total herniation of small intestine into a retroperitoneal space through a defect on left mesocolon was noted. A left paraduodenal (mesocolic) hernia was diagnosed. The patient made an uneventful recovery after the hernia was repaired. This report provides unusual image clues of internal hernias of the small intestine presenting as ileus. Though rare, paraduodenal hernia should be taken into account in a differential diagnosis of intestinal obstruction. Early surgical intervention allows uneventful recovery to occur and also prevents the possible complication of gangrenous bowels.

Adolescent↗