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Biomedical subjects

M H Chang

Publications and source records attributed to M H Chang.

At least 145 records · Page 8Linked to original sources
PubMed1992

Spontaneous loss of HBsAg in children with chronic hepatitis B virus infection.

Spontaneous loss of HBsAg is infrequent in adult HBV carriers. Little is known about this serological change in children. In a prospective study of 420 hepatitis B virus-carrier children who were observed for 1 to 12 yr (mean = 4.3 yr), spontaneous loss of HBsAg occurred in 10 patients, with an average incidence of 0.6%/yr. The HBsAg clearance rate was significantly higher in children who had anti-HBe; children who were at an older age on entry; children whose mothers were HBsAg-; or children with severe liver histological changes detected while they were HBeAg+. Children who seroconverted from HBeAg to anti-HBe before the age of 6 or who had a peak serum ALT level above 100 IU/L were more likely to clear HBsAg. In all 10 patients who became HBsAg-, serum hepatitis B virus DNA became undetectable by both spot hybridization and the polymerase chain reaction, suggesting a complete clearance of the virus from serum. After the loss of HBsAg, the anti-HBs levels were higher in the children born to carrier mothers than in those born to noncarrier mothers. These findings suggest that chronic hepatitis B virus-carrier children rarely lose HBsAg, especially if they have been infected during the perinatal period and have mild histological changes. The poor humoral immune response to HBsAg may be a contributing factor in the establishment of carrier status during horizontal infection but may not be primarily involved in the establishment of carrier status during perinatal infection.

Adolescent↗
PubMed1992

Cellular immune response to HBcAg in mother-to-infant transmission of hepatitis B virus.

Cellular immunity to HBcAg was studied in hepatitis B virus carrier children and neonates born to hepatitis B virus carrier mothers. A significant proliferative response of peripheral blood mononuclear cells to HBcAg was found in 5 of 10 children with elevated ALT levels but in none of the nine HBeAg-positive children with normal ALT levels. HBeAg but not HBsAg was detected in cord blood of 9 of 10 neonates born to HBeAg-positive carrier mothers, suggesting exposure of these neonates to HBeAg in utero. However, cord mononuclear cells from neonates born to HBeAg-positive carrier mothers did not show a significant change in the proportion of suppressor and helper T-cell subsets or proliferative response to HBcAg. Nor did they produce interleukin-2 receptor after being cocultured with HBcAg. The unresponsiveness of peripheral-blood mononuclear cells or cord mononuclear cells to HBcAg was not reversed by CD8+ cell depletion. Although cord blood mononuclear cells from neonates born to carrier mothers positive for antibody to HBeAg also did not respond to HBcAg, we encountered an infant, born to a carrier mother positive for antibody to HBeAg, who contracted acute hepatitis B at 2.5 mo of age. The baby's peripheral-blood mononuclear cells showed a significant proliferative response to HBcAg. These results support the view that transplacental maternal HBeAg probably induces a specific unresponsiveness of helper T cells to HBcAg and HBeAg in the neonates born to HBeAg-positive carrier mothers. This specific helper T cell tolerance could be maintained throughout the early replicative phase of carrier state but might break someday with the appearance of raised ALT level.

Adolescent↗
PubMed1992

Transfusion-acquired cytomegalovirus infection in children in a hyperendemic area.

Thirty-nine children without previous cytomegalovirus (CMV) infection received blood transfusion in the National Taiwan University Hospital. The overall transfusion-acquired CMV infection rate was 36% (14/39). Donor CMV seropositive rate was 70%. None of the nine children who had received seronegative blood became infected, in contrast to 14 of the 21 children (67%) who had received seropositive blood (P = 0.002). Another significant risk factor associated with CMV infection was the use of fresh blood: 13 of 15 (87%) with fresh seropositive blood were infected, in contrast to one of six (17%) with "old" seropositive blood (P = 0.01). Most of the fresh blood was used within 24 hours. This blood processing method was shown to account for the extremely high rate of CMV infection in those who had received fresh seropositive blood. The results indicated that the incidence of CMV infection can be reduced by avoiding the use of fresh blood, especially blood less than 24 hours old. For such a population in Taiwan with high prevalence of positive CMV antibody, this approach was more applicable than screening donor blood for CMV antibody.

Adolescent↗
PubMed1992

Changing seroepidemiological patterns of cytomegalovirus infection in children in Taiwan from 1984 to 1989.

The prevalence of cytomegalovirus (CMV) antibody was studied in 966 children in 1984 and 927 children in 1989. The overall prevalence rate of CMV antibody was 59% for children in 1984 and 46% for children in 1989 (P less than 0.05). In both study years, the prevalence rate of CMV antibody was about 70% in infants under 6 months of age, declined to a trough between the ages of 6 and 12 months, and then increased to 40-50% between 1 and 4 years of age. The rate of CMV antibody for children above 4 years in 1984 increased steadily with age and reached 82% by 12 years. In contrast, the prevalence rate in 1989 remained at the level of 40-50% from age 4 to 10 years. It was followed by a sharp increase after 10 years of age and reached 84% at 12 years old. The seropositive rate in each of the 5-, 6-, 8-, 9-, and 10-year-old groups was higher in 1984 than that in 1989. These observations indicated that the prevalence rate of CMV antibody is decreasing in children. This change may be related to various socioeconomic factors, especially the less crowded family conditions in recent years.

Age Factors↗
PubMed1992

Polymerase chain reaction to detect human cytomegalovirus in livers of infants with neonatal hepatitis.

Neonatal hepatitis is closely related to human cytomegalovirus infection in Taiwan, a conclusion based on serological and urine culture studies. To obtain more direct evidence further relating cytomegalovirus to the pathogenesis of neonatal hepatitis, the cytomegalovirus genome was studied in the liver tissues of 50 infants with neonatal hepatitis using the polymerase chain reaction (PCR). Liver tissues from 26 infants with biliary atresia and another 30 infants and children with diagnoses other than neonatal hepatitis, cholestasis, or hepatitis were also studied for comparison. Sequences from the immediate early gene 1 and 2 regions were used as primers. The liver tissues from 23 (46%) of the 50 infants with neonatal hepatitis were positive for cytomegalovirus genome, whereas those of 2 of the 26 infants with biliary atresia and none of the liver tissues from 30 infants and children without neonatal hepatitis were positive for cytomegalovirus genome, by PCR. The results of PCR correlated well with that of serology and urine culture. This study provides further evidence of cytomegalovirus in the pathogenesis of neonatal hepatitis.

Base Sequence↗
PubMed1992

"Numb, clumsy hands" and tactile agnosia secondary to high cervical spondylotic myelopathy: a clinical and electrophysiological correlation.

Four patients presented with a distinctive syndrome of "numb, clumsy hand" and tactile agnosia. Myelography and computed tomographic myelography (CTM) of the cervical spine documented major spondylotic compressive lesions mainly between the C3 and C5 levels. The cortical responses of dermatomal somatosensory evoked potentials (DSEPs) revealed progressively prolonged peak latencies and progressively decreased amplitudes of early components from C6 to C8 dermatomal stimulation. In comparison, the C5 and L2 DSEPs were affected to a lesser extent. This finding suggests that high cervical cord compression may produce dysfunction of the dorsal column caudal to the direct compressive sites. In other words, the funiculus cuneatus of C6-8 cord is most affected in high cervical myelopathy. Moreover, the funiculus cuneatus is within the border zone susceptible to an overall reduction in blood flow. We conclude therefore, that ischemia secondary to cord compression is the pathophysiology resulting in this unique syndrome of "numb, clumsy hands" and tactile agnosia.

Aged↗
PubMed1992

Prevalence of antibody to Epstein-Barr virus DNase in children.

Antibodies to Epstein-Barr-virus-specific DNase in children under 15 years old from Taipei, Taiwan were determined by an enzyme neutralization test. Serum was taken as positive for the anti-DNase antibody when 1 ml of serum could neutralize > or = 2 units of the DNase activity. Among the 1,292 sera tested, 5.6% of the children were shown to have anti-EBV DNase antibodies, a result similar to that for adults. Maternal antibodies against the EBV DNase were found to decrease very rapidly 2 months after the child's birth, and new antibody appeared upon natural EBV infection.

Adolescent↗
PubMed1992

Distal paresthesia in patients with cervical cord lesions.

Nine patients complaining of distal paresthesia were found to have spinal cord lesions with no evidence of peripheral nerve disease. This pattern may be due to central nervous system dysfunction, with a lesion being intramedullary or extramedullary. The sensory deficits were initially asymmetric. Paresthesias could originate from the hands and progress to the stocking-glove pattern. It was usually more severe in hands than in feet. The abnormal somatosensory evoked potentials, found in all patients, indicated a lesion involving the posterior column, a site supposed to be the pathologic basis of paresthesia. As hands and feet have relatively large somatotopic representation in the posterior column of the cervical cord, the paresthesia tends to localize over distal portions of extremities.

Adult↗
PubMed1992

Serum gastrin levels in children with peptic ulcer disease.

Fasting serum gastrin values were measured by radioimmunoassay in 53 children with peptic ulcer disease. The mean fasting serum gastrin levels for children with chronic duodenal ulcer, acute gastric ulcer, acute duodenal ulcer who were younger than two years old and acute duodenal ulcer who were older than two years old were: 46.2 +/- 25.7 pg/mL, 46.9 +/- 43.5 pg/mL, 47.9 +/- 12.0 pg/mL and 37.5 +/- 17.8 pg/mL, respectively. Children with peptic ulcer disease did not have elevated fasting serum gastrin levels when compared with age-matched controls. We conclude that a fasting serum gastrin value cannot be used as a screening test for peptic ulcer disease in children, except for Zollinger-Ellison syndrome.

Adolescent↗
PubMed1992

Congenital short bowel syndrome: report of a case treated with home central parenteral nutrition.

Congenital short bowel is a rare anomaly. Among the 21 cases reviewed in the literature, only four (19%) survived beyond infancy. We present a female infant with short small bowel, malrotation and floating colon, who was successfully treated with home central parenteral nutrition. Improved long-term survival in this group of patients is expected with prolonged parenteral nutritional support.

Female↗
PubMed1992

Correlation between ELISA and recombinant immunoblot assay in serum samples positive for anti-HCV.

To determine the false-positivity of antibody to hepatitis C virus (HCV) (anti-C100-3), the correlation between ELISA optical density (OD), anti-HCV titer and recombinant immunoblot assay (RIBA) in 87 anti-HCV-positive sera was analyzed. The results showed that > 90% of the serum samples with an anti-HCV OD > 2.0 or with titers > 10 x were RIBA reactive. These findings are applicable in daily clinical practice.

Adult↗
PubMed1991

Hepatocellular carcinoma in childhood. Clinical manifestations and prognosis.

From December 1964 to November 1989, 71 children from 3 to 17 years of age with the eventual diagnosis of hepatocellular carcinoma (HCC) presented at the National Taiwan University Hospital (Taipei, Taiwan, Republic of China). Forty-three of them had pathologic proof, whereas 28 were diagnosed on a clinical and laboratory basis. A male predominance (M:F = 3.2:1) was noticed. Most patients presented in a late, advanced stage. Abdominal pain and abdominal mass were the major symptoms and signs, followed by anorexia, fever, and internal bleeding. Hydrocele, purpura, and obstructive jaundice were rare presenting symptoms. Hepatosplenomegaly, superficial venous engorgement, and ascites were the main physical signs. The prognosis for such children with HCC was very poor. Only 10% of the patients survived longer than 1 year after the onset of the initial symptom. Among 49 patients who could be followed, only two had long-term survival of over 5 years. One patient had a small HCC with internal bleeding, whereas the other had a large HCC with abdominal distention. Both received surgical resection, and a resection was repeated for tumor recurrence in the patient with the large mass. The resectability of these 71 patients was low (9.8%). Resectability and nonicterus seemed to be the factors indicating favourable prognosis. Observation indicated that the prognosis for children with symptomatic HCC is grave but surgical resection, whenever possible, should be carried out.

Adolescent↗
PubMed1991

Seroprevalence of hepatitis B virus infection in children in Taipei, 1989: five years after a mass hepatitis B vaccination program.

A nationwide hepatitis B vaccination program was launched in Taiwan in 1984. To study the impact of this ongoing program on hepatitis B virus (HBV) infection, a follow-up seroepidemiologic study was carried out in 1989 in a Taipei district where pre-vaccination seroepidemiology had been studied. HBV markers were studied in 1134 apparently healthy children (619 boys and 515 girls) under 13 years of age between March and July 1989. The prevalence of hepatitis B surface antigen (HBsAg) in children under 5 years of age decreased from 9.3% in 1984 to approximately 2% in 1989. A significant decrease in HBsAg prevalence and hepatitis B core antibody in 5- to 8-year-old children who were not immunized against HBV showed that horizontal infection among the older children had also decreased. Thus, this program not only protected vaccinated subjects; the reduction in numbers of highly infectious young HBV carriers also contributed to a lower prevalence of hepatitis B infection and carrier rates in some older children. This study demonstrates that hepatitis B vaccination is effective in protecting the majority of children in hyperendemic areas from HBV infection and from becoming chronic carriers.

Carrier State↗