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Biomedical subjects

L M Huang

Publications and source records attributed to L M Huang.

At least 73 records · Page 4Linked to original sources
PubMed1993

Primary infections of Epstein-Barr virus, cytomegalovirus, and human herpesvirus-6.

A total of 121 infants entered a cohort serological study of primary infections with herpes-viruses. All of them had seven samples of blood available: the first sample was taken soon after birth, the other six were taken at 1, 2, 3, 6, 12, and 14 months of age. One sample of maternal blood was collected immediately after delivery. All blood samples were tested for antibodies against cytomegalovirus, Epstein-Barr virus, and human herpesvirus-6 (HHV-6). Primary cytomegalovirus infection occurred early; the cumulative infection rates were 1.7%, 8.3%, 18.3%, 25%, 52.5%, and 65% by the ages of 1, 2, 3, 6, 12, and 14 months, respectively. Epstein-Barr virus infection was not seen before 3 months of age and slowly emerged thereafter, reaching a cumulative rate of 1.7%, 11.6%, 21.5% at the ages of 6, 12, and 14 months, respectively. Primary HHV-6 infection was also a rare event in the first three months of life, but peaked between 6 and 12 months of age. No detectable risk factors were associated with primary Epstein-Barr virus or HHV-6 infection. The risk factors associated with cytomegalovirus infection included breast feeding, fewer children in household, and care by a babysitter.

Age Factors↗
PubMed1993

5'- and 5-deiodinase activities in adult rat cecum and large bowel contents inhibited by intestinal microflora.

Enzymatic mechanisms for deiodination of 3,5,3'-triiodothyronine or thyroxine in the phenolic ring (5'-deiodinase) or tyrosyl ring (5-deiodinase) are found in cells of many organs, including the intestinal wall. Deiodinases are highly active in intestinal tissue of developing rat fetuses and relatively inactive in adult intestinal cells, but little is known about these systems in the luminal contents of intestines. We have found both 5- and 5'-deiodinase activities in adult rat intestinal contents and have shown that their expression is inhibited by resident intestinal microflora, which are normally present in the adult but not in the fetus, possibly because they are bound by intestinal bacteria in the adult.

Animals↗
PubMed1992

Detection of human herpesvirus-6 DNA by polymerase chain reaction in serum or plasma.

Human herpesvirus-6 (HHV-6) is a newly identified human pathogen. Currently clinicians rely mainly on blood lymphocyte culture and serological tests to diagnose HHV-6 infection. The polymerase chain reaction (PCR) was carried out on the plasma or sera of patients to determine the value of PCR in the diagnosis of HHV-6 infection. A total of 30 patients entered the study; 10 were experiencing acute HHV-6 infections and 20 were healthy and served as controls. HHV-6 DNA was detected by PCR in the serum or plasma of the 10 cases with acute HHV-6 infections. All 20 controls had no HHV-6 DNA in their sera. The time for serum to become PCR-positive coincided with the appearance of IgG HHV-6 antibody. The relatively late presence of HHV-6 DNA in serum might result from late lysis of infected cells by immune responses. It is concluded that detection of HHV-6 DNA by PCR in the serum is a valuable tool for the diagnosis of acute and/or active viral infection.

Adult↗
PubMed1992

Long-term observation of pediatric aplastic anemia.

Fifty-nine verified cases of acquired aplastic anemia (AA), diagnosed at the Pediatric Department of the National Taiwan University Hospital from 1977 to 1987, were reviewed and analyzed. The demographic features showed a high relative incidence (acute myelogenous leukemia/AA ratio, 2.2/1), a high percentage of non-severe AA (39%) and a high association with hepatitis (20.8%). No evidence of hepatitis A, B or C virus infection was found in five cases of hepatitis-associated AA. No sex preponderance was noted in this pediatric series. The 10-year projected survival rate of the total series approached 55%. The crude two-year-survival and two-year-transfusion-free-survival rates were 59% and 44%, respectively, in the conservative therapy group treated with androgens and steroids; 36% and 32%, respectively, in patients with severe AA in the conservative therapy group; and 73% and 64%, respectively, in the aggressive therapy group treated with cyclosporin, anti-lymphocyte globulin or bone marrow transplant. The major causes of death were hemorrhage (44%) and infection (56%) in the conservative therapy group; but in the aggressive therapy group, two out of three deaths were related to therapeutic complications. Multivariate analysis of prognostic factors revealed that severity and treatment modality were independent risk factors. Only two out of 31 patients who survived more than two years (long-term survivors) experienced late mortalities. At two, five, seven and 10 years after diagnosis, 61%, 55%, 41% and 40% of the long-term survivors had inadequate hematopoietic recovery.

Adolescent↗
PubMed1991

Fulminant childhood hemophagocytic syndrome mimicking histiocytic medullary reticulosis. An atypical form of Epstein-Barr virus infection.

Ten cases of pediatric fulminant hemophagocytic syndrome, encountered between 1986 and 1989, are described. They occurred in the summer, and the patients presented with fever, jaundice, hepatosplenomegaly, pancytopenia, coagulopathy, and abnormal liver function. Bone marrow studies revealed infiltration by atypical T-lymphoid cells, rare B immunoblasts, and mature histiocytes with hemophagocytosis. Initially, histiocytic medullary reticulosis was suspected in six cases. The clinical course was characterized by rapid deterioration, with a mean period of 16 days from onset of fever to death. The main causes of death were coagulopathy with multiple organ failure and opportunistic infection. In seven of eight cases studied by serologic assay and Southern blot hybridization, acute or active Epstein-Barr virus (EBV) infection was documented. It is suggested that an atypical or fulminant form of primary EBV infection distinct from classic infectious mononucleosis was prevalent in previously healthy children in Taiwan. Younger age involvement and seasonal clustering were characteristic of the disorder described.

Blood Cell Count↗
PubMed1991

The protective efficacy of recombinant hepatitis B vaccine in newborn infants of hepatitis B e antigen-positive-hepatitis B surface antigen carrier mothers.

Recombinant hepatitis B vaccine has been shown to be as safe and effective as plasma-derived vaccines. However, its efficacy in the prevention of perinatal infection has not been fully evaluated in an endemic area. We recruited 110 high risk infants born to hepatitis B e antigen-positive-hepatitis B surface antigen (HBsAg) carrier mothers in a study of recombinant vaccine efficacy. They were randomized into 2 groups, A (54 infants) and B (56 infants), to receive 4 doses of vaccine, containing 20 or 10 micrograms of surface antigen, respectively, at 0, 1, 2 and 12 months of age. An additional 60 high risk infants were recruited later (Group C) and received three 20-micrograms doses of vaccine at 0, 1 and 6 months of age. All infants also received a dose (145 IU) of hepatitis B immunoglobulin soon after birth. Sera were collected at 0, 1, 2, 3, 6, 12 and 14 months of age to assay HBsAg and anti-HBs. At 12 months of age the HBsAg carrier rates were 7.4 and 1.8%, in Groups A and B, respectively. In Group C the HBsAg-positive rate was 3.3%. HBsAg was invariably first observed between 0 and 2 months of age. Virtually all noncarrier infants developed substantial titers of anti-HBs at 12 months of age. No serious adverse effect was observed after vaccination.

Carrier State↗
PubMed1991

Meningitis caused by human herpesvirus-6.

Since the discovery of human herpesvirus-6 (HHV-6) the illnesses associated with it have increased steadily. Two infants with meningitis are reported: both suffered a mild meningitis and serological studies confirmed an acute HHV-6 infection. This report supports a role of HHV-6 in nervous system disease.

Exanthema Subitum↗
PubMed1991

Roseola infantum caused by human herpesvirus-6: report of 7 cases with emphasis on complications.

Roseola infantum is not an uncommon disease in children. The etiology was not known until 1988 when Yamanishi et al in Japan first demonstrated that human herpesvirus-6 (HHV-6) was the causative agent. In the fall of 1989, we began to study the role of HHV-6 in roseola infantum in Taiwan. A total of 7 cases of suspected roseola infantum were studied and all were proven to have primary HHV-6 infections. Six were classic cases of roseola infantum, while one had only fever without the rash. Two cases developed complications; one had leukopenia and thrombocytopenia and the other had aseptic meningitis and mononucleosis. This is the first report to substantiate that HHV-6 is an important cause of roseola infantum in Taiwan, and that the virus could cause meningitis and thrombocytopenia.

Exanthema Subitum↗
PubMed1991

Immunogenicity of primary DPT vaccination.

Children have been given the diphtheria and tetanus toxoid and pertussis vaccine (DPT) in Taiwan for more than 30 years. Yet, the antibody responses to DPT have not been investigated in recent years. Two new antigens of Bordetella pertussis, pertussis toxin and filamentous hemagglutinin, were identified in B. pertussis several years ago and became the constituents of a new type of pertussis vaccine, acellular vaccine. This study was undertaken to test the antibody responses toward diphtheria, tetanus, and pertussis with conventional methods as well as new methods to detect antibodies against pertussis toxin and filamentous hemagglutinin. A total of 104 children, at ages between 12 and 23 months, who had received 3 doses of DPT vaccine were tested. Almost all (99%) of them possessed diphtheria and tetanus antitoxin concentrations above the protective level. With the criteria derived from an animal study, at least 85% of the vaccinees might have protective antibodies against pertussis. This serological study showed the effectiveness of the present DPT vaccine in Taiwan. If a new DPT vaccine is to be introduced into Taiwan, it should have at least the same immunogenicity as the present vaccine.

Antibodies, Viral↗
PubMed1990

Effect of monovalent measles and trivalent measles-mumps-rubella vaccines at various ages and concurrent administration with hepatitis B vaccine.

To determine the most suitable vaccination schedule in developing countries, a study was conducted to reevaluate the immunogenicity of monovalent measles vaccine and trivalent measles-mumps-rubella vaccine at different ages. The success rate of measles vaccination was 84% at 9 months, 88% at 12 months and 100% at 15 months of age. Vaccination with measles vaccines at 9 and 15 months of age was also 96% immunogenic. Most vaccinees (16 of 17) not responding to the first measles vaccine before 1 year of age developed measles antibody with another shot of vaccine after 15 months of age. Trivalent measles-mumps-rubella vaccine worked well in children ages 14 to 18 months. Administering trivalent vaccine and hepatitis B vaccine concurrently at 1 year of age, rubella and mumps antibodies developed in more than 95% of vaccinees, while measles antibody was detected in 88%. Responses to hepatitis B vaccine in this situation were good; 89% of vaccinees developed antibody against hepatitis B surface antigen (greater than or equal to 10 mIU/ml) and the geometric mean titer was 362.49 mIU/ml. In summary vaccination twice at 9 and 15 months is effective and is a useful regimen in developing countries where measles is still endemic. Trivalent vaccine and hepatitis B vaccine will not interfere with each other when given together at 1 year of age.

Age Factors↗
PubMed1981

Local anesthetics QX 572 and benzocaine act at separate sites on the batrachotoxin-activated sodium channel.

We have studied the effect of local anesthetics QX 572, which is permanently charged, and benzocaine, which is neutral, on batrachotoxin-activated sodium channels in mouse neuroblastoma N18 cells. The dose-response curves for each drug suggest that QX 752 and benzocaine each act on a single class of binding sites. The dissociation constants are 3.15 X 10(-5) M for QX 572 and 2.65 X 10(-4) M for benzocaine. Equilibrium and kinetic experiments indicate that both drugs are competitive inhibitors of batrachotoxin. When benzocaine and QX 572 are present with batrachotoxin, they are much more effective at inhibiting Na+ flux than would be predicted by a one-site model. Our results indicate that QX 572 and benzocaine bind to separate sites, each of which interacts competitively with batrachotoxin.

Anesthetics, Local↗
PubMedDate not supplied

Intravenous sulbactam/ampicillin in the treatment of pediatric infections.

A total of 82 patients involving 83 episodes of proven or presumed bacterial infection were treated with sulbactam/ampicillin. These included 36 cases of soft tissue infection or abscess, four cases of joint or bone infection, 20 cases of respiratory tract infection (17 cases of pneumonia, two of otitis media, and one of tonsillitis), 15 urinary tract infections, three cases of enterocolitis, one case of infective endocarditis, two cases of septicemia, and two of peritonitis. The causative pathogen was isolated in 48 cases (49 infections). These pathogens included Staphylococcus aureus 13 cases, Staphylococcus epidermidis one, Streptococcus pyogenes two, Streptococcus pneumoniae two, Viridans group streptococcus two, peptostreptococcus one, Haemophilus influenzae one, Escherichia coli 12, Enterobacter cloacae three, Proteus mirabilis one, Acinetobacter calcoaceticus one, Salmonella spp. two, Shigella sonnei one, Bacteroides fragilis one, and polymicrobial infections of various combinations in five cases. No bacterial pathogens were isolated in 34 infections, 14 cases of pneumonia and 15 soft tissue infections. Sulbactam/ampicillin was given by intravenous bolus in a dosage range of 75-450 mg/kg/day in four divided doses for variable periods of time depending on the type and severity of the infection. Of a total of 83 episodes of infections, 80 (96.4%) cases were either cured or improved. Bacteriologic eradication also occurred in 46 (93.9%) of 49 infections. Side effects were diarrhea in two patients, acute hemolytic anemia in one patient, and transient elevations in SGOT and leukopenia in one patient. Side effects disappeared upon completion of treatment. Sulbactam/ampicillin is a safe and effective antibiotic for the treatment of common pediatric infections.

Adolescent↗
PubMedDate not supplied

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↗
PubMedDate not supplied

Typhoid fever presenting as infection-associated hemophagocytic syndrome: report of one case.

This report describes a 13-year-old boy who had high fever with severe pancytopenia and acute psychosis as initial presentation. Bone marrow examination was compatible with infection-associated hemophagocytic syndrome (IAHS). Blood culture showed no growth of bacteria while the culture of bone marrow yielded Salmonella typhi. The clinical condition stabilized shortly after the use of ceftriaxone. This case illustrates that typhoid fever must be included in the differential diagnosis of IAHS. In cases with IAHS, bacterial culture as well as morphological study of bone marrow is necessary for the evaluation of etiological agent and to avoid injudicious use of chemotherapy.

Adolescent↗