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Biomedical subjects

C H Chiu

Publications and source records attributed to C H Chiu.

At least 91 records · Page 5Linked to original sources
PubMed1996

Rapid identification of Salmonella serovars in feces by specific detection of virulence genes, invA and spvC, by an enrichment broth culture-multiplex PCR combination assay.

In order to make a rapid and definite diagnosis of Salmonella enteritis in children, an enrichment broth culture-multiplex PCR combination assay was devised to identify Salmonella serovars directly from fecal samples. Two pairs of oligonucleotide primers were prepared according to the sequences of the chromosomal invA and plasmid spvC genes. PCR with these two primers would produce either one amplicon (from the invA gene) or two amplicons (from the invA and spvC genes), depending on whether or not the Salmonella bacteria contained a virulence plasmid. The fecal sample was diluted 10- to 20-fold into gram-negative enrichment broth and incubated to eliminate inhibitory compounds and also to allow selective enrichment of the bacteria. One or two amplicons were obtained, the expected result if Salmonella bacteria were present. The detection limit of this PCR was about 200 bacteria per reaction mixture. The primers were specific, as no amplification products were obtained with 18 species and 22 isolates of non-Salmonella bacteria tested which could be present in the feces or cause contamination. In contrast, when 23 commonly seen Salmonella serovars (38 isolates) were tested, all were shown to carry the invA gene and seven concomitantly harbored the spvC gene of the virulence plasmid. This assay was applied to the diagnosis of Salmonella enteritis in 57 children who were suffering from mucoid and/or bloody diarrhea. Of the 57 children, 38 were PCR positive and 22 were culture positive. There were two culture-positive samples that were not detected by PCR. Thus, this PCR assay showed an efficiency of 95% (38 of 40), which is much higher than the 60% (24 of 40) by culture alone. Not only is this method more sensitive, rapid, and efficient but it will cause only an incremental increase in the cost of stool processing, since enrichment cultivation of fecal samples from diarrheal patients using gram-negative enrichment broth is a routine practice for identification in many diagnostic microbiology laboratories. This PCR method, therefore, has clinical application.

Bacterial Proteins↗
PubMed1996

Congenital anomalies following maternal varicella infection during early pregnancy.

We report a typical case of congenital varicella syndrome following a maternal varicella infection during the 10th week of pregnancy. The presenting symptoms in the small gestational age baby were: cicatricial skin lesion, Horner's syndrome,dysphagia with resulting aspiration pneumonia and delayed developmental milestones. Serologic studies revealed persistence of varicella zoster virus IgG for at least 10 months. Although congenital varicella syndrome is rare, it should be kept in mind when counseling families where maternal varicella infection has occurred during the first 20 weeks of gestation. A maternal history of varicella infection, typical manifestations and serologic proof are crucial in the diagnosis of congenital varicella syndrome.

Abnormalities, Multiple↗
PubMed1995

Fate of a redundant gamma-globin gene in the atelid clade of New World monkeys: implications concerning fetal globin gene expression.

Conclusive evidence was provided that gamma 1, the upstream of the two linked simian gamma-globin loci (5'-gamma 1-gamma 2-3'), is a pseudogene in a major group of New World monkeys. Sequence analysis of PCR-amplified genomic fragments of predicted sizes revealed that all extant genera of the platyrrhine family Atelidae [Lagothrix (woolly monkeys), Brachyteles (woolly spider monkeys), Ateles (spider monkeys), and Alouatta (howler monkeys)] share a large deletion that removed most of exon 2, all of intron 2 and exon 3, and much of the 3' flanking sequence of gamma 1. The fact that two functional gamma-globin genes were not present in early ancestors of the Atelidae (and that gamma 1 was the dispensible gene) suggests that for much or even all of their evolution, platyrrhines have had gamma 2 as the primary fetally expressed gamma-globin gene, in contrast to catarrhines (e.g., humans and chimpanzees) that have gamma 1 as the primary fetally expressed gamma-globin gene. Results from promoter sequences further suggest that all three platyrrhine families (Atelidae, Cebidae, and Pitheciidae) have gamma 2 rather than gamma 1 as their primary fetally expressed gamma-globin gene. The implications of this suggestion were explored in terms of how gene redundancy, regulatory mutations, and distance of each gamma-globin gene from the locus control region were possibly involved in the acquisition and maintenance of fetal, rather than embryonic, expression.

Alouatta↗
PubMed1995

Cranial nerve palsies and cerebral infarction in a young infant with meningococcal meningitis.

A previously healthy 30-day-old male infant became ill with fever, poor activity, and refusal to feed for 2 days. A cerebrospinal fluid examination revealed 7.15 x 10(8) leukocytes/l with 72% neutrophils, protein 4.6g/l, and glucose 7 mg/dl. Neisseria meningitidis was isolated from the blood and cerebrospinal fluid. On the fourth day of hospitalization, the baby was found to have left oculomotor and facial palsies, which resolved gradually. He was treated with intravenous penicillin for 2 weeks. A repeat CSF examination revealed a high persisting protein level of 2.9 g/l and a computerized tomographic brain scan revealed a cerebral infarction in the bilateral frontal lobes. The treatment was extended to 4 weeks. No relapse of the infection was noted. This is the first case report of an infant with meningococcal meningitis complicated by cranial nerve palsies and cerebral infarction. This and previous reports, show that meningococcal meningitis at an extremely young age is associated with a greater risk of developing neurological complications.

Cerebral Infarction↗
PubMed1995

Serotypes, biotypes and antibiotic susceptibility of 126 clinical isolates of Haemophilus influenzae.

Serotypes, biotypes, and antibiotic susceptibility of 126 Haemophilus influenzae isolates were determined. Five of the 126 isolates were from blood and were encapsulated type b strains; those taken from other sites were not typable. There were 13% biotype I, 36% biotype II, 38% biotype III, 5% biotype IV, 4% biotype V, and 4% biotype VI isolates. Antibiotic susceptibility tests using the standard disk diffusion method showed the following resistance: ampicillin 51%, cefamandole 10%, cefuroxime 3%, chloramphenicol 28%, tetracycline 37% and sulfamethoxazole-trimethoprim 49%. None of the five type b isolates were resistant to cefotaxime, a third generation cephalosporin. The second generation cephalosporins, cefamandole and cefuroxime, showed a superior activity against H. influenzae isolates, compared to other antibiotics. Multiple drug resistance was found in 64 (51%) isolates. Four of the five type b isolates were resistant to multiple drugs. The multiple-resistance pattern most frequently observed was to ampicillin, chloramphenicol, tetracycline and sulfamethoxazole-trimethoprim. Most clinical isolates did not contain plasmids; therefore, the antibiotic resistance of these H. influenzae strains was probably chromosome-mediated.

Drug Resistance, Microbial↗
PubMed1994

Effect of food and oral simulating fluids on dentine bond and composite strength.

The effect of up to 30 days' immersion in 75% ethanol solution and in an artificial saliva (Moi-Stir) on the dentine shear bond strength (SBS) of three adhesive/composite systems (Tenure/Marathon One, Scotchbond Multi-Purpose/Z100 and Optibond/Herculite XRV) was evaluated. Two control series were stored either in 100% humidity or in air. Diametral tensile specimens (DTS) of the composites studied were stored in 75% ethanol for up to 30 days. The fracture mode and morphology of the failure interface were examined by scanning electron microscopy (SEM). Data were analysed using ANOVA and the Tukey LSD test. The SBS for all systems stored in Moi-Stir (24.8 +/- 3.0 MPa) and air (28.3 +/- 3.0 MPa) was not influenced by length of storage. Microscopic (SEM) examination of the debonded air, and Moi-Stir stored specimens showed that failure had primarily occurred through the dentine. Significant decreases (30-50%) in the SBS of all systems occurred after immersion in 75% ethanol. There was no significant difference among brands. The DTS of the composites showed significant decreases as a function of ethanol exposure. Marathon One and Herculite XRV showed significantly lower DTS after 14 days' storage while Z100 showed no reduction in DTS until after 30 days. The decrease in both SBS and DTS after storage in ethanol was a function of the square root of time (P < 0.001) and followed Fick's laws of diffusion. Ethanol diffusivity was approximated as 1.8 x 10(-6) cm2 s-1 for both SBS and DTS specimens, suggesting that alcohol attack in SBS specimens occurred primarily in the composite system.(ABSTRACT TRUNCATED AT 250 WORDS)

Composite Resins↗
PubMed1994

Application of criteria identifying febrile outpatient neonates at low risk for bacterial infections.

A total of 254 previously healthy outpatient neonates 31 days of age or younger with a rectal temperature > or = 38 degrees C were enrolled in a prospective study during an 18-month period to evaluate the validity of applying low risk criteria for bacterial infections in this population. All of the neonates received standard physical examinations and laboratory evaluations including blood and urine cultures at the time of admission. Those who had no evidence of ear, eye, soft tissue, umbilical or skeletal infection had between 5000 and 15,000 white blood cells/mm3, had a C-reactive protein of less than 20 mg/liter or an erythrocyte sedimentation rate less than 30 mm/hour and a normal urinalysis were considered at low risk for bacterial infections. Bacterial infections were confirmed by cultures of the various body fluids. Bacterial infections were present in 17.7% (45 neonates) and bacteremia or meningitis in 5.1% (13 neonates). Eight (6.0%) of the 134 neonates who met the criteria had bacterial infections, while only 1 (0.7%) had bacteremia and meningitis, compared with 37 (30.8%) and 12 (10.0%), respectively, of the 120 who did not meet the criteria (both P < 0.05). The negative predictive value of meeting the low risk criteria were 94.0% for excluding all bacterial infections and 99.3% for bacteremia and meningitis respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗
PubMed1993

Further characterization of the redox and spectroscopic properties of Azotobacter vinelandii ferritin.

Bacterial ferritin from Azotobacter vinelandii (AVBF) has many properties in common with and a number of properties distinct from the more thoroughly studied animal ferritins. The most notable differences are the high phosphate content of the mineral core and the presence of heme (12 per AVBF) in AVBF. In both ferritin types, redox reactions are essential to the iron release and deposition function of the ferritins. The heme reduction potential in apo AVBF is pH independent as are both the heme and core reduction potential in holo AVBF. pH measurements confirm the pH independence for heme reduction in apo AVBF; however, they establish the conflicting result that 1.7 +/- 0.2 protons per iron atom are taken up during core reduction. These results are interpreted as a two-step reduction process consisting of a pH independent reduction of heme in holo AVBF followed by a pH dependent reduction of the mineral core. Detailed spectroscopic studies have been undertaken to determine if heme-core interactions are detectable during the redox reactions of AVBF. Optical spectroscopy of the heme groups in apo AVBF demonstrate that all twelve are identical and undergo uniform and rapid reduction. EPR spectroscopy establishes the presence of both low-symmetry, g = 4.3, Fe3+ from the mineral core and low-spin heme with g values of 2.87, 2.32, and 1.46 in holo and identical g values for the low-spin heme in apo AVBF. EPR integration of the heme groups in both apo and holo gave values of 13.2 +/- 1.3 heme spins per AVBF at 4.2, 10, 25, 35, and 45 K. No heme perturbations were detected in holo or apo AVBF by Resonance Raman and circular dichroism spectroscopy. Both reduced and oxidized apo AVBF gave normal fluorescence emission at 330-340 nm when excited at 279 nm. These spectroscopic, redox, and reactivity results provide more detailed properties of AVBF for comparison with other bacterial and animal ferritins.

Azotobacter vinelandii↗
PubMed1993

Radiometric and spectroradiometric comparison of power outputs of five visible light-curing units.

The spectral distributions of the radiation emitted by five visible range curing lights were measured spectroradiometrically. The light intensities in specific wavelength bands were evaluated by graphical integration. The results were then compared with the instantaneous readings of power density of all of the units as measured with a commercial curing radiometer. The data obtained by both techniques correlated well at narrower specific wavelengths (450-500 nm), which are assumed to be more effective for photopolymerization. This finding indicates that curing radiometer is sensitive to the desired wavelengths and may be an effective tool to quickly characterize the curing efficiency of dental photocuring sources in a clinical setting.

Absorption↗
PubMed1993

Primary chylopericardium: report of a case.

A 14-year-old girl was admitted due to exertional dyspnea of one month's duration. A grade 3/6 holosystolic murmur with distant heart sounds was heard at the left sternal border. Chest roentgenograms and echocardiograms showed a large amount of pericardial and left pleural effusion and a small perimembranous ventricular septal defect. Subxyphoid pericardial drainage and left pleural intubation were performed. The fluid from both sites was defined as chyle by the milky white appearance, presence of microscopic fat droplets and the lymphocyte predominance in the white cell count. Lymphangiograms and a chest computed tomographic scan demonstrated thoracic duct obstruction and leakage of contrast to pericardial and pleural spaces. The patient was treated with a medium chain triglyceride diet. Unfortunately, massive reaccumulation of the effusion was later noted. Therefore, a median sternotomy with ligation of the thoracic duct, creation of a posterior pericardio-pleural window and implantation of a left pleuro-peritoneal shunt with a Denver peritoneo-venous shunt were performed. Follow-up for one year with two-dimensional echocardiograms showed no more accumulation of the pericardial effusion.

Adolescent↗
PubMed1991

[Changing seroepidemiology pattern of hepatitis B virus infection among elementary and junior high school children in Keelung, Taiwan, 1988].

A large-scale seroepidemiologic study of 20816 (35.6% of total) elementary and junior high school children (grades 1-9) in Keelung, Taiwan was conducted in April-May 1988. The study was to investigate the current status of hepatitis B virus (HBV) infection and to plan the extension of the present HBV prevention program to other age groups. Two HBV markers, hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs), were determined by enzyme immunoassay. The overall seropositivity rates of HBsAg and anti-HBs were 19.0% and 25.6%, respectively. Only 0.4% of the children studied were concurrently positive for both HBsAg and anti-HBs and 55.8% of them were negative for these two markers. It is noteworthy that the seropositivity rate of HBsAg increased with increasing age, from 15.4% in grade 1 (ages 6) to 23.7% in grade 9 (ages 15). This rate of HBsAg was not higher than the 1986 findings (14.0-25.5%) screened from children (4-13 years old) in Keelung, by comparing each age cohort strata, even though the age of study population was two years older. These data indicate that the current hepatitis control strategies have resulted in the reduction of the hepatitis B carrier rate among children from more than 20% to 15% at age 6 (grade 1) in Keelung, but the reduction is still higher than in Taipei children (10%). The seropositivity rate of anti-HBs was also increased with increasing age, from 13.5% (grade 1) to 44.1% (grade 9) and was similar to previous findings in Taiwan.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[An epidemiological study of oral cancer in Taiwan].

Southeast Asia, which includes Taiwan, has one of the highest incidences of oral cancer in the world. From a public health or a clinical dental viewpoint, it is important to study the epidemiologic characteristics of oral cancer in Taiwan. This paper presents epidemiologic data on oral cancer in Taiwan from 1981-1986. The data, gathered from Cancer Registry Center, Department of Health, Executive Yuan, ROC, is studied using the descriptive method. The age-standardized incidence rates for males and females were 4.45/100,000 and 1.42/100,000, respectively. The cumulative incidence rate (0-79 years) was 0.59% for males and 0.19% for females, respectively. The average age was 52.0 years for males and 53.4 years for females. The male/female ratio was 3:1. The most frequently affected sites were the tongue for males and major salivary glands for females. The incident rates were found to be significantly higher in central Taiwan, especially for males. Epidermoid carcinoma was the most common histopathologic type of oral cancer for both sexes.

Age Factors↗
PubMedDate not supplied

School-aged children with Kawasaki disease: high incidence of cervical lymphadenopathy and coronary artery involvement.

OBJECTIVE: We describe 10 school-aged children with Kawasaki disease (KD) with a high incidence of cervical lymphadenopathy and coronary abnormality. METHODS: Based on a database of 1002 children with KD in Chang Gung Children's Hospital from January 1983 to March 2001, 10 (1%) school-aged patients (five boys, five girls) who met the diagnostic criteria of KD were included for analysis. RESULTS: Cervical lymphadenopathy was noted in all (100%) of these patients. Unilateral neck mass mimicking acute suppurative infections not responding to antibiotic therapy was the initial presentation in nine (90%) of the 10 patients. The mean interval between disease onset and diagnosis was 9.9 +/- 3.3 days (range, 6-15 days). Seven (70%) of these patients responded to one course of high-dose intravenous immunoglobulin (IVIG) therapy (2 g/kg) and oral aspirin (80-100 mg/kg per day), two (20%) required a second course of IVIG, and one (10%) responded to high-dose aspirin treatment only. Coronary artery abnormality (dilatation or aneurysm) was documented by echocardiography in seven (70%) patients (four boys, three girls). In six patients, the coronary artery abnormalities resolved in 1 year, while one patient had persistent right coronary artery aneurysm, which necessitated continued anticoagulant and low-dose aspirin therapy. CONCLUSION: The incidence of school-aged children among patients with KD is about 1% in our hospital. These patients are notable for the high incidence of initial manifestations of unilateral neck mass and coronary artery involvement. This disease should be listed as the differential diagnosis in school-aged children presenting with fever and neck mass that do not respond to antibiotic therapy.

Aspirin↗