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Biomedical subjects

C H Chiu

Publications and source records attributed to C H Chiu.

At least 19 recordsLinked to original sources
PubMed2005

Integron-associated imipenem resistance in Acinetobacter baumannii isolated from a regional hospital in Taiwan.

We investigated the genetic properties of imipenem-resistant Acinetobacter baumannii collected from a regional hospital in Taiwan. Pulsed-field gel electrophoresis demonstrated that the isolates were genetically diverse. Polymerase chain reaction, DNA sequencing, and DNA-DNA hybridisation showed that the bla(IMP-1) gene resided as a cassette in a plasmid-borne class 1 integron in two isolates. The majority of the resistant isolates were plasmid-less and carried no bla(IMP), bla(VIM) or bla(CFI) genes, indicating that other uncharacterised metallo-beta-lactamases or mechanisms other than enzyme production are involved in carbapenem resistance in this group of A. baumannii. We conclude that multidrug resistance of A. baumannii was a combined effect of lateral gene transfer and clonal spread of multiple resistant clones. Strict measures should be implemented to control the further spread of resistance.

Acinetobacter baumannii↗
PubMed2004

Isolation of Salmonella enterica serotype choleraesuis resistant to ceftriaxone and ciprofloxacin.

Salmonella enterica serotype choleraesuis (S choleraesuis) usually causes systemic infections in man that need antimicrobial treatment. We isolated a strain of S choleraesuis that was resistant to ceftriaxone and ciprofloxacin from a patient with sepsis. Ciprofloxacin resistance was associated with mutations in gyrA and parC, whereas the ampC gene (bla(CMY-2)), responsible for ceftriaxone resistance, was carried by a transposon-like mobile element. This element was found inserted into finQ of a potentially transmissible 140 kb plasmid, with an 8 bp direct repeat flanking the junction regions. The appearance of this resistant S choleraesuis is a serious threat to public health, and thus constant surveillance is warranted.

Ceftriaxone↗
PubMed2003

Use of parenteral testosterone prior to hypospadias surgery.

Surgical correction of genital defects was formerly proposed when the size of the penis was sufficient to permit easy surgical repair. To enlarge penile size, temporary stimulation with testosterone or dihydrotestosterone cream has been used; however, the results were not only inconsistent, but absorption was also variable. We report our experience with parenteral testosterone as an adjunct to reconstructive genital surgery in 25 patients aged 6-18 months from July 1999 to December 2000, including 8 with penile hypospadias, 15 with penoscrotal hypospadias, and 2 with perineal hypospadias. Each had a penis that was significantly smaller than usual. Testosterone enanthate 25 mg was given i.m. once per month for a total of three doses before surgical repair. Penile length and glans circumference were measured before therapy and at operation. Side effects such as the development of pubic hair and acne were monitored. Bone age was checked 1 year later. An increase in penile length (from 19.8 +/- 2.4 mm to 23.8 +/- 2.0 mm) and glans circumference (from 27.4 +/- 1.4 mm to 37.84 +/- 2.6 mm) was apparent in all except 2 patients (P < 0.001 for both, paired t-test). Four patients had a significant increase in either penile length or glans circumference after the initial dose so that no further injections were required. No definite secondary effects were found. Preoperative parenteral testosterone therapy thus causes a significant increase in penile length and glans circumference without apparent side effects. We suggest that this therapy prior to microphallic hypospadias repair is appropriate.

Humans↗
PubMed2003

Efficacy of Helicobacter pylori eradication on platelet recovery in children with chronic idiopathic thrombocytopenic purpura.

AIM: Little is known about the influence of environmental factors on the epidemiology of idiopathic thrombocytopenic purpura (ITP). The role of Helicobacter pylori infection in relation to the development and/or persistence of ITP in infected patients remains controversial. Therapy used for eradicating H. pylori has led to a rise in platelet counts in a significant number of adult patients. but few paediatric studies have been undertaken to evaluate such treatment. The aim of this prospective study was to determine the prevalence of H. pylori and to evaluate whether H. pylori eradication can induce chronic ITP regression in children. METHODS: To investigate new, noninvasive techniques for diagnosis of H. pylori infection, an enzyme immunoassay for H. pylori antigens in faeces (HpSA) was evaluated. Patient eligibility criteria included isolated thrombocytopenia (< or = 50 x 10(9) L-(-1)) for more than 6 months without any identifiable cause and either normal or increased marrow megakaryocytes. H. pylori status was monitored before eradication and 4, 12, and 24 mo, after the end of treatment using Premier Platinum HpSA. RESULTS: In this study we evaluated 22 chronic ITP patients, 9 of whom were infected with H. pylori. Using repeated HpSA testing, we demonstrated for eradication of H. pylori after treatment in all infected patients. Five of the nine patients had increased platelet counts that persisted throughout the follow-up period. CONCLUSION: These results should stimulate additional research into the involvement of H. pylori infection in chronic ITP in childhood. This approach may offer an accepted algorithm at least for some of these patients.

Adolescent↗
PubMed2003

Splenic abscess caused by group A beta-haemolytic streptococcus.

UNLABELLED: A case of a pyoderma complicated with splenic abscess and bacteraemia caused by group A streptococcus was treated successfully with antibiotics alone for 4 weeks. To our knowledge, this is the first reported case of splenic abscess associated with group A streptococcal bacteraemia. Advances in antibiotic therapy and imaging techniques have improved the management and outcomes of splenic abscesses. Clinicians should be aware of the possibility of splenic abscess after a pyoderma or a sepsis-like episode. CONCLUSION: Splenic abscesses can be diagnosed by serial ultrasound or CT scan examinations and should be treated with antibiotics for 4-6 weeks.

Abscess↗
PubMed2003

Short-term ceftriaxone therapy for treatment of severe non-typhoidal Salmonella enterocolitis.

AIM: To evaluate the clinical efficacy of a short-course ceftriaxone therapy in the treatment of paediatric patients with severe non-typhoidal Salmonella enterocolitis. METHODS: During a 1 y period, all paediatric patients who were suspected having Salmonella enterocolitis by the presentation of bloody and/or mucoid diarrhoea with or without fever were eligible for the study. Patients with either negative stool cultures or bacteraemia were excluded. Severe enterocolitis was defined as a bloody and/or mucoid diarrhoea associated with high fever persisting for longer than 48 h and signs of moderate or severe dehydration. The patients with severe enterocolitis were assigned to treatment with ceftriaxone (50 mg kg(-1) d(-1)) for 3-5 d, while the rest were given supportive treatment only. Before treatment all study patients received blood testing for white blood cell (WBC) count, C-reactive protein (CRP) level and blood culture. The duration of the fevers was recorded. Patients were followed up after clinical recovery for the possibility of relapse. RESULTS: Seventy-three patients with culture-confirmed Salmonella enterocolitis without bacteraemia were analysed. The duration of fever was longer in severe cases who were treated with ceftriaxone than those who were not. However, rapid defervescene was found after short-course ceftriaxone therapy in those patients with severe enterocolitis. CRP was significantly higher in severe cases. There was no significant difference in the WBC count between the two groups of patients. No relapse was found in these patients. CONCLUSION: High CRP, prolonged high fever and signs of moderate or severe dehydration appear appropriate to define severe cases of Salmonella enterocolitis. Short-course ceftriaxone therapy is clinically beneficial to these patients. Neither clinical nor microbiological relapse was seen after therapy.

Anti-Bacterial Agents↗
PubMed2002

Molecular epidemiology of nalidixic acid-resistant campylobacter isolates from humans and poultry by pulsed-field gel electrophoresis and flagellin gene analysis.

To investigate the potential of poultry products as the source of human infections associated with quinolone-resistant campylobacters, 140 human and 75 poultry isolates of nalidixic acid-resistant campylobacters were collected between 1996 and 1998, and analysed by two molecular typing methods. By the analysis of restriction fragment length polymorphism of the flagellin gene, 33 distinct patterns were obtained, with 18 of which shared by both human (89%) and poultry (93%) isolates. By the pulsed-field gel electrophoresis of SmaI-restricted macrofragments, 105 different profiles were obtained, and 11 were found in both human (40%) and poultry (23%) isolates. When the two typing methods were combined, 112 unique genotypes were obtained, 11 of which were shared by both populations, including 53 (38%) human isolates and 14 (19%) poultry isolates. Although domestic poultry products are still important sources of the quinolone-resistant campylobacter infections in humans, there are other factors that might contribute to these increasing infections simultaneously. A more stringent policy in the use of antimicrobial agents in food animals can no longer be ignored.

Animals↗
PubMed2002

Different proinflammatory reactions in fatal and non-fatal enterovirus 71 infections: implications for early recognition and therapy.

AIM: The mechanism of pulmonary oedema, a life-threatening manifestation of enterovirus 71 (EV71) encephalitis, is unclear. Our aim was to assess the relationship of proinflammatory cytokines to EV71-related pulmonary oedema. METHODS: Proinflammatory responses in 33 EV71 patients with various complications and 21 normal healthy children were measured using an enzyme-linked immunosorbent assay. RESULTS: EV71 patients with both encephalitis and pulmonary oedema were found to have much higher levels of blood interleukin-6 (IL-6) (947 +/- 1239 vs 4.9 +/- 3.1 pg/ml, p = 0.0003), tumour necrosis factor-alpha (TNF-alpha) (22.4 +/- 29.5 vs 5.3 +/- 1.0 pg/ml, p = 0.0035), interleukin Ibeta (IL-1beta) (48.4 +/- 85.2 vs 4.9 +/- 10.1 pg/ml, p = 0.01), white blood cell count (28.3 +/- 7.6 vs 15.5 +/- 6.8 10(9)/L, p > or = 0.0001) and blood glucose (501 +/- 186 vs 165 +/- 117 mg/dL, p = 0.0009) than patients with EV71 encephalitis alone. In fact, the cytokine levels in patients with encephalitis only or in those without complications were not significantly different from the levels found in normal children. The sensitivity, specificity, positive and negative predictive values of IL-6 > 70 pg/ml for EV71 encephalitis with pulmonary oedema were all 100%. CONCLUSION: Patients with EV71-related encephalitis combined with pulmonary oedema were found to have significantly elevated levels of proinflammatory cytokines and the best predictor for this complicated condition was found to be the level of serum IL-6.

Analysis of Variance↗
PubMed2002

Isocupressic acid blocks progesterone production from bovine luteal cells.

The needles of ponderosa pine (Pinus ponderosa Laws.) were reported to induce abortions when fed to late-term pregnant beef cows in North America. An in vivo study of pregnant cows suggested that isocupressic acid (IA) was the main abortifacient isolated from needles and bark of the pine. However, the mechanism of abortifacient activity of IA is not clear yet. In a pregnant cow, the corpus luteum of the ovary helps the maintenance of pregnancy by its progesterone production. This study involved the IA extracted from the root of the Taiwan cypress (Juniperus formosana) and used a frozen-thawed bovine luteal cell culture system to investigate the action of IA on progesterone production. Thawed bovine luteal cells (1 x 10(5) cells/ml/well) in M199 medium were cultured in 24-well culture plates at 37 degrees C in a 5% CO2 incubator. Ten ml of tested drugs, IA at 1 to 1000 ng/ml and/or ovine luteinizing hormone (oLH) at 1 to 100 ng/microl or 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) with 0.1-10 mM, were added into each well. After 4 hours of incubation, the media were harvested and assayed for progesterone by an enzyme immunoassay. Progesterone production from cells was the indicator used to evaluate the action of IA. All tested doses of IA significantly inhibited progesterone production in both basal and oLH stimulating conditions. Also those dosages inhibited cyclic adenosine-3',5'- monophosphate (cAMP) stimulation, suggesting a post-cAMP mechanism is involved in the IA action. We concluded that IA can induce pregnant cows to abort partly through blocking luteal function and may be identified as a new abortifacient chemical.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2001

The tetrapod limb: a hypothesis on its origin.

A wrist joint and structures typical of the hand, such as digits, however, are absent in [Eustenopteron] (Andrews and Westoll, '68, p 240). Great changes must have been undergone during evolution of the ankle joint; the small number of large bones in the fin must somehow have developed into a large number of small bones, and it is very difficult to draw homologies in this region, or even be certain of what is being compared (Andrews and Westoll, '68, p 268). The tetrapod limb is one of the major morphological adaptations that facilitated the transition from an aquatic to a terrestrial lifestyle in vertebrate evolution. We review the paleontological evidence for the fin-limb transition and conclude that the innovation associated with evolution of the tetrapod limb is the zeugopodial-mesopodial transition, i.e., the evolution of the developmental mechanism that differentiates the distal parts of the limb (the autopodium, i.e., hand or foot) from the proximal parts. Based on a review of tetrapod limb and fish fin development, we propose a genetic hypothesis for the origin of the autopodium. In tetrapods the genes Hoxa-11 and Hoxa-13 have locally exclusive expression domains along the proximal-distal axis of the limb bud. The junction between the distal limit of Hoxa-11 expression and of the proximal limit of Hoxa-13 expression is involved in establishing the border between the zeugopodial and autopodial anlagen. In zebrafish, the expression domains of these genes are overlapping and there is no evidence for an autopodial equivalent in the fin skeleton. We propose that the evolution of the derived expression patterns of Hoxa-11 and Hoxa-13 may be causally involved in the origin of the tetrapod limb.

Adaptation, Physiological↗
PubMed2001

Role of calcium-independent phospholipases (iPLA(2)) in phosphatidylcholine metabolism.

The proposed role of calcium-independent phospholipase A(2) (iPLA(2)) in membrane phospholipid homeostasis was tested by examining the perturbation of phosphatidylcholine metabolism by enzyme overexpression. There are alternatively spliced forms of murine iPLA(2) that were widely expressed in mouse tissues: a long form containing exon-9 that is membrane-associated and a short form lacking exon-9 that is distributed between the membrane and cytosolic fractions. Enforced expression of either iPLA(2) isoform led to a significant increase in intracellular free fatty acid, lysophosphatidylcholine, and GPC without a concomitant increase in the incorporation of either exogenous arachidonic acid or choline. The accumulation of lysophosphatidylcholine in iPLA(2)-expressing cells illustrates the limited capacity of cells for reacylation and degradation of lysophospholipids. Since iPLA(2) overexpression did not accelerate either phospholipid remodeling or phosphatidylcholine synthesis, this enzyme does play a determinant (rate-controlling?) role in either of these cellular processes.

Alternative Splicing↗
PubMed2001

Carriage of antibiotic-resistant pneumococci among Asian children: a multinational surveillance by the Asian Network for Surveillance of Resistant Pathogens (ANSORP).

To investigate the nasal carriage of antibiotic-resistant pneumococci by children, anterior nasal swabs were done for 4963 children <5 years old in 11 countries in Asia and the Middle East. In total, 1105 pneumococci isolates (carriage rate, 22.3%) were collected, 35.8% of which were found to be nonsusceptible to penicillin. Prevalence of penicillin nonsusceptibility was highest in Taiwan (91.3%), followed by Korea (85.8%), Sri Lanka (76.5%), and Vietnam (70.4%). Penicillin resistance was related to residence in urban areas, enrollment in day care, and a history of otitis media. The most common serogroups were 6 (21.5%), 23 (16.5%), and 19 (15.7%). The most common clone, as assessed by pulsed-field gel electrophoresis, was identical to the Spanish 23F clone and to strains of invasive isolates from adult patients. Data in this study documented the high rate of penicillin or multidrug resistance among isolates of pneumococci carried nasally in children in Asia and the Middle East and showed that this is due to the spread of a few predominant clones in the region.

Anti-Bacterial Agents↗
PubMed2001

MDM2 and MDMX can interact differently with ARF and members of the p53 family.

Members of the p53 family of transcription factors have essential roles in tumor suppression and in development. MDM2 is an essential regulator of p53 that can inhibit the transcriptional activity of p53, shuttle p53 out of the nucleus, and target p53 for ubiquitination-mediated degradation. Little is known about the interaction and selectivity of different members of the p53 family (p53, p63, and p73) and the MDM2 family (MDM2 and MDMX). Here we show that the transcriptional activities of p53 and p73, but not that of p63, were inhibited by both MDM2 and MDMX. Consistent with these, we found that MDMX can physically interact with p53 and p73, but not with p63. Moreover, ectopically expressed MDM2 and MDMX could induce alterations in the subcellular localization of p73, but did not affect the subcellular localization of p53 and p63. Finally, we demonstrate that while ARF can interact with MDM2 and inhibit the regulation of p53 by MDM2, no interaction was found between ARF and MDMX. These data reveal that significant differences and selectivity exist between the regulation of different members of the p53 family by MDM2 and MDMX.

ADP-Ribosylation Factors↗
PubMed2001

Determination of polychlorinated dibenzo-p-dioxin and dibenzofuran congeners in air particulate and marine sediment standard reference materials (SRMs).

Due to the limited number of environmental matrix certified reference materials (CRMs) with assigned values for natural levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), an interlaboratory study was undertaken by the National Institute of Standards and Technology (NIST) and Environment Canada to establish reference concentration values for selected PCDD/Fs in two well-characterized NIST Standard Reference Materials (SRMs): SRM 1649a (Urban Dust) and SRM 1944 (New York/New Jersey Waterway Sediment). Results from 14 laboratories were used to provide reference values for the seventeen 2, 3, 7, 8-substituted PCDD/F congeners, the totals for individual tetra- through hepta-substituted PCDD/F homologues, and the total amount of tetra- through hepta-substituted PCDD/Fs. The mass fractions for the individual 2, 3, 7, 8-substituted congeners range from approximately 0.01 microg/kg to 7 microg/kg dry mass.

Air Pollutants, Occupational↗
PubMed2001

Endogenous endophthalmitis and necrotising pneumonia caused by Klebsiella pneumoniae in a child with beta-thalassaemia major.

A case beta-thalassaemia major complicated with Klebsiella pneumoniae endogenous endophthalmitis is presented to increase physician awareness of the association of the two clinical conditions. Severe morbidity including subretinal abscess and retinal detachment may develop despite aggressive intravenous and intravitreal ceftriaxone therapy, along with vitrectomy and external drainage.

Adolescent↗
PubMed2001

Acute disseminated encephalomyelitis in autoimmune hemolytic anemia.

A 16-year-old female with chronic autoimmune hemolytic anemia is presented. She was diagnosed with acute disseminated encephalomyelitis by clinical findings and magnetic resonance imaging (MRI), and the condition occurred after a systemic infection with Cryptococcus neoformans. Intravenous immunoglobulin therapy remarkably improved the patient's neurologic deficit and resolved abnormalities evidenced on MRI. To our knowledge, this report is the first of a pediatric patient with autoimmune hemolytic anemia complicated by acute disseminated encephalomyelitis that developed after an apparently successful treatment of cryptococcal meningitis.

Adolescent↗
PubMed2001

Secular trends in incidence and antimicrobial resistance among clinical isolates of Salmonella at a university hospital in Taiwan, 1983-1999.

The incidence and antimicrobial resistance among clinical isolates of salmonella at a university hospital in Taiwan between 1983 and 1999 are summarized in this report. A total of 7986 isolates were analysed. Serogroup B has been the most prevalent over the years, with an apparently continuous decline after 1995. Concordant decrease was also found among S. choleraesuis and S. typhi isolates in recent years. In contrast, the proportion of serogroup D strains increased significantly after 1996. S. typhi remained relatively susceptible to most of the antimicrobial agents examined. For non-typhoidal isolates, antimicrobial resistance to ampicillin (62%), chloramphenicol (67%), and sulfamethoxazole-trimethoprim (37%) was relatively higher than that reported elsewhere. Newer generation cephalosporins and fluoroquinolones remained effective over the years, although emerging resistance to these drugs has been noticed since 1992. A more prudent selection and use of antimicrobial agents, in both humans and animals, and a continuous surveillance of resistance are essential in the future.

Drug Resistance, Microbial↗