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Biomedical subjects

Y C Huang

Publications and source records attributed to Y C Huang.

At least 55 records · Page 3Linked to original sources

Antibody to intercellular adhesion molecule 1 (CD54) decreases survival and not lung injury in baboons with sepsis.

Neutrophil influx into the lung is an important event in the pathogenesis of acute lung injury in gram-negative sepsis. We hypothesized that administration of a monoclonal antibody to intercellular adhesion molecule 1 (ICAM-1, CD54), a molecule mediating neutrophil adhesion to endothelial cells, would decrease neutrophil sequestration and transmigration in the lung and attenuate lung injury in Escherichia coli sepsis. Sepsis was induced in 12 baboons primed with heat-killed E. coli (1 x 10(9) CFU/kg) 12 h before infusion of live bacteria (1 x 10(10) CFU/kg). Six animals received monoclonal antibody to CD54 (1 mg/kg) intravenously at the time of live E. coli infusion. After 48 h or when blood pressure could not be maintained, tissues were harvested and bronchoalveolar lavage (BAL) samples were obtained. Median survival time was decreased in anti-CD54-treated animals. This group also had decreased mean arterial pressure, increased metabolic acidosis, and decreased urine output. Measures of lung injury including gas exchange, lung lavage protein and lactate dehydrogenase (LDH), lung thiobarbituric acid-reactive species, and lung histology, including alveolar neutrophil volumes, were unaffected by treatment. The effect of anti-CD54 on neutrophil influx into tissues as measured by myeloperoxidase was organ specific. These data show that monoclonal antibody to CD54 does not ameliorate acute lung injury in E. coli sepsis, and septic primates given anti-CD54 have worsened metabolic parameters and decreased survival.

Animals↗

A family cluster of streptococcal toxic shock syndrome in children: clinical implication and epidemiological investigation.

BACKGROUND: Most invasive group A streptococcal (GAS) disease occurs sporadically. Reports of family clusters of these infections are scanty, and most invasive disease occurs in adults. We describe a family cluster of streptococcal toxic shock syndrome (STSS) involving 3 children and present the results of an epidemiologic investigation. PATIENTS AND METHODS: During a 16-day period, 3 children in a family developed STSS with an interval of 7 and 9 days, respectively, between the onset of disease. Cases 2 and 3 had GAS isolated from blood culture. Case 2 was fatal. Pharyngeal culture survey of the family members and schoolchildren was conducted. Antibiogram, serotyping, detection of exotoxin genes, and random amplified polymorphic DNA patterns of the disease strains and survey strains were examined. RESULTS: One of 15 family members sampled-the sister of the index case-and 7 (5.6%) of 125 schoolchildren sampled had GAS isolated from pharyngeal cultures. Of the 10 strains examined, 2 isolates from the patients, 1 from the sister of index case, and 2 from the classmates of case 2 (the fatal case) had an identical pattern of both genotype and phenotype. CONCLUSION: We describe a family cluster of STSS involving 3 children caused by a single clone and provide additional data regarding invasive GAS infection subsequent to household contact. Additional studies should be conducted in conjunction with surveillance to define better the magnitude of risk in household contacts and to identify settings in which subsequent infections may occur.

Child↗

Acute lupus pneumonitis mimicking pulmonary tuberculosis: a case report.

We report a case of systemic lupus erythematosus in a 15-year-old girl with initial presentation as acute lupus pneumonitis. A fulminant course with pancytopenia and respiratory distress were developed 3 weeks after symptom onset. Chest radiographs revealed an interstitial pattern with miliary nodules over bilateral lower lung fields that mimics miliary tuberculosis. The patient was treated with intravenous immunoglobulin and antituberculosis drugs because the infection-associated hemophagocytic syndrome and pulmonary tuberculosis could not be excluded from the clinical course. The response to antituberculosis treatment, however, was poor and her respiratory condition deteriorated rapidly to impending respiratory failure 1 week after admission. Systemic lupus erythematosus with acute lupus pneumonitis was then diagnosed based on the fulminant clinical course and accordant laboratory results. Corticosteroid (methylprednisolone) and cytotoxic agent (cyclophosphamide) pulse therapies were applied twice and once, respectively. She recovered gradually after receiving the immunotherapy.

Acute Disease↗

Childhood and adolescent tuberculosis in northern Taiwan: an institutional experience during 1994-1999.

UNLABELLED: This study evaluated the clinical characteristics of childhood and adolescent tuberculosis (TB) at the end of the twentieth century in a referral children's hospital in northern Taiwan. The hospital charts were reviewed retrospectively of children/adolescents aged less than 18 y who were seen in a children's hospital in northern Taiwan between 1994 and 1999 and diagnosed with TB. A total of 62 individuals was diagnosed during this period. The patients' demographic data, presenting symptoms, clinical features, bacteriological results, drug susceptibility and tuberculin skin-test results were analysed. Most diagnosed cases lay in one of two main age ranges, younger than 5 y and adolescents. The presenting symptoms of study subjects were typically non-specific. Bone involvement occurred for 21 patients (33.9%) and was the most common extrapulmonary manifestation. Mycobacterium tuberculosis was isolated from 47 patients (75.8%). Five isolates were resistant to pyrazinamide, three to streptomycin and one to isoniazid, but no multidrug resistant isolates of TB were detected from culture-proven cases. Seventeen of 47 (36.2%) culture-proven patients revealed negative acid-fast staining initially but, subsequently, M. tuberculosis was isolated from various clinical specimens using a standard method at a later date. The tuberculin skin test was positive for 24 of 32 patients (75%) who received such an examination. CONCLUSION: Extrathoracic TB was more common in children below 5 y of age than their adolescent counterparts, and chiefly involved the peripheral long bones. The potential drug resistance of M. tuberculosis in childhood and adolescent TB did not appear to have been a major problem in northern Taiwan before the year 2000.

Adolescent↗

Duration of enterovirus shedding in stool.

Excretion of enterovirus (EV) may persist for months after an EV infection; the exact duration of excretion, however, is not yet known. Twelve children who were infected with EV between September 1998 and June 1999 were enrolled into this study. The patients included 4 boys and 8 girls, aged from 1 month to 5 years. Six patients were asked to join this virus isolation program, and the other 6 were followed-up regularly. Only 2 of the patients were infected with EV 71. To delineate the duration of EV shedding in each case, throat swabs for virus isolation were performed every 1 or 2 weeks for at least 1 month, and stools were analyzed for at least 2 months following the same schedule. After the infection, EV was identifiable in the throat in 4 patients for 1 to 2 weeks. Excretion of EV through stool was evidenced for up to 7 weeks in 6 patients, 8 weeks in 3, and 11 weeks in 1. In the 2 patients who failed to show up for follow-up visits from the 7th week, excretion of EV through stool was recorded for at least 7 weeks. Different serotypes of EV could be isolated from the same patient who was not experiencing febrile illness in 2 instances in a series of virus cultures. Coexistence of vaccine poliovirus and non-polio EV, both isolated from stool, was evidenced in 2 patients. Results from this study suggest that EV may not be identified from the throat 2 weeks after the infection, but its excretion through stool can persist for up to 11 weeks. This study also demonstrated that subclinical EV coinfection could occur, and that live vaccine poliovirus did not interfere with the invasion of other non-polio EV.

Child, Preschool↗

Characteristics of group A streptococcal bacteremia with comparison between children and adults.

This retrospective study aimed to compare the characteristics of group A streptococcal bacteremia in children and adults. A total of 76 (12 children and 64 adults) patients with group A streptococcal bacteremia treated from October 1995 through September 2000 at the Linko Chang Gung Memorial Hospital were included. The mean age was 47.6 years (range, 12 days-90 years). Forty-four (57.9%) patients had predisposing medical conditions. Malignant cancer (23.7%) and diabetes (22.4%) were the 2 most common conditions, which occurred only in adults. Two (16.7%) children had chickenpox associated with secondary group A streptococcal bacteremia. Skin and soft tissue infection (60.5%) was the most common clinical manifestation. The mortality rate related to group A streptococcal bacteremia was 25%. Twelve patients met the criteria of streptococcal toxic shock syndrome and 6 (50%) were children (p<0.05). Despite immediate and aggressive treatment, mortality due to streptococcal toxic shock syndrome was 66.7%. The incidence of streptococcal toxic shock syndrome was much higher in children (50%) than in adults (9.4%). Early diagnosis of invasive group A streptococcal infections and streptococcal toxic shock syndrome requires awareness of the presentations and a high level of suspicion. For fulminant group A streptococcal infection, a combination of a beta-lactam antibiotic plus clindamycin and/or adjuvant therapy with intravenous immunoglobulin is recommended.

Adolescent↗

Deep neck infections in children.

From December 1989 through 1998, a total of 68 children with deep neck infection were enrolled into this study. The mean age was 5.9 years (range, 1 month-15.8 years). Infections in the retropharyngeal space (36.7%) were most common, followed by parapharyngeal space (30.8%), peritonsillar space (20.6%), and submandibular space (11.9%). Fever, neck pain, and swelling were the most frequent symptoms. The most common pathogens were viridans streptococci (41%, 16/39) and Staphylococcus aureus (26%, 10/39). Other isolates included Prevotella spp., Veillonella spp., Klebsiella pneumoniae, Escherichia coli, Morganella spp., and Enterobacter spp. Mixed infection was found in 46% (18/39) of patients. The mean duration of hospitalization was 12.4 days (range, 2-45 days). Complete resolution was achieved in 61 (89.7%) children. Complications occurred in 7 patients, including recurrence, mediastinal spread, bacteremia, and suppurative thyroiditis; the patient with mediastinal spread plus bacteremia died. Five patients had congenital cyst and 4 of them had complications or recurrence/relapse. In conclusion, infections in the retropharyngeal space and polymicrobial infections were most common in deep neck infection of Taiwan children.

Anti-Bacterial Agents↗

Expression of capsid [correction of caspid] protein VP1 for use as antigen for the diagnosis of enterovirus 71 infection.

To produce enterovirus 71 antigen for diagnostic purposes, the gene encoding the entire capsid protein VP1 was amplified by reverse transcription-polymerase chain reaction (RT-PCR), cloned and expressed in Escherichia coli as a poly-histidine fusion protein. Western blotting experiments with sera from patients with enterovirus 71 infection indicated that immunoglobulin G (IgG) and IgM antibodies bound to a single polypeptide VP1. According to these results, IgM anti-VP1 appeared in sera of patients with a symptomatic enterovirus 71 acute infection, whereas IgG anti-VP1 was present in sera of past infection. This finding suggests that detecting IgG and IgM immune responses against linear epitopes of recombinant VP1 is an effective means of determining the different phases of enterovirus 71 infection. In addition, sera containing coxsackie virus 16 (CA16) antibodies did not cross-react with the recombinant VP1 of enterovirus 71, despite the homology between VP1 proteins of both viruses. Comparison with reference PCR and neutralization assays showed these antibody tests to be appropriate for the serodiagnosis of enterovirus 71 infection.

Antibodies, Viral↗

Necrotising pneumonitis in children.

UNLABELLED: We retrospectively analysed the clinical features and outcome of children under 17 years of age with necrotising pneumonitis (NP). The radiographs and CT scans of the chest of children under 17 years of age between July 1995 and March 1999 who had complicating community-acquired pneumonia were reviewed. CT scans were obtained for persistent fever, respiratory distress and sepsis despite empiric antibiotic therapy and closed tube drainage. A total of 21 children had the radiographic features of NP of whom 11 (52%) patients were successfully managed using antibiotic therapy with or without closed tube drainage. Ten patients required thoracoscopic decortications and/or lysis of pleural adhesions or debridement of empyema due to refractory pleural sepsis, failure of pulmonary re-expansion and persistent air-leaks. The most common pathogens identified were Streptococcus pneumoniae (n = 3), Staphylococcus aureus (n = 2), and Haemophilus influenzae type b (n = 2). The days of hospital stay, duration of fever and days of C-reactive protein return to normal were significantly less for the medically versus the surgically treated children (P < 0.05). CONCLUSION: The clinical course of necrotising pneumonitis in children following complicated pneumonia is often prolonged despite adequate antibiotic therapy. Necrotising pneumonitis with co-existing multiple loculations, pneumothorax/ bronchopleural fistula in the empyema and extensive pleural peel are poor prognostic factors for medical therapy. Thoracoscopic removal of loculated empyema, lysis of adhesions and/or decortication are effective in relieving tachypnoea, chest pain, and controlling fever and improve the outcome, especially in children with empyema.

Adolescent↗

Transarterial embolisation of complex cavernous sinus dural arteriovenous fistulae with low-concentration cyanoacrylate.

We report the effectiveness of low-concentration n-butyl-2-cyanoacrylate (NBCA)-Lipiodol-tungsten mixture (10-15 %) in the management of patients with aggressive or recurrent complex cavernous dural arteriovenous fistulae (CSDAVF). We treated five patients with complex CSDAVF with a low concentration of an NBCA-Lipiodol-tungsten mixture after catheterisation of the feeding arteries arising from the external carotid artery. Three had a recurrent CSDAVF after transarterial particulate embolisation. Three refused transvenous treatment or could not be treated in this way; two patients had also feeding dural branches of the internal carotid artery. All patients had complete resolution of symptoms and signs within a month of the procedure. No definite neurological complication was found during follow-up ranging from 12 to 36 months. Transarterial embolisation with low-concentration cyanoacrylate appears to be an effective alternative management of aggressive or recurrent CSDAVF.

Arteriovenous Fistula↗

Relationship between serotypes and genotypes based on the hypervariable region of the S1 gene of infectious bronchitis virus.

To group infectious bronchitis virus (IBV) isolates, a genetic grouping method based on hypervariable region 1 (HVR 1, nucleotides 168 to 197) was compared with that based on the whole S1 gene. Both methods resulted in the same grouping data. So the grouping method based on HVR 1 could represent the grouping method based on the whole S1 gene. Taiwan isolates could not be placed within the existing groups. In order to test the correlation between genotype and serotype, a one-way neutralization test was used to compare 9 Taiwan isolates selected from different genotypes with Massachusetts (Mass) (H120) and Connecticut (Conn) standard strains. In addition, a two-way cross-neutralization test was performed in embryonated eggs with the beta method (constant-virus, diluted-serum) and the reciprocal neutralization titers were calculated to give the relatedness (r) values. The results of two kinds of neutralizing tests showed that the serotypes of 9 isolates were different from Mass or Conn. Based on the r-values, 9 isolates were divided into two serotypes which were correlated with their genotypes. From pathogenicity tests, IBV Taiwan isolates could be divided into high, intermediate, and low pathogenicity according to their pathogenicity indexes. However, no relationship exists between pathotype and genotype. In conclusion, the genetic typing method based on HVR 1 can be used for typing IBV isolates.

Animals↗

Lipid solubility of vasodilatory vanilloid-type beta-blockers on the functional and binding activities of beta-adrenoceptor subtypes.

Various vanilloid-type beta-adrenoceptor blockers were studied on guinea pig right atrium and trachea and rat colon. In addition, we also investigated their beta(1)-, beta(2)-, and beta(3)-adrenoceptor binding affinities. All these beta-adrenergic antagonists inhibited (-)isoproterenol-induced positive chronotropic effects of the right atrium and tracheal relaxation responses in a concentration-dependent manner. Some of these agents prevented the inhibition of rat colon spontaneous motility by (-)isoproterenol. Of the agents tested, we found that ferulidilol, eugenodilol, eugenolol, isoeugenolol, and ferulinolol, as well as propranolol and metoprolol, possessed beta(3)-adrenoceptor blocking activities, others were nearly without effectiveness. Furthermore, the binding characteristics of vanilloid-type beta-adrenergic antagonists were evaluated in [3H]CGP-12177, a beta(1)/beta(2)-adrenoceptor blocker and a beta(3)-adrenoceptor agonist, binding to beta(1)-, beta(2)-, and beta(3)-adrenoceptor sites in rat ventricle, lung, and interscapular brown adipose tissue (IBAT) membranes, respectively. Eugenodilol, eugenolol, metoprolol, isoeugenolol, and ferulinolol were less potent than both propranolol and ferulidilol in competing for the beta(3)-adrenoceptor binding sites. From the results of in vitro functional and binding studies, we suggested that propranolol, ferulidilol, eugenodilol, eugenolol, metoprolol, isoeugenolol, and ferulinolol all possessed beta(3)-adrenoceptor blocking activities. On the other hand, we also found that eugenodilol, eugenolol, metoprolol, isoeugenolol, and ferulinolol had a low lipid solubility in comparison with propranolol and ferulidilol. In conclusion, we proposed that beta(3)-adrenoceptor antagonistic actions of these vanilloid-type beta-blockers were positively correlated with their lipid solubility.

Adrenergic beta-Agonists↗

Candidaemia in special care nurseries: comparison of albicans and parapsilosis infection.

OBJECTIVES: Candidaemia caused by Candida parapsilosis (CP) is being increasingly reported among infants in neonatal intensive care units (NICU). To assess relative severity, clinical manifestations of candidaemia caused by C. albicans (CA) and CP in a NICU were compared. METHODS: Between January 1994 and July 1997, episodes of candidaemia occurring among infants hospitalized in the NICU were identified in a children's hospital. The demographic characteristics, associated risk factors, clinical manifestations and outcome of the infants with CP fungaemia were collected and compared with those of the infants with CA fungaemia. RESULTS: Twenty-four episodes caused by CA and 22 episodes caused by CP were included in this study. No significant differences were found between the two groups for gestational age, birth weight, male gender, post-natal age at onset of candidaemia, frequency of antecedent neonatal events, prior duration of antibiotic therapy and hyperalimentation, as well as presence of central venous catheter (CVC). Infants with CA fungaemia were significantly more likely than those with CP fungaemia to present with hypoxaemia, bradycardia and respiratory distress requiring intubation, and have a longer prior duration of indwelling CVC and a higher dissemination rate. The eradication rate of candidaemia and overall case fatality rate were comparable in both groups. but CP fungaemia did not appear to cause acute lethal events. CONCLUSION: The presenting signs of CP fungaemia are relatively not so severe, but CP fungaemia, which is relatively difficult to eradicate, increases the morbidity and mortality of the infants.

Blood↗

Nutritional status of mechanically ventilated critically ill patients: comparison of different types of nutritional support.

Malnutrition is a common problem in hospitalized patients. Early assessment of nutritional status may help in identifying patients for whom nutritional interventions are needed. The purpose of this study was to assess and compare the nutritional status of mechanically ventilated critically ill patients who were receiving nutritional support. Forty-nine patients were divided into either enteral nutrition, total parenteral nutrition or combined (enteral plus total parenteral nutrition) groups. Anthropometric and biochemical measurements, and medical status (APACHE II score) were assessed at the 1st day and 14th day of admission in the intensive care unit (ICU) of Taichung Veteran General Hospital. The length of ventilator dependency was significantly positively correlated with calorie and carbohydrate intake in the pooled group. Patients receiving enteral and combined nutrition showed significantly lower anthropometric measurements at the 14th day after admission. Patients in all groups had abnormal mean biochemical values at the 1st day of admission. Subjects in the combined group showed a significant increase in prealbumin and the Maastricht Index levels after 14 days. Patients in all three groups were malnourished when admitted to the ICU. Patients showed a slightly improvement of nutritional status after receiving nutritional support for 14 days.

APACHE↗

Fluconazole therapy in neonatal candidemia.

We reviewed 62 episodes (from 59 infants) of neonatal candidemia that occurred between January 1994 and June 1999. Except 5 term babies, all infants were premature (median gestational age [GA], 30 weeks) and birth weight was less than 2,500 g (median, 1,300 g). Most infants had reported risk factors and other neonatal problems. The age at onset of candidemia ranged from 15 to 173 days with a median of 34 days. In addition to catheter removal, all but one infants received antifungal agents and candidemia was eradicated subsequently in 46 episodes (75%). Eighteen infants with 19 episodes ever received fluconazole therapy. Fluconazole was administered as the first line agent in 6 episodes and successfully cleared candidemia in 5 episodes. Fluconazole was used as an alternative agent in an additional 13 episodes after amphotericin B (am B) +/- flucytosine were given for a period without a satisfactory result and eradication of candidemia was achieved in 8 episodes subsequently. All 18 infants tolerated fluconazole well and no withdrawal was required on account of its adverse effect. In contrast, am B alone was administered as the first line agent in 55 episodes and successfully cleared candidemia in 32 episodes (58%). This retrospective analysis suggests that fluconazole appears to be safe in neonates and can be used as an alternative agent in treating neonatal candidemia. A large-scaled prospective study may be needed.

Antifungal Agents↗

Vanidipinedilol: a vanilloid-based beta-adrenoceptor blocker displaying calcium entry blocking and vasorelaxant activities.

Calcium channel and beta-adrenoceptor blockade have proved highly useful in antihypertensive therapy. Studies of the mechanisms of action of vanidipinedilol that combine these effects within a single molecule are described here. Intravenous injection of vanidipinedilol (0.1, 0.25, 0.5, 1.0, and 2.0 mg/kg) produced dose-dependent hypotensive and bradycardic responses, significantly different from nifedipine-induced (0.5 mg/kg, i.v.) hypotensive and reflex tachycardic effects in pentobarbital-anesthetized Wistar rats. A single oral administration of vanidipinedilol at doses of 10, 25, and 50 mg/kg dose-dependently reduced blood pressure with a decrease in heart rate in conscious spontaneously hypertensive rats (SHRs). In the isolated Wistar rat atrium, vanidipinedilol (10(-7), 10(-6), and 10(-5) M) competitively antagonized the (-)isoproterenol-induced positive chronotropic and inotropic effects and inhibited the increase in heart rate induced by Ca2+ (3.0-9.0 mM) in a concentration-dependent manner. The parallel shift to the right of the concentration-response curve of (-)isoproterenol and CaCl2 suggested that vanidipinedilol possessed beta-adrenoceptor-blocking and calcium entry-blocking activities. On tracheal strips of reserpinized guinea pig, cumulative doses of vanidipinedilol (10(-10) to 3x10(-6) M) produced dose-dependent relaxant responses. Preincubating the preparation with ICI 118,551 (10(-10), 10(-9), 10(-8) M), a beta2-adrenoceptor antagonist, shifted the vanidipinedilol concentration-relaxation curve significantly to a region of higher concentrations. These results implied that vanidipinedilol had a partial beta2-agonist activity. In the isolated thoracic aorta of rat, vanidipinedilol had a potent effect inhibiting high-K+-induced contractions. KCI-induced intracellular calcium changes of blood vessel smooth muscle cell (A7r5 cell lines) determined by laser cytometry also was decreased after administration of vanidipinedilol (10(-8), 10(-7), 10(-6) M). Furthermore, the binding characteristics of vanidipinedilol and various antagonists were evaluated in [3H]CGP-12177 binding to ventricle and lung and [3H]nitrendipine binding to cerebral cortex membranes in rats. The order of potency of beta1- and beta2-adrenoceptor antagonist activity against [3H]CGP-12177 binding was (-)propranolol (pKi, 8.59 for beta1 and 8.09 for beta2) > vanidipinedilol (pKi, 7.09 for beta1 and 6.64 for beta2) > atenolol (pKi, 6.58 for beta1 and 5.12 for beta2). The order of potency of calcium channel antagonist activity against [3H]nitrendipine binding was nifedipine (pKi, 9.36) > vanidipinedilol (pKi, 8.07). The ratio of beta1-adrenergic-blocking/calcium entry-blocking selectivity is 0.1 and indicated that vanidipinedilol revealed more in calcium entry-blocking than in beta-adrenergic-blocking activities. It has been suggested that vanidipinedilol-induced smooth muscle relaxation may involve decreased entry of Ca2+ and partial beta2-agonist activities. In conclusion, vanidipinedilol is a nonselective beta-adrenoceptor antagonist with calcium channel blocking and partial beta2-agonist associated vasorelaxant and tracheal relaxant activities. Particularly, the vasodilator effects of vanidipinedilol are attributed to a synergism of its calcium entry blocking and partial beta2-agonist activities in the blood vessel. A sustained bradycardic effect results from beta-adrenoceptor blocking and calcium entry blocking, which blunts the sympathetic activation-associated reflex tachycardia in the heart.

Adrenergic beta-1 Receptor Antagonists↗