Biomedical subjects

W C Ko

Publications and source records attributed to W C Ko.

At least 37 records · Page 2Linked to original sources

PubMed2000

Comparison of the MB/BacT and BACTEC MGIT 960 system for recovery of mycobacteria from clinical specimens.

A total of 543 specimens were cultured in parallel with the MB/BacT and BACTEC MGIT 960 systems and on the conventional solid media. Mycobacteria were identified from 95 (17.5%) specimens, including 63 (66.3%) Mycobacterium tuberculosis and 32 (33.7%) nontuberculous mycobacteria. The recovery rates for the MB/BacT, MGIT 960, and solid media were 91.6, 87.4, and 54.7%, respectively, for all mycobacteria; the recovery rates were 93.6, 88.9, and 63.4%, respectively, for M. tuberculosis complex alone, and 87.5, 84.4, and 37.5%, respectively, for all nontuberculous mycobacteria. The mean times to detection of all mycobacteria by individual systems were 13. 9, 8.7, 31.7 days for the MB/BacT, MGIT 960 and solid media, respectively, 13.9, 9.3, 32.9 days for M. tuberculosis alone, and 14. 1, 8.1, 27.2 days for all nontuberculous mycobacteria. The contamination rates of the MB/BacT and MGIT 960 were 10.2 and 5.4%, respectively. With regard to detection times and recovery rates, both automated systems are superior to the conventional media (all p < 0.005). As compared to the MB/BacT, the MGIT 960 detected mycobacterial growth more rapidly (p < 0.001), and had a lower contamination rate (p = 0.003); however, there was no statistically significant difference in recovery rates between these two systems. These results indicate that both MGIT 960 and MB/BacT systems are rapid, sensitive, and efficient methods for the recovery of mycobacteria from clinical specimens.

Humans↗

PubMed2000

Clinical features and therapeutic implications of 104 episodes of monomicrobial Aeromonas bacteraemia.

OBJECTIVES: Aeromonas bacteraemia is not a common infectious disease, but can cause a grave outcome in infected cases. In this study, clinical presentations and prognostic factors of cases of monomicrobial Aeromonas bacteraemia were analysed. Also, the impact of beta-lactam and aminoglycoside in combination and of emerging cephalosporin-resistance during therapy was discussed. METHODS: From 1989 to 1998 in a medical centre in southern Taiwan, those cases with monomicrobial Aeromonas bacteraemia were included for study. RESULTS: A total of 104 episodes of monomicrobial Aeromonas bacteraemia, accounting for 74% of all Aeromonas bacteraemia, were encountered. The infections usually occurred in the patients with hepatic cirrhosis (54%) or malignancy (21%) and were community-acquired (74%). Cases of community-acquired bacteraemia were more likely to have cirrhosis, a high severity score at onset, and a worse prognosis than those of nosocomial bacteraemia did and nosocomial isolates were less susceptible to cefoxitin and cefotaxime. Forty-three percent of cases had a concomitant infection focus, such as primary peritonitis, invasive cellulitis or necrotizing fasciitis, biliary tract or burn wound infections. Crude fatality rate within 2 weeks after the onset was 30%. Secondary bacteraemia and a higher severity score ( > or = 4) for illness at the first presentation were independently associated with a fatal outcome. The therapeutic superiority of beta-lactam and aminoglycoside in combination cannot be demonstrated in patients with Aeromonas bacteraemia. Cefotaxime resistance emerged in 3.4% of 58 patients treated with a cephalosporin for at least 72 h. None of the community-acquired isolates, but one-quarter of the nosocomial isolates, were resistant to cefotaxime. CONCLUSIONS: Aeromonas bacteraemia usually occurred in patients with liver cirrhosis or malignancy, and heralded a poor prognosis, especially while associated with a relevant infectious source or with a higher severity score at presentation. The superiority of aminoglycoside and beta-lactam in combination cannot be demonstrated while treating those patients, and the emergence of antimicrobial resistance to cephalosporin was a rare event during cephalosporin therapy. Thus, a broad-spectrum cephalosporin remains one of the antimicrobial alternatives for invasive community-acquired Aeromonas infections.

Adolescent↗

PubMed2000

Relaxant effects of petasins in isolated guinea pig trachea and their structure-activity relationships.

In the present study, we attempted to compare four petasins, isolated from Petasites formosanus Kitamura, and to look for structure-activity relationships, which may be helpful for synthesizing more active compounds for the treatment of asthma. Four petasins, including petasin, isopetasin, S-petasin and S-isopetasin, concentration-dependently relaxed histamine (10 microM)-, carbachol (0.2 microM)-, KCl (30 mM)-, and leukotriene D4 (10 nM)-induced precontractions of isolated guinea pig trachealis. The IC50 values strongly showed that the relaxant effects of the sulfur-containing petasins, S-petasin and S-isopetasin, were more potent than those of non-sulfur-containing petasins, petasin and isopetasin. S-isopetasin, with IC50 values around 10 microM, selectively relaxed carbachol- and KCl-induced precontractions, and had almost no effects (IC50s > 300 microM) on histamine- and leukotriene D4-induced precontractions. However, S-petasin, with IC50 values about 6-9 microM, non-selectively relaxed the precontractions induced by all these contractile agents. The influence of isomerization of either petasin to isopetasin or S-petasin to S-isopetasin on the relaxant effects is not clear.

Animals↗

PubMed2000

Epidemiology of ciprofloxacin resistance and its relationship to extended-spectrum beta-lactamase production in Klebsiella pneumoniae isolates causing bacteremia.

A prospective study of Klebsiella pneumoniae bacteremia was performed in 12 hospitals in 7 countries. Of 452 episodes of bacteremia, 25 (5.5%) were caused by K. pneumoniae that was resistant in vitro to ciprofloxacin. Extended-spectrum beta-lactamase (ESBL) production was detected in 15 (60%) of 25 ciprofloxacin-resistant isolates, compared with 68 (16%) of 427 ciprofloxacin-susceptible strains (P=.0001). Multivariate analysis revealed that risk factors for ciprofloxacin resistance in K. pneumoniae included prior receipt of a quinolone (P=.0065) and an ESBL-producing strain (P=.012). In all, 18% of ESBL-producing isolates were also ciprofloxacin-resistant. Pulsed-field gel electrophoresis showed that 11 of the 15 ciprofloxacin-resistant ESBL-producing strains belonged to just 4 genotypes, suggesting that patient-to-patient transmission of such strains occurred. The close relationship between ESBL production and ciprofloxacin resistance is particularly worrisome because the first reported instance of plasmid-mediated ciprofloxacin resistance has been in an isolate of K. pneumoniae also possessing an ESBL.

Anti-Infective Agents↗

PubMed2000

Dissemination of CTX-M-3 and CMY-2 beta-lactamases among clinical isolates of Escherichia coli in southern Taiwan.

A total of 1,210 clinical isolates of Escherichia coli collected from a university hospital in southern Taiwan were screened for production of extended-spectrum beta-lactamases (ESBLs). Expression of classical ESBLs (resistant to extended-spectrum beta-lactam agents and susceptible to beta-lactam inhibitors) was inferred in 18 isolates by the phenotypic confirmatory test. These included 10 isolates producing CTX-M-3, 2 strains carrying SHV-12, 1 strain harboring SHV-5, 1 strain expressing TEM-10, and 4 strains producing unidentifiable ESBLs with a pI of 8.05, 8.0, or 7.4. Eighteen isolates that showed decreased susceptibilities to ceftazidime and/or cefotaxime, negative results for the confirmatory test, and high-level resistance to cefoxitin (MICs of >/=128 microg/ml) were also investigated. Five isolates were found to produce CMY-2 AmpC enzymes, one isolate carried both CTX-M-3 and CMY-2, and the remaining three and nine isolates expressed putative AmpC beta-lactamases with pIs of >9.0 and 8.9, respectively. Thus, together with the isolate producing CTX-M-3 and CMY-2, 19 (1.6%) isolates produced classical ESBLs. Pulsed-field gel electrophoresis revealed that all isolates carrying CTX-M-3 and/or CMY-2 were genetically unrelated, indicating that dissemination of resistance plasmids was responsible for the spread of these two enzymes among E. coli in this area. Among the 16 isolates expressing CTX-M-3 and/or CMY-2, 5 might have colonized outside the hospital environment. Our data indicate that CTX-M-3 and CMY-2, two beta-lactamases initially identified in Europe, have been disseminated to and are prevalent in Taiwan.

Adult↗

PubMed2000

Involvement of protein kinase C-gamma in IL-1beta-induced cyclooxygenase-2 expression in human pulmonary epithelial cells.

The signaling pathway of protein kinase C (PKC) is known to play a role in mediating the action of various cytokines. Here we examined the signal transduction pathway of PKC activation and the role of PKC isoforms in interleukin-1beta (IL-1beta)-mediated cyclooxygenase-2 (COX-2) expression in human pulmonary epithelial cell line (A549). The tyrosine kinase inhibitors (genistein and tyrphostin AG126) and phosphatidylcholine-phospholipase C inhibitor (D-609) prevented IL-1beta-induced prostaglandin E(2) (PGE(2)) release and COX-2 expression, whereas U-73122 (a phosphatidylinositol-phospholipase C inhibitor) and propranolol (a phosphatidate phosphohydrolase inhibitor) had no effect. The PKC inhibitors (Go 6976 and Ro 31-8220) and NF-kappaB inhibitor, pyrrolidine dithiocarbamate, also attenuated IL-1beta-induced PGE(2) release and COX-2 expression. Western blot analysis using PKC isoenzyme-specific antibodies indicated that A549 cells expressed PKC-alpha, -gamma, -iota, -lambda, -zeta, and -micro. IL-1beta caused the translocation of PKC-gamma but not other isoforms from cytosol to the membrane fraction. Moreover, the translocation of PKC-gamma was inhibited by genistein or D-609, but not by U-73122. IL-1beta caused the translocation of p65 NF-kappaB from cytosol to the nucleus as well as the degradation of IkappaB-alpha in cytosol. Furthermore, the translocation of p65 NF-kappaB was inhibited by genistein, Go 6976, Ro 31-8220, or pyrrolidine dithiocarbamate. These results indicate that in human pulmonary epithelial cells, IL-1beta might activate phosphatidylcholine-phospholipase C through an upstream tyrosine phosphorylation to elicit PKC activation, which in turn initiates NF-kappaB activation, and finally induces COX-2 expression and PGE(2) release. Of the PKC isoforms present in A549 cells, only activation of PKC-gamma is involved in regulating IL-1beta-induced responses.

Cyclooxygenase 2↗

PubMed2000

Seroprevalence of Coxiella burnetii infection in southern Taiwan.

BACKGROUND AND PURPOSE: The emergence of infection with Coxiella burnetii, the causative organism of Q fever, has been only recently recognized in Taiwan. Several cases of acute Q fever infection have been described, but the prevalence of antibodies to C. burnetii in the general population in Taiwan has not been reported. Thus, we studied the seroprevalence of C. burnetii infection in southern Taiwan. METHODS: We conducted a retrospective serosurvey to examine the prevalence of C. burnetii infection among subjects admitted to a rural hospital in Taiwan for various reasons, and among presumably healthy attendees of a routine physical examination clinic of an urban public hospital. The diagnosis of C. burnetii infection required the presence of antibodies to both phase I and II antigens (titer > or = 1:16) or only to phase II antigens (titer > or = 1:256), as detected by indirect immunofluorescence assay. RESULTS: The prevalence of C. burnetii infection was 4.2% in both the in-patient (15/357) and physical examination participant (11/259) populations. None of these subjects had signs compatible with acute Q fever (febrile illness within the past 3 months). The antibody prevalence rate was higher in males than in females, and peaked in persons aged 61 to 70 years. CONCLUSIONS: These data suggest that C. burnetii infection is not rare in southern Taiwan and does not cause clinical symptoms in all infected patients.

Adolescent↗

PubMed2000

Arcobacter butzleri bacteremia in a patient with liver cirrhosis.

Invasive Arcobacter butzleri infection in humans has been rarely described. We report a 60-year-old man with liver cirrhosis who presented with high fever and esophageal variceal bleeding. Two aerobic blood cultures grew Campylobacter-like organisms. The biochemical reactions of the isolate were inconclusive, while sequence analysis of the 16S rRNA gene definitively identified the organism as A. butzleri. The patient's bleeding stopped after endoscopic sclerosing therapy. Although the organism appeared to be resistant to cephalosporins on the basis of the minimum inhibitory concentrations determined with the E test, the fever resolved with parenteral cefuroxime. Whether the clinical improvement was related to cephalosporin therapy or to the self-limited nature of Arcobacter bacteremia is not known.

Arcobacter↗

PubMed2000

Mechanisms involved in the antiplatelet activity of Staphylococcus aureus lipoteichoic acid in human platelets.

In this study, gram-positive Staphylococcus aureus lipoteichoic acid (LTA) dose-dependently (0.1-1.0 microg/ml) and time-dependently (10-60 min) inhibited platelet aggregation in human platelets stimulated by agonists. LTA also dose-dependently inhibited phosphoinositide breakdown and intracellular Ca+2 mobilization in human platelets stimulated by collagen. LTA (0.5 and 1.0 microg/ml) also significantly inhibited thromboxane A2 formation stimulated by collagen in human platelets. Moreover, LTA (0.1-1.0 microg/ml) dose-dependently decreased the fluorescence of platelet membranes tagged with diphenylhexatrience. Rapid phosphorylation of a platelet protein of Mr. 47,000 (P47), a marker of protein kinase C activation, was triggered by PDBu (30 nM). This phosphorylation was markedly inhibited by LTA (0.5 and 1.0 microg/ml) within a 10-min incubation period. These results indicate that the antiplatelet activity of LTA may be involved in the following pathways: LTA's effects may initially be due to induction of conformational changes in the platelet membrane, leading to a change in the activity of phospholipase C, and subsequent inhibition of phosphoinositide breakdown and thromboxane A2 formation, thereby leading to inhibition of both intracellular Ca+2 mobilization and phosphorylation of P47 protein. Therefore, LTA-mediated alteration of platelet function may contribute to bleeding diathesis in gram-positive septicemic and endotoxemic patients.

Calcium Signaling↗

PubMed2000

Tetanus of the elderly.

The medical records of 20 tetanus patients who were treated at a university teaching hospital in Taiwan during the period from October 1991 to July 1999 were retrospectively analyzed. There were 18 adults (six males and 12 females) with unknown previous immunization status and ages ranging from 34 to 87 years old (mean 63 years). Two patients were children, aged 3 and 5 years old, respectively; both of them had incomplete tetanus immunization. Of the 17 patients reporting previous acute injury, 10 had tetanus-prone wounds. Four of six patients who sought medical help for wound management received tetanus toxoid, but none received tetanus immunoglobulins. The most common symptoms were trismus, dysphagia, and muscular rigidity. Specific treatment consisted of active and passive immunization, wound management, parenteral antibiotics, and benzodiazepines, muscle relaxants or neuromuscular blockades for control of spasms and sedation. All adults were admitted to the intensive care unit and an artificial airway was established. Fourteen of them required ventilator support during the illness. Prophylactic tracheostomy was performed within 24 h after arrival in 12 (92%) of 13 patients. Two patients died with an overall mortality rate of 10%. Sequelae were rare in the patients who survived. Because of inclusion of the diphtheria-pertussis-tetanus (DPT) vaccine in the national Children's Vaccine Program and improvement in obstetrical practices and neonatal care in Taiwan, tetanus mainly occurs in people older than 65 years instead of neonates or children. Waning immunity to tetanus in the elderly and poor wound management practices by primary care physicians were contributory factors.

Adult↗

PubMed1999

Triflavin potentiates the antiplatelet activity of platelet activating factor receptor antagonist on activated neutrophil-induced platelet aggregation.

In this study, specific platelet activating factor (PAF) receptor antagonist ginkgolide B (BN52021) was tested for its antiplatelet activity in zymosan activated polymorphonuclear neutrophil-induced platelet aggregation. Triflavin was also tested for its antiplatelet activity compared with PAF receptor antagonist. Triflavin, an Arg-Gly-Asp-containing disintegrin purified from venom peptide inhibited platelet aggregation by interfering with the interaction of fibrinogen with the glycoprotein IIb/IIIa complex. Furthermore, we also report an efficient high resolution method for quantitative analysis of PAF using high-performance capillary electrophoresis (HPCE). The supernatant of polymorphonuclear neutrophils after their activation by opsonized zymosan induces the aggregation of washed rabbit platelets. In rabbit platelets, BN52021 (100-1000 microM) only partially inhibited activated polymorphonuclear neutrophil-induced platelet aggregation, and its maximal inhibition was estimated to be about 79%. Triflavin also partially inhibited platelet aggregation about 82% induced by activated polymorphonuclear neutrophils. Furthermore, after treatment with a combination of triflavin (0.26 microM) with various concentrations of BN52021 (4-1000 microM), the inhibitory effect of platelet aggregation was almost completely. This inhibition was greater than that produced by the individual drugs alone. These results indicate that a combination of glycoprotein IIb/IIIa complex and PAF receptor antagonist could completely inhibit activated polymorphonuclear neutrophil-induced platelet aggregation. In addition, the amount of PAF released from zymosan (6 mg/ml)-activated polymorphonuclear neutrophils was accurately calculated about 11.8+/-1.5 ng/10(6) cells, and did not further increase even at a high concentration of zymosan (10 mg/ml). These results suggest that PAF play a major role in the interaction between platelets and polymorphonuclear neutrophils. This interaction may be important in the pathogenesis of thrombosis and inflammatory diseases. Our present findings support the hypothesis that combination therapy with glycoprotein IIb/IIIa complex antagonists and PAF receptor antagonists may represent a new approach to the treatment of ischemic disorders.

Animals↗

PubMed1999

Epstein-Barr virus-containing T-cell lymphoma and atherosclerotic abdominal aortic aneurysm in a young adult.

Malignant lymphoma infiltrating the abdominal aorta and resulting in an aortic aneurysm has never been documented. We report here a case of angiocentric T-cell lymphoma in a 33-year-old man who for months presented intermittent fever, splenomegaly, and an abdominal pulsatile mass. Angiography revealed extensive aneurysmal dilatation of the infrarenal abdominal aorta, bilateral iliac artery, and right common femoral artery. Splenic abscess and infected abdominal aortic aneurysm were initially suspected. An urgent splenectomy and aneurysmectomy with an aortic bifemoral bypass were performed. Pathological examination of the aortic aneurysm showed extensive necrosis, severe atherosclerosis, and lymphoma cell infiltration of the aortic wall. The lymphoid cells in the aorta and spleen were stained positive for CD45RO, CD56, and CD8, but negative for CD4 and CD19. Double-labeling immunohistochemistry and in situ hybridization using EBER1 for Epstein-Barr virus (EBV) revealed positive nuclear staining in the atypical T-lymphoid cells. This is the first definitive proof of peripheral T-cell lymphoma involving the abdominal aorta. Our evidence also supports that the EBV infection of T cells could be responsible for the atherosclerosis and hypertriglyceridemia, and the angiocentricity of the tumor cells apparently results in the presenting atherosclerotic aortic wall destruction, providing an additional causative concept for abdominal aortic aneurysm.

Adult↗

PubMed1999

Changes in yolk states of duck egg during long-term brining.

To elucidate the relationship between shyandan yolk formation and NaCl penetration degree, fresh duck eggs were brined in 26% NaCl and a prolonged brining test was conducted for up to 24 weeks. Shyandan yolk was obtained from brine-cured duck shell eggs in 26% NaCl for 4-6 weeks and subsequently heated at 85 degrees C for 90 min. Though NaCl contents for albumen and yolk increased to 14.8 and 8.9%, respectively, during the prolonged test for up to 24 weeks, the R values (NaCl/water x 100) were similar (increased from 0.6 to 21) throughout the brining process. The oil-off ratio of the yolk increased rapidly from 14 to 50% (0-6 weeks) and gradually decreased during the extended brining. Granulation and gelation of yolk appeared in the different stages of the brining process. This study demonstrates that the formation of shyandan yolk was determined by the degree of NaCl penetration.

Animals↗

PubMed1999

Prevalence of nonreporting behavior of sharps injuries in Taiwanese health care workers.

BACKGROUND: Health care workers (HCWs) were surveyed to identify factors associated with nonreporting behavior of sharps injuries (SIs) in Taiwan. METHODS: We surveyed 10,469 full-time medical, nursing, technical, and supporting personnel employed at 16 randomly selected hospitals from 132 available accredited teaching hospitals in Taiwan. Information about the most recent injury and reporting behavior after an SI were collected from July 1996 to June 1997 by using a pretested structured questionnaire. Eleven categories, including an open-ended option, were provided for participants to explain their nonreporting behavior. RESULTS: Questionnaires were completed by 82.6% (8645) of our sample, of whom 87.3% reported to have experienced a recent SI. A used item was the most commonly (P <. 001) involved item in an SI, and SIs with a used item were significantly more likely (odds ratio 3.6; CI 95%, 3.03-4.26; P <. 001) to be reported compared with an SI that involved unused items. A total of 81.8% of injuries were not reported, with job category significantly affecting reporting behavior (P <.001). Medical staff had the highest nonreporting rate (85.2%). Although attendees of a prevention program were statistically more likely (P <.001) to report an injury compared with nonattendees, the level of reporting in both groups was not encouraging (21.3% and 17.2%, respectively). All reasons given for nonreporting were disconcerting, but none more so than the use of subjective assessment of risk by 21.7% of HCWs who did not report their injuries. Other reasons for not reporting SIs included that the item was unused (34%) and that the HCW was too busy to report the SI (14.9%), unaware of reporting requirements (14. 4%), or immune to hepatitis B virus (12.4%). CONCLUSIONS: With 82% of SIs in Taiwanese HCWs going unreported, the expected national incidence will be seriously underestimated and impact the appropriateness of prevention programs. The very low rate of reporting suggests that the current reporting system requires simplification. Because most injuries involved used items, the reporting systems also should include a more responsive management component. The results also suggest that the current prevention programs, currently provided by the general nursing department, require expert content knowledge in infection control if nonreporting and SIs are to be reduced.

Humans↗

PubMed1999

Relaxant effects of quercetin methyl ether derivatives in isolated guinea pig trachea and their structure-activity relationships.

In the present study, we attempted to compare quercetin methyl ethers and to look for the structure-activity relationships, which may be helpful for synthesizing more active compounds for the treatment of asthma. Four present and two previously studied quercetin methyl ethers concentration-dependently relaxed histamine (30 microM), carbachol (0.2 microM) and KCl (30 mM) induced precontraction. According to their IC25 values to histamine-induced precontraction, the potency order was quercetin 3,3',4,'5,7-pentamethyl ether (QPME), quercetin 3-methyl ether > quercetin, quercetin 3,4',7-trimethyl ether (ayanin) > quercetin 4'-methyl ether (tamarixetin), quercetin 3,3',4',7,-tetramethyl ether (QTME). Therefore, the methylation at 3, at 5, and at both 3 and 7 positions of the A or/and C ring of quercetin nucleus may increase their tracheal relaxant activity. However, the methylation at the 3' and at the 4' position of the B ring of quercetin nucleus may decrease their tracheal relaxant activity.

Animals↗

PubMed1999

Mandibular lengthening by distraction osteogenesis in children--a one-year follow-up study.

OBJECTIVE: The present study was undertaken to document whether mandibular length could be increased by distraction osteogenesis in children and what happens to the mandibular position 1 year after the distraction. METHODS: Five patients with hemifacial microsomia (four unilateral, one bilateral) had distraction osteogenesis performed to lengthen the mandible. All patients had cephalometric and panoramic radiographs obtained before and 3, 6, and 12 months after the distraction osteogenesis. RESULTS: The total mandibular length (Co-Gn) on the affected side was increased by 11.2 mm after the distraction and remained stable during a 1-year observation period. However, the increased mandibular length tended to move the chin downward (8 mm) more than forward (2 mm) during the same period. CONCLUSIONS: Distraction osteogensis can be used to lengthen the hypoplastic mandible. However, most of the increased mandibular length moved the chin downward more than forward.

Activator Appliances↗

PubMed1999

Disseminated Mycobacterium genavense infection in a patient with acquired immunodeficiency syndrome: first case report in Taiwan.

Mycobacterium genavense is a recently described fastidious mycobacterium identified as a pathogen causing disseminated infection in patients with advanced human immunodeficiency virus (HIV) disease. In this report, we describe the first reported case of disseminated M. genavense infection in a patient with acquired immunodeficiency syndrome (AIDS) in Taiwan. A 22-year-old Chinese man was found to be seropositive for HIV at age 18, in 1993. In 1997, he presented with abdominal pain, weight loss, low CD4 lymphocyte count, hepatomegaly, and generalized lymphadenopathy. Microscopic examination of a biopsy specimen from an inguinal lymph node showed both ill- and well-formed noncaseating granulomas. Numerous acid-fast bacilli were present in the histiocyte cytoplasm. Although the organism did not grow on conventional solid media used in our laboratory, two molecular biology techniques, including polymerase chain reaction (PCR) followed by sequencing of 16S rRNA, and PCR together with restriction enzyme fragment polymorphism analysis, confirmed the M. genavense infection. The patient's abdominal symptoms responded well to a chemotherapy regimen that included ethambutol, ciprofloxacin, and clarithromycin, and he survived more than 6 months after diagnosis. However, the lymphadenopathy was still present at his final follow-up. Our report indicates that disseminated infection with M. genavense should be added to the list of differential diagnoses of secondary infections in advanced AIDS patients in Taiwan.

AIDS-Related Opportunistic Infections↗

PubMed1998

Clinical and electrophysiologic characteristics and long-term efficacy of slow-pathway catheter ablation in patients with spontaneous supraventricular tachycardia and dual atrioventricular node pathways without inducible tachycardia.

OBJECTIVES: We sought to investigate the long-term efficacy of slow-pathway catheter ablation in patients with spontaneous, documented paroxysmal supraventricular tachycardia (PSVT) and dual atrioventricular (AV) node pathways but without inducible tachycardia. BACKGROUND: The lack of reproduction of clinical PSVT by programmed electrical stimulation, which is not uncommon in AV node reentrant tachycardia (AVNRT), is a dilemma in making the decision of the therapeutic end point of radiofrequency catheter ablation. METHODS: Twenty-seven patients (group A) with documented but noninducible PSVT and with dual AV node pathways were prospectively studied. Programmed electrical stimulation could induce a single AV node echo beat in 12 patients, double echo beats in 4 patients and none in 11 patients at baseline or during isoproterenol infusion. Of the patients in group A, 16 underwent slow-pathway catheter ablation and 11 did not. The clinical and electrophysiologic characteristics of the 27 patients were compared with those of patients with dual AV node pathways and inducible AVNRT (group B, n = 55) and patients with dual AV node pathways alone without clinical PSVT (group C, n = 47). RESULTS: During 23+/-13 months of follow-up, none of the 16 patients with slow-pathway catheter ablation had recurrence of PSVT. However, 7 of the 11 patients without ablation had PSVT recurrence at 13+/-14 months of follow-up (p < 0.03 by Kaplan-Meier analysis). Compared with groups B and C, group A consisted predominantly of men who had better retrograde AV node conduction and a narrower zone for anterograde slow-pathway conduction. CONCLUSIONS: Slow-pathway catheter ablation is highly effective in eliminating spontaneous PSVT in which the tachycardia is not inducible despite the presence of dual AV node pathways.

Adolescent↗