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Biomedical subjects

T L Wu

Publications and source records attributed to T L Wu.

At least 37 records · Page 2Linked to original sources

Klebsiella pneumoniae bacteremia: community-acquired vs. nosocomial infections.

BACKGROUND: This study attempted to determine the clinical manifestations and influential factors affecting the prognosis of patients with community-acquired and nosocomial bacteremia of Klebsiella pneumoniae (K. pneumoniae). METHODS: We retrospectively reviewed the medical records of 211 patients who had a clinically significant episode of K. pneumoniae bacteremia from January 1997 until December 1999. RESULTS: Most reports describe K. pneumoniae bacteremia as typically nosocomial, but in our study approximately 3 of 4 episodes were community-acquired. Without including "unknown origin", the most common infectious site for both community-acquired and nosocomial bacteremia was the hepatobiliary tract. The overall mortality for all 211 patients with K. pneumoniae bacteremia was 25.1%. Significantly higher mortality rates occurred in patients who were elderly (> 65 years), had a nosocomial infection, for whom the respiratory tract was the portal of entry, and ultimately fatal conditions or acute complications were due to shock or renal insufficiency. CONCLUSIONS: Patients with community-acquired and nosocomial bacteremia had different types of underlying diseases. Isolates from nosocomial infections were significantly more frequently resistant to aminoglycosides, antipseudomonal penicillin, and all three generations of cephalosporins. In this regard, an aggressive empirical therapeutic approach to infections of K. pneumoniae is suggested.

Adult↗

Non-radioactive Southern hybridization for early diagnosis of alpha-thalassemia with southeast Asian-type deletion in Taiwan.

Alpha-thalassemia has been estimated to account for over 60% of hydrops fetalis cases in Taiwan. The most common genotypic lesion found in alpha-thalassemia-1 cases in Taiwan is deletion of a large segment of the alpha-globin gene cluster, termed the Southeast Asian-type deletion (-SEA/; further referred to as SEA-type deletion). Seven chorionic villus samples (CVS) from pregnancies of couples both heterozygous for SEA-type deletion were studied. Non-radioactive Southern-blot hybridization using the dig-alkaline phosphatase detection system was developed to fulfill this purpose. The results were compared with corresponding polymerase chain reaction (PCR) data to elucidate the effectiveness of these two protocols in the diagnosis of the SEA-type deletion. The data showed that of the seven CVS, three demonstrated a distinctive band pattern, indicating their homozygous status of SEA-type deletion, whereas two showed heterozygous patterns, and the other two were free of the deletion. Homozygosity of the deletion was confirmed by Southern-blot hybridization performed on DNA samples extracted from the abortus tissue. However, two of the three cases with SEA-type deletion showed heterozygous PCR results. Maternal cell contamination could be responsible for the artifacts in the PCR results, but the influence due to the contamination is minimal in non-radioactive Southern-blot hybridization. We concluded that PCR is suitable for screening of carrier adults with SEA-type deletion, and non-radioactive Southern hybridization is ideal for early prenatal diagnosis of the SEA-type deletion.

Asia, Southeastern↗

Molecular investigation of two clusters of hospital-acquired bacteraemia caused by multi-resistant Klebsiella pneumoniae using pulsed-field gel electrophoresis and in frequent restriction site PCR. Infection Control Group.

Two molecular typing methods, DNA macrorestriction analysis with XbaI resolved by pulsed-field gel electrophoresis (PFGE) and infrequent restriction site PCR (IRS-PCR) assay with adapters designed for XbaI and HhaI restriction sites, were used to investigate two clusters of hospital-acquired bacteraemia associated with multi-resistant Klebsiella pneumoniae which occurred in a paediatric intensive care unit (PICU). A total of 56 K. pneumoniae isolates were analysed. These included 10 bacteraemic isolates from eight patients, 26 isolates obtained during an epidemiological survey, and 20 epidemiologically non-related isolates incorporated as controls. One major pattern was demonstrated in 22 of the 56 isolates analysed. These included nine of the 10 bacteraemic isolates, a single rectal isolate, two hand culture isolates and 10 sink isolates. All of these 22 isolates illustrated identical antibiograms, whilst the other 34 isolates shared six antibiograms and 31 unique patterns by either PFGE or IRS-PCR assay. The two clusters of bacteraemia appeared to be outbreaks induced by the same strain of K. pneumoniae which may have utilized sinks as reservoirs and been transmitted through the hands of medical personnel to patients. IRS-PCR demonstrates concordant results with PFGE analysis in studying the genetic relationships among K. pneumoniae isolates, and serves as an excellent epidemiological tool for this bacterium.

Bacteremia↗

Multicenter surveillance of antimicrobial resistance of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in Taiwan during the 1998-1999 respiratory season.

A susceptibility surveillance study of 276 isolates of Streptococcus pneumoniae, 301 of Haemophilus influenzae, and 110 of Moraxella catarrhalis was carried out from November 1998 to May 1999 in Taiwan. High rates of nonsusceptibility to penicillin (76%), extended-spectrum cephalosporins (56%), azithromycin (94%), clarithromycin (95%), and trimethoprim-sulfamethoxazole (TMP-SMX) (65%) for S. pneumoniae isolates and high rates of nonsusceptibility to amoxicillin (58%) and TMP-SMX (52%) for H. influenzae isolates were found. Higher percentages of S. pneumoniae isolates nonsusceptible to aminopenicillins, extended-spectrum cephalosporins, macrolides, and TMP-SMX were observed among penicillin-intermediate and -resistant isolates. All quinolones tested were active in vitro against these three organisms.

Drug Resistance, Microbial↗

Elevated serum chromogranin A is detectable in patients with carcinomas at advanced disease stages.

Chromogranin A (CgA), a marker of neuroendocrine cells and an indicator for neuroendocrine differentiation, is associated with a poor prognosis when detected in tumor tissue, based on immunohistochemical techniques. We sought to determine whether it is possible to detect elevated serum CgA in patients with commonly occurring carcinomas of non-neuroendocrine origin. CgA was measured in both random and serial serum specimens, using a serum CgA assay developed in our laboratory. Elevated levels of serum CgA were detected in patients with carcinoma of the prostate, breast, ovary, pancreas, and colon. Serum CgA levels in patients with all types of carcinoma appeared to parallel the changes of serum dominant tumor markers and were found in sera containing highly elevated tumor markers. Based on these preliminary findings, perhaps we should monitor CgA, in addition to the routinely used tumor markers, during the treatment of patients with carcinomas to determine if CgA is useful as a prognostic marker in carcinomas other than prostatic cancer.

Biomarkers, Tumor↗

DNA polymorphism of Mycobacterium abscessus analyzed by infrequent-restriction-site polymerase chain reaction.

BACKGROUND: Mycobacterium abscessus is an important pathogen that has been increasingly associated with many clinical and nosocomial infections. A reliable molecular typing scheme is essential for the epidemiological study of this rapidly growing mycobacterium. Pulsed-field gel electrophoresis (PFGE), considered to be the gold standard among molecular typing methods, has failed to provide satisfactory results in the molecular typing of this bacterium. A newly developed molecular typing method, infrequent-restriction-site polymerase chain reaction (IRS-PCR), was examined in this study to determine its suitability for fingerprinting M. abscessus isolates. METHODS: Eight clinical isolates of M. abscessus and two reference strains (M. abscessus ATCC 19977 and M. chelonae ATCC 35749) were studied by DNA macrorestriction analysis with XbaI resolved by PFGE, and IRS-PCR assay with adaptors designed for XbaI and HhaI restriction sites. RESULTS: By PFGE, different banding patterns were found in two clinical isolates of M. abscessus; the other isolates yielded only broken DNA and could not be assessed. By IRS-PCR, unique patterns were noted for the 10 isolates; the 10 appeared to be genetically different. CONCLUSION: IRS-PCR may be an efficient substitute for PFGE in analyzing the DNA polymorphism and epidemiology of M. abscessus.

Electrophoresis, Gel, Pulsed-Field↗

Vibrio parahemolyticus bacteremia: case report.

Vibrio parahemolyticus (V. parahemolyticus) is a halophilic gram-negative bacillus that lives in the ocean. It is the leading cause of infectious diarrhea in Taiwan and sometimes produces soft tissue infections, but it is rarely a cause of bacteremia. There have been only 11 cases reported in the literature. Most of the cases involved a history of ingestion of seafood or exposure to seawater. In addition, those patients were all immunosuppressed, especially with leukemia and cirrhosis. We report a 60-year-old male patient with chronic hepatitis C and adrenal insufficiency. He developed V. parahemolyticus bacteremia following ingestion of seafood one week prior to admission. His condition was complicated with neck and right lower leg soft tissue infection, as well as multiple organ failure. The patient survived after intravenous ceftazidime, oral doxycycline, and surgical debridement. To our knowledge, this is the 12th reported cases on Medline, and the second bacteremic case in Taiwan. After reviewing the literature, we suggest that all patients with immunosuppressed conditions or adrenal insufficiency should eat foods that are well cooked and avoid raw seafood. Moreover, when patients who are at risk to develop fever, diarrhea, and soft tissue infection after ingestion of seafood, V. parahemolyticus infection should be suspected. All culture specimens should be inoculated on Vibrios selective media.

Bacteremia↗

Different patterns of serum chromogranin A in patients with prostate cancer with and without undergoing hormonal therapy.

Elevated serum chromogranin A (CgA) levels have been detected in patients with prostate cancer who have developed resistance to hormonal therapy. We would like to reexamine these cases by using serial specimens to determine whether such elevated levels are also detectable in prostate cancer patients not undergoing hormonal therapy. Serum CgA was measured in both random and serial specimens from prostate cancer patients with and without undergoing hormonal therapy. We found that serum CgA levels became elevated much earlier than did the levels of serum PSA in approximately one-third of prostate cancer patients developing resistance to hormonal therapy. On the other hand, serum CgA levels became elevated at later, more advanced stages of the disease in patients not undergoing hormonal therapy. Elevated serum CgA levels were usually detected in specimens containing highly elevated PSA. The early rise of serum CgA levels provides an early signal allowing a change of therapy to be made before the disease progresses to a fatal stage. Drugs targeting neuroendocrine cells should be considered for prostate cancer patients with elevated serum CgA levels.

Antineoplastic Agents, Hormonal↗

Development of a microplate assay for serum chromogranin A (CgA): establishment of normal reference values and detection of elevated CgA in malignant diseases.

Chromogranin A (CgA), a marker for neuroendocrine cells, is associated with poor prognosis when detected by immunohistochemical technique in prostate tumors. We have developed an ELISA on microplates for serum CgA and established the normal reference range. We also attempted to find out whether elevated serum CgA levels could be found in patients with various malignant diseases. Because of non-Gaussian distribution, both medians and 97.5 percentiles of serum CgA levels for men and women of four different age groups were determined. For women, the median and 97.5 percentiles are 20.7 and 63.9 ng/mL for ages 20 to 50, and 32 and 93.8 for 50 to 80 years of age, respectively; for men, they are 27.9 and 78.4 ng/mL for ages 18 to 40 and 41.6 and 92 for 40 to 80 years old, respectively. Elevated serum concentrations of CgA were detectable in patients with prostate cancer not undergoing hormonal treatment, and in patients with various malignant diseases including nonendocrine carcinomas. Most elevated serum CgA levels were associated with sera containing highly elevated serum tumor markers. Drugs targeting neuroendocrine cells should be administered for cancer patients with elevated serum CgA levels.

Adult↗

Laparoscopic resection of an omental cyst with pedicle torsion.

Omental cysts are the least-common variety of all types of intra-abdominal cystic lesions. In the past, transabdominal laparotomy with excision of the cyst was the treatment of choice. With the advent of laparoscopic surgery, it has become possible to resect the cyst without the need for a large incision in the abdomen. We report a case of a 15-year-old girl who underwent diagnostic laparoscopy for recurring abdominal pain of 2 years' duration. The procedure revealed a huge cyst lying above the omentum with its pedicle rising from the greater curvature of the stomach. The pedicle was noted to have twisted eight times in a clockwise direction. The cyst was resected by laparoscopic means using three trocars. The postoperative course was uneventful. As presented in this case, we believe that a laparoscopic approach is an attractive alternative for the management of omental cystic lesions.

Abdominal Pain↗

Primary pyogenic abscess of the psoas muscle.

During a six-year period, eleven persons with primary pyogenic abscess of the psoas muscle were treated at the Mackay Memorial Hospital. Five were males and six were females and their average age was 47.2 years (range 6-83 years). The abscess was identified by CT in 7 patients, MRI in 2 and ultrasonography in 1. One abscess was found during laparotomy. Treatment included extraperitoneal drainage of the abscess in 7 patients and CT guided aspiration in 3. One patient improved after antibiotic therapy and they all recovered after treatment. The diagnosis of primary pyogenic abscess requires a high index of suspicion and the best treatment is early operative drainage and administration of systemic antibiotics.

Adolescent↗

Effect of the gasoline additives on PAH emission.

PAH emission from the powered engines fueled by a 95 leadfree gasoline (95-LFG), a 92 leadfree gasoline (92-LFG) and a Premium leaded gasoline (PLG) with two gasoline additives (SA and SB) were collected using a PAH sampling system with a particulate interception device. Twenty one PAHs were analyzed primarily by an GC/MS, while eight metal elements were determined mainly by an ICP-AES. This investigation showed that the gasoline additives contain more amounts of carcinogenic PAHs than gasolines do. Blending these additives do raise the PAH content in the gasolines, simultaneously, will emit more amount of PAHs from the tailpipe of engine exhaust. It is suggested that before a gasoline additive is commercialized, an assessment on its PAH emission should be evaluated to make sure that the additive will not emit more PAHs and cause adverse effect on public health.

Carcinogens↗

Penicillium marneffei fungemia in an AIDS patient: the first case report in Taiwan.

We report a 36-year-old man with acquired immunodeficiency syndrome (AIDS), presenting systemic Penicillium marneffei (PM) infection. Fungal culture from the blood isolated PM. PM-induced enteritis was also suspected in this patient although there was no direct evidence. He also had other manifestations of immunocompromised status, including military tuberculosis and oral candidiasis. He died of respiratory failure in spite of prompt treatment for infection. This is the first confirmed case of PM infection in Taiwan.

Acquired Immunodeficiency Syndrome↗

Opposing mitogenic and anti-mitogenic actions of parathyroid hormone-related protein in vascular smooth muscle cells: a critical role for nuclear targeting.

Parathyroid hormone-related protein (PTHrP) is a prohormone that is posttranslationally processed to a family of mature secretory forms, each of which has its own cognate receptor(s) on the cell surface that mediate the actions of PTHrP. In addition to being secreted via the classical secretory pathway and interacting with cell surface receptors in a paracrine/autocrine fashion, PTHrP appears to be able to enter the nucleus directly following translation and influence cellular events in an "intracrine" fashion. In this report, we demonstrate that PTHrP can be targeted to the nucleus in vascular smooth muscle cells, that this nuclear targeting is associated with a striking increase in mitogenesis, that this nuclear effect on proliferation is the diametric opposite of the effects of PTHrP resulting from interaction with cell surface receptors on vascular smooth muscle cells, and that the regions of the PTHrP sequence responsible for this nuclear targeting represent a classical bipartite nuclear localization signal. This report describes the activation of the cell cycle in association with nuclear localization of PTHrP in any cell type. These findings have important implications for the normal physiology of PTHrP in the many tissues which produce it, and suggest that gene delivery of PTHrP or modified variants may be useful in the management of atherosclerotic vascular disease.

Adaptor Proteins, Signal Transducing↗

Structural and physiologic characterization of the mid-region secretory species of parathyroid hormone-related protein.

Parathyroid hormone-related protein (PTHrP) is initially translated as a preprohormone which is posttranslationally processed to yield a family of mature secretory forms. Most attention has focused on the amino-terminal portion of the molecule which is homologous to parathyroid hormone. It is clear, however, that a mid-region species of PTHrP is posttranslationally cleaved from the highly conserved mid-region of PTHrP, and that the amino terminus of this peptide is Ala38. The purposes of the current study were three: 1) to confirm that Arg37 immediately preceding Ala38 serves as a posttranslational processing site in the PTHrP precursor, 2) to determine the carboxyl terminus of the mid-region secretory species of PTHrP, and 3) to synthesize this authentic mid-region secretory form of PTHrP and determine whether it is biologically active. The results indicate that: 1) Arg37 is indeed a processing site in the PTHrP precursor; 2) three distinct mid-region PTHrP species are generated by posttranslational processing, PTHrP(38-94)amide, PTHrP(38-95), and most likely, PTHrP(38-101); and 3) synthetic mid-region PTHrP(38-94)amide is active in four different biological systems. These studies confirm the finding that PTHrP is a prohormone. More importantly, they define a novel, biologically active highly conserved mid-region secretory form of PTHrP.

Amino Acid Sequence↗

Vectorcardiography in experimental myocardial infarction. Serial changes and correlation between QRS loop change and the infarction size.

The objectives of this study were to examine the serial vectorcardiographic changes following acute myocardial infarct and to assess the relationship between QRS loop changes and infarct size. Fifty adult male Long-Evans rats of 250-350 gm body weight were used to study experimental acute myocardial infarction induced by coronary artery ligation. Vectorcardiograms (VCG) of the Frank lead system were recorded before, and 1 day and 7 days after operation. Animals were sacrificed on the 7th day for histological quantitation of infarct area ratios. We found that (1) before operation, rats have ST elevation, probably due to early repolarization. (2) After coronary artery ligation, ECG showed characteristic dome-shaped ST elevation at 1 hr after ligation which returned to normal during the first day. Abnormal Q waves appeared thereafter. (3) After ligation, maximum QRS vector, ST vector and maximum T vector were reduced in magnitude the first day and recovered by the 7th day. The vectors tended to shift their direction to the right and to the posterior. QRS-T angle, however, widened as time went on. About half of the rats revealed changes in the inscription direction of the QRS loop and abnormal QRS morphology also appeared in about half of the ligated rats. (4) Those in whom abnormal QRS loop morphology and/or biting appeared had significantly larger infarct area ratios (p < 0.01). (5) Change in QRS loop inscription direction seemed not to be related to the infarct size. (6) In the LS plane, the difference in max QRS vector magnitude between the 1st and 7th days significantly correlated with the infarct area ratio (r = 0.533, p < 0.05). In the H plane, the change in the max QRS vector magnitude at the 7th day correlated with the infarct area ratio (r = -0.531, p < 0.05). In the F plane, changes in the direction of the max QRS vector were significantly correlated to the infarct area ratio both on the first (r = 0.431, p < 0.05) and 7th days (r = 0.531, p < 0.05). It is concluded that the VCG, like the ECG, had evolutional changes in AMI and that the QRS loop seen on vectorcardiography has only a slight correlation with the histological myocardial infarct size.

Animals↗