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Biomedical subjects

T M Wang

Publications and source records attributed to T M Wang.

At least 37 records · Page 2Linked to original sources
PubMed1997

Susceptibility of Pseudomonas aeruginosa of various pyocin types to the newly synthesized ampicillin derivative, N-(6,7-difluoroquinolonyl)ampicillin.

Six hundred and thirty-two isolates of Pseudomonas aeruginosa of 17 pyocin types were collected in 1993 in Taiwan. Types 1, 10, 3, 35 and 12 were the most common pyocin types identified in Taiwan with isolation frequencies of 47.3%, 24.4%, 7.6%, 3.6% and 2.2%, respectively. Several pyocin subtypes were determined. All pyocin types (one isolate of each tested) were resistant to ampicillin and nalidixic acid, but sensitive to fluoroquinolone antibiotics, such as norfloxacin and enoxacin, indicating that cross-resistance to quinolone antibiotics of nalidixic acid and fluoroquinolone derivatives has not developed. A new ampicillin derivative of 6,7-difluoroquinolonic acid, N-(6,7-difluoroquinolonyl)-ampicillin (AU-1), was synthesized by coupling ampicillin with 6,7-difluoroquinolonic acid (FP-3). Compound AU-1 was much more active than either ampicillin or FP-3 alone against all pyocin types of P. aeruginosa and induced filamentation in most growing cells.

Ampicillin↗
PubMed1997

[Identification of Staphylococcus epidermidis by desferrioxamine susceptibility and trehalose fermentation tests].

The importance of coagulase-negative staphylococci, especially Staphylococcus epidermidis in clinical and nosocomial infection are recognized increasingly in recent years. A rapid and accurate identification of S. epidermidis is therefore important and necessary. A new test, susceptibility to desferrioxamine, coupled with trehalose fermentation has been recommended for the identification of this organism. However, the medium and method used are different from what has been recommended by the NCCLS. To investigate the feasibility of using the desferrioxamine susceptibility test in conjunction with the routinely used disc agar diffusion test, we employed 111 staphylococcal strains (including 51 S. epidermidis isolates, 15 S. hominis and 45 other coagulase-negative staphylococci) as test organisms, and followed the procedures recommended by the NCCLS in which Mueller-Hinton agar and standard inoculum were used. Results indicated that all strains of S. epidermidis and S. hominis were susceptible to 1 mg desferrioxamine (the diameter of the inhibition zone were 28-37 mm). The minimum inhibitory concentrations of desferrioxamine to S. epidermidis and S. hominis isolates were determined to be 125 micrograms/ml. Further differentiation of S. hominis and S. epidermidis can be made by their ability to ferment trehalose, the former could while the latter could not. We conclude that the desferrioxamine susceptibility test of coagulase-negative staphylococci can be used in conjunction with the routine disc agar diffusion method. S. epidermidis can be identified rapidly and accurately by its susceptibility to 1 mg desferrioxamine and inability to ferment trehalose.

Deferoxamine↗
PubMed1997

Use of the transurethral prostatectomy clinical path to monitor health outcomes.

PURPOSE: We evaluated the effect on cost and medical care quality of use of the transurethral prostatectomy clinical path. MATERIALS AND METHODS: Results in 100 patients treated when the transurethral prostatectomy clinical path was used were compared to those of 100 treated by the same physicians before implementation of this path. RESULTS: After implementation of the transurethral prostatectomy clinical path the length of hospital stay was significantly decreased from 5.9 to 5.0 days (p < 0.01) and Foley catheterization time was significantly decreased from 3.13 to 2.84 days (p < 0.01). Antibiotics were routinely used from the day before surgery to the day of hospital discharge as required by patient conditions. Therefore, a shorter hospital stay will significantly decrease the use of antibiotics. After implementation of the clinical path the average admission charges were decreased significantly by 17% (p < 0.01). Although some results from use of this path will not significantly affect costs, they will reflect some quality improvement. The effect of clinical path implementation on length of hospital stay between patients treated by junior and senior attending physicians was not significant. However, there was a statistically significant difference (p < 0.01) between results obtained by junior and senior attending physicians regarding average admission charges. CONCLUSIONS: Implementation of the transurethral prostatectomy clinical path can improve health care outcome by decreasing length of stay and admission charges, and improving quality of medical care, particularly for patients treated by junior attending physicians.

Aged↗
PubMed1997

Diagnosis of prostate cancer: comparison of serum prostate specific antigen, digital rectal examination and transrectal ultrasonography.

BACKGROUND: While prostate specific antigen (PSA) is useful as a tumor marker for monitoring patients with prostate cancer after definitive therapy, limitations have been noted when it is used for early detection of prostate cancer. METHODS: We reviewed the charts of 121 patients who had undergone prostate needle biopsies, documented digital rectal examination (DRE) and serum PSA determination before biopsy from January 1993 to October 1994. Indications for biopsy included abnormal DRE. PSA level greater than 4.0 ng/ml or abnormal lesions on transrectal ultrasonography (TRUS). RESULTS: Seventeen patients (14%) had stage A carcinoma with normal DRE and PSA levels from 0.1 to 34.9 ng/ml (mean 9.0 ng/ml). Four patients (3%) had stage B carcinoma with an average PSA level of 32.3 ng/ml and less than one lobe indurated on DRE. Six patients (5%) had stage C carcinoma and had an average PSA level of 48.5 ng/ml and less than one lobe indurated on DRE. Ninety-four (78%) patients had stage D carcinoma with an average PSA level of 120 ng/ml and more than one lobe indurated on DRE. While hypoechoic sectors were more than twice as likely as isoechoic sectors of the prostate to contain malignancy on biopsy, nearly 20% of cancers were found in isoechoic sectors. CONCLUSION: Serum PSA is the most accurate of the three diagnostic tests evaluated. The addition of DRE or TRUS improves the detection rate of prostate cancer over PSA alone.

Aged↗
PubMed1997

Retained vaginal gauze with unusual complication: a case report.

We report a case of a postpartum retained vaginal gauze which migrated to the bladder and presented as a bladder stone. The patient had received numerous clinical evaluations for her chronic abdominal pain, of all which failed to detect or indicate the presence of retained gauze. Retained surgical gauze is a preventable problem but continues to occur periodically. Prevention remains the key to this problem. The gauze packed within the vagina either after transvaginal surgery or delivery should be cared for as in other parts of the body. Though extremely rare, retained surgical gauze should be considered in the differential diagnosis in postpartum patients with chronic abdominal pain, irritable bladder symptoms or pelvic abscess.

Abdominal Pain↗
PubMed1996

Effects of 4-aminopyridine on saxitoxin intoxication.

Effects of 4-aminopyridine (4-AP) on neurotoxicity induced by saxitoxin (STX) are investigated in this study. In vitro, twitch tension evoked by nerve stimulation was depressed by STX (1.35 nM) in rat phrenic nerve-diaphragm preparations, and this inhibition was antagonized by 4-AP (0.1 mM). In addition, 4-AP (0.1 mM) restored the firing of membrane action potentials that were suppressed or even abolished by 0.334 nM STX in frog sartorius muscles. In vivo studies showed that 4-AP (0.3 mg/kg, iv) significantly reversed the respiratory rate, tidal volume, and blood pressure to normal values in anesthetized STX-toxicosis rats. Furthermore, 4-AP (0.75-6 mg/kg, ip) not only prolonged the survival time but also decreased the mortality of mice (71-43%) at a normally lethal dose (30 micrograms/kg, ip) of STX. The results suggest that 4-AP may be useful as an antidote for STX intoxication.

4-Aminopyridine↗
PubMed1996

Cytotoxic effects of anthrax lethal toxin on macrophage-like cell line J774A.1.

The cytotoxic effects of anthrax lethal toxin purified from an avirulent strain were examined on mouse macrophage-like J774A.1 cells. Cell death induced by high concentration of purified lethal toxin had the characteristics of necrosis. At lower concentrations, the toxin caused no morphological change and most of the cells were viable. Interestingly, apoptotic cells were observed when the cells were preincubated with a serine/threonine phosphatase inhibitor, calyculin A, and then exposed to a toxin concentration of 0.1 microg/ml. This is the first report that lethal toxin of the anthrax bacillus can induce both necrosis and apoptosis and that protein phosphatases are implicated in the regulation of bacterial toxin-induced apoptosis.

Animals↗
PubMed1996

Identification of immunodominant, group-specific and subcomplex-specific, continuous epitopes in the core regions of Japanese encephalitis virus using synthetic peptides.

Two flaviviruses, Japanese encephalitis (JE) virus and Dengue (DEN) virus which have high pathogenicity for humans, continue to pose a serious public health problem in tropical and subtropical countries of the world. In order to identify the immunodominant B-cell epitopes for diagnostic application, we have prepared a series of 15-mer synthetic peptides from JE virus core protein based on computer analysis. Four linear, immunodominant epitopes corresponding to amino acids 91-105 (P78), 1-15 (P73), 8-22 (P74), and 34-48 (P75) of JE virus core proteins were identified by employing an enzyme-linked immunosorbent assay (ELISA), using high-titered immune sera from JE-vaccinated children. P78 was found to be the most immunodominant. The sero-specificity of these peptides was tested by binding to seroconverted samples from JE and DEN-1 patients. P78 and P74 belonged to group-specific epitopes which reacted with both JE and DEN-1 patient sera. P73 and P75 belonged to subcomplex-specific epitopes which reacted only with JE but not with DEN-1 patient sera. The study suggests that these peptides corresponding to the immunodominant epitopes of JE virus core protein might have the potential to be used as peptide-based diagnostic reagents for the detection and differentiation of JE and DEN antibody responses.

Adult↗
PubMed1996

Characterization of the NTPase activity of Japanese encephalitis virus NS3 protein.

Japanese encephalitis (JE) virus NS3 protein and two N-terminally truncated (delta 1-148 and delta 1-323) forms of NS3 were engineered and expressed in E. coli as fusion proteins with a histidine tag at the N terminus. The purified recombinant proteins his-NS3 and his-NS3(delta 1-148) were found to possess NTPase activity which was stimulated by single-stranded RNA, whereas NS3(delta 1-323) did not. The requirements for MgCl2 and MnCl2 and the salt and pH ranges necessary for optimal activity of the enzyme were determined and shown to be slightly different from those of the NTPases of other flaviviruses. Poly(U) and poly(C) were better than poly(A) at stimulating the NTPase activities, in contrast to other flaviviral NTPases. The substrate preference was in the order GTP > ATP >> UTP > CTP. Interestingly, we found that Ca2+ could not substitute for Mg2+; on the contrary, it inhibited NTPase activity. The removal of the N-terminal 148 amino acids enhanced NTPase activity, but further deletion of the region (amino acids 148-323) completely abolished the activity. Therefore, amino acids 148-323 contain a critical region required for NTPase activity.

Acid Anhydride Hydrolases↗
PubMed1995

Multiplex polymerase chain reaction to detect toxigenic Vibrio cholerae and to biotype Vibrio cholerae O1.

A multiplex polymerase chain reaction (PCR) was developed to identify cholera toxin-producing Vibrio cholerae and to biotype V. cholerae O1. Enterotoxin-producing V. cholerae strains were identified with a primer pair that amplified a fragment of the ctxA2-B gene. Vibrio cholerae O1 strains were simultaneously differentiated into biotypes with three primers specified for the hylA gene in the same reaction. The hlyA amplicon in the multiplex PCR serves as an internal control when testing toxin-producing strains, as hlyA gene sequences exist in all tested V. cholerae strains. Enrichment of V. cholerae present on oysters for 6 h in alkaline peptone water before detection by a nested PCR with internal primers for ctxA2-B gene yielded a detection limit lower than 3 colony-forming units (cfu) per gram of food.

Animals↗
PubMed1993

Evidence for reduced cancellous bone mass in the spontaneously hypertensive rat.

The histomorphometric changes in the proximal tibial metaphysis and epiphyseal growth plate and midtibial shaft of 26-week-old spontaneously hypertensive rats (SHR) compared with those of the corresponding normotensive Wistar-Kyoto (WKY) rats were studied. A decrease in body weight, growth plate thickness, and longitudinal growth rate of the proximal tibial epiphysis, trabecular bone volume, trabecular thickness and number, the number of osteoblasts and osteoprogenitor cells per millimeter square surface of the proximal tibial metaphysis, periosteal and endocortical apposition rate and bone formation rate of the tibial diaphysis were observed in the SHR. Additionally, systolic blood pressure, the number of osteoclasts per millimeter square surface and average number of nuclei per osteoclast of the proximal tibial metaphysis were significantly increased. Thus, osteoclastic activity is dominant over osteoblastic and chondroblastic activity in the SHR that results in a cancellous bone deficit in the skeleton. It will require additional work to ascertain the underlying cause for this condition as several factors in the SHR with a potential for causing this change are present, including elevated parathyroid hormone (PTH), depressed 1,25-(OH)2D3, low calcium absorption, reduced body weight (reduced loading) elevated blood pressure and possibly other direct cell differences in the mutant strain. At present elevated PTH and adaptation to underloading from reduced weight are postulated to be a likely cause, but additional studies are required to test this interpretation.

Animals↗
PubMed1993

Pseudomonas septicemia in infants and children: a retrospective analysis of 49 cases.

Reviewed 49 cases of Pseudomonas bacteremia which occurred in pediatric patients during an 8-year period showed the annual rate, per 1000 discharges, was 1.7. In most of the patients (73.5%), the disease was hospital-acquired. Male to female distribution was about 3 to 2. The average age of the 49 patients was 1.29 years, and 55.1% were infected at less than 2 months old. Overall mortality was 44.9%; among the mortalities, 63.6% were under two months of age. Clinical features were not characteristic, but the most common sign associated with this infection was fever (42.9%). Ecthyma gangrenosum occurred in only one patient. Respiratory tract and skin were the most frequent sources of the bacteremia. Polymicrobial bacteremia occurred in 18.4%. Patients with shock, pneumonia, inadequate antibiotic therapy or persistent neutropenia had a substantially poorer prognosis. Administration of combination therapy to patients with Pseudomonas bacteremia seemed to be superior to monotherapy for positive outcome.

Adolescent↗
PubMed1993

Seminal vesicle cyst: an unusual cause of hematospermia--a case report.

Seminal vesicle cyst is a rare disease. The traditional diagnostic method is the vasoseminal vesiculography. We present one case detected by transrectal ultrasonography during examination for hematospermia. He was treated with transperineal aspiration and sclerotherapy under guidance of ultrasonography. The patient had an uneventful clinical course after treatment, but long term follow up is necessary. Literature about seminal vesicle cyst and hematospermia will be reviewed.

Adult↗
PubMed1992

Morphometric variations of the lumbar vertebrae between Chinese and Indian adults.

A morphometric study of the lumbar vertebrae of 126 adult skeletons, 90 Chinese and 36 Indian, of both sexes without marginal osteophytes were performed. In each lumbar vertebra, the cephalad and caudad midsagittal diameters, the interpedicular diameter of the spinal canal as well as the midsagittal and transverse diameters and the height of the vertebral body were measured. The results showed that the midsagittal and transverse diameters, the heights of the lumbar vertebral bodies and the interpedicular diameters of the lumbar spinal canals increased progressively from L1 to L5, while the midsagittal diameters of the lumbar spinal canals decreased progressively from L1 to L5 in both Chinese and Indian adult skeletons. The lowest mean values of the cephalad and caudad midsagittal and the interpedicular diameters of the spinal canals in Chinese were found to be 5.04 +/- 0.15 mm at L5, 4.67 +/- 0.09 mm at L5 and 25.92 +/- 0.20 mm at L2, respectively, while in Indians they were found to be 4.54 +/- 0.18 mm at L5, 4.25 +/- 0.10 mm at L5 and 25.42 +/- 0.22 mm at L1, respectively. In addition, the mean diameters of the spinal canal and the vertebral body (except the height of the vertebral body) were significantly greater in the Chinese than in the Indian skeletons. The above findings indicate that the mean diameters of both the lumbar spinal canal and the vertebral body vary greatly between Chinese and Indian adults, i.e. there are no mean values of the vertebral dimensions that are valid for all populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Surgical anatomy of the mandibular ramus of the facial nerve in Chinese adults.

One hundred and twenty Chinese adults' facial halves were selected for this study. The description of the mandibular ramus of the facial nerve was presented under 4 items: (1) the relationship with the lower border of the mandible, (2) the number of its rami, (3) the relationship with the retromandibular vein, the facial vein or the facial artery, and (4) its anastomoses with the buccal ramus and/or the cervical ramus. In these specimens, anterior to the facial artery, 90% of the mandibular rami ran above the lower border of the mandible, and 10% of the mandibular rami ran below the lower border of the mandible. Posterior to the facial artery, 67% of the mandibular rami ran above the lower border of the mandible, and 33% of the lowest mandibular rami passed in an arc with an average of 0.95 cm (the lowest point being 3 cm or less) below the lower border of the mandible. In 32% of the specimens, the mandibular ramus had no branch and in 68% of the specimens, the mandibular ramus had two or more rami. There were 100% of the mandibular rami lying superficially to the retromandibular vein and the facial vein, while in 5% of the specimens, some other mandibular rami ran deeply to the facial vein. In 83% of the specimens, the mandibular rami lay only superficially to the facial artery and in only 2% deeply to the facial artery. The remaining 15% ran both deeply and superficially to the facial artery. There were 60% of the specimens in which the mandibular rami had one or more anastomoses with the buccal rami.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Double aortic arch associated with severe left ventricular dysfunction--a case report].

A case of a 3-month-old male infant with severe LV dysfunction and a complete double aortic arch (both arches patient) is reported. The right dominant aortic arch runs retroesophageally to the right and joins with the left smaller arch to form the descending thoracic aorta on the right side while the ligamentum arteriosum was located in its normal position (the left side). Through a left thoracotomy, the smaller left arch and the ligamentum were divided to relieve the obstruction of the trachea from compression of the vascular ring. Postoperative convalescence was good. Further follow up of this patient after 9 months showed that there was neither any respiratory failure nor any heart failure sign present, though severe LV dysfunction persisted.

Aorta, Thoracic↗
PubMed1988

Assessment of the relative locations of the greater palatine foramen in adult Chinese skulls.

One hundred dry skulls of adult Chinese of both sexes were studied. They were homogeneous in the form of maxillary arch and having full eruption of the upper third molar, without missing teeth and malposition of teeth. Our findings revealed that the mean distance from the center of the greater palatine foramen (GPF) to the midsagittal plane of the hard palate was 16.00 mm, and to the posterior border of the hard palate, 4.11 mm. The location of the GPF related to the maxillary molars was expressed as percentage in 5 relations. We found that the most common location of the GPF was between the maxillary second and third molars (relation III: 48%), and less common was lingual to the maxillary third molar (relation IV: 33.5%). The usually accepted description of the GPF location was lingual to the second molar (relation II), but in our study this relative position occurred in only 17% of the skulls. The long axis of the greater palatine canal directing to the GPF in the oral cavity was found to be directed anteriorly in 181 openings (90.5%) of the 200 GPF, and only 19 openings (9.5%) directed vertically. The bilateral symmetry of GPF on both sides of each skull was remarkable. The discrepancy of our observations on the Chinese skulls from those on other ethnic groups was discussed. Our findings suggest, therefore, the existence of an ethnic variation and the necessity of a more accurate method of locating the GPF in clinical practice.

Anatomy, Regional↗