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Biomedical subjects

C C Lai

Publications and source records attributed to C C Lai.

At least 19 recordsLinked to original sources
PubMed2007

Skin and soft tissue infection caused by non-tuberculous mycobacteria.

SETTING: A medical centre in Taipei, Taiwan. OBJECTIVE: To investigate the trend and characteristics of patients with non-tuberculous mycobacteria (NTM) related skin and soft tissue infection. DESIGN: A total of 63 patients with culture-proven diseases were identified from January 1997 to December 2004. The medical records of all patients were reviewed. RESULTS: Twenty-seven patients were infected with rapidly growing mycobacteria (RGM), 19 with Mycobacterium marinum, six with M. avium complex (MAC), five with M. kansasii and six with other species. Most patients presented with a protracted cutaneous lesion without systemic symptoms, and two thirds of the patients had a history of exposure. Seventy-three per cent of the lesions involved the extremities. Underlying illness with suppressed immunity was documented in 30.2% of the patients, and was most prevalent in patients with MAC (100%) and M. kansasii (60%). Of the patients, 62% underwent at least one surgical intervention, and 77.8% received treatment with different antimicrobial combinations. Most patients (86%) recovered completely. Granulomatous inflammation was found in 88.9% of biopsied tissue associated with M. marinum infection, 31.8% with RGM and 25.0% with MAC. CONCLUSION: A combination of surgery and antimicrobials cured most patients with microbiologically proven localised NTM skin and soft tissue infection.

Adolescent↗
PubMed2006

Disease caused by non-tuberculous mycobacteria in a university hospital in Taiwan, 1997-2003.

From January 1997 to December 2003, all patients with non-tuberculous mycobacteria (NTM) isolation who were treated at a university hospital in Taiwan were evaluated. Among the 2650 NTM isolates, 1225 (46.2%) were from 412 patients with clinically significant diseases. The annual incidence (per 100000 patients) of disease caused by NTM was 8.96 in 1997, 21.53 in 2002, and 16.55 in 2003. The major types of infections caused by NTM included isolated pulmonary infection and pleurisy (59.5%), skin/soft-tissue infections and osteomyelitis (13.8%), and disseminated diseases (13.3%). The two most common groups of organisms involved were rapidly growing mycobacteria (RGM) (41.4%) and Mycobacterium avium complex (MAC) (39%). The most common organism involved in isolated pulmonary infection and pleurisy was MAC (44.1%). RGM predominated in keratitis (94%), skin/soft-tissue infections and osteomyelitis (43.9%), and lymphadenitis (66.7%). This retrospective 7-year study demonstrated an increase in the incidence of NTM disease in a university hospital.

Adult↗
PubMed2005

Double-clad Cr4+:YAG crystal fiber amplifier.

A novel double-clad Cr4+:YAG crystal fiber is demonstrated by use of a codrawing laser-heated pedestal growth method. Up to 10 dB of gross gain at a wavelength of 1.52 microm is achieved at a pump power of 0.83 W, which, to our knowledge, is the first Cr4+-doped fiber amplifier in the optical fiber communication band.

Journal Article↗
PubMed2005

An intelligent tutoring system for trauma management (Trauma-Teach): a preliminary report.

Trauma-Teach is an interactive software for tutoring surgical trainees on medical trauma management procedures. Users of the system interact with a virtual patient suffering from trauma injuries. The task of the user is to stabilise the virtual patient, discover the underlying injuries and decide on an appropriate management plan. Artificial intelligence techniques are used to simulate the patient's pulmonary and cardiovascular systems in real time, determine the responses and results of treatments and diagnostics accordingly, model the patient deterioration if wrong actions are taken, and give a measure of reality to the system by selecting actual trauma cases from the hospital's database.

Artificial Intelligence↗
PubMed2003

Quality of life in patients of nasopharyngeal carcinoma: validation of the Taiwan Chinese version of the EORTC QLQ-C30 and the EORTC QLQ-H&N35.

The authors followed the guidelines of translation and pilot testing of the EORTC QLQ-C30 and EORTC-QLQ-H&N35 questionnaires. The questionnaires were given to 50 nasopharyngeal carcinoma patients under active treatment and 50 under follow-up at our institution from November 2000 to June 2001. A retest was conducted 2 weeks after the first interview/form completion for the follow-up group. The intraclass correlation coefficients of the two questionnaires were moderate to high in the follow-up group. Cronbach's alpha coefficients of all scales of the two questionnaires were > or = 0.70 except that of cognitive functioning. Correlation of scales measuring similar dimensions of the QLQ-C30 and the SF-36 were moderate to high, while that of the QLQ-H&N35 and the QLQ-C30 and the SF-36 were moderate to low. Patients in the active treatment group had more serious acute problems due to disease and chemotherapy. Patients in the follow-up group had more serious chronic problems due to radiation therapy. We concluded that the Taiwan Chinese version of the EORTC QLQ-C30 and the EORTC QLQ-H&N35 had moderate to high test-retest reliability, high internal consistency in most scales, and could show the expected differences between patients in active treatment and follow-up group.

Adult↗
PubMed2002

Sympathoinhibitory action of nociceptin in the rat spinal cord.

1. Whole-cell patch recordings were made from antidromically identified sympathetic preganglionic neurons (SPN) of immature rat spinal cord slices. Bath application of nociceptin (0.1-1 micromol/L) suppressed excitatory postsynaptic potentials (EPSP) and hyperpolarized a population of SPN; these effects were naloxone (1 micromol/L) insensitive. 2. Nociceptin suppressed the amplitude of EPSP without causing a concomitant change in glutamate-induced depolarizations, suggesting a presynaptic inhibitory action. 3. Analysis of current-voltage relationships showed that nociceptin hyperpolarized SPN by increasing an inwardly rectifying K+ current. 4. Intrathecal injection of nociceptin (3, 10 and 30 nmol) to urethane-anaesthetized rats dose-dependently reduced the mean arterial pressure and heart rate; these effects were not prevented by prior intravenous injection of naloxone (1 mg/kg). 5. Results from our in vitro and in vivo experiments suggest that nociceptin suppresses spinal sympathetic outflow either by attenuating excitatory synaptic responses or hyperpolarizing SPN.

Adrenergic Fibers↗
PubMed2001

Rapid monitoring assay of congenital adrenal hyperplasia with microbore high-performance liquid chromatography/electrospray ionization tandem mass spectrometry from dried blood spots.

17-hydroxyprogesterone (17OHP) is the most important plasma parameter for diagnosing and monitoring congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency. A rapid, simple, and specific method based on microbore high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (micro-HPLC/ESI-MS/MS) was developed to determine the presence of 17OHP on dried filter-paper blood samples from patients with CAH caused by 21-hydroxylase deficiency. 17OHP from dried blood spots formed by the action of Girard reagent P (GirP) turned out to be a water-soluble hydrazone complex. Derivatization with GirP led to higher ESI sensitivity for 17OHP. The LC/MS/MS detection of GirP-derivatized 17OHP (GirP-17OHP) was rapid (<3 min). The method is repeatable and reproducible, with CVs <7% and 12%, respectively. This new method was used for direct determination of 17OHP in dried blood specimens obtained from abnormal children and infants of various ages with a detection limit of 10 ng/mL ( approximately 12 microL blood). The method described allows for rapid and reliable measurements of 17OHP in dried blood specimens from patients affected by CAH.

17-alpha-Hydroxyprogesterone↗
PubMed2001

Induction of heme oxygenase-1 by Ginkgo biloba extract but not its terpenoids partially mediated its protective effect against lysophosphatidylcholine-induced damage.

In this study, we examined whether Ginkgo Biloba Extract and its terpenoid constituents protect against oxidative stress through actions on heme oxygenase (HO) gene expression and activity. HO-1 and glutathione peroxidase (GPx) gene expressions were examined by reverse transcription polymerase chain reaction (RT-PCR) analysis, HO activity and GPx enzyme activity were analysed by spectrophotometric assay. Pretreatment of H9c2 myocytes with 100-500 microgml(-1)Ginkgo Biloba Extract caused induction of HO-1 gene expression and a significant increase in HO activity; 30 microgml(-1)ginkgolide B and 30 microgml(-1)bilobalide had little effect. Treatment with Ginkgo Biloba Extract for 24 h also significantly increased GPx gene expression and GPx enzyme activity. Pretreatment with Ginkgo Biloba Extract, ginkgolide B and bilobalide protected myocytes against lysophosphatidylcholine (LPC)-induced damage. The protective effect of Ginkgo Biloba Extract against LPC-induced damage was partially suppressed by a HO inhibitor, Zinc protoporphyrin-IX (ZnPP-IX), while ZnPP-IX did not suppress the protective effect of ginkgolide B or bilobalide. Furthermore, pretreatment with hemin, biliverdin or bilirubin reduced cytotoxicity induced by LPC. These results suggest that induction of HO-1 by Ginkgo Biloba Extract but not its terpenoid constituents may play a beneficial role in oxidative stress. The mechanism of Ginkgo Biloba Extract-induced HO-1 gene expression and the increase in HO activity may be related to alteration of intracellular glutathione levels.

Animals↗
PubMed2001

Antimicrobial activity of four root canal sealers against endodontic pathogens.

The antibacterial effects of various types of widely used endodontic sealers have not been compared systematically on facultative or obligate anaerobic endodontic pathogens. The aim of this study was to evaluate the antimicrobial properties of four commonly used endodontic sealers: two epoxy-resin-based sealers (AH26, AH plus), one zinc-oxide eugenol-based sealer (N2), and one calcium hydroxide-based sealer (Sealapex). The testing microbes were four facultative anaerobic species (Streptococcus mutans, Streptococcus sanguis, Escherichia coli, and Staphylococcus aureus) and four obligate anaerobic species (Porphyromonas gingivalis, Porphyromonas endodontalis, Fusobacterium nucleatum, and Prevotella intermedia). The freshly mixed sealers were placed into the prepared wells of agar plates inoculated with the test microorganisms. After varying periods of incubation (2 days for facultative anaerobic species and 7 days for obligate anaerobic species), the zones of growth inhibition were observed and measured. All the sealers were distinctly different from each other in their antimicrobial activity. The sealers showed different inhibitory effects depending on the types and bacterial strains. N2 containing formaldehyde and eugenol proved to be the most effective against the microorganisms. The extreme antimicrobial potency of this root canal sealer must be weighted against its pronounced tissue toxic effect.

Analysis of Variance↗
PubMed2001

Malignant melanoma of the eustachian tube.

The case report describes the diagnosis and the management of malignant melanoma of the eustachian tube. This is an exceedingly rare condition that was treated with endoscopic surgery and post-operative radiotherapy. During a 15-month follow-up, there was no evidence of recurrence.

Ear Neoplasms↗
PubMed2001

Gender difference in cytoprotection induced by estrogen on female and male bovine aortic endothelial cells.

Before menopause, women have a lower risk of cardiovascular diseases than men. Studies attribute this gender difference to estrogenic protection in the female cardiovascular system. We have demonstrated that 17beta-estradiol (E2) protects female bovine aortic endothelial cells against oxidative injury, probably through the induction of antioxidant enzyme activities. In this study, we examined whether E2 confers a differential protection on male and female cells. Bovine aortic endothelial cells from both genders were preconditioned for 24 h with E2 (1 nM to 10 microM), and their resistance to paraquat (1 mM, 3 h), a superoxide generator, was measured using an MTT assay. In contrast to the protection observed in female bovine aortic endothelial cells, there was no protective effect by E2 on male bovine aortic endothelial cells at physiologic concentrations. However, E2 at 1-10 microM attenuated paraquat's toxicity in both male and female cells, probably through its direct antioxidant activity. E2 at 1 nM increased in female, but not in male, cells the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, which was associated with decreased levels of reactive oxygen species during subsequent paraquat exposure. This suggests that antioxidant enzyme induction plays some role in E2-augmented oxidative resistance in female endothelial cells.

Animals↗
PubMed2001

Suppression of choroidal neovascularization by adeno-associated virus vector expressing angiostatin.

PURPOSE: To test the efficacy of a recombinant adeno-associated virus (rAAV) vector that expresses mouse angiostatin in suppressing experimental choroidal neovascularization (CNV) in a rat model. METHODS: An rAAV vector, rAAV-angiostatin, was constructed to deliver the mouse angiostatin gene. rAAV-angiostatin and a control virus, rAAV-lacZ, were delivered in vivo by subretinal injection in Brown Norway rats, and the delivery was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR). For a CNV suppression experiment, CNV was generated by fundus krypton laser photocoagulation 7 days after the viral vector injection and was evaluated by fluorescein angiography (FA) and histology. Apoptosis in retina was analyzed using the TUNEL assay. Inflammation in the retina was investigated by immunohistochemistry, using antibodies that recognize lymphocytes. RESULTS: rAAV-angiostatin injection led to sustained expression of the angiostatin gene in chorioretinal tissue for up to150 days. FA analysis revealed significant reduction of the average sizes of CNV lesions in rAAV-angiostatin-injected eyes when compared with rAAV-lacZ-injected eyes at both 14 (P = 0.019) and 150 (P = 0.010) days after injection. Moreover, histologic analysis of CNV lesions also revealed significantly smaller lesions in rAAV-angiostatin-injected eyes (P = 0.004). As for adverse effects, rAAV-angiostatin injection did not cause inflammation or apoptosis of cells in retina and choroid. CONCLUSIONS: This is the first report that subretinal injection of rAAV-angiostatin can significantly reduce the sizes of CNV lesions. This and the absence of apoptosis and inflammation in chorioretinal tissue indicate the feasibility of a gene therapy approach for treatment of CNV disease.

Angiostatins↗
PubMed2001

Pulmonary function during exercise in obese children.

BACKGROUND: Obesity imposes additional stress to ventilation during exercise. The purpose of this study is to evaluate the pulmonary function changes with graded exercise and the habitual level of physical activity in obese children. METHODS: This study recruited 42 obese and 10 normal students, aged 11, from Tamsui Elementary School. Measurements of cardiopulmonary fitness were recorded after a jump rope test. Height, weight and body mass indices were determined before testing. RESULTS: A significant correlation was found between triceps skin-fold thickness and the body mass index (BMI; r = 0.65, p < 0.05). Blood systolic pressure significantly increased in the obese subjects in their post-exercise test. There was no significant difference between the obese and the non-obese groups in any of the lung function test measurements. Forced expiratory volume in the first second (FEV1), peak expiratory flow rate (PEFR) and forced vital capacity (FVC) were similar in both groups. CONCLUSIONS: Physiologic responses are not sufficiently different from between the obese subjects and the non-obese children. We should pay more attention to fostering confidence in the obese child exercise.

Child, Preschool↗
PubMed2001

Ocular ischemic syndrome.

BACKGROUND: The purpose of this study was to investigate the clinical features and management of ocular ischemic syndrome (OIS) and factors influencing its development. METHODS: Ten patients (12 eyes) with OIS underwent detailed medical and ocular histories, complete ophthalmic evaluation including fluorescein angiography, internal carotid artery evaluation by duplex ultrasonography, and management. The following outcome measures were considered: visual acuity, anterior segment neovascularization, lens status, retinal and choroidal changes, and carotid artery stenosis or occlusion. RESULTS: The mean age of the patients was 63 +/- 8 years. Presenting visual symptoms included gradual (82.5%) or sudden (17.5%) onset of vision loss. At initial visit, eyes with OIS had visual acuity less than or equal to counting fingers in 50%, iris neovascularization in 58%, and neovascular glaucoma in 42%. Initially associated systemic diseases in these patients included arterial hypertension (60%), diabetes mellitus (40%), coronary artery disease (20%), previous stroke (30%) and hemodialysis (10%). Complete occlusion or severe occlusion (70-99%) of the internal carotid artery was seen in 75% on the side of OIS. Panretinal photocoagulation did not prevent OIS from progressing but vitreous hemorrhage and rubeosis iris regressed. Carotid endarterectomy had some benefit in stabilizing or improving vision in patients with OIS. CONCLUSION: OIS has a poor visual prognosis. It is imperative that the clinician be aware of the signs and symptoms of carotid disease in order to facilitate prompt diagnosis and appropriate referral, because OIS may be the presenting sign of serious ischemic cerebrovascular and ischemic heart disease.

Adult↗
PubMed2001

A rapid and successful treatment for airbag-related traumatic macular hole.

A 28-year-old female was diagnosed as having an airbag-related traumatic macular hole in the right eye 9 days subsequent to a traffic accident. Four weeks after the trauma, the patient's visual acuity was deteriorating to 20/600. Following vitrectomy, membrane peeling, use of autologous serum and intraocular gas tamponade, the hole healed within 12 days, more rapidly than the expected interval for the treatment of a traumatic macular hole. The visual acuities at the 3-month and 1-year follow-up examinations were 20/50, much better than the conventional surgical treatment of idiopathic macular hole and comparable to previous reports of the treatment of traumatic macular hole. Vitrectomy procedure has been proved to be effective for the treatment of traumatic macular hole. Vitrectomy combined with membrane peeling, autologous serum and intraocular gas tamponade can heal the traumatic macular hole more rapidly than the conventional treatment with vitrectomy only.

Accidents, Traffic↗
PubMed2000

Bovine papillomavirus E5 protein induces the formation of signal transduction complexes containing dimeric activated platelet-derived growth factor beta receptor and associated signaling proteins.

The bovine papillomavirus E5 protein binds to the cellular platelet-derived growth factor (PDGF) beta receptor, resulting in constitutive activation of the receptor and cell growth transformation. By subjecting extracts from E5-transformed or PDGF-treated cells to velocity sedimentation in sucrose gradients, activated PDGF beta receptor complexes were separated from monomeric, inactive receptor. Rapidly sedimenting activated complexes contained oligomeric (apparently dimeric), tyrosine-phosphorylated PDGF beta receptor, the E5 protein, and associated cellular signaling proteins including the p85 subunit of phosphoinositol 3'-kinase, phospholipase Cgamma, and Ras-GTPase activating protein. These signaling proteins made the major contribution to the increased sedimentation rate of the activated receptor complexes. Pairwise analysis of components of these complexes indicated that multiple signaling proteins and the E5 protein were simultaneously present in the activated complexes. Our results also showed that the E5 protein and PDGF activated only a small fraction of the total PDGF beta receptor, that not all receptor molecules associated with the E5 protein were tyrosine-phosphorylated, and that signaling proteins could bind to hemiphosphorylated receptor dimers. On the basis of these results, we propose a model for the assembly of multiprotein, activated PDGF beta receptor complexes in response to the E5 protein.

Bovine papillomavirus 1↗
PubMed2000

Analysis of a commercial preparation of erythromycin estolates by tandem mass spectrometry and high performance liquid chromatography/electrospray ionization tandem mass spectrometry using an ion trap mass spectrometer.

Because of the lack of a UV chromophore and their much smaller abundances in comparison with the major component, the minor components in erythromycin estolate preparations are difficult to analyze by high performance liquid chromatography ultraviolet (HPLC-UV). Tentative assignment of the major and minor components can be achieved with the combination of full scan and ZoomScan using an ion trap mass spectrometer. Tandem mass spectrometry (MS/MS) provided an effective method to quickly identify most components without chromatographic separation, and all the related compounds, except the isobaric pair ECE and PdMeEA, could be identified in this way. The best result was obtained by using liquid chromatography/tandem mass spectrometry (LC/MS/MS) operated in selected reaction monitoring mode. The major compound, the estolate of erythromycin A (EAE), and seven other minor components, could be separated and identified, with semiquantitative estimates of relative concentrations.

Anti-Bacterial Agents↗