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L C Cheng

Publications and source records attributed to L C Cheng.

At least 19 recordsLinked to original sources
PubMed2006

Foreign body-induced aorto-oesophageal fistula: a review of five cases and their management.

Foreign body-induced aorto-oesophageal fistula is a rare cause of massive upper gastro-intestinal bleeding and, in the absence of a timely diagnosis and surgical intervention, can be fatal. During a period of 25 years, five patients with foreign body-induced aorto-oesophageal fistula underwent surgery in our department. Three patients survived. All survivors required more than one surgical intervention. The clinical course of these five patients and the management of this potentially fatal condition are reviewed.

Adult↗
PubMed2005

Long-term anticoagulation therapy and thromboembolic complications after the Fontan procedure.

BACKGROUND: The necessity for chronic anticoagulation of Fontan patients remains controversial. We determined the prevalence of thromboembolic complications after the Fontan procedure in relation to different long-term anticoagulation strategies. METHODS: The clinical outcomes, postoperative anticoagulation strategies and occurrence of thromboembolic complications in 102 ethnic Chinese patients who had undergone Fontan procedure between 1980 and 2002 were reviewed. RESULTS: The early and late surgical mortalities, all unrelated to thromboembolism, were 10.8% (11/102) and 5.8% (6/104), respectively. Of the 85 survivors, 46 (54%) were maintained on long-term warfarin therapy, 8 (9%) on aspirin prophylaxis while 31 (37%) were not on chronic anticoagulation. Four (4.5%) patients, two with and two without warfarin prophylaxis, developed thromboembolic complications at 0.14 to 7.7 years after the Fontan procedure (0.74%/patient-year). Three had a grossly dilated right atrium after atriopulmonary connection, two of whom had atrial fenestrations. The other had atrial tachycardia. Freedom from development of thromboembolic complications (mean+/-S.E.) at 1, 5 and 10 years after surgery was 97+/-19%, 96+/-2.5% and 92+/-4.2%, respectively. When compared with those on long-term warfarin therapy, patients without chronic anticoagulation were followed-up longer (p=0.001), more likely to have undergone atriopulmonary connection (p<0.001), less likely to have fenestrations (p=0.02) and cardiac arrhythmias (p=0.02) but not predisposed to increased risk of thromboembolism (p=1.00). CONCLUSION: The study supports the contention that chronic anticoagulation may not be required for majority of ethnic Chinese Fontan patients. Nonetheless, it may perhaps be considered in those with grossly dilated right atrium, cardiac arrhythmias and residual right-to-left shunts.

Anticoagulants↗
PubMed2003

Gender difference in self-esteem of Hong Kong Chinese with cardiac diseases.

Self-esteem is an indicator of a person's subjective quality of life due to its close relationship to a person's behavioural competence, positive self-experience, and sense of self-actualization. The present study aimed to investigate the basis of self-esteem in people with cardiac diseases, according to gender, after their cardiac surgery. The findings showed that there were prominent gender differences in the subjects' self-esteem. Women (aged<60) showed statistically significant higher ratings in the importance of 11 life events importance and the satisfaction of three life events than men. The study also found cultural uniqueness: Hong Kong Chinese (both men and women) with cardiac diseases generally indicated that social (interpersonal) self-concept dimensions were more important than achievement (personal) self-concept dimensions in their life perception. These findings are noteworthy for setting optimum goals of rehabilitation apart from return to work.

Adaptation, Psychological↗
PubMed2002

Differential influences of various arsenic compounds on glutathione redox status and antioxidative enzymes in porcine endothelial cells.

The cellular response and detoxification mechanisms in porcine endothelial cells (PAECs) to arsenic trioxide (As2O3), sodium arsenite (NaAsO2) and sodium arsenate (Na2HAsO4) were investigated. NaAsO2 at 20 microM for 72 h increased Cu/Zn superoxide dismutase activity resulting in elevated intracellular hydrogen peroxide levels, but As2O3 and Na2HAsO4 did not. Trivalent arsenic compounds increased intracellular oxidized glutathione (GSSG) and total glutathione (GSH) and cellular glutathione peroxidase (cGPX) and glutathione S-transferase (GST) activity, but not glutathione reductase activity. The increased cGPX activity resulted in an elevated cellular GSSG content. Na2HAsO4 increased the cellular GSSG level at 72 h compared to controls. These results imply that the increased GSH content responding to the oxidative stress by trivalent arsenic compounds may be mainly related to the regulation of GSH turnover. The increased GST activity implies that the elevated intracellular GSH level responding to the oxidative stress may be used to conjugate arsenic in PAECs and facilitate arsenic efflux.

Animals↗
PubMed2001

C. elegans CED-12 acts in the conserved crkII/DOCK180/Rac pathway to control cell migration and cell corpse engulfment.

We have identified and characterized a novel C. elegans gene, ced-12, that functions in the conserved GTPase signaling pathway mediated by CED-2/Crkll, CED-5/DOCK180, and CED-10/Rac to control cell migration and phagocytosis of apoptotic cells. We provide evidence that ced-12 likely acts upstream of ced-10 during cell migration and phagocytosis and that CED-12 physically interacts with CED-5 and forms a ternary complex with CED-2 in vitro. We propose that the formation and localization of a CED-2-CED-5-CED-12 ternary complex to the plasma membrane activates CED-10, leading to the cytoskeletal reorganization that occurs in the polarized extension of cell surfaces in engulfing cells and migrating cells. We suggest that CED-12 counterparts in higher organisms regulate cytoskeleton dynamics, as CED-12 does in C. elegans.

Amino Acid Sequence↗
PubMed2001

Severe mitral regurgitation due to mitral valve prolapse associated with Bland-White-Garland syndrome.

Bland-White-Garland syndrome refers to the rare congenital cardiac abnormality whereby the left coronary artery arises from the pulmonary artery. The natural history of this condition is highly variable, ranging from death in early infancy to asymptomatic adult survival. It is sometimes diagnosed in adults with mitral regurgitation thought to be of ischaemic origin. We report a case of a 29-year-old man with Bland-White-Garland syndrome and concomitant mitral valve prolapse, and review the literature on the appropriate investigations and management of this abnormality. Recognition and diagnosis of this condition is important because of the potentially life-threatening complications, which may be prevented by surgical intervention.

Adult↗
PubMed2000

Triploid pregnancy after ICSI of frozen testicular spermatozoa into cryopreserved human oocytes: case report.

Although freezing oocytes is ethically more acceptable than cryopreservation of embryos, variable oocyte survival, fertilization rate and possible risk of increased ploidy after cryopreservation have precluded the widespread clinical application of oocyte cryopreservation in assisted reproduction techniques. We report a triploid pregnancy from intracytoplasmic sperm injection of recombinant FSH-stimulated frozen/thawed testicular spermatozoa into cryopreserved oocytes in a hormone replacement cycle. To our knowledge, this is the first report of a pregnancy where both gametes have been frozen. It illustrates the need for further research when applying new techniques in assisted reproduction.

Abortion, Missed↗
PubMed2000

The ultrasound diagnosis of retained fetal bones in West African patients complaining of infertility.

Prolonged retention of intrauterine bone is a recognised cause of secondary infertility. Between 1989 and 1995, eleven West African women had retained intrauterine bone as the cause of their infertility. All the women had had termination of pregnancies in their countries of origin. Transvaginal ultrasound scan detected bright intrauterine echoes suggestive of bone which was confirmed and removed at hysteroscopy. Subsequently eight women conceived spontaneously 12 pregnancies. Doctors treating West African women with infertility should be aware of this condition and include transvaginal ultrasound scan in their investigations.

Abortion, Incomplete↗
PubMed2000

A rare complication of PTCS: ruptured balloon with retained broken catheter.

This report describes a rare situation in which a retained ruptured balloon with broken catheter was caught in an incompletely opened stent during a percutaneous transluminal coronary stenting (PTCS) procedure in a 84 year old gentleman. A short, warm heart bypass and single cross clamping coronary artery bypass grafting procedure was performed.

Aged↗
PubMed1999

Left ventricular rupture after mitral valve replacement.

BACKGROUND: What are the immediate and long term outcomes of patients who had rupture of the left ventricle after mitral valve replacement? METHODS EXPERIMENTAL DESIGN: A retrospective study with a 20-year follow-up. SETTING: Experience in a single tertiary referral cardiothoracic surgery hospital. PARTICIPANTS: 20 out of 3105 patients that received mitral valve replacement. INTERVENTION: All these 20 patients received re-exploration for a trial of repair of left ventricular rupture either by an internal or an external or a combined repair. MEASURES: Operative mortality and long term outcome of the survivals. RESULTS: Most patients (16.80%) were female and had rheumatic mitral valve disease. The mean age of the patients was 58.1 years. All patients underwent attempted repair, usually by removal of the prosthesis and reconstitution of the ventricle from within the left atrium (75%). Thirteen (65%) patients died. Two late deaths were of unrelated cause. One surviving patient developed a late ventricular false aneurysm but did not undergo repeat surgery. One patient developed severe mitral regurgitation due to tissue failure of the bioprosthesis 12 years after surgery and she underwent a successful reoperation. CONCLUSIONS: We believe that all patients should be placed back on cardiopulmonary bypass for an internal repair. The long term outcome of the survivals is satisfactory.

Female↗
PubMed1998

Where's the point?

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Anesthetics, Local↗
PubMed1998

Surgical resection of pulmonary metastases.

BACKGROUND: To review the results of complete surgical resection of pulmonary metastasis -- a ten-year experience. SETTING: Retrospective analysis of all patients with lung secondaries who received complete surgical resection of pulmonary metastases (from 1984 to 1995) in Grantham Hospital, Hong Kong. Sixty patients over a 10-year period were studied. METHODS: Eighty thoracotomies were performed with 88 tumour nodules excised. The follow-up period ranged from 5 months to 111 months. RESULTS: Thirteen (14.8%) specimens were found to have tumour size greater than 5.0 cm. This may reflect late detection of metastatic tumour and probably accounts for the higher percentage of our patients receiving more major lung resections (63.3%) than just wedge resections (36.6%). The mean survival period for the subgroup with hepatocellular carcinoma was 28.2 months and for the nasopharyngeal carcinoma group was 25 months. The mean survival of the whole group was 26.4 months. CONCLUSIONS: The favourable outcome for hepatocellular carcinoma and nasopharyngeal carcinoma could be due to the result of selection of patients with more favourable prognosis for surgery. The latent period, using 12 months as a break-off point, did not affect patient survival in our study.

Adolescent↗
PubMed1997

Preclinical evaluation of drug-drug interaction potential: present status of the application of primary human hepatocytes in the evaluation of cytochrome P450 induction.

Cytochrome P450 (CYP) inhibition and induction are the key mechanisms in drug-drug interactions. Aside from clinical studies, primary human hepatocytes may represent the most appropriate experimental system for the evaluation of CYP induction in humans. A consensus of an international panel on the present status and future research directions in the application of primary human hepatocytes in the evaluation of CYP-induction is presented here. The following observations are concluded to be generally true: (1) Human hepatocytes isolated from both biopsy samples and transplantable livers are suitable for induction studies. (2) Hormonally-defined media can be used for the evaluation of CYP induction. (3) Isozyme-selective induction of CYP1A and 3A by known inducers are observed. (4) Reproducibility of induction could be improved by using hepatocytes plated as confluent cultures. (5) Induction could be observed for hepatocytes treated at 1-3 days after culturing. (6) Treatment duration of 2 days in general leads to near maximal induction. (7) In general, there is a good qualitative correlation between human hepatocyte results in vitro and clinical observations in vivo. (8) When the same inducers were evaluated in independent laboratories, similar data were generally observed. We conclude that primary human hepatocytes represent an appropriate model for mechanistic evaluation of CYP induction and as a screening tool for CYP induction potential of xenobiotics. A set of data acceptance criteria are proposed: (1) Positive response should be observed with concurrent positive control chemicals; (2) reproducible observation should be observed with multiple human donors; (3) for negative response, the doses used should not be cytotoxic; and (4) replicate treatment and/or multiple dose treatment should be performed to allow statistical analysis. Future studies should include the further development of on: (1) The inducibility of CYP isozymes other than CYP1A and 3A, and phase II enzymes; (2) further development of culturing condition to allow optimal gene expression; (3) evaluation of the involvement of nonparenchymal cells on CYP induction of parenchymal cells; (4) the and validation of quantitative approaches to extrapolate in vitro data to in vivo data; (5) evaluation of possible individual variations and potential genetic polymorphism in inducibility; (6) further definition of species differences in CYP induction; (7) development of a 'normal' human hepatocyte cell line for CYP induction studies; (8) improvement of cryopreservation procedure of human hepatocytes; (9) definition of the molecular mechanisms of CYP induction; and (10) evaluation of the induction of phase II metabolic pathways.

Cells, Cultured↗
PubMed1997

Adolescents' and providers' perspectives on the need for and use of mental health services.

PURPOSE: This study examines need for and use of services from both the adolescent's and the service provider's viewpoints. METHODS: The Youth Services Project interviewed 792 youths from the juvenile justice, education, primary health care, and child welfare sectors (200 each); gathered anonymous tallies of the mental health of youthful clients at each sector; and conducted focus groups with providers. RESULTS: A high percentage of youths (12-15%) met DSM-IV criteria for a mental health disorder, yet the sector clients were not identified as having mental health problems. Juvenile justice and child welfare sectors identified the highest percentage of adolescent clients as having mental health problems, and provided the most services (50-80%). The primary health care sector recorded no mental health disorders among the tallied clients, and provided the fewest mental health services (< 20%). Providers' complaints that they lacked knowledge concerning mental health assessment and lacked referral or treatment resources closely paralleled the degree to which their sector underserviced youths. CONCLUSION: Lack of knowledge about the extent of need in adolescents, methods for assessing or treating, and referral resources handicap service providers and explain the gap between need and service.

Adolescent↗
PubMed1997

Gene sequence and expression of an analog of proliferating cell nuclear antigen (PCNA) in the alga Tetraselmis chui and detection of the encoded protein with anti-rat PCNA monoclonal antibody.

To identify a phytoplankton cell cycle marker detected by a monoclonal antibody against mammalian proliferating cell nuclear antigen (PCNA) (S. Lin, J. Chang, and E. J. Carpenter, J. Phycol. 30:449-456, 1994), a PCNA gene fragment was isolated by reverse transcription-PCR from the marine unicellular alga Tetraselmis chui Butcher (Prasinophyceae). The gene fragment was 616 bp in length and contained an open reading frame of 205 amino acids. The deduced amino acid sequence showed 80 and 88% similarity to human and rice PCNA, respectively. Southern hybridization indicated that the isolated gene fragment was part of the T. chui genome, with up to three copies in each haploid nucleus. Northern hybridization was used to detect a PCNA mRNA with a size of 1.2 kb from an exponentially growing algal culture. The T. chui gene fragment has been cloned into an expression vector, and a fusion protein was subsequently generated. Anti-rat PCNA simultaneously recognized the PCNA fusion protein and a single 33-kDa band in T.chui total protein extract. Our results indicate that T. chui PCNA is highly similar to its mammalian counterpart and that anti-rat PCNA is a good tool for detecting phytoplankton PCNA in general.

Amino Acid Sequence↗
PubMed1996

Surgical resection of pulmonary metastases from nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC), unlike other head and neck cancers,is known for its propensity for distant metastases. Chemotherapy remains the mainstay of treatment because of this and the chemosensitivity of the tumour, but long-term control is rare. The surgical management of pulmonary metastases of other extrathoracic malignancies prompted this review of surgical management of patients with NPC. METHODS: Thirteen thoracotomies were performed in 12 patients with pulmonary metastases as the first and only site of relapse of nasopharyngeal carcinoma. Postoperative chemotherapy was given in four patients, radiotherapy to the mediastinum in one patient and both chemotherapy and radiotherapy in two patients. The survival pattern of this group of 12 patients was compared with a historical control group consisting of 65 patients without surgical resection. RESULTS: Lymph node involvement was documented in four patients during operation. Four patients relapsed after surgical resection, two of them were from the group of three patients with lymph node involvement. The site of subsequent relapse was the lung for three patients and the skeletal system for the fourth. The 2 year actuarial survival of the surgically resected group compared favourably with the historical control group (80% and 24.1%, respectively; P=0.0002 by Mantel-Cox text). CONCLUSIONS: Surgical resection of pulmonary metastases from NPC seems to be a promising approach thought the effect of case selection cannot be excluded and further studies are indicated. The importance of exploration and dissection of mediastinal nodes in the surgical management of pulmonary metastases from NPC was demonstrated.

Actuarial Analysis↗
PubMed1996

Minimally invasive surgery: video endoscopic thoracic sympathectomy for palmar hyperhidrosis.

Palmar hyperhidrosis (PH) is a common disorder in Taiwan. It often causes social embarrassment and occupational handicaps. So far, there has been no satisfactory treatment for PH. In 1990, we first developed a minimally invasive technique: video endoscopic sympathectomy to treat PH. The procedure has subsequently proven to be a standard treatment for PH. In this study, a survey of 9988 cases of PH patients from 17 hospitals in Taiwan treated by this method during the past 5 years is presented. Although there were some variations in the model of anaesthesia, technique and extent of sympathectomy, the postoperative results were generally satisfactory. Both sides of sympathectomy were mostly accomplished within half an hour in one stage. The operative scars were tiny and concealed in the axillary region. The patients were discharged from the hospital after an overnight stay. Complications such as pneumothorax, haemothorax (0.3%) or Horner's syndrome (0.1%) were rare. There was no surgical mortality in this series. The most common complication was compensatory hyperhidrosis which was usually mild to moderate and tolerable after reassurance. The recurrence rate of PH was approximately 1% in the first year and less than 3% during the 3 years of follow up. Intraoperative monitoring of palmar skin temperature (PST) was advocated to confirm an adequate sympathectomy warranting a definite result. En bloc ablation of T2 segment invariably resulted in a rise of PST to about 2 degrees C and was considered as an adequate extent of sympathectomy for PH. The refined technique was extended to treat young children with PH and patients with craniofacial hyperhidrosis. The therapeutic results were generally excellent with minimal morbidity and rare recurrence. It is concluded that video endoscopic en bloc T2 sympathectomy is a simple, minimally invasive and effective treatment for both adults and children with PH and also for patients with craniofacial hyperhidrosis.

Adolescent↗