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Biomedical subjects

F Wong

Publications and source records attributed to F Wong.

At least 73 records · Page 4Linked to original sources
PubMed2000

Haemodynamic, renal sodium handling, and neurohormonal effects of acute administration of low dose losartan, an angiotensin II receptor antagonist, in preascitic cirrhosis.

BACKGROUND: The renin-angiotensin system may be implicated in the subtle sodium handling abnormality in preascitic cirrhosis. AIMS: To assess the role of angiotensin II in sodium homoeostasis in preascitic cirrhosis, using losartan, its receptor antagonist. PATIENTS: Nine male, preascitic cirrhotic patients, and six age matched, healthy male controls. METHODS: A dose response study using 2.5, 5, 7.5, and 10 mg of losartan was performed on a daily 200 mmol sodium intake, followed by repeat studies with the optimal dose, 7.5 mg of losartan, to determine its effects on systemic and renal haemodynamics, renal sodium handling, and neurohumoral factors. RESULTS: Preascitic cirrhotic patients had significantly reduced baseline urinary sodium excretion compared with controls (154 (8) versus 191 (12) mmol/day, p<0.05), associated with significantly reduced systemic angiotensin II levels (6.0 (1.7) versus 39.5 (10.0) pmol/l, p=0.002). Losartan 7.5 mg normalised renal sodium handling in the preascitic cirrhotic patients (202 (12) mmol/day, p=0.05 versus baseline), without any change in systemic or renal haemodynamics, but with significantly increased systemic angiotensin II levels (7.8 (2.3) pmol/l, p=0.05 versus baseline). Losartan had no effect on renal sodium handling in controls. CONCLUSIONS: In preascitic cirrhotic patients, the subtle renal sodium retention, paradoxically associated with low systemic neurohumoral factor levels, is improved with low dose losartan, suggesting the involvement of angiotensin II via its direct action on the renal tubule.

Adult↗
PubMed2000

Operative laparoscopy versus laparotomy for the management of ectopic pregnancy.

OBJECTIVE: To compare the surgical managements for ectopic pregnancy. METHODS: In a retrospective analysis, we examined the trend of surgical procedures and the results of different management in 149 patients. RESULTS: The change from laparotomy to laparoscopic treatment was significant. The success rates of salpingostomy and salpingectomy under laparoscopy or laparotomy were 100%. No serious complications occurred. The operation time and length of hospital stay for laparoscopic salpingostomy were shorter than those for laparotomy with salpingostomy. CONCLUSION: Laparoscopic salpingostomy and laparoscopic salpingectomy are better than laparotomy in the treatment of ectopic pregnancy.

Adult↗
PubMed1999

Cell death in age-related macular degeneration.

The cellular and molecular mechanisms underlying the death of photoreceptors and other retinal cells in age-related macular degeneration (AMD) remain poorly understood. Some of the questions for which answers need to be sought, and which are explicitly or implicitly addressed in this article include: (1) how do patterns of cell death in AMD compare, qualitatively and quantitatively, with "normal" cell death in aging retinas, and with cell death in retinitis pigmentosa (RP) and its animal models; (2) is apoptosis involved in AMD; (3) is there any evidence that rods are necessary for cone survival; (4) if the answer is yes, is there evidence that rods produce one or more survival-promoting factor(s) that act directly on cones; (5) are the effects of rods upon cones exclusively mediated by diffusible factors, or do they also involve contact-mediated interactions; (6) is there any evidence that photoreceptors regulate the survival and/or function of RPE and Müller cells, as well as the interactions between these cells and cones; (7) are trophic factors and their receptors in the macula different from those in other parts of the retina; and (8) are toxic mechanisms involved in the onset and progression of cell death in AMD? Clear cut answers to most of these (and related) questions about cell death in AMD are not yet available. The goal of this article is to summarize discussion that should help in the formulation of suitable hypotheses, amenable to experimental analysis. To provide a platform for such discussion, we present an overview of progress made in recent years in the analysis of other retinal degenerations and of neuronal degenerations in other regions of the CNS. We conclude with an overview of concepts and speculation derived from our current research.

Aging↗
PubMed1999

32-Indolyl ether derivatives of ascomycin: three-dimensional structures of complexes with FK506-binding protein.

32-Indole ether derivatives of tacrolimus and ascomycin retain the potent immunosuppressive activity of their parent compounds but display reduced toxicity. In addition, their complexes with the 12-kDa FK506-binding protein (FKBP) form more stable complexes with the protein phosphatase calcineurin, the molecular target of these drugs. We have solved the three-dimensional structures of the FKBP complexes with two 32-indolyl derivatives of ascomycin. The structures of the protein and the macrolide are remarkably similar to those seen in the complexes with tacrolimus and ascomycin. The indole groups project away from the body of the complex, and multiple conformations are observed for the linkage to these groups as well as for a nearby peptide suggesting apparent flexibility in these parts of the structure. Comparison of these structures with that of the ternary complex of calcineurin, FKBP, and tacrolimus suggests that the indole groups interact with a binding site comprising elements of both the calcineurin alpha- and beta-chains and that this interaction is responsible for the increased stability of these complexes.

Crystallography, X-Ray↗
PubMed1999

Low-risk endometrial carcinoma: assessment of a treatment policy based on tumor ploidy and identification of additional prognostic indicators.

OBJECTIVES: The aims of this study were (1) to assess a treatment policy for patients with low-risk endometrioid endometrial carcinoma where adjuvant treatment decisions have been based on ploidy status of the tumor, and (2) to screen diploid, low-risk tumors for additional features of prognostic significance. METHODS: Between 01/1992 and 08/1996, 406 patients were referred to the B.C. Cancer Agency-Vancouver Clinic with typical endometrial adenocarcinomas limited to <50% myometrial invasion and no vascular space invasion or grade 3 disease on pathology review ("low-risk stage I endometrial carcinoma"). Patients were prospectively assigned to treatment groups based on tumor ploidy. Those patients with aneuploid tumors (n = 91) were treated with adjuvant vaginal vault radiotherapy while those with diploid tumors (n = 315) were followed and treated only at relapse. The hysterectomy specimens from all 14 patients in the untreated, diploid group who relapsed, as well as 28 stage- and grade-matched diploid controls who did not fail, were analyzed by immunohistochemical staining for estrogen receptor (ER), Bcl-2, and p53 proteins. RESULTS: There were no significant differences in the stage (Ia vs Ib) and grade (G1 vs G2) distribution for the diploid and aneuploid groups. Overall median age was 64 years (range 27-90 years) and was also not significantly different for the two groups. The median follow-up for the entire cohort is 45 months (range 1-76 months). There have been 14 failures in the diploid group and 4 failures in the aneuploid group with actuarial 5-year disease-free survival rates of 95.0 and 95.2%, respectively (P = NS). Eight of the failures in the diploid group occurred at the vaginal vault and were all subsequently salvaged with radiotherapy. All but 1 of the failures in the aneuploid group were considered incurable. Of the 14 diploid tumors from patients who failed, 7 stained positively for p53, compared to 4 of 28 diploid controls (P = 0.02). No significant differences were seen in the diploid tumors that recurred, compared to controls, with respect to Bcl-2 or ER expression. CONCLUSIONS: Patients with diploid, low-risk stage I endometrial cancers have excellent prospects for relapse-free and overall survival. Patients with aneuploid tumors treated with adjuvant radiotherapy have the same risk of relapse as untreated patients with diploid tumors; however, their ultimate survival may be lower as a smaller proportion of aneuploid failures are salvageable. While p53 expression in diploid tumors is associated with increased risk of relapse, Bcl-2 and ER are not useful prognostic indicators in this setting.

Adult↗
PubMed1999

Retinal rod photoreceptor-specific gene mutation perturbs cone pathway development.

Rod-specific photoreceptor dystrophies are complicated by the delayed death of genetically normal neighboring cones. In transgenic (Tg) swine with a rod-specific (rhodopsin) gene mutation, cone photoreceptor physiology was normal for months but later declined, consistent with delayed cone cell death. Surprisingly, cone postreceptoral function was markedly abnormal when cone photoreceptor physiology was still normal. The defect was localized to hyperpolarizing cells postsynaptic to the middle wavelength-sensitive cones. Recordings throughout postnatal development indicated a failure of cone circuitry maturation, a novel mechanism of secondary cone abnormality in rod dystrophy. The results have implications for therapy for human retinal dystrophies and raise the possibility that rod afferent activity plays a role in the postnatal maturation of cone retinal circuitry.

Amino Acid Substitution↗
PubMed1999

Development of basic nursing education in China and Hong Kong.

Hong Kong returned to the sovereignty of the People's Republic of China in July 1997. In the past, Hong Kong has been greatly influenced by the British system of nurses' training, which was very different from that in mainland China. As Hong Kong is now a part of China again, there is an increased opportunity for the exchange of experience and ideas among nurse educators. The First China-Hong Kong Nursing Education Conference has provided opportunities for the authors to gain a deeper understanding of the development of nursing education in China and Hong Kong. The authors believe that it is also important for China and Hong Kong to increase networking with the international nursing community. This paper has been written largely based on the information gathered from papers presented in the Conference and the discussion with nurse educators who attended the Conference, together with a review of literature. This paper focuses on comparing the history and present development of basic nursing education in both places. The future direction for the development of nursing education in these two places will also be discussed.

China↗
PubMed1999

The obstetric and neonatal performance of teenage mothers in an Australian community.

A cohort of 7191 single births in Liverpool Hospital, New South Wales was studied to examine whether an association between young age and adverse obstetric and neonatal outcomes can be supported, and what factors if any could be related to poor outcomes. Women were classified into four groups according to their confinement age, under the age of 18 years, between 18 and 19 years, between 20 and 34 years and 35 years or over. Teenage mothers in this community, especially under the age of 18 years, were very much disadvantaged in terms of socioeconomic status. The overall obstetric performance of teenage mothers was comparable with that of adult mothers. The neonatal outcomes were found to be poor in some aspects. However, the reasons for the adverse neonatal outcomes among teenagers are not due to the young age itself, but other contributing factors, such as maternal smoking, parity, and unmarried status.

Journal Article↗
PubMed1999

Argument for the surgical staging of apparent early endometrial cancer.

Cancer of the uterine corpus, commonly referred to as cancer of the endometrium or cancer of the uterus, continues to be the most common pelvic genital malignancy affecting western women (1). In 1998 in the United States 36,100 women were diagnosed with this cancer, and there were 6,300 deaths from this condition in that year. Of concern is that despite a relatively stable incidence over the last decade, the annual number of deaths since 1987 from endometrial cancer has more than doubled (2). Many controversies exist in the management of apparent early endometrial cancer. These include: 1. The role of surgical staging which includes pelvic lymphadenectomy. 2. The role of the subspecialist gynaecological oncologist in primary surgical treatment. 3. Indications for vaginal and external beam radiotherapy. 4. Who is at risk for recurrence? 5. The role of laparoscopic approach to the management of this disease. Despite their importance, these and other issues have not been appropriately addressed by prospective randomized studies. Treatment strategies and algorithms have thus been based upon a combination of clinicopathological studies and uncontrolled reviews. The views expressed in this clinical opinion are those of the Sydney Gynaecologic Oncology Group and reflect our philosophy on the current management of this tumour, supported by recent and appropriate peer reviewed scientific literature.

Brachytherapy↗
PubMed1999

Microlaparoscopic left upper quadrant entry in patients at high risk of periumbilical adhesions.

We performed a prospective study of microlaparoscopic direct entry in the left upper quadrant (LUQ) to determine the efficacy of this technique and the incidence and site of anterior abdominal wall adhesions in high-risk patients. Direct insertion of the MiniPort introducer was successful with 1 attempt in 16 patients and in 2 attempts with 1 patient. Overall, 12 patients (71%) had either bowel or omentum adherent to the anterior abdominal wall. Eight of the 12 patients (75%) with a previous midline abdominal wall incision were found to have subumbilical adhesions. Two patients were noted to have LUQ omental adhesions. Direct insertion of a 2 mm microlaparoscopic primary port in the LUQ appears to be simple, safe and quick to perform. It provides an excellent view of the peritoneal surface of the anterior abdominal wall and umbilical area. This procedure is likely to be the preferred method of peritoneal entry in high-risk patients in the future.

Abdominal Muscles↗