Biomedical subjects

T Hui

Publications and source records attributed to T Hui.

10 recordsLinked to original sources

PubMed2002

Laparoscopic diaphragmatic hernia repair.

BACKGROUND: Adult-congenital diaphragmatic hernias and chronic traumatic diaphragmatic hernias are uncommon entities that are often technically challenging to repair. There is growing experience with a minimal access approach to these defects. METHODS: We reviewed the English-language literature using a MEDLINE search for "diaphragmatic hernia" and "laparoscopy." RESULTS: We found 19 case reports of laparoscopic adult-congenital diaphragmatic hernia repair. Reported complications included two enterotomies, one of which required conversion to laparotomy. We also found 11 case reports of laparoscopic chronic traumatic diaphragmatic hernia repair, with no reported complications or recurrences. Average operative time was 98 min, and average length of stay was 4.5 days. All reports claimed that there was less postoperative pain and an earlier return to full activity with the laparoscopic approach. Herein we discuss anatomy, pathophysiology, diagnosis, method of repair, and recurrence. CONCLUSION: Adult-congenital diaphragmatic hernia and chronic traumatic diaphragmatic hernia are amenable to laparoscopic repair. Although experience is still limited, laparoscopic repair appears safe and is associated with a shorter hospital stay.

Hernia, Diaphragmatic↗

PubMed2002

Acute pain services in Hong Kong: facilities, volume, and quality.

Acute pain services in public hospitals in Hong Kong were studied. Audit data on the volume and quality of acute pain services were collected prospectively from 1997 to 1999, and data on related facilities were collected in 2000. About 20% of patients undergoing a major operation received an acute pain service; of these, 78.6% were satisfied with the treatment provided. In 2000, 86% (18/21) of hospitals providing anaesthetic services were running an acute pain service. Staffing was better in hospitals providing a high volume of acute pain services, ranging from a full-time specialist anaesthesiologist assisted by a half-time trainee to a half-time specialist assisted by a full- or half-time trainee. However, only four hospitals were staffed with pain nurses. In total, 57% of patients received intravenous patient-controlled analgesia and 32% epidural analgesia. The mean duration of acute pain service treatment was 3.1 days. Currently anaesthesiologist-based acute pain services take care of a limited number of patients. To expand the coverage, there should be a move towards an anaesthesiologist-led, pain nurse-based, acute pain service. The present shortage of pain nurses should be addressed.

Analgesia, Patient-Controlled↗

PubMed2001

Enhanced proliferation and differentiation of rat hepatocytes cultured with bone marrow stromal cells.

Liver transplantation is the only clinically effective method of treating acute liver failure. However, wider application of this therapeutic modality is restricted primarily by shortage of donor organs. In the search for alternative methods of liver replacement therapy, investigators have focused on transplantation of normal allogeneic hepatocytes and on the development of liver support systems utilizing isolated hepatocytes. Since all human livers suitable for cell harvest are being used for transplantation, hepatocyte therapy using human tissue would require growing of cells in vitro. Unfortunately, although hepatocytes have tremendous capacity to proliferate in vivo, their ability to grow in culture is severely limited. Stromal cells from bone marrow and other blood-forming organs have been found to support hematopoiesis. In this paper, we show that bone marrow-derived stromal cells (BMSCs) enhance proliferation and support differentiation of rat hepatocytes in culture. Further, we demonstrate that in hepatocyte/BMSC co-cultures, clonal expansion of small hepatocytes (SH) is increased. Using semipermeable membrane cultures, we established that direct cell-cell contact is necessary for stimulation of cell proliferation. We also show that BMSCs which are in direct contact with hepatocytes and SH colonies express Jagged1. This suggests a potential role for Notch signaling in the observed effects. Finally, we present evidence that the expression and activity of liver specific transcription factors, CCAAT/enhancer binding proteins and liver specific key enzymes such as tryptophan 2,3-dioxygenase, are improved in hepatocyte/BMSC co-cultures. In conclusion, results of this study indicate that BMSCs could facilitate proliferation and differentiation of primary rat hepatocytes and their progenitors (SH) in vitro.

Animals↗

PubMed2001

Regulation of c-met expression in rats with acute hepatic failure.

BACKGROUND: Earlier we described a model of fulminant hepatic failure (FHF) in the rat where partial hepatectomy is combined with induction of right liver lobe necrosis. In FHF rats, lack of hepatocyte proliferation was associated with delayed expression of HGF and HGF receptor c-met. Since the c-met promoter region has Sp1 binding sites, we decided to examine whether in FHF rats down-regulation of c-met is associated with decreased Sp1 function and whether changes in blood HGF, IL-6, and TGFbeta1 levels might be responsible for these effects. MATERIALS AND METHODS: Induction of FHF, partial (2/3) hepatectomy (PH), and sham hepatectomy (SH) was performed in adult Sprague-Dawley rats. The levels of c-met mRNA and Sp1 DNA binding activity were studied in rat liver remnants at different time points after surgery. Blood levels of HGF, IL-6, and TGFbeta1 were also measured in these rats. Additionally, the effects of treatment with TGF-beta1, IL-6, or a combination of both on c-met expression and Sp1 DNA binding were studied in HGF-induced rat hepatocyte cultures. RESULTS: Compared to SH rats, in PH rat livers c-met was up-regulated after 6 h and Sp1 DNA binding was at or only slightly lower than levels at all time points studied. In FHF rat livers, c-met expression was markedly reduced after 2 and 6 h, moderate after 12 h, and undetectable after 24 h. At the same time, Sp1 DNA binding was detected at 2 h postinduction only. In FHF rats, blood levels of all three cytokines showed early and sustained elevation. In vitro, IL-6 had no effect on c-met expression, whereas TGFbeta1 up-regulated c-met. When used alone, none of the cytokines affected Sp1 DNA binding activity. In contrast, a combination of IL-6 and TGFbeta1 down-regulated c-met expression as well as Sp1 DNA binding activity. These effects were dependent on the IL-6 concentration used. This study suggests that following massive loss of hepatocyte mass in rats, early increase in blood IL-6 and TGFbeta1 levels may weaken the expression of HGF receptor c-met in surviving hepatocytes through suppression of Sp1 DNA binding.

Animals↗

PubMed2001

Bioartificial liver support.

Orthotopic liver transplantation is the only definitive therapy for patients with fulminant hepatic failure (FHF). However, due to shortage of organs, a large number of patients die before a liver can be procured for transplantation. In FHF the need for a liver is particularly urgent because of rapid deterioration in the patients' condition with the onset of cerebral edema and intracranial hypertension leading to irreversible brain damage. It is thus necessary to develop an extracorporeal liver support system to help maintain patients alive and neurologically intact until an organ becomes available for transplantation. Multiple attempts have been made, ranging from the use of plasma exchange to utilization of charcoal columns and extracorporeal devices loaded with liver tissue to develop liver support systems for treating patients with acute severe liver failure. None of these systems has achieved wide clinical use, and FHF due to multiple causes continues to be associated with significant morbidity and mortality. In this paper, the authors review the history of extracorporeal liver support for acute liver failure and discuss their experience with a hollow fiber bioartificial liver support system utilizing porcine hepatocytes in the treatment of patients with acute liver failure.

Acute Disease↗

PubMed2001

Anaesthetic clinical indicators in public hospitals providing anaesthetic care in Hong Kong: prospective study.

OBJECTIVES: To assess the quality of anaesthetic services as defined in the six anaesthetic clinical indicators against preset standards and to identify risk factors for adverse events in the recovery room. DESIGN: Prospective study. SETTING: All public hospitals providing anaesthetic care in Hong Kong. PATIENTS: Eighteen thousand, seven hundred and fifty-nine patients receiving elective or emergency anaesthesia administered by anaesthetists from June 1998 to July 1998. MAIN OUTCOME MEASURES: Patient demographics, American Society of Anesthesiologists status, category and nature of operation, presence of preoperative anaesthetic visit in ward, type of anaesthesia, reasons for a recovery room stay of more than a 2-hour duration, intubation to relieve respiratory distress in the recovery room, presence of hypothermia in the recovery room for operations lasting more than 2 hours, and dental or ocular injuries attributable to anaesthesia. RESULTS: There are two major findings from this study. Firstly, a high incidence of hypothermia in the recovery room was reported. Secondly, a greater risk of prolonged stay in the recovery room was identified for patients older than 65 years, major operations, and anaesthetic techniques using combined general and regional anaesthesia. CONCLUSION: The six anaesthetic clinical indicators reflected the provision of anaesthetic care in public hospitals in Hong Kong. Good compliance to the preset standard of the anaesthetic clinical indicators was achieved during the study period.

Adolescent↗

PubMed1995

A tumor-derived protein which provides T-cell costimulation through accessory cell activation.

A recently described tumor-derived glycoprotein, designated 90K, has been shown to have positive effects on the generation of cytotoxic effector cells (NK/LAK) from human PBMC. To determine the mechanism of these effects, we have examined the effects of 90K on cytokine production by human PBMC. A culture of normal PBMC with 90K alone did not result in IL-2 secretion; however, in coculture with suboptimal doses of ConA, 90K increased IL-2 secretion by PBMC. Coculture of PBMC with 90K and ConA also resulted in increased production of the cytokines IL-1, IL-6, GM-CSF, and TNF alpha. T cells depleted of accessory cells failed to respond to ConA alone, 90K alone, or the combination of ConA and 90K, suggesting that this protein does not have a direct effect on T cells. However, 90K alone was sufficient to induce cytokine production by unfractionated PBMC (IL-1, IL-6, GM-CSF, and TNF alpha) or by CD14-enriched PBMC (IL-1 and IL-6). In addition, expression of ICAM-1 was increased on a human monocytic cell line cultured with purified 90K in the absence of any other stimulus. This 90K-induced upregulation of ICAM-1 expression was accompanied by an increased accessory function of the monocytes, demonstrated by their ability to support ConA-induced activation of peripheral blood T cells. Based on the current data, we propose a model in which 90K activates accessory cells, resulting in the secretion of cytokines and the expression of adhesion molecules, which in turn act as costimulatory signals for T-cell activation. Activated T cells then produce cytokines such as IL-2, which lead to a more vigorous cell-mediated immune response to tumor cells and virus-infected cells. Thus, 90K shows promise as an immunotherapeutic reagent for diseases such as cancer and viral infection.

Antigen-Presenting Cells↗

PubMed1994

Benign intracranial hypertension: a cause of CSF rhinorrhoea.

Four patients undergoing treatment for benign intracranial hypertension presented with spontaneous CSF rhinorrhoea. The four patients, all women, were aged between 33 and 44 years. They had been receiving treatment for benign intracranial hypertension for a period ranging from eight months to 11 years, before developing the CSF leak. There was no history of previous head injury and there were no congenital anomalies of the floor of the anterior fossa. The site of the CSF fistula was localised to the cribriform plate in all four cases. The pathophysiology of the CSF rhinorrhoea and the surgical management of this group of patients are discussed. The authors propose that benign intracranial hypertension should be included in the classification of high pressure CSF leaks.

Adult↗

PubMed1990

Identifying hypertensive patients with elevated systolic workplace blood pressures.

The present study was designed to identify patients who had systolic work blood pressures that were substantially higher than their clinic blood pressures. Fifty-two mild and moderate hypertensive patients were assessed using clinic blood pressures and ambulatory blood pressure monitoring in their natural environment. Thirty-eight percent of these patients had systolic work blood pressures that were more than 10 mm Hg above their clinic blood pressures. These patients did not differ from other patients in terms of the demographic or clinical factors which were assessed. Need for control and anger, two core features of the Type A Coronary-prone Behavior Pattern, were shown to discriminate these patients on a statistically reliable basis. Research on cardiovascular reactivity to stress suggests that such patients with elevated systolic work blood pressures may be at greater risk for cardiac morbidity and mortality.

Analysis of Variance↗

PubMedDate not supplied

The white-coat hypertension response: prevalence and predictors.

This study was designed to determine the clinical characteristics of hypertensive patients whose blood pressures are substantially higher in the medical office than in their natural environments. Thirty-nine percent of patients enrolled in a nonpharmacologic hypertension treatment program had systolic or diastolic office blood pressures (OBPs) that were at least 10 mm Hg higher than their ambulatory blood pressures (ABPs). Although these white-coat responders (WCRs) had higher systolic OBPs than did non-white-coat responders (NRs), both their systolic (p less than 0.02) and their diastolic (p less than 0.0001) ABPs were significantly lower than those of NRs. Furthermore, patients with white-coat hypertension did not have greater blood pressure reactivity in their natural environments, suggesting that their blood pressure elevations may be specific to the medical setting. White-coat hypertensives were older (p less than 0.005), had less angry dispositions (p less than 0.01), and reported less overt anger expression (p less than 0.005). They were also taking more antihypertensive medications than were the other patients in the study (p less than 0.001).

Antihypertensive Agents↗