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K Mak

Publications and source records attributed to K Mak.

At least 19 recordsLinked to original sources
PubMed2006

Outcome of liver transplantation for children with liver disease.

INTRODUCTION: The advent of liver transplantation has revolutionised the outcome of children with both acute liver failure and chronic end-stage liver disease. The aim of this study was to review the outcome of all paediatric liver transplants performed since the National Liver Transplant Programme began in 1990. METHODS: A retrospective review of all paediatric liver transplants from 1990 to December 2004 was performed. RESULTS: 46 liver transplants were performed in 43 children, of whom 23 (53.3 percent) were female. Median age at transplant was 21 months (range 11 months to 14 years). The most common indication for liver transplant was biliary atresia (71.7 percent). Living-related transplants accounted for 63 percent (29). Re-transplant rate was 6.5 percent with allograft loss as a result of hepatic artery thrombosis (two) and hepatic vein thrombosis (one). Tacrolimus was the primary immunosuppressive agent used in 89 percent of patients, with a 19.6 percent incidence of acute allograft rejection within the first six months. There were nine deaths. They were related to portal vein thrombosis (three), chronic rejection (one), sepsis (two), post-transplant lymphoproliferative disease (two) and primary graft non-function (one). Overall actuarial one- and five-year survival rate was 85.7 percent and 81.8 percent, respectively. CONCLUSION: Liver transplantation is an established form of intervention for end-stage liver disease and a variety of liver-related metabolic disease. Our results are comparable to those of well-established liver transplant centres.

Adolescent↗
PubMed2006

Long-term post-liver transplant complications of renal impairment and diabetes mellitus: data from Singapore.

INTRODUCTION: Patients who survive the initial post-liver transplantation period face the development of chronic diseases in the long run. We studied two important complications of liver transplantation, namely: renal impairment and diabetes mellitus. METHODS: We analysed adult patients followed-up for more than one year using data from our liver transplant clinical records. Long-term post-transplant renal impairment (RI) was defined as glomerular filtration rate (GFR) less than 60 ml/min/1.73 square metres and long-term post-transplant diabetes mellitus (DM) was defined as fasting blood glucose more than 7.8 mmol/L, that existed at least one year after liver transplantation. Pre- and post-transplant factors that could be associated with these conditions were examined. RESULTS: Altogether, 35 patients were evaluated. Mean age at transplant was 50 years. Mean duration of follow-up was 58.4 months. There was 11.4 percent of pre-transplant RI and 17.0 percent of pre-transplant DM. Prevalence of post-transplant RI was 43.5 percent at one year and 45.0 percent at four years. Long-term post-transplant RI was associated with renal impairment at six months post-transplant (p-value is 0.033). Prevalence of severe post-transplant RI (GFR is less than 30 ml/min/1.73 square metres) at four years was 5.7 percent. Prevalence of post-transplant DM was 45.5 percent at two years but declined to 5.3 percent at four years. CONCLUSION: Post-transplant renal impairment appears to be a potential long-term problem while post-transplant diabetes mellitus appears to improve with time.

Diabetes Mellitus↗
PubMed2004

Successful listing of patients for liver transplant was related to participation of referring doctor in the transplant program.

INTRODUCTION: Experience with liver transplantation is limited in many parts of Asia. Therefore, patients from nontransplant centers may not be referred in a timely fashion for transplants. Our aim was to evaluate the pattern of referral for liver transplantation and their outcomes in Singapore. METHODS: Consecutive patients referred from 1990 to 2001 were reviewed. Patients from any hospital in Singapore (or the region) could be referred to the program. They were discussed at the weekly meetings. Appropriate patients were placed on the waiting list. "Pending" indicated that the disease was early or there were unsettled medical or social issues. Unsuitable patients were "rejected" for transplant. RESULTS: There were 385 patients referred over a 12-year period. Hepatitis B cirrhosis and hepatocellular carcinoma (HCC) were the most common indications among adults, whereas biliary atresia was the most common for children. Pediatric patients were more likely than adult patients to be listed for transplant (53/76 vs 106/309, P < .001). Patients referred by regular attendees of the program were more likely to be accepted than nonattendees (38% vs 25%, P = .04). "Disease too early", "advanced HCC", and "refusal by family members" were the most common reasons for rejection. CONCLUSION: Members of the Liver Transplant Program were more likely to refer suitable patients for transplant at the appropriate time. Better interaction between gastroenterologists inside and outside the transplant program would help to improve the timing of referrals for liver transplantation, and hence, patient survival.

Adult↗
PubMed2004

Adefovir dipivoxil as the rescue therapy for lamivudine-resistant hepatitis B post liver transplant.

INTRODUCTION: Complications of hepatitis B virus (HBV) infection are among the most common indications for liver transplant in many parts of Asia. However, none of the current posttransplant hepatitis B prophylaxis strategies, namely, lamivudine, hepatitis B immunoglobulin monotherapy, or combination therapy, is ideal. Our aim was to evaluate the use of adefovir dipivoxil (ADV) as a rescue therapy for posttransplant HBV patients who developed lamivudine resistance. METHODS: Twenty-two consecutive patients with HBV-related liver disease, who underwent first liver transplants from 1995 to 2002, received HBV prophylaxis with indefinite lamivudine with substitution of ADV for patients who developed drug resistance and clinical deterioration, defined as persistent elevation of transaminases or histologic deterioration. RESULTS: Sixteen patients (73%) were alive at their last follow-up and six (38%) had developed hepatitis B recurrence at a median of 46 (range 9 to 74) months posttransplant. Two with persistently normal transaminases and normal liver histology at 3 and 42 months postrecurrence have been continued on lamivudine. Four showed clinical deterioration and received ADV for a median of 24 months; all displayed normalization of transaminases and a 2 to 5 log drop in HBV DNA titers. Three had paired biopsies before and after substitution of ADV with two showing improvement and one stable appearance. The median serum creatinine value increased slightly from 126 to 138 micromol/L (P = 0.72). CONCLUSION: ADV is an effective rescue therapy for patients with lamivudine-resistant hepatitis B post-liver transplant. Further studies are needed to ascertain the optimal posttransplant hepatitis B prophylaxis.

Adenine↗
PubMed2004

Renal impairment and diabetes mellitus after liver transplant.

INTRODUCTION: One of the major concerns in liver transplant patients who survive past 1 year posttransplant is the development of chronic diseases. AIM: We studied two important clinical conditions that can have a chronic course-renal impairment and diabetes mellitus-among long-term liver transplant survivors. METHODS: All adult patients transplanted and followed for at least 1 year were evaluated for clinical status, blood tests, and imaging studies. The occurrence and development of renal impairment, defined as a serum creatinine above 125 micromol/L or creatinine clearance less than 75 mL/min, or diabetes mellitus were evaluated for contributing factors. RESULTS: The 35 evaluated patients of mean age at transplant of 50 years had a mean follow-up duration of 45 months. The incidence of posttransplant renal impairment was 22.8% at 1 year and 47.6% at 3 years. This disorder was associated with pretransplant renal impairment and with a diagnosis of diabetes. Posttransplant diabetes mellitus was observed in 48.6% with 41.1% resolving over time. CONCLUSION: Posttransplant renal impairment appears to be a potential long-term problem. Although this relates to pretransplant conditions, longer follow-up is required to examine whether posttransplant factors contribute to its progression.

Adolescent↗
PubMed2004

Persistent thrombocytopenia in liver transplant patients.

INTRODUCTION: The occurrence of thrombocytopenia in the perioperative period after a liver transplant is not uncommon. However, there are few studies on persistent thrombocytopenia during the longer follow up period of patients after liver transplantation. We examined the prevalence of and contributing factors to persistent thrombocytopenia beyond 1 year post-liver transplantation. METHODS: We analyzed adult patients followed for at least 1 year posttransplant with full blood counts and abdominal scans, as well as clinical notes. RESULTS: The 35 patients of mean age at transplant of 50 years and showed a mean follow-up of about 4 years showed a prevalence of persistent thrombocytopenia at 12 months of 54% and at 3 years of 25%. Factors that were associated with persistent thrombocytopenia were pretransplant variceal bleeding, splenomegaly, and thrombocytopenia at 3 and 6 months posttransplant. After multivariate analysis only the latter represented independent factors for persistent thrombocytopenia at 1 and 3 years posttransplant, respectively. CONCLUSION: Persistent thrombocytopenia improved over time posttransplant; no bleeding problem was observed among the affected cases.

Adolescent↗
PubMed1998

Real-time interactive simulator for percutaneous coronary revascularization procedures.

This article describes the simulation of real-time catheter navigation in our interactive interventional cardiology simulation system (ICard). ICard is designed to enable medical students or physicians to familiarize themselves with the techniques of interventional catheterization procedures. The ICard software provides three-dimensional (3-D) views of the blood vessels and fluoroscopic images for real-time visualization of the catheter position. The 3-D human vasculature is built from various image data sets and is represented with a central line hierarchy model. Navigation of the catheter and guide wire and their interaction with blood vessels are implemented by applying the finite element method. Physical modeling that features the elasticity of the catheter and guide wire was developed to provide a realistic simulation of catheterization procedures. An electromechanical device was also developed in the system, allowing physical manipulation of catheter and guide wire movements. ICard can be used for training and design of equipment for interventional cardiology and may be further extended for pretreatment planning.

Computer Simulation↗
PubMed1997

Early international results of laparoscopic gastrectomies.

BACKGROUND: The first totally laparoscopic Billroth II gastrectomy was performed in 1992. To date, laparoscopic gastrectomy has been performed by a small number of surgeons around the world and the laparoscopic approach has been extended to Billroth I and total gastrectomy. The aim of this study is to review the state of laparoscopically performed gastrectomies in the international scene. METHODS: Questionnaires were prepared and sent to every surgeon in the world known by the authors or their contacts to have performed a laparoscopic gastrectomy. A questionnaire survey was started in July 1994 and completed by November 1994. Data collected included age, sex, type of gastric resection, technique of reconstruction after resection, average duration of surgery, time to liquid and solid intake, postoperative hospital stay, complications, and opinions of the surgeons. RESULTS: Sixteen surgeons contributed to this study. A total number of 118 cases of laparoscopic gastrectomies, comprising Billroth I (11), Billroth II (87), vagotomy and antrectomy (10), and total gastrectomy (10) had been performed. The indications were gastric and/or duodenal ulcers and benign and malignant gastric tumors. CONCLUSIONS: Laparoscopic gastrectomy was found to be superior to the open technique by 10 of 16 surgeons because of faster recovery, less pain, and better cosmesis. The procedure was an expensive and long operation according to four. Two surgeons were uncertain of any benefit because of limited experience.

Adult↗
PubMed1996

Multicentric primary adenocarcinomas of the midgut: the first case report.

Multicentric adenocarcinomas of the midgut have not been described; even multiple adenocarcinomas limited to the small intestine are extremely uncommon, with only 14 cases reported in the literature. We report a case of multicentric synchronous involvement of the entire midgut with adenocarcinoma in a 52-yr-old Polish woman who had more than 30 lesions extending from duodenum to mid-transverse colon. There was no family history of cancer. Preoperative evaluation and intraoperative exploration were negative for primary malignancy of the lungs, breasts, ovaries, pancreas, and other parts of the gastrointestinal tract. Results of histopathological examination, immunohistochemical staining, and ras mutational analysis of the lesions uniformly support the diagnosis of multicentric poorly differentiated adenocarcinoma. The cause for this unusual presentation is unknown, although sporadic genetic alteration(s) of oncogene(s) might have been the precipitating event.

Adenocarcinoma↗
PubMed1996

Randomized trial of periportal peritoneal bupivacaine for pain relief after laparoscopic cholecystectomy.

The aim of this study was to determine whether injection of a long-acting local anaesthetic, in relation to the port sites at the level of the parietal peritoneum, would reduce postoperative pain following laparoscopic cholecystectomy. Patients were entered into a randomized, prospective, double-blind study comparing the effects of a standard technique, in which bupivacaine (total of 20 ml, 0.5 per cent) was injected into the subcutaneous periportal tissue around the four port sites, and a technique in which bupivacaine (total of 20 ml, 0.25 per cent) was injected into the subcutaneous periportal tissue as above with the addition of periportal parietal peritoneal injection of bupivacaine (total of 20 ml, 0.25 per cent). Two scores for pain, with the patient at rest, and on movement, were assessed 6 and 18 h after surgery using a visual analogue pain scale. Median pain score was significantly higher in patients who received standard technique (n = 40) than in those given peritoneal injection (n = 40) at both 6 (rest = 3.0 versus 1.0, movement = 5.0 versus 2.9) and 18 h (rest = 1.9 versus 0, movement = 3.2 versus 1.2). Both opiate and oral analgesic requirements were reduced in patients administered peritoneal injection, although this was not statistically significant. The addition of periportal injection of bupivacaine at the level of the parietal peritoneum, performed under direct vision, reduces pain after laparoscopic cholecystectomy.

Adult↗
PubMed1994

Polyclonals to beta-amyloid(1-42) identify most plaque and vascular deposits in Alzheimer cortex, but not striatum.

Alzheimer's beta-peptides (A beta) aggregation rates depend on A beta length. We made synthetic peptide antisera to A beta 34-40 and 37-42. Purified anti-34-40 preferentially recognizes beta 1-40, vascular amyloid and a subset of plaques while purified anti-37-42 recognizes A beta 1-42 and not A beta 1-40 in dot and Western blots and immunoprecipitates; 37-42 precipitates a small percentage of fibroblast secreted A beta and strongly stains all deposits identified by monoclonals to A beta on adjacent sections from frontal cortex, but not in dorsal striatum.

Alzheimer Disease↗
PubMed1994

Monoclonal antibody to the C-terminus of beta-amyloid.

Soluble amyloid beta-protein (A beta) is normally produced, but forms deposits in the brain of Alzheimer's (AD) patients. The length of isolated A beta in SDS-insoluble amyloid from AD brain is reported to vary between plaques and vessels ranging from 28 to 43, with major species being 40 and 42 residues. Because the A beta C-terminus determines aggregation rates, we made an A beta monoclonal antibody distinguishing beta 1-42 from beta 1-40. In AD cortex, the beta 1-42 antibody recognizes all the structures identified by monoclonal to beta 1-40 on adjacent sections: plaque cores, diffuse A beta deposits and vascular amyloid. These antibodies help define variation in A beta length between different deposits, regions and autopsied brains.

Alzheimer Disease↗
PubMed1994

Unilateral megalencephaly in association with Dandy-Walker complex.

Unilateral megalencephaly is a rare congenital anomaly. The authors report a case of unilateral megalencephaly associated with Dandy-Walker complex. The embryonic pathogenesis of both entities is discussed. In the absence of magnetic resonance imaging, computed tomography can be used to document these abnormalities.

Adult↗
PubMed1994

Primary left atrial leiomyosarcoma simulating pulmonary thromboembolism.

The authors describe a patient with primary left atrial leiomyosarcoma extending into the right pulmonary veins. The initial presentation and ventilation-perfusion scanning suggested pulmonary thromboembolism. The results of transthoracic echocardiography were nondiagnostic, and the diagnosis was eventually made on the basis of computed tomography (CT) and transesophageal echocardiography findings. The diagnosis was confirmed at surgery. This case demonstrates the complementary roles of CT and transesophageal echocardiography in the evaluation of intracardiac masses when transthoracic echocardiography is nondiagnostic. It also illustrates that cardiac tumours may present with nonspecific symptoms that mimic those of other disease.

Diagnosis, Differential↗
PubMed1994

Injectable filler materials for soft-tissue augmentation.

The concept of non-surgical implantation of injectable filler materials for soft-tissue augmentation has always been an attractive option for the head and neck surgeon. The ideal injectable soft tissue filler material would be easy to use, biocompatible, nontoxic, and long-lasting. Presently available filler materials present significant drawbacks to their use. The most favorable filler materials appear to be autologous fat and microparticulate alloplasts. This article reviews presently used injectable filler materials and those that may be used in the future.

Biocompatible Materials↗