Search PubMed⌕ Search

Biomedical subjects

M K Li

Publications and source records attributed to M K Li.

At least 55 records · Page 3Linked to original sources
PubMed1996

Somatostatin reduces gastric mucosal blood flow in patients with portal hypertensive gastropathy: a randomized, double-blind crossover study.

Agents which decrease gastric mucosal blood flow (GMBF) are postulated to have beneficial effects in arresting gastrointestinal bleeding in cirrhotic patients with portal hypertension. Our objective was to test the hypothesis that in a dose that significantly lowers wedged hepatic venous pressure (WHVP), a bolus injection of somatostatin will significantly decrease GMBF in patients with portal hypertensive gastropathy (PHG). In this placebo-controlled, double-blind, crossover study, 20 cirrhotic patients with PHG were randomly assigned to receive either somatostatin followed by placebo (Group A) or placebo followed by somatostatin (Group B). Wedged hepatic venous pressure was monitored. GMBF in the antrum and corpus was assessed by reflectance spectrophotometry. Indices of hemoglobin concentration (IHb) and indices of oxygen content (ISO2) were recorded. Nine patients were assigned to Group A, and 11 to Group B. Mild PHG was seen in 16 patients, and severe PHG in 4 patients. Baseline WHVP, IHb, and ISO2 were similar in both treatment groups. Wedged hepatic venous pressure (WHVP) was significantly lowered [median, 17.6%; interquartile range (-27.0,-12.6%); P = 0.0008] after a 250-microg bolus injection of somatostatin. This dose of somatostatin significantly reduced IHb both in the antrum [-10.2% (-23.4, 0.4%)] and in the corpus [-5.8% (-16.6, 5.6%)] compared to placebo (P = 0.02 and 0.04, respectively). Intravenous bolus injection of 250 microg somatostatin significantly reduces WHVP and GMBF in patients with PHG. Whether this ability to decrease the GMBF in PHG makes somatostatin an effective treatment in acute gastrointestinal bleeding in PHG deserves to be studied.

Aged↗
PubMed1996

Gasless laparoscopic excision of bleeding gastric polyp.

A case of bleeding gastric polyp in an elderly woman with compromised respiratory function was treated successfully as an emergency by the gasless laparoscopic technique after endoscopic means failed to control the bleeding. The application of laparoscopic mechanical stapling devices allows rapid gastrotomy and resection, with simultaneous hemostasis that is beneficial in acute bleeding condition. The use of gasless laparoscopy also allows continuous suction to be applied for identification of the bleeding pathology and it also reduces the risk of pneumoperitoneum in patients with poor cardiorespiratory reserve. The operative approach and technique are fully discussed.

Aged↗
PubMed1996

An unusual presentation of renal cell carcinoma with deep vein thrombosis of the calf.

Renal cell carcinoma is a malignant tumour that involves the vena cava in 4% to 10% of patients undergoing radical nephrectomy. Of these only a third to half presented with symptoms of vena caval involvement. We present a case of renal cell carcinoma with vena caval involvement that presented with just a swollen right leg. The patient was staged and had a nephrectomy and resection of the inferior vena cava. Due to extensive collateral venous drainage renal function was not compromised and he was discharged well.

Carcinoma, Renal Cell↗
PubMed1996

Percutaneous nephrolithotomy--results and clinical experience.

Percutaneous nephrolithotomy (PCNL) and extracorporeal shockwave lithotripsy (ESWL) have largely replaced open surgical intervention for the management of upper urinary tract calculi. ESWL is the preferred treatment modality for calculi less than or equal to 2 cm in diameter as morbidity is lower than PCNL and success rates are comparable. However, the morbidity of ESWL rises substantially for stones greater than 2 cm in diameter while stone-free rate is less when compared to PCNL, suggesting that PCNL is the preferred treatment modality for most larger stones. PCNL was performed on 86 patients with 87 renal calculi. The indication for this approach was either high stone burden as in 72 patients (83%) or failed previous ESWL as in 15 patients (17%). The success rate was 74.7% and this was associated with minimal morbidity which included; symptomatic urinary tract infection (9.2%), pleural effusion (2.3%) and the formation of a pseudo-aneurysm (2.3%). Blood transfusion was required in one patient (1.1%) and we had one postoperative death due to massive pulmonary embolism (1.1%). PCNL is the preferred approach to patient with difficult renal calculi at our institution.

Adult↗
PubMed1996

Use of iontophoretic anaesthesia in urologic surgery: a preliminary experience.

Iontophoretic anaesthesia involves the active transport of lignocaine into underlying tissues, by means of an electric field, for anaesthesia. Its use in urology in transurethral operations on the bladder and prostate have been well documented. We present a preliminary experience of its use in the following cases: a transurethral resection of a bladder tumour, a transurethral resection of bladder cysts and incision of the bladder neck and a transurethral resection of the prostate. In the few cases that we did, we found that patient selection and patient preparation is of utmost importance as unlike a complete anaesthesia, the patients can feel deep pressure and heat if diathermy is prolonged. It is also important not to oversedate the patients with midazolam as an uncooperative patient may render any procedure impossible. The greatest drawback of this procedure is that the degree of anaesthesia tends to vary from person to person. As such, it is difficult to predict who would or would not respond to this from of anaesthesia. However, with improvements in protocols, current delivery systems and different anaesthetic agents used, one may see a proliferation of this form of anaesthesia in urology in the not too distant future.

Adult↗
PubMed1995

Antibacterial treatment of gastric ulcers associated with Helicobacter pylori.

BACKGROUND: There is a strong association between infection with Helicobacter pylori and gastric ulcers that are unrelated to the use of nonsteroidal antiinflammatory medications. We studied the efficacy of antibacterial therapy without medication to suppress gastric acid for the treatment of patients with H. pylori infection and gastric ulcers unrelated to the use of nonsteroidal agents. METHODS: Patients with gastric ulcers seen on endoscopy and with H. pylori infection confirmed by smear or culture were randomly assigned to receive either a one-week course of antibacterial agents (120 mg of bismuth subcitrate, 500 mg of tetracycline, and 400 mg of metronidazole, each given orally four times a day) or a four-week course of omeprazole (20 mg orally per day). Follow-up endoscopies were performed after five and nine weeks. The patients and their physicians were aware of the treatment assignments, but the endoscopists were not. RESULTS: A total of 100 patients were randomly assigned to treatment, and 85 completed the trial. At five weeks, H. pylori had been eradicated in 41 of the 45 patients in the antibacterial-treatment group (91.1 percent; 95 percent confidence interval, 82.9 to 99.3) and in 5 of the 40 in the omeprazole group (12.5 percent; 95 percent confidence interval, 2.3 to 22.7; P < 0.001). The gastric ulcers were healed in 38 of the patients treated with antibacterial drugs (84.4 percent; 95 percent confidence interval, 73.9 to 95.0) and in 29 of those treated with omeprazole (72.5 percent; 95 percent confidence interval, 58.6 to 86.4; P = 0.28). At nine weeks, ulcer healing was confirmed in 43 of the patients receiving antibacterial therapy and in 37 of those receiving omeprazole (P = 1.0). The mean (+/- SD) duration of pain during the first week of treatment was 1.9 +/- 2.6 days in the omeprazole group, as compared with 3.6 +/- 3.0 days in the antibacterial-treatment group (P = 0.004). One year after treatment, recurrent gastric ulcers were detected in 1 of 22 patients (4.5 percent) in the antibacterial-treatment group and in 12 of 23 (52.2 percent) in the omeprazole group (P = 0.001). H. pylori was detected in the 1 patient with a recurrent ulcer who had received antibacterial treatment and in 10 of the 12 patients with recurrent ulcers who had received omeprazole. CONCLUSIONS: In patients with H. pylori infection and gastric ulcers unrelated to the use of nonsteroidal antiinflammatory drugs, one week of antibacterial therapy without acid suppression heals the ulcers as well as omeprazole and reduces the rate of their recurrence.

Adult↗
PubMed1995

Determination of heparan sulphate in kidney tissues of patients with calcium nephrolithiasis.

While the pathogenic mechanisms responsible for calcium nephrolithiasis remain unknown, the influence of heparan sulphate proteoglycan (HSPG) on disease progression of other diseases, such as polycystic kidneys and diabetic glomerulosclerosis, makes it an important candidate for the study of stone formation. Using the indirect immunofluorescence assay and image analysis, we were able to quantify and visualize the loss of HSPG localized in the basement membrane of the glomerulus and the mucosa of ureter or renal pelvis in patients with recurrent calcium nephrolithiasis as compared to normal subjects. However, no significant change in HSPG was observed in the basement membrane of the tubular epithelium. The decreased HSPG in the glomerulus may reflect the potentially disrupted anion/neutral barrier for glomerular filtration, which would encourage the accumulation of stone solutes. The drop in HSPG staining intensity in the basement membrane of the mucosa of ureter/renal pelvis may suggest the tendency of adhesion of crystal to urothelial surfaces. Based on these immunological data, it appears that HSPG plays a modulatory role in the pathogenesis of this disease.

Adult↗
PubMed1995

Somatostatin attenuates the hyperdynamic circulatory state in the gastric mucosa of rats with portal hypertension.

BACKGROUND: Portal hypertensive gastropathy is characterized by a hyperdynamic circulatory state in the gastric mucosa. We assessed the effect of bolus injection of somatostatin on gastric mucosal perfusion in a rat model of portal hypertension. We tested the hypothesis that somatostatin will reduce gastric mucosal perfusion in portal hypertension. METHODS: Portal hypertension was induced by two-stage portal vein ligation (PVL). Two weeks after PVL significant elevation of portal venous pressure was demonstrated. Gastric mucosal hemodynamic changes were measured by reflectance spectrophotometry, which records the indexes of mucosal hemoglobin oxygen saturation (ISO2) and mucosal hemoglobin concentration (IHB). RESULTS: After an intravenous bolus of 1 microgram somatostatin significant reductions of ISO2 and IHB were demonstrated in the rats with PVL (ISO2, -34 +/- 5%; IHB, -15 +/- 2%) and the controls (ISO2, -26 +/- 4%; IHB, -15 +/- 2%). A dose-response relationship was shown by using 0.01, 0.1, and 1 microgram of somatostatin. Somatostatin did not induce other hemodynamic changes except a transient drop in systemic blood pressure of 8-10%. CONCLUSION: The significant reductions of gastric mucosal ISO2 and IHB by somatostatin support the hypothesis that somatostatin is capable of attenuating the hyperdynamic circulatory state in the gastric mucosa of rats with portal hypertension and may have a beneficial effect on portal hypertensive gastropathy. This hypothesis deserves to be evaluated in clinical studies.

Analysis of Variance↗
PubMed1995

Transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia (BPH)--our first 100 cases.

One hundred consecutive cases treated by Transurethral Microwave Thermotherapy (TUMT) since October 1991 were analysed to assess its efficacy and safety. Out of these, 28 were in urinary retention. Patients were selected based on Madsen Symptom Score (MSS), Uroflowmetry, Transrectal Ultrasound Scanning (TRUS) plus biopsy and flexible cystoscopy. In the non-retention group, symptomatic improvement was 81%; mean MSS dropped from 13.6 to 2.6 at one year. Objective improvement was less marked: mean peak urine flowrate (PFR) (+45%), mean residual volume (-63%) and mean prostatic volume (-15%). 8.3% had failed TUMT requiring TURP. In the retention group, 79% was able to void freely after TUMT. Fourteen percent underwent TURP. Based on given criteria, the overall response rate for MSS and PFR averaged 71% at 3 months, 72% at 6 months and 84% at 1 year. Sixty-seven percent of patients who responded to a phone interview were satisfied with TUMT treatment. Minimal morbidity was encountered: temporary retention for non-retention group (24%), UTI (9%), haematuria (7%), impotence (2%) and fistula (1%). There was no treatment-related death. The results showed that TUMT is a viable alternative and safe treatment of BPH.

Adult↗
PubMed1995

Ureteric colic: value of initial investigations and the outcome.

During a one-year period (from April 1992 to April 1993), 294 patients with the complaint of ureteric colic seen at the Emergency Department of Tan Tock Seng Hospital were investigated with a plain X-ray of the kidney, ureter and bladder (KUB), urinary analysis (urine FEME) and subsequently intravenous urogram (IVU) at the outpatient clinic. The results showed that majority (73%) of the patients were male. Sixty percent of the cohort were in the age group 30-50 years. After evaluation, it was found that only 114 (39%) of the patients with ureteric colic had abnormal IVU. Among these patients, 99 were diagnosed to have calculus disease, 12 with urothelial tumours, 1 with renal cyst and 2 had no pathology detected. Nevertheless most (72%) of the patients did not require intervention. In addition, it was noted that if the KUB or urine FEME was positive, the chances that a urological pathology was present were 72% and 91% respectively. However, if both of them were negative, the chance that a pathology would not be present was 93%. This suggests that patient selection is very essential to avoid unnecessary investigations.

Adolescent↗
PubMed1995

Clinical evaluation of impotence.

With better understanding of the pathophysiology of erectile dysfunction, various causes of impotence can be identified accurately with the help of different investigation modalities. However, it is controversial as to what extent investigations are considered as adequate because most of the time they do not influence patient management. The clinical evaluation of erectile dysfunction should include a thorough sexual and medical history and physical examination. Further special investigations such as nocturnal penile tumescence studies, duplex ultrasonography, dynamic infusion cavernosometry and cavernosography, and arteriography should only be ordered logically after careful consideration of whether they will affect patient outcome. Therefore in this review, we aim to evaluate critically these different special investigations with regards to their indications and pitfalls so that a logical approach to the evaluation of impotence can be obtained.

Erectile Dysfunction↗
PubMed1995

Use of prostate specific antigen (PSA) and transrectal ultrasound (TRUS) in the diagnosis of prostate cancer--a local experience.

Prostate specific antigen (PSA) and transrectal ultrasound (TRUS) are two new modalities added to improve our ability to diagnose prostate cancer at an early stage. We reviewed our own experience of 100 cancers among 579 men from August 1991 to October1994. The detection rate was 17.3%. Digital rectal examination (DRE) alone had a positive predictive value (PPV) of 39.9%. The PPV for PSA was 23%. The combination of PSA and DRE gave a PPV of 47.2%. TRUS had a PPV of 30.6%. Features of cancer on TRUS may be both hypoechoic or hyperechoic nodules which appeared to have almost equal proportions associated with cancer. The addition of age-specific ranges did not affect the PPV of PSA. The PPV of the combination of TRUS and DRE was 53%. With all 3 modalities combined, the PPV was 58.8%. An interesting finding from the study was the higher average PSA for benign and malignant disease in the local population and cases of acute retention of urine. There was a higher incidence of prostatitis and lower incidence of cancer in cases with retention of urine.

Adult↗
PubMed1995

Transrectal ultrasound in male infertility.

In the evaluation of the subfertile man who has severe oligospermia or azoospermia associated with a low volume ejaculate, the high resolution transrectal ultrasound (TRUS) has, in recent years, been a very important non-invasive imaging technique to detect abnormalities in the seminal vesicles, ejaculatory duct and the status of the prostate. We performed TRUS in 30 of these patients from January to December 1994 followed by scrotal exploration with vasogram using methylene blue, inspection of the epdidymis for dilatation and fibrosis together with testicular biopsy to evaluate testicular spermatogenesis and obstruction. Of the 30 patients, 11 were found to have dilated vesicles or ejaculatory duct obstruction. Three had features of prostatitis with calcification or thickened wall of the vesicles and one had an absent vesicle and vas. The remaining 15 patients had normal seminal vesicles and ejaculatory ducts on TRUS and their testicular biopsies showed atrophy, fibrosis or maturation arrest. Transurethral resection of the ejaculatory duct (TRU-ED) under TRUS guidance was done for 10 patients with dilated seminal vesicles and 6 of them had normal semen analysis 3 months after operation. Two successful pregnancies were achieved.

Adult↗
PubMed1994

Crystallization of urinary calcium oxalate at standardized osmolality and pH in the frozen state.

The potential of whole urine of stone-formers and normal controls to precipitate crystals of calcium oxalate dihydrate from ions endogenous in urine was investigated by the method of rapid evaporation to 1250 mOsm/kg and subsequent freezing. Over 90% incidence in crystallization was achieved in the two groups. When the population density and size of these crystals were compared, it was found that 50% of urine samples from stone formers (30-50 years of age) were rich in crystal-nucleating and growth-inhibiting factors and the other 50% were not different from normal controls. These effects were observed when polyanionic macromolecules recovered from pooled urine samples of stone-formers or normal controls were dissolved in urine ultrafiltrate and similarly tested. That the urinary polyanions were the active modifiers in the test system was further corroborated by the reversal of crystallization activity of urine samples and the urinary polyanions after they had been through an acidification-reneutralization procedure. The urinary polyanionic macromolecules were found, after enzymatic and/or chemical treatment, to contain chondroitin sulphates, dermatan sulphates, heparan sulphates and glycoproteins.

Acids↗
PubMed1994

Laparoscopic management of complications following laparoscopic cholecystectomy.

Laparoscopic cholecystectomy has rapidly become the treatment of choice for symptomatic cholelithiasis. Although published morbidity and mortality rates compare favourably with open cholecystectomy, bile duct injuries occur far more frequently and technical complications unique to the laparoscopic approach account for a significant number of postoperative deaths. The majority of these complications are dealt with by laparotomy. Two technical complications encountered in a series of 170 patients undergoing laparoscopic cholecystectomy and their subsequent management are presented. One patient suffered a diathermy injury to the common hepatic duct and postoperative bile leak. This was managed successfully by repeat laparoscopy and peritoneal lavage combined with endoscopic retrograde cholangiopancreatography (ERCP) and stenting of the hepatic duct. Another patient sustained a perforated duodenum complicated by peritonitis, subcutaneous wound infection and generalized sepsis. The perforation was repaired at a second laparoscopy using intracorporeal suturing and Tissucol. It is demonstrated that it is possible to deal with some of the technical complications of laparoscopic cholecystectomy with a combination of minimally invasive techniques, sparing the patient from the additional risk of laparotomy.

Adult↗