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C M Chin

Publications and source records attributed to C M Chin.

11 recordsLinked to original sources
PubMed2005

Methicillin-resistant Staphylococcus aureus endocarditis after transurethral prostatic resection.

We report the first case, to our knowledge, of methicillin-resistant Staphylococcus aureus endocarditis complicating transurethral prostatic resection for benign prostatic hyperplasia. The patient had been catheterized preoperatively because of urinary retention and, postoperatively, developed pyrexia with persistent methicillin-resistant S. aureus-positive blood cultures. The cause remained elusive, despite extensive investigations (including echocardiography), until he developed embolic phenomena pathognomonic of infective endocarditis 1 month into treatment with intravenous vancomycin.

Aged↗
PubMed2002

Penile colour duplex ultrasonography as a screening tool for venogenic erectile dysfunction.

INTRODUCTION: Vasculogenic impotence is one of the major causes of erectile dysfunction. Cavernosometry and cavernosography is traditionally the gold standard for evaluation of venogenic impotence. However, it is invasive and there are potentially significant complications. Penile colour flow Doppler imaging (PCDI) is non-invasive and can be used to assess venous incompetence. MATERIALS AND METHODS: One hundred and sixty-eight patients were referred for PCDI assessment from March 1998 to February 2001. Forty-three of these also had cavernosogram and cavernosometry done and were included in the study. RESULTS: The sensitivity was 93.9%, the specificity was 90.0%, the accuracy was 93.0% with a negative predictive value of 81.8% and a positive predictive value of 96.9%. Kappa value of 0.81 was obtained, indicating excellent agreement between PCDI and cavernosogram and cavernometry. CONCLUSIONS: Penile colour flow Doppler imaging is accurate in the assessment of venogenic erectile dysfunction. It can replace cavernometry and cavernosogram as a screening tool. Cavernometry and cavernosogram should only be done in cases when PCDI suggests venogenic impotence, and when surgery is contemplated.

Adult↗
PubMed2002

The role of BTA stat in clinical practice.

OBJECTIVE: BTA stat is a rapid, urine-based test for bladder cancer that detects human complement factor H related protein (HCFHrp) by monoclonal assay. This aim of this study was to assess the efficacy of BTA stat as a diagnostic tool for bladder cancer in symptomatic patients suspected of bladder cancer and in the surveillance of patients with a history of treated bladder cancer. PATIENTS AND METHODS: One hundred and six patients presenting with haematuria (gross or microscopic) or irritative bladder symptoms presenting to the urology outpatient clinic of Changi General Hospital and 13 patients under bladder cancer surveillance were recruited for this prospective study. All underwent voided urine cytology (VUC), urine culture, urine BTA stat, intravenous urogram and cystoscopy. Sensitivity, specificity, positive and negative predictive values were calculated for both tests. The stage and grade of bladder tumours detected were also correlated with both test results. Causes of false positives and specificity in different patient groups were analysed. RESULTS: BTA stat is more sensitive than VUC in detecting primary and recurrent bladder tumours (85% versus 55%) but is less specific (62.6% versus 100%). Urinary tract infections and urinary calculi accounted for 62% of false positives with BTA stat. When patients with positive urine cultures and benign IVU abnormalities were excluded, specificity of BTA stat improved (93.9% cf. 62.6%). BTA stat was highly specific (100%) and more sensitive than VUC (75% versus 25%) in detecting recurrent tumours in asymptomatic patients on cancer surveillance. CONCLUSION: A high false positive rate and low predictive value limits the use BTA stat in screening symptomatic patients. However, it has a role in cancer surveillance and in the screening of high-risk asymptomatic individuals. Further prospective trials should be performed to better assess its role in this respect.

Adolescent↗
PubMed2001

Dissociation and electrooxidation of primaquine diphosphate as an approach to the study of anti-chagas prodrugs mechanism of action.

This paper describes the voltammetric behavior of primaquine as a previous support to the further understanding of the delivery and action mechanisms of its respective synthesized prodrugs. There are few papers describing the drug behavior and most of the time no correlation between oxidation process and pH is done. Our results showed that primaquine oxidation is a one-step reaction involving two electrons with the charge transfer process being strongly pH-dependent in acid medium and pH-independent in a weak basic medium, with the neutral form being easily oxidized. This leads to the conclusion that quinoline nitrogen ring neutralization is a determinant step to the formation of the oxidized primaquine form. The existence of a relationship between the primaquine dissociation equilibrium and its electrooxidation process is shown. This work points the importance of voltammetric methodology as a tool for further studies on quantitative relationship studies between chemical structure and biological activity (QSAR) for electroactive drugs.

Antiprotozoal Agents↗
PubMed2001

Holmium laser lithotripsy in the management of ureteric calculi.

INTRODUCTION: To evaluate the efficacy and safety of the holmium:YAG laser in retrograde ureteroscopic laser lithotripsy of ureteric calculi. METHODS: Three hundred and twenty-five patients (256 males and 69 females) with mean age of 45 years underwent 328 retrograde ureteroscopic laser lithotripsy as the primary therapy for ureteric calculi using semirigid mini-ureteroscopes and the holmium:YAG laser (Coherent, Palo Alto, California, USA). Four consultants and three registrars performed the procedures over a period of 31 months. RESULTS: The mean largest diameter of the calculi was 8.4 mm. The mean hospital stay was 1.8 days and the mean duration for the operation was 25 minutes. One hundred and twenty-two (37%) procedures were done as day surgery cases. Complete stone-free rates after single primary treatment using only the holmium:YAG laser were 75% and 91% at 4 weeks and 12 weeks of follow-up, respectively. Including 22 (7.6%) renal units which required additional procedures, the overall stone-free rate was 97%. Seventeen cases (5.2%) needed additional extracorporeal shock wave lithotripsy (ESWL) and 5 cases (1.5%) needed an additional repeat ureteroscopy and lithotripsy for complete stone clearance. Significant complications include 1 case of ureteric perforation. CONCLUSIONS: The holmium:YAG is a safe and effective intracorporeal lithotripter when deployed in a retrograde manner in conjunction with a mini-ureteroscope.

Female↗
PubMed2000

Retroperitoneal Castleman's disease in the perinephric space--imaging appearance: a case report and a review of the literature.

INTRODUCTION: Castleman's disease (CD) is a rare lymphoid tumour usually found in the mediastinum. Extrathoracic sites are uncommon. Its radiological findings may be similar to other retroperitoneal tumours, making diagnosis difficult. CLINICAL PICTURE: A 54-year-old female was found to have an incidental hypoechoic mass in the left posterior perinephric space on routine ultrasound. Abdominal computed tomography (CT) scan demonstrated an isodense mass which enhanced brightly with intravenous contrast. Angiogram confirmed a hypervascular mass. TREATMENT: The retroperitoneal mass was excised. OUTCOME: Histology revealed CD of hyaline-vascular type. CONCLUSION: CD should be considered in the differential diagnosis of a retroperitoneal mass, which demonstrates homogeneous and intense enhancement.

Biopsy, Needle↗
PubMed1997

Use of patient-controlled analgesia in extracorporeal shockwave lithotripsy.

OBJECTIVE: To assess the advantages of patient-controlled analgesia (PCA)-in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for urinary stones. PATIENTS AND METHODS: Between December 1995 and May 1996, a prospective study was carried out on 100 patients who underwent ESWL for urinary stones. The patients were assigned to two equal groups, one receiving PCA and the other pethidine (control). Patients in the PCA group self-administered varying doses of intravenous alfentanil according to their pain tolerance, while those in the control group were given a single bolus dose of 1 mg/kg body weight intravenous pethidine by the attending urologist before the start of the procedure. The stone site, maximum energy level achieved, number of shock waves given, duration of procedure, pain scores, patient tolerance and acceptance were recorded to assess the efficacy of PCA compared with analgesia controlled by the physician. RESULTS: Both groups were matched for age, body weight, stone location and number of shocks given. The PCA group received a mean of 1.03 mg alfentanil while the control group received a mean of 62.5 mg pethidine. The maximum discharge voltage of 16 kV was achieved in all but one patient (98%) in the PCA group whereas only 21 patients (42%) in the control group attained this level. The mean treatment duration was less in the PCA group (32.8 min) than in the control group (44.5 min), the mean pain score lower (3.76 and 4.62, respectively) and the incidence of nausea and vomiting much less (22% and 60%, respectively). In addition, all 21 patients in the PCA group who had received intravenous pethidine during previous sessions of ESWL chose PCA as the better form of analgesia. There were no adverse effects in the PCA group except for one patient whose arterial oxygen saturation decreased transiently. CONCLUSION: PCA enables the urologist to achieve better patient compliance through better pain control; its application has maximized the use of lithotripsy and the patients' acceptability for this form of analgesia is confirmed. We recommend that this form of analgesia be used for ESWL.

Adolescent↗
PubMed1996

Prostate screening--the Singapore experience.

BACKGROUND: The prevalence of benign prostatic hyperplasia (BPH) is believed to be highly significant in most communities. In our country, many elderly men are unaware that something can be done for their troublesome urinary symptoms. The main objective of our prostate health screening was to educate our elderly male population that this is an abnormality, for which treatment is readily available. At the same time, we attempted to determine the prevalence of BPH, to detect possible prostate cancer, and to derive normal prostate specific antigen (PSA) and uroflow values for our population. METHODS: Over an eight-day period in April 1994, 799 men above the age of 50 years volunteered to participate in a free prostate screening exercise held at our hospital. The parameters assessed were PSA level, American Urological Association (AUA) symptom score, uroflowmetry, and digital rectal examination (DRE) of the prostate. RESULTS: Elevated PSA levels of more than 4 micrograms/L were detected in 105 men (13.1%). Of these, 23 men (2.9%) had PSA values above 10 micrograms/L. Abnormal AUA symptom scores of more than eight (moderate and severe categories) were noted in 540 men (67.6%). Clinically enlarged prostate glands of more than 20 g on DRE were noted in 80 men (10.0%), and abnormal DRE findings were detected in 48 men (6.01%). Impaired maximal uroflow rates of less than 10 mL/s were recorded in 224 men (39%), while another 167 men (29.1%) had maximal uroflow values in the equivocal zone (between 10 to 15 mL/s). The reference PSA levels at the 5th percentile, 10th percentile, median, mean, 90th percentile and 95th percentile were 0.38, 0.47, 1.05, 1.57, 3.27 and 4.25 micrograms/L, respectively. The age-specific PSA values were 3.51, 3.78 and 6.02 micrograms/L in the 50 to 59, 60 to 69, and 70 to 79 years age groups, respectively, and the reference mean maximal uroflow rates was 14.8 mL/s. CONCLUSIONS: Although controversial, our experience with prostate screening was generally positive. As far as our population is concerned, the free prostate screening exercise generated publicity, and succeeded in enhancing public awareness for better prostate health.

Aged↗
PubMed1992

Necrotising fasciitis: an entity revisited.

Necrotising fasciitis is a disease that still carries a high morbidity and mortality despite our better understanding and advances in treatment since 1924 when Meleney first studied it. In our Department of Orthopaedics, this condition appears to be on the increase, and we therefore felt this entity deserved a restudy. Since 1985, 15 cases were seen, of which 10 were encountered in 1989. There were no recorded case prior to 1985. Our initial results show that the background and outcome parallel that of previous authors. Most were elderly with some form of underlying chronic disease. The duration from symptom onset to presentation was short, with many being in a state of septicaemia at the time of admission with fever, metabolic acidosis and marked leucocytosis. Repeated desloughings were common, and four ended up with some form of limb amputation. As with Meleney's study, the consistent pathogen cultured was B-haemolytic streptococcus. Our recommendation is that we should be more aware of this entity in view of its fulminant course, with early and aggressive surgical intervention being the keystone to management.

Fasciitis↗
PubMed1978

The alternate respiratory pathway of Candida albicans.

Candida albicans contains a cryptic cyanide and antimycin A insensitive respiratory system. This alternate oxidase was found (i) at all growth rates from mu = 0.05 to 0.26 in a chemostat culture and (ii) in both mycelial and yeast forms of the organism. Neither chloramphenicol nor cycloheximide prevented the expression of the alternate oxidase. Salicylhydroxamic acid was a potent inhibitor of the cyanide insensitive respiration. The respiration of mitochondria grown in the presence of antimycin A was not inhibited by cyanide or antimycin A but was inhibited by salicylhydroxamic acid.

Antifungal Agents↗