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K L Chan

Publications and source records attributed to K L Chan.

At least 127 records · Page 7Linked to original sources
PubMed1997

A prospective study to assess the frequency of familial clustering of congenital bicuspid aortic valve.

OBJECTIVES: This study sought to determine the rate of familial occurrence of congenital bicuspid aortic valve (BAV) by using echocardiography to screen family members. BACKGROUND: Congenital BAV is a common anomaly that carries with it a significant risk of potential long-term cardiac complications. Despite several reports of the familial occurrence of BAV, the condition is not generally considered to be inherited. METHODS: Thirty consecutive patients with echocardiographically documented congenital BAV were interviewed to construct three-generation family pedigrees. All first-degree relatives were contacted to undergo echocardiography to specifically determine aortic valve morphology. RESULTS: Of the 210 first-degree relatives, 190 (90.5%) agreed to undergo echocardiography. Four members had technically difficult studies. Of the remaining 186 subjects, 17 (9.1%) were identified as having BAV; 11 (36.7%) of the 30 families had at least one additional member with the condition. The male/female ratio of affected members in the 11 families was 1. In one family, two instances of male-to-male transmission were observed. The distribution of BAV in the majority of multiplex families is compatible with autosomal dominant inheritance with reduced penetrance. CONCLUSIONS: We demonstrated a high incidence of familial clustering in congenital BAV. We believe that the high rate of occurrence of the condition in immediate relatives justifies echocardiographic screening of first-degree relatives to anticipate and prevent future complications associated with this common cardiac malformation.

Aortic Valve↗
PubMed1997

A high-performance liquid chromatography analysis of plasma artemisinin using a glassy carbon electrode for reductive electrochemical detection.

A high-performance liquid chromatography assay equipped with a glassy carbon electrode for electrochemical detection (HPLC-ECD) was developed at reductive mode for the analysis of artemisinin, the antimalarial drug from Artemisia annua (Asteraceae) in human plasma. This method was selective, sensitive, and produced satisfactory recovery, precision, and accuracy. Analysis of plasma samples from 8 male volunteers given 10 mg kg-1 of artemisinin orally as an aqueous suspension showed a mean peak plasma concentration (Cmax) of 580.89 ng ml-1 +/- 88.64 SD at 2.5 h +/- 0.5 SD after dosing, and the mean area under the plasma concentration-time curve (AUC0-infinity) was 2227.57 ng h ml-1 +/- 677.22 SD. In addition, the elimination rate constant (Ke), elimination half-life (t1/2), and apparent volume of distribution (Vd) were calculated to be 0.2971 h-1 +/- 0.0644 SD, 2.42 h +/- 0.46 SD, and 16.26 l kg-1 +/- 3.44 SD, respectively.

Adult↗
PubMed1997

Inflammatory pseudotumor of epididymis and Epstein-Barr virus: a study of two cases.

Inflammatory pseudotumor (IP) is an uncommon tumor-like lesion of unknown etiology. Two cases of IP of the epididymis were identified in our hospital file. Having read a recent report on finding Epstein-Barr virus (EBV) in some cases of IP in lymph node, spleen and liver, the two cases of epididymal IP were tested for EBV-encoded small nuclear RNA 1 and 2 by in-situ hybridization. The absence of EBV RNA suggests that IP of epididymis may be etiologically distinct from that occurring in the organs of the reticuloendothelial system.

Adult↗
PubMed1997

Ileoileocolic intussusception in children: diagnosis and significance.

The ileoileocolic type of childhood intussusception is difficult to diagnose pre-operatively and is associated with increased morbidity. This study describes the clinical and imaging features of 10 consecutive ileoileocolic intussusceptions diagnosed ultrasonically in 10 patients over a 36 month period. Ultrasound-guided hydrostatic reduction using Hartmann's solution was attempted in all 10 patients. Clinical and imaging features were compared with those of 28 ileocolic intussusceptions in 25 patients diagnosed and treated using the same methods during the same period. Most of the clinical and plain radiographic features of the patients with the ileoileocolic and ileocolic types of intussusception were similar. The two types of intussusception had the classical doughnut or pseudokidney, or both, signs on pre-reduction ultrasound scans. During the reduction process, when surrounded by fluid within the caecal lumen, the ileoileocolic type of intussusception had a typical complex appearance due to frond-like loops of intussuscepted small bowel. This finding was present in all cases. The hydrostatic reduction rate was only 10% (1/10) for ileoileocolic intussusception, compared with 92.9% (26/28) for the ileocolic type. All unsuccessfully-reduced cases underwent surgery, with surgical confirmation of the intussusception type in all cases. Only one patient was found to have a lead point, caused by a Meckel's diverticulum. In conclusion, the diagnosis of ileoileocolic intussusception can be made pre-operatively and these patients require surgical management.

Child↗
PubMed1997

Treatment of biliary atresia by portoenterostomy and liver transplantation: The Queen Mary Hospital, Hong Kong experience.

Ninety three out of 96 patients with biliary atresia (BA) underwent Kasai 1 portoenterostomy and 11 children subsequently underwent 12 liver transplantation (LTX) procedures which included 8 living related liver transplants (LRLT), 3 reduced-size liver transplants (RSLT) and 1 orthotopic liver transplantation (OLT). During a follow-up period of 3-206 months (mean, 73 months) after portoenterostomy and 3-63 months after LTX, 50% of 96 patients are alive and well with total clearance of jaundice while 12% are mildly jaundiced, 10% are deeply jaundiced and 28% have died. Two of the 3 patients who did not undergo portoenterostomy and 25 from the portoenterostomy group have died. Of the latter group, 22 deaths occurred before, and 3 after the introduction of LTX therapy respectively. Of the 68 long-term survivors, 32 are less than 5, and 36 are 6-17 years old. Complete clearance of jaundice was achieved in 55% of patients irrespective of whether portoenterostomy was initially performed at < 10 or between 10 and 12 weeks. Portoenterostomy performed beyond 13 weeks was associated with declining results. We conclude that (1) portoenterostomy combined with liver transplantation, when indicated, has given patients with BA a much better prognosis and (2) pediatric LTX in our institute is a well established procedure with 100% patient and 88% primary graft survival.

Age Factors↗
PubMed1997

Feasibility and complications of single-plane and biplane versus multiplane transesophageal imaging: a review of 2947 consecutive studies.

OBJECTIVE: To analyze and compare the incidence of procedural complications and failure of intubation with various sizes of probes used in transesophageal echocardiography. DESIGN: Retrospective chart review. SETTING: A Canadian, tertiary care hospital. PATIENTS: A total of 2947 consecutive transesophageal echocardiographic patient examinations between January 1992 and March 1996 at the University of Ottawa Heart Institute, Ottawa, Ontario. RESULTS: The multiplane probe (MP) was used in 1274 studies, biplane (BP) in 1642 and single plane (SP) in 31. Data for BP and SP were combined because of their similar size. Complications or failed intubation occurred in 86 studies (2.9%). There were 53 complications (1.8%) and 40 failed intubations (1.4%). Seven patients (0.3%) had both. Complications were death in one, tracheal intubation or bronchospasm in nine, bleeding in nine, angina in two, pulmonary edema in two, superficial thrombophlebitis in two, supraventricular tachycardia in one and minor adverse events in 27. Complications were unrelated to the choice of probe (MP 2%, BP and SP 1.7%, not significant). Failure of intubation (40 cases) was more common with MP than with BP and SP (2.3% versus 0.7%, P = 0.0003, OR 3.5, 95% CI 1.7 to 7.5). The main reasons for failure were cervical spondylosis in 16 patients and hypersensitive pharynx despite topical anesthesia and sedation in 13 patients. Of 21 cases of failed MP intubation, 16 (76%) were subsequently successful with BP. CONCLUSIONS: Serious complications with transesophageal echocardiography, although infrequent, do occur. The MP carries a 3.5-fold increased risk of failed intubation. In the majority of failures, successful intubation can be achieved with a smaller probe.

Echocardiography, Transesophageal↗
PubMed1997

Furunculosis.

Explore the source record for details and available documents.

4-Quinolones↗
PubMed1997

Electrophoretic variations of peptidase E (PEPE) in characterizing clones and isolates of Plasmodium falciparum from different geographical areas.

Six clones were obtained from each Plasmodium falciparum (Welch, 1897) isolate from different geographical areas, Gombak A (Malaysian), Gombak C (Malaysian), ST 9 (Malaysian, ST 12 (Malaysian), ST 85 (Malaysian, ST 148 (Malaysian), Gambian (African) and TGR (Thailand) isolates using the limiting dilution method (Rosario 1981). Forty-eight clones were obtained and were characterized by an electrophoresis isoenzyme analysis of PEPE (Peptidase E) (EC. 3.4.11 or 13). Results showed that they were pure clones as they were monovariant with regards to this enzyme unlike their parent isolates which were divariant.

Aminopeptidases↗
PubMed1997

Clinics in diagnostic imaging (31). Adrenal neuroblastoma.

A 3-year-old girl presented with epigastric pain and physical examination showed a hard right upper quadrant mass. Urine VMA and HVA were found to be raised. CT scan showed a large mass arising from the right adrenal gland, with necrotic areas and ring calcification There was midline extension. The diagnosis of neuroblastoma was confirmed by bone marrow aspiration biopsy. As the patient had inoperable stage IV neuroblastoma, she was treated with multi-drug chemotherapy. Follow-up CT scan showed excellent response to the chemotherapy, and the tumour was successfully resected. Harvesting of autologous peripheral bone marrow stem cells, megatherapy with Melphalan, and marrow rescue with the stem cells were effective. The child has been well for three years to date. The clinical and imaging features of neuroblastoma, particularly the role of imaging in staging, are emphasised.

Adrenal Gland Neoplasms↗
PubMed1996

Iatrogenic gastric volvulus during transposition for esophageal atresia: diagnosis and treatment.

A baby boy had had transhiatal gastric transposition for wide gap esophageal atresia in another hospital. Postoperatively, repeated vomiting, chest infection, and frequent attacks of dyspnea developed. After reexploration, the cause was not identified and he was referred to the authors' institution. The diagnosis of iatrogenic organoaxial volvulus with gastric outlet obstruction was made because barium meal studies and nuclear isotope scanning showed persistent obstruction of the gastric outlet but upper endoscopy showed no stenosis and a flexible scope could be passed easily into the duodenum. The diagnosis was confirmed by thoracotomy. After full mobilization of the stomach, the gastroesophageal anastomosis was divided and the thoracotomy was closed. The stomach was reduced into the abdomen via laparotomy, and it was tubularized and rerouted retrosternally for anastomosis to the cervical esophagus. Since the operation the patient has been asymptomatic.

Anastomosis, Surgical↗
PubMed1996

Cutaneous stoma in the roux limb of hepaticojejunostomy (hepaticocutaneous jejunostomy): useful access for intrahepatic stone extraction.

A cutaneous stoma in the Roux limb of hepaticojejunostomy (hepaticocutaneous jejunostomy) was used for stone extraction in two children who had hepatolithiasis (14.5 and 15.5 years, respectively) after operation for choledochal cysts. In constructing the hepaticocutaneous jejunostomy, a short, straight proximal limb from the skin to the bilioenteric anastomosis is mandatory. It provides a pathway, superior to the T-tube tract, for repeated stone extraction, which can be performed under sedation, thus obviating repeat laparotomies. The stoma allows flexible choledochoscopy, balloon dilatation of intrahepatic duct strictures, and extraction of intrahepatic stones using grasping forceps, baskets, and balloons. The electrohydraulic lithotriptor may be applied to fragment larger stones.

Adolescent↗
PubMed1996

Horseshoe kidney with bilateral single system ectopic ureters.

A horseshoe kidney, associated with bilateral single system ectopic ureters in a 9-month-old boy, is reported. The right ureteric orifice was located near the midline of a deformed trigone while the grossly dilated left ureter inserted into the posterior urethra. Imaging defined this rare combination of urological anomalies prior to surgical treatment.

Abnormalities, Multiple↗
PubMed1996

Sonographically guided hydrostatic reduction of childhood intussusception using Hartmann's solution.

OBJECTIVE: Currently, the standard methods for therapeutic reduction of intussusception in children involve considerable ionizing radiation. This study tested the effectiveness of sonographically guided hydrostatic reduction of intussusception using Hartmann's solution, a fluid with near-physiologic composition. SUBJECTS AND METHODS: Between March 1, 1994, and January 31, 1996, all children clinically suspected of having intussusception were evaluated by sonography. Those with positive findings on sonography were entered into the study and underwent confirmatory sonographically guided meglumine diatrizoate enema. During continuous sonographic monitoring, we used Hartmann's solution for attempted reduction of intussusception. Criteria for successful reduction were disappearance of the intussusceptum and passage of fluid through the ileocecal valve. Another sonographically guided meglumine diatrizoate enema was used to confirm successful reduction. RESULTS: We detected 25 consecutive intussusceptions in 22 patients. The patients were 12 girls and 10 boys, with a mean age of 14 months (range, 1-72 months). Sonograms revealed in all patients doughnut or pseudokidney signs or both. The sites of intussusception were the transverse colon (17 of 25), hepatic flexure (4 of 25), ascending colon (2 of 25), splenic flexure (1 of 25), and descending colon (1 of 25). Other findings were dilated fluid-filled small bowel (11 of 25) and free intraperitoneal fluid (9 of 25). The success rate of our sonographically guided attempts at hydrostatic reduction was 76% (19 of 25). Success was proven by meglumine diatrizoate enema in all 19 patients. The mean time of the reduction procedure was 18 min (range, 2-45 min). No complications occurred. All six patients in whom hydrostatic reduction was unsuccessful underwent surgery. Five of these patients had ileoileocolic intussusceptions. On sonography, when surrounded by fluid, ileoileocolic intussusceptions had a typically complex, fronded appearance. The remaining patient in whom hydrostatic reduction was unsuccessful had ileocolic intussusception. Of six ileoileocolic intussusceptions, one was hydrostatically reduced and a second was converted into an ileoileal intussusception before requiring surgery. The other four intussusceptions were surgically treated. CONCLUSION: Our data suggest that sonographically guided hydrostatic reduction with Hartmann's solution can be used to treat ileocolic intussusception and to diagnose ileoileocolic intussusception.

Catheterization↗
PubMed1996

Electrophoretic variations of enzyme, GDH (NADP-dependent glutamate dehydrogenase)(EC. 1.4.1.4) in characterizing clones and isolates of Malaysian Plasmodium falciparum.

Malaysian, African and Thai Plasmodium falciparum isolates were cultured in vitro by the Trager and Jensen method (1976; 1977) and were later cloned by the limiting dilution method (Rosario, 1981). Forty-eight clones were obtained and were characterized by electrophoretic variations of GDH (NADP-dependent glutamate dehydrogenase)(EC. 1.4.1.4). It was found that they were pure clones because they possessed either GDH-1 or GDH-2 unlike their parent isolates which exhibited both GDH-1 and GDH-2.

Animals↗