Fast DNA fragment sizing in a short capillary column.
Explore the source record for details and available documents.
Activin Receptors, Type I↗
Biomedical subjects
K C Chan
Publications and source records attributed to K C Chan.
Bedside pericardiocentesis under the guidance of transesophageal echocardiography in a 13-month-old boy.
Pericardial effusion is a common sequel to cardiac surgery. Urgent pericardiocentesis is required in the case of cardiac tamponade. In adult patients, most pericardiocentesis is accomplished using transthoracic echocardiographic imaging. However, transthoracic echocardiographic imaging may interfere with the procedure field in children. We report the case of a 13-month-old boy who developed cardiac tamponade resulting in heart failure after surgical repair of tetralogy of Fallot. Urgent pericardiocentesis was safely performed at the bedside under transesophageal echocardiographic guidance. Transesophageal echocardiographic monitoring during pericardiocentesis in children has the advantages of better imaging of pericardial effusion without procedure-field interference.
Echocardiography, Transesophageal↗
Acupuncture for frozen shoulder.
This randomised controlled trial was undertaken to evaluate the effectiveness of acupuncture as a treatment for frozen shoulder. Thirty-five patients with a diagnosis of frozen shoulder were randomly allocated to an exercise group or an exercise plus acupuncture group and treated for a period of 6 weeks. Functional mobility, power, and pain were assessed by a blinded assessor using the Constant Shoulder Assessment, at baseline, 6 weeks and 20 weeks. Analysis was based on the intention-to-treat principle. Compared with the exercise group, the exercise plus acupuncture group experienced significantly greater improvement with treatment. Improvements in scores by 39.8% (standard deviation, 27.1) and 76.4% (55.0) were seen for the exercise and the exercise plus acupuncture groups, respectively at 6 weeks (P=0.048), and were sustained at the 20-week re-assessment (40.3% [26.7] and 77.2% [54.0], respectively; P=0.025). We conclude that the combination of acupuncture with shoulder exercise may offer effective treatment for frozen shoulder.
Acupuncture Therapy↗
Universal antenatal human immunodeficiency virus testing in Hong Kong: consensus statement.
Following the recommendations of the Advisory Council on AIDS, Hong Kong, the Hospital Authority announced plans to introduce universal antenatal screening for human immunodeficiency virus infection and hence, a consensus conference was held to discuss strategies for implementing such screening in Hong Kong. This paper reports the discussions of the consensus conference. The consensus meeting group consisted of 15 clinicians and scientists from Hong Kong, Macau, and Thailand. Seven commonly asked questions concerning mother-to-child transmission of human immunodeficiency virus were selected for discussion by the participating panellists. Information on the laboratory diagnosis of human immunodeficiency virus infection and the efficacy of preventive measures in reducing mother-to-child transmission of human immunodeficiency virus were reviewed. Data from local studies was also presented and discussed. The timing, potential problems, and cost issues involved in testing all pregnant women in Hong Kong for human immunodeficiency virus were then considered.
Adult↗
Effect of temperature on the separation of DNA fragments by high-performance liquid chromatography and capillary electrophoresis: a comparative study.
This study investigates the effect of experimental temperature on the separation of DNA fragments, 21-587 bp, by both high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE). The results show that the temperature plays an important role in the HPLC separation of DNA fragments. The optimum temperature was found to be between 40 and 50 degrees C for HPLC, while 25 degrees C was the optimum temperature for the CE separation. Also, although CE migration times became shorter, efficiency and resolution decreased with an increase in temperature from 25 to 50 degrees C, but the separation was not significantly affected. Also, the optimum HPLC temperature might be different depending on the fragment sizes to be resolved.
Chromatography, High Pressure Liquid↗
Solid-state UV laser-induced fluorescence detection in capillary electrophoresis.
Two solid-state UV lasers were applied to the laser-induced fluorescence (LIF) detection of various groups of compounds after separation by capillary electrophoresis. These lasers are thermoelectric-cooled, highly compact, and inexpensive. Such lasers provide few mW of quasi-continuous wave (CW) power which are sufficient and stable for LIF detection. Native fluorescence detection of tryptophan-containing proteins and peptides and related indoles was achieved at the nM level with the laser operating at 266 nm. Detection of fluorescamine-labeled amino acids and peptides was also possible at the nM level with the laser operating at 355 nm. Amino acids at a concentration as low as 10 ng/mL could be labeled with fluorescamine. Solid-state UV-LIF detection of the tryptic digest of cytochrome c after fluorescamine derivatization was demonstrated.
Amino Acids↗
Arterial switch operation: successful bilateral internal thoracic artery grafting.
Internal thoracic artery grafting in arterial switch operations for transposition of great arteries has been reported for salvage of myocardial ischemia after initial coronary transfer. We report a situation where we opted for primary coronary bypass grafting to avoid an obviously difficult coronary transfer, with successful outcome.
Humans↗
Cemented hemiarthroplasties for elderly patients with intertrochanteric fractures.
The results of 55 consecutive hemiarthroplasties in 54 elderly patients with intertrochanteric fractures were reviewed. The mean age of the patients was 84.2 years (range, 73-99 years). Standard cemented hemiarthroplasty was used and the fractured posteromedial fragment was retained. Two patients were lost to followup and 12 patients died within 6 months of their fractures. The mean length of followup was 13.6 months (range, 6-24.6 months) for the remaining 40 patients (41 hips). Nineteen patients maintained the same walking category as before fracture and eight of these patients had no increase in the dependency on walking aids. The greatest deterioration of walking function occurred in the subgroup of six patients who had a history of confusion and frequent falls. The medical complications are comparable with those described in other series. There were few surgical complications. The authors of this study think that the use of standard cemented hemiarthroplasty is a reasonable alternative to a sliding screw device for the treatment of intertrochanteric fractures. Longer-term studies with larger numbers of patients are required to address the issues of late complications and whether the reconstructions are durable enough for the long-surviving patients.
Activities of Daily Living↗
Peanuts as a source of beta-sitosterol, a sterol with anticancer properties.
Work from our laboratory, as well as others, suggests a protective role of phytosterols (PS), especially beta-sitosterol, from colon, prostate, and breast cancer. Asians and vegetarians consume higher amounts of PS than Western societies. The latter societies have a higher incidence of these cancers than Asians and vegetarians. The aim of this study was to evaluate peanuts and its products as sources of PS in the American diet. Roasted peanuts contain 61-114 mg PS/100 g depending on the peanut variety, 78-83% of which is in the form of beta-sitosterol. Unrefined peanut oil contains 207 mg PS/100 g, which is similar to that of the US Department of Agriculture Nutrient Database. This value is higher than that of unrefined olive oil. Refining these oils results in reduction in PS concentration in the oil. This loss is greater in the case of olive oil than peanut oil. Further refining, such as deodorization, results in significant loss in PS, but hydrogenation after refining has a minimal effect on PS loss. Peanut butter, which represents 50% of the peanuts consumed in the United States, contains 144-157 mg PS/100 g. Peanut flour, which results from partial removal of oil from peanuts, contains 55-60 mg PS/100 g. The data suggest that peanuts and its products, such as peanut oil, peanut butter, and peanut flour, are good sources of PS.
Antineoplastic Agents↗
Tamoxifen for intraductal cancer.
Explore the source record for details and available documents.
Anticarcinogenic Agents↗
A simple two-dimensional high performance liquid chromatography/high performance capillary electrophoresis set-up for the separation of complex mixtures.
A two-dimensional high performance liquid chromatography/capillary electrophoresis (HPLC/CE) instrumental set-up was assembled from commercially available equipment. Fractions of the effluent from the HPLC system are collected into microtiter plates with a microfraction collector. The fractions are then dried under vacuum at room temperature, reconstituted, and analyzed by capillary zone electrophoresis (CZE). This method allows the collection of samples by time, drops, or external signal (peaks). Any size or type of HPLC or CE column can be used with no limitation on the amount of sample injected into the HPLC. Any CE detection, laser-induced fluorescence (LIF), mass spectrometry (MS), ultraviolet (UV) or other, can be used. This set-up is practical, simple, robust and allows the separation of complex mixtures. Preliminary results show the utility of this system for the analysis of protein digest.
Chromatography, High Pressure Liquid↗
How to switch posts without rethreading when tying half-hitches.
Arthroscopically tied stacked half-hitch knots and sliding knots are best locked with half-hitches on alternating posts. It is possible to switch posts without rethreading the suture through the knot tier by flipping the half-hitch. This article describes extra- and intra-articular techniques for flipping half-hitches to switch posts. The post switching is most easily accomplished by transforming the half-hitch to an intermediate flat knot with symmetrical throws. This intermediate step is imperceptible when the sequence of actions is rapid. An over-under half-hitch becomes an under-over half-hitch when the post is switched.
Arthroscopy↗
Postoperative patellar tilt in total knee arthroplasty.
The postoperative tilt of the patella was investigated in 80 consecutive bilateral total knee arthroplasties in 40 patients. We found that the greater the preoperative lateral tilt, the more likely the patella would tilt postoperatively. The obliquity of resection of the patella has a significant effect on the postoperative lateral tilt. Making the patella remnant thicker on the medial side can decrease the postoperative lateral tilt. A limited lateral peripatellar soft tissue release had no discernible effect on the postoperative lateral tilt of the resurfaced patella.
Arthroplasty, Replacement, Knee↗
Indinavir-associated facial lipodystrophy in HIV-infected patients.
The objectives of this study were to document the prevalence of facial lipodystrophy in patients with HIV infection receiving protease inhibitors and to identify associated factors. All patients with HIV infection receiving protease inhibitors seen at an HIV clinic in Hong Kong during a 2-month period, from August to October 1997, were assessed for facial lipodystrophy. Among 29 patients who had been receiving indinavir for 3 months or more, facial lipodystrophy was found in 7 (24%). Facial lipodystrophy in these patients was found to be an isolated event and was not associated with noticeable wasting elsewhere. The development of facial lipodystrophy was not found to be associated with age, sex, ethnicity, route of HIV transmission, CD4 cell count, history of AIDS-defining illness, or concurrent anti-retroviral treatment. Facial lipodystrophy was not observed in patients who had received indinavir for less than 3 months. The condition was also not found in patients taking other protease inhibitors, although this could be due to the small sample size. Prospective study of this condition with a larger sample and with objective anthropomorphic measurements would be desirable. In conclusion, facial lipodystrophy is a common occurrence among patients receiving indinavir, and physicians should be alerted to this condition.
Adult↗
Aortic obstruction caused by device occlusion of patent arterial duct.
A 2 year old girl is reported in whom deployment of the Amplatzer ductal occluder caused significant aortic obstruction, requiring surgical removal of the device. This case emphasises the need for careful echocardiographic and angiographic assessment of the position of the Amplatzer ductal occluder before and after detaching the device from its delivery system, with particular emphasis on the position of the aortic retention ring. Careful assessment of ductal anatomy must guide case selection.
Aortic Diseases↗
Transcatheter closure of atrial septal defect and interatrial communications with a new self expanding nitinol double disc device (Amplatzer septal occluder): multicentre UK experience.
OBJECTIVE: To review the safety and efficacy of the Amplatzer septal occluder for transcatheter closure of interatrial communications (atrial septal defects (ASD), fenestrated Fontan (FF), patent foramen ovale (PFO)). DESIGN: Prospective study following a common protocol for patient selection and technique of deployment in all participating centres. SETTING: Multicentre study representing total United Kingdom experience. PATIENTS: First 100 consecutive patients in whom an Amplatzer septal occluder was used to close a clinically significant ASD or interatrial communication. INTERVENTIONS: All procedures performed under general anaesthesia with transoesophageal echocardiographic guidance. Interatrial communications were assessed by transoesophageal echocardiography with reference to size, position in the interatrial septum, proximity to surrounding structures, and adequacy of septal rim. Stretched diameter of the interatrial communications was determined by balloon sizing. Device selection was based on and matched to the stretched diameter of the communication. MAIN OUTCOME MEASURES: Success defined as deployment of device in a stable position to occlude the interatrial communication without inducing functional abnormality or anatomical obstruction. Occlusion status determined by transoesophageal echocardiography during procedure and by transthoracic echocardiography on follow up. Clinical status and occlusion rates assessed at 24 hours, one month, and three months. RESULTS: 101 procedures were performed in 100 patients (86 ASD, 7 FF, 7 PFO), age 1.7 to 64.3 years (mean (SD), 13.3 (13.9)), weight 9.2 to 100.0 kg (mean 32.5 (23.5)). Procedure time ranged from 30 to 180 minutes (mean 92.4 (29.0)) and fluoroscopy time from 6.0 to 49.0 minutes (mean 16.1 (8.0)). There were seven failures, all occurring in patients with ASD, and one embolisation requiring surgical removal. Immediate total occlusion rate was 20.4%, rising to 84.9% after 24 hours. Total occlusion rates at the one and three month follow up were 92.5% and 98.9%, respectively. Complications were: transient ST elevation (1), transient atrioventricular block (1), presumed deep vein thrombosis (1), presumed transient ischaemic attack (1). CONCLUSIONS: It appears feasible to close interatrial communications and atrial septal defects up to 26 mm stretched diameter safely with the Amplatzer septal occluder. Short term results confirm an early high occlusion rate with no major complications. Careful selection of cases based on the echocardiographic morphology of the ASD and accurate assessment of their stretched diameter is of utmost importance. Further experience with the larger devices and longer term results are required before a firm conclusion regarding its use can be made.
Adolescent↗
A case of extraadrenal pheochromocytoma associated with adrenal cortical nodular hyperplasia and papillary thyroid carcinoma.
A 64-year-old woman was admitted in November, 1996 for fluctuating blood pressure. There was multinodular goiter in her neck. High urine VMA and serum aldosterone were noted. Computed tomography showed an oval lesion in the left adrenal gland. Left adrenalectomy was performed and the pathology was proved to be adrenal cortical nodular hyperplasia. Fluctuating blood pressure and high urine VMA persisted after the operation. CT scan of the abdomen revealed a soft tissue mass in lower abdomen. The patient was admitted again in September, 1997. Laboratory examinations showed normal serum aldosterone, normal plasma renin activity and high urine VMA. Aspiration cytology of the thyroid gland disclosed papillary thyroid carcinoma. [131I]-metaiodobenzylguanidine image revealed a high uptake lesion in the right L-3 paravertebral area. Tumor excision and thyroidectomy were performed. The pathology was reported as extraadrenal pheochromocytoma and papillary thyroid carcinoma. Papillary thyroid carcinoma is rarely associated with pheochromocytoma. To our knowledge, this paper is the first report of a patient with extraadrenal pheochromocytoma associated with papillary thyroid carcinoma and adrenal cortical nodular hyperplasia.
Adrenal Cortex↗
High incidence of nevirapine-associated rash in HIV-infected Chinese.
Explore the source record for details and available documents.
Anti-HIV Agents↗