Membranous and crescentic glomerulonephritis in a patient with anti-nuclear and anti-neutrophil cytoplasmic antibodies.
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Antibodies, Antineutrophil Cytoplasmic↗
Biomedical subjects
A Chang
Publications and source records attributed to A Chang.
The relationship between specific tissue lesions and pain severity in persons with knee osteoarthritis.
INTRODUCTION: Pain is the most common symptom in knee osteoarthritis (OA), a leading cause of chronic disability, and a major source of the disability attributable to OA in general. Pain severity in knee OA is variable, ranging from barely perceptible to immobilizing. The knee lesions that contribute to pain severity have received little attention. OBJECTIVE: To examine whether worse pathology of specific knee tissues - i.e. cartilage, bone (attrition, cysts, bone marrow lesions, and osteophytes), menisci (tears and subluxation), ligaments, and synovium (synovitis/effusion) - is associated with more severe knee pain. METHODS: One hundred and forty-three individuals were recruited from the community with primary (idiopathic) knee OA, with definite tibiofemoral osteophytes in at least one knee, and at least some difficulty with knee-requiring activity. Knee magnetic resonance (MR) images were acquired using coronal T1-weighted spin-echo (SE), sagittal fat-suppressed dual-echo turbo SE, and axial and coronal fat-suppressed, T1-weighted 3D-fast low angle shot (FLASH) sequences. The whole-organ magnetic resonance imaging (MRI) scoring (WORMS) method was used to score knee tissue status. Since summing tissue scores across the entire joint, including regions free of disease, may dilute the ability to detect a true relationship between that tissue and pain severity, we used the score from the worst compartment (i.e. with the poorest cartilage morphology) as our primary approach. Knee pain severity was measured using knee-specific, 100 mm visual analogue scales. In analyses to evaluate the relationship between knee pain severity and lesion score, median quantile regression was used, adjusting for age and body mass index (BMI), in which a 95% CI excluding 0 is significant. RESULTS: The increase in median pain from median quantile regression, adjusting for age and BMI, was significant for bone attrition (1.91, 95% confidence interval (CI) 0.68, 3.13), bone marrow lesions (3.72, 95% CI 1.76, 5.68), meniscal tears (1.99, 95% CI 0.60, 3.38), and grade 2 or 3 synovitis/effusion vs grade 0 (9.82, 95% CI 0.38, 19.27). The relationship with pain severity was of borderline significance for osteophytes and cartilage morphology and was not significant for bone cysts or meniscal subluxation. Ligament tears were too infrequent for meaningful analysis. When compared to the pain severity in knees with high scores for both bone attrition and bone marrow lesions (median pain severity 40 mm), knees with high attrition alone (30 mm) were not significantly different, but knees with high bone marrow lesion without high attrition scores (15 mm) were significantly less painful. CONCLUSION: In persons with knee OA, knee pain severity was associated with subarticular bone attrition, bone marrow lesions, synovitis/effusion, and meniscal tears. The contribution of bone marrow lesions to pain severity appeared to require the presence of bone attrition.
Aged↗
The prevalence of low vision and blindness in a Canadian inner city.
PURPOSE: To ascertain the prevalence and primary causes of visual impairment in a sample of patients from Vancouver's downtown eastside (VDES). MATERIALS AND METHODS: A total of 200 patients seeking nonophthalmic medical care at the Vancouver Native Health Society (VNHS) clinic in Vancouver's inner city (downtown eastside) participated in this observational case-series study. For each participant, we obtained demographic information, a medical and ocular history, and performed a complete eye exam. The prevalence of visual disability using standard North American criteria was reported. Causes of visual loss were also reported based on Canadian National Institute for the Blind (CNIB) guidelines. RESULTS: A total of 200 patients participated in our study. The median age of our sample was 46 years, 69% were male. There were very high rates of comorbid medical conditions including HIV, Hepatitis B/C, IV drug use, and diabetes. The raw prevalence of visual disability based on best-corrected visual acuity (BCVA) was 500 per 10,000; this was over nine times greater than in the general Canadian population. The raw prevalence rate of 'presenting visual disability' based on presenting visual acuity (PVA) was 2400 per 10,000. Major causes of visual disability were cataract and retinal disease. Although age-related macular degeneration and diabetic retinopathy represent major causes of vision loss in North America, no cases were noted in our sample. CONCLUSION: The overall prevalence of visual disability was alarmingly high in this disadvantaged community. These results identify both ophthalmic disease and access to refraction and prescription spectacles as a significant health concern among people living in the VDES.
Adolescent↗
Self-appraisal hierarchical task analysis of laparoscopic surgery performed by expert surgeons.
BACKGROUND: Evaluation of technical skill is notoriously difficult because of the subjectivity and time-consuming expert analysis. No ongoing evaluation scheme exists to assess the continuing competency of surgeons. This study examined whether surgeons' self-assessment accurately reflects their actual surgical technique. METHODS: Hierarchical task analysis (HTA) of laparoscopic cholecystectomy was constructed. Ten expert surgeons were asked to modify the HTA for their own technique. The HTAs of these surgeons then were compared with their actual operations, which had been recorded and assessed by two observers. RESULTS: A total of 40 operations were assessed. All the gallbladders subjected to surgery were classified as grades 1 to 3. The mean interrater reliability for the two observers had a k value of 0.84 (p < 0.05), and the mean intrarater reliability between surgeons and observers had a k value of 0.79 (p < 0.05). CONCLUSIONS: Surgeons' self-evaluation is accurate for technical skills aspects of their operations. This study demonstrates that self-appraisal using HTA is feasible, accurate, and practical. The authors aim to increase the numbers in their study and also to recruit residents.
Adult↗
A clinicopathologic study of thrombotic microangiopathy in the setting of IgA nephropathy.
BACKGROUND: IgA nephropathy is the most common glomerulonephritis in the world. Thrombotic microangiopathy occurs in a number of clinical settings, including but not limited to thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, malignant hypertension, anti-phospholipid antibody syndrome and radiation nephropathy. Renovascular complications, such as thrombotic microangiopathy, in the setting of IgA nephropathy may be overlooked and their significance as a concomitant histologic finding is unclear. METHODS: We conducted a clinicopathologic study to understand the possible relationship between IgA nephropathy and a concurrent thrombotic microangiopathy injury process. We identified 10 patients with an established diagnosis of IgA nephropathy and concurrent findings of thrombotic microangiopathy based on their renal biopsies. RESULTS: Six patients presented with malignant hypertension, while three others had severe hypertension (> or = 100 mmHg, diastolic). Five patients had nephrotic-range proteinuria. Seven patients had occasional arteriolar thrombi identified by light microscopy and prominent glomerular subendothelial space widening by electron microscopy, while three patients demonstrated only ultrastructural features of thrombotic microangiopathy. Other possible etiologic causes of thrombotic microangiopathy were not identified with the available clinical information. CONCLUSION: Our study suggests that a thrombotic microangiopathy injury, when present, is usually found in advanced stages of IgA nephropathy and can be associated with severe proteinuria. Although other possible causes of thrombotic microangiopathy, such as anti-phospholipid antibody syndrome, were excluded in only two patients, the thrombotic microangiopathy injury process may be a cause or a consequence of the severe hypertension encountered in most of the patients which, in turn, may be a consequence of the disease progression of IgA nephropathy.
Adult↗
Practical assay issues with the PERT/PBRT assay: a highly sensitive reverse transcriptase assay.
Product safety testing for retroviruses can be achieved by a panel of screening assays, including electron microscopy, viral gene specific PCRs, virus propagation, and detection of reverse transciptase activity. The application of PCR-based reverse transcriptase assays (PERT) that are approximately a million-fold more sensitive than conventional nucleotide incorporation assays in the testing of biologicals is described. Use of PERT assays can be applied to three areas: (i) screening for adventitious retrovirus contamination; (ii) detecting and quantifying endogenous viral particle load and (iii) monitoring levels of infectious retrovirus generation in cell lines that contain endogenous retroviruses.
Animals↗
Neuropathology of fragile X-associated tremor/ataxia syndrome (FXTAS).
Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder that affects carriers, principally males, of premutation alleles (55-200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene. Clinical features of FXTAS include progressive intention tremor and gait ataxia, accompanied by characteristic white matter abnormalities on MRI. The neuropathological hallmark of FXTAS is an intranuclear inclusion, present in both neurons and astrocytes throughout the CNS. Prior to the current work, the nature of the associations between inclusion loads and molecular measures (e.g. CGG repeat) was not defined. Post-mortem brain and spinal cord tissue has been examined for gross and microscopic pathology in a series of 11 FXTAS cases (males, age 67-87 years at the time of death). Quantitative counts of inclusion numbers were performed in various brain regions in both neurons and astrocytes. Inclusion counts were compared with specific molecular (CGG repeat, FMR1 mRNA level) and clinical (age of onset, age of death) parameters. In the current series, the three most prominent neuropathological characteristics are (i) significant cerebral and cerebellar white matter disease, (ii) associated astrocytic pathology with dramatically enlarged inclusion-bearing astrocytes prominent in cerebral white matter and (iii) the presence of intranuclear inclusions in both brain and spinal cord. The pattern of white matter pathology is distinct from that associated with hypertensive vascular disease and other diseases of white matter. Spongiosis was present in the middle cerebellar peduncles in seven of the eight cases in which those tissues were available for study. There is inclusion formation in cranial nerve nucleus XII and in autonomic neurons of the spinal cord. The most striking finding is the highly significant association between the number of CGG repeats and the numbers of intranuclear inclusions in both neurons and astrocytes, indicating that the CGG repeat is a powerful predictor of neurological involvement in males, both clinically (age of death) and neuropathologically (number of inclusions).
Age of Onset↗
The impact of past alcohol use on treatment response rates in patients with chronic hepatitis C.
BACKGROUND: Studies have shown that past alcohol consumption reduces response rates in patients with chronic hepatitis C treated with interferon monotherapy. AIM: To clarify the importance of alcohol consumption on response rates in patients undergoing treatment with pegylated interferon and ribavirin. METHODS: In a single centre, prospective study, median daily alcohol consumption (determined by previously validated method) and quartiles of alcohol consumption were calculated. Univariate and binary logistic regression analyses were performed using treatment response status as the dependent variable. RESULTS: Overall, in an intention-to-treat analysis, 34 of 115 patients (30%) responded to treatment. In univariate analysis, black patients, especially those with hepatitis C virus genotype 1, high viral load and low alanine aminotransferase were significantly less likely to respond. Predictors of response by regression analysis included alcohol <30 g/day (OR=3.02, 95% CI: 1.02-8.93; P=0.04), non-genotype 1 status (OR=1.98, 95% CI: 1.03-3.80; P=0.04) and non-black race (OR=2.79, 95% CI: 1.33-5.85; P=0.006). CONCLUSIONS: Median daily alcohol use >30 g/day is associated with failure to respond to pegylated interferon and ribavirin for treatment of hepatitis C. Past alcohol use should be evaluated when considering treatment for hepatitis C.
Adult↗
Technical skills errors in laparoscopic cholecystectomy by expert surgeons.
BACKGROUND: Performing laparoscopic surgery involves a complex cascade of cognitive skills, which may inherently have a constant technical error rate. We assess generic and specific minor and major error rates in laparoscopic cholecystectomies (LCs) performed by consultant surgeons. METHODS: Checklists of generic (11) and specific technical minor (six) and major events (eight) were devised for LCs. Two experienced surgeons assessed each full-length operation blindly and independently. RESULTS: A total of 37 LCs were performed by eight consultants. There were no major intraoperative or postoperative complications. Mean inter-rater reliability was kappa = 0.91 (range 0.80-0.98) for each of the error categories. Error rates were generic (27/407) 6.6%, minor (59/222) 26.6%, and major (8/296) 2.7%, respectively. There was a significant statistical difference between the minor error group and the other groups, p <or= 0.05. CONCLUSIONS: Performing laparoscopic surgery may always have a background technical error rate. Our present study demonstrates a migration of surgical technical errors in expert laparoscopic surgeons. The surgeons migrate technically when they execute a high rate of procedure-specific minor errors. However, when it comes to the major fundamental aspects of the operation, they dynamically adapt and migrate away from performing major technical errors. We aim to continue the study to increase cases, assess trainees as well, and also explore other factors that may affect the surgeon when executing surgical technical tasks.
Adult↗
Fetal growth velocities in Hong Kong Chinese infants.
Few studies have investigated the velocities of fetal growth. The aim of the present study was to determine the pattern of 'fetal' growth velocities in a Chinese population. The gestation-specific measurements of the body weight, body length and head circumference in a representative sample of 5,045 male and 4,484 female newborns delivered between 26 and 42 weeks of gestation at 12 hospitals in Hong Kong were obtained. Peak growth velocity occurred before 30 weeks of gestation for head circumference, at week 30 for length and at week 30 for weight. When compared with data obtained from a French population, a significant difference in the growth velocity for body weight was observed below 32 weeks between French and Chinese infants, suggesting an ethnic difference in fetal growth of this parameter.
Anthropometry↗
Normative data of penile length for term Chinese newborns.
Careful examination and assessment of penile length in the newborn is important because micropenis is associated with hypothalamic disorders. This prospective cross-sectional study was designed to establish the norm of penile length for term Hong Kong Chinese newborns. 4,628 full-term healthy male newborns were enrolled in the study. Penile length was measured from pubic ramus to the tip of the glans penis by placing the end of a straight edge ruler against the pubic ramus. A gestation-associated graph of 3rd, 10th, 25th, 50th, 75th, 90th and 97th centiles for the penile length was created. The penile length was significantly correlated with gestational age, birth weight and body length. When compared with published data for other populations, Hong Kong newborns have significantly shorter penile length. The norm of the penile length is useful in diagnostic and therapeutics for the ethnic Chinese male newborns.
Asian People↗
Bimodal assessment of laparoscopic suturing skills: construct and concurrent validity.
BACKGROUND: The assessment of technical skills should provide objective feedback and judge suitability of progress during training. The aim of this study was to validate two objective assessment techniques for laparoscopic suturing and demonstrate a correlation between them. METHODS: Six experts, seven surgeons skilled in laparoscopic suturing, and 13 with no laparoscopic suturing skills were asked to place two or three intracorporeal sutures on a synthetic suture pad. The latter group was given video-based instructions prior to the execution of the sutures. Ergonomic conditions were standardized for all subjects. The procedures were recorded on videotape and two blinded observers rated the first suture of each subject on a 29-point checklist. A motion analysis system, Imperial College Surgical Assessment Device, was used to assess psychomotor skills. RESULTS: There was a significant difference in the time taken (p = 0.000) and total path length (p = 0.000) per suture across the groups. There were also a significant difference in the total checklist score (p = 0.000) and its individual categories. The was a strong correlation between the total path length and the total checklist score (coefficient, 0.78; p < 0.001). CONCLUSIONS: A combination of the motion analysis system and the checklist would make the process of formative feedback during the learning of intracorporeal suturing objective and comprehensive.
Clinical Competence↗
Inhaled cromones for prolonged non-specific cough in children.
BACKGROUND: Non-specific cough is defined as non-productive cough in the absence of identifiable respiratory disease or known aetiology. It is commonly seen in paediatric practice. These children are treated with a variety of therapies including inhaled cromones. OBJECTIVES: To determine the efficacy of inhaled cromones in the management of prolonged non-specific cough in children. SEARCH STRATEGY: The Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register Collaboration and Cochrane Airways Group, MEDLINE and EMBASE databases were searched. Australian representative of the relevant pharmaceutical company was contacted. The latest searches were performed in October 2003. SELECTION CRITERIA: All randomised controlled trials comparing inhaled cromones with a placebo medication. DATA COLLECTION AND ANALYSIS: Results of searches were reviewed against pre-determined criteria for inclusion. No eligible trials were identified and thus no data were available for analysis. One single arm open trial in children and one small randomised controlled trial in adults were reported. MAIN RESULTS: No randomised-controlled trials that examined the efficacy of inhaled cromones in the management of prolonged non-specific cough in children were found. In the non randomised trials above, a significant effect was seen within two weeks of therapy. REVIEWERS' CONCLUSIONS: There is currently an absence of evidence to support the routine use of inhaled cromones for symptomatic control of non-specific cough in children. Further research examining the effects of this intervention is needed.
Administration, Inhalation↗
Auricular anthropometry of Hong Kong Chinese babies.
OBJECTIVES: To provide a database of the auricular measurements of Chinese infants born in Hong Kong. DESIGN: Prospective cross-sectional study. SETTING AND SAMPLE POPULATION: A total of 2384 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from October 1998 to September 2000, were included in the study. The range of gestation was 33-42 weeks. MEASUREMENTS AND RESULTS: Measurements included ear width (EW), ear length (EL) and ear position (EP). The data show generally higher values for males in the parameters measured. When compared with previously published data for Caucasian and Jordanian term babies, Chinese babies have shorter EL. The ears were within normal position in nearly all our infants. CONCLUSION: The human ear appears to grow in a remarkably constant fashion. This study establishes the first set of gestational age-specific standard of the ear parameters for Chinese new-borns, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these ear parameters.
Asian People↗
Australasian CD34+ quality assurance program and rationale for the clinical utility of the single-platform method for CD34+ cell enumeration.
BACKGROUND: Enumeration of CD34(+) cells should be accurate and comparable between institutions, particularly when making clinical decisions, evaluating data, and in clinical trials. An Australasian CD34(+) quality assurance program (QAP) has been established to compare CD34(+) cell results and method (Part 1). Unexpected variation in WBCCs led to Part 2 of this report. METHODS: Part 1: Methods reagents and results were evaluated for 12 QAP samples analyzed by 36-43 centers. Part 2: The effects of different anticoagulants on WBCC of 12 peripheral blood samples (PBs) were compared using three cell counters. To test the validity of applying the conclusions to clinical samples, the WBCCs of leukapheresed products and BM harvest were also compared. RESULTS: Part 1: In some samples, WBCCs determined by certain cell-counter groups were significantly different. Results for percentage of CD34(+) and CD34(+)/microL suggest that standardization on the lyse-no-wash and single platform (SP) method reduces variation of results between institutions. Part 2: Using different counters, PB WBCC in ACD-A showed greater variation than the same PB in EDTA. For PB in different anticoagulants, the extent of difference in WBCC for the same PB is dependent on the counter used. DISCUSSION: This CD34 QAP has identified ACD-A as an additional factor that contributes to the disparate WBCCs, which may further compromise the accuracy of CD34(+) cell counts obtained by the dual platform (DP) method, especially for leukapheresed products. In order to achieve greater accuracy within individual institutions, as well as permitting more reliable inter-institutional comparisons, our data supports the adoption of the SP as the standard method for CD34(+) cell enumeration.
Anticoagulants↗
von Willebrand disease: laboratory aspects of diagnosis and treatment.
von Willebrand disease is the most common inherited bleeding disorder in humans. VWD can be classified into three major types, designated Types 1, 2 and 3; Type 2 can be further separated into subtypes 2A, 2B, 2M and 2N. The diagnosis of VWD requires a personal and family history of bleeding and confirmation by laboratory analysis. Although Types 2 and 3 are relatively straightforward to diagnose, there may be a risk of overdiagnosis of Type 1 because of an overlap within the normal range. We also report on the clinical profile and diagnosis of VWD in a South American cohort of patients and on the in vitro characteristics of some factor concentrates available for treatment of VWD.
Adolescent↗
Multiple endocrine neoplasia type 2B in a Chinese patient.
Multiple endocrine neoplasia type 2B syndrome is rarely reported in Chinese patients. A 25-year-old Chinese male presented with full-blown clinical features of this syndrome, including bilateral phaeochromocytomas, medullary thyroid carcinoma, and characteristic phenotypic features. One-stage surgical treatment was performed and subsequent genetic analysis confirmed a point mutation at codon 918 in exon 16 of the RET proto-oncogene. The mutation was arising de novo as there was no corresponding mutation found in both his parents or younger sister. Data published to date suggest there is no difference in the genetic and pathophysiologic basis, nor clinical characteristics of multiple endocrine neoplasia type 2B in Chinese patients. As the disease can be lethal, early diagnosis by prompt recognition of the characteristic phenotypic features followed by surgical treatment should improve the outcome. Family screening is essential to identify at-risk family members for prophylactic treatment.
Adrenalectomy↗
Validity and reliability of a virtual reality upper gastrointestinal simulator and cross validation using structured assessment of individual performance with video playback.
BACKGROUND: This study aims to evaluate the ability of an upper gastrointestinal virtual reality simulator to assess skills in endoscopy, and to validate its metrics using a video-endoscopic (VES) technique. METHODS: The 32 participants in this study were requested to undertake two cases on the simulator (Simbionix, Israel). Each module was repeated twice. The simulator's metrics of performance were used for analysis. two blinded observers rated performance watching the simulator's playback feature. RESULTS: There were 11 novices (group 1), 11 trainees with intermediate experience (10-50 procedures, group 2), and 10 experienced endoscopists (>200 procedures, group 3). There was a significant difference in the total time required to perform the procedure (p < 0.001), percentage of mucosa visualized (p < 0.001), percentage of pathologies visualized (p < 0.001), and number of inappropriate retroflexions (p = 0.015) across the three groups. The reliability of assessment on the simulator was greater than 0.80 for all parameters. The VES assessment also was able to discriminate performance across the groups (p < 0.001). There was a significant correlation between the VES score and the percentage of mucosa visualized (rho = 0.60; p < 0.001). CONCLUSIONS: The upper gastrointestinal simulator may be a useful tool for determining whether a trainee has achieved a desired level of competence in endoscopy. The next step will be to validate the VES score in real procedures.
Endoscopy, Gastrointestinal↗