Biomedical subjects
Publications and source records attributed to W Wong.
Cerebral vasculitis following acute post-streptococcal glomerulonephritis (APSGN) is a rare neurological complication. An 11-year-old girl with biopsy proven APSGN developed an acute seizure disorder. Clinical and computed tomography findings were consistent with vasculitis.
PURPOSE: To investigate ocular complications arising from nephrotic syndrome and/or its treatments in children. METHODS: A cross-sectional study was conducted in a teaching hospital. A total of 31 paediatric patients with nephrotic syndrome were studied. Comprehensive ophthalmic assessments on best-corrected visual acuity, intraocular pressure, slit-lamp and fundus examination were taken. Information regarding histological diagnosis of nephrotic syndrome and its treatment regimen in each patient was reviewed and analysed. RESULTS: Bilateral posterior subcapsular cataracts were detected in three of 29 patients (10.3%) who received steroid therapy. Two had normal vision while one had visual acuity reduced to 6/15 in both eyes. The age of onset of the nephrotic syndrome in these three patients was 2 years, which was significantly younger than those without cataract (5.4 +/- 3.2 years, P < 0.001). Three patients (9.7%) had isolated asymptomatic fundal findings of tortuous and dilated retinal vessels. Hypertensive retinopathy was found in one patient (3.2%). No steroid-induced glaucoma, uveitis, ocular infection, or other eye complications related to the use of steroids or other immunosuppressive agents were noted. CONCLUSIONS: Children who have nephrotic syndrome often require prolonged, intermittent high dose of systemic corticosteroid therapy. Paediatricians should be aware of the potential risk of developing steroid-related complications, especially posterior subcapsular cataract. It appears to have a higher risk when steroid therapy is used in very young patients. Early detection would help to prevent amblyopia development, particularly in the group of immature eyes.
RATIONALE AND OBJECTIVES: The safety and diagnostic efficacy of MultiHance (gadobenate dimeglumine) in the central nervous system (CNS) were evaluated in a double-blind, multicenter, phase III clinical trial. METHODS: Two hundred five patients highly suspected of having a CNS lesion (by previous imaging exam) were enrolled at 16 sites in the United States. Patients were randomized to one of three incremental dosing regimens. Magnetic resonance imaging with Omniscan (gadodiamide) at doses of 0.1 and 0.3 mmol/kg was compared with MultiHance (gadobenate dimeglumine) at doses of 0.05 and 0.15 mmol/kg and at 0.1 and 0.2 mmol/kg. RESULTS: Compared with predose images alone, efficacy was demonstrated in each of the gadobenate dimeglumine and gadodiamide groups (single and cumulative doses) as indicated by the level of diagnostic information, number of lesions detected, and contrast-to-noise ratio measurements. The level of diagnostic information from gadobenate dimeglumine at 0.1 mmol/kg was equivalent to that with gadodiamide at the same dose. One of the two blinded reviewers found equivalence between the gadobenate dimeglumine 0.05 mmol/kg dose and gadodiamide at 0.1 mmol/kg. Both reviewers found the level of diagnostic information to be equivalent after the second dose of contrast for all three dosing regimens. The cumulative doses of gadobenate dimeglumine were well tolerated and as safe as gadodiamide. CONCLUSIONS: Gadobenate dimeglumine is comparable to gadodiamide in terms of safety and efficacy for imaging of CNS lesions, with a possible advantage in imaging applications owing to enhanced T1 relaxivity.
Many factors that drive glomerular and tubulointerstitial fibrogenesis have been identified. These include hemodynamic factors, chemokines, inflammatory mediators, cytokines, and lipids. These strides in knowledge are important in identifying those patients at increased risk of progressive renal disease as well as in developing targets for therapeutic interventions. Identifying 'progressors' is crucial since the distribution of the slope of the glomerular filtration rate of patients with chronic kidney disease is not normal. Some patients appear to progress very rapidly, such as those with diabetes, whereas other patients fail to progress at all. Developing strategies targeted at identifying the fast from the slow progressors is therefore of paramount importance if we are to deploy resources rationally in the management of patients with chronic kidney disease. The use of urinary cytokine markers as predictors of progression of renal disease is reviewed in this paper.
A 14-month-old speyed female Boxer was presented with acute non-weight-bearing lameness in the right forelimb. Radiography revealed separation of the anconeal process, which was thence surgically removed. Histological examination of the anconeal process confirmed a primary fracture. Isolated unilateral anconeal process fracture in the dog is rare and this report includes histopathological findings of a primary anconeal fracture.
AIM: To evaluate the effectiveness of oral erythromycin as a prokinetic agent for the treatment of moderately severe gastrointestinal dysmotility in preterm very low birthweight infants. METHODS: A prospective, double blind, randomised, placebo controlled study in a tertiary referral centre of a university teaching hospital was conducted on 56 preterm infants (< 1500 g) consecutively admitted to the neonatal unit. The infants were randomly allocated by minimisation to receive oral erythromycin (12.5 mg/kg, every six hours for 14 days) or an equivalent volume of placebo solution (normal saline) if they received less than half the total daily fluid intake or less than 75 ml/kg/day of milk feeds by the enteral route on day 14 of life. The times taken to establish half, three quarters, and full enteral feeding after the drug treatment were compared between the two groups. Potential adverse effects of oral erythromycin and complications associated with parenteral nutrition were assessed as secondary outcomes. RESULTS: Twenty seven and 29 infants received oral erythromycin and placebo solution respectively. The times taken to establish half, three quarters, and full enteral feeding after the drug treatment were significantly shorter in the group receiving oral erythromycin than in those receiving the placebo (p < 0.05, p < 0.05 and p < 0.0001 respectively). There was also a trend suggesting that more infants with prolonged feed intolerance developed cholestatic jaundice in the placebo than in the oral erythromycin group (10 v 5 infants). None of the infants receiving oral erythromycin developed cardiac dysrhythmia, pyloric stenosis, or septicaemia caused by multiresistant organisms. CONCLUSIONS: Oral erythromycin is effective in facilitating enteral feeding in preterm very low birthweight infants with moderately severe gastrointestinal dysmotility. Treated infants can achieve full enteral feeding 10 days earlier, and this may result in a substantial saving on hyperalimentation. However, until the safety of erythromycin has been confirmed in preterm infants, this treatment modality should remain experimental. Prophylactic or routine use of this medication for treatment of mild cases of gastrointestinal dysmotility is probably not warranted at this stage.
The importance of gastroesophageal reflux disease (GERD) to managed health care systems cannot be overestimated. It contributes significantly to the use of health care resources, including doctor's services, medication consumption, and diagnostic testing. A roundtable meeting of 13 managed care experts was convened January 23, 2001 in Dallas, to discuss the implications of GERD on the managed care system. The following proceedings are published in five sections. In the first part, Jeffrey Danzig, MD, a gastroenterologist, provides the clinical foundation for the discussion, based on the existing literature and his personal practice.
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A number of environmental factors were used experimentally to enhance myogenesis during muscle regeneration; however, many hormones and growth factors have been shown to have the ability to increase the rate of satellite cell division, but they only work on satellite cells that are already active in many animal experiments. Recently, the crushed muscle extract (CME) of rats was found to be able to trigger dormant adult rat satellite cells to re-enter the cell mytogenic cycle; however, the identity of the active factors present in rat CME remains unknown. In the present study, the CME was fractionated by the strategy of sequential isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with functional analysis by myoblast culture. Two satellite cell-specific myogenic factors were identified and purified from CME by this strategy. One of the factors has a molecular mass of around 7 kDa and another about 39 kDa. The factor of 39 kDa could be retained in heparin-Sepharose column and eluted with phosphate-buffered saline (PBS) containing 1 M NaCl, but the 7 kDa factor did not bind to the heparin column. These two purified myogenic factors could synergistically trigger the proliferation and differentiation of dormant satellite cells, whose progenies subsequently fuse in vitro, or fuse to pre-existing partially damaged muscle fibers to form full repair of the damaged muscle fibers or to form new myotubes to replace the completely damaged muscle fibers during the cascade of muscle healing and regeneration in vivo. The identities of these two myogenic factors are under study.
Two-dimensional electrophoresis was used to generate the aqueous protein expression patterns of rat extensor digitorum longus muscle (EDL, fast twitch muscle) and solues muscle (SOL, slow twitch muscle) of different ages. Two specific protein spots, S1 and S3, were identified from EDL muscles at the ages of 12 and 18 months onward respectively. In the EDL muscles of aged rat (24 months) after intensive exercise training, S3 was still detected while S1 disappeared. In addition, diaphragm muscle (DIA, fast twitch muscle), which retains physically active throughout the life span, was used as nondisuse control. The results showed that the expressions of S1 and S3 in 24-month DIA muscle were identical with the trained aged EDL muscle. It is suggested that exercise might delay the onset of S1 expression. However, the expression of S3 over age seemed to be progressive and exercise independent. Another protein spot, S2 was identified to express only in young EDL and SOL muscles, but its expression decreased over age. Furthermore, exercise has no effect on S2 expression since S2 could not be detected in aged DIA as well as trained aged EDL and SOL muscles. These results indicated that aqueous protein expression patterns of skeletal muscle undergo changes during aging. Some of these changes such as S2 and S3 appear progressively, and some such as S1 could be delayed by exercise. S3 was identified as ubiquitin, which might play an important role in protein degradation during skeletal muscle aging process.
Fibrolamellar hepatocellular carcinoma (FL HCC) is an uncommon variant of hepatocellular carcinoma occurring usually in non-cirrhotic livers. Hepatic resection or transplantation offers the only chance of cure. We reviewed our experience of surgery for FL HCC from 1985-1998. Twenty patients with FL HCC (13 females and 7 males) median age 27 years (range 12-69) were treated either by hepatic resection [n = 11; extended right hepatectomy (5), extended left hepatectomy (1), right hemihepatectomy (2), left hemihepatectomy (2), left lateral segmentectomy (1)] or, if the disease was non-resectable, by transplantation (n = 9). The median follow up was 25 months (1-63). The prognostic factors analysed included size [less than 5 cm (3 patients), more than 5 cm (17 patients)], number [solitary (16 patients), multiple (4 patients)], capsular invasion (6 patients), vascular invasion (11 patients) and lymph node invasion (6 patients). The overall survival at 1, 3 and 5 years was 89.5, 75 and 50%, respectively. The liver resection survival was better than liver transplantation survival at 3 years 100 vs 76%, respectively (P < 0.025). Although all prognostic factors analysed did not show a significant difference, there is tendency that tumour stage was the most significant for prognosis. Most of the patients in this study are young and presented without specific symptoms, with normal liver function range and had no tumour marker to help in diagnosis. As a result most of our patients were diagnosed late. However the outcome of surgical intervention was favourable.
OBJECTIVE: To characterize the distribution of maternal weight gain in Chinese women living in a well-nourished community, to recommend target weight gains from quartile values derived from women with good pregnancy outcomes, and to quantify the risk for adverse pregnancy outcomes encountered among subjects with weight gain outside these recommendations. DESIGN: A retrospective study on maternal anthropometry and pregnancy outcomes was conducted among Chinese women who delivered a singleton pregnancy in a university hospital in Hong Kong. SUBJECTS: Nine hundred eight women who delivered during the study period were identified. Among them, 754 (83%) had complete anthropometry data. The normative distribution of maternal weight gain was derived from 504 women who had a good pregnancy outcome. STATISTICS: Analysis of variance was used to compare total weight gain among women of different prepregnancy weight. Fisher exact test was used in the univariate analysis of the association between risk factors and corresponding adverse pregnancy outcomes. Adjusted odds ratios for adverse outcomes were determined by multiple logistic regression models controlling for the following factors: maternal age, duration of gestation, prepregnancy body mass index (BMI), height, parity, and smoking. RESULTS: A maternal weight-gain chart and recommendations for total weight gains in Chinese women were derived from the distribution of weight gain in subjects with good pregnancy outcomes. The recommended total weight gain was 13 to 16.7 kg, 11 to 16.4 kg, and 7.1 to 14.4 kg respectively for women of low (BMI < 19), moderate (BMI: 19 to 23.5), and high (BMI > 23.5) prepregnancy BMI. Women who did not achieve the lower quartile value had more than twice the risk of having low-birth-weight infants. Those with excessive weight gain were at risk for needing assisted delivery. APPLICATIONS: As maternal anthropometry differs across ethnic groups, different recommendations should be made for specific populations.
Single-nucleotide polymorphisms (SNPs) have been explored as a high-resolution marker set for accelerating the mapping of disease genes. Here we report 48,196 candidate SNPs detected by statistical analysis of human expressed sequence tags (ESTs), associated primarily with coding regions of genes. We used Bayesian inference to weigh evidence for true polymorphism versus sequencing error, misalignment or ambiguity, misclustering or chimaeric EST sequences, assessing data such as raw chromatogram height, sharpness, overlap and spacing, sequencing error rates, context-sensitivity and cDNA library origin. Three separate validations-comparison with 54 genes screened for SNPs independently, verification of HLA-A polymorphisms and restriction fragment length polymorphism (RFLP) testing-verified 70%, 89% and 71% of our predicted SNPs, respectively. Our method detects tenfold more true HLA-A SNPs than previous analyses of the EST data. We found SNPs in a large fraction of known disease genes, including some disease-causing mutations (for example, the HbS sickle-cell mutation). Our comprehensive analysis of human coding region polymorphism provides a public resource for mapping of disease genes (available at http://www.bioinformatics.ucla.edu/snp).
BACKGROUND: Near patient tests for Helicobacter pylori were developed to assist in the management of dyspepsia patients in general practice. Most studies were performed in western populations. AIM: To evaluate the rapid whole blood test (Flexpack HP) for H. pylori in the Chinese population. METHODS: Consecutive dyspeptic patients referred for upper endoscopy were recruited. During upper endoscopy, biopsies were taken from the antrum and corpus for rapid urease test (CLO test) and histological examination. After endoscopy, the whole blood test (FlexPack HP) was performed according to the manufacturer's instruction. Patients then received a 13C-urea breath test. Results of the whole blood test were compared with the gold standard (CLO test, histology and 13C-urea breath test). RESULTS: A total of 294 consecutive patients gave a valid Flexpack HP result for interpretation. The mean age of patients was 47.7 (range 15-85) years. Analysis showed a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 58%, 92%, 91%, 63% and 73% respectively. CONCLUSION: The FlexPack HP whole blood test showed good specificity but lacked sensitivity. It is not sensitive enough to be used in a general practice setting for the test-and-treat approach in the Chinese population.
Two rare cases of isolated central nervous system (CNS) candidiasis in preterm infants have been diagnosed in a tertiary neonatal centre over the past 6 years. Despite the life-threatening nature of the disease, biochemical infection markers were not useful for the early identification of localized fungal infection. Because the infection was likely to have been blood borne, we postulated that the initial fungal load was probably low and that the organisms were rapidly eliminated from the circulation after a few had been deposited in the CNS. Hence, the absence of fungaemia or systemic involvement precluded the activation of cytokines and cellular markers. Clinicians should be aware of the limitation of biochemical infection markers so that diagnosis and treatment of fungal infection will not be delayed.
Tumor necrosis factor (TNF) is widely accepted to be the mediator of the cascade of metabolic abnormalities associated with both critical and chronic illness. TNF binding to cell surface receptors mediates its physiologic actions, although the exact mechanism of TNF action is unknown. Therefore, this study was designed to investigate the in vivo metabolism of TNF using a mathematical model to examine tissue uptake and loss of TNF over time. Two distinct patterns of TNF uptake were observed. Muscle tissues were found to accumulate TNF over the entire experimental period, whereas the visceral organs were found to have a rapid initial accumulation of TNF followed by a rapid loss of TNF back to the plasma or out into the bile or the urine. These patterns of TNF binding and retention may reflect the number of TNF receptors or their affinity for TNF, as well as the balance between cell surface and soluble TNF receptors. Furthermore, TNF binding patterns provide insight into the biologic action of TNF at these sites.
OBJECTIVE AND IMPORTANCE: We describe the case of a patient in whom a snare designed for the removal of foreign bodies was successfully used to retrieve a thromboembolism from the middle cerebral artery. This technique can be used to reestablish blood flow when maximal pharmacological therapies have failed. CLINICAL PRESENTATION: A 38-year-old man with scrotal squamous cell carcinoma presented with the abrupt onset of left hemiparesis and numbness. Computed tomography of the head showed no hemorrhage or hypodensity, and right middle cerebral artery thrombosis was suspected. INTERVENTION: Cerebral angiography demonstrated a near-total occlusion of the right middle cerebral artery at the M1-M2 junction. The administration of intra-arterial urokinase, systemic heparin, and systemic abciximab, and mechanical maceration failed to lyse the clot. A 4-mm goose-neck snare was guided through a microcatheter, and the clot was snared and withdrawn. Immediate postoperative angiography demonstrated the reconstitution of normal flow. Pathological examination of the snared material was consistent with clot. By postoperative Day 5, the patient had regained full strength, except for the fingers of the left hand, which remained moderately weak. Computed tomography demonstrated a right insular and extreme capsular infarct. CONCLUSION: To our knowledge, this is the first reported use of a snare to remove clot in the setting of thromboembolic stroke. As the use of intra-arterial thrombolysis increases, transcatheter snare removal of pharmacologically resistant clot may be considered as a salvage strategy.
Treating patients with brain arteriovenous malformations by the deposition of liquid embolic agents, particularly cyanoacrylates, requires judgment, technical expertise, and experience. Even though the first deposition of cyanoacrylate in human brain arteries occurred more than 25 years ago, the relative rarity of the disease and the high risk for complications has kept this procedure from being universally applied. Physicians are fortunate that, within the past year, new and better catheters have become available, and with the promise of approved cyanoacrylate devices that are now being evaluated, the future looks bright. This article reviews the history, chemistry, and uses of cyanoacrylate.