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Biomedical subjects

Kenneth K Y Wong

Publications and source records attributed to Kenneth K Y Wong.

8 recordsLinked to original sources

Topical delivery of silver nanoparticles promotes wound healing.

Wound healing is a complex process and has been the subject of intense research for a long time. The recent emergence of nanotechnology has provided a new therapeutic modality in silver nanoparticles for use in burn wounds. Nonetheless, the beneficial effects of silver nanoparticles on wound healing remain unknown. We investigated the wound-healing properties of silver nanoparticles in an animal model and found that rapid healing and improved cosmetic appearance occur in a dose-dependent manner. Furthermore, through quantitative PCR, immunohistochemistry, and proteomic studies, we showed that silver nanoparticles exert positive effects through their antimicrobial properties, reduction in wound inflammation, and modulation of fibrogenic cytokines. These results have given insight into the actions of silver and have provided a novel therapeutic direction for wound treatment in clinical practice.

Administration, Topical↗

Continuous dynamic spinal motion analysis.

STUDY DESIGN: Continuous dynamic lumbar intervertebral flexion-extension is assessed by a videofluoroscopy with a new auto-tracking system. OBJECTIVES: To develop and validate a new method for the continuous assessment of lumbar kinematics. SUMMARY OF BACKGROUND DATA: Instability of the lumbar spine is thought to be associated with low back pain, but the diagnosis remains difficult. Functional radiographs have been used for diagnosis of spinal instability but error and limitation exist, whereas videofluoroscopy provides a cost-effective way for such analysis. However, common approaches of image analysis of videofluoroscopic video are tedious and time-consuming because of the low quality of the images. Physicians have to extract the vertebrae manually in most cases; thus, continuous motion analysis is hardly achieved. METHODS: A new system that can perform automatic vertebrae segmentation and tracking is developed. In vitro and in vivo validity were evaluated. Intervertebral flexion and extension was assessed in 30 healthy volunteers. RESULTS: In vitro and in vivo validity tests have been conducted with good results. A linear-liked pattern of the intervertebral flexion-extension (IVFE) curves in different levels was found, and the IVFE decreased in descending order from L1-L5 at different points of range of motion in flexion. Conversely, extension is evenly contributed at different levels, and the concavity of lumbar lordosis increases steadily in backward movement. CONCLUSIONS: The newly developed technique in assessing the dynamic lumbar motion is reliable and able to analyze the lumbar intervertebral movement from videofluoroscopic images automatically and accurately. The proposed system requires less human intervention than common approaches. It may have a potential value in the evaluation of spinal "instability" in clinical practice.

Adult↗

Trends in the prevalence of Helicobacter pylori in symptomatic children in the era of eradication.

PURPOSE: Helicobacter pylori infection is common in Asia and is associated with dyspepsia, peptic ulcer, and gastric cancer. Eradication of the organism remains an important goal. Here, we looked at the trends in the prevalence of H pylori in symptomatic children over an 8-year period to assess the impact of an aggressive eradication program. METHOD: A retrospective review was carried out between 1997 and 2004. All children with a history of dyspepsia or acute gastrointestinal bleeding were included and underwent gastroscopy. Three antral biopsies were taken during endoscopy and sent for histological analysis. Positivity of H pylori was treated aggressively with quadruple therapy under protocol. The demographic data, the histological findings, and the H pylori status were recorded. RESULTS: There were a total of 159 patients (71 males, 88 females) who underwent gastroscopy in this period. One hundred nineteen patients showed histological evidence of gastritis, and the positive rate of H pylori was 25.6%. The overall prevalence has not decreased (33.3% in 1997, 27.7% in 2004). Increasing age, however, was associated significantly with the higher risk of H pylori infection. CONCLUSION: H pylori has a high prevalence in Chinese children with increasing age. Eradication efforts seem to be unsuccessful in the reduction of prevalence. We hypothesize that this may be owing to cross-infection at meal times from sharing chopsticks.

Adolescent↗

Effective antibiotic regime for postoperative acute cholangitis in biliary atresia--an evolving scene.

PURPOSE: The prompt use of empirical antibiotics is vital in managing post-Kasai cholangitis. The authors published findings of their clinical trial in 1991 and established the use of cefoperazone, with a response rate of 88.9%. Here its clinical use since its introduction is reviewed and the trend in its efficacy is assessed. METHODS: A retrospective review was carried out between 1997 and 2003. All episodes of acute cholangitis in patients who underwent Kasai procedure were recorded. Cholangitis was defined as unexplained fever with derangement of liver enzymes. Cefoperazone was started empirically according to the established protocol, and the response to treatment was analyzed. RESULTS: There were 19 patients with a total of 49 episodes of cholangitis. Cefoperazone was used as the first-line empirical antibiotic in 40 of these episodes. Only 30 showed successful response (75%). For the 10 unresponsive episodes, meropenem was used as second-line antibiotic with complete response in all. CONCLUSIONS: The efficacy of cefoperazone in the treatment of post-Kasai cholangitis has decreased over the last years. This suggests a need for a more effective first-line empirical antibiotic. From this review, meropenem seems to be a suitable candidate, and a future prospective clinical trial is warranted.

Acute Disease↗

The use of positron emission tomography in detecting hepatoblastoma recurrence--a cautionary tale.

PURPOSE: The use of positron emission tomography (PET) with [18F] fluorodeoxyglucose (FDG) in the detection of recurrences has been well established in many tumor types. Here the authors present their experience using this modality in the evaluation of posttreatment hepatoblastoma patients. METHODS: The authors conducted a retrospective review on patients with hepatoblastoma diagnosed from 1996 to 2003. FDG-PET imaging was performed together with measurement of alpha-fetal protein (AFP) during posttreatment follow-up. RESULTS: Sixteen patients (8 boys and 8 girls) were identified in this series. The mean age was 23.5 months (range, 5 months to 4 years). Three posttreatment patients had PET results suggestive of tumor recurrence. One of these patients had normal AFP level and suspected recurrence in the caudate lobe. Radiologic-guided biopsy was performed 3 times, and there was no evidence of tumor. The other 2 patients underwent further liver resections because of mildly raised AFP levels. The histology of these showed regenerative liver tissue only with no hepatoblastoma recurrence. CONCLUSIONS: Although PET has been gaining popularity as a tool in the detection of tumor recurrences worldwide, it has been shown in this series that PET may not be useful in hepatoblastoma patients, and caution must be taken in the interpretation of positive results.

Child, Preschool↗

Mucous fistula refeeding in premature neonates with enterostomies.

BACKGROUND: Premature neonates with short bowel syndrome often have diverting enterostomies and distal mucous fistulae. The authors reviewed their experience in 12 premature neonates in whom proximal bowel contents were re-fed into the mucous fistula. METHODS: We reviewed the records of 12 premature neonates who presented with acute abdomen and who underwent intestinal resection with formation of diverting enterostomy and mucous fistula between July 1999 and December 2002. All received parenteral nutrition. Refeeding of enterostomy contents into the distal mucous fistula was commenced after patency of the distal intestine was confirmed by radiologic examination. Demographic data, body weight and clinical outcomes were recorded. RESULTS: Median gestational age was 31 weeks and mean birth weight was 1.59 kg. Diagnoses included necrotizing enterocolitis (n = 6), meconium ileus-like conditions (n = 2), ileal atresia (n = 2), malrotation with volvulus (n = 1) and focal intestinal perforation (n = 1). Refeeding was successfully established in all patients with no complications. The mean duration of refeeding was 63.5 days. All patients achieved good weight gain after refeeding (18.9 +/- 2.9 g/d) with a reduction of parenteral nutrition requirements. All enterostomies were subsequently closed. Four patients died of unrelated causes after reanastomosis and the remaining eight were discharged. CONCLUSIONS: Mucous fistula refeeding is safe in premature neonates with enterostomies. It can prevent disuse atrophy in the distal loop and facilitate subsequent reanastomosis. Furthermore, the increased absorptive function provided by the small bowel incorporated in the mucous fistula can reduce the requirement for total parenteral nutrition.

Enterostomy↗