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Biomedical subjects

J Goh

Publications and source records attributed to J Goh.

At least 19 recordsLinked to original sources
PubMed2006

Mechanical properties of articular cartilage covered by the meniscus.

OBJECTIVE: To investigate the mechanical properties and morphological characteristics of articular cartilage on the tibial plateau of human knees, including the region covered by the meniscus. DESIGN: Using a 1-mm diameter flat-ended cylindrical probe to apply a constant load (0.6 MPa) at specific sites on the tibial plateau, the mechanical properties of articular cartilage were studied using seven cadaver knees. Comparison was made between data obtained by the cartilage covered by the meniscus and that not covered. This was done for both the medial and lateral plateaus. Histological sections of the articular cartilage were also performed to study differences between cartilage from these regions of the tibial plateau. RESULTS: Compared to cartilage that was not covered by the meniscus, the articular cartilage beneath the meniscus showed a significantly (P<0.05) larger modulus by as much as 70%, and was less thick by about 40%. Also, the subchondral bone quantity and calcified layer thickness were observed to be significantly lesser in the regions covered by the meniscus. CONCLUSIONS: Our findings revealed a significant difference between the mechanical properties and associated structures of articular cartilage in the region covered by the meniscus compared with the articular cartilage not covered by the meniscus.

Aged↗
PubMed2006

The outcome of surgery in fulminant Clostridium difficile colitis.

BACKGROUND: The clinical presentation of Clostridium difficile infection ranges from asymptomatic carriage, colitis with or without pseudomembranes, to fulminant colitis. Although not common, fulminant C. difficile colitis can result in bowel perforation and peritonitis with a high mortality rate. Colectomy is often indicated in these cases. METHODS: We retrospectively analysed the outcome of 14 patients who underwent surgery for fulminant C. difficile colitis in the period 1996-2003 in our Unit. RESULTS: The indications for surgery were systemic toxicity and peritonitis (n = 10), radiological and clinical evidence of progressive toxic colonic dilatation (n = 3) and progressive colonic dilatation with bowel perforation (n = 1). C. difficile infection as the cause of colitis was diagnosed pre-operatively in seven (50%) patients, six of whom underwent a total colectomy and one a right hemicolectomy. Overall mortality in our series was 35.7%. Total colectomy was associated with a lower mortality rate of 11.1% (1/9) when compared with left hemicolectomy was 100% (4/4) (P = 0.01). One patient who underwent a right hemicolectomy (on the basis of deceptively normal external appearance of the rest of the colon intra-operatively) survived after a prolonged hospital stay. CONCLUSIONS: Early or pre-operative microbiological diagnosis of C. difficile infection can be difficult in patients with a fulminant presentation. Those patients with C. difficile colitis, who develop signs of toxicity, peritonitis or perforation, should undergo a total colectomy as the operation of choice.

Adult↗
PubMed2006

Endolymphatic sac tumour: a rare cause of recurrent vertigo.

Endolymphatic sac tumour occurring in a 32-year-old man presenting with Meniere's like symptoms of recurrent vertigo, hearing loss and tinnitus is described. Magnetic resonance imaging and computed tomography showed a vascular bone tumour centred over the retrolabyrinthine aspect of the temporal bone where the endolymphatic sac was located. Surgical excision via a translabyrinthine approach was performed. Endolymphatic sac tumours are rare papillary adenocarcinomas that arise from the endolympatic sac. It can be mistaken both on radiology and histology for other tumours such as paragangliomas, renal or papillary thyroid carcinoma metastases. Surgical excision is the treatment of choice but sacrifice of the auditory and facial nerve may be needed in advanced cases to achieve tumour clearance.

Adenocarcinoma, Papillary↗
PubMed2006

Clinics in diagnostic imaging (111): X-linked congenital mixed deafness syndrome.

Two siblings, boys aged five and six years old, presented with mixed hearing loss. Computed tomography of the temporal bones showed bulbous dilatation of the internal auditory canals and incomplete separation with the basal turn of the cochlear, consistent with the diagnosis of X-linked congenital progressive mixed deafness syndrome. The diagnosis and management of this rare condition is discussed.

Child↗
PubMed2003

Direct repair vs. overlapping sphincter repair: a randomized, controlled trial.

PURPOSE: The aim of this study was to compare the results of two surgical techniques (direct end-to-end vs. overlapping) of delayed repair of a localized anterior defect of external anal sphincter after an obstetric trauma. METHODS: During a five-year period, 23 patients were randomly assigned to direct end-to-end repair (n = 12) or overlapping sphincter repair (n = 11), using 2-0 PDS sutures. Two patients from each group had an internal anal sphincter defect that also was repaired. All patients had a normal pudendal nerve terminal motor latency preoperatively. Evaluations included endoanal ultrasound, anorectal manometry, and neurophysiologic evaluation. Continence was assessed by the Cleveland Clinic Continence Score (0-20; 0, perfect continence; 20, complete incontinence). RESULTS: The two groups were comparable with regard to age (median, 45 years), past history of sphincter repair (n = 2), and posterior vaginal repair. There was no major morbidity. The wound-healing rate was identical between the two groups. However, of the patients undergoing overlapping repair, two had fecal impaction, and one had a urinary retention. Median preoperative continence score was 17 in both the direct-repair group (score, 8-20) and the overlap group (score, 7-20). At a median follow-up of 18 months, the improvement in continence was similar between the two surgical groups, with a median continence score of 3, respectively. In both surgical groups there was a significant and similar improvement in maximum squeeze pressure and in the functional anal canal length postoperatively (P < 0.05), but the mean resting pressure was relatively unchanged. In the overlap group, one patient developed a unilaterally prolonged pudendal nerve terminal motor latency that was persistent 22 months after surgery, and two patients had impaired fecal evacuation postoperatively. CONCLUSIONS: This randomized, controlled study suggests that the outcome is similar whether direct end-to-end or overlapping repair of a sphincter defect is performed. Overlapping repair might be associated with more difficulties with fecal evacuation and a prolonged pudendal nerve terminal motor latency postoperatively.

Adult↗
PubMed2003

Review article: nutrition and adult inflammatory bowel disease.

Major advances in the understanding of the aetio-pathogenesis and genetics of inflammatory bowel disease have been accompanied by an escalation in the sophistication of immunomodulatory inflammatory bowel disease therapeutics. However, the basic 'triple' therapy (5-aminosalicylates, corticosteroids, azathioprine) and nutrition have maintained their central role in the management of patients with inflammatory bowel disease over recent decades. This review provides an overview of the supportive and therapeutic perspectives of nutrition in adult inflammatory bowel disease. The objective of supportive nutrition is to correct malnutrition in terms of calorie intake or specific macro- or micronutrients. Of particular clinical relevance is deficiency in calcium, vitamin D, folate, vitamin B12 and zinc. There is justifiably a growing sense of unease amongst clinicians and patients with regard to the long-term use of corticosteroids in inflammatory bowel disease. This, rather than arguments about efficacy, should be the catalyst for revisiting the use of enteral nutrition as primary treatment in Crohn's disease. Treatment failure is usually related to a failure to comply with enteral nutrition. Potential factors that militate against successful completion of enteral nutrition are feed palatability, inability to stay on a solid-free diet for weeks, social inconvenience and transient feed-related adverse reactions. Actions that can be taken to improve treatment outcome include the provision of good support from dietitians and clinicians for the duration of treatment and the subsequent 'weaning' period. There is evidence to support a gradual return to a normal diet through exclusion-re-introduction or other dietary regimen following the completion of enteral nutrition to increase remission rates. We also review the evidence for emerging therapies, such as glutamine, growth factors and short-chain fatty acids. The future may see the evolution of enteral nutrition into an important therapeutic strategy, and the design of a 'Crohn's disease-specific formulation' that is individually tailored, acceptable to patients, cost-effective, free from adverse side-effects and combines enteral nutrition with novel pre- and pro-biotics and other factors.

Butyrates↗
PubMed2003

Early neoplasias of the gallbladder and bile duct: an "unstable" biliary epithelium?

Benign tumours of the biliary tree are rare. In particular, only anecdotal cases of intraductal villous adenomas have been reported. The polyp-cancer sequence has not been observed in the biliary epithelium, in contrast to the paradigm of colorectal carcinogenesis. This report presents the case of a 64-year-old woman with a past history of cholelithiasis who had two early neoplasias involving the biliary epithelium: an adenocarcinoma in situ of the gallbladder and a common bile duct (CBD) villous adenoma with high-grade dysplasia. The tumours presented 4 years apart. The clinical features and combined radiological, cytological, and surgical modalities leading to the diagnosis of intraductal villous adenoma are presented. The endoscopic ultrasound (EUS) characteristics of villous adenoma of the CBD are described. While the prognosis on both occasions appears excellent following curative resections of both tumours detected at an early stage, it is possible that further neoplasia involving the biliary tree may recur. There are currently no data on optimal surveillance modalities. It may be hypothesized that the gallbladder and biliary epithelium share a similar mechanism for carcinogenesis to that observed in the colonic adenomacarcinoma sequence.

Adenoma, Villous↗
PubMed2001

Lipoxin A(4) and aspirin-triggered 15-epi-lipoxin A(4) antagonize TNF-alpha-stimulated neutrophil-enterocyte interactions in vitro and attenuate TNF-alpha-induced chemokine release and colonocyte apoptosis in human intestinal mucosa ex vivo.

Lipoxins (LXs) are lipoxygenase-derived eicosanoids and putative endogenous braking signals for inflammation in the gastrointestinal tract and other organs. Aspirin triggers the production of 15-epimers during cell-cell interaction in a cytokine-primed milieu, and aspirin-triggered 15-epi-5(S),6(R),15(S)-trihydroxy-7,9,13-trans-11-cis-eicosatetraenoic acid (15-epi-LXA(4)) may contribute to the bioactivity profile of this prototype nonsteroidal anti-inflammatory drug in vivo. We determined the effect of LXA(4), 15-(R/S)-methyl-11,12-dehydro-LXA(4) methyl ester (15-(R/S)-methyl-LXA(4)), and stable analogs of LXA(4) on TNF-alpha-stimulated neutrophil-enterocyte interaction in vitro and TNF-alpha-stimulated chemokine release, changes in mucosal architecture, and enterocyte apoptosis in cytokine-activated intact human colonic mucosa ex vivo. LXA(4), 15-(R/S)-epi-LXA(4), and 16-phenoxy-11,12-dehydro-17,18,19,20-tetranor-LXA(4) methyl ester (16-phenoxy-LXA(4)) inhibited TNF-alpha-stimulated neutrophil adherence to epithelial monolayers at nanomolar concentrations. In parallel experiments involving human colonic mucosa ex vivo, LXA(4)potently attenuated TNF-alpha-stimulated release of the C-X-C chemokine IL-8, and the C-C chemokines monocyte-chemoattractant protein-1 (MCP-1) and RANTES. Exposure of strips of normal human colonic mucosa to TNF-alpha induced disruption of mucosa architecture and enhanced colonocyte apoptosis via a caspase-3-independent mechanism. Prior exposure of the mucosa strips to 15-(R/S)-methyl-LXA(4) attenuated TNF-alpha-stimulated colonocyte apoptosis and protected the mucosa against TNF-alpha-induced mucosal damage. In aggregate, our data demonstrate that lipoxins and aspirin-triggered 15-epi-LXA(4) are potent antagonists of TNF-alpha-mediated neutrophil-enterocyte interactions in vitro, attenuate TNF-alpha-triggered chemokine release and colonocyte apoptosis, and are protective against TNF-alpha-induced morphological disruption in human colonic strips ex vivo. Our observations further expand the anti-inflammatory profile of these lipoxygenase-derived eicosanoids and suggest new therapeutic approaches for the treatment of inflammatory bowel disease.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

Increased urinary nitrite, a marker of nitric oxide, in active inflammatory bowel disease.

BACKGROUND: Nitric oxide (NO) production is increased in inflammatory bowel disease (IBD), and measurement of NO metabolites may be useful for monitoring disease activity. AIMS AND OBJECTIVES: To characterise urinary nitrite levels, a stable metabolite of NO, in IBD and to evaluate its potential as a marker of disease activity. METHODS: Twelve-hour urinary nitrites were measured by the microplate assay method in 46 patients with IBD (active; n = 32). Urinary samples from 16 healthy individuals served as controls. RESULTS: Increased levels of urinary nitrites were found in patients with active IBD compared with those with inactive IBD. Twenty-eight out of 32 patients (87.5%) with active IBD had detectable levels of nitrite in their urine as compared with 2/14 (14.3%) patients with inactive IBD. None of the 16 healthy controls had detectable urinary nitrite. Twelve-hour urinary nitrite in active compared with inactive IBD: 5 0.7 versus 0.1+/-0.04 micromol (P < 0.05). There was good correlation between urinary nitrite and some markers of disease activity in IBD such as C-reactive protein and microalbuminuria but not with erythrocyte sedimentation rate. CONCLUSIONS: Increased levels of nitrite were detected in urine of patients with active IBD, consistent with increased NO synthesis. This simple assay may be exploited as a potential marker of disease activity in IBD.

Albuminuria↗
PubMed2001

Aggressive multiple myeloma presenting as mesenteric panniculitis.

Mesenteric panniculitis is a rare disease of the bowel mesentery, characterized by tumor-like infiltration by chronic inflammatory cells, fat necrosis, and fibrosis. Reported cases cited clinical presentation ranging from abdominal pain to fever of unknown origin, the majority of which were idiopathic and associated with a benign prognosis. We report the case of a 43-yr-old male who presented with malaise, weight loss, microcytic anemia, and a high erythrocyte sedimentation rate. Radiographic and histological investigations revealed typical features of mesenteric panniculitis. Initial treatment with high-dose oral prednisolone led to rapid and complete resolution of symptomatology, radiographic, and laboratory anomalies. Within 6 months, the patient presented again with anemia, renal failure, and hypercalcemia. A diagnosis of IgA kappa chain myeloma was made. Despite chemotherapy and restoration of normocalcemia, he died from refractory pulmonary edema. This is the first report of a hematological malignancy initially presenting with features of mesenteric panniculitis culminating in an aggressive course and a fatal outcome.

Adult↗
PubMed2001

The natural course of hepatitis C virus infection after 22 years in a unique homogenous cohort: spontaneous viral clearance and chronic HCV infection.

BACKGROUND/AIMS: The cohort of Irish women infected with hepatitis C virus (HCV) genotype 1b via contaminated anti-D immunoglobulin in 1977 represent a unique homogenous group to investigate the natural course of HCV infection. METHODS: The clinical status of 87 polymerase chain reaction (PCR) positive and 68 PCR negative women was investigated at diagnosis (1994/95) and after 4-5 years of follow up (21/22 years after inoculation). Other features investigated included: histological status/progression, psychosocial impact of HCV infection, extrahepatic manifestations, and HLA class II associations. RESULTS: The most common symptoms reported were fatigue and arthralgia. Furthermore, 77% of women fell within the clinical range for psychological distress. A history of icteric hepatitis was reported in 20.6% of PCR negative and 3.4% of PCR positive women after inoculation (p=0.002). The mean histological activity index/fibrosis scores of PCR positive and negative women were 4.1 (1.4)/1.1 (1.3) and 2.1 (1.5)/0.15 (0.36) at diagnosis and 4.1 (1.2)/1.0 (1.0) in 44 PCR positive women after five years of follow up. Cirrhosis or hepatocellular carcinoma was not observed. The DRB1*01 allele was present in 28.8% of PCR negative and 8.7% of PCR positive women (p=0.004). The prevalence rates of mixed cryoglobulinaemia, sicca complex, positive thyroid autoantibodies, antinuclear antibody, rheumatoid factor, and antimitochondrial antibody in PCR positive women were 12.7%, 7.6%, 13.9%, 5.1%, 3.8%, and 3.8%. CONCLUSIONS: A benign course of HCV infection with lack of disease progression was observed in women with chronic HCV, 22 years after inoculation. Acute icteric hepatitis and the HLA DRB1*01 allele were associated with viral clearance. Despite this favourable outcome, high levels of psychological distress and poor quality of life were present.

Alanine Transaminase↗
PubMed2001

Severe juvenile chronic constipation.

Constipation in the paediatric population is common and encompasses a spectrum of organic and functional pathology which differ from that of the adult population. Recently an expert group published a comprehensive system of classification of childhood functional gastrointestinal disorders that may have useful clinical application. We present the case of an adolescent schoolgirl with severe constipation with extreme anorectal, urological and neurological sequelae who displayed inappropriate behavioral response to her condition. The patient appeared inappropriately unmotivated and undisturbed by the severity of her constipation. This abnormal psychological habituation and adaptation to an abnormal bowel habit perpetuated the constipation. In addition, we examined the role of recent advances in anorectal investigation techniques and treatment in the context of the recent guidelines issued by the American Gastroenterological Association

Adolescent↗
PubMed2001

Nature of codes extracted during the attentional blink.

This set of 6 experiments used a 2-target rapid serial visual presentation paradigm to address 2 main questions: (a) What is the nature of the code retrieved from nontarget (i.e., unselected) items? and (b) How do the processing demands of the target affect the nature of the codes extracted from its proximate distractors? There were 3 main results: First, unless a nontarget receives attentional processing, its codes remain dormant. The type of activated codes depends on the perceptual load imposed by the other items that also underwent processing. Second, the item trailing the target invariably gets processed, but those farther downstream are excluded. If target selection is exacting, the codes of the item leading the target may also be enhanced. Third, the magnitude of the attentional blink increases with target selection difficulty; it is, however, unaffected by the perceptual load imposed by the target.

Attention↗
PubMed1999

Fatigue does not correlate with the degree of hepatitis or the presence of autoimmune disorders in chronic hepatitis C infection.

BACKGROUND: Fatigue is probably the most commonly reported symptom in chronic hepatitis C virus (HCV) infection. It is unclear whether fatigue is related to the severity of underlying liver disease or other autoimmune disorders often described with chronic HCV infection. OBJECTIVE: To quantify fatigue in terms of its impact on quality of life in a homogeneous cohort and examine its relationship to the status of liver disease or associated autoimmunity. METHODS: The Fatigue Impact Scale (FIS) questionnaire (Fisk et al. Clin Infect Dis 1994; 18:S79-S83), a recently validated psychometric tool for assessing patients' perceptions of the functional limitations attributable to fatigue (40 statements; three subscales: physical, cognitive and psychological; maximum score = 160), was applied to a cohort of Irish women who were PCR-positive for HCV genotype 1b via inoculation with contaminated anti-D products in 1977. RIBA-positive, PCR-negative patients (n = 20) and healthy age-matched women (n = 50) served as controls. The degree of hepatitis was assessed using the Knodell histological activity index (HAI) score on previous liver biopsies. Clinical and laboratory evidence of cryoglobulinaemia, Sjogren's syndrome, connective tissue diseases, autoimmune thyroid disease and glomerulonephritis was sought. RESULTS: The mean FIS score of the 66 PCR-positive women (mean 78+/-36; range 7-153) was significantly higher than in age-matched controls (mean 31+/-24, range 0-78, P<0.001) but not statistically different from that of the RIBA-positive, PCR-negative group. The FIS score did not correlate with the HAI score (median HAI = 4; range 2-9; Pearson's correlation coefficient r=0.01, P=0.9). Significant levels of cryoglobulins were detected in 10 (15.2%). The sicca complex was diagnosed in six patients, three of whom had associated cryoglobulinaemia. Thyroid antibodies, anti-nuclear antibody, rheumatoid factor, antimitochondrial antibody and anti-smooth muscle antibody were detected in 15.2%, 6%, 4.5%, 4.5% and 1.5%, respectively. There was no significant difference in the FIS score between the groups with autoimmune diseases and those without. The FIS score of the nine patients previously treated with interferon was not statistically different from the untreated group (P=0.39). CONCLUSION: The perceived functional impact of fatigue on quality of life is significantly higher in patients with chronic HCV genotype 1b infection compared to healthy controls. However, it is unrelated to the degree of hepatitis and cannot be accounted for by the co-existence of autoimmune disorders alone.

Adult↗
PubMed1999

Hepatocellular carcinoma arising in the absence of cirrhosis in genetic haemochromatosis: three case reports and review of literature.

Genetic haemochromatosis constitutes a high risk factor for the development of hepatocellular carcinoma. It is widely accepted that venesection prevents the evolution of cirrhosis in haemochromatosis and indirectly protects against the development of hepatocellular carcinoma. Clinical, pathological and radiological data are presented on three patients who did not conform to the 'siderosis-cirrhosis-carcinoma' sequence and in whom prompt and adequate iron depletion did not prevent the development of cancer. This is the first report of hepatocellular carcinoma intervening in non-cirrhotic liver in two siblings with genetic haemochromatosis. The current literature on the subject is reviewed. The direct oncogenic role of iron remains to be elucidated. Hepatocellular carcinoma should be considered as a differential diagnosis in patients with non-cirrhotic genetic haemochromatosis who present with clinical deterioration during the course of an otherwise uneventful venesection programme.

Adult↗