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Biomedical subjects

R H Park

Publications and source records attributed to R H Park.

At least 19 recordsLinked to original sources
PubMed2001

Reproducibility of scanning laser polarimetry (GDx) of peripapillary retinal nerve fiber layer thickness in normal subjects.

PURPOSE: To assess the reproducibility of measurement of retinal nerve fiber layer (RNFL) thickness among subjects using the GDx Nerve Fiber Analyzer (NFA). METHODS: One eye of each of five young and healthy volunteers was imaged by three newly trained technicians (R.-H.P, K.-R.K., and S.-T.K.). Each volunteer was scanned six consecutive times for five independent times within a 1-month period. One composite image was selected out of three best images per session. Intra- and interoperator reproducibilities were calculated and the influence of placement of measurement ellipse by a single operator on interobserver reproducibility was also investigated. RESULTS: Mean coefficients of variation for total integral value of RNFL were 3.67 +/- 1.47%, 3.86 +/- 2.13%, and 4.16 +/- 1.97%, respectively for the three technicians. Interoperator variability was not statistically significant (P = 0.075), and the difference was even less if a single ellipse drawn by one operator was used in all measurements (P = 0.1528) by repeated-measures analysis of variance (ANOVA). CONCLUSIONS: The results suggest that GDx NFA may provide acceptable intraoperator as well as interoperator reproducibility among Asian eyes.

Adult↗
PubMed1996

Role of VLA-integrin receptor in invasion and metastasis of human fibrosarcoma cells.

Anti-invasive and anti-metastatic effects of anti-integrin antibodies (against VLA-alpha 2, alpha 4, beta 1) were examined on human fibrosarcoma cells using in vitro invasion assay in a reconstituted basement membrane (Matrigel) and experimental metastatic assay in a chick embryo. The effects of anti-integrin antibodies were compared with those of RGD-containing peptides (GRGDS), which have been known as effective inhibitors of tumor cell metastasis. Although slight differences in effective concentration among antibodies were observed, invasion and metastasis were significantly inhibited by anti-integrin antibodies. The results also showed partial inhibitory effect of GRGDS on the invasion and metastasis of human fibrosarcoma cells. These results indicate that integrin receptors mediating cell-cell/cell-extracellular matrix components interactions play a key role in the invasion and metastasis of human fibrosarcoma cells.

Animals↗
PubMed1996

Sucralfate suppresses Helicobacter pylori infection and reduces gastric acid secretion by 50% in patients with duodenal ulcer.

BACKGROUND & AIMS: The mechanism(s) by which sucralfate heals duodenal ulcers remains unclear. The aim of this study was to determine the effect of sucralfate on Helicobacter pylori infection and on the accompanying hypersecretion of gastric acid the infection induces in patients with duodenal ulcer. METHODS: Basal and gastrin-releasing peptide (GRP) stimulated gastrin release and acid secretion. H. pylori density, gastric urease activity, and severity of gastritis were studied in patients with duodenal ulcer who were positive for H. pylori before, during, and after 4 weeks' treatment with sucralfate (2 g twice daily). RESULTS: The density of H. pylori decreased by 70% during sucralfate treatment and returned to the pretreatment level after discontinuation of therapy. This suppression of H. pylori infection was accompanied by an 80% decrease in gastric urease activity. GRP-stimulated plasma gastrin concentrations, GRP-stimulated acid output, and basal acid output all decreased by approximately 50% during sucralfate therapy and returned to pretreatment levels after treatment was discontinued. CONCLUSIONS: These findings indicate that sucralfate markedly suppresses H. pylori infection and the accompanying hypersecretion of acid the infection induces in patients with duodenal ulcer. These effects are likely to be important mechanisms by which the drug promotes duodenal ulcer healing.

Adult↗
PubMed1996

Insulin-like growth factor-I in Helicobacter pylori gastritis and response to eradication using bismuth based triple therapy.

AIMS: To measure insulin-like growth factor-I (IGF-I) concentrations in the presence and absence of Helicobacter pylori infection and in response to eradication of the organism. METHODS: An enzyme linked immunosorbent assay was used to measure gastric and fasting serum concentrations of IGF-I in 17 patients with and 11 without H pylori infection. Repeat assessments were performed in the infected patients six weeks after they received a two week course of bismuth chelate, metronidazole, and amoxycillin. RESULTS: IGF-I was detected at very low concentrations in gastric juice and in mucosal incubates. The median serum IGF-I concentration was 88 micrograms/l in the patients infected with H pylori compared with 90 micrograms/l in the non-infected controls; IGF-I concentrations dropped to 77 micrograms/l following eradication therapy (p = 0.014). CONCLUSION: The similarity in baseline IGF-I concentrations in the presence and absence of H pylori suggests that their subsequent drop after treatment is more likely to be due to the treatment.

Adult↗
PubMed1996

Gastric mucosal hepatocyte growth factor in Helicobacter pylori gastritis and peptic ulcer disease.

OBJECTIVES: Hepatocyte growth factor (HGF) is increasingly recognized for its role in a variety of hepatic and systemic diseases. Its relationship to gastritis has not been studied. We aimed at measuring gastric mucosal HGF levels in the presence or absence of Helicobacter pylori gastritis, in peptic ulcers, and in response to H. pylori eradication. METHODS: Fifty one patients were studied. Patients were not entered if they had liver disease, malignancy, or any systemic illness. HGF was measured in gastric antral incubates using an enzyme-linked immunosorbent assay. Assessments were repeated 6 wk after a 2-wk course of anti-H. pylori triple therapy in 12 patients. Code numbers were used for blinding. RESULTS: The median gastric mucosal HGF level was 36 ng/gm/tissue in patients with H. pylori gastritis (n = 33) compared with 19 ng/gm in 18 negative controls (p = 0.0024), 18 ng/gm after the eradication of H. pylori (p = 0.021), 23 ng/gm in all patients with ulcers (n = 10), and 26 ng/gm/tissue in H. pylori-positive ulcers (n = 7). CONCLUSIONS: Gastric mucosal HGF levels were elevated in H. pylori gastritis and reduced by its eradication. These results are relevant to our understanding of the increased gastric cell proliferation in patients with H. pylori-related gastritis.

Adult↗
PubMed1996

Altered urinary interleukin-8/creatinine ratio in peptic ulcer disease: pathological and diagnostic implications.

OBJECTIVES AND METHODS: To assess its clinicopathological and diagnostic significance, interleukin-8 (IL-8) was measured by radioimmunoassay in fasting urine specimens and in gastric mucosal incubates taken from 54 patients with dyspepsia. The presence of Helicobacter pylori, the activity of gastritis, and urine creatinine levels were also assessed. RESULTS: The median urinary IL-8/creatinine ratio was 0.1 x 10(-6) in patients with current peptic ulcers (n = 13) and 0.2 x 10(-6) in patients with a history of ulcers (n = 8), compared with 0.4 x 10(-6) (p < 0.0001) in patients without ulcers who were infected with H. pylori (n = 20) or not infected (n = 13). The activity of gastritis had a positive correlation with gastric IL-8 (r = 0.5870, p < 0.01) and a negative correlation with urinary IL-8/creatinine ratio (r = -0.6447, p < 0.005). The improvement in the activity of gastritis in 20 patients given anti-H. pylori triple therapy was associated with a significant fall in gastric mucosal IL-8 and a rise in urinary IL-8/creatinine ratio. CONCLUSIONS: An inverse relationship seems to exist between urinary IL-8 and the activity of gastritis and gastric IL-8. This may represent another concept in the pathogenesis of peptic ulcers and can assist in the noninvasive diagnosis of peptic ulcer disease.

Adult↗
PubMed1995

Use of a stable copper isotope (65Cu) in the differential diagnosis of Wilson's disease.

1. 65Cu/63Cu stable-isotope ratios have been measured in blood serum after oral administration of the stable isotope 65Cu. The incorporation of the isotope into the plasma protein pool was followed at various times for up to 3 days. The resulting patterns of enrichment in healthy control subjects, in Wilson's disease patients and in heterozygotes for the Wilson's disease gene, were similar in appearance to those found by others using copper radioactive isotopes. After an initially high enrichment at 2 h after dosage, the Wilson's disease cases, in contrast to the control subjects, did not show a secondary rise in isotope enrichment of the plasma pool after 72 h, demonstrating a failure to incorporate copper into caeruloplasmin. The Wilson's disease heterozygotes had variable degrees of impairment of isotope incorporation, not always distinguished from those of control subjects. 2. The stability of the isotope also permits the copper tracer to be followed for a longer period. Ten healthy subjects were studied for over 40 days, allowing the biological half-time of an oral dose of copper to be determined (median 18.5 days, 95% confidence interval 14-26 days). Known heterozygotes for the Wilson's disease gene were found to have a significantly increased biological half-time for removal of copper from the plasma pool (median 43 days, 95% confidence interval 32-77 days). 3. The incorporation of 65 Cu in patients with diseases of the liver (other than Wilson's disease) was found to be similar to that in control subjects, aiding differential diagnosis.

Adolescent↗
PubMed1992

Randomised comparison of percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia.

OBJECTIVE: To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia. DESIGN: Randomised 28 day study of inpatients requiring long term enteral nutrition. SETTING: Three Glasgow teaching hospitals. SUBJECTS: 40 patients with dysphagia for at least four weeks secondary to neurological disorders: 20 patients (10 women) were randomised to nasogastric feeding and 20 (eight women) to endoscopic gastrostomy. MAIN OUTCOME MEASURES: Treatment failure (blocked or displaced tubes on three or more occasions or refusal to continue treatment); duration of feeding; intake of liquid diets; complications; nutritional status at end of trial. RESULTS: One patient in each group died before starting feeding. Treatment failure occurred in 18 of the 19 nasogastric patients and in none of the gastrostomy group. The mean (SE) duration of feeding for the nasogastric group was 5.2 (1.5) days. No complications occurred in the nasogastric group but three (16%) of the gastrostomy group developed minor problems (aspiration pneumonia (two patients) wound infection (one)). Gastrostomy patients received a significantly greater proportion of their prescribed feed (93% (2%)) compared with the nasogastric group, (55% (4%); p less than 0.001) and also gained significantly more weight after seven days of feeding (1.4 (0.5) kg v 0.6 (0.1) kg; p less than 0.05). Analyses at days 14, 21, and 28 were not possible due to the small numbers remaining in the nasogastric group. CONCLUSION: Percutaneous endoscopic gastrostomy tube feeding is a safe and effective method of providing long term enteral nutrition to patients with neurological dysphagia and offers important advantages over nasogastric tube feeding.

Aged↗
PubMed1992

DNA-based presymptomatic diagnosis of Wilson disease.

Investigation using DNA markers in a family with Wilson disease revealed that an apparently normal child of 10 years of age with non-diagnostic copper biochemistry had the disease. The procedure used linked restriction fragment length polymorphic markers. Demonstration of increased liver copper concentration from a liver biopsy confirmed the diagnosis and the child was started on chelation therapy. Two other asymptomatic siblings were shown, using the same techniques, not to have the disease. Similar analysis was carried out on another family with just one index case.

Chromosomes, Human, Pair 13↗
PubMed1992

Home sweet HEN--a guide to home enteral nutrition.

Initial experience of home enteral nutrition (HEN) was gained from malnourished patients with Crohn's disease. The rationale for HEN was to improve the patients' lifestyle by reducing the need for repeated admissions for nutritional support: this method is extremely useful in correcting nutritional problems. Over the past ten years the use of HEN has expanded to cover other clinical areas including correction of growth retardation secondary to gastrointestinal disease, cystic fibrosis, inborn errors of metabolism, congenital heart disease, and chronic renal failure, in addition to many types of neoplasia and chronic neurological diseases. At the present time, approximately 150 patients receive HEN within the catchment area of the Greater Glasgow Health Board (population 940,000). Despite the increasing availability of HEN many clinicians and dietitians are still reluctant to consider HEN as a 'routine adjunct' to clinical management, claiming that it is too dangerous or complicated. The aims of this article are to explain our method of running a HEN service, offer advice on practical problems and discuss further developments and potential difficulties.

Enteral Nutrition↗
PubMed1992

Percutaneous endoscopic gastrostomy tube feeding may improve outcome of late rehabilitation following stroke.

We describe three stroke patients with prolonged swallowing difficulty whose rehabilitation had been unsuccessful due to recurrent aspiration pneumonia and/or nasogastric tube dislodgement. Percutaneous endoscopic gastrostomy tube feeding, initiated 4-6 months following the onset of stroke, was associated with nutritional improvement, marked functional recovery and eventual discharge from hospital. This form of nutritional support may find an important role in the rehabilitation of stroke patients with persisting difficulty with swallowing.

Cerebrovascular Disorders↗
PubMed1992

Who should log SHIPS? The accuracy of Scottish Hospital Morbidity Data for Wilson's disease.

We have studied the accuracy of the hospital diagnostic data for Wilson's disease (WD) in Scotland. The computerised records of the Scottish Hospital In-Patient Statistics provided information on 41 patients, coded as having been discharged from hospital with a diagnosis of WD. Review of the patients' case notes revealed that 12 (29.6%) did not have WD, although half of these cases had 'query Wilson's disease' on the discharge summary or letter. In the other six cases, errors arose due to miscoding by the medical records staff.

Abstracting and Indexing↗
PubMed1991

Wilson's disease in Scotland.

The prevalence and clinical features of Wilson's disease in Scotland were investigated. Thirty three cases were identified but adequate information was available on only 28. In 1989, the prevalence rate was 4 per million. Ten patients with a mean (SEM) age of 18 (1.9) years presented with neurological symptoms, 12 patients aged 14 (1.7) years presented with hepatic symptoms, and six patients aged 12 (0.9) years were asymptomatic siblings of patients with Wilson's disease. Nine (56%) of the 16 patients who underwent liver biopsy on presentation were found to have cirrhosis. Penicillamine treatment was stopped in nine patients because of: abnormal peripheral blood count (6), rash (2), and patient's own choice (1). Nineteen patients were alive in 1989 -12 were well, one had chronic liver failure, four chronic neurological disabilities, and two had both chronic liver failure and neurological disabilities. Twelve patients died from: complications of chronic liver failure (2), acute liver failure (4), pneumonia associated with immobility (4), and other causes (2). Several patients who died had received incomplete medical supervision.

Adolescent↗
PubMed1990

Achalasia-like syndrome in systemic sclerosis.

Two methods of quantifying oesophageal emptying for liquids have been used to assess the dysphagia of patients with systemic sclerosis: the oesophageal infusion scintiscan and the timed Gastrografin swallow. Upper gastrointestinal endoscopy and oesophageal manometry were also performed. Thirteen patients with oesophageal symptoms were studied. Eight had dysphagia, and all of these had endoscopies with no evidence of oesophagitis or stricture. Four of these eight subjects had gross delay of oesophageal emptying for fluids, and manometry showed absence of oesophageal peristalsis and incomplete relaxation of the lower oesophageal sphincter. This abnormality is similar to achalasia. Two of these four patients have benefited from pneumatic dilatation with improvement in their severe dysphagia. We believe that pneumatic dilatation should be considered in patients with systemic sclerosis and severe dysphagia where reflux oesophagitis is not apparent.

Adult↗
PubMed1990

Magnesium deficiency in patients on home enteral nutrition.

Home enteral nutrition (HEN) is an established method of long term nutritional support. Many patients receiving HEN have Crohn's disease complicated by intestinal failure and malnutrition, including magnesium deficiency. It is unknown if HEN can correct magnesium deficiency or if patients on HEN can become magnesium deficient. We measured total magnesium intake in nine patients receiving HEN, and assessed their magnesium status. Two patients had magnesium intakes below the recommended dietary allowance of 15 mmol/day. Four patients (44%) had biochemical evidence of magnesium deficiency, although no patient had clinical signs of magnesium deficiency. Several magnesium deficient patients used a liquid feed which had a low magnesium content. Patients on HEN should have their magnesium status checked regularly and may require magnesium supplements.

Journal Article↗
PubMed1990

Gastric antral vascular ectasia (watermelon stomach)--therapeutic options.

We have encountered five cases of chronic iron deficiency anaemia due to bleeding from gastric antral vascular ectasia (watermelon stomach). Two cases were associated with a lymphoma and in three cases there was evidence of portal hypertension. Two patients were treated conservatively by blood transfusions. The other patients required either surgery or tranexamic acid or endoscopic laser therapy to control the chronic haemorrhage.

Aged↗