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Biomedical subjects

A J Park

Publications and source records attributed to A J Park.

At least 19 recordsLinked to original sources
PubMed2006

Endothelial progenitor cells in pterygium pathogenesis.

PURPOSE: The pathogenesis of pterygium is not well known, and controversy exists about the cell origins and the nature of initial trigger required for its development. We investigated whether endothelial progenitor cells (EPCs) are involved in pathogenesis of pterygium and the mechanism underlying the selective recruitment of EPCs during this process. METHODS: We studied 13 normal controls and 28 pterygium patients (primary (n=15), recurrent (n=13)). Substance-P, vascular endothelial growth factor (VEGF), and stem cell factor (SCF) were measured in plasma and tears using ELISA, and circulating CD34(+) and c-kit(+) mononuclear cells (MNCs) by flow cytometry. Anterior segment fluorescein angiography (FAG) was performed to evaluate hypoxic conditions in the early stage of pterygium. Surgically removed pterygial tissues were analyzed immunohistochemically using the progenitor cell markers, CD34, c-kit, VEGFR-1, and VEGFR-2. RESULTS: Anterior segment FAG findings showed an increase in non-perfusion areas and attenuated vessels in the nasal limbus during early-stage pterygium. Circulating CD34(+) MNCs and c-kit(+) MNCs were increased in pterygium groups compared with normal controls. Systemic and local cytokines including SP, VEGF, and SCF in pterygium groups were also elevated and showed positive correlations with CD34(+) and c-kit(+) MNC numbers. Immunohistochemical analysis of pterygium showed strong progenitor cell marker immunoreactivities. CONCLUSIONS: EPCs might be involved in pterygium development, and ocular hypoxia triggers this neovascularization by recruiting EPCs derived from the bone marrow via the production of systemic and local cytokines.

Age Distribution↗
PubMed2006

Oxyntomodulin increases energy expenditure in addition to decreasing energy intake in overweight and obese humans: a randomised controlled trial.

BACKGROUND: Oxyntomodulin has recently been found to decrease body-weight in obese humans and may be a potential anti-obesity therapy. OBJECTIVE: To determine whether oxyntomodulin alters energy expenditure, in addition to reducing energy intake, in 'free-living' overweight and obese volunteers. DESIGN: Randomized double-blind controlled cross-over trial. SETTING: Community and hospital-based. PARTICIPANTS: Fifteen healthy overweight and obese men and women (age: 23-49 years, BMI: 25.1-39.0 kg/m(2)). All volunteers completed the study protocol. INTERVENTIONS: Four-day subcutaneous self-administration of pre-prandial oxyntomodulin, three times daily. Participants were advised to maintain their normal dietary and exercise regimen. MEASUREMENTS: (1) Energy expenditure, measured by indirect calorimetry and combined heart rate and movement monitoring; (2) energy intake, measured during a study meal. RESULTS: Oxyntomodulin administration reduced energy intake at the study meal by 128+/-29 kcal (P=0.0006) or 17.3+/-5.5% (P=0.0071), with no change in meal palatability. Oxyntomodulin did not alter resting energy expenditure; but increased activity-related energy expenditure by 143+/-109 kcal/day or 26.2+/-9.9% (P=0.0221); total energy expenditure by 9.4+/-4.8% (P=0.0454) and physical activity level by 9.5+/-4.6% (P=0.0495). A reduction in body weight of 0.5+/-0.2% was observed during the oxyntomodulin administration period (P=0.0232). CONCLUSION: Oxyntomodulin increases energy expenditure while reducing energy intake resulting in negative energy balance. This data supports the role of oxyntomodulin as a potential anti-obesity therapy.

Adult↗
PubMed2005

Ghrelin increases food intake in obese as well as lean subjects.

OBJECTIVE: To investigate whether effects on food intake are seen in obese subjects receiving exogenous administration of ghrelin. DESIGN: Randomised, double-blind, placebo-controlled study of intravenous ghrelin at doses 1 pmol/kg/min and 5 pmol/kg/min. SUBJECTS: In all, 12 healthy lean subjects (mean body mass index (BMI) 20.5+/-0.17 kg/m(2)) and 12 healthy overweight and obese subjects (mean BMI 31.9+/-1.02 kg/m(2)). MEASUREMENTS: Food intake, appetite and palatability of food, ghrelin and other obesity-related hormones, growth hormone. RESULTS: Low-dose infusion of ghrelin increased ad libitum energy intake at a buffet meal in the obese group only (mean increase 36.6+/-9.4%, P<0.01.) High-dose ghrelin infusion increased energy intake in both groups (mean increase 20.1+/-10.6% in the lean and 70.1+/-15.5% in the obese, P<0.01 in both cases.) Ghrelin infusion increased palatability of food in the obese group. CONCLUSION: Ghrelin increases food intake in obese as well as lean subjects. Obese people are sensitive to the appetite-stimulating effects of ghrelin and inhibition of circulating ghrelin may be a useful therapeutic target in the treatment of obesity.

Adult↗
PubMed2004

A-a type, arterialized, venous, flow-through, free flap for simultaneous digital revascularization and soft tissue reconstruction-revisited.

Significant soft tissue injuries to palmar surfaces are frequently associated with digital vessel damage. Flap coverage might have to be combined with microsurgical revascularization using vein grafts if the digit is to be salvaged. Two cases of simultaneous digital revascularization and soft tissue reconstruction using an arterialized, venous flow-through flap are presented in detail. These flaps initially "pinked up" for 24 to 48 hours. This was followed by a period of venous congestion lasting approximately 1 week, after which flap perfusion gradually returned to normal. Good long-term functional and cosmetic results were achieved. Distal finger perfusion was maintained in both cases. This technique, although previously described, has not been popularized. It should be considered early in reconstruction of ischemic digits requiring simultaneous vascular and soft tissue reconstruction.

Female↗
PubMed2003

Flame bums: a forgotten danger of diathermy?

Diathermy and spirit-based skin preparations are both used on a daily basis in most hospital theatres. We report a case illustrating the potential hazards of this combination and discuss the management of its complications and possibilities of their prevention.

Aged↗
PubMed2003

Pancreatic polypeptide reduces appetite and food intake in humans.

Pancreatic polypeptide (PP) is a gut hormone released from the pancreas in response to ingestion of food. Plasma PP has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa. In addition peripheral administration of PP has been shown to decrease food intake in rodents. These findings suggest that PP may act as a circulating factor that regulates food intake. Therefore we investigated the effect of intravenous infusion of PP (10 pmol/kg/min) on appetite and food intake in a randomised double-blind placebo-controlled crossover study in ten healthy volunteers. Infusion of PP reduced appetite and decreased the energy intake at a buffet lunch two hours post-infusion by 21.8 +/- 5.7% (P < 0.01). More importantly the inhibition of food intake was sustained, such that energy intake, as assessed by food diaries, was significantly reduced both the evening of the study and the following morning. Overall PP infusion reduced cumulative 24-hour energy intake by 25.3 +/- 5.8%. In conclusion our data demonstrates that PP causes a sustained decrease in both appetite and food intake.

Adolescent↗
PubMed2001

Rapid species identification of coagulase negative Staphylococci by rRNA spacer length polymorphism analysis.

OBJECTIVES: The identification of coagulase-negative staphylococci (CNS) is carried out mainly through conventional methods, commercial identification kits, and molecular biology-based methods. We evaluated the efficiency of PCR analysis of tRNA intergenic spacer length polymorphism (tDNA-ILP) and 16S-23S intergenic spacer length polymorphism (16S-23S ILP), and also that of restriction analysis of 16S-23S intergenic spacer amplification products (RA 16S-23S), for the rapid and accurate identification of CNS species. METHODS: The PCR assays of rRNA spacer length polymorphisms were tested with nine reference type strains and 122 clinical isolates. The results were compared with those obtained by conventional methods and the Vitek system for clinical isolates. RESULTS: Seventy-eight (63.9%) of 122 strains were identified as the same species with conventional identification, the Vitek GPI system, tDNA-ILP, and RA 16S-23S. The 16S-23S ILP analysis did not produce distinguishable PCR fragments. The results of tDNA-ILP analysis were in agreement with those of RA 16S-23S to the species level for 98.2% except for unknown patterns (eight isolates). CONCLUSIONS: These results indicate that tDNA-ILP and RA 16S-23S analysis are potentially valuable tools for rapid and accurate CNS identification.

Coagulase↗
PubMed2001

Antimicrobial resistance surveillance of bacteria in 1999 in Korea with a special reference to resistance of enterococci to vancomycin and gram-negative bacilli to third generation cephalosporin, imipenem, and fluoroquinolone.

The trend of antimicrobial resistance of bacteria isolated from patients in 30 Korean hospitals in 1999 was analyzed with a particular attention to cefotaxime- or fluoroquinolone-resistant gram-negative bacilli, imipenem-resistant Pseudomonas aeruginosa, and vancomycin-resistant enterococci. Adequacy of susceptibility testing, and any change in the frequencies of isolated species were also analyzed. The results showed that only 20% and 30% of hospitals tested the piperacillin-tazobactam and cefoxitin susceptibility of Enterobacteriaceae, respectively, only 24% of hospitals the piperacillin-tazobactam susceptibility of P. aeruginosa, and 17% of hospitals the fusidic acid susceptibility of staphylococci. Among the isolates 26.3% were glucose-nonfermenting gram-negative bacilli, and 34.7% of Enterococcus were Enterococcus faecium. Slight decline of cefotaxime-resistance rate to 20% was noted in Klebsiella pneumoniae, while fluoroquinolone-resistance rate was 68% in Acinetobacter baumannii. The ceftazidime- and imipenem-resistance rates were 17% and 18%, respectively in P. aeruginosa. The vancomycin-resistance rate of E. faecium rose significantly to 15.1%, but the rates varied significantly depending on hospitals suggesting presence of different degree of selective pressure or nosocomial spread. In conclusion, the prevalence of imipenem-resistant P. aeruginosa and the increase of vancomycin-resistant E. faecium were the particularly worrisome phenomena observed in this study.

Anti-Bacterial Agents↗
PubMed2001

Apolipoprotein E genotype in Korean schizophrenic patients.

The apolipoprotein E (APOE) epsilon4 allele is a known risk factor for the development of Alzheimer's disease, however, an association of the APOE genotype with schizophrenia is controversial. We investigated the association in 60 Korean schizophrenic patients and 60 healthy controls. APOE genotypes were identified by reverse hybridization-based line probe assay. There were significant differences in the distribution of APOE genotypes between schizophrenic patients and controls. APOE epsilon2 and epsilon3 allele frequencies in schizophrenic patients were significantly different from those in controls. Our results suggest that APOE alleles seem to be operative in the pathogenesis of schizophrenic disorders.

Adult↗
PubMed2000

alpha-Galactosidase A from Pseudomonas fluorescens subsp. cellulosa: cloning, high level expression and its role in galactomannan hydrolysis.

A library of Pseudomonas fluorescens subsp. cellulosa genomic DNA, constructed in lambda ZAPII, was screened for alpha-D-galactosidase activity. The DNA inserts from six galactosidase-positive clones were rescued into plasmids. Restriction digestion and Southern analysis revealed that each of the plasmids contained a common DNA sequence. The sequence of the Pseudomonas DNA in one of the plasmids revealed a single open reading frame (aga27A) of 1215 bp encoding a protein of M(r) 45900, designated alpha-galactosidase 27A (Aga27A). Aga27A exhibited extensive sequence identity with alpha-galactosidases in glycoside hydrolase 27, and appeared to be a single domain protein. The recombinant alpha-galactosidase was expressed at high levels in Escherichia coli and the biophysical properties and substrate specificity of the enzyme were evaluated. The data showed that Aga27A was a mesophilic neutral acting non-specific alpha-galactosidase. Both P. fluorescens subsp. cellulosa mannanase A (ManA) and Aga27A hydrolyse the polymeric substrate, carob galactomannan. Sequential hydrolysis with AgaA followed by ManA, or ManA followed by AgaA enhanced product release. The positive effects of sequential hydrolysis are discussed.

Amino Acid Sequence↗
PubMed1998

Silicone gel-filled breast implants and connective tissue diseases.

Recent worldwide press and media speculation that silicone implants may be linked to an increased incidence of breast cancer, other cancers, and connective tissue diseases-particularly systemic sclerosis-is a current cause for concern to the medical profession and public alike. We conducted a cross-sectional study of the prevalence of connective tissue diseases, as well as signs and symptoms associated with these conditions, in women who had received a silicone gel-filled breast implant for either breast augmentation or breast reconstruction following mastectomy for breast cancer compared with women without implants in South East Scotland. We compared 317 patients who had had a silicone gel-filled breast implant inserted with matched controls. We found no increased incidence of antinuclear antibodies or rheumatoid factor in the study groups. We detected one case of rheumatoid arthritis in the reconstruction group and one in matched controls, but no cases of any other connective tissue disease. No cases were found among the augmentation patients or their controls. No differences were found in symptoms or physical signs of connective tissue diseases between the study patients and their controls. This study has failed to find any case for a link between silicone gel-filled breast implants and connective tissue diseases.

Adolescent↗
PubMed1998

Korean Nationwide Surveillance of Antimicrobial Resistance of bacteria in 1997.

Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea. Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997. Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin. Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted. The resistance rate to fluoroquinolone rose to 24% in E. coli, 56% in A. baumannii and 42% in P. aeruginosa. Mean resistance rates were similar in all hospital groups: about 17% of P. aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin. In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.

Bacterial Physiological Phenomena↗
PubMed1998

Gynaecomastia: have Webster's lessons been ignored?

Five cases of cosmetically unacceptable and hypertrophic scarring are presented that follow excision of gynaecomastia by surgeons who used incisions other than the periareolar approach. A periareolar technique of subcutaneous mastectomy is described and recommended.

Adolescent↗
PubMed1998

What do plastic surgeons do?

The image of plastic surgery as portrayed by the media is of concern to all plastic surgeons. In order to assess knowledge about the specialty, a questionnaire was devised and given to five groups of participants: general practitioners, medical students, nurses, plastic surgical out-patient attendees, and the general public. The results revealed that general practitioners, nurses and medical students in the Cambridge area are, on the whole, knowledgeable about the role of plastic surgery. However, the general public are not so well educated and 23.7% of them could not think of five conditions treated by plastic surgeons, and felt that burns and cosmetic problems were the commonest conditions dealt with. Improved liaison with general practitioners, other specialties and more teaching of undergraduates, coupled with more effective promotion of the skills on offer might permit better use to be made of the specialty.

Health Knowledge, Attitudes, Practice↗
PubMed1996

Patient satisfaction following insertion of silicone breast implants.

Because of allegations linking silicone implants with cancer and connective tissue diseases and mounting media coverage, women with silicone breast implants are extremely concerned, despite the lack of evidence showing a link between silicone gel-filled breast implants and connective tissue diseases or cancer. To assess whether or not this group of women were satisfied with their operations, we sent all women who had silicone breast implants inserted in the south-east of Scotland between 1982 and 1991 a quality of life questionnaire. One hundred and two breast augmentation and 212 breast reconstruction patients replied. Not everyone answered every question. The majority of women in our study, 84% (79/94) and 91.8% (192/209) of augmented and reconstructed patients, respectively, stated that they were satisfied with their operations, although only about half were very satisfied. Although 91.2% (270/296) of all the women were aware of the allegations with 29.7% (88/296) concerned, only 3% (9/296) of all the women felt that there was cause for concern. It would appear that, although most women with silicone breast implants are aware of the accusations regarding silicone and systemic illnesses, the adverse publicity has only given a small number of them a cause for concern and the majority are satisfied with the outcome of their operation and perceive the benefits to outweigh the risks.

Adolescent↗
PubMed1996

The detection of breast implant rupture using ultrasound.

Because little or no information exists about the life span of silicone implants, there is a need for a non-invasive and sensitive diagnostic tool for assessing their integrity. It is extremely difficult to diagnose rupture of these implants clinically. The aims of this study were to assess how many of our patients--in particular asymptomatic women--had ruptured implants and whether or not ultrasound was an effective tool in excluding rupture and reassuring anxious patients. All patients in the south east of Scotland who had a silicone gel-filled breast implant inserted between the years 1982-1991 were invited to take part in an investigation into morbidity due to silicone implants. We screened 307 asymptomatic patients with 385 implants and only found one patient with a ruptured silicone implant. One other patient had a ruptured saline implant and one implant was found to have leaked. We found ultrasound to be a quick, reliable, cheap and safe method of screening for implant rupture which can be used to reassure an anxious patient that her implants are intact.

Adult↗
PubMed1996

Munchausen's syndrome--masquerading as necrotizing fasciitis.

We would like to present a novel form of Munchausen's syndrome which presented us with a difficult problem in the midst of the recent media hysteria regarding flesh eating bacteria. This condition, first described by Richard Asher in 1951, is often very difficult to diagnose and it is not, therefore, surprising that the victims have been through several episodes of treatment before the suspicions of staff are raised. It owes its name to a fictitious character, Baron Karl Friedrich Hieronymus Freihess von Munchausen, who recounted extraordinary and wildly exaggerated exploits of adventure and daring, not unlike patients who present with this condition. Our enquiries revealed that the laid down procedure when faced with a patient with this condition is that the regional medical officer (RMO) should be contacted. It is then his responsibility to contact other RMOs, who in turn pass the information on to accident and emergency consultants in their area.

Adult↗