Biomedical subjects

M S Chung

Publications and source records attributed to M S Chung.

At least 37 records · Page 2Linked to original sources

PubMed2001

Changes in ulnar variance in relation to forearm rotation and grip.

We studied radiographs of the wrists of 120 healthy volunteers in order to determine the normal range of ulnar variance. They had been taken in various positions under both unloaded (static) and loaded (dynamic) conditions. Pronation posteroanterior, supination anteroposterior and neutral posteroanterior views were taken of each wrist before and during a maximum grip under identical conditions. The mean normal ulnar variance in neutral rotation was +0.74+/-1.46 mm, a value which was significantly lower in males than in females. We found negative variance in 26% of cases. We measured maximum ulnar variance (UVmax +1.52+/-1.56 mm) when gripping in pronation and minimum ulnar variance (UVmin +0.19+/-1.43 mm) when relaxed in supination. We subtracted UVmin from UVmax to calculate a mean maximum dynamic change in ulnar variance of 1.34+/-0.53 mm. We consider this database of normal values to be useful for both the diagnosis and treatment of conditions related to discrepancy in radio-ulnar length and for clinical research.

Adult↗

PubMed2001

PCR-RFLP patterns of four isolates of Trichinella for rDNA ITS1 region.

We have studied the genetic differences among four isolates of Trichinella including a new strain of Trichinella spiralis (ISS 623) recently found from a human case who took a badger in Korea. Because they have a different host origin and came from geographically separated regions, we supposed the genetic pattern of the isolates might be different as had been previously reported. It was analysed by PCR-RFLP analysis of the rDNA repeat that can readily distinguish a species or strain from others. Isolated genomic DNA of each isolate of Trichinella larvae was amplified with ITS1 specific primers and digested with restriction endonucleases. The PCR product of ITS1 was confirmed using Southern blot analysis to be a 910 bp fragment. The restriction fragments of each isolate had variable patterns when it was digested with Rsa 1 only. According to the RFLP patterns, the estimated genetic divergence between each isolate was different. In conclusion, four isolates of Trichinella including a new strain of T. spiralis obtained from a Korean patient may have genetic differences in the ITS1 region and the Shanghai isolate was genetically more similar to the Japanese unknown isolate than others in the ITS1 region.

Animals↗

PubMed2001

Monitoring of microbial hazards at farms, slaughterhouses, and processing lines of swine in Korea.

This study was executed to investigate microbiological hazards at swine farms, slaughterhouses, dressing operations, and local markets for the application of the hazard analysis critical control point system in Korea by analyzing total aerobic plate count (APC) and presence of pathogens. Six integrated pig farms and meat packers were selected from six different provinces, and samples were collected from pig carcasses by swabbing and excision methods at the slaughterhouses, processing rooms, and local markets, respectively. APCs of water in water tanks were relatively low, 1.9 to 3.1 log10 CFU/ml; however, they were increased to 4.6 to 6.9 log10 CFU/ml when sampled from water nipples in the pigpen. APCs of feeds in the feed bins and in the pigpens were 4.4 to 5.4 and 5.2 to 6.7 log10 CFU/g, respectively. Salmonella spp., Staphylococcus aureus, and Clostridium perfringens were detected from water and feed sampled in pigpens and pigpen floors. S. aureus was the most frequently detected pathogenic bacteria in slaughterhouses and processing rooms. Listeria monocytogenes and Yersinia enterocolitica were also detected from the processing rooms of the Kyonggi, Kyongsang, and Cheju provinces. Even though APCs were maintained at the low level of 3.0 log10 CFU/g during slaughtering and processing steps, those of final pork products produced by the same companies showed relatively high numbers when purchased from the local market. These results indicated that the cold chain system for transporting and merchandising of pork products was deficient in Korea. Water supply and feed bins in swine farms and individual operations can be identified as critical control points to reduce microbiological hazards in swine farms, slaughterhouses, and processing plants.

Abattoirs↗

PubMed2000

Mycobacterium chelonae keratitis after laser in situ keratomileusis successfully treated with medical therapy and flap removal.

PURPOSE: To report a case of Mycobacterium chelonae keratitis after laser in situ keratomileusis successfully treated with medical therapy and flap removal. METHODS: Case report. A 36-year-old white woman in good health developed a paracentral keratitis in her right eye 1 month after bilateral laser in situ keratomileusis. Initial treatment included topical steroids and then intensive Ocuflox (ofloxacin ophthalmic solution; Allergan, Inc, Irvine, California) without success. Cultures were negative. The keratitis worsened, and she was referred to our institution. Interface infiltration was noted, and the flap was lifted to obtain adequate laboratory studies. Cultures were positive for M chelonae. RESULTS: The keratitis was treated with intensive topical amikacin sulfate 1%, topical clarithromycin 1%, and Ciloxan (ciprofloxacin HCL; Alcon Laboratories, Inc, Fort Worth, Texas) with minimal improvement in her clinical condition. She developed a toxic reaction to amikacin 1%. In order to improve antibiotic penetration, the hazy, ulcerated corneal flap was removed. The keratitis then resolved with intensive topical clarithromycin 1% and Ocuflox over 5 weeks. The patient now has visual acuity without correction of 20/50, despite superficial corneal haze. CONCLUSION: M chelonae is a rare and insidious cause of infection after laser in situ keratomileusis. Diagnosis can be difficult and is often delayed. Aggressive medical management, with flap removal, if needed, may lead to resolution of infection.

Adult↗

PubMed2000

Fungal keratitis after laser in situ keratomileusis: a case report.

PURPOSE: To report a case of fungal keratitis resulting after laser in situ keratomileusis (LASIK). METHODS: A 38-year-old white man in good health developed a corneal infiltrate with laboratory confirmation of fungal keratitis after LASIK. Corneal scrapings were taken. Silver stain was positive for hyphae. Culture was positive for Curvularia sp. The patient was started on intensive natamycin 5% and amphotericin 0.15% topical therapy. RESULTS: The patient's keratitis was successfully treated with intensive antifungal therapy. CONCLUSIONS: Infectious keratitis is a rare but a serious potential complication after LASIK. To our knowledge, no previous case of fungal keratitis after LASIK has been reported. This case emphasizes the importance of surveillance for infection after LASIK.

Adult↗

PubMed2000

Raynaud's phenomenon in idiopathic carpal tunnel syndrome: postoperative alteration in its prevalence.

In a previous study the prevalence of Raynaud's phenomenon (RP) in patients with idiopathic carpal tunnel syndrome (CTS) was found to be 60% which is much higher than that in the general population. We undertook a further study of the same cohort of patients have both CTS and RP and who had an open release of the carpal tunnel, to observe the effects of the operation on RP. We observed whether the symptoms of RP improved, and repeated the cold provocation tests to see if the arterial pulse which was decreased before operation would recover. We rated the outcome as good when the patients showed both an improvement of the symptoms of RP and a normal pulse amplitude after exposure to cold, fair when the pulse amplitude recovered to more than two-thirds of that before exposure, and poor when cold hypersensitivity was persistent or showed the same degree of decreased pulse amplitude as observed before operation. Of the 18 patients with both conditions, ten (56%) had good and four (22%) fair results, with a mean recovery time of 4.2 months (6 weeks to 1 year) after operation. If the vasospasm seen in RP is an expression of vasomotor irritation in the carpal tunnel, these findings suggest that local compression of vasomotor fibres in the carpal tunnel can also be relieved by the release of this structure. Careful consideration, however, is still required in treating patients with both conditions since in some cases. RP may be superimposed or it may have other origins.

Age of Onset↗

PubMed2000

Three-dimensional image and virtual dissection program of the brain made of Korean cadaver.

The three-dimensional (3D) structure of the brain needs to be understood for accurate diagnosis and treatment of brain diseases. The brain of a cadaver may not always be available for dissection when it is needed. To overcome this problem, we attempted to create a 3D image and virtual dissection program of the brain using a Korean cadaver. The brain extracted from a Korean male cadaver was embedded in gelatin solution. 130 MRI of the brain were taken and 130 serially-sectioned specimens were made. All of MRI and specimens were inputted into the computer, and 10 brain components were manually segmented. A 3D image and virtual dissection program of the brain was made. Various virtual dissection functions were established, such as 1) sectioning the 3D image of the brain at free angles to represent its plane as a real image, segmented image, and MRI, 2) identifying the brain components represented in the sectioned plane, and 3) rotating the 3D image of the whole brain or the selected brain components at free angles. The resulting virtual dissection program of the brain is helpful in better understanding the 3D location and shape of the brain components and it is expected to be used as a CD-title or through Internet as an educational tool for medical students and doctors.

Brain↗

PubMed2000

Survival of Pseudomonas fluorescens and Salmonella typhimurium after electron beam and gamma irradiation of refrigerated beef.

The radurization effects of gamma ray and electron beam irradiation at 1.5 and 3.0 kGy on beef steaks inoculated with Salmonella Typhimurium and Pseudomonas fluorescens were investigated during 8 days of storage at 5 degrees C. Total bacterial counts and numbers of Salmonella Typhimurium and P. fluorescens were analyzed at 2-day intervals. Total bacterial counts of samples irradiated by both gamma rays and electron beam were significantly (P < 0.05) reduced by 3.8 to 5.3 log CFU/g. Salmonella Typhimurium was not detectable during the experimental period. P. fluorescens counts of beef samples irradiated by gamma rays at both 1.5 and 3.0 kGy were not detected; however, P. fluorescens in samples irradiated by electron beam at 1.5 and 3.0 kGy was recovered after 2 days, and bacterial counts reached 7.8 and 6.9 log CFU/g, respectively. Both gamma ray and electron beam irradiation reduced total bacterial counts initially, possibly extending shelf life. Irradiation was very effective in destroying Salmonella Typhimurium; however, P. fluorescens was not completely eliminated by electron beam irradiation. Consequently, gamma ray irradiation was more effective than electron beam irradiation in the destruction of P. fluorescens.

Animals↗

PubMed2000

Chemotherapeutic efficacy of praziquantel in rats with protective immunity to Clonorchis sinensis infection.

OBJECTIVE: To study the synergic effect of praziquantel (PZQ) and host acquired immunity on Clonorchis sinensis. METHODS: Acquired immunity to C. sinensis was induced by immunization with crude adult worm antigen (AW Ag) and excretory-secretory antigen (ES Ag) or infection with C. sinensis metacercariae. The effect was assessed by the worm reduction rate compared with the control groups after challenge infection with 50 metacercariae and treated orally with a subcurative dose of praziquantel (50 mg/kg). Significant test was performed by analysis of variance (ANOVA) and Npar1 way Kruskal-Wallis test. All calculations were performed by PC-SAS system. RESULTS: 1. PZQ was more effective against C. sinensis larvae than against adult worms in the control (P < 0.001), ES Ag (P < 0.01) or crude AW Ag immunization group (P < 0.001). 2. As compared with the control, the worm reduction rate after challenge infection was significantly higher (P < 0.001) in ES Ag immunized group (35.6%) and metacercaria infection group (97.5%) and less in crude AW Ag group (23.4%). The PZQ efficacy was significantly enhanced in ES Ag immunized group. CONCLUSION: The efficacy of PZQ against C. sinensis could be synergically enhanced in rats by inducing host acquired immunity.

Animals↗

PubMed1999

Patient with lichen planus and conjunctival immunopathologic features of lupus erythematosus.

PURPOSE: To report a case of severe cicatricial conjunctivitis in a patient with lichen planus, which is known to affect the skin and mucous membranes. The conjunctival immunopathologic features were consistent with lupus erythematosus rather than with lichen planus. METHOD: Oral mucosal and skin biopsies were performed with histopathologic and immunofluorescent studies consistent with lichen planus. The patient later had a biopsy of cicatrized conjunctiva with histopathologic and immunofluorescent findings consistent with lupus erythematosus. Evaluation by rheumatology and dermatology consultants demonstrated no evidence of active systemic lupus erythematosus or discoid lupus erythematosus. RESULTS: The patient was treated with topical and systemic immunosuppressives and her disease eventually stabilized. CONCLUSION: The case demonstrates two coexisting autoimmune disease entities: lichen planus of the skin and oral mucosa and a cicatricial conjunctivitis consistent with lupus erythematosus.

Biopsy↗

PubMed1999

Transfer of extensor carpi radialis longus or brevis for opponensplasty.

For the restoration of thumb opposition many types of tendon transfer techniques have been described. The flexor digitorum superficialis (FDS) of the ring finger is commonly selected as a motor. On occasion, however, the quality of the flexor muscles of the fingers or wrist is not good enough for tendon transfer and another available muscle must be selected. In this situation, we have preferred to use an extensor carpi radialis longus (ECRL) or brevis (ECRB) transfer to restore opposition of the thumb. Follow-up examination, at an average 5 years and 10 months after operation, showed that the results of ten of 11 transfers were excellent and the other was good.

Adolescent↗

PubMed1999

Purification and characterization of Aspergillus ficuum endoinulinase.

Endoinulinase from Aspergillus ficuum, which catalyzes the hydrolysis of inulin via an endo-cleavage mode, was purified by chromatography from Novozym 230 as a starting commercial enzyme mixture on CM-Sephadex and DEAE-Sepharose, and by preparative electrophoresis under native conditions. The enzyme was estimated to be pure on the basis of its I/S ratio, whose value was infinite in our assay conditions. Two forms separated by using this method. SDS gel electrophoresis showed the two purified forms to respectively exhibit molecular weights of 64,000 +/- 500 and 66,000 +/- 1,000. The results of deglycosylation indicated that the two forms were originally the same protein but with different sugar contents. A molecular weight of 54,800 +/- 1,500 was found by gel filtration of the native enzyme, indicating the native functional protein to be a monomer. The enzyme showed nearly absolute substrate specificity towards inulin and inulooligosaccharides, and acted via an endo-attack to produce mainly inulotriose during the late stage of the reaction. The apparent Km and Vmax values for inulin hydrolysis were 8.1 +/- 1.0 mM and 773 +/- 60 U/mg, respectively. The internal peptides of the enzyme showed sequence homology to the endoinulinase of Penicillium purpurogenum.

Amino Acid Sequence↗

PubMed1999

Prevalence of Raynaud's phenomenon in patients with idiopathic carpal tunnel syndrome.

Both idiopathic carpal tunnel syndrome (CTS) and Raynaud's phenomenon (RP) are common, and may have similar clinical symptoms. The degree of their coexistence is uncertain. We have examined 30 patients, who were diagnosed clinically and electromyographically as having idiopathic CTS, for the presence of RP using a cold provocation test with photoplethysmography. The patients' hands were exposed in water at 10 degrees C for five minutes. A total of 18 patients (60%) was found to have RP; this is much greater than would be expected from the prevalence in the general population. Raynaud's phenomenon should be considered when treating patients with CTS because of the possibility of coexistence and the similar symptoms of these two disorders.

Adult↗

PubMed1998

A free energy analysis by unfolding applied to 125-mers on a cubic lattice.

BACKGROUND: A common approach to the protein folding problem involves computer simulation of folding using lattice models of amino acid sequences. Key factors for good performance in such models are the correct choice of the temperature and the average interaction energy between residues. In order to push the lattice approach to its limit it is important to have a method to adjust these parameters for optimal folding that is not limited by our ability to successfully simulate folding in a reasonable time. RESULTS: In this study, we adopt a simple cubic-lattice model and present a method for calculating the free energy of a chain as a function of the number of native contacts. This does not require that we are able to fold the sequence by simulation and it provides a method of estimating the folding transition temperature. For a given set of parameters, the free energy analysis also allows an estimate of foldability. By applying the method to sequences with 27 and 125 residues, we show that optimal folding occurs near the folding transition temperature and at either zero or small negative average interaction energy. We find ourselves able to fold only 125-mers that have significant short-range native contacts. CONCLUSIONS: A free energy analysis during unfolding is a useful tool for the study of foldability and should be applicable to a variety of folding models. In this way we are able to fold some 125-mer designed sequences and our results confirm the finding that short-range contacts contribute to foldability.

Markov Chains↗

PubMed1998

The treatment of congenital brachymetatarsia by one-stage lengthening.

We performed one-stage lengthening using intercalary autogenous bone graft in 34 metatarsals and seven proximal phalanges in 21 patients with congenitally short metatarsals. At operation, in order to decrease the tension in the surrounding soft tissues, we gradually distracted the osteotomies of the affected bones for 20 to 30 minutes. The patients, all women, were followed up for a mean period of 2.1 years (1 to 6.5). The average gain in length for the 34 metatarsal procedures was 14 mm (6 to 21), equivalent to an increase of 32% (11 to 51), and for the seven proximal phalangeal lengthenings 8 mm (5 to 11), an increase of 54% (47 to 65). There was no evidence of neurovascular impairment. The technique of gradual distraction during operation is simple and effective. It overcomes the disadvantages of one-stage lengthening such as a small gain in length and neurovascular damage.

Adolescent↗

PubMed1997

Changing patterns of Clonorchis sinensis infections in Kyongbuk, Korea.

Studies were conducted from May, 1993 to April, 1995 to determine the changing patterns of infection by the liver fluke, Clonorchis sinensis, among residents and fish hosts in Kyongbuk Province. The infection rate among residents was 7.7% by stool examination. The rate in males (11.3%) was significantly higher than females (4.1%). Positive rate of intradermal test was 27.6% in the same population. The special type of a simple catalytic model was applied for the analysis of intradermal positive reactors by age and sex, and the equation was y = 0.4776 (1 - e-0.0375t) for males and, y = 0.2085 (1 - e-0.0138t) for females. Analysis of stool examination data by two-stage catalytic model revealed y = 0.025 (e-0.00471 - e-0.0235t). The annual Clonorchis infection rate was 4.7 per 1,000 susceptibles and the annual loss rate was 23.5 per 1,000 infected. The frequency distribution by the eggs per gram (EPG) was calculated as well as the cumulative percentages of positives. The regression equations were y = 0.929 + 1.506 log x for males and, y = 0.473 + 1.767 log x for females. Of the 25 fish species, 7 species were infected with Clonorchis metacercariae. Infection rates varied by the species, and ranged from 2.8% in Puntungia herzi to 30.0% in Pseudorasbora parva. Average number of the matacercariae per gram of flesh was 58.1 in P. parva, followed by 10.2 in Gnathopogon atromaculatus, 7.0 in Saurogobio dabryi, and 3.0 in Paracheilognathus rhombea. The present study indicates that clonorchiasis in Kyongbuk Province is less prevalent than that of several decades ago.

Adolescent↗

PubMed1996

The infestation states and changing patterns of human infecting metacercariae in freshwater fish in Kyongsang-do and Kyonggi-do, Korea.

The infestation rates and abundances of human infecting metacercariae (Clonorchis sinensis, Metagonismus spp., Centrocestus armatus, Echinostoma hortense, Echinochasmus japonicus, Clinostomum complanatum) in freshwater fish were investigated at the three river areas-Taewhagang (river), Hyongsangang (river), Nakdonggang (river) -in Kyongsang-do and at four streams-Yonpungchon, Munsanchon, Kyonganchon, and Konjiamchon-in Kyonggi-do, Korea in 1994-1995. The fish caught at Taewhagang were heavily infested with metacercariae of Clonorchis sinensis and Centrocestus armatus. At Hyongsangang, Zacco platypus and Z. temmincki were moderately infested with metacercariae of C. armatus. Chomanpo, at the basin of Nakdonggang, was still endemic for C. sinensis. In the fish caught at four streams of Kyonggi-do, metacercariae of C. sinensis exhibited the highest infestation rate and intensity out of 6 species of metacercariae. The infestation intensity of C. sinensis metacercariae in fish flesh was markedly different according to each division of flesh. The cause of this difference was conjectured as a result of larval behavior. The metacercariae of C. armatus were found in almost all parts, except scales and fins, of fish. The infestation rates and intensities of C. sinensis and C. armatus metacercariae in Taewhagang greatly increased as compared with those of previous reports. Rhinogobius brunneus and Acanthorhodeus macropterus are newly recorded intermediate hosts of Echinostoma hortense. The reason of large differences from previous data was discussed and the standard method of metacercaria examination was proposed.

Animals↗

PubMed1996

Handling and clinical performance of a glass ionomer sealant.

PURPOSE: To compare the handling and 6-month clinical performance of an experimental resin-modified glass ionomer cement (K-512 = Fuji III LC) with that of a light-cured resin-based sealant (Delton Opaque) when used as a pit and fissure sealant in 15-27 year old subjects. MATERIALS AND METHODS: Seventeen patients with 65 cement and 55 resin-based sealants were recalled after 6 months for clinical examination and color photographs. RESULTS: Sealant retention failures requiring retreatment were 74% for the glass ionomer cement sealant and 11% for the resin-based sealant, with one instance of fissure caries being found for each material. The resin-modified glass ionomer cement sealant showed a slight darkening from its initial placement, and was also more difficult to handle than the resin-based sealant.

Adolescent↗