Effect of surface defects and cross-sectional configuration on the fatigue fracture of NiTi rotary files under cyclic loading / 대한치과보존학회지

The purpose of this in vitro study was to evaluate the effect of surface defects and cross-sectional configuration of NiTi rotary files on the fatigue life under cyclic loading. Three NiTi rotary files (K3(TM), ProFile(R), and HERO 642(R)) with #30/.04 taper were evaluated. Each rotary file was divided into 2 subgroups: control (no surface defects) and experimental group (artificial surface defects). A total of six groups of each 10 were tested. The NiTi rotary files were rotated at 300rpm using the apparatus which simulated curved canal (40 degree of curvature) until they fracture. The number of cycles to fracture was calculated and the fractured surfaces were observed with a scanning electron microscope. The data were analyzed statistically. The results showed that experimental groups with surface defects had lower number of cycles to fracture than control group but there was only a statistical significance between control and experimental group in the K3(TM) (p<0.05). There was no strong correlation between the cross-sectional configuration area and fracture resistance under experimental conditions. Several of fractured files demonstrated characteristic patterns of brittle fracture consistent with the propagation of pre-existing cracks. This data indicate that surface defects of NiTi rotary files may significantly decrease fatigue life and it may be one possible factor for early fracture of NiTi rotary files in clinical practice.

Epidemiology of Klebsiella Isolates by Antimicrobial Resistance Gene Analysis

One hundred of clinical isolates of Klebsiella spp. from three hospitals were analyzed by phenotypic and genotypic characteristics for epidemiologic investigation. Almost all isolates of Klebsiella spp. showed highly resistance to ampicillin, and carbenicillin and 4.5-7.9% of K. pneumoniae isolates were also resistant to cefotaxime and ceftazidime, and 10-15% to aminoglycoside antibiotics except amikacin. However, all strains were highly susceptible to imipenem, cefotetan, amikacin and ciprofloxacin. All Koxytoca strains were susceptible to antimicrobials tested except Ap, Am and Cb. Twelve strains of K. pneumoniae hybridized with TEM or SHV probe and extended spectrum B-lactamases from 7 strains were TEM type. Eleven conjugative R plasmids and their parental strains were analyzed. Among them, three couples of plasmids showed identical or nearly identical resistance phenotypes of B-lactams and aminoglycosides, molecular weights, and pI values by isoelectric focusing, and hybridized fragment patterns with TEM probe by Southern hybridization, EcoR1 restriction endonuclease fragment patterns. Their parental strains were isolated from sputum, tissue, and ascites of patients and had similar characteristics. These results indicate that the epidemic strains or epidemic plasmids were present in this hospital and antimicrobial resistance anlysis can be used to discriminate clinical isolates of multi-resistant K. pneumoniae.

Cytogenetic Analysis of Chromosomal Abnormalities in Children

No abstract available.

The Hemodynamics and Electrocardiogram in Isolated Ventricular Septal Defect

No abstract available.

Abdaninal Tumor in Infants and Children

No abstract available.

A Case of Ehlers - Danlos Syndrome / 대한피부과학회지

We presented a case of Ehlers-Danlos syndrome(ED syndrome) in s 21-year- old male, who had hyperextensibility of skin, skin fragility, and cigarette paperlike atrophic scars with no joint problems since infancy. There was a family history which was suggestive of autosomal dominant trait. Microscopic examination of the skin biopsy specimen from the normal appearing skin on the right forearm showed no abnormal appearance. In this case the manifestations of skin including marked hyperextensibility might be in accord with type I (gravis) ED syndrome, but the joint manifestation did not correspond to this type. It might be hard to classify this case according to the eleven types of ED syndrome. Wed rather consider this case as a. mixed form of type I and type Il ED syndrome.

A Case of Gout / 대한피부과학회지

A 56-year- old man showed millet seed to egg sized, yellowish tender papules, subcutaneous mass on the both elbows, dorsa of both hands & feet, and lateral malleoli and helix of right ear for 6 years. the significant laboratory findings were leukocytosis, increased erythrocyte sedimentation rate, glycosuria, hyperuricemia and increased blood glucose level. X-ray findings of both hands & feet demonstrated gouty arthritic patterns. Histopathologic findings of the left lateral malleolar lesion revealed the typical patterns. Histopathologic findings of the left lateral malleolar lesion revealed the typical pattern of gout with needle-shaped urate crystal. Therapy was begun with colchicine & allopurinol but the patient died of renal failure three weeks after the start of therapy.

Three Cases of Idiopathic Calcinosis of the Scrotum / 대한피부과학회지

The idiopathic calcinosis of the scrotum which was first described by Shapiro et al. in 1970 is usually multiple, asymptomatic nodules of the scrotal skin and is easily misdiagnosed clinically as calcified epidermal inclusion cyst or pilar cyst. We present three cases of the idiopathic calcinosis of the scrotum. Clinically these three patients showed slightly yellowish papules or nodules in the scrotum without any other cutaneous disorders and subjective symptoms except mild itching sensation in one case. Histopathologically calcium deposits were found in the dermis without any evidence of residual cysts, and partial foreign body reaction was seen around the calcified area in one case. Laboratory findings including serum calcium, phosphorous and potassium level were within normal limits.

A Case of Cutis Marmorata Telangiectatica Congenits / 대한피부과학회지

Cutis marmorata telangiectatica congenita, which was first described by Van Lehuizen in 1922, is characterized by the presence at birth of a persistent cut;is marmorata pattern, phlebectasia, spider nevus-like telangiectasia, and areas of ulceration and steady improvernent with time. We reported a case of cutis mar.morata telangiectatica. congenita occuring in a 70 days old female infant showing the reticulated mottling and atrophy of the skin on the both lower extremites, right upper extremity, abdomen and buttock muscle weakening of right upper extremity and left lower extremity compare with the opposite side. Skin lesions were much improved during the observation period of 10 months without any other specific treatment except hermiatrophy of right upper extremity.