Melanogenesis, or synthesis of melanin has been a focus of intense investigation by pigment cell biologists during the past few decades. Melanogenesis provides pigment in skin, thus serving as a unique, if not only, physiological defense against sun-induced injuries, including photocarcinogenesis. Moreover, skin color plays a major role in visual esthetics of an individual. Therefore, unwanted hyper- or hypo-pigmentation, especially on facial skin, could cause significant psychological stress. Epidermal melanocytes, derived from neural crest cells, are mainly responsible for melanin in skin. In human skin, nearly all normal pigmentation is due to melanin and with the exception of hemoglobin, it is one of the only endogenously synthesized pigments in man. Melanin has numerous functions in mammals, including increasing the optical efficiency of the eye, producing color patterns in various organs, including hair or skin, serving as camouflage, heat exchange, sexual recognition and protection from sunlight. The incidences of malignant melanoma have been increasing dramatically in western countries, at least by a factor of 15 over the past 60 years, and this has caused an intense interest in understanding melanogenesis. More than 40,000 new cases of malignant melanoma have been diagnosed in 1997, and it is one of the most common cancers in young adults. The research in the area of melanogenesis has exploded during the last ten years because model systems to study molecular mechanisms regulating melanogenesis have become available. This review examines currently available in vitro and in vivo model systems to study melanogenesis.
Esthetics ; Hair ; Hot Temperature ; Humans ; Incidence ; Mammals ; Melanins ; Melanocytes ; Melanoma ; Neural Crest ; Pigmentation ; Skin ; Stress, Psychological ; Young Adult

To assess the effects of regional wall motion abnormalities on left ventricular function, mitral annulus(MA) motion and left ventricular posteior wall(LVPW) motion were studied by M-mode and Doppler echocardiography in 13 normal subjects and 40 mitral valve replaced(MVR) patients. In MVR patients, mitral annulus motion showed significantly delayed contraction(DC) after A2 by 3.7+/-3.0mm in amplitude and 80+/-35 msec in time(normal control; 0.1+/-0.3mm, 35+/-15msec, p<0.01 for both) and reduction in systolic % thickening of LVPW(39.7+/-23.6 VS 63.2+/-18.4%, p<0.01). MVR patients were devied into 2 group according to the amplitude of MA motion, 4mm Group I(n=13, DC> or =4mm) showed increase epicardial excursion of LVPW compared with Group II(n=27, DC<4mm)(Group I vs Group II, 11+/-3.7 vs 8.6+/-2.6 mm, p<0.05). In mechanical prosthetic valve replaced patients(n=22), time relationship between valve opening, mitral flow, peak thining rate of LVPW and valve peak excursion were studied also and the phase difference that are observed in normal subjects, were lost. We interpreted these delayed contraction of mitral annulus motion and epicardial motion increment as muscle fiber architectural abnormalities which might effect on MVR patients as a factor of left ventricular systolic and diastolic dysfunction.
Echocardiography, Doppler ; Humans ; Mitral Valve* ; Ventricular Function, Left

Clinical characteristics and coronary angiographic findings were analyzed in 24 patients with angiographically documented coronary artery spasm, which developed spontaneously in 11 cases and was provoked by intravenous ergonovine meleate in 13 cases. The commonest clinical presentation was chest pain at rest in 21 out of 24 cases, and nine patients with resting angina had also exertional chest pain. Ten patients complained of chest pain which developed especially at night and in the early morning. Cumulative doses of ergonovine meleate whoch were required to provoked spasm were 0.05mg in 3, 0.15mg in 8 and 0.35mg in 2 cases. Transient hypertension occured in one case as a complication of ergonovine provocation test. In 20 cases coronary artery spasm developed at the portion of normal or insignificantly narrowed coronary arteries, at the severely stenotic portion in 3 cases and at the normal portion different fropm severe tight lesion in one case. Electrocardiographic findings at the time of coronary spasm were ST segment elevation in 11 among 18 cases, ST segment depression in 2 cases and no change in 3 cases. Twenty two patients complained of chest pain of the same characteristics which they had previously experienced, but there was no chest pain in 2 patients. Right coronary artery was the most prevalent site of coronary artery spasm, and percutaneous transluminal coronary angioplasties were performes successfully in 4 cases with significantly tight lesions. In conclusion coronary artery spasm is thought to play a significant role in the conversion of stable to unstable angina and the development of silent myocardial ischemia as well as variant angina.
Angina, Unstable ; Angioplasty ; Chest Pain ; Coronary Artery Disease* ; Coronary Vessels* ; Depression ; Electrocardiography ; Ergonovine ; Humans ; Hypertension ; Myocardial Ischemia ; Spasm*

Serum levels of HDL-cholesterol, triglyceride and total cholesterol were measured in 107 normal Koreans and in 327 patients; 66 patients with hypertension, 34 patients with coronary heart disease, 45 patients with cerebral thrombosis, 18 patients with nephrotic syndrome, and 164 patients with diabetes mellitus. Patterns of serum lipoprotein fractions were also investigated by agarose gel electrophoresis in 41 normal Koreans and in 72 patients; 14 patients with hypertension, 10 patients with coronary heart disease, 19 patients with cerebral thrombosis, 7 patients with nephrotic syndrome, and 22 patients with diaebetes mellitus. The results are summarized as follows; 1. Mean values of serum HDL-cholesterol, triglyceride and cholesterol in normal Koreans were 52.2+/-12.4mg/100ml, 110.6+/-31.6mg/100ml and 175.3+/-21.4mg/100ml respectively. No significant difference in mean value of serum HDL-cholesterol was observed between Korean males and females. 2. In Korean females serum, HDL-cholesterol level showed peak values in the fifth decade, but no significant difference with aging was observed in Korean males. 3. Serum HDL-cholesterol levels were significantly decreased in patients with hypertension, coronary heart disease, cerebral thrombosis, and in male diabetic patients with complication. 4. Serum triglyceride levels were significantly increased in all the disease groups, and serum cholesterol levels were significantly increased in all the disease groups except cerebral thrombosis. 5. Mean values of alpha-lipoprotein, pre-beta-lipoprotein and beta-lipoprotein fraction ratios in normal Koreans were 28.9+/-7.5%, 14.9+/-4.9% and 56.2+/-8.1% respectively. 6. Seum alpha-lipoprotein fraction ratio was significantly decreased in relatively advanced hypertensive patients. Pre-beta-lipoprotein fraction ratio tends to be increased in patients with hypertension, cerebral thrombosis, nephrotic syndrome and in diabetic patients with complications, and beta-lipoprotein fraction ratio tends to be increased in patients with hypertension, coronary heart disease and nephrotic syndrome, but those were not statistically significant.
Aging ; Cardiovascular Diseases* ; Cholesterol ; Coronary Disease ; Diabetes Mellitus ; Electrophoresis, Agar Gel ; Female ; Humans ; Hypertension ; Intracranial Thrombosis ; Lipoproteins ; Male ; Nephrotic Syndrome ; Triglycerides

An epidemiologic investigation was conducted to identify the source of infection and the mode of transmission of typhoid fever outbreak occurred in Ohchun middle and high schools located in Young il Gun, Kyungpook Province from May 21 to Jun 4, 1994. Four out of 13 hospitalized students in three general hospitals in Pohang City were culture positive typhoid fever (Salmonella typhi Group D). Review of the in and outpatient logbooks of the three general hospitals in Pohang City, county health center and local clinics in the vicinity of the Ohchun middle and high schools suggested that the outbreak was confined to the schools. Drinking water source of the schools was two underground water pumps that had no treatment facilities; one in northern end and the other in southern end of the main school building. However, the southern water pump was closed on April 28, 1994 because a recent test for the water revealed E-coli suggesting a possible fecal contamination. Two hundred twenty students stated that they had experienced symptoms related to typhoid fever since April l, 1994 in a self administered questionaire survey of all of the 2, 226 students. Personal interviews with these 220 students were performed to confirm the clinical history together with a rectal swab culture for typhoid fever and Widal test. A total of 39 patients were detected; 15 confirmed cases (culture-positive) and 24 suspected cases (symptom positive with equal to or greater than 1:160 titer of Salmonella O-antibody or 1:320 titer of H-antibody titer in Widal test). The epidemic curve showed a unimodal curve with a peak on the second week(17 May, 1994) and tailed down to the 5th week (22 28 May, 1994). The overall incidence rate of typhoid fever was 1.8 per 100 students; 1.5 (1.6 for male, 1.5 for female) in the middle school and 2. 4 (6. 2 for male, 0. 4 for female) in the high school. When contrasted with the students who did not drink water at all in the school, the relative risks of incidence rate of typhoid fever for the students who drank the underground water of the school, both underground water and water brought from home, or water brought from home only were 55.5, 19.0, and 3.0 respectively. Three classes which had especially high incidence rates of typhoid fever were located in the southern part of the main school building, where the contaminated underground water pump is located. These findings suggested that the source of infection was the contaminated underground water of the school. Both of the two underground water pumps were closed permanently and the public running water was supplied to the schools.
Drinking Water ; Groundwater ; Gyeongsangbuk-do* ; Hospitals, General ; Humans ; Incidence ; Male ; Outpatients ; Running ; Salmonella ; Typhoid Fever* ; Water

Echocardiographic right ventricular systolic time invervals were measured in 69 cases of congenital and acquired valvular heart disease, who have neither arrhythmia nor conduction disturbances. The results were as follows: 1) Right ventricular preejection periord(RVPEP) relates with main pulmonary arterial systolic pressure (MPA(s)), main pulmonary arterial diastolic pressure (MPA(d)), main pulmonary arterial mean pressure (MPA(m)), pulmonary vascular resistance (Rp), and the ratio of pulmonary systemic vascular resistance (Rp/Rs) (r=0.746, 0.738, 0.755, 0.721, 0.687). 2) Rifht ventricular ejection time relates with MPA (s), MPA (d), MPA (m), Rp, and Rp/Rs (r=-0.580, -0.541, -0.544, -0.577, -0.420). 3) The ratio of right ventricular preejection period-right ventricular ejection time (RVPEP/RVET) relates with MPA (s), MPA (d), MPA (m), Rp and Rp/Rs (r=0.789, 0.784, 0.781, 0.778, 0.695). 4) Pulmonary hypertension and increased pulmonary vascular resistance can be predicted, when RVPEP/RVET is over 0.3. 5) By serial preoperative and postoperative measurements, pulmonary hypertension and increased pulmonary vascular resistance were relieved in the cases of mitral stenosis. But in the cases of congenital heart diseas there were no significant change in RVPEP/RVET ratio.
Adult* ; Arrhythmias, Cardiac ; Blood Pressure ; Echocardiography* ; Heart ; Heart Valve Diseases ; Humans ; Hypertension, Pulmonary ; Mitral Valve Stenosis ; Systole* ; Vascular Resistance

The Enchondroma is a benign cartilage forming harmartoma arising chiefly from short tubular bones on hands and feet. If on a long tubular bone or flat bone such as femur or ilium, it is most likely to be a true neoplasm such as chondrosarcoma, not a harmartoma. A case of enchondroma was reported. It occurred over right ischium of 19 years old male and was found incidentally by roentgenogram. The lesion was biopsied and diagnos's was confirmed by histologic examination. It was treated by curretage with filling of cavity with bone chips. Post operative-course was uneventful.
Cartilage ; Chondroma ; Chondrosarcoma ; Femur ; Foot ; Hand ; Humans ; Ilium ; Ischium ; Male

With increasing tendency of incidence and interest for the late onset schzophrenia, concerns about whether this disorder is etiologically or phenomenogically distinctive entity or not have increased also. To clarify the disease entity of the late onset schzophrenia and the role of structural brain changes in its etiology, authors tried to prove following hypothesis : Are there any evidences of structural brain changes in the late-onset schizophrenia? ; If present, are they not different from those of the early-onset schizophrenia or progressive schizophrenia? ; And are they not different from those of senile dementia? Subjects were 6 patients with the late-onset schizophrenia, 6 patients with the early-onset schizophrenia, 6 patients with progressive schizophrenia, 6 patients with Alzheimer's dementia, and 6 controls. We measured regions of interest of the magnetic resonance images by computer assisted planimetry using the AutoCad and digitizer. Our study results may suggest that the third ventricular enlargement and a reversal of normal difference between left and right temporal lobe and left-right difference in posterior lateral ventricle are common brain pathology for all type of schizophrenia including the late onset schzophrenia. And also suggest that brain structural changes of the late onset schizophrenia are related with neurodevelopmental abnormality rather than degenerative change.
Alzheimer Disease* ; Brain Diseases ; Brain* ; Dementia ; Humans ; Incidence ; Lateral Ventricles ; Magnetic Resonance Imaging* ; Schizophrenia* ; Temporal Lobe

The heart, 500g in weight, with subacute myocarditis associated with granulomatous myocarditis may be a good model for the study on the pathophysiologic mechanism of cardiac failure. Furthermore, the clinical data of this case is enough to clarify his all clinical course from admission to death due to cardiac failure. So, we analyzed the clinical data, histologic findings, and morphometric pattern of histologically intact myocardial cells and inflammatory reaction to investigate the pathophysiologic mechanism of the cardiac failure. The results were summarized as follows. 1. Clinically, the heart showed cardiac failure of diastolic phase and abnormal conduction system related to sudden cardiac death. However, it might be adapted to the relatively stable wital signs due to pericardial positive pressure by slowlyprogressed pericardial effusion. 2. The distribution pattern of area of intact myocardial cell area and inflammtion reaction showed relatively even spread of inflammatory reaction and extremely decreased area of myocardial cells to about 21% of total heart. So, its contractility might be decreased below to the 21% of the normal cardiac contractility. 3. The mechanism of the cardiac failure in myocarditis may be sudden inflammatory involvement of conduction system and/or extremely decreased myocardial cell volume due to inflammatory destruction. 4. Morphometric analysis may be a useful objective method to grading the severity of old and recent form of myocarditis. From the above results, the cardiac failure of myocarditis is influenced by the adaptability at the inflammatory abnormality of the conduction system, contractility of injured myocardial cells, and compensation activity of pericardial effusion.
Cell Size ; Compensation and Redress ; Death, Sudden, Cardiac ; Heart ; Heart Failure* ; Myocarditis* ; Pericardial Effusion

Authors analysed systolic pressure-volume-stress relations by combined echo-pressure-cineangiographic measurement in 10 normal subjects(Group I) and 37 patients with chronic valvular heart diseases. Patients with chronic valvular heart diseases were divided into 3 groups : Group II ; mitral stenosis(n=9), Group III ; mitral stenosis with aortic regurgitation(n=19). The aims of this study are to find useful left ventricular(LV) contractility indices and evaluate left ventricular contractility at various volume loading states. Studied LV contractility indices were maximal elastance of isovolumic contraction(Eiso), endsystolic pressure-volume ratio(Ees) and slope of regression line in late systolic stress-volume loop(A). Eiso was estimated using an isovolumic contraction model of Sunagawa and A was analysed in a single ejecting beat. Endsystolic volume index(ESVI), end diastolic volume index(EDVI), stress at peak pressure(Speak), cardiac index, Vmax, mean Vcf and ejection fraction were determined also. The obtained results were as follows. 1) Significant correlations were found in whole group(n=47) between Eiso and Ees(r=0.88, P<0.005), Elso and cardiac index(r=0.83, P<0.005), Ees and CI(r=<0.76, p<0.005). Further, these correlation coefficiencies were not different between any two groups of Group I, Group II, Group III, Grouop IV and whole group (p<0.05); that is Eiso or Ees had a constant significance at various loading state. 2) Significant correlation between A and cardiac index was noted in Group I+II+III(n=28, r=0.48, p<0.01), but this correlation coefficiency was significantly different from that of Group IV(n=19, r=0.08); p<0.05. 3) In Group II(patients with mitral stenosis), cardiac index* and EDVI* and stress at peak pressure** were decreased significantly(*:p<0.05, **:p<0.005). But Eiso, Ees, A and all the other idices were not decreased. These findings suggested that left ventricular contractility is not reduced in mitral stenosis. 4) In Group IV(patients with amitral regurgitation with or without aortic regurgitation), **EDVI and ESVI** were increased while Eiso**, Ees, Vmax*, mean Vcf* and cardiac index** were decreased significantly. But ejection fraction and A were not decrease. These findings suggested that ejection fraction and A may not be decreased at volume overload, despite of impaired left ventricular contractility. In summary; Eiso or Ees was evaluated as an useful contractility index which appeared not to be influenced by various volume loading state, while eiection fraction and A to be influenced. Patients with mitral stenosis as a group have reduced cardiac performance which is not due to impairment of left ventricular contractility(muscle function) but to reduced preload.
Constriction, Pathologic ; Heart Valve Diseases* ; Humans ; Mitral Valve Stenosis