Inability of murine melanoma melanosomal "tyrosinase" (L-dopa oxidase) to oxidize tyrosine to melanin in polyacrylamide gel systems.

Melanosomal "tyrosinase" (L-dopa) was isolated from trypsin digest of B-16 mouse melanoma melanosomes, using polyacrylamide gel disc electrophoresis. The enzyme was represented by a single band, having characteristics similar to the T1 dopa-positive band observed when using supernatants of crude melanoma homogenates as the source. When gels with this band were incubated in solutions containing tyrosine and dopa in varying ratios , there was no enhancement of melanin formation by tyrosine when compared with incubations in corresponding concentrations of dopa alone. These data further support previous studies in our laboratory demonstrating an inability of so-called mamalian "tyrosinase" to convert tyrosine to melanin; since this enzyme readily converts L-dopa to melanin, it seems more reasonable to term this enzyme an L-dopa oxidase.

Epidemiology of liver cirrhosis morbidity and mortality in Iceland.

BACKGROUND: The mortality from liver cirrhosis in Iceland is the lowest in the Western world. OBJECTIVE: To study the epidemiology of liver cirrhosis mortality and morbidity in Iceland and to obtain a reliable separation between alcoholic cirrhosis (AC) and non-alcoholic cirrhosis (NAC) by using multiple data sources. METHODS: The study included the whole population of Iceland. Mortality was studied through death certificate data for the period 1951-90 and morbidity (clinical incidence) through hospital, autopsy and biopsy records for the period 1971-90. RESULTS: The average mortality for AC in age group 20 years and older was 8.6 and for NAC 19.2 per 10(6)/year and the average clinical incidence was 22.1 per 10(6)/year for AC and 25.9 per 10(6)/year for NAC. In the morbidity study 44% of cases were due to AC. In the mortality study 24% of cases were due to AC but the data suggested an underreporting of AC for males at a rate of 30%. There was a significant decrease in AC mortality with time but no change in NAC. Average alcohol consumption of inhabitants aged over 15 years increased from 2.1 to 4.9 litres per year (130%) during the period 1951-90. CONCLUSION: The incidence of cirrhosis in Iceland is very low for both AC and NAC, accounting for only 0.2% of total deaths. The reasons are unknown. The low incidence of AC in Iceland is probably partly due to low alcohol consumption. The decreasing incidence of AC despite 130% increase in alcohol consumption is thought to be due to intensive treatment of alcoholism. A low prevalence of hepatitis B and C probably contributes to the low incidence of NAC.

[Ischemic colitis in young adults.].

INTRODUCTION: Ischemic colitis is most often considered a disease of the elderly with associated cardiovascular disease. Young patients with this disease have been diagnosed at our hospital and therefore the authors decided to investigate the disease's prevalence, its anatomical location, prognosis and risk factors in the young population. MATERIAL AND METHODS: A retrospective search of all cases diagnosed as ischemic colitis from 01.01. 1983 to 31.12. 1995 was performed. One author (ThornThorn) reviewed all pathological material. Strong inclusion criteria were proposed and of the 50 cases discovered, only 26 fulfilled these strict criteria, 16 women and 10 men. Five were under the age of 40 (19%), three of them men. RESULTS: Ischemia was most common in the left colon. Incidence has increased in the last years, paralelling the increase in colonoscopies performed. All patients under 40 years of age had completely reversible ischemia, however eight of 21 patients over the age of 60 required surgical intervention. Five patients died and were all older than 75 years. The percentage of young patients is noteworthy. CONCLUSION: Pathophysiology of ischemic colitis in young people is in most cases unknown. Possible contributing factors in our study were smoking, dehydration, NSAID (non-steroidal anti-inflammatory drugs) use, constipation and contraceptive use. The study supports the importance of early endoscopy and biopsies for diagnosis in patients presenting acutely with symptoms of hemorrhagic colitis.

[Pneumatosis coli - A case from the department of obstetrics and gyneocology.].

UNLABELLED: A 36 year old woman, pregnant 41 weeks and two days was admitted to the hospital in labour. The course was slow, foetal distress was seen with foetal heart monitoring. Cesarean section was performed and a healthy boy delivered. Three days later she developed abdominal pain and passed extensive flatus. Fever was 39 degrees C rectally. Abdominal x-ray showed signs of mechanical ileus and laparotomy was performed. Appendix was swollen and therefore removed. Post operatively the woman developed massive diarrhea. Acute colonoscopy showed air-filled vesicles in distal colon, macroscopically diagnosed as pneumatosis coli. The treatment was 50% oxygen initially but was increased to 70% because of slow improvement. P02 was kept at 250-300 Hg and colonoscopy on the 24th day showed almost full recovery. DISCUSSION: Pneumatosis cystoides intestinalis is a rare, benign disease, characterized by subserosal/ submucosal vesicles, varying in size and number. Aetiology is unknown but it has been associated with some gastrointestinal diseases, abdominal surgery, and lung diseases. The pathology is unknown but three main theories exist. Symptoms can be abdominal pain, diarrhea, flatus and rectal bleeding. Diagnosis is by x-ray, CT scan or colonoscopy. Treatment is high oxygen doses for one to two weeks but if another disease is underlying surgery might be needed. The prognosis is good but a certain chance of relapse exists.

[Cure after re-resection of colorectal liver metastases in a 28 year old woman. A case report.].

Liver resection is the only well documented curative treatment for colorectal liver metastases but without surgery survival is dismal. Liver resections can be done for re-metastatic colorectal cancers if the tumors are localized in the liver. The first case of re-resection of colorectal liver metastases in Iceland is presented.

[A nationwide epidemiological study on celiac disease - the Icelandic picture.].

UNLABELLED: We undertook an epidemiological study of celiac disease (CD) in Iceland for the period 1962-1991. Twenty-eight patients, two of whom were children met the criteria for inclusion. The median age at diagnosis was 34 years, and the female:male ratio was 3:1. The majority of patients, 24 (86%), were diagnosed during the last of three decades studied. The annual incidence rate during the most recent 10-year period was 1:100,000. The point prevalence at the end of 1991 was 1:9,600. The incidence for children was 0.016:1000. The patients' geographical distribution within Iceland was uneven, with an unexpected preponderance of patients living in the country's north-eastern region. These apparent differences in topographical distribution may represent thoroughness in identification of patients rather than actual regional differences in frequency of the disease. The clinical features of CD are similar to those previously reported. Retrospectively analysed, the mean diagnostic delay was 16 years. The utility rate of small bowel biopsies in patients suspected of CD was low, 0.028 in adults and 0.013 in children. CONCLUSION: Celiac disease is far less prevalent in Iceland, especially among children, than elsewhere in north-western Europe. The incidence of CD has, however, risen markedly in recent years.

Native-valve endocarditis due to Neisseria sicca: case report and review.

Many species of the Neisseria, gram-negative diplococci that are frequent respiratory commensals in humans, have been regarded as being nonpathogenic or as causing disease in only immunocompromised hosts; in contrast, gram-negative diplococci such as Neisseria meningitidis and Neisseria gonorrhoeae are known pathogens. We report a case in which Neisseria sicca was the cause of serious infection (with catastrophic consequences) in an immunocompetent patient and review the world literature on endocarditis due to N. sicca.

[Epidemiology of liver cirrhosis morbitity and mortality in Iceland.].

BACKGROUND: The mortality from liver cirrhosis in Iceland is the lowest in the Western world. OBJECTIVE: To study the epidemiology of liver cirrhosis mortality and morbitity in Iceland and to obtain a reliable separation between alcoholic cirrhosis (AC) and non alcoholic cirrhosis (NAC) by using multiple data sources. METHODS: The study included the whole population of Iceland. Mortality was studied through death certificate data for the period 1951-1990 and morbidity (clinical incidence) through hospital, autopsy and biopsy records for the period 1971-1990. RESULTS: 1) The average mortality for AC in age group 20 years and older was 8.6 and for NAC 19.2 per 106 per year and the average clinical incidence was 22.1 for AC and 25.9 for NAC. 2) In the morbitity study 44% were due to AC. In the mortality study 24% were due to AC but the data suggested an underreporting of AC for males at a rate of 30%. 3) There was a significant decrease in AC mortality with time but no change in NAC. 4) Alcohol consumption per inhabitant over 15 years increased from 2.1 to 4.9 litre (130%) during the period 1951-1990. CONCLUSION: The incidence of cirrhosis in Iceland is very low for both AC and NAC accounting for only 0.2% of total deaths. The reasons are unknown. The low incidence of AC in Iceland is probably partly due to a low population alcohol consumption. The decreasing incidence of AC despite 130% increase in alcohol consumption is thought to be due to intensive treatment of alcoholism. A low prevalence of hepatitis B and C probably contributes to the low incidence of NAC.

Peroxidatic oxidation of tyrosine to melanin in supernatant of crude mouse melanoma homogenates.

Peroxide-dependent enzymic oxidation of tyrosine to dopachrome and melanin was demonstrated in cell-free melanoma homogenates. Histochemical methods for distinguishing peroxidase activity from aerobic dopa (3,4-dihydroxyphenylalanine) oxidase activity are not reliable with cell-free preparations. Therefore the presence of peroxidase activity in such preparations precludes assay of cresolase activity of mammalian ;tyrosinase'.

The association between coeliac disease, dermatitis herpetiformis and certain HLA-antigens in Icelanders.

Twenty-eight cases of coeliac disease (CD) and seven of dermatitis herpetiformis (DH) have been verified in Iceland. Standard serological techniques were used for HLA typing. Twenty-five individuals with CD were typed, 21 (84%) of whom carried DR3,DQ2. Twelve of these 25 (48%) had DR3,DR7, DQ2, which makes them possibly homozygous for DQ2, and suggests that homozygosity of DQ2 increases the risk for CD. The four DH patients that were typed all had HLA-B8,DR3,DQ2. It is concluded that CD and DH are associated with DR3, DQZ in Icelanders.