[Etiopathogenic importance of human herpes viruses type 6, 7 and 8 in manifestations of certain skin diseases]. / Etiopatogenetski znacaj humanih herpes virusa tip 6, 7 i 8 u pojavi nekih oboljenja koze.

INTRODUCTION: In the past few years new human herpes viruses (HHV): HHV-6, -7 and -8 have been discovered. According to the most recent literature, they might have an important role in etiopathogenesis of some dermatological diseases. HUMAN HERPESVIRUS 6: HHV-6 was isolated in 1984 from peripheral blood lymphocytes of AIDS patients and patients with different lymphoproliferative diseases. Up to now, two variants of this virus have been identified, A and B, which differ in genetic, biological and immunological characteristics. The etiological importance of variant A, has not yet been clarified, while variant B is considered to be the major cause of many diseases, such as exanthema subitum in infants. In many cases primary infection is associated with elevated temperature, without rash. HUMAN HERPESVIRUS 7: HHV-7 was isolated in 1990 from activated peripheral blood CD4+ T cells of healthy persons. The virus is ubiquitous and more than 80% of babies and infants are affected. Presence of DNA sequences of this virus in mononuclear cells of peripheral blood, skin and plasma of pityriasis rosea patients, points to possible connection between this illness and HHV-7 infection. HUMAN HERPESVIRUS 8: HHV-8 was first identified in tissue samples of patients with Kaposi's sarcoma associated with AIDS in 1994. DNA virus sequences were also isolated in HIV negative persons with Kaposis's sarcoma. Presence of virus can be established in mononuclear cells of peripheral blood, endothelial cells that cover vascular spaces and spindle cells within skin changes. Modes of transmission are still not clarified. However, HHV-8 was identified in some other dermatological diseases as well.

[What do we know today about diaminodiphenylsulfone?]. / Sta danas znamo o diaminodifenilsulfonu?

INTRODUCTION: Diaminodiphenylsulfone or dapsone is a chemical analogue of sulfapyridine, synthesized in 1908. Dapsone is a bacteriostatic agent that proved to be efficient in treating leprosy and malaria, but today it is used in treating dermatologic noninfectious inflammatory diseases. PHARMACOLOGY: Dapsone is orally used in a dose of 50-400 mg per day in treatment of dermatologic diseases, and also in a dose of 50-100 mg per day in leprosy treatment. Dapsone is mainly eliminated from the body by urine and smaller part by faeces. Pharmacological interaction was reported when it is used with rifampicin and probenecid. MECHANISM OF ACTION: The bacteriostatic effect of dapsone is well known. It involves inhibition of folic acid synthesis in susceptible organisms. The anti-inflammatory effect of dapsone, which proves to be efficient in treating noninfectious inflammatory diseases, has not been explained completely yet. There are some pieces of evidence that anti-inflammatory action is not connected with its antibacteriological action. CLINICAL USE: Based on previous studies about therapy efficiency of dapsone in treating some diseases, there are two groups of diseases: the group responding well to dapsone (leprosy, malaria, DH, linear IgA-dermatosis, erythema elevatum diutinum, bullous systemic lupus erythematosus) and a group responding with average good response to dapsone (pyoderma gangrenosum, bullous and cicatricial pemphigoid, acne conglobata, discoid cutaneous lupus erythematosus, subcorneal pustulosis dermatosis, granuloma faciale, rheumatoid arthritis, polychondritis, leucocytoclastic vasculitis). ADVERSE EFFECTS: Adverse effects depend on the dose and they rarely occur at doses less than 100 mg per day. They are mainly shown on skin, nervous system, digestive system, hepatobiliary system, and kidney and hematologic system. The most important adverse effects are hemolytic anaemia and methemoglobinemia. Hemolysis usually occurs at doses of 200 mg and more per day. In patients with glucose-6-phosphate dehydrogenase deficiency, hemolysis may be provoked by a dose less than 50 mg per day. For prevention, before using dapsone in therapy, clinical examination with history, blood parameters, liver and renal parameters and determination of glucose-6-phosphate dehydrogenase level are recommended. CONCLUSION: The use of dapsone is absolutely indicated in DH treatment and erythema elevatum diutinum. Because of anti-inflammatory effects, dapsone can also be used in treating other inflammatory noninfectious dermatoses when one should take care about "therapy efficiency/adverse effect" balance using the correct dose, monitoring relevant clinical and laboratory parameters and educating patients.

The "b" mutated gene in heterozygous Belgrade anemic rat.

The Belgrade b/b rat has an autosomal recessive mutation which in homozygous state induces severe anemia. So far, this mutation has been considered a recessive one and the heterozygous animals (+/b) as phenotypically normal. In this study, we showed that at the hematologic level, the heterozygous animals acquire some of the anemic characteristics as well. Namely, the young +/b animal displays reticulocytosis of 3.1 +/- 1.0%, identical to b/b rat, compared with 0.8 +/- 0.4% in young normal animals. This conclusion was further supported by examination of beta-globin expression. The level of beta-globin mRNA in anemic and heterozygous reticulocytes is decreased, as estimated by dot blot hybridization, to 25% and 50% of normal level, respectively. Although inapparent phenotypically, b mutated allele disturbs early erythropoiesis and markedly decreases globin mRNA level in the heterozygous rat.