Epidemiology and risk factors of uric acid urolithiasis

Prevalencija uratnih kamenaca je u porastu, osobito u razvijenim zemljama, a kao rizični čimbenici u patogenezi smatraju se genetska predispozicija, nizak pH urina, mali urinarni volumen i hiperurikozurija. Kronični proljevi, mijeloproliferativne bolesti, inzulinska rezistencija, bubrežno zatajenje, razni metabolički poremećaji, konzumacija alkoholnih pića i neki lijekovi imaju važnu ulogu u patogenezi uratne urolitijaze.The prevalence of uric acid urolithiasis is increasing, especially in developing countries and risk factors involved in the pathogenesis are genetic predisposition, low urinary pH, low urinary volume and hyperuricosuria. Chronic diarrheal states, myeloproliferative disorders, insulin resistance, renal insufficiency, various metabolic disorders, consumption of alcohol drinks and some medications have an important role in the pathogenesis of uric acid nephrolithiasis

Pathophysiology of gout

Hiperuricemija je jedan od češćih metaboličkih poremećaja u općoj populaciji, a uglavnom je posljedica više čimbenika kao što su prehrana s visokim udjelom purina, konzumacija alkohola, primjena diuretske terapije i smanjenog bubrežnog klirensa. Kada se prekorače lokalne granice topljivosti mokraćne kiseline, dolazi do odlaganja kristala mononatrijeva urata u zglobovima, bubrezima i mekim tkivima uzrokujući kliničke manifestacije, kao što je urični artritis, odlaganje u mekim tkivima (npr. tofi), razvoj bubrežnih kamenaca te uratna nefropatija. U patogenezi hiperuricemije i uričnog artritisa ulogu imaju genetski polimorfizmi transportera za urate u bubrezima te aktivacija imunološkog sustava i stvaranje citokina što će biti detaljnije razjašnjeno u ovom radu.Hyperuricemia is rather often metabolic disorder in general population. It is multifactorial disorder influenced by purine rich diet, alcohol consumption, diuretics use and renal deterioration. In the presence of local urate superasturation and lower solubility, monosodium crystals are deposited in joints, kidneys and soft tissue leading to clinical manifestations, such as gout, tophaceus deposits, nephrolithiasis and uric nephropathy. Major advances in understanding the pathogenesis of hyperuricemia and gout have been made recently, including genetic studies of urate transporters in kidneys as well as innate immune inflammatory responses and cytokine production which will be discussed thoroughly in this paper

Merkel Cell Carcinoma: Case Report

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine carcinoma of the skin. Although it is 40 times less common than malignant melanoma, its mortality is much higher compared to melanoma. From 1986 to 2001 there was rapidly increasing incidence in reported cases of MCC, with a tripling in the rate over this 15-year period. The vast majority of MCC presents on sun-exposed skin. The head and neck area is the most common site of tumor occurrence. We present 70-year old female patient with painless red-colored nodule, size 2x2x2 cm on the dorsal side of mid left forearm. The surgical excision with negative margins was performed, and pathohistological analysis confirmed Merkel cell carcinoma. Sentinel lymph node biopsy was negative. In conclusion, as MCC is a very aggressive rare skin carcinoma with lethal outcome, it should be mandatory to perform biopsies of any suspected skin lesion

Possibilities of use bioelectrical impedance analysis as measuring technique in prevention of osteoporosis

Background and Purpose: Bioelectrical impendance analysis (BIA) and dual energy X-ray absorptiometry (DXA) are the two most common methods used for body composition analysis. The aim of this study was to investigate if there is a correlation between results of body analysis by BIA and results of DXA measurements at usual sites for diagnosis of osteoporosis. If the correlation is found than it could mean that BIA might be used to point the need for extra DXA measurements, and earlier diagnosis of osteoporosis. Material and Methods: 27 young adults (11 males and 16 females) aged 19-23 years were measured by BIA instrument for body composition analysis, and by DXA instrument for BMD and BMC at the L1-L4 vertebrae of the lumbar spine postanteriorly and the proximal femur („hip”). Correlation coefficients were calculated to examine linear relationship of results of two methods. Results: Mineral content obtained by BIA correlates with BMC (result of DXA) at all three measured sites. When analyzed by sex, correlation was found only among female subjects, while in males there was no correlation. Correlation of other results of BIA and BMD or BMC (DXA) showed similar situation. T-scores correlated positively with results of BIA within the female subgroup of the sample. Conclusions: According to obtained results we cannot conclude that results of BIA body composition analysis could be indicative for problems in bone metabolism, or state of bone density and bone mineral content, although some correlations are present

Osteoprotegerin and Vascular Calcification: Clinical and Prognostic Relevance

Osteoprotegerin ( OPG ) is a key regulator in bone metabolism, that also has effect in vascular system. Studies suggest that osteoprotegerin is a critical arterial calcification inhibitor, and is released by endothelial cells as a protective mechanism for their survival in certain pathological conditions, such as diabetes mellitus, chronic kidney disease, and other metabolic disorders. That has been shown in studies in vitro and in animal models. The discovery that OPG deficient mice (OPG-/- mice) develop severe osteoporosis and arterial calcification, has led to conclusion that osteoprotegerin might be mulecule linking vascular and bone system. Paradoxically however, clinical trials have shown recently that OPG serum levels is increased in coronary artery disease and correlates with its severity, ischemic cardial decompensation, and future cardiovascular events. Therefore it is possible that osteoprotegerin could have a new function as a potential biomarker in early identification and monitoring patients with cardiovascular disease. Amongst that osteoprotegerin is in association with well known atherosclerosis risc factors: undoubtedly it is proven its relationship with age, smoking and diabetes mellitus. There is evidence regarding presence of hyperlipoproteinemia and increased serum levels of osteoprotegerin. Also the researches have been directed in genetic level, linking certain single nucleotid genetic polymorphisms of osteoprotegerin and vascular calcification appearance. This review emphasises multifactorial role of OPG, presenting numerous clinical and experimental stydies regarding its role in vascular pathology, suggesting a novel biomarker in cardiovascular diseases, showing latest conclusions about this interesting topic that needs to be further explored

Pathophysiology of osteoporosis

Ravnoteža razgradnje i stvaranja kosti važna je za normalan proces pregradnje i održavanja koštane mase. Genetski, hormonski, imunološki i drugi čimbenici utječu na pregradnju kosti tijekom cijelog života. Poremećaj koštane pregradnje ključni je patofiziološki mehanizam nastanka osteoporoze i predstavlja složen proces u kojem sudjeluju koštane stanice, citokini i njihovi receptori. Danas je već poznata važna uloga RANK/RANKL/OPG sustava u patofiziologiji osteoporoze, ali se i dalje istražuju važni unutarstanični signalni putovi u nastanku osteoporoze i drugih metaboličkih bolesti kosti.The balance of degradation and bone formation is important for the normal process of remodeling and maintenance of bone mass. Genetic, hormonal, immunological and other factors affect bone remodeling throughout life. Disorder of bone turnover plays key role in the pathophysiology of osteoporosis and presents a complex process which involves bone cells, cytokines and their receptors. Nowadays, important role of RANK/RANKL/OPG system in the pathophysiology of osteoporosis is well known, but it is still important to investigate the intracellular signaling pathways in the development of osteoporosis and other metabolic bone diseases