ANALYSIS OF THE RESULTS OF SURGICAL PROCEDURES ADVISABLE FOR CHRONIC PANCREATITIS WITH THE PREDOMINANT LESION OF THE PANCREATIC HEAD

Recently, studies comparing various variants of operations to establish the optimal method of surgical treatment for chronic pancreatitis with pancreatic head lesions from the point of view of evidence-based medicine have been carried out in the world. However, these comparative studies do not take into account differences in the clinical and morphological forms of the disease, in particular, chronic pancreatitis with a predominant and isolated lesion of the head. Subtotal resection of the pancreatic head with proximal pancreatojejunostomy, suitable for an isolated lesion of the head, does not solve all the problems of chronic pancreatitis with a predominant lesion of the head. In this case, the violation of the outflow of pancreatic juice along the pathologically changed main pancreatic duct from the left half of the gland is not eliminated. It is impossible to unambiguously support the hypothesis of the feasibility of performing subtotal resection of the pancreatic head with proximal pancreatojejunostomy in chronic pancreatitis with a predominant lesion of the head with a uniformly expanded main pancreatic duct. With this form of chronic pancreatitis, cicatricial strictures can form in the main pancreatic duct, which can lead to ductal hypertension and serve as an indication for reoperation. The feasibility of using Beger operation in chronic pancreatitis with a predominant lesion of the head is doubtful, since the intersection of the isthmus and the need for a T-shaped longitudinal pancreatojejunostomy makes this intervention technically difficult and unsafe. Based on the studies performed, it is impossible to say with certainty about the reliable advantages of one type of operations over another. To obtain reliable results, it’s necessary to conduct evidence-based studies comparing subtotal resection of the pancreatic head with longitudinal pancreatojejunostomy with other types of interventions only for chronic pancreatitis with a predominant head lesion, excluding from the study patients with chronic pancreatitis with isolated head lesion

Izloženost genotoksičnim agensima iz životnog okoliša tijekom prenatalnog razvoja i djetinjstva

Health disorders and diseases related to environmental exposure in children such as cancer and immunologic disturbances (asthma, allergies) are on the rise. However, complex transplacental and prepubertal genotoxicology is given very limited consideration, even though intrauterine development and early childhood may be critical for elucidating the cancer aetiology. The foetus is transplacentally exposed to contaminants in food and environment such as various chemicals, drugs, radiochemically contaminated water and air. Target organs of xenobiotic action may differ between the mother and the foetus due to specific stage of developmental physiology and enzyme distribution. This in turn may lead to different levels of clastogenic and aneugenic metabolites of the same xenobiotic in the mother and the foetus. Adult’s protective behaviour is not sufficient to isolate children from radioisotopes, pesticides, toxic metals and metalloids, environmental tobacco smoke, endocrine disrupting chemicals, and various food contaminants, which are just a part of the stressors present in a polluted environment. In order to improve legislation related to foetus and child exposure to genotoxic and possibly carcinogenic agents, oncologists, paediatricians, environmental health specialists, and genotoxicologists should work together much more closely to make a more effective use of accumulated scientific data, with the final aim to lower cancer incidence and mortality.Unatoč velikim naporima da se smanji okolišna izloženost u djece se dalje bilježi trend porasta pojavnosti karcinoma i imunosnih poremećaja (astma, alergije). Premda su intrauterini razvoj i rano djetinjstvo kritično razdoblje za tumačenje etiologije nastanka karcinoma, transplacentalna i prepubertetna genotoksikologija do danas su slabo istražene. Fetus je transplacentalno izložen brojnim fizikalnim i kemijskim čimbenicima: kontaminantima iz hrane i okoliša, radiokemijski kontaminiranoj vodi, zraku te lijekovima. Ciljna tkiva za djelovanje ksenobiotika mogu biti različita u majke i fetusa zbog različitosti u razvojnoj fiziologiji i distribuciji enzima. Zbog toga u organizmu majke i fetusa mogu nastati različite razine klastogenih i aneugenih metabolita istog ksenobiotika. Zaštitna uloga odraslih u namjeri da spriječe negativne utjecaje onečišćenog okoliša na djetetovo zdravlje često je ograničena jer su radioizotopi, olovo, PCB, pasivno pušenje, živa, endokrino aktivne tvari, pesticidi i kontaminanti prisutni u svim životnim područjima tijekom razvoja i rasta djeteta. Kako bi se poboljšalo zakonodavstvo vezano uz izloženost djece genotoksičnim i vjerojatno kancerogenim tvarima, tijekom razvoja potrebna je bolja suradnja onkologa, pedijatara, stručnjaka zdravstvene ekologije i genotoksikologa. Na taj način ostvarilo bi se uspješnije iskorištavanje postojećih znanstvenih podataka u cilju smanjenja incidencije karcinoma i mortaliteta

Abiotic ammonium formation in the presence of Ni-Fe metals and alloys and its implications for the Hadean nitrogen cycle

Experiments with dinitrogen-, nitrite-, nitrate-containing solutions were conducted without headspace in Ti reactors (200°C), borosilicate septum bottles (70°C) and HDPE tubes (22°C) in the presence of Fe and Ni metal, awaruite (Ni80Fe20) and tetrataenite (Ni50Fe50). In general, metals used in this investigation were more reactive than alloys toward all investigated nitrogen species. Nitrite and nitrate were converted to ammonium more rapidly than dinitrogen, and the reduction process had a strong temperature dependence. We concluded from our experimental observations that Hadean submarine hydrothermal systems could have supplied significant quantities of ammonium for reactions that are generally associated with prebiotic synthesis, especially in localized environments. Several natural meteorites (octahedrites) were found to contain up to 22 ppm Ntot. While the oxidation state of N in the octahedrites was not determined, XPS analysis of metals and alloys used in the study shows that N is likely present as nitride (N3-). This observation may have implications toward the Hadean environment, since, terrestrial (e.g., oceanic) ammonium production may have been supplemented by reduced nitrogen delivered by metal-rich meteorites. This notion is based on the fact that nitrogen dissolves into metallic melts