Biomedical subjects

Aleksandar Vcev

Publications and source records attributed to Aleksandar Vcev.

11 recordsLinked to original sources

PubMed2006

Intestinal gases and flatulence: possible causes of occurrence.

All gases entrapped in closed body cavities are destined to be partially or completely absorbed. Intestinal gases often accumulate and cause flatulence. This paper proposes a simple concept of intestinal gas occurrence based on our knowledge on gas resorption in other body cavities. Compliance of intestinal and abdominal walls makes pressure in the liquid chyme bubbles near 760 mmHg. Intestinal gases are from three sources. Air can be swallowed, CO2 come from the gastric acid neutralisation and from intestinal bacterial colonies that also produce hydrogen and methane. In continuously mixed liquid chyme, the total pressure of blood gases is similar or lower than in the venous blood ( or=760 mmHg). Some local production of bacterial gases with partial pressure of more than 90 mmHg is required, so the resulting small bowel bubbles would contain less than 20% of bacterial gases. If peristaltic mixing of chyme is prevented by an obstacle, local pressures of bacterial gases build up, form bubbles that fuse and finally make X-ray visible aeroliquid levels. Bacterial gases make almost 3/4 of the flatulence. Formation of bubbles destined to become flatulence might depend on altered rheological condition of the large bowel content, with local abundant production of bacterial gases near bacterial colonies. Gases are unable to diffuse rapidly through the dense liquid content and local accumulation allows formation of bubbles mainly of bacterial gases. Their pressure can be higher 760 mmHg, since they are stretching the thick content. Poor diffusion of gases keeps them almost free of blood gases and their entrance makes them bigger. As the content moves along the colon, the content is becoming more solid and gases are becoming entrapped in large bubbles. Some blood and bacterial gases are absorbed and exhaled, but the remaining quantity has no other escape except flatulence. Flatulence rich in bacterial gases might be the price for the large bowel water reabsorption. It seems that beside the peroral use of antibiotics active in the colon, little can be done to reduce flatulence.

Bacteria↗

PubMed2006

Esomeprazole versus pantoprazole for healing erosive oesophagitis.

The aim of this study was to compare the efficacy of esomeprazole and pantoprazole with regard to healing and relief from gastroesophageal reflux disease-related symptoms. I this multicentre, randomized, single-blind study 180 patients (ITT population) diagnosed with endoscopically proven GERD grade A,B,C received esomeprazole (40 mg once daily (o.d.), n = 90) orpantoprazole (40 mg o.d., n = 90). Healing and relief from GERD-related symptoms were assessed at first and final visit (after 4 or 8 weeks of treatment). Esomeprazole 40 mg provided significantly greater healing than pantoprazole 40 mg after 4 weeks of treatment in patients with EE (77.8% vs. 72.2%). Esomeprazole-treated patients were healed after up to 8 weeks of treatment similar those treated with pantoprazole (92.2% vs. 91.1%). The proportion of heartburn-free days was similar in patients treated with esomeprazole and to those treated with pantoprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2005

The results of Helicobacter pylori eradication on repeated bleeding in patients with stomach ulcer.

The triple therapy of Helicobacter pylori eradication prevents repeated bleeding from stomach ulcer. The aim of this one-way blind prospective study was to evaluate the efficiency of the two-week triple therapy for Helicobacter pylori eradication in preventing renewed bleeding in patients with stomach ulcer within one year. This research included 60 hospitalized patients with bleeding stomach ulcer and positive Helicobacter pylori infection, 34 men and 26 women (average age 59.7 years). The patients were given therapeutic scheme of omeprazol--amoxicilin--metrodinazol (OAM) eradication for 14 days. Eradication of H. pylori infection was defined as lack of proof of the infection one month or several months after therapy suspension. By applying triple OAM therapy within two weeks the eradication was successful in 72%. In the group of 17 H. pylori positive patients there were 8 patients (47.6%) with repeated stomach ulcer and 3 patients (18%) with bleeding. Within the group of 43 H. pylori negative patients there were only 2 patients (4.65%) with repeated stomach ulcer and 1 patient (2%) with bleeding, during the observed period of 12 months. This research confirms the hypothesis about the necessity of eradication of Helicobacter pylori infection in patients with bleeding stomach ulcer as prevention of repeated bleeding.

Amoxicillin↗

PubMed2005

[Viral hepatitis: Croatian consensus statement].

There has been a dramatic improvement in diagnostic procedures and therapy of viral hepatitis in the last 20 years. Improvements in therapy caused an increase in actual cost, however, with significant long-term savings through a decreased cost of treatment of advanced liver disease including liver transplantation. The Croatian National Board for Viral Hepatitis has decided to initiate the organization of consensus conference on viral hepatitis enabling the leading experts in the country to give the best possible recommendations for the diagnosis, prophylaxis and therapy in our circumstances. The Consensus Conference took place in Zagreb in June 2004, with update in March 2005, organized by the Croatian National Board for Viral Hepatitis, Reference Centers of the Ministry of Health for Chronic Liver Diseases, Infectious Diseases and AIDS, Croatian Society of Gastroenterology--Hepatology Section, Croatian Society for Nephrology, Dialysis and Transplantation, and Croatian Institute for Health Insurance. Invited experts provided written reports on the respective subjects that appear in this issue and their recommendations resulting in this consensus statement.

Consensus Statements as Topic↗

PubMed2005

[Treatment of the side effects of antiviral therapy].

The adverse effects of antiviral drugs are dose dependent and often reversible. The major side effects include influenza-like symptoms, hematologic abnormalities and neuropsychiatric symptoms. The influenza-like syndrome can be prevented by paracetamol taken at the time of the injection. Psychiatric adverse effects range from irritability to a severe depressive syndrome. Antidepressants, such as selective serotonin reuptake inhibitors, may be useful in the management. Adverse hematologic effects can occur very early during treatment. The platelet count often stabilizes rapidly, but neutropenia can deteriorate throughout treatment. In selected patients treatment with hematopoietic growth factor (filgrastim) may be useful. Ribavirin therapy may result in a dose-dependent reversible intravascular hemolytic anemia in 10% of patients. Adjunctive therapy with erythropoietin for ribavirin-induced anemia is currently under evaluation. Interferons and ribavirin are contraindicated in pregnancy. Contraception must be continued for 4 months (women) and 7 months (men) after ribavirin cessation. Lactic acidosis may be a rare complication of combination therapy in patients undergoing therapy for HIV and HCV. Any sign of mitochondrial DNA depletion syndrome calls for blood lactate measurement and, possibly, a modification of antiretroviral treatment. Lamivudine is well tolerated but the emergence of lamivudine-resistant (YMDD) HBV mutants is associated with the loss of clinical response. Adefovir dipivoxil effectively suppresses lamivudine-resistant HBV in chronic hepatitis B.

Antiviral Agents↗

PubMed2005

Thrombus size is associated with etiology of deep venous thrombosis--a cross-sectional study.

The aim of this study was to evaluate the impact of risk factors for deep vein thrombosis (DVT) on thrombus sizes in lower extremities. The size and extent of thrombus was scored according to International Consensus Committee for venous disease classification. After the diagnosis of DVT was established and its size scored, predominant risk factors for DVT in each patient were identified (malignant disease, thrombophilia, postoperative state, hormonal therapy, heredity, limb trauma, immobilization, others and unknown risk factors). The average thrombus score was 6 (95% CI 5.47-6.53). The analysis of thrombus size indicated that the largest thrombi were found in patients with malignancy. Their average score was 8.5 (95% CI 7-10) and was significantly higher than in patients with other risk factors for deep vein thrombosis. There was no significant correlation between numbers of days from the onset of symptoms to the moment of DVT diagnosis and thrombus score (r = -0.08, p = 0.38). Age was very slightly correlated to thrombus size (r = 0.19; p = 0.046), while the gender did not have significant impact on thrombus score (p = 0.074). The conclusion of our study was that etiology of thrombosis and particularly malignant diseases has the largest impact on venous thrombus size.

Adult↗

PubMed2004

Diagnostic value of a peroral sucrose permeability test in children with recurrent upper abdominal pain.

The access of ingested sucrose into blood and urine indicates the presence of mucosal lesions in the upper gastrointestinal tract. The study involved 42 children, aged 5-15, having recurrent upper abdominal pain and 43 peers with minor extra-abdominal complaints. Sucrose in urine was determined by thin layer chromatography. The test was positive in 27 out of 42 children having recurrent abdominal pain (64.3%) and in none of the control children (chi2 = 37.6, p < 0.0001). When correlated with endoscopic findings it was falsely negative in 12 out of 38 patients with endoscopically verified lesions of the stomach or duodenum and falsely positive in 1 out of 4 without lesions. Sensitivity of the test was 68.4%, specificity 97.9%, positive predictive value 96.3%. The test cannot be used as an alternative to endoscopy, but may serve for screening of candidates for it.

Abdominal Pain↗

PubMed2003

A model of dual circulation in liver acini with hypoxia regulated adenosine secretion.

It was postulated by W.W. Lautt that the hepatic artery flow compensation for changes in portal vein flow (the 'hepatic arterial buffer response') is regulated through the portal blood washout of adenosine from the small fluid compartment that surrounds the hepatic arterial resistance vessels. It is presumed that the adenosine secretion there is constant and independent of oxygen supply or liver demand. It was reported by others that liver secretes variable quantities of adenosine and that secretion is related to the level of liver hypoxia. This paper is an attempt to describe a model of acinar circulation without sources of constant adenosine secretion. The presented model is based on the fact that portal blood enters acinar space near the vascular stalk in the zone 1, while most of the arterial branches empty one-third from the interlobular septa, at the beginning of the zone 2, just downstream from the zone 1. Another important characteristic of liver architecture is that near 5/9 of lobular volume is in the zone 1. Liver cells in zone 1 are well oxygenated by the portal blood and they have low adenosine secretion that might seem almost constant. Since most arterial branches empty more peripherally, the zone 1 normally does not depend on the arterial circuit and most of arterial branches are governed by the adenosine secretion from the upstream zone 1. Low portal flow, would increase adenosine secretion from the zone 1 and thus dilate numerous downstream arterial resistance vessels. An increased flow from these arterial vessels would compensate any decrease in the portal flow. Zones 2 and 3 probably have higher adenosine secretion rates since the oxygenation depends on the amount of added arterial blood and on the liver cell metabolism. Some of the arterial branches in those zones are probably open all the time, preserving them zones from hypoxic injury. Since the main point for arterial inflow is concentrated downstream from the zone 1, in cases of low portal pressures, or elevated upstream resistance, some of the arterial blood might leave the acinus in retrograde direction via the portal branch and enter some other acinus as a part of portal blood. These arterio-portal communications might be important in cases of low or none portal flow when zone 1 is in hypoxia. In the 3D liver space with tightly packed acini, very complex and ever-changing patterns of combined antegrade and retrograde flows can be expected.

Adenosine↗

PubMed2002

[Hormonal regulation of gastric secretion and Helicobacter pylori].

Helicobacter pylori has been recognized as one of the most important factors that lead to chronic changes in the gastric mucosa. These changes have either direct or indirect impact on various intestinal hormones (gastrin, somatostatin, bombensin, cholecystokinin...) which regulate gastric secretion. Gastric secretion enhancement is mostly caused by higher concentration of serum gastrin. The mechanism in which the Helicobacter pylori infection influences the regulation of gastrin and other intestinal hormones is yet to be discovered. It is known that eradication of the Helicobacter pylori infection decreases serum gastrin concentration, thus decreasing gastric secretion and inflammatory changes of the gastric mucosa.

Gastric Acid↗

PubMed2002

[Duodenal ulcer and Helicobacter pylori infection].

The research accomplishment of Australian investigators Marshall and Warren, published in 1983, has entirely changed our understanding of ulcer genesis and proposed a new strategy in diagnostics and therapy of peptic ulcer disease. The key etiopathogenetic role of Helicobacter pylori has been recognised. Marshall confirmed on himself that Helicobacter pylori, as an infectious agent, fulfilled all Koch's postulates. The bacterial infection caused the mucosal inflammatory changes in his stomach which were rapidly resolved by antibiotics. During later clinical and experimental investigations the association of Helicobacter pylori and peptic ulcer has also been proved. Etiopathogenetic influence of Helicobacter pylori infection on duodenal ulcer development is nowadays very well known. Diagnostic guidelines, the modes of treatment and clinical management of these patients are mostly precisely defined. In this article, besides the general review of modern knowledge about Helicobacter pylori infection concerning epidemiology, etiopathogenesis, diagnostics and duodenal ulcer therapy, we are going to present also our results in the management of the large group of patients with duodenal peptic ulcer or ulcer scars.

Adolescent↗

PubMedDate not supplied

Retrospective analysis of Ki-67 antigen expression in paraffin tissue blocks of laryngeal squamous cell carcinoma.

The level of Ki-67 antigen expression has been proven to correlate with cellular proliferation. The aim of the study was to show correlation of Ki-67 expression with the clinical stage and its predictive value for the prognosis of laryngeal carcinoma. The study included 48 patients with surgically removed carcinoma of the larynx. Study results pointed to a significant difference in the mean value of Ki-67 reactivity between the study and control group consisting of cadaveric laryngeal tissue free from the disease. Correlation was found between the TNM stage of carcinoma and percentage of Ki-67-labeled cells. A significant correlation was also observed between Ki-67 reactivity at the time of laryngeal surgery and 2-year clinical outcome of the disease. Ki-67 reactivity was significantly higher in the group of patients with disease remission compared with the control group but was significantly lower as compared with the group of patients with poor outcome.

Adult↗