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Biomedical subjects

V Nikolić

Publications and source records attributed to V Nikolić.

At least 19 recordsLinked to original sources

The relaxant effect of vasoactive intestinal polypeptide in the isolated canine uterine artery: the role of endothelium.

The purpose of this study was to examine the effect of vasoactive intestinal polypeptide (VIP) on the uterine artery obtained from non-pregnant dogs. VIP (3 x 10(-9)-3 x 10(-7) M) induced concentration-dependent relaxation in canine uterine arteries with intact endothelium, pre-contracted with 10(-5) M phenylephrine (pEC(50) = 7.52 +/- 0.02, maximal response was 82.19 +/- 2.15%, n = 36). The administration of the cyclooxygenase inhibitor indomethacin (10(-5) M) or 4-aminopyridine (4-AP), a blocker of potassium channels (10(-5) M), did not modify the relaxation induced by VIP. Contrary to this, N(G)-nitro-L-arginine (L-NOARG) (10(-5) M) inhibited relaxation is evoked by VIP. Indomethacin applied with L-NOARG did not provoke further inhibition of VIP-induced relaxation. In the presence of both L-NOARG and L-NOARG + indomethacin, 4-AP led to the further inhibition of VIP-induced relaxation of canine uterine artery. It is concluded that VIP induces endothelium-dependent relaxation of uterine arteries of non-pregnant dogs, which can be entirely explained by the production of nitric oxide (NO) from the endothelial cells. We proposed that when NO synthesis is inhibited, VIP induces further relaxation, independent of the edothelium-derived relaxing factors, probably through activation of K(+) channels.

4-Aminopyridine↗

[Protective ventilation strategy in the acute respiratory distress syndrome].

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) contribute to progressive hypoxemia in critically ill patients. It has been proved that conventional mechanical ventilation with physiological respiratory volume contributes to further lung damage. In this respect, application of protective ventilatory strategy--pulmonary ventilation with limited volume and pressure can avoid mentioned consequences. The aim of this paper is to discuss mechanims by which elements contained in protective mechanical ventilation of patients with ALI/ARDS prevent further progrssive lung injury, to argue the effects of positive end--expiratory pressure and present insturctions for its application.

Humans↗

[Determination of beta-endorphin plasma concentrations in surgical patients with acute abdominal pain].

Abdominal pain and surgery, frequently associated with this kind of pain, modify plasma levels of stress-hormones and iniciates the response of endogenous analgetic system. The aim of this study was to determine serum concentration of beta-endorphine in patients with acute abdominal pain (n=12), which were surgically treated. Serum concentration of beta-endorphin was measured on five data points: before, during and after surgery. During abdominal surgery serum concentration of beta-endorphin was increased by 7% compared to preoperative period; in postoperative period the concentration continued to rise and remained increased within next hours. The maximal levels of beta-endorphine were not observed during, and immediately after surgery. Postoperatively, between 6 and 8 p.m. on the day of surgery, maximal level of beta-endorphin was noted, which was even ten times higher than to preoperative value. Plasma level of beta-endorphin fell to the baseline values 24 hours after surgery. In conclusion, abdominal surgery induces a postponed (delayed) increase in serum beta-endorphine levels, which are associated with modulation of preoperative, intraoperative and postoperative pain perception.

Abdomen, Acute↗

Ultrasound measurement in defining the regional distribution of subcutaneous fat tissue.

The aim of this research is to determine the significance of ultrasound diagnostics in measuring the thickness of subcutaneous fat tissue as well as to point out sex and age differences in regional distribution of subcutaneous fat tissue. The research included 37 men and 33 women with different body mass indexes. Ultrasound measuring of subcutaneous fat tissue was conducted on 16 measuring points. The thickness of subcutaneous fat tissue measured by ultrasound and estimated proportion of fat tissue obtained by comparative methods coincided mostly on the back side of the upper arm, lower abdominal region in interspinal line and the front side of the forearm. Analysis of the subcutaneous fat tissue distribution indicates that there is more equal accumulation of fat tissue in women than in men. BMI limit value for obesity is not the same for men and women because the point at which abdominal region becomes the main storage of subcutaneous fat in body depends on sex. That BMI value represents the physiological beginning of obesity since it marks the change in distribution pattern of subcutaneous fat tissue in different body regions.

Adipose Tissue↗

Glomerular involvement in myelodysplastic syndromes.

Several reports have documented various forms of glomerular diseases in adults with myelodysplastic syndromes (MDS), but similar reports in children are lacking. We describe two children with MDS-associated steroid-responsive nephrotic syndrome (NS). Patient 1, who had MDS with myelofibrosis, presented with hepatosplenomegaly, pancytopenia, chronic hepatitis, moderate proteinuria, hypocomplementemia and elevated ANA titer. During initial prednisone treatment proteinuria markedly diminished and partial but transient hematological improvement occurred. Relapse subsequently occurred that manifested by overt NS and pancytopenia. High doses of prednisolone led to remission of the renal disease, but hematological remission did not occur. Persisting pancytopenia and repeated infections terminated in sepsis, 2 years after the onset of the MDS. Patient 2, who had refractory anemia with clonal monosomy 19, presented with bowel disease, hepatosplenomegaly, anemia and non-organ-specific autoantibodies. Prednisone led to both clinical and hematological remission. The hematologic disease relapsed 12 months later, when nephrotic-range proteinuria, hematuria and mild azotemia were also found. Corticosteroid treatment led to long-lasting renal and hematologic remission, maintained by a small dosage of prednisone. In both patients, renal biopsy findings were consistent with those seen in idiopathic NS. A Medline search disclosed 16 cases of glomerulopathy in the course of MDS in adult patients. Clinical features included NS, usually accompanied by renal insufficiency with acute, chronic, or rapidly progressive glomerulonephritis. On biopsy, membranous nephropathy, crescentic or mesangial proliferative glomerulonephritis, and AL amyloidosis were found. We conclude: (1) that glomerular disease may be present and should be searched for in patients with MDS and (2) that MDS can be added to the list of rare conditions associated with corticosteroid-responsive NS in children.

Child↗

Interferometry in the assessment of biomechanical features of the masticatory system hard segments.

Biomechanical studies have found wide application and solved many problems in dental medicine. An interdisciplinary approach has allowed an ever-faster progress in the field. The aim of this study was to point out the advantages of holographic interferometry. With the use of this method, the study object is observed as a whole rather than as a substrate, thus providing a three-dimensional holographic image visualizing the load transmission from one jaw to another, tooth pressure against the alveolus, and strain of Sharpey's fibers, and yielding precise data on deformities, dislocations and force distribution.

Anthropometry↗

Osteogenic effect of a gastric pentadecapeptide, BPC-157, on the healing of segmental bone defect in rabbits: a comparison with bone marrow and autologous cortical bone implantation.

Gastrectomy often results in increased likelihood of osteoporosis, metabolic aberration, and risk of fracture, and there is a need for a gastric peptide with osteogenic activity. A novel stomach pentadecapeptide, BPC-157, improves wound and fracture healing in rats in addition to having an angiogenic effect. Therefore, in the present study, using a segmental osteoperiosteal bone defect (0.8 cm, in the middle of the left radius) that remained incompletely healed in all control rabbits for 6 weeks (assessed in 2 week intervals), pentadecapeptide BPC-157 was further studied (either percutaneously given locally [10 microg/kg body weight] into the bone defect, or applied intramuscularly [intermittently, at postoperative days 7, 9, 14, and 16 at 10 microg/kg body weight] or continuously [once per day, postoperative days 7-21 at 10 microg or 10 ng/kg body weight]). For comparison, rabbits percutaneously received locally autologous bone marrow (2 mL, postoperative day 7). As standard treatment, immediately after its formation, the bone defect was filled with an autologous cortical graft. Saline-treated (2 mL intramuscularly [i.m.] and 2 mL locally into the bone defect), injured animals were used as controls. Pentadecapeptide BPC-157 significantly improved the healing of segmental bone defects. For instance, upon radiographic assessment, the callus surface, microphotodensitometry, quantitative histomorphometry (10 microg/kg body weight i.m. for 14 days), or quantitative histomorphometry (10 ng/kg body weight i.m. for 14 days) the effect of pentadecapeptide BPC-157 was shown to correspond to improvement after local application of bone marrow or autologous cortical graft. Moreover, a comparison of the number of animals with unhealed defects (all controls) or healed defects (complete bony continuity across the defect site) showed that besides pentadecapeptide intramuscular application for 14 days (i.e., local application of bone marrow or autologous cortical graft), also following other pentadecapeptide BPC-157 regimens (local application, or intermittent intramuscular administration), the number of animals with healed defect was increased. Hopefully, in the light of the suggested stomach significance for bone homeostasis, the possible relevance of this pentadecapeptide BPC-157 effect (local or intramuscular effectiveness, lack of unwanted effects) could be a basis for methods of choice in the future management of healing impairment in humans, and requires further investigation.

Animals↗

Detection of CYP2D6*3 and 2D6*4 allelic variants by PCR-restriction fragment length polymorphism.

The mutant of CYP2D6*3 allele with A2637 deletion in exon 5 and the mutant of CYP2D6*4 allele G1934-->A, splice site defect are among the most common polymorphic alleles of CYP2D6 gene, resulting in a decreased or no activity of CYP isoenzyme. In this study, a reliable polymerase chain reaction-restriction fragment length polymorphism method for identification of CYP2D6*3 and CYP2D6*4 alleles was used to investigate the genotype and phenotype prevalence in the groups of normal controls, and of cirrhosis and cancer patients. The results showed none of 36 controls genotyped for 2D6*3 and 2D6*4 allele to have the 2D6*3 allele with frameshift mutation in exon 5, while 33% (n=12) were found to bear the 2D6*4 allele with G to A mutation at the intron 3-exon 4 junction. In breast cancer patients (n=35) genotyped for 2D6*3 and 2D6*4 alleles, none with 2D6*3 allele was found either, but 60% (n=18) were found to bear the 2D6*4 allele. In patients with head and neck squamous cell cancer, there was only one subject with 2D6*3 allele and he was heterozygous. Among them, as many as ten (40%) patients were found to bear 2D6*4 allele. In the cirrhosis group, none of the patients was found to have the 2D6*3 allele, while the CYP2D6*4 allele was found in 23% (n=6) patients. The phenotype predicted according to the genotype was as follows: in the control group, 3% of individuals were identified as poor metabolizers, 70% as extensive metabolizers, and 27% as heterozygote extensive metabolizers. In the group of breast cancer, 7% of the patients were identified as poor metabolizer, 57% as extensive metabolizer and 36% as phenotype. In squamous cell cancer and cirrhosis patients, the incidence of poor metabolizer was zero, and of heterozygotes extensive metabolizer 42% and 31%, respectively.

Alleles↗

Influence of pyridine and urea on the rat brain ATPase activity.

The neurotoxicity of pyridine and urea was investigated in respect to their ability to alter the activity of synaptosomal membrane Na+/K(+)-ATPase and Mg(2+)-ATPase. In vitro treatment with pyridine and urea stimulated Na+/K(+)-ATPase activity in a dose-dependent manner up to 40% and 60%, respectively. Mg(2+)-ATPase activity increased up to 40% after pyridine treatment, while urea had no effect at all. The neuroactive potencies of pyridine and urea were evaluated by estimating parameters Km and delta Vmax for enzyme stimulation, as well as Hill coefficient to estimate the levels of cooperativity for pyridine and urea binding. The results suggest that pyridine stimulates both enzymes, probably by interacting with some neuronal membrane components, and altering the lipid micro-environment of the ATPases. In contrast, urea stimulates the Na+/K(+)-ATPase only, assumingly by acting on it directly or via some other regulatory mechanism. Stimulation of Na+/K(+)-ATPase and Mg(2+)-ATPase by the substances tested and subsequent alteration of neuronal cell functioning could contribute to the CNS dysfunction upon chronic exposure to pyridine and urea.

Animals↗

Recurrent hemolytic uremic syndrome with hypocomplementemia and intestinal lymphangiectasia.

A 23-year old male patient had eight distinct episodes of hemolytic uremic syndrome (HUS) between 8.5 and 15 years of age, five of them accompanied by hypocomplementemia. In the further course, severe hypertension, renal insufficiency as well as protein-losing enteropathy due to intestinal lymphangiectasia developed, whilst hypocomplementemia persisted. The association of recurrent HUS with hypocomplementemia and intestinal lymphangiectasia may represent a new association within a subgroup of the atypical HUS.

Adult↗

Biomechanical features of axial injuries to the lower limbs and to the pelvic ring by motor car collisions.

By frontal car collision, passengers are exposed, commonly, by dynamic deceleration force, applied to the lower limb and acting in the direction of the femoral shaft axis. This force could be transmitted from the foot, or from the knee to the hip joint, resulting in typical fractures of the femoral shaft, upper part of the femur as of the acetabulum. The authors have described radiological feature and three dimensional definition of these fractures as well as their ergonomic characteristics. The purpose of this study was to explain biomechanical etiology of acetabular and proximal fractures of the femur. This analysis may be useful in prevention of these fractures.

Accidents, Traffic↗

Belgrade and Hantaan hantaviruses--the causative agents of severe haemorrhagic fever with renal syndrome in children in Serbia.

During an outbreak of haemorrhagic fever with renal syndrome (HFRS) in 1989, five children (3 girls, 2 boys, aged 6.8-16 years) with a severe form of the disease were treated; four of these were followed for 22-28 months. The main clinical features in all five patients were: fever, headache, myalgia, abdominal and back pain and vomiting; haemorrhagic syndrome was present in four children. Renal syndrome presented with severe acute renal failure in all five patients. All patients recovered. Serological confirmation by an indirect immunofluorescence assay, by enzyme immunoassay for IgM antibodies and by plaque reduction neutralization test showed infection by Belgrade virus in three and by Hantaan virus in two patients. It was not possible to differentiate these two serogroups on the basis of clinical features. This study provides further information on the circulation of different hantaviruses causing severe HFRS in Serbia.

Adolescent↗

Focal glomerular sclerosis and nephrotic syndrome in spondyloepiphyseal dysplasia.

The association of a spondyloepiphyseal dysplasia and disproportionate short stature with focal glomerular sclerosis is reported in two girls. Renal disease manifested by proteinuria at the age of 2.5 and 11 years, leading to treatment-resistant nephrotic syndrome over 15 and 45 months, respectively. One patient went into end-stage renal failure shortly after nephrotic syndrome developed, the other died from sepsis. The association of spondyloepiphyseal dysplasia and focal glomerular sclerosis with nephrotic syndrome may represent a distinct disease entity.

Adolescent↗

Asymmetrical modulation of immune reactivity in left- and right-biased rats after ipsilateral ablation of the prefrontal, parietal and occipital brain neocortex.

We report here on the lateralized brain immunomodulation in male Wistar rats, a phenomenon related to the rotational bias of animal and the site of cortical lesion. Rats assigned to left- and right-rotators in a cylindrical Plexiglass rotometer were subjected to the ablation of the ipsilateral prefrontal cortex (PFC), parietal cortex (PC) and occipital cortex (OC) and sensitized with bovine serum albumin (BSA) in complete Freund's adjuvant. Intact and sham-lesioned left-biased animals demonstrated increased Arthus and delayed hypersensitivity skin reactions and antibody production to BSA in comparison with corresponding right-biased animals. PFC ablation decreased humoral and cellular immune responses to BSA in left- but increased in right-biased rats. Lesioning of PC decreased humoral immune reactions in left- but increased in right-rotating animals. OC ablation failed to produce immunological abnormalities. These results suggest that immunopotentiation is associated with the left neocortex, and immunosuppression with the right neocortex. The prefrontal cortex appears to be particularly associated with immune reactions.

Animals↗

[Surgical aspects of liver resection based on 5 years' data].

From 1988 to 1993 thirty liver resections were performed in thirty patients. Eight were operated for suffering from hepatocellular carcinoma, four from metastasis of colon's adenocarcinoma, five for great hemangiomas and the rest for focal liver changes. Right lobectomy was performed in six cases, as well as two trisegmentectomies and two left lobectomies while segmentectomies in the rest. Periopretive mortality occurred in two cases as two patients died because of postoperative thrombosis of vena portae and massive gastrointestinal bleeding. Recidive of malignant tumors was established in five patients after year and in other five till the second year. Benign tumors are without recidives. Later resection is a safe procedure with a considerable selection of patients, with use of latest technical conveniences, application of grafts on branches of vena portae and with routine application of intraoperative ultrasonography. The paper contains diagnostical postulates, surgical techniques and anatomic and morphologic types of resection.

Female↗

[Possibilities of interventional ultrasonography in the differential diagnosis of pancreatic malignancy].

Pancreatic carcinoma is one of the most aggressive visceral malignancies with lethal ending in 99% of cases. Although diagnostic methods make a great progress, the world epidemiologists consider this disease to be increasing. The main reason for this is probably the problem of making early diagnosis. Various diagnostic techniques including ultrasonography often make no difference between benign and malignant changes. The aim of this paper is to consider values of pancreatic functions under the control of ultrasound in a group of patients. The examination included patients with evident pancreatic changes. By cytopathologic analysis of the gathered material clear diagnosis was made. In most cases malignancy was established. The aim of diagnostic examination is to make diagnosis as early as possible, using minimal number of tests which should be the least invasive and traumatic for patients. As a diagnostic method ultrasonography is fast and simple which provides better chances for patients with pancreatic carcinoma.

Adult↗

[The hyperventilation syndrome in children].

Hyperventilation syndrome is not a rare disorder present primarily in children, but in adolescents too. It points to anxiety in children with or without family problems. The clinical picture is polymorphous and often without a clear connection with hyperventilation. That is why it is necessary for the physician to be aware of this problem in practice. The diagnosis is made on the basis of clinical picture and hyperventilation provocative test, when one expects this disorder might occur. We have reported five cases of children with this syndrome, with a special review concerning clinical picture and the way which led to the confirmation of diagnosis.

Adolescent↗