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Biomedical subjects

M Popovic

Publications and source records attributed to M Popovic.

At least 19 recordsLinked to original sources
PubMed2006

Neurophysiological effects of mistletoe (Viscum album L.) on isolated rat intestines.

Mistletoe (Viscum album L.) is well known as a medicine from ancient times and the earliest notes. Today it is used as a remedy. The aim of this research was to examine the effects of mistletoe extracts and their components on some neurophysiological parameters in rat intestines. The tonus and contractile responses of isolated intestinal segments (duodenum, ileum and distal colon) were analysed. The experiment was carried out in three groups. In the first group (control group) different concentrations of acetylcholine were added into the organ bath (10-50 nmol/L). In the second group, mistletoe extracts were added into the organ bath with increasing concentrations and in the third group, atropine, a non-selective muscarinic receptor antagonist, was added into the organ bath (concentration 10(-7) mol/L) and after atropine plant extracts were administered. The results obtained suggest that extracts from different parts of mistletoe have neurophysiological effects and change intestinal contractions. The results also suggest that the effects of mistletoe extracts on intestinal contractility act via cholinergic pathways, activating muscarinic receptors in the intestines. However, in order to establish the subtype of receptors, further investigations are necessary where selective antagonists of muscarinic cholinergic receptors should be used.

Animals↗
PubMed2005

Characterization of upper arm synergies during reaching tasks in able-bodied and hemiparetic subjects.

BACKGROUND: In the past, several studies showed the existence of a synergistic behavior between elbow and shoulder joints during reaching movements in able-bodied subjects. The aim of this paper was to characterize the modifications of upper arm synergies during reaching induced by stroke. METHODS: Ten able-bodied right-handed subjects, eight right-handed subjects with hemiparesis affecting the right (dominant) upper limb participated in the experiments. The kinematics of shoulder and elbow joints have been recorded in all the participants during selected reaching movements. From the eight-like plots characterizing the relationship between shoulder and elbow angular velocities, a topological parameter (named as C approximately ) representing the linear approximation of the synergy between the two angular velocities has been extracted. FINDINGS: The results of these experiments showed that C approximately could be used as a figure of merit for the comparison of performance in able-bodied and hemiparetic persons. The hemiparetic subjects showed a significantly higher spreading of the values of C approximately for the different reaching movements when compared with the performance of able-bodied subjects. INTERPRETATION: This work showed that hemiparesis modified upper arm synergies and could provide a protocol for the assessment of upper limb function. Moreover, important applications of this method could be found in the development of biomimetic algorithms for the control of upper extremities during reaching in humanoid robots, and in the design of customized "games" in neurorehabilitation procedures implemented by using robotic and mechatronic platforms.

Adult↗
PubMed2005

Survivin is a negative prognostic marker in medulloblastoma.

Survivin is a member of the inhibitor of apoptosis protein family, which is over-expressed in many human cancers. Our aim was to analyse survivin expression in medulloblastoma, its association with aberrant activation of the WNT (wingless) pathway and to test the prognostic significance of survivin expression. We immuno histochemically analysed survivin expression and localization of beta-catenin, a downstream mediator of the WNT pathway, in 56 cases of medulloblastoma. Survivin was detected in the nuclei of tumour cells in all cases, but the proportion of positive nuclei varied from 0.5 to 31.3%. Survivin expression tended to be higher in medulloblastomas with an aberrant activation of the WNT pathway (nuclear localization of beta-catenin), but did not correlate with histological type, age group or dissemination via cerebrospinal fluid pathways. Survivin expression and dissemination status were two independent negative prognostic variables for the overall survival of patients with medulloblastoma. In conclusion, survivin is up-regulated in medulloblastomas. It is a negative prognostic marker and a potential therapeutic target.

Adolescent↗
PubMed2004

First thousand rectal cancer cases--local recurrence and survival.

In the period 1990 - 2002, 1674 patients with colorectal carcinoma were operated in the First Surgical Clinic, Third Department for Colorectal Surgery. In 1264 cases (75.5%) rectal carcinoma was the indication for surgical treatment. Sphincter saving procedures (SSP) were performed in 824 (65.2%), abdominoperineal resections (APR) in 340 (26.9%) and resections of rectum with definitive stoma (Hartmann procedure) in 100 (7.9%) patients. We analyzed 1095 cases where curative SSP or APR were performed. All cases where curative resection was not possible because of liver metastases or inability to excise all macroscopic disease were excluded. In the group of patients where SSP was performed (767 cases), there were 26.6% high colorectal anastomoses (8cm from anal verge), 65.4% with low (4-8cm from anal verge) and 8.0% with intersphincteric coloanal anastomosis (cm from anal verge). Patohistological exam showed 5.3% Dukes A, 53.1% Dukes B, 36.5% Dukes C and 4.9% Dukes D. In the APR group (328 cases) there were 1.,5% Dukes A, 32.4% Dukes B, 62.1% Dukes C and 3.5% Dukes D. In this study we analyzed local recurrence and five-year survival in both groups. Recurrence of the disease was registered in 325 (29.6%) out of 1095 patients. Local recurrence was found in 81 (7.,4%) patients. In the SSP group recurrence occured in 215 (28.0%) out of 767 curative resections. Local recurrence alone was found in 53 patients (6.9%). SSP group was also divided into two subgroups; in the first group TME was performed and in second transection of mesorectum was carried out. Analyzing local recurrence in these two groups, in the TME group it was 7.6% and in the transection group 5.6%. In the APR group recurrence was registered in 110 (33.5%) out of 328 patients while local recurrence alone was found in 28 (8.5%) cases. Analyzing mortality we found that 234 (21.4%) out of 1095 patients died during follow-up. In the SSP group 154 out of 767 patients (20.1%) died. In the TME group mortality was 21.7% and in the transection group 16.9%. Mortality in the APR group showed that 80 out of 328 (24.4%) patients died during follow-up. Analysis by the Kaplan-Meier's test shows cumulative survival of 0.69 for all cases. In the SSP group cumulative survival is 0.72 and in the APR group 0.64 with statistically significant difference (p .001). In the TME group cumulative survival is 0.75 and in the transection group 0.,72 with statistically significant difference (p .05). We believe that performing SSP should be encouraged whenever it is possible because there is no difference in local recurrence rates and survival compared to APR. Transection of mesorectum can safely be performed in most cases with tumors located more than 8 cm form anal verge. We believe that exact preoperative staging and preoperative radiotherapy could improve results.

Adolescent↗
PubMed2003

Influence of heavy traffic, city dwelling and socio-economic status on nasal symptoms assessed in a postal population survey.

BACKGROUND: The association between social position, living environment and nasal symptoms is inconsistent. We wanted to test how living environment, occupation and social position were associated with nasal symptoms. METHODS: In a postal survey study of a random sample of 12,079 adults, aged 20-59 years living in the southern part of Sweden the relationship between nasal symptoms, socio-economic status and environmental factors was analysed. RESULTS: The response rate was 70% (n = 8469) of whom 33% reported significant nasal symptoms. Nasal discharge, thick yellow discharge, a blocked nose, sneezing and itching were strongly associated with living close to heavy traffic or living in cities. Most of the nasal symptoms provoked by extrinsic factors were more frequently reported among subjects who lived close to heavy traffic and in cities. Apart from thick yellow discharge and nasal symptoms provoked by damp/cold air which were more common in the socio-economic position "low" no relation to the socio-economic group was found. The prevalence of self-reported hay fever was neither affected by site of living nor by socio-economic status. Nasal symptoms evoked by "allergic" factors were linked to asthma but symptoms evoked by non-allergic factors were linked to chronic bronchitis/emphysema CBE. CONCLUSIONS: To conclude, we found a strong relation between geographical site and the prevalence of self-reported nasal symptoms which emphasizes the environment as a risk factor for nasal symptoms. Only by merging the socio-economic groups into "low" and "middle/high" an association to nasal symptoms was apparent. Nasal symptoms evoked by "allergic" factors were linked to asthma but symptoms evoked by "non allergic factors" were linked to CBE.

Adult↗
PubMed2002

A Tat subunit vaccine confers protective immunity against the immune-modulating activity of the human immunodeficiency virus type-1 Tat protein in mice.

The rational design of new therapies against HIV-1 necessitates an improved understanding of the mechanisms underlying the production of ineffective immune responses to HIV-1 in most infected individuals. This report shows that the CD8(+) T cell responses to gp120 were greatly diminished in mice vaccinated with a bicistronic gp120-Tat DNA vaccine, compared with those induced by a DNA vaccine encoding gp120 alone. The CD8(+) T cell responses induced by the latter included strong gp120-specific IFN-gamma secretion and protective antiviral immunity against challenge by a vaccinia-env pseudotype. The degree to which Tat influenced CD8(+) T cell responses depended on the bioactivity of Tat. Thus, a bicistronic DNA vaccine that expresses gp120 and a truncated Tat defective for LTR activation elicited strong IFN-gamma -secreting CD8(+) T cell responses to gp120 but conferred only marginal protection against the vaccinia-env challenge. The effect of Tat was completely blocked, however, by immunization with inactivated Tat protein before vaccination with the bicistronic gp120-Tat DNA vaccine.

AIDS Vaccines↗
PubMed2002

St. John's wort (Hypericum perforatum L.) and kindling epilepsy in rabbit.

Effects of different extracts of Hypericum perforatum L. on the kindling epileptic discharges were analyzed. The experiment was carried out on Chinchilla rabbits with chronically implanted electrodes in cortical structures and hippocampus. In our study we used water, n-butanol and ether fractions (mass concentrations 0.1 g/ml) of crude ethanol extract of Hypericum perforatum. The particular extracts were given intramuscularly in single dose of 1 ml/kg BW. The bioelectric activity was registered before and after applications of each extracts. The obtained results show that the effect depends on the constituents present in particular fractions. The repression of epileptic activity was in correlation with the polarity of plant constituents. Most polar constituents that remained in water fraction exerted highest antiepileptic activity in all (100%) animals tested. Substances present in butanol fraction repressed the epileptic manifestations in 40% of animals with kindling epilepsy, whereas lipid-soluble constituents in ether fraction potentated the epileptic activity.

Animals↗
PubMed2002

[Intraoperative and postoperative complications of splenectomy].

Spleen is being surgically removed because of trauma, in diagnostic and-or therapeutical purposes because of the benignant and malignant diseases. The percentage of morbidity during and after splenectomy is relatively low. During surgery might occur bleeding, trauma of the pancreatic tail, stomach, lineal flexure of the colon, left hemidiafragm, left suprarenal gland and upper pole of the left kidney, which must be correspondingly reclaimed during the same intervention. In the early postoperative period, postoperative bleeding, subfrenic abscess, pulmonal atelectasis, bronchopneumonia and left pleural extravasations might occur. Especially is important notification of these events in due time and adequate conservative and surgical treatment. After splenectomy, there is an increase of the number of trombocytes, which might lead to the tromboembolic complications. In the prevention of these complications in the postoperative period prolonged antiagregation therapy is suggested. Postsplenectomy sepsis is very late, general complication of splenectomy, which occurs because of the lower immunity in the child age. To prevent these complications, partial splenectomies, reimplantations of the spleen, prolonged application of the penicillin medicines after splenectomy and antipneumococcal vaccine are performed.

Humans↗
PubMed2001

Shwachman-Diamond syndrome with exocrine pancreatic dysfunction and bone marrow failure maps to the centromeric region of chromosome 7.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency and hematologic and skeletal abnormalities. A genomewide scan of families with SDS was terminated at approximately 50% completion, with the identification of chromosome 7 markers that showed linkage with the disease. Finer mapping revealed significant linkage across a broad interval that included the centromere. The maximum two-point LOD score was 8.7, with D7S473, at a recombination fraction of 0. The maximum multipoint LOD score was 10, in the interval between D7S499 and D7S482 (5.4 cM on the female map and 0 cM on the male map), a region delimited by recombinant events detected in affected children. Evidence from all 15 of the multiplex families analyzed provided support for the linkage, consistent with a single locus for SDS. However, the presence of several different mutations is suggested by the heterogeneity of disease-associated haplotypes in the candidate region.

Alleles↗
PubMed2001

Double vessel extension of spontaneous left main coronary artery dissection in young women treated with thrombolytics.

Spontaneous coronary artery dissection is an extremely rare cause of myocardial infarction. The prognosis and treatment of coronary artery dissection have not yet been defined. We report on a 42-year-old woman who was admitted to the emergency unit of a regional hospital with central chest pain and electrocardiographic signs of extensive acute anterior myocardial infarction (MI). She was treated with thrombolytics, yet her condition deteriorated rapidly, resulting in cardiogenic shock. An angiogram revealed dissection of the left main coronary artery that extended into the anterior descending (LAD) and circumflex arteries (LCX). At autopsy a recent anterolateral MI of the left ventricle was found. Dissection of the left coronary artery system was confirmed. Extension of the dissection may have been due to thrombolytic treatment.

Adult↗
PubMed2001

Glycolipoprotein extract (G-90) from earthworm Eisenia foetida exerts some antioxidative activity.

Antioxidants protect DNA, proteins and lipids in the body from damage. These types of damages are a major contributor to aging and to degenerative diseases such as cancer, cardiovascular disease, immune-system decline, brain dysfunction and cataracts. The effect of glycolipoprotein extract of Eisenia foetida (G-90) as an antioxidant was investigated in cultured human fibroblasts and epithelial cells. After treatment of the cells with H2O2 for 4 h, G-90 completely allows the cells to recover and stimulated their growth. When the cells were incubated with G-90 48 h before the treatment with H2O2, the oxidative damage of the cells did not occur. Thus, G-90 had an apparent protective effect against the toxicity of H2O2 and stimulated the growth of the cells. Ascorbic acid, a known antioxidant, did not allow the growth of the cells to recover after damage nor did it protect them, unless it was added simultaneously with H2O2. The antioxidative activity of G-90, together with its antibacterial and mitogen activities, could be useful in the study of G-90 as a wound-healing agent.

Animals↗
PubMed2001

September 2000: 15 year old girl with intracranial lesion.

The September COM: We reported the case of a 15 year old white girl with solitary brain cortical lesion clinically mimicking meningioma. Microscopic examination revealed histiocytic lesion with foamy and giant cells predominately of Touton type. Subsequent clinical examination did not reveal any similar lesion in the skin or in other location. Expression of S-100 protein in histiocytes is unusual finding, but has been reported recently in juvenile xanthogranulomas (JXG). The only specific ultra-structural finding differing JXG from histiocytic neoplasm of Langerhans' cells histiocytosis type seems to be Birbeck granules.

Adolescent↗
PubMed2000

Stability criterion for controlling standing in able-bodied subjects.

A new stability criterion that can be used to assess the standing condition of a subject from center of pressure (CoP) measurements is presented. This criterion can be applied, for example, to control a standing prosthesis, which should allow a paraplegic subject to stand up, sit down and stand safely without using hands for support. Experiments conducted with able-bodied subjects enabled us to establish a relationship between its stability and the subject's CoP position. Four CoP stability zones were identified: high preference, low preference, undesirable and unstable zones. The high preference zone is defined as the area where the CoP is found 99% of the time during quiet standing. The area where the CoP is found during the remaining 1% of the time is called the low preference zone. The undesirable zone is defined as the CoP area where the subject is forced to change posture in order to maintain balance, and the unstable zone is defined as the CoP area in which the subject is forced to step forward, backward or sideways to maintain stability. A general model of the proposed four stability zones was derived, which can be used to compute stability zones a priori for any subject and thus allows one to assess the subject's stability condition from the CoP measurements.

Adult↗