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Biomedical subjects

M Popović

Publications and source records attributed to M Popović.

At least 19 recordsLinked to original sources
PubMed2002

Scavenger activity of Allium psekemense B. Fedtsch.

In the present study the antioxidative properties of the bulbs, leaves and stalks of Allium psekemense B. Fedtsch were investigated. The activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, glutathione peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the content of total flavonoids, chlorophylls a and b, carotenoids, vitamin C and soluble proteins were determined. The results indicate that extracts from all plant organs exhibited antioxidant activity. The highest antioxidant activity was observed in the leaves. Furthermore, the ESR signal of DMPO-OH radical adducts in the presence of the leaf phosphate buffer (pH 7) extract was reduced by 54.3%.

Allium↗
PubMed2001

Effect of earthworm (G-90) extract on formation and lysis of clots originated from venous blood of dogs with cardiopathies and with malignant tumors.

The stability of homeostasis is important to keep a balance between coagulation and fibrinolysis. A disorder of homeostasis leads to different physiological changes and causes different diseases such as cardiopathies and malignant tumors. Cardiopathies is characterized by a hypercoagulation. In the malignant tumors, besides the hypercoagulation due to plasminogen activators (PA) formed inside the tumor, a disorder of homeostasis leads also to acceleration of the fibrinolysis. The variety of internal and external factors in both cases determine the deviation of time for the clots formation, as well as the lyses of blood and fibrin clots. In this study the venous blood as well as the blood and the fibrin clots, derived from healthy dogs, the dogs with cardiopathies and with malignant tumors, were examined for the time of coagulation and fibrinolysis by adding different substances. In these experiments we used a glycolipoprotein extract from earthworm tissue homogenate (G-90) and the proteolytic enzymes P I and P II, isolated from G-90. The efficacy of the tested substances was comparable with the clinically administered anticoagulants. The most significant differences in clotting time among the three tested groups of dogs were obtained by application of the original G-90. The results suggest a possibility that G-90, along with the fibrinolytic enzymes and other biologically active factors, also contains a factor that decelerates the formation of clot in a specific medium, such as the blood from the dogs with malignant tumors.

Animals↗
PubMed2001

Finite element modeling of electromagnetic signal propagation in a phantom arm.

Improving the control of artificial arms remains a considerable challenge. It may be possible to graft remaining peripheral nerves in an amputated limb to spare muscles in or near the residual limb and use these nerve-muscle grafts as additional myoelectric control signals. This would allow simultaneous control of multiple, degrees of freedom (DOF) and could greatly improve the control of artificial limbs. For this technique to be successful, the electromyography (EMG) signals from the nerve-muscle grafts would need to be independent of each other with minimal crosstalk. To study EMG signal propagation and quantify crosstalk, finite element (FE) models were developed in a phantom-arm model. The models were validated with experimental data collected by applying sinusoidal excitations to a phantom-arm model and recording the surface electric potential distribution. There was a very high correlation (r > 0.99) between the FEM data and the experimental data, with the error in signal magnitude generally less than 5%. Simulations were then performed using muscle dielectric properties with static, complex, and full electromagnetic solvers. The results indicate that significant displacement currents can develop (> 50% of total current) and that the fall-off of surface signal power varies with how the signal source is modeled. Index Terms-Control, electromyography (EMG), finite element (FE), modeling, prosthesis.

Arm↗
PubMed2001

[Protective colostomy or ileostomy?] ].

A group of patients is presented, where colorectal or coloanal anastomosis after resection was performed together with concomitant covering colostomy (102) or ileostomy (25), during the period 1985-2000. Covering colostomy was most often performed upon hepatic flexure (82.1%) and upon sigmoid colon (8.9%). The incidence of complications during performing or closure of colostomy was 6.8% with one case (0.8%) of death due to unsuccessful protection of primary anastomosis. The incidence of complications in covering ileostomy was 16%, with 3 (12%) deaths. Authors are analysing the data from literature about indications and technique of covering enterostomies, comparing them with their experience and concerning the choice of appropriate protective procedure. They came to conclusion that the reason for covering procedure has been in many instances reasonable, and that in the question of protection both methods are comparable, but covering ileostomy has potentially more dangerous complications. Therefore as a method of anastomotic protection authors are generally recommending covering colostomy except in technically specific cases.

Anastomosis, Surgical↗
PubMed2001

[10 years' of production and use of human rabies immunoglobulin in Yugoslavia].

Application of the rabies immunoglobuline is a compulsory part of the prophylaxis of rabies in all severe, transdermal lesions caused by rabies infected animals. Sylvatic rabies has spread in the past few years throughout the whole Yugoslavia, and human cases of rabies have also been reported in other East European countries. In order to achieve the highest level of rabies prophylaxis, apart from postinfective rabies vaccination, it is necessary to provide passive immunization using specific antibodies against rabies. After successful immunization of the young, healthy volunteers in 1990, National Blood Transfusion Institute, in cooperation with the Pasteur Institute from Novi Sad, prepared the first quantities of immunized plasma by plasmapheresis procedure and human rabies immunoglobuline. Without national production, sufficient quantities of human rabies immunoglobuline could not be provided, since the price on the world market is rather high (over $1000 per patient).

Antibodies, Viral↗
PubMed2000

Secondary intracranial meningiomas after high-dose cranial irradiation: report of five cases and review of the literature.

PURPOSE: To review cases of secondary intracranial meningiomas following high-dose cranial irradiation (>/= 10 Gy) identified in Slovenia between 1968 and 1998, to determine their histological profile and to review the literature on this topic. METHODS AND MATERIALS: Personal files of patients treated for secondary intracranial meningioma during a 31-year period were reviewed. In cases which met the criteria for radiation-induced tumors, steroid hormone receptor and Ki-67 status were analyzed. For the literature review, computerized database systems and reference lists from respective publications were used. RESULTS: Five patients (2 females, 3 males), 3-11 years old at the time of cranial irradiation, developed secondary meningioma after a latency period of 9.5-31.5 years. Three patients had multiple tumors and 2 developed recurrent disease. Of 9 histologically examined tumors, 5 were graded as benign and 4 as atypical meningiomas, with Ki-67 proliferative index 3.2 +/- 3.6 and 10 +/- 6, respectively. The ratio between positive and negative meningiomas regarding immunostaining for progesterone and estrogen receptors was eight-to-one and six-to-three, respectively. Cumulative actuarial risk of secondary meningioma in a cohort of 445 children 16 years or younger treated with high-dose cranial irradiation between 1968 and 1990 in Slovenia at 10, 20, and 25 years was 0.53%, 1.2%, and 8.18%, respectively. Out of 126 cases of radiation-induced meningiomas reported, 57% were females and 43% were males, with mean age at presentation 33 +/- 17.3 years. The majority (68%) of patients was irradiated during childhood. The latency period was significantly shorter in those who aged 5 years or less at the time of cranial irradiation (p = 0.04), and in those with atypical/anaplastic tumor (p = 0.01). Correlation between radiation dose and latency period could not be found. CONCLUSION: Secondary meningiomas following high-dose cranial irradiation are characterized by younger age at presentation, by higher male-to-female ratio and by biologically more aggressive variants compared to primary spontaneous meningiomas. Latency period correlated with the age at the time of cranial irradiation and with tumor grade but not with irradiation dose. Ki-67 immunoreactivity correlated with histological grade. The progesterone and estrogen receptor immunoreactivity was high. The risk for development of secondary meningioma after high-dose cranial irradiation was increasing with the time of follow-up.

Brain Neoplasms↗
PubMed2000

Pharmacodynamic study of Hypericum perforatum L.

The effects of Hypericum perforatum L. (Hypericaceae) crude ethanol extract (A), ethyl acetate extract (B), aqueous extract (C) and infusion (I), on pentobarbital induced sleeping time, intestinal motility, and their analgesic activity, have been investigated. Extracts A and B exhibited significant stimulatory and antidepressant effects on the CNS. Both extracts prolonged sleep, increasing time up to more than 25 min. The antidepressive activity of extract A was also achieved by significant reduction of the myorelaxant activity of diazepam. Extract B exhibited strong analgesic activity reducing abdominal stretching induced by acetic acid by nearly 50 %. Extracts A, B and C exhibited spasmolytic activity, significantly reducing intestine motility.

Acetic Acid↗
PubMed2000

Role of axon-deprived Schwann cells in perineurial regeneration in the rat sciatic nerve.

The role of Schwann cells (SC) in perineurial regeneration after nerve injury has not yet been resolved. It was hypothesized that SC alone are able to induce at least partial morphological restoration of the destroyed orthotopic perineureum (PN). To test the hypothesis, a permanently denervated segment of the rat sciatic nerve was made acellular by freeze-thawing, except in its most proximal part where non-neuronal cells were left intact. Restoration of the frozen segment by these cells was examined by electron microscopy and immunohistochemistry of the SC marker, S-100 protein, 4 and 8 weeks after injury. The PN regenerated from undifferentiated fibroblast-like cells. In the presence of migrant SC without axons, regenerated cells in the place of the former PN were stacked in several layers and, in accordance with the hypothesis, partially expressed typical features of the perineurial cells (PC): pinocytotic vesicles, short fragments of basal lamina and tight junctions. Migrant SC induced formation of pseudo-minifascicles even in the epineurium. In these, SC organized the adjacent fibroblasts into a multilayered circular sheath, and induced their partial differentiation towards perineurial cells. Further experiments demonstrated that regenerating axons are required for complete morphological differentiation of the regenerated perineurial cells either in the orthotopic PN or in minifascicles.

Animals↗
PubMed2000

Immune responses in nucleus basalis magnocellularis-lesioned rats exposed to chronic isolation stress.

The present study was designed to establish the influence of chronic social isolation stress on humoral and cellular immunity in nucleus basalis magnocellularis (NBM)-lesioned rats. Therefore, ten days after bilateral electrolytic lesions of NBM, adult male Wistar rats were immunized with bovine serum albumin in complete Freund's adjuvant (BSA-CFA) and placed individually or in groups of five rats during 21 days. On days 10 and 21 after immunization, the Arthus and delayed hypersensitivity skin reactions to BSA as well as anti-BSA antibody production were determined. On day 10, the diameter and intensity of delayed hypersensitivity skin reaction to BSA were significantly higher in social-isolated rats in comparison with the group-reared ones. On day 21, the diameter and intensity of the Arthus skin reaction were significantly higher in social-isolated rats compared to group-reared rats. Between days 10 and 21, the diameter and intensity of the Arthus skin reaction significantly increased in social-isolated rats, while the diameter of delayed hypersensitivity skin reaction significantly decreased. In contrast to social-isolated rats, there were no significant differences in Arthus and delayed hypersensitivity skin reactions in group-reared rats, between days 10 and 21. Also there were no significant differences in the production of anti-BSA antibody between social-isolated and group-reared rats. The relative spleen weight was significantly lower in social-isolated rats. These data suggest that chronic isolation stress modify humoral and cellular immunity in NBM-lesioned rats.

Animals↗
PubMed2000

[Surgical treatment of Crohn disease of the colon and rectum].

Colon can be affected by Crohn's disease together with the small intestine, as a direct extension from the diseased ileum, as an isolated disease with "skip lesions" or as an specific pathological entity. Experiences in the surgical treatment of 28 cases of isolated Crohn's disease of large intestine during the period 1980-1997 are presented. The overall mortality was 21.4%, and all operative procedures quoted in literature were used. The most common operation performed was colectomy with ileorectoanastomosis, in one or two stages (24.9%). Crohn's disease of colon is more persistent that fatal disease. With conservative or carefully elected operative treatment it is often possible to maintain good comfort and Quality of life, with restored continuity of digestive tract, for a long time. According to the literature, after removing of the diseased segment of large intestine, the recurrences are observed in more than 60% in longer postoperative period requiring permanent ileostomy. These recurrences seem to be more dependent of the natural history of disease, than of the choice of operation. In spite of the progress of medical treatment, the operative management is necessary in more than 70%, due to various surgical complications. The perianal form of the disease is to be treated medically, or by sparing surgical procedures.

Colon↗
PubMed2000

[Surgical treatment of ulcerative colitis--"pouch" or ileorectal anastomosis].

Treatment of Ulcerative Colitis was always a challenge for a therapeutist. The therapy of the disease is usually conservative but when refractory or complications occur, surgical treatment is the only appropriate solution. Evolution of surgical techniques in treatment of Ulcerative colitis from bipolar colostomies, by-pass procedures, partial resections, colectomies, proctocolectomies to recent restorative procedures with the ileal-pouch and preservation of the continuity of digestive tract, shows the severity of the disease and explains the dilemmas which surgeons had in choosing the appropriate operation. Inauguration of ileal reservoir in late seventies, brought a new advancement in postoperative results measured by better function and quality of life. Even the ileal reservoir proved its superiority in surgical treatment of Ulcerative colitis, some dilemmas still persist. Should be rectum and continuity of digestive tract preserved by ileal-rectal anastomosis or by restorative coloproctocolectomy and ileal-pouch-anal anastomosis?

Anastomosis, Surgical↗
PubMed2000

[Metastasis of malignant melanoma in the small intestine--case report].

Small bowel metastases of the malignant melanoma are usually discovered in 2-5% of the patients with malignant melanoma of the skin during the life. They are usually being diagnosed with a complication on the small bowel, such as occlusion, bleeding, anemia and perforation of the intestine. Authors show three patients with metastases of the malignant melanoma in the small bowel, which lead to invagination, subocclusion and anemia due to bleeding. In all the patients, resection of the small bowel was performed with termino-terminal anastomosis. One of them lived 7, the other 4 months after the surgery and is in pretty well condition, while third patient was not controlled at all.

Aged↗
PubMed2000

Screening for antioxidant properties of Salvia reflexa hornem.

The antioxidant properties of the wild growing sage species, Salvia reflexa Hornem., were investigated. The presence of superoxide (O(2)(.-)) and hydroxyl ((.)OH) radicals, malonyldialdehyde (MDA), reduced glutathione (GSH) and total flavonoids were observed in the above-ground parts of plant, as well as activities of the antioxidant enzymes superoxide-dismutase (SOD) and peroxidase (P-ase). The potential antioxidant activity of the methanol:water extract has been assessed based on scavenging activity of stable DPPH free radicals. By the means of TLC and LC/MS a screening for secondary plant products was performed. Significant quantities of O(2)(.-), (.)OH and MDA were observed. Thus, this species exhibited high SOD and P-ase activities as well as a content of total flavonoids. The dominant naturally occurring compound was rosmarinic acid. The results obtained suggested a high antioxidant activity of Salvia reflexa Hornem.

Antioxidants↗
PubMed2000

Long-term results after low anterior stapled anastomosis.

In the period 01.01.1991-12.31.1996, 286 low anterior stapled resections of the rectum due to rectal carcinoma were performed at the First Surgical Clinic, the Third Department for Colorectal Surgery, Belgrade. There were 57% males and 43% females, median age 59.6 years. The most common localization of tumor was in the distal third of the rectum 181 (63%). In the middle third, there were 89 (31%) and in the upper, intraperitoneal third 16 (6%). Histopathological examination revealed adenocarcinoma in all cases. All operative specimens were examined by one pathologist and classified according to the Gunderson-Sosin modification of Dukes classification. There were 14 (4.9%) in stage A, 167 (58.4%) in stage B (B1,B2,B3), 89 (31.1%) stage C (C1,C2,C3) and 16 (5.6%) stage D. According to Broders classification, there were 129 (45%) well differentiated, 142 (50%) moderately and 15 (5%) poorly differentiated tumors. Anastomotic dehiscence was found in 17 patients (5.95%), mostly conservatively treated, except in 6 cases where spreading peritonitis developed requiring operative treatment. There were 9 (3.1%) postoperative deaths, a half of them with specifically operation related mortality. Recurrence of the disease was registered in 47 (18%) patients, out of 260 who were regularly followed up (26 were lost). Local recurrence alone was found in 21 (8.0%) patients, while distant spread was registered in 22 (8.46%) patients. Local and distant spread was found in 4 (1.5%) cases. At present, the median follow-up is at 54 months. Analysis by the Kaplan-Meier's test shows cumulative survival of 66% at 71 months of the follow-up. Seventy four percent of patients with curative operations exhibit no signs of recurrence at 5 years.

Adenocarcinoma↗
PubMed2000

The role of overlapping sphincteroplasty in traumatic fecal incontinence.

Fecal incontinence is one of the most distressing conditions. Even there is a great variety of etiologic factors, they can be systematized in two main categories; fecal incontinence with normal and fecal incontinence with abnormal function of pelvic floor muscles. The latter is more interesting for surgeons since this category includes the great majority of surgically caused and surgically correctable fecal incontinences. Disruption of the anal sphincter caused by obstetric injury, anorectal operations or external trauma is the commonest cause of fecal incontinence. In the period 1990-1999, 53 patients with fecal incontinence caused by sphincter injury were treated on the third department for colorectal surgery, First Surgical Clinic. There were 43 females and 10 males with a mean age of 36.1 years (range 18-64). Causes of fecal incontinence were: obstetric trauma 38 patients. (71%), fistulotomy 9 (17%), war injuries 3 (6%) and nonspecific 3 (6%). The severity of incontinence was graded by Browning--Parks's classification. There were no patients in group A and B, in group C were 11 patients and in D group 37 patients. Wexner score system was also utilized preoperatively and postoperatively to determine continence function more precisely. Clinical exam, anoscopy and special investigations, such as anal manometry, EMG and defecography were carried out in all cases. Period between injury and repair was between 6 months and 20 years. Severe pudendal neuropathy was present in 17 patients. Five patients had oostomies performed at the time of injury. In three cases was present traumatic cloaca and in one case rectovaginal fistula. Overlapping sphincter repair technique was carried out in all cases. Full bowel preparation and antibiotics were prescribed. Anterior sphincteroplasty was performed in 39 cases, lateral in 7, posterior in 3 and anterior sphincteroplasty + posterior plication of puborectalis (Parks operation) in 4 patients. Protective colostomy was not performed in any case. The outcome of the procedure was considered as excellent, good, fair and poor (excellent when full control of solid and liquid stool and flatus was achieved, good when there was continence to feces but not to flatus, fair when patients could control only solid feces and poor when only partial control of solid feces was obtained). The overall functional results were as follows: Excellent in 25 patients (47.2%), good in 12 (22.7%), fair in 11 (20.7%) and poor in 5 (9.4%). Wound infection occurred in 9 (16.9%) patients, leading to disruption of sutures in three patients with consequent poor results. Two of them were reoperated. The duration of follow-up was from 5 to 60 months. We conclude that an overlapping sphincteroplasty is a method of choice in treating fecal incontinence caused by trauma. The best results are achieved with anterior sphincteroplasty. Results of posterior sphincteroplasty were disappointing. If present, pudendal neuropathy directly influences the outcome of sphincteroplasty. Manometric studies correlate with the clinical outcome.

Adolescent↗
PubMed1999

Clinical evaluation of the bionic glove.

OBJECTIVE: Clinical evaluation of the Bionic Glove, a prototype of a new functional electrical stimulation device designed to improve the function of the paralyzed hand after spinal cord injury. PATIENTS: Twelve people with spinal cord injury at C5-C7 who had used the device 6 months or more. SETTING: Measurements were made at the Institute "Dr Miroslav Zotović" in Belgrade as a part of a multicenter clinical trial. METHODS: Measures include Upper Extremity Function Test, Functional Independence Measure, and Quadriplegia Index of Function. RESULTS: The daily use of a Bionic Glove had two major effects: (1) increasing the power grasp; and (2) increasing the range of movements. Active force was significantly greater than passive tenodesis force, as shown in other studies. Most manual tasks improved significantly with the use of the assistive system, as judged by the time needed to complete a task or the subject's qualitative ratings of a task difficulty. Most subjects who retained some dexterity without the assistive system hesitated to use the assistive system to manipulate small objects. CONCLUSION: The Bionic Glove can significantly improve independence in people with C5-C7 spinal cord injury if their initial Functional Independence Measure and Quadriplegia Index of Function scores are 20% to 50% of the maximum values.

Activities of Daily Living↗
PubMed1999

The activity of liver oxidative enzymes after single and multiple grapefruit juice ingestion.

In the recent time, several in vitro and in vivo studies have shown the inhibitory effect of grapefruit juice on metabolism of xenobiotics catalyzed by liver oxidative enzymes including cytochrome P450 izoenzymes. However, all these experiments were done with a single dose of grapefruit juice. The primary aim of this study was to evaluate if the chronical ingestion of grapefruit juice can cause enzyme activity alteration as well as a single dose. Three groups of male mice were used: the control group, the group which was administered 0.2 mL of grapefruit juice per os 10 days and the group which was administered single dose of 0.5 mL grapefruit juice per os 90 min. before the sacrificing. After the sacrificing of animals, liver was homogenized with appropriate buffer, and the activity of oxidative liver enzymes: xanthine oxidase (XOD), peroxidase (Px), catalase (CAT), lipid peroxidase (LPx), glutathion peroxidase (GSH-Px) and liver glutathion contents (GSH) were detected by standard methods. The results show that the enzyme activity of liver MFO was changed according to a single or multiple grapefruit juice ingestion. The grapefruit juice in a single oral dose significantly decreases the activity of xanthine oxidase, glutathion peroxidase, lipid peroxidase and liver glutathion contents, and has no effect on activity of catalase and peroxidase. The multiple grapefruit ingestion increases the activity of XOD, GSH-Px, LPx, Px and GSH, while the activity of CAT enzyme is unchanged. The chronical and single grapefruit ingestion has no effect on relative liver weight, but the liver protein content is significantly decreased after the multiple oral grapefruit juice ingestion.

Animals↗