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Biomedical subjects

I Iliev

Publications and source records attributed to I Iliev.

At least 19 recordsLinked to original sources
PubMed2001

[Biliary peritonitis: retrospective analysis of the disease].

The authors have done a biliary retrospective analysis of 10 deceased patients with a diagnosis of biliary peritonitis (BP). It is reported that the patients who died of BP are 9.5% of all who died of diffuse purulent peritonitis. All deceased patients were advanced and well advanced in years with prolonged complaints--in over 50% of them over 5 years. The complications set in 50% of the cases are recorded in the postoperative period. The perforation of the gallbladder and the biliopancreatitis are in the second place. Intrabiliary fistulas with 4 patients and 1 with a vesicocolon fistula; tumor of the pancreas with 4 patients; empyema of the gallbladder--3; diabetes with 3 of the patients and others are recorded as accompanying troubles which complicate the operation and the outcome of it. The time between the beginning of the complication and the operation with all the deceased patients is over 72 hours.

Aged↗
PubMed2001

A study of extracellular inulinase activity in strains of genus Kluyveromyces.

Fructo-oligosaccharide represent one of the major classes of bifidogenic oligosaccharides in term of their production volume, because of their favorable functional properties. These include: a/ improving the intestinal microflora; b/ relieving the constipation; c/ decreasing the total cholesterol and lipid in serum; d/ the promotion of animal growth and e/ as low calorie non-cariogenic sweeteners (Chen and Liu, 1996). FOS are manufactured by two differing processes which result in slightly different end products--using either microbial fructosyl transferase (EC 2.4.1.9) or beta-fructofuranosidase (EC 3.2.1.26) with high transfructosylation activity. The present study reports on the biosynthesis of an extracellular inulinase by yeasts from genus Kluyveromyces. The strains were isolated from different dairy products. Some of the studied strains produced large amounts of extracellular inulinase activity when grown on inulin ar sucrose as carbon source. In addition, the effect of C/N ratio on the production of extracellular inulinase was studied. Thin layer chromatography showed that inulinase from K. species 19 was capable of hydrolyzing inulin, releasing monosaccharides and oligosaccharides.

Cathartics↗
PubMed2001

Biosynthesis of exopolysaccharides by two strains of Lactobacillus bulgaricus in whey-based media.

Exopolysaccharides /EPS/ produced by lactic acid bacteria /LAB/ play a role in the rheology and texture of fermented milks (Cerning 1990) and could also provide a new source of safe additives for use in various food products. The physical properties of EPS, such as rheology and behaviour, depend on several factors, including sugar composition, type of sugar linkages, the presence of organic or inorganic substituents, the degree of polymerization and the length of the side chains. On the other hand certain physiological properties of lactic bacteria are of particular importance in the mechanism of their probiotic functioning: metabolism leading to accumulation of organic acids and other fermentation products in the media; resistance to those metabolites; competitive assimilation of the major nutrients of the media. The significant antimicrobial effect of probiotics towards pathogens and potentially pathogenic microorganisms is outlined in this context. This study was conducted on LAB strains with experimentally established preventive effect in control of chemical carcinogenesis induced by dimethylhydrazine, heavy metals and nitrites. The present study reports the biosynthesis of EPS by strains with proved anticancer effect Lactobacillus bulgaricus LB3 and Lactobacillus bulgaricus LBs on whey-based media. A study on the action of different nitrogen sources (yeast extract and peptone) on the productivity of EPS and the rheological properties of medium was done. When whey-based medium was used the highest production of EPS was determined at 1% peptone--145 mg/g(-1). The carbohydrate substrate influenced the EPS composition. Not only the concentration but also the structure of the EPS is important for its thickening effect. The functional properties of the EPS produced could be modified by influencing the growth conditions. The influence of the different content of glucose on the fermentation process and the viscosity of the whey was performed.

Culture Media↗
PubMed2001

Identification of whey proteins in tradional Bulgarian yougurt.

Functional foods hold a great promise for future trends in human nutrition. Consumption of milk and milk products have a pronounced probiotic effects together with the expected modification of allergenic properties of milk due to the process of fermentation. The proteolytic system of lactic acid bacteria consists a cell wall bound proteinase and several intracellular peptidases, and can contribute to the liberation of bioactive peptides. Food-derived bioactive peptides are claimed to be health enhancing components which can be used for functional food. In our study we focused our attention on beta-lactoglobulin and alpha-lactalbumin in early stages of yogurt fermentation of traditional Bulgarian products. Biochemical techniques were used to measure the concentration of these two whey proteins during fermentation. At a result of the done study alteration in the concentration of beta-lactoglobulin and alpha-lactalbumin were detected. The studied proteolytic activity of the strains, used in the fermentation process confirmed the received results.

Fermentation↗
PubMed2000

A 15-year longitudinal follow-up study of heart rate and heart rate variability in healthy elderly persons.

BACKGROUND: Few researchers have conducted heart rate (HR) studies in healthy very elderly subjects aged 70 years or older, and there are no longitudinal follow-up studies in this population. The objective of this study was to evaluate long-term changes in HR and heart rate variability (HRV) with aging in healthy elderly persons by means of comparison between two Holter monitor recordings obtained at an interval of 15 years. METHODS: The study population consisted of 15 healthy elderly persons (10 women and 5 men) aged 64 to 80 years (mean 70 +/- 4.1) at the first recording, and 79 to 95 years old (mean 85 +/- 4.1 years) at the second recording 15 years later. Nighttime (midnight to 5 AM) and daytime (noon to 5 PM) HR and HRV were obtained, and paired t tests were performed to assess the differences in each parameter of nighttime and daytime HR and HRV between the two (15-year interval) Holter monitor recordings. RESULTS: The results of the t-test comparisons were as follows: there was a significant increase in minimal, maximal, and average HRs (nighttime, p < .01; daytime, p < .05, respectively). On the other hand, with regard to HRV, there was a significant nighttime decrease in the SDNN index (mean of standard deviations of normal RR intervals between adjacent QRS complexes resulting from sinus node depolarizations for all 5-minute segments) (p = .0086), and a significant daytime increase in the NN50 (number of adjacent normal RR intervals >50 milliseconds) per hour (p = .0425). Moreover, there was a significant decrease in the low-frequency (LF) component (nighttime, p = .0151; daytime, p = .0032), and a significant decrease in the LF/HF ratio (nighttime, p = .0270; daytime, p = .0371), but there was no significant change in the nighttime or daytime high-frequency (HF) component. CONCLUSIONS: HR increased with age over the 15-year period in the healthy elderly persons. As for concurrent changes in HRV, however, the parameters of sympathetic modulation decreased, and the parameters of parasympathetic modulation were unchanged or slightly increased.

Aged↗
PubMed2000

Radiofrequency catheter ablation of a concealed atrioventricular accessory pathway associated with a coronary sinus diverticulum.

A 31-year-old woman underwent radiofrequency catheter ablation of a concealed left posteroseptal accessory pathway associated with a coronary sinus diverticulum. The patient had previously undergone unsuccessful catheter ablation of the posteroseptal region of the mitral annulus. Coronary sinus venography revealed the presence of the diverticulum near the ostium. An electrogram in the neck of the diverticulum showed the shortest ventriculoatrial conduction time and a large accessory pathway potential during atrioventricular reciprocating tachycardia. The pathway was successfully ablated within the neck of the diverticulum. The findings in this case underscore the importance of coronary sinus venography before ablation.

Adult↗
PubMed1999

Proteolytic activity in relation to seasonal cambial growth and xylogenesis in Pinus banksiana.

Proteolytic activity in the cambial zone and developing xylem of Pinus banksiana Lamb. was investigated over an annual cycle of growth and dormancy. Highest proteolytic activity was associated with the most active period of primary-wall radial expansion of cambial derivatives, in early spring, before protoplasmic autolysis was initiated in developing earlywood. Three pH maxima of proteolytic activity, near pH 3.0, 6.5 and 9.5, were observed at that time. In general, activities measured at pH values below 7.0 were greater than those determined above pH 7.0 at all stages in the annual cycle, in both cambial zone and developing xylem, although elevated activity at alkaline pH was also observed during springtime growth. Polyvinylpolypyrollidone (PVP) treatment markedly enhanced pH 7.5 but not pH 4.0 proteolytic activity in the cambial zone, but not in developing xylem, indicating the presence of PVP-binding proteinase regulators in the cambium. By fractionation and effector studies total proteolysis was determined to comprise interactions between serine, cystine, aspartate and metallo-proteases having MWs, by gel chromatography, between 10 and 100 kDa. The observations point to a complex regulatory mechanism controlling the presence and catalytic rates of the distinct types of proteases in the cambial region throughout an annual cycle of growth and dormancy.

Cycadopsida↗
PubMed1999

[Mucinous breast carcinomas with neuroendocrine differentiation].

Mucinous breast carcinomas, denominated also gelatinous, mucoid and colloid (collomas), represent a heterogeneous group of neoplasms. More than half of them exhibit signs of neuroendocrine differentiation. Eighteen mucus producing carcinomas of the breast are subjected to morphological study. On the ground of demonstrating argyrophilia by the methods of Grimelius and Churukian--Shenk, and presence of secreting granules during electron microscopic study, they are assigned under the heading apudomas, i.e. tumors of the diffuse endocrine system, or the so-called APUD-system. The important practical implications of demonstrating neuroendocrine cells with a special reference to the biological patterns of this particular type of tumors are discussed.

Adenocarcinoma, Mucinous↗
PubMed1999

[Tumors of the appendix].

Neoplasms involving the vermiform outgrowth are among the rarely met with conditions, accounting for 0.1 to 0.5 per cent of all gastrointestinal tract tumors. This is a report on personal observation of three patients presenting tumors of the appendix, diagnosed over the period 1987 to 1995. As shown by the results, tumors of the appendix run a clinical course characterized by two distinct forms: clinical picture of acute appendicitis--two cases, and clinical picture of tumor of the colon--one case. It is underscored that intraoperative diagnosis is extremely difficult. The diagnosis is usually made by pathoanatomist, while the therapeutic approach and operative tactics are determined on the ground of histomorphological study results and local operative status. The scope of operative intervention includes appendectomy and right hemicolectomy.

Adult↗
PubMed1998

Quantitative electroencephalographic changes due to middle cerebral artery occlusion by endothelin 1 in conscious rats.

The powerful vasoconstrictor peptide endothelin-1 (ET1) has been shown to reduce local cerebral blood flow in brain areas supplied by the middle cerebral artery (MCA) to a pathologically low level upon intracerebral injection adjacent to the MCA. This reduction manifests itself as an ischemic infarct, that is fully developed within 3 days after ET1 injection. The aim of the present study is to examine the effect of ET1 on electroencephalographic (EEG) activity. ET1 was microinjected unilaterally at a dose of 60 pmol in 3 microl of saline to the MCA in conscious rats. EEG signals were recorded from the frontoparietal cortical area, supplied by MCA, from the first up to the fourteenth day after ET1 injection. EEG activity was analyzed by the fast Fourier transformation. A significant shift to a lower EEG frequency, i.e., augmentation of slow waves and a reduction of alpha-like and faster EEG waves was found post-ET1. This effect was maximal after 3-7 days when the most severe destruction of neurons in this cortical area occurs, as has been previously demonstrated. The results suggest that the quantitative EEG analysis may provide useful additional information about the functional disturbances associated with focal cerebral ischemia.

Animals↗
PubMed1998

Results of treatment of trigeminal neuralgia by microvascular decompression of the Vth nerve at its root entry zone.

Eighty five patients suffering from trigeminal neuralgia resistant to medical therapy underwent surgical treatment for relief of pain at the Department of Neurosurgery University Alexander Hospital Sofia from 1981 until 1997. Microvascular decompression at the root entry zone of the V(th) nerve has been performed using the technique of Jannetta. The operative exploration of the parapontine root entry zone disclosed neurovascular conflicts in 87.1% of the cases. They represented displacement and/or distortion, sometimes pressure grooves, discoloration, altered vascularity of the V(th) nerve. The analysis of early postoperative results have shown an excellent outcome in 90.6% of the cases, good in 3.5% and poor in 2.4% with mortality of 3.5% early in these series when no postoperative monitoring was available. The follow up study one year after surgery revealed 90.2% excellent and 3.7% good results and poor outcome and recurrences in 6.1% of the cases. Patients with long lasting trigeminal neuralgia, previous destructive procedures, venous compression, lack of convincible evidences for neurovascular conflicts had less favorable outcome or recurrences. In the last years partial sensory rhizotomy was performed in cases when no neurovascular conflicts were found out. Patients with unquestionable arterial compression leading to displacement associated with distortion and pressure grooves had excellent outcomes. Early recurrences were associated with missed pathology at the entry zones. During reexplorations for late recurrences new arterial compression was found in less than half of the cases.

Adult↗
PubMed1998

[Abnormalities of electrocardiographic P wave morphology and the relationship to electrophysiological parameters of the atrium in patients with idiopathic paroxysmal atrial fibrillation].

In 39 patients with idiopathic paroxysmal atrial fibrillation (PAF group), the incidence of the abnormal P wave morphology (prolonged P wave and mitral P in lead II and increased P terminal force in lead V1: PTF V1) was examined, and the relationships to the electrophysiologic findings of the atrial muscle were investigated. The control group consisted of 42 patients with various cardiac arrhythmias other than sick sinus syndrome. P wave duration was significantly longer in the PAF group than in the control group (112 +/- 12 vs 98 +/- 10 msec, p < 0.0001). PTF V1 was greater in the PAF group than in the control group (0.051 +/- 0.018 vs 0.028 +/- 0.010 msec, p < 0.0001). P mitrale occurred in only 5 patients (12%) in the control group as compared to 25 patients in the PAF group (64%, p < 0.0001). The longest duration of the right atrial electrograms was longer in the PAF group than in the control group (101 +/- 17 vs 85 +/- 10 msec, p < 0.0001), as was the maximal number of the fragmented deflections (8.0 +/- 2.5 vs 5.8 +/- 1.4, p < 0.0001). Repetitive atrial firing zone and also fragmented atrial activity zone were longer in the PAF group than in the control group (34 +/- 24 vs 12 +/- 19 msec, p < 0.02 and 47 +/- 27 vs 24 +/- 19 msec, p < 0.001, respectively). Interatrial conduction delay zone was longer in the PAF group than in the control group (55 +/- 25 vs 38 +/- 18 msec, p < 0.001). P wave duration and PTF V1 had significant and/or borderline correlations with the longest duration of the right atrial electrocardiograms (r = 0.75, p < 0.0001 and r = 0.68, p < 0.0001, respectively), and the maximal number of its fragmented defections (r = 0.50, p < 0.002 and r = 0.40, p < 0.05, respectively). Furthermore, P wave duration had a correlation with the repetitive atrial firing zone (r = 0.55, p < 0.01). Prolonged P wave duration and increased PTF V1 are electrocardiographic indicators for the coexistence of electrophysiologic abnormalities in patients with idiopathic paroxysmal atrial fibrillation.

Adult↗
PubMed1995

[The surgical reconstruction of the chest wall using muscle flaps in patients with mediastinitis following heart operations].

An assessment is made of the results of plastic closure of the chest in cases presenting mediastinitis. The analysis covers nineteen patients with a history of mediastinitis following open-heart surgery, treated by the same method of plastic reconstruction of the chest. The technique of plastic closure of the chest using a rotation muscle flap (pectoralis and right rectus abdominis muscles) is described.

Bacterial Infections↗
PubMed1992

Glucose biosensor based on carbon black strips.

Amperometric biosensors for the determination of beta-D-glucose have been constructed. They were based on a porous matrix of carbon blacks--'Ketjenblack' (KB) and 'Shawinigan black' (SB) wet-proofed with polytetrafluorethylene. Glucose-sensitive elements were prepared by subsequent adsorptional immobilization of 1,1'-dimethylferrocene (DMFc) and nickel-ocene (Nc) on 'Shawinigan black' or tetracyanoquinodimethane (TCNQ) on 'Ketjenblack' together with Penicillium chrysogenum glucose oxidase. Maximum surface concentrations of DMFc, Nc and TCNQ on carbon black electrodes were 95, 116 and 151 nmol cm-2. The biosensor based on KB and TCNQ (KB-TCNQ biosensor) could be used at a potential of 0.5 V (vs. Ag/AgCl reference electrode) in the concentration range up to 7 mM. This biosensor possessed an approximately ten times higher sensitivity than the ones based on SB and DMFc (SB-DMFc biosensor) and on SB and Nc (SB-Nc biosensor) which acted at 0.3 V and 0.05 V, respectively. The biosensors were suitable for practical use longer than one week.

Biosensing Techniques↗
PubMed1989

[Indices of a threatened pregnancy in the first trimester].

Studies were carried out on 167 pregnant women, divided into 4 groups in accordance with the values of human chorionic gonadotropin (HCH). Fetal death was established by ultrasound in 41 of the pregnant women including all cases with HCG under 5000 IU, but it was also found in 19.18% of women with values of HCG over 10,000 IU. Pregnancy advanced unfavourably in other 16 pregnant women of altogether in 34.13%. Prognosis was unfavourable in the presence of decidual hematoma. The gestational sac was enlarged on the average. 1.3 mm per day in normal development. Treatment was made in two groups: with hormones, spasmolytics and vitamins and only with spasmolytics and vitamins. The results showed that progesterone preparations, used singly or in combination with estradiol, did not improve the results.

Chorionic Gonadotropin↗