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Biomedical subjects

V Ivanova

Publications and source records attributed to V Ivanova.

At least 19 recordsLinked to original sources
PubMed2006

Total versus subtotal hysterectomy for benign gynaecological conditions.

BACKGROUND: Hysterectomy using an abdominal approach removes either the uterus alone (subtotal hysterectomy) or both the uterus and the cervix (total hysterectomy). The latter is more common but outcomes have not been systematically compared. OBJECTIVES: To assess and compare outcomes with subtotal hysterectomy versus total abdominal hysterectomy for benign gynaecological conditions. SEARCH STRATEGY: We searched the Cochrane Menstrual Disorders and Subfertility Group's specialised register of controlled trials (December 2005), Central (December 2005), Medline (1966 to December 2005), EmBase (1980 to December 2005), Biological Abstracts (1980 to December 2005), the National Research Register and relevant citation lists. SELECTION CRITERIA: Only randomised controlled trials of women undergoing either total or subtotal hysterectomy for benign gynaecological conditions were included. DATA COLLECTION AND ANALYSIS: Three trials that included 733 participants were included. Independent selection of trials and data extraction were undertaken by 2 reviewers and results compared. MAIN RESULTS: There was no evidence of a difference in the rates of incontinence, constipation or measures of sexual function. In one unblinded trial, a significantly greater proportion of women indicated that they had frequent episodes of urinary incontinence after subtotal hysterectomy when compared with total hysterectomy (OR=2.1, 1.02 to 4.3), but these results were not confirmed by the other two trials that measured both stress and urge incontinence and urinary frequency. . Length of surgery and amount of blood lost during surgery were significantly reduced during subtotal hysterectomy when compared with total hysterectomy, but there was no evidence of a difference in the odds of transfusion. Febrile morbidity was less likely (OR=0.43, 0.25 to 0.75) and ongoing cyclical vaginal bleeding one year after surgery was more likely (OR=11.3, 4.1 to 31.2) after subtotal when compared with total hysterectomy. There was no evidence of a difference in the rates of other complications, recovery from surgery or readmission rates. AUTHORS' CONCLUSIONS: This review has not confirmed the perception that subtotal hysterectomy offers improved outcomes for sexual, urinary or bowel function when compared with total abdominal hysterectomy. Surgery is shorter and intraoperative blood loss and fever are reduced but women are more likely to experience ongoing cyclical bleeding up to a year after surgery with subtotal hysterectomy compared to total hysterectomy.

Blood Loss, Surgical↗
PubMed2005

Effects of nutrients on the production of AK-111-81 macrolide antibiotic by Streptomyces hygroscopicus.

The influence of different carbon and nitrogen sources on the production of AK-111-81 nonpolyenic macrolide antibiotic by Streptomyces hygroscopicus 111-81 was studied. Substitution of glucose with lactose or glycerol significantly affected maximal antibiotic AK-111-81 productivity as the growth rate was close to that of the basal fermentation medium. Addition of ammonium succinate to the fermentation medium markedly increased the antibiotic productivity as the growth rate was low. Divalent ions as Mn2+, Cu2+, Fe2+ stimulated AK-111-81 antibiotic biosynthesis. These results allow us to develop a new fermentation medium showing 6-fold increase of AK-111-81 antibiotic formation compared with the basal fermentation medium.

Anti-Bacterial Agents↗
PubMed2004

[Histological analysis of endometrial polyps in breast cancer patients treated with tamoxifen (nolvadex)].

Endometrial polyps are the most common endometrial pathology described in association with Tamoxifen exposure. The aim of this study was to evaluate the malignant potential of endometrial polyps in breast cancer patients receiving Tamoxifen. We analyzed 140 endometrial polyps divided into two groups: 1) 73 endometrial polyps from 57 breast cancer patients receiving Tamoxifen (Nolvadex): T+ endometrial polyps; 2) 67 control endometrial polyps received for analysis in the period January-December 2000. The analysis was performed on archival H&E sections. We found that the rates of endometrial carcinoma and atypical hyperplasia were high in patients treated with Tamoxifen (7.02% vs 2.99% and 17.54% vs 11.94%), but the results did not reach statistical significance (p > 0.05).

Antineoplastic Agents, Hormonal↗
PubMed2003

[Pathology of the endometrium in breast cancer patients treated with tamoxifen (nolvadex)].

The objectives of this study were to: 1) characterize histologically endometrial biopsy findings for genital bleeding in breast cancer patients receiving Tamoxifen; 2) analyze histologically endometrial carcinoma in the same patients. We analyzed biopsy specimens divided into three groups: 1) 112 biopsies (curettages and hysterectomy specimens) from 88 breast cancer patients receiving Tamoxifen (Nolvadex): T+; 2) 27 biopsies (curettages and hysterectomy specimens) from 22 breast cancer patients not receiving Tamoxifen but biopsied for genital bleeding: T-; 3) 139 curettages control samples received for analysis in the period January-March 2000 from women with peri- and postmenopausal genital bleeding: K. The analysis was performed on archival H&E sections. The most frequent finding in breast cancer patients receiving Tamoxifen was endometrial polyp. Compared with the other two groups (T- and K) the frequency of this finding was statistically significant. No difference was found in the prevalence of endometrial cancer between the three groups. The analyzed endometrial carcinomas in Tamoxifen-treated breast cancer patients show signs, characteristic of Bochman type I: predominantly endometrioid, of low grade and FIGO stage, with good prognosis.

Antineoplastic Agents, Hormonal↗
PubMed2001

Transformation-associated recombination (TAR) cloning of tumor-inducing Xmrk2 gene from Xiphophorus maculatus.

We modified the TAR methodology of YAC clone construction for application to fish genomic DNA isolated from Xiphophorus maculatus. YAC libraries were developed using the XIR1 repeat sequence as the recombinational hook. Construction of these libraries demonstrates that Xiphophorus DNA sequences can function as hooks in the yeast recombination system and that X. maculatus genomic DNA contains sequences that provide origin of replication function in yeast. By screening a subset of Xiphophorus YAC clones, we isolated a clone harboring the Xmrk2 locus that is associated with spontaneous and induced melanomagenesis. Modifications of the TAR technique allowed the targeted cloning of specific genes from genomic regions ranging in size from cDNAs to several hundred kilobases. Specific genomic regions can be isolated in a directional manner from fixed map locations to saturate these areas with physical markers. We discuss the applications of these and other yeast recombinational processes to fish genetics.

Journal Article↗
PubMed2001

Simultaneous biosynthesis and purification of two extracellular Bacillus hydrolases in aqueous two-phase systems.

Thermostable alpha-amylase with temperature optimum at 80 degrees C, molecular mass 58 kDa and pI point 6.9 was purified from a catabolite resistant Bacillus licheniformis strain. The enzyme was sensitive to inhibition by metal ions and N-bromosuccinimide. The partition behaviour of this enzyme in aqueous two-phase systems (ATPS) of the polymer-polymer-water type was investigated and some effects of type, molecular weight and concentration of phase components were studied. Up to 100% retention in the bottom phase of polyethylene glycol 10,000-20,000/dextran 200 system was reached. Best partition conditions were obtained in PEG 10,000-20,000/polyvinyl alcohol 200 systems, where the partition coefficient K increased 750 times to 7.5. Simultaneous production and purification of alpha-amylase and serine proteinase in PEG-polymer-water ATPS were examined. In the system PEG 6,000/ficoll, up to 90% of the amylase was retained in the bottom phase, whereas about 95% of the total protein (K = 22.8) and 60-75% of the proteinase were in the top phase. Similar separation of the enzymes from laboratory supernatant was obtained in system PEG/Na2SO4.

Bacillus↗
PubMed2001

[Umbilical metastasis - "Sister Joseph's nodule" of an endometrial adenocarcinoma: a case report and review of the literature].

The umbilical metastatic lesions have been termed the "Sister Joseph nodule" by Sir Hamilton Bailey in 1949. SJN is an important diagnostic finding, as it often is the first clue and sometimes the only physical indication of an advanced intra-abdominal malignancy. SJN is most often associated with malignancy of the stomach or ovary. It usually appears late in the course of neoplastic disease and suggests a poor prognosis. In our review of English language medical literature we could find only 27 reports of SJN in endometrial adenocarcinoma. We offer a case of SJN, presenting as umbilical hernia, in a female patient, who, 12 years previously, had undergone laparotomy with total hysterectomy and bilateral salpingo-oophorectomy for endometrial adenocarcinoma. Three years after the surgical excision of the umbilical lesion, the patient underwent surgery for a tumor located subcutaneously in the suprapubic area. Histologically, in the samples obtained with both surgical interventions, endometrioid adenocarcinoma with squamous differentiation was found. The clinical examination and imaging studies found no evidence of other metastases. On the basis of clinico-pathological analysis we offer a hypothesis about development of metastases and discuss their prognostic significance.

Adenocarcinoma↗
PubMed2000

Specificity of a neutral Zn-dependent proteinase from Thermoactinomyces sacchari toward the oxidized insulin B chain.

The proteolytic specificity of the neutral Zn-dependent proteinase from Thermoactinomyces sacchari was determined by analysis of the peptides obtained after incubation with the oxidized insulin B chain as a substrate. The enzyme is an endopeptidase with broad specificity. In total, 12 peptide bonds in the B chain of insulin were hydrolyzed. The major requirement is that a hydrophobic residue such as Leu, Val, or Phe should participate with the alpha-amino group in the bond to be cleaved. However, hydrolysis of bonds at the N-terminal side of His, Thr, and Gly was also observed. The peptide bond Leu 15-Tyr 16 in the oxidized insulin B chain, which is the major cleavage site for the alkaline microbial proteinases, is resistant to the attacks of the enzyme from Thermoactinomyces sacchari and other neutral proteinases. The proteolytic activity of the Zn-dependent proteinase from T sacchari is different from those of other metalloendopeptidases from microorganisms.

Amino Acid Sequence↗
PubMed1999

Role of poly(ADP-ribose) polymerase (PARP) cleavage in apoptosis. Caspase 3-resistant PARP mutant increases rates of apoptosis in transfected cells.

An early transient burst of poly(ADP-ribosyl)ation of nuclear proteins was recently shown to be required for apoptosis to proceed in various cell lines (Simbulan-Rosenthal, C., Rosenthal, D., Iyer, S., Boulares, H., and Smulson, M. (1998) J. Biol. Chem. 273, 13703-13712) followed by cleavage of poly(ADP-ribose) polymerase (PARP), catalyzed by caspase-3. This inactivation of PARP has been proposed to prevent depletion of NAD (a PARP substrate) and ATP, which are thought to be required for later events in apoptosis. The role of PARP cleavage in apoptosis has now been investigated in human osteosarcoma cells and PARP -/- fibroblasts stably transfected with a vector encoding a caspase-3-resistant PARP mutant. Expression of this mutant PARP increased the rate of staurosporine and tumor necrosis factor-alpha-induced apoptosis, at least in part by reducing the time interval required for the onset of caspase-3 activation and internucleosomal DNA fragmentation, as well as the generation of 50-kilobase pair DNA breaks, thought to be associated with early chromatin unfolding. Overexpression of wild-type PARP in osteosarcoma cells also accelerated the apoptotic process, although not to the same extent as that apparent in cells expressing the mutant PARP. These effects of the mutant and wild-type enzymes might be due to the early and transient poly(ADP-ribose) synthesis in response to DNA breaks, and the accompanying depletion of NAD apparent in the transfected cells. The accelerated NAD depletion did not seem to interfere with the later stages of apoptosis. These results indicate that PARP activation and subsequent cleavage have active and complex roles in apoptosis.

Apoptosis↗
PubMed1998

N'-methylniphimycin, a novel minor congener of niphimycin from Streptomyces spec. 57-13.

A novel natural niphimycin analog, N'-methylniphimycin was isolated from the culture broth of the Streptomyces spec. 57-13. The chemical constitution was elucidated from the physico-chemical properties, NMR techniques and mass spectrometry to be a 36-membered macrolide related to azalomycin F5a, shurimycin B and RS-22C. N'-methylniphimycin displayed moderate activity against some yeasts and filamentous fungi.

Antifungal Agents↗
PubMed1997

New macrolactone of the desertomycin family from Streptomyces spectabilis.

The non-polyenic macrocyclic antibiotic complex 1012 was isolated from the culture broth of a strain Streptomyces spectabilis 1. The complex was found to belong to the desertomycin complex. Three main compounds of complex 1012 were separated and purified by preparative chromatographic methods. The identification was performed by UV, IR, NMR and mass-spectrometric studies. It was proved that two of the compounds with MW. 1191, C61H109NO21 and MW. 1190, C61H106O22 were identical to desertomycin A and D. The other com-pound with MW.1028, C55H96O17 is new macrolactone, named deser-tomycin E. The structures were established by detailed spectroscopic analysis.

Anti-Bacterial Agents↗
PubMed1997

Power spectral electroencephalogram analysis of the effects of ritanserin in freely moving rats during quiet waking.

Changes in the spectral characteristics of the Fast Fourier Transformed (FFT) electroencephalogram (EEG) recorded from the frontal cortex of freely moving rats during quiet waking were studied after blockade of the 5-hydroxytryptamine-2 (5-HT2) receptors by the potent and long acting 5-HT2 antagonist ritanserin administered intraperitoneally (i.p.) at two doses (0.63 and 2.5 mg/kg). The rationale of this approach was to evaluate the subtle ritanserin-induced changes in the EEG in the frequency domain, and thus obtain more information about the neurophysiological effects mediated by brain 5-HT2 receptors and about the mechanisms underlying ritanserin's ability to increase sleep at the expense of wakefulness. Ritanserin induced significant changes in the power spectrum of EEG recorded from the frontal cortex. The activation index (the ratio of the dominant frequency in the power spectrum to the total power) significantly decreased after ritanserin, which was due to the increased EEG power in all frequency bands (except for beta 2) and to the decreased dominant frequency in the EEG spectrum, suggesting ritanserin-reduced EEG activation during quiet waking. The results favor the view of the excitatory modulating action of serotonin mediated via cortical 5-HT2 receptors and suggest that ritanserin could cause a faster transition from waking to sleep.

Animals↗
PubMed1996

Performance of a magnetically stabilized bed reactor with immobilized yeast cells.

This paper is focused on the possibility to apply the magnetic stabilization technique in bioprocessing. The feasibility of a continuous ethanol fermentation process with immobilized Saccharomyces cerevisiae cells in a magnetically stabilized bed (MSB) was demonstrated. The fermentation processes were carried out in an external magnetic field, transverse to the fluid flow. The flexibility to change the bed expansion owing to the independent change of the fluid flow and the field intensity (the "magnetization FIRST" mode) permitted the creation of fixed beds with different particle arrangements, which affected the bed porosity, the effective fluid-particle contact area, and the mass transfer processes on the particle-fluid interface. As a result, higher ethanol concentration, ethanol production, and glucose uptake rates than in conventional packed bed reactor were reached.

Biotechnology↗
PubMed1995

Effector-induced dissociation of glyceraldehyde-3-phosphate dehydrogenase discriminated by urea solvation.

The dissociation of glyceraldehyde-3-phosphate dehydrogenase (GAPD) from pig muscle in water solutions (0.1 M phosphate, pH 7) at increased urea concentrations was studied by means of frontal-gel chromatography, intrinsic (TRP) fluorescence, differential absorption spectroscopy and selective chemical modification at TRP0193. The results are in agreement with a consecutive two-step model of dissociation of the tetramer and the dimer (C*T = 0.42 M urea < C*D = 1.39 M urea). The binding effector(s) destabilizes the oligomeric structures (delta GT changes from -1.00 to -0.54 kcal/mol; delta GD from -2.30 to -1.22 kcal/mol). The introduction of the bulky Koshland-reagent group to TRP-193 at the subunit-subunit interface leads to a decrease of the stability with delta delta G approximate to 1 kcal/mol, owing to TRP-193...TYR-39...TYR-92 cluster destruction. By using lobster GAPD atomic coordinates (PDB file 1GPD) and pig muscle GAPD amino-acid sequence, a tentative molecular model was constructed and the subunit contacts in terms of the Lee-Richard static accessibilities were described. A detailed analysis of the dissociation as a transfer of the buried residues from the molecular interface to the urea solutions was performed.

Animals↗