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Biomedical subjects

I V Popova

Publications and source records attributed to I V Popova.

At least 19 recordsLinked to original sources
PubMed2005

Energetics of alkalophilic representatives of the genus Bacillus.

Cytochrome and lipid composition of membranes is considered as the attributes required for adaptation of the alkalophiles to alkaline conditions. Respiratory chains of alkalophilic representatives of the genus Bacillus are discussed. Special attention is paid to the features of the Na(+)-cycle of these bacteria and to the features determining halo- and alkalotolerant phenotype, which have been reported due to recent achievements in genomics.

Bacillus↗
PubMed2004

Uncoupling effect of fatty acids in halo- and alkalotolerant bacterium Bacillus pseudofirmus FTU.

Natural uncouplers of oxidative phosphorylation, long-chain non-esterified fatty acids, cause uncoupling in the alkalo- and halotolerant bacterium Bacillus pseudofirmus FTU. The uncoupling effect in the bacterial cells was manifested as decrease of membrane potential and increase of respiratory activity. The membrane potential decrease was detected only in bacterial cells exhausted by their endogenous substrates. In proteoliposomes containing reconstituted bacterial cytochrome c oxidase, fatty acids caused a "mild" uncoupling effect by reducing membrane potential only at low rate of membrane potential generation. "Free respiration" induced by the "mild" uncouplers, the fatty acids, can be considered as possible mechanism responsible for adaptation of the bacteria to a constantly changed environment.

Bacillus↗
PubMed2004

[Relationship between incisor position and status of facial soft tissues].

Thirty patients with sagittal, vertical, and transverse abnormalities of occlusion combined with abnormal position of the frontal teeth and improper shape and size of dentition were examined. The position of maxillary canines was evaluated by the method suggested by L. Garner (1974) determining the relationship between the location of frontal teeth and position of soft facial tissues.

Facial Asymmetry↗
PubMed2003

Ion transport coupled to terminal oxidase functioning in the extremely alkaliphilic halotolerant bacterium Thioalkalivibrio.

Proton transport in the terminal part of the respiratory chain in the extremely alkaliphilic halotolerant bacterial strain Thioalkalivibrio versutus was studied under near-optimum growth conditions (pH 9.0-9.5). Under these conditions, bacterial cells generated electric potential with the negative charge being inside the cells. When only the terminal part of the respiratory chain functioned, it was found that: 1) unlike other bacteria known, this bacterium did not acidify the medium in the presence of K(+) and valinomycin; 2) in the presence of an uncoupler, CCCP, but in the absence of valinomycin, reversible alkalinization of the medium occurred as a result of proton influx into the cells. Cyanide prevented this alkalinization. The difference spectra indicate that cell membranes contained cytochromes c and (b+o), some of which reacted with CO. The respiratory activity of membranes in the terminal part of the respiratory chain was optimal at pH 9.5 and specifically depended on sodium ions (C(1/2) = 10 mM). The data suggest the presence of a Na(+)-pump in the terminal part of the respiratory chain of the studied strain which can pump Na(+) out of the cells.

Alkalies↗
PubMed2003

[Sjogren's syndrome in chronic hepatitis C: clinical features and diagnosis].

AIM: To examine clinical features of Sjogren's syndrome (SS) and morphological picture of the lesser salivary glands (LSG) in chronic hepatitis C (CHC). MATERIAL AND METHODS: The examination of 42 patients with SS and chronic HCV infection (mean age 44.3 +/- 13.7 years) has detected signs of chronic hepatitis and hepatic cirrhosis, respectively, in 31 (71.4%) and 11 (26.2%) patients. "Dry syndrome" was diagnosed by criteria of European SS Study Group. LSG biopsy of the lower lip was conducted in 23 (54.7%) of 42 patients. RESULTS: The "dry" syndrome in CHC ran subclinically in 73.8% patients. Apparent symptoms of SS were seen primarily in middle-aged and aged women with CHC history over 10 years. The first signs of SS occurred in 25 (59.5%) patients 2.9 +/- 3.1 years prior to diagnosis of hepatic disease. All the patients had xerostomy. Xerophthalmia was recorded 1.5 times less frequently. In 16 (47.1%) patients with CHC "dry eye" and in 6 (17.6%) patients dry keratoconjunctivitis were detected. Pathohistological changes of LSG were diagnosed in 21 (91.3%) of 23 patients with CHC. In the majority of cases (86.9%) the glands exhibited insignificant inflammatory infiltration and advanced fibrosis. LSG in CHC is characterized by fibrosis prevalence over cell infiltration. 83.3% CHC patients had SS and other extrahepatic lesions. SS was most evident in 28.6% CHC patients with cryoglobulinemia. CONCLUSION: Registration of SS symptoms in CHC patients depends on targeted examination of patients with chronic HCV infection. The severity of the symptoms correlates directly with the infection duration and age of the patient. LSG lesions in CHC patients with SS are characterized by fibrosis pre-domination over cell infiltration.

Adult↗
PubMed2003

[Efficacy of lamivudine in HBeAg-negative chronic hepatitis B].

The necessity of the search for new drugs to treat chronic hepatitis B (CHB) is explained by the necessity to prevent hepatic cirrhosis (HC) and hepatocellular carcinoma. Treatment of HBeAg-negative CHB rests on the same principles as of HBeAg-positive one. Efficacy of nucleoside analogue lamivudin is well studied in HBeAg-positive CHB. The aim of this study was to evaluate lamivudine efficacy in therapy of HBeAg-negative CHB. Lamivudine (epivir--150 mg/day or zeffix--100 mg/day) was given for 1 year to 10 patients (5 males, 5 females, mean age 49.5 +/- 13.5). Their blood serum contained no HBeAg but contained HBeAb and HBVDNA. Chronic hepatitis was verified morphologically in 9 patients of whom 2 had HC and 2 developing HC. Moderate activity of the disease was in 4 patients, low--in 5. All the patients had a high ALT level (150 +/- 140 U/l, 60-528 U/l, high normal value 40 U/l). ALT and HBV DNA in the serum were examined by polymerase chain reaction in the course of treatment and for 6 months after its end. To the end of the treatment a complete response (absence of HBVDNA and normalization of ALT) was achieved in 8 (80%) patients. 5 (63%) of them 2-4 months after the end of the treatment had the exacerbation with appearance of HBVDNA in the serum and elevation of ALT level. A persistent response (6 months after lamivudin treatment) was in 3 (30%) patients, in 2 of them HBsAg was not detected. Lamivudin therapy is effective in HBeAg-negative CHB. In this study a high baseline level of ALT was the factor predisposing to a lasting response to treatment.

Adolescent↗
PubMed2003

[A new method for measuring dentition segments and the diagnosis of their occlusion].

A new method for evaluation of dentition during occlusion is suggested (2001). Thirty patients with normal occlusion were examined. Dental occlusion was evaluated for the frontal and lateral segments. Frontal and lateral (right and left) segments of the upper and lower teeth were examined, The upper and lower segments differed in size: the mean size of the upper frontal segment was 37.7 +/- 1.7 mm, that of the lower frontal segment 36.2 +/- 1.7 mm. The proportionality index was 1.04. The lateral segments of the upper and lower teeth were equal, their mean size being 20.2 +/- 0.8 mm. Hence, measurements of dentition segments during occlusion help evaluate their proportionality and detect changes in their sizes in patients with maxillodental abnormalities.

Anthropometry↗
PubMed2003

[The rate of HCV-RNA detection in the serum, saliva, and tissue of the minor salivary glands in chronic hepatitis C with Sjogren's syndrome].

The trial enrolled 38 patients with chronic HCV-infection and Sjogren's syndrome (mean age 44.3 +/- 13.7 years). Biopsy of the minor salivary glands (MSG) was made in 20 patients. Polymerase chain reaction was used to study 20 MSG biopsies, 38 samples of native saliva for HCV-RNA. Saliva samples were also studied for Herpes virus DNA (EBV, CMV, HHV-VI type). All the patients with VHC appeared to have signs of xerostomia, 24 (63.2%) patients had xerophthalmia. MSG pathohistological changes were found in 19 (95%) patients. In the majority of cases (86.9%) they were characterized by mild infiltration and advanced fibrosis. HCV-RNA was found in the saliva of 23 (57.5%) patients, in MSG tissue--in 9 (39.1%) patients. HCV-RNA detection in the saliva did not depend on the degree of viremia, viral RNA in MSG correlated with viral load. EBV and HHV-VI, HHV-VI only and EBV were detected only in 7 (18.4%), 10 (26.3%) and 6 (15.8%) patients, respectively. Xerostomia occurred with the same rate (26.1 and 31.3%) in patients with and without herpes viruses in the saliva. Detection rate for HCV-RNA in the saliva was not related with viremia degree. Sjogren's disease symptoms in CHC patients did not depend on the presence or absence of DNA of herpes viruses in the saliva.

Adult↗
PubMed2002

[Assessment of survival and risk of hepatocellular carcinoma in patients with cirrhosis of mixed (viral, alcoholic) etiology].

AIM: To determine factors affecting overall survival and risk to develop hepatocellular carcinoma (HCC) in patients with hepatic cirrhosis (HC) of mixed (viral, alcoholic) etiology. MATERIAL AND METHODS: Mono- and multi-variance analysis of prognostic effects of such factors as age of the patients, mixed infection VHB/VHC, markers of HBV replication, antibodies to nuclear antigen of HBV (HBcAb) without HBs-system in the serum ("isolated" HBcAb), duration of viral infection, alcohol intake and abuse, dilatation of the esophageal veins, some laboratory parameters were studied in 55 HC patients having at least one marker of hepatitis B virus (HBV) and/or hepatitis C virus (HCV), long history of alcohol abuse. RESULTS: It was found that risk of HCC was associated with duration of alcohol abuse and infection, mixed HBV/HCV infection, age 60 and older. Of independent significance was only duration of alcohol abuse. Lethal outcomes in HC patients in the mixed infection were due to development of HCC (36%) and HC complications (64%). Survival of the patients was less in severe dilatation of the esophageal veins, high clinicolaboratory index, low level of serum albumin, presence of "isolated" BcAb and mixed viral infection. CONCLUSION: Of the greatest prognostic efficacy in respect of survival was the model combining "isolated" HBcAb, the degree of esophageal veins dilatation and hepatitis activity.

Alcoholism↗
PubMed1998

[Extrahepatic manifestations of chronic hepatitis C].

AIM: To study incidence, special features and mechanisms underlying onset of extrahepatic lesions in HCV-infection. MATERIALS AND METHODS: Extrahepatic symptoms of chronic hepatitis C and its outcome--hepatic cirrhosis were studied in 157 patients. HCV-infection was confirmed by ELISA II and polymerase chain reaction (detection in the serum of anti-HCV and HCVRNA, respectively). Morphological studies of the liver were made in 134 patients, of other organs and tissues--in 20 patients. Immunological tests were made in 124 patients. Thyroid hormones, antibodies to thyroglobuline were measured with radioimmunoassay in 74 patients. RESULTS: Extrahepatic manifestations were found in 70(44.6%) patients with chronic hepatitis C (more frequently in hepatic cirrhosis), for the most part in women and in long-lasting disease. 54(43.5%) women had cryoglobulinemia, 27 of them showed it clinically. Patients with cryoglobulinemia and free of it exhibited varying frequency cutaneous vasculitis, Raynaud's syndrome, affection of the muscles and joints, nodular periartheritis, lesions of the lungs, myocarditis, autoimmune thyroiditis, Sjogren's syndrome, lichen ruber planus, porphyria cutanea tarda, immune cytopenia, autoimmune hemolytic anemia, hypoplastic anemia, monoclonal immunoglobulinopathy, B-cell lymphoma. Of high frequency were activity of rheumatic factor (66.9%), hypocomplementemia (31.8%), antinuclear antibodies (9.8%) and other immunological disorders. CONCLUSION: Some extrahepatic lesions in HCV-infection are detailed: frequent mixed cryoglobulinemia and associated vasculitides of different sites, malignant lymphoproliferative diseases, more frequent than in HBV-infection involvement of the thyroid and salivary glands, some skin lesions.

Adolescent↗
PubMed1997

[A method for assessing the morphological status of the maxillodental system].

The authors propose a device for measuring plaster models of patients' jaws with normal occlusion in order to evaluate the distance from the coordinate point to the point between the incisors (i), points of contact of the canines (p) and of contact of the first molars of the maxilla and mandible (m). It is possible to assess the position of the upper and lower dentition in the skull space in relation to the universal parameter--the coordinate point common for both dentitions and parameters of the skull.

Adolescent↗
PubMed1995

[Visceral manifestations of Wilson-Konovalov disease (analysis of 22 cases)].

Twenty-two patients with Wilson-Konovalov disease (WKD) had not only hepatic but also visceral symptoms: renal affection, cutaneous vasculitis, arthralgias, endocrine disorders, etc. In 8 of these 22 patients extrahepatic symptoms appeared 10 years before hepatic signs. The latter were distinguished by the frequency of edematic-ascitic syndrome, hemolytic episodes, hemorrhagic syndrome; low activity of serum aminotransferase. Initial neurological symptoms were registered in 6 patients only. 12 patients benefited from copper-eliminating therapy. 4 patients had advanced process which caused death. To detect WKD early, special diagnostic tests should be conducted in all subjects under 45 with hepatic symptoms or WKD-specific visceral manifestations. Examination of the patients' sibs is also desirable.

Adolescent↗
PubMed1992

[Liver cirrhosis and lymphoproliferative diseases].

Seven patients suffering from liver cirrhosis combined with lymphoproliferative diseases: chronic lymphoid leukemia (n = 4), lymphosarcoma (n = 3) were placed under observation. Viral etiology of liver cirrhosis was established in 4 patients (HBV markers were revealed in the serum in 2 and in liver tissue in 1) and was assumed in 3 patients (the lack in the anamnesis of other hepatotropic factors; multilobular form of liver cirrhosis). In 5 patients, the lymphoproliferative disease was diagnosed 2-30 years after the appearance of the symptoms of chronic diffuse liver disease. In 2 patients liver cirrhosis and hemoblastosis showed up simultaneously. The role of hepatitis viruses, HBV in particular, in the onset of lymphoproliferative diseases is under discussion.

Adult↗
PubMed1991

[Cortical-cell thymomas with predominance of so-called nurse-cells in patients with myasthenia].

30 thymomas in patients with generalized myasthenia studied histologically and immunohistochemically are classified as cortico-cell thymomas (n-15), medullary-cell (n-1), mixed-cell (n-10) and cortical-cell thymomas consisting mainly of thymic "nurse"-cells. Pronounced histological features of thymomas with the predominance of "nurse"-cells allow one to consider them as a special variant of thymic tumours. Production of thymic hormones by tumour cells in combination with the loss of HLA-DR antigen expression may be of importance in the pathogenesis of autoimmunization in patients with myasthenia.

Cell Count↗
PubMed1991

[Lung carcinosarcoma].

Lung carcinoma in a 72-year-old man smoker is described. Tumour, 12x8x8 sm in size, was located in the middle lobe of the right lung. Metastases were in the regional lymph nodes, soft tissue of the anterior abdominal wall, gastric mucosa and left adrenal. Epithelial component had signs of the undifferentiated carcinoma and adenocarcinoma, mesenchymal component consisted of leiomyosarcoma. Electron-microscopically, tumour cells with squamous, glandular, smooth muscle and fibroblastic features were found.

Aged↗