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Biomedical subjects

A A Ivanov

Publications and source records attributed to A A Ivanov.

At least 19 recordsLinked to original sources
PubMed1996

Therapeutic use of an antibiotic-resistant Bifidobacterium preparation in men exposed to high-dose gamma-irradiation.

Five men received high-dose, uneven, whole-body gamma-irradiation by accidental exposure to an unshielded 137Cs source. Analysis of the faeces 9-12 days post-irradiation showed low numbers of anaerobes and high counts of enterobacteria and staphylococci in four of the patients and total viable counts of < 10(3)/g in one. All five were treated with systemic ampicillin and gentamicin and oral nystatin commencing 4-7 days after irradiation. Three of the patients were also treated orally with a suspension of an antibiotic-resistant strain of Bifidobacterium longum for 30 days commencing 10-12 days post-irradiation. At 3 weeks post-irradiation, B. longum had appeared in their faecal flora and total anaerobe counts exceeded those of facultative and obligate aerobes. At 4 weeks and 5-7 weeks post-irradiation, this normalisation of the faecal flora continued. In contrast, in the two patients who received a placebo the faecal flora was dominated by enterobacteria (Klebsiella, Enterobacter and Serratia spp.) showing multiple antibiotic resistance 3 weeks post-irradiation. These potential opportunist pathogens were not isolated from the B. longum-treated group. Only one patient in the control group survived beyond 3 weeks; he continued to show high faecal counts of enterobacteria and staphylococci and low counts of obligate anaerobes. 'Probiotic' treatment with this antibiotic-resistant strain of B. longum may be of benefit in the treatment of radiation sickness, aiding normalisation of the faecal flora and inhibiting colonisation and overgrowth with opportunist pathogens.

Adult↗
PubMed1995

Passage of peptides through the blood-brain barrier with colloidal polymer particles (nanoparticles).

Transport of the hexapeptide dalargin across the blood-brain barrier was accomplished using a nanoparticle formulation. The formulation consisted of dalargin bound to poly(butyl cyanoacrylate) nanoparticles by sorption, coated with polysorbate 80. Intravenous injection of this formulation to mice resulted in an analgesic effect. All controls, including a simple mixture of the three components (drugs, nanoparticles, and surfactant) mixed directly before i.v. injection, exhibited no effect. Analgesia was also prevented by pretreatment with naloxone. Fluorescent and electron microscopic studies indicated that the passage of the particle-bound drug occurred by phagocytic uptake of the polysorbate 80-coated nanoparticles by the brain blood vessel endothelial cells.

Animals↗
PubMed1995

[Effects of a number of cytokines on the proliferation of mesangial cells and the production of extracellular matrix in anti-GBM nephritis].

The interaction of IL-1 and TNF alpha in the autolous phase of anti-GBM nephritis was studied. The influx of mononuclear leukocytes into the glomerulus and high cytokine levels induced a decrease in mesangial cell proliferation and an increase in extracellular matrix production. The methylprednisolone suppression of mononuclear leukocyte infiltration caused the autocine cytokine secretion of mesangial cells. Cyclophosphamide decreased cytokine production, but did not affect mononuclear leukocyte infiltration. The absence of mononuclear leukocytes in the site of the injury induced by imbalance between the synthesis and degradation of extracellular matrix components. The uncontrolled metabolism of the extracellular matrix may be induced glomerulosclerosis.

Animals↗
PubMed1995

[Which equipment for proton therapy of the future?].

The success of proton therapy depends on its cost. Hospital based equipment in fabrication for the Massachusetts General Hospital in Boston costs in the excess of 17 millions dollars, the accelerator being only a fraction of the cost. We think that price can be significantly decreased. We review the different new ways of accelerating protons currently under study in France in order to build a smaller, less expensive but reliable treatment device.

Cyclotrons↗
PubMed1994

[The skin autologous microflora index as a test for predicting acute morbidity in mass medical examinations of workers].

Basing on assessment of skin microflora in 3186 apparently health able-bodied individuals and on subsequent study of acute morbidity, the authors revealed direct dependence between these parameters: only 3.4% of people with normal level of microflora became ill during 1 month after the examination, the value of those with higher level was 15.5%. Therefore the skin microflora test could serve for prognosis.

Acute Disease↗
PubMed1994

[Vitamin and mineral enrichment of wheat flour of the high and first class quality].

Norms of inclusion of vitamins (B1; B2; PP) and mineral substances (Ca and Fe) in high and first-rate wheat's flour were defined. Vitamin's contents were verified and composed balance of vitamins and mineral substances contents in different stages of technology process. It was established efficacy of enrichment of wheat's flour with vitamin-mineral mixture to production as fast as possible, particularly in regions of Chernobil's accident and also in regions with ferrum deficiency.

Calcium↗
PubMed1994

[Hyperlipidemia and glomerulosclerosis in nephropathies: clinicomorphological comparisons].

An extracellular matrix (collagens I, III, IV) was studied in the glomeruli of patients demonstrating glomerular low density lipoproteins (LDL) and free of them. These two patients' groups were not found significantly different by age, nephropathy duration, blood pressure, serum concentrations of creatinine, triglycerides, HDL cholesterol. The LDL deposit group differed by longer duration of the nephrotic syndrome, higher 24-h proteinuria, lower serum albumin levels, higher total cholesterol in the serum and the proportion VLDL and LDL cholesterol to HDL cholesterol. They had noninflammatory nephropathies more frequently, collagen IV accumulated in the glomerulus more actively, there appeared interstitial collagens I and III. The discussion concerns the role of hypercholesterolemia with the above proportion of cholesterols, its duration, a type of cells dictating mesangial proliferation, in the development of LDL-deposit-induced glomerulosclerosis.

Adolescent↗
PubMed1993

[The possible approaches to the theoretical validation of the use of cytostatics and corticosteroids in treating glomerulonephritis].

Cyclophosphamide (CP) and methylprednisolone (MP) were tried on rats with experimental nephrotoxic serum nephritis and mice with experimental acute serum nephritis. Pathological processes were analyzed simultaneously in vivo and in vitro. CP reduced the antibody impairment and stimulated glomerular infiltration by mononuclear leukocytes whose mediator spectrum was oriented to repair. MP failed to stop the impairment and aggravated the infiltration. The resultant chaotic accumulation of the extracellular matrix raised the risk of sclerosis. CP showed the advantages in experiment demonstrable also in the clinical setting.

Adrenal Cortex Hormones↗
PubMed1992

[Immunohistochemical characteristics of serum nephrotoxic nephritis in rats: effect of methylprednisolone and potassium fenozan].

Late heterologous and autologous stages of nephrotoxic serum nephritis were studied against the background of MP-induced immunological suppression and PP effect on arachidonic acid metabolism. MP prevented mononuclear infiltration of the renal glomerulus and the development of severe morphological lesions in the autologous stage, while cell culture and mononuclear leukocyte number drastically decreased. PP did not significantly influence the autologous stage of the nephritis though resulted in marked proliferation in both renal glomerulus and mesangial cell culture during the heterologous stage. In spite of more pronounced proliferative activity of mesangial cells interleukin-I level was lower than in animals with nephritis untreated with PP. The enhancement of the proliferative reaction is obviously related, apart from interleukin-I, to the effect of other growth factors.

Animals↗
PubMed1991

[Immunohistochemical features of nephrotoxic serum nephritis in the rat: the role of interleukin-1 in the development of heterologous and autologous stages].

Late heterologous and autologous stages of serum nephritis together with glomerular cells in culture are studied biochemically, morphologically and immunohistochemically for the assessment of the role of mononuclear leucocyte mediator system. The heterologous stage of the nephrotoxic nephritis is associated with the increase of Interleukin-I and TxA2 production. Role of Interleukin-I in the autologous stage is less pronounced in spite of proliferative activity of cultured mesangial cells. The effect of suppressive factors prevails in the glomerulus.

Animals↗
PubMed1991

[Short- and long-term immune status in people after radiation injury as a result of the accident at the Chernobyl Nuclear Power Station].

Humoral and cellular factors of the immune system of 133 subjects injured in the Chernobyl accident were studied during first 1.5-2 months after radiation, 5-17 months and 3 years after they suffered acute radiation sickness (I-IV degree). Significant disorders in the immune system correlating with the severity of the disease were recorded. In late terms certain shifts persisted in the immune status of subjects who had suffered acute radiation sickness, II and III degree.

Accidents↗