Regulation of L-carnitine metabolism in Escherichia coli

The metabolization of L-carnitine was studied using whole cells of Escherichia coli 044 K74. It showed features of an epigenetical control. L-carnitine and crotonobetaine were able to induce the carnitine-reducing system. Oxygen and nitrate as electron acceptors, gamma-butyrobetaine as final product of carnitine transformation in E. coli as well as glucose repress the carnitine metabolization. Other betaines and structurally related compounds did not show any effect neither as inductors nor as repressors.     

Effects of L-carnitine on neutrophil functions in aged rats

Several age-related alterations occur at the cellular level in the immune system leading to a decrease in the immune response. The present study was designed to determine the effect of L-carnitine on impaired neutrophil functions of aged rats. For this reason, superoxide anion radical production, chemotaxis and phagocytic activity were studied in the neutrophils obtained from the peripheral blood of young and old rats. We orally gavaged L-carnitine (50 mg/kg b.w. per day) or control vehicle into young (2 months) and aged (24 months) rats for 30 consecutive days. The neutrophils of aged rats exhibited an increase in superoxide anion production and decline in phagocytosis and chemotaxis when compared with that in young rat neutrophils. Superoxide anion production in aged rats was significantly decreased by L-carnitine treatment which was accompanied with a significant enhancement of chemotactic and phagocytic activity being restored to control levels. These findings demonstrated that L-carnitine is capable of restoring the age-related changes of neutrophil functions.     

Selenium: physiologic role and value in human pathology

Selenium (Se) is a metalloid with chemical properties closed to those of sulfur, but they can not substitute for one another in vivo. Se body content reflected soil Se content (13 to 20 mg in North Americans, 3 to 6 in New Zealand residents). The daily intake recommended is 50 to 200 micrograms. In the diet Se occurs in mineral or organic forms, the bioavailability of these latter is better. Se as selenocysteine is incorporated in specific proteins such as glutathione peroxidase (GSH-Px). Se is metabolized in H2Se by reductive pathways. H2Se is methylated and methylated compounds are excreted in the urines. The Se urinary excretion represents the principal known process of Se regulation. Se bound to GSH-Px participates to free radical destruction and cellular membrane protection. Its role is complementary of vitamin E effect. Se also seems indispensable to appropriate immune response. It can chelate various metals allowing their detoxication. Se metabolism can be studied by Se assay in serum, whole blood, urine (reference values must be performed for each studied population) and by GSH-Px activity determination in erythrocytes or platelets. Vitamin E assay completes estimation of the antioxidative status of organism. Few Se intoxications have been recognized but Se deficiencies often happen. They can lead to a cardiomyopathy (Keshan disease), increase the risk of cardiovascular diseases or cancer. Se deficiencies are found in chronic renal failure, malnutrition malabsorption, long term parenteral nutrition. At the present time it is not known how Se deficiency interfers with chronic infections which often go with these diseases. A better knowledge of Se requirements and Se role could allow an appropriate supplementation in various diseases.     

Gastric mucus glycoproteins : structure, functions and pathology (author's transl)]

O-glycosylated glycoproteins are the main constituents of gastric mucus. They are responsible for its viscosity and for its gel-forming properties. Recent advances accomplished over the last years on its physical and chemical characterization are briefly reviewed. Many issues remain still unsettled concerning the modification of its structure and composition in diseases as well as details of its biosynthesis and its pharmacology.     

Plasma membrane receptors of tissue macrophages: functions and role in pathology

The cells of the mononuclear phagocyte system (MPS) constitute a dispersed organ, which is distributed throughout the body. Macrophages in different tissues display distinctive mosaic phenotypes as resident and recruited cells of embryonic and bone marrow origin, respectively. They help to maintain homeostasis during development and throughout adult life, yet contribute to the pathogenesis of many disease processes, including inflammation, innate and adaptive immunity, metabolic disorders, and cancer. Heterogeneous tissue macrophage populations display a wide variety of surface molecules to recognise and respond to host, microbial, and exogenous ligands in their environment; their receptors mediate the uptake and destruction of effete and dying host cells and pathogens, as well as contribute trophic and secretory functions within every organ in the body. Apart from local cellular interactions, macrophage surface molecules and products serve to mobilise and coordinate systemic humoral and cellular responses. Their use as antigen markers in pathogenesis and as potential drug targets has lagged in clinical pathology and human immunotherapy. In this review, we summarise the properties of selected surface molecules expressed on macrophages in different tissues and disease processes, to provide a functional basis for diagnosis, further research, and treatment. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Thymus hyperplasia: classification, problems of patho- and morphogenesis, importance in human pathology]

Thymus hyperplasia may be congenital (thymomegaly) and acquired (acquired thymomegaly, "tumour-like" hyperplasia, lymphofollicular hyperplasia). Congenital thymomegaly is represented by variants with hypo- and hyperfunction of an adequately formed thymus and results from the congenital neuro-endocrine disturbances. Thymomegaly with a thymus hypofunction is a marker of the immunodeficiency. Acquired thymomegaly is also represented by two variants with hypo- and hyper-function of the thymus and is in fact a "phenocopy" of the congenital one. "Tumor-like" thymus hyperplasia is a rare form of its pathology with a thymic weight reaching 800 g thus resulting in a syndrome of the mediastinum organs compression. Lymphofollicular thymus hyperplasia can not be always considered to be a thymus pathology but it is characteristic of autoimmune and infectious-allergic diseases with lymphoid follicles localizing in the hyperplastic intralobular perivascular spaces. Thymus parenchyma changes depend on the main disease and play a main role in the development of thymus dysfunction, for example, in the autoimmune diseases. Formation of lymphoid follicles in the dilated perivascular spaces is a non-specific process.     

Victoria blue: staining properties in orthology and pathology]

The staining properties of the cationic dye Victoria Blue are summarized in consideration of the findings in the literature and own findings. Dependent on the staining conditions (with or without preoxidation of tissue sections), different structures and substances are stained by Victoria Blue. Without preoxidation elastic fibres, acid glycosaminoglycanes and DNA predominantly stained, but with preoxidation the dye stained insulin, some peptide hormones and secretion products, HBs-antigen, and lipofuscin. The chemism of the histochemical reaction is not quite understood yet.     

Chromium: physiologic role and implications in human pathology]

Reported values for total body stores of chromium vary between 0.4 mg and 6 mg. Chromium stores may be higher in neonates than in adults, relative to body size, whereas tissular chromium may be depleted in the elderly. The recommended daily allowance for chromium is 50 to 200 micrograms/day but actual needs are poorly known. Digestive absorption is better for organic chromium, which is part of the "glucose tolerance factor" (GTF), than for inorganic chromium. Furthermore, chromium (VI) is better absorbed than chromium (III). In the body, chromium (VI) is rapidly reduced to chromium (III) by a number of metabolic pathways. Absorbed chromium binds to proteins, mainly to transferrin which exhibits a high affinity for chromium (III). Most absorbed chromium is eliminated through the kidneys. Renal excretion occurs according to a two or more-compartment model. Current methods used to assay chromium, i.e., atomic absorption spectrometry using a graphite furnace or neutron activation, are sufficiently sensitive and specific to evaluate chromium levels in blood, urine or hair. However, none of these levels accurately reflects chromium body stores. Chromium is part of the GTF molecule. This factor has no effect per se but may facilitate binding of insulin to insulin receptors and amplify the effects of insulin on carbohydrate and lipid metabolism. Chromium deficiency may play a role in a development of some forms of adult diabetes mellitus and of arteriosclerosis. Partial chromium deficiencies seem to be common, especially in individuals with high intakes of refined foods. Acute chromium poisoning is usually due to an excess of chromium (VI) and is sometimes seen in the chromium industry.(ABSTRACT TRUNCATED AT 250 WORDS)     

HB-antigenemia and liver pathology]

The review deals with liver pathology in asymptomatic carriers of hepatitis B antigen. Information on the pattern and frequency of liver affection in carriers of HB antigen, on morphological methods for the detection of HB antigen in the liver tissue, on the frequency of the antigen detection in the liver tissue in asymptomatic antigen carriers and in liver diseases with HB antigenemia is presented. The data concerning the clinical and prognostic importance of hepatitis B antigen detection are given.     

Gomori reactions in orthology and pathology]

The following four basic histochemical reactions were developed by Gomori (1904-1957): 1. Silver impregnation of reticular fibres (1937); 2. Metal salt principle for detection of hydrolytic enzyme activity (1939); 3. Silver-methenamine reaction (1946); 4. Aldehyde fuchsin reaction (1950). These reactions and their modifications have assumed growing importance to expansion of knowledge, primarily on orthological and pathobiological problems.     

Teaching pathology in European countries]

Similarities and differences of pathology teaching in various European universities are described concerning mainly the number of academic hours assigned to different sections of pathology. General problems in the organization of higher, including medical, education are discussed. Rules and statuses of the European universities are considered in the light of the forthcoming reforms in Russian universities.     

Intracranial distension in neurosurgical pathology]

In contrast to the classic research into the problem of intracranial pressure based on the assumption that pressure in the cranial cavity is distributed uniformly, the initial methodological principle of the present work rests on the concept of the nonuniform distribution of pressure in the intracranial system both in health and disease. Comparative dynamic measurements of cerebrospinal fluid and brain tissue pressures were carried out in the early postoperative period to reveal absolute magnitudes of pressures and their correlations. Under examination were 166 neurosurgical patients with different levels of brain injury. The magnitude of cerebrospinal fluid pressure was demonstrated to depend on the level of brain injury. In the groups examined, intracerebral pressure of interstitial fluid in "normal" brain tissue was approximately the same (from -3 to +2 mm Hg). In brain edema, that pressure increased, sometimes to a considerable measure (up to 50 mm Hg). Neurosurgical pathology was shown to be characterized by nonuniform distribution of pressure in the main intracranial media: brain tissue and cerebrospinal fluid, which disturbs the physiological ratio of these pressures. It should be mentioned that some of the structures are under normal pressure whereas the other ones under elevated or lowered as compared to the physiological norm. Such a state can be correctly characterized by the term "intracranial distension" bearing in mind nonuniformity of tension in the intracranial system, a possible one-staged coexistence in the crane of the areas with elevated, normal and lowered pressures.