Reference Gene Validation in the Embryonic and Postnatal Brain in the Rat Hyperhomocysteinemia Model

Maternal hyperhomocysteinemia (HCY) induced by genetic defects in methionine cycle enzymes or vitamin imbalance is known to be a pathologic factor that can impair embryonal brain development and cause long-term consequences in the postnatal brain development as well as changes in the expression of neuronal genes. Studies of the gene expression on this model requires the selection of optimal housekeeping genes. This work aimed to analyze the expression stability of housekeeping genes in offspring brain. Pregnant female Wistar rats were treated daily with a 0.15% L-methionine solution in the period starting on the 4th day of pregnancy until delivery, to cause the increase in the homocysteine level in fetus blood and brain. Housekeeping gene expression was assessed by RT-qPCR on whole embryonic brain and selected rat brain areas at P20 and P90. The amplification curves were analyzed, and raw means Cq data were imported to the RefFinder online tool to assess the reference genes stability. Most of the analyzed genes showed high stability of mRNA expression in the fetal brain at both periods of analysis (E14 and E20). However, the most stably expressed genes at different age points differed. Actb, Ppia, Rpl13a are the most stably expressed on E14, Ywhaz, Pgk1, Hprt1 - on E20 and P20, Hprt1, Actb, and Pgk1 - on P90. Gapdh gene used as a reference in various studies demonstrates high stability only in the hippocampus and cannot be recommended as the optimal reference gene on HCY model. Hprt1 and Pgk1 genes were found to be the most stably expressed in the brain of rat subjected to HCY. These two genes showed high stability in the brain on E20 and in various areas of the brain on the P20 and P90. On E14, the preferred genes for normalization are Actb, Ppia, Rpl13a.

Beneficial Effects of Probiotic Bifidobacterium longum in a Lithium-Pilocarpine Model of Temporal Lobe Epilepsy in Rats

Epilepsy is a challenging brain disorder that is often difficult to treat with conventional therapies. The gut microbiota has been shown to play an important role in the development of neuropsychiatric disorders, including epilepsy. In this study, the effects of Bifidobacterium longum, a probiotic, on inflammation, neuronal degeneration, and behavior are evaluated in a lithium-pilocarpine model of temporal lobe epilepsy (TLE) induced in young adult rats. B. longum was administered orally at a dose of 10⁹ CFU/rat for 30 days after pilocarpine injection. The results show that B. longum treatment has beneficial effects on the TLE-induced changes in anxiety levels, neuronal death in the amygdala, and body weight recovery. In addition, B. longum increased the expression of anti-inflammatory and neuroprotective genes, such as Il1rn and Pparg. However, the probiotic had little effect on TLE-induced astrogliosis and microgliosis and did not reduce neuronal death in the hippocampus and temporal cortex. The study suggests that B. longum may have a beneficial effect on TLE and may provide valuable insights into the role of gut bacteria in epileptogenesis. In addition, the results show that B. longum may be a promising drug for the comprehensive treatment of epilepsy.

Alterations in the Properties of the Rat Hippocampus Glutamatergic System in the Lithium-Pilocarpine Model of Temporal Lobe Epilepsy

Status epilepticus (SE) triggers many not yet fully understood pathological changes in the nervous system that can lead to the development of epilepsy. In this work, we studied the effects of SE on the properties of excitatory glutamatergic transmission in the hippocampus in the lithium-pilocarpine model of temporal lobe epilepsy in rats. The studies were performed 1 day (acute phase), 3 and 7 days (latent phase), and 30 to 80 days (chronic phase) after SE. According to RT-qPCR data, expression of the genes coding for the AMPA receptor subunits GluA1 and GluA2 was downregulated in the latent phase, which may lead to the increased proportion of calcium-permeable AMPA receptors that play an essential role in the pathogenesis of many CNS diseases. The efficiency of excitatory synaptic neurotransmission in acute brain slices was decreased in all phases of the model, as determined by recording field responses in the CA1 region of the hippocampus in response to the stimulation of Schaffer collaterals by electric current of different strengths. However, the frequency of spontaneous excitatory postsynaptic potentials increased in the chronic phase, indicating an increased background activity of the glutamatergic system in epilepsy. This was also evidenced by a decrease in the threshold current causing hindlimb extension in the maximal electroshock seizure threshold test in rats with temporal lobe epilepsy compared to the control animals. The results suggest a series of functional changes in the properties of glutamatergic system associated with the epilepsy development and can be used to develop the antiepileptogenic therapy.

Imbalance of Angiogenic and Growth Factors in Placenta in Maternal Hyperhomocysteinemia

Numerous studies have shown that various adverse factors of different nature and action mechanisms have similar negative influence on placental angiogenesis, resulting in insufficiency of placental blood supply. One of the risk factors for pregnancy complications with placental etiology is an increased level of homocysteine in the blood of pregnant women. However, the effect of hyperhomocysteinemia (HHcy) on the development of the placenta and, in particular, on the formation of its vascular network is at present poorly understood. The aim of this work was to study the effect of maternal HHcy on the expression of angiogenic and growth factors (VEGF-A, MMP-2, VEGF-B, BDNF, NGF), as well as their receptors (VEGFR-2, TrkB, p75NTR), in the rat placenta. The effects of HHcy were studied in the morphologically and functionally different maternal and fetal parts of the placenta on the 14th and 20th day of pregnancy. The maternal HHcy caused increase in the levels of oxidative stress and apoptosis markers accompanied by an imbalance of the studied angiogenic and growth factors in the maternal and/or fetal part of the placenta. The influence of maternal HHcy in most cases manifested in a decrease in the protein content (VEGF-A), enzymatic activity (MMP-2), gene expression (VEGFB, NGF, TRKB), and accumulation of precursor form (proBDNF) of the investigated factors. In some cases, the effects of HHcy differed depending on the placental part and stage of development. The influence of maternal HHcy on signaling pathways and processes controlled by the studied angiogenic and growth factors could lead to incomplete development of the placental vasculature and decrease in the placental transport, resulting in fetal growth restriction and impaired fetal brain development.

Changes in Metabotropic Glutamate Receptor Gene Expression in Rat Brain in a Lithium-Pilocarpine Model of Temporal Lobe Epilepsy

Preventing epileptogenesis in people at risk is an unmet medical need. Metabotropic glutamate receptors (mGluRs) are promising targets for such therapy. However, drugs acting on mGluRs are not used in the clinic due to limited knowledge of the involvement of mGluRs in epileptogenesis. This study aimed to analyze the changes in gene expression of mGluR subtypes (1-5, 7, 8) in various rat brain regions in the latent and chronic phases of a lithium-pilocarpine model of epilepsy. For this study, multiplex test systems were selected and optimized to analyze mGluR gene expression using RT-qPCR. Region- and phase-specific changes in expression were revealed. During the latent phase, mGluR5 mRNA levels were increased in the dorsal and ventral hippocampus, and expression of group III genes was decreased in the hippocampus and temporal cortex, which could contribute to epileptogenesis. Most of the changes in expression detected in the latent stage were absent in the chronic stage, but mGluR8 mRNA production remained reduced in the hippocampus. Moreover, we found that gene expression of group II mGluRs was altered only in the chronic phase. The study deepened our understanding of the mechanisms of epileptogenesis and suggested that agonists of group III mGluRs are the most promising targets for preventing epilepsy.

MTEP, a Selective mGluR5 Antagonist, Had a Neuroprotective Effect but Did Not Prevent the Development of Spontaneous Recurrent Seizures and Behavioral Comorbidities in the Rat Lithium-Pilocarpine Model of Epilepsy

Metabotropic glutamate receptors (mGluRs) are expressed predominantly on neurons and glial cells and are involved in the modulation of a wide range of signal transduction cascades. Therefore, different subtypes of mGluRs are considered a promising target for the treatment of various brain diseases. Previous studies have demonstrated the seizure-induced upregulation of mGluR5; however, its functional significance is still unclear. In the present study, we aimed to clarify the effect of treatment with the selective mGluR5 antagonist 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]-pyridine (MTEP) on epileptogenesis and behavioral impairments in rats using the lithium–pilocarpine model. We found that the administration of MTEP during the latent phase of the model did not improve survival, prevent the development of epilepsy, or attenuate its manifestations in rats. However, MTEP treatment completely prevented neuronal loss and partially attenuated astrogliosis in the hippocampus. An increase in excitatory amino acid transporter 2 expression, which has been detected in treated rats, may prevent excitotoxicity and be a potential mechanism of neuroprotection. We also found that MTEP administration did not prevent the behavioral comorbidities such as depressive-like behavior, motor hyperactivity, reduction of exploratory behavior, and cognitive impairments typical in the lithium–pilocarpine model. Thus, despite the distinct neuroprotective effect, the MTEP treatment was ineffective in preventing epilepsy.

The application of the self-probing primer PCR for quantitative expression analysis of R607Q (un)edited GluA2 AMPA receptor mRNA

Adenosine deaminase-dependent RNA editing is a widespread universal mechanism of posttranscriptional gene function modulation. Changes in RNA editing level may contribute to various physiological and pathological processes. In the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) glutamate receptor GluA2 subunit, A-I editing in the Q607R site leads to dramatic changes in function, making the receptor channel calcium-impermeable. A standard approach for quantifying (un)edited RNAs is based on endpoint PCR (Sanger sequencing or restriction analysis), a time-consuming and semiquantitative method. We aimed to develop RT-qPCR assays to quantify rat Q607R (A-I) edited/unedited mRNA in samples in the present work. Based on self-probing PCR detection chemistry, described initially for detecting short DNA fragments, we designed and optimised RT-qPCR assays to quantify Q607R (un)edited mRNA. We used self-probing primer PCR technology for mRNA quantification for the first time. Using a novel assay, we confirmed that Q607R GluA2 mRNA editing was increased in 14-day- (P14) or 21-day-old (P21) postnatal brain tissue (hippocampus) compared to the embryonic brain (whole brains at E20) in Wistar rats. Q607R unedited GluA2 mRNA was detectable by our assay in the cDNA of mature brain tissue compared to that derived through classical methods. Thus, self-probing primer PCR detection chemistry is an easy-to-use approach for RT-qPCR analysis of RNA editing.

Early Life Febrile Seizures Impair Hippocampal Synaptic Plasticity in Young Rats

Febrile seizures (FSs) in early life are significant risk factors of neurological disorders and cognitive impairment in later life. However, existing data about the impact of FSs on the developing brain are conflicting. We aimed to investigate morphological and functional changes in the hippocampus of young rats exposed to hyperthermia-induced seizures at postnatal day 10. We found that FSs led to a slight morphological disturbance. The cell numbers decreased by 10% in the CA1 and hilus but did not reduce in the CA3 or dentate gyrus areas. In contrast, functional impairments were robust. Long-term potentiation (LTP) in CA3-CA1 synapses was strongly reduced, which we attribute to the insufficient activity of N-methyl-D-aspartate receptors (NMDARs). Using whole-cell recordings, we found higher desensitization of NMDAR currents in the FS group. Since the desensitization of NMDARs depends on subunit composition, we analyzed NMDAR current decays and gene expression of subunits, which revealed no differences between control and FS rats. We suggest that an increased desensitization is due to insufficient activation of the glycine site of NMDARs, as the application of D-serine, the glycine site agonist, allows the restoration of LTP to a control value. Our results reveal a new molecular mechanism of FS impact on the developing brain.

Anakinra Reduces Epileptogenesis, Provides Neuroprotection, and Attenuates Behavioral Impairments in Rats in the Lithium-Pilocarpine Model of Epilepsy

Temporal lobe epilepsy is a widespread chronic disorder that manifests as spontaneous seizures and is often characterized by refractoriness to drug treatment. Temporal lobe epilepsy can be caused by a primary brain injury; therefore, the prevention of epileptogenesis after a primary event is considered one of the best treatment options. However, a preventive treatment for epilepsy still does not exist. Neuroinflammation is directly involved in epileptogenesis and neurodegeneration, leading to the epileptic condition and cognitive decline. In the present study, we aimed to clarify the effect of treatment with a recombinant form of the Interleukin-1 receptor antagonist (anakinra) on epileptogenesis and behavioral impairments in rats using the lithium–pilocarpine model. We found that anakinra administration during the latent phase of the model significantly suppressed the duration and frequency of spontaneous recurrent seizures in the chronic phase. Moreover, anakinra administration prevented some behavioral impairments, including motor hyperactivity and disturbances in social interactions, during both the latent and chronic periods. Histological analysis revealed that anakinra administration decreased neuronal loss in the CA1 and CA3 areas of the hippocampus but did not prevent astro- and microgliosis. The treatment increased the expression level of the solute carrier family 1 member 2 gene (Slc1a2, encoding excitatory amino acid transporter 2 (EAAT2)) in the hippocampus, potentially leading to a neuroprotective effect. However, the increased gene expression of proinflammatory cytokine genes (Interleukin-1β (Il1b) and tumor necrosis factor α (Tnfa)) and astroglial marker genes (glial fibrillary acidic protein (Gfap) and inositol 1,4,5-trisphosphate receptor type 2 (Itpr2)) in experimental rats was not affected by anakinra treatment. Thus, our data demonstrate that the administration of anakinra during epileptogenesis has some beneficial disease-modifying effects.

[The role of optimal nutrition in the prevention of cardiovascular diseases]

A balanced diet has always been part of a set of preventive measures with cardiovascular diseases (CVD). The aim of the research is to present relevant international data on the role of nutrients in reducing the risk of CVD. Results. This article discusses current data on the effect of consumption of saturated and unsaturated fatty acids, trans fats, cholesterol, dietary fiber, protein, edible salt potassium, magnesium and vitamins on the state of the cardiovascular system and the prevention of CVD. Recommendations on optimal nutrition are given to reduce cardiovascular risks, including those according to the new 3rd edition of the Guide to Cardiovascular Medicine (The ESC Textbook of Cardiovascular Medicine, 3 edn). Conclusion. When managing patients with cardiovascular diseases, it is necessary not only to take into account international nutritional recommendations, but also to focus the patient's attention on how to comply with them.

Reference Gene Validation in the Brain Regions of Young Rats after Pentylenetetrazole-Induced Seizures

Reverse transcription followed by quantitative polymerase chain reaction (qRT-PCR) is a powerful and commonly used tool for gene expression analysis. It requires the right choice of stably expressed reference genes for accurate normalization. In this work, we aimed to select the optimal reference genes for qRT-PCR normalization within different brain areas during the first week following pentylenetetrazole-induced seizures in immature (P20–22) Wistar rats. We have tested the expression stability of a panel of nine housekeeping genes: Actb, Gapdh, B2m, Rpl13a, Sdha, Ppia, Hprt1, Pgk1, and Ywhaz. Based on geometric averaging of ranks obtained by four common algorithms (geNorm, NormFinder, BestKeeper, Comparative Delta-Ct), we found that the stability of tested reference genes varied significantly between different brain regions. The expression of the tested panel of genes was very stable within the medial prefrontal and temporal cortex, and the dorsal hippocampus. However, within the ventral hippocampus, the entorhinal cortex and amygdala expression levels of most of the tested genes were not steady. The data revealed that in the pentylenetetrazole-induced seizure model in juvenile rats, Pgk1, Ppia, and B2m expression are the most stable within the medial prefrontal cortex; Ppia, Rpl13a, and Sdha within the temporal cortex; Pgk1, Ppia, and Rpl13a within the entorhinal cortex; Gapdh, Ppia, and Pgk1 within the dorsal hippocampus; Rpl13a, Sdha, and Ppia within the ventral hippocampus; and Sdha, Pgk1, and Ppia within the amygdala. Our data indicate the need for a differential selection of reference genes across brain regions, including the dorsal and ventral hippocampus.

[Deliberate medication poisoning in adolescence as a medical and socially significant problem]

One of the urgent medical and social problems of modern society is the steady growth of auto-aggressive behavior and deliberate medication poisoning among adolescents and young adults. This investigation was held to optimize the provision of specialized medical care for acute deliberate self-poisoning in teenagers. We examined 498 patients admitted to the Toxicology Department of N. F. Filatov Children City Clinical Hospital No. 13 with a diagnosis of acute deliberate medication poisoning. The diagnosis was confirmed by chemical and toxicological urine test using thin-layer chromatography. From 2016 to 2018 the number of patients with deliberate medication poisoning increased by more than 2.5 times and amounted to 236 cases. Female patients were prevalent and accounted for up to 85% of cases. The leading position among medication self-poisoning is held by psychopharmacological drugs at 56%, in second place are non-steroidal anti-inflammatory drugs at 18.5%. The main causes of self-poisoning were social or family conflicts (47%), problems at school (35%), and Internet-related complaints (18%). The clinical manifestations of the disease in the acute period of chemical poisoning depended on the toxic agent and the dose taken. Psychological testing revealed a high level of neuroticism in 71% of adolescents, severe anxiety was observed in 57% of patients, and depression was diagnosed in 28% of cases. All patients were provided specialized medical care, including resuscitation, detoxification, and psychiatrist examination. Based on the accumulated clinical experience, an algorithm for managing adolescents with deliberate medication poisoning has been developed, which has reduced the number of repeated suicides by 1.8 times.

[Experimental verification of thulium lithotripsy]

AIM

Experimental evaluation of the efficacy and safety of lithotripsy using a new pulsed thulium fiber laser operating at a wavelength of 1.94 microns, peak power of 500 watts (maximum average power of 50 watts) by comparing it with a holmium laser operating at a wavelength of 2.1 microns (average maximum power 100 W and 120 W).

RELEVANCE

The proportion of minimally invasive surgery in the management of urolithiasis, including retrograde intrarenal surgery, is steadily growing. The most appropriate tool for stone destruction is a laser. To date, the gold standard of minimally invasive surgical treatment of nephrolithiasis is holmium laser lithotripsy, which uses a laser on yttrium-aluminum-garnet activated by holmium ions (Ho: YAG) operating at a wavelength of 2.1 m. However, in recent years, lasers on a Tm-activated fiber with a wavelength of 1.94 m have become increasingly popular since the water absorption coefficient for the Tm radiation of a fiber laser is 5.5 times higher than for a Ho: YAG laser and in 2.2 times higher than for the Tm: YAG laser. This difference may translate into greater effectiveness and speed of stone crushing, which in turn leads to shorter operating time.

MATERIALS AND METHODS

This article describes physical foundations of holmium and thulium laser radiation, the mechanisms of stone fragmentation, data from a series of experiments comparing the efficiency and safety of ex-vivo lithotripsy using a holmium solid-state laser with a wavelength of 2.1 m and a thulium fiber laser with a wavelength of 1.94 m.

RESULTS

The study findings suggest that the STA IRE-Polyus thulium fiber laser operating at a wavelength of 1.94 microns and a maximum power of 500 watts has several advantages over the holmium laser in the stone fragmentation in urological practice.

CONCLUSION

The results of the experimental work allow us to conclude that the use of a thulium fiber laser operating at a wavelength of 1.94 m and a maximum peak power of 500 W enables highly effective and safe lithotripsy.

[Initial experience in clinical application of thulium laser contact lithotripsy for transurethral treatment of urolithiasis]

INTRODUCTION

The choice of an effective and safe method of disintegration of stones in upper and lower urinary tract is very important in the context of continuous scientific and technological progress. In current clinical urological practice, various lithotriptors with rigid and flexible probes are used for contact disintegration of stones, having both advantages and disadvantages. This study aimed to analyze the first results of the clinical application of the native Tm: fiber Urolaz laser (STA IRE-Polyus, Russia) for contact transurethral lithotripsy.

MATERIALS AND METHODS

The study comprised 56 patients who underwent transurethral contact thulium laser lithotripsy for 68 stones of the upper and lower urinary tracts between April and September 2017. Forty-four patients had kidney and ureteral stones, and twelve patients had urinary bladder stones. Twenty-four kidney stones were removed by retrograde intrarenal surgery using ureteral casing, flexible ureteropyeloscope and thulium laser, 32 stones in various ureteral segments - by rigid contact thulium laser ureterolithotripsy and 12 bladder stones - by thulium laser cystolithotripsy. The size of the upper urinary tract stones varied from 0.6 to 1.8 cm, bladder stones measured from 1.1 to 3.5 cm. Also, experimental studies were carried out to investigate the effects of the fiber thulium and holmium laser on the stone displacement and temperature environment during lithotripsy.

RESULTS

Full stone fragmentation was achieved in 100% of patients. 47.7% of patients required additional lithoextraction of fragments; there was no retrograde migration of large stones. The mean duration of stone disintegration was 19 minutes. Postoperatively, 15.9% of patients had an exacerbation of pyelonephritis, which was successfully managed by conservative measures. The mean postoperative hospital stay was 2.4+/-1.1 days. At follow-up examination 4-6 weeks after surgery, one patient was found to have a residual symptomatic ureteral stone, which required extracorporeal short-wave lithotripsy. The experimental study showed that fiber thulium laser lithotripsy produced much less propulsion of artificial stone than Holmium laser lithotripsy. With the use of therapeutic power, neither of the lasers resulted in "dangerous" rises of the washing fluid temperature during stone disintegration.

CONCLUSION

Using the universal thulium laser system "Urolaz" provides a significant improvement in the effectiveness of endourologic upper urinary tract interventions and significantly reduces the likelihood of intraoperative trauma and postoperative complications, which contributes to improving the quality of specialized urological care.

[The possibilities for the restoration of the laryngeal function: the current state-of-the-art]

The restoration of the functional competence of the larynx following bilateral laryngeal nerve damage and vocal fold paralysis is a serious challenge for the surgeon that has thus far no satisfactory solution. Physiological re-innervation that occurs naturally with time is non-selective and, in the majority of the cases, leads to synkinesis. Laryngeal pacing achieved with the application of the implantable microchips appears to be a promising approach. The animal experiments have demonstrated the possibility of successful restoration of all the functions of the larynx by means of laryngeal pacing but simultaneously revealed a number of technical issues that have to be addressed if the further progress in this field is to be achieved including the choice of the proper materials for implantation, solution of problems pertaining to the neuromuscular mapping during pacer implantation, etc.). The results of the first prospective clinical trial involving the human patients gave evidence suggesting that the laryngeal electrostimulation technology is both safe and efficient. Nevertheless, further investigations and modification of the method are needed before it can be recommended for the wider application in the routine clinical practice.

The truth is out there: the metal-π interactions in crystal of Cr(CO)3(pcp) as revealed by the study of vibrational smearing of electron density

The vibrational smearing of electron density was studied in the crystal of complex of Cr(CO)3 with [2.2]paracyclophane. The combination of theoretical and experimental methods, including periodic calculations and screening of DFT calculated and multipole-decomposed electron densities, was utilized to reveal the vibrational smearing of electron density and its influence on the multipole-constructed electron density. The multipole model, commonly used to treat the high-resolution X-ray diffraction data, was shown to be rather inaccurate in description of electron density and its vibrational smearing in metal-π complex where the interchange between diatomic interactions can occur. Namely, some bond critical points can be hidden while analyzing multipole-decomposed electron density with proved effects of vibrational smearing even if the deconvolution problem is overcome by using the invariom approach. On the contrary, the recently proposed “clouds of critical point variation” (CCPV) approach is demonstrated as the route to gather all reasonable bonding trends and to reconstruct static electron density pattern in metal-π complexes.

[Laser lithotripsy]

The article describes the diverse methods of stone destruction in urolithiasis patients, including laser lithotripsy as the least traumatic and most efficient method of demolition of all types of urinary stones. Different types of lasers for intracorporeal lithotripsy have different mechanisms of stone fragmentation depending on the type of laser and its radiation parameters. The latest researches showed that new and promising laser modalities for lithotripsy are devices based on thulium (Tm) doped fiber laser, which can not only increase by several times the speed of the of stone fragmentation, but also minimizes the risks of surgical complications, due to the peculiarities of interaction between radiation and biological tissues.

[Diagnosis and surgical treatment of adrenocortical cancer with invasion into great veins]

AIM

To estimate immediate and remote resaults of treatment of adrenocortical cancer with invasion into great veins.

MATERIAL AND METHODS

It was analyzed survey and treatment results in 3 patients with adrenocortical cancer and invasion into renal veins and inferior vena cava.

RESULTS

Radical surgery with tumoral thrombi removal from great vessels was performed in all cases. There were no complications and deaths in early postoperative period. Life expectancy after surgery was 6, 13 and over 58 months.

CONCLUSION

At present time surgical intervention for adrenocortical cancer with invasion into great veins is single method to prolong patients' life.

[A method of pylorus-preserving resection of the stomach for duodenum ulcer disease]

A method of pylorus-preserving resection of the stomach including dissection of the ulcer and segmental resection of the duodenum followed by a pylorus-preserving resection of the stomach was developed and used in the clinic in 8 patients with ulcer disease of the duodenum. Positive effect manifested itself as preserved functional activity of the pylorus complex and duodenum. The method allows securing adequate pathogenetic effects, leveling the development of such complications as chronic impairment of duodenal patency, duodenal-gastric reflux, dumping syndrome.

[The immunogenicity and heterogeneity of Pseudomonas pseudomallei surface antigen 8]

Surface antigen 8, one of pathogenicity factors of P.pseudomallei and having an antiphagocytic action, contains glycoprotein with a mol. wt. of 200 kD and proteins with mol wt. of 25, 30 and 34 kD. According to its chemical structure, the carbohydrate part of antigen 8 is the homogeneous polymer of 6-d-D-mannoheptose, and its protein component is a collection of monomer proteins with mol. wt. of 12-120 kD. The consecutive fractionation of antigen 8 by gel and ion exchange chromatography has made it possible to isolate its individual fragments, differing by the collection of antigenic components, as well as by their antiphagocytic and protective activity. Experiments have shown that glycoprotein with a mol. wt. of 200 kD is an active immunosuppressive agent, while protein with a mol. wt. of 34 kD produces a pronounced immunogenic effect.

[The early laboratory diagnosis of the pulmonary form of glanders and melioidosis by using rapid methods of immunochemical analysis]

The problems of the sanitary guarding of frontiers comprise such aspects as the early recognition of infectious diseases, even those which are considered exotic in the Russian Federation. These diseases include glanders and melioidosis, infections which are endemic for some frontier regions. The study performed on experimental models of the pulmonary form of glanders and melioidosis with the acute course of the diseases demonstrates that the use of such laboratory diagnostic methods as immunosorbent variants of the enzyme-linked, chemiluminescent and immunofluorescent immunoassays permits making reliable diagnosis as early as 3-12 hours after aspiration infection.

[The correction of the fluorine load in caries]

The authors discuss the problem of fluorine load correction in caries. They claim that fluorine load of the body as regards caries prevention should never surpass the safe levels of total daily fluorine consumption. In children aged over 4 the safe level of total daily fluorine consumption is 2.5 mg, in adults 4 mg.

[Dietary fiber content of diets of the Don Basin population]

It has been demonstrated that the total content of food fibers in the daily diet of the Donbas population diets amounts to 24.0-26.3 g (cellulose 5.9-6.7 g, pectin 2.0-2.7 g, hemicellulose 16.1-16.9 g). Baked goods account for the major part of hemicellulose (about 85%) and 1/3 of cellulose. Potato and vegetables (fruit) account for half of pectin and 1/3 of cellulose. The daily requirement of cellulose and pectin was satisfied by about 1/3, which is accounted for by a high relative significance of refined products (about 60% of the diet caloric value).