[Multiple system atrophy]

The article presents a progressive neurodegenerative disease - multisystem atrophy, characterized by a combination of autonomic failure and various motor disorders, including parkinsonism and/or cerebellar ataxia; etiopathogenetic factors and variants of the clinical picture are described. We describe own clinical observation of a 59-old patient with cerebellar and bulbar syndromes, parkinsonism, pyramidal insufficiency, cognitive deficits, and autonomic dysfunction. The differential diagnosis included a whole range of neurodegenerative and hereditary diseases: Parkinson's disease, vascular parkinsonism, progressive supranuclear palsy, spinocerebellar ataxia, FXTAS, mitochondrial encephalopathies. The moderate severity of parkinsonism and the significant predominance of cerebellar symptoms and autonomic dysfunction make this clinical case difficult to diagnose. However, based on the life and disease history, clinical picture and research methods, a diagnosis of multiple system atrophy, cerebellar type (cerebellar, autonomic, bulbar syndrome, parkinsonism, pyramidal insufficiency and moderate cognitive impairment) was established. Differential search in such patients is a difficult task and includes a whole range of neurodegenerative and hereditary diseases due to the similarity of individual clinical and neuroimaging features and, unfortunately, the limited availability of molecular genetic diagnostic methods. However, earlier diagnosis is necessary to focus in time on the development of a personalized approach to the management of each such patient, taking into account the rate of symptoms development and steady progression, in order to ensure the longest possible survival time with an acceptable level of quality of life.

[Difficulties of cerebral toxoplasmosis diagnosis in a patient with multiple sclerosis and HIV]

Toxoplasmosis is a widespread parasitic disease. It is caused by an intracellular parasite Toxoplasma gondii. It can affect various tissues and organs, forming cysts and continuing to replicate within them. In people with intact immune system, tissue cysts remain in latent state throughout their whole life. However, in cases of cellular immunodeficiency the infection can be reactivated, which leads to secondary generalization of the process. People with HIV most commonly present with cerebral toxoplasmosis. Non-specific neuroimaging signs, as well as absence of pathognomonic symptoms and specific laboratory data lead to difficulties of cerebral toxoplasmosis diagnosis, particularly in the cases with a history of multiple sclerosis that has similar clinical symptoms and brain MRI data suggesting of tumefactive multiple sclerosis image. A clinical case of cerebral toxoplasmosis in a female patient with multiple sclerosis and HIV infection is described.

[Transverse myelitis syndrom as a result of neuromyelitis optica spectrum disorders, systemic lupus erythematosus and myasthenia gravis combination]

Neuromyelitis optica spectrum disorders (NMOSD) - autoimmune condition characterized by an inflammatory lesions mainly of the spinal cord with the development of longitudinally extensive transverse myelitis (LETM) and/or involvement of the optic nerve with the development of usually bilateral optical neuritis (ON). In recent years, there has been increased awareness that NMOSD can be combined with other autoimmune diseases, including myasthenia gravis (MG), systemic lupus erythematosus (SLE) et al. The simultaneous presence of several autoimmune diseases in one patient can adversely affect the course of each of the diseases, causing the so-called mutual burden or «overlap syndrome». In this article, we describe our own clinical observation of a 51-year-old woman of European origin who developed acute relapsing TM seropositive for AQP4-IgG, by 23 years after the diagnosis of generalized MG seropositive for antibodies to acetylcholine receptors (AChR-Ab) and the occurrence of SLE, criterially confirmed, several months after the initial TM attack. During the fourth TM attack, partial positive dynamics was achieved only against the background of the combined use of intravenous methylprednisolone (pulse therapy), high-volume plasma exchange, rituximab and cyclophosphamide. The NMOSD is a rare disease leading to severe disability. In patients with MG, when symptoms of damage to the central nervous system appear, an analysis should be performed for AQP4-IgG and possibly for antibodies to myelin glycoprotein of oligodendrocytes (MOG-Ab), as well as markers characteristic of systemic connective tissue diseases (SCTD). In patients with STDD, when symptoms of involvement nervous systemappear, testing for AQP4-IgG (and, if necessary, for MOG-Ab) should be performed to exclude NMOSD, as well as AChR-Ab (and, if necessary, antibodies against muscle specific kinase (MuSK-Ab)) to exclude MG.

[The effect of inbreeding on accumulation of complex diseases in genetic isolates]

We have studied the effect of genetic processes in ethnically and demographically diverse isolates on the epidemiology of complex diseases. Our long-term studies of five indigenous Dagestan ethnic groups have revealed ten genetic isolates with aggregation of schizophrenia-related diseases. According to Neel's classification (1992), these isolates belong to primary and secondary depending on the duration of demographic process. We have found that the average demographic ages of the examined primary and secondary isolates were about 4000 and 700 years, respectively. The inbreeding level F was studied using two methods: analysis of marriage structure in three generations, which is traditional in population-genetic studies, and analysis of the same structure in extensive pedigrees (up to 11-13 generations). We have shown that with the second method, the F value increases two- to three-fold in various isolates. The accumulated inbreeding in the primary isolates proved to be twofold higher than that in the secondary ones. Primary isolates have revealed relatively higher genetic and clinical homogeneity in combination with higher aggregation of population-specific complex disease pathology compared to secondary isolates. A decrease in observed recombinations and the number of genomic loci linked with the disease in primary isolates have been also demonstrated. Thus, our studies showed that complex diseases can be less expensive and mapping of genes for time-consuming if conducted in primary rather than in secondary isolates, in particular when dealing with genetically heterogeneous outbred human populations.

Ethnogenomic diversity of Caucasus, Daghestan

Autosomal short-tandem repeats (STRs) were typed in ethnic populations of Kubachians, Dargins, Avars, Lezgins, Kumiks, and Nogais of the Caucasus (Daghestan, Russia) at the University of Utah. Daghestan ethnic populations demonstrated differences in STR allele frequency distributions, but these differences were much lower among these ethnic groups compared to worldwide ethnic groups. The observed genetic diversity was low while F(ST) values were high, both of which provided supporting evidence for small population sizes and high levels of isolation among the ethnic groups. An analysis of genetic distance from the three major continents, encompassing Daghestan populations and groups, reveals three distinct clusters: all populations of African affiliation, European and Daghestan populations except the Nogais, and Asian populations with ethnic Nogais.

[STR polymorphism in populations of indigenous Daghestan ethnic groups]

Genomic diversity of 21 STR loci has been studied in six ethnic populations of Daghestan (the Caucasus), namely, Avars, Dargins, Kubachians, Lezgins, and Nogais, and the results have been compared with these data for European, African, and East Asian ethnic groups. Daghestan is unique in its ethnic diversity, which is the greatest in the Caucasus: 26 out of approximately 50 autochthonous ethnic groups of the Caucasus live there. The genetic origin of this wide ethnic diversity of Daghestan and the Caucasus as a whole is still obscure. The genetic heterogeneity of Daghestan populations has been found to be lower than that of most other populations in the world. This is explained by a prolonged isolation and gene drift in their demographic history. Generalized genetic distances between ethnic groups calculated for the whole set of loci studied allow differentiating Asian populations from African ones, with European populations occupying intermediate positions. All Daghestan ethnic populations form a distinct common group together with some European populations (Finnish, Polish, and French). Nogais are genetically close to Southeast Asian populations. The genetic closeness and the apparently equal genetic diversity of Daghestan and European populations suggest that the ethnic differentiation of the ancestral populations of Daghestan and European ethnic groups occurred in the earliest populations of modern humans.

[Genetic and epidemiological studies in Dagestan highland isolates]

Interpopulation differences in the epidemiology and age of onset of complex diseases, as well as expression of some vital parameters, have been found. The relationship between these interpopulation differences and the genetic processes that have been occurring in the populations throughout their history has been demonstrated. The Daghestan genetic isolates studied are characterized by aggregation of certain complex diseases. In each genetic isolate, almost all affected subjects with homogeneous clinical phenotypes belong to the same large pedigree with a limited number of founders. There is evidence for a large variance of the population risk of schizophrenia (morbid risk) in Daghestan isolates (this parameter varies from 0 to 5%). Examination of 211 cases of schizophrenia earlier diagnosed in Daghestan psychiatric hospitals has shown that only 139 of them meet the DSM-IV criteria for schizophrenia. The remaining 72 subjects have, according to DSM-IV criteria, various schizoaffective and affective disorders; all of these subjects are close relatives of the schizophrenic patients. The age of onset of schizophrenia in the isolates studied varies from 14 to 40 years (20.84 +/- 0.568 years). Offspring of consanguineous marriages exhibit later age at onset and a higher risk of schizophrenia than offspring of exogamous marriages. The results of multivariate genetic analysis indicate that different gene complexes are involved in the pathogeneses of early-onset and late-onset forms of schizophrenia. An association of schizophrenia incidence, its age dependence, and reproductive parameters with polymorphisms of some microsatellite loci have been demonstrated.

[Genetic subdivision of Dagestan ethnic populations]

Relationships between ethnic and genetic differentiation with respect to 54 microsatellites have been analyzed in five Daghestan ethnic groups. To detect the microsatellites, human chromosomes 3, 17, and 18 were screened with a step of 10 cM (Weber/CHLC 9.0 markers) at the Mammalian Genotyping Service (National Institute of Health, United States). Comparison of the polymorphism of these loci in Daghestan populations with average worldwide data has revealed generally low heterozygosity in Daghestan populations, which is accounted for by traditional endogamous and consanguineous marriages throughout the history of these populations. The inbreeding coefficient in Daghestan ethnic groups varies from 0.005 to 0.0134 and is close to the worldwide maximum known to date. For some DNA loci, significant differences between the offsprings of consanguineous and exogamous marriages with respect to allele sizes and their variance have been found. The Daghestan ethnic populations studied differ from one another in both the frequencies of common alleles and the presence of rare alleles that are unique for each ethnic group of Daghestan and have not been found in any other population in the world.

[Mapping genes of complex diseases in genetic isolates of Dagestan]

Original results of the analysis of genetic linkage between some genomic markers and two complex clinical phenotypes, schizophrenia and mental retardation, in pedigrees from Dagestan genetic isolates are described. Interpopulation differences in the epidemiology of the complex phenotypes were studied and in their genetic linkage was demonstrated. These differences are evidently related to the genetic structure of the isolates determined by their genetic history. The MR epidemiological index characterizing the lifetime morbid risk of schizophrenia varies in the Dagestan isolates studied from 0 to 4.95%, which is almost five times higher than the average worldwide population rate, 1%. Comparative genetic mapping permitted determination of the most probable genetic linkages and associations of loci from chromosomal regions 17p11.1-12, 3q13.3, and a locus from 22q with schizophrenia and locus 12q23 with mental retardation. There is evidence that this approach is effective for detailed study of the relationship between the genetic (allele and locus) and clinical heterogeneity of complex diseases, which favors successful identification of the genes determining them. The study of linkage disequilibrium (LD) in genetic isolates of Daghestan populations (which have a common genetic background) may be an effective methodological approach for revealing the numerous contradictory results of mapping of the same genes of complex disease performed by different researchers in different regions of the world.

The ascertainment of multiplex schizophrenia pedigrees from Daghestan genetic isolates (Northern Caucasus, Russia)

This article describes the preliminary ascertainment of multiplex schizophrenia pedigrees from the isolated mountain region of Daghestan (Northern Caucasus, Russia). Daghestan has a population of two million people and contains 26 aboriginal ethnic groups. Many of the ethnic groups reside in remote mountain villages that can be classified as 'primary isolates'. Prolonged reproductive isolation and severe environmental conditions in the highlands have created diverse, genetically isolated ethnic populations in Daghestan. A number of the isolates in this region contain large extended multiplex schizophrenia pedigrees that are ideal for genetic analyses. During summer expeditions of 1996 and 1997, 14 separate large multiplex schizophrenia pedigrees were ascertained from 14 different mountain villages. Of the 14 kindreds, one had 50 schizophrenic cases available for ascertainment, one had 32, and another had 24. Seven of the remaining pedigrees had between 11 and 23 living cases. Within the kindreds, the number of males with chronic schizophrenia was at least twice that of females. The average age of onset of schizophrenia is 21.2 years for offspring of consanguineous marriages and 17.4 years for offspring of nonconsanguineous marriages (P = 0.033). Although the pedigrees ascertained from the remote mountain villages may not be representative of the general population, they are unique kindreds for mapping schizophrenia susceptibility genes.

[Comparative study of genetic adaptation of the Caucasian highlanders to historic and to the new urban environments]

Marriage structure and female reproductive characteristics in a highland isolate and an urban population from Dagestan were compared. The studied urban population could be divided into three groups according to ethnic, genetic, and demographic parameters. In the native, highland population, a steady selection occurred due to a high, uncontrolled birthrate and a high prereproductive mortality. The genetic structure of the urban population still remained at the stage of formation. Different ethnic groups of the female urban population differed both in the rate and directions of selection. The migration of highlanders to the city mainly affected their mortality and morbidity, but not fecundity. The subpopulation of migrants from the highlands who retained a traditional endogamous and inbred marriage structure exhibited a high infant mortality comparable to that in the highland population. The migrant subpopulation in which interpopulation and interethnic marriages were contracted exhibited an increased genetic load expressed as high pre- and perinatal mortalities. The results obtained are discussed in terms of the hypotheses on the adaptive gene complex and the genetic and physiological mechanisms of differential adaptation of highland isolates to environmental changes due to migration or environmental pollution.

[Genetic polymorphism in three indigenous ethnic populations of Dagestan]

Genetic, demographic, and biochemical studies of three isolated ethnic populations of Dagestan were performed. Two populations lived in their historical (highland and lowland) habitats, and one population migrated from highlands to lowlands, i.e., changed its environment. A substantial genetic differentiation with respect to eight biochemical systems and marital structure was found. Altitudinal variation was revealed in allelic frequencies of group-specific component (GC) and haptoglobin (HP). The frequency of allele GC * 1 decreased and that of allele HP * 1 increased as the altitude increased in the studied localities. The studied populations differed with respect to the average heterozygosity levels per locus. Both absolute heterozygosity levels and the pattern of interpopulation differences estimated for all of the eight biochemical markers considerably differed from those estimated for all markers except for GC and HP. These data indicate that the latter two biochemical systems are important for adaptation of the studied Dagestan populations. In surviving migrants from highlands to lowlands, the levels of inbreeding and genetic polymorphism were intermediate between these values for highlanders and native lowlanders. Earlier, the 30% selective mortality was revealed in migrants from highlands to lowlands during the first years of adaptation to new conditions. Those individuals who died had a higher inbreeding level, homozygosity, and physiological sensitivity. In this study, only surviving migrants were examined. Therefore, it may be suggested that the inadaptive (dying) part of migrants also differed from the adaptive (surviving) part in the higher HP * 1 and GC * 2 allelic frequencies.

[Clinical and pathogenetic features of exposure of workers to antimonate ore]

A total of 100 miners exposed to antimonate dust concentrations considerably exceeding the MAC were examined, and 16% of the subjects appeared to have chronic bronchitis. No pneumoconioses were diagnosed. The chronic bronchitis was characterized by mild slow course with I degree of ventilation disturbances. Antimonate ore turned out to induce toxic effects and activate some protective mechanisms: phagocytosis, immune response, inhibition of proteases.

[A genetic and demographic study of Dagestan highland populations and migrants to the lowlands. The relationship between levels of consanguinity, homozygosity and physiologic sensitivity]

This is a continuation of a series of papers devoted to studying the genetic mechanisms of adaptation in migrants from isolated highland populations of Dagestan to new ecological conditions (lowlands). This paper describes the main results of studying the relationship between levels of inbreeding, homozygosity, and physiological sensitivity. Earlier, we found that decreased resistance to changing environmental factors in migrants to lowlands from the Dagestan highlands was connected with their high level of homozygosity. The data obtained allow us to assume that missing links in this chain of events include, in addition to parameters of inbreeding level, parameters of neurophysiological sensitivity, including absolute and differential sensitivity of various analyzers sensory systems, which are from 65 to 75% genetically determined. Migrants from highland auls (villages) to lowlands exhibited a decreased rate of sensomotor reactions in response to light and sound of various intensities, as well as decreased differential color sensitivity in the long-, medium-, and short-wave ranges of the spectrum, compared to highlanders. The results suggest the selective mortality of migrants from highlands to lowlands during adaptation to new conditions. Those migrants who dies were characterized by specific gene complexes that determined the characteristic features of expression of a number of interrelated polymorphic and quantitative traits. Thus, the high levels of homozygosity and inbreeding were accompanied by a greater neurophysiological sensitivity and lower indices of body weight and height.

[Genetic-demographic study of mountain populations from Dagestan and their migrants to the lowlands. Comparison of basic parameters of fitness]

Results of a total genetic demography study of females of postreproductive age from both parts of "splits" highland isolates of Dagestan, highlanders, and migrants to lowlands are described. The components of natural selection that were related to differential mortality and differential fertility were estimated in the highlanders and the migrants using Crow indices. Offsprings of female migrants were characterized by a higher prenatal (spontaneous abortions and still-births) and a lower prereproductive mortality. These differences may be accounted for by two mechanisms: (1) the effects of changing marital structure (female migrants are more exogamous) and (2) better medical care for the children of migrants compared to those living in highland auls (settlements), which are still difficult to access. It was demonstrated that mortality of probands' children before reproductive age, as well as the proportion of their close genetic relatives that died within five years after resettling, increased with an increase in the level of individual inbreeding in women examined (probands). These data allow us to suggest that the drastic increase revealed in mortality of the highlanders during the first years after resettling may be partially attributed to high levels of inbreeding and heterozygosity; these, in turn, decrease the individual's nonspecific resistance to new ecological factors. Fertility and prenatal mortality appeared to increase and decrease, respectively, with an increase in the inbreeding level.

[Genetic-demographic study of mountain populations of Daghestan and migrants from it to the lowlands. Study of genetic and marital structure]

The results of a genetic and demographic study of two "split" isolates of small native ethnic groups of Daghestan are described. Parts of these populations were resettled from habitual highland ecological conditions to radically new lowland conditions in the 1940s. These split isolates were compared with a population of native inhabitants of the Daghestan lowland. It was found that, since resettling, separated populations originating from split isolates became significantly different in both marriage and genetic structures. This is manifested in different phenotypic and allelic frequencies of a number of physiological and biochemical markers and in levels of their heterozygosity. To explain the differences revealed, a hypothesis was proposed about the relationship between levels of inbreeding, heterozygosity, and physiologic sensitivity that account for the differential adaptability of members of the isolated populations to changing environmental conditions. This is the first report of a series of papers describing the experimental testing of this hypothesis. While testing the validity of the hypothesis in this study, a positive linear correlation was found between inbreeding and homozygosity levels.

Phenotypic and genetic affinities among ethnic populations in Daghestan (Caucasus, Russia): a comparison of polymorphic, physical, neurophysiological and psychological traits

Daghestan contains many distinct populations characterized by different degrees of isolation, ethnic backgrounds and ecological conditions. This report introduces a large-scale family study conducted in seven Daghestan populations as well as in Moscow, using four categories of measures: (1) single gene polymorphisms, (2) anthropometric, (3) physiological, and (4) psychological quantitative traits. Such a study permits the analysis of both phenotypic and genetic variation within and between populations. The implications of such variation are discussed, especially in the context of the measures used. These derive from Soviet conceptualizations of the nervous system and related assessment of individual differences, and vary considerably from conventional Western approaches to behaviour. From the anthropometric through the physiological to the behavioural measures there was a clear trend towards increased phenotypic variation but reduced genetic variation. Possibly because the genetic variance was less on the more complex phenotypes, measures of generalized distance indicated much greater population similarity when based on phenotypic data on the genetic component of variation. Issues that arise when using behavioural traits to study human population diversity are discussed, particularly in relation to inbreeding and the specific cultural and linguistic practices in the Daghestan region.

Behavior genetic differences within and between defined human populations

The small populations of the Caucasus offer a unique opportunity to consider concepts, such as heritability, which are often considered properties of a trait but which are really properties of a population. A comprehensive strategy is outlined for studying intra- and interpopulation genetic structure across a wide range of traits and environments. A three-way association is demonstrated between 12 of 16 psychophysiological traits, attitude, and the t allele for PTC sensitivity. Differences between populations and traits are evaluated in theoretical terms for morphological, physiological, and psychological measures. While decreases in performance with inbreeding are often predicted, in these small, isolated populations the effects are minimal.

Visual evoked potentials: phenotypic and genotypic variability

Evoked potentials (EPs) provide a unique way of analyzing the relationship between genes and behavior. Individual differences in EPs, in response to light flashes of two intensities and pattern reversal, were studied in families from the isolated population Mechelta in the Northern Caucasus. While there were no age or sex differences in EP latency, or many age effects on amplitude, there were sex differences on the amplitude measures. Variation in the additive genetic determination of latency and amplitude measures is discussed. The largest estimates of additive genetic variation were found for the complexes of amplitude measures between the positive and negative waveforms.

[Hyperbaric oxygenation in the comprehensive rehabilitation of seamen after a long sea voyage]

It is established that 10 sessions of hyperbaric oxygenation in complex with balneologic procedures (Finnish baths) compensate the relative oxygen insufficiency and stimulate the redox processes of the sailor organism when transferring to a new functional level after long voyages. It is concluded that hyperbaric oxygenation is worth-while to restore working capacity and to rehabilitate the crews in the period after long sailing.

[Principles and methods of occupational psychophysiological selection of deep-water divers]

A complex of methods is suggested for professional psychophysiological selection of deep divers: the count of signals under time deficit conditions, simple and complex coordination of analyzers function, tepping test, the study of attention concentration using the Ivanov-Smolensky tables and finding of numbers with switching. This complex together with assessment of number range by deviation method allows making correct prediction during selection of specialists with high probability equal to 0.9. The efficiency of professional selection increases due to the reliable correlation between the results of psychophysiological research and predisposition to development of decompressive disease.

[Structural and functional aspects of erythrocyte membrane in children, delivered with asphyxia]

Serum and red blood cell membrane lipid peroxidation (LPO), antioxidative activity (AOA) of the ceruloplasmin/transferrin (CP/TF) system, and biophysical parameters of the structure of a red blood cell membrane lipid bilayer were examined in fetuses experienced acute hypoxia at birth and in babies born to healthy mothers with uncomplicated pregnancy. The intensity of LPO product accumulation in mild asphyxia was ascertained to be proportional to the duration of hypoxic exposure of a fetus. In severe asphyxia accompanied by lower formation of primary LPO products, the levels of secondary LPO products showed a rise. A slight increase of AOA in the CP/TF system was unable to adequately compensate a high intensity of LPO processes, which provides strong evidence for altered structural parameters in the lipid bilayer. It was concluded that it was essential to correct hypoxic states in children with antioxidants immediately after birth.

[An immunochemical analysis of the function of the hemato-encephalic barrier in acute fetal hypoxia and asphyxia neonatorum]

The neurospecific protein alpha 1-globulin has been assayed in serum in order to evaluate the blood-brain barrier in newborns with acute intrapartum hypoxia. The study involved 35 term newborns with birth asphyxia of variable severity. The alpha 1-globulin levels correlated with severity of condition at birth, duration of intrauterine exposure to hypoxia and the presence of obstetric complications and clinical severity of cerebral circulatory disorders. A normal early adaptation and effective therapy reduced serum alpha 1-globulin levels 4-8-fold on the 3rd postnatal day and 6-16-fold on the 5th day. Deterioration of neurological symptoms was parallelled by a significant increase in protein levels (to 6400 ng/ml) at day 5. This evidence may confirm the fact that permeability of the blood-brain barrier is impaired by intrapartum hypoxia.

Population-genetics approach to the genetics of human behaviour

Invariant values of inheritance factors within and between different populations can show the existence of and measure the degree of genetic determination of behavioural characters. The absence of inbred depression of quantitative behavioural characters in isolated populations of highland inhabitants of Daghestan is demonstrated by means of comparative analysis of the mean population values of psychophysiological characters in outbred, moderately isolated, and extremely isolated (and inbred) populations. The absence of pronounced adverse effects of inbred marriages, known as the 'Daghestan phenomenon', is explained by the antiquity of the native populations and the severe ecological conditions under which these populations live which have led to elimination of carriers of hereditary diseases and other detrimental phenotypes.

[Indicators of lipid metabolism and aminotransferase activity in girls with dysfunctional uterine hemorrhage]

In a study of 42 girls, aged 12 to 15 years, including 27 patients with dysfunctional uterine bleedings (DUB) and 15 normal controls, the levels of glucose, total lipids, beta-lipoproteins, total cholesterol, as well as beta-lipoprotein, triglycerides, nonesterified fatty acid (NEFA) cholesterol and aminotransferrase activity were compared. NEFA levels were found to be increased fivefold over the normal values in DUB patients.