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I Dimitrov

Publications and source records attributed to I Dimitrov.

At least 19 recordsLinked to original sources
PubMed2006

Hypergravity as a crystallization tool.

The centrifugal increase of concentration is nondestructive, rapid, and simple technology. Therefore it is used to create a higher supersaturation that is required for crystal nucleation, as the one that is appropriate for the subsequent growth. Crystal nucleation is evoked in glass capillary tubes filled with protein solutions. The couple ferritin/ apoferritin is used as model proteins in the present article. Although differing in their masses the two (quasi) spherical molecules have exactly the same size and surface properties. Together with the temperature-independent solubility this makes them very convenient for our investigations. Decoupling nucleation and growth, for example, by means of hypergravity makes it possible to grow quasi-equidimensional crystals. The use of monodisperse crystalline forms of therapeutic agents can ensure constant time-release of protein-based medications.

Animals↗
PubMed2003

Cerebellopontine angle meningiomas. Clinical features and surgical treatment.

AIM: The aim of this study is to present the clinical picture of patients with cerebellopontine angle meningiomas and analyze the results of their operative treatment. METHODS: A retrospective study of patients with cerebellopontine angle meningiomas operated consecutively in our department over an 11-year period has been carried out. Data regarding their clinical features, surgical treatment, morbidity, mortality and outcome have been analyzed. Forty-four patients with cerebellopontine angle meningiomas were operated during the period 1991-2001 (intervention: tumor removal via the retrosigmoid suboccipital approach). MAIN OUTCOME MEASURES: clinical condition, MRI/ CT imaging. RESULTS: The median duration of symptoms prior to diagnosis was 44.5 months. The most frequent initial complaints were hearing loss, tinnitus and headache. Most frequent symptoms and signs at presentation were cerebellar, followed by hearing loss and trigeminal nerve symptoms. In 98% of the cases the operative approach used was the retrosigmoidal suboccipital. Total tumor removal was achieved in 55%. After total tumor removal no recurrences have been observed. The mortality rate was 2%. CONCLUSION: The application of different classification schemes complicates the comparison between published series. The outcome depends on their location, consistency, size and relation to the surrounding neurovascular structures. In our experience the retrosigmoid suboccipital approach is most appropriate for their surgical treatment. It offers the possibility to remove completely even large meningiomas and avoids the risk of recurrences.

Adolescent↗
PubMed2003

[Factors influencing successful rate of intrauterine insemination].

Intrauterine insemination (IUI) is a method for the treatment of marital infertility involving the intrauterine or fallopian deposition of washed spermatozoa, depending on the amount of inseminated semen. Numerous factors may be affect of pregnancy rates after IUI.

Bulgaria↗
PubMed2002

Totally chlorine-free bleaching of flax pulp.

Alkaline-sulphite Tamlin flax mill pulp of 34-41% brightness has been bleached with different totally chlorine-free (TCF) sequences (oxygen delignification, pressurised peroxide, peroxide without and with activator (TAED, tetraacetylethylenediamine) and with and without pre-treatment with ultrasound to 82% ISO brightness of the mill conventional CEH bleaching. Although the best results after oxygen delignification were obtained with pressurised peroxide, activated peroxide caused lower cellulose degradation and gave a higher pulp strength. The effects of temperature, retention time, chemical charge, TAED/peroxide ratio and alkalinity have been studied in order to maximise the brightness gain at lower viscosity loss. The chemistry and flexibility of TAED made it possible to activate the peroxide under conditions for which the peroxide alone is ineffective as a bleach, such as low alkalinity or low temperature. The presence of shives hindered the bleaching, but the bleached non-screened pulp was stronger than the screened one. Pre-treatment with ultrasound for 4 min of 1% pulp consistency gave 3-4% gain in ISO brightness for non-screened pulp and 2% for screened pulp and facilitated further delignification and peroxide bleaching.

Acetamides↗
PubMed2000

[Use of frozen human semen].

The necessity of establishing of monitored donor's genetic bank in Bulgaria is of exceptional necessity at the moment, when health care in our country is in reorganization and is set on a new base. Our studies were directed towards the organization of bank for cryopreservation of spermatozoa taken of: Donor's genetic material for the needs of obstetric and gynaecological laboratories From men that are expected to go through an X-ray or chemical treatment because of tumors or are planned for operation of the testicules. The genetic bank in IBIR is organised accordance with Bulgarian Legislation.

Bulgaria↗
PubMed1999

Age at marriage and intrafamily planning in young families.

INTRODUCTION: The sociological inquiry on current problems of intrafamily planning carried out in 1995 provided opportunities for finding the effect of a number of social and demographic factors on the formation of family. OBJECTIVE: The present study has investigated the influence of the age of woman at marriage on the main indicators characterizing the reproductive behavior. MATERIAL AND METHODS: Direct individual inquiry was performed and 500 young families from the town of Plovdiv were approached. Data were analyzed by percentage distribution methods and non-parametric tests. RESULTS AND DISCUSSION: We should note here the high percentage of spouses who had not planned the number of children in their future family--33.1% of women and 34.3% of men. Paradoxically, the percentage of women that had not planned the number of children in their families increases with age. The intended number of children does not depend on the age of women at marriage. The women aged below 19 have indicated the highest number of children. The "ideal number of children" indicator has the highest value in women aged below 19 (2.25 children), but there is no statistically significant difference in the ideal number of children between the different age groups. The opinion about a "large family" is studied in spouses and relatives of the young family. With the increase of age, the number of children in the "large family" decreases in all three groups (P < 0.001). There is no difference in length of the protogenetic interval between different age groups. Intergenetic interval between the first and second birth is about three years in all three age groups. The largest interval between the second and third birth is registered in women aged above 25. About half of the women have admitted that they do not wish to have a third child. The age at last delivery is highly correlated with age at marriage (P < 0.05); the correlation is strongest in women above 25 years of age.

Adolescent↗
PubMed1999

Influence of family tradition on reproductive behavior of Gypsy population.

INTRODUCTION: Stability of traditional opinion in different ethnic communities determines to a great degree the demographic behavior of their members. AIM: To analyze the influence of family traditions and system of values on the reproduction of gypsy population. MATERIALS AND METHODS: The opinions of 495 Gypsy women in reproductive age was studied by direct individual questionnaire. The answers characterizing the reproductive behavior of two successive generations were analyzed. The following statistical analyzes were applied: descriptive statistics, chi-square and t-tests. All p-values are two-tailed. The statistical analyses were made on a PC using SPSS 5.0.2. RESULTS: Mean age at marriage in different generations under study was similar (it is 15.50 +/- 0.10 years in the present generation vs. 15.58 +/- 0.09 years in the previous generation, p > 0.05). The same is valid for the mean age at the first birth (16.98 +/- 0.11 years vs. 17.04 +/- 0.10 years, respectively, p > 0.05). However, there was a statistically significant difference in the mean number of live-births between the generations (2.37 +/- 0.05 vs. 4.10 +/- 0.09, respectively, p < 0.001). The latter finding might be explained by fact that the women from the present generation are still in their reproductive period. CONCLUSION: It is obvious that family traditions may have, to a certain extent, an influence on the patterns of reproductive behavior in gypsy population. These traditions represent an indispensable part of their lifestyle and their intentions to have many children.

Adult↗
PubMed1998

Sexual culture of gypsy population.

The number of the gypsy population in Bulgaria has increased with 85,419 persons for the period 1965-1992 that is higher than the prognosis made about a mean rate of increase of 2000 persons per year. The aim of the present study was to describe demographic changes and main problems of intrafamily planning of this population. The primary information was collected by the method of indirect individual inquiry as the opinion of 495 gypsy women at reproductive age was studied. Sexual behaviour of this ethnic group was analysed with the needs and social, economical and cultural status. The results have revealed particular patterns of the sexual behaviour about the beginning of early sexual relationships, use of modern contraceptive methods, number of abortions, etc. It should be noted that only about 61% from the gypsy women use any kind of contraceptive measures but irregularly. The mean number of abortions per woman was 2.41 and about 33% of women had undergone 3 and more abortions-on-demand. The low level of sexual culture and the lack of knowledge about the methods of contraception have led to early first births, high proportion of abortions-on-demand and high rate of increase of the population among gypsies. This may be explained by the life-style traditions of this ethnic group and their intention to the multi-child model of the family. We must emphasize the lack of modern information system for early warning, publicity and formation of sexual habits of this population.

Abortion, Induced↗
PubMed1998

Natural growth of the population of Plovdiv, Bulgaria for the period 1895-1995.

A study of the natural growth rate of the population using female cohorts by birth year has been carried out for the first time in our country. The study comprises 14 cohorts. The following characteristics are recorded: birth year, social group, educational level, number of live births, age of marriage, infant mortality rate, proto- and intergenetic intervals. Our report presents the key indicators of natural growth of population in the studied cohorts. A consistent trend of decreasing the number of livebirths is established. In the first studied cohort (1895-1899) the average number of offspring per woman is 3.94, reaching a level of 1.77 in the 1960-1964 cohort. The indicators for natural growth of population exhibit a similar trend. The summary fertility rate in the reference period decreases with more than 2 points--from 4.47 in 1895-1899 to 1.73 in 1960-1964. Likewise, the total reproduction rate goes down from 2.54 to 0.78 for the same period. Considerable changes have occurred in the indicators total period fertility rate and marriage fertility rate of women. For a period of 110 years the former has decreased 3.5 times, the latter--8 times. The drastic drop of the indicators of natural growth of the population is accounted for by an intricate complex of social, economic, psychological and biological factors. The marked aging of the population and the decrease of the percentage of women in active fertility age play a certain role in this process. The ascertained changes in the reproductive behavior and age structure of the female population are factors intensifying the unfavorable trends in the natural growth rate of the population in our country.

Adolescent↗
PubMed1997

Knowledge-based in vivo analysis of kidney concretions from digitized X-rays.

To make a right choice of a treatment approach in patients with nephrolithiasis it is very important for the clinicians to know the composition and structure of calculus. Conventional radiographic techniques and computerized tomography (CT) give information about the location and size of concretions, but not for their composition and structure. In the present study we investigated the gray-level values of chemical substances in concretions. It was established the appropriate X-ray exposure for subsequent image analysis. A method for intracorporal analysis of composition and structure of kidney concretions is proposed.

Artificial Intelligence↗
PubMed1997

Attitudes towards alcohol use among Bulgarians-Christians and Turks-Muslims.

The attitude towards drinking in a given culture plays a very important role in the use and abuse of alcoholic beverages. The purpose of our study was to examine and compare this attitude among the Bulgarians-Christians and Turks-Muslims in Bulgaria. The sample comprised 618 subjects--316 Bulgarians-Christians and 302 Turks-Muslims, selected by means of a randomized cluster design. The sample was stratified by ethnic identity, gender, age and place of residence (town vs. village). This methodology provided us with a way of controlling these confounding variables. The survey was conducted with a standardized questionnaire designed specifically for the study. The findings show that a greater percentage of Turks-Muslim than of Bulgarians-Christians (including those respondents who regularly use alcohol) are in favour of an official prohibition of alcohol in society and even moderate use on special occasions is inadmissible to them. Women, rural residents, people with lower educational status, senior citizens and those to whom religion plays an important part in their lives predominate in the social structure of the Turkish sub-sample favouring official prohibition. Their cultural readiness to say "No" to alcohol is viewed in the context of the abstinent Islamic culture.

Adolescent↗
PubMed1997

Sociobiological factors and physical development of newborn infants in Plovdiv.

On the basis of data from a study, conducted in 1995 in Plovdiv, the correlation between newborn infants' physical development characteristics and some biological and social factors (maternal age, number of pregnancies, birth order, social class and educational level) was analyzed. Four basic anthropometric indices--height, body weight, head and chest circumferences were examined. The anthropometric indices of newborn infants in Plovdiv are the highest in second or third pregnancies. Birth order exerts significant influence on the physical development of newborn infants--the highest values are recorded at the second birth. The anthropometric indices are clearly dependent on mother's age. They increase with maternal age and reach their maximum in age group 30-34 years. The anthropometric indices values equalized in newborn infants from mothers--white and blue collar workers, while the values are significantly lower in newborns of unemployed mothers. Newborn infants' physical development of mothers with primary and high-school education is significantly inferior compared to children of mothers with higher educational levels.

Adult↗
PubMed1997

Accelerative changes in some anthropometric indices of newborn infants in Plovdiv during the period from 1939 to 1995.

Periodical observation and comparison of newborn infants' physical development indices gives an idea of the dynamics of accelerative changes and the efficacy of implemented health and social programs for maternity protection in a given country. The author performs a longitudinal study of the basic anthropometric--birth height and weight of newborn infants in Plovdiv for a 56 year period. Two periods are outlined. The first one, 46 years long, is characterized with a marked increase of the anthropometric values and lasts till 1975. After that the acceleration rate levels off and gradually slows down. In the second 10 year period an abrupt decrease of newborn infants' birth height and weight is recorded, as their values drop to the levels obtained in the 1946/47 study. The author relates this negative trend to the economic crisis in the country, the progressive impoverishment of the population, the unemployment and insecurity in the future. The existing social and health facilities for maternity protection in the country are estimated as inadequate for the present situation.

Anthropometry↗
PubMed1997

[An analysis of the indications for episiotomy in current obstetrical practice].

The aim is to analyze the accepted indications for episiotomy in nowadays practice. The investigations is retrospective for the period from April to May 1996. The material includes 459 term singleton pregnancy in vertex presentation and 46 cases of premature neonates with weight from 1300 to 1499 g. The results show high risk (77.1%) of episiotomy in nulliparous women. The multiparity, the length of second period and the high risk pregnancies have not effect on the use of episiotomy. The wight of the fetus is essential factor. The highest rate of episiotomy is at premature births (65.2%) followed by the group of neonates with weight over 4000 g (61.5%). The lowest rist of episiotomy is then the weight of newborn is between 2500 and 3800 g (21.8%). Almost hundred percent rate of episiotomy in operative vaginal and breech deliveries show that we accept the episiotomy as obligatory of these vaginal deliveries.

Adult↗
PubMed1997

[The results of the limited use of episiotomy in managing the second stage of labor].

The purpose is to asses the effect of restrictive use of mediolateral episiotomy on the spontaneous laceration of the low birth canal. The material includes 613 labors some of which gave birth with indication for episiotomy and control group of 441 retrospective cases with routine management of the second period of labor. The restrictive use of episiotomy decreases the rate from 45.6% in the routine practice to 32.8%. The reduced rate of episiotomy has as a consequent increase rate of second degree perineal laceration adn insignificant increase of vaginal lacerations. The management of restrictive and liberal use of mediolateral episiotomy has not effect on third and four degree perineal laceration, on the accessory tears of the vagina and on the rate of perineotomy. If from all labors are subtracted operative deliveries, surgical intervention for repairing the laceration of the birth canal and pathology of the placental period the rate of labors without any intervention is only 13.3%. Our results suggest that labor nowadays is operative activity.

Bulgaria↗
PubMed1997

Preventive characteristics of socially-mediated diseases.

The purpose of the present study was to examine the lifestyle characteristics and preventive readiness of patients with behavior-related diseases (BRD). These are diseases caused by inappropriate behaviors, and which could be prevented by behavior techniques. The courses of these diseases run without notable subjective symptoms for lengthy periods of times. They are compared with an alternate group of diseases which are characterized by manifest subjective symptoms (DSS). The study was conducted with a standardized questionnaire specially designed for the purpose. A representative sample comprising 137 BRD patients and 199 DSS patients was selected in three regions of South Bulgaria. The BRD patients compared to their DSS counterparts showed a higher average age, a larger percentage of males and a greater dissatisfaction with life. In BRD patients, to a greater extent than in DSS patients, the cause of their dissatisfaction with life was the disease itself. There were no statistically significant differences between the two subsamples in lifestyles or in behavior when ill. In addition BRD patients were less interested in participating in preventive programs. These findings indicate that the effectiveness of preventive programs for BRD patients is largely predetermined by their low level of preventive readiness, and is one of the explanations for the widespread prevalence of these diseases in present-day Bulgaria.

Adult↗