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J Horácek

Publications and source records attributed to J Horácek.

At least 19 recordsLinked to original sources
PubMed2002

Effects of interchannel coupling in associative detachment: electron spectra for H+Cl- and H+Br- collisions.

We present experimental and theoretical energy spectra of the electrons detached in collisions of slow Cl- and Br- ions with atomic hydrogen. Nonlocal resonance theory predicts two kinds of features in the spectra: steplike structures associated with rovibrational onsets and steep rises associated with interchannel coupling, the latter being absent in a calculation using the simpler local-complex potential theory. Our experimental spectra confirm the presence of both types of structures and thus the necessity of including interchannel coupling to properly describe the product-state distribution.

Journal Article↗
PubMed2002

[Lyme borreliosis--incidence of serum anti-myelin antibodies].

The method of enzyme immunoassay (ELISA) was used for detection of antibodies against the basic protein myelin (antimyelin antibodies) for a group of serum samples (n 36) with positive anti-borrelia immunoglobulins IgG and IgM (ELISA-Borrelia afzelii) and their immune complexes (ELISA-PEG). Antimyelin antibodies (ELISA-Doxa Kit-Myelin Basic Protein Antibodies) were assessed in 31% (n 11) of examined serum samples of patients with the working diagnosis of Lyme borreliosis. Statistical analysis (p 0.07) confirmed a more frequent incidence of antimyelin antibodies in younger female subjects (age 31 years) as compared with a group of sera (n 25) where the authors did not record the formation of immunoglobulins against the basic myelin protein (age 51 years). Neither the value of titres nor the frequency of detected anti-borrelia IgG and IgM and immune complexes did not differ significantly in the two groups. From the assembled results ensues that in the course of Lyme borreliosis, in chronic affection of organs an autoimmune reaction may develop where the basic myelin protein is damaged (demyelinizatio) and subsequently antimyelin antibodies are formed.

Adult↗
PubMed2002

[Occurrence of congenital esophageal defects in the Czech Republic 1961-2000--incidence, prenatal diagnosis and prevalence according on maternal age].

OBJECTIVE: To present incidences of the oesophageal atresia or stenosis and their maternal age distribution. To analyse maternal age as a possible risk factor for the defects studied. DESIGN: Retrospective epidemiological study. SETTING: Institute for Care of Mother and Child, Prague, Czech Republic. METHODS: Retrospective epidemiological study of oesophageal atresia and stenosis using data from the population based register of congenital malformations in the Czech Republic over the 1961-2000 period. The main source of data for this paper is the database of congenital anomalies at the Institute for Care of Mother and Child in Prague (the 1961-1990 period) and the data analysed by the Institute of Health Information and Statistics (the 1987-2000 period). RESULTS: Out of the total number of 5,589,888 births in the Czech Republic in 1961-2000 period, 804 cases of oesophageal atresia and stenosis were registered. Mean incidence of oesophageal atresia and stenosis in the period under the study was 1.51 per 10,000 livebirths. In the 1991-2000 period an increase of incidences of this congenital anomaly was revealed in the Czech Republic. By application of the two-sided 95% CI, statistically significant correlation was found in women of 39 years of age and older. CONCLUSIONS: Statistically significant increase of risk (for age as a risk factor) was found in maternal age groups of 39 years of age and over.

Czech Republic↗
PubMed2002

[Diaphragmatic hernia from 1961 to 2000--incidence, prenatal diagnosis and prevalence according to maternal age].

OBJECTIVE: Presentation of diaphragmatic hernia in the CR in 1961-2000. Analysis of prevalence of these defects in different groups by maternal age. DESIGN: Retrospective demographic-epidemiological study. SETTING: Institute for the Care of Mother and Child, Prague. METHODS: The authors used data from nationwide registers of birth defects in neonates kept in the Institute of Health Information and Statistics of the CR during 1995-2000. Epidemiological analysis of the incidence of diaphragmatic hernia in the CR during 1961-2000 in newborn infants. Mathematical statistical analysis of prevalence of these defects by maternal age using the method of 95% confidence interval of probability. RESULTS: In the CR during 1961-2000 1321 cases of diaphragmatic hernia were recorded. The mean incidence of this defect during the entire period was 2.32 per 10,000 live born infants incl. prenatally diagnosed cases and terminated pregnancies. Including those it was 2.37 per 10,000 live born infants. CONCLUSION: The authors elaborated the mean incidence during the investigation period and in individual years in born children as well as prenatally diagnosed cases. Also an analysis of the prevalence of these defects by maternal age was made using the method of 95% confidence interval. The authors found a significantly higher risk of development of this defect in foetuses of women aged 38, 42 years or older as compared with the population average. However an unequiwocally increased risk associated with more advanced age was neither confirmed nor ruled out.

Czech Republic↗
PubMed2002

[Congenital renal defects from 1961 to 2000--incidence, prenatal diagnosis and prevalence according to maternal age].

OBJECTIVE: Presentation of agenesis/hypoplasia of kidneys and cystic kidneys in the Czech Republic during 1961-2000. Analysis of prevalence of these defects in different groups by maternal age. DESIGN: Retrospective demographic-epidemiological study. SETTING: Institute for the Care of Mother and Child, Prague. METHOD: The author used data from the nationwide register of birth defects in neonates, kept by the Institute of Health Information and Statistics in the CR during 1990-2000. Epidemiological analysis of the incidence of agenesis/hypoplasia of the kidneys and cystic kidneys in the CR during 1961 to 2000 in cases diagnosed prenatally and in born children. The authors made a mathematical-statistical analysis of the prevalence of these defects by maternal age, using the method of calculation of the 95% confidence interval of probability. RESULTS: In the CR there were during the period from 1961-2000 1093 registered cases of agenesis/hypoplasia of the kidneys and 1370 cases of cystic kidneys. The mean incidence during the entire period was 1.81 in agenesis/hypoplasia of the kidneys and 2.26 in cystic kidneys per 10,000 live born infants. After adding prenatally diagnosed cases and pregnancies terminated on that account it was 2.05 a 2.58 per 10,000 live born infants. CONCLUSION: The investigation of these inborn defects did not confirm nor rule out statistically a higher risk of women older than the population average.

Czech Republic↗
PubMed2001

[Persistence of Borrelia burgdorferi sensu lato in patients with Lyme borreliosis].

In 18 patients with Lyme borreliosis the authors proved the persistence of Borrelia burgdorferi sensu lato by detection of the causal agent by immune electron microscopy or of its DNA by PCR in plasma or cerebrospinal fluid after an interval of 4-68 months. Clinical manifestations common in Lyme borreliosis were present in only half the patients, in the remainder non-specific symptoms were found. In nine subjects with confirmed Borrelia burgdorferi sensu lato in the cerebrospinal fluid the cytological and biochemical finding was normal. Examination of antibodies by the ELISA method was negative in 7 of 18 patients during the first examination and in 12 of 18 during the second examination. In all negative examinations the specific antibodies were assessed by the Western blot or ELISA method after liberation from the immunocomplexes. In the authors' opinion it is advisable to examine repeatedly plasma and other biological material from potentially affected organs by PCR and subjects with persisting or relapsing complaints after the acute form of Lyme borreliosis as well as to examine cerebrospinal fluid in case on non-specific symptoms and concurrent pathic EEG or MR findings.

Adolescent↗
PubMed2001

[Simultaneous occurrence of papillary carcinoma, oncocytic carcinoma and malignant lymphoma of the thyroid gland in a female patient with Hashimoto's disease].

A 51-year-old woman was admitted for a painless enlargement of the thyroid lasting over 6 months. Hashimoto's thyreoiditis was diagnosed and three tumors were found: oncocytic carcinoma, malignant lymphoma and papillary carcinoma. In the right lobe, oncocytic carcinoma and high grade malignant lymphoma composed of cells with irregular, lobulated nuclei were found. The lymphoma was confined to the thyroid gland. The oncocytic carcinoma invaded the capsule and the surrounding tissues. In the left lobe, there was a papillary carcinoma.

Adenocarcinoma↗
PubMed2000

Novel antipsychotics and extrapyramidal side effects. Theory and reality.

Novel antipsychotics are less likely to produce extra-pyramidal symptoms (EPS). The superior EPS profile of these drugs compared with that of low-potency classic antipsychotics does not seem to be associated with an antimuscarinergic effect. Several other mechanisms could account for this typical feature of novel antipsychotics, which combines a strong antipsychotic effect with low liability to produce EPS. The hypotheses are based on either the receptor affinity or the topic selectivity of the drugs, but these effects are closely interconnected and it is not possible to separate them. For clozapine treatment, its very low D occupancy could explain the absence of EPS, but this does not account for the low EPS with other novel antipsychotics. The direct topic selectivity for extrastriatal D2 receptors and different distribution of the drug in the brain is less probable. The most plausible hypotheses are based on the concept of indirect topic selectivity for extrastriatal D2 receptors, mediated by high affinity for extrastriatal D2 receptors (D3, D4), 5-HT2A antagonism, alpha1 antagonism or muscarinergic antagonism at the limbic level. The D1 and indirect GABAergic antagonisms may play a role in the prevention of tardive dyskinesia. This paper briefly outlines the hypotheses and observations and summarizes the current knowledge of the occurrence of and risk for extrapyramidal side effects with novel antipsychotics.

Antipsychotic Agents↗
PubMed2000

Resonance properties of the vocal folds: in vivo laryngoscopic investigation of the externally excited laryngeal vibrations.

The study presents the first attempt to investigate resonance properties of the living vocal folds by means of laryngoscopy. Laryngeal vibrations were excited via a shaker placed on the neck of a male subject and observed by means of videostroboscopy and videokymography (VKG). When the vocal folds were tuned to the phonation frequency of 110 Hz and sinusoidal vibration with sweeping frequency (in the range 50-400 Hz) was delivered to the larynx, three clearly pronounced resonance peaks at frequencies around 110, 170, and 240 Hz were identified in the vocal fold tissues. Different modes of vibration of the vocal folds, observed as distinct lateral-medial oscillations with one, two, and three half-wavelengths along the glottal length, respectively, were associated with these resonance frequencies. At the external excitation frequencies below 100 Hz, vibrations of the ventricular folds, aryepiglottic folds and arytenoid cartilages were dominant in the larynx.

Adult↗
PubMed2000

[Occurrence of cleft defects of the central nervous system in the Czech Republic 1961-1999. Incidence, prenatal diagnosis and prevalence based on maternal age].

OBJECTIVE OF STUDY: Presentation of the incidence of neural tube defects (anencephaly, spina bifida, encephalocele) in the Czech Republic in 1961 to 1999. Analysis of the prevalence of these defects in different groups by maternal age. TYPE OF STUDY: Retrospective demographic-epidemiological study. METHOD: Epidemiological analysis of the incidence of neural tube defects diagnosed prenatally and postnatally in the Czech Republic in 1961-1999. Mathematical and statistical analysis of these defects by maternal age, the method of 95% confidence probability interval was used. Data from the nationwide register of inborn defects were used assembled in the Institute of Health Information and Statistics of the Czech Republic and data on the prenatal diagnosis from different departments of medical genetics. RESULTS: In the Czech Republic in 1961-1999 4629 cases of neural tube defects were recorded. This number comprised 1812 cases of anencephaly, 2420 cases of spina bifida and 397 cases of encephalocele. Of this total number of notified defects 386 cases of anencephaly were diagnosed prenatally and pregnancy was terminated. In spina bifida thus 261 pregnancies were terminated prematurely, in encephalocele 67 cases. CONCLUSION: A significant reduction of the incidence of anencephaly, spina bifida and encephalocele in the Czech Republic was found during the last decade of the investigation period (1961-1999). This decline is most probably due to advances of primary and secondary prevention. When evaluating maternal age as one of the risk factors for the development of neural tube defects, this risk was neither unequivocally confirmed nor ruled out.

Abortion, Eugenic↗
PubMed1999

Effects of haloperidol treatment on prolactin response to D-fenfluramine challenge in acute schizophrenia.

We have previously described an association between higher serotonin (5-HT) responsivity, indexed by prolactin response to D-fenfluramine challenge, and poorer treatment response to haloperidol in non-medicated schizophrenics. The aim of the present study was to investigate the effects of antidopaminergic treatment on the prolactin response in the repeated challenge test. D-Fenfluramine was administered to 22 young, acutely ill schizophrenics (11 females and 11 males) after 4 weeks of haloperidol treatment. Whereas neuroleptic administration significantly raised basal prolactin levels (P < 0.0001), subsequent D-fenfluramine challenge produced an additional significant increase (P < 0.001). Moreover, the magnitude of this increase was not different from the pretreatment response. Our results demonstrate that prolactin response to the challenge is mediated through the 5-HT system. An observed negative association between posttreatment prolactin response and therapeutic response to haloperidol did not reach statistical significance.

Acute Disease↗
PubMed1999

The relationship between central serotonergic activity and insulin sensitivity in healthy volunteers.

In order to determine whether central serotonin (5-HT) activity is related to sensitivity of insulin receptors, 19 healthy volunteers with normal basal glycemia and HbAlc were studied. The relationship between prolactin response to D-fenfluramine (delta PRL) in a challenge test and metabolic clearance rates (MCR) of glucose during the hyperinsulinemic-euglycemic clamp technique was evaluated. delta PRL had been chosen as a correlate of central 5-HT activity. Two levels of insulin concentration of approximately 70 mU/l (MCRsubmax) and 2000 mU/l (MCRmax) were used in a clamp, each for a duration of 120 min. A negative correlation was found between delta PRL and MCRsubmax (r = -0.55, P < 0.02) and between delta PRL and MCRmax (r = -0.51, P < 0.03). We did not find any correlation between the prolactin response to D-fenfluramine and body weight, body mass index (BMI) or waist and hip circumference (WHR). The data support the hypothesis of a close connection between 5-HT activity in the brain and peripheral sensitivity to insulin. The possible physiological mechanisms of this connection are discussed.

Adult↗
PubMed1999

[Down's syndrome in the Czech Republic 1961-1997].

During the period from 1961-1997 the prevalence of Down's syndrome (DS) was followed up on the territory of the Czech Republic. From a consecutive series of 5,319,002 births in the CR during 1961-1997 4,933 cases of DS were diagnosed, incl. 4,410 in born infants and 523 were diagnosed prenatally and these pregnancies were terminated. The mean incidence of DS in born children during the investigation period was 7.91 per 10,000 liveborn infants. When the results of prenatal diagnosis of DS are added the mean incidence was 9.47 per 10,000 liveborn children. The prenatal diagnosis of DS in the CR was also investigated. The success rate of prenatal diagnosis of DS in the CR increased during the period from 1980-1997 to as much as 60% of detected cases. In 37.31% of all cases of Down's syndrome another inborn defect was found, most frequently inborn heart disease, defects of the central nervous system, gastrointestinal and urogenital tract. The age distribution of DS indicates a significantly increased risk for mothers already from the age of 34 years.

Czech Republic↗
PubMed1999

[Biochemical screening in the second trimester of pregnancy from a genetic aspect].

OBJECTIVE: Evaluation of the efficiency of detection of inborn chromosomal aberrations by biochemical screening of pregnant women. DESIGN: Summary of 9-years study by karyotyping of amniocytes of pregnant women, when pathological levels of AFP, hCG, uE3 were detected. Ethical problems of genetic counselling of pregnant women. SETTING: Department of Medical Genetics FTN, Chair of Medical Genetics IPVZ, Prague 4. METHODS: Biochemical screening of pregnant women in II. trimester of pregnancy by Triple Test and computer programme Prenatal Software 1.2.K, cytogenetical examination of amniocytes from amniotic fluid after amniocentesis in II. trimester. RESULTS: Among 6,471 pregnant women tested by Triple Test 20% had abnormal levels of test. In 1.5% of them an abnormal fetal karyotype was detected. Only 1/3 of them were Down Syndromes, we found also other types of aberrations. During ethically suitable counselling only 2/3 of pregnant women decided to terminate the pregnancy. CONCLUSION: Biochemical screening of pregnant women in II. trimester is very important help for detection of inborn chromosomal aberrations. The women must be informed by suitable ethical approach.

Adult↗
PubMed1998

Prolactin response to D-fenfluramine challenge test as a predictor of treatment response to haloperidol in acute schizophrenia.

D-fenfluramine has been identified as a highly selective serotonin (5-HT) releaser and re-uptake inhibitor. The objective of our study was to investigate prolactin response to D-fenfluramine challenge in non-medicated, first episode schizophrenics. We hypothesized that 5-HT reactivity can predict a response to the neuroleptic treatment. Twenty-three inpatients, 11 males and 12 females, at the Prague Psychiatric Center participated in the study. Inclusion criteria were: ICD-10 diagnosis of schizophrenia, first episode or duration of illness shorter than 36 months. D-fenfluramine challenge test was performed before 4 weeks of the haloperidol treatment. During the test, prolactin plasma levels were measured. The Brief Psychiatric Rating Scale (BPRS) was administered before and after the treatment. A statistically significant negative correlation was found between prolactin response to the D-fenfluramine challenge and improvement of psychopathology measured by the change in total BPRS score (p = 0.0004), in positive (p = 0.0403), negative (p = 0.0267), and anxiety-depression symptoms of BPRS (p = 0.0014). Our data support the original hypothesis that there is a relationship between 5-HT system activity and treatment response. The higher responsiveness of the 5-HT system in first episode, non-medicated schizophrenics, was associated with a poorer treatment response to haloperidol, an antidopaminergic neuroleptic.

Adult↗
PubMed1998

[Occurrence of diaphragmatic hernia in the Czech Republic 1961-1995].

During 1961-1995 the incidence of diaphragmatic hernia on the territory of the Czech Republic was investigated. From a consecutive series of 5,137,907 births during the period from 1961-1995 in the Czech Republic 1242 cases of diaphragmatic hernia were diagnosed, incl. 1233 in born children; 9 were diagnosed prenatally and the pregnancies were terminated. The mean incidence of diaphragmatic hernia in born children during the investigation period was 2.36 per 10,000 liveborn infants and when the prenatally diagnosed cases were added, the mean incidence was 2.39 per 10,000 liveborn infants.

Czech Republic↗
PubMed1998

[Occurrence of urinary bladder exstrophy in the Czech Republic 1961-1995].

During the period from 1961-1995 the incidence of extrophy of the urinary bladder was investigated on the territory of the Czech Republic. From a consecutive series of 5,137,907 infants born in the Czech Republic in 1961-1995 65 cases of this defect were diagnosed. The mean incidence of extrophy of the urinary bladder in born children during the investigation period was 0.14 per 10,000 liveborn. Nationwide data on the prenatal diagnosis of this defect during the investigation period are not available so far.

Bladder Exstrophy↗