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Biomedical subjects

P Weiss

Publications and source records attributed to P Weiss.

At least 73 records · Page 4Linked to original sources
PubMed1997

Programming of a movement sequence in Parkinson's disease.

The execution of multiple-component movements has been shown to be impaired in Parkinson's disease patients. To determine whether this deficit is attributed to faulty motor programming, a two-segment movement was examined by studying the kinematics of the first segment when the second segment contained variable accuracy requirements. The performance of 15 Parkinson's disease patients was compared with an age-matched control group. Movement precision not only affected the kinematics of the final segment but also the kinematics of the first segment. This 'context effect' was observed in both groups. Since Parkinson's disease patients revealed similar movement patterns to those of controls, their motor programming appears to be intact. Furthermore, correlation analysis for the segment movement-times revealed subjects with high as well as low correlation indices in both groups. The correlation indices were related to the context effect only in the Parkinson's disease patients. Independent of these phenomenon. Parkinson's disease patients showed marked hesitations between the movement segments compared with controls, suggesting that they have difficulty in implementing and/or in switching between motor program steps. Impaired force control and a reduced capacity to terminate movements in Parkinson's disease are discussed as possible explanations of the deficit in motor program implementation.

Adult↗
PubMed1997

[Contraceptive behavior in the population of the Czech Republic: results of a national survey].

Based on an anonymous survey by means of questionnaires in a representative sample of the population of the Czech Republic above the age of 15 years (862 men and 857 women) the use of different types of contraception was investigated at the onset of sexual life with a steady or casual partner, as well as attitudes to contraception. From the results ensues that during the first intercourse no contraception was used by more than half the respondents, a condom was used only by 19% men and 14% women, in particular younger men and women. In a steady partnership the most frequent method of contraception is coitus interruptus, whereby about one third have experience with hormonal contraception and two thirds of the respondents have experience with condoms. Among younger age groups of men and women there are more users of hormonal contraception and condoms. The position is similar in intercourse with casual partners. Only 5% men and 4% women oppose any contraception, almost one quarter are in favour of the so-called "natural" method and almost three quarters consider it necessary. The attitudes of atheists, younger and better educated women are more liberal.

Adolescent↗
PubMed1997

[Psychologic causes of erectile dysfunction].

The authors discuss the most frequent psychological causes of impaired erectility. The most important psychogenic factors for the development and persistence of erectile impairment is in their opinion anticipative anxiety, performance orientation, the partner's negative reaction to rare failure, the observer's attitude, antisexual upbringing, monotony of sexual intercourse, persisting sexual myths and unsuitable attitudes, impaired communication of the couple, different sexual preferences,psychic and sexual traumas and pathological mental conditions. However, as personality characteristics of the patient and the quality of his partnership may play a decisive part in the development of this disorder the authors feel that it is a mistake to confine the diagnosis and treatment only to the area of sexual reactivity and sexual behaviour.

Erectile Dysfunction↗
PubMed1997

Psychotherapy of paraphilic sex offenders.

The author provides a brief review of the current state of therapy for sex offenders in different countries and emphasizes psychotherapeutical models of treatment. He describes the course, complications and objectives of this therapy. The Czech model of specialized comprehensive treatments of paraphilic sex offenders is described. After twenty years of specialized approach in the therapy of sex offenders in the Czech Republic, the re-offense rate of 953 treated patients was 17.1%.

Cross-Cultural Comparison↗
PubMed1997

[Contraceptive behavior in the population of the Czech Republic: results of a national survey].

Using an anonymous questionnaire the authors investigated in a representative group of the Czech population above 15 years of age (862 men and 857 women) the use of the main contraceptive methods. During the first intercourse more than half the respondents did not use any contraception, a condom was used only by 19% men and 14% women. In a steady partnership the most frequent method of contraception is coitus interruptus, whereby experience with hormonal contraception was reported by cca one third and with a condom by two thirds of respondents. Among younger men and women there are more users of hormonal contraception and condoms. Only 5% of the examined men and 4% of the women opposed any type of contraception, almost one quarter of respondents use only so-called "natural methods" and almost three quarters of the respondents consider them an essential part of sex life. The attitudes of atheists and junior and more educated women are more liberal.

Adolescent↗
PubMed1996

Identification in situ and dynamics of bacteria on limnetic organic aggregates (lake snow).

Microbial assemblages on large organic aggregates (lake snow) of Lake Constance, Germany, were analyzed with rRNA-directed fluorescent oligonucleotide probes specific for the domain Bacteria and the alpha-, beta-, and gamma-subclasses of the class Proteobacteria. Lake snow aggregates were either collected in situ by SCUBA diving or in a sediment trap at 50 m or formed of natural lake water incubated in rolling cylinders under simulated in situ conditions. For the latter aggregates, the time course of the microbial colonization was also examined. The natural aggregates and those made in rolling cylinders were composed of the particulate organic material present in the lake and thus reflected the composition of the ambient plankton community. All types of lake snow aggregates examined were heavily colonized by microbial cells and harbored between 0.5 x 10(6) and > 2 x 10(6) cells aggregate -1. Between 55 and 100% of the microbial cells stained with 4', 6-diamidino-2-phenylindole (DAPI) could be visualized with the domain Bacteria-specific probe. In most samples, beta-subclass proteobacteria dominated the microbial community, constituting 27 to 42% of total cells as counted by DAPI staining, irrespective of the composition of the aggregates. During the time course experiments with the laboratory-made aggregates, the fraction of beta-subclass proteobacteria usually increased over time. Except for a few samples, alpha- and gamma-subclass proteobacteria were far less abundant than beta-subclass proteobacteria, constituting 11 to 25 and 9 to 33% of total cells, respectively. Therefore, we assume that a specific aggregate-adapted microbial community was established on the aggregates. Because the compositions of the microbial assemblages on natural and laboratory-made aggregates were similar, we conclude that aggregates made in rolling cylinders are good model system with which to examine the formation and microbial colonization of macroscopic organic aggregates.

Bacteria↗
PubMed1996

[Effect of treated genital cancer on sexual functions of the woman].

By means of a structured interview and four questionnaires (Heterosexual development of woman, Sexual activity of woman, Sexual function of woman and Questionnaire N5 which evaluates the presence and intensity of neurotic symptoms) the authors examined 163 women following treatment of a malignant tumor of the genitalia. The examination was made during balneological therapy in a spa. Their age varied between 20 and 63 years. The feeling of female inferiority was recorded roughly in every eighth proband. Deterioration of sexual function of varying extent affected every second patient. Changes in emotional relations between couples (partners) were more favourable than in sexual life. Emotional and sexual relations improvement was recorded in every fifth and eleventh woman compared with the state before the illness. Husbands or partners of the patients had great understanding and were very tolerant. In the author's opinion it is a pleasant surprise that one quarter of the patients perceived the associated stress only as medium or even small stress. A general change (deterioration) of sexual intercourse correlated directly with subjectively perceived stress. The investigation revealed also that women treated on account of malignant tumors of the genitalia on the territory of former Czechoslovakia have practically no contacts with specialists in sexual rehabilitation.

Adaptation, Psychological↗
PubMed1996

[Sex behavior of women seeking hormonal contraception and women seeking induced abortion].

Using an anonymous questionnaire, the authors assessed the sexual and contraceptive behaviour of 130 applicants for induced abortions and 330 applicants for hormonal contraception. Between the two groups these main differences were found: applicants for abortion used less frequently effective contraception and used more frequently unreliable contraceptive methods. This difference was obvious during the first intercourse as well as during later life. The use of contraception in this group is more limited also as compared with the nationwide average. In the case-history of applicants for abortion previous abortions were more frequent, as well as prostitute behaviour and the prevalence of venereal diseases. As regards heterosexual behaviour the applicants for abortion and applicants for hormonal contraception did not differ substantially. According to the authors the differences between the examined groups depend more on personality traits than sexuological characteristics.

Abortion Applicants↗
PubMed1996

Development of a fast optimization preview in radiation treatment planning.

PURPOSE: Having the capability of fast previewing an expected optimization result for a defined combination of optimization parameters is essential to reach a better optimization result. In order to achieve this goal, the well-tried Cimmino optimization algorithm requires modification. MATERIALS AND METHODS: Usually, the speed of convergence of some iterative algorithms is restricted to a bounded relaxation parameter. Exploiting the special altering behavior of the weighting factors at each step, many iteration steps are avoided by overrelaxing this relaxation parameter. Therefore, the relaxation parameter is increased as long as the optimization result is improved. This can be performed without loss of accuracy. RESULTS: Our optimization technique is demonstrated by the case of a right lung carcinoma. The solution space for this case is 36 isocentric X-ray beams evenly spaced at 10 degree. Each beam is restricted to 23 MV X-ray fields with a planning target volume matched by irregular field shapes, similar to that produced by a multileaf collimator. Four organs at risk plus the planning target volume are considered in the optimization process. The convergence behavior of the optimization algorithm is shown by overrelaxing the relaxation parameter in comparison to conventional relaxation parameter control. CONCLUSION: The new approach offers the ability to get a fast preview of the expected final result. If the clinician is in agreement with the preview, the algorithm is continued and achieves the result proven by the Cimmino optimization algorithm. In the other case, if the clinician doesn't agree with the preview, he will be able to change the optimization parameters (e.g., field entry points) and to restart the algorithm.

Algorithms↗
PubMed1995

[Diagnostic and therapeutic consequences of pulmonary artery catheters. Prospective evaluation in an intensive care unit].

BACKGROUND: The diagnostic value and the therapeutic impact of pulmonary artery catheters have been repeatedly challenged. As part of a quality assurance project we compared clinical assessment with invasive measurements of hemodynamic parameters in critically ill patients and assessed changes in therapy following catheter insertion. METHODS: In 47 consecutive patients (age 31-79 years; mean APACHE-II score 19 +/- 8) of a medical intensive care unit both physicians and intensive care nurses independently estimated mean pulmonary arterial pressure (PAPm), pulmonary capillary wedge pressure (PCWP), and cardiac output (CO) prior to pulmonary artery catheterization based on available clinical and radiological information. The physician-in-charge had to specify a presumptive treatment strategy in case hemodynamic measurements were not available. RESULTS: In 19% minor complications due to catheter insertion occurred, only one requiring intervention (intravenous adenosine). Overall, PAPm was correctly predicted in 56%, PCWP in 51% and CO in 50% of the patients (Z > 2.6; p < 0.01 for all 3 parameters). There was no statistically significant difference in the percentage of correct predictions between physicians of different training levels or between physicians and nurses. In patients with sepsis the clinical prediction of PAPm (37% correct) and of PCWP (37%) was probably not better than by chance alone (Z = 1.53; p = 0.06). In 21% there was a major change in treatment after obtaining the invasive hemodynamic values compared to the preinsertion plan. CONCLUSIONS: Although randomized trials have not yet shown pulmonary artery catheterization to decrease mortality in critically ill patients, possible useful effects on intermediate outcomes cannot be excluded in view of the high numbers of misjudgements based on clinical information alone and the considerable number of changes in therapy following catheter insertion. Reducing uncertainty in clinical judgement may not in every case lead to a beneficial strategy, but it may prevent potentially harmful decisions.

APACHE↗
PubMed1995

Serological evidence for hepatitis E virus infection in Israel.

Israel is suspected to be endemic for hepatitis E virus (HEV) because of its geographic location and the large-scale immigration from endemic countries. Although no cases of local HEV infection have been diagnosed, a serological survey would provide indirect evidence for such infection. We examined sera from 1,416 healthy subjects, including 1,139 Jews from various regions of Israel and 277 Arabs, most of whom reside in the West Bank of the Jordan River. In addition, we tested 13 non-A, non-B, and non-C viral hepatitis patients. Sera were screened for antibody to hepatitis E virus (anti-HEV) by a newly developed enzyme immunoassay (EIA) and by immunoblots for both IgG and IgM anti-HEV activity. Positive samples were confirmed by neutralization. The seroprevalence found by EIA was 2.81% and 1.81% in the Jewish and Arab populations, respectively. More than a 2-fold higher prevalence in males compared to females and an increase with age were found in both populations. However, these differences were nonsignificant. The geographical distribution was even throughout the country, except for two clusters of 3 and 4 seropositive individuals possibly reflecting past foci of infection. Eight of 37 EIA-positive sera were positive for IgG, and 3 were positive for IgM by the immunoblot assay. Among hepatitis patients (9 acute and 4 chronic), one patient with chronic hepatitis was positive for both IgG and IgM. Our study provides indirect evidence that Israel is endemic for HEV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Hepatitis E virus infection in hemophiliacs.

Israel is endemic for hepatitis E virus (HEV), the causative agent of enteric non-A, non-B hepatitis. Transmission is via the feco-oral route but the possibility of transmission through blood transfusion has been raised. This question was addressed by examining sera from 188 hemophilic patients in Israel, screening was performed with an enzyme immunoassay (EIA) for antibody against hepatitis E virus (anti-HEV) and confirmed with a neutralization test. Sixteen patients (9%) were seropositive for anti-HEV. A statistically significant difference was not found between the seroprevalence in this group and that of a healthy Israeli control population, matched for sex and age. The anti-HEV-seropositive hemophiliacs had the same seroprevalence of antibodies to hepatitis B and C virus and to HIV and the same number of cases with chronic hepatitis as among the anti-HEV-seronegative patients. The seroprevalence of antibodies to hepatitis A virus (anti-HAV) was, on the other hand, higher in the anti-HEV-seropositive group. This study indicates that HEV is not transmitted by cryoprecipitate or lyophilized factor concentrates. High prevalence of coinfection with hepatitis A supports our conclusion that HEV infection in Israeli hemophiliacs was due mainly to feco-oral transmission.

Adolescent↗
PubMed1995

Identification and characterization of antimitochondrial autoantibodies in sera of patients with monoclonal gammopathies.

Monoclonal gammopathies (MG) are defined by the accumulation of monoclonal immunoglobulins, a result of monoclonal B lymphocytes or plasma cell proliferative disorder. Only rarely do these antibodies cause an overt disease by binding to a specific autoantigen (e.g., factor VIII). In the present study, sera from 100 patients with MG were screened for the presence of antibodies against the mitochondrial pyruvate dehydrogenase complex (PDH) -- autoantibodies that are the hallmark primary biliary cirrhosis (PBC). Anti-PDH antibodies were found in 6 patients, all asymptomatic. Using ELISA and immunoblotting methods, it was found that the titre of the anti-PDH antibodies was relatively low (average OD +/- SD: 0.744 +/- 0.529; PBC patients: 1.225 +/- 0.291; P = 0.02). In each patient the autoantibodies were of both kappa and lambda chains, suggesting that they are of polyclonal origin and implying that in MG there is a significant production of polyclonal autoantibodies, in addition to monoclonal proliferation. Furthermore, in 5 of the 6 patients (83%) the anti-PDH antibodies did not recognize the E2 component of PDH (which is the major autoantigen in PBC) an did not inhibit the activity of PDH (which was inhibited by PBC autoantibodies). This is in concert with the fact that none of the patients developed liver disease and emphasizes the specificity of the anti-PDH autoantibodies associated with PBC.

Antigen-Antibody Reactions↗
PubMed1995

Monophasic luminal release of prostaglandin E2 in patients with reflux esophagitis under the impact of acid and acid/pepsin solutions. Its potential pathogenetic significance.

Normal human esophageal mucosa exhibits biphasic secretory responses to intraluminal stimuli in terms of PGE2 release with a decline under the impact of HCl and an increase in PGE2 release during mucosal exposure to HCl/Pepsin. PGE2 secretory patterns in patients with reflux esophagitis (RE) remain unknown. We have studied, therefore, luminal release of PGE2 in 28 patients with nonhealed and healed RE, and compared the obtained results with corresponding values recorded in controls. The rate of luminal release of PGE2 in nonhealed RE exhibited a monophasic patterns, i.e., significantly decreased both during mucosal exposure to HCl (2,273 +/- 444, vs. 3,655 +/- 600 pg/min, p = 0.025) and HCl/pepsin (1,271 +/- 244, vs. 3,655 +/- 600 pg/min. p = 0.003) as compared to its basal value. However, the rate of luminal PGE2 release in patients with nonhealed RE in basal conditions and during mucosal exposure to HCl was significantly higher than corresponding values in controls. Luminal release of PGE2 in patients with healed endoscopic esophagitis was significantly lower as compared to corresponding values recorded in patients with nonhealed endoscopic changes and in controls. In conclusion, (a) monophasic inhibitory responses of the esophageal mucosa to intraluminal HCl and HCl/pepsin solutions in patients with RE indicate a different pattern of mucosal secretory response to intraluminal stimuli; (b) inhibition of the rate of luminal release of PGE2 under the impact of HCl/pepsin may play a role in the development and/or progression of mucosal damage; and (c) the decline in the rate of luminal PGE2 release in healed RE indicates that its elevated value in active esophageal disease should be considered as an implication of mucosal damage induced by HCl/pepsin.

Adult↗
PubMed1995

Late diagnosis of Wilson's disease in a case without onset of symptoms.

Wilson's disease (WD) was diagnosed on the basis of a liver biopsy, blood investigations and a radio copper test in a 60-year-old, neurologically normal female with uncharacteristic gastrointestinal complaints. Since this patient never developed symptoms indicative for WD this case suggests the possibility of a subclinical course of untreated WD.

Biopsy↗
PubMed1995

Changes of carbohydrate-deficient transferrin in chronic alcoholism.

Compared with other well established liver enzyme parameters, carbohydrate-deficient transferrin (CDT) offers a new method for the identification of chronic alcoholism. The dependence of CDT and alcoholism/abstinence was studied in 29 controls and 64 alcoholics (both groups comprising men and women). In contrast to the currently used parameters GOT, GPT, gammaGT, LDH and MCV, CDT measures chronic alcoholism exclusively. CDT is dependent on sex but not age. In chronic alcoholism its rate increases significantly, but drops quickly after a short time of abstinence. CDT variations may be a specific and sensitive indicator of alcoholism or abstinence and possibly the duration.

Adult↗