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Biomedical subjects

R Ulrich

Publications and source records attributed to R Ulrich.

At least 91 records · Page 5Linked to original sources

[Occurrence of chlorinated pesticides and polychlorinated biphenyls in the stalls and outdoor environment in pig-fattening farms].

Contents of some pesticides (lindane, DDT sum, o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT, p,p'-DDT) and polychlorinated biphenyls (Delor 103, Delor 106, PCB congeners: 28, 52, 101, 118, 138, 153, 180) were investigated on three farms of fattened pigs (D., M. and T) in Hodonín district in 1994, as occurring in feed mixtures (n= 15), drinking water (n = 10), stable sedimented dust (n = 14), slurry (n = 10) and pavement dust (n = 5). Maximum permissible contents (MPC) of extraneous matters in feed mixtures were exceeded in lindane (two samples) and polychlorinated biphenyls (PCB). MPC of extraneous matters were not exceeded in drinking waters in any of the samples examined. Feed mixtures were found to have the highest average lindane content (0.054 mg/kg) and PCB sum (0.24 mg/kg); the ratio of lower chlorinated biphenyls (Delor 103) to higher chlorinated biphenyls (Delor 106) was 12:1; out of the PCB congeners, the highest amounts were determined for congeners 28 (0.067 mg/kg) and 52 (0.022 mg/kg); among the DDT isomers, isomer p,p'-DDT was prevailing (0.008 mg/kg). Drinking water had the 1:1 ratio of lower chlorinated to higher chlorinated biphenyls; out of the PCB congeners, the highest amounts were found out for congeners 28 (2.574 ng/l) and 101 (2.066 ng/l); among the DDT isomers, isomer p,p'-DDE was prevailing (1.887 ng/l). Stable dust was found to have the highest average level of DDT sum (0.026 mg/kg); the ratio of lower chlorinated to higher chlorinated biphenyls was 1:7; out of the PCB congeners, the highest amounts were determined for congeners 138 (0.036 mg/kg) and 153 (0.030 mg/kg); among the DDT isomers, isomer p,p'-DDE was prevailing (0.012 mg/kg). Slurry showed the 1:6 ratio of lower chlorinated to higher chlorinated biphenyls; out of the PCB congeners, the highest amounts were found out for congeners 138 (0.016 mg/kg dry matter) and 153 (0.014 mg/kg dry matter); among the DDT isomers, isomer p,p'-DDT was prevailing (0.005 mg/kg dry matter). Pavement dust had the 1:5 ratio of lower chlorinated to higher chlorinated biphenyls; out of the PCB congeners, the highest amounts were found out for congeners 138 (0.016 mg/kg) and 153 (0.012 mg/kg); among the DDT isomers, isomer p,p'-DDE was prevailing (0.005 mg/kg). Examination of feed mixtures and drinking waters will provide basic data on pollutant inputs to the stable environment. Stable sedimented dust is considered as an outstanding indicator of pollutant contamination of stable environment, regardless whether it comes from feed or other sources. Slurry examination will provide additional information on the total pollutant load of pig farms, informing us about outputs of extraneous matters residues from pig farms. Pavement dust examination indicates the level of pollutant load of outside stable environment as the pollutants can occasionally penetrate to the internal stable environment.

Animal Feed↗

Metamorphosis and pattern formation in Hydractinia echinata, a colonial hydroid.

There are several reasons why Hydractinia echinata Hydrozoa, Cnidaria) is excellently suited to study developmental processes. In the laboratory fertilization takes place every morning in the seawater in thousands of eggs. Cleavage starting synchronously leads to a ciliated planula larva within 2 to 3 days. Onset of metamorphosis from the larval to the polyp stage must be triggered externally. There are several agents known to induce or to interfere with induction of metamorphosis thus allowing access to the biochemical basis of this process. The pattern of the resultant polyp can be influenced by certain treatments during the process of metamorphosis allowing access to a process of proportioning. The colony develops by elongation of hollow tubes at the base of the polyps, termed stolons on which in more or less regular intervals new polyps emerge. Two (main) types of polyps are formed allowing to study spacing by lateral inhibition and lateral dependence of each other. In the present paper current data and hypotheses concerning all these topics are discussed.

Animals↗

[Occurrence of harmful pollutants in fattened pigs].

Fourteen fattened pigs (age of 240-250 days, live weight 110-120 kg) were examined on three farms (D., M. and T.) in Hodonin district in 1994 for the content of some harmful pollutants (mercury, cadmium, lead, lindane, DDT sum, DDT isomers, lower and higher chlorinated biphenyls, PCB congeners) in the muscle, liver, kidneys and subcutaneous fat. Maximum allowable quantities (MAQ) of extraneous matters were slightly exceeded in mercury only, in 5 samples of the muscle (0.012-0.022 mg/kg). In comparison with the average contents of extraneous matters in pigs in the Czech Republic in 1994, higher concentrations of mercury (0.009 mg/kg), lead (0.124 mg/kg), lindane (0.060 mg/kg fat) and DDT sum (0.083 mg/kg) were observed in the muscle of pigs from Hodonín district. The liver of the pigs contained the highest average concentrations of lead (0.141 mg/kg), lindane (0.280 mg/kg fat), DDT sum (0.323 mg/kg fat), p,p'-DDE (0.106 mg/kg fat), p,p'-DDT (0.057 mg/kg fat). PCB-Delor 103 (0.415 mg/kg fat), PCB-Delor 106 (0.561 mg/kg fat) and PCB 118 congener (0.029 mg/kg fat). The highest average values of mercury (0.014 mg/kg) and cadmium (0.147 mg/kg) were determined in the kidneys of pigs. The ratio of lower-chlorinated biphenyls (Delor 103) to higher-chlorinated biphenyls (Delor 106) was approximately 1 : 3 in the muscle, 1 : 1 in the liver and 1 : 2 in subcutaneous fat. The per cent share of three PCB congeners, 101, 138 and 153, was highest in the muscle, liver and subcutaneous fat of pigs. The pigs from Hodonín district exhibited in 1994 the greater load of mercury, lead, lindane and DDT than in other regions of the Czech Republic, but these values did not mostly exceed the hygienic limits in force. It is desirable to observe the spectrum of indicator PCB congeners for objective evaluation of PCB load in pigs, as they indicate the contamination level with lower- and higher-chlorinated biphenyls (Delor 103 to Delor 106). Greater attention should be paid to the congener PCB 118, which is the most toxic out of the indicator congeners concerned.

Adipose Tissue↗

Concentrations of polychlorinated biphenyls and chlorinated pesticides in human breast milk--a case study.

Concentrations of chlorinated pesticides (p,p'-DDE, lindane), hexachlorobenzene (HCB), sum of polychlorinated biphenyls (PCBs), and PCB congeners in breast milk during lactation and the distribution of the chlorinated compounds in fat tissue, blood serum and breast milk were pursued in five primi- or secundipara from the hinterland of a clinic of gynaecology and obstetrics in Brno in 1993. Capillary gas chromatography with ECD detection was used for the determination of the residues. The concentrations of HCB, lindane, p,p'-DDe, and sum of PCBs ranged from 42.5 to 238.4, from < 1.0 to 7.4 from 231.4 to 557.6, and from 661.3 to 2888.9 micrograms.kg-1 of milk fat, respectively. Seventeen PCB congeners were screened, of which 11 were identified in most of the milk samples (IUPAC numbers 28, 101, 118, 126, 128, 138, 153, 156, 170, 180, 194). Congeners 138, 153, 170, and 180 were the most abundant and their concentrations in microgram.kg-1 of milk fat ranged from 122.9 to 501.0 for 153, from 103.4 to 372.1 for 138, from 66.1 to 407.9 for 180, from 26.8 to 183.1 for 170, and from 10.0 to 41.7 for 118.

Adipose Tissue↗

Personal therapy: a disorder-relevant psychotherapy for schizophrenia.

While the long-term care of ambulatory schizophrenia patients requires highly effective interpersonal treatment skills among clinicians, there is little evidence to support an empirically validated individual psychotherapy of schizophrenia. Personal therapy (PT) attempts to address the apparent limitations of traditional psychotherapy by modifying the "model of the person" to accommodate an underlying pathophysiology, minimizing potential iatrogenic effects of maintenance antipsychotic medication, controlling sources of environmental provocation, and extending therapy to a time when crisis management has lessened and stabilization is better ensured. By means of graduated, internal coping strategies, PT attempts to provide a growing awareness of personal vulnerability, including the "internal cues" of affect dysregulation. The goals are to increase foresight through the accurate appraisal of emotional states, their appropriate expression, and assessment of the reciprocal response of others. The strategies are supplemented by phase-specific psychoeducation and behavior therapy techniques. Practical issues in the application of this new intervention are discussed. Preliminary observations from two samples of patients, one living with and the other living independent of family, suggest differential improvement over time among PT recipients.

Activities of Daily Living↗

New Nocardia taxon among isolates of Nocardia brasiliensis associated with invasive disease.

Nocardia brasiliensis, the second most frequently isolated aerobic actinomycete in the clinical laboratory, is usually associated with localized cutaneous infections. However, 22% of 238 N. brasiliensis isolates from the United States and 12% of 66 isolates from Queensland, Australia, which had been collected over a 17-year period, were associated with extracutaneous and/or disseminated diseases. Of the 62 invasive isolates, 37 (60%) were susceptible to ciprofloxacin and/or were susceptible to clarithromycin and resistant to minocycline, compared with only 6 (3%) of 242 localized cutaneous isolates. The 43 isolates with this susceptibility pattern appeared to define a new taxon. They were similar to Nocardia asteroides complex isolates clinically in proportions from persons with pulmonary (70%), central nervous system (23%), and/or disseminated diseases (37%) in the setting of corticosteroids (74%) or AIDS (14%). This putative new taxon differed from N. brasiliensis in the hydrolysis of adenine (92 versus 4%), beta-lactamase patterns on isoelectric focusing, and the presence of two early mycolic acid-ester peaks by high-performance liquid chromatography. Restriction analysis of a 439-bp fragment of the 65-kDa heat shock protein gene revealed that N. brasiliensis and the new taxon had different restriction patterns with 8 of the 11 enzymes tested. Screening of invasive isolates of N. brasiliensis for susceptibility to ciprofloxacin will identify most isolates of the new taxon, which likely represents a new Nocardia species.

Base Sequence↗

Mutagenicity of stable dust and drinking water on swine and cattle farms.

Single pilot examinations of mutagenicity of stable dust and drinking water were made on three swine farms (D., M., T.) and one cattle farm (N.) in the district of Hodonín in summer 1994. The mutagenicity was examined by the Ames test using the indicator strains Salmonella typhimurium TA 98 and TA 100 with (+S9) or without (-S9) metabolic activation. At the same time the contents of selected pesticides (PES) and polychlorinated biphenyls (PCB) in stable dust and drinking water and that of polycyclic aromatic hydrocarbons in stable dust were determined. Increased mutagenicity was demonstrated in drinking water (strain TA 98 with metabolic activation; index Rt/Rk 3.6-7.7) and stable dust (strain TA 100 with metabolic activation; index Rt/Rk 2.2) collected on the swine farm M. High contents of PAH (8.246 mg/kg) and PCB (0.263 mg/kg) were also found in the dust samples collected on this farm. Only drinking water showed mutagenic activity (strain TA 98 without metabolic activation; index Rt/Rk 2.6) on the swine farm D. On both the farms, the number of revertants was dose-dependent. Increased content of PAH (2.553 mg/kg) was also demonstrated on the dust samples collected on the farm D. No significant increase (twofold or higher when compared with negative controls) of mutagenic activity of stable dust or drinking water was demonstrable on the swine farm T. and the cattle farm N. Substances responsible for the mutagenicity of drinking water on the farms D. and M. have not yet been identified. Anyway, the increase of mutagenicity of stable dust and drinking water should be taken as a warning that mutagens that can jeopardise animal and human health have penetrated into the stable environment.

Animals↗

Effects of truncation on reaction time analysis.

Many reaction time (RT) researchers truncate their data sets, excluding as spurious all RTs falling outside a prespecified range. Such truncation can introduce bias because extreme but valid RTs may be excluded. This article examines biasing effects of truncation under various assumptions about the underlying distributions of valid and spurious RTs. For the mean, median, standard deviation, and skewness of RT, truncation bias is larger than some often-studied experimental effects. Truncation can also seriously distort linear relations between RT and an independent variable, additive RT patterns in factorial designs, and hazard functions, but it has little effect on statistical power. The authors report a promising maximum likelihood procedure for estimating properties of an untruncated distribution from a truncated sample and present in an appendix a set of procedures to control for truncation biases when testing hypotheses.

Bias↗

Ethnicity and psychopathology in an aging hospital-based population. A comparison of African-American and Anglo-European patients.

This study analyzes the effect of ethnicity, classified as African-American and Anglo-European, on diagnosis, symptomatology, and response to inpatient treatment in a sample of geriatric patients of a research unit of a tertiary care facility. Variables that might confound the effects of ethnicity, such as age, gender, education, and associated diagnoses, were statistically controlled. Psychotic diagnoses were significantly associated with ethnicity, being higher in African-Americans, weakening the claim that such an association stems from the confounding effects of social class. Variability in the ratings on the Brief Psychiatric Rating Scale and Hamilton Depression Scale was significantly associated with ethnicity in several instances. African-Americans appeared to obtain comparatively higher therapeutic benefits from hospitalization. Results are discussed using knowledge of the field of cultural and social psychiatry.

Black or African American↗

Gender differences in how medical students learn to rate psychopathology.

The aim of this study was to examine factors influencing medical students' learning of psychopathology assessments during the psychiatric clerkship. The subjects included 122 third-year medical students participating in a 6-week psychiatric clerkship. They completed Brief Psychiatric Rating Scale ratings on short, focused interviews in a balanced design before and at the end of the clerkship. Deviation of their ratings from standard ratings by experienced psychiatrists constituted the dependent variables. Female medical students showed a clear significant improvement during the clerkship, whereas male students tended to experience a significant reduction in their accuracy. We conclude that there may be gender-related differences in these medical students' ability to assimilate and cope with the clinical experience of the psychiatric clerkship. The implications of these findings for psychiatry training are discussed.

Attitude↗

The lateralized readiness potential preceding brief isometric force pulses of different peak force and rate of force production.

Previous studies have reported that the lateralization of the readiness potential is unaffected by force amplitude of brief unimanual responses. However, because those studies did not specify rate of force production, response force probably was mainly controlled by force unit duration rather than by recruitment of force units, which may explain this negative finding. To enforce recruitment control, we factorially combined peak force (10% or 50% of maximal voluntary finger force) and time to peak force (100 or 200 ms). A precue provided advance information about the responding index finger (left vs. right). After 1 s, the imperative stimulus followed, requiring a brisk isometric flexion of the specified index finger. Symmetric effects, maximal at the vertex, of both force and rate of force production were observed 200-100 ms before the imperative stimulus in stimulus-synchronized averages and 200-100 ms before response onset in response-synchronized averages. However, neither force nor rate of force production affected the lateralized readiness potential. We conclude that this measure does not reflect movement parameters but appears to indicate an abstract preparation of lateralized response channels.

Adult↗

Risk factors for suicidal behavior in borderline personality disorder.

OBJECTIVE: This study identified potential risk factors for suicidal behavior in patients with borderline personality disorder defined by the Diagnostic Interview for Borderline Patients and by DSM-III-R criteria for patients who did and did not attempt suicide. METHOD: Histories of suicide attempts and attempt characteristics were obtained by Schedule for Affective Disorders and Schizophrenia interviews from 84 patients with borderline personality disorder and were related to severity of borderline pathology, diagnostic comorbidity, and state and trait symptoms. RESULTS: There were 61 patients with a lifetime history of suicide attempts (72.6%), with an average of 3.39 (SD = 2.87) attempts per patient. Attempters were significantly older than nonattempters, with more impulse actions, antisocial personality disorder comorbidity, and state depression. State depression was significantly less severe in patients who had attempted suicide in the present episode (or past year) than in patients who had attempted suicide only in the past. A comorbid diagnosis of major depression, alcoholism, or drug use disorder did not distinguish attempters from nonattempters. Suicide attempt in the present episode was best predicted by the number of prior lifetime attempts. A highly serious intent to commit suicide was predicted by the number of lifetime attempts and subjective depression, while a low intent was predicted by a mixed subtype of borderline personality disorder plus schizotypal personality disorder and paranoid ideation. A high degree of medical lethality was predicted by number of lifetime attempts, older age, and hysteroid dysphoria, while low lethality attempts were associated with high degrees of anger. CONCLUSIONS: Risk factors for suicidal behavior in patients with borderline personality disorder include older age, prior suicide attempts, antisocial personality, impulsive actions, and depressive moods but not comorbid affective disorder, alcoholism, or drug use disorders.

Adult↗

Fine mapping of HIV-1 Nef-epitopes by monoclonal antibodies.

A panel of newly isolated murine monoclonal antibodies is described which are specific for the Nef protein of the human immunodeficiency virus type 1 (HIV-1). Epitope mapping using recombinant Nef-related proteins, synthetic peptides and lipopeptides showed 3 independent antigenic determinants located within the regions of amino acids 83-93, 175-190 and 86-166 of the Nef protein. None of the monoclonal antibodies reacted with recombinant Nef proteins of HIV-2.

Amino Acid Sequence↗

Subcloning of HIV-2 nef genes in E. coli and immunological reactivity of expressed fusion proteins.

The nef gene located in the 3' region of the HIV-2 genome encodes an N-terminally myristylated protein of 27-35 kD, likely to be involved in the regulation of viral transcription. The nef genes of HIV-2 isolates GH-1, ROD, ST, BEN, and D194.17 were inserted into E. coli pEX vectors and expression of Nef beta-galactosidase fusion proteins was detected in stained gels. All fusion proteins specifically reacted with a rabbit serum raised against bacterially expressed Nef from HIV-2D194.17. Sera from monkeys inoculated with HIV-2BEN or SIVMAC251 recognized the Nef proteins of only certain HIV-2 isolates. No cross-reactivity of these sera with HIV-1 Nef and of a rabbit anti-HIV-1-Nef serum with the described HIV-2 Nef fusion proteins was observed.

Animals↗

Motor coactivation revealed by response force in divided and focused attention.

Four experiments examined effects of bimodal stimulation on response force (RF) in addition to reaction time (RT). In a divided-attention task (Experiments 1 to 3), subjects were asked for a speeded response to either a visual or an auditory signal. In unimodal signal trials, either a visual or an auditory signal was presented alone, and in redundant-signals trials, both signals were presented simultaneously. The same stimulus arrangement was used in a focused-attention task (Experiment 4), but subjects had to withhold their response when an auditory signal was presented alone. In all experiments, the fastest RTs were attained in redundant-signals trials. In addition, RF was largest in redundant-signals trials, especially in the divided-attention task, suggesting a motor coactivation hypothesis. The results indicate that the type of stimulation influences not only when a response is initiated but also how the response is executed. This finding challenges the view, commonly held in mental chronometry, that late motoric processes remain untouched by experimental manipulations. A detailed analysis of the relationship between RT and RF revealed that these variables are not inherently redundant measures, and, therefore, RF recording may supplement the traditional RT measurement in mental chronometry.

Acoustic Stimulation↗

Do Caucasian and black adolescents differ at psychiatric intake?

A large sample of adolescents brought for psychiatric evaluation to a public University based facility are the subjects of the study. Material incorporated in a DSM-III multiaxial formulation plus symptoms constituted the dependent variables. Analyses concentrated on ethnic differences, with variation associated with gender and social class controlled statistically. Caucasians showed comparatively greater clinical morbidity: higher number of Axis I definite diagnoses and level of symptoms. Eating disorder diagnoses were more common in Caucasians. There were no significant differences pertaining to level of stress or social impairment. Blacks showed higher levels of symptoms scored as "social aggression" and diagnosed as conduct disorders. The pattern of results raised the question of a possible referral bias, with blacks shunted to the psychiatric facility with lower levels of standard clinical psychopathology, but higher levels of social oppositional behavior. Further research is needed to verify if such a bias does exist.

Adolescent↗