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Biomedical subjects

L Bauer

Publications and source records attributed to L Bauer.

At least 37 records · Page 2Linked to original sources
PubMed1997

Respiratory sinus arrhythmia in children with severe cyanotic breath-holding spells.

In this study we sought to investigate parasympathetic activity among children with severe cyanotic breath-holding spells by examining respiratory sinus arrhythmia. The study sample was composed of two groups of patients, 16 subjects with cyanotic breath-holding spells (5 male, 11 female; mean age, 37.5 mo) and 17 controls (8 male, 9 female; mean age, 37.7 mo). Each subject's electrocardiogram was recorded in a quiet room and digitized by an 80386 personal computer during five 1-minute periods. R-R intervals within each 1-minute period were converted to heart rate in 120 successive 0.5 second intervals. The resultant heart rate time series was converted to its underlying frequency composition by a fast Fourier transform and averaged across minutes. Respiratory sinus arrhythmia was defined as the variability in the time series over a frequency range (0.096-0.48 Hz) corresponding to a range of respiratory rates from 6 to 30 breaths per minute. Analysis revealed after ANCOVA adjustment for age and gender with subject group and frequency bin as dependent measures, that subjects with cyanotic breath-holding spells had similar variability in their heart rates as did controls (group x frequency bin: F = 0.74, P = 0.71). This study supports the hypothesis that autonomic dysregulation in cyanotic breath-holding spells is not due to a primary disturbance in central parasympathetic control over cardiac rate and rhythm.

Analysis of Variance↗
PubMed1996

Antisocial personality disorder, childhood delinquency, and frontal brain functioning: EEG and neuropsychological findings.

This experiment examined the ability of EEG activity and neuropsychological testing to predict both antisocial personality disorder (ASP) and retrospective self-ratings of early childhood problem behaviors (CPB). Regression analyses found that increased frontal left-hemisphere EEG activation was associated with a decreased likelihood of the diagnosis of ASP or CPB. An association was also found between several motor tests of the Luria-Nebraska and Porteus Maze Test scores and CPB/ASP. The current findings suggest that ASP and CPB are associated with variations in frontal lobe functioning. They further suggest that disturbances in prefrontal functioning may be a common biological ground that links ASP, substance abuse, and biological mechanisms of reinforcement.

Adult↗
PubMed1996

Food allergy to honey: pollen or bee products? Characterization of allergenic proteins in honey by means of immunoblotting.

OBJECTIVE: To characterize the allergenic components of honey, 23 patients allergic to honey were investigated. All displayed allergic symptoms after ingestion of honey or honey-containing products, ranging from itching in the oral mucosa to severe systemic symptoms to anaphylactic shock. METHODS AND RESULTS: Immunoblot analyses of the patients' sera revealed IgE binding to proteins at a molecular mass of 54 kd, 60 kd, 72 kd, or to a 30 kd/33 kd double band, or to both in sunflower honey extracts. The three bands corresponding to higher molecular mass proteins could also be detected in the three other kinds of honey (locust tree, European chestnut and forest honey) that were tested and represented bee products because IgE binding to these proteins was inhibited by extracts of honeybee heads and extracts of isolated bee venom sacs. The 30 kd/33 kd bands could be identified as sunflower honey-specific. When testing sera from patients allergic to bee venom with honey extracts, in seven of 10 cases IgE binding to bee-specific components could be observed. CONCLUSION: Both proteins derived from secretions of pharyngeal and salivary glands of honeybee heads and pollen proteins contained in the honey cause allergic reactions to honey.

Adolescent↗
PubMed1996

IgE cross-reactivity between birch pollen, mugwort pollen and celery is due to at least three distinct cross-reacting allergens: immunoblot investigation of the birch-mugwort-celery syndrome.

BACKGROUND: Allergy to celery is often associated with sensitization to birch and/or mugwort pollen. OBJECTIVE AND METHODS: In a multi-centre study, sera from 23 patients suffering from type 1 allergy to celery and 15 patients with positive celery RAST but no clinical sensitization were compared. To examine whether cross-reactivity between celery and mugwort pollen includes cross-sensitization to birch pollen allergens, we determined cross-reacting structures in birch pollen, mugwort pollen and celery by means of immunoblotting. Inhibition studies were performed by preincubation of sera with extracts of birch pollen, mugwort pollen, and celery. RESULTS: We identified three groups of proteins--homologues of Bet v 1 and birch profilin (Bet v 2) as well as a group of proteins with a molecular range of 46 to 60 kD--displaying IgE-cross-reactivity, which were shared by birch pollen and celery. Two of these groups of allergens (profilin and the 46 to 60 kD proteins) were also present in mugwort pollen. In this paper we demonstrate that most cross-reacting allergens present in mugwort pollen and celery can also be detected in birch pollen extract. CONCLUSION: Therefore we propose, from a serological point of view, to extend the mugwort-celery syndrome to the birch-mugwort-celery syndrome.

Allergens↗
PubMed1996

Respiratory sinus arrhythmia in patients with Prader-Willi syndrome.

In this investigation, we sought to further test the hypothesis that parasympathetic deficiency exists among persons with Prader-Willi syndrome, by examining respiratory sinus arrhythmia. The study sample comprised two groups of patients: 14 subjects with Prader-Willi syndrome and 14 age- and sex-matched controls. Each subject's electrocardiogram was recorded in a quiet room and digitized by a personal computer during five 1-minute periods. RR intervals within each 1-minute period were converted to heart rate in 120 successive 0.5-second intervals. The resultant heart rate time series was converted to its underlying frequency composition by a fast Fourier transform and averaged across minutes. Respiratory sinus arrhythmia was defined as the variability in the time series over a frequency range (0.096 to 0.48 Hz) corresponding to a range of respiratory rates from six to 30 breaths/minute. Analysis revealed significantly less variability in the heart rates of subjects with Prader-Willi syndrome relative to age- and sex-matched controls (group x frequency bin: F = 2.26, P < .05). An analysis of covariance adjusting for body mass index differences between the groups produced identical results. These findings support the existence of a parasympathetic deficiency among subjects with Prader-Willi syndrome independent of their body mass. This is likely due to dysregulation of the central autonomic network.

Adolescent↗
PubMed1995

Multi-center N400 ERP consistency using a primed and unprimed word paradigm.

A word priming paradigm involving primed, unprimed, and non-word experimental conditions was used to elicit event-related potentials (ERPs) in normal, young adult males in identically equipped electrophysiology laboratories located in 6 different cities in the USA. Analyses of the average amplitude of a specified latency window containing the N400, the N400 peak amplitude, or the latency of the N400 peak amplitude found no differences among laboratory locations. The shape of the N400 ERP wave form was also found to be highly correlated across laboratory sites for each experimental condition. Comparison of the data with analogous word priming paradigms revealed similar patterns for the N400 components and response times in both the primed and unprimed experimental conditions. These findings suggest that the data from all 6 laboratory locations are consistent with each other and are congruous with those found in other N400 studies and will permit pooling of subject data for future research.

Adolescent↗
PubMed1995

Identification of allergens in fruits and vegetables: IgE cross-reactivities with the important birch pollen allergens Bet v 1 and Bet v 2 (birch profilin).

BACKGROUND: In this study serum samples collected from 20 patients with birch pollen allergy were investigated. All patients had experienced allergic symptoms after contact with or ingestion of particular fresh fruits and vegetables known as birch pollen-related foods. METHODS: Serum samples were tested by means of immunoblotting for IgE reactivities with proteins in extracts of birch pollen, apple, pear, celery, carrot, and potato. Anti-Bet v 1 and anti-Bet v 2 antibodies were used to investigate cross-reactivity. Inhibition studies were performed by preincubation of sera with recombinant Bet v 1 and Bet v 2. RESULTS: IgE binding to proteins, corresponding to the major birch pollen allergen Bet v 1 and to Bet v 2 (birch pollen profilin) could be observed. An allergen homologous to Bet v 1 could be detected in apple, pear, and celery when a Bet v 1-specific monoclonal antibody was used. Testing a polyclonal rabbit anti-Bet v 2 antibody with extracts of the respective plants revealed the presence of profilins in every source tested. Inhibition with recombinant Bet v 1 and Bet v 2 led to complete blocking or marked reduction of IgE binding to proteins of comparable molecular weights in the respective food extracts, indicating IgE cross-reactivity. CONCLUSION: Our results indicate that many plant-derived food agents contain proteins with high homology to the birch pollen allergens Bet v 1 and Bet v 2 and must therefore be considered as potentially threatening for patients with tree pollen allergy.

Allergens↗
PubMed1995

Anterior brain dysfunctioning as a risk factor in alcoholic behaviors.

This study assessed the relationship between neuropsychological and electrophysiological functioning and four alcohol-related measures: the Michigan Alcoholism Screening Test (MAST), the age at which the first drink was taken, frequency of drinking to "get high", and frequency of drinking to "get drunk". Ninety-one young adult men with no history of alcohol dependence were recruited. Subjects completed a variety of alcohol-related scales and a battery of neuropsychological tests. Resting EEG activity was also recorded. Stepwise regression analysis found that neuropsychological tests commonly regarded as measuring frontal and/or temporal neocortex functioning predicted the age at which subjects took their first drink and their scores on the MAST. Tests of frontal functioning, along with tests of memory, also predicted the frequency with which subjects reported drinking to "get drunk". Tests of memory also predicted the frequency at which subjects drank to "get high". On two of the alcohol measures, including age at which the first drink was taken and frequency of drinking to "get high", left-frontal slow alpha EEG activity was a significant predictor. These results suggest that markers of anterior brain functioning/dysfunctioning are associated with self-reports of alcohol-related behaviors, and that disturbances in the integrity of the anterior neocortex may be a risk factor in the development of alcohol-related behaviors.

Adult↗
PubMed1995

Relationship between alcohol-related expectancies and anterior brain functioning in young men at risk for developing alcoholism.

This experiment examined the relationship between anterior brain functioning and alcohol-related expectancies. Ninety-one young men at risk for developing alcoholism were assessed on the Alcohol Expectancy Questionnaire (AEQ) and administered neuropsychological and EEG tests. Three of the scales on the AEQ, including the "Enhanced Sexual Functioning" scale, the "Increased Social Assertiveness" scale, and items from the "Global/Positive Change scale," were used, because each of these scales has been found to discriminate alcohol-based expectancies adequately by at least two separate sets of investigators. Regression analysis found that anterior neuropsychological tests (including the Wisconsin Card Sorting test, the Porteus Maze test, the Controlled Oral Word Fluency test, and the Luria-Nebraska motor functioning tests) were predictive of the AEQ scale scores on regression analysis. One of the AEQ scales, "Enhanced Sexual Functioning," was also predicted by WAIS-R-Verbal scales, whereas the "Global/Positive" AEQ scale was predicted by the WAIS-R Performance scales. Regression analysis using EEG power as predictors found that left versus right hemisphere "difference" scores obtained from frontal EEG leads were predictive of the three AEQ scales. Conversely, parietal EEG power did not significantly predict any of the expectancy scales. It is concluded that anterior brain any of the expectancy scales. It is concluded that anterior brain functioning is associated with alcohol-related expectancies. These findings suggest that alcohol-related expectancy may be, in part, biologically determined by frontal/prefrontal systems, and that dysfunctioning in these systems may serve as a risk factor for the development of alcohol-related behaviors.

Adult↗
PubMed1994

P300 differences between non-alcoholic young men at average and above-average risk for alcoholism: effects of distraction and task modality.

1. P300 event-related electroencephalographic potentials were recorded from 79 young adult males, cross-classified with respect to the presence/absence of a family history of alcoholism (FHA) and the presence/absence of a personal history of antisocial personality (ASP) disorder. P300s were elicited using visual and auditory oddball tasks. Each oddball task was repeated with a tracking task added as a distractor. 2. In general, distraction increased the latencies and reduced the amplitudes of P300s elicited by the oddball stimuli. The P300 latency increase occurred only in low risk ASP- and FHA- groups. There was no adaptive increase in P300 latency in the higher risk ASP+ and FHA+ groups. 3. Group differences in P300 were restricted to visual tasks. No interpretable group differences in P300 latency or amplitude were found during the auditory tasks.

Acoustic Stimulation↗
PubMed1994

Reduced P3 amplitudes are associated with both a family history of alcoholism and antisocial personality disorder.

1. Previous research has demonstrated that the amplitude of the P3 component of the event-related electroencephalographic potential (ERP) is influenced by the presence/absence of a family history of alcoholism (FHA). The present study extended this line of research by examining the P3 effects of both FHA and antisocial personality disorder (ASP) in a 2 x 2 factorial design. 2. The task required subjects to judge the orientation of an infrequently-occurring outline drawing, representing an aerial view of a human head. 3. Analyses of P3 amplitudes elicited by this drawing revealed reductions attributable to the effects of both FHA and ASP, but not their interaction. These effects were most apparent at frontal electrode sites. Analyses of P3 latency revealed no consistent pattern of findings. However, the interval between P3 and manual reaction time was shorter in the ASP+ group relative to the ASP-group.

Adult↗
PubMed1994

School performance at nine years of age in very premature and very low birth weight infants: perinatal risk factors and predictors at five years of age. Collaborative Project on Preterm and Small for Gestational Age (POPS) Infants in The Netherlands.

To assess the impact of both perinatal disorders and developmental problems identified at preschool age on school performance, we followed a virtually complete birth cohort of very premature (< 32 completed weeks of gestation) and very low birth weight infants until they were 9 years of age. In 84% of the survivors (n = 813), data on school performance were available for analysis. At the age of 9 years, 19% of the children were in special education. Of the children in mainstream education, 32% were in a grade below the appropriate level for age and 38% had special assistance. After correction for other perinatal items, children of low socioeconomic status and boys had significantly higher adjusted odds ratios for special education. Logistic regression with a perinatal and a 5-year time category showed that the most predictive factors for special education were developmental delay, neuromotor and speech/language function, inattention and hyperactivity score, total problem score, and reported school results at the age of 5 years. When children with disabilities were left out of the analysis, the importance of neuromotor function and total problem score disappeared. Increased risks of any school failure in nondisabled children included mild or severe developmental delay and marginal or poor school performance at the age of 5 years. Long-term follow-up with specific attention to these predictors at 5 years of age, although time-consuming, is necessary.

Birth Weight↗
PubMed1993

Phase I trial of recombinant granulocyte-macrophage colony-stimulating factor in patients with lung cancer: clinical and immunologic effects.

Recombinant granulocyte-macrophage colony-stimulating factor (rhuGM-CSF) may enhance the functional activity of monocytes and macrophages in vitro and in vivo and thereby have antitumor activity. A phase I trial using rhuGM-CSF was performed; the trial included 17 patients with unresectable and/or metastatic lung cancer. rhuGM-CSF was administered as a continuous infusion for 14 days at four dose levels: 60 micrograms/m2, 125 micrograms/m2, 250 micrograms/m2, and 500 micrograms/m2. Dose-limiting toxicity was pulmonary and occurred at 500 micrograms/m2, with the maximal tolerated dose (MTD) identified as 250 micrograms/m2. The hematologic effects of rhuGM-CSF included leukocytosis with significant correlations between dose level and the numbers of neutrophils, monocytes, eosinophils, and lymphocytes. Bronchoalveolar lavage was performed for 14 patients, and no effect on alveolar macrophage numbers was detected. Tumor biopsies were obtained in two patients, and no changes in macrophage infiltrates were detected with use of immunohistochemical studies. Serum levels of GM-CSF reached a steady state during week one and decreased or were undetectable during week two. No evidence of tumor regression was seen. rhuGM-CSF when administered as a continuous infusion was well tolerated and appears to modulate monocyte numbers and function in vivo.

Adult↗
PubMed1993

Phase II trial of doxorubicin and trifluoperazine in metastatic breast cancer.

Pre-clinical and clinical studies have shown that trifluoperazine (TFP) can modulate multidrug resistance. We have performed a Phase II trial of TFP and doxorubicin in doxorubicin-naive patients with metastatic breast cancer. We hypothesized that TFP would inhibit the development of doxorubicin resistance, resulting in an increased rate of complete response or a prolongation in response duration. Twenty patients with metastatic breast cancer were treated every 3 weeks with TFP 5 mg by mouth every 6 hours on days 0-5 and doxorubicin 60 mg/m2/96 hr on days 1-4 by continuous intravenous infusion. The first 5 patients were treated with TFP 15 mg by mouth every 6 hours, but the dose was reduced to 5 mg every 6 hours when grade 3-4 extrapyramidal toxicity was noted in 3 of the first 5 patients. Thereafter, neurologic toxicity was grade 0-2. No complete and 9 partial responses were produced in 20 patients (45%). The median response duration was 17 weeks (range 7-112). The combination of trifluoperazine and doxorubicin did not seem to produce a response rate or duration markedly different than that expected for doxorubicin alone in patients with metastatic breast cancer. Alternative trial designs may be necessary in future clinical trials investigating the inhibition of acquisition of drug resistance.

Adult↗
PubMed1993

Phase I study of WR-2721 and carboplatin.

Because WR-2721 reduces the toxicity of cisplatin and carboplatin in preclinical systems, we have treated 35 patients in a phase I study of WR-2721 and carboplatin. As the plasma half-life of WR-2721 is short relative to that of carboplatin, WR-2721 was administered in two divided doses. This schedule produced acceptable toxicity in 24 patients treated with carboplatin 400 mg/m2 and escalating doses of WR-2721. In the subsequent 11 patients, WR-2721 was fixed at 740 mg/m2/dose and the dose of carboplatin was escalated. With WR-2721, grade 3-4 thrombopenia (platelets < 50 x 10(9)/l) was produced in 4/5 patients treated with carboplatin 625 mg/m2 and in 1/6 patients treated with carboplatin 500 mg/m2. Carboplatin pharmacokinetic parameters in 4 patients were similar to those reported for carboplatin alone. These results suggest that WR-2721 might increase the maximum tolerated dose of carboplatin from 400 to 500 mg/m2.

Adult↗
PubMed1993

Reduced P300 amplitude in relation to family history of alcoholism and antisocial personality disorder among young men at risk for alcoholism.

Both a family history of alcoholism (FH+) and a personal history of Antisocial Personality Disorder (ASP) increase the risk for developing alcoholism, particularly among males. Previous studies suggest that a reduced P300 event-related potential (ERP) amplitude is a marker of the presence of a family history of alcoholism. The present study examined the effects of both a FH+ and a personal history of ASP in relation to the P300 amplitude in a sample of 79 nonalcoholic young men. Reduced P300 ERP amplitudes elicited by a visual oddball task were found at the frontal electrode sites for both the FH+ and ASP groups, but not their interaction. There were no group differences in P300 latencies. P300 amplitude at Pz was associated with behavioral measures of figural memory, while P300 at F8 was associated with behavioral measures of cognitive flexibility.

Adult↗