Biomedical subjects

J Beer

Publications and source records attributed to J Beer.

At least 19 recordsLinked to original sources

PubMed2000

Functional imaging of brain areas involved in the processing of coherent and incoherent wide field-of-view visual motion.

The brain areas involved in processing wide field-of-view (FOV) coherent and incoherent visual stimuli were studied using positron emission tomography (PET). The brains of nine subjects were scanned as they viewed texture patterns moving in the roll plane. Five visual conditions were used: (1) coherent clockwise (CW) wide-FOV (>100 degrees) roll motion; (2) coherent counter-clockwise (CCW) wide-FOV roll motion; (3) wide-FOV incoherent motion; (4) CCW motion confined to the central visual field (approximately 55 degrees); and (5) a stationary control texture. The region most activated by the coherent-motion stimulus relative to the static one was the medial-occipital cortex, whereas both the medial- and lateral-occipital cortices were activated by incoherent motion relative to a static texture. Portions of the retroinsular parietal-temporal cortex, superior insula, putamen, and vestibulocerebellum responded specifically to the coherence of the stimulus, whereas a widespread lateralized activation was observed upon subtracting the CW scans from the CCW scans. The results indicate separate neural regions for processing wide-FOV motion versus stimulus coherence.

Adult↗

PubMed2000

Child characteristics which impact accuracy of recall and suggestibility in preschoolers: is age the best predictor?

OBJECTIVE: The purpose of the present study was to determine whether individual difference factors of metamemory, intelligence, and temperament can improve the ability to predict accuracy of recall and suggestibility in preschoolers. METHOD: Fifty-six children ranging in age from 43 months to 83 months (M = 61, SD = 9) were recruited from 13 child care centers in a rural southeastern town. Children participated in a "Circus Day" event conducted by two female undergraduate psychology students dressed as clowns. Approximately 10 days (M = 10; SD = 2) after the event, children were interviewed regarding their experiences. RESULTS AND CONCLUSIONS: Bivariate correlations and multiple regression analyses were performed in order to determine which factors were related and unique contributors to accuracy of recall and suggestibility. Of principal importance is the finding that child characteristics such as metamemory ability, intellectual functioning, and temperament may indeed be helpful in determining a child's capacity to accurately recall information in an interview, although for the most part age is the best predictor. Findings also underscore the importance of considering a child's SES and race when planning and conducting interviews with young children. Possible explanations for these findings as well as implications for future research and clinical application are discussed.

Child↗

PubMed2000

Comparison of Mycobacterium tuberculosis susceptibility testing performed with BACTEC 460TB (Becton Dickinson) and MB/BacT (Organon Teknika) systems.

The recently introduced automated culture systems MB/BacT (Organon Teknika, Belgium) was compared with radiometric BACTEC 460TB (Becton Dickinson, USA) to test antimicrobial susceptibility of Mycobacterium tuberculosis to first line drugs. On 113 strains 97.5% agreement was obtained, with the difference being not significant. Concordance was practically complete for the most important drugs, isoniazid and rifampin. The two methods however significantly differed for the time needed to complete the test; in fact MB/BacT required on the average five days more than BACTEC 460TB. Despite the delay in the completion of the test, the excellent reliability along with the elimination of radioactivity and full automation make MB/BacT an attractive alternative for susceptibility testing of M. tuberculosis.

Antibiotics, Antitubercular↗

PubMed1998

Expression of c-jun, junB, c-fos, fra-1 and fra-2 mRNA in the rat brain following seizure activity and axotomy.

The present study has investigated the congruence of mRNA induction and protein expression of inducible transcription factors (ITFs). The patterns of c-jun, junB, c-fos, fra-1 and fra-2 mRNAs were studied by radioactive and non-radioactive in situ hybridization in the adult rat brain following kainate-induced seizure activity and axotomy. In the same animals, the expression of c-Jun, JunB and c-Fos proteins was compared with the respective mRNA signals. Using radioactive labeled probes all investigated mRNAs showed an onset within 1 h after systemic kainate application and the maximal levels were generally reached after 3 h. Each mRNA displayed a specific temporo-spatial expression pattern. Whereas fra-1 and fra-2 were restricted to the hippocampus, c-jun, junB and c-fos were additionally induced in the cortex, amygdala and thalamus. The areas with maximal labeling were the dentate gyrus and the hippocampal CA1 and CA3 subfields. The expression patterns between c-jun, junB and c-fos mRNA were virtually congruent with the respective protein. Labeling of the junB and fra-2 probes with digoxigenin yielded similar results. Twenty-four hours, 3 and 10 days following transection of the medial forebrain bundle and the mamillo-thalamic tract, high levels of c-jun mRNA (either digoxigenin or radioactive labeled probes) and protein were seen in the axotomized neurons of the substantia nigra pars compacta and mamillary body whereas the other mRNAs studied and the JunB or c-Fos proteins could not be detected. These findings demonstrate that mRNAs encoding for ITFs are translated into the respective proteins following excitotoxic seizures and axotomy, and that the antisera used for immunocytochemistry yield specific expression patterns of homologous proteins.

Animals↗

PubMed1998

Geomagnetic modulation of the 36Cl flux in the GRIP ice core, greenland

Geomagnetic field strength is expected to affect the production rate of cosmogenic isotopes such as beryllium-10, carbon-14, or chlorine-36. Chlorine-36 data from the Greenland Ice Core Project (GRIP) ice core agree well with a production rate calculation based on a paleomagnetic reconstruction for the past 100,000 years over both long- and short-term variations. A chlorine-36 peak at 38,000 years ago previously found in the beryllium-10 record from the Vostok ice core can be explained by a period of low geomagnetic field intensity.

Journal Article↗

PubMed1997

Brain-derived neurotrophic factor modulates GAP-43 but not T alpha1 expression in injured retinal ganglion cells of adult rats.

The administration of neurotrophins affects neuronal survival and growth, but less is known about their ability to modify the expression of growth associated genes following injury to CNS neurons. Here we characterize the effect of brain-derived neurotrophic factor (BDNF) on mRNA levels for T alpha1 alpha-tubulin, and for GAP-43, two genes whose expression levels in retinal ganglion cells (RGC) tend to correlate with growth. We first determined that most adult rat RGCs can retrogradely transport BDNF by injecting 125I-BDNF into RGC target sites in vivo. We then used quantitative in situ hybridization to characterize the effect of axotomy, or axotomy and BDNF administration on mRNA levels for GAP-43 and T alpha1. Axotomy alone resulted in a general decrease in T alpha1 alpha-tubulin mRNA levels by 2 weeks, and elicited an increase in GAP-43 mRNA levels in an average of 30% of surviving RGCs. The intravitreal administration of a single dose of BDNF (5 microg) to axotomized RGCs on the day of injury did not affect T alpha1 alpha-tubulin mRNA levels, but was followed by a moderate (approximately 80%), and short-lasting enhancement of GAP-43 mRNA levels in most RGCs during the first week after axotomy. No significant increase in GAP-43 mRNA levels was observed when BDNF was injected into the uninjured eye. We conclude that BDNF specifically enhances GAP-43 but not T alpha1 mRNA levels in injured RGCs. Because BDNF is known to stimulate branch length of injured RGCs, we suggest that changes in the expression of GAP-43, but not T alpha1 tubulin, correlate with branching of injured neurons as opposed to long distance regrowth.

Animals↗

PubMed1997

Reduced calcium dialysate in CAPD patients: efficacy and limitations.

BACKGROUND: The increasing use of 'reduced calcium' dialysate in CAPD patients treated with calcium-based phosphate binders has raised concerns that this could lead to negative calcium balance, worsening hyperparathyroidism, and osteopenia. METHODS: The present study was conducted to examine the possibilities (a) that 1.25 mM calcium dialysate leads to negative calcium balance and worsening hyperparathyroidism, and (b) that conversely 1.25 mM calcium dialysate is still too high for some patients. We studied 22 patients who, after a 2-month run in using 1.75 mM calcium dialysate and aluminium hydroxide binders, entered a 3-month phase of 1.25 mM calcium dialysate with continuation of aluminium hydroxide as the sole phosphate binder. The patients then entered a final 9-month phase in which dialysate calcium remained at 1.25 mM and calcium carbonate was substituted for aluminium hydroxide and progressively titrated to achieve optimum phosphate control. RESULTS: During the initial 3-month period, parathyroid hormone increased from 259, range 11-1149 to 405, range 16-1318 pg/ml (P = 0.0001) and ionized calcium decreased from 1.17 +/- 0.06 to 1.11 +/- 0.08 mM (P = 0.0004). The subsequent 9-month phase was associated with return of parathyroid hormone to baseline levels. Further dialysate calcium reduction to 0.6 mM was implemented in the four patients who became hypercalcaemic. CONCLUSION: This study has clearly shown that reduction of dialysate calcium to 1.25 mM can be harmful to CAPD patients if oral calcium availability is inadequate. It has also shown that dialysate calcium at 1.25 mM is a compromise, with increased risk of hyperparathyroidism if calcium intake is too low and, conversely, risk of hypercalcaemia and unacceptable increases of the Ca x Pi product in a minority of patients. At these extremes there is a need for a high-calcium dialysate (1.75 mM) and a very low-calcium dialysate (0.6 mM or less), to optimize management.

Adult↗

PubMed1996

Low-dose thrombolysis for thrombosed prosthetic heart valve.

This report describes two cases of successful fibrinolysis of thrombosed tricuspid and mitral valve prostheses (Carbomedics; Austin, Texas) with low-dose urokinase therapy corresponding to only one third of the dose usually recommended.

Heart Valve Prosthesis↗

PubMed1995

Cells from peripheral tissues that exhibit high APP expression are characterized by their high membrane fusion activity.

The amyloid precursor protein of Alzheimer's disease (APP) is ubiquitously expressed suggesting a general function throughout the organism. We have used APP-specific antibodies to investigate the expression and localization of APP in different tissues from rat (testis, ovary, liver, kidney, spleen, pancreas, salivary gland). Immunohistochemistry demonstrated that APP is highly expressed in Sertoli cells, follicle cells, secretory cells, podocytes and macrophages. Features common to these cells include their high membrane turnover and their functional characteristics of endocytic and phagocytic retrieval and exocytosis. This suggests APP may participate in interactions of cells of the mononuclear phagocytic system, and function in relation to tissue maintenance and repair.

Amyloid beta-Protein Precursor↗

PubMed1994

General and test anxiety, shyness, and grade point average of elementary school children of divorced and nondivorced parents.

116 boys and girls in elementary Grades 4, 5, and 6 were administered the General Anxiety Scale, Test Anxiety Scale, and the Shyness Scale. Their GPAs were obtained from school records as were Normal Curve Equivalents from the Iowa Tests of Basic Skills given the previous school year. Children of divorced parents (n = 31) had lower GPAs than children of nondivorced parents (n = 85). The girls had higher GPAs and general anxiety scores than the boys. The students who scored lower on test anxiety had higher Normal Curve Equivalents. Pearson correlations were significant for scores on Test Anxiety with those on general anxiety (r = .57), GPA (r = -.25), and Normal Curve Equivalents (r = -.26). Normal Curve Equivalents correlated significantly with GPA (r = .66), but shyness did not correlate significantly with any other measure.

Achievement↗

PubMed1994

Multiple personality: self-rape.

Multiple personality disorder is the classification given a person for whom two or more distinct personalities are diagnosed. The personalities can be different and vary in character from aggressive to submissive (victimized). The victim alters can be abused and abuse or mutilate self to relieve anxiety or guilt (deserving punishment) or to exert control. Alters may provide a means of expressing anger or other feelings. Aggression towards the body may be sexually oriented, so one may ask whether aggression could make self-rape possible. If so, such expression of self-injuries may be observed in a person with multiple personality as when one alter may injure another. Clinical case material is presented on this concept for a woman who had been formally diagnosed with multiple personality disorder.

Adult↗

PubMed1993

Shigella flexneri 2a and sonnei I vaccine with two attenuating markers: construction, tolerability and immunogenicity in 143 children aged 3-17 years.

The vaccine candidates were constructed through stepwise incorporation of weakly attenuated purine auxotrophy with subsequent rifampicin resistance (RNA polymerase) mutation to yield optimal attenuation. These strains showed a maintained invasiveness for conjunctival epithelia. Therefore, while not causing keratoconjunctivitis, they were excreted for a short but marked period and provided partial protection in the Sereny test. Children tolerated the maximum dose of 1-3 x 10(9) colony-forming units (c.f.u.) of lyophilized vaccine without side effects. This total dose distributed among three oral inoculations, induced coproantibodies in 70% of recipients during the first three months. However, the single application of this total dose for primary immunization or booster proved to be more efficient: 90% of the subjects had markedly elevated titres for not less than six months.

Administration, Oral↗

PubMed1993

Passive viewing of the Necker cube during massed and distributed practice.

Of 24 students from a psychology class in high school 12 were randomly assigned to a Massed Practice group (4 boys, 8 girls each) and 12 to a Distributed Practice group. They viewed a Necker cube for a 3-min. trial on three occasions separated by a week. The Massed Practice group had no rests while the Distributed Practice group rested 1 min. after each 1 min. of viewing. There were no significant differences for total reversals between Massed and Distributed groups on any trial. There were no significant differences between boys and girls on Trials 1 and 2, but on Trial 3 boys reported significantly more reversals than girls. Within each group there was a significant increase in the number of reversals from Trial 1 to Trial 3, indicating learning effects. Rigidity scores did not correlate significantly with the total Necker cube reversals for Trials 1, 2, or 3. The massed and distributed practice effects were not present although learning was noted. Longer rests may be needed for practice effects within trials; long rests of 7 days between trials may account for lack of differences.

Adolescent↗

PubMed1992

Specific and diversive curiosity in gifted elementary students.

Twenty-nine gifted students in Grades 2 to 6 from the small school districts in north central Kansas completed the Maze test and the Which-to-Discuss test. Background information such as age, sex, grade, and marital status of parents was also collected. There were no significant differences between boys and girls or for students from divorced and nondivorced parents on either the Which-to-Discuss test (specific curiosity) or the Maze test scores (diversive curiosity). The students scored significantly higher on the former test than chance guessing which suggests the students were displaying specific curiosity. Scores of these gifted students on these two tests of curiosity were significantly and positively correlated.

Attention↗

PubMed1992

Aggression of youth as related to parental divorce and eye color.

Among 214 youth in Grades 5 to 12, students classified by eye color did not differ in aggression or hostility although boys scored higher on Assault and girls scored higher on Indirect Hostility. Also, children of divorced parents scored higher on Aggression, Resentment, and Assault as previously reported.

Adolescent↗

PubMed1992

Relationships between scores on the DIAL-R concepts scale and SRA scores.

42 children, brought for preschool screening from rural north central Kansas school districts, were administered the concepts area of the Developmental Indicators for the Assessment of Learning--Revised, and after the children had started school, the SRA scores were collected from their files. The 20 boys were absent more often than the 22 girls during Kindergarten. There was no sex difference on the concepts area of the DIAL--R. In Grade 1 girls had higher SRA Composite scores. The scores on the DIAL--R concepts area correlated (.36 to .68) with Kindergarten SRA scores and Grade 1 SRA scores, in part, because the DIAL--R concepts area covers the material presented and learned in Kindergarten and screens for material presented in Grade 1. Screening devices may be a useful first step in developing comprehensive assessment plans for children.

Achievement↗

PubMed1992

Rubinstein-Taybi syndrome.

Rubinstein-Taybi Syndrome was first described in 1957 but only in 1963 as a distinguishable type of moderate mental retardation. The cause is still unknown although some type of genetic origin is possible. No consistent chromosomal abnormality has been demonstrated, the chromosomal analysis is normal, and cases are generally not considered hereditary. The recurrent risk for siblings is approximately 0.1% but may be as high as 50% for offspring of patients with the syndrome. The Rubinstein-Taybi syndrome is not at present detectable before birth and is evenly found in both males and females. The syndrome was thought to be rare but an increase in the number of reported cases each year suggests it is not as rare as estimated. It is thought to occur in about 1 in 300,000 births, and since it has become readily identifiable, more than 400 cases have been reported worldwide.

Abnormalities, Multiple↗

PubMed1992

Depression, suicide ideation, and aggression among high school students whose parents are divorced and use alcohol at home.

106 high school students from a small rural high school completed the Children of Alcoholics Scale, Zaks and Walters' Aggression Scale, Beck Depression Scale, and a modified version of the Beck Scale of Suicide Ideation. Analyses of variance showed boys were not experiencing suicide ideation any more than girls; suicide ideation was similar across the four grades, but on aggression alcohol-dependent boys scored significantly higher than girls, and in Grade 9 boys' scores were significantly higher than those in Grade 10. The sophomores' scores on alcohol dependency were significantly lower than the freshmen's scores. Boys and children from divorced homes had higher scores on aggression than girls and children from nondivorced homes. Children from homes in which alcohol was used had higher depression scores than children from nonalcoholic homes. Freshman girls and sophomore boys had higher depression scores than senior boys and girls. A Pearson r of 0.28 between scores on alcohol dependency and suicide ideation was significant, but research is needed to understand better the associations of thoughts of suicide and drug-alcohol dependency among these high school students so strategies for prevention and intervention can be focused.

Adolescent↗