Inhibition and executive functioning in Type A and ADHD boys

The present study was aimed at clarifying the standing of Type A behavior, as measured by behavioral observations, relative to Attention Deficit Hyperactivity Disorder (ADHD), using measures of inhibitory control and executive functioning. The study sample included 20 boys exhibiting Type A behavior, 21 boys exhibiting Type B behavior and 14 boys diagnosed with ADHD, ranging in age from 7 to 12 years. The results of the present study showed that the Type A children differed from Type B children on two time-related variables, response latency and reaction time, in accordance with the view of Type As as time-urgent and impatient. Furthermore, in comparisons with the ADHD group, the Type A boys were found to be superior on several performance tasks, such as Go/no-go omissions, time reproduction, story recall and memory for sequences of hand movements, although similarities between Type A and ADHD boys were evidenced in terms of response latency and reaction time. In other words, although Type A boys were similar to ADHD boys in terms of overt displays of time-urgency and impatience, Type As do not display deficits with regard to executive functioning, of the kind often found when ADHD children are compared with normal controls. It may thereby be concluded that Type A behavior and hyperactivity/ADHD appear to be well differentiated except with regard to what may be interpreted as impatience. Speculations concerning differing origins of overtly similar characteristics of Type A behavior and ADHD should be considered in future research.     

Prognostic significance of white matter changes in a memory clinic population

Non-specific white matter changes (WMC) can be seen on neuroimaging of the brain in healthy elderly but are more common in dementia. WMC are correlated to specific cognitive deficits and might also contribute to global cognitive decline. The value of WMC as a predictor of cognitive impairment has been incompletely elucidated. We studied the prognostic significance of extensive WMC in a group of patients with memory disturbances, to evaluate if the presence of such changes predicts a poorer outcome. We retrospectively selected a group of 24 patients with prominent WMC on magnetic resonance imaging (MRI) and with different grades of memory impairment. We matched each patient, with regard to age, education, length of follow-up, initial score on the Mini Mental State Examination (MMSE) and initial diagnosis, to a patient without white matter pathology. The matched pairs were evaluated and the decrease in MMSE score after follow-up (range 2-4 years) was used as the outcome measure. Results showed no difference in the decrease in MMSE score at follow-up between patients with or without WMC. In conclusion, the presence of WMC in cognitively impaired patients had no effect on the progression rate of dementia, as measured by MMSE decline.     

Biochemical markers of cerebrospinal ischemia after repair of aneurysms of the descending and thoracoabdominal aorta

OBJECTIVE: To investigate the clinical potential of several markers of spinal cord ischemia in cerebrospinal fluid (CSF) and serum during aneurysm repair of the descending thoracic or thoracoabdominal aorta. DESIGN: Observational study of consecutive patients. Nonblinded, nonrandomized. SETTING: University hospital thoracic surgical unit. PARTICIPANTS: Eleven consecutive elective patients. INTERVENTIONS: Distal extracorporeal circulation and maintenance of CSF pressure <10 mmHg until intrathecal catheter removal. MEASUREMENTS AND MAIN RESULTS: CSF and serum levels of S100B (and its isoforms S100A1B and S100BB), neuronal-specific enolase (NSE), and the CSF levels of glial fibrillary acidic protein (GFAp) and lactate were determined. Two patients had postoperative neurologic deficit. One with a stroke showed a 540-fold increased GFAp, a 6-fold NSE, and S100B increase in CSF. One with paraplegia had a 270-fold increase in GFAp, a 2-fold increase in NSE, and 5-fold increased S100B in CSF. One patient without deficit increased GFAp 10-fold, NSE 4-fold, and S100B 23-fold in CSF. CSF lactate increased >50% in 6 of 9 patients without neurologic deficit. Serum S100B increased within 1 hour of surgery in all patients without any concomitant increase in CSF. S100A1B was about 70% of total S100B in both serum and CSF in patients with or without neurologic defects. S100B in CSF increased 3-fold in 3 of 9 asymptomatic patients. CONCLUSIONS: In patients with neurologic deficit, GFAp in CSF showed the most pronounced increase. Biochemical markers in CSF may increase without neurologic symptoms. There is a significant increase in serum S100B from surgical trauma alone without any increase in CSF.     

Place of genotyping and phenotyping in understanding and potentially modifying outcomes in peritoneal dialysis patients

With the landmark publication of the human genome sequence and its subsequent division into haplotype blocks, the characterization of genetic variations is becoming a feasible approach to study both the pathophysiology and risk factors of complex traits. A number of strategies are available today for identifying candidate genes or polymorphisms associated with pertinent phenotypes. For Mendelian diseases with high penetrance owing to mutations in a single gene, such as polycystic kidney disease, linkage studies have been very successful in mapping the disease loci owing to the availability of families with multiple affected members. In contrast to monogenic conditions, complex diseases such as end-stage renal disease (ESRD) and complex traits such as individual variations in membrane transport and complications during the course of peritoneal dialysis (PD) therapy have a number of competing determinants and inhibitors, both genetic and environmental. Current results reflect this complexity, with few studies showing a large effect of any single risk factor on survival or outcome on PD. However, these studies have so far been small (less than 500 patients) and have not utilized bioinformatics or novel technologies (e.g., multiplex genotyping equipment). In the following review, we outline current approaches for using genetic data in clinical studies as well as highlight some of the most promising results in ESRD patients, particularly those on PD.     

An ultrastructural study of serially sectioned Renshaw cells. II. Synaptic types

Boutons and synaptic contacts on 17 presumed Renshaw cells were studied ultrastructurally. All 17 neurons were postsynaptic to axon collateral boutons of intracellularly HRP-stained triceps surae α-motoneurons and located in lamina VII, ventromedially to the main motor nuclei.The boutons and synaptic contacts could be classified into two main categories on the basis of the synaptic vesicles: S-type boutons with spherical synaptic vesicles and F-type boutons with flattened vesicles, the α-motoraxon collateral boutons falling into the S-category. In addition, some S-type boutons containing neurofilaments and some being apposed by small presynaptic boutons were observed. The results are discussed in relation to earlier observations on the synaptology of central neurons, particularly spinal α-motoneurons.     

Mood effects of diazepam and caffeine

Changes in mood after administration of Diazepam and Caffeine were analyzed. Six aspects were studied: pleasantness, activation, extraversion, calmness, social orientation and control. In addition to this check list, mood ratings using magnitude estimation of selected adjectives were obtained. It was found that Diazepam decreased feelings of activation and extraversion and increased calmness. Caffeine had no clear effects on the check list, but on the magnitude estimation scale some effects opposite to those of Diazepam were observed. Men reported a higher degree of pleasantness than women after administration of Diazepam. No differences in heart rate were found. Few distinct scale values were utilized on the magnitude estimation scale and the discriminative power was found to be larger for the check list than for the magnitude estimation scale.     

Cardiovascular Effects of Zimelidine and Tricyclic Antidepressants in Conscious Rats *

Abstract: Blood pressure, heart rate and electrocardiograms were recorded in conscious rats during intravenous injections of consecutively increasing doses of zimelidine, amitriptyline, clomipramine, desipramine and imipramine. The tricyclic antidepressants (TCA's) increased blood pressure from low doses and induced shortlasting decreases in blood pressure at higher doses. Heart rate was initially increased by amitriptyline while the other TCA's tended to decrease heart rate dose-dependently. The TCA's prolonged the QRS and QT intervals dose-dependently from low doses and the PR interval from intermediate doses. Zimelidine did not affect blood pressure or heart rate until high doses were given. The PR interval was not affected by zimelidine. Moderate to high doses of zimelidine prolonged the QT length and high doses widened the QRS complex. The results indicate a good cardiovascular tolerance for zimelidine.     

The plasminogen activator activity of arteries and veins in diabetes mellitus

An abnormally low plasminogen activator activity of the vein walls is strikingly common in diabetes. We found a close correlation between the activator content of the veins and arteries in diabetics, which indicates impairment of the defence system against deposition of fibrin also in diabetic arteries. This might perhaps help to explain the high frequency of early and widespread degenerative arterial lesions in diabetes mellitus.     

Education increases reserve against Alzheimer’s disease—evidence from structural MRI analysis

Introduction

The aim of this study was to determine whether years of schooling influences regional cortical thicknesses and volumes in Alzheimer’s disease (AD), mild cognitive impairment (MCI), and healthy age-matched controls.

Methods

Using an automated image analysis pipeline, 33 regional cortical thickness and 15 regional volumes measures from MRI images were determined in 121 subjects with MCI, 121 patients with AD, and 113 controls from AddNeuroMed study. Correlations with years of schooling were determined and more highly and less highly educated subjects compared, controlling for intracranial volume, age, gender, country of origin, cognitive status, and multiple testing.

Results

After controlling for confounding factors and multiple testing, in the control group, subjects with more education had larger regional cortical thickness in transverse temporal cortex, insula, and isthmus of cingulate cortex than subjects with less education. However, in the AD group, the subjects with more education had smaller regional cortical thickness in temporal gyrus, inferior and superior parietal gyri, and lateral occipital cortex than the subjects with less education. No significant difference was found in the MCI group.

Conclusion

Education may increase regional cortical thickness in healthy controls, leading to increased brain reserve, as well as helping AD patients to cope better with the effects of brain atrophy by increasing cognitive reserve.