Distinct role of Rab3A and Rab3B in secretory activity of rat melanotrophs.

Members of the Rab3 (A-D) subfamily of small GTPases are believed to play a key role in regulated exocytosis. These proteins share approximately 80% identity at amino acid level. The question of whether isoforms of Rab3 are functionally redundant was the subject of this study.

The middle cerebral artery flow velocities during head-up tilt testing in diabetic patients with autonomic nervous system dysfunction.

Background: The goal of this study was to examine the effects of diabetes mellitus on the trend of mean arterial velocity (v(m)) in both middle cerebral arteries during head-up tilt (HUT).

Methods: The study was performed in 20 patients, 9 females and 11 males (mean age 51 +/- 12 years) with an average 17-year history of insulin-dependent diabetes mellitus type I or II and a dysfunction of the autonomic nervous system confirmed by cardiocirculatory tests [Valsalva maneuver, deep breathing test, handgrip test, orthostatic test and spectral analysis of heart rate (HR) variability], and 19 age-matched healthy volunteers, 9 females and 10 males (mean age 48 +/- 6.8 years).

Testing of cerebral endothelium function with L-arginine after stroke.

Background: Endothelium-dependent vasodilatation could be impaired during hypoperfusion. L-arginine (L-A), a precursor of nitric oxide, is able to elicit endothelium-dependent vasodilatation. To determine cerebral vascular endothelial function in the early stages after ischemic stroke, we studied cerebrovascular reactivity to L-A with transcranial Doppler (TCD).

The influence of brightness, colour and complexity on visual evoked doppler flow responses.

The purpose of this study was to evaluate specific influence of colour, brightness and complexity on visual evoked flow responses (VEFRs). A total of 31 healthy subjects aged 35.1 +/- 7.

The effect of age on cerebrovascular reactivity to cold pressor test and head-up tilt.

Objective: To compare the cold pressor test (CPT) and head-up tilt (HUT) responses of the older and younger healthy individuals by transcranial Doppler.

Subjects And Methods: Forty healthy volunteers were divided into two age groups (18-39 years, 40-69 years). Mean blood velocity (v(m)) in both middle cerebral arteries was monitored during CPT and HUT.

Influence of the cold pressor test on the middle cerebral artery circulation.

Cold pressor test (CPT) evokes generalized activation of the sympathetic nervous system (SNS). The activity of SNS may be estimated by monitoring the mean blood velocity (v(m)) in the middle cerebral artery (MCA) by using a transcranial Doppler monitoring system (TCD). To determine the response of SNS, we studied the v(m) during CPT.

Heart rate variability, norepinephrine and ECG changes in subarachnoid hemorrhage patients.

While electrocardiographic abnormalities in subarachnoid hemorrhage patients have been known since 1947, the provocative mechanism has not yet been satisfactorily explained. The purpose of this study was to evaluate with some tests, the role of autonomic nervous system in provoking the electrocardiographic abnormalities in 22 patients with subarachnoid hemorrhage. The standard electrocardiographic tracings and one-channel computer-based electrocardiographic tracings for spectral analysis of heart rate variability were made.

Cardiac arrhythmia associated with reversible damage to insula in a patients with subarachnoid hemorrhage.

Background: The insular cortex has been shown experimentally to contain an arrhythmogenic center that may play an important role in the genesis of cardiac arrhythmias and electrocardiographic changes in patients with intracranial (eg, cerebrovascular) lesions. The description of our case is intended to substantiate this claim with a clinical observation.

Case Description: A 37-year-old woman with subarachnoid hemorrhage suffered a severe reversible cardiac arrhythmia after neurosurgical clipping of an arterial aneurysm and removal of an intracerebral hematoma from the region of the left insula.

Autonomic function testing in patients with migraine.

Autonomic nervous system function was studied in 62 patients with migraine. The Valsalva maneuver, deep breathing test, sustained handgrip test, orthostatic test and spectral analysis of heart rate variability in the supine and standing positions were performed in a group of 62 patients of both sexes, aged 21 to 50 years, and in an age-matched control group of 45 healthy volunteers. Heart rate increases during sustained handgrip was significantly reduced in the headache group, when compared to the control group, while the results of the remaining cardiovascular tests did not significantly differ between the control and headache groups.

The influence of the type, duration, severity and levodopa treatment of Parkinson's disease on cardiovascular autonomic responses.

The influence of the type, duration, severity and levodopa treatment of Parkinson's disease on autonomic involvement has been assessed. The Valsalva manoeuvre, deep breathing, handgrip and orthostatic tests were performed in 50 patients with Parkinson's disease and in a control group of 30 healthy subjects. No attempt was made to classify further patients with parkinsonian features into groups such as the Shy-Drager syndrome or multiple system atrophy.

A comparison of cardiovascular reflex tests and spectral analysis of heart rate variability in healthy subjects.

Determination of whether results of cardiovascular reflex tests and spectral analysis of heart rate variability are age dependent and whether there is correlation between results of both, cardiovascular reflex tests (the Valsalva manoeuvre, deep breathing test, handgrip test, cold face stimulus test, orthostatic test) and spectral analysis of heart rate variability were performed on 83 healthy volunteers of both genders, aged 21 to 70 years. We found that results of all heart rate based tests and results of spectral analysis decreased with aging, while results of blood pressure based tests did not. Parasympathetic activity predominated in younger subjects, while in older subjects sympathetic activity was dominant.

Autonomic function testing in patients with tension-type headache.

Autonomic nervous system function was studied in 51 patients with tension-type headache. The Valsalva manoeuvre, deep breathing test, sustained handgrip test, orthostatic test and spectral analysis of heart rate variability in the supine and standing positions were performed in a group of 51 patients of both sexes aged 21 to 50 years and in an age-matched control group of 45 healthy volunteers. Diastolic blood pressure increase and particularly heart rate increase during sustained handgrip were significantly reduced in the headache group, when compared to the control group, while the results of the remaining tests did not significantly differ between the control and headache groups.

Effect of elevated plasma norepinephrine on electrocardiographic changes in subarachnoid hemorrhage.

We compared electrocardiographic abnormalities and plasma norepinephrine concentrations in 40 patients with subarachnoid hemorrhage within the first 24 hours, at 72 hours, and after 1 week. In 20 patients with high plasma norepinephrine concentrations within the first 24 hours, sinus tachycardia (p less than 0.02) and negative T waves (p less than 0.

Activity, molecular forms, and cytochemistry of cholinesterases in developing rat diaphragm.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were studied in the diaphragm of early postnatal rats, using radiometric determination of enzyme activities, velocity sedimentation for separation of molecular forms, and electron microscopic cytochemistry to localize enzymes. AChE activity did not change significantly during the first 2 months after birth. The level of 16 S AChE was high at early stages, but decreased to adult levels between days 19 and 32 after birth.

Cholinesterases of neuromuscular junction.

The ultrastructural localization of AChE and BuChE was studied in motor endplates of the rat and mouse diaphragms, using the CNS(?) modification of the one-step Cu-thiocholine procedure. AChE activity was observed on pre- and postsynaptic membranes, in the basal lamina and in the Schwann cell-nerve terminal interspace. The localization of BuChE was similar but much less pronounced in the adult muscle, while for the developing muscle, the reverse was true.