Arginine and tetrahydrobiopterin supplementation in rats with salt-induced blood pressure increase: minor hypotensive effect but improvement of renal haemodynamics

High salt (HS) intake can lead to hypertension, probably the result of the predominance of vasoconstrictor reactive oxygen species over vasodilator nitric oxide (NO). We aimed to examine if the supposed NO deficiency and the resultant blood pressure increase could be corrected by supplementation of L-arginine, the substrate, and tetrahydrobiopterin (BH4), a co-factor of NO synthases. Wistar rats without known genetic background of salt sensitivity were exposed to HS diet (4%Na) for 10 or 26 days, without or with supplementation with oral L-arginine, 1.4 mg/kg b.w. daily, alone or together with intraperitoneal BH4, 10 mg/kg daily. Systolic blood pressure (SBP, tail-cuff method) was measured repeatedly and found to increase ~40 mmHg after 26 days; L-arginine and BH4 did not significantly attenuate this increase. At the end of chronic studies, in anaesthetized rats the diet- and treatment-induced changes in renal haemodynamics were assessed. HS diet selectively decreased (-30%, P < 0.03) the inner medullary blood flow (IMBF, laser-Doppler flux) without changing total or cortical renal perfusion. Arginine supplementation tended to raise all renal circulatory parameters, and distinctly increased IMBF, to 61% above the HS diet level (P < 0.05). In conclusion, unlike in confirmed genetically determined salt-dependent hypertension, L-arginine and BH4 supplementation failed to attenuate the SBP increase observed after exposure to HS diet. On the other hand, arginine increased total and regional renal perfusion, especially IMBF. This suggests that the delivery of arginine increased intrarenal NO synthesis, an action of renoprotective potential which presumably countered the harmful influence of the local tissue oxidative stress.

Extensive mixed vascular malformation clinically imitating multiple sclerosis--case report

Vascular malformations usually develop as a result of influence of teratogenic factor(s) acting in the defined embryonic/fetal period. However, in the case examined by us, various types of vascular malformations formed in different periods of the ontogenic development were found. They were seen in all parts of the central nervous system and clinically mimicked multiple sclerosis. On the background of generalized ischemic lesions of the CNS, certain kinds of vascular malformations were seen: cavernous or fetallike vessels within meninges, superficially located capillary angioma penetrating into the brain and spinal cord white matter, and arterio-venous pathological conglomerates forming meningeal angiomatosis. In pathological vessels, immunocytochemical assessment of vascular endothelium with antibodies against antigens CD31, CD34, von Willebrand factor and lectin Ulex europaeus was normal but examination of the vascular basal membrane compounds revealed poor immunoreactivity to laminin and fibronectin. There were no disturbances in expression of angiopoietin, platelet-derived growth factor, transforming growth factor beta and vascular endothelial growth factor receptors Tie-1/2, PDGFR-alpha/beta, endoglin and Flk-1, respectively. The presence of various types of pathological vessels originating from different ontogenic periods indicates remittent or prolonged influence of teratogenic factor(s) in all periods of fetal vessel development.

CADASIL: new cases and new questions

We described the first two unrelated Polish families with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). In the morphological examination with light microscopy, two kinds of changes were observed: (1). panarteritis nodosa-like changes with eosinophilic fibrinoid necrosis of the vessel wall and perivascular inflammatory infiltrates and (2). basophilic granular material in the tunica media characteristic of CADASIL. At electron microscopy, we found deposits of granular osmophilic material (GOM) within the wall of arteries, veins and capillary vessels. Our findings imply two questions requiring further investigation: Why in the genetically determined vascular disorder are the features of systemic inflammatory vascular disease present? Why in capillary walls deprived of smooth muscle cells are deposits of GOM present?

Early ontogenic disturbances in cell migration in mentally disabled adult

Disturbances in cell migration are heterogenic disorders of brain development commonly associated with epilepsy and mental retardation. We report a 45-year-old oligophrenic man with defect of lower limbs and family history of mental retardation who died because of brainstem hemorrhage. At post-mortem and histopathological examination, complex brain malformation characterized by bilateral periventricular heterotopia, cortical dysgenesia, partial agenesia of corpus callosum and thin-walled blood vessels was found. Immunohistochemical examination revealed the presence of fibronectin, collagen IV and laminin in wall of pathological vessels. Cyclooxygenase-2 (COX-2) expression in neurons within heterotopias and dysgenic cortex was negative. It may indicate their maturity and indirectly, normal activity of postsynaptic NMDA receptors that explains absence of epileptic attacks in our patient. The presence of COX-2-negative neurons and compounds of basal lamina in fetal-like vessels within heterotopias and dysgenic cortex, suggests that these probably initially immature structures became mature during 45 years of patient's life.

[Case of Fahr's syndrome]

Convulsions, extrapyramidal-cerebellar syndrome and coma led within 8 weeks to death of a 40-year-old woman. Autopsy demonstrated calcifications in the ganglia of brain base and cerebellum.

[Diagnostic value of cerebrospinal fluid oxyhemoglobin and bilirubin determination in cerebrovascular diseases]

The levels of oxyhaemoglobin and bilirubin were determined in the cerebrospinal fluid in 46 cases of subarachnoideal haemorrhage and cerebromeningeal haemorrhage, 18 cases of haemorrhagic infarction. Autopsy confirmation was available in 18 cases of haemorrhages and 18 cases of infarction. Determination of oxyhaemoglobin and bilirubin levels in the cerebrospinal fluid is not sufficient as a reliable basis for differentiating between cerebral haemorrhage and haemorrhagic infarction. High values of oxyhaemoglobin and bilirubin seem to indicate bleeding into the cerebrospinal fluid spaces. Assessment of oxyhaemoglobin level and cerebrospinal fluid sediment suggests in some cases the diagnosis.

Histological and electrophysiological changes of the lower motor neurone with aging

Maximal motor conduction velocity of ulnar nerve was measured in 7 patients 80-93 years old, who suffered from cerebro-vascular stroke. In 2 cases motor conduction velocity was significantly decreased. Specimens for histopathological study were taken from the spinal cord at the C8 and Th1 segments and from the ulnar nerve at the elbow level on the side opposite to the hemiparesis. In 100 sections of each senile case and in 3 control cases of younger individuals the motoneurons of the retro-postero-lateral nucleus with visible nucleoli were counted. In the ulnar nerve qualitative and quantitative examinations were performed. The study showed a significant loss of motoneurons in the nucleus and a loss of myelinated fibers especially the thickest ones in the ulnar nerve in elderly cases. In teased preparations axonal degeneration and segmental demyelination of some fibers were seen. Morphological changes in some cases, resulted in a slowed down motor conduction velocity.

[Usefulness of volumetric studies in the evaluation of respiratory efficiency in nervous system diseases]

In nervous system diseases impairing the efficiency of respiratory muscles the authors determined vital capacity, minute ventilation and respiratory capacity. On the basis of volumetric investigations the authors tried to find an optimal schedule for administration of drugs in myasthenia and determine the usefulness of volumetric and gasometric measurements for the evaluation of respiratory efficiency in neurological diseases.

[Complications arising from the use of controlled respiration in patients with neurological diseases]

The authors applied controlled respiration in 112 cases of central nervous system diseases, polyneuropathies and myasthenia. During clinical observation or on autopsy in 30 cases complications were found in the form of subcutaneous and mediastinal emphysema or pneumothorax, narrowing or chondromalacis of the trachea, granuloma formation, decubitus ulcers in the trachea with or without bleeding, and haemorrhagic-ulcerative tracheitis. In 7 cases (6.25%) these complications caused death. Factors leading to complications and their prevention are discussed.

On pure motor hemiplegia (Fisher's syndrome)

The authors described three cases of so-called "lacunar strokes" with pure motor hemiplegia. Clinical diagnosis in all three cases was middle cerebral artery thrombosis. In cases 1 and 2 small post-malacic lacunes were found in the basal part of the pons. In case 3 the lesion was located in the pyramidal tract within the pons and medulla. In all cases advanced arteriosclerotic changes were observed. "Lacunar stroke" can result from a lesion of both the pons and the medulla. The clinical syndrome may be engendered also by selective lesion of the pyramidal tract.