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Biomedical subjects

N Canal

Publications and source records attributed to N Canal.

141 records · Page 8Linked to original sources
PubMedDate not supplied

Cognitive processes in insulin-dependent diabetes.

Cognitive processes in a group of neurologically asymptomatic patients with relatively severe but uncomplicated insulin-dependent diabetes mellitus (IDDM) were studied. In comparison with a homogeneous group of normoglycemic controls, the diabetic group performed significantly worse in global memory, abstract reasoning, and eye-hand coordination tests. The two groups scored similarly in intelligence, concentration and attention, spatial, visual, and psychomotor tests. The neuropsychological deficits did not correlate with the duration or the severity of the disease. Whether these mild neuropsychological deficits are transient or stable or whether they are caused by central nervous system vascular or metabolic dysfunctions or by the emotional influence of the chronic illness on the intellectual and educational development of patients remains unclear. Our findings need to be cautiously interpreted and perhaps could not be extended to diabetic patients with better metabolic control.

Adolescent↗
PubMedDate not supplied

Sensitized nociceptors in reflex sympathetic dystrophies.

Painful neurogenic syndromes commonly diagnosed as reflex sympathetic dystrophy (RSD) may not be the consequence of sympathetic dysfunction. Recent experimental data on the mechanism of hyperalgesia indicate that the primary pathophysiological mechanism of RSD may be sensitization of either peripheral nociceptors, or central neurons, or both. The sympathetic system might be involved in maintaining this condition, but this is not always the case. This presentation is an attempt to interpret clinical neuropathic syndromes on the basis of new scientific knowledge.

Humans↗
PubMedDate not supplied

Centronuclear myopathy with unusual mitochondrial abnormalities.

The case of a 34-years-old man is described with a progressive myopathy characterized by limb weakness and atrophy, involvement of facial, masticatory and extraocular muscles. The prominent features of the muscle biopsy were the presence of centrally located nuclei in most fibers. There was also an atrophy and predominance of type I fibers. Both clinical and morphological features were consistent with the diagnosis of centronuclear myopathy. Electron microscopic studies showed the presence of mitochondria with paracrystalline inclusions near the centralized nuclei but not in the subsarcolemmal position. This hitherto unreported feature led the authors to re-evaluate the hypothesis on the pathogenesis and the nosological classification of this myopathy.

Adult↗
PubMedDate not supplied

Age-related modifications of heart rate during sleep-wakefulness cycle.

Twenty-four-hour monitoring of heart rate is currently used in cardiological practice, but it has been rarely applied to investigate the autonomic nervous system functioning. In the present study we investigated the heart rate of 275 healthy subjects, aged 15-69 years, divided into 11 groups by 5-year periods of age. Our results suggest that the balance between parasympathetic and sympathetic activities changes with advancing age. The parasympathetic activity becomes stronger and during sleep loses its power to modulate bradycardia. The general conclusion of our study is that all the investigations on cardiac autonomic functions are to be performed on age-matched basis.

Adolescent↗
PubMedDate not supplied

Comparison between magnetic resonance imaging and other techniques in 39 multiple sclerosis patients.

Till now there are no specific laboratory tests to confirm the diagnosis of Multiple Sclerosis (MS). For this reason the diagnosis of MS is based on the clinical evidence of central nervous system white matter disease with temporal and spatial dissemination of the lesions. Recent advances in neurophysiology and imaging techniques can provide more objective criteria towards more accurate and earlier diagnosis, detecting clinically unsuspected lesions. We evaluated 39 MS patients (23 definite, 7 probable, 9 possible) by Magnetic Resonance Imaging (MRI), CT scan, Evoked Potentials (EPs) testing and Cerebrospinal Fluid analysis. MRI was abnormal in 34 cases (87%) and CT scan in 14 (36%); EPs were also abnormal in 34 cases. 30 patients had both EPs and MRI alterated and 4 patients had alterated only one of the two investigations. The frequency of EPs alterations was: VEP 74%, Median SEP 44%, Tibial SEP 59% and BAEP 54%. The BAEP was more sensitive than MRI in detecting brainstem involvement. On the other hand MRI was more sensitive than SEPs in detecting somatosensory pathways involvement. The combined use of the two techniques allowed a reclassification of 10 out of 16 possible or probable MS cases.

Adult↗
PubMedDate not supplied

Adenyl cyclase and phosphodiesterase in human cerebral tumors.

Adenyl-cyclase (A-C) and Phosphodiesterase (PDE) behaviour in a large number of human cerebral tumors is reported and compared with that of normal gray and white matter. PDE is much reduced in all oncotypes. Also A-C appears reduced in all tumors except astrocytomas where enzymatic activity is similar to that of gray matter. The Authors tried to explain these changes in activity by relating them to the malignancy of the oncotypes or to their different embryologic origin.

Adenoma↗
PubMedDate not supplied

Study on growth hormone and prolactin secretions in myotonic dystrophy.

Basal and stimulated GH and PRL secretions have been studied in four patients with myotonic dystrophy. High values of basal plasma GH have been occasionally found in two patients. Abnormal plasma GH responses were coexisting with normal ones after each stimulus (oral l-dopa, oral glucose load, arginine infusion, i.v. insulin, i.v. metoclopramide). Basal plasma PRL levels were normal in all patients as well as responses to different stimuli except the response to insulin-induced hypoglycaemia that was abnormal in three patients out of four. It is concluded that in myotonic dystrophy hypothalamic regulatory mechanisms of pituitary functions may be altered because of known thalamic lesions or yet unrecognized hypothalamic ones.

Adolescent↗
PubMedDate not supplied

Peripheral neuropathy in scleroderma.

Nervous system involvement is rare in progressive systemic sclerosis (PSS). We present a clinical pathological and immunological study of two patients with peripheral sensory motor neuropathy and PSS. In both, the sural nerve biopsies showed axonal degeneration with increased endoneurial connective tissue. There were also clusters of myelinated fibres indicating axonal regeneration. Only mild microangiopathic changes were evident in the endo, peri and epineurial vessels. By Western immunoblots, patients' sera contained a band of reactivity to a protein from peripheral nerve identified as collagen type I. Primary involvement of the peripheral nerves during PSS is very unusual. Abnormal production of collagen tissue and presence of microvascular disease are considered to be two possible causes of neuropathy. We think that our results suggest the important role of the connective tissue proliferation in the pathogenesis of PSS neuropathy.

Adult↗