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Biomedical subjects

M G Fiori

Publications and source records attributed to M G Fiori.

At least 19 recordsLinked to original sources

Domenico Battini and his description of congenital megacolon: a detailed case report one century before Hirschsprung.

More than one century after the epochal paper of Harald Hirschsprung, and in spite of fast and remarkable advances in the pathophysiology of congenital megacolon, our understanding of how bowels may become functionally obstructed, and especially its variability, remains largely incomplete. While much more needs to be known about normal gastrointestinal physiology, an interaction between genetic and environmental factors seems to be of paramount importance in the pathogenesis of Hirschsprung's disease. While reviewing the relevant literature, we came across a virtually unknown contribution by an Italian physician, Domenico Battini, who happened to follow-up for about 10 years a case of severe constipation. This contribution, published posthumously as a book in 1800, not only describes very carefully the clinical evolution of that patient, but also provides a detailed post-mortem examination of the abdominal viscera, with particular reference to the alterations occurred in the intestines. We conclude that Battini, nearly one century before Hirschsprung, had succeeded in reporting a typical case of congenital megacolon, and had perceived a number of features (familiarity, selective involvement of "neural layers" in the gut mucosa) that were to become characteristic of Hirschsprung's disease a few decades after Hirschsprung himself had published his article.

Hirschsprung Disease↗

Opioid peptide gene expression in the primary hereditary cardiomyopathy of the Syrian hamster. I. Regulation of prodynorphin gene expression by nuclear protein kinase C.

Prodynorphin gene expression was investigated in adult ventricular myocytes isolated from normal (F1B) or cardiomyopathic (BIO 14.6) hamsters. Prodynorphin mRNA levels were higher in cardiomyopathic than in control myocytes and were stimulated by treatment of control cells with the protein kinase C (PKC) activator 1, 2-dioctanoyl-sn-glycerol. Both chelerythrine and calphostin C, two PKC inhibitors, abolished the stimulatory effect of the diglyceride and significantly reduced prodynorphin gene expression in cardiomyopathic myocytes. Nuclear run-off experiments indicated that the prodynorphin gene was regulated at the transcriptional level and that treatment of nuclei isolated from control cells with 1, 2-dioctanoyl-sn-glycerol increased prodynorphin gene transcription, whereas chelerythrine or calphostin C abolished this transcriptional effect. Direct exposure of nuclei isolated from cardiomyopathic myocytes to these inhibitors markedly down-regulated the rate of gene transcription. The expression of PKC-alpha, -delta, and -epsilon, as well as PKC activity, were increased in nuclei of cardiomyopathic myocytes compared with nuclei from control cells. The levels of both intracellular and secreted dynorphin B, a biologically active product of the gene, were higher in cardiomyopathic than in control cells and were stimulated or inhibited by cell treatment with 1,2-dioctanoyl-sn-glycerol or PKC inhibitors, respectively.

Animals↗

Unusual ultrastructural features in intrafascicular ganglion cells of the rat pelvic nerve.

The incidental finding of four ectopic ganglion cells within the pelvic nerve of a normal rat prompted a thorough electron microscopic investigation of the ultrastructural features of these neurons. They were found to enwrap presynaptic terminals inside crater-like invaginations; the appositional surfaces were made more complex by the presence of slender dendritic appendages and sheet-like processes of glial cells. The presynaptic elements contained both clear and dense-cored vesicles, and appeared similar to those characterizing SIF (paraneuronal) cells. In addition, cilia were encountered in both the invaginated processes and most of the Schwann cells associated with the pre- and postsynaptic nerve cells and their processes. Overall, these features were deemed worth reporting because 1) of the unusual features of synaptic input from a SIF cell to a ganglion cell associated with the pelvic plexus, and 2) the ectopic ganglion cells possibly represent the sole example, other than ciliary neurones in the avian ciliary ganglion, of postsynaptic cells encasing presynaptic endings inside their perikarya.

Animals↗

Down-regulation of evoked synaptic release in rat neuromuscular junction.

Spontaneous and evoked synaptic transmission were studied at the rat extensor digitorum longus (EDL) neuromuscular junction in the presence of CGIIIA mu-conotoxin, a peptide which suppresses action potential in the sarcolemma, while not affecting impulse conduction along motor nerve fibers. The binomial parameters m (mean quantal content) and n (number of units involved in evoked quantal release) increased as a function of extracellular Ca++ ([Ca++]o), up to the physiological concentration (2 mM). Additional Ca++ failed to induce a statistically significant increase in either m or n, while the probability of activation (p) did increase, approaching unity at 4 mM [Ca++]o. In cut EDL preparations, without CGIIIA, the relation between end-plate potential amplitude and [Ca++]o resembled that for quantal content in unlesioned, CGIIIA-treated muscles. In contrast, normal preparations exposed to 0.5 mg/ml d-tubocurarine were much more responsive to Ca++ variations, with a significant end-plate potential amplitude increase in the presence of 4 mM [Ca++]o. However, in curarized preparation the evoked release was remarkably affected by repetitive stimulation, while in the absence of postsynaptic blockers release levels were more stable. We suggest that the stimulatory effect of extracellular Ca++ on evoked release at the mammalian neuromuscular junction might normally be depressed under physiological conditions, possibly by a down-regulation mechanism involving presynaptic nicotinic receptors. Such inhibition would increase nerve transmission efficiency during prolonged motor terminal activity.

Animals↗

An Italian kindred with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Vascular dementia is usually sporadic and associated with definite risk factors. Several cases also occur in a familial fashion, and may affect middle-aged or even younger subjects. Recently, an autosomal dominant inheritance was demonstrated in two unrelated French families, the members of which were affected by stroke-like episodes culminating in progressive dementia. Genetic linkage analysis assigned the disease locus to chromosome 19q12. We report an additional kindred of Italian origin in which at least 16 subjects presented leukoencephalopathic alterations. Recurrent strokes, psychiatric disturbances, dementia, and in 2 members, tetraplegia and pseudobulbar palsy were the hallmarks of this syndrome. Notably, 5 asymptomatic individuals had neuroradiological signs of leukoencephalopathy. Pathological examination of 1 subject revealed a widespread vasculopathy of the perforating arterioles, characterized by deposition of eosinophilic-congophilic material that did not immunostain with antibodies against prion protein, beta-amyloid, cystatin C, transthyretin, or heat-shock protein 70 and was similar to that described in the French families. Based on the maximum lod score, the most likely location for the disease locus was also mapped to chromosome 19q12, and found to coincide with the CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) locus. The present results confirm the existence of a nosologically distinct, autosomal dominant cerebrovascular disease, presenting with recurrent subcortical ischemic strokes independent of vascular risk factors.

Adult↗

Defective activity of Na+,K(+)-ATPase in peripheral nerve of diabetic rats is independent of the axonal transport of the enzyme.

This study addressed the question as to whether the reduced activity of Na+,K(+)-ATPase reported to occur in diabetic nerves and to play a crucial role in the pathogenesis of diabetic neuropathy could be due to derangements in the axonal transport of the enzyme. A micromethod was developed to evaluate the ATPase accumulation in individual segments of ligated sciatic nerves from streptozotocin-induced diabetic rats. The results confirmed a approximately 40% decrease in the background activity, but showed that the enzyme was transported at similar rates in both anterograde and retrograde directions, suggesting that the decrease in its activity does not depend on an altered delivery along the axons.

Analysis of Variance↗

Spontaneous isolated lipoma of the choroid plexus in the baboon.

A case of symptomless, solitary lipoma of the choroid plexus is described. The tumour was found in the left lateral ventricle of an adult female baboon (Papio papio) in the course of post-mortem examination. Routine histological investigation showed that the tumour was composed exclusively of characteristic adipose cells with scarce collagen septa and without other hamartoma-like constituents, such as glial cells, neurons, cartilage or muscle fibres. The tumour mass was lined by a typical single layer of cuboidal cells; no calcifications were observed either inside the tumour or in the adjacent periventricular regions. This case is reported in view of the rarity of such tumours of the choroid plexus in man and animals, and to throw light on their possible origin.

Animals↗

Urinary bladder dysfunction in the BB/W diabetic rat: effect of ganglioside treatment on functional and structural alterations.

Urinary bladder dysfunction in the diabetic BB/W rat is characterized by infrequent irregular contractions of high amplitude. Initially these occur in the absence of detectable neuroanatomical lesions of sensory afferent and parasympathetic fibers of the pelvic nerve, which constitute the micturition reflex arc. Structural lesions consisting of progressive axonal atrophy of myelinated and unmyelinated fibers become detectable only after 4 months of diabetes. In the current study we evaluated the effect of ganglioside treatment (10 mg./kg. body weight) for one month. This drug regimen was initiated at 4 months of diabetes, when functional bladder abnormalities were well established, whereas structural lesions were yet to appear. Animals examined 1 or 3 months after termination of the one-month treatment protocol showed sustained normalization of the characteristic functional abnormalities, accompanied by prevention of the neuroanatomical lesions of sensory afferent and parasympathetic efferent myelinated fibers in the pelvic nerve. These data suggest that ganglioside treatment may be beneficial in delaying the progression of diabetic autonomic neuropathy in this experimental animal model.

Animals↗

Amyloid deposits inside myocardial fibers in transthyretin-Met30 familial amyloidotic polyneuropathy. A histological and biochemical study.

A case of severe cardiac involvement is reported in a patient affected with familial amyloidotic polyneuropathy due to the Portuguese type I variant (Val-->Met30) of the transthyretin (prealbumin) molecule. Echocardiographic and hemodynamic studies suggested the presence of a progressive infiltrative cardiomyopathy that was later confirmed by endomyocardial biopsy. Amyloid deposits were found in both intra- and extra-myofiber location and thought to be related to primary involvement of the heart. Norepinephrine content of myocardial bioptic specimens was about threefold lower than normal, indicating that autonomic denervation may contribute to the maintenance and progression of cardiomyopathy. A sample obtained from the sural nerve showed a loss of myelinated fibers along with accumulation of amyloid masses in the endoneurial space. This histopathologic pattern correlated with a sharp decrease in the activity of the enzyme subserving electrochemical conduction through the axonal membrane, Na+, K(+)-ATPase.

Amyloid↗

Decrease of nerve Na+,K(+)-ATPase activity in the pathogenesis of human diabetic neuropathy.

A decrease in Na+,K(+)-ATPase activity is claimed to play a central role in the pathogenesis of electrophysiological and morphological abnormalities that characterize the neuropathic complications in different animal models of diabetes mellitus. The peripheral nerves from 17 patients with either type I or type II diabetes mellitus were studied to assess the importance of changes in Na+,K(+)-ATPase activity in chronic human diabetic neuropathy. Sixteen nerves from age- and sex-matched normal individuals, and 12 nerves from non-diabetic neuropathic subjects undergoing vascular or orthopedic surgery served as negative and positive controls, respectively. All specimens were processed blind. Ouabain-sensitive ATPase activity was measured by a modified spectrophotometric coupled-enzyme assay. Standard histology, fiber teasing and electron microscopy were used to establish the normal or neuropathological patterns of surgical material. Morphometric analysis permitted calculation of fiber density in each nerve specimen and correlation of this figure with the relevant enzymatic activity. Na+,K(+)-ATPase activity was approximately 59% lower in nerves from diabetic patients than in normal controls (P < 0.01) and approximately 38% lower in nerves from non-diabetic patients with neuropathy (P < 0.01). Although nerves from both neuropathic conditions had significantly fewer fibers than those from normal individuals (diabetic -33%, and non-diabetic -22%), the decreases in Na+,K(+)-ATPase activity and fiber density were not correlated only in specimens from diabetic patients (r2 = 0.096; P = 0.22). Taken together with data from experimental animal models, these results suggest that the reduction in Na+,K(+)-ATPase activity in diabetic nerves is not an epiphenomenon secondary to fiber loss; rather, it may be an important factor in the pathogenesis and self-maintenance of human diabetic neuropathy.

Adult↗

Effect of gangliosides on diacylglycerol content and molecular species in nerve from diabetic rats.

The effects of ganglioside treatment on 1,2-diacylglycerol content and on molecular species in 1,2-diacylglycerol, phosphatidic acid and total diacylglycerolipids, as well as Na+,K(+)-ATPase activity, were examined in sciatic nerves from streptozotocin-induced diabetic rats. Beginning 2 weeks after induction of diabetes, animals were administered mixed bovine brain gangliosides, AGF1, an inner ester derivative of this mixture, or saline for 5 weeks. The levels of 1,2-diacylglycerol and arachidonoyl-containing molecular species in age-matched non-diabetic animals were not affected by ganglioside treatment. In nerves from saline-treated diabetic animals, 1,2-diacylglycerol levels were not reduced, but both Na+,K(+)-ATPase activity and all arachidonyl-containing species except for 18:0/20:4 1,2-diacylglycerol were significantly decreased. The content of 1,2-diacylglycerol was lowered by 23 and 16% in bovine brain ganglioside and AGF1-treated diabetic animals, respectively, and the quantity of 18:0/20:4 1,2-diacylglycerol was also selectively reduced. Ganglioside administration did not affect the diminished levels of arachidonoyl-containing molecular species in 1,2-diacylglycerol, phosphatidic acid or diacylglycerolipids in nerve from diabetic rats. In the same nerves, bovine brain gangliosides partially and AGF1 completely restored Na+,K(+)-ATPase activity. The results suggest that gangliosides depress the content of total 1,2-diacylglycerol and the quantity of 18:0/20:4 1,2-diacylglycerol, specifically, in diabetic nerve. The possible relationship between the corrective action of gangliosides on Na+,K(+)-ATPase activity and the effect of these substances on 1,2-diacylglycerol molecular species composition and metabolism is discussed.

Animals↗

Cognitive decline in the elderly: a double-blind, placebo-controlled multicenter study on efficacy of phosphatidylserine administration.

This double-blind study assesses the therapeutic efficacy and the safety of oral treatment with phosphatidylserine (BC-PS) vs placebo (300 mg/day for 6 months) in a group of geriatric patients with cognitive impairment. A total of 494 elderly patients (age between 65 and 93 years), with moderate to severe cognitive decline, according to the Mini Mental State Examination and Global Deterioration Scale, were recruited in 23 Geriatric or General Medicine Units in Northeastern Italy. Sixty-nine patients dropped out within the 6-month trial period. Patients were examined just before starting therapy, and 3 and 6 months thereafter. The efficacy of treatment compared to placebo was measured on the basis of changes occurring in behavior and cognitive performance using the Plutchik Geriatric Rating Scale and the Buschke Selective Reminding Test. Statistically significant improvements in the phosphatidylserine-treated group compared to placebo were observed both in terms of behavioral and cognitive parameters. In addition, clinical evaluation and laboratory tests demonstrated that BC-PS was well tolerated. These results are clinically important since the patients were representative of the geriatric population commonly met in clinical practice.

Activities of Daily Living↗

An electrophysiological study of visual processing in Alzheimer's disease.

Visual processing of sinusoidally modulated gratings was studied in a group of patients (n = 11) with Alzheimer's disease (AD) and an elderly normal control group (n = 9). Spatial square wave gratings (1.47 c/d) were reversed at a temporal frequency of 4 or 8 Hz. EEG recordings at rest and during visual stimulation were obtained from 20 channels using the 10/20 international system. The power spectrum of the 2nd and 4th harmonic of the stimulation frequency was calculated by Fast Fourier Transform (FFT) at a resolution of 0.25 Hz. Association of activity between occipital, temporal, parietal and central regions was measured by intra- and inter-hemispheric coherence and phase at harmonics of the stimulation frequency. A significant difference (P < 0.01) in evoked activity of the 4th harmonic at O1 and O2 was found between the two groups with less activity in the AD patients. In the AD group there was a significant correlation (P < 0.05) between evoked activity at the 2nd harmonic of the 8 Hz visual stimulation and Mini-Mental State (MMS) score. This correlation was independent of the age effect on MMS. Response phase between O1 and O2 for both 4 and 8 Hz stimuli was close to 0 degree C and coherence had similar values in both groups. Occipital and central regions showed a phase reversal for all harmonic responses to both visual stimuli. The AD patients showed statistically significant (P < 0.05) phase dispersion at O1-P3 and O2-P4 not seen in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Pancreatic gangliosides delay the onset of insulitis and hyperglycaemia in the low-dose streptozotocin mouse model.

Gangliosides have been shown to modulate autoimmune phenomena in experimental diabetes. The effects of a pancreatic ganglioside preparation or of a commercial brain ganglioside mixture on the insulitis and blood glucose levels in the low-dose streptozotocin mouse model of diabetes have been investigated. Fifty-five C57BL/6J male mice were grouped as follows: Group 1 (n = 20) was injected intraperitoneally with repeated low doses of streptozotocin; Group 2 (n = 10) received streptozotocin as above but was also injected with a pancreatic ganglioside preparation equivalent to 2 micrograms sialic acid 2 h before each streptozotocin dose; Group 3 (n = 15) received streptozotocin and brain-derived gangliosides in the same dose as that of pancreatic gangliosides; Group 4 (n = 10) consisted of normal animals. Half of the mice were killed on day 12 and the others on day 24 from the beginning of treatment. On day 12, among the streptozotocin-injected animals only those treated with pancreatic gangliosides remained normoglycaemic, whereas on day 24 all streptozotocin mice were hyperglycaemic. Such a result paralleled the data pertaining to insulitis scores. In conclusion, pancreatic gangliosides have a short-term protective role on the development of diabetes in the low-dose streptozotocin model, an effect therefore linked to tissue-related differences in the glycosphingolipid composition.

Animals↗