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Biomedical subjects

G Ferrari

Publications and source records attributed to G Ferrari.

At least 343 records · Page 19Linked to original sources
PubMed1981

Thiamin transport by rat small intestine "in vitro": influence of endogenous thiamin content of jejunal tissue.

The relationship between thiamin intestinal transport and phosphorylation in vitro was investigated using everted jejunal sacs from normal rats, rats affected with dietary thiamin deficiency at different degrees and relative pair-fed controls; recovered rats, i.e. severely thiamin-deficient animals, 6 hours after the intravenous injection of 1 mg of thiamin chloride/100 g body weight. The sacs were incubated at 37 degrees for 30 min with 0.2 microM 14C-labeled thiamin. During incubation, the endogenous phosphorylated thiamin undergoes a dephosphorylation, which is lowest in thiamin deficient rats. The jejunal sacs from all experimental groups take up and phosphorylate labeled thiamin: the rate is inversely proportional to the endogenous cellular content of phosphorylated thiamin. The net transport of labeled thiamin is enhanced in thiamin-deficient rats. The labeled thiamin net transport after incubation is linearly related to the labeled phosphorylated thiamin content of intestinal tissue. Thiamin repletion of severely thiamin-deficient rats restore the normal levels of endogenous free and phosphorylated thiamin in the intestinal within 6 hours. In addition after incubation, the labeled phosphorylated thiamin content reverts to the levels of the control, while thiamin net transport remains high.

Animals↗
PubMed1980

Diffuse Rosenthal fiber formation in adults. A case report.

A 20-year-old woman was admitted to the Hospital because of tetraparesis and respiratory failure, requiring mechanical ventilation. No disturbances of consciousness were associated. She had a residual left lower limb paresis from the age of 14, lasting unchanged until this final episode of bulbar paralysis. She did not recover: death occurred 3 months later. Neuropathological examination revealed Rosenthal fibers in the gray and white matter with typical perivascular and subpial distribution. Areas of mild demyelination were found in the periventricular white matter of the centrum ovale and in the hilum of the nucleus dentatus. In the brain stem the highest density of Rosenthal fibers was found in the medulla where the deposits extended deeply into parenchyma. The relationship of this case with Alexander's disease is discussed.

Adult↗
PubMed1979

Relationship between thiamin phosphorylation and intestinal transport in vitro: effect of chloroethylthiamin.

The effect of Chloroethylthiamin (CET), a structural analog of thiamin, on thiamin pyrophosphokinase (TPKase) activity of the supernatant of rat isolated enterocytes was compared with that on thiamin intestinal transport by rat everted jejunal sacs. Thiamin- thiazol-2(14C) was used as a substrate both for TPKase activity and for thiamin serosal transport and uptake. CET strongly inhibited TPKase activity of isolated enterocytes: at molar concentrations 10 or 100 times higher than labeled thiamin, the inhibition was 57 and 100% respectively. The inhibition was of the competitive type, with a Ki = 15 microM. At a molar concentration 10 times higher than labeled thiamin, CET lowered the thiamin serosal transport by 60%, and the sac wall content of free and phosphorylated thiamin by 54 and 42% respectively. At the 1:10 thiamin: CET molar ratio, the extent of the reductions of TPKase activity (57%) and of phosphorylated thiamin content of intestinal sac walls (42%) were of the same order. This indicates a relationship between the two events. Moreover, since TPKase activity inhibition alone resulted in the lowering of labeled thiamin serosal transport, thiamin phosphorylation and transport are probably two strictly related processes.

Animals↗
PubMed1979

Foix-Chavany syndrome: CT study and clinical report of three cases.

The Foix-Chavany syndrome is a neurological entity characterized by linguo-bucco-facial apraxia almost always caused by disturbed cerebral circulation. Three typical cases of this syndrome are described and the role of the CT scan to obtain a definite diagnosis is emphasized.

Adult↗
PubMed1979

Ethical problems in psychopharmacological research.

1. Scientific research poses considerable ethical problems which in human psychopharmacological studies are frequently faced by singling out consent as the only reliable source of human respect, although it is never free, spontaneous, or informed. 2. On the other hand, various ethical problems present in the "life" of a new substance in the case of industry and preclinical, clinical and mass experiments, are left behind. 3. Thus there arise justified protests which go so far as disowning science and technology. To criticize science and technology is of no use: incorrect use of them must be prevented. 4. Such a guarantee can only come from an international control committee, capable of coping with a multinational power such as industry, supported by peripheral elective committees, which grant the citizens a direct participation in the administration of health.

Ethics, Medical↗
PubMed1979

Paraparesis in hereditary multiple exostoses: case report.

The authors report a case of hereditary multiple exostoses (HME) with neurologic complications, and review the literature. A 23-year-old man exhibited a worsening spastic paraparesis with sphincter dysfunction. The cranial nerves and the exteroceptive and deep sensations were apparently undamaged. The family history, the physical examination, and the systemic radiologic examination revealed all the characteristics of HME. The neurologic complication was caused by an exostosis, arising from the C2 right hemilamina, compressing the spinal cord. The patient quickly improved after a laminectomy.

Adult↗
PubMed1979

Thiamine intestinal transport and phosphorylation : a study in vitro of potential inhibitors of small intestinal thiamine-pyrophosphokinase using a crude enzymatic preparation.

Using as enzymatic source the cytoplasmatic fraction of enterocytes isolated from the rat small intestine, thiamine-pyrophosphokinase activity was studied with a radiometric method using [thiazole-2-(14)C] thiamine. The Km value for thiamine was 2.14 X 10(-6) M and V 0.87 nmol of thiamine pyrophosphate mg-1 protein h-1. Eleven thiamine structural analogs and derivatives were assayed for their inhibitory action on the small intestine thiamine-pyrophosphokinase activity. Their Ki values were : pyrithiamine, 2.25 X 10(-6) M; thiamine monophosphate, 4 X 10(-6) M; 2'-ethylthiamine, 8 X 10(-6) M; 2'-butylthiamine, 6 X 10(-6) M; chloroethylthiamine and dimethalium, 1.5 X 10(-5) M; amprolium, 1.8 X 10(-4) M; L-582571, 1.65 X 10(-4) M; oxythiamine, 4.2 X 10(-3) M. Of the miscellaneous compounds tested (toxopyrimidine, Na-pyrophosphate, choline, L-phenylalanine, ethyl-urethane and 5-fluorouracil), none had any inhibitory action on intestinal thiamine-pyrophosphokinase activity, even if used at concentrations hundred times higher than that of labelled thiamine.

Animals↗
PubMed1979

New aporphine alkaloids of Ocotea minarum.

Fourteen aporphine alkaloids were isolated from the leaves of a Brazilian Lauracea, Ocotea minarum Nees (Mez). The known alkaloids were identified through their physico-chemical properties as: leucoxylonine (VII), dicentrine (IV), ocoteine (V), leucoxine (VI), ocopodine (VIII), predicentrine (IX), dicentrinone (XIV) and thalicminine (XV). Six new aporphine alkaloids were also isolated: ocotominarine (I), ocominarine (III), nor-leucoxylonine (XI), iso-oconovine (xii), 4-hydroxydicentrine (XIII) and ocominarone (XVI). Their structures were determined using spectroscopic methods and chemical correlations.

Alkaloids↗
PubMed1979

Synthesis and chemical properties of N- and O-phosphorylated derivatives of creatinol.

N-Methyl-N-(beta-hydroxyethyl)-guanidine O-phosphate (creatinol O-phosphate) was synthesized from creatinol by phosphorylation with partially hydrolyzed phosphoryl chloride or by dehydration of its phosphate salt. Creatinol N-phosphate was obtained by addition of N-methylamino ethanol to bis-p-nitrobenzylphosphocyanamide, followed by hydrogenolysis. The chemical properties of both compounds were investigated; creatinol N-phosphate was rearranged to creatinol O-phosphate by heating.

Chemical Phenomena↗
PubMed1978

The action of inorganic phosphate on thiamin transport by rat everted jejunal sacs.

Rat everted jejunal sacs were incubated at 37 degree C in Krebs-Henseleit buffer, pH 7.4, containing thiazole-2- 14C-thiamine (0.2 micrometer), in the absence or in the presence of inorganic phosphate at a final concentration of 6mM. Control experiments under the same conditions, but without labeled thiamin were also carried out. In the intestinal sac wall, the content of labeled and endogenous (unlabeled) thiamin in the free and phosphorylated form was measured, while in the serosal fluid, total transported thiamin (labeled and endogenous) was evaluated. Accumulation in the enterocyte of inorganic phosphate, an inhibitor of thiamin pyrophosphate enzymatic hydrolysis, lowered the dephosphorylation of endogenous thiamin phosphates, both in the presence and in the absence of labeled thiamin. In the presence of labeled thiamin, the following results were observed: a) decreased labeled thiamin uptake and accumulation, both in the phosphorylated and free form; b) reduction of labeled thiamin transport to the serosal side; c) increase of endogenous thiamin exit from the intestinal cell. These findings seem to point out an important role of thiamin phosphorylation-dephosphorylation coupling in thiamin intestinal transport in vitro.

Animals↗
PubMed1978

[Amyotrophy caused by herpes zoster. Description of 5 cases].

Radicular paralysis is the most frequent, though usually less serious, complication of Herpes Zoster, being observed in rather less than 5% of patients. The site affected--leaving aside exceptional cases--it that of the gangliar and radicular district where the eruption occurs. A clinical and neurophysiological study was made of 5 patients with loss of strength and trophism on the part of muscles in the eruption site within 2 to 5 weeks after the onset of Herpes. Routine blood chemistry tests were run, together with spinal puncture in three cases. The EMG data pointed to variously severe neurogenic distress referable to myeloradicular involvement. Subsequent clinical and EMG controls demonstrated gradual, though slow improvement. This finding is in line with the literature data.

Adult↗
PubMed1978

Delayed cerebrovascular consequences of radiation to the neck. A clinicopathologic study of a case.

A man had a stroke 27 years after radiation therapy to the neck for treatment of laryngeal papillomas. There were premonitory symptoms suggesting cerebral ischemia. In contrast to many previously reported cases, in our patient there is a strong relationship between radiation therapy and stroke. Pathoanatomic study of the surgical vascular specimen strongly suggests that radiation is a potentially modifiable cause of delayed stroke.

Adult↗