Biomedical subjects
Publications and source records attributed to G Ferrari.
Surgical specimens of human gastrointestinal mucosa and mucosa and muscle were incubated in vitro with thiamine-thiazole-214 C. Labelled thiamine uptake was uphill in mucosal tissues and downhill in muscle. Small intestinal mucosa accumulated labelled thiamine in a phosphorylated form, while gastric and colonic mucosa, as well an muscular layers of all gastrointestinal segments studied, did not.
Sulfate uptake capacity and ATP-sulfurylase activity were determined in maize roots (Zea mays L. var. XL 363 and mutant XL 363 o2) at increasing root length. The pattern of uptake showed a close similarity to that of ATP-sulfurylase, both activities reaching the maximum level at 9 and 10 cm root length in the XL 363 and XL 363 o2 hybrids, respectively. In addition to the shift of the maximum, opaque-2 mutation caused an enhancement of the two activities at root length below and above the activity peak. The kinetic parameter of uptake, Km, showed a maximum at 3 to 4 and a minimum at 7 to 8 cm. The isoenzyme pattern of ATP-sulfurylase was the same in the two hybrids and did not change with root elongation. A common regulatory mechanism is postulated for uptake and activation of sulfate. The kinetic behavior is interpreted as an index of flexibility of the transport system toward different nutrient status of the environment.
Aporphine, proaporphine and morphinane alkaloids were isolated from the leaves of a Brazilian Lauracea, Ocotea brachybotra (Meiss.) Mez. The known alkaloids were identified through their physico-chemical properties as: (I) (+/-)-glaziovine, (II) dicentrine, (III) ocopodine, (IV) cassynthicine, (V) predicentrine, (VI) leucoxine, (IX) sinacutine and (X) pallidine. The structure of (VI) leucoxine was confirmed by a detailed analysis of the N.M.R. spectra recorded in various conditions. New morphinane alkaloids, (XI) ocobotrine and (XII) 14-espisinomenine, having the unusual B/C-trans configuration were also isolated. Their structures were determined using spectroscopic methods and chemical correlations.
An immunochemical method for the quantitative determination of D and E fibrinogen degradation products has been studied; the use of a new type of agarose-gel is suggested, in order to obtain a sensitivity in the nanograms range.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Blood pyruvate and free and phosphorylated thiamin contents of liver and brain were measured in pigeons during diatary thiamin deficiency. Neurologic signs (opisthotonus and ataxia) appeared in the course of thiamin deficiency or did not appear at all during the entire athiaminosis period. As compared to respective controls, which never exhibited any neurologic abnormalities in spite of thiamin deficiency, the symptomatic animals had a higher pyruvate level in blood and a significantly lower phosphorylated thiamin content in both liver and brain. A hypothesis on relationship between phosphorylated thiamin content of liver and brain and occurence of nervous symptoms was expressed.
The characteristics of the extracellular and cellular calcium exchange in taenia coli have been studied by efflux experiments under different experimental conditions. The exchange of extracellularly bound calcium is accelerated by the presence of calcium in the external solution. If a Ca-free solution is used as washing solution, the slowly exchanging extracellular calcium also contributes appreciably to the later phase of the Ca efflux and obscures the changes of the cellular calcium exchange. There is no evidence for a Ca-Ca exchange diffusion. Most of the 45Ca bound at extracellular binding sites can be released by a 10 min exposure to 2 mM EGTA or to 10 mM La3+. This La concentration moreover largely inhibits the release of 45Ca from the cellular compartment by metabolic depletion. A release of cellular 45Ca can be induced by metabolic depletion or by K depolarization. Both procedures probably act at the same sequestering sites. However, while DNP + IAAa cts in the absence of external Ca, it is observed that K depolarization can only cause a Ca release if external Ca can enter the cells.
Explore the source record for details and available documents.
Labeled and unlabeled (endogenous) free and phosphorylated thiamine were measured in isolated everted rings of rat jejunum in vitro during short incubation periods (1-10min). Shortly after the addition of thiamine-14C to the incubation medium, the intracellular specific activity of the free form was higher than the specific activity of the phosphorylated fraction. In the course of time this difference diminished and finally the two specific activities became equal. The conclusion was reached that free thiamine is the likely precursor of intracellular phosphorylated thiamine. Moreover evidence is presented which indicates that free thiamine entered actively into intestinal epithelial cells. Since free thiamine was modified into phosphorylated form inside the cells, its movement against the endocellular concentration gradient was noticeably favoured.
Explore the source record for details and available documents.
Inhibition by cycloheximide of sulfate transport in both barley roots (Hordeum vulgare L.) and potato tuber (Solanum tuberosum L.) increases with increasing inhibitor concentration only to a limited extent, depending on the length of the tissue incubation with the inhibitor. In contrast to this, increasing concentrations of dinitrophenol have a rapid and total inhibitory effect on the active transport. Leucine transport in the same tissues is strongly inhibited by dinitrophenol but is not affected by cycloheximide, whereas incorporation into protein is mainly inhibited by cycloheximide. It appears that the mechanism of transport inhibition by cycloheximide in plant tissues consists in stopping new carrier synthesis and not in the disruption of energy flow. Sulfate carriers show comparable decay rates in barley roots and potato tuber, the mean life being shorter than that of the leucine carriers. These appear more stable in roots than in storage tissues.
Explore the source record for details and available documents.
Report of one case of atypical osteo-chondrodysplasia, which was classified as a thanatophoric dwarfism, with neuropathological examination of the brain. Microgyria and cytological changes were in the ectocinerea. Too heterotypies in the neuronal place were observed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.