Biomedical subjects
Publications and source records attributed to P Bruni.
A case of spinal subarachnoid hemorrhage from a cavernous angioma of the cauda equina is reported. The patient was a 28-year-old man who complained of a sudden low-back pain and neck stiffness. Laminectomy at L1-L2 was performed with total removal of the tumor.
We present a patient whose radicular syndrome resulted from combined compression by disk herniation and lumbar chronic spinal epidural hematoma (CSEH). The lesion was extensively studied by CT and MRI and the preoperative diagnosis confirmed by microscopic examination. CSEH is a rare entity, typical of elderly and invariably involving the lumbar canal: only 11 similar cases have been reported up to date. We propose that an undefined number of CSEH remains clinically silent, hidden in the roomy lumbar canal, displacing but not injuring the roots of the cauda. The routine use of Gd-DTPA MRI, even in emergency, will significantly decrease mistakes localization and will provide the correct differential diagnosis.
The case is described of a woman with drug hepatotoxicity, who was a psychiatric patient. The case is reported because the diagnosis occurred by a "praecoxfeeling", in fact physician's intuition is a personal structure which is born from same external incitements instead of other. The diagnosis was confirmed by clinical tests and by subsequent clinical research.
A case of post-traumatic cruciate paralysis with a Jefferson's fracture was observed in a 54-year-old patient who fell accidentally. Cruciate or Bell's paralysis is a condition caused by incomplete cervical spinal cord lesion linked to focal and reversible damage of the pyramidal tract at the level of the decussation. The patient was treated by S.O.M.I. brace and a Philadelphia collar with a complete neurological restitution.
In this work the idea of praecox gefüll or praecox feeling is resumed by H. C. Rumke in 1941 and by Minkowski in 1968 for patient with schizophrenia. The diagnosis is not done only by patient's examination and by symptoms, but also by diligent examination which the psychiatry does about himself. To perceive one and to diagnose by praecox feeling is a personal ability, but it is a training with ourselves: to be sensible of the "effect" of disease in us. The praecox feeling, attributed in psychiatry, may be expanded in other medical areas. Case report gives evidence about this.
Exogenous glutamine was metabolized by platelets to glutamate, aspartate, and CO2; whereas no lactate was formed. The amount of aspartate and CO2 produced from glutamine was reduced by the presence of glucose. On the other hand the rate of oxidation of glucose was reduced by the presence of glutamine. The potential energetic value of glutamine was lower than that of glucose, but the amino acid appeared to be a preferential respiratory substrate. The energy provision from glutamine also plays a role in the process of platelet activation, known to require an extra supply of ATP, since thrombin increased the rate of glutamine utilization in platelets. Upon cell activation an increase in aspartate and CO2 formation was observed and the stimulatory effect on glutamine oxidation by thrombin was also maintained in the presence of glucose.
Fructose 2,6-bisphosphate (Fru-2,6-P2) content in human fibroblasts is under hormonal control and is strictly related to glycolytic flux. In the present study it has been examined whether aging process is accompanied with an impairment in the control exerted by insulin on the metabolite content. Upon insulin stimulation old fibroblasts show a reduced increase in Fru-2,6-P2 content and glycolytic flux. Similarly, 6-phosphofructo-2-kinase (PFK-2) activity in old fibroblasts is increased at a lesser extent by insulin treatment, suggesting that an impairment at post-receptor level in the signalling pathway of insulin might occur with aging. In addition in unstimulated senescent fibroblasts PFK-2 displays higher activity and reduced Km for substrate, suggesting either that during senescence PFK-2 undergoes a post-translational modification or that a different PFK-2 isoenzyme is expressed.
The involvement of the glycosylphosphatidylinositol/inositol phosphoglycan (gly-PtdIns/IPG) system in the stimulation of macromolecular syntheses in human fibroblasts has been investigated. The study demonstrates that an insulin sensitive gly-PtdIns/IPG system is present in human fibroblasts, that IPG can significantly stimulate DNA, RNA, and protein synthesis, and that the action of insulin on DNA synthesis as well as that of IPG can be significantly reduced by a specific anti-IPG antibody. These results strongly support the hypothesis that the gly-PtdIns/IPG system is involved in the signal transduction pathway leading to the stimulation of cell proliferation.
Upon hydrolysis of membrane glycosyl-phosphatidylinositol (gly-PtdIns), an inositol phosphoglycan (IPG) is generated, responsible for multiple biological activities and recently proposed as mediator of the action of a variety of hormones and growth factors. The present study shows that IPG is able to significantly stimulate platelet glycolysis, which represents the major energy producing pathway in this cell system. The activation of glycolytic flux induced by IPG appears to be specific and very rapid even though the molecular mechanism involved remains to be elucidated.
The authors report a case of spinal subarachnoid hemorrhage caused by neurofibromas of the cauda equina. An examination of the literature revealing 13 similar cases and an analysis of this case showing three neurofibromas of the cauda equina prompted an hypothesis emphasizing the origin of bleeding and the difficulties associated with a correct diagnosis.
We measured protein kinase C (PKC) activity in normal and ras-transformed Balb/3T3 fibroblasts; cytosolic and nuclear-associated PKC activity was determined either as phorbol ester binding, PKC-dependent phosphorylation of histone III-S, or phosphorylation of endogenous nuclear proteins. Results demonstrate that ras-transformed fibroblasts show down-regulation of cytosolic PKC accompanied by increase of nuclear-associated PKC. These results provide evidence linking transformation to PKC nuclear shift with consequent phosphorylation of nuclear proteins.
It has been recently demonstrated that insulin promotes the hydrolysis of a glycosyl-phosphatidylinositol, stimulating the release of a phospho-oligosaccharide which displays several insulin-like effects. In the present study we have investigated whether the compound is able to mimic insulin action on glucose metabolism in human fibroblasts. Similarly to the hormone, the phospho-oligosaccharide elicited a dose dependent increase in lactate output and fructose 2,6-bisphosphate content. The effect of the compound was time dependent with a progressive increase starting from 2 hours of incubation. 1 microM phospho-oligosaccharide had half maximal effect on both parameters, increasing glycolytic flux by approximately 30% and fructose 2,6-bisphosphate content by 70%. Therefore the phospho-oligosaccharide appears to be able to strictly reproduce insulin action on glucose metabolism in human fibroblasts.
We measured the synthesis of diacylglycerol de novo in normal NIH/3T3 fibroblasts and in cells transformed by ras, src, sis and abl oncogenes. Analysis of the incorporation of glucose-derived 14C into diacylglycerol indicated that neosynthesis of diacylglycerol was constitutively active in the transformed cell lines. Elevated levels of diacylglycerol and persistent activation/down-regulation of protein kinase C reduced the binding of phorbol dibutyrate to transformed cells. This phenomenon could be reversed by blocking the glycolytic pathway, thus indicating that neosynthesized diacylglycerol was responsible for persistent activation and down-regulation of protein kinase C. In transformed cells, protein kinase C activity could not be stimulated by the addition of diolein; however, inhibition of glycolysis restored the ability of transformed cells to respond to diolein. Taken together these data indicate that constitutive synthesis of diacylglycerol de novo is responsible for activation and down-regulation of protein kinase C in transformed cells, and it may play a role in altered mitogenic signalling.
The stimulation of human platelets with thrombin results in a rapid and sustained increase in the fructose 2,6-bisphosphate content which may play an important role in the potentiation of glycolytic flux induced by the agonist. The investigation of the effect of pH on thrombin-induced rise in platelet fructose 2,6-bisphosphate content is reported here. The results indicate that the early intracellular alkalinization which follows platelet stimulation may contribute to mediate the positive effect of thrombin on the regulatory metabolite.
An endpoint enzymatic assay for fructose 2,6-bisphosphate based on the ability of the compound to stimulate pyrophosphate 6-phosphofructo-1-kinase and performed in a 96-well plate is reported here. The method presents a low detection limit and a high sensitivity that could be further improved; moreover, the use of 96-well plates greatly increases the number of samples that can be simultaneously assayed.
1. Insulin is able to stimulate lactate production and to enhance fructose 2,6-bisphosphate (Fru-2,6-P2) content in 3T3-L1 adipocytes. 2. Phorbol 12-myristate 13-acetate is more efficacious than insulin in rising Fru-2,6-P2 content and less effective in the stimulation of glycolysis. 3. 3T3-L1 adipocyte 6-phosphofructo-l-kinase appears to be very sensitive to exogenous Fru-2,6-P2. 4. Insulin treatment does not affect the maximum activity of 6-phosphofructo-1-kinase whereas it markedly increases the affinity of pyruvate kinase for phosphoenolpyruvate. 5. The role of Fru-2,6-P2 in the insulin induced enhancement of glycolytic flux is discussed.
Ten cases of intracranial meningiomas in patient who differed by age, sex and histological characteristics of the lesion have been considered for the purpose of evaluating the lesion's receptor capacity and the changes in it with the above variations. Receptors were found and they varied with age and histological features.
536 meningioma cases were examined in order to assess incidence in terms of sex age, site and recurrences and to discover whether recurrence was related to the site, dimensions or histological features of the tumour. The data obtained indicate that in order to assess the biological behaviour of meningiomas, their histological features, accessibility and dimensions must be borne in mind. In fact benign tumours quickly recur if they are large or inaccessible. In contrast long-term recurrences are probably due to the presence of included cells as reported in the literature.