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Biomedical subjects

R Di Primio

Publications and source records attributed to R Di Primio.

At least 55 records · Page 3Linked to original sources
PubMed1981

[Lymphocyte populations and cerebrospinal fluid immunoglobulins in patients with polyradiculoneuritis. I].

We have studied four patients affected by poliradicoloneuro inflammation with rosette test ET - Ea and EAChu and with the dose of Ig cerebral fluid. The results of these experiments seems interesting in furnishing elements indicative of the immunological status of each patients. In fact, one can observe a significant increase of rosette Ea as a possible reaction or intervention of this subpopulation of T engaged in the immunitary response. We observed further that an increase of Ig neuro-fluid and, in particular, of IgG, could strengthen the idea of a probable humoral immunitary moviment as a result of poliradiconeuro inflammation.

Adolescent↗
PubMed1981

[Findings of the importance of dietetic fiber in the regulation of cholesterolemia].

We studied the variations of some lipid indexes in cholesterolemia, lipidemia and triglycerides in relation to a diet rich in bulk. Seven adult male subjects in good health were tested for cholesterol, lipid and triglycerides before and after a two week period of a dialy diet of 40 g of whole wheat bran containing about 10g of fiber. At the some time the lipid, cholesterol and triglycerides limits were measured in 3 groups of rabbits. The first groups was subjected to a normal diet, the second group was subjected to a diet of bleached flour and vitamins, and the third group had a diet similar to the second group but with the addition of 40 g whole wheat bran. The results of our investigation demonstrated a statistically significant decrease of cholesterol lipid and triglycerides levels the special diets at the some time we did not see in increase in the third group of rabbit. Our study seems to indicate that dietetic fibers exercise a vital role in regulating the concentration of plasma lipids even if the subject continues to consume a diet rich in fats. From this we see to importance of the dietetic fibers as a protective factor in the prevention of ateriosclerotic.

Adult↗
PubMed1981

[T-lymphocyte subpopulations in old age].

The subpopulation of lymphocytes were studied in 25 subjects old age and in 20 adult subjects as control. The results demonstrate an appreciable difference in the percentage of rosettes values at +4 degrees C for 18 hours between the old age subjects (mean value 83,5%) and the control subjects (mean value 66,2%). It is difficult to interpret these variations but it is possible that there is a different distribution on the cell membrane of lymphocyte T for the receptors for SRBC. The probable relation ship with variations of the citoskeleton and more specifically the distribution of the "Tubuline".

Adult↗
PubMed1981

[HDL-cholesterol as an indicator of atherogenic risk in healthy women of advanced age].

We wanted to study HDL cholesterol in female subjects in good health but of in advanced age without a history of cardiac-vascular problems. The result show an increase in value for total cholesterol in only 2 subjects out of a total of 39 subjects studied and we saw a triglycerides increase in only 7 subjects. The HDL cholesterol was found high in 13 subjects and inferior to 55 mg/dl of serum in 26 subjects which also demonstrated low values of total cholesterol. In fact, the arteriosclerotic risk factor calculated using the method of Castelli e Cell increased only in 2 subjects demonstrating that the lack of clinical manifestation in accompanied by a decrease in the ateriosclerotic "risk factor".

Aged↗
PubMed1981

[Effects of a "single-meal" low calorie diet on the circadian variation of serum cortisol, insulin and somatotropin and urinary excretion of catecholamines].

Four obese patients were given a single-meal diet for two periods of three days each. Blood samples were drawn every four hours for serum determinations of growthormone, cortisol and insulin. At same times urinary samples for urinary cathecholamines determination were collected. Cortisolemia showed a firm circadian rhythm in both regimens: there was a marked over-lap of the two confidences ellipsis so we could conclude for the independence of cortisol rhythm whith both regimes, but there occurred a significant difference in the acrofases between the two regimens. This could mean that meal-timing can play a major role in syncronizing catecholamines urinary excretion as far as subjects in supine position are concerned. No circadian rhythm was detected either in serum insulin or in HGH values.

Catecholamines↗
PubMed1981

Longitudinal study of clinical, neurophysiological and immunological parameters in multiple sclerosis. Preliminary investigation.

Thirty subjects affected with multiple sclerosis, of which 22 were female and eight male, with an average of 30 +/- 7, years were studied, for a period of 10-15 months,. clinically using Kurtzkes' report form, neurophysiologically (responses tested: VEP, BAEP, SEP, ESG) and immunologically (Rosette Et, Ea, EAC). Of the 30 cases, 19 showed poussées in the last three years and 11 were in the stabilization phase. The Kurtzke reports and the neurophysiological tests permitted an accurate assessment of lesion levels and their rate of evolution. The immunological tests showed a notable ability to differentiate between subjects with recent poussées and those in the stabilization phase presenting overall values significantly below the norm. In the follow-up, after treatments with methisoprinol, the immunological tests also revealed modifications of notable interest.

Adult↗
PubMedDate not supplied

The c-myc gene regulates the polyamine pathway in DMSO-induced apoptosis.

It is accepted that apoptosis is a gene-controlled process of cellular self-destruction. It occurs during physiological regulation and in pathological situations in the life of a cell. In the immune system, several different intracellular and extracellular factors have been associated with the induction of apoptosis, and the final responses depend on the cell system and the acquired signals. In lymphoid cells, dexamethasone-induced apoptosis is associated with c-myc downregulation in cells that remain in G0-G1 until the point of death. Ornithine decarboxylase (ODC), a key enzyme involved in polyamine biosynthesis, is regulated by c-myc, which is a transcriptional activator implicated not only in the control of cell proliferation and differentiation but also in programmed cell death. As dimethylsulphoxide (DMSO) induces apoptosis in the RPMI-8402 human pre-T cell line, the present study analysed the involvement of the c-myc proto-oncogene and polyamine pathway as mediators of apoptosis. Cell growth, programmed cell death, c-myc expression, ODC activity and intracellular polyamine content were detected after DMSO and difluoromethylornithine (DFMO) treatment. DMSO-treated cells exhibit a decrease in ODC activity and polyamine levels associated with cell growth arrest and programmed cell death induction. The expression of c-myc proto-oncogene, as its mRNA or protein, is specifically down-regulated. DFMO, a well defined polyamine biosynthesis inhibitor, completely blocks ODC activity, resulting in growth inhibition but not apoptosis. Moreover, in these samples no evidence of changes of c-myc expression were found. The results obtained suggest that, in RPMI-8402 cells, DMSO provokes a c-myc-dependent decrease of ODC activity followed by a depletion of intracellular polyamine levels, associated with programmed cell death and cell growth arrest.

Apoptosis↗
PubMedDate not supplied

DMSO modifies structural and functional properties of RPMI-8402 cells by promoting programmed cell death.

Apoptosis in lymphoid cells can be induced in different ways depending on cell type and acquired signal. Biochemical modifications occur at an early phase of cell death while at late times the typical morphological features of apoptosis can be visualized. The aim of this study is to verify by multiparametric analyses the plasma membrane fluidity, the intracellular Ca2+ concentration and the nitric oxide synthase (NOS) activity during cell death progression induced by DMSO treatment. The RPMI-8402 human pre-T lymphoblastoid cell line was induced to cell death by DMSO. Analyses rescued at early times of treatment prove a substantial modification of plasma membrane fluidity associated with an increase of intracellular Ca2+. Moreover, these modifications are associated with an up regulation of NOS activity. Our results are consistent with the hypothesis that programmed cell death can be induced by up regulation of the intracellular Ca2+ associated with an increase of cell membrane fluidity. The apoptotic mechanisms seem to involve not only membrane damage and increased intracellular calcium levels but also production of nitric oxide.

Apoptosis↗
PubMedDate not supplied

Sphingolipid microdomains mediate CD38 internalization: topography of the endocytosis.

Plasma membranes of several cell types contain specialized microdomains (or lipid rafts) enriched in sphingolipids, cholesterol, sphingomyelin, and glycosyl-phosphatidylinositol-anchored proteins. These membrane domains are characterized by detergent insolubility at low temperatures and low buoyant density. Human CD38 is the prototype of a gene family encoding surface molecules endowed with multiple functional activities. The endocytosis of the human CD38 molecule has been investigated in normal lymphocytes and in a number of leukemia- and lymphoma-derived cell lines demonstrating that internalization after CD38 ligation is a reproducible event involving only a fraction of the whole amount of the surface molecule. This study reports the results obtained by conventional, confocal, and electron microscopy on the effects induced by the engagement of the molecule with agonistic mAb, reproducing the signals mediated by its natural ligand. The results demonstrate that the endocytosis induced as consequence of CD38 ligation is preceded by a thorough rearrangement of the cell surface with formation of glycosphingolipid- and cholesterol-rich plasma membrane microdomains. These data suggest that specialized raft microdomains might be the plasma membrane structure through which CD38 translocates at intracellular level. The CD38/lipid interactions during the coated pit formation trigger a process that generate membrane curvature, considered as the first step of CD38 endocytosis. Moreover, ultrastructural studies show that early CD38(+) endosomes are pleiomorphic and contain cisternal and vesicular regions. Late endosomes exhibit a complex organisation, containing uncoupled CD38-ligand multivesicular- or multilamellar-regions.

ADP-ribosyl Cyclase↗
PubMedDate not supplied

Morphological and cytofluorimetric analysis of adult mesenchymal stem cells expanded ex vivo from periodontal ligament.

Many adult tissues contain a population of stem cells that have the ability of regeneration after trauma, disease or aging. Recently, there has been great interest in mesenchymal stem cells and their roles in maintaining the physiological structure of tissues, and their studies have been considered very important and intriguing, after having shown that this cell population can be expanded ex vivo to regenerate tissues not only of the mesenchymal lineage, such as intervertebral disc cartilage, bone, tooth-associated tissue, cardiomyocytes, but also to differentiate into cells derived from other embryonic layers, including neurons. Currently, different efforts have been focused on the identification of odontogenic progenitors from oral tissues. In this study we isolated and characterized a population of homogeneous human mesenchymal stem cells proliferating in culture with an attached well-spread morphology derived from periodontal ligament, a tissue of ectomesenchymal origin, with the ability to form a specialized joint between alveolar bone and tooth. The adherent cells were harvested and expanded ex vivo under specific conditions and analysed by FACScan flow cytometer and morphological analysis was carried out by light, scanning and transmission electron microscopy. Our results displayed highly evident cells with a fibroblast-like morphology and a secretory apparatus, probably indicating that the enhanced function of the secretory apparatus of the mesenchymal stem cells may be associated with the secretion of molecules that are required to survive and proliferate. Moreover, the presence in periodontal ligament of CD90, CD29, CD44,CD166, CD 105, CD13 positive cells, antigens that are also identified as stromal precursors of the bone marrow, indicate that the periodontal ligament may turn out to be a new efficient source of the cells with intrinsic capacity to self-renewal, high ability to proliferate and differentiate, that can be utilized for a new approach to regenerative medicine and tissue engineering.

Adult↗
PubMedDate not supplied

Programmed cell death of peripheral myeloid precursor cells in Down patients: effect of zinc therapy.

Hemopoietic stem cell differentiation represents the primary rule of self-renewal, proliferation, and specialization modulated by several mechanisms, including growth factors, cell interactions, and bioavailability of various ions, especially Ca2+ and Zn2+. Apoptotic death, during normal cell turnover, has been widely studied and is recognized as an important pathway for clonal deletion in the hemopoietic system. Multiparametric analyses have shown that subjects with Down syndrome show low levels of plasmic zinc associated with the presence of immature myeloid cells in the peripheral blood. This arrangement is repaired by in vivo zinc therapy. This study presents morphological and biochemical analyses to show that ZnSO4 therapy induces the disappearance of peripheral myeloid precursor cells by a programmed cell death mechanism. The programmed zinc-therapy-induced cell death presumably provides a simple way to regulate the myeloid differentiation selecting appropriate cells.

Adolescent↗
PubMedDate not supplied

TCR and immunophenotype changes in dimethyl sulfoxide-dependent programmed cell death.

In the thymus most deleted cells are immature thymocytes and the high rate of cell death within the thymus is involved in the development of the initial T-cell receptor repertoire. Functional T-cell receptor recognition units are created by somatic rearrangements of gene segments, and the expression of successfully assembled TCR complex is the key to molecular events that culminate in T-cell activation, growth and differentiation. Previously, we reported that DMSO induces apoptosis in RPMI-8402 human pre-T cells. Here we examine the fate of pre-T cells undergoing negative selection analysing the responsiveness to DMSO-enforced TCR expression and immunophenotype modulation. Our results demonstrate that DMSO induces cell growth inhibition, cell phenotype changes, with down-regulation of CD2 and CD7, and increases in alpha/beta or gamma/delta TCR chains led by TdT, RAG-1 and RAG-2 activity. These modifications are associated with an apoptotic program. Taken together, these data suggest the existence of an early checkpoint that ensures in vivo the effective intrathymic differentiation supported from another point of view, the linkage between immunophenotypes and TCR regulation in T-cell differentiation and programmed cell death.

Antigens, CD↗