Platelet subpopulations in adult and geriatric males.

In this study, the authors wanted to investigate the volume, density, and percentage of three platelet subpopulations present in adult and geriatric males. Ninety subjects, between the ages of 20 and 40, were chosen for the adult group and 50 subjects, all older than age 70, were used for the geriatric group. The platelet subpopulations were separated with discontinuous gradients of Percoll. The results obtained from the three platelet subpopulations--low, intermediate, and high density--show different volumes and percentages in both the groups studied. From the information that larger platelets can be expected to have a longer life span, it was possible to hypothesize that platelets found in geriatric males have a reduced average life span. It is also clear that platelets exist that have similar volumes but different densities.

Fluvastatin reduces soluble P-selectin and ICAM-1 levels in hypercholesterolemic patients: role of nitric oxide.

BACKGROUND: Lipid-lowering therapy with 3-hydroxy-3-methylglutaryl-coenzymeA (HMG-CoA) reductase inhibitors reduces the incidence of atherosclerosis-related cardiovascular events. Adhesion molecules, regulating interactions between vascular and circulating cells, may play a central role in the pathogenesis of atherosclerosis and related complications. In the present report we examined the impact of the HMG-CoA reductase inhibitor fluvastatin on plasma levels of P-selectin and ICAM-1. METHODS: Plasma levels of P-selectin and ICAM-1 were determined using an enzyme immunoassay in 26 patients with type IIa hypercholesterolemia randomized to treatment with either fluvastatin (80 mg/d) or placebo in a double blind fashion for 12 weeks. RESULTS: Fluvastatin administration reduced either P-selectin (118 +/- 63 vs 81 +/- 36 ng/mL [-31%], P = 0.0015) or ICAM-1 (264 +/- 75 vs 228 +/- 68 ng/mL [-13.7%], P = 0.0033) levels. Fluvastatin also lowered urinary 11-dehydro-TXB2 (1396 +/- 536 vs 1009 +/- 378 pg/mg creatinine [-27%], P = 0.0015) and von Willebrand Factor levels (1456 +/- 716 vs 1203 +/- 527 U/L [-17.4%], P = 0.0275), and a direct correlation was observed between P-selectin and 11-dehydro-TXB2 levels (r = 0.588, P = 0.0033). Patients treated with fluvastatin displayed an increase in nitric oxide (NO) generation, evaluated with measurements of serum NO2-/NO3-, (4.7 +/- 1 vs 8.9 +/- 3.1) mumol/L [98%], P = 0.0046). Moreover, an inverse correlation was observed between NO2-/NO3- and P-selectin (r = -0.420; P = 0.0343), 11-dehydro-TXB2 (r = -0.511; P = 0.0106), or LDL (r = -0.742; P = 0.0002) levels. CONCLUSIONS: These results may provide novel biochemical basis for the beneficial clinical effects of HMG-CoA reductase inhibitors in hypercholesterolemia.

Environmental stress on diving-induced platelet activation.

Platelet activation has been suggested to play an important role in the pathogenesis of prethrombotic states and thus may be responsible for decompression illness during compressed air (scuba) diving. To investigate the effect of physical, mental, and environmental stress on platelet activation during immersion in ice-cold water, we examined 10 male breath-hold divers (BHD), 10 elite BHD (eBHD), and 10 scuba divers during immersion in an ice-covered lake at moderate altitude. Platelet activation was examined by surface expression of activation-dependent glycoproteins CD62p, CD63, and CD42a with flow cytometry 10 min before and 1 min and again 24 h after diving. Plasma epinephrine level was also measured. In addition, the relationship between the activated platelets and the epinephrine level was evaluated. The percentage of platelet activation increased from 2.1 +/- 0.4 to 5.7 +/- 0.3, 1.8 +/- 0.3 to 12.9 +/- 0.8, and 3.7 +/- 0.9 to 31.2 +/- 0.8 in BHD, eBHD, and scuba divers, respectively. The percentage of platelet activation returned to pre-immersion levels in BHD and eBHD divers 24 h after diving, but was still higher in scuba divers. A positive relationship exists between the plasma epinephrine level and the percentage of the platelet activation. This study suggests that physical and mental stress enhance platelet activation during diving in ice-cold water.

[Collagen-induced platelet aggregation in K562 neoplastic cells culture media]. / L'aggregazione piastrinica indotta da collagene in presenza di terreno di coltura di cellule neoplastiche K562.

The evidence suggests that the propagation of neoplastic cells by solid tumors, seem the platelets have a protective role on the neoplastic cells respect to immunocompetent system. In this study, the AA. valued the variation of platelet aggregation induced by collagen when PRP was incubated with liquid culture of neoplastic cells K562. The preliminary results, show the platelet aggregation induced by collagen, increase alter interaction with this liquid culture.

[Thea value and limits to kinetic analysis of human serum Ig. Preliminary note]. / Valore e limiti dell'analisi cinetica delie Ig sieriche umane. Nota preliminare.

We have considered accuracy and sensitivity of a new kinetic method called "Fixed time", in order to determine human Ig. The method based on velocity of the reaction, considers the increase in turbidness, which is due to immune-complex formation during a constant and predetermined period of time from the start of the reaction to when equilibrium is achieved. Experience with testing times demonstrates that the best results were obtained by introducing a variant to the method adopted up to now. According to that method, velocity reaction was usually estimated in a period of time comprised between the 1st and the 6th minute, while turbidness is now estimated after 15" (first time) and after 3'15" (final time) from the beginning of the reaction.

[Relation between vitamin A and the fragility of red blood cells subjected to continuous mechanical trauma]. / Correlazioni tra vitamina A e fragilita' dei globuli rossi sottoposti a trauma meccanico continuo.

Is well-known the haemolitic action that A-vitamine exerts on the erythrocytes. With our study we have submitted the erythrocytes, of forty normal subjects, to incubation to 37 degrees C and to constant traumatic action with and without A-vitamine. After we have dosed the haemoglobin and potassium in the plasma to various times of incubation and traumatic action. The results demonstrate that this vitamine determines an increase of the fragility of the erythrocytes beyond the 100% after 120 minutes, while protects the membrane of erythrocytes to the release of potassium.

[Comparison between paracoagulation tests in chronic liver disease]. / Studio comparativo fra alcuni tests di paracoagulazione nelle epatopatie croniche.

We have used three tests of paracoagulation in patients with chronic liver diseases: ethanol test, protamine sulfate test and agglutination test. The best results were obtained with agglutination test specially in liver cirrhosis.

[Separation and purification of IgE and IgM by chromatographic techniques for diagnostic serology]. / Separazione e purificazione di IgE e IgM mediante tecniche cromatografiche per la diagnostica sierologica.

We describe the performance of a gel filtration technique using Sephadex G-200 and a ion exchange chromatographic separation using DEAE-cellulose. These methods are able to fractionate quickly and easily IgG and IgM as applied in diagnostic serology.

[Total lactate dehydrogenase content and its isoenzymes in a human platelet subpopulation]. / Contenuto in latticodeidrogenasi (LDH) totale e suoi isoenzimi nelle sottopopolazioni piastriniche umane.

The morphological and functional variability of the platelets is on the way of the study. The morphological platelet transformations corresponding to functional attitudes, need of energetic pattern given by the content, in platelets, of enzymatic patrimony. The results show that the lactic-dehydrogenase and isoenzymes, content in the three studied platelet subpopulations, is different. These significant data, probably show that the platelet subpopulations have a different content in total LDH while show no modification in LDH isoenzymes as show in various functional and energetic different specific point in time.

[The influence exercised by various temperatures on platelet aggregation in vitro]. / Studio sull'influenza esercitata dalle diverse temperature sull'aggregabilità piastrinica "in vitro".

To obtain a regular haemostasis is necessary that the platelets are numerically sufficient and functionally normal. Many factors influence on platelet aggregation; among these platelet shape, dimensions and volume. In our study we have analysed the temperature influence on platelet aggregation. In a group of 27 subjects we have demonstrated that the platelet rich plasma pre-incubation for 30 minutes in ice-bath does not modify the platelet aggregation capacity. On the contrary, the platelet rich plasma pre-incubation for 30 minutes at 37 degrees C reduces considerably the platelet aggregation, probably for the platelet volume reduction.

[T-lymphocyte subpopulations in old age]. / Studio della sottopopolazine linfocitaria T nell'anziano.

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".

[HDL-cholesterol as an indicator of atherogenic risk in healthy women of advanced age]. / HDL-colesterolo quale indice di rischio aterogeno in donne sane di eta avanzata.

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".

[Effects of dihydrostreptomycin and gentamycin on platelet membrane Na+-K+ATPase]. / Azione della diidrostreptomicina e della gentamicina sulla Na+-K+ATPasi di membrana piastrinica.

The use of aminoglycosides is characterised by a bound linkage between therapeutic and toxical levels. The aim of our study was to define the influence of diidrostreptomicin and gentamicin over Na+-K+ATPase of membranes of platelets. In this study, Bounting's and Caravaggio's method has been used, while ATPase activity was expressed in n mol of hydrolized ATP/min/mg of proteins. The data so obtained showed that the antibiotics were able to block up ATPase activity.

[Effects of aminoglycosides on T and B lymphocyte populations: in vitro study]. / Effetti degli aminoglicosidi sulle popolazioni linfocitarie T e B: studio "in vitro".

The authors tested the influence of gentamycin, spectinomycin,and dihydrostreptomycin on the formation of EAChu and EAT rosettes and they have found a significant reduction of the percentage of EAChu rosettes. Probably this reduction is due to an interaction with the receptor sites for the Complement of B lymphocytes and/or an in vitro denaturation Complement.

[Correlations between dietetic fiber and serum levels of total cholesterol and HDL-cholesterol]. / Correlazioni tra fibre dietetiche e livelli sierici di colesterolo totale e di hdl-colesterolo.

We have studied 10 male subjects, in good health to look for a probable correlation between dietetic fibre and serum concentration of total cholesterol, cholesterol-HDL and triglycerides. The dosages have been made before and immediately after that the subjects had assumed, with a diet, during 13 weeks, 10 g for day of dietetic fibre. The results show a significative statistical decrease and increase. Show a significative statistical decrease (p less than 0,025) of total cholesterol and that in agreement with the literature, and an increase (p less than 0,0125) of cholesterol-HDL. Consequently it's possible to affirm that the dietetic fibre has an antiatherogenic capacity.

[Study of T-lymphocyte subpopulations through monoclonal antibodies]. / Studio delle sottopopolazioni linfocitarie T mediante l'impiego di anticorpi monoclonali.

We studied the lymphocyte subpopulations T4+ and T8+ through monoclonal antibodies (McAb). The end of our study was focused in understanding the differences between the values mentioned by the literature and, consequently, determining our range of normality. Thus, we determined the subpopulations T4 and T8 using the antibodies OKT4 IND and OKT8 SUP, which define respectively the subpopulations T helper and T suppressor. Such determinations have been fulfilled whether on the total lymphocytes or on the lymphocytes T purified. Of course, the results obtained are different if we use the total lymphocytes or lymphocytes T purified. This confirms our suspect that the different values mentioned by the literature are determined by the two possible methods: T purified or total lymphocytes. In order to avoid interpretative mistakes, we suggest to express the values of T4+ and T8+ through the relation T4/T8; in fact, studying the single values obtained by the two different methods we proved they are different, but, at the same time, the relation T4/T8 remain unchanged in each method and is included in a "range of normality" from 1,4 to 1,7.

[Circadian rhythm of platelet aggregation induced by adrenaline and collagen in man]. / Variazione circadiana dell'aggegazione piastrinica indotta da adrenalina e collagene nell'uomo.

In five, healthy, male subjects the circadian variation of adrenaline and collagen induced platelets aggregation has been studied. Blood samples were carried out every four hours for a 24 hours period, platelets aggregation was evaluated on the P.P.P. by Elvi-Logos aggregometer adding adrenaline (1 mM/ml) or collagen (80 mg/ml). Cosinor test was used to detect circadian rhythms. A statistically significant circadian rhythm with peak in the morning has been demonstrated using both collagen or adrenaline. It is concluded that the adrenaline and collagen induced platelets aggregation "in vitro" shows a maximum of activity in the morning.