Search PubMed⌕ Search

Biomedical subjects

A Saitta

Publications and source records attributed to A Saitta.

At least 73 records · Page 4Linked to original sources

Passive immunization with antibodies against tumor necrosis factor (TNF-alpha) protects from the lethality of splanchnic artery occlusion shock.

Splanchnic artery occlusion shock was induced in anesthetized rats by clamping splanchnic arteries for 45 min. Survival rate, serum and macrophage tumor necrosis factor (TNF-alpha), peritoneal macrophage phagocytosis, and killing activities were evaluated. Shocked rats died within 2 hr, whilst all sham-shocked rats survived more than 6 hr. Serum and macrophage TNF-alpha was undetectable in sham-shocked rats while shocked rats exhibited increased serum (110 +/- 5 U/ml 90 min after release of occlusion) and macrophage levels (122 +/- 4.5 U/ml 90 min after release of occlusion) of TNF-alpha. Furthermore, splanchnic artery occlusion shock produced cardiovascular changes, reduced macrophage phagocytosis (23 +/- 4.6%) and killing (6 +/- 1.1%) activities, and induced a massive necrosis of the ileum. A passive immunization with a hyperimmune serum containing antibodies against murine TNF-alpha significantly protected rats from the lethal effects of splanchnic artery occlusion shock, lowered serum TNF-alpha (6 +/- 2.1 U/ml), and completely reverted the impairment in peritoneal macrophage phagocytosis (48 +/- 4.8%) and killing (13 +/- 1.5%) activities. In addition passive immunization had beneficial effects on the cardiovascular changes occurring during splanchnic artery occlusion shock and prevented necrosis of the ileum induced by this model of shock. By contrast, pretreatment with polymyxin B, an "antiendotoxin" antibiotic, did not modify the lethal effects and the TNF-alpha production induced by splanchnic artery occlusion shock. Furthermore, endotoxin was undetectable in the blood of splanchnic artery occlusion shocked rats. These findings are consistent with the involvement of TNF-alpha in splanchnic artery occlusion shock and suggest that the cytokine represents an important mediator of non-septic shock.

Animals↗

IRFI-016, a new radical scavenger, limits ischemic damage following coronary artery occlusion in rats.

The effects of IRFI-016 [2(2,3 Dihydro-5-Acetoxy 4,6,7-Trimethyl-Benzofuranyl) acetic acid] a new radical scavenger were studied following six hours of myocardial ischemia, induced by left coronary artery occlusion in male rats. The loss of myocardial Creatinine Phosphokinase activity (CPK), myocardial Myeloperoxidase Activity (MPO), ECG, survival rate, and Pressure Rate Index (PRI) were evaluated in SHAM, control (vehicle i.p. injection) and IRFI-016 (200 mg/kg i.p., 30 minutes before occlusion) treated animals. CPK was significantly reduced and MPO significantly enhanced in the ischemic areas of the hearts obtained from vehicle treated rats when compared to SHAM operated ones. Pretreatment with IRFI-016 significantly attenuated (52%) loss of CPK activity in ischemic hearts and the increase in MPO activity, but did not increase PRI, thus indicating that this substance reduces the myocardial ischemic demand for oxygen. Occlusion of the coronary artery, furthermore, was associated with an immediate rise in the ST segment of the ECG, which was significantly attenuated by IRFI-016. These findings further support the important role of free radicals in the pathogenesis of acute myocardial ischemia and suggest that IRFI-016 may be a useful agent in the treatment of myocardial occlusion injury.

Animals↗

Morphometric and neurophysiological analysis of skeletal muscle in paraplegic patients with traumatic cord lesion.

Morphometric and electrophoretic properties of soleus and medialis gastrocnemius fibres from paraplegic patients were studied 1 to 10 months following complete traumatic cord transection (spinal cord level C5-T1). In the short term of paraplegia (1-6 months) gastrocnemius medialis and soleus muscles showed predominant atrophy of IIA fibre types. In long term paraplegia (8-10 months) atrophy and reduction of type 1 fibres, with presence of high percentages of type IIB fibres, were seen in both studied muscles. The consistence in both muscles of IIB intermediate fibres in long term paraplegia, seems to indicate the initial stage of a mechanism of fibre transformation reflecting the adaptative capacity of the paretic muscle to spasticity. Electrophysiological studies of the H-reflex and the H/M ratio values reveal an increase of the H-reflex excitability in the soleus and gastrocnemius muscles during a 1 to 10 months follow-up.

Adolescent↗

[Changes in the QT interval caused by autonomic cardiovascular involvement in diabetes mellitus].

The aim of the study was to assess the role of altered autonomic regulation on changes in the QT interval. Fifty-three diabetic patients, comprising 32 men and 21 women with a mean age of 49.4 +/- 15.9 years (range 13-73 years), underwent sympathetic and parasympathetic stimulatory tests (changes in heart rate between clino- and orthostatism, lying to standing, while deep breathing, Valsalva's manoeuvre, changes of arterial pressure related to posture) to study cardiovascular reflexes. Patients who were positive for at least two of the tests were considered to be affected by autonomic neuropathy. Ten non-diabetic age-matched subjects (44.8 +/- 14.8 years) with no cardiovascular diseases were included in the study as a control group. The QTc interval was measured in basal conditions and during sympathetic and parasympathetic stimulatory tests, in clino- and orthostatism, during deep breathing and Valsalva's manoeuvre. A significantly greater QTc interval (p less than 0.05) was found in neuropathic patients compared to controls and non-neuropathic patients both in basal conditions and following stimulatory tests at the lowest heart rate (phase IV of Valsalva's manoeuvre and slow exhalation during deep breathing), while at a higher heart rate (orthostatism, L-S, deep inhalation during deep breathing, phase II of Valsalva's manoeuvre) there was no difference in QTc between controls, and neuropathic and non-neuropathic patients due to a lesser extension of the QTc in neuropathic patients. This difference appears to be the expression of autonomic dysregulation in neuropathic patients, given the lack of correlation with diabetes or duration of disease, and is only conditioned by the presence or absence of autonomopathic damage. Among other causes, the observed extension of the QT interval might therefore justify the increased frequency of sudden death in diabetic patients with cardiovascular autonomic neuropathy.

Adolescent↗

[Clinical-instrumental evaluation of the effects of quinapril treatment in mild-to-moderate hypertension].

Eleven patients with uncomplicated mild-to-moderate hypertension (diastolic pressure 95-115 mmHg) were treated for four weeks with daily single quinapril doses of 20-40 mg. Already during the second week a significant reduction in blood pressure was observed without increase of heart rate; 27.3% of patients responded to the lower dose (diastolic blood pressure [90 mmHg], and 54.6% responded to the higher dose. Drug treatment led to reduced pressure increase in response to cold stimulation without influencing the adrenergic response both in basal conditions and after cold pressor test. The drug brought about peripheral vasodilatation as shown by increased perfusion index during Doppler ultrasound examination, and improved arterial reactivity with increased perfusion index and reduced recovery time after ischemia. The reduction of angiotensin and aldosterone plasma levels during treatment was not correlated to diminished blood pressure values, indicating that the antihypertensive effect can occur via pathways different from ACE inhibition. Tolerance was excellent as shown both by clinical and laboratory evidence.

Angiotensin-Converting Enzyme Inhibitors↗

Skeletal muscle changes following myelotomy in paraplegic patients.

Pourpre's dorsal T-shaped myelotomy was performed on three paraplegic patients in which medical and electro-physiological procedures proved to be ineffective concerning muscle spasms. The myelotomy led to the elimination of spasms and of muscle hypertonicity in the lower limbs. Biopsies of the rectus femoris muscles were performed bilaterally one year before and two months following myelotomy. The first biopsy revealed fascicular atrophy, with type I fibre preferential atrophy, which is usually found in paraplegic patients. After myelotomy some histological differences were seen: reduction of type II fibre diameter and the presence of target-targetoid fibres and of atrophic dark fibres. There was a difference of fibre pattern type in hypertonic spastic muscles compared to that seen in spasm relieved by myelotomy. The morphological changes seen after myelotomy are interpreted as denervation changes because of the surgical lesion by the myelotomy on the anterior horn cells.

Adult↗

[Hypertriglyceridemia, IRI and platelet aggregation].

The Authors have studied in 13 patients with type IV hyperlipoproteinemie the behaviour of platelet aggregation and the response of IRI and blood nefa to an oral glucose load. Only two, in whom it has been possible to evidence a basal hypernefemia and a net hyperinsulinism in response to glucose oral load, showed platelet hyperaggregation to all inducers. These findings suggest that type IV hyperlipoproteinemia does not significantly influence platelet aggregation, in which IRI may have a possible role.

Adult↗

[Platelet aggregation in normal and hypertensive subjects during cold pressor test].

The Authors have studied, in 5 normal subjects and in 10 with essential arterial hypertension, the behaviour of platelet aggregation before, during and after cold pressor test. It has been possible to evidence, in hypertensive subjects, a greater responsiveness of platelets to adrenaline induced aggregation. The Authors think that such effects may be due to hyperexcitability of sympathetic nervous system, which can regulate the functional behaviour of platelets in response to cold pressor test.

Adenosine Diphosphate↗

[Calcium and endocrine pancreas secretion. I. Effects of an infusion of calcium on plasma levels of insulin and glucagon].

The authors have investigated the behaviour of IRI, IRG and blood glucose levels during a calcium infusion (15 mg/Kg body weight per 90') and during an equivalent saline infusion, in normal subjects. No evident differences were observed between the two infusions; only a slight but not significant decrease of glucagon levels appeared during calcium administration. Further experiences are clearly required, especially during alpha and beta cells stimulation, to better elucidate relationships between calcium and pancreatic endocrine secretion "in vivo".

Adult↗

[Calcium and endocrine pancreas secretion. II. Effects of an infusion of calcium on insulin and glucagon secretion induced by intravenous administration of glucose].

IRI, IRG and blood glucose levels after I.V.G.T.T. in normal subjects were not significantly modified when I.V.G.T.T. was repeated during a prolonged calcium infusion (15 mg/Kg body weight per 90'). The Authors advance the hypothesis that no closed relationships exist between serum calcium levels and insulin secretion, in these experimental conditions; with regard to glucagon secretion, further experiences are of course required namely during alpha-cell stimulation.

Adult↗

[Circadian variations in glycemia and IRI in normal subjects, young and adult diabetics and in obese subjects].

Blood sugar and IRI were followed for 24 hr in healthy patients, young and adult diabetics, and in subjects with apparently primary obesity on a standard, normal calorie diet. Morning and nocturnal insulin positivity peaks were noted in the normal subjects, though circadians variations in these parameters were mainly related to meals. This periodicity was altered in young diabetics, for whom insulin responsivity was ruled out, and in the adult diabetics, who displayed deficient insulin secretion in the morning, and delayed secretion after the afternoon meal, and in the obese subjects, the quality of whose response was close to that of the previous group. The usefulness of this type on examination in the planning of diet and drug management, quite apart from diagnosis and prognosis, is stressed.

Blood Glucose↗