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Biomedical subjects

A Galli

Publications and source records attributed to A Galli.

At least 145 records · Page 8Linked to original sources

Thermal induction and temperature control in the hyperthermic antiblastic regional perfusion with extra corporeal circulation.

An optimal treatment temperature choice is based on a compromise between the higher values desirable for best synergic effects between heat and drugs and the lower values required to avoid drug inactivation and tissue damage. Temperature uniformity throughout the limb under treatment favors approaching the highest temperature compatible with the above compromise. Several modifications have been introduced in the methodology during our experience consisting of more than 100 perfusions. The induction of true hyperthermic temperatures (41.5-41.8 degrees C) is achieved both heating the perfusate and directly heating the limb by means of a warm-water circulation blanket, thus insuring an optimal thermal flow to the superficial tissues. Devices in the extra-corporeal circuit have also been adopted to obtain a fast and accurate perfusate temperature control. The following results can be obtained: (a) a short delay time is required to reach the therapeutic temperature range; (b) the perfusate temperature is maintained at a value close to 40 +/- 0.5 degrees C during the whole hyperthermic phase of the treatment; (c) the various districts of the limb are maintained at substantially homogeneous hyperthermic temperature.

Antineoplastic Agents↗

Glycine-related amino acids stereoselectively affect N-methyl-D-aspartate receptor-mediated contractions of guinea pig ileum: comparison with the inhibition of strychnine-insensitive [3H]glycine binding to rat cortical membranes.

Ten microM glycine, D-serine and D-alanine potentiated L-glutamate (30 microM)-induced contractions of the guinea pig ileum by an average of 35, 53 and 24%, respectively. On the contrary, D-cysteine, at the same concentration, caused a 21% inhibition of the contractile response to L-glutamate. This inhibitory effect of D-cysteine was abolished by 10 microM glycine. The corresponding L-isomers of these amino acids, namely L-serine, L-alanine and L-cysteine and the other amino acids tested, possessed negligible activity or were inactive in this test. The IC50 values of the same compounds for strychnine-insensitive binding of [3H]glycine (20 nM) to cortical membranes from the brain of the rat were: 0.26 microM, glycine; 1.2 microM, D-serine; 2.1 microM, D-alanine; 8.6 microM, D-cysteine; 51 microM, L-serine; 90 microM, L-alanine; greater than 1000 microM, L-cysteine. On the whole, these results point out a strict requirement for stereoselectivity for both of the effects examined. In addition, the results obtained in the ileum preparation suggest that D-cysteine may act as an antagonist, rather than as an agonist at the glycine site which regulates the responses of N-methyl-D-aspartate receptors.

Amino Acids↗

Vanadium: genetical and biochemical investigations.

Ammonium metavanadate was studied for its ability to induce mitotic gene conversion and reverse point mutation in the D7 strain of Saccharomyces cerevisiae. Metavanadate increased the convertant and revertant frequencies; the highest activity was observed without metabolic activation. This indicated that the S9 hepatic fraction and yeast cells in logarithmic phase (and containing a high level of cytochrome P450) biotransform vanadate, probably reducing it to vanadyl. In addition, the effect of ammonium metavanadate on the hepatic monooxygenase system was studied in mice by measuring the level of cytochrome P450 and determining the activities of aminopyrine N-demethylase, p-nitroanisole O-demethylase and 7-ethoxycoumarin O-deethylase in mouse liver microsomal fraction. The results indicated that this compound reduced mono-oxygenase activity and also the level of cytochrome P450.

7-Alkoxycoumarin O-Dealkylase↗

Finding of a bull with Y;17 translocation.

A bull with a Y;17 translocation was found. This finding was examined by G banding, C banding, and studying the cytodensitometric profiles of G banding. The subject appeared phenotypically normal, with normal reproductive organs and testicular function (GnRH Test). There was a slight pathospermia (oligozoospermia and asthenozoospermia), therefore the portions of Y chromosome with TDF and AZF were not lost.

Animals↗

[Anatomo-functional consequences of the radical surgery of the cervico-cephalic region in oncologic patients].

The role of surgery in head and neck cancer treatment is now well established, as it appears the most effective approach to such patients, while other therapies (i.e. chemotherapy, radiotherapy) can be of some help as second choice procedures. Surgery demonstrates however its own pitfalls, as it can often cause secondary anatomo-functional defects. The main problems appear to be related to the impossibility of physiological feeding following composite resection for oral cancer. An immediate reconstruction by transposition of myocutaneous flaps is of the utmost importance, as it reestablishes the preoperative condition lessening hospitalization time and postoperative disabilities. Neurological lesions, an unfrequent major complication of cervical lymphadenectomy, can cover a wide range of seriousness, from hardly detectable sensorial deficits to the impossibility of spontaneous ventilation. In this paper the Authors, on the basis of their experience, describe the measures to be taken in order to avoid secondary lesions (or to minimize their effects) in head and neck cancer surgery.

Humans↗

[Value of plasma fructosamine in non-diabetic and diabetic chronic renal failure].

Plasma fructosamine concentrations were measured in non-diabetic and diabetic patients with chronic renal failure divided into two three groups: patients without dialysis, under haemodialysis and under continuous ambulatory peritoneal dialysis. In non-diabetic patients plasma fructosamine values were consistently higher than in a control population (2.26 +/- 0.26 mmol/l), being 2.38 +/- 0.35 mmol/l in patients without dialysis, 2.57 +/- 0.33 mmol/l in patients under peritoneal dialysis and 2.67 +/- 0.31 mmol/l in patients under haemodialysis. In diabetic patients, plasma fructosamine values were increased, being equal to, or higher than 3 mmol/l; these values were almost identical with those obtained in populations of diabetics without renal pathology. Considering that Hb Alc values are difficult to interpret in chronic renal failure owing to anaemia and to the analytical problems raised by haemoglobin carbamylation, the fructosamine test may well be a reliable marker for the monitoring of diabetes in patients with chronically impaired renal function.

Diabetes Mellitus, Type 1↗

[Role of lipid peroxidation in the formation of atheroma].

The demonstration that lipid peroxidation (enzymatic or non enzymatic oxidation of polyunsaturated fatty acids) is involved and plays a pathophysiological role (in relation to the metabolic pathways of prostaglandins, leukotrienes and to others inflammation-related events) in the initiation of arteriosclerotic plaques is a breakthrough in the pathogenesis of atheroma. Macrophages play a central role in this mechanism. Indeed foam cells are macrophages loaded with oxidized low density lipoproteins (LDL). These oxidized LDL are preferentially recognized by macrophages thanks to their scavenger receptor. The role of such foam cells in the initiation and development of atheroma is well known. The formation of arteriosclerotic plaques results in important endothelial alterations, and endothelial cells lose their protective ability to prevent platelet aggregation and related thrombotic events. Inflammation and thrombosis are overlapping phenomena which are mediated by common cells (platelets, polymorphonuclear leucocytes, monocytes, macrophages, endothelial cells). During the activation of such inflammatory cells a number of eicosanoids are produced, and the profile of such metabolites is largely controlled by cellular interactions. In addition these inflammatory cells have the ability to produce oxygen free radicals, and initiate non enzymatic lipid peroxidation.

Arteriosclerosis↗

Glycine and kynurenate modulate the glutamate receptors in the myenteric plexus and in cortical membranes.

The responses evoked by stimulation of the N-methyl-D-aspartate receptors in the guinea-pig myenteric plexus were potentiated by micromolar concentrations of glycine and were non-competitively antagonized by kynurenate (IC50: 60 microM). The effects of kynurenate were competitively prevented by glycine. Furthermore, kynurenate displaced [3H]glycine from its binding sites on rat cortical membranes (IC50: 20 microM). Kynurenate and glycine, therefore, probably act at the same site, evoking opposite effects on the function of the ion channel complex of the N-methyl-D-aspartate receptor.

2-Amino-5-phosphonovalerate↗

Galactosylceramide: a reliable serum index of demyelination in multiple sclerosis.

Eight patients with multiple sclerosis were followed for several months to determine if serum levels of galactosylceramide, a major lipid component of myelin, correlate with the clinical evolution of the disease. In the patients with the chronic progressive form of multiple sclerosis, galactosylceramide remained undetectable. In the patients with relapsing-remitting multiple sclerosis, there was a good correlation between the elevation of serum galactosylceramide levels and clinical relapses. This serum assay should prove of value in the follow-up of patients with multiple sclerosis.

Adult↗

Quinoxalines interact with the glycine recognition site of NMDA receptors: studies in guinea-pig myenteric plexus and in rat cortical membranes.

1. The effects of several quinoxalines, including 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 6,7,dinitroquinoxaline-2,3-dione (DNQX), and of two kynurenates, kynurenate (KYNA) and 7-Clkynurenate (7-Cl-KYNA), have been evaluated on the N-methyl-D-aspartate (NMDA) receptors present in the guinea-pig ileum myenteric plexus preparation and on the strychnine-insensitive [3H]-glycine binding sites of cortical membranes. 2. Quinoxalines and kynurenates antagonized in a non-competitive manner L-glutamate-induced contraction. Their IC50s were (in microM): 5 for 7-Cl-KYNA, 7.5 for 6,7-Cl-3-hydroxy-2-quinoxaline carboxylate (6,7-Cl-HQCA), 20 for DNQX, 50 for CNQX, 76 for KYNA and 125 for 3-hydroxy-2-quinoxaline carboxylate (HQCA). 3. Glycine (5-50 microM) completely reversed the antagonism displayed by both quinoxalines and kynurenates. The interaction between glycine and the tested compounds appeared to be competitive in nature. 4. Quinoxalines and kynurenates displaced, in a concentration-dependent manner, [3H]-glycine from its strychnine-insensitive binding sites present in rat cortical membranes. Their IC50s for this action were (in microM): 0.45 for 7-Cl-KYNA, 0.6 for 6,7-Cl-HQCA, 2.4 for DNQX, 3.5 for CNQX, 20 for KYNA and 40 for HQCA. 5. When the IC50s for the displacement effect of [3H]-glycine binding were plotted against the IC50s obtained in the myenteric plexus, a significant correlation was found. 6. These data show that quinoxalines and kynurenates may antagonize the responses to L-glutamate by interacting with the glycine recognition sites of the NMDA receptor ion channel complex.

Animals↗

[Serum and lacrimal proteins in acquired immunodeficiency syndrome].

The concentrations of seven proteins [albumin (Alb), immunoglobulins (IgG, A, M), lactoferrin (Lf), lysozyme (Lzm) and beta 2-microglobulin (beta 2 m)] were measured in the tears and serum of 10 patients with acquired immune deficiency syndrome (AIDS) and in 13 normal subjects. In the AIDS group, alteration of the blood-lacrimal barrier was revealed by the high Alb clearance. In this group also, the significantly high IgG, IgA, IgM and beta 2 m concentrations indicated a systemic and local immune response, with passive transfer of these proteins from serum to tears. However, Lf and Lzm concentrations were normal, showing that the secretory activity of the lacrimal gland remained unchanged.

Acquired Immunodeficiency Syndrome↗

Distribution of thiobarbituric acid-reactive substances in lipoproteins and proteins in serum.

We assessed the distribution of malondialdehyde (MDA) in lipoproteins and proteins in serum after using two procedures to separate the lipoproteins: sequential ultracentrifugation or selective precipitation with a sodium phosphotungstate and magnesium chloride reagent followed by ultracentrifugation of the supernate. MDA concentrations were determined by the thiobarbituric acid reaction and quantified by fluorometry. We found that 43% of the thiobarbituric acid-reactive substances (TBARS) was bound to the lipoproteins--27% to very-low- and low-density lipoproteins (VLDL-LDL) and 16% to high-density lipoproteins (HDL)--and from 11.5% to 15.8% to proteins, depending on the separation procedure. Residual unbound TBARS were located in the ultracentrifugation layers that contained no lipoproteins or proteins. The TBARS concentration in serum lipoproteins containing apolipoprotein B (i.e., VLDL-LDL) was the same after ultracentrifugation or selective precipitation. We therefore consider the precipitation method more suitable for routine TBARS determination in these lipoproteins, because it is easier to handle and faster. However, for determination of TBARS in HDL, selective precipitation requires subsequent ultracentrifugation at a density of 1.21 kg/L.

Adult↗

Protection against diisopropylfluorophosphate intoxication by meptazinol.

The protective action of meptazinol against diisopropylfluorophosphate (DFP) was evaluated in mice which were not receiving any other therapy and in preparations of electric eel AChE and horse serum BuChE. Meptazinol injected subcutaneously in mice produced a dose-dependent reduction in the mortality resulting from a LD99.1 (8 mg/kg sc) of DFP administered later. The effectiveness of protection was inversely correlated to the time between meptazinol and DFP administrations. Under these conditions, the ED50s (95% confidence limits) of meptazinol given 15, 30, and 60 min before poisoning were 7.2 (6.4-8.1), 15.8 (13.7-18.2), and 28 (23.5-33.3) mg/kg, respectively, while full protection (100% of survivors) was obtained with 15, 30, and 60 mg/kg drug doses, respectively. Meptazinol was completely ineffective against DFP-induced lethality when administered 3 min after the poison. The protective ratio of 30 mg/kg meptazinol injected 15 min before DFP was 5.0. Pretreatment of mice with 15, 30, and 60 mg/kg meptazinol 15 min before DFP (8 mg/kg) increased brain AChE activity in DFP-treated mice from 5 +/- 0.5% to 16.2 +/- 2.5%, 42.5 +/- 4%, and 81.2 +/- 4% of control values, respectively, while it failed to increase plasma BuChE activity. Finally, concentrations of meptazinol ranging between 0.1 and 10 microM were found to afford complete protection of eel AChE against irreversible inhibition by 40 microM DFP. By contrast, horse serum BuChE was not protected against the same inhibitor by concentrations of meptazinol up to 1 mM. It is concluded that protection against DFP intoxication by meptazinol is most probably due to its protective action toward AChE.

Acetylcholinesterase↗

Transposition of myocutaneous flaps in breast reconstruction following radical mastectomy: latissimus dorsi vs. rectus abdominis flap.

We evaluated two homogeneous groups of patients (20 each) who had undergone radical mastectomy and who underwent breast reconstruction in our department by transposition of a latissimus dorsi or of a rectus abdominis myocutaneous flap. The results achieved were very similar (in terms of postoperative hospitalization, complication rate, thoracic symmetry). We therefore believe that both these techniques should be considered as first choice in breast reconstruction following radical mastectomy. However, from the aesthetic viewpoint, the use of the latissimus dorsi is best suited to tall, slim patients, whereas the rectus abdominis allows us to obtain better results in patients of sturdy build, with a voluminous residual breast.

Adult↗

Metastatic spread of floor of the mouth squamous cell carcinoma via pectoralis major myocutaneous flap.

In a patient with recurrent head and neck squamous cell carcinoma, reconstruction of the floor of the mouth was carried out by transposition of a pectoralis major myocutaneous flap after composite resection. Twelve months after surgery, a chest wall metastasis corresponding to the site of the vascular pedicle was observed. It appears that the lymphatic and hematogenous tumor spread can occur along the vascular pathways of a transposed myocutaneous flap.

Adult↗