[Pathology requiring admission to the neurosurgical intensive care]

A patient's admission to an ICU should benefit the patient (either short or long term). Consequently patients admitted to the ICU should be only those neurological-neurosurgical ones with one or more organ failure who need immediate or prolonged therapy with adequate monitoring and technical support not available in other wards. Normally admission depends on may other factors, the most important ones seem to be medico-legal responsibilities of the possible refusal of admission even if due to clinical reasons, organizational problems such as equipment and bed availability. There is a need for pre- and post-surgical monitoring for high risk patients. We routinely admit patients to our ICU according to the following directions: respiratory and or cardio-circulatory failure connected to the neurological pathology, impaired consciousness, neurological signs and symptoms indicating deterioration, loss of airway protective reflexes, seizured in neurological-neurosurgical patients, severe electrolyte, metabolic or nutritional disturbances which may affect the CNS; neurosurgical postoperative control, performance of complex techniques (central venous and arterial catheterization, ICP monitoring), management of multiorgan donors suitable for therapeutic transplant. The groups of pathologies observed in our ICU during 1991 where the follow-up: 442 neurological-neurosurgical patients--head trauma 141 (32%)--cerebral tumours 88 (19.9%)--vasculopathies 135 (30.6%)--others 77 (17.5%). 228 (51.5%) patients stayed for a period less than three days. According to our experience we can affirm that causes for patient's admission to neuro-ICUs are various, the legal organizational reasons have a great importance compared to the clinical ones.

Conformationally restrained analogs of sympathomimetic catecholamines. Synthesis, conformational analysis, and adrenergic activity of isochroman derivatives

In previous papers dealing with the study of the conformations and the biopharmacological activity of conformationally restrained analogs of sympathomimetic catecholamines (NE and ISO), proposals were advanced for the three-dimensional molecular models A, B, and C; these models provided information about the steric requirements for the direct activation of alpha 1, alpha 2,beta 1, and beta 2 adrenoceptors, respectively. The 1-(aminomethyl)-6,7-dihydroxyisochromans 11 and 12 and the 1-(aminomethyl)-5,6-dihydroxyisochromans 13 and 14 (1-AMDICs) are two different types of semirigid analogs of NE and ISO. The alpha 1, alpha 2, beta 1, and beta 2 adrenergic properties of the 1-AMDICs 11-14 were evaluated in vitro, both by radioligand binding assays and by functional tests on isolated preparations, and were compared with those of their parent compounds (NE and ISO). The results of a conformational study carried out by means of both 1H NMR spectrometry and theoretical calculations indicated that, in these 1-AMDICs, the presumed active groups (aryl moiety, amine nitrogen and benzylic ethereal oxygen) are in a spatial relationship corresponding to the one found for NE and ISO in their preferred conformations, which also proved to be the pharmacophoric conformation in the models A-C. By means of a comparison of the stereostructures of the 1-AMDICs 11-14 with their biopharmacological properties, it was possible to obtain a further definition of the model B with respect to the activation of the alpha 2 adrenoceptors; the superimposition of the 1-AMDICs 11 and 12 with the molecular model C made it possible to detect an area of the beta-adrenergic receptors which might hinder the fit of adrenergic drugs that are analogs of catecholamines with these receptors.

The peripheral-type benzodiazepine receptor ligands [3H]Ro 5-4864 and [3H]PK 11195 bind to the retina of rabbit, but not of turtle

The binding of [3H]flunitrazepam, [3H]Ro 5-4864, and [3H]PK 11195 to membrane preparations of the retina was studied in the turtle and rabbit. Only a single population of [3H]flunitrazepam binding sites was detected in the turtle, whereas two populations appeared to be present in the rabbit. No specific binding for [3H]Ro 5-4864 and [3H]PK 11195 could be detected in the turtle. In rabbit, both ligands bound with high affinity, revealing a significant population of binding sites (KD values of 24 +/- 2.3 and 2.2 +/- 0.8 nM, and Bmax values of 440 +/- 35 and 1,482 +/- 110 fmol/mg of protein, respectively). The binding was temperature- and protein-dependent. Displacement studies showed a similar rank order of potency of various unlabeled ligands against both [3H]Ro 5-4864 and [3H]PK 11195 (PK 11195 > Ro 5-4864 > flunitrazepam > flumazenil). These results suggest that peripheral-type benzodiazepine receptors are present in the retina of the rabbit, but not of the turtle.

Studies on specific inhibition of benzodiazepine receptor binding by some C-benzoyl-1,2,3-triazole derivatives

Certain new (1-15) or previously described (16-25) 1,2,3-triazole derivatives, characterized by a C-benzoyl substituent, were synthesized and tested for their ability to displace [3H]flunitrazepam from bovine brain membrane. Compounds 11a and 9a, bearing neutral and lipophilic substituents (phenethyl and cyclohexyl, respectively) showed the higher activity. The 5-benzoyl isomer 11b presented a lower activity, equivalent to that of the triazole acetic derivative 23, which is 4-benzyl substituted. Generally, the carboxymethyl radical in the 1-position of the triazole ring decreased the activity, probably because of intramolecular hydrogen bonding with the carbonyl function of the benzoyl substituent. The N-1 unsubstituted triazole derivatives 24 and 25 were ineffective; this result is in disagreement with our previous observations. Probably these molecules interact with the receptor site by a hydrogen bonding acceptor group and by a bulky and lipophilic portion or a hydrogen bonding donor function that is appropriately arranged.

Tricyclic heteroaromatic systems pyrazolo[1,5-a]quinoxalines: synthesis and benzodiazepine receptor activity

The synthesis and the benzodiazepine receptor activity of some pyrazolo[1,5-a]quinoxalines bearing various substituents on the tricyclic heteroaromatic system are reported. Only one of the tested compounds showed some receptor affinity.

Tricyclic heteroaromatic systems 1,2,4-triazolo[1,5-a]quinoxalines: synthesis and benzodiazepine receptor activity

The synthesis, the benzodiazepine binding activity and the "in vitro" biological effect of some 1,2,4-triazolo[1,5-a]quinoxalines, 3-aza-analogues of some previously reported pyrazolo[1,5-a]quinoxalines, are described. Molecular modelling is used to define the structural requirements of the benzodiazepine recognition site which influence the affinity and different efficacy of these rigid ligands.

Studies on annelated 1,4-benzothiazines and 1,5-benzothiazepines. VII. Synthesis and inhibition of benzodiazepine receptor binding of some 4,5-dihydro-tetrazolo[5,1-d]-1,5-benzothiazepines and 5-phenyl-s-triazolo[3,4-d]-1,5-benzothiazepines

The 4,5-dihydro-tetrazolo[5,1-d]-1,5-benzothiazepines 3a-k and the 5-phenyl-s-triazolo[3,4-d]-1,5-benzothiazepines 6a-f and 11a-c have been prepared and tested for their ability to displace [3H] flunitrazepam binding from bovine brain membranes. Some of the triazoloderivatives showed moderate binding affinity for the benzodiazepine receptor.

Reaction of 1-aminophthalazines with alpha-halocarbonyl compounds: imidazo[2,1-a]phthalazines and their benzodiazepine receptor activities

The one-pot synthesis and the benzodiazepine receptor binding activity of some imidazo[2,1-a]phthalazines bearing different substituents at position-2 and/or 3 and/or 6 is reported. The dissimilar binding results of the reported compounds are discussed in relation to the nature and/or position of the substituents on the tricyclic ring system.

3 alpha-hydroxy-5 alpha-pregnan-20-one modulation of solubilized GABA/benzodiazepine receptor complex

The allosteric modulation of the progesterone metabolite 3 alpha- hydroxy-5 alpha-pregnan-20-one (DHP) on [3H]Flunitrazepam and [35S]t-butylbicyclophosphorothionate (TBPS) binding was investigated on a soluble receptor preparation. Better results in the solubilization occurred by the use of the zwitterionic detergent CHAPS with the inclusion of the phospholipid asolectin: this treatment was found suitable to study the steroidal modulation on [3H]Flunitrazepam and [35S]TBPS binding. We found that DHP was able to enhance [3H]Flunitrazepam binding in the presence of Cl- ions, while [35S]TBPS binding was inhibited by DHP. Scatchard analysis of specific [35S]TBPS and [3H]Flunitrazepam binding yielded in a single straight line both in the controls and in the presence of the hormone; DHP increased the apparent affinity of [3H]Flunitrazepam binding without altering the apparent Bmax value. In the case of [35S]TBPS, DHP decreased the apparent Bmax value whereas the Kd value remained nearly the same.

Benzodiazepine receptor affinity and interaction of new indole derivatives

Recently, several derivatives, in which tryptamine, tyramine, and dopamine moieties are linked to the indole nucleus by an oxalyl bridge, were tested for their affinity and efficacy at the benzodiazepine receptor (BzR). To better define the structure-activity relationships (SAR) several phenylethylamine derivatives were also synthesized and tested for their affinity at the BzR. Compounds bearing a protic group on the aromatic system of the side chain show a pharmacological profile of inverse agonist, while the products lacking this group behave as partial agonist. We now report the affinity data at the BzR of new compounds in which the distance between the phenyl ring and the amide group of the side chain has been changed. The benzylamine derivatives showed a good affinity at the BzR, generally higher than that of the phenylethylamine derivatives. In this series the pharmacological profile showed to be opposite to that of the corresponding phenylethylamine derivatives, since the compounds substituted with protic groups on the phenyl ring behaved as partial agonists. Moreover, a probable interaction with the receptor site is hypothesized.

Acromegalic cardiopathy: a left ventricular scintigraphic study

In order to study "acromegalic cardiomyopathy", cardiac function was examined, using gated radionuclide ventriculography, in 18 acromegalic patients and 21 control subjects with no clinical evidence of cardiac involvement. In these acromegalic subjects, while the Ejection Fraction (EF) did not appear to be significantly different, the Peak Filling Rate (PFR) was reduced while the Time to Peak Filling Rate (TPFR) resulted significantly greater than in control subjects. These findings indicate that chronic growth hormone (GH) hypersecretion, as observed in acromegaly, deteriorate the cardiac ventricular relaxation (diastolic phase) while it has no influence on contractility (systolic phase).

Synthesis of 7-(2-dimethylaminovinyl) derivatives of pyrazolo[1,5-a] pyrimidines, as precursors of new tricyclic series. Binding studies of BDZ receptor

A series of 7-dimethylaminovinylpyrazolo[1,5-a]pyrimidines bearing an acetyl or an ethoxycarbonyl group at the 6-position turned out to be useful intermediates for the synthesis of pyrazolo[1,5-a]pyrido[3,4-e]pyrimidines and 8H-pyrazolo[5',1':2,3]pyrimido[5,4-d][1,2]diazepines. These tricyclic derivatives were studied for their affinity for the central benzodiazepine receptor, and meaningful suggestions about the structure-affinity relationship were obtained. Some of the above intermediates were also reacted with S-methylthiourea, to give a mixture of pyrazolo[5',1':1,2]pyrimido[5,6-e][1,3]diazocines and pyrazolo[1,5-a]quinazolines.

Novel adenosine receptor ligands: 1,3-disubstituted[1]benzopyrano[2,3-c]pyrazol-4-ones. Synthesis and structure-activity relationships

A series of 1,3-disubstituted[1]benzopyrano[2,3-c]pyrazol-4-ones were synthesized and tested in vitro as A1 and A2 adenosine receptor ligands. The binding results and a molecular modelling study indicated that the presence of a proton donor group in the N6-H region of adenosine and the 7-NH region of xanthine, respectively and occupancy of the A2 lipophilic area by a moiety endowed with an electrostatic effect are essential for receptor affinity and A2-selectivity.

Neuropsychological and neurophysiological assessment of the central effects of interleukin-2 administration

Neuropsychiatric disturbances may occur following interleukin-2 (IL2) administration. We studied the effects of IL2 infusion on cerebral functions in 7 patients with neuropsychological tests and event-related evoked potentials (P300). We observed a failure in the cognitive performances, an increase in latency, and a decrease in amplitude of P300. These effects followed IL2 administration and were reversible.

Tricyclic heteroaromatic systems. Synthesis and benzodiazepine binding activity of 1-substituted-3-methyl- and 3-phenylpyrazolo[4,5-c]quinolin-4-ones

The synthesis and the benzodiazepine binding activity of some 3-methyl- and 3-phenylpyrazolo[4,5-c]quinolin-4-ones bearing a heterocyclic or a substituent which is different from an aryl moiety at position-1 are reported. Molecular modelling is used to correlate the binding affinity to the chemical features and to justify the reduced receptor affinities of the reported compounds with respect to that of CGS 8216 which is taken as the lead compound.

Benzodiazepine receptor affinity and interaction of some N-(indol-3-ylglyoxylyl)amine derivatives

Several derivatives, in which tryptamine, tyramine, and dopamine moieties are linked to the indole nucleus by an oxalyl bridge, were tested for their ability to displace the specific binding of [3H]flunitrazepam from bovine brain membranes. GABA ratio and in vivo tests for the most potent compounds showed they behave as inverse agonists at the benzodiazepine receptor (BzR). To better define the structure-activity relationship (SAR) of this kind of ligand, several phenylethylamine derivatives were synthesized to evaluate their affinity to BzR. Some of these derivatives (17, 21, 24, 26, and 30) were found to exhibit high affinity (Ki = 0.51-0.085 microM) for BzR and possessed a partial agonist activity, although their chemical structure is closely related to tryptamine 2-6, tyramine 7-11, and dopamine 12-16 derivatives. A different interaction of these ligands to the receptor site is hypothesized. Moreover, all the prepared 1-methyl derivatives exhibited very low binding affinity to BzR.

Specific inhibition of binding to benzodiazepine receptors by 1,2,3-triazole derivatives

Certain 1,2,3-triazole derivatives were prepared and tested for their ability to displace [3H]diazepam that was bound to bovine brain membrane protein. All the tested compounds are essentially lacking in this ability, except for B.1, which inhibited binding of [3H]diazepam in 50% of the trials at 2.5 microM. The structure of B.1, with a 1,2,3-triazole ring with acidic properties, supports the hypothesis proposed for binding to the benzodiazepine receptor site. Comparison of B.1 with 1,2,3-triazole derivatives bearing a bicyclic substituent in position 1 of the heterocyclic ring suggests that a high steric hindrance increases the affinity of a compound for the benzodiazepine receptor.

Increased muscular phospholipase A2 activity in diabetic rats

Anomalies in prostaglandin (PG) synthesis have been suggested in both experimental and human diabetes mellitus; increased levels of plasma and tissue eicosanoids has been recently reported by several investigators. One step in prostaglandin synthesis is the enzymatic hydrolysis of membrane phospholipids by Phospholipase A2 (PLA2). Nevertheless the alternative pathway involving Phospholipase C must be considered. An evaluation of PLA2 activity is therefore a useful method for studying prostaglandin synthesis in the peripheral target tissues of insulin activity. We studied PLA2 activity in normal and diabetic rat muscle. Streptozotocin-induced diabetic rats showed significantly higher muscular PLA2 activity when compared with controls (3.04 x 10(-2) +/- 0.50 x 10(-2) versus 1.34 x 10(-2) +/- 0.35 x 10(-2) arachidonic acid pMol.mg protein-1.min-1 (p less than 0.01). This effect was not observed in diabetic animals successfully treated with insulin (1.78 x 10(-2) +/- 0.5 x 10(-2) versus 1.34 x 10(-2) +/- 0.35 x 10(-2) arachidonic acid pMol.mg protein-1.min-1), and a significant correlation was found between blood glucose and muscular PLA2 activity (r = 0.42; p less than 0.05). Our results clearly show that in streptozotocin-induced diabetic rats muscular PLA2 activity is significantly higher. The relationship between blood glucose levels and muscular PLA2 activity and the decrease of PLA2 activity after insulin treatment suggest that these changes may be related to a defect in insulin effect.

Conformational effects on the activity of drugs. 13. A revision of previously proposed models for the activation of alpha- and beta-adrenergic receptors

The alpha 1-, alpha 2-, beta 1-, and beta 2-adrenergic properties of the 2-(3,4-dihydroxyphenyl)morpholines 3 and 4 (2-DPMs), of the 3-(3,4-dihydroxyphenyl)-3-piperidinols 5 and 6 (3-DPPs), and of the trans-2-amino-5,6-dihydroxytetrahydronaphthalen-1-ols 7 and 8 and the trans-2-amino-6,7-dihydroxytetrahydronaphthalen-1-ols 9 and 10 (2-ADTNs) were evaluated in vitro both by radioligand binding assays and by functional tests on isolated preparations and compared with those of norepinephrine (NE, 1) and isoprenaline (ISO, 2). Through a comparison of the stereostructures of the compounds examined with their biopharmacological properties, it was possible to revise previously proposed molecular models for the direct activation of alpha- and beta-adrenergic receptors. The revised models (A-C) provided information about the conformational requirements of adrenergic drugs, which substantially fit in with the results of several published studies involving conformationally-restricted adrenoceptor agonists. The different position of the catecholic hydroxyl groups in model B, which refers to the alpha 2 receptors, and in model C, which refers to the beta receptors, confirms the importance of the rotameric position of the aromatic ring of catecholamines in the interaction with the alpha- and beta-adrenergic receptor.

Binding of the benzodiazepine ligand [3H]-RO 15-1788 to membrane preparations of the rabbit and turtle retina

1. We have studied the binding of [3H]-RO 15-1788 to membrane preparations of the retina of rabbit (Lepus cunicula) and turtle (Pseudemys scripta elegans). 2. In both species, [3H]-RO 15-1788 binding was maximal at 0 degrees C and decreased with increasing temperature. It was saturable, protein concentration-dependent and specific. Flunitrazepam, unlabelled RO 15-1788 and ethyl-beta-carboline were the most effective displacers, whereas RO 5,4864 was ineffective. 3. In both turtle and rabbit retina, Scatchard analysis indicated the presence of a single binding site for [3H]-RO 15-1788. The KD was 0.75 nM in both turtle and rabbit, while the Bmax were 520 and 250 fmol/mg protein in turtle and rabbit respectively. A study of the association rate of [3H]-RO 15-1788 binding revealed faster kinetics in turtle, as compared to rabbit.

Tricyclic heteroaromatic systems. Synthesis of 1,3 and 1,2 disubstituted [1]benzopyrano[4,3-b]pyrrol-4-ones and structure-activity relationships as benzodiazepine receptor ligands

The synthesis of some 1,3- and 1,2- disubstituted [1]benzopyrano-pyrrol-4-ones is reported as well as their benzodiazepine receptor affinity, as measured by the ability to displace [3H]flunitrazepam from its specific central binding. The structure-activity relationships on the whole series of disubstituted [1]benzopyrano-pyrrol-4-ones show the importance of the presence of the 1-aryl substituent and the size limitation of the 3-substituent. The size of the latter seems also to be important for the "in vitro" efficacy.

A clinical study on the use of codeine, oxycodone, dextropropoxyphene, buprenorphine, and pentazocine in cancer pain

The authors report a prospective study on 944 cancer pain patients treated with one of the following opioids: codeine, oxycodone, dextropropoxyphene, buprenorphine, and pentazocine. Level of analgesia, duration of treatment, side effects, and drop out were evaluated for each drug. Twenty-four percent of the patients still benefitted from treatment at the fourth week of study, even if high drug dosages were not used. Pentazocine did not show an evident analgesic effect during the first 2 wk of treatment. The other opioids were found to be valid therapeutic instruments for chronic cancer pain control in a limited number of patients.

On the significance of Lhermitte's sign in oncology

We present three cases of Lhermitte's sign out of twenty consecutive cases of epidural spinal cord compression due to metastatic cancer. The three patients were diagnosed with epidural thoracic compressions. The literature on Lhermitte's sign is reviewed with emphasis on the differential diagnosis of this symptom in oncological patients.

Endocrine pancreatic function in pheochromocytoma

In six patients with pheochromocytoma oral glucose tolerance test (OGTT) and arginine test were carried out. Blood insulin and glucagon response were investigated. In subjects with adrenal tumor glycemic curve pattern was typical: a rapid and exaggerated increase of glycemia followed by an abrupt drop. Absolute insulinemic response to oral glucose was normal, but inappropriate to glycemic stimulus. Arginine infusion provoked a slightly above normal increase in blood glucose and a normal increase in blood glucagon. In three of the patients studied postoperatively, reduced glycemic response to glucose was observed, whereas there were no evident variations in blood insulin and glucagon response. These data suggest that in pheochromocytoma impaired glucose tolerance is partly due to the reduced insulin response to oral glucose load.

Tricyclic heteroaromatic systems: [1]benzopyrano-pyrazol-4-ones as benzodiazepine receptor ligands

The synthesis of a series of 8-substituted 1,4-dihydro-1-aryl-3-methyl-[1]benzopyrano[3,4-d]pyrazol-4-ones (series 7) 2,4-dihydro-2-aryl-3-methyl[1]benzopyrano[4,3-c]pyrazol-4-ones (series 8) is reported. Compounds of series 7 and 8 were tested for their ability to displace [3H]flunitrazepam from bovine brain membranes and for their in vitro biological activity. The results allowed some conclusions to be drawn about the structural requirements of the benzodiazepine recognition site within this class of unusual ligands.

Renal handling of citrate in chronic renal insufficiency

Citrate is a relevant component of the inhibitory potential of the urine environment. Its excretion and renal handling have been widely studied in subjects with normal renal function, but little is known about changes induced by chronic renal insufficiency. We have investigated renal handling of citrate in 50 patients with different degrees of renal insufficiency as compared to 30 healthy subjects with normal renal function. Among patients 34 were defined as having mild renal insufficiency based on a GFR of 80 through 40 ml/min/1.73 m2 BSA, while 16 had moderate-to-severe renal failure, defined by a GFR ranging from 40 to 20 ml/min/1.73 m2 BSA. Serum citrate increased in mild renal insufficiency, while it tended to be restored to normal values at more advanced renal failure. There was a stepwise decrease in the filtered load of citrate as GFR decreased, while its renal clearance was significantly reduced only at higher degrees of renal failure. This behavior was due to an increase in the fractional excretion of citrate which was inversely related to the decrease in GFR (p = 0.015). These data suggest that serum citrate levels and excretion are governed by renal mechanisms at mild degrees of renal insufficiency; in these conditions citrate is shown to behave conformly to other poorly reabsorbable anions such as sulfate. At more advanced renal failure the ensuing metabolic acidosis plays a crucial role as a regulatory factor of both serum concentration and renal handling of citrate, by increasing cellular uptake and metabolism as well as tubular reabsorption of this anion.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet peripheral benzodiazepine receptors are decreased in Parkinson's disease

Peripheral benzodiazepine (BDZ) receptors are located in a variety of tissues, including platelets, in the nuclear and/or mitochondrial membranes. We studied the density of peripheral BDZ receptors in platelets of 10 de novo Parkinson's disease (PD) patients, 18 PD patients treated with a levodopa/carbidopa combination, and in 15 healthy subjects matched for sex and age. The binding assay was conducted using [3H]PK 11195, a specific ligand for peripheral BDZ receptors. A significant decrease in the density of [3H]PK 11195 binding sites has been observed in PD patients with respect to controls (p less than 0.01), but not between de novo and treated PD patients. No correlation has been found between the decrease in density of [3H]PK 11195 binding sites in platelets and either the duration or severity of PD. Peripheral BDZ receptors are implicated in the regulation of mitochondrial respiratory function. Thus, their decrease in PD might parallel the abnormalities in mitochondrial function recently found in this neurologic disease.

Tricyclic heteroaromatic systems. [1]benzopyranopyrrol-4-ones and [1]benzopyrano-1,2,3-triazol-4-ones as benzodiazepine receptor ligands. Synthesis and structure-activity relationships

The synthesis, ability to displace [3H]flunitrazepam binding from bovine brain membranes, and GABA ratio of some [1]benzopyranopyrroles 1a-i and [1]benzopyrano-1,2,3-triazoles 2a,b are reported. The GABA ratios of some previously synthesized pyrazoloquinolines A and [1]benzopyranopyrazoles C are also presented in order to draw some structure-activity relationships among our benzodiazepine receptor ligands. 1,3-Diarylpyrrole derivatives 1a-h show similar affinity and efficacy to that of diazepam, while the 1-aryltriazoles 2a,b have no receptor affinity. Comparison of the latter results with those on previously reported compounds suggests that there are several hydrophobic regions on the benzodiazepine recognition site whose occupation gives rise to different affinity and efficacy.

Stress-related changes of benzodiazepine binding inhibitory activity (B.B.I.A.) in humans

The presence of benzodiazepine binding inhibitory activity (B.B.I.A.) in sera from 44 psychiatric patients and from 14 healthy volunteers, prompted us to investigate whether or not this activity underwent changes in stressful situations. We measured the inhibitory units (IU) of deproteinized sera of 12 subjects, immediately before and 2 weeks after sitting for a difficult university exam. Our results showed significantly higher IU values (i.e., higher B.B.I.A. concentrations) in the samples taken just before the exam. This preliminary finding clearly suggests the involvement of B.B.I.A. in anxiety mechanisms.

[Analgesic effect of Sandostatin (SMS 201-995) in acromegaly headache]

Somatostatin analogue (Sandostatin; SMS 201-995) is utilized as a therapy in acromegaly because of its efficiency in inhibiting GH secretion; it induces some clinical improvements, such as headache remission in acromegalic patient, which seem to be unrelated to Gh normalization. We have examined 8 acromegalic patients, suffering from headache, after injection of saline solution and subsequently of SMS 201-995 (100 y), in order to study the mechanism of analgesic effect induced by Sandostatin administration. Headache, by autovaluation test, heart rate frequency, PAO, sistolic and diastolic blood velocity in medial cerebral artery, by utilizing Transcranial Doppler Sonography (SDSV), have been measured before and after saline and after SMS 201-995. GH and beta-endorphin have been also assayed in plasma samples. All patients have shown a rapid and complete improvement in headache after Sandostatin administration. At the same time we have observed an increase in SDSV and a parallel slight increase in PAO values, more evident in the diastolic phase. Plasma beta-endorphin assay has shown rather conflicting results after SMS 201-995 administration. Our results confirm an important and rapid analgesis effect of Sandostatin on acromegaly headache unrelated to GH normalization. The cerebral emodinamic changes suggest their involvement in Sandostatin induced analgesia.

Specific inhibition of benzodiazepine receptor binding by some N-(indol-3-ylglyoxylyl)amino acid derivatives: stereoselective interactions

Several optically active N-(indol-3-ylglyoxylyl)amino acid derivatives were synthesized and tested for [3H]flunitrazepam displacing activity in bovine brain membranes. IC50 values were measured and revealed that the D form of the amino acid moiety of the compounds was more potent than both the L form and racemic form, suggesting a key role of the amino acid stereochemistry on the affinity to the benzodiazepine receptors. GABA ratio and proconvulsant/convulsant data reported for the most active compounds reveal they behave as inverse agonists at the benzodiazepine receptor.

Synthesis of 1,5-diaryl-3-methyl-1H-pyrazolo[4,5-c]isoquinolines and studies of binding to specific peripheral benzodiazepine binding sites

Some 1,5-diaryl-3-methyl-1H-pyrazolo[4,5-c]isoquinolines were synthesized and tested for their ability to displace [3H]clonazepam or [3H]Ro 5-4864 from their specific binding on the central and peripheral benzodiazepine receptors. None of the tested compounds showed any activity as central binding inhibitors, while most of them were specific as peripheral binding inhibitors, although they were not very potent.

Dipyrazolo[5,4-b:3',4'-d]pyridines. Synthesis, inhibition of benzodiazepine receptor binding and structure-activity relationships

Some 2,6,8-trisubstituted dipyrazolo[5,4-b:3',4'-d]pyridin-3-ones related to the CGS series were synthesized and tested for their ability to displace [3H]flunitrazepam binding from bovine brain membranes. However the affinity for the benzodiazepine receptor of the tested compounds was lower than that of the CGS series, although it was comparable to that of chlordiazepoxide. It follows that some structure-activity relationships on the tested compounds can be drawn.

Effect of animal and vegetable protein intake on oxalate excretion in idiopathic calcium stone disease

Oxalate excretion was measured in healthy subjects and idiopathic calcium stone-formers on dietary regimens which differed in the type and amount of protein allowed; 24-h urine collections were obtained from 41 practising vegetarians and 40 normal persons on a free, mixed, "mediterranean" diet. Twenty idiopathic calcium stone-formers were also studied while on two low calcium, low oxalate diets which differed in that animal protein was high in one and restricted in the other. Vegetarians had higher urinary oxalate levels than controls and although the calcium levels were markedly lower, urinary saturation with calcium/oxalate was significantly higher. This mild hypercalciuria was interpreted as being secondary to both a higher intake and increased fractional intestinal absorption of oxalate. Changing calcium stone-formers from a high to a low animal protein intake produced a significant decrease in calcium excretion but there was no variation in urinary oxalate. As a result, the decrease in calcium oxalate saturation was only marginal and not significant. It was concluded that dietary animal protein has a minimal effect on oxalate excretion. Mild hyperoxaluria of idiopathic calcium stone disease is likely to be intestinal in origin. Calcium stone-formers should be advised to avoid an excess of animal protein but the risks of a vegetable-rich diet should also be borne in mind.

Tricyclic heteroaromatic systems: synthesis, [3H]flunitrazepam brain membrane binding inhibition, and structure-activity relationships of 2,3-dihydro-2-aryl-4-R-[1]benzopyrano[4,3-c]pyrazole-3-ones

We report the synthesis and binding activity to the central benzodiazepine receptors of some 2,3-dihydro-2-aryl-4-R-[1]benzopyrano[4,3-c]pyrazole-3-ones, which are isosteres of the CGS series. Although the compounds of the CGS series are potent ligands of the benzodiazepine receptors, none of the isosteres tested showed any significant inhibiting potency. This may be due to the change in electronic properties brought about by the replacement of the NH of the CGS series with an oxygen atom.

Further investigation on benzodiazepine binding inhibitory activity in patients with major depression or panic disorder and in healthy volunteers

Preliminary findings regarding the presence of plasmatic benzodiazepine binding inhibitory activity (BBIA) in 14 psychiatric patients prompted us to investigate it further in larger samples of psychiatric patients (n = 44) and in healthy controls (n = 14). The results have shown that BBIA is present in all the subjects included with statistically significant differences between the patients and controls. The highest concentrations were found in the patients with no difference between anxious or depressed patients, and the lowest in the healthy controls. These findings indicate that BBIA might play a role in the pathophysiology of some manifestations of anxiety.