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Biomedical subjects

G Guerrini

Publications and source records attributed to G Guerrini.

17 recordsLinked to original sources
PubMed2006

Hepatic hilum management in 250 liver-multivisceral procurements.

An accurate in vivo preparation of the hepatic hilum is a fundamental prerequisite for a successful multiorgan transplantation. Our preferred technique in this surgical setting is in vivo procurement in the heart-beating donor. This technique allows an effective exposition of the hilum structures and recognition of anatomical vascular variants, particularly those of the hepatic artery. Also, the cold ischemia time is drastically reduced, and the back-table preparation is left to a minimum. In this article we show the results of a consecutive series of 250 procurements.

Hepatectomy↗
PubMed2005

Outcome in right living related liver transplantation with branch-patch arterial reconstruction.

cRight lobe living liver transplantation is being performed worldwide with increased frequency. Difficult arterial reconstructions are often encountered because of small diameter or discrepancy between arterial stumps. The risk of arterial thrombosis is reported as high as 26%: microsurgical techniques have reduced this rate below 2%, increasing warm ischemia time. We have developed a new branch patch technique in living related liver transplantation using the donor cystic artery to create an enlarged patch anastomosis that enables increase in the vessel's diameter and therefore greater inflow to the liver. We have followed 8 patients treated with this technique. After more than 1 year (mean follow-up: 636 days) we did not observe any arterial thrombosis by Doppler ultrasound performed every 3 months. The mean resistance index was 0.68 (0.57-0.83-). Three patients died with functional graft without signs of thrombosis. We believe that the cystic artery branch patch technique is feasible in all cases. It is fast (mean time: 6.2 min), it allows a shorter warm ischemia time, and there is no increased risk of thrombosis.

Adult↗
PubMed2001

2-Arylpyrazolo[1,5-a]pyrimidin-3-yl acetamides. New potent and selective peripheral benzodiazepine receptor ligands.

A new class of N,N-diethyl-(2-arylpyrazolo[1,5-a]pyrimidin-3-yl)acetamides (3f-y), as azaisosters of Alpidem, was prepared following a novel synthetic method and their affinities for both the peripheral (PBR) and the central (CBR) benzodiazepine receptors were evaluated. Binding assays were carried out using both [3H]PK 11195 and [3H]Ro 5-4864 as radioligands for PBR, whereas [3H]Ro 15-1788 was used for CBR, in rat kidney and rat cortex, respectively. The tested compounds exhibited a broad range of binding affinities from as low as 0.76 nM to inactivity and most of them proved to be high selective ligands for PBR. The preliminary SAR studies suggested some of the structural features required for high affinity and selectivity; particularly the substituents on the pyrimidine moiety seemed to play an important role in PBR versus CBR selectivity. A subset of the highest affinity compounds was also tested for their ability to stimulate steroid biosynthesis in C6 glioma rat cells and some of these were found to increase pregnenolone formation with potency similar to Ro 5-4864 and PK 11195.

Acetamides↗
PubMed2000

Detection of haemoglobins with abnormal oxygen affinity by single blood gas analysis and 2,3-diphosphoglycerate measurement.

The aim is to determine if a single measurement of blood 2,3-diphosphoglycerate combined with gas analysis (pH, PCO2, PO2 and saturation) can identify the cause of an altered blood-oxygen affinity: the presence of an abnormal haemoglobin or a red cell disorder. The population (n=94) was divided into healthy controls (A, n=14), carriers of red cell disorders (B, n=72) and carriers of high oxygen affinity haemoglobins (C, n=8). Those variables were measured both in samples equilibrated at selected PCO2 and PO2 and in venous blood. In the univariable approach applied to equilibrated samples, we correctly identified C subjects in 93.6% or 96.8% of the cases depending on the selected variable, the standard P50 (PO2 at which 50% of haemoglobin is oxygenated) or a composite variable calculated from the above measurements. After introducing the haemoglobin concentration as a further discriminating variable, the A and B subjects were correctly identified in 91.9% or 94.2% of the cases, respectively. These figures become 93.0% or 86.1%, and 93.7% or 94.9% of the cases when using direct readings from venous blood, thereby avoiding the blood equilibration step. This test is feasible also in blood samples stored at 4 degrees C for 48 h, or at room temperature for 8 h.

2,3-Diphosphoglycerate↗
PubMed1999

Benzodiazepine receptor ligands. III. Synthesis and biological evaluation of 2- and/or 3-substituted pyrazolo[5,1-c][1,2,4]benzotriazine 5-oxides.

A new series of 2- and/or 3-substituted pyrazolo [5,1-c][benzotriazine 5-oxides and their 8-chloro derivatives were synthesized, and their benzodiazepine receptor (BZR) affinities were evaluated in vitro in comparison to lead compound 3-ethoxycarbonyl-8-chloropyrazolo[5,1-c][1,2,4]benzotriazine 5-oxide (29) [1,2]. None of the new compounds showed significant affinity for BZR. On the basis of a pharmacophore/receptor model suggested for lead compound 29, some hypotheses to explain the inactivity of new derivatives are discussed.

Animals↗
PubMed1999

Benzodiazepine receptor ligands. 4. Synthesis and pharmacological evaluation of 3-heteroaryl-8-chloropyrazolo[5,1-c][1,2,4] benzotriazine 5-oxides.

The synthesis of new 3-heteroaryl-8-chloropyrazolo[5,1-c][1,2, 4]benzotriazine 5-oxides and their binding activities at the central benzodiazepine receptor (BZR) are reported. The derivatives substituted at the 3-position with electron-rich five-membered rings, such as pyrrole 11, 2-thiophene 13c, or 3-thiophene 13d, showed good affinity values for BZR. In in vivo tests the 3-(thien-3-yl)-8-chloropyrazolo[5,1-c][1,2,4] benzotriazine 5-oxide (13d) showed selective anticonvulsant activity.

Animals↗
PubMed1997

Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones. II. Synthesis and in vitro antimicrobial evaluation.

A series of Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones (4a-p) was prepared by a simple synthetic procedure based on the reaction of hydroxylamine or methoxyamine with 2,3-substituted ethyl 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidin-6-carboxylates (3a-p). The antimicrobial activity of the obtained compounds was evaluated on a series of standard strains of Gram positive, Gram negative bacteria and fungi. None of the tested compounds showed significant activity.

Anti-Bacterial Agents↗
PubMed1996

Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones. I. Synthesis and in vitro antimicrobial evaluation.

A series of pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones (9-36) was prepared by a simple synthetic procedure based on the reaction of ethyl 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidin-6-carboxylates (1-8) and reagents (a-n) containing a primary amino group. When this set of compounds was subjected to "in vitro" antimicrobial screening, it showed no significant activity.

Anti-Bacterial Agents↗
PubMed1995

[Respiratory medicine in geriatrics. A cultural niche of relevant theoretical and practical importance].

Respiratory medicine in the elderly represents a topic of increasing interest in the developed countries, because of its peculiar clinical and therapeutical implications. In this respect, a deeper knowledge of the biology and physiology of aging lung is desirable: namely, the age-related immunological and structural changes involving the respiratory system do influence clinical presentation and response to the treatment in older people. A better understanding of the pharmacology in the elderly which is recognized to be different for several aspects from that of the general population, is mandatory in order to better approach these practical problems. This short review emphasizes the need of the "longitudinal", rather than "transversal", epidemiological surveys which are uniquely able to give useful information on the natural history, even in older populations. In addition, clinical and therapeutical peculiarities of some respiratory illnesses such as infectious lung diseases, including pulmonary tuberculosis, COLD and bronchial asthma, sleep-related respiratory disorders will be underlined. Finally, a few problems concerning the management of the geriatric subject with chronic respiratory disease will be analyzed, focusing mainly on the difficulties inherent in the inhalant therapy and functional evaluation of this kind of patients.

Aged↗
PubMed1995

New 2,3-substituted 4,7-dihydro-6-(1'H-pyrazol-3'-yl)pyrazolo[1,5-a] pyrimidin-7-ones and related compounds: synthesis and benzodiazepine receptor binding study.

The reaction between two series of 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidines 4(a-r) 7a, 7d, 7f, 7(h-j) and hydrazine in acetic acid is investigated. The structure of 4,7-dihydro-6-(1'H-pyrazol-3'-yl)pyrazolo[1,5-a]pyrimidin-7- ones 5(a-r) and 7-methyl-6-(1'H-pyrazol-3'-yl)pyrazolo[1,5-a]pyrimidines 8a, 8d, 8f, 8(h-j) are attributed to the isolated products and the pathway of this reaction is suggested. The in vitro benzodiazepine receptor (BzR) affinity of the title compounds are determined by testing their ability to displace 3H-flunitrazepam from its specific binding in bovine brain membranes. The IC50 and GABA (gamma-aminobutyric acid) ratio values give valuable indications about affinity and behavioural profile of these new BzR ligands. Included in this investigation are indicated several structure-affinity relationships of the title compounds.

Animals↗
PubMed1993

Synthesis and study of the anti-inflammatory properties of some pyrazolo[1,5-a]pyrimidine derivatives.

A series of pyrazolo[1,5-a]pyrimidin-7-ones (1c-17c) were synthesized to evaluate in vivo and in vitro effects induced by structural modifications at the 2 position of 4,7-dihydro-4-ethyl-2-phenylpyrazolo[1,5-a]pyrimidin-7-one (FPP028). This substance, which has been previously studied, is a weak inhibitor of prostaglandin biosynthesis and a nonacid analgesic and anti-inflammatory agent devoid of ulcerogenic properties. To gain more insight into the mechanism of action of this class of compounds, several in vivo tests were carried out, such as carrageenan-induced rat paw edema and pleurisy. In vitro tests include some studies of leukocyte functions, such as superoxide production and myeloperoxidase release. In vitro effects on arachidonic acid-, adenosine 5'-diphosphate-, and platelet-activating factor-induced platelet aggregation were also studied. Different anti-inflammatory activities were observed, depending on the nature of substituents at the 2 position; these differences are probably linked to the capacity of these compounds to inhibit leukotrienes and/or prostaglandin biosynthesis with different selectivity. 4,7-Dihydro-4-ethyl-2(2-thienyl)pyrazolo[1,5-a]pyrimidin-7-one (7c) proved to be the most interesting compound of the novel synthesized series, showing powerful pharmacological activity in vivo as well as in vitro, together with very weak acute toxicity.

Animals↗
PubMed1993

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.

Binding, Competitive↗
PubMedDate not supplied

Energetics of kayaking at submaximal and maximal speeds.

The energy cost of kayaking per unit distance (C(k), kJ x m(-1)) was assessed in eight middle- to high-class athletes (three males and five females; 45-76 kg body mass; 1.50-1.88 m height; 15-32 years of age) at submaximal and maximal speeds. At submaximal speeds, C(k) was measured by dividing the steady-state oxygen consumption (VO(2), l x s(-1)) by the speed (v, m x s(-1)), assuming an energy equivalent of 20.9 kJ x l O(-1)(2). At maximal speeds, C(k) was calculated from the ratio of the total metabolic energy expenditure (E, kJ) to the distance (d, m). E was assumed to be the sum of three terms, as originally proposed by Wilkie (1980): E = AnS + alphaVO(2max) x t-alphaVO(2max) x tau(1-e(-t x tau(-1))), were alpha is the energy equivalent of O(2) (20.9 kJ x l O(2)(-1)), tau is the time constant with which VO(2max) is attained at the onset of exercise at the muscular level, AnS is the amount of energy derived from anaerobic energy utilization, t is the performance time, and VO(2max) is the net maximal VO(2). Individual VO(2max) was obtained from the VO(2) measured during the last minute of the 1000-m or 2000-m maximal run. The average metabolic power output (E, kW) amounted to 141% and 102% of the individual maximal aerobic power (VO(2max)) from the shortest (250 m) to the longest (2000 m) distance, respectively. The average (SD) power provided by oxidative processes increased with the distance covered [from 0.64 (0.14) kW at 250 m to 1.02 (0.31) kW at 2000 m], whereas that provided by anaerobic sources showed the opposite trend. The net C(k) was a continuous power function of the speed over the entire range of velocities from 2.88 to 4.45 m x s(-1): C(k) = 0.02 x v(2.26) (r = 0.937, n = 32).

Adolescent↗