Family Pediatrician and Public Health collaboration, an alliance to increase vaccination coverage: an experience with MenB vaccination in Italy

BACKGROUND

Invasive Meningococcal Disease is a severe disease mainly affecting infants and young children. Most infections are caused by serogroups A, B, C, W, X, and Y. In the last 10 years, serogroup B has been the main cause of Invasive Meningococcal Disease in Europe. Recent data resulting from an observational study conducted in Italy show a significant reduction in the number of Invasive Meningococcal Disease cases due to Neisseria meningitidis B after the introduction of vaccine 4CMenB. Thus, the Naples Team of Federation of Italian Primary Care Pediatricians and the Public Health Department started an active collaboration focused on vaccination process management (named "Progetto Via") with the aim of increasing Meningococcal B vaccination coverage.

STUDY DESIGN

Source of data is the regional platform "GE.VA.". Every Primary care Pediatrician uses daily to record vaccination activity. This platform is integrated with data entered by operators of the District/Vaccination Center.

METHODS

Time: January 2019 - December 2019. The Federation of Italian Primary Care Pediatricians/Naples organized a meeting to identify six coordinators. The pediatricians could choose to counsel in their own offices and send children to the vaccination center or to counsel and vaccinate directly in their own clinics.

RESULTS

A total of 78 pediatricians took part in the project: 46 did only counseling and 32 did both counseling and vaccination in their medical clinic. Data obtained show an overall average vaccination coverage growth of about 13% in the first 4 months of the survey, and a further growth of about 11% in the following seven months, with a total growth in the entire period of 24%. The pediatricians' counseling is essential to recover non-compliant subjects, considering both the relationship of trust with the families and the visits already scheduled as an ideal moment for vaccinations' status check.

CONCLUSIONS

The project highlights how an effective collaboration between family pediatricians and the Local Health Authority becomes valuable in getting closer to reach the Ministerial goal of 95%. Vaccination coverage increased significantly when family pediatricians supported the activity of vaccine centers in distress in many regional situations. The trust relationship, the hourly availability and the capillary network of family pediatricians' clinics were key elements for the success of this project and were also recognized by parents.

The Effect of Weaning with Adult Food Typical of the Mediterranean Diet on Taste Development and Eating Habits of Children: A Randomized Trial

Mediterranean Diet (Med Diet) is one of the healthiest dietary patterns. We aimed to verify the effects of weaning (i.e., the introduction of solid foods in infants previously fed only with milk) using adult foods typical of Med Diet on children eating habits, and on the microbiota composition. A randomized controlled clinical trial on 394 healthy infants randomized in a 1:1 ratio in a Med Diet group weaned with fresh; seasonal and tasty foods of Med Diet and control group predominantly weaned with industrial baby foods. The primary end point was the percentage of children showing a good adherence to Med Diet at 36 months. Secondary end points were mother’s changes in adherence to Med Diet and differences in children gut microbiota. At 36 months, children showing a good adherence to Med Diet were 59.3% in the Med Diet group and 34.3% in the control group (p < 0.001). An increase in adherence to the Med Diet was observed in the mothers of the Med Diet group children (p < 0.001). At 4 years of age children in the Med Diet group had a higher gut microbial diversity and a higher abundance of beneficial taxa. A Mediterranean weaning with adult food may become a strategy for early nutritional education, to develop a healthy microbiota, to prevent inflammatory chronic diseases and to ameliorate eating habits in children and their families.

Leukocyte integrin very late antigen-4/vascular cell adhesion molecule-1 adhesion pathway in splanchnic artery occlusion shock

We investigated the role played by the very late antigen-4 (VLA-4)/ vascular cell adhesion molecule-1 (VCAM-1) interaction in the pathogenesis of splanchnic artery occlusion shock. Splanchnic artery occlusion shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min. Sham operated animals were used as controls. Survival time, serum tumour necrosis factor (TNF-alpha), monocyte and lymphocyte cell count and the responsiveness to acetylcholine of aortic rings were studied. Furthermore we investigated the VCAM-1 expression on vessel endothelium and the percentage of VLA-4 positive leukocytes. Splanchnic artery occlusion shocked rats had a decreased survival time (76 +/- 10 min, while sham shocked rats survived more than 4 h), increased serum levels of TNF-alpha (328 +/- 11 U/ml), a decreased number of both monocytes and lymphocytes and reduced responsiveness to acetylcholine (10 nM-10 microM) of aortic rings. In addition we found an increased expression of endothelial VCAM-1 on aortic rings and a reduced percentage of VLA-4 positive lymphocytes and monocytes. Passive immunization with specific antibodies raised against either VCAM-1 or VLA-4 (2 mg/kg, i.v., 3 h before splanchnic artery occlusion shock) increased survival, improved monocyte and lymphocyte count and restored the responsiveness of aortic rings to acetylcholine (P < 0.01). Finally, inhibition of TNF-alpha biosynthesis reversed the increased endothelial expression of VCAM-1 and the reduced percentage of integrin VLA-4 positive leukocytes. Our findings suggest that (i) VLA-4/VCAM-1 interaction has a role in the pathogenesis of circulatory shock; (ii) this interaction might be a target for new therapeutic approaches to the therapy of low-flow states.

Effects of S-ethylisothiourea, a potent inhibitor of nitric oxide synthase, alone or in combination with a nitric oxide donor in splanchnic artery occlusion shock

1. The aim of this study was to compare the effects of an intravenous infusion of a potent and non selective nitric oxide synthase inhibitor S-ethylisothiourea (Ethyl-TU) with that of a nitric oxide (NO) donor on the pathological sequelae associated with splanchnic artery occlusion (SAO) shock. In addition the effects of the combination of these two treatments were also investigated. 2. SAO shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min. Sham operated animals were used as controls. Survival time, white blood cell (WBC) count, mean arterial blood pressure, myeloperoxidase activity (MPO; studied as a quantitative means to evaluate neutrophil accumulation) and the responsiveness of aortic rings to acetylcholine (ACh, 10 nM-10 microM) and to phenylephrine (PE, 1 nM-10 microM) were studied. 3. SAO shocked rats had a decreased survival rate (0% survival 2 h after the release of occlusion) and survival time (76 +/- 10 min), increased MPO activity in the ileum (3.39 +/- 0.8 u x 10(-3) g-1 tissue), a marked leukopenia and a profound hypotension. In addition aortic rings from shocked rats showed a marked hyporeactivity to PE and reduced responsiveness to ACh. Endothelium denuded aortic rings had also a marked hyporeactivity to PE. 4. In vivo administration of Ethyl-TU (0.1 mg kg-1 h-1, beginning 1 min after the onset of reperfusion) significantly increased survival time and rate, improved mean arterial blood pressure, restored the responsiveness to PE, but did not change MPO activity, leukopenia or the impairment in the responsiveness of aortic rings to ACh. Addition of Ethyl-TU (2 microM) to endothelium denuded aortic rings in vitro, restored the marked hyporeactivity to PE. Administration of the NO donor C87-3754 (0.75 mg kg-1 h-1, beginning 1 min after the onset of reperfusion) slightly increased survival time and reduced MPO activity and leukopenia, but did not change survival rate and mean arterial blood pressure. In addition C87-3754 restored the responsiveness of aortic rings to ACh to control values, but did not modify the hyporeactivity to PE. The combination of these two interventions produced a higher degree of protection than either Ethyl-TU or C87-3754 alone. In fact, co-administration of Ethyl-TU plus C87-3754 completely prevented mortality, reduced MPO activity, attenuated leukopenia and the profound hypotension and restored the impaired responsiveness of aortic rings to PE and ACh. 5. Our study suggests that treatment with a nitric oxide synthase inhibitor combined with an NO donor may be a new therapeutic approach to the treatment of splanchnic artery occlusion shock.

Monocytes and lymphocytes as active participants in the pathogenesis of experimental shock

We investigated the role played by monocytes and lymphocytes in the pathogenesis of experimental shock. Splanchnic artery occlusion (SAO) shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min followed by reperfusion. Sham operated animals were used as controls. SAO shocked rats had a decreased survival time (80 +/- 11 min, while sham shocked rats survived more than 4 h), increased serum (248 +/- 21 U/ml) and macrophage (145 +/- 15 U/ml) levels of TNF-alpha, enhanced myeloperoxidase (MPO) activity in the ileum (3.38 +/- 0.2 U x 10(-3)/g tissue), decreased number of monocytes, lymphocytes and neutrophils and a profound hypotension. In addition we found an increased expression of vascular cell adhesion molecule-1 (VCAM-1) on aortic endothelium and a reduced percentage of VLA-4 positive monocytes and lymphocytes. Inhibition of TNF-alpha synthesis, reversed the increased endothelial expression of VCAM-1, increased the percentage of integrin VLA-4 positive leukocytes and improved monocyte, lymphocyte and neutrophil count. Furthermore a passive immunization with specific antibodies raised against VCAM-1 (2 mg/kg, i.v. 3 h before SAO) increased survival, reduced MPO activity in the ileum (0.034 +/- 0.04 U x 10(-3)/g tissue) and improved mean arterial blood pressure. Our data suggest that monocytes and lymphocytes participate in the pathogenesis of splanchnic ischaemia-reperfusion injury and may amplify the adhesion of neutrophils to peripheral tissues.

Protection of ischemic and reperfused rat myocardium by the nonglucocorticoid 21-aminosteroid U-74389G, a new inhibitor of lipid peroxidation

We studied the effects of the aminosteroid U-74389G (21-[4-(2, 6-di-1-pyrrolidinyl-4-pyrimidinyl)-1-piperazinyl]-pregna-1,4,9(11)- triene-3,20-dione(2)-2-butenenedionate), a putative inhibitor of lipid peroxidation, which protects the rat myocardium after ischemia and reperfusion. Pentobarbital-anesthetized (50 mg/kg) rats were subjected to 60 min of occlusion of the left main coronary artery followed by 60 min of reperfusion. Myocardial ischemia/reperfusion produced a large cardiac necrosis (81 +/- 8.6% of the area at risk and 65 +/- 14.8% of the total left ventricle), polymorphonuclear infiltration in the jeopardized tissue (myeloperoxidase activity = 4.2 +/- 2.1 U X 10(-3)/g tissue in the area at risk and 7.0 +/- 3.6 U X 10(-3)/g tissue in the necrotic area), hydroxyl radical (OH.) formation (0.55 +/- 0.16 nmol/ml), increased plasma malonylaldehyde (40.2 +/- 3.9 nmol/ml) and lactate dehydrogenase (431 +/- 30 mIU/ml) and caused a decrease in the survival rate. Treatment with U-74389G (15 and 30 mg/kg i.v.) at the onset of reperfusion caused a reduction of necrotic area expressed as a percentage of either the area at risk (76 +/-7.4% with 15 mg/kg and 69 +/- 13.5% with 30 mg/kg; P < .05) or the total left ventricle (53 +/- 13.6% with 15 mg/kg and 46 +/- 16.8% with 30 mg/kg; P < .05). Treatment U-74389G reduced the myeloperoxidase activity, evaluated as an index of neutrophil infiltration, both in the area at risk (2.7 +/- 1.1 and 2.2 +/- 1.7 U X 10(-3)/g tissue with the doses of 15 and 30 mg/kg, respectively; P < .05) and in the necrotic area (4.3 +/- 2.4 and 3.8 +/- 2.9 U X 10(-3)/g tissue with 15 and 30 mg/kg, respectively; P < .05); decreased OH. formation (measured indirectly by the administration of the trapping agent salicylic acid); and analyzing the hydroxylation product 2,5-dihydroxybenzoic acid during reperfusion (0.35 +/- 0.12 and 0.32 +/- 0.15 nmol/ml with the doses of 15 and 30 mg/kg, respectively; P < .005). Treatment inhibited lipid peroxidation by blunting plasma malonylaldehyde (26.7 +/- 3.1 and 20.8 +/- 3.3 with the doses of 15 and 30 mg/kg, respectively; P < .001), prevented cellular disruption by reducing the increase of plasma lactate dehydrogenase (288.6 +/- 28 and 201.3 +/- 16 mIU/ml with the doses of 15 and 30 mg/kg, respectively; P < .001). Finally, U-74389G enhanced the survival rate evaluated at the end of the experiment (from 40 to 87%). These outcomes suggest that the drug may have potential for cardioprotective use in acute myocardial infarction.

Endotoxin tolerance impairs a pertussis-toxin-sensitive G-protein regulating tumour necrosis factor release by macrophages from tumour-bearing rats

The aim of this work was to study whether a G-protein regulates lipopolysaccharide (LPS) induced TNF-alpha production in tumour-bearing rat peritoneal macrophages differently to in normal rats. We also investigated whether a state of 'early endotoxin tolerance' affects LPS induced TNF-alpha release via a G-protein-mediated phenomenon. LPS-stimulated (50 micrograms ml-1 of Salmonella enteritidis LPS) TNF-alpha release was investigated in peritoneal macrophages harvested from both normal rats and tumour-bearing rats. Cholera toxin (10, 100 and 1000 ng ml-1) did not significantly modify LPS-induced TNF-alpha release. In contrast pertussis toxin (0.1, 1.0 and 10 ng ml-1) significantly increased LPS-induced TNF-alpha release and inhibited LPS-stimulated prostaglandin E2 (PGE2) production in both normal rat macrophages and tumour-bearing rat macrophages. Pertussis toxin effects on these LPS responses were correlated with a pertussis-toxin-mediated ADP-ribosylation of a 41 kDa protein(s). The LPS-mediated responses were significantly greater in macrophages from tumour-bearing rats than in macrophages from normal rats. PGE2 (10(-9), 10(-8) and 10(-7) M) suppressed LPS-induced TNF-alpha production in a dose-dependent fashion. A state of 'early endotoxin tolerance' was then induced in tumour-bearing rats by a single intravenous injection of 125 micrograms rat-1 of LPS, and experiments were performed on peritoneal macrophages harvested 24 h after LPS injection. In tolerant macrophages pertussis toxin induced an increase in LPS-stimulated TNF-alpha release and an inhibition in LPS-stimulated PGE2 release significantly lower than in macrophages harvested from non-tolerant tumour bearing rats. Our results suggest that a pertussis-toxin-sensitive G-protein may serve to regulate the synthesis of TNF-alpha in rat peritoneal macrophages and that the activity of this pertussis-sensitive G-protein is increased in macrophages from tumour-bearing rats. Furthermore, our experiments would indicate that a 'state of endotoxin tolerance', caused by altering the function of presumably a Gi-protein, may exert beneficial effects on the functions of macrophages in tumour-bearing rats.

Effects of cloricromene on the levels of endothelin and on the microcirculatory function in peripheral atherosclerotic arteriopathies

The effects of cloricromene on plasma endothelin-1 (ET-1) levels and on microcirculatory function in 9 patients with peripheral atherosclerotic arteriopathy (PAA) and in healthy control subjects were studied. ET-1 levels and microcirculatory function were evaluated both under basal conditions and 30, 60, and 90 min after acute administration of cloricromene (30 mg i.v.). PAA patients had significantly increased levels of ET-1 and impaired vascular parameters (studied by means of Winsor's Index, Gosling's Index, postischemic perfusion index and recovery time) when compared to control subjects. The acute administration of cloricromene (30 mg i.v.) did not change plasma ET-1 both in control subjects and in patients with PAA. In contrast, cloricromene produced a significant improvement in the postischemic perfusion index and in recovery time in arteriopathic patients. Control subjects and patients with PAA also underwent a cold pressor test (CPT) under basal conditions and (72 h later) 30 min after an acute intravenous administration of cloricromene (30 mg i.v.). CPT caused a higher increase in ET-1 in the patients with PAA compared to the control group, and a reduction in the vascular flow at the femoral level, while the pretreatment with cloricromene prevented both the increase in the levels of ET-1 and the reduction of the femoral vascular flow observed after the cold stimulus in patients with PAA. Our data show that cloricromene, besides ameliorating the microcirculatory function, is able to interfere with dynamic mechanisms, such as those induced by the CPT, capable of stimulating the release of ET-1 at the vascular level.

Thrombolytic therapy with urokinase reduces increased circulating endothelial adhesion molecules in acute myocardial infarction

The aim was to investigate circulating E-selectin and Intercellular Adhesion Molecule-1 (ICAM-1) in acute myocardial infarction. Our study was carried out in 80 patients, 40 hospitalized for acute myocardial infarction (AMI), 20 suffering from chronic stable angina and 20 healthy control subjects. Samples of venous blood were taken from all patients at the moment of hospitalization and after 2, 4, 6, 8, 10, 12 and 24 hours from the thrombolytic treatment (AMI + urokinase) or conventional therapy (AMI + nitroglycerin), for the dosage of creatinine kinase (CK) and adhesion molecules. The CK was determined by means of a Hitachi 901 automatic analyser using an enzymatic method (reagents Boheringer-Biochemia, Germany). Soluble E-selectin (sE-selectin) and soluble ICAM-1 (sICAM-1) were measured in the serum using a specific immunoassay (British Biotechnology Products). The serum levels of Tumor Necrosis Factor (TNF-alpha) were evaluated using an immunoenzymatic assay to quantitate the serum levels of the cytokine (British Biotechnology Products). Patients with acute myocardial infarction (AMI) had increased serum levels of soluble E-selectin (sE-selectin; AMI + urokinase = 312 +/- 20 ng/ml; AMI + nitroglycerin = 334 +/- 15 ng/ml) and soluble ICAM-1 (sICAM-1; AMI + urokinase = 629 +/- 30 ng/ml; AMI + nitroglycerin = 655 +/- 25 ng/ml) compared to both patients with chronic angina (sE-selectin = 67 +/- 10 ng/ml; sICAM-1 = 230 +/- 20 ng/ml) and healthy control subjects (sE-selectin = 53 +/- 15 ng/ml; sICAM-1 200 +/- 16 ng/ml). Furthermore patients with acute myocardial infarction also had increased serum levels of Tumor Necrosis Factor (TNF-alpha = 309 +/- 10 pg/ml; control subjects = 13 +/- 5 pg/ml). Thrombolytic therapy with urokinase (1,000,000 IU as an intravenous bolus for 5 minutes, followed by an infusion of an additional 1,000,000 IU for the following two hours) succeeded in producing reperfusion and reduced the serum levels of sE-selectin (52 +/- 13 ng/ml) and sICAM-1 (202 +/- 31 ng/ml). In contrast patients not eligible for thrombolytic therapy and therefore treated with conventional therapy (a continuous i.v. infusion of nitroglycerin at the dose of 50 mg/die) did not show any significant reduction in both sE-selectin and sICAM-1 throughout the study. Our results confirm previous experimental data and indicate that adhesion mechanisms supporting leukocyte-endothelium interaction may also be operative in human acute myocardial infarction.

G 619, a dual thromboxane synthase inhibitor and thromboxane A2 receptor antagonist, inhibits tumor necrosis factor-alpha biosynthesis

G 619 is 3-carbamyl-(3'-picolyl)-4-methoxy-1-benzamide. The compound is structurally related to picotamide, a previously reported dual thromboxane synthase inhibitor/thromboxane A2 receptor antagonist, which displays inhibitory activity on tumor necrosis factor-alpha. The aim of the present work was to study the effect of G 619 on tumor necrosis factor-alpha synthesis both in vivo and in vitro. Salmonella enteritidis lipopolysaccharide was used to induce tumor necrosis factor-alpha production. Septic shock was produced in male rats by a single intravenous (i.v.) injection of 20 mg/kg (LD90) of Salmonella enteritidis lipopolysaccharide. Rats were pretreated with G 619 (50 mg/kg, i.v.) or vehicle (1 ml/kg, i.v.) 1 h before endotoxin challenge. Salmonella enteritidis lipopolysaccharide administration dramatically reduced survival rate (0%, 72 h after endotoxin administration), reduced mean arterial blood pressure, increased plasma levels of thromboxane B2 and 6-keto-prostaglandin F1 alpha and enhanced serum levels of tumor necrosis factor. Furthermore, endotoxic shock produced characteristic gastric damage, consisting of haemorrhagic infiltrates. Pretreatment with G 619 in vivo significantly protected against Salmonella enteritidis lipopolysaccharide-induced lethality (80% survival rate and 60% survival rate 24 h and 72 h after Salmonella enteritidis lipopolysaccharide injection, respectively), reduced hypotension, decreased plasma thromboxane B2 and serum tumor necrosis factor-alpha levels and enhanced blood levels of 6-keto-prostaglandin F1 alpha. In rat peritoneal macrophages, G 619 in vitro (25, 50 and 100 microM) significantly blunted (P < 0.001) Salmonella enteritidis lipopolysaccharide-stimulated production of tumor necrosis factor-alpha, whereas it increased 6-keto-prostaglandin F1 alpha and cyclic AMP levels. The present data indicate that G 619 may be useful during disease states characterized by elevated tumor necrosis factor-alpha levels.

Improved survival and reversal of endothelial dysfunction by the 21-aminosteroid, U-74389G in splanchnic ischaemia-reperfusion injury in the rat

1. Anaesthetized rats subjected to total occlusion of the superior mesenteric artery and the coeliac trunk for 45 min developed a severe shock state (splanchnic artery occlusion, SAO shock) resulting in death within 70-90 min after release of the occlusion. Sham-operated animals were used as controls. 2. Survival rate, survival time, serum tumour necrosis factor (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure (MAP), plasma malonyladehyde (MAL); myeloperoxidase activity (MPO) and the responsiveness to acetylcholine (ACh 10 nM-10 microM) of aortic rings were investigated. 3. SAO shocked rats had a decreased survival rate and survival time (74 +/- 10 min, while sham-shocked rats survived more than 4 h), reduced mean arterial blood pressure, increased serum levels of TNF-alpha (267 +/- 13 u ml-1) and plasma levels of MAL (57 +/- 7 nmol ml-1), enhanced MPO activity in the ileum (0.23 +/- 0.04 u x 10(-3) g-1 tissue) and in the lung (2.2 +/- 0.8 u x 10(-3) g-1 tissue), leukopenia and reduced responsiveness to ACh of aortic rings. 4. The 21-aminosteroid U-74389G (30 mg kg-1, i.v.) increased survival (survival time = 232 +/- 15 min), lowered the serum levels of TNF-alpha and the plasma levels of MAL, reduced leukopenia and MPO activity both in the ileum (0.021 +/- 0.004 u x 10(-3) g-1 tissue) and in the lung (0.23 +/- 0.03 u x 10(-3) g-1 tissue), improved MAP and restored the responsiveness to ACh of aortic rings. 5. Our data suggest that U-74389G is a potent lipid peroxidation inhibitor and that it has antishock and endothelial protective actions.

Tumour necrosis factor mediates E-selectin production and leukocyte accumulation in myocardial ischaemia-reperfusion injury

The aim of our study was to examine the mechanism of E-selectin production and leukocyte accumulation in myocardial ischaemia-reperfusion injury. Myocardial injury was induced in anaesthetized rats by the clamping of the left main coronary artery followed by reperfusion. After thoracotomy a silk suture was placed under the left coronary artery. The ligature was tied for a period of 1 h and after this period it was untied and the ischaemic myocardium was reperfused for 1 h (MI/R rats) or removed (SHAM MI/R rats). Myocardial ischaemia plus reperfusion in untreated rats decreased survival rate, produced a marked myocardial necrosis, enhanced cardiac myeloperoxidase activity (a marker enzyme commonly used to assess polymorphonuclear leukocyte infiltration) and increased serum creatinephosphokinase (CPK) activity, serum levels of tumour necrosis factor-alpha (TNF-alpha) and serum levels of soluble E-selectin (sE-selectin). Furthermore, MI/R rats had an increased pressure rate index studied as a quantitative means for assessing myocardial oxygen demand. Administration of cloricromene, an inhibitor of TNF-alpha, reduced TNF-alpha production, significantly lowered serum sE-selectin levels, blunted leukocyte accumulation in the ischaemic myocardium and protected the myocardium from injury due to ischaemia and reperfusion. The results of the present study show an involvement of E-selectin in vivo in the pathogenesis of myocardial ischaemia and reperfusion and suggest that TNF-alpha may induce in vivo the production of a specific adhesion mechanism which sustains leukocyte infiltration.

Tumor necrosis factor induces E-selectin production in splanchnic artery occlusion shock

Splanchnic arteries were clamped for 45 min to induce splanchnic artery occlusion (SAO) shock in anesthetized rats. Sham-operated animals were used as controls. Survival time, serum tumor necrosis factor-alpha (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure, myeloperoxidase (MPO) activity, and serum levels of soluble E-selectin (sE-selectin) were investigated. SAO-shocked rats exhibited decreased survival time (95 +/- 11 min, whereas sham-shocked rats survived for > 5 h), reduced mean arterial blood pressure, increased serum levels of TNF-alpha (185 +/- 8 U/ml) and MPO activity in the ileum (0.11 +/- 0.03 U x 10(-3)/g tissue) and lung (1.5 +/- 0.4 U x 10(-3)/g tissue), leukopenia, and enhanced serum levels of sE-selectin. Furthermore SAO-shocked rats showed histological alterations in the ileum and lung. Administration of cloricromene (2 mg/kg i.v.), an inhibitor of TNF-alpha, significantly increased survival time (225 +/- 10 min), decreased serum levels of TNF-alpha and sE-selectin, reduced leukopenia and MPO activity in the ileum (0.035 +/- 0.003 U x 10(-3)/g tissue) and lung (0.3 +/- 0.005 U x 10(-3)/g tissue), improved the cardiovascular changes, and reduced the histological changes in the ileum and lung. Finally, an anti-E-selectin antibody protected rats against SAO shock. Our findings are consistent with an involvement of E-selectin, "in vivo," in the pathogenesis of SAO shock.

Soluble E-selectin levels in acute human myocardial infarction

It has been suggested that leukocyte adhesion mechanisms play a key role in experimental myocardial infarction. We have recently shown that E-selectin, an adhesion molecule belonging to the selectin family, is involved in the pathogenesis of experimental myocardial ischemia. We investigated the circulating levels of E-selectin, studied as a marker of endothelial dysfunction, in acute myocardial infarction. Our study was carried out in 60 patients, 20 hospitalized for acute myocardial infarction, 20 suffered from angina pectoris and 20 healthy control subjects. Patients with acute myocardial infarction had increased serum levels of soluble E-selectin (sE-selectin = 255 +/- 12 ng/ml) compared to both patients with angina pectoris (sE-selectin = 51 +/- 14 ng/ml). Thrombolytic therapy with urokinase (1,000,000 IU as an intravenous bolus in 5 min, followed by producing reperfusion and reduced the serum levels of sE-selectin (71 +/- 19 ng/ml). Our results confirm previous experimental data and indicate that adhesion mechanisms supporting leukocyte-endothelium interaction may also be operative in human acute myocardial infarction.

E-selectin involvement in the pathogenesis of splanchnic artery occlusion shock

We investigated the involvement of E-selectin in the pathogenesis of splanchnic artery occlusion shock. Splanchnic artery occlusion shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min. Sham-operated animals were used as controls. Survival time, serum tumor necrosis factor-alpha, while blood cell count, mean arterial blood pressure and myeloperoxidase activity were determined. Splanchnic artery occlusion-shocked rats had a decreased survival time (85 +/- 8 min, while sham-shocked rats survived more than 4 h), reduced mean arterial blood pressure, increased serum levels of tumor necrosis factor-alpha (186 +/- 9 U/ml) and myeloperoxidase activity in the ileum (0.10 +/- 0.04 U x 10(-3)/g tissue) and in the lung (1.5 +/- 0.06 U x 10(-3)/g tissue). Shocked rats showed histological alterations in the ileum and in the lung. Administration of a hyperimmune serum containing specific antibodies raised against E-selectin significantly increased survival time (225 +/- 10 min), reduced leukopenia and myeloperoxidase activity both in the ileum (0.035 +/- 0.001 U x 10(-3)/g tissue) and in the lung (0.3 +/- 0.005 U x 10(-3)/g tissue), improved the cardiovascular changes and reduced the histological alterations in the ileum and lung. Our data are consistent with an involvement of E-selectin in the pathogenesis of splanchnic artery occlusion shock.

Beneficial effects of BAY u3405, a novel thromboxane A2 receptor antagonist, in splanchnic artery occlusion shock

Splanchnic artery occlusion shock was induced in male anaesthetized rats by clamping the splanchnic artery for 45 min. The arteries were then released and survival rate, mean survival time, mean arterial blood pressure, plasma levels of thromboxane B2 and 6-keto-PGF1 alpha, macrophage phagocytosis activity and plasma levels of myocardial depressant factor were evaluated. In addition, the neutrophilic infiltrate was quantified in the ileum and lung using a myeloperoxidase (MPO) assay. Sham splanchnic-artery-occlusion-shocked rats were used as controls. Splanchnic-artery-occlusion-shocked rats died within 93 +/- 7 min, while all sham-shocked animals survived more than 3 h. Splanchnic artery occlusion shock caused changes in mean arterial blood pressure, significantly increased the plasma levels of thromboxane B2 (7.5 +/- 1.3 ng/ml; p < 0.001 vs. sham), 6-keto-PGF1 alpha (8.9 +/- 1.7 ng/ml; p < 0.001 vs. sham) and myocardial depressant factor (114 +/- 11 U/ml), and reduced macrophage phagocytosis. Furthermore, MPO activity was significantly elevated (0.12 +/- 0.03 x 10(-3) and 1.8 +/- 0.5 x 10(-3) U/g protein in the ileum and lung, respectively) 70 min after starting reperfusion. Administration of BAY u3405, a novel thromboxane A2 receptor antagonist (30 mg/kg i.v., 30 min before occlusion), significantly increased survival time (187 +/- 3.7 min) and survival rate, improved mean arterial blood pressure, reduced the plasma levels of myocardial depressant factor (54 +/- 3 U/ml), partially restored macrophage phagocytosis and lowered MPO activity in both the ileum and the lung. Our data are consistent with an involvement of thromboxane A2 in splanchnic artery occlusion shock and suggest that BAY u3405 might be of benefit in low-flow states such as circulatory shock.

Participation of tumour necrosis factor and nitric oxide in the mediation of vascular dysfunction in splanchnic artery occlusion shock

1. Splanchnic artery occlusion (SAO) shock is characterized by irreversible circulatory failure. Tumour necrosis factor (TNF-alpha) may affect the L-arginine/nitric oxide (NO) pathway, thus contributing to the cardiovascular derangements of circulatory shock. 2. We investigated the contribution of both TNF-alpha and the L-arginine/nitric oxide pathway to the vascular dysfunction of SAO shock. Anaesthetized rats, subjected to total occlusion of the superior mesenteric artery and the coeliac trunk for 45 min developed a severe shock state (SAO shock) resulting in a fatal outcome within 75-90 min after the release of occlusion. Sham operated animals were used as controls. SAO shocked rats had also a marked hypotension and enhanced macrophage and serum levels of TNF-alpha. Furthermore, aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE 1 nM-10 microM) and reduced responsiveness to acetylcholine (ACh 10 nM-10 microM). Endothelium-denuded aortic rings had also a marked hyporeactivity to phenylephrine, which was restored to control values by in vitro administration of NG nitro-L-arginine-methyl ester (L-NAME 10 microM). 3. In vivo administration of cloricromene (2 mg kg-1, i.v.), an inhibitor of TNF-alpha biosynthesis, increased survival, enhanced mean arterial blood pressure and reduced macrophage and serum levels of TNF-alpha. Furthermore, aortic rings from shocked rats treated with cloricromene exhibited a greater contractile response to phenylephrine and improved responsiveness to ACh when compared to aortic rings from vehicle-treated SAO shocked rats. 4. Our results suggest that TNF-alpha alters both endothelial and muscular L-arginine/nitric oxide pathways which in turn produce vascular dysfunction in SAO shock.

Contribution of intercellular adhesion molecule 1 (ICAM-1) to the pathogenesis of splanchnic artery occlusion shock in the rat

1. It has been suggested that leukocytes play a key role in the pathogenesis of splanchnic artery occlusion shock. Intercellular adhesion molecule 1 (ICAM-1) is an adhesion molecule of crucial importance in the phenomenon of leukocyte accumulation. 2. We investigated the involvement of ICAM-1 in the pathogenesis of splanchnic artery occlusion shock. Splanchnic artery occlusion (SAO) shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min. Sham-operated animals were used as controls. Survival time, serum tumour necrosis factor-alpha (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure, myeloperoxidase activity (MPO; studied as a quantitative means to assess leukocyte accumulation) and the responsiveness to acetylcholine of aortic rings were investigated. SAO shocked rats had a decreased survival time (90 +/- 9.5 min, while sham-shocked rats survived more than 4 h), reduced mean arterial blood pressure, increased serum levels of TNF-alpha (201 +/- 10 mu ml-1) and MPO activity in the ileum (0.15 +/- 0.03 mu x 10(-3) per g tissue) and in the lung (1.9 +/- 0.8 mu x 10(-3) per g tissue), leukopenia and reduced responsiveness to acetylcholine (ACh, 10 nM-10 microM) of aortic rings. 3. Administration of monoclonal antibody raised against rat ICAM-1 significantly increased survival time (225 +/- 9 min), reduced leukopenia and MPO activity both in the ileum (0.031 +/- 0.003 mu x 10(-3) per g tissue) and in the lung 0.23 +/- 0.03 mu x 10(-3) per g tissue), improved the cardiovascular changes and restored the responsiveness to ACh of aortic rings. 4. Our findings are consistent with an involvement of adhesion mechanisms in vivo in the pathogenesis of SAO shock and suggest that specific adhesion mechanisms, which support leukocyte accumulation,may represent potentially important therapeutic targets in circulatory shock.

Antibodies against intercellular adhesion molecule 1 protect against myocardial ischaemia-reperfusion injury in rat

In this study we have assayed the pathophysiological role of intercellular adhesion molecule (ICAM-1), a cytokine-inducible adhesion molecule, in a model of ischaemia reperfusion in the rat. Anaesthetized rats were subjected to occlusion (1 h) of the left main coronary artery followed by reperfusion (1 h). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial ischaemia plus reperfusion in untreated rats decreased survival rate, produced a marked myocardial necrosis, increased serum creatine phosphokinase activity, and cardiac myeloperoxidase activity (a marker enzyme commonly used to assess polymorphonuclear leukocyte accumulation). Furthermore, rats subjected to myocardial ischaemia-reperfusion showed an increased pressure rate index, studied as a quantitative means for assessing myocardial oxygen demand. Treatment with monoclonal anti-rat ICAM-1 (1 mg/kg i.v.), 3 h before occlusion of the left main coronary artery, significantly lowered serum creatine phosphokinase activity, blunted leukocyte accumulation and protected the myocardium from injury subsequent to ischaemia and reperfusion injury. These investigations have revealed that ICAM-1 is a critical adhesion molecule in the pathogenesis of ischaemia-reperfusion injury. In addition these results suggest that the use of monoclonal antibodies raised against ICAM-1 can represent a useful tool for the prevention of ischaemia-reperfusion damage.

TCV-309, a novel platelet activating factor antagonist, inhibits leukocyte accumulation and protects against splanchnic artery occlusion shock

The aim of this study was to evaluate: (1) the accumulation of leukocytes in the ileum and the lung during splanchnic artery occlusion (SAO) shock; (2) the role of platelet-activating factor (PAF) and tumor necrosis factor (TNF-alpha) in this phenomenon. Untreated anesthesized rats subjected to total occlusion of the celiac, superior and inferior mesenteric arteries for 45 min, followed by reperfusion, uniformly died within 90 min after reperfusion. The mean survival time was 93 +/- 7 min. The neutrophilic infiltrate was quantitated in the ileum and in the lung using a myeloperoxidase (MPO) assay. MPO activity in the ileum and in the lung averaged 0.05 +/- 0.03 and 0.4 +/- 0.02 U x 10(-3)/g protein in animals killed before occlusion. MPO activity did not change in rats killed immediately before reperfusion and was significantly elevated (0.11 +/- 0.02 and 1.7 +/- 0.6 U x 10(-3)/g protein in the ileum and the lung, respectively) in those killed 80 min after the beginning of the reperfusion. The histological examination confirmed the accumulation of leukocytes in the mucosa of the ileum and the lung over the 80 min. SAO shocked rats exhibited leukopenia and increased serum levels of TNF-alpha. In order to evaluate the role of PAF and TNF-alpha in SAO shock, a powerful PAF receptor antagonist, TCV-309 (5 micrograms/kg i.v.), was injected 5 min after reperfusion. TCV-309 increased survival time, lowered serum TNF-alpha, reduced MPO activity in both the ileum and the lung and ameliorated leukopenia induced by SAO shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effects of BAY U 3405, a thromboxane A2 receptor antagonist, in endotoxin shock

The present study was designed to investigate the effects of BAY U 3405, a new thromboxane A2 (TxA2) receptor antagonist, in endotoxin shock. Endotoxin shock (ES) was induced in male rats by an i.v. injection of Salmonella enteritidis lipopolysaccharide (LPS; 20 mg kg-1). LPS administration caused animal death (survival = 0%, 48 h after endotoxin challenge), systemic hypotension, depressed phagocytosis and increased blood levels of TNF-alpha, TxB2 and 6-keto-PGF1 alpha, reduced white blood cell (WBC) count (ES = 5.9 +/- 1 x 10(3) mm-3; CTRL = 13.4 +/- 5 x 10(3) mm-3) and enhanced myeloperoxidase (MPO) activity, studied as a quantitative means for assessing leukocyte accumulation, in the ileum (ES = 0.24 +/- 0.7 U g-1 fresh tissue; CTRL = 0.13 +/- 0.04 U g-1 fresh tissue), in the heart (ES = 0.41 +/- 0.1 U g-1 fresh tissue; CTRL = 0.16 +/- 0.08 U g-1 fresh tissue) and in the lung (ES = 0.68 +/- 0.11 U g-1 fresh tissue; CTRL = 0.19 +/- 0.05 U g-1 fresh tissue). Furthermore, endotoxin administration produced characteristic damage of the gastric mucosa consisting of haemmorrhagic infiltrates. BAY U 3405 (30 mg kg-1 i.v., 30 min before endotoxin challenge) increased survival rate (45% survival rate 48 h after endotoxin challenge), reduced hypotension, decreased TNF-alpha levels in serum, enhanced phagocytic activity (ES = 25.6 +/- 1.9%, BAY U 3405 = 45.9 +/- 0.4%, P < 0.001) and lowered MPO activity in the ileum (0.14 +/- 0.05 U g-1 fresh tissue), in the heart (0.18 +/- 0.08 U g-1 fresh tissue) and in the lung (0.44 +/- 0.09 U g-1 fresh tissue). Finally, the gastric alterations were significantly reduced in rats pretreated with BAY U 3405. These data suggest that this thromboxane receptor antagonist might be a useful drug in shock conditions.

Evidence for a role of platelet activating factor in hypovolemic shock in the rat

An extremely severe circulatory shock was produced in two different manners in urethane-anaesthetized rats in order to evaluate the key role of platelet-activating factor (PAF) and myocardial depressant factor (MDF) in low flow states. Haemorrhagic shock was induced by intermittently withdrawing about 50% of the estimated blood volume until mean arterial blood pressure (MAP) stabilized in the range of 20-25 mmHg. Vehicle-treated shocked rats died within 20-30 min after the last bleeding and exhibited elevated plasma activity of MDF (159.6 +/- 7.4 U/ml). Treatment with a specific PAF receptor antagonist, L-659,989, at doses of 500 or 1000 nmol/kg i.v., significantly increased survival rate, blunted the rise in plasma MDF activity and maintained MAP at higher values compared to vehicle shocked rats. Similarly, in another group of rats PAF (15 nmol/kg, i.v.) produced a shock-like state characterized by a serious hypotension in the range of 20-30 mmHg, elevated plasma MDF activity (79.7 +/- 7,7 U/ml) and death within 20-25 min after administration. L-659,989, given 5 min after the PAF-induced sharp decrease of MAP, improved survival rate, ameliorated MAP and reduced plasma levels of MDF. The results of this study, therefore, confirm that PAF plays a role in cardiovascular changes of hypovolemic circulatory shock both directly and by inducing the release of other factors such as MDF.

E-selectin in the pathogenesis of experimental myocardial ischemia-reperfusion injury

The role of E-selectin in the pathogenesis of an experimental model of myocardial ischemia-reperfusion injury was investigated. Pentobarbital anesthetized rats underwent left main coronary artery ligation (1 h) followed by reperfusion (1 h; MI/R). Sham operated rats were used as controls (sham MI/R). Myocardial ischemia-reperfusion injury reduced survival rate (50%), caused severe myocardial damage (necrotic area/area-at-risk 69.8 +/- 5%; necrotic area/total area = 56 +/- 7.6%), increased serum creatine phosphokinase activity (sham MI/R = 33 +/- 3 U/ml; MI/R = 215 +/- 13 U/ml), and elevated myeloperoxidase activity (investigated as an index of leukocyte adhesion and accumulation; sham MI/R = 0.11 +/- 0.02 U x 10(-3)/g tissue) in the area-at-risk (7.5 +/- 1.7 U x 10(-3)/g tissue) and in the necrotic area (7.8 +/- 2.2 U x 10(-3)/g tissue). Furthermore, MI/R rats had an increased pressure rate index, studied as a quantitative means for assessing myocardial oxygen demand. Administration of a hyperimmune serum containing antibodies against E-selectin significantly improved survival rate (80%), reduced myocardial injury (necrotic area/area-at-risk = 26.4 +/- 7%, P < 0.005; necrotic area/total area 19.1 +/- 2.8%, P < 0.005), lowered serum creatine phospokinase activity (85 +/- 5 U/ml, P < 0.001) and decreased myeloperoxidase activity in the area at risk (3.7 +/- 1.3 U x 10(-3)/g tissue, P < 0.001) and in the necrotic area (3.0 +/- 0.7 U x 10(-3)/g tissue). Finally, the administration of anti E-selectin antibodies improved the PRI in MI/R rats. The present data suggest that E-selectin in vivo plays a key role in the pathogenesis of myocardial ischemia/reperfusion injury.

Protective effects of L-659,989, a platelet-activating factor receptor antagonist, in myocardial ischemia and reperfusion in rats

The cardioprotective effects of L-659,989, a specific platelet-activating factor (PAF) receptor antagonist, were investigated in an ischemia/reperfusion model in rats. Pentobarbital-anesthetized rats were subjected to left main coronary artery occlusion (1 h) followed by reperfusion (1 h) (MI/R); Sham-operated rats were used as controls (Sham MI/R). Rats receiving vehicle showed reduced survival rate (60%), marked myocardial injury (necrotic area/total area = 54.5 +/- 6%; necrotic area/area at risk 76.6 +/- 6.7%), high serum creatine phosphokinase (CPK) activity (150 +/- 10 U/ml), and increased myocardial myeloperoxidase (MPO) activity in the area at risk (AR, 6.2 +/- 0.5 U x 10(-3)/g protein) and in the necrotic area (6.6 +/- 0.7 U x 10(-3)/g protein). PAF plasma levels increased significantly during reperfusion and peaked at 15 min of reperfusion. Administration of L-659,989 enhanced survival rate (80%), reduced myocardial damage (necrotic area/total area 25.6 +/- 3.5%; necrotic area/AR 34.6 +/- 5.4%), attenuated the increase in serum CPK (50 +/- 6 U/ml) and decreased MPO activity both in the AR (2.8 +/- 0.3 U x 10(-3)/g tissue) and in the necrotic area (2.3 +/- 0.5 U x 10(-3)/g tissue). Our results suggest that PAF-inducing adhesion and activation of polymorphonuclear leukocytes (PMN) plays a significant role in the injury associated with ischemia/reperfusion.

G619, a dual thromboxane synthase inhibitor and thromboxane A2 receptor antagonist, reduces myocardial damage and polymorphonuclear leukocyte accumulation following coronary artery occlusion and reperfusion in rats

We investigated the effect of G 619, a dual thromboxane synthase inhibitor and thromboxane A2 (TxA2) receptor antagonist, in pentobarbital-anaesthetized rats subjected to left main coronary artery ligation (1 h) followed by reperfusion (1 h; MI/R). Sham-operated rats were used as controls (sham MI/R). Survival rate, myocardial necrosis, myocardial myeloperoxidase (MPO) activity (investigated as an index of leukocyte adhesion and accumulation) and serum creatine phosphokinase (CPK) activity were studied. MI/R injury significantly reduced survival rate (45%), caused a marked myocardial necrosis, increased serum CPK activity (sham MI/R = 35 +/- 12 U/ml; MI/R = 205 +/- 13 U/ml) and produced an increase in myocardial MPO activity in the area at risk and in the necrotic area (6.3 +/- 0.5 and 6.6 +/- 0.9 U x 10(-3)/g tissue, respectively). The administration of G 619 significantly increased survival rate, lowered the area of necrosis, blunted the increase in serum CPK activity and reduced the increase in MPO activity in both the area at risk and the necrotic area. These data are consistent with an involvement of TxA2 in MI/R injury and suggest that G 619 may represent a novel therapeutic approach to the treatment of acute myocardial infarction.

Platelet activating factor interaction with tumor necrosis factor in myocardial ischaemia-reperfusion injury

The role played by platelet-activating factor (PAF) and tumor necrosis factor (TNF-alpha) in myocardial ischaemia-reperfusion injury was investigated. Pentobarbital anaesthetized rats were subjected to left main coronary artery ligation (1 h) followed by reperfusion (1 h; MI/R). Sham-operated rats were used as controls (Sham MI/R). Myocardial ischaemia-reperfusion injury produced a marked myocardial injury (necrotic area/area-at-risk = 60 +/- 5%; necrotic area/total area = 50 +/- 6%), high serum creatine phosphokinase activity (Sham MI/R = 25 +/- 10 U/ml; MI/R = 190 +/- 12 U/ml), a severe leukopenia (Sham MI/R = 10367 +/- 630 WBC x mm3; MI/R = 4123 +/- 120 WBC x mm3) and elevated myocardial myeloperoxidase activity (investigated as an index of leukocytes adhesion and accumulation) in the area-at-risk (6.2 +/- 0.5 U x 10(-3)/g tissue) and in necrotic area (6.6 +/- 0.7 U x 10(-3)/g tissue. Plasma PAF and serum TNF-alpha were significantly increased only during reperfusion. The peak of PAF plasma levels (6.5 +/- 1.2 pmol/ml) occurred earlier (15 min of reperfusion) than the peak of serum TNF-alpha (150 U/ml at 30 min of reperfusion). At the end of reperfusion, macrophage TNF-alpha was also enhanced (Sham MI/R = undetectable; MI/R = 148 +/- 12 U/ml). The administration of CV 6209, a specific PAF receptor antagonist (5 mg/kg, 5 min after occlusion), significantly reduced myocardial injury (necrotic area/area-at-risk = 27 +/- 3%, P < 0.001; necrotic area/total area = 10 +/- 2%, P < 0.001), blunted the increase in serum creatine phosphokinase (70 +/- 12 U/ml), partially restored leukopenia (8234 +/- 143 WBC x mm3) and lowered myeloperoxidase activity in area-at-risk (2.3 +/- 0.3 U x 10(-3)/g tissue; P < 0.001) and in necrotic area (2.8 +/- 0.5 U x 10(-3)/g tissue). In addition, administration of CV 6209 reduced the serum and macrophage levels of TNF-alpha. The results of this study, therefore, suggest that PAF and TNF-alpha are key mediators of myocardial ischaemia-reperfusion injury and that PAF plays a permissive role in inducing the release of other factor(s) relevant to reperfusion injury.

Reduction of myocardial leukocyte accumulation and myocardial infarct size following administration of BAY u3405, a thromboxane A2 receptor antagonist, in myocardial ischaemia-reperfusion injury

We investigated the effect of BAY u3405, a thromboxane A2 receptor antagonist in pentobarbital anaesthetized rats subjected to left main coronary artery ligation (1 h) followed by reperfusion (1 h; MI/R). Sham operated rats were used as controls (Sham MI/R). Survival rate, myocardial necrosis, myocardial myeloperoxidase activity (investigated as an index of leukocyte adhesion and accumulation) and serum creatine phosphokinase activity were studied. Ischaemia-reperfusion injury significantly reduced the survival rate (45%), caused a marked myocardial necrosis, increased serum creatine phosphokinase activity (Sham MI/R = 26 +/- 10.2 U/ml; MI/R = 213 +/- 19 U/ml) and produced a rise in myocardial myeloperoxidase activity in the area-at-risk and in the necrotic area (6.1 +/- 0.4 U x 10(-3)/g tissue and 6.7 +/- 0.9 U x 10(-3)/g of tissue, respectively). The administration of BAY u3405 (30 and 60 mg/kg/i.v., 30 min before occlusion) significantly increased survival rate, lowered the area of myocardial necrosis, blunted the increase in serum creatine phosphokinase activity and reduced the increase in myeloperoxidase activity in both the area-at-risk and the necrotic area. Furthermore, the protective effect of BAY u3405 was dose-dependent. These data are consistent with an involvement of TXA2 in myocardial ischaemia-reperfusion injury and suggest that BAY u3405 may represent a novel therapeutic approach to the treatment of acute ischaemia-reperfusion injury.

Splanchnic artery occlusion shock: vinblastine-induced leukopenia reduces tumour necrosis factor and thromboxane A2 formation, and increases survival rate

This study was designed to assess the role of leukocytes in rats subjected to splanchnic artery occlusion for 45 min followed by reperfusion (SAO shock). Leukopenia was induced by an intravenous injection of vinblastine (1 mg/kg) 72 h before SAO shock. Survival rate (within 6 h), plasma levels of thromboxane B2 (TxB2), serum levels of tumour necrosis factor (TNF-alpha), and histological alteration of the intestinal tract were investigated. Control rats [white blood cells (WBC) = 10362 +/- 630/mm3] died within 2 h following ischaemia and reperfusion. Leukopenic (WBC = 1263 +/- 311/mm3) animals which underwent SAO shock survived more than 2 h and 50% of them were still alive after 6 h. Plasma TxB2 levels significantly increased in WBC count normal rats subjected to SAO shock (8.4 +/- 2.1 ng/ml), compared to sham animals (0.4 +/- 0.08 ng/ml); however SAO shock raised TxB2 levels significantly less (2.1 +/- 1.1 ng/ml) in leukopenic rats. Serum TNF-alpha, undetectable in sham-shocked rats (either with normal WBC count or without), rose up to 150 +/- 12 U/ml in shocked rate and to 45 +/- 5 U/ml (P < 0.01) in shocked animals with leukopenia. SAO shock induced a massive necrosis of the intestinal tract in rats with normal WBC count. Leukopenia prevented ileum necrosis in SAO shock. These data indicate that leukocytes play an important role in splanchnic artery occlusion and reperfusion.

Timolol--further observations

Data from clinical records of patients using timolol confirm the ocular hypotensive effect of the drug in secondary glaucoma, aphakic glaucoma, ocular hypertension, and when used in combination with various other forms of glaucoma therapy. No serious local or systemic side effects were noted. Although many adrenergic agents ultimately produce tachyphylaxis, this effect is infrequent in timolol therapy.