High Incidence of Respiratory Involvement in a Cluster of Brucella suis-Infected Workers from a Pork Processing Plant in Argentina.

Epidemiological and clinical aspects of Brucella suis infection in 17 workers from a pork processing plant in Argentina occurring between January 2014 and July 2015 are presented. All patients reported working 9 h daily without adequate personal protection garment. Blood cultures were positive for Brucella spp. in 14 of the 17 patients (82.3%). All isolates were identified as B. suis biovar 1. Although fever, sweats, asthenia, myalgia and hepatic involvement were the most frequent clinical manifestations, an unusually high incidence of respiratory involvement was found. From 13 patients in which chest radiography was performed, four (30%) had radiological abnormalities, including lobar pneumonia in two cases (one with pleural effusion) and interstitial involvement in other two. The high frequency of respiratory involvement in our series makes necessary to consider brucellosis in the differential diagnosis of respiratory diseases in pork processing plant employees.

Adeno-associated viral vector-mediated human vascular endothelial growth factor gene transfer stimulates angiogenesis and wound healing in the genetically diabetic mouse.

AIMS/HYPOTHESIS: We studied the gene therapy efficacy of diabetes-associated wound healing disorder with an adeno-associated virus (AAV) vector expressing the 165-amino acid isoform of human vascular endothelial growth factor-A (VEGF-A) by using an incisional skin-wound model produced on the back of female diabetic C57BL/KsJ db+/db+ mice and their normal littermates ( db+/+m). METHODS: Animals were randomized to receive intradermally into the wound edges either rAAV-LacZ (a control gene), or rAAV-VEGF165. Animals were killed on different days (7 and 14 days after skin injury) and wounded skin tissues were used for gene marker studies, histological evaluation and immunohistochemistry, and wound breaking strength analysis. Furthermore we studied the VEGF mature protein in the wounds. RESULTS: We found that AAV vectors are highly efficient for gene transfer to the mouse skin, displaying an exquisite tropism for the panniculus carnosus by using the beta-galactosidase activity assay. We confirmed the increased expression of the angiogenic factor at day 7 by measuring the wound content of the mature protein. Delivery of VEGF165 to incisional skin wounds of diabetic mice resulted in a remarkable induction of new vessel formation with consequent improvement in the wound healing process. The rAAV-VEGF165 gene improved wound healing in diabetic mice through the stimulation of angiogenesis, reepithelization, synthesis and maturation of extracellular matrix. Moreover the recombinant AAV encoding the human VEGF165 increased the breaking strength of the wound and enhanced the wound content of VEGF. CONCLUSION/INTERPRETATION: Our study suggests that VEGF gene transfer might represent a new approach to treat wound healing disorders associated with diabetes.

Recombinant AAV vector encoding human VEGF165 enhances wound healing.

Delivery of therapeutic genes represents an appealing possibility to accelerate healing of wounds that are otherwise difficult to treat, such as those in patients with metabolic disorders or infections. Experimental evidence indicates that in such conditions potentiation of neo-angiogenesis at the wound site might represent an important therapeutic target. Here we explore the efficacy of gene therapy of wound healing with an adeno-associated virus (AAV) vector expressing the 165 amino acid isoform of vascular endothelial growth factor-A (VEGF-A). By gene marker studies, we found that AAV vectors are highly efficient for gene transfer to the rat skin, displaying an exquisite tropism for the panniculus carnosus. Gene expression from these vectors is sustained and persistent over time. Delivery of VEGF165 to full thickness excisional wounds in rats resulted in remarkable induction of new vessel formation, with consequent reduction of the healing time. Histological examination of treated wounds revealed accelerated remodeling of epidermis and dermis, with formation of a thick granular layer, containing numerous newly formed capillaries, as well as vessels of larger size. These data underline the importance of neo-angiogenesis in the healing process and indicate that VEGF gene transfer might represent a novel approach to treat wound healing disorders.

[Dengue imported from Paraguay to Buenos Aires. Clinical and epidemiological report of 38 cases]. / Dengue importado del Paraguay a Buenos Aires. Estudio clinico y epidemiologico de 38 casos.

Thirty eight patients with classic dengue fever, were studied from December 1999 up to April 2000. All of them acquired the infection in Paraguay; 66% of patients arrived at Buenos Aires metropolitan area within the viremia period. Given Aedes aegypti abundance in the region they represent a high risk for local transmission. Unusual clinical findings in these patients were diarrhea (29%), transitory rise of seric aspartate aminotransferase (52%) and pruritic rash in all cases. Only 15.7% showed a biphasic course and none of the five patients with hemorrhages had a positive loop test. These observations show that dengue fever could be misdiagnosed as gastroenteritis or flue-like illness. These patients remain at risk of suffering hemorrhagic dengue. DEN 1 has not been reported in Buenos Aires. This fact and the unusual number of imported cases, represent a serious public health problem.

Raxofelast, a hydrophilic vitamin E-like antioxidant, stimulates wound healing in genetically diabetic mice.

BACKGROUND: Impaired wound healing is a well-documented phenomenon in experimental and clinical diabetes. Emerging evidence favors the involvement of free radicals in the pathogenesis of diabetes-related healing deficit. This study assessed the effect of systemic administration of raxofelast, a protective membrane antioxidant agent, on wound healing by using healing-impaired (db/db) mice. METHODS: The wound healing effect of raxofelast was investigated by using an incisional skin-wound model produced on the back of female diabetic C57BL/KsJ db+/db+ mice and their healthy littermates (db+/+m). Animals were then randomized to the following treatment: raxofelast (15 mg/kg/d intraperitoneally) or its vehicle (dimethyl sulfoxide/sodium chloride 0.9%, 1:1, vol/vol). The animals were killed on different days, and the wounded skin tissues were used for histologic evaluation and for analysis of malondialdehyde (MDA) level and myeloperoxidase (MPO) activity, wound breaking strength, and collagen content. RESULTS: Diabetic mice showed delayed wound healing together with low collagen content, breaking strength, and increased MDA levels and MPO activity when compared with their healthy littermates. The administration of raxofelast did not modify the process of wound repair in healthy (db/+) mice, but significantly improved impaired wound healing in diabetic mice through the stimulation of angiogenesis, reepithelialization, synthesis, and maturation of extracellular matrix. Furthermore, raxofelast treatment significantly reduced MDA levels, MPO activity, and increased the breaking strength and collagen content of the wound. CONCLUSIONS: The current study provides evidence that raxofelast restores wound healing to nearly normal levels in experimental diabetes-impaired wounds and suggests that an increased lipid peroxidation in diabetic mice may have a role in determining a defect of wound repair.

The phytoestrogen alpha-zearalenol reverses endothelial dysfunction induced by oophorectomy in rats.

It has been shown recently that alpha-zearalenol, a resorcyclic acid lactone, prevents bone loss in a rat model of postmenopausal bone loss. We have therefore investigated the effects of this phytoestrogen on endothelial dysfunction induced by estrogen deficiency in rats. Female mature Sprague-Dawley rats underwent a bilateral oophorectomy (OVX rats). Sham-operated animals (sham OVX rats) were used as controls. Three weeks after surgery, animals were randomized to the following treatments: alpha-zearalenol (1 mg/kg/day, i.m., for 4 weeks), 17beta-estradiol (20 microg/kg/day, i.m., for 4 weeks), or their vehicle (100 microl, i.m., of cottonseed oil). Two other groups of rats were treated with alpha-zearalenol or 17beta-estradiol plus the pure estrogen receptor antagonist ICI 182780 (2.5 mg/kg/day, i.m., for 4 weeks). Mean arterial blood pressure (MAP), heart rate (HR), total plasma cholesterol, plasma estradiol, and plasma alpha-zearalenol were studied. We also investigated endothelial-dependent (acetylcholine, 10 nM to 10 microM) and endothelial-independent (sodium nitroprusside, 15 nM to 30 nM) relaxation of aortic rings, as well as N(G)-methyl-L-arginine (L-NMA: 10 to 100 microM)-induced vasoconstriction and calcium-dependent nitric oxide synthase (cNOS) activity in homogenates of lungs taken from both sham OVX rats and OVX rats. Untreated OVX rats had, compared with sham OVX animals, unchanged body weight, MAP, HR, and plasma cholesterol. In contrast oophorectomy reduced plasma estradiol levels (OVX, 2 +/- 0.5 pg/ml; sham OVX, 35 +/- 6 pg/ml), impaired endothelial-dependent relaxation and blunted L-NMA-induced contraction (L-NMA 100 microM: sham OVX, 2.7 +/- 0.3 g/mg tissue; OVX, 1.3 +/- 0.1 g/mg tissue). Moreover OVX rats showed a reduced calcium-dependent NO synthase (cNOS) activity. Treatment with alpha-zearalenol or with 17beta-estradiol reverted the endothelial dysfunction and increased cNOS activity in lung homogenates. These effects were abolished by the pure estrogen receptor antagonist ICI 182780. Our data suggest that alpha-zearalenol improves endothelial-dependent relaxation in OVX rats through an estrogen receptor-mediated effect.

Inhibition of lipid peroxidation restores impaired vascular endothelial growth factor expression and stimulates wound healing and angiogenesis in the genetically diabetic mouse.

Impaired wound healing is a well-documented phenomenon in experimental and clinical diabetes. Experimental evidence suggests that a defect in vascular endothelial growth factor (VEGF) regulation might be associated with wound-healing disorders. We studied the involvement of lipid peroxidation in the pathogenesis of altered VEGF expression in diabetes-related healing deficit by using an incisional skin-wound model produced on the back of female diabetic C57BL/KsJ db+/ db+ mice and their normal (db+/+m) littermates. Animals were then randomized to the following treatment: raxofelast (15 mg.kg(-1).day(-1) i.p.), an inhibitor of lipid peroxidation, or its vehicle (DMSO/NaCl 0.9%, 1:1 vol: vol). The animals were killed on different days (3, 6, and 12 days after skin injury), and the wounded skin tissues were used for histological evaluation, for analysis of conjugated dienes (CDs), as an index of lipid peroxidation and wound breaking strength. Furthermore, we studied the time course of VEGF mRNA expression throughout the skin-repair process (3, 6, and 12 days after skin injury), by means of reverse transcriptase-polymerase chain reaction, as well as the mature protein in the wounds. Diabetic mice showed impaired wound healing with delayed angiogenesis, low breaking strength, and increased wound CD content when compared with their normal littermates. In healthy control mice, a strong induction of VEGF mRNA was found between day 3 and day 6 after injury, while no significant VEGF mRNA expression was observed at day 12 after injury. In contrast, VEGF mRNA levels, after an initial increase (day 3), were significantly lower in diabetic mice than in normal littermates, and light induction of VEGF mRNA expression was also present at day 12 after injury. Similarly, the wound content of the angiogenic factor was markedly changed in diabetic mice. Administration of raxofelast did not modify the process of wound repair in normal mice, but significantly improved the impaired wound healing in diabetic mice through the stimulation of angiogenesis, re-epithelization, and synthesis and maturation of extracellular matrix. Moreover, raxofelast treatment significantly reduced wound CD levels and increased the breaking strength of the wound. Lastly, the inhibition of lipid peroxidation restored the defect in VEGF expression during the process of skin repair in diabetic mice and normalized the VEGF wound content. The current study provides evidence that lipid peroxidation inhibition restores wound healing to nearly normal levels in experimental diabetes-impaired wounds and normalizes the defect in VEGF regulation associated with diabetes-induced skin-repair disorders.

Dengue importado del Paraguay a Buenos Aires. Estudio clinico y epidemiologico de 38 casos. / [Dengue imported from Paraguay to Buenos Aires. Clinical and epidemiological report of 38 cases]

Thirty eight patients with classic dengue fever, were studied from December 1999 up to April 2000. All of them acquired the infection in Paraguay; 66

of patients arrived at Buenos Aires metropolitan area within the viremia period. Given Aedes aegypti abundance in the region they represent a high risk for local transmission. Unusual clinical findings in these patients were diarrhea (29

), transitory rise of seric aspartate aminotransferase (52

) and pruritic rash in all cases. Only 15.7

showed a biphasic course and none of the five patients with hemorrhages had a positive loop test. These observations show that dengue fever could be misdiagnosed as gastroenteritis or flue-like illness. These patients remain at risk of suffering hemorrhagic dengue. DEN 1 has not been reported in Buenos Aires. This fact and the unusual number of imported cases, represent a serious public health problem.

The reduction of myocardial damage and leukocyte polymorphonuclear accumulation following coronary artery occlusion by the tyrosine kinase inhibitor tyrphostin AG 556.

We investigated the effects of tyrophostin AG 556, a tyrosine kinase inhibitor, on the phenomenon of leukocyte accumulation during ischaemia and reperfusion of the myocardium. Male anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity (MPO), serum creatinine phosphokinase activity (CPK) serum Tumor Necrosis Factor (TNF-alpha) and Interleukin 6 (IL-6), cardiac intercellular adhesion molecule-1 (ICAM-1) and TNF-alpha expression and myocardial contractility (left ventricle dP/dt(max)) were evaluated. Myocardial ischaemia plus reperfusion in untreated rats produced marked myocardial necrosis, increased serum CPK activity (196.5 +/- 19 U/100 ml, at the end of reperfusion) and myeloperoxidase activity (MPO, a marker of leukocyte accumulation) both in the area-at-risk (4.5 +/- 0.5 U/g/tissue) and in necrotic area (8.2 +/- 1.2 U/g/tissue), reduced myocardial contractility (1,706 +/- 52 mmHg/s, at the end of reperfusion) and induced a marked increase in the serum levels of TNF-alpha (1,950 +/- 97 pg/ml, at 1 h of reperfusion) and IL-6 (998 +/- 16 U/ml, at the end of reperfusion). Finally, myocardial ischaemia-reperfusion injury also increased cardiac mRNA for TNF-alpha and ICAM-1 in the myocardium-at risk. Tyrphostin AG 556 (0.5, 1 and 2 mg/kg subcutaneously 5 min after the onset of reperfusion) lowered myocardial necrosis and myeloperoxidase activity in the area-at-risk (1.5 +/- 0.2 U/g/tissue, following the highest dose) and in necrotic area (2.9 +/- 0.3 U/g/tissue following the highest dose), decreased serum CPK activity (96 +/- 9 U/100 ml, at the end of reperfusion), lowered serum TNF-alpha and IL-6, increased myocardial contractility (2,096 +/- 88 mmHg s, at the end of reperfusion) and reduced cardiac mRNA levels for TNF-alpha and ICAM-1. The present data suggest that tyrosine kinase inhibitors protect against myocardial ischaemia-reperfusion injury by reducing leukocyte accumulation to the ischaemic myocardium.

IRFI 042, a novel dual vitamin E-like antioxidant, inhibits activation of nuclear factor-kappaB and reduces the inflammatory response in myocardial ischemia-reperfusion injury.

BACKGROUND: Nuclear factor-kappaB (NF-kappaB) is a ubiquitous rapid response transcription factor involved in inflammatory reactions which exerts its effect by expressing cytokines, chemokines, and cell adhesion molecules. Oxidative stress causes NF-kappaB activation. IRFI 042 is a novel dual vitamin E-like antioxidant and we, therefore, investigated its ability to protect the heart from oxidative stress and to halt the inflammatory response in a model of myocardial ischaemia-reperfusion injury. METHODS: Anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5-h reperfusion (MI/R). Sham myocardial ischaemia rats (sham-operated rats) were used as controls. Myocardial necrosis, cardiac output, cardiac and plasma vitamin E levels, myocardial malondialdehyde (MAL), cardiac SOD activity and elastase content (an index of leukocyte infiltration), hydroxyl radical (OH&z.ccirf;) formation, cardiac amount of mRNA codifying for ICAM-1 (evaluated by the means of reverse transcriptase polymerase chain reaction) and ICAM-1 immunostaining in the at-risk myocardium were investigated. NF-kappaB activation and the inhibitory protein of NF-kappaB, I-kappaBalpha, were also studied in at-risk myocardium by using electrophoretic mobility shift assay (EMSA) and Western blot analysis, respectively. RESULTS: The ischaemia-reperfusion model produced wide heart necrosis (area at risk-necrotic area=52+/-5%; necrotic area-left ventricle=28+/-3%), increased cardiac MAL, an index of lipid peroxidation (area at risk=62.5+/-3.9 nmol/g tissue; necrotic area=80.3+/-5.1 nmol/g tissue), induced tissue neutrophil infiltration, and caused a marked decrease in endogenous antioxidants. Furthermore, myocardial ischaemia plus reperfusion caused in the area at risk peak message for ICAM-1 at 3 h of reperfusion and increased cardiac ICAM-1 immunostaining at 5 h of reperfusion. NF-kappaB activation was also evident at 0.5 h of reperfusion and reached its maximum at 2 h of reperfusion. I-kappaBalpha was markedly decreased at 45 min of occlusion; peak reduction was observed at 1 h of reperfusion and thereafter it was gradually restored. Intraperitoneal administration of IRFI 042 (5, 10, 20 mg/kg, 5 min after reperfusion) reduced myocardial necrosis expressed as a percentage either of the area at risk (18+/-4%) or the total left ventricle (11+/-2%), and improved cardiac output. This treatment also limited membrane lipid peroxidation in the area at risk (MAL=14.3+/-2.5 nmol/g tissue) and in the necrotic area (MAL=26.5+/-3.7 nmol/g tissue), restored the endogenous antioxidants vitamin E and superoxide dismutase, and inhibited detrimental hydroxyl radical formation. Finally, IRFI 042 blocked the activation of NF-kappaB, reduced cardiac ICAM-1 expression, and blunted tissue elastase content, an index of leukocytes accumulation at the site of injury. CONCLUSIONS: Our data suggest that IRFI 042 is cardioprotective during myocardial infarction by limiting reperfusion-induced oxidative stress and by halting the inflammatory response.

Protective effects of cyclosporin-A in splanchnic artery occlusion shock.

Cyclosporin A (CsA) is an immunosuppressant drug that inhibits nitric oxide (NO) synthase induction in vascular smooth muscle cells. Splanchnic artery occlusion (SAO) shock is a lethal type of shock characterized by a marked vascular dysfunction in which the L-arginine/nitric oxide pathway plays an important role. We investigated whether CsA exerts protective effects in SAO shock by interfering with the L-arginine/nitric oxide pathway. Male anaesthetized rats (n=156) were subjected to clamping of the splanchnic arteries for 45 min. This surgical procedure resulted in an irreversible state of shock (SAO shock). Sham operated animals were used as controls. SAO shocked rats had a decreased survival (86+/-6 min, while sham shocked rats survived more than 240 min), marked hypotension, increased serum levels of TNF-alpha, enhanced plasma nitrite/nitrate concentrations (75+/-7.1 microM; sham shocked rats=1.6+/-0.5 microM) and enhanced inducible NO synthase (iNOS) protein induction and activity in the aorta. Moreover aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE, 1 nM - 10 microM). CsA (0.25, 0.5 and 1 mg kg(-1), 5 min after reperfusion) increased survival rate (SAO+CsA=236+/-9 min following the highest dose), reverted the marked hypotension, reduced plasma nitrite/nitrate concentration (11+/-5.2 microM following the highest dose), restored to control values the hyporeactivity to PE, and blunted iNOS protein induction and activity in aortic rings. The present data indicate that in an experimental rat model CsA may have antishock properties related to inhibition of L-arginine/nitric oxide pathway.

Tacrolimus limits polymorphonuclear leucocyte accumulation and protects against myocardial ischaemia- reperfusion injury.

Intercellular adhesion molecule-1 (ICAM-1) plays an important role in the pathogenesis of either human and experimental myocardial ischaemia. Tacrolimus, formerly known as FK506, has been previously shown to display cardioprotective effects on experimental ischaemia/reperfusion-induced myocardial damage. This study investigated whether cardioprotection induced by tacrolimus in myocardial ischaemia-reperfusion (MI/R) injury might be due to inhibition of the nuclear factor kappa B (NF- kappaB) that in turn causes reduced cardiac ICAM-1 expression and blunted polymorphonuclear leukocyte accumulation. Anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity, serum creatine kinase (CK) activity, cardiac mRNA for ICAM-1 reverse-transcriptase polymerase chain reaction, the inhibitory protein of NF- kappaB I kappaB alpha (Western blot analysis) in the myocardium-at-risk, and left ventricle d P/d t(max)were evaluated. Myocardial ischaemia plus reperfusion in untreated rats produced marked myocardial necrosis, increased serum CK activity and myeloperoxidase activity (MPO, a marker of leukocyte accumulation) both in the area at risk and in the necrotic area, and reduced the left ventricle dP/d t(max). Furthermore, inhibitory protein I kappaB alpha levels decreased, and cardiac mRNA for ICAM-1 increased, after 0.5 and 5 h of reperfusion, respectively. Administration of tacrolimus (25, 50 and 100microg/kg as an i.v. infusion 5 min after reperfusion) lowered myocardial necrosis and myeloperoxidase activity in the area at risk and in necrotic area, decreased serum CK activity, increased left ventricle dP/d t(max), reduced the loss the of inhibitory protein I kappaB alpha and blunted the message for ICAM-1. The present data suggest that tacrolimus blocks the early activation of the transcription factor NF- kappaB, suppresses ICAM-1 gene activation, reduces leukocyte accumulation and protects against myocardial ischaemia-reperfusion injury.

Genistein supplementation and estrogen replacement therapy improve endothelial dysfunction induced by ovariectomy in rats.

BACKGROUND: We investigated the effect of genistein, a phytoestrogen derived from a soy diet with a flavonoid chemical structure, on endothelial dysfunction induced by estrogen deficiency in rats. METHODS: Female mature Sprague-Dawley rats were subjected to a bilateral ovariectomy (OVX rats). Sham-operated animals (Sham OVX rats) were used as controls. Three weeks after surgery animals were randomized to the following treatments: genistein (0.2 mg/kg/day, s.c. for 4 weeks), 17 beta-estradiol (20 micrograms/kg/day, s.c. for 4 weeks) or their respective vehicles. Mean arterial blood pressure (MAP), heart rate (HR), total plasma cholesterol, plasma estradiol, plasma genistein levels and uterine weights were studied. Furthermore, we investigated acetylcholine (ACh 10 nM-10 microM) and sodium nitroprusside: (SN 15-30 nM) induced relaxation of aortic rings as well as NG-L-arginine (L-NMA: 10-100 microM) induced vasoconstriction in phenylephrine precontracted aortic segments and calcium-dependent nitric oxide synthase (cNOS) activity in homogenates of lungs taken from both sham OVX and OVX rats. RESULTS: Untreated OVX rats had, compared with sham OVX animals, unchanged body weight, MAP, HR and plasma cholesterol. In contrast ovariectomy impaired endothelial responses, blunted L-NMA induced contraction (L-NMA 100 microM: Sham OVX = 2.1 +/- 0.2 g/mg tissue; OVX = 1.7 +/- 0.4 g/mg tissue) and reduced cNOS activity. Treatment with 17 beta-estradiol increased the hormone plasma levels, reverted the endothelial dysfunction and increased cNOS activity in lung homogenates. Genistein supplementation enhanced the circulating levels of the phytoestrogen and affected NOS activity and endothelial dysfunction to the same extent. CONCLUSIONS: Our data suggest that genistein and 17 beta-estradiol show overlapping effects on experimental endothelial dysfunction.

Cardioprotection by the phytoestrogen genistein in experimental myocardial ischaemia-reperfusion injury.

1. Soybean phytoestrogens have no oestrogen agonist effects on the reproductive system and therefore it is reasonable to explore the potential of these naturally occurring plant oestrogens in the cardiovascular pathology. We therefore investigated the effects of genistein in a rat model of myocardial ischaemia-reperfusion injury. 2. Anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham operated rats were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity (MPO), serum creatinine phosphokinase activity (CPK), serum and macrophage Tumour Necrosis Factor-alpha (TNF-alpha), cardiac intercellular adhesion molecule-1 (ICAM-1) immunostaining, cardiac mRNA for ICAM-1 evaluated by the means of reverse transcriptase polymerase chain reaction (RT - PCR), ventricular arrhythmias and myocardial contractility (left ventricle dP/dt(max)) were evaluated. 3. Myocardial ischaemia and reperfusion in untreated rats produced marked myocardial necrosis, increased serum CPK activity and MPO activity both in the area-at-risk and in the necrotic area, reduced myocardial contractility, caused ventricular arrhythmias and induced a marked increase in serum and macrophage TNF-alpha. Furthermore myocardial ischaemia-reperfusion injury increased ICAM-1 expression in the myocardium. 4. Administration of genistein (1 mg kg(-1), i.v., 5 min after coronary artery occlusion) lowered myocardial necrosis and MPO activity in the area-at-risk and in the necrotic area, decreased serum CPK activity, increased myocardial contractility, decreased the occurrence of ventricular arrhythmias, reduced serum and macrophages levels of TNF-alpha and blunted ICAM-1 expression in the injured myocardium. Finally genistein added in vitro to peritoneal macrophages collected from untreated rats subjected to myocardial ischaemia-reperfusion injury significantly reduced TNF-alpha production. 5. Our data suggest that genistein limits the inflammatory response and protects against myocardial ischaemia-reperfusion injury.

Differentiation of pathogenic and non-pathogenic leptospires by means of the polymerase chain reaction.

A polymerase chain reaction was carried out to detect pathogenic leptospires isolated from animals and humans in Argentina. A double set of primers (G1/G2, B64-I/B64-II), described before, were used to amplify by PCR a DNA fragment from serogroups belonging to Leptospira interrogans but did not allow to detect saprophytic strains isolated from soil and water (L. biflexa). This fact represents an advantage since it makes possible the differentiation of pathogenic from non-pathogenic leptospires in cultures. The sensitivity of this assay has been determined, allowing to detect just only 10 leptospires in the reaction tube. Those sets of primers generated either a 285 bp or 360 bp fragment, depending on the pathogenic strain.

[Cross-reactivity between Chlamydia psittaci and Acinetobacter in indirect immunofluorescence assays]. / Reactividad cruzada entre Chlamydia psittaci y Acinetobacter en ensayos de inmunofluorescencia indirecta.

Cross reactivity between Chlamydia psittaci and a strain from genus Acinetobacter was investigated by indirect fluorescent antibody (IFA) technique. Two groups of serum samples were tested: 64 belonged to patients diagnosed as psittacosis and 64 (control group) were non reactive to Chlamydia psittaci by IFA. Samples were incubated on smears prepared with an Acinetobacter suspension for detecting IgG and IgM. 100% reactivity to IgG was found in 1:16 serum dilution among anti-psittacosis sera, whereas 6.25% of control sera reacted at the same dilution. When testing IgM, high rates of reactivity were found in both serum groups, thus it has been discarded as a marker for cross reactivity. Fluorescence pattern suggests that antigens are located at the cell wall.