Endothelial ILK induces cardioprotection by preventing coronary microvascular dysfunction and endothelial-to-mesenchymal transition

Endothelial dysfunction is an early event in coronary microvascular disease. Integrin-linked kinase (ILK) prevents endothelial nitric oxide synthase (eNOS) uncoupling and, thus, endothelial dysfunction. However, the specific role of endothelial ILK in cardiac function remains to be fully elucidated. We hypothesised that endothelial ILK plays a crucial role in maintaining coronary microvascular function and contractile performance in the heart. We generated an endothelial cell-specific ILK conditional knock-out mouse (ecILK cKO) and investigated cardiovascular function. Coronary endothelial ILK deletion significantly impaired cardiac function: ejection fraction, fractional shortening and cardiac output decreased, whilst left ventricle diastolic internal diameter decreased and E/A and E/E' ratios increased, indicating not only systolic but also diastolic dysfunction. The functional data correlated with extensive extracellular matrix remodelling and perivascular fibrosis, indicative of adverse cardiac remodelling. Mice with endothelial ILK deletion suffered early ischaemic-like events with ST elevation and transient increases in cardiac troponins, which correlated with fibrotic remodelling. In addition, ecILK cKO mice exhibited many features of coronary microvascular disease: reduced cardiac perfusion, impaired coronary flow reserve and arterial remodelling with patent epicardial coronary arteries. Moreover, endothelial ILK deletion induced a moderate increase in blood pressure, but the antihypertensive drug Losartan did not affect microvascular remodelling whilst only partially ameliorated fibrotic remodelling. The plasma miRNA profile reveals endothelial-to-mesenchymal transition (endMT) as an upregulated pathway in endothelial ILK conditional KO mice. Our results show that endothelial cells in the microvasculature in endothelial ILK conditional KO mice underwent endMT. Moreover, endothelial cells isolated from these mice and ILK-silenced human microvascular endothelial cells underwent endMT, indicating that decreased endothelial ILK contributes directly to this endothelial phenotype shift. Our results identify ILK as a crucial regulator of microvascular endothelial homeostasis. Endothelial ILK prevents microvascular dysfunction and cardiac remodelling, contributing to the maintenance of the endothelial cell phenotype.

RIP2 plays a role in cardiac Ca2+ mishandling prompted by chronic kidney disease

Background

Chronic kidney disease (CKD) is a multifaceted disease that contributes to cardiac dysfunction. However, the mechanisms underlying the complex relationship between CKD and cardiac impairment remains almost completely unknown. Inflammation is a major player in both CKD and cardiovascular disease (CVD) and, in this context, nucleotide-binding oligomerization domain-containing protein 1 (NOD1) is a newly recognized innate immune receptor involved in both CKD and CVD independently. NOD1 activation is due to the recruitment of the receptor-interacting-serine/threonine-protein kinase 2 (RIP2), which induce NOD1 oligomerization and promotes the inflammatory response, being RIP2 a key partner in the NOD1 activation. Unpublished data from our group has demonstrated that genetic deletion of NOD1 prevents Ca2+ mishandling associated to CKD, next step will be to determine whether the absence of its specific adaptor; RIP2 can also mediate these effects.

Purpose

The main aim of this study was to determine whether NOD1-RIP2 axis impairs cardiac dysfunction and Ca2+ mishandling prompted by CKD induced by 5/6 nephrectomy (5/6Nx) in a mice model.

Methods and results

We have analysed intracellular Ca2+ handling in cardiomyocytes obtained from Wild type (Wt), Nod1−/− and Rip2−/− sham operated or nephrectomised mice. Compared with Wt-5/6Nx, cardiomyocytes obtained from Nod1−/−5/6Nx and Rip2−/−5/6Nx mice showed a significant improvement of Ca2+ mishandling, mainly by preventing: i) the reduction in [Ca2+]i transients amplitude; ii) the rise in their decay time; and iii) the lower cell contraction. The lack of NOD1 and RIP2 also prevents the reduced sarcoplasmic reticulum (SR) Ca2+ load and the augmented diastolic Ca2+ leak induced by 5/6Nx. Furthermore, the increased diastolic Ca2+ leak (Ca2+ sparks, spontaneous [Ca2+]i transients and waves) induced by 5/6Nx were also significantly prevented in absence of NOD1 and RIP2. Genetic deletion of NOD1 or RIP2 did not induces any improvement of several markers associated with renal dysfunction (urea, phosphate or fibroblast growth factor-23).

Conclusions

Our results confirmed that the absence of both NOD1 and RIP2 prevents the intracellular cardiac Ca2+ mishandling in experimental CKD. NOD1 and RIP2 emerge as novel targets for the development of innovative therapeutic strategies for the cardiac remodelling in CKD subjects.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported by Spanish ISCIII (PI17/01093 and PI17/01344), Fondo Europeo de Desarrollo Regional (FEDER), FSE, and CIBER-CV, a network funded by ISCIII. MF-V is Miguel Servet II researcher of ISCIII (MSII16/00047 Carlos III Health Institute). GR-H is Miguel Servet I researcher of ISCIII (CP15/00129 Carlos III Health Institute). MT is a PhD student funded by the FPU program of the Spanish Ministry of Science, Innovation and Universities (FPU17/06135).

Bisphenol A induces coronary endothelial cell necroptosis by activating RIP3/CamKII dependent pathway

Epidemiological studies link long term exposure to xenoestrogen Bisphenol-A to adverse cardiovascular effects. Our previous results show that BPA induces hypertension by a mechanism involving CamKII activation and increased redox stress caused by eNOS uncoupling. Recently, CamKII sustained activation has been recognized as a central mediator of programmed cell death in cardiovascular diseases, including necroptosis. However, the role of necroptosis in cardiac response to BPA had not yet been explored. Mice exposed to BPA for 16 weeks showed altered heart function, electrical conduction, and increased blood pressure. Besides, a stress test showed ST-segment depression, indicative of cardiac ischemia. The hearts exhibited cardiac hypertrophy and reduced vascularization, interstitial edema, and large hemorrhagic foci accompanied by fibrinogen deposits. BPA initiated a cardiac inflammatory response, up-regulation of M1 macrophage polarization, and increased oxidative stress, coinciding with the increased expression of CamKII and the necroptotic effector RIP3. In addition, cell death was especially evident in coronary endothelial cells within hemorrhagic areas, and Evans blue extravasation indicated a vascular leak in response to Bisphenol-A. Consistent with the in vivo findings, BPA increased the necroptosis/apoptosis ratio, the expression of RIP3, and CamKII activation in endothelial cells. Necrostatin-1, an inhibitor of necroptosis, alleviated BPA induced cardiac dysfunction and prevented the inflammatory and hemorrhagic response in mice. Mechanistically, silencing of RIP3 reversed BPA-induced necroptosis and CamKII activation in endothelial cells, while inhibition of CamKII activation by KN-93 had no effect on RIP3 expression but decreased necroptotic cell death suggesting that BPA induced necroptosis is mediated by a RIP 3/CamKII dependent pathway. Our results reveal a novel pathogenic role of BPA on the coronary circulation. BPA induces endothelial cell necroptosis, promotes the weakening of coronary vascular wall, which caused internal ventricular hemorrhages, delaying the reparative process and ultimately leading to cardiac dysfunction.

Effects of Oral Prednisone Administration on Serum Cystatin C in Dogs

Background

Oral administration of glucocorticoid alters serum cystatin C (sCysC) concentration in humans.

Objective

To determine if oral administration of prednisone alters sCysC in dogs without pre‐existing renal disease.

Animals

Forty six dogs were included: 10 dogs diagnosed with steroid responsive meningitis arteritis (SRMA; group A), 20 dogs diagnosed of pituitary‐dependent hyperadrenocorticism (PDH; group B), and 16 healthy control dogs (group C).

Methods

Retrospective observational study. SRMA diagnosed dogs were administered prednisone 4 mg/kg/24 h PO 7 days, reducing the dose to 2 mg/kg/24 h 7 days before medication withdrawal. In group A, sampling was performed at days 0, 7, 14 and a final control at day 21. Blood and urine samples were collected in the 3 groups, and in group A, sampling was performed at all time points (days 1, 7, 14, and 21).

Results

In group A, sCysC was significantly higher at day 7 compared to the control group (0.4 ± 0.04 mg/L vs. 0.18 ± 0.03 mg/L mean ± SEM respectively P < 0.01); sCysC values decreased to basal at day 14 when the dose was decreased and after 1 week of withdrawal of prednisone (0.27 ± 0.03 mg/L for group A at day 14 and 0.15 ± 0.02 mg/L at day 21; P > 0.05). Dogs with PDH included in group B did not have significant differences in sCysC (0.22 ± 0.03 mg/L) compared to control (P > 0.05).

Conclusions and Clinical Importance

Oral administration of prednisone unlike altered endogenous glucocorticoid production, increases sCysC in dogs in a dose‐dependent fashion.

Two unusual cases of canine prostatitis: prostatitis in a castrated dog and preputial oedema in an intact male

In this study, two unusual presentations of canine prostatitis are described; in the first case a 10-years-old neutered Boxer dog was presented to the Veterinary Teaching Hospital of the University of Extremadura with a complaint of anorexia, apathy and preputial discharge. In the second case, a local veterinarian referred an 8-years-old male Labrador to the Veterinary Teaching Hospital of the University of Extremadura. The dog had a history of pain in the caudal abdomen and preputial oedema. The final diagnosis in both cases was acute prostatitis. It is concluded that although canine prostatitis is a common disease, sometimes can have presentations that may differ from those classically described in the literature.

Native and oxidized low density lipoproteins oppositely modulate the effects of insulin-like growth factor I on VSMC

OBJECTIVE

Changes in the local expression and signaling activity of the insulin-like growth factor-I (IGF-I) axis regulate growth and survival of plaque-derived vascular smooth muscle cells (VSMC) and influence plaque fate. Recent evidence suggests that accumulation of low density lipoproteins (LDL) in VSMC during the progression of atherogenesis is linked to local changes in IGF-I signaling. We investigated the effects of LDL on the biological actions and downstream signaling pathways mediated by this growth factor in A10 VSMC.

METHODS AND RESULTS

We first characterized the effects of LDL on the proliferative and anti-apoptotic actions of IGF-I in A10 VSMC. Native LDL were mitogenic and synergistically enhanced DNA synthesis induced by IGF-I from 4-, 9- up to 7.8-fold, while having no effect on its anti-apoptotic actions. In contrast, oxidized LDL, at oxidation levels that did not modify these actions by themselves, significantly reduced the mitogenic and survival effects of IGF-I by 40% and 60%, respectively. These observations correlated with opposite changes exerted by native and oxidized LDL on the insulin receptor substrate-1 (IRS)-associated PI3 kinase/Akt response to IGF-I. The extracellular signal-regulated kinase (ERK) signaling response was not affected.

CONCLUSIONS

Our study demonstrates a previously unidentified modulation of the actions of IGF-I on A10 VSMC by LDL, dependent on their extent of oxidative modification. Our findings suggest that the differential modulation of the PI3 kinase/Akt response to IGF-I play a pivotal role.

Canine pyometra: a study of the urinary proteins by SDS–PAGE and Western blot

Canine pyometra often causes glomerulonephritis by immune complex deposition in the glomeruli. Proteinuria, ranging from moderate to severe, may be present secondary to renal damage. To determine urinary protein excretion due to pyometra, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was conducted on urine from 15 bitches with pyometra and 10 healthy bitches. To characterize urinary immunoglobin excretion, Western blot analysis of the urine samples using antibodies to canine IgG and IgA was also performed. Nine bands were detected by electrophoresis in bitches with pyometra, while only four were detected in the healthy animals. The urinary proteins from bitches with pyometra were primarily of glomerular origin; 58% were of medium-high molecular weight (MW), and the remainder were low MW. None of the healthy dogs had IgG or IgA in their urine, whereas three bitches with pyometra had IgG in their urine and another bitch with pyometra had both IgG and IgA. The low proportion of bitches with urinary immunoglobins was probably be due to early diagnosis of the disease. Although only a limited number of dogs was used, this study is apparently the first to characterize the electrophoretic pattern of urinary proteins and to quantify urinary excretion of IgG and IgA in bitches with pyometra.

Cardiovascular morbidity and obesity in adult liver transplant recipients

There is a direct relationship between the grade of obesity and mortality based on the increased cardiovascular diseases, cancer, etc. However, the results of studies in renal and liver allograft recipients relating obesity to morbidity and mortality are contradictory. A retrospective cohort study of 170 patients transplanted between March 1987 and July 1997 showed obesity to be identified in 77 (45.3%) patients. During the mean follow-up of 5 years posttransplantation, 16 (9.4%) patients experienced cardiovascular complications, including 10 patients with ischemic cardiac syndromes (five acute infarctions and five angina), five patients with acute cerebrovascular accidents, and one patient with intermittent lower limbs claudication. The prevalence of obesity at 1, 3, 5, 7, and 9 years after transplantation was 58.2%, 56.9%, 60.3%, 59.5%, and 66.4%, respectively. Compared with the baseline value, the BMI was increased at 1 year posttransplantation (25.78), a significant difference. No significant differences were found between the mean BMI values of patients with and without cardiovascular diseases, or overweight and morbidly obese patients compared to the normal weight population. Among liver transplant recipients, obesity was a frequent complication after transplantation, but it was not clearly associated with increased morbidity and mortality secondary to cardiovascular disease.

Characterization of renal damage in canine leptospirosis by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting of the urinary proteins

Canine leptospirosis is a zoonotic disease that can cause interstitial nephritis. As a consequence of the renal damage, proteinuria may occur. To determine the urine protein pattern in the disease we performed sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) on the urine from 10 dogs with leptospirosis and 20 healthy dogs. Western blotting analysis of the urine samples with antibodies against canine IgG and IgA was also performed to identify these immunoglobulins in the urine. Urine electrophoresis showed three new bands in the dogs suffering from leptospirosis. Only two of the dogs with leptospirosis showed detectable concentrations of IgG and IgA in urine, while a third animal showed IgG alone. The study showed a 36.7% increase in the excretion of low molecular weight proteins in dogs with leptospirosis but almost no change in the high molecular weight protein pattern. These results, together with the low number of animal with detectable concentrations of IgG and IgA in the urine, support the view that canine leptospirosis is characterized by interstitial nephritis.

Biotypes resistant to herbicides in paddy fields in the Iberian Peninsula

A consequence of modern agriculture and its dependence on herbicides, is the appearance of resistant weed populations. The first case of resistance on the Iberian Peninsula was found in Portugal and it was in a population of Alisma plantago-aquatica, resistant to bensulfuronmethyl, an ALS-inhibitor. For the same herbicide, control problems with Cyperus difformis were found in some Spanish rice fields. In the same rice field area, tolerance was observed in some Echinochloa spp. when auxinic herbicides (quinclorac) were used and some resistant Echinochloa spp. populations were found due to the long use of PS II inhibitors herbicides (propanil). The association of active ingredients, rotation of crops and adoption of mechanical control methods are the main strategies to combat resistance to herbicides.

Hydrogen peroxide regulation of bovine endothelin-converting enzyme-1

Vascular injury leads to the production of reactive oxygen species (ROS), but the mechanisms by which ROS contribute to vascular pathology are not completely understood. We hypothesized that ROS increase endothelin converting enzyme (ECE-1) expression. We found that glucose oxidase (GO) increases ECE-1 mRNA, protein, and activity in bovine aortic endothelial cells. Catalase abolishes this effect. Glucose oxidase treatment of endothelial cells transactivates the ECE-1 promoter. The ECE-1 promoter element that mediates this response to GO is located between -444 and -216 bp. This region contains a STAT response element, and GO activates STAT-3 binding to this STAT response element. Our data suggest that STAT3 mediates hydrogen peroxide induction of ECE-1 expression.

Superoxide regulation of endothelin-converting enzyme

Reactive oxygen species (ROS) act as signaling molecules in the cardiovascular system, regulating cellular proliferation and migration. However, an excess of ROS can damage cells and alter endothelial cell function. We hypothesized that endogenous mechanisms protect the vasculature from excess levels of ROS. We now show that superoxide can inhibit endothelin-converting enzyme activity (ECE) and decrease endothelin-1 synthesis. Superoxide inhibits ECE but hydrogen peroxide and nitric oxide do not. Superoxide inhibits ECE by ejecting zinc from the enzyme, and the addition of exogenous zinc restores enzymatic activity. Superoxide may inhibit other zinc metalloproteinases by a similar mechanism and may thus play an important role in regulating the biology of blood vessels.

Inducible nitric oxide synthase protection against coxsackievirus pancreatitis

Coxsackievirus infection causes myocarditis and pancreatitis in humans. In certain strains of mice, Coxsackievirus causes a severe pancreatitis. We explored the role of NO in the host immune response to viral pancreatitis. Coxsackievirus replicates to higher titers in mice lacking NO synthase 2 (NOS2) than in wild-type mice, with particularly high viral titers and viral RNA levels in the pancreas. Mice lacking NOS have a severe, necrotizing pancreatitis, with elevated pancreatic enzymes in the blood and necrotic acinar cells. Lack of NOS2 leads to a rapid increase in the mortality of infected mice. Thus, NOS2 is a critical component in the immune response to Coxsackievirus infection.

Interaction of interferon regulatory factor-1 and nuclear factor kappaB during activation of inducible nitric oxide synthase transcription

We investigated the molecular mechanism for the synergistic induction of inducible nitric oxide synthase transcription by TNF-alpha and IFN-gamma. Since TNF-alpha and IFN-gamma stimulate cells in part by activating NF-kappaB and IRF-1, we hypothesized that these two transcription factors interact with each other. IRF-1 and NF-kappaB co-localize in the nucleus of stimulated macrophages. Co-immunoprecipitation experiments show that IRF-1 and NF-kappaB interact in stimulated but not resting cells. Super-shift experiments show that IRF-1 and NF-kappaB interact while binding to their respective DNA binding sites. These results demonstrate the existence of a physical interaction between IRF-1 and NF-kappaB proteins in vivo. We next suggested that this interaction between IRF-1 and NF-kappaB bends the DNA of the iNOS promoter region. Using a cyclization assay, we demonstrate that nuclear extracts from stimulated cells accelerate the rate of conversion of a linear to circular DNA, compared to extracts from resting cells. However, stimulated nuclear extracts cannot affect the rate of cyclization of a promoter with a mutant IRE or kappaB site. Furthermore, stimulated nuclear extracts depleted of IRF-1 and NF-kappaB cannot induce cyclization. We conclude that IRF-1 and NF-kappaB interact in vivo, and that this interaction physically bends the indicible nitric oxide synthase promoter DNA. This interaction may explain the mechanism by which IFN-gamma synergistically augments inducible nitric oxide synthase transcription.

An antiviral mechanism of nitric oxide: inhibition of a viral protease

Although nitric oxide (NO) kills or inhibits the replication of a variety of intracellular pathogens, the antimicrobial mechanisms of NO are unknown. Here, we identify a viral protease as a target of NO. The life cycle of many viruses depends upon viral proteases that cleave viral polyproteins into individual polypeptides. NO inactivates the Coxsackievirus protease 3C, an enzyme necessary for the replication of Coxsackievirus. NO S-nitrosylates the cysteine residue in the active site of protease 3C, inhibiting protease activity and interrupting the viral life cycle. Substituting a serine residue for the active site cysteine renders protease 3C resistant to NO inhibition. Since cysteine proteases are critical for virulence or replication of many viruses, bacteria, and parasites, S-nitrosylation of pathogen cysteine proteases may be a general mechanism of antimicrobial host defenses.

Impaired liver regeneration in inducible nitric oxide synthasedeficient mice

The mechanisms that permit adult tissues to regenerate when injured are not well understood. Initiation of liver regeneration requires the injury-related cytokines, tumor necrosis factor (TNF) alpha and interleukin (IL) 6, and involves the activation of cytokine-regulated transcription factors such as NF-kappabeta and STAT3. During regeneration, TNFalpha and IL-6 promote hepatocyte viability, as well as proliferation, because interventions that inhibit either cytokine not only block hepatocyte DNA synthesis, but also increase liver cell death. These observations suggest that the cytokines induce hepatoprotective factors in the regenerating liver. Given evidence that nitric oxide can prevent TNF-mediated activation of the pro-apoptotic protease caspase 3 and protect hepatocytes from cytokine-mediated death, cytokine-inducible nitric oxide synthase (iNOS) may be an important hepatoprotective factor in the regenerating liver. In support of this hypothesis we report that the hepatocyte proliferative response to partial liver resection is severely inhibited in transgenic mice with targeted disruption of the iNOS gene. Instead, partial hepatectomy is followed by increased caspase 3 activity, hepatocyte death, and liver failure, despite preserved induction of TNFalpha, IL-6, NF-kappabeta, and STAT3. These results suggest that during successful tissue regeneration, injury-related cytokines induce factors, such as iNOS and its product, NO, that protect surviving cells from cytokine-mediated death.

The role of inducible nitric oxide synthase in the host response to Coxsackievirus myocarditis

The host response to Coxsackievirus infection is complex, including T lymphocytes, B lymphocytes, natural killer cells, and macrophages. Although Coxsackievirus infection induces expression of inducible nitric oxide synthase (NOS2; EC 1.14.13.39) in macrophages, the precise role of NOS2 in the host response to Coxsackievirus myocarditis has been unclear. We show, by using mice homozygous for a disrupted NOS2 allele, that Coxsackievirus replicates to higher titers in NOS2(-/-) mice, that the host lacking NOS2 clears virus more slowly than the wild-type host, and that myocarditis is much more severe in infected NOS2(-/-) mice. These data show that NOS2 is crucial for the host response to Coxsackievirus in the mouse.

Involvement of transcriptional mechanisms in the inhibition of NOS2 expression by dexamethasone in rat mesangial cells

In previous studies we reported that stimulation of rat mesangial cells (RMC) with lipopolysaccharide (LPS) + tumor necrosis factor alpha (TNF-alpha) (L/T) elicits inducible nitric oxide synthase (NOS2) mRNA expression, which is inhibited by dexamethasone (DX). We have now analyzed the mechanisms responsible for this inhibitory effect. Dexamethasone had no destabilizing effect on NOS2 mRNA. Transfection of RMC with several luciferase reporter constructs from the 5' flanking regulatory region of the rat NOS2 gene established the importance of the NF-kappa B site in the transcriptional activation of the NOS2 gene. DNA mobility shift assays showed activation by L/T of the NF-kappa B complex in a time-dependent manner. Dexamethasone specifically inhibited this activation in a process dependent on the glucocorticoid receptor and with a markedly greater effect when it was added prior to L/T. Dexamethasone increased the expression of the I kappa B-alpha transcript and protein in the cytoplasm. While treatment of RMC with L/T induced the transient decrement of cytoplasmic p65 levels and its appearance in the nucleus, preincubation with DX prevented this effect. Co-immunoprecipitation and immunocytochemical studies demonstrated that I kappa B-alpha is associated with p65 in the cytoplasm of RMC after treatment with DX and L/T. These results prove that inhibition of NF-kappa B-mediated transcription is a crucial mechanism by which DX inhibits NOS2 expression, and that this occurs by increasing cytoplasmic I kappa B-alpha levels and sequestering the activating subunits of NF-kappa B in the cytoplasm. The need for previous induction of I kappa B-alpha could provide a molecular explanation for the limited efficacy of these agents in the therapy of septic shock.

Response to barium selenate supplementation in sheep kept at pasture in the Mediterranean area

This work evaluated the efficacy of barium selenate supplements in the prevention of disorders related to Se deficiency in sheep maintained at pasture in the Mediterranean area. Ewes on five farms were divided into two equal groups of 1,750 animals: a) the treated group and b) the control group. The animals of the treated group were injected subcutaneously, in the first third of gestation, with a barium selenate compound at a dose of 1 mg Se/kg. The ewes in the control group did not receive any supplement of Se and/or vitamin E. The two groups were managed under the same feeding and husbandry practices throughout the experiment. After lambing, blood glutathione peroxidase (GSHPx) and serum aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) activities were measured in the lambs born to both group. Blood GSHPx activity was higher in the treated animals, with statistically significant differences due to the response to injection of barium selenate. Mean global serum activities of AST and CK tended to be higher in the control group, as a consequence of the protection given to the treated group by the supplement, but the differences were not statistically significant. This was possibly due to the absence of clinical cases of nutritional myodystrophy (NMD) in the animals of the control group. Therefore it can be stated that barium selenate supplementation can prevent Se deficiency in sheep herds maintained at pasture in this area.

Nitric oxide inhibition of coxsackievirus replication in vitro

Nitric oxide is a radical molecule with antibacterial, -parasitic, and -viral properties. We investigated the mechanism of NO inhibition of Coxsackievirus B3 (CVB3) replication in vitro by determining the effect of NO upon a single replicative cycle of CVB3 grown in HeLa cells. Transfection of inducible NO synthase cDNA into HeLa cells reduces the number of viral particles produced during a single cycle of growth. Similarly, a noncytotoxic concentration of the NO donor S-nitroso-amino-penicillamine reduces the number of viral particles in a dose-dependent manner. To explore the mechanisms by which NO exerts its antiviral effect, we assayed the attachment, replication, and translation steps of the CVB3 life cycle. NO does not affect the attachment of CVB3 to HeLa cells. However, NO inhibits CVB3 RNA synthesis, as shown by a [3H]uridine incorporation assay, reverse transcription-PCR, and Northern analysis. In addition, NO inhibits CVB3 protein synthesis, as shown by [35S]methionine protein labeling and Western blot analysis of infected cells. Thus, NO inhibits CVB3 replication in part by inhibiting viral RNA synthesis by an unknown mechanism.

[The femoral vein route: an exceptional alternative for the implantation of permanent pacemakers]

A case of thrombosis in the superior vena cava after two permanent pacemaker implantations is described. Ten years ago the patient had a permanent pacemaker implanted because of disturbances in his cardiac rhythm. Five months later he was readmitted with pacemaker malfunction due to failure of the electrode and a new lead was introduced. In 1989 the generator presented "end of life" and the depleted battery was changed. In February, 1993 he presented a new pacemaker malfunction and thrombosis in the superior vena cava. We suggest that in similar cases the iliac vein approach should be performed and short-term anticoagulant therapy should be considered.

A map of rye chromosome 4R with cytological and isozyme markers

The progeny of two crosses between a structural heterozygote for a reciprocal translocation (4RL/5RL) and a homozygote for the standard chromosome arrangement and of four crosses between standard chromosome homozygotes were analysed in rye (Secale cereale L. cv 'Ailés') for the electrophoretic patterns of five different leaf and endosperm isozymes (LAP, PGM, NDH, ADH and EPER). The presence or absence of the quadrivalents at metaphase I (MI) was also tested. Loci Adh-1, Pgm-1 and Ndh-1 were located on chromosome arm 4RS, and locus Eper-1 on chromosome arm 4RL. Locus Lap-2 was located on the 4RS chromosome arm. The estimated distances among the different linked loci support the following gene order: Eper1¨ (breakpoint-centromere)¨Lap-2¨ ¨Adh-1 ¨Pgm-1¨Ndh-1. These results provide evidence for the chromosomal location of Lap-2 locus on chromosome arm 4RS in cv 'Ailés'. A high negative interference was detected between the zones delimited by centromere and Lap-2, and Lap-2 and Pgm-1 in plants with the 4RL/5RL translocation.

Rapid identification of Triticeae genotypes from single seeds using the polymerase chain reaction

An easy and quick protocol has been developed for DNA analysis via PCR. Single cereal endosperm or small leaf pieces can be separately processed in several PCR reactions. The resultant PCR patterns are equivalent to those obtained with standard DNA extraction protocols using either specific or random primers. Intra- and inter-specific variability can be detected. This method allows the analysis of a large number of individuals in early stages prior to the plant sowing.

[A prospective and comparative study of 262 laparoscopic cholecystectomies]

A prospective, comparative study is made of 262 patients (195 males, 67 females) subjected to laparoscopic cholecystectomy. Two groups were considered: simple cholelithiasis (SC) (187 cases), and complicated cholelithiasis (CC) (75 cases: 63 acute cholecystitis, 8 hydrocholecystitis, 4 pancreatitis). Mean age was 51 among the SC cases, and 57 in the CC patients. Mean operating time was 67 and 96 minutes for the SC and groups, respectively. Preoperative complications were more frequent in the CC group (51.4%) than in the SC patients (24%)--immediate laparotomies being performed in 2 and 25% of the SC and CC patients, respectively. Mortality was zero, with similar morbidity in both groups. Mean hospitalization time was 4.9 and 3.4 days for the CC and SC groups, respectively.

NADH dehydrogenase: a new molecular marker for homoeology group 4 in Triticeae. A map of the 4RS chromosome arm in rye

Structural gene loci encoding the monomeric isozymes nicotin adenin dinucleotide dehydrogenase (NADH dehydrogenase or NDH) have been located on the 4AL, 4Bα, and 4DS chromosome arms of Triticum aestivum cv "Chinese Spring", on the 4RS chromosome arm of Secale cereale cultivars "Imperial", "King II", "Dakold," and "Ailes," on the 4S(1) S/7S(1) chromosome of Aegilops longissima, the 4E of Elytrigia elongata, and the CSU-A of Aegilops umbellulata. All the results support the homoeologous relationships among these chromosomes in the five species studied. In addition, a map of the 4RS chromosome arm in cv "Ailes" has been realized, linking loci Pgm-1 (located on the 4RS chromosome arm) and Ndh-1 (17.91 cM), with an estimated distance between both loci and the centromere of 20.00 cM and 32.12 cM, respectively.

Biochemical evidence of a translocation between 6 RL/7 RL chromosome arms in rye (Secale cereale L.). A genetic map of 6R chromosome

The segregation of different isozymic loci was investigated in backcrosses and F2s in rye. The leucin aminopeptidase-1 (Lap-1), Aconitase-1 (Aco-1), Esterase-6 (Est-6), Esterase-8 (Est-8), and Endopeptidase-1 (Ep-1) loci were linked. The Aco-1, Est-6, and Est-8 loci have been previously located on the 6RL chromosome arm. The Lap-1 locus has been located on the 6RS chromosome arm. The results favor the gene order: Lap-1... (centromere)... Aco-1... Est-8... Est-6... Ep-1. The isoelectric focusing separations of aqueous extracts from mature embryo tissue of wheat-rye addition and substitution lines involving the chromosomes of cereal rye Secale cereale L. confirmed the gene location of locus Ep-1 on the 6RL chromosome arm. Screening of wheat-rye addition lines involving the chromosomes of Secale montanum revealed that Ep-1 locus is not located on chromosome 6R of S. montanum. These results are the first biochemical evidence of the translocation between chromosome arms 6RL/7RL in the evolution of S. cereale from S. montanum.

A map of rye chromosome 2R using isozyme and morphological markers

The segregation of isozymic loci for leaf peroxidases (L2Per) has been investigated in backcrosses and F2 offspring of rye lines having purple seeds (Ps) and monstrosum ears (mo). The Ps, L2Per-3b, mo, and L2Per-2 loci were linked. The Ps and mo loci have been previously located on the 2R chromosome, and the L2Per-3b and L2Per-2 loci have been located on the 2RS chromosome arm. The results favor the gene order Ps ... L2Per-3b ... mo ... L2Per-2 or Ps ... mo... L2Per-3b ... L2Per-2. The position of the loci relative to the centromere is still not known, but the obtained results suggest that the mo locus could be located on the 2RS chromosome arm. On the basis of previously reported linkage groups, the most probable arrangement of the loci located on chromosome 2R is: dw2 ... Ps ... (L2Per-3a ... L2Per-3b ... mo) ... L2Per-2. It has not been possible to know the position of L2Per-4 loci (also located on 2RS chromosome arm) relative to L2Per-3a and L2Per-3b loci.

Chromosomal location of adenylate kinase isozymes in Triticeae species

One system of monomeric adenylate kinase isozymes, designated ADK, was observed in Triticum aestivum and in five diploid Triticeae species. The gene loci Adk-a, Adk-b and Adk-d were located on 7AL, 7BL and 7DL Triticum aestivum cv "Chinese Spring" chromosomal arms, respectively. Adk gene loci were also located on the 7RL chromosomal arm of Secale cereale cv "Ailés", the 7H chromosome of Hordeum vulgare cv "Betzes", 7X of Agropyron intermedium, 7E of Elytrigia elongata and CSU-E of Aegilops umbellulata. The results suport the notion of the conservation of gene synteny groups within Triticeae species.

[Hernial strangulation of Meckel's diverticulum: Littre's hernia. Apropos of 4 cases]

Hernial strangulation of Meckel's diverticulum (Littre's hernia) is a rare anatomoclinical form. It represents 10% of all complications of Meckel's diverticulum (8.8% of our cases), and complications like hemorrhage, perforation and diverticulitis are fairly frequent. Four cases of Littre's hernia are presented: two males and two females, with an average age of 67 years (range 50-83 years), representing 0.08% of all the inguinal-crural hernias operated in the department. The clinical manifestations were those of intestinal obstruction because a mixed type Littre's hernia was involved, with compromise of the diverticulum and its intestinal loop. Preoperative diagnosis is unlikely in strangulation without disturbances in the intestinal transit and, in fact, is even less likely if it is accompanied by obstruction. The diagnosis is thus almost always intraoperative. The correct treatment is surgery after restoring the patient's hemodynamic equilibrium. Simple and/or loop diverticulectomy via herniotomy, herniolaparotomy or laparotomy are debated. We think that this disorder can generally be resolved using the inguinal approach, as in any strangled hernia, with the technical option of using a larger, more comfortable and safer approach in cases of important obesity and/or deterioration of the loop (necrosis, perforation). In elderly patients with uncomplicated Littre's hernia and Meckel's diverticulum, abstention from diverticular exeresis may be justifiable. Of the four patients, the first two died from cardiogenic shock and pulmonary embolism, respectively; the last two evolved well (except for a wound abscess).

[Chondrosarcoma of the sinuses: an infrequent tumor]

The case of 69 year old male patient who developed sinusal mesenchymal chondrosarcoma is presented. At the time of diagnosis the tumor had spread into the intracranial cavity, which explains why no surgical treatment was carried out. A combined palliative treatment of chemotherapy and radiotherapy was used which did not improve the course of the tumor. The rare location of this form of tumor is discussed. Also commented on are the therapeutic--both surgical and other modalities (chemotherapy and radiotherapy)--difficulties encountered with this condition, given the little experience accumulated with it and its habitual resistance to the therapeutical regimens employed.