Talc pleurodesis: Evidence of systemic Inflammatory response to small size talc particles

The mechanisms of the systemic response associated with talc-induced pleurodesis are poorly understood. The aim of this study was to assess the acute inflammatory response and migration of talc of small. size particles injected in the pleural space. Rabbits were injected intrapleurally with talc solution containing small. or mixed particles and blood and pleural fluid samples were collected after 6, 24 or 48 h and assayed for leukocytes, neutrophils, lactate dehydrogenase, IL-8, VEGF, and TGF-beta. The lungs, spleen, liver and kidneys were assessed to study deposit of talc particles. Both types of talc produced an acute serum inflammatory response, more pronounced in the small particles group. Pleural fluid IL-8 and VEGF levels were higher in the small particle talc group. Correlation between pleural VEFG and TGF-beta levels was observed for both groups. Although talc particles were demonstrated in the organs of both groups, they were more pronounced in the small talc group. In conclusion, intrapleural injection of talc of small size particles produced a more pronounced acute systemic response and a greater deposition in organs than talc of mixed particles. (C) 2008 Elsevier Ltd. All rights reserved.

Targeted Mutagenesis in Pathogenic Leptospira Species: Disruption of the LigB Gene Does Not Affect Virulence in Animal Models of Leptospirosis

The pathogenic mechanisms of Leptospira interrogans, the causal agent of leptospirosis, remain largely unknown. This is mainly due to the lack of tools for genetically manipulating pathogenic Leptospira species. Thus, homologous recombination between introduced DNA and the corresponding chromosomal locus has never been demonstrated for this pathogen. Leptospiral immunoglobulin-like repeat (Lig) proteins were previously identified as putative Leptospira virulence factors. In this study, a ligB mutant was constructed by allelic exchange in L. interrogans; in this mutant a spectinomycin resistance (Spc(r)) gene replaced a portion of the ligB coding sequence. Gene disruption was confirmed by PCR, immunoblot analysis, and immunofluorescence studies. The ligB mutant did not show decrease virulence compared to the wild-type strain in the hamster model of leptospirosis. In addition, inoculation of rats with the ligB mutant induced persistent colonization of the kidneys. Finally, LigB was not required to mediate bacterial adherence to cultured cells. Taken together, our data provide the first evidence of site-directed homologous recombination in pathogenic Leptospira species. Furthermore, our data suggest that LigB does not play a major role in dissemination of the pathogen in the host and in the development of acute disease manifestations or persistent renal colonization.

Urogenital tuberculosis in a patient with AIDS: an unusual presentation

Background A 38-year-old man with AIDS presented to hospital with a 3-month history of fevers, bilateral lumbar pain, dysuria and increased urinary frequency. Six years earlier he had received 6 months` treatment for pulmonary tuberculosis. At presentation, he was on antiretroviral therapy with a combination of efavirenz, stavudine and lamivudine. Investigations Physical examination, evaluation of HIV viral load, CD4 count, measurement of serum hemoglobin concentration, white blood cell count, urinalysis, urine culture for usual pathogens, direct smear and urine culture for Mycobacterium tuberculosis, chest radiography, abdominal CT, measurement of serum creatinine concentration and estimated creatinine clearance. Diagnosis Urogenital tuberculosis. Management The patient`s symptoms and radiological abnormalities persisted despite antibiotic therapy for presumed bacterial infection. After urine culture had confirmed M. tuberculosis infection, he was administered pharmacological treatment comprising isoniazid, rifampin, pyrazinamide and ethambutol for 2 months, with isoniazid and rifampin given for a further 7 months. His symptoms improved within a few days of initiating treatment. Six months after treatment started, CT revealed a nonfunctioning right kidney and a functional left kidney with areas of scarring. The patient refused right nephrectomy, and completed his pharmacological treatment. No evidence of disease recurrence was observed during 2 years of follow-up.

Non-Human Leukocyte Antigen Antibodies Reactive with Endothelial Cells Could Be Involved in Early Loss of Renal Allografts

Preformed donor-specific human leukocyte antigen (HLA) antibodies have been associated with allograft dysfunction and failure. However, recipients of HLA-identical kidneys can develop acute humoral rejection, implicating putative pathogenic antibodies that are directed against non-HLA antigens. We investigated the presence of endothelial cell reactive antibodies in 11 patients who experienced early loss of their transplanted kidneys owing to humoral rejection and 1 loss from renal venal thrombosis. We examined the potential efficacy of intravenous immunoglobulin to block the binding of these antibodies, as previously suggested for anti-HLA antibodies.

Programmed hypertension in rats treated with a NF-kappa B inhibitor during nephrogenesis: renal mechanisms

Suppression of the renin-angiotensin system (RAS) during murine lactation causes progressive renal injury, indicating a physiological action of angiotensin II on nephrogenesis. The nuclear factor NF-kappa B system is one of the main intracellular mediators of angiotensin II. We investigated whether inhibition of this system with pyrrolidine dithiocarbamate (PDTC) during rat nephrogenesis would lead to similar hypertension and renal injury as observed with RAS suppressors. Immediately after delivery, 32 Munich-Wistar dams, each nursing 6 male pups, were divided into 2 groups: C, untreated, and PDTC, receiving PDTC, 280 mg kg(-1) day(-1) orally, during 21 days. After weaning, the offspring were followed until 10 months of age without treatment. Adult rats that received neonatal PDTC exhibited stable hypertension and myocardial injury, without albuminuria. To gain additional insight into this process, the renal expression of RAS components and sodium transporters were determined by quantitative real-time PCR (qRT-PCR) at 3 and 10 months of life. Renal renin and angiotensinogen were upregulated at 3 and downregulated at 10 months of age, suggesting a role for early local RAS activation. Likewise, there was early upregulation of the proximal sodium/glucose and sodium/bicarbonate transporters, which abated later in life, suggesting that additional factors sustained hypertension in the long run. The conclusions drawn from the findings were as follows: (1) an intact NF-jB system during nephrogenesis may be essential to normal renal and cardiovascular function in adult life; (2) neonatal PDTC represents a new model of hypertension, lacking overt structural injury or functional impairment of the kidneys; and (3) hypertension in this model seems associated with early temporary activation of renal RAS and sodium transporters. Hypertension Research (2011) 34, 693-700; doi: 10.1038/hr. 2011.4; published online 17 February 2011

Assessment of the Expression of IR beta, IRS-1, IRS-2 and IGF-IR beta in a Rat Model of Intrauterine Growth Restriction

Objective: To investigate glomerular development and expression of insulin and insulin-like growth factor receptors in an experimental model of intrauterine growth restriction (IUGR). Material and Methods: We studied three groups of Sprague-Dawley fetuses: IUGR - restricted by ligation of the right uterine artery; C-IUGR - left horn controls, and EC - external controls (non-manipulated). Body and organs were weighed, and glomerular number and volume were analyzed. Expression of IR beta, IRS-1, IRS-2 and IGF-IR beta was analyzed in liver, intestine and kidneys by immunoblotting. Results: Organ/body weight ratios were similar. In IUGR, glomerular number and volume were increased compared to C-IUGR and EC (p < 0.001). In the IUGR liver, increases were found in IGF-IR beta compared to C-IUGR and EC; IR beta compared to EC, and IRS-2 compared to C-IUGR. However, decreases in IR beta were noted in IUGR compared to C-IUGR; IRS-1 compared to C-IUGR and EC, and IRS-2 compared to EC. In IUGR intestine, increases were detected in IR beta, IRS-1 and IGF-IR beta compared to C-IUGR and EC. In IUGR kidneys, increases were observed in IR beta and IGF-IR beta compared to C-IUGR and EC, and IRS-1 compared to EC. Decreased IRS-2 in the intestine and kidney were noticed in IUGR compared to C-IUGR and EC. Conclusion: IUGR fetuses had less glomeruli and alterations in insulin receptors, which may be associated with an increased risk of disease occurrence in adulthood. Copyright (C) 2010 S. Karger AG, Basel

Liver HLA-G expression is associated with multiple clinical and histopathological forms of chronic hepatitis B virus infection

As the mechanisms leading to the persistence of hepatitis B virus (HBV) infection are poorly understood and as the histocompatibility leucocyte antigen (HLA)-G is well described as a tolerogenic molecule, we evaluated HLA-G expression in 74 specimens of HBV liver biopsies and in 10 specimens obtained from previously healthy cadaver liver donors. HBV specimens were reviewed and classified by the METAVIR score, and HLA-G expression was assessed by immunohistochemistry. No HLA-G expression was observed in control hepatocytes. In contrast, 57 (77%) of 74 HBV specimens showed soluble and membrane-bound HLA-G expression in hepatocytes, biliary epithelial cells or both. No associations between the intensity of HLA-G expression and patient age or gender, HBeAg status, severity of liver fibrosis, and grade of histological findings were observed. Although significance was not reached (P = 0.180), patients exhibiting HLA-G expression presented a higher median HBV DNA viral load (105 copies/mL) than those who did not express HLA-G (103.7 copies/mL). These results indicate that HLA-G is expressed in most cases of chronic HBV infection in all stages and may play a role in the persistency of HBV infection.

Renal redox-sensitive signaling, but not blood pressure, is attenuated by Nox1 knockout in angiotensin II-dependent chronic hypertension

We demonstrated previously that, in mice with chronic angiotensin II-dependent hypertension, gp91phoxcontaining NADPH oxidase is not involved in the development of high blood pressure, despite being important in redox signaling. Here we sought to determine whether a gp91phox homologue, Nox1, may be important in blood pressure elevation and activation of redox-sensitive pathways in a model in which the renin-angiotensin system is chronically upregulated. Nox1-deficient mice and transgenic mice expressing human renin (TTRhRen) were crossed, and 4 genotypes were generated: control, TTRhRen, Nox1-deficient, and TTRhRen Nox1-deficient. Blood pressure and oxidative stress (systemic and renal) were increased in TTRhRen mice (P < 0.05). This was associated with increased NADPH oxidase activation. Nox1 deficiency had no effect on the development of hypertension in TTRhRen mice. Phosphorylation of c-Src, mitogen-activated protein kinases, and focal adhesion kinase was significantly increased 2-to 3-fold in kidneys from TTRhRen mice. Activation of c-Src, p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and focal adhesion kinase but not of extracellular signal regulated kinase 1/2 or extracellular signal regulated kinase 5, was reduced in TTRhRen/Nox1-deficient mice (P < 0.05). Expression of procollagen III was increased in TTRhRen and TTRhRen/Nox1-deficient mice versus control mice, whereas vascular cell adhesion molecule-1 was only increased in TTRhRen mice. Our findings demonstrate that, in Nox1-deficient TTRhRen mice, blood pressure is elevated despite reduced NADPH oxidase activation, decreased oxidative stress, and attenuated redox signaling. Our results suggest that Nox1-containing NADPH oxidase plays a key role in the modulation of systemic and renal oxidative stress and redox-dependent signaling but not in the elevation of blood pressure in a model of chronic angiotensin II-dependent hypertension.

Essential Role of CCR2 in Neutrophil Tissue Infiltration and Multiple Organ Dysfunction in Sepsis

Rationale Sepsis is defined as a systemic inflammatory response to infection, which in its severe form is associated with multiple organ dysfunction syndrome (MODS). The precise mechanisms by Which MODS develops remain unclear. Neutrophils have a pivotal role in the defense against infections; however, overwhelming activation of neutrophils is known to elicit tissue damage. Objectives: We investigated the role of the chemokine receptor CCR2 in driving neutrophil infiltration and eliciting tissue damage in remote organs during sepsis. Methods: Sepsis was induced in wild-type mice treated with CCR2 antagonist (RS504393) or CCR2(-/-) mice by cecal ligation and puncture (CLP) model. Neutrophil infiltration into the organs was measured by myeloperoxidase activity and fluorescence-activated cell sorter. CCR2 expression and chemotaxis were determined in neutrophils stimulated with Toll-like receptor agonists or isolated from septic mice and patients. Measurements and Main Results: CCR2 expression and responsiveness to its ligands was induced in circulating neutrophils during CLP-induced sepsis by a mechanism dependent on Toll-like receptor/nuclear factor-kappa B pathway. Genetic or pharmacologic inhibition of CCR2 protected mice from CLP-induced mortality. This protection was associated with lower infiltration of neutrophils into the lungs, heart, and kidneys and reduced serum biochemical indicators of organ injury and dysfunction. Importantly, neutrophils from septic patients express high levels of CCR2, and the severity of patient illness correlated positively with increasing neutrophil chemotaxis to CCR2 ligands. Conclusions: Collectively, these data identify CCR2 as a key receptor that drives the inappropriate infiltration of neutrophils into remote organs during sepsis. Therefore, CCR2 blockade is a novel potential therapeutic target for treatment of sepsis-induced MODS.

Alpha-tocopherol prevents intrauterine undernutrition-induced oligonephronia in rats

The role of alpha-tocopherol during nephrogenesis was investigated in rats subjected to maternal undernutrition, which reduces the number of nephrons. alpha-tocopherol (350 mg/kg, p.o.) was administered daily to well-nourished or malnourished Wistar dams during pregnancy, or to prenatal undernourished rats during lactation. The kidneys of 1- and 25-day-old offspring were removed to evaluate expression of angiotensin II (Ang II) and to correlate this with expression of proliferating cell nuclear antigen, alpha-smooth muscle actin, fibronectin and vimentin in the glomeruli and tubulointerstitial space. One-day-old prenatally undernourished rats had reduced expression of Ang II and of kidney development markers, and presented with an enlarged nephrogenic zone. Maternal administration of alpha-tocopherol restored the features of normal kidney development in undernourished rats. Twenty-five-day-old prenatally undernourished progeny had fewer glomeruli than the control group. Conversely, animals from mothers that received alpha-tocopherol during lactation presented with the same number of glomeruli and the same glomerular morphometrical profile as the control group. Analyzing the levels of thiobarbituric acid reactive substances in the liver in conjunction with kidney development markers, it is plausible that alpha-tocopherol had antioxidant and non-antioxidant actions. This study provides evidence that alpha-tocopherol treatment restored Ang II expression, and subsequently restored renal structural development.

Inhibition of hydrogen sulphide formation reduces cisplatin-induced renal damage

Background. Cisplatin (CP)-induced renal damage is associated with inflammation. Hydrogen sulphide (H(2)S) is involved in models of inflammation. This study evaluates the effect of DL-propargylglycine (PAG), an inhibitor of endogenous H(2)S formation, on the renal damage induced by CP. Methods. The rats were injected with CP (5 mg/kg, i.p.) or PAG(5 mg/kg twice a day, i.p.) for 4 days, starting 1 h before CP injection. Control rats were injected with 0.15 M NaCl or PAG only. Blood and urine samples were collected 5 days after saline or CP injections for renal function evaluation. The kidneys were removed for tumour necrosis factor (TNF)-alpha quantification, histological, immunohistochemical and Western blot analysis. The cystathionine gamma-lyase (CSE) activity and expression were assessed. The direct toxicity of H(2)S in renal tubular cells was evaluated by the incubation of these cells with NaHS, a donor of H(2)S. Results. CP-treated rats presented increases in plasma creatinine levels and in sodium and potassium fractional excretions associated with tubulointerstitial lesions in the outer medulla. Increased expression of TNF-alpha, macrophages, neutrophils and T lymphocytes, associated with increased H(2)S formation rate and CSE expression, were also observed in the outer medulla from CP-injected rats. All these alterations were reduced by treatment with PAG. A direct toxicity of NaHS for renal tubular epithelial cells was not observed. Conclusions. Treatment with PAG reduces the renal damage induced by CP. This effect seems to be related to the H2S formation and the restriction of the inflammation in the kidneys from PAG+CP-treated rats.

Treatment with a p38 MAPK inhibitor attenuates cisplatin nephrotoxicity starting after the beginning of renal damage

Aims: Cisplatin (CP) promotes increased production of reactive oxygen species, which can activate p38 mitogen activated protein kinases (p38 MAPKs) leading to apoptosis and increased expression of proinflammatory mediators that intensify the cytotoxic effects of CP. We investigated the effect of the treatment with S13203580, a p38 MAPKs inhibitor, on oxidative stress, on the oxidation-associated signal, p38 MAPK and on apoptosis in U-injected rats, starting after the beginning of the renal damage. Main methods: Rats (n = 21) were injected with CP (5 mg/kg, i.p.) and 3 and 4 days after some of them (n = 8) were treated with SB203580 (0.5 mg/kg, i.p.). Controls (n = 6) received saline (i.p.). Two or five days after saline or CP injections, plasma creatinine, urinary volume, sodium and potassium fractional excretions, blood urea nitrogen and urinary lipid peroxidation were measured. The kidneys were removed for histological, apoptosis, immunohistochemical and Western blot studies. Key findings: CP caused abnormalities in kidney functions and structure associated with raised urinary peroxidation levels and higher number of apoptotic cells in the outer medulla. The immunostaining studies showed increased numbers of macrophages/monocytes and p-p38 MAPKs positive cells in the renal outer medulla. The increase of p-p38 MAPKs expression was confirmed by Western blot analysis. All of these alterations were attenuated by treatment with S13203580. Significance: These data suggest that the beneficial effect of SB203580 on CP-induced renal damage might be related, in part, to the blockade of p38 MAPK activation with reduction of the inflammatory process, oxidative stress and apoptotic cell death. (C) 2009 Elsevier Inc. All rights reserved.

Neonatal Handling Reduces Renal Function in Adult Rats

Background/Aims: To evaluate the effects of neonatal handling on hydroelectrolytic balance in adult rats. Methods: The litters were divided into two groups: nonhandled and handled. The procedure consisted of handling the pups for 1 min/day in the first 10 days postnatally. When adults, animals had their body weight verified and were housed in individual metabolic cages. After a 24-hour period, urine samples were collected and the urinary and water intake volumes measured. Blood samples to determine osmolality, aldosterone, corticosterone, angiotensin II, creatinine, urea, sodium and potassium levels were collected. The kidneys were removed for histological assessment. Urinary osmolality, sodium, urea and creatinine were also measured and the creatinine clearance (CC) calculated. Results: No difference between groups was found in the body weight. Handled animals showed a reduction in the total kidney wet weight, water intake, urinary volume, CC, plasma angiotensin II, corticosterone and aldosterone when compared to the nonhandled and an increase in the urinary osmolality and sodium excretion fraction. No differences in serum potassium and no evidence of structural changes were demonstrated by histological analysis. Conclusion: Neonatal handling induced long-lasting effects decreasing renal function without evidence of kidney structural changes. Copyright (c) 2009 S. Karger AG, Basel

MAPK and angiotensin II receptor in kidney of newborn rats from losartan-treated dams

Several lines of evidence suggest that angiotensin II (A-II) participates in the postnatal development of the kidney in rats. Many effects of A-II are mediated by mitogen-activated protein kinase (MAPK) pathways. This study investigated the influence that treatment with losartan during lactation has on MAPKs and on A-II receptor types 1 (AT(1)) and 2 (AT(2)) expression in the renal cortices of the offspring of dams exposed to losartan during lactation. In addition, we evaluated the relationship between such expression and changes in renal function and structure. Rat pups from dams receiving 2% sucrose or losartan diluted in 2% sucrose (40 mg/dl) during lactation were killed 30 days after birth, and the kidneys were removed for histological, immunohistochemical, and Western blot analysis. AT(1) and AT(2) receptors and p-p38, c-Jun N-terminal kinases (p-JNK) and extracellular signal-regulated protein kinases (p-ERK) expression were evaluated using Western blot analysis. The study-group rats presented an increase in AT(2) receptor and MAPK expression. In addition, these rats also presented lower glomerular filtration rate (GFR), greater albuminuria, and changes in renal structure. In conclusion, newborn rats from dams exposed to losartan during lactation presented changes in renal structure and function, which were associated with AT(2) receptor and MAPK expression in the kidneys.

Renal structure and function evaluation of rats from dams that received increased sodium intake during pregnancy and lactation submitted or not to 5/6 nephrectomy

Adult rats submitted to perinatal salt overload presented renin-angiotensin system (RAS) functional disturbances. The RAS contributes to the renal development and renal damage in a 5/6 nephrectomy model. The aim of the present study was to analyze the renal structure and function of offspring from dams that received a high-salt intake during pregnancy and lactation. We also evaluated the influence of the prenatal high-salt intake on the evolution of 5/6 nephrectomy in adult rats. A total of 111 sixty-day-old rat pups from dams that received saline or water during pregnancy and lactation were submitted to 5/6 nephrectomy (nephrectomized) or to a sham operation (sham). The animals were killed 120 days after surgery, and the kidneys were removed for immunohistochemical and histological analysis. Systolic blood pressure (SBP), albuminuria, and glomerular filtration rate (GFR) were evaluated. Increased SBP, albuminuria, and decreased GFR were observed in the rats from dams submitted to high-sodium intake before surgery. However, there was no difference in these parameters between the groups after the 5/6 nephrectomy. The scores for tubulointerstitial lesions and glomerulosclerosis were higher in the rats from the sham saline group compared to the same age control rats, but there was no difference in the histological findings between the groups of nephrectomized rats. In conclusion, our data showed that the high-salt intake during pregnancy and lactation in rats leads to structural changes in the kidney of adult offspring. However, the progression of the renal lesions after 5/6 nephrectomy was similar in both groups.