Renin-angiotensin-aldosterone system blockers effect in chronic kidney disease progression in hypertensive elderly patients without proteinuria: PROERCAN trial

INTRODUCTION

Evidence about nefroprotective effect with RAAS blockers in elderly patients with chronic kidney disease (CKD) without proteinuria is lacking. The primary outcome of our study is to evaluate the impact of RAAS blockers in CKD progression in elderly patients without proteinuria.

MATERIALS AND METHODS

Multicenter open-label, randomized controlled clinical trial including patients over 65 year-old with hypertension and CKD stages 3-4 without proteinuria. Patients were randomized in a 1:1 ratio to either receive RAAS blockers or other antihypertensive drugs and were followed up for three years. Primary outcome is estimated glomerular filtration rate (eGFR) decline at 3 years. Secondary outcome measures include BP control, renal and cardiovascular events and mortality.

RESULTS

88 patients were included with a mean age of 77.9±6.1 years and a follow up period of 3 years: 40 were randomized to RAAS group and 48 to standard treatment. Ethiology of CKD was: 53 vascular, 16 interstitial and 19 of unknown ethiology. In the RAAS group eGFR slope during follow up was -4.3±1.1ml/min, whereas in the standard treatment group an increase on eGFR was observed after 3 years (+4.6±0.4ml/min), p=0.024. We found no differences in blood pressure control, number of antihypertensive drugs, albuminuria, potassium serum levels, incidence of cardiovascular events nor mortality during the follow up period.

CONCLUSIONS

In elderly patients without diabetes nor cardiopathy and with non proteinuric CKD the use of RAAS blockers does not show a reduction in CKD progression. The PROERCAN (PROgresión de Enfermedad Renal Crónica en ANcianos) trial (trial registration: NCT03195023).

The effect of renin-angiotensin-aldosterone system blockers on the progression of chronic kidney disease in hypertensive elderly patients without proteinuria: PROERCAN study. Rationale and design

INTRODUCTION

Blood pressure (BP) control is fundamental to the care of patients with chronic kidney disease (CKD), and is relevant at all stages of CKD. Renin-angiotensin-aldosterone system (RAAS) blockers have shown to be effective, not only in BP control but also in reducing proteinuria and slowing CKD progression. However, there is a lack of evidence for recommending RAAS blockers in elderly patients with CKD without proteinuria. The primary outcome of the present study is to evaluate the impact of RAAS blockers on CKD progression in elderly patients without proteinuria.

MATERIALS AND METHODS

The PROERCAN trial (trial registration, NCT03195023) is a multicentre open-label, randomized controlled clinical trial with 110 participants over 65 years-old with hypertension and CKD stages 3-4 without proteinuria. Patients will be randomized in a 1:1 ratio to either receive RAAS blockers or other antihypertensive drugs, and will be followed up for three years. Primary outcome is the estimated glomerular filtration rate (eGFR) decline at 3 years. Secondary outcomes include BP control, renal and cardiovascular events, and mortality.

RESULTS AND CONCLUSIONS

The design of this trial is presented here. The results will show if antihypertensive treatment with RAAS blockers has an impact on CKD progression in elderly patients without proteinuria. Any differences in BP control, cardiovascular events, and mortality with each antihypertensive treatment will be also clarified.

Accelerated bone formation by biphasic calcium phosphate with a novel sub-micron surface topography

Osteoinductive calcium phosphate (CaP) bone grafts have equivalent performance to autografts in repairing critical-size bone defects. The osteoinductive potential of CaP is linked to the size of the surface topographical features. In the present study, two novel biphasic calcium phosphate (BCP) bone grafts were synthesised with either sub-micron- (BCP<µm) or micron-scale (BCPµm) needle-shaped surface topography and compared to dimensionally similar tricalcium phosphate (TCP) with grain-shaped surface structures (TCP<µm and TCPµm). To clarify the possible function of the surface morphology (needle-like vs. grain-like) in initiating bone formation, the four CaP test materials were physicochemically characterised and implanted for 12 weeks in the dorsal muscle of beagles. The sub-micron needle-shaped topography of BCP<µm triggered earlier bone formation (3-6 weeks) as compared to the grain-shaped surface topography of TCP<µm, which formed bone at 6-9 weeks. After 12 weeks, the amount of induced bone formation in both materials was equivalent, based on histomorphometry. The micron-sized needle-shaped surface topography of BCPµm led to limited formation of new bone tissue, whereas its counterpart, TCPµm with grain-shaped surface topography, failed to trigger de novo bone formation. The relative strength of the parameters affecting CaP-driven bone induction was as follows: surface feature size > surface feature morphology > substrate chemistry. BCP materials with needle-shaped sub-micron surface topography gave rise to accelerated bone formation and slower rate of resorption than a comparable TCP. These characteristics may be translated to improve bone healing in orthotopic defects.

Whole genome sequence and phenotypic characterization of a Cbm+ serotype e strain of Streptococcus mutans

We report the whole genome sequence of the serotype e Cbm⁺ strain LAR01 of Streptococcus mutans, a dental pathogen frequently associated with extra-oral infections. The LAR01 genome is a single circular chromosome of 2.1 Mb with a GC content of 36.96%. The genome contains 15 phosphotransferase system gene clusters, seven cell wall-anchored (LPxTG) proteins, all genes required for the development of natural competence and genes coding for mutacins VI and K8. Interestingly, the cbm gene is genetically linked to a putative type VII secretion system that has been found in Mycobacteria and few other Gram-positive bacteria. When compared with the UA159 type strain, phenotypic characterization of LAR01 revealed increased biofilm formation in the presence of either glucose or sucrose but similar abilities to withstand acid and oxidative stresses. LAR01 was unable to inhibit the growth of Strpetococcus gordonii, which is consistent with the genomic data that indicate absence of mutacins that can kill mitis streptococci. On the other hand, LAR01 effectively inhibited growth of other S. mutans strains, suggesting that it may be specialized to outcompete strains from its own species. In vitro and in vivo studies using mutational and heterologous expression approaches revealed that Cbm is a virulence factor of S. mutans by mediating binding to extracellular matrix proteins and intracellular invasion. Collectively, the whole genome sequence analysis and phenotypic characterization of LAR01 provides new insights on the virulence properties of S. mutans and grants further opportunities to understand the genomic fluidity of this important human pathogen.

How uncertainty bounds the shape index of simple cells

We propose a theoretical motivation to quantify actual physiological features, such as the shape index distributions measured by Jones and Palmer in cats and by Ringach in macaque monkeys. We will adopt the uncertainty principle associated to the task of detection of position and orientation as the main tool to provide quantitative bounds on the family of simple cells concretely implemented in primary visual cortex.Mathematics Subject Classification (2000)2010: 62P10, 43A32, 81R15.

Clinical manifestations, treatment, and outcomes of children and adolescents with eosinophilic esophagitis

OBJECTIVE

This study aimed to describe the clinical, endoscopic, and histologic characteristics, as well as the response to conventional treatment of pediatric patients with the classical form of eosinophilic esophagitis (EoE).

METHODS

Study of clinical, laboratory, endoscopic, and histologic data and response to conventional treatment of 43 previously followed pediatric patients with the classical form of EoE.

RESULTS

A total of 43 patients diagnosed with EoE were included in the study, of which 37 were males (86%), with a mean age of 8.4 years. The most common symptoms were: nausea, vomiting, and abdominal pain (100%) in children younger than 7 years, and loss of appetite (60%), heartburn (52%), and food impaction (48%) in children older than 7 years and adolescents. Regarding the endoscopic findings, 12 (28%) patients had whitish plaques on the esophageal lining, 8 (18.5%) had longitudinal grooves, 2 (4.5%) had concentric rings, 3 (7%) had longitudinal grooves and whitish plaques, and the remaining 18 (42%) had esophageal mucosa with normal appearance. Despite the initial favorable response, 76.7% of patients required more than one course of corticosteroid therapy (systemic or aerosol) and diet (exclusion or elimination of food or elementary allergens). Persistence of eosinophil infiltration was found in some patients despite favorable clinical response.

CONCLUSIONS

The classic form of EoE typically shows different symptoms according age range. A significant number of patients required more than one treatment cycle to show clinical remission. Endoscopic and histologic improvement was observed; however, eosinophilic infiltration persisted in some patients.

A benchmark study on 883 nasopharyngeal cancer patients treated in two Italian centres from 1977 to 2000. Part I: Evolving technical choices and survival

PURPOSE

The authors sought to define treatment results according to the different accrual periods and clinical-therapeutic features in a large series of nasopharyngeal cancer (NPC) patients treated in two Italian centres over more than two decades.

MATERIALS AND METHODS

A total of 883 patients consecutively treated with radiotherapy between 1977 and 2000 at the Florence (FLO) and Brescia (IRA) Radiation Oncology centres were studied. Five-year overall (OS) and disease-specific (DSS) actuarial survival rates in the different pathological, clinical and therapeutic subgroups were calculated, along with the actuarial local-regional control (LRC) probability.

RESULTS

At univariate analysis, survival and local control rates were significantly better in the more recent accrual periods and in the more favourable disease presentations; treatment-related parameters mainly affect LRC. At multivariate analysis, patient- and disease-related factors had a more evident prognostic effect than did therapeutic factors, although dose to the nasopharynx and treatment technique had a marginally significant impact on DSS and OS.

CONCLUSIONS

Results of this benchmark study may be useful for understanding the development of new radio-therapy techniques for NPC, such as three-dimensional conformal radiotherapy (3D-CRT) and particularly intensity-modulated radiotherapy (IMRT).

Heterotopic bone formation by nano-apatite containing poly(D,L-lactide) composites

To render polymeric materials osteoinductive, nano-sized calcium phosphate apatite particles (CaP) were introduced into a low molecular weight poly(D,L-lactide). Homogenous composites were made with 10%, 20% and 40% by weight of apatite content while pure polylactide was used as control. Thereafter porous samples (pore size 300-400 microm, 60% porosity) were fabricated and sterilized. In vitro studies showed that calcium ions were released from the composites depending on the apatite content, while surface mineral deposition was observed only on the 40% CaP composites in simulated body fluid (SBF) within 14 days. After 12 weeks of intramuscular implantation in dogs, only the 40% CaP composite implant retained its shape and showed ectopic bone formation within the pores. In conclusion, adding a content of 40% apatite into poly(D,L-lactide) could lead to an osteoinductive material. Future studies will focus on understanding this phenomenon of material-directed osteoinduction in order to develop a promising bone graft substitute.

Helicobacter pylori and cagA and vacA gene status in children from Brazil with chronic gastritis

Helicobacter pylori has been shown to be strongly associated with chronic gastritis, gastric and duodenal ulceration, and is a risk factor for gastric carcinoma. Histology, urease, culture, and polymerase chain reaction have been employed as for H. pylori diagnostic methods, pre and post treatment or during follow-up of dyspeptic adult individuals referred for endoscopy. In order to obtain a more-sensitive and specific method for H. pylori detection, we evaluated gastric body and antrum biopsies of 134 consecutive Brazilian consecutive dyspeptic children aged 1-16 years by rapid urease test, histology and polymerase chain reaction using two pairs of oligonucleotides. Our results indicated that polymerase chain reaction with Southern blotting and hybridization with specific chemiluminescent probes increased the number of positive H. pylori patients by 35%. The genotyping of H. pylori strains directly from gastric biopsy using the same nucleic acid methodology revealed that there is no association of chronic gastritis in our infant patients with vacA s1 and the presence of the cagA gene. These data suggest an initial infection of children with normal mucosa and probably others factors than vacA s1 genotype or the presence of the cagA gene are associated with the onset of gastric disease. Altogether, our results reinforce the need for using more sensitive diagnostic methods in order to understand the role of H. pylori in the genesis of gastric disease in children and its progression in adults.

Serum soluble interleukin-2 receptor, interleukin-6, and tumor necrosis factor-alpha levels in children with celiac disease: response to treatment

OBJECTIVES

T-cell mediated immune response to dietary gluten and cytokines release are important for the enteropathy seen in celiac disease. We investigated the serum levels of soluble interleukin-2 receptor, interleukin-6, and tumor necrosis factor-alpha in celiac children before and after gluten exclusion.

METHODS

Cytokine levels were determined using enzyme immunoassay in serum from 12 untreated celiac patients, 16 treated celiac patients on a gluten-free diet for at least two years, and from 26 control children. Eight of 12 untreated patients were also investigated at 6 and 12 months after gluten exclusion. Serum IgA antiendomysium antibodies were also assayed by indirect immunofluorescence.

RESULTS

Soluble interleukin-2 receptor and interleukin-6 levels were significantly increased in untreated celiac patients compared with treated and control children. There was no difference in the tumor necrosis factor-alpha levels between the groups. Soluble interleukin-2 receptor levels were the only ones significantly decreased at 12 months after gluten exclusion. However, soluble interleukin-2 receptor and interleukin-6 levels at 12 months were significantly higher compared with controls. Antiendomysium antibodies had a diagnostic sensitivity of 100% and the titers decreased significantly after 12 months of gluten exclusion. A significant positive correlation was found between antiendomysium antibody titers with both soluble interleukin-2 receptor and interleukin-6 values.

CONCLUSIONS

The serum soluble interleukin-2 receptor and interleukin-6 levels may be used as a noninvasive measure of celiac disease activity and response to treatment.

Involvement of PI 3-kinase, PKA and PKC in PDGF- and TGF-beta-mediated prevention of 2-deoxy-D-ribose-induced apoptosis in the insect cell line, IPLB-LdFB

Activation of phosphatidylinositol (PI) 3-kinase, protein kinase A (PKA) and protein kinase C (PKC) is associated with the survival effect elicited by PDGF-AB and TGF-beta1 against the apoptotic inducer 2-deoxy-D-ribose (dRib) in the fat body cell line, IPLB-LdFB, from the insect Lymantria dispar. dRib induces apoptosis and provokes mitochondrial membrane depolarization (MMD). The antioxidant N -acetyl-L-cysteine annuls only the first effect. These findings suggest that apoptosis and MMD are provoked by two different mechanisms, and that dRib induces apoptosis by oxidative stress.

An anti-Bcl-2 antibody prevents 2-deoxy-D-ribose-induced apoptosis in the IPLB-LdFB insect cell line

Confocal microscopy reveals that the anti-Bcl-2 antibody (pAb) is able to diffuse across the plasma membrane of the fat body cell line IPLB-LdFB from the insect Lymantria dispar, demonstrating the presence of Bcl-2-like molecules in the cytoplasm. Immunoperoxidase procedure confirms the cellular localization. Furthermore, an immunoprecipitation corresponding to a molecular weight of 29 KDa is observed with western blot analysis using the anti-Bcl-2 pAb. Cytofluorimetric experiments show that anti-Bcl-2 pAb counteracts 2-deoxy-D-ribose-induced apoptosis and provokes morphological changes in the insect cell line, i. e. a reduction in cell size, the disappearance of the vacuola and changes in shape. At the same time, the antibody provokes mitochondrial membrane depolarization, and N-acetyl-L-cysteine is unable to reconstitute the physiological conditions. The present findings suggest that Bcl-2-like proteins play a main role in maintaining of the integrity of cellular components, e.g. mitochondria, rather than in controlling programmed cell death.

Nitric oxide induces apoptosis in the fat body cell line IPLB-LdFB from the insect Lymantria dispar

The presence of immunoreactive inducible nitric oxide synthase molecules (ir-iNOS) is demonstrated in the Lymantria dispar IPLB-LdFB cell line. The maximum ir-iNOS inducibility is observed 18 h after incubation with sodium nitroprusside (SNP). The increase in NO provoked by SNP in turn induces apoptosis. However, this phenomenon is observed only after 48 h. The NOS-inhibitors N(omega)-nitro-L-arginine methyl ester (L-NAME) and N-[3-(aminomethyl)-benzyl]acetamide (1400W) were both unable to block the SNP-induced apoptosis at all the concentrations used. Incubation with SNP plus N-acetyl-L-cysteine (NAC) further augmented the percentage of cell death with respect to SNP used alone, and this process is seen earlier, i.e. after 24 h. Moreover, the induction of apoptosis in the presence of NAC is time- and concentration-dependent. The high percentage of cell death with SNP+NAC suggests that NAC forms S-nitrosothiols with NO, resulting in an increase in the bioavailability of NO. In conclusion, these findings show the existence of a close relationship between mammalian and invertebrate cells with regards to SNP and NAC induction and the related NO response.

[Inflammatory bowel diseases]

OBJECTIVE: To present a review about inflammatory bowel diseases in childhood so that pediatricians become familiar with two diseases (ulcerative colitis and Crohn s disease) that are increasing in incidence. METHODS: Articles of specific gastroenterological journals were analyzed. Information was also obtained from the author s extensive professional experience in the area. RESULTS: The two diseases are described. Etiopathogenesis is obscure. Clinical presentation, diagnosis, and treatment are discussed, with details and practical aspects to enable the pediatrician to promptly understand the subject. CONCLUSIONS: The inflammatory bowel disease is a condition of high morbidity, and the pediatrician who assists the case must have a very good technical knowledge about the disease, and must be very comprehensive and emotionally serene, in order to afford the young patient a better quality of life throughout the complicated evolution of this disease.

Apoptosis induced by 2-chloro-adenosine and 2-chloro-2'-deoxy-adenosine in a human astrocytoma cell line: differential mechanisms and possible clinical relevance

We have previously demonstrated that 2-chloro-adenosine (2-CA) can induce apoptosis of rat astroglial cells (Abbracchio et al. [1995] Biochem. Biophys. Res. Commun. 213:908-915). In the present study, we have characterized, for the first time, the effects induced on a human astrocytoma cell line (ADF cells) by both 2-CA and its related analog 2-chloro-2'-deoxy-adenosine (2-CdA, that is employed as anti-cancer agent in chronic lymphoid malignancies). Exposure of these cells to either adenosine analog resulted in time- and concentration-dependent apoptosis. Experiments with pharmacological agents known to interfere with adenosine receptors, its membrane transporter, and intracellular nucleoside kinases showed that: (i) cell death induced by either adenosine analog did not depend on extracellular adenosine receptors, but on a direct intracellular action; however, only in the case of 2-CA, was entry into cells mediated by the specific nitrobenzyl-tioinosine-sensitive transporter; (ii) for both adenosine analogs, induction of apoptosis required the phosphorylation/activation by specific intracellular nucleoside kinases, i.e., adenosine kinase for 2-CA, and deoxycytidine kinase for 2-CdA. In addition, only in the case of 2-CdA, was induction of apoptosis preceded by a block of cells at the G2/M phase of the cell cycle. Finally, at concentrations of either analog that killed about 80-90% of astrocytoma cells, a significantly lower effect on the viability of primary cortical neurons was observed. In conclusion, both adenosine analogs can trigger apoptosis of human astrocytoma cells, albeit with different mechanisms. This effect together with the relative sparing of neuronal cells, may have potential clinical implications for the therapy of tumors of glial origin.

Abnormal phenotype of in vitro dermal fibroblasts from patients with Pseudoxanthoma elasticum (PXE)

Pseudoxanthoma elasticum (PXE) is a genetic connective tissue disease, whose gene and pathogenesis are still unknown. Dermal fibroblasts from patients affected by PXE have been compared in vitro with fibroblasts taken from sex and age-matched normal individuals. Cells were grown and investigated in monolayer, into three-dimensional collagen gels and in suspension. Compared with normal cells, PXE fibroblasts cultured in monolayer entered more rapidly within the S phase and exhibited an increased proliferation index; on the contrary, similarly to normal fibroblasts, PXE cells did not grow in suspension. Furthermore, compared with normal fibroblasts, PXE cells exhibited lower efficiency in retracting collagen type I lattices and lower adhesion properties to collagen type I and to plasma fibronectin. This behavior was associated with higher expression of integrin subunits alpha2, alpha5, alphav, whereas beta1 subunit as well as alpha2beta1 and alpha5beta1 integrin expression was lower than in controls. Compared to controls, PXE fibroblasts had higher CAM protein expression in accordance with their high tendency to form cellular aggregates, when kept in suspension. The demonstration that PXE fibroblasts have altered cell-cell and cell-matrix interactions, associated with modified proliferation capabilities, is consistent with the hypothesis that the gene responsible for PXE might have a broad regulatory role on the cellular machinery.

Activation of the A3 adenosine receptor affects cell cycle progression and cell growth

The A3 adenosine receptor has been implicated in modulation of cell growth. As a first step to the characterization of the underlying mechanisms, we exposed Chinese hamster ovary (CHO) cells transfected with the human A3 receptor (A3R-CHO) to selective A3 receptor ligands. At micromolar concentrations, the A3 agonists N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) and its 2-chloro derivative Cl-IB-MECA reduced cell number, with no effects on either parental CHO cells (not expressing any adenosine receptor), or CHO cells transfected with the human A1 receptor. Cl-IB-MECA also reduced cell number in the human HEK293 cell line transfected with the human A3 receptor cDNA as opposed to the respective untransfected wild-type cells. In A3R-CHO, agonist-induced effects were antagonized by nanomolar concentrations of A3 antagonists, including the triazoloquinazoline derivative MRS 1220, the dihydropyridine derivative MRS 1191, and the triazolonaphthyridine derivative L-249,313. A3 agonist-induced effects were not due to modulation of cell adhesion, nor to necrosis or apoptosis. Growth curves revealed highly impeded growth, and flow-cytometric analysis showed markedly reduced bromodeoxyuridine incorporation into nuclei. The effect on cell cycle was completely antagonized by MRS1191. Hence, activation of the human A3 receptor in A3R-CHO results in markedly impaired cell cycle progression, suggesting an important role for this adenosine receptor subtype in cell cycle regulation and cell growth.

PDGF and TGF-beta partially prevent 2-deoxy-D-ribose-induced apoptosis in the fat body cell line IPLB-LdFB from the insect Lymantria dispar

The IPLB-LdFB cell line from the fat body of the insect Lymantria dispar shows the presence of immunoreactive, platelet-derived growth factor (PDGF)-AB and transforming growth factor (TGF)-beta1 molecules, as well as the corresponding plasma membrane-like receptors, i.e. PDGFR-alpha, PDGFR-beta and TGFR-beta type II. Cytofluorimetric and morphological studies reveal that the reducing sugar 2-deoxy-D-ribose (dRib), an apoptotic agent for human cells, induces apoptosis in a concentration- and time-dependent manner even in IPLB-LdFB cells. PDGF-AB and TGF-beta1 partially counteract the effect of dRib, indicating a survival role of these factors in this apoptotic model of insect cells.

[Treatment of unspecific ulcerative rectocolitis in a child with enemas containing butyrate. Case report]

OBJECTIVE

To report a promising therapy to ulcerative colitis in children.

METHODS

We report a case of ulcerative colitis in 4 years old female, who had this diagnosis since she was 1 year old. The treatment of RCU1 had an unsatisfactory response to conventional therapies (rectal and oral corticosteroids and immunosuppressive agent).

RESULTS

She showed improvement, using enemas containing butyrate, in clinical, endoscopic and histological parameters.

CONCLUSIONS

Although the role of butyrate in the treatment of ulcerative colitis still remains to be determined, we find effective response in this case. Despite evidences that butyrate may be beneficial and safety in treating refractory distal ulcerative colitis, results of controlled trials, specially in children will be necessary to prove the efficacy of this therapy.

[Serum antibodies in celiac disease]

Accurate diagnosis of celiac disease is important because patients are advised to adhere to a strict gluten-free diet for life. This management is critical to avoid disease complications such as malignancies. In this review the new terminology for the disease clinical features (active, silent, latent and potential celiac disease) and the disease association with other conditions are commented. The value and efficacy of the assessment of serum antigliadin antibodies and of antireticulin, antiendomysial and tissue transglutaminase autoantibodies in the diagnosis and follow-up of the celiac disease are particularly evaluated.

Long-term immunologic effects of thymectomy in patients with myasthenia gravis

BACKGROUND

Thymectomy (Tx) is a common therapeutic option to treat myasthenia gravis (MG), but its effects on the immune system are still obscure in humans.

OBJECTIVE

We sought to evaluate long-term immunologic effects of therapeutic Tx in patients with MG.

METHODS

T- and B-cell subsets and T-cell repertoire were analyzed in 35 patients with MG, 16 with previous Tx (at least 8 years before), 6 with recent (<1 year) Tx, and 13 without Tx, as well as in 32 healthy subjects used as normal control subjects. Serum immunoglobulins and a variety of autoantibodies were also measured. A subsequent 3-year clinical follow-up was performed to verify the possible appearance of systemic autoimmune diseases.

RESULTS

The long-term thymectomized (Txd) patients had mild T-cell lymphopenia and an expansion of some Vbeta families among circulating CD4+ and CD8+ T cells. They displayed a normal number of total B and CD5+ B-circulating lymphocytes, but they also displayed a polyclonal increase in serum IgM and IgG associated with the presence of high levels of a variety of organ- and nonorgan-specific autoantibodies, including anti-dsDNA and anticardiolipin, without clinical evidence of autoimmune disease. These serologic abnormalities were not detectable in both non-Txd and recently Txd patients. After 3 years, 2 long-term Txd patients had systemic lupus erythematosus and an undifferentiated connective tissue disease.

CONCLUSIONS

The association between MG and laboratory findings of systemic autoimmune disease may be in part related to Tx rather than to MG. Tx may represent a risk for the development of systemic autoimmune disorders over years in patients with MG.

Presence of a functional vitamin D receptor does not correlate with vitamin D3 phenotypic effects in myeloid differentiation

Although VDR is expressed in all the acute myeloid leukemia cell populations studied, most of these leukemias do not exhibit any phenotypic response when exposed to VD. To determine whether VD resistance is related to an altered VDR function, we performed an analysis of VDR expression, phosphorylation, DNA binding capacity and transactivation activity in several leukemic myeloid cell lines arrested at different levels of maturation. Our results indicate that VD induces a clear phenotypic effect, i.e. terminal monocytic differentiation, only in leukemic cells of M2/M3 (intermediate myeloblasts) and M5 (monoblasts) types but not in erythroid precursor cells, early leukemic myeloblasts (M0/M1 type) and promyelocytes (M3 type). VDR expression and function are evident in all the nuclear extracts obtained from the different myeloid cell lines after 12 h of VD treatment, but VD activation of monocytic differentiation is limited to a narrow differentiation window characterized by the M2 type myeloid cellular context.

2-deoxy-d-ribose-induced apoptosis in HL-60 cells is associated with the cell cycle progression by spermidine

The presence of polyamines is required for the apoptotic program triggered by 2-deoxy-D-ribose (dRib) in HL-60 cells, but their oxidative metabolites does not appear to be involved in the oxidative stress caused by the sugar. The present study points to a relationship between spermidine-induced G1 to S phase transition and the onset of dRib-induced apoptosis. Conversely, the G1 block induced by alpha-difluoromethylornithine (DFMO) is associated with a protective effect against dRib-induced cell suicide. Replenishment of the intracellular spermidine pool by exogenous putrescine and spermidine induces cell cycle progression and restores apoptotic levels. The present data indicate that the induction of cell cycle progression by spermidine is a condition facilitating the activation of the apoptotic process by dRib.

[Immunohistochemical study of colonic mucosa macrophages in children with Crohn's disease and ulcerative colitis]

In this research the histological characteristics of the macrophages on the colonic mucosa in Crohn's disease and ulcerative colitis were quantified and analysed. Twelve Crohn's disease, 19 ulcerative colitis and 10 specimen of the rectal mucosa, representing the control group according to the followed model, were studied: I period (PI) = pre-treatment, II period (PII) = up two years of evolution and III period (PIII) = more than two years of evolution. The macrophages were identified in a colonic mucosa by the monoclonal CD68 through the immunoperoxidase method. The macrophages quantification was done by chromatic computer images analysis, that express the area (mm2) used by the CD68 positive cells, in percentage. The percentage of the area used by the macrophages was increased in both diseases, in all the studied periods, when compared with the control group, but without statistic significance. The macrophages' distribution inside the control group mucosa was subepithelial, while in the illness group, it reached all the mucosa that was concentrated on the basis of ulcers and all long the fissures. On the Crohn's disease the CD68 positive cells facilited the identification of the microgranulomas, sometimes unnoticed in the hematoxiline-eosine. Although there was no difference between patients and control group in the macrophages area, the difference in the distribution could suggest the macrophages' participation on the injure in both diseases although they do not permit a differential diagnosis because of the variety of the values. The CD68 did not identify the different functional status of the macrophages, but their position in the mucosa suggest that, in terms of fissures and ulcers, their mainly function should be the phagocitosis and in the other cases, they have been the cells that should show the antigens and that recruit the other inflammatory cells.

N1,N12-bis(ethyl)spermine effect on growth of cis-diamminedichloroplatinum(II)-sensitive and -resistant human ovarian-carcinoma cell lines

The results presented here demonstrate that a cis-diamminedichloroplatinum(II) (DDP)-resistant human ovarian-carcinoma cell line is also cross-resistant to the spermine analogue N1,N12-bis(ethyl)spermine (BESPM). We report that C13* cells, which are approximately 20-fold resistant to DDP, similarly showed 7-fold resistance to BESPM by colony-forming assay with an IC50 value of 24.6 +/- 2 microM vs. 3.4 +/- 0.8 microM of 2008 cells. Resistance appears to be the result of many effects, such as different morphological and functional modifications of mitochondria. Furthermore, although BESPM accumulation was almost identical in sensitive and resistant cells, the intracellular polyamine pool of the 2 cell lines was differentially affected by this polyamine analogue. In fact, when spermidine (SPD) was still detectable in C13* cells, in 2008 cells it was not, and the spermine (SPM) content was always more markedly reduced in sensitive cells than in the resistant variant. The lower polyamine content of 2008 cells could be related to a higher degree of induction of spermidine/ spermine N1-acetyltransferase (SSAT) activity by BESPM in sensitive cells than in their resistant counterpart. Despite the observed cross-resistance, the combination of the 2 drugs resulted in supra-additive and synergistic effects in both cell lines, depending on concentration, as assessed by median-effect analysis of the survival data. The effectiveness of this combination was also confirmed by the increased accumulation of cells in the G2/M phase of the cell cycle in both cell lines. Taken together, these data suggest that BESPM effect on cell growth of DDP-sensitive and DDP-resistant cells involves multiple mechanisms that are differently modulated by the DDP-resistant phenotype.

Modulation of apoptosis in human lymphocytes by adenosine analogues

We previously described that 2-chloroadenosine (2CA) and 2-chloro-2'-deoxyadenosine (2CdA) induced apoptosis in human peripheral blood mononuclear cells (PBMC). In this study we tested different adenosine analogues on PBMC and we found that the modifications introduced in the 2CA structure prevented the molecule from exerting its apoptotic effect. On the other hand, substitutions on 2CdA are tolerated, although with a significant decrease in activity.

Age-related modifications of the human alphabeta T cell repertoire due to different clonal expansions in the CD4+ and CD8+ subsets

We have studied the effects of a life-long antigen stimulation on the clonal heterogeneity of human peripheral T cell subsets, as defined by their CD45 isoform expression. CD4+ or CD8+ T cells were obtained from healthy donors ranging in age from 20 to 100 years, and sorted into CD45RA+ and CD45RO+ populations. A modified PCR-heteroduplex analysis was then used to directly compare the TCR Vbeta clonal make up of either compartment pair. We find that the CD4+ T cell repertoire remains largely polyclonal throughout life, since CD4+ expanded clones are rare and accumulate predominantly in the CD45RO+ compartment of exceptionally old donors (100 years old). In contrast, the CD8+ T cell subset contains expanded clones which are already detectable in young adults and become very frequent in 70- to 75-year-old donors in both CD45RA+ and CD45RO+ compartments analyzed. Interestingly, some expanded clones are detectable in the CD45RA+ or in both CD45RA+ and CD45RO+ compartments of either CD4+ or CD8+ T cells. These results indicate that the age-dependent accumulation of expanded clones starts earlier and is more pronounced in the CD8+ than in the CD4+ T cell subset, reinforcing the concept that clonal expansion in the two subsets is controlled by substantially different mechanisms. Furthermore, whereas the finding of expanded CD45RO+ T cell clones is explained by antigen-driven proliferation, the detection of expanded clones in the CD45RA+ or in both CD45RA+ and CD45RO+ compartments would support the hypothesis of reversion from the CD45RO+ to the CD45RA+ phenotype after antigen encounter.

Antisense inhibition of Bax mRNA increases survival of terminally differentiated HL60 cells

Cell sensitivity to programmed cell death is primarily modulated by members of the Bcl-2 family, as the balance of homodimer or heterodimer formation between proapoptotic and antiapoptotic members defines apoptosis susceptibility in the great majority of cellular contexts. It is, therefore, important to clarify if the Bax protein is limiting for activation of the genetic program of programmed cell death or can be complemented by different Bcl-2 family members, such as Bak or Bad. To gain some insight into the role of Bax in the molecular mechanisms of apoptosis of myeloid cells, we inhibited this gene in all-trans-retinoic acid (ATRA)-treated HL60 cells using the methodology of antisense oligodeoxynucleotides (AS-ODN). Our results indicate that Bax inhibition has no effect on the proliferation and differentiation capacity of HL60 cells. Instead, the survival rate of terminally differentiated Bax-inactivated HL60 (Bax(-) HL60) cells is almost three times higher in respect to control cultures, indicating that in mature granulocytes Bax is not efficiently complemented by others members of the Bcl-2 family proteins.

[Immunohistological study of T-lymphocytes (total and helper) and B-lymphocytes of the colonic mucosa in children with Crohn's disease and non-specific ulcerative colitis]

For one to understand better the immunological mechanism in the colonic mucosae of inflammatory bowel disease, 19 children with ulcerative colitis and 12 children with Crohn's disease were studied. The inflammatory cells identified by the immunoperoxidase technique and specific markers for total T lymphocytes (CD3), helper T lymphocytes (CD4) and B lymphocytes (CD20) in differents evolutionary periods of the disease were analysed. PI (before treatment), PII (until two years of treatment) and PIII (with more than two years of treatment). In general, all marker studied in this research, presented higher averages if comparing to the control group with different degrees of significance in the different studied periods. The marker CD3, of the total T lymphocyte, increased in the epithelial (superficial and glandular) and in the lamina propria of the involved mucosae in relation to the controlled ones, was diffusely distributed over the mucosae, concentrating itself around the microgranulomas and the nodules lymphoids. In Crohn's disease, PI, its average differed significantly from the controlled ones. Similar behave was seen in the marker CD20 of the lymphocytes in the involved mucosae, whole averages were superior in relation to the controlled ones; thought, only in the PI of the Crohn's disease this difference had been significant. The immunochromatic cells CD3 distributed themselves diffusely over the involved mucosae, concentrating themselves in the interior of the lymphoides nodules and in the injured areas, near the macrophages. The marker CD4, of helper T lymphocyte also presented in the involved mucosae high averages in relation to the controlled mucosae, but without estatistic significance. The CD4 cells distributed themselves diffusely over the whole thickness of the involved mucosae, concentrating themselves around the lymphoids nodules and microgranulomas. These results confirm the participation of these elements in the pathogenesis of inflammatory bowel disease, but did not permit the establishment of any discriminatory criteria between ulcerative colitis and Crohn's disease. The results of positive correlation between the increased of CD4 and CD20 in ulcerative colitis and CD3 and CD20 in Crohn's disease show clearly the immunoregulation action of the CD4+ cells over clonal expansion and the differenciation of the B lymphocytes from plasmocytes and the IgG syntese.

[Protein hydrolysate as a dietetic resource]

OBJECTIVE: The central goal of this paper was to study the application of beef meat and poultry (turkey and chicken) hydrolysates to the preparations used in our Brazilian current feeding practices. METHODS: The various kinds of meat were hydrolyzed with fresh pineapple under similar conditions to those daily used at home. The selection of three types of preparation was dependent on whether their contents included starch or gelatin and liquid, like soup, mousse and fruit-shake. Hydrolysate were added to the preparations as part of the liquid content of their recipes. The acceptability of the preparations was checked out by employing the hedonic-scale affective test with untrained tasters. Variance analysis and the Tukeýs test were performed with a 5% level of significance for the results.RESULTS: The selected recipes were the following: bitterroot soup, fruit and vegetable-shakes and grape mousse, all of them containing starch or gelatin as an element to camouflage the bitter taste of the aminoacids. The preparations were well accepted: approximately 76% of the tasters reported having liked the soup at least somewhat; as to the shakes, more than 50% gave positive answers, and as to the mousse, approximately 88% reported having liked it. There were no statistically significant differences (p< 0.05) concerning the application of the three hydrolysates in all the preparations tested. CONCLUSIONS: The use of hydrolysed meat to replace liquid content of recipes is highly practicable, requiring only an adequate selection of recipes and their ingredients, that should include starch and gelatin in order to get fully satisfactory products. These preparations might serve as a basis for other ones, adapted to each diet.

Neutral endopeptidase-24.11 (NEP) activity in human fibroblasts during development and ageing

Neutral endopeptidase-24.11 (NEP, EC 3.4.24.11) is a cell surface Zn metallopeptidase that hydrolyzes bioactive regulatory peptides. Using a spectrofluorimetric procedure, we assessed NEP activity in plasma membranes of normal human skin and lung fibroblasts. We found a considerable increase in NEP activity during fetal-to-adult transition. Adult skin fibroblasts from an old donor exhibited significantly higher levels of NEP activity than cells from young donors. Interestingly, however, the NEP activity of fibroblasts from a centenarian donor was similar to that of cells from young donors. Increased levels of NEP activity were also found in in vitro aged lung fibroblasts. Finally, adrenocorticotropin hormone (ACTH (1-24)), a regulatory peptide that can be cleaved by NEP, provoked an increase in enzymic activity in fetal and young adult donor fibroblasts and a decrease in this activity in fibroblasts from adult and old donors. This finding suggests that ageing may affect NEP activity.

[Immunohistochemical study of HLA-DR expression in superficial epithelium and in lamina propria of colonic mucosa in children with Crohn's disease and nonspecific ulcerative colitis]

Some researches have stressed the importance of expression HLA-DR on the superficial epithelium and on the lamina propria of the colonic mucosa of patients with ulcerative colitis and Crohn disease. In this research the histological characteristics of the expression HLA-DR on the resident mucosa of both these illness were quantified and analysed. Twelve Crohn disease, 19 ulcerative colitis and 10 specimen of the rectal mucosa, representing the control group according to the following model were studied: I period = pre-treatment, II period = up two years of evolution and III period = more than two years of treatment. The expression HLA-DR was identified by the monoclonal HLA-DR (DAKO) in the resident mucosa specimen by the immunoperoxidase method. The quantification of the expression HLA-DR on the lamina propria was done through the chromatic computer images analysis that express the area (micron2) used by the positive HLA-DR cells and the superficial epithelium in percentage by a semi quantifier evaluation. On the lamina propria of the illness mucosa, the expression HLA-DR was increased in all the studied periods when compared with the control group, but without statistics differences. The distribution of the expression HLA-DR on the lamina propria was done to the corresponding localization to the macrophages and to the B lymphocytes. The superficial colonial epithelium of the ulcerative colitis and Crohn disease patients was in 86.95% and in 80.96% respectively HLA-DR positive in the three periods. The superficial epithelium of all the rectal mucosa of the control group did not show the HLA-DR expression. The presence of the HLA-DR expression on the superficial colonial epithelium of the ulcerative colitis and Crohn disease patients and its absence in the control group was a very important found in this research. It is a consense among several authors that the HLA-DR expression represents a intense local action of the inductorious cytokines of this expression in the colonic mucosa of the ulcerative colitis and Crohn disease patients, representing its activation in a answer to the invasor antigen in the intestinal mucosa. The study of the HLA-DR expression in the lamina propria was not conclusive, because the result did not represent a significative difference in relation with the control.

Growth properties and growth factor responsiveness in skin fibroblasts from centenarians

Human fibroblast cultures, which have a finite replicative lifespan in vitro, are the most widely used model for the study of senescence at the cellular level. An inverse relationship between replicative capability and donor age has been reported in human fibroblast strains. We studied the growth capacity of fibroblast primary cultures derived from people whose lifespan was as closer as possible to the expected maximum human lifespan, i.e. people over one hundred. Our data suggest that outgrowth of fibroblasts from biopsies, growth kinetics at different population doubling levels, capability to respond to a classical mitogenic stimulus (such as 20% serum) and a variety of growth factors, were remarkably similar in fibroblasts from centenarians and young controls. On the whole, our data challenge the tenet of a simple and strict relationship between in vivo aging and in vitro proliferative capability of human fibroblasts, at least at the individual level.

Polyamine depletion protects HL-60 cells from 2-deoxy-D-ribose-induced apoptosis

We investigated the involvement of natural polyamines in HL-60 cell death triggered by exposure to 2-deoxy-D-ribose (dRib). In contrast to previous studies, exogenous polyamines failed to protect HL-60 cells against apoptosis caused by dRib. Moreover, in our experimental conditions, depletion of intracellular levels of putrescine and spermidine by alpha-difluoromethylornithine (DFMO) delayed the onset of apoptosis by at least a day or so. Exogenous polyamines reversed the beneficial effect of DFMO and restored the apoptotic levels observed in dRib-treated cells. We suggested that polyamines, especially putrescine and spermidine, act as facilitating factors in the induction of apoptosis triggered by dRib in HL-60 cells.

The highly reducing sugar 2-deoxy-D-ribose induces apoptosis in human fibroblasts by reduced glutathione depletion and cytoskeletal disruption

2-deoxy-D-Ribose (dRib), the most reducing sugar, induces apoptosis in normal human fibroblasts, as judged by cytoplasmic shrinkage, chromatin condensation, DNA fragmentation and mitochondrial depolarization. This effect is independent from culture conditions, such as cell density and the presence or absence of serum in the culture milieu, suggesting that dRib-induced apoptosis is cell cycle-independent. dRib was found also to provoke disruption of the actin filament network and detachment from the substratum, while at the same time, interestingly, it increases the expression of several integrins and cell adhesion molecules. Furthermore, dRib was found to reduce the intracellular levels of reduced glutathione (GSH). The apoptotic process was not affected by the macromolecular-synthesis inhibitors cycloheximide and actinomycin D. On the contrary, the antioxidant N-acetyl-L-cysteine (NAC) fully blocks the dRib-induced apoptosis by preventing GSH depletion, while it also inhibits actin-filament-network disruption and mitochondrial depolarization. The above indicate that dRib induces apoptosis in human fibroblasts by a mechanism involving glutathione metabolism and oxidative stress, as well as disturbance of cytoskeletal integrity and cell adhesion.