Increased calcium uptake and improved trabecular bone properties in intestinal alkaline phosphatase knockout mice.

Previous studies have demonstrated a negative correlation between intestinal alkaline phosphatase (IAP) activity and calcium (Ca) absorption in the gut, as IAP acts as a protective mechanism inhibiting high Ca entry into enterocytes, preventing Ca overload. Here we evaluated Ca absorption and bone properties in knockout mice (KO) completely devoid of duodenal IAP (Akp3 -/- mice). Female C57BL/6 control mice (WT, n = 7) and KO mice (n = 10) were used to determine Ca absorption in vivo and by in situ isolated duodenal loops followed by histomorphometric analysis of duodenal villi and crypts. Bone mineral density, morphometry, histomorphometry and trabecular connectivity and biomechanical properties were measured on bones. We observed mild atrophy of the villi with lower absorption surface and a significantly higher Ca uptake in KO mice. While no changes were seen in cortical bone, we found better trabecular connectivity and biomechanical properties in the femurs of KO mice compared to WT mice. Our data indicate that IAP KO mice display higher intestinal Ca uptake, which over time appears to correlate with a positive effect on the biomechanical properties of trabecular bone.

[Dog saliva causes rare and life-threatening infection]. / Hondenspeeksel veroorzaakt zeldzame en levensbedreigende infectie.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening syndrome. Due to its heterogeneous presentation, nonspecific findings, and rarity, this diagnosis is often initially overlooked. This contributes to the high mortality. Early recognition in the emergency room, leading to prompt adequate treatment, can benefit the prognosis of this often devastating condition. CASE DESCRIPTION: A 54-year-old man visited the Emergency department with shock, fever and cytopenias. Thorough further investigation lead to CapnocytophagaCanimorsusbacteraemia with secondary HLH as the cause. He was successfully treated with antibiotics, steroids and etoposide. CONCLUSION: Consider the diagnosis of HLH in any severely ill patient with fever, multi-organ failure and cytopenias. If the diagnosis of HLH is established, it is crucial to identify and treat the underlying cause. By increasing attention to this life-threatening condition the high mortality could be decreased, as shown in this case report.

hnRNP proteins: localization and transport between the nucleus and the cytoplasm.

The proteins of heterogeneous nuclear ribonucleoprotein (hnRNP) complexes are among the most abundant proteins in the nucleus. They bind nascent pre-mRNAs and remain associated with them through their nuclear processing into mRNA. Recent findings indicate roles for hnRNP proteins in the biogenesis of mRNA and reveal a surprising intracellular localization pathway for these proteins. Several of the hnRNP proteins shuttle continuously between the nucleus and the cytoplasm, and the reaccumulation of the exported hnRNP proteins in the nucleus occurs by a novel process that is dependent on transcription by RNA polymerase II. These findings suggest possible novel functions for hnRNP proteins in the cytoplasm and in the nucleocytoplasmic transport of mRNA.

A novel heterogeneous nuclear RNP protein with a unique distribution on nascent transcripts.

Immediately after the initiation of transcription in eukaryotes, nascent RNA polymerase II transcripts are bound by nuclear proteins resulting in the formation of heterogeneous nuclear ribonucleoprotein (hnRNP) complexes. hnRNP complexes from HeLa cell nuclei contain greater than 20 major proteins in the molecular mass range of 34,000-120,000 D. Among these are the previously described A, B, and C groups of proteins (34,000-43,000 D) and several larger, and as yet uncharacterized, proteins. Here we describe the isolation and characterization of a novel hnRNP protein termed the L protein (64-68 kD by mobility in SDS-polyacrylamide gels). Although L is a bona fide component of hnRNP complexes, it also appears to be a different type of hnRNP protein from those previously characterized. A considerable amount of L is found outside hnRNP complexes, and monoclonal antibodies to the L protein also strongly stain unidentified discrete nonnucleolar structures, in addition to nucleoplasm, in HeLa cell nuclei. Interestingly, the same antibodies stain the majority of nonnucleolar nascent transcripts from the loops of lampbrush chromosomes in the newt, but the most intense staining is localized to the landmark giant loops. The L protein is the first protein of giant loops identified so far, and antibodies to it thus provide a useful tool with which to study these unique RNAs. In addition, isolation and sequencing of cDNA clones for the L protein from human cells predicts a glycine- and proline-rich protein of 60,187 D, which contains two 80 amino acid segments only distantly related to the RNP consensus sequence-type RNA-binding domain. The L protein, therefore, is a new type of hnRNP protein.

Transcription-dependent and transcription-independent nuclear transport of hnRNP proteins.

Heterogeneous nuclear RNAs and specific nuclear proteins form heterogeneous nuclear ribonucleoprotein complexes (hnRNPs), one of the most abundant components of the nucleus. In mitosis, as the nuclear envelope breaks down, hnRNPs disperse throughout the cell. At the end of mitosis, hnRNPs dissociate and their proteins are transported into the daughter cell nuclei separately. Some are transported immediately (early group), while others are transported later (late group). Transport of the late group appears to require transcription by RNA polymerase II, in that inhibitors of this polymerase cause the late proteins to remain in the cytoplasm. Thus, there are two modes, transcription-dependent and transcription-independent, for the transport of nuclear proteins.

Cell cycle-regulated phosphorylation of the pre-mRNA-binding (heterogeneous nuclear ribonucleoprotein) C proteins.

Heterogeneous nuclear ribonucleoprotein (hnRNP) complexes, the structures that contain heterogeneous nuclear RNA and its associated proteins, constitute one of the most abundant components of the eukaryotic nucleus. hnRNPs appear to play important roles in the processing, and possibly also in the transport, of mRNA. hnRNP C proteins (C1, M(r) of 41,000; C2, M(r) of 43,000 [by sodium dodecyl sulfate-polyacrylamide gel electrophoresis]) are among the most abundant pre-mRNA-binding proteins, and they bind tenaciously to sequences relevant to pre-mRNA processing, including the polypyrimidine stretch of introns (when it is uridine rich). C proteins are found in the nucleus during the interphase, but during mitosis they disperse throughout the cell. They have been shown previously to be phosphorylated in vivo, and they can be phosphorylated in vitro by a casein kinase type II. We have identified and partially purified at least two additional C protein kinases. One of these, termed Cs kinase, caused a distinct mobility shift of C proteins on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These phosphorylated C proteins, the Cs proteins, were the prevalent forms of C proteins during mitosis, and Cs kinase activity was also increased in extracts prepared from mitotic cells. Thus, hnRNP C proteins undergo cell cycle-dependent phosphorylation by a cell cycle-regulated protein kinase. Cs kinase activity appears to be distinct from the well-characterized mitosis-specific histone H1 kinase activity. Several additional hnRNP proteins are also phosphorylated during mitosis and are thus also potential substrates for Cs kinase. These novel phosphorylations may be important in regulating the assembly and disassembly of hnRNP complexes and in the function or cellular localization of RNA-binding proteins.

Distinct RNP complexes of shuttling hnRNP proteins with pre-mRNA and mRNA: candidate intermediates in formation and export of mRNA.

Nascent pre-mRNAs associate with hnRNP proteins in hnRNP complexes, the natural substrates for mRNA processing. Several lines of evidence indicate that hnRNP complexes undergo substantial remodeling during mRNA formation and export. Here we report the isolation of three distinct types of pre-mRNP and mRNP complexes from HeLa cells associated with hnRNP A1, a shuttling hnRNP protein. Based on their RNA and protein compositions, these complexes are likely to represent distinct stages in the nucleocytoplasmic shuttling pathway of hnRNP A1 with its bound RNAs. In the cytoplasm, A1 is associated with its nuclear import receptor (transportin), the cytoplasmic poly(A)-binding protein, and mRNA. In the nucleus, A1 is found in two distinct types of complexes that are differently associated with nuclear structures. One class contains pre-mRNA and mRNA and is identical to previously described hnRNP complexes. The other class behaves as freely diffusible nuclear mRNPs (nmRNPs) at late nuclear stages of maturation and possibly associated with nuclear mRNA export. These nmRNPs differ from hnRNPs in that while they contain shuttling hnRNP proteins, the mRNA export factor REF, and mRNA, they do not contain nonshuttling hnRNP proteins or pre-mRNA. Importantly, nmRNPs also contain proteins not found in hnRNP complexes. These include the alternatively spliced isoforms D01 and D02 of the hnRNP D proteins, the E0 isoform of the hnRNP E proteins, and LRP130, a previously reported protein with unknown function that appears to have a novel type of RNA-binding domain. The characteristics of these complexes indicate that they result from RNP remodeling associated with mRNA maturation and delineate specific changes in RNP protein composition during formation and transport of mRNA in vivo.

Differential binding of heterogeneous nuclear ribonucleoproteins to mRNA precursors prior to spliceosome assembly in vitro.

We have investigated the composition of the earliest detectable complex (H) assembled on pre-mRNA during the in vitro splicing reaction. We show that most of the proteins in this complex correspond to heterogeneous nuclear ribonucleoproteins (hnRNP), a set of abundant RNA-binding proteins that bind nascent RNA polymerase II transcripts in vivo. Thus, these studies establish a direct parallel between the initial events of RNA processing in vitro and in vivo. In contrast to previous studies, in which total hnRNP particles were isolated from mammalian nuclei, we determined the hnRNP composition of complexes assembled on individual RNAs of defined sequence. We found that a unique combination of hnRNP proteins is associated with each RNA. Thus, our data provide direct evidence for transcript-dependent assembly of pre-mRNA in hnRNP complexes. The observation that pre-mRNA is differentially bound by hnRNP proteins prior to spliceosome assembly suggests the possibility that RNA packaging could play a central role in the mechanism of splice site selection, as well as other posttranscriptional events.

Association of nonribosomal nucleolar proteins in ribonucleoprotein complexes during interphase and mitosis.

rRNA precursors are bound throughout their length by specific proteins, as the pre-rRNAs emerge from the transcription machinery. The association of pre-rRNA with proteins as ribonucleoprotein (RNP) complexes persists during maturation of 18S, 5.8S, and 28S rRNA, and through assembly of ribosomal subunits in the nucleolus. Preribosomal RNP complexes contain, in addition to ribosomal proteins, an unknown number of nonribosomal nucleolar proteins, as well as small nucleolar RNA-ribonucleoproteins (sno-RNPs). This report describes the use of a specific, rapid, and mild immunopurification approach to isolate and analyze human RNP complexes that contain nonribosomal nucleolar proteins, as well as ribosomal proteins and rRNA. Complexes immunopurified with antibodies to nucleolin-a major nucleolar RNA-binding protein-contain several distinct specific polypeptides that include, in addition to nucleolin, the previously identified nucleolar proteins B23 and fibrillarin, proteins with electrophoretic mobilities characteristic of ribosomal proteins including ribosomal protein S6, and a number of additional unidentified proteins. The physical association of these proteins with one another is mediated largely by RNA, in that the complexes dissociate upon digestion with RNase. Complexes isolated from M-phase cells are similar in protein composition to those isolated from interphase cell nuclear extracts. Therefore, the predominant proteins that associate with nucleolin in interphase remain in RNP complexes during mitosis, despite the cessation of rRNA synthesis and processing in M-phase. In addition, precursor rRNA, as well as processed 18S and 28S rRNA and candidate rRNA processing intermediates, is found associated with the immunopurified complexes. The characteristics of the rRNP complexes described here, therefore, indicate that they represent bona fide precursors of mature cytoplasmic ribosomal subunits.

[Organizational appropriateness evaluation of hospital discharges related to DRGs at high risk of inappropriateness in a pediatric observation ward from 2000 to 2004]. / Valutazione della appropriatezza organizzativa dei ricoveri ordinari attribuiti ai DRG ad alto rischio di inappropriatezza effettuati in un Reparto di Osservazione Pediatrica nel periodo 2000-2004.

The aim of the study is to measure and to describe organizational appropriateness of a Paediatric Temporary Observation Ward in the Emergency Department. We selected hospital discharges related to 43 DRGs at high risk of inappropriateness (DPCM 29/11/2001); we studied the relationship between appropriateness and patient's or discharge characteristics. We also investigated the inappropriateness to find tools for improving ward's efficiency. Assessment of selected paediatric clinical records was performed using PRUO protocol and showed that 41.5% of hospital discharges are completely appropriated and only 13.8% are completely not appropriated and, consequently, could be provided in a different organizational setting. Inappropriateness in our study is lower than the expected one; this finding shows that the ward under investigation is able to provide health assistance with good level of appropriateness. The used tool to evaluate appropriateness is a modified PRUO version, specific for pediatric hospital stays. Pediatric PRUO protocol is easy to be applied even if reasonable and shared evaluation criteria do not seem able to recognise some peculiar characteristics of Pediatric Temporary Observation Ward in the Emergency Department.

Immunopathological modifications in the rectal mucosa from an animal model of food allergy.

AIM: The aim is to determine immunopathological modifications in rectal mucosa from rabbit after local challenge in sensitized animals with ovalbumin (OVA). EXPERIMENTAL DESIGN: Thirty rabbits divided into three groups: G1: normal, G2: subcutaneously OVA sensitized, G3: sensitized, locally OVA challenged and sampled 4 hours after challenge. Specific anti-OVA IgE levels were evaluated by passive cutaneous anaphylaxis test (PCA). In each group 200 high microscopical power fields (HPF) were counted. Results were expressed as arithmetic mean and SE. Statistical analysis was made using Student t test. Anti-CD4, CD5, micro chain, CD25 and RLA II monoclonal antibodies were used. Avidin biotin horseradish peroxidase system was used. RESULTS: CD 4: G1: 8.3 +/- 0.06; G2: 13.4 +/- 0.08 and G3: 8.25 +/- 0.06. CD 5: G1: 7.3 +/- 0.05; G2: 9.4 +/- 0.05 and G3: 11.3 +/- 0.06. CD 25: G1: 13 +/- 0.08; G2: 15.1 +/- 0.13 and G3: 25.5 +/- 0.15. mu chain: G1: 10.4 +/- 0.06; G2: 3.8 +/- 0.02 and G3: 6.0 +/- 0.10. RLA II (DR): G1: 11.6 +/- 0.05; G2: 19.2 +/- 0.09 and G3: 19.1 +/- 0.11. In all cases, experimental groups (G2 and G3) presented statistical significant differences vs. control group (G1) (p < 0.001). CONCLUSIONS: Interleukin-2 receptor (CD25+ cells) increase in experimental groups. Cells expressing micro chain decreased in G2 and G3 likely due to activation of B cells and subsequent expression of other immunoglobulin chains in cell surface. RLA II expression is higher in G2 and G3. This receptor is considered an activation marker expressed by macrophages, T and B cells. We conclude that obtained data are important to elucidate immunopathology of local anaphylactic reaction in rectal mucosa from systemic sensitized animals.

Heterogeneous nuclear ribonucleoprotein complexes from Xenopus laevis oocytes and somatic cells.

HnRNP proteins have been implicated in most stages of cellular mRNA metabolism, including processing, nucleocytoplasmic transport, stability, and localization. Several hnRNP proteins are also known to participate in key early developmental decisions. In order to facilitate functional studies of these pre-mRNA- and mRNA-binding proteins in a vertebrate organism amenable to developmental studies and experimental manipulation, we identified and purified the major hnRNP proteins and isolated the hnRNP complex from Xenopus laevis oocytes and somatic cells. Using affinity chromatography and immunological methods, we isolated a family of >15 abundant single-stranded nucleic acid-binding proteins, which range in apparent molecular weight from approximately 20 kDa to >150 kDa, and with isoelectric points from <5 to >8. Monoclonal antibodies revealed that a subset of these proteins are major hnRNP proteins in both oocytes and somatic cells in culture, and include proteins related to human hnRNP A2/B1/B2 and hnRNP K. UV crosslinking in living cells demonstrated that these proteins bind poly(A)+ RNA in vivo. Immunopurification using a monoclonal antibodyto X. aevishnRNPA2 resulted in the isolation of RNP complexes that contain a specific subset of single-stranded nucleic acid-binding proteins. The protein composition of complexes isolated from somatic cells and from oocyte germinal vesicles was similar, suggesting that the overall properties and functions of hnRNP proteins in these two cell types are comparable. These findings, together with the novel probes generated here, will also facilitate studies of the function of vertebrate RNA-binding proteins using the well characterized X. laevis oocyte and early embryo as experimental systems.

Cloning of a human gene closely related to the genes coding for the c-myc single-strand binding proteins.

Southwestern screening of human fibroblast cDNAs with an upstream element of the alpha2(I) collagen promoter (Box 5A) has led to the identification of a novel gene product (RBMS3). RBMS3 contains two pairs of RNA binding motifs and is very closely related to the structure of the c-myc gene single-strand binding proteins (MSSPs). MSSPs are believed to regulate DNA replication, transcription, apopotosis and cell cycle progression by interacting with the C-MYC protein. Consonant with this postulate, RBMS3 binds in vitro to the minus strand of Box 5A and transactivates transcription in the chimeric GAL4 hybrid system. However, the RBMS3 protein mostly localizes to the cytoplasm of transfected cells, in addition to binding strongly in vitro to synthetic poly-U and poly-A oligoribonucleotides. Finally, overexpression in transfected fibroblasts of RBMS3 with and without a nuclear localization signal has no effect on Box 5A-driven transcription. The results thus exclude RBMS3 involvement in the transcriptional regulation of COL1A2 and strongly suggest a cytoplasmic function of this new member of the MSSP family. As part of the initial characterization of RBMS3 we have also established that the gene resides on human chromosome 3p23-p24 and is widely expressed in the embryo and in the adult organism.

[Intraepithelial enteroendocrine cells in cecum and appendix from ovoalbumin sensitized rabbits]. / Células enteroendocrinas intraepiteliales en ciego y apéndice de conejos sensibilizados con ovoalbumina.

Intraepithelial enteroendocrine cells (IEC) produce peptides which influence motility, secretion and absorption of nutrients. Recently the role of these cells in the immune mucosal system is under study. The aim of the present study was to evaluate the modifications in number of IEC in cecum and appendix from Ovalbumin (OVA) sensitized rabbits. Twenty adult New Zealand rabbits were separated in two groups: Group 1 (G1 = 10) not sensitized normal control. Group 2 (G2 = 10) were sensitized twice intraperitoneally with 70 mg OVA and 30 mg ALUM/ml (aluminium hydroxide). Anti OVA specific IgE was evaluated by means of PCA test (passive cutaneous anaphylaxis). Samples form cecum and appendix were fixed in buffered formaldehyde 10%, paraffin embedded and stained with anti-Chromogranin A for neuroendocrine cells. 400 high power fields were counted in each animal, referred as IEC/100 enterocytes. In cecum surface epithelium and crypt were considered. Surface epithelium, deep crypts and superficial crypts were evaluated in appendix. Results showed in cecum in G1:1,6 IEC/100 enterocytes in surface epithelium and 3/100 in crypts; G2 6 IEC/100 in surface epithelium and 12/100 in crypts. The difference between G1 and G2 was statistically significant (p < 0.05). In appendix surface epithelium from G1 showed 5.2/100 while G2 5.4/100. Superficial crypts 8.5 (G1) and 11.3 (G2) (p < 0.05) and deep crypts 4.9 (G1) and 8.5 (G2) (p < 0.01). The results showed that OVA-sensitized animals presented increment in the number of IEC in surface epithelium and crypts which may indicate a relationship between these cells and rabbit mucosal immune system.

[Intraepithelial T cell population in ileum from ovalbumin sensitized rabbit]. / Población intraepitelial de linfocitos T en íleon de conejos sensibilizados con ovoalbumina.

We characterize the intraepithelial T cell population of terminal ileum from intraperitoneally OVA-sensitized New Zealand rabbit after oral challenge. High anti-OVA specific IgE levels elicited after sensitization were evaluated by positive passive cutaneous anaphylaxis (PCA) at 160 fold dilutions. Anaphylactic response in gut after the oral challenge was confirmed by evaluation of edema in villi and marked mast cell degranulatin. Total T cells (CD5+), T cells subset (CD4+) and MHC II R-DQ positive cells expressed as the number of positive cells/1000 nuclei, were analyzed for each tissue. Positive cells were counted in 30 villi by light microscopy. The number of CD5+ cells was 122.5 cells/1000 nuclei. Activated cells in small bowel epithelium 8 hours after challenge in experimental group, expressed by MHC II R-DQ showed an increase: 32.2 as compared to control group: 12.6 positive cells/1000 nuclei (p < 0.05) and compared to experimental group 1 hour after challenge 9.3 (p < 0.05). We demonstrated an increment of activated T cells in gut epithelium of terminal ileum in OVA-sensitized group after oral challenge.

[Enteroendocrine cells modifications in Helicobacter pylori gastritis]. / Modificaciones de las células enteroendócrinas en gastritis por Helicobacter pylori.

OBJECTIVE: The aim of the present study was to analyze the modifications in the number and distribution of enteroendocrine cells (EEC) in antrum of patients with Helicobacter pylori (HE) gastritis. We also wanted to demonstrate their possible participation in the immune response. MATERIAL AND METHODS: Twenty-six (26) biopsies of gastric antrum from patients between the ages of 40 and 60 were used. Slides were stained with H&E, Giemsa for HP, and chromogranin A to visualize EEC. Five (5) patients were normal controls. Eleven (11) patients had antral chronic gastritis (ACG) with different grades of activity, and ten (10) patients had multifocal atrophic gastritis (MAG), both groups associated to HP. EEC were quantified in relation to 100 epithelial cells. Results were statistically compared. RESULTS: In the normal control group, EEC were sparsely distributed, deep in antral glands, with an average 19.51 EEC/100 epithelial cells. In ACG there were 12.01/100. Besides EEC were irregularly distributed, close to inflammatory areas, or near lymphoid follicles. CONCLUSION: The decrease in EEC is probably due to degranulation and later to a disappearance or inhibition of stem cells by inflammatory products in HP gastritis. The proximity of EEC to prominent inflammatory zones may indicate EEC modulate the immune response. They produce and excrete peptides that interact with membrane receptors found in T lymphocytes and macrophages.

[Uterine lipoma localized in the myometrium. Report of a case, and review of the literature]. / Lipoma uterino de localización miometrial. Presentación de un caso, con revisión de la literatura.

Lipomatous benign neoplasms of uterus are very rare entities in women. The present paper presents a case of uterine lipoma. The diagnosis is easily made at the time of surgery or at autopsy, but before this, they may lead to many problems in the differential diagnosis with another uterine tumors. Recent papers suggest the possibility of a preoperative diagnosis made by computed tomography and magnetic resonance imaging. Cytogenetic analysis of this benign tumor have established chromosomal abnormalities in sites that may control cell proliferation.

Effect of the treatment with alpha-macroglobulin on the development of experimental pancreatitis.

UNLABELLED: Alpha-macroglobulins are proteinase inhibitors. Monofluorophosphate increases alpha-macroglobulin levels in plasma, inducing a higher survival rate and lower pancreatic damage in rats with pancreatitis. The aim of this study was to evaluate the effect of alpha-macroglobulin on the development of pancreatitis. Pancreatitis was surgically induced in Sprague-Dawley rats divided into groups of 16 rats each and -subjected to the following intravenous treatments for 3 days: CONTROLS: pancreatitis without treatment, Enriched plasma: pancreatitis+-alpha-macroglobulin-enriched plasma, Normal plasma: pancreatitis+plasma with normal levels of alpha-macroglobulin, Saline Solution: pancreatitis+saline solution, Purified alpha-macroglobulin: pancreatitis+purified alpha-macroglobulin. After 14 days pancreatic damage was assessed using a score that measures: edema, fibrin, neutrophils, mononuclear leukocytes, necrosis, vascular congestion, thrombosis, hemorrhage and fibrosis. Pancreatic damage decreased and the percentage of animals with pancreatitis was lower in enriched-plasma and purified alpha-macroglobulin groups. We conclude that the intravenous administration of alpha-macroglobulins causes a reduction in the histological damage produced by pancreatitis.