Slow pyrolysis of Terminalia catappa L. municipal solid waste and the use of the aqueous fraction produced for bovine mastitis control

The Terminalia catappa L. tree is an ornamental and shade tree producter of a large amount of biological waste sent to landfills. Therefore, this plant constitutes so-called municipal solid wood waste (MSWW), which causes undesirable impacts on the environment, such as the generation of methane through the action of microorganisms. Sustainable solutions for the proper use and disposal of MSWW are a topic that has assumed great relevance at present due to the high quantities of MSWW generated worldwide. Pyrolysis constitutes an attractive alternative for the sustainable use of MSWW to produce higher value-added products. This study investigated the slow pyrolysis of Terminalia catappa L. fruit and the use of the aqueous fraction produced for bovine mastitis control. We obtained four fractions from the pyrolysis process, with average yields of the aqueous phase (36.22 ± 2.0 %), bio-oil (5.52 ± 0.4 %), biochar (37.55 ± 2.8 %) and gas (20.71 ± 2.0 %). The aqueous fraction was extracted with organic solvents and analyzed by gas chromatography coupled to mass spectrometry (GC‒MS). The extracts were composed mainly of phenols (50 %), furan derivatives, cyclic ketones, and others with lower contents, such as alcohols and esters. The aqueous fraction had bactericidal activity against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which are responsible for bovine mastitis. In addition, the fraction showed low cytotoxicity against a murine melanoma cell line from a C57BL/6J mouse, B16F10 cells and mouse peritoneal cells.

Vitamin D and calcium intakes in general pediatric populations: A French expert consensus paper

OBJECTIVES

Nutritional vitamin D supplements are often used in general pediatrics. Here, the aim is to address vitamin D supplementation and calcium nutritional intakes in newborns, infants, children, and adolescents to prevent vitamin D deficiency and rickets in general populations.

STUDY DESIGN

We formulated clinical questions relating to the following categories: the Patient (or Population) to whom the recommendation will apply; the Intervention being considered; the Comparison (which may be "no action," placebo, or an alternative intervention); and the Outcomes affected by the intervention (PICO). These PICO elements were arranged into the questions to be addressed in the literature searches. Each PICO question then formed the basis for a statement. The population covered consisted of children aged between 0 and 18 years and premature babies hospitalized in neonatology. Two groups were assembled: a core working group and a voting panel from different scientific pediatric committees from the French Society of Pediatrics and national scientific societies.

RESULTS

We present here 35 clinical practice points (CPPs) for the use of native vitamin D therapy (ergocalciferol, vitamin D2 and cholecalciferol, vitamin D3) and calcium nutritional intakes in general pediatric populations.

CONCLUSION

This consensus document was developed to provide guidance to health care professionals on the use of nutritional vitamin D and dietary modalities to achieve the recommended calcium intakes in general pediatric populations. These CPPs will be revised periodically. Research recommendations to study key vitamin D outcome measures in children are also suggested.

Guidelines for the management of children at risk of secondary bone fragility: Expert opinion of a French working group

The current French national guidelines were elaborated by a working group consisting of experts in the field of pediatric endocrinology, rheumatology, hepatogastroenterology, nephrology, and pneumology. A systematic search was undertaken of the literature published between 2008 and 2018 and indexed in PubMed. The recommendations developed were then validated by an external evaluation group comprising representatives from the various highly specialized fields in pediatrics, representatives of the societies and groups supporting the development of the guidelines, and representatives of different healthcare professions. The objective of these guidelines was to detail the current optimal management of children at risk of secondary bone fragility.

Synthesis, Biological Evaluation, and Molecular Modeling Studies of New Thiadiazole Derivatives as Potent P2X7 Receptor Inhibitors

Twenty new 2-(1H-pyrazol-1-yl)-1,3,4-thiadiazole analogs were synthetized to develop P2X7 receptor (P2X7R) inhibitors. P2X7R inhibition in vitro was evaluated in mouse peritoneal macrophages, HEK-293 cells transfected with hP2X7R (dye uptake assay), and THP-1 cells (IL-1β release assay). The 1-(5-phenyl-1,3,4-thiadiazol-2-yl)-1H-pyrazol-5-amine derivatives 9b, 9c, and 9f, and 2-(3,5-dimethyl-1H-pyrazol-1-yl)-5-(4-fluorophenyl)-1,3,4-thiadiazole (11c) showed inhibitory effects with IC₅₀ values ranging from 16 to 122 nM for reduced P2X7R-mediated dye uptake and 20 to 300 nM for IL-1β release. In addition, the in vitro ADMET profile of the four most potent derivatives was determined to be in acceptable ranges concerning metabolic stability and cytotoxicity. Molecular docking and molecular dynamics simulation studies of the molecular complexes human P2X7R/9f and murine P2X7R/9f indicated the putative intermolecular interactions. Compound 9f showed affinity mainly for the Arg268, Lys377, and Asn266 residues. These results suggest that 2-(1H-pyrazol-1-yl)-1,3,4-thiadiazole analogs may be promising novel P2X7R inhibitors with therapeutic potential.

Synthesis, characterization and biological activities of 3-aryl-1,4-naphthoquinones – green palladium-catalysed Suzuki cross coupling

Antifungal and trypanocidal aryl-1,4-naphthoquinones were prepared through an aqueous Suzuki protocol with reflux or microwave irradiation.

Endothelial function and mechanical arterial properties in children born small for gestational age: comparison with obese children

BACKGROUND

Early cardiovascular events preceding atherosclerosis have been reported in children born small for gestational age (SGA).

AIMS

To describe in detail the mechanical and functional arterial properties of SGA children and to compare the data to those of obese children in order to gain a better understanding of the severity of the dysfunction. A control group was required to overcome the lack of normal values.

METHODS

Three groups of 7- to 15-year-old children were included. Sixty children born SGA without obesity, 49 children with obesity and not SGA, and 55 controls underwent complete carotid and brachial arterial measurements using ultrasound and flow-mediated dilation. Biological measurements were performed in the obese and SGA groups.

RESULTS

Mean blood pressure and intima-media thickness were lower in SGA children than in the obese group (p < 0.001 and p = 0.004, respectively), but not different from the control group. Flow-mediated dilation was lower in SGA than in obese children and in controls (p < 0.001).

CONCLUSION

These data show that children born SGA have endothelial dysfunction with normal intima-media thickness.

Progressive osseous heteroplasia: a model for the imprinting effects of GNAS inactivating mutations in humans

CONTEXT

Heterozygous GNAS inactivating mutations are known to induce pseudohypoparathyroidism type 1a when maternally inherited and pseudopseudohypoparathyroidism when paternally inherited. Progressive osseous heteroplasia (POH) is a rare disease of ectopic bone formation, and studies in different families have shown that POH is also caused by paternally inherited GNAS mutations.

OBJECTIVE

Our purpose was to characterize parental origin of the mutated allele in de novo cases of POH and to draw phenotype/genotype correlations according to maternal or paternal transmission of a same GNAS mutation.

DESIGN AND SETTING

We conducted a retrospective study on patients addressed to our referral center for the rare diseases of calcium and phosphorus metabolism.

PATIENTS AND METHODS

We matched 10 cases of POH with cases of pseudohypoparathyroidism type 1a carrying the same GNAS mutations.

MAIN OUTCOME MEASURES

The parental origin of the mutated allele was studied using informative intragenic polymorphisms and subcloning of PCR products.

RESULTS

Paternal origin of GNAS mutations was clearly demonstrated in eight POH cases including one patient with mutation in exon 1. Genotype/phenotype analyses suggest that there is no direct correlation between the ossifying process and the position of the inactivating GNAS mutation. It is, however, more severe in patients in whom origin of the mutation is paternal. Severe intrauterine growth retardation was clearly evidenced in paternally inherited mutations.

CONCLUSIONS

Clinical heterogeneity makes genetic counseling a delicate matter, especially in which paternal inheritance is concerned because it can lead to either a mild expression of pseudopseudohypoparathyroidism or a severe expression of POH.

Prevalence of IGF1 deficiency in prepubertal children with isolated short stature

BACKGROUND/AIMS

'Primary IGF1 deficiency (IGFD)' is defined by low levels of IGF1 without a concomitant impairment in GH secretion in the absence of secondary cause. The aims of this study were to evaluate the prevalence of non-GH deficient IGFD in prepubertal children with isolated short stature (SS) and to describe this population.

METHODS

This retrospective study included all children with isolated SS seen in our Pediatric Endocrinology Unit from January 2005 to December 2007. Children were included based on the following criteria: i) SS with current height SDS < or = -2.5, ii) age > or = 2 years, and iii) prepubertal status. Exclusion criteria were: i) identified cause of SS and ii) current or past therapy with rhGH. IGF1-deficient children were defined as children without GH deficiency and with IGF1 levels below or equal to -2 SDS.

RESULTS

Among 65 children with isolated SS, 13 (20%) had low IGF1 levels, consistent with a diagnosis of primary IGFD, four of which were born small for gestational age and nine were born appropriate for gestational age. When compared with non-IGFD children, IGFD children had higher birth weight (-0.7 vs -1 SDS, P=0.02) and birth height (-1.7 vs -2 SDS, P=0.04) and more delayed bone age (2.6 vs 1.7 years, P=0.03).

CONCLUSION

The prevalence of primary IGFD was 20% in children with isolated SS. Concerning the pathophysiology, our study emphasizes that IGFD in some children may be secondary to nutritional deficiency or to maturational delay.

Localization of STRO-1, BMP-2/-3/-7, BMP receptors and phosphorylated Smad-1 during the formation of mouse periodontium

Bone morphogenetic proteins (BMPs) and BMP receptors (BMPRs) are known to regulate the development of calcified tissues by directing mesenchymal precursor cells differentiation. However, their role in the formation of tooth-supporting tissues remains unclear. We investigated the distribution pattern of STRO-1, a marker of mesenchymal progenitor cells and several members of the BMP pathway during the development of mouse molar periodontium, from the post-natal days 6 to 23 (D6 to D23). STRO-1 was mainly localized in the dental follicle (DF) at D6 and 13 then in the periodontal ligament (PDL) at D23. BMP-2 and -7 were detected in Hertwig's epithelial root sheath (HERS) and in DF, then later in differentiated periodontal cells. BMP-3 was detected after D13 of the periodontal development. BMPRs-Ib, -II, the activin receptor-1 (ActR-1) and the phosphorylated Smad1 were detected in DF and HERS at D6 and later more diffusely in the periodontium. BMPR-Ia detection was restricted to alveolar bone. These findings were in agreement with others data obtained with mouse immortalized DF cells. These results suggest that STRO-1 positive DF cells may be target of BMPs secreted by HERS. BMP-3 might be involved in the arrest of this process by inhibiting the signaling provided by cementogenic and osteogenic BMPs.

How do Shp2 mutations that oppositely influence its biochemical activity result in syndromes with overlapping symptoms?

Activating and inactivating mutations of SHP-2 are responsible, respectively, for the Noonan (NS) and the LEOPARD (LS) syndromes. Clinically, these developmental disorders overlap greatly, resulting in the apparent paradox of similar diseases caused by mutations that oppositely influence SHP-2 phosphatase activity. While the mechanisms remain unclear, recent functional analysis of SHP-2, along with the identification of other genes involved in NS and in other related syndromes (neurofibromatosis-1, Costello and cardio-facio-cutaneous syndromes), strongly suggest that Ras/MAPK represents the major signaling pathway deregulated by SHP-2 mutants. We discuss the idea that, with the exception of LS mutations that have been shown to exert a dominant negative effect, all disease-causing mutations involved in Ras/MAPK-mediated signaling, including SHP-2, might lead to enhanced MAPK activation. This suggests that a narrow range of MAPK signaling is required for appropriate development. We also discuss the possibility that LS mutations may not simply exhibit dominant negative activity.

Métabolisme minéral osseux: données récentes et perspectives relatives à l’ostéogenèse

Important data have recently been added to our knowledge of bone mineral metabolism in children. Molecular pathophysiology of several pediatric syndromes has been clarified. Specially, the components of endocrine and metabolic regulations are tightly related with regard to the trophicity of bone. On another hand, the impact of several therapeutics of bone diseases like biphosphonates, parathormone (PTH) or growth hormone on bone anabolism is now strongly emphasized. All these points are important for the becoming of bone pediatric diseases in the adult life. Here we analyze the essential components of mineral metabolism and of its regulation in view of the recent biological data, like PTH/PTHrP (PTH-related peptide)-evoked cell signaling, the role of FGF 23 (Fibroblast growth factor 23) in hypophosphatemia and the regulation of vitamin D metabolism by 1alpha-hydroxylase. Inter-relation of these regulating elements is present in several genetic diseases and in the Mc Cune Albright syndrome. Relationships between metabolic and endocrine factors are analyzed considering their impact on PTH secretion and osteogenesis.

Synthesis and antioxidant efficiency of a new amphiphilic spin-trap derived from PBN and lipoic acid

The synthesis of a new amphiphilic antioxidant called PBNLP and derived from both alpha-phenyl-N-tert-butyl nitrone (PBN) and lipoic acid was described. Grafting a lactobionamide moiety onto the aromatic group of the PBN provided the water solubility of this compound. In vitro preliminary biological evaluations of its antioxidant capacity were performed using the KRL biological test based on free radical-induced hemolysis. The PBNLP induces a protection of erythrocytes against exogenous free radicals higher than that measured with lipoic acid or PBN alone or with lipoic acid or PBN derivatives in admixtures.

Exhaled NH3 and excreted Nh4+ in children in unpolluted or urban environments

Exhaled ammonia (NH3ex) was measured by chemiluminescence in a group of healthy children (n = 20) and in two groups of asthmatic children, one (Group 1) residing in a National Park in the mountains (n = 68) and other (Group 2) in an urban area (n = 52). We also determined urinary ammonia, nitrates, urea, sodium and potassium normalized to osmolarity. Unlike exhaled nitric oxide (NOex), NH3ex was not specific to asthma as the children in Group 2 and the controls exhaled more ammonia that did the children in Group 1 (14.3 +/- 10.2 and 14.8 +/- 10.3 vs. 5.6 +/- 4.7 ppb; P < .001, respectively). In the urban environment, all children, including the healthy controls, excreted more ammonia (P < .001) and potassium (P < .001) but less urea (P < .02) than did the children residing in the National Park. These manifestations of moderate metabolic acidosis would favor excretion of ammonia at the expense of urea. In the children residing in the National Park, positive correlations were observed between NH3ex and urinary ammonia, and nitrates, age and morphological parameters. The relationship with the morphological parameters is a reflection of the normal physiological formation of NH3ex. In the children residing in the urban area, the other endogenous source of NH3ex was attributed to a slight disturbance in acid-base balance. In conclusion, the measurement of NH3ex appeared of limited interest, although the higher urinary urea/NH4+ ratio in Group 1 (P < .0001), especially in the treated children, appeared to be linked to the lack of atmospheric pollutants in the National Park. Further experimentation is in progress to confirm these findings.

New 3'-azido-3'-deoxythymidin-5'-yl O-(4-hydroxyalkyl or -alkenyl or -alkylepoxide) carbonate prodrugs: synthesis and anti-HIV evaluation

New 5'-O-carbonate prodrugs of zidovudine (AZT) have been synthesized in order to enhance its uptake by HIV-1 infected cells, to improve its anti-HIV potency, and to optimize the intramolecular cyclic rearrangement process related to the 5'-O-(4-hydroxybutyl) carbonate moiety. Evidence of this prodrug rearrangement was confirmed by comparison of the serum half-lives of the 3'-azido-3'-deoxythymidin-5'-yl O-(4-hydroxyalkyl or -alkenyl or -alkylepoxide) carbonate prodrugs with our thermodynamic predictions. Interestingly, these 5'-O-carbonate prodrug series show increased anti-HIV potencies in conjunction with, or without, reduced cytotoxicity as compared to AZT that lead to a gain in selectivity indexes. The cytotoxicity of AZT could be reduced with these 5'-O-carbonate prodrug series by delaying the 5'-O-glucuronidation of AZT, which is one of the major limitations of AZT.

New 3'-azido-3'-deoxythymidin-5'-yl O-(omega-hydroxyalkyl) carbonate prodrugs: synthesis and anti-HIV evaluation

Prodrugs of zidovudine (AZT) have been synthesized in an effort to enhance its uptake by HIV-1 infected cells and its anti-HIV activity. The 5'-OH function of AZT was functionalized with various enzymatically labile alkyl groups using specific procedures. The prodrug moieties included 5'-O-carbonate, 5'-O-carbamate, and 5'-O-ester. Analogues of the 3'-azido-3'-deoxythymidin-5'-yl O-(omega-hydroxyalkyl) carbonate series were particularly interesting since they were rearranged through an intramolecular cyclic process during their enzymatic hydrolysis. Evidence of this prodrug rearrangement was confirmed by comparison of the serum half-lives of 5'-O-carbonate prodrugs with their corresponding 5'-O-ester- and 5'-O-carbamate-AZT prodrugs. Interestingly, the anti-HIV-1 activities (EC(50)) of 3'-azido-3'-deoxythymidin-5'-yl O-(4-hydroxybutyl) carbonate 10 in acutely infected MT-4 cells and in peripheral blood mononuclear cells (PBMCs) were 0.5 nM and 0.78 nM, respectively. Compound 10 was 30 to 50 times more potent than its parent drug AZT. Our results suggest that the specific intramolecular rearrangement associated with the 3'-azido-3'-deoxythymidin-5'-yl O-(omega-hydroxyalkyl) carbonate prodrugs could explain the remarkable anti-HIV-1 activity of this series of AZT prodrugs. Prodrug 10 may therefore have better clinical potential than AZT for the treatment of AIDS.

Relationship between conformation of polysaccharides -in the dilute regime and their interaction with a phospholipid bilayer

Interactions between polysaccharides and phospholipid bilayers have already been demonstrated in the literature but little is known about the influence of macromolecule conformations related to the solvent characteristics (pH, ions, ionic strength). In this study we have investigated the conformation of iono- and thermo-sensitive polysaccharides, iota- and kappa-carrageenans, and their interaction with a dimyristoylphosphatidylcholine (DMPC) model bilayer. The study was performed in two different media (NaCl 150 mmol/L, pH 6.5, and NaCl 300 mmol/L, pH 6.5). In the first part, the iota- and kappa-carrageenan samples have been characterized by size exclusion chromatography (SEC) coupled with a multi-angle laser light-scattering detector (MALLS). The SEC-MALLS results clearly show polysaccharide chain association at high ionic strength. In the second part, the polysaccharide-membrane interaction has been studied, using fluorescent probes embedded in the membrane. The thermotropic properties of the membrane were investigated by fluorescence depolarization of 1-(4-trimethylammonium-phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). The membrane surface accessibility was evaluated by fluorescence quenching of 2-(9-anthroyloxy) stearic acid (2-AS). Whatever the ionic strength tested, the polysaccharide presence notably enhances the membrane fluidity below the T(m). This sign of an interaction in the polar level of the membrane is more marked at low NaCl concentration. In contrast, the liposomes bilayer accessibility is drastically lowered when increasing the ionic strength. This is induced by macromolecular chain adsorption on the liposome surface, enhanced by the polysaccharide chain association. An ionic strength enhancement induces a conformational modification of the polysaccharide chains which modifies their ability to interact with the bilayer.

Identification of pancreatic type I secreted phospholipase A2 in human epidermis and its determination by tape stripping

Phospholipases A2 (PLA2) catalyse the release of fatty acids from the sn-2 position of phospholipids and have been suggested to play a key part in permeability barrier homeostasis. Using a sensitive and versatile fluorometric method, significant PLA2 activity has been detected in both human skin homogenates and tape strippings of stratum corneum. Based on various properties (resistance to heat and sulphuric acid treatment, neutral optimal pH, absolute requirement for millimolar calcium concentrations, inhibition by dithiothreitol and p-bromophenacyl bromide, and resistance to a trifluoromethyl ketone derivative of arachidonic acid, AACOCF3, a specific inhibitor of cytosolic PLA2), this enzyme was characterized as a secretory PLA2 (sPLA2). Immunohistochemistry revealed strong labelling of type I pancreatic sPLA2 at the stratum corneum-stratum granulosum junction, type II sPLA2 being undetectable. An increase in PLA2 activity in tape-stripped material from the deepest level of the stratum corneum was correlated with partial morphological disappearance of type I sPLA2 immunolabelling. Our data thus provide the first convincing evidence that pancreatic sPLA2 is significantly expressed in human epidermis, where it might participate in the accumulation of free fatty acids contributing to the permeability barrier. In addition, our method for determining PLA2 activity in easily available tape strippings should allow further clinical studies aimed to explore possible PLA2 abnormalities in various dermatoses.

Polymorphism of the 5' untranslated region of NHE1 gene associated with type-I diabetes

The ubiquitous form of the sodium-hydrogen exchanger, NHE1, is devoted to the regulation of intracellular pH and cell volume. In addition, NHE1 activity is stimulated by growth factors and increased NHE rates are found in both circulating and immortalized cells during diabetes or diabetic nephropathy. In this context, we searched for polymorphisms of the 5'-flanking regulatory region of NHE1 gene in subjects with type-I diabetes. We identified a C/T transition 696 bases upstream the translation initiation start site which disrupts a repeated palindromic GC sequence. The TT genotype was significantly more frequent in type-1 diabetics and may have functional importance. Genetic linkage between NHE1 and diabetes has been previously described in NOD mice strains with consequences on NHE rates. Hence, the polymorphism described hereby may act as a predisposition factor to type-I diabetes or to diabetic complications, and may be useful to investigate the genetic involvement of NHE1 in human pathophysiology.

[Gammopathies of indeterminant significance and osteoporosis: association or coincidence?]

OBJECTIVES

Osteoporosis is common in subjects over 70 years of age. Likewise, the incidence of monogammapathies of undetermined signification (MGUS) increases with age. We conducted this study to determine whether the biological and histomorphometric characteristics of osteoporosis in patients with MGUS are different from those in primary osteoporosis and to ascertain whether any cause and effect relationships could exist between MGUS and osteoporosis, excluding signs of active myeloma.

PATIENTS AND METHODS

Serum and urinary phosphorus and calcium, histomorphometric measurements, hormone levels and serum cytokines (IL1, IL6 and TNF alpha) were determined in 7 patients (mean age 71.8 years, 2 men and 5 women) with MGUS associated with osteoporosis with vertebral fractures (OP) and compared with those in 7 osteoporosis patients without MGUS matched for age, sex, and osteoporosis severity and 7 other age and sex matched patients with MGUS without OS. The MGUS + PS patients were followed for 9 years (4.5 to 20) so slowly progressive myeloma could be excluded.

RESULTS

Cytokine levels were the same in the three groups of patients but MGUS + OP patients had higher urinary calcium levels (ca/cr = 0.21 +/- 0.08 vs 0.12 +/- 0.1 (OP) and 0.13 (MGUS); p = 0.04), decreased osteocalcin levels (7 +/- 4.6 ng/ml vs. 12 +/- 4 (OP) and 11.5 +/- 5 (MGUS); p = 0.01) and increased surface resorption (8 +/- 1.4 vs. 3.6 +/- 1.2 (OP) and 5.5 +/- 1.7 (MGUS); p = 0.05).

DISCUSSION

It has been demonstrated that MGUS in patients with increased resorption and lower osteocalcin levels frequently progresses to active myeloma. The question is raised as to whether, in certain cases of MGUS, in situ stimulation of bone cells by monoclonal plasma cells could exist without ongoing transformation to active myeloma.

Do calcium-channel blockers and glucocorticoids impair no production in ischaemic heart disease patients?

Calcium channel blockers, as glucocorticoids, may impair generation of NO in vivo, because of urinary nitrates deficit in spite of nitrated derivatives treatment in ischaemic heart disease patients.

Lysophosphatidic acid as a phospholipid mediator: pathways of synthesis

From very recent studies, including molecular cloning of cDNA coding for membrane receptors, lysophosphatidic acid (LPA) reached the status of a novel phospholipid mediator with various biological activities. Another strong argument supporting this view was the discovery that LPA is secreted from activated platelets, resulting in its appearance in serum upon blood coagulation. The metabolic pathways as well as the enzymes responsible for LPA production are poorly characterized. However, a survey of literature data indicates some interesting issues which might be used as the basis for further molecular characterization of phospholipases A able to degrade phosphatidic acid.

Dual effect of lysophosphatidic acid on proliferation of glomerular mesangial cells

Among the variety of factors able to contribute to mesangial hypertrophy by altering mesangial cell growth, lysophosphatidic acid (LPA) is the focus of increasing attention. It is produced in plasma following platelet activation, as well as by mesangial cells stimulated by secretory phospholipase A2. As mitogenic/antimitogenic properties of LPA are already described in a variety of cells, knowledge of its specific actions on mesangial cells is of potential interest regarding the pathophysiology of glomerulus damage in situ. We tested the effect of LPA on cultured rat mesangial cell growth. At 10 to 20 microM, LPA stimulated thymidine incorporation as well as phosphorylation of mitogen-activated protein kinases (MAP-kinases) p42-p44 in dose- and time-dependent manner, which demonstrated a positive effect on cell proliferation. However, higher concentrations of LPA (100 microM) were unable to stimulate thymidine incorporation and partly inhibited the proliferative effect as well as p42-p44 phosphorylation evoked by serum. Finally, whereas lysophosphatidylcholine (10 to 20 microM) was lytic for mesangial cells, no cell lysis could be detected at the highest concentrations of LPA. Taken together, these results suggest that LPA exerts a dual effect on mesangial cell proliferation, which could be due to activation of distinct specific signaling pathways, in dose-dependent fashion. Specific actions of LPA able to modify mesangial cell proliferation in a positive or negative manner are also likely to influence the pathophysiological processes involved in the progression of glomerulosclerosis in the kidney.

Increased content of annexin II (p36) and p11 in human placenta brush-border membrane vesicles during syncytiotrophoblast maturation and differentiation

Annexins are a group of proteins abundant in placental membranes where they may play diverse functional roles. Annexins are expressed in high levels in mature placenta but little is known about their presence at very early stages of gestation and later. We used the model of brush-border membrane vesicles (BBMV) at different stages of gestation to assess precise localization of some of these proteins in syncytiotrophoblast apical membrane and to determine their appearance along the maturation process of placenta. Here we describe annexins type I, II, IV, V and VI which are present all along gestation in BBMV. Annexin II (p36) is present with the S100 like calcium-binding protein p11 in BBMV, where they can constitute heterotetrameric forms of annexin II linked to cytoskeleton structures. No variation of annexins I, IV and VI content was observed in BBMV along pregnancy. Annexin V undergoes significant decrease after 12th week, which could be related to local anticoagulant activity. Levels of annexin II and p11 increased progressively during gestation suggesting that heterotetrameric forms of annexin II play a role in the differentiation process of placenta and in function of the mature microvilli.

Growth hormone induces tyrosine phosphorylation of annexin I in rat osteosarcoma cells

GH induces phosphorylation of a number of cellular proteins, of which several have now been identified, such as mitogen-activated protein kinase, insulin receptor substrate-1, and members of the JAK kinase and STAT families of proteins. However, other phosphorylated proteins remain unidentified. Growth factors and cytokines, including epidermal growth factor, insulin, pp60v-scr, and angiotensin II, induce a rapid phosphorylation of annexin I, a 35-kDa member of the annexin family of Ca2+ and phospholipid-binding proteins. The osteoblast-like rat osteosarcoma cell-line UMR-106.01, in which GH acts as a mitogen via a high affinity GH receptor, was used as a model for GH-induced protein phosphorylation. It is demonstrated by immunoblotting and immunoprecipitation techniques that GH induces the phosphorylation of annexin I on tyrosine residues. This phosphorylation is dose and time dependent. Induction of annexin I phosphorylation is delayed compared with that of JAK2. These results identify annexin I as a protein that becomes tyrosine phosphorylated under the influence of GH and show that phosphorylation of annexin I is a general phenomenon that follows activation of a cell by hormones or cytokines.

Growth hormone binds to a single high affinity receptor site on mouse osteoblasts: modulation by retinoic acid and cell differentiation

Growth hormone (GH) exerts direct differentiative and proliferative effects on osteoblasts. We studied 125I-labeled human (h) GH binding to primary mouse osteoblasts derived from collagenase-treated 18-day fetal mouse calvaria. Scatchard analysis of the data revealed a single class of high affinity GH receptors (apparent Ka = 5.74 x 10(9) M-1) with 2200 sites per cell. Affinity crosslinking and SDS-PAGE electrophoresis showed two bands with apparent molecular masses of 120 and 70 kDa. Mouse osteoblasts express GH receptor mRNA with gene transcripts of 4.2 and 1.2 kb, at levels which reach approximately 1/6 of those in mouse liver and 1/3 of those in mouse muscle. Two populations of undifferentiated and diffentiated osteoblasts, obtained by sequential collagenase digestion of mouse calvaria, were used to study the relationship between osteoblastic phenotype and GH receptor expression. Although the affinity of the receptors in undifferentiated and differentiated cells was the same, the capacity was significantly higher (1.45 +/- 1.0% vs 2.39 +/- 0.9%, P = 0.03) in differentiated cells. This stresses the specific importance of the osteoblast as a target cell for GH. The differentiating potential of the vitamin A derivative retinoic acid was subsequently used experimentally to induce differentiation in the cells. Retinoic acid increased 125I-hGH binding to preosteoblasts (153%, P = 0.02). Together, these data demonstrate the presence of a high affinity GH receptor in mouse osteoblasts which is related to differentiation.

Insulin-like growth factor binding proteins-2 and -3 stimulate growth hormone receptor binding and mitogenesis in rat osteosarcoma cells

GH exerts its biological actions on osteoblasts through a specific high affinity receptor expressed on these cells. GH receptor binding is positively modulated by a number of factors, including retinoic acid and dexamethasone, whereas fetal calf serum strongly decreases the binding. To identify responsible factors in serum, components of serum, the insulin-like growth factors (IGFs)-I and -II, and IGF binding proteins (IGFBPs)-2 and -3 were tested for a possible negative modulatory role. IGF-I and -II decreased [125I]hGH binding at an optimal concentration of 30 ng/ml for IGF-I and 100 ng/ml IGF-II, reducing the binding to 51% and 55%, respectively, of control values. A stimulation of [125I]hGH binding was observed with IGFBP-2 as well as IGFBP-3, inducing an increase to 148% and 151% of control binding at an optimal concentration of 3000 ng/ml for both peptides. The effects of all peptides were dependent on the incubation time, being significantly increased after 8 h of incubation and reaching the full effect thereafter. The effects were declined at 24 h compared with 16 h for IGFBP-2 and -3 but not for IGF-I and -II. Coincubation of the cells with IGF-I and -II and IGFBP-2 and -3 neutralized the effects of the factors alone. In conclusion, these results show that IGF-I and -II on the one hand and IGFBP-2 and -3 on the other hand exert opposite actions on [125I]hGH binding, IGFBP-2 and -3 exerting probably an IGF-independent effect. Further, IGF-I and -II decreased GH receptor messenger RNA (mRNA) levels, as quantified by a solution hybridization ribonuclease protection assay, from 8.65 +/- 1.78 attomoles (amol)/microgram DNA (control) to 2.4 +/- 0.68 and 2.16 +/- 0.92 amol/microgram DNA, respectively. IGFBP-2 increased GH receptor mRNA levels from 5.26 +/- 1.17 (control) to 13.19 +/- 3.48. Incubation with IGFBP-3 did not result in stimulation of GH receptor mRNA levels (8.59 +/- 2.91 amol/microgram DNA). This shows that the mechanism of regulation of the GH receptor is, except for IGFBP-3, at least in part on the mRNA level. Lastly, IGFBP-2 and IGFBP-3 are mitogenic for UMR-106.01 rat osteosarcoma cells, inducing an increase in cell number to 125% and 142% of control cell counts after 48 h of incubation with 1000 ng/ml IGFBP-2 and -3, whereas IGF-I, IGF-II and Long R3 IGF-I did not stimulate proliferation. IGFBP-2 and -3 potentiate hGH induced mitogenesis at low hGH concentrations of both factors, whereas at higher concentrations no such effect is observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Dexamethasone increases and serum decreases growth hormone receptor binding to UMR-106.01 rat osteosarcoma cells

Dexamethasone (DEX) is known to exert major effects on functions of osteoblast-like cells. We investigated its action on the regulation of GH receptors in the osteoblast-like osteosarcoma cells UMR-106.01. DEX stimulated [125I]human GH (hGH) binding to UMR-106.01 cells. This effect was dose dependent and significant in a concentration range of 10(-8)-10(-6) M. The maximum effect was an increase of 42 +/- 1.4% (n = 3; mean +/- SE) above control, P < 0.01, at 10(-7) M DEX. Time dependence of this stimulation was observed, with a peak between the 12th and the 16th h of incubation, an effect being still detectable at 48 h. Cycloheximide decreased [125I]hGH binding and completely abolished the stimulating effect of DEX, suggesting that modulation of [125I]hGH binding by DEX is fully dependent on protein synthesis. Addition of fetal calf serum (FCS) resulted in a dose-dependent decrease of [125I]hGH binding to 24 +/- 2% of control (n = 3; mean +/- SE), P < 0.001, without interfering with the stimulatory effect of DEX, the ratio of DEX vs. control being higher with increasing FCS doses. Taken together, these results suggest the existence of different pathways for the regulation of GH receptor binding to UMR-106.01 cells, including a stimulatory one at the pretranslational level for DEX and an inhibitory one for (growth) factors present in FCS.

Intraabdominal serous fluid collections after appendectomy: a normal sonographic finding

OBJECTIVE

The significance of sonographic findings 1 week or less after appendectomy is difficult to evaluate without knowing the inconsequential abnormalities that may occur in these patients. Accordingly, we performed postoperative sonography on patients who had a normal course after appendectomy to determine the findings that can be considered normal within 1 week after surgery.

SUBJECTS AND METHODS

Forty-four patients who had an appendectomy for acute appendicitis and who had normal findings at clinical follow-up 5 days and 6 months later were included in the study. In all patients, sonograms were obtained on the fifth postoperative day and interpreted by a radiologist who did not know the surgical findings.

RESULTS

Ten fluid collections (23%) were found in the pericecal area, ranging in size from 10 x 10 mm to 40 x 20 mm. The collections were hypoechoic or anechoic, crescent-shaped, and immobile. Fluid collections were more common in cases of suppurative appendixes (6/20, 30%) than in cases of inflamed appendixes (4/19, 21%) and in retrocecal appendixes (3/9, 33%) than in normally located appendixes (7/34, 21%). However, the differences were not statistically significant (p > .05).

CONCLUSION

Inconsequential fluid collections are detected with considerable frequency on postoperative sonograms 5 days after an appendectomy. Consequently, not every fluid collection should be considered an abscess.

Sustained effect of angiotensin II on tyrosine phosphorylation of annexin I in glomerular mesangial cells

By means of selective extraction in a Ca(2+)-chelating medium and immunoblotting, four annexins (I, II, V, and VI) were identified in both isolated rat renal glomeruli and rat glomerular mesangial cells. Upon 32P labeling of these cells in culture, annexin I was immunoprecipitated using a specific polyclonal antibody and was found to incorporate radioactivity in a constitutive manner. However, as with epidermal growth factor (200 ng/ml), addition of angiotensin II (10(-7) M), arginine-vasopressin (10(-7) M), or endothelin I (10(-7) M) resulted in a 2-3-fold stimulation of annexin I phosphorylation. The basal phosphorylation as well as the stimulating effect of angiotensin II were also detected by immunoblotting annexin extracts using an antiphosphotyrosine antibody. In addition, among various phosphotyrosyl proteins isolated from EGTA extracts by adsorption onto an anti-phosphotyrosine antibody, annexin I was specifically recognized by Western blotting using a monoclonal anti-annexin I antibody, and displayed the same increase upon cell stimulation with angiotensin II. Moreover, thin layer chromatographic analysis of phosphoamino acids present in immunoprecipitated [32P]annexin I showed an exclusive labeling of phosphotyrosine residue(s). Finally, the effect of angiotensin II was detectable after 10 min, maximal at 6 h, and present until 12 h of incubation. Using 12-h stimulation, tyrosine phosphorylation of annexin I displayed a maximum at 10(-7) to 10(-6) M angiotensin II. These data report for the first time the stimulation of annexin I tyrosine phosphorylation by biologically active peptides acting via receptors belonging to the superfamily of seven hydrophobic domain, G-protein-linked receptors, which lack an intrinsic protein tyrosine kinase. This suggests a possible role of annexin I in the mitogenic effect of angiotensin II, arginine-vasopressin, and endothelin I, which was previously observed on rat glomerular mesangial cells as well as on other cells.

[Activity of platelet sodium-proton exchanger, microalbuminuria and insulin-dependent diabetes]

The plasma membrane Na+/H+ exchanger is a ubiquitous system which plays a role in the regulation of intracellular pH and the control of cell growth. In order to assess the potential role of this system in the pathogenesis of diabetic nephropathy, we investigate 42 normotensive insulin-dependent diabetic patients with or without microalbuminuria. We tested the platelet Na+/H+ exchange as the rate of amiloride sensitive and sodium dependent volume gain of cells suspended in sodium propionate. Urinary albumin excretion (UAE) was assayed by radioimmunoassay on a 24 h sample; the glomerular filtration rate (GFR) and the renal plasma flow were determined by 99 m Tc-DTPA and 1231 l-hippuran respectively. Thirty patients (group 1) had EUA > 30 mg/24 h (m +/- sd: 11 +/- 7 mg/24 h), 12 patients (group 2) had microalbuminuria (62 +/- 30 Mg/24 h, range from 35 to 136 mg/24 h). The platelet Na+/H+ exchange rate was significantly increased in patients of group 2: 0.34 +/- 0.01 versus 0.26 +/- 0.06 s-1 x 10(-2) (p < 0.005). There was no significant difference between these two groups regarding blood pressure (116 +/- 14/71 +/- 7 versus 119 +/- 12/73 +/- 5 mmHg), age, diabetes duration, glycated hemoglobin or fructosamine levels. On the whole population, we found a significant positive correlation between the platelet Na+/H+ exchange rate and the UAE (r = 0.57, p < 0.001) and with the glomerular filtration fraction (r = 0.43, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Increased platelet sodium-proton exchange rates in insulin-dependent (type 1) diabetic patients with nephropathy and hypertension

In order to assess the potential role of the plasma membrane sodium-proton (Na+/H+) exchanger in the pathogenesis of diabetic nephropathy, we investigated 32 insulin dependent (type 1) diabetic patients and 21 control subjects. We tested the Na+/H+ exchange as the rate of amiloride sensitive and sodium dependent volume gain of platelets suspended in sodium propionate. Patients with diabetic nephropathy had significantly increased rates of Na+/H+ exchange (0.31 +/- 0.06 s-1 x 10(-2)) when compared to those without nephropathy (0.24 +/- 0.07, p less than 0.05) or to a control group (0.23 +/- 05, p less than 0.05). Nine patients who were classified as hypertensive had a highly significant increase in the Na+/H+ exchange rates when compared to 23 non-hypertensive diabetic patients: 0.33 +/- 0.04 versus 0.24 +/- 0.06 (p less than 0.001). There was no significant correlation between the Na+/H+ exchange rates and age, diabetes duration, glycated hemoglobin or fructosamine levels on the day of the test. In summary, the data presented here demonstrate an increase in the Na+/H+ exchange rate in insulin-dependent diabetic patients with nephropathy and hypertension.

Effect of pinaverium bromide on jejunal motility and colonic transit time in healthy humans

Pinaverium bromide is a specific calcium channel blocker used in the treatment of irritable bowel syndrome (IBS) for its spasmolytic activity. The aim of the present study was to evaluate the effect of orally administered pinaverium bromide on jejunal motility and total and segmental colonic transit time in control subjects. Gastrointestinal studies were performed in 10 healthy volunteers (30 +/- 3 years), before and after a treatment phase of 14 days (150 mg/d). Jejunal motility was measured by prolonged manometry (14 h) and colonic transit time by a multiple ingestion, single marker technique. No significant modification of phase III of the migrating motor complexes was demonstrated. On the contrary, a significant (p < 0.01) but weak decrease of the frequency of contraction was found. Unlike previous studies, no decrease of total or segmental colonic transit time was demonstrated.

[Results of the evaluation of platelet sodium-proton exchange in the young hypertensive subject]

In order to assess the relationships between increased cellular sodium-proton (Na+/H+) exchange and cardiovascular abnormalities in essential hypertension (EH), 21 young subjects as part of an ongoing longitudinal study were tested for the platelets Na+/H+ exchange using the amiloride sensitive sodium dependent component of platelet volume change under cytoplasmic acidification induced by a sodium propionate medium; cell volumes were determined by electronic cell sizing (Livne et al., Lancet 1987; i: 533-6). 24 normal subjects with normotension and without familial history of hypertension were taken as controls. Data of ambulatory blood pressure recording (ABPR) defined 2 groups according to the presence of normotension (group I, n = 10), or of hypertension (group II, n = 11): established (n = 2) or borderline (n = 9) hypertension. Hypertensive subjects (group II) had increased values of Na+/H+ exchange (k coefficient, mean (SEM): 0.287 (0.07) vs 0.228 (0.05) in control group (p less than 0.01). Na+/H+ rates were significantly related to ABPR data (r = 0.46, p less than 0.02 with diastolic charge during ABPR), but not to left ventricular mass index in g/m2 by echocardiography. Increased rates of platelets Na+/H+ exchange which were related to diastolic blood pressure levels by ABPR, and perhaps to the level of peripheric vascular resistances, may play a significant role in the development of EH in the early stages.

[Maternal connective tissue disease associated with congenital AV block]

We report 3 patients with congenital A-V block whose mothers had anti-Ro or anti-La antibodies. One of them had systemic lupus with serum anti-Ro antibodies; the other had anti-Ro antibodies and no clinical manifestations; the third had an undifferentiated connective tissue disorder with anti-La antibodies in the serum. The epidemiology of this association is discussed as well as some therapeutic options.

Lipocortin-like anti-phospholipase A2 activity of endonexin

Endonexin (protein II, 32.5 kDa) has been purified to homogeneity from bovine liver in the following steps: selective extraction by EGTA from membranes precipitated with Triton X-100/calcium; chromatography on DEAF-TSK 545 at pH 7.0, endonexin being eluted at 0.1 M NaCl; affinity chromatography on polyacrylamide-immobilized phosphatidylserine; gel filtration on TSK 3000. The amino acid composition was essentially similar to that previously reported. Using [3H]oleic acid-labelled Escherichia coli membranes as substrate, endonexin inhibited phospholipase A2 from pig pancreas. Maximal inhibition was 55 and 70%, whereas 50% inhibition occurred at 480 and 120 nM endonexin and lipocortin II, respectively. These data could be related to common features shared by both lipocortins/calpactins and endonexin, i.e. the presence of a consensus sequence and the ability to bind to anionic phospholipids in a calcium-dependent manner.