The ascidian pigmented sensory organs: structures and developmental programs

The recent advances on ascidian pigment sensory organ development and function represent a fascinating platform to get insight on the basic programs of chordate eye formation. This review aims to summarize current knowledge, at the structural and molecular levels, on the two main building blocks of ascidian light sensory organ, i.e. pigment cells and photoreceptor cells. The unique features of these structures (e.g., simplicity and well characterized cell lineage) are indeed making it possible to dissect the developmental programs at single cell resolution and will soon provide a panel of molecular tools to be exploited for a deep developmental and comparative-evolutionary analysis.

Efficacy of three different antithrombotic regimens on pregnancy outcome in pregnant women affected by recurrent pregnancy loss

INTRODUCTION

Recurrent pregnancy loss (RPL) is a common health problem affecting 1-5% of women at reproductive age.

AIM OF THE STUDY

Evaluation of three different antithrombotic treatments in women with antecedent of RPL, comparing the results in negative and positive to thrombophilic screening pregnant women.

MATERIALS AND METHODS

We recruited 361 women with an antecedent of two or more pregnancy losses. From this group, 167 women became pregnant and considered for the study. The evaluated pregnant women were divided as negative/positive to thrombofilic screening: (a) 80 (48%) with negative thrombophilic screening, (b) 87 (52%) positive to thrombophilic screening. Pregnant women included in the study and considered negative or positive for thrombophilic screening, were randomized into three different therapy groups: (a) group 1: Acetil salicylic acid (ASA) 100 mg daily until third month of pregnancy, (b) group 2: low molecular-weight heparin (LMWH) - enoxaparine 40 mg daily until third month of pregnancy, (c) group 3: ASA 100 mg plus LMWH 40 mg daily until third month of pregnancy.

RESULTS

In 80 negative to thrombophilic screening pregnant women, the comparison of efficacy of the three treatments, shows that all three treatment regimens were significantly effective comparing live births against fetal losses. In 87 positive to thrombophilic screening pregnant women, the comparison of efficacy for the three regimens, shows that the therapy with LMWH or LMWH plus ASA are significantly protective against fetal losses with respect to ASA, which showed a high number of fetal losses (11 live births, 18 fetal losses).

COMMENT

We suggest that thromboprophylaxis is indicated in women with RPL independently from positiveness to thrombophilic markers.

[Pregnancy in lupus patients: our experience]

AIM

Systematic lupus erythematosus (SLE) is the most common autoimmune disease associated with pregnancy. The aim of this study was to evaluate management and outcome of pregnancy complicated by SLE.

METHODS

Twenty pregnant women affected by SLE were admitted to Prenatal Diagnosis Centre of University "Sapienza" from January 2007 to July 2009. Pregnancy was monitored from diagnosis to delivery by at least a monthly consultation. At each visit general blood laboratory assessment were registered. An ultrasound examination was performed to evaluate fetal growth. From 26 weeks of gestation an estimation of fetal weight was calculated according to the standard of Lubchenco. At birth newborns weight was registered.

RESULTS

Patient mean age was 32.9 years. There were 18 live births (90%), and 2 spontaneous abortions; 50% of pregnancy ended with a preterm delivery. 20% of the patient had signs of disease activity during pregnancy. Fifteen percent of women presented gestational hypertension. An high rate of small for gestational age was registered and 2 cases of intrauterine growth retardation (IUGR). Ultrasound evaluation at 28-30 weeks of gestation showed a normal weight (≥ 50th percentile) in 83% fetuses. Only 45% of the newborns presented ≥ 50th percentile. The mean weight of the newborns was 2700 grams.

CONCLUSION

Pregnancy outcome could be improved by close obstetrical and ultrasound monitoring in a multidisciplinary setting.

CT colonography with reduced bowel preparation after incomplete colonoscopy in the elderly

We prospectively assessed the feasibility and acceptance of computerized tomographic colonography (CTC) without bowel cathartic preparation in elderly patients after incomplete colonoscopy. A total of 136 patients underwent CTC without cathartic preparation. The time delay between conventional colonoscopy and CTC ranged between 3 and 20 days, depending on the clinical situation. Before CTC, fecal tagging was achieved by adding diatrizoate meglumine and diatrizoate sodium to regular meals. CTCs were interpreted using a primary two-dimensional (2D) approach and 3D images for further characterization. Patients were interviewed before and 2 weeks after CTC to assess preparation acceptance. CTC was feasible and technically successful in all the 136 patients. Fecal tagging was judged as excellent in 113 (83%) patients and sufficient in 23 (17%). Average CT image interpretation time was 14.8 min. Six (4.4%) cases of colorectal cancer and nine (6.6%) large polyps were detected, as well as 23 (11.3%) extracolonic findings of high clinical importance. No major side effect occurred, although 25% patients reported minor side effects, especially diarrhea. Overall, 76/98 patients replied that they would be willing to repeat the test if necessary. CTC without cathartic preparation is a technically feasible and safe procedure to complete a colonic study in the elderly, prompting its use in clinical practice.

Cititf1 and endoderm differentiation in Ciona intestinalis

Studies on the initial formation of the endoderm have lead to the identification, mostly in Xenopus, of numerous genes relevant for the formation of this tissue during early embryogenesis (reviewed by Date, Curr. Biol. 9 (1999) R812-R815 and by Yasuo and Lemaire, Curr. Biol. 9 (1999) 869-879). In ascidians, the most primitive chordates, endoderm differentiation is an autonomous process which is almost complete at 64 cells stage. Cititf1, a gene homologous to mammalian Titf1, is the first specific endodermal marker isolated from the ascidian Ciona intestinalis (Ristatore et al., Development 126 (1999) 5149-5159). Here we study the in vivo role of Cititf1 by using two different approaches: interference and ectopic expression. The results presented here show that interference with Cititf1 function seems to affect gastrulation movements, while ectopic expression of Cititf1 mRNA into the notochord alters differentiation of this tissue probably by recruiting notochord blastomeres to an endodermal fate. These data together with studies, still in progress in our laboratory, on the transcriptional regulation of Cititf1, strongly indicate that Cititf1 plays an important role in the process of endoderm formation in Ciona embryogenesis.

Reduced deformability of erythrocytes as feature of congenital dyserythropoietic anaemia type II (HEMPAS)

In this study we report results regarding erythrocytes deformability in congenital dyserythropoietic anemia type II (HEMPAS) by the use of LORCA (Laser-assisted Optical Rotational Cell Analyzer). The reduced erythrocytes deformability observed in seven case of CDA II is caused by changes in the structure of glycoproteins due to the incomplete glycosylation of erythrocytic and erythroblastic membrane. Erythrocytes deformability (EI) was shown to be inversely related with mean corpuscular volume (MCV) and mean haemoglobin concentration (MCH).

Erythrocytes stored in CPD SAG-mannitol: evaluation of their deformability

The erythrocytes deformability of three blood samples coming from healthy donors has been evaluated by Laser-assisted Optical Rotational Cell Analyzer (LORCA). Blood samples were stored in CPD SAG-mannitol. The study of progressive reduction in the Elongation Index (EI) during the preservation may be used as way of evaluation of erythrocyte vitality in stored blood samples.

Expression and functional analysis of Cititf1, an ascidian NK-2 class gene, suggest its role in endoderm development

In solitary ascidians the fate of endoderm is determined at a very early stage of development and depends on cytoplasmic factors whose nature has not been determined. We have isolated a member of the NK-2 gene family, Cititf1, from the ascidian Ciona intestinalis, showing high sequence homology to mammalian TITF1. The Cititf1 gene was expressed in all endodermal precursors at the pregastrula and gastrula stages, and is thus the first specific regulatory endodermal marker to be isolated from an ascidian. Cititf1 expression was downregulated at the end of gastrulation to reappear at middle tailbud and larval stages in the most anterior and ventral parts of head endoderm, regions which give rise, after metamorphosis, to the adult endostyle, where Cititf1 mRNA was still present. Microinjection of Cititf1 mRNA into fertilized eggs resulted in tadpole larvae with abnormalities in head-trunk development consequent to the formation of excess endoderm, perhaps due to recruitment of notochord precursors to an endodermal fate. These data suggest that Cititf1 plays an important role in normal endoderm differentiation during ascidian embryogenesis.

Assessment of erythrocyte deformability with the laser-assisted optical rotational cell analyzer (LORCA)

The erythrocyte deformability of 28 patients with anemia was evaluated with the laser-assisted optical rotational cell analyzer (LORCA), an image analyzer that converts into numerical form the degree of refraction of a laser beam induced by red cells subjected to a range of torsional stresses. The patients were 10 thalassemics, including three with intermediate forms (1 HbC/beta degree, 1 homozygote beta for Orkin's haplotype VI, 1 beta degree/beta delta Sicilian type) and seven heteroygotes for beta Th; six with hereditary spherocytosis (including 2 with structural alteration of the spectrin beta chain); three with type II congenital dyserythropoietic anemia (HEMPAS), two hemizygotes and one heterozygote for G-6PD deficiency, and six with severe hypochromic hyposideremic anemia. Red cell deformability was reduced in intermediate thalassemia, hereditary spherocytosis and HEMPAS, normal in heterozygous beta thalassemia and G-6PD deficiency, and increased in hypochromic hyposideremic anemia. These results show that erythrocyte deformability can be impaired by an Hb chain imbalance, membrane and cyto skeleton structure anomalies and changes in the red cell area/volume ratio.

The roles of maternal alpha-catenin and plakoglobin in the early Xenopus embryo

Catenins (alpha-, beta- and gamma- or plakoglobin) are cytoplasmic cadherin-associated proteins. Studies on cultured cells have suggested that both alpha-catenin and plakoglobin are important for the adhesive function of cadherins. alpha-catenin binds to both beta-catenin and plakoglobin and may link the cadherin/catenin complex to actin filaments. Separate domains of plakoglobin bind to cadherin and alpha-catenin, suggesting it may act as a bridge between these molecules. However, plakoglobin may have other activities: it is expressed in both desmosomal junctions in association with desmogleins and the cytoplasm in conjunction with APC, and previous work suggests it may act in a dorsal signalling pathway when overexpressed in Xenopus embryos. Here, we have studied the roles of alpha-catenin and plakoglobin directly, by depleting the maternal mRNAs coding for each of them in developing Xenopus embryos. We find that depletion of maternal alpha-catenin causes the loss of intercellular adhesion at the blastula stage, similar to that reported previously for EP cadherin. Depletion of plakoglobin results in a partial loss of adhesion, and a loss of embryonic shape, but does not affect dorsal signalling.

Cloning of ascidian homeobox genes provides evidence for a primordial chordate cluster

In order to isolate genes important in controlling embryonic development in Tunicates, a genomic library from the ascidian Ciona intestinalis was screened with a degenerate oligodeoxyribonucleotide encoding the third helix of Antennapedia-type homeoboxes. Fourteen C. intestinalis homeobox genes, corresponding to several classes of homeodomains, have been identified. Five of the isolated homeoboxes show their highest homology to members of the Vertebrate HOX clusters. mRNAs for two of the isolated homeoboxes are present in unfertilized C. intestinalis eggs.

Isolation and characterization of two genes encoding calitoxins, neurotoxic peptides from Calliactis parasitica (Cnidaria)

Among sea anemone neurotoxins, calitoxin, recently isolated from Calliactis parasitica, is a highly toxic peptide of 46 amino acids (aa), whose sequence differs greatly from that of all sea anemone toxins isolated so far. In this study, two genes (clx-1 and clx-2) coding for two highly homologous calitoxins were isolated and characterized from a C. parasitica genomic library. The clx-1 gene encodes the already known calitoxin sequence, named CLX-I, whereas a single bp substitution in the coding region of clx-2 is responsible for a single Glu6-->Lys replacement in a new peptide named CLX-II. The structural organization of the two genes is very similar: two introns and three exons, whose sequences are highly homologous for clx-1 and clx-2 (95% identity). The open reading frame (ORF) of both clx-1 and clx-2 codes for a precursor peptide of 79 aa, whose N-terminus has the feature of a single peptide, while the C-terminus corresponds to the sequences of mature CLX-I and CLX-II. The finding that a pair of basic aa is located upstream from the sequence of both mature toxins strongly suggests that proteolytic events, at specific cleavage sites, are responsible for the release of neurotoxins from their respective precursor molecules.

Gonadotropin-releasing hormone in elasmobranch (electric ray, Torpedo marmorata) brain and plasma: chromatographic and immunological evidence for chicken GnRH II and novel molecular forms

Gonadotropin-releasing hormone (GnRH) peptides in the brain, testis and plasma of an electric ray (Torpedo marmorata) were investigated by gel filtration chromatography, reverse phase high performance liquid chromatography and radioimmunoassay with region-specific antisera. In the brain, two major forms of GnRH were demonstrated. One form had identical chromatographic and immunological properties to chicken GnRH II, and the second, novel, molecular form had structural features in common with mammalian, chicken II and salmon GnRHs. A minor, early-eluting immunoreactive peak, possibly also a novel GnRH, was also evident. Immunoreactive GnRH was not detected in the testis. In the plasma, a single major early-eluting immunoreactive peak was demonstrated. This peak, identical to the minor peak observed in the brain, is likely to represent a novel form of GnRH which has immunological properties in common with mammalian, chicken II and salmon GnRHs. Immunoreactive GnRH was not detected in the plasma of species from other vertebrate classes, including rabbit, chicken, monitor lizard, clawed toad, frog, cichlid fish and lamprey. The finding of chicken GnRH II in a species of Chondrichthyes adds further support to our hypothesis that this widespread structural variant may represent an early-evolved and conserved form of GnRH. The presence of a GnRH molecular form in the plasma of the electric ray suggests that GnRH may reach target organs (pituitary and gonads) via the general circulation in some species of Chondrichthyes.

[Clinical experience in surgical-orthodontic treatment of patients with anterior skeletal open-bite]

After a short clinical classification of the various open-bite types, the Authors describe from the clinical and cephalometric point of view the main structural alterations responsible for the skeletal open-bite. Then they consider the orthodontic problems in the orthodontic surgical treatment of the skeletal open-bite. Finally they describe the combined orthodontic surgical treatment in two anterior skeletal open-bite clinical cases.

Molecular forms of immunoreactive gonadotropin-releasing hormone in hypothalamus and testis of the frog, Rana esculenta

The hypothalamus and the testis of the frog, Rana esculenta, contain gonadotropin-releasing hormone (Gn-RH)-like peptides which are recognized by an antiserum raised against mammalian Gn-RH. Two molecular forms which coelute with synthetic chicken II and salmon Gn-RH from reverse-phase HPLC were distinguished in the hypothalamus. A single peak coeluting with synthetic chicken II Gn-RH was present in the testis.

[Use of the Frankel functional regulator in Class II, div. 1]

Frankel's Fr is an activator particularly suitable in malocclusions of II/1 Class in the age of growth. Such device can be also utilized in combination with the fixed multibands therapy in such a way as to connect the effects of the morphofunctional modifications, gettable with activator during the growth of the (effects) maxillary-mandibolar set, to orthodontic ones, of the fixed equipment employed in a successive stage for the perfecting of occlusive connection. For this reason the AA. analyze the applications of Frankel's FR in the treatment of the II/1 Classe in the age of growth. The Authors present three clinical cases, the first is resolved through functional therapy with Frankel's FR, while in the second and third cases at first is made use of functional therapy with FR and afterwards is made use of multi-bands therapy according to Edgewise's technique.

[Clinical picture and orthodontic-surgical therapeutic problems in treatment of Class II division 1 dento-skeletal malformations]

In the present study different types of Class II, Division 1 malocclusions have been taken under consideration. First of all, have been analysed the main etiopathogenetic factors which are the causes of an anomalous development of the Maxillo-Facial complex. It has been pointed out the clinical characteristics of these malformations, necessaries for a careful therapeutical program. The Authors, therefore, in the first face describe the principal orthodontic problematics to tackle, in the second face they describe the surgical techniques mostly used to correct the Class II malocclusions; finally it has been pointed out the role of the orthodontic post-operative treatment, to improve the occlusion and the rehabilitation of the neuromuscular system after correcting maxillo facial skeleton alterations. Three cases are presented for this kind of malformation, treated with the various surgical techniques on the ground of the different kinds of clinical variants.

Calitoxin, a neurotoxic peptide from the sea anemone Calliactis parasitica: amino acid sequence and electrophysiological properties

We have isolated a new toxin, calitoxin (CLX), from the sea anemone Calliactis parasitica whose amino acid sequence differs greatly from that of other sea anemone toxins. The polypeptide chain contains 46 amino acid residues, with a molecular mass of 4886 Da and an isoelectric point at pH 5.4. The amino acid sequence determined by Edman degradation of the reduced, S-carboxymethylated polypeptide chain and tryptic and chymotryptic peptides is Ile-Glu-Cys-Lys-Cys-Glu-Gly-Asp-Ala-Pro-Asp-Leu-Ser-His-Met-Thr-Gly-Thr- Val-Tyr - Phe-Ser-Cys-Lys-Gly-Gly-Asp-Gly-Ser-Trp-Ser-Lys-Cys-Asn-Thr-Tyr-Thr-Ala- Val-Ala - Asp-Cys-Cys-His-Glu-Ala. No cysteine residues were present in the peptide. Similarly to other sea anemone toxins, calitoxin interacts, in crustacean nerve muscle preparations, with axonal and not with muscle membranes, inducing a massive release of neurotransmitter that causes a strong muscle contraction. The low homology of CLX with RP II and ATX II toxins has implications regarding the role played by particular amino acid residues.

[Tooth extraction in surgical orthodontic treatment of malformations of the facial mass]

In the present article the Authors take under consideration the most important role of the presurgical orthodontic treatment from the point of view of the orthodontic techniques which aim to improve the occlusion. The authors, therefore describe the different faces, and they focalize the fact that the therapy may frequently require extractions to resolve serious crowdings of the teeth. They take also care of the maxillo facial skeleton alterations, to decide on extracting and about the ratio between the space available and required in the different cases.

Isolation and partial characterization of rhizolysin, a high molecular weight protein with hemolytic activity, from the jellyfish Rhizostoma pulmo

A new cytolysin has been isolated from the nematocysts of the jellyfish, Rhizostoma pulmo, and named rhizolysin. The hemolysin has a mol. wt of approximately 260,000, a sedimentation coefficient of 10.3 S and is rod-shaped with a calculated axial ratio of about 1:5. It appears to be composed of three subunits with a pI value near 7.8. Rhizolysin shows no phospholipase A activity, nor an induction period for its hemolytic activity and is completely inhibited by sucrose. The optimum pH was 6.75. The mu value calculated from the Arrhenius plot is 5940 cal/mole. Rhizolysin was inhibited by cholesterol and less by sphingomyelin.

Endogenous opioids in marine invertebrates

A study of the presence of opioids in invertebrates was carried out on 11 species of marine organisms, ranging from sponges to tunicates. Delipidized acid-acetone extracts from whole organisms or dissected organs were assayed by receptor binding assays and radioimmuno assays. The extracts from all species tested were found to contain substances capable of competing in both assays with opioid peptides.