Search results for "Tunic"

Antimicrobial peptides in the tunic of Ciona intestinalis (Tunicata)

2013

«Correlation between granulocytes and tunic cuticle of Ciona intestinalis (Tunicata, Ascidiacea) as evaluated by microscopy»

2012

The tunic is a peculiar integumentary tissue covering the epidermis of ascidians and other tunicates. It is an extracellular matrix whose outermost surface is revealed to be a continuos layer called tunic cuticle, composed of electron dense fibrous materials. Mechanisms occurring during the growth of the animal after metamorphosis, must assure the maintenance of the thin tunic cuticle density and integrity as it represents the primary body surface barrier preventing the mechanical and microbial assaults. Investigations by optical and electron microscopy on tunic samples from young Ciona intestinalis, allowed us to study morphological relationship between the tunic cuticle architecture and g…

Cytotoxic activity of Ciona intestinalis (Tunicata) hemocytes: Properties of the in vitro reaction against erythrocyte targets

1993

Hemocytes (effectors) of Ciona intestinalis showed a natural cytotoxic capacity (HCA) when assayed in vitro against erythrocytes (targets). Cytotoxic cells lysed, to a variable extent, rabbit (RE), human (A, B, O), guinea pig, and sheep (SE) erythrocytes. Hemocyte cytotoxic activity (HCA) assayed against SE is a calcium-dependent reaction, occurs rapidly (15-30 min), at 25-37 degrees C over a wide range of pH (5.4-8.0). Assays were carried out using: 1) the medium in which hemocytes were maintained, 2) the soluble portion of hemocyte lysates, and 3) debris prepared from hemocyte lysates. Results suggest that HCA is a cell-mediated process that requires effector-target cell contacts. Anti-SE…

A novel tunicate (Botryllus schlosseri) putative C-type lectin features an immunoglobulin domain.

1997

We have cloned a putative C-type lectin of Botryllus schlosseri [Ascidiacea], whose deduced protein of 333 amino acids features three building blocks: (i) a Greek-key motif signature at the amino-terminus, (ii) a C-type lectin domain signature, and (iii) an immunoglobulin (Ig) domain at the carboxyl terminus. This C-type lectin was termed BSCLT. Similarity searches revealed that the Ig domain in BSCLT, which is evidently not polymorphic, is best classified as an Intermediate-type Ig domain. Rabbit antibodies, raised against recombinant BSCLT, cross-reacted in a Western blot with a 38-kD polypeptide in tunicate crude extract. Presumably, this bimodal tunicate protein is the first description…

The pia mater at the site of the entry of blood vessels into the central nervous system

1982

The entry of blood vessels into the central nervous system (CNS) has been studied at the surface of the brain stem and the spinal cord of two cats and two rabbits. The study was carried out by scanning electron microscopy (SEM). The results obtained by SEM concerning the layers of the pia mater corresponded to those obtained by other authors who used transmission electron microscopy. Between the basal lamina of the superficial glial membrane of the CNS and the cells lining the subarachnoid space, a pial connective tissue space could be clearly recognized. The blood vessles crossing the subarachnoid space were also covered by leptomeningeal lining cells. At the site of entry of these blood v…

Encapsulation Response ofCiona intestinalis(Ascidiacea) to Intratunical Erythrocyte Injection

1997

Abstract Electron microscopic studies on the encapsulation induced by erythrocyte injection into the tunic of the ascidian Ciona intestinalis were carried out. The observations reported in the present paper complete the description previously given of capsule architecture and contribute to the characterization of the cells involved in the inflammatory reaction. The inflamed area is surrounded by an ample and peculiar “three-layered coat” respectively composed of flattened and packed extratunical hemocytes, the monolayered epithelium, and a layer of intratunical electron-dense particles. The latter are also clustered, variously arranged, and distributed in the tunic ground substance. The epi…

Phenoloxidase-dependent cytotoxic mechanism in ascidian (Styela plicata) hemocytes active against erythrocytes and K562 tumor cells.

1997

The cytotoxic activity against rabbit erythrocytes (RE) and human K562 tumor cells by Styela plicata hemocytes was significantly related to the phenoloxidase (PO) which converts phenols to quinone and initiates the melanogenic pathway. The effector hemocyte population, separated in a Percoll density gradient band, enriched in a granulocyte type named "morula cells", was examined with RE in a hemocyte cytotoxic assay and plaque forming cell assay. Inhibition experiments with the copper chelating agents 1-phenyl-2-thiourea and tropolone, the substrate analogue sodium benzoate and sodium ascorbate support the notion that hemocyte cytotoxic activity is a PO-dependent mechanism. Treatments of he…

Scrotal Masses

2009

No abstract available

Potential Functional Significance of Brain-Type and Muscle-Type Nitric Oxide Synthase I Expressed in Adventitia and Media of Rat Aorta

1999

Abstract —Skeletal muscle and myocardium express μNOS I, an elongated splice variant of neuronal-type nitric oxide (NO) synthase (NOS I), and NOS III, endothelial-type NO synthase, respectively. This study was designed to elucidate whether vascular smooth muscle also contains a constitutively expressed NO synthase isoform. In the rat, μNOS I contains an insert of 102 nucleotides after nucleotide 2865 of the cDNA, yielding a protein of 164 kd. Reverse transcription-polymerase chain reaction with primers flanking this insert and with insert-specific primers indicated that endothelium-denuded rat aorta expresses both brain-type NOS I and μNOS I. RNase protection analyses with an antisense RNA…

Cohort profile: the cardiovascular risk in Young Finns Study.

2008

In Finland, coronary heart disease (CHD) incidence was very high in the 1960s and 1970s. In line with this high incidence, the Seven Countries Study showed that the level of serum cholesterol in Finns was also the highest among the investigated countries in the 1960s. Because several studies indicated that the atherosclerotic process starts early in life, and in accord with the World Health Organization Recommendation of 1978 which stated that studies assessing atherosclerosis precursors in children should be initiated, a program was launched in Finland in the late 1970s to study cardiovascular risk in the youth. The Cardiovascular Risk in Young Finns Study was designed as a collaborative e…