The relationship between lysozyme gene polymorphism and quality changes during the storage of eggs derived from 2 commercial strains of Japanese quail

During the storage irreversible changes occur in eggs that result in a deterioration of their quality. The most significant changes affect the albumen. One of the major proteins of albumen present in egg white is lysozyme, which protects the embryo from microorganisms. This enzyme also contributes to the qualitative characteristics of albumen. It is possible that its polymorphism also affects the quality and stability of the obtained raw material that is, table eggs. Therefore, the aim of this study was to assess the potential effect of polymorphism in the lysozyme gene and protein on the quality changes during the storage of eggs derived from 2 genetic strains of Japanese quail belonging to various utility types. Eggs from selected females of laying and meat-type breeds were stored for 14 wk. During this period the egg quality traits were evaluated 10 times. DNA was isolated from each female and all exons of the lysozyme gene had been sequenced. In total, fourteen SNPs' and one 4-bp indel mutation were identified in exons and adjacent intronic sequences, among which SNP1 (1:32140723) resulted in a substitution of lysine with glutamine (Q21K). The results showed that SNP1 (strain S22), as well as the SNP2, SNP5, SNP7, SNP8, SNP10, SNP11, SNP12 and SNP13 were significantly associated with breaking strength during egg storage in both investigated Japanese quail strains. Furthermore, a 3 haplotype blocks containing nine SNPs (2, 5, 6, 7, 8, 10, 11, 12 and 13) were identified. These blocks displayed 8 distinct haplotypes that had significant association with breaking strength at all storage time points where egg quality analyses were performed. The study also revealed significant effects of breed and storage time on the egg quality traits. These results provide new insights into the genetic basis of egg quality during storage and could be incorporated into the breeding programs involving these strains.

Cloning of rat calcium-modulating cyclophilin ligand

Rat calcium-modulating cyclophilin ligand (CAML) cDNA was cloned and sequenced. It has a predicted open reading frame of 294 amino acids. The CAML gene is highly conserved throughout species, showing 85, 89 and 69% amino acid sequence identity to the human, mouse, and chicken genes, respectively. Gene expression data using astrocytes, microglia and neurons show that CAML mRNA and protein is constitutively expressed in these cell types of the central nervous system. The cloning of rat CAML will facilitate further investigations on the function of this molecule.

CXC chemokine receptor 4 expression and function in human astroglioma cells

Chemokines constitute a superfamily of proteins that function as chemoattractants and activators of leukocytes. Astrocytes, the major glial cell type in the CNS, are a source of chemokines within the diseased brain. Specifically, we have shown that primary human astrocytes and human astroglioma cell lines produce the CXC chemokines IFN-gamma-inducible protein-10 and IL-8 and the CC chemokines monocyte chemoattractant protein-1 and RANTES in response to stimuli such as TNF-alpha, IL-1beta, and IFN-gamma. In this study, we investigated chemokine receptor expression and function on human astroglioma cells. Enhancement of CXC chemokine receptor 4 (CXCR4) mRNA expression was observed upon treatment with the cytokines TNF-alpha and IL-1beta. The peak of CXCR4 expression in response to TNF-alpha and IL-1beta was 8 and 4 h, respectively. CXCR4 protein expression was also enhanced upon treatment with TNF-alpha and IL-1beta (2- to 3-fold). To study the functional relevance of CXCR4 expression, stable astroglioma transfectants expressing high levels of CXCR4 were generated. Stimulation of cells with the ligand for CXCR4, stromal cell-derived factor-1alpha (SDF-1alpha), resulted in an elevation in intracellular Ca(2+) concentration and activation of the mitogen-activated protein kinase cascade, specifically, extracellular signal-regulated kinase 2 (ERK2) mitogen-activated protein kinase. Of most interest, SDF-1alpha treatment induced expression of the chemokines monocyte chemoattractant protein-1, IL-8, and IFN-gamma-inducible protein-10. SDF-1alpha-induced chemokine expression was abrogated upon inclusion of U0126, a pharmacological inhibitor of ERK1/2, indicating that the ERK signaling cascade is involved in this response. Collectively, these data suggest that CXCR4-mediated signaling pathways in astroglioma cells may be another mechanism for these cells to express chemokines involved in angiogenesis and inflammation.

ICAM-1-induced expression of proinflammatory cytokines in astrocytes: involvement of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase pathways

ICAM-1 is a transmembrane glycoprotein of the Ig superfamily involved in cell adhesion. ICAM-1 is aberrantly expressed by astrocytes in CNS pathologies such as multiple sclerosis, experimental allergic encephalomyelitis, and Alzheimer's disease, suggesting a possible role for ICAM-1 in these disorders. ICAM-1 has been shown to be important for leukocyte diapedesis through brain microvessels and subsequent binding to astrocytes. However, other functional roles for ICAM-1 expression on astrocytes have not been well elucidated. Therefore, we investigated the intracellular signals generated upon ICAM-1 engagement on astrocytes. ICAM-1 ligation by a mAb to rat ICAM-1 induced mRNA expression of proinflammatory cytokines such as IL-1alpha, IL-1beta, IL-6, and TNF-alpha. Examination of cytokine protein production revealed that ICAM-1 ligation results in IL-6 secretion by astrocytes, whereas IL-1beta and IL-1alpha protein is expressed intracellularly in astrocytes. The involvement of mitogen-activated protein kinases (MAPKs) in ICAM-1-mediated cytokine expression in astrocytes was tested, as the MAPK extracellular signal-regulated kinase (ERK) was previously shown to be activated upon ICAM-1 engagement. Our results indicate that ERK1/ERK2, as well as p38 MAPK, are activated upon ligation of ICAM-1. Studies using pharmacological inhibitors demonstrate that both p38 MAPK and ERK1/2 are involved in ICAM-1-induced IL-6 expression, whereas only ERK1/2 is important for IL-1alpha and IL-1beta expression. Our data support the role of ICAM-1 on astrocytes as an inflammatory mediator in the CNS and also uncover a novel signal transduction pathway through p38 MAPK upon ICAM-1 ligation.

Aging fibroblasts present reduced epidermal growth factor (EGF) responsiveness due to preferential loss of EGF receptors

Wound healing is compromised in aging adults in part due to decreased responsiveness of fibroblasts to extracellular signals. However, the cellular mechanisms underlying this phenomenon are not known. Aged dermal fibroblasts with reduced remaining replicative capacities demonstrated decreased epidermal growth factor (EGF)-induced cell migrative and cell proliferative capacities, as reported previously. Thus, as cells approach senescence, programmed in vivo or in vitro, EGF responsiveness is preferentially lost. To define the rate-limiting signaling event, we found that the activity of two different EGF receptor (EGFR)-signaling pathways to cell migration (phospholipase-C gamma) and/or mitogenesis (extracellular signal/regulated-mitogen-activated kinases) were decreased in near senescent cells despite unchanged levels of effector molecules. Aged cells presented decreased levels of EGFR, although insulin receptor and transferrin receptor levels were relatively unchanged. EGFR mRNA levels and production of new transcripts decreased during aging, suggesting that this preferential loss of EGFR was due to diminished production, which more than counteracts the reduced ligand-induced receptor loss. Since these data suggested that the decrement in EGF was rate-limiting, higher levels of EGFR were established in near senescent cells by electroporation of EGFR cDNA. These cells presented higher levels of EGFR and recovered their EGF-induced migration and proliferation responsiveness. Thus, the defect in EGF responsiveness of aged dermal fibroblasts is secondary to reduced EGFR message transcription. Our experimental model suggests that EGFR gene delivery might be an effective future therapy for compromised wound healing.

[Surgical treatment of GnRH secretory hypothalamic hamartomas causing precocious puberty]

Hypothalamic hamartomas (HHs) are benign lesions often associated with central precocious puberty. Resection of HHs has been recommended as a treatment option for selected cases, however recent reports stressed the role of effective medical management with a long-acting GnRH agonist. This paper describes incomplete response to the initial GnRH therapy and results of total resection of HHs. Five children two boys and three girls with physical signs of puberty at a mean age of 20.2 months (range 5-36 months) have been treated at our institution. All children had a pedunculated mass below the tuber cinereum. Two children were initially treated with GnRH agonist and had received follow-up care for 11 and 12 months respectively. These patients had incomplete regression of endocrinological disturbances to prepubertal level. Both patients were subsequently operated on. All five children underwent total surgical removal of HHs. The hamartomas were excised through pterional approach. Postoperatively two children showed transient third nerve palsy and one diabetes incipidus. There was no permanent disability due to surgical intervention. The clinical and biochemical symptoms and signs of precocious puberty completely regressed postoperatively including two cases treated initially with GnRH analog. The children have been followed for 1 to 6 years and no recurrence of puberty was observed. Surgical excision of pedunculated HHs is still a valuable option in the treatment of precocious puberty in small children. This alternative should be considered if the initial GnRH therapy failed to suppress++ puberty and reduce bone age advancement.

[Preliminary results of the treatment of occlusive hydrocephalus in children by endoscopic techniques]

The group of 20 patients with the preliminary diagnosis of occlusive hydrocephalus were treated by neuroendoscopic technique. Ten ventriculocystocisternostomies in cases with third ventricle arachnoid cysts accompanied by hydrocephalus, 9 ventriculostomies, and 1 ventriculostomy with fenestration of posterior fossa cystic lesion were performed. It was proven that the neuroendoscopic procedures were effective in 17 cases (85%) in the 10 months mean follow-up period of the study group. With no mortality, transient surgical complications were observed in 5 cases (25%). In 3 cases, inefficacy of the method was caused by false preoperative evaluation, and inappropriate surgical technique.

[Immunohistochemical and ultrastructural studies of subependymal giant cell astrocytomas in children with tuberous sclerosis]

Ten cases of subependymal giant cell astrocytoma associated with sclerosis tuberosa were reevaluated in order to assess their phenotyping and biologic features. All tumours were multifocal, located within lateral ventricles, often overlying the head of the caudate nucleus or protruding into the third ventricle. The phenotype of SGCA disclosed a complex pattern: giant cells were GFAP positive, some of them were stained with antibodies against neurofilament and NSE. Ultrastructurally, the cells of SGCA contained frequent dense bodies, numerous intermediate filaments and microtubules. Biologically SGCA is not malignant, although its appearance may suggest otherwise. No patient had an apparent recurrence within 3-5 years of observation.

Surgical treatment of intraventricular tumors associated with tuberous sclerosis

Six children with intraventricular tumors associated with tuberous sclerosis (TS) were treated at the Children's Health Center, Department of Pediatric Neurosurgery, in the period 1987-1992. The age of the patients ranged from 7 to 15 years. TS was diagnosed according to Gomez diagnostic criteria. Computer tomography (CT) and magnetic resonance imaging showed intraventricular tumors associated with ventricular enlargement and multiple subependymal nodules commonly observed in cases of TS. All tumors were removed totally through frontal transcortical approach, with uneventful postoperative recovery. One patient, with two parallel tumors in the two frontal horns, underwent one-stage surgery with successful total removal. Histopathological examination in all cases showed subependymal giant cell astrocytoma (SGCA). The growth pattern of SGCA associated with TS, documented by sequential CT scans over several years, is described. The diagnosis and surgical treatment of the tumor are discussed, and periodic CT scanning, at least every 2 years, is recommended for patients with TS.