Retinoids induce Fas(CD95) ligand cell surface expression via RARgamma and nur77 in T cells

Cells from the CD4+ murine T hybridoma line IP-12-7 enter the apoptotic suicide program via the Fas ligand (FasL)/Fas-mediated pathway upon TCR stimulation. This stimulus regulates the sensitization of the Fas death pathway and the cell surface appearance of preformed FasL. The apoptosis is dependent on new mRNA and protein synthesis and involves up-regulation of nur77.Two groups of nuclear receptors for retinoic acids (RA) have been identified: retinoic acid receptors (RAR) and retinoid X receptors. IP-12-7 cells express RARalpha and RARgamma. Here we show that,in the IP-12-7 T cells, RA also induced the expression and DNA binding of nur77, and the cell surface appearance of FasL. The induction was mediated via RARgamma. Despite the induced expression of cell surface FasL, only two structurally related RARgamma-selective compounds, CD437 and CD2325, initiated apoptosis in these cells. The lack of apoptosis induction by natural RA was related to the inability of RARgamma to sensitize the Fas death-pathway. Cell surface FasL, however, was able to induce cell death in Fas-bearing target cells. Natural RA also induced the expression of FasL in phytohemagglutinin-activated peripheral murine T cells. It is proposed that therapeutically administered RA might induce apoptosis in Fas-sensitive cells via induction of FasL expression in activated Tcells.     

Human lymphocyte antigens (HLA) and Graves' disease in Turkey

To evaluate the association of HLA types with Turkish patients with Graves' disease, HLA typing, clinical findings, and thyroid antibodies were correlated. The HLA types, clinical findings (ophthalmopathy and age at onset), and thyroid stimulating hormone (TSH) receptor (TRAb) and antithyroid microsomal antibodies (MAb) were analyzed. Seventy Turkish patients with Graves' disease and 306 control subjects were assessed. Serological HLA typing was performed in HLA A, B, C, DR, and DQ loci. There was a significantly increased prevalence of HLA B8, B49, DR3, DR4, and DR10 in Graves' disease. The association of Graves' disease with HLA DR3 was found to be less strong than previously described. The HLA DR4 antigen may contribute to the predisposition of Graves' disease in Turkey. The results suggest that HLA B7, B13, DR7, DQw2, and DQw3 may confer a protective effect for Graves' disease in Turkey. Patients carrying HLA B12, B18, and B44 haplotypes had a tendency to develop the disease at a later age. The difference from the other studies may be the result of the selection of the controls; in part, of the variability in serological typing reagents; and, also, of the rather weak HLA associations with the disease.This study was presented in part at the Annual Meeting of the National Endocrinology and Diabetes Association, Bursa, Turkey, May 25–28, 1992.     

ACE Genotype May Have an Effect on Single versus Multiple Set Preferences in Strength Training

A polymorphic variant of the human angiotensin converting enzyme (ACE) gene was identified. The 'D' (rather than 'I') variant was associated with improvements in strength related to physical training. We set out to determine whether the response to different patterns of strength training might also differ. Ninty-nine Caucasian male non-elite athletes were randomly allocated into one of three groups: 31 non-training/control (CG: 31), single-set (SSG: 35) and multiple-set (MSG: 33). SSG and MSG trained three times a week for 6 weeks. Both training groups were underwent a strength-training program with two mesocycles (12-15 repetition maximum (RM) and 8-12 RM mesocycles). One RM loads in half squat and bench press were assessed before training and after the first and second mesocycles. ACE polymorphisms analysed by polymerase chain reaction (PCR) methods. Subjects with ACE II genotype in the MST group had improved strength development in 12-15 RM, while SST and MST groups had similar gains in 8-12 RM. Subjects with ACE DD genotype in both the SSG and the MSG had similar benefits from both 12-15 RM and 8-12 RM. Strength gains for subjects with ACE ID genotype in the SSG were similar to MSG gains in response to 8-12 RM loads but not with 12-15 RM loads. Additionally, subjects with DD genotype had superior strength gains in both strength training groups. Tailoring strength training programmes (single-set vs. multiple set) according to the athlete's ACE genotype may be advantageous.     

Molecular Characterization of a Full Genome Turkish Hepatitis C Virus 1b Isolate (HCV-TR1): A Predominant Viral Form in Turkey

Based on direct sequencing information from 5UTR and NS5B regions, we identified subtype 1b as a predominant hepatitis C virus genome in Turkey, which affected more than 91% of 79 patients studied. Next, the full genome sequence of a Turkish 1b isolate was obtained by the cloning of polypeptide-encoding region into 7 overlapping fragments. Turkish 1b isolate, which was named HCV-TR1, comprises 9361 nucleotides, including 306 nucleotides of 5UTR, a single long open reading frame of 9033 nucleotides, and 22 nucleotides of 3UTR. When compared to HCV 1b polypeptide sequences available at GenBank, the predicted polypeptide displayed a total of 36 amino acid substitutions, of which 16 was specific for HCV-TR1 isolate. Despite these changes, major structural and functional motifs of HCV proteins were maintained in HCV-TR1. In contrast, HCV-TR1 displayed amino acid substitutions in 6 out of 9 major cytotoxic T-cell epitopes. These data suggest that HCV-TR1 encodes functionally intact viral proteins, but it also encodes altered viral epitopes, which may affect host immune-response.     

A novel mitochondria-targeting method using special staining for the detection of apoptotic hepatocytes

ABSTRACT

Early detection of apoptotic cells on histological slides is of major importance for both diagnostic and research areas. In the current study, the aim was to propose a convenient method to stain the mitochondria and establish whether hepatocytes undergoing apoptosis can be identified in tissue sections using the proposed method. Liver tissue from five adult chinchillas was fixed with 10% neutral buffered formalin for Goldner’s trichrome (GT) and Groat’s iron hematoxylin and eosin (HE) stains and with Kolster’s fixative for the Heidenhain’s iron hematoxylin procedure. The HE and GT-stained sections showed the morphological features consistent with apoptosis i.e., homogenous intensely acidophilic cytoplasm, cell shrinkage with an irregular outline, nuclear shrinkage with cloudy karyoplasm, and karyopyknosis in the late stage. Sections stained with Heidenhain’s iron hematoxylin method was used to pinpoint mitochondria and revealed cells which were undergoing the first stages of the apoptosis process i.e., disappearance of mitochondria from the cell, chromatin condensation and margination, paracentral localization of nucleoli, and vacuolated nuclei. In more advanced stages of apoptosis, cells presented significant nuclear and cytoplasmic changes. It was concluded that this is the first report targeting the mitochondria, by performing inexpensive histological staining techniques, in order to assess dead cells in situ.     

A novel amperometric biosensor based on artichoke (Cynara scolymus L.) tissue homogenate immobilized in gelatin for hydrogen peroxide detection

A biosensor for specific determination of hydrogen peroxide was developed by using homogenized artichoke (Cynara scolymus L.) tissue in combination with a dissolved oxygen probe and applied in determination of hydrogen peroxide in milk samples. Artichoke tissue, which has catalase activity, was immobilized with gelatine by means of glutaraldehyde and fixed on a pretreated teflon membrane. The electrode response was maximum when 0.05 M phosphate buffer was used at pH 7.0 and at 30 degrees C. Upon addition of hydrogen peroxide, the electrode gives a linear response in a concentration range of 5.0-50 x 10(-5) M with a response time of 3 min. The method was also applied to the determination of hydrogen peroxide in milk samples.     

Telomere-specific fluorescence in situ hybridization analysis of couples with five or more recurrent miscarriages

Fluorescence in situ hybridization analysis using telomere specific probes has been used to detect cryptic translocations in the chromosomal telomeric regions. This study was performed in five clinically normal couples who have had five or more spontaneous abortions and whose karyotypes were found to be normal using conventional cytogenetic techniques. Using the telomere specific probes, in one couple we determined a cryptic translocation between chromosome 3 and 10, and, in another couple, the signal in chromosome 20 was detected in another chromosome, which was probably a D group chromosome. Additionally, in the latter and also in two other couples, we observed a polymorphism. The approach will be helpful for screening cryptic translocations using telomere specific multiple probe sets in couples with recurrent miscarriages. As prenatal diagnosis will be available for these couples for future pregnancies, it will be possible to help these families to have healthy fetuses.     

BHK cell attachment and growth on EDA-plasma-modified poly(L-lactide/epsilon-caprolactone) biodegradable films

In this study, attachment and growth of Baby Hamster Kidney (BHK) cells on ethylene diamine (EDA)-plasma-treated poly(L-lactide/epsilon-caprolactone) biodegradable copolymer films were investigated. The co-polymer (Mw: 58000; Mn: 35000 and PI 1.60) was synthesised by ring-opening polymerization of the respective dimers with using stannous octoate as the catalyst. The final ratio of L-lactide to epsilon-caprolactone obtained by 1H-NMR was 87:13. The co-polymer films were treated with the EDA-plasma in a glow-discharge apparatus. The BHK-30 cell line was cultured on plain and EDA-plasma-treated films and their pre-wetted forms (with ethanol and/or cell culture medium before use). Cell attachment and growth were followed. Alkaline phosphatase (ALP) activity and glucose uptake in cell culture medium were also investigated. There was no attachment in the first 12 h. Glow-discharge treatment increased significantly the attachment and growth. Pre-wetting with ethanol and cell culture medium was also increase significantly both the attachment and growth.     

Myoepithelial carcinoma in the nasopharynx: an unusual localization

Myoepithelial carcinoma is an extremely rare, malignant epithelial tumor which is usually encountered in the parotid region. In this report, a myoepithelial carcinoma arising from a minor salivary gland in the nasopharynx is presented, along with a discussion of the clinical, histopathological and immunocytochemical characteristics of this rare disorder. Larger clinical series and longer follow-up periods are needed in order to establish the best therapy option for these patients.     

Somatic mosaicism for a MECP2 mutation associated with classic Rett syndrome in a boy

Rett syndrome is a severe neurodevelopmental disorder that arises from mutations in the X-linked MECP2 gene. It is almost exclusively seen in girls due to the predominant occurrence of the mutations on the paternal X-chromosome, and also the early postnatal lethal effect of the disease causing mutations in hemizygous boys. We identified a boy with features of classic Rett syndrome who is mosaic for the truncating MECP2 mutation R270X. Chromosome analysis showed normal karyotype. These results indicate that a MECP2 mutation associated with Rett syndrome in females could lead to a similar phenotype in males as a result of somatic mosaicism.