Molecular genetic alterations of FHIT and p53 genes in benign and malignant thyroid gland lesions

Several oncogenes and tumor-suppressor genes are involved either as early or late event in thyroid gland carcinogenesis. Human FHIT (fragile histidine triad) gene is highly conserved gene whose loss of function may be important in the development and/or progression of various types of cancer. We undertook this study to analyze FHIT and p53 gene status in different benignant and malignant thyroid tumors. Status of these genes as well as intensity of apoptosis was analyzed in tumor tissues by molecular genetic methods, immunohistochemistry, and FACS-scan analysis. The majority of the malignant thyroid cancers displayed aberrant expression of FHIT gene, concominant with p53 gene inactivation. This is followed by low rate of apoptosis, which may be important in the development and/or progression of thyroid cancer. We found higher incidence of p53 mutation and aberrant processing of FHIT mRNA in malignant tumors (papillary, follicular, medullary and anaplastic carcinomas) and in those tumors with distant metastasis. The growth of p53(-)/FHIT(-) follicular carcinoma of human origin was much faster in nude mice than p53(+)/FHIT(+) follicular carcinoma, and mice had shorter survival rate. Our results show a correlation between aberrant FHIT and p53 expression, low rate of apoptosis, and malignancy. Concomitant aberration of FHIT gene and p53 could be responsible for development of highly malignant types of thyroid cancer and may be considered as a prognostic marker for these tumors.     

Brain and sperm cell surface antigen (NS-4) on preimplantation mouse embryos

Antiserum prepared in rabbit against 4-day-old mouse cerebellum (anti-NS-4 serum) reacts in the complement-mediated cytotoxicity test with unfertilized and fertilized mouse eggs, cleavage stage embryos, and cells of the trophoblast and inner cell mass of the mouse blastocyst. This activity is specifically removed by absorption of antiserum with adult mouse brain and epididymal sperm but not with adult liver, spleen, kidney, and thymocytes. The antiserum reacts most strongly with cells of the trophoblast and inner cell mass and, in order of decreasing reactivity, with four- to eight-cell stage embryos, zygotes, unfertilized eggs, and two-cell stage embryos.     

Changes in cell surface proteins during differentiation of mouse embryonal carcinoma cells

The cell surface proteins of teratocarcinoma-derived embryonal carcinoma cells (ECC), of parietal endoderm (Pys-2 and F9-AC cl 9), and of fibroblasts (OTT6050f) were radioiodinated by a lactoperoxidase method and analyzed by two-dimensional gel electrophoresis. The combined electrophoretic profiles of proteins from a number of ECC lines allowed the determination of eight ECC-unique polypeptides. Parietal endoderm and fibroblast expressed their own unique polypeptides. The two parietal endoderm-specific polypeptides are identical to the subunits of laminin. Retinoic acid-induced differentiation of one ECC line (F9) resulted in the disappearance of polypeptides specific for ECC and the appearance of those specific for the parietal endoderm.     

Influence of different etching times on dentin surface morphology

The aim of this study is to investigate the influence of different etching times on demineralized dentin surface morphology using scanning electron microscopy and qualitative line microanalysis of chemical structure. Two sample groups, consisting of 30 first premolar teeth in each group, were established. Teeth were cut at the half-distance between the enamel-dentin junction and the pulp. The first group of specimens was etched for 10 seconds and the second group for 30 seconds. 37% ortophosphoric acid was used. SEM (scanning electron microscopy) was utilized to observe the following parameters: number and diameter of dentinal tubules, dentinal and intertubular dentinal surface percentage, appearance of the dentin surface porous zone containing smear layer and demineralized residual collagen particles with dentin demineralization products in acid globules, and dissolved peritubular dentin cuff. After calculating measurements of central tendency (X,C, Mo, SD), Kolmogorov-Smirnov and Student t-test were performed to confirm the quantitative results, and the chi2-test was run to produce qualitative data. In contrast to the 10-second etching time, the increased etching time of 30 seconds resulted in the following findings: (1) an increased number of dentinal tubules (p < 0.05), (2) an increase in dentinal tubule diameter (p < 0.05), (3) an increase in dentinal tubule surface percentage (p < 0.001), (4) a decrease in intertubular dentinal surface percentage (p < 0.001), (5) appearance of dentin surface porous zone containing smear layer and demineralized residual collagen particles with dentin demineralization products in acid globules (p < 0.001), and (6) completely dissolved peritubular dentin cuff (p <0.001). Therefore, different etching times using the same phosphoric acid concentration result in different morphological changes in demineralized dentin surface. Moreover, based on a comparison with current studies, prolonged etching time causes morphological changes to dentin surface. Such changes, have, in turn, negative effects on the dentin hybridization process.     

The expression of neurotrophins and their receptors in the prenatal and adult human testis: evidence for functions in Leydig cells

Previous studies have demonstrated local functions for neurotrophins in the developing and mature testis of rodents. To examine whether these signaling molecules are present and also potentially active in the human testis, we characterized immunohistochemically the expression and cellular localization of the known neurotrophins and their receptors during prenatal testicular development as well as in the adult human testis. Results obtained revealed the presence of nerve growth factor (NGF), brain-derived neurotrophic factor, neurotrophin-3 and 4, as well as neurotrophin receptors p75^NTR, TrkA, TrkB, and TrkC during testis morphogenesis. These proteins were also detectable in the adult human testis, and their local expression could be confirmed largely by immunoblot and RT-PCR analyses. Remarkably, the Leydig cells were found to represent the predominant neurotrophin/receptor expression sites within both fetal and adult human testes. Functional assays performed with a mouse tumor Leydig cell line revealed that NGF exposure increases cellular steroid production, indicating a role in differentiation processes. These findings support previously-recognized neuronal characteristics of Leydig cells, provide additional evidence for potential roles of neurotrophins during testis morphogenesis and in the mature testis, and demonstrate for the first time a neurotrophin-induced functional activity in Leydig cells.     

Doppler-echocardiographic characteristics of left ventricular function in patients with pseudoexfoliation glaucoma: a preliminary report

Glaucoma is associated with an increased incidence of cardiovascular disease and risk factors. The aim of the study was to assess the left ventricular (LV) function in patients with pseudoexfoliation (PEX) glaucoma using doppler-echocardiographic examinations. Two-dimensional and pulsed Doppler echocardiography of transmitral flow was performed in 21 patients with (PEX) glaucoma and 24 controls. LV systolic contraction and ejection were assessed using the LV ejection fraction (EF) and fractional shortening (FS). LV diastolic filling assessed parameters were: early, fast diastolic filling (E wave), late diastolic filling (A wave), ratio E/A, velocity time integral E wave (VTIE) and A wave (VTIA), their ratio (VTIE /VTIA), pressure at the end of filling (LVEDP) and a pulmonary capillary wedge pressure (PCWP). A significant difference was found concerning LV filling flow parameters in E, E/A, VTIA and ratio VTIA/ VTIE. No significant difference was found in EF, FS, A, VTIE, LVEDP and PCWP tested parameters. Our study indicates the possibility of slightly impaired diastolic function of LV in patients with PEX glaucoma assessed by Doppler-echocardiographic examinations.     

Association of refractory complex partial seizures with a polymorphism of ApoE genotype

Apolipoprotein E (ApoE) is a constituent of many types of lipoproteins that play a role in metabolism of cholesterol and lipids in the body as well as in the brain. ApoE is synthesised in astrocytes and microglia and enter to neurons through LDL, LRP and VLDL receptors. Recently it was shown that ApoE is also produced in neurons. ApoE has a role in modulating learning and memory, structural plasticity, mobilization of cholesterol in repair, growth and maintenance of myelin and neuronal membranes during development and aging, and cell death after ischemic, convulsive, or other type of brain injury. The aim of this research was to investigate the possible association of ApoE gene polymorphism with the development of resistance to pharmacological therapy in patients with partial complex seizures with or without secondary generalization. In this prospective matched-pair controlled study, 60 patients with cryptogenic epilepsy with complex partial seizures, with or without secondary generalization, who have been suffering for five or more years, were studied. The first group comprised 30 patients refractory to the current therapy, while the second group consisted of patients with well-controlled seizures. The refractory and non-refractory groups of patients differed significantly in their phenotypes. Phenotype E3/4 was six times more frequent in refractory group than among non-refractory group. The lack of response was shown to be significantly associated with the presence of epsilon4 allele. This study provided evidence that the presence of epsilon4 allele is more often associated with a lack of response to current antiepileptic drugs as compared to epsilon2 and epsilon3 alleles.     

Efficiency of polylactide/polyglycolide copolymers bone replacements in bone defects healing measured by densitometry

Healing of bone defects is the most frequent cause of failure in surgical treatments of an odontogenic ostitic processes. The aim of this study was to determine successfulness in healing of bone defects after implantation of alloplastic co-polymer-polyglycol bone implant. A group of 45 cases with periradicular ostitic processes were examined. The densitometric measurements were taken from radiovisiographic dental x-ray images. Patients were observed throughout a period of one year. The results obtained were analyzed and presented graphically. Thirty-eight patients (84%) were treated successfully, and seven patients (16%) showed unsuccessful healing of the bone defects. The results obtained indicate that polyglycol copolymer bone implants can be successfully used in a treatment of odontogenically caused bone defects. Their fundamental advantage is a slow biodegradation, which ensures a more suitable area for the apposition of a new bone in the defect, simple application in clinical work and the possibility of a mutual combination of all three available forms.