Recurrence of atrial fibrillation after pulmonary vein isolation in dependence of arterial stiffness.

BACKGROUND: Arterial stiffness (AS) has emerged as a strong predictor of cardiovascular (CV) diseases. Although increased AS has been described as a predictor of atrial fibrillation (AF), its role as a risk marker for AF recurrence has not yet been elucidated. METHODS: Patients with AF who underwent pulmonary vein isolation (PVI) were included in this study. Presence of AS was evaluated by measuring aortic distensibility (AD) of the descending aorta by transoesophageal echocardiography. RESULTS: In total, 151 patients (mean ± standard deviation (SD) age 71.9 ± 9.8 years) were enrolled and followed for a median duration of 21 months (interquartile range 15.0-31.0). During follow-up, AF recurred in 94 (62.3%) patients. AF recurrence was seen more frequently in patients with permanent AF (27% vs 46%, p = 0.03) and in those who had undergone prior PVI (9% vs 23%, p = 0.02). AD was significantly reduced in patients with AF recurrence (mean ± SD 2.6 ± 2.3 vs 1.5 ± 0.7â€¯× 10-3 mm Hg-1, p < 0.0001), as well as left atrial volume index (LAVI) (mean ± SD 29 ± 12 vs 44 ± 15 ml/m2, p < 0.0001). Multivariable analysis revealed LAVI (odds ratio (OR) 2.9, 95% confidence interval (CI) 1.2-3.4) and AS (OR 3.6, 95% CI 2.8-4.1) as independent risk factors of AF recurrence. CONCLUSION: Increased AS and left atrial size were independent predictors of AF recurrence after PVI. AD as surrogate marker of AS seemed to reflect the overall CV risk. In addition, AD was significantly correlated with left atrial size, which suggests that increased AS leads to atrial remodelling and thus to AF recurrence. TRIAL REGISTRATION: German registry for clinical studies (DRKS), DRKS00019007.

NGF overexpression and distribution in cortical thymic epithelial cells of mice with experimentally-induced leukemia.

BACKGROUND: Thymic epithelial cells often form lymphoid-epithelial cell (LEC) complexes, thought to contribute both to normal T-cell differentiation and to leukemogenesis. The distribution of the nerve growth factor (NGF) and NGF immunoreactivity modulation of complex-forming thymus epithelial cells were studied in mice with experimental acute L1210 leukemia. MATERIALS AND METHODS: Light and electron microscopic methods and cell separation techniques were applied. RESULTS: Immunoperoxidase and immunogold labelling showed subcapsular and subseptal overexpression of NGF by epithelial cells in leukemic thymus. NGF immunopositive epithelial cells were closely associated with lymphoid cells. The increased immunoreactivity of epithelial cells correlated with LEC complex formation, including thymic nurse cell-like structures and rosettes in the external cortex. CONCLUSION: These results provide new structural and immunocytochemical evidence for intimate contact between NGF-producing epithelial cells and lymphoid cells and suggest that NGF immunoreactive LEC complexes are involved in thymic microenvironmental reorganization during leukemogenesis.

Cellular localization of NGF and NGF receptors in aged human thymus.

Recent evidence indicates that some thymic cells of developing and adult laboratory animals express the neurotrophin NGF and its low-affinity p75NTR and high-affinity TrkA receptor. Less is known as to whether the thymus of adult and aged humans express these markers. We hypothesize that the presence and distribution of immunopositive cells for NGF and NGF receptors undergo some alterations during the involution of human thymus. Specimens from normal thymuses of old individuals were obtained from autopsy and surgery cases, and examined immunocytochemically at the light and transmission electron microscopic level. The immunoreactivity of NGF, p75NTR, TrkA and cytokeratin was found in the epithelial thymocyte microenvironment. Our results provide the first ultrastructural evidence for NGF/receptor immunocytochemical localization in human thymus. They suggest a possible immunotrophic/immunoregulatory role of the NGF-p75NTR-TrkA system for T-cell development in human thymus during senile involution.

Asymmetric vimentin distribution in human spermatozoa.

The subject of the study was vimentin distribution in spermatozoa from human ejaculates by immunofluorescence and immunogold electron microscopy. In accordance with earlier reports, vimentin was found in the sperm head and was localized mainly in the equatorial segment region. However, electron microscopic observations revealed an additional intriguing detail: vimentin-associated gold granules showed asymmetric distribution. This asymmetry tended to be more pronounced in heads with defects such as cytoplasmic droplets. Abnormal cells also had positive reaction for vimentin in the neck and the proximal midpiece, but in these domains gold granule distribution was apparently uniform. These findings seem to support the hypothesis that the surfaces of the mammalian sperm head are functionally non-equivalent, although morphological basis for such a phenomenon is evident only in rodents. It is also interesting that asymmetry in vimentin distribution correlates with distinct types of sperm structural defects.

Presence of HLA-DR immunopositive cells in human fetal thymus.

Several kinds of thymic cells express MHC class II antigens, including human-leukocyte-associated antigen-DR (HLA-DR) during postnatal development. The present study was focused on the detection and analysis of HLA-DR immunoreactivity in human fetal thymuses (6-7th month of gestation). Using monoclonal antibodies, indirect immunoperoxidase staining (IIP), immunogold electron microscopy (IGEM), enzyme-linked immunosorbent assay (ELISA) and flow cytometry, HLA-DR immunopositive (IP) thymic cells were found in samples studied. IIP and IGEM demonstrated the presence of HLA-DR IP stromal cells (SCs): epithelial cells (ECs), dendritic-like cells (DCs) and macrophages (MCs) as well as HLA-DR IP lymphocytes (Lys) in all thymic regions. HLA-DR immunoreactivity was more prominent in the medullary ECs (mECs) than in the cortical ECs (cECs). Strong staining of Hassall's corpuscles and the adjacent mECs was seen. The differences in the intracellular distribution of HLA-DR molecules were detailed by IGEM as a first attempt to analyse HLA-DR IP cells at ultrastructural level. ELISA data and two-colour flow cytometric analysis revealed the presence of HLA-DR IP and HLA-DR/CD3 double IP Lys in accordance with the immunocytochemical assays. The results presented enrich the information about HLA-DR IP components of the thymic microenvironment in developing human thymus and raise the question of their role during prenatal T cell differentiation and selection processes.

EGF receptor-like determinants on human spermatozoa and their possible cytoskeletal association.

The study was focused on the localization of human sperm epidermal growth factor receptor and its resistance to Triton X-100 extraction, indicating possible cytoskeletal association. Human spermatozoa were subjected to immunofluorescence and pre-embedding immunoelectron microscopy using anti-EGF receptor monoclonal antibody as a probe. In detergent-untreated cells, the entire head was stained with intensity declining towards the acrosomal tip. Triton-extracted spermatozoa were stained predominantly in the equatorial segment region. Electron microscopy performed after extraction revealed that the label was also present in the equatorial segment and localized to electron-dense material overlying the acrosomal remnants. This Triton-resistant staining could imply cytoskeletal association of the EGF receptor in the equatorial segment, with possible importance in fertilization.

Heterogeneity in the presence of CD4-like molecules on human spermatozoa.

The object of the present study was to study if there are differences in the presence of CD4-like molecules on human ejaculated spermatozoa in fertile donors and infertile patients (with globozoospermia). Indirect and absorption enzyme-linked immunosorbent assay and indirect immunofluorescence were applied. The enzyme-linked immunosorbent assay data showed that monoclonal anti-human CD4-antibody recognizes an epitope common to the human spermatozoa with normal morphology and round-headed spermatozoa. Localization of the antigenic determinants, identified by anti-human CD4-monoclonal antibody, in the acrosomal region, including equatorial segment, postnuclear cap and tail was determined in normozoospermic samples. A positive reaction was found on the sperm head both in the acrosomal and postacrosomal region of some round-headed spermatozoa in the samples with globozoospermia. The tails of the normozoospermic spermatozoa and of some round-headed spermatozoa were weakly immunopositive. The results of the experiments carried out are evidence of heterogeneity in the presence of CD4-like antigen determinants on human spermatozoa. These data increased the information about the CD4-antigen characteristic of the spermatozoa from fertile donors and infertile patients.

Distribution of vimentin in abnormal human spermatozoa.

Vimentin was immunocytochemically detected using a monoclonal anti-vimentin antibody and indirect immunogold electron microscopy. In abnormal human spermatozoa, vimentin was visualized at the level of whole acrosome, post-acrosomal region, neck and initial segment of the mid piece. The distribution of vimentin immunoreactivity was related to a spectrum of structural defects such as large cytoplasmic droplets, binucleated spermatozoa and mitochondrial disassembly in the mid piece.

Binding and internalization of gold-labeled insulin complex by thymic cells.

Colloidal gold-labeled insulin complex was used for the ultrastructural visualization of insulin binding sites on the cell surface and to study the intracellular pathway of insulin. Thymic epithelial cells and thymic lymphoid cells from mammalian fetuses (mouse, rat, man) were investigated. The results show that all epithelial cells and some lymphoid ones bind insulin during fetal life. Certain fine structural features (single gold particles, patches and clusters of gold granules on the cell membrane) which are common for both kinds of thymic cell lines are established. Uncoated pinocytotic invaginations (more rarely via coated pits), tubulo-vesicles, uncoated vesicles, intermediate filaments and microtubules are related to insulin gold complex intracellular pathway in the epithelial cells. However, these peculiarities as a whole are noted typically in the lymphoid cells. These data suggest that the ability to cap and to internalize IGC is directly associated with thymic cell type and similar in principle to both cellular types (epithelial and lymphoid cells) in all mammalian fetuses studied.

[Role of pain component in the organization of chemosensory taste reaction]. / Rol' bolevogo komponenta v organizatsii khemosensornoi vkusovoi reaktsii.

The investigation of algoinductor (histaminergic) and peptidergic relations in peripheral pain reaction of taste was performed by using of different histamine liberators (applied on tongue). By fluorescence-histochemical methods it was shown that histamine in the apical portion of papilla is derived from cells of taste buds and in the basal zone--from connective tissue cells (including mast cells). It was established in behavior trials on peptidergic system that consumption of taste solutions became changed. It was suggested that histaminergic structures together with SP-containing fibers ensure food controlling in oral cavity.

The ontogeny of human thymic epithelium specific antigens as defined by monoclonal antibodies.

The ontogeny of human thymic epithelial antigens was studied by the use of monoclonal antibodies and immunohistological techniques. The results show that the T2/30 antigen, specific for cortical epithelial cells appears later than the BH11, BC3 and AG3 antigens. This is the first demonstration of the developmentally regulated appearance of a thymic epithelium specific antigen (not present in other epithelial cells e.g., skin, mucosa).

Immunological screening of welders.

74 healthy welders were subjected to immunological screening. Serum immunoglobulins (IgG, IgA, IgM) were measured as well as total and active E-RFC and cellular immunity was evaluated using the intradermal testing of PPD, candidin D-7, trichophytin D-5 and tetanus anatoxin. The obtained results suggest suppression of the T and B lymphocyte immune systems as expressed by decreased levels of serum IgG and total E-RFC. Cell-mediated immune deficiency was found in 21.6% welders. Suppression of the immune system may be accounted for by a complex effect of occupational factors, such as manganese compounds, vibration and noise.

Structural and histochemical features of cortical thymic epithelial cells in mice with chemically-induced lymphoid leukemia.

Ultrastructural, enzyme histochemical (acide phosphatase, adenosine triphosphatase, neutral 5'-nucleotidase) and immunohistochemical (cytokeratins with monoclonal antibodies BH11 and BC3) features of the thymus cortical epithelial cells of leukemic DBA/2 inbred mice have been studied. In the leukemic mice epithelial cells appeared possessing some ultrastructural and histochemical features of cell activation. Lympho-epithelial complexes, composed mainly of BH11 and BC3 immunoreactive cells and of lymphoid cells were subcapsulary and subseptally found. It is discussed on the eventual involvement of the lympho-epithelial complexes in the intrathymic leukemogenesis during lymphoid leukemia.

[Ultrastructural characteristics of the epithelial cells of the cortico-medullary transition layer in the mouse thymus]. / Ultrastrukturni osobenosti na epitelnite kletki ot kortiko-medularniia prekhod na timus na mishka.

The authors examined the fine structure of the epithelial cells, obtained from the cortico-medullary transition in the thymus of 4-months conventional mice Swiss, killed by decapitation. Apart from dark and bright epithelial cells, which formed cellular reticulum of the whole thymic lobule, they described three types of epithelial cells, characteristic of this area. These cells differed mainly by the character of their vascular components, whose richness and variety was combined with other cytologic signs of increased functional activity, manifested at various degree. The obtained results widened the picture of the cortico-medullary transition as an area, independently formed in other breeds of animals with data of a thymus similar to that of a mouse and were morphologic proof for the significance of its epithelial reticulum in the functional activity of the thymus.