Effect of negative air ions on computer operation, anxiety and salivary chromogranin A-like immunoreactivity.

The effects of negative air ions on computer operation were examined using a biochemical index of the activity of the sympathetic/adrenomedullary system (i.e. salivary chromogranin A-like immunoreactivity (CgA-like IR)) and a self-report questionnaire (State-Trait Anxiety Inventory, Anxiety State--STAI-S). Twelve female students carried out a word processing task for 40 min. The salivary CgA-like IR increased more than three times on the task, but the salivary cortisol did not change. The increase in the CgA-like IR level was attenuated by the exposure to negative air ions during the task. The exposure to the ions during the recovery period following the task was effective for rapidly decreasing the CgA-like IR level that had increased after the task. These effects by negative air ions were also observed using STAI-S. Task performance was slightly but significantly improved by the presence of negative air ions. These results suggest that negative air ions are effective for the reduction of and the prompt recovery from stress caused by computer operation.     

An image-based modeling framework for patient-specific computational hemodynamics

We present a modeling framework designed for patient-specific computational hemodynamics to be performed in the context of large-scale studies. The framework takes advantage of the integration of image processing, geometric analysis and mesh generation techniques, with an accent on full automation and high-level interaction. Image segmentation is performed using implicit deformable models taking advantage of a novel approach for selective initialization of vascular branches, as well as of a strategy for the segmentation of small vessels. A robust definition of centerlines provides objective geometric criteria for the automation of surface editing and mesh generation. The framework is available as part of an open-source effort, the Vascular Modeling Toolkit, a first step towards the sharing of tools and data which will be necessary for computational hemodynamics to play a role in evidence-based medicine.     

Biofluid Aspects of Embryo Transfer

Embryo transfer (ET) is the last stage of extracorporal fertilization during which the embryo is placed in the uterine cavity with a medium-filled catheter 2–3 days after in vitro fertilization. While fertilization in the laboratory occurs at very high rates (>:90%), the overall success of the procedure (i.e., take home baby) is still very low (<25%) and assumed to be mainly due to implantation failure. A computational model was developed to simulate ET within the uterine cavity by a fluid-filled catheter inserted into a two-dimensional channel with oscillating walls. The results showed that the speed at which the embryos are injected from the catheter dominates the procedure and controls the velocity of their transport within the uterine cavity. ET at excessively high injection speeds may lead to ectopic pregnancies, while uterine peristalsis affects transverse dispersion only during injection at low injection speeds. The presence of the catheter within the uterus does not affect flow patterns downstream of its tip. The potential risks to implantation failure due to mechanical factors involved in the ET processes are discussed. © 2003 Biomedical Engineering Society. PAC2003: 8719-j, 8710+e     

A Model for Transport and Dispersion in the Circulatory System Based on the Vascular Fractal Tree

Materials are distributed throughout the body of mammals by fractal networks of branching tubes. Based on the scaling laws of the fractal structure, the vascular tree is reduced to an equivalent one-dimensional, tube model. A dispersion–convection partial differential equation with constant coefficients describes the heterogeneous concentration profile of an intravascular tracer in the vascular tree. A simple model for the mammalian circulatory system is built in entirely physiological terms consisting of a ring shaped, one-dimensional tube which corresponds to the arterial, venular, and pulmonary trees, successively. The model incorporates the blood flow heterogeneity of the mammalian circulatory system. Model predictions are fitted to published concentration-time data of indocyanine green injected in humans and dogs. Close agreement was found with parameter values within the expected physiological range. © 2003 Biomedical Engineering Society. PAC2003: 8710+e, 8719Hh, 8719Uv     

Intra-uterine physical growth in schizophrenia: evidence confirming excess of premature birth

BACKGROUND: Many studies have suggested a possible aetiological role for obstetric complications in the development of schizophrenia. We focused on prenatal physical growth in schizophrenia, a contentious issue in the literature. METHODS: We compared gestational age at birth, birth weight (BW) and birth head circumference (BHC) between 312 schizophrenics and 517 controls, and between 187 schizophrenics and their matched healthy siblings. Information on obstetric histories was obtained from the Maternal and Child Health Handbooks (i.e. contemporaneous records). RESULTS: Gestational age at birth was significantly earlier in the schizophrenics than in the controls (P = 0.017). Pre-term birth (gestational age of 36 weeks or less) was more common in schizophrenics than in controls (8.0% v. 3.4%, P = 0.005, odds ratio 2.5). Low BW (2500 g or less) was more frequent in schizophrenics than in controls (9.6% v. 4.6%, P = 0.005, odds ratio 2.2). The schizophrenics had significantly lighter BW (P = 0.0003) and tended to have smaller BHC (P = 0.081) compared with controls. However, multiple regression analysis showed that there was no significant difference in BW or BHC between the schizophrenics and controls when gestational age and maternal weight were controlled. There was no significant difference in BW or BHC between schizophrenics and their siblings, although the schizophrenics tended to be born at earlier gestational age than their siblings. CONCLUSIONS: Our results suggest that prematurity at birth is associated with a risk of developing schizophrenia in adulthood. When gestational age and maternal body weight were allowed for, there was no evidence that schizophrenics tend to have lower mean BW or smaller BHC.     

Cytochemistry and morphology of granulocytes of the caecilian <Emphasis Type="Italic">Siphonops annulatus</Emphasis> (Amphibia,Gymnophiona)

The caecilians (Amphibia, Gymnophiona) constitute one of the least known groups of terrestrial vertebrates because most species live underground in quite inaccessible environments. Siphonops annulatus is an exclusively fossorial species and is the most extensively distributed caecilian in South America. Little is known of this order concerning circulating granulocytes, including their morphological and cytochemical structure and ultrastructure. This paper is part of a project covering the study of granulocytes in representative species of the order Amphibia. Blood extensions were carried out and submitted to Leishman, Toluidine Blue, Periodic acid Schiff, Sirius Red and hydrogen o-toluidine peroxide methods. Part of the samples was prepared for conventional transmission electron microscopy. Among granular leukocytes, mature and immature neutrophils and eosinophils were identified, plus basophils. The most frequent granulocyte encountered in S. annulatus peripheral blood is the neutrophil. This is a cell with a hyper-segmented nucleus and with a very clear cytoplasm when compared to the eosinophil, which presents large cytoplasmic acidophilic granules. On the other hand, the basophils present basophilic and metachromatic granules. Glycogen was detected in the cytoplasm of the neutrophils and eosinophils, while basic protein rich in amino acids was observed in the eosinophil’s granules. Myeloperoxidase activity was detected in the cytoplasm of the neutrophils and eosinophils. Neutrophils were ultrastructurally detected with three types of small granules: eosinophils with large and small spherical granules and basophils with large spherical granules with lamellate structures.     

Elucidating chromatin and nuclear domain architecture with electron spectroscopic imaging

Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic leukemia nuclear bodies. The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced through the technical creativity she provided.     

VAMP2 is expressed in myogenic cells during rat development

Vesicle-associated membrane protein 2 (VAMP2) is a member of the SNARE family of proteins that regulate the intracellular vesicle fusion process. This study investigated the developmental expression of VAMP2 in the rat embryo. In the trunk, VAMP2 was primarily found in the heart on embryonic day (E) 10. On E12.5, VAMP2 expression was found in nerve fibers, somites, and heart. In somites, epithelial cells in the dorsomedial lip, and elongated myoblasts in myotome were positive for VAMP2. On E16.5, VAMP2 was expressed in the heart, nerve fibers, and skeletal muscles. In skeletal muscles, multinuclear myotubes were positive for VAMP2. In the head, where muscles are derived both from somitic and non-somitic origin, VAMP2 was found in myotubes of the extrinsic ocular muscles and masseter muscle on E16.5. These findings suggest the involvement of VAMP2 in the development of skeletal muscles of somitic and non-somitic origins.