Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lateral Line System”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,333 records · Page 74Linked to original sources
PubMed1991

Cultured proliferating rat mammary epithelial cells.

Normal epithelial cells from the rat mammary gland proliferated in culture when plated with lethally irradiated cells of the LA7 rat mammary tumor line. Proliferation of the normal rat cells occurred as the LA7 cells slowly died from the radiation. By labeling the cultures with 3H-thymidine it was determined that most of the proliferating rat cells were those adjacent to the LA7 feeder cells. The epithelial cells from the primary culture proliferated after subsequent passages if the cells were plated at each subculture with newly irradiated LA7 cells. If the cells were plated at a ratio of approximately 1:8 rat:LA7 a confluent layer of normal rat cells covered the plastic substrate after 6 to 7 wk. The cells have so far been carried up through Passage 7, which amounted to approximately 19 doublings in cell number, and still proliferate vigorously. The growth medium for this culture system was Dulbecco's modified Eagle's medium:Ham's F12 1:1 supplemented with fetal bovine serum, insulin, and antibiotics. The presence in the cells of keratin, desmosomes, and cell junctions attested to their epithelial origin. The cultures were composed of cells with diploid or near diploid chromosome numbers. Samples of the cultured cells were implanted into the cleared fat pads of nude mice. Most of the implants from Passage 2 formed normal mammary ductal structures, but the incidence of outgrowths decreased significantly with later passages until no outgrowths resulted from the implantation of cells from Passage 5. The one unusual, feeder-independent cell line that arose from a primary culture seemed to be immortal in culture, contained a hyperdiploid chromosome complement, and formed abnormal structures when implanted into cleared fat pads.

Animals↗
PubMed1998

[Asynchrony of ventricular contraction and relaxation--pathophysiologically recognized phenomenon, now can be clinically assessed].

When regional myocardial dysfunction is present, the physiological pattern of ventricular filling and contraction is impaired. During acute coronary occlusion, characteristic changes are observed in the ischemic myocardial segment: the amplitude of the systolic wall thickening is reduced (hypokinesia), then virtually absent (akinesia) and finally replaced by a paradoxical outward motion (dyskinesia). The maximum amplitude is reached in early diastole ("post-ejection thickening"). Since hyperkinesis develops in the normal region, the ischemic and the normal region contract asynchronously. Experimentally left ventricular asynchrony can be detected by means of subendo- and subepicardially implanted ultrasonic crystals ("sonomicrometry") or by the analysis of the phase difference of the first Fourier harmonic of dysfunctional versus control myocardial wall motion. In the clinical setting, digitized cineventriculography, radionuclide angiography and digitized M-mode echocardiography were used to assess left ventricular asynchrony in patients with coronary artery disease and hypertrophic cardiomyopathy. However, these imaging modalities are time-consuming and require complicated off-line analysis. Tissue Doppler echocardiography (TDE) is a new ultrasound modality that is based on color Doppler principles and allows for quantification of myocardial wall motion velocity by detection of consecutive phase shifts of the ultrasound signal reflected from the myocardium. The Doppler signals are displayed as a color or pulsed Doppler image by rejecting low-amplitude echoes from the blood pool due to changes in thresholding and filtering algorithms. In addition, the ability to measure low velocity is improved in the TDE system so that the lowest measurable velocity is 0.2 cm/s, a velocity level associated with cardiac tissue motion (Table 1). Due to its high temporal and spatial resolution, TDE provides valuable information on regional myocardial wall motion during different intervals of the cardiac cycle. In healthy subjects, patients with coronary artery disease and patients with hypertrophic cardiomyopathy, tissue Doppler echocardiography was used to assess myocardial synchrony/asynchrony on a 2-fold temporal and spatial analysis. Peak myocardial velocities in different myocardial regions were detected during rapid ejection, isovolumic relaxation, rapid filling and atrial contraction (Figure 1). In the apical view, during the isovolumic relaxation time (IVRT) healthy subjects showed slow, synchronous outward motion of the septum and the lateral wall with homogeneous color-encoding (blue/green, Figure 2). Analysis of peak velocities revealed low, negative velocities in both the septum and the lateral wall (Figure 3). In patients with a significant luminal narrowing of the LAD myocardial asynchrony was detected during the isovolumic relaxation period: while the septum was moving inwards (red color-encoding with low, positive velocities), the lateral wall was moving outwards (blue/green encoding, low, negative velocities). A representative example of a patient with CAD is given in Figure 4. The M-mode analysis of the abnormally contracting interventricular septum reveals positive peak tissue velocities during the isovolumic relaxation period (Figure 5). In hypertrophic cardiomyopathy, TDE was able to detect an abnormal inward motion of the interventricular septum during IVRT and a delay in the onset of rapid filling (Figure 6). Thus, tissue Doppler echocardiography is a feasible method for the on-line detection of myocardial asynchrony. Sensitivity and specificity of the findings have to be explored in further, prospectively randomized trials.

Cardiomyopathy, Hypertrophic↗
PubMed2000

Enhancement of radiotherapy by hyperthermia-regulated gene therapy.

PURPOSE: Interleukin 12 (IL-12) has shown strong antitumoral effects in numerous pre-clinical studies and appears to act synergistically with radiation in murine tumors. The major impediment to its clinical use has been its systemic toxicity. While using intratumorally injected viral gene therapy vectors encoding IL-12 reduces systemic side effects substantially, elevated systemic transgene levels are still observed because adenovirus can reach the circulation. Further restricting IL-12 expression in the tumor is therefore desirable in a combined radiation and adenovirus mediated cancer gene therapy regimen. METHODS AND MATERILAS: Hyperthermia-regulated gene therapy was tested in a nonimmunogenic B16.F10 melanoma line that is syngeneic with C57BL/6 mice. For hyperthermic gene therapy, an adenoviral vector coding for IL-12 under the control of the promoter of the human heat shock protein 70B (hsp70B) was used. One week after transplantation (at a 5-7 mm diameter), tumors were irradiated with 3 x 11 Gy (mo-we-fri). Adenovirus was injected at 3 x 10(8) pfu/tumor 24 h before the last radiation fraction or 3 days afterwards. Hyperthermia was performed 24 h later at 42.5 degrees C. Growth delay to reaching 3 times initial tumor volume was chosen as the biologic endpoint. IL-12 levels in tumor and serum were determined by using the enzyme-linked immunosorbant assay (ELISA). RESULTS: Adenovirus mediated intratumoral expression of IL-12 under the control of a heat inducible promoter in combination with hyperthermia is almost as effective as that under the control of a constitutive cytomegaly virus (CMV) promoter while systemic transgene levels are substantially reduced with the heat inducible promoter. The response to radiotherapy is improved considerably when combined with heat inducible gene therapy without apparent systemic toxicity. When used as a single dose, applying IL-12 gene therapy after completion of radiotherapy appears to be beneficial. CONCLUSIONS: Hyperthermia-regulated gene therapy in combination with radiation is feasible and therapeutically effective in murine tumors with no apparent systemic toxicity.

Adenoviridae↗
PubMed1997

The prospects for xenotransplantation of the kidney.

A severe shortage of transplant donors has led to a markedly prolonged waiting time for renal transplantation and has thus sparked interest in the use of animals in lieu of humans as a source of kidneys for transplantation. Clinical application of xenotransplantation is limited in large part by the severe immunologic reaction of the recipient against the graft. This immunologic reaction is mediated initially by components of natural immunity, such as xenoreactive antibodies, complement and natural killer cells, and later by elicited humoral and cellular immune responses that act in concert to disrupt the function of the endothelial lining of blood vessels. The past few years have brought considerable progress in elucidating the molecular and cellular basis of xenograft rejection and in developing strategies to overcome it.

Animals↗
PubMed1983

Does hydroxyurea inhibit DNA replication in mouse cells by more than one mechanism?

Cell-free DNA synthesis was performed in a lysed cell system from mouse cell cultures. The in vitro reaction was totally inhibited by N-ethylmaleimide but unaffected by hydroxyurea or fluorodeoxyuridine when these compounds were added to the incubation mixture. However, in a preparation obtained from cells which had been blocked by hydroxyurea before lysis, the rate of DNA synthesis was markedly reduced. This effect could not have been caused by the depletion of the precursor pools as all necessary triphosphates were added to the in vitro incubation mixture. Analysis by alkaline density gradients showed that the ligation of primary synthesis products is retarded in hydroxyurea-pretreated lysed cells and that small fragments accumulate. These results suggest that hydroxyurea interferes with the processing of early replication products, preventing the formation of longer intermediates. Its mechanism is either independent from the well-known inhibition of ribonucleoside diphosphate reductase or it may be the result of an as-yet-unknown function of this enzyme in a later step of replication. This observation could help to explain why cells appear to be blocked by hydroxyurea in the early part of the S phase (rather than at the G1/S border proper) and also why DNA repair synthesis is relatively insensitive to the drug.

Animals↗
PubMed2005

Changes in replication, nuclear location, and expression of the Igh locus after fusion of a pre-B cell line with a T cell line.

We have previously observed that replication and nuclear location of the murine Igh locus are developmentally regulated during B cell differentiation. In non-B, B, and plasma cells, sequences near the 3' end of the Igh locus replicate early in S while upstream Vh sequences replicate late in S, and the Igh locus is located near the nuclear periphery. In fact, in MEL non-B cells, replication of a 500-kb segment containing Igh-C and flanking sequences occurs progressively later throughout S by 3' to 5' unidirectional fork movement. In contrast, in pro- and pre-B cells, the entire 3-Mb Igh locus is located away from the nuclear periphery and replicates early in S by forks progressing in both directions. In this study, using an 18-81 (pre-B) x BW5147 (T) cell fusion system in which Igh expression is extinguished, we found that in all Igh alleles, Vh sequences replicated later in S than 3' Igh sequences (similar to that detected in BW5147), but the Igh locus was situated away from the nuclear periphery (similar to that observed in 18-81). Thus, pre-B cell-derived Igh genes had changes in replication timing, but not in nuclear location, whereas T cell-derived Igh genes changed their nuclear location but not their replication timing. These data are consistent with the silencing of a pre-B cell-specific replication program in the fusion hybrid cells and independent regulation of the nuclear location of Igh loci.

Animals↗
PubMed1997

Simulation of 3D-treatment plans in head and neck tumors aided by matching of digitally reconstructed radiographs (DRR) and on-line distortion corrected simulator images.

BACKGROUND AND PURPOSE: Simulation of 3D-treatment plans for head and neck malignancy is difficult due to complex anatomy. Therefore, CT-simulation and stereotactic techniques are becoming more common in the treatment preparation, overcoming the need for simulation. However, if simulation is still performed, it is an important step in the treatment preparation/execution chain, since simulation errors, if not detected immediately, can compromise the success of treatment. A recently developed PC-based system for on-line image matching and comparison of digitally reconstructed radiographs (DRR) and distortion corrected simulator monitor images that enables instant correction of field placement errors during the simulation process was evaluated. The range of field placement errors with non-computer aided simulation is reported. MATERIALS AND METHODS: For 14 patients either a primary 3D-treatment plan or a 3D-boost plan after initial treatment with opposing laterals for head and neck malignancy with a coplanar or non-coplanar two- or three-field technique was simulated. After determining the robustness of the matching process and the accuracy of field placement error detection with phantom measurements, DRRs were generated from the treatment planning CT-dataset of each patient and were interactively matched with on-line simulator images that had undergone correction for geometrical distortion, using a landmark algorithm. Translational field placement errors in all three planes as well as in-plane rotational errors were studied and were corrected immediately. RESULTS: The interactive matching process is very robust with a tolerance of <2 mm when suitable anatomical landmarks are chosen. The accuracy for detection of translational errors in phantom measurements was <1 mm and for in-plane rotational errors the accuracy had a maximum of only 1.5 degrees. For patient simulation, the mean absolute distance of the planned versus simulated isocenter was 6.4 +/- 3.9 mm. The in-plane rotational error in both planes was <3 degrees with one exception. Three large field placement errors (two patients with 11.5 and 16.0 mm distances of the planned versus simulated isocenter, respectively and one patient with a 7 degree rotational error) were detected and, as with the smaller errors, were immediately corrected. CONCLUSION: On-line image matching of treatment planning CT-derived DRRs and distortion corrected treatment simulator images is a precise and reliable method to reduce field placement errors in the simulation of complex 3D-treatment plans for head and neck malignancy and thus enhances accuracy in the first step of the treatment preparation/execution chain. However, out-of-plane rotational errors could not be assessed and assumedly they are comparatively small since due to rigid fixation, detected in-plane errors were small.

Computer Simulation↗
PubMed2003

Caspase-3 activation is an early event and initiates apoptotic damage in a human leukemia cell line.

Many apoptotic pathways culminate in the activation of caspase cascades usually triggered by the apical caspases-8 or -9. We describe a paradigm where apoptosis is initiated by the effector caspase-3. Diethylmaleate (DEM)-induced apoptotic damage in Jurkat cells was blocked by the anti-apoptotic protein Bcl-2, whereas, a peptide inhibitor of caspase-3 but not caspase-9 blocked DEM-induced mitochondrial damage. Isogenic Jurkat cell lines deficient for caspase-8 or the adaptor FADD (Fas associated death domain) were not protected from DEM-induced apoptosis. Caspase-3 activation preceded that of caspase-9 and initial processing of caspase-3 was regulated independent of caspase-9 and Bcl-2. However, inhibitors of caspase-9 or caspase-6 regulated caspase-3 later in the pathway. We explored the mechanism by which caspase-3 processing is regulated in this system. DEM triggered a loss of Erk-1/2 phosphorylation and XIAP (X-linked inhibitor of apoptosis protein) expression. The phorbol ester PMA activated a MEK-dependent pathway to block caspase-3 processing and cell death. Constitutively active MEK-1 (CA-MEK) upregulated XIAP expression and exogenous XIAP inhibited DEM-induced apoptotic damage. Thus, we describe a pathway where caspase-3 functions to initiate apoptotic damage and caspase-9 and caspase-6 amplify the apoptotic cascade. Further, we show that MEK may regulate caspase-3 activation via the regulation of XIAP expression in these cells.

Apoptosis↗
PubMed1995

Control of vascular cell adhesion molecule-1 gene promoter activity during neural differentiation.

Here we demonstrate that vascular cell adhesion molecule-1 (VCAM-1) is expressed in the developing central nervous system on neuroepithelial cells, which are the precursors of neurons and glia. As these cells differentiate, VCAM-1 is restricted to a subset of the glial population. An understanding of mechanisms responsible for this restricted pattern could provide insights into how lineage-specific gene expression is maintained during neural differentiation. As a model of neural differentiation, we turned to the P19 embryonic carcinoma cell line, which in response to retinoic acid will differentiate along a neural pathway. We show that VCAM-1 expression on the differentiating P19 cells resembles that in the central nervous system. Transfection of VCAM-1 gene promoter constructs into P19 cells revealed that the VCAM-1 gene is controlled sequentially by negative and positive elements during differentiation. We present evidence that early during differentiation, POU proteins block VCAM-1 gene activity; however, later in differentiation coincident with the appearance of VCAM-1 the pattern of POU proteins changes and the VCAM-1 gene promoter is activated. This activation is mediated through the NF kappa B/rel complex p50/p65, which forms during P19 cell differentiation.

Animals↗
PubMed2004

Regulated production of a peroxisome proliferator-activated receptor-gamma ligand during an early phase of adipocyte differentiation in 3T3-L1 adipocytes.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear hormone receptor that is critical for adipogenesis and insulin sensitivity. Ligands for PPARgamma include some polyunsaturated fatty acids and prostanoids and the synthetic high affinity antidiabetic agents thiazolidinediones. However, the identity of a biologically relevant endogenous PPARgamma ligand is unknown, and limited insight exists into the factors that may regulate production of endogenous PPARgamma ligands during adipocyte development. To address this question, we created a line of 3T3-L1 preadipocytes that carry a beta-galactosidase-based PPARgamma ligand-sensing vector system. In this system, induction of adipogenesis resulted in elevated beta-galactosidase activity that signifies activation of PPARgamma via its ligand-binding domain (LBD) and suggests generation and/or accumulation of a ligand moiety. The putative endogenous ligand appeared early in adipogenesis in response to increases in cAMP, accumulated in the medium, and dissipated later in adipogenesis. Organically extracted and high pressure liquid chromatography-fractionated conditioned media from differentiating cells, but not from mature adipocytes, were enriched in this activity. One or more components within the organic extract activated PPARgamma through interaction with its LBD, induced lipid accumulation in 3T3-L1 cells as efficiently as the differentiation mixture, and competed for binding of rosiglitazone to the LBD of PPARgamma. The active species appears to be different from other PPARgamma ligands identified previously. Our findings suggest that a novel biologically relevant PPARgamma ligand is transiently produced in 3T3-L1 cells during adipogenesis.

3T3-L1 Cells↗
PubMed1985

Anatomicomechanical study for the hydraulic line of a thermal left ventricular assist system.

A thermal left ventricular assist system currently under development consists of two separate major components, i.e., a pump/actuator module and an engine/thermal battery module. The possible implantation site of the engine/battery module is tentatively determined to be the iliac fossa, which requires a flexible interconnecting line to the pump/actuator module. A quantitative and biomechanical study was done on the effect of the implanted hydraulic line on the bendability of the torso. It revealed that the semirigid interconnecting line would not severely restrict the movement of the patient provided it has the proper prebend configuration. The cadaver fitting study proved the anatomical feasibility of the retroperitoneal iliac fossa as the implant site of the Thermal Ventricular Assist System 8 (TVAS 8) engine/battery module. The location and configuration of the interconnecting line of the TVAS 8 were determined using biomechanical analysis so that the restriction of the body movement due to the line could be minimized. The main route of the line was the left side of the trunk, and the line is W shaped in configuration. The line elongation is the most critical resistive factor and accordingly there may still be rigidity during lateral flexion.

Assisted Circulation↗
PubMed2004

Use of replication-conditional adenovirus as a helper system to enhance delivery of P450 prodrug-activation genes for cancer therapy.

Cytochrome P450 (CYP) gene transfer sensitizes tumor xenografts to anticancer prodrugs such as cyclophosphamide (CPA) without a detectable increase in host toxicity. Optimal prodrug activation is achieved when a suitable P450 gene (e.g., human CYP2B6) is delivered in combination with NADPH-cytochrome P450 reductase (P450R), which encodes the flavoenzyme P450 reductase. We sought to improve this gene therapy by coordinated delivery and expression of P450 and P450R on a single bicistronic vector using an internal ribosomal entry site (IRES) sequence. Retrovirus encoding a CYP2B6-IRES-P450R expression cassette was shown to induce strong P450-dependent CPA cytotoxicity in a population of infected 9L gliosarcoma cells. Adeno-P450, a replication-defective, E1/E3 region-deleted adenovirus engineered to express CYP2B6-IRES-P450R, induced intracellular CPA 4-hydroxylation, and CPA cytotoxicity, in a broad range of human cancer cell lines. However, limited Adeno-P450 gene transfer and CPA chemosensitization was seen with certain human tumor cells, notably PC-3 prostate and HT-29 colon cancer cells. Remarkable improvements could be obtained by coinfecting the tumor cells with Adeno-P450 in combination with Onyx-017, an E1b-55k gene-deleted adenovirus that selectively replicates in p53 pathway-deficient cells. Substantial increases in gene expression were observed during the early stages of viral infection, reflecting an apparent coamplification of the Adeno-P450 genome, followed by enhanced viral spread at later stages, as demonstrated in cultured tumor cells, and in A549 and PC-3 solid tumor xenografts grown in scid mice. This combination of the replication-defective Adeno-P450 with a replication-conditional and tumor cell-targeted helper adenovirus dramatically improved the low gene transfer observed with some human tumor cell lines and correspondingly increased tumor cell-catalyzed CPA 4-hydroxylation, CPA cytotoxicity, and in vivo antitumor activity in a PC-3 tumor xenograft model. The use of tumor-selective, replicating adenovirus to promote the spread of replication-defective gene therapy vectors, such as Adeno-P450, substantially increases the therapeutic potential of adenoviral delivery systems, and should lead to increased activity and enhanced tumor selectivity of cytochrome P450 and other gene-directed enzyme prodrug therapies.

Adenoviridae↗
PubMed2000

Fos induction in selective hypothalamic neuroendocrine and medullary nuclei by intravenous injection of urocortin and corticotropin-releasing factor in rats.

CRF and urocortin, administrated systemically, exert peripheral biological actions which may be mediated by brain pathways. We identified brain neuronal activation induced by intravenous (i.v.) injection of CRF and urocortin in conscious rats by monitoring Fos expression 60 min later. Both peptides (850 pmol/kg, i.v.) increased the number of Fos immunoreactive cells in the paraventricular nucleus of the hypothalamus, supraoptic nucleus, central amygdala, nucleus tractus solitarius and area postrema compared with vehicle injection. Urocortin induced a 4-fold increase in the number of Fos-positive cells in the supraoptic nucleus and a 3.4-fold increase in the lateral magnocellular part of the paraventricular nucleus compared with CRF. Urocortin also elicited Fos expression in the accessory hypothalamic neurosecretory nuclei, ependyma lining the ventricles and choroid plexus which was not observed after CRF. The intensity and pattern of the Fos response were dose-related (85, 255 and 850 pmol/kg, i.v.) and urocortin was more potent than CRF. Neither CRF nor urocortin induced Fos expression in the lateral septal nucleus, Edinger-Westphal nucleus, dorsal raphe nucleus, locus coeruleus, or hypoglossal nucleus. These results show that urocortin, and less potently CRF, injected into the circulation at picomolar doses activate selective brain nuclei involved in the modulation of autonomic/endocrine function; in addition, urocortin induces a distinct activation of hypothalamic neuroendocrine neurons.

Amygdala↗
PubMed2000

Developmental regulation of GDNF response and receptor expression in the enteric nervous system.

The development of the enteric nervous system is dependent upon the actions of glial cell line-derived neurotrophic factor (GDNF) on neural crest-derived precursor cells in the embryonic gut. GDNF treatment of cultured enteric precursor cells leads to an increase in the number of neurons that develop and/or survive. Here we demonstrate that, although GDNF promoted an increase in neuron number at all embryonic ages examined, there was a developmental shift from a mitogenic to a trophic response by the developing enteric neurons. The timing of this shift corresponded to developmental changes in gut expression of GFR alpha-1, a co-receptor in the GDNF-Ret signaling complex. GFR alpha-1 was broadly expressed in the gut at early developmental stages, at which times soluble GFR alpha-1 was released into the medium by cultured gut cells. At later times, GFR alpha-1 became restricted to neural crest-derived cells. GFR alpha-1 could participate in GDNF signaling when expressed in cis on the surface of enteric precursor cells, or as a soluble protein. The GDNF-mediated response was greater when cell surface, compared with soluble, GFR alpha-1 was present, with the maximal response seen the presence of both cis and trans forms of GFR alpha-1. In addition to contributing to GDNF signaling, cell-surface GFR alpha-1 modulated the specificity of interactions between GDNF and soluble GFR alphas. These experiments demonstrate that complex, developmentally regulated, signaling interactions contribute to the GDNF-dependent development of enteric neurons.

Animals↗
PubMed1975

Ontogeny of the pig hypothalamic neurosecretory system with particular reference to the distribution of neurophysin.

The immunoperoxidase cytochemical reaction was applied to the localization of neurophysin-containing elements in the fetal and adult pig hypothalamus. In the 60 day fetal pig, cells of the supraoptic nucleus (SON) were the only structues in the hypothalamus in which neurophysin was detected. However, by 87 days the cell bodies in both the SON and paraventricular nucleus (PVN) contained neurophysin-like material. The distribution of immunoreactive material in the 111 day fetal animal was similar to that found in the adult pig. In transverse section of the mature pig the SON exists in two discrete components; an antero-lateral group of cells connected by scattered cells to a smaller postero-medial group. Anteriorly, the PVN appears as a line of cells bordering the third ventricle but as we proceed posteriorly the dorsal aspect expands laterally to give a wedge-shaped group of cells. In mid-sagittal sections, the cells of the PVN are distributed over a wide area of the anterior hypothalamus in a triangular profile. The borders between the SON and PVN became more difficult to define in medial sections than in lateral sections. Continuous gradient polyacrylamide gel electrophoresis was carried out on the neural lobe extracts from fetal, newborn and adult pigs. Proteins with an electrophoretic mobility similar to that of porcine neurophysins-I, -II and -III were present in the newborn and 98 day fetal pig. It is concluded that material immunoreactive with anti-neurophysin serum is present in the hypothalamus of the 60 day fetal pig. Furthermore, at late fetal development and during the postnatal period it is tentatively suggested that the neurophysin present in the pituitaries of these animals is chemically identical with that of adult neurophysin.

Animals↗
PubMed1995

Zebrafish neurons express two L1-related molecules during early axonogenesis.

Partial clones coding for two L1-related genes, zebrafish L1.1 and L1.2, were isolated from a zebrafish embryonic cDNA library. The homology analysis, based on the deduced amino acid sequences of L1.1 and L1.2, revealed that the two molecules are most closely related to each other and to mouse L1. Analysis by in situ hybridization revealed that during embryonic development of the nervous system the L1.1 and L1.2 messages are restricted to postmitotic neurons and that the onset of expression correlates with the initiation of axonogenesis. L1.1 is expressed by all known classes of neurons, consistent with an important general function during axonal outgrowth. Most of the neurons also express L1.2. However, L1.2 either is undetectable or is expressed at very low levels in the neurons of the olfactory placodes, anterior lateral line/acoustic ganglia complex, posterior lateral line ganglion, and in late developing hindbrain neurons. In the spinal cord, L1.2 message is detected only in a subpopulation of Rohon-Beard cells. This suggests the possibility that different levels of L1.2 expression may serve to distinguish different populations of neurons and their axons.

Animals↗
PubMed1980

The ultrastructure and vascular supply of the different fibre types in the axial muscle of the sturgeon Acipenser stellatus, Pallas.

The ultrastructure and vascular supply of the different fibre types in the lateral muscles of the sturgeon Acipenser stellatus were studied by light- and electron microscopy and morphometry. Three fibre types form separate layers without intermingling. The red fibres are superficial, the white fibres deep and the intermediate fibres between them. From morphometric analyses, the mitochondrial volume fraction in red fibres is 30%, in intermediate fibres 3.7% and in white fibres 0.7%. Z lines are most fuzzy in the red fibres. Triads of the sarcotubular system are always situated at the level of the Z discs. In red fibres the three elements are arranged in a series along the myofibrils, whereas in white fibres they are arranged transversely and in the intermediate fibres they are aligned obliquely. The number of capillaries surrounding each fibre is 2.3, 0.9 and 0.2 for the red, intermediate and white fibres, respectively. In red fibres 16% of the surface is directly covered by capillaries. The corresponding percentages for intermediate and white fibres are 5 and 1, respectively. Per unit volume of the fibre, the directly vascularised fibre surface in red fibres is about ten times larger than that of white fibres. The degree of vascularisation of the fibre types is directly related to the volume fraction of mitochondria, and thus to their aerobic capacities.

Animals↗
PubMed2006

Validation of a computer analysis to determine 3-D rotations and translations of the rib cage in upright posture from three 2-D digital images.

Since thoracic cage posture affects lumbar spine coupling and loads on the spinal tissues and extremities, a scientific analysis of upright posture is needed. Common posture analyzers measure human posture as displacements from a plumb line, while the PosturePrint claims to measure head, rib cage, and pelvic postures as rotations and translations. In this study, it was decided to evaluate the validity of the PosturePrint Internet computer system's analysis of thoracic cage postures. In a university biomechanics laboratory, photographs of a mannequin thoracic cage were obtained in different postures on a stand in front of a digital camera. For each mannequin posture, three photographs were obtained (left lateral, right lateral, and AP). The mannequin thoracic cage was placed in 68 different single and combined postures (requiring 204 photographs) in five degrees of freedom: lateral translation (Tx), lateral flexion (Rz), axial rotation (Ry), flexion-extension (Rx), and anterior-posterior translation (Tz). The PosturePrint system requires 13 reflective markers to be placed on the subject (mannequin) during photography and 16 additional "click-on" markers via computer mouse before a set of three photographs is analyzed by the PosturePrint computer system over the Internet. Errors were the differences between the positioned mannequin and the calculated positions from the computer system. Average absolute value errors were obtained by comparing the exact inputted posture to the PosturePrint computed values. Mean and standard deviation of computational errors for sagittal displacements of the thoracic cage were Rx=0.3+/-0.1 degrees , Tz=1.6+/-0.7 mm, and for frontal view displacements were Ry=1.2+/-1.0 degrees , Rz=0.6+/-0.4 degrees , and Tx=1.5+/-0.6 mm. The PosturePrint system is sufficiently accurate in measuring thoracic cage postures in five degrees of freedom on a mannequin indicating the need for a further study on human subjects.

Biomechanical Phenomena↗