Morphology

Source: www.ncbi.nlm.nih.gov --- 4 days ago
Corneal biomechanics, thickness and optic disc Morphology in children with optic disc tilt. Br J Ophthalmol. 2008 Aug 14; Authors: Lim LS, Gazzard G, Chan YH, Fong A, Kotecha A, Sim E, Tan D, Tong L, Saw SM AIMS: To determine the associations between corneal biomechanical parameters as measured by the Reichert Ocular Response Analyzer (ORA) and disc Morphology and retinal nerve fiber layer thickness (RNFL) measured by the Heidelberg Retinal Tomograph (HRT) II in Singaporean children. METHODS: This is a cross-sectional study conducted on a subset of children enrolled in the Singapore Cohort Study of the Risk Factors of Myopia (SCORM). Corneal hysteresis (CH), corneal resistance factor (CRF) and central corneal thickness (CCT) were measured with the ORA. Optic disc Morphology and RNFL thickness were assessed by the HRT II. Cycloplegic refraction and ultrasound A-scans were also performed and disc tilt was assayed from stereo photographs. RESULTS: 102 subjects (mean age 12.01+/- 0.57 years; range 11 - 14yrs) were included in the study. The mean CH was 12.00 +/- 1.40mmHg, the mean CRF was 11.99 +/- 1.65mmHg and the mean CCT was 581.12 +/- 33.53microm. Eyes with tilted discs had significantly longer axial lengths and more myopic refraction than eyes without tilted discs. There were no significant correlations between CH, CRF or CCT and the HRT II parameters, after the application of the Bonferroni correction. When stratified for disc tilt h ...

Source: www.ncbi.nlm.nih.gov --- 3 days ago
Effects of the Brain-Derived Neurotrophic Growth Factor Val66Met Variation on Hippocampus Morphology in Bipolar Disorder. Neuropsychopharmacology. 2008 Aug 13; Authors: Chepenik LG, Fredericks C, Papademetris X, Spencer L, Lacadie C, Wang F, Pittman B, Duncan JS, Staib LH, Duman RS, Gelernter J, Blumberg HP Histological and behavioral research in bipolar disorder (BD) implicates structural abnormalities in the hippocampus. Brain-derived neurotrophic growth factor (BDNF) protein is associated with hippocampal development and plasticity, and in mood disorder pathophysiology. We tested the hypotheses that both the BDNF val66met polymorphism and BD diagnosis are associated with decreased hippocampus volume, and that individuals with BD who carry the met allele have the smallest hippocampus volumes compared to individuals without BD and val/val homozygotes. We further explored localization of morphological differences within hippocampus in BD associated with the met allele. Twenty individuals with BD and 18 healthy comparison (HC) subjects participated in high-resolution magnetic resonance imaging scans from which hippocampus volumes were defined and measured. We used linear mixed model analysis to study effects of diagnosis and BDNF genotype on hippocampus volumes. We then employed three-dimensional mapping to localize areas of change within the hippocampus associated with the BDNF met allele in BD. We found that hippocampus volumes were s ...

Source: www.ncbi.nlm.nih.gov --- 9 days ago
Related Articles [Sperm Morphology does not influence fertilization rate in vitro] Zhonghua Nan Ke Xue. 2008 Jul;14(7):610-3 Authors: Wu Y, Xu HM, Zhang SY, Xu WH, Tang F, Yang LH OBJECTIVE: To determine the correlation of the rate of morphologically normal sperm, sperm head defect, teratozoosperm index (TZI) and sperm deformity index (SDI) with the fertilization outcome of IVF and intracytoplasmic sperm injection (ICSI). METHODS: We detected normal sperm Morphology, sperm head defect, TZI and SDI by Krüger's strict criteria and compared them with the rate of fertilization. RESULTS: In either IVF or ICSI, the fertilization rate did not show any correlation with the normal sperm Morphology rate, the head defect rate, TZI and SDI, nor any statistic differences were found in the rates of fertilization, clinical pregnancy and quality embryos either between the SDI > 1.6 and the SDI < 1.6 groups (P > 0.05) or between the normal sperm Morphology rate > 15% and < 15% groups (P > 0.05). CONCLUSION: Sperm Morphology has no predictive value for the rate of fertilization in vitro. PMID: 18686381 [PubMed - in process] ...

Source: www.ncbi.nlm.nih.gov --- 14 days ago
Related Articles High molecular weight tropomyosins regulate osteoclast cytoskeletal Morphology. Bone. 2008 Jul 12; Authors: Kotadiya P, McMichael BK, Lee BS Tropomyosins are coiled-coil dimers that bind to the major groove of F-actin and regulate its accessibility to actin-modifying proteins. Although approximately 40 tropomyosin isoforms have been identified in mammals, they can broadly be classified into two groups based on protein size, that is, high molecular weight and low molecular weight isoforms. Osteoclasts, which undergo rounds of polarization and depolarization as they progress through the resorptive cycle, possess an unusual and highly dynamic actin cytoskeleton. To further define some of the actin regulatory proteins involved in osteoclast activity, we previously performed a survey of tropomyosin isoforms in resting and resorbing osteoclasts. Osteoclasts were found to express two closely related tropomyosins of the high molecular weight type, which are not expressed in monocytic and macrophage precursors. These isoforms, Tm-2 and Tm-3, are not strongly associated with actin-rich adhesion structures, but are instead distributed diffusely throughout the cell. In this study, we found that Tm-2/3 expression occurs late in osteoclastogenesis and continues to increase as cells mature. Knockdown of these isoforms via RNA interference results in flattening and increased spreading of osteoclasts, accompanied by diminished motility ...

Source: www.ncbi.nlm.nih.gov --- 4 days ago
Effects of cryopreservation on sperm parameters and ultrastructural Morphology of human spermatozoa. J Assist Reprod Genet. 2008 Aug 13; Authors: Ozkavukcu S, Erdemli E, Isik A, Oztuna D, Karahuseyinoglu S PURPOSE: Cryopreservation of sperm is a widely used technique to maintain and protect the fertility in various occasions such as infertility and malignancy treatments. This study aims to reveal the effects of freezing and thawing on human spermatozoa. MATERIALS AND METHODS: To evaluate the effects of freeze-thawing, semen samples were evaluated by light microscopy by means of Morphology, motility and viability, by scanning and transmission electron microscopy for detailed ultrastructural changes. RESULTS: After cryopreservation, a significant decrease in spermatozoa viability was observed (p < 0.01). Group a, b and c motility according to World Health Organization criteria decreased considerably (p < 0.05, p < 0.01, p < 0.05, respectively), whereas there was a substantial increase in group d motility. A strong correlation between rise in number of immotile spermatozoa and decrease in viability was also noted (r = -0.848, p < 0.01). Post-thaw light microscopic studies revealed a considerable decrease in rate of normal spermatozoa (p < 0.05). A considerable decline in the rate of normal sperm was also observed by TEM (p < 0.05). Statistically, acrosomal changes and subacrosomal swelling were found to be significantly increased (both p ...

Source: www.ncbi.nlm.nih.gov --- 1 day ago
Related Articles Morphology of Glomerular Hematuria Is Reproduced in vitro by Carbonyl Stress. Nephron Exp Nephrol. 2008 Aug 18;110(1):e25-e30 Authors: Degrell P, Wagner Z, Szijarto IA, Wagner L, Marko L, Mohas M, Cseh J, Wittmann I Background: In glomerulonephritides, dysmorphic red blood cells (RBCs) with membrane blebs can be found in the urine; this is referred to as glomerular hematuria. Glomerulonephritides are characterized by increased carbonyl stress and elevated methylglyoxal (MGO) levels. MGO causes oxidative stress and intracellular calcium accumulation. In the present study, we investigated whether the effect of MGO-induced calcium accumulation in RBCs develops through increased oxidative stress. Furthermore, we studied whether MGO can lead to RBC membrane blebbing. Methods: RBC suspensions from healthy volunteers were incubated with different concentrations of MGO at 37 degrees C. We measured oxidative stress and intracellular calcium level using fluorescent indicators. We determined the frequency of dysmorphic RBCs, and also performed scanning electron microscopy. Results: MGO increased oxidative stress and caused accumulation of calcium in isolated RBCs. These effects could be prevented using antioxidants. In the presence of MGO, RBC membrane blebbing developed. Conclusion: According to our findings, MGO causes calcium accumulation through oxidative stress. Carbonyl and oxidative stress may play an important role in th ...

Source: www.ncbi.nlm.nih.gov --- 1 day ago
Related Articles Deciphering cellular Morphology and biocompatibility using polymer microarrays. Biomed Mater. 2008 Aug 15;3(3):34112 Authors: Pernagallo S, Unciti-Broceta A, Díaz-Mochón JJ, Bradley M A quantitative and qualitative analysis of cellular adhesion, Morphology and viability is essential in understanding and designing biomaterials such as those involved in implant surfaces or as tissue-engineering scaffolds. As a means to simultaneously perform these studies in a high-throughput (HT) manner, we report a normalized protocol which allows the rapid analysis of a large number of potential cell binding substrates using polymer microarrays and high-content fluorescence microscopy. The method was successfully applied to the discovery of optimal polymer substrates from a 214-member polyurethane library with mouse fibroblast cells (L929), as well as simultaneous evaluation of cell viability and cellular Morphology. Analysis demonstrated high biocompatibility of the binding polymers and permitted the identification of several different cellular morphologies, showing that specific polymer interactions may provoke changes in cell shape. In addition, SAR studies showed a clear correspondence between cellular adhesion and polymer structure. The approach can be utilized to perform multiple experiments (up to 1024 single experiments per slide) in a highly reproducible manner, leading to the generation of vast amounts of data in a short ti ...

Source: www.ncbi.nlm.nih.gov --- 19 hours ago
Related Articles Influence of Vascular Endothelial Growth Factor Variation on Human Hippocampus Morphology. Biol Psychiatry. 2008 Aug 14; Authors: Blumberg HP, Wang F, Chepenik LG, Kalmar JH, Edmiston E, Duman RS, Gelernter J BACKGROUND: Morphological abnormalities in hippocampus have been implicated in neuropsychiatric disorders, including depression, schizophrenia, and dementia. Vascular endothelial growth factor (VEGF) has been demonstrated to have neurogenic effects in the hippocampus in rats. However, influence of VEGF variation on hippocampus Morphology in humans has yet to be shown. Here, an integrated genetic and neuroimaging approach was used to investigate whether VEGF variation influences hippocampus Morphology in humans. METHODS: High-resolution magnetic resonance imaging and voxel-based morphometry were used to identify the influence of genetic variation of VEGFA [rs833068 (SNP-1), rs833070 (SNP-2), rs2146323 (SNP-3) and rs3025020 (SNP-4)] on brain Morphology in 47 healthy individuals. RESULTS: Variation in VEGFA SNP-2 and SNP-3 showed significant effects on hippocampus concentration. CONCLUSIONS: The findings suggest that effects of VEGF in hippocampus found in rats extend to humans; further understanding of effects of VEGFA variation might have important implications in identifying individuals more vulnerable to hippocampus pathology as well as those neuropsychiatric populations most likely to benefit from VEGF-mediated ...

Source: www.ncbi.nlm.nih.gov --- 20 days ago
Related Articles H-1152 effects on intraocular pressure and trabecular meshwork Morphology of rat eyes. J Ocul Pharmacol Ther. 2008 Aug;24(4):373-9 Authors: Yu M, Chen X, Wang N, Cai S, Li N, Qiu J, Brandt CR, Kaufman PL, Liu X PURPOSE: The aim of this study was to elucidate the effects of the Rho-kinase inhibitor, H-1152, on cultured human trabecular meshwork (HTM) cells, TM Morphology, and intraocular pressure (IOP) in rats. METHODS: Cultured HTM cells were treated with H-1152. Changes in cell Morphology and the organization of the actin cytoskeleton and focal adhesions were evaluated by microscopy and immunofluorescence. H-1152 was administered topically to the eyes of conscious rats, and IOP was measured with a commercially available tonometer before and after treatment. The eyes were enucleated 1 h after treatment, fixed, and processed for morphologic analysis by light and electron microscopy. RESULTS: Exposure of the cultured HTM cells to 20 microM of H-1152 induced elongation and separation of cells, deterioration, and loss of actin stress fibers and focal adhesions within 2 h. Topical administration of H-1152 resulted in a significant decrease in IOP from 0.5 to 6 h, with the maximum IOP reduction of 28.1% at 1 h post-treatment (P < 0.001; n = 10). H-1152 caused an expansion of the intercellular spaces and loss of extracellular material in the juxtacanalicular region of the TM in rat eyes. CONCLUSIONS: The IOP-lowering effect o ...

Source: www.moreover.com --- 32 days ago
The Liujiang cranium is the most complete and well-preserved late Pleistocene human fossils ever unearthed in South China. ...

Source: www.ncbi.nlm.nih.gov --- 47 days ago
Related Articles Peculiar Morphology of stones in primary hyperoxaluria. N Engl J Med. 2008 Jul 3;359(1):100-2 Authors: Daudon M, Jungers P, Bazin D PMID: 18596285 [PubMed - in process] ...

Source: www.ncbi.nlm.nih.gov --- 31 days ago
Effect of agitation intensities on fungal Morphology of submerged fermentation. Biotechnol Bioeng. 1997 Sep 5;55(5):715-26 Authors: Cui YQ, van der Lans RG, Luyben KC Both parallel fermentations with Aspergillus awamori (CBS 115.52) and a literature study on several fungi have been carried out to determine a relation between fungal Morphology and agitation intensity. The studied parameters include hyphal length, pellet size, surface structure or so-called hairy length of pellets, and dry mass per-wet-pellet volume at different specific energy dissipation rates. The literature data from different strains, different fermenters, and different cultivation conditions can be summarized to say that the main mean hyphal length is proportional to the specific energy dissipation rate according to a power function with an exponent of -0.25 +/- 0.08. Fermentations with identical inocula showed that pellet size was also a function of the specific energy dissipation rate and proportional to the specific energy dissipation rate to an exponent of -0.16 +/- 0.03. Based on the experimental observations, we propose the following mechanism of pellet damage during submerged cultivation in stirred fermenters. Interaction between mechanical forces and pellets results in the hyphal chip-off from the pellet outer zone instead of the breakup of pellets. By this mechanism, the extension of the hyphae or hair from pellets is restricted so that the size of pellets ...

Source: www.ncbi.nlm.nih.gov --- 39 days ago
Related Articles Corpus callosum Morphology in children and adolescents with attention deficit hyperactivity disorder: a meta-analytic review. Neuropsychology. 2008 May;22(3):341-9 Authors: Hutchinson AD, Mathias JL, Banich MT Several studies have examined corpus callosum (CC) Morphology in children and adolescents with attention deficit hyperactivity disorder (ADHD). A meta-analysis of atypical brain Morphology in children and adolescents with ADHD by Valera, Faraone, Murray, and Seidman (2006) reported a reduction in the splenium of the CC in this group compared with healthy controls. This meta-analysis undertook a more detailed examination of callosal Morphology by also considering comorbid conditions and gender differences. The data from 13 studies were analyzed. Consistent with Valera et al. (2006), the splenium was smaller in children and adolescents with ADHD than in healthy controls. However, this result appears to be the result of a smaller splenium in females with ADHD. In addition, boys exhibited a smaller rostral body. There were no significant differences in CC measurements of studies that included ADHD samples with comorbid conditions. However, comorbidities were not consistently reported, making it difficult to accurately evaluate the impact of comorbidity on CC size. Additional research is needed to investigate whether gender differences reflect different ADHD subtypes. In addition, it is not known if these CC differen ...

Source: www.ncbi.nlm.nih.gov --- 48 days ago
Living Cell Functions and Morphology Revealed by Two-Photon Microscopy in Intact Neural and Secretory Organs. Mol Cells. 2008 Jun 26;26(2) Authors: Nemoto T Laser light microscopy enables observation of various simultaneously occurring events in living cells. This capability is important for monitoring the spatiotemporal patterns of the molecular interactions underlying such events. Two-photon excited fluorescence microscopy (two-photon microscopy), a technology based on multiphoton excitation, is one of the most promising candidates for such imaging. The advantages of two-photon microscopy have spurred wider adoption of the method, especially in neurological studies. Multicolor excitation capability, one advantage of two-photon microscopy, has enabled the quantification of spatiotemporal patterns of [Ca(2+)]i and single episodes of fusion pore openings during exocytosis. In pancreatic acinar cells, we have successfully demonstrated the existence of "sequential compound exocytosis" for the first time, a process which has subsequently been identified in a wide variety of secretory cells including exocrine, endocrine and blood cells. Our newly developed method, the two-photon extracellular polar-tracer imaging-based quantification (TEPIQ) method, can be used for determining fusion pores and the diameters of vesicles smaller than the diffraction-limited resolution. Furthermore, two-photon microscopy has the demonstrated capability of obta ...

Source: www.ncbi.nlm.nih.gov --- 25 days ago
Related Articles Designing tailored biomaterial surfaces to direct keratinocyte Morphology, attachment, and differentiation. J Biomed Mater Res A. 2008 Jul 24; Authors: Bush KA, Driscoll PF, Soto ER, Lambert CR, McGimpsey WG, Pins GD Precisely engineering the surface chemistry of biomaterials to modulate the adsorption and functionality of biochemical signaling molecules that direct cellular functions is critical in the development of tissue engineered scaffolds. Specifically, this study describes the use of functionalized self-assembled monolayers (SAMs) as a model system to assess the effects of biomaterial surface properties on controlling fibronectin (FN) conformation and concentration as well as keratinocyte function. By systematically analyzing FN adsorption at low and saturated surface densities, we distinguished between SAM-dependent effects of FN concentration and conformation on presenting cellular binding domains that direct cellular functions. Quantitative image analyses of immunostained samples showed that modulating the availability of the FN synergy site directly correlated with changes in keratinocyte attachment, spreading, and differentiation, through integrin-mediated signaling mechanisms. The results of this study will be used to elucidate design features that can be incorporated into dermal equivalents and percutaneous implants to enhance the rate of re-epithelialization and tissue regeneration. Furthermore, these f ...

Source: pubs.nrc-cnrc.gc.ca --- 22 days ago
Tyler W. Smith and Marcia J. Waterway We used a combination of Morphology, amplified fragment length polymorphisms (AFLP), and restriction-site data from 252 individuals from 51 populations to investigate species limits and... ...

Source: www.library.ualberta.ca --- 30 days ago
Tunbridge Wells, UK : Anshan ; New Delhi : Jaypee Brothers Medical Publishers, c2008. QM 602 P48 2008 QM 602 P48 2008 (ON SHELF) ...