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Maturation Index (maturation + index)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	33%

Selected Abstracts

Covalently-linked hyaluronan promotes bone formation around Ti implants in a rabbit model

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2009
Marco Morra
Abstract The goal of this study was the in vivo evaluation of nanoporous titanium (Ti) implants bearing a covalently linked surface hyaluronan (HA) layer. Implant surface topography and surface chemistry were previously evaluated by scanning electron micorscopy and X-ray photoelectron spectroscopy. Results showed that the surface modification process did not affect surface topography, yielding a homogeneously HA-coated nanotextured implant surface. In vivo evaluation of implants in both cortical and trabecular bone of rabbit femurs showed a significant improvement of both bone-to-implant contact and bone ingrowth at HA-bearing implant interfaces at 4 weeks. The improvement in osteointegration rate was particularly evident in the marrow-rich trabecular bone (bone-to-implant contact: control 22.5%; HA-coated 69.0%, p,<,0.01). Mechanical testing (push-out test) and evaluation of interfacial bone microhardness confirmed a faster bone maturation around HA-coated implants (Bone Maturation Index: control 79.1%; HA-coated 90.6%, p,<,0.05). Suggestions based on the biochemical role of HA are presented to account for the observed behavior. Published by Wiley Periodicals, Inc. J Orthop Res 27: 657,663, 2009 [source]

The role of angiogenesis, vascular maturation, regression and stroma infiltration in dormancy and growth of implanted MLS ovarian carcinoma spheroids

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2004
Assaf Gilead
Abstract MLS ovarian epithelial carcinoma multicellular spheroids xenografted subcutaneously in CD-1 nude mice displayed growth delay, or dormancy, of up to 52 days. In the study reported here, implanted MLS spheroids were used for testing the role of angiogenesis and vascular maturation in triggering the initiation of tumor progression. The kinetics and impact of neovascular maturation and functionality, in dormancy, and growth of MLS spheroid xenografts were studied noninvasively by BOLD contrast MRI. MR data were supported by histologic staining for biotinylated albumin as a blood pool marker and alpha-smooth muscle actin (alpha-SMA) as marker for perivascular mural cells. Although the tumor periphery showed higher levels of total and mature vasculature than normal skin, the fraction of mature out of the total vessels as detected by MRI vascular maturation index (VMIMRI) was significantly lower in the tumor both before and after tumor exit from dormancy. The neovasculature induced by the implanted spheroid was unstable and showed cycles of vessel growth and regression. Surprisingly, this instability was not restricted to the immature vessels, but rather included also regression of mature vessels. During dormancy, neovasculature was predominantly peripheral with no infiltration into the implanted spheroid. Infiltration of alpha-SMA positive stroma cells into the spheroid was associated with functional vascularization and tumor growth. Thus, stroma infiltration and vascular maturation are an important checkpoint linking the angiogenic switch with initiation of tumor progression. © 2003 Wiley-Liss, Inc. [source]

Visual deprivation increases accumulation of dense core vesicles in developing optic tectal synapses in Xenopus laevis

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 12 2010
Jianli Li
Abstract Despite considerable progress in understanding the molecular components of synapses in the central nervous system, the ultrastructural rearrangements underlying synaptic development remain unclear. We used serial section transmission electron microscopy and three-dimensional reconstructions of the optic tectal neuropil of Xenopus laevis tadpoles to detect and quantify changes in synaptic ultrastructure over a 1-week period from stages 39 and 47, during which time the visual system of Xenopus tadpoles becomes functional. Synapse density, presynaptic maturation index, and number of synapses per axon bouton increase, whereas the number of DCVs per bouton decreases, between stages 39 and 47. The width of the synaptic cleft decreased and the diameter of postsynaptic profiles increased between stages 39 and 47 and then remained relatively unchanged after stage 47. We found no significant difference in synapse maturation between GABAergic and non-GABAergic synapses. To test the effect of visual experience on synaptogenesis, animals were deprived of visual experience for 3 days from stage 42 to 47. Visual deprivation decreased synapse maturation and the number of connections per bouton. Furthermore, visual deprivation increased the number of DCVs per bouton by more than twofold. The visual-deprivation-induced decrease in synaptic connections is specific to asymmetric non-GABAergic synapses; however, both symmetric GABAergic and asymmetric synapses show comparable increases in the number DCVs with visual deprivation. In both the control and the visually deprived animals, the number of DCVs per bouton is highly variable and does not correlate with either synapse maturation or the number of connected partners per bouton. These data suggest that synaptogenesis and DCV accumulation are regulated by visual experience and further suggest a complex spatial and temporal relation between DCV accumulation and synapse formation. J. Comp. Neurol. 518:2365,2381, 2010. © 2010 Wiley-Liss, Inc. [source]

ORIGINAL RESEARCH,ENDOCRINOLOGY: A Comparative Study of the Effects of Local Estrogen With or Without Local Testosterone on Vulvovaginal and Sexual Dysfunction in Postmenopausal Women

THE JOURNAL OF SEXUAL MEDICINE, Issue 3 2010
Chitra Raghunandan MD
ABSTRACT Introduction., A significant number of postmenopausal women suffer from distressing problems because of urogenital atrophy secondary to the decline in circulating estrogen levels. Treatment with topical hormones may provide relief in such women when used judiciously. Aim., To study the effects of local estrogen with or without local testosterone on urogenital and sexual health in postmenopausal women. Methods., Seventy-five postmenopausal women symptomatic for urogenital atrophy and sexual dysfunction were randomly divided into two study groups and one control group. The women in study group 1 received local estrogen cream; study group 2 received local estrogen and testosterone cream; the control group received nonhormonal lubricant KY gel for 12 weeks. The urogenital and sexuality score, along with the vaginal health index and the vaginal maturation index (VMI), was calculated at the beginning of therapy and 12 weeks later. Main Outcome Measures., Changes in the urogenital and sexuality score along with vaginal health index and VMI. Results., After 12 weeks of therapy, there was a significant improvement in all the four study parameters, which correlated well with the improvement in symptoms of urogenital atrophy and sexual dysfunction in both the study groups as compared with the control group. Improvement in sexuality score was greatest with combined estrogen,androgen therapy. There were no adverse effects and the therapies were well accepted without any compliance issue. Conclusion., Local estrogen either alone or with androgen is highly effective in relieving symptoms of urogenital atrophy and in improving sexual function in symptomatic postmenopausal women. Raghunandan C, Agrawal S, Dubey P, Choudhury M, and Jain A. A comparative study of the effects of local estrogen with or without local testosterone on vulvovaginal and sexual dysfunction in postmenopausal women. J Sex Med 2010;7:1284,1290. [source]

ORIGINAL RESEARCH,BASIC SCIENCE: A Prospective Study Examining the Anatomic Distribution of Nerve Density in the Human Vagina

THE JOURNAL OF SEXUAL MEDICINE, Issue 6 2006
Rachel Pauls MD
ABSTRACT Introduction., Women possess sufficient vaginal innervation such that tactile stimulation of the vagina can lead to orgasm. However, there are few anatomic studies that have characterized the distribution of nerves throughout the human vagina. Aim., The aim of this prospective study was to better characterize the anatomic distribution of nerves in the adult human vagina. A secondary aim was to assess whether vaginal innervation correlates with the subject's demographic information and sexual function. Methods., Full-thickness biopsies of anterior and posterior vagina (proximal and distal), cuff, and cervix were taken during surgery in a standardized manner. Specimens were prepared with hematoxylin and eosin, and S100 protein immunoperoxidase. The total number of nerves in each specimen was quantified. Enrolled patients completed a validated sexual function questionnaire (Female Sexual Function Index, FSFI) preoperatively. Main Outcome Measures., A description of vaginal innervation by location and an assessment of vaginal innervation in association with the subject's demographic information and sexual function. Results., Twenty-one patients completed this study, yielding 110 biopsy specimens. Vaginal innervation was somewhat regular, with no site consistently demonstrating the highest nerve density. Nerves were located throughout the vagina, including apex and cervix. No significant differences were noted in vaginal innervation based on various demographic factors, including age, vaginal maturation index, stage of prolapse, number of vaginal deliveries, or previous hysterectomy. There were no correlations between vaginal nerve quantity and FSFI domain and overall scores. Fifty-seven percent of the subjects had female sexual dysfunction; when compared to those without dysfunction, there were no significant differences in total or site-specific nerves. Conclusions., In a prospective study, vaginal nerves were located regularly throughout the anterior and posterior vagina, proximally and distally, including apex and cervix. There was no vaginal location with increased nerve density. Vaginal innervation was not associated with demographic information or sexual function. Pauls R, Mutema G, Segal J, Silva WA, Kleeman S, Dryfhout V, and Karram M. A prospective study examining the anatomic distribution of nerve density in the human vagina. J Sex Med 2006;3:979,987. [source]

SYNTHESIS: Life history change in commercially exploited fish stocks: an analysis of trends across studies

EVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 3 2009
Diana M. T. Sharpe
Abstract Age and size at maturation have declined dramatically in many commercial fish stocks over the past few decades , changes that have been widely attributed to fishing pressure. We performed an analysis of such trends across multiple studies, to test for the consistency of life history changes under fishing, and for their association with the intensity of exploitation (fishing mortality rate). We analyzed 143 time series from 37 commercial fish stocks, the majority of which originated from the North Atlantic. Rates of phenotypic change were calculated for two traditional maturation indices (length and age at 50% maturity), as well as for probabilistic maturation reaction norms (PMRNs). We found that all three indices declined in heavily exploited populations, and at a rate that was strongly correlated with the intensity of fishing (for length at 50% maturity and PMRNs). These results support previous assertions that fishing pressure is playing a major role in the life history changes observed in commercial fish stocks. Rates of change were as strong for PMRNs as for age and size at 50% maturity, which is consistent with the hypothesis that fishing-induced phenotypic changes can sometimes have a genetic basis. [source]