969 resultados para Steven Moll
Resumo:
Previous studies have suggested that abnormal corneal wound healing in patients after photorefractive keratectomy (PRK) is associated with the appearance of myofibroblasts in the stroma between two and four weeks after surgery. The purpose of this study was to examine potential myofibroblast progenitor cells that might express other filament markers prior to completion of the differentiation pathway that yields alpha-smooth muscle actin (SMA)-expressing myofibroblasts associated with haze localized beneath the epithelial basement membrane after PRK. Twenty-four female rabbits that had -9 diopter PRK were sacrificed at 1 week, 2 weeks, 3 weeks or 4 weeks after surgery. Corneal rims were collected, frozen at -80 degrees C, and analyzed by immunocytochemistry using anti-vimentin, anti-desmin, and anti-SMA antibodies. Double immunostaining was performed for the co-localization of SMA with vimentin or desmin with SMA. An increase in vimentin expression in stromal cells is noted as early as 1 week after PRK in the rabbit cornea. As the healing response continues at two or three weeks after surgery, many stromal cells expressing vimentin also begin to express desmin and SMA. By 4 weeks after the surgery most, if not all, myofibroblasts express vimentin, desmin and SMA. Generalized least squares regression analysis showed that there was strong evidence that each of the marker groups differed in expression over time compared to the other two (p < 0.01). Intermediate filaments - vimentin and desmin co-exist in myofibroblasts along with SMA and may play an important role in corneal remodeling after photorefractive keratectomy. The earliest precursors of myofibroblasts destined to express SMA and desmin are detectible by staining for vimentin at 1 week after surgery. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
PURPOSE: To analyze the effects of variations in femtosecond laser energy level on corneal stromal cell death. and inflammatory cell influx following flap creation in a rabbit model. METHODS: Eighteen rabbits were stratified in three different groups according to level of energy applied for flap creation (six animals per group). Three different energy levels were chosen for both the lamellar and side cut; 2.7 mu J (high energy), 1.6 mu J (intermediate energy), and 0.5 mu J (low energy) with a 60 kHz, model II, femtosecond laser (IntraLase). The opposite eye of each rabbit served as a control. At the 24-hour time point after surgery, all rabbits were euthanized and the comeoscleral rims were analyzed for the levels of cell death and inflammatory cell influx with the terminal uridine deoxynucleotidyl transferase dUTP-nick end labeling (TUNEL) assay and immunocytochemistry for monocyte marker CD11b, respectively. RESULTS: The high energy group (31.9 +/- 7.1 [standard error of mean (SEM) 2.9]) had significantly more TUNEL positive cells in the central flap compared to the intermediate (22.2 +/- 1.9 [SEM 0.8], P=.004), low (17.9 +/- 4.0 [SEM 1.6], P <= .001), and control eye (0.06 +/- 0.02 [SEM 0.009], P <= .001) groups. The intermediate and low energy groups also had significantly more TUNEL positive cells than the control groups (P <= .001). The difference between the intermediate and low energy levels was not significant (P=.56). The mean for CD11b-positive cells/400x field at the flap edge was 26.1 +/- 29.3 (SEM 11.9), 5.8 +/- 4.1 (SEM 1.6), 1.6 +/- 4.1 (SEM 1.6), and 0.005 +/- 0.01 (SEM 0.005) for high energy, intermediate energy, low energy, and control groups, respectively. Only the intermediate energy group showed statistically more inflammatory cells than control eyes (P = .015), most likely due to variability between eyes. CONCLUSIONS: Higher energy levels trigger greater cell death when the femtosecond laser is used to create corneal flaps: Greater corneal inflammatory cell infiltration is observed with higher femtosecond laser energy levels. [J Refract Surg. 2009;25:869-874.] doi:10.3928/1081597X-20090917-08
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Objective: Natural killer T (NKT) cells are efficiently targeted by HIV and severely reduced in numbers in the circulation of infected individuals. The functional capacity of the remaining NKT cells in HIV-infected individuals is poorly characterized. This study measured NKT cell cytokine production directly ex vivo and compared these responses with both the disease status and NKT subset distribution of individual patients. Methods: NKT cell frequencies, subsets, and ex-vivo effector functions were measured in the peripheral blood mononuclear cells of HIV-infected patients and healthy controls by flow cytometry. We measured cytokines from NKT cells after stimulation with either a-galactosyl ceramide-loaded CD1d dimers (DimerX-alpha GalCer) or phorbol myristate acetate and ionomycin. Results: The frequencies of NKT cells secreting interferon-gamma and tumor necrosis factor-alpha were significantly lower in HIV-infected patients than healthy controls after DimerX-alpha GalCer treatment, but responses were similar after treatment with phorbol myristate acetate and ionomycin. The magnitude of the interferon-gamma response to DimerX-alpha GalCer correlated inversely with the number of years of infection. Both interferon-gamma and tumor necrosis factor-alpha production in response to DimerX-alpha GalCer correlated inversely with CD161 expression. Conclusion: The ex-vivo Th1 responses of circulating NKT cells to CD1d-glycolipid complexes are impaired in HIV-infected patients. NKT cell functions may be progressively lost over time in HIV infection, and CD161 is implicated in the regulation of NKT cell responsiveness. (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins
Resumo:
Five refractory obsessive-compulsive patients were assessed using a neuropsychological battery after a modified gamma knife capsulotomy. The surgical technique was not associated with profound cognitive deficits. The authors found improvements in attention, vocabulary, learning, abstract reasoning, and memory. (The journal of Neuropsychiatry and Clinical Neurosciences 2009; 21:393-397)
Resumo:
We measured T-cell responses to human immunodeficiency virus type 1 (HIV-1) cryptic epitopes encoded by regions of the viral genome not normally translated into viral proteins. T-cell responses to cryptic epitopes and to regions normally spliced out of the HIV-1 viral proteins Rev and Tat were detected in HIV-1-infected subjects.
Resumo:
Previous studies have suggested that abnormal corneal wound healing in patients after photorefractive keratectomy (PRK) is associated with the appearance of myofibroblasts in the stroma between two and four weeks after surgery. The purpose of this study was to examine potential myofibroblast progenitor cells that might express other filament markers prior to completion of the differentiation pathway that yields a-smooth muscle actin (SMA)-expressing myofibroblasts associated with haze localized beneath the epithelial basement membrane after PRK. Twenty-four female rabbits that had -9 diopter PRK were sacrificed at I week, 2 weeks, 3 weeks or 4 weeks after surgery. Corneal rims were collected, frozen at -80 degrees C, and analyzed by immunocytochemistry using anti-vimentin, anti-desmin, and anti-SMA antibodies. Double immunostaining was performed for the co-localization of SMA with vimentin or desmin with SMA. An increase in vimentin expression in stromal cells is noted as early as 1 week after PRK in the rabbit cornea. As the healing response continues at two or three weeks after surgery, many stromal cells expressing vimentin also begin to express desmin and SMA. By 4 weeks after the surgery most, if not all, myofibroblasts express vimentin, desmin and SMA. Generalized least squares regression analysis showed that there was strong evidence that each of the marker groups differed in expression over time compared to the other two (p < 0.01). Intermediate filaments - vimentin and desmin co-exist in myofibroblasts along with SMA and may play an important role in corneal remodeling after photorefractive keratectomy. The earliest precursors of myofibroblasts destined to express SMA and desmin are detectible by staining for vimentin at I week after surgery. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
Tetralogy of Fallot (TOF), the most common severe congenital heart malformation, occurs sporadically, without other anomaly, and from unknown cause in 70% of cases. Through a genome-wide survey of 114 subjects with TOF and their unaffected parents, we identified 11 de novo copy number variants (CNVs) that were absent or extremely rare (<0.1%) in 2,265 controls. We then examined a second, independent TOF cohort (n = 398) for additional CNVs at these loci. We identified CNVs at chromosome 1q21.1 in 1% (5/512, P = 0.0002, OR = 22.3) of nonsyndromic sporadic TOF cases. We also identified recurrent CNVs at 3p25.1, 7p21.3 and 22q11.2. CNVs in a single subject with TOF occurred at six loci, two that encode known (NOTCH1, JAG1) disease-associated genes. Our findings predict that at least 10% (4.5-15.5%, 95% confidence interval) of sporadic nonsyndromic TOF cases result from de novo CNVs and suggest that mutations within these loci might be etiologic in other cases of TOF.
Resumo:
Myofibroblast development and haze generation in the corneal stroma is mediated by cytokines, including transforming growth factor-beta (TGF-beta), and possibly other cytokines. This study examined the effects of stromal PDGF-beta blockade on the development of myofibroblasts in response to -9.0 diopter photorefractive keratectomy in the rabbit. Rabbits that had haze generating photorefractive keratectomy (PRK, for 9 diopters of myopia) in one eye were divided into three different groups: stromal application of plasmid pCMV.PDGFRB.23KDEL expressing a subunit of PDGF receptor b (domains 2-3, which bind PDGF-B), stromal application of empty plasmid pCMV, or stromal application of balanced salt solution (BSS). The plasmids (at a concentration 1000 ng/mu l) or BSS was applied to the exposed stroma immediately after surgery and every 24 h for 4-5 days until the epithelium healed. The group treated with pCMV.PDGFRB.23KDEL showed lower alpha SMA+ myofibroblast density in the anterior stroma compared to either control group (P <= 0.001). Although there was also lower corneal haze at the slit lamp at one month after surgery, the difference in haze after PDGF-B blockade was not statistically significant compared to either control group. Stromal PDGF-B blockade during the early postoperative period following PRK decreases stromal alpha SMA+ myofibroblast generation. PDGF is an important modulator of myofibroblast development in the cornea. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
PURPOSE: To compare mechanical and ethanol epithelial removal with respect to myofibroblast development and haze formation after photorefractive keratectomy (PRK). METHODS: Seventeen rabbits underwent mechanical or ethanol debridement, and the opposite eye of each rabbit served as an unwounded control. In both groups, the epithelium was removed with a spatula and discarded. A -9.00-diopter PRK was performed in each eye. The level of haze in each cornea at 4 weeks was graded at the slit-lamp microscope according to the Fantes scale. Myofibroblast generation was detected with immunocytochemistry for alpha-smooth muscle actin (alpha-SMA) and cells were quantitatively analyzed. RESULTS: No difference was noted between the two groups in alpha-SMA + myofibroblasts 4 weeks after surgery (43.6 +/- 2.0/400X field and 45.7 +/- 4.8/400X field in ethanol and mechanical groups, respectively) (P=.10). A slight difference was noted but did not reach statistical significance with regard to stromal haze between ethanol and mechanical groups (2.0 +/- 0.5 and 2.3 +/- 0.4, respectively, P=.063). The ethanol and mechanical groups were statistically different when compared to controls regarding stromal haze and alpha-SMA+ cells (P <.0001 for all comparisons). CONCLUSIONS:No difference was noted in clinical haze or myofibroblast generation between corneas that had PRK with mechanical,or ethanol epithelial debridement. [J Refract Surg., 2008;24:923-927.]
Resumo:
Interleukin (IL)-1 alpha and beta are important modulators of many functions of corneal epithelial and stromal cells that occur following injury to the cornea, including the influx of bone marrow-derived inflammatory cells into the stroma attracted by chemokines released from the stroma and epithelium. In this study, we examined the effect of topical soluble IL-1 receptor antagonist on bone marrow-derived cell influx following corneal epithelial scrape injury in a mouse model. C57BL/6 mice underwent corneal epithelial scrape followed by application of IL-1 receptor antagonist (Amgen, Thousand Oaks, CA) at a concentration of 20 mg/ml or vehicle for 24 h prior to immunocytochemical detection of marker CD11b-positive cells into the stroma. In two experiments, topical IL-1 receptor antagonist had a marked effect in blocking cell influx. For example, in experiment 1, topical IL-1 receptor antagonist markedly reduced detectible CD11b-positive cells into the corneal stroma at 24 It after epithelial injury compared with the vehicle control (3.5 +/- 0.5 (standard error of the mean) cells/400x field and 13.9 +/- 1.2 cells/400x field, respectively, p < 0.01). A second experiment with a different observer performing cell counting had the same result. Thus, the data demonstrate conclusively that topical IL-1 receptor antagonist markedly down-regulates CD-11b-positive monocytic cell appearance in the corneal stroma. Topical IL-1 receptor antagonist could be an effective adjuvant for clinical treatment of corneal conditions in which unwanted inflammation has a role in the pathophysiology of the disorder. (c) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Background: We studied the characteristics of family functioning in bipolar children and healthy comparison children. We hypothesized that the family environment of bipolar children would show greater levels of dysfunction as measured by the Family Environment Scale (FES). Methods: We compared the family functioning of 36 families that included a child with DSM-IV bipolar disorder versus 29 comparison families that included only healthy children. All subjects and their parents were assessed with the K-SADS-PL interview. The parents completed the FES to assess their current family functioning. Multivariate analysis of variance was used to compare the family environment of families with and without offspring with bipolar disorder. Results: Parents of bipolar children reported lower levels of family cohesion (p<0.001), expressiveness (p=0.005), active-recreational orientation (p<0.001), intellectual-cultural orientation (p=0.04) and higher levels of conflict (p<0.001) compared to parents with no bipolar children. Secondary analyses within the bipolar group revealed lower levels of organization (p=0.03 1) and cohesion (p=0.014) in families where a parent had a history of mood disorders compared to families where parents had no history of mood disorders. Length of illness in the affected child was inversely associated with family cohesion (r=-0.47, p=0.004). Limitations: Due to the case-control design of the study, we cannot comment on the development of these family problems or attribute their cause specifically to child bipolar disorder. Conclusion: Families with bipolar children show dysfunctional patterns related to interpersonal interactions and personal growth. A distressed family environment should be addressed when treating children with bipolar disorder. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
Chantler PD, Nussbacher A, Gerstenblith G, Schulman SP, Becker LC, Ferrucci L, Fleg JL, Lakatta EG, Najjar SS. Abnormalities in arterial-ventricular coupling in older healthy persons are attenuated by sodium nitroprusside. Am J Physiol Heart Circ Physiol 300: H1914-H1922, 2011. First published March 4, 2011; doi:10.1152/ajpheart.01048.2010.-The coupling between arterial elastance (E(A); net afterload) and lea ventricular elastance (E(LV); pump performance), known as E(A)/E(LV), is a key determinant of cardiovascular performance and shifts during exercise due to a greater increase in E(LV) versus E(A). This normal exercise-induced reduction in E(A)/E(LV) decreases with advancing age. We hypothesized that sodium. nitroprusside (SNP) can acutely ameliorate the age-associated deficits in E(A)/E(LV). At rest and during graded exercise to exhaustion, EA was characterized as end-systolic pressure/stroke volume and E(LV) as end-systolic pressure/end-systolic volume. Resting E(A)/E(LV): did not differ between old (70 +/- 8 yr. n = 15) and young (30 +/- 5 yr. n = 17) subjects because of a tandem increase in E(A) and E(LV) in older subjects. During peak exercise, a blunted increase in E(LV) in old (7.8 +/- 3.1 mmHg/ml) versus young (11.4 +/- 6.5 mmHg/ml) subjects blunted the normal exercise-induced decline in E(A)/E(LV) in old (0.25 +/- 0.11) versus young (0.16 +/- 0.05) subjects. SNP administration to older subjects lowered resting E(A)/E(LV) by 31% via a reduction E(A) (10%) and an increase in E(LV) (47%) and lowered peak exercise E(A)/E(LV) (36%) via an increase in E(LV) (68%) without a change in E(A). Importantly, SNP attenuated the age-associated deficits in E(A)/E(LV) and E(LV) during exercise, and at peak exercise E(A)/E(LV) in older subjects on drug administration did not differ from young subjects without drug administration. In conclusion, some age-associated deficiencies in E(A)/E(LV), E(A), and E(LV), in older subjects can be acutely abolished by SNP infusion. This is relevant to common conditions in older subjects associated with a significant impairment of exercise performance such as frailty or heart failure with preserved ejection fraction.
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Background/Objectives: Vitamin A deficiency (VAD) is a world public health problem contributing to the increase in childhood morbidity and mortality in developing countries and severe deficiency of vitamin A may lead to xerophthalmia and blindness. The objective of this study was to determine the prevalence of VAD among Brazilian school-aged children attended at a primary health unit and to verify if some considered risk factor was associated with VAD in this group. Subjects/Methods: A descriptive prospective transverse study was conducted on 103 randomly selected children. A total of 54 boys and 49 girls aged 5.5-11 years had the relative dose-response (RDR) test performed on. Possible ocular alterations related to vitamin A and the status of anemia, serum zinc, some acute-phase proteins, and anthropometric situation were determinate by an analytic design. Results: No child presented xerophthalmia. Serum retinol values lower than 1.05 and 0.7 mu moll(-1), respectively were found in 26.2 and 5.8% of the children. The prevalence of hypovitaminosis detected by RDR test was 20.4%. The following variables and their relationship with VAD were evaluated: sex (P = 0.33; 95% confidence interval 0.61-4.34), weight and height (P >= 0.5), hemoglobin (P = 0.15), C-reactive protein (P = 0.56; 95% confidence interval 0.75-18.26), alpha-1-acid-glycoprotein (P = 0.56; 95% confidence interval 0.15-15.42) and serum zinc (P = 0.31). None of these variables was related to VAD. Conclusions: In this population, the prevalence of VAD detected could be considered a public health problem. School-aged children can be considered at risk for VAD mainly of a subclinical level, even without some associated risk factors.
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Schistosoma mansoni is responsible for the neglected tropical disease schistosomiasis that affects 210 million people in 76 countries. Here we present analysis of the 363 megabase nuclear genome of the blood fluke. It encodes at least 11,809 genes, with an unusual intron size distribution, and new families of micro-exon genes that undergo frequent alternative splicing. As the first sequenced flatworm, and a representative of the Lophotrochozoa, it offers insights into early events in the evolution of the animals, including the development of a body pattern with bilateral symmetry, and the development of tissues into organs. Our analysis has been informed by the need to find new drug targets. The deficits in lipid metabolism that make schistosomes dependent on the host are revealed, and the identification of membrane receptors, ion channels and more than 300 proteases provide new insights into the biology of the life cycle and new targets. Bioinformatics approaches have identified metabolic chokepoints, and a chemogenomic screen has pinpointed schistosome proteins for which existing drugs may be active. The information generated provides an invaluable resource for the research community to develop much needed new control tools for the treatment and eradication of this important and neglected disease.