129 research outputs found

    A Method of Drusen Measurement Based on the Geometry of Fundus Reflectance

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    BACKGROUND: The hallmarks of age-related macular degeneration, the leading cause of blindness in the developed world, are the subretinal deposits known as drusen. Drusen identification and measurement play a key role in clinical studies of this disease. Current manual methods of drusen measurement are laborious and subjective. Our purpose was to expedite clinical research with an accurate, reliable digital method. METHODS: An interactive semi-automated procedure was developed to level the macular background reflectance for the purpose of morphometric analysis of drusen. 12 color fundus photographs of patients with age-related macular degeneration and drusen were analyzed. After digitizing the photographs, the underlying background pattern in the green channel was leveled by an algorithm based on the elliptically concentric geometry of the reflectance in the normal macula: the gray scale values of all structures within defined elliptical boundaries were raised sequentially until a uniform background was obtained. Segmentation of drusen and area measurements in the central and middle subfields (1000 μm and 3000 μm diameters) were performed by uniform thresholds. Two observers using this interactive semi-automated software measured each image digitally. The mean digital measurements were compared to independent stereo fundus gradings by two expert graders (stereo Grader 1 estimated the drusen percentage in each of the 24 regions as falling into one of four standard broad ranges; stereo Grader 2 estimated drusen percentages in 1% to 5% intervals). RESULTS: The mean digital area measurements had a median standard deviation of 1.9%. The mean digital area measurements agreed with stereo Grader 1 in 22/24 cases. The 95% limits of agreement between the mean digital area measurements and the more precise stereo gradings of Grader 2 were -6.4 % to +6.8 % in the central subfield and -6.0 % to +4.5 % in the middle subfield. The mean absolute differences between the digital and stereo gradings 2 were 2.8 +/- 3.4% in the central subfield and 2.2 +/- 2.7% in the middle subfield. CONCLUSIONS: Semi-automated, supervised drusen measurements may be done reproducibly and accurately with adaptations of commercial software. This technique for macular image analysis has potential for use in clinical research

    Educational paper: Abusive Head Trauma Part I. Clinical aspects

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    Abusive Head Trauma (AHT) refers to the combination of findings formerly described as shaken baby syndrome. Although these findings can be caused by shaking, it has become clear that in many cases there may have been impact trauma as well. Therefore a less specific term has been adopted by the American Academy of Pediatrics. AHT is a relatively common cause of childhood neurotrauma with an estimated incidence of 14–40 cases per 100,000 children under the age of 1 year. About 15–23% of these children die within hours or days after the incident. Studies among AHT survivors demonstrate that approximately one-third of the children are severely disabled, one-third of them are moderately disabled and one-third have no or only mild symptoms. Other publications suggest that neurological problems can occur after a symptom-free interval and that half of these children have IQs below the 10th percentile. Clinical findings are depending on the definitions used, but AHT should be considered in all children with neurological signs and symptoms especially if no or only mild trauma is described. Subdural haematomas are the most reported finding. The only feature that has been identified discriminating AHT from accidental injury is apnoea. Conclusion: AHT should be approached with a structured approach, as in any other (potentially lethal) disease. The clinician can only establish this diagnosis if he/she has knowledge of the signs and symptoms of AHT, risk factors, the differential diagnosis and which additional investigations to perform, the more so since parents seldom will describe the true state of affairs spontaneously

    Celastrol inhibits aminoglycoside-induced ototoxicity via heat shock protein 32

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    Hearing loss is often caused by death of the mechanosensory hair cells of the inner ear. Hair cells are susceptible to death caused by aging, noise trauma, and ototoxic drugs, including the aminoglycoside antibiotics and the antineoplastic agent cisplatin. Ototoxic drugs result in permanent hearing loss for over 500 000 Americans annually. We showed previously that induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. In order to begin to translate these findings into a clinical therapy aimed at inhibiting ototoxic drug-induced hearing loss, we have now examined a pharmacological HSP inducer, celastrol. Celastrol induced upregulation of HSPs in utricles, and it provided significant protection against aminoglycoside-induced hair cell death in vitro and in vivo. Moreover, celastrol inhibited hearing loss in mice receiving systemic aminoglycoside treatment. Our data indicate that the major heat shock transcription factor HSF-1 is not required for celastrol-mediated protection. HSP32 (also called heme oxygenase-1, HO-1) is the primary mediator of the protective effect of celastrol. HSP32/HO-1 inhibits pro-apoptotic c-Jun N-terminal kinase (JNK) activation and hair cell death. Taken together, our data indicate that celastrol inhibits aminoglycoside ototoxicity via HSP32/HO-1 induction

    Hirschsprung's disease in the newborn

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    The records of all patients with Hirschsprung's disease diagnosed and treated at our institution between 1 July 1974 and 31 August 1985 were reviewed. Of these 99 patients, 35 (35%) presented and were diagnosed within the first 30 days of life and constitute the basis of the present study group. Twenty-two infants (63%) had standard rectosigmoid disease with a male-to-female ratio of 2.2:1. Only one infant was premature. The spectrum of presenting signs included abdominal distension in 19 (54%), failure to pass meconium within the first 48 h of life in 16 (46%), “constipation” in 12 (34%), and vomiting in 9 (26%). Intestinal perforation was a presenting sign in 2 patients (6%) and enterocolitis occurred preoperatively in 4 (12%). Evaluation was facilitated by diagnostic barium enema in 60% of the patients. In those infants able to undergo elective evaluation, the definitive diagnosis was made by suction rectal biopsy, which was accurate in all cases. In addition to the high proportion of patients with long-segment disease (13 patients, 37%), there was a significant incidence of associated congenital anomalies (26%), including Down's syndrome in 5 (14%). Thirty-three of the 35 patients have undergone definitive treatment using the endorectal pull-through procedure, performed at an average age of 12 months, with no mortality related to the operation. In addition to highlighting the high incidence of congenital anomalies, the large proportion of neonates with long-segment disease, and the reliability of the diagnostic barium enema, this subgroup of patients with Hirschsprung's disease emphasizes the special diagnostic and management considerations required in the newborn infant who presents with sepsis of unknown etiology, intestinal obstruction, or constipation. A high index of suspicion, liberal use of suction rectal biopsy, early leveling colostomy, and definitive treatment by endorectal pull-through are important in achieving 0% operative mortality and excellent functional results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47145/1/383_2004_Article_BF00166865.pd

    Collagen I but not Matrigel matrices provide an MMP-dependent barrier to ovarian cancer cell penetration

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    Abstract Background The invasive potential of cancer cells is usually assessed in vitro using Matrigel as a surrogate basement membrane. Yet cancer cell interaction with collagen I matrices is critical, particularly for the peritoneal metastatic route undertaken by several cancer types including ovarian. Matrix metalloprotease (MMP) activity is important to enable cells to overcome the barrier constraints imposed by basement membranes and stromal matrices in vivo. Our objective was to compare matrices reconstituted from collagen I and Matrigel as representative barriers for ovarian cancer cell invasion. Methods The requirement of MMP activity for ovarian cancer cell penetration of Matrigel and collagen matrices was assessed in 2D transwell and 3D spheroid culture systems. Results The broad range MMP inhibitor GM6001 completely prevented cell perforation of polymerised collagen I-coated transwell membranes. In contrast, GM6001 decreased ES-2 cell penetration of Matrigel by only ~30% and had no effect on HEY cell Matrigel penetration. In 3D culture, ovarian cancer cells grown as spheroids also migrated into surrounding Matrigel matrices despite MMP blockade. In contrast, MMP activity was required for invasion into 3D matrices of collagen I reconstituted from acid-soluble rat-tail collagen I, but not from pepsin-extracted collagen I (Vitrogen/Purecol), which lacks telopeptide regions. Conclusion Matrigel does not form representative barriers to ovarian cancer cells in either 2D or 3D culture systems. Our findings support the use of collagen I rather than Matrigel as a matrix barrier for invasion studies to better approximate critical interactions and events associated with peritoneal metastasis

    AKT1 polymorphisms are associated with risk for metabolic syndrome

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    Converging lines of evidence suggest that AKT1 is a major mediator of the responses to insulin, insulin-like growth factor 1 (IGF1), and glucose. AKT1 also plays a key role in the regulation of both muscle cell hypertrophy and atrophy. We hypothesized that AKT1 variants may play a role in the endophenotypes that make up metabolic syndrome. We studied a 12-kb region including the first exon of the AKT1 gene for association with metabolic syndrome-related phenotypes in four study populations [FAMUSS cohort (n = 574; age 23.7 ± 5.7 years), Strong Heart Study (SHS) (n = 2,134; age 55.5 ± 7.9 years), Dynamics of Health, Aging and Body Composition (Health ABC) (n = 3,075; age 73.6 ± 2.9 years), and Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE) (n = 175; age 40–65 years)]. We identified a three SNP haplotype that we call H1, which represents the ancestral alleles at the three loci and H2, which represents the derived alleles at the three loci. In young adult European Americans (FAMUSS), H1 was associated with higher fasting glucose levels in females. In middle age Native Americans (SHS), H1 carriers showed higher fasting insulin and HOMA in males, and higher BMI in females. In older African-American and European American subjects (Health ABC) H1 carriers showed a higher incidence of metabolic syndrome. Homozygotes for the H1 haplotype showed about twice the risk of metabolic syndrome in both males and females (p < 0.001). In middle-aged European Americans with insulin resistance (STRRIDE) studied by intravenous glucose tolerance test (IVGTT), H1 carriers showed increased insulin resistance due to the Sg component (p = 0.021). The 12-kb haplotype is a risk factor for metabolic syndrome and insulin resistance that needs to be explored in further populations

    Depression and Sexual Orientation During Young Adulthood: Diversity Among Sexual Minority Subgroups and the Role of Gender Nonconformity.

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    Sexual minority individuals are at an elevated risk for depression compared to their heterosexual counterparts, yet less is known about how depression status varies across sexual minority subgroups (i.e., mostly heterosexuals, bisexuals, and lesbians and gay men). Moreover, studies on the role of young adult gender nonconformity in the relation between sexual orientation and depression are scarce and have yielded mixed findings. The current study examined the disparities between sexual minorities and heterosexuals during young adulthood in concurrent depression near the beginning of young adulthood and prospective depression 6 years later, paying attention to the diversity within sexual minority subgroups and the role of gender nonconformity. Drawn from the National Longitudinal Study of Adolescent Health (N = 9421), we found that after accounting for demographics, sampling weight, and sampling design, self-identified mostly heterosexual and bisexual young adults, but not lesbians and gay men, reported significantly higher concurrent depression compared to heterosexuals; moreover, only mostly heterosexual young adults were more depressed than heterosexuals 6 years later. Furthermore, while young adult gender nonconforming behavior was associated with more concurrent depression regardless of sexual orientation, its negative impact on mental health decreased over time. Surprisingly, previous gender nonconformity predicted decreased prospective depression among lesbians and gay men whereas, among heterosexual individuals, increased gender nonconformity was not associated with prospective depression. Together, the results suggested the importance of investigating diversity and the influence of young adult gender nonconformity in future research on the mental health of sexual minorities.The authors acknowledge support for this research: the University of Arizona Norton School of Family and Consumer Sciences Fitch Nesbitt Endowment and a University of Arizona Graduate Access Fellowship to the second author. This research uses data from Add Health, a program project directed by Kathleen Mullan Harris and designed by J. Richard Udry, Peter S. Bearman, and Kathleen Mullan Harris at the University of North Carolina at Chapel Hill, and funded by grant P01-HD31921 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, with cooperative funding from 23 other federal agencies and foundations. Special acknowledgment is due Ronald R. Rindfuss and Barbara Entwisle for assistance in the original design. Information on how to obtain the Add Health data files is available on the Add Health website (http://​www.​cpc.​unc.​edu/​addhealth). No direct support was received from grant P01-HD31921 for this analysis. The authors thank Noel Card and Susan Stryker for comments on the previous versions of this article and Richard Lippa and Katerina Sinclair for methodological and statistical consult. The authors also thank the anonymous reviewers and the Editor for their helpful comments.This is the accepted manuscript of a paper published in Archives of Sexual Behavior (Li G, Pollitt AM, Russell ST, Archives of Sexual Behavior 2015, doi:10.1007/s10508-015-0515-3). The final version is available at http://dx.doi.org/10.1007/s10508-015-0515-3

    Cell–cell and cell–matrix dynamics in intraperitoneal cancer metastasis

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    The peritoneal metastatic route of cancer dissemination is shared by cancers of the ovary and gastrointestinal tract. Once initiated, peritoneal metastasis typically proceeds rapidly in a feed-forward manner. Several factors contribute to this efficient progression. In peritoneal metastasis, cancer cells exfoliate into the peritoneal fluid and spread locally, transported by peritoneal fluid. Inflammatory cytokines released by tumor and immune cells compromise the protective, anti-adhesive mesothelial cell layer that lines the peritoneal cavity, exposing the underlying extracellular matrix to which cancer cells readily attach. The peritoneum is further rendered receptive to metastatic implantation and growth by myofibroblastic cell behaviors also stimulated by inflammatory cytokines. Individual cancer cells suspended in peritoneal fluid can aggregate to form multicellular spheroids. This cellular arrangement imparts resistance to anoikis, apoptosis, and chemotherapeutics. Emerging evidence indicates that compact spheroid formation is preferentially accomplished by cancer cells with high invasive capacity and contractile behaviors. This review focuses on the pathological alterations to the peritoneum and the properties of cancer cells that in combination drive peritoneal metastasis

    The Efficacy of Trastuzumab in Animal Models of Breast Cancer:A Systematic Review and Meta-Analysis

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    BACKGROUND:Breast cancer is the most frequent cancers and is the second leading cause of cancer death among women. Trastuzumab is an effective treatment, the first monoclonal antibody directed against the human epidermal growth factor receptor 2 (HER2). To inform the development of other effective treatments we report summary estimates of efficacy of trastuzumab on survival and tumour volume in animal models of breast cancer. METHODS:We searched PubMed and EMBASE systematically to identify publications testing trastuzumab in animal models of breast cancer. Data describing tumour volume, median survival and animal features were extracted and we assessed quality using a 12-item checklist. We analysed the impact of study design and quality and evidence for publication bias. RESULTS:We included data from 83 studies reporting 169 experiments using 2076 mice. Trastuzumab treatment caused a substantial reduction in tumour growth, with tumours in treated animals growing to 32.6% of the volume of tumours in control animals (95%CI 27.8%-38.2%). Median survival was prolonged by a factor of 1.45 (1.30-1.62). Many study design and quality features accounted for between-study heterogeneity and we found evidence suggesting publication bias. CONCLUSION:We have found trastuzumab to be effective in animal breast cancer models across a range of experimental circumstances. However the presence of publication bias and a low prevalence of measures to reduce bias provide a focus for future improvements in preclinical breast cancer research
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