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2.
J Pediatr Orthop ; 43(2): 117-122, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36607928

ABSTRACT

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is characterized by joint contractures in 2 or more body areas, often resulting in clubfoot deformities that are typically stiffer than those seen in idiopathic clubfoot deformities. While surgery is routinely used to treat clubfoot in AMC, it has a high rate of recurrence and complications. Current literature suggests serial casting (SC) could be useful in treating clubfoot in AMC, though evidence of its effectiveness is limited. METHODS: Passive range of motion (PROM), dynamic foot pressure, parent-reported Pediatric Outcomes Data Collection Instrument, brace tolerance, and the need for post-casting surgery were evaluated retrospectively in children with AMC treated with SC to address clubfoot deformities. Analysis of variance or paired t tests were used as appropriate on pre-casting, short-term (within 6 mo after SC) and/or longer-term (6 to 18 mo after SC) parameters to determine the effectiveness of SC. Brace tolerance before and after SC was analyzed using the Global Test for Symmetry, and medical records were reviewed to determine the need for surgery post-SC. RESULTS: Forty-six children (6.1±3.1 y old) were cast an average of 2.5±1.9 times, resulting in 206 SC episodes. PROM showed improvement in ankle dorsiflexion and forefoot abduction in the short term (P<0.05), returning to baseline measurements in the long term (P=0.09). Brace tolerance improved after casting (P<0.05). Only 15% of feet required surgery at follow-up at 10.3±5.5 years. There were no significant changes in dynamic foot pressure or Pediatric Outcomes Data Collection Instrument results after SC, except for an increase in the pain subtest (P<0.05). CONCLUSIONS: Serial casting in children with AMC can be effective in temporarily improving PROM and improving brace tolerance, but it does not impact dynamic barefoot position. Positive impact of conservative management in children with AMC can potentially delay or reduce the need for invasive surgical intervention by improving PROM and brace tolerance. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.


Subject(s)
Arthrogryposis , Clubfoot , Humans , Child , Infant , Clubfoot/complications , Arthrogryposis/therapy , Arthrogryposis/complications , Retrospective Studies , Treatment Outcome , Casts, Surgical
3.
Dev Med Child Neurol ; 64(10): 1289-1296, 2022 10.
Article in English | MEDLINE | ID: mdl-35338776

ABSTRACT

AIM: To determine how surgical burden and preoperative factors affect the recovery of walking activity after multilevel orthopedic surgery (MLS). METHOD: In this retrospective study, inclusion criteria were a diagnosis of cerebral palsy, MLS, and walking activity monitoring using a StepWatch device within 12 months pre-MLS and 24 months post-MLS. The outcome measure was total mean strides per day normalized to age and Gross Motor Function Classification System level. Pre- and postoperative walking activity were compared using unpaired t-tests; the effects of preoperative predictors and surgical burden on the recovery of walking activity were evaluated using regression analysis. RESULTS: Participants included 178 children (mean age 12 years 10 months [SD 8 years 7 months; range 4-20 years]; 91 males, 87 females). On average, children returned to baseline walking activity 3 months after low-burden surgery and 1 year 2 months after high-burden surgery. Postoperative walking activity was higher for children who had surgery at a younger age and those with a higher preoperative mobility function. INTERPRETATION: The burden of MLS was found to be inversely related to the time to recovery of postoperative walking activity. These findings provide evidence to help clinicians set expectations for return to function post-MLS. Further study is necessary to investigate the impact of postoperative factors on walking activity recovery. WHAT THIS PAPER ADDS: High-burden surgeries lead to longer recovery than low-burden surgeries. Younger children recover walking activity faster after multilevel orthopedic surgery. Children with high preoperative mobility function recover walking activity faster after surgery.


OBJETIVO: Determinar como a carga cirúrgica e os fatores pré-operatórios afetam a recuperação da atividade de caminhada após cirurgia ortopédica multinível (MLS). MÉTODOS: Neste estudo retrospectivo, os critérios de inclusão foram um diagnóstico de paralisia cerebral, MLS e monitoramento da atividade de caminhada usando um dispositivo Step Watch dentro de 12 meses pré-MLS e 24 meses pós-MLS. A medida de resultado foi o total de passos médios por dia normalizados para idade e nível do Sistema de Classificação da Função Motora Grossa. A atividade de caminhada pré e pós-operatória foi comparada usando testes t não pareados; os efeitos dos preditores pré-operatórios e da carga cirúrgica na recuperação da atividade de caminhada foram avaliados por meio de análise de regressão. RESULTADOS: Os participantes incluíram 178 crianças (idade média de 12 anos e 10 meses [DP 8 anos e 7 meses; intervalo de 4 a 20 anos]; 91 meninos, 87 meninas). Em média, as crianças retornaram à atividade de caminhada inicial 3 meses após a cirurgia de baixa carga e 1 ano e 2 meses após a cirurgia de alta carga. A atividade de caminhada pós-operatória foi maior para crianças que foram operadas em idade mais jovem e aquelas com maior função de mobilidade pré-operatória. INTERPRETAÇÃO: A carga de MLS foi inversamente relacionada ao tempo de recuperação da atividade de caminhada pós-operatória. Esses achados fornecem evidências objetivas para ajudar os médicos a definir as expectativas de retorno à função pós-MLS. Mais estudos são necessários para investigar o impacto dos fatores pós-operatórios na recuperação da atividade de caminhada.


Subject(s)
Cerebral Palsy , Orthopedic Procedures , Cerebral Palsy/surgery , Child , Female , Humans , Infant , Male , Outcome Assessment, Health Care , Retrospective Studies , Walking
4.
Pharmacol Res Perspect ; 9(4): e00833, 2021 08.
Article in English | MEDLINE | ID: mdl-34309243

ABSTRACT

Multiple choice questions (MCQs) are a common form of assessment in medical schools and students seek opportunities to engage with formative assessment that reflects their summative exams. Formative assessment with feedback and active learning strategies improve student learning outcomes, but a challenge for educators, particularly those with large class sizes, is how to provide students with such opportunities without overburdening faculty. To address this, we enrolled medical students in the online learning platform PeerWise, which enables students to author and answer MCQs, rate the quality of other students' contributions as well as discuss content. A quasi-experimental mixed methods research design was used to explore PeerWise use and its impact on the learning experience and exam results of fourth year medical students who were studying courses in clinical sciences and pharmacology. Most students chose to engage with PeerWise following its introduction as a noncompulsory learning opportunity. While students perceived benefits in authoring and peer discussion, students engaged most highly with answering questions, noting that this helped them identify gaps in knowledge, test their learning and improve exam technique. Detailed analysis of the 2015 cohort (n = 444) with hierarchical regression models revealed a significant positive predictive relationship between answering PeerWise questions and exam results, even after controlling for previous academic performance, which was further confirmed with a follow-up multi-year analysis (2015-2018, n = 1693). These 4 years of quantitative data corroborated students' belief in the benefit of answering peer-authored questions for learning.


Subject(s)
Education, Medical, Undergraduate/methods , Educational Measurement/methods , Education, Distance , Humans , Peer Group , Students, Medical , Surveys and Questionnaires
5.
Science ; 360(6389): 660-663, 2018 05 11.
Article in English | MEDLINE | ID: mdl-29748285

ABSTRACT

Glioblastoma is an aggressive brain tumor that carries a poor prognosis. The tumor's molecular and cellular landscapes are complex, and their relationships to histologic features routinely used for diagnosis are unclear. We present the Ivy Glioblastoma Atlas, an anatomically based transcriptional atlas of human glioblastoma that aligns individual histologic features with genomic alterations and gene expression patterns, thus assigning molecular information to the most important morphologic hallmarks of the tumor. The atlas and its clinical and genomic database are freely accessible online data resources that will serve as a valuable platform for future investigations of glioblastoma pathogenesis, diagnosis, and treatment.


Subject(s)
Brain Neoplasms/genetics , Brain Neoplasms/pathology , Glioblastoma/genetics , Glioblastoma/pathology , Atlases as Topic , Databases, Genetic , Gene Expression Profiling , Humans , Prognosis
6.
Nature ; 535(7612): 367-75, 2016 07 21.
Article in English | MEDLINE | ID: mdl-27409810

ABSTRACT

The transcriptional underpinnings of brain development remain poorly understood, particularly in humans and closely related non-human primates. We describe a high-resolution transcriptional atlas of rhesus monkey (Macaca mulatta) brain development that combines dense temporal sampling of prenatal and postnatal periods with fine anatomical division of cortical and subcortical regions associated with human neuropsychiatric disease. Gene expression changes more rapidly before birth, both in progenitor cells and maturing neurons. Cortical layers and areas acquire adult-like molecular profiles surprisingly late in postnatal development. Disparate cell populations exhibit distinct developmental timing of gene expression, but also unexpected synchrony of processes underlying neural circuit construction including cell projection and adhesion. Candidate risk genes for neurodevelopmental disorders including primary microcephaly, autism spectrum disorder, intellectual disability, and schizophrenia show disease-specific spatiotemporal enrichment within developing neocortex. Human developmental expression trajectories are more similar to monkey than rodent, although approximately 9% of genes show human-specific regulation with evidence for prolonged maturation or neoteny compared to monkey.


Subject(s)
Brain/growth & development , Brain/metabolism , Macaca mulatta/genetics , Transcriptome , Aging/genetics , Animals , Autism Spectrum Disorder/genetics , Brain/cytology , Brain/embryology , Cell Adhesion , Conserved Sequence , Female , Humans , Intellectual Disability/genetics , Male , Microcephaly/genetics , Neocortex/embryology , Neocortex/growth & development , Neocortex/metabolism , Neurodevelopmental Disorders/genetics , Neurogenesis/genetics , Risk Factors , Schizophrenia/genetics , Spatio-Temporal Analysis , Species Specificity , Transcription, Genetic/genetics
7.
Nature ; 508(7495): 199-206, 2014 Apr 10.
Article in English | MEDLINE | ID: mdl-24695229

ABSTRACT

The anatomical and functional architecture of the human brain is mainly determined by prenatal transcriptional processes. We describe an anatomically comprehensive atlas of the mid-gestational human brain, including de novo reference atlases, in situ hybridization, ultra-high-resolution magnetic resonance imaging (MRI) and microarray analysis on highly discrete laser-microdissected brain regions. In developing cerebral cortex, transcriptional differences are found between different proliferative and post-mitotic layers, wherein laminar signatures reflect cellular composition and developmental processes. Cytoarchitectural differences between human and mouse have molecular correlates, including species differences in gene expression in subplate, although surprisingly we find minimal differences between the inner and outer subventricular zones even though the outer zone is expanded in humans. Both germinal and post-mitotic cortical layers exhibit fronto-temporal gradients, with particular enrichment in the frontal lobe. Finally, many neurodevelopmental disorder and human-evolution-related genes show patterned expression, potentially underlying unique features of human cortical formation. These data provide a rich, freely-accessible resource for understanding human brain development.


Subject(s)
Brain/metabolism , Fetus/metabolism , Gene Expression Regulation, Developmental/genetics , Transcriptome , Anatomy, Artistic , Animals , Atlases as Topic , Brain/embryology , Conserved Sequence/genetics , Fetus/cytology , Fetus/embryology , Gene Regulatory Networks/genetics , Humans , Mice , Neocortex/embryology , Neocortex/metabolism , Species Specificity
8.
NMR Biomed ; 25(3): 452-63, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21387443

ABSTRACT

The objective of tissue engineering (TE) is to create functional replacements for various tissues; the mechanical properties of these engineered constructs are critical to their function. Several techniques have been developed for the measurement of the mechanical properties of tissues and organs; however, current methods are destructive. The field of TE will benefit immensely if biomechanical models developed by these techniques could be combined with existing imaging modalities to enable noninvasive, dynamic assessment of mechanical properties during tissue growth. Specifically, MR elastography (MRE), which is based on the synchronization of a mechanical actuator with a phase contrast imaging pulse sequence, has the capacity to measure tissue strain generated by sonic cyclic displacement. The captured displacement is presented in shear wave images from which the complex shear moduli can be extracted or simplified by a direct measure, termed the shear stiffness. MRE has been extended to the microscopic scale, combining clinical MRE with high-field magnets, stronger magnetic field gradients and smaller, more sensitive, radiofrequency coils, enabling the interrogation of smaller samples, such as tissue-engineered constructs. The following topics are presented in this article: (i) current mechanical measurement techniques and their limitations in TE; (ii) a description of the MRE system, MRE theory and how it can be applied for the measurement of mechanical properties of tissue-engineered constructs; (iii) a summary of in vitro MRE work for the monitoring of osteogenic and adipogenic tissues originating from human adult mesenchymal stem cells (MSCs); (iv) preliminary in vivo studies of MRE of tissues originating from mouse MSCs implanted subcutaneously in immunodeficient mice with an emphasis on in vivo MRE challenges; (v) future directions to resolve current issues with in vivo MRE in the context of how to improve the future role of MRE in TE.


Subject(s)
Elasticity Imaging Techniques/methods , Magnetic Resonance Imaging/methods , Models, Theoretical , Tissue Engineering/methods , Animals , Elasticity Imaging Techniques/instrumentation , Humans , Implants, Experimental , Magnetic Resonance Imaging/instrumentation , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/physiology , Stem Cell Transplantation , Stress, Mechanical
9.
Waste Manag ; 29(7): 2160-4, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19345569

ABSTRACT

A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) in pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition of wool-waste to the growth medium increased Swiss chard and basil tissue N, and NO(3)-N and NH(4)-N in growth medium relative to the unamended control. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) microanalysis of wool fibers sampled at the end of the experiments indicated various levels of decomposition, with some fibers retaining their original surface structure. Furthermore, most of the wool fibers' surfaces contained significant concentrations of S and much less N, P, or K. SEM/EDX revealed that some plant roots grow directly on wool-waste fibers suggesting either (1) root directional growth towards sites with greater nutrient concentration and/or (2) a possible role for roots or root exudates in wool decomposition. Results from this study suggest that uncomposted wool wastes can be used as soil amendment, growth medium constituent, and nutrient source for container-grown plants.


Subject(s)
Beta vulgaris/growth & development , Fertilizers , Ocimum basilicum/growth & development , Waste Products , Wool , Animals , Gardening , Sheep
10.
J Cell Mol Med ; 13(8B): 1896-1906, 2009 Aug.
Article in English | MEDLINE | ID: mdl-20187303

ABSTRACT

Bone marrow stem cells (BMSCs) are mobilized in response to ischemic attacks, e.g. myocardial infarction, to repair the damage, or by cytokines, e.g. granulocyte colony-stimulating factor (G-CSF), which is used to harvest BMSCs for autologous transplantation. In order to optimize BMSC mobilization strategy for cardiovascular repair, we investigated whether BMSCs mobilized by G-CSF share the same subtype profile as that by ischemia in a non-human primate model. We subjected five baboons to subcutaneous G-CSF injection and five baboons to femoral artery ligation. Blood BMSCs were measured by surface antigens; functional differentiation to endothelial cells (ECs) was assessed by colony-forming capacity, expression of mature EC antigens and tube-like formation. The number of circulating CD34+/CD45RA- cells spiked on day 3 post-stimulation in both groups. While the number of CD34+ cells released by artery ligation was 2-fold lower by comparison with the number released by G-CSF administration, significantly more CD133+/KDR+/CXCR4+/CD31+ cells were detected in the baboons that underwent artery ligation. After culture in endothelial growth medium, mononuclear cells from baboons with artery ligation formed more EC colonies and more capillary-like tubes (P < 0.05), expressed higher vWF and phagocytosed more Dil-Ac-LDL (P < 0.05). While G-CSF and artery ligation can mobilize BMSCs capable of differentiating into ECs, BMSCs mobilized by the artery ligation simulating in vivo ischemic attacks have higher potential for vascular differentiation. Our findings demonstrate that different mobilization forces release different sets of BMSCs that may have different capacity for cardiovascular differentiation.


Subject(s)
Granulocyte Colony-Stimulating Factor/pharmacology , Hematopoietic Stem Cells/drug effects , Animals , Arteries/pathology , Flow Cytometry , Granulocyte Colony-Stimulating Factor/administration & dosage , Hematopoietic Stem Cells/cytology , Papio
11.
J Med Primatol ; 37(4): 169-72, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18194223

ABSTRACT

BACKGROUND: Stillbirths in non-human primates are a major problem and represent failure of the maternal-fetal-placental unit to maintain normal relationships because of various endogenous, undetermined or environmental factors. METHODS: Records of 236 stillborns and their dams in a Macaca fascicularis colony during a 7-year period were reviewed retrospectively. RESULTS: The 7-year stillbirth incidence was 11.99% (236 stillbirths, 1967 live births). Most (61.02%, n = 144) were of undetermined etiology. Fetal causes included trauma (22.46%, n = 53), fetal pneumonia (0.85%, n = 2) and congenital anomalies (0.42%, n = 1). Maternal causes included dystocia (9.75%, n = 23) and uterine rupture (0.42%, n = 1). Forty-nine placentas were available for histologic evaluation; there was placentitis in five, necrosis in five and placental abruption in two. Most stillbirths occurred close to term. First stillbirths usually occurred in 8- to 12-year-old animals during the first six pregnancies. CONCLUSIONS: Most stillbirths were of undetermined etiology. Fetal trauma was the most common cause.


Subject(s)
Macaca fascicularis , Stillbirth/veterinary , Animals , Female , Incidence , Male , Pregnancy , Risk Factors , Stillbirth/epidemiology
12.
Prostate ; 67(13): 1421-31, 2007 Sep 15.
Article in English | MEDLINE | ID: mdl-17639509

ABSTRACT

BACKGROUND: Prostate cancer, benign prostatic hyperplasia, and prostatitis frequently affect men worldwide. At present there are no suitable animal models for these diseases. This study explores the potential use of the baboon as a model for prostatic diseases. METHODS: Prostates of 48 baboons of different ages were studied. Prostate specific antigen (PSA) and alpha-methyl-acyl-CoA racemase (AMACR) were localized in the different lobes of the prostate by Western blotting and immunohistochemistry. PSA in baboon serum was demonstrated by radioimmunoassay and western blotting. Baboon AMACR cDNA was cloned and its expression assayed in baboon tissues. RESULTS: The baboon prostate is anatomically and histologically similar to its human counterpart, with cranial and caudal lobes corresponding to central and peripheral zones of the human prostate. We found lymphocytic infiltration (91%), and sclerosing/atrophic lesions (34%). PSA tissue immunostaining intensity and alpha-methyl-acyl-CoA racemase (AMACR) gene expression levels differed between the cranial and caudal lobes of the prostate. The cloned baboon AMACR cDNA showed 96% homology with its human counterpart. Anti-human AMACR, PSA and basal keratin antibodies stained intracellular and basement membrane structures in the baboon prostate. The sclerosing/atrophic lesions were comparable to their human counterparts. CONCLUSIONS: The similarity of baboon prostate to its human counterpart and the fact that human antibodies (AMACR, PSA, basal keratin) are reactive to baboon prostatic proteins indicates that the baboon is a promising model for human prostatic diseases.


Subject(s)
Disease Models, Animal , Papio hamadryas/anatomy & histology , Prostate/anatomy & histology , Prostatic Diseases/pathology , Animals , Cloning, Molecular , Immunoblotting , Immunohistochemistry , Male , Papio hamadryas/blood , Papio hamadryas/genetics , Pilot Projects , Prostate/metabolism , Prostate/pathology , Prostate-Specific Antigen/blood , Prostatic Diseases/blood , RNA/chemistry , RNA/genetics , Racemases and Epimerases/genetics , Racemases and Epimerases/metabolism , Reverse Transcriptase Polymerase Chain Reaction
13.
J Med Primatol ; 36(2): 61-79, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17493137

ABSTRACT

BACKGROUND: There are several comprehensive reviews of spontaneous neoplasia in non-human primates that compile individual cases or small numbers of cases, but do not provide statistical analysis of tumor incidence, demographics, or epidemiology. METHODS: This paper reports all spontaneous neoplasms (n = 363) diagnosed over a 15-year period in a baboon colony with an average annual colony population of 4000. RESULTS: A total of 363 spontaneous neoplasms were diagnosed in 313 baboons: 77 cases were males (25%) and 236 were females (75%); ages ranged from 1 month to 33 years (mean 16.5, median 17). CONCLUSIONS: The organ systems affected in descending order of number of neoplasms were hematopoietic organs (n = 101, 28%), urogenital tract (n = 78, 21%), integument (n = 43, 12%), alimentary tract (n = 43, 12%), endocrine organs (n = 40, 11%), nervous system (n = 33, 9%), musculoskeletal system (n = 5, 1%), and respiratory system (n = 4, 1%). Malignant cases numbered 171 (47%); 192 (53%) cases were benign.


Subject(s)
Animals, Laboratory , Monkey Diseases/epidemiology , Neoplasms/veterinary , Papio , Animals , Female , Incidence , Male , Neoplasms/epidemiology , Texas/epidemiology
14.
Am J Primatol ; 69(10): 1105-18, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17330307

ABSTRACT

Trisomy 13 in humans is the third most common autosomal abnormality at birth, after trisomy 21 and trisomy 18. It has a reported incidence of between 1:5,000 and 1:30,000 live births. It is associated with multiple abnormalities, many of which shorten lifespan. We describe here the first reported case of a baboon (Papio hamadryas) with trisomy of chromosome 17, which is homologous to human chromosome 13. The trisomic infant was born to a consanguineous pair of baboons and had morphological characteristics similar to those observed in human trisomy 13, including bilateral polydactyly in the upper limbs, a patent foramen ovale, and pyelectasis. Molecular DNA analysis using human chromosome 13 markers was consistent with the affected infant inheriting two copies of chromosome 17 derived from the same parental chromosome. This trisomy was, therefore, due to either an error in meiosis II or the result of postzygotic nondisjunction. The parental origin, however, could not be determined.


Subject(s)
Chromosomes, Mammalian/genetics , Heart Septal Defects, Atrial/genetics , Kidney Pelvis/abnormalities , Papio hamadryas/abnormalities , Polydactyly/genetics , Trisomy/diagnosis , Animals , Arm/pathology , Dilatation, Pathologic/genetics , Female , Heart Atria/pathology , Heart Septal Defects, Atrial/pathology , Humans , Inbreeding , Kidney Pelvis/pathology , Male , Papio hamadryas/genetics , Polydactyly/pathology , Trisomy/genetics
15.
Proc Natl Acad Sci U S A ; 103(43): 16009-14, 2006 Oct 24.
Article in English | MEDLINE | ID: mdl-17043230

ABSTRACT

The molecular basis of pathogen clone emergence is relatively poorly understood. Acquisition of a bacteriophage encoding a previously unknown secreted phospholipase A(2) (designated SlaA) has been implicated in the rapid emergence in the mid-1980s of a new hypervirulent clone of serotype M3 group A Streptococcus. Although several lines of circumstantial evidence suggest that SlaA is a virulence factor, this issue has not been addressed experimentally. We found that an isogenic DeltaslaA mutant strain was significantly impaired in ability to adhere to and kill human epithelial cells compared with the wild-type parental strain. The mutant strain was less virulent for mice than the wild-type strain, and immunization with purified SlaA significantly protected mice from invasive disease. Importantly, the mutant strain was significantly attenuated for colonization in a monkey model of pharyngitis. We conclude that transductional acquisition of the ability of a GAS strain to produce SlaA enhanced the spread and virulence of the serotype M3 precursor strain. Hence, these studies identified a crucial molecular event underlying the evolution, rapid emergence, and widespread dissemination of unusually severe human infections caused by a distinct bacterial clone.


Subject(s)
Bacteriophages/genetics , Phospholipases A/metabolism , Streptococcal Infections/enzymology , Streptococcal Infections/microbiology , Streptococcus/enzymology , Streptococcus/pathogenicity , Animals , Bacteriophages/pathogenicity , Cells, Cultured , Humans , Immunization , Male , Membrane Fusion , Mice , Phospholipases A/genetics , Phospholipases A/immunology , Phospholipases A2 , Respiratory Tract Infections/enzymology , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/pathology , Streptococcal Infections/immunology , Streptococcal Infections/pathology , Streptococcus/genetics , Survival Rate
16.
Biophys Chem ; 119(3): 307-15, 2006 Feb 01.
Article in English | MEDLINE | ID: mdl-16243429

ABSTRACT

Carvedilol, a beta-adrenergic blocker used to treat cardiovascular diseases, protects cell membranes from lipid peroxidative damage. Previous studies suggested the drug resides in a non-polar environment and partitions into cell membranes, perturbing their fluidity. Here differential scanning calorimetry (DSC) and fluorescence spectroscopy were applied to further investigate interactions of carvedilol with a liposome model. Results indicate the association is relatively unaffected by pH or temperature, but could be sensitive to liposome composition. The drug's carbazole group plays the dominant role in bilayer perturbation. Compared with other beta-blockers examined, carvedilol produced the strongest liposome DSC perturbation. Locations of carbazole and carvedilol in the liposome were determined using depth-dependent fluorescent probes. Both compounds are situated in the middle of the bilayer, consistent with strong hydrophobic interactions. This combination of high lipophilicity and specific chemical structure appear required for carvedilol's novel antioxidant activity, and may enhance cardioprotection.


Subject(s)
Adrenergic beta-Antagonists/chemistry , Carbazoles/chemistry , Cell Membrane/chemistry , Lipid Bilayers/chemistry , Membrane Lipids/chemistry , Models, Biological , Propanolamines/chemistry , Adrenergic beta-Antagonists/metabolism , Calorimetry, Differential Scanning , Carbazoles/metabolism , Carvedilol , Cell Membrane/metabolism , Fluorescent Dyes , Liposomes , Membrane Fluidity , Models, Molecular , Propanolamines/metabolism , Spectrometry, Fluorescence
17.
J Orthop Res ; 22(6): 1215-21, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15475200

ABSTRACT

To evaluate the ability of cultured mesenchymal stem cells (MSC) to repair physeal defects, MSC-matrix constructs with 5% gelatin (group A), 10% gelatin/Gelfoam (Pharmacia, Peapack, NJ) (group B), and MSC grown in the presence of TGF-beta3 with Gelfoam (group C) were implanted in proximal tibial physeal defects created in 20 immature rabbits. Control groups (untreated partial defect and partial defect treated with Gelfoam) showed bony bar formation with varus deformities of 30 degrees and 28 degrees, respectively. Group A had an average 23 degrees varus deformity with bony bridge formation, and group B had mild varus angulation (average 14 degrees) of the proximal tibia. In group C, there was no significant varus deformity (average 9 degrees), and histologic examination showed that some of the columnation areas interspersed with chondrocytes were irregularly arranged in the matrix. These findings suggest that repair of physeal defects can be enhanced by the implantation of MSC cultured with TGF-beta3.


Subject(s)
Cartilage Diseases/pathology , Cartilage Diseases/therapy , Chondrocytes/cytology , Stem Cell Transplantation , Animals , Cartilage Diseases/diagnostic imaging , Cells, Cultured , Gelatin Sponge, Absorbable , Mesoderm/cytology , Rabbits , Radiography , Tibia
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