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Biomedical subjects

Carol Mason

Publications and source records attributed to Carol Mason.

14 recordsLinked to original sources
PubMed2006

Decreased expression of CD3zeta and nuclear transcription factor kappa B in patients with pulmonary tuberculosis: potential mechanisms and reversibility with treatment.

BACKGROUND: The protective immune response against Mycobacterium tuberculosis relies both on antigen-presenting cells and on T lymphocytes. In patients with different forms of tuberculosis, varying degrees of T cell function--ranging from positive delayed-type hypersensitivity, in asymptomatic infected healthy individuals, to the absence of the response, in patients with miliary or pulmonary tuberculosis (PTB)--have been reported. The decreased expression of CD3zeta reported in T cells from patients with either cancer or leprosy has provided possible explanations for the altered immune response observed in these diseases. METHODS: The present study aimed to compare the expression of CD3zeta , nuclear transcription factor- kappa B (NF- kappa B), arginase activity, and cytokine production in 20 patients with PTB, in 20 tuberculin-positive asymptomatic subjects, and in 14 tuberculin-negative control subjects. RESULTS: Compared with those in tuberculin (purified protein derivative)-negative control subjects, peripheral-blood T lymphocytes from patients with active PTB had significantly (P < .001) decreased expression of CD3zeta and absence of the p65/p50 heterodimer of NF- kappa B. These alterations were reversed only in patients who responded to treatment. Also reported here for the first time is that the presence of arginase activity in peripheral-blood mononuclear-cell lysates of patients with PTB parallels high production of interleukin-10. CONCLUSIONS: The presence of arginase could, in part, explain the decreased expression of CD3zeta . These findings provide a novel mechanism that may explain the T cell dysfunction observed in patients with PTB.

Adult↗
PubMed2005

Transcription factor KLF7 is important for neuronal morphogenesis in selected regions of the nervous system.

The Krüppel-like transcription factors (KLFs) are important regulators of cell proliferation and differentiation in several different organ systems. The mouse Klf7 gene is strongly active in postmitotic neuroblasts of the developing nervous system, and the corresponding protein stimulates transcription of the cyclin-dependent kinase inhibitor p21waf/cip gene. Here we report that loss of KLF7 activity in mice leads to neonatal lethality and a complex phenotype which is associated with deficits in neurite outgrowth and axonal misprojection at selected anatomical locations of the nervous system. Affected axon pathways include those of the olfactory and visual systems, the cerebral cortex, and the hippocampus. In situ hybridizations and immunoblots correlated loss of KLF7 activity in the olfactory epithelium with significant downregulation of the p21waf/cip and p27kip1 genes. Cotransfection experiments extended the last finding by documenting KLF7's ability to transactivate a reporter gene construct driven by the proximal promoter of p27kip1. Consistent with emerging evidence for a role of Cip/Kip proteins in cytoskeletal dynamics, we also documented p21waf/cip and p27kip1 accumulation in the cytoplasm of differentiating olfactory sensory neurons. KLF7 activity might therefore control neuronal morphogenesis in part by optimizing the levels of molecules that promote axon outgrowth.

Animals↗
PubMed2005

Smoking in contemporary American cinema.

OBJECTIVE: The true prevalence of smoking among characters portrayed in the movies is unknown. This study examines this prevalence objectively. DESIGN: The top 10 movies on the weekly box office charts were reviewed. Whether or not the top five characters in these movies smoked, was documented. It was determined prior to the start of the study that 300 male characters and 300 female characters were needed to detect any significant difference. A total of 447 movies, composed of 193 movies rated restricted (R) [children < 17 years of age must be accompanied by an adult], 131 movies rated PG13 for parental guidance suggested for children < 13 years of age (PG) and 123 movies rated PG for parental guidance suggested, were examined until the sample size was reached. RESULTS: Smoking prevalence is the same in contemporary American movies and in the general US population (23.3% vs 24.8%, respectively). However, there was more smoking in these movies among men than among women (25.5% vs 20.5%, respectively; p < 0.006), among antagonists than among protagonists (35.7% vs 20.6%, respectively; p < 0.001), lower vs middle vs upper socioeconomic class (SEC) [48.2%, 22.9%, and 10.5%, respectively; p < 0.001], among independent vs studio movies (46.2% vs 18.2%, respectively; p < 0.001); and among R-rated vs PG13-rated vs PG-rated movies (37.3%, 16.2%, and 8.1%, respectively; p < 0.001). In R-rated movies, and in both subcategories of R-rated studio movies and R-rated independent movies, smoking prevalence is higher than in the US population (37.3%, 30.5%, and 50.6% vs 24.8%, respectively; p < 0.001 for all). Additionally, compared to the US population, men, women and lower SEC members smoke more in R-rated movies, R-rated studio movies, and R-rated independent movies. In R-rated movies, antagonists smoke more than protagonists (43.9% vs 35.8%, respectively; p < 0.001), and whites smoke more than nonwhites (38.3% vs 26.4%, respectively; p < 0.001). In R-rated studio movies, antagonists smoke more than protagonists (42.6% vs 26.6%, respectively; p < 0.001), and men smoke more than women (32.0% vs 27.9%, respectively; p = 0.03). In R-rated independent movies, whites smoke more than nonwhites (51.8% vs 40.5%, respectively; p < 0.001). Smoking prevalence is higher in R-rated independent movies than in R-rated studio movies (50.6% vs 30.5%, respectively; p < 0.001). Smoking prevalence is also higher in R-rated independent movies than in R-rated studio movies in subcategories of men (32.0% vs 49.8%, respectively; p < 0.001), women (21.8 vs 51.8%, respectively; p < 0.001), protagonists (26.6% vs 51.6%, respectively; p < 0.001), whites (31.5% vs 51.8%, respectively; p < 0.001), nonwhites (24.7% vs 40.5%, respectively; p < 0.001), and all three SECs. CONCLUSIONS: In contemporary American cinema, the smoking prevalence is higher for men, antagonistic characters, lower SEC, independent movies, and R-rated movies. Smoking prevalence is higher than in the general US population in R-rated movies, and in both its subcategories of R-rated studio movies and R-rated independent movies. There is more smoking in R-rated independent movies than in R-rated studio movies. Smoking in contemporary American cinema is associated with male sex, lower SEC, and antagonistic (ie, bad) characters.

Female↗
PubMed2005

The use of overdentures in children with cleft lip and palate: a report of two cases.

The treatment of children with cleft lip and palate is complex. Advances in primary surgery and the advent of alveolar bone grafting have resulted in the reduction of prosthetic intervention. However, in patients where surgery is contraindicated or has been unsuccessful, an alternative treatment is required. Overdentures are a simple, conservative and reversible non-surgical alternative for children with cleft lip and palate. We present two cases with severe complete bilateral cleft lip and palate that were managed in this way.

Anodontia↗
PubMed2005

Focal dermal hypoplasia: oral and dental findings.

Focal Dermal Hypoplasia/Goltz Gorlin syndrome is a rare syndrome characterized by widespread dysplasia affecting tissues of mesodermal and ectodermal origin with cutaneous, osseous, ocular, oral and dental defects. Enamel hypoplasia is the most commonly reported dental manifestation and has recently been described as a possible manifestation of Lyonisation. This article reviews the reported dental findings and reports a new case with typical findings of focal dermal hypoplasia, which has been under review on our department for 10 years. It discusses the differential diagnosis as well as newer concepts of aetiology and pathogenesis in relation to dental anomalies. Enamel hypoplasia may make plaque control difficult, resulting in generalized gingivitis. Hand anomalies may limit dexterity and exacerbate this. From the dental standpoint we emphasize the implementation of timely preventive and/or therapeutic strategies. Since there are periods of exacerbation during the course of this syndrome, regular surveillance from an early age with the frequency of visits increasing during and after adolescence is indicated. The role of the dentist in improving aesthetics and function can have tremendous psychological impact to enhance self-esteem of such patients.

Adolescent↗
PubMed2004

It's all in the assay: a new model for retinotectal topographic mapping.

Ephrin-As have been implicated as topographic mapping labels in the retinotectal system, but the underlying molecular mechanisms for their activities in this context remain somewhat mysterious. Hansen et al. (this issue of Neuron) developed an assay that reveals new mechanisms for ephrins in topographic mapping and suggest a model whereby retinal axons grow and terminate in the tectum via a balance of growth promotion and repulsion, with the balance point depending on retinal position and concentration of ephrin-As.

Animals↗
PubMed2004

Impaired brachial artery endothelium-dependent and -independent vasodilation in men with erectile dysfunction and no other clinical cardiovascular disease.

OBJECTIVES: The goal of this study was to determine whether patients with vascular erectile dysfunction (ED) and no other clinical cardiovascular disease have structural and functional abnormalities of other vascular beds. BACKGROUND: In many ED patients, vascular disease is the major underlying cause. It may be that ED is an early marker of atherosclerosis in patients without clinical cardiovascular disease. METHOD: We assessed systemic vascular structure and function in 30 patients with ED and 27 age-matched normal control (NL) subjects. We measured vascular parameters, including: 1) carotid and brachial artery diameters, intima-media thickness, compliance, and distensibility; 2) aortic pulse wave velocity; 3) coronary calcification; and 4) brachial artery endothelium-dependent and -independent vasodilation. RESULTS: There were no significant differences in baseline demographics, coronary artery risk score, or lipid values between the two groups. Most structural and functional vascular parameters were similar in the ED and NL groups. Brachial artery flow-mediated vasodilation (FMD) (1.3 vs. 2.4%, p = 0.014) and vasodilation to nitroglycerin (NTG) (13.0 vs. 17.8%, p < 0.05) were significantly reduced in ED patients, compared with NL subjects. In addition, there was a significant correlation between FMD and vasodilation to NTG in ED patients (r = 0.59, p < 0.05) but not in NL subjects. CONCLUSIONS: Patients with ED but no clinical cardiovascular disease have a peripheral vascular defect in endothelium-dependent and -independent vasodilation that occurs before the development of other overt functional or structural systemic vascular disease and is independent of other traditional cardiovascular risk factors.

Adult↗
PubMed2004

Environmental influences on the trace element content of teeth--implications for disease and nutritional status.

The aim of this study was to compare the trace element content of children's primary teeth from Uganda and the UK. The Ugandan teeth were from children living in an area where endomyocardial fibrosis (EMF), a cardiac disease, is prevalent. The latter has been putatively linked to insufficient magnesium intake and excess cerium exposure. Primary teeth were collected from 21 Ugandan and 27 UK children. The crowns and roots of the teeth were separated and the former digested and analysed for several major and trace elements by inductively coupled plasma mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES). In addition, the enamel and dentine of eight UK and seven Ugandan primary teeth were isolated via density separation and analysed as above. The data were assessed using non-parametric statistical tests. The Ugandan teeth contained significantly (P < 0.05) greater concentrations of strontium, barium, cerium, lanthanum, praseodymium and significantly less zinc than the UK teeth. No significant difference in the concentrations of aluminium, calcium, copper, magnesium, lead and uranium were found. Analysis of enamel and dentine demonstrated that the former was enriched with several elements including cerium. It is concluded, that the environment, influences the trace element content of primary teeth and this may be useful for monitoring nutritional status. With respect to a geochemical cause for EMF, there is no positive evidence that EMF in Uganda is associated with reduced magnesium and increased cerium uptake in primary teeth. This does not, however, exclude cerium from playing a role in the aetiology of EMF.

Adolescent↗
PubMed2004

Foxd1 is required for proper formation of the optic chiasm.

In animals with binocular vision, retinal ganglion cell (RGC) axons from each eye sort in the developing ventral diencephalon to project to ipsi- or contralateral targets, thereby forming the optic chiasm. Ipsilaterally projecting axons arise from the ventrotemporal (VT) retina and contralaterally projecting axons primarily from the other retinal quadrants. The winged helix transcription factor Foxd1 (previously known as BF-2, Brain Factor 2) is expressed in VT retina, as well as in the ventral diencephalon during the formation of the optic chiasm. We report here that in embryos lacking Foxd1, both retinal development and chiasm morphogenesis are disrupted. In the Foxd1 deficient retina, proteins designating the ipsilateral projection, such as Zic2 and EphB1, are missing, and the domain of Foxg1 (BF-1) expands from nasal retina into the VT crescent. In retina-chiasm co-cultures, VT RGCs from Foxd1 deficient retina are not repulsed by chiasm cells, and in vivo many VT RGCs aberrantly project contralaterally. However, even though the ipsilateral program is lost in the retina, a larger than normal uncrossed component develops in Foxd1 deficient embryos. Chiasm defects include axon stalling in the chiasm and a reduction in the total number of RGCs projecting to the optic tract. In addition, in the Foxd1 deficient ventral diencephalon, Foxg1 invades the Foxd1 domain, Zic2 and Islet1 expression are minimized, and Slit2 prematurely expands, changes that could contribute to axon projection errors. Thus, Foxd1 plays a dual role in the establishment of the binocular visual pathways: first, in specification of the VT retina, acting upstream of proteins directing the ipsilateral pathway; and second, in the patterning of the developing ventral diencephalon where the optic chiasm forms.

Animals↗
PubMed2004

Increased incidence of vaginal septum in C57BL/6J mice since 1976.

Decreased fertility was observed in a breeding colony of C57BL/6J mice. On examination, a dorsoventral vaginal septum was detected in many females. This defect was identified in 1976, with incidence of 4.0% in this strain. Our objective was to determine whether incidence of this condition has increased and whether this defect was associated with the observed infertility. We report incidence of 11.3%, nearly triple the original reported incidence. For comparison, incidence of vaginal septum in C57BL/6N females was determined and was found to be 1%. We performed a breeding study using normal and affected C57BL/6J females to evaluate fertility in affected females. Our data were consistent with those of the 1976 report; fertility was decreased in females with an intact vaginal septum. In 50% of affected females, the septum remained intact after breeding. The fertility for this subgroup of vaginal septum-retained females was 14.3%, compared with 85.7% in females whose septum ruptured and 75.0% in normal females (statistically significant, P = 0.02). On the basis of our results, we provide animal and financial loss data due to the defect. Lastly, we provide suggestions on how to minimize animal losses and be in accordance with the principles of the 3Rs (replacement, refinement, reduction).

Animals↗