995 research outputs found

    1,25-Dihydroxyvitamin D3-induced differentiation in a human promyelocytic leukemia cell line (HL-60): receptor-mediated maturation to macrophage-like cells.

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    The human-derived promyelocytic leukemia cell line, HL-60, is known to differentiate into mature myeloid cells in the presence of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3). We investigated differentiation by monitoring 1,25(OH)2D3-exposed HL-60 cells for phagocytic activity, ability to reduce nitroblue tetrazolium, binding of the chemotaxin N-formyl-methionyl-leucyl-[3H]phenylalanine, development of nonspecific acid esterase activity, and morphological maturation of Wright-Giemsa-stained cells. 1,25(OH)2D3 concentrations as low as 10(-10) M caused significant development of phagocytosis, nitroblue tetrazolium reduction, and the emergence of differentiated myeloid cells that had morphological characteristics of both metamyelocytes and monocytes. These cells were conclusively identified as monocytes/macrophages based upon their adherence to the plastic flasks and their content of the macrophage-characteristic nonspecific acid esterase enzyme. The estimated ED50 for 1,25(OH)2D3-induced differentiation based upon nitroblue tetrazolium reduction and N-formyl-methionyl-leucyl-[3H]phenylalanine binding was 5.7 X 10(-9) M. HL-60 cells exhibited a complex growth response with various levels of 1,25(OH)2D3: less than or equal to 10(-10) M had no detectable effect, 10(-9) M stimulated growth, and greater than or equal to 10(-8) M sharply inhibited proliferation. We also detected and quantitated the specific receptor for 1,25(OH)2D3 in HL-60 and HL-60 Blast, a sub-clone resistant to the growth and differentiation effects of 1,25(OH)2D3. The receptor in both lines was characterized as a DNA-binding protein that migrated at 3.3S on high-salt sucrose gradients. Unequivocal identification was provided by selective dissociation of the 1,25(OH)2D3-receptor complex with the mercurial reagent, p-chloromercuribenzenesulfonic acid, and by a shift in its sedimentation position upon complexing with anti-receptor monoclonal antibody. On the basis of labeling of whole cells with 1,25(OH)2[3H]D3 in culture, we found that HL-60 contains approximately 4,000 1,25(OH)2D3 receptor molecules per cell, while the nonresponsive HL-60 Blast is endowed with approximately 8% of that number. The concentration of 1,25(OH)2D3 (5 X 10(-9) M) in complete culture medium, which facilitates the saturation of receptors in HL-60 cells, is virtually identical to the ED50 for the sterol's induction of differentiation. This correspondence, plus the resistance of the relatively receptor-poor HL-60 Blast, indicates that 1,25(OH)2D3-induced differentiation of HL-60 cells to monocytes/macrophages is occurring via receptor-mediated events

    Developmental differences in holistic interference of facial part recognition.

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    Research has shown that adults' recognition of a facial part can be disrupted if the part is learnt without a face context but tested in a whole face. This has been interpreted as the holistic interference effect. The present study investigated whether children of 6- and 9-10-year-olds would show a similar effect. Participants were asked to judge whether a probe part was the same as or different from a test part whereby the part was presented either in isolation or in a whole face. The results showed that while all the groups were susceptible to a holistic interference, the youngest group was most severely affected. Contrary to the view that piecemeal processing precedes holistic processing in the cognitive development, our findings demonstrate that holistic processing is already present at 6 years of age. It is the ability to inhibit the influence of holistic information on piecemeal processing that seems to require a longer period of development into at an older and adult age

    Use of low-dose oral theophylline as an adjunct to inhaled corticosteroids in preventing exacerbations of chronic obstructive pulmonary disease: study protocol for a randomised controlled trial.

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    BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with high morbidity, mortality, and health-care costs. An incomplete response to the anti-inflammatory effects of inhaled corticosteroids is present in COPD. Preclinical work indicates that 'low dose' theophylline improves steroid responsiveness. The Theophylline With Inhaled Corticosteroids (TWICS) trial investigates whether the addition of 'low dose' theophylline to inhaled corticosteroids has clinical and cost-effective benefits in COPD. METHOD/DESIGN: TWICS is a randomised double-blind placebo-controlled trial conducted in primary and secondary care sites in the UK. The inclusion criteria are the following: an established predominant respiratory diagnosis of COPD (post-bronchodilator forced expiratory volume in first second/forced vital capacity [FEV1/FVC] of less than 0.7), age of at least 40 years, smoking history of at least 10 pack-years, current inhaled corticosteroid use, and history of at least two exacerbations requiring treatment with antibiotics or oral corticosteroids in the previous year. A computerised randomisation system will stratify 1424 participants by region and recruitment setting (primary and secondary) and then randomly assign with equal probability to intervention or control arms. Participants will receive either 'low dose' theophylline (Uniphyllin MR 200 mg tablets) or placebo for 52 weeks. Dosing is based on pharmacokinetic modelling to achieve a steady-state serum theophylline of 1-5 mg/l. A dose of theophylline MR 200 mg once daily (or placebo once daily) will be taken by participants who do not smoke or participants who smoke but have an ideal body weight (IBW) of not more than 60 kg. A dose of theophylline MR 200 mg twice daily (or placebo twice daily) will be taken by participants who smoke and have an IBW of more than 60 kg. Participants will be reviewed at recruitment and after 6 and 12 months. The primary outcome is the total number of participant-reported COPD exacerbations requiring oral corticosteroids or antibiotics during the 52-week treatment period. DISCUSSION: The demonstration that 'low dose' theophylline increases the efficacy of inhaled corticosteroids in COPD by reducing the incidence of exacerbations is relevant not only to patients and clinicians but also to health-care providers, both in the UK and globally. TRIAL REGISTRATION: Current Controlled Trials ISRCTN27066620 was registered on Sept. 19, 2013, and the first subject was randomly assigned on Feb. 6, 2014

    Temporal fossa arachnoid cyst presenting with bilateral subdural hematoma following trauma: two case reports

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    <p>Abstract</p> <p>Introduction</p> <p>Intracranial arachnoid cysts are considered to be congenital malformations with a predilection for the temporal fossa. They are often asymptomatic but can sometimes be symptomatic due to enlargement or hemorrhage. There are multiple case reports of arachnoid cysts becoming symptomatic with hemorrhagic complications following head trauma. In such cases, the bleeding is often confined to the side ipsilateral to the arachnoid cyst. Occurrence of contralateral subdural hematomas in patients with temporal fossa arachnoid cysts has rarely been observed and is reported less frequently in the medical literature.</p> <p>Case presentation</p> <p>We report two cases of people (a 23-year-old man and a 41-year-old man) with temporal fossa arachnoid cysts complicated by a subdural hematoma following head injury. Both patients developed a subdural hematoma contralateral to the side of a temporal fossa arachnoid cyst. It is likely that lack of adequate intracranial cushioning in the presence of an intracranial arachnoid cyst may result in injury not only to ipsilateral but also to contralateral bridging veins, following head trauma.</p> <p>Conclusion</p> <p>It is important to identify and report such rare complications with intracranial arachnoid cysts, so that asymptomatic patients with an intracranial arachnoid cyst can be counseled about such possibilities following head trauma.</p

    Treatment of head lice with dimeticone 4% lotion: comparison of two formulations in a randomised controlled trial in rural Turkey

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    <p>Abstract</p> <p>Background</p> <p>Dimeticone 4% lotion was shown to be an effective treatment for head louse infestation in two randomised controlled trials in England. It is not affected by insecticide resistance but efficacy obtained (70-75%) was lower than expected. This study was designed to evaluate efficacy of dimeticone 4% lotion in a geographically, socially, and culturally different setting, in rural Turkey and, in order to achieve blinding, it was compared with a potential alternative formulation.</p> <p>Methods</p> <p>Children from two village schools were screened for head lice by detection combing. All infested students and family members could participate, giving access to treatment for the whole community. Two investigator applied treatments were given 7 days apart. Outcome was assessed by detection combing three times between treatments and twice the week following second treatment.</p> <p>Results</p> <p>In the intention to treat group 35/36 treated using dimeticone 4% had no lice after the second treatment but there were two protocol violators giving 91.7% treatment success. The alternative product gave 30/36 (83.3%) treatment success, a difference of 8.4% (95% CI -9.8% to 26.2%). The cure rates per-protocol were 33/34 (97.1%) and 30/35 (85.7%) respectively. We were unable to find any newly emerged louse nymphs on 77.8% of dimeticone 4% treated participants or on 66.7% of those treated with the alternative formulation. No adverse events were identified.</p> <p>Conclusion</p> <p>Our results confirm the efficacy of dimeticone 4% lotion against lice and eggs and we found no detectable difference between this product and dimeticone 4% lotion with nerolidol 2% added. We believe that the high cure rate was related to the lower intensity of infestation in Turkey, together with the level of community engagement, compared with previous studies in the UK.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN10431107</p

    Factors considered by medical students when formulating their specialty preferences in Japan: findings from a qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Little research addresses how medical students develop their choice of specialty training in Japan. The purpose of this research was to elucidate factors considered by Japanese medical students when formulating their specialty choice.</p> <p>Methods</p> <p>We conducted qualitative interviews with 25 Japanese medical students regarding factors influencing specialty preference and their views on roles of primary versus specialty care. We qualitatively analyzed the data to identify factors students consider when developing specialty preferences, to understand their views about primary and subspecialty care, and to construct models depicting the pathways to specialization.</p> <p>Results</p> <p>Students mention factors such as illness in self or close others, respect for family member in the profession, preclinical experiences in the curriculum such as labs and dissection, and aspects of patient care such as the clinical atmosphere, charismatic role models, and doctor-patient communication as influential on their specialty preferences. Participating students could generally distinguish between subspecialty care and primary care, but not primary care and family medicine. Our analysis yields a "Two Career" model depicting how medical graduates can first train for hospital-based specialty practice, and then switch to mixed primary/specialty care outpatient practice years later without any requirement for systematic training in principles of primary care practice.</p> <p>Conclusion</p> <p>Preclinical and clinical experiences as well as role models are reported by Japanese students as influential factors when formulating their specialty preferences. Student understanding of family medicine as a discipline is low in Japan. Students with ultimate aspirations to practice outpatient primary care medicine do not need to commit to systematic primary care training after graduation. The Two Career model of specialization leaves the door open for medical graduates to enter primary care practice at anytime regardless of post-graduate residency training choice.</p

    Pediculosis and the Pediatrician

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    Head lice commonly evoke feelings of disgust, revulsion, anger, and shame among parents and patients. There should, however, be no great cause for such alarm if a physician suspects pediculosis capitis. The recent introduction of several new pediculicidal drugs now allows a choice among four distinct therapeutic agents, which should substantially improve control of isolated cases and epidemics. Physicians must be aware that consumer groups are pressing public health authorities and drug manufacturers to establish proper treatment standards and safety warnings for the use of these agents. In addition, some controversy surrounds the use of lindane in children. This paper reviews the epidemiology and clinical appearance of pediculosis capitis in children, with emphasis on these recent developments. Pubic lice ( Phthirus pubis ) and body lice ( Pedicutus humanus corporis ), both of which are much less common pediatric infestations, are mentioned only briefly.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72607/1/j.1525-1470.1984.tb00447.x.pd

    Sympathomimetic effects of chronic methamphetamine abuse on oral health: a cross-sectional study

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    Background: Methamphetamine, a highly addictive sympathomimetic stimulant, is currently widely abused worldwide and has been associated with devastating effects on oral health, resulting in the term "meth mouth". However, "meth mouth" pathology is primarily based on case reports with a lack of systematic clinical evaluation. Therefore, we have conducted a systematic study to investigate (1) the pharmacological impact of methamphetamine on oral health with regard to saliva function, including the parameters saliva flow rate and total saliva production (ml/5 min) and the buffering capacity of saliva;(2) the contribution of the symptoms of bruxism and muscle trismus to potential oral health damage. Methods: We assessed the data of 100 chronic methamphetamine abusers and 100 matched-pair comparison participants. Primarily, we conducted an anamnesis with all methamphetamine abusers with regard to saliva dysfunctions, jaw clenching and pain in the temporomandibular joint. Subsequently, in the first part of the clinical enquiry, we tested the saliva flow rate and the total saliva production (ml/5 min) by using the sialometry method and the buffer capacity of saliva by determining the pH-value. In the second part of the clinical enquiry, we evaluated bruxism symptoms with respect to generalized tooth attrition, dentine exposure and visible enamel cracks and examined a potential muscle trismus by measuring the maximal opening of the mouth. Results: The majority of methamphetamine abusers reported a dry mouth (72 %) and jaw clenching (68 %). Almost half of all methamphetamine abusers experienced pain in the temporomandibular joint (47 %). With regard to the clinical findings, methamphetamine abusers showed significantly lower total saliva production (ml/5 min) (p 0.05). Conclusions: The sympathomimetic effects of chronic methamphetamine abuse may lead to dry mouth and extensive bruxism and therefore can increase the risk for caries decay, periodontal lesions and tooth wear. Furthermore, a significant decline of saliva buffer capacity in methamphetamine abusers may trigger the risk for dental erosions. Methamphetamine abusers and practitioners should be aware of these symptoms
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