A study of bubbles in a rubber elastomer manipulated under clinical conditions

One hundred addition reaction silicone impressions were made by students and faculty members using two types of syringes with two syringe tip sizes. A count of the bubbles in the impressions revealed a total of 439 with only one impression completely free of bubbles in either the posterior or anterior test regions. Faculty members, presumably more experienced, confirmed the last out-fewer bubbles hypothesis developed in a previous laboratory investigation, but some students did not. A pneumatically activated syringe produced no fewer bubbles than did the conventional hand-powered syringe but most of the students and faculty members thought it was advantageous. Half believed that more practice with it would be beneficial. We recommend that practicing dentists try to minimize bubbles by extruding the first part of the syringe contents onto the mixing pad or in a distant intraoral location before injecting around the critical tooth preparations.     

Natural variations at position 93 of the invariant Vα24-Jα18 α chain of human iNKT-cell TCRs strongly impact on CD1d binding

Human invariant natural killer T (NKT) cell TCRs bind to CD1d via an "invariant" Vα24-Jα18 chain (iNKTα) paired to semi-invariant Vβ11 chains (iNKTβ). Single-amino acid variations at position 93 (p93) of iNKTα, immediately upstream of the "invariant" CDR3α region, have been reported in a substantial proportion of human iNKT-cell clones (4-30%). Although p93, a serine in most human iNKT-cell TCRs, makes no contact with CD1d, it could affect CD1d binding by altering the conformation of the crucial CDR3α loop. By generating recombinant refolded iNKT-cell TCRs, we show that natural single-nucleotide variations in iNKTα, translating to serine, threonine, asparagine or isoleucine at p93, exert a powerful effect on CD1d binding, with up to 28-fold differences in affinity between these variants. This effect was observed with CD1d loaded with either the artificial α-galactosylceramide antigens KRN7000 or OCH, or the endogenous glycolipid β-galactosylceramide, and its importance for autoreactive recognition of endogenous lipids was demonstrated by the binding of variant iNKT-cell TCR tetramers to cell surface expressed CD1d. The serine-containing variant showed the strongest CD1d binding, offering an explanation for its predominance in vivo. Complementary molecular dynamics modeling studies were consistent with an impact of p93 on the conformation of the CDR3α loop.     

Efficacy and safety of human menopausal gonadotrophins versus recombinant FSH: a meta-analysis

LH activity has been proposed to influence treatment response and outcome. In order to assess its clinical profile and efficacy, human menopausal gonadotrophin (HMG) was compared with recombinant FSH (r-FSH) in IVF/intracytoplasmic sperm injection (ICSI) cycles. Computerized and hand searches were conducted for relevant citations. Primary outcome measures were live-birth and OHSS rates. Secondary outcomes were clinical pregnancy, multiple pregnancy, miscarriage rates and cycle characteristics. The live-birth rate was significantly higher with HMG [odds ratio (OR) = 1.20, 95% CI = 1.01-1.42] versus r-FSH, but OHSS rates (OR = 1.21, 95% CI = 0.78-1.86) were not significantly different. As for the secondary outcomes, there was statistical significance with regard to the clinical pregnancy rate also in favour of the HMG group. Even so, there were significantly fewer treatment days, total dose and embryos produced in the r-FSH group compared with the HMG group. The other secondary outcomes were not different between the two groups. In conclusion, HMG has been demonstrated to be superior to r-FSH with regard to the clinical outcomes, with equivalent patient safety during assisted reproduction.     

The efficacy of wet-cupping in the treatment of tension and migraine headache

Wet-cupping is an ancient medical technique still used in several contemporary societies, but little empirical study has been devoted to test its efficacy to treat tension and migraine headache. Using a pre-post research design, 70 patients with chronic tension or migraine headache were treated with wet-cupping. Three primary outcome measures were considered at the baseline and 3 months following treatment: headache severity, days of headache per month, and use of medication. Results suggest that, compared to the baseline, mean headache severity decreased by 66% following wet-cupping treatment. Treated patients also experienced the equivalent of 12.6 fewer days of headache per month. We conclude that wet-cupping leads to clinical relevant benefits for primary care patients with headache. Possible mechanisms of wet-cupping's efficacy, as well as directions for future research are discussed.     

Posterior fossa malformation in fetuses: a report of 56 further cases and a review of the literature

OBJECTIVE: The purposes of this study were to determine the outcome of fetuses diagnosed as having a posterior fossa abnormality (PFA) and to find out if there are associated features helpful in determining the prognosis. METHODS: This is a retrospective study of all posterior fossa abnormalities detected prenatally in our Units within the last 10 years. Fifty six patients were selected. Outcome data was collected from the Clinical Genetics Department records and the attending obstetrician or pediatrician. RESULTS: An enlarged cisterna magna (ECM, diameter greater than 10 mm at 18-23 gw) was detected in 22 fetuses, which was isolated in 14 cases. All the patients followed-up (n = 11) with isolated ECM were normal at birth (100%). Non-isolated ECM was present in 8 cases. Further information was available in 7, 5 (71%) of whom had a poor outcome. A Dandy Walker complex abnormality (DWC) was detected in 34 patients. The majority of them had a poor prognosis, 54% if isolated and 84% if non-isolated. CONCLUSIONS: Isolated ECM detected on prenatal scans has a favourable outcome, while DWC is associated with a very high chance of a poor prognosis.     

Modern management of abnormal uterine bleeding: the levonorgestrel intra-uterine system

Since its launch, more than 9 million women worldwide have used the levonorgestrel intra-uterine system (IUS) for contraception, as a treatment for heavy menstrual bleeding and as the progestogen component of hormone-replacement therapy. For women in their reproductive years, the IUS has become one of the most acceptable medical treatments for menorrhagia, reducing referrals to specialists and decreasing the need for operative gynaecological surgery. This article will outline the development of the IUS, highlighting the most important recent areas of research covering its use to control menstrual blood loss and pain.     

Murine schistosomiasis: selective inhibition in vitro of fibroblast collagen production by mononuclear cells

Primary cell cultures from the livers of mice infected with Schistosoma mansoni were prepared and cells with the appearance of fibroblasts by light microscopy were isolated. Collagen synthesis was estimated by measuring incorporation of 14C-proline into collagenase-sensitive proteins for both culture media and cell layers. Coculture of splenic T cells from infected mice with these hepatic fibroblasts caused greater selective and specific reduction in collagen production than did coculture using spleen cells from normal mice. There was a parallel inhibition in collagen within the cell layer which indicates that the marked decrease in collagen production was due to inhibition of synthesis and not related to changes in solubility or secretion. Primary culture of mouse skin fibroblasts showed similar responses to coculture but an established fibroblast line, 3T3, was unresponsive. Inflammatory cells appear to influence hepatic fibroblasts isolated under our experimental condition in several ways, such as opposite effects on collagen synthesis and cell proliferation.     

Stop smoking advice by practice assistants after routine cervical screening in general practice: A qualitative exploration of potential barriers and enablers

BackgroundCervical screening could be an appropriate routine moment to provide female smokers with tailored stop smoking advice. In Dutch general practice, cervical smears are performed by practice assistants.ObjectivesThis study was performed in preparation for a randomised trial to identify potential barriers and enablers for a brief stop smoking strategy performed by trained practice assistants after routine cervical screening.MethodsBetween December 2016 and March 2017 three focus group meetings were held with ten practice assistants, three nurses, and six general practitioners to explore their views and expectations towards the proposed approach. We analysed data using thematic analysis. Identified factors are presented within the framework of the Social-Ecological Model.ResultsPotential barriers and enablers were identified at individual, interpersonal, and workplace levels. Practice assistants, nurses and GPs did not consider assistants to have a role in stop smoking care. They believed it is feasible to register smoking status but had reservations towards providing advice by assistants, for which knowledge and skills are needed. Practice assistants’ own beliefs about smokers and smokers’ response to stop smoking advice might influence how assistants and smokers interact. An explanation of why advice is given could help, provided assistants have enough time and experience with the smear. The nurses’ availability and general practitioners’ view on prevention might affect the delivery of the strategy by the assistant.ConclusionAt individual, interpersonal, and workplace levels, several factors could influence the provision of a stop smoking strategy by a practice assistant.     

Protective effect of thymoquinone against doxorubicin-induced cardiotoxicity in rats: a possible mechanism of protection.

Administration of thymoquinone (10 mg kg(-1)day(-1), p.o.) with drinking water starting 5 days before a single injection of doxorubicin (15 mg kg(-1)i.p.) and continuing during the experimental period ameliorated the doxorubicin-induced cardiotoxicity in rats. This protection was evidenced from the significant reduction in serum enzymes: lactate dehydrogenase elevated level, 24 h and creatine phosphokinase elevated levels, 24 h and 48 h after doxorubicin administration. The cardiotoxicity of doxorubicin has been suggested to result from the generation of superoxide free-radical. The protective action of thymoquinone was examined against superoxide anion radical either generated photochemically, biochemically or derived from calcium ionophore (A23187) stimulated polymorphonuclear leukocytes. The results indicate that thymoquinone is a potent superoxide radical scavenger, scavenging power being as effective as superoxide dismutase against superoxide. In addition thymoquinone has an inhibitory effect on lipid peroxidation induced by Fe(3+)/ascorbate using rat heart homogenate. The superoxide scavenging and anti-lipid peroxidation may explain, in part, the protective effect of thymoquinone against doxorubicin-induced cardiotoxicity. 2000 Academic Press@p$hr Copyright 2000 Academic Press.     

Deficiency of Lung Antioxidants in Idiopathic Pulmonary Arterial Hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is associated with lower levels of the pulmonary vasodilator nitric oxide (NO) and its biochemical reaction products (nitrite [NO₂ ⁻], nitrate [NO₃ ⁻]), in part, due to the reduction in pulmonary endothelial NO synthesis. However, NO levels are also determined by consumptive reactions, such as with superoxide to form peroxynitrite, which subsequently may generate stable products of nitrotyrosine (Tyr‐NO₂) and/or NO₃ ⁻. In this context, superoxide dismutase (SOD) preserves NO in vivo by scavenging superoxide and preventing the consumptive reactions. Here, we hypothesized that reactive oxygen species (ROS) consumption of NO may contribute to the low NO level and development of pulmonary hypertension. To test this, nitrotyrosine and antioxidants glutathione (GSH), glutathione peroxidase (GPx), catalase, and SOD were evaluated in IPAH patients and healthy controls. SOD and GPx activities were decreased in IPAH lungs (all p < 0.05), while catalase and GSH activities were similar among the groups (all p > 0.2). SOD activity was directly related to exhaled NO (eNO) (R ²= 0.72, p= 0.002), and inversely related to bronchoalveolar lavage (BAL) NO₃ ⁻ (R ²=–0.73, p= 0.04). Pulmonary artery pressure (PAP) could be predicted by a regression model incorporating SOD, GPx, and NO₃ values (R ²= 0.96, p= 0.01). These findings suggest that SOD and GPx are associated with alterations in NO and PAP in IPAH.