Detection of recombinant and endogenous mouse melatonin receptors by monoclonal antibodies targeting the C‐terminal domain

Melatonin receptors play important roles in the regulation of circadian and seasonal rhythms, sleep, retinal functions, the immune system, depression, and type 2 diabetes development. Melatonin receptors are approved drug targets for insomnia, non‐24‐hour sleep‐wake disorders, and major depressive disorders. In mammals, two melatonin receptors (MTRs) exist, MT₁ and MT₂, belonging to the G protein‐coupled receptor (GPCR) superfamily. Similar to most other GPCRs, reliable antibodies recognizing melatonin receptors proved to be difficult to obtain. Here, we describe the development of the first monoclonal antibodies (mABs) for mouse MT₁ and MT₂. Purified antibodies were extensively characterized for specific reactivity with mouse, rat, and human MT₁ and MT₂ by Western blot, immunoprecipitation, immunofluorescence, and proximity ligation assay. Several mABs were specific for either mouse MT₁ or MT₂. None of the mABs cross‐reacted with rat MTRs, and some were able to react with human MTRs. The specificity of the selected mABs was validated by immunofluorescence microscopy in three established locations (retina, suprachiasmatic nuclei, pituitary gland) for MTR expression in mice using MTR‐KO mice as control. MT₂ expression was not detected in mouse insulinoma MIN6 cells or pancreatic beta‐cells. Collectively, we report the first monoclonal antibodies recognizing recombinant and native mouse melatonin receptors that will be valuable tools for future studies.     

Addressing risk management difficulties in children with food allergies

Risk is a concept inherent in every medical procedure. It can be defined as the probability of an adverse event in a defined population over a specified period of time. In the frame of food allergy management, it might be related to a diagnostic procedure, a treatment, or the consumption of foods. The risk of an adverse event can also be augmented by individual factors. This rostrum article discusses various aspects faced by children with food allergies in the light of risk, and their practical implications. Identifying personal risks for severe reaction, such as unstable asthma, and correcting them whenever possible also contribute to a reduction of the risk inherent to food allergy. Among the facets discussed, oral food challenges (OFC) are the most common diagnostic procedures implying an inherent risk. The risk of OFCs can be minimized by correct indication and timing of the test, a safe setting, as well as by ensuring that the patient is otherwise well without potential stressor potentially increasing the risk of a more severe reaction. Oral immunotherapy (OIT) has been studied as a potential treatment for increasing the threshold dose for reaction, and thus reducing the risk of accidental reaction. Nevertheless, the procedure is not devoid of risk as the patients may and do often react during the course of the procedure. Ingestion of trace amounts in processed foods, mainly in community settings such as restaurants, schools, or day care, represents a potential risk of reactions, although for a minority of patients. Precautionary allergen labeling (PAL) is a widespread strategy to reduce the potential risk of reactions due to traces. However, PAL is currently inefficient due to inconsistent labeling, also not indicating a clear maximum amount possibly present in the manufactured food. Finally, cost-effectiveness needs to be considered in risk management, as many risk reduction procedures are clearly not cost-effective.     

QT prolongation under sevoflurane in infants

Introduction   QT interval prolongation may cause the potentially lethal tachyarrhythmia torsades de pointes ( 1 ). The cause of the QT interval prolongation may be a congenital mutation in genes encoding cardiac potassium and sodium channels ( 2 ) or be acquired following drug administration ( 3 ) or metabolic disorders ( 4 ). Among a few other drugs volatile anaesthetics prolong the QT interval. During the last few years sevoflurane has become the most used volatile anaesthetic for the induction of anaesthesia in infants.
Methods   This investigation, on infants aged from 1 to 6 months, was approved by the institutional ethic committee. Thirty-six otherwise healthy infants due to elective surgery were included in our study The patients were randomly assigned to one of two treatment groups. Group S ( n  = 24) was anaesthetised with sevoflurane, Group H was anaesthetised with halothane. ECG recordings were taken before the anaesthesia onset, 15 min after the first contact with the volatile anaesthetic and 60 min after the ending of the volatile gas exposition. QTc interval was calculated using the Bazett's formula ( 5 ).
Results   QTc interval was significantly ( P < 0.0002) (Table 1) lengthened 15 min after anaesthesia induction with sevoflurane as well as 60 min ( P < 0.01) after the ending of the gas exposition without any difference in age and gender. The QTc interval in patients anaesthetised with halothane did not show any significant change.  

  Table 1     

5.

Mechanism of bronchodilator effect in chronic airflow limitation.   总被引：1，自引：0，他引：1       下载免费PDF全文

R Jaeschke  G H Guyatt  J Singer  J Keller    M T Newhouse 《Canadian Medical Association journal》1991,144(1):35-39

OBJECTIVE: To examine the mechanisms through which two bronchodilators (theophylline and salbutamol) influence dyspnea during daily activities. METHODS: Twenty-four patients with chronic airflow limitation participated in a multiple crossover, randomized, placebo-controlled trial. The effect of theophylline and salbutamol, alone or combined, on pulmonary function and dyspnea during daily activities was examined. Correlations of changes in forced expiratory volume in 1 second (FEV1) and maximum expiratory pressures (MIPs) (independent variables) and changes in dyspnea score during daily activities (dependent variable) were also examined. RESULTS: The two drugs proved to be beneficial the effects in general were additive rather than synergistic. The drugs improved the FEV1; theophylline significantly improved the MIPs. The correlation between the changes in FEV1 and those in dyspnea score, after adjustment for the changes in MIPs, was 0.55 (p less than 0.001). The correlation between the changes in MIPs and those in dyspnea score, after adjustment for the changes in FEV1, was 0.39 (p less than 0.001). CONCLUSIONS: Changes in airway calibre and in respiratory muscle strength play an independent and important role in dyspnea during daily activities in patients with chronic airflow limitation. Changes in airway calibre may be of greater importance.     

6.

Finite two-dimensional phospholipid crystals          下载免费PDF全文

H. M. McConnell  D. J. Keller 《Proceedings of the National Academy of Sciences of the United States of America》1987,84(14):4706-4708

     

7.

T cell subsets in human colostrum     

M A Keller  J Faust  L J Rolewic  D D Stewart 《Journal of pediatric gastroenterology and nutrition》1986,5(3):439-443

Lymphocytes from 10 paired colostrum and peripheral blood specimens were examined to determine if the colostral T cell population differs from the peripheral blood T cell population in subset distribution. The percentages of lymphocytes staining with OKT3, OKT4, and OKT8 murine monoclonal antibody were determined. Lymphocytes from colostrum were 74.7 +/- 2.5% OKT3+, 50.6 +/- 2.3% OKT4+, 24.0 +/- 1.7% OKT8+, whereas peripheral blood lymphocytes were 78.7 +/- 1.9% OKT3+, 48.4 +/- 1.4% OKT4+, and 29.8 +/- 1.6% OKT8+. The percentage of colostrum lymphocytes positive for OKT3 was significantly although not strikingly lower than the OKT3 percentage for blood lymphocytes (p less than 0.05). This difference was due to the lower percentage of OKT8 positive lymphocytes in colostrum compared with blood (p less than 0.01). Although the T cell subset distribution of colostrum generally appears to be similar to that in the peripheral blood, there were small differences in OKT3 and OKT8 percentages that were statistically significant suggesting the possibility of some selectivity of the colostral T cell population.     

8.

Healthcare worker competencies for disaster training     

Edbert B Hsu  Tamara L Thomas  Eric B Bass  Dianne Whyne  Gabor D Kelen  Gary B Green 《BMC medical education》2006,6(1):19-9

Background  

Although training and education have long been accepted as integral to disaster preparedness, many currently taught practices are neither evidence-based nor standardized. The need for effective evidence-based disaster training of healthcare staff at all levels, including the development of standards and guidelines for training in the multi-disciplinary health response to major events, has been designated by the disaster response community as a high priority. We describe the application of systematic evidence-based consensus building methods to derive educational competencies and objectives in criteria-based preparedness and response relevant to all hospital healthcare workers.     

9.

Role of five platelet membrane glycoprotein polymorphisms in branch retinal vein occlusion.     

Ophira Salomon  Joseph Moisseiev  Tamara Vilganski  Rima Dardik  Shimon Kurtz  Eva Shpringer  David M Steinberg  Nurit Rosenberg 《Blood coagulation & fibrinolysis》2006,17(6):485-488

To determine whether polymorphisms of platelet surface glycoprotein associated with arterial thrombosis are risk factors for branch retinal vein occlusion. A case-control study in which 69 patients with branch retinal vein occlusion and 147 controls who attended the eye clinic for nonvascular complications participated. DNA was extracted from whole blood and analyzed for genotyping of platelet glycoprotein polymorphisms by polymerase chain reactions and specific restricted enzymes. No relationship was found between the four platelet glycoprotein polymorphisms i.e. GPIa C807T, VNTR and Kozak of glycoprotein Ibalpha, the HPA-1 of glycoprotein IIIa and the occurrence of branch retinal vein occlusion. The HPA-2 polymorphism was found in 18 out 60 (30%) patients with branch retinal vein occlusion in comparison with 27 out 142 (19%) of controls, with an estimated odds ratio of 1.8 (95% confidence interval, 0.91-3.65). The four platelet glycoprotein polymorphisms are not risk factors for branch retinal vein occlusion and therefore it seems unnecessary to screen those patients for it. A larger study is required, however, to determine whether HPA-2 is a novel risk factor for branch retinal vein occlusion.     

10.

Sexual and Drug Use Risk Behaviors of Long-Haul Truck Drivers and Their Commercial Sex Contacts in New Mexico     

Donna Hubbard McCree  Shannon Cosgrove  Dale Stratford  Sarah Valway  Nick Keller  Jaime Vega-Hernandez  Steven A. Jenison 《Public health reports (Washington, D.C. : 1974)》2010,125(1):52-60

     

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Mechanism of bronchodilator effect in chronic airflow limitation.

OBJECTIVE: To examine the mechanisms through which two bronchodilators (theophylline and salbutamol) influence dyspnea during daily activities. METHODS: Twenty-four patients with chronic airflow limitation participated in a multiple crossover, randomized, placebo-controlled trial. The effect of theophylline and salbutamol, alone or combined, on pulmonary function and dyspnea during daily activities was examined. Correlations of changes in forced expiratory volume in 1 second (FEV1) and maximum expiratory pressures (MIPs) (independent variables) and changes in dyspnea score during daily activities (dependent variable) were also examined. RESULTS: The two drugs proved to be beneficial the effects in general were additive rather than synergistic. The drugs improved the FEV1; theophylline significantly improved the MIPs. The correlation between the changes in FEV1 and those in dyspnea score, after adjustment for the changes in MIPs, was 0.55 (p less than 0.001). The correlation between the changes in MIPs and those in dyspnea score, after adjustment for the changes in FEV1, was 0.39 (p less than 0.001). CONCLUSIONS: Changes in airway calibre and in respiratory muscle strength play an independent and important role in dyspnea during daily activities in patients with chronic airflow limitation. Changes in airway calibre may be of greater importance.     

T cell subsets in human colostrum

Lymphocytes from 10 paired colostrum and peripheral blood specimens were examined to determine if the colostral T cell population differs from the peripheral blood T cell population in subset distribution. The percentages of lymphocytes staining with OKT3, OKT4, and OKT8 murine monoclonal antibody were determined. Lymphocytes from colostrum were 74.7 +/- 2.5% OKT3+, 50.6 +/- 2.3% OKT4+, 24.0 +/- 1.7% OKT8+, whereas peripheral blood lymphocytes were 78.7 +/- 1.9% OKT3+, 48.4 +/- 1.4% OKT4+, and 29.8 +/- 1.6% OKT8+. The percentage of colostrum lymphocytes positive for OKT3 was significantly although not strikingly lower than the OKT3 percentage for blood lymphocytes (p less than 0.05). This difference was due to the lower percentage of OKT8 positive lymphocytes in colostrum compared with blood (p less than 0.01). Although the T cell subset distribution of colostrum generally appears to be similar to that in the peripheral blood, there were small differences in OKT3 and OKT8 percentages that were statistically significant suggesting the possibility of some selectivity of the colostral T cell population.     

Healthcare worker competencies for disaster training

Background  

Although training and education have long been accepted as integral to disaster preparedness, many currently taught practices are neither evidence-based nor standardized. The need for effective evidence-based disaster training of healthcare staff at all levels, including the development of standards and guidelines for training in the multi-disciplinary health response to major events, has been designated by the disaster response community as a high priority. We describe the application of systematic evidence-based consensus building methods to derive educational competencies and objectives in criteria-based preparedness and response relevant to all hospital healthcare workers.     

Role of five platelet membrane glycoprotein polymorphisms in branch retinal vein occlusion.

To determine whether polymorphisms of platelet surface glycoprotein associated with arterial thrombosis are risk factors for branch retinal vein occlusion. A case-control study in which 69 patients with branch retinal vein occlusion and 147 controls who attended the eye clinic for nonvascular complications participated. DNA was extracted from whole blood and analyzed for genotyping of platelet glycoprotein polymorphisms by polymerase chain reactions and specific restricted enzymes. No relationship was found between the four platelet glycoprotein polymorphisms i.e. GPIa C807T, VNTR and Kozak of glycoprotein Ibalpha, the HPA-1 of glycoprotein IIIa and the occurrence of branch retinal vein occlusion. The HPA-2 polymorphism was found in 18 out 60 (30%) patients with branch retinal vein occlusion in comparison with 27 out 142 (19%) of controls, with an estimated odds ratio of 1.8 (95% confidence interval, 0.91-3.65). The four platelet glycoprotein polymorphisms are not risk factors for branch retinal vein occlusion and therefore it seems unnecessary to screen those patients for it. A larger study is required, however, to determine whether HPA-2 is a novel risk factor for branch retinal vein occlusion.