Upregulation of the surface expression of two integrins and induction of chemotactic activity in a human leukemic cell line by Oncoimmunin-M

Previously, it was shown that Oncoimmunin-M (OI-M), a recently identified tumor cell-derived 36 kDa protein, is able both to inhibit the proliferation of the human promyelocytic leukemic cell line HL-60 while maintaining viability in culture and to induce a bimodal distribution of CD11b, the alpha chain of the integrin MAC-1, on the cell surface (Packard, B.Z. and Komoriya, A. (1993) J. Biol. Chem. 268, 6356-6363). Now, data which reveal that exposure of HL-60 cells to this factor also brings about an increase in the mean level of surface expression of CD11c, the alpha chain of another leukocyte integrin (p150,95), but leaves CD11a, the alpha chain of the third leukointegrin (LFA-1), virtually unchanged (< 10%) are presented. Comparison of motility studies of OI-M-treated HL-60 bulk populations with control bulk populations demonstrates coinduction of CD11b and CD11c surface upregulation with chemotactic responsiveness to a gradient of the chemoattractant human C5a. Separation of motile from nonmotile cell subpopulations after exposure to C5a further reveals that individual cells which respond to this chemoattractant express increased levels of both CD11b and CD11c relative to unresponsive cells. These data correlate the upregulation of leukointegrins MAC-1 and p150,95 by a tumor cell-derived protein on a preterminally differentiated myeloid cell with chemotactic responsiveness to human C5a.     

Distribution of prostaglandin IP and EP receptor subtypes and isoforms in platelets and human umbilical artery smooth muscle cells

Prostaglandins act through specific receptors to stimulate cyclic AMP formation which inhibits platelet activation and relaxes vascular smooth muscle. We have used RT-PCR combined with Southern blot analysis to determine the subtypes of prostaglandin receptor on platelets. Platelets expressed the EP4 rather than the EP2 prostaglandin EP receptor subtype, whereas vascular smooth muscle cells predominantly expressed the EP2 receptor. The IP receptor, which binds prostacyclin and couples to stimulation of adenylyl cyclase, and three isoforms of the inhibitory EP3 receptor were equally expressed in platelets, HEL cells and umbilical artery smooth muscle cells. The EP3-II isoform showed variation in level of expression among the three cell types. As a positive control for the presence of platelet RNA, PCR was performed using primers specific for the alpha chain of the platelet membrane glycoprotein Ib. As a negative control for the absence of T and B cell contamination in the platelet RNA, PCR was performed using primers specific for the cell specific cluster determinants CD2 (a T-cell marker) and CD20 (a B-cell marker). The finding that platelets express both stimulatory and inhibitory prostaglandin receptors provides confirmation of a homeostatic model of regulation of platelet adenylyl cyclase previously proposed.     

Illness and injury in family day care: a seasonal survey

Many mothers with children under age 6 are employed and it is not usually feasible for a parent to stay home with a child who is mildly ill. Such ill children likely remain in child day care programs. The extent to which this occurs and the management of these children in family day care was studied. Over the course of a year, 1 to 3 visits were made to 714 family day care homes in order to survey providers. With enrollments ranging between 0 and 18 children per day care home at the time of each visit, information on 3,630 "child enrollment days" was collected. The median age of children in care was 2 years. An average of 16% of all children were ill on any one day (with seasonal variation); 1% were injured. Of ill children, 82% attended day care that day, 49% had contacted a physician about that illness, and 28% were administered a medication at the day care setting. Twenty-one percent of children receiving medication in day care had no contact with a physician for that illness. These data show that mild childhood illnesses are routinely managed by child day care providers. Physicians who traditionally limit their illness-management education to parents need to recognize the health education and consultation needs of day care providers.     

取代苯甲酸葡萄糖酯的合成及生物活性

以两种方法合成了10个取代苯甲酸葡萄糖酯类化合物，一是相转移催化法，二是在三忆胺的存在下，取代苯甲酸与溴代葡萄糖反应，该种合成糖酯的方法未见文献报道，取代苯甲酸葡萄糖酯的结构由IR、MS、^1H NMR和元素分析确认。对化合物的抗病毒活性测试结果发现，其中有两个化合物具有一定的抑制TMV的活性。     

Influence of CF<Subscript>3</Subscript>I and CBrF<Subscript>3</Subscript> on Methanol–Air and Methane–Air Premixed Flames

The suppression of CH₄ and CH₃OH premixed flames with CBrF₃ and CF₃I is examined, using computational techniques. By combining sensitivity analysis, reaction pathway analysis (based on carbon, hydrogen, bromine and iodine atom fluxes) and heat release estimation, we develop an explanation for the difference of suppression efficiencies which is qualitatively consistent with experimental cup burner data. The key reaction steps and channels responsible for the (apparent) higher inhibition efficiency of CF₃I compared to CBrF₃ in CH₃OH premixed flames are disclosed, by combining reaction pathway and heat release contribution analysis. The reaction of bromine atom dominates the decomposition channel for CH₃OH but plays a relatively minor role in the activation of CH₄, while I atom plays a minor role in CH₃OH or CH₄ activation. Accordingly, the rate of production of flame propagating radicals CH₂O and OH is higher in a CH₃OH–air–CBrF₃ system than in a CH₃OH–air–CF₃I system. The overall conclusion is that CBrF₃ contributes significantly to flame propagation for CH₃OH fuel reactions and consequently more CBrF₃ is required to extinguish a CH₃OH flame than CF₃I. Finally the explanation is validated by applying the reaction “switching-off” test.     

Coal oxidation at low temperatures: oxygen consumption, oxidation products, reaction mechanism and kinetic modelling

Coal oxidation at low temperatures (i.e. <100 °C) is the major heat source responsible for the self-heating and spontaneous combustion of coal and is an important source of greenhouse gas emissions. This review focuses on the chemical reactions occurring during low-temperature oxidation of coal. Current understanding indicates that this process involves consumption of O₂, formation of solid oxygenated complexes, thermal decomposition of solid oxygenated complexes and generation of gaseous oxidation products. Parameters, such as mass change, heat release, oxygen consumption, and formation of oxidation products in the gas or solid phase, have been used to qualitatively and quantitatively describe the oxidation process. Reaction mechanisms have been proposed to explain the characteristics of consumption of O₂, and formation of oxidation products in the gas and solid phases. Various kinetic models have also been developed to describe the rate of oxygen consumption and the rates of formation of gaseous oxidation products in terms of the rate parameters of the relevant reactions, oxidation time, temperature, and initial concentration of oxygen in the oxidising medium. Further research emphasis should be placed on the formation of the complete reaction pathways proceeding in the oxidation process and on the development of kinetic models applicable for predicting the self-heating and gas emission in a coal seam or stockpile.     

The use of benzyl alcohol and amyl-m-cresol (Strepsils) in the oral cavity. (Review of the literature and first clinical experiences)

The authors summarised the literature data of benzylalcohol and amyl-m-cresol. In the clinical practice they used Strepsils in the treatment of 22 patients suffered from oral inflammatic diseases and in the 20 prophylactic cases of oral surgical interventions. The preliminary clinical report shows that, the Strepsils seems to be very effective in the treatment of oral inflammations and in the prophylaxis too.     

Kinetic modeling of low-temperature oxidation of coal

A kinetic model has been developed for determining the rate of oxygen consumption and production of carbon oxides during the oxidation of coal at low temperatures (i.e. <100°C), based on current understanding of the mechanism of coal oxidation. The chemical reactions considered in the model include two parallel sequences consuming oxygen and two thermal decomposition pathways producing carbon oxides. The resulting rate expressions reflect the contributions of various reactions consuming oxygen and producing carbon oxides and predict the effects of temperature, oxidation time and [O₂] in the gas phase. The general form of the rate expressions confirms that chemisorption is relatively fast, only playing an important rôle at the early stage of coal oxidation. With the formation of stable and unreactive oxygenated complexes in a coal’s structure, the oxidation of coal is dominated by thermal decomposition of oxygenated complexes.     

The case of the salad shooters: intravenous injection of wild lettuce extract

Three young adult drug users obtained wild lettuce and valerian root, prepared a crude aqueous extract of the wild lettuce, and injected the extract i.v. One also injected an alcohol extract of the valerian root. All 3 rapidly became ill with fevers, chills, abdominal pain, flank and back pain, neck stiffness, headache, leucocytosis and mild liver function abnormalities, but recovered over the next 3 d. Various literature and internet sources claim that wild lettuce has opiate properties not demonstrated in this case.