Artifactual stimulation of vitellogenesis in Aedes aegypti by 20-hydroxyecdysone

Single or repeated, non-physiological, high doses (0.5–5.0 μg/female) of 20-hydroxyecdysone or ecdysone injected into sugar-fed female Aedes aegypti stimulated follicular growth and deposition of yolk, but suppressed accumulation of protein yolk to approximately one-third, and lipid yolk to one-half that in an equal number of follicles with equivalent yolk length taken from blood-fed controls. Physiological doses (500 pg/female) of ecdysone or 20-hydroxyecdysone or the implantation of ecdysone-secreting ovaries (verified by bioassay), into sugar-fed females failed to induce any yolk deposition. In these experiments, yolk precursors were not the limiting factor, because in decapitated females, digesting a blood meal, the injection of a physiological dose of 20-hydroxyecdysone or the implantation of ecdysone-secreting ovaries still did not stimulate vitellogenesis. Finally, continuous infusion of 500 pg or even 50 ng 20-hydroxyecdysone/hr for 22 hr was as ineffective as single or multiple injections of equivalent doses of hormone. Consequently, rapid excretion or catabolism of 20-hydroxyecdysone by the sugar-fed female does not explain the need for high doses to induce vitellogenesis, or the failure of oöcytes to mature with normal protein and lipid content. Apparently, ovarian ecdysone is not the factor by which normal vitellogenesis is initiated and maintained in this mosquito.     

Reversions of two proline-requiring auxotrophs of Haemophilus influenzae by n-methyl-n'-nitro-n-nitrosoguanidine and hydrazine.

New mutation detection systems are described for Haemophilus influenzae. They involve two independently isolated proline auxotrophs which appear to be mutants at different sites in a proline locus (proB) that is very closely linked to a locus (thd) for thymidine requirement. One of the mutants, proB1, appears to revert to prototrophy only by mutations at the locus. The other, proB2, reverts both by mutation at the locus and by unlinked suppressors. The latter account for about 90% of the reversions induced by MNNG and by HZ. The close linkage of proB to thd was used to distinguish between true revertants and suppressors by a transformation test. A comparison was made between the mutation induction kinetics of the different classes of revertants and mutations to novobiocin resistance with MNNG and HZ. The very different induction kinetics for these two mutagens previously reported for the novobiocin resistance system were also found for the proline systems. There were some differences between the detection systems, however, in the frequency of induced mutation relative to the spontaneous frequency and, in one case, in the form of the induction curve. It is concluded that the major features of the induction curves reflect the amount of damage done to DNA and so are general for all systems, but that there are some features which are locus-or site-specific.     

Changes in the fine structure of venous endothelium in the rabbit following adrenaline infusion

Summary The fine structure of the endothelium lining the femoral and mesenteric veins in the rabbit was examined following the infusion of concentrations of adrenaline varying from 0.5 to 5.0 g/kg. Control animals were infused with saline.Vesiculation of the endothelial cells was observed following each infusion of adrenaline, the effect being most marked with the highest dose used. It is suggested that this vesiculation may be associated with the release of antihaemophilic globulin and/or plasminogen activator from the endothelial cells.The authors wish to express their gratitude to Mrs. M. Woodford, Miss. G. Moore and Mr. R. Ellis for their skilful technical assistance     

玉米黄粉的综合利用研究

从农副产品深加工的角度出发,研究了玉米淀粉厂的下脚料──玉米黄粉的综合开发利用的途径,给出了利用玉米黄粉制取天然黄色素的工艺方法和性能指标,获得玉米蛋白粉和玉米醇溶蛋白二个产品,使原来因有特殊臭味只能做饲料使用的玉米黄粉得以升级增值,具有较好的经济效益,溶剂可以回收,全过程无三废排放。     

The Optimum Dosage Regimen of Intravenous Infusion for Drugs Obeying Parallel First-order and Michaelis-Menten Elimination Kinetics

IntravenousInfusionIsoneofthewarwidelyu。dIntheclinlcaltherapy．Within时slon,drugcandirectlyenterthecirculationofthebody,andplasmaconcentrationcanmain－tainastableStateafteraPer止dOfcontinuousInfusion．ItIsposslbktoletpbteauconcentra－tlonequaltothemosteffectivetherapeuticconcentrationbyadjustingtherateofInfusion．ButtheweaknessofintravenousInfusionIsthattheplasmaconcentralonkvelIstoolowtomeettheneedofclinicaltherapyduringtheInitialadmlnlstratlonperiod．Asimpleandpractlcafmethdtooverco…     

重症银环蛇咬伤11例治疗报告

11例重症银环蛇咬伤病人,入院后经伤口局部处理,气管插管,呼吸机,大量补液,利尿激素等综合治疗,10例治愈,1例死亡.我们从中体会到重症银环蛇咬伤病人,只要以上指施及时得力,虽不用抗毒血清[只1例用抗毒血清]多数病人仍可得救。     

Genetic transformation of a Corynebacterial symbiont from the Chagas disease vector Triatoma infestans

Insect-borne diseases have experienced a troubling resurgence in recent years. Emergence of resistance to pesticides greatly hampers control efforts. Paratransgenesis, or the genetic transformation of bacterial symbionts of disease vectors, is an alternative to traditional approaches. Previously, we developed paratransgenic lines of Rhodnius prolixus, a vector of Chagas disease in Central America. Here, we report identification of a Corynebacterial species as a symbiont of Triatoma infestans, a leading vector of Chagas disease in South America. We have modified this bacterium to produce an immunologically active single chain antibody fragment, termed rDB3. This study establishes the basis for generating paratransgenic T. infestans as a strategy for control of Chagas disease.     

First phase release coefficient of insulin in subjects with normal glucose tolerance on glucose infusion analyzed by computer simulation

We report here a mathematical model using computer simulation to solve the phase fractionation coefficient (f) of instantaneous insulin release on glucose infusion. By extensive model testing with the cited parameters obtained from the literature, the values of the factor f were shown to lie in range of 0.93+/-0.02 (mean+/-2S.D., n=15), indicating that the high pulsatile bolus of glucose by i.v. infusion may trigger acute insulin release (AIR) corresponding to a fraction of more than 90% of the stored insulin release in the first phase from the secretory granules of pancreatic beta cells. In addition, the value of the factor f was shown to be independent of both the glucose infusion method and the non-insulin-dependent uptake of glucose.     

Chronomodulated chemotherapy: clinical value and possibilities for dissemination in the United States

Modern medicine has been relatively slow to apply chronotherapeutic principles to standard oncologic practice. Despite the impressive body of evidence supporting the use of chronochemotherapy, with only a rare exception most oncology clinics in the United States lack the expertise and capability to implement it. At the same time, American medicine has increasingly come to recognize the importance of toxicity mitigation, cytoprotection, and quality of life for patients undergoing cancer treatment. However, toxicity mitigation strategies such as chronomodulated infusional chemotherapy and novel cytoprotective agents are not widely embraced by U.S. physicians. This article explores some reasons why this situation exists, including the influence of non-medical biases that may affect management decisions on the application of chemotherapy. The author conducted a survey of U.S. companies representing the three private insurance payers available (HMO, PPO, Indemnity) as well as representatives of Medicare and Medicaid. Responses to the survey confirmed that U.S. insurers do not at present officially reimburse for chronotherapy; however, changes will come about through educational efforts aimed at increasing awareness among insurers as to the clinical benefits and cost-effectiveness of this mode of treatment. At this juncture, the outlook for cancer chronotherapy as a first-line approach to the treatment of metastatic cancer in the United States remains uncertain. Under the current method of insurance reimbursement, the advancement of chronotherapy in the United States is threatened despite evidence that such treatment is both therapeutically sound and cost-effective.