Early Concerns

With regard to left ventricular function, cardiac stem cell therapy is well tolerated overall. No proar-rhythmic effects have been observed to date with ABMMNC therapy, although other deleterious effects are possible. Early concerns about abnormal transdifferentiation and tumorigenesis have subsided, but the potential for accelerated atherogen-esis remains, given the limited clinical experience... 

One of the early concerns about the application of DNA microarray to toxicology has been how to properly compare experiments that use a wide variety of commercial and proprietary platforms, protocols, and analyses methods. The Health and Environmental Sciences Institute (HESI) of the International Life Sciences Institute (ILSI) has... 

He states this early concern in a talk to the Deutsche Chemische Gesellschaft W. Noddack, Zeitschrifi fur angewandte Chemie 38 (1925) 876. 

An early concern in studies of the activation of ACC by citrate was that the concentration of citrate required for activation was higher than that normally observed in tissues. Thus, it was of interest to find that the Km for the binding of citrate to phosphorylated ACC of 2.4 mM was reduced to 0.2 mM by dephosphorylation (Carlson and Kim, 1974). Further, the dephosphorylated form of ACC is more susceptible to inhibition by palmi-toyl-CoA. Also, phosphorylation and inactivation of ACC is accompanied by conversion of active polymers to inactive protomers (Shiao et al., 1981). Mabrouk et al. (1990) found that inactive protomers isolated from the livers of rats injected with glucagon have a higher phosphate content than protomers isolated from the livers of control animals. 

Early concerns for risks from chemicals started from very obvious toxic effects on humans. Carcinogenic effects were recognised quite early, and later less immediate effects came in, such as hereditary disease and neurological effects. 

An early concern with the HPLC technique was the use of high pressures to achieve high flow rates of the mobile phase through a column packed with microparticulate silica. Recent improvements in column design and operating procedures, however, allow the purification of proteins at modest pressures (e.g., 500 psi) and flow rates (30-60 ml/h). Since it has been reported that C 3-alkyl chains are compatible with catalytic activity of adsorbed and eluted proteins, but larger alkyl substituents may cause denaturation (26), the use of reversed-phase columns of medium polarity, e.g., —C Hy-phenyl, when combined with a judicious choice of organic modifier and salt concentrations (e.g., isopropanol and phosphate) at pH... 

An early concern was the possibihty that H2 receptor antagonists could predispose to gastric carcinogenesis, but this seems to have been allayed, as was the fear once expressed that ulcers might be more liable to perforate after cimetidine had been given and withdrawn. 

Aerial oxidation of trichloromethane (chloroform), on storage, results in the contamination of the material with phosgene. Early concerns, at the time when chloroform was commonly used as an anaesthetic, have been recorded [134]. 

There was much early concern about the destination of a third of the young people leaving NDYP who were recorded as entering unknown destinations . A... 

Early concern about resistance to the pyrethroids resulted in the initiation of monitoring programs. As early as 1975, studies by university researchers were initiated to determine H. virescens susceptibility to the pyrethroids (15-17. The results of these studies generally indicated localized shifts in tolerances in field collected strains of Ii. virescens. However, few of these studies related "resistance" levels detected in laboratory tests of field strains to insect control in the field. Martinez-Carrillo and Reynolds (16 pointed out that even though they detected high levels of resistance, no field control failures had yet been reported. They did warn, however, that failures were possible if application trends continued. Subsequently, FMC and ICI, two of the first manufacturers of pyrethroids, established monitoring programs in the early 1980 s Q ). ... 

After early concern over the accumulation of DDT in biota, analysis of DDT and its metabolites was carried out by nitration and col-orometric measurement after treatment with alkali. This was superseded by GC some 15 years later, and this development facilitated more rapid analysis, greater precision, and simultaneous unambiguous analysis of DDT metabolites such as DDE and DDD. 

An early concern on the hypotensive properties of solutions of SNP, which manifest readily a few seconds after injection, led to the proposal that reaction (16) is rapidly established once SNP is reduced by the thiolates in the biological medium. Given the inertness of [Fe(CN)5(NO)] toward NO-release (10), the activation of sGC was assigned to the lability of [Fe(CN)4(NO)] ("137). As there was no evidence in favor of the latter proposal, we afforded a kinetic and mechanistic study on the thermal decom-... 

The radiation densities, both y and neutron, are higher in a plutonium producing pile than can be maintained outside the pile for extended periods. The effect of these radiations on the structure of materials was one of our early concerns from the theoretical point of view. The experimental work was carried out in the Chemistry Division. Dr. M. Burton reported at the Atlantic City meeting of the American Chemical Society about his, his collaborators and Dr. J. Franck s work on the subject. On the theoretical side, M. Goldberger, R. S. Mulliken, and F. Seitz shared my interest in the subject which still has some aspects about which we cannot talk freely. 

Over the years, these considerations have concerned many chemists. Indeed Merrifield himself must have been early concerned about the need for mild reaction conditions. His original technique (2) employed the very stable benzyl-nitrobenzyl a-amino-protecting group-resin linkage combination, soon to be replaced in his bradykinin paper (3) by the more labile f-butyl/... 

Ideally, the design of the assembled product will include consideration of the bond area, the performance requirement of the adhesive, the method of application, and the manner in which the adhesive will be cured. Ignoring any of these factors early in the design of the assembly line can lead to difficult problems later on, when the product is being manufactured. Early concern for these elements should result in optimum use of the selected adhesive. 

The history of environmental engineering is extensive, although the discipline was not called that until recently. Early concerns about water quality appear in human history dating back to 2000 BCE. The ancient Romans built an extensive aqueduct system to provide fresh water to their cities. Some evidence indicates that they had wastewater treatment collection systems as well. 

An early concern of CO2 in dry cleaning was that CO2 will cause clothes to shrink. However, preliminary tests indicate that shrinkage is within industry standards (81). Another concern is that CO2 might swell fabrics, particularly acrylics. Still another concern is how CO2 will affect some of the dyes used to color fabrics (81). 

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