Common cold experimentation

Bende, M., Barrow, ]., Heptonstall, J., Higgins, P. G., Al-Nakib, W., Tyrrell, D.. 4.. ind Aker lund, A. (1989). Changes in human nasal mucosa during experimental coronaviruH common colds, Acta Otolaryngol. (Utockh) 107, 262-269. 

Suppose a researcher develops a drug that is intended to cure the common cold. He gives the drug to a volunteer who has just contracted a viral cold. One week later the volunteer no longer has a cold, and the researcher announces to the press that his drug is a success. Comment. Suggest a better experimental design. 

Turner et al. (2005) evaluated the efficacy of Echinacea angustifolia in experimental rhinovirus infections. The results of this study indicate that extracts of E. angustifolia root, either alone or in combination, did not have clinically significant effects on the infection or on the clinical illness that results from it. Be that as it may, many believe in echinacea and used it routinely to avert the common cold. 

The safety and efficacy of NSAIDs for the relief of symptoms of the common cold have been insufficiently studied. Naproxen did not alter virus shedding or the serum-neutralizing antibody response in healthy young adults with experimental rhinovirus colds but had some beneficial effect on symptoms (SEDA-17,113). 

Phase III trials R01 Ronald Turner/ University of Virginia Evaluate the effect of different echinacea constituents on rhinovirus infection and rhinovirus-induced illness (experimental common cold model)... 

Hence, the treatment for the common cold remains largely palliative rather than curative. Administration of anti-inflammatory agents like aspirin, decongestants like ephedrine, and anti-histamines will relieve many of the symptoms without necessarily reducing the period of infection. The codeinelike drug dextromorphan is also used and this acts upon the A-methyl-D-aspartate (NMDA) receptors in the brain to increase the threshold for cough induction. One new experimental treatment involves the intranasal administration of ICAM-1 fragments to saturate the receptors. 

Hypothyroid myopathy occurs in about 30% of patients with hypothyroidism irrespective of its cause. Muscle pain, cramps, and stiffness may be seen, and are often exacerbated by cold weather. Pseudomyotonic features of delayed muscle contraction and relaxation are common. Myoedema (the mounding phenomenon) is due to the painless, electrically silent contracture produced on direct percussion. Muscle biopsy often shows a predominance of type 1 (slow-twitch) fibers, again analogous to that seen in experimental hypothyroidism (Figure 22). Muscle hypertrophy with weakness and slowness of movement occurs in the Debre-Semelaigne syndrome seen in severely hypothyroid children, and Hoffman s syndrome is a similar condition seen in adults with hypothyroidism, but is also accompanied by painful spasms. 

Seawater is the most abundant aqueous solution on Earth, and, as a consequence, has been the subject of countless studies (Millero 2001). The occurrence of marine evaporites has spurred much of the work on seawater solidification, which can occur by either evaporation or freezing. Early experimental work on the evaporation of seawater was done by Usiglio (1849). Whereas most evaporites on Earth probably involved mainly or only evaporation (particularly under hot, arid climatic conditions, 25-50 °C), cold-climate evaporation and freezing without evaporation are also common means by which... 

Although the classical approach is analytically fairly robust and yields reliable results for the elemental abundance of noble gases in waters, there are some experimental difficulties that are delicate to deal with. The most critical point is the element specific gas release from the cryostatic cold trap. In particular the elemental selectivity of cryostatic cold traps is too coarse to completely isolate Ar from Kr. As common ion-sources are tuned to maximum sensitivity their response to different gas amounts is not only highly non-linear, but also depends on the relative presence of all components in the rest gas. Hence the Ar residual in the Kr determination may cause analytical problems, because of the overwhelming atmospheric Ar abundance. 

Almost all solids are more soluble in a hot than in a cold solvent, and solution crystallization takes advantage of this fact. Thus, if you first dissolve a solid in an amount of hot solvent insufficient to dissolve it when cold, crystals should form when the hot solution is allowed to cool. The extent to which the solid precipitates depends on the difference in its solubility in the particular solvent at temperatures between the extremes used. The upper extreme is determined by the boiling point of the solvent, whereas the lower limit is usually dictated by experimental convenience. For example, an ice-water bath is often used to cool the solution to 0 °C, whereas ice-salt and dry ice-acetone baths are commonly used to cool solutions to -20 °C and -78 °C, respectively (Sec. 2.10). The solid should be recovered with greater efficiency at these temperatures, provided the solvent itself does not freeze. 

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