Combined immunostimulation in the prevention of tumor take in mice using endotoxins,their derivatives,and other immune adjuvants

Summary In this study a variety of immunostimulatory agents was tested alone or in combination with other agents to measure their ability to enhance nonspecific resistance to challenge with the TA3-Ha transplantable murine ascites tumor. Lipopolysaccharides (LPS) were effective alone in protecting mice from tumor. Their lipid-free, nontoxic, polysaccharide-rich hydrolytic products (PS) showed a much reduced, but still significant effect in anti-TA3-Ha resistance induction. Other agents that stimulated tumor resistance included nontoxic native hapten and trehalose-6,6-dimycolate (P3) of Ribi, synthetic glycolipids, cord factor, and killed BCG preparations. Simultaneous pretreatment with a combination of any of these agents and either LPS or PS resulted in a significantly higher level of tumor resistance. Administration of LPS, PS, or native hapten to mice that had been previously infected with viable BCG resulted in the strongest antitumor effect. These studies demonstrate that nonspecific resistance can be enhanced in an additive or synergistic manner by using combinations of agents, which presumably stimulate different cell populations of the host's immune system.     

Comparative trial of volunteer and professional treatments of dysphasia after stroke.

A study of the treatment of dysphasia after stroke compared the progress of two groups of disabled patients. One received conventional treatment from qualified speech therapists and the other from non-professional volunteers. Methods of assessing communication difficulties were also compared and the impact of aphasic illness on families examined. No important differences in the results of treatment were seen between the two groups. The volunteers, however, often had to assume some of the responsibilities of social workers, and transport to hospital created practical and economic problems. It is concluded that the two forms of treatment provide essentially the same benefit, although doubt must still remain because relatively few patients were studied.     

Correlation of absorbance changes and thylakoid fusion with the induction of oxygen evolution in bean leaves greened by brief flashes

Dark-grown bean leaves (Phaseolus vulgaris) which had been greened for several days in a repetitive series of brief xenon flashes were studied during the initial induction period when O(2) evolution first appears. The induction of O(2) evolution requires actinic irradiation (e.g. 2 mw/cm(2) of red light) and goes to completion in about 8 minutes with a half-time just under 3 minutes. Absorbance measurements on the intact leaves showed that a change of a carotenoid pigment, monitored at 505 nm, was closely correlated with the rate of O(2) evolution during the induction period. Inhibitor studies, however, showed that the absorbance change persisted in the presence of a number of inhibitors which blocked O(2) evolution. Electron microscopy revealed that the primary thylakoids which were unfused in the flashed leaves before induction became fused in pairs or groups of three during the 8-minute induction period. It is postulated that the 505-nm absorbance change of the carotenoid pigment is correlated more directly with the fusion process than with O(2) evolution. Heat treatment (45 C for 5 min) or infiltration with 0.8 m tris, which prevented the fusion process, also prevented the absorbance change.If the leaves were preilluminated for 8 minutes with very weak red light (20 muw/cm(2)) which induced no O(2) evolution, absorbance change, or thylakoid fusion, there was an immediate burst of O(2) evolution at the onset of actinic irradiation and the induction period, as noted by O(2) evolution or by the 505-nm absorbance change, was reduced to 2 minutes (half-time of 40 seconds). It is concluded that the electron transport system in the flashed leaves is blocked at the Mn site between water and photosystem II and that the photoactivation of Mn into the thylakoid membranes occurs during the low light, photoactivation process. After the electron transport chain is thus repaired, ion-pumping mechanisms driven by actinic light may lead to steady-state photosynthesis as well as to thylakoid fusion.     

Arbitration Agreements and Your Malpractice Coverage

With new legislation and favorable case law developments, many providers of health care services are turning to binding arbitration agreements as a partial solution to the medical malpractice crisis. Existing data indicate tremendous advantages can be gained from the use of such agreements, if they are carefully drawn to comply with new law, tailored to the particular situation in which they will be used and coupled with appropriate procedures to secure the intended benefits.Arbitration is not a substitute for insurance, but if a provider has taken the calculated risk of forgoing insurance he should not be without a carefully drawn binding arbitration agreement.     

Energy transfer in the photochemical apparatus of flashed bean leaves

Fluorescence and energy transfer properties of bean leaves greened by brief, repetitive xenon flashes were studied at −196 °C. The bleaching of P-700 has no influence on the yield of fluorescence at any wavelength of emission. The light-induced fluorescence yield changes which are observed in both the 690 and 730 nm emission bands in the low temperature fluorescence spectra are due to changes in the state of the Photosystem II reaction centers. The fluorescence yield changes in the 730 nm band are attributed to energy transfer from Photosystem II to Photosystem I. Such energy transfer was also confirmed by measurements of the rate of photooxidation of P-700 at −196 °C in leaves in which the Photosystem II reaction centers were either all open or all closed. It is concluded that energy transfer from Photosystem II to Photosystem I occurs in the flashed bean leaves which lack the light-harvesting chlorophyll a/b protein.     

Specific cleavage of the native type III collagen molecule with trypsin. Similarity of the cleavage products to collagenase-produced fragments and primary structure at the cleavage site.

Solutions of native Type III collagen (chain composition, [α1(III)]₃) exhibit a rapid and dramatic decrease in relative viscosity when incubated with trypsin. Cleavage products of the reaction were precipitated with ammonium sulfate and isolated in denatured form by molecular sieve chromatography. They were found to be comprised of: α1(III)-T1 (molecular weight, 71,000) derived from the NH₂-terminal portion of the Type III molecule; and α1(III)-T2 (molecular weight, 24,000) from the COOH-terminal portion of the molecule. Determination of the amino acid sequence at the NH₂-terminal portion of α1(III)-T2 as well as at the COOH-terminus of α(III)-T1 demonstrated that the products arose from specific cleavage of the type III molecule at an arginine-glycine bond corresponding to residues 780–781 in the repetitive triplet sequence of the α1(III) chain. The results suggest that the trypsin-susceptible bond in the native Type III collagen molecule resides in a region characterized by a relative lack of the normal collagen helicity.     

Purification and some properties of the phosphoprotein from rat incisors.

The phosphoprotein of rat incisors has been purified by successive gel and ion-exchange chromatography. The product gave a single band on polyacrylamide gel electrophoresis and contained approximately 34% phosphoserine and 32% aspartic acid. Alkaline elimination experiments showed all the phosphate to be present as phosphoserine. Ultraviolet spectra in the presence or absence of ATP showed that the phosphoprotein did not contain an nucleotide moiety as suggested by Veis, A., Spector, A. R. and Zamoscianyk, H. ((1972) Biochim. Biophys. Acta 257, 404-413) for bovine dentin phosphoprotein.