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There are a number of diseases associated with herpes simplex virus infections, and although there are available treatments, there is still a need for new therapies. Some peptides have proved to have an antiviral effect, but the high flexibility and complex mode of action makes it difficult to obtain reliable quantitative structure–activity relationships. In this article, we report on the use of theoretically derived amino acid descriptors for the modelling of peptide activity as a mean to find lead compounds based on biologically active peptides.

By means of the macrophage electrophoretic mobility (MEM) test the supposed immunosuppressive activity of the pregnancy-associated a2-glycoprotein (pregnancy zone protein) could be demonstrated significantly. Pregnancy sera and sera of nonpregnant women with hormonal contraception containing this pregnancy protein showed an immunosuppressive activity, too. On the contrary, serum of male donors with the blood group AB and human serum albumin had no inhibitory effects. The results suggest that the pregnancy-associated a2-glycoprotein rather influences the afferent limb of the immune response and does not interfere with the activity of the mediator (migration inhibiting factor).

In an unconventional assay system (MEM Test) Caspary & Field claimed in 1971 to have detected lymphocyte sensitization to a common tumour antigen in all patients with cancer. There was no evidence of histogenetic specificity to the reaction and their conclusions are in direct contradiction to those of all workers who have studied the cytotoxic activity of lymphocytes on tumour cells. To improve the specificity of the test system, another type of tumour antigen was used in MEM Test incubation. Tumour-associated antigens were prepared according to the hypertonic salt extraction method introduced by Reisfeld, Leonard, Meltzer et al. As shown by the results, information could be gained concerning the existence of a malignant tumour and its location.

Room-temperature tunable-laser action has been observed in Cr-doped SrAlF_5. The measured tuning range is 852–947 nm in a quasi-cw laser mode. The effect of nonequivalent Cr sites in SrAlF_5 is studied from the absorption and the excitation spectra. A broad absorption band peaked near 750 nm does not contribute to the Cr emission and appears to be associated with a nonradiative site.

Variably valent iron impurities have been suggested as the source of photorefractive charge carriers in BaTiO_3. High-purity BaTiO_3 crystals were grown with transition-metal impurity levels below the 10^16 cm^−3 baseline estimated for photorefractivity. Iron-doped crystals were grown with concentrations of 5, 50, 250, 500, 750, and 1000 parts in 10^6 of iron. Changes in iron valence monitored by optical absorption in the P_O2 range 1–10^−4 atm were found to be consistent with a defect-chemical model indicating Fe^3+ and Fe^4+ to be the stable valence states in this range. Photorefractive characterization of high-purity BaTiO_3 suggests that variably valent iron ions are not the dominant photorefractive species in these crystals, whereas the role of iron centers in doped crystals is complicated by large absorption losses.

Room-temperature polarized reflectivity measurements are reported for single-crystal La_2CuO_4 for the (E ⊥ ĉ) and (E || ĉ) polarizations, where ĉ denotes the tetragonal axis. A Kramers–Krönig analysis is performed to obtain the frequency-dependent dielectric functions. Frequencies for the seven zone-center IR-active phonons are obtained and the longitudinal-optic–transverse-optic splittings are used to evaluate the dynamic charge on the oxygen atoms. The reflectivity spectrum for the (E ⊥ ĉ) polarization is decidedly metallic and is fitted accordingly with an overdamped Drude model and a plasma frequency of 95 meV. In the high-frequency region of the spectrum, selection rules are observed for allowed and forbidden electronic transitions. The importance of this study to the interpretation of optical measurements on high-Tc, polycrystalline pellets of La_2CuO_4 and related materials is also discussed.

Rabbits were sensitized intracutaneously with Candida albicans total antigen by a series of booster injections. The electrophoretic migration time of lymph node lymphocytes was related to the time after injection. Two lymphocyte sub-populations could be distinguished. The proportion of each, changed during the course of the immune response. Characteristic changes also took place after in vitro incubation with Candidin. The results have been compared with agglutination titers and are discussed in relation to bursa and thymus-derived cells. The electrophoretic method may be valuable for the diagnosis of candidiasis.