Regulation of the immune system by synthetic polynucleotides. VI. Amplification of the immune response in young and aging mice

Model systems for study of the action of adjuvants in immunodeficient states were developed in 10- to 14-day-old BALB/aj mice and aging BALB/aj mice (12 to 16 months). With sheep red blood cells as antigen polyadenylicpolyuridylic acid complexes (poly A:U) were found to be stimulatory in both the neonatal and aging mice. The effect of poly A:U was similar to that seen when 5 X 10(6) thymocytes from immunologically mature mice were given with antigen. Cell-free supernatant fluids induced by incubation of poly A:U with thymocytes likewise were capable of restoring the number of antibody-forming cells to normalcy in aging mice.     

Leucocyte-migration inhibition induced by uveoretinal antigen in patients with diabetic retinopathy

Leucocyte-migration inhibition was to determine the state of hypersensitivity in 65 diabetic patients with different stages of retinopathy and 21 nondiabetic controls. About one third of the patients with simple or proliferative retinopathy exhibited significant leucocyte-migration inhibition of 0.2 mg/ml. protein concentration of uvreoretinal antigen. In contrast, only one of 15 patients with minimal retinopathy and none of the controls showed significant leucocyte-migration inhibition. Corneal and lenticular antigens did not evoke a cellular immune response in any of the tested individuals. These findings suggest that cell-mediated hypersensitivity to uveoretinal antigen may develop in diabetic patients with prolonged, progressive, simple or proliferative retinopathy.     

Women's attitudes to mastectomy for breast cancer

One hundred patients who had been subjected to mastectomy for carcinoma were interviewed retrospectively to gauge their attitudes to any physical and/or emotional disabilities relating to their operation or disease. It was found that 40% of the patients had delayed for longer than a month after the onset of symptoms before seeking medical advice, but the reasons for this were not readily forthcoming. However, fear of mastectomy was not a common cause. Anxiety and embarassment due to an absent breast occurred in about one-third of patients, and did not diminish with time. Knowledge and the use of mammary prostheses was far from universal, and disturbingly only two-thirds were counselled in these matters by their medical advisers. Physical complications were common, particularly lymphoedema of the arm, and as expected this was closely related to the type and extent of treatment undertaken.     

Carotene Degradation and Isomerization during Thermal Processing: A Review on the Kinetic Aspects

Kinetic models are important tools for process design and optimization to balance desired and undesired reactions taking place in complex food systems during food processing and preservation. This review covers the state of the art on kinetic models available to describe heat-induced conversion of carotenoids, in particular lycopene and β-carotene. First, relevant properties of these carotenoids are discussed. Second, some general aspects of kinetic modeling are introduced, including both empirical single-response modeling and mechanism-based multi-response modeling. The merits of multi-response modeling to simultaneously describe carotene degradation and isomerization are demonstrated. The future challenge in this research field lies in the extension of the current multi-response models to better approach the real reaction pathway and in the integration of kinetic models with mass transfer models in case of reaction in multi-phase food systems.     

Hypertension--the fledgling of modern medical practice

The treatment of hypertension was discovered long before the mechanisms of the disease became known. Only recently has it been appreciated that blood pressure is controlled physiologically in many ways. Hypertension has suddenly achieved celebrity status. It is now recognized as the second leading cause of death in the United States. New programs have made the public aware of it and have prompted many individuals to have their blood pressure checked. Office diagnostic measures usually suffice to determine the presence of the disease. Treatment should generally be initiated with a slow-acting diuretic or with propranolol; other drugs may be added later. Treatment is a lifelong undertaking, and engaging the patient as a partner in the venture by means of home blood pressure measurements and an educational program contributes to its success. Treatment of hypertension is the first step in the prophylaxis of atherosclerosis.     

Emotionally charged earcons reveal affective congruency effects

In the present study, the affective impact of earcons on stimulus classification is investigated. We show, using a picture-categorization task, that the affective connotation of earcons in major and minor mode (representing positive and negative valence, respectively) can be congruent or incongruent with response valence. Twenty participants classified pictures of animals and instruments in 256 trials, using positive and negative Yes or No responses. Together with the pictures, either a chord in major mode or minor mode was played. The affective valence of the chords either did or did not match the valence of responses. Response-time latencies show congruency effects of the matching and non matching sound and response valences, indicating that it is important to carefully investigate human-computer interfaces for potential affective congruency effects, as these can either facilitate or inhibit user performance.     

Energy transfer in LHCII monomers at 77K studied by sub-picosecond transient absorption spectroscopy

Energy transfer from chlorophyll b (Chl b) to chlorophyll a (Chl a) in monomeric preparations of light-harvesting complex II (LHCII) from spinach was studied at 77 K using pump-probe experiments. Sub-picosecond excitation pulses centered at 650 nm were used to excite preferentially Chl b and difference absorption spectra were detected from 630 to 700 nm. Two distinct Chl b to Chl a transfer times, approximately 200 fs and 3 ps, were found. A clearly distinguishable energy transfer process between Chl a molecules occurred with a time constant of 18 ps. The LHCII monomer data are compared to previously obtained LHCII trimer data, and both data sets are fitted simultaneously using a global analysis fitting routine. Both sets could be described with the following time constants: 140 fs, 600 fs, 8 ps, 20 ps, and 2.9 ns. In both monomers and trimers 50% of the Chl b to Chl a transfer is ultrafast (<200 fs). However, for monomers this transfer occurs to Chl a molecules that absorb significantly more toward shorter wavelengths than for trimers. Part of the transfer from Chl b to Chl a that occurs with a time constant of 600 fs in trimers is slowed down to several picoseconds in monomers. However, it is argued that observed differences between monomers and trimers should be ascribed to the loss of some Chl a upon monomerization or a shift of the absorption maximum of one or several Chl a molecules. It is concluded that Chl b to Chl a transfer occurs only within monomeric subunits of the trimers and not between different subunits.     

Chorionic gonadotropin inhibits rat mammary carcinogenesis through activation of programmed cell death

Human chorionic gonadotropin (hCG) inhibits the progression of 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinomas. In order to determine whether this phenomenon was mediated by induction of programmed cell death or apoptosis, 45-day-old virgin Sprague-Dawley rats received 8 mg DMBA/100 g body weight; 20 days later they were injected daily with 100 IU hCG for 40 days (DMBA + hCG group). Age-matched untreated, hCG- and DMBA + saline treated rats were used as controls. Tissues were collected at the time of DMBA administration and at 5, 10, 20 and 40 days of hCG injection. RNA from mammary glands, adenocarcinomas and ovaries was probed for transforming growth factors (TGF) alpha and beta, and the apoptotic genes TRPM2, ICE, bcl2, bcl-XL, bcl-XS, p53 and c-myc. The mammary glands of hCG-treated animals with or without DMBA exhibited elevated expression of TRPM2, ICE, bcl-XS, c-myc and p53; and elevation in the apoptotic index. Mammary adenocarcinomas developed in those animals treated with hCG showed an elevation in the expression of p53, c-myc and ICE genes in comparison with the levels detected in the adenocarcinomas developed by the animals treated with DMBA alone. No significant alterations in the expression of any of the genes tested was observed in ovarian RNAs. These results led us to conclude that hCG induces programmed cell death in the mammary gland initiated in the carcinogenic process, that this process is p53 dependent, and is modulated by c-myc expression. Our data also indicate the possibility that a cell death program dependent on the bcl2 family exists, because of the potential involvement of p53, bcl-XS and Bax in apoptosis. This additional mechanism of tumor inhibition makes hCG treatment a useful approach for the prevention and therapy of breast cancer.