The side chains responsible for the dimerization of the estradiol receptor by ionic bonds are lost in a 17 kDa fragment extending downstream from aa 303

Fragments of 32, 26 and 17 kDa of the porcine estradiol receptor were prepared, all of which contain the ligand-binding site. While dimers of the 32 and 26 kDa fragments like those of intact receptor can be dissociated by protonation, the dimer of the 17 kDa fragment obtained by trypsination of the 26 kDa fragment is resistant to lowering the pH from 7.0 to 6.5 and below. Its dissociation can be achieved by 0.5 M MgCl2 at pH 7.0. All fragments are recognized by the MAB 13H2 in Western blots. The antibody also reacts with native receptor and the three fragments, both in their monomer and dimer states. The combining ratios of antibody with receptor, or its fragments, in the monomer and dimer states and the weakening of the estradiol-receptor bond by antibody attachment support the back to back and head to toe model of receptor dimers.     

Whole-body kinetics and dosimetry of L-3--123I-iodo-alpha-methyltyrosine

BACKGROUND: Desflurane anesthesia can produce cerebral metabolic depression and increase cerebral blood flow. We evaluated the effect of desflurane on brain tissue oxygen pressure (PO2), carbon dioxide pressure (PCO2) and pH during neurosurgery. METHODS: Following a craniotomy, the dura was opened and a Paratrend 7 sensor, which measures PO2, PCO2, pH and temperature, was inserted into brain tissue. In 6 control patients in group 1, anesthesia was maintained constant with 3% end-tidal desflurane over 60 min, including a 30-min stabilization period. In group 2, 9 patients were ventilated with 3% desflurane under baseline conditions. After a 30-min stabilization period, baseline tissue gases and pH were measured and end-tidal desflurane was increased to 6% and then 9% for 15-min intervals. Mean arterial pressure (MAP) was maintained with intravenous phenylephrine. RESULTS: Under baseline conditions, cardiovascular and brain tissue measures were similar between the 2 groups. Increasing end-tidal desflurane from 3% to 9% produced burst-suppression EEG in all patients and significantly increased tissue PO2 and pH and decreased PCO2. No parameters changed significantly in the control group during steady-state anesthesia. CONCLUSION: These results show that 9% desflurane can improve brain tissue metabolic status before temporary brain artery occlusion if cerebral perfusion pressure is maintained. This may be particularly important in patients with symptoms of ischemia before surgery.     

Time-dependent differential changes of immune function in rats exposed to chronic intermittent noise

Noise is a highly relevant environmental and clinical stressor. Compared to most other experimental stressors, noise is a modest activator of neuroendocrine pathways that mimic the situation in human health where neuroendocrine activation by environmental stressors is often absent or difficult to establish. Little is known about the effects of noise exposure on the immune system. In the present work, the effects of a low-intensity chronic intermittent unpredictable noise regimen on various parameters of immune function was studied. Male wistar rats were exposed to a randomized noise protocol (white noise, 85 dB, 2-20 kHz) for 10 h per day, 15 min per h over a total period of 3 weeks. Control animals were exposed to ambient sound only. Immune function was monitored after 24 h, 7 days, and 21 days of noise exposure. Noise induced several significant changes in immune function in a time-dependent differential pattern involving both immunosuppression and immunoenhancement. After 24 h, serum IgM levels were increased and peripheral phagocytic activity was decreased. Splenic lymphocytic proliferation to mitogens was significantly decreased after 7 days, but slightly elevated after 3 weeks. The activity of splenic NK cells was increased significantly after 24 h and 7 days, but suppressed after 3 weeks. These results show that various parameters of immune function are affected differentially over time in a period of chronic mild noise stress, possibly due to sequential activation of different physiological mechanisms.     

Thyroid hormones in dairy calves after birth and in the first days of life. Amplitude of variation, maternal-fetal relationships and reaction patterns specific to the individual

Dairy calves and their dams from the dairy herd of the institute were used for this investigation. Calvings were watch carefully and jugular venous blood samples taken immediately after delivery from the cow and the calf and in the calf at 24 hours and at 48 hours of postnatal age as well were analyzed for T4, FT4, T3 and FT3 by luminescence enzyme immunoassay (LEIA). Higher thyroid values in calves than in their dams could be found increasing short after birth and reaching their highest level within 24 hours of postnatal life. The individual thyroid hormone values at birth and at 24 hours and at 48 hours of age are well correlated meaning the changes during the first days are specific for each calf. Strong correlation between the thyroid hormone values of the cows and those of the calves could be found. Mean values of thyroid hormones were significantly higher in female than in male calves all time but not different in the dams of these calves.