instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: CTLA4IgG that binds to B7 effectively inhibits the signaling of CD28/B7 pathway and induces antigen-specific T-cell unresponsiveness in vitro and in vivo. We examined whether the development of obliterative bronchiolitis in a murine heterotopic airway transplantation model is T cell dependent and whether CTLA4IgG abrogates the development of obliterative bronchiolitis.', 'Tracheae with main bronchi from C3H/He (H2k), BALB/C (H2d), or C57BL/6 (H2b) mice were transplanted heterotopically into subcutaneous pockets on the backs of BALB/C or BALB/C nu/nu mice on day 0. Recipient mice were untreated or intraperitoneally treated with either CTLA4IgG or human IgG with different time and dose schedules.', 'The development of obliterative bronchiolitis, which leads to luminal obliteration by fibrous tissue in a murine heterotopic airway transplantation model, was T cell dependent and the development of obliterative bronchiolitis was significantly abrogated by the CTLA4IgG treatment. However, the normal ciliated columnar respiratory epithelial cells in allografts were lost and replaced by flattened attenuated epithelial cells even after the CTLA4IgG treatment. We further demonstrated that CTLA4IgG treatment did not result in the induction of donor-specific unresponsiveness.\Question: Does blocking the CD28-B7 T-cell costimulatory pathway abrogate the development of obliterative bronchiolitis in a murine heterotopic airway model?
answer:
We demonstrated that the development of obliterative bronchiolitis in a murine heterotopic airway model involves both CD28/B7-dependent and -independent processes. The luminal obliteration by fibrous tissue is clearly CD28/B7 dependent and can be inhibited by CTLA4IgG. The luminal obliteration of allografted trachea by fibrous tissues and the loss of ciliated columnar respiratory epithelial cells represent distinct disease processes.


question:
Context: Progress in the management of patients with medically intractable epilepsy is impeded because we do not fully understand why pharmacoresistance happens and how it can be predicted. The presence of multiple seizures prior to medical treatment has been suggested as a potential predictor of poor outcome. In the present study, we used an animal model of temporal lobe epilepsy to investigate whether pharmacoresistant rats differ in seizure frequency from pharmacoresponsive animals.', 'Epilepsy with spontaneous recurrent seizures (SRS) was induced by status epilepticus. Frequency of SRS was determined by video/EEG (electroencephalography) monitoring in a total of 33 epileptic rats before onset of treatment with phenobarbital (PB).', 'Thirteen (39%) rats did not respond to treatment with PB. Before treatment with PB, average seizure frequency in PB nonresponders was significantly higher than seizure frequency in responders, which, however, was due to six nonresponders that exhibited > 3 seizures per day. Such high seizure frequency was not observed in responders, demonstrating that high seizure frequency predicts pharmacoresistance in this model, but does not occur in all nonresponders.\Question: Is high seizure frequency prior to antiepileptic treatment a predictor of pharmacoresistant epilepsy in a rat model of temporal lobe epilepsy?
answer:
The data from this study are in line with clinical experience that the frequency of seizures in the early phase of epilepsy is a dominant risk factor that predicts refractoriness. However, resistance to treatment also occurred in rats that did not differ in seizure frequency from responders, indicating that disease severity alone is not sufficient to explain antiepileptic drug (AED) resistance. These data provide further evidence that epilepsy models are useful in the search for predictors and mechanisms of pharmacoresistance.


question:
Context: The incidence of chronic renal disease in women increases with aging, especially after menopause, suggesting that loss of sex hormones may contribute to the development and progression of renal disease. However, the mechanisms by which sex hormones, particularly estrogens, contribute to the disease process are unclear.', 'The present study examined the effects of ovariectomy (OVX) with or without 17 beta-estradiol (E2) supplementation (OVX+E2) on the expression of inducible (iNOS) and endothelial (eNOS) nitric oxide synthase in the kidney.', 'The study was performed in young (4 months [4M]) and aged (12 months [12M]) female Dahl salt-sensitive rats fed a low-sodium (0.1% NaCl) diet. At 3 months of age, the animals were either subjected to sham surgery, OVX, or OVX with implantation of an E2 silastic pellet. The treatments were administered for either 1 or 9 months, rendering the animals 4 months of age or 12 months of age at the time of sacrifice, respectively. Renal expression of NOS isoforms was measured by Western blotting and immunohistochemistry.', 'OVX in the aged rats was associated with 35% and 25% decreases in medullary iNOS (mean [SEM] relative optical density [ROD]: 4M OVX, 1.81 [0.14] vs 12M OVX, 1.17 [0.16]; P < 0.05) and eNOS (mean ROD: 4M OVX, 1.91 [0.09] vs 12M OVX, 1.43 [0.15]; P < 0.05) protein expression, respectively, and a 25-fold increase in the abundance of CD68-positive cells, indicating macrophage infiltration (mean cells/mm2: 4M OVX, 1.18 [0.09] vs 12M OVX, 30.0 [0.74]; P < 0.001). E2 supplementation either partially or completely attenuated these changes in iNOS (mean ROD: 4M OVX+E2, 2.26 [0.08] vs 12M OVX+E2, 1.70 [0.09]; P < 0.05), eNOS (mean ROD: 4M OVX+E2, 2.03 [0.07] vs 12M OVX+E2, 1.77 [0.11]; P = NS) and CD68 (mean cells/mm2: 4M OVX+E2, 1.46 [0.07] vs 12M OVX+E2, 6.87 [1.6]; P < 0.01) associated with OVX in the aging kidney.\Question: Is age-related renal disease in female Dahl salt-sensitive rats attenuated with 17 beta-estradiol supplementation by modulating nitric oxide synthase expression?
answer:

These data suggest that ovarian E2 loss with aging may contribute to the development of age-related renal disease through downregulation of iNOS and eNOS protein abundance and increased renal inflammation in this animal model. Furthermore, E2 supplementation may be protective in the aging kidney by attenuating these changes.