Biomedical subjects
Publications and source records attributed to N Block.
Functionalists about consciousness identify consciousness with a role; physicalists identify consciousness with an implementer of that role. The global workspace theory of consciousness fits the functionalist perspective, but the physicalist sees consciousness as a biological phenomenon that implements global accessibility.
Effects of sitaxsentan (TBC11251), an orally active, highly selective antagonist of endothelin A receptors, were examined on the development and maintenance of pulmonary hypertension, pulmonary vascular remodeling, and cardiac hypertrophy in the rat. The pulmonary vasoconstrictor response to acute hypoxia (10% O(2)for 90 min) was prevented with sitaxsentan (5 mg/kg infused iv 10 min prior to the onset of hypoxia) while BQ-788 (a specific endothelin B receptor antagonist) was without effect. The same dose of sitaxsentan delivered iv 50 min after the onset of hypoxia reversed the established pulmonary vasoconstriction. In a 2-week model of hypoxia using 10% O(2), treatment with sitaxsentan (15 mg/kg per day in drinking water) attenuated pulmonary hypertension and the associated right ventricular hypertrophy, and prevented the remodeling of small pulmonary arteries (50-100 microM) without affecting systemic arterial blood pressure or heart rate. Institution of sitaxsentan treatment (15 and 30 mg/kg per day in drinking water) for 4 weeks after 2 weeks of untreated hypoxia produced a significant, dose dependent reversal of the established pulmonary hypertension, right heart hypertrophy, and pulmonary vascular remodeling despite continued hypoxic exposure. Sitaxsentan blocked increased plasma endothelin levels in the prevention protocol but did not affect the established elevated levels in the intervention study. Sitaxsentan dose dependently (10 and 50 mg/kg per day in the drinking water) attenuated right ventricular systolic pressure, right heart hypertrophy, and pulmonary vascular remodeling observed 3 weeks after a single subcutaneous injection of monocrotaline. These findings support the hypothesis that endothelin-1 plays a significant role in the development of pulmonary hypertension, pulmonary vascular remodeling, and the associated cardiac hypertrophy, and further suggest that specific endothelin-A receptor blockade may be useful in the treatment of pulmonary hypertension of diverse etiologies.
OBJECTIVES: To review the outcome of therapy with maximal androgen blockade and compare the efficacy and safety of bicalutamide and flutamide, each used in combination with luteinizing hormone-releasing hormone analogue (LHRH-A) therapy, in patients with untreated metastatic (Stage D2) prostate cancer. METHODS: Randomized, double-blind (for antiandrogen therapy), multicenter study with a 2 x 2 factorial design. A total of 813 patients were allocated 1:1 to bicalutamide (50 mg once daily) or flutamide (250 mg three times daily), plus 2:1 to goserelin acetate (3.6 mg every 28 days) or leuprolide acetate (7.5 mg every 28 days). RESULTS: At the time of analysis (median follow-up, 49 weeks), bicalutamide plus LHRH-A was associated with a statistically significant improvement in time-to-treatment failure, the primary endpoint, when compared with flutamide plus LHRH-A. The results with longer follow-up (median, 95 weeks) support previous findings of an improved time-to-treatment failure with bicalutamide plus LHRH-A; however, the difference between groups was not statistically significant. A treatment failure endpoint was reached by 68% of patients in the bicalutamide plus LHRH-A group, compared with 72% of patients in the flutamide plus LHRH-A group. The hazard ratio of bicalutamide plus LHRH-A to flutamide plus LHRH-A was 0.87 (95% confidence interval [CI], 0.74-1.03; P = 0.10). The upper one-sided 95% confidence limit for survival was 1.00, meeting the definition for equivalence (< 1.25). With longer follow-up, overall mortality was 34%, with equivalent survival between groups: 32% of patients in the bicalutamide plus LHRH-A group died, compared with 35% in the flutamide plus LHRH-A group. The hazard ratio of bicalutamide plus LHRH-A to flutamide plus LHRH-A was 0.88 (95% CI, 0.69-1.11; P = 0.29). The upper one-sided 95% confidence limit for survival was 1.07, meeting the definition for equivalence (< 1.25). Diarrhea occurred in 24% of patients in the flutamide plus LHRH-A group compared with 10% of patients in the bicalutamide plus LHRH-A group (P < 0.001). CONCLUSIONS: In patients with metastatic prostate cancer, bicalutamide plus LHRH-A is effective and well tolerated. Because of its efficacy and tolerability profile, together with its convenient once-daily dosing formulation, bicalutamide represents a prime candidate for antiandrogen of first choice in combination with LHRH-A therapy in the treatment of men with metastatic prostate cancer.
There are two concepts of consciousness, access consciousness and phenomenal consciousness. But just as the concepts of water and H2O are different concepts of the same thing, so the two concepts of consciousness might come to the same thing in the brain. Some recent papers by Crick and Koch raise issues that suggest that these two concepts of consciousness might have different (though overlapping) neural correlates, despite Crick and Koch's implicit rejection of this idea.
The Bell Curve revives and elaborates an argument given by Jensen to the effect that facts about heritability of IQ in whites dictate that blacks are genetically inferior in IQ. But clarification of the concept of heritability shows that this reasoning is fallacious. Heritability is an uninteresting measure that only misleads us about race.
OBJECTIVES: To compare the efficacy and safety of bicalutamide and flutamide, each used in combination with luteinizing hormone-releasing analogue (LHRH-A) therapy, in patients with untreated metastatic (Stage D2) prostate cancer. METHODS: Randomized, double-blind (for antiandrogen therapy), multicenter study with a 2 x 2 factorial design. Eight hundred thirteen patients were allocated 1:1 to bicalutamide (50 mg once daily) and flutamide (250 mg three times daily) and 2:1 to goserelin acetate (3.6 mg every 28 days) and leuprolide acetate (7.5 mg every 28 days). RESULTS: With a median duration of follow-up of 49 weeks, time to treatment failure, the primary endpoint, was significantly (P = 0.005) better for the bicalutamide plus LHRH-A group than for the flutamide plus LHRH-A group. Patients in the flutamide plus LHRH-A group were 34% more likely to fail treatment over the given time period, as indicated by the hazard ratio of 0.749 (95% confidence interval, 0.61 to 0.92) for bicalutamide plus LHRH-A to flutamide plus LHRH-A. Results for secondary endpoints (survival, quality of life, and subjective response) were similar between groups. Diarrhea occurred in 24% of patients in the flutamide plus LHRH-A group, compared with 10% of patients in the bicalutamide plus LHRH-A group (P < 0.001). CONCLUSIONS: In patients with metastatic prostate cancer, bicalutamide plus LHRH-A is well tolerated and provides superior efficacy to flutamide plus LHRH-A with respect to time to treatment failure. Assessment of the effects of these regimens on longer term survival requires additional time for follow-up.
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