Severe mitral annular calcification(MAC)is frequently seen in patients with advanced age and chronic kidney disease,but it is rare in rheumatic heart disease(RHD).We hereby report a case of 45-year-old female with chr...Severe mitral annular calcification(MAC)is frequently seen in patients with advanced age and chronic kidney disease,but it is rare in rheumatic heart disease(RHD).We hereby report a case of 45-year-old female with chronic RHD,who had severe MAC and mitral regurgitation.Fluoroscopy revealed a "crown"-like severe calcification of the mitral annulus.Autopsy of the heart revealed a calcified posterior mitral annulus,fused commissures,and calcified nodules at the atrial aspect of the mitral valve.展开更多
Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and phy...Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and physiological viewpoints. Model A of Weibel in which dichotomously branching airways are incorporated should be used for analyzing gas mixing in conducting and acinar airways. Acinus of Loeschcke is taken as an anatomical gas-exchange unit.Although it is difficult to define functional gas-exchange unit in a way entirely consistent with anatomical structures, acinus of Aschoff may serve as a functional gas-exchange unit in a first approximation. Based on anatomical and physiological perspectives, the multiple inert-gas elimination technique is thought to be highly effective for predicting ventilation-perfusion heterogeneity between acini of Aschoff under steady-state condition. Changes in effective alveolar P_(O2), the most important parameter in classical gas-exchange theory, are coherent with those in mixed alveolar P_(O2) decided from the multiple inert-gas elimination technique. Therefore, effective alveolar-arterial P_(O2) difference is considered useful for assessing gas-exchange abnormalities in lung periphery.However, one should be aware that although alveolar-arterial P_(O2) difference sensitively detects moderately low ventilation-perfusion regions causing hypoxemia, it is insensitive to abnormal gas exchange evoked by very low and high ventilation-perfusion regions. Pulmonary diffusing capacity for CO (D_(LCO))and the value corrected for alveolar volume (V_(AV)), i.e., D_(LCO)/V_(AV) (K_(CO)), are thought to be crucial for diagnosing alveolar-wall damages. D_(LCO)-related parameters have higher sensitivity to detecting abnormalities in pulmonary microcirculation than those in the alveolocapillary membrane. We would like to recommend four categories derived from combining behaviors of D_(LCO) with those of K_(CO) for differential diagnosis on anatomically morbid states in alveolar walls:type-1abnormality defined by decrease in both D_(LCO) and K_(CO); type-2 abnormality by decrease in D_(LCO) but increase in K_(CO); type-3 abnormality by decrease in D_(LCO) but restricted rise in K_(CO); and type-4 abnormality by increase in both D_(LCO) and K_(CO).展开更多
“Carpe diem”(enjoy the day)is a famous quotation of the Roman poet Horace,and these two words in a complementary way refer both to the logistics and to the semantics of human time(Zhao et al.,2022).Every day is an e...“Carpe diem”(enjoy the day)is a famous quotation of the Roman poet Horace,and these two words in a complementary way refer both to the logistics and to the semantics of human time(Zhao et al.,2022).Every day is an evolutionary adaptation to the geophysical cycle of 24 hours;this circadian rhythm(Aschoff,1965)is an example of the logistics of human time together with other temporal phenomena having shorter durations,as reflected in“time windows”(Bao et al.,2015).The logistic basis of temporal processing in human behavior is the necessary but not sufficient basis of how we(hopefully)enjoy the day,how we use our time efficiently,how we give meaning to our personal time,and how we experience temporal phenomena.The semantics of human time is reflected in temporal satisfaction or dissatisfaction,in the joy of having achieved something or the frustration of failure,and also in procrastination,in the experienced scarcity of time,or in boredom.展开更多
文摘Severe mitral annular calcification(MAC)is frequently seen in patients with advanced age and chronic kidney disease,but it is rare in rheumatic heart disease(RHD).We hereby report a case of 45-year-old female with chronic RHD,who had severe MAC and mitral regurgitation.Fluoroscopy revealed a "crown"-like severe calcification of the mitral annulus.Autopsy of the heart revealed a calcified posterior mitral annulus,fused commissures,and calcified nodules at the atrial aspect of the mitral valve.
文摘Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and physiological viewpoints. Model A of Weibel in which dichotomously branching airways are incorporated should be used for analyzing gas mixing in conducting and acinar airways. Acinus of Loeschcke is taken as an anatomical gas-exchange unit.Although it is difficult to define functional gas-exchange unit in a way entirely consistent with anatomical structures, acinus of Aschoff may serve as a functional gas-exchange unit in a first approximation. Based on anatomical and physiological perspectives, the multiple inert-gas elimination technique is thought to be highly effective for predicting ventilation-perfusion heterogeneity between acini of Aschoff under steady-state condition. Changes in effective alveolar P_(O2), the most important parameter in classical gas-exchange theory, are coherent with those in mixed alveolar P_(O2) decided from the multiple inert-gas elimination technique. Therefore, effective alveolar-arterial P_(O2) difference is considered useful for assessing gas-exchange abnormalities in lung periphery.However, one should be aware that although alveolar-arterial P_(O2) difference sensitively detects moderately low ventilation-perfusion regions causing hypoxemia, it is insensitive to abnormal gas exchange evoked by very low and high ventilation-perfusion regions. Pulmonary diffusing capacity for CO (D_(LCO))and the value corrected for alveolar volume (V_(AV)), i.e., D_(LCO)/V_(AV) (K_(CO)), are thought to be crucial for diagnosing alveolar-wall damages. D_(LCO)-related parameters have higher sensitivity to detecting abnormalities in pulmonary microcirculation than those in the alveolocapillary membrane. We would like to recommend four categories derived from combining behaviors of D_(LCO) with those of K_(CO) for differential diagnosis on anatomically morbid states in alveolar walls:type-1abnormality defined by decrease in both D_(LCO) and K_(CO); type-2 abnormality by decrease in D_(LCO) but increase in K_(CO); type-3 abnormality by decrease in D_(LCO) but restricted rise in K_(CO); and type-4 abnormality by increase in both D_(LCO) and K_(CO).
文摘“Carpe diem”(enjoy the day)is a famous quotation of the Roman poet Horace,and these two words in a complementary way refer both to the logistics and to the semantics of human time(Zhao et al.,2022).Every day is an evolutionary adaptation to the geophysical cycle of 24 hours;this circadian rhythm(Aschoff,1965)is an example of the logistics of human time together with other temporal phenomena having shorter durations,as reflected in“time windows”(Bao et al.,2015).The logistic basis of temporal processing in human behavior is the necessary but not sufficient basis of how we(hopefully)enjoy the day,how we use our time efficiently,how we give meaning to our personal time,and how we experience temporal phenomena.The semantics of human time is reflected in temporal satisfaction or dissatisfaction,in the joy of having achieved something or the frustration of failure,and also in procrastination,in the experienced scarcity of time,or in boredom.
