Ventilatory and Pulmonary Vascular Responses to Acute Hypoxia in Patients with Chronic Obstructive Lung Disease

The present study was undertaken to examine the pulmonary vascular and ventilatory responses to acute hypoxia in chronic obstructive lung disease. Pulmonary hemodynamics, minute ventilation (VE) and oxygen uptake (VO2) were serially measured during inhalation of 13 %O2 for 15 min. There was a wide variablility in the pulmonary, vascular response to acute hypoxia. ,The initial increase in VE and the magnitude of change in VO2 were significantly lower in subjects developing a 25 % or great increase in mean pulmonary arterial pressure during hypoxic breathing. These results suggest that the ventilatory response to acute hypoxia plays a significant role in the pulmonary vascular response to acute hypoxia, and blunted initial ventilatory response to acute hypoxia may be a physiological adaptation to enhanced responses of pulmonary vessels

Effect of Acute Hyperoxia and Hypoxia on the Central Blood Volume in Patients with Chronic Pulmonary Diseases

To investigate whether the central blood volume (CBV) reflects the pulmonary vasculature, we measured CBV before and after the inhalation of 100 % or 13 %O2 for 15 min in patients with chronic pulmonary diseases. Using the Stewart-Hamilton technique, we measured CBV using a lung water computer, employing sodium as an indicator. Thirteen patients inhaled 100 % O2, while 8 patients breathed 13 % O2. Hyperoxia increased CBV significantly and the delta change in CBV(△CBV)correlated significantly with the change in total pulmonary resistance index(△TPPI;r=-0.65, p<0.02),the change in mixed venous oxygen tension(△PvO2; r = - 0.58, p < 0.05) and the change in the coefficient of oxygen delivery (△COD;r=0.71, p<0.02). Hypoxic breathing caused little or no change in CBV, but △CBV correlated well with△TPRI(r=-0.74, p<0.05)and△PvO2 (r=0.85,p<0.01)。 Our results suggest that△CBV provides a good index of the pulmonary vascular bed, on which efficient gas-exchange occurs

Feasibility study of a novel wireless localization technique using radiofrequency identification markers for small and deeply located lung lesions

Objectives: To evaluate the safety and efficacy of a novel wireless localization technique that uses radiofrequency identification markers for small and deep lung lesions. Methods: Preliminary use of the device was retrospectively evaluated in 2 Japanese centers. Under general anesthesia, a marker was placed as close as possible to the tumor via computed tomography-guided bronchoscopy in a hybrid operation theater. Surgeons located the marker without lung palpation using a detection probe the tone of which changed to indicate the marker-probe distance. Efficacy was defined as functional marker placement (bronchoscopy time and marker position) and deep margin distance. Results: Twelve markers were placed for 11 lesions (mean size, 6.8 ± 2.7 mm) located at a mean depth from the pleura of 11.4 ± 8.4 mm (range = 0-26.0 mm). Of 12 markers, 7 markers (58.3%) were placed within 10 mm from the lesion in 25.5 ± 14.4 minutes. For the 11 wedge resections, markers were placed at a mean distance of 6.7 mm (range, 0-13.0 mm) from the lesion and a mean distance of 14.4 mm (range, 3.0-42.0 mm) from the pleura. All markers were recovered without complications, and all tumors were resected with negative margins. For 5 lesions >10 mm deep to the pleura (mean depth, 18.9 ± 5.5 mm; range, 11.0-26.0 mm), the median depth of the surgical margin was 11.6 ± 2.1 mm (range, 9.0-14.0 mm). Conclusions: Radiofrequency identification marking was safe and precisely localized small lung lesions, including their depth

Generalised analytical method unravels framework-dependent kinetics of adsorption-induced structural transition in flexible metal–organic frameworks

ゲート型吸着剤はガス分子をどう取り込む？ --サブ秒でのX線回折測定が動的過程を紐解く--. 京都大学プレスリリース. 2023-11-08.Flexible metal–organic frameworks (MOFs) exhibiting adsorption-induced structural transition can revolutionise adsorption separation processes, including CO₂ separation, which has become increasingly important in recent years. However, the kinetics of this structural transition remains poorly understood despite being crucial to process design. Here, the CO₂-induced gate opening of ELM-11 ([Cu(BF₄)₂(4, 4’-bipyridine)₂]n) is investigated by time-resolved in situ X-ray powder diffraction, and a theoretical kinetic model of this process is developed to gain atomistic insight into the transition dynamics. The thus-developed model consists of the differential pressure from the gate opening (indicating the ease of structural transition) and reaction model terms (indicating the transition propagation within the crystal). The reaction model of ELM-11 is an autocatalytic reaction with two pathways for CO₂ penetration of the framework. Moreover, gas adsorption analyses of two other flexible MOFs with different flexibilities indicate that the kinetics of the adsorption-induced structural transition is highly dependent on framework structure

Evaluation of Right Ventricular overload by ^<123>I-MIBG, ^<123>I-BMIPP , and ^<99m>Tc-MIBI

It is important to evaluate the severity of right ventricular (RV) overload in patients with chronic pulmonary diseases or pulmonary thromboembolism because their prognosis depend on the severity of RV overload. Various examination methods have been used to non-invasively evaluate the severity of RV overload. We evaluated the usefulness of recently developed novel radiopharmaceuticals 123I-MIBG, 123I-BMIPP, and 99mTc-MIBI) in patients with chronic respiratory diseases or pulmonary thromboembolism. Myocardial scintigraphy using 1231-MIBG revealed that the ratio of scintillation counts in the interventricular septum (IVS) to those in the left ventricle (LV) correlated negatively with the mean pulmonary arterial pressure (MPAP), suggesting the presence of sympathetic neuropathy due to RV overload. Myocardial scintigraphy using 123I-BMIPP revealed that the ratio of scintillation counts in the RV to those in LV (RV/LV uptake ratio) correlated with MPAP. There was a negative correlation between RV metabolic index [RVMI = (RV/LV ratio of 123I-BMIPP uptake)(RV/LV ratio of 201T1 uptake)] and MPAP. These findings suggested the presence of RV overload-induced fatty acid metabolic disorder. 99iTc-MIBI allows the simultaneous performance of both cardiac pool scintigraphy and myocardial single photon emission computed tomography. RV/LV ratio of 99Tc-MIBI uptake correlated with MPAP. Moreover, RV ejection fraction (RVEF) obtained by right cardiac pool scintigraphy correlated with the RVEF determined by the thermodilution method, suggesting the usefulness of 99mTc-MIBI. Our findings suggest that these radiopharmaceuticals are useful for evaluating the severity of RV overload in patients with chronic respiratory diseases or pulmonary thromboembolism, as well as for evaluating RV overloadinduced metabolic disorders

A Case of Anomalous Origin of the Right Coronary Artery from the Left Sinus of Valsalva - Special Reference to PTCA Procedures and Aspirin Effect to Failed PTCA of the Anomalous Coronary Artery -

An unusual case of a 53-year-old male with a right coronary artery originating from the left sinus of Valsalva is presented. Despite acute myocardial infarction due to occlusion of the aberrant right coronary artery (RCA), PTCA was not immediately performed. After 81 mg/day of aspirin had been administered for 1 month, PTCA to the subtotal stenosis of the RCA resulted in failure due to poor deployment of the guiding catheters complicated by withdrawal and uncrossing of a guiding wire. However, complete recanalization occurred after giving the patient 162 mg/day of aspirin for 8 months. Low dose aspirin was effective in recanalizing the subtotal stenosis after failed PTCA

Pulmonary Hypertension in a Patient with Essential Thrombocythemia

A 67-year-old woman with essential thrombocythemia (ET) developed acute heart failure and marked pulmonary hypertension (PH). No clear cause for the PH could be initially found. We suspected that thrombocytosis might cause PH. Treatments with anticoagulant (heparin and warfarin), platelet- lowering (hydroxyurea), and antiplatelet (ticlopidine) agents resulted in improvement of the clinical, hemodynamic conditions, and the control of platelet counts. We found that the main etiology of PH in the present case might be the pulmonary capillary obstruction from local pulmonary microthrombosis complicated with ET. Although PH associated with ET is uncommon, it should be always considered as a possible cause of dyspnea in patients with ET

Bone fragility via degradation of bone quality featured by collagen/apatite micro-arrangement in human rheumatic arthritis

Although increased bone fragility is a well-recognized consequence in patients with rheumatoid arthritis (RA), the essential cause of degenerate bone strength remains unknown. This study aimed to determine factors contributing to bone dysfunction in RA by focusing on the bone matrix micro-arrangement, based on the preferential orientation of collagen and the related apatite c-axis as a bone quality index. The classical understanding of RA is limited to its severe pathological conditions associated with inflammation-induced bone loss. This study examined periarticular proximal tibiae from RA patients as compared with osteoarthritis (OA) patients as controls. Bone tissue material strength was disrupted in the RA group compared with the control. Collagen/apatite micro-arrangement and vBMD were significantly lower in the RA group, and the rate of decrease in apatite c-axis orientation (−45%) was larger than that in vBMD (−22%). Multiple regression analysis showed that the degree of apatite c-axis orientation (β = 0.52, p = 1.9 × 10−2) significantly contributed to RA-induced bone material impairment as well as vBMD (β = 0.46, p = 3.8 × 10−2). To the best of our knowledge, this is the first report to demonstrate that RA reduces bone material strength by deteriorating the micro-arrangement of collagen/apatite bone matrix, leading to decreased fracture resistance. Our findings represent the significance of bone quality-based analysis for precise evaluation and subsequent therapy of the integrity and soundness of the bone in patients with RA.Ozasa R., Matsugaki A., Ishimoto T., et al. Bone fragility via degradation of bone quality featured by collagen/apatite micro-arrangement in human rheumatic arthritis. Bone, 155, 116261. https://doi.org/10.1016/j.bone.2021.116261

Adrenomedullin is not Related to Acute Hypoxic Pulmonary Vascular Response in Patients with Chronic Respiratory Disease

In the present study, acute hypoxia was induced in 19 patients with chronic respiratory disease to evaluate the corre lation between pulmonary circulation kinetics and adrenomedullin (AM) levels. Using radioimmunoassay (RIA), pulmonary circulation kinetics were evaluated before and after hypoxic loading (13% oxygen for 15 minutes) by determining AM levels in plasma obtained from the pulmonary artery (PA) and the right femoral artery (FA). There were no significant differences in pre-hypoxia plasma AM levels between samples obtained from the PA and FA, and plasma AM levels did not change after hypoxic loading. Subjects were classified into two groups [responders (R) and non-responders (NR) ] to evaluate changes in the mean pulmonary arterial pressure(笆ｳMPAP). There were no changes in AM levels between these two groups in either the PA or FA after hypoxic loading. These results suggest that AM do not appear to be related to hypoxic pulmonary vascular response to acute hypoxic loading in patients with chronic respiratory disease