Precipitation of poly(acrylic acid) by added salts has been investigated under various conditions. The PAA was neutralized to various degrees of ionization α by tetra‐n‐butyl ammonium hydroxide. The minimum salt concentration C̄s at which precipitation occurs was determined at various polymer concentration Cp, temperature T, and α. The amount of bound cations to polyions, the change in ion hydration, and the polymer expansion near C̄s were estimated by conductance, refractive index, and viscosity measurements, respectively. It is concluded that there are two kinds of precipitation; The L type which satisfies the relation C̄s ≐ αCp and occurs at high α due to cation binding to the polyions, and the H type in which C̄s is independent of Cp and which appears at low α with salts other than those having large ions. This classification of the precipitation is justified also by the C̄s – T relation; in the L type, C̄s is nearly independent of T, and in the H type C̄s increases with T. At intermediate α‐values pronounced specificities of salt ions are found in the precipitation; at α = 0.25, with Mg2+ the H type appears, while with Ba2+ or Ca2+ the L type appears, although all of these divalent cations are bound to polyions to the same degree. This is due to the difference in the hydration of the polyion‐cation complexes. In the L‐type the formation of cation bindings, such as salt bridge, makes the polymer hydrophobic, while in the H type highly concentrated salt ions render the polymer solution unstable by changing the arrangement of the water molecule.

The physical feature of the G‐F transformation of action caused by a small amount of magnesium ions was investigated by measuring flow birefringence, light scattering, viscosity, and sedimentation of action solutions at various concentrations of actin and magnesium ions. All experimental results indicate that the G‐F transformation of actin can be regarded as a reversible fibrous condensation. When the concentration of actin is increased at a constant concentration of magnesium ions, fibrous aggregates of actin molecules, F‐actins, can be formed only above a critical actin concentration which is determined by the condition of medium and decreases rapidly with increasing concentration of magnesium ions. Above the critical concentration, all of the excess active actin molecules are transformed into F‐actins. These F‐actins are coexisting with active (G‐)actin molecules, the concentration of which is independent of the concentration of F‐actin and equal to the concentration of active actin at the critical point. The state of apparent units of F‐actins in solution is also determined by the condition of medium and independent of the concentration. With increasing concentration of magnesium ions, the apparent units of F‐actin become longer and longer and their thickness increases. Small globular aggregates are always observed below the critical point of formation of long fibrous aggregates. These experimental results show qualitative agreement with theoretical results obtained by one of the authors on fibrous and globular aggregations of charged macromolecules.

BackgroundRecent studies suggest that coexistence of chronic obstructive pulmonary disease (COPD) might be independently related to a worse prognosis for lung cancer. However, because data on the substantial prevalence of COPD and its severity in Asian lung cancer patients remain limited, clinical impact of prevalence and severity of COPD among the population has not been fully evaluated. Furthermore, patients with COPD often have comorbidities. Thus, whether the decision-making process for therapeutic management of lung cancer patients might be independently affected by COPD remains elusive.MethodsClinical impact of prevalence and severity of COPD were evaluated in 270 Japanese patients with newly diagnosed lung cancer who were sequentially registered and underwent bronchoscopy from August 2010 to July 2012 at Nagoya University hospital. Furthermore, to explore whether or not the severity of airflow obstruction might affect the decision to propose thoracic surgery with curative intent, we evaluated data from patients with lung cancer at stage 1A to 3A who underwent spirometry and bronchoscopy.ResultsThe prevalence rate of COPD was 54.4% among Japanese patients with lung cancer who underwent bronchoscopy. The incidence of Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2 was significantly higher than that of GOLD grade 3. Although COPD-related comorbidities were not independent factors for proposing thoracic surgery, the number of thoracic surgeries performed was significantly less in the COPD group than the non-COPD group. Multivariate analysis showed that more severe airway obstruction, advanced clinical staging, and higher age, were independent factors associated with the decision on thoracic surgery.ConclusionsWe demonstrated a high prevalence of COPD among Japanese lung cancer patients. Based on the knowledge that severity of COPD is one of the most important factors in the therapeutic decision, comprehensive assessment of COPD at bronchoscopy might allow us to implement the optimum management for lung cancer patients.

Objective Endobronchial ultrasonography with a guide sheath (EBUS-GS) and virtual bronchoscopic navigation (VBN) improves the diagnostic yield in patients with peripheral pulmonary lesions (PPLs). Most previous reports on EBUS-GS-guided transbronchial biopsy (TBB) have included patients with benign and malignant diseases. We aimed to determine the factors that predicted a successful diagnosis by EBUS-GS-guided TBB diagnostic in patients with small peripheral lung cancer, with a focus on the high-resolution computed tomography (HRCT) findings before bronchoscopy. Methods We retrospectively reviewed the medical records of 173 consecutive patients with 175 small (! 30 mm) PPLs who were diagnosed with primary lung cancer between June 2010 and October 2013 at Nagoya University Hospital. All patients underwent EBUS-GS-guided TBB with VBN using a ZioStation computer workstation (Ziosoft, Osaka, Japan). We analyzed the patient characteristics, HRCT findings, diagnostic yield, and the diagnostic factors in small peripheral lung carcinoma. Results The EBUS probe position was within the PPL in 83 of the 175 lesions (47%) and 112 (64.0%) cases were successfully diagnosed by EBUS-GS-guided TBB. A univariate analysis revealed that the following factors were associated with a significantly higher diagnostic yield: CT bronchus sign positivity, a lesion of >20 mm in diameter, a solid nodule, and a probe position that was within the lesion. The following factors were not significant: the lesion location, the number of biopsies, and the lung cancer histology. A multivariate analysis revealed that the following factors significantly affected the diagnostic yield: CT bronchus sign positivity [odds ratio (OR) =2.479]; a probe position that was within the lesion (OR=2.542); and a solid nodule (OR=2.304). Conclusion The significant factors that were significantly associated with a successful diagnosis using EBUS-GS-guided TBB in small peripheral lung carcinoma were as follows: CT bronchus sign positivity, a solid nodule, and a probe position that was within the lesion.

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