Effect of Addition of Tannin Extract from Underutilized Resources on Allergenic Proteins, Color and Textural Properties of Egg White Gels

Tannins, present in numerous plants, exhibit a binding affinity for proteins. In this study, we aimed to exploit this property to reduce the concentration of allergenic egg white proteins. Tannins were extracted, using hot water, from the lyophilized powder of underutilized resources, such as chestnut inner skin (CIS), young persimmon fruit (YPF), and bayberry leaves (BBLs). These extracts were then incorporated into an egg white solution (EWS) to generate an egg white gel (EWG). Allergen reduction efficacy was assessed using electrophoresis and ELISA. Our findings revealed a substantial reduction in allergenic proteins across all EWGs containing a 50% tannin extract. Notably, CIS and BBL exhibited exceptional efficacy in reducing low allergen levels. The addition of tannin extract resulted in an increase in the total polyphenol content of the EWG, with the order of effectiveness being CIS > YPF > BBL. Minimal color alteration was observed in the BBL-infused EWG compared to the other sources. Additionally, the introduction of tannin extract heightened the hardness stress, with BBL demonstrating the most significant effect, followed by CIS and YPF. In conclusion, incorporating tannin extract during EWG preparation was found to decrease the concentration of allergenic proteins while enhancing antioxidant properties and hardness stress, with BBL being particularly effective in preventing color changes in EWG.

Variations in the Protein Hydration and Hydrogen-Bond Network of Water Molecules Induced by the Changes in the Secondary Structures of Proteins Studied through Near-Infrared Spectroscopy

This study investigated how the secondary structural changes of proteins in aqueous solutions affect their hydration and the hydrogen-bond network of water molecules using near-infrared (NIR) spectroscopy. The aqueous solutions of three types of proteins, i.e., ovalbumin, β-lactoglobulin, and bovine serum albumin, were denatured by heating, and changes in the NIR bands of water reflecting the states of hydrogen bonds induced via protein secondary structural changes were investigated. On heating, the intermolecular hydrogen bonds between water molecules as well as between water and protein molecules were broken, and protein molecules were no longer strongly bound by the surrounding water molecules. Consequently, the denaturation was observed to proceed depending on the thermodynamic properties of the proteins. When the aqueous solutions of proteins were cooled after denaturation, the hydrogen-bond network was reformed. However, the state of protein hydration was changed owing to the secondary structural changes of proteins, and the variation patterns were different depending on the protein species. These changes in protein hydration may be derived from the differences in the surface charges of proteins. The elucidation of the mechanism of protein hydration and the formation of the hydrogen-bond network of water molecules will afford a comprehensive understanding of the protein functioning and dysfunctioning derived from the structural changes in proteins.

Analytical chemistry toward on-site diagnostics

Analytical Chemistry, through quantitative and/or qualitative analysis (identification), is a discipline that involves the development of methodologies and the exploration of new principles to obtain answers to given problems. In situ analysis techniques have attracted attention for its ability to elucidate phenomena occurring and to evaluate amount of a certain component in substances at real time and biological samples as applications of such analysis technology. Lots of techniques have been performed to understand the fundamental phenomena in varied fields such as X-ray, vibrational, and electrochemical impedance spectroscopies and also analytical reagents that enable to semi-quantitative analysis just observation. In fact, applying various in situ techniques in analytical chemistry expands to the medical diagnosis, which leads to be able to detect early diseases. Here, we describe some of previous researches in many fields such as electrochemical device for energy storage, biology, environment, and pathology and briefly introduce our recent challenges to analytical chemistry toward the on-site diagnosis.

Removal of astringency from persimmon paste via polysaccharide treatment

Non-astringent persimmon (Diospyros kaki Thunb.) paste is typically produced by treating astringent persimmon fruit with alcohol or dry ice (to remove tannins) followed by abrasion. However, considering the large yield of astringent persimmons harvested in a short time, this long, laborious method has hindered the use of persimmon paste in food processing. Herein, the addition of polysaccharides was used to produce a non-astringent persimmon paste while maintaining its quality. Among the nine evaluated polysaccharides, high- (HM) and low-methoxyl (LM) pectins, carrageenan, xanthan gum, and sodium alginate exhibited high astringency removal efficiencies. No astringency recurrence was observed after freezing when HM or LM pectin, guar gum, carrageenan, or sodium alginate were added. Moreover, the addition of HM pectin, or LM pectin, or sodium alginate prevented astringency upon heating. Additionally, guar, xanthan, tara gum, or carrageenan effectively inhibited syneresis. Thus, high-quality pastes could be easily and efficiently produced using a combination of polysaccharides.

Development of an amino acid sequence-dependent analytical method for peptides using near-infrared spectroscopy

We aimed to develop an amino acid sequence-dependent analytical method using near-infrared (NIR) spectroscopy. The possibility for monitoring peptide synthesis was proved with very high accuracies.

In situ assessment of mitochondrial respiratory activity and lipid metabolism of mouse oocytes using resonance Raman spectroscopy

This study aimed to develop a method to determine the degree of oocyte maturation in metaphase II in situ based on the balance between mitochondrial respiratory activity and lipid metabolism using resonance Raman spectroscopy. A decrease in the respiratory activity of overmatured oocytes was indicated by the reduced intensities of the resonance Raman bands corresponding to reduced cytochrome c in the cytoplasm. Moreover, the increased lipid concentration in overmature oocytes indicated lower lipid metabolism with a decreased mitochondrial function. New indexes were defined in terms of the ratios of the representative Raman peak intensities of reduced cytochrome c (750 and 1127 cm^-1) to those of lipids (1438 cm^-1 ) and they successfully classify the oocytes into groups based on their quality, which varied with their maturation degree. The high development rate of embryos that were fertilized in vitro after laser irradiation showed that laser irradiation was noninvasive to oocytes. The evaluation of two factors in situ, the active respiration and lipid metabolism, means to catch the most fundamental biochemical reactions of life activities. Our results demonstrate the potential application of resonance Raman spectroscopy as a new, noninvasive, and universal cell evaluation technology, for not only oocytes but also more general cells such as somatic cells and iPS cells.

Effect of Raman exposure time on the quantitative and discriminant analyses of carotenoid concentrations in intact tomatoes

The significant worldwide expansion of the health food market, which includes functional fruits and vegetables, requires a simple and rapid analytical method for the on-site analysis of functional components, such as carotenoids, in fruits and vegetables, and Raman spectroscopy is a powerful candidate. Herein, we clarified the effects of Raman exposure time on quantitative and discriminant analysis accuracies. Raman spectra of intact tomatoes with various carotenoid concentrations were acquired and used to develop partial least squares regression (PLSR) and partial least squares discriminant analysis (PLS-DA) models. The accuracy of the PLSR model was superior (R² = 0.87) when Raman spectra were acquired 10 s, but decreased with decreasing exposure time (R² = 0.69; 0.7 s). The accuracy of the PLS-DA model was unaffected by exposure time (hit rate: 90%). We conclude that Raman spectroscopy combined with PLS-DA is useful for the on-site analysis of carotenoids in fruits and vegetables.

Method of Monitoring the Number of Amide Bonds in Peptides Using Near-Infrared Spectroscopy

Using near-infrared (NIR) spectroscopy, we aimed to develop a method of monitoring the increasing number of amide bonds with the elongation of the chain length of peptides. Because peptide synthesis can be monitored by evaluating the increasing number of amide bonds with dehydration occurring between amino acids, polyglycine, which has the simplest structure among polyamino acids, was studied, and the key bands whose absorption intensities increased with the elongation of the chain length, such as the bands attributed to glycine, diglycine, triglycine, and tetraglycine, were searched. The bands due to the combinations of the amide A and amide II/III modes in the region of 5000-4500 cm^-1 were revealed to be good candidates for key bands, their second derivative intensities increased as the number of amide bonds increased, regardless of pH, solvent species, and the presence of protecting groups. The number of amide bonds was evaluated by a partial least square regression using the abovementioned combination bands, and a calibration model with a high determination coefficient (≥0.99) was constructed. These results not only have demonstrated the usefulness of NIR spectroscopy as a process analytical technology tool for the process of synthesizing the peptide in a microflow reactor but also have provided basic knowledge for analyzing amide bonds in the NIR spectra of proteins, polyamino acids, polypeptides, and polyamides.

Iodine staining as a useful probe for distinguishing insulin amyloid polymorphs

It is recently suggested that amyloid polymorphism, i.e., structural diversity of amyloid fibrils, has a deep relationship with pathology. However, its prompt recognition is almost halted due to insufficiency of analytical methods for detecting polymorphism of amyloid fibrils sensitively and quickly. Here, we propose that iodine staining, a historically known reaction that was firstly found by Virchow, can be used as a method for distinguishing amyloid polymorphs. When insulin fibrils were prepared and iodine-stained, they exhibited different colors depending on polymorphs. Each of the colors was inherited to daughter fibrils by seeding reactions. The colors were fundamentally represented as a sum of three absorption bands in visible region between 400 and 750 nm, and the bands showed different titration curves against iodine, suggesting that there are three specific iodine binding sites. The analysis of resonance Raman spectra and polarization microscope suggested that several polyiodide ions composed of I₃⁻ and/or I₅⁻ were formed on the grooves or the edges of β-sheets. It was concluded that the polyiodide species and conformations formed are sensitive to surface structure of amyloid fibrils, and the resultant differences in color will be useful for detecting polymorphism in a wide range of diagnostic samples.

Assessment of Embryonic Bioactivity through Changes in the Water Structure Using Near-Infrared Spectroscopy and Imaging

We explored the influence of embryonic bioactivity on the water structure using near-infrared (NIR) spectroscopy and imaging. Four groups of Japanese medaka fish (Oryzias latipes) eggs were studied: (a) one group of eggs was activated by fertilization, and (b-d) three groups of eggs were not activated because embryogenesis was stopped or not started by (b) culturing under cold temperature, (c) instant freezing, or (d) lack of fertilization. The yolks of the activated eggs contained higher proportions of weakly hydrogen bonded water than those of nonactivated eggs. A possible factor responsible for the significant changes in the water structure was revealed to be a protein secondary structural change from an α-helix to a β-sheet in the activated eggs. NIR images of the activated eggs successfully visualized the water structural variation in the yolk with a higher proportion of weak hydrogen bonds due to the activation of embryonic development. The embryogenic activity could be assessed through the water hydrogen bond network, which is affected by newly generated proteins with different secondary structures.

Theoretical Modeling of Electronic Structures of Polyiodide Species Included in α-Cyclodextrin

The molecular mechanism of blue color formation in an iodine-starch reaction is studied by employing the iodine-α-cyclodextrin (α-CD) complex as a practical model system that resembles the structural properties of the blue amylose-iodine complex. To this end, we construct, using the quantum chemistry method, a molecular model of the complex (I₅^-/Li⁺/2α-CD) that consists of one I₅^-, two molecules of α-CD, and a lithium cation, and this model is employed as a basic unit in constructing the structural models of polyiodide ions (I₅^-)_n. The initial structure in the geometry optimization is adopted from the α-CD-iodine complex structure obtained from the X-ray crystallography study. The structural models of (I₅^-)_n are built by adding the basic unit n times along the crystal axis and by optimizing the structure using quantum mechanics/molecular mechanics (QM (iodine)/MM (α-CD)) calculations. The electronic absorption spectra of the resulting model structures are calculated by time-dependent density functional theory (TD-DFT). We find that I₅^- acts as a basic unit of coloration in the visible region. The visible color originates from the electronic transition within the I₅^- molecule, and any charge transfer between the I₅^- ion and either of α-CD or a coexisting counter cation is not involved. We also reveal that the electronic transitions of (I₅^-)_n are delocalized, which accounts for the well-known observation that the color of the iodine-starch reaction becomes bluish with an increase in the chain length of amylose. Furthermore, the preresonance Raman spectra calculated from the model suggest that the vibrational motions are localized in the I₅^- subunit dominantly. A comparison between an experimental absorption spectrum feature of the α-CD-iodine complex and the calculated ones of (I₅^-)_n ions with various n values suggests that (I₅^-)₄ polyiodide ions tend to be populated dominantly in the α-CD-iodine complex under aqueous conditions.

Phosphoric acid and phosphorylation levels are potential biomarkers indicating developmental competence of matured oocytes

We identified biomarkers for mice oocyte maturation in metaphase II in vivo and in situ using Raman spectroscopy.

Non-staining visualization of embryogenesis and energy metabolism in medaka fish eggs using near-infrared spectroscopy and imaging

The energy metabolism and embryogenesis of fertilized Japanese medaka eggs were investigated in vivo at the molecular level using near-infrared (NIR) spectroscopy and imaging. Changes in chemical components, such as proteins and lipids, in yolk sphere and embryonic body were studied over the course of embryonic development. Metabolic changes that represent variations in the concentrations and molecular compositions of proteins and lipids in the yolk part, particularly on the 1^st day after fertilization and the day just before hatching, were successfully identified in the 4900-4000 cm^-1 wavenumber region. The yolk components were shown to have specific functions at the very early and final stages of the embryonic development. Proteins with α-helix- or β-sheet-rich structures clearly showed the different variation patterns within the developing egg. Furthermore, the distribution of lipids could be selectively visualized using data from the higher wavenumber region. Detailed embryonic structures were clearly depicted in the NIR images using the data from the 6400-5500 cm^-1 region in which the embryo parts had some characteristic peaks due to unsaturated fatty acids. It was made clear that yolk and embryo parts had different components especially lipid components. The present study provides new insights into material variations in the fertilized egg during its growth. NIR imaging proved to be valuable in investigating the embryogenesis in vivo at the molecular level in terms of changes in biomolecular concentrations and compositions, metabolic differentiation, and detailed information about embryonic structures without the need for staining.

Noninvasive, high-speed, near-infrared imaging of the biomolecular distribution and molecular mechanism of embryonic development in fertilized fish eggs

In this study, the distribution of biomaterials and its molecular mechanism of embryonic development in Japanese medaka fish were analyzed nondestructively and noninvasively without staining using near-infrared (NIR) imaging. The microscopic NIR imaging system used in this research was a device capable of ultra-high-speed imaging; using this system, one can acquire microscopic imaging data in a few seconds. Therefore, the medaka eggs remained alive throughout measurements and were successfully monitored in vivo. The distributions of biomolecules were examined by mapping the intensities of NIR bands resulting from lipids, proteins and water in 2 dimensions (2D). The structures of eyes, lipid bilayer membranes, micelles and water-structure differences at the interface of different substances constituting different structures on the egg were visualized. Furthermore, insights on the metabolic mechanisms of lipids and membrane functions were drawn from the biased distribution of lipoproteins and the presence of unsaturated fatty acids in the egg membrane. These results indicated the potential for NIR imaging in evaluating the biological functions and metabolic systems of cells and embryos.

Spectra-structure correlations of saturated and unsaturated medium-chain fatty acids. Near-infrared and anharmonic DFT study of hexanoic acid and sorbic acid

Quantum chemical reproduction of entire NIR spectra is a new trend, enabled by contemporary advances in the anharmonic approaches. At the same time, recent increase of the importance of NIR spectroscopy of biological samples raises high demand for gaining deeper understanding of NIR spectra of biomolecules, i.e. fatty acids. In this work we investigate saturated and unsaturated medium-chain fatty acids, hexanoic acid and sorbic acid, in the near-infrared region. By employing fully anharmonic density functional theory (DFT) calculations we reproduce the experimental NIR spectra of these systems, including the highly specific spectral features corresponding to the dimerization of fatty acids. Broad range of concentration levels from 5·10^-4M in CCl₄ to pure samples are investigated. The major role of cyclic dimers can be evidenced for the vast majority of these samples. A highly specific NIR feature of fatty acids, the elevation of spectral baseline around 6500-4000cm^-1, is being explained by the contributions of combination bands resulting from the vibrations of hydrogen-bonded OH groups in the cyclic dimers. Based on the high agreement between the calculated and experimental NIR spectra, a detailed NIR band assignments are proposed for hexanoic acid and sorbic acid. Subsequently, the correlations between the structure and NIR spectra are elucidated, emphasizing the regions in which clear and universal traces of specific bands corresponding to saturated and unsaturated alkyl chains can be established, thus demonstrating the wavenumber regions highly valuable for structural identifications.

Unveiling the Aggregation of Lycopene in Vitro and in Vivo: UV-Vis, Resonance Raman, and Raman Imaging Studies

The present study investigates the structure of lycopene aggregates both in vitro and in vivo using ultraviolet-visible (UV-vis) and Raman spectroscopies. The electronic absorption bands of the J- and H-aggregates in vitro shift to lower and higher energies, respectively, compared to that of the lycopene monomer. Along with these results, the frequencies of the ν₁ Raman bands were shifted to lower and higher frequencies, respectively. By plotting the frequencies of the ν₁ Raman band against the S₀ → S₂ transition energy, a linear relationship between the data set with different aggregation conformations can be obtained. Therefore, the band positions depending on the different conformations can be explained based on the idea that the effective conjugated C═C chain lengths within lycopene molecules are different due to the environmental effect (site-shift effect) caused by the aggregation conformation. Applying this knowledge to the in vivo measurement of a tomato fruit sample, the relationship between the aggregation conformation of lycopene and the spectral patterns observed in the UV-vis as well as Raman spectra in different parts of tomato fruits was discussed in detail. The results showed that the concentration of lycopene (particularly that of the J-aggregate) specifically increased, whereas that of chlorophyll decreased, with ripening. Furthermore, Raman imaging indicated that lycopene with different aggregate conformations was distributed inhomogeneously, even within one sample. The layer formation in tomato tissues with high concentrations of J- and H-aggregates was successfully visualized. In this manner, the presence of lycopene distributions with different aggregate conformations was unveiled in vivo.

Critical Evaluation of NIR and ATR-IR Spectroscopic Quantifications of Rosmarinic Acid in Rosmarini folium Supported by Quantum Chemical Calculations

The present study evaluates the analytical performance of near infrared as well as attenuated total reflection infrared spectroscopy for the determination of the rosmarinic acid content in Rosmarini folium. Therefore, the recorded near infrared and attenuated total reflection infrared spectra of 42 milled Rosmarini folium samples were correlated with reference data (range: 1.138-2.199 rosmarinic acid %) obtained by HPLC analysis. Partial least squares regression models were established as a quantitative multivariate data analysis tool. Evaluation via full cross-validation and test set validation resulted in comparable performances for both techniques: near infrared [coefficient of determination: 0.90 (test set validation); standard error of cross-validation: 0.060 rosmarinic acid %; standard error of prediction: 0.058 rosmarinic acid %] and attenuated total reflection infrared [coefficient of determination: 0.91 (test set validation); standard error of cross-validation: 0.063 rosmarinic acid %; standard error of prediction: 0.060 rosmarinic acid %]. Furthermore, quantum chemical calculations were applied to obtain a theoretical infrared spectrum of rosmarinic acid. Good agreement to the spectrum of pure rosmarinic acid was achieved in the lower wavenumber region, whereas the higher wavenumber region showed less compliance. The knowledge of the vibrational modes of rosmarinic acid was used for the association with the high values of the regression coefficient plots of the established partial least squares regression models.

Comparison of multivariate analysis methods for extracting the paraffin component from the paraffin-embedded cancer tissue spectra for Raman imaging

This study aimed to extract the paraffin component from paraffin-embedded oral cancer tissue spectra using three multivariate analysis (MVA) methods; Independent Component Analysis (ICA), Partial Least Squares (PLS) and Independent Component - Partial Least Square (IC-PLS). The estimated paraffin components were used for removing the contribution of paraffin from the tissue spectra. These three methods were compared in terms of the efficiency of paraffin removal and the ability to retain the tissue information. It was found that ICA, PLS and IC-PLS could remove the paraffin component from the spectra at almost the same level while Principal Component Analysis (PCA) was incapable. In terms of retaining cancer tissue spectral integrity, effects of PLS and IC-PLS on the non-paraffin region were significantly less than that of ICA where cancer tissue spectral areas were deteriorated. The paraffin-removed spectra were used for constructing Raman images of oral cancer tissue and compared with Hematoxylin and Eosin (H&E) stained tissues for verification. This study has demonstrated the capability of Raman spectroscopy together with multivariate analysis methods as a diagnostic tool for the paraffin-embedded tissue section.

High-Speed Scanning for the Quantitative Evaluation of Glycogen Concentration in Bioethanol Feedstock Synechocystis sp. PCC6803 Using a Near-Infrared Hyperspectral Imaging System with a New Near-Infrared Spectral Camera

In the present study, the high-speed quantitative evaluation of glycogen concentration accumulated in bioethanol feedstock Synechocystis sp. PCC6803 was performed using a near-infrared (NIR) imaging system with a hyperspectral NIR spectral camera named Compovision. The NIR imaging system has a feature for high-speed and wide area monitoring and the two-dimensional scanning speed is almost 100 times faster than the general NIR imaging systems for the same pixel size. For the quantitative analysis of glycogen concentration, partial least squares regression (PLSR) and moving window PLSR (MWPLSR) were performed with the information of glycogen concentration measured by high performance liquid chromatography (HPLC) and the calibration curves for the concentration within the Synechocystis sp. PCC6803 cell were constructed. The results had high accuracy for the quantitative estimation of glycogen concentration as the best squared correlation coefficient R² was bigger than 0.99 and a root mean square error (RMSE) was less than 2.9%. The present results proved not only the potential for the applicability of NIR spectroscopy to the high-speed quantitative evaluation of glycogen concentration in the bioethanol feedstock but also the expansivity of the NIR imaging instrument to in-line or on-line product evaluation on a factory production line of bioethanol in the future.

Critical evaluation of spectral information of benchtop vs. portable near-infrared spectrometers: quantum chemistry and two-dimensional correlation spectroscopy for a better understanding of PLS regression models of the rosmarinic acid content in Rosmarini folium

In the present work the performances of one benchtop and two different types of miniaturized near-infrared (NIR)-spectrometers were tested and compared for the first time by the determination of the rosmarinic acid (RA) content of dried and powdered Rosmarini folium. The recorded NIR spectra were utilized in hyphenation with multivariate data analysis (MVA) to calculate Partial Least Squares (PLS) regression models. Quality parameters obtained from Cross Validation (CV) revealed that the benchtop NIR-device "NIRFlex N-500 FT-NIR spectrometer" achieved the best result with a R2 of 0.91 and a RPD of 3.27. The miniaturized NIR-device "MicroNIR 2200 spectrometer" showed a satisfying calibration quality with a R2 of 0.84 and a RPD of 2.46. The miniaturized NIR-device "ThermoScientific microPHAZIR" with a R2 of 0.73 and a RPD of 1.88 was less precise and needs to be improved. The measured spectra of the different devices were additionally investigated by two-dimensional correlation spectroscopy (2D-COS) analysis, which supported the performed PLS regression models as well as identified the discrepancies for microPHAZIR and MicroNIR 2200 compared to NIRFlex N-500. With the aim to obtain a better understanding of the factors which determine the analyzed PLS regression models, the NIR spectrum of RA was reproduced through application of fully anharmonic quantum chemical calculation. A good agreement between the experimental and theoretical NIR spectra and detailed band assignments of RA were obtained in the 8000-4000 cm-1 wavenumber region. Subsequently, this enabled us to attribute the main influences in the regression coefficients plots. This study demonstrated that the performance of NIR spectroscopy with benchtop and miniaturized devices as a fast and non-invasive technique is able to replace time- and resource-consuming analytical tools. Referring to the developed application of the RA content quantification this work is especially interesting for the continuous growing phytopharmaceutical industry and its quality control. The results reveal the importance of monitoring the performances of available NIR-spectrometers in every analytical area.

Diagnosis of early-stage esophageal cancer by Raman spectroscopy and chemometric techniques

Esophageal cancer is a disease with high mortality. In order to improve the 5 year survival rate after cancer treatment, it is important to develop a method for early detection of the cancer and for therapy support. There is increasing evidence that Raman spectroscopy, in combination with chemometric analysis, is a powerful technique for discriminating pre-cancerous and cancerous biochemical changes. In the present study, we used Raman spectroscopy to examine early-stage (stages 0 and I) esophageal cancer samples ex vivo. Comparison between the Raman spectra of cancerous and normal samples using a t-test showed decreased concentrations of glycogen, collagen, and tryptophan in cancerous tissue. Partial least squares regression (PLSR) analysis and self-organization maps (SOMs) discriminated the datasets of cancerous and normal samples into two groups, but there was a relatively large overlap between them. Linear discriminant analysis (LDA) based on Raman bands found in the t-test was able to predict the tissue types with 81.0% sensitivity and 94.0% specificity.

Imaging of Hydrophilicity and its Inhomogeneity on a Titanium Dioxide Film Exposed to Ultraviolet Irradiation Using a Newly Developed Near-Infrared Camera

This study has investigated hydrophilicity changes and their inhomogeneity of TiO2 films on Pyrex glasses by near-infrared (NIR) spectral imaging. Near-infrared spectra of TiO2 films in the 9000-4000 cm(-1) region were measured using a newly developed NIR camera named Compovision. A band in the 5400-4800 cm(-1) region, which is assigned to a combination (ν2 + ν3) mode of bending (ν2) and antisymmetric stretching (ν3) modes of the H2O molecule, was clearly identified and its intensity increased with time in the air. It is interesting that the increased rate rose with ultraviolet (UV) light irradiation (300-400 nm, 1 mW cm(-2)) compared to without UV light irradiation. This result suggested that the hydrophilicity of TiO2 was enhanced about twice upon the UV light irradiation. Moreover, the NIR images clarified spatial distributions of the hydrophilicity on the TiO2 surface with a significantly wide area (20 × 40 mm) and a high speed (within 5 s for one image). This rapid imaging system enabled us to detect the hydrophilicity change during only 1 min. The potential of this camera is quite superior, not only for basic research, but also for diverse industrial applications.

Raman endoscopy for the in situ investigation of advancing colorectal tumors in live model mice

The aim of the present study is to evaluate the capability of a miniaturized Raman endoscope (mRE) system to monitor the advancement of colorectal tumors in model mice as a method that is noninvasive to the tumor itself. Nevertheless, the endoscope is narrow enough to observe the inside of the mouse colon in such a way that is semi-noninvasive to the animal. However, the mRE system allowed the visualization and Raman spectral measurement of any targeted point within the colorectal tumor in model mice under anesthesia, without damaging the tissue (i.e., noninvasively). Continuous monitoring of the same tumor allowed the observation of alterations in its molecular composition and size, along with its advancement. The tumor lesion was discriminated from normal tissues of the control mouse with an accuracy of 86.8%. We succeeded in visualizing and performing Raman spectral observations on a shrinking polyp type tumor. The Raman analysis suggested that it was not cured but supposedly transformed to another tumor type.

Spontaneous remission of epstein-barr virus-positive diffuse large B-cell lymphoma of the elderly

A 94-year-old female patient presented with anorexia and left axillar lymphadenopathy on admission. Her past history was angina pectoris at 83 years of age and total gastrectomy due to gastric cancer at 87 years. The family history revealed that her son had had a malignant lymphoma, the histopathological diagnosis of which was diffuse large B-cell lymphoma. A physical examination showed both cervical, axillar, and inguinal lymphadenopathy without tenderness. She had elevated lactate dehydrogenase, ferritin, and soluble interleukin-2 receptor (sIL-2R). Whole-body computed tomography confirmed the cervical, axillary, and inguinal lymphadenopathy. Gallium-68 imaging revealed positive accumulation in these superficial lymph nodes. A right inguinal lymph node biopsy showed features of Epstein-Barr virus-associated lymphoproliferative disorder. Immunohistological studies on this lymph node biopsy showed CD20-positive large cells, CD3-positive small cells, and CD30-partly-positive large cells. In situ hybridization showed Epstein-Barr virus-positive, LMP-partly-positive, and EBNA2-negative cells. She refused chemotherapy as her son had died from hematemesis during chemotherapy. She received intravenous hyperalimentation for 1 month after admission. No palpable lymph nodes were identified by physical examination or computed tomography 3 months after admission, and regression of lactate dehydrogenase, ferritin, and sIL-2R was observed. She recovered from anorexia and was discharged. She died from pneumonia 10 months later after initial symptoms of anorexia. The autopsy showed no superficial lymphadenopathy.

Inducible nitric oxide synthase expression and nuclear factor-kappaB activation in alveolar type II cells in lung injury

Alveolar type II cells (type II cells) play a crucial role in the progression and repair of lung inflammation and injury. We investigated whether inducible nitric oxide synthase (iNOS) was expressed and nuclear factor-kappaB (NF-kappaB) was activated in type II cells in lung injury. After injecting lipopolysaccharide (LPS) or saline in the rat, the lungs were excised and type II cells were isolated. iNOS and its mRNA were expressed both in lung tissue and isolated type II cells in response to LPS. The lungs from saline-treated rats showed only minimal expression of iNOS. Electrophoretic mobility shift assay revealed that expression of NF-kappaB in the nuclear extracts was augmented by LPS, and p5O/NFkappaB was expressed in type II cells in LPS-treated rats. Intraperitoneal dexamethasone almost completely inhibited the iNOS expression and attenuated the activation of NF-kappaB in the LPS-treated lung. These findings suggest that type II cells can be a source of NO production in lung injury,and that the effects of corticosteroids may be in part through inhibition of both iNOS expression and NF-kappaB activation.

Beta1-adrenoceptor stimulation by high-dose terbutaline downregulates terbutaline-stimulated alveolar fluid clearance in ex vivo rat lung

Because high-dose terbutaline and isoproterenol (10(-3) M), beta2-adrenergic agonists, failed to increase alveolar fluid clearance, the mechanisms responsible for this effect were examined in ex vivo rat lungs. An isosmolar 5% albumin solution with Evans blue dye was instilled into the distal airspaces in isolated rat lungs that were then inflated with 100% oxygen at an airway pressure of 8 cm H2O in a 37 degrees C incubator. Alveolar fluid clearance was measured by the progressive increase in dye concentrations over 1 hour. The results indicated that: (1) although 10(-5) M terbutaline or isoproterenol increased alveolar fluid clearance, 10(-3) M terbutaline or isoproterenol did not; (2) both concentrations of terbutaline (10(-5), 10(-3) M) increased intracellular adenosine 3',5'-cyclic monophosphate in cultured type II alveolar epithelial cells; (3) instillation of atenolol, a selective beta1-adrenergic antagonist, in the presence of either 10(-3) M terbutaline or isoproterenol was associated with an increase in alveolar fluid clearance. These results suggested that beta1-adrenoceptor stimulation prevented the normal response to a beta2-adrenergic agonist. To further test this hypothesis, a selective beta1-adrenergic agonist, denopamine, was administered; these results showed that (4) 10(-3) M denopamine, a selective beta1-adrenergic agonist, inhibited the increase in alveolar fluid clearance in the presence of 10(-5) M terbutaline; (5) hypoxia for 2 hours did not alter the effects of terbutaline on alveolar fluid clearance. The mechanism for the inability of the alveolar epithelium to respond to high-dose terbutaline or isoproterenol with the normal upregulation of alveolar fluid clearance in ex vivo rats lungs appears to be mediated by beta1-adrenoceptor stimulation that subsequently suppresses the beta2-adrenergic response.

Denopamine, a beta(1)-adrenergic agonist, increases alveolar fluid clearance in ex vivo rat and guinea pig lungs

The effect of denopamine, a selective beta(1)-adrenergic agonist, on alveolar fluid clearance was determined in both ex vivo rat and guinea pig lungs. Alveolar fluid clearance was measured by the progressive increase in the concentration of Evans blue-labeled albumin over 1 h at 37 degrees C. Denopamine (10(-6) to 10(-3) M) increased alveolar fluid clearance in a dose-dependent manner in ex vivo rat lungs. Denopamine also stimulated alveolar fluid clearance in guinea pig lungs. Atenolol, a selective beta(1)-adrenergic antagonist, and amiloride, a sodium channel inhibitor, inhibited denopamine-stimulated alveolar fluid clearance. The potency of denopamine was similar to that of similar doses of isoproterenol or terbutaline. Short-term hypoxia (100% nitrogen for 1-2 h) did not alter the stimulatory effect of denopamine. Denopamine (10(-4), 10(-3) M) increased intracellular adenosine 3',5'-cyclic monophosphate levels in cultured rat alveolar type II cells. In summary, denopamine, a selective beta(1)-adrenergic agonist, stimulates alveolar fluid clearance in both ex vivo rat and guinea pig lungs.

Lung deflation impairs alveolar epithelial fluid transport in ischemic rabbit and rat lungs

BACKGROUND

Because the fluid transport capacity of the alveolar epithelium after lung ischemia with and without lung deflation has not been well studied, we carried out experimental studies to determine the effect of lung deflation on alveolar fluid clearance.

METHODS

After 1 or 2 hr of ischemia, we measured alveolar fluid clearance using 125I-albumin and Evans blue-labeled albumin concentrations in in vivo rabbit lungs in the presence of pulmonary blood flow and in ex vivo rat lungs in the absence of any pulmonary perfusion, respectively.

RESULTS

The principal results were: (1) lung deflation decreased alveolar fluid clearance while inflation of the lungs during ischemia preserved alveolar fluid clearance in both in vivo and ex vivo studies; (2) alveolar fluid clearance was normal in the rat lungs inflated with nitrogen (thus, alveolar gas composition did not affect alveolar fluid clearance); (3) amiloride-dependent alveolar fluid clearance was preserved when the lungs were inflated during ischemia; (4) terbutaline-simulated alveolar fluid clearance was preserved in the hypoxic rat lungs inflated with nitrogen; (5) lecithinized superoxide dismutase, a scavenger of superoxide anion, and N(omega)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide, preserved normal alveolar fluid clearance in the deflated rat lungs.

CONCLUSION

Lung deflation decreases alveolar fluid clearance by superoxide anion- and nitric oxide-dependent mechanisms.

Variations in the gene for vacuolating toxin, vacA, in Japanese isolates of Helicobacter pylori

Each of 284 strains of Helicobacter pylori which had been isolated in Japan was shown, by use of the polymerase chain reaction (PCR), to be positive for the vacA genes. The amplified vacA genes generated by PCR were classified into six classes (five for the clinical isolates, and one which corresponded to the standard strains). Endoscopic analysis revealed that cases of gastritis were most likely to be associated with class D, while none were associated with class A. The patterns of products of PCR obtained from the Japanese isolates were compared with theoretical patterns derived from sequences of vacA which had been reported previously. The nucleotide sequences of amplified fragments of vacA from representative strains in each class were determined and compared with those of previously reported vacA genes.

Retrograde intra-arterial infusion of prostaglandin E1 and heparin for the no-reflow phenomenon after oromandibular reconstruction with a free fibular flap

The authors encountered a patient with a tumor of the floor of the mouth in whom the no-reflow phenomenon occurred after excision of the lesion and the mandible, followed by reconstruction using a free fibular flap. A catheter was inserted retrogradely from the point where the peroneal artery had been ligated at the time of flap preparation. Continuous intra-arterial infusion of prostaglandin E1 and heparin was performed, and the flap survived. This method salvaged free flaps subject to the no-reflow phenomenon.

[Pulmonary metastatic malignant phyllodes tumor showing multiple thin walled cavities]

A 52-year-old woman who had undergone a partial mastectomy 1 year earlier because of benign phyllodes tumor was admitted because of dry cough and abnormal chest radiograph findings. Chest computed tomograms demonstrated multiple thin-walled cavities and nodules. Clinical examinations and transbronchial biopsy specimens failed to provide a conclusive diagnosis. However, the pulmonary thin-walled cavities enlarged, and a nodular shadow revealed cavitary formation. An open lung biopsy was performed to diagnose the pulmonary lesions. Although biopsy specimens disclosed the infiltration of poorly differentiated adenocarcinoma cells in pleura and pulmonary parenchyma, no primary site was detected. The patient did not respond to systemic chemotherapy (CDDP and VP-16), and died of respiratory failure due to advanced pulmonary metastasis. Autopsy demonstrated marked tumor invasion of the lungs, myocardium, and bone. We analyzed malignant cells in lung tissues at autopsy by immunohistochemistry, and found identical malignant cells in surgical samples obtained during the patients earlier mastectomy. A diagnosis of pulmonary metastasis from malignant phyllodes tumor of the breast was made. Thin walled cavitary lesions from malignant phyllodes tumor are rare; however, pulmonary metastasis of malignant phyllodes tumor should be considered one disease that exhibits thin-walled cavities as a radiographic manifestation.

Effect of hypoxia on pulmonary blood flow-segmental vascular resistance relationship in perfused cat lungs

To investigate the effect of alveolar hypoxia on the pulmonary blood flow-segmental vascular resistance relationship, we determined the longitudinal distribution of vascular resistance while increasing blood flow during hyperoxia or hypoxia in perfused cat lungs. We measured microvascular pressures by the micropipette servo-null method, partitioned the pulmonary vessels into three segments [i.e., arterial (from main pulmonary artery to 30- to 50-micron arterioles), venous (from 30- to 50-micron venules to left atrium), and microvascular (between arterioles and venules) segments] and calculated segmental vascular resistance. During hyperoxia, total resistance decreased with increased blood flow because of a reduction of microvascular resistance. In contrast, during hypoxia, not only microvascular resistance but also arterial resistance decreased with increase of blood flow while venous resistance remained unchanged. The reduction of arterial resistance was presumably caused by arterial distension induced by an elevated arterial pressure during hypoxia. We conclude that, during hypoxia, both microvessels and arteries >50 micron in diameter play a role in preventing further increases in total pulmonary vascular resistance with increased blood flow.

[Analysis of mutations and heteroplasmy at mitochondrial DNA 11778 using non-RI single strand conformation polymorphisms in Leber's hereditary optic neuropathy]

Leber's hereditary optic neuropathy(LHON) is a maternally inherited mitochondrial disease of an acute or subacute bilateral loss of central vision. G to A substitutions at nucleotide position 11778 in mitochondrial DNA(mt DNA) have been identified in approximately 40% to 90% of patients. In this study, regions containing mt DNA 11778 mutations were analyzed by polymerase chain reaction(PCR), non-RI single strand conformation polymorphisms(SSCP) and direct sequencing. In 26 visually affected patients, mt DNA 11778 mutations were detected in 9 patients (36.4%). In one pedigree of a LHON patient(L-6), four unaffected family members had heteroplasmy of the 11778 mutation using non-RI SSCP. Ratios of the heteroplasmy between wild type and mutant mt DNAs can be detected in non-RI SSCP and accurately quantified by video densitometric analyzer. Two types of novel polymorphisms, 11696 G to A and 11719 A to G, in the mt DNA region were also found in this non-RI SSCP analysis. Non-RI SSCP is an efficient and accurate method for diagnosis of mt DNA 11778 mutations and quantifying heteroplasmy in patients with LHON and pedigrees.

Lung microvascular pressure profile in acute lung injury

To clarify the role of microvessels in the development of pulmonary hypertension of acute lung injury, we induced lung edema by oleic acid (OA) in ten artificially perfused cat lungs and measured microvascular pressure. Pulmonary artery pressure (Ppa) and pressure of 30-50 microns arteriole (Parteriole) increased from 19.2 +/- 1.4 and 15.7 +/- 1.0 cmH2O before to 30.5 +/- 5.0 cmH2O and 22.7 +/- 2.4 cmH2O after edema, respectively. Pressure of 30-50 microns venule (Pvenule) and venous occlusion pressure (Pvo) did not change significantly after edema. Double occlusion pressure (Pdo) which represents pulmonary microvascular pressure increased from 14.5 +/- 0.6 to 17.7 +/- 2.0 cmH2O. Pressure gradient in the artery, i.e., between Ppa and Parteriole and in the microvessels, i.e., between Parteriole and Pvenule increased when lung became edematous. Pressure gradient in vein, i.e., between Pvenule to left atrium was not affected by edema. Pdo was in the midst of Parteriole and Pvenule in both edematous and non-edematous lung. In acute lung injury, increase of microvascular resistance was followed by an increase of arterial resistance and caused pulmonary hypertension.

[Nucleotide sequences at intron 6 and exon 7 junction of fibroblast growth factor receptor 2 and rapid mutational analysis in Apert syndrome]

Apert syndrome, acrocephalosyndactyly Type I, is an autosomal dominant craniosynostosis comprising acrocephaly, facial dysmorphism and severe syndactyly of the hands and feet. Missense mutations at codons 252 and 253 at 5'-end on exon 7 of fibroblast growth factor receptor (FGFR) 2 have been identified in a large number of patients with Apert syndrome. In this study, nucleotide sequences on the intron 6 were determined by vector ligation-PCR and direct sequencing. Five DNA samples from sporadic Apert syndrome were examined by non-RI SSCP and direct sequencing using a primer pair of intron 6 and exon 7. All cases of the syndrome showed abnormal banding pattern in the SSCP and missense mutations from Ser to Trp at codon 252 of the FGFR2 gene. The non-RI SSCP and direct sequencing of the FGFR2 exon 7 from genomic DNAs may be a useful and rapid molecular means for clinical diagnosis of Apert syndrome.

[Frequent missense mutations of fibroblast growth factor receptor (FGFR) gene families in craniofacial syndromes in Japanese patients]

Craniofacial syndromes, including Crouzon syndrome, Pfeiffer syndrome, Jackson-Weiss syndrome, Apert syndrome and achondroplasia, have been indicated that syndromes were associated with mutations of fibroblast growth factor receptor (FGFR) gene families. In this report, seven Japanese patients with craniofacial syndromes, three Crouzon syndromes and four achondroplasias, were analyzed on FGFR2 and FGFR3 genes by non RI-SSCP (single strand conformation polymorphisms) and direct sequencing. Missense mutations of the FGFR3 exon 10, at codon 380 in two sporadic cases and codon 375 in two familial cases, were detected in all cases of achondroplasia. Mutations of the FGFR2 were noted in Crouzon and Apert syndromes. One of three Crouzon syndromes has a missense mutation at codon 342 on exon 9. Highly frequent mutations were clustered within some localized regions of the FGFR genes in craniofacial syndromes. Alterations in these receptors due to missense mutations would thus appear closely involved in pathogenesis of craniofacial syndrome. The non RI-SSCP and direct sequencing of the FGFR genes, shown in this report, may be an appropriate approach for diagnosis of these syndromes with extensive clinical application.

[Effect of endogenous and inhaled nitric oxide on pulmonary microcirculation]

The sites of action of endogenous and inhaled nitric oxide (NO) were reassured during hypoxic pulmonary vasoconstriction. Lungs of 21 adult cats were perfused in situ with autologous blood in zone-3 conditions. Capillary pressures were measured by the double-occlusion techniques and pressures in arterioles and venules 70-100 microns in diameter were measured by the servo-null micropuncture technique, both during normoxia (FiO2 = 0.3) and during hypoxia (FiO2 = 0.02). The effects of NG-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg), an inhibitor of NO synthase, and of inhaled NO (5-100 ppm) were also measured. The PO2 of the prefusate decreased from 187.6 +/- 5.3 mmHg during normoxia to 25.7 +/- 1.3 mmHg during hypoxia, and further decreased to 20.8 +/- 2.2 mmHg during hypoxia with 50 ppm NO (p < 0.05, compared with hypoxia only). Increases in pulmonary vascular pressure drop in response to hypoxia were 4.8 +/- 1.0 cmH2O and 9.1 +/- 1.4 cmH2O in non-treated and L-NAME-treated lungs, respectively (p < 0.05). L-NAME significantly increased hypoxic construction in the venous segment. The concentration of exhaled NO increased from 13 +/- 4 ppb during normoxia to 18 +/- 4 ppb during hypoxia (p < 0.1). Inhaled NO lowered not only pulmonary artery pressure but also capillary pressure in a dose-dependent manner, which reduced hypoxic pulmonary vasoconstriction. Pulmonary veins were more sensitive to inhaled NO than were arteries. Inhaled NO (50 ppm) dilated vessels smaller than 70 to 100 microns in diameter, by 39% (p < 0.05), and dilated venules greater than 100 microns in diameter by 26% (p < 0.05), but did not significantly dilate arterioles greater than 100 microns in diameter (11%). Inhaled NO did not significantly change the ratio of wet weight to dry weight. We conclude that both endogenous and inhaled NO attenuate hypoxic pulmonary vasoconstriction, with significant pulmonary venous dilation. The main site of action of inhaled NO is vessels smaller than 100 microns in diameter and venules greater than 100 microns in diameter. Inhaled NO (5-100 ppm) does not cause interstitial edema.

[Intracellular Ca2+ response induced by acetylcholine in the submucosal nasal gland acinar cells of guinea pigs]

We examined intracellular Ca2+ responses of nasal gland acinar cells in order to clarify cellular responses and molecular events with regard to the regulatory mechanism of nasal secretion. The acinar cells of the serous gland, in the guinea-pig nasal septum, were obtained by meticulous and selective dissection with minimal contamination of epithelial lining cells followed by collagenase treatment. The dispersed acini were incubated in an oxygenated solution supplemented with fura -2 acetoxymethyl ester and the intracellular Ca2+ concentration ([Ca2+]i) was measured using fluorescence ratio imaging microscopy. The application of acetylcholine (ACh) to the nasal gland acinar cells induced an initially rapid increase in [Ca2+]i followed by a sustained plateau. The increase in [Ca2+]i induced by ACh was concentration-dependent and ranged from 10(-8) to 10(-5) M. The intracellular Ca2+ response was completely inhibited by atropine, indicating the presence of muscarinic cholinergic receptors. Removal of external Ca2+ with addition of EGTA resulted in a transient increase without a sustained phase. The sustained phase of the [Ca2+]i increase induced by ACh was inhibited by Ni2+, but not by nifedipine. The initial phase seems to be due to mobilization from cytosolic Ca2+ stores while the subsequent sustained phase is dependent on the influx of external Ca2+ ions sensitive to Ni2+. We have demonstrated that increasing the Ca2+ gradient by elevating external Ca2+ accelerates Ca2+ entry, and that depolarization of cells due to elevated external K+ attenuates Ca2+ entry. These findings suggest that the Ca2+ entry process in nasal gland acinar cells is dependent on the electrochemical gradient across the membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Na+ transport processes in isolated guinea pig nasal gland acinar cells

In the dispersed acinar cells of the submucosal nasal gland in the guinea pig, intracellular Na+ concentration ([Na+]i) was measured with a microfluorimetric imaging method and the cytosolic indicator dye, sodium-binding benzofuran isophthalate, under HCO3(-)-free conditions. In the unstimulated condition, the [Na+]i was averaged to 12.8 +/- 5.2 mM. Addition of 100 microM ouabain or removal of external K+ caused an increase in [Na+]i. Replacement of external Cl- with NO3- or addition of 0.5 mM furosemide reversibly decreased the [Na+]i. The recovery process from the reduced [Na+]i was inhibited by removal of either K+ or Cl- in the bath solution. These findings indicate the presence of a continuous influx of Na+ coupled with K+ and Cl- movement. Application of acetylcholine (ACh, 1 microM) caused an increase in [Na+]i by about 15-20 mM, which was completely inhibited by addition of 10 microM atropine. Increased cytosolic Na+ induced by ACh was extruded by the Na(+)-K+ pump. Removal of external Cl- and addition of 50 microM dimethylamiloride inhibited ACh-induced increase in [Na+]i by about 66% and 19%, respectively. In both unstimulated and stimulated state, Na(+)-K+ pump, Na-K-Cl cotransport, and Na(+)-H+ exchange play a critical role in maintaining intracellular electrolyte environment and in controlling a continuous secretion of nasal fluids.

Intracellular Ca2+ responses induced by acetylcholine in the submucosal nasal gland acinar cells in guinea pigs

We examined intracellular Ca2+ responses of the nasal gland acinar cells to clarify cellular responses and molecular events with regard to the regulatory mechanism of the nasal secretion. The acinar cells of the serous gland in the nasal septum of guinea pigs were obtained by meticulous and selective dissection with minimal contamination by epithelial lining cells after collagenase treatment. The dispersed acini were incubated in the oxygenated solution supplemented with fura 2 acetoxymethyl ester, and the intracellular Ca2+ concentration ([Ca2+]i) was measured by fluorescence ratio imaging microscopy. The application of acetylcholine (ACh) to the cells induced an initially rapid increased [Ca2+]i followed by a sustained plateau. The increase in [Ca2+]i induced by ACh was concentration dependent, ranging between 10(-8) and 10(-4) M. The [Ca2+]i response was completely inhibited by atropine, further indicating the involvement of muscarinic cholinergic receptors. Removal of external Ca2+ with addition of EGTA resulted in a transient increase without a sustained phase, and the transient increase was abolished by the intracellular Ca2+ antagonist 8-(diethylamino)-octyl-3,4,5-trimethoxybenzoate, indicating that this increase in [Ca2+]i was due to release from internal stores. The initial peak was not altered by changes in external pH, addition of adenosine 3',5'-cyclic monophosphate (cAMP), nor addition of phorbol 12-myristate 13-acetate (PMA) but was augmented by external K(+)-induced depolarization, suggesting that the transient increase was due to a changing in the binding affinity to inositol 1,4,5-trisphosphate. The sustained Ca2+ entry induced by ACh was inhibited by Ni2+, but not by nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of pulmonary blood flow on microvascular pressure profile determined by micropuncture in perfused cat lungs

To clarify the role of the pulmonary microvasculature in adjusting to increased pulmonary blood flow, we measured arteriolar and venular pressure by the servo-null micropuncture method while changing the pulmonary blood flow in isolated perfused cat lungs. We divided the lung vasculature into three longitudinal segments: 1) arterial (pulmonary artery to 30- to 50-microns arteriole), 2) microvascular (between 30- to 50-microns arteriole and venule), and 3) venous (30- to 50-microns venule to left atrium). The vascular resistance was calculated by dividing the pressure gradient by the flow. The pressure gradient of the microvascular segment did not increase, whereas the pressure gradient of the arterial and venous segments increased simultaneously with flow rate. Total and microvascular resistance decreased with increase of flow rate. Resistances of the arterial and venous segments did not change with increase in flow. We conclude that the microvasculature plays a crucial role in preventing pulmonary hypertension with increases in flow by decreasing microvascular resistance.

Ionic currents evoked by acetylcholine in isolated acinar cells of the guinea pig nasal gland

The patch-clamp whole cell recording was used to demonstrate activation of membrane conductance to K+, Cl- and cations induced by acetylcholine (ACh) in the isolated acinar cells of the guinea pig nasal gland. A small outward K+ current at 0 mV and a large transient and sustained inward current at -90 mV were evoked by ACh and ACh-evoked reversal potential was about -3 mV nearly to Cl- equilibrium potential in 140 mM KCl in the pipette and physiological saline in the bath. The ionic substitutional experiments indicated that ACh-evoked inward currents were carried by both Cl- and cations. Both outward and inward currents evoked by ACh were almost completely abolished by removal of external Ca2+ and mimicked those evoked by a calcium ionophore A23187. These findings indicate that ACh-evoked membrane conductances are mediated by an increase in intracellular Ca2+.