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In the field of respiratory clinical practice, the importance of measuring carbon dioxide (CO2) concentrations cannot be overemphasized. Within the body, assessment of the arterial partial pressure of CO2 (PaCO2) has been the gold standard for many decades. Non-invasive assessments are usually predicated on the measurement of CO2 concentrations in the air, usually using an infrared analyzer, and these data are clearly important regarding climate changes as well as regulations of air quality in buildings to ascertain adequate ventilation. Measurements of CO2 production with oxygen consumption yield important indices such as the respiratory quotient and estimates of energy expenditure, which may be used for further investigation in the various fields of metabolism, obesity, sleep disorders, and lifestyle-related issues. Measures of PaCO2 are nowadays performed using the Severinghaus electrode in arterial blood or in arterialized capillary blood, while the same electrode system has been modified to enable relatively accurate non-invasive monitoring of the transcutaneous partial pressure of CO2 (PtcCO2). PtcCO2 monitoring during sleep can be helpful for evaluating sleep apnea syndrome, particularly in children. End-tidal PCO2 is inferior to PtcCO2 as far as accuracy, but it provides breath-by-breath estimates of respiratory gas exchange, while PtcCO2 reflects temporal trends in alveolar ventilation. The frequency of monitoring end-tidal PCO2 has markedly increased in light of its multiple applications (e.g., verify endotracheal intubation, anesthesia or mechanical ventilation, exercise testing, respiratory patterning during sleep, etc.).

Obstructive sleep apnea (OSA) patients are at risk for increased blood pressure and carotid intima-media thickness (IMT), with pulmonary hypertension and right-sided heart failure potentially developing as well. Chronic intermittent hypoxia (IH) has been used as an OSA model in animals, but its effects on vascular beds have not been evaluated using objective unbiased tools. Previously published and current experimental data in mice exposed to IH were evaluated for IMT in aorta and pulmonary artery (PA) after IH with or without normoxic recovery using software for meta-analysis, Review Manager 5. Because IMT data reports on PA were extremely scarce, atherosclerotic area percentage from lumen data was also evaluated. IH significantly increased IMT parameters in both aorta and PA as illustrated by Forest plots (P < 0.01), which also confirmed that IMT values after normoxic recovery were within the normal range in both vascular beds. One-sided scarce lower areas in Funnel Plots were seen for both aorta and PA indicating the likelihood of significant publication bias. Forest and Funnel plots, which provide unbiased assessments of published and current data, suggest that IH exposures may induce IMT thickening that may be reversed by normoxic recovery in both aorta and PA. In light of the potential likelihood of publication bias, future studies are needed to confirm or refute the findings. In conclusion, OSA may induce IMT thickening (e.g., aorta and/or PA), but the treatment (e.g., nasal continuous positive airway pressure) will likely lead to improvements in such findings.

ATP-sensitive potassium (KATP) channels consist of two structurally different subunits: a pore-forming subunit of the Kir6.0-family (Kir6.1 or Kir6.2) and a regulatory sulfonylurea receptor subunit (SUR1, SUR2A or SUR2B). Although Kir6.2 is widely distributed in the brain, the mechanisms that underlie the impact of Kir6.2 on emotional behavior are not yet fully understood. To clarify the role of Kir6.2 in emotional behavior, in the present study, we investigated the behavioral characteristics of Kir6.2-knockout (Kir6.2-/-) mice. Kir6.2-/- mice showed impaired general behavior in a locomotor activity test and open field test. In addition, anxiety-like behavior was observed in the open field test, elevated plus-maze test and light-dark test. In particular, excessive anxiety-like behavior was observed in female Kir6.2-/- mice. Moreover, we investigated whether Kir6.2 is expressed on monoamine neurons in the brain. Immunohistochemical studies showed that Kir6.2 was co-localized with tryptophan hydroxylase (TPH), a marker of serotonergic neurons, in dorsal raphe nuclei. Kir6.2 was also co-localized with tyrosine hydroxylase (TH), a marker of dopaminergic/noradrenergic neurons, in the ventral tegmental area and locus coeruleus. Next, we checked the protein levels of TH and TPH in the midbrain. Interestingly, TPH expression was significantly elevated in female Kir6.2-/- mice. These results suggest that Kir6.2 in monoamine neurons, especially serotonergic neurons, could play a key role in emotional behavior.

IntroductionThe rapid spread of COVID-19 posed a global burden. Substantial number of people died of the disease in the acute phase of infection. In addition, a significant proportion of patients have been reported to suffer from post-acute phase symptoms, sequelae of COVID-19, which may negatively influence the quality of daily living and/or socioeconomic circumstances of the patients. However, no previous study has comprehensively and objectively assessed the quality of life of patients by using existing international scales. Further, evidence of socioeconomic consequences among patients with COVID-19 is scarce. To address the multidimensional issues from sequelae of COVID-19, evidence from comprehensive surveys beyond clinical perspectives is critical that investigates health, and social determinants of disease progression as well as socioeconomic consequences at a large scale.Methods and analysisIn this study, we plan to conduct a nationwide and comprehensive survey for the sequelae of COVID-19 in a total of 1000 patients diagnosed at 27 hospitals throughout Japan. This study will evaluate not only the health-related status of patients from clinical perspectives but also the Health-related Quality of Life (HRQoL) scores, socioeconomic status and consequences to discuss the sequelae of the disease and the related risk factors. The primary endpoint is the frequency of long-term complications of COVID-19 infection. The secondary endpoints are risk factors for progression to sequelae of COVID-19 infection. The study will provide robust and important evidence as a resource to tackle the issues from the sequelae of COVID-19 from the multi-dimensional perspectives.Ethics and disseminationThis trial was approved by the Keio University School of Medicine Ethics Committee (20200243, UMIN000042299). The results of this study will be reported at a society meeting or published in a peer-reviewed journal.

Although the incidence of postbulbar duodenal ulcers is low, many complications occur, such as hemorrhage, stenosis and perforation, and there are many points to be paid attention to with regard to its pathology. A high acid level has been pointed out as a cause, but this is not conclusive, and its association with Helicobacter pylori (Hp) infection is also unclear. We investigated chronic cases excluding acute cases such as acute duodenal mucosal lesion we encountered between 2001 and 2015. Five cases corresponded, accounting for 1.4% of all chronic duodenal ulcer cases, and there were more male patients (four patients were male), as previously reported. All cases were solitary punched-out ulcer on the medial side near the superior duodenal flexure, and many complications were observed such as melena in all patients, narrowing in 2, and penetration in 1. No specific pathology, such as Crohn’s disease, vasculitis, or Zollinger-Ellison syndrome, was noted, no patient was previously medicated with NSAIDs or low dose aspirin, and 3 patients were infected with Hp. All cases were healed by proton pump inhibitor administration or gastric acid secretion-suppressing treatment with selective proximal vagotomy. Recurrence after Hp eradication occurred in all of the 3 Hp-infected patients, suggesting that involvement of Hp in the cause of disease is unlikely.

Background and objective Body weight of patients with obstructive sleep apnea after initiation of nasal continuous positive airway pressure appears to increase. We hypothesized that intermittent hypoxia (IH) will decrease energy expenditure (EE), and that normoxic recovery will lead to body weight gains. Methods C57BL/6 J male mice were exposed to either 12 h/day of mild IH (alternating FIO2-10-11% and 21%; 640 s cycle), or severe IH (FIO2-6-7%-21%; 180 s cycle) or sham IH daily for 4 or 8 weeks. After exposures, EE was evaluated while mice were kept under normoxia for 5 weeks and organ histology was evaluated. Results EE was not decreased by IH. However, visceral white adipocyte size after normoxic recovery was significantly increased in severe IH in an intensity-dependent manner. Conclusion Our hypothesis that IH would decrease EE was not corroborated. However, IH and normoxic recovery seem to promote severity-dependent enlargement of visceral adipocytes, likely reflecting altered energy preservation mechanisms induced by IH.

BackgroundUsual clinical practice for arterial blood gas analysis (BGA) in conscious patients involves a one-time arterial puncture to be performed after a resting period of 20–30 min. The aim of this study was to evaluate the use of transcutaneous BGA for estimating this gold standard arterial BGA.MethodsSpontaneously breathing Asian adults (healthy volunteers and respiratory patients) were enrolled (n = 295). Transcutaneous PO2(PtcO2) and PCO2(PtcCO2) were monitored using a transcutaneous monitor (TCM4, Radiometer Medical AsP, Denmark) with sensors placed on the chest, forearm, earlobe or forehead. Transcutaneous BGA at 1-min intervals was compared with arterial BGA at 30 min. Reasonable steps to find severe hypercapnia with PaCO2 > 50 mmHg were evaluated.ResultsSensors on the chest and forearm were equally preferred and used because of small biases (n = 272). The average PCO2bias was close to 0 mmHg at 4 min, and was almost constant (4–5 mmHg) with PtcCO2being higher than PaCO2at ≥8 min. The limit of agreement for PCO2narrowed over time: ± 13.6 mmHg at 4 min, ± 7.5 mmHg at 12–13 min, and ± 6.3 mmHg at 30 min. The limit of agreement for PO2also narrowed over time (± 23.1 mmHg at 30 min). Subgroup analyses showed that the PaCO2and PaO2levels, gender, and younger age significantly affected the biases. All hypercapnia subjects with PaCO2 > 50 mmHg (n = 13) showed PtcCO2 ≥ 50 mmHg for until 12 min.ConclusionsAlthough PtcCO2is useful, it cannot completely replace PaCO2because PCO2occasionally showed large bias. On the other hand, the prediction of PaO2using PtcO2was unrealistic in Asian adults. PtcCO2 ≥ 50 mmHg for until 12 min can be used as a screening tool for severe hypercapnia with PaCO2 > 50 mmHg.

A 42-year-old Japanese man developed Churg–Strauss syndrome 7 years after being diagnosed with chronic eosinophilic pneumonia. Prominent eosinophilia, subcutaneous nodules, and neuropathy in the left leg were seen. A pathological diagnosis of necrotizing vasculitis was determined by a biopsy of a subcutaneous nodule. The leg pain was severe and there was prominent atrophy of the thigh and calf, but the muscle weakness was mild. Serum anti-myeloperoxidase anti-neutrophil cytoplasmic antibody was positive. Because the initial treatment with an intravenous methylprednisolone pulse at 1 g/day for 3 days was not sufficient, a onetime treatment with intravenous cyclophosphamide at 15 mg/kg and intravenous immunoglobulin therapy (IVIG) at 400 mg/kg/day for 5 days were administered. Peripheral eosinophilia improved and the leg pain significantly improved. IVIG was repeated 1 month later and symptoms gradually improved further. The early diagnosis of Churg–Strauss syndrome and the early initiation of IVIG with cyclophosphamide were thought to be important.

A 55-year-old man visited our department because of epigastric pain. Upper gastrointestinal endoscopy revealed a small, undermined ulcer in the gastric cardia. He had no history of taking NSAIDs, and was positive for Helicobacter pylori (Hp) infection. After Hp eradication therapy followed by 8 weeks of proton pump inhibitor (PPI) administration, re-endoscopy showed that the ulcer had slightly shrunk without scarring, and the surrounding mucosa was markedly elevated, like in a submucosal tumor. Endoscopic ultrasonography, performed at the same time, showed thickening of the submucosal and muscular layers around the ulcer. After continuous PPI administration, the mucosal elevation disappeared, and the ulcer shrunk and later scarred. However, when the dose of PPI was reduced with the aim of discontinuing it after the confirmation of successful Hp eradication, the ulcer recurred. We report this case of gastric ulcer because of its peculiar clinical presentation.

A man taking antithrombotic agents was admitted because of melena. Upper gastrointestinal endoscopy revealed a large, pedunculated polyp bleeding from erosions on its top. The polyp was endoscopically resected, and histopathologically diagnosed as Brunner ’ s gland hyperplasia. It is commonly encountered as a small, raised lesion, but may enlarge or bleed. We report this case, with a review of the Japanese literature and discussion of the mechanism of bleeding. doi: http://dx.doi.org/10.4021/gr532e

A 60-year-old male presented with cough and fever (case 1), and a 77-year-old female patient with hemoptysis (case 2) were admitted to IUHW Shioya Hospital. Interferon gamma release assay (IGRA: QFT-3G and T-SPOT. TB) were both performed on each patient; the QFT-3G was positive and T-SPOT.TB was negative in both cases despite different final diagnosis. While case 1 was determined to have active tuberculosis, in case 2 active tuberculosis was eliminated as the diagnosis. The contradictory results in these patients should serve as a reminder to clinicians that they should not rely on the results of IGRA testing for the diagnosis of active tuberculosis. Keywords: Interferon Gamma Release Assay; Negative; Tuberculosis; T-SPOT; QFT

A middle-aged man with no symptom or history visited our hospital due to duodenal abnormality and fecal occult blood detected by health screening. Upper gastrointestinal endoscopy showed marked enlargement of the papilla of Vater surrounded by nodules, and biopsy disclosed non-caseating granuloma. Colonoscopy yielded findings suggestive of intestinal tuberculosis such as annular ulcers. Examination of the biopsy samples failed to make a diagnosis of tuberculosis, and no pulmonary lesion was found, but whole-blood interferon gamma release assay was positive. The duodenal lesion was also suspected to be tubercular, so antitubercular drugs were administered. As this resulted in the resolution of both lesions, a definite diagnosis of tubercular papillitis of Vater was made. Duodenal tuberculosis is rare, and a localized lesion of the major duodenal papilla is extremely rare. However, this case suggests that tuberculosis must be considered in the differential diagnosis of lesions of the papilla of Vater.

Hepatopulmonary syndrome (HPS) (hypoxaemia due to intrapulmonary vasodilation and a right-to-left shunt associated with liver disease) resolves after liver transplantation. The authors describe a case of spontaneous resolution of HPS prior to liver transplantation. This patient was diagnosed with HPS associated with extra-hepatic biliary atresia when she was 10 years old. She exhibited digital clubbing, facial vascular dilation, cyanosis, and suffered from dyspnoea during exercise. The patient's PaO(2) at rest was 53.8 mm Hg in room air and a Technetium-99m macro-aggregated albumin lung perfusion scan demonstrated a right-to-left shunt. Although her symptoms and laboratory data supported a diagnosis of HPS, she nevertheless showed spontaneous resolution within 2 years. When she was 14 years old, pulmonary hypertension was evident upon examination of her echocardiogram. HPS may be improved or masked by an accidental overlap with pulmonary hypertension in the terminal stage of liver disease.

A 61-year-old man took loxoprofen sodium hydrate, a prodrug NSAID, for acute upper respiratory infection for 5 days, developed melena 2 days later, and was admitted to our hospital. Upper gastrointestinal endoscopy revealed a giant and deeply undermined ulcer mainly in the greater curvature of the antrum, which occupied halfway around the lumen. His medical history was unremarkable. He was negative for Helicobacter pylori infection, and was diagnosed with NSAID-induced acute gastric ulcer in the absence of other causes of gastric ulcer. Giant gastric ulcers, as in this patient, are rare. Moreover, deeply undermined or huge gastric ulcers sometimes develop during the long-term administration of NSAIDs, but very rarely after their short-term administration, which prompted us to report this case.

To study the inflammatory responses of small-airway epithelium in smokers, we harvested enough living epithelial cells (1.97 × 106± 0.74 × 106) with a new ultrathin fiberscope from the very peripheral airways of 22 current smokers and 17 subjects who never smoked after informed consent was obtained. The cells were keratin positive and composed mainly of nonciliated cells. The expression levels of inflammatory markers [interleukin (IL)-8 and intercellular adhesion molecule (ICAM)-1] were evaluated with RT-PCR. The magnitude of the mRNA levels corrected by β-actin transcripts of IL-8 and ICAM-1 was significantly higher in the smokers than in the nonsmokers ( P < 0.001). Furthermore, among current smokers, IL-8 mRNA levels correlated positively with the extent of smoking history [in pack ⋅ years (packs/day × no. of years of smoking); r = 0.754, P < 0.001]. Spontaneously released IL-8 and soluble ICAM-1 levels ( n = 12) from cultured epithelial cells were elevated in subjects with a smoking history than in those without it (IL-8, 1,580 ± 29.6 vs. 354 ± 39.4 pg ⋅ 106cells−1⋅ 24 h−1; P < 0.001; soluble ICAM-1, 356.0 ± 45.9 vs. 112.9 ± 12.9 pg ⋅ 106cells−1⋅ 24 h−1; P < 0.01 by Student's t-test ). In contrast, the epithelial cells from the main bronchi did not show such differences between smokers and nonsmokers. Our study highlighted a close link between smoking and the expression of inflammatory mediators such as IL-8 and ICAM-1 in small airways. Our results also suggested that this new ultrathin bronchofiberscope promised a good approach for the evaluation of cellular changes in the small airways.

Smoking cessation decreases oxidative stress and restores vascular endothelial function. However, a recent meta-analysis suggests that the use of varenicline, a α4β2 nicotinic acetylcholine receptor partial agonist, increases the risk of cardiovascular events. This study was designed to determine the effect of varenicline-assisted smoking cessation on vascular endothelial function. Study subjects were 11 healthy Japanese males (mean age, 54.4 years) without evidence of cardiovascular disease who were eager to quit smoking. Each subject was treated with varenicline titrated up to 1.0 mg twice daily. We evaluated serum derivatives of reactive oxygen metabolites (d-ROMs) as a marker of oxidative stress, and flow-mediated dilation (FMD) of the brachial artery as a marker of vascular endothelial function. Both measurements were performed before and 3 months after completing smoking cessation. All subjects gained weight (average, 1.7 kg) after smoking cessation. However, there were no significant differences in the following parameters before and after smoking cessation: systolic blood pressure, diastolic blood pressure, heart rate, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, glucose and hemoglobin A1c. Serum d-ROM levels significantly decreased from 340.7±70.4 to 300.0±43.2 U.CARR (P=0.012), and FMD significantly increased from 3.36±1.26 to 5.25±1.33% (P=0.00067) after smoking cessation. There was an inverse correlation between FMD and serum d-ROM levels (R=-0.377; P=0.043). Our observations suggest that varenicline-assisted smoking cessation restores vascular endothelial function, and this is associated with decreased oxidative stress, despite an increase in body weight. As varenicline-assisted smoking cessation possibly has beneficial effects on vascular endothelial function, it might also reduce cardiovascular risk.

Objectives: A meta-analysis suggested that the use of varenicline, which is a partial agonist of nicotinic acetylcholine receptors and is effective in smoking cessation, increases the risk of cardiovascular events within 52 weeks of starting treatment. Defining these events as occurring during drug treatment (usually for 12 weeks) or within 30 days of discontinuation, another meta-analysis showed that the risk was statistically insignificant. In the present study, we aimed to clarify the effect of varenicline-assisted smoking cessation on vascular endothelial function assessed by flow-mediated vasodilation (FMD). Design: Before–after and time-series. Setting: Tochigi Prefecture, Japan. Participants: Data of 85 participants who visited nicotine-dependent outpatient services were reviewed. FMD was repeatedly measured in 33 of the 85 participants. Inclusion criteria: 20 years and older, Brinkman index ≥200, Tobacco Dependence Screener ≥5 and stated motivation to quit smoking. Interventions: Each participant was treated with varenicline titrated up to 1.0 mg twice daily (for 12 weeks in total). Primary and secondary outcome measures: Participants were evaluated by FMD prior to, and 3 months after, complete smoking cessation. Follow-up FMD measurements were carried out every 3 months if possible. Changes in FMD during varenicline use were also evaluated. Results: FMD was significantly increased from 4.0±1.8% to 5.5±2.2% (p

胸部X線所見分類で孤立結節性陰影1例, 多発粟粒状結節性陰影1例, 肺炎様陰影3例の細気管支肺胞上皮癌5例を胸部単純X線写真, X線CTと細気管支鏡所見を対比し検討した. 内視鏡所見は肺炎様陰影を呈した症例では細気管支は漿液性の分泌物が多く肺胞の方から湧き出てくる像がみられ, また, 細気管支に粘膜下主体型の腫瘍および閉塞像が認められた. 散在するポリープ様変化も認められ本症の進展形式を示唆した. 孤立結節性陰影の症例では結節隆起型の腫瘍がみられた. 多発粟粒状結節性陰影の症例では細気管支は全般的に狭窄を起こし粘膜面が蒼白に認められた. 初めて本症を内視鏡で観察することが出来た.

Six cases of gastric antral ulcer with an unknown cause encountered at our hospital and related facilities during the last 5 years were evaluated. The frequency of the disease was 1.3% of all gastric ulcers. The lesions were multiple in 3 and solitary in 3. All these lesions were ellipsoidal and small ulcers 1 cm or less in long diameter with mucosal elevations around them, located primarily in the greater curvature, and accompanied by reddened erosions in other areas of the antrum. The patients were middle-aged or older, 5 of them were females, half of them had a history of bleeding, and 4 showed resistance to treatment with proton pump inhibitors. The 6 patients had common clinical features, suggesting that they had the same disease. From the presence of reddened erosion, mutual friction of the antral mucosa was suspected to be a cause of the disease. Similar ulcers are found in the literature, but they have not been described or evaluated in detail. The further accumulation of cases and clarification of details of the disease are desired.

A 65-year-old man developed severe septic shock during thrombolytic treatment with urokinase for pulmonary thromboembolism associated with deep venous thrombosis of the right lower limb. Blood cultures were positive forKlebsiella pneumoniae and treatment was successful only when the antibiotics were infused via the same route as the urokinase.

A 52-year-old man with chronic granulomatous interstitial pneumonitis suffered from invasive group A streptococcal infection. His chest x-ray showed bilateral interstitial shadows in the lower lung fields since childhood. He was admitted to Keio University Hospital because of fever, productive cough, and necrosis of the distal extremity. The chest radiographic appearance worsened and he developed low blood pressure, liver dysfunction, thrombocytopenia, and lymphocytopenia. Blood culture yielded T-11 strainStreptococcus pyogenes, which generated type B and C pyrogenic exotoxins. This may be the first report to confirm T-11Streptococcus pyogenes as the causative organism for invasive group A streptococcal infection in Japan. The patient's condition improved after treatment with panipenem and subsequent combination therapy with high-dose penicillin G and gentamicin. An immunodeficiency state associated with the chronic granulomatous lung disease was strongly suspected.

We developed a new type of bronchoscope (BF-2.7T) and cytology brush (BC-0.7T) that permit collection of pulmonary cells during direct observation of the small airways. This kind of cell collection has been previously impossible. With our cytology brush, 3.58 +/- 2.76 x 10(4) cells were collected from small airways. The rate of living cells was 33.13 +/- 3.61 percent from the small airways. Analysis of endoscopic findings and investigation of pulmonary cells are very important for elucidating the pathophysiologic state of the small airways. The use of the BF-2.7T allowed collection of cancer cells under direct endoscopic vision in all five patients with peripheral lung cancer. They also contribute to our understanding of the relationship between exogenous factors and cells that compose the lung, and will provide means for treatment and prevention of diseases.

In order to assess the physiological abnormalities and the pathogenesis of adult respiratory distress syndrome (ARDS), especially that associated with pulmonary fat embolism, acute lung injury caused by monounsaturated nonsterified fat oleic acid (cis-9-octadecenoic acid) has been widely used in animal experiments. This lung injury results in an extensive, multifocal, and heterogeneously distributed lung damage with alveolar flooding, interstitial edema and microatelectasis. The ability to reduce the perfusion entering into damaged and edematous areas is essentially important in preserving blood oxygenation in ARDS.

In order to assess the physiological abnormalities and the pathogenesis of adult respiratory distress syndrome (ARDS), especially that associated with pulmonary fat embolism, acute lung injury caused by monounsaturated nonsterified fat oleic acid (cis-9-octadecenoic acid) has been widely used in animal experiments. This lung injury results in an extensive, multifocal, and heterogeneously distributed lung damage with alveolar flooding, interstitial edema and microatelectasis. These morphological changes have generally been considered to develop significant shunt flow causing severe hypoxemia and loss of lung compliance. Based on the microscopic examinations, however, Schoene et al. (1984) have failed to demonstrate a quantitative relationship between the morphological alterations and the amount of shunt in dogs with lung damage induced by oleic acid administration. Further, Brigham et al. (1983) have shown that gas exchange abnormality in patients with ARDS does not correlate with extent of pulmonary edema estimated from extravascular lung water but significantly with vascular permeability-surface area. They have inferred from their experimental findings that the ability of the lung circulation to reduce perfusion of damaged and edematous areas is essentially important in preserving blood oxygenation in ARDS.

We developed a method for estimating the distribution of ventilation V A ) and of diffusing capacity (G) to perfusion (Q) in the lungs. We used O 2 , CO 2 and CO together with six inert gases of widely differing solubility and assumed that mass transfer efficiency of each gas in a gas exchange unit is limited by both V A /Q and G/Q ratios. The underlying lung model comprised 20 units along both the V A Q and G/Q axes. Using numerical analysis, we transformed the data into a virtually continuous distribution of Q in the V A /Q-G/Q field. We tested the precision of the numerical procedure by examining the recovery of various artificial distributions, and found that distributions with up to two modes could be recovered with reasonable accuracy. Analytical results from 15 patients with interstitial pneumonia of unknown etiology (IPF) revealed the following features. (1) In an early disease stage, most of the lung was operating in the range of normal V A /Q, without a significant contribution of diffusion limitation. (2) An advanced stage of the disease exhibited a widening of V A /Q distribution and either broad unimodal or bimodal distribution of G/Q, extending to G/Q below 10 −3 ml (STPD)/(ml·Torr) with diffusion-limited O 2 exchange. (3) Severe diffusion limitation causing disequilibrium of inert gas across the blood-gas barrier was observed in three (far advanced fibrosis; active interstitial inflammation) out of 15 patients. These findings suggest that inhomogeneity of G/Q does exist and may play an appreciable role in causing impairment of gas exchange in patients with interstitial pneumonia.

Wistar Imamichi rat and human respiratory cilia were examined with anti-dynein antibody (AD2), which is specific for sea urchin sperm flagellar dynein. AD2-labelled fresh-frozen normal rat and human cilia stained clearly by immunofluorescence and the peroxidase-antiperoxidase (PAP) technique. On immunoelectron microscopy, AD2 labelled the outer dynein arms of normal human cilia. Paraffin-embedded normal human cilia also stained by immunofluorescence, although not always clearly. Neither the cilia of WIC-Hyd male rats, an animal model of Kartagener's syndrome, nor human cilia from patients with primary ciliary dyskinesia (PCD) reacted positively by the immunofluorescence or PAP technique. Western blots of normal rat cilia yielded a single band of about 450 kDa. In conclusion, AD2 recognizes the outer arm dynein heavy chains of healthy cilia and may be useful in diagnosing and classifying PCD light microscopically especially when only paraffin-embedded specimens are available. This approach may be of potential use for better defining and classifying PCD.