[Natural history of cloudy zone of pulmonary adenocarcinoma on HRCT]

Seven pulmonary adenocarcinomas with cloudy zone (CZ), which was defined as a lower density zone in the pulmonary lesion than pulmonary vessels in the surrounding normal lung on high resolution computed tomography (HRCT), were followed up for at least 3 months. There were three tumors with homogeneous CZ, one of which showed no change when rescanned after three months, the others showed enlargement with or without replacement by high density areas on rescanned images obtained after more than one year. Two tumors containing some high density areas on the initial scans showed slight decreases in size on rescanned images obtained after 1 to 3 months. However, on rescanned images obtained after more than 1 year and 9 months, these tumors also showed enlargement of CZ. Pathologically, CZs corresponded to well-differentiated adenocarcinoma of the bronchioloalveolar type with no or mild interstitial change, whereas high density areas mainly corresponded to papillary adenocarcinoma with severe interstitial fibrosis. In conclusion, long-term careful follow-up of CZ is necessary to detect enlargement or the appearance of high density. Unchanged CZ in short-term follow-up should be considered a finding suggestive of malignancy.

Disrupted murine leukemia inhibitory factor (LIF) gene attenuates adrenocorticotropic hormone (ACTH) secretion

Leukemia Inhibitory Factor (LIF) and its receptors in human and mouse pituicytes are expressed abundantly in corticotrophs and somatotrophs. As LIF induces POMC transcription and LPS-mediated stress also induces hypothalamic and pituitary LIF expression, we studied ACTH secretion in LIF knockout (LIF KO) mice. Basal ACTH levels were lower in LIF KO mice (p<0.05) and after 36 hours fasting, LIF KO mice had lower ACTH levels (38% of WT littermates, p=0.014 ). Delivery of LIF (1.2 microg/day) via implantation of subcutaneous osmotic pumps restored ACTH (p=0.006 vs PBS replacement) and corticosterone (p=0.02 vs PBS replacement) levels within three days. After five days, pumps were removed and two days later, ACTH levels had reverted to pre-treatment values. In contrast, GH concentrations were attenuated by LIF replacement to LIF KO mice. Thus, absence of LIF in LIF KO mice results in attenuated ACTH levels indicating that LIF plays an important intrapituitary role in HPA axis development and regulation.

Identification of IGF-I in the calvarial suture of young rats: histochemical analysis of the cranial sagittal sutures in a hyperthyroid rat model

Premature closure of cranial sutures has been known as one of the complications of juvenile or congenital hyperthyroidism. Thyroid hormone is an anabolic agent for bone formation in the early stages of childhood development. In children, excess thyroid hormone acts as an acceleration factor for the skeletal bone, whereas in adult hyperthyroidism, it causes bone mineral loss due to the high turnover rate of bone formation and consequently bone resorption. In addition, there are numerous literature descriptions concerning the interactions among bone metabolism, hormones, and growth factors, among which insulin-like growth factor I (IGF-I) is the most abundantly found growth factor in osteoblasts and in bone models in vivo. We therefore investigated whether or not the cranial sutures show accelerated closure and how the local growth factors or cytokines participate and function in local bone metabolism after administration of exogenous excess thyroid hormone in a rat model. A total of 60 female Wistar rats, aged 10 days, were divided into two groups, the triiodothyronine (T3)-treated group (n = 30, T3 0.1 microgram/gm of body weight per day) and the control group (n = 30, saline vehicle only), and were maintained and subsequently sacrificed at 15, 30, and 60 days. The parameters of cranial width derived from the morphologic measurements of the skull indicated that the lambda-asterion distance at 30 days and the pterion-bregma distance at 60 days in the T3-treated group were significantly decreased compared with those of the control group. Furthermore, the fluorescent histologic findings showed fluorescent labeling with no interruption along the suture edges, suggesting continuous bone formation, and displayed narrowing of the suture gap of the sagittal suture in the T3-treated group. Tartrate resistant acid phosphatase staining showed very little osteoclastic activity in the sagittal suture, especially in the T3-treated group. The intensity of immunohistochemical staining of IGF-I was markedly increased in the suture margins of the T3-treated group. There were no significant differences observed either in the skull base measurements or in the histologic and histochemical findings of the skull base or the coronal suture between the groups. More significantly, excess administration of thyroid hormone enhanced the cranial sagittal suture closure; therefore, it was proposed that local IGF-I plays an important role in sagittal sutural bone formation.

Classification of air density areas in CT-pathologic correlation of pulmonary adenocarcinoma

Air density areas (ADAs) such as air bronchogram, bubble-like area, and cavity on high resolution computed tomography (HRCT) of pulmonary adenocarcinoma were examined to clarify their pathological implications. Forty-two resected specimens of pulmonary adenocarcinoma were histopathologically examined in correlation with the HRCT findings with particular emphasis on ADAs. Forty-one ADAs observed in 32 of 42 cases with pulmonary adenocarcinoma were classified into three types: air bronchogram type (n = 22), bubble-like area type (n = 12), and cavity type (n = 8). Twenty of 22 air bronchogram ADAs corresponded to bronchi. Nine of 12 bubble-like area ADAs corresponded to bronchioles. Only one of eight cavity-ADAs consisted of necrosis. The classification of ADAs in pulmonary adenocarcinoma is considered to be useful in interpreting HRCT findings of pulmonary nodules.

Cloudy nodule on HRCT: a new clinico-radiologic entity of pulmonary adenocarcinoma

We propose cloudy nodule (CN) on HRCT as a special type of pulmonary adenocarcinoma. CN was defined as a cloudy nodular shadow in the peripheral part of the lung with lower density than pulmonary vessels on HRCT. Radiologic images of nine CNs in eight cases were correlated with the pathological findings of the resected specimen. All CNs were clearly demarcated on HRCT. They were pathologically composed of well differentiated adenocarcinoma, mainly bronchioloalveolar type with little or no central scar. Plain films were negative in six of nine cases. CN on HRCT may indicate well-differentiated adenocarcinoma with good prognosis.

Left ventricular isovolumic relaxation flow and left ventricular systolic performance

We investigated isovolumic relaxation flow in patients with coronary artery disease (CAD) and evaluated the relationship between its velocity and left ventricular performance in 23 patients with atypical chest pain, 30 patients with CAD without prior myocardial infarction (MI), and 57 patients with prior MI, in whom cardiac catheterization was performed. The isovolumic relaxation flow velocity was measured at the basal portion of the left ventricle with pulsed Doppler echocardiography. The isovolumic relaxation flow ( > 15 cm/sec) was detected in 98 of 110 patients. The isovolumic relaxation flow velocity was significantly lower in patients with prior MI than in patients with atypical chest pain (p < 0.001) and in those with CAD without prior MI (P < 0.05). It was significantly lower in patients with CAD without prior MI than in those with atypical chest pain (p < 0.05). The isovolumic relaxation flow velocity showed a significant positive correlation with left ventricular ejection fraction. It also showed a significant negative correlation with left ventricular end-systolic volume index. These findings suggest that the isovolumic relaxation flow velocity is decreased in patients with CAD and is influenced by left ventricular systolic performance. Isovolumic relaxation flow may be a clinical manifestation of elastic recoil of the left ventricle.

Diastolic mitral annular motion in normal subjects and patients with coronary artery disease

The purpose of this study was to evaluate the characteristics of mitral annular motion during diastole in 28 normal subjects, 40 patients with prior myocardial infarction (MI), and 23 patients with coronary artery disease but without prior MI. Mitral annular motion during diastole was obtained from the apex by M-mode echocardiography at the posterior wall of the left ventricle. Determinants of mitral annular excursion during early (MAE-E) and late diastole (MAE-L) were investigated in all subjects. Differences in the MAE-E, MAE-L, and the MAE-L:MAE-E ratio were compared among the three patient groups. The Doppler-derived transmitral flow velocity-time integral during early (EI) and late (AI) diastole and mitral annular excursions during diastole were obtained in 55 other patients with a prior MI and in 29 healthy volunteers. The relationships between the MAE-L:MAE-E ratio and AI:EI ratio in these two groups were studied. The MAE-E was determined mainly by heart rate and left ventricular ejection fraction (LVEF). The MAE-L was determined only by age. The magnitude of MAE-E was significantly less in patients with a prior MI than in normal subjects (P < 0.01). However, the MAE-L did not differ among the three groups. The MAE-L:MAE-E was higher in patients with a prior MI than in normal subjects (P < 0.05), and was significantly correlated with AI:EI in healthy volunteers (r = 0.65, P < 0.001) and in patients with a prior MI (r = 0.50, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Craniofacial deformities associated with juvenile hyperthyroidism

Three juvenile cases of thyrotoxic craniosynostosis are reported. Two patients had small heads with posterior slanted foreheads. Skull expansion was performed in one patient. Various degrees of ocular proptosis and shallow orbits without enlargement of the extraocular muscles were seen in all cases. Zygomatic repositioning for zygomatic hypoplasia and exophthalmos was performed in two patients. The facial skeleton was involved in thyrotoxic craniosynostosis in these children, and their clinical features seemed to resemble craniofacial dysostosis.

[High-resolution CT findings of Pneumocystis carinii pneumonia]

High resolution CT (HRCT) was performed on 7 patients with pneumocystis carinii pneumonia (PCP). Six cases were proven bacteriologically by bronchoalveolar lavage; one case was proven by autopsy. Three patients were re-scanned after specific treatment and symptomatic relief. All the CT scans were abnormal, usually showing bilateral diffuse ground-glass opacity, through which the pulmonary vessels remained visible. Chest X-ray, on the other hand, showed a normal pattern in one patient. Other changes such as air space consolidation (in 4 cases) and thickening of peripheral pulmona vessels (in 2 cases) were also seen. Air space consolidation was found in three cases with mixed infection (cytomegalovirus pneumonia in 2 cases, aspergillosis in one case). No patient showed significant mediastinal or hilar lymph node enlargement, pleural effusion or cystic pulmonary change. HRCT findings such as ground-glass opacity and air space consolidation were shown to disappear in some cases of PCP after specific treatment. HRCT is useful to evaluate the sequential pulmonary changes after the specific therapy.

Effects of volume loading on pulmonary venous flow pattern in dogs with normal left ventricular function

The effects of altered loading conditions on the pattern of pulmonary venous flow are poorly understood. The authors investigated such effects, therefore, by using volume loading in 6 open-chest dogs. The pulmonary venous flow volume rate curve was obtained with a transit-time ultrasonic flowmeter at a fixed heart rate. Measurements were performed in the control and several states during the intravenous infusion of dextran. The influences of volume loading on hemodynamic and pulmonary venous flow variables were compared between the control state and three interventional states in which mean left atrial pressure was approximately 1, 2, and 3 mm Hg above the control value. The systolic flow volume (SI), which corresponds to left atrial reservoir volume, significantly increased, but the early diastolic flow volume (DI), which corresponds to left atrial conduit volume, did not show significant change with volume loading. The flow volume during left atrial contraction significantly increased with volume loading. The flow volume during one cardiac cycle (PVF) significantly increased with volume loading. Approximately 73% of increased PVF was distributed to the systolic flow. The rest was distributed to the early diastolic flow (14%) and to the flow during left atrial contraction (12%). The change in the ratio of SI/DI significantly and positively correlated with the change in mean left atrial pressure (r = 0.87, P < 0.001). These findings indicate that increased pulmonary venous flow induced by volume loading in dogs with normal left ventricular function is mainly distributed to the left atrial reservoir volume.

Human and murine pituitary expression of leukemia inhibitory factor. Novel intrapituitary regulation of adrenocorticotropin hormone synthesis and secretion

Leukemia inhibitory factor (LIF) gene expression was detected in human fetal pituitary tissue by expression of LIF mRNA transcripts, protein immunocytochemistry, and immunoelectron microscopy. Fetal LIF immunoreactivity colocalized with 30% of ACTH-expressing cells, approximately 20% of somatotrophs, and approximately 15% of non-hormone-expressing cells. LIF was also strongly expressed in normal adult pituitary and in four growth hormone-producing and two ACTH-producing adenomas, but not in eight nonfunctioning pituitary tumors. Culture of fetal cells expressing surface LIF-binding sites demonstrated predominance of in vitro ACTH secretion as compared with other pituitary hormones. In AtT-20 murine cells, LIF (ED50 10 pM) stimulated basal proopiomelanocortin mRNA levels by 40% and corticotropin-releasing hormone-induced ACTH secretion (two- to threefold), as did oncostatin M (ED50 30 pM), a related peptide. ACTH responses were not further enhanced by both cytokines together, which is consistent with their shared receptor. Anti-LIF antiserum neutralized basal and LIF-induced ACTH secretion, suggesting autocrine regulation of ACTH by LIF. The results show that human pituitary cells express the LIF gene and LIF-binding sites, predominantly in corticotrophs. Pituitary LIF expression and LIF regulation of proopiomelanocortin and ACTH reflect an intrapituitary role for LIF in modulating early embryonic determination of specific human pituitary cells and as a paracrine or autocrine regulator of mature ACTH.

Clinical significance of reverse redistribution on 24-hour delayed imaging of exercise thallium-201 myocardial SPECT: comparison with myocardial fluorine-18-FDG-PET imaging and left ventricular wall motion

Clinical significance of reverse redistribution on 24-hr delayed images after exercise 201Tl myocardial SPECT was investigated in 16 patients with recent myocardial infarction.

METHODS

Findings of 24-hr delayed 201Tl SPECT imaging were compared with those of glucose-loaded 18F-fluorodeoxyglucose (FDG) imaging by myocardial PET and with left ventricular wall motion obtained by bi-plane contrast left ventriculography. In each patient, transaxial thallium images and corresponding 18F-FDG images were divided into five ROIs.

RESULTS

Reverse redistribution was found in 15 of 80 regions. The mean FDG activity score in regions with reverse redistribution was significantly lower than that in regions having normal or slightly decreased thallium activity on 24-hr delayed imaging; it was significantly higher than that in regions having severely decreased or no thallium activity on 24-hr delayed imaging. The mean wall motion score in regions with reverse redistribution was significantly lower than in regions with normal or slightly decreased thallium activity, however, it was significantly higher than that in regions with moderately or more decreased thallium activity.

CONCLUSION

These findings demonstrate that in regions showing reverse redistribution on 24-hr delayed 201Tl imaging, myocardial exogenous glucose utilization and left ventricular wall motion had deteriorated, but were not on a level with the scar.

Thyroid hormone action on rat calvarial sutures

To clarify the effect of thyroid hormone on the calvarial sutures, the morphology, histology, and bone mineral density were analyzed in thyroid hormone-injected rats. A total of 80 female Wistar rats at the age of 10 days were divided into 2 groups; the triiodothyronine (T3)-treated rats (n = 40, T3 100 micrograms/kg body weight/day) were maintained under the same conditions as controls (n = 40, saline-vehicle only), and both were sacrificed at 50, 80, and 200 experimental days, respectively. T3-treated animals showed smaller values of lambda-asterion and pterion-bregma distances at the various periods of examination, resulting in smaller sizes in right-left direction of the skull. The sagittal suture distance in the skull specimens observed by Goldner's staining (fibrous tissue content) appeared smaller and the osseous margin widths greatly increased in the T3-treated rats. Fluorescent microscopy revealed that the tetracycline-calcein double labelings were not interrupted from the periosteal to the endosteal areas in any specimens indicating the scantiness of osteoclastic activity in the suture areas. Mineral apposition rates at the osseous edges of the suture were significantly increased in the T3-treated rats (p < 0.01 at the age of 90 days). The distance between the second labels and the distance between the first labels were significantly larger in the T3-treated rats. Bone mineral density (BMD) measurement showed that the T3 administration decreased only the calvarial BMD at the age of 210 days (p < 0.01), but did not decrease lumbar or femur BMD. This experiment demonstrated clear evidence of excess thyroid hormone action on the early narrowing of the sagittal suture in infantile hyperthyroid rats, probably due to the enhanced osteogenic activity caused by the hormone.

Detection of coronary artery stenosis by dipyridamole radionuclide ventriculography

We assessed the usefulness of dipyridamole radionuclide ventriculography for detecting significant coronary artery stenosis in 89 patients who were undergoing cardiac catheterization. Radionuclide ventriculography was performed before and after the infusion of dipyridamole (0.56 mg/kg). The end-diastolic regions of interest of the left ventricle were divided into 5 sectors for calculation of the regional ejection fractions. Results were considered to be positive when the regional ejection fraction decreased by more than 5% after the infusion of dipyridamole. The presence of significant coronary artery stenosis (> 75%) was demonstrated by arteriography in 49 patients and was absent in 40 patients. A decrease in the regional ejection fraction greater than 5% was observed in 41 (84%) of the 49 patients with significant coronary artery stenosis and in 2 of the 40 without significant coronary stenosis. The sensitivity and specificity of this method for detecting significant coronary artery stenosis were 84% and 95%, respectively. We conclude that a decrease in the radionuclide-determined regional ejection fraction after the infusion of dipyridamole reflects left ventricular dysfunction and is a sensitive and specific indicator of significant coronary artery stenosis.

Modified coronal incision: distribution of stress in the scalp and cranium

Coronal incision or bitemporal incision is useful for wider visualization in craniofacial surgery. In volume-expanding surgery such as fronto-orbital advancement, however, the incisional scar in the temporal scalp is often undesirably wide and conspicuous. We modified the coronal incision to avoid the widened scar. Further, we analyzed the resulting stress distribution using the finite element method (FEM) to determine whether or not the modification we adapted was effective. The modified method of coronal scalp incision that we used for craniofacial surgery is practical and technically easy. FEM analysis showed that our method was effective in terms of mechanical strength. The simulated surgical craft model is presented and is concluded to be beneficial for further analysis in craniofacial surgery.

[Brain SPECT by intraarterial infusion of 99mTc-HMPAO for assessing the cerebral distribution of carotid artery infusions in patients with brain tumor]

In order to assess the cerebral distribution of intracarotid chemotherapy, 17 postoperative patients with brain tumor underwent brain SPECT obtained by intraarterial infusion of 18.5 MBq of 99mTc-HMPAO. Injection methods were continuous (5.0 ml/min) or pulsatile infusion with supraor infraophthalmic catheterization. The findings obtained by brain SPECT were frequently different from those of angiography and/or DSA. In supraophthalmic catheterization with continuous infusion, only 2 of 10 studies (20%) had homogeneous distribution and 5 of them (50%) had maldistribution of 99mTc-HMPAO which appears in association with laminar flow effect. The remaining 3 studies showed localized distribution (two: tumor localization, one: healthy brain localization). On the other hand, all of 5 studies with pulsatile infusion had homogeneous distribution of 99mTc-HMPAO. In infraophthalmic catheterization, all but one of 5 studies had homogeneous distribution with continuous infusion. These results suggest that pulsatile infusion may be effective in eliminating maldistribution of 99mTc-HMPAO in supraophthalmic catheterization. In conclusion, we are convinced that 99mTc-HMPAO is a useful intraarterial agent for assessing cerebral distribution of intracarotid chemotherapy.

[Reassessment of usefulness of salivary scintigraphy in diagnosis of Sjögren's syndrome]

Dynamic salivary scintigraphy using 99mTcO4- was performed in 95 patients (a total of 366 glands) suspected of Sjögren's syndrome (SjS) and the results were compared with SjS diagnostic criteria by the Japanese Welfare Ministry. Time-activity curve of ROI created over each salivary gland was classified into four patterns, that is, N, M1, M2, F pattern, depending upon trapping, accumulation and secretion response to the tartaric acid. In definite SjS patients, most of the patients had different patterns in the four glands, and classical F (flat) pattern in all of the four glands was uncommon (3/38, 8%). F and/or M2 (no response to secretary stimulation) patterns were seen in 68.5% (98/143) of the all glands. Provided that F and/or M2 patterns in 2 or more glands is scintigraphic criteria for diagnosis of SjS, sensitivity, specificity and accuracy were 82.9%, 59.5%, 70.8%, respectively. As for salivary uptake of 99mTcO4-, there is a significant difference between the patients with definite SjS and control subjects (parotis p < 0.05, submandibular gland p < 0.01), but there is no significant difference among the patients with definite SjS, suspected SjS and chronic sialoadenitis. In conclusion, the four patterns classification may have potential in screening patients with SjS.

EC syndrome in a girl with paracentric inversion (7)(q22.1;q36.3)

Ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome associated with a paracentric inversion of chromosome 7 in a 2-year-old Japanese girl is reported. She had sparse and light-brown hair, bilateral cleft lip and palate, fused lower incisors, a pigmented skin lesion at the neck, accessory nipples, limited extension of elbow joints and bilateral ectrodactyly of hands and feet. Cytogenetic studies demonstrated a balanced inv(7)(q22.1;q36.3) in the patient and her father. The association of EEC syndrome and inv(7) in the patient suggested a putative locus of the EEC syndrome gene either at 7q22.1 or 7q36.3, although a coincidental occurrence of the two conditions is an alternative explanation. A comparison with reported karyotypes in patients with EEC or isolated ectrodactyly favoured 7q22.1 as the locus. A normal phenotype of the father in our family might reflect reduced penetrance of the EEC syndrome or, possibly, reduced expression of a maternally-derived allele of the EEC syndrome gene through a genomic imprinting mechanism.

Noninvasive evaluation of left ventricular performance by the shortest distance between mitral leaflets coaptation and interventricular septum at end-systole

We attempted to evaluate left ventricular performance from the shortest distance between the mitral leaflets coaptation and the interventricular septum at end-systole (MVC-IVS distance). The subjects were 37 patients with coronary artery disease (CAD) with prior myocardial infarction (MI), 8 with CAD without prior MI, 22 with atypical chest pain, and 4 with aortic regurgitation. The MVC-IVS distance was measured on a two-dimensional echocardiogram obtained from the parasternal or apical long-axis view and frozen at end-systole. Left ventricular end-systolic volume and end-diastolic volume were obtained by left ventriculography, and the left ventricular ejection fraction was calculated. A significant positive correlation was observed between the MVC-IVS distance and the end-systolic volume (r = 0.83, p less than 0.001); a close correlation was observed between the MVC-IVS distance end-systolic volume and ejection fraction by monoexponential fitting (r = -0.91, p less than 0.001). Thus, a significant negative correlation was observed between the MVC-IVS distance and the left ventricular ejection fraction (LVEF) (r = -0.83, p less than 0.001). An MVC-IVS distance of greater than or equal to 30 mm suggests diagnosis of left ventricular dysfunction (LVEF less than 50%) with high sensitivity (94.4%) and specificity (90.6%), while a value less than 30 mm suggests that the left ventricular performance is likely to be normal. Thus one can easily evaluate the left ventricular performance noninvasively using this new index.

[Reassessment of radionuclide-venography for deep vein thrombosis in the lower extremities and pelvic cavity using 99mTc-MAA]

We performed radioisotope (RI)-venography in 31 patients suspected of deep vein thrombosis (DVT), and 18 patients of them (58.1%) had abnormal findings. Out of the 18 patients, 14 satisfied the diagnostic criteria for DVT, that were interruption in the venous flow with the presence of collateral circulation. Sensitivity, specificity and accuracy of RI-venography for DVT were 100%, 76%, 87%, respectively. In all of the patients with chief complaints of edema and pain in the unilateral extremity DVT was found by RI-venography. Lung scan revealed multiple pulmonary perfusion defects in 4 (33.3%) of 12 patients with DVT. Out of the 4 patients, 3 (75%) had silent pulmonary thromboembolism. 99mTc-MAA accumulation was seen in the left lobe of the liver in a patient with occlusion of the IVC and common iliac veins. We are convinced that patients with PTE and/or edema and pain in the unilateral lower extremity should undergo routine RI-venography. In conclusion, RI-venography using 99mTc-MAA was reassessed and we obtained the result that it is useful for screening and monitoring DVT and pulmonary thromboembolism.

[Clinical evaluation of life size image of Fuji computed radiography for detection of diffuse interstitial lung diseases]

To evaluate the diagnostic accuracy of Fuji Computed Radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 cases of subtle interstitial abnormalities, there was no difference between FCR and conventional radiographs in the detection of any pulmonary abnormality, ground-glass opacities and reticular or linear shadows. There was also no difference between the two images in the detection of diffuse nodular shadow and pulmonary emphysema. These results indicate that FCR life-size images at a pixel size of 0.1 mm are useful for the detection of diffuse interstitial lung diseases.

Effect of calcium channel blocking agents on the reductive metabolism of halothane

The effect of calcium channel blocking agents on the reductive metabolism of halothane in liver microsomes of guinea pigs was investigated. The reaction mixture for the measurement of the end products consisted of microsomal suspension, 5 mM NADPH, calcium channel blocking agents (verapamil, diltiazem, nicardipine and nifedipine) and halothane in 0.1 M phosphate buffer (pH 7.4). The reductive metabolism of halothane was inhibited competitively by verapamil, diltiazem and nicardipine. The binding spectra for the interaction of these three drugs with cytochrome P-450 in microsomes were investigated. Verapamil caused the reverse type I difference spectrum and diltiazem caused the type I difference spectrum. However, the change caused by nicardipine was not observed by the presence of its specific spectra. NADPH-cytochrome P-450 reductase activity in microsomes did not change by the addition of these three drugs. These results suggest that these three calcium channel blocking agents inhibit the production of radical intermediates during the reductive metabolism of halothane.