Serum antibody against Helicobacter pylori assayed by a new capture ELISA

We developed a highly specific detection technique for serum antibody, using a monoclonal antibody to a specific antigen of Helicobacter pylori. A monoclonal antibody preparation that reacted with the 54-kDa molecule of H. pylori antigens was obtained. Using this preparation, an antigen-capture enzyme-linked immunosorbent assay (ELISA) was established by fixation of the monoclonal antibody, followed by reaction with sonicated whole cell antigens. The serum antibody titers of patients with gastritis and peptic ulcers were significantly higher than control titers, and the antibody titer correlated with the histological severity of gastritis. Patients positive for H. pylori by bacterial culture had higher titers than H. pylori-negative patients. Our new ELISA may be useful for the diagnosis of H. pylori infections and for evaluation of the severity of gastric inflammation.

[Thymic lymphoid hyperplasia of myasthenia gravis patients: correlation with clinical features and efficacy of thymectomy]

Thirty nine thymus tissues from myasthenia gravis patients without thymoma who underwent extended thymectomy were evaluated on thymic lymphoid hyperplasia with special emphasis on clinical features and the efficacy of thymectomy. Of 39 patients, 31 were women, but 3 of 7 patients without thymic lymphoid hyperplasia were men. The hyperplastic index of the thymus correlated largely with serum anti-Ach-R antibody titers before surgery. Age, myasthenic type and preoperative duration of the symptoms were almost unrelated to the hyperplastic change in the thymus. The effect of thymectomy was more remarkable in the patients with the hyperplastic thymus than that in them without it, who obtained still no remission after surgery, although the remission rate of them with it reached to 25%. Of 7 patients without the hyperplastic thymus, 4 had no detectable antibody to acetylcholine receptor, whereas in 32 patients with it only 2 were seronegative. This negative immunological factor might make adverse response to thymectomy. Although unfavorable response to thymectomy were observed in the patients without the hyperplastic thymus, most of them were significantly improved through a supplementary treatment with steroid after surgery. Thymectomy was a favorable treatment for myasthenia gravis patients with thymic lymphoid hyperplasia, whereas in them without it the result of thymectomy was unsatisfactory.

Relationship between respiratory muscle strength and lean body mass in men with COPD

It has been suggested that low body weight may be associated with decreased respiratory muscle function in COPD, but the precise mechanism is not known. Since body compositional change inevitably accompanies body weight change, we decided to study the possible relationship between respiratory muscle strength and body composition in patients with COPD. We studied respiratory muscle strength, pulmonary function, and body composition in 24 Japanese male patients with COPD. Patients were divided into two groups according to their body weight (group A, body weight lower than 80% of ideal body weight vs group B, 80% or more) and a comparison was made together with age-matched controls (group C). Maximal inspiratory mouth pressure (PImax) and maximal expiratory mouth pressure (PEmax) were measured by a previously reported method. Body compositional analysis was performed using dual energy x-ray absorptiometry (DXA; Norland XR26). It showed significantly lower fat body mass (FAT), FAT/body weight%, and lean body mass (LEAN) in group A than those in group B. The PImax in group A was significantly lower than that in group B and C (44.2 +/- 13.8, 76.4 +/- 29.9, and 88.6 +/- 18.1 cm H2O, respectively). PEmax in group A was also significantly lower than that in group B and group C (61.9 +/- 20.1, 86.7 +/- 26.8, and 90.4 +/- 17.6 cm H2O, respectively). Both PImax and PEmax were significantly correlated with LEAN (r = 0.656, r = 0.591, p < 0.01, respectively) in patients with COPD. These results show that respiratory muscle strength is closely associated with body weight and lean body mass in patients with COPD. The present approach to compare respiratory muscle strength with lean body mass should be useful for studying the mechanism of respiratory muscle weakness in patients with COPD.

Establishment of primary epithelial cell culture from elutriated rat gastric mucosal cells

Proliferating cells in the gastric mucosal epithelium were successfully enriched by counterflow elutriation in a medium-sized cell fraction. When inoculated on culture plates coated with E-C-L cell attachment matrix, these cells differentiated into mucus-producing cells after reaching confluence. Northern blot analysis did not detect any transcript of the proton pump, histidine decarboxylase, somatostatin, or pepsinogen I, indicating the absence of parietal, ECL, D, and chief cells in the confluent monolayer. These mucus-producing cell monolayers that respond to various growth factors may be a suitable model with which to investigate the function of gastric mucus cells in vitro.

Signal intensity characteristics of mediastinal cystic masses on T1-weighted MRI

OBJECTIVE

We evaluated the intracystic MR signal intensity of mediastinal cystic masses to identify characteristic intensity patterns according to histologic type.

MATERIALS AND METHODS

Magnetic resonance imaging was performed on 26 cystic mediastinal masses consisting of 8 thymic cysts, 5 bronchogenic cysts, 4 pericardial cysts, 5 cystic teratomas, and 4 cystic neurogenic tumors. Signal intensity ratios of each cyst to muscle were calculated on T1-weighted imaging. Surgical records were reviewed to document the presence of intracystic hemorrhage. Chemical analysis of intracystic fluid was performed in three cases.

RESULTS

Bronchogenic cysts, cystic teratomas, and cystic neurogenic tumors had relatively high levels of signal intensities. Each pericardial cyst had a lower signal intensity than muscle. The signal intensities of thymic cysts were variable. Intracystic hemorrhage was present in 1 bronchogenic cyst, 2 cystic neurogenic tumors, 4 cystic teratomas, and 3 thymic cysts. No hemorrhage was found in any of the pericardial cysts. Sebaceous fluid was present in 1 cystic teratoma.

CONCLUSION

The varying intensities of different cysts were considered to reflect the nature of the intracystic fluid. Since the nature of the fluid can reflect the histology to some extent, T1-weighted MRI will help to differentiate cystic mediastinal masses.

[Bone mineral content in patients with bronchial asthma]

To study the factors related to bone mineral content (BMC) in patients with bronchial asthma (BA), we measured BMC of the whole body, bone mineral density (BMD) in the second, third, and fourth lumbar vertebrae (by dual energy X-ray absorptiometry, DXA XR-26, Norland), and pulmonary function in patients with BA. Subjects were 103 patients with BA and 194 age-matched normal controls. There was no significant difference in BMC or BMD between patients with BA and controls. In patients with BA, there was no significant difference in BMC or BMD between those who were taking steroids and those who were not. BMC and BMD were significantly correlated with age, body weight, VC, %VC, and FEV1, but not with the duration of steroid administration or the total steroid dose administered. These results suggest that patients with BA have normal BMC and that steroid administration does not affect bone mineral loss in such patients.

Pulmonary cryptococcal infection in an untreated patient with sarcoidosis

A 36-year-old housewife was referred to our hospital in March, 1993. Her chest X ray films showed mediastinal and bilateral hilar lymphadenopathy. She was confirmed to have pulmonary sarcoidosis. We did not administer any medications for her. Four months after the diagnosis of sarcoidosis, opacities with cavitation appeared on the chest X ray. Histologic findings of lung biopsy specimens revealed granulomas with the existence of encapsulated Cryptococci. We administered an antifungal drug, itraconazole. The opacities were greatly improved by the medication. We report focal pulmonary cryptococcal infection in an untreated patient with sarcoidosis.

Early blood-brain barrier disruption after high-dose single-fraction irradiation in rats

We studied the effect of high-dose single-fraction irradiation on the permeability of the blood-brain barrier (BBB) in rat brains. Immunohistochemistry with an antibody to serum albumin was used as a sensitive method for detecting the extravasation of endogenous serum components. Extravasation of albumin was detected as early as 1 day after irradiation with 20 or 40 Gy. Immunoreactivity reached its maximum after 3 days, gradually decreased during the following few weeks and had disappeared by day 30. Extravasation was much greater after irradiation with 80 Gy and continued to increase during the whole period of the experiment (6 days). Disruption of BBB this early after irradiation has not been previously documented. The time course of observed serum albumin extravasation, however, agrees well with the previous ultrastructural evidence for increased BBB permeability after irradiation with 27 Gy in monkey brains. This transient impairment of BBB may contribute to the reversible neurological symptoms after radiosurgery. It may also allow drugs that normally not pass the BBB to do so and thus disperse in the brain when administered at this time.

Idiopathic chronic eosinophilic pneumonia associated with noncaseating epithelioid granulomas

A 34 year old Japanese woman was referred to our university hospital due to pulmonary opacities and bilateral hilar lymphadenopathy on chest X-ray. She also had uveitis, erythematous skin nodules, and oral and genital ulcers. Laboratory data showed eosinophilia in the circulation and bronchoalveolar lavage fluid. Histological study revealed massive eosinophilic infiltration and noncaseating epithelioid granulomas in the lung and mediastinal lymph node, without evidence of vasculitis. Pulmonary opacities, lymphadenopathy, and blood eosinophilia promptly improved with corticosteroid therapy. In this patient, idiopathic chronic eosinophilic pneumonia overlapped with features of sarcoidosis and Behçet's disease.

Intramuscular myxoma with fibrous dysplasia: a report of two cases with a review of the literature

Two cases are reported of a rare association of intramuscular myxoma with fibrous dysplasia in a 70 and 40 year old Japanese woman, respectively. One of them had a solitary intramuscular myxoma, and the other patient suffered from two intramuscular tumors that had been initially misdiagnosed as myxoid liposarcoma. Only 24 cases of this kind of association have been recorded in the literature. This association should be taken into consideration to avoid inappropriate treatment, when cases of myxoid soft tissue tumor with a bone lesion are encountered.

Effect of acoustic overstimulation on the hydropic ear

The effect of acoustic overstimulation (2 kHz pure tone) on the compound action potential (CAP) threshold was investigated at frequencies ranging from 2 to 16 kHz using albino guinea pigs, both normal and with experimentally induced endolymphatic hydrops. The hydropic ears were less susceptible to acoustic overstimulation than the normal ears. As the CAP threshold was raised, the frequency exhibiting the greatest CAP threshold shift increased in both animal groups. The tendency was more noticeable in the hydropic ears than in the normal ears. These results are discussed from the aspect of cochlear hydrodynamics.

CT and MRI manifestations of primary pulmonary plasmacytoma

Primary pulmonary plasmacytoma (PPP) is rare and its radiographic appearances have been seldom described. We report on a patient with PPP presenting with a hilar mass on chest radiograph. The diagnosis was confirmed by immunohistochemical study of the resected specimen. The computed tomographic and magnetic resonance imaging findings are presented.

Distortion-product otoacoustic emissions in experimentally induced hydropic ears

The postoperative changes of distortion-product otoacoustic emissions (DPOAEs) and cochlear potentials were examined using 15 albino guinea pigs in which endolymphatic hydrops was induced by obliterating the endolymphatic sac. DPOAEs (geometric mean: 4,6 and 8 kHz) were measured once before and every week after surgery. At the 2nd (n = 5), 4th (n = 5) and 12th (n = 5) postoperative weeks, endocochlear potential (EP) and compound action potential (CAP) were measured. Although the reduction in DPOAEs at 8 kHz was first detected at the 12th week, the amplitude of DPOAEs at 4 and 6 kHz was already reduced at the first week and decreased gradually thereafter. In contrast to these results, the CAP threshold was not elevated at the 2nd week and a slight increase was first detected at the 4th week. The results obtained in the present study suggest that DPOAEs are more sensitive than CAP in detecting the presence of hydrops.

Efficacy of lansoprazole and amoxicillin in eradicating Helicobacter pylori: evaluation using 13C-UBT and Monoclonal H. pylori antibody testing

Combination therapy with lansoprazole (LPZ) and amoxicillin (AMPC) was administered to eradicate Helicobacter pylori. Changes in eradication rates were monitored and serum antibody titers, levels of pepsinogens I and II (PI and PII), and gastrin were measured. The 40 subjects were divided into two groups: one group received LPZ 30 mg alone, and the other received LPZ 30 mg and AMPC 1,500 mg concomitantly. AMPC was administered for 2 weeks before completion of LPZ treatment. Maintenance therapy was cimetidine 400 mg. The presence of H. pylori was evaluated using the urea breath test (UBT). The clearance rate was 12.5% and the eradication rate was 0% in the LPZ group, and the corresponding rates in the LPZ with AMPC group were 41.6 and 25.0%, respectively. Serum monoclonal H. pylori antibody titers decreased in patients in whom bacterial eradication had been achieved. Serum PI was significantly reduced in those patients in whom eradication had been achieved. Serum PII and gastrin levels also tended to decrease in patients in whom eradication had been achieved, but no such changes were observed in the other patients. Further research into drug treatment and evaluation methods for bacterial eradication is required.

Gastrin receptor genes are expressed in gastric parietal and enterochromaffin-like cells of Mastomys natalensis

Although gastric enterochromaffin-like (ECL) carcinoid tumors are known to develop in patients with long-standing hypergastrinemia, the expression of the gastrin receptor gene in ECL cells has not yet been demonstrated. Therefore, this study was designed to examine gastrin receptor gene expression in ECL cells. Mastomys gastric mucosal cells isolated by enzyme dispersion were separated into 10 fractions (F1-10) by centrifugal elutriation. Each fraction was examined histologically to determine whether they contained ECL and/or parietal cells and Northern blot analysis was used to confirm the presence of histidine decarboxylase and H+, K(+)-ATPase gene expression. ECL cells were found only in fractions 1 and 2, whereas parietal cells were detected in fractions 6-10. Gastrin receptor gene expression was demonstrated in both parietal cell-rich and ECL cell-rich fractions. In addition, the gastrin receptor cDNA sequences obtained from the two of the fractions (F1 and 8) were identical. These results suggest that gastrin receptor genes are expressed in ECL cells as well as in parietal cells and that these receptors are identical.

[Regulation of G protein-coupled receptor kinase activity]

Recent progress on the activation of G protein-coupled receptor kinases is reviewed. beta-Adrenergic receptor kinase (beta ARK) is activated by G protein beta gamma -subunits, which interact with the carboxyl terminal portion of beta ARK. Muscarinic receptor m2-subtypes are phosphorylated by beta ARK1 in the central part of the third intracellular loop (I3). Phosphorylation of I3-GST fusion protein by beta ARK1 is synergistically stimulated by the beta gamma -subunits and mastoparan or a peptide corresponding to portions adjacent to the transmembrane segments of m2-receptors or by beta gamma -subunits and the agonist-bound I3-deleted m2 variant. These results indicate that agonist-bound receptors serve as both substrates and activators of beta ARK.

[Bronchial hyperresponsiveness before and after percutaneous transluminal mitral commissurotomy in patients with mitral stenosis]

To study the effects of percutaneous transluminal mitral commissurotomy (PTMC) on bronchial responsiveness to inhaled methacholine in patients with mitral valve stenosis (MS), methacholine inhalation tests and pulmonary function tests were done in 10 patients with MS before and one week after PTMC. The mean log cumulative dose producing a 35% decrease in respiratory conductance (PD35Grs) was significantly higher after PTMC in nine patients in whom PTMC was successful (p < 0.05). There were no significant changes in the results of pulmonary function tests after PTMC. One patient had severe mitral regurgitation after PTMC, and a decrease in PD35Grs. Six of the other nine patients in whom PTMC was successful continued to be hyperresponsive to inhaled methacholine. These data show that bronchial hyperresponsiveness in patients with MS is less severe after PTMC, concomitant with the relief of pulmonary congestion, and they suggest that the remaining bronchial hyperresponsiveness is responsible for peripheral airway narrowing with organic remodeling.

Gastrin receptor gene expression in several human carcinomas

Gastrin has been shown to enhance the growth of various human tumors. The present study was designed to examine the gastrin receptor gene expression in various human carcinoma cell lines and in surgically resected carcinoma tissues. By Northern blot analysis, gastrin receptor mRNA was detected in 3 out of 7 small cell lung carcinoma cell lines. Gastrin receptor mRNA was also expressed in one out of 8 colon carcinoma cell lines and 2 out of 10 colon carcinoma tissues. Moreover, one of two small cell carcinoma cell lines of the stomach clearly expressed gastrin receptor mRNA. However, none of the gastric adenocarcinoma cell lines or surgically resected gastric adenocarcinomas tested had any detectable expression of gastrin receptor gene. These findings may suggest a role of gastrin receptor in the growth and differentiation of certain human carcinomas.

[123I-IMP clearance of the lung in pneumoconiosis]

We studied 123I-IMP lung clearance on 10 cases of pneumoconiosis and compared it with the data of 5 non-smoking young adults. After the venous injection of 111 MBq of 123I-IMP we collected the lung dynamic data using 1 frames/10 sec for 10 minutes and 1 frame/min for following 40 minutes. The time activity curve after the injection of 123I-IMP was obtained as follows: C(t) = A1e-k1t divided by A2e-k2t (k1, k2: slopes of the exponential component at the early and delayed phase). The 123I-IMP clearance was delayed in the patients group especially on the early phase and the k1 was lower than that of the normal group. Our results indicate that the pulmonary blood flow of the patients with pneumoconiosis decreased because of the advanced fibrotic change. This dynamic analysis may prove useful for the evaluation of the pneumoconiosis objectively and quantitatively.

[A case of bronchiolitis obliterans organizing pneumonia: diagnostic utility of bronchoalveolar lavage and CT scan]

A 54-year-old female was admitted to our hospital because of abnormal shadows on chest X-ray at annual checkup. She complained of dyspnea on exertion. Chest X-ray findings showed an increase in density at the bilateral lower lung fields and unclearness of the silhouette of the heart and the diaphragm. CT scan findings revealed irregular opacities of various density with many small cystic changes and air bronchograms and air bronchiolograms. The pulmonary function test showed restrictive ventilatory disturbance and reduced diffusing capacity. BALF findings revealed an increase in the total cell count, an increase in the percentage of lymphocytes and a decrease in the OKT4+/OKT8+ ratio. TBLB specimen showed infiltration of mononuclear cells in alveolar septa and organizing exudate in alveolar ducts. These findings suggested a diagnosis of BOOP rather than IPF, and an open lung biopsy was performed. Open lung biopsy specimen showed obstructive bronchiolitis with polypoid granulation tissue and thickening of alveolar septa with infiltration of mononuclear cells, and she was diagnosed as having BOOP. She responded well to corticosteroid and is free from any abnormalities on chest X-ray, CT scan and pulmonary function test at present. Analysis of BALF and CT scan findings are useful for the differential diagnosis of BOOP and IPF.

Regulation of interleukin-1 receptors and hypothalamic-pituitary-adrenal axis by lipopolysaccharide treatment in the mouse

We measured iodine-125-labeled recombinant human interleukin-1 alpha (125I-IL-1 alpha) binding in the hippocampus, pituitary, liver, spleen and testis, and plasma adrenocorticotropic hormone (ACTH) and corticosterone levels after i.p. injection of various dose and treatment regimens of the bacterial endotoxin, lipopolysaccharide (LPS). Plasma ACTH and corticosterone levels were significantly increased at 2 h after acute administration of LPS (60 or 300 micrograms/mouse). 125I-IL-1 alpha binding in all peripheral tissues examined was significantly and comparably decreased at 2 h after a single injection of 30 micrograms or 300 micrograms LPS/mouse. On the other hand, 125I-IL-1 alpha binding in hippocampus was significantly decreased only after high dose administration of LPS (300 micrograms/mouse). In order to evaluate if activation of IL-1 in brain resulting in the observed decrease in 125I-IL-1 alpha binding may require more sustained exposure to endotoxin, we compared the effects of a single injection (60 micrograms/mouse) and two injections of LPS (30 micrograms/mouse each at 0 and 12 h). A single injection of LPS (60 micrograms/mouse) decreased 125I-IL-1 alpha binding in the testis but not in the hippocampus, while two LPS injections (30 micrograms/mouse each at 0 and 12 h) caused dramatic reductions in 125I-IL-1 alpha binding in both the hippocampus and testis.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of A2a adenosine receptor mRNA expression by agonists and forskolin in PC12 cells

Modulation of A2a adenosine receptor (A2aAR) expression by adenosine agonists was studied in cultured PC12 cell lines. Exposure of A2aAR agonists such as 5'-N-ethylcarboxamidoadenosine (NECA) or CGS-21680 caused a transient increase followed by a decrease of A2aAR mRNA in PC12 cells in 10 h. This was followed by a gradual recovery to control levels by approximately 24 h. These changes were blocked by an adenosine receptor antagonist, xanthine amine congener. Forskolin also induced similar changes in the level of A2aAR mRNA. In addition, A2aAR numbers of PC12 cell membranes were significantly decreased during the NECA-exposure. These results suggest that A2aAR gene expression in PC12 cells is regulated by activation of A2aAR via a mechanism involving the second messenger, cAMP.

[Combined radiotherapy and hyperthermia for Pancoast tumor]

Thirteen patients with Pancoast tumor were treated with combined radiotherapy and hyperthermia from April 1987 to December 1992. Radiotherapy was performed using 10 MV X-rays, and all patients received a total dosage of 40-118 Gy with conventional fractionation. Hyperthermia was performed once or twice a week within 30 minutes after each irradiation, using 8 MHz RF capacitive heating equipment (Thermotron RF-8). Partial response, defined as 50% or more regression of the tumor, was observed in 7/13 (54%) patients, and the median survival time was 25.2 months. Results of 14 patients treated with irradiation alone from July 1980 to December 1992 were also evaluated, and were used as a historical control. The partial response was 4/14 (29%) and the median survival time was 7.3 months. Radiotherapy combined with hyperthermia is an effective modality for treating Pancoast tumors.

Complete regression of anaplastic astrocytoma by intravenous tumor necrosis factor-alpha (TNF alpha) after recurrence: a case report

A 61-year-old male patient had a recurrence of anaplastic astrocytoma after initial chemoradiotherapy. After histologic confirmation of the recurrent tumor, he was treated with intravenous administration of human natural tumor necrosis factor-alpha (TNF alpha). Morphometric analysis of the tumor volumes demonstrated that the tumor continued to regress for 8 months during the course of intravenous TNF alpha therapy, and finally disappeared (total dose of intravenous TNF alpha, 785,000 JRU). The regression of tumor paralleled the neurologic improvement. He has had no signs of recurrence for 2 years. The present experience indicates that at least a certain population of malignant gliomas can be successfully treated by a systemic administration of TNF alpha without a major adverse effect.

Sarcoidosis with hypercalcemia--successful treatment of renal insufficiency and renal calcification with prednisolone

A case of muscular sarcoidosis accompanied by severe hypercalcemia (serum calcium 15.5 mg/dl), renal insufficiency and renal calcification is reported. Sarcoid granulomas were found in the biopsy specimens of the lung and the muscle. The administration of prednisolone effectively improved not only muscle weakness but also hypercalcemia, renal insufficiency and renal calcification. This is a rare case of sarcoidosis in which renal calcification remitted after treatment with prednisolone. It is thus suggested that prednisolone treatment should be considered not only for hypercalcemia, but also for renal insufficiency caused by renal calcification in patients with sarcoidosis.

Distribution of mRNA for CCK-B receptor in the brain of Mastomys natalensis: abundant expression in telencephalic neurons

The distribution of cholecystokinin B (CCK-B) receptors in the Mastomys brain was studied using Northern blot analysis and in situ hybridization technique. By Northern blot analysis using 32P-labeled cDNA probe, the cortex had the highest hybridization signal of CCK-B receptor mRNA in the brain. The olfactory bulb and hippocampus showed a moderate level of signals. In situ hybridization using 35S-labeled cRNA probes revealed a wide and region-specific distribution of CCK-B receptor mRNA in the telencephalon. Throughout the cerebral cortex, labeled cells were found in all layers, with higher intensities in layers II, V and VI. Pyramidal cells of the layer II of the piriform cortex showed the highest level of signals in the brain. In the hippocampus, most of the pyramidal cells of the Ammon's horn were labeled, although labeled cells were not detected in other layers. Distinct signals were also detected in the various amygdaloid nuclei, caudate-putamen, reticular thalamic nucleus, hypothalamic ventromedial nucleus and inferior colliculus. This distribution pattern may further support the prominent existence of CCK-B receptors in the brain particularly in the telencephalon.

Location of agonist-dependent-phosphorylation sites in the third intracellular loop of muscarinic acetylcholine receptors (m2 subtype)

Muscarinic acetylcholine receptors (mAChR, human m2 subtype) expressed in Sf9 (Spodoptera frugiperda) cells using the baculovirus system were purified and subjected to phosphorylation by a mAChR kinase, which was partially purified from porcine cerebrum. Two bands with apparent molecular masses of 59 kDa and 39 kDa as determined by SDS/PAGE were found to be phosphorylated in an agonist-dependent manner. Both bands were labeled by the irreversible muscarinic ligand [3H]propylbenzilylcholine mustard. Molecular masses of the [32P]phosphorylated or [3H]propylbenzilylcholine-mustard-labeled bands decreased following treatment with N-glycanase. The 59-kDa and 39-kDa bands were converted to 52-kDa and 32-kDa bands, respectively, indicating that both the 59-kDa and 39-kDa bands contain the amino-terminal region where glycosylation sites are present. The ratio of incorporated [32P]phosphate and bound [3H]propylbenzilylcholine mustard was essentially the same for the 59-kDa and 39-kDa bands, indicating that all the phosphorylation sites reside in the sequence of 39 kDa from the amino-terminal region. The amounts of incorporated [32P]phosphate were estimated to be 10-11/receptor, with 7-8 serine and 3-4 threonine, but no phosphorylated tyrosine residues. Further treatment of [32P]phosphorylated or [3H]propylbenzilylcholine-mustard-labeled receptors with V8 protease indicated that the phosphorylation sites were not present in 30-kDa amino-terminal segment. These results indicate that the phosphorylation sites are localized in the range 30-39 kDa from the amino terminus, which consists of primarily the central part of the third intracellular loop. Consistent with this conclusion, a fusion protein containing glutathione S-transferase linked to a peptide corresponding to residues 227-324 of the central part of the third intracellular loop was found to be phosphorylated by the mAChR kinase in a heparin-sensitive manner.

Computed tomographic findings of invasive transitional cell carcinoma in the kidney

CT findings of 10 cases of transitional cell carcinoma with renal parenchymal involvement were reviewed. CT showed a low-density mass with varying degrees of renal parenchymal involvement. Intrarenal transitional cell carcinomas were characterized by preserved renal contour with abnormalities of the collecting system such as obliteration, entrapment in the tumor, dilatation, and intraluminal mass. Obliteration of the renal sinus fat and poorly defined tumor margin were other characteristic CT features. This study indicated that CT is useful for differentiating transitional cell carcinomas with renal parenchymal involvement from renal cell carcinomas.

[Effects of long-term endurance training on left ventricular dimensions and function in female distance runners]

Ultrasoundcardiogram (UCG) was measured to evaluate the effects of 2 years of endurance training on left ventricular dimensions and function in 3 female collegiate runners (mean age 19.7 years). All subjects had had an experience in endurance training as athletes and underwent the endurance training at the college for two years. Training consisted mainly of about 2 hours of running, 3 to 4 days a week. Training effects were found as measured by a 5000m-run pretraining (mean 19: 40.3 min) and post-training (mean 18: 49.3 min). The average increase in maximal oxygen uptake (VO2max/kg) after training was 9.4% (P < 0.05). UCG's dimensional variables such as LVDd, LVPWT and IVST in the post-training period did not reveal any increase. However, LVDs as a cardiac dimension showed a tendency to decrease, and functional variables such as SV, EF, FS showed a tendency to increase. This functional improvement appeared to be due to a decrease in LVDs. From these results, it is likely that the endurance training prior to this study might have helped an effective adaptation in their cardiac dimensions. Thus, we suggest that prior to this study cardiac dimensions had extended and enlarged to a certain extent, and then cardiac function might be improved as the subsequent physiological phenomenon.

Gastrin/CCK-B receptors on brain, gastric parietal cells and ECL carcinoid tumor of Mastomys natalensis

Cholecystokinin (CCK)-8 and human gastrin I (gastrin) were found to be almost equipotent in displacing the specific binding of not only 125I-CCK-8 but also 125I-gastrin to both ECL carcinoid tumor and parietal cell membranes of Mastomys natalensis. These binding specificities of the native gastrin receptors for CCK-8 and gastrin were identical to that of the cloned gastrin receptor from the ECL carcinoid tumor expressed on CHO-K1 cells. In contrast, CCK-8 was approximately 10-20 times as potent as gastrin in inhibiting the binding of the two radioligands to the Mastomys brain membrane. However, the nucleotide sequences of RT-PCR products of mRNAs extracted from not only the isolated parietal cells but also the brain were identical to that of the gastrin receptor cDNA from the ECL carcinoid tumor. Thus, the gastrin receptors on the parietal cells and the brain appear to be encoded by the same gene as those on the ECL carcinoid tumor in Mastomys. The reason for the difference in binding characteristics between the cloned gastrin receptor and the native gastrin/CCK-B receptor in the brain remains to be elucidated.

[Bone mineral loss in patients with chronic obstructive pulmonary disease]

Body weight loss is often observed in patients with chronic obstructive pulmonary disease (COPD). Bone mineral loss has also been reported in COPD, but the mechanisms are not well determined. To elucidate what factors influence on bone mineral content in COPD patients, we measured bone mineral content (BMC) by dual energy X-ray absorptiometry (DXA) (XR-26, Norland), pulmonary function, and ten minute walk distance (TMD) in Japanese elderly male patients with COPD. The subjects were 21 male patients with COPD (72.6 +/- 9.5 years) and 18 age-matched male normal individuals (66.5 +/- 9.5 years). COPD patients showed significantly (p < 0.05) lower BMC (1.82 +/- 0.33, 2.27 +/- 0.35 kg, respectively) compared with age-matched controls. BMC was significantly correlated with body weight and TMD (r = 0.71, r = 0.51, respectively). These results demonstrate that lower body weight and decreased exercise capacity account for the significantly lower bone mineral content of our COPD patients and that COPD patients with body weight loss may be at high risk for osteoporotic fracture.

Alteration of lipoprotein(a) concentration with glycemic control in non-insulin-dependent diabetic subjects without diabetic complications

Recently, a high plasma level of lipoprotein(a) [LP(a)] has been considered an independent risk factor for atherosclerosis and its sequelae, particularly myocardial infarction. Patients with non-insulin-dependent diabetes mellitus (NIDDM) have an increased mortality rate from cardiovascular and cerebrovascular disease. Therefore, plasma concentrations of Lp(a) were determined and the relationship between fasting plasma Lp(a) level and diabetic control was investigated in NIDDM patients without any diabetic complications. Fasting plasma Lp(a) levels were measured using enzyme-linked immunosorbent assay kits [Terumo Medical Corp, Elkton, MD, Lp(a)] in 61 NIDDM subjects (30 men aged 56 +/- 2.0 years, 31 women aged 53 +/- 2.1 years [mean +/- SEM]) who were without any diabetic macroangiopathy and microangiopathy such as retinopathy, nephropathy, and neuropathy and in 56 healthy age- and sex-matched controls. Plasma Lp(a) levels were significantly higher in the diabetic group than in the control group (23.5 +/- 2.5 v 11.7 +/- 1.4 mg/dL [mean +/- SEM], P < .001). There was no significant correlation between log-transformed plasma Lp(a) levels and other factors such as age, sex, body mass index (BMI), blood pressure, duration of diabetes, fasting plasma glucose (FPG) level, glycosylated hemoglobin (HbA1C) level, and plasma lipid levels except for low-density lipoprotein cholesterol (LDL-C) levels in diabetic patients. A significant positive correlation was noted in diabetic patients between the changes of log Lp(a) and HbA1C levels after a 3-month follow-up period (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Human neuroblastoma cells express alpha and beta platelet-derived growth factor receptors coupling with neurotrophic and chemotactic signaling

Both platelet-derived growth factor (PDGF) A- and B-chains are expressed in mammalian neurons, but their precise roles still remain to be clarified. In the present studies, we examined the expression of two PDGF receptor genes in human tumor cell lines derived from neural crest. The expression of alpha and/or beta PDGF receptors was detected in a wide variety of neural crest-derived human tumor cell lines such as neuroblastoma, primitive neuroectodermal tumor, and Ewing's sarcoma by RNA blot analysis, and confirmed by immunoblot analysis. We have also demonstrated that PDGF receptors on the human neuroblastoma cell lines were biologically functional. Accordingly, chemotactic and mitogenic activities were induced by either PDGF-AA or PDGF-BB in serum-free medium. PDGF isoforms as well as nerve growth factor induced morphological changes showing neuronal cell maturation. Moreover, PDGF coordinately increased the levels of the transcript of the midsize neurofilament gene. The neuroblastoma cell lines also expressed the transcripts of PDGF A- and B-chains. These findings suggest that PDGF isoforms are involved not only in the promotion of the neuroblastoma cell growth, but also in neuronal cell migration, growth, and differentiation in human brain development.

Functional characterization of a human brain cholecystokinin-B receptor. A trophic effect of cholecystokinin and gastrin

We have cloned a human brain cholecystokinin (CCK)-B receptor cDNA and characterized its function by introducing it into Chinese hamster ovary (CHO) cells. The deduced amino acid sequence was highly conserved as compared with those of the gastrin receptors in Mastomys enterochromaffin-like cells (90%) and canine parietal cells (89%). Human brain CCK-B receptors possessed slightly but significantly higher affinities for CCK-8 than for gastrin I, while both ligands bound equally to Mastomys enterochromaffin-like cell-derived gastrin receptors. Both CCK-8 and gastrin I markedly augmented phosphoinositide hydrolysis and cytosolic free calcium levels in the CHO transfectants, indicating that the cloned CCK-B receptor could functionally couple with intracellular signaling molecules. Moreover, CCK-8 and gastrin I dose-dependently increased [3H]thymidine incorporation of the CHO transfectants in serum-free medium and promoted cell growth. The CCK-B receptor mRNA was abundantly expressed in particular areas of the human brain and stomach, such as the cerebral cortex and mucosa of the gastric fundus. This is the first demonstration of trophic effects of CCK and gastrin through the normal human brain CCK-B receptor. The availability of this receptor cDNA will help to clarify the precise role of CCK in the central nervous system as well as digestive organs.

[A case of extraskeletal Ewing's sarcoma of the chest wall]

A 22-year-old woman was admitted to our hospital complaining of high fever, dyspnea and wheeze. Chest X-ray film and CT scan showed a huge mass lesion in the right chest. Histological findings of specimens obtained by both needle biopsy and surgery showed necrotic tissue. She died of rapidly progressive pulmonary metastasis three months after surgery, and at autopsy, the tumor was diagnosed as extraskeletal Ewing's sarcoma originating from the chest wall.

Appearance of pulmonary metastases on high-resolution CT scans: comparison with histopathologic findings from autopsy specimens

OBJECTIVE

The purpose of this study was to compare the appearance of pulmonary metastases on high-resolution CT scans with the histopathologic findings in lung specimens obtained at autopsy. The factors considered were the appearance of the margins of pulmonary metastases, the location of relatively small nodules in relation to the secondary pulmonary lobules, and the detectability of lymphangitic spread of tumors and intravascular tumor emboli on high-resolution CT scans.

MATERIALS AND METHODS

We studied 14 lungs obtained at autopsy that contained metastatic lesions. We used both microscopy and high-resolution CT to evaluate 87 metastatic nodules 5-20 mm in diameter for the appearance of their margins and to determine the location of 43 nodules that were less than 5 mm in diameter relative to the secondary pulmonary lobules. The detection of histologically confirmed intravascular tumor emboli and lymphangitic spread by high-resolution CT also was evaluated.

RESULTS

On high-resolution CT scans, 38% of the nodules had well-defined, smooth margins, 16% had well-defined, irregular margins, 16% had poorly defined, smooth margins, and 30% had poorly defined, irregular margins. The well-defined, smooth margins on high-resolution CT scans corresponded histologically to an expanding type and to an alveolar space-filling type; the poorly defined margins, to an alveolar cell type; and the irregular margins, to an interstitial proliferative type. Some correlation was found between the histologic type of primary tumor and the CT appearance of the lesion's margins. As for small nodules, 12% were connected with the central bronchovascular bundle, 28% were on the perilobular structures, and 60% were apparently not in contact with these structures. Only two of the 11 lungs with histopathologically confirmed lymphangitic tumor spread and none of the tumor emboli were detected on high-resolution CT scans.

CONCLUSION

The characteristics of the margins of metastatic pulmonary nodules noted on histopathologic examination correlated well with their high-resolution CT findings. Microscopic intravascular tumor emboli and lymphangitic tumor spread were difficult to detect on high-resolution CT scans, indicating a limitation of high-resolution CT in the diagnosis of pulmonary metastatic disease.

[Serum superoxide dismutase (SOD) activity in diabetes mellitus]

The serum superoxide dismutase (s-SOD) activities in patients with diabetes mellitus (DM) were assayed in order to evaluate its usefulness for monitoring of DM and also evaluate the relation between s-SOD activities and microangiopathies (nephropathy, neuropathy and retinopathy). As results followings were obtained; 1) s-SOD activities in DM patients were significantly higher than those in healthy controls (12.56 +/- 7.73 vs 10.51 +/- 1.69, p < 0.01). 2) There was no relations between s-SOD activities and FBS-, fructosamine- and HbA1-levels, respectively. 3) Among DM patients s-SOD activities were significantly higher in patients with microangiopathy than those in patients without microangiopathy (14.18 +/- 11.00 vs 11.24 +/- 3.13, p < 0.01). 4) Among DM patients with microangiopathy higher s-SOD activities tended to be observed in patients with triopathy such as nephropathy, neuropathy and retinopathy than in those with one or two microangiopathic complications. 5) Among DM patients with nephropathy the correlation was present between s-SOD activities and levels of creatinine. These results suggest that the assay of s-SOD activity is not useful for the monitoring of DM, however, it is suggested that the high s-SOD activity reflects the microangiopathic complications, particularly nephropathy.

Development of an antiserum to rat-brain A1 adenosine receptor: application for immunological and structural comparison of A1 adenosine receptors from various tissues and species

An antiserum was developed in a rabbit against rat-brain A1 adenosine receptor. This antiserum recognized the denatured form of the purified rat-brain A1 adenosine receptor in immunoblot analysis and the native form of the receptor in the immunoprecipitation analysis. Immunoblot analysis of unpurified or purified adenosine receptor preparations from rat-brain membranes revealed a major immunoreactive band at a position of molecular mass of approx. 35 kDa, which corresponds to the position of purified rat-brain A1 adenosine receptor. Although A1 adenosine receptors from other rat tissues such as testis and adipocyte were also found to be immunoreactive with this antiserum by immunoblot analysis, purified human-brain A1 adenosine receptors showed a poor reactivity with this antibody. The order of the relative immunoreactivity of these A1 adenosine receptors with the antiserum was found to be brain > adipocyte > or = testis. Moreover, the immunoreactivity of these receptors significantly increased after these receptor preparations were deglycosylated by endoglycosidase F. After the deglycosylation, no significant differences in both the immunoreactivity and molecular mass among these receptor preparations were found on the immunoblot. These results suggest that the differences in the molecular mass or immunoreactivity among the A1 adenosine receptor preparations from three rat tissues were mainly due to the difference of sugar moiety present in each receptor molecule. These data are the first to provide analyses of immunological characteristics of A1 adenosine receptors from different tissues and species.

Assessment of Chlamydia trachomatis-specific IgA and IgG serum antibodies in genitourinary Chlamydia trachomatis infection--comparative study between HITAZYME and IPAzyme

We assessed the C. trachomatis antibody assay kit HITAZYME (Hitachi Chemical Co., Ltd.) using clinical specimens. This kit is based on an enzyme immunoassay (EIA) which utilized purified Chlamydia trachomatis outer membrane antigen as the solid phase antigen. Twenty-nine untreated male urethritis patients, 816 pregnant housewives, 188 cervicitis patients, and 76 pelvic inflammatory disease patients were tested. Agreement between the HITAZYME test and antigen detection in infected area was assessed, and a comparison was made with IPAzyme (a commercially available indirect immunoperoxidase assay kit). 1) Summary of HITAZYME and IPAzyme IgA: Agreement between the two assays was relatively good, i.e., 82.6% (916/1109). However, 5.5% (61/1109) were HITAZYME (-), IPAzyme (+), and 11.9% (132/1109) were HITAZYME (+), IPAzyme (-). Thus, in quite a few cases the results did not agree. IgG: Agreement between the two assays was 73.7% (817/1109). Agreement was relatively low, 24.4% (271/1109) were HITAZYME (-), IPAzyme (+). 2) In the cases of disagreement, more specific Western blot analysis was performed to check the reactivity of the anti-C. trachomatis antibody. When IgA was used, agreement between HITAZYME and Western blot analysis was 69.6% (16/23), and agreement between IPAzyme and Western blot analysis was 30.4% (7/23), whereas when IgG was used, agreement between HITAZYME and Western blot analysis was 80.0% (12/15), and agreement between IPAzyme and Western blot analysis was 20.0% (3/15). There was significantly greater agreement with HITAZYME than with IPAzyme. In other words, HITAZYME had greater specificity when reacted with C. trachomatis antigen than IPAzyme. 3) The IgA antibody-positive rate in antigen (+) cases (male urethritis: 72.7%, pregnant housewives: 65.7%, cervicitis: 70.3%, pelvic inflammatory disease: 70.0%) was significantly (p < 0.01) higher than in antigen (-) cases (male urethritis: 16.7%, pregnant housewives: 13.6%, cervicitis: 22.6%, pelvic inflammatory disease: 30.4%). Therefore, IgA antibody can serve as a suitable indicator for active infection. 4) The IgG antibody-positive rate in antigen (-) female cases was 15.5% using HITAZYME and significantly (p < 0.01) lower than with IPAzyme. HITAZYME had greater specificity than IPAzyme. In conclusion, HITAZYME has relatively good sensitivity and specificity. Moreover, since it is an EIA assay, it allows objective evaluation of results. It permits processing of a large number of specimens because it is easy to perform. Thus, HITAZYME is a superior antibody assay for C. trachomatis. It can be used when antigen tests are difficult to perform. It is strongly anticipated that HITAZYME will be able to be used clinically as a screening test.

MRI of bronchogenic cysts

The MR appearance of eight bronchogenic cysts is reported. All the cysts appeared homogeneous and were of very high signal intensity, approximating that of CSF on spin-echo T2-weighted imaging, and of relatively high intensity, between that of muscle and subcutaneous fat on T1-weighted imaging. The cysts were round or ovoid and were well demarcated. These findings are consistent with the fluid-containing properties of cysts.

[A case of spontaneous pneumothorax due to rupture of bleb infected with aspergillosis]

A 17-year-old male was diagnosed as having left spontaneous pneumothorax by chest X-ray. Chest CT scan showed a cystic shadow with a thick wall in the left apex. Thoracotomy was performed, and the bleb was resected. Histologically, aspergillus was found in the cavity and the wall of the resected bleb. In this case, we consider that focal aspergillus infection in the bleb caused spontaneous pneumothorax. In cases of spontaneous pneumothorax in which the bleb wall is thick, the bleb should be evaluated by histological and bacteriological examination. Such a case has been rarely reported in Japan.

Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects

The influence of usual multiple ingestions of dietary caffeine on oral single-dose pharmacokinetics of theophylline has been investigated in 6 healthy male subjects. The subjects consumed 2 to 7 cups of regular instant coffee during the 24 h study period. Their mean serum concentrations of caffeine varied from 1.2 to 3.1 mg/l. After their usual intake of dietary caffeine, the serum concentrations of theophylline from 3 to 24 h after administration were significantly higher than after deprivation of dietary caffeine. The apparent elimination of theophylline half-life was prolonged from 6.3 (0.61) h (mean with (SEM)) to 8.3 (0.47) h (32% increase, P < 0.01) and the total body clearance was reduced from 55.0 (1.31) ml.h-1.kg-1 to 42.5 (2.63) ml.h-1.kg-1 (23% decrease, P < 0.001). Saturation of theophylline metabolism and/or competition between theophylline and caffeine metabolism in addition to theophylline derived from caffeine may be the cause of the delayed elimination of theophylline. The present study has indicated that a significant reduction in theophylline metabolism may be caused by a conventional intake of dietary caffeine. In bronchodilator therapy with theophylline, therefore, the daily consumption of caffeine should be taken into consideration.

Primary low cerebrospinal fluid pressure syndrome associated with galactorrhea

A 36-year-old woman with positional headache was found to have primary low cerebrospinal fluid (CSF) pressure syndrome and galactorrhea. The CSF pressure at lumbar puncture was not measurable. Magnetic resonance imaging demonstrated that the ventricle and cerebral sulcus were narrowed and the pituitary stalk was oppressed by the brain. Hyperresponsiveness of prolactin was noted after stimulation with thyrotropin-releasing hormone. These abnormalities disappeared with normalization of CSF pressure with the treatment. Galactorrhea was apparently due to oppression of the pituitary stalk by downward movement of the brain.

Characterization of gastrin/CCK receptors on gastric carcinoid tumor membrane of Mastomys natalensis

Recently, we identified the specific binding site for gastrin on the gastric carcinoid tumor of Mastomys (Praomys) natalensis. In this study, precise characterization of the gastrin binding site on these tumors was performed. Both 125I-human gastrin I (gastrin) and 125I-CCK-8 bound specifically to the cell membrane, and Scatchard analysis revealed a high affinity binding site for each ligand with similar Kd and Bmax values. The specific binding of both 125I-gastrin and 125I-CCK-8 was displaced in a concentration-dependent manner by various related peptides with a relative potency order of CCK-8 > or = gastrin < des(SO3)CCK-8. In addition, L364,718 as well as L365,260 displaced the binding of both ligands with similar potencies. Furthermore, not only gastrin but also CCK-8 increased [Ca2+]i in these tumor cells, the action of both being inhibited by L364,718 as well as by L365,260 (10(-7) M). These results suggest that the carcinoid tumor of Mastomys possesses a high affinity gastrin/CCK binding site coupled to the increase of [Ca2+]i.

Antibodies raised against the adenosine receptor agonist, 5'-N-ethylcarboxamidoadenosine (NECA)

Antisera against the non-selective adenosine receptor agonist 5'-N-ethylcarboxamido-adenosine (NECA) have been raised by immunizing rabbits with NECA-coupled bovine serum albumin. The antisera which bind [3H]NECA with high affinity were purified by affinity chromatography using NECA-coupled Sepharose as the affinity gel without significant changes in [3H]NECA-binding properties. The order of the affinity for various adenosine receptor ligands of the purified or unpurified antisera was 5'-N-cyclopropylcarboxamidoadenosine > or = NECA > 2',5'-dideoxyadenosine > 2-chloroadenosine > theophylline > isobutylmethylxanthine > (R)-N6-phenylisopropyladenosine = N6-cyclohexyl- adenosine. This specificity was found to be similar to that of the non-receptor NECA-binding sites, which had been found in various tissues such as human placentas and mouse P815 mastocytoma cells, rather than to that of adenosine receptors. These anti-NECA antibodies will be useful as immunochemical agents in the search for endogenous ligand(s) to the non-receptor NECA-binding sites.

[A case of Down's syndrome with progressive dementia of Alzheimer type]

A rare case of Down's syndrome complicated with progressive dementia of Alzheimer type in a 41-year-old man was reported. On 123I-IMP SPECT, the patient revealed symmetrical bilateral temporo-parietal hypoperfusion. This finding seemed to support the developing dementia of Alzheimer type on the basis of clinical manifestations. 123I-IMP SPECT seemed to be useful for early diagnosis of Alzheimer-like change in a natural course of Down's syndrome.

Effects of apolipoprotein E polymorphism on plasma lipoprotein(a) levels

Effects of apolipoprotein E (apo E) genetic polymorphism on plasma lipoprotein(a) (Lp(a)) levels were investigated in 305 civil service workers (158 men and 147 women). Plasma Lp(a) levels were measured by ELISA. Apo E phenotypes were determined from plasma by isoelectric focusing, Western blotting and immunostaining, as we previously reported. A total of 305 subjects were divided into the three apo E groups; apo E2 group (n = 19 for apo E3/2 and n = 4 for apo E4/2), Apo E3/3 group (n = 224) and apo E4/3 group (n = 58). Mean levels of plasma Lp(a) were 14.2 mg/dl. Plasma Lp(a) levels were significantly lower in the apo E2 group (6.6 mg/dl) than in the apo E3/3 (15.1 mg/dl) and E4/3 (13.7 mg/dl) groups. Plasma total cholesterol (T-chol) and low density lipoprotein (LDL)-chol levels were significantly lower in the apo E2 group than in the apo E4/3 group and tended to be highest in the apo E4/3 group. A significant positive correlation was noted between plasma Lp(a) levels and plasma LDL-chol levels, indicating that the effects of apo E polymorphism on plasma Lp(a) levels were parallel to its effects on plasma LDL-chol levels. In women plasma Lp(a) levels were significantly lower in the apo E2 group than in the apo E3/3 and E4/3 groups, whereas in men plasma Lp(a) levels tended to be lower in the apo E2 group but no significant difference was noted among the three apo E groups. It is concluded that plasma Lp(a) levels are, at least in part, modulated by apo E polymorphism (particularly apo E2) and that there is a gender difference in the effects of apo E polymorphism on plasma Lp(a) levels.

Phosphorylation of muscarinic receptors: regulation by G proteins

Effects of G proteins on the phosphorylation of muscarinic receptors (mAChRs) have been examined. Cerebral but not atrial mAChRs were phosphorylated by any one of three types of protein kinase C and 4-6 mol of phosphate were incorporated per mol of mAChR, mostly in the 12-14 kDa from the carboxyterminus. Atrial mAChRs were better substrates of cAMP-dependent protein kinase than cerebral mAChRs. Phosphorylation of mAChRs by protein kinase C or cAMP-dependent protein kinase was not dependent on the presence of agonists and G proteins except that a slight inhibition by G proteins was observed probably because G proteins were also substrates of the two kinases. Agonist-dependent phosphorylation of atrial mAChRs or recombinant human mAChRs (m2 subtype) by a kinase (mAChR kinase), which is the same or very similar to beta adrenergic receptor kinase (beta ARK), was found to be regulated by the G proteins in a dual manner; stimulation by G protein beta gamma subunits and inhibition by G protein alpha beta gamma trimer. The inhibition by the G protein trimer is restored by addition of guanine nucleotides and is considered to be due to the formation of a ternary complex of agonist, mAChR and guanine nucleotide free G proteins. The stimulation by G protein beta gamma subunits was also observed for the light- or agonist-dependent phosphorylation of rhodopsin and beta AR by the mAChR kinase but not for the light-dependent phosphorylation of rhodopsin by rhodopsin kinase. The phosphorylation by beta ARK 1 was also found to be stimulated by G protein beta gamma subunits. The beta gamma subunit is considered to interact with the extra 130 amino acid residue carboxyterminal tail of beta ARK, which does not exist in rhodopsin kinase, and the interaction results in the activation of the kinase. We may assume that the G protein coupled receptor kinase is an effector of G protein beta gamma subunits and that one of the functions of beta gamma subunits is to stimulate the phosphorylation of G protein coupled receptors thereby facilitating their desensitization.