[Diagnosis and treatment of sleep apnea syndrome in Japan --comparison with other countries]

The prevalence of sleep apnea syndrome (SAS) in Japan has been reported to be about 1-2%, which is almost the same as that reported in western countries. However, an epidermiological survey of SAS recently performed by institutes participating in the Japanese Society of Sleep-Disordered Breathing showed that only 1,425 patients were newly diagnosed in 1993, which suggests that there are many latent or undiagnosed cases in Japan, because SAS is newly diagnosed in 75,000 patients every year in the USA. Here we reported on issues related to the diagnosis and treatment of SAS in Japan and in other countries.

[Daytime pulmonary hypertension in the obstructive sleep apnea syndrome]

Patients with obstructive sleep apnea syndrome (OSAS) may have daytime pulmonary hypertension (PH). Transient and sometimes severe elevations of pulmonary arterial pressure during sleep as a result of intermittent upper airway obstruction may lead to daytime PH. We sought to study the factors involved in the development of daytime PH. Right-heart catheterization, pulmonary function tests, and arterial blood gas measurements were done in 25 patients in whom OSAS was diagnosed by whole-night polysomnography. Eight of the patients (32%) had PH, defined by a mean pulmonary arterial (PA) pressure > or = 20 mmHg. For the group as a whole, mean PA pressure was positively and significantly correlated with daytime PaCO2 (r = 0.79), percent of ideal body weight (r = 0.45), and Hb (r = 0.40). Mean PA pressure was negatively and significantly correlated with PaO2 (r = -0.54), FEV 1% (r = -0.52), and %FVC (r = -0.68). In contrast, mean PA pressure was not significantly correlated with apnea index or with sleep desaturation. These data indicate that daytime PH was not directly related to sleep-disordered breathing, but was related to daytime hypoxemia, daytime hypercapnia, obesity, obstructive and restrictive respiratory impairments, and secondary polycythemia.

[Puerperal secondary pulmonary hypertension in a patient with mixed connective tissue disease]

A woman with mixed connective tissue disease (MCTD) developed pulmonary hypertension after delivery of a child, but had little evidence of parenchymal lung disease. This 29-year-old woman had been given a diagnosis of MCTD when she was 19 years old. She was admitted to our department two days after delivery of a child, because of dyspnea on exertion. Acute thromboembolism was suspected because of: (1) chest roentgenogram showing cardiomegaly and enlargement of the left main pulmonary artery, (2) a lung perfusion scan showing a segmental defect in the left S6 and S8 areas, (3) laboratory studies showing abnormally high WBC, LDH, FDP, and D-D dimer, and (4) arterial blood gas analyses showing mild hypoxemia and hypocapnia. Thrombolytic therapy with heparin and urokinase was begun, and was followed by a loop diurtic and anticoagulation with warfarin. One month after admission, cardiac enlargement and the A-aDO2 were found to have decreased. At that time, cardiac catheterization was done and revealed pulmonary hypertension (mean PA pressure: 45 mmHg) and low cardiac output with no detectable thrombosis in the left pulmonary artery. The patient was subsequently treated with a calcium antagonist and a prostacyclin derivative, and her condition was stable for 5 months. Then her exercise tolerance gradually decreased due to shortness of breath, and cardiomegaly gradually increased over the next 3 months. Eight months after delivery of the child, the patient died of right heart failure. In clinically stable patients with MCTD, delivery of a child may lead to pulmonary thromboembolism and pulmonary hypertension.

[Interleukin-2 activity in monocrotaline-treated rat lungs]

To study the relationship between cytokines and the development of monocrotaline-induced pulmonary hypertension, monocrotaline was given and interleukin-2 was measured. The amount of interleukin-2 produced by pulmonary cells obtained by bronchoalveolar lavage was high only on the 14th day after monocrotaline injection (p < 0.01). This suggests that many kinds of cells in the monocrotaline-treated rat lung were activated by cytokines, and that these interactions play an important role in the development of monocrotaline-induced pulmonary hypertension in rats.

[A case of idiopathic pulmonary arteritis with positive anti-myeloperoxidase antibodies]

A 38-year-old woman was referred to our hospital for severe pulmonary hypertension (pulmonary arterial pressure 63/36 mmHg). Digital subtraction angiography showed complete obstruction of the right main pulmonary artery and severe stenosis of the left main pulmonary artery. Although there were no symptoms or signs of systemic arterial lesions, the initial diagnosis was aortitis syndrome with pulmonary arterial involvement, and prednisolone therapy was started (60 mg/day). Pulmonary arterial pressure decreased to 53/12 mmHg. At a dosage of 20 mg/day, however, multiple nodular shadows were present on the X-ray film of the chest, but they disappeared after the dosage was increased. The level of anti-myeloperoxidase antibodies in her serum changed at almost the same time as multiple nodular shadows appeared on the chest X-ray film. Because anti-MPO antibodies have been never detected in patients with aortitis syndrome, polyangitis overlap syndrome was suspected. However, we found no evidence of systemic vasculitis; that is, vasculitis in other organs, including the kidney and the skin. Therefore, we made a diagnosis of idiopathic pulmonary arteritis with positive anti-MPO antibodies.

[Effects of beraprost sodium (a PGI2 derivative) on chronic hypoxic pulmonary hypertension in the rat]

To determine whether beraprost sodium (beraprost) can cause pulmonary vasodilation in chronic hypoxic pulmonary hypertension, we measured the hemodynamic effects of intravenous beraprost, a stable and orally active agent with a PGI2-like structure, in chronic hypoxic (H) and normoxic (N) rats. During anesthesia baseline pulmonary artery pressure (PAP) was 32.0 +/- 1.0 in H rats and 18.0 +/- 0.4 mmHg in N rats. Intravenous beraprost (20 micrograms/kg) elicited acute pulmonary vasodilation by 17.7 +/- 4.6% (5.6 +/- 1.4 mmHg) in H rats and by 16.8 +/- 2.1% (3.0 +/- 0.6 mmHg) in N rats, which indicates that the relative degree of acute pulmonary vasodilation caused by beraprost was similar in H and N rats. Thirty minutes after the drug was injected, PAP had not returned to baseline levels in either H or N rats, and it was lower in H rats (90 +/- 2%) than in N rats (95 +/- 2%). Lungs were isolated and perfused with saline, and those from H rats and N rats showed similar pulmonary vasodilator responses to 2 and 20 micrograms/kg beraprost. These results indicate that although beraprost caused a similar degree of acute pulmonary vasodilation in H and N rats, in H rats the response lasted longer. Thus PGI2 derivatives may be useful as vasodilators in some patients with primary and secondary pulmonary hypertension.

Evaluation of metastatic ability at specific times during primary tumor growth: a novel spontaneous metastasis assay

A transformed NIH 3T3 fibroblast cell line, Cl-e, normally does not produce spontaneous metastasis from subcutaneous or footpad tumors in nude mice. However, pulmonary tumor nodules are formed when more than 1 x 10(3) cells are injected intravenously into nude mice. Co-injection of 1 x 10(6) heavily irradiated and inactivated cells increases the clonogenic ability of the viable cells in that tumor colonies then occur with as few as 1 x 10(2) viable cells. Utilizing the action of these inactivated cells to enhance the lung colonizing ability of a relatively small number of viable tumor cells, we have developed a novel experimental model of spontaneous metastasis. In this model, a footpad tumor of the nude mouse metastasizes to the lungs following intravenous injection of 1 x 10(6) inactivated cells at a specific time of tumor growth and following tumor foot amputation, whereas no spontaneous metastasis develops without injection of inactivated cells. This model enables us to detect metastatic ability which would otherwise be too low to detect using other assays. In addition, it allows us to evaluate metastatic ability at a specific time point during primary tumor growth, since no metastases can develop during the periods before inactivated cell injection and after tumor amputation. Using this model, we have determined that the metastatic ability of Cl-e tumors in the footpad is constant throughout the exponential and stationary growth phases, even though cells isolated from exponentially growing tumors possess a 3.3-fold greater lung colonizing ability following intravenous injection than those from stationary tumors. This new experimental model may be applicable to other tumor cell lines and to other analyses where metastatic ability during a defined interval of tumor growth is of importance.

The structure and physicochemical properties of rat liver macrophage migration inhibitory factor

We expressed rat macrophage migration inhibitory factor (rMIF) in E. coli using the cDNA isolated from a rat liver cDNA library. rMIF specifically bound glutathione (dissociation constant = 500 microM). We purified rMIF homogeneously on SDS-PAGE by S-hexylglutathione Sepharose affinity column chromatography and Sephadex G-100 column chromatography. The amino-acid sequence of rMIF was highly homologous to that of human MIF from a T-cell line; only a single amino-acid residue was substituted if conservative amino-acid substitutions were involved. The molecular weight of rMIF was calculated to be 12.4 kDa and 23.6 kDa by SDS-PAGE and analytical ultracentrifugation, respectively. Thus, it was concluded that the native rMIF formed a homodimeric structure. Proton nuclear magnetic resonance (1H-NMR) study revealed that rMIF was less thermostable (the denaturing temperature was from 50-60 degrees C) than human MIF (the denaturing temperature is about 80 degrees C (Nishihira et al. (1993) Biochem. Mol. Biol. Int. 31, 841-850). The secondary structure of rMIF evaluated by 1H-NMR experiments revealed that the contents of alpha-helix, beta-strand, and coil were 13.8%, 55.6%, and 30.6%, respectively.

[Changes in smooth muscle cell proliferation in pulmonary arteries of rats given monocrotaline]

To study the relationship between proliferation of smooth muscle cells and structural changes in arteries of rats given monocrotaline, light microscopy with immunohistochemistry for bromodeoxyuridine (BrdU) was done after a single subcutaneous injection of monocrotaline. In increase in DNA synthesis in smooth muscle cells was seen from 3 days until 14 days after administration. Since this increase was seen before pulmonary hypertension and medial thickness developed some mechanisms that induce proliferation of pulmonary atrial smooth muscle may have been triggered soon after monocrotaline injection.

Transcutaneous blood glucose monitoring system based on an ISFET glucose sensor and studies on diabetic patients

A transcutaneous blood glucose monitoring system consists of an ion-sensitive field-effect transistor (ISFET) glucose sensor unit and a suction effusion fluid (SEF) collecting unit. The SEF is directly collected by a weak suction (400 mmHg absolute pressure) through the skin from which the corneum layer of the epidermis has been previously removed. An ISFET glucose sensor unit is able to measure glucose concentrations in a microliter order sampling volume. The system was applied to three diabetic patients during a 75 g oral glucose tolerance test for monitoring blood glucose levels. During the experiments, glucose changes in the SEF followed actual blood glucose levels with 10 min delays. Results suggest the feasibility of utilizing quasi-continuous, transcutaneous blood glucose monitoring for individual patients with various diabetic histories or diabetic complications.

[Does nocturnal hypoxia relate to acute exacerbation of chronic respiratory failure with right heart failure in late sequelae of pulmonary tuberculosis?]

Thirty-eight patients with late sequelae of pulmonary tuberculosis (TB seq.) were studied to clarify whether or not nocturnal oxyhemoglobin desaturation (NOD) could relate to acute exacerbation of chronic respiratory failure (AE). All patients had been untreated with home oxygen therapy, because they were not severely hypoxic. We performed sleep studies, pulmonary function tests and arterial blood gas analysis and investigated past history about AE in each patient. Twelve patients had experienced AE with right heart failure and they were classified as CHF (congestive heart failure) group. The rest was classified as Non-CHF group. These two groups were compared as for each variables examined. There was no difference between the two groups in age, body weight, %VC, FEV1.0%, and awake PaO2. Awake PaCO2 was significantly higher in CHF group. Although no difference was observed in baseline SaO2, the degree of NOD was significantly greater in CHF group when evaluated by lowest SaO2 during sleep and 85% desaturation time (total time spent with SaO2 less than 85%). Moreover, 21 of Non-CHF and 6 of CHF were studied for cardiac parameters using right side cardiac catherization. While the differences of mean pulmonary arterial pressure and cardiac output between the two groups were not significant, pulmonary arteriolar resistance was higher in CHF group. We concluded that NOD in TB seq. had a major role in AE with right heart failure. We speculated that AE might be caused, at least partly, by pulmonary vasopressor response to recurrent NOD.

[Sleep apnea syndrome]

Excessive daytime sleepiness (EDS) in certain patients with sleep apnea syndrome may be the result of intermittent upper airway obstruction during sleep. The possible occurrence of daytime hypertension and pulmonary hypertension (PH) in these patients has been emphasized. Transient and sometimes severe elevations of systemic and pulmonary arterial pressures during sleep as a result of intermittent upper airway obstruction may lead to EDS, daytime hypertension, and PH. The aim of the present study was to investigate whether daytime hypoxemia and hypoxemia during sleep contribute to EDS, daytime hypertension, and PH. The results indicate that: (1) sleep disturbance and blood gas changes while awake and asleep may play a role for EDS, although these abnormalities were not present in some cases, (2) hypoxemia while awake and asleep is probably not involved in daytime hypertension, and (3) mean resting pulmonary arterial pressure is correlated with daytime PO2, PCO2, %IBW, %FVC, and FEV1.0%, Cardiopulmonary hemodynamic function may return to normal in some patients who receive appropriate treatment.

[Thermographic assessment of Raynaud's phenomenon in childhood mixed connective tissue disease]

To assess Raynaud's phenomenon objectively, thermographic estimation of hands and fingers was performed before and after the disease- and Raynaud's phenomenon-directed therapy in 3 children with mixed connective tissue disease. All the cases were positive in Raynaud's phenomenon, and the surface temperature of their hands and fingers were decreased even before cold challenge. After the cold provocation test at 4 degrees C for 10 sec., the temperature of all or some of the fingers were rapidly decreased, and the recovery of surface temperature of these fingers were markedly delayed. Even after methylprednisolone pulse therapy the pattern of the finger temperature were essentially unchanged, suggesting that steroids are not effective in the treatment of Raynaud's phenomenon. The long-term administration of vitamin-E, oral prostaglandin E1, and/or serotonin-receptor inhibitor were also proved to be not beneficial in improving Raynaud's phenomenon. Thus, thermography is useful in diagnosing Raynaud's phenomenon objectively, in determining the efficacy of anti-Raynaud drugs, and in estimating long-term course of the phenomenon.

[Familial Behçet's disease--a case report]

We reported a case of mother and child affected with Behçet's disease. Both had recurrent oral ulcer, erythema nodosum and arthralgia. Neither had gastrointestinal manifestation nor central nervous system involvement. The mother represented positive pathergy test, but the child did not. Laboratory data suggested no severe sign of inflammatory reaction and increased levels of immunoglobulin D. She was diagnosed as incomplete form, and he was diagnosed as suspicious form of Behçet's disease. On HLA examination, they had common haplotypes of HLA A24, B61, Cw1 and DR8. Additionally, haplotypes of HLA B7, Cw7, DR1, DQ1, were also detected in the mother, and HLA A2, Cw3, DR12, in the child. HLA-B51, which is primarily associated with Behçet's disease, was failed to be demonstrated. Familial involvement of Behçet's disease were described in only 20 cases, 11 of which had positive HLA B51. These findings suggest that molecular genetic examinations for both class I and II antigens will be necessary for a case of familial involvement.

[Transcortical sensory aphasia in a patient with metastatic brain tumor in the left frontal lobe]

We reported a case of a 62-year-old right-handed woman who had transcortical sensory aphasia caused by a metastatic brain tumor in the left frontal lobe. She had mild right hemiparesis involving the face, without hyperactive tendon reflexes. She had neither sensory disturbance nor other cranial nerve deficits. Her spontaneous speech was fluent, and she sometimes had echolalia. Her object naming, word fluency, verbal comprehension and writing were severely disturbed. This contrasted with full preservation of repetition of phonemes and short sentences. Reading of words was preserved. CT scan revealed a subcortical lesion in the left superior frontal gyrus. Gd-enhanced MRI showed a ring-enhanced mass lesion in the frontal lobe outside of Broca's area. We thereby concluded that transcortical sensory aphasia may be caused by frontal lobe lesion independent of the perisylvian speech areas.

Clinical usefulness of CYFRA assay in diagnosing lung cancer: measurement of serum cytokeratin fragment

We evaluated the diagnostic usefulness of measurement of the soluble cytokeratin 19 fragment, a new tumor marker, in 391 patients with lung cancer and in 424 patients with benign lung diseases. Serum concentrations of cytokeratin 19 fragment were measured by a sandwich ELISA (CYFRA). The cut-off value was defined as 3.5 ng/ml, which is associated with a specificity of 85% for benign lung diseases. CYFRA had a high sensitivity (57.5%) in all subjects with lung carcinoma, and had a higher sensitivity for squamous cell carcinoma (73.1%, n = 141) than squamous cell carcinoma-related antigen (61.0%). CYFRA was associated with a relatively high sensitivity (42.1%) in early-stage squamous cell carcinoma (stage I, based on the classification of the Japan Lung Cancer Society), but the CYFRA titer was higher in advanced squamous cell carcinoma than in early-stage squamous cell carcinoma. Our findings suggest that CYFRA is potentially useful for diagnosis and monitoring of lung carcinoma, especially for squamous cell carcinoma.

[A case of juvenile dermatomyositis with calcinosis universalis--remarkable improvement with aluminum hydroxide therapy]

Juvenile dermatomyositis (JDM) is a multisystem disease characterized by acute and chronic nonsuppurative inflammation of striated muscle and skin. JDM is classified into an independent entity in the classification of dermatomyositis, and it is marked by the development of calcinosis late in the course of the disease. Since an appropriate steroid therapy for the disease was established, the prognosis of the JDM has been improved except for a fulminant case. Frequency of calcinosis in JDM also has been decreasing because of the adequate steroid therapy. However, once calcinosis universalis occurs, this is the most troublesome and debilitating complication in JDM. Treatment of calcinosis universalis in JDM, so far, remains unsatisfactory. We report here a case of JDM, who suffered from at the age of 3 years, with calcinosis universalis that showed remarkable improvement to orally administrated aluminum hydroxide.

[Effects of crowding on immune functions in mice]

The effects of several types of crowding on immune functions were studied in mice. This study consisted of two experiments. Experiment one: Male BALB/c mice were initially housed in groups of four mice per cage. After fourteen days of acclimation, the mice were randomly divided into three groups, Control (four mice per cage, control group), Crowd-I (four mice per small space) and Crowd-II (sixteen mice per cage). These conditions were maintained for seven days. The results of experiment one were as follows: (1) The percentage of lymphocytes in the blood of Crowd-II was significantly lower than that of Control (p < 0.05). (2) The percentage of neutrophils and the absolute number of neutrophils in blood of Crowd-II were significantly higher than in Control (p < 0.05). (3) Superoxide production activity (NBT reduction activity) of blood neutrophils in Crowd-II tended to be depressed, and phagocytic activity of neutrophils was significantly depressed in Crowd-II as compared with Control (p < 0.01). These results suggest that the complexity of interrelationships among mice caused by an increase in the number of animals per cage is a very important stress factor. Experiment two: Male BALB/c mice were initially housed in groups of five mice per cage. After fourteen days of acclimation, the mice were divided into three groups, Control (five mice per cage, control group), Crowd-(1) (five mice per cmall space) and Crowd-(2) (twenty mice per cage). In Control and Crowd-(1), the same mice were used as in the acclimation period. These conditions were maintained for seven days. In this period, on the second day, all the mice were injected intraperitoneally with sheep red blood cells (SRBC). The results of experiment two were as follows: (1) The specific humoral immune response to SRBC was investigated in terms of the number of PFC in the spleens and hemagglutination in sera, but significant differences were not found among the groups. (2) Plasma IgG levels in the Crowd-(1) were significantly higher than those in Control (p < 0.05). (3) Both superoxide production activity and phagocytic activity of neutrophils were significantly depressed in Crowd-(2) as compared with Control (p < 0.01, respectively), whereas each neutrophil function of Crowd-(1) tended to be enhanced as compared with Control.

[Evaluation of serum C3 and CH50 levels as markers of disease-activity and indicators of efficacy of treatment of lupus nephritis in childhood]

Serum levels of complement components (C3 and C4) and its activity (CH50) were analysed in 20 children with lupus nephritis from view points of disease-activity and efficacy of therapy. After the initiation of prednisolone or methylprednisolone pulse therapy for children in active phases the depressed C3 and CH50 levels were rapidly recovered to normal ranges within 4 months and 2 months, respectively. On the contrary serum C4 levels were normalized later in 11 months. Increased levels of antinuclear antibody and anti-DNA antibody titers have reciprocally dropped in response to those therapy. However, in 9 of 20 children the titers of antinuclear antibody and anti-DNA antibody remained high. Proteinuria observed in active phases of lupus nephritis has disappeared by therapy in all but two exceptions: these two children were complicated with nephrotic syndrome. Histological improvement after therapy was not observed (WHO classification). These findings suggested that it is useful to monitor serum C3 and CH50 levels but not C4 levels to judge disease-activity, and to evaluate efficacy of therapy of lupus nephritis in childhood.