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Biomedical subjects

N Ohya

Publications and source records attributed to N Ohya.

At least 37 records · Page 2Linked to original sources
PubMed1998

Undifferentiated pancreatic cancer associated with humoral hypercalcemia of malignancy.

We present a case of undifferentiated pancreatic cancer associated with humoral hypercalcemia of malignancy (HHM) in which parathyroid hormone-related protein (PTH-rP) is identified as the causative factor of hypercalcemia. A 61-year-old man was hospitalized with right hypochondralgia. Ultrasound examination and computed tomography demonstrated a large mass in the pancreatic head with liver metastases. Biopsy of the pancreatic tumor demonstrated undifferentiated carcinoma. Serum calcium level and PTH-rP were elevated. Bone scan with technetium-99 demonstrated no accumulation in the bones. Immunohistochemical staining for PTH-rP was weakly positive in the tumor cells. We considered that PTH-rP was the causative factor of HHM in this case from laboratory data and immunohistochemical findings. This rare case was successfully treated with pamidronate disodium, which is a type of bisphosphonate derivative. We compared this case with previously reported cases.

Antineoplastic Agents↗
PubMed1998

Effects of ATP-sensitive potassium channel opener on potassium transport and alveolar fluid clearance in the resected human lung.

Since the effect of an ATP-sensitive potassium channel (KATP channel) opener on the function of alveolar epithelial cells is unknown, the effect of YM934, a newly synthesized KATP channel opener, on potassium influx into the alveolar spaces and alveolar fluid clearance was determined in the resected human lung. An isosmolar albumin solution with a low potassium concentration was instilled into the distal airspaces of resected human lungs. Alveolar fluid clearance was measured by the progressive increase in alveolar protein concentration. Net potassium transport was measured by the change in potassium concentration and alveolar fluid volume. YM934 (10(-4) M) increased net influx of potassium by 140% into the alveolar spaces and also increased alveolar fluid clearance by 60% in the experiments with a potassium concentration of 0.3 mEq/1. Glibenclamide (10(-4) M), a KATP channel blocker, inhibited the YM934-increased influx of potassium transport and the increase in alveolar fluid clearance. Also amiloride (10(-5) M), an inhibitors of apical sodium uptake, blocked the YM934 stimulated increase in net alveolar fluid clearance. These results indicate that a KATP channel opener can effect potassium transport and net vectorial fluid movement across the human alveolar epithelium.

Adenosine Triphosphate↗
PubMed1998

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

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

Animals↗
PubMed1998

Pharyngeal cross-sectional area and pharyngeal compliance in normal males and females.

Obstructive sleep apnea syndrome is ascribed to pharyngeal dysfunction, but there are only a few reports about the normal morphological values in this anatomical region. We measured the pharyngeal cross-sectional area and the compliance (collapsibility), using the acoustic reflection technique with air breathing, in 181 healthy subjects (age 21-69 years). We assessed their sex-related differences, and the effects of age, body size and body postures on these parameters. The pharyngeal cross-sectional area, defined as the region from the fauces to the glottis, posturally changed with successive decreases in the sitting, left lateral decubitus and supine positions. The area was significantly greater in male than in female subjects in the sitting position (p < 0.01), but no difference was present in the recumbent positions. The pharyngeal cross-sectional area did not correlate with either age or body size. The specific pharyngeal compliance was greater in the males than in the females (p < 0.01) and increased with age only in the male subjects.

Adult↗
PubMed1998

Bronchial arterial angio-CT: evaluation of intradural and oesophageal enhancement before bronchial arterial infusion.

Ultrafast CT combined with bronchial angiography (BA angio-CT) demonstrated a supply from the bronchial arteries to the oesophagus and spinal cord which is not identified on conventional bronchial arteriography using a digital subtraction technique. 20 patients with bronchial carcinoma and one with lung metastasis were examined using BA angio-CT, before bronchial artery infusion. 20 ml of non-ionic iodinated contrast medium (300 mgI ml-1) was injected into the bronchial artery, and ultrafast CT of the whole mediastinum was commenced when 10 ml had been injected. The 6 mm single slice mode was used and 40 images were obtained. Intradural and oesophageal enhancement was evaluated on BA angio-CT, and compared with the findings on digital subtraction angiography (DSA) of the bronchial arteries. BA angio-CT clearly showed intradural enhancement in eight patients. Marked spinal cord enhancement was demonstrated in three, and a coaxial catheter technique was used to avoid infusing the intercostal branch of the intercostobronchial trunk. Oesophageal enhancement was demonstrated in 18 patients on BA angio-CT. In contrast, no enhancement of these structures was seen on bronchial arterial DSA. In conclusion, BA angio-CT enabled precise evaluation of intradural and oesophageal enhancement.

Adult↗
PubMed1998

[Three cases of Munchausen's syndrome mimicking connective tissue diseases].

Three young women were admitted to our hospital because of severe anemia and fever of unknown origin. The patients had a long history of frequent hospitalizations and operations. During hospitalization, the patients complained of hematemesis, hematuria and fever, which were sometimes discrepant with their physical and laboratory findings. After the careful observation, the patients were diagnosed as Munchausen syndrome because of either discovery of the tools used to make their symptoms or the patient's confession that these symptoms were made by herself. The patients with Munchausen syndrome sometimes show various symptoms and signs of multisystem inflammatory diseases, which mimick the clinical feature of connective tissue diseases. It is important for rheumatologists to be aware of the existence of Munchausen syndrome among the differential diagnosis of connective tissue diseases.

Adult↗
PubMed1998

[Pulmonary aspergilloma clearly demonstrated by digital subtraction bronchography].

A 69-year-old woman was admitted because of persistent productive cough, low-grade fever and abnormal pulmonary infiltrates. Chest roentgenograms revealed right pulmonary cavitary lesions and infiltrates in both upper pulmonary fields. Digital subtraction bronchography (DSBG) was performed to detect for the presence of pulmonary cavitary lesions. Double-contrast DSBG images clearly revealed marked bronchiectasis in the right pulmonary cavity with aspergilloma in the cavitary lesions. Aspergilloma was not obvious in routine chest roentgenograms and computed tomograms. Asperillus fumigatus was cultured from sputum materials, and aspergilloma of the pulmonary cavity was clinically diagnosed. The infiltrative lesions were thought to be associated with invasive aspergillosis because the patient exhibited persistent low-grade fever and positive inflammatory reactions. Anti-fungal chemotherapy was highly effective in treating these lesions. DSBG is a new, less-invasive bronchographic technique for the evaluation of bronchial trees, and in this case proved useful for the detection of small aspergilloma in pulmonary cavities.

Aged↗
PubMed1996

Lung microvascular pressure profile in acute lung injury.

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

Acute Disease↗
PubMed1996

[Pryce type I intralobar pulmonary sequestration].

A 53-year-old woman had a abnormal shadow in the left lower lung field on a chest radiograph, and occasional bloody sputum. CT scans and an MRI showed an abnormal vessel shadow between the aorta and the heart. An aortogram showed an abnormal artery originating from the descending aorta and entering the left lower lobe, and a pulmonary angiogram revealed no blood supply to the left basal segments. Pryce type I pulmonary sequestration was diagnosed. The patient underwent surgery, and the abnormal artery, 13 mm in diameter, was found to be connected from the descending aorta to the left lower lobe. The abnormal artery was dissected, and the left lower lobe was removed. The postoperative course was uneventful. We collected data on 24 cases of Pryce type I pulmonary sequestration reported in Japan. Such cases are comparatively rare and males are affected more often than females. The patient in the present case was the oldest woman to have undergone surgery for this condition in Japan. In patients who underwent surgery the greatest diameter of the abnormal artery was 18 mm.

Bronchopulmonary Sequestration↗
PubMed1996

Diffuse interstitial pulmonary amyloidosis in rheumatoid arthritis.

We describe a woman with seronegative rheumatoid arthritis (RA) who presented with diffuse septal pulmonary amyloidosis mimicking interstitial rheumatoid lung disease. Her systemic amyloidosis was diagnosed by biopsy of the kidney, stomach mucosa, and salivary glands 28 years after the onset of RA. Diffuse interstitial pulmonary infiltrates had been noted since that diagnosis, but infiltrates had been considered due to rheumatoid lung. Results of pulmonary function tests, which revealed restrictive changes and decreased diffusion capacity, were also compatible with rheumatoid lung disease. Pulmonary amyloidosis was diagnosed at autopsy. Pulmonary amyloidosis should be considered a cause of pulmonary infiltrates in patients with longstanding RA.

Amyloid↗
PubMed1996

[Hemolytic anemias observed in SLE].

Hemolytic anemia observed in patients with SLE include autoimmune hemolytic anemia (AIHA) and thrombotic microangiopathic hemolytic anemia (TMHA). AIHA is caused by anti-erythrocyte antibody, which can be detected by direct Coombs' test. Recently, anti-phospholipid antibody draw attention as a cause of AIHA in SLE. TMHA include thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). Patients with TTP show CNS symptoms and renal damage, while those with HUS develop renal insufficiency, but show minimal CNS symptoms. Clinical findings of TMHA are fever, hemolytic anemia, thrombocytopenia, CNS symptoms, and renal insufficiency, which are quite same as the findings of SLE itself. TMHA should be considered for differential diagnosis in acute exacerbation of SLE.

Anemia, Hemolytic↗
PubMed1995

Origin of posterior pituitary high intensity on T1-weighted magnetic resonance imaging. Immunohistochemical, electron microscopic, and magnetic resonance studies of posterior pituitary lobe of dehydrated rabbits.

RATIONALE AND OBJECTIVES: To investigate the origin of posterior pituitary high intensity (PPHI) seen on T1-weighted magnetic resonance (MR) images. METHODS: Six rabbits, including four rabbits deprived of drinking water for 4 days and two control rabbits, were examined by MR imaging. Plasma vasopressin levels were sequentially measured by radioimmunoassay. Pituitary glands were immunostained with guinea pig anti-rabbit vasopressin antibody, and ultrathin sections of Epon/Araldite-embedded specimens were observed with a transmission electron microscope. RESULTS: In control rabbits, PPHI was noted on T1-weighted MR images, and the posterior pituitary lobe was positively immunostained with anti-vasopressin antibody. At the ultrastructural level, nerve terminals contained numerous neurosecretory granules bearing vasopressin. Conversely, plasma vasopressin levels gradually increased and PPHI was absent in 4-day dehydrated rabbits. The posterior lobe was scarcely stained with anti-vasopressin antibody, and neurosecretory granules were rarely observed. However, a number of small dispersed vesicles, possibly derived from the fragmentation of neurosecretory granule envelopes, were seen in the nerve terminal. CONCLUSIONS: Posterior pituitary high signal seen on T1-weighted MR images is attributed to neurosecretory granules bearing vasopressin.

Animals↗
PubMed1995

[A case of pulmonary thrombosis associated with primary antiphospholipid syndrome].

A 23-year-old man was admitted because of an attack of chest pain and dry cough. Chest roentogenogram showed a solitary pulmonary nodule in the left upper lobe. Chest CT showed a nodule and a small pleural effusion on the same side. Pulmonary thrombosis was diagnosed by pulmonary Ventilation/perfusion scintigraphy and pulmonary arteriography. Deep vein thrombosis was not detected except in a distal pulmonary artery. The solitary nodule disappeared spontaneously without thrombolytic therapy. An anticardiolipin antibody (IgG) test was positive. Primary antiphospholipid syndrome was diagnosed, because of the absence of physical findings suggesting other collagen vascular diseases. Patients with antiphospholipid syndrome have a high frequency of pulmonary complications that include pulmonary hypertension and pulmonary embolism. Most of the patients with pulmonary embolism have deep vein thrombosis, and pulmonary vessel thrombosis as seen in the present case is a rare complication.

Adult↗