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Biomedical subjects

M Nitta

Publications and source records attributed to M Nitta.

At least 109 records · Page 6Linked to original sources
PubMed1990

The sleep electrocardiogram at extreme altitudes (Operation Everest II)

To evaluate the effect of sleep at extreme altitudes upon heart rate and rhythm, continuous sleep monitoring was performed in 8 normal young men during a 40-day simulated ascent of Mt. Everest in a hypobaric chamber. Recordings were made for 1 hour before sleep, during sleep and for 1 hour after awakening in all subjects at 760 torr (sea level), in 7 subjects at 390 torr (5,490 m), in 6 at 347 torr (6,100 m) and in 4 at 282 torr (7,620 m). The following results were obtained: periods of sinus bradycardia occurred during sleep in all subjects at 3 altitudes with a mean heart rate of 41 +/- 0.5 beats/min compared to a rate of 44 +/- 2 beats/min at sea level; cycling of the heart rate, presumably due to periodic breathing, occurred in 14 of 17 studies at altitude but not at sea level (cycles consisted of bradycardia [40 beats/min] for 13 seconds and tachycardia [120 beats/min for 5 seconds]; and arrhythmias were observed in all subjects during sleep and consisted of transient bradycardia (heart rates as low as 20 beats/min), sinus pauses frequently associated with escape rhythms and occasional blocked P waves. No arrhythmias were observed at sea level. Simultaneous records of respiration and the electrocardiogram at 12,500 feet (3,810 m) in 5 other normal subjects revealed tachycardia occurring during hyperpnea and bradycardia occurring during apnea. Data indicate that during sleep in normal young subjects at high altitude, cycling of the heart rate with periodic breathing is common, as are bradyarrhythmias. The mechanism of these arrhythmias has yet to be defined.

Adult↗
PubMed1990

The effects of an extradural expanding lesion on regional intracranial pressure, blood flow, somatosensory conduction and brain herniation: an experimental study in baboons.

Intracranial pressure (ICP) differences, change of local blood flow (CBF) using the hydrogen clearance technique, change in the somatosensory evoked potential (SEP) to median nerve stimulation and pupillary size were investigated during progressive elevation of the ICP (using an extradural balloon) in 6 anaesthetized baboons. CBF was measured in the frontal cortex, somatosensory cortex, thalamus (nucleus ventralis posterior lateralis-VPL), medial lemniscus (ML), lateral lemniscus (LL) and caudate nucleus (CN). Conduction along the somatosensory pathway between C2 at the neck and VPL was compared with conduction between VPL and primary somatosensory cortex. The amplitude of the cortical SEP was also studied. ICP gradients between hemispheres developed as the pressure was increased to in excess of 50 mm Hg. CBF was significantly reduced from control in the cortex and VPL on the side ipsilateral to the balloon at 50 mm Hg ICP. A significant decrease in ML flow occurred bilaterally at 70 mm Hg ICP. Conduction time was increased significantly between the right VPL and cortex at a pressure of 50 mm Hg. The amplitude of the cortical response was significantly reduced at 30 mm Hg on the right side and 50 mm Hg on the left. Aniscoria occurred at 50 mm Hg ICP and the pupils became dilated at 70 mm Hg. The SEP was possibly more sensitive than the pupillary reactions as an indication of tentorial herniation in these experiments.

Animals↗
PubMed1990

Multi-drug combination therapy with vincristine-melphalan-cyclophosphamide-prednisolone was more effective than cyclophosphamide-prednisolone in stage III myeloma. The Nagoya Myeloma Cooperative Study Group.

A cooperative randomized clinical trial to compare the effectiveness of multi-drug combination chemotherapy (VMCP), vincristine-melphalan-cyclophosphamide-prednisolone) with CP (cyclophosphamide-prednisolone) for the treatment of multiple myeloma was performed. When the whole group of patients was evaluated, the choice of chemotherapy (VMCP or CP) was not a significant prognostic factor associated with response or survival by uni- or multivariate analysis, and the difference between the survival curves of the treatment groups was only marginally significant. However, when the analysis was confined to stage III patients, the choice of chemotherapy became a significant prognostic factor associated with both response rate and survival, and the statistical difference between survival curves was significant. Taking the disease characteristics of multiple myeloma into consideration, the better result obtained with multi-drug combination chemotherapy in the treatment of stage III patients is consistent with other studies supporting the superiority of multi-drug combination chemotherapy for patients with overt systemic disease.

Aged↗
PubMed1990

[Pure white cell aplasia (PWCA) with an inhibitor against colony-forming unit of granulocyte-macrophage (CFU-GM)].

We reported here a case of pure white cell aplasia (PWCA). A 23-year-old man was admitted to our hospital in September 1989 because of agranulocytosis, fever, and anal pain. He had no history of toxic-drug exposure or blood transfusion. Laboratory studies were all within the normal range except white blood cell count of 2,300/microliters with no neutrophils and low serum IgA level (28 mg/dl). Bone marrow examination showed hypocellular with erythroid predominance and no granulocyte maturation beyond the myelocyte. Complement-dependent suppression of autologous and heterologous granulocyte-macrophage colony-forming units by the patient's serum could be demonstrated. Though corticosteroid administration was ineffective, neutropenia improved by plasmapheresis. Furthermore, recombinant granulocyte colony stimulating factor (rG-CSF) could release him from persistent bacterial infection of anal fistula by transient improvement of neutropenia. These findings suggest a humoral autoimmune mechanism for the pathogenesis of PWCA and the effectiveness of rG-CSF for the patient with severe infections.

Adult↗
PubMed1990

[Two cases of rheumatoid arthritis complicated with vasculitis-induced ischemic enterocolitis].

Episodes of catastrophic entero-colitis associated with mesenteric vascular insufficiency in patients with rheumatoid arthritis(RA) have rarely been recorded thus far. We herein report two cases of RA complicated with severe attacks of entero-colitis presumably due to mesenteric vasculitis. Surgical intervention was necessary in the first case, while the second patient recovered well only through conservative therapy. Case 1: A 74-year-old man with history of RA since 1985 started to complain of abdominal discomfort and nausea early in February, 1989. On February 12, Episodes of tarry stool developed. Rapid down-hill clinical course prompted laparotomy under the clinical diagnosis of peritonitis. Ischemic changes were observed at the ileum end, the entire length of which was 120 cm orally from the cecum. The site was resected. Multiple linear and aphthoid ulcer lesions were discovered throughout the entire lumen. Histopathologically, evidence of necrotizing vasculitis such as fibrinoid necrosis and mural thrombi was demonstrated in small arteries of the submucosal layer underlying the ulcer lesion. Case 2: A 63-year-old woman who had been suffering from RA since 1980 noticed the onset of nausea, abdominal pain and bloody diarrhea in July, 1989. Colonoscopy examination revealed multiple linear and aphthoid ulcers in the sigmoid colon which was presumed to be due to ischemia. Laboratory evaluation at that time demonstrated hypocomplementemia, positive circulating immune complex and high titer of anti-DNA antibody. Corticosteroid therapy with moderate dose was successful in alleviation of all the abnormal findings and the patient fully recovered three months after her initial GI episode.

Aged↗
PubMed1990

[Clinical evaluation of cefbuperazone in severe infections complicated with hematological disorders].

The efficacy and the safety of an antibiotic in cephamycin group, cefbuperazone (CBPZ), were investigated in 93 patients with severe infections complicated with hematological disorders. The efficacy evaluation was made in 85 cases with underlying hematological disorders including 49 cases (57.6%) of leukemia and 18 cases (21.2%) of malignant lymphoma. The overall efficacy rate was 50.6% of the 85 evaluable cases. The clinical efficacy rate for sepsis and suspected sepsis was 53.4%. The most frequently used group of antibiotics for combination therapy was aminoglycosides in 37 cases, in which an efficacy rate of 62.2%, a higher rate than the efficacy rate of 48.5% for all the combination therapy cases, was obtained. In 16 cases in which penicillins were used as combination drug, the efficacy rate obtained was low, 31.3%. Efficacy rates obtained for cases with different neutrophil counts at the start of therapies were as follows: 52.2% in 23 cases with neutrophil counts below 100/mm3, 46.2% in 13 cases with neutrophil counts between 100 and 499/mm3 and 51.3% in 39 cases with neutrophil counts equal to or above 500/mm3, thus no significant differences in efficacy rates were observed for patients with different neutrophil counts. These results appear to suggest that CBPZ, alone or in combination with other antibiotic such as aminoglycosides, may be quite useful in the treatment of severe infections in patients with hematological disorders.

Adolescent↗
PubMed1990

[Serum adenosine deaminase (ADA) activity in patients with active pulmonary tuberculosis].

To clarify the immunological aspect of tuberculosis, we investigated serum adenosine deaminase (ADA) activity, T and B cell percentile in total peripheral mononuclear cells, peripheral T cell subpopulation and their relationship with other inflammatory parameters in 20 patients with active pulmonary tuberculosis. Serum ADA activity showed abnormal high level in all patients in nontreated phase with significant regression after three months treatment by anti-tuberculous drugs (P less than 0.05). In addition, significant positive correlation was observed between serum ADA activity and erythrocyte sedimentation rate at 1 hour (r = 0.56). Concerning about peripheral T cell subpopulation studied by two colour flow cytometry with FITC-conjugated anti-CD4 and phycoerythrin-conjugated anti-HLA-DR antibody, there was positive correlation between CD4(-) HLA-DR(+) T cell and serum ADA activity (r = 0.59) without any abnormal frequency of each T cell subpopulation. Additionally, after the treatment of pulmonary tuberculosis, significant increase of T cell percentile in total peripheral mononuclear cells were observed (P less than 0.005). In conclusion, these results may suggest serum ADA activity could be a parameter of activity of pulmonary tuberculosis and reflect the function of activated suppressor/cytotoxic T cell.

Adenosine Deaminase↗
PubMed1989

[T cell subsets as a prognostic factor in the chronic phase of chronic myelogenous leukemia].

A relationship between the survival time and T cell subsets in the chronic phase of chronic myelogenous leukemia (CML) studied by the method using monoclonal antibodies. No statistic difference between normal and CML was recognized in the rate of pan-T cell. The high T-Helper/Suppressor ratio (TH/TS) was revealed in the cases of the long survival time for more than six years.

Humans↗
PubMed1989

[Effects of hemodialysis on left ventricular performance: a Doppler echocardiographic study].

Left ventricular systolic and diastolic performance was examined using Doppler and M-mode echocardiography in 42 patients with chronic renal failure before and after hemodialysis. Twenty patients with left ventricular hypertrophy, 22 without hypertrophy and 30 normal subjects were studied. Chronic renal failure patients showed significantly larger chamber diameters of the left ventricle, left atrium and right ventricle than did normal subjects. This group also exhibited greater fractional shortening, stroke volume and cardiac output. Before hemodialysis, patients with left ventricular hypertrophy had a significantly higher cardiac output and the greater ratio of late to early diastolic peak flow velocities (A/R) than did patients without hypertrophy. After hemodialysis, there were significant reductions in blood pressure, ventricular and atrial dimensions, stroke volume and cardiac output. The velocities of early and late diastolic left ventricular filling and the deceleration rate were also significantly reduced. The heart rate, A/R, deceleration half time, and the ratio of deceleration half time to acceleration half time (DHT/AHT) were significantly increased. The greater the amount of fluid removed, the greater the changes in the above values. Patients with left ventricular hypertrophy exhibited significant reductions in fractional shortening, ejection fraction, stroke volume and cardiac output, compared to those without hypertrophy. However, patients without hypertrophy showed more significant decrease in the acceleration half time and increase in DHT/AHT than did patients with hypertrophy. These findings demonstrated normal systolic function and impaired diastolic properties in patients with chronic renal failure, who had left ventricular hypertrophy unaccompanied by dilatation.

Adult↗
PubMed1989

[Initial symptoms of hematemesis from gastric varix with chromosomal abnormalities of t(2; 8) and 14q+ in a patient with acute lymphoblastic leukemia (FAB: L3)].

A 71-year-old woman was hospitalized because of hematemesis on December 1, 1987. Her white blood cell (WBC) count was 41,200/microliters with 48% of lymphoblasts, and the bone marrow was hypercellular with more than 90% of blasts. The diagnosis of acute lymphoblastic leukemia (ALL) (FAB: L3) was made by morphologic, cytochemical and immunologic studies of the blasts. The examination of fiber gastroscope revealed remarkable varix in the stomach, suggesting portal hypertension accompanied by infiltration of leukemic cells into reticulo-endothelial system. She died of respiratory failure because of bleeding into the trachea. The autopsy disclosed the massive infiltration of leukemic cells into the whole organs. In the chromosome study of the peripheral blood, t(2; 8) and 14q+ were observed, and these chromosomal abnormalities are relatively unusual in patients with Burkitt's lymphoma.

Aged↗
PubMed1989

[Effects of ceftriaxone on severe infectious complications in hematological disorders. Tohkai Research Group on Infections in Hematological Disorders].

Ceftriaxone (CTRX), a new long acting antibiotic in the 3rd generation cephem group, was administered intravenously once or twice a day in daily doses of 1-6 g for at least 3 days to 86 patients with severe infections complicating hematopoietic disorders. Underlying diseases were acute leukemia in 41 cases, chronic leukemia in 3 cases, malignant lymphoma in 19 cases, myeloma in 7 cases and others. Most patients (55 cases) suffered from sepsis or suspected sepsis. As for efficacy rates classified by underlying diseases, the treatment was effective in 61.0% of patients with acute leukemia. As for efficacy rates classified by infections, the treatment was effective in 60.0% of patients with sepsis. No side effects were noted except rash in 2 patients. Abnormal hepatic functions were recognized in 3 patients but were not attributed to the agent in any case. The results indicate that CTRX is a safe and useful antibiotic for the treatment of severe infections accompanied by hematopoietic disorders.

Bacterial Infections↗
PubMed1989

[Chromosomal abnormality of trisomy 4 in a patient with acute nonlymphocytic leukemia (FAB: M2)].

We report a patient with acute nonlymphocytic leukemia (FAB classification: M 2) with trisomy 4, which is the first case in our country. A 42-year-old man was admitted to our hospital because of fever and general fatigue in May, 1988. His WBC count was 8,100/microliters with 90% of leukemic cells and bone marrow smear showed 76.1% leukemic cells. The chromosomal analysis of marrow cells by G-banding revealed 47, XY, +4. In spite of administration of chemotherapy complete remission was not obtained, and he died of septic shock and severe liver damage 4 months after making the diagnosis. Chromosomal abnormality of trisomy 4 has been reported to be associated with predominantly either M 4 or M 2, and to be less than 0.1% of incidence in ANLL, according to the Second MIC Cooperative Study Group. It is suggested that trisomy 4 may be caused by exposure to some environmental factors such as toxic substances, since this chromosomal abnormality has been reported in the last 10 to 20 years.

Adult↗
PubMed1989

Southern blot analysis of Bcr, N-ras, H-ras, c-myc and myb proto-oncogenes in blast crisis of chronic myelogenous leukemia.

Proto-oncogenes were studied by Southern blotting in 12 patients with chronic myelogenous leukemia in blast crisis (CML). Cytogenetically, all cases had Philadelphia (Ph1) chromosome and 4 had additional chromosomal abnormalities including +8, +19, i(17q), double Ph1. The bcr gene was rearranged in all cases and the region of breakage points were located in the 5.8 kb Bgl II-Bam HI fragment of bcr. In a case with double Ph1 the breakage points of bcr were thought to be different from each other. We analyzed other proto-oncogenes (N-ras, H-ras, c-myc and myb) by Southern blotting, but did not find any abnormalities.

Adult↗
PubMed1988

Prevalence and characteristics of the aortic ejection sound in adults.

A survey of 1,950 phonocardiograms recorded over a 6-year period revealed 170 (9%) with a distinct aortic ejection sound. All patients were men with a mean age of 61 years (range 29 to 88). Associated clinical features were: aortic stenosis in 28%, history of systemic hypertension in 10%, history of rheumatic fever in 4% and none of these features in 58% of patients. In 141 (83%) of 170 patients the aortic ejection sound occurred simultaneously with or 0.01 second before or after the onset of the rise of the externally recorded carotid pulse. In 37 (66%) of 56 patients who had simultaneous echocardiograms and phonocardiograms recorded, the aortic ejection sound occurred at 0.01 second before or after the maximal opening point of the aortic valve leaflets. Two-dimensional echocardiography was performed in all patients and a bicuspid aortic valve was identified in 38 patients (22%). In 83 patients (49%) 3 cusps were clearly seen. In 49 patients (29%) an accurate determination was not possible. Anatomic examination of 120 consecutive aortic valves at autopsy was performed to identify possible causes of the aortic ejection sound. In 18 (15%) of autopsies fusion of 2 aortic cusps extending greater than or equal to 5 mm from the attachment to the aorta was observed. This abnormality, aortic commissural fusion, may be congenital or acquired. It is concluded that aortic ejection sounds may occur in patients without bicuspid aortic valves and in a variety of clinical conditions. A moderate degree of cuspal fusion may be the cause of the sound.

Adult↗