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Biomedical subjects

K Ohara

Publications and source records attributed to K Ohara.

At least 253 records · Page 14Linked to original sources
PubMed1990

[Influences of intra-aortic balloon pumping on superior mesenteric flow dynamics].

The influences of intra-aortic balloon pumping (IABP) on arterial flow of the superior mesenteric artery were assessed by Doppler echocardiography. The subjects were 13 patients postoperatively, requiring IABP support to control low cardiac output state, in which distal aspects of balloons were distal to the superior mesenteric artery. Superior mesenteric flow velocity integral in systole (IntS) and that in diastole (IntD) were measured from superior mesenteric flow pattern, and the sum of IntS and IntD (IntS + IntD) was calculated ON and OFF balloon pumping (IABP ON-OFF test). The same parameters were obtained with balloon inflating on every other beat (IABP 1:2 test); the cardic cycle with balloon assist was defined as "1:2 ON", and that without balloon assist was defined as "1:2 OFF". 1) IABP ON-OFF test. IABP increased IntS from 7.07 +/- 2.56 cm to 9.20 +/- 3.19 cm (p less than 0.05), IntD from 3.00 +/- 1.18 cm to 3.62 +/- 1.40 cm (p less than 0.05), and IntS + IntD from 10.07 +/- 3.48 cm to 12.82 +/- 4.04 cm. Cardiac output increased from 3.89 +/- 1.34 l/min to 4.24 +/- 1.64 l/min with IABP support. The increments in IntS, IntD and IntS + IntD with IABP are attributed, to a large extent, to an increase in cardiac output. 2) IABP 1:2 test. Without balloon inflation, IntS increased (1:2 ON; 7.16 +/- 2.91 cm, 1:2 OFF; 8.41 +/- 3.30 cm, p less than 0.05), and IntD decreased (1:2 ON; 3.51 +/- 1.60 cm, 1:2 OFF; 2.33 +/- 1.25 cm, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Clinical evaluation of imipenem/cilastatin sodium in infectious complications of hematological malignancies. Tohkai Research Group on Infections in Hematological Disorders].

Imipenem/cilastatin sodium (IPM/CS), a newly developed carbapenem antibiotic, was administered to a total of 152 patients with severe infections complicating hematological disorders, of whom 138 patients are included in the present analysis of efficacy and 152 in that of safety. Most of the underlying diseases were acute leukemia (76/138), and most patients suffered from sepsis or suspicion of sepsis (84/138). Out of 138 patients in whom efficacy was evaluable, responses were excellent in 41 patients, good in 55, fair in 19, and poor in 23. The overall clinical efficacy rate was 69.6% (96/138). Prior antibiotic treatment and peripheral neutrophil count had significant effects on the clinical response. The overall eradication rate of bacteria was 76.2%. Adverse reactions were observed in 15 patients (9.9%) and abnormal laboratory test results in 19 patients (12.5%). From the above findings, IPM/CS is considered to be a useful antibiotic for the treatment of severe infections accompanying hematopoietic disorders.

Adolescent↗
PubMed1990

Vitreous as tamponade in healing of rhegmatogenous retinal detachment.

The condition of the vitreous body was assessed by a photographic method after surgical treatment in 116 patients with rhegmatogenous retinal detachment showing horseshoe-shaped retinal breaks. The condition was classified into three groups: 1) the cortical vitreous covered the retinal break under both static and kinetic conditions (complete type), 2) the cortical vitreous covered the break only under the static condition (incomplete type), and 3) the break was not covered by the cortical vitreous (uncovered type). The success rate of the primary surgery was 100% in both the complete and incomplete types, but it was 58% in the uncovered type, where the final success rate after the second surgery was only 89%. The radial retinal folds were found after surgery at a high incidence in the uncovered type. The time required for disappearance of the subretinal fluid was shorter in the complete than in the incomplete type; in the uncovered type it took a long time for the subretinal fluid to diminish. It was concluded that the cortical vitreous served as a tamponade to prevent vitreous fluid flow into the subretinal space, thus facilitating reattachment of the retina.

Adult↗
PubMed1990

Nd:YAG laser photodisruption of the vitreous traction in avulsed retinal vessel syndrome.

We applied Nd:YAG laser photodisruption to vitreous traction in three patients with avulsed retinal vessel syndrome. In every case the vitreous traction on the avulsed vessels was relieved and the vessel that had been avulsed in the vitreous cavity returned to the retinal surface postoperatively. There were no serious intraoperative and postoperative complications, nor was there any evidence of recurrence of vitreous hemorrhage after the treatment.

Aged↗
PubMed1990

[Middle term follow-up and comparative study of valve replacement with four kinds of new model bovine pericardial xenografts].

Our early clinical experience (up to 4 year's follow-up) with four new pericardial xenografts were reviewed. During the period July 1983 to December 1986, 148 Ionescu-Shiley Pericardial Xenografts (ISL) in 130 patients, 68 Carpentier-Edwards pericardial xenografts (CEP) in 65, 32 Mitroflow pericardial xenografts (MF) in 29 and 36 Hancock pericardial xenografts (HP) in 29 have been implanted. The actuarial survival rates at 3.3 years are 89.9 +/- 2.7% for ISL, 92.3 +/- 3.3% for CEP, 93.1 +/- 4.7% for MF and 93.1 +/- 4.7% for HP. Fifteen cases of primary tissue failure (PTF) were caused in all groups but CEP. The actuarial free rates from PTF at 3.3 years were 92.9 +/- 2.4% for ISL, 100% for CEP, 95.5 +/- 4.4% for MF, 82.6 +/- 7.9% for HP. All bioprostheses explanted because of PTF showed commissural tears occurred at the top of the stent posts or at the edge of the stent. In this respect, it is the reason why the cases with CEP were free from PTF that CEP has been achieved to be improved its frame design. The incidences of prosthetic valve endocarditis were not different among these kinds of bioprosthetic valves. The free rates from thromboembolism at 3.3 years were 97.5 +/- 1.5% for ISL, 98.3 +/- 1.7% for CEP, 96.0 +/- 3.9% for MF and 88.7 +/- 6.1% for HP. There was no patient with CEP and MF suffered from thromboembolism with sinus rhythm. In comparison of these 4 valves, we conclude that CEP is useful clinically because of its satisfactory durability and antithrombogenicity.

Adult↗
PubMed1989

[Field localization and verification system for proton beam radiotherapy in deep-seated tumors].

It has been recognized that, for precise localization and verification of radiation fields, a marking drawn on the skin surface is not entirely reliable because its position relative to bony structures or internal organs is not stationary. This is especially true when treating deep-seated tumors located below the clavicle. In proton beam radiotherapy at the University of Tsukuba, we ristrict the margins around the target volume. Therefore, special care in field localization and verification is needed, and we make it a rule to take X-ray pictures on each treatment day. To accomplish this, we have developed a localize-and-verify system by using fluoroscopic techniques and combining it with a real-time digital image processing device. This allows for the formation of a digital image of the proton field and storage it in the optic disc. By using this system as well as verification films, filed placement errors were measured in 10 patients with deep-seated tumors. Out of a total of 190 localizations, 22% exhibited a field placement error of more than 5 mm, where patient positioning and field localization were done by using skin drawings aligned with laser beams. This result strongly suggests the necessity for daily localization and verification of radiation fields, as is being done by us, for precision in the execution of proton beam radiation therapy.

Adult↗
PubMed1989

Irradiation synchronized with respiration gate.

A respiratory gating technique was developed for radiotherapy of tumors unable to remain stable due to respiration. Irradiation was started and stopped with a microwave oscillator of a linear accelerator controlled by gating signals at specific points in the respiratory cycle. This technique was tested in a phantom specially designed to simulate a patient with lung cancer and in clinical therapy for lung tumors of seven patients. A mask was used to check ventilation in the phantom and airbags were used to measure thoracoabdominal pressure in patients and in the phantom; this enabled us to detect the excursion of the tumors. Low sensitivity film for verification demonstrated the efficacy of this technique. The gated irradiation was proved to ensure more precise radiotherapy for tumors located close to the diaphragm.

Humans↗
PubMed1989

Thermal salivation in rats, anesthetized with barbiturates, chloralose, urethane and ketamine.

1. The relationship between thermal salivation (TS) and thermoregulation was studied in anesthetized rats. 2. Of the 6 anesthetics used, ketamine-anesthetized rats secreted the largest amount of saliva. Salivation, however, was thermal and not induced by ketamine itself. 3. Ketamine-anesthetized rats readily secreted saliva at core temperatures less than 40 degrees C but TS was remarkably enhanced by hyperthermia of 40-42.5 degrees C. 4. The equilibrium phase in the triphasic heat response of core temperature was a consequence of equilibrium between heat gain and heat loss by salivation.

Anesthetics↗
PubMed1989

Role of positioning holes in intraocular lens glare.

We performed laboratory studies to determine the role of positioning holes in posterior chamber intraocular lens glare. Several areas of the lens optic were illuminated independently, and the scattering light off the lens was photographed. A conventional lathe-cut lens with four positioning holes on the optic produced the most intense light scattering. Scattering off nonilluminated areas was apparent, and it was suggested that the presence of positioning holes on the optic might contribute to the scattering. Optically complex areas including a hole, optic edge, a loop insertion, and optic-haptic junction produced the scattering in all lenses of various designs. An internal reflex inside the optic may occur, and complex or irregular structures in the optic may be a source of light scattering and some intraocular lens glare.

Lenses, Intraocular↗
PubMed1989

Surface quality of intraocular lenses.

We observed circular furrow-like patterns on the implanted intraocular lens surface in postoperative follow-up examination by specular microscopy. The patterns may have been deep lathe-cut marks or compression-related marks on the optics. Specular microscopy, polarized light microscopy, and scanning electron microscopy detected a similar circular mark on the optic surface of a control intraocular lens of the same model. A reconsideration of surface quality is indicated.

Aged↗
PubMed1989

Mortality among alcoholics discharged from a Japanese hospital.

A study of mortality among alcoholics was carried out involving patients discharged from the alcoholic ward of a Hamamatsu University-affiliated hospital from 1972 to 1984 (1021 patients). The average age at death was 48.4 years. The causes of death were divided into three groups; 'diseases', 'accidents', 'suicide and homicide', accounting for 73.5%, 10.5% and 7.3% of 257 deaths, respectively. Death rates per 1000 persons for the years at risk were compared with the expected rates for the general population. Briefly, the death rates for patients were more than 10 times as large as those in the general population. Our results showed that liver cirrhosis and heart failure ranked high among the causes of death in alcoholics. Among patients who died, only 3.1% were total abstainers after discharge from hospital, which was an extremely low proportion in comparison with the average cross-total abstinence rate of 25.8% among patients after discharge.

Adult↗
PubMed1989

A possible mechanism of fever induced by Nocardia rubra cell wall skeleton (N-CWS) in experimental animals.

The characteristics of fever elicited by the cell wall skeleton of Nocardia rubra (N-CWS) and by lipopolysaccharide (LPS) were compared in rabbits, and the possible involvement of the antigenicity of N-CWS was investigated in guinea pigs. In rabbits, fever of more than 0.5 degree C developed after an intravenous (i.v.) injection of 10 micrograms/kg or more of N-CWS, and was monophasic with 30-100 micrograms/kg but biphasic with the highest dose of 300 micrograms/kg. LPS elicited fever with similar characteristics at doses of 0.01-0.1 microgram/kg. With both compounds, the fever was inhibited by indomethacin. Tolerance to N-CWS and LPS appeared after dosing with 30 or 0.1 micrograms/kg, respectively for 10 d. In guinea pigs sensitized with N-CWS, challenge with 1 or 10 micrograms/kg of N-CWS 10 d later, which did not induce fever in the nonsensitized animals, caused fever of more than 0.5 degree C, and delayed-type hypersensitivity (DTH) appeared. N-CWS also elicited fever in nonsensitized guinea pigs bearing N-CWS-sensitized lymphocytes or anti-N-CWS antibody; the fever was higher in the guinea pigs sensitized with the lymphocytes than in those with the anti-N-CWS antibody. In brief, single injections of N-CWS and of LPS elicited fever with similar characteristics, although the potency of N-CWS was weaker. With N-CWS, the fever is proposed to be triggered by the antigenicity of the compound itself, because doses as low as 1 or 10 micrograms/kg elicited fever along with immunological response in N-CWS-sensitized animals, but not in nonsensitized ones.

Animals↗
PubMed1989

Possible involvement of a tumor necrosis factor (TNF)-like mediator as an endogenous pyrogen in fever induction by Nocardia rubra cell wall skeleton (N-CWS).

Tumor necrosis factor (TNF), a cytokine produced in macrophages, also acts as an endogenous pyrogen (EP). To investigate whether TNF has a role in the fever induced by Nocardia rubra cell wall skeleton (N-CWS), the relationship between fever and TNF production was studied in guinea pigs. N-CWS injected i.v. to guinea pigs caused biphasic fever and had L-929 cell-killing activity which resembled that of TNF in the sera 30 min before the first phase of fever appeared. In vitro, L-929 cell-killing activity was demonstrated in the culture supernatant of guinea pig peritoneal macrophages pretreated with N-CWS, and the activity increased dependently on N-CWS concentration or culture duration. When the supernatant of the macrophages was fractionated by gel filtration and each fraction was assayed for fever-inducing and L-929 cell-killing activities, the fraction with the cell-killing activity also induced fever with characteristics similar to that by i.v. injection of N-CWS in guinea pigs. These results suggest that TNF acts as an EP on the fever induced by N-CWS in guinea pigs.

Animals↗
PubMed1989

[Analysis of patients surviving for six months after irradiation of a bone metastasis].

The effects of treatment of a bone metastasis have been studied in 49 patients who survived for more than six months after radiotherapy (RT). Relief from the symptoms reached a rate as high as 91% (85/93 irradiated sites) irrespective of the primary site of the cancer. However, the survival rate and the rate of symptom relief maintenance were statistically higher in those with breast cancer (15 patients, 38 irradiated sites) than in those with a lung cancer (15, 24). The local control rate was dose dependent (TDF). High-dose irradiation, therefore is recommended to achieve a high local control rate for patients with a long life expectancy.

Bone Neoplasms↗
PubMed1989

[Establishment and characterization of human neuroblastoma cell line (HSNB)].

We cultured an aspiration fluid of the sternal bone marrow of the patient having adrenal neuroblastoma and established a neuroblastoma cell line (HSNB). The HSNB line has the following biological properties. 1. They are small round in shape and proliferate in flotation while forming cell aggregate, and often they attach the bottom of plastic dish and process the nerve-like fibers. A rough-endoplasmic reticulum are poorly developed, however, a lot of free ribosomes are scattered in the cytoplasm. In the peripheral area of the cells, small spherical secretory granules (60-140 nm in diameter) are existed. One characteristic of this cell is existence of microtubules in the cell-projections. 2. They show a stable growth and the doubling time is about 50 hours. 3. Their chromosome number varied widely and the mode is 46. The double minute chromosomes were present in 50% of cells. 4. When they are transplanted in the cheek pouch of hamster, they produced the neuroblastoma. 5. They produce neuron specific enolase. 6. N-myc gene was amplified ca 250 folds.

Adrenal Gland Neoplasms↗
PubMed1989

[Clinical observations with clarithromycin in pediatrics].

Clarithromycin (TE-031, A-56268) was given orally to 25 children with acute bacterial infections including 5 with bronchitis, 8 with pneumonia, 4 with Mycoplasma pneumonia, 2 with pertussis and 6 with Campylobacter enteritis. Good to excellent clinical responses were obtained in 22 patients with bacterial eradication of all 10 strains. No side effect was observed. From the above clinical results, it appears that TE-031 is a useful antibiotic for the treatment of pediatrics with various bacterial infections.

Age Factors↗