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Biomedical subjects

A Kitamura

Publications and source records attributed to A Kitamura.

At least 127 records · Page 7Linked to original sources
PubMed1991

Stereotactic Aqua-Stream and Aspirator in the treatment of intracerebral hematoma. An experimental study.

The efficacy of the Stereotactic Aqua-Stream and Aspirator (SAS&A) was experimentally investigated by using hematoma models in the test tube and in gelatin. Even a solid hematoma can be crushed by the water jet and aspirated easily. The greater the positive pressure of the water jet and the negative pressure of suction, the stronger the ability to remove clots. A water jet pressure of 10-20 kg/cm2 and a suction pressure of 100-200 mm Hg were sufficient to remove experimental clots from the test vessels. When the SAS&A was operated in the brain of dogs with a water jet pressure of 20 kg/cm2 and a suction pressure of 200 mm Hg, aspirated brain tissue was less than 15 mg/min in weight, and histological brain injuries were observed only in the area less than 2 mm from the window of the probe, indicating that the procedure with the SAS&A would be relatively atraumatic. We conclude that these observations indicate that the SAS&A can be safe and extremely useful for removal of hypertensive intracerebral hematomas, even in the acute stage.

Animals↗
PubMed1991

Use of a triple protease-deficient mutant of Bacillus subtilis as a host for secretion of a B. subtilis cellulase and TEM beta-lactamase.

The mature portion of the TEM beta-lactamase (BLA) gene (bla) derived from pBR322 was fused with the promoter and signal region of Bacillus subtilis cellulase (BSC) gene (bsc), and the productivity was compared with that of the cloned native bsc gene, using a wild-type B. subtilis strain and a strain deficient in three proteases (i.e., extracellular serine protease, extracellular neutral protease, and the major intracellular serine protease) as hosts. The effects of the sen, sacQ, and prtR genes, carried on the same plasmids, were tested as for the productivities of BSC and BLA. The production of BSC was increased 9-fold by using the combination of the triple-protease deficient strain and the sacQ gene, compared with that by using the wild-type strain as a host, and no degradation of BSC was observed in the triple-protease deficient strain. On the other hand, though the production of the BSC-BLA fusion protein increased 2.5-fold in the triple-protease deficient strain, the BLA activity was decreased after the cell reached the stationary phase of growth, possibly due to some proteolysis. These observations show different sensitivity of secretary proteins to cellular proteases, and suggest that BLA is decomposed by remaining minor proteases.

Amino Acid Sequence↗
PubMed1991

[A case of small cell carcinoma originating at the site of pneumoplication of giant bulla five years later].

A 64 year-old man was performed pneumoplication for his left-sided giant bulla on December 15, 1983. After five years, consciousness loss and right hemiplegia occurred. Brain CT revealed a cystic lesion with enhancement in the left occipital lobe. Brain biopsy disclosed metastatic small cell carcinoma. Lung biopsy showed the same histopathology, so primary lesion was considered to be from the site of the previous pneumoplication. Lung cancer associated with emphysematous bulla have been mostly characterized by tumor shadow or niveáu in the bulla. In this case, the postoperative infiltrating shadow of pneumoplication had made early diagnosis difficult.

Carcinoma, Small Cell↗
PubMed1991

[A population-based study of the proportion by type of stroke determined by computed tomography scan].

To investigate the proportion by type of stroke in communities, a stroke surveillance was conducted in three rural populations between 1979 and 1987. Among 411 stroke patients aged 40 and over determined by the modified Millikan's stroke criteria, the type of stroke was analyzed using computed tomography (CT) criteria for 273 patients who were examined by CT. 1. Incidence rates of stroke determined by the modified Millikan's criteria did not vary among the three populations in all age-sex groups except for men aged 60-69. 2. The proportion of stroke patients who had CT examinations was 84-88% for men and women aged 40-69 in the three communities. 3. According to the CT criteria, the proportion by type of stroke in patients aged 40-69 in the three communities was 32% for cerebral hemorrhage, 16% for subarachnoid hemorrhage, 42% for cerebral infarction and 10% for unspecified stroke without CT abnormalities. Among the total with cerebral infarction, the proportion with cerebral infarction in penetrating artery regions, mostly lacunar infarction, was 65% and that of infarction in cortical artery regions, mostly thromboembolic infarction, was 35% for patients aged 40-69. 4. Cerebral infarction in cortical artery regions was classified further into embolic, thrombotic and unspecified types based on CT findings, the presence of embolic origin, and symptoms at the onset. The proportion of these three types of infarction were similar in patients aged 40-69. Compared with hospital-based studies in Japan, the present population-based study showed a higher proportion of cerebral infarction and infarction in penetrating artery regions. This study also indicated that the proportion of cerebral hemorrhage and infarction in penetrating artery regions was higher and that of infarction in cortical artery regions lower in Japanese than in Caucasians.

Adult↗
PubMed1991

Ventilatory effects of percutaneous magnetophrenic stimulation.

This study was conducted with the purpose of elucidating the ventilatory effect of percutaneous magnetic stimulation of the phrenic nerve and investigating the possibility of clinically utilizing this effect as the mechanism of an artificial respirator. A magnetic stimulator consisting of a flat circular coil generating strong magnetic fields up to a maximum of 1.3 Tesla was developed. Formed from 1.8 mm diameter copper wire, this coil is 40 mm in diameter, 14 mm in thickness and has an inductance of 24 microH. The appurtenant current generator can deliver more than 5000 A to the coil. The capacitor terminal voltage (Vc) of the generator was used as a parameter of the intensity of the stimulus. Ventilatory effects were assessed mainly by diaphragmatic electromyogram and by transdiaphragmatic pressure, ventilation flow and tidal volume measurements. Magnetic stimulation was applied percutaneously to a unilateral phrenic nerve in dogs as well as human subjects and also to a median nerve of the forearm in human subjects. The range of stimulatory intensity Vc necessary to obtain ventilatory effects was 400-500 V, and the tidal volume thus obtained corresponded to normal breathing at rest for both dogs and humans. No pain was felt in the vicinity of point of application of the stimulator and there were no significant adverse effects such as changes in the ECG or heart rate. These results indicated that percutaneous magnetic stimulation of the phrenic nerve could produce adequate ventilatory effects in control applications.

Animals↗
PubMed1991

[Secular trends in prevalence and incidence of atrial fibrillation and associated factors in a Japanese rural population].

To investigate secular trends in prevalence and incidence of atrial fibrillation and associated factors, data from population studies of a northeast rural Japanese community, were explored. Cross-sectional studies for men and women aged 40-69 year were conducted in 1963-1966, 1972-1975 and 1984-1987. Age-adjusted prevalence rates of atrial fibrillation show no significant change in both men and women during these three periods. Over 80% of atrial fibrillation in each period showed no clinical evidence of rheumatic valvular disease, myocardial infarction, idiopathic cardiomyopathy, congenital heart disease and hyperthyroidism. Cohorts of men and women aged 40-69 year without atrial fibrillation at baseline were constructed in 1963-1966 (1,920 persons) and in 1972-1975 (2,325 persons) and followed until 1974 and 1987, respectively. In both cohorts, incidence of atrial fibrillation without these organic diseases was positively associated with hypertension related funduscopic abnormality and urine protein. Age-adjusted incidence rates of atrial fibrillation declined in both men and women between the two cohorts. This decline which was greater in hypertensives than in normotensives may in part reflect improvements in hypertension control in this community.

Adult↗
PubMed1990

Computed tomography in the evaluation of postoperative maxillary cysts.

Twenty-two cases (34 sides) of postoperative maxillary cysts evaluated with axial and coronal computed tomograms were reviewed. Precise characteristics pertaining to the extent of maxillary sinus involvement, loculation, presence of septae, bony perforation, and associated cystic projection or extension into adjacent structures were determined. Of the 34 sides, 13 cysts involved the sinus completely. Twelve were multilocular. Thirteen exhibited incomplete septae. Perforations were most frequent in the anterolateral and medial bony walls (28 and 27, respectively); however, the 14 posterolateral wall perforations showed a higher percentage of cystic projection into adjacent structures. Ethmoid extension was seen on two sides, orbital extension on one. Nine sides showed tooth roots communicating with the cyst. The routine use of computed tomography in the evaluation of this type of cyst is proposed.

Adult↗
PubMed1990

Stereotactic aqua stream and aspirator for removal of intracerebral hematoma.

The stereotactic aqua stream and aspirator is modified from the aqua stream and aspirator for stereotactic evacuation of intracerebral hematoma. The newly designed needles were adapted to Leksell, Patil, Komai and Sugita stereotactic equipment. The new device was used in 14 cases with intracerebral hematoma. The tips of the needles were stereotactically inserted into the center of the hematoma cavities. The ratios of evacuated hematoma against hematoma content varied from 73 to 98%, averaging 87.2%. Hematomas could be satisfactorily and safely evacuated at any stage. Cerebral perfusion pressure was increased by 20 mm Hg during surgery.

Cerebral Hemorrhage↗
PubMed1989

Amino acid sequence of pheromone-biosynthesis-activating neuropeptide (PBAN) of the silkworm, Bombyx mori.

We have isolated two distinct pheromone-biosynthesis-activating neuropeptides (PBAN), named PBAN-I and -II, as fully oxidized forms of Met residues from adult heads of the silkworm, Bombyx mori. PBAN-I was identical with the PBAN which we had isolated before. The complete amino acid sequence of PBAN-I, a total of 33 amino acid residues, was determined as H-Leu-Ser-Glu-Asp-Met-Pro-Ala-Thr-Pro-Ala-Asp-Gln-Glu-Met-Tyr-Gln-Pro-As p-Pro- Glu-Glu-Met-Glu-Ser-Arg-Thr-Arg-Tyr-Phe-Ser-Pro-Arg-Leu-NH2. Synthetic PBAN-I after oxidation with H2O2 was chromatographically identical with the isolated PBAN-I. Examination of PBAN activity of synthetic analogues indicated that the carboxyl-terminal portion of PBAN-I was important for biological activity.

Amino Acid Sequence↗
PubMed1989

Serum fatty acids and fish intake in rural Japanese, urban Japanese, Japanese American and Caucasian American men.

To examine the relationship of fish intake with serum fatty acids cross-culturally, we surveyed a total of 136 men aged 34 to 55 years in four different populations: rural Japanese (RJ), urban Japanese (UJ), Japanese Americans (JA), and Caucasian Americans (CA). Mean levels of estimated total fish intake per day were 124.9 g in RJ, 70.8 g in UJ, 45.7 g in JA, and 32.3 g in CA. The percentage of total serum fatty acids contributed by omega-3 polyunsaturated fatty acids in these populations was 11.8% in RJ, 9.0% in UJ, 3.4% in JA and 2.5% in CA. Means of omega-3 fatty acids and intake of fish were correlated at the population level; this relationship was strongest when intake of dark-meat fish was considered (n = 4, r = 0.979, p = 0.02). Within each population, except for UJ, individual omega-3 fatty acid levels and dark-meat fish intake were significantly associated (p less than 0.05). A 20 g increase in dark-meat fish consumption was associated with an estimated relative increase in omega-3 fatty acid content of serum by 0.76% in RJ, 0.75% in UJ, 0.64% in JA, and 0.22% in CA. The association between fish intake and serum omega-3 fatty acids at the individual level was not explained by other coronary risk factors. Mortality from coronary heart disease is much lower in Japan than in the US. Population differences in fish intake and serum omega-3 fatty acid levels may contribute to the population difference in the risk of coronary heart disease.

Adult↗
PubMed1989

Stereotactic aqua stream and aspirator for hypertensive intracerebral hematoma.

The stereotactic aqua stream and aspirator (SAS & A) is a modification of the aqua stream and aspirator (AS & A) designed for stereotactic evacuation of intracerebral hematoma. The needle of the new instrument is inserted into the brain through a burr hole by a conventional stereotactic technique and its tip is directed to the center of the hematoma. The hematoma is broken up with a stream of saline solution from a nozzle. Fragments of clot and fluid can then be aspirated piecemeal through the suction tube. The postoperative CT images show successful evacuation of the hematoma, and the clinical evaluation also showed satisfactory results. This instrument can be used safely, without any complications, early after the stroke.

Aged↗
PubMed1989

Trends for coronary heart disease and stroke and their risk factors in Japan.

Disease surveillance and population surveys of risk characteristics in a northeast rural community of Japan (1965 census population, 7,030) are combined in an attempt to relate morbidity and risk factor trends for coronary heart disease and stroke during the last 2 decades. Between 1964 and 1983, the incidence of coronary heart disease (i.e., combined myocardial infarction, angina pectoris, and sudden death) did not change significantly among men and women ages 40-69, and was lower than that for stroke. The incidence of all stroke declined about 60% for both men and women, ages 40-69, with a significant decrease in cerebral hemorrhage for both sexes and in cerebral infarction for men. Between 1963-1966 and 1980-1983, significant upward shifts occurred in the means and distributions of serum total cholesterol and serum total protein in every age and sex group, primarily during the 1st decade. Age-adjusted mean cholesterol levels rose 22 mg/dl to the 1980-1983 mean of 179 mg/dl in men ages 40-69. In women ages 40-69, the mean rose 29 mg/dl to 192 mg/dl. Among nutrients, animal fat intake doubled in men ages 40-59 from 4.5% of daily calories in 1969 to 9.6% in 1980-1983. Animal protein intake also increased, from 5.8% to 7.1%. Most of this increase occurred between 1969 and 1972-1975 and may be attributable to an increased intake of meat, eggs and dairy products. From 1963-1966 to 1980-1983, mean relative weight index rose significantly for all age-sex groups except men ages 50-69. Mean systolic and diastolic blood pressure levels declined for every age-sex group, with a 15-mm Hg age-adjusted decrease in systolic, 4-mm Hg decrease in diastolic pressure among men ages 40-69, and a 11-mm Hg systolic and 4-mm Hg diastolic decrease for women. Two cohorts of men and women ages 40-69 at baseline were followed for disease incidence: an early cohort (2,257 persons) followed from 1963-1966 to 1973 and a later cohort (2,711 persons) followed from 1972-1975 to 1983. In these cohorts, significant risk prediction for cerebral hemorrhage and infarction was obtained with blood pressure level and end organ effects in the electrocardiogram and fundus photographs. Serum cholesterol was inversely associated with cerebral hemorrhage in the early cohort but not in the later.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

[Removal of hypertensive intracerebral hematoma with stereotactic aqua-stream and aspirator (SAS & A)].

The stereotactic aqua-stream and aspirator (SAS & A) was a modification of the aqua-stream and aspirator (AS & A) in order to remove hypertensive intracerebral hematoma. The newly designed needles were held with an adaptor to any kind of Leksell's, Patil's, UT's, Sugita's, or Komai's stereotactic equipment. The needles were stereotactically inserted into the center of the hematoma cavity through a burr-hole. The needles were composed of an outer tube and two inner tubes. The inner tubes were arranged parallel with each other. One was an irrigation tube of 0.1 mm in inner diameter, the other was a suction tube of 2 mm in outer diameter. The blood clot was sucked through a window of the outer tube by the aspirator and incarcerated there soon after. The incarcerated blood clot was crushed by a small streak of saline solution from the nozzle of the irrigation tube. Crushed clot and fluid were sucked through the suction tube. The extent of evacuation of the hematoma was evaluated by CT scans during stereotactic surgery. In all 10 cases of hypertensive intracerebral hematoma, 73-98% of hematoma content was removed. Disturbances of consciousness recovered soon after the surgery. Aphasia and hemiparesis improved later. Hard clot could be removed completely and safely by this new instrument, SAS & A, at an early stage after a stroke, because of the crushing and washing action.

Aged↗
PubMed1988

[AS & A (aqua-stream and aspirator) in neurosurgery: comparison with laser and CUSA].

A new instrument, the aqua-stream and aspirator (AS & A) is useful and safe for microscopical neurosurgery. The apparatus is simple and small. The handpiece is small and light as well as being easy to manipulate. Sterilization is easy and safe. Both streaming and aspirating tubes of AS & A are thin, so that operative field is not obstructed by the operative microscope. The operative field is kept dry and clean by means of washing the work of AS & A. It is economical, because less gas and saline solution than usual are needed during the usual craniotomy (a one liter soft bottle). It is superior to laser and CUSA for the removal of deeply seated soft tumors.

Adolescent↗