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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 919 records · Page 51Linked to original sources
PubMed1989

[Early pathophysiological findings in experimental concussion in rabbits].

Early neurophysiological changes and pathological findings were studied following experimental cerebral concussion in rabbits. The animals were lightly anesthetized and subjected to occipital trauma with a pendulum impactor. Experimental concussion was defined as fulfillment of at least two of the three following criteria: apnea for more than 10 seconds, absence of the light reflex for more than 10 seconds, and bradycardia or tachycardia (less than 50% or more than 10% of the preimpact rate, respectively). There were 13 cases of lethal concussion, 16 of nonlethal concussion, and 15 of nonconcussion. The resultant head acceleration ranged from 250 to 1660 G and its duration was 0.8 to 5.5 msec. During the first 30 seconds after impact, electroencephalographic activity showed little change even in cases of lethal concussion, but slowed over the next several minutes due to respiratory suppression. The duration of apnea in cases of nonconcussion was under 9 seconds and, in cases of nonlethal concussion, averaged 21 seconds. Five of the rabbits with lethal concussion were apneic throughout the observation period, and the remaining eight exhibited apnea for an average of 46 seconds after impact. The light reflex was absent for less than 9 seconds in nonconcussion cases and for an average of 71 seconds in cases of nonlethal concussion. One animal with lethal concussion exhibited absence of the light reflex throughout, and the remaining 12 animals for an average of 39 seconds. Bradycardia was seen in 15 cases of nonlethal and two cases of lethal concussion. Six rabbits with lethal concussion had tachycardia. Two animals without concussion showed bradycardia and the remainder showed no change.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Ultrastructural findings of the macaque monkey vestibular ganglion cells.

The fine structure of macaque monkey vestibular ganglion cell was studied under the electron microscope. Over 400 serial sections enabled us to observe the entire surface of 114 ganglion cells. Eight ganglion cells were characterized by loose myelin layers. The compact myelin sheath was not demonstrated around any area of the perikaryon in these eight cells. The rest of the cells exhibited both compact and loose myelin layers around one perikaryon. All ganglion cells were bipolar in this study. The initial dendritic process was generally thinner and shorter than the initial axonal process. Both compact and loose myelin sheaths were demonstrated around the initial axonal and dendritic segment as far as the first node of Ranvier, after which all processes became thickly myelinated. This study demonstrated two types of cells: myelinated and unmyelinated. However, there is no obvious size or histological difference between the perikarya of different types of ganglion cells.

Animals↗
PubMed1989

[Application of immunotoxin in cancer therapy; its usefulness and problems in the future].

Highly specific anti-human colorectal carcinoma monoclonal antibody(A7) was developed by fusion of mouse myeloma cells with mouse spleen cells immunized by colon cancer cells. Neocarzinostatin (NCS) was bound to A7 preserving both antibody and drug activities. This conjugate (A7-NCS) was applied for clinical trial. No serious side effects were reported, and half of the eight patients with metastatic liver tumor responded to A7-NCS well. To overcome the variety in the expression of tumor-specific antigen on tumor cells, new types of conjugates were developed. Mitomycin C(MMC) was bound to Dextran sulphate. And this conjugate (M MC-Dex) was bound to A7 with the expectation that MMC would release from Dextran that was delivered to the surface of the cancer cells. This type of conjugate would be effective not only against cancer cells that express antigens detected by A7 but also against any cells around cancer cells detected by A7. The possibility and problems in cancer therapy using immunotoxin are discussed.

Antibodies, Monoclonal↗
PubMed1989

[Changes of antibody and splenic plaque forming cell responses to mutans streptococci in the rats infected with S. sobrinus 6715].

The study was undertaken to examine the changes in humoral IgM, IgG and IgA antibodies and splenic plaque forming cell responses against Streptococcus sobrinus 6715 in rats infected with the same mutans streptococci. The serum samples were collected every week for 24 weeks after infection (20 day old, Sprague Dawley rats). Humoral anti-S. sobrinus 6715 IgG and IgA antibodies were determined by an enzyme-linked immunosorbent assay. In the separate experiment, rat splenic IgM, IgG and IgA anti-trinitrophenyl (TNP) conjugated S. sobrinus plaque-forming cell (PFC) responses were also determined from 1 to 12 weeks after the infection. The results obtained were as follows: 1. From 1 to 4 weeks after infection, a slight increase in serum IgG anti-S. sobrinus antibody response was observed in the group of rats infected with S. sobrinus 6715 when compared with the non-infected rat group. However, beyond the 5th week, there was no difference in serum antibody responses between these two groups. 2. Infected rats showed a 2-9 times higher serum anti-S. sobrinus IgA antibody response than those of uninfected rats for 6 weeks after the infection. After this period just as with the IgG response, no difference in the IgA titers was found between these two groups. 3. Splenic IgM, IgG and IgA anti-TNP-S. sobrinus PFC responses showed a remarkable decrease shortly after the infection. These results suggest that the infected rats would gradually acquire oral tolerance to S. sobrinus antigen after the infection.

Animals↗
PubMed1989

[Multifocal gliomas in cerebral hemisphere associated with von Recklinghausen's disease: case report].

A case of intracerebral multifocal gliomas with von Recklinghausen's disease is reported. A 12-year-old boy was admitted to our hospital with an episode of convulsive attacks which were uncontrolled by anticonvulsants. CT scan and MRI revealed small well circumscribed tumors in the left frontal cortex and left parietal subcortex. Both of the tumors revealed low density in plain CT scan and low intensity in T1 weighted MRI. The vascularity of these tumors was poor in cerebral angiography. In other words these tumors were of a similar nature. The histology of the frontal tumor, which was totally removed surgically, showed typical pilocytic astrocytoma. The other tumor in the left parietal subcortex must also be included in the category of low grade glioma. In the sixth month after the operation, we could find neither recurrence of the frontal glioma nor enlargement of the parietal tumor, on CT and MRI findings. Immunohistochemically, the outer portion of the Rosenthal fiber in this tumor was positive for GFAP and S-100 protein, but the inner portion was negative, because the GFAP and S-100 protein there had degenerated. The cytoplasm of this tumor's cell was abundant with mitochondria and Golgi's bodies compared to the fibrillary astrocytoma. This case may be the first case of multifocal gliomas in the same cerebral hemisphere. We suggest that multifocal gliomas grow naturally, and over the years, tumors combine with each other and finally constitute a large type diffuse glioma.

Astrocytoma↗
PubMed1989

[Magnetic resonance image of pituitary adenoma--comparison of functioning tumor and non-functioning tumor].

Thirty three cases of pituitary adenoma were examined by MRI with 0.15 T system. Eight cases of functioning tumor showed iso-minimally low intensity, and 10 cases of non-functioning tumor did slightly-markedly low intensity on IR image. Functioning tumor cells contain well-developed rough-surfaced endoplasmic reticulum, Golgi complexes and numerous secretary granule, so that bound water more increases and T 1 relaxation time less prolongs in functioning tumor than in non-functioning tumor. Two cases of functioning tumor disclosed slightly low intensity on IR image because of its poor stroma. It is necessary to know the exact bleeding time so as to measure the signal intensity in pituitary apoplexy case. Microadenoma appeared spotty hypointensity and upward convexity of superior surface of the gland on IR image.

Adenoma↗
PubMed1989

Bilateral internal auditory canal enlargement without acoustic nerve tumor in von Recklinghausen neurofibromatosis.

The common (and definitive) intracranial tumors in patients with one form of neurofibromatosis (NF), bilateral acoustic NF (NF-2), are bilateral acoustic neuromas. In this study, we present 2 cases with what appears to be another form of NF, namely, NF-1, who showed bilateral enlargement of the internal auditory canals. Bilateral caloric responses were remarkably impaired in both cases; a unilateral sensorineural hearing loss was observed in 1. No tumor was demonstrated in the enlarged internal auditory canals in either case. Although the pathophysiology remains uncertain, some patients with NF-1 show abnormal cochleovestibular function in association with bilateral internal auditory canal enlargement without an acoustic tumor.

Child↗
PubMed1989

[Report of a case of Herpes zoster].

Herpes Zoster is a viral disease of the skin and mucosa characterized by grouped vesicula eruptions and neuralgic pain along a peripheral nerve. A case of Herpes Zoster in the right region along the second and third trigeminal nerve branches of a 24-year-old male was reported. The first disorder appeared as a grouped vesicular eruption in the center of the lower lip. This was followed by a cutaneous lesion in the area of the right second trigeminal nerve branch. From the first day of hospitalization, the patient began receiving a daily dose of 2500mg of immunoglobulin. The administration of immunoglobulin, cured the oral and cutaneous lesion.

Adult↗
PubMed1989

Granular cell tumor of the stomach coincident with two early gastric carcinomas.

In a 64-yr-old Japanese man, granular cell tumor of the stomach plus two early gastric carcinomas were detected. The granular cell tumor was a 1.5 x 1.5-cm submucosal nodule located in the posterior wall of the fundus. The mucosa adjacent to the granular cell tumor showed two well-differentiated adenocarcinomas restricted to the mucosa, but there was no continuity among these three conditions. This seems to be the first report of this type of association. Immunohistochemical study revealed S-100 protein in the component cells of the granular cell tumor, thereby supporting the proposal that this granular cell is derived from Schwann cells.

Adenocarcinoma↗
PubMed1989

[A study on the estimation of prevalence of epidermolysis bullosa in Japan].

An estimation of the prevalence of epidermolysis bullosa was carried out in Japan. A questionnaire was sent by mail to the departments of dermatology and pediatrics in 644 main hospitals throughout Japan requesting confirmation of the number of epidermolysis bullosa cases experienced. The response rate was 63.0% or 406 hospitals. Based on the secondary questionnaire survey, we confirmed 393 cases of epidermolysis bullosa, and then divided them into the five following groups: "simplex" type 182 (48.2%), "junctional" type 23 (6.0%), "dominant dystrophic" type 72 (18.7%), "recessive dystrophic" type 109 (28.2%), unclassified 7 (1.8%). Using the respondent rate by geographic region and clinical department, the estimated prevalence of each type of epidermolysis bullosa was calculated as follows: "simplex" type 340-470 (0.29-0.40 per 100,000 population), "junctional" type 18-24 (0.015-0.020), "dominant dystrophic" type 130-180 (0.11-0.15) and "recessive dystrophic" type 180-250 (0.15-0.21). The total number of epidermolysis bullosa patients in Japan was estimated as being more than 670 in 1983.

Epidermolysis Bullosa↗
PubMed1989

Papillary adenoma of the gallbladder associated with regurgitation of pancreatic juice through abnormally shaped union. Case report.

In a 52-year-old woman papillary adenoma of the gallbladder was associated with regurgitation of pancreatic juice into the biliary tract via an abnormally shaped union, not a long common channel. The condition was demonstrated by endoscopic retrograde cholangiography and histologically confirmed. Extended cholecystectomy and lymph-node dissection were performed.

Biliary Tract↗
PubMed1989

Activations of the Ca dependent K channel by Ca released from the sarcoplasmic reticulum of mammalian smooth muscles.

In mammalian smooth muscles, the outward K current recorded using the whole cell voltage clamp or patch clamp methods can be classified into the Ca-dependent and independent K currents. The former is sub-classified into the extra- and intra-cellular Ca dependent K current. The intra-cellular Ca dependent K current has a close relation to Ca released from the sarcoplasmic reticulum, i.e. Ca released by inositol 1,4,5-trisphosphate (InsP3), ryanodine or Ca ionophores (A23187 or ionomycin) modify the appearance of the K current. The transient (Ca dependent) outward current evoked by depolarization pulses, as measured using the whole cell voltage clamp method, is closely related with after-hyperpolarization of the action potential as recorded using the microelectrode method and is postulated to be due to activations of the Ca-induced Ca release mechanism in the sarcoplasmic reticulum. The oscillatory (Ca dependent) outward K current is closely related with the amount of Ca released from the sarcoplasmic reticulum during the long depolarization induced by electrical stimulation (command pulse) or applications of Ca releasers such as InsP3 or ryanodine. In this review, the Ca dependent K current recorded from smooth muscle cells is compared with the influx and release of Ca.

Animals↗
PubMed1989

[An intracranial collision tumor composed of intrasellar gangliocytoma and pituitary adenoma].

The authors report a rare case of collision tumor composed of intrasellar gangliocytoma and pituitary adenoma. The patient was a 56-year-old woman, who had a mild acromegalic feature and slightly elevated plasma GH level. But she had no abnormal neurological findings. Transsphenoidal microsurgery was performed and an intrasellar tumor was totally removed. After the operation, plasma GH level decreased to within normal level. She was discharged with no neurological deficit. Histological examination showed two components. One of them was gangliocytoma composed of many large, and often binucleated cells with Nissl substance. The other had the appearance of chromophobe adenoma. In this part, some of the cells showed positive stain for GH. The clinical and histological features of this lesion are discussed and compared with 31 other cases of intrasellar ganglioglioma or gangliocytoma.

Adenoma, Chromophobe↗
PubMed1989

Aplastic anemia. Immunosuppressive therapy in a multi center trial in Japan.

We evaluated the biologic characteristics and effectiveness of immunosuppressive agents in patients with a severe form of aplastic anemia in a multicenter study. Treatment with a bolus of methylprednisolone (mPSL) was associated with a good response and a partial response in 19.4% and 1.4% of the patients, respectively. In contrast, two kinds of antilymphocyte globulin (ALG) were effective for 9.4% and 15.6% of the severe form of aplastic anemia, and two kinds of antithymocytoglobulin (ATG) were effective in 30.8% and 37.2% of the patients, although the difference between ALG and ATG was not statistically significant. We recommend that patients diagnosed as having severe aplastic anemia should be referred as soon as possible for treatment with immunosuppressive agents or bone marrow transplantation, the latter depending on disease severity, age, and potential availability of an HLA-identical sibling donor.

Adolescent↗
PubMed1989

[Surgical treatment of bilateral spontaneous pneumothorax].

88 cases of bacterial spontaneous pneumothorax, 20 cases, occurred same time and 68 cases, occurred different time, were treated in our Department of Thoracic Surgery from 1975 to July 1987, and represented 16.6% of all cases of spontaneous pneumothorax. The characteristics of bilateral spontaneous pneumothorax, occurred same time, were as follows; 1) frequent in teens, 2) often occurred with history of unilateral spontaneous pneumothorax, 3) slightly collapsed. For the treatment of bilateral spontaneous pneumothorax, occurred same time, bilateral thoracotomy was necessary. The characteristics of bilateral spontaneous pneumothorax, occurred different time, were as follows; 1) frequent in the twenties, 2) often occurred the other side after unilateral thoracotomy within a year. For the treatment of bilateral spontaneous pneumothorax, occurred different time, if the patient is under 20 thoracotomy must be carried out, but if the patient is over 20 at the side of pneumothorax must be operated.

Adolescent↗