PubMed Health⌕ Search

Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 1,045 records · Page 58Linked to original sources
PubMed1987

[Missile therapy using monoclonal antibody drug conjugates in colorectal carcinoma].

For targeting chemotherapy of colorectal carcinoma, mitomycin C (MMC) and neocarzinostatin (NCS) were covalently bound to monoclonal antibody A7 which is highly specific to human colon cancer. The in vitro cytotoxic effects of the conjugates A7-MMC and A7-NCS on SW1116 were 77 times and 4 times stronger than those of the free MMC and free NCS, respectively. An in vivo study in nude mice bearing human colon carcinoma revealed that monoclonal antibody A7 alone had no effect, and that A7-MMC and A7-NCS had greater inhibitory effects than the free MMC and NCS, respectively. Thirty-five patients with carcinoma of the colon and rectum including 6 with postoperative liver metastasis, one with postoperative lung metastasis and one with postoperative peritoneal metastasis, were given the A7-NCS conjugate consisting of between 15 and 90 mg of antibody and between 1,000 and 6,000 units of NCS. Immunoperoxidase study of resected specimens revealed selective localization of NCS in the cancer cells. The conjugate had no serious adverse effects. Five of the six patients with postoperative liver metastasis responded favorably to the conjugate, showing a decrease in tumor size on CT scan or relief of pain. The conjugate was of no benefit to patients with multiple lung metastasis or peritoneal metastasis. The effect on other patients with surgically resected carcinoma remains to be determined by a follow-up study.

Adenocarcinoma↗
PubMed1987

Actions of flunarizine, a Ca++ antagonist, on ionic currents in fragmented smooth muscle cells of the rabbit small intestine.

Actions of flunarizine on the Ca++ inward and K+ outward currents were investigated using fragmented smooth muscle cells (smooth muscle ball) prepared from the longitudinal muscle layer of the rabbit ileum. Flunarizine dose dependently inhibited the Ca++ inward current (ID50 = 1.4 microM). The decay of the inward current consisted of two exponentials and flunarizine had no effect on these time constants. When command pulses (100 msec; stepped up to 0 mV from -60 mV) were applied every 20 sec, the peak amplitude of the inward current remained unchanged. Flunarizine above 0.3 microM slowly inhibited the peak amplitude of inward current, in a voltage- and use-dependent manner. Intracellular perfusion of flunarizine, up to 100 microM, did not modify the peak amplitude of the inward current. This Ca++ antagonist also inhibited the K+ outward current, in a dose-dependent manner (ID50 = 5.8 microM) and accelerated inactivations of this current. When the command pulses (300 msec; stepped up to +20 mV from -60 mV) were applied repetitively every 20 sec, amplitudes of the K+ outward current were not affected. However, flunarizine, above 1 microM, reduced the peak amplitude of the K+ outward current slowly. These results indicate that although flunarizine possesses the property of a Ca++ antagonist, it also inhibits the K+ outward current, in a manner different from that observed on the Ca++ inward current.

Animals↗
PubMed1987

[Fusiform aneurysm of the vertebral artery presenting with foramen magnum syndrome: a case report].

A 33-year-old male developed stiffness of the left neck and pain of the left shoulder two years previously. Six months prior to admission, he noticed tingling sensation of the left 2nd, 3rd and 4th fingers and motor weakness of the left hand, both of which gradually progressed. On admission, positive neurological findings were neck pain on dorsal extension, left hemiparesis more advanced in the upper limb, diffuse muscle atrophy of the left upper limb, hyperreflexia of the left upper and lower limbs with positive Babinski sign and dysesthesia corresponding to the left C3-T5 sensory dermatomes. Enhanced CT and Metrizamide CT myelography showed a large extra- and intra-dural mass from the C1 segment to the medulla oblongata on the left. Angiography disclosed a fusiform aneurysm of the left vertebral artery. Proximal ligation of the left vertebral artery was performed. Postoperatively, clinical signs were markedly improved and shrinkage of the aneurysm was demonstrated on postoperative Metrizamide CT myelogram. Pathogenesis of diffuse muscle atrophy of the left upper limb was undetermined, but was probably not due to disturbance of the anterior spinal artery because of good visualization of the artery on the angiogram. Indication of the proximal ligation of the vertebral artery with an aneurysm was discussed.

Adult↗
PubMed1987

[A case of clear cell carcinoma of the minor salivary gland].

A rare case of clear cell carcinoma of the palatal salivary gland in a 69-year-old man is reported. Histopathologically, nests and cords of tumor cells, which showed predominantly clear cytoplasms, and occasionally eosinophilic cytoplasms, proliferated on the overlying epithelium and capsules of the fibrous connective tissue. The clear cell cytoplasms were found to be PAS positive, diastase soluble, and Alcian-blue negative, indicating the presence of glycogen. Ultrastructurally, the tumor cells were found to contain glycogen and cytoplasmic filaments in various proportions. These observations suggest that clear cell carcinoma is myoepithelial in origin.

Adenocarcinoma↗
PubMed1987

[Therapeutic problems in aged patients with intracranial aneurysms].

In a series of 404 patients with intracranial saccular aneurysm, 61 were over 65 years of age. Ten of these aged patients had no surgery. The operative mortality in the aged patients was 11.8%. While the mortality rate in patients below 65 years was 6.1%. The main complication following intracranial surgery for aneurysm consisted of cerebral infarction due to vasospasm, hydrocephalus, intracranial hematoma and general complications. The incidence of angiographical vasospasm was 22.6% in the aged patients and 43.6% in the young patients. There is no significant difference in vasospasm following subarachnoid hemorrhage between the aged and young patients. Cerebral infarction occurred in 27.5% of the aged patients and in 24.6% of the young patients. Severe cerebral infarction was found in 92.9% of the aged patients and in 58% of the young patients. Vasospasm resulted in broad cerebral infarction significantly more frequently in the aged patients, but cerebral infarction proved was non-fatal in the aged patients. Ventricular dilatation detected by CT was found in 33.3% of the aged patients and in 24.2% of the young patients. In patients with ventricular dilatation, 82.4% of the aged patients needed ventriculo-peritoneal shunt (V-P shunt). On the other hand, 39.3% of the young patients had V-P shunt. There was no significant difference for ventricular dilatation detected by CT between the aged and young patients. The aged patients depended on V-P shunt significantly more than did the young patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[EEG topographic changes of brain abscesses in children].

EEG topography was investigated before and after surgical treatment in 4 patients with brain abscess aged from 5 to 13 years. According to the recording technique designed by Matsuoka and Ueno, the recorded EEG for each 5 seconds was analyzed to obtain square roots of power spectra for each band of delta (2-3.8 Hz), theta (4-7.8 Hz) and alpha (8-12.8 Hz) which were then added for the 60-seconds duration of each trial. After that, numerical matrix presenting the topographic distribution of spectral energy of each band were constructed and displayed as color images. In addition, the EEG topographies of brain abscesses were compared with the CT scans simultaneously obtained. In all of four cases before surgical treatment of the brain abscess, the location of the focal delta wave on the EEG topography was more closely related to the site of brain abscess comparing with its correlation between the location of the delta focus on the conventional EEG and the site of brain abscess. In contrast, as for the theta wave, there was no prominent correlation to the site of the brain abscess. In the early stage of 10-15 days after aspiration of the brain abscess, the most characteristic change of the EEG topography was an approximately 25% reduction of the maximum equivalent voltage of delta band with associated disappearance of the sharply located focal delta wave being noted before aspiration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Immunoreactive neuromedin B and neuromedin C: distribution and molecular heterogeneity in rat and human tissue extracts.

Immunoreactive neuromedin B and neuromedin C were characterized and measured in rat and human tissue extracts, using radioimmunoassay combined with gel filtration and high performance liquid chromatography in order to clarify tissue distribution and molecular structure. There are two distinct systems of bombesin-like peptide found in rat and human tissue. The neuromedin B family, including neuromedin B and big neuromedin B, is a major bombesin-like peptide in the brain; the neuromedin C gastrin-releasing peptide family is found mainly in the alimentary tract. Neuromedin B is the major and big neuromedin B the minor constituent of central nervous neuromedin B immunoreactivity. Gastrointestinal neuromedin C immunoreactivity is composed chiefly of neuromedin C in rats, and two N-terminally extended forms of neuromedin C including gastrin-releasing peptide in man. It is probable that molecular heterogeneity reflects species variation.

Animals↗
PubMed1987

Selective and long-lasting inhibitory actions of the dihydropyridine derivative, CV-4093, on calcium currents in smooth muscle cells of the rabbit pulmonary artery.

Effects of CV-4093, a newly synthesized dihydropiridine type of Ca antagonist, on membrane currents in enzymatically dispersed single smooth muscle cells of the rabbit main pulmonary artery were investigated using the single electrode voltage clamp method. Three types of membrane currents were evident, i.e., Ca and Na inward and K outward currents. CV-4093 potently inhibited the Ca inward current, as compared to findings with other currents. When the potential was at -60 mV, CV-4093 consistently inhibited the Ca current evoked by depolarization to 0 mV. However, a low concentration of CV-4093 (1-3 nM) enhanced the Ca current evoked by the depolarizing pulse of -20 mV, when the membrane potential was held at -80 mV. Inhibition of the Ca current induced by CV-4093 developed slowly and over 10 min was required to reach the maximum inhibition. Changes in the frequency of the depolarizing pulse did not modify the rate of inhibition induced by CV-4093. The inhibition was not restored by washout of the drug for over 40 min, and hyperpolarizations of the membrane did not accelerate the recovery. The IC50 of CV-4093 obtained for the K outward current was 3000 times larger than that obtained for the Ca inward current. CV-4093 apparently has highly selective and long-lasting inhibitory actions on the Ca current in smooth muscle cells of the rabbit main pulmonary artery.

Animals↗
PubMed1987

[Suppressive effect of lentinan on pulmonary metastases in murine tumors].

Lentinan has been shown to have a suppressive effect on the natural pulmonary metastasis of Lewis lung carcinoma, though its effect seems to depend on the timing of the administration. Administration of lentinan after the amputation of tumor was found to be more effective than before administration. Additionally, lentinan also has shown a marked suppressive effect on the pulmonary metastasis of MC-CS-1 fibrosarcoma, a high sensitive tumor for lentinan in any administration examined. These date suggest the usefulness of lentinan in suppressing tumor metastasis.

Animals↗
PubMed1986

Which is responsible for circling behavior in rats, locus coeruleus or dorsolateral pontine tegmentum?

Unilateral electrolytic lesions restricted to the locus coeruleus (LC) in rats did not produce postural asymmetry or circling behavior, while similar lesions in the dorsolateral pontine tegmentum (DLPT) closely ventral to the LC caused a circling behavior toward the contralateral side. The circling behavior was potentiated by intraperitoneal injection of dopamine agonists, apomorphine or methamphetamine, and was abolished by the dopamine antagonist, haloperidol. Neurochemical analysis using a gas chromatographic-mass spectrometric method was made 4, 10 and 20 days after LC coagulation, resulting in a gradual decrease of noradrenaline level in the frontal cortex on the lesioned side. Dopamine content in the striatum in these rats was not significantly affected. Unilateral lesioning of the DLPT produced no significant change in contents of dopamine of homovanillic acid in the striatum or of noradrenaline in the frontal cortex. These results indicate that the LC is not involved in the circling behavior, without a modulatory effect on the dopamine metabolism in the striatum, whereas the DLPT closely ventral to the LC is responsible for circling behavior by subserving as a descending neural pathway conveying striopallidal function on the contralateral side.

Animals↗
PubMed1986

Synergistic antitumor effect of interferon and anti-idiotype monoclonal antibody in murine lymphoma.

Both IFN-alpha and anti-idiotype monoclonal antibody therapy have significant antitumor activity in vivo in a murine B cell lymphoma model. Combination therapy with syngeneic anti-idiotype antibody of the IgG2a or IgG2b isotype (a single i.p. injection of 100 micrograms) and recombinant human hybrid interferon-alpha A/D (10(4) to 10(6) U three times weekly for 3 wk) synergistically increased median survival time in mice challenged with a lethal dose of tumor cells compared with the sum of the median survival times of the two individual treatments. IFN-alpha has direct antiproliferative activity against 38C13 in vitro and enhances in vitro macrophage anti-idiotype antibody-specific cytolysis for IgG2a, IgG2b, and IgG1 isotypes.

Animals↗