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Biomedical subjects

T Kanno

Publications and source records attributed to T Kanno.

At least 415 records · Page 23Linked to original sources
PubMed1989

The physiology and cell biology of paraneurons.

This paper reviews the sequence of events in stimulus-secretion coupling in neurons and paraneurons which can be divided into three main steps: the reception of the stimuli, the conduction of excitation, and the extrusion of messenger substances. One physiological criterion of the paraneuron is that its conductile region is believed to be short enough to transmit the net electrogenesis to the output portion. This contrasts with the neuron in which the depolarization in the input region can initiate spikes which in turn propagate via the axonal membrane to the output portion. The final step of the coupling, the extrusion of the secretory products by exocytosis, is common between neurons and paraneurons. The intracellular messengers acting rather directly in exocytosis are [Ca2+]c and diacylglycerol; both of these seem to be under physiological control. An increase in [Ca2+]c may also act on mitochondria to accelerate the synthesis of ATP, which may be used as the principal energy source and substrate for diacylglycerol-induced protein phosphorylation. In contrast to the common mechanism in the extrusion step of messenger substances, there is a wide diversity in the reception step in the variety of chemical and physical stimuli. This diversity is recognized not only among various neurons and paraneurons but also among the same type of cell in different species and at different stages of adaptation.

Animals↗
PubMed1989

Excitation of both slowly and rapidly adapting pulmonary stretch receptors attenuates tachypnea induced by ammonia.

To elucidate the mechanism of attenuating the ammonia-induced tachypnea, the present study examined the discharge patterns and rates of slowly adapting pulmonary stretch receptors (SARs) and rapidly adapting pulmonary stretch receptors (RARs) in relation to the change in respiration produced by ammonia inhalation in anesthetized, spontaneously breathing rabbits. Extracellular action potentials of these two receptors were recorded at the peripheral cut-end of the left vagus nerve. A prolongation of expiration following ammonia inhalation occurred during the discharge of receptors increased continuously, particularly when the level of the discharge rate during expiration reached to approximately 20-fold, and under such circumstances the respiratory response was regularly associated with gasps. On the other hand, RARs increased their activity during only inspiration; this increased activity correlated with augmentation of inspiration. Furthermore, the prolongating effect of expiration due to ammonia inhalation was not observed after surgical denervation of the remaining right vagus nerve. These results suggest that vigorous stimulation of the SAR activity induced by ammonia inhalation can elicit a prolongation of expiration possibly resulting from augmentation of the Hering-Breuer inflation reflex and that augmentation of the increased RAR activity after ammonia inhalation counteracts the Hering-Breuer inflation reflex to shorten inspiration. Therefore, it is conceivable that strong stimulation of the SAR activity after ammonia inhalation counteracts the ammonia-induced tachypnea.

Action Potentials↗
PubMed1989

[Controlled prospective trial to evaluate Syosakiko-to in preventing hepatocellular carcinoma in patients with cirrhosis of the liver].

A controlled prospective study was conducted to evaluate the potential of Syo-saiko-to (Xiao-Chai-Hu-Tang) for the prevention of hepatocellular carcinoma (HCC). Pairs of patients were matched for age, sex, presence of HBs antigen and the scores of the severity of liver dysfunction from 260 cirrhotic subjects. We randomly assigned each patient to receive either a conventional medicine (control group), or 7.5 g/day of Syo-saiko-to (trial group). The patients were monitored during 34 months of treatment, and the incidence of HCC in the two groups were compared. Seventeen patients were found to have HCC in the control group, and nine were found to have HCC in the trial group. The incidence of HCC was significantly lower in the trial group. The results of this study suggested that Syo-saiko-to may prevent or delay the emergence of latent HCC in patients with cirrhosis of the liver.

Adult↗
PubMed1989

[A method for the determination of cytosolic aminopeptidase in serum and its usefulness for clinical application. Selection of inhibitors for membrane-bound aminopeptidase and cystyl aminopeptidase].

A method for the determination of cytosolic aminopeptidase (EC 3.4.11.1; C-AP) in serum was developed. At first, more specific and adequate inhibitor for other serum peptidases, such as membrane-bound aminopeptidase (EC 3.4.11.2; arylamidase, AA) and cystyl aminopeptidase (EC 3.4.11.3; CAP) was selected from 1,10-phenanthroline derivatives. The compound, 4,7-dimethyl-1,10-phenanthroline (4,7-DMP) is one of the most effective inhibitor for AA and CAP, and it inhibits completely these enzymes at the concentration of less than 0.4 mmol/l. C-AP in serum at an optimum pH of 8.0 in the assay using L-leucine amide (LA) as the substrate had no inhibitory effects at the concentration of more than 0.4 mmol/l of 4,7-DMP. The results with the proposed method correlated with those with a conventional electrophoretic method. The proposed method hence is a specific and easily available assay for C-AP in serum. The further analysis of C-AP using this method would promise the establishment of clinical assessment of the enzyme.

Aminopeptidases↗
PubMed1989

[Crossed cerebellar diaschisis in hydrocephalus--a case report].

A case of hydrocephalus in which a crossed cerebellar diaschisis with single photon emission CT (SPECT) using 123I-iodoamphetamine (123I-IMP) disappeared by a ventriculo-peritoneal shunting operation, was reported. A 54-year-old female had a clipping surgery for a aneurysm of the left middle cerebral artery on April 9, 1987. Post-operatively, she had a transient mild aphasia. Cerebral blood flow (CBF) study with 123I-IMP-SPECT had showed low perfusion in the left frontal and temporal lobe. But after a month, clinical symptom and CBF findings had improved. She had been doing well after the discharge until October, 1987, when she developed disorientation. CT on re-admission showed the ventricular dilatation with periventricular low density (left greater than right). 123I-IMP-SPECT study showed the crossed cerebellar diaschisis which was a low perfusion in the left frontal, temporal, parietal, thalamus, basal ganglionic area and in the opposite cerebellum. A ventriculo-peritoneal shunting operation was performed which brought the disappearance of the crossed cerebellar diaschisis and the clinical improvement. The phenomenon of crossed cerebellar diaschisis has been reported in a lot of literatures. However, those diseases were located in unilateral supratentorium. It has been speculated that crossed cerebellar diaschisis is the transneural metabolic change through the cortico-ponto-cerebellar pathway by supratentorial lesion. Crossed cerebellar diaschisis in hydrocephalus has not been reported so far.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamines↗
PubMed1989

[SPECT measurement of cerebral hemodynamics in transient ischemic attack patients--evaluation of pathogenesis and detection of misery perfusion].

To evaluate the cerebral hemodynamics and the pathogenesis by regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV), 42 transient ischemic attack (TIA) patients and 9 normal volunteers were studied using SPECT. We classified these patients into Group A (n = 23: no occlusion or stenosis of the internal carotid or middle cerebral artery; non large vessel disease) and Group B (n = 19: chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery; large vessel disease). We obtained rCBF with 133Xe inhalation and rCBV with 99mTc-red blood cells. Of 9 normal volunteers aged 43-70 yr (mean age 59.8 +/- 8.3 yr), the mean rCBF was 45.8 +/- 5.1 (ml/100 g brain/min), the mean rCBV was 4.0 +/- 0.4 (ml/100 g brain). The examination was done by comparing the values of the affected hemispheres of Group A and Group B patients with the mean rCBF and the mean rCBV of normal volunteers. Eleven out of Group A patients and 15 out of Group B patients showed decreased rCBF. But of those patients, no patients of Group A showed increased rCBV and 6 out of 19 Group B patients showed increased rCBV. Thromboembolic mechanism which is of Group A patients and Group B patients without increased rCBV, and hemodynamic mechanism which is of Group B patients with increased rCBV were considered as the main cause of TIA. Decreased rCBF and increased rCBV in Group B patients can be assumed as the misery perfusion as reported in PET studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Determination of branched-chain amino acids and tyrosine in serum of patients with various hepatic diseases, and its clinical usefulness.

We developed an automated enzymatic method for determination of the branched-chain amino acids (BCAAs; valine, isoleucine, leucine) and tyrosine in serum, and applied it to the clinical evaluation of patients with various hepatic diseases. Analytically, the test results were acceptably precise and reproducible, and correlated well with results obtained with an amino acid analyzer. Clinically, we found that a decrease in BCAAs, an increase in tyrosine, and the BCAAs/tyrosine ratio in serum paralleled the severity of hepatic parenchymal damage. We conclude that this enzymatic determination of BCAAs and tyrosine is simple and convenient enough for routine clinical laboratory use, and that the ratio of BCAAs/tyrosine obtained may be a good indicator of the severity of hepatic disorders.

Adult↗
PubMed1988

Lactate dehydrogenase M-subunit deficiency: a new type of hereditary exertional myopathy.

Three families with a complete deficiency of the lactate dehydrogenase M subunit show exertional myoglobinuria. The response to ischemic forearm work is characteristic in these three families: an increase of venous lactate concentration after ischemic work was not observed and a marked increase of venous pyruvate was found. Glycolysis was markedly retarded in the patient's muscle in the glyceraldehyde 3-phosphate dehydrogenase (GA3PD) step. A significant increases in glyceraldehyde 3-phosphate, dihydroxyacetone phosphate and fructose 1,6-diphosphate were observed. The glycolysis retardation may be attributed to the impaired reoxidation of NADH produced by GA3PD action. The cytosolic fraction of skeletal muscle is rich in alpha-glycerophosphate dehydrogenase. This enzyme reoxidizes the excess NADH and drains triose phosphates from the glycolytic pathway under anaerobic conditions. For this reason, ATP production was significantly impaired and muscle cells were damaged in these patients. Consequently, the cytosolic enzymes and proteins such as creatine kinase and myoglobin were released into the blood stream. Otherwise, patients with a lactate dehydrogenase M-subunit deficiency do not show muscle stiffness and myoglobinuria under ordinary circumstances. They complain of muscle rigidity and sudden myoglobinuria after strenous exercise under anaerobic conditions. Thus, the lactate dehydrogenase M-subunit deficiency does not show any symptoms under ordinary circumstances, but is a latent hereditary disorder, now recognized as a new type of hereditary exertional myoglobinuria.

Adolescent↗
PubMed1988

Increased cytosol aminopeptidase and lactate dehydrogenase in serum originating from lymphocytes in measles and rubella infection.

We determined cytosol aminopeptidase (c-AP; EC 3.4.11.1) and lactate dehydrogenase (LDH) levels in serum; these enzymes are known to originate from lymphocytes in patients with measles and rubella. In patients with measles (n = 19), both enzyme levels increased markedly with the onset of rash: mean (+/- SD) c-AP was 269.7 +/- 103.5 U/L and LDH was 1149.5 +/- 255.2 U/L. In patients with rubella, activities of both enzymes increased mildly: c-AP (n = 18) was 81.6 +/- 24.4 U/L and LDH (n = 13) was 674.0 +/- 168.8 U/L. Increased c-AP and LDH levels in patients with measles and rubella presumably originate from the destruction of infected, activated lymphocytes, especially T lymphocytes.

Alanine Transaminase↗
PubMed1988

Bilateral giant intracavernous aneurysms. Technique of unilateral operation.

We report a case of bilateral intracavernous giant aneurysms of which the right side was clipped by direct surgery. Our case was a 74-year-old woman who developed bilateral abducens palsy. Computed tomography and angiography showed bilateral intracavernous giant aneurysms. This patient was followed up in the outpatient clinic. She developed headache and right trigeminal neuralgia 2 years later. The trigeminal pain was quite severe and very disturbing to her. Repeat angiography showed an increase in the size of the aneurysms. An operation was carried out after a balloon Matus test monitoring electroencephalogram, somatosensory evoked potential, and clinical symptoms. The cavernous sinus was opened and the aneurysm was clipped. There was no postoperative complication except right ophthalmoplegia which resolved after 3 months. Headache and trigeminal neuralgia also disappeared.

Aged↗