Search PubMed⌕ Search

Biomedical subjects

T Itakura

Publications and source records attributed to T Itakura.

At least 181 records · Page 10Linked to original sources
PubMed1986

[Hyperbilirubinemia in neonates associated with total parenteral nutrition].

Clinical studies on the pathogenesis of hyperbilirubinemia (HB) in neonates during total parenteral nutrition (TPN) were performed. From 1971 to 1982, 77 neonates underwent TPN for more than 2 weeks in our institutions. Forty-four of them (57.2%) developed HB during the first one month of life. Twenty eight of 32 patients (87.5%) with dominant infection developed hB, while only 16 of 45 (35.6%) without infection developed HB. Patients with any kind of obstructive intestinal diseases evoked HB more commonly than patients with other diseases. In addition, HB occurred more often in the patients receiving more than 110 kcal/kg/day than those receiving less than that. Gestational ages, birth weights, the duration of TPN and fasting periods had no significant influence on the occurrence of HB.

Age Factors↗
PubMed1985

Chronic subdural hematoma after open heart surgery.

Three cases of chronic subdural hematoma after open heart surgery are reported. In all cases, computed tomography scans revealed subdural accumulations of high density after cardiac surgery. The high-density areas changed into isodensity or low density with mass effect within 2 or 3 weeks. Anticoagulant (heparin) and a tearing of bridging veins after a rapid change of the brain volume by administration of mannitol can be a cause of chronic subdural hematoma. Forty-five to 60 mL of liquefied hematoma was aspirated and the outer membrane of the hematoma cavity was recognized by a trepanation.

Adult↗
PubMed1985

5-Hydroxytryptamine innervation of vessels in the rat cerebral cortex. Immunohistochemical findings and hydrogen clearance study of rCBF.

The role of the central 5-hydroxytryptamine (5-HT) neuron system in cerebral microcirculation of the rat was examined by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies demonstrated 5-HT-immunoreactive nerve fibers along intraparenchymal blood vessels (arterioles, capillaries, and venules). Ultrastructural observation revealed that 5-HT-immunoreactive terminal boutons (0.3 to 1.0 micron in diameter) made contact with the basement membrane of the capillaries. After an intracerebral injection of 5,7-dihydroxytryptamine (5,7-DHT), a neurotoxin to the 5-HT neuron system, no 5-HT-immunoreactive nerve fibers were found around the injection site with immunohistochemical techniques. With the hydrogen clearance method, the 5,7-DHT-injected cortex showed no significant change in regional cerebral blood flow (rCBF) in the presence of normocapnia, but a significant increase in rCBF with hypercapnia, compared with the untreated cortex. These facts strongly suggest that the central 5-HT neuron system has an important role in carbon dioxide reactivity of the cerebral blood vessels.

Animals↗
PubMed1984

A light and electron microscopic immunohistochemical study of vasoactive intestinal polypeptide- and substance P-containing nerve fibers along the cerebral blood vessels: comparison with aminergic and cholinergic nerve fibers.

Vasoactive intestinal polypeptide (VIP)- and substance P-containing nerve fibers were observed in the cerebral blood vessels using an immunohistochemical technique. VIP-containing nerve fibers distributed in a spiral pattern, similar to that of muscle cells. Under electron microscopic observation, VIP-immunoreactive terminals lay close to a muscle cell in the inner layer of the adventitia. In contrast, substance P-containing nerve fibers showed a meshwork pattern in the outer layer of the adventitia. Using both acetylcholinesterase (AChE) staining and VIP immunohistochemistry, AChE-positive and VIP-immunoreactive nerve fibers revealed almost the same distribution in the same specimen. The present data suggest that VIP-containing nerve fibers may play a role in the smooth muscle control of the blood vessels, whereas substance P-containing nerve fibers may not take part in muscle control.

Animals↗
PubMed1984

The effect of fasting and hypocaloric diets on the functional and metabolic characteristics of rat gastrocnemius muscle.

Previous observations have shown that in human subjects with malnutrition and after prolonged fasting, there are characteristic changes in the force-frequency response, relaxation rate and power of muscle during a 30 s stimulus (fatigue). In order to characterize these findings under carefully controlled conditions, in different types of muscle and to correlate them with changes in muscle structure, composition and biochemical status, we developed an animal model in rats. In this model, nutrient restriction, both after an acute fast and after chronic hypocaloric feeding, resulted in: (a) loss of force during high frequency stimulation but preservation of contraction-relaxation characteristics during low frequency stimulation; (b) slower muscle relaxation rate at high frequency stimulation; (c) increased muscle fatiguability at high frequency stimulation. Measurements of muscle enzymes showed that acute fasting resulted in a reduced content of glycolytic enzymes, but preservation of oxidative enzymes, while chronic hypocaloric dieting resulted in a reduction in both classes of enzyme. There was no significant change in ATP, AMP or energy charge, or in intracellular sodium, potassium and magnesium levels. Creatine phosphate was normal in acutely fasted animals but low in those fed hypocalorically. By contrast, increased intracellular calcium and ADP levels were seen in both fasted and hypocalorically fed animals. These findings suggest that subtle disturbances of intracellular energy states with altered calcium flux may be of importance in the genesis of muscle dysfunction caused by malnutrition.

Animals↗
PubMed1984

Aminergic innervation of cerebral veins. Histochemical comparison with extracranial veins.

The density and distribution pattern of aminergic nerve fibers in intracranial and extracranial veins were compared by means of catecholamine histofluorescence studies. Extracranial veins (internal jugular, inferior caval, portal, renal, internal iliac, and femoral veins) showed quite a uniform distribution pattern. Large veins (jugular, caval, renal, and iliac veins) revealed a spiral pattern, and small veins presented as a meshwork (femoral vein) or in a longitudinal pattern (a branch of the femoral vein). In contrast, intracranial veins displayed more complex patterns: the dural sinus showed a longitudinal pattern and the internal cerebral vein and the superficial vein of Labbé revealed a meshwork of nerve fibers. The aminergic fibers were denser in cerebral veins (dural sinus and internal cerebral vein) than in extracranial veins. The complex distribution and the density of aminergic fibers in cerebral veins suggest that the aminergic innervation of the circulatory system may be more important in the brain than in the extracranial organs.

Amines↗
PubMed1984

[Morphological study on innervation of the cerebrospinal blood vessels. II. Spinal blood vessels].

The distribution patterns of aminergic and cholinergic nerve fibers in the feline spinal blood vessels were studied by means of amine histofluorescence and acetylcholinesterase (AChE) staining. The anterior spinal artery had a dense network of aminergic and AChE-positive (probably cholinergic) nerve fibers. The posterior spinal vein, in contrast, had only aminergic nerve fibers. Intraparenchymal small blood vessels in the spinal cord also had strongly fluorescent (probably peripheral) aminergic nerve fibers. This was quite a characteristic feature in the spinal cord. The distribution pattern and the density of these two sorts of nerve fibers widely varied with the individual segment of the spinal cord. The thoracic spinal cord had the lowest number of these nerve fibers throughout the spinal cord. This fact may give a clue to explain why the thoracic spinal cord is most susceptible to ischemic change.

Acetylcholinesterase↗
PubMed1984

[Peptidergic innervation of the cerebral blood vessels--an immunohistochemical study].

By an immunohistochemical technique, vasoactive polypeptide (VIP)-and substance P-containing nerve fibers are observed in the cerebral blood vessels. VIP-containing nerve fibers distribute in a spiral pattern, similar to the muscle cell distribution pattern. Under an electron microscopic observation, VIP-immunoreactive terminals lie just near to a muscle cell in the inner layer of the adventitia. In contrast, substance P-containing nerve fibers show a meshwork pattern in the outer layer of the adventitia. In combination of acetylcholinesterase (AChE) staining and VIP immunohistochemistry, AChE-positive and VIP-immunoreactive nerve fibers reveal almost same distribution in the same specimen. The present data suggest that VIP-containing nerve fibers may play a role of smooth muscle control of the blood vessels, while substance P-containing nerve fibers may not take part in muscle control.

Animals↗
PubMed1984

[Total parenteral nutrition in inflammatory bowel disease. An evaluation of its clinical response].

We studied the effects of total parenteral nutrition (TPN) on the course of inflammatory bowel disease (IBD) which evaluation was still conflicting. Since 1972, in our department 32 courses of TPN were done for 27 patients with IBD. Definite improvement on nutritional status and clinical symptoms such as abdominal pain, diarrhea, vomiting was observed in most courses of TPN, especially for the patients with intestinal tuberculosis, non-specific multiple intestinal ulcers, and Crohn's disease. Clinical remission was obtained in 26 out of 32 courses of TPN (81.3%) on the short-term follow-up. But on the long-term follow-up ranging from 6 months to 11 years, 11 out of 20 patients (55%) were symptom-free without any medical treatment. Clinical relapse occurred in 6 patients and another TPN was required. These results suggest that TPN is useful as an adjunctive therapy for IBD patients requiring bowel rest and nutritional repletion. Two patients requiring prolonged TPN are returning to work with home parenteral nutrition (HPN) for 2.5 and 5 years respectively. HPN is safe and effective for improving life of quality in the patients receiving prolonged TPN.

Adolescent↗
PubMed1984

[Morphological study on innervation of the cerebrospinal blood vessels. I. Cerebral blood vessels].

The distribution of nerve fibers in the cerebral blood vessels was studied by a catecholamine histofluorescence method, acetylcholinesterase (AChE) staining and immunohistochemistry. The ultrastructure of the terminal boutons in the vessel wall was also studied. In the adventitia of the cerebral artery, green fluorescence aminergic fibers and brownish AChE-positive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. The highest density of aminergic fibers were found in the dural sinus and the second highest in the internal cerebral vein. Serotonin immunoreactive nerve fibers were found along small intraparenchymal blood vessels such as perforating arteries in the brain stem, and arterioles and venules in the cerebral cortex. Under ultrastructural observation, a serotonin immunoreactive terminal was demonstrated in conjunction with the basement membrane of the capillary.

Acetylcholinesterase↗
PubMed1983

Innervation of the cerebral veins as compared with the cerebral arteries: a histochemical and electron microscopic study.

The distribution of nerve fibers in the cerebral veins was studied by catecholamine fluorescence simultaneously with acetylcholinesterase (AChE) histochemistry. A comparison of nerve fibers in the cerebral arteries was made. The ultrastructure of terminal boutons in the veins fixed with potassium permanganate was also studied. In the adventitia of the cerebral artery, green fluorescent aminergic fibers and brownish AChE-reactive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. Catecholamine fluorescent varicose fibers were detected in the dural sinus, the internal cerebral vein, and the superficial vein of Labbé. The highest density of aminergic fibers was found in the dural sinus and the second highest in the internal cerebral vein. Most of the terminal boutons in the adventitia of the cerebral veins were found adjacent to a muscle-like cell and showed only cored vesicles under electron microscopy. Results of our study suggest that the cerebral venous system has a neurogenic innervation, mainly from aminergic fibers, which is different from the neurogenic supply to the cerebral arterial system.

Animals↗
PubMed1983

Aminergic and cholinergic innervations of the spinal cord blood vessels of cats. A histochemical study.

The distribution patterns of aminergic and cholinergic nerve fibers in the feline spinal cord blood vessels were studied by means of amine histofluorescence and acetylcholinesterase (AChE) staining. These patterns were compared with those of the cerebral blood vessels. The anterior spinal artery had a dense network of aminergic and AChE-positive (probably cholinergic) nerve fibers. The posterior spinal vein, in contrast, exhibited only aminergic nerve fibers. Small intraparenchymal blood vessels in the spinal cord also had strongly fluorescent (probably peripheral) aminergic nerve fibers, as well as pial spinal blood vessels. This was a characteristic feature in the spinal cord. The distribution pattern and the density of these two sorts of nerve fibers in the anterior spinal artery varied widely with the individual segment of the spinal cord. The thoracic spinal cord had the lowest number of these nerve fibers of any part of the spinal cord. This fact may explain why the thoracic spinal cord is most susceptible to ischemic change.

Acetylcholinesterase↗
PubMed1981

Comparative anatomy of the distribution of catecholamines within the inferior olivary complex from teleosts to primates.

The distribution of catecholamine (CA) in the inferior olivary complex (IO) of various vertebrate (from fish to monkey) was investigated by means of the histofluorescence technique. In addition, using rats, a further attempt was made to elucidate the origins of CA in the IO. The IO of the lower vertebrates (from fish to birds) was in general poorly innervated by the CA neuron system. IO in the lower mammals, such as insectivora and bats, contained only a few CA nerve terminals, while that in the higher mammals such as rat, guinea pig, rabbit, cat, and monkey revealed quite a number. In these animals, species-species patterns of CA nerve terminals were found. In the rat, the highest concentration was observed in the dorsal lamella of the principal nucleus and in guinea pig ventral lamella. In the rabbit and cat, maximum CA nerve terminals were detected in the dorsal accessory nucleus, while in the monkey, they were detected in the medial accessory nucleus. The retrograde tracer technique of horseradish peroxidase (HRP) suggested that the main source of the abundant CA terminals in IO of the rat might be A1, A2, and A3 noradrenaline neurons, though not locus coeruleus and not dopaminergic ones.

Animals↗