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Biomedical subjects

K Itoi

Publications and source records attributed to K Itoi.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Amebic empyema, a case report].

A 49-year-old man was admitted to our hospital for dyspnea. Chest X-ray examination showed a massive right pleural effusion. Using intrathoracic tube drainage, a large quantity of chocolate-like pleural effusion was removed. Laboratory data demonstrated severe anemia and hypoproteinemia, and TPHA was positive. Antiameba antibody in blood was high, and a liver abscess was demonstrated on abdominal CT scan. Amebic liver abscess and amebic empyema were thus diagnosed. With pleural tube drainage and percutaneous liver abscess drainage, metronidazole (1.5 g/day) was administered. After administering this drug, the high temperature normalized and the patient's general condition improved significantly. Recently, amebic infections have been reported in increased numbers, especially in male homosexuals and immunocompromised patients. Henceforth amebic infection should be considered when pleural effusion and empyema are suspected.

Empyema, Pleural↗
PubMed1993

Effects of tachykinins on phosphoinositide metabolism in the hypothalamus: is the NK1 receptor involved?

Substance P (SP) has been shown to stimulate the hydrolysis of inositol phospholipids in peripheral tissues and in the brain. In mammalian peripheral tissues, three tachykinin receptor subclasses, neurokinin 1 (NK1), neurokinin 2 (NK2) and neurokinin 3 (NK3), have been identified. The purpose of our study was to pharmacologically characterize the SP receptors in the hypothalamus using phosphoinositide breakdown as a functional response. SP, previously described as a NK1 agonist, and Neurokinin A (NKA), previously described as a NK2 agonist, stimulated phosphoinositide breakdown in the hypothalamus in a dose-dependent fashion, with SP being more potent than NKA. The NK2-selective antagonist L-659,877, at a dose of 10(-6) M, abolished the effect of SP (10(-8) M) without affecting basal phosphoinositide breakdown. However, this NK2-selective antagonist did not inhibit the NKA-induced stimulation in phosphoinositide metabolism. The NK1-selective antagonist L-668,169 stimulated phosphoinositide metabolism at a concentration of 10(-6) M, but not at 10(-8) M. This NK1-receptor antagonist did not significantly inhibit the effect of SP on phosphoinositide metabolism. Spantide II, another NK1-selective antagonist, also stimulated phosphoinositide metabolism at a dose of 10(-6) M. Like L-668,169, spantide II failed to inhibit the SP-induced stimulation of phosphoinositide metabolism, and even potentiated the response to SP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Pituitary adenylate cyclase activating polypeptide (PACAP)-like immunoreactivity in ganglioneuroblastoma and neuroblastoma.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a 38 amino acid peptide originally isolated from ovine hypothalamus. It has a potent stimulatory action on adenylate cyclase in the rat pituitary. The presence of PACAP was studied in the tumor tissues of ganglioneuroblastoma and neuroblastoma by radioimmunoassay and immunocytochemistry. Immunocytochemical studies showed positive immunostaining in 4 out of 7 ganglioneuroblastomas and 4 out of 6 neuroblastomas. Immunoreactive PACAP concentrations in tissues of 3 ganglioneuroblastomas ranged from 14.5 to 27.8 pmol/g wet weight (20.0 +/- 5.7 pmol/g wet weight, mean +/- S.D.) and the concentration in one neuroblastoma tissue was 111.0 pmol/g wet weight. Reverse phase high performance liquid chromatography of the tumor tissue extract of ganglioneuroblastoma showed a peak eluting in the position of PACAP1-38 and smaller broad peaks eluting later. These results indicated that high concentrations of immunoreactive PACAP were present in the tumor tissues of ganglioneuroblastoma and neuroblastoma, and suggest the possibility that this peptide plays a pathophysiological role in some ganglioneuroblastomas and neuroblastomas.

Child↗
PubMed1993

Substance P and neurokinin A induced desensitization to cardiovascular and behavioral effects: evidence for the involvement of different tachykinin receptors.

Desensitization and cross-desensitization to the cardiovascular and behavioral effects elicited by intracerebroventricular (i.c.v.) substance P (SP) and neurokinin A (NKA) injections were examined in conscious, freely moving rats. The cardiovascular responses to equimolar doses of both peptides were identical, however, the pattern of the behavioral responses differed. Relative to SP, NKA was weaker in eliciting hindquarter grooming but more effective in eliciting wet dog shakes. SP pretreatment (50 pmol) desensitized the cardiovascular and behavioral responses to both, subsequent injections of SP (50 pmol) as well as of NKA (50 or 500 pmol) injected 30 or 60 min after SP, indicating cross-desensitization. NKA pretreatment (50 pmol) partly reduced the cardiovascular but not the behavioral responses to subsequent equimolar doses of NKA. The cardiovascular responses to SP (50 pmol) were reduced only 30 min but not 60 min after pretreatment with a 10 times higher dose of NKA (500 pmol). Of all behavioral manifestations to i.c.v. SP, only hindquarter grooming was attenuated by pretreatment with either dose of NKA. The equal potency of SP and NKA in eliciting the cardiovascular effects but different pattern of behavioral responses to these peptides suggest an involvement of different types of tachykinin receptors in mediating the central effects of the two peptides. The fact that NKA induced cross-desensitization selectively to one type of behavioral manifestations elicited by SP, indicates the existence of two subtypes of SP (NK1) receptors in the rat brain.

Animals↗
PubMed1993

Endothelin in ectopic ACTH-secreting bronchial carcinoid tumors.

The presence of immunoreactive endothelin (ir-ET) in the tumor tissues of two cases of ectopic ACTH-secreting bronchial carcinoid tumors was studied by radioimmunoassay. The cross-reaction with big ET-1, ET-2, and ET-3 was 5%, 6%, and 6%, respectively. Tumor tissue ir-ET concentrations in two ectopic ACTH-secreting bronchial carcinoid tumors were 920 and 3,370 fmol/g wet weight, which were much higher than those in pheochromocytomas (146 +/- 70 fmol/g wet weight; n = 12, mean +/- SD), adrenocortical tumors (115 +/- 105 fmol/g wet weight, n = 14), and normal parts of adrenal glands (82 +/- 31 fmol/g wet weight, n = 12). High-performance liquid chromatography of the tumor tissue extract showed that the ir-ET was mainly eluted in the position of ET-1. Plasma levels of ir-ET in these two cases were not elevated (1.2 and 1.7 pmol/L). The findings of the present study suggest that ET-1 has local pathophysiologic roles in the tumor tissues of ectopic ACTH-secreting bronchial carcinoid tumors.

Adrenal Cortex Neoplasms↗
PubMed1993

Colocalization of corticotropin-releasing factor and vasopressin in the paraventricular nucleus of the human hypothalamus.

The anatomical relationship between corticotropin-releasing factor (CRF)-containing cells and arginine vasopressin (AVP)-containing cells in the human hypothalamus was investigated by immunocytochemistry. In the paraventricular nucleus of the hypothalamus (PVH), CRF-like immunoreactivity (CRF-LI) was present exclusively in parvocellular cells, while AVP-like immunoreactivity (AVP-LI) was present in both parvocellular and magnocellular cells. No CRF-immunoreactive neurons were observed in the supraoptic nucleus. All CRF-immunoreactive parvocellular cells in the PVH were also AVP immunoreactive. We confirmed the presence of AVP in the CRF-immunoreactive cells by using two kinds of anti-AVP antisera, one of which recognized the side chain of AVP while the other recognized the ring structure of AVP. Colocalization of CRF-LI and AVP-LI was observed not only in the same perikarya but also in the same nerve fibers of parvocellular cells. The present results raise the possibility that AVP and CRF may be secreted together into the human portal circulation.

Adolescent↗
PubMed1993

An ACTH-secreting bronchial carcinoid: presence of corticotropin-releasing hormone, neuropeptide Y and endothelin-1 in the tumor tissue.

The presence of three regulatory peptides, corticotropin-releasing hormone, neuropeptide Y and endothelin-1, was studied by radioimmunoassay in the tumor tissue of an ACTH-secreting bronchial carcinoid. A 36-year-old female was admitted to hospital because of moon face, central obesity and hypertension. High levels of plasma ACTH and cortisol and urinary 17-OHCS and 17-KS were found. One mg dexamethasone did not suppress plasma ACTH and cortisol levels, but 8 mg did so slightly. Corticotropin-releasing hormone (100 micrograms, iv) stimulated plasma ACTH levels (0 min; 34.8 pmol/l; 30 min; 41.1 pmol/l). The computerized tomography showed the presence of a tumor in the right lung. This lung tumor was removed surgically and has been shown by microscopical examination to be a bronchial carcinoid with ACTH-positive cells. The tumor tissue concentrations of corticotropin-releasing hormone, neuropeptide Y and endothelin-1 were 3.34 pmol/g wet weight, 8.07 pmol/g wet weight and 0.92 pmol/g wet weight, respectively, although plasma concentrations of these three peptides were not elevated. Reverse phase high performance liquid chromatography showed that immunoreactive peptides in the tumor tissue were mainly eluted in the position of the standard peptides. These findings indicate that this case of ACTH-secreting bronchial carcinoid had high levels of corticotropin-releasing hormone, neuropeptide Y and endothelin-1 in its tumor tissue and suggested that these peptides may act locally, in a paracrine or autocrine manner, in the tumor.

ACTH Syndrome, Ectopic↗
PubMed1993

Isolation of trehalamine, the aglycon of trehazolin, from microbial broths and characterization of trehazolin related compounds.

Trehalamine, (3aR,4R,5S,6S,6aS)-2-amino-4-(hydroxymethyl)-3a,5,6,6a- tetrahydro-4H-cyclo-pent[d]oxazole-4,5,6-triol (1) and D-glucose were obtained by acid hydrolysis of trehazolin (3), a trehalase inhibitor produced by actinomycetes. More vigorous hydrolytic treatment of trehazolin afforded an aminocyclitol, (1R,2S,3R,4S,5R)-5-amino-1- (hydroxymethyl)cyclopentane-1,2,3,4-tetraol (2). Trehalamine, the aglycon of trehazolin, was also found in the culture broths of two trehazolin producing strains, Micromonospora sp. SANK 62390 and Amycolatopsis sp. SANK 60791. These trehazolin related compounds trehalamine (1) and 2 were poor inhibitors of trehalase (1; IC50 1.8 x 10(-4) M, 2; > 5.0 x 10(-4) M). On the other hand they inhibited more potently rat intestinal sucrase (1; IC50 6.8 x 10(-5) M) and sweet almond beta-glucosidase (2; IC50 5.6 x 10(-6) M) than trehazolin.

Actinobacteria↗
PubMed1993

[A case of pulmonary lymphangiomyomatosis treated with bilateral oophorectomy and methyl-progesterone-acetate].

A case of pulmonary lymphangiomyomatosis is reported. A 37-year-old woman was admitted with hemosputum and dyspnea on exertion. Chest roentgenogram revealed diffuse reticulonodular shadows and arterial hypoxemia was present. Pulmonary function tests showed severe restrictive & obstructive impairment, and pulmonary perfusion scintigraphy with 99mTc-MAA showed non-segmental disproportion. The histological diagnosis of pulmonary lymphangiomyomatosis was made by transbronchial lung biopsy. She underwent bilateral oophorectomy under general anesthesia. However, the arterial hypoxemia advanced gradually, and medroxyprogesterone-acetate (MPA) was commenced (200 mg/day). Her condition remained stable after the description of MPA.

Adult↗
PubMed1993

[TV-assisted thoracoscopic surgery with a lung forceps combined with thoracoscope under local anesthesia for spontaneous pneumothorax with a persistent air leak--a single access port approach].

TV-assisted thoracoscopic surgery was performed under local anesthesia by through a single access port to control a continuing air leak in spontaneous pneumotorax. A 75-year-old man was admitted with severe dyspnea and right-sided chest pain. The chest X-ray film showed right lung collapse. A right spontaneous pneumothorax was diagnosed and was treated by chest tube drainage. However, the lung did not re-expand because of a continuing air leak and subcutaneous emphysema developed. TV-assisted thoracoscopic surgery was performed under local anesthesia to treat the persistent air leak on day 12. By endoscopy, the ruptured bulla was double-ligated with an Endoloop through a single access port using lung forceps combined with endoscope. The air leak subsequently ceased and the lung re-expanded. This method is minimally invasive and is very suitable for controlling a continuing air-leak causing spontaneous pneumothorax in a patient.

Aged↗
PubMed1993

[Local resection of pulmonary lesions by Nd-YAG laser without suturing].

Local excision of 67 pulmonary lesions in 5 patients was performed with the Nd-YAG laser. There were 2 women and 3 men with an average age of 68 years. The patients consisted of three cases of metastatic lung cancer (65 lesions), one hamartoma (One lesion) and one organized pneumonitis (one lesion). The lesion was first enucleated by a contact method using an Nd-YAG laser scalpel, then the crater of the resected lesion in the normal lung tissue was coagulated with a defocused laser beam. The craters of 52 of the 67 resected lesions which were shallow seated in the lung were left open, but the other 15 resected lesions were closed with sutures. Total blood loss was less than 100 ml. There was no bleeding or air leakage (30 cm water pressure) during the post operative days in 4 of the 5 patients, but one patients (one lesion) had to be treated by bronchoscopic endobronchial embolization against a persistent air leak. This lesion was 2.5 cm in diameter and 4 cm deep in the lung on CT. The other lesions were also measured by CT. The tumor size was 1.4 +/- 0.7 cm and the depth was 2.4 +/- 1.0 cm. The Nd-YAG laser is very suitable for local resection of peripheral lung lesions without suturing.

Aged↗
PubMed1992

Identification of the central tachykinin receptor subclass involved in substance P-induced cardiovascular and behavioral responses in conscious rats.

To identify the tachykinin receptor subclass involved in the central cardiovascular and behavioral actions of substance P (SP), we compared the central actions of SP with those of neurokinin A (NKA) and senktide in conscious chronically instrumented rats. Intracerebroventricular (i.c.v.) injection of SP (an NK1 agonist) and NKA (an NK2 agonist) increased mean arterial pressure (MAP) and heart rate (HR) dose dependently and these cardiovascular responses were associated with the behavioral responses, comprising excessive grooming and exploring. Both peptides were equipotent to produce the cardiovascular and the behavioral responses. Senktide (a highly selective NK-3 agonist), injected i.c.v. increased the HR markedly. The behavioral response, 'wet dog shakes', was observed most frequently after senktide and was dissociated from the HR response. Pretreatment with a peripheral NK-1-selective antagonist, L-668,169, attenuated the NKA-induced cardiovascular and behavioral responses but not the SP-induced responses. However, pretreatment with a peripheral NK-2-selective antagonists, L-659,877, attenuated the SP-induced responses but not the NKA-induced responses. These results suggest that the central cardiovascular and behavioral actions of SP and NKA are mediated by different subclasses of receptors and that the receptor subclasses which are specific for the central nervous system differ from those which mediate the peripheral actions of the two tachykinins.

Animals↗
PubMed1992

Neuropeptide Y as a plasma marker for phaeochromocytoma, ganglioneuroblastoma and neuroblastoma.

1. We investigated the usefulness of neuropeptide Y as a plasma marker for phaeochromocytoma, ganglioneuroblastoma and neuroblastoma using a simple and highly sensitive r.i.a. for human neuropeptide Y. 2. Plasma immunoreactive neuropeptide Y concentrations were measured without extraction in plasma samples (100 microliters) from patients with various diseases. 3. The plasma immunoreactive neuropeptide Y concentration in patients with phaeochromocytoma (172.3 +/- 132.4 pmol/l, mean +/- SD, n = 23) was significantly higher than that in healthy adult subjects (40.1 +/- 10.1 pmol/l, n = 40, P < 0.0001). The plasma immunoreactive neuropeptide Y concentrations in patients with ganglioneuroblastoma (590.7 +/- 563.6 pmol/l, n = 6) and patients with neuroblastoma (566.9 +/- 524.4 pmol/l, n = 15) were significantly higher than those in control children (1-9 years old, 82.2 +/- 39.9 pmol/l, n = 72, P < 0.0001). 4. The plasma immunoreactive neuropeptide Y concentration in patients with essential hypertension (34.0 +/- 3.7 pmol/l, n = 18) was within the normal range, but in patients with chronic renal failure undergoing maintenance haemodialysis (192.1 +/- 68.0 pmol/l, n = 25) and in non-dialysed patients with chronic renal failure (85.1 +/- 23.1 pmol/l, n = 7) it was significantly higher than that in healthy adult subjects (P < 0.0001). 5. Eighty-seven per cent of the patients with phaeochromocytoma, 67% of the patients with ganglioneuroblastoma and 80% of the patients with neuroblastoma showed plasma immunoreactive neuropeptide Y concentrations higher than the upper limits in the control subjects [62 pmol/l (adult) and 160 pmol/l (children)].(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Use of selective antagonists to dissociate the central cardiovascular and behavioural effects of tachykinins on NK1 and NK2 receptors in the rat.

1. The effects of intracerebroventricular (i.c.v.) pretreatment with selective NK1 ((+/-)-CP 96,345), NK2a (MEN 10,207; MEN 10,376) and NK2b (R 396) tachykinin receptor antagonists on the cardiovascular and behavioural responses to i.c.v. substance P (SP) and neurokinin A (NKA) were studied in conscious rats. 2. SP and NKA (25 pmol) induced mean arterial blood pressure and heart rate increases of the same magnitude and duration. The cardiovascular responses to both peptides were accompanied by excessive face washing, sniffing, grooming and wet dog shakes. 3. The cardiovascular responses to SP but not to NKA were attenuated by pretreatment with a NK1 receptor antagonist, (+/-)-CP 96,345. Of the behavioural responses, only face washing was significantly inhibited. 4. The cardiovascular and behavioural effects of NKA but not of SP were significantly attenuated by pretreatment with the selective NK2b receptor antagonist, R 396. 5. The selective NK2a receptor antagonists, MEN 10,207 and MEN 10,376, did not affect the cardiovascular and behavioural responses to either SP or NKA. 6. These results suggest, firstly, that the cardiovascular and behavioural effects of i.c.v. SP are mediated by NK1 receptors; secondly, that NKA injected i.c.v. does not interact with NK1 receptors but with another type of tachykinin receptor which may belong to the NK2b subclass. These findings provide pharmacological evidence for the existence of functionally active NK2 receptors in the rat brain.

Amino Acid Sequence↗
PubMed1992

[A case report of radiation osteomyelitis 9 years after irradiation for thymoma].

Radiation osteomyelitis of the sternum is rare and usually difficult to cure. A 75-year-old man, who had undergone an exploratory sternotomy for a mediastinal tumor, not resected after all, 9 years earlier and received radiation therapy successively for the histological diagnosis of malignant thymoma, was admitted to our hospital with the chief complaint of fever and pus discharge of the anterior chest wall. He also suffered from diabetes mellitus. The skin around the fistula was dark-red and atrophic due to irradiation dermatitis and the manubrium was fissured in the midline. Open drainage and two-stage operation of direct closure was tried in vain. This case was treated successfully by resection of necrosed portion of sternum and pectoral muscle flap closure.

Aged↗
PubMed1992

[A case of lung cancer in a patient with von Recklinghausen's disease].

A 57-year-old man was admitted to our hospital for further investigation of an abnormal shadow in his chest X-ray. He had cafe-au-lait spots and multiple subcutaneous neurofibromas and was diagnosed as having von Recklinghausen's disease. Bronchofiberscopy was performed, but an adequate specimen was not obtained. Therefore, percutaneous needle biopsy was performed, and the specimen showed poorly-differentiated adenocarcinoma. The left subclavian artery was deviated on aortography, therefore, neoadjuvant chemotherapy with CDDP & VDS was performed. He subsequently underwent left upper lobectomy. Pathologically, the tumor cell showed necrosis and scarring. Including this case, there have been 11 reports of von Recklinghausen's disease associated with lung cancer in the Japanese literature. Adenocarcinoma was observed in 72.9% of cases, and poorly-differentiated tumor was observed in 7 out of 8 patients with distinct tumor differentiation.

Adenocarcinoma↗