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Biomedical subjects

M Nakano

Publications and source records attributed to M Nakano.

At least 163 records · Page 9Linked to original sources
PubMed2000

CD4(+) Valpha14 natural killer T cells are essential for acceptance of rat islet xenografts in mice.

Pancreatic islet transplantation represents a potential treatment for insulin-dependent diabetes mellitus. However, the precise cellular and molecular mechanisms of the immune reactions against allogeneic and xenogeneic transplanted islets remain unclear. Here, we demonstrate that CD4(+) Valpha14 natural killer T (NKT) cells, a recently identified lymphoid cell lineage, are required for the acceptance of intrahepatic rat islet xenografts. An anti-CD4 mAb, administrated after transplantation, allowed islet xenografts to be accepted by C57BL/6 mice, with no need for immunosuppressive drugs. The dose of anti-CD4 mAb was critical, and the beneficial effect appeared to be associated with the reappearance of CD4(+) NKT cells at around 14 days after transplantation. Interestingly, rat islet xenografts were rejected, despite the anti-CD4 mAb treatment, in Valpha14 NKT cell-deficient mice, which exhibit the normal complement of conventional lymphoid cells; adoptive transfer of Valpha14 NKT cells into Valpha14 NKT cell-deficient mice restored the acceptance of rat islet xenografts. In addition, rat islet xenografts were accepted by Valpha14 NKT mice having only Valpha14 NKT cells and no other lymphoid cells. These results indicate that Valpha14 NKT cells play a crucial role in the acceptance of rat islet xenografts in mice treated with anti-CD4 antibody, probably by serving as immunosuppressive regulatory cells.

Animals↗
PubMed2000

72-kDa stress protein (hsp72) induced by administration of dimethylarsinic acid to mice accumulates in alveolar flat cells of lung, a target organ for arsenic carcinogenesis.

Our previous studies have demonstrated that the oral administration of dimethylarsinic acid (DMA), a main metabolite of inorganic arsenics in mammals, in mice causes DNA damage in the lung as well as the promotion and progression of lung- and skin-tumorigenesis. Moreover, we indicated that 72-kDa stress protein (Hsp72) was induced in cultured human pulmonary (L-132) cells by exposure to DMA and was accumulated specifically in the cell nuclei. The present in vivo study reveals the induction of Hsp72 by intraperitoneal administration of DMA to A/J mice used previously as an animal model of dimethylarsenic-induced lung tumorigenesis. The Hsp72 was observed in the lung, a target organ for arsenic carcinogenesis in human, and in the kidney as well, but not in the liver and spleen. By immunohistochemical analysis, the Hsp72 in lungs was exhibited to exist in the nuclei of alveolar flat cells, including capillary endothelial cells, which were previously found to increase the clumping of heterochromatin, an early morphological change in the developmental process of pulmonary carcinomas, after administration of DMA to mice. These in vivo observations suggest that the increase and accumulation of Hsp72 by administration of DMA to mice may occur specifically in target organs for arsenic carcinogenesis.

Animals↗
PubMed2000

Inhibitory effect of human immunodeficiency virus protease inhibitors on multidrug resistance transporter P-glycoproteins.

The objective of this study was to determine whether human immunodeficiency virus (HIV) protease inhibitors (saquinavir, ritonavir and nelfinavir) interact with other HIV protease inhibitors and/or HIV reverse transcriptase inhibitors (zidovudine, didanosine, lamivudine, zalcitabine and sanilvudine). We measured transport of nelfinavir, an HIV protease inhibitor which is known as a substrate for the multidrug resistance transporter P-glycoprotein (P-gp), in an epithelial monolayer model and Ki for P-gp of some drugs by a calcein flux assay. Transport in a basal to apical direction was 2-fold greater than apical to basal flux for nelfinavir, Ki for P-gp of a potent P-gp inhibitor cyclosporin A was 1.09 microM and those of ritonavir and nelfinavir were 111 microM and 28.6 microM, whereas all HIV reverse transcriptase inhibitors gave high K1 values. These data show that nelfinavir, which is a substrate for P-gp, inhibits a P-gp function as a drug efflux pump and that HIV reverse transcriptase inhibitors do not inhibit P-gp.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Roles of hydrophobicity, protein binding and the probenecid-sensitive transport system in the cerebrospinal fluid delivery of nucleoside analogues with anti-viral activity.

Ten nucleoside analogues with anti-herpes or anti-HIV activity were investigated for their transport into the cerebrospinal fluid (CSF) following intravenous administration in rats. The novel anti-herpes agent 1-beta-D-arabinofuranosyl-2-thio-5-fluorocytosine (5F-araSC) showed the highest CSF/plasma concentration ratio (>20%), while that of acyclovir (ACV) was very low (<5%). A linear relationship was observed between the partition coefficient (chloroform/water) and CSF/unbound plasma concentration in 6 of 9 agents. The exceptions were DDI, AZT and ACV, which showed much lower concentrations in the CSF than expected from their hydrophobicity and protein binding activities. The effects of probenecid treatment on the CSF and plasma concentrations were measured with continuous intravenous administration of ACV, AZT, araC and 5F-araSC. Probenecid markedly increased the CSF concentrations of ACV and AZT, although the effect was minimal in araC and 5F-araSC. These results may provide useful information for molecular design of nucleoside analogues with better transport to the brain.

Animals↗
PubMed2000

Studies on adsorption characteristics of bile acids and methotrexate to a new type of anion-exchange resin, colestimide.

The adsorption characteristics of various bile acids and methotrexate to a new type of anion-exchange resin, colestimide, were studied in vitro and compared with those to cholestyramine. For bile acids, colestimide was shown to have a higher capacity than cholestyramine. For example, approximately 1.4-fold higher for cholic acid and 2.0-fold for deoxycholic acid in water. In the presence of physiological anions, the degree of adsorption of cholic acid to both resins was greatly reduced, whereas adsorption of deoxycholic acid was only slightly reduced. Furthermore, the bed-volume of colestimide swelled about 6.8-fold in water, hence the anion-exchange groups of this resin are expected to be able to function effectively in adsorption of bile acids in the gut. In addition, colestimide was found to have high adsorption capacity for methotrexate, not only in water but also in media containing various physiological anions, and thus it is suggested that colestimide is a potential oral antidote to reduce possible toxicity by methotrexate through interruption of enterohepatic circulation.

Anion Exchange Resins↗
PubMed2000

[GC-MS determination of l-ephedrine and d-pseudoephedrine in human plasma].

To determine l-ephedrine (E) and d-pseudoephedrine (PE) concentrations in human plasma simultaneously, we used a selected-ion monitoring method with gas chromatography-mass spectrometry (GC-MS) using deuterium-labeled E and PE as internal standards. The E and PE in human plasma were extracted with hexane-ethylacetate (9/1) under alkaline conditions and were easily converted into their heptafluorobutyryl derivatives by treating with heptafluorobutyrylimidazole. The calibration curves of E and PE showed a good linearity in the range from 0.82 to 81.9 ng/ml for E, and from 0.41 to 41.0 ng/ml for PE, respectively. The limit of detection was 0.82 ng/ml for E and 0.41 ng/ml for PE in human plasma, respectively.

Ephedrine↗
PubMed2000

Plasma concentrations of an angiotensin-converting enzyme inhibitor, benazepril, and its active metabolite, benazeprilat, after repeated administrations of benazepril in dogs with experimental kidney impairment.

In order to examine the safety of an angiotensin-converting enzyme (ACE) inhibitor in dogs with impaired renal excretion route, benazepril was administered orally, and plasma concentrations of benazeprilat, the active metabolite of benazepril, were determined in dogs with renal mass reduction (1/4th kidney) created by right-side nephrectomy and ligation of branches of the left renal arteries. Five dogs were administered benazepril orally at a given dose (0.5 mg/kg body weight) and 4 other dogs received 20 times that dose (10 mg/kg body weight) once daily for 15 consecutive days before (intact kidney period) and after (1/4th kidney period) creation of kidney impairment. Six control dogs received surgical treatment, but no drug. After creating a 1/4th kidney, plasma urea nitrogen and creatinine concentrations increased to approximately 30 mg/dl and 2.0 mg/dl, respectively, and renal plasma flow and glomerular filtration rate decreased to 37% and 30% of pre-treatment values, respectively. However, these parameters did not change significantly during the 1/4th kidney period both in the 0.5 mg/kg and 10 mg/kg groups. In the 0.5 mg/kg group, plasma benazeprilat concentrations increased to approximately 20 ng/ml to 340 ng/ml 2 hr after each administration, and there were no significant differences between the plasma benazeprilat concentrations during the intact and 1/4th kidney periods. In the 10 mg/kg group, plasma benazeprilat concentrations varied in the individual dog, but did not increase with the days of administration, and were not significantly different on each administration day between the intact and 1/4th kidney periods in either dose group. The AUCs(0-24) of plasma benazeprilat concentrations determined on the 15th administration day were not different between the intact and 1/4th kidney periods in dogs of either dose group. Plasma ACE activities decreased after drug administration in dogs of both groups. Benazepril seemed to have a high safety, and the adjustment of dosage regimen might not be needed in dogs with mild to moderate renal function impairment because the drug was excreted both from the kidneys and liver.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2000

Growth and metabolic disturbances in a patient with total parenteral nutrition: a case of hypercalciuric hypercalcemia.

Hypercalciuria is a common side effect during total parenteral nutrition (TPN). We report a patient with long-term TPN, who demonstrated hypercalciuria, hypercalcemia and growth retardation. The patient is a six-year-old Japanese girl with Hirschsprung disease (jejunal agangliosis). Jejunostomy was performed at one-month old and since then her nutrition has depended mostly on TPN. When she was 3 years old, continuous TPN was switched to cyclic TPN (on TPN for 11 hrs and off TPN for 13 hrs). The urinary calcium level has been elevated (Ca/Cre ratio, 1.0) since 3 months of age, whereas serum calcium levels stayed within normal range for a while. The serum calcium levels started to elevate to 12 to approximately 13 mg/dl when she was 3 years and 8 months old. She showed growth retardation (height SD score was -4.2SD when she was 5 years and 8 months old) and deteriorated renal tubular function with renal glycosuria, elevated beta 2-microglobulin (beta2-MG) and N-acetyl-beta-D-glucosaminidase. She was referred to our division for the investigation and treatment of growth disturbance and Ca metabolism. Her bone age was delayed (BA/CA 0.62) and serum IGF-I level was decreased but her GH response to provocation test was normal. Bilateral nephrocalcinosis was revealed by renal echogram and CT scan. By reducing calcium content in TPN solution, the serum and urinary calcium levels could be maintained within normal range and her renal function and growth velocity was improved.

Calcium↗
PubMed2000

Hyponatremia with increased plasma antidiuretic hormone in a case of hypothyroidism.

We report a 70-year-old woman with hypothyroidism and severe hyponatremia. Her plasma antidiuretic hormone (ADH) level was inappropriately high for her low plasma osmolality. Her low serum sodium level was gradually corrected by water restriction and sodium supplementation prior to the initiation of thyroid hormone replacement. After a diagnosis of Hashimoto's thyroiditis had been made, the patient was treated with levothyroxine. Following this treatment, the patient's serum sodium level increased drastically. It is suggested that the elevated plasma ADH level played an important role in the development of hyponatremia in this case.

Adrenal Glands↗
PubMed2000

[Suicidal attempts in three postoperative patients with renal cancer after alpha interferon withdrawal].

We report 3 cases of suicide attempts in postoperative patients with renal cancer after alpha interferon withdrawal. In the first patient, depression occurred during interferon therapy, and remained after interferon withdrawal. A suicide attempt occurred 7 months after interferon withdrawal. In the second and third patients, depression did not occur during interferon therapy, but suicide attempts occurred 40 days and 7 months after interferon withdrawal, respectively. Depression does not always disappear after interferon is discontinued. Psychiatric supervision should be continued even more frequently after interferon withdrawal. The increased risk of psychiatric side effects due to interferon, as well as their severity, suggest that interferon should be administered with caution.

Aged↗
PubMed2000

[A phase II study of irinotecan combined with cisplatin in non-small cell lung cancer. CPT-11 Lung Cancer Study Group].

Based upon the results of phase I study of irinotecan (CPT-11) combined with cisplatin (CDDP) on non-small cell lung cancer (NSCLC), a combination phase II study on NSCLC was carried out from Feb., 1992 to Sep., 1992. CPT-11 (60 mg/m2) and CDDP (80 mg/m2) were administered by i.v. drip infusion, with administration schedules of Days 1, 8, 15 and only Day 1, respectively. This therapy course was repeated every 4 weeks. Subjects were NSCLC patients of stage III B or IV disease. Those without prior chemotherapy (Group A) and those with prior therapy (Group B) were enrolled separately. Seventy patients were entered into Group A and 32 patients into Group B. One of the patients of Group A was ineligible. The characteristics of the eligible cases of Group A were: male/female, 51/18; median age, 61 years old; PS 0/1/2, 18/39/12; stage IIIB/IV, 26/43; and adeno/squamous/large, 51/15/3. Those of group B were: male/female, 20/12; median age, 62 years old; PS 0/1/2, 5/18/9; stage I/IIIB/IV, 1/7/24, adeno/squamous/large/ad-sq, 28/2/1/1. Thirty-three patients (47.8%) responded in Group A and B patients (25.0%) responded in Group B. Major adverse reactions (grade 3 or higher) of Group A/Group B were neutropenia (80.3%/73.3%), anemia (35.3%/34.4%), diarrhea (18.8%/28.1%) and nausea/vomiting (34.8%/34.4%). Median survival times for Group A and Group B were 308 and 295 days, respectively. CPT-11 in combination with CDDP is effective against NSCLC, suggesting that further studies are needed to determine the usefulness of this therapy.

Adult↗
PubMed2000

Cyanamide-induced liver dysfunction after abstinence in alcoholics: a long-term follow-up study on four cases.

BACKGROUND: Cyanamide, an aversive agent widely used in Japan, is known to induce various degrees of hepatic lesion with ground-glass inclusion bodies. When cyanamide-treated alcoholics relapse into drinking, more severe inflammation develops in the liver. However, it is controversial whether progressive hepatic lesions develop in complete abstainers as a result of long-term cyanamide treatment. CASE REPORTS: Case 1: A 53-year-old male alcoholic received cyanamide treatment for 4.5 months and completely abstained without cyanamide treatment for 6 years. A liver biopsy shortly after abstinence showed extensive pericellular fibrosis, but a biopsy after 6 years showed very mild fibrosis. Case 2: A 43-year-old male alcoholic remained completely abstinent with cyanamide treatment for 5 years and complained of general fatigue. His serum transaminases were slightly elevated and hepatic hyperechogenicity was observed on ultrasonography. Only mild pericellular fibrosis was present in the liver biopsy specimen obtained shortly after abstinence, but after 5 years the second liver biopsy showed that thin septum-like fibrosis that formed portal-to-portal and portal-to-central linkage had developed and ground-glass hepatocytes had emerged extensively. Case 3: A 29-year-old female alcoholic complained of general fatigue and a slight fever after 1.5 years of abstinence with cyanamide treatment. Slight elevation of serum transaminases and hepatic hyperechogenicity were observed. The liver biopsy showed extensive ground-glass hepatocytes and thin septum-like fibrosis that formed portal-to-portal linkage. Case 4: A 61-year-old male alcoholic who remained completely abstinent while taking cyanamide for 3 years showed slight elevation of serum transaminases. Liver biopsy showed extensive ground-glass hepatocytes and extension of thin septum-like fibers from portal tract to the lobule. Ultrasonography revealed hepatic hyperechogenicity. CONCLUSION: In some abstainers who take cyanamide for several years, thin septum-like liver fibrosis progresses along with the emergence of ground-glass hepatocytes. Hepatic hyperechogenicity on ultrasonography and slight elevation of serum transaminases might erroneously lead to a diagnosis of hepatic steatosis without liver histology.

Adult↗
PubMed2000

[An autopsy case of malignant lymphoma who showed hearing loss and cavernous sinus syndrome in the first stage and hemophagocytic syndrome].

A 48-year-old man was admitted to our hospital due to multiple cranial neuropathy such as vertigo, hearing loss of the left ear, visual loss of the left eye, left ptosis and total ophthalmoplegia of the left eye. Brain MRI revealed no abnormalities. After 10 days, he suddenly showed hemophagocytic syndrome with high fever, liver dysfunction, jaundice and pancytopenia. In spite of the treatment, he died of multiple organ failure after 26 days. At autopsy, malignant lymphoma cells of T cell origin directly invaded into the liver, spleen, intraperitoneal lymph nodes and other organs. Reports that direct invasion of lymphoma cells could be detected at the cranial nerves in the cavernous sinus are very rare.

Cavernous Sinus↗
PubMed2000

Clinical significance of anticentromere antibodies in patients with systemic lupus erythematosus.

OBJECTIVE: To clarify the clinical significance of anticentromere antibodies (ACA) in patients with systemic lupus erythematosus (SLE). METHODS: Two hundred sixteen patients with SLE who were treated in our department were surveyed cross sectionally for the presence of ACA using indirect immunofluorescence on HEp-2 cell lines. ACA were identified by their discrete speckled pattern. Antibodies to the major centromere protein, CENP-B, were also studied with ELISA. Serial determinations of anti-CENP-B were carried out using stored serum samples, if available. RESULTS: ACA were recognized in 12 (5.6%) patients with SLE. All patients were receiving steroid therapy, with a mean dose of prednisolone of 14.4 mg/day. These patients also tested positive for anti-CENP-B with high titers despite the low serological disease activity in most. Three or more CREST features were observed in 2 patients and 2 others had no such features. Both patients without CREST features had a relatively short disease duration. The age at onset of SLE was significantly higher and Raynaud's phenomenon was more frequent in patients with ACA than in patients without ACA. In 8 of 10 patients tested, retrospective analysis using stored sera revealed no consistent change in anti-CENP-B titers over time. CONCLUSION: The presence of ACA in patients with SLE is apparently more frequent than previously believed. Patients with SLE with ACA may be a distinct subgroup. A longterm followup is warranted to fully determine the clinical significance of ACA in patients with SLE.

Adolescent↗
PubMed2000

[Hyperbaric oxygen as an adjunctive treatment for descending necrotizing mediastinitis: report of a case].

We report a case of 59-year-old man of descending necrotizing mediastinitis (DNM) secondary to peritonsillar abscess. A 59-year-old man with diabetes mellitus was admitted to a local hospital because of cervical swelling related to a peritonsillar abscess. Despite administration of antibiotics, swelling of the neck, dysphagia and dyspnea deteriorated. Therefore he was urgently undergone a tracheotomy and transferred to our hospital by an ambulance. The surgery consisted with neck and anterior mediastinal drainage through neck and cervical collar incision. Culture of drainage fluid showed clostridium difficile. On postoperative day 5, we started hyperbaric oxygen therapy (HBOT). After lavage and HBOT, the patient improved by degrees, and discharged on postoperative day 82. DNM is a rare but serious complication of otopharyngeal and deep neck infection that spreads down to the mediastinum through the cervical-facial planes. Its mortality rate remains high even with aggressive surgical drainage and appropriate antibiotics. Our patient was successfully treated with urgent surgical drainage, antibiotics and HBOT. HBOT might be of great value as an adjunctive management to control this fatal infection.

Anti-Bacterial Agents↗
PubMed2000

[A case of non-small-cell lung cancer successfully treated using combination chemotherapy with CDDP and vinorelbine].

A 67-year-old woman presented to our hospital with a chief complaint of bloody sputum. A plain chest X-ray a CT scan revealed a tumor shadow 3 cm in size in the middle lobe of the right lung, multiple nodular shadows in the bilateral lung fields and enlarged hilar and mediastinal lymph nodes. A tumor biopsy done under bronchoscopy revealed poorly differentiated adenocarcinoma of the lungs (cT2N3M1). She was given two courses of combination therapy consisting of cisplatin (80 mg/m2) and vinorelbine (20 mg/m2). The primary tumor in the middle lobe of the right lung and the lung metastases were markedly reduced in size, and a complete response was obtained. The only adverse events were grade 4 neutropenia and grade 2 nausea and vomiting.

Aged↗