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Biomedical subjects

M Niimi

Publications and source records attributed to M Niimi.

At least 73 records · Page 4Linked to original sources

Familial hyperparathyroidism.

Familial hyperparathyroidism (HPT) is a hereditary disease in which HPT is transmitted in an autosomal dominant fashion. It includes a variety of diseases: multiple endocrine neoplasia (MEN) type 1 and type 2, and familial isolated hyperparathyroidism (FIHPT). We screened for MEN 1 mutations by direct nucleotide sequencing of all protein-coding regions and identified the germline mutations of the MEN 1 gene in two families with familial HPT. Patients with FIHPT have multiple abnormal parathyroid glands and are prone to both recurrent and persistent HPT. They frequently present with profound hypercalcemia, in contrast to patients with MEN-associated HPT or sporadic HPT. We recommend subtotal or total parathyroidectomy plus autotransplantation in patients with MEN-associated HPT and patients with FIHPT. Because parathyroid remains or supernumerary glands are often present in the thymus or perithymic tissue, we advocate routine bilateral dissection of the central zone with bilateral cervical thymectomy.

DNA↗

Experimental parathyroid transplantation: human parathyroid grafts survived and functioned in mice treated with anti-CD4 monoclonal antibody.

Permanent hypoparathyroidism is one of the most difficult of all endocrine disorders to treat medically. To examine the possibility that xenotransplantation can be used to treat hypoparathyroidism, human parathyroid tissues were transplanted into mice. Human parathyroid tissue was taken from specimens excised from patients with hyperparathyroidism. Fresh human parathyroid tissue was implanted under kidney capsule of CBA (H2k) mice. Some mice were treated intraperitoneally with depleting anti-CD4 monoclonal antibody (mAb, YTA 3.1, 100 microg/dose, days -1. 0. 1, 2, 3, and 5). Mice were killed 30 days after transplantation. Survival of parathyroid grafts was examined microscopically and human parathyroid hormone in serum was measured by ELISA. All parathyroid grafts survived under kidney capsule and human parathyroid hormone was strongly detected in serum (621 +/- 576 pg/mL) when recipients were treated with short-course treatment of anti-CD4 mAb. Conversely, no parathyroid tissue was seen microscopically in any recipient mice without anti-CD4 mAb treatment. Human parathyroid hormone was undetectable by ELISA in naive mice and mice transplanted with human parathyroid tissue without short-course treatment of anti-CD4 mAb. Xenogeneic human parathyroid tissue survived and functioned in mice treated with short-course treatment of anti-CD4 mAb.

Animals↗

Evidence that non-deletional mechanisms are responsible for inducing and maintaining unresponsiveness after intrathymic injection of non-professional antigen presenting cells.

INTRODUCTION: Intrathymic inoculation of donor alloantigen and concomitant immunosuppressive treatment can induce immune unresponsiveness to alloantigen. To examine the role of non-deletional mechanisms in the development of unresponsiveness, fractionated splenocytes were injected into only 1 lobe of the thymus. METHODS AND RESULTS: Untreated CBA (H2(k)) mice or controls pre-treated with anti-CD4 monoclonal antibody alone (on Day -28 and -27 relative to transplantation) acutely rejected C57BL/10 (H2(b)) cardiac allografts. Intrathymic inoculation of unfractionated splenocytes, resting B (rB) cells, or dendritic cells into both thymic lobes with the antibody resulted in indefinite survival of cardiac allografts. In contrast, when donor rB cells or dendritic cells were delivered into a single lobe of the thymus with the antibody, only rB cells induced indefinite prolongation of graft survival; unfractionated splenocytes or dendritic cells were markedly less effective. Mice that had 1 of the 2 thymic lobes removed were able to reject grafts even when treated with the antibody 27 days before transplantation. Therefore, T-cell export from 1 thymic lobe was sufficient to induce graft rejection. Finally, adoptive transfer of splenocytes from mice with long-term surviving primary grafts resulting from the intrathymic injection of rB cells significantly prolonged a graft from the same donor strain in a naive syngeneic recipient. CONCLUSION: Taken together, these data suggest that regulatory mechanisms generated by intrathymic injection of a non-professional antigen presenting cell, in this study donor rB cells, suppressed the rejection response mediated by T cells exported from the uninjected lobe.

Animals↗

Overexpression of heme oxygenase-1 protects allogeneic thyroid grafts from rejection in naive mice.

BACKGROUND: Endocrine allografts are an option for the treatment of endocrine failure. METHODS: One lobe of the thyroid was transplanted under the kidney capsule. RESULTS: C57BL/10 (H2(b)) thyroids were rejected in naive CBA (H2(k)) mice within 14 days after transplantation. When mice were treated with anti-CD4 monoclonal antibodies (mAb), all grafts survived for more than 60 days. The first grafts still survived after second C57BL/10 or Balb/c (H2(d)) thyroid grafts that were transplanted into the same recipients were rejected acutely, which suggests that the primary grafts were modified under anti-CD4 mAb treatment. To confirm this hypothesis, C57BL/10 thyroid grafts from anti-CD4 mAb-treated mice were retransplanted. All grafts survived in naive mice; this correlated with the overexpression of heme oxygenase-1 (HO-1) in the grafts. Next, an inhibitor of HO-1 (zinc protoporphyrin) or control compound (copper protoporphyrin) was injected intraperitoneally after transplantation of C57BL/10 thyroid grafts into the primary CBA recipients that had been treated with anti-CD4 mAb. The grafts in mice that had been treated with zinc protoporphyrin, but not copper protoporphyrin, were rejected when retransplanted to naive recipients. CONCLUSIONS: Overexpression of HO-1 correlated with the protection of fully allogeneic thyroid grafts from rejection when retransplanted into naive recipients.

Animals↗

Alternating combination chemotherapy C-MOPP (cyclophosphamide, vincristine, procarbazine, prednisone) and ABVd (adriamycin, bleomycin, vinblastine, dacarbazine) in clinical stage II-IV Hodgkin's disease: a multicenter phase II study (JCOG 8905). The Lymphoma Study Group of the Japan Clinical Oncology Group.

BACKGROUND: The main form of cytotoxic treatment for advanced Hodgkin's disease (HD) is conventional dose multiagents chemotherapy. As HD is not common in Japan, we conducted a phase II study of the commonly used combination chemotherapy (CCT) regimen established in the West for Japanese patients with advanced HD to confirm the efficacy and safety. METHOD: Between October 1989 and February 1993, a multicenter phase II study of alternating CCT C-MOPP (cyclophosphamide, vincristine, procarbazine, prednisone) and ABVd (adriamycin, vinblastine, bleomycin, dacarbazine) to evaluate its clinical usefulness for clinical stage (cS) II-IV HD was conducted by the Lymphoma Study Group of the Japan Clinical Oncology Group. RESULTS: Seventy-nine previously untreated patients were enrolled in the study. For 67 eligible patients, the response rate was 92.5% with 83.6% complete response (CR). For 40 cS II and 27 cS III/IV patients the response rate was 95.0% with 90.0% CR and 88.9% with 74.1% CR, respectively. The overall 5-year survival rate was 84.8%. Those of cS II and cS III/IV were 92.5 and 73.1%, respectively. There was no significant difference between cS II and cS III/IV (p = 0.1025). The progression-free 4-year survival rate was 72.8%. Those of cS II and cS III/IV were 77.5 and 65.7%, respectively. There was no significant difference between cS II and cS III/IV (p = 0.2483). Grade 4 toxicity by the criteria of the World Health Organization consisted of leukocytopenia in 28.4% of patients. There was GPT elevation in 4.5%, nausea/vomiting in 11.9% and CNS in 1.5% of patients, but there was no treatment-related death. CONCLUSION: The C-MOPP/ABVd regimen for Japanese patients with advanced HD is considered to be one of the effective CCTs according to the results of the present phase II study.

Adolescent↗

Endoscopic resection of thyroid tumors by the axillary approach.

One of the problems of surgery in the neck is the scar. Endoscopic surgery has recently been applied to cervical exploration and the scars of the neck are small and inconspicuous, but a few patients still complain of it. For this reason, we developed a technique of endoscopic resection of thyroid tumors using an axillary approach. This approach does not leave a scar on the neck or the chest, and the small scar in the axilla is completely covered by the patient's arm in a natural manner. Furthermore, the complications such as hypercapnia, respiratory acidosis, subcutaneous empysema, air embolism and sensory loss in the neck region are minimized, because the working surgical space is small and procedures can be performed with CO2 insufflation levels below 4 mmHg. We believe that endoscopic surgery by the axillary approach will find a role in the treatment of thyroid tumors

Endoscopy↗

Evidence for immune regulation in the induction of transplantation tolerance: a conditional but limited role for IL-4.

Most experimental models of allograft tolerance depend on manipulation of immune responses at the time of transplant. In such systems, the graft itself probably plays an important role in the induction of unresponsiveness but as a consequence may suffer immune mediated damage. Ideally, recipients would be made specifically unresponsive before transplant such that the graft is protected from the outset. In this report, we demonstrate that CBA mice pretreated with donor-specific transfusion plus anti-CD4 Ab 28 days before transplant accept cardiac allografts indefinitely without further intervention. Adoptive transfer of spleen cells from mice with long term surviving grafts results in donor-specific graft acceptance in naive secondary recipients, indicating that tolerance in this system involves immuneregulation. Regulation develops as a result of the pretreatment protocol alone, since transfer of cells from pretreated but untransplanted mice to naive recipients also leads to prolonged allograft survival without additional therapy. Neutralizing IL-4 at the time of tolerance induction had no effect on graft outcome in primary recipients. However, removal of IL-4 from the adoptive transfer donors at the time of tolerance induction prevented long term engraftment in the majority of secondary recipients. Our data demonstrate that pretreatment of transplant recipients can establish immune regulation powerful enough to override the responses of an intact immune repertoire and that under stringent conditions at least, development of this regulatory population may in part be dependent on IL-4.

Adoptive Transfer↗

Candida albicans pathogenicity: a proteomic perspective.

Candida albicans is an opportunistic fungus which causes both superficial infections and life-threatening systemic candidiasis in immunocompromised hosts such as AIDS patients, people with cancer, or other immunosuppressed individuals. Virulence factors for this fungus include the ability to adhere to host tissues, production of tissue damaging secreted enzymes, and changes in morphological form that may enhance tissue penetration and avoidance of immune surveillance. Treatment of candidiasis patients is hampered by a limited choice of antifungal agents and the appearance of clinical isolates resistant to azole drugs. Proteome analysis involves the separation and isolation of proteins by two-dimensional gel electrophoresis and their identification and characterization by mass spectrometry. The systematic application of this methodology to C. albicans is in its infancy, but is progressing rapidly. Comparing protein profiles between avirulent and virulent C. albicans strains, between drug-sensitive and -resistant strains, or between different morphological forms, could identify key control and effector proteins. There are difficulties, however, associated with the display of low abundance and cell envelope-associated proteins and the choice of conditions for obtaining suitable C. albicans cells. This article describes the potential of applying proteome analysis to C. albicans in order to better understand pathogenicity and identify new antifungal targets.

Candida albicans↗

Silicone prosthesis prevents vertigo due to the defect at the mastoid process after mastoidectomy: a clinical report.

This clinical report describes a 64-year-old woman with a bony defect in the mastoid process after mastoidectomy and who experienced vertigo on cold and windy days during winter. The patient noticed that packing a piece of paper or cotton into the defect prevented the vertigo. The patient refused surgical repair, so a silicone prosthesis was fabricated to fill the defect completely. Electronystagmography confirmed the effectiveness of the prosthesis to prevent nystagmus. Although surgical repair is ideal, prosthesis repair of the defect may prove to be effective in some patients.

Electronystagmography↗

Effects of central and peripheral injection of leptin on food intake and on brain Fos expression in the Otsuka Long-Evans Tokushima Fatty rat with hyperleptinaemia.

Hyperleptinaemia is observed in obese animals and humans, suggesting that leptin resistance rather than leptin deficiency is a characteristic feature of obesity. This study was designed to determine whether peripherally or centrally administered leptin is effective on the short-term food intake and expression of Fos protein in the hypothalamus in the Otsuka Long-Evans Tokushima Fatty (OLETF) or Long-Evans Tokushima Otsuka (LETO) rat, as a control. The OLETF rat exhibits a polygenic syndrome of hyperphagia, obesity, hyperinsulinaemia, and hyperglycaemia. Male OLETF rats of 5, 8, and 14 weeks of age became heavier than LETO rats. Serum leptin concentrations were not significantly different between LETO and OLETF rats at the age of 5 weeks, but in 8- and 14-week-old OLETF rats were increased to 3.4 and 2.9 times those of LETO rats, respectively. The 8-week-old OLETF and LETO rats were given intraperitoneal (i.p.) injections with recombinant mouse leptin to measure the kinetics. There was a dramatic increase in plasma leptin concentration at 1 h, a decline by 3 h, and the concentrations 6 h after injection were similar to the basal levels. There were no significant difference between OLETF and LETO rats. In LETO rats at 5, 8 and 14 weeks of age, i.p. injection of leptin significantly decreased food intake. Whereas 5-week-old OLETF rats responded to leptin with a decrease in food intake, 8- and 14-week-old OLETF rats became resistant to peripherally administered leptin. In contrast, intracerebroventricular (i.c.v.) injections of leptin were very effective in inhibiting food intake in both OLETF and LETO rats at 14 weeks of age. Intraperitoneal injection of leptin in the LETO rats at each age increased the number of Fos-positive nuclei detected in the ventromedial hypothalamic (VMH), the dorsomedial hypothalamic (DMH) and arcuate nuclei, whereas there was no significant increase in the number of cells expressing c-fos protein in the hypothalamus of the 8- and 14 week-old OLETF rats with hyperleptinaemia. On the other hand, increased expression of c-fos protein in the VMH, DMH and arcuate nuclei following i.c.v. injection of leptin was observed in both OLETF and LETO rats at 5, 8 and 14 weeks of age. These data demonstrated that obese OLETF rats are peripherally leptin resistant, while they retain sensitivity to centrally administered leptin.

Animals↗

Alternating combination chemotherapy COP (cyclophosphamide, vincristine, prednisone) and MP (melphalan, prednisone) in multiple myeloma: a multicenter phase II study (JCOG8906). Lymphoma Study Group of the Japan Clinical Oncology Group.

BACKGROUND: The main form of cytotoxic treatment for multiple myeloma (MM) is conventional dose chemotherapy at present. METHOD: Between November 1989 and December 1991, a multicenter phase II study of alternating conventional dose combination chemotherapy (CCT) with COP (cyclophosphamide, vincristine, prednisone) and MP (melphalan and prednisone) to evaluate its clinical usefulness for overt MM patients was conducted by the Lymphoma Study Group of the Japan Clinical Oncology Group (JCOG). RESULTS: Eighty-one previously untreated patients were enrolled in the study. For 69 eligible patients, the response rate was 50.7% [95% confidence interval (CI) 38.4-63.0%]. The median survival time was 38.5 (95% CI 32.0-44.4) months. The survival rate at 3 and 5 years was 50.7 and 27.3%, respectively. Grade 4 toxicity by the criteria of the World Health Organization consisted of anemia in eight patients, leucocytopenia in three, cardiac in one and hepatic in two, but there was no treatment-related death. CONCLUSION: The COP-MP regimen for overt MM is thought to be one of the effective CCTs according to the results of the present phase II study.

Adult↗

Long-term follow-up results of adult patients with acute lymphocytic leukemia or lymphoblastic lymphoma treated with short-term, alternating non-cross-resistant chemotherapy: Japan Clinical Oncology Group Study 8702. Lymphoma Study Group.

BACKGROUND: Patients with acute lymphocytic leukemia (ALL) and those with lymphoblastic lymphoma (LBL) have overlapping clinical and immunophenotypic features and they have been treated with the same or very similar chemotherapy regimens. The goal of this multi-institutional phase II trial was to evaluate the therapeutic efficacy of a short-term, six-drug chemotherapy regimen for adult patients with untreated ALL or LBL. METHODS: Forty-six eligible patients, 41 with ALL and five with LBL, were treated with a short-term (planned total therapy duration; 36-38 weeks), simplified chemotherapy program; two courses of VEPA-L (vincristine, cyclophosphamide, prednisolone, doxorubicin, I-asparaginase plus intrathecal methotrexate and prednisolone) followed by four courses of M-VEPA (methotrexate plus VEPA), without the traditional maintenance therapy using daily 6-mercaptopurine and weekly methotrexate. RESULTS: Thirty-six (78%; 95% confidence interval 64-89%) of the 46 eligible patients achieved complete remission (CR). Among the 36 patients who achieved CR, four (11%) died of treatment complications, 26 (72%) relapsed and six (17%) remain alive in continuous CR. The median survival for all 46 eligible patients is 14 months and the median disease-free survival (DFS) for the 36 patients who achieved CR is 11 months. The estimate of the proportion of survival at 7 years of all 46 eligible patients is 15% at a median follow-up time of 96 months and that of DFS of the 36 patients achieving CR is 17% at a median follow-up time of 93 months. Subgroup analysis showed that an elevated serum C-reactive protein (CRP) level, age of 30 years or older, the presence of B-symptom and T-cell phenotype were likely to be associated with shortened survival. Although the observed CR rate (78%) is within the range of satisfaction, the long-term survival rate (15%) is inferior to those of published programs incorporating maintenance therapy. CONCLUSIONS: A fraction of adult patients with ALL or LBL are curable with a short-term, six-drug chemotherapy regimen. However, this simplified therapy of shorter duration cannot be recommended.

Adolescent↗

Specific chromosome alterations in fluconazole-resistant mutants of Candida albicans.

The exposure of Candida albicans to fluconazole resulted in the nondisjunction of two specific chromosomes in 17 drug-resistant mutants, each obtained by an independent mutational event. The chromosomal changes occurred at high frequencies and were related to the duration of the drug exposure. The loss of one homologue of chromosome 4 occurred after incubation on a fluconazole medium for 7 days. A second change, the gain of one copy of chromosome 3, was observed after exposure for 35 or 40 days. We found that the mRNA levels of ERG11, CDR1, CDR2, and MDR1, the candidate fluconazole resistance genes, remained either the same or were diminished. The lack of overexpression of putative drug pumps or the drug target indicated that some other mechanism(s) may be operating. The fluconazole resistance phenotype, electrophoretic karyotypes, and transcript levels of mutants were stable after growth for 112 generations in the absence of fluconazole. This is the first report to demonstrate that resistance to fluconazole can be dependent on chromosomal nondisjunction. Furthermore, we suggest that a low-level resistance to fluconazole arising during the early stages of clinical treatment may occur by this mechanism. These results support our earlier hypothesis that changes in C. albicans chromosome number is a common means to control a resource of potentially beneficial genes that are related to important cellular functions.

Aneuploidy↗

Evidence for a potential role for HDL as an important source of cholesterol in human adrenocortical tumors via the CLA-1 pathway.

CLA-1, a human homologue of rodent scavenger receptor class B1 (SR-B1), has been identified as a receptor for high density lipoprotein (HDL) and is highly expressed in the adrenal gland. Several studies have indicated that HDL might be a source of cholesterol for steroidogenesis in the adrenal gland. In this study, we show that ACTH and its second messenger cAMP stimulated CLA-1 protein expression in a human adrenocortical cell line. We also determined whether CLA-1 plays an important role in steroidogenesis by investigating CLA-1 expression levels in various adrenal tumors including the adenomas of Cushing's and Conn's syndrome. Western blot analysis showed that CLA-1 expression was much higher in the tumors of Cushing's syndrome than in non-tumor lesions of Conn's syndrome and pheochromocytoma. We were able to detect a strong CLA-1 signal in tumors of Conn's syndrome, too. On the other hand, much less CLA-1 expression was detected in Cushing's adenoma adjacent adrenal glands. The immunohistochemical analysis showed that CLA-1 was expressed in the outer region of the adrenal cortex mainly in plasma membranes of the cortical cells but not in the medulla. These findings demonstrated for the first time that ACTH increased CLA-1 protein in cultured human adrenocortical cells, and that cortisol- and aldosterone-secreting adenomas had high CLA-1 proteins in their cell surfaces.

8-Bromo Cyclic Adenosine Monophosphate↗