Biomedical subjects

M Namisato

Publications and source records attributed to M Namisato.

10 recordsLinked to original sources

PubMed2005

Polymorphism of the 5' flanking region of the IL-12 receptor beta2 gene partially determines the clinical types of leprosy through impaired transcriptional activity.

BACKGROUND: Individual differences in T cell responsiveness to interleukin 12 (IL-12), resulting from inherited factors, may be responsible for differences in the intensity of cell mediated immune (CMI) responses in patients with leprosy, a disease with a wide clinical spectrum. AIM: Polymorphisms in the 5' flanking region of the IL12RB2 gene were analysed to determine potential immunogenetic factors affecting CMI responses, using leprosy as a model. METHODS: Polymorphisms in the 5' flanking region of IL12RB2 were examined using direct sequencing techniques, and allele frequencies between patients with lepromatous leprosy and patients with tuberculoid leprosy were compared. The effect of these single nucleotide polymorphisms (SNPs) on IL12RB2 expression was estimated using the dual luciferase reporter gene assay in Jurkat T cells. RESULTS: Several SNPs, including -1035A>G, -1023A>G, -650delG, and -465A>G, were detected within the 5' flanking region of IL12RB2. The frequency of haplotype 1 (-1035A, -1023A, -650G, -464A) was high in the general Japanese population, but was significantly lower in lepromatous patients compared with tuberculoid patients and healthy controls. Reporter gene assays using Jurkat T cells revealed that all haplotypes carrying one or more SNP exhibited a lower transcriptional activity compared with haplotype 1. CONCLUSION: SNPs within the 5' flanking region of IL12RB2 affect the degree of expression of this gene and may be implicated in individual differences in CMI responsiveness to mycobacterial antigens, leading to lepromatous or tuberculoid leprosy.

5' Flanking Region↗

PubMed2000

[Guideline for the treatment of Hansen's disease in Japan].

Ad hoc committee of Japanese Leprosy Association recommends standard treatment protocol of leprosy in Japan, which is a modification of World Health Organization's multidrug therapy (WHO/MDT, 1997). For paucibacillary (PB) leprosy, 6 months treatment by rifampicin and dapsone (MDT/PB) is enough. However, for high bacterial load multibacillary (MB) leprosy, 12 months treatment seems insufficient. Thus, (A) For MB with bacterial index (BI) > or = 3 before treatment, 2 years treatment by rifampicin, dapsone and clofazimine (MDT/MB) is necessary. (A-1) When satisfactory decrease of BI (BI value decrease > or = 2 steps, or final BI < 3) is obtained after completion of 2 years MDT/MB, maintenance therapy by dapsone and clofazimine is recommended until BI negativity and loss of active lesions. (A-2) When BI decrease is not satisfactory (BI value decrease < 2 steps, or final BI > or = 3), MDT/MB should be continued until BI negativity and loss of active lesions. (B) For MB with BI < 3 or fresh MB (less than 6 months after the onset of the disease) with BI > or = 3, 1 year treatment by rifampicin, dapsone and clofazimine (MDT/MB) is necessary. (B-1) When BI become negative and active lesion is lost within one year, no maintenance therapy is necessary. (B-2) When BI is still positive or active lesion is remaining, additional therapy with MDT/MB for one more year is recommended. Brief summary of diagnosis, purpose of therapy, character of drugs, and prevention of deformity is also described.

Drug Therapy, Combination↗

PubMed2000

Human leukocyte antigens in forms of leprosy among Japanese patients.

Human leukocyte antigens (HLA) class II alleles were analyzed among Japanese leprosy patients to ascertain whether immunogenetic differences exist among the leprosy classification forms of Ridley and Jopling. Ninety-three unrelated Japanese leprosy patients (21 lepromatous, 24 borderline lepromatous, 17 mid-borderline, 26 borderline tuberculoid, 5 tuberculoid) and 114 healthy control subjects were investigated. The frequencies of HLA-DRB1*1501, -DRB5*0101, -DQA1*0102 and DQB1*0602 were significantly increased in all of the Japanese leprosy patients. The frequencies of HLA-DRB1*0405, -DQA1*03 and -DQB1*0401 were significantly decreased in the Japanese patients after correction of the p value. Conversely, there were no significantly different distributions of the HLA-DRB1, -DRB5, -DQA1, DQB1 alleles in the five subgroups of these patients. We conclude that HLA class II alleles were not associated with the form of leprosy. Other HLA, a non-HLA gene, and/or environmental factors may play a critical role in the different manifestations of leprosy.

Cytotoxicity Tests, Immunologic↗

PubMed2000

Serious side effects of rifampin on the course of WHO/MDT: a case report.

A male born in 1935 was diagnosed as having lepromatous leprosy when he was 17 years old. In addition to dapsone (DDS) monotherapy, he had been treated with rifampin (RMP) for 2 terms: first with 450 mg a day for 2 years when he was 39 years old; second with 150 mg a day for 2 months after a 1-year interval from the first regimen. During these entire courses with RMP, no complication was noted. When he was 64 years old in 1999, a diagnosis of relapsed borderline tuberculoid (BT) leprosy was made, and he was started on the multibacillary (MB) regimen of the World Health Organization multidrug therapy (WHO/MDT). After the third dose of monthly RMP, he developed a flu-like syndrome and went into shock. A few hours later, intravascular hemolysis occurred followed by acute renal failure. He was placed on hemodialysis for 7 series and recovered almost completely about 2 months later. The immune complexes with anti-RMP antibody followed by complement binding may have accounted for these symptoms. Twenty-four reported cases of leprosy who had developed side effects of RMP under an intermittent regimen were analyzed; 9 of the cases had had prior treatment with RMP but 15 had not. Adverse effects were more likely to occur in MB cases and were more frequent during the first 6 doses of intermittent regimens. The cases with prior treatment with RMP had had a higher incidence of serious complications such as marked hypotension, hemolysis and acute renal failure. However, many exceptions were also found, and we could not verify any fully dependable factor(s) to predict the side effects of RMP. More field investigation is desirable, and monthly administration of RMP must be conducted under direct observation through the course of WHO/MDT.

Adrenal Cortex Hormones↗

PubMed2000

A Mycobacterium leprae isolate resistant to dapsone, rifampin, ofloxacin and sparfloxacin.

Mycobacterium leprae were isolated from a Japanese patient, and susceptibility to antileprosy drugs was examined by the mouse foot pad method. The isolate was susceptible to clofazimine and clarithromycin, and resistant to dapsone, rifampin, ofloxacin and sparfloxacin. Mutations were identified in the genes associated with resistance to these drugs. The risk of the emergence of leprosy with multidrug resistance is emphasized.

Animals↗

PubMed1997

Transepidermal elimination of lepromatous granuloma: a mechanism for mass transport of viable bacilli.

A 35-year-old male with lepromatous leprosy showed significant progression of the disease on initial examination. Along with typical lepromatous skin lesions, many scar-forming lesions were present, mainly on his extremities. Some lesions showed erosive surfaces. From clinicopathological findings, these lesions were suspected to be due to the partial excretion of intradermal lepromatous granulomata by 'transepidermal elimination'. Increased local volume, which might be due mainly to rapidly growing lepromatous infiltration before chemotherapy, is suspected of triggering this phenomenon. There is no doubt that many fresh Mycobacterium leprae were included in these excretions. After the initiation of chemotherapy, no new scar-forming lesions were observed.

Adult↗

PubMed1996

[HLA class II alleles and leprosy (Hansen's disease) classified by WHO-MDT criteria].

Human leukocyte antigens (HLA) class II alleles were analyzed in Japanese leprosy patients to ascertain whether immunogenetic differences exist among the forms of leprosy in classification of World Health Organization-recommended multidrug therapy (WHO-MDT). The subjects were 86 unrelated Japanese leprosy patients, including 62 multibacillary leprosy (MBL), 24 paucibacillary leprosy (PBL). Controls were 114 unrelated healthy subjects. Genotyping of HLA class II alleles was performed by using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (RFLP) methods. The frequencies of HLA-DRB1* 1501, * 1502 and DRB5* 0101,* 0102 and DQA1* 0102 and DQB1* 0602 were significantly increased in the whole patients (44.2%, 34.9%, 44.2%, 34.9%, 53.4% and 41.9%, respectively) as compared with the control subjects (14.0%, 21.1%, 14.0%, 21.1%, 27.2% and 13.2%, respectively). On the other hand, the frequencies of HLA-DRB1* 0405, * 0803, * 0901 and DQA1* 03 and DQB1* 0401 were significantly decreased in the whole patients (10.5%, 5.8%, 16.3%, 41.9% and 9.3%, respectively) as compared with the control subjects (29.8%, 17.5%, 30.7%, 78.1% and 29.8%, respectively). When MBL and PBL patients were compared, the frequencies of HLA-DRB1* 1501, DRB5* 0101 and DQB1* 0602 were significantly increased in the MBL patients (51.6%, 51.6% and 48.4%, respectively) as compared with the PBL patients (25.0%, respectively). Our results suggest that HLA-DRB1* 1501, DRB5* 0101 and DQB1* 0602 contribute to the susceptibility to the Japanese MBL.

Aged↗

PubMed1995

[The dermal connective tissue of long quiescent leprosy patients. Part 2. Comparison of the volumes of collagen with those of elastic fibers].

We studied dermal connective tissue of leprosy patients(Pa) in inactive condition. The dermal thickness(D) and the volumes of collagen and elastic fibers were measured utilizing automated computerized image analyzer. The length of each elastic fibers(E) in lower legs were also measured. The E in upper dermis of forearms were observed microscopically. All these were compared with age-matched control(Co). We got the following results accordingly. There was a relative increase of E in Pa's limb skin in spite of greatly decreased dermal thickness and fibrous components. The influence of sun exposure could not be recognized in this result. Each elastic fibers of Pa were longer than that of Co. The increased E in upper dermis was evident in Co's forearms, but not in Pa's. From our results, it is conceivable that the Pa's E either outlast or are overproduced exceedingly the collagen fibers. The factors that may account for these results are remained to be clarified.

Aged↗

PubMed1995

[Uveitis in leprosy patients].

We examined 24 dermatologically cured leprosy patients with ongoing uveitis (UV+) and 22 age and type matched controls (UV-) to study the late phase leprous UV. All patients have been skin smear negative for more than 10 years. The history of chemotherapy, 5 years before and after a accomplishing bacterial negativity, was evaluated and represented by "SCORE". It was found that anti-PGL-I and anti-LAM-B antibodies were significantly higher in UV+ group compared to the controls. The mean SCORE of chemotherapy in UV+ group was significantly lower than in the controls. Iris pearls were seen in 10 cases or 42% out of 24 UV+ patients. No iris pearls were seen in control group. These results suggest that insufficient chemotherapy and consequent incomplete elimination of bacilli are the risk factors for leprous UV in the quiescent stage of the disease.

Aged↗

PubMed1994

[The dermal connective tissue of leprosy patients. Part 1. The elastic fibers and the skin appendages].

Leprosy patients who are keeping long quiescent conditions show some characteristic changes clinically on their skins. The elastic fibers and skin appendages are important factors for the peculiar skin characters. We calculated the collagen and elastic fibers in the limbs and redundant facial skins of leprosy patients by automated computerized image analyser. Histopathological studies of these samples were also done. All cases were over sixty years old and many of them were in quiescent conditions. The control cases were taken from the same parts of age matched normal skins. We found the dermal thickness of lower legs of patients was significantly lower than that of controls. The amount of collagen fibers had tendensy of decrease accompanied with decreased dermal thickness, but the elastic fibers of leprosy patients did not show the same tendensy. In the patients' skin, the elastic fibers arranged irregularly, sometimes fragmented and focally coagressed. Skin appendages were greatly decreased and intraepidermal pores of sweat ducts were almost disappeared, but many sweat glands have survived. Of the facial skins, only 1 case showed a compatible feature with solar elastosis. We concluded that the dermal elastic fibers of leprosy patients had characteristic features. The types of leprosy, duration periods of active condition, destructed dermal structures, all these factors were suspected to have some relations with these phenomena.

Aged↗