51
|
Akiyama M, Takizawa Y, Kokaji T, Shimizu H. Novel mutations of TGM1 in a child with congenital ichthyosiform erythroderma. Br J Dermatol 2001; 144:401-7. [PMID: 11251583 DOI: 10.1046/j.1365-2133.2001.04037.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report novel mutations in the transglutaminase (TGase) 1 gene (TGM1) in a Japanese boy with non-bullous congenital ichthyosiform erythroderma (NBCIE). The patient showed fine, grey or light-brown scales on an erythematous skin. An in situ TGase activity assay detected markedly reduced TGase activity in the patient's epidermis. Electron microscopy revealed incomplete thickening of the cornified cell envelope during keratinization in the epidermis. Sequencing of the entire exons and exon-intron borders of TGM1 revealed that the proband was a compound heterozygote for two novel mutations, 9008delA and R388H. In lamellar ichthyosis, most previously reported TGM1 mutations have been located in the central core domain or upstream of the TGase 1 molecule. In the present NBCIE patient, the frameshift mutation 9008delA resulting in a premature termination codon at the tail of the TGase 1 peptide was in the beta-barrel 2 domain (C-terminal end domain) of the peptide, far from the active sites of the TGase 1 molecule, and the mis-sense mutation R388H was in the core domain.
Collapse
|
52
|
Muto G, Satoh J, Muto Y, Takahashi K, Nakazawa T, Sagara M, Miyaguchi S, Fukuzawa M, Qiang X, Sakata Y, Takizawa Y, Li Y, Bando S, Housai T, Tamagawa A, Toyota T. Adjuvant-induced improvement of glucose intolerance in type 2 diabetic KK-Ay mice through interleukin-1 and tumor necrosis factor-alpha. Clin Immunol 2000; 97:259-65. [PMID: 11112365 DOI: 10.1006/clim.2000.4928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We reported that administration of complete Freund's adjuvant (CFA) improved glucose tolerance test (GTT) results in obese diabetic KK-Ay mice. In this study, we investigated its mechanism. An injection with CFA remarkably improved GTT for more than a week in KK-Ay mice, although insulin response was not changed compared with saline controls. The hypoglycemic effect of insulin was significantly, but partially, potentiated in the CFA-treated mice compared with the controls, suggesting that CFA stimulated insulin-mediated and non-insulin-mediated glucose disposal. Improvement in the GTT with CFA was partially transferable to nontreated mice by peritoneal exudative cells, but not spleen or lymph node cells. Pretreatment with anti-interleukin (IL)-1 alpha and -1 beta antibodies or anti-tumor necrosis factor (TNF)-alpha antibody significantly abrogated the improvement in the GTT with CFA. The results indicate that CFA-induced improvement in glucose intolerance in KK-Ay mice was mediated at least by IL-1 and TNF-alpha.
Collapse
|
53
|
Murata T, Masunaga T, Shimizu H, Takizawa Y, Ishiko A, Hatta N, Nishikawa T. Glycine substitution mutations by different amino acids in the same codon of COL7A1 lead to heterogeneous clinical phenotypes of dominant dystrophic epidermolysis bullosa. Arch Dermatol Res 2000; 292:477-81. [PMID: 11142768 DOI: 10.1007/s004030000162] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Dystrophic epidermolysis bullosa (DEB), caused by mutations in the gene encoding type VII collagen (COL7A1), is known to show heterogeneous clinical phenotypes. Certain correlations between the nature or position of COL7A1 mutations and the resultant DEB phenotypes have been suggested, although such relationships may be more complex than initially thought. The purpose of the present study was to clarify the molecular basis of two different subtypes of dominant DEB (DDEB), EB pruriginosa and classical type. Interestingly, we found that both cases were caused by a missense glycine substitution mutation by different amino acids in the same codon of COL7A1 (G2028R and G2028A). These results further support the notion that different glycine substitution mutations in the same codon can lead to heterogeneous clinical phenotypes of DDEB, EB pruriginosa and classical type.
Collapse
|
54
|
Takizawa Y, Pulkkinen L, Chao SC, Nakajima H, Nakano Y, Shimizu H, Uitto J. Mutation report: complete paternal uniparental isodisomy of chromosome 1: a novel mechanism for Herlitz junctional epidermolysis bullosa. J Invest Dermatol 2000; 115:307-11. [PMID: 10951251 DOI: 10.1046/j.1523-1747.2000.00052.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Uniparental disomy denotes a situation when an individual has inherited two copies of a specific chromosome from a single parent. Uniparental disomy has been demonstrated to be involved in the pathogenesis of recessively inherited diseases in rare cases. Here we report a patient of Japanese origin with Herlitz junctional epidermolysis bullosa (OMIM no. 226700), who died at the age of 8 mo from complications of the disease. The mutation analysis revealed that the proband was homozygous for a nonsense mutation C553X in the LAMC2 gene encoding the gamma2 chain of laminin 5. The father was a heterozygous carrier of this mutation whereas the mother had two normal alleles of this gene. The patient showed homozygosity for 15 known intragenic polymorphisms in the LAMC2 gene. Furthermore, genotype analysis, performed from the parents and the proband, using 16 microsatellite markers spanning the entire chromosome 1, revealed that the patient was homozygous for all markers tested, and that these alleles originated from the father. Among the 16 markers, eight were fully informative for the absence of the maternal chromosome 1 in the proband, suggesting that the patient had complete paternal isodisomy of this chromosome. Thus, the Herlitz junctional epidermolysis bullosa phenotype in this patient is caused by homozygous LAMC2 mutation C553X that is of paternal origin and results from nondisjunction and uniparental disomy involving monosomy rescue. This is a novel mechanism resulting in Herlitz junctional epidermolysis bullosa and has implications for assessment of the risk in subsequent pregnancies.
Collapse
|
55
|
Hisamatsu S, Inoue Y, Miyamoto K, Takizawa Y. Free water 3H concentration in diet samples collected from 1969 to 1988 in Akita, Japan. HEALTH PHYSICS 2000; 79:187-191. [PMID: 10910389 DOI: 10.1097/00004032-200008000-00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fallout 3H concentrations in diet samples collected from 1969 to 1988 in Akita Prefecture are reported. Since the data for samples from the 1960's and 1970's are important to understand the long-term movement of 3H in the environment, we searched for old diet samples. Recently, diet samples collected in Akita Prefecture during 1969-1982 were found and subjected to 3H analysis. The samples were originally gathered for nutrition survey programs and had been stored in a refrigerated warehouse at -20 degrees C until we located them. The free water 3H concentrations in the samples were measured and are reported here. The present results are combined with already published data; together they show 3H concentrations exponentially decrease from 1969 to 1988 with an apparent half time of 5.9 y. Levels of diet free water 3H concentrations are also similar to measured and estimated precipitation 3H concentrations in Akita City.
Collapse
|
56
|
Takizawa Y, Hiraoka Y, Takahashi H, Ishiko A, Yasuraoka I, Hashimoto I, Aiso S, Nishikawa T, Shimizu H. Compound heterozygosity for a point mutation and a deletion located at splice acceptor sites in the LAMB3 gene leads to generalized atrophic benign epidermolysis bullosa. J Invest Dermatol 2000; 115:312-6. [PMID: 10951252 DOI: 10.1046/j.1523-1747.2000.00051.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An autosomal recessive disorder, generalized atrophic benign epidermolysis bullosa, is a rare form of nonlethal type junctional epidermolysis bullosa. It is associated not only with skin fragility but also with other unique clinical features including widespread atrophic skin changes, alopecia, reduced axillary and pubic hair, dysplastic teeth, and dystrophic nails. The majority of generalized atrophic benign epidermolysis bullosa cases are caused by mutations in the COL17A1 gene coding for type XVII collagen (or the 180 kDa bullous pemphigoid antigen). Another candidate gene for mutations in some forms of generalized atrophic benign epidermolysis bullosa is LAMB3 encoding the beta3 chain of laminin 5. This report documents compound heterozygosity for novel mutations in LAMB3 of a Japanese patient showing typical clinical features of generalized atrophic benign epidermolysis bullosa. One is an A-to-G transversion at the splice acceptor site of intron 14, which is designated as a 1977-2A-->G mutation; the other is a deletion of 94 bp located at the junction of intron 18 and exon 19, which is a 2702-29del94 mutation. Reverse transcriptase polymerase chain reaction analysis suggested skipping of exon 19 in LAMB3 mRNA produced from the allele with 2702-29del94 and impaired stability of the aberrant mRNA transcribed from the second allele with the 1977-2A-->G mutation.
Collapse
|
57
|
Fukuzawa M, Satoh J, Ohta S, Takahashi K, Miyaguchi S, Qiang X, Sakata Y, Nakazawa T, Takizawa Y, Toyota T. Modulation of tumor necrosis factor-alpha production with anti-hypertensive drugs. IMMUNOPHARMACOLOGY 2000; 48:65-74. [PMID: 10822090 DOI: 10.1016/s0162-3109(00)00179-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is well known that some anti-hypertensive drugs affect insulin sensitivity and that tumor necrosis factor-alpha (TNF-alpha) is a mediator of obesity-associated insulin resistance. In this study, we have investigated the effect of anti-hypertensive drugs, calcium (Ca) channel blockers (amlodipine, manidipine and nicardipine), an alpha(1)-blocker (doxazosin), a beta(1)-blocker (metoprolol), and a thiazide diuretic (hydrochlorothiazide), on lipopolysaccharide (LPS)-induced TNF-alpha production. TNF-alpha production, measured with a bioassay and an immunoassay, was evaluated both in vivo and in vitro, by utilizing mice and a human peripheral blood mononuclear cell culture, respectively. Nicardipine, or amlodipine, manidipine and doxazosin significantly inhibited TNF-alpha production in mice at doses more than one or ten times higher than those used clinically, respectively. On the other hand, metoprolol increased TNF-alpha production at doses of more than 10 times those used clinically, whereas hydrochlorothiazide did not alter production of the cytokine. The in vivo effects of these drugs were not necessary parallel to the in vitro effects. Because high doses of these drugs in mice correspond to clinical doses and effects in human, these actions may be related to beneficial and/or harmful effects of these drugs on TNF-alpha mediated diseases, including insulin resistance.
Collapse
|
58
|
Takizawa Y, Kato S, Matsunaga J, Aozaki R, Tomita Y, Nishikawa T, Shimizu H. Electron microscopic DOPA reaction test for oculocutaneous albinism. Arch Dermatol Res 2000; 292:301-5. [PMID: 10929771 DOI: 10.1007/s004030000133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Oculocutaneous albinism (OCA) is an autosomal recessive disorder in which the biosynthesis of melanin is reduced or absent in skin, hair and eyes. Tyrosinase-related OCA (OCA1) is caused by mutations in the tyrosinase gene. Tyrosinase-negative OCA (OCA1A) is the most severe phenotype in which tyrosinase catalytic activity is completely lost, resulting in no mature melanin pigment. Yellow OCA (OCA1B) varies from very little pigment associated with whitish-blond hair to nearly normal pigment with dark-blond hair and skin. We determined the tyrosinase activity in melanocytes by the electron microscopic dihydroxyphenylalanine (EM-DOPA) reaction test using skin samples and analyzed tyrosinase gene mutations in nine Japanese patients with OCA. In 18 alleles of nine patients, the OCA1A-associated mutations, P310insC, R77Q and R278X, were found in seven, three and one alleles, respectively. Five patients who had these mutations in both alleles showed white hair, blue eyes and white skin and demonstrated no tyrosinase activity by the EM-DOPA reaction test. Three patients who had no tyrosinase gene mutation showed tyrosinase activity and heterogeneous clinical features. One patient in whom only an R77Q OCA1A mutation was found in one allele demonstrated a reduced tyrosinase activity, indicating OCA1B. This patient had white hair at birth, but it had turned blond by the age of 1 year. These results indicate that the EM-DOPA reaction test provides clear information on the status of tyrosinase activity which is essential for the identification of the disease subtype which in turn is important for the prognosis of patients with OCA.
Collapse
|
59
|
Arisawa K, Takahashi T, Nakano A, Liu XJ, Saito H, Takizawa Y, Koba T. [Potential exposure to inorganic mercury in people living near a sewage sludge dumping site: urinary excretion of mercury, subjective symptoms and renal function]. [NIHON KOSHU EISEI ZASSHI] JAPANESE JOURNAL OF PUBLIC HEALTH 2000; 47:134-44. [PMID: 10734728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
OBJECTIVE The purpose of this study was to evaluate the presence of exposure to inorganic mercury and its health effects among people living near a sewage sludge dumping site in Nagasaki Prefecture, Japan. In this area, sewage sludge and industrial waste have been dumped since 1975, and total mercury levels exceeding the water quality standards (0.0006-0.0020 mg/l) have been detected in seeping water and river water since July 1997. METHODS The population for the present study comprised 48 subjects (aged 11-91 years) living near a sewage sludge dumping site and 49 subjects (aged 10-82 years) living in a non-polluted area. In November and December 1998, subjective symptoms of inorganic mercury exposure, history of occupational exposure to inorganic mercury, frequency of fish intake, sources of drinking water and other health habits were inquired by a self-administered questionnaire. Total mercury and total protein levels and N-acetyl-beta-D-glucosaminidase (NAG) activity in morning urine specimens were also measured. RESULTS Among males, the proportion of subjects who complained of tremor in the hands (P = 0.02) and increased irritability (P = 0.10) was higher in the polluted area than in the control area. In addition, the proportion of those who did not report being easily fatigued was lower in the polluted area than in the control area (P = 0.07). Among females there was no significant difference in the prevalence of self-reported symptoms related to the central nervous system disturbance between the two areas. After adjustment for gender and age using logistic regression analysis, the prevalence of increased irritability was significantly higher (P = 0.05) and the proportion of those who did not report being easily fatigued was significantly lower (P = 0.03) in the polluted area than in the control area. However, there was no significant difference in the geometric mean of urinary total mercury concentration (microgram/g creatinine) between the polluted area (0.66, 95% confidence interval [CI] 0.48-0.91 for men and 0.96, 95% CI 0.70-1.33 for women) and the control area (0.81, 95% CI 0.60-1.09 for men and 0.83, 95% CI 0.57-1.22 for women). There was no individual whose total mercury concentration in urine exceeded 30 micrograms/g creatinine, at which level of urinary total mercury toxic effects on the central nervous system have been reported in industrial workers. There was also no significant difference in the geometric means of urinary total protein level and NAG activity. CONCLUSION There was no evidence of excessive exposure to inorganic mercury among residents in the polluted area. Thus, we concluded that the difference in the prevalence of subjective symptoms was not due to the direct effect of exposure to inorganic mercury. To prevent the contamination of water by taking measures against pollution sources, monitoring of the quality of drinking water, and finally to secure safe water supply by public waterworks are required.
Collapse
|
60
|
|
61
|
Takizawa Y, Akiyama M, Nagashima M, Shimizu H. A novel asparagine-->aspartic acid mutation in the rod 1A domain in keratin 2e in a Japanese family with ichthyosis bullosa of Siemens. J Invest Dermatol 2000; 114:193-5. [PMID: 10620137 DOI: 10.1046/j.1523-1747.2000.00817.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ichthyosis bullosa of Siemens is a unique type of congenital ichthyosis characterized by mild hyperkeratosis over the flexural areas and blister formation after mechanical trauma and superficial denuded areas in the hyperkeratotic skin. Recently, mutations in the helix initiation or termination motifs of keratin 2e (KRT2E) have been described in ichthyosis bullosa of Siemens patients. The majority of the mutations reported to date lie in the 2B region. We report a novel amino acid substitution mutation (asparagine-->aspartic acid) in codon 192 at the conserved 1A helix initiation site of the rod domain of KRT2E in a Japanese family with ichthyosis bullosa of Siemens. Our data indicate aspartic acid substitution in codon 192 in the 1A helix initiation site is deleterious to keratin filament network integrity and leads to ichthyosis bullosa of Siemens phenotype.
Collapse
|
62
|
Masunaga T, Shimizu H, Takizawa Y, Uitto J, Nishikawa T. Combination of novel premature termination codon and glycine substitution mutations in COL7A1 leads to moderately severe recessive dystrophic epidermolysis bullosa. J Invest Dermatol 2000; 114:204-5. [PMID: 10620140 DOI: 10.1046/j.1523-1747.2000.00848.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
63
|
|
64
|
Shimizu H, Takizawa Y, Pulkkinen L, Murata S, Kawai M, Hachisuka H, Udono M, Uitto J, Nishikawa T. Epidermolysis bullosa simplex associated with muscular dystrophy: phenotype-genotype correlations and review of the literature. J Am Acad Dermatol 1999; 41:950-6. [PMID: 10570379 DOI: 10.1016/s0190-9622(99)70252-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Epidermolysis bullosa simplex associated with muscular dystrophy (EBS-MD; OMIM# 226670) is an autosomal recessive disorder caused by genetic defects in the plectin gene. Because EBS-MD is relatively rare, and gene defects have been elucidated only in a limited number of patients, the precise phenotype-genotype correlations have not yet been fully elucidated. OBJECTIVE The purpose of this study was to define clinical features of EBS-MD and to clarify its phenotype-genotype correlations. METHODS Clinical, ultrastructural, immunohistochemical, and molecular features of 4 unrelated Japanese patients with EBS-MD were recorded. In addition, 6 cases with defined plectin gene mutations reported in the literature were reviewed. RESULTS In skin of the EBS-MD patients, the blister formation always occurs just above the hemidesmosomes, and expression of plectin is absent or markedly reduced in all cases examined. All 10 patients, including 6 cases in the literature, showed generalized blistering at birth or soon thereafter, and experienced nail deformities. In addition, decayed teeth (5 cases), urethral strictures (3), mild palmoplantar hyperkeratosis (2), infantile respiratory complications (2), alopecia (1), and laryngeal webs (1) were present. All 8 patients who were older than 9 years demonstrated considerable muscle weakness, and the majority of them ended up being wheelchair bound. Among the 10 patients, 7 were products of consanguineous marriage, 9 have premature termination codon (PTC) mutations in both alleles of the plectin gene, and 7 cases were homozygous for the mutation. One patient who is homozygous for a 2719del9 in-frame deletion mutation that resulted in elimination of 3 amino acids, QEA, could still walk at the age of 46 and showed milder clinical severity. CONCLUSION EBS-MD reveals clinical features not only characteristic of EBS and MD, but also other manifestations including urethral, dental, and respiratory complications. The majority of patients are products of consanguineous marriage and have homozygous plectin gene mutations. Whereas patients with PTC mutations in both alleles typically showed severe clinical features of EBS-MD and ended up being wheelchair bound, a homozygous patient for an in-frame deletion mutation showed positive, yet attenuated, plectin expression and milder clinical phenotype. Thus plectin immunofluorescence, combined with identification of the underlying plectin mutations, is of value in predicting the severity of the muscle involvement that occurs later in life of patients with EBS-MD.
Collapse
|
65
|
Eto K, Takizawa Y, Akagi H, Haraguchi K, Asano S, Takahata N, Tokunaga H. Differential diagnosis between organic and inorganic mercury poisoning in human cases--the pathologic point of view. Toxicol Pathol 1999; 27:664-71. [PMID: 10588547 DOI: 10.1177/019262339902700608] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Differences in pathology were found between acute and chronic exposure to methylmercury, mercury vapor, and inorganic mercury. Characteristic pathologic changes produced by organic mercury in the brain have previously been described in patients with Minamata disease. The brains of patients who presented with acute onset of symptoms and died within 2-mo showed loss of neurons with reactive proliferation of glial cells, microcavitation, vascular congestion, petechial hemorrhage, and edema in the cerebral cortices, predominantly in the calcarine, pre- and postcentral, and transverse temporal cortices and in the cerebellar cortex. The neuropathologic changes in the patients with acute onset of symptoms who survived for a long period (>10 yr) were also included neuronal loss with reactive proliferation of glial cells in similar anatomic locations. The neuropathologic changes in patients with inorganic mercury poisoning are quite different. Autopsies performed on 3 individuals with fatal cases of acute inorganic mercury poisoning who were exposed to mercury vapor for about 2 wk revealed diffuse organized pneumonia, renal cortical necrosis, disseminated intravascular coagulopathy, and infarctions in the brain and kidneys. In 2 other patients who worked in mercury mines for about 10 yr and who suffered from chronic inorganic poisoning, no specific lesions were demonstrated in the brain. However, the assay and the histochemistry of mercury revealed that inorganic mercury was present in the brain in all 3 groups irrespective of the brain lesions and the duration of clinical signs.
Collapse
|
66
|
Sasaki Y, Shimizu H, Akiyama M, Hiraoka Y, Takizawa Y, Yamada S, Morishima Y, Yamanishi K, Aiso S, Nishikawa T. A recurrent keratin 14 mutation in Dowling-Meara epidermolysis bullosa simplex. Br J Dermatol 1999; 141:747-8. [PMID: 10583131 DOI: 10.1046/j.1365-2133.1999.03124.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
67
|
Nakamura K, Naruse I, Takizawa Y. A new mass screening method for methylmercury poisoning using mercury-volatilizing bacteria from Minamata Bay. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 1999; 44:100-104. [PMID: 10499995 DOI: 10.1006/eesa.1999.1805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A simplified mass screening method for methylmercury exposure was developed using methylmercury-volatilizing bacteria from Minamata Bay. Some bacteria can transform methylmercury into mercury vapor. Most mercury in the hair is methylmercury, which is readily extracted with HCl solution. Black spots are formed on X-ray film due to the reduction of Ag(+) emulsion with mercury vapor produced by methylmercury-volatilizing bacteria. By exploiting these characteristics, a screening method was developed, whereby the fur of rats injected with methylmercury chloride formed clear black spots on X-ray film, whereas the fur of rats injected with saline did not. Subsequently, 50 human hair samples were examined using this mass screening method. The method identified people who had high mercury concentration, over 20 microg/g. A few thousand hair samples may be screened in a day using this method because it is rapid, simple, and economical. This method, therefore, enables screening of persons with methylmercury poisoning in mercury-polluted areas.
Collapse
|
68
|
Takizawa Y, Rose GJ, Kawasaki M. Resolving competing theories for control of the jamming avoidance response: the role of amplitude modulations in electric organ discharge decelerations. J Exp Biol 1999; 202:1377-86. [PMID: 10210678 DOI: 10.1242/jeb.202.10.1377] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The algorithm for the control of the jamming avoidance response (JAR) of Eigenmannia has been the subject of debate for over two decades. Two competing theories have been proposed to explain how fish determine the correct direction to shift their pacemaker frequency during jamming. One theory emphasizes the role of time-asymmetric beat envelopes, while the other emphasizes the role of amplitude- and phase-difference computations that arise from the differences in spatial geometry of the electric fields of neighboring fish. In repeating earlier experiments, we found that the decision to raise or lower the pacemaker frequency reliably above or below its resting level depends on the latter process, and that frequency deceleration responses to amplitude modulation appear to be sufficient to explain previous experimental results on which the former theory is based. Specifically, fish of the genus Eigenmannia show differential deceleration responses to asymmetric beat envelopes. The deceleration responses do not require phase modulation and show a sensitivity for amplitude modulation depth and selectivity for amplitude modulation rate comparable with that of JARs that are elicited when amplitude- and phase-difference information is available.
Collapse
|
69
|
Takizawa Y, Shimizu H, Rouan F, Kawai M, Udono M, Pulkkinen L, Nishikawa T, Uitto J. Four novel plectin gene mutations in Japanese patients with epidermolysis bullosa with muscular dystrophy disclosed by heteroduplex scanning and protein truncation tests. J Invest Dermatol 1999; 112:109-12. [PMID: 9886273 DOI: 10.1046/j.1523-1747.1999.00461.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Epidermolysis bullosa with muscular dystrophy (EB-MD) is a distinct variant of EB caused by mutations in the plectin gene (PLEC1). In this study, we have examined two Japanese patients with EB-MD using heteroduplex scanning or a protein truncation test for mutation detection analysis. The results revealed that both patients were compound heterozygotes for novel PLEC1 mutations (Q1936X/Q1053X and R2421X/12633ins4), which all caused premature termination of translation of the corresponding polypeptides. These cases, which demonstrate the utility of two complementary mutation detection strategies, add to the repertoire of plectin mutations in EB-MD.
Collapse
|
70
|
Takizawa Y, Shimizu H, Pulkkinen L, Suzumori K, Kakinuma H, Uitto J, Nishikawa T. Combination of a novel frameshift mutation (1929delCA) and a recurrent nonsense mutation (W610X) of the LAMB3 gene in a Japanese patient with Herlitz junctional epidermolysis bullosa, and their application for prenatal testing. J Invest Dermatol 1998; 111:1239-41. [PMID: 9856852 DOI: 10.1038/sj.jid.5600370] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
71
|
Takizawa Y, Shimizu H, Pulkkinen L, Nonaka S, Kubo T, Kado Y, Nishikawa T, Uitto J. Novel premature termination codon mutations in the laminin gamma2-chain gene (LAMC2) in Herlitz junctional epidermolysis bullosa. J Invest Dermatol 1998; 111:1233-4. [PMID: 9856849 DOI: 10.1046/j.1523-1747.1998.00438.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
72
|
Shimizu H, Takizawa Y, Pulkkinen L, Zone JJ, Matsumoto K, Saida T, Uitto J, Nishikawa T. The 97 kDa linear IgA bullous dermatosis antigen is not expressed in a patient with generalized atrophic benign epidermolysis bullosa with a novel homozygous G258X mutation in COL17A1. J Invest Dermatol 1998; 111:887-92. [PMID: 9804354 DOI: 10.1046/j.1523-1747.1998.00363.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The nature and expression pattern of the 97 kDa linear IgA bullous dermatosis antigen (LAD-1) and its role in epidermolysis bullosa have not been fully elucidated. In this study, we examined the expression of LAD-1 in the skin specimens of 70 patients with the various subtypes of epidermolysis bullosa, including simplex (n = 23), junctional (n = 15), and dystrophic variants (n = 32). For immunolabeling, we used two recently developed monoclonal antibodies to LAD-1 whose epitopes were ultrastructurally localized in the lamina lucida between NC16A and carboxyterminal domains of BPAG2, as well as autoantibodies against LAD-1 from the sera of two patients with linear IgA dermatosis. Among the 70 patients, only one patient with generalized atrophic benign epidermolysis bullosa failed to demonstrate LAD-1 expression. Although other major basement membrane components, including laminin 5, BPAG1, plectin, alpha6 and beta4 integrins, as well as type IV and type VII collagens were normally expressed, BPAG2/type XVII collagen was absent from the skin of this patient. Mutation analysis on COL17A1 using polymerase chain reaction amplification, heteroduplex scanning, and direct nucleotide sequencing revealed that this patient was homozygous for a novel nonsense mutation G258X in exon 11, and her parents were heterozygous carriers for this mutation. This is the first mutation located in the intracellular domain of BPAG2, and resides 817 bp upstream from the N-terminal amino acid sequence of LAD-1. These findings indicate that the absent expression of LAD-1 is observed in a BPAG2-deficient generalized atrophic benign epidermolysis bullosa patient with mutations in both alleles of COL17A1, and not in other epidermolysis bullosa subtypes. These findings also support the notion that LAD-1 is a degradation product of BPAG2.
Collapse
|
73
|
Longstreth J, de Gruijl FR, Kripke ML, Abseck S, Arnold F, Slaper HI, Velders G, Takizawa Y, van der Leun JC. Health risks. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1998; 46:20-39. [PMID: 9894351 DOI: 10.1016/s1011-1344(98)00183-3] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The health risks associated with ozone depletion will principally be those due to increased ultraviolet B (UV-B) radiation in the environment, i.e., increased damage to the eyes, the immune system, and the skin. Some new risks may also be introduced with the increased use of alternatives to the ozone-depleting substances (ODSs). Quantitative risk estimates are available for some of the UV-B-associated effects, e.g., cataract and skin cancer; however, the data are insufficient to develop similar estimates for effects such as immunosuppression and the toxicity of alternatives. Ocular damage from UV exposures includes effects on the cornea, lens, iris, and associated epithelial and conjunctival tissues. The most common acute ocular effect of environmental ultraviolet radiation (UVR) is photokeratitis. Also known as snowblindness in skiers, this condition also occurs in other outdoor recreationists. Chronic eye conditions likely to increase with ozone depletion include cataract, squamous cell carcinoma, ocular melanoma, and a variety of corneal/conjunctival effects, e.g., pterygium and pinguecula. Suppression of local (at the site of UV exposure) and systemic (at a distant, unexposed site) immune responses to a variety of antigens has been demonstrated in both humans and animals exposed to UV-B. In experiments with animals these effects have been shown to worsen the course/outcome of some infectious diseases and cancers. There is reasonably good evidence that such immunosuppression plays a role in human carcinogenesis; however, the implications of such immunosuppression for human infectious diseases are still unknown. In light-skinned populations, exposure to solar UVR appears to be the most important environmental risk factor for basal and squamous cell carcinomas and cutaneous melanoma. Originally it was believed that total accumulated exposure to UVR was the most important environmental factor in determining risk for these tumors. Recent information now suggests that only squamous cell carcinoma risk is related to total exposure. In the cases of both basal cell carcinoma and melanoma, new information suggests that increases in risk are tied to early exposures (before about age 15), particularly those leading to severe sunburns. Testing of a number of the chlorofluorocarbon (CFC) alternatives indicates that most of these chemicals have low acute toxicity, and low to moderate chronic toxicity. Some chemicals that were originally proposed as alternatives have been dropped from consideration because these tests raised concerns about toxicity and/or manufacturing difficulties. In one instance, high accidental occupational exposure was associated with liver damage, underlining the need for care in the use of these substitutes. Recent quantitative risk estimates have been developed for cataract, melanoma, and all skin cancers combined. These estimates indicate that under the Montreal Adjustments, cataract and skin-cancer incidence will peak mid-century at additional incidences of just under 3 per 100,000 and about 7 per 100,000, respectively.
Collapse
|
74
|
Ono K, Takizawa Y, Komai K, Takamori M. [Serial MRI study on a case of anterior spinal artery syndrome]. Rinsho Shinkeigaku 1998; 38:806-10. [PMID: 10078031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
A 63-year-old woman suddenly began to suffer from left chest pain. She gradually became unable to walk and was admitted to the emergency room at another hospital. When she became paraplegic in spite of steroid therapy, she was admitted to our hospital. Her affliction was diagnosed as anterior spinal artery syndrome because of flaccid paraplegia and dissociated sensory loss below the Th4 dermatome. Hematological study indicated a compensated DIC and hepatic enzyme abnormality, while the CSF examinations showed an elevation of protein and positive myelin basic protein (MBP) elevation. The initial MRI taken in the acute stage showed no abnormal signals on T1-weighted (T1) and Gd-enhanced images. The sagittal T2-weighted image (T2) revealed central high intensity (HI) with longitudinal extension from Th2 through the Th11 vertebral level. On axial T2, HI was located on the gray matter at the Th3 and Th4 vertebral level, the ventral two-thirds at the Th8 vertebral level, the central ventral side at the Th9 and Th10 vertebral level, and the entire cross section at the Th12 and L1. A follow-up MRI examination showed that the range of HI on the sagittal T2 had been reduced to 5 segments from Th6 through Th10 vertebral level. The T2 HI lesion on the axial aspect had become reduced so as to localize on the left ventral side at the Th8 vertebral level and on the central ventral side at Th9 and Th10.
Collapse
|
75
|
Hisamatsu S, Katsumata T, Takizawa Y. Tritium concentrations in pine needle, litter and soil samples. JOURNAL OF RADIATION RESEARCH 1998; 39:129-136. [PMID: 9735601 DOI: 10.1269/jrr.39.129] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Samples of pine needle, litter and soil samples collected in/around Akita City and Rokkasho Village in 1989 were analyzed for both free water 3H (FWT) and organically-bound 3H (OBT). The FWT concentrations decrease in the order, litter or soil > pine needle. FWT concentrations in soil depend on the moisture content, and tend to increase with decreasing soil moisture content. This relationship is consistent with the observation that FWT in the soil increases with oxidation of atmospheric tritiated hydrogen gas (HT) and decreases with rainwater dilution. The OBT concentrations increase in the order pine needle < litter < soil at most of the sampling locations. This suggests that historically high soil 3H concentrations may be reflected as high OBT concentrations in soils of the present.
Collapse
|
76
|
Ono K, Takizawa Y, Komai K, Nitta E, Takamori M. [Diagnostic muscle MRI abnormality in a patient with inclusion body myositis]. Rinsho Shinkeigaku 1998; 38:468-70. [PMID: 9805998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A 64-year-old woman was admitted to our hospital because of muscle weakness and atrophy in the extremities. Four years before admission, he was noticed to have elevated creatine kinase (CK) level, but had no further evaluation. Two years later, she became difficult in standing up and needed a wheelchair. Six months before admission, she noticed muscle wasting in the buttock, thigh, bilateral forearms, and weakness in the upper limbs. On neurologic examination, she had weakness in sternocleidomastoid and all limb muscles, predominantly in the distal portion of the upper extremities. Laboratory study revealed elevated CK, LDH, and aldolase levels, and myogenic change with fibrillation on needle EMG. Muscle biopsy showed myopathic changes with infiltration of mononuclear cells and rimmed vacuoles. The clinical manifestations as well as poor response to corticosteroids therapy were supportive of the diagnosis of inclusion body myositis. However, the distribution of muscle weakness in her wrist, weaker in the extensors than in the flexors, was not characteristic to IBM. This problem was solved by the right forearm MRI which showed a high signal intensity area in flexor muscles, but not in extensors on T1 and T2 weighted images. Accordingly, the muscle MRI of forearm was a diagnostic aid of IBM in this patient.
Collapse
|
77
|
Akagi H, Grandjean P, Takizawa Y, Weihe P. Methylmercury dose estimation from umbilical cord concentrations in patients with Minamata disease. ENVIRONMENTAL RESEARCH 1998; 77:98-103. [PMID: 9600802 DOI: 10.1006/enrs.1997.3822] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The methylmercury exposure of patients with congenital or infantile Minamata disease is known only from a small number of analyses of umbilical cords. Four laboratories in Japan have analyzed a total of 176 samples of umbilical cord tissue obtained from Minamata. The highest concentrations were seen in cord tissue from children born during 1950-1965, i.e., the peak period of acetaldehyde production in Minamata before installation of waste water treatment. Twenty-four samples from patients diagnosed with Minamata disease showed a median mercury concentration of 1.63 microg/g and differed significantly from levels seen in cord tissue from control children. However, children diagnosed with mental retardation had mercury concentrations in cord that were intermediate between the two other groups. Using regression coefficients obtained at a study conducted at the Faroe Islands, the median cord mercury concentration from the children with Minamata disease is estimated to correspond to about 216 microg/L cord blood and 41 microg/g in maternal hair. Based on correlations reported in the literature, the median daily mercury intake of the women whose children developed Minamata disease can then be estimated at about 225 microg. Although these children had fully developed Minamata disease, the estimates of median mercury levels are only four to five times higher than current mercury exposure limits.
Collapse
|
78
|
Takizawa Y, Pulkkinen L, Shimizu H, Lin L, Hagiwara S, Nishikawa T, Uitto J. Maternal uniparental meroisodisomy in the LAMB3 region of chromosome 1 results in lethal junctional epidermolysis bullosa. J Invest Dermatol 1998; 110:828-31. [PMID: 9579554 DOI: 10.1046/j.1523-1747.1998.00186.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Herlitz junctional epidermolysis bullosa (OMIM#226700) is a lethal, autosomal recessive blistering disorder caused by mutations in one of the three genes LAMA3, LAMB3, or LAMC2, encoding the constitutive polypeptide subunits of laminin 5. In this study, we describe a patient homozygous for a novel nonsense mutation Q936X in exon 19 of LAMB3, which has been mapped to chromosome 1q32. The patient was born with extensive blistering and demonstrated negative immunofluorescence staining for laminin 5, and transmission electron microscopy revealed tissue separation within lamina lucida of the dermal-epidermal junction, diagnostic of Herlitz junctional epidermolysis bullosa. The mother of the proband was found to be a heterozygous carrier for this mutation, whereas the father demonstrated the wild-type LAMB3 allele only. Nonpaternity was excluded by 13 microsatellite markers in six different chromosomes. Genotype analysis using 28 microsatellite markers spanning chromosome 1 revealed that the patient had maternal primary heterodisomy, as well as meroisodisomy within two regions of chromosome 1, one on 1p and the other one on 1q, the latter region containing the maternal LAMB3 mutation. These results suggest that Herlitz junctional epidermolysis bullosa in this patient developed as a result of reduction to homozygosity of the maternal LAMB3 mutation on chromosome 1q32.
Collapse
|
79
|
Hisamatsu S, Amano H, Isogai K, Atarashi M, Zhu H, Takizawa Y. Organically-bound 3H concentration in rice around atomic energy facilities. HEALTH PHYSICS 1998; 74:448-450. [PMID: 9525418 DOI: 10.1097/00004032-199804000-00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Rice samples collected around atomic energy facilities in the Tokai area were analyzed for organically-bound 3H (OBT). Measurement results were compared with those for samples from control areas in Japan and the People's Republic of China. OBT concentrations of rice in the Tokai area were found to be 4 times higher than the control area as maximum. Although this relatively high 3H concentration shows the effect of 3H release from the facilities into the environment, the concentration level is comparable with those in the rice sample from a northern interior region of China. The OBT concentration of rice sample from the general environment in interior China was 4.5 times higher than the control area in Japan. The radiation dose from the increasing 3H level is negligible in comparison with that from natural radiation.
Collapse
|
80
|
Takizawa Y, Shimizu H, Pulkkinen L, Hiraoka Y, McGrath JA, Suzumori K, Aiso S, Uitto J, Nishikawa T. Novel mutations in the LAMB3 gene shared by two Japanese unrelated families with Herlitz junctional epidermolysis bullosa, and their application for prenatal testing. J Invest Dermatol 1998; 110:174-8. [PMID: 9457915 DOI: 10.1046/j.1523-1747.1998.00105.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The LAMB3 gene encoding the beta3 chain of laminin 5 is a candidate gene for mutations in the autosomal recessive blistering skin disorder, junctional epidermolysis bullosa. In this study, we performed genetic analyses in two unrelated Japanese families with Herlitz junctional epidermolysis bullosa and identified two novel nonsense mutations in the LAMB3 gene. One of them, Q166X (CAG --> TAG), was found in the maternal allele of family 1 and the paternal allele of family 2. Conversely, the other mutation, W610X (TGG --> TGA), was found in the paternal allele of family 1 and the maternal allele of family 2. Thus, probands of both families were compound heterozygotes for these nonsense mutations. Haplotype analyses with intragenic LAMB3 polymorphisms suggested that both mutations had arisen independently in these two families. Both mutations create a premature translation termination codon predicting truncated beta3 chains that lead to absent expression of laminin 5 in the epidermal basement membrane zone. Based on these results, DNA-based prenatal diagnosis was performed by chorionic villus sampling for subsequent pregnancies in both families. Both fetuses were found to be heterozygous carriers of the W610X mutation together with a normal LAMB3 allele, indicating that they were phenotypically unaffected. These findings expand the repertoire of LAMB3 mutations in junctional epidermolysis bullosa, and emphasize the notion that premature termination codons in both alleles of the laminin 5 genes result in Herlitz junctional epidermolysis bullosa.
Collapse
|
81
|
Hachiya N, Takizawa Y, Hisamatsu S, Abe T, Abe Y, Motohashi Y. Atmospheric mercury concentrations in the basin of the amazon, Brazil. Environ Health Prev Med 1998; 2:183-7. [PMID: 21432539 PMCID: PMC2723357 DOI: 10.1007/bf02931699] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/1997] [Accepted: 11/19/1997] [Indexed: 11/30/2022] Open
Abstract
A wide regional mercury pollution in Amazon, Brazil is closely associated with goldmining that has been carried out in the basin of tributaries of the Amazon since the eighteenth century. Possible involvement has been discussed on atmospheric circulation in distributing the volatile pollutant. We developed a portable air sampler for the collection of mercury compounds and determined atmospheric mercury concentrations at several sites in Brazil including the basin of the Amazon tributaries. The mean concentration of total mercury was between 9.1 and 14.0 ng/m(3) in the basin of the Uatumã River located in the tropical rain forest far from goldmining sites and from urbanized area. These mercury levels exceeded the background level previously reported in rural area and, furthermore, were higher than concentrations observed in Rio de Janeiro and in Manaus that were compatible with the reference values for urban area. Mercury concentrations were also determined in gold refineries in the basin of the Tapajos River, and detected at a significant but not a health deteriorating level. Although only preliminary data were available, the present observations were in favor of the hypothesis that mercury is distributed widely by long distant transport by the atmospheric circulation after released at gold mining sites.
Collapse
|
82
|
Takizawa Y, Qingmei H, Hisamatsu S, Abe T. Concentration of232Th,230Th and228Th in various tissues of Japanese subjects. J Radioanal Nucl Chem 1997. [DOI: 10.1007/bf02063645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
83
|
Hirasawa F, Kawarada Y, Sato M, Suzuki S, Terada K, Miura N, Fujii M, Kato K, Takizawa Y, Sugiyama T. The effect of silver administration on the biosynthesis and the molecular properties of rat ceruloplasmin. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1336:195-201. [PMID: 9305790 DOI: 10.1016/s0304-4165(97)00026-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To examine the cause of the altered ceruloplasmin (Cp) metabolism by silver administration, we analysed the properties of serum Cp by gel filtration chromatography, affinity chromatography and polyacrylamide gel electrophoresis. Metal contents in the Cp fraction from the silver-treated group were estimated as approximately 0.8 atom of silver and 4.2 atoms of copper per molecule, and as 5.9 atoms of copper for the control group. These findings confirm that holo-Cp from rat serum administered with silver nitrate exists as a silver-bound inactive form, suggesting that silver displaces one of Cp's copper atoms associating with oxidase activity. Matured holo-Cp also appeared in the Golgi in both groups, however, the amounts of enzymatically active holo-Cp showed a decrease after silver administration, while the apo-Cp level was hardly changed. These findings suggest that silver-bound holo-Cp is accomplished at Golgi.
Collapse
|
84
|
Satoh T, Takahashi K, Yahata K, Nakagawa S, Wojtczak A, Takizawa Y, Tajima N, Kohyama A, Akazawa S, Higashi T, Yamaguchi N, Sekikawa A. [Application of Internet technology in public health]. [NIHON KOSHU EISEI ZASSHI] JAPANESE JOURNAL OF PUBLIC HEALTH 1997; 44:518-22. [PMID: 9314706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Recent advances in telecommunication technology have been enormous. Application of this technology in public health has the potential to markedly improve global health through better surveillance and information systems. With this assumption the GHNet was established in 1994 by representatives from academia, WHO, Pan American Health Organization, the World Bank, NASA, IBM, and AT & T. The GHNet consists of seven components: 1) promotion of networking with the Internet among people in public health; 2) disease tele-monitoring; 3) distance learning system with the internet; 4) connection of non-governmental health organizations; 5) training cyberdocs who are educated in both public health and telecommunications; 6) establishment of an electronic scientific research server; and 7) a home page on the World Wide Web (WWW). In order to effectively incorporate the Internet into the field, connectivity and knowing how to use it are of critical concern. More and more facilities are connected to the Internet in Japan. However, few courses teaching how to utilize the Internet are provided for people in this field. An Internet training course for people in public health was held as joint venture of the World Health Organization (WHO) and the Global Health Network (GHNet) on October 31, 1996, at the 55th Annual Meeting of Japanese Society of Public Health. Most of the participants for the course were from local public health departments and very few had previous experience with the Internet before the course. During this course participants learned how to use e-mail, how to find health resources on the WWW, how to construct a home page, and how the Internet could be utilized to improve public health, with their computers actually hooked to the Internet. From this experience, we found that this kind of course is feasible and beneficial and hope that this course would serve as a model for training people in public health.
Collapse
|
85
|
Ohnishi H, Okada J, Yamaguchi M, Ogata H, Hatano K, Takizawa Y, Imai Y, Hara R, Araki T. [Effect of daily administration of oral etoposide for non-small cell lung cancer treated with concurrent radiation therapy]. NIHON IGAKU HOSHASEN GAKKAI ZASSHI. NIPPON ACTA RADIOLOGICA 1997; 57:510-4. [PMID: 9267140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to explore the effect of daily administration of oral etoposide (25 mg) for patients with non-small cell lung cancer treated with concurrent radiation therapy. Planned endpoints were response, survival and toxicity. Forty-one patients with non-small cell lung cancer were divided into 25 patients given daily oral etoposide (25 mg) with concurrent radiation therapy (ERT group) and 16 patients given radiation therapy alone (RT group). Etoposide was administrated in the morning throughout radiation therapy. The median total irradiated dose was 63.1 Gy in the ERT group and 64.0 Gy in the RT group. Twenty-four patients completed therapy in the ERT group and 16 in the RT group. Three (15%) ERT patients achieved complete response (CR) and 9 (45%) achieved partial response (PR). In the RT group, no patients achieved CR and 9 (69%) achieved PR. One-year survival was 22.6% with ERT and 23.0% with RT. The prognosis of stage III patients in the ERT group was worse than that in the RT group because radiation pneumonitis and radiation esophagitis were more severe with ERT. In conclusion, the ERT group had better local response but worse in survival than the RT group. Complications of ERT were severe enough to cause death in some patients. ERT had no clear advantage over RT.
Collapse
|
86
|
Takizawa Y, Shimizu H, Nishikawa T, Hatta N, Pulkkinen L, Uitto J. Novel ITGB4 mutations in a patient with junctional epidermolysis bullosa-pyloric atresia syndrome and altered basement membrane zone immunofluorescence for the alpha6beta4 integrin. J Invest Dermatol 1997; 108:943-6. [PMID: 9182827 DOI: 10.1111/1523-1747.ep12296240] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Immunofluorescence studies of junctional epidermolysis bullosa with pyloric atresia (JEB-PA) have suggested abnormalities in the expression of the alpha6 beta4 integrin, an integral component of hemidesmosomes. In this study, we examined a family with two affected individuals with JEB-PA for mutations in the ITGA6 and ITGB4 genes which encode the alpha6 and beta4 integrin polypeptides, respectively. Mutation detection strategy based on PCR amplification of genomic DNA, followed by heteroduplex analysis and direct nucleotide sequencing, did not reveal sequence variants in ITGA6. Putative pathogenic mutations, however, were identified in both ITGB4 alleles. Specifically, the proband was a compound heterozygote for a 1-bp maternal deletion, 3434delT, and an 8-bp paternal deletion, 4050de18. Both mutations result in a frameshift and premature termination codon downstream from the deletion. At the protein level, immunofluorescence of the skin of the proband revealed negative staining for the integrin alpha6 and markedly reduced staining for the beta4 subunit. Thus, the results support the notion of close association of the alpha6 beta4 integrin subunits and further attest to the critical role of this integrin in providing physiologic stability to the dermal-epidermal junction.
Collapse
MESH Headings
- Alleles
- Antibodies, Monoclonal/analysis
- Antibodies, Monoclonal/immunology
- Antigens, CD/analysis
- Antigens, CD/genetics
- Antigens, CD/immunology
- Antigens, Surface/analysis
- Antigens, Surface/genetics
- Antigens, Surface/immunology
- Base Sequence
- Basement Membrane/chemistry
- Basement Membrane/immunology
- Basement Membrane/ultrastructure
- DNA/analysis
- DNA/chemistry
- DNA/genetics
- Desmosomes/chemistry
- Desmosomes/ultrastructure
- Epidermolysis Bullosa, Junctional/genetics
- Epidermolysis Bullosa, Junctional/pathology
- Exons
- Female
- Gene Deletion
- Heterozygote
- Humans
- Immunohistochemistry
- Infant, Newborn
- Integrin alpha6
- Integrin alpha6beta4
- Integrin beta4
- Integrins/analysis
- Integrins/genetics
- Integrins/immunology
- Male
- Mutation
- Polymerase Chain Reaction
- Pylorus/abnormalities
- Skin/chemistry
- Skin/pathology
- Skin/ultrastructure
- Syndrome
Collapse
|
87
|
Takizawa Y, Saida T, Tokuda Y, Dohi S, Wang YL, Urano K, Hioki K, Ueyama Y. New immunodeficient (nude-scid, beige-scid) mice as excellent recipients of human skin grafts containing intraepidermal neoplasms. Arch Dermatol Res 1997; 289:213-8. [PMID: 9143737 DOI: 10.1007/s004030050182] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Engraftment of normal or lesional human skin onto nude or SCID (severe combined immunodeficiency) mice has been used as an in vivo experimental model. However, this model has some limitations, such as shrinkage and loss of the grafted skin over time. To improve the experimental model, we have produced two new SCID-lineage mouse strains, BALB/cA-nude-scid (nu/nu, scid/scid) and BALB/cA-beige-scid (bg/bg, scid/scid) mice, by the method of cross intercross. Intraepidermal neoplastic lesions such as Bowen's disease were grafted onto the back of the mice of these strains. The rate of reduction in the size of the grafts was lower on nude-scid and beige-scid mice than on SCID mice. Rates of survival of neoplastic cells in the grafts were higher in nude-scid mice than in SCID and beige-scid mice (SCID mice 38%, nude-scid mice 55%, beige-scid mice 38%). Neoplastic cells of Bowen's disease grafted onto a beige-scid mouse proliferated and invaded the dermis during 233 days of observation, confirming the progression to invasive squamous cell carcinoma from carcinoma in situ. The present study revealed that nude-scid and beige-scide mice newly produced by us provide a very useful in vivo experimental model for the investigation of carcinogenesis and tumor progression in human skin.
Collapse
|
88
|
Shimizu H, Takizawa Y, McGrath JA, Pulkkinen L, Christiano AM, Uitto J, Burgeson RE, Iwatsuki K, Niimi N, Noguchi M, Imayama S, Abe Y, Shirakata Y, Hagiwara S, Saida T, Ogawa H, Hashimoto I, Nishikawa T. Absence of R42X and R635X mutations in the LAMB3 gene in 12 Japanese patients with junctional epidermolysis bullosa. Arch Dermatol Res 1997; 289:174-6. [PMID: 9128767 DOI: 10.1007/s004030050175] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
89
|
Kimura M, Tomizawa I, Takizawa Y, Ohtomo H. [A study of relapsed cases of vivax malaria after the standard primaquine therapy]. KANSENSHOGAKU ZASSHI. THE JOURNAL OF THE JAPANESE ASSOCIATION FOR INFECTIOUS DISEASES 1996; 70:1086-91. [PMID: 8952270 DOI: 10.11150/kansenshogakuzasshi1970.70.1086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Vivax malaria is the most frequent among imported malaria in Japan, comprising about 60% of the total cases. Usually, after the acute phase therapy, e.g. with chloroquine, patients with vivax malaria are treated with the standard course of primaquine, i.e. 15 mg base/day for 14 days, as curative therapy. Recently, however, cases of relapse of vivax malaria after this standard primaquine therapy were reported from various countries and were also encountered in Japan. This report showed that the relapse after the standard primaquine therapy occurred most frequently in the cases acquired in Papua New Guinea, followed by Indonesia and Thailand. In contrast, the relapse rate of the cases acquired in India was low. Most of the relapsed cases were successfully treated with either of the regimens 1) 30 mg/ day for 7 days, 2) 2 courses of the standard primaquine therapy given 1 month apart or 3) 15 mg/ day for 21 days, without noticeable side effects. It is imperative to establish the most appropriate regimen with primaquine for the curative treatment of vivax malaria contracted in the areas mentioned above.
Collapse
|
90
|
Tomizawa I, Takizawa Y, Nitta Y, Tsunoda T, Fukuda H, Yamaguchi T, Masuda G, Negishi M, Ajisawa A, Murata M, Ohnishi K, Irimajiri S, Obana M, Sajima Y, Sagara H, Kato H, Hosoda S, Banba T, Sasaki M, Yoshikawa K, Nakagawa M, Ohkubo H, Kim Y, Akao M, Fukuyama M. [Clinical study of prulifloxacin on infectious enteritis. Japan Research Committee of Prulifloxacin, Research Group on Infectious Enteritis]. KANSENSHOGAKU ZASSHI. THE JOURNAL OF THE JAPANESE ASSOCIATION FOR INFECTIOUS DISEASES 1996; 70:727-45. [PMID: 8797308 DOI: 10.11150/kansenshogakuzasshi1970.70.727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Prulifloxacin (PUFX), a new quinolone antimicrobial agent, was administered to a total of 122 patients and carriers to investigate its clinical efficacy, safety and usefulness in infectious enteritis (bacillary dysentery, enteritis caused by Salmonella spp. and enteropathogenic E. coli, cholera and so on). In addition, the minimum inhibitory concentration (MIC) of UFX (active compound) was determined against each clinical isolate, and compared with that of ciprofloxacin (CPFX), ofloxacin (OFLX), tosufloxacin (TFLX) and nalidixic acid (NA). The correlation between the concentration of UFX in feces and the change of the fecal microflora were also investigated when PUFX was administered to the patients with acute infectious enteritis. A daily dose of 400 mg of PUFX was administered orally in two divided doses (morning and evening) for 5 days, with the exception of 7 days administration against salmonella enteritis and 3 days administration against cholera. 84 cases were adapted for evaluating the usefulness. The clinical efficacy was 100% in all the enteritis except salmonella enteritis, in which it was 88.9% (8/9 cases). On the bacteriological efficacy, the elimination rate was 100% in all isolates except Salmonella spp., in which it was 75.0% (12/16 cases). As for the adverse effect, uriticaria in moderate degree was observed in 1 (0.9%) of 109 cases. Abnormal changes in laboratory findings were seen in 3 (3.0%) of 100 cases, consisting of 1 with eosinophilia and 2 with elevated S-GPT, although they were all slight in degree. The usefulness rate was 65.5% (55/84 cases) for "very useful" and 95.2% (80/84 cases) for "very useful" and "useful". MIC90 of UFX against Shigella spp., Salmonella spp., E. coli and V. cholerae, was 0.025, 0.05, 0.025 and 0.05 microgram/ml, respectively. These values were the same as those of CPFX and TFLX, and superior to OFLX and NA. UFX concentrations in feces followed by administration of PUFX in 3 cases with acute infectious enteritis were higher than that of MIC90 of UFX against Shigella spp., Salmonella spp., E. coli and V. cholerae. The changes of the fecal microflora, which influence the efficacy and safety of PUFX, were not observed.
Collapse
|
91
|
Abstract
Lens luxation was found in a male CD-1 (ICR) mouse. Ophthalmologic examinations revealed conical cornea anterior synechia and corneal neovascularization in the right eye. The lens was dislocated heterocentrically within the posterior chamber. Histologically, anterior lens luxation and adhesion between the iris and cornea were observed.
Collapse
|
92
|
Kurihara Y, Shimizu H, Ishiko A, Masunaga T, Sato M, Takizawa Y, Nishikawa T, Fujiwara T, Aiso S. 003 Reexamination of ultrastructure of human epidermis using liquid helium cryofixation system. J Dermatol Sci 1996. [DOI: 10.1016/0923-1811(96)89404-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
93
|
Takizawa Y, Shimizu H, Kato S, Matsunaga J, Tomita Y, Nishikawa T. 139 Oculocutaneous albinism: Correlation of the genotype and phenotype. J Dermatol Sci 1996. [DOI: 10.1016/0923-1811(96)89543-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
94
|
Asaka T, Takizawa Y, Kariya T, Nitta E, Yasuda T, Fujita M, Sawasaki S, Naiki Y, Nakatani N, Doushita T, Miura T, Ueda F, Takamori M, Matsushima A. Tuberculous tenosynovitis in the elbow joint. Intern Med 1996; 35:162-5. [PMID: 8680108 DOI: 10.2169/internalmedicine.35.162] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A 74-year-old woman was noted to have a mass lesion near the right elbow joint during medication for pulmonary tuberculosis. After discontinuation of medication, the mass gradually became enlarged with swelling and tenderness of the joint. Radiological evaluation disclosed tenosynovitis with an encapsulated abscess. Microscopic examination and culture of an aspiration biopsy specimen from the abscess showed no microorganisms. However, DNA extracted from the specimen contained mycobacterium tuberculosis DNA, permitting a diagnosis of tuberculous tenosynovitis. Mycobacterium is not always detected in biopsy specimens of tuberculous arthritis and tenosynovitis. In such cases, genetic diagnosis may be of great use.
Collapse
|
95
|
Sagara H, Yoshikawa K, Tomizawa I, Takizawa Y, Nitta Y, Tsunoda T, Fukuda H, Yamaguchi T, Masuda G, Negishi M, Ajisawa A, Murata M, Ohnishi K, Irimajiri S, Obana M, Matsumoto F, Imai T, Sakurai I, Takahashi T, Mori M, Mizuno Y, Katoh K, Hosoda S, Bamba T, Saito M. [Basic and clinical studies of pazufloxacin on infectious enteritis research group of T-3761 on infectious enteritis]. KANSENSHOGAKU ZASSHI. THE JOURNAL OF THE JAPANESE ASSOCIATION FOR INFECTIOUS DISEASES 1996; 70:60-72. [PMID: 8822054 DOI: 10.11150/kansenshogakuzasshi1970.70.60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A clinical study was carried out on pazufloxacin (PZFX) in 137 patients including shigellosis, Salmonella enteritis, enteropathogenic Esherichia coli enteritis and cholera, and carriers of these pathogens. Antibacterial activity of PZFX against clinical isolates, fecal concentration of PZFX and effects of PZFX on fecal microflora were also investigated. The overall clinical efficacy rate was 97.2%. The bacteriological efficacy rates were 98.2% against Shigella spp., 81.8% against Salmonella spp., 50% against Vibrio cholerae O1, and 100% against E. coli, V. parahaemolyticus, Aeronomas spp., Plesionomas shigelloides and V. cholerae non-O1, respectively. Side effect (epigastralgia) was observed in 1 of 130 cases (0.8%). The rate of abnormal laboratory findings was 11.2% (11/98). These were mainly elevation of GOT and/or GPT and increased eosinophils. The clinical usefulness rate was 95.2%. The MIC90 values of PZFX against Shigella spp., Salmonella spp. and E. coli were 0.025, 0.025 and 0.025 micrograms/ml, respectively. The results of fecal drug concentration and the effects on fecal microflora in one patient were compatible with those obtained in healthy volunteers.
Collapse
|
96
|
Sueyama H, Nakano M, Sakumoto K, Toita T, Takizawa Y, Moromizato H, Kakihana Y, Kushi A, Moromizato H, Higashi M. Intra-arterial chemotherapy with cisplatin followed by radical radiotherapy for locally advanced cervical cancer. Gynecol Oncol 1995; 59:327-32. [PMID: 8522249 DOI: 10.1006/gyno.1995.9968] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Locally advanced cervical cancer has a dismal prognosis, with a high local failure rate and a poor survival rate. To improve the cure rate for advanced carcinoma of the cervix, we initiated a study of intra-arterial (I-A) chemotherapy with cisplatin via the uterine artery prior to definitive radiotherapy. I-A chemotherapy via the internal iliac artery has been used to treat advanced cervical cancer; however, access by way of the uterine artery has not been tested for this purpose. Thirty-four patients with central tumor > or = 5 cm in anteroposterior diameter observed on CT scans were treated with I-A chemotherapy. I-A chemotherapy consisted of unilateral catheterization of the uterine artery using 120 mg/m2 cisplatin. After assessment of I-A chemotherapy, all but 3 patients were treated with a combination of whole-pelvis external irradiation and intracavitary irradiation. The 3 patients underwent external radiotherapy alone. Twenty-seven of 34 patients treated were evaluable for response to I-A chemotherapy. Eleven patients (41%) experienced a partial response. Seventy-six percent of the 34 patients treated with I-A chemotherapy followed by radiotherapy exhibited a complete response by the end of treatment. Toxicity was well tolerated and no death due to treatment occurred. The 2- and 5-year actuarial survival rates were 64 and 55%, respectively. The crude incidences of pelvic recurrence and distant metastasis observed at a median follow-up of 54 months were both 47%. This study for locally advanced cervical cancer suggests there is benefit to be derived from our I-A chemotherapy followed by radical radiotherapy.
Collapse
|
97
|
|
98
|
Tanabe H, Takizawa Y, Takeuchi N. Development of a portableα-particle counter for public acceptance activities. J Radioanal Nucl Chem 1995. [DOI: 10.1007/bf02040221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
99
|
Obana M, Irimajiri S, Tomizawa I, Takizawa Y, Sakamoto Y, Nitta Y, Tsunoda T, Fukuda H, Yamaguchi T, Masuda G. [clinical study of balofloxacin on infectious enteritis and assessment of the fecal drug concentration and intestinal microbial flora in patients with inpatients with infectious enteritis. Research group of balofloxacin on infectious enteritis]. KANSENSHOGAKU ZASSHI. THE JOURNAL OF THE JAPANESE ASSOCIATION FOR INFECTIOUS DISEASES 1995; 69:991-1006. [PMID: 7594801 DOI: 10.11150/kansenshogakuzasshi1970.69.991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The efficacy, safety and usefulness of balofloxacin (BLFX) for patients with acute infectious enteritis and the carriers mainly shigellosis, were investigated. The drug was administered at a daily dose of 200 mg twice a day for 3 days to patients with cholera, 7 days to patients with Salmonella enteritis and 5 days to patients with other conditions of infectious enteritis including shigellosis; 1. The efficacy was analyzed in 89 of the 135 patients who received the administration (43 patients with shigellosis, 14 with Salmonella enteritis, 8 with enteropathogenic/ enterotoxigenic Escherichia coli enteritis, 3 with cholera, 7 with enteritis with other pathogenic bacteria, 6 with polymicrobial infectious enteritis and 8 with acute enteritis that was pathogen-negative). 2. In patients bearing symptoms and who thus could be analyzed for drug efficacy, the drug was markedly effective or effective 50/52 (96.2%). 3. Bacteriologically, the drug was effective for Shigella spp. in 41 (100%) of 41, Salmonella spp. in 12 (85.7%) of 14, and enteropathogenic/enterotoxigenic Escherichia coli in 8 of 8 cases. 4. Adverse effects were seen in 5/133 patients (3.8%) receiving the drug, including two cases of skin eruption, one of the numbness of the hands, one of oral aphtha, and one of nausea. In patients for whom laboratory findings were available, 20/115 (17.4%) showed abnormalities, mainly elevations of GOT and/or GPT, but these were slight. 5. In terms of subjective reports of usefulness, 51/82 (62.2%) were markedly satisfied, and 73/82 (89.0%) were either satisfied or markedly satisfied. 6. The influence of administration of BLFX on fecal concentration and intestinal microbial flora was investigated in 2 patients with acute infectious enteritis. Results approximately equivalent to such flora levels in healthy subjects were obtained. These results suggest that BLFX is highly useful for infectious enteritis such as that caused by shigellosis.
Collapse
|
100
|
Takizawa Y, Takahashi K. [Three-dimensional finite element analysis of blowout fractures]. NIPPON GANKA GAKKAI ZASSHI 1995; 99:972-9. [PMID: 7676900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
There are a number of theories as to how orbital fractures come about, but there are still a lot of unanswered questions regarding the dynamic characteristics of the orbit at the time of the fracture. To answer these questions, we analyzed the degree and concentration of stress within the orbit depending on the loads placed upon it. We used a computer to create a three-dimensional finite element model which could simulate the orbital fracture process. We found that direct force applied against the inferior orbital rim by forces outside the eye results in increased stress within the lower wall of the orbit, and that stress tends to concentrate in the thin nasal side of the orbital groove as pressure within the orbit mounts. When we compared these findings with clinical cases of orbital fracture, it became clear that the best way to explain the clinical data is by reference to the combined effect of direct force applied against the inferior orbital rim by elements outside the eye and the buildup of internal pressure within the orbit.
Collapse
|