Association of natural tooth loss with genetic variation at the human matrix Gla protein locus in elderly women

Natural tooth loss represents a major medical issue within the elderly population, since it impairs masticatory function critical for oral intake of essential nutrition. Contribution of genetic factors has been implicated in the determination of natural tooth loss; degree of reduction in number of natural teeth remaining intact (NTI) varies among individuals; thus, heterogeneity in NTI might reflect genetic variation within the population. One candidate gene, the matrix Gla protein gene (MGP), has been implicated in the pathogenesis of bone loss through a repression of bone/tooth formation. We have investigated a possible association between the CA repeat polymorphism at the human MGP gene locus and the NTI in 458 elderly Japanese women. In 916 chromosomes tested, ten alleles of the polymorphic nucleotide repeat were observed (designated A1–A10), among which five alleles were regarded as major alleles to be tested for the association. Twenty-seven women who possessed an A6 allele (164 bp) had significantly higher NTI than the remaining participants (n=431), who did not carry an allele of that size (mean: 10.0 teeth vs 5.6 teeth; P=0.007, Mann-Whitney test). An eight-year longitudinal follow-up study of NTI suggested that the genetic variations at the MGP locus did not affect the rate of tooth loss in the elderly period. These results suggest that genetic variation at the MGP gene locus is associated with some determinants for tooth loss in elderly women.     

Primary rhabdomyosarcoma of the iliac bone in an adult: A case mimicking fibrosarcoma

Primary rhabdomyosarcoma of bone is exceedingly rare. We present a case of rhabdomyosarcoma of the iliac bone in a 32-year-old male. Histologically, the tumour consisted mainly of a uniform proliferation of elongated spindle cells arranged in a herring bone pattern, simulating fibrosarcoma. Focally there was a conventional embryonal pattern with scattered rhabdomyoblasts possessing an eosinophilic cytoplasm. Immunohistochemical studies disclosed expression of muscle markers such as desmin and muscle-specific actin, in both the embryonal and spindle-cell areas and myoglobin only in the embryonal areas. Such histological features are unusual for classical embryonal rhabdomyosarcoma. The anatomical site and age of the patient are also atypical.     

Establishment and characterization of αs1-casein–specific T-cell lines from patients allergic to cow’s milk: Unexpected higher frequency of CD8 T-cell lines

To study cow’s milk allergy at the cellular level, we assessed the reactivity of peripheral blood mononuclear cells from patients allergic to cow’s milk to α_s1-casein, which is one of the major allergens in cow’s milk. Proliferation of the cells to α_s1-casein activation showed a rather weak response. Therefore to understand T-cell reactivity to α_s1-casein in more detail, we prepared α_s1-casein–specific T-cell lines from patients allergic to cow’s milk and established 26 T-cell lines. These T-cell lines could be classified into three groups by analyzing their surface marker expression: those containing predominantly CD4⁺CD8^- T cells, those containing both CD4⁺CD8^- and CD4^-CD8⁺ T cells, and those containing predominantly CD4^-CD8⁺ T cells. The CD8⁺ T cells were obtained at an unexpectedly higher frequency from the patients. These T-cell lines produced interferon-γ and IL-4. These results suggest that CD8⁺ T cells specific for α_s1-casein and CD4⁺ T cells were primed by the stimulation with α_s1-casein in patients allergic to milk and that both T cells may play a key role in the onset, progression of, or recovery from cow’s milk allergy. (J ALLERGY CLIN IMMUNOL 1996;97:1342-9.)     

The value of external morphology in the identification of larval anisakid nematodes: a scanning electron microscope study

We studied larval nematodes of four genera of the Anisakidae using a scanning electron microscope (SEM). The anterior and posterior extremities and cuticular structures of the 3rd-stage larvae (L3) ofAnisakis type I,Pseudoterranova decipiens, Contracaecum type B andHysterothylacium were examined. The 4th-stage larvae (L4) ofAnisakis type I,P. decipiens, recovered after infection into laboratory rats, and the L3 and L4 ofAnisakis type I larvae from human were also examined in the same way. There were generic differences in the shape and size of the lip bulges, external papillary structures, the appearance of the boring tooth, the width and depth of the grooves and ridges of the cuticle and the caudal structures of the L3. InAnisakis type I andP. decipiens L3, changes were seen in the anterior extremity, cuticle and posterior extremity after molting to the L4. Similar changes can be expected in larvae infecting man. The L4 ofAnisakis type I from rat and man were similar, while the L4 ofAnisakis type I andP. decipiens showed differences. These ultrastructural differences might be of value in the identification of fragments recovered during endoscopy in man.     

Detection of single nucleotide substitution by competitive allele-specific short oligonucleotide hybridization (CASSOH) with immunochromatographic strip

Recent advances in human genome research have revealed that genetic polymorphisms, such as single nucleotide polymorphisms (SNPs), are closely associated with susceptibility to various common diseases and adverse drug reactions. Also, numerous mutations responsible for a number of genetic diseases have been identified. Clinical application of genetic information to individual health care requires simple and rapid identification of nucleotide changes in clinical settings. We have devised a novel low-tech method for the detection of a single nucleotide substitution using competitive allele-specific short oligonucleotide hybridization with immunochromatographic strip. The gene of interest is PCR-amplified, hybridized to an allele-specific short oligonucleotide probe in the presence of a competitive oligonucleotide, and subjected to chromatography using a DNA test strip at room temperature. The genotype is unambiguously determined by the presence or the absence of visible purple lines on a strip. Feasibility of the method was demonstrated by the detection of a prevalent disease-causing mutations in glycogen storage disease type Ia (G6PC), medium-chain acyl-CoA dehydrogenase deficiency (ACADM), non-ketotic hyperglycinemia (GLDC), and clinically important polymorphisms in the CYP2C19 gene and the aldehyde dehydrogenase 2 gene (ALDH2). The procedure does not demand either technical expertise or expensive instruments and is readily performed in local clinical laboratories. The result is obtained within 10 min after PCR. This rapid and simple method of SNP detection may be used for point-of-care genetic diagnosis with potentially diverse clinical applications. Hum Mutat 22:166-172, 2003.     

Setting reference intervals without considering sex and age differences

We compared two sets of sex and age-specific reference intervals obtained from two large reference populations, one set calculated with data from 700,000 reference individuals by the nonlinear optimizing method of Ohgushi and Shibata and the other set calculated with data from 150,000 reference individuals from Shizuoka prefecture by the revised Hoffmann fitting method. Ten laboratory analytes used for health screening were compared. The sex- and age-specific reference intervals for total cholesterol, fasting blood sugar, uric acid, total protein, and albumin from the two large reference sample groups closely resembled each other, but reference intervals for the enzyme analytes aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and gamma-glutamyl transpeptidase only partly corresponded. Surprisingly, new information came from comparison of the sex- and age-specific reference intervals of alkaline phosphatase: low activities were observed in young females and higher activities were observed in older females. If a reference interval is used that does not take this observation into account, misdiagnosis of hyperthyroidism, which is frequently observed in young women, may result. Sex- and age-specific reference intervals should be used to interpret results of laboratory screening tests.     

Comparative chromosome mapping of sex-linked genes and identification of sex chromosomal rearrangements in the Japanese wrinkled frog (Rana rugosa, Ranidae) with ZW and XY sex chromosome systems

There are regional variations of sex chromosome morphologies in the Japanese wrinkled frog, Rana rugosa (2n = 26): heterogametic ZZ/ZW-type and XX/XY-type sex chromosomes, and two different types of homomorphic sex chromosomes. To search for homology between the ZW and XY sex chromosomes and the chromosome rearrangements that have occurred during sex chromosomal differentiation in R. rugosa, we performed chromosome mapping of sexual differentiation genes for R. rugosa by FISH. Three genes, AR, SF-1/Ad4BP and Sox3, were localized to both the ZW and XY chromosomes, and their locations were all different between the Z and W and between the X and Y. AR and SF-1/Ad4BP were located on the short arms of the W and X and the long arms of Z and Y, and Sox3 was mapped to the different locations on the long arms between the Z and W and between the X and Y, probably as a result of multiple rearrangements that occurred during the process of sex chromosome differentiation. However, the chromosomal locations of three genes were almost consistent between the Z and Y and between the W and X, indicating that the Z and Y chromosomes and the W and X chromosomes were respectively derived from the same origins. Dmrt1, which is located on avian sex chromosomes, was localized to autosomes in R. rugosa with both the ZW and XY sex chromosomes, suggesting that Dmrt1 might not be related to sex determination in this species.     

Significant association between nonsyndromic oral clefts and arylhydrocarbon receptor nuclear translocator (ARNT)

The etiology of nonsyndromic oral clefts (cleft lip, cleft palate, or cleft lip and palate) is still controversial, but is considered to involve both genetic and environmental factors. One of suspected environmental factors is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) found in tobacco, herbicides, contaminated soil, and food. TCDD administered during organogenesis in mice causes a high incidence of CP in fetuses. There is ample evidence that aryl hydrocarbon receptor (AHR), AHR nuclear translocator (ARNT), and cytochrome P450 1A1 (CYP1A1) are involved in TCDD metabolism. We assessed whether there is any association in the Japanese population of nonsyndromic oral clefts with single nucleotide polymorphisms (SNPs) in the AHR, ARNT, and CYP1A1 genes using transmission disequilibrium test (TDT) and case-control study. We identified and investigated three SNPs in ARNT; 567G/C (V189V), IVS12-19T/G, and 2117C/T (P706L). Two amino acid substitutions, R554L in AHR and I462V in CYP1A1, were also investigated. In the TDT, the C allele of ARNT 567G/C was preferentially transmitted to patients (P = 0.033). When a haplotype consisting of 567G/C and IVS12-19T/G in ARNT was considered, the preferential transmission of the CT (567C-IVS12-19T) haplotype was observed (P = 0.0012). In a case-control study, a significant association of IVS12-19T/G in ARNT was observed (P = 0.021). The SNPs studied in AHR and CYP1A1 were not associated with the disease. Our results suggest that ARNT is involved in the development of nonsyndromic oral clefts in the Japanese population.