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K Hori

Publications and source records attributed to K Hori.

At least 19 recordsLinked to original sources
PubMed2025

Impact of Chewing Behavior Change on Cognition and Cerebral Hemodynamics.

BACKGROUND: Impaired chewing ability is a recognized risk factor for cognitive decline in older adults, potentially due to reduced neural stimulation in cognition-related brain regions. While short-term studies have demonstrated transient increases in neural activity from chewing, the sustained cognitive and neurophysiological effects of encouraging thorough chewing habits in daily life remain unclear. OBJECTIVE: This randomized controlled trial investigated whether promoting thorough chewing during meals could improve cognitive function and cerebral hemodynamics in older adults. METHODS: Fifty participants aged 65 y or older were randomly assigned to either a 1-mo intervention group, which used a wearable device to monitor and increase chewing strokes during meals, or a control group that maintained usual chewing habits. Chewing behavior, cognitive performance (including memory and executive function via the color Stroop test), and cerebral hemodynamics in the dorsolateral prefrontal cortex (DLPFC) were measured at baseline and after 1 mo. Statistical analyses included t tests, chi-square tests, 2-way analysis of variance with post hoc tests, Pearson correlations, and generalized linear models to evaluate group differences and associations between chewing and cognitive outcomes. RESULTS: Significant time-by-group interactions were observed for memory, F(1, 48) = 6.24, P = 0.043, and hemodynamic responses in the left DLPFC, F(1, 48) = 6.19, P = 0.013. The intervention group showed increased chewing frequency (P = 0.017), improved memory performance, and reduced left DLPFC responses compared with controls. Chewing frequency was positively correlated with Stroop test scores (r = 0.53, P = 0.010) and negatively with hemodynamic changes in the left DLPFC (r = -0.30, P = 0.040). Although improvements in other cognitive outcomes and hemodynamic measures favored the intervention group, these differences did not reach statistical significance. CONCLUSIONS: Promoting intentional chewing habits for 1 mo may enhance memory-related cognitive performance and neural efficiency in the DLPFC during working memory tasks in older adults. This nonpharmacologic, low-burden strategy warrants further research with longer interventions to support cognitive health and dementia prevention. TRIAL REGISTRATION ID: UMIN000044280Knowledge Transfer Statement:This study demonstrates that promoting thorough chewing habits in older adults can improve memory and enhance neural efficiency in the brain. Encouraging intentional mastication is a simple, nonpharmacologic approach that may help maintain cognitive health and prevent dementia, providing a practical strategy for clinicians and policymakers to support healthy aging.

Humans↗
PubMed2007

Influence of human jaw movement on cerebral blood flow.

Temporal changes in cerebral blood flow induced by jaw movement have yet to be investigated. To assess the influence of pattern and intensity of muscle contraction during jaw movement on task-induced change in cerebral blood flow, we performed bilateral transcranial Doppler ultrasound examination during clenching, gum chewing, and tooth tapping in healthy volunteers. A random-effects model analysis revealed a significant increase in middle cerebral artery blood flow velocity during clenching (high muscle activity) and gum chewing (moderate muscle activity), compared with the preceding rest period; however, such an increase was not detected during tooth tapping (low muscle activity). Cerebral blood flow was greater on the working side during the intensive isometric contraction of the masseter muscle in clenching. These results suggest that task-induced change in cerebral blood flow during jaw movement is influenced by the change in peripheral circulation evoked by muscle contraction.

Adult↗
PubMed2006

Coordination of tongue pressure and jaw movement in mastication.

The tongue plays an important role in mastication and swallowing by its contact with the hard palate. Using an experimental palatal plate with 7 pressure sensors, and recording jaw movement using mandibular kinesiography, we assessed, in healthy subjects, the coordination of tongue and jaw movements during the entire masticatory sequence of solids, by measuring tongue pressure against the hard palate. Tongue pressure appeared during the occlusal phase, reached a peak near the start of opening, and disappeared during opening. Specific patterns in order, duration, and magnitude of tongue pressure were seen at the 7 pressure sensors in each chewing stroke. Magnitude and duration were significantly larger in the late stage of chewing (8 strokes before initial swallowing) than in the early stage (until 8 strokes after starting mastication). The normal pattern of tongue contact against the hard palate, control of tongue activity, and coordination with jaw movement during mastication is described.

Adult↗
PubMed2005

QTL analysis of Fusarium head blight resistance using a high-density linkage map in barley.

Fusarium head blight (FHB) resistance was evaluated in a set of recombinant inbred (RI) lines from a cross between Russia 6 (resistant) and H.E.S. 4 (susceptible), which had one of the widest differences of FHB resistance reactions among ca. 5,000 barley germplasm accessions in Okayama University. Field-grown spikes were sampled and inoculated by the 'cut-spike test'. Resistance reactions on the parents and RI lines were scored by eleven grades, from resistant (0) to susceptible (10). Quantitative trait loci (QTL) analysis detected three QTL: two located on the long arm of chromosome 2H, and another on the short arm of chromosome 5H. A QTL located on chromosome 2H was coincident with the vrs1 locus, which governs inflorescence row type. The other QTL on chromosome 2H was positioned in the vicinity of cleistogamy locus (cly1 or Cly2) that determines inflorescence opening/closing. Resistant gene analog (RGA) and expressed sequence tag (EST) markers with homology for disease resistance genes were integrated into the high-density linkage map. Most of these markers were not localized near the identified resistance QTL, except for one RGA marker (FXLRRfor_XLRRrev170) localized in the vicinity of the cly1/Cly2 locus. Five AFLP markers localized in the vicinity of the identified QTL were sequenced to convert them into sequence tagged site (STS) markers. Genotyping of each RI line using two AFLP-STS markers and the vrs1 locus indicated that the RI lines with three Russia 6 QTL alleles exhibited the same level of high FHB resistance reactions as Russia 6. In contrast, RI lines with three susceptible alleles showed reactions close to H.E.S. 4. Therefore, the markers closely linked to the QTL can be efficiently used for the selection of resistance.

Chromosome Mapping↗
PubMed2005

Hippocalcin-deficient mice display a defect in cAMP response element-binding protein activation associated with impaired spatial and associative memory.

Hippocalcin is a member of the neuronal calcium sensor (NCS) protein family that is highly expressed in hippocampal pyramidal cells and moderately expressed in the neurons of cerebral cortex, cerebellum and striatum. Here we examined the physiological roles of hippocalcin using targeted gene disruption. Hippocalcin-deficient (-/-) mice displayed no obvious structural abnormalities in the brain including hippocampal formation at the light microscopic level. Deletion of hippocalcin did not result in up-regulation of the hippocalcin-related proteins; neural visinin-like Ca(2+)-binding proteins (NVP) 1, 2, and 3. The synaptic excitability of hippocampal CA1 neurons appeared to be normal, as estimated by the shape of field excitatory postsynaptic potentials elicited by single- and paired-pulse stimuli, and by tetanic stimulation. However, N-methyl-d-aspartate stimulation- and depolarization-induced phosphorylation of cAMP-response element-binding protein (CREB) was significantly attenuated in -/- hippocampal neurons, suggesting an impairment in an activity-dependent gene expression cascade. In the Morris water maze test, the performance of -/- mice was comparable to that of wild-type littermates except in the probe test, where -/- mice crossed the previous location of the platform significantly less often than +/+ mice. Hippocalcin-deficient mice were also impaired on a discrimination learning task in which they needed to respond to a lamp illuminated on the left or right side to obtain food reinforcement. No abnormalities were observed in motor activity, anxiety behavior, or fear learning. These results suggest that hippocalcin plays a crucial role in the Ca(2+)-signaling pathway that underlies long-lasting neural plasticity and that leads to spatial and associative memory.

Animals↗
PubMed2005

Association between IL-18 gene promoter polymorphisms and inflammatory bowel disease in a Japanese population.

BACKGROUND: Interleukin-18 (IL-18) is a pleiotropic cytokine that induces the production of interferon (IFN)-gamma and also to regulate Th2 cytokines. Recently, association studies between IL-18 gene promoter polymorphisms and several Th1- or Th2-mediated inflammatory diseases were reported. In inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), recent evidence suggests that IL-18 is involved in the pathogenesis. METHODS: Using DNA direct sequencing, we investigated IL-18 gene promoter polymorphisms at -607C/A and -137G/C. Allele, genotype, and haplotype frequencies were determined in 210 Japanese patients with UC, 205 patients with CD, and 212 controls. RESULTS: In UC, the -137C allele frequency was significantly higher in the proctitis-type patients than in controls (Pc = 0.0068). The -137 genotype frequency was also significantly different in the proctitis-type patients than in controls (Pc = 0.032). No other allele and genotype frequencies were significantly associated with UC after Bonferroni correction. Furthermore, the frequency of haplotype 2 (-607A, -137C), which had a lower promoter activity and IFN-gamma mRNA level than the other haplotypes as previously reported, was significantly higher in the proctitis-type patients than in controls (Pc = 0.01). In CD, we could not find any significant differences. CONCLUSIONS: IL-18 gene promoter polymorphisms may not be associated with disease susceptibility but related to the extent of disease in UC.

Adolescent↗
PubMed2005

Resolution of primary amyloidosis by melphalan and prednisolone: a case report.

We here report a case of a 50-year-old man who showed histologically evident resolution of primary amyloidosis by melphalan and prednisolone. The patient was admitted to our hospital for further evaluation of nephrotic syndrome and remarkable hepatomegaly with refractory ascites, on September 11, 1998. Laboratory tests at presentation showed nephrotic syndrome with slight renal impairment and elevation of the enzymes of the biliary system. Monoclonal light chains were not detected in the serum or urine by immunoelectrophoresis. A renal biopsy revealed global deposition of amyloid in all glomeruli, interstitium and blood vessels. Immunofluorescence staining was positive for kappa light chains. Liver biopsy specimens showed extensive deposition of amyloid along sinusoid walls. Bone marrow aspiration contained 7% plasma cells but no clusters or abnormal cells. Based on these findings, systemic AL- (amyloid light chain) amyloidosis was diagnosed, and the treatment with combinations of melphalan and prednisolone was started from October 1998 at intervals of 4-6 weeks. Renal impairment progressed, resulting in the initiation of maintenance hemodialysis in February 1999. Reinfusion of ascitic fluid into the hemodialysis circuit had been performed from March 1999 for refractory ascites, and ascites disappeared in July 1999. Furthermore, urinary output increased after 14 courses of chemotherapy. Renal function gradually ameliorated with a concomitant reduction in the enzymes of biliary system, and finally hemodialysis was discontinued in April 2001. Sixteen courses of chemotherapy were administered by April 2001. Proteinuria was negative in August 2001. A second renal biopsy was performed on November 20, 2001, which showed markedly decreased amyloid deposition and a proliferation of mesangial cells and increase in matrix in various degrees. We report a case of a patient with primary amyloidosis who was successfully treated by melphalan and prednisolone, resulting in marked resolution of renal amyloidosis.

Alkylating Agents↗
PubMed2005

Dynamics of airborne pollen particles from inhalation to allergic reaction in the nose.

BACKGROUND: Pollinosis is common worldwide, and has been frequently studied. However, the intranasal dynamics of pollen grains have not yet been documented. The purpose of this study is to elucidate for the first time the dynamics of Japanese cedar pollen (JCP) in the human nose at consecutive steps from inhalation to allergic reaction together with release of Cry j 1 (a major allergenic component of JCP) in the nose. METHODS: A personal sampler collected airborne pollens at head height outdoor on the street, while intranasal pollens after natural or experimental inhalation were collected by irrigation with 200ml saline. Cry j 1 in the supernatant after in vitro incubation with phosphate buffered saline or lavage was determined by enzyme-linked immunoassay. RESULTS: Head-height pollen was 183.0 +/- 43.1/300L/h, with 99% of the inhaled pollens deposited on the nasal surface. Eighty eight% of the inhaled pollen was transported to the out-side of the nose by ciliary function within 3 hours. During this process, considerable amounts of Cry j 1 were released in the nose reaching its plateau within 30 min. When the number of pollen deposited exceeded more than approximately 65 particles, symptoms may occur, leading presumably up to a 74% reduction of the intra-nasal pollen. CONCLUSION: The majority of inhaled airborne pollens was deposited on the nasal mucosal surface and moved out from the nose by mucociliary transportation. During this process, when allergenic substances are released up to a critical concentration, allergic reactions occur leading to expelling of pollen from the nose followed by subsiding of the symptoms.

Adult↗
PubMed2004

Induction of tumour blood flow stasis and necrosis: a new function for epinephrine similar to that of combretastatin A-4 derivative AVE8062 (AC7700).

AVE8062, a derivative of combretastatin A-4, has a strong stanching effect on tumour blood flow (TBF), which leads to complete blockage of nutrient supply to solid tumours and their necrosis. Previously, we reported that TBF stasis is due to increased arteriolar resistance caused by AVE8062 and a lasting decrease in perfusion pressure in tumour-feeding vessels. Here, we measured changes in TBF in rat solid tumour LY80 during continuous administration of AVE8062-like epinephrine or four catecholamines that are unlike AVE8062 (norepinephrine, dopamine, methoxamine, and metaraminol) to the region of increased vascular resistance. Venous administration of 0.3 mg ml(-1) epinephrine caused TBF to fall immediately to near zero, where it remained throughout the administration period. With a 30-min drug administration, TBF began to recover immediately when drug administration halted. With a 60-min epinephrine administration, TBF recovered somewhat, but not to the previous level. With drug administration of 120 min, TBF did not recover during the subsequent 8 h. Likewise, 0.1 mg ml(-1) epinephrine produced irreversible occlusion after 120 min of administration. In contrast, 120 min of administration of the four other catecholamines resulted in no occlusion. Only the group given 0.3 mg ml(-1) epinephrine (not that given methoxamine) showed significantly greater necrosis than the control. We conclude that, for epinephrine to cause irreversible occlusion of these vessels, a marked decrease in perfusion pressure in tumour-feeding blood vessels is necessary and should be maintained for 2 h. This conclusion is consistent with the previously demonstrated mechanism of irreversible arteriole occlusion caused by AVE8062. AVE8062 and epinephrine appear to have the same mechanism of action regarding induction of tumour blood flow stasis.

Animals↗
PubMed2004

Bacillus amyloliquefaciens phage endolysin can enhance permeability of Pseudomonas aeruginosa outer membrane and induce cell lysis.

To determine the function of the C-terminal region of Bacillus amyloliquefaciens phage endolysin on Pseudomonas aeruginosa lysis, the permeabilization of the outer membrane of P. aeruginosa was analyzed. Glu-15 to His (E15H) and Thr-32 to Glu (T32E) substitutions were introduced into the Bacillus phage endolysin. Neither E15H nor T32E substitution induced enzymatic and antibacterial activities. These two, Glu-15 and Thr-32, were considered to be the active center of the enzyme. The addition of purified E15H and T32E proteins to P. aeruginosa cells induced the release of periplasmic beta-lactamase from the cells, indicating that both proteins enhance permeabilization of the outer membrane. However, the addition of E15H and T32E proteins to P. aeruginosa cells did not induce the release of cytoplasmic ATP from the cells. These results indicate that the antibacterial activity of the endolysin requires both the C-terminal enhancement of the permeabilization of the P. aeruginosa outer membrane and N-terminal enzymatic activity.

Anti-Bacterial Agents↗
PubMed2003

Microvascular mechanisms by which the combretastatin A-4 derivative AC7700 (AVE8062) induces tumour blood flow stasis.

We previously reported that a novel combretastatin A-4 derivative, AC7700, has remarkable antitumour effects because of an irreversible stasis of tumour blood flow (TBF) and subsequent loss of nutrient supply to tumour tissue. Since early 2002, under the new designation AVE8062, AC7700 has undergone clinical trials in Europe and the US. Questions remain, however, concerning how AC7700 blocks TBF and why the TBF stasis does not recover. In this study, using a rat tumour LY80, a variant of Yoshida sarcoma, we examined whether TBF cessation after AC7700 administration is due to a direct action of the agent on tumour blood vessels. We constructed electrodes that can drop a small quantity of the drug solution directly at the site of blood flow measurement and inserted them subcutaneously and into the tumour. We compared the blood flow responses of normal vessels and tumour vessels after administration of 10-microl doses of various concentrations (0.2, 1, 10, and 50 mg ml(-1)) of the AC7700 solution. In addition, we assessed TBF stasis after i.v. and intra-arterial 10 mg x kg(-1) AC7700 administration in an LY80-induced kidney tumour. To determine why the TBF stasis is irreversible, we observed AC7700-induced changes in host arterioles and the tumour vascular network of the Sato lung carcinoma using a vital microscopic rat transparent chamber. Since an increase in tumour interstitial fluid pressure brings about a decrease in TBF, we also measured 10 mg x kg(-1) AC7700-induced changes in this pressure. The sensitivity of the blood flow response after intratumoral application of AC7700 was markedly higher in normal vessels relative to tumour vessels. Intra-arterial administration of AC7700 did not have stronger effects on TBF stasis than did i.v. administration. Intravital microscopy showed that AC7700 induced a powerful and long-lasting constriction of host arterioles, so that complete stasis of blood flow occurred in downstream vessels, which supplied blood to tumours. Owing to this stasis, the lumens of numerous tumour vessels narrowed or completely disappeared, and numerous erythrocytes stagnated in drainage vessels of the tumour vascular network. Haemolysis of these erythrocytes occurred after 2-3 h, resulting in complete thrombosis. There was no indication of reperfusion in vessels showing haemolysis. This haemolysis is thought to be the main cause for the irreversibility of TBF stasis. Since the tumour interstitial fluid pressure decreased after i.v. AC7700 administration, the possibility of stasis of TBF being caused by tumour vascular compression was excluded. All these results strongly suggest that the main target of AC7700 is host arterioles and that the stasis of TBF induced by AC7700 is not triggered by a direct action of the drug on tumour vessels.

Animals↗
PubMed2003

Toward rational control of Escherichia coli O157:H7 by a phage cocktail.

Twenty six phages infected with Escherichia coli O157:H7 were screened from various sources. Among them, nine caused visible lysis of E. coli O157:H7 cells in LB liquid medium. However, prolonged incubation of E. coli cells and phage allowed the emergence of phage-resistant cells. The susceptibility of the phage-resistant cells to the nine phages was diverse. A rational procedure for selecting an effective cocktail of phage for controlling bacteria was investigated based on the mechanism of phage-resistant cell conversion. Deletion of OmpC from the E. coli cells facilitated the emergence of cells resistant to SP21 phage. After 8 h of incubation, SP21-resistant cells appeared. By contrast, alteration of the lipopolysaccharide (LPS) profile facilitated cell resistance to SP22 phage, which was observed following a 6-h incubation. When a cocktail of phages SP21 and SP22 was used to infect E. coli O157:H7 cells, 30 h was required for the emergence of cells (R-C) resistant to both phages. The R-C cells carried almost the same outer membrane and LPS components as the wild-type cells. However, the reduced binding ability of both phages to R-C cells suggested disturbance of phage adsorption to the R-C surface. Even though R-C cells resistant to both phages appeared, this work shows that rational selection of phages has the potential to at least delay the emergence of phage resistance.

Adsorption↗
PubMed2003

Efficient construction of high-density linkage map and its application to QTL analysis in barley.

Using a High Efficiency Genome Scanning (HEGS) system and recombinant inbred (RI) lines derived from the cross of Russia 6 and H.E.S. 4, a high-density genetic map was constructed in barley. The resulting 1,595.7-cM map encompassed 1,172 loci distributed on the seven linkage groups comprising 1,134 AFLP, 34 SSR, three STS and vrs1 (kernel row type) loci. Including PCR reactions, gel electrophoresis and data processing, 6 months of work by a single person was sufficient for the whole mapping procedure under a reasonable cost. To make an appraisal of the resolution of genetic analysis for the 95 RI lines based on the constructed linkage map, we measured three agronomic traits: plant height, spike exsertion length and 1,000-kernel weight, and the analyzed quantitative trait loci (QTLs) associated with these traits. The results were compared on the number of detected QTLs and their effects between a high-density map and a skeleton map constructed by selected AFLP and anchor markers. The composite interval mapping on the high-density map detected more QTLs than the other analyses. Closely linked markers with QTLs on the high-density map could be powerful tools for marker-assisted selection in barley breeding programs and further genetic analyses including an advanced backcross analysis or a map-based cloning of QTL.

Chromosome Mapping↗
PubMed2003

Repositioning of the vertebral artery with titanium bone fixation plate for trigeminal neuralgia.

BACKGROUND: Trigeminal neuralgia is usually treated by the padding method using Teflon felt. However this can not be done in certain cases in whom a large tortuous vertebrobasilar artery compresses the fifth nerve. The transposition method using the sling may be an alternative method. But this method is not an easy procedure and requires a relatively large craniotomy. Two cases were treated by a new and simpler effective technique. CLINICAL PRESENTATION: Two cases of the trigeminal neruralgia were treated. The first case was a 71 year-old male and the second case was a 63 year-old male. The history of the medical treatments were similar and both cases had had trigeminal nerve blocks and were prescribed carbamazepin. However, the pain control was insufficient in both cases. In both cases, three dimensional computerized tomography showed the large tortuous right vertebral artery ran just behind the clivus and compressed the right trigeminal nerve. In the second case past history showed a recent hypertensive cerebellar hemorrhage. TECHNIQUE AND RESULTS: A right suboccipital craniotomy were performed in both cases. In both cases, the right vertebral artery compressed the trigeminal nerve in a rostral direction. The sling technique with nylon sutures was tried in both cases but failed during surgery. Then, the bone fixation stainless plate was cut to 10 cm in length and pre-shaped with pliers. After being shaped, the distal end of the plate was inserted between the vertebral artery and fifth nerve and the proximal end of the plate was fixed to the skull by screw. The fifth nerve was completely isolated from the artery as they were in direct contact. After surgery, the pain disappeared completely during the follow-up of one and a half year in the first case and 9 months in the second case. CONCLUSION: The plate can be bent and curved with plier to suit each individual case. This technique is easily applied even when the slings or other isolation technique is not available and appeared to achieve the mechanically stronger reposition and fixation of a very large and tortuous artery away from the trigeminal nerve.

Aged↗
PubMed2003

Differential relationship between changes in tumour size and microcirculatory functions induced by therapy with an antivascular drug and with cytotoxic drugs. implications for the evaluation of therapeutic efficacy of AC7700 (AVE8062).

A novel combretastatin A-4 derivative, AC7700, which is now in Phase I clinical trials under a new code, AVE8062, has shown strong antitumour effects against solid tumours in rodents because of its powerful and continued stanching of the tumour blood flow (TBF). Despite the strong tumour-suppressing qualities of AC7700, it does not produce an immediate reduction in tumour size. To elucidate the reason for this effect, we investigated the relationship between the change in tumour size in Sato lung carcinoma (SLC) and circulatory functions after therapy with AC7700, doxorubicin (Adriamycin [ADR]), or mitomycin C (MMC). To measure time-lapse changes in TBF with the hydrogen clearance method at the same site after drug administration, we developed a new apparatus for keeping electrodes within a tumour. AC7700 led to the destruction of both cancer cells and tumour vessels by interrupting the supply of nutrients. Intravenous (i.v.) administration of fluorescent dyes after AC7700 treatment revealed no fluorescence within the tumour vessels, which confirmed that the tumour microcirculation had been completely blocked. In contrast, ADR led to the destruction of SLC tumour cells, but did not have the same effect on tumour vessels. Intravenously administered fluorescent dyes immediately reached the tumour, which indicated that the tumour vasculature remained intact, and the TBF remained at the preadministration level, even 6 days after ADR treatment. In addition, although the size of the tumour increased slightly for 2 days with ADR treatment, possibly because of swelling of the cancer cells, thereafter it continued to decrease. MMC had virtually no effect on SLC tumour cells, tumour size or tumour vessels. We conclude that changes in tumour size brought about by cancer chemotherapy depend not only on the sensitivity of the cancer cells to the drug in question, but also on the nature of changes in the microcirculatory functions of the tumour brought about by the therapy. When both tumour cells and the tumour vasculature are destroyed, the effectiveness of therapy can not be determined from changes in tumour size alone.

Animals↗
PubMed2003

Intestinal goblet cell autoantibody associated enteropathy.

This report describes a case of refractory enteropathy with circulating intestinal goblet cell autoantibodies (IGA). A 19 year old man with hyperthyroidism had suffered from protracted diarrhoea for nearly 10 years. Histological examination showed evidence of collagenous enterocolitis. The diarrhoea did not improve despite fasting under total parenteral nutrition. An immunofluorescence assay demonstrated IGA without anti-enterocyte autoantibodies, the hallmark of autoimmune enteropathy, although other criteria were fulfilled. None of 109 controls, including 55 cases of inflammatory bowel disease and one of lymphocytic colitis, had IGA. This case is considered to be a variant of autoimmune enteropathy, and might be a distinct entity.

Adult↗
PubMed2003

High fidelity SNP genotyping using sequence-specific primer elongation and fluorescence correlation spectroscopy.

Reliable, efficient and cost-effective modalities are urgently needed for mass screening of gene mutations. Previous reports have shown that SSCP or genechip methods require substantial time and monetary costs, thus limiting their appeal. Sequence Specific Primer Polymerase Chain Reaction (SSP-PCR) is a reliable and cost-effective method that utilizes the 3'-end discrimination properties of polymerase. However, the applicability of conventional SSP-PCR is limited due to the difficulties associated with determining optimal conditions and because mis-matched primers are amplified, resulting in signal noise during end-point assay. To overcome this problem, we eliminated the reverse primers from SSP-PCR, thus preventing amplification of mis-matched primers. We designated this method Sequence-Specific Primer Cycle Elongation (SSPCE). However, the detection of elongated sequence specific primers was difficult using conventional electrophoresis due to the small amounts of amplification product present. We therefore combined SSPCE and Fluorescence Correlation Spectroscopy, which is a novel technique used to determine the number and size of fluorophores at nano-molar concentrations, and designated the method SSPCE-FCS. We compared conventional SSP-PCR and SSPCE-FCS with regard to determining optimal conditions using two Mitochondrial SNPs (G --> A at position 1598, G --> A at position 12192). We were able to determine the optimal conditions for the SNP at position 1598 using either method. However, optimal conditions could only be determined for SSPCE-FCS with the 12192 mutation because non-specific amplification was observed at a wide range of annealing temperatures in SSP-PCR. We then applied this method to three other SNPs and the results were consistent with the results of sequencing data.

Base Sequence↗