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分娩後数日から1か月後までの褥婦の不安の程度と変動の実態を明らかにする目的で, 681名の褥婦に対し, 入院中, 退院1週後, 分娩1か月後の継続的な調査を行った。不安の測定尺度は, STAIを用いた。532名の褥婦から3回連続の調査協力が得られ, 有効回答数は528であった。状態不安得点は, 入院中37.5点, 退院1週後39.5点, 分娩1か月後392点であり, 初産婦のほうが高かった。特性不安得点は, 入院中39.2点, 退院1週後39.3点, 分娩1か月後39.7点であった。褥婦の背景と不安得点は, 学歴や月経時, 悪阻時に自覚する症状, 分娩の認識において有意な関連があった。状態不安得点を高中低の3群に分け, 1か月までの変動を追跡した。入院中に中等度不安群だった褥婦も, 1週後に高不安群へ移行していれば1か月後に低不安群へ移行することは少なく, 1週後に低不安群に移行していれば1か月後に高不安群へ移行することはまれであった。

We report an extremely rare case of familial breast cancer with deleterious germline mutations in both BRCA1 and BRCA2 genes, of which, to date, no such case has been reported among Japanese breast/ovarian cancer patients. Genetic testing of the family members indicated that the same double heterozygosity for BRCA1 and BRCA2 genes was transmitted to the paternal cousin, and the same BRCA2 mutation to the younger sister with bilateral breast cancer, younger brother with stomach cancer, and proband’s son and daughter without cancer. Immunohistochemical analysis of BRCA protein expression was performed using breast cancer tissues from the proband with double heterozygosity for BRCA1 and BRCA2 genes and from her sibling without BRCA1 mutation but with BRCA2 mutation. There was no staining of either BRCA in the proband and no staining of BRCA2 in the sibling.

A 22-year-old woman had a well differentiated nephroblastic tumor. The tumor was composed of mesenchymal elements with mature tubules and occasionally smooth muscle elements. None of the cellular elements showed any feature indicative of malignancy. Histologically this was similar to congenital mesoblastic nephroma, but the tumor showed an evidence of a uniform expansile growth. It was considered to be a form of mature nephroblastoma.

The expression of adhesion molecules of lymphoma cells were studied using immunohistochemical and flow-cytometrical techniques on 187 cases with non-Hodgkin's lymphomas (NHL) of B and T cell origin. Cell adhesion molecules used in the study were as follows; LFA-1 (CD11a/18), ICAM-1 (CD54), CD44, LFA-3 (CD58), Leu8 and VLA-4 (CDw49d). The LFA-1 was more highly expressed in T cell lymphomas (44/53; 84%) than B cell lymphomas, (50/134; 37%). The expression of ICAM-1 was observed in 75 of 134 cases (56%) of B cell lymphomas and in 18 of 53 cases (34%) of T cell lymphomas. CD44 was highly expressed in both B (109/134; 81%) and T cell lymphomas (43/53; 83%). Based on bone marrow examination of 90 cases with B cell lymphomas, bone marrow involvement was observed in 4 of 6 cases (67%) with LFA-1 and without ICAM-1, in 11 of 21 cases (52%) with ICAM-1 and without LFA-1 and in 20 of 34 cases (59%) without ICAM-1 and LFA-1. On the other hand, only 4 of 29 cases (14%) with ICAM-1 and LFA-1 showed bone marrow involvement, which is markedly lower than above groups (p

The patient was a 50-year-old woman with a palpable tumor and pain in the right breast in May of 2008. The tumor was then diagnosed as an atheroma. The tumor enlarged rapidly in June, and the pain and the redness had worsened. The patient was then referred to our hospital. The tumor was in the upper inner quadrant of the right breast with surface redness, measuring about 3 cm. In the mammographic (MMG) findings, the tumor shadow was in the upper inner quadrant of the right breast and was observed to be circular and have a high density with a plain boundary and slightly roughed edges. In the ultrasonographic (US) findings, an oval-shaped high echoic region was found subcutaneously in the right breast. Because the high echoic area was subdivided in the partition of the low echoic string, it looked like a pebbled wall. Upon core needle biopsy, this case was diagnosed as malignant lymphoma. After comparing the histopathology and the US image, it was determined that the pebbled wall-shaped image was due to lymphocyte infiltration of the tissue. The US image was peculiar and we report this case as a peculiar example of malignant lymphoma.

The gating mechanism of localized ion-conducting pores or channels in excitable membranes is discussed based on the ferroelectric model hypothesized by Leuchtag, and excitation is analyzed by a diffused electrical bilayer model. By the application of a self-organized chemical model to such membranes, which have ferroelectric transmembrane units, the membrane potential in ionic circumstances of aqueous electrolytic media is described by a nonlinear equation derived from a phenomenological function for a parameter that characterizes a phase transition of the membranes. The excitation appears with a jump in the potential at one of the points on the bifurcation sets at which the discriminant of the equation equals zero; the point represents the reaction threshold. Because the membrane potential is controlled by two variables (control parameters) in the nonlinear state equation, the jump is cusp catastrophic. The potential of a few types of membranes has been calculated by assuming suitable functions for these...

A case of primary splenic histiocytic sarcoma is reported.A 29-year-old man was admitted to Fukushima Medical College Hospital for pretibial edema. Physical examination showed splenomegaly without lymphadenopathy and hepatomegaly. Laboratory findings revealed thrombocytopenia and hypoproteinemia, and bone marrow aspirate and biopsy were normal. Clinically, splenic malignant lymphoma was suspected and surgical splenectomy was performed. His symptoms resolved after the treatment.The spleen weighed 730g and a well-defined reddish-colored tumor was observed on cut surface. The tumor was composed of an intense infiltration of variable sized histiocytic cells, from 8μm to 20μm in diameter, containing abundant eosinophilic cytoplasm and large round to oval nuclei.Mitotic figures were a few and multinuclated giant cells were occasionally seen. The tumor cells were considered as monocyte/histiocyte series based on cellular morphology and immunological charactaristics for monocytic markers and germline of immunogloblin heavy chain (JH) and T-cell recepter beta chain (Cβ1) genes. Flow-cytometric DNA analysis showed a hypodiploidy pattern. These findings indicate that the present case is primary splenic histiocytic sarcoma with low grade malignancy.

Experimental animal pain models involving peripheral nerve lesions have expanded the understanding of the pathological changes caused by nerve damage. However models for the pathogenesis of chronic pain patients lacking obvious nerve injuries have not been developed to the same extent. Guided by clinical observations, we focused on the initiating noxious event, the context when applying nociceptive stimulation targeting long-lasting pain elicited by muscle insult. The administration of a nociceptive agent (6% hypertonic saline: HS; 5-time repeated-injection: HS5) after pretreatment with an immuno-inflammatory agent (lipopolysaccharide: LPS, 2 μg/kg) into one gastrocnemius muscle produced markedly long-persisting biphasic sustained mechanical hypersensitivity on the plantar surface of both hindpaws. In the acute phase, the blockade of afferent inputs from the injected-site was effective in returning the contralateral enhanced-responses to baseline levels. In contrast, similar blockade during the chronic phase did not affect the contralateral enhanced-responses, indicating that the hypersensitivity in the two phases was probably induced by different mechanisms. However, increasing the dose of LPS (20 μg/kg) before applying HS5 eliminated the development of mechanical hypersensitivity in the chronic phase, while the hypersensitivity in the acute phase was significantly more severe than with low-dose LPS-pretreatment. In this model, the development of hypersensitivity could be modulated by manipulating LPS-doses prior to noxious stimulation. This novel chronic pain model based on a preceding ‘priming’ myalgic stimulus provides an intriguing means for studying the pathogenesis of chronic pain.

TSUCHIYA, S., MINEGISHI, M., FUJIE, H., MINEGISHI, N., OHASHI, Y., ITANO, M., MORITA, S., YAMAGUCHI, Y., SATO, T. and KONNO, T. Allogeneic Bone Marrow Transplantation for Malignant Hematologic Disorders in Children. Tohoku J. Exp. Med., 1992, 168 (2), 345-350- In the present study we carried out allogeneic bone marrow transplantation (BMT) in 14 leukemia children with high risk prognostic factors. Six patients with acute nonlymphocytic leukemia (ANLL), four with acute lymphocytic leukemia (ALL), two with chronic myelogenous leukemia (CML), and two with myelodysplastic syndrome (MDS). Among these patients, six with ANLL, two with ALL, one with CML and one with MDS were alive in complete remission 8 to 58 months post-BMT. Four patients died of relapse (one with ALL, and one with MDS), and chronic GVHD (one with ALL and one with CML). In six patients recombinant granulocyte colony stimulating factor (rG-CSF)was used to shorten the period of granulocytopenia. The mean time of recovery to granulocyte count of 500/mm3 was 13.2 days in the rG-CSF+group, being 15.9 days faster than that in the rG-CSF-group. In light of these results, allogeneic BMT is shown to be a choice of treatment for leukemia children with high risk prognostic factors and rG-CSF may be an effective reagent to prevent infectious episodes in BMT.- allogeneic bone marrow transplantation; leukemia; high risk prognostic factors; recombinant granulocyte colony stimulating factor

An analytical cross-sectional study was conducted with 812 subjects aged 35-74 years in Prek Russey commune, Cambodia to detect some factors associated with severe periodontitis. Four calibrated examiners employed Community Periodontal Index (CPI) to ascertain periodontal pocket depth (PD) and loss of epithelial attachment (LA). A questionnaire was used to obtain tobacco and alcohol consumption habits. One hundred (12.3%) subjects had one or more sextants with ≥ 4mm PD and ≥ 6mm LA (severe periodontitis). Smoking, tobacco chewing and age were significantly associated with severe periodontitis in bivariate analysis while only age and quantified smoking remained significant in a logistic regression analysis. The impact of quantified smoking on severe periodontitis was almost negligible [OR: 1.0006 (95% CI: 1.0001, 1.001)] compared to that of age [OR ranged from 8.3 at 45-54 years to 22 at 65-74 years (95% CI: 3.1, 62.3)]. Nevertheless, both age and quantified smoking can be considered as factors associated with severe periodontitis in rural Cambodians. Asia Pac J Public Health 2004; 16(1): 50-53.

This paper presents the capability of changing the activation energy of chemical reactions using microchannel laminar flow. Kinetic parameters of the duplex–coil equilibrium of DNA oligomers were studied by measuring the hysteresis between denaturation–renaturation curves using an in-house temperature-controllable microchannel-type flow cell. For this study, DNA oligomers were used because they allow physicochemical analysis and theoretical discussion. Kinetic parameters of the duplex–coil equilibrium of DNA oligomers were obtained by measuring the denaturation–renaturation hysteresis curves. Both cooling and heating curves were shifted to the high-temperature side at higher flow rates. The renaturation reaction was influenced by a slower flow rate. The effect of the slower flow rate was more pronounced for renaturation than denaturation reactions. The magnitude of the activation energies of association decreased as the flow rate increased, but that of the activation energies of the dissociation increased as the flow rate increased. Overall, these results suggest that chemical reactions' change of activation energy depends on the flow rate and the DNA molecular size.

The combination of Mo and cationic Au catalysts dramatically accelerated the rearrangement of diverse propargyl alcohols, which includes a short reaction time, mild conditions, and high product yields. A practical application to the highly challenging primary propargyl alcohols and the N-alkynyl amides is achieved.

A dissipative system is approximated by a nonlinear rate equation: Z congruent to K1Z - K2Z3 (K2 greater than 0), in which the right side is derived from -delta G/delta Z of Taylor's series of the thermodynamic potential given by Gibbs' function G(Tc, Pc) (Z) at about the critical point C(Tc, Pc) of the control variables (parameters) T and P. The stability or instability of the system is treated by the changes in the control parameters. In the case that T not equal to P not equal to 0 in the steady state, Z = 0, and T and P pass the point C, K1 becomes negative. By this change, the G function is convex at Z = 0 and each product is created rapidly with concentration or number of the molecules Z = ([K1]/K2)1/2. This dynamic theory is applied to enzyme cascades. Based on cyclic GMP (cGMP) hypothesis in visual transduction, the cascade hydrolysis of cGMP of vertebrates is analyzed by dividing it into two-step reaction cascades: The initial process is that metarhodopsin II catalyzes the exchange of GDP for GTP by transducin (Gtd) and that GTP-Gtd complex is hydrolyzed to GDP-Gtd complex. In the following cascade cGMP is hydrolyzed with amplification of phosphodiesterase (PDE) activated by the removal of the small inhibitory subunit. The quantity of the hydrolysis of cGMP is estimated as approximately 5 x 10(4-5) molecules per photolyzed rhodopsin semiempirically, and this coincides well with experiments.

Optical properties of semiconductor nanocrystals possess characteristic dependence on temperature thus, making them good candidates for temperature sensors. Therefore, we synthesized CdSe, CdSe/ZnS and CdSe/ZnSe/ZnS core/shell type semiconductor nanocrystals in micro-space a optimized the structure of composite semiconductor nanocrystals to obtain high quantum yield with a high stability for thermo-sensing.

We developed a simple immobilisation method for His-tagged enzymes on a microchannel surface. It facilitates immobilisation of protein molecule on microchannel surface through Ni-complex, using crude or purified protein solutions. By this method, we could immobilize proteins on microcapillary constantly. This method might be useful for further development of microreactor with reversibly immobilized enzymes.

We used a microreactor for CdSe nanocrystal preparation and explored the effects of experimental conditions on the properties of the products. The particle growth kinetics and photoluminescence properties of the nanocrystals showed identical trends to previous reports, indicating the efficiency of the current method for analysis of rapid nanocrystal synthesis as well as industrial production of CdSe nanocrystals.

A case of breast cancer that metastasized to the cervix 10 years and 8 months after mastectomy is reported. The patient had undergone pancreaticoduodenectomy due to solitary metastasis to the head of the pancreas 4 years previously. The cervical metastasis was associated with abnormal genital bleeding. After pancreaticoduodenectomy the serum levels of CEA, CA15-3 and NCC-ST-439, which are markers of breast cancer, were within normal limits, but the serum level of CA15-3 had increased month by month. The patient had abnormal genital bleeding and presented to the department of gynecology at our hospital. The tumor was in the cervix, bled easily and 2.5 × 2.0 cm in size on ultrasonography. It was thought to be carcinoma of the cervix, but biopsy revealed the tumor to be an adenocarcinoma pathologically and CA15-3 was immunohistochemically demonstrated in the resected specimen, similar to lobular carcinoma of the breast. Abdominal CT scan revealed involvement of the ovaries and uterus, prompting hysterectomy with bilateral oophorectomy. After discharge, she received chemoendocrine therapy. However, she subsequently died due to peritoneal carcinomatosis.

There is a paucity of information pertaining to oral disease patterns including periodontal disease in Cambodia, which is just emerging from a 20-year ruin. A house-to-house survey was conducted to assess the periodontal status of 1948 subjects aged 15-74 years in a rural commune in Cambodia using Community Periodontal Index (CPI) and measuring Attachment Loss (LA). The periodontal status of Cambodians increased with age as indicated by both CPI and LA. Calculus was the most common finding among Cambodians pointing to overall poor oral hygiene levels. Notwithstanding the poor oral hygiene, however, the severe periodontitis as denoted by ≥ 6mm periodontal pockets was rare even in the elderly while edentulousness was not frequently observed until 65 years. Preventive programmes targeting periodontal disease in Cambodia should focus on oral health education and simple oral hygiene instructions while the ubiquitous calculus could be dealt with oral prophylaxis. Asia Pac J Public Health 2002; 14(2): 105-109.

A micro-reactor was utilized for continuous and controlled CdSe nanocrystal preparation. Effects of reaction conditions on optical properties of the nanocrystals were investigated; in this current system, rapid and exact temperature control of the micro-reactor was beneficial for controlling particle diameter and reproducible preparation of particles; additional effort was made towards narrower particle-size distributions.

ITANO, M., MORITA, S., FUJIE, H., OHASHI, Y., MINEGISHI, N., MINEGISHI, M., YAMAGUCHI, Y., SATO, T., TSUCHIYA, S., KONNO, T., HAYASHI, Y., OHI, R. and SHIRAISHI, H. Mass Screening for Neuroblastoma in Miyagi Prefecture. Tohoku J. Exp. Med., 1992, 168 (2), 137-139 - In Japan, aiming at early and preclinical detection of neuroblastoma in infancy a mass screening program for the tumor has been implemented nationwide using urinary tests for catecholamine metabolites, vanillylmandelic acid (VMA) and homovanillic acid (HVA) (Sawada 1990; Sawada et al. 1991). In this report, the results obtained from the screening program in Miyagi Prefecture for the last 6 years are described. The detection rate of neuroblastoma by mass screening was 1:8, 377 among 125, 652 infants tested in Miyagi Prefecture. All but one patients survived after removal of the primary tumor and none or minimal chemotherapy. - neuroblastoma; mass screening; urine VMA; urine HVA

Okinawa Prefecture has been promoting dental treatment and oral health care in places where there are no dentists. The Ministry of Health and Welfare has been cooperating with eight dental colleges, including Tokyo Medical and Dental University, for promotion thereof since 1961. The 155th promotion was held on Tokashiki Island. The caries prevalence rate of the students on Tokashiki Island was relatively high compared with the average caries prevalence rate of the same age group throughout Japan, and most of the caries were thought to be due to too many soft drinks. Resin filling was the most popular treatment during this promotion. Severe periodontal disease was observed in middle-aged persons, but we could only perform initial periodontal treatment because of the limited treatment period. Complete or partial dentures were made or repaired for many elderly. The questionnaire study showed most of the denture wearers on Tokashiki Island were satisfied with their dentures, although many dentures did not fit, and the prescription was improved. The period of this promotion was too short to perform complete dental treatment and to prevent caries and periodontal disease, and primary prevention and higher dental hygiene education should be strengthened in no dentist areas like Tokashiki Island.

Non-invasive methods to measure brain function, particularly the methods of magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI), have improved rapidly and remarkably. With these methods, researchers have measured higher cortical functions of the living human brain, especially visual and auditory functions. MEG has the special advantage that it can trace the movement of cortical activity.

Kobayakawa et al. reported the development of a new gustatory stimulation apparatus for which the rise-time was less than 20 ms for a measurement of EEG [1]. They also modified the apparatus for a measurement of MEG, and reported the estimation of the source of the gustatory-evoked magnetic fields (GEMs) in the human cerebral cortex [2] [3]. In the present study we measured the reaction times (RTs) to the different taste qualities and compared them with the GEMs of different taste qualities to find the mutual relation between the reaction times and the onset of GEMs.

Fractionation of fine (∼10-μm) particles by their size, density, or both was studied. A laminar flow of suspended particles through a tilted slender tube that slowly rotates around the tube axis separated fine particles into two fractions according to the sedimentation velocity of the particles. The threshold of separation was mainly governed by the rotation period, which depends on the particle size. Nearly spherical particles of silica gel were separated experimentally. A two-step operation yielded a fraction of particles of uniform size (half-width, ∼0.7 μm) with a mean diameter of ∼5 μm. The particle-size threshold was close to the theoretical value

This paper reports a direct observation method of macromolecules, such as long-strand DNA, in microchannel flow, and also demonstrates that coil-stretch transition of DNA strands.

We report a case of fibroadenoma of the supernumerary breast of axilla, diagnosed by fine-needle aspiration. A 31-yearold pregnant woman reported a left. axillar mass. Cytological examination and fine-needle aspiration from the mass showed many clusters of cohesive epithelial cells with single, stripped nuclei and bipolar cells in the background. Histopathological examination of the surgical excisional sample showed a well-defined, capsulated pericanalicular type of fibroadenoma. The diagnosis of supernumerary breast is important because it can be a marker for urological and caldiovascular malformation.

Differences in the dental arch and palate among Taiwan Aboriginals were investigated and compared with Taiwanese and Japanese. Plaster models were taken from 315 Taiwan Aboriginal adults, 185 Taiwanese and 426 Japanese between 1979 and 1989, and various dimensions were measured. There were no clear differences in the characteristics of the dental arch and palate between Taiwan Aboriginal tribes. However, they were found to differ from those of Taiwanese and Japanese. In a dendrogram constructed from a cluster analysis, two major clusters were found. Among males, the first cluster contained Paiwan and Rukai, the second contained Japanese, Taiwanese, Ami and Bunun. Among females, the first contained Japanese, Taiwanese, Rukai and Paiwan, the second contained Ami and Bunun. The Ami were close to Bunun and the Paiwan were close to Rukai among both males and females. These results indicate that Ami and Bunun, and Paiwan and Rukai, respectively, have close affinities.

A Ca(2+)-ATPase gene was cloned from the genomic libraries of Plasmodium falciparum. From the deduced amino acid sequence of the gene, a 139 kDa protein with a total of 1228 amino acids was predicted. Sequence of a partial cDNA clone of the gene identified two introns near the 3′-end at the regions identical to the regions assumed for the Ca(2+)-ATPase gene of P. yoelii, a rodent malaria species. As compared with a variety of Ca(2+)-ATPases, the P. falciparum Ca(2+)-ATPase had the highest amino acid sequence homology (78%) to the P. yoelii Ca(2+)-ATPase, moderate homology (45-50%) to vertebrate sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases (SERCAs), and lowest homology (20%) to a plasma membrane Ca(2+)-ATPase. The P. falciparum protein conserved sequences and residues that are important for the function and/or structure of the organellar type Ca(2+)-ATPase, such as high affinity Ca(2+)-binding sites, fluorescein isothiocyanate (FITC)-binding regions, and the phosphorylation site, but the protein did not contain calmodulin-binding regions that occur in the plasma membrane type Ca(2+)-ATPase. Thus we concluded the cloned gene was the organellar type Ca(2+)-ATPase of P. falciparum. In a region between the phosphorylation site and FITC-binding region, the P. falciparum protein was about 200 residues longer than the rabbit SERCA and lacked a sequence that binds to phospholamban, a protein that regulates the activity of the rabbit SERCA.(ABSTRACT TRUNCATED AT 250 WORDS)

There have been an increasing number of reports describing a pivotal role for phosphorylation in cellular responses for cell differentiation and proliferation. We examined an immunocytochemical expression of protein kinase C(PKC) isozymes (type I, II, and III) in 22 leukemia-lymphoma cell lines. Of these cell lines, 21 expressed type II PKC and 17 showed the co-expression of both types II and III PKC in varying degree. The cell line without PKC activity showed far less [3H]-TdR uptake and no heterotransplantation in nude mice. Types II and III PKC appear to relate to cell proliferation in certain leukemia-lymphoma cell lines.

We investigated the expression of adhesion molecules of lymphocyte function-associated antigen-1 alpha (LFA-1 alpha) and its ligand intercellular adhesion molecule-1 (ICAM-1) on 74 well-characterized B cell lymphomas. The LFA-1 was expressed on B cell lymphomas (21/74; 28 per cent), but to a lesser degree than ICAM-1 which was highly expressed (48/74 cases; 64 per cent). From the results of bone marrow examination of 39 cases with B cell lymphomas, 13 of 16 cases with a lack of ICAM-1 molecule showed a higher incidence of marrow involvement, but nine of 23 cases with the expression of ICAM-1 molecule showed a lower incidence. These findings suggest that the lack of expression of the ICAM-1 molecule by B cell lymphomas correlates with bone marrow involvement by lymphoma cells (p < 0.05). Expression of the LFA-1 molecule appears not to correlate with marrow involvement (p < 0.05).

The authors have studied proliferation (growth fractions) in non-Hodgkin's lymphomas (NHL) using an immunohistochemical double staining technique with the monoclonal antibody (MoAb), Ki-67, in order to clarify the relationships between histologic type, proliferation and prognosis. The percentages of Ki-67 positive (Ki-67+) cells in B cell lymphomas were higher for diffuse lymphomas than for follicular lymphomas and increased in order from small to large cell types. In addition, the percentage of Ki-67+ cells in B cell lymphomas inversely correlated with survival in months (n = 33 r = -0.54 p < 0.01). These results indicate that the percentage of Ki-67+ cells in B cell lymphomas correlates with histologic type and prognosis. Although the prognosis of T cell lymphomas is considered worse than that of B cell lymphomas, the percentage of Ki-67+ cells was lower, in general, in T cell lymphomas than in B cell lymphomas. These data indicate that proliferation in T cell lymphomas does not correlate with survival.

We developed a novel microreaction system for optical resolution of racemic amino acids. This device, which is based on a continuous microfluidic system, consists of an enzyme-immobilized microreactor and a microextractor. Use of the enzyme-microreactor, which was prepared by membrane formation on the microchannel surface, enabled a highly enantioselective reaction for a racemic amino acid derivative. The microextractor provided a laminar flow of two immiscible solutions, which enabled selective extraction of the product. Using this integrated device, we could perform efficient continuous production of optically pure unnatural amino acids.

On-site detection methods for DNA have been demanded in the pathophysiology field. Such analysis requires a simple and accurate method, rather than high-throughput. This report describes a novel microfluidic analysis method and its application for simple sequence-selective DNA detection. The method uses a microchannel device with a serpentine structure. Sequence-specific binding of probe DNA can be detected at one side of the microchannel. This method is capable of sequence-specific detection of DNA with high accuracy. Single base mutations can also be analyzed. Combination of laminar stream and laminar secondary flow in the microchannel enable specific detection of probe-bound DNA.

Microchannel reactors have continued to attract attention in the fields of analytical and synthetic chemistry. An important feature of microchannel systems is their superior controllability of fluidic systems, which cannot be created in the batchwise reaction system with larger reaction apparatus. This study is designed to examine whether the superior controllability of microfluidics allows the use of microchannel reactors as a novel reaction control apparatus. Microfluidic analysis of ceramic microreactors using a solvatochromic dye demonstrated that the mixing of two solvents was strongly affected by the secondary flow that occurs at the corners of a microchannel. We examined the effects of such a microfluidic system on chemical reactions using amino acid substitution as a model reaction. Substitution of phenylalanine in a microreaction system using separate solutions was more efficient than in a batchwise reaction or in microchannel reaction using a homogeneous solution. Substitution of other amino acids showed that this enhancement is caused by localization of hydrophobic amino acids at the DMF–H2O interface. Using the rapid Michael addition reaction of the SH group of cysteine to a maleimide group, we also demonstrated that such a reaction involving hydrophilic amino acids was diminished in this microreaction system. These results show that the microreaction system is a novel apparatus for regulating chemical reactions, depending on the structure of the reactant molecules, by controlling the mixing of two different solutions.