Presence of Streptococcus anginosus DNA in esophageal cancer, dysplasia of esophagus, and gastric cancer

We recently reported cloning of Streptococcus anginosus (S. anginosus) DNA fragments containing the 16S ribosomal gene from DNA samples of surgical specimens of gastric cancers. To investigate the specificity of S. anginosus infection, Southern blot analysis with S. anginosus 16S ribosomal DNA probe and PCR analysis with S. anginosus-specific primers were performed in DNA samples prepared from 15 esophageal cancers, 43 gastric cancers, 16 lung cancers, 10 cervical cancers, 14 renal cell carcinomas, 10 colorectal cancers, and 19 bladder cancers. We frequently found S. anginosus DNA sequences in DNA samples from esophageal cancer and gastric cancer tissues, as well as in those from dysplasia of the esophagus of esophageal cancer patients. No S. anginosus DNA bands were detected by Southern blot analysis on DNAs from the noncancerous portions of the esophagus or the stomach. By PCR analysis with 35 cycles, only 7% of the noncancerous portion of the esophagus was shown to contain S. anginosus sequences. No S. anginosus sequences were found in DNAs from cancers in lung, cervix, and kidney, but they were found in 1 of 10 colon cancers.     

Cloning and sequence analysis of a cDNA encoding salmon (Onchorhynchus keta) liver transglutaminase

We isolated cDNA clones encoding a transglutaminase (TGase: EC 2.3.2.13) from a salmon (Onchorhynchus keta) cDNA library prepared from the liver. In the cDNA sequence combined, an open reading frame coding for a protein of 680 aa was found. The deduced sequence showed a considerable similarity (62.4%) to that of red sea bream TGase. By comparison of sequence similarity to other TGases, the structure of salmon TGase was like tissue type TGases, rather than membrane-associated type or plasma type TGases. As a structural feature of salmon TGase, 3 aa residues were substituted in the 25 aa sequence around the active site Cys residue, which is conserved among several tissue type TGases. The critical residues thought to form the catalytic-center triad (Cys272, His331, and Asp301) were found in the highly conserved region, but the region surrounding Tyr511, which corresponds to the residue participates in hydrogen-bond interactions of active center domain, was less similar to other TGases, except for red sea bream TGase. These finding suggests that the overall structure of fish TGase resembles tissue-type TGases, but has some unique structure.     

Synthesis of DHPA analogs and their inhibitory activities of human recombinant S-adenosyl-L-homocysteine hydrolase

We report syntheses of DHPA analogs, e.g., 9-(3-formyl-2,3-dihydroxypropyl)adenine (FDHPA) and 9-(3-formyl-2,3-dihydroxypropyl)hypoxanthine (FDHPI). Among these DHPA analogs, FDHPA behaved as an irreversible inactivator of human recombinant SAH hydrolase.     

Immunohistochemical detection of estrogen and progesterone receptors in spermatozoa of infertile men

OBJECTIVE: To evaluate the clinical implication of sex steroidal actions on human spermatozoa. PATIENTS AND METHODS: Human spermatozoa were obtained from 20 males. Immunohistochemical staining for estrogen receptors (ER) and progesterone receptors (PR) was conducted by the avidin-biotin-peroxidase complex method. RESULTS: Positive immunohistochemical staining of ER and PR was observed in all 8 cases of fertile couples. From infertile couples, ER were detected in 8/12 cases, including 3 with normozoospermia, 2 with oligozoospermia, 1 with asthenozoospermia, and 2 with teratozoospermia, but not in 4/12 cases, 1 with normozoospermia, 1 with asthenozoospermia, and 2 with oligoasthenozoospermia. PR were undetectable in all cases of negative ER and in 1 case (normozoospermial) of positive ER. CONCLUSION: Negative ER and/or PR in spermatozoa from infertile couples might be involved in cases of male infertility.     

A 100-channel optical FDM transmission/distribution at 622 Mb/sover 50 km

A 100-channel optical frequency-division multiplexing (FDM) transmission/distribution experiment at 622 Mb/s is demonstrated for a fiber length of 50 km. The feasibility of a polarization-insensitive waveguide frequency selection switch for 10-GHz intervals and a frequency-shift-keying (FSK) direct-detection scheme employing a Mach-Zehnder filter is verified. The demodulation circuit employs a Mach-Zehnder filter and a balanced receiver, which utilizes optical power more efficiently than the Fabry-Perot filter. No receiver sensitivity degradation is observed due to interchannel crosstalk of the 128-channel tunable waveguide frequency selection switch (FS-SW) or fiber four-wave mixing for transmissions over a 50-km-long nondispersion-shifted (NDS) fiber and a 26-km-long dispersion-shifted (DS) fiber     

Developmental changes in the effect of acidosis on contraction, intracellular pH, and calcium in the rabbit mesenteric small artery

The purpose of the present study was to determine developmental changes in the effect of respiratory acidosis on vascular smooth muscle contraction. Vessel diameter, intracellular pH (pHi), and calcium concentration ([Ca]i) were measured in a cannulated preparation of the small mesenteric artery of newborn and adult rabbits. In the artery precontracted by high KCl, acidosis caused a vasorelaxation both in the newborn and the adult; the vasorelaxation was greater in the newborn than in the adult. The fura-2 fluorescence ratio, an indicator of [Ca]i, decreased transiently during acidosis and the decrease was similar in the two age groups. In the artery precontracted by norepinephrine, acidosis caused a transient vasoconstriction in the adult and a vasorelaxation in the newborn. In these vessels, the fura-2 fluorescence ratio increased transiently during acidosis; the increase was similar in the two groups. Upon induction of acidosis, pHi fell rapidly in the artery precontracted by norepinephrine or high KCl, and the depression of pHi was similar in the two groups. In the skinned smooth muscle preparation, a tension-[Ca] relationship curve at pH 7.1 was not significantly different from that at pH 6.8 in the adult. In the newborn, the tension-[Ca] curve at pH 6.8 was shifted to the right, compared with that at pH 7.1. These data suggest that the vasorelaxant effect of respiratory acidosis in the premature vessel is greater than in the adult. The greater vasorelaxation in the newborn cannot be explained by the age-related difference in pHi or [Ca]i during acidosis. The greater sensitivity of myofibrils to low pHi in the newborn may, at least in part, be responsible for the greater vasorelaxation in this age group.     

Characteristics of muscular contraction caused by magnetic stimulation

Characteristics of muscular contraction induced by magnetic stimulation were studied using isolated gastrocnemius muscles of a frog. The figure-eight coil position was regarded as 0 degrees when the direction of induced current was parallel to the muscle fiber axis, and 90 degrees when the induced current was perpendicular to the muscle fiber axis. Muscular contraction readily occurred with lower outputs of magnetic stimulation at 0 degrees and 180 degrees, but it was weak at 90 degrees and 270 degrees. Magnetic stimulation did not directly induce muscular contraction but it acted on the synapses forming end plates to muscle cells, and muscular contraction occurred if the direction of the eddy current was parallel to the nerve which innervated the muscle cells.     

The lubricating ability of biomembrane models with dipalmitoyl phosphatidylcholine and gamma-globulin

This paper describes the process of involving health professions students in research in rural primary care and how their research has contributed to the development and expansion of a rural community health center. Since 1978 over 400 students have completed rotations at the center, and more than 200 have been health profession students, including medical, nursing, physician assistant, pharmacy, and health administration students. A total of 96 research projects were completed. These projects lie in two main areas: medical services and community outreach. Those related to medical services include measures of access to care, quality of care audits, clinical guideline development, practice patterns, prevalence studies, and qualitative research. Projects focusing on community outreach include community surveys, screening follow-ups, program evaluation, and program development. Principles that guide the selection and conduct of research projects include: Projects should be directly related to important work of the practice and reflect an interest of the student; projects are structured to include some or all of the following: literature search, data analysis, a visual display of quantitative information (table or graph), and application of relevant statistical tools; the student has a project supervisor; the student is a participant rather than an independent investigator; and a research flow sheet is used to orient students and NRHA staff to the larger research effort. Students are expected to present results, conclusions and recommendations to an appropriate group. Student research has made a significant contribution to both practice activities and practice policies.