Evaluation Of Present Day Treatment Of Peptic Ulcer

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111139/1/j.1532-5415.1953.tb01110.x.pd

Differential response to various stimulants in the body and antrum of the canine stomach

This study was initiated to evaluate gastric motility with the use of extraluminal force transducers in unanesthetized dogs. The contractile activity of the circular and longitudinal muscle in both antrum and body of the canine stomach was monitored in the interdigestive state and under the influence of food, acetylcholine, and 5-hydroxytryptophane. The latter two chemicals were infused for a 30-min. period. Each of the two muscle layers in antrum and body had a maximum frequency of 5 contractions per minute. This activity was continuous during 30 min. only under the influence of food and 5-hydroxytryptophane. Acetylcholine stimulant effects did not persist beyond the initial 10 min. of infusion. Amplitude of contractions under spontaneous or induced activity varied. The height of these contractions were circular antrum > longitudinal antrum > circular body > longitudinal body. This method of recording muscle contractility is believed to be useful for quantitatively assaying gastric activity without compromise of physiologic environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44365/1/10620_2005_Article_BF02232956.pd

Therapeutic trial of silicone in peptic ulcer

In a controlled double-blind trial of the therapeutic effectiveness of silicone in patients with duodenal ulcer, the silicone tested was shown to be slightly less effective than placebo medication. The relatively good early response of chronically recurring ulcer disease appeared to be due to the emotional impact of “a new treatment of ulcers.”Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44434/1/10620_2005_Article_BF02232021.pd

Silicones in experimental peptic ulceration

In the search for a silicone as uniformly successful as the one used earlier, in preventing and treating experimental peptic ulceration in animals, 30 different silicones were used in pylorus-ligated rats, Mann-Williamson dogs and histamine ulcerated dogs. None were found to be uniformly effective and the initial encouraging results reported by us could not be reproduced with subsequent silicone preparations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44435/1/10620_2005_Article_BF02232022.pd

Superhumps in Cataclysmic Binaries. XXIII. V442 Ophiuchi and RX J1643.7+3402

We report the results of long observing campaigns on two novalike variables: V442 Ophiuchi and RX J1643.7+3402. These stars have high-excitation spectra, complex line profiles signifying mass loss at particular orbital phases, and similar orbital periods (respectively 0.12433 and 0.12056 d). They are well-credentialed members of the SW Sex class of cataclysmic variables. Their light curves are also quite complex. V442 Oph shows periodic signals with periods of 0.12090(8) and 4.37(15) days, and RX J1643.7+3402 shows similar signals at 0.11696(8) d and 4.05(12) d. We interpret these short and long periods respectively as a "negative superhump" and the wobble period of the accretion disk. The superhump could then possibly arise from the heating of the secondary (and structures fixed in the orbital frame) by inner-disk radiation, which reaches the secondary relatively unimpeded since the disk is not coplanar. At higher frequencies, both stars show another type of variability: quasi-periodic oscillations (QPOs) with a period near 1000 seconds. Underlying these strong signals of low stability may be weak signals of higher stability. Similar QPOs, and negative superhumps, are quite common features in SW Sex stars. Both can in principle be explained by ascribing strong magnetism to the white dwarf member of the binary; and we suggest that SW Sex stars are borderline AM Herculis binaries, usually drowned by a high accretion rate. This would provide an ancestor channel for AM Hers, whose origin is still mysterious.Comment: PDF, 41 pages, 4 tables, 16 figures; accepted, in press, to appear December 2002, PASP; more info at http://cba.phys.columbia.edu

Superhumps in Cataclysmic Binaries. XXV. q_crit, epsilon(q), and Mass-Radius

We report on successes and failures in searching for positive superhumps in cataclysmic variables, and show the superhumping fraction as a function of orbital period. Basically, all short-period systems do, all long-period systems don't, and a 50% success rate is found at P_orb=3.1+-0.2 hr. We can use this to measure the critical mass ratio for the creation of superhumps. With a mass-radius relation appropriate for cataclysmic variables, and an assumed mean white-dwarf mass of 0.75 M_sol, we find a mass ratio q_crit=0.35+-0.02. We also report superhump studies of several stars of independently known mass ratio: OU Virginis, XZ Eridani, UU Aquarii, and KV UMa (= XTE J1118+480). The latter two are of special interest, because they represent the most extreme mass ratios for which accurate superhump measurements have been made. We use these to improve the epsilon(q) calibration, by which we can infer the elusive q from the easy-to-measure epsilon (the fractional period excess of P_superhump over P_orb). This relation allows mass and radius estimates for the secondary star in any CV showing superhumps. The consequent mass-radius law shows an apparent discontinuity in radius near 0.2 M_sol, as predicted by the disrupted magnetic braking model for the 2.1-2.7 hour period gap. This is effectively the "empirical main sequence" for CV secondaries.Comment: PDF, 45 pages, 9 tables, 12 figures; accepted, in press, to appear November 2005, PASP; more info at http://cba.phys.columbia.edu

Cellular location and activity of Escherichia coli RecG proteins shed light on the function of its structurally unresolved C-terminus

RecG is a DNA translocase encoded by most species of bacteria. The Escherichia coli protein targets branched DNA substrates and drives the unwinding and rewinding of DNA strands. Its ability to remodel replication forks and to genetically interact with PriA protein have led to the idea that it plays an important role in securing faithful genome duplication. Here we report that RecG co-localises with sites of DNA replication and identify conserved arginine and tryptophan residues near its C-terminus that are needed for this localisation. We establish that the extreme C-terminus, which is not resolved in the crystal structure, is vital for DNA unwinding but not for DNA binding. Substituting an alanine for a highly conserved tyrosine near the very end results in a substantial reduction in the ability to unwind replication fork and Holliday junction structures but has no effect on substrate affinity. Deleting or substituting the terminal alanine causes an even greater reduction in unwinding activity, which is somewhat surprising as this residue is not uniformly present in closely related RecG proteins. More significantly, the extreme C-terminal mutations have little effect on localisation. Mutations that do prevent localisation result in only a slight reduction in the capacity for DNA repair. © 2014 The Author(s)

A simplified multiple-retrieving small-bowel biopsy tube

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44440/1/10620_2005_Article_BF02231909.pd