Biomedical subjects
Publications and source records attributed to D M Norris.
A new device is described which enhances the treatment of impacted stones in association with the extracorporeal shock-wave lithotripsy. This technique may result in decreased number of shocks and increased efficiency, as well as, enhance outpatient treatment.
We present the initial results of a ureteral stone brush used in conjunction with extracorporeal shock wave lithotripsy for impacted ureteral stones. We studied 31 cases of ureteral calculi that could not be manipulated back into the renal collecting system. In 18 cases a ureteral catheter was placed past the calculus, while in 13 a catheter could not be passed. With the stone brush unbypassed stones yielded a success rate similar to that for bypassed stones (84.6 versus 88.9%, respectively). We believe that this result is due to the ability of the stone brush to remove circumferential fragments from around the stone, allowing more shock energy to reach the core of the stone.
We describe 3 patients with ureteral calculi who failed multiple extracorporeal shock wave lithotripsy treatments and whose stones could not be visualized by ureteroscopy despite radiological confirmation. We contend that these ureteral stones migrated submucosally and are refractory to the aforementioned treatment modalities. Each patient had a common presenting complaint of intermittent flank pain 5 years in duration, leading us to believe that long-standing stone impaction is a prerequisite for this entity. Our experience is reviewed.
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A new variation on the Water-Pik technique for treating steinstrasse after extracorporeal shock-wave lithotripsy is described. This technique is simple and effective and can be adapted for use in virtually any standard cystoscopy suite.
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We present our experience with the C-arm image intensifier in the localization of renal calculi. We have found this technique to be exceptionally easy to use and extraordinarily efficient. However, unless the disk images are used primarily, rather than continuous fluoroscopy, the radiation exposure can be significant. This technique can be somewhat limiting in that exceptionally small stones or poorly opacified stones cannot be picked up easily.
A description of the external morphogenesis of male and female embryos of X. ferrugineus, derived from in vivo observation, is presented here. The embryogenesis of this beetle is typical of the Coleoptera, and is also similar in most respects to the generalized insect plan. Observed unusual aspects of X. ferrugineus embryogenesis include the precocious formation of primordial g/rm cells and their temporary exclusion from somatic blastoderm; the precocious in situ delineation of gnathal metameres, the closing of the gastral groove beginning at both ends and proceeding towards its middle, the formation of several paired lateral amnio-serosal folds, the formation of cellular processes between the amnion and serosa, and the absorption of the thoracic limbs to produce an apodous larva. The embryonic developmental picture provided here, and the previously established means of rearing X. ferrugineus in controlled laboratory culture jointly provide a promising basis for the further use of this insect in developmental studies.
The developmental rates of male and female embryos of Xyleborus ferrugineus were compared by charting for each sex the mean age for each of ten discrete morphological stages of embryogenesis from pole cell exclusion to eclosion male and female embryos developed synchronously from stage 1 (which begins with pole cell exclusion) through stage 4 (which ends with the completion of germ band extension and metamerization). After stage 4 and throughout the remainder of embryogenesis, the mean ages per morphological stage of male embryos were significantly greater than those for female embryos. The expected physiological consequences of a haploid genome in the male embryo as compared to a diploid condition in the female embryo are discussed as the possible basis for the persistent lag observed in male developmental rate after stage 4.
The compound eye of male (haploid) Xyleborus ferrugineus beetles was examined with scanning and transmission electron microscopy. The eye externally consists of ca. 19 to 33 facets. Each ommatidium is composed of a thickly biconvex lenslet with about 50 electron dense and rare layers, but at the junction area between two lenslets there are only about 35 to 37 layers that can be distinguished. A very short (3.4-4.0 mum) acone type crystalline cone is located directly beneath the lenslet. Each ommatidium is surrounded by pigment cells, and pigment granules also appear throughout the cytoplasm of the retinular cells. Some pigment granules are even present below the basement membrane. there are 8 retinular cells. The rhabdomeres of 2 centrally situated photoreceptor cells fuse into a rhabdom which is enveloped by the rhabdomeres of 6 peripheral retinular cells. The rhabdomeres of the 6 peripheral retinular cells join laterally to form a rhabdomeric ring around the central rhabdom. No tracheation was observed among the retinular cells. Virus-like particles are evident near the nucleus in each Semper cell of the crystalline cone.
The compound eye of female (diploid) Xyleborus ferrugineus beetles was examined with scanning and transmission electron microscopy. The eye is emarginate, and externally consists of roughly 70-100 facets. Each ommatidium is composed of a thickly biconvex lenslet with about 50 electron dense and rare layers. The lens facet overlies a crystalline cone of the acone type which is roughly hourglass-shaped. Pigment cells envelop the entire ommatidium, and pigment granules also are abundant throughout the cytoplasm of the 8 retinular cells. The rhabdomeres of 2 centrally situated photoreceptor cells effectively fuse into a rhabdom that extends from the base of the crystalline cone deeply into the ommatidium. Six distal peripheral retinular cells encircle the 2 central cells, and their rhabdomeres join laterally to form a rhabdomeric ring around the central rhabdom. The rhabdom and rhabdomeric ring are effectively separated by the cytoplasm of the two central retinular cells which contains the usual organelles and an abundance of shielding pigment granules. Eight axons per ommatidium gather in a tracheae-less fascicle before exiting the eye through the fenestrate basement membrane. No tracheation was observed among the retinular cells. Each Semper cell of each observed crystalline cone contained an abundance of virus-like particles near the cell nucleus. The insect is laboratory reared, and the visual system seems very amenable to photoreceptor investigations.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.