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Biomedical subjects

G M Watson

Publications and source records attributed to G M Watson.

64 records · Page 4Linked to original sources
PubMed1983

Comparative ultrastructure of catch tentacles and feeding tentacles in the sea anemone Haliplanella.

TEM observations of catch tentacles revealed that the tentacle tip epidermis is filled with two size classes of mature holotrich nematocysts and a gland cell filled with electron-dense vesicles. Vesicle production is restricted to upper-middle and tentacle tip regions, whereas holotrich development occurs in the lower-middle and tentacle base regions. Thus, catch tentacles have a maturity gradient along their length, with mature tissues concentrated at the tentacle tip. Occasional feeding tentacle cnidae (microbasic p-mastigophores and basitrichs) and mucus gland cells occur in proximal portions of catch tentacles, but are phagocytized by amoeboid granulocytes and transported to the gastrodermis for further degradation. No feeding tentacle cnidae or mucus cells occur distally in catch tentacles. Unlike catch tentacles, feeding tentacles are homogeneous in structure along their length with enidocytes containing mature spirocysts, microbasic p-mastigophore or basitrich nematocysts distributed along the epithelial surface. Cnidoblasts are recessed beneath cnidocytes, occurring along the nerve plexus. Mucus gland cells and gland cells filled with electron-dense vesicles are present in feeding tentacles, distributed at the epithelial surface. Granular phagocytes are rare in the feeding tentacle tip, but common in the tentacle base.

Animals↗
PubMed1983

Laser fragmentation of renal calculi.

Pulsed Nd YAG lasers will fragment all types of urinary calculi rapidly in air. The fragments are much smaller than with any other technique. Large stones can be split into a few discrete fragments which may prove to be an advantage in that the fragments could then be extracted without leaving multiple small fragments behind. Certain pulsed lasers can be transmitted through fine, flexible glass fibres which are small enough to pass through any sized instrument channel. There is therefore an immediate possibility of using this type of laser in the bladder with carbon dioxide instead of an irrigant. Further experiments are planned in order to investigate the possibility of using this mode of laser in the kidney percutaneously.

Endoscopy↗
PubMed1983

Transurethral ureteroscopic retrieval of ureteric stones.

This report documents our initial experience in the transurethral retrieval of ureteric stones using the rigid ureteroscope. Ten patients are included. Half of the stones were located in the lower one-third of the ureter and half in the upper two-thirds. They varied in size from 5 to 10 mm in diameter. Seven were successfully extracted at the first attempt using stone baskets under direct vision. Of the remaining 3, one was retrieved at a second ureteroscopy, one was fragmented and subsequently passed and one required percutaneous nephroscopy for its removal from the renal pelvis. It is concluded that transurethral ureteroscopy offers a safe alternative to both open ureterolithotomy and blind manipulation.

Adult↗
PubMed1983

Op-Site skin closure: a comparison with subcuticular and interrupted sutures.

Op-Site skin closure was compared with two standard techniques of wound closure, interrupted silk sutures and subcuticular nylon. The Op-Site skin closure allowed freer drainage of secretions from the wound and the incidence of erythema and tenderness was significantly lower. However, there was a greater tendency for the wound edges to slip out of alignment or invert.

Erythema↗
PubMedDate not supplied

Detecting a field gradient of PAH exposure in decapod crustacea using a novel urinary biomarker.

Norwegian coastal waters are subject to PAH contamination from electrochemical industries such as aluminium smelters. Evidence of PAH exposure has been established in fish and bivalves. The present study tests the applicability of a novel crustacean PAH exposure biomarker to a PAH contamination gradient in the field (Karmsund Strait, SW Norway). Fluorescence analysis of urine samples collected from crabs at each site revealed 1-OH pyrene "equivalent" levels (indicative of pyrogenic PAH contamination) decreased with increasing distance from a point source of pyrogenic PAH (a large aluminium works). The assay was shown to be suitable for the detection of PAH exposure in wild crustacean populations, for discriminating between contaminated and clean sites and is also sufficiently sensitive to detect gradients of PAH contamination. The method provides a rapid, inexpensive and non-destructive measure of biologically available PAH in crustaceans.

Animals↗
PubMedDate not supplied

A non-destructive assessment of the exposure of crabs to PAH using ELISA analyses of their urine and haemolymph.

Urine and haemolymph can be repeatedly sampled from crabs with no (or limited) damage to the organism. Their analysis offers a measure of the animals' exposure to biologically available contaminants. Shore crabs (Carcinus maenas) were exposed to the PAHs phenanthrene and pyrene at concentrations ranging from 20 to 200 microg l(-1). After 48 h, urine and haemolymph samples were taken and analysed using ELISA and UV-fluorescence spectrophotometry. High correlations were recorded between the two sets of results from the urine analyses (r2 = 0.83 for phenanthrene and r2 = 0.88 for pyrene). Contaminant concentrations were much lower in haemolymph than in the urine. Analyses of urine taken from crabs collected from clean and contaminated sites confirm the suitability of these analyses for environmentally exposed organisms. Again, a good correlation was recorded between the ELISA and spectrofluorimetric analysis (r2 = 0.83). In this instance, difficulties were experienced with haemolymph analyses owing to a lack of sensitivity.

Animals↗