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Biomedical subjects

D J Lewis

Publications and source records attributed to D J Lewis.

At least 109 records · Page 6Linked to original sources
PubMed1980

Distribution and ultrastructural characteristics of Feyrter cells in the rat and hamster airway epithelium.

Feyrter cells were found both singly and in groups at all levels of the respiratory tract studied in both rats and Syrian golden hamsters. Particularly large and prominent groups of Feyrter cells were present at bronchiolar bifurcations and bronchiolar-alveolar junctions. Single Feyrter cells were also found throughout the respiratory tract, but their distribution appeared entirely random. In all cases examined the groups of Feyrter cells were overlaid by intermediate and serous secretory epithelial cells. Occasionally small areas of the Feyrter cells were exposed to the airway lumen. Small canaliculi-like intercellular spaces were present between adjacent Feyrter cells. Single unmyelinated axons which contained neurotubules, mitochondria, and vesicles were occasionally seen in close association with Feyrter cells.

Animals↗
PubMed1980

The ultrastructure of rat laryngeal epithelia.

The histology and ultrastructure of the rat laryngeal epithelia are described. Five epithelial types were identified. Stratified squamous epithelium was found over most of the epiglottis, arytenoid projections and lateral ventricles. The vocal folds were covered by a low squamoid type of epithelium. Respiratory epithelium, similar to that found elsewhere in the respiratory tract, occupied all the mucosa caudal to the vocal folds, small areas at the base of the epiglottis and along the inner aspects of the arytenoid projections. Two forms of relatively unusual pseudostratified cuboidal epithelium were present in the ventrolateral aspect at the level of the arytenoid projections and within the ventral pouch. Non-myelinated, intro-epithelial nerve fibres were found throughout the larynx, and were abundant in areas at the base of the epiblottis covered by respiratory epithelium and to a lesser extent in the cuboidal epithelium of the ventral pouch. Globule leucocytes were frequently found within respiratory epithelium, less frequently in cuboidal epithelium and only rarely in squamous areas.

Animals↗
PubMed1979

Ultrastructure of rhesus monkey renomedullary interstitial cells.

The fine structure of rhesus monkey renomedullary interstitial cells was studied by electron microscopy. These stellate cells contained variable numbers of lipid droplets, moderate numbers of mitochondria, moderate amounts of rough endoplasmic reticulum, and prominent Golgi zones. In rare instances, apparent release of lipid droplets into the interstitium was observed. The most prominent feature of the interstitial cells was larger nuclear pseudoinclusions which were observed in a high proportion of the animals examined.

Animals↗
PubMed1979

Ecological studies at Hofuf, Eastern Saudi Arabia, in relation to dermal leishmaniasis.

Field and laboratory investigations were carried out in connection with an epidemic of dermal leishmaniasis in Hofuf, Eastern Province of Saudi Arabia, during 1977. In this present note emphasis is laid on description of the population dynamics and species spectrum of the sandflies, the occurrence of the vector and the course of the epidemic of Leishmania tropica in correlation with the sandfly population and the natural reservoir and the rodent population.

Animals↗
PubMed1977

Inhibition of fructose-1,6-bisphosphate aldolase from rabbit muscle and Bacillus stearothermophilus.

Phosphoglycollohydroxamic acid and phosphoglycollamide are inhibitors of rabbit muscle fructose-1,6-bisphosphate aldolase. The binding dissociation constants determined by enzyme inhibition and protein fluorescence quenching suggest that two distinct enzyme inhibitor complexes may be formed. The binding dissociation constants of the two inhibitors to Bacillus stearothermophilus cobalt (II) fructose-1,6-bisphosphate aldolase have also been determined. The hydroxamic acid is an exceptionally potent inhibitor (Ki = 1.2 nM) probably due to direct chelation with Co(II) at the active site. The inhibition, however, is time-dependant and the association and dissociation constants have been estimated. Ethyl phosphoglycollate irreversibly inhibits rabbit muscle fructose-1,6-bisphosphate aldolase in the presence of sodium borohydride, presumably by forming a stable secondary amine through the active-site lysine reside. A new condensation assay for fructose-1,6-bisphosphate aldolases has been developed which is more sensitive than currently used assay procedures.

Animals↗
PubMed1976

A cognitive approach to experimental amnesia.

A review of selected experiments indicates that not all examples of experimental amnesia are due to the failure of a memory to fixate. Briefly, the argument is that the fixation of a memory occurs within a very short time and that its retrieval is aided if it is coded into a contextual memory system. An amnesic agent serves to block (inhibit) memories rather than disrupt them and has its effects on active memories, whatever their age. In sum, the empirical retrograde amnesia gradient does not necessarily support traditional consolidation theory.

Amnesia↗