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J Harding

Publications and source records attributed to J Harding.

79 records · Page 5Linked to original sources
PubMed1977

Denervation in the primary olfactory pathway of mice. IV. Biochemical and morphological evidence for neuronal replacement following nerve section.

Unilateral olfactory nerve section was performed in the mouse. Three biochemical markers of the olfactory chemoreceptor neurons: carnosine, carnosine synthetase activity and the olfactory marker protein, were measured in the olfactory bulb and epithelium. Parallel observations were made by light microscopy as well as at the ultrastructural level. The specific biochemical markers decrease rapidly in both bulb and epithelium and reach a minimum by the end of the first week after surgery. They then slowly return to 80% of control values by one month. Carnosinase activity in epithelium was essentially unaffected. These biochemical observations coincide temporally with the onset of degenerative changes seen morphologically, in both the bulb and epithelium. The degenerative changes persist for up to two weeks in the bulb and for about one week in the epithelium. At this time basal cell division and differentiation begins in the epithelium with subsequent regrowth of olfactory axons into the glomerular layer of the olfactory bulb with ther reappearance of olfactory axon terminals. The temporal coincidence of these biochemical and morphological observations suggests they are manifestations of the same process, and is consistent with the idea that the olfactory chemoreceptor neurons are perhaps unique in being able to be replaced from undifferentiated stem cells.

Animals↗
PubMed1976

Denervation in the primary olfactory pathway of mice. III. Effect on enzymes of carnosine metabolism.

Carnosine (beta-Ala-L-His) is localized within the receptor neurons of the primary olfactory system. Carnosine synthetase, the enzyme responsible for its synthesis, is found in the primary olfactory pathway of the mouse at activities higher than that found in other body tissues and brain regions. Carnosinase, the degradative enzyme, is present at high activities, only in the olfactory epithelial portion of this pathway. Peripheral deafferentation or central denervation cause a selective decrease in the activity of carnosine synthetase in the reciprocal portion of the primary olfactory system implying specific localization within the receptor neurons. These data are consistent with a role for the dipeptide carnosine in olfactory neural transmission.

Animals↗
PubMedDate not supplied

Percutaneous retrieval of a right atrioventricular embolus.

Percutaneous retrieval of a 12-cm-long serpiginous clot lodged in the right atrium and ventricle is reported. Following bilateral common femoral vein puncture, a Bird's Nest cava filter was first positioned ready to deploy immediately below the renal veins via the right femoral vein. From the left femoral vein, a Cook intravascular retrieval basket was advanced to the right atrium. Under transthoracic echocardiographic visualization, the basket was used to engage, trap, and gently withdraw the clot in a single long strand below the prepositioned inferior vena cava filter. The filter was immediately deployed, leaving the clot trapped inferior to the renal veins, in the cava and left iliac vein. The patient remained well and asymptomatic at discharge.

Aged↗
PubMedDate not supplied

Intrauterine feeding of the growth retarded fetus: can we help?

Intrauterine feeding of the growth retarded fetus appears an attractive therapeutic possibility. However the factors which determine the reversibility of intrauterine growth retardation are poorly understood. While fetal substrate supply is the final common pathway by which many factors restrict fetal growth, improving fetal substrate supply does not always lead to improved fetal growth. Similarly, fetal substrate supply is an important regulator of fetal endocrine status, such as circulating IGF-1 levels, but again, improving fetal substrate supply does not always alter fetal endocrine status or fetal growth. The relationship between substrate supply, endocrine status and growth is regulated in a complex way by placental function. Understanding the role of the placenta in this regulation is essential if in the future we are to help the growth retarded fetus.

Embryonic and Fetal Development↗
PubMedDate not supplied

Managing continuity of medical care.

A key consideration in decisions on allocation of work load in physician groups is preservation of continuity--so key, in fact, that the word continuity is often used as a holy incantation that implies any further argument is blasphemy. But what is continuity? If we can examine the concept along with its advantages and how it is achieved, health system planners on the micro level can design systems rationally incorporating continuity of medical care.

Ambulatory Care↗