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J R Hollingsworth

Publications and source records attributed to J R Hollingsworth.

10 recordsLinked to original sources
PubMed1985

Differences between voluntary and public organizations: the behavior of hospitals in England and Wales.

This study confronts the following questions: what are the conditions under which a society decides to do things in the public and voluntary nonprofit sectors, and in what ways do organizations behave differently, depending on whether they are in the public or the voluntary nonprofit sector? To address these questions, the study focuses on English and Welsh hospitals during the twentieth century but prior to the National Health Service. The study argues that as long as the sources of funding for public and voluntary organizations diverge, their behavior will diverge. Because English and Welsh voluntary hospitals prior to the National Health Service were heavily dependent on the voluntary sector for funding and the public hospitals were primarily dependent on the public sector for their funding, the data set is especially valuable for observing how divergent sources of funding influence the behavior of organizations.

England↗
PubMed1976

Facilitated transport of prostaglandins across the blood-cerebrospinal fluid and blood-brain barriers.

1. Ventriculo-cisternal perfusions were performed on rabbits with artificial cerebrospinal fluid containing blue dextran and tritium-labelled prostaglandin F(2alpha) ([(3)H]PGF(2alpha)). In order to study the nature of prostaglandin (PG) transfer across the blood-brain barrier, high concentrations of PGF(2alpha) or potential PG transport inhibitors were added to the perfusion fluid after the normal rate of [(3)H]PGF(2alpha) clearance was established.2. The [(3)H]PGF(2alpha) clearance was inhibited by 10(-6) to 10(-3)M PGF(2alpha), PGF(2beta), probenecid, iodipamide or bromcresol green but not by perchlorate.3. The (3)H content of the brain, relative to the (3)H-activity in the ventricular system, was also increased by high concentrations of PGF(2alpha), iodipamide or bromcresol green.4. It is concluded that the removal of PGs from the extracellular fluids of the brain is mediated by saturable, facilitated transport processes across both the choroidal and extrachoroidal regions of the blood-brain barrier system. In the case of the mammalian brain, such facilitated PG transport appears to be the primary mechanism for the termination of the action of these potent, endogenously produced autacoids.

Journal Article↗
PubMed1975

Further studies on the difference between ventricular and subarachnoid perfusion.

In order to study the exchanges between the subarachnoid fluid and the adjacent cortical tissue independently of the choroid plexus, artificial cerebrospinal fluid (CSF) was perfused from the supracallosal cistern to the cisterna magna in the rabbit. Test substances were introduced into the blood and held at a constant level. The degree of penetration by the blood-borne test substances into the artificial CSF perfused into the cortical subarachnoid space was noted. The degree of penetration of these test substances into the artificial CSF does not solely reflect rates of exchange between this fluid and the exposed cortex for it was shown histologically as well as physiologically that the artificial CSF does not remain in the subarachnoid space but also enters the subdural space to exchange with the blood via the dural capillaries. Thus this experimental model routinely produces an artefactual situation which restricts its use in the study of CSF-brain relations.

Animals↗
PubMed1973

Active transport of 131-I across the blood-brain barrier.

The ventricular space of rabbits was perfused with a low-viscosity silicone oil for the purpose of (1) collecting freshly secreted cerebrospinal fluid (c.s.f.) uninfluenced by diffusional exchanges with the brain and (2) studying passage of solutes from the blood into the brain, uncomplicated by exchanges with c.s.f. The freshly secreted c.s.f. appeared as fine droplets suspended in the less dense silicone, and accumulated at the bottom of the collected silicone. Studies on the penetration of (24)Na from blood into this fluid indicated that considerable exchanges with the brain had occurred between its secretion and collection, in spite of this method of collection. The second objective was attained, in that the exchanges between the freshly secreted fluid and the brain were quantitatively insufficient to affect the measure of kinetics of uptake by brain from the blood. In consequence, it was possible to demonstrate unequivocally that the increased uptake by brain of (131)I, when treated with perchlorate, was due to inhibition of an active process occurring across the blood-brain barrier. Other studies, involving ventriculo-cisternal perfusion with artificial c.s.f., lent further support to this concept. (131)I distribution is some 32% of the brain weight, a figure close to the ;chloride-space'.

Animals↗