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N Fowler

Publications and source records attributed to N Fowler.

33 records · Page 2Linked to original sources
PubMed1978

Effects of potassium depletion on renal tubular chloride transport in the rat.

Potassium depletion (KD) causes renal chloride-wasting. To investigate the effects of KD on renal tubular reabsorption of chloride, balance, clearance, micropuncture, and microinjection studies were performed on potassium-depleted rats. KD was produced by omitting potassium from the diet and by administration of DOCA on days 2 and 3; rats were studied on days 9 to 12. Diets were chloride-free in both control and KD groups. In the KD group, balance experiments confirmed greater chloride depletion and continued chloride-wasting, and clearance studies showed an increased FECl. Muscle potassium was reduced by 27% as compared to control. Whole kidney and single nephron GFR were reduced in KD rats to 72 and 74% of control. Fractional (6 +/- 6% vs. 22 +/- 4%, P less than 0.05) and absolute chloride reabsorption in the proximal tubule was not different. Fractional reabsorption of delivered chloride was reduced in the loop of Henle (92 +/- 0.8% in KD vs. 95 +/- 0.7% in control, P less than 0.02). Transtubular chloride ratio (0.28 +/- 0.02 vs. 0.21 +/- 0.02, P less than 0.02) was increased at the early distal tubule. Fractional delivery of chloride (8 +/- 0.9 vs. 5 +/- 0.5%, P less than 0.02), and fluid (26 +/- 1 vs. 22 +/- 1%, P less than 0.05) were also increased in KD at the early distal tubule. Recovery of chloride 36 injected into late distal tubules was 88 +/- 1% on a normal chloride intake, 62 +/- 2% in chloride depletion, and 88 +/- 2% in potassium and chloride depletion. Thus, KD depresses chloride reabsorption in the proximal tubule and in the loop of Henle, and it decreases chloride 36 efflux from the collecting duct.

Animals↗
PubMed1977

Effect of hypertonic urea and mannitol on distal nephron permeability.

The paracellular pathway permeability is known to increase in perfused amphibian kidneys if the luminal fluid is made hyperosmotic with mannitol or urea. To investigate whether luminal hypertonicity increases paracellular pathway permeability in the mammalian nephron, early rat distal tubules were micropunctured and perfused through one micropipette with either isosmotic saline (IS), hyperosmotic urea (HU) or hyperosmotic mannitol (HM) solutions. A second micropipette was placed down-stream in the same tubule and test solutions of 30 nl of a mixture of 14C-inulin and 3H-mannitol or of 3H-inulin and 14C-urea were injected. Similar intratubular injections of tracers were performed in a second group of rats undergoing diuresis induced either by infusing intravenously saline alone (VS) or receiving saline plus 0.4 M urea (VU). In the latter group (VU) luminal urea concentration was increased without the tubular lumen being made hyperosmotic to its peritubular fluid. Urinary unulin recovery was essentially complete and unaffected by experimental procedures. Difference between mannitol recoveries in isosmotic saline and hyperosmotic urea perfusions IS-HU was 2.6 +/- 0.8% (P less than 0.001). Difference in urea recoveries IS-HM was 4.1 +/- 5.1% (P greater than 0.40), IS-HU was 13.9 +/- 5.3% (P equal to 0.015) and, VS-VU equal to 17.0 +/- 3.4 (P less than 0.001). Therefore, elevated luminal urea concentration increased tracer mannitol and also tracer urea permeability, both in the presence and absence of tubular hyperosmolarity. Electron microscopic observations showed changes in geometry of tubular junctional complexes compatible with the observed increase in permeability.

Animals↗
PubMed1975

Distal tubular tracer microinjection study of renal tubular potassium transport.

Renal tubular potassium (K) transfer was studied in rats using a tracer microinjection technique in which [14C]inulin and 42K were simultaneously injected into early distal tubules during osmotic diuresis. Experiments were carried out in 1) animals on a control diet, 2) animals in which K secretion had been stimulated (high-K diet + KC1, Na2SO4, Diamox infusions), and 3) animals in which K excretion had been reduced by a low-K or low-Na diet or by amiloride. 42K excretion into the urine coincided closely in time with the excretion pattern of [14C]inulin. Efflux of 42K out of the lumen was stimulated during reduced K secretion along the distal nephron and decreased during enhanced K secretion when small tubular K loads were given. These experiments demonstrate bidirectional K movement across the distal nephron and show that changes in reabsorptive K efflux participate in the regulation of tubular net K movement.

Amiloride↗
PubMedDate not supplied

A statistical analysis of the classification of depression in a mixed community and clinical sample.

Depressive symptoms in three samples are assessed using grade-of-membership analysis to clarify the distribution of depressive symptoms across traditional affective diagnoses. The technique is used to examine whether depressive symptoms and symptoms frequently associated with depressive disorders cluster into recognizable syndromes or pure types that parallel current operational diagnoses. Three hundred and ninety subjects were studied to address the question: among a mixed population with a range of depressive symptoms, will syndromes resembling endogenous depression and demoralization emerge from the range of presentation of depressive symptoms? A single pure type is nearly identical to the DSM-III classification of major depression with melancholia. No such pure type emerged that resembled demoralization.

Adult↗
PubMedDate not supplied

Corporate compliance: framework and implementation.

The federal government has created numerous programs to combat fraud and abuse. The government now encourages healthcare facilities to have a corporate compliance program (CCP), a plan that reduces the chances that the facility will violate laws or regulations. A CCP is an organization-wide program comprised of a code of conduct and written policies, internal monitoring and auditing standards, employee training, feedback mechanisms and other features, all designed to prevent and detect violations of governmental laws, regulations and policies. It is a system or method ensuring that employees understand and will comply with laws that apply to what they do every day. Seven factors, based on federal sentencing guidelines, provide the framework for developing a CCP. First, a facility must establish rules that are reasonably capable of reducing criminal conduct. Second, high-level personnel must oversee the compliance effort. Third, a facility must use due care in delegating authority in the compliance initiative. Fourth, standards must be communicated effectively to employees, and fifth, a facility must take reasonable steps to achieve compliance. Sixth, standards must be enforced consistently across the organization and last, standards must be modified or changed for reported concerns, to ensure they are not repeated. PROMINA Health System, Inc. in Atlanta, Ga., designed a program to meet federal guidelines. It started with a self-assessment to define its areas or risk. Next, it created the internal structure and assigned organizational responsibility for running the CCP. PROMINA then developed standards of business and professional conduct, established vehicles of communication and trained employees on the standards. Finally, it continues to develop evidence of the program's effectiveness by monitoring and documenting its compliance activities.

Ethics, Institutional↗
PubMedDate not supplied

A bitter pill.

Explore the source record for details and available documents.

Drug Prescriptions↗