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Biomedical subjects

F A Davis

Publications and source records attributed to F A Davis.

At least 37 records · Page 2Linked to original sources
PubMed1990

Orally administered 4-aminopyridine improves clinical signs in multiple sclerosis.

4-Aminopyridine (4-AP), a potassium channel blocker, restores conduction in blocked, demyelinated animal nerve. Its administration to multiple sclerosis (MS) patients produces transient neurological improvements. Vision improves after either oral or intravenous administration, whereas motor function improvement has been reported only with the latter. To assess further its potential as a practical symptomatic treatment, we studied the efficacy of single, oral doses of 4-AP on both visual and motor signs in MS. Twenty temperature-sensitive male MS patients were given either 10 to 25 mg of 4-AP or identically appearing lactose placebo capsules. Static quantitative perimetry, critical flicker-fusion, visual acuity, visual evoked potentials, and videotaped neurological examinations were monitored. All of 15 MS patients given 4-AP mildly to markedly improved. Motor functions (power, coordination, gait) improved in 9 of 13 involved, vision in 11 of 13, and oculomotor functions in 1 of 2. Improvements developed gradually at doses as low as 10 mg, usually beginning within 60 minutes after drug administration, and reversed gradually over 4 to 7 hours. No serious adverse effects occurred. No significant changes were observed in 5 MS patients given placebo. We conclude that orally administered 4-AP produces clinically important improvements in multiple, chronic deficits in MS. Further studies are warranted to assess efficacy and safety of prolonged administration.

4-Aminopyridine↗
PubMed1988

Medicare hospice benefit: early program experiences.

In this article, an overview of the Medicare hospice benefit is presented and selected preliminary findings from the Medicare hospice benefit program evaluation are provided. By mid-1987, about one-half of all community home health agency-based hospices were Medicare certified, compared with about one-fifth of all independent/freestanding hospices and one-seventh of hospital and skilled nursing facility-based hospices. Medicare beneficiary election of the hospice benefit increased from about 2,000 beneficiaries in fiscal year 1984 to about 11,000 during fiscal year 1986. Medicare reimbursed hospices an average of $1,798, $2,078 and $2,337 per patient during fiscal years 1984, 1985, and 1986, respectively.

Certification↗
PubMed1987

Selective blockade of components of potassium activation in Myxicola axons.

The K+ conductance in Myxicola giant axons activates in two phases which are pharmacologically separable. The fast phase of K+ activation is specifically inhibited by 4-aminopyridine and by the substitution of D2O for H2O. We suggest Myxicola giant axons, like the amphibian node of Ranvier, may possess more than one variety of K+ channel.

4-Aminopyridine↗
PubMed1987

4-Aminopyridine improves clinical signs in multiple sclerosis.

Twelve temperature-sensitive male patients with multiple sclerosis and 5 normal men were monitored before, during, and after the intravenous injection of 7 to 35 mg of 4-aminopyridine (4-AP) in 1- to 5-mg doses, every 10 to 60 minutes. Static quantitative perimetry, flicker-fusion frequency, visual acuity, and videotaped neurological examinations were performed. Ten of the 12 patients showed mild to marked improvement. Vision improved in 7 patients, oculomotor function in 5, and motor function (power, coordination, gait) in 5. Improvements developed gradually within minutes of drug injection at doses as low as 2 mg, and gradually reversed around 2 to 4 hours after the peak drug effect. No effects were observed in 5 patients given saline injections. No serious side effects occurred in either the normal subjects or the patients receiving 4-AP. It is concluded that 4-AP lessens multiple neurological deficits in multiple sclerosis and, furthermore, that the K+ channel is functional in demyelinated central nervous system axons in humans. The improvements with 4-AP are substantial enough to be of transient therapeutic benefit in selected patients.

4-Aminopyridine↗
PubMed1987

Quality of health care measurement: a research priority.

The research issues in the assessment of quality of health care have not changed significantly during the past 20 years. What was changed is the increased interest among providers, consumers, and policymakers for ways to measure and compare quality among providers. Clearly there is an increased sense of urgency in the need for research in such areas as the development of improved measures of physiologic status, physiologic reserve, studies of all health care providers, studies of various subpopulations, more use of existing population and sample survey data bases through linkages, and implementation of uniform clinical reporting.

Data Collection↗
PubMed1985

Acute improvement in exacerbating multiple sclerosis produced by intravenous administration of mannitol.

The mode of action of adrenocorticotropic hormone (ACTH) treatment in exacerbating multiple sclerosis was studied by short-term infusions of agents that mimic specific and limited pharmacological actions of ACTH and observing for temporally phase-locked clinical changes. The study was double blinded, and agents were administered while the patients were being treated with a standard course of 10-day intramuscular ACTH therapy (40 U twice daily). Antiedema, alkalotic-hypocalcemic, extraadrenal, and sodium-retaining actions were studied using infusions of mannitol, sodium bicarbonate, ACTH, and sodium chloride, respectively. Seven of 8 patients receiving placebo infusions (2.5% glucose) showed no significant clinical change and 1 exhibited an equivocal improvement. Five of 9 patients receiving mannitol showed definite signs of clinical improvement phase-locked to drug administration, with subsequent gradual reversal to baseline. Similar improvements occurred with infusions of NaHCO3 in 5 of 8 patients and of ACTH in 4 of 8 patients. Three of 7 patients given NaCl infusion showed possible mild improvements. The results indicate that mannitol and NaHCO3 induced transient acute improvement in signs at the 95% confidence level in patients with exacerbating multiple sclerosis, with ACTH having a similar effect at the 90% confidence level. These agents mimic some of the known effects of ACTH, which may be important in the therapeutic action of ACTH in multiple sclerosis. A possible role for mannitol and high-dose ACTH in the treatment of demyelinating disease warrants further study.

Adrenocorticotropic Hormone↗
PubMed1983

Partial plasma protein replacement in therapeutic plasma exchange.

We wished to determine whether subtotal replacement of protein in plasma removed at plasma exchange would be adequate to prevent hypovolemia and hypoproteinemia. Seven well nourished outpatients with chronic progressive multiple sclerosis underwent 60 plasma exchanges in which two liters of plasma were replaced with 750 ml saline followed by 1250 ml of a 5% albumin solution (62.5% albumin replacement). Total serum protein, protein electrophoresis, and immunoglobulin levels were measured before and after each exchange. Clinically, the exchanges were well tolerated. Total serum protein dropped by a mean of only 18% during the study and mean preexchange serum albumin levels were unchanged, even though immunoglobulins decreased by 57-72%. We conclude that in well nourished patients, partial albumin replacement of this magnitude is an adequate substitute for plasma removed in a plasma exchange.

Adult↗
PubMed1983

Multiple sclerosis.

Explore the source record for details and available documents.

Adrenocorticotropic Hormone↗
PubMed1982

Plasmapheresis decreases neuroelectric blocking activity in multiple sclerosis.

Serum neuroelectric blocking factor activity diminished after plasmapheresis in five of seven patients with MS but returned to baseline levels in 2 to 3 weeks. In the other two patients changes were insignificant. All patients studied had progressing symptoms. Five plasma exchanges of 2 liters were performed in 10 days. Two patients improved clinically, whereas five did not. There was no correlation between the level of neuroelectric blocking activity and changes in clinical status.

Adult↗
PubMed1981

Decreased cell-mediated immunity to respiratory syncytial virus in multiple sclerosis.

We compared lymphocyte transformation to respiratory syncytial virus in patients with multiple sclerosis (MS) and in healthy controls. Lymphocyte transformation was decreased in MS in the presence or absence of autologous plasma, adding to the evidence that cellular immunity to viral antigens may be broadly impaired in MS, and does not occur uniquely for any single virus.

Adult↗