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Biomedical subjects

W A Morton

Publications and source records attributed to W A Morton.

32 records · Page 2Linked to original sources
PubMed1984

The clinical usefulness of lithium as an antidepressant.

Much attention has been directed toward the use of lithium in bipolar depressive illness (manic-depressive illness), but fewer studies have evaluated lithium's efficacy in unipolar depressive disorders. This paper critically reviews the literature dealing with the use of lithium for the treatment of acute unipolar depression as well as for prophylaxis against future depressive episodes. Differences in study design, entry criteria, serum lithium level, dose, patient population, and diagnosis are highlighted; these variations help explain some of the controversy surrounding the use of lithium in unipolar depression. The available information indicates that lithium should be seriously considered as an effective alternative for the treatment of unipolar depression when other antidepressant medications are ineffective or contraindicated.

Antidepressive Agents↗
PubMed1983

Impact of regulations on artificial organs research.

From a research perspective, some of the primary problems created by the FDA regulations include: the amount of time necessary to comply with the regulations and to obtain FDA and IRB review of the studies. The cost of such delays may be great in terms of statistical death. Lack of understanding of the regulations on the part of investigators. Escalated costs and extra restrictions on the use of animals. Benefits of the regulations appear to be: better preclinical testing performed prior to initiating clinical trials, and improved testing protocols, both of which may result in lower risks to patients.

Artificial Organs↗
PubMed1982

Regulatory pathways to the market: an overview.

This paper presents an overview of the U.S. Food and Drug Administration's regulatory requirements for introducing medical device and diagnostic products into commercial distribution in the United States. For any specific product, the requirements vary depending upon the product's associated risks, classification, and when it or a similar product was first introduced into commercial distribution. Regulatory pathways available and/or required for a manufacturer to introduce a medical product into the U.S. marketplace are outlined.

Clinical Trials as Topic↗
PubMed1981

Use of Lilium longiflorum, cv. ace pollen germination and tube elongation as a bioassay for the hepatocarcinogens, aflatoxins.

Although various animal tissues are used for bioassay of aflatoxins (B1, B2, G1, G2), a rapid bioassay dependent upon a plant part's response does not exist. Both pollen germination (G) and tube elongation (TE) were enhanced in a 3.0 mM KH2PO4 (K)-containing but AFB1-lacking, modified Dickinson's medium. The B1 did not affect G when K was withheld but K supplementation impaired G above 15 micrograms/ml B1. Without K, 5-20 stimulated but 25 and 30 micrograms/ml B1 inhibited TE which was suppressed by every B1 conc tested in K-containing medium. Addition of NaH2PO4(N) instead of K to medium did not promote G. Slight G stimulation occurred at 16.6 micrograms/ml mixed aflatoxins (MA) in medium lacking either K or N but low G inhibitions were observed with K or N. The MA at 33.3 micrograms/ml reduced G 2.5% in K's of N's absence and 26 or 17% in their presence. While K did not stimulate TE without MA, N did 26%. At 16.6 and 33.3 micrograms/ml MA, TE was reduced 19, 6, 19% and 24, 25, 31%, respectively, in control, K- and N- media. Pollen G and TE were markedly sensitive to G1. Significant inhibitions of Zea mays seed G were observed at 5.8 and 11.6 micrograms/ml B1 but not root elongation (RE) from 0.4-11.6 micrograms/ml. The MA (31.5 micrograms/ml) administered for 72-240 hr did not influence either Arachis hypogeae seed G or RE. However, imbibing 5 cultivars each of Avena sativa (65-117 hr) and Hordeum vulgare (39-89 hr) inhibited RE 4/15-62%. Thus, except for Z. mays, pollen G and TE appear to be more B1-sensitive than seed G and RE. But, the pollen bioassay is less sensitive than both certain animal bioassays (0.025 micrograms/ml) and analytical methodologies (10 pg.).

Aflatoxins↗
PubMed1980

Improvement in antiepileptic drug levels following reduction of intervals between clinic visits.

Antiepileptic drug levels (AEDLs) may reflect how well patients adhere to prescribed medical regimens. Of 30 patients on stable drug regimens AEDLs were increased in 33% by decreasing clinic visit intervals from a mean of 3.4 months to 1.1 months. The testing situation was applied to patients who had AEDLs in the "therapeutic range" (n = 15) as well as those with one or more AEDLs below "therapeutic range" (n = 15). In the latter group 73% of patients showed improvement in AEDLs. Although a less reliable parameter, verbally reported seizure frequencies were also improved. Overall, the reduction in clinic visit interval could be expected to yield improvement in 46 to 80% (confidence interval = 95%). These patients responded equally well to physician and non-physician practitioners. This technique may be useful as an intervening measure for those patients who are noncompliant.

Adolescent↗
PubMed1978

Pharmaceutical services in a medical screening clinic.

Pharmaceutical services in a medical screening clinic are described. Services provided include medication refills, patient education and medication histories. During the first year 1,067 patients were interviewed, evaluated and received these services from the pharmacist. The majority of these patients were seen for medication refills. A clinical assessment was made by the pharmacist of the current drug therapy, evidence of new or drug-related problems, and compliance with medication regimens. One hundred seventy-six patients were found to be receiving inappropriate drug therapy, 69 patients were found to have drug-related problems and 248 patients were found to be noncompliant with their drug regimens. Patients received 1,633 refills and 24 new prescriptions. One hundred fifty patients were refused refills because the medications were being abused or were not indicated. Many patients (564) received extensive education about their medications and diseases. One hundred eleven laboratory tests were ordered and 323 clinic appointments were made. The pharmacist is providing services which are an asset to both patients and other members of the health care team.

Ambulatory Care↗
PubMed1977

Effects of polymer surface molecular structure and force-field characteristics on blood interfacial phenomena.

To quantify the effects of major surface structural factors influencing interfacial reactions induced by polymers in native blood, model surfaces of solvent-cast films of two analogous poly(ether urethanes) and three homologous polyamides (nylon 4, 6/6, and 12) were exposed ex vivo to canine blood under the well-defined hemodynamic conditions of the Stagnation Point Flow Experiment. The selected surfaces allow for incremental changes in properties and were characterized by their "Composite Surface Free ENergy Function," gamma'S, which describes the surface force field as the sum of the mean dispersion (gammaSd) and polar (gammaSp) contributions and is computed from wettability spectra obtained with ultrapure diagnostic liquids. Blood interfacial effects were measured by the shear-limited diameter of the white cell circle formed around the stagnation point, the flow parameter at which symmetric aggregation occurred, and the surface-number density of platelets, [P s], remaining adherent under fixed conditions. At identical flows, within each group of polymers, both the WBC-circle diameter and [P s] scale with gamma Sp/gamma'S, implying that 1) only the magnitude but not the interaction mechanism varies as a function of incremental structural and surface changes, 2) the primary determinant of surface-induced effects is the polar force contribution, and 3) the magnitude of gamma'S is secondary if gammaSd/gamma'S is sufficiently great.

Adsorption↗
PubMed1975

Study of aggregate formation in region of separated blood flow.

The formation of platelet aggregates which embolize to the peripheral circulation has previously been noted as a significant deleterious effect resulting from both intra- and extracorporeal artificial circulatory devices. Utilizing the stagnation point flow experiment, which permits visualization during flow of aggregate formation on first contact of blood with an artificial surface, the formation of freely floating aggregates has been observed in separated flow regions. Embolization from the separated flow has also been noted. Comparison of observed growth rates with a hydrodynamic model suggests that sufficient activation has occurred within the separated region so that platelets stick on virtually every collision. Some criteria are also suggested which correlate with the flow conditions affecting aggregate formation. At high flow rates, where freely floating aggregates do not form, significant surface thrombi are found.

Animals↗
PubMedDate not supplied

Effect of fluvoxamine, imipramine and placebo on catecholamine function in depressed outpatients.

Many of the specific serotonin reuptake inhibitors appear to have some effect on noradrenergic function. Fluvoxamine is one of the newer agents and its specificity has not been fully assessed. Depressed patients participating in a study comparing the efficacy of fluvoxamine with imipramine and placebo collected 24 hour urine samples (N = 38) and had plasma samples drawn (N = 38) prior to and after 6 weeks of double blind treatment. Urine samples were analyzed for 24 hour output of MHPG, VMA, NMN, MN and HVA. Plasma samples were analyzed for NE levels. Imipramine treatment produced a reduction in urinary MHPG, an increase in the ratio of NMN to MHPG plus VMA, and a trend towards an increase in plasma NE which was significantly different than the effects seen in the fluvoxamine and placebo groups. There was an additional finding in the imipramine group of a significant correlation between percentage change in plasma NE and clinical improvement. Fluvoxamine treatment, on the other hand, produced no clear effect on any measure of noradrenergic function and the antidepressant efficacy of fluvoxamine was unrelated to any noradrenergic variable. These findings lend support to the hypothesis that fluvoxamine does not have significant effects on noradrenergic function.

Adolescent↗