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Biomedical subjects

J S Howard

Publications and source records attributed to J S Howard.

At least 19 recordsLinked to original sources
PubMed1984

Errorless learning: reinforcement contingencies and stimulus control transfer in delayed prompting.

Delayed prompting can produce errorless discrimination learning. There is inherent in the procedure a disparity in reinforcement density which favors unprompted over prompted responses. We used three schedules of reinforcement to investigate the impact of reinforcement probability on transfer of stimulus control. One schedule of reinforcement was equal prior to and following a prompt (CRF/CRF), the second favored unprompted responses (CRF/FR3), and the third favored responses following the prompt (FR3/CRF). Experimental questions concerned the probability of errors, the probability of transfer, and the rate of transfer in the context of delayed prompting. Transfer was accelerated when reinforcement probability favored anticipatory responding. The schedule that favored prompted responses did not prevent a shift to unprompted responding. Errors were infrequent across procedures. Reinforcement probability contributes to but does not entirely determine transfer of stimulus control from a delayed prompt.

Adolescent↗
PubMed1980

Mitogenic activity and plasminogen activator in harvest fluid concentrates from mammary cells in culture.

Harvest fluid concentrates (HFC's) from three human mammary tumor cell lines (T47D), HSO578T, and MDA-MB-157), one nontumorigenic human mammary cell line (HBL-100), and one mouse mammary tumor cell line (MCG-T14) stimulated thymidine incorporation in confluent quiescent BALB/c 3T3 cells in a dose-dependent manner. HFC's from all of the cell lines also exhibited plasminogen activator activity. Levels of mitogenic activity and plasminogen activator in the HFC preparations were not correlated with cell growth potential or with the amount of protein which was recovered in the HFC's. High levels of mitogenic activity and plasminogen activator in the HFC's from HBL-100 cells suggested that the production of these biological activities is not a unique feature of tumorigenic mammary cells. The HFC's from three human cell lines (T47D), HS0578T, MDA-MB-157) exhibited high levels of mitogenic activity but low levels of plasminogen activator. This suggested that plasminogen activator is not the source of the mitogenic activity in the HFC's from these cells. The HFC's from a human mammary carcinoma line, BT-20, contained very low levels of mitogenic activity and plasminogen activator. In addition, BT-20 HFC's inhibited the mitogenic activity of fetal bovine serum in a dose-dependent manner. It is proposed that BT-20 cells are the source of a macromolecular inhibitor of serum mitogens.

Animals↗
PubMed1979

The synthesis of fetal hemoglobin types in red blood cells and in BFU-E derived colonies from peripheral blood of patients with sickle cell anemia, beta+ - and delta beta-thalassemia, various forms of hereditary persistence of fetal hemoglobin, normal adults and newborn.

The biosynthesis of two types of human fetal hemoglobin (Hb F), namely Hb F with G gamma chains having glycine in position 136 and Hb F with A gamma chains having alanine in position 136, was studied in blood samples and in cultures of erythroid precursors from blood of patients with different hemoglobinopathies. High pressure liquid chromatography (HPLC) was adapted to allow the separation of the methionyl-containing tryptic peptides G gamma T-15 and A gamma T-15 (which include the Gly leads to Ala polymorphism at position 136) from a digest of microquantitites of 35S-methionyl labelled Hb F. This method was sensitive enough to quantitate the relative production of the G ygamma and A gamma chains by erythroid colonies derived from cloned Burst Forming Units (bfu-e) which were cultured for 16 days on methylcellulose. The production of Hb F in these colonies was generally higher than the level of Hb F in blood except for subjects with the G gamma A gamma-HPFH heterozygosity. The G gamma to A gamma ratio in the Nb F produced in cultures of cells from G gamma delta beta-thalassemia or G gamma-HPFH heterozygotes was lower and that from A gamma-HPFH heterosygotes was higher than the ratios in the Hb F of the corresponding peripheral blood cells. Mixtures of G gamma and A gamma chains were present in cell cultures of SS patients, beta+-thalassemia homozygotes and G gamma A gamma-HPFH heterozygotes in a ratio similar to that in the Hb F of mature red cells. These data suggest that erythroblasts in BFU-E derived colonies reactivate all available gamma chain structural genes, both in cis and in trans to the abnormal determinant. Hb F biosynthesis by adult blood samples concerns primarily the G gamma chains. This was particularly striking for blood samples in which erythroblasts were absent and the biosynthesis took place in fetal reticulocytes. Thus, the F-retuculocytes in blood of A gamma-HPFH heterozygotes with about 5% Hb F of the A gamma type produced primarily Hb F with G gamma chains. Similar differences were observed for G gamma A gamma-HPFH heterozygotes and, less strinkingly, for SS patients. A satisfactory explanation for this observation has not yet been obtained.

Adult↗
PubMed1978

Liaison nursing.

In reviewing my efforts to clarify the role of the nurse clinician as a psychiatric consultant in a hospital setting, I came away with many impressions. Inherent in my search was a desire to experiment with various means of providing nursing service and much of my time was spent examining the collaborative aspects of the nursing role that would add greater depth to patient care. This involved role experimentation and allowed me the opportunity to develop my role within the context of the guidelines of community organization and consultation in a hospital setting. Although much of the time I found that the liaison role has been aimed at the supportive level, I have also discovered that as I developed security in the role wherein I could function in new and more independent ways--the parameters of the role expanded. Whereas initially I envisioned working only with nursing staff, I have found myself collaborating with many disciplines and many levels of care givers and I have also been able to function collaboratively with other psychiatric liaison team members. Thus, at this time I see the liaison nurse functioning basically as a coordinator, who, at any time, may assume one or more of the following roles: 1) Integrator; 2) Provider of direct services; 3) Educator and consultant; 4) Change agent.

Hospitals↗
PubMedDate not supplied

Tic douloureux, Parkinson's disease and the herpes connection.

Several cases encountered in psychiatric practice are described in which herpetic involvement of the trigeminal nerve appeared to be crucial to the pathophysiology of the patient's illness. A brief history of herpes is discussed in terms of the anatomy and physiology of the trigeminal nerve. Particular attention is given to the effects of intraneuronal herpes on gasserian ganglion and spinal nuclei discharge thresholds, as well as viral pathways directly impacting the substantia nigra. Evidence characterizing Parkinson's disease as one of several important manifestations of CNS herpes is covered.

Encephalitis, Viral↗
PubMedDate not supplied

Severe psychosis and the adrenal androgens.

Past literature suggests a link between certain psychotic states and adrenal androgen production, including Dehydroepiandrosterone (DHEA). A group of severely psychotic androgenized females, refractory to substantial amounts of neuroleptics, has been identified for whom endocrine testing revealed abnormally high levels of DHEA. A similar group has been identified among the severely psychotic male population. Improvement in psychosis appears to occur as DHEA returns to its normal range using standard low dose Dexamethasone suppression.

Adrenal Glands↗
PubMedDate not supplied

The psychosis of metabolic alkalosis.

Metabolic alkalosis as an additional etiology for organic psychosis is presented and covered, with theoretical and clinical considerations, including treatment. Illustrative case histories are cited and certain parameters of acid-base equilibrium are described as favorable to the normal awake state, while substantial deviation towards metabolic alkalosis is seen as conducive to psychotic aberration.

Acid-Base Equilibrium↗
PubMedDate not supplied

Cocaine, Neuroleptics, and tardive dyskinesia as paleocortical escape.

Human orobuccolingual movement is reviewed in terms of stimulation and inhibition within the striatonigral pathways and its domination and control by motor area 4 and the inhibitory neocortex. Haloperidol, clozapine and cocaine are then compared in terms of the effects of each on the physiology and function within these areas under normal and certain pathological conditions. Theoretical models are then derived that formulate evidence that a unique, previously unreported, combination of two distinct neurological circumstances must occur simultaneously to satisfy the criteria for pathological orobuccolingual movement.

Adult↗
PubMedDate not supplied

Requiem for "Schizophrenia".

In this article a brief overview of the treatment of chronic psychosis for the last two centuries is covered, with particular emphasis on many scientifically demonstrated causes of chronic organic psychosis and their medically successful treatment, including recent neurotransmitter manipulations. With respect for the important contributions of Bleuler, the term "schizophrenic" is considered as an unscientific and unprovable nosological construct, which has hampered the successful resolution of chronic psychosis and has outlived its usefulness in the lexicon of modern psychiatry.

Chronic Disease↗