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Biomedical subjects

S Axelrod

Publications and source records attributed to S Axelrod.

At least 19 recordsLinked to original sources
PubMed1992

Partial callosotomy and left-right response differentiation in the rat: separate anterior and posterior facilitatory effects.

Earlier research demonstrated that complete section of the corpus callosum in the rat reduced the number of trials required to acquire a left-right response differentiation (LRRD). This study was designed to investigate whether the facilitatory effect on LRRD could be produced by section of an anatomical subdivision of the callosum. Rats with sections of the anterior or posterior corpus callosum mastered the LRRD task faster than sham subjects, but more slowly than rats with total callosal section; section of the middle portion of the callosum had no such effect. The partial facilitatory effects of anterior and posterior callosotomy appear to be independent, and suggest that the callosal intermixing of lateral information, which contributes to left-right confusion, occurs at both the sensory and motor levels of processing.

Animals↗
PubMed1991

Improved acquisition of left-right response differentiation in the rat following section of the corpus callosum.

Split-brained rats learned a left-right response differentiation in a water maze significantly faster than rats with sham surgery. It is unlikely that this superiority resulted from improvement in performance variables since callosotomized rats did not differ significantly from sham operates in speed of acquisition of a brightness discrimination in the same apparatus. Additionally, callosotomy likewise had no effect on the acquisition of a water-maze task requiring consistent unilateral responses. The superiority of the callosotomized animals in forming the left-right response differentiation supports a hypothesis implicating the forebrain commissures in left-right confusion.

Animals↗
PubMed1991

Bladder outlet obstruction versus impaired detrusor contractility: the role of outflow.

The uroflow curves of 45 men with either bladder outlet obstruction or impaired detrusor contractility were retrospectively reviewed. The definitive diagnoses were attained by clinical and video-urodynamic studies with simultaneous detrusor pressure and uroflow measurements. Eight parameters were analyzed to determine if uroflow can differentiate obstruction from impaired contractility. There were no differences between the 2 groups in any of the parameters. This finding suggests that uroflowmetry as a single examination cannot distinguish between bladder outlet obstruction and impaired detrusor contractility.

Aged↗
PubMed1990

Failure of induced asymmetries to improve left-right response differentiation in the rat.

Rats (and humans) appear to be able to distinguish between left and right by referring to an intrinsic asymmetry as a navigational aid; this suggests that experimentally induced asymmetries might also facilitate such a distinction. We assessed the effects of asymmetries produced by unilateral shaving, unilateral vibrissotomy, and asymmetrical cortical lesions on acquisition of a left-right response differentiation. None of the treatments improved performance relative to appropriate control treatments; the rats were evidently unable to use these induced asymmetries to form the lateral differentiation. The results are related to evidence provided in an earlier report (Noonan & Axelrod, 1989) that even some reliable intrinsic asymmetries cannot function as navigational aids.

Animals↗
PubMed1990

Developing an alliance with schizophrenic patients in day hospital treatment.

For schizophrenic patients, denial of illness and resistance to treatment are pervasive during the subacute phase of the illness. The authors conceptualize these phenomena from a developmental perspective, with particular emphasis on self-reintegration. Theoretical concepts are discussed and guidelines for developing a treatment alliance are described. Clinical examples drawn from experience with schizophrenic patients in a day hospital setting are provided.

Adult↗
PubMed1989

Hypothalamo-pituitary-adrenal activity in endogenously depressed post-traumatic stress disorder patients.

We studied the hypothalamo-pituitary-adrenal (HPA) system in Vietnam veterans with post-traumatic stress disorder (PTSD) who also met Research Diagnostic Criteria for endogenous depression (MDD-ED). Over half also abused alcohol, and many complained of pain-confounding factors usually associated with increased HPA activity. Nonetheless, not even one patient had elevated basal plasma cortisol concentrations or an abnormal dexamethasone suppression test (DST); the subjects' post-dexamethasone cortisol values and plasma cortisol per ng plasma dexamethasone were in the low-normal range. These results highlight the biological heterogeneity of endogenous depression and its possible influence by past psychological trauma, and they raise questions about the use of current typological criteria for research purposes.

Adult↗
PubMed1989

The stability and interest consonance of lateral postural--motor biases in rats: results and implications.

Each of six different tests of lateral postural-motor asymmetries was repeatedly administered to 126 rats. Directional reliability was found for rotatory swimming, open-field exploration, and stepping down from a beam. Neonatal posture, turn in an unbaited T maze, and orientation to tail pinch proved not to be reliable across days. The behavioral asymmetries in the open-field and step-down tests were directionally consonant with each other, but neither was related to the asymmetry exhibited in rotatory swimming, implying the existence of at least two independent asymmetrical neural substrates underlying the behaviors. Neither sample-wide directional biases nor major sex differences in bias were found. The sexes were, however, differentially influenced in direction on some tests by the number of males in their natal litters, implying a role for intrauterine exposure to androgens in predisposing rats toward some left- or right-biased behaviors.

Aging↗
PubMed1989

Behavioral bias and left-right response differentiation in the rat.

To examine the proposition that lateral asymmetry facilitates left-right response differentiation in rats, we examined the relationships between the strengths of several behavioral biases and the scores on a learning task requiring left-right response differentiation. No support was found for a simple model positing a monotonic relationship between any behavioral bias and the learning scores. However, performance showed a U-shaped relationship to one behavioral bias. This finding conforms to a curvilinear model in which rats at either extreme of asymmetry are disadvantaged, at low degrees of asymmetry by a lack of navigational reference, and at high degrees by resultant strong position habits; moderately asymmetrical rats have neither disadvantage and are best able to use the asymmetry as a reference in processing left-right information.

Animals↗
PubMed1989

Factors associated with better compliance with psychiatric aftercare.

The rate of compliance with aftercare following hospitalization is disturbingly low despite its proven efficacy in preventing relapse and rehospitalization. This study of 134 emergency admissions to a New York City municipal hospital examined the impact of patient characteristics, clinical variables, and attitudes toward treatment on compliance with aftercare in the six months following discharge. Excluding 31 patients who required rehospitalization, 70 percent of patients attended their first aftercare appointment, and 40 percent completed six months of aftercare. Factors associated with better compliance with aftercare were continuity of care, as reflected in less time between discharge and the first aftercare appointment; increased number of prior hospitalizations; increased length of hospital stay; less denial of need for treatment; and greater perceived need for medications. Recommendations for improving compliance with after care are presented.

Aftercare↗
PubMed1988

The right to effective behavioral treatment.

We propose that individuals who are recipients or potential recipients of treatment designed to change their behavior have the right to a therapeutic environment, services whose overriding goal is personal welfare, treatment by a competent behavior analyst, programs that teach functional skills, behavioral assessment and ongoing evaluation, and the most effective treatment procedures available.

Activities of Daily Living↗
PubMed1987

Functional and structural analyses of behavior: approaches leading to reduced use of punishment procedures?

A common approach to dealing with the serious misbehaviors of handicapped individuals is to use punishment procedures. Although punishment techniques are often effective, many claim that their use is restrictive. Emerging approaches for dealing with inappropriate behavior are to conduct a functional or structural analysis of behavior. These approaches allow practitioners to isolate and manipulate the factors responsible for aberrant behaviors. Such analyses may reveal that a maladaptive behavior results in adult attention, is associated with demand situations, or provides reinforcing sensory feedback. In each case corrective procedures relevant to the function of the inappropriate behavior or its associated stimuli, can be applied. In some cases the analysis will reveal alternative approaches to the use of punishment procedures. In other cases it may not. Presently, there have been relatively few examples of the functional and structural analysis approaches; results thus far, however, have been encouraging.

Behavior↗
PubMed1987

Spectral analysis of fluctuations in heart rate: an objective evaluation of autonomic nervous control in chronic renal failure.

A quantitative, noninvasive method of assessing autonomic control, based on the spectral analysis of beat-to-beat fluctuations in heart rate (HR), was applied to patients with chronic renal failure (RF). Since the power spectrum of HR fluctuations measures the dynamic nervous control of HR, it can be used to quantitate a normal control system as opposed to a disturbed or depressed system. Indeed, in RF patients, a strong reduction in the HR power spectrum was observed in all frequency ranges, both sympathetically and parasympathetically mediated. A similar depression in autonomic control was demonstrated in patients on hemodialysis or peritoneal dialysis. RF patients not yet undergoing dialysis show a lesser degree of depression. Spectral analysis of HR fluctuations in RF patients makes it possible to quantitate autonomic dysfunction and to reliably measure its development as a function of time, and requires only a 10-min standard electrocardiogram recording.

Adult↗
PubMed1987

Efficacy of strontium chloride in dental hypersensitivity.

Controlled stimuli were used to evaluate a commercially available dentifrice containing 10% strontium chloride hexahydrate for efficacy in alleviating the symptoms of uncomplicated dentinal hypersensitivity. Sixty-one subjects with hypersensitivity were included in the 12-week, double-blind, parallel, comparative (placebo) study. Levels of hypersensitivity in affected teeth were assessed by three methods: thermally controlled cold air stimulus, tactile stimulus with an electronic pressure sensitive probe, and subjective response. The results from all three methods of assessment indicated that the strontium chloride dentifrice, in comparison with a placebo, reduced dentinal hypersensitivity to a significantly greater degree. This therapeutic response to the active agent was apparent within 2 weeks and increased continuously thereafter for the length of the study. One can conclude that the regular at-home use of a dentifrice containing 10% strontium chloride hexahydrate is an effective means for reducing the discomfort and pain engendered by thermal and tactile stimuli in patients with dentinal hypersensitivity.

Adolescent↗