Search PubMed⌕ Search

Biomedical subjects

C S Carter

Publications and source records attributed to C S Carter.

At least 109 records · Page 6Linked to original sources

Risperidone use in a teaching hospital during its first year after market approval: economic and clinical implications.

Risperidone, a new antipsychotic drug, was recently approved by the Food and Drug Administration (FDA) on the basis of its having comparable efficacy and less toxicity than haloperidol. In a preliminary study to evaluate the therapeutic efficiency of this drug, we conducted a survey of resperidone utilization, cost, and safety during its first year of availability at an academic psychiatric hospital. Data were obtained from a computerized, centralized medical record system, from an adverse drug reaction monitoring system, and from pharmacy purchasing records. In its first year of availability, risperidone became the second most widely used antipsychotic agent at our institution. Most of this use extended beyond the adult schizophrenia population, for whom pre-marketing safety and efficacy data are available. The direct institutional cost of risperidone treatment exceeded the entire budget for antipsychotic drugs during the year before its release. Results from the adverse drug reaction reporting system did not indicate a strong advantage of risperidone over more established antipsychotic agents with respect to extrapyramidal side effects. Furthermore, the mean dose of risperidone associated with extrapyramidal symptoms was 3.5 mg/day, considerably lower than that suggested by pre-marketing studies in a more select patient group. These results confirm that new pharmacological agents are generally used in much broader patient populations than those for which efficacy and safety have been established prior to FDA approval. This study also raises questions about the therapeutic efficiency of risperidone compared with other antipsychotic drugs. We conclude that systematic studies of outcome, safety, and cost of new pharmaceuticals in naturalistic settings are needed to provide the data necessary to establish local standards of cost-effective care.

Adolescent↗

Localization of 111indium-labeled tumor infiltrating lymphocytes to tumor in patients receiving adoptive immunotherapy. Augmentation with cyclophosphamide and correlation with response.

BACKGROUND: The adoptive transfer of interleukin-2 (IL-2)-cultured tumor infiltrating lymphocytes (TIL) can cause tumor regression in patients with metastatic melanoma. METHODS: Thirty-eight patients with metastatic melanoma receiving high dose IL-2 and TIL were studied for the ability of autologous 111In-labeled TIL to localize to metastatic tumor deposits by gamma camera imaging and biopsy. Single bolus cyclophosphamide was administered 24-36 hours before TIL infusion in 27 treatment courses. RESULTS: Tumor localization by 111In-labeled TIL was seen by gamma camera imaging in 26 (68.4%) treatment courses. In a univariate analysis of factors influencing TIL traffic, cyclophosphamide administration was significantly associated with the ability to localize tumor by radionuclide imaging (P2 = 0.026). Twenty-one of 26 (80.8%) treatment courses given with cyclophosphamide demonstrated tumor localization, compared with only 5 of 12 (41.7%) treatment courses without cyclophosphamide. In addition, patients whose 111In-labeled TIL imaged their tumor received significantly more TIL than did those that did not (P2 = 0.0052). Biopsies revealed a greater accumulation of 111In in cutaneous tumors than in normal skin biopsy specimens (0.0021 and 0.0004% injectate/gram of tissue, respectively; P2 = < 0.001). The median tumor-to-normal-skin ratio of simultaneous biopsies was 5.0. Finally, 10 of 26 (38.5%) patients who had tumor localization by scan had a clinical response, whereas no responses were noted in 12 patients whose tumors were not imaged (P2 = 0.022). CONCLUSIONS. Localization in tumor may be important in the mechanism of TIL antitumor activity because no clinical responses were seen in patients who did not have their tumors imaged with 111In-TIL. Cyclophosphamide administration before TIL and IL-2 therapy and the administration of large numbers of TIL appear to improve the frequency of TIL localization to tumor.

Adolescent↗

Patient Stage of Change predicts outcome in a panic disorder medication trial.

OBJECTIVE: The authors test the hypothesis that patient readiness to change predicts outcome in a placebo-controlled medication trial. METHOD: Out-patients with panic disorder and agoraphobia completed the Stages of Change (SOC) questionnaire, a measure of readiness to change, before being randomly assigned either sustained release (SR) adinazolam or placebo in a 4 week double-blind trial. RESULTS: In the "intent to treat" analysis, for the 202 subjects who made at least one visit after baseline, adinazolam SR was significantly more effective than placebo on most major outcome measures. Of the 126 subjects who completed the SOC questionnaire, regression analyses showed significant correlations between SOC scores and all 5 outcome measures. In a second analysis, cluster membership based on SOC scores was predictive of outcome on 3 of 5 measures. In each statistical analysis, subjects who were not predisposed to change as measured by the SOC were significantly less likely to change. CONCLUSIONS: Patient readiness to change was strongly correlated with outcome in a placebo-controlled panic disorder trial with an effective medication. In this study, the SOC category, Precontemplation (i.e., those subjects who reported the belief that they had no problem) were less likely to change compared to those who believed that they had a problem.

Agoraphobia↗

Olfactory bulbectomy decreases social behavior in male prairie voles (M. ochrogaster).

Prairie voles (Microtus ochrogaster) are social rodents that show characteristics of monogamy including high levels of social behavior and male parental care. Behavioral studies of prairie voles have implicated chemosignals in the control of various components of social behavior and reproduction. In the present study, the role of the olfactory system in male behavior was examined following surgical removal of the olfactory bulbs. Decreases in measures of sexual, paternal, and other social behaviors were observed following bilateral olfactory bulbectomy, but not unilateral or sham bulbectomy. Some bilaterally bulbectomized males also showed a stereotypy, but this probably did not account for the changes in social behaviors.

Animals↗

Attentional asymmetry in schizophrenia: the role of illness subtype and symptomatology.

1. Patients with undifferentiated and paranoid schizophrenia, and normal controls were compared using 2 versions of the covert orienting of attention procedure which evaluate exogenous (automatic) and endogenous (controlled) cuing mechanisms. 2. For both tasks, attentional performance varied with illness subtype, but in different ways. 3. On measures of automatic orienting undifferentiated patients showed evidence consistent with a mild right visual field deficit, while paranoid showed a reduction of inhibition-of-return, a mechanism which biases against returning to previously attended locations. 4. On measures of controlled orienting only the undifferentiated group showed the asymmetry of costs which has been the emphasis of most previous studies. The pattern of cost asymmetry was similar to that previously associated with prominent negative symptoms. Additionally, the magnitude of cost asymmetry correlated positively with negative symptoms in the overall patient group. 5. These findings show that systematically considering cue type and symptomatology are critical in interpreting varying patterns of performance by different groups of patients with schizophrenia on the covert orienting procedure. The implications of these findings for understanding the psychopathology of attention in schizophrenia and its neurobiological substrates are discussed.

Adult↗

Axon-sparing lesions of the medial nucleus of the amygdala decrease affiliative behaviors in the prairie vole (Microtus ochrogaster): behavioral and anatomical specificity.

The neural basis of affiliative behavior was examined in the prairie vole, a rodent that exhibits high levels of social contact and paternal behavior. In the first study, the axon-sparing excitotoxin N-methyl-D,L-aspartic acid (NMA) produced lesions in the basolateral nucleus of the amygdala or the corticomedial amygdala. Males with corticomedial lesions showed significantly less contact with a familiar adult female and a pup when compared with males with lesions of the basolateral nucleus or controls. This behavioral change was not associated with changes in exploratory behavior, motor function, performance in an olfactory task, fearfulness, physical well-being, or body temperature. In a second study, NMA lesions restricted to the medial nucleus also decreased paternal behavior. Neurons in the medial nucleus of the amygdala appear to be essential for the normal expression of paternal care in this species.

Amygdala↗

Estrogen receptor immunoreactivity in specific brain areas of the prairie vole (Microtus ochrogaster) is altered by sexual receptivity and genetic sex.

The prairie vole is a small rodent with an unusual reproductive strategy. A sexually naive female vole requires male contact to initiate the maturation of her reproductive functions. Contact with an unfamiliar adult male vole increases blood estrogen levels, reproductive tissue weights, and brain nuclear estrogen receptor binding levels of female voles. What is not known is: 1) What is the precise distribution of estrogen receptor containing neurons in the prairie vole brain? 2) Does male induced sexual receptivity alter the distribution or number of estrogen receptors in specific brain areas of the female vole? 3) Do male and female voles differ in the distribution or number of estrogen receptor containing neurons? We compared sexually receptive-male-exposed females, sexually naive females, and sexually naive males, for the presence of estrogen receptor immunoreactive (ER-IR) neurons in specific cell groups of the brain. The number of ER-IR neurons per cell group was counted and the relative amount of immunoreactivity per neuron was measured by densitometry. The neuroanatomical distribution of estrogen receptor containing neurons in the vole was similar to the distribution of estrogen receptors in most rodents. The mean number of ER-IR neurons did not differ between naive and male-exposed females. The induction of sexual receptivity however significantly decreased the concentration of estrogen receptor immunoreactivity per neuron in the medial preoptic nucleus, the medial preoptic area, the encapsulated bed nucleus of the stria terminalis, and the ventromedial nucleus of the hypothalamus. Compared with naive males, the mean number of ER-IR neurons was up to four fold greater in naive females in the medial preoptic nucleus, anteroventral periventricular preoptic nucleus, the encapsulated bed nucleus of the stria terminalis, the medial amygdala, and the ventromedial nucleus of the hypothalamus. Additionally the amount of estrogen receptor immunoreactivity per neuron was considerably greater in the medial preoptic nucleus, the medial preoptic area, the encapsulated bed nucleus of the stria terminalis, and the ventromedial nucleus of the hypothalamus of naive females. If the amount of estrogen receptor per cell is a determinant of a tissue's responsiveness to estrogen, reduced estrogen receptor immunoreactivity in males, and in females exposed to males suggests that they may be less responsive to estrogen than naive females. We propose that this reduced estrogen receptor immunoreactivity in males is a result of reduced estrogen receptor protein levels. Currently, we cannot definitively prove our working hypothesis that decreased estrogen receptor immunoreactivity in females exposed to males is due to reduced receptor levels, and not due to ligand altered epitope availability.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Oxytocin administered centrally facilitates formation of a partner preference in female prairie voles (Microtus ochrogaster).

Prairie voles (Microtus ochrogaster) are monogamous mammals that form male-female pair bonds. Partner preference formation, one component of the pair bond in prairie voles, occurs following male-female cohabitation and is facilitated by mating. The peptide hormone oxytocin is released during physical contact and particularly following vaginal stimulation. Oxytocin has been implicated in mother-infant bond formation. The present study tested the hypothesis that oxytocin participates in the partner preference component of pair bond formation in adult prairie voles. Ovariectomized female prairie voles were implanted with osmotic mini-pumps releasing oxytocin (1-100 ng/h) or artificial cerebrospinal fluid (CSF). Pumps were implanted intracerebroventricularly or subcutaneously and females then were housed for 6 h with a male partner, followed by a preference test in which females could elect to spend time with either the partner or an unfamiliar male. Females in groups that received centrally-administered oxytocin (10 or 100 ng/h), but not CSF, exhibited a significant preference for the partner present during infusion. The induction of a partner preference after oxytocin administration appeared specific for central oxytocin pathways as peripheral oxytocin administration was ineffective. Moreover, central administration of a selective oxytocin receptor antagonist inhibited the behavioral effect of exogenous oxytocin. These results suggest that oxytocin may be one factor contributing to the development of partner preferences in this monogamous rodent.

Amino Acid Sequence↗

A role for central vasopressin in pair bonding in monogamous prairie voles.

Monogamous social organization is characterized by selective affiliation with a partner, high levels of paternal behaviour and, in many species, intense aggression towards strangers for defence of territory, nest and mate. Although much has been written about the evolutionary causes of monogamy, little is known about the proximate mechanisms for pair bonding in monogamous mammals. The prairie vole, Microtus ochrogaster, is a monogamous, biparental rodent which exhibits long-term pair bonds characterized by selective affiliation (partner preference) and aggression. Here we describe the rapid development of both selective aggression and partner preferences following mating in the male of this species. We hypothesized that either arginine-vasopressin (AVP) or oxytocin (OT), two nine-amino-acid neuropeptides with diverse forebrain projections, could mediate the development of selective aggression and affiliation. This hypothesis was based on the following observations: (1) monogamous and polygamous voles differ specifically in the distribution of forebrain AVP and OT receptors; (2) AVP innervation in the prairie vole brain is sexually dimorphic and important for paternal behaviour; (3) central AVP pathways have been previously implicated in territorial displays and social memory; and (4) central OT pathways have been previously implicated in affiliative behaviours. We now demonstrate that central AVP is both necessary and sufficient for selective aggression and partner preference formation, two critical features of pair bonding in the monogamous prairie vole.

Aggression↗

Extended-cycle elutriation to adjust T-cell content in HLA-disparate bone marrow transplantation.

We report the development of a double-cycle elutriation (DCE) technique separating 3 or greater logs of T cells from a stem-cell-enriched marrow fraction and the results of phase I T-cell depletion studies with HLA-disparate related bone marrow transplantation (BMT) donors in two patient groups. In group 1, 10 patients with refractory hematopoietic malignancies received combination chemotherapy, total body irradiation (TBI), and immunosuppression (pre- and post-BMT), and hematopoietic rescue with a marrow transplant, depleted of T cells by elutriation. Potentially to promote engraftment and a graft-versus-leukemia (GVL) effect, 0.5 to 0.75 x 10(5) T cells/kg were added back. All 10 patients engrafted. Five patients developed acute graft-versus-host disease (GVHD; four grade II, one grade III) and two subsequently developed chronic GVHD. Two patients have relapsed (median follow-up, 206 days; range, 46 to 1,035). Four patients died of BMT-related complications (three of infection, one of veno-occlusive disease [VOD]). Four patient are disease-free survivors (median follow-up, 960 days; range, 670 to 1,035). Group 2 included five infants, four with congenital lymphohematopoietic deficiencies and one with refractory acute lymphocytic leukemia (ALL). In these infants, busulfan and increased cyclophosphamide were substituted for TBI. Only the ALL patient received added T cells. Three patients engrafted: one has stable mixed chimerism, one relapsed with ALL, and one rejected the marrow. One patient had primary autologous recovery, while another failed to engraft. None developed GVHD. We conclude that, in this setting of HLA-disparate BMT with post-BMT antithymocyte globulin (ATG) and corticosteroids, DCE significantly depletes T cells from the marrow and that a defined number of T cells can be added without the occurrence of severe GVHD.

Adolescent↗

Abnormal processing of irrelevant information in schizophrenia: the role of illness subtype.

In a study using a trial by trial version of the Stroop color naming task, we previously found that unmedicated patients with schizophrenia show a pattern of abnormal performance characterized by increased facilitation (speeding) of color-naming, color-congruent words but normal amounts of interference (slowing) of color-naming, color-incongruent words (Carter et al., 1992). Since a similar finding had recently been reported in patients with Parkinson's disease, we suggested that this finding was consistent with hypotheses about the neurobiological substrates of cognitive impairment that draw upon parallel patterns of cognitive performance in the two illnesses. We now report results from an enlarged group of unmedicated patients with schizophrenia that extend our original finding by allowing us to evaluate the role of illness subtype in abnormal performance on the Stroop task. We found that patients with the undifferentiated subtype of the disorder account for the increased Stroop facilitation effect. Patients with the paranoid subtype show their own pattern of abnormal performance, with normal amounts of facilitation and increased interference. These findings are consistent with the results of other studies which suggest that illness subtype is an important source of variability in studies of cognitive functioning in schizophrenia.

Adult↗

Benzodiazepine effects on flicker sensitivity: role of stimulus frequency and size.

1. Benzodiazepines (BZDs) impair sensitivity to temporally modulated visual stimuli (flicker). Critical flicker-fusion frequency (CFF) is commonly used as a measure of this effect, but it only measures sensitivity to a narrow range of frequencies, usually above 25 Hz. Are other frequencies more sensitive to the effects of BZDs? 2. Flicker sensitivity at 1, 2, 4, 8, 16, and 32 Hz was measured for 1 degrees and 5 degrees stimuli before and 50 to 100 minutes after triazolam (0.25 mg), lorazepam (1.0 mg) and placebo. Drug effects on CFF were also measured. 3. Both BZDs significantly impaired overall flicker sensitivity. Triazolam produced 50% more impairment than lorazepam. CFF was significantly impaired by triazolam. BZD effects did not vary with stimulus size. 4. Significantly greater BZD-induced impairment of flicker sensitivity occurred at 16 Hz than at 1, 2, 4, or 32 Hz. 5. The magnitude of BZD effects on flicker sensitivity vary with the temporal frequency of the stimulus. BZD effects are greatest for 8-16 Hz stimuli.

Adult↗

A study of the safety and survival of the adoptive transfer of genetically marked syngeneic lymphocytes in HIV-infected identical twins.

This phase I/II pilot project will evaluate the survival, tolerance, safety, and efficacy of infusions of activated, gene marked, syngeneic T lymphocytes obtained from HIV seronegative identical twins on the functional immune status of HIV infected twin recipients. T cells from each seronegative twin will be obtained by periodic apheresis, separated into CD4 and CD8 enriched populations by monoclonal antibody affinity binding techniques, induced to polyclonal proliferation with anti-CD3 and rIL-2 stimulation, transduced with distinctive neoR retroviral vectors, and expanded 10-1,000 fold in numbers during approximately 2 weeks of culture. These marked T cell fractions will then be infused into the seropositive twins and the survival of the uniquely marked T cell populations will be monitored by vector-specific PCR, while the recipients' functional immune status is monitored by standard in vitro and in vivo testing protocols. A total of 3 cycles of treatment will be given at intervals of 6 weeks between infusions.

Adolescent↗

Evidence that decreased function of lymphocyte beta adrenoreceptors reflects regulatory and adaptive processes in panic disorder with agoraphobia.

OBJECTIVE: This study was designed to clarify the nature of the reduced function of the peripheral beta adrenoceptor system observed in panic disorder with agoraphobia. The authors hypothesized that this phenomenon reflected a regulatory and adaptive process. METHODS: Lymphocyte beta adrenoreceptor density and affinity, basal lymphocyte cAMP level, and isoproterenol-stimulated cAMP generation were measured in 27 untreated outpatients with panic disorder with agoraphobia and 24 healthy comparison subjects. Lymphocyte beta receptor attributes were again assessed in patients after 4 weeks of double-blind treatment with adinazolam (slow-release form) or placebo. Panic frequency, agoraphobic symptoms, overall anxiety, and improvement with treatment were assessed with standard rating instruments. RESULTS: Multivariate statistics revealed significantly lower beta receptor density and isoproterenol-stimulated cAMP generation in patients than in comparison subjects. beta receptor density tended to normalize after adinazolam but not after placebo. Pretreatment beta receptor density was lower in treatment responders than nonresponders. Patients with mild agoraphobia had lower cAMP responsivity than patients with moderate or severe agoraphobia. CONCLUSIONS: Decreased function of lymphocyte beta receptors in panic disorder with agoraphobia is expressed as both decreased density and decreased cAMP responsivity. This pattern of changes, and the tendency for receptor density to normalize with treatment, is consistent with an active, regulatory process rather than a structural deficit in the beta receptor system. Preliminary clinical findings suggest that these changes may reflect adaptive processes associated with a favorable clinical course in panic disorder with agoraphobia.

Adult↗

Oxytocin and complex social behavior: species comparisons.

The neurohypophyseal peptide hormone oxytocin functions as a neuropeptide in several brain areas in addition to its role as a posterior pituitary hormone. Several studies have determined significant differences in patterns of oxytocin receptor binding in the brains of two closely related species of vole. One of the defining features of these two species is remarkably different reproductive behavior strategies. The prairie vole forms long-term monogamous relationships; the montane vole is polygamous. One potential measure of the formation of a pair bond in prairie voles is the development of intense aggressive behavior directed at male conspecifics following a mating bout. Oxytocin had little effect on aggressive behavior when administered before mating but had profound effects on the aggression of male prairie voles when administered after mating. Oxytocin had relatively modest effects on the behavior of montane voles, and neither the behavior nor the peptide effects were affected by mating experience. The data indicate that differences in peptide binding in these two species of vole may be functionally related to difference in social behavior.

Animals↗