Baseline [18F]FDG PET features are associated with survival and toxicity in patients treated with CAR T cells for large B cell lymphoma

PURPOSE

Chimeric antigen receptor (CAR) T cells have established themselves as an effective treatment for refractory or relapsed large B cell lymphoma (LBCL). Recently, the sDmax, which corresponds to the distance separating the two farthest lesions standardized by the patient's body surface area, has appeared as a prognostic factor in LBCL. This study aimed to identify [18F]FDG-PET biomarkers associated with prognosis and predictive of adverse events in patients treated with CAR T cells.

METHODS

Patients were retrospectively included from two different university hospitals. They were being treated with CAR T cells for LBCL and underwent [18F]FDG-PET just before CAR T cell infusion. Lesions were segmented semi-automatically with a threshold of 41% of the maximal uptake. In addition to clinico-biological features, sDmax, total metabolic tumor volume (TMTV), SUVmax, and uptake intensity of healthy lymphoid organs and liver were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The occurrence of adverse events, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), was reported.

RESULTS

Fifty-six patients were included. The median follow-up was 9.7 months. Multivariate analysis showed that TMTV (cut-off of 36 mL) was an independent prognostic factor for PFS (p < 0.001) and that sDmax (cut-off of 0.15 m-1) was an independent prognostic factor for OS (p = 0.008). Concerning the occurrence of adverse events, a C-reactive protein level > 35 mg/L (p = 0.006) and a liver SUVmean > 2.5 (p = 0.027) before CAR T cells were associated with grade 2 to 4 CRS and a spleen SUVmean > 1.9 with grade 2 to 4 ICANS.

CONCLUSION

TMTV and sDmax had independent prognostic values, respectively, on PFS and OS. Regarding adverse events, the mean liver and spleen uptakes were associated with the occurrence of grade 2 to 4 CRS and ICANS, respectively. Integrating these biomarkers into the clinical workflow could be useful for early adaptation of patients management.

[Inflammatory syndrome of unknown origin and PET/CT: Economic and iatrogenic impacts of false positive]

INTRODUCTION

PET/CT is regularly used to investigate inflammatory syndrome of unknown origin (IUO), but hypermetabolisms found are not always consistent with the final diagnosis. The objective of the study was to assess the cost attributed to the diagnostic work-up for these false positives.

MATERIALS AND METHODS

We conducted an ancillary study on a previous retrospective cohort from the internal medicine department at Amiens university hospital in patients who had a PET/CT scan between October 2004 and April 2017. Patients were included if PET/CT had been prescribed to investigate IUO. Among the 763 PET/CT performed, 144 met the inclusion criteria and a false-positive rate of 17.4% (n=25) was reported.

RESULTS

Among these 25 patients, 21 underwent further investigations. The most frequently found hypermetabolic territories were digestive (n=12, mean SUVmax 8 [±4.33]) and osteoarticular (n=11, mean SUVmax 4.33 [±1.15]). The total cost of the 13 prescribed consultations was €390, the total cost of the 40 additional tests was €4,476 (mainly digestive endoscopies and radiological tests) and the total cost of medical transport was €572. The total cost of the 35 days of hospitalization specifically required to investigate these false positives was €22,952. In 23.8% (n=5), these investigations led to the incidental discovery of tumor lesions.

CONCLUSION

The economic impact of false-positive PET/CT results does not appear to be negligible and merits a genuine prospective medico-economic study.

Abstract OT2-4-02: Young and strong: A randomized trial to evaluate a program for young women with breast cancer

Young women with newly diagnosed breast cancer face substantial challenges including higher risk of disease recurrence and likelihood of harboring a genetic mutation compared with older women. Many young women are also very concerned about their future fertility and this population often feels isolated from other breast cancer survivors due to their age and life stage. Some worry that their doctors are unsure of how to treat them. To address these issues, we developed a comprehensive program at our institution to coordinate and enhance the care, support, and education for young women with breast cancer. The Young and Strong study is a randomized clinical trial (RCT) to evaluate a virtual, exportable, scalable version of this program designed to improve the quality of care and the psychosocial well-being of this vulnerable population.

The specific aims of this program are:

1) To develop, pilot, and refine an exportable and sustainable educational and support intervention for young women with breast cancer and their oncology providers (Young Women's Intervention; YWI).

2) To determine the effect of the YWI compared to a contact-time control intervention focused on promoting physical activity (Physical Activity Intervention; PAI) on attention to fertility issues in a RCT: “Young and Strong”.

We initially conducted 4 focus groups (n = 36) and 20 key informant interviews, and developed, piloted, and refined the YWI as well as the PAI. Based on this successful work, we launched the Young and Strong study in June 2012 as a cluster-randomized trial at a total of 54 sites (40 community and 14 academic sites across the United States). Randomization is 1:1 between sites, and stratified by practice type (community vs. academic). Each community site will enroll 5-10 participants, each academic site 15 participants. Total recruitment will be 410-610 pts. The primary objective is to evaluate whether YWI, as compared to PAI, is associated with greater attention to fertility issues, assessed via medical record review. In addition, participants will complete assessments at baseline, 3, 6, and 12 months that assess satisfaction with care, psychosocial well-being, physical activity and anthropomorphic changes.

Young and Strong activated in June 2012 and all sites have been identified. As of 6/11/2013 the study has been initiated at 53 out of 54 sites, and total of 282 women have enrolled on the study.

Eligibility Criteria:

1. Women age 18-45 years at diagnosis

2. Stage I-III invasive breast cancer without known recurrence or metastatic disease

3. Newly-diagnosed (within 3 months of initial diagnosis)

4. Have 1st appt. with a medical oncologist at participating site after the site opens to enrollment

5. Able to read and write in English

For further information, contact Ann Partridge, MD, MPH at 888-814-3324.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-4-02.

Abstract P2-18-02: Factors associated with contralateral prophylactic mastectomy in young women with breast cancer

Background: While younger age at diagnosis has consistently been identified as a predictor of contralateral prophylactic mastectomy (CPM), little is known about how clinical, decisional, and psychosocial factors are related to the decision to undergo CPM in young women with breast cancer.

Methods: As part of an ongoing, multi-center cohort study of young women diagnosed with breast cancer at age 40 or younger, we identified 428 women with unilateral Stage I-III disease. Participants were asked to complete surveys by mail that included questions about decision-making and treatments. Tumor characteristics were ascertained via medical record review. Multinomial logistic regression was used to identify predictors of: 1) CPM vs. unilateral mastectomy (UM); 2) CPM vs. breast conserving surgery (BCS). Independent variables with a p-value ≤ 0.15 in bi-variate analyses were included in the final multivariable model.

Results: 41% of women had CPM, 29% had UM and 31% had BCS. Median age at diagnosis was 37 (range: 17-40). Most women had stage I or II disease (87%), and estrogen receptor (ER) positive tumors (69%); approximately 14% were carriers of a BRCA 1 or 2 mutation. In the multivariable analysis (Table 1), having a cancer-predisposing mutation, having at least one child, anxiety as measured by the Hospital Anxiety and Depression Scale (HADS), and patient-driven decision making were all associated with a greater likelihood of undergoing CPM, while women who reported their physician made the final decision about surgery were less likely to undergo CPM, compared to both UM and BCS. Additional factors significantly associated with undergoing CPM vs. BCS included nodal involvement, Her2 positivity, and lower BMI. Race/ethnicity, marital status, tumor size, tumor grade, depression (as measured by the HADS), fear of recurrence, and having a first-degree relative with breast or ovarian cancer were not associated with undergoing CPM.

Conclusion: Many young women with early stage breast cancer are choosing to undergo CPM. Our findings point to the need for improved communication with patients regarding surgical choices as well as better management of anxiety surrounding diagnosis. Interventions aimed at enhancing risk communication and encouraging shared patient-physician decision-making might be beneficial in this setting.

Table 1. Factors associated with: 1) CPM vs. UM; 2) CPM vs. BCS CPM vs. UMCPM vs. BCS OR (95% CI)OR (95% CI)Age at diagnosis0.92 (0.86-1.00)0.97 (0.90-1.04)Mutation positive3.83 (1.60-9.15)14.51 (5.02-41.92)Any nodal involvement0.79 (0.45-1.38)1.93 (1.05-3.55)Her2 positivity0.71 (0.40-1.26)2.24 (1.18-4.25)Having ≥ 1 child2.08 (1.04-4.14)3.25 (1.63-6.48)BMI0.98 (0.92-1.03)0.92 (0.87-0.97)Anxiety1.93 (1.05-3.56)2.31 (1.22-4.35)Decisional involvement (ref = shared)  Mainly patient's decision3.47 (1.99-6.06)3.71 (2.09-6.58)Mainly doctor's decision0.14 (0.03-0.63)0.16 (0.03-0.77)

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-18-02.

Abstract P4-01-09: Screening breast magnetic resonance imaging (MRI) in early-stage breast cancer survivors

Background: Limited evidence is available regarding the value of screening breast MRI in female early stage breast cancer survivors. We sought to evaluate outcomes of index screening breast MRI in breast cancer survivors in the modern era of breast cancer treatment and imaging.

Methods: Using a large prospective institutional database, we identified all women who underwent breast MRI between 7/2006 and 6/2008, were ≥ 1 year and ≤ 3 years after diagnosis of stage I-IIIa breast cancer, had remaining breast tissue after treatment, and had consented to a record review protocol at our center (95% uptake rate). Sociodemographic, disease, staging and treatment information (see table 1), indications and outcomes for breast MRI, as well as disease status at 2 years after the index MRI were ascertained.

Results: 643 patients were identified as having undergone at least 1 MRI of the breast(s); 248 (38.5%) were diagnostic MRIs (had identified clinical indication or imaging abnormality); 12 (2%) were missing clinical data; 383 (59.5%) were screening MRIs. 338/383 (88%) patients who had screening MRI had stage I-IIIa invasive breast cancer. 220/338 (65%) MRIs performed were index MRIs (index MRI defined as first MRI &gt;1 year post diagnosis). For this preliminary analysis, we include only the 155 patients (70%) who were within 1–3 years of diagnosis at the time of index MRI (see table 1 for patient and disease characteristics).

24/155 (15.5%) screening MRIs were considered not normal. Five women (21%) underwent biopsy based on abnormal MRI finding; 1 resulted in the detection of a local recurrence (4.2%, 95% CI=0.1%–21.1%). 3/131 patients who had a normal index MRI were found to have local/regional recurrence or contralateral breast cancer diagnosed within 2 years of the MRI (2.3%, 95% CI=0.5%–6.6%). A statistically significant difference in the proportions was not observed based on Fisher's test (p = 0.50). 6/155 patients (3.9 %) had a systemic recurrence in the 2 years following index MRI.

Abstract P2-15-01: Long-Term Risk Perceptions and Quality of Life of Women with Ductal Carcinoma In Situ

Background: Research has demonstrated that many women with ductal carcinoma in situ (DCIS) overestimate their risk of future breast cancer events. However, no prior studies have evaluated risk perceptions in long-term follow-up.

Methods: As part of a multicenter longitudinal cohort study, we mailed long-term follow-up surveys to 315 of 392 women who had previously responded to a survey 18 months after they were diagnosed with DCIS (33 of the 392 were excluded because they were receiving follow-up care at outside centers, and 44 because of recurrence/death). We evaluated psychosocial distress by Hospitalized Anxiety and Depression Scale (HADS) and Revised Impact of Events Scale (RIES), quality of life (QOL) by Short Form Health Survey (SF-36), and risk perceptions with items used previously in the cohort.

Results: One hundred ninety-three women (61%) responded. They were a median age of 53 yrs (range 31-89) and a median of 5.8 yrs from diagnosis (range 4.3-7.0). Twelve were excluded due to report of recurrence. Of the 181 remaining, 32% perceived at least a moderate risk of developing DCIS again within 5 yrs; 43% perceived at least a moderate lifetime risk of developing DCIS again; 27% perceived at least a moderate risk of developing invasive breast cancer within 5 yrs; 38% perceived at least a moderate lifetime risk of developing invasive breast cancer; 24% perceived at least a moderate risk of DCIS spreading to other parts of their bodies. For qualitative responses of ≥ moderate perceived risk, median quantitative risk perception was 10% regarding 5-yr risk of DCIS or invasive cancer, 20% regarding lifetime risk, and 50% pertaining to risk of DCIS spreading. The proportion of women reporting ≥ moderate perceived risk of DCIS spreading remained stable over time (25% at baseline; 26% at 18 mos), but this proportion decreased for other perceptions of risk (e.g., at baseline and 18 mos, 51% and 50% of these same women perceived ≥ moderate risk of developing DCIS again within 5 yrs). In a multivariable model, worse financial status (OR 2.6, 95% CI 1.3-5.3) and higher perceived risk on earlier surveys (OR 24.4, 95% CI 12.7-47.2) were the only predictors of ≥ moderate perception of risk of DCIS spreading to other parts of the body in long-term follow-up. Non-significant covariates included age, race, education, grade of DCIS, comedonecrosis, mastectomy, radiation, marital status, employment status, comorbidity, and HADS and RIES scores. This contrasted with earlier survey data, which demonstrated an association between higher risk perceptions and anxiety by HADS and RIES. In long-term follow-up, only 7% were found to be anxious (HADS Anxiety ≥11) and 0.6% were depressed (HADS Depression ≥11). Median SF-36 scores were 48.9 (range 15.7-58.2) and 47.1 (range 23.6-60.3) for the physical and mental components, respectively, consistent with overall good QOL.

Conclusions: Women with a history of DCIS continue to harbor inaccurate perceptions of risk of future breast cancer events even at 6 yrs follow-up. Future research should evaluate how these excessive risk perceptions impact health behaviors. Interventions to improve risk perceptions are warranted.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-15-01.

Phase-contrast MR imaging support for the diagnosis of aqueductal stenosis

BACKGROUND AND PURPOSE

Patients with aqueductal stenosis (AS) present with various clinical and radiologic features. Conventional MR imaging provides useful information in AS but depends on a subjective evaluation by the neuroradiologist. The purpose of this study was to evaluate the support of the phase-contrast MR imaging (PC-MR imaging) technique (sensitive to CSF flows) for the diagnosis of AS.

MATERIALS AND METHODS

We retrospectively considered 17 patients who underwent PC-MR imaging to explore hydrocephalus, with the absence of CSF flow at the aqueductal level. We analyzed their clinical and morphologic MR imaging data.

RESULTS

None of the usually reported direct or indirect signs of aqueductal obstruction were seen in 7 patients in whom the clinical suggestion of AS was confirmed by PC-MR imaging results. Seven patients in this population had a third ventriculostomy, and 5 of them were among those in whom conventional MR imaging failed to reveal signs of aqueductal obstruction. All of these 7 patients had a positive postsurgical outcomes. The analysis of CSF and vascular dynamic data in this population was compared with an aged-matched population, and these data were found similar except for the fourth ventricular CSF flush flow latency.

CONCLUSIONS

PC-MR imaging supports the diagnosis of CSF flow blockage at the aqueductal level in a reliable, reproducible, and rapid way, which aids in the diagnosis of AS in patients with clinical and/or radiologic suggestion of obstructive hydrocephalus. We, therefore, suggest using this technique in the current evaluation of hydrocephalus.

[Acute CSF changes in the mesencephalon aqueduct after subarachnoid hemorrhage as measured by PC-MRI]

PURPOSE

Determining acute intracranial hydrodynamic changes after subarachnoid hemorrhage through an analysis of the CSF stroke volume (SV) as measured by phase-contrast MRI (PC-MRI) in the mesencephalon aqueduct.

METHOD

A prospective study was performed in 33 patients with subarachnoid hemorrhage. A PC-MRI imaging study was performed n the acute phase (< 48 hours). CSF flow was measured in the aqueduct. The appearance of acute hydrocephalus (HCA) was then compared with data on CSF flow, and the location of the intraventricular and perimesencephalic bleeding.

RESULTS

CSF analysis was performed on 27 patients, 11 of whom presented with an acute HCA. All 11 patients had an abnormal SV in the aqueduct: patients with a communicating HCA had an increased SV (n=8); and patients with a noncommunicating HCA had a nil SV (n=3). Patients with a normal SV in the aqueduct did not develop an acute HCA. Intraventricular bleeding significantly led to HCA (P=0.02), which was of the communicating type in 70% of cases.

CONCLUSION

Subarachnoid hemorrhage leads to intracranial CSF hydrodynamic modifications in the aqueduct in the majority of patients. CSF flow can help us to understand the mechanism of the appearance of acute HCA. Indeed, hydrocephalus occurred - of the communicating type in most cases - even in the presence of intraventricular bleeding.

Differences in effective connectivity between dyslexic children and normal readers during a pseudoword reading task: an fMRI study

PURPOSE

This fMRI study investigated phonological and lexicosemantic processing in dyslexic and in chronological age- and reading level-matched children in a pseudoword reading task.

MATERIALS AND METHODS

The effective connectivity network was compared between the three groups using a structural model including the supramarginal cortex (BA 40; BA: Brodmann area), fusiform cortex (BA 37) and inferior frontal cortex (BA 44/45) areas of the left hemisphere.

RESULTS

The results revealed differences in connectivity patterns. In dyslexic patients, in contrast with chronological age- and reading level-matched groups, no causal relationship was demonstrated between BA 40 and BA 44/45. However, a significant causal relationship was demonstrated between BA 37 and BA 44/45 both in dyslexic children and in the reading level-matched group.

CONCLUSIONS

These findings were interpreted as evidence for a phonological deficit in developmental dyslexia.

[Contribution of the spectral analysis to the brain connectivity study by fMRI]

AIM

To validate, through functional magnetic resonance imaging (fMRI) from spectral analysis of time series during a visuomotor task, a model of functional connectivity mainly constituted by the pre-supplementary motor area (pre-SMA), the supplementary motor area proper (SMA-proper) and the primary motor cortex (M1).

MATERIALS AND METHODS

The paradigm that was tried out in young subjects (n=5) consisted of a preparation task of motor movement. We firstly proceeded with an estimate in the frequency domain of coherency coefficients and values of phase shift between these three areas. Secondly, the estimated coherency coefficients were integrated to a model of functional connectivity. Two interaction coefficients were calculated, one for the related M1 and pre-SMA regions, the other one for the related M1 and SMA-proper regions.

RESULTS AND CONCLUSION

Our results demonstrate hemodynamic activity that definitely occurred earlier in the pre-SMA area during the preparatory period of the task. In the same way, a more important interaction was found between M1 and pre-SMA areas, which corroborates the assumption of the prevalent role played by these two areas in the case of a preparation task of a motor movement. Thus, this study has allowed highlighting a functional dissociation between the two portions of the SMA.

Value of phase contrast magnetic resonance imaging for investigation of cerebral hydrodynamics

OBJECTIVE

Phase Contrast Magnetic Resonance Imaging (PCMRI) is a noninvasive technique that can be used to quantify variations of flow during the cardiac cycle. PCMRI allows investigations of blood flow dynamics in the main arteries and veins of the brain but also the dynamics of cerebrospinal fluid. These cerebral flow investigations provide a description of the regulation mechanisms of intracranial pressure during the cardiac cycle. The objective of this paper is to describe the contribution of this technique in diseases related to disorders of cerebral hydrodynamics in the light of 5 clinical cases.

METHOD

Flow measurements were performed using PCMRI sequences on a 1.5 Tesla MR imager in 4 patients with symptomatic ventricular dilation and 1 patient with a syringomyelic cavity.

RESULTS

Flow quantification in these 5 patients, representative of the diseases mainly concerned by cerebral hydrodynamics, is useful to guide the indication for ventricular shunting in patients with hydrocephalus, to demonstrate obstruction of the cerebral aqueduct, to demonstrate recirculation of ventricular CSF after ventriculostomy and to characterize the dynamic features of CSF inside a spinal cavity.

CONCLUSION

PCMRI, now available to neurosurgeons, is complementary to morphological MR and provides quantitative information on cerebral hydrodynamics. This information is mainly used to confirm alteration of CSF flow in the cerebral and spinal compartments. PCMRI is also a functional tool to better understand the pathophysiology of hydrocephalus and syringomyelia.

[Cerebrospinal fluid flow imaging in the meningeal hemorrhage]

BACKGROUND AND PURPOSES

Cerebrospinal fluid (CSF) flow oscillations are synchronized with cerebral blood flow and are also involved in the control of variations of intracranial pressure during the cardiac cycle. The aim of this study was to investigate the possible alterations of CSF flow dynamics during the acute phase of meningeal hemorrhage (MH).

METHODS

Eleven patients with MH confirmed by computed tomography (CT) scan were examined by MR imaging, which comprised morphological sequences and flow dynamic sequences for quantification of CSF oscillations and cerebral blood flow rates. CSF oscillations were recorded at the cerebral aqueduct and C2-C3 subarachnoid space (SAS), where a vascular sequence was also performed to quantify artery blood flow. These results were compared to oscillations of a population of 44 control subjects and a difference of at least two standard deviation was used to define a hyperdynamic or hypodynamic appearance of CSF flow. Dilatation of the ventricular system was determined on radiographs by two neuroradiologists and a neurosurgeon.

RESULTS

Only four patients presented normal ventricular CSF flow, one patient presented hypodynamic flow and five patients presented hyperdynamic flow. Five patients had normal cervical CSF flow and five patients presented hyperdynamic flow. The two patients with ventricular dilatation both presented hyperdynamic ventricular CSF flow associated with normal cervical CSF flow. One patient was excluded.

CONCLUSION

Abnormal CSF flow dynamics were shown suggesting the hypothesis that bleeding increases intracranial volume and induces a reduction of cerebral compliance and an increase of intracranial pressure. The increased oscillations in the ventricular system would therefore predispose to dilatation.

Ventricular dilation as an instability of intracranial dynamics

We address the question of the ventricles' dilation as a possible instability of the intracranial dynamics. The ventricular system is shown to be governed by a dynamical equation derived from first principles. This general nonlinear scheme is linearized around a well-defined steady state which is mapped onto a pressure-volume model with an algebraic effective compliance depending on the ventricles' geometry, the ependyma's elasticity, and the cerebrospinal fluid (CSF) surface tension. Instabilities of different natures are then evidenced. A first type of structural instability results from the compelling effects of the CSF surface tension and the elastic properties of the ependyma. A second type of dynamical instability occurs for low enough values of the aqueduct's conductance. This last case is then shown to be accompanied by a spontaneous ventricle's dilation. A strong correlation with some active hydrocephalus is evidenced and discussed. The transfer function of the ventricles, compared to a low-pass filter, are calculated in both the stable and unstable regimes and appear to be very different.

Influence of age and osteoporosis on calcaneus trabecular bone structure: a preliminary in vivo MRI study by quantitative texture analysis

Recent developments in high-resolution MR imaging techniques have opened up new perspectives for structural characterization of trabecular bone by non-invasive methods. In this study, 3-D MR imaging was performed on 17 healthy volunteers and 6 osteoporotic patients. Two different MR sequences were used to evaluate the impact on MR acquisition on texture analysis results. Images were analyzed with four automated methods of texture analysis (grey level histogram, cooccurrence, runlength and gradient matrices) enabling quantitative analysis of grey level intensity and distribution within three different regions of interest (ROI). Texture analysis is not very frequently used since the interpretation of the large number of calculated parameters is difficult. We applied multiparametric data analyses such as principal component analysis (CFA) and hierarchical ascending classification (HAC) to determine the relevant parameters to differentiate between three sets of images (healthy young volunteers, healthy postmenopaused and osteoporotic patients). The results suggest that relevant texture information (depending on the ROI localization in the calcaneus) can be extracted from calcaneus MR images to evaluate osteoporosis and age effects on trabecular bone structure if strictly the same acquisition sequences are used for all patients' examination.

Neural correlates of implicit object identification

The present study sought to assess neural correlates of implicit identification of objects by means of fMRI, using tasks that require matching of the physical properties of objects. Behavioural data suggests that there is automatic access to object identity when observers attend to a physical property of the form of an object (e.g. the object's orientation) and no evidence for semantic processing when subjects attend to colour. We evaluated whether, in addition to neural areas associated with decisions to specific perceptual properties, areas associated with access to semantic information were activated when tasks demanded processing of the global configuration of pictures. We used two perceptual matching tasks based on the global orientation or on the colour of line drawings. Our results confirmed behavioural data. Activations in the inferior occipital cortex, fusiform and inferior temporal gyri in both tasks (orientation and colour) account for perceptual and structural processing involved in each task. In contrast, activations in the posterior and medial parts of the fusiform gyrus, shown to be involved in explicit semantic judgements, were more pronounced in the orientation-matching task, suggesting that semantic information from the pictures is processed in an implicit way even when not required by the task. Thus, this study suggests that cortical regions usually involved in explicit semantic processing are also activated when implicit processing of objects occurs.

Transmembrane and cytoplasmic domains of syndecan mediate a multi-step endocytic pathway involving detergent-insoluble membrane rafts

Syndecan heparan sulphate proteoglycans directly mediate a novel endocytic pathway. Using Chinese hamster ovary cells expressing the human syndecan 1 core protein or a chimaeric receptor, FcR-Synd, consisting of the ectodomain of the IgG Fc receptor Ia linked to the transmembrane and cytoplasmic domains of syndecan 1, we previously reported that efficient internalization is triggered by ligand clustering, requires intact actin microfilaments and tyrosine kinases, proceeds with a t(1/2) of approx. 1 h and is distinct from coated-pit pathways. We have now examined the involvement of cholesterol-rich, detergent-insoluble membrane rafts. On clustering, (125)I-labelled IgG bound to FcR-Synd rapidly became insoluble in cold Triton X-100, well before endocytosis. Insolubility of clustered FcR-Synd ligand did not require the syndecan ectodomain, linkage of the cytoplasmic tail to the cytoskeleton, or energy-dependent cellular metabolism. Pretreatment of cells with cyclodextrin to deplete cholesterol from rafts abolished insolubility of the clustered ligand and inhibited endocytosis in a dose-responsive fashion. Similar results were obtained with (125)I-labelled lipoprotein lipase bound to authentic cell-surface syndecan. In contrast, the 39 kDa receptor-associated protein (RAP), a coated-pit ligand, was more than 80% soluble in cold Triton even after internalization; cellular cholesterol depletion failed to substantially affect the internalization of (125)I-RAP. Overall, our results indicate a multi-step endocytic process consisting of ligand binding, clustering, energy-independent lateral movement into detergent-insoluble membrane rafts and finally recruitment of actin and tyrosine kinases to bring the ligands into the cell.

Automatic object identification: an fMRI study

Boucart and Humphreys reported an automatic access to object identity when observers attend to a physical property of the form of an object (e.g. the orientation) but not to its colour. We sought evidence for automatic identification in a brain imaging study using fMRI. In an orientation decision task participants decided whether a picture was vertical or horizontal. In the colour decision task participants decided if a picture was blue or green. Activation of areas 18-19 was found for both color and orientation. Activation of the temporal area 37 occurred more frequently in the orientation than in the colour decision task. This result suggests that automatic identification activates the same brain area as overt processing of semantic information.

The pitfalls of planar three-phase bone scintigraphy in nontraumatic hip avascular osteonecrosis

PURPOSE

This study documented the previously reported lower sensitivity of routine planar three-phase bone scintigraphy (BS) performed using a high-resolution parallel-hole collimator compared with MRI to diagnose nontraumatic avascular necrosis of the hip (AVN).

METHODS

Six observers reviewed 143 bone scintigrams obtained in patients with nontraumatic hip pain (n = 120) or a control group (n = 23). All patients had a standard radiograph and MRI within 2 months of the BS. Of 280 hips, 148 (53%) were painful on the day of the examination. The osteonecrosis group (AVN) consisted of 93 instances of AVN in 58 patients. Although it departs from the clinical situation, this method evaluated the intrinsic performance of the imaging method. The data were analyzed using a receiver operating characteristic method.

RESULTS

For the six observers, the A(z) values were 0.65, 0.67, 0.66, 0.67, 0.73, and 0.79, respectively, and 0.66, 0.71, 0.75, 0.81, 0.81, 0.82, and 0.84 after removing hip diseases other than AVN through data manipulation. Bone marrow edema, as seen on MRI, was the most frequently reported misleading sign in false-positive diagnoses, especially in the early or late phases of the disease. False-negative diagnoses misclassified the scans as "asymptomatic hips" in 28 of 30 cases. Twenty-two of 30 scans appeared normal, but these AVN lesions were small (<25%) and were discovered by chance on MRIs that displayed bilateral involvement associated with radiographic evidence (stage 0 or 1). Thirteen of 20 patients were followed for 3 or more years, and only one worsened.

CONCLUSIONS

BS is not indicated to diagnose possible contralateral AVN if the hip is asymptomatic. This study emphasizes the results from the literature; if indicated, a radionuclide hip investigation requires the use of a pin-hole collimator, a SPECT study with scatter correction and iterative reconstruction algorithms, or both.

Mesolimbic 7-OH-DPAT affects locomotor activities in rats

This study tested the hypotheses that the dopamine D3 receptor is both an autoreceptor and a postsynaptic receptor and has an affinity for dopamine at the nanomolar level. The effect of bilateral microinjections of a dopamine D3-like agonist, 7-OH-DPAT, into the nucleus accumbens and into the ventral tegmental area (VTA) was tested with rats in activity monitors. Horizontal movement, rearing, and stereotypy times in seconds were automatically measured during 12 consecutive 10-min time blocks. Intraaccumbens 7-OH-DPAT (0.0001-10.0 micrograms/side) resulted in a highly significant dose by time block interactions. The dose of 0.0001 microgram/side resulted in the potentiation of horizontal movement time during the time blocks 10-40 min; whereas, 0.001-1.0 microgram/side potentiated locomotion during the early blocks following the 10-min interval. However, 10.0 micrograms/side resulted in a biphasic effect, attenuation followed by potentiation. 7-OH-DPAT (0.0001-1.0 microgram/ side) potentiated rearing time in the early time blocks and (0.001-10.0 micrograms/side) attenuated stereotypy time during the first 20 min time blocks. On the other hand, intra-VTA 7-OH-DPAT (10.0 micrograms/side) attenuated horizontal movement time during the first 20-min time blocks and (0.01 and 0.0001 microgram/side) potentiated movement time at the 20-min time block. Intraventral tegmental area 7-OH-DPAT had no effects on rearing and stereotypy times. These data support the hypothesis that the D3 receptor has an affinity for dopamine at the nanomolar level and question the hypothesis that the D3 receptors are both autoreceptors and postsynaptic receptors.

NMR relaxation rates and blood oxygenation level

A linear relationship between the proton relaxation rates and the fraction of deoxyhemoglobin of circulating whole blood (fHb) has been established in vitro at 4.7 T. These results have been interpreted on the basis of the additivity of relaxation rates. The slope of the lines of transverse relaxation rates (R2) versus fHb was found to increase with interpulse delay in Carr-Purcell Meiboom-Gill (CPMG) experiments. The Luz-Meiboom relation applied to this interpulse delay dependence of R2 suggests a two-site chemical exchange rather than a diffusion mechanism. The 1-ms water proton exchange time derived from these observations has been interpreted in terms of exchange between exchangeable protons close to the paramagnetic center of hemoglobin and protons of bulk water.

Intra-accumbens delta 1-opioid agonist, pC1-DPDPE, differentially affects patterns of locomotor activity

The effects of bilateral microinjections of a new potent and highly selective delta-opioid receptor agonist pCl-DPDPE (0.00, 0.1, 1.0, or 2.5 micrograms/side) were tested in rats for 60 min in activity monitors. The durations of horizontal movement time, rearing time, and stereotypy time were measured during six consecutive 10-min time blocks. The pCl-DPDPE resulted in short-lived biphasic effects of attenuation followed by potentiation for the three measures. These data in part replicate the behavioral effects of other delta-opioid receptor agonists.

DALDA (H-Tyr-D-Arg-Phe-Lys-NH2), a potent mu-opioid peptide agonist, affects various patterns of locomotor activities

The central effects of mu-opioid receptor agonist DALDA (ICV 0.00, 0.1, or 1.0 micrograms) were investigated in rats for 120 min on activity monitors. The durations in seconds of horizontal movement time, rearing time, and stereotypy time were measured during 12 consecutive 10-min time blocks. DALDA (ICV, 0.1 and 1.0 micrograms) resulted in biphasic effects, inhibition followed by activation for horizontal movement, rearing, and stereotypy times.

Ontogeny of biphasic locomotor effects of quinpirole

The effects of the dopamine D2/D3 receptor agonist quinpirole (LY171555) on locomotor activity were tested on rats of 10, 15, 20, 30, and 60 days of age. In two separate experiments, doses of 0 (vehicle), 0.02, 0.2, or 2.0 mg/kg quinpirole were injected SC into rats at each age, and their effects measured either for 2 h at 15-min intervals, or 30 min at 5-min intervals. At 10, 15, and 20 days of age, quinpirole significantly increased distance travelled in a dose-dependent manner. At 30 and 60 days of age, quinpirole significantly decreased distance travelled early in the session and increased it later. These results suggest that a dopamine autoreceptor begins to function between 20 and 30 days of age. Concomitant with the appearance of quinpirole-induced locomotor suppression early in the session, the amount of quinpirole-induced activation late in the session declined.

Biphasic effects of intraaccumbens mu-opioid peptide agonist DAMGO on locomotor activities

The effects of bilateral microinjections of mu-opioid receptor agonist DAMGO (0.00, 0.01, 0.1, or 1.0 microgram/side) were tested in rats for 120 min in activity monitors. The horizontal movement, rearing, and stereotypy times in seconds were measured during 12 consecutive 10-min time blocks. DAMGO (0.01, 0.1, and 1.0 microgram) resulted in biphasic effects, inhibition followed by activation for each of the three measures. These data replicate the behavioral effects of ICV DAMGO except that the duration of the behavioral effects were longer with Acb injections.

The effects of methionine-enkephalin and its related metabolites upon the duration of the dorsal immobility response in rats

The effects of SC injections of methionine-enkephalin (Met1-5-Enk) and its N-terminal and C-terminal fragments upon the duration of the dorsal immobility response (DIR) over a 60-min time course were investigated. Experiment 1 analyzed the effects of various dosages (0.00-100.0 micrograms/kg) on DIR resulting in a potentiation of the duration in a dose-time course function. The effects of various fragments of Met1-5-Enk (10.0 micrograms/kg) from the N-terminal in Experiment 2 and from the C-terminal in Experiment 3 on the DIR resulted in the potentiation of the duration with the Met2-5-Enk and Met1-3-Enk fragments. All other fragments were not significant. The results were discussed in reference to the processing and metabolism of Met1-5-Enk.

Dopamine D1 receptor family agonists, SK&F38393, SK&F77434, and SK&F82958, differentially affect locomotor activities in rats

Dopamine D1 receptor family agonists, 2,3,4,5,-tetrahydro-7,8-dihydroxy-1phenyl-1H-3-benzazepine (SK&F38393), 3-allyl-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine (SK&F77434), and 3-allyl-6-chloro-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazep ine (SK&F82958), were compared for their behavioral effects on horizontal movement time, rearing time, stereotypy time, and thigmotaxis time. All agonists resulted in biphasic effects with attenuation followed by potentiation (0.01-10.0 mg/kg, SC). While SK&F38393 did not potentiate horizontal movement and rearing times, and had minor effects on thigmotaxis, SK&F77434 and SK&F82958 potentiated horizontal movement and rearing behaviors and attenuated thigmotaxis. The results were discussed in terms of the binding characteristics and current receptor theory.

Behavioral effects of the mu-opioid peptide agonists DAMGO, DALDA, and PL017 on locomotor activities

The relative role of central mu-opioid receptor agonists Tyr-D-Ala-Gly-N-Methyl-Phe-Gly-ol (DAMGO), Tyr-D-Arg-Phe-Lys (DALDA), and Tyr-Pro-MePhe-D-Pro (PL017) (0.00, 0.01, 01, or 1.0 micrograms, ICV) on behavior was investigated in rats for 60 min in activity monitors. DAMGO (0.1 and 1.0 micrograms) and PL017 (1.0 micrograms) resulted in biphasic effects, inhibition followed by hyperactivity for linear locomotor, whereas the 0.01-micrograms dosage was associated with hyperactivity. On the other hand, DALDA (0.1 and 1.0 micrograms) suppressed locomotor activity over the 60-min session.

Differential effects of SCH 23390 on immobility behaviors in developing rats

The effects of a single injection of a dopamine D1 antagonist, SCH 23390, at doses of 0, 0.05, 0.1, and 0.2 mg/kg on three different kinds of immobility behavior were tested in rats of 10, 15, 20, and 30 days of age. Each animal was tested for the dorsal immobility response (DIR), vertical cling catalepsy, and bar catalepsy. A different pattern of results was found for each of the three immobility behaviors. SCH 23390 significantly increased the DIR at each age except 15 days; there was a progressive increase in effect from 10 to 20 to 30 days of age. At the lowest dose, drug-induced bar catalepsy peaked at 15 days of age and declined at 20 and 30 days of age. The effect of SCH 23390 on vertical cling catalepsy increased with age, plateauing at 20 days. Thus, the developmental pattern of immobility responses to this dopamine D1 antagonist differs with each behavior measured.

Effects of intraaccumbens dopamine agonist SK&F38393 and antagonist SCH23390 on locomotor activities in rats

The present study examined the effects of the dopamine D1 and D5 subtype receptors agonist, R(+)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol (SK&F38393), and antagonist, R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-ben zaz epine (SCH23390), on locomotor activities after bilateral microinjection into the nucleus accumbens (Acb). SK&F38393 (0.1-10.0 micrograms) significantly potentiated and SCH23390 (0.01-1.0 microgram) significantly attenuated locomotor activity as measured by horizontal distance in cm. The data were supportive of the hypothesis that dose-related locomotor activities induced by microinjections of SK&F38393 into the Acb are independently mediated by D1 and D5 subtype receptors.

Somatosensory pressure affects immobility and grasping reactions in bilateral labyrinthectomized rats

The effects of dorsal clip pressure and proprioceptive plate pressure to soles of the feet on tonic immobility; dorsal clip pressure on contact righting, horizontal bar, and vertical cling; forepaw and slope board grasp reactions were investigated in bilateral labyrinthectomized (BL) rats. Both dorsal and proprioceptive pressures potentiated the duration of tonic immobility in BL animals whereas only the dorsal pressure affected the controls. Dorsal pressure potentiated the duration of the horizontal bar, vertical cling, and slope board grasps in both the control and BL group. However, the behavioral patterns were different. The BL animals had weak grasp reactions and with the dorsal clip, emitted "head-back fall" during the vertical cling and slope board grasp conditions. The results were discussed in terms of the tactile and vestibular interactions and control on the postural mechanisms.

Behavioral effects of opioid peptide agonists DAMGO, DPDPE, and DAKLI on locomotor activities

The effects of the mu-selective agonist DAMGO (ICV doses of 0.00, 0.01, 0.1, or 1.0 micrograms), the delta-selective agonist DPDPE (ICV doses of 0.00, 0.1, 1.0, or 10.0 micrograms), and the kappa-selective agonist DAKLI (ICV doses of 0.00, 0.01, 0.1, or 1.0 micrograms) were tested in rats for 60 min in an activity monitor. The durations in seconds of linear locomotor time, rearing time, stereotypy time, and margin time (thigmotaxis) were measured during six 10-min time blocks. DAMGO (0.1 and 1.0 micrograms) resulted in biphasic effects, inhibition followed by hyperactivity for linear locomotor, rearing, and stereotypy times, and an inhibition of thigmotaxis. DPDPE (10.0 micrograms) was associated with monophasic potentiation of linear locomotor activity and mixed effects in stereotypy times. DAKLI did not effect horizontal, rearing, or margin times; only stereotypy times resulted in mixed effects of DAKLI. The differential behavioral profiles were discussed in reference to the three opioid receptor subtypes.

Biphasic effects of dopamine agonist N-0434 on locomotor behaviors in rats

The effects of a dopamine agonist, (+/-)-2-(N-penylethyl-N-propyl)amino-5- hydroxytetralin (N-0434) (SC doses of 0.00, 0.01, 0.1, and 1.0 mg/kg) were tested in rats for 120 min in an activity monitor. The durations in seconds of horizontal locomotor time, rearing time, stereotypy time, and margin time (thigmotaxis) were measured during 12 10-min time blocks. N-0434 (0.1 and 1.0 mg/kg) resulted in biphasic effects (initial inhibition followed by potentiation) of linear locomotor time and an attenuation of thigmotaxis. The 0.1- and 1.0-mg/kg doses initially suppressed rearing time but had mixed potentiation effects. The 0.01- to 1.0-mg/kg doses suppressed stereotypy time. The differential behavioral profiles were discussed in reference to the functions of dopamine receptors.

Behavioral effects of long-term administration of an anabolic steroid in intact and castrated male Wistar rats

Once a week, intact and castrated male Wistar rats were intramuscularly injected with a 0.2 ml suspension of either 0, 10, or 50 mg nandrolone decanoate in cottonseed oil, for 8 consecutive weeks. After the sixth injection, locomotor activity was measured in an open-field and the acquisition of lever press behavior was assessed in an autoshaping procedure. Subsequently, all subjects were exposed to four sessions of continuous reinforcement prior to one session in which the effects of steroid administration on extinction were assessed. Locomotor activity decreased for all groups of rats with continued exposure to the open-field, differences between groups were not observed. Rats treated with the highest dose of nandrolone decanoate spent more time in the margin of the open-field. There were no significant differences between groups on any of the learning measures. Long-term, high-dose steroid administration in conjunction with mild food deprivation inhibited growth in intact and castrated rats, while low dose administration affected body weight in intact rats only. Steroid administration resulted in heavier and enlarged kidneys and lighter testes as well. These results suggest that the administration of anabolic steroids not only produces observable physiological changes, but that it may also affect spontaneous behavior. The failure to find differences in learning indices may have been a function of the particular paradigms used in the present experiment.

Locomotor activity following intra-accumbens microinjections of dopamine D1 agonist SK&F 38393 in rats

The present study examined the effects of the dopamine D1 receptor subtypes agonist SK&F 38393 on locomotor activities after bilateral microinjection (0.00, 0.01, 0.1, 1.0, 10.0 micrograms) into the nucleus accumbens (Acb). The dose of 0.1 microgram elicited the highest response rate across measures of locomotion, rearing and stereotypy behavior. On the other hand, the largest dose of 10.0 micrograms was associated with significant increase in center time behaviors. The data were supportive of the hypothesis that dose-related locomotor activities elicited by microinjections of SK&F 38393 into the Acb are independently mediated by D1 receptors.

Intrastriatal injections of dynorphin A fragments potentiate the dorsal immobility response in rats

The effects of bilateral intrastriatal injections (2.0 micrograms/side) of Dynorphin A 1-17 (Dyn A 1-17) and Dynorphin A 1-8 (Dyn A 1-8) and their related nonopioid fragments upon the dorsal immobility response (DIR) over a 1-h time course were investigated. Dyn A 1-17 and Dyn A 2-17 potentiated the duration of the DIR 5 min postinjection, whereas Dyn A 1-8 and Dyn A 2-8 potentiated the DIR duration at each time point over the hour with their greatest effect at 15 min. An SC injection of 4 mg/kg naloxone 15 min prior to central injections blocked the potentiation of the DIR effects of Dyn A.

Effects of dopamine D1 antagonists SCH23390 and SK&F83566 on locomotor activities in rats

The effects of the dopamine D1 antagonists R-(+)-7-chloro-8-hydroxy-3-methyl-1phenyl-2,3,4,5-tetrahydro-1-H-3 -benzazapine (SCH23390) and (+-)-7-bromo-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1- H-3-benzazapine (SK&F83566) were tested for 2 h on linear locomotor, rearing, stereotypy, and margin times in an open field. Each of the antagonists attenuated the duration of linear locomotion, rearing, and stereotypy times in a dose- and time-dependent manner. The effectiveness of the antagonists was relatively brief and SCH23390 was more effective than SK&F83566 on each behavior. The two antagonists had differential effects on margin time.

Intracerebral haloperidol potentiates the dorsal immobility response in the rat

The effects of intracerebral microinjections of 4-[4-(4-chlorophenyl)-4-hydroxy-1-piperidinyl]-1-(4- fluorophenyl)-1-butanone (haloperidol) (1.0 microgram, 0.5 microliter) in five regions of the brain were tested on the duration of the dorsal immobility response (DIR) and the cling and bar catalepsy in the rat. The duration of the DIR was significantly potentiated (but not the cling and bar catalepsy) following 2-h postinjection of haloperidol in the caudate putamen, nucleus accumbens, and globus pallidus but not in the substantia nigra pars compacta or cortex. These data further expand the previous evidence of regional variations in dopamine to the effects upon inhibitory behaviors.

Differential effects of intrastriatal estradiol on the dorsal immobility response in male rats

The effects of implants of 17 beta-estradiol and cholesterol in four regions of the dorsal striatum were tested on the duration of the dorsal immobility response in gonadectomized male rats. The dorsal immobility response was significantly potentiated by 4-h implants of 17 beta-estradiol in the dorsomedial and dorsolateral regions of the dorsal striatum but not in the ventromedial and ventrolateral regions. These data further support the growing evidence that estradiol acts directly but differentially on the striatum to affect behaviors in the rat.

Potentiation of the dorsal immobility response following intrastriatal injections of enkephalins

The effects of bilateral intrastriatal injections (1.0 microgram/side) of leucine5- and methionine5-enkephalins and their related nonopiate fragments upon three measures of immobility over a time course were investigated. Both leucine5-enkephalin and des-Tyr1-leucine-enkephalin potentiated the duration of the dorsal immobility response (DIR) 15 min postinjection and over a 1-h time course. On the other hand, methionine5-enkephalin and des-Tyr1-methionine-enkephalin potentiated the duration of the DIR at 5 and 15 min. These enkephalins and their fragments had no effect upon vertical cling and bar catalepsy. In a second study, an SC injection of 4 mg/kg naloxone 15 min prior to the central injections blocked the potentiation of the DIR effects of the enkephalins.

Differential effects of dopamine D2 agonist quinpirole upon the dorsal immobility response in rats

The effects of various dose levels of systemically injected quinpirole upon the dorsal immobility response (DIR) over a time course was investigated in male rats. A low dose of quinpirole (0.01 mg/kg) significantly attenuated the duration of the DIR following the 10-min interval, whereas the highest dose (1.0 mg/kg) had a biphasic effect so that at the 10-min interval the duration of the DIR was significantly potentiated and at the 60-min interval the duration of the DIR was significantly attenuated. The intermediate dose (0.1 mg/kg) had intermediate behavioral effects. The data support the growing evidence that quinpirole has differential effects upon behavior over time as a function of the dose levels. The present data were discussed in reference to presynaptic and postsynaptic dopamine D2 receptor theory.

A limiting factor mediates the differential activation of promoters by the human progesterone receptor isoforms

The two transcription activation functions (TAFs) of the human progesterone receptor (hPR) have been characterized. TAF-1, located in the N-terminal region A/B, has been narrowed down to a 91-amino acid sequence, which is sufficient for transcription activation in chimeras with the GAL4 DNA binding domain. Both hPR TAF-1 and TAF-2 activate a minimal promoter in yeast. No autonomous TAF could be found in the N-terminal 164 amino acids (designated AB3) which are responsible for the differential activation of promoters by the hPR isoforms A and B. Reduction of the target gene promoter complexity did not alter this differential activation, indicating that AB3 does not require additional promoter-bound factors to exert its effect. Instead, the cell specificity of AB3 and its ability to squelch hPR-induced transcription suggest that this differential isoform activity is due to the effect of a limiting factor which binds to region AB3.

Effects of intracerebral quinpirole on locomotion in rats

The effects of the dopamine D2 receptor agonist quinpirole (LY 171555) on locomotor activity and margin time (thigmotaxis or wall-hugging) were measured for 2 h in rats injected either s.c. (vehicle, 0.02, 2.0 mg/kg) or directly into either the dorsal striatum or nucleus accumbens (vehicle, 0.1, 1.0, 10, 20 or 40 micrograms bilaterally in each site). In all groups, margin time decreased as drug dose increased. As in previous research, quinpirole given s.c. decreased locomotor activity at a low dose and had a biphasic effect on locomotor activity at the high dose. Both of these effects were also elicited by quinpirole injected directly into the dorsal striatum; 10 and 20 micrograms decreased locomotion immediately, while 40 micrograms led to both the immediate decrease and a later increase. In contrast, the lowest doses of quinpirole (0.1 and 1.0 microgram) injected into the nucleus accumbens led to an increase in locomotion from 20 to 60 min, while the higher doses led only to the early decrease. Thus, both the locomotor activating and inhibiting effects of quinpirole are found in both the nucleus accumbens and the dorsal striatum, but the differing dose-response relationships indicate that the mechanisms are not the same in these two brain regions.

The effects of bilateral and unilateral vibrissotomy on behavior within aquatic and terrestrial environments

Introducing an untreated rat to a novel environment typically results in thigmotaxis or wall-seeking behavior and the unilateral removal of the vibrissae induces an asymmetry in thigmotaxis. The present study investigated the effects of bilateral and unilateral removal of the vibrissae (vibrissotomy) upon the rat exhibiting thigmotaxis within aquatic and terrestrial environments. Unilateral vibrissotomy resulted in directional thigmotaxis asymmetry toward the intact vibrissae side within both environments. Within the aquatic environment, the unilateral vibrissotomy group swam a significantly longer distance than the other two groups. The data are discussed in terms of activation and sensory information.

Dopamine D1 antagonists potentiate the durations of bar and cling catalepsy and the dorsal immobility response in rats

The effects of dopamine D1 antagonists SCH 23390 or SK&F 83566 (at SC doses of 0.00, 0.01, 0.05, and 0.1 mg/kg) were tested for 2 h on bar and cling catalepsy and the dorsal immobility response. Each of the drugs potentiated the duration of each of the three measures of immobility in a dose- and time-dependent manner. Each of the drugs had rapid but brief effects on all three response measures; the peak effect of SK&F 83566 took place at 20 min and that for SCH 23390 at 40 min for each behavior. At each effective drug dose, SCH 23390 had a greater effect than SK&F 83566 on each behavior. Dopamine D1 antagonists potentiated three different immobility responses, as do dopamine D2 antagonists.

Mechanisms of antihormone action

The mechanisms of action of two types of anti-hormones is discussed. Type I anti-hormones comprise the antiestrogen hydroxy-tamoxifen and the antiprogestin RU486, both of which promote DNA binding of the cognate receptors and, due to the activity of one of the two transcription activation functions of the estrogen and progesterone receptors, act as mixed agonist/antagonists. Evidence supporting that ICI 164,384 is also a member of the same group is presented. Type II antagonists impair DNA binding of the corresponding receptor in vitro and, in some cases, also in vivo. Ligand-mapping, an approach to identify the site of interaction of a steroid substitution within the hormone-binding domain of the receptor has been used to identify the 11 beta-pocket of the progesterone receptor and revealed that a single amino acid is responsible for the differential antagonistic effect of RU486 in man, chicken and hamster.

Sex differences in locomotor activity after acute and chronic cocaine administration

Adult, intact and gonadectomized male and female Wistar rats (n = 9) were exposed to an automated open field to assess the behavioral effects of acute cocaine administration (saline, 1.0 and 10.0 mg/kg subcutaneous). The subjects were exposed to the open field for 10 min, removed to be injected and returned to the open field for another 30 min. Three saline and two drug sessions were run in counterbalanced order. Locomotor activity in intact and castrated male rats and ovariectomized female rats decreased following injection, irrespective of the dose of cocaine. The locomotor activity of intact female rats was higher than that of any other group of subjects. It decreased during the session after saline and 1.0 mg/kg cocaine, but increased towards the end of the 30 min session after 10.0 mg/kg. Rearing measures paralleled the observations on locomotor activity. To determine the effects of chronic, home-cage, cocaine administration, five of the subjects in each group were injected with 10.0 mg/kg cocaine for 9 consecutive days. The remaining four subjects received saline injections. On day 10, all subjects were re-exposed to the open-field for 10 min, removed, injected with 10.0 mg/kg cocaine and returned to the open field for another 30 min. Chronic home cage cocaine administration produced an increase in cocaine's effects on locomotor activity and rearing in intact female rats only. However, behavioral sensitization was also observed in intact female rats who had been treated with saline for 9 consecutive days, suggesting that behavioral sensitization to cocaine in intact female rats may develop very rapidly and independent of environmental context.

Progestin receptors: isoforms and antihormone action

We present evidence that the two isoforms of A and B of the chicken (cPR) and human progesterone receptor (hPR) originate from two different mRNA populations. One of these encodes the isoforms A which originate by initiation of translation at an in-frame AUG found 127 (cPR) and 165 (hPR) codons downstream of the AUG which gives rise to the isoforms B. Two estrogen-inducible hPR promoters were identified which are responsible for the generation of these two classes of transcripts. Characterization of the cPR promoter suggested the possible existence of cell-type and isoform-specific auto-regulation of cPR transcription and provided evidence that estrogen-induction of cPR expression occurs at a post-transcriptional level. Finally, we demonstrate promoter-specific transcriptional activation by the hPR isoforms A and B, and we discuss the mechanism of action of the anti-progestin RU486.

Agonistic and antagonistic activities of RU486 on the functions of the human progesterone receptor

RU486 induced the binding to a palindromic progestin responsive element (PRE) in vitro of homo- and heterodimers of the human progesterone receptor (hPR) isoforms A and B, present in T47D breast cancer cells or in HeLa cells transiently expressing the recombinant proteins. The resulting complexes were indistinguishable from those induced with the agonist R5020 with respect to specificity, affinity and stability. Ligand exposure was a necessary prerequisite to observe PR/PRE complexes. Antagonist-induced complexes migrated more rapidly during electrophoresis than agonist-induced ones, and no 'mixed' PR/RU486-PR/R5020 complexes were observed, suggesting that the dimerization interfaces of agonist- and antagonist-bound molecules are non-compatible. The analysis of a series of deletion mutants and chimeric receptors revealed the presence of two transcription activation functions (TAFs), located in the N-terminal region A/B (TAF-1) and the hormone binding domain (TAF-2). In the presence of agonists, both TAFs were active in HeLa cells. In the presence of RU486 TAF-2 was inactive, while TAF-1 within the hPR form B/RU486 complex activated transcription from a reporter gene containing a single palindromic PRE. We consider this to be the most convincing evidence that the receptor/RU486-complex does in fact bind to PREs in vivo. No transcriptional activation was observed in the presence of RU486 from a reporter gene containing the complex MMTV-LTR PRE. In contrast to hPR form B, form A was not able to activate transcription from PRE/GRE-tk-CAT in the presence of RU486. In vivo competition between hPR/RU486 and either cPR/R5020 or the human glucocorticoid receptor/dexamethasone (hGR/Dex) complex further supported that hPR/RU486 bound in vivo to its cognate responsive element. Indeed, the observed inhibition of transcription was shown to be due to competition for the MMTV PRE, since no transcriptional interference by the hPR/RU486 was observed, and since no heterodimers were formed between hPR/RU486 and cPR/R5020 or hGR/Dex. That the ligand-free hPR, however, was unable to compete, demonstrated that ligand binding is the prerequisite for DNA binding of hPR in vivo.