Knowledge, Attitudes, and Practices of European Healthcare Professionals towards Hepatitis A and Hepatitis B Vaccination in at-Risk Adults

Despite the occurrence of several hepatitis A (hepA) and hepatitis B (hepB) outbreaks in Europe in the last few decades, not all European countries have implemented hepA and hepB vaccinations in their national immunization programs, especially for adults at risk for hepA and/or hepB infection, such as men who have sex with men or patients with chronic liver disease. Currently, little is known on the attitudes of European healthcare professionals (HCPs) towards hepA and hepB vaccinations for at-risk adults. We conducted an online survey among HCPs in Germany, Spain, and the United Kingdom to assess their awareness of and adherence to their national hepA and hepB vaccination guidelines for at-risk adults. Among the 698 HCPs who took the survey, most (91.1%) were familiar with their national vaccination recommendations and always followed them or followed them most of the time when advising or prescribing hepA or hepB vaccines. Major and moderate barriers for recommending or administering such vaccines were the non-disclosure of risk factors by the patient (53.0-57.6%) and the patient's lack of motivation or knowledge about the risk of the disease (50.3-52.9%). These results may help inform strategies to improve and accelerate hepA and hepB vaccination in European at-risk adults.

Baseline characteristics from a retrospective, observational, US-based, multicenter, real-world (RW) study of avelumab first-line maintenance (1LM) in locally advanced/metastatic urothelial carcinoma (la/mUC) (PATRIOT-II)

465

Background: The JAVELIN Bladder 100 clinical trial demonstrated a significant overall survival and progression-free survival benefit with avelumab 1LM + best supportive care (BSC) vs BSC alone for la/mUC not progressing on platinum-based chemotherapy (PBC). PATRIOT-II aims to describe RW data for avelumab 1LM treatment (tx) of patients (pts) with la/mUC. Methods: PATRIOT-II collected data from pts with la/mUC treated in 37 geographically dispersed oncology practices/communities and academic centers in the US. Pts who initiated avelumab 1LM following PBC were retrospectively enrolled and will be followed up via medical record review for 52 weeks post avelumab 1LM initiation. This analysis focused on pt characteristics and tx data from la/mUC diagnosis through the PBC period and at avelumab 1LM initiation. Disease and PBC tx characteristics, as well as response to PBC, were assessed. All analyses were descriptive. Results: A total of 160 pts were enrolled (Table), 118 (74%) were white, non-Hispanic, 16 (10%), were Black, Asian, or Hispanic, and the rest unknown; 102 (64%) were current or former smokers. 77 (48%) were tested for PD-L1 via various assays, with 44 (57%) of those tumor samples reported as positive. 1L PBC was cisplatin-based in 100 (63%) of pts and carboplatin-based in 60 (38%). Pts received a median of 4 PBC cycles (interquartile range [IQR], 3-6) for a median of 13 weeks (IQR, 10-17). 31 (19%) discontinued PBC due to unacceptable side effects/toxicity. Best observed response was complete response in 21 (13%), partial response in 109 (68%), and stable disease in 17 (11%), with the remainder unknown. Median time to first imaging was 10 weeks (IQR, 5-14) after PBC initiation. 23 (14%) were hospitalized while receiving PBC, and 25 (16%) were seen in the emergency department. Pts proceeded to avelumab 1LM at a median of 4 weeks (IQR, 3-6) following PBC completion. Avelumab was administered at 800 mg every 2 weeks in 130 (81%), 10 mg/kg in 15 (9%), <800 mg in 8 (5%), and >800 mg in 7 (4%) pts. Conclusions: This ‘RW’ study offers valuable insights into characteristics and outcomes of pts with la/mUC treated in the US. Baseline factors, tx patterns and response to PBC were consistent with usual therapy paradigms in the 1L induction setting. Ongoing trials are evaluating the optimal number of PBC cycles and predictive biomarkers. Limitations include the retrospective nature, lack of randomization and central review, potential selection and confounding biases. [Table: see text]

Berberine mediates tumor cell death by skewing tumor-associated immunosuppressive macrophages to inflammatory macrophages

BACKGROUND

Berberine is a plant-derived alkaloid with potent anti-cancer activities. Berberine may redirect the tumor-promoting immunosuppressive M2 macrophages, to tumoricidal activated M1 macrophages. But such an anti-tumor function remains to be demonstrated.

HYPOTHESIS

Polarization of macrophages to an immunosuppressive phenotype within the tumor microenvironment promotes tumor growth and contributes to resistance to chemotherapy. We examined if berberine would target macrophage polarization to reinstate anti-tumor immune response.

STUDY DESIGN

Using a B16F10 mouse melanoma model, we assessed berberine-induced re-polarization of immunosuppressive M2 macrophages to anti-tumor M1 macrophages and subsequent T-cell activation within the immunosuppressive tumor microenvironment.

METHODS

The B16F10 culture supernatant along with tumor antigen was used as tumor mimicking conditioned medium (CM). The bone marrow-derived macrophages were cultured in CM for 5 days. The CM-induced skewing of macrophages to M2-like phenotype was confirmed by flow cytometry and ELISA. The T-cells were co-cultured with macrophages to decipher the effect of berberine on T-cell differentiation. In vivo efficacy of berberine was analyzed using melanoma model of solid tumor.

RESULTS

Berberine inhibited rIL-6-induced STAT-3 phosphorylation and IL-10 release from B16F10 cells. It enhanced tumor antigen-induced IL-1β, IL-12 and TNFα, but suppressed IL-6 and TGF-β release. Berberine significantly prevented the tumor antigen-mediated IL-10-enhanced IL-6 and TGF-β expression. The CM skewed the bone marrow-derived macrophages to CD206-high but MHC-II-low M2-like tumor-associated macrophages. Berberine partially prevented the generation of these macrophages and was associated with reduced C/EBPβ and Egr2 mRNA expression and lowered IL-10 and TGF-β production. Berberine significantly reduced Arginase-1 expression in CM-treated M1 and M2-like macrophages. Berberine increased MHC-II and CD40 expression on the macrophages augmenting the CTL activity and the number of IFNγ-producing CD4+ T-cells. Berberine significantly lowered tumor volume, weight and enhanced the frequency of M1-like macrophages in mice.

CONCLUSION

These data indicate that berberine interferes with pro-tumor macrophage polarization and IL-10 and TGF-β release but restores Tcell anti-tumor cytotoxicity in the tumor microenvironment.

PATRIOT II: An ambispective, observational, multicenter, 2-cohort study of avelumab (Ave) first-line maintenance (1LM) in locally advanced/metastatic urothelial carcinoma (la/mUC) in the United States

TPS578

Background: The randomized phase 3 JAVELIN Bladder 100 trial demonstrated overall and progression-free survival (OS and PFS) benefit with Ave 1LM for la/mUC not progressed with platinum-containing chemotherapy (PCT). PATRIOT II aims to understand real-world treatment (tx) patterns, patient-reported outcomes (PRO), and healthcare resource utilization (HCRU; eg, hospitalizations and emergency department visits) before and during Ave 1LM treatment. Methods: PATRIOT II is an ongoing, real-world, observational study in ≤25 US oncology centers with 1) an ambispective cohort of patients (pts) initiating PCT (n = 100), a subset of whom may continue to Ave 1LM and 2) a retrospective cohort initiated on Ave 1LM (n = 150). Sample size assumes noninferiority in HCRU and PRO pre and post 1LM initiation using paired t-tests with effect size of ≤0.3 as noninferior: ≥71 patients continuing to 1LM. In the ambispective cohort, pts with histologically confirmed la/mUC newly initiating 1L PCT are enrolled. While pts are receiving PCT and 1LM (for those who receive it), data will be collected on disease characteristics, response to tx, survival, adverse events (AEs), and HCRU for ≤52 wks after study initiation. PROs are captured using Rand SF-36 question 1, FACT Bladder Symptom Inventory – 18 and Cancer Treatment Satisfaction Questionnaire. Primary outcomes include OS and PFS from both PCT and 1LM initiation; secondary outcomes are changes in PROs and HCRU from PCT to 1LM. Analysis will be conducted at following time points: 1) baseline characteristics after full enrollment; 2) 6 months after study initiation to assess tx changes and rationale, OS, PFS, HCRU, and PRO changes from baseline; 3) at study conclusion (wk 52 after study initiation). In the retrospective cohort, pts with la/mUC who initiated Ave 1LM are enrolled. Chart data encompasses PCT and 1LM periods. Disease characteristics, response to tx, survival, AEs, and HCRU are collected. Primary outcomes are OS and PFS from initiation of PCT and 1LM start. Secondary outcomes are changes in HCRU before and after 1LM. Analysis will be conducted at following time points: 1) baseline characteristics after full enrollment, PCT, and response to tx; 2) 6 months after study initiation to assess tx changes since baseline, including dose changes, tx discontinuation/change rationale, survival rates (censoring for differential duration of follow-up), and HCRU outcomes; 3) at study conclusion to analyze endpoints up to wk 52 following study initiation. Analyses for both cohorts include Kaplan-Meier and Cox regression for time-to-event endpoints and paired t-tests for pre/post 1LM. Enrollment commenced in June 2021. 5 and 18 pts are enrolled to date in the ambispective and retrospective cohorts, respectively, from 6 of 11 activated sites. Initial results are anticipated in May 2022.

Health-related quality of life (QoL) in patients with advanced melanoma receiving immunotherapies in real-world clinical practice settings

Background

Pembrolizumab (PEMBRO) and ipilimumab + nivolumab (IPI + NIVO) are approved advanced melanoma (AM) immunotherapies. To address limited health-related quality of life (QoL) real-world evidence with immunotherapies in AM, we compared QoL in AM patients receiving either treatment in clinical practice.

Methods

A prospective US observational study enrolled adult AM patients initiating first-line PEMBRO or IPI + NIVO between June 2017 and March 2018. Endpoints included the QLQ-C30 global health score (GHS) and EuroQol visual analog scale (EQ-VAS) scores. Mean changes were compared using repeated measures mixed-effects models and are presented covariate adjusted.

Results

225 PEMBRO and 187 IPI + NIVO patients were enrolled. From baseline through week 24, PEMBRO was associated with 3.2 mean GHS score increase (95% CI 0.5, 5.9; p = .02), while no change was observed with IPI + NIVO; 0.2 (95% CI − 2.6, 3.0; p = 0.87). Among objective treatment-responders, GHS scores associated with PEMBRO increased 6.0 (95% CI 3.1, 8.8; p < .0001); IPI + NIVO patients increased 3.8 (95% CI 0.8, 6.9; p = .01). In treatment non-responders, IPI + NIVO was associated with GHS/QoL deterioration of − 3.7 (95% CI − 6.8, − 0.6; p = .02), PEMBRO non-responders demonstrated no change; 0.7 (95% CI − 2.3, 3.7; p = 0.6). Between treatments, PEMBRO patients increased 2.6 greater in EQ-VAS (95% CI 0.6, 4.5; p = .01) vs IPI + NIVO at 24 weeks.

Conclusions

PEMBRO was associated with better 24-week QoL compared to IPI + NIVO in actual clinical practice settings. Real-world data has known limitations, but with further confirmation these results may have implications for treatment selection.

Electronic supplementary material

The online version of this article (10.1007/s11136-020-02520-7) contains supplementary material, which is available to authorized users.

Hospitalization and emergency department utilization in patients with advanced melanoma receiving pembrolizumab versus ipilimumab plus nivolumab in US academic centers

Background: Both pembrolizumab (PEMBRO) and ipilimumab + nivolumab (IPI + NIVO) are FDA-approved immunotherapy regimens for advanced melanoma (AM). Each regimen has different toxicity profiles potentially impacting healthcare resource utilization (HCRU). This study compared real-world hospitalization and emergency department (ED) utilization within 12 months of therapy initiation of each regimen.Methods: A retrospective cohort study was conducted in AM patients ≥18 years old initiating PEMBRO or IPI + NIVO between January 1, 2016-December 30, 2017. Patients were identified from 12 US-based academic and satellite centers. All-cause hospitalization ED visits were identified. These events were used to calculate rates per 1,000 patient months. Utilization between groups was compared using multivariate logistic regression.Results: In total, 400 patients were included (200 PEMBRO, 200 IPI + NIVO). PEMBRO vs IPI + NIVO patients had poorer Eastern Cooperative Group (ECOG) performance status, 29% 2-4, vs 12% (p < .001); more diabetes, 21% vs 13% (p = .045); were more often PD-L1 expression positive, 77% vs 63% (p = .011); and less likely BRAF mutant, 35% vs 50% (p = .003). The proportion with more than one hospitalization over 12 months was 17% PEMBRO vs 24% IPI + NIVO. Less than 2% had more than one admission and none had more than two. Unadjusted mean (SD) hospitalizations per 1,000 patient-months were 16 (37) and 20 (38), PEMBRO and IPI + NIVO, respectively. Adjusted odds ratio for hospitalization was 0.6 (95% CI = 0.3-0.9; p = .027) for PEMBRO vs IPI + NIVO. ED visits occurred in 18% vs 21%, PEMBRO and IPI + NIVO, respectively, 0.7 (p = .186).Conclusions: PEMBRO patients had a significantly lower probability of hospitalization through 12 months vs IPI + NIVO. The probability of ED visits did not differ.

Health-related quality of life (HRQoL) in patients with advanced melanoma receiving immunotherapies across real-world clinical practice settings

e21004

Background: Pembrolizumab (PEMBRO) and combination ipilimumab + nivolumab (IPI+NIVO) are FDA-approved immunotherapies for advanced melanoma (AM). HRQoL was better maintained with PEMBRO vs IPI in KEYNOTE-006. CheckMate-067 reported no clinically meaningful HRQoL differences with IPI+NIVO vs IPI. As randomized trial data are lacking, we compared HRQoL outcomes in AM between PEMBRO and IPI+NIVO in real-world clinical settings. Methods: A prospective, observational study was conducted with sponsor blinded to sites, and sites blinded to sponsor; nine oncologists from 9 US academic centers and affiliated satellite clinics enrolled AM patients (pts) age ≥18 years initiating first-line PEMBRO or IPI+NIVO between June 2017 – March 2018. The European Organization for the Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ C30) and EQ-5D-5L were administered at baseline and weeks 6, 12, 18, and 24 following therapy. Least squared (LS) mean changes in HRQoL scores from baseline were compared using mixed-effects models for repeated measures, adjusting for baseline covariates. Results: A total of 225 PEMBRO and 187 IPI+NIVO pts were enrolled, with > 95% questionnaire completion rates through week 24. At baseline, PEMBRO pts were more likely > age 65 (49% vs 37%, p = .011), stage IV disease (92% vs 85%; p = .002), and higher comorbidity index (1.0 vs 0.6; p < .001) compared with IPI+NIVO pts. Adjusted EORTC global health status/quality of life (GHS) LS mean changes from baseline showed greater improvement with PEMBRO vs. IPI+NIVO at 12, 18 and 24 weeks. At week 24, PEMBRO pts achieved a 3.3-point improvement (95% CI = 0.8, 5.7) and IPI+NIVO pts had no significant change (1.0, 95% CI = -1.6, 3.5), with a LS mean difference of 2.3 points (p = .037; 95% CI = 0.14, 4.51). At week 24, the EQ-5D visual analogue scale increased 1.0 (95% CI, -1.2, 3.2) for PEMBRO vs IPI+NIVO which decreased 0.9 (95% CI = -3.2, 1.3), with a statistically significant LS mean difference of 2.0 (95% CI = 0.4, 3.9; p = .045). Conclusions: Results from 2 measures suggest HRQoL was maintained vs. baseline in both PEMBRO and IPI+NIVO pts, with a significant between-group difference favoring PEMBRO in GHS over 24 weeks.

Health care resource utilization in patients with advanced melanoma receiving immunotherapies in the real world

9532

Background: Both pembrolizumab (PEMBRO) and combination ipilimumab + nivolumab (IPI+NIVO) are FDA-approved immunotherapies for advanced melanoma (AM). These two treatment regimens have different toxicity profiles which may impact health care resource utilization (HCRU). Our aim was to compare real-world risk of hospitalization and emergency department (ED) visits within 12 months of starting the two treatment regimens. Methods: A retrospective cohort study was conducted in patients ≥18 years old with AM initiating PEMBRO or IPI+NIVO between Jan 1, 2016 – Dec 30, 2017. Patients were identified from 12 US academic medical centers and affiliated satellite clinics. Data were abstracted through chart review. All-cause hospitalizations or ED visits and the rates per patient per month (PPPM) through 12 months of follow-up were calculated. Utilization was compared between PEMRBO and IPI+NIVO using multivariate logistic regression analysis. Results: 400 patients were included, 200 each PEMBRO and IPI+NIVO with mean (SD) follow-up time of 10 (3) and 10 (4) months, respectively. The PEMBRO cohort had poorer Eastern Cooperative Group (ECOG) performance status at treatment start, 71% ECOG 0 or 1 vs 88% (p < .001); more diabetes, 21% vs 13% (p = .045); a trend towards more heart disease, 18% vs 12% (p = .067); were more likely to be PD-L1 expression positive, 77% vs 63% (p = .011); and less likely to harbor a BRAF mutation, 35% vs 50% (p = .003). The proportion with at least one hospitalization through 12 months was 17% PEMBRO vs 24% IPI+NIVO. Less than 2% of patients had more than one admission and none had more than two, regardless of cohort. Unadjusted mean (SD) PPPM hospitalizations were .016 (.037) for PEMBRO and .020 (.038) for IPI+NIVO. The adjusted odds ratio for any hospitalization with PEMBRO was 0.55 (95% CI .31, .97; p = .039) vs. IPI+NIVO. ED visits occurred in 18% vs 21% in PEMBRO and IPI+NIVO respectively, with no difference in covariate-adjusted analysis (p = .147). Conclusions: Patients receiving PEMBRO had a significantly lower probability of hospitalization and similar probability of ER visits compared with IPI+NIVO in the real world through 12 months.

Factors associated with immunotherapy selection in patients with advanced melanoma

AIM

To explore factors associated with pembrolizumab (PEMBRO) versus ipilimumab + nivolumab (IPI+NIVO) selection in advanced melanoma.

MATERIALS & METHODS

Total of 12 academic and satellite clinics contributed to this study. Descriptive and logistic regression analyses were conducted to explore associations between clinical characteristics and treatment choice.  Results: Total of 400 patients were included: 200 PEMBRO and 200 IPI+NIVO. Patients were significantly more likely to receive PEMBRO versus IPI+NIVO if they had poorer Eastern Cooperative Oncology Group score, 2-4 versus 0-1 (odds ratio [OR]: 6.6; 95% CI: 3.0-14.7), if they were PD-L1 positive (OR: 4.5; 95% CI: 1.9-10.4) or had BRAF wild-type tumor (OR: 2.2; 95% CI: 1.4-3.6).

CONCLUSION

Patient factors are significantly associated with treatment selection in advanced melanoma. Outcomes comparisons should take this into consideration.

An unusual array of extensor musculature and tendons of the hand clinico-anatomical insight

Extensor tendon injury is a frequent finding in clinical practice. During a routine dissection class of undergraduate medical students examining the extensor aspect of the right hand, they found an interesting pattern of extensor tendons. The extensor digitorum (ED) exhibited three tendons for the middle and ring fingers. The intermediate tendon of the ED was found to pass to the junctura connecting the tendons of the ring and middle fingers. Additionally the Extensor carpi ulnaris displayed two tendinus slips. The lateral slip was inserted on the base of fifth metacarpal as usual, whereas the medial slip divided into two strands- proximal and distal. Apart from the above findings in the current case specimen, there was an accessory muscle belly for the index finger and the extensor digiti minimi bifurcated into two tendinus slips which gained attachment to the dorsal digital expansion of the little finger. These accessory muscle bellies and tendons could possibly be utilized for tendon reconstructions such as repairs, tenoplasties or tendon transfers.

Unusual architecture of extensor digitorum muscle of hand in conjunction with accessory belly of extensor carpi radialis brevis: a clinico-anatomical insight

The present article highlights an unusual combination of variations of the extensor digitorum and extensor carpi radialis brevis muscles in the dorsum of forearm and hand. The extensor carpi radialis brevis exhibited an accessory musculotendinous belly which inserted into the dorsal digital expansion of index finger. The extensor digitorum showed trifurcation into three distinct parts. Resultant multiple extensor tendon insertion pattern is reported upon highlighting the embryological basis and clinical importance. Knowledge of such anatomical variations adds upon the already existing information in literature and is also of profound interest to the clinician. Anatomical awareness of accessory multiple extensor tendons in the dorsum of hand is essential for successful management of extensor tendon injuries and graft transfer operations.

Microinjection of glycine into the ventral tegmental area selectively decreases ethanol consumption

The mechanisms of ethanol addiction are not completely understood. The mesolimbic dopaminergic system is involved in many drug-related behaviors, including ethanol self-administration. The dopaminergic neurons in this system originate in the ventral tegmental area (VTA) and are under the control of GABAergic transmission. Our previous in vitro electrophysiological data indicate that glycine receptors (GlyRs) exist on the GABAergic terminals, which make synapses on VTA dopaminergic neurons, and activation of these GlyRs reduces GABAergic transmission and increases the activity of VTA dopaminergic neurons. In the current study, we tested the hypothesis that the activation of the presynaptic GlyRs in the VTA might interfere with ethanol self-administration. Glycine and strychnine, the selective antagonist of GlyRs, were injected, either alone or in combination, into the VTA of rats. Ethanol self-administration by rats was evaluated by using three different drinking models: intermittent access, continuous access, and operant self-administration. We found that the infusion of glycine into the VTA selectively reduced the intake of ethanol but not sucrose or water in rats chronically exposed to ethanol under the intermittent-access and continuous-access procedures and decreased lever-press responding for ethanol under an operant self-administration procedure. The effects of glycine probably were mediated by strychnine-sensitive GlyRs, because the coinjection of glycine and strychnine reduced neither ethanol intake in the home cages nor lever-press responding for ethanol in the operant chambers. Thus, GlyRs in the VTA may play a critical role in ethanol self-administration in animals chronically exposed to ethanol. Therefore, drugs targeting GlyRs may be beneficial for alcoholics.

Blockade of GABA(A) receptors in the paraventricular nucleus of the hypothalamus attenuates voluntary ethanol intake and activates the hypothalamic-pituitary-adrenocortical axis

The paraventricular nucleus (PVN) in the hypothalamus is the main integration site that controls the hypothalamic-pituitary-adrenal (HPA) neuroendocrine stress system. Disruption of this system has been linked with alcoholism, but the specific role of the PVN has not been fully explored. Of particular interest is the ability of γ-aminobutyric acid type A receptors (GABA(A)Rs) in the PVN, to regulate ethanol self-administration behavior, as these receptors appear to play an essential role in mediating the effects of ethanol in the central nervous system and in the regulation of PVN activity. We observed that Long-Evans rats, in the intermittent access to 20% ethanol paradigm, consumed high amounts of ethanol and subsequently developed ethanol dependence. Microinjection of the GABA(A)R antagonist picrotoxin into the PVN, but not to the lateral ventricle of the brain, significantly reduced the intake of ethanol, but not the intake of sucrose. Picrotoxin-induced reduction was mimicked by another GABA(A)R antagonist bicuculline but was attenuated by the GABA(A)R agonist muscimol. Moreover, increased ethanol consumption was associated with lowered blood corticosterone levels, indicating a blunted HPA signaling, which was reversed by intra-PVN injection of picrotoxin, as indicated by the increased Fos immunostaining-positive cells in the PVN and the increased blood corticosterone levels. Taken together, our data provide evidence that in ethanol-dependent rats, the function of GABA(A)Rs in the PVN is upregulated, leading to a dampened HPA system. Moreover, it demonstrates that the GABA(A)R antagonists normalize HPA axis signaling and reduce excessive ethanol drinking. Therefore, drugs targeting GABA(A)Rs may be beneficial for alcoholics.

Pharmacology of ivermectin

Ivermectin is a semi-synthetic macrocyclic lactone (Fig. I) active in single low doses against many parasites - particularly nematodes and arthropods. It has been registered for animal health use since early 1985, and was earlier this year approved for human use by the French Directorate o f Pharmacy and Drugs. Of particular interest is ivermectin's potential as a micro filaricide for treatment o f onchocerciasis. Clinical trials leave little doubt about the potential o f ivermectin as a therapeutic tool for symptomatic relief from the effects o f infection with Onchocerca volvulus, and the drug is also recognized to have potential in reducing transmission o f the parasite. The manufacturers (Merck, Sharp and Dohme) recently arranged to provide the drug free o f charge to the WHO for mass trials against onchocerciasis in 12 African and Central American countries. In this article we focus on the pharmacological properties o f ivermectin, with a brief consideration of its absorption, fate, excretion and side-effects, and a discussion o f its micro filaricidal action.

Now you see it, now you don't: statistical and methodological considerations in fMRI

We illustrate the effects of statistical threshold, spatial clustering, voxel size, and two approaches to multiple comparison correction on fMRI results. We first analyzed fMRI images obtained from a single subject during a noun-verb matching task. Data were analyzed with Statistical Parametric Mapping (SPM) using two different voxel sizes, and results were displayed at three different levels of statistical significance. At each statistical threshold, results were first uncorrected for multiple comparisons and spatial extent and then presented using a spatial extent cluster of 20 voxels. We then statistically controlled the Type I error rate associated with multiple comparisons by using the false discovery rate and by the random field adjustment for false-positive rate used by SPM. We also examined group results from language and graphesthesia paradigms at three levels of statistical significance. In all circumstances, apparent random activations decreased as more conservative statistical approaches were employed, but activation in areas considered to be functionally significant was also reduced. These issues are important in the choice of analytic approach and interpretation of fMRI results, with clear implications for the surgical management of individual patients when fMRI results are used to delineate specific areas of eloquent cortex.

Signal amplification by rolling circle amplification on DNA microarrays

While microarrays hold considerable promise in large-scale biology on account of their massively parallel analytical nature, there is a need for compatible signal amplification procedures to increase sensitivity without loss of multiplexing. Rolling circle amplification (RCA) is a molecular amplification method with the unique property of product localization. This report describes the application of RCA signal amplification for multiplexed, direct detection and quantitation of nucleic acid targets on planar glass and gel-coated microarrays. As few as 150 molecules bound to the surface of microarrays can be detected using RCA. Because of the linear kinetics of RCA, nucleic acid target molecules may be measured with a dynamic range of four orders of magnitude. Consequently, RCA is a promising technology for the direct measurement of nucleic acids on microarrays without the need for a potentially biasing preamplification step.

Target selectivity of bicoid is dependent on nonconsensus site recognition and protein-protein interaction

We describe experiments to compare the activities of two Drosophila homeodomain proteins, Bicoid (Bcd) and an altered-specificity mutant of Fushi tarazu, Ftz(Q50K). Although the homeodomains of these proteins share a virtually indistinguishable ability to recognize a consensus Bcd site, only Bcd can activate transcription from natural enhancer elements when assayed in both yeast and Drosophila Schneider S2 cells. Our analysis of chimeric proteins suggests that both the homeodomain of Bcd and sequences outside the homeodomain contribute to its ability to recognize natural enhancer elements. We further show that, unlike the Bcd homeodomain, the Ftz(Q50K) homeodomain fails to recognize nonconsensus sites found in natural enhancer elements. The defect of a chimeric protein containing the homeodomain of Ftz(Q50K) in place of that of Bcd can be preferentially restored by converting the nonconsensus sites in natural enhancer elements to consensus sites. Our experiments suggest that the biological specificity of Bcd is determined by combinatorial contributions of two important mechanisms: the nonconsensus site recognition function conferred by the homeodomain and the cooperativity function conferred primarily by sequences outside the homeodomain. A systematic comparison of different assay methods and enhancer elements further suggests a fluid nature of the requirements for these two Bcd functions in target selection.

Reprogrammable recognition codes in bicoid homeodomain-DNA interaction

We describe experiments to determine how the homeodomain of the Drosophila morphogenetic protein Bicoid recognizes different types of DNA sequences found in natural enhancers. Our chemical footprint analyses reveal that the Bicoid homeodomain makes both shared and distinct contacts with a consensus site A1 (TAATCC) and a nonconsensus site X1 (TAAGCT). In particular, the guanine of X1 at position 4 (TAAGCT) is protected by Bicoid homeodomain. We provide further evidence suggesting that the unique arginine at position 54 (Arg 54) of the Bicoid homeodomain enables the protein to recognize X1 by specifically interacting with this position 4 guanine. We also describe experiments to analyze the contribution of artificially introduced Arg 54 to DNA recognition by other Bicoid-related homeodomains, including that from the human disease protein Pitx2. Our experiments demonstrate that the role of Arg 54 varies depending on the exact homeodomain framework and DNA sequences. Together, our results suggest that Bicoid and its related homeodomains utilize distinct recognition codes to interact with different DNA sequences, underscoring the need to study DNA recognition by Bicoid-class homeodomains in an individualized manner.

CD3delta couples T-cell receptor signalling to ERK activation and thymocyte positive selection

Thymocytes from mice lacking the CD3delta chain of the T-cell receptor (TCR), unlike those of other CD3-deficient mice, progress from a CD4- CD8- double-negative to a CD4+ CD8+ double-positive stage. However, CD3delta-/- double-positive cells fail to undergo positive selection, by which double-positive cells differentiate into more mature thymocytes. Positive selection is also impaired in mice expressing inactive components of the Ras/mitogen activated protein (MAP) kinase signalling pathway. Here we show that CD3delta-/- thymocytes are defective in the induction of extracellular signal-regulated protein kinase (ERK) MAP kinases upon TCR engagement, whereas activation of other MAP kinases is unaffected. The requirement for CD3delta maps to its extracellular or transmembrane domains, or both, as expression of a tail-less CD3delta rescues both ERK activation and positive selection in CD3delta-/- mice. Furthermore, the defect correlates with severely impaired tyrosine phosphorylation of the linker protein LAT, and of the CD3zeta chain that is localized to membrane lipid rafts upon TCR engagement. Our data indicate that the blockade of positive selection of CD3delta-/- thymocytes may derive from defective tyrosine phosphorylation of CD3zeta in lipid rafts, resulting in impaired activation of the LAT/Ras/ERK pathway.

Regulation of lineage commitment distinct from positive selection

Developing alphabeta T cells diverge into the CD4 and CD8 lineages as they mature in the thymus. It is unclear whether lineage commitment is mechanistically distinct from the process that selects for the survival of T cells with useful T cell receptor (TCR) specificities (positive selection). In HD mice, which lack mature CD4+ T cells, major histocompatibility complex (MHC) class II-restricted T cells are redirected to the CD8 lineage independent of MHC class I expression. However, neither TCR-mediated signaling nor positive selection is impaired. Thus, the HD mutation provides genetic evidence that lineage commitment may be mechanistically distinct from positive selection.

Evolutionarily conserved promoter region containing CArG*-like elements is crucial for smooth muscle myosin heavy chain gene expression

In recent years, significant progress has been made toward understanding skeletal muscle development. However, the mechanisms that regulate smooth muscle development and differentiation are presently unknown. To better understand smooth muscle-specific gene expression, we have focused our studies on the smooth muscle myosin heavy chain (SMHC) gene, a highly specific marker of differentiated smooth muscle cells. The goal of the present study was to isolate and characterize the mouse SMHC gene promoter, since the mouse promoter would be particularly suited for in vivo promoter analyses in transgenic mice and would serve as a tool for targeting genes of interest into smooth muscle cells. We report here the isolation and characterization of the mouse SMHC promoter and its 5' flanking region. DNA sequence analysis of a 2.6-kb portion of the promoter identified several potential binding sites for known transcription factors. Transient transfection analysis of promoter deletion constructs in primary cultures of smooth muscle cells showed that the region between -1208 and -1050 bp is critical for maximal SMHC promoter activity. A comparison of SMHC promoter sequences from mouse, rat, and rabbit revealed the presence of a highly conserved region located between -967 and -1208 bp. This region includes three CArG/CArG*-like elements, two SP-1 binding sites, a NF-1-like element, an Nkx2-5 binding site, and an Elk-1 binding site. Gel mobility shift assay and DNase I footprinting analyses show that all three CArG/CArG*-like elements can form DNA-protein complexes with nuclear extract from vascular smooth muscle cells. Protein binding to the CArG* elements can be competed out by either serum response element or by an authentic CArG element from the cardiac alpha-actin gene. Using a serum response factor (SRF) antibody, we demonstrate that SRF is part of the protein complex. In addition, we show that cotransfection with the SRF dominant-negative mutant expression vector abolishes SMHC promoter activity, suggesting that SRF protein plays a critical role in SMHC gene regulation.

A novel E box/AT-rich element is required for muscle-specific expression of the sarcoplasmic reticulum Ca2+-ATPase (SERCA2) gene

The cardiac/slow twitch sarcoplasmic reticulum (SR) Ca2+-ATPase gene (SERCA2 ) encodes a calcium transport pump whose expression is regulated in a tissue- and development-specific manner. Previously we have identified two distinct positive regulatory regions (bp -284 to -72 and -1815 to -1105) as important for SERCA2 promoter activity. Here we demonstrate that the SERCA2 distal promoter region functions like an enhancer by activating a heterologous promoter (TK) in a muscle cell-specific manner. Through deletion analysis a core enhancer region was delimited to the -1467 to -1105 bp fragment. We identified the E box/AT-rich element located at -1115 bp as critical for maximal enhancer activity. Gel mobility shift studies revealed that this E box/AT-rich element specifically binds a protein which is induced during Sol8 myogenesis. This region includes two other cis -acting elements, CArG and MCAT, which also bind specific nuclear protein complexes from Sol8 myotubes. Mutagenesis of each of these sites resulted in decreased SERCA/TK-CAT promoter activity. Based on these data, we propose that the E box/AT-rich element may contribute along with CArG and MCAT elements to the overall activation and regulation of the SERCA2 gene promoter.

MEF2B is a component of a smooth muscle-specific complex that binds an A/T-rich element important for smooth muscle myosin heavy chain gene expression

To understand smooth muscle-specific gene expression, we have focused our studies on the smooth muscle myosin heavy chain (SMHC) gene, a smooth muscle-specific marker. In this study, we demonstrate that the SMHC promoter region (-1594 to -1462 base pairs) containing the A/T-rich element can activate the heterologous thymidine kinase promoter in smooth muscle cells, but not in fibroblasts. Mutations of this A/T-rich element decreased SMHC promoter activity significantly. Both gel mobility shift assays and DNase I footprinting revealed that this region binds to specific protein complexes from smooth muscle nuclear extracts, whereas nuclear extracts from skeletal muscle and fibroblasts produced a different binding pattern. We also demonstrate that the protein complex obtained from smooth muscle nuclear extract reacts with MEF2B-specific antibody, but not with antibodies specific to MEF2A, MEF2C, or MEF2D, suggesting that only MEF2B protein binds to the A/T-rich element. Furthermore, MEF2B overexpression in smooth muscle cells up-regulated the SMHC promoter, suggesting that MEF2B is important for SMHC gene regulation. This is the first report demonstrating a role for MEF2 factors in smooth muscle-specific gene expression.

Transmitter-induced calcium responses differ in astrocytes acutely isolated from rat brain and in culture

Glial fibrillary acid protein (GFAP)-positive astrocytes isolated from the cerebral cortices of 3-10-day-old rats frequently showed increased intracellular Ca2+ concentration responses to L-glutamate and glutamate analogues. However, few of the acutely isolated cells responded to ATP, and no such cells responded to serotonin [5-hydroxytryptamine (5-HT)]. The same cell that failed to respond to ATP or 5-HT often responded to glutamate. Culturing acutely isolated cells in media containing horse serum decreased Ca2+ responses to glutamate but increased the responses to ATP and induced responses to 5-HT. In primary cultures prepared from the cerebral cortices of 1-day-old rats and cultured in horse serum, fewer of the cells responded to glutamate, but almost all cells responded to ATP and 5-HT. The lack of or limited response to, 5-HT or ATP in the acutely isolated cells seems unlikely to be due to selective damage to the respective receptors because acutely isolated GFAP-negative cells showed responses to ATP, several different proteases and mechanical dissociation yielded cells that also responded to glutamate but not to ATP, and exposure of primary cultures to papain did not abolish Ca2+ responses to several transmitters. The responses of the acutely isolated cells to glutamate but limited or lack of responses to ATP and 5-HT also correspond to what has been seen so far for astrocytes in situ. Thus, the present studies provide direct evidence that some of the receptors seen in primary astrocyte cultures may reflect a response to culture conditions and that, in the context of the relevant information so far available, acutely isolated astrocytes seem to reflect better the in vivo state.

Effects of thyroid hormone on left ventricular performance and regulation of contractile and Ca(2+)-cycling proteins in the baboon. Implications for the force-frequency and relaxation-frequency relationships

The transcriptional, posttranscriptional, and related functional effects of thyroid hormone on primate myocardium are poorly understood. Therefore, we studied the effects of thyroid hormone on sarcoplasmic reticulum (SR) Ca(2+)-cycling proteins and myosin heavy chain (MHC) composition at the steady state mRNA and protein level and associated alterations of left ventricular (LV) performance in 8 chronically instrumented baboons. The force-frequency and relaxation-frequency relations were assessed as the response of LV isovolumic contraction (dP/dtmax) and relaxation (Tau), respectively, to incremental atrial pacing. Both the heart rate at which dP/dtmax was maximal and Tau was minimal (critical heart rates) in response to pacing were increased significantly after thyroid hormone. Postmortem LV tissue from 5 thyroid-treated and 4 additional control baboons was assayed for steady state mRNA levels with cDNA probes to MHC isoforms and SR Ca(2+)-cycling proteins. Steady state SR Ca(2+)-ATPase and phospholamban mRNA increased in the hyperthyroid state, and alpha-MHC mRNA appeared de novo, whereas beta-MHC mRNA decreased. Western analysis (4 thyroid-treated and 4 control baboons) showed directionally similar changes in MHC isoforms and a slight increase in SR Ca(2+)-ATPase. In contrast, there was a statistically nonsignificant decrease in phospholamban protein, which resulted in a significant 40% decrease in the ratio of phospholamban to SR Ca(2+)-ATPase. Thus, thyroid hormone increases the transcription of Ca(2+)-cycling proteins and shifts MHC isoform expression in the primate LV. Our data suggest that both transcriptional and posttranslational mechanisms determine the levels of these proteins in the hyperthyroid primate heart and mediate, in part, the observed enhanced basal and frequency-dependent LV performance.

Multiple Sp1 binding sites in the cardiac/slow twitch muscle sarcoplasmic reticulum Ca2+-ATPase gene promoter are required for expression in Sol8 muscle cells

The rabbit cardiac/slow twitch muscle sarcoplasmic reticulum Ca2+-ATPase (SERCA2) gene encodes a Ca2+ transport pump whose expression is regulated during skeletal and cardiac muscle development and in response to various pathophysiological and hormonal states. Employing transient transfection analyses in Sol8 muscle cells, we have identified two positive regulatory regions, one distal (-1810 base pair (bp) to -1110 bp) and one proximal (-284 bp to -72 bp), within the SERCA2 promoter. The proximal promoter region from -284 bp to -80 bp was shown to confer muscle-specific expression to a heterologous promoter in Sol8 cells. This region is highly GC-rich containing the consensus sequence for four Sp1 elements (GGGCGG) and three Sp1-like elements (GGGAGG). DNase I footprint analysis with Sol8 nuclear extracts and purified Sp1 protein showed the protection of the seven Sp1 binding sites. In addition, site-directed mutagenesis of the Sp1 consensus sites demonstrated that Sp1 sites are essential for the muscle-specific expression of the SERCA2 promoter. Furthermore, we demonstrate that cotransfection of an Sp1 expression vector together with SERCA2-CAT constructs can up-regulate SERCA2 promoter activity. These results imply that the Sp1 transcription factor plays an important role in the transcriptional regulation of SERCA2 within muscle cells.

Reduced urinary kallikrein excretion in human renovascular hypertension caused by nonspecific aortoarteritis and other disorders

In this study urinary kallikrein excretion was measured using the kininogenase bioassay technique in 12 normal volunteers and 23 patients with angiographically-proven renovascular hypertension (RVHT). In 13 of these (group I), RVHT was due to nonspecific aortoarteritis (NSAA) and in 10 (group II) due to other causes. Urinary kallikrein (UKa) excretion was significantly lower in patients, with values still lower in NSAA. PRA was high in both the groups in comparison with controls; however, the levels were significantly lower in group I compared with group II. Finding of both UKa and PRA lower in group I is suggestive of long standing hypertension becoming volume dependent with nephrosclerotic changes in the kidney. These results point to decreased renal kallikrein-kinin system activity as a feature of NSAA that probably contributes chiefly to the maintenance of the hypertensive state. Normalisation of BP with restoration of UKa and PRA towards normal in three patients of group I and five in group II further support the role of UKa not only when over activity of renin-angiotensin system is responsible for RVHT as in group II but also in group I when the hypertension becomes volume dependent.

Na(+)-dependent, fluoxetine-sensitive serotonin uptake by astrocytes tissue-printed from rat cerebral cortex

Previous studies have established that rat primary astrocyte cultures prepared from several brain regions of 1-4-d-old rats exhibit high-affinity, Na(+)-dependent and fluoxetine-sensitive serotonin (5-HT) uptake with a Km for 5-HT of 0.4 microM and a Ki for fluoxetine of 23 nM, which correspond to the characteristics for this transport for other brain preparations. However, it is not known whether astrocytes in situ show such uptake. We addressed this question by performing 3H-5-HT uptake experiments on cortical astrocytes, within 4 hr of isolating them from 6- and 21-d-old rats by the tissue-print technique. Quantitative autoradiography was combined with GFAP and neurofilament (NF) immunocytochemistry to distinguish astrocytic from neuronal 3H-5-HT uptake. In composition, the tissue-printed (TP) cells and processes were 60-70% GFAP (+) and 10-15% NF(+). 3H-5-HT uptake (0.3 microM 5-HT, 3.4 microCi/ml) in both tissue-printed GFAP(+) astrocytes and NF(+) structures was sensitive to 1 microM fluoxetine and was also Na+ dependent. More than 90% of TP astrocytes from 6- and 21-d-old rats and 100% of NF(+) structures from 21-d-old rats showed positive 3H-5-HT uptake (defined as > or = 31 grains/10(3) microns2). The highest level of uptake (> or = 191 grains/10(3) microns2) was never observed in TP astrocytes but was exhibited by about half of the NF(+) structures. In other experiments were found that 3H-5-HT uptake by 6-d-old TP astrocytes was comparable to uptake by postnatal age-matched primary cultured astrocytes that were grown in fetal bovine serum (FBS). However, primary cultured astrocytes grown in horse serum showed lower uptake than that observed with FBS, a finding similar to previous results in cultures where 3H-5-HT uptake was measured per milligram of cell protein. These results imply that high-affinity, Na(+)-dependent and fluoxetine-sensitive 5-HT uptake occurs in rat cortical astrocytes in situ.

Astrocytes as mediators of methylmercury neurotoxicity: effects on D-aspartate and serotonin uptake

In this study we address the effects of methylmercuric chloride (MeHgCl), a metal that is preferentially sequestered in astrocytes, on 5-HT and glutamate/aspartate uptake by rat primary astrocyte cultures. Quantitative autoradiography (ARG) combined with glial acidic fibrillary protein (GFAP) immunocytochemistry, as well as intact-cell (bulk) measurements of radiolabel uptake of these neurotransmitters were performed in 7- and 21-day-old primary astrocyte cultures. MeHg (10 microM for 30 min) treatment of astrocytes (21 days in culture) significantly inhibited the Na(+)-dependent and fluoxetine-sensitive [3H]5-HT uptake. D-aspartate uptake in 7- and 21-day-old cultures was even more sensitive to MeHg, leading to > 99% inhibition of D-aspartate uptake by astrocytes (30 min; 10 microM MeHg). These results imply that the Na(+)-dependent and fluoxetine-sensitive 5-HT uptake, as well as the Na(+)-dependent L-glutamate/D-aspartate uptake systems in primary astrocyte cultures are sensitive to low concentrations of MeHg. Since astrocytic removal of glutamate (and aspartate) and 5-HT from the extracellular space in situ is crucial to the maintenance of chemical homeostasis, MeHg-induced uptake inhibition of 5-HT and aspartate could have cytotoxic effects on neighboring neurons.

Lead increases inositol 1,4,5-trisphosphate levels but does not interfere with calcium transients in primary rat astrocytes

Alteration of receptor-mediated signal transduction pathways by inorganic lead (Pb) has been postulated to contribute to the neurotoxicity of this environmental toxicant, some of these effects involving astrocytes. As Pb is known to mimic Ca2+ in various biological systems or alter Ca(2+)-mediated cellular processes, we analyzed the effect of Pb exposure on alpha 1 receptor activated astrocytic phosphoinositide metabolism and Ca2+ responses in primary astrocyte cultures prepared from cerebral cortex of 1-day-old rats. Exposure to norepinephrine (NE; 10-100 microM) resulted in a significant increase in astrocytic inositol 1,4,5-trisphosphate levels, concomitant with an increase in intracellular Ca2+ levels. Fifteen minute exposure to Pb (10 microM lead acetate) significantly increased inositol 1,4,5-trisphosphate generation compared with controls, both in the presence and absence of NE. However, the inositol 1,4,5-trisphosphate-mediated Ca2+ transients following NE stimulation was unaltered in the presence of Pb (1-100 microM). NE-evoked intracellular Ca2+ responses, both in the presence and absence of extracellular Ca2+ did not differ between control and Pb-treated astrocytes. Additional studies failed to demonstrate the occurrence of Pb influx into astrocytes within the first 12 min of exposure such that Ca2+ responses would be directly affected. It therefore appears unlikely that astrotoxic effects of Pb are mediated via direct changes in intracellular Ca2+ transients.

Detection of 5-hydroxytryptamine2 receptors by radioligand binding, northern blot analysis, and Ca2+ responses in rat primary astrocyte cultures

Radioligand binding, Northern blot analysis, and changes in [Ca2+]i were used to study serotonin [5-hydroxytryptamine (5HT)] receptor subtypes in primary cultures of astrocytes from neonatal rat cerebral cortex. Radioligand binding studies revealed the presence of 5HT2, but not the 5HT1 or 5HT3 receptor subtypes. Radioligand binding was also used to show the presence of serotonin uptake sites, which had previously been shown to be present by [3H]-5HT uptake, and also alpha 1-adrenergic receptors as has previously been reported by binding studies. Northern blot analysis of cortical astrocyte mRNA demonstrated the presence of transcripts for 5HT2 receptors, but failed to identify mRNA for 5HT1a or 5HT1c receptors. Thus, results from Northern blot analysis correlated with the radioligand binding data which showed only 5HT2 receptors. Equilibrium saturation studies, using 125[I]-LSD to label 5HT2 receptors, yielded a KD of 9 nM and a Bmax of 177 fmol/mg protein. Radioligand binding studies or primary astrocyte cultures prepared from other brain regions also showed the presence of alpha 1-adrenergic, 5HT2 receptor, and 5HT-uptake sites, but no detectable 5HT1a receptors, which were the only 5HT1 receptors studied. Studies demonstrating 5HT-induced, spiperone- and ketanserin-sensitive increases in free [Ca2+]i as measured by FURA-2, showed that the 5HT2 receptors were functional in these cells. These data provide clear evidence for the existence of both 5HT2 receptors and 5HT-uptake sites in the same primary astrocyte cultures from neonatal rat cerebral cortex, with no detectable evidence of 5HT1a or 5HT1c subtypes.

Peripheral and renal vein renin activity in patients with renovascular hypertension due to nonspecific aortoarteritis

The diagnostic utility of peripheral and renal vein renin estimations in relation to angiographic findings was evaluated in 13 patients with renovascular hypertension and non-specific aortoarteritis (NSAA, Gr I), in comparison with 10 patients with renal artery stenosis due to other causes (Gr II). Plasma renin activity (PRA) was measured by radioimmunoassay. Blood samples were collected after angiography from the femoral vein and renal vein on the affected side followed by sampling from the less affected or unaffected side. Renal vein renin ratio (RVRR) was calculated from renal vein renin values. The effect of captopril (25 mg oral) on blood pressure, PRA, and RVRR was examined in 8 patients from each group. Normotensive volunteers (8) with moderately low salt intake were also included in the study for comparison of twenty-four-hour urinary sodium output, peripheral PRA, and response to captopril. The mean peripheral PRA was high in both groups as compared with normotensive controls; however, the values were lower in patients with NSAA. The rise in PRA in response to captopril was insignificant in Gr I (p greater than 0.05) and RVRR greater than 1.5 was observed in 5 of 13 patients in contrast to 9 of 10 in Gr II (p less than 0.05). A paradoxical ratio, ie, (high renal vein renin levels on the less stenotic side) was noticed in 3 patients of Gr I, whereas none of the patients of GR II showed such a ratio. An improvement in RVRR after captopril was observed in 50% of patients of Gr I as compared with a marked response in all patients of Gr II.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral type 2 astroglia are heterogeneous with respect to their ability to respond to neuroligands linked to calcium mobilization

Very little information is available concerning the pharmacology of type 2 astroglia. During the past decade it has become apparent that two distinct lineages of astroglial cells can be defined in vitro. These two lineages are commonly referred to as type 1 and type 2 and are distinguished from each other on the basis of their morphological features and antigenic phenotypes. In contrast to type 1 astroglia, very little is known about the pharmacology of type 2 astroglia. The lack of information concerning the responsiveness of these cells stems primarily from difficulties encountered in isolating large numbers of type 2 astroglia free of other cell types. In the present study video- and photometer-based imaging systems were used to monitor the influence of a series of neuroligands on the intracellular calcium levels of individual cerebral type 2 astroglia in order to assess their expression of calcium-mobilizing receptors. The responses of 85 immunocytochemically identified cerebral type 2 astroglia to bradykinin (BK), norepinephrine (NE), histamine (HIST), carbachol (CARB), 2-methyl-thio ATP (2MT-ATP), glutamate (GLUT), and serotonin (5-HT) were analyzed. Approximately 50% of cerebral type 2 astroglia responded to BK, NE, HIST, CARB, and 2MT-ATP whereas only 16% and 9% of the cells responded to GLUT and 5-HT, respectively. The number of neuroligands that increased calcium in individual cells ranged from 0 to 6. These responses are quite similar to those previously demonstrated in cultured cerebral type 1 astroglia. No pattern of receptor co-expression was observed for the different neuroligands tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Disruption of FR-40 by 5-HT agonists. I. Effects of chronic imipramine or trazodone

Doses of LSD, quipazine, 8-OHDPAT and TFMPP were established that prominently disrupted FR-40 operant response pattern in two groups of rats. Subsequently, one group received daily intraperitoneal (IP) injections of imipramine, 2.5 mg/kg, for 4 weeks, then 10 mg/kg for 2 additional weeks. The second group received 5 mg/kg/day, IP, of trazodone for the first 4 weeks, then 20 mg/kg/day for the next two weeks. For these periods and the 3 weeks after discontinuing the chronic drug treatments (washout), test doses of the 4 agonists were evaluated twice weekly in random order for their effects to decrease FR-40 reinforcements and increase pauses. No consistent, systematic changes in sensitivity to the agonist effects on FR-40 behavior were observed during chronic drug treatments, although significant effects were at times observed. However, during the washout period in the imipramine group, both LSD and 8-OHDPAT effects on reinforcements were reversed to baseline levels. The effect of 5-OHDPAT on pauses during washout in this group was also attenuated. During washout in the trazodone group, the 8-OHDPAT-induced pausing and loss of reinforcements was reduced so as to be not significantly different from baseline values. Previous studies have demonstrated antagonism of LSD- and quipazine-induced disruption of FR-40 by pretreating with the 5-HT2-selective antagonist pirenperone (28). Since chronic antidepressants down-regulate brain 5-HT2 binding sites, the effects of LSD and quipazine were expected to be attenuated, which was not the case.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis and characteristics of allylic 4-pregnene-3,20-diols found in gonadal and breast tissues

Recently several allylic steroids have been found in gonadal and breast tissues. In order to establish their presence and identity in tissues and determine the possible biological properties, a method for the synthesis of 4-pregnene-3 alpha,20 alpha-diol, 4-pregnene-3 alpha, 20 beta-diol, 4-pregnene-3 beta,20 alpha-diol, and 4-pregnene-3 beta,20 beta-diol was developed using 4-pregnene-3,20-dione (progesterone) as substrate and freshly-prepared aluminum isopropoxide in isopropyl alcohol as reducing agent. The yields were about 19%, 30%, 13%, and 38% for the 3 alpha,20 alpha-, 3 alpha,20 beta-, 3 beta,20 alpha-, and 3 beta,20 beta-diols, respectively. The structures and stereochemistry of these diols were established using proton and carbon NMR spectroscopy and infrared and mass spectrometry.

Synthesis of the allylic gonadal steroids, 3 alpha-hydroxy-4-pregnen-20-one and 3 alpha-hydroxy-4-androsten-17-one, and of 3 alpha-hydroxy-5 alpha-pregnan-20-one

A method for the convenient synthesis of the recently isolated allylic gonadal steroids, 3 alpha-hydroxy-4-pregnen-20-one (3 alpha-dihydroprogesterone; 3 alpha-DHP) and 3 alpha-hydroxy-4-androsten-17-one (3 alpha-HA), was developed using 4-pregnene-3,20-dione (progesterone) and 4-androstene-3,17-dione as substrates and potassium trisiamylborohydride (KS-Selectride) as reducing agent. Similar reactions were also used for the reduction of 5 alpha-pregnane-3,20-dione to 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-HP). The yields were about 15%, 50%, and greater than 90% for 3 alpha-DHP, 3 alpha-HA and 3 alpha-HP, respectively. Structures of the products, including the 3 beta-isomers and the 17 alpha-epimer, formed in these reactions were determined by NMR and mass spectroscopic methods.

Serologic and biochemical studies of a previously unclassified blood type B variant

The designation B4 is proposed for a weak variant of type B blood found in a Salvadorian woman and her two daughters. The red cells were weakly agglutinated by anti-B and anti-A,B; the serum contained anti-B; and the saliva contained H but not B substance. Biochemical studies of the serum showed that the enzyme specified by the variant B gene had low activity and low affinity for both sugar donor and acceptor.