A Frameshift Variant of GluN2A Identified in an Epilepsy Patient Results in NMDA Receptor Mistargeting

N-methyl-D-aspartate receptors (NMDARs) are crucial for neuronal development and synaptic plasticity. Dysfunction of NMDARs is associated with multiple neurodevelopmental disorders, including epilepsy, autism spectrum disorder, and intellectual disability. Understanding the impact of genetic variants of NMDAR subunits can shed light on the mechanisms of disease. Here, we characterized the functional implications of a de novo mutation of the GluN2A subunit (P1199Rfs*32) resulting in the truncation of the C-terminal domain. The variant was identified in a male patient with epileptic encephalopathy, multiple seizure types, severe aphasia, and neurobehavioral changes. Given the known role of the CTD in NMDAR trafficking, we examined changes in receptor localization and abundance at the postsynaptic membrane using a combination of molecular assays in heterologous cells and rat primary neuronal cultures. We observed that the GluN2A P1199Rfs*32-containing receptors traffic efficiently to the postsynaptic membrane but have increased extra-synaptic expression relative to WT GluN2A-containing NMDARs. Using in silico predictions, we hypothesized that the mutant would lose all PDZ interactions, except for the recycling protein Scribble1. Indeed, we observed impaired binding to the scaffolding protein postsynaptic protein-95 (PSD-95); however, we found the mutant interacts with Scribble1, which facilitates the recycling of both the mutant and the WT GluN2A. Finally, we found that neurons expressing GluN2A P1199Rfs*32 have fewer synapses and decreased spine density, indicating compromised synaptic transmission in these neurons. Overall, our data show that GluN2A P1199Rfs*32 is a loss-of-function variant with altered membrane localization in neurons and provide mechanistic insight into disease etiology.

Accurate staging of non-metastatic colon cancer with CT: the importance of training and practice for experienced radiologists and analysis of incorrectly staged cases

PURPOSE

To investigate whether locoregional staging of colon cancer by experienced radiologists can be improved by training and feedback to minimize the risk of over-staging into the context of patient selection for neoadjuvant therapy and to identify potential pitfalls of CT staging by characterizing pathologic traits of tumors that remain challenging for radiologists.

METHODS

Forty-five cases of stage I-III colon cancer were included in this retrospective study. Five experienced radiologists evaluated the CTs; 5 baseline scans followed by 4 sequential batches of 10 scans. All radiologists were trained after baseline scoring and 2 radiologists received feedback. The learning curve, diagnostic performance, reader confidence, and reading time were evaluated with pathologic staging as reference. Pathology reports and H&E slides of challenging cases were reviewed to identify potential pitfalls.

RESULTS

Diagnostic performance in distinguishing T1-2 vs. T3-4 improved significantly after training and with increasing number of reviewed cases. Inaccurate staging was more frequently related to under-staging rather than over-staging. Risk of over-staging was minimized to 7% in batch 3-4. N-staging remained unreliable with an overall accuracy of 61%. Pathologic review identified two tumor characteristics causing under-staging for T-stage in 5/7 cases: (1) very limited invasive part beyond the muscularis propria and (2) mucinous composition of the invading part.

CONCLUSION

The high accuracy and specificity of T-staging reached in our study indicate that sufficient training and practice of experienced radiologists can ensure high validity for CT staging in colon cancer to safely use neoadjuvant therapy without significant risk of over-treatment, while N-staging remained unreliable.

Treatment of early-stage mycosis fungoides: results from the PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study

BACKGROUND

The PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study is a prospective analysis of an international database. Here we examine front-line treatments and quality of life (QoL) in patients with newly diagnosed mycosis fungoides (MF).

OBJECTIVES

To identify (i) differences in first-line approaches according to tumour-nodes-metastasis-blood (TNMB) staging; (ii) parameters related to a first-line systemic approach and (iii) response rates and QoL measures.

METHODS

In total, 395 newly diagnosed patients with early-stage MF (stage IA-IIA) were recruited from 41 centres in 17 countries between 1 January 2015 and 31 December 2018 following central clinicopathological review.

RESULTS

The most common first-line therapy was skin-directed therapy (SDT) (322 cases, 81·5%), while a smaller percentage (44 cases, 11·1%) received systemic therapy. Expectant observation was used in 7·3%. In univariate analysis, the use of systemic therapy was significantly associated with higher clinical stage (IA, 6%; IB, 14%; IIA, 20%; IA-IB vs. IIA, P < 0·001), presence of plaques (T1a/T2a, 5%; T1b/T2b, 17%; P < 0·001), higher modified Severity Weighted Assessment Tool (> 10, 15%; ≤ 10, 7%; P = 0·01) and folliculotropic MF (FMF) (24% vs. 12%, P = 0·001). Multivariate analysis demonstrated significant associations with the presence of plaques (T1b/T2b vs. T1a/T2a, odds ratio 3·07) and FMF (odds ratio 2·83). The overall response rate (ORR) to first-line SDT was 73%, while the ORR to first-line systemic treatments was lower (57%) (P = 0·027). Health-related QoL improved significantly both in patients with responsive disease and in those with stable disease.

CONCLUSIONS

Disease characteristics such as presence of plaques and FMF influence physician treatment choices, and SDT was superior to systemic therapy even in patients with such disease characteristics. Consequently, future treatment guidelines for early-stage MF need to address these issues.

Should we be imaging lymph nodes at initial diagnosis of early-stage mycosis fungoides? Results from the PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) international study

BACKGROUND

Early-stage mycosis fungoides (MF) includes involvement of dermatopathic lymph nodes (LNs) or early lymphomatous LNs. There is a lack of unanimity among current guidelines regarding the indications for initial staging imaging in early-stage presentation of MF in the absence of enlarged palpable LNs.

OBJECTIVES

To investigate how often imaging is performed in patients with early-stage presentation of MF, to assess the yield of LN imaging, and to determine what disease characteristics promoted imaging.

METHODS

A review of clinicopathologically confirmed newly diagnosed patients with cutaneous patch/plaque (T1/T2) MF from PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) data.

RESULTS

PROCLIPI enrolled 375 patients with stage T1/T2 MF: 304 with classical MF and 71 with folliculotropic MF. Imaging was performed in 169 patients (45%): 83 with computed tomography, 18 with positron emission tomography-computed tomography and 68 with ultrasound. Only nine of these (5%) had palpable enlarged (≥ 15 mm) LNs, with an over-representation of plaques, irrespectively of the 10% body surface area cutoff that distinguishes T1 from T2. Folliculotropic MF was not more frequently imaged than classical MF. Radiologically enlarged LNs (≥ 15 mm) were detected in 30 patients (18%); only seven had clinical lymphadenopathy. On multivariate analysis, plaque presentation was the sole parameter significantly associated with radiologically enlarged LNs. Imaging of only clinically enlarged LNs upstaged 4% of patients (seven of 169) to at least IIA, whereas nonselective imaging upstaged another 14% (24 of 169). LN biopsy, performed in eight of 30 patients, identified N3 (extensive lymphomatous involvement) in two and N1 (dermatopathic changes) in six.

CONCLUSIONS

Physical examination was a poor determinant of LN enlargement or involvement. Presence of plaques was associated with a significant increase in identification of enlarged or involved LNs in patients with early-stage presentation of MF, which may be important when deciding who to image. Imaging increases the detection rate of stage IIA MF, and identifies rare cases of extensive lymphomatous nodes, upstaging them to advanced-stage IVA2.

Improving clinical management of colon cancer through CONNECTION, a nation-wide colon cancer registry and stratification effort (CONNECTION II trial): rationale and protocol of a single arm intervention study

BACKGROUND

It is estimated that around 15-30% of patients with early stage colon cancer benefit from adjuvant chemotherapy. We are currently not capable of upfront selection of patients who benefit from chemotherapy, which indicates the need for additional predictive markers for response to chemotherapy. It has been shown that the consensus molecular subtypes (CMSs), defined by RNA-profiling, have prognostic and/or predictive value. Due to postoperative timing of chemotherapy in current guidelines, tumor response to chemotherapy per CMS is not known, which makes the differentiation between the prognostic and predictive value impossible. Therefore, we propose to assess the tumor response per CMS in the neoadjuvant chemotherapy setting. This will provide us with clear data on the predictive value for chemotherapy response of the CMSs.

METHODS

In this prospective, single arm, multicenter intervention study, 262 patients with resectable microsatellite stable cT3-4NxM0 colon cancer will be treated with two courses of neoadjuvant and two courses of adjuvant capecitabine and oxaliplatin. The primary endpoint is the pathological tumor response to neoadjuvant chemotherapy per CMS. Secondary endpoints are radiological tumor response, the prognostic value of these responses for recurrence free survival and overall survival and the differences in CMS classification of the same tumor before and after neoadjuvant chemotherapy. The study is scheduled to be performed in 8-10 Dutch hospitals. The first patient was included in February 2020.

DISCUSSION

Patient selection for adjuvant chemotherapy in early stage colon cancer is far from optimal. The CMS classification is a promising new biomarker, but a solid chemotherapy response assessment per subtype is lacking. In this study we will investigate whether CMS classification can be of added value in clinical decision making by analyzing the predictive value for chemotherapy response. This study can provide the results necessary to proceed to future studies in which (neo) adjuvant chemotherapy may be withhold in patients with a specific CMS subtype, who show no benefit from chemotherapy and for whom possible new treatments can be investigated.

TRIAL REGISTRATION

This study has been registered in the Netherlands Trial Register (NL8177) at 11-26-2019, https://www.trialregister.nl/trial/8177 . The study has been approved by the medical ethics committee Utrecht (MEC18/712).

Diabetic nephropathy produces alterations in the tissue expression profile of the orphan receptors GPR149, GPR153, GPR176, TAAR3, TAAR5 and TAAR9 in Wistar rats

Diabetes mellitus is a debilitating health care problem affecting 382 million people around the world and one of the most common complications is diabetic nephropathy. For this reason, it is important to try to identify new mechanisms that could be involved in diabetes. A new class of receptors has been reported, called orphan receptors because the associated ligand and signaling cascades are unknown. These receptors could be an important source of targets for the treatment of many diseases such as diabetes and its associated complications like diabetic nephropathy. Therefore, the aim of this work was to study expression of the orphan receptors GPR149, GPR153, GPR176, TAAR3, TAAR5 and TAAR9 in the kidney of diabetic rats. We used male Wistar rats at 10-12 weeks of age. Diabetes was induced by a single dose of streptozotocin (60 mg/kg i.p.). After 4 weeks, tissues were obtained, and the expression of the mRNAs was measured by RT-PCR. Our results showed that the orphan receptors are expressed in a different way in the kidney. In conclusion, we suggest that orphan receptors could be involved in the development of diabetic nephropathy.

Impact of immunogenicity on efficacy and tolerability of tumour necrosis factor inhibitors: pooled analysis of biosimilar studies in rheumatoid arthritis

Objective: SB4, SB2, and SB5 are biosimilars of etanercept (ETN), infliximab (INF), and adalimumab (ADA), respectively. This pooled analysis evaluated the immunogenicity of these treatments across three phase III randomized controlled trials of patients with rheumatoid arthritis (RA). Methods: Patients had to have at least one anti-drug antibody (ADAb) assessment up to the time of the primary endpoint from each study (week 24 in SB4 and SB5 studies; week 30 in SB2 study). The effect of ADAbs on American College of Rheumatology 20% (ACR20) response and the incidences of injection-site reactions (ISRs)/infusion-related reactions (IRRs) were evaluated. Results: The study included 1709 patients. The cumulative incidences of ADAbs were 30.3% in the all-treatments-combined group, 29.1% in the biosimilars combined group, and 31.5% in the reference products combined group. ACR20 response rates were significantly lower in ADAb-positive patients in the all-treatments-combined [odds ratio (95% confidence interval) 1.77 (1.37, 2.27), p < 0.0001], biosimilars combined [2.24 (1.53, 3.30), p < 0.0001], and reference products combined [1.49 (1.06, 2.09), p = 0.0225] groups. ADAb-positive patients also had a higher likelihood of developing ISRs/IRRs in the all-treatments-combined group [0.56 (0.31, 1.01), p = 0.0550], predominantly due to the results observed with SB2 + INF combined rather than with SB4 + ETN or SB5 + ADA combined. Conclusion: In this pooled analysis, ADAbs were associated with reduced efficacy in patients with RA treated with biosimilars (SB4, SB2, and SB5) or their reference products (ETN, INF, and ADA). ADAbs were associated with an increased incidence of ISRs/IRRs in those treated with SB2 + INF. Clinical trial registration numbers: NCT01936181 (SB2 study), NCT01895309 (SB4 study), and NCT02167139 (SB5 study).

Phenotypic and genotypic characterization of meningococcal isolates in Tunis, Tunisia: High diversity and impact on vaccination strategies

OBJECTIVES

The aim of this study was to characterize Neisseria meningitidis (Men) isolates in Tunisian paediatric patients with invasive meningococcal disease (IMD) in order to target therapeutic and preventive strategies.

METHODS

Fifty-nine isolates of Men and four cerebrospinal fluid samples that were culture-negative but Men-positive by PCR (NC-MenPPCR) (2009-2016) were collected from IMD patients. Isolates were analysed for their antimicrobial susceptibility. Whole-genome sequencing (WGS) was used to characterize isolates and multilocus sequence typing for NC-MenPPCR. Coverage of Men serogroup B (MenB) was determined by Genetic Meningococcal Antigen Typing System (gMATS) and fHbp expression by ELISA.

RESULTS

MenB was the predominant type (88.9%). The majority of isolates (81%) had reduced susceptibility to penicillin G with altered penA alleles. The clonal complex CC461 (27.1%) was the most frequent. Among the MenB vaccine targets neisserial heparin binding antigen (NHBA) and fHbp, the predominant variants were NHBA118 (30.8%) and fHbp peptide 47 (25%), respectively. The nadA gene was present in 17.3% of isolates. Using gMATS, 36.5% of MenB were predicted to be covered by the 4CMenB vaccine. ELISA showed that 92.4% of the MenB were expected to be killed by anti-fHbp antibodies.

CONCLUSIONS

MenB was the leading serogroup in IMD, and more than 90% had a sufficient level of fHbp expression for vaccine coverage. The study results will be useful for the Tunisian vaccination programme.

The PROCLIPI international registry of early-stage mycosis fungoides identifies substantial diagnostic delay in most patients

BACKGROUND

Survival in mycosis fungoides (MF) is varied and may be poor. The PROCLIPI (PROspective Cutaneous Lymphoma International Prognostic Index) study is a web-based data collection system for early-stage MF with legal data-sharing agreements permitting international collaboration in a rare cancer with complex pathology. Clinicopathological data must be 100% complete and in-built intelligence in the database system ensures accurate staging.

OBJECTIVES

To develop a prognostic index for MF.

METHODS

Predefined datasets for clinical, haematological, radiological, immunohistochemical, genotypic, treatment and quality of life are collected at first diagnosis of MF and annually to test against survival. Biobanked tissue samples are recorded within a Federated Biobank for translational studies.

RESULTS

In total, 430 patients were enrolled from 29 centres in 15 countries spanning five continents. Altogether, 348 were confirmed as having early-stage MF at central review. The majority had classical MF (81·6%) with a CD4 phenotype (88·2%). Folliculotropic MF was diagnosed in 17·8%. Most presented with stage I (IA: 49·4%; IB: 42·8%), but 7·8% presented with enlarged lymph nodes (stage IIA). A diagnostic delay between first symptom development and initial diagnosis was frequent [85·6%; median delay 36 months (interquartile range 12-90)]. This highlights the difficulties in accurate diagnosis, which includes lack of a singular diagnostic test for MF.

CONCLUSIONS

This confirmed early-stage MF cohort is being followed-up to identify prognostic factors, which may allow better management and improve survival by identifying patients at risk of disease progression. This study design is a useful model for collaboration in other rare diseases, especially where pathological diagnosis can be complex.

Abstract P6-17-09: Event-free survival by ADCC status from a follow-up study comparing SB3 (trastuzumab biosimilar) with reference trastuzumab for HER2 positive breast cancer in neoadjuvant setting

Background: SB3 has been approved by the European Commission as a biosimilar of reference trastuzumab (TRZ). Equivalent breast pathologic complete response (bpCR) rate and comparable event-free survival (EFS) and overall survival between SB3 and TRZ have been reported.1-3 Upon monitoring quality attributes of TRZ for the development of SB3, a marked downward shift in antibody-dependent cell-mediated cytotoxicity activities (ADCC) was observed in TRZ lots with expiry dates from Aug 2018 to Dec 2019.4 Some of these lots were used in this study. The objective of this report is to evaluate event-free survival by ADCC status from an additional one-year follow-up study.

Methods: Patients with HER2 positive early or locally advanced breast cancer were randomly assigned to receive SB3 or TRZ in neoadjuvant setting concurrently with chemotherapy. Patients then underwent surgery followed by adjuvant SB3 or TRZ. After completion of therapy, patients from selected countries participated in a long-term follow-up study. In TRZ, patients exposed to at least one shifted ADCC lot and those not exposed to shifted ADCC lot during neoadjuvant period were considered as “Exposed” and “Unexposed,” respectively. EFS was defined as the time from the date of randomization to the date when the first event occurred. An event was defined as disease recurrence or progression (local, regional, distant or contralateral) or death due to any cause. EFS after additional one-year follow-up was analyzed by ADCC status in the long-term follow-up set (LFS).

Results: A total of 367 patients (SB3, N=186; TRZ, N=181) were included in the LFS. Within TRZ, 55 patients were Unexposed and 126 patients were Exposed. At a median follow-up duration of 30.1 months in SB3 and 30.2 months in TRZ from initiation of study treatment, 4.8% patients in SB3, 3.6% in Unexposed and 10.3% in Exposed experienced events. 4.3% patients in SB3, 1.8% in Unexposed and 9.5% in Exposed experienced recurrence after surgery (Table). Two-year EFS rate was 96.7% in SB3, 98.2% in Unexposed and 92.5% in Exposed.

Conclusion: A significantly higher proportion of patients experienced events in Exposed compared to Unexposed (HR 0.07, 95% CI 0.01-0.58, p-value=0.0137). No significant difference in EFS was found between SB3 and Unexposed. Although this study has a relatively short follow-up and has not been powered to evaluate the impact of ADCC on survival, these results suggest a possible correlation between ADCC and clinical efficacy. Further long-term results will follow.

Summary of Event-free Survival (LFS)  TRZEFS Hazard ratio (95% CI), p-value SB3 N=186All N=181Unexposed N=55Exposed N=126SB3 vs TRZ AllSB3 vs TRZ UnexposedTRZ Unexposed vs TRZ ExposedPatients with event, n (%)9 (4.8%)15 (8.3%)2 (3.6%)13 (10.3%)0.49 (0.21, 1.14) p=0.09751.19 (0.23, 6.18) p=0.83760.07 (0.01, 0.58) p=0.0137Recurrence after surgery8 (4.3%)13 (7.2%)1 (1.8%)12 (9.5%)   Progression before surgery1 (0.5%)1 (0.6%)1 (1.8%)0 (0.0%)   Death0 (0.0%)1 (0.6%)0 (0.0%)1 (0.8%)   

Reference:

1. Pivot X et al. J Clin Oncol. 2018; 36:968-74

2. Pivot X et al. Eur J Cancer. 2018; 93:19-27

3. Pivot X et al. J Clin Oncol. 2018; 36 (suppl; abstr e12631)

4. Kim S et al. MAbs. 2017; 9:704-14

Citation Format: Pegram MD, Pivot X, Cortes J, Curigliano G, Yoon Y, Lim J, Song S, Hong E. Event-free survival by ADCC status from a follow-up study comparing SB3 (trastuzumab biosimilar) with reference trastuzumab for HER2 positive breast cancer in neoadjuvant setting [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-09.

An evaluation of the effects of intensity and duration on outcomes across treatment domains for children with autism spectrum disorder

Applied behavior analysis (ABA) is considered an effective treatment for individuals with autism spectrum disorder (ASD), and many researchers have further investigated factors associated with treatment outcomes. However, few studies have focused on whether treatment intensity and duration have differential influences on separate skills. The aim of the current study was to investigate how treatment intensity and duration impact learning across different treatment domains, including academic, adaptive, cognitive, executive function, language, motor, play, and social. Separate multiple linear regression analyses were used to evaluate these relationships. Participants included 1468 children with ASD, ages 18 months to 12 years old, M=7.57 years, s.d.=2.37, who were receiving individualized ABA services. The results indicated that treatment intensity and duration were both significant predictors of mastered learning objectives across all eight treatment domains. The academic and language domains showed the strongest response, with effect sizes of 1.68 and 1.85 for treatment intensity and 4.70 and 9.02 for treatment duration, respectively. These findings are consistent with previous research that total dosage of treatment positively influences outcomes. The current study also expands on extant literature by providing a better understanding of the differential impact that these treatment variables have across various treatment domains.

Possible involvement of orphan receptors GPR88 and GPR124 in the development of hypertension in spontaneously hypertensive rat

Hypertension (HBP) is a chronic disease characterized by increased blood pressure, which despite several treatments maintains a high morbi-mortality, which suggests that there are other mechanisms involved in this pathology, within which the orphan receptors could be candidates for the treatment of the HBP; these receptors are called orphan receptors because their ligand is unknown. These receptors have been suggested to participate in some pathologies because they are associated with various systems such as GPR88, which has been linked to the dopaminergic system, and GPR124 with angiogenesis, suggesting that these receptors could take part in HBP. Hence, the aim of this work was to study the expression of orphan receptors GPR88 and GPR124 in various tissues of normotensive and hypertensive rats. We used Wistar Kyoto (WKY) and spontaneously hypertensive rat (SHR) of 6-8 and 10-12 weeks of age and we determined systolic blood pressure (SBP), heart rate, as well as mRNA of GPR88 and GPR124 receptors by reverse transcription polymerase chain reaction (RT-PCR) in the aorta, heart, kidney, and brain. Our results showed that GPR88 and GPR124 were expressed in all analyzed tissues, but their expression is dependent on the age and development of HBP because their expression tends to be modified as HBP is established. Therefore, we conclude that GPR88 and GPR124 receptors may be involved in the development or maintenance of high blood pressure.

Changes in protein and gene expression of angiotensin II receptors (AT1 and AT2) in aorta of diabetic and hypertensive rats

Diabetes and hypertension have been associated with cardiovascular diseases and stroke. Some reports have related the coexistence of hypertension and diabetes with increase in the risk of developing vascular complications. Recently some studies have shown results suggesting that in the early stages of diabetes and hypertension exist a reduced functional response to vasopressor agents like angiotensin II (Ang II), which plays an important role in blood pressure regulation mechanism through the activation of its AT1 and AT2 receptors. For that reason, the aim of this work was to study the gene and protein expression of AT1 and AT2 receptors in aorta of diabetic SHR and WKY rats. Diabetes was induced by the administration of streptozotocin (60 mg/kg i.p.). After 4 weeks of the onset of diabetes, the protein expression was obtained by western blot and the mRNA expression by RT-PCR. Our results showed that the hypertensive rats have a higher mRNA and protein expression of AT1 receptors than normotensive rats while the AT2 expression remained unchanged. On the other hand, the combination of diabetes and hypertension increased the mRNA and protein expression of AT1 and AT2 receptors significantly. In conclusion, our results suggest that diabetes with hypertension modifies the mRNA and protein expression of AT1 and AT2 receptors. However, the overexpression of AT2 could be associated with the reduction in the response to Ang II in the early stage of diabetes.

SOX17 is expressed in regenerating oligodendrocytes in experimental models of demyelination and in multiple sclerosis

We have previously demonstrated that Sox17 expression is prominent at developmental stages corresponding to oligodendrocyte progenitor cell (OPC) cycle exit and onset of differentiation, and that Sox17 promotes initiation of OPC differentiation. In this study, we examined Sox17 expression and regulation under pathological conditions, particularly in two animal models of demyelination/remyelination and in post-mortem multiple sclerosis (MS) brain lesions. We found that the number of Sox17 expressing cells was significantly increased in lysolecithin (LPC)-induced lesions of the mouse spinal cord between 7 and 30 days post-injection, as compared with controls. Sox17 immunoreactivity was predominantly detected in Olig2(+) and CC1(+) oligodendrocytes and rarely in NG2(+) OPCs. The highest density of Sox17(+) oligodendrocytes was observed at 2 weeks after LPC injection, coinciding with OPC differentiation. Consistent with these findings, in cuprizone-treated mice, Sox17 expression was highest in newly generated and in maturing CC1(+) oligodendrocytes, but low in NG2(+) OPCs during the demyelination and remyelination phases. In MS tissue, Sox17 was primarily detected in actively demyelinating lesions and periplaque white matter. Sox17 immunoreactivity was co-localized with NOGO-A+ post-mitotic oligodendrocytes both in active MS lesions and periplaque white matter. Taken together, our data: (i) demonstrate that Sox17 expression is highest in newly generated oligodendrocytes under pathological conditions and could be used as a marker of oligodendrocyte regeneration, and (ii) are suggestive of Sox17 playing a critical role in oligodendrocyte differentiation and lesion repair.

A single oral dose of fructose induces some features of metabolic syndrome in rats: role of oxidative stress

BACKGROUND AND AIMS

To determine if a single oral dose of fructose to rats reproduces some features of metabolic syndrome observed after chronic administration and if so, to investigate its mechanisms.

METHODS AND RESULTS

Systolic blood pressure was measured in rats before and after oral administration of fructose, and in animals pretreated with lipoic acid, methyldopa, losartan or streptozotocin. In other rats, glucose, insulin, uric acid, and insulin sensitivity index, were determined before and after fructose or lipoic acid plus fructose. Glutathione was measured in liver before and after fructose administration. In aortic rings from other rats, incubation with mannitol, fructose, or fructose plus lipoic acid was evaluated on the relaxation by acetylcholine. Fructose produced a moderate increase in blood pressure, which was prevented by lipoic acid or streptozotocin. Methyldopa and losartan decreased the pressor response minimally. Fructose increased oxidized glutathione, plasma glucose, insulin and uric acid, and diminished the insulin sensitivity index, and the reduced glutathione. Lipoic acid prevented hyperglycemia and hyperuricemia, and improved the insulin sensitivity index. Finally, endothelial dysfunction was prevented by lipoic acid.

CONCLUSION

A single dose of fructose reproduces some of the features of metabolic syndrome, most changes were caused by oxidative stress and insulin resistance.

Weight loss induced by 6-month lifestyle intervention improves early endothelial activation and fibrinolysis in obese adolescents

BACKGROUND

Adolescent obesity is associated with an increased risk of adult obesity and subsequent cardiovascular diseases. The present study aimed to assess the effect of weight loss after 6-month lifestyle intervention in obese adolescents on biomarkers of endothelial activation and fibrinolytic system.

METHODS

Eighty-five obese adolescents aged 10 to 16 years were assigned to a 6-month lifestyle intervention and 61 completed the programme. We examined the effect of the intervention on adhesion molecules (selectin E, soluble intercellular adhesion molecule 1 and soluble vascular adhesion molecule 1) and fibrinolytic parameters [plasminogen activator inhibitor-1 (PAI-1) and fibrinogen]. Thirty-six lean adolescents were studied only at baseline as a comparison group.

RESULTS

Compared with lean participants, obese adolescents at baseline demonstrated significantly higher levels of triglycerides, glucose, insulin, homeostasis model assessment, soluble intercellular adhesion molecule 1, PAI-1 and fibrinogen. After 6-month lifestyle intervention, those obese adolescents with decreased standard deviation score-body mass index (SDS-BMI) displayed significant decreases in insulin (19.2 ± 11.2 vs. 26.8 ± 13.2 mU/L, P≤ 0.01), homeostasis model assessment (4.24 ± 3.19 vs. 6.58 ± 4.08, P≤ 0.01), selectin E (100.2 ± 60.9 vs. 116.0 ± 69.0 ng/mL, P≤ 0.01) and PAI-1 (39.6 ± 38.0 vs. 51.8 ± 25.6 ng/mL, P≤ 0.05) with respect to the baseline levels. No changes in these parameters were observed in the obese adolescents with stable or increased SDS-BMI. The changes of triglycerides after intervention in subgroup with decreased SDS-BMI were significantly greater than those in subgroup with stable SDS-BMI.

CONCLUSIONS

The present study demonstrated increased endothelial activation and impairment of the fibrinolytic system in early life, which is in part reversible by a 6-month lifestyle intervention.

Current practice of exercise stress testing among pediatric cardiology and pulmonology centers in the United States

The objective of this study was to characterize current practice patterns for clinical exercise stress testing (EST) in children in the United States. We conducted a survey of 109 pediatric cardiology programs and 91 pediatric pulmonology programs at children's hospitals or university hospitals in the United States. A total of 115 programs from 88 hospitals responded (response rate, 58%). A higher percentage of cardiology programs (98.7%) have exercise laboratories compared with pulmonology programs (77.5%). Sixty-three percent of respondents have both a treadmill and a cycle ergometer. A larger proportion of respondents (76%) rely primarily or exclusively on treadmill, whereas a smaller number use cycle ergometer (24%). Sixty-seven percent of respondents reported that they include metabolic measurements in EST protocols. Respondents have varying minimum age criteria for EST, with 9% reporting < or = 4 years, 25% reporting 5 years, 31% reporting 6 years, 16% reporting 7 years, and 20% reporting > or =8 years. Programs using cycle ergometers tend to test children at a younger age and to measure metabolic parameters. Seventy-nine percent of respondents use Bruce and modified Bruce protocols. Institutional protocols are used by 14%. Ninety percent of respondents use technicians to perform EST and 8% use nurses, but 76% require physician presence during testing. The majority of respondents (57%) perform < 100 pediatric tests per year. There are wide variations in the current practice of EST among pediatric subspecialty programs in the United States. Treadmills are used more frequently than cycle ergometers, and Bruce and modified Bruce protocols are commonly used. Most survey respondents measure metabolic parameters during EST.

Comparison of histologic grade between initial and follow-up biopsy in untreated, low to intermediate grade, localized prostate cancer

OBJECTIVE

To examine the change of histologic grade of untreated, low to intermediate grade, clinically localized prostate cancer over time on repeat prostate biopsy.

METHODS AND MATERIALS

In a prospective single-arm cohort study, patients were managed with observation alone unless they met pre-defined criteria of disease progression (PSA, clinical or histologic progression). Sixty-seven (54%) of a total of 123 eligible patients underwent follow-up prostate biopsy. Median time to the follow-up biopsy was 22 months (range: 7-60).

RESULTS

On the follow-up biopsy, Gleason score was unchanged in 20 patients (30%), upgraded in 19 (28%), and downgraded in 27 (40%). Twenty-one (31%) had no malignancy on the follow-up biopsy. Sixteen (37%) of 43 patients with < or = 2 positive cores on the initial biopsy had negative follow-up biopsy, while only 2 (11%) out of 18 with > or = 3 positive cores on the initial biopsy did. Five (7%) patients were upgraded to Gleason score 8. There was no correlation between the extent of grade change and baseline variables (age, clinical stage, and initial PSA) as well as PSA doubling time.

CONCLUSIONS

There was no consistent histologic upgrade on the follow-up biopsy at a median of 22 months in untreated, low to intermediate grade, clinically localized prostate cancer.

Is there a progression of histologic grade from radical prostatectomy to local recurrence in patients with clinically isolated local recurrence following surgery?

OBJECTIVE

To evaluate whether there is any histologic progression from radical prostatectomy (RP) to local recurrence in patients with clinically isolated local recurrence following RP.

METHODS AND MATERIALS

A total of 43 patients with clinically isolated, biopsy proven, local recurrence following RP were retrospectively analyzed with respect to the change in Gleason score (GS) from RP to local recurrence. Central pathology review was undertaken for both RP and local recurrence biopsy specimens. The changes in primary and secondary Gleason grade (GG), and any potential correlation between the extent of GS change and other variables were also examined.

RESULTS

Median age at the time of local recurrence was 67 years (range: 55-78). Median interval between RP and local recurrence was 3.6 years (range: 0.3-17.7). Eight had a short course (<3 months) of hormone therapy prior to RP. Initial GS of RP specimens was 5, 6, 7, 8, and 9 in 1, 3, 29, 1, and 9 patients, respectively. At the time of local recurrence, GS was upgraded in 13, unchanged in 23, and downgraded in 7. The extent of GS change was correlated with the interval between RP and local recurrence, but not with pathological T stage or age.

CONCLUSION

There was no statistically significant change in GS from RP to local recurrence, although there was a trend toward a higher GS at the time of local recurrence. The extent of GS change was associated positively with the elapsed time to local recurrence.

Further evidence that the discriminative stimulus properties of indorenate are mediated by 5-HT 1A/1B/2C receptors

Indorenate (5-methoxytryptamine beta-methylcarboxylate, INDO) is a serotonin (5-hydroxytryptamine, 5-HT) agonist that has affinity for 5-HT(1A/1B/2C) receptors. Unlike other anxiolytics such as 5-HT receptor agonists, INDO may not share tolerance or dependency with the benzodiazepine anxiolytics. It has been reported that the discriminative stimulus properties of 5-HT(1A/1B/2C) agonists, but not those of 5-HT(3/4) agonists, generalize to INDO. Therefore, the aim of the present study was to obtain further evidence on the differential involvement of 5-HT(1A/1B/2C) receptors in the discriminative stimulus properties of INDO by evaluating its interactions with antagonists of the 5-HT(1A), 5-HT(1B), 5-HT(2C), and 5-HT(3/4) receptor subtypes. Rats were trained to discriminate INDO from saline in a conditioned taste aversion paradigm. For Group D(+)S(-), administration of INDO signalled that saccharin flavour was followed by LiCl, while injection of vehicle signalled safe consumption of saccharin solution. Group D(-)S(+) had the contingencies reversed. After this training, rats had generalization tests where INDO administration was preceded by different doses of the following antagonists: WAY100635 (5-HT(1A)), NAN190 (5-HT(1A)), methiothepin (5-HT(1A/1B/2C)), GR127935 (5-HT(1B/1D)), ketanserin (5-HT(2A/2C)), ritanserin (5-HT(2C/2A)), mesulergine (5-HT(2C/2A)), metergoline (5-HT(2C/2A)), SB206553 (5-HT(2B/2C)), and tropisetron (5-HT(3/4)). In Group D(+)S(-), the order of potency to block the discriminative stimulus properties of INDO was WAY100635>ketanserin>ritanserin>GR127935>mesulergine congruent with SB206553>metergoline>methiothepin>NAN190, while in Group D(-)S(+), the order was WAY100635>GR127935>ketanserin>ritanserin>mesulergine congruent with SB206553>metergoline>methiothepin>NAN190. Tropisetron did not produce any alteration of the discriminative control by INDO. These results suggest that the discriminative signal of INDO is mediated by 5-HT(1A/2C/1B) receptors and that blockade of any of its components produces a degradation of its discriminative effects.

Sympathetic blockade significantly improves cardiovascular alterations immediately after spinal cord injury in rats

Immediately after an experimental spinal cord injury (SCI) in rats, there is a large fall in mean arterial pressure (MAP) and heart rate (HR), followed by an abrupt increase in MAP. To better understand the mechanism involved in these early cardiovascular alterations, we tested the effect of treatment with ganglionic and sympathetic blockers in anesthetized rats subjected to T-5 SCI. Fall in MAP was partially diminished by propranolol and pentolinium, while increase in MAP was abolished by propranolol and pentolinium. Adrenalectomy did not diminish the fall in MAP and HR, however, the increase in MAP was significantly reduced. Likewise, propranolol and pentolinium completely abolished the effects in HR. These data suggest that the early cardiovascular alterations secondary to SCI results from an increased parasympathetic activity and a sympathetic withdrawal.

Thiazide-sensitive cotransporter mRNA expression is not altered in three models of hypertension

BACKGROUND/AIMS

Several lines of evidence support that the kidney is involved in the increase of arterial blood pressure, and some genetic studies suggest that the thiazide-sensitive Na+:Cl- cotransporter could be implicated in the development of hypertension. In the present study, we analyzed the Na+:Cl- cotransporter mRNA levels in the kidney during the development of hypertension in three experimental models.

METHODS

The first model included 18 spontaneously hypertensive rats studied at 4, 10, and 16 weeks of age. The second model included 28 Wistar rats with two-kidney, one-clip Goldblatt hypertension studied at 7, 14, 21, and 28 days. The third model included 6 Wistar rats treated with N(G)-nitro-L-arginine methyl ester during 10 days. Respective controls were studied for all models. At the end of each experimental period, the systolic blood pressure was measured in the tail by plethysmography. Individual renal cortex total RNA was extracted, and the mRNA levels of the thiazide-sensitive Na+:Cl- cotransporter were assessed following a semiquantitative RT-PCR strategy.

RESULTS

All experimental models developed systemic hypertension. However, the level of mRNA expression of the Na+:Cl- cotransporter did not change in any of the models studied as compared with their respective controls.

CONCLUSION

Our results suggest that a change in mRNA levels of the thiazide-sensitive Na+:Cl- cotransporter is not associated with the development of hypertension in spontaneously hypertensive rats, in rats with renovascular hypertension, nor in rats with hypertension induced by nitric oxide synthesis inhibition.

Anticonvulsant properties and bio-guided isolation of palmitone from leaves of Annona diversifolia

The activity-guided fractionation of the ethanol extract of leaves of Annona diversifolia Saff., led to the isolation of palmitone (16-hentriacontanone) as the only anticonvulsant active compound. This aliphatic ketone was highly effective to diminish pentylenetetrazole (PTZ)-induced clonic-tonic seizures and toxicity. Also, it produced a prolongation of the latency for onset of seizures and a reduction of the death rate produced by 4-aminopyridine (4-AP) and bicuculline (BIC). However, it was inactive to inhibit the kainic acid (KA)- and strychnine (STC)-induced seizures. Palmitone did not produce motor incoordination and loss of righting reflex which are used as signs of neurological impairment. Palmitone (ED50 = 1.85 mg/kg) proved to be a more potent antiepileptic drug against the PTZ-induced seizures than etosuximide (ED50 = 59.6 mg/kg), sodium valproate (ED50 = 63 mg/kg), and carbamazepine (ED50 > 300 mg/kg) and it was only four-fold less potent than diazepam (ED50 = 0.48 mg/kg). The pharmacological profile of palmitone suggests that this compound could be acting on the GABAergic inhibitory system.

Discriminative stimulus properties of indorenate in a conditioned taste aversion paradigm

Indorenate (5-methoxytryptamine beta-methylcarboxylate, INDO) is a serotonin (5-hydroxytryptamine, 5-HT) agonist that has affinity for 5-HT(1A/1B/2C) receptors. It possesses anxiolytic and antihypertensive actions mediated by 5-HT(1A) receptors and anorectic activity mediated by 5-HT(2C/1B) receptors. This study examined whether INDO may exert discriminative control using a conditioned taste aversion (CTA) paradigm, and whether differential participation of 5-HT receptor subtypes may be involved in its cue. Male Wistar rats trained to drink their daily water in a 30-min period were trained to discriminate INDO from saline. One group received the intraperitoneal administration of INDO (10.0 mg/kg) before saccharin-LiCl pairings; on alternate days, rats received saline before the saccharin-saline pairings (Group D(+)S(-)). The other group had the contingencies reversed (i.e., the administration of INDO preceded saccharin-saline pairings: Group D(-)S(+)). In two-bottle generalization tests (one bottle containing saccharin, the other plain water), the preference for saccharin was evaluated after different doses of INDO, [3H]-8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT) (5-HT(1A)), buspirone (5-HT(1A)), RU24969 (5-HT(1A/1B)), TFMPP (5-HT(1B/2C)), MK212 (5-HT(2C)), alpha-Me-5-HT (5-HT(2C/2A)), 2-Me-5-HT (5-HT(3)) and cisapride (5-HT(4)). The results showed that INDO, RU24969, TFMPP, alpha-Me-5-HT and MK 212 produced a dose-dependent generalization; 8-OH-DPAT and buspirone produced only partial generalization, while 2-Me-5-HT and cisapride did not produce generalization. The results indicate that INDO administration may exert discriminative control over saccharin preference mediated mainly by 5-HT(1B/2C) receptors, but with an important contribution of 5-HT(1A) receptors.

Mechanisms involved in the cardiovascular alterations immediately after spinal cord injury

The early cardiovascular effects resulting from an acute spinal cord injury (SCI) produced by a contusion procedure at T5-T6 were evaluated in anaesthetized rats. The mean arterial pressure (MAP) and heart rate (HR) were measured during one hour after the injury. A marked decrease in MAP and HR was observed immediately after injury, followed by an abrupt increase in MAP. These changes were observed between 3 and 9 min and the basal values were recovered after 20 min. Fall in the MAP and HR and increase in MAP induced by SCI were abolished by atropine. The interruption of the parasympathetic outflow by vagotomy also significantly diminished the fall and increase in MAP and the fall in HR. Likewise, pre-treatment with nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) completely abolished the effects produced by SCI. These data suggest that after SCI the decrement in MAP and HR was probably due to acetylcholine release from parasympathetic fibers and NO from endothelial source probably by a cholinergic stimulation. Additionally, the MAP increase observed was probably due to a reflex compensatory vasoconstriction.