L-Type calcium channel blockade reduces network activity in human epileptic hypothalamic hamartoma tissue

Purpose: Human hypothalamic hamartomas (HHs) are associated with gelastic seizures, intrinsically epileptogenic, and notoriously refractory to medical therapy. We previously reported that the L‐type calcium channel antagonist nifedipine blocks spontaneous firing and γ‐aminobutyric acid (GABA)_A–induced depolarization of single cells in HH tissue slices. In this study, we examined whether blocking L‐type calcium channels attenuates emergent activity of HH neuronal networks. Methods: A high‐density multielectrode array was used to record extracellular signals from surgically resected HH tissue slices. High‐frequency oscillations (HFOs, ripples and fast ripples), field potentials, and multiunit activity (MUA) were studied (1) under normal and provoked [4‐aminopyridine (4‐AP)] conditions; and (2) following nifedipine treatment. Key Findings: Spontaneous activity occurred during normal artificial cerebrospinal fluid (aCSF) conditions. Nifedipine reduced the total number and duration of HFOs, abolished the association of HFOs with field potentials, and increased the inter‐HFO burst intervals. Notably, the number of active regions was decreased by 45 ± 9% (mean ± SEM) after nifedipine treatment. When considering electrodes that detected activity, nifedipine increased MUA in 58% of electrodes and reduced the number of field potentials in 67% of electrodes. Provocation with 4‐AP increased the number of events and, as the number of electrodes that detected activity increased 248 ± 62%, promoted tissue‐wide propagation of activity. During provocation with 4‐AP, nifedipine effectively reduced HFOs, the association of HFOs with field potentials, field potentials, MUA, and the number of active regions, and limited propagation. Significance: This is the first study to report (1) the presence of HFOs in human subcortical epileptic brain tissue in vitro; (2) the modulation of “pathologic” high‐frequency oscillations (i.e., fast ripples) in human epileptic tissue by L‐type calcium channel blockers; and (3) the modulation of network physiology and synchrony of emergent activity in human epileptic tissue following blockade of L‐type calcium channels. Attenuation of activity in HH tissue during normal and provoked conditions supports a potential therapeutic usefulness of L‐type calcium channel blockers in epileptic patients with HH.     

Cutting-balloon angioplasty of resistant ureteral stenosis as bridge to stent insertion

Ureteral stenting is a routine, minimally invasive procedure performed for relief of benign or malignant obstruction. In case of ureteral stenosis, to allow a correct insertion of the stent, a predilatation of the ureter stenosis with a conventional balloon catheter can be necessary. In exceptional cases, it can be difficult to advance an 7-8 Fr JJ-catheter over a tight resistant ureter stenosis following unsuccessful high-pressure balloon dilatation. In the present report, we describe two cases of resistant ureter stenosis successfully dilated by a cutting-balloon following the failure of high-pressure balloon dilatation, allowing a correct and uncomplicated antegrade stent insertion.     

Predicting prostate cancer at rebiopsies in patients with high-grade prostatic intraepithelial neoplasia: a study on 546 patients

The aim of this study was to analyse the factors that predict the diagnosis of prostate cancer (PCa) after high-grade prostatic intraepithelial neoplasia (HGPIN). Data from 546 patients with HGPIN submitted up to a 6-month series of three rebiopsies, according to an institutional protocol, were reviewed. PCa has been found in 174 cases (31.8%), in 116 cases at the first and in 58 cases at a further rebiopsy. The risk of finding PCa at the first rebiopsy was correlated with the PSA value and with an anomalous digital rectal examination (DRE) at the time of the initial biopsy; the risk at a subsequent rebiopsy was correlated to the number of cores with HGPIN, with a cutoff of four, and to the ratio with the total number of cores ('PIN density'), with a cutoff of 50%, at the time of initial biopsy. A tailored protocol of controls can be suggested: (a) higher PSA value and/or anomalous DRE: early extended or saturation rebiopsy; (b) number of cores with HGPIN ≥4 and/or PIN density ≥50%: delayed rebiopsy; and (c) no risk factors: PSA and DRE controls.     

Adjuvant treatment of malignant melanoma: Where are we?

To date, no standard adjuvant therapy have increased overall survival in patients with malignant melanoma (MM). The effect of interferon alpha as a single agent or in combination has been widely explored in clinical trials. Critical reading of the major international randomised trials showed that response to interferon (IFN) in terms of improvement of overall survival (OS) may not be strictly correlated with the used dosage and that duration of therapy may impact disease-free survival (DFS) but not OS. Patients’ heterogeneity could be an explanation for the discordant data of the international literature. Indeed, majority of these studies started in late 1980s or early 1990s, when accurate staging procedure were not available yet. The adequate surgical treatment should be considered as an independent variable in the analysis of MM adjuvant protocols. Considering the treatment cost, which is the main goal: DFS, OS or quality of life? Answering these questions is difficult, but some considerations must be taken to put order in this field. Putting together data from all different studies, IFN therapy seems to protect MM patients from recurrences during the entire treatment period and a prolonged IFN therapy seems to improve DFS. The only positive result on OS was demonstrated for high-dose IFN (HD-IFN) in a single study (presenting a relatively short follow-up median) and not confirmed in a subsequent study from the same authors. Considering that low-dose interferon (LD-IFN) is tolerated much better than HD-IFN (about 10% versus more than 70% of cases with grade 3–4 toxicity, respectively), a prolonged LD-IFN (more than 2 years) may represent a reasonable opportunity for MM patients, also considering its advantageous cost-effectiveness. Conversely, considering the improvement of OS as the main target of MM adjuvant therapy, the “wait and watch” attitude remains the only approach to be pursued at present. It is a physician's choice.     

Quantitative assessment of WT1 gene expression after allogeneic stem cell transplantation is a useful tool for monitoring minimal residual disease in acute myeloid leukemia

Introduction: WT1 overexpression is described in several oncological diseases including acute myeloid leukemia (AML). Quantification of WT1 in bone marrow samples may be useful as a marker of minimal residual disease (MRD) and may predict the relapse of AML after allogeneic hematopoietic stem cell transplant (HSCT). Methods and results: The quantitative expression of WT1 was measured in 38 AML patients (16 males and 22 females) at diagnosis, at the time of transplant and after the allogeneic HSCT (at precise time points). All cases showed high WT1 expression levels at diagnosis with a mean of 4189 (SD 3325) and a median of 3495 (range 454–13923) copies WT1/10⁴Abl. At transplant, 25 patients (66%) were in complete cytologic remission (CcR) and 13 (34%) had refractory or relapsed AML. Bone marrow samples from patients transplanted in CcR showed significantly lower WT1 expression levels during HSCT compared with the samples from patients with a relapsed or refractory AML (P = 0.004). After HSCT, a rapid decline in WT1 expression levels was observed in all patients who attained or maintained a condition of CcR. Six of 38 patients (13%) relapsed after HSCT and all of them had an increase in WT1 expression at/or before relapse. Five of these six patients died of leukemia and one was successfully reinduced with donor lymphocyte infusion (DLI) + chemotherapy with a rapid reduction of WT1 levels. Besides, we found a complete concordance between WT1 expression levels and other disease markers (when available). Conclusions: In our experience, there was a complete concordance between WT1 expression levels (measured by quantitative RT‐PCR at precise time points) and status of AML before and after allogeneic HSCT. WT1 may be useful as a non‐specific leukemia marker for monitoring MRD and as a predictor of AML clinical relapse. Based on these results, cases with increase of WT1 levels after HSCT and without graft vs. host disease may be candidate to discontinuation of immunosuppression and/or DLI therapy.     

Application of Multivariate Tools in Pharmaceutical Product Development to Bridge Risk Assessment to Continuous Verification in a Quality by Design Environment

An important aspect of a quality by design approach to pharmaceutical product formulation and process development is continuous quality verification. This is an innovative way of validating the process where manufacturing performance is continuously monitored, evaluated and adjusted as necessary. For new drug products, the body of knowledge accumulated through the development cycle and formalised via risk assessment forms the natural basis of this activity. This paper shows how multivariate tools can be used as part of a continuous quality verification approach for a new drug product relying on the information that summarises the control strategy, i.e. the subset of critical variables selected via risk assessment and the related proven acceptable ranges determined during developmental studies.