Rapid detection of Leishmania infantum infection in dogs: comparative study using an immunochromatographic dipstick test,enzyme-linked immunosorbent assay,and PCR

Current zoonotic visceral leishmaniasis (ZVL) control programs in Brazil include the culling of Leishmania infantum-infected reservoir dogs, a strategy that has failed to prevent a rise of canine and human ZVL cases over the past decade. One of the main reasons this strategy has failed is because of a long delay between sample collection, sample analysis, and control implementation. A rapid, sensitive, and specific diagnostic tool would be highly desirable, because it would allow control interventions to be implemented in situ. We compared an immunochromatographic dipstick test to enzyme-linked immunosorbent assay (ELISA) and PCR for detecting L. infantum infections in dogs from an area of ZVL endemicity in Brazil. The dipstick test was shown to have 61 to 75% specificity and 72 to 77% sensitivity, compared to 100% specificity for both ELISA and PCR and 71 to 88% and 51 to 64% sensitivity for ELISA and PCR, respectively. Of the field samples tested, 92 of 175 (53%), 65 of 175 (37%), and 47 of 175 (27%) were positive by dipstick, ELISA, and PCR, respectively. The positive and negative predictive values for the tested dipstick were 58 to 77% and 75%, respectively. Efforts should be made to develop a more specific dipstick test for diagnosis of leishmaniasis, because they may ultimately prove more cost-effective than currently used diagnostic tests when used in mass-screening surveys.     

Haploidentical Stem Cell Transplantation for Refractory/Relapsed Neuroblastoma

Pediatric patients with refractory or relapsed metastatic neuroblastoma (NBL) have a poor prognosis despite autologous stem cell transplantation (SCT). Allogeneic SCT from a haploidentical donor has a remarkable alloreactive effect in patients with leukemia; thus, we evaluated this approach in children with very high-risk NBL. We analyzed data from 2 prospective phase I/II trials. A total of 26 patients with refractory (n?=?5), metastatic relapsed (n?=?20), or locally relapsed MYCN-positive (n?=?1) NBL received a median of 17?×?10⁶/kg T/B cell-depleted CD34⁺ stem cells with 68?×?10³/kg residual T cells and 107?×?10⁶/kg natural killer cells. The conditioning regimen comprised melphalan, fludarabine, thiotepa, OKT3, and a short course of mycophenolate mofetil post-transplantation. Engraftment occurred in 96% of the patients. Event-free survival and overall survival at 5 years were 19% and 23%, respectively. No transplantation-related mortality was observed, and the single death was due to progression/subsequent relapse. The median duration of follow-up was 8.1 years. Patients in complete remission before SCT had a significantly better prognosis than those with residual tumor load (P?<?.01). All patients with progressive disease before SCT relapsed within 1 year. Grade II and grade III acute graft-versus-host disease (GVHD) occurred in 31% and 12% of the patients, respectively. Chronic limited and extensive GVHD occurred in 28% and 10%, respectively. Our data indicate that haploidentical SCT is a feasible treatment option that can induce long-term remission in some patients with NBL with tolerable side effects, and may enable the development of further post-transplantation therapeutic strategies based on the donor-derived immune system.     

Influence of a mutation in IFN-γ receptor 2 (IFNGR2) in human cells on the generation of Th17 cells in memory T cells

The T cell subsets involved in inflammatory reactions are mainly the IFN-γ secreting Th1 cells and IL17-producing Th17 cells. Although Th17 cells are primed in the thymus, there is evidence that Th17 cells can be generated from effector memory CD4⁺ T cells. Cytokines as IL-6, TGF-β, IL-21 and IL-23 involved in development of Th17 cells are well described. Here we analyzed the impact of a mutation in the IFN-γ receptor 2 (IFN-γR2) on the induction of Th17 cells. By isolation of T cells and monocytes of a patient with this mutation we could demonstrate an inhibitory role of IFN-γ signaling as IFN-γR2-deficient monocytes induce a higher percentage of IL-17⁺ cells from both healthy and IFN-γR2-deficient CD4⁺ T cells. This data confirm the interference of these two T helper subsets and points to a balance of Th1 and Th17 cells obtained by their own cytokine production and their interplay with APCs.     

Hyperalgesia and neural excitability following injuries to central and peripheral branches of axons and somata of dorsal root ganglion neurons

We examined thermal hyperalgesia, excitability of dorsal root ganglion (DRG) neurons, and antinociceptive effects of N-methyl-d-aspartate (NMDA) receptor antagonists in rats with injury to different regions of DRG neurons. The central or peripheral branches of axons of DRG neurons were injured by partial dorsal rhizotomy (PDR) and chronic constriction injury of sciatic nerve (CCI), respectively, or the somata injured by chronic compression of DRG (CCD). Thermal hyperalgesia was evidenced by significantly shortened latencies of foot withdrawal to radiant heat stimulation of the plantar surface. Intracellular recordings were obtained in vitro from L(4) and/or L(5) ganglia. There are four principle findings: 1) PDR as well as CCD and CCI induced thermal hyperalgesia; 2) PDR produced significantly less severe and shorter duration hyperalgesia than CCD and CCI; 3) intrathecal administration of NMDA receptor antagonists d-2-amino-5-phosphonovaleric acid (APV) and dizocilpine maleate (MK-801) inhibited thermal hyperalgesia in PDR, CCD, and CCI rats. Pretreatment of APV and MK-801 delayed the emergence of hyperalgesia for 48-72 h, while posttreatment inhibited hyperalgesia for 24-36 h; and 4) CCD and CCI increased excitability of DRG neurons as judged by the significantly lowered threshold currents and action potential voltage thresholds and increased incidence of repetitive discharges. However, PDR did not alter the excitability of DRG neurons. These findings indicate that injury to the dorsal root, compared with injury to the peripheral nerve or DRG somata has different effects on the development of hyperalgesia. These contributions involve different changes in DRG membrane excitability, but each involves pathways (presumably in the spinal cord) that depend on NMDA receptors.     

p75 Neurotrophin Receptor-Mediated Signaling Promotes Human Hair Follicle Regression (Catagen)

Nerve growth factor (NGF) and its apoptosis-promoting low-affinity receptor (p75NTR) regulate murine hair cycling. However, it is unknown whether human hair growth is also controlled through p75NTR, its high-affinity ligand pro-NGF, and/or the growth-promoting high-affinity NGF receptor tyrosine kinase A (TrkA). In microdissected human scalp anagen hair bulbs, mRNA for NGF, pro-NGF, p75NTR, and TrkA was transcribed. Immunohistomorphometry and in situ hybridization detected strong NGF and pro-NGF expression in terminally differentiating inner root sheath keratinocytes, whereas TrkA was co-expressed with p75NTR in basal and suprabasal outer root sheath keratinocytes. During spontaneous catagen development of organ-cultured human anagen hair follicles, p75NTR mRNA levels rose, and p75NTR and pro-NGF immunoreactivity increased dramatically in involuting compartments primarily devoid of TrkA expression. Here, TUNEL(+) apoptotic cells showed prominent p75NTR expression. Joint pro-NGF/NGF administration inhibited hair shaft elongation and accelerated catagen development in culture, which was antagonized by co-administration of p75NTR-blocking antibodies. In addition, mRNA and protein expression of transforming growth factor-beta2 increased early during spontaneous catagen development, and its neutralization blocked pro-NGF/NGF-dependent hair growth inhibition. Our findings suggest that pro-NGF/NGF interacts with transforming growth factor-beta2 and p75NTR to terminate anagen in human hair follicles, implying that p75NTR blockade may alleviate hair growth disorders characterized by excessive catagen development.     

Long-term elevations of dietary sodium produce parallel increases in the renal excretion of urodilatin and sodium

The effects of dietary sodium intake on the renal excretion of urodilatin and of sodium were examined in six healthy male subjects. The 24-day study period was divided into three phases of 8 days each. Subjects Ingested 2.8 mequiv sodium (kg body weight)^–1 day^–1 during the first phase, 5.6 mequiv (kg body weight)^–1 day^–1 during the second phase, and 8.4 mequiv (kg body weight)^–1 day^–1 during the third phase. The excretion of both sodium (P<0.002) and urodilatin (P<0.006) increased in response to the increasing dietary sodium, while urine flow did not change. Urinary urodilatin excretion correlated closely with renal sodium excretion (P<0.001). Serum aldosterone levels (P<0.01) as well as serum renin levels (P<0.05) significantly decreased with increasing sodium intake. Plasma [Arg]vasopressin levels increased significantly (P<0.05). Plasma atrial natriuretic factor and cGMP levels as well as urinary cGMP excretion rates were unaltered by the changes in sodium intake. We conclude from these results that the renal natriuretic peptide, urodilatin, but not the main cardiac member of the natriuretic peptide family may be involved in the regulation of day-to-day sodium balance.     

Investigating the prediction value of multiparametric magnetic resonance imaging at 3 T in response to neoadjuvant chemotherapy in breast cancer

Objective

To explore the predictive value of parameters derived from diffusion-weighted imaging (DWI) and contrast-enhanced (CE)-MRI at different time-points during neoadjuvant chemotherapy (NACT) in breast cancer.

Methods

Institutional review board approval and written, informed consent from 42 breast cancer patients were obtained. The patients were investigated before and at three different time-points during neoadjuvant chemotherapy (NACT) using tumour diameter and volume from CE-MRI and ADC values obtained from drawn 2D and segmented 3D regions of interest. Prediction of pathologic complete response (pCR) was evaluated using the area under the curve (AUC) of receiver operating characteristic analysis.

Results

There was no significant difference between pathologic complete response and non-pCR in baseline size measures (p?>?0.39). Diameter change was significantly different in pCR (p?<?0.02) before the mid-therapy point. The best predictor was lesion diameter change observed before mid-therapy (AUC?=?0.93). Segmented volume was not able to differentiate between pCR and non-pCR at any time-point. The ADC values from 3D-ROI were not significantly different from 2D data (p?=?0.06). The best AUC (0.79) for pCR prediction using DWI was median ADC measured before mid-therapy of NACT.

Conclusions

The results of this study should be considered in NACT monitoring planning, especially in MRI protocol designing and time point selection.

Key Points

? Mid-therapy diameter changes are the best predictors of pCR in neoadjuvant chemotherapy. ? Volumetric measures are not strictly superior in therapy monitoring to lesion diameter. ? Size measures perform as a better predictor than ADC values.

     

Cutaneous T cell lymphoma: characterization by monoclonal antibodies

Monoclonal antibodies to human T cells permit the characterization of the surface phenotype of cutaneous T cell lymphoma (CTCL). The majority of CTCL cells are reactive with OKT1 and OKT3 monoclonals, which identify peripheral T cells and mature thymocytes. The neoplastic cells also react with OKT4, which recognizes the inducer T cell subset; they are, however, unreactive with OKT5 monoclonal, which identifies cytotoxic/suppressor T cell subsets. These data are in agreement with previous functional studies demonstrating that CTCL is a neoplasm of inducer (helper) T cells.