Phagocytosis of liposome particles by rat splenic immature monocytes makes them transiently and highly immunosuppressive in ex vivo culture conditions

Liposomes reportedly accumulate in monophagocytic systems (MPSs), such as those of the spleen. Accumulation of considerable amounts of liposome in a MPS can affect immunologic response. While developing a liposomal oxygen carrier containing human hemoglobin vesicle (HbV), we identified its suppressive effect on the proliferation of rat splenic T cells. The aim of this study was to elucidate the mechanism underlying that phenomenon and its effect on both local and systemic immune response. For this study, we infused HbV intravenously at a volume of 20% of whole blood or empty liposomes into rats, removed their spleens, and evaluated T cell responses to concanavalin A (Con A) or keyhole limpet hemocyanin (KLH) by measuring the amount of [(3)H]thymidine incorporated into DNA. Cells that phagocytized liposomal particles were sorted using flow cytometry and analyzed. Serum anti-KLH antibody was measured after immunizing rats with KLH. Results showed that T cell proliferation in response to Con A or KLH was inhibited from 6 h to 3 days after the liposome injection. Direct cell-to-cell contact was necessary for the suppression. Both inducible nitric-oxide synthase and arginase inhibitors restored T cell proliferation to some degree. The suppression abated 7 days later. Cells that trapped vesicles were responsible for the suppression. Most expressed CD11b/c but lacked class II molecules. However, the primary antibody response to KLH was unaffected. We conclude that the phagocytosis of the large load of liposomal particles by rat CD11b/c+, class II immature monocytes temporarily renders them highly immunosuppressive, but the systemic immune response was unaffected.     

Effects of intra-ventrolateral periaqueductal grey palmitoylethanolamide on thermoceptive threshold and rostral ventromedial medulla cell activity

Palmitoylethanolamide (PEA), a peroxisome proliferator-activated receptor-α (PPAR-α) ligand, exerts antinociceptive and anti-inflammatory effects. PEA (3 and 6 nmol) was microinjected in the ventrolateral periaqueductal grey (VL PAG) of male rats and effects on nociceptive responses and ongoing and tail flick-related activities of rostral ventromedial medulla (RVM) ON and OFF cells were recorded. Intra-PAG microinjection of PEA reduced the ongoing activity of ON and OFF cells and produced an increase in the latency of the nociceptive reaction. These effects were prevented by a selective PPAR-α antagonist, GW6471 and by a large-conductance Ca(2+)-activated K(+) channel inhibitor, charybdotoxin. Cannabinoid 1 (CB(1)) receptor blockade by AM251 increased the PEA-induced effect both on the ongoing activity of the ON cell and on the latency to tail flick without affecting the effect of PEA on the OFF cell. Conversely, a transient receptor potential vanilloid type 1 (TRPV(1)) blocker, I-RTX, had no effect on the ON cell activity and tail flick latency, whereas it blocked the PEA-induced decrease in ongoing activity of the OFF cell. PEA decreased the burst and increased the latency of tail flick-evoked onset of ON cell activity in a manner antagonised by GW6471 and charybdotoxin. AM251 and I-RTX, instead, enhanced these latter effects. In conclusion, intra-VL PAG PEA induces antinociceptive effects associated with a decrease in RVM ON and OFF cell activities. PPAR-α receptors mediate, and CB(1) and TRPV(1) receptors antagonise, PEA-induced effects within the PAG-RVM circuitry.     

Population pharmacokinetic and exposure-response analysis of nilotinib in patients with newly diagnosed Ph+ chronic myeloid leukemia in chronic phase

Purpose

We investigated the population pharmacokinetics and exposure-response relationship of nilotinib in patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase.

Methods

Nilotinib was given at 300?mg or 400?mg twice daily. Serum concentration data (sparse and full pharmacokinetic profiles) were obtained from 542 patients over 12?months. A population pharmacokinetic analysis was performed using nonlinear mixed-effect modeling. Exposure-response relationships were explored graphically or using logistic regression models.

Results

Nilotinib concentrations were stable over 12?months. Patients in the 400?mg twice-daily arm had an 11.5% higher exposure than did those in the 300?mg twice-daily arm, and the relative bioavailability of nilotinib 400?mg twice daily was 0.84 times that of 300?mg twice daily. Patient demographics did not significantly affect nilotinib pharmacokinetics. The occurrence of all-grade total bilirubin elevation was significantly higher in patients with higher nilotinib exposure, and a positive correlation was also observed between nilotinib exposure and QTcF change on electrocardiograms from baseline. There was no significant relationship between nilotinib exposure and major molecular response at 12?months.

Conclusions

There is a less than proportional dose-exposure relationship between nilotinib 300?mg and 400?mg twice-daily doses. Blood level testing is unlikely to play an important role in the general management of patients with newly diagnosed CML treated with nilotinib.     

Asian sand dust enhances murine lung inflammation caused by Klebsiella pneumoniae

Inhaling concomitants from Asian sand dust (ASD) may result in exacerbation of pneumonia by the pathogen. The exacerbating effect of ASD on pneumonia induced by Klebsiella pneumoniae (KP) was investigated in ICR mice. The organic substances adsorbed onto ASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360 °C for 30 min. ICR mice were instilled intratracheally with ASD at doses of 0.05 mg or 0.2 mg/mouse four times at 2-week intervals (total dose of 0.2 mg or 0.8 mg/mouse) and were administrated with ASD in the presence or absence of KP at the last intratracheal instillation. Pathologically, ASD caused exacerbation of pneumonia by KP as shown by increased inflammatory cells within the bronchiolar and the alveolar compartments. ASD enhanced the neutrophil number dose dependently as well as the expression of cytokines (IL-1β, IL-6, IL-12, IFN-γ, TNF-α) and chemokines (KC, MCP-1, MIP-1α) related to KP in BALF. In an in vitro study using RAW264.7 cells, combined treatment of ASD and KP increased gene expression of IL-1β, IL-6, IFN-β, KC, MCP-1, and MIP-1α. The same treatment tended to increase the protein level of IL-1β, TNF-α and MCP-1 in a culture medium compared to each treatment alone. The combined treatment tended to increase the gene expression of Toll-like receptor 2 (TLR2), and NALP3, ASC and caspase-1 compared with KP alone. These results suggest that the exacerbation of pneumonia by ASD + KP was due to the enhanced production of pro-inflammatory mediators via activation of TLR2 and NALP3 inflammasome pathways in alveolar macrophages.     

Genetic studies in a cluster of mucopolysaccharidosis type VI patients in Northeast Brazil

Mucopolysaccharidosis type VI (MPS VI, Maroteaux-Lamy syndrome) is a lysosomal storage disease caused by deficiency of arylsulphatase B. The incidence of MPS VI is very low, usually less than 1 case for every 1,000,000 newborns. In Northeast Brazil we identified in the county of Monte Santo (52,360 inhabitants) thirteen patients with MPS VI. The aim of this work was to identify the mutation(s) present in these patients and analyze intragenic SNPs to define possible haplotypes. The 13 MPS VI patients were found to be homozygous for the p.H178L mutation. All patients have the same haplotype for the intragenic SNPs. Based on current data, the prevalence of MPS VI in this region is estimated as 1:5,000 newborns. These results, together with pedigree analysis, strongly suggest a founder effect accounting for the high frequency of p.H178L mutation in this area. This reinforces the need of a comprehensive community genetics program for this area.     

Histiocytic sarcoma of the parotid gland region

Histiocytic sarcoma (HS) is a malignant neoplasm showing the morphological and immunophenotypic features of mature histiocytes. Reported herein is a case of HS of the parotid gland region. A 53-year-old woman noticed a swelling of the right preauricular area. Preoperative fine needle aspiration cytology showed an admixture of pleomorphic atypical cells and mature lymphocytes. She underwent total parotidectomy. Grossly, the tumor was located at the parotid gland to subcutaneous tissue, and showed infiltrative growth with massive necrosis and hemorrhage. Microscopically, the tumor was composed of marked pleomorphic cells with eosinophilic cytoplasm. Bizarre multinuclear giant cells were scattered and intermingled. Tumor cells were positive for CD68 (KP-1 and PG-M1), CD163, S-100 protein, CD1a, CD4 and CD31, but negative for CD3, CD20, CD21, CD79a, DEC205 and langerin, immunohistochemically. Monoclonal proliferation of B cells was not confirmed on polymerase chain reaction for IgH. The patient had recurrent lesions in the pelvis and stomach 5 months after parotidectomy and died of the disease 10 months after the operation.     

Sleep abnormalities in untreated patients with mucopolysaccharidosis type VI

Mucopolysaccharidosis type VI (MPS VI) is a lysosomal storage disease that affects an enzyme responsible for the degradation of glycosaminoglycans (GAGs). Partially degraded GAGs accumulate in several tissues, such as the upper airways (UA), which leads to the development of obstructive sleep apnea (OSA). Our objective was to determine the prevalence of OSA in a group of untreated patients with MPS VI and the association of OSA with clinical and echocardiographic findings. Patients aged 4 years or older with a biochemical diagnosis of MPS VI were included. Data about clinical history, physical examination, Doppler echocardiogram, and overnight polysomnography (PSG) were collected. Our results showed that of the 28 participants, 14 were boys; mean age was 98.5 months, and mean age at MPS VI diagnosis was 48.4 months. Snoring, witnessed apnea, pectus carinatum, and macroglossia were the main clinical findings. PSG results showed that 23:27 patients (85.1%) had OSA which was mild in 4, moderate in 5, and severe in 14 patients. Echocardiograms showed evidence of pulmonary hypertension (PH) in 14 patients. Lower (P = 0.037) and nadir SpO(2) (P = 0.007) were positively associated with PH. Clinical signs suggestive of respiratory abnormalities during sleep were not significantly correlated with the results of PSG. We conclude that the prevalence of OSA in patients with MPS VI was high, and the level of desaturation was positively correlated with PH. Symptoms during sleep were not associated with PSG findings, which suggests that this population should undergo routine PSG as earlier as possible. This study provides baseline data to estimate the potential impact of specific treatments in the sleep abnormalities presented by patients with MPS VI.