Systemic and local expression of perforin in lymphocyte subsets in acute and chronic rheumatoid arthritis

OBJECTIVE: To investigate the role of the cytolytic action mediated by perforin in the course of rheumatoid arthritis (RA), we studied the immunophenotypic characteristics of lymphocytes containing perforin in peripheral blood (systemic level), in synovial fluid (SF), and in the synovial membrane (local level) in patients during the acute or chronic phase of RA. Cells from patients with osteoarthritis were used as controls. METHODS: Flow cytometry was used for simultaneous detection of intracellular (perforin) and cell surface antigens. Mean fluorescence intensity (MFI) was a measure of the mean perforin content per cell. Immunocytochemical staining was used to visualize perforin in the cytoplasmic compartment of cells. RESULTS: In acute RA highly significant changes in perforin expression were found in all compartments (peripheral blood, SF, and synovial membrane): (1) increase of percentage of total perforin positive cells; (2) increase of both subsets of cytolytic cells, T (CD8+P+) and NK (CD56+P+) cells; (3) increase in the frequency of perforin positive cells in CD8+ and CD56+ cell populations; and (4) the highest content of perforin/cell (MFI values) in all compartments, except in the synovial membrane. CONCLUSION: Perforin positive cells may participate in the acute phase of RA by maintaining and perpetuating inflammation and contributing to tissue destruction.     

Malaria prevalence and associated risk factors in Eritrea

A parasitological cross-sectional survey was undertaken from September 2000 through February 2001 to estimate the prevalence of malaria parasitemia in Eritrea. A total of 12,937 individuals from 176 villages were screened for both Plasmodium falciparum and Plasmodium vivax parasite species using the OptiMal Rapid Diagnostic Test. Malaria prevalence was generally low but highly focal and variable with the proportion of parasitemia at 2.2% (range: 0.4% to 6.5%). Despite no significant differences in age or sex-specific prevalence rates, 7% of households accounted for the positive cases and 90% of these were P. falciparum. Multivariate regression analyses revealed that mud walls were positively associated with malaria infection (OR [odds ratio] = 1.6 [95% CI: 1.2, 2.2], P < 0.008). For countries with low and seasonal malaria transmission, such information can help programs design improved strategic interventions.     

Melatonin stimulates inositol-1,4,5-trisphosphate and Ca2+ release from INS1 insulinoma cells

The effects of melatonin in mammalian cells are exerted via specific receptors or are related to its free radical scavenging activity. It has previously been reported that melatonin inhibits insulin secretion in the pancreatic islets of the rat and in rat insulinoma INS1 cells via Gi-protein-coupled MT1 receptors and the cyclic adenosine 3',5'-monophosphate pathway. However, the inositol-1,4,5-trisphosphate (IP3) pathway is involved in the insulin secretory response as well, and the melatonin signal may play a part in its regulation. This paper addresses the involvement of the second messengers IP3 and intracellular Ca2+ ([Ca2+]i) in the signalling cascade of melatonin in the rat insulinoma INS1 cell, a model for the pancreatic beta-cell. For this purpose melatonin at concentrations ranging from 1 to 100 nmol/L, carbachol and the nonselective melatonin receptor antagonist luzindole were used to stimulate INS1 cell batches, followed by an IP3-mass assay and Ca2+ imaging. Molecular biological studies relating to the mRNA of IP3 receptor (IP3R) subtypes and their relative abundance in INS1 cells showed expression of IP3R-1, IP3R-2 and IP3R-3 mRNA. In conclusion, we found that in rat insulinoma INS1 cells there is a dose-dependent stimulation of IP3 release by melatonin, which is accompanied by a likewise transient increase in [Ca2+]i concentrations. The melatonin effect observed mimics carbachol action. It can be abolished by 30 micromol/L luzindole and is sustained in Ca2+-free medium, suggesting a mechanism that includes the depletion of Ca2+ from intracellular stores.     

The role of mitochondrial targeting in arsenic trioxide-induced apoptosis in myeloid cell lines

Data regarding the role of mitochondria in arsenic trioxide (As2O3)-induced apoptosis are controversial. We investigated the contribution of caspases and mitochondrial depolarization to As2O3-induced apoptosis in the myeloid cell lines NB-4, HL-60 and U-937. Caspase inhibition reduced the amount of cells with As2O3 (20 micromol/l)-induced mitochondrial depolarization by about 50% in all cell lines. As2O3 also induced dose-dependent phosphatidylserine exposure in cells without depolarized mitochondria. We conclude that caspase activation is of similar importance in As2O3-induced apoptosis in myeloid cell lines as direct mitochondrial targeting and mitochondria are not necessary for caspase activation downstream of mitochondria.     

Serum carnitine levels and carnitine esters of patients after kidney transplantation: role of immunosuppression

Serum levels of carnitine and carnitine esters were measured in different groups of patients after cadaveric renal transplantation and compared with those of healthy subjects as well as azotemic and uremic patients. In all groups of patients serum levels of total carnitine (TC), free carnitine (FC), short-chain acylcarnitine (SCC), and long-chain acylcarnitine (LCC) increased with reduction of kidney function. However, cyclosporin- and prednisone-treated transplant patients with impaired kidney function displayed significantly higher TC, FC, and SCC compared with transplant patients under immunosuppression with azathioprine and prednisone. This group of cyclosporin-treated patients showed also significantly elevated serum cholesterol suggesting that carnitine deficiency is not responsible for the observed abnormalities in lipid metabolism after renal transplantation. Urinary excretion of TC, FC, SCC, and LCC decreased with reduction of kidney function without differences between cyclosporin- and azathioprine-treated patients. Single dose L-carnitine administration (10 mg/kg body weight IV) resulted in significantly higher TC, FC, SCC, and LCC values of azotemic patients with and without immunosuppression than in healthy subjects. Acylation of the administered carnitine was comparable in healthy controls and azotemic patients. Increased values of short-chain and long-chain acylcarnitine, therefore, seem to depend on the excretion of the diseased kidney(s). Our data demonstrate abnormalities in carnitine metabolism in patients with impaired kidney function. These alterations are further influenced by immunosuppressive drugs.     

CD30: from basic research to cancer therapy

Immunologic Research - The FDA recently approved an agonistic anti-CD30 drug conjugate, Brentuximab vedotin, for the treatment for CD30-positive lymphomas. The potent clinical activity of...     

Human and Animal Isolates of Yersinia enterocolitica Show Significant Serotype-Specific Colonization and Host-Specific Immune Defense Properties

Yersinia enterocolitica is a human pathogen that is ubiquitous in livestock, especially pigs. The bacteria are able to colonize the intestinal tract of a variety of mammalian hosts, but the severity of induced gut-associated diseases (yersiniosis) differs significantly between hosts. To gain more information about the individual virulence determinants that contribute to colonization and induction of immune responses in different hosts, we analyzed and compared the interactions of different human- and animal-derived isolates of serotypes O:3, O:5,27, O:8, and O:9 with murine, porcine, and human intestinal cells and macrophages. The examined strains exhibited significant serotype-specific cell binding and entry characteristics, but adhesion and uptake into different host cells were not host specific and were independent of the source of the isolate. In contrast, survival and replication within macrophages and the induced proinflammatory response differed between murine, porcine, and human macrophages, suggesting a host-specific immune response. In fact, similar levels of the proinflammatory cytokine macrophage inflammatory protein 2 (MIP-2) were secreted by murine bone marrow-derived macrophages with all tested isolates, but the equivalent interleukin-8 (IL-8) response of porcine bone marrow-derived macrophages was strongly serotype specific and considerably lower in O:3 than in O:8 strains. In addition, all tested Y. enterocolitica strains caused a considerably higher level of secretion of the anti-inflammatory cytokine IL-10 by porcine than by murine macrophages. This could contribute to limiting the severity of the infection (in particular of serotype O:3 strains) in pigs, which are the primary reservoir of Y. enterocolitica strains pathogenic to humans.     

Higher Glucocorticoid Secretion in the Physiological Range Is Associated With Lower Bone Strength at the Proximal Radius in Healthy Children: Importance of Protein Intake Adjustment

Whether higher production of glucocorticoids (GCs) within the physiological range may already be affecting bone status in healthy children is unknown. Because dietary protein intake affects both bone and GCs, we examined the association of urinary measures of glucocorticoid status and cortical bone in healthy non‐obese children, after particularly controlling for protein intake. Proximal forearm bone parameters were measured by peripheral quantitative computed tomography (pQCT). Subjects studied (n = 175, 87 males, aged 6 to 18 years) had two 24‐hour urine samples collected: the first sample at 1 year before bone measurement, and the second sample at the time of bone measurement. Major urinary GC metabolites were measured by mass spectrometry and summed to assess daily adrenal GC secretion (∑C21). Urinary free cortisol (UFF) and cortisone (UFE) were summed to assess potentially bioactive free GCs (UFF + UFE). After controlling for several covariates and especially urinary nitrogen (the biomarker of protein intake) cortisol secretion ∑C21 was inversely associated with all analyzed pQCT measures of bone quality. ∑C21 also predicted a higher endosteal and lower periosteal circumference, explaining both a smaller cortical area and (together with lower BMD) a lower strength‐strain‐index (SSI). UFF + UFE, UFE itself, and a urinary metabolite‐estimate of 11beta‐hydroxysteroid dehydrogenase type1 (11beta‐HSD1) activity showed corresponding reciprocal associations (p < 0.05) with BMD and bone mineral content, but not with SSI and bone geometry variables. In conclusion, higher GC levels, even within the physiological range, appear to exert negative influences on bone modeling and remodeling already during growth. Our physiological data also suggest a relevant role of cortisone as the direct source for intracrine‐generated cortisol by bone cell 11beta‐HSD1. © 2014 American Society for Bone and Mineral Research.     

The K+ channel openers diazoxide and NS1619 induce depolarization of mitochondria and have differential effects on cell Ca2+ in CD34+ cell line KG-1a

OBJECTIVE: Mitochondrial membrane potential (deltaPsim) and intracellular Ca2+ play a crucial role in growth and differentiation in hemopoiesis. Some potassium channel openers such as diazoxide have the capacity to elevate cytosolic Ca2+ and depolarize mitochondria in cardiomyocytes. To clarify if such substances have effects on hemopoietic cells we investigated the commonly used opener of the mitoK(ATP) channel, diazoxide, and the opener of BK channels, NS1619, for their potential to depolarize mitochondria, elevate cytosolic Ca2+, and induce apoptosis in the hemopoietic CD34+ cell line KG-1a. METHODS: Fluorescent probes were used to investigate deltaPsim, free Ca2+, and apoptosis (JC-1, fluo-3-AM and annexin V-FITC) by flow cytometry. To measure deltaPsim with JC-1 in glycoprotein P+ cells we used an improved dye loading technique with verapamil. RESULTS: NS1619 induced stronger dose-dependent mitochondrial depolarizations than diazoxide. Depolarization was independent from caspase activation and could also be induced when the driving force for K+ out of cells was near 0 mV. In Ca2+ free solutions NS1619 induced stronger Ca2+ elevations than diazoxide and elevated Ca2+ also after Ca2+ depletion of the endoplasmatic reticulum with caffeine. NS1619 did not enhance the Ca2+ elevation induced by ionophores (CCCP, valinomycin) that depolarize mitochondria. Both agents were weak inducers of apoptosis. CONCLUSION: Diazoxide has similar effects in CD34+ cells as described for muscle or nerve cells. In accordance to the single channel conductance of mitoK(ATP) and BK channels, NS1619 is a more potent inducer of mitochondrial depolarization than diazoxide. NS1619 releases Ca2+ from an intracellular pool that is insensitive to caffeine but depends strongly on deltaPsim.     

Nasal-continuous positive airway pressure reduces pulmonary morbidity and length of hospital stay following thoracoabdominal aortic surgery

STUDY OBJECTIVES: Patients who undergo surgical repair of thoracoabdominal aortic aneurysms have a high risk for the development of respiratory complications, which cause significant postoperative morbidity and prolong hospitalization, compared to patients who undergo other types of surgery. We studied whether prophylactic noninvasive application of nasal continuous positive airway pressure (nCPAP) administered via a facemask immediately after extubation may reduce pulmonary morbidity and shorten the length of hospitalization. DESIGN: Prospective randomized clinical trial. SETTING: Surgical ICU of a university hospital. PATIENTS: Fifty-six patients following elective prosthetic replacement of the thoracoabdominal aorta, of whom 6 patients were excluded because they had received prolonged mechanical ventilation. INTERVENTIONS: Following extubation in the ICU, nCPAP was applied for 12 to 24 h at an airway pressure of 10 cm H2O to patients in the study group (n = 25). Subjects in the control group (n = 25) received standard treatment including intermittent nCPAP (10 cm H2O for 10 min) every 4 h. MEASUREMENTS AND RESULTS: In the study group, nCPAP was applied for a mean (+/- SD) duration of 23 +/- 3 h at an airway pressure of 10 +/- 1 cm H2O, which improved pulmonary oxygen transfer without altering hemodynamics (ie, heart rate, mean arterial BP, and central venous pressure). The application of nCPAP was associated with fewer pulmonary complications (Pa(O2)/fraction of inspired oxygen [F(IO2)] <100, atelectasis, pneumonia, reintubation rate) compared to the control group (7 of 25 patients vs 24 of 25 subjects, respectively; p = 0.019). The mean duration of intensive care treatment tended to be shorter in the study group compared to the control group (8 +/- 1 vs 12 +/- 2 days, respectively; difference not significant), while the mean length of hospital stay was shorter with nCPAP therapy (22 +/- 2 vs 34 +/- 5 days, respectively; p = 0.048). CONCLUSIONS: The prophylactic application of nCPAP at airway pressures of 10 cm H2O significantly reduced pulmonary morbidity and length of hospital stay following the surgical repair of thoracoabdominal aortic aneurysms. Thus, it can be recommended as a standard treatment procedure for this patient group.