Lymphocytes

The rete testis in the domestic fowl (Gallus gallus domesticus), Japanese quail (Coturnix coturnix japonica), guinea-fowl (Numida meleagris galeata) and drake (Anas platyrhynchos) was studied histologically and with both the scanning and transmission electron microscopes. All the birds have rete epithelial cells varying between squamous and high cuboidal. A cilium-like structure projects from the luminal portion of most cells into the rete lumen, and the outline of the cells varies from polygonal to elongate. Sparse, stubby microvilli were concentrated on the cell borders. Ultrastructural features suggest only moderate secretory and absorptive activities in the cells. The rete testis of birds is amply supplied with blood as well as lymphatic vessels and nerves. Intraepithelial lymphocytes form part of the rete epithelium, and macrophages are present in large numbers in the rete lumen of the domestic fowl and drake and, to a lesser degree, also in the rete epithelium of the drake.

The purpose of this investigation was to evaluate the extent to which obesity and/or hypertension may modify the response of rats' periodontium to chronic gingival irritation. Forty-four normal, spontaneously hypertensive, obese, and obese-hypertensive rats were used. Histopathologic evaluation of the periodontal structure showed both hyperplasia and hypertrophy of the walls of blood vessels supplying the periodontium in the hypertensive and obese-hypertensive animals. The results also indicated that obesity significantly contributed to e severity of periodontal disease. Hypertension alone was not a significant factor. The obese-hypertensive rats showed the most severe periodontal response to local irritation.

The potential cytogenetic damage in offset printing workers was evaluated using sister chromatid exchanges (SCEs), chromosome aberrations (CAs) and micronuclei (MN) as biomarkers in peripheral lymphocytes of 26 volunteers (14 workers, 12 controls). The CA, SCE and MN frequency of offset printing workers was significantly higher than in their controls. The replication index (RI) was not affected while the mitotic index (MI) was affected most in the workers. It can be concluded from this study that chronic occupational exposure to printing dyes and thinner may lead to a slightly increased risk of genetic damage among offset printing workers. Copyright © 2005 John Wiley & Sons, Ltd.

... The role of major histocompatibility complex class I antigens in tumorigenesis: future applications in cancer therapy. Auteur(s) / Author(s). NAPOLITANO L. (1) ; VOGEL J. ; JAY G. ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s). ... Tumor. ; Antígeno histocompatibilidad clase ...

Store-operated calcium entry (SOCE) is the predominant Ca2+ entry mechanism in nonexcitable cells and controls a variety of physiological and pathological processes. Although significant progress has been made in identifying the components required for SOCE, the molecular mechanisms underlying it are elusive. The present study provides evidence for a direct involvement of kinase suppressor of Ras 2 (KSR2) in SOCE. Using lymphocytes and fibroblasts from ksr2−/− mice and shKSR2-depleted cells, we find that KSR2 is critical for the elevation of cytosolic Ca2+ concentration. Specifically, our results show that although it is dispensable for Ca2+-store depletion, KSR2 is required for optimal calcium entry. We observe that KSR2 deficiency affects stromal interaction molecule 1 (STIM1)/ORAI1 puncta formation, which is correlated with cytoskeleton disorganization. Of interest, we find that KSR2-associated calcineurin is crucial for SOCE. Blocking calcineurin activity impairs STIM1/ORAI1 pun...

Cortisol inhibition of phytohemagglutinin (PHA)-induced lymphocyte activation was studied in vitro in peripheral blood mononuclear cells (PBMC) of patients with pathologies of the hypothalamic-pituitary-adrenocortical (HPA) system (n = 18) as well as in students under and out of academic stress. In patients with HPA pathologies, cortisol-induced inhibition of lymphocyte interleukin-2 (IL-2) secretion in vitro positively correlated (p < .005) with IL-2 synthesis, such that lymphocytes secreting less IL-2 were less cortisol sensitive. Similarly, in stressed students there was a positive correlation (p < .02) between lymphocyte DNA synthesis and cortisol inhibition in vitro. Academic stress also resulted in a decrease (p < .01) of lymphocyte cortisol sensitivity. The same tendency was observed in patients with Cushing's syndrome when compared with hypocortisolemic patients. Normal controls whose lymphocytes were glucocorticoid resistant showed higher lymphocyte activation ...

Treatment of mice with hydroxyurea to selectively kill all cycling cells has been used to study population dynamics and life expectancy of “natural” immunoglobulin-secreting cells in the bone marrow and spleen of nonimmunized animals. The results show that 50 to 90% of those cells are eliminated 2 to 3 days after one cycle of hydroxyurea administration, demonstrating their recent origin from cycling precursors. Using a protocol of long-term hydroxyurea treatment which abrogates cell production from the cycling precursors compartments, it was shown that “natural” immunoglobulin-secreting cells have a very short half renewal time, in the range of 15–60 h.

Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, TCAR, Riboxamide, NSC 286193) is a novel C-nucleoside with antitumor activity against several murine tumor models, including Lewis lung carcinoma. The mechanism whereby this compound exerts its antineoplastic effects is most likely related to a state of guanine nucleotide depletion whereby the anabolite, thiazole-4-carboxamide adenine dinucleotide, potently inhibits inosine-5'-monophosphate dehydrogenase. This Phase I study was designed to determine the maximally tolerated dose of Tiazofurin administered on a 5-day, every-28-day schedule. Tiazofurin levels were measured using a high-pressure liquid chromatography assay, and pharmacokinetic studies were performed in patients treated at each dose level. Nineteen patients received a total of 24 courses of the drug in doses ranging from 550 to 2200 mg/sq m. The dose-limiting toxicities were pleuropericarditis and a general illness best described as a "viral-like" sy...

Nuclear medicine workers are occupationally exposed to chronic ionizing radiation. It is known that ionizing radiation may have damaging effects on chromosomes. In the present study, we investigated the genotoxic effects of ionizing radiation on nuclear medicine workers. We used two different indicators of genotoxicity methods: sister chromatid exchange (SCE) and micronucleus (MN).

To evaluate in vivo collagen fiber behavior around two different dental implant necks placed in the mandibular bone of adult pigs. Scanning electron microscopic (SEM) and profilometric analyses were performed on both types of implant necks to evaluate the different surface morphology. Ten dental implants with machined titanium necks and 20 implants with zirconia necks were inserted into the mandibles of five adult pigs. Three months later, the animals were sacrificed; samples from the peri-implant mucosa were obtained and prepared for histologic analysis. Evaluation of collagen fiber orientation in the connective tissue surrounding the implant necks was performed by polarized light microscopy. Inflammation in the peri-implant soft tissues was also measured via the Gingival Index. Postoperative healing was uneventful; all implants, except for one of each type, were osseointegrated after 3 months. SEM and profilometric analyses confirmed that zirconia necks showed Ra, Rq, and Rz value...

We experienced the case of a 3-year-old male with a very rare combination of autoimmunity, including immune thrombocytopenia, recurrent Henoch-Schönlein purpura and intestinal Behçet disease. Exome sequencing of the patient's peripheral blood mononuclear cells identified a KRAS G13C mutation. Interestingly, the KRAS G13C mutation was observed in T and B lymphocytes, as well as natural killer cells, but not granulocytes. Our case was completely phenotypically different from RASopathies and did not meet the criteria for Ras-associated lymphoproliferative disease or juvenile myelomonocytic leukemia. This is the first reported case in which the KRAS mutation existed only in the lymphoid lineage. Based on the findings of our case and the current literature, it is clear that the RAS mutation in lymphoid cells is tightly linked with various autoimmune symptoms. The presence of the RAS mutation in lymphocytes should be reconsidered as a pathogenesis in cases of autoimmunity.

Although prednisone has been used to treat patients with idiopathic dilated cardiomyopathy, its efficacy has not been rigorously studied. We therefore randomly assigned 102 patients to either treatment with prednisone (60 mg per day) or a control group. At three months, improvement, defined prospectively as an increase in the ejection fraction of greater than or equal to 5 percentage points, was observed in 53 percent of the patients receiving prednisone and 27 percent of the controls (P = 0.005). The mean (+/- SE) ejection fraction increased 4.3 +/- 1.5 percentage points (from 17.9 +/- 1.0 to 22.2 +/- 1.6 percent) in the prednisone group, as compared with 2.1 +/- 0.8 percentage points (from 17.1 +/- 1.1 to 19.3 +/- 1.4 percent) in the control group (P = 0.054). All patients were categorized prospectively in two separately randomized subgroups. "Reactive" patients (n = 60) were those who had fibroblastic (n = 36) or lymphocytic (n = 2) infiltration or immunoglobulin deposition (n = 16) on endomyocardial biopsy, a positive gallium scan (n = 7), or an elevated erythrocyte sedimentation rate (n = 18). "Nonreactive" patients (n = 42) had none of these features. At three months, 67 percent of the reactive patients who received prednisone had improvement, as compared with 28 percent of the reactive controls (P = 0.004). Nonreactive patients did not improve significantly with prednisone (P = 0.51). After three months, reactive patients who received prednisone daily were switched to alternate-day therapy (60 mg every other day), and after six months the improvement seen earlier was no longer present. These data suggest that patients with idiopathic dilated cardiomyopathy may have some improvement when given a high dose of prednisone daily. However, the increases in the ejection fraction that we observed during prednisone treatment were small, their duration was limited, and the side effects were important. Overall, prednisone was judged to have only marginal clinical benefit, and should not be administered as standard therapy for dilated cardiomyopathy.