Evaluation of the mutagenic and cytotoxic effects of mercurous chloride by the micronuclei technique in golden Syrian hamsters

The aims of this study were to evaluate the mutagenic and cytotoxic activity of mercurous chloride by the micronucleus technique in vivo on the bone marrow of golden Syrian hamsters after a single i.p. drug administration. Forty male golden Syrian hamsters were classified into eight groups: negative control, positive control and six groups treated with different doses of mercurous chloride (1.25, 2.5, 5, 10, 20 and 40 mg/kg). The negative control was injected with physiological saline i.p. and the positive control with cyclophosphamide at a dose of 80 mg/kg i.p. With respect to mutagenic effect, the average number of micronucleated polychromatic erythrocytes (MPE) in hamsters treated with different doses of mercurous chloride was not significant compared with the negative control. With respect to cytotoxic effect, the average polychromatic erythrocyte/red blood cell ratio showed a significant decrease when the doses were higher than the 2.5 mg/kg dose compared with the negative control. In conclusion, this preliminary study shows a cytotoxic effect but not a mutagenic effect of calomel in vivo at one time point (24 h).     

Bruton tyrosine kinase gene mutations in Argentina

The block in differentiation from pro-B to pre-B cells results in a selective defect in the humoral immune response characteristic of human X-linked agammaglobulinemia (XLA). Mutations of Bruton tyrosine kinase (BTK) gene have been identified as the cause of XLA. Mutation detection is the most reliable method for making a definitive diagnosis, except when clinical and laboratory findings are distinctive and coupled with history of X-linked inheritance. To provide a definitive diagnosis to 40 families incorporated in the Argentinian Primary Immunodeficiencies Registry we analysed the BTK gene by SSCP analysis as screening method for XLA, followed by direct sequencing. The molecular defect was localized in 45 patients from 34 unrelated families. From the 34 independent mutations identified, 16 were previously undescribed, 31 were unique mutations, 22 were exonic single nucleotide changes (16 missense and 6 nonsense) and four intronic mutations. Because five families had clinical, immunological and inheritance data sufficient for a definitive diagnosis, our study allowed 37 patients from 29 families previously categorized probable/ possible XLA, have now definitive diagnosis leading to appropriate genetic counseling.     

Development and activation of human dendritic cells in vivo in a xenograft model of human hematopoiesis

Dendritic cells (DCs) are derived from CD34+ progenitors and play a central role in the development of immune responses and in tolerance. Their therapeutic potential underscores the need for in vivo models that accurately recapitulate human DC development and function to provide a better understanding of DC biology in health and disease. Using nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice transplanted with human CD34+ cells as a model of human hematopoiesis, we examined DC ontogeny. Progenitors of both myeloid (m) and plasmacytoid (p) DCs were identified in the bone marrow of mice up to 24 weeks after transplant, indicating ongoing and sustained production of DCs after initial engraftment. To determine whether human DCs derived from transplanted stem cells were functional, their response to acute inflammation using lipopolysaccharide (LPS) was examined. Eighteen hours after LPS administration, a dramatic increase in the plasma levels of the human inflammatory cytokines interleukin (IL)-8, IL-10, tumor necrosis factor-alpha, and IL-12p70 was observed. Only mDCs and not pDCs responded in vivo to LPS by upregulating CD86 and CD83. In vivo activation of human mDCs resulted in a substantial increase in the ability of mDCs to induce the proliferation of naive human T cells. Taken together, these data indicate that human CD34+ cells seem to have differentiated appropriately within the NOD/SCID microenvironment into DCs that are developmentally, phenotypically, and functionally similar to the DC subsets found in humans.     

Nonmyeloablative stem cell transplantation is an effective therapy for refractory or relapsed hodgkin lymphoma: results of a spanish prospective cooperative protocol.

We report the results of reduced-intensity conditioning allogeneic stem cell transplantation (allo-RIC) in patients with advanced Hodgkin lymphoma (HL). Forty patients with relapsed or refractory HL were homogeneously treated with an RIC protocol (fludarabine 150 mg/m(2) intravenously plus melphalan 140 mg/m(2) intravenously) and cyclosporin A and methotrexate as graft-versus-host disease (GVHD) prophylaxis. Twenty-one patients (53%) had received >2 lines of chemotherapy, 23 patients (58%) had received radiotherapy, and 29 patients (73%) had experienced treatment failure with a previous autologous stem cell transplantation. Twenty patients (50%) were allografted in resistant relapse, and 38 patients received hematopoietic cells from an HLA-identical sibling. Five patients (12%) died from early transplant-related mortality (before day +100 after allo-RIC). One-year transplant-related mortality was 25%. Acute GVHD developed in 18 patients (45%). Chronic GVHD developed in 17 (45%) of the 31 evaluable patients. The response rate 3 months after the allo-RIC was 67% (21 [52%] complete remissions and 6 [15%] partial remissions). Eleven patients received donor lymphocyte infusions (DLIs) for disease relapse. The response rate after DLI was 54% (3 complete remissions and 3 partial remissions). Overall survival (OS) and progression-free survival (PFS) were 48% +/- 10% and 32% +/- 10% at 2 years, respectively. Refractoriness to chemotherapy was the only adverse prognostic factor for both OS (63% +/- 12% versus 35% +/- 13%; P = .05) and PFS (55% +/- 16% versus 10% +/- 9%; P = .006). For patients with failure of a prior autologous hematopoietic stem cell transplantation, results were especially good for those who experienced late relapses (>/=12 months: 2-year OS and PFS were 75% +/- 16% and 70% +/- 18%, respectively). These data suggest that allo-RIC is feasible in heavily pretreated HL patients and has an acceptable early transplant-related mortality. Results are better in patients allografted in sensitive disease. Both responses observed after the development of GVHD and DLI may suggest a graft-versus-HL effect. Allo-RIC has to be considered an effective therapeutic approach for patients who have had treatment failure with a previous autologous hematopoietic stem cell transplantation.     

Role of laparoscopy with ultrasound in the staging process of pancreatic and ampullary tumors

Computarized tomography allows proper identification and evaluation of stage in the majority patients with periampullary tumors. However, 30% of peritoneal metastases cannot be seen in image studies. The aim of the present study was to evaluate the role of laparoscopy with laparoscopic ultrasound in the staging process of pancreatic and ampullary tumor. Diagnostic laparoscopy was performed on 20 patients included in the study Mean age was 58.35 +/- 13.4 years. Twelve were males and eight females. In two patients, laparoscopy showed peritoneal metastases and ultrasound did not show extrapancreatic involvement. In five patients, there was vascular invasion without metastases. In three patients, both peritoneal metastases and vascular invasion were found, and in five there was neither vascular invasion nor metastasis. Laparoscopic findings were confirmed in a but one patient. In 14 of the 16 patients In whom peritoneal lavage was performed, microscopic exam showed a sufficient number of cells to make a diagnosis. We concluded that laparoscopy with ultrasound is useful in staging of patients with duodeno-bilio-pancreatic malignancies.     

Iron metabolism and fungal infections in patients with haematological malignancies.

AIM--To determine whether iron metabolism influences the incidence of systemic fungal infection in patients with haematological malignancies. METHODS--The study population comprised 74 patients who had undergone myeloablative chemotherapy. Systemic fungal infections were classified as confirmed (histological confirmation or characteristic septate hyphae) or possible (antibiotic resistant fever which resolved following administration of intravenous amphotericin B, together with either typical radiographic lesions or massive oropharyngeal candidiasis). Parameters of iron metabolism included serum iron concentrations, total iron binding capacity, serum transferrin, and ferritin concentrations and transferrin saturation values. RESULTS--Patients who developed a fungal infection had substantially increased transferrin saturation values and ferritin concentrations at diagnosis together with low serum transferrin and high serum iron concentrations. This profile was present in patients with a fungal infection regardless of the underlying haematological disorder. CONCLUSION--Increased transferrin saturation values and high ferritin concentrations may be additional risk factors for the development of systemic fungal infection in patients with haematological malignancies.     

Fludarabine-based conditioning secures engraftment of second hematopoietic stem cell allografts (HSCT) in the treatment of initial graft failure.

Graft failure is associated with a high mortality rate. To date, regimens invoked for second transplants have resulted in inconsistent engraftment with high transplant-related mortality (TRM). We here report 16 consecutive patients, aged 4-59 years, who received second HSCT (HSCT-2) at a median of 45 days following primary or secondary failure of an initial unmodified (N = 3) or T cell-depleted (TCD) (N = 13) HSCT (HSCT-1). HSCT-1 was administered after myeloablative total body irradiation (TBI)- or alkylator-based conditioning for acute leukemias (N = 7), MDS (N = 6), CML (N = 2), and Fanconi anemia (N = 1). All patients experienced 1 or more infectious complications between HSCT-1 and HSCT-2, and 10 patients had active infections at the time of HSCT-2. Cytoreduction regimens used for HSCT-2 included fludarabine (Flu) in combination with cyclophosphamide (CTX) (N = 9), or thiotepa (Thio) (N = 5). In addition, 1 patient received Flu alone and 1 patient Thio combined with CTX. Antithymocyte globulin (ATG) (N = 11) or Alemtuzumab (N = 3) was added pretransplant to prevent rejection. For HSCT-2, donors included HLA-matched (N = 3) or mismatched (N = 8) related, or matched (N = 2) or mismatched (N = 3) unrelated donors. The primary graft donor was used in 6 of 16 cases. The grafts administered were unmodified peripheral blood stem cell transplantation (PBSCT) (N = 5) or bone marrow transplantation (BMT) (N = 3), TCD PBSCT (N = 8). All patients achieved engraftment at a median of 12 days and evaluable patients achieved complete donor chimerism. Six patients are alive with a median follow-up of 49 months, including 4/9 conditioned with Flu/CTX. In this series, outcome was statistically superior for younger patients (相似文献   

Relative right versus left frontal EEG in neonates

Although infants have been noted to have greater relative right or left frontal EEG as early as the neonatal period, other ways in which these newborns differ have not been reported. In this study, 48 newborns were divided on the basis of greater relative right versus greater relative left frontal EEG to determine whether these groups differed in other ways at the neonatal period including behavior, physiology, and biochemistry. We also were interested in whether these EEG patterns were related to any prenatal maternal variables including mood states (depression, anxiety, anger) and biochemistry as well as fetal activity. The greater relative right frontal EEG newborns had mothers with lower prenatal and postnatal serotonin and higher postnatal cortisol levels. The mothers of the greater relative right frontal EEG newborns also had greater relative right frontal EEG activation and lower vagal tone. The greater relative right frontal EEG newborns themselves had elevated cortisol levels, showed a greater number of state changes during sleep/wake behavior observations, and performed less optimally on the Brazelton Neonatal Behavior Assessment (T. B. Brazelton, 1973) including the habituation, motor, range of state, excitability, and depressive symptoms scales. These data suggest that greater relative right frontal EEG newborns may be at greater risk for developmental problems than those with greater relative left frontal EEG activation. In addition, a discriminant function analysis correctly classified 67% of the newborns' EEGs by prenatal maternal variables, suggesting that these might be used to target pregnant women for prenatal intervention.     

ICAM-3, the third LFA-1 counterreceptor,is a co-stimulatory molecule for both resting and activated T lymphocytes

Optimal activation of human T cells mediated by ligation of CD3/T cell receptor (TcR) complex requires co-stimulatory signals. These can be provided by the adhesive interaction between receptor molecules on T cells and their counter-receptors on antigen-presenting cells. Soluble ICAM-3, anti-ICAM-3 and anti-CD3 mAb were utilized to address the role of the ICAM-3/LFA-1 pathway in TcR/CD3-dependent or -independent T cell activation. Immunoaffinity-purified ICAM-3 co-immobilized with suboptimal concentrations of anti-CD3 monoclonal antibody (mAb) stimulated T lymphocytes as monitored by the expression of the lymphocyte activation antigens CD25 and CD69. The mechanism underlaying this activation appear to involve the interaction of ICAM-3 with a β2 integrin, likely to be LFA-1, since mAb to the CD18 chain completely inhibited T cell activation. Similar experiments demonstrated that anti-ICAM-3 mAb were able to co-stimulate both resting (cord blood) and activated (T cell clones) T lymphocytes. On the contrary, anti-ICAM-1 mAb were only co-stimulatory for CD25 expression on activated but not on resting T cells. In addition, we have found that some γδ T cell clones bearing the Vδ1 segment were activated by direct mAb engagement of ICAM-3 in the absence of TcR/CD3 occupancy. Furthermore, immobilized anti-ICAM-3 mAb also induced development of dentritic processes. In conclusion, our data suggest that ICAM-3 on the surface of both T cells and antigen-presenting cells plays an essential role in the initiation of the immune response.     

Laminar distribution and morphology of NADPH-diaphorase containing neurons in the superior colliculus and underlying periaqueductal gray of the rat

Summary We have studied the laminar distribution of reduced nicotinamide dinucleotide phosphate diaphorase (NADPH-d) activity and the morphology of positive neurons in the superior colliculus (SC) and the underlying periaqueductal gray (PAG) of the rat. The morphology of NADPH-d-positive neurons has been compared to that of Golgi-impregnated cells. The highest activity occurs in the stratum zonale and stratum griseum superficiale, contrasting with the pale neuropil in the stratum opticum, where only a few positive neurons are found. In the stratum griseum intermedium positive neurons are grouped in patches separated by narrow, NADPH-d-negative bands. In the deeper layers, the neuropil is NADPH-d-negative, and few neurons show enzymatic activity. In contrast, numerous neurons in the dorsolateral part of the PAG are intensely positive. They are continuous with the positive neurons in the stratum album profundum, with no clear border between the two centers. In both SC and PAG, only small and medium sized neurons are NADPH-d-positive. In comparison with Golgi material, all types of small neurons in the superficial layers show NADPH-d activity; NADPH-d histochemistry, however, does not visualize the characteristic dendritic appendages of these neurons. The large neurons of the SC and PAG, probably representing the long-projecting neurons of these centers, do not contain the enzyme.