High and low fluences of alpha-particles induce a G1 checkpoint in human diploid fibroblasts

The effects of exposure to high and very low fluence alpha-particles on the G1 checkpoint were investigated in human diploid fibroblasts irradiated and released from density-inhibited confluent cultures by the use of the cumulative labeling index method. Transient and permanent arrests in G1 occurred in fibroblast populations exposed to mean doses as low as 1 cGy, suggesting that nontraversed bystander cells may contribute to the low dose response. In cells exposed to high fluences, the G1 checkpoint is at least as extensive as in gamma-irradiated cells. In contrast to gamma-irradiated cells, neither repair of potentially lethal damage nor a reduction in the fraction of cells transiently or permanently arrested in G1 were observed in cells held in confluence for 6 h after alpha-particle irradiation. Studies with isogenic wild-type, p53-/-, and p21Waf1-/- mouse embryo fibroblasts exposed to either gamma or alpha-particle radiation revealed a total lack of G1 arrest in either p53-/- or p21waf1-/- cells, indicating that the G1 checkpoint in wild-type cells is p53-dependent and that p21Wf1 fully mediates the role of p53 in its induction. In contrast to human cells, mouse embryo fibroblasts do not undergo a permanent G1 arrest. Except under conditions favoring potentially lethal damage repair, a comparable expression pattern of p53, p21Waf1, and other cell cycle-regulated proteins (pRb, p34cdc2, and cyclin B1) was observed in alpha-particle or gamma-irradiated human fibroblasts.     

Infections in elderly persons. An altered clinical presentation.

The high prevalence, morbidity, and mortality of infectious diseases in the geriatric population mandates that clinicians caring for older patients become better acquainted and familiar with the special and unique characteristics and features of this common clinical problem. Only through such awareness and understanding will clinical outcomes, functional capacity, and quality of life be improved in the elderly population.     

Identification of a 35 kDa Glycoprotein from Entamoeba histolytica by Sera from Patients with Amoebic Liver Abscess and with Mouse Monoclonal Antibody

In this work, we explored the relevance of a 35 kDa glycoprotein (Gm) of the outer membrane from E. histolytica in the diagnosis of the amoebic liver abscess (ALA) through ELISA and immunoblotting. We were interested in defining the relevance of this antigen in the immune response in patients with amoebic liver abscess and in exploring whether the mouse monoclonal antibody against this 35 kDa glycoprotein recognises the same epitope. We found that 87% of ALA patients had raised antibody levels to Gm antigen, whereas none of the healthy control subjects presented this same increase We also found 90% sensitivity, 100% specificity, 100% positive predictive value, 90% negative predictive value, and 90% prevalence value for this Gm antigen Nonetheless, we did not find any statistically significant differences in the levels of immunoglobulins against Gm, although IgG showed a tendency to increase, probably because we are dealing with a secondary immune response. Using electroimmunotransfer blot assay, we found that sera from ALA patients recognise the 35 kDa Gm protein in the same way as it is recognised by the mouse monoclonal antibody, suggesting that is a relevant molecule for the diagnosis of amebiasis, and eventually could lead to its use as protection against the disease.     

The thoracoscope as diagnostic tool for solid mediastinal masses

Background: Despite the accuracy of percutaneous biopsy of mediastinal masses under CT scan or sonographic control, there is still a need for surgical biopsy because of difficult location or because of insufficiency of the percutaneous biopsy, especially for those tumors requiring an immunological classification. Methods: The thoracoscopic approach to mediastinal masses is an alternative to the usual surgical biopsies performed through thoracotomy, sternotomy, or anterior mediastinotomy. The procedure is performed under general anesthesia and one-lung ventilation. Results: In a series of 47 cases, a histological diagnosis was obtained in 44 cases (93.6%). There was one hemorrhagic complication requiring thoracotomy (2.1%). The mean postoperative duration of stay was 3.2 days. Conclusions: Thoracoscopy is the method of choice in case of failure or contraindication of percutaneous biopsy. There is still a role for mediastinoscopy in treating paratracheal lymph nodes.     

Pelvic neurilemmoma

A rare case of benign pelvic neurilemmoma with bladder infiltration and ureteral obstruction is presented. This neurally originated tumor may occur anywhere in the body, but involvement of the urinary tract is rare. Management depends upon location and other clinical findings, and in this case, since complete removal was impossible, urinary derivation was employed as a palliative treatment.     

Safety assessment of the conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in stable renal transplant recipients

The immunosuppressant mycophenolate mofetil (MMF; CellCept) has greatly improved transplant recipients' clinical outcomes, but its efficacy may be limited by dose adjustments due to adverse events (AEs). An enteric-coated formulation of mycophenolate sodium (EC-MPS; myfortic), designed to improve gastrointestinal tolerability is now available. This Latin-American, prospective, multicenter, open-label, 6-month trial assessed the safety and tolerability of converting renal transplant recipients from MMF to EC-MPS. In total, 237 renal transplant recipients (stable > or = 3 months' posttransplant) receiving MMF (< or =1000 mg b.i.d.) were enrolled. Adults (n = 218) were converted to EC-MPS 720 mg b.i.d. (equimolar to MMF 1000 mg b.i.d.) even if they were initially receiving <1000 mg MMF b.i.d. (ie, 47 adults received a higher than equimolar dose of EC-MPS). Children (n = 19) were converted to EC-MPS 450 or 432 mg/m2 b.i.d. Patients also received cyclosporine microemulsion (Neoral) and corticosteroids. There were three acute rejections and no graft failures. The incidence of AEs was 59.9% (in those receiving a higher than equimolar EC-MPS dose it was 57.4%). In all, 22% of patients had gastrointestinal AEs, 37% had infections, and 4.8% had hematological AEs. Only 24 patients (10%) had an AE-related dose reduction. Seven of these patients had received higher than equimolar doses of EC-MPS. Patients can be safely converted from different doses of MMF to a standard dose of EC-MPS. The requirement for EC-MPS dose reduction to manage AEs was relatively low. Use of EC-MPS is a valid alternative for renal transplant recipients receiving maintenance MMF treatment.     

Surgical anatomy of the maxillary nerve in the zygomatic region

Anatomic knowledge on the zygomatic fossa is of primary importance to improve the regional anesthetic technique of the maxillary nerve. Few reports in the literature have addressed the trajectory of the maxillary nerve and its branches in this region; thus, this study aimed at presenting information about the trajectory of these nerves. Thirty human half-heads of both genders were fixed in 10% formalin and demineralized in 5% nitric acid, and the maxillary nerve was dissected since its origin on the pterygopalatine fossa until penetration into the inferior orbital fissure. It was observed that the maxillary nerve sends one to three posterior superior alveolar branches and tuberal descendent branches, which supply the soft tissue structures of the region. The posterior superior alveolar nerves are inferiorly oriented near the maxillary tuberosity, where they penetrate the alveolar canals with the posterior superior alveolar artery and send small nerve branches that continue in an extraosseous trajectory. This study found that nearly 2/3 of the trajectory of the maxillary nerve is located in the zygomatic region, with a short segment (1/3) in the pterygopalatine fossa.