Secretory lysosome disorders in the immune synapse and other tissues

IntroductionHaemophagocytic syndrome (HS) is a common manifestation of several congenital disorders characterised by a disruption of lysosomal secretion, interrupting the cytolytic pathway and triggering a dysfunction in the immune synapse. In this situation, the recognition of certain extra-immunological manifestations may help in the diagnostic process.Patients and methodsWe describe the clinical and biological features present in two brothers with familial haemophagocytic lymphohistiocytosis type 3 (FHL-3), two patients with Griscelli syndrome type 2 (GS-2) and one patient with Chédiak-Higashi syndrome (CHS).ResultsMutational assays at UNC13D were carried out on two brothers after diagnosing an early onset HS in the first one, yielding a positive result in both cases with a consequent diagnosis of FHL-3. The diagnosis of GS-2 was supported by positive results of mutational Rab27A studies in one patient with HS and abnormal pigmentation, and in her cousin who was affected by a similar abnormal pigmentation. The diagnosis of CHS was established in one patient with HS, abnormal pigmentation and atypical granules on cytological examination of a bone marrow smear. Diagnosis was confirmed in this patient by the finding of a homozygous LYST mutation.ConclusionsWe point out the importance of recognising the presence of typical extra-immunological manifestations of certain congenital disorders of lysosome secretion in patients diagnosed with HS. The association of albinism and immunodeficiency has played a critical role in the recent identification of the molecular mechanism involved in these disorders.     

Description of a Bivalent Cannabinoid Ligand with Hypophagic Properties

A series of bivalent cannabinoid ligands is proposed. The synthesis of double amides based on the rimonabant structure separated by an alkyl chain and the evaluation of their affinities for cannabinoid receptors are reported. The data of 4d confirmed that a bivalent structure is a suitable scaffold for CB₁ cannabinoid receptor binding. The compound 4d was selected for in vitro and in vivo pharmacological evaluations. Moreover, intraperitoneal administration of 4d to food‐deprived rats resulted in a dose‐dependent inhibition of feeding that was maintained up to 240 min.     

Solitary gastric ulcer due to cytomegalovirus: a cause of acute digestive hemorrhage

A 29-year-old homosexual man, with acquired immune deficiency syndrome was admitted to the hospital for evaluation of severe and recurrent epigastric pain, and important weight loss of 3-5 month duration. An upper gastrointestinal GI hemorrhage required an endoscopic examination which demonstrated a larger ulcer of the gastric antrum interpreted as suspicious of malignancy. Gastric cytomegalovirus (CMV) inclusion bodies, indicating CMV infection, were detected in the biopsy tissue from the edge of the gastric ulcer.     

Factors associated with inadequate response to hepatitis B vaccination in health care personnel

BACKGROUND: The recombinant hepatitis B vaccine provides immunity in approximately 95% of all cases, but there is a certain percentage which responds insufficiently. The purpose of this work consists of assessing the factors which are linked to an inadequate immune response. METHODS: This is an observational, analytical study in which a retrospective follow-up is made of a group of subjects vaccinated to prevent against hepatitis B (HBV). The variables of interest of the health care personnel meeting the requirements to be included in this study in Health Care District No. 9 of the Autonomous Region of Valencia (No. 827) were gathered. Following vaccination, the titration of surface antibodies (antiHB's) was determined for checking the response, levels of over 10 m UI/ml being considered to provide protection. RESULTS: An adequate serum changeover was achieved in 94.4% of those vaccinated. The low-degree or zero response to the vaccine was significantly linked independently to variables such as male gender, age, the body mass index (BMI) and the habit of smoking. Drinking alcohol and the levels of GPT, although they did not react significantly with the response to the vaccine, were possibly misleading factors. CONCLUSION: The immunogenicity of this vaccine is satisfactory. It is important to quantify the levels of antiHB's, especially when factors predicting a poor response are involved. Therefore, it is possible to identify those which require a booster shot and those showing no response, hence avoiding situations involving a false sense of being protected against HBV.     

Secretion of thymidine kinase to increase the effectivity of suicide gene therapy results in the loss of enzymatic activity

Low efficiency of gene transfer is one of the major limitations of gene therapy. A solution to this problem may be transmission; by modification of the transgene, the gene product can be secreted and internalized by the surrounding cells. Cancer gene therapy using the herpes simplex thymidine kinase (HSV-TK) suicide gene is a promising treatment, and TK has been used in clinical trials with some success. However, this kind of therapy has limited efficacy due to the low level of gene transfer reached. A modified TK protein, capable of migrating from the producing cell to neighboring cells, would result in a greater proportion of cells affected by the treatment. As a first step towards transmission, we constructed a secretory form of HSV-TK by including the Igkappa leader peptide in the gene. An endoplasmatic reticulum export signal was added to the construct to further improve its secretion. Secretion and protein production in cancer cells, the enzymatic activity of the modified proteins and the ability of the modified TK to sensitize cancer cells to ganciclovir were tested. Addition of the Igkappa leader resulted in high levels of secretion of HSV-TK, with up to 70% of the total amount of protein secreted. Inclusion of an ER export signal did not further improve secretion. The enzyme activity of the secreted TK however, was decreased when compared to native TK. This study is the first to report on secretion of TK, and provides a first step in a novel strategy to improve the efficiency of cancer gene therapy. The loss of function in secreted TK however, may present a major hurdle in the development of a transmitted form of TK.     

Angiogenesis in neuroblastoma: relationship to survival and other prognostic factors in a cohort of neuroblastoma patients.

PURPOSE: To study angiogenesis in neuroblastoma, using morphometric and computerized image analysis, and correlate the results with survival and other prognostic factors. PATIENTS AND METHODS: Sixty-nine patients from the Spanish Cooperative Study for Neuroblastoma were studied. Tumoral angiogenesis was studied using an avidin-biotin immunoperoxidase technique with an anti-CD34 antibody. Vascular parameters (VPs) were analyzed by a computerized system. Statistical analysis was also performed. RESULTS: Sixty-six samples had adequate tumoral tissue, and their tumoral vessels were counted. Endothelial cells were more prominent in pure neuroblastomas than in maturing and more mature tumors. VPs showed no statistical difference between the groups of patients as defined by the levels of the other prognostic factors in neuroblastoma: age, stage, histopathology, TRK-A, P-glycoprotein expression, or MYCN copy number. In patients who relapsed, tumors did not show statistically significant difference in VPs when compared with tumors from patients who did not relapse. There was also no difference in VPs in tumors from living patients when compared with tumors from deceased patients. Overall survival was 75%, and event-free survival was 55% at 50 months. CONCLUSION: VPs could be adequately determined by a computerized system in neuroblastoma; however, VPs were not predictive of survival for our patients. In our patients, neither disseminated nor local relapses were influenced by the angiogenic characteristics of the tumors.