Cytokine-activated natural killer cells exert direct killing of hepatoma cells harboring hepatitis C virus replicons.

Hepatitis C virus (HCV)-specific impairments in host immunity have been described at multiple levels of the innate and adaptive response, which may lead to viral persistence in the majority of infections. Understanding of HCV-associated immune defects could lead to novel therapeutic advances. Natural killer (NK) cells, the major effector cells of the innate immune system, are functionally impaired in chronic HCV infection. It has been suggested that this phenotype is a result of virus-specific defects in antigen-presenting cells (APCs) that regulate NK cell activity, as normal NK function is restored when they are stimulated ex vivo. In this study, we used human NK cell cytotoxicity assays to evaluate the activation-induced effects of NK cells on the HCV replicon-containing hepatic cells. We found that cytokine-activated NK cells were capable of inducing an HCV-associated, perforin/granzyme-dependent lysis of human hepatoma cells and that this required direct cellular contact and was independent of MHC class I expression levels. In contrast, on removal of cytokine stimulation, NK cells failed to exert any direct cytolytic effect on replicon targets. These findings suggest an important underlying mechanism by which NK cells control HCV infection and, with appropriate understanding of HCV-associated immune defects, could lead to novel therapeutic advances.     

A novel hybridoma antibody (PASE/4LJ) to human prostatic acid phosphatase suitable for immunohistochemistry

A murine monoclonal antibody PASE/4LJ to prostatic acid phosphatase (PAP) was used to immunostain a wide variety of sections of benign and malignant tissues (654 blocks). Non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas, and scattered cells in prostatic and penile urethra were positive. Rat, dog and rabbit prostates were negative. Nine of 400 tumours of non-prostatic origin showed some positivity: 6/36 carcinoids, 1/9 islet cell tumours, 1/55 ovarian adenocarcinomas (serous) and one carcinosarcoma of the lung (epithelial portion). Positive staining was seen in islet cells in 4/5 specimens of normal pancreas, and in 4/9 blocks of normal pancreas surrounding a pancreatic tumour. Loops of Henle, maculae densae, and distal tubules in 10/10 fetal and 2/9 adult kidneys were also positive, with proximal tubules and collecting ducts negative. All other 159 blocks of non-neoplastic adult and fetal tissues were negative. The antibody was also affinity purified from ascitic fluid, and shown not to inhibit the enzyme activity of prostatic acid phosphatase.     

Lack of Major Effects on Mouse Brain Adenosine A1 Receptors of Oral Carbamazepine and Calcium Antagonists

Interaction with adenosine A1 receptors is a possible contributory mechanism to the anticonvulsant effects of carbamazepine (CBZ) and the dihydropyridine calcium antagonists. We measured the binding of [3H]cyclohexyladenosine to adenosine A1 receptors in mouse brain stem, cerebellum, and cortex after oral administration of nifedipine, nimodipine (NMD), and CBZ for 7 days and compared the results with binding in control mice. Equilibrium dissociation constant (Kd) and receptor numbers (Bmax) were calculated using Scatchard and saturation isotherm analyses. Mean Kds (SEM) in control brain stem, cerebellum, and cortex were 2.09 (0.31), 2.39 (0.2), and 3.12 (0.28) nM, respectively. Results of Bmax for the same areas were 188 (26), 280 (24), and 449 (54) fmol/mg protein. Nifedipine (p less than 0.005) and NMD (p less than 0.02) raised the Kd of A1 receptors only in the cerebellum, and CBZ increased cerebellar Bmax (p less than 0.05). These minor effects on A1 receptors in CF1 mice, when given in doses previously shown to have anticonvulsant properties in these animals, do not suggest that alteration in A1 receptor activity is an important mechanism for the anticonvulsant effects of these drugs.     

Slipping through the cracks: Sexual harassment, eating problems, and the problem of embodiment

The impact of sexual harassment on girls' and women's developing concept of their body and self has rarely been examined with the goal of expanding our understanding of weight and shape preoccupation. In this paper we examine how this pervasive form of violence contributes to young women's uneasiness about their developing bodies and results in a disruption of healthy female development that often gets played out in disordered patterns of eating and intense body monitoring.     

Age-linked prognostic categorization based on a new histologic grading system of neuroblastomas. A clinicopathologic study of 211 cases from the Pediatric Oncology Group.

Histologic sections (minimum of four sections per patient) from 211 patients with neuroblastoma were reviewed. The tumors were resected before therapy, which was standardized according to age and stage. Low mitotic rate (MR) (less than or equal to ten per ten high-power fields) and calcification emerged as the most significant prognostic features after statistical analysis by stepwise log-rank tests (P less than 0.0001 and P = 0.0065, respectively). Histologic Grades 1, 2, and 3 were defined on the basis of the presence of both, any one, or none of these two prognostic features, respectively (Grade 3 had absence of low MR, i.e., these tumors had high MR [greater than ten per ten high-power fields]). Statistically significant differences in survival were observed in the grades after adjusting for age and stage (P less than 0.001). The degree of differentiation, although significant by itself, was no longer significant after adjusting for the grades. Age groups (less than or equal to 1 versus greater than 1 year of age), which also emerged as an independent prognostic feature (P less than 0.001), were linked with the grades to define two risk groups as follows: (1) a low-risk (LR) group consisting of patients in both age groups with Grade 1 tumors and patients 1 year of age or younger with Grade 2 tumors and (2) a high-risk (HR) group consisting of patients older than 1 year of age with Grade 2 tumors and patients in both age groups with Grade 3 tumors. The difference in survival between LR (160 cases) and HR groups (51 cases) was statistically significant (P less than 0.001). Concordance between these LR and HR groups and the Shimada classification was observed in 84% of cases. The new histologic grading system has the following advantages: (1) use of familiar terminology and histologic features in the grading system and (2) relative ease of assessment because the degree of differentiation does not need to be determined. The grading system should be tested on a new data set with an appropriate histologic sample of similar size to confirm these results.