Manual and computer-aided space analysis: a comparative study

Separate injections of Haemophilus influenzae type b capsular polysaccharide-tetanus conjugate (PRP-T) vaccine and diphtheria-tetanus-pertussis (DTP) reconstitution of freeze-dried PRP-T vaccine with liquid DTP vaccine have been shown to be safe and immunogenic in infants. The present study was conducted to test the safety and immunogenicity of the liquid combination vaccine administered to young infants in the dual-chamber syringe. The study was a monocenter, open clinical trial of 3 month-old infants receiving PRP-T and DTP vaccines in the dual-chamber syringe reconstituted prior to injection. Healthy infants were immunized according to a 3, 4 and 5 months-of-age schedule. The vaccine was administered in a dual-chamber syringe, ready to use with two chambers. The proximal chamber contained freeze-dried PRP-T and the distal chamber contained liquid combination-vaccine DTP. The freeze-dried PRP-T vaccine was reconstituted with the liquid DTP vaccine in the same unidose dual-chamber syringe (0.5 mL) and was injected intramuscularly into the deltoid region. Blood sampling was performed prior to vaccination at 3 months of age and after the third vaccination at 6 months. The primary end-point was the serological response to PRP-T vaccine as expressed by the percentage of infants with an antibody titer greater than or equal to 1 microgram/mL. The reactogenicity was expressed as the percentage of reported local and systemic reactions. A total of 108 infants were included in the study and received the dual-chamber syringe vaccine. After the third injection, all the infants had a PRP antibody titer greater than or equal to 0.15 microgram/mL and 94.4% of infants had a PRP antibody titer greater than or equal to 1 microgram/mL; the pertussis agglutinin titers were over the threshold 40 and 80 in all infants and 98.1% were over the threshold 320. After the third injection, all the infants had diphtheria antibody titers greater than 0.1 IU/mL and 83.3% had titers greater than 1 IU/mL; all the infants had tetanus antibody titers greater than 0.1 IU/mL and 97.2% had results over 1 IU/mL. Thirty-seven infants (34.6%) had local reactions and 64.5% had systemic reactions. The dual-chamber syringe may reduce the cost of vaccine delivery, as well as the workload, and increase the vaccine acceptability and coverage rate of vaccines.     

Inhibition of monocyte leukotriene B4 production after aspirin desensitization

Aspirin-sensitive patients may be desensitized through a graded series of exposures to aspirin. We investigated the underlying mechanism of aspirin desensitization by measuring the release of leukotrienes B4 and C4 from calcium ionophore-stimulated peripheral blood monocytes. Compared with monocytes from normal volunteers (n = 5), monocytes from patients with aspirin-sensitive asthma (n = 10) released increased amounts of thromboxane B2 (1060 +/- 245 pg/ml vs 456 +/- 62 pg/ml), leukotriene B4 (861 +/- 139 pg/ml vs 341 +/- 44 pg/ml), and leukotriene C4 (147 +/- 31 pg/ml vs 56 +/- 6 pg/ml) at baseline. After aspirin desensitization, thromboxane B2 release was almost completely suppressed in both groups. Leukotriene B4 release was significantly decreased in the aspirin-sensitive group (484 +/- 85 pg/ml) but not in the normal subject group (466 +/- 55 pg/ml). The need for prednisone decreased significantly after patients were desensitized to aspirin (10.4 +/- 2.2 mg/day to 1.6 +/- 2.8 mg/day). These results demonstrate that desensitization to aspirin results in decreased monocyte leukotriene B4 release. On the basis of the bronchospastic and inflammatory potential of leukotrienes, the decrease in leukotriene release may contribute to the clinical improvement seen after aspirin desensitization.     

炼钢脱氧用铝线的无结晶器水平连续铸造

介绍了用废旧纯铝料，在特殊的固体燃料反射炉中连续熔化，水平连铸成（３．０～９．５）ｍｍ铝线坯的工艺流程及设备。经过试验，确定是一种生产炼钢脱氧用铝线的经济、有效的工艺方法。     

Extrarenal rhabdoid tumors of soft tissue: a clinicopathologic and immunohistochemical study of 18 cases

Rhabdoid tumor is a well-accepted clincopathologic entity among childhood renal neoplasms; similar tumors have been described in extrarenal locations. We present the clinicopathologic profile and the immunohistochemical features of a series of soft tissue rhabdoid tumors. Twenty-eight cases coded as extrarenal rhabdoid tumor (ERRT), RT, possible ERRT, and "large cell sarcoma" were retrieved from the Armed Forces Institute of Pathology soft tissue registry. The tumors were reclassified according to strict criteria by light microscopy, clinical information, immunohistochemistry, and, in some cases, electron microscopy. Soft tissue rhabdoid tumor (STRT) was defined as (1) a tumor composed of noncohesive single cells, clusters, or sheets of large tumor cells with abundant glassy eosinophilic cytoplasm, an eccentric vesicular nucleus, and an extremely large nucleolus; (2) positivity for vimentin and/or cytokeratin or other epithelial markers by immunostaining; and (3) exclusion of other tumor types with rhabdoid inclusions (melanoma, other sarcomas, carcinoma). Eighteen cases met our criteria for soft tissue rhabdoid tumors. The median patient age was 13 years (range, 6 months to 56 years). Ninety-four percent of STRT cases were positive for vimentin and 59% for pan-cytokeratin. Sixty-three percent and 60% were positive for CAM 5.2 and EMA, respectively. Seventy-nine percent stained for at least one epithelial marker; 76% stained for both vimentin and epithelial markers simultaneously. Forty-two percent stained for MSA, and 14% for CEA and SMA. CD99, synaptophysin, CD57 (Leu-7), NSE, and focal S100 protein were identified in 75%, 66%, 56%, 54%, and 31% of the STRT cases, respectively. All STRT cases examined were negative for HMB-45, chromogranin, BER-EP4, desmin, myoglobin, CD34, and GFAP. Follow-up examination in 61% of the STRT patients revealed that 64% of patients died of disease within a median follow-up interval of 19 months (range, 4 months to 5 years); 82% had metastases to lung, lymph nodes, or liver; 22% had local recurrences before metastasis; and 18% were alive without known disease status (median, 5.5 years). Soft tissue rhabdoid tumor is a highly aggressive sarcoma, predominantly of childhood. Besides having nearly consistent coexpression of vimentin and epithelial markers, STRTs show positivity for multiple neural/neuroectodermal markers that overlap with those of primitive neuroectodermal tumor.     

Isotope effects in the study of phosphoryl and sulfuryl transfer reactions

Phosphoryl and sulfuryl transfer reactions are essential biological processes. Multiple kinetic isotope effects have provided significant insights into the transition states of these reactions. The data are reviewed for the uncatalyzed reactions of phosphate and sulfate monoesters and for a number of enzymatic phosphoryl transfer reactions. Uncatalyzed phosphoryl and sulfuryl hydrolysis reactions are found to have very similar transition states. The phosphoryl transfer reaction catalyzed by protein-tyrosine phosphatases proceeds by a transition state very similar to that of the uncatalyzed reaction, but isotope effect data reveal an interesting interplay between the conserved arginine and enzyme dynamics involving general acid catalysis.     

v-raf suppresses apoptosis and promotes growth of interleukin-3-dependent myeloid cells

Interleukin-3 (IL-3) is required for the proliferation, survival and differentiation of myeloid progenitors. In the absence of IL-3, murine myeloid 32D.3 cells accumulate in the G1 phase of the cell cycle and subsequently undergo programmed cell death, or apoptosis. Here we demonstrate that enforced expression of the v-raf oncogene suppresses apoptosis of myeloid 32D.3 cells following the withdrawal of IL-3. Surprisingly, steady state levels of Bcl-2, an oncogene known to suppress apoptosis, were not dependent upon IL-3 in 32D.3 cells and its levels were not augmented in v-raf clones. This suggests that ability of v-raf to suppress apoptosis in the absence of ligand is either Bcl-2 independent or that v-raf kinase promotes Bcl-2 function. v-raf also promoted growth of these cells in the presence of IL-3. v-raf clones proliferated at an increased rate due to a shortened G1 phase and had decreased requirements for IL-3 for growth. Therefore, transformation of myeloid cells by v-raf involves signaling pathways which promote both cell cycle progression and cell survival.     

Time-averaged non-linear systems: steady-state analysis†

A non-linear system with time averaging can be regarded as one composed of a time varying system with a variable parameter. A non-linear operation, such as squaring is performed on the signal of the system and followed by low pass filtering. This filtered signal controls, in turn, the variable parameter. This paper considers the steady state analysis of time averaged non-linear systems. The analysis covers both passive (with input) and oscillatory (no input) systems, In the passive case it is shown that the response is similar to that of a passive system with the poles shifted. The harmonic content and distortion are computed for both the oscillatory and passive case. An evaluation of the frequency is carried out for the oscillatory case. An interesting result is that the significant filter characteristic is the attenuation at twice the frequency.     

Strict regulation of c-Raf kinase levels is required for early organogenesis of the vertebrate inner ear

Regulation of organogenesis involves a dynamic balance of the mechanisms regulating cell division, differentiation and death. Here we have investigated the pattern of expression of c-Raf kinase in the inner ear during early developmental stages and the consequences of manipulating c-Raf levels by misexpression of c-raf viral vectors in organotypic cultures of otic vesicle explants. We found that otic vesicles expressed c-Raf and its level remained constant during embryonic days 2 and 3 (E2-E3). c-Raf activity was increased in response to insulin like growth factor-I (IGF-I) and the activation by IGF-I of the c-Raf kinase pathway was a requirement to turn on cell proliferation in the otic vesicle. Overexpression of c-raf in E2.5 explants increased the proliferative response to low serum and IGF-I and blocked differentiation induced by retinoic acid. The increase in c-Raf levels also prevented nerve growth factor (NGF)-dependent induction of programmed cell death. Consistent with these results, the expression of a dominant negative c-Raf mutant potentiated retinoic acid action and decreased the rate of cell proliferation. We conclude that a strict control of c-Raf levels is essential for the co-ordination of the biological processes that operate simultaneously during early inner ear development.     

Induction of cell proliferation in quiescent NIH 3T3 cells by oncogenic c-Raf-1

The c-Raf-1 kinase is activated by different mitogenic stimuli and has been shown to be an important mediator of growth factor responses. Fusion of the catalytic domain of the c-Raf-1 kinase with the hormone binding domain of the estrogen receptor (deltaRaf-ER) provides a hormone-regulated form of oncogenic activated c-Raf-1. We have established NIH 3T3 cells stably expressing a c-Raf-1 deletion mutant-estrogen receptor fusion protein (c-Raf-1-BxB-ER) (N-BxB-ER cells). The transformed morphology of these cells is dependent on the presence of the estrogen antagonist 4-hydroxytamoxifen. Addition of 4-hydroxytamoxifen to N-BxB-ER cells arrested by density or serum starvation causes reentry of these cells into cell proliferation. Increases in the cell number are obvious by 24 h after activation of the oncogenic c-Raf-1 protein in confluent cells. The onset of proliferation in serum-starved cells is further delayed and takes about 48 h. In both cases, the proliferative response of the oncogenic c-Raf-1-induced cell proliferation is weaker than the one mediated by serum and does not lead to exponential growth. This is reflected in a markedly lower expression of the late-S- and G2/M-phase-specific cyclin B protein and a slightly lower expression of the cyclin A protein being induced at the G1/S transition. Oncogenic activation of c-Raf-1 induces the expression of the heparin binding epidermal growth factor. The Jnk1 kinase is putatively activated by the action of the autocrine growth factor. The kinetics of Jnk1 kinase activity is delayed and occurs by a time when we also detect DNA synthesis and the expression of the S-phase-specific cyclin A protein. This finding indicates that oncogenic activation of the c-Raf-1 protein can trigger the entry into the cell cycle without the action of the autocrine growth factor loop. The activation of the c-Raf-1-BxB-ER protein leads to an accumulation of high levels of cyclin D1 protein and a repression of the p27Kip1 cyclin-dependent kinase inhibitor under all culture conditions tested.