Production of "ectopic" vasoactive intestinal peptide-like and neurotensin-like immunoreactivity in human pheochromocytoma cell cultures

Neoplastic chromaffin cells from human pheochromocytomas can exhibit extensive spontaneous and nerve growth factor (NGF)-induced outgrowth of neurite-like processes in vitro, despite the absence of such processes in vivo. To determine whether acquisition of neuron-like features by human pheochromocytoma cells in culture is accompanied by functional alterations, process outgrowth, vasoactive intestinal peptide-like immunoreactivity ( VIPLI ), neurotensin-like immunoreactivity (NTLI), and catecholamine content were studied in freshly dissociated cells and in 21-day-old cultures from six human pheochromocytomas. All of the cultures produced VIPLI and exhibited spontaneous process outgrowth. NGF stimulated process outgrowth and enhanced production of VIPLI . Dexamethasone inhibited process outgrowth and tended to decrease production of VIPLI . NTLI was detected in cells from only one of the tumors, and its production appeared to be regulated comparably to that of VIPLI . Catecholamine content decreased markedly in all of the cultures and was not regulated in parallel with either VIPLI or NTLI. The findings suggest that human pheochromocytoma cultures may help to elucidate cellular and molecular mechanisms regulating ectopic and normal VIP production.     

Orthogonal fields: variations in dose vs. gap size for treatment of the central nervous system

Variations in dose at the junction at the lower end of two lateral skull portals and the upper end of a posterior spinal portal used for irradiation of the central nervous system (CNS) were studied using 60Co and 6 MV linear accelerator radiation. The relationship between dose and gap size was measured via film dosimetry. Small variations in gap size resulted in large variations in dose (+/- 40%) at the junction. These variations in dose were more pronounced for the 6 MV accelerator than for the 60Co, but the volume of high and low dose tended to be smaller with the 6 MV linear accelerator.     

Tuftelin, mutans streptococci, and dental caries susceptibility

The purpose of this study was to identify genetic factors that contribute to dental caries susceptibility, either alone or in combination with environmental factors. Dental examinations were performed and buccal swab samples collected from 3- to 5-year-old children with at least 4 surfaces of decay, or with no evidence of decay. SNP assays for each of 6 candidate genes were performed for all cases and controls. Chi-square analysis and regression analysis were used for the evaluation of individual gene effects, environmental effects, and gene-environment interactions. There were no significant associations between single candidate genes and caries susceptibility. Levels of S. mutans were positively and Lactobacilli were negatively associated with caries. Regression analysis revealed a significant interaction between tuftelin and S. mutans, with 26.8% of the variation in dmfs explained by the interaction. Future research will focus on the identification of these additional factors and the development of functional assays so that these interactions can be better understood.     

Biotech and Biomaterials Research to Reduce the Caries Epidemic

The goal of this workshop is to develop a consensus within the biomaterials/bioengineering community for a research agenda focused on creating technologies that will address the current dental caries pandemic. The workshop will bring together expertise from academia, industry, and the NIH institutes in the areas of oral biofilm microbiology and innovative biomaterials. The rationale for the workshop is that science and technology have not produced sufficient practical tools for public health practitioners and the private delivery system to address the pandemic in dental caries that exists for children and adults from families with low incomes and for numerous ethnic minority and racial groups. Moreover, it is unclear whether the barriers are remediable bioengineering and technical problems or fundamental science questions. Nevertheless, the obligation to address the gap between scientific research and practical application is especially relevant today. The U.S. and state governments bear the majority of the cost of trying to control this pandemic through Medicaid, the Public Health Service, Indian Health Service and other similar programs. These costs continue to escalate as continued applications of existing technology are unlikely to markedly reduce disparities. The mainstays of caries prevention, topical and systemic fluorides and pit and fissure sealants, are technologies developed in the 1950s and 1960s.     

Characteristics of thawed autologous umbilical cord blood

BACKGROUND: Autologous umbilical cord blood (AutoUCB) has historically been cryopreserved for potential use in hematopoietic transplantation. Increasingly, private AutoUCB banking is performed for therapies unavailable today. A Phase I trial using AutoUCB treatment for early pediatric Type 1 diabetes afforded us an opportunity to analyze characteristics of AutoUCBs. STUDY DESIGN AND METHODS: Twenty AutoUCBs from AABB‐accredited private cord blood banks (CBBs) were evaluated for collection, processing, cryopreservation, and thaw characteristics. Using a standardized thaw‐wash method, AutoUCBs were assessed for viable total nucleated cells (vTNCs), viable CD34+ (vCD34+), and colony‐forming unit–granulocyte‐macrophage counts. Postthaw %vTNC recoveries were compared against processing characteristics and analyzed according to processing method, cryopreservation volume, concentration, container, and length of storage. RESULTS: AutoUCB collection volumes (19.9‐170 mL), cryopreserved TNC counts (7.6 × 10⁷‐3.34 × 10⁹), %TNC processing recoveries (39%‐100%), postthaw %vTNC recoveries (58%‐100%), and %vCD34+ recoveries (26%‐96%) varied widely. Regarding cell dose requirements, only 11% of evaluable AutoUCBs achieved the minimum TNC count of at least 9.0 × 10⁸ to meet the National Cord Blood Inventory banking threshold, and only 50% met the minimum of 5.0 × 10⁸ TNC count for Food and Drug Administration cord blood licensure eligibility. %vTNC recoveries correlated with %vCD34+ recoveries (R = 0.7; p = 0.03). Length of storage, cryopreservation volume, concentration, and container type did not affect postthaw %vTNC recoveries. CBB processing method, however, was associated with %vTNC postprocessing recoveries, with unmanipulated and plasma‐depleted AutoUCBs having the highest postthaw %vTNC recovery, followed by RBC‐depleted and density gradient–separated AutoUCBs. CONCLUSION: The high variability and low counts found in AutoUCB banking suggest that further standardization of characterization, collection, and processing procedures is needed.     

乙型肝炎肝组织血管病变组织及免疫组织化学的研究

乙型肝炎(HB)已成为我国危害最大的社会公共卫生问题.近年来,我们在分析、研究国内外有关病毒性肝炎文献后选择了以HB患者肝组织活检观察为主的研究方法,从肝组织学随访中研究各型HB肝实质变性坏死及肝纤维组织增生的动态变化规律[1-8],采用组织化学(组化)及免疫组织化学(免疫组化)染色方法对肝组织内HBsAg,HBcAg表达[3],不同类型纤维组织增生情况,血清HBeAg与抗-HBe转换及透明质酸,色氨酸代谢变化[9-13],进行了深入研究.