Autologous bone marrow transplantation in follicular non-Hodgkin's lymphoma before and after histologic transformation

Patients with disseminated follicular non-Hodgkin's lymphoma (NHL) are only occasionally cured with standard chemotherapy regimens. Although most of these tumors are initially responsive to chemotherapy, in 40% to 70% of patients the lymphoma will eventually transform to an NHL of higher grade malignancy and a poorer prognosis. We treated 18 patients having an original diagnosis of follicular NHL with high-dose therapy and autologous bone marrow transplantation. The lymphomas of 10 of the patients had already undergone histologic transformation and eight still had a follicular histologic pattern. The former group had been followed for a longer time from the diagnosis of NHL and had been more extensively treated with conventional chemotherapy regimens. All eight patients with follicular NHL at the time of transplantation are alive for 246+ to 1,804+ days and seven of the patients are in complete remission. In contrast, of the 10 patients in histologic transformation only 1 is alive and in CR. This reflects the inability of these patients to tolerate the high-dose chemotherapy and myelosuppression as well as resistance of their lymphoma to this therapy. This difference in survival between the two groups was highly significant (P = .002). We conclude that the outcome of patients with follicular NHL transplanted early before histologic transformation is better than for those who are transplanted later in the course of their illness. Because of the relapsing behavior of follicular NHL, a longer follow-up is necessary to prove any impact on the natural history of the disease.     

Mast cells cultured from the peripheral blood of normal donors and patients with mastocytosis originate from a CD34+/Fc epsilon RI- cell population

Mast cells may be cultured from human peripheral blood in the presence of recombinant human stem cell factor (rhSCF). The characteristics of the cells in peripheral blood that give rise to mast cells are unknown. Because mast cell precursors in human marrow are CD34+, human peripheral blood mononuclear cells from patients with mastocytosis and normal controls were sorted on the basis of CD34 expression and the positive and negative cell populations were cultured in rhSCF, recombinant human interleukin-3 (rhIL-3), or both for 6 weeks. Cell cultures were examined every 2 weeks for total and mast cell number and cell differential using Wright Giemsa and acid toluidine blue stains and antibodies to mast cell tryptase and chymase, cell-associated histamine, and expression of CD34, c-kit, Fc epsilon RI, and Fc gamma RII using flow cytometric analysis. The ultrastructural anatomy of mast cells was examined by electron microscopy. Peripheral blood CD34+ cells cultured in rhSCF with or without rhIL-3 gave rise to cell cultures consisting of greater than 80% mast cells by 6 weeks. CD34+ cells cultured in rhIL-3 alone did not give rise to mast cells, whereas rhIL- 3 plus rhSCF increased the final mast cell number eightfold when compared with cells cultured in rhSCF alone. Mast cells increased concomitantly with a decrease in large undifferentiated mononuclear cells. CD34- cells did not give rise to mast cells. Histamine content per cell at 6 weeks was approximately 5 pg. Electron microscopy of 4- week cultures showed immature mast cells containing predominantly tryptase-positive granules that were either homogeneous or contained lattice structures, partial scroll patterns, or central dense cores and mixtures of vesicles, fine granular material, and particles. The CD34+ population at day 0 expressed Kit (65%) and Fc gamma RII (95%), but not Fc epsilon RI, by fluorescence-activated cell sorter analysis. At 6 weeks, CD34+-derived mast cells exhibited Fc epsilon RI in addition to Kit and Fc gamma RII, and were negative for CD34 antigen. Patients with mastocytosis showed a higher number of mast cells per CD34+ cell cultured compared with normal controls. Thus, the mast cell precursor in human peripheral blood is CD34+/Fc epsilon RI- and gives rise to mast cells in the presence of rhSCF with or without rhIL-3, and the number of mast cells arising per CD34+ cell in culture is greater when the CD34+ cells are obtained from patients with mastocytosis compared with normal subjects.     

换液频率对骨髓间充质干细胞生物学特性的影响

目的:培养条件是影响骨髓间充质干细胞生物学特性的重要因素。实验考察换液频率对兔骨髓间充质干细胞增殖分化及代谢特性等的影响。方法:实验于2005-03/2005-06在华东理工大学生物反应器工程国家重点实验室完成。①实验材料:1月龄新西兰大白兔购自上海市淞江车墩实验动物良种场。实验过程中对动物处置符合动物伦理学标准。②实验方法:采用密度梯度离心法从兔股骨骨髓中分离得到骨髓间充质干细胞,体外培养扩增后,取生长良好的第3代细胞分别以24,48,72h时间间隔进行换液培养。③实验评估:观察细胞形态学变化,测定细胞生长曲线同时进行乳酸和氨代谢分析,并对几种条件下收获的细胞进行集落形成和成骨分化检测。结果:①每24h换液的细胞最早进入对数生长期,第5天达到增殖顶点,最大细胞数目可达3.44×105,分别是48h和72h换液频率的1.43倍和1.71倍。②每48h换液条件下收获的细胞具有最强的集落形成能力,明显高于每24h和每72h换液条件下收获的细胞。③3种换液频率条件下收获的细胞经成骨诱导后茜素红染色均为阳性,其中每48h换液的细胞胞外钙基质分泌最高。④3种换液频率条件下细胞的代谢曲线无明显差异,乳酸和氨均维持较低浓度,分别在5mmol/L和2mmol/L以下。结论:①换液频率对骨髓间充质干细胞的影响具有双向性。提高换液频率促进骨髓间充质干细胞的增殖,同时也加速了干细胞特性的丢失,导致集落形成能力和成骨分化能力下降。②普遍采用的三四天换液不能提供适合骨髓间充质干细胞生长同时利于干细胞特性维持的营养环境,提示可通过常规培养条件的优化使其有利于骨髓间充质干细胞执行对称的细胞分裂。     

特发性脊柱侧凸患者椎旁肌结蛋白和波形蛋白的特征表达

目的:研究表明,结蛋白和波形蛋白可反映肌肉损伤再生的情况,同时结蛋白可反应肌力的大小。比较特发性和先天性脊柱侧凸患者顶椎处凹凸两侧椎旁肌形态和结蛋白及波行蛋白的表达,探讨椎旁肌在特发性脊柱侧凸发生发展中的作用。方法:①选择2005-07/2006-11间南方医科大学南方医院脊柱骨病科收治的部分特发性脊柱侧凸患者12例,Cobb角平均73.8°;先天性脊柱侧凸患者5例,Cobb角平均36.0°;腰椎间盘突出症患者2例和胸腰椎管内占位性病变患者3例作为正常对照。所有患者年龄均在10～20岁。②对脊柱侧凸患者顶椎凹凸两侧及正常对照组患者椎旁肌进行活检,术前均签署知情同意书。③采用光镜和电镜下观察椎旁肌的形态改变;SP法分别对光镜切片的结蛋白和波行蛋白进行免疫组织化学染色,在光镜下观察蛋白表达;应用图像分析系统测量结蛋白免疫组织化学染色后反应椎旁肌蛋白表达强弱的吸光度(A)。结果:22例患者全部进入结果分析。①椎旁肌组织形态:特发性脊柱侧凸患者椎旁肌在光镜及电镜下均有病变,凹侧椎旁肌病变较重,凸侧椎旁肌相对正常。②结蛋白免疫组织化学的阳性表达:结蛋白在各组椎旁肌中均有不同程度的表达,组间比较差别显著(P<0.01)。特发性脊柱侧凸及先天性脊柱侧凸患者椎旁肌在顶椎凸侧比正常组结蛋白表达稍强(0.2727±0.0478,0.2768±0.0372,0.2429±0.0272,P<0.05),特发性脊柱侧凸及先天性脊柱侧凸患者椎旁肌在顶椎凹侧相对于正常组表达减弱(0.1898±0.0258,0.1869±0.0306,0.2429±0.0272,P<0.05)。③波行蛋白免疫组织化学的阳性表达:各组间椎旁肌肌纤维内均无波形蛋白表达。特发性脊柱侧凸与先天性脊柱侧凸患者同侧椎旁肌两组间在形态和结蛋白及波行蛋白表达无明显差别(P>0.05)。结论:特发性脊柱侧凸患者椎旁肌内波形蛋白表达均为阴性,提示椎旁肌不存在再生现象。与先天性脊柱侧凸类似,特发性脊柱侧凸患者椎旁肌结蛋白表达凸侧增强及凹侧减弱为继发性改变。     

From the Cover: Evidence that Pacific tuna mercury levels are driven by marine methylmercury production and anthropogenic inputs

Pacific Ocean tuna is among the most-consumed seafood products but contains relatively high levels of the neurotoxin methylmercury. Limited observations suggest tuna mercury levels vary in space and time, yet the drivers are not well understood. Here, we map mercury concentrations in skipjack tuna across the Pacific Ocean and build generalized additive models to quantify the anthropogenic, ecological, and biogeochemical drivers. Skipjack mercury levels display a fivefold spatial gradient, with maximum concentrations in the northwest near Asia, intermediate values in the east, and the lowest levels in the west, southwest, and central Pacific. Large spatial differences can be explained by the depth of the seawater methylmercury peak near low-oxygen zones, leading to enhanced tuna mercury concentrations in regions where oxygen depletion is shallow. Despite this natural biogeochemical control, the mercury hotspot in tuna caught near Asia is explained by elevated atmospheric mercury concentrations and/or mercury river inputs to the coastal shelf. While we cannot ignore the legacy mercury contribution from other regions to the Pacific Ocean (e.g., North America and Europe), our results suggest that recent anthropogenic mercury release, which is currently largest in Asia, contributes directly to present-day human mercury exposure.

Mercury (Hg) is a global pollutant that affects both ecosystems and human health. Mercury is emitted to the atmosphere by natural processes (e.g., volcanism) and anthropogenic activities (e.g., fossil fuel combustion and artisanal and small-scale gold mining) (1) mainly as gaseous elemental Hg⁰. Atmospheric Hg can be deposited or taken up at the ocean surface (2). Rivers deliver significant amounts of Hg to estuarine and coastal oceans, but only a small fraction of this Hg is transported to open ocean regions (3). In the ocean, a substantial fraction of inorganic Hg is naturally transformed to methylmercury (MeHg) in the subsurface waters (4, 5). The neurotoxic MeHg naturally bioaccumulates and biomagnifies in aquatic food webs, leading to elevated concentrations in higher-trophic-level organisms such as tunas. Humans are exposed to MeHg mainly by the consumption of marine fishes, and tunas in particular, with MeHg representing the major chemical form (>91%) of total Hg in tuna muscle (6–8). The United Nations Environmental Program Minamata Convention (131 parties in June 2021) aims to protect human health and the environment from anthropogenic Hg. Governments and policy makers must therefore balance economic, environmental, and health interests. Understanding the factors that drive MeHg concentrations in tunas, and how climate change interferes in the process is therefore critical to policy makers and, ultimately, to limiting human exposure to MeHg.In line with the spatial distribution of Hg emissions, observations show higher atmospheric Hg⁰ levels in the northern hemisphere compared to the southern hemisphere (9). Sediment and peat records of atmospheric Hg deposition also suggest a larger anthropogenic Hg enrichment in the northern hemisphere (10). Anthropogenic Hg emissions are thought to have tripled the concentrations of total Hg in the thermocline waters (100 to 1,000 m) of the global ocean relative to deeper older waters (11), yet still unclear is how these anthropogenic Hg inputs are converted into methylmercury in oceans. Subsurface MeHg concentrations are higher in the eastern Pacific Ocean, with coastal and upwelling areas exhibiting the highest proportion of MeHg relative to total Hg (4, 12).Methylmercury uptake and biomagnification associated with fish age (and length), feeding ecology, and habitat use are known factors influencing Hg bioaccumulation in tunas (8, 13–15). A recent global-scale study documenting the distribution of tuna Hg concentrations at 11 different locations found up to an eightfold difference among sites but did not identify the drivers of this variability (16). Another study conducted at high spatial resolution in the southwestern Pacific Ocean suggested that ocean physics, local ocean biogeochemistry, and tuna habitat play important roles in determining tuna Hg concentrations (8, 17). Meanwhile, temporal trends in tuna Hg show contrasting results between oceanic basins. Decreasing Hg concentrations were observed in Atlantic bluefin tuna (Thunnus thynnus) from the northern Atlantic Ocean between 1990 and 2000 (18). In the Pacific Ocean, stable Hg concentrations between 2001 and 2018 were observed in tropical tunas (i.e., yellowfin, Thunnus albacares; bigeye, Thunnus obesus; and skipjack, Katsuwonus pelamis) from the southwestern Pacific (15), while increasing Hg levels in yellowfin and bigeye tunas since 1970 were documented in the central north Pacific (CNPO) (19). These contrasting trends suggest that tuna Hg may be sensitive to spatiotemporal changes in anthropogenic Hg emissions and ocean uptake and/or regional variations in biogeochemical processes or foraging ecology that affect tuna exposure to MeHg. Studies of large spatial coverage are therefore needed to investigate the control and relative importance of atmospheric Hg sources, oceanic Hg methylation, and foraging ecology on tuna Hg concentrations.Here, we report the highest spatially resolved dataset of Hg concentrations of skipjack tuna, with records from six distinct areas of the Pacific Ocean (n = 661, from ∼45°N to 25°S, Fig. 1A). As the third most consumed marine fish species worldwide (20), it is a species of high commercial and human health importance. Although classified as highly migratory, this epipelagic and fast-growing tuna species shows relatively restricted movements and high site fidelity rates in the Pacific Ocean (21, 22) and thus should be able to reflect spatial MeHg patterns in surface water food webs. We applied generalized additive models (GAM) to 1) explore geographical patterns, including hemispheric differences, of tuna Hg concentrations and 2) disentangle the driving factors of tuna Hg spatial variability. In particular, we used atmospheric Hg⁰ model estimates, ecological tracers in tuna, biogeochemical estimates at the base of food webs, and oceanographic variables to explore the relative contribution of anthropogenic Hg emissions, ocean biogeochemistry, and tuna foraging ecology to observed tuna Hg concentrations.Open in a separate windowFig. 1.Skipjack tuna sample provenance and mercury concentrations. (A) Map of skipjack sampling locations, with the size of the circles proportional to the number of individuals collected. (B) Power-law relationship between log(observed Hg) and skipjack fork length. The relationship was fitted on samples from the SWPO and WCPO only, but Hg residuals were calculated for all samples (symbolized by the black arrows). Oceanic areas: NWPO, CNPO, NEPO, EPO, SWPO, and WCPO.     

Signaling pathways involved in adenosine triphosphate-induced endothelial cell barrier enhancement

Endothelial barrier dysfunction caused by inflammatory agonists is a frequent underlying cause of vascular leak and edema. Novel strategies to preserve barrier integrity could have profound clinical impact. Adenosine triphosphate (ATP) released from endothelial cells by shear stress and injury has been shown to protect the endothelial barrier in some settings. We have demonstrated that ATP and its nonhydrolyzed analogues enhanced barrier properties of cultured endothelial cell monolayers and caused remodeling of cell-cell junctions. Increases in cytosolic Ca2+ and Erk activation caused by ATP were irrelevant to barrier enhancement. Experiments using biochemical inhibitors or siRNA indicated that G proteins (specifically Galphaq and Galphai2), protein kinase A (PKA), and the PKA substrate vasodilator-stimulated phosphoprotein were involved in ATP-induced barrier enhancement. ATP treatment decreased phosphorylation of myosin light chain and specifically activated myosin-associated phosphatase. Depletion of Galphaq with siRNA prevented ATP-induced activation of myosin phosphatase. We conclude that the mechanisms of ATP-induced barrier enhancement are independent of intracellular Ca2+, but involve activation of myosin phosphatase via a novel G-protein-coupled mechanism and PKA.     

'Am I going to see the next morning?' A qualitative study of patients' perspectives of sleep in COPD.

AIM: To investigate patients' perspectives of sleep in COPD. METHOD: Patients with moderate to severe COPD underwent semi-structured interviews about their sleep experiences. Contextual questionnaire data were collected. RESULTS: Ten patients were studied. Six reported bad sleep, but all described some sleep problems. Nocturnal anxiety and fears of breathlessness and dying were common features; these impacted on existing sleep problems related to exacerbations, medications, and habitual behaviours that can disrupt sleep. Poor sleep was associated with poorer health status. Patients reported a lack of support from their GPs and few had received advice for sleep problems. CONCLUSION: Anxiety about breathlessness affects the sleep experience of patients with COPD, and sleep quality impacts on physical and emotional functioning. Education about behaviours that can disrupt sleep offers potential benefits to the patient. COPD patients' sleep issues are complex and should be addressed at the clinical consultation.     

Neuron-specific enolase in the Merkel cells of mammalian skin. The use of specific antibody as a simple and reliable histologic marker

Merkel cells are specialized skin receptor cells, characterized by their particular location in the epidermis and close association with nerve terminals. Although they can be distinguished ultrastructurally by their small, electron-dense secretory granules, there is no specific and reliable method for identifying them by light microscopy. Using antibodies to neuron-specific enolase (NSE), the authors have shown sparsely distributed groups of specifically immunostained cells and associated nerve terminals in the nose skin of cats and rats. These cells were easily distinguished from other epithelial cell types, including melanocytes and Langerhans cells and had all the morphologic features of Merkel cells and their so-called neurite complexes, including the characteristic cytoplasmic secretory granules (60 nm in diameter). NSE immunostaining is a simple and reliable method for the specific light-microscopic staining of Merkel cells and provides further evidence for NSE as a marker for the diffuse neuroendocrine system.     

Antimicrobial resistance surveillance systems: Are potential biases taken into account?

BACKGROUND:

The validity of surveillance systems has rarely been a topic of investigation.

OBJECTIVE:

To assess potential biases that may influence the validity of contemporary antimicrobial-resistant (AMR) pathogen surveillance systems.

METHODS:

In 2008, reports of laboratory-based AMR surveillance systems were identified by searching Medline. Surveillance systems were appraised for six different types of bias. Scores were assigned as ‘2’ (good), ‘1’ (fair) and ‘0’ (poor) for each bias.

RESULTS:

A total of 22 surveillance systems were included. All studies used appropriate denominator data and case definitions (score of 2). Most (n=18) studies adequately protected against case ascertainment bias (score = 2), with three studies and one study scoring 1 and 0, respectively. Only four studies were deemed to be free of significant sampling bias (score = 2), with 17 studies classified as fair, and one as poor. Eight studies had explicitly removed duplicates (score = 2). Seven studies removed duplicates, but lacked adequate definitions (score = 1). Seven studies did not report duplicate removal (score = 0). Eighteen of the studies were considered to have good laboratory methodology, three had some concerns (score = 1), and one was considered to be poor (score = 0).

CONCLUSION:

Contemporary AMR surveillance systems commonly have methodological limitations with respect to sampling and multiple counting and, to a lesser degree, case ascertainment and laboratory practices. The potential for bias should be considered in the interpretation of surveillance data.     

Absence of hepatitis B virus DNA detected by polymerase chain reaction in blood donors who are hepatitis B surface antigen negative and antibody to hepatitis B core antigen positive from a United States population with a low prevalence of hepatitis B serologic markers

A recent study in hepatitis B surface antigen (HBsAg)-negative, antibody to hepatitis B core antigen (anti-HBc)-positive blood donors from a population with a high prevalence of hepatitis B serologic markers showed the presence of hepatitis B virus DNA (HBV DNA) as detected by polymerase chain reaction (PCR) in 4 percent of these donors. A sensitive, nested PCR assay was used to assess the prevalence of HBV DNA in a population of HBsAg-negative, anti-HBc-positive blood donors from a United States population with a low prevalence of hepatitis B serologic markers. The lower limit for detection by the PCR assay was 10(-5) pg per mL of HBV DNA. There was a review of 26,492 consecutive blood donations in a 12-month period. During this time, only 1 unit (0.004%) was HBsAg positive. An additional 158 units (0.6%) were repeatably reactive for anti-HBc. These 158 HBsAg-negative, anti- HBc-positive units were given by 119 donors of blood for allogeneic and autologous use. HBV DNA was not detected by PCR in blood from 83 allogeneic blood donors (93 samples) or 36 autologous blood donors (65 samples). Anti-HBc testing is an inefficient means of screening for potential hepatitis B infectivity and is associated with low test specificity in populations with a low prevalence of hepatitis B serologic markers.