Experimental model systems for preclinical research on Waldenström macroglobulinemia

Waldenstr?m macroglobulinemia (WM) is an incurable low-grade lymphoplasmacytic lymphoma of mature IgM⁺ B-lymphocytes that warrants additional research to increase therapeutic options, enhance quality of life, and improve survival of patients with WM. Here we concluded a miniseries of short reviews on the diagnosis and treatment ^[1], natural history ^[2] and putative cell-of-origin of WM ^[3] with a brief survey of preclinical experimental model systems available for fundamental and translational research studies on this enigmatic neoplasm. The model systems comprise of: ① continuous tumor cell lines, three of which are well authenticated and demonstrated to be derived from the patient''s index tumor; ② human-in-mouse xenografts that rely on immunodeficient laboratory mice, adapted to carry small fragments of implanted human bone, to provide a suitable microenvironment for incoming lymphoma cells; and ③ genetically engineered mouse models (GEMMs) of neoplastic B-cell development, in which WM-like tumors arise spontaneously in the presence of fully functional innate and adaptive immune systems. Because none of the models developed thus far are perfect, additional efforts are required to achieve a better preclinical representation of disease characteristics of WM. To achieve that goal, the active involvement of basic and clinical research experts from China is called for, so novel drugs and immunotherapies for WM will reach clinics sooner, thereby ensuring the future of patients with WM will be brighter.     

IgM memory and Waldenström macroglobulinemia’s cell of origin

Waldenstr?m macroglobulinemia (WM) is a neoplasm of mature IgM-expressing B-lymphocytes that is characterized by the occurrence of a monoclonal IgM (mIgM) paraprotein in blood serum and the infiltration of hematopoietic bone marrow with malignant lymphoplasmacytic cells. WM remains incurable despite the development of new therapeutic options. Owing in large measure to having a low incidence, indolent clinical course and good long-term control with proper clinical management, WM has not been investigated as extensively as other B-lineage neoplasms. Major knowledge gaps in our understanding of the natural history of WM include the cell of origin. With that shortcoming in mind, here we discuss the significance of a specific gain-of-function mutation in the adapter protein, myeloid differentiation primary response 88 (MYD88), that occurs with near-complete penetrance in WM and suggests that tumor development is under strong selective pressure for elevated MYD88 signaling. This provides an intriguing link to IgM memory B-cells, which comprise two types of B-lymphocytes ( natural effector IgM⁺IgD⁺ cells and IgM^-only IgM⁺IgD^- cells ) that depend, in part, on MYD88 signaling and constitute intriguing candidates for WM’s cell of origin. We review the features and developmental history of IgM memory in greater depth and propose that WM may be derived from primitive innate-like B-cells ( marginal zone B-cells and B1 B-cells ) that feed the IgM memory compartment. We conclude with a model of MYD88-dependent tumor development in the mature B-cell lineage that considers two different ( convergent or divergent) oncogenesis pathways with respect to the cells of origin.     

Waldenström macroglobulinemia – immunophenotype and natural history

Despite encouraging progress in recent years, our knowledge of the natural history of Waldenstr?m macroglobulinemia (WM), a low-grade LPL (lymphoplasmacytic lymphoma) of mature IgM⁺ B-lymphocytes, remains superficial. This is particularly true of the etiology of WM (tumor causation and initiation) and the sequence of events that underlie the malignant transformation of precursor B cells (tumor progression). Here we briefly review the epidemiology of and genetic predisposition to WM and consider the role of autoimmunity and chronic inflammation in related tumor development. We discuss the immunophenotypic features of WM, including the immunological specificity of WM-associated IgM paraproteins. The proclivity of patients with WM to develop the rare immunoglobulin autoantibody syndromes mixed IgM-IgG cryoglobulinemia, chronic cold agglutinin disease, and IgM neuropathy will also be discussed. We conclude with a call for additional research to elucidate outstanding questions, such as the role of T cell-dependent vs. –independent immune responses in the pathophysiology of WM.     

Active EB virus infection in adults: a case series of 8 patients in a single institution and a review of related literature

Adult patients with chronic active EB virus infection (CAEBV) are few; however the disease runs an aggressive course. The goal of this study was to investigate the clinical characteristics, treatment as well as prognosis of CAEBV in adults. The clinical data of eight adult patients with CAEBV of were analyzed retrospectively. There were five male and three female patients with a median age of 47 (25-67) years old. The main clinical manifestations were fever, lymphadenopathy, splenomegaly, liver damage, abnormal coagulation and cytopenia. Peripheral blood EB virus DNA titers were significantly higher in all patients (4.14×10⁴—4.60×10⁵copy/mL). Most patients received treatment with glucocorticoids, cyclosporine and chemotherapy containing etoposide (as recommended in the HLH-2004 program or the scheme of ECOP). One patient progressed to aggressive natural killer (NK) cell leukemia in 5 months after diagnosis. Another patient without fever or cytopenia is still living now, after receiving hormone therapy. The remaining 6 cases died with a median survival of 15 months. In conclusion, CAEBV in adults is a rare but serious disease, often with multiple system damage, from which the prognosis is very poor. Further research is necessary to improve the understanding of this disease.     

Familial Alzheimer’s disease modelling using induced pluripotent stem cell technology

Alzheimer’s disease(AD)is a progressive neurodegenerative disease in which patients exhibit gradual loss of memory that impairs their ability to learn or carry out daily tasks.Diagnosis of AD is difficult,particularly in early stages of the disease,and largely consists of cognitive assessments,with only one in four patients being correctly diagnosed.Development of novel therapeutics for the treatment of AD has proved to be a lengthy,costly and relatively unproductive process with attrition rates of90%.As a result,there are no cures for AD and few treatment options available for patients.Therefore,there is a pressing need for drug discovery platforms that can accurately and reproducibly mimic the AD phenotype and be amenable to high content screening applications.Here,we discuss the use of induced pluripotent stem cells(iPSCs),which can be derived from adult cells,as a method of recapitulation of AD phenotype in vitro.We assess their potential use in high content screening assays and the barriers that exist to realising their full potential in predictive efficacy,toxicology and disease modelling.At present,a number of limitations need to be addressed before the use of iPSC technology can be fully realised in AD therapeutic applications.However,whilst the use of AD-derived iPSCs in drug discovery remains a fledgling field,it is one with immense potential that is likely to reach fruition within the next few years.     

Transplantation of collagen scaffold with autologous bone marrow mononuclear cells promotes functional endometrium reconstruction via downregulating ΔNp63 expression in Asherman's syndrome

Asherman's syndrome(AS) is a common disease that presents endometrial regeneration disorder. However, little is known about its molecular features of this aregenerative endometrium in AS and how to reconstruct the functioning endometrium for the patients with AS. Here, we report that ΔNp63 is significantly upregulated in residual epithelial cells of the impaired endometrium in AS; the upregulated-ΔNp63 induces endometrial quiescence and alteration of stemness. Importantly, we demonstrate that engrafting high density of autologous bone marrow mononuclear cells(BMNCs) loaded in collagen scaffold onto the uterine lining of patients with AS downregulates ΔNp63 expression, reverses ΔNp63-induced pathological changes, normalizes the stemness alterations and restores endometrial regeneration. Finally, five patients achieved successful pregnancies and live births. Therefore, we conclude that ΔNp63 is a crucial therapeutic target for AS. This novel treatment significantly improves the outcome for the patients with severe AS.     

Effects of Ce3+, Cd2+, and Hg2+ on activities and secondary structure of trypsin

The different effects of Ce³⁺, Cd²⁺, and Hg²⁺ on the activities and secondary structure of trypsin were studied. The results showed that trypsin activity was increased substantially by Ce³⁺ in 0.5–5 μmol/L concentration, but the activity was decreased significantly by Cd²⁺ or Hg²⁺ in 0.5–5 μmol/L concentration. The ultraviolet-visible spectrum of trypsin with 4 μmol/L Ce³⁺ treatment was the same as that of the control, but the 232-nm characteristic peak of trypsin with 4 μmol/L Cd²⁺ or Hg²⁺ treatment was blue-shifted and the peak intensity weakened. The circular dichroism (CD) spectrum of trypsin with 4 μmol/L Ce³⁺ treatment was similar to that of the control. The secondary structure of trypsin did not change with Ce³⁺ treatment. However, the CD spectrum of trypsin with 4 μmol/L Cd²⁺ or Hg²⁺ treatment was different from that of the control and Ce³⁺ treatment. The secondary structure of trypsin with Cd²⁺ or Hg²⁺ treatment changed greatly; for example, the α-helix and β-sheet contents were reduced significantly, the β-turn was enhanced greatly, and the random coil contents increased or decreased.     

Detection of potentially myocardial infarction susceptible individuals in Indian population

Zinc (Zn) and copper (Cu) concentrations in hair and urine of patients diagnosed and hospitalized for myocardial infarction (MI patients) and in their descendants (MI descendants) were estimated and compared with their age-matched healthy volunteers with no family history of MI (control group and control descendants). The data revealed approximately twofold higher Zn and twofold lower Cu in the urine of the patients; Zn was lower and Cu was higher in the urine of MI descendants than those of the patients (p<0.001), but Zn in hair and urine was higher and Cu in hair was lower in MI descendants compared with their control counterparts (p<0.001). The data suggested that there was a consistent rise in Zn and fall in Cu reserves in the genetically predisposed subjects (MI descendants) prior to the manifestation of clinical symptoms. Based on this, the data were subjected to logistic regression and a model was obtained to predict the susceptibility to MI (LR-MI), having impact factors values as follows: constant (C), −3.342; impact factor of body mass index, −0.776; impact factor of hair Zn, −2.449; impact factor of urine Zn, +3.441; impact factor of hair Cu, −15.077; impact factor of urine Cu, −24.153. For the equation Y=e ^x (1+e ^x ), the value of x was obtained as follows: −3.342+[BMI (kg/m²) (−0.776)]+[Hair Zn (μmol/g) (−2.449)]+[Urine Zn (μmol/L) (3.441)]+[Hair Cu (μmol/g) (−15.077)]+[Urine Cu (μmol/L) (−24.153)]. On substituting the values of BMI, hair Zn, urine Zn, hair Cu, and urine Cu in x, the response variable Y as zero for healthy controls and 0.99 or 99.9% susceptibility in MI patients were obtained. In between these two extremes, the response variable ranged between 0 and 0.99 or 99.9% susceptibility to MI in their descendants. It is envisaged that the MI patients have an operational component of a genetic disorder of ionic imbalance at a young age that can be exploited in making a prediction of susceptibility to heart stroke in individuals much before its onset and diagnosis in asymptomatic patients, particularly in genetic and epidemiological studies of MI.     

Mini-review to analyse the phenotype, genotype, and alloantibody titre against Diego antigens in the Chinese population

Diego blood antigens are important antigens in Mongoloid people and native South Americans owing to the Dia positivity rate found in these populations. However, the prevalence of Di^a+ is different among native populations of America and China. Our study reviewed the genotype, phenotype, and alloantibody titre of Diego blood group antigens to explain the existence of the dosage effect for Diego antigens. The prevalence of Di^a+ varied from 2.26% to 10.43% in the Chinese population was lower than that observed in Native Americans living in USA, Brazil, and Venezuela. The Di(a+b-)/Di(a+b+) ratio in the Chinese was 0.0044~0.0268, which was also lower than that observed in native Americans at 0.0203–0.1628, indicating that the major allele was Di(a+b+) in Di^a+Chinese or Asians. We also collected Di(a+b-), Di(a+b+), and Di(a-b+) samples from Chinese samples to examine the agglutinin titres with anti-Di^a and anti-Di^b and the results supported the existence of the dosage effect for Diego antigens. The agglutinin titres of anti-Di^a in Di(a+b+) specimens were lower than those in Di(a+b-) specimens, and agglutinin titres of anti-Di^b in Di(a+b+) specimens were lower than those in Di(a-b+) specimens. Alloantibodies against Di^a and Di^b antigen are majorly responsible for haemolytic disease of the new-born and anti-Di^a reactions resulting in stillborn foetus and transfusion reactions, such as fever and rash,were also reported in the Chinese population.     

Silicon deprivation decreases collagen formation in wounds and bone,and ornithine transaminase enzyme activity in liver

We have shown that silicon (Si) deprivation decreases the collagen concentration in bone of 9-wk-old rats. Finding that Si deprivation also affects collagen at different stages in bone development, collagen-forming enzymes, or collagen deposition in other tissues would have implications that Si is important for both wound healing and bone formation. Therefore, 42 rats in experiment 1 and 24 rats in experiment 2 were fed a basal diet containing 2 or 2.6 μg Si/g, respectively, based on ground corn and casein, and supplemented with either 0 or 10 μg Si/g as sodium metasilicate. At 3 wk, the femur was removed from 18 of the 42 rats in experiment 1 for hydroxyproline analysis. A polyvinyl sponge was implanted beneath the skin of the upper back of each of the 24 remaining rats. Sixteen hours before termination and 2 wk after the sponge had been implanted, each rat was given an oral dose of ¹⁴C-proline (1.8 μCi/100 g body wt). The total amount of hydroxyproline was significantly lower in the tibia and sponges taken from Si-deficient animals than Si-supplemented rats. The disintegrations per minute of ¹⁴C-proline were significantly higher in sponge extracts from Si-deficient rats than Si-supplemented rats. Additional evidence of aberrations in proline metabolism with Si deprivation was that liver ornithine aminotransferase was significantly decreased in Si-deprived animals in experiment 2. Findings of an increased accumulation of ¹⁴C-proline and decreased total hydroxyproline in implanted sponges and decreased activity of a key enzyme in proline synthesis (liver ornithine aminotransferase) in Si-deprived animals indicates an aberration in the formation of collagen from proline in sites other than bone that is corrected by Si. This suggests that Si is a nutrient of concern in wound healing as well as bone formation. The U.S. Department of Agriculture, Agricultural Research Service, Northern Plains Area is an equal opportunity/affirmative action employer, and all agency services are available without discrimination. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.     

Studies of five microelement contents in human serum,hair, and fingernails correlated with aged hypertension and coronary heart disease

Context: Complementary alternative medicine therapies based on the use of cesium chloride preparations for the treatment of cancer and radiation poisoning, have generated therapeutic interest; but oral or intravenous administration of cesium chloride (CsCl) to cancer patients as an alternative mode of cancer therapy have not been approved by the U.S. Food and Drug Administration (FDA). Objective: Cesium (Cs) levels from human tissue were measured to determine exposure to an alternative medical treatment. Cesium levels are reported from two patients who were administered cesium chloride in conjunction with aloe vera as part of an alternative cancer treatment. Design: The samples were analyzed by graphite furnace atomic absorption spectrometry with Zeeman background correction. As a reference, Cs was also determined in brain, liver, kidney, and whole blood from control case materials retrieved from the National Tissue Repository of the Armed Forces Institute of Pathology. Results: High levels of cesium were found in brain, liver, kidney, bile, gastric content, and whole blood collected at autopsy as compared to reference levels. The administration of cesium chloride resulted in blood levels a factor of 1100 higher than normal. The highest Cs concentrations were found in the liver (1029 μg/g, dry wt), followed by the kidney (815 μg/g, dry wt) and brain (219 μg/g, dry wt). Conclusion: The high accumulation in the liver suggests that hepatotoxicity from Cs might be an initial presenting symptom in Cs-poisoning cases. This is the first report describing two cases with high Cs levels in human tissues. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, Department of Defense, or the Armed Forces Institute of Pathology.     

Molecular mechanism of therapeutic approaches for human gastric cancer stem cells

Gastric cancer(GC)is a primary cause of cancer-related mortality worldwide,and even after therapeutic gastrectomy,survival rates remain poor.The presence of gastric cancer stem cells(GCSCs)is thought to be the major reason for resistance to anticancer treatment(chemotherapy or radiotherapy),and for the development of tumor recurrence,epithelial–mesenchymal transition,and metastases.Additionally,GCSCs have the capacity for self-renewal,differentiation,and tumor initiation.They also synthesize antiapoptotic factors,demonstrate higher performance of drug efflux pumps,and display cell plasticity abilities.Moreover,the tumor microenvironment(TME;tumor niche)that surrounds GCSCs contains secreted growth factors and supports angiogenesis and is thus responsible for the maintenance of the growing tumor.However,the genesis of GCSCs is unclear and exploration of the source of GCSCs is essential.In this review,we provide up-todate information about GCSC-surface/intracellular markers and GCSC-mediated pathways and their role in tumor development.This information will support improved diagnosis,novel therapeutic approaches,and better prognosis using GCSC-targeting agents as a potentially effective treatment choice following surgical resection or in combination with chemotherapy and radiotherapy.To date,most anti-GCSC blockers when used alone have been reported as unsatisfactory anticancer agents.However,when used in combination with adjuvant therapy,treatment can improve.By providing insights into the molecular mechanisms of GCSCs associated with tumors in GC,the aim is to optimize anti-GCSCs molecular approaches for GC therapy in combination with chemotherapy,radiotherapy,or other adjuvant treatment.     

Expression of Pdx-1 in bone marrow mesenchymal stem cells promotes differentiation of islet-like cells in vitro

Bone marrow mesenchymal stem cells (BMSCs) have the ability of self-renewal and multi-directional differentiation. Recent reports showed that BMSCs could differentiate into endocrine cells of pancreas. However, the differentiation is not efficient enough to produce insulin-producing cells for the future therapeutic use. Pdx-1 is a crucial regulator for pancreatic development. Therefore we constructed a eukaryotic expression vector containing Pdx-1 to determine the effect of Pdx-1 expression on differentiation of BMSCs in vitro. The results showed that BMSCs could self-assemble to form functional pancreatic islet-like structures after differentiation in vitro. The proportion of insulin-producing cells differentiated from Pdx-1⁺BMSCs was 28.23%±2.56%, higher than that from BMSCs transfected with vacant vector and Pdx-1 ⁻ BMSCs (7.23%±1.56% and 4.08%±2.69% respectively) by flow cytometry. Immunocytochemical examination also testified the expression of multiple β-cells-specific genes such as insulin, glucagons, somatostatin in differentiated BMSCs. The results also revealed that the expressions of genes mentioned above in Pdx-1⁺BMSCs were higher than that in Pdx-1⁻BMSCs, which was confirmed by Western blotting analysis and RT-PCR. Glucose-induced insulin secretion from Pdx-1⁺BMSCs in 5mmol/L and 25mmol/L glocuse was (56.61±4.82) μU/mL and (115.29±2.56) μU/mL respectively, which were much higher than those from Pdx-1⁻BMSCs((25.53±6.49) μU/mL and (53.26±7.56) μU/mL respectively). Grafted animals were able to maintain their body weight and survive for relatively longer periods of time than hyperglycemic sham-grafted controls, which demonstrated an overall beneficial effect of the grafted cells on the health of the animals. These findings thus suggested that exogenous expression of Pdx-1 should provide a promising approach for efficiently producing islet-like cells from BMSCs for the future therapeutic use in diabetic patients.     

Recolonization of estuarine organisms: effects of microcosm size and pesticides

Two six-week laboratory experiments were conducted to evaluate effects of pesticides and microcosm size on benthic estuarine macroinvertebrate recolonization. Sediments fortified with the pesticides (fenvalerate: controls, 5 (low) and 50 μg g⁻¹ wet sediment (high); endosulfan: controls, 1 (low) and 10 μg g⁻¹ wet sediment (high)) were fine-grained, organically rich (approximately 3.5% organic carbon and 22% dry weight) material. Relative dominance of the four most abundant taxa in both experiments was consistent among treatments with few exceptions. The amphipod,Corophium acherusicum, dominated abundance in both experiments. In the fenvalerate experiment, large trays (400 cm²) contained significantly (p<0.05) more total number of taxa (TNT) than small microcosms (144 cm²) but tray size was not significantly related to total number of organisms (TNO). When size was adjusted to a common unit area, small trays contained significantly more TNO than large containers. Adjusted abundance of small trays was 2.5 times that of large containers; a ratio close to that of microcosm sizes (i.e., 2.8). This result suggests that larval supply may have been inadequate to ‘aturate’ the available sediment in large containers. Fenvalerate significantly reduced abundance in the high treatment compared to both controls and low treatment but low treatment was not significantly different from controls. The amphipod,Corophium acherusicum, accounted for most of the decrease in abundance in response to fenvalerate. The holothruroid,Leptosynpta sp. and the polychaete,Mediomastus ambiseta, increased in abundance significantly with increased concentration of fenvalerate. Combined effects of actual microcosm size and concentration of endosulfan were not significant for TNO or TNT. As in the fenvalerate experiment, adjusted abundance of small microcosms was 2.6 times that of large trays which approximated the ratio of unit area between microcosm sizes. Abundance of a few taxa responded significantly to adjusted and unadjusted unit area. Abundance of the tunicate,Molgula manhattensis, increased significantly with increased concentration of endosulfan. Abundance was affected by sample location (e.g., interiorvs exterior cores) within microcosms. Abundance adjusted to unit area resulted in significantly greater TNO in externalvs internal cores. This has importance for sequential sub-sampling of microcosms to determine temporal dynamics. Statistically significant effects were measured in benthic community structure associated with microcosm size; however, the magnitude was relatively small. There appears to be no major biological reason to select one microcosm size over the other for screening for contaminant effects. Where feasible, the small trays provide savings in sample preparation and analysis, allow more replicates where laboratory space is limiting and generate less chemical waste. These benefits may be off-set by less ‘artifacts’ associated with edge effects of larger microcosms and the need for a larger mass of sediment to accommodate additional analytical requirements (e.g., thin vertical surficial samples to refine contaminant exposure at the sediment/water interface).     

Bioavailability of selenium from meat and broccoli as determined by retention and distribution of 75Se

The concentration of selenium (Se), an essential nutrient, is variable in foods, depending, in part, on how and where foods are produced; some foods accumulate substantial amounts of Se when produced on high-Se soils. The chemical form of Se also differs among foods. Broccoli is a Se-accumulating plant that contains many methylated forms of Se, and Se bioavailability from broccoli has been reported to be low. Red meats such as pork or beef could accumulate Se when the animal is fed high-Se diets, and Se from such meats has been reported to be highly bioavailable for selenoprotein synthesis. In a further attempt to characterize the utilization of Se from broccoli and meats such as pork or beef, we have fed rats diets adequate (0.1 μg Se/g diet) in Se or high in Se (1.5 μg S/g diet), with the Se source being either high-Se broccoli or beef. Rats were then given test meals of broccoli or pork intrinsically labeled with ⁷⁵Se. When dietary Se was nutritionally adequate (0.1 μg/g diet), more ⁷⁵Se from pork than broccoli was retained in tissues; however, there were no significant differences in whole-body retention when dietary Se was high (1.5 μg/g diet). A significantly greater percentage of ⁷⁵Se from broccoli than pork was excreted in the urine and dietary Se did not affect urinary excretion of broccoli ⁷⁵Se, but the amount excreted from pork varied directly with dietary Se intake. Radiolabeled ⁷⁵Se derived from pork effectively labeled selenoproteins in all tissues examined, but ⁷⁵Se from broccoli was undetectable in selenoproteins. These differences in retention and distribution of Se from broccoli or pork are consistent with reported differences in bioavailability of Se from beef and broccoli. They also suggest that there are fewer differences in bioavailability when Se is consumed in supranutritional amounts.     

Embryogenesis induction in petals of Araujia sericifera

The embryogenic capacity of Araujia sericifera petals and some of the factors involved in the induction of embryos was investigated. The influence of 6-benzyladenine and α-naphthalene acetic acid, light intensity (90 or 5 μmol m^-2 s^-1) and silver thiosulphate (inhibitor of ethylene action) were studied. It was found that petals are an easy system in which to induce somatic embryogenesis. Plants were recovered from somatic embryos. Although 6-benzyladenine is essential for inducing an efficient response, a high dosage increased callogenesis and reduced embryogenesis. The highest rate of embryogenesis is induced with high light intensity (90–100 μmol m^-2 s^-1), even though the presence of silver thiosulphate in the medium markedly reduced embryo induction. This revised version was published online in June 2006 with corrections to the Cover Date.     

Alteration of epithelial cell lipid synthesis by n-nitrosonornicotine

Summary Changes in the lipid composition of a cell membrane due to the binding of one cell modulator may affect binding of a second modulator, whether that binding is receptor-mediated (specific) or non-receptor-mediated (nonspecific). Such altered binding interactions have been demonstrated in oral epithelial cells, wherein N-nitrosonornicotine (NNN), a nonspecific ligand, enhances phorbol ester binding. To characterize membrane changes that may be responsible for such an effect, the current study examined lipid changes in hamster oral epithelial (HCP) cells associated with NNN binding. HCP cultures at two cell densities, 5 × 10⁶ cells/100 mm plate (subconfluent cultures) or 10 × 10⁶ cells/100 mm plate (confluent cultures) were incubated in Keratinocyte-Serum-Free Medium and exposed to 10μM NNN or DMSO (solvent control) for 48 h. Lipids were labeled with¹⁴C-acetate, then extracted, separated by thin layer chromatography, and the¹⁴C-lipids located by autoradiography and counted. Exposure of subconfluent cultures to NNN for 48 h, with¹⁴C-acetate present during the final 24 h, resulted in altered phospholipid and fatty acid labeling. Phospholipid labeling increased slightly in the presence of NNN compared to controls, while fatty acid labeling showed a modest but significant decrease in the presence of NNN. Similar changes occurred in the confluent cultures. Prelabeling of lipids in subconfluent cultures, followed by exposure to NNN in the absence of radiolabel, resulted in significantly (P<0.05) greater phospholipid labeling in the presence of NNN compared to control cultures. At the same time, fatty acid labeling decreased significantly. The NNN caused the cells to have decreased levels of several long chain polyunsaturated fatty acids and an increased amount of one long chain saturated (24:0) fatty acid. Significant differences were detected in the synthesis of various lipid classes between subconfluent and confluent cultures, but the presence of the NNN did not affect these differences. These results suggest that there is a shift of fatty acid type in the cells’ phospholipids in the presence of NNN, a finding that may reflect the membrane’s adaptation to the modulator’s presence.     

GIS-based seasonal pattern of Rhinopithecus roxellana’s habitat selection in Shennongjia Reserve, Central China

Rhinopithecus roxellana’s habitat condition is directly related to its long-term survival and reproduction. Research, with large-scale, on R. roxellana’s habitat selection of seasonal changes is conducive to the protection and construction of its habitat, and it is essential protecting the rare species. Our research is based on the results of previous studies in biological and behavioral ecological field. With the support of GIS and RS technology, we conducted a lot of field investigations. In addition, we also took R. roxellana’s selection bias of seven kinds of ecological factors into consideration. Through the above efforts, we got a selection intensity distribution layer about R. roxellana’s habitat selection of seasonal changes. Our study shows that in spring, the area of weak intensity is 1507.96 hm² while less weak area is 33868.72 hm². The strong intensity area is 266 hm² while the less strong area is 36818.84 hm².
In summer, the area of weak intensity is 4683.4 hm² while less weak area is 28392.4 hm². The strong intensity area is 4078.52 hm² while the less strong area is 35307.2 hm².
In autumn, the area of weak intensity is 1972.08 hm² while less weak area is 33254.72 hm². The strong intensity area is 1516.84 hm² while the less strong area is 35717.88 hm².
In winter, the area of weak intensity is 542.76 hm² while less weak area is 28230.84 hm². The strong intensity area is 392.44 hm² while the less strong area is 43295.48 hm².
The results show that the most forestry areas of the Shennongjia Mt. lie in strong intensity area and these areas provides optimal habitat for the Snub-nosed Monkey.
The distribution layer analyses show that eastern part of the Shennongjia area is coincidence with the current natural distribution of the Snub-nosed Monkey, whereas north-western, south-western and southern part of the area is located in the weak intensity areas and is unfit for the Snub-nosed Monkey. In the central part, the strong intensity areas are fragmented by the highways and no Snub-nosed Monkey is found in this highly disturbed area. However, it is probably a potential habitat for the Snub-nosed Monkey.
Survival and reproduction of the Snub-nosed Monkey was ensured by large and continuous habitat in the eastern part of the Shennongjia Mt. Much effort is needed to intensify the connection of the fragmented central area of the Shennongjia Mt.     

Root morphology and cadmium uptake kinetics of the cadmium-sensitive rice mutant

To understand the physiological mechanism that confers Cd sensitivity, root morphology and Cd uptake kinetics of the Cd-sensitive mutant and wild type rice were investigated. The root length, root surface area, and root number of mutant rice decreased more significantly with increasing Cd concentration in growth media compared with the wild type rice. The uptake kinetics for ¹⁰⁹Cd²⁺ in roots of both the mutant and wild type rice were characterized by a rapid linear phase during the first 6 h and a slower linear phase during the subsequent period. Concentration-dependent Cd²⁺ influx in both species could be characterized by the Michaelis-Menten equation, with similar apparent K_m values for mutant and wild type rice (2.54 and 2.37 μM, respectively). However, the V_max for Cd²⁺ influx in mutant root cells was nearly 2-fold higher than that for wild type rice, indicating that enhanced absorption into the root is one of the mechanisms involved in Cd sensitivity in mutant rice.     

GIS-based seasonal pattern of Rhinopithecus roxellana’s habitat selection in Shennongjia Reserve, Central China

Rhinopithecus roxellana’s habitat condition is directly related to its long-term survival and reproduction. Research, with large-scale, on R. roxellana’s habitat selection of seasonal changes is conducive to the protection and construction of its habitat, and it is essential protecting the rare species. Our research is based on the results of previous studies in biological and behavioral ecological field. With the support of GIS and RS technology, we conducted a lot of field investigations. In addition, we also took R. roxellana’s selection bias of seven kinds of ecological factors into consideration. Through the above efforts, we got a selection intensity distribution layer about R. roxellana’s habitat selection of seasonal changes. Our study shows that in spring, the area of weak intensity is 1507.96 hm² while less weak area is 33868.72 hm². The strong intensity area is 266 hm² while the less strong area is 36818.84 hm².
In summer, the area of weak intensity is 4683.4 hm² while less weak area is 28392.4 hm². The strong intensity area is 4078.52 hm² while the less strong area is 35307.2 hm².
In autumn, the area of weak intensity is 1972.08 hm² while less weak area is 33254.72 hm². The strong intensity area is 1516.84 hm² while the less strong area is 35717.88 hm².
In winter, the area of weak intensity is 542.76 hm² while less weak area is 28230.84 hm². The strong intensity area is 392.44 hm² while the less strong area is 43295.48 hm².
The results show that the most forestry areas of the Shennongjia Mt. lie in strong intensity area and these areas provides optimal habitat for the Snub-nosed Monkey.
The distribution layer analyses show that eastern part of the Shennongjia area is coincidence with the current natural distribution of the Snub-nosed Monkey, whereas north-western, south-western and southern part of the area is located in the weak intensity areas and is unfit for the Snub-nosed Monkey. In the central part, the strong intensity areas are fragmented by the highways and no Snub-nosed Monkey is found in this highly disturbed area. However, it is probably a potential habitat for the Snub-nosed Monkey.
Survival and reproduction of the Snub-nosed Monkey was ensured by large and continuous habitat in the eastern part of the Shennongjia Mt. Much effort is needed to intensify the connection of the fragmented central area of the Shennongjia Mt.