[Seroprevalence of the specific antibody against Toxoplasma gondii among patients with hematological diseases]

OBJECTIVE

To investigate the seroprevalence of Toxoplasma gondii infections among patients with hematological diseases, so as to provide insights into improving the prognosis and quality of life among patients with hematological diseases.

METHODS

A total of 240 patients with hematological diseases (including 170 patients with hematological tumors and 70 patients with non-tumor hematological diseases) admitted to The Affiliated Hospital of Putian University during the period from January 1, 2021 through October 10, 2023 and 500 healthy volunteers in the hospital during the same period were enrolled. Subjects' demographics and serum samples were collected, and serum specific IgG and IgM antibodies against T. gondii were detected using the chemiluminescence assay, with any of a positive IgG or IgM antibody defined as a positive T. gondii infection. The seroprevalence of specific IgG and IgM antibodies against T. gondii was compared between patients with hematological diseases and healthy volunteers.

RESULTS

The mean age (F = 2.034, P > 0.05) and gender distribution (χ2 = 0.462, P > 0.05) were comparable among patients with hematological tumors, patients with non-tumor hematological diseases and healthy volunteers, and there was no significant difference in the proportion of history of cat or dog contacts between patients with hematological diseases and healthy volunteers (χ2 = 0, P > 0.05). The seroprevalence of anti-T. gondii antibody was significantly higher among patients with hematological diseases than among healthy volunteers (15.8% vs. 0.6%; χ2 = 71.902, P < 0.01), and there was a significant difference in the seroprevalence of anti-T. gondii antibody among patients with hematological tumors (18.2%), patients with non-tumor hematological diseases (10.0%) and healthy volunteers (χ2 = 78.327, P < 0.01). The seroprevalence of anti-T. gondii antibody was significantly higher among patients with hematological tumors and non-tumor hematological diseases than among healthy volunteers (both P values < 0.05), while no significant difference was seen in the seroprevalence of anti-T. gondii antibody between patients with hematological tumors and non-tumor hematological diseases (P > 0.05). In addition, the proportion of history of cat or dog contacts was significantly higher among patients with hematological diseases that were positive for serum anti-T. gondii anti-body than among those negative for serum anti-T. gondii antibody (21.1% vs. 5.4%; χ2 = 8.653, P < 0.05).

CONCLUSIONS

There is a high seroprevalene rate of T. gondii infections among hematological diseases, which is significantly greater than that among healthy volunteers.

Association of Platelet Desialylation and Circulating Follicular Helper T Cells in Patients With Thrombocytopenia

Thrombocytopenia is a multifactorial condition that frequently involves concomitant defects in platelet production and clearance. The physiopathology of low platelet count in thrombocytopenia remains unclear. Sialylation on platelet membrane glycoprotein and follicular helper T cells (TFHs) are thought to be the novel platelet clearance pathways. The aim of this study was to clarify the roles of platelet desialylation and circulating TFHs in patients with immune thrombocytopenia (ITP) and non-ITP thrombocytopenia. We enrolled 190 patients with ITP and 94 patients with non-ITP related thrombocytopenia including case of aplastic anemia (AA) and myelodysplastic syndromes (MDS). One hundred and ten healthy volunteers were included as controls. We found significantly increased desialylated platelets in patients with ITP or thrombocytopenia in the context of AA and MDS. Platelet desialylation was negatively correlated with platelet count. Meanwhile, the circulating TFH levels in patients with thrombocytopenia were significantly higher than those of normal controls, and were positively correlated with desialylated platelet levels. Moreover, TFHs-related chemokine CXCL13 and apoptotic platelet levels were abnormally high in ITP patients. The upregulation of pro-apoptotic proteins and the activation of the MAPK/mTOR pathway were observed in the same cohort. These findings suggested that platelet desialylation and circulating TFHs may become the potential biomarkers for evaluating the disease process associated with thrombocytopenia in patients with ITP and non-ITP.

Doxorubicin/Nucleophosmin Binding Protein-Conjugated Nanoparticle Enhances Anti-leukemia Activity in Acute Lymphoblastic Leukemia Cells in vitro and in vivo

Acute lymphoblastic leukemia (ALL) is an aggressive malignancy. Adults with ALL have more than 50% relapse rates. We have previously validated that overexpression of nucleophosmin (NPM) is involved in the multidrug resistance (MDR) development during ALL; and a synthetically engineered recombinant NPM binding protein (NPMBP) has been developed in our group; NPMBP and doxorubicin (DOX) can be conjugated in a nanoparticle-based drug delivery system named DOX-PMs-NPMBP to counteract MDR during ALL. Here, we evaluated the antileukemia potential of DOX-PMs-NPMBP in resistant ALL cells. This study demonstrates that DOX-PMs-NPMBP significantly enhances chemosensitivity to DOX in ALL cells. Despite at variable concentrations, both resistant and primary ALL cells from relapsed patients were sensitive to DOX-PMs-NPMBP. In detail, the half maximal inhibitory concentration (IC50) values of DOX-PMs-NPMBP were between 1.6- and 7.0-fold lower than those of DOX in cell lines and primary ALL cells, respectively; and apoptotic cells ratio was over 2-fold higher in DOX-PMs-NPMBP than DOX. Mechanistically, p53-driven apoptosis induction and cell cycle arrest played essential role in DOX-PMs-NPMBP-induced anti-leukemia effects. Moreover, DOX-PMs-NPMBP significantly inhibited tumor growth and prolonged mouse survival of ALL xenograft models; and no systemic toxicity occurrence was observed after treatment during follow-up. In conclusion, these data indicate that DOX-PMs-NPMBP may significantly exert growth inhibition and apoptosis induction, and markedly improve DOX antileukemia activity in resistant ALL cells. This novel drug delivery system may be valuable to develop as a new therapeutic strategy against multidrug resistant ALL.

E35 ablates acute leukemia stem and progenitor cells in vitro and in vivo

Leukemia stem cells (LSCs) have critical functions in acute leukemia (AL) pathogenesis, participating in its initiation and relapse. Thus, identifying new molecules to eradicate LSCs represents a high priority for AL management. This work identified E35, a novel Emodin derivative, which strongly inhibited growth and enhanced apoptosis of AL stem cell lines, and primary stem and progenitor cells from AL cases, while sparing normal hematopoietic cells. Furthermore, functional assays in cultured cells and animals suggested that E35 preferentially ablated primitive leukemia cell populations without impairing their normal counterparts. Moreover, molecular studies showed that E35 remarkably downregulated drug-resistant gene and dramatically inhibited the Akt/mammalian target of rapamycin signaling pathway. Notably, the in vivo anti-LSC activity of E35 was further confirmed in murine xenotransplantation models. Collectively, these findings indicate E35 constitutes a novel therapeutic candidate for AL, potentially targeting leukemia stem and progenitor cells.

CHANGES OF WNT/B-CATENIN SIGNALING AND DIFFERENTIATION POTENTIAL OF BONE MARROW MESENCHYMAL STEM CELLS IN PROCESS OF BONE LOSS IN OVARIECTOMIZED RATS

Background

In vitro studies of the changes about osteoblastogenesis and adipogenesis potential of BMSCs were not clear. As it is the critical pathway for osteogenic differentiation and bone formation, whether or not Wnt/β-catenin signalling is involved in the changes of osteogenic and adipogenic potential of BMSCs and participates in bone content decrease of ovariectomized (OVX)osteoporosis rats has been rarely reported.

Material/Methods

BMSCs from femurs of ovariectomzed rats were isolated and cultured in vitro. The proliferation potential of BMSCs was analysed by CCK-8 assays . Osteoblastic and adipogenic differentiation potential of the BMSCs was assessed by ALP activity assay, Alizarin red S staining, Oil red O staining and RT-PCR analysis.

Results

The results demonstrated that BMSCs from bilateral ovariectomization rats were endowed with lower proliferation and osteoblastic differentiation potential but higher adipogenic potential than the control group in vitro. In addition, β-catenin was found to have been decreased in OVX BMSCs, indicating that Wnt/β-catenin signalling pathways were suppressed in OVX BMSCs .

Conclusions

Results suggested that changes in the Wnt canonical signalling pathway may be related to imbalances of osteogenic and adipogenic potential of BMSCs, and this may be an important factor related to bone content decrease in ovariectomized osteoporosis rats.

Diagnostic potential of urinary monocyte chemoattractant protein-1 for Alzheimer's disease and amnestic mild cognitive impairment

BACKGROUND AND PURPOSE

The chemokine monocyte chemoattractant protein-1 (MCP-1) is involved in the pathogenesis of Alzheimer's disease (AD). This study aimed to investigate whether urinary MCP-1 can distinguish patients with AD, patients with amnestic mild cognitive impairment (aMCI) and cognitively normal (CN) subjects.

METHODS

A total of 754 participants, including 97 patients with AD, 50 patients with aMCI and 84 age- and sex-matched CN controls as well as a cohort of 523 CN subjects of different ages, were enrolled from five hospitals located in different areas of China. Urinary MCP-1 levels were determined using enzyme-linked immunosorbent assays. The correlations between urinary MCP-1 levels and cognition test scores or age were analysed. The optimal diagnostic sensitivity and specificity were determined using receiver operating characteristic curve analysis.

RESULTS

In the cohort of CN subjects of different ages, urinary MCP-1 levels increased with ageing and were correlated with age. The urinary MCP-1 levels were higher in females than in males. In the cohort composed of patients with AD, aMCI and age- and sex-matched CN controls, urinary MCP-1 levels were significantly higher in patients with AD and aMCI than in CN controls. There were no differences in urine MCP-1 levels between the AD group and the aMCI group. The urinary MCP-1 levels were correlated with the Mini-Mental State Examination scores and age, and were able to differentiate patients with AD and aMCI from CN subjects.

CONCLUSIONS

Urinary MCP-1 is a potential biomarker for the diagnosis of AD and aMCI.

Integrated bioinformatics analysis of the crucial candidate genes and pathways associated with glucocorticoid resistance in acute lymphoblastic leukemia

Glucocorticoids (GC) are the foundation of the chemotherapy regimen in acute lymphoblastic leukemia (ALL). However, resistance to GC is observed more frequently than resistance to other chemotherapy agents in patients with ALL relapse. Moreover, the mechanism underlying the development of GC resistance in ALL has not yet been fully uncovered. In this study, we used bioinformatic analysis methods to integrate the candidate genes and pathways participating in GC resistance in ALL and subsequently verified the bioinformatics findings with in vitro cell experiments. Ninety‐nine significant common differentially expressed genes (DEGs) associated with GC resistance were determined by integrating two gene profile datasets, including GC‐sensitive and ‐resistant samples. Using Kyoto Encyclopedia of Genes and Genomes (KEGG) and REACTOME pathways analysis, the signaling pathways in which DEGs were significantly enriched were clustered. The GC resistance‐related biologically functional interactions were visualized as DEG‐associated Protein–Protein Interaction (PPI) network complexes, with 98 nodes and 127 edges. MYC, a node which displayed the highest connectivity in all edges, was highlighted as the core gene in the PPI network. Increased C‐MYC expression was observed in adriamycin‐resistant BALL‐1/ADR cells, which we demonstrated was also resistant to dexamethasone. These results outlined a panorama in which the solitary and scattered experimental results were integrated and expanded. The potential promising target of the candidate pathways and genes involved in GC resistance of ALL was concomitantly revealed.

Effect of nucleolin on adriamycin resistance via the regulation of B-cell lymphoma 2 expression in Burkitt's lymphoma cells

Nucleolin (NCL, C23) is an important nucleocytoplasmic multifunctional protein. Due to its multifaceted profile and high expression in cancer, NCL is considered to be a marker of drug resistance associated with chemotherapy. However, the biochemical mechanisms in which NCL suppresses drug sensitivity in several cancers have yet to be fully elucidated. This study aims to explore the effect of NCL on drug sensitivity and its potential mechanism in CA46 Burkitt's lymphoma (BL) cells. CA46 BL cells were transfected with lentiviruses carrying the NCL gene (CA46-NCL-overexpression, CA46-NCL-OE), or shRNA sequences that target the endogenous NCL gene (CA46-NCL-knockdown, CA46-NCL-KD). Adriamycin (ADM) IC50 levels for CA46-NCL-overexpressed (OE), CA46-NCL-OE control (OEC), CA46-NCL-knockdown (KD), and CA46-NCL-KD control (KDC) cells were 0.68 ± 0.06 μg/ml, 0.68 ± 0.06 μg/ml, 0.68 ± 0.06 μg/ml, and 0.30 ± 0.04 μg/ml, respectively. Apoptosis rates were significantly increased following NCL KD, whereas the opposite effect was noted in OE cells. A significant reduction of B-cell lymphoma 2 (Bcl-2) mRNA and protein levels in KD cells was observed, while OE cells displayed the opposite effect. The stability of Bcl-2 mRNA was influenced by NCL levels, the half-life of which was extended after NCL-OE, whereas it was reduced in KD cells. Finally, results of RNA-immunoprecipitation assays indicated that NCL could bind to Bcl-2 mRNA in CA46 cells. Taken together, these results suggested that NCL could mediate Bcl-2 expression and stability, and thus enhance ADM resistance in CA46 BL cells.

Emodin and Its Combination with Cytarabine Induce Apoptosis in Resistant Acute Myeloid Leukemia Cells in Vitro and in Vivo

Background/Aims: Acute myeloid leukemia (AML) remains a hematologic malignancy with poor survival and a high risk of relapse, which is mainly caused by the emergence of multidrug resistance (MDR). The identification of novel agents to improve therapeutic strategies becomes important priority for AML treatment. It has been shown that emodin has therapeutic effects on many kinds of human malignant tumors. In this study, we investigated the anti-leukemia effects of emodin alone or in combination with cytarabine (Ara-C) on multidrug-resistant AML HL-60/ADR cells and in a mouse xenograft model of human highly tumorigenic AML HL-60/H3 cells. The underlying mechanism was also addressed. Methods: Cell viability after treatment was measured by MTT assay. The DNA fragmentation assay, Annexin V-PE/7-AAD, AO/EB staining, and electron microscopy were introduced to assess the apoptotic induction effects. Changes in protein expression in the Akt and ERK signaling pathways were determined by western blotting. In vivo antileukemia effects on HL-60/H3 xenograft model and overall mouse survival outcomes were further analyzed in this study. Results: Emodin dose-dependently induced growth inhibition and apoptotic effects in resistant HL-60/ADR cells in vitro as well as in the HL-60/H3 xenograft models in vivo. Moreover, emodin significantly enhanced chemosensitivity of AML cells to Ara-C, inhibited leukemic cell growth, and improved survival in the mouse xenograft model of AML. Dual targeting of Akt and ERK signaling pathways might contribute to the anti-leukemia effects on AML cells in vitro and in vivo. Conclusion: Emodin and its combination with Ara-C may be considered a promising therapeutic approach in AML and worthy of further investigation.

Integration of bioinformatics and experiments to identify TP53 as a potential target in Emodin inhibiting diffuse large B cell lymphoma

Non-Hodgkin's Lymphoma (NHL) is a group of lymphoid malignancies with unsatisfactory treatment effect in some aggressive subtypes, including diffuse large B cell lymphoma (DLBCL). Emodin is an anthraquinone with potent anti-cancer activities. However, the molecular mechanism of Emodin repressing aggressive NHL remains to be revealed in detail. This study delineated the active mechanism of Emodin action in aggressive NHL by using bioinformatics analysis and in vitro assay. 4 Emodin's primary direct protein targets (DPT) were identified and the DPTs-associated proteins/genes were predicted. Those Emodin-related proteins/genes were subject to enrich Emodin-associated pathways, from which 3 significantly NHL-related signal pathways were refined identified. Advanced integrated analysis exhibited TP53 and PI3K as the significant molecule and pathway by which Emodin may function in NHL. To verify those bioinformatics findings, effects of Emodin and E35, a novel derivative of emodin were investigated on DLBCL cell lines SU-DHL4. Emodin and E35 suppressed proliferation and induced apoptosis of SU-DHL4 cells in a time- and dose-dependent manner. Emodin and E35 declined TP53 protein expression and decreased phosphorylation of PI3K/AKT protein in a dose-dependent manner. All of above showed that combined bioinformatics analysis with experiments offered a novel approach for outlining the mechanisms of Emodin action in DLBCL with convenience and integrity.

Wetting behavior of water on silicon carbide polar surfaces

Technically important wide band-gap semiconductors such as GaN, AlN, ZnO and SiC are crystallized in polar structures.

The effect of N-acetyl-glucosamine on stratum corneum desquamation and water content in human skin

Alpha-hydroxy acids have been used topically to treat skin for both dermatological and cosmetic problems for many years. Though there are many known benefits of the use of alpha-hydroxy acids on skin, there have been recent reports that topical treatments with alpha-hydroxy acids increase skin damage resulting from UVB. Additionally, high concentrations of alpha-hydroxy acids by themselves have also been found to cause skin irritation. In order to find alternatives to alpha-hydroxy acids, we investigated a variety of amino sugar compounds that were previously reported to inhibit the reaggregation of dissociated corneocytes by modulating cellular adhesion. In vivo, we observed that topical treatments with a formulation containing N-acetyl-glucosamine (NAG) led to an increase in skin moisturization, a decrease in skin flakiness, and the normalization of stratum corneum exfoliation. In vitro, we observed an upregulation of differentiation markers, keratin 10 and involucrin, in keratinocytes treated with NAG. CD44 is a lectin cell adhesion molecule that is also expressed in keratinocytes. Amino sugars such as NAG may competitively bind to CD44, modulating keratinocyte cellular adhesion. We hypothesize that these amino sugars modulate keratinocyte cellular adhesion and differentiation, leading to the normalization of stratum corneum exfoliation. We propose the use of amino sugars such as NAG as alternative compounds to replace the use of alpha-hydroxy acids in skin care.

Normal human keratinocytes pretreated with damaged mRNA are resistant to UVB damage and exhibit increased DNA repair

Treatment of normal human keratinocytes with UVC-irradiated rabbit globin mRNA 24 h before and after UVB exposure increased the survival of the human keratinocytes. We also observed that UVC-damaged mRNA reduced the formation of sunburn cells in skin models. We next tested the effects of UVC-damaged mRNA on cellular repair of DNA. DNA repair was evaluated using 2 assay methods. The first method used a damaged plasmid that is transfected back into the cell where it is repaired by the host cell repair mechanism. In these experiments, we observed that externally added UVC-damaged rabbit globin mRNA enhanced the repair of a plasmid transfected into the host keratinocyte cells. The second method used to determine the effects on DNA repair was direct immunostaining for thymidine-thymidine dimers (TT dimers) in histological sections of the skin models. Skin models were irradiated with UVB and then fixed immediately or after 24 h and stained for TT dimers. UVB irradiation immediately caused an increase in the number of stained keratinocytes in the skin. The number of stained cells decreased in skin fixed 24 h after UVB. This is due to repair of the TT dimers and their removal. Sections of skin models pretreated with UV-damaged mRNA exhibit greater removal of these TT dimers after 24 h. The above evidence suggests that damaged mRNA can trigger a host cell DNA repair pathway.

Temperature-jump investigations of the kinetics of hydrogel nanoparticle volume phase transitions

The dynamics of the deswelling and swelling processes in thermoresponsive poly-N-isopropylacrylamide (pNIPAm) hydrogel nanoparticles have been studied by using time-resolved transmittance measurements, in combination with a nanosecond laser-induced temperature-jump (T-jump) technique. A decrease in the solution transmittance associated with deswelling of the particles has been observed as the solution temperature traverses the volume phase transition temperature of the particles. Upon inducing the T-jump, the deswelling transition only occurs in a small percentage (<10%) of the particle volume, which was found to be a thin periphery layer of the particles. The particle deswelling occurs on the microsecond time scale, and as shown previously, the collapse time can be tuned via adding small amounts of hydrophobic component to the particle shell. In contrast, the reswelling of the particles was thermodynamically controlled by bath equilibration, and only small differences in particle reswelling kinetics were found due to sluggish heat dissipation (millisecond time scale) from the sample cell.

Human keratinocytes respond to osmotic stress by p38 map kinase regulated induction of HSP70 and HSP27

Human skin is exposed to an environment that varies in humidity from 100 to 0%, leading to seasonal variations in the condition of the skin. Exposure to a low humidity environment creates an osmotic gradient across the stratum corneum, which is known to modulate cutaneous barrier function. Heat shock proteins protect against stress-induced destabilization of proteins. We investigated whether osmotic shock (sorbitol) induced a heat shock protein response in normal human keratinocytes, and used heat shock as a positive control. Both heat shock and osmotic stress (200 and 300 mM sorbitol) clearly induced heat shock proteins 70 and 27 mRNA levels. The induction of heat shock protein 70 mRNA levels by osmotic stress peaked at 16 h and persisted until 24 h, whereas upregulation of heat shock protein 70 mRNA levels by heat peaked at 2 h and returned to baseline levels by 6 h. Sorbitol also increased heat shock protein 70 levels in a concentration-dependent manner. The kinetics of heat shock protein 27 mRNA induction by osmotic stress and heat were similar with peak induction at 6 h. The mitogen activated protein kinase family of proteins plays an important part in the coordination of gene responses to various stress conditions. We have demonstrated that the p38 mitogen activated protein kinase was strongly activated by 200 mM and 300 mM sorbitol. The specific p38 mitogen activated protein kinase inhibitor PD169316 almost completely blocked heat shock protein 70 mRNA induction by 200 mM and 300 mM sorbitol and completely suppressed heat shock protein 27 mRNA induction with 200 mM sorbitol. PD169316 also counteracted upregulation of heat shock protein 70 levels by sorbitol. These data indicate that keratinocytes respond to osmotic stress by p38 mitogen activated protein kinase regulated induction of heat shock proteins. This molecular pathway may be relevant for the mechanisms regulating the response of human skin to variations in environmental humidity.

Interfacial nonradiative energy transfer in responsive core-shell hydrogel nanoparticles

Fluorescently labeled core-shell latex particles composed mainly of the thermoresponsive polymer poly-N-isopropylacrylamide (p-NIPAm) have been synthesized such that an energy transfer donor (phenanthrene) and an energy transfer acceptor (anthracene) are covalently localized in the core and shell, respectively. When the thermally induced particle deswelling is interrogated by photon correlation spectroscopy (PCS), a continuous (non-first order) phase transition is observed. Conversely, when the nonradiative energy transfer (NRET) efficiency is used to probe the collapse of these same particles, the phase transition event is observed to occur over a much smaller temperature range and approaches first-order (discontinuous) behavior. Furthermore, core-shell particles with differing shell thicknesses display identical phase transition temperatures when PCS is used to monitor the transition, while NRET measurements show a clear increase in collapse temperature as the shell thickness is increased. These apparently contradictory results are discussed in terms of a radial phase coexistence that exists in the microgel particles, which arises from a similarly radial inhomogeneity in the cross-linker concentration. The prospects for the NRET technique as a molecular-scale probe of nanostructured microgels are also discussed.

Tunable swelling kinetics in core--shell hydrogel nanoparticles

Thermoresponsive, core--shell poly-N-isopropylacrylamide (p-NIPAm) nanoparticles (microgels) have been synthesized by seed and feed precipitation polymerization, and the influence of chemical differentiation between the core and shell polymers on the phase transition kinetics and thermodynamics has been examined. The results suggest that the core--shell architecture is a powerful one for the design of colloidal "smart gels" with tunable properties. To examine these materials, differential scanning calorimetry (DSC), (1)H NMR, and temperature-programmed photon correlation spectroscopy (TP-PCS) have been employed. These measurements show that the addition of small concentrations of a hydrophobic monomer (butyl methacrylate, BMA) into the particle shell produces large decreases in the rate of thermo-induced particle collapse. Conversely, these low levels of hydrophobic modification do not perturb the thermodynamics of the particle phase transition. When these results are examined in light of previous studies of macroscopic hydrogels, they suggest that the formation of a thin, stable skin layer at the particle exterior during the early stages of particle collapse is the rate limiting factor in particle deswelling. Finally, the hydrophobicity (BMA content) of the shell determines the magnitude of the hydrogel collapse rate, while the thickness of the BMA containing region does not impact the observed kinetics. Together, these results suggest that control over the kinetics of microgel deswelling events can be accomplished simply by modification of the particle periphery, and therefore do not require homogeneous modification of the entire polymer structure.

Successful separation of apoptosis and necrosis pathways in HaCaT keratinocyte cells induced by UVB irradiation

UVB irradiation can induce apoptotic, necrotic, and differentiation pathways in normal human keratinocytes. The present study was undertaken to determine at what dose of UVB each of these pathways is induced and whether these pathways are distinct or overlapping. We have observed that UVB induces fragmentation of DNA in human HaCaT keratinocytes, in a bimodal manner. Low doses of UVB, 5-20 mJ/cm2, increase the levels of apoptosis as shown by increased levels of fragmented DNA, Fas, PARP, and FasL protein, and the number of apoptotic cells as assessed by FACS analysis. At higher doses of UVB (20 and 30 mJ/cm2) the number of apoptotic cells becomes reduced, as does the amount of Fas, PARP, and FasL protein. At these higher doses, cell viability is decreased as measured by DNA synthesis (BrdU labeling) neutral red uptake, which represents an increasing necrotic phenotype. Expression of markers of keratinocyte differentiation, involucrin, keratin K1, and keratin K10, are also observed to decrease with increasing UVB dose. These changes are accompanied by a further increase in DNA fragmentation. We conclude that low doses of UVB (5-20 mJ/cm2) induced an apoptotic pathway, whereas increasing doses (greater than 20 mJ/cm2) of UVB produce a direct necrotic effect and inhibit terminal differentiation.

[A method of preparing the section of eye tissue for transmission electron microscopy]

A method of preparing the section of eye tissue for transmission electron microscopy (TEM) is recommended. The tissue was prefixed with a mixed solution of 4% paraformaldehyde and 2.5% glutaraldehyde and followed by softening in 3% EDTA solution for 20 minutes, then the tissue was fixed in 1% osmium tetroxide, dehydrated in series acetone, infiltrated in Epox 812 for a longer, and embeded. Ultrathin sections were cut with glass knives or diamond knife, stained with uranyl acetate and lead citrate and examined with H600-IV. The advantage of this method is that the ultrastructures of tissues are well preserved without any damage and distortion. The main points of the procedure of preparation have been discussed.

[The standardized techniques for preparing samples used in pathologic diagnostic transmission electron microscopy]

Transmission electron microscopy (TEM) has been used widespreadly in the field of diagnostic pathology. Based on the practical domestic condition and aimed at fully satisfying the needs of the pathologic diagnostic TEM, a set of standardized techniques were established for preparing different kinds of samples. The techniques included the preparation and storage of fixatives and embedding media, the requirement of sampling, the 5 h and 24 h embedding procedures for fresh specimens, the embedding procedure for suspension specimens and specimens collected from fine needle aspiration biopsy, as well as the procedures for preparing samples taken from paraffin embedded blocks or paraffin sections. In practical use, we found that the advantage of these techniques was that the ultrastructures of the tissues and cells were well preserved and they perfectly met the needs for diagnosis of tumors, kidney diseases, et al. The main points of the standardized techniques have been discussed in detail in this paper.

[Effects of smoking on interleukin-2 and its receptor system in human peripheral blood]

42 healthy male smokers and 42 healthy male nonsmokers matched in age and life style were strictly chosen into the study from Beijing urban and rural areas. Peripheral blood mononuclear cells(PBMCs) were separated and then stimulated by PHA under 37 degrees C, 5% CO2 condition. Immunochemical methods were applied in testing the synthesis of interleukin 2(IL-2) and the expression of its membrane receptor (mIL-2R) and the level of soluble receptor (sIL-2R) in serum. The results showed that when compared with nonsmokers, stimulated PBMC from smokers had significant higher percentage of mIL-2R positive cells (P < 0.05) in vitro. Levels of sIL-2R in serum of smokers were also significantly higher than those of nonsmokers (P < 0.05). The percentage of IL-2 secrete cells of smokers had higher tendency (P = 0.08). These data indicated that the immune function of smokers and nonsmokers are different concerning the IL-2 and its receptor system.

[Ultrastructural observation of SC1001-sodium on brain neurons kindled seizures by coriaria lactone in rabbits]

The ultrastructural changes of hippocampus and cerebral cortex neurons were derived from the rabbits kindled by coriaria lactone and from the kindled rabbits after treatment with SC1001 Na. The results of experiment showed that the hippocampus and cerebral cortex neurons in the kindled group had some degenerative changes, such as the swelling mitochondria, dilated rough endoplasmic reticulum and Golgi complexes when the injuries of neurons were not serious, but the seriously injured neurons were subjected to rupture of the cell membrane and solution of most organella, with only a small amount of degenerative organella. In the group treated with SC1001 Na, the ultrastructure of brain neurons demonstrated a tendency of recreation to normal which showed that SC1001 Na had cured many of the degenerative brain cells. This suggested that active treatment is very important for the epileptic patients.

[Observation of monoclonal antibody E4B7D5 inhibitory effect on leptospiral adherence using scanning electron microscope]

BALB/c mice were immunized intraperitoneally with outer envelopes of serogroup icterohaemorrhagiae lai serovar strain 017 leptospires. Monoclonal antibody (McAb) E4B7D5 against outer envelopes (IgG1, agglutinating titre 1:25,600) was produced by hybridoma technique. Passive immunoprotection experiments have demonstrated the immunoprotection of McAb E4B7D5 against strain 017 leptospires. Effect of McAb E4B7D5 on leptospiral adherence to the surface of normal human pulmonary embryonic fibroblasts was observed by using scanning electron microscope. The results indicated that the leptospiral adherence noted in various agglutinating titre McAb E4B7D5 groups was less frequent than that in the three control groups. It was concluded that the inhibitory effect of McAb E4B7D5 on leptospiral adherence may play a role in the immunoprotection.