251
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Zhou P, Regenstein J. Determination of Total Protein Content in Gelatin Solutions with the Lowry or Biuret Assay. J Food Sci 2006. [DOI: 10.1111/j.1750-3841.2006.00151.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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252
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Zhou W, Feng MQ, Li JY, Zhou P. Studies on the preparation, crystal structure and bioactivity of ginsenoside compound K. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2006; 8:519-27. [PMID: 16931427 DOI: 10.1080/10286020500208600] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Microbial transformation of Panaxnotoginseng saponins (PNS) using Aspergillus niger afforded, as the main metabolite, ginsenoside compound K (20-O-beta-glucopyranosyl-20(S)-protopanaxadiol). Its structure was determined spectroscopically and by X-ray analysis, and this is the first time the crystal structure of ginsenoside has been reported. In comparison with ginsenoside Rb1, the pro-drug for this metabolite, compound K exhibits potent cytotoxic activity against tumor cell lines. The mean concentrations of compound K needed to inhibit the proliferation of cells by 50% (IC50) were 12.7, 11.4, 8.5 and 9.7 microM for mouse high-metastatic melanoma (B16-BL6), human hepatoma (HepG2), human myeloid leukemia (K562) and human high-metastatic lung carcinoma (95-D) cell lines, respectively. The data show that ginsenoside compound K is a good antitumor drug candidate.
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253
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McNerney ME, Lee KM, Zhou P, Molinero L, Mashayekhi M, Guzior D, Sattar H, Kuppireddi S, Wang CR, Kumar V, Alegre ML. Role of natural killer cell subsets in cardiac allograft rejection. Am J Transplant 2006; 6:505-13. [PMID: 16468959 DOI: 10.1111/j.1600-6143.2005.01226.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To achieve donor-specific immune tolerance to allogeneic organ transplants, it is imperative to understand the cell types involved in acute allograft rejection. In wild-type mice, CD4(+) T cells are necessary and sufficient for acute rejection of cardiac allografts. However, when T-cell responses are suboptimal, such as in mice treated with costimulation-targeting agents or in CD28-deficient mice, and perhaps in transplanted patients taking immunosuppressive drugs, the participation of other lymphocytes such as CD8(+) T cells and NK1.1(+) cells becomes apparent. We found that host NK but not NKT cells were required for cardiac rejection. Ly49G2(+) NK cells suppressed rejection, whereas a subset of NK cells lacking inhibitory Ly49 receptors for donor MHC class I molecules was sufficient to promote rejection. Notably, rejection was independent of the activating receptors Ly49D and NKG2D. Finally, our experiments supported a mechanism by which NK cells promote expansion and effector function of alloreactive T cells. Thus, therapies aimed at specific subsets of NK cells may facilitate transplantation tolerance in settings of impaired T-cell function.
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MESH Headings
- Animals
- Antigens, Ly/immunology
- Antigens, Ly/metabolism
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/pathology
- Cell Proliferation
- Disease Models, Animal
- Genes, MHC Class I/immunology
- Graft Rejection/immunology
- Graft Rejection/metabolism
- Graft Rejection/pathology
- Heart Transplantation/immunology
- Immune Tolerance/immunology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/pathology
- Lymphocyte Subsets/immunology
- Lymphocyte Subsets/pathology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- NK Cell Lectin-Like Receptor Subfamily K
- Receptors, Immunologic/immunology
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Transplantation, Homologous
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Yi S, Zhou P, Chang L, Hendry J. 221 Radiosensitisation of tumour cells by the HIV-1 TAT protein. Radiother Oncol 2006. [DOI: 10.1016/s0167-8140(06)80698-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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255
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Lin CJ, Zhang HQ, Yang F, Ruan M, Liu ZH, Wu XK, Zhou P, Zhang CL, Zhang GL, An GP, Jia HM, Xu XX. Effects of Breakup of Weakly Bound Projectile and Neutron Transfer on Fusion Reactions. ACTA ACUST UNITED AC 2006. [DOI: 10.1063/1.2398820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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256
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Zhou P, Gautam S, Recht A. Factors Affecting Outcome for Young Women With Early Stage Invasive Breast Cancer Treated with Breast-Conserving Therapy (BCT). Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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257
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Vijayan S, Zhou P, Rajapaksha TW, Alegre ML, Peter ME. Transplanted islets from lpr mice are resistant to autoimmune destruction in a model of streptozotocin-induced type I diabetes. Apoptosis 2005; 10:725-30. [PMID: 16133864 DOI: 10.1007/s10495-005-0377-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mechanism by which beta-cells die during autoimmune diabetes has remained a subject of intense investigation. The loss of beta-cells in the disease is T cell mediated and thought to result from a number of different insults including apoptosis induction through the death receptor CD95. However, the role of CD95 in autoimmune diabetes, studied primarily in the non-obese diabetic (NOD) mouse model, has been controversial. We have used an alternative model of autoimmune diabetes triggered by repeated low doses of streptozotocin. In this model, islet grafts from C3H mice that carry the lpr mutation, and therefore lack the ability to undergo apoptosis through CD95-CD95L interaction, were completely protected when grafted in autoimmune diabetic mice despite periinsulitis (infiltration of T cells) which however did not progress to islet destruction. In contrast wild-type grafts were rapidly eliminated in autoimmune recipients. Our data provide strong support for a major role of CD95 in the destruction of islets in autoimmune mice.
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258
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Zhou P, Chen MH, McLeod D, Carroll PR, Moul JW, D’Amico AV. Predictors of prostate cancer-specific mortality following radical prostatectomy or radiation therapy. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.4548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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259
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Cohen A, Zhou P, Reich L, Fircanis S, Drake L, Hedvat C, Teruya-Feldstein J, Filippa D, Fleisher M, Comenzo R. Interim analysis of a phase II study of risk-adapted intravenous melphalan followed by adjuvant dexamethasone (D) and thalidomide (T) for newly diagnosed patients with systemic al amyloidosis (AL). Biol Blood Marrow Transplant 2005. [DOI: 10.1016/j.bbmt.2004.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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260
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Gupta S, Zhou P, Hassoun H, Kewalramani T, Reich L, Costello S, Drake L, Klimek V, Dhodapkar M, Teruya-Feldstein J, Hedvat C, Kalakonda N, Fleisher M, Filippa D, Qin J, Nimer SD, Comenzo RL. Hematopoietic stem cell mobilization with intravenous melphalan and G-CSF in patients with chemoresponsive multiple myeloma: report of a phase II trial. Bone Marrow Transplant 2005; 35:441-7. [PMID: 15640822 DOI: 10.1038/sj.bmt.1704779] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multiple myeloma (MM) is an incurable hematologic malignancy for which autologous hematopoietic stem cell transplantation (HCT) is a standard therapy. The optimal method of stem cell mobilization is not defined. We evaluated intravenous melphalan (60 mg/m2), the most effective agent for MM, and G-CSF (10 microg/kg/day) for mobilization. End points were safety, adequacy of CD34+ collections, MM response, and contamination of stem cell components (SCC). In total, 32 patients were mobilized. There were no deaths or significant bleeding episodes; 14 patients (44%) required hospitalization for neutropenic fever. Median days of grade 3 or 4 neutropenia or thrombocytopenia were 7 (2-20) and 8 (3-17). Median mobilization days, CD34+ cells/kg and total leukaphereses were 16 (12-30), 12.1 million (2.6-52.8), and 2 (1-5) respectively. Four patients (12.5 %) failed to achieve the target of 4 million CD34+ cells/kg in five leukaphereses. Reduction in myeloma was seen in 11 patients (34%) with 3 (9%) achieving complete response; 15 (47%) maintained prior responses. Estimated MM contamination per SCC (N=48) was 0.0009% (range 0-0.1) and 0.21 x 10(4) cells per kg (range 0-41.2). Increased contamination was associated with increased patient age. This strategy for mobilization is feasible, frequently requires hospitalization and transfusion, and controls disease in most patients.
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261
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Zhou P, Ng A, Silver B, Hua L, Mauch P. Radiation therapy for orbital lymphoma. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.07.514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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262
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Cohen AD, Zhou P, Xiao Q, Fleisher M, Kalakonda N, Akhurst T, Chitale DA, Moscowitz C, Dhodapkar MV, Teruya-Feldstein J, Filippa D, Comenzo RL. Systemic AL amyloidosis due to non-Hodgkin's lymphoma: an unusual clinicopathologic association. Br J Haematol 2004; 124:309-14. [PMID: 14717777 DOI: 10.1046/j.1365-2141.2003.04779.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Systemic AL amyloidosis (AL) is a disorder in which light chains form fibrillar deposits, leading to organ dysfunction and death. Rarely, AL has been associated with non-Hodgkin's lymphoma (NHL), although this association has not been well characterized. We report a series of six patients with AL associated with NHL, primarily lymphoplasmacytic lymphoma. Organ involvement was variable, with frequent bulky lymphadenopathy and visceral cavity deposits, but no cardiac involvement. Positron emission tomography scans were negative. Bone marrow and lymph node biopsies showed a mixed population of CD20+ lymphoid and CD138+ plasma cells. Serum free light chains were elevated, and correlated with response to therapy. Immunoglobulin light chain variable region (Ig VL) germline gene use was typical for AL, reflecting previously observed correlations between germline gene use and organ tropism. Five patients received rituximab-based therapies with two responses. Two patients underwent autologous stem cell transplantation with one complete haematological response. Four patients survive at 10-132 months from diagnosis. AL with NHL has distinctive clinical features but employs the same Ig VL gene repertoire as AL with clonal plasma cell dyscrasias. Serial serum free light chain levels are useful for tracking response to therapy. Treatments aimed at both lymphoid and plasma cell components appear warranted.
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263
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Yao YF, Zhang YM, Zhou P, Zhang B, Qiu WY, Tseng SCG. Therapeutic penetrating keratoplasty in severe fungal keratitis using cryopreserved donor corneas. Br J Ophthalmol 2003; 87:543-7. [PMID: 12714387 PMCID: PMC1771670 DOI: 10.1136/bjo.87.5.543] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To investigate whether cryopreserved donor cornea could be used for therapeutic penetrating keratoplasty (PKP) to eradicate the infection, obviate complications, and preserve anatomical integrity in severe fungal keratitis. METHODS In this retrospective, consecutive case series, 45 eyes of 45 patients with severe fungal keratitis, which exhibited anterior chamber collapse, corneal perforation, and/or large suppurative corneal infiltrate, received therapeutic PKP after removal of the infected corneal tissue, irrigation of the anterior chamber by 0.2% fluconazole solution, iris dissection of fibrinoid membrane, and iridectomy and therapeutic PKP using corneas cryopreserved at -20 degrees C. RESULTS Among 45 eyes, 39 eyes (86.7%) were successfully eradicated the fungal infection without recurrence and maintained their anatomical integrity without any complication. Four of 45 eyes (8.9%) showed postoperative rise of intraocular pressure, of which three were controlled with subsequent antiglaucoma surgeries, whereas one eye needed additional antiglaucoma medications. Two of 45 eyes (4.4%) were enucleated because of uncontrollable fungal infection and secondary retinal detachment, respectively. 23 eyes received subsequent optical PKP and, among them, 21 maintained clear corneal grafts and two suffered from graft failure due to allograft rejections. CONCLUSION Cryopreserved donor corneas are effective substitutes in therapeutic PKP to control severe fungal corneal infection and preserve the global integrity, and may offer additional advantages over conventional PKP in reducing allograft rejection, eradicating fungal infection during the postoperative period, and improving the success of optical PKP for visual rehabilitation.
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264
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Merger M, Viney JL, Borojevic R, Steele-Norwood D, Zhou P, Clark DA, Riddell R, Maric R, Podack ER, Croitoru K. Defining the roles of perforin, Fas/FasL, and tumour necrosis factor alpha in T cell induced mucosal damage in the mouse intestine. Gut 2002; 51:155-63. [PMID: 12117872 PMCID: PMC1773316 DOI: 10.1136/gut.51.2.155] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND AND AIMS Mucosal flattening and epithelial cell apoptosis are typical features of T cell induced inflammatory diseases of the bowel, such as coeliac disease and graft versus host disease. Mice injected with a T cell activating anti-CD3 antibody develop a severe diarrhoeal illness. We describe the histological features of this enteropathy and define the effector mechanisms involved in T cell induced mucosal injury in this in vivo model. METHODS Wild-type and genetically modified mice were injected with the anti-CD3 antibody 3C11 (50 microg). Changes in the murine intestine were characterised by light microscopy analysis and terminal uridine nick-end labelling (TUNEL) assay. The role of perforin, Fas/Fas ligand (FasL), tumour necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) in T cell induced mucosal damage was assessed using selected immunodeficient mouse strains. RESULTS T cell activation caused severe damage, including small intestinal mucosal flattening and apoptosis of crypt epithelial cells. Mucosal damage was unaltered in anti-CD3 treated mice lacking IFN-gamma, Fas, or TNF-alpha receptors. In mice lacking TNF-alpha receptors and Fas (TNF-R1xR2 lpr/lpr strain), enterocyte apoptosis was diminished but there was no significant reduction in tissue damage. Apoptosis and mucosal injury were significantly reduced in perforin knockout mice. Abrogation of both FasL and perforin (perforin KOxgld mice) further significantly reduced tissue damage and apoptotic bodies. CONCLUSIONS T cell induced mucosal injury is mediated by the combined effect of multiple pathways but predominantly by perforin. The redundancy of the mechanisms of tissue damage will have significant impact on therapeutic strategies aimed at specific and targeted inhibition of inflammatory processes.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Antigens, CD/genetics
- Apoptosis
- CD3 Complex/immunology
- Epithelium/pathology
- Fas Ligand Protein
- In Situ Nick-End Labeling
- Interferon-gamma/genetics
- Intestinal Mucosa/immunology
- Intestinal Mucosa/pathology
- Intestine, Small/immunology
- Lymphocyte Activation
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, SCID
- Models, Animal
- Perforin
- Pore Forming Cytotoxic Proteins
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type I
- Receptors, Tumor Necrosis Factor, Type II
- T-Lymphocytes/immunology
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/physiology
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265
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Zhou P, Chen X, Frisch HL, Zhu Z, Rider J, Wnek GE. Effect of molecular weight and molecular architecture of PMMA on the phase morphology of pseudo-IPN's of PCU/PMMA. Macromolecules 2002. [DOI: 10.1021/ma00052a041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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266
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Brown W, Konak C, Johnsen RM, Zhou P. Dynamic behavior in ternary polymer solutions. Concentration dependence of diffusion coefficients. Macromolecules 2002. [DOI: 10.1021/ma00205a035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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267
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Bonamartini-Corradi A, Battaglia LP, Rubenacker J, Willett RD, Grigereit TE, Zhou P, Drumheller JE. Structural, EPR, and magnetic characterization of bis(piperazinium) hexachlorocuprate-methanol and bis(1-methylpiperazinium) hexachlorocuprate. Inorg Chem 2002. [DOI: 10.1021/ic00044a032] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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268
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Liu Z, Yang H, Huang Z, Zhou P, Liu SJ. Degradation of aniline by newly isolated, extremely aniline-tolerant Delftia sp. AN3. Appl Microbiol Biotechnol 2002; 58:679-82. [PMID: 11956754 DOI: 10.1007/s00253-002-0933-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2001] [Accepted: 12/20/2001] [Indexed: 10/27/2022]
Abstract
A bacterial strain, AN3, which was able to use aniline or acetanilide as sole carbon, nitrogen and energy sources was isolated from activated sludge and identified as Delftiasp. AN3. This strain was capable of growing on concentrations of aniline up to 53.8 mM (5000 mg/l). Substituted anilines such as N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 4-methylaniline, 2-chloroaniline, 3-chloroaniline, o-aminoaniline, m-aminoaniline, p-aminoaniline, and sulfanilic acid did not support the growth of strain AN3. The optimal temperature and pH for growth and degradation of aniline were 30 degrees C and 7.0, respectively. The activities of aniline dioxygenase, catechol 2,3-dioxygenase and other enzymes involved in aniline degradation were determined, and results indicated that all of them were inducible. The K (m) and V (max) of aniline dioxygenase were 0.29 mM and 0.043 mmol/mg protein/min, respectively. The K (m) and V (max) of catechol 2, 3-dioxygenase for catechol were 0.016 mM and 0.015 mmol/mg protein/min, respectively. Based on the results obtained, a pathway for the degradation of aniline by Delftiasp. AN3 was proposed. The importance of the strain to the operation of municipal wastewater treatment plants is discussed.
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269
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Chen X, Zhang Y, Douglas L, Zhou P. UV-damaged DNA-binding proteins are targets of CUL-4A-mediated ubiquitination and degradation. J Biol Chem 2001; 276:48175-82. [PMID: 11673459 DOI: 10.1074/jbc.m106808200] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cul-4A, which encodes a member of the cullin family subunit of ubiquitin-protein ligases, is expressed at abnormally high levels in many tumor cells. CUL-4A can physically associate with the damaged DNA-binding protein (DDB), which is composed of two subunits, p125 and p48. DDB binds specifically to UV-damaged DNA and is believed to play a role in DNA repair. We report here that CUL-4A stimulates degradation of p48 through the ubiquitin-proteasome pathway, resulting in an overall decrease in UV-damaged DNA binding activity. The R273H mutant of p48 identified from a xeroderma pigmentosium (group E) patient is not subjected to CUL-4A-mediated proteolysis, consistent with its inability to bind CUL-4A. p125 is also an unstable protein, and its ubiquitination is stimulated by CUL-4A. However, the abundance of p125 is not dramatically altered by Cul-4A overexpression. UV irradiation inhibits p125 degradation, which is temporally coupled to the UV-induced translocation of p125 from the cytoplasm into the nucleus. CUL-4A is localized primarily in the cytoplasm. These findings identify DDB subunits as the first substrates of the CUL-4A ubiquitination machinery and suggest that abnormal expression of Cul-4A results in reduced p48 levels, thus impairing the ability of DDB in lesion recognition and DNA repair in tumor cells.
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270
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Li G, Zhou P, Shao Z, Xie X, Chen X, Wang H, Chunyu L, Yu T. The natural silk spinning process. A nucleation-dependent aggregation mechanism? EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:6600-6. [PMID: 11737214 DOI: 10.1046/j.0014-2956.2001.02614.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The spinning mechanism of natural silk has been an open issue. In this study, both the conformation transition from random coil to beta sheet and the beta sheet aggregation growth of silk fibroin are identified in the B. mori regenerated silk fibroin aqueous solution by circular dichroism (CD) spectroscopy. A nucleation-dependent aggregation mechanism, similar to that found in prion protein, amyloid beta (Abeta) protein, and alpha-synuclein protein with the conformation transition from a soluble protein to a neurotoxic, insoluble beta sheet containing aggregate, is a novel suggestion for the silk spinning process. We present evidence that two steps are involved in this mechanism: (a) nucleation, a rate-limiting step involving the conversion of the soluble random coil to insoluble beta sheet and subsequently a series of thermodynamically unfavorable association of beta sheet unit, i.e. the formation of a nucleus or seed; (b) once the nucleus forms, further growth of the beta sheet unit becomes thermodynamically favorable, resulting a rapid extension of beta sheet aggregation. The aggregation growth follows a first order kinetic process with respect to the random coil fibroin concentration. The increase of temperature accelerates the beta sheet aggregation growth if the beta sheet seed is introduced into the random coil fibroin solution. This work enhances our understanding of the natural silk spinning process in vivo.
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271
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Lu J, Rakhely G, Kovacs KL, Xiao C, Zhou P. [Identification and cloning of partial mbh2 gene cluster of hyperthermophile Aquifex pyrophilus]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2001; 41:674-9. [PMID: 12552822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
A 0.8 kb fragment of mbhS2 gene of Aquifex pyrophilus was obtained by PCR with designed primers basing mbhS2 gene of A. aeolicus. It showed 85% homology with the corresponding region of A. aeolicus. Using it as probe, a 5.0 kb Nco I fragment was fished out from the partial genomic library of A. pyrophilus. Then this fragment was cloned, subcloned and sequenced. The result revealed that the fragment contains the full length gene for the mbhS2, the gene orf1 and the first 366 bp of orf2. Comparison with mbhS2 and orf963 of A. aeolicus shows 81% and 60% homologies in amino acid sequence, respectively.
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273
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Zhou Z, Zhang C, Chen J, Zhou P. [Serapharmacological effect of kangxian ruangan granula on the proliferation of hepatic stellate cells]. ZHONG YAO CAI = ZHONGYAOCAI = JOURNAL OF CHINESE MEDICINAL MATERIALS 2001; 24:809-11. [PMID: 15575164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVE To investigate the antifibrotic mechanism of kangxian ruangan granula (KXRGG) at cellular level. METHOD HSC were isolated from the normal rats by enzyme digestion and density gradient centrifugation, cultured, identified and subcultured. The medicated sera were prepared to incubated with the subcultured HSC. Sodium chloride sera and colchicines sera were taken as control groups. HSC viability was observed by 3H-proline; cell proliferation was measured with 3H-TdR incorporation and MTT colorimetric assay. RESULT KXRGG medicated serum had no effect on the cellular shape and elevated 3H-proline incorporation (P < 0.01). Drug serum obviously inhibited 3H-TdR incorporation and MTT transformation (P < 0.01), and the latter had a drug concentration-dependent tendency. CONCLUSIONS KXRGG can elevate cellular viability and has no toxic effect. The formula can inhibit the proliferation of HSC, which may be one of the cellular mechanisms of its antifibrotic action.
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274
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Guo Z, Wang J, Meng L, Wu Q, Kim O, Hart J, He G, Zhou P, Thistlethwaite JR, Alegre ML, Fu YX, Newell KA. Cutting edge: membrane lymphotoxin regulates CD8(+) T cell-mediated intestinal allograft rejection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:4796-800. [PMID: 11673481 DOI: 10.4049/jimmunol.167.9.4796] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Blocking the CD28/B7 and/or CD154/CD40 costimulatory pathways promotes long-term allograft survival in many transplant models where CD4(+) T cells are necessary for rejection. When CD8(+) T cells are sufficient to mediate rejection, these approaches fail, resulting in costimulation blockade-resistant rejection. To address this problem we examined the role of lymphotoxin-related molecules in CD8(+) T cell-mediated rejection of murine intestinal allografts. Targeting membrane lymphotoxin by means of a fusion protein, mAb, or genetic mutation inhibited rejection of intestinal allografts by CD8(+) T cells. This effect was associated with decreased monokine induced by IFN-gamma (Mig) and secondary lymphoid chemokine (SLC) gene expression within allografts and spleens respectively. Blocking membrane lymphotoxin did not inhibit rejection mediated by CD4(+) T cells. Combining disruption of membrane lymphotoxin and treatment with CTLA4-Ig inhibited rejection in wild-type mice. These data demonstrate that membrane lymphotoxin is an important regulatory molecule for CD8(+) T cells mediating rejection and suggest a strategy to avoid costimulation blockade-resistant rejection.
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275
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Cases S, Stone SJ, Zhou P, Yen E, Tow B, Lardizabal KD, Voelker T, Farese RV. Cloning of DGAT2, a second mammalian diacylglycerol acyltransferase, and related family members. J Biol Chem 2001; 276:38870-6. [PMID: 11481335 DOI: 10.1074/jbc.m106219200] [Citation(s) in RCA: 584] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Studies involving the cloning and disruption of the gene for acyl-CoA:diacylglycerol acyltransferase (DGAT) have shown that alternative mechanisms exist for triglyceride synthesis. In this study, we cloned and characterized a second mammalian DGAT, DGAT2, which was identified by its homology to a DGAT in the fungus Mortierella rammaniana. DGAT2 is a member of a gene family that has no homology with DGAT1 and includes several mouse and human homologues that are candidates for additional DGAT genes. The expression of DGAT2 in insect cells stimulated triglyceride synthesis 6-fold in assays with cellular membranes, and DGAT2 activity was dependent on the presence of fatty acyl-CoA and diacylglycerol, indicating that this protein is a DGAT. Activity was not observed for acyl acceptors other than diacylglycerol. DGAT2 activity was inhibited by a high concentration (100 mm) of MgCl(2) in an in vitro assay, a characteristic that distinguishes DGAT2 from DGAT1. DGAT2 is expressed in many tissues with high expression levels in the liver and white adipose tissue, suggesting that it may play a significant role in mammalian triglyceride metabolism.
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