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1.
J Thromb Haemost ; 16(9): 1843-1856, 2018 09.
Article in English | MEDLINE | ID: mdl-29953749

ABSTRACT

Essentials The pathogenesis of immune thrombocytopenia (ITP) has not been fully clarified. We analyzed the role of anti-αvß3 autoantibody in the pathogenesis of ITP in patients. Anti-αvß3 autoantibody impeded megakaryocyte migration and adhesion to the vascular niche. Anti-αv ß3 autoantibody potentially contributes to the pathogenesis of refractory ITP. SUMMARY: Background The pathogenesis of immune thrombocytopenia (ITP) has not been fully clarified. Anti-αvß3 integrin autoantibody is detected in chronic ITP patients, but its contribution to ITP is still unclear. Objectives To clarify the potential role of anti-αvß3 integrin autoantibody in chronic ITP and the related mechanism. Methods Relationship between levels of anti-αvß3 autoantibody and platelets in chronic ITP patients was evaluated. The influence of anti-αvß3 antibody on megakaryocyte (MK) survival, differentiation, migration and adhesion was assessed, and the associated signal pathways were investigated. Platelet recovery and MKs' distribution were observed in an ITP mouse model pretreated with different antibodies. Result In this study, we showed that the anti-αvß3 autoantibody usually coexists with anti-αIIbß3 autoantibody in chronic ITP patients, and patients with both autoantibodies have lower platelets. In in vitro studies, we showed that the anti-αvß3 antibody had no significant effect on the survival and proliferation of MKs, whereas it decreased formations of proplatelet significantly. Anti-αvß3 antibody impeded stromal cell derived facor-1 alpha (SDF-1α)- mediated migration and inhibited the phosphorylation of protein kinase B. Anti-αvß3 antibody significantly inhibited MKs' adhesion to endothelial cells and Fibrogen. The phosphorylation of focal adhesion kinase and proto-oncogene tyrosine-protein kinase Src induced by adhesion was inhibited when MKs were pretreated with anti-αvß3 antibody. In in vivo studies, we showed that injection with anti-αv antibody delayed platelet recovery in a mouse model of ITP. Conclusions These findings demonstrate that the autoantibody against integrin αv ß3 may aggravate thrombocytopenia in ITP patients by impeding MK migration and adhesion to the vascular niche, which provides new insights into the pathogenesis of ITP.


Subject(s)
Autoantibodies/immunology , Autoantigens/immunology , Integrin alphaVbeta3/immunology , Megakaryocytes/immunology , Purpura, Thrombocytopenic, Idiopathic/immunology , Adolescent , Adult , Aged , Animals , Cell Adhesion , Cell Movement , Cells, Cultured , Chemokine CXCL12/metabolism , Endothelial Cells/metabolism , Female , Fetal Blood/cytology , Humans , Male , Megakaryocytes/cytology , Mice , Mice, Inbred BALB C , Middle Aged , Phosphorylation , Platelet Count , Platelet Membrane Glycoprotein IIb/immunology , Protein Kinases/metabolism , Protein Processing, Post-Translational , Proto-Oncogene Mas , Proto-Oncogene Proteins c-akt/metabolism , Purpura, Thrombocytopenic, Idiopathic/blood , Stromal Cells/metabolism , Thrombopoiesis , Young Adult
2.
Oncogene ; 37(1): 116-127, 2018 01 04.
Article in English | MEDLINE | ID: mdl-28892050

ABSTRACT

Aberrant protein glycosylation could be a distinct surface-marker of cancer cells that influences cancer progression and metastasis because glycosylation can regulate membrane protein folding which alters receptor activation and changes epitope exposure for antibody (Ab) recognition. Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), a glycophosphoinositol-anchored protein, is a heavily glycosylated tumor antigen. However, the clinical significance and biological effect of CEACAM6 glycosylation has not been addressed in cancers. We recently developed an anti-CEACAM6 Ab (TMU) from an immune llama library which can be engineered to a single-domain (sd)Ab or a heavy-chain (HC)Ab. The TMU HCAb specifically recognized glycosylated CEACAM6 compared to the conventional antibodies. Using the TMU HCAb, we found that glycosylated CEACAM6 was a tumor marker associated with recurrence in early-stage OSCC (oral squamous cell carcinoma) patients. CEACAM6 promoted OSCC cell invasion, migration, cytoskeletal rearrangement, and metastasis via interaction with epidermal growth factor (EGF) receptor (EGFR) and enhancing EGFR activation, clustering and intracellular signaling cascades. These functions were modulated by N-acetylglucosaminyltransferase 5 (MGAT5) which mediated N-glycosylation at Asn256 (N256) of CEACAM6. Finally, the TMU sdAb and HCAb treatment inhibited the migration, invasion and EGF-induced signaling in CEACAM6-overexpressing cells. In conclusion, the complex N-glycosylation of CEACAM6 is critical for EGFR signaling of OSCC invasion and metastasis. Targeting glycosylated CEACAM6 with the TMU sdAb or TMU HCAb could be a feasible therapy for OSCC.


Subject(s)
Antigens, CD/metabolism , Carcinoma, Squamous Cell/pathology , Cell Adhesion Molecules/metabolism , ErbB Receptors/metabolism , Lung Neoplasms/pathology , Mouth Neoplasms/pathology , Neoplasm Recurrence, Local/pathology , Adult , Animals , Antigens, CD/genetics , Asparagine/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/secondary , Cell Adhesion Molecules/genetics , Cell Line, Tumor , Cell Movement , ErbB Receptors/genetics , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolism , Glycosylation , Humans , Lung Neoplasms/secondary , Male , Mice , Mice, SCID , N-Acetylglucosaminyltransferases/genetics , N-Acetylglucosaminyltransferases/metabolism , Neoplasm Invasiveness/pathology , Neoplasm Staging , RNA, Small Interfering/metabolism , Signal Transduction , Xenograft Model Antitumor Assays
3.
Crisis ; 38(4): 269-277, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28337929

ABSTRACT

BACKGROUND: The use of the helium suicide method has been increasing in popularity in Hong Kong since 2012. We have learned a valuable lesson in curbing the spread of charcoal burning (CB) suicide in the past 15 years and hope to prevent the helium suicide method from taking off in the community. AIMS: To document what actions have been taken to contain the spread of the helium suicide method and review the preliminary impact of these actions. METHOD: We adopted a public health approach by engaging stakeholders from multiple sectors, including the police force, the fire services department, coroners, pathologists, mass media, and online media outlets. RESULTS: A monitoring system was established by compiling data extracted from news reports, coroners' reports, and police investigations. Risk and protective factors were identified. Intervention strategies were developed to strengthen protective factors and minimize risk factors. This novel suicide method has not spread as rapidly as the CB suicide method. The preliminary outcomes suggest our actions to be effective. LIMITATIONS: The count of helium suicides in 2015 might be low. The impacts of the interventions are only estimated and require additional empirical verifications. CONCLUSION: The public health approach of engaging multiple partners in the early phase of a potential epidemic can be a good guide to meeting the challenges posed by any new suicide methods that emerge in the future.


Subject(s)
Helium/toxicity , Public Health , Suicide Prevention , Epidemiological Monitoring , Health Education , Health Promotion , Hong Kong/epidemiology , Humans , Internet , Mass Media , Protective Factors , Public Service Announcements as Topic , Risk Factors , Suicide/statistics & numerical data
4.
Mol Psychiatry ; 16(8): 848-59, 2011 Aug.
Article in English | MEDLINE | ID: mdl-20585325

ABSTRACT

Little is known about the biological mechanisms underpinning the pathology of schizophrenia. We have analysed the proteome of stimulated and unstimulated peripheral blood mononuclear cells (PBMCs) from schizophrenia patients and controls as a potential model of altered cellular signaling using liquid-chromatography mass spectrometry proteomic profiling. PBMCs from patients and controls were stimulated for 72 h in vitro using staphylococcal enterotoxin B. In total, 18 differentially expressed proteins between first-onset, antipsychotic-naive patients and controls in the unstimulated and stimulated conditions were identified. Remarkably, eight of these proteins were associated with the glycolytic pathway and patient-control differences were more prominent in stimulated compared with unstimulated PBMCs. None of these proteins were altered in chronically ill antipsychotic-treated patients. Non-linear multivariate statistical analysis showed that small subsets of these proteins could be used as a signal for distinguishing first-onset patients from controls with high precision. Functional analysis of PBMCs did not reveal any difference in the glycolytic rate between patients and controls despite increased levels of lactate and the glucose transporter-1, and decreased levels of the insulin receptor in patients. In addition, subjects showed increased serum levels of insulin, consistent with the idea that some schizophrenia patients are insulin resistant. These results show that schizophrenia patients respond differently to PBMC activation and this is manifested at disease onset and may be modulated by antipsychotic treatment. The glycolytic protein signature associated with this effect could therefore be of diagnostic and prognostic value. Moreover, these results highlight the importance of using cells for functional discovery and show that it may not be sufficient to measure protein expression levels in static states.


Subject(s)
Antipsychotic Agents/administration & dosage , Blood Glucose/metabolism , Leukocytes, Mononuclear/metabolism , Schizophrenia/metabolism , Adult , Antipsychotic Agents/therapeutic use , Enterotoxins/pharmacology , Female , Glucose Transporter Type 1/blood , Hexokinase/metabolism , Humans , Insulin/blood , Lactic Acid/blood , Leukocytes, Mononuclear/drug effects , Male , Proteome/metabolism , Proteomics/methods , Receptor, Insulin/blood , Schizophrenia/blood , Schizophrenia/drug therapy
5.
J Int Med Res ; 36(6): 1214-9, 2008.
Article in English | MEDLINE | ID: mdl-19094429

ABSTRACT

Autoimmune diseases have been implicated in the development of intrinsic asthma, however little data are available on the role of autoimmunity in the pathogenesis of asthma. The purpose of this study was to investigate circulating autoantibodies against the high-affinity receptor for immunoglobulin E, FcepsilonRI, in patients with asthma. Seventy-eight patients with asthma and 32 healthy control subjects were included. All individuals were tested using a triple-staining flow cytometry-based basophil activation test (BAT) for the potential presence of autoantibodies against FcepsilonRI. Of the 78 asthma patients, 29 (37.2%) had a positive BAT result, indicating that their serum was able to activate basophils, compared with only four (12.5%) of the control group, a statistically significant between-group difference. These data suggest that some asthma patients have aberrant anti-FcepsilonRI autoantibodies, which implies that autoimmunity may be one factor involved in the pathogenesis of intrinsic asthma.


Subject(s)
Asthma/immunology , Autoantibodies/immunology , Autoimmunity/immunology , Basophils/immunology , Flow Cytometry/methods , Receptors, IgE/immunology , Antigens, CD/metabolism , Asthma/metabolism , Autoantibodies/blood , Basophil Degranulation Test , Basophils/metabolism , Humans , Immunoglobulin E/immunology , Platelet Membrane Glycoproteins/metabolism , Tetraspanin 30
6.
Dis Aquat Organ ; 65(2): 91-8, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16060261

ABSTRACT

In order to obtain an in vitro system for studying the mechanism of persistent infection of fish nodavirus, a novel cell line (BB) was established from the brain tissue of a barramundi, Lates calcarifer, which had survived viral nervous necrosis disease. The cell line has been subcultured > 100 times. The persistence of fish nodavirus designated as barramundi brain nervous necrosis virus (BBNNV) in the BB cells was demonstrated by: (1) the detection of the infectious virus in the culture supernatants, (2) the detection of NNV nucleic acids extracted from the BB cells, (3) the positive result of immunochemical staining using an NNV-specific monoclonal antibody and (4) their resistance to infection by another fish nodavirus grouper NNV (GNNV). No temperature-sensitive mutants were detected in the culture supernatant of the BB cells. Neither truncated genome (RNA1 or RNA2) nor smaller coat protein was found in the purified BBNNV particles, suggesting that defective interfering particles were unlikely to be important in the NNV-persistent infection in the BB cells. The result of the neutralization test indicated that the 5 antigenic determinants, recognized by GNNV-specific neutralizing antibodies, also existed on the coat protein of BBNNV. The BB cell line is the first cell line reported to be persistently infected with NNV, and would be a useful model for understanding the mechanisms of NNV-persistent infection in vitro and in vivo.


Subject(s)
Brain/virology , Fish Diseases/virology , Nodaviridae/isolation & purification , Perciformes , RNA Virus Infections/veterinary , Animals , Antibodies, Monoclonal , Blotting, Western/veterinary , Cell Line , DNA Primers , Electrophoresis, Polyacrylamide Gel/veterinary , Immunohistochemistry/veterinary , Neutralization Tests/veterinary , Nodaviridae/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Viral Proteins/genetics
7.
J Gen Virol ; 83(Pt 10): 2469-2474, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12237429

ABSTRACT

Interference of the life cycle of grouper nervous necrosis virus (GNNV), a member of the Nodaviridae, genus Betanodavirus, by snakehead retrovirus (SnRV) has been studied in vitro. SGF-1, a new fish cell line that is persistently infected with SnRV, was induced by inoculating SnRV into the grouper fin cell line GF-1. Culture supernatants and cell pellets from both GNNV-infected SGF-1 and GF-1 cells were collected and employed for virus productivity analysis. The yields of GNNV RNA and capsid protein in GNNV-infected SGF-1 cells were similar to those in GNNV-infected GF-1 cells. However, when GF-1 cells were used for titration, the titre of the culture supernatant from GNNV-infected SGF-1 cells was much higher than that from GNNV-infected GF-1 cells. The titration result suggested that SnRV enhanced the infection or cytopathic effect (CPE) of GNNV during GNNV and SnRV coinfection of the GF-1 cell titration system, although SnRV cannot induce any CPE in GF-1 cells alone, nor can it increase the yield of GNNV after GNNV superinfection of SGF-1 cells. Moreover, GNNV cDNA was detected in both the pellet and the supernatant from GNNV-infected SGF-1 cells. This result indicated that SnRV reverse-transcribed the GNNV single-stranded genomic RNA into cDNA during GNNV superinfection of SGF-1 cells and created a new cDNA stage in the life cycle of the fish nodavirus.


Subject(s)
Fishes/virology , Nodaviridae/physiology , Retroviridae/physiology , Viral Interference , Animals , Antigens, Viral/analysis , Blotting, Western/methods , Cell Line , Culture Media , Cytopathogenic Effect, Viral , Fish Diseases/virology , Nodaviridae/genetics , RNA Virus Infections/virology , RNA, Viral/analysis
8.
Arch Pharm (Weinheim) ; 334(5): 173-6, 2001 May.
Article in English | MEDLINE | ID: mdl-11413824

ABSTRACT

A series of diquaternary dipiperazinium salts containing dithiocarboxyl groups 6a-f and 9 were synthesized and evaluated for their analgesic and sedative activities. The result showed that the presence of two quaternary ammonium cations and the distance between them are very important for the activities of the salts. Compound 6b exhibited the best activities (at dose 2 mg/kg, analgesic, 57%; sedative, 59%) among compounds 6a-f. Compound 9 not only showed the most potent analgesic (85.4%, dose 1 mg/kg) and sedative (93.1%, dose 1 mg/kg) activities, but also exhibited anticancer activity against KB (68.7%, dose 10 microM).


Subject(s)
Analgesics/chemical synthesis , Hypnotics and Sedatives/chemical synthesis , Analgesics/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Cell Division/drug effects , Dimerization , Drug Evaluation, Preclinical , Female , Humans , Hypnotics and Sedatives/pharmacology , KB Cells/drug effects , Male , Mice , Piperazines/chemical synthesis , Piperazines/pharmacology , Quaternary Ammonium Compounds/chemical synthesis , Quaternary Ammonium Compounds/pharmacology , Structure-Activity Relationship
9.
Zhongguo Zhong Yao Za Zhi ; 26(12): 837-9, 2001 Dec.
Article in Chinese | MEDLINE | ID: mdl-12776331

ABSTRACT

OBJECTIVE: To study the chemical constituents of Carduus crispus. METHOD: Using chromatographic methods to isolate compounds and using chemical and spectral methods to elucidate the structures of the isolated compounds. RESULT: Eight compounds were elucidated as beta-amyrin palmitate, taraxastery acetate, luteolin-7-O-alpha-L-rhamanopyranosyl-(1-->2)-beta-D-glucopyranoside, luteolin-7-O-beta-D-glucopyranoside, triacontanic acid, beta-sitosterol, stigmasterol and stigmast-7-en-3 beta-ol. CONCLUSION: All the compounds were obtained from this plant for the first time.


Subject(s)
Carduus/chemistry , Flavonoids/isolation & purification , Glucosides/isolation & purification , Luteolin , Plants, Medicinal/chemistry , Sterols/isolation & purification , Triterpenes/isolation & purification , Flavonoids/chemistry , Glucosides/chemistry , Oleanolic Acid/analogs & derivatives , Sterols/chemistry , Triterpenes/chemistry
11.
Sheng Li Xue Bao ; 53(5): 375-9, 2001 Oct.
Article in Chinese | MEDLINE | ID: mdl-11833422

ABSTRACT

To observe the changes in aldosterone binding activity of kidney cytosols after pathological stress in rats and the regulation, binding capacity (Rt) and apparent dissociation constant (Kd) of aldosterone binding activity of kidney cytosols in normal, low-degree or heavy-degree scalded rats were measured by radioligand binding assay using [3H]aldosterone as the ligand. Changes in Rt and Kd of aldosterone binding activity were observed after injection of anti-rat TNF alpha and IL-1 beta antibodies, alpha-melanocyte-stimulating hormone (alpha-MSH) and KPV peptide (Ac-D-Lys-L-Pro-D-Val). The results indicated that there were two types of aldosterone binding activities in kidney cytosol with different Rt and Kd, and the Rt of heavy-degree scalded rats (Rt1: 22.4 +/- 5.4 fmol/mg pro, Rt2: 196.3 +/- 32.5 fmol/mg pro) was lower than that of the control group (Rt1: 41.6 +/- 7.2 fmol/mg pro, Rt2: 317.6 +/- 70.0 fmol/mg pro) (P < 0.01; P < 0.01); while the Rt of low-degree scalded rats (Rt1: 41.4 +/- 5.0 fmol/mg pro, Rt2: 314.8 +/- 45.7 fmol/mg pro) was not significantly different from that of the control group (P > 0.05; P > 0.05). Injection of anti-rat TNF alpha and IL-1 beta antibodies, alpha-MSH and KPV prevented Rt of aldosterone binding activity from decrease in kidney cytosol of rats with heavy-degree scald. These findings suggest that aldosterone binding activity may be down-regulated in heavy-degree scalded rats, but it may be reversed by injection of anti-rat TNF alpha and IL-1 beta antibodies, alpha-MSH and KPV.


Subject(s)
Aldosterone/metabolism , Burns/metabolism , Cytosol/metabolism , Kidney/metabolism , Animals , In Vitro Techniques , Kidney/cytology , Male , Rats , Rats, Wistar , Stress, Physiological/metabolism
12.
Yao Xue Xue Bao ; 36(3): 185-7, 2001 Mar.
Article in Chinese | MEDLINE | ID: mdl-12580084

ABSTRACT

AIM: To synthesize piperazine derivatives and screen anti-tumor compounds with higher activity and lower toxicity. METHODS: Selecting 1,4-bis(3-bromopropionyl)piperazine as leading compound, a series of 1,4-bis[3-(amino-dithiocarboxy)propionyl] piperazine derivatives (4a-j) were synthesized through the use of aminodithiocarboxylate. All the synthetic compounds (4a-j) were tested for their anti-tumor activity against eight kinds of tumor cells. RESULTS: Compounds (4a-j) are new compounds, among them, compounds 4c, 4d and 4e showed anti-tumor activity against HL-60. The inhibition of compounds 4c, 4d and 4e against HL-60 are 44%, 90% and 70% respectively, at the concentration of 10 mumol.L-1. However, the inhibition of the other kinds of anti-tumor cells are not distinctive. CONCLUSION: These results suggest that this may be one of the effective routes to improve the anti-tumor activity and reduce the toxicity of 1,4-bis(3-bromopropionyl)piperazine.


Subject(s)
Antineoplastic Agents/chemical synthesis , Piperazines/chemical synthesis , Antineoplastic Agents/pharmacology , HL-60 Cells/drug effects , Humans , Piperazines/pharmacology , Tumor Cells, Cultured/drug effects
13.
J Asian Nat Prod Res ; 2(2): 81-6, 2000.
Article in English | MEDLINE | ID: mdl-11252682

ABSTRACT

A new triterpenoid, 2alpha-,3beta,-,19alpha-trihydroxy-urs-12-ene-24,28-dioic acid (1), along with two known compounds. 3beta-acetoxy-urs-12-ene-11-one (2) and vomifoliol (3), was isolated from stems of Stelmatocryprton khasianum for the first time. Their structures were elucidated on the basis of chemical and spectroscopic methods.


Subject(s)
Drugs, Chinese Herbal/chemistry , Plant Extracts/isolation & purification , Triterpenes/isolation & purification , Magnetic Resonance Spectroscopy , Models, Chemical , Triterpenes/chemistry
14.
Zhongguo Zhong Yao Za Zhi ; 25(2): 101-3, 2000 Feb.
Article in Chinese | MEDLINE | ID: mdl-12212068

ABSTRACT

OBJECTIVE: To study the chemical constituents of Stelmatocrypton khasinum. METHOD: Using chromatographic methods to isolate compounds from S. khasinum and chemical and spectral methods to elucidate their structures. RESULT: Eight compounds, cleomiscosin A(1), 4-methoxy salicylicaldehyde(2), vanillin(3), isovanillin(4), 4-methoxy salicylic acid(5), isovanillic acid(6), 2,4-dihydroxy-benzoic acid(7) and 4-hydroxy-benzoic acid(8) were isolated from the stem of S. khasianum. CONCLUSION: Except compound 2, all the compounds were obtained from this plant for the first time.


Subject(s)
Apocynaceae/chemistry , Dioxanes/isolation & purification , Plants, Medicinal/chemistry , Benzaldehydes/chemistry , Benzaldehydes/isolation & purification , Coumarins , Dioxanes/chemistry , Molecular Structure
15.
Zhongguo Zhong Yao Za Zhi ; 25(5): 284-6, 2000 May.
Article in Chinese | MEDLINE | ID: mdl-12512449

ABSTRACT

OBJECTIVE: To separate the constituents from Eucommia ulmoides. METHOD: The constituents were separated by the repeated chromatography and identified by spectral methods. RESULT: The seven compounds were obtained, which were kaempferol(1), quercetin(2), astragalin(3), hirsutin(4), rutin(5), 3,4-dihydrobenzonic acid(6), ethyl glucopyranoside(7). CONCLUSION: Compounds 3-7 were obtained from leaves of E. ulmoides for the first time.


Subject(s)
Eucommiaceae/chemistry , Flavonoids/isolation & purification , Kaempferols , Plants, Medicinal/chemistry , Alkaloids/chemistry , Alkaloids/isolation & purification , Flavonoids/chemistry , Plant Leaves/chemistry , Rutin/chemistry , Rutin/isolation & purification
16.
J Neuroimaging ; 7(4): 250-1, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9344011

ABSTRACT

Acute bilateral infarcts in the territory of the posterior inferior cerebellum artery are rare and poorly documented in the literature. Thus, this report describes the clinical course and outcome in 3 patients. Although one was associated with coronary artery bypass surgery, the etiology was not known. Despite large territorial infarcts, the patients recovered to ambulation with minimal assistance.


Subject(s)
Cerebellum/blood supply , Cerebral Infarction/diagnosis , Acute Disease , Adult , Aged , Aged, 80 and over , Arteries , Cerebral Angiography , Cerebral Infarction/physiopathology , Cerebral Infarction/therapy , Coronary Artery Bypass , Female , Follow-Up Studies , Humans , Hydrocephalus/surgery , Magnetic Resonance Imaging , Male , Tomography, X-Ray Computed , Treatment Outcome , Ventriculostomy
18.
World J Gastroenterol ; 3(2): 75-7, 1997 Jun 15.
Article in English | MEDLINE | ID: mdl-27041944

ABSTRACT

AIM: To investigate the effects of DNA repair induced by DNA polymerase ß in hepatoma cells after γ-ray irradiation. METHODS: Cell nuclei were prepared from mouse model (SMMC LTNM), in which human hepatoma cells are transplanted on nude mice. The nuclei were then irradiated with (60)Co-γ rays at different dose levels or dose rates. A selective inhibitor test was then used to detect the effects of the radiation on DNA repair using N-ethylmaleimide (NEM) and ddTTP as selective inhibitors to DNA polymerases γ and ß respectively. RESULTS: (3)H-TTP incorporation into irradiated nuclei or calf thymus DNA was significantly higher than that the rate at which it is incorporated into non-irradiated nuclei when either DNA polymerase ß or γ was inhibited. When both NEM and ddTTP are present, the (3)H-TTP incorporation in irradiated DNA was not significantly different from the non-irradiated nuclei. Furthermore, (3)H-TTP incorporation into DNA of SMMC-LTNM hepatoma nuclei was higher than that of normal hepatocyte nuclei (P < 0.01). This suggests that DNA repair induced by DNA polymerase ß was more active in hepatoma cell nuclei than in normal hepatocyte nuclei. CONCLUSION: DNA polymerase ß may be more responsive to DNA damage in some tumor cells than that in normal cells, which may facilitate the cells to repair DNA damages from radiation more efficiently.

19.
J Neurosurg ; 81(3): 453-8, 1994 Sep.
Article in English | MEDLINE | ID: mdl-8057154

ABSTRACT

Extreme lateral disc herniations are increasingly recognized as a cause of lumbar nerve root compression syndromes. This disorder often presents major diagnostic and therapeutic challenges, especially in the presence of multiple degenerative changes and chronic back pain in elderly patients. The authors describe two patients with presentations and findings that have not been previously described in the literature. Both patients had histories of upper lumbar back and leg pain. Degenerative spine disease, gaseous degeneration of the intervertebral discs, and epidural gas in the lateral recesses were noted on imaging studies. However, because both patients had undergone prior epidural diagnostic and therapeutic procedures, the epidural gas in the lateral recesses could be attributed either to gaseous disc degeneration or to the previous intraspinal procedures. One patient was found to have a large, far lateral extruded disc fragment that contained air. The nerve root in the second patient was impaled by an unusual combination of a small extruded disc fragment as well as an air-filled sac that was surrounded by the walled-off fragment's capsule and which freely communicated with the gaseous degenerated disc space. The suspected mechanism of root compression is illustrated and discussed. The possibility of disc herniation should be seriously considered in cases of nerve root compression in which epidural gas is present, especially those associated with gaseous degenerated discs.


Subject(s)
Gases , Intervertebral Disc Displacement/diagnosis , Lumbar Vertebrae , Nerve Compression Syndromes/etiology , Spinal Nerve Roots , Aged , Aged, 80 and over , Epidural Space , Humans , Intervertebral Disc Displacement/complications , Male
20.
Neurosurgery ; 34(4): 590-5; discussion 596, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8008155

ABSTRACT

Meningeal and cortical biopsies were evaluated in 37 patients (25 men and 12 women; mean age, 54 yr) who had chronic meningitis of an unknown cause between 1985 and 1993 (the era of magnetic resonance imaging). Magnetic resonance imaging with gadolinium contrast was the most useful diagnostic imaging technique, demonstrating meningeal enhancement in 15 of 32 patients (47%). Only 2 of 32 (6%) computed tomographic scans revealed enhancement. A definitive diagnosis was made in 16 of 41 biopsies (39%), but in cases where enhancement was present on either magnetic resonance imaging or computed tomography, a diagnosis was obtained in 80% (12 of 15 cases). Only 2 of 22 biopsies (9%) from nonenhancing regions were diagnostic. Although the locations of enhancement were distributed evenly, biopsies through suboccipital and pterional craniotomies gave the highest diagnostic yields (50%). Furthermore, if the biopsies were obtained from enhancing regions, the yield of these two approaches increased to 84 and 100%, respectively. Of 18 cases in which biopsy samples were taken from both the meninges and cortex, only 1 had cortical involvement alone. The meninges were therefore diagnostic in 15 of the 16 definitive diagnostic cases (94%). Second biopsies were necessary in four cases, of which the three biopsies from enhancing regions were diagnostic. The most frequent causes of chronic meningitis were sarcoid (31%) and metastatic adenocarcinoma (25%).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Cerebral Cortex/pathology , Meninges/pathology , Meningitis/pathology , Adult , Aged , Aged, 80 and over , Biopsy , Brain Diseases/complications , Brain Diseases/pathology , Brain Neoplasms/complications , Brain Neoplasms/pathology , Brain Neoplasms/secondary , Chronic Disease , Diagnosis, Differential , Female , Granulomatosis with Polyangiitis/complications , Granulomatosis with Polyangiitis/pathology , Humans , Magnetic Resonance Imaging , Male , Meningeal Neoplasms/complications , Meningeal Neoplasms/pathology , Meningeal Neoplasms/secondary , Meningitis/etiology , Middle Aged , Sarcoidosis/complications , Sarcoidosis/pathology , Tomography, X-Ray Computed
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