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1.
Phys Rev Lett ; 130(5): 051801, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36800472

RESUMO

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νßß) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νßß decay half-life of T_{1/2}^{0ν}>2.3×10^{26} yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

2.
Phys Rev Lett ; 122(19): 192501, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31144924

RESUMO

We present a precision analysis of the ^{136}Xe two-neutrino ßß electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ßß rate allows us to measure the ratio of the leading and subleading 2νßß nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ßß decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ßß NMEs.

3.
Int J Lab Hematol ; 30(4): 292-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18665826

RESUMO

High costs of molecule-targeted drugs, such as rituximab, ibritumomab, and tositumomab have given rise to an economical issue for treating patients with non-Hodgkin's lymphoma (NHL). Granulocyte colony-stimulating factors (G-CSFs), which are also expensive, are widely used for treating neutropenia after chemotherapy. In Japan, lenograstim at 2 microg/kg (about 100 microg/body) or filgrastim at 50 microg/m(2) (about 75 microg/body) is commonly administered for patients with NHL after chemotherapy. Therefore, cost-effectiveness is an important issue in treatment for NHL. Patients with advanced-stage NHL who needed chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or a CHOP-like regimen with or without rituximab were enrolled in this randomized cross-over trial to investigate the efficacy and safety of low-dose G-CSF. Half of the patients were administered 75 microg filgrastim in the first course after neutropenia and 50 microg lenograstim in the second course, and the other half were crossed over. Forty-seven patients were enrolled in this cross-over trial, and 24 patients completed the trial. Frequencies and durations of grade 4 leukocytopenia and neutropenia were similar in the two groups. Severe infection was rare and was observed at similar frequency. Frequencies of antibiotics use were also similar. The total cost of G-CSF (cost/drug x duration of administration) was significantly lower in patients who received 50 microg lenograstim. Hence, a low dose of lenograstim might be safe, effective and pharmaco-economically beneficial in patients with advanced-stage NHL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Fator Estimulador de Colônias de Granulócitos/economia , Linfoma não Hodgkin/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Custo-Benefício , Estudos Cross-Over , Feminino , Filgrastim , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Lenograstim , Linfoma não Hodgkin/economia , Masculino , Pessoa de Meia-Idade , Neutropenia/tratamento farmacológico , Neutropenia/etiologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/economia
4.
Int J Lab Hematol ; 30(1): 75-81, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18190473

RESUMO

A 65-year-old Japanese male was diagnosed as multiple myeloma with Bence Jones kappa type, clinical stage IIIA. His disease status reached partial remission after chemotherapy. Thereafter, he received tandem transplantation, consisting of high-dose chemotherapy with autologous stem cell transplantation (ASCT), followed by unrelated cord blood transplantation (U-CBT). U-CBT with a reduced-intensity conditioning regimen (RI-CBT) was performed in August 2003. HLA mismatch between the patient and the CBT donor was present at two serological loci (B and DR). A total nucleated CBT cell dose of 2.45 x 10(7)/kg body weight was infused on day 0. Graft-vs.-host disease (GVHD) prophylaxis consisted of cyclosporine A and short-term methotrexate. Neutrophil engraftment (>0.5 x 10(9)/l) was obtained on day 46. He developed positive cytomegalovirus antigenemia, grade II acute GVHD involving skin and liver, varicella-zoster virus infection, septic shock, hemorrhagic cystitis caused by adenovirus and acute hepatitis B virus infection after U-CBT. We retrospectively analyzed T-cell receptor (TCR) repertoire diversity and found that TCR repertoire diversity decreased continuously after U-CBT. Therefore, low-TCR repertoire diversity in this patient appears to be associated with various infections caused by immunodeficiency.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Mieloma Múltiplo/terapia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Quimeras de Transplante , Viroses/imunologia , Idoso , Humanos , Hospedeiro Imunocomprometido , Masculino , Linfócitos T/efeitos da radiação , Condicionamento Pré-Transplante , Transplante Autólogo , Viroses/complicações
5.
Clin Lab Haematol ; 28(5): 351-4, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16999729

RESUMO

A 33-year-old woman underwent unrelated cord blood transplantation (U-CBT) for myelodysplastic syndrome (MDS)-related secondary AML. She showed impressive increases in the number of CD19+ B cells in bone marrow and CD19+27-IgD+ B cells in peripheral blood from about 1 month to 3 months after U-CBT. The serum level of IL-6 temporarily increased after transplantation, and this increase seemed to be correlated with the expansion of CD19+ B cells. Although, compared with BMT, little is known about the kinetics of hematological and immunological reconstitution in U-CBT, there was initial B-cell recovery after CBT as some described. This B cell recovery may be associated with a high number of B-cell precursors present in cord blood (CB). The phenomenon of naïve B lymphocyte expansion that we found might be associated with a high number of B-cell precursors present in CB.


Assuntos
Subpopulações de Linfócitos B/classificação , Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Sobrevivência de Enxerto , Adulto , Subpopulações de Linfócitos B/citologia , Feminino , Humanos , Imunofenotipagem/métodos , Leucemia Mieloide Aguda/terapia , Ativação Linfocitária/imunologia , Síndromes Mielodisplásicas/terapia , Transplante Homólogo
7.
Br J Anaesth ; 94(5): 577-81, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15722386

RESUMO

BACKGROUND: This study was designed to determine cardiovagal baroreflex gain during propofol infusion and to characterize its recovery profile using the pharmacological and spontaneous sequence methods in 13 healthy volunteers without cardiovascular or autonomic disorders. METHODS: After an 8- to 10-h fast and no premedication, measurements of RR intervals obtained from the electrocardiogram and non-invasive beat-to-beat systolic blood pressure (SP) were made at conscious baseline, at 60 and 120 min after induction of general anaesthesia using propofol, and at 20, 60, 120 and 180 min after emergence from anaesthesia. During propofol anaesthesia, ventilation was mechanically controlled to maintain normocapnia and calculated propofol concentration was adjusted by a TCI system at 5 microg ml(-1). Baroreflex responses were triggered by bolus i.v. injections of phenylephrine and nitroprusside to alter SP by 15-30 mm Hg. The linear portions of the baroreflex curves relating RR intervals and SP by least-square regression analysis were determined to obtain pharmacological gains. In addition, spontaneous sequence baroreflex gains were calculated from spontaneously fluctuating SP and RR intervals. RESULTS: Baseline pressor and depressor test gains before propofol anaesthesia were 29.1 (SD 14.9) and 12.5 (7.8) ms mm Hg(-1), respectively. They were significantly depressed by 65-73% during propofol infusions. Similarly, baseline up- and down-sequence baroreflex gains were 33.8 (28.9) and 27.3 (19.8) ms mm Hg(-1), respectively, and were significantly depressed by 71-87% during propofol anaesthesia. Pressor test and up-sequence baroreflex gains returned to the baseline values 20 min after emergence from propofol anaesthesia, but depressor test and down-sequence baroreflex gains did not recover until 60 min after emergence. CONCLUSIONS: We conclude that heart rate responses to both lowering and elevating blood pressure were depressed by propofol anaesthesia, and 60 min was required for their full recovery after discontinuation of propofol infusion.


Assuntos
Anestésicos Intravenosos/farmacologia , Barorreflexo/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Propofol/farmacologia , Adulto , Período de Recuperação da Anestesia , Anestésicos Intravenosos/sangue , Barorreflexo/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Propofol/sangue
8.
Transplant Proc ; 36(8): 2511-2, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15561299

RESUMO

We investigated the expression of the inhibitory NKR (CD94/NKG2A) of the G-CSF mobilized peripheral blood mononuclear cells (G-PBMC) on T cells after stimulation for 7 days by immobilized anti-CD3 monoclonal antibody (mAb) with or without cytokines. We demonstrated increased expression of CD94/NKG2A on CD3+/CD8+ T cells. Also, addition of IL-12 induced significantly more CD94/NKG2A expression than addition of IL-15: CD94+CD3+/NKG2A+CD3+; 43.8 +/- 11.6%/33.7 +/- 11.4% by IL-12 versus 32.8 +/- 13.2%/21.3 +/- 9.6% by IL-15, respectively (n = 9, P < .05). However, >90% purified CD94+ cells CD94+ obtained from IL-15-treated G-PBMC by magnetic cell sorting (MACS) exhibited higher cytolytic (CTL) activity against K562 cells than that from IL-12-treated G-PBMC: E:T = 20:1, 40.7 +/- 18.4% vs 15.1 +/- 5.2% (n = 5, P < .05). Therefore, the cytokine effects on inhibitory NKR expression on T cells and CTL activity are differently regulated. Based on these findings, it may be possible to establish the effective strategy to expand inhibitory NKR-expressing T cells with CTL activity for cell therapy.


Assuntos
Antígenos CD/genética , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células-Tronco Hematopoéticas , Células Matadoras Naturais/imunologia , Lectinas Tipo C/genética , Receptores Imunológicos/genética , Linfócitos T/imunologia , Anticorpos Monoclonais/farmacologia , Antígenos CD/imunologia , Complexo CD3/imunologia , Citocinas/farmacologia , Mobilização de Células-Tronco Hematopoéticas , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Doadores Vivos , Ativação Linfocitária , Subfamília C de Receptores Semelhantes a Lectina de Células NK , Subfamília D de Receptores Semelhantes a Lectina de Células NK , Receptores de Células Matadoras Naturais , Linfócitos T/efeitos dos fármacos
9.
Cancer ; 92(10): 2699-708, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11745206

RESUMO

BACKGROUND: The International Neuroblastoma Pathology Classification (International Classification), which was established in 1999, is significant prognostically and is relevant biologically for the evaluation and analysis of patients with neuroblastic tumors (NTs). MYCN amplification is a known molecular marker for aggressive progression of NTs. These have been used together as important prognostic factors to define risk groups for patient stratification and protocol assignment. METHODS: A total of 628 NTs (535 neuroblastomas [NBs]); 21 ganglioneuroblastoma, intermixed [GNBi]; 9 ganglioneuromas [GN]; and 63 ganglioneuroblastoma, nodular [GNBn]) from the Children's Cancer Group studies were evaluated histologically (favorable histology [FH] tumors vs. unfavorable histology [UH] tumors) according to the International Classification and were tested molecularly for MYCN status (amplified vs. nonamplified). Four tumor subsets (FH-nonamplified, FH-amplified, UH-nonamplified, and UH-amplified) were defined by histopathology and MYCN status, and their prognostic effects were analyzed. Detailed analysis between morphologic indicators (grade of neuroblastic differentiation and mitosis-karyorrhexis index [MKI]) and MYCN status was done by using tumors in the NB category. RESULTS: There were 339 FH-nonamplified tumors (5-year event free survival [EFS], 92.1%); 8 FH-amplified tumors (EFS, 37.5%); 172 UH-nonamplified tumors (EFS, 40.9%); and 109 UH-amplified tumors (EFS, 15.0%). The prognostic effects on patients with tumors in the four subsets were independent from the factors of patient age and disease stage (P < 0.0001). MYCN amplification was seen almost exclusively in tumors of the NB category, and no patients with tumors in either the GNBi category or in the GN category and only two patients with tumors in the GNBn category had amplified MYCN. Among the patients with tumors in the NB category, patients with FH-nonamplified tumors (309 patients) had an excellent prognosis, and patients with UH-amplified tumors (107 patients) had the poorest clinical outcome in any age group. The prognosis for children with UH-nonamplified tumors (111 patients) was poor when they were diagnosed at age > 1.5 years. It was also noted that patients with UH-amplified tumors (median age, 2.14 years) were diagnosed at a significantly younger age compared with the patients with UH-nonamplified tumors (median age, 3.55 years). Histologically, MYCN-amplified tumors lacked neuroblastic differentiation regardless of the age of patients. MYCN amplification also was linked generally to increased mitotic and karyorrhectic activities. However, MKI classes in patients with MYCN-amplified tumors varied significantly, depending on the age at diagnosis, and younger patients had higher MKI classes. CONCLUSIONS: The combination of histopathologic evaluation and MYCN status distinguishes four clinical and biologic tumor subsets in patients with NTs. MYCN amplification seems to be the powerful driving force for preventing cellular differentiation regardless of patient age and for increasing mitotic and karyorrhectic activities in an age dependent manner.


Assuntos
Biomarcadores Tumorais/análise , Ganglioneuroblastoma/genética , Ganglioneuroblastoma/patologia , Ganglioneuroma/genética , Ganglioneuroma/patologia , Neuroblastoma/genética , Neuroblastoma/patologia , Neoplasias do Sistema Nervoso Periférico/genética , Neoplasias do Sistema Nervoso Periférico/patologia , Proteínas Proto-Oncogênicas c-myc/genética , Adolescente , Criança , Pré-Escolar , Feminino , Amplificação de Genes , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Proteínas Proto-Oncogênicas c-myc/análise , Fatores de Risco
10.
Cancer ; 92(9): 2451-61, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11745303

RESUMO

BACKGROUND: The International Neuroblastoma Pathology Classification was established in 1999 for the prognostic evaluation of patients with neuroblastic tumors (NTs). METHODS: Pathology slides from 746 NTs (the Children's Cancer Group [CCG]-3881 and CCG-3891 studies) were evaluated according to the International Classification. First, prognostic effects of the morphologic indicators (grade of neuroblastic differentiation: undifferentiated [U], poorly differentiated [PD] and differentiating [D]; and mitosis-karyorrhexis index [MKI]: low [L-MKI], intermediate [I-MKI], and high [H-MKI]) for tumors in the neuroblastoma (NB) category were tested. Then, prognostic significance of the International Classification for all NTs in four categories (neuroblastoma [NB]; ganglioneuroblastoma, intermixed [GNBi]; ganglioneuroma [GN]; and ganglioneuroblastoma, nodular [GNBn]) was analyzed. Finally, age distribution of the patients in the four categories as well as three subtypes (based on the grade of differentiation) in the NB category was compared. RESULTS: There were 630 NB tumors, 30 GNBi tumors, 10 GN tumors, and 76 GNBn tumors. In the NB category, prognostic effects of the indicators (three grades of differentiation and three mitosis-karyorrhexis index [MKI] classes: low [L], intermediate [I], and high [H]) were affected significantly by the age of the patients. The age-linked evaluation of the indicators according to the International Classification successfully distinguished two prognostic subgroups: the favorable histology (FH) subgroup (PD/D and L/I-MKI tumors in patients age < 1.5 years, D and L-MKI tumors in patients ages 1.5-5.0 years; 90.4% 5-year event free survival [EFS]) and the unfavorable histology (UH) subgroup (U and/or H-MKI tumors in patients of any age, PD and/or I-MKI tumors in patients ages 1.5-5.0 years, any grade of differentiation, and any MKI class in patients age > or = 5 years; 26.9% EFS) (P < 0.0001). The International Classification also distinguished the FH group (FH subgroup with NB, GNBi, and GN tumors) and the UH group (UH subgroup with NB and GNBn tumors) for all NTs (90.8% EFS and 31.2% EFS, respectively; P < 0.0001) and provided independent prognostic information on both patient age and disease stage (P < 0.0001). Among patients with FH tumors, the median ages of patients with the PD and D subtype tumors in the NB category were 0.43 years (range, 0-1.50 years) and 1.50 years (range, 0.02-4.65 years), respectively, and the median ages of patients with GNBi and GN tumors were 3.51 years (range, 0.96-14.85 years) and 4.80 years (range, 1.94-17.05 years), respectively. In contrast, patients with UH tumors generally were older when they were diagnosed, and with median ages of 2.99 years (range, 1.30-8.84 years) for patients with U subtype tumors, 2.59 years (range, 0.0-12.57 years) for patients with PD subtype tumors, 2.16 years (range, 0.35-9.90) for patients with D subtype tumors, and 3.26 years (range, 0.57-15.90 years) for patients with GNBn tumors. CONCLUSIONS: This study confirmed the prognostic significance of the International Classification, substantiated age-linked prognostic effects of the morphologic indicators for patients with the tumors in the NB category, and supported the concept of an age-appropriate framework of maturation for patients with the tumors in the FH group.


Assuntos
Ganglioneuroblastoma/classificação , Ganglioneuroblastoma/patologia , Neuroblastoma/classificação , Neuroblastoma/patologia , Neoplasias do Sistema Nervoso Periférico/classificação , Neoplasias do Sistema Nervoso Periférico/patologia , Adolescente , Fatores Etários , Diferenciação Celular , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Cooperação Internacional , Masculino , Mitose , Prognóstico , Análise de Sobrevida
11.
Eur J Drug Metab Pharmacokinet ; 26(1-2): 129-35, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11554427

RESUMO

The possibility of pharmacokinetic interactions between Saiko-ka-ryukotsu-borei-to extract powder (TJ-12), a widely used traditional Chinese herbal (Kampo) medicine, and carbamazepine (CBZ), an important anti-epileptic drug, was examined in rats. There were no significant differences in the serum protein binding of CBZ and carbamazepine- 10,11-epoxide (CBZ-E), its active metabolite, at two concentrations (1 and 10 Bg/ml) between twogroups pretreated orally with the vehicle andTJ-12 suspension (1 g/kg/d, p.o.) for 1 week. One-week repeated pretreatment with TJ- 12 (1 g/kg/d) did not influence liver weight, contents of cytochromes P450 and b5 in hepatic microsomes or the formation rate of CBZ-E from CBZ by its microsomes, while pretreatment with phenobarbital (80 mg/kg/d, i.p.) significantly increased these parameters. Neither a single nor 1-week repeated oral pretreatment with TJ-12 (1 g/kg/d) affected the plasma concentration-time profile and any pharmacokinetic parameter of CBZ or CBZ-E after oral administration of CBZ (50 mg/kg). These results indicated that oral co-administration of TJ-12 with CBZ has no effect ofthe pharmacokinetics of CBZ or CBZ-E in rats. Concomitant treatment with TJ- 12 and CBZ appears to be pharmacokinetically safe in humans.


Assuntos
Anticonvulsivantes/farmacologia , Anticonvulsivantes/farmacocinética , Carbamazepina/farmacologia , Carbamazepina/farmacocinética , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/farmacocinética , Animais , Biotransformação , Proteínas Sanguíneas/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Feminino , Interações Ervas-Drogas , Técnicas In Vitro , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Medicina Kampo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Ligação Proteica , Ratos , Ratos Wistar
12.
Cancer ; 89(5): 1150-61, 2000 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10964346

RESUMO

BACKGROUND: Ganglioneuroblastoma, nodular (GNBn) is a rare subtype of the family of neuroblastic tumors (neuroblastoma, ganglioneuroblastoma, and ganglioneuroma) that are classified in the unfavorable histology group according to the International Neuroblastoma Pathology Classification (Shimada system). Tumors of this subtype have been considered to represent a prototypic example of biologically and clinically nonaggressive (Schwannian stroma-rich and stroma-dominant) components combined with biologically and clinically aggressive nodular (Schwannian stroma-poor) components. However, detailed histopathologic analysis as well as thorough prognostic evaluation of patients with this subtype has not been reported. METHODS: Pathology slides and reports from a total of 70 GNBn patients from the Children's Cancer Group (CCG)-3881 and CCG-3891 studies were reviewed. Sixty-eight tumors were classified in the favorable subset (FS) or the unfavorable subset (US) based on the evaluation of nodular components by applying the same histopathologic criteria (patient age, grade of neuroblastic differentiation, mitosis-karyorrhexis index) that are used for neuroblastomas in the International Neuroblastoma Pathology Classification. Patient prognosis as well as clinical and biologic characteristics within the subsets were analyzed, and the results were compared with those from 654 non-GNBn patients who were enrolled in the same CCG studies during the same period. RESULTS: Patients with GNBn tumors, usually diagnosed at age > 1 year, had a significantly lower overall 5-year event free survival (EFS) rate than patients with non-GNBn subtypes (44.7% EFS vs. 65.0% EFS; P = 0. 0073). A significant difference in the outcome of the patients between the FS (22 patients; 86.1% EFS; 95.0% survival rate) and the US (46 patients; 29.0% EFS; 40.7% survival rate) of the GNBn subtype (P < 0.0005) was shown. When the cohort of patients with GNBn tumors was subdivided into FS and US, the outcomes were similar to those of patients with tumors of favorable histology (397 patients; 90.5% EFS; 97.6% survival rate) and with tumors of unfavorable histology (257 patients; 27.0% EFS; 35.7% survival rate) of the non-GNBn type. The patients with US tumors frequently (63.0%) presented with distant metastasis. CONCLUSIONS: The current study demonstrates that the nodular components in GNBn tumors are not always aggressive. The prognosis of these patients can be determined by the analysis of age-linked histopathologic features.


Assuntos
Ganglioneuroblastoma/patologia , Fatores Etários , Pré-Escolar , Ganglioneuroblastoma/classificação , Ganglioneuroblastoma/diagnóstico , Ganglioneuroblastoma/mortalidade , Humanos , Lactente , Estadiamento de Neoplasias , Prognóstico
13.
Spine (Phila Pa 1976) ; 25(13): 1617-24, 2000 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-10870136

RESUMO

STUDY DESIGN: Change in lumbar lordosis was measured in patients that had undergone posterolateral lumbar fusions using transpedicular instrumentation. The biomechanical effects of postoperative lumbar malalignment were measured in cadaveric specimens. OBJECTIVES: To determine the extent of postoperative lumbar sagittal malalignment caused by an intraoperative kneeling position with 90 degrees of hip and knee flexion, and to assess its effect on the mechanical loading of the instrumented and adjacent segments. SUMMARY OF BACKGROUND DATA: The importance of maintaining the baseline lumbar lordosis after surgery has been stressed in the literature. However, there are few objective data to evaluate whether postoperative hypolordosis in the instrumented segments can increase the likelihood of junctional breakdown. METHODS: Segmental lordosis was measured on preoperative standing, intraoperative prone, and postoperative standing radiographs. In human cadaveric spines, a lordosis loss of up to 8 degrees was created across L4-S1 using calibrated transpedicular devices. Specimens were tested in extension and under axial loading in the upright posture. RESULTS: In patients who underwent L4-S1 fusions, the lordosis within the fusion decreased by 10 degrees intraoperatively and after surgery. Postoperative lordosis in the proximal (L2-L3 and L3-L4) segments increased by 2 degrees each, as compared with the preoperative measures. Hypolordosis in the instrumented segments increased the load across the posterior transpedicular devices, the posterior shear force, and the lamina strain at the adjacent level. CONCLUSIONS: Hypolordosis in the instrumented segments caused increased loading of the posterior column of the adjacent segments. These biomechanical effects may explain the degenerative changes at the junctional level that have been observed as long-term consequences of lumbar fusion.


Assuntos
Lordose/fisiopatologia , Lordose/cirurgia , Vértebras Lombares/fisiopatologia , Vértebras Lombares/cirurgia , Fusão Vertebral/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Lordose/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/fisiopatologia , Postura , Radiografia , Estudos Retrospectivos , Resultado do Tratamento , Suporte de Carga
14.
Biomed Mater Eng ; 7(3): 179-91, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9262831

RESUMO

This paper presents a constitutive law of the lumbar intervertebral disc to be described mathematically with the finite deformation theory. Mechanical behavior of the cadaveric lumbar disc obtained from continuous cyclic compression-tension tests and continuous cyclic axial torsion tests was formulated by the constitutive equation with a semi-circular shaped model. These equations were formulated with or without taking the nucleus pulposus into account. It was also confirmed that forward-backward bending behavior of the disc could be simulated numerically from these equations.


Assuntos
Disco Intervertebral/fisiologia , Vértebras Lombares/fisiologia , Modelos Biológicos , Fenômenos Biomecânicos , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Dinâmica não Linear , Estresse Mecânico , Suporte de Carga/fisiologia
15.
Spine (Phila Pa 1976) ; 21(7): 811-9; discussion 820, 1996 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8779011

RESUMO

STUDY DESIGN: Local elastic moduli of sliced intervertebral disc specimens were studied after establishing the relation between the elastic modulus and indentation behaviors by model tests using polyurethane specimens. OBJECTIVES: This study presents a method to quantify the distribution of compressive elastic moduli in the lumbar intervertebral disc and to clarify the effects of degeneration on the distribution. SUMMARY OF BACKGROUND DATA: No study has been performed to evaluate the distribution of axial compressive elastic moduli, which is supposed to relate previous biomechanical, biological, and biochemical findings regarding the intervertebral disc. METHODS: Local compressive elastic moduli of the intervertebral disc were estimated by indentation tests. To evaluate the distribution of elastic moduli, indentation tests were performed at nodal points of a 10 mm x 10 mm network on a specimen. Nine cadaveric lumbar discs (L3-L4 and L4-L5) with various degrees of degeneration were tested. The age of subjects ranged 39 to 90 years (mean, 58.4 years). RESULTS: The distribution of elastic moduli in normal discs was symmetric about the midsagittal plane. The mean elastic modulus in the nucleus pulposus was 5.8 kPa and those of the anterior and posterior anulus fibrosus were 110.7 and 75.8 kPa, respectively. The elastic moduli in the lateral portions were the lowest in the normal anulus, and were close to the values of the nucleus. Compared to normal discs, degenerated discs showed irregular distributions of elastic moduli. The elastic moduli of the degenerated nucleus were higher than those in normal discs. CONCLUSIONS: The distribution of elastic moduli is much different between discs with and without degeneration.


Assuntos
Tecido Elástico/patologia , Disco Intervertebral/patologia , Vértebras Lombares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Tecido Elástico/fisiologia , Feminino , Humanos , Disco Intervertebral/fisiologia , Vértebras Lombares/fisiologia , Masculino , Matemática , Pessoa de Meia-Idade
17.
Spine (Phila Pa 1976) ; 17(11): 1343-52, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1462210

RESUMO

Cyclic axial compression-tension tests and cyclic torsional tests were performed on ten fresh human L4-5 functional spinal units to investigate the structural effects of the posterior elements on the mechanical properties of L4-5 functional spinal units. The stiffness of the functional spinal unit increased with the increase of displacement under every loading. This was same in the intact functional spinal units and the functional spinal units after removal of each posterior element, respectively. All the posterior elements contributed to the compressive, tensile, and torsional stiffness of L4-5 functional spinal units. The apophyseal joints had a significant effect on the compressive and torsional stiffness. The effect of the apophyseal joints on the torsional stiffness became greater according to the extent of displacement, whereas their effect on the compressive stiffness was constant. The posterior ligaments (supraspinous and interspinous ligaments) had a significant effect on the tensile stiffness.


Assuntos
Vértebras Lombares/fisiologia , Resistência à Tração/fisiologia , Suporte de Carga/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
Jpn J Cancer Res ; 79(11): 1184-92, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3147274

RESUMO

We have established a human cell line, designated KT, with high susceptibility to both cell proliferation inhibition by interferon and UV-killing, from a metastatic breast carcinoma. A tumor marker, a pregnancy-specific glycoprotein (Schwangerschaftsprotein 1; SP1), and carcinoma characteristics compatible with ductal carcinoma of the breast were seen in KT cells by electron microscopic observation. KT cells were slightly more resistant to X-ray-induced toxicity than fibroblastic cells, termed KS, from the scalp of the patient. But, KT cells had lower cloning efficiency after UV irradiation than did KS cells: D0 values of 1.5 J/m2 and 7.2 J/m2, respectively. KT cells also appeared more susceptible to human interferon (HuIFN) preparations (alpha, beta, gamma and natural or recombinant) than did KS cells, as measured by cell colony formation ability, proliferation rates, and [3H]deoxythymidine incorporation levels into acid-insoluble cell materials. The sensitivity of KT cells to UV and HuIFN was greater than that of human RSa cells, a cell line with high sensitivity to both agents. KT cells had more capacity for UV-induced DNA-repair replication synthesis than did RSa cells, the capacity being much the same as that of KS cells. There was no significant difference in levels of antiviral activity induced by HuIFN and binding capacity for 125I-labeled IFN-alpha A between KT and KS cells. KT cells appeared refractory to cell proliferation inhibition by tumor necrosis factor (TNF) preparations.


Assuntos
Neoplasias Encefálicas/patologia , Interferon Tipo I/farmacologia , Tolerância a Radiação , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Reparo do DNA , Humanos , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologia , Raios Ultravioleta
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