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1.
Clin Radiol ; 78(1): e13-e21, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36116967

RESUMO

AIM: To evaluate 1.5 T magnetic resonance imaging (MRI) brain images with denoising procedures using deep learning-based reconstruction (dDLR) relative to the original 1.5 and 3 T images. MATERIALS AND METHODS: Eleven volunteers underwent MRI at 3 and 1.5 T. Two-dimensional fast spin-echo T2-weighted imaging (T2WI), fluid-attenuated inversion recovery (FLAIR) imaging and diffusion-weighted imaging (DWI) sequences were performed. The dDLR method was applied to the 1.5 T data (dDLR-1.5 T), then the image quality of the dDLR-1.5 T data relative to the original 1.5 T and 3 T data was qualitatively and quantitatively assessed based on the structure similarity (SSIM) index; the signal-to-noise ratios (SNRs) of the grey matter (GM) and white matter (WM); and the contrast-to-noise ratios (CNRs) between the GM and WM (CNRgm-wm) and between the striatum (ST) and WM (CNRst-wm). RESULTS: The perceived image quality, and SNRs and CNRs were significantly higher for the dDLR-1.5 T images versus the 1.5 T images for all sequences and almost comparable or even superior to those of the 3 T images. For DWI, the SNRs and CNRst-wm were significantly higher for the dDLR-1.5 T images versus the 3 T images. CONCLUSION: The dDLR technique improved the image quality of 1.5 T brain MRI images. With respect to qualitative and quantitative measurements, the denoised 1.5 T brain images were almost equivalent or even superior to the 3 T brain images.


Assuntos
Neoplasias Encefálicas , Aprendizado Profundo , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Encefálicas/patologia
2.
Eur Cell Mater ; 36: 68-80, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-30069865

RESUMO

The application of extracellular matrix (ECM) sheets without a scaffold is not extensively reported in bone regenerative medicine. The aim of the present study was to demonstrate that an osteogenic ECM sheet (OECMS) can retain ECM integrity and growth factors to enhance bone formation in a rat non-union model. OECMS was produced from osteogenic cell sheets (OCS). Collagen and growth factor [bone morphogenetic protein 2 (BMP-2), vascular endothelial growth factors (VFGFs), basic fibroblast growth factor (bFGF) and transforming growth factor ß1 (TGF-ß1)] concentrations in the OECMS were quantified by enzyme-linked immunosorbent assay (ELISA). Next, hydroxyapatite (HA) constructs combined with OECMSs were implanted subcutaneously into the rats' backs to evaluate their osteoinductive capacity by histological evaluation. In addition, OECMSs were implanted in a rat femoral non-union model. 18 male Fischer 344 inbred rats were divided into OECMS and control groups. Fracture healing was evaluated by radiological and histological analyses at 2, 5 and 8 weeks and biological analysis at 8 weeks. Collagen I and growth factors were retained in the OECMSs. Osteoid formation was identified in the HA combined with OECMS at 4 weeks. Enhanced bone regeneration at the non-union of the OECMS group was confirmed at 5 and 8 weeks. Biomechanical testing revealed a significantly higher maximum bending load in the OECMS group as compared to the control group at 8 weeks. The results demonstrated that OECMS retained BMP-2 and TGF-ß1 and high osteoinductive and osteoconductive capacity. As such, OECMS represents a potential new scaffold-free material for bone tissue engineering.


Assuntos
Regeneração Óssea/fisiologia , Matriz Extracelular/metabolismo , Fêmur/fisiologia , Osteogênese , Animais , Fenômenos Biomecânicos , Sobrevivência Celular , Colágeno Tipo I/metabolismo , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/patologia , Fraturas do Fêmur/fisiopatologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Implantação de Prótese , Ratos Endogâmicos F344
3.
Bone Joint Res ; 5(11): 569-576, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27881440

RESUMO

OBJECTIVES: To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone. METHODS: Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed in vitro, and the appearance of the cell sheets was observed after mechanical retrieval using a scraper. ß-tricalcium phosphate (ß-TCP) was then wrapped with the cell sheets from the four different groups and subcutaneously implanted into rats. RESULTS: After mechanical retrieval, the osteogenic cell sheets from the MEM, MEM with AscP, and MEM with Dex groups appeared to be fragmented or incomplete structures. The cell sheets cultured with Dex/AscP remained intact after mechanical retrieval, without any identifiable tears. Culture with Dex/AscP increased the mRNA and protein expression of extracellular matrix proteins and cell number compared with those of the other three groups. More bridging bone formation was observed after transplantation of the ß-TCP scaffold wrapped with cell sheets cultured with Dex/AscP, than in the other groups. CONCLUSIONS: These results suggest that culture with Dex/AscP improves the mechanical integrity of the osteogenic cell sheets, allowing retrieval of the confluent cells in a single cell sheet structure. This method may be beneficial when applied in cases of difficult tissue reconstruction, such as nonunion, bone defects, and osteonecrosis.Cite this article: M. Akahane, T. Shimizu, T. Kira, T. Onishi, Y. Uchihara, T. Imamura, Y. Tanaka. Culturing bone marrow cells with dexamethasone and ascorbic acid improves osteogenic cell sheet structure. Bone Joint Res 2016;5:569-576. DOI: 10.1302/2046-3758.511.BJR-2016-0013.R1.

4.
Acta Gastroenterol Belg ; 74(2): 352-4, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21861324

RESUMO

We present the case of a 32-year-old female with cecal and appendiceal polyps that were removed by laparoscopy-assisted surgery. She also had recurrent nosebleeds due to telangiectases in the nasal mucosa and arteriovenous malformations in the lung, all of which contributed to the diagnosis of hereditary hemorrhagic telangiectasia.


Assuntos
Apêndice , Ceco , Polipose Intestinal/complicações , Telangiectasia Hemorrágica Hereditária/complicações , Adulto , Colonoscopia , Diagnóstico Diferencial , Feminino , Humanos , Polipose Intestinal/diagnóstico , Telangiectasia Hemorrágica Hereditária/diagnóstico , Tomografia Computadorizada por Raios X
5.
Int Angiol ; 30(4): 359-65, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21747359

RESUMO

AIM: The aim of this paper was to evaluate our single-center experience of the management of splenic artery aneurysm (SAA), with particular attention to the long-term results of endovascular treatment. METHODS: Thirty-eight patients with the diagnosis of SAA at the Tokyo University Hospital during the past 23 years were retrospectively reviewed. Interventions were considered for patients with SAA>2 cm in diameter. Nine patients were treated by transcatheter embolization (TE), and 8 by open surgical repair (SR). Twenty-one patients were observed (OB). TE was performed with microcoils placed distal and proximal to the aneurysm in the afferent artery to isolate the aneurysm. RESULTS: In the TE group, the primary technical success rate was 100%. No 30-day mortality or any catheter-related complication was observed. The median length of hospital stay after TE, excluding one patient who required further surgery, was shorter than that after SR (8 versus 16 days, P=0.001). During follow-up (median =45 months), no patient died and no recurrence of SAA was observed. In the SR group, all aneurysms were repaired successfully without any severe complication, and no aneurysm-related death occurred during follow-up (median =57 months). In the OB group, no aneurysm rupture or increase in aneurysm size was observed during follow-up (median =35 months). CONCLUSION: TE provided good early and long-term results, comparable to those obtained with conventional SR. In addition, TE had several advantages associated with its minimal invasiveness. TE by the isolation technique could be the first-line strategy for all SAA requiring treatment.


Assuntos
Aneurisma/terapia , Embolização Terapêutica , Procedimentos Endovasculares , Artéria Esplênica/cirurgia , Procedimentos Cirúrgicos Vasculares , Idoso , Aneurisma/diagnóstico por imagem , Aneurisma/cirurgia , Embolização Terapêutica/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Feminino , Hospitais Universitários , Humanos , Japão , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Artéria Esplênica/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Conduta Expectante
7.
Clin Nephrol ; 73(4): 253-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20353732

RESUMO

AIM: Autoimmune pancreatitis (AIP) is a rare subtype of chronic pancreatitis. AIP has been suggested to be complicated by tubulointerstitial nephritis or glomerulonephritis, implying that the kidney is involved as a phenotype of IgG4-positive multi-organ lymphoproliferative syndrome; however, the clinical significance of this novel entity is not well-defined. METHODS: We conducted a retrospective cohort analysis of 47 (male, 39; female, 8) AIP patients. RESULTS: The patients (mean age, 70.3 +/- 9.5 years) had a mean observation period of 4.1 years. Before treatment, renal dysfunction with an eGFR of 30 and 15 ml/min/1.73 m2 developed only in 10.6% (5/47) and 2.1% (1/47) of the patients, respectively. Nevertheless, urinary N-acetyl-beta-D-glucosaminidase and alpha1-microglobulin levels were elevated in 78.6% (11/14) and 30.8% (4/13) of the patients, respectively. Renal involvement in contrast-enhanced CT imaging was present in 18.2% (8/44) of the patients and was associated with proteinuria (p = 0.04) and a decrease in eGFR (p < 0.01). Furthermore, a follow-up CT study (mean, 545 days) revealed improved kidney lesions in 80.0% (4/5) of the patients after oral corticosteroid administration. In contrast, first-time kidney involvements appeared newly in 3.6% (1/28) of the patients after steroid therapy for nonrenal AIP symptoms, and in 14.3% (1/7) of the patients under no specific therapy (p = 0.02). CONCLUSION: Although severe renal failure develops rarely in AIP patients, renal abnormalities have been significantly detected by biochemical and radiological tests. Oral corticosteroid administration, even when not targeting symptomatic nephropathy, can treat and prevent kidney involvements in AIP.


Assuntos
Doenças Autoimunes/patologia , Nefropatias/patologia , Rim/patologia , Pancreatite Crônica/patologia , Doenças Autoimunes/complicações , Doenças Autoimunes/diagnóstico por imagem , Doenças Autoimunes/tratamento farmacológico , Estudos de Coortes , Feminino , Glucocorticoides/uso terapêutico , Humanos , Rim/diagnóstico por imagem , Nefropatias/complicações , Nefropatias/diagnóstico por imagem , Nefropatias/tratamento farmacológico , Masculino , Pancreatite Crônica/complicações , Pancreatite Crônica/diagnóstico por imagem , Pancreatite Crônica/tratamento farmacológico , Prednisona/uso terapêutico , Radiografia , Análise de Regressão , Estudos Retrospectivos , Resultado do Tratamento
8.
Epidemiol Infect ; 138(10): 1493-502, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20067657

RESUMO

We constructed a syndromic surveillance system to collect directly information on daily health conditions directly from local residents via the internet [web-based daily questionnaire for health surveillance system (WDQH SS)]. This paper considers the feasibility of the WDQH SS and its ability to detect epidemics. A verification study revealed that our system was an effective surveillance system. We then applied an improved WDQH SS as a measure against public health concerns at the G8 Hokkaido Toyako Summit meeting in 2008. While in operation at the Summit, our system reported a fever alert that was consistent with a herpangina epidemic. The highly mobile WDQH SS described in this study has three main advantages: the earlier detection of epidemics, compared to other surveillance systems; the ability to collect data even on weekends and holidays; and a rapid system set-up that can be completed within 3 days.


Assuntos
Surtos de Doenças , Internet , Vigilância de Evento Sentinela , Inquéritos e Questionários , Adulto , Feminino , Humanos , Masculino
9.
Int J Stem Cells ; 3(2): 138-43, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-24855551

RESUMO

We previously reported a new cell transplantation method utilizing injections of mesenchymal stem cell (MSC) sheets that have osteogenic potential. After subcutaneous transplantation without any scaffold, the sheet demonstrated in vivo bone formation. In the present study, we transplanted such sheets by injection into implanted ceramics and assessed whether the injectable MSC sheets could stimulate osteogenic integration of the ceramics. To fabricate MSC sheets, bone marrow cells cultured from femur shafts of 7-week-old rats were subcultured in regular 10-cm dishes containing dexamethasone and ascorbic acid phosphate until confluent. Each cell sheet was then lifted using a scraper. Porous ß-tricalcium phosphate (ß-TCP) disks (5 mm Φ×2 mm) were transplanted subcutaneously into the backs of the rats. Immediately following implantation, the sheets were injected around the disks via a 16G needle (immediate group). Cell sheets were also injected into the remaining implanted disks 1 week after disk implantation (1-wk group). Four weeks following sheet injection, radiography and histology revealed calcification and bone tissue around the harvested disks of the immediate group (eight disks exhibited bone formation/eight implanted disks), whereas calcification and bone tissue were observed in 50% of the samples in the 1-wk group (four disks exhibited bone formation/eight implanted disks). The present study indicates that injected cell sheets can supply osteogenic potential to implanted ceramics. Owing to the usage of a needle for cell sheet transplantation, such an injection method can be applied as a minimally invasive technique of osteogenic supply to implanted ceramics.

10.
Br J Radiol ; 82(976): e67-71, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19325041

RESUMO

Various splenic inflammatory pseudotumours are reported to be infected with Epstein-Barr virus (EBV), which is thought to be associated with the pathogenesis of the lesion. The term "inflammatory pseudotumour (IPT)-like follicular dendritic cell tumour", all cases of which are also EBV positive, has recently been proposed. Here, we describe the imaging findings of these splenic tumours and present the cases of an IPT-like follicular dendritic cell tumour and two EBV-positive inflammatory pseudotumours in two female patients and one male patient. These splenic lesions were found incidentally on pre-operative or post-operative screening or at medical check-up. CT performed on all three patients revealed low-density solitary masses in the spleen. MRI was performed on one patient; the solitary mass demonstrated isointensity on T(1) weighted images and low intensity on T(2) weighted images relative to the surrounding splenic parenchyma. Dynamic MRI study revealed that the mass did not enhance on the early phase but enhanced to the same degree as the surrounding splenic parenchyma on the delayed phase. The imaging findings are almost identical to those found in conventional IPT because the morphology is similar in both cases; however, attention should be paid to this new entity in the diagnosis of splenic lesions because of its neoplastic nature. Longer follow-up is also necessary for these patients compared with those with conventional IPT.


Assuntos
Neoplasias da Mama , Sarcoma de Células Dendríticas Foliculares/diagnóstico , Infecções por Vírus Epstein-Barr/diagnóstico , Granuloma de Células Plasmáticas/diagnóstico , Neoplasias Esplênicas/diagnóstico , Neoplasias Gástricas , Idoso , Meios de Contraste , Sarcoma de Células Dendríticas Foliculares/virologia , Detecção Precoce de Câncer , Feminino , Granuloma de Células Plasmáticas/virologia , Humanos , Achados Incidentais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esplenopatias/diagnóstico , Esplenopatias/virologia , Neoplasias Esplênicas/virologia , Tomografia Computadorizada por Raios X
14.
Hand Surg ; 10(2-3): 231-5, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16568519

RESUMO

We evaluated rat bone viability using a bone viability index (BVI). To evaluate hypothermic ischaemic bone injury, 21 amputated hind limbs of Fischer rats were preserved at hypothermia (4 degrees C) for 1, 3 and 6 hours. To evaluate hypothermic ischaemia/reperfusion injury, another 28 amputated limbs were transplanted to recipient rats after hypothermic ischaemia for 3 and 6 hours, respectively. Total RNA isolated from each tibia was fractionated by electrophoresis and hybridised with 32P-labelled cDNA of GAPDH, and the radioactivity of intact and degraded GAPDH mRNA measured. BVI was calculated as follows, BVI = [A / (A + B)] x 100, where A and B represent the radioactivities corresponding to intact and degraded GAPDH mRNA bands, respectively. In the hypothermic ischaemic insult group, BVIs were comparable to those of controls. However, in the 3-hour hypothermic ischaemia/reperfusion group, BVI was lower than that of the controls. Likewise, there was a significant difference between the 6-hour ischaemia/reperfusion group and controls. These results showed that bone viability decreased even after just a 3-hour hypothermic ischaemia/reperfusion.


Assuntos
Osso e Ossos , Hipotermia Induzida , Traumatismo por Reperfusão/patologia , Sobrevivência de Tecidos , Animais , Northern Blotting , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos F344 , Reimplante
15.
Br J Radiol ; 75(894): 548-51, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12124245

RESUMO

We present the case of a patient who showed increased accumulation of (123)I-metaiodobenzylguanidine (MIBG) in hepatocellular carcinoma, leading to a false presumptive diagnosis of intrahepatic neuroendocrine tumour. The increase in uptake was not seen on images obtained 4 h after tracer injection but was evident on those taken after 24 h, suggesting slower washout from the liver tumour than from non-tumoural liver parenchyma. Our observations indicate that a non-neuroendocrine malignant tumour may exhibit high accumulation of MIBG associated with prolonged retention.


Assuntos
3-Iodobenzilguanidina/farmacocinética , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Compostos Radiofarmacêuticos/farmacocinética , Idoso , Carcinoma Hepatocelular/diagnóstico por imagem , Diagnóstico Diferencial , Reações Falso-Positivas , Humanos , Hipertensão/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/metabolismo , Cintilografia
16.
Br J Plast Surg ; 55(2): 136-9, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11987947

RESUMO

We report a muscle viability index (MVI) that reflects mRNA degradation. The viability of hypothermically preserved (48C) rat skeletal muscle was evaluated using this MVI. To evaluate the hypothermic ischaemic insult of the muscle, 21 hind limbs of Fischer rats (three subgroups of seven limbs each) were hypothermically preserved for 1h, 3h and 6h, before harvesting the tibialis anterior muscle. To investigate reperfusion injury after hypothermic preservation, an additional 28 limbs were transplanted to recipient Fischer rats after hypothermic ischaemia for either 3h or 6h. The transplanted muscles were harvested on either day 3 or day 7 after transplantation. Seven fresh muscles were also harvested, and used as controls. In the 3h ischaemia group, the MVIs of both the hypothermic-ischaemia and the ischaemia-reperfusion subgroups were comparable to the controls. Likewise, there were no significant differences between the controls and the 6h hypothermic ischaemia and ischaemia-reperfusion subgroups. These results show that muscle viability is maintained with hypothermic preservation of up to 6h, and after reperfusion. Therefore, in clinical replantations the amputated extremity should be preserved under hypothermic conditions from the time of injury to the time of surgery.


Assuntos
Hipotermia Induzida , Músculo Esquelético/irrigação sanguínea , RNA Mensageiro/genética , Reimplante , Preservação de Tecido/métodos , Animais , Expressão Gênica , Sobrevivência de Enxerto , Membro Posterior/cirurgia , Isquemia/genética , Isquemia/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos F344 , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/fisiopatologia
17.
Hand Surg ; 7(2): 191-5, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12596278

RESUMO

This prospective study investigated static scapholunate dissociation (SLD) in wrists associated with distal radius fractures. SLD was detected as a widening of the scapholunate (SL) joint interval by SL gap view. Ninety-six distal radius fractures and 154 normal wrists were investigated by SL gap view, which is better for detecting SLD than the standard posteroanterior (PA) view. Incidences of non-symptomatic SLD detected by SL gap view in normal wrists increased by age. In the young age bracket, incidences of SLD in distal radius fractures were significantly higher than in normal wrists. Our results indicated that in patients younger than 30 years old, SLD in distal radius fractures was a fracture-caused abnormality. In those over 30, ascribing SLD to the fracture was difficult. Close examinations, like arthroscopy and dynamic cineradiography, need to be made in patients with SLD associated with distal radius fractures, especially in those younger than 30.


Assuntos
Ligamentos Articulares/lesões , Osso Semilunar/lesões , Osso Escafoide/lesões , Traumatismos do Punho/diagnóstico , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Osso Semilunar/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiografia , Fraturas do Rádio/complicações , Fraturas do Rádio/diagnóstico por imagem , Osso Escafoide/diagnóstico por imagem , Traumatismos do Punho/complicações , Articulação do Punho/diagnóstico por imagem
18.
Bioorg Med Chem ; 9(12): 3265-71, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11711302

RESUMO

In a search for novel analogues of beta(3)-adrenoceptor (AR) agonists relaxing the bladder for treatment of urinary dysfunction, 2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl)phenoxy]-2-methylpropionic acids (1a-e), into which a fibrate-like structure had been incorporated, were synthesised. Compound 1a was found to be a selective beta(3)-AR agonist in functional assays using the ferret detrusor (beta(3)-AR), rat uterus (beta(2)-AR), and rat atrium (beta(1)-AR); beta(3): EC(50)=7.8 nM, beta(2): IC(50)=7,300 nM, beta(1): EC(20)=23,000 nM. The introduction of a chlorine atom or methyl substituent at the ortho-position on the phenyl ring of 1a further improved beta(3)-AR selectivity. In an in vivo study, 1a lowered intrabladder pressure (ED(50)=31 microg/kg) in rats, without increasing heart rate, in keeping with the in vitro results. Consequently, it is proposed that 1a and its analogues (1b-e), possess beta(3)-AR agonistic activity in the absence of undesirable beta(1)- or beta(2)-AR mediated actions, and may be useful for clinical treatment and pharmacological studies.


Assuntos
Agonistas de Receptores Adrenérgicos beta 3 , Agonistas Adrenérgicos beta/química , Agonistas Adrenérgicos beta/farmacologia , Propionatos/química , Propionatos/farmacologia , Incontinência Urinária/tratamento farmacológico , Micção/efeitos dos fármacos , Animais , Bioquímica/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Furões , Átrios do Coração/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Fenóis , Ratos , Relação Estrutura-Atividade , Útero/efeitos dos fármacos
19.
J Orthop Res ; 19(4): 559-64, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11518262

RESUMO

The rat's skeletal muscle viability was evaluated using the muscle viability index (MVI) which reflects the mRNA degradation. To evaluate ischemic injury of the muscle, 24 hind limbs of Fischer rats (three subgroups of eight rats each) were preserved at normothermia for 1, 3 and 6 h and then tibialis anterior muscle was harvested. To investigate ischemia/reperfusion injury, another 48 limbs were transplanted to recipient Fischer rats after the ischemia at normothermia for 1, 3 and 6 h, respectively. The transplanted muscles were harvested on day 3 and day 7 after transplantation. Eight fresh muscles were also harvested and used as control. Total RNA isolated from each muscle was fractionated by electrophoresis and hybridized with 32P-labelled cDNA of GAPDH, and the radioactivity of intact and degraded GAPDH mRNA was measured. MVI was calculated as follows, MVI = [X/(X + Y)] x 100, where X and Y represent the radioactivities corresponding to intact GAPDH and degraded GAPDH mRNA band, respectively. In 1-h ischemia group, the MVI indices of both ischemic insult and ischemia/reperfusion group were comparable to control. In the 3-h ischemia group, the index of ischemia/reperfused group was comparable to control although the index of ischemic insult group was significantly lower than control. However, in the 6-h ischemia group, both indices of ischemic insult and ischemia/reperfusion group were significantly lower than control. These results show that the muscle damage was detected in ischemia at normothermia even after 3 h. However, this damage was overcome by reperfusion. There was no recovery from damage in muscles that had been preserved for more than 6 h which had resulted in irreversible degeneration. Therefore, in clinical muscle transplantation, one has to transplant the muscle at least within 3-h ischemia.


Assuntos
Sobrevivência de Enxerto/fisiologia , Músculo Esquelético/fisiopatologia , Músculo Esquelético/transplante , RNA Mensageiro/metabolismo , Traumatismo por Reperfusão/fisiopatologia , Animais , Northern Blotting , Temperatura Corporal , Masculino , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos F344
20.
Clin Exp Pharmacol Physiol ; 28(7): 545-50, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11422222

RESUMO

1. In the present study, we investigated the prophylactic effects of pilocarpine hydrochloride on xerostomia models induced by either single (15 Gy) or repeated (8.6 Gy x3 days) X-ray irradiation in rats. Pilocarpine hydrochloride was administered orally 90 min before each irradiation session. Then, 7 days later, salivary volume, amylase activity and protein concentration in the saliva secreted from the right parotid gland were measured before and after a subsequent administration of pilocarpine hydrochloride (intraduodenal). 2. In irradiated no-pretreatment rats, irradiation induced a significant reduction in both spontaneous and pilocarpine hydrochloride-stimulated secretion (both total salivary volume and flow rate), regardless of the protocol used for X-ray exposure. In irradiated, pilocarpine hydrochloride-pretreated rats, salivary secretion was increased after stimulation by pilocarpine hydrochloride (intraduodenal) to a degree that depended on the pretreatment dose of pilocarpine hydrochloride (p.o.) in both xerostomia models. 3. There were no differences in amylase or protein concentrations between irradiated rats pretreated with pilocarpine hydrochloride and irradiated no-pretreatment control rats. 4. A decrease in the weight of the parotid gland was observed in rats exposed to either the single dose or repeated irradiation protocols. Changes in the submandibular gland were less marked than those in the parotid gland. These changes in gland weight were not affected by pilocarpine hydrochloride pretreatment. 5. The responsiveness of the parotid gland to subsequent stimulation with pilocarpine hydrochloride was apparently preserved in both xerostomia models by pretreatment with pilocarpine hydrochloride, which itself increased salivary secretion. This suggests that pilocarpine hydrochloride may exert functional protective effects against xerostomia that occurs following irradiation therapy through a stimulation of salivary secretion.


Assuntos
Agonistas Muscarínicos/uso terapêutico , Pilocarpina/uso terapêutico , Xerostomia/prevenção & controle , Animais , Masculino , Agonistas Muscarínicos/administração & dosagem , Pilocarpina/administração & dosagem , Cintilografia , Ratos , Ratos Sprague-Dawley , Saliva/metabolismo , Raios X , Xerostomia/diagnóstico por imagem
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