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3.
Eur J Radiol ; 157: 110561, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36308849

RESUMO

BACKGROUND: Achieving pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) improves survival outcomes for breast cancer patients. Currently, conventional histopathological biomarkers predicting such responses are inconsistent. Studies investigating radiomic texture analysis from breast magnetic resonance imaging (MRI) to predict pCR have varied radiomic protocols introducing heterogeneity between results. Thus, the efficacy of radiomic profiles compared to conventional strategies to predict pCR are inconclusive. PURPOSE: Comparing the predictive accuracy of different breast MRI radiomic protocols to identify the optimal strategy in predicting pCR to NAC. MATERIAL AND METHODS: A systematic review and network meta-analysis was performed according to PRISMA guidelines. Four databases were searched up to October 4th, 2021. Nine predictive strategies were compared, including conventional biomarker parameters, MRI radiomic analysis conducted before, during, or after NAC, combination strategies and nomographic methodology. RESULTS: 14 studies included radiomic data from 2,722 breast cancers, of which 994 were used in validation cohorts. All MRI derived radiomic features improved predictive accuracy when compared to biomarkers, except for pre-NAC MRI radiomics (odds ratio [OR]: 0.00; 95 % CI: -0.07-0.08). During-NAC and post-NAC MRI improved predictive accuracy compared to Pre-NAC MRI (OR: 0.14, 95 % CI: 0.02-0.26) and (OR: 0.26, 95 % CI: 0.07-0.45) respectively. Combining multiple MRIs did not improve predictive performance compared to Mid- or Post-NAC MRIs individually. CONCLUSION: Radiomic analysis of breast MRIs improve identification of patients likely to achieve a pCR to NAC. Post-NAC MRI are the most accurate imaging method to extrapolate radiomic data to predict pCR.


Assuntos
Neoplasias da Mama , Terapia Neoadjuvante , Humanos , Feminino , Terapia Neoadjuvante/métodos , Metanálise em Rede , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mama/diagnóstico por imagem , Mama/patologia , Imageamento por Ressonância Magnética/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Estudos Retrospectivos
4.
BJS Open ; 5(5)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34633438

RESUMO

BACKGROUND: OncotypeDX® recurrence score (RS) aids therapeutic decision-making in oestrogen-receptor-positive (ER+) breast cancer. Radiomics is an evolving field that aims to examine the relationship between radiological features and the underlying genomic landscape of disease processes. The aim of this study was to perform a systematic review of current evidence evaluating the comparability of radiomics and RS. METHODS: A systematic review was performed as per PRISMA guidelines. Studies comparing radiomic MRI tumour analyses and RS were identified. Sensitivity, specificity and area under curve (AUC) delineating low risk (RS less than 18) versus intermediate-high risk (equal to or greater than 18) and low-intermediate risk (RS less than 30) and high risk (RS greater than 30) were recorded. Log rate ratios (lnRR) and standard error were determined from AUC and 95 per cent confidence intervals. RESULTS: Nine studies including 1216 patients met inclusion criteria; the mean age at diagnosis was 52.9 years. Mean RS was 16 (range 0-75); 401 patients with RS less than 18, 287 patients with RS 18-30 and 100 patients with RS greater than 30. Radiomic analysis and RS were comparable for differentiating RS less than 18 versus RS 18 or greater (RR 0.93 (95 per cent c.i. 0.85 to 1.01); P = 0.010, heterogeneity (I2)=0%) as well as RS less than 30 versus RS 30 or greater (RR 0.76 (95 per cent c.i. 0.70 to 0.83); P < 0.001, I2=0%). MRI sensitivity and specificity for RS less than 18 versus 18 or greater was 0.89 (95 per cent c.i. 0.85 to 0.93) and 0.72 (95 per cent c.i. 0.66 to 0.78) respectively, and 0.79 (95 per cent c.i. 0.72 to 0.86) and 0.74 (95 per cent c.i. 0.68 to 0.80) for RS less than 30 versus 30 or greater. CONCLUSION: Radiomic tumour analysis is comparable to RS in differentiating patients into clinically relevant subgroups. For patients requiring MRI, radiomics may complement and enhance RS for prognostication and therapeutic decision making in ER+ breast cancer.


Assuntos
Neoplasias da Mama , Imageamento por Ressonância Magnética , Área Sob a Curva , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/genética , Feminino , Humanos
5.
Breast ; 58: 113-120, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34022714

RESUMO

INTRODUCTION: OncotypeDX© Recurrence Score (RS) is a multigene panel used to aid therapeutic decision making in early-stage, estrogen receptor positive (ER+)/human epidermal growth factor receptor-2 negative (HER2-) breast cancer. AIM: To compare responses to neoadjuvant endocrine therapy (NET) in patients with ER+/HER2-breast cancer following substratification by RS testing. METHODS: This systematic review was performed in accordance to the PRISMA guidelines. Studies evaluating pathological complete response (pCR), partial response (PR), and successful conversion to breast conservation surgery (BCS) rates following NET guided by RS were retrieved. Dichotomous outcomes were reported as odds ratios (ORs) with 95% confidence intervals (CIs) following estimation by Mantel-Haenszel method. RESULTS: Eight prospective studies involving 691 patients were included. The mean age was 62.6 years (range 25-85) and the mean RS was 14.5 (range 0-68). Patients with RS < 25 (OR: 4.60, 95% CI: 2.53-8.37, P < 0.001) and RS < 30 (OR: 3.40, 95% CI: 1.96-5.91, P < 0.001) were more likely to achieve PR than their counterparts. NET prescription failed to increase BCS conversion rates for patients with RS < 18 (OR: 0.23, 95% CI: 0.04-1.47, P = 0.120) and RS > 30 (OR: 1.27, 95% CI: 0.64-2.49, P = 0.490) respectively. Only 22 patients achieved pCR (2.8%) and RS group failed to predict pCR following NET (P = 0.850). CONCLUSION: Estimations from this analysis indicate that those with low-intermediate RS on core biopsy are four times more likely to respond to NET than those with high-risk RS. Performing RS testing on diagnostic biopsy may be useful in guiding NET prescription.


Assuntos
Neoplasias da Mama , Terapia Neoadjuvante , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Prognóstico , Estudos Prospectivos , Receptor ErbB-2 , Receptores de Estrogênio
6.
BJS Open ; 5(3)2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-34013318

RESUMO

BACKGROUND: Oestrogen receptor (ER) status provides invaluable prognostic and therapeutic information in breast cancer (BC). When clinical decision making is driven by ER status, the value of progesterone receptor (PgR) status is less certain. The aim of this study was to describe clinicopathological features of ER-positive (ER+)/PgR-negative (PgR-) BC and to determine the effect of PgR negativity in ER+ disease. METHODS: Consecutive female patients with ER+ BC from a single institution were included. Factors associated with PgR- disease were assessed using binary logistic regression. Oncological outcome was assessed using Kaplan-Meier and Cox regression analysis. RESULTS: In total, 2660 patients were included with a mean(s.d.) age of 59.6(13.3) years (range 21-99 years). Median follow-up was 97.2 months (range 3.0-181.2). Some 2208 cases were PgR+ (83.0 per cent) and 452 were PgR- (17.0 per cent). Being postmenopausal (odds ratio (OR) 1.66, 95 per cent c.i. 1.25 to 2.20, P < 0.001), presenting with symptoms (OR 1.71, 95 per cent c.i. 1.30 to 2.25, P < 0.001), ductal subtype (OR 1.51, 95 per cent c.i. 1.17 to 1.97, P = 0.002) and grade 3 tumours (OR 2.20, 95 per cent c.i. 1.68 to 2.87, P < 0.001) were all associated with PgR negativity. In those receiving neoadjuvant chemotherapy (308 patients), pathological complete response rates were 10.1 per cent (25 of 247 patients) in patients with PgR+ disease versus 18.0 per cent in PgR- disease (11 of 61) (P = 0.050). PgR negativity independently predicted worse disease-free (hazard ratio (HR) 1.632, 95 per cent c.i. 1.209 to 2.204, P = 0.001) and overall survival (HR 1.774, 95 per cent c.i. 1.324 to 2.375, P < 0.001), as well as worse overall survival in ER+/HER2- disease (P = 0.004). CONCLUSIONS: In ER+ disease, PgR- tumours have more aggressive clinicopathological features and worse oncological outcomes. Neoadjuvant and adjuvant therapeutic strategies should be tailored according to PgR status.


Assuntos
Neoplasias da Mama , Receptores de Progesterona , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/tratamento farmacológico , Estrogênios , Feminino , Humanos , Pessoa de Meia-Idade , Receptor ErbB-2/genética , Receptores de Estrogênio/genética , Adulto Jovem
7.
Br J Surg ; 108(6): 622-631, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-33963374

RESUMO

BACKGROUND: Uncertainty exists regarding the clinical relevance of programmed cell death ligand 1 (PD-L1) expression in breast cancer. METHODS: A systematic review was performed in accordance with PRISMA guidelines. Observational studies that compared high versus low expression of PD-L1 on breast cancer cells were identified. Log hazard ratios (HRs) for disease-free and overall survival and their standard errors were calculated from Kaplan-Meier curves or Cox regression analyses, and pooled using the inverse-variance method. Dichotomous variables were pooled as odds ratios (ORs) using the Mantel-Haenszel method. RESULTS: Sixty-five studies with 19 870 patients were included; 14 404 patients were classified as having low and 4975 high PD-L1 expression. High PD-L1 was associated with achieving a pathological complete response following neoadjuvant chemotherapy (OR 3.30, 95 per cent confidence interval 1.19 to 9.16; P < 0.01; I2 = 85 per cent). Low PD-L1 expression was associated with human epidermal growth factor receptor 2 (OR 3.98, 1.81 to 8.75; P < 0.001; I2 = 96 per cent) and luminal (OR 14.93, 6.46 to 34.51; P < 0.001; I2 = 99 per cent) breast cancer subtypes. Those with low PD-L1 had favourable overall survival rates (HR 1.30, 1.05 to 1.61; P = 0.02; I2 = 85 per cent). CONCLUSION: Breast cancers with high PD-L1 expression are associated with aggressive clinicopathological and immunohistochemical characteristics and are more likely to achieve a pathological complete response following neoadjuvant chemotherapy. These breast cancers are, however, associated with worse overall survival outcomes.


Assuntos
Antígeno B7-H1/metabolismo , Neoplasias da Mama/patologia , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/metabolismo , Feminino , Humanos , Prognóstico
8.
Breast ; 56: 26-34, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33582622

RESUMO

BACKGROUND: The non-inferiority of combined breast conservation surgery (BCS) and radiotherapy (breast conservation therapy or BCT) compared to mastectomy in sporadic breast cancer cases is well recognised. Uncertainty remains regarding optimal surgical practice in BRCA mutation carriers. AIMS: To evaluate the oncological safety of combined BCT versus mastectomy in BRCA mutation carriers following breast cancer diagnosis. METHODS: A systematic review was performed as per PRISMA and MOOSE guidelines. Observational studies comparing BCS and mastectomy in BRCA carriers were identified. Dichotomous variables were pooled as odds ratios (OR) using the Mantel-Haenszel method. Log hazard ratios (lnHR) for locoregional recurrence (LRR), contralateral breast cancer, disease-free and overall survival and their standard errors were calculated from Kaplan-Meier or cox-regression analyses and pooled using the inverse variance method. RESULTS: Twenty three studies of 3807 patients met inclusion criteria; 2200 (57.7%) were BRCA1 and 1212 (31.8%) were BRCA2 carriers. Median age at diagnosis was 41 years with 96 months follow up. BCS was performed on 2157 (56.7%) while 1408 (41.5%) underwent mastectomy. An increased risk of LRR was observed in patients treated with BCS (HR:4.54, 95% Confidence Interval: 2.77-7.42, P < 0.001, heterogeneity (I2) = 0%). However, the risks of contralateral breast cancer (HR:1.51, 95%CI: 0.44-5.11, P = 0.510, I2 = 80%), disease recurrence (HR:1.16, 95%CI: 0.78-1.72, P = 0.470, I2 = 44%), disease-specific recurrence (HR:1.58, 95%CI: 0.79-3.15, P = 0.200, I2 = 38%) and death (HR:1.10, 95%CI: 0.72-1.69, P = 0.660, I2 = 38%) were equivalent for combined BCT and mastectomy. CONCLUSIONS: Survival outcomes following combined BCT is comparable to mastectomy in BRCA carriers. However, the risk of LRR is increased. Patient counselling should be tailored to incorporate these findings.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Mastectomia Segmentar , Radioterapia Adjuvante , Neoplasias da Mama/cirurgia , Feminino , Genes BRCA2 , Humanos , Mastectomia , Mutação , Recidiva Local de Neoplasia/genética
9.
Surg Oncol ; 37: 101531, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33545657

RESUMO

BACKGROUND: The molecular era has identified four breast cancer subtypes. Luminal A breast cancer (LABC) is defined by estrogen-receptor positive (ER+), progesterone-receptor positive (PgR+) and human epidermal growth factor receptor-2 negative (HER2-) tumours; these cancers are the most common and carry favourable prognoses. AIMS: To describe clinicopathologic features, oncological outcome and relapse patterns in LABC. METHODS: Consecutive female patients diagnosed with ER/PgR+/HER2-, lymph node negative (LN-) breast cancer between 2005 and 2015 were included. Clinicopathological and recurrence data was recorded using descriptive statistics. Oncological outcome was determined using Kaplan-Meier and Cox-regression analyses. RESULTS: Analysis was performed for 849 patients with median follow-up of 102.1 months. Mean disease-free (DFS) and overall survival (OS) were 85.8% and 91.8%. Seventy patients died during this study (8.2%), while 58 patients had recurrence; 7 had local recurrence (0.8%) and 51 had distant recurrence (DDR) (6.0%). Patients developing DDR were likely to be postmenopausal (P = 0.028), present symptomatically (P < 0.001) and have larger tumours (P < 0.001). The mean time to DDR was 65.7 months, with fatal recurrence occurring in 66.6% of patients with DDR (34/51). Systemic chemotherapy prescription did not influence DDR (P = 0.053). Age >65 (hazards ratio (HR):1.66, 95% Confidence Interval (CI):1.07-2.55, P = 0.022), presenting symptomatically (HR:2.28, 95%CI:1.21-4.29, P = 0.011) and tumour size >20 mm (HR:1.81, 95%CI:1.25-2.62, P = 0.002) predicted DFS, while age>65 (HR:2.60, 95%CI:1.49-4.53, P = 0.001) and being postmenopausal at diagnosis (HR:3.13, 95%CI:1.19-8.22, P = 0.020) predicted OS. CONCLUSION: Our series demonstrated excellent survival outcomes for patients diagnosed with LN- LABC after almost a decade of follow-up. However, following DDR, fatal progression is often imminent.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Irlanda/epidemiologia , Linfonodos/patologia , Pessoa de Meia-Idade , Metástase Neoplásica/patologia , Recidiva Local de Neoplasia , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona , Estudos Retrospectivos , Fatores de Risco
10.
Surg Case Rep ; 6(1): 234, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32990818

RESUMO

BACKGROUND: Intussusception in adult patients is uncommon and appendiceal lead points are particularly rare. CASE PRESENTATION: We present the case of a 42-year-old male with a history of ulcerative colitis, presenting with sudden onset abdominal pain and bloody diarrhoea. Endoscopy revealed grossly normal mucosa in the descending colon with a congested polypoid mass in the proximal transverse colon. Computed tomography revealed ileocecal intussusception at the hepatic flexure. A right hemicolectomy was performed, where a grossly dilated appendix was noted, resected and sent for histopathological evaluation. Results revealed low-grade appendiceal mucinous neoplasm. Post-operatively, the patient remained symptom free, however required reintroduction of biologic therapy due to relapse of his ulcerative colitis 12 weeks later. CONCLUSION: This case depicts a rare acute surgical presentation and reminds physicians and surgeons of the importance of 'thinking outside the box' in clinical practice.

11.
Gene Ther ; 19(2): 201-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21654824

RESUMO

Viral vector-mediated gene transfer to the postnatal respiratory epithelium has, in general, been of low efficiency due to physical and immunological barriers, non-apical location of cellular receptors critical for viral uptake and limited transduction of resident stem/progenitor cells. These obstacles may be overcome using a prenatal strategy. In this study, HIV-1-based lentiviral vectors (LVs) pseudotyped with the envelope glycoproteins of Jaagsiekte sheep retrovirus (JSRV-LV), baculovirus GP64 (GP64-LV), Ebola Zaire-LV or vesicular stomatitis virus (VSVg-LV) and the adeno-associated virus-2/6.2 (AAV2/6.2) were compared for in utero transfer of a green fluorescent protein (GFP) reporter gene to ovine lung epithelium between days 65 and 78 of gestation. GFP expression was examined on day 85 or 136 of gestation (term is ∼145 days). The percentage of the respiratory epithelial cells expressing GFP in fetal sheep that received the JSRV-LV (3.18 × 10(8)-6.85 × 10(9) viral particles per fetus) was 24.6±0.9% at 3 weeks postinjection (day 85) and 29.9±4.8% at 10 weeks postinjection (day 136). Expression was limited to the surface epithelium lining fetal airways <100 µm internal diameter. Fetal airways were amenable to VSVg-LV transduction, although the percentage of epithelial expression was low (6.6±0.6%) at 1 week postinjection. GP64-LV, Ebola Zaire-LV and AAV2/6.2 failed to transduce the fetal ovine lung under these conditions. These data demonstrate that prenatal lung gene transfer with LV engineered to target apical surface receptors can provide sustained and high levels of transgene expression and support the therapeutic potential of prenatal gene transfer for the treatment of congenital lung diseases.


Assuntos
Técnicas de Transferência de Genes , Vetores Genéticos/administração & dosagem , Proteínas de Fluorescência Verde/metabolismo , Retrovirus Jaagsiekte de Ovinos/genética , Pulmão/embriologia , Ovinos/genética , Animais , Baculoviridae/genética , Dependovirus/genética , Ebolavirus/genética , Feto , Células HEK293 , Humanos , Hialuronoglucosaminidase/genética , Hialuronoglucosaminidase/metabolismo , Lentivirus/genética , Pulmão/crescimento & desenvolvimento , Mucosa Respiratória/crescimento & desenvolvimento , Mucosa Respiratória/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
12.
Cytogenet Genome Res ; 117(1-4): 231-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17675864

RESUMO

The traditional strength of chicken embryos for studying development is that they are readily manipulated. This has led to some major discoveries in developmental biology such as the demonstration that the neural crest gives rise to almost the entire peripheral nervous system and the identification of signalling centres that specify the pattern of structures in the central nervous system and limb. More recently with the burgeoning discovery of developmentally important genes, chicken embryos have provided useful models for testing function. Uncovering the molecular basis of development provides direct links with clinical genetics. In addition, since many genes that have crucial roles in development are also expressed in tumours, basic research on chickens has implications for understanding human health and disease. Now that the chicken genome has been sequenced and genomic resources for chicken are becoming increasingly available, this opens up opportunities for combining these new technologies with the manipulability of chicken embryos and also exploiting comparative genomics.


Assuntos
Galinhas/metabolismo , Modelos Biológicos , Animais , Comunicação Celular , Embrião de Galinha , Regulação da Expressão Gênica no Desenvolvimento , Genômica , Humanos , Transdução de Sinais , Tretinoína/metabolismo
13.
Dev Biol ; 301(1): 155-65, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-16959240

RESUMO

Chicken talpid(3) mutant embryos have a wide range of Hedgehog-signalling related defects and it is now known that the talpid(3) gene product encodes a novel protein essential for Hedgehog signalling which is required for both activator and repressor functions of Gli transcription factors (Davey, M.G., Paton, I.R., Yin, Y., Schmidt, M., Bangs, F.K., Morrice, D.R., Gordon-Smith, T., Buxton, P., Stamataki, D., Tanaka, M., Münsterberg, A.E., Briscoe, J., Tickle, C., Burt, D.W. (2006). The chicken talpid(3) gene encodes a novel protein essential for Hedgehog signalling. Genes Dev 20 1365-77). Haemorrhaging, oedema and other severe vascular defects are a central aspect of the talpid(3) phenotype (Ede, D.A. and Kelly, W.A (1964a). Developmental abnormalities in the head region of the talpid(3) mutant fowl. J. Embryol. exp. Morp. 12:161-182) and, as Hedgehog (Hh) signalling has been implicated in every stage of development of the vascular system, the vascular defects seen in talpid(3) are also likely to be attributable to abnormal Hedgehog signalling. Gene expression of members of the VEGF and Angiopoietin families of angiogenic growth factors has been linked to haemorrhaging and oedema and we find widespread expression of VEGF-D, rigf and Ang2a in the talpid(3) limb. Furthermore, ectopic expression of these genes in talpid(3) limbs points to regulation via Gli repression rather than activation. We monitored specification of vessel identity in talpid(3) limb vasculature by examining expression of artery-specific genes, Np1 and EphrinB2, and the vein-specific genes, Np2a and Tie2. We show that there are supernumerary subclavian arteries in talpid(3) limb buds and abnormal expression of an artery-specific gene in the venous submarginal sinus, despite the direction of blood flow being normal. Furthermore, we show that Shh can induce Np1 expression but has no effect on Np2a. Finally, we demonstrate that induction of VEGF and Ang2a expression by Shh in normal limb buds is accompanied by vascular remodelling. Thus Hedgehog signalling has a pivotal role in the cascade of angiogenic events in a growing embryonic organ which is similar to that proposed in tumours.


Assuntos
Proteínas Hedgehog/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Botões de Extremidades/metabolismo , Transdução de Sinais , Animais , Sequência de Bases , Vasos Sanguíneos/metabolismo , Embrião de Galinha , Primers do DNA , Hibridização In Situ , Botões de Extremidades/irrigação sanguínea , Microscopia Eletrônica de Transmissão
14.
Pediatr Pulmonol ; 34(4): 278-86, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12205569

RESUMO

We examined the effect of accelerated lung growth, induced by in utero tracheal occlusion (TO), on lung liquid uptake in near-term fetal sheep. In utero TO was performed in five fetal sheep at 110 days of gestation (term, approximately 145 days); six SHAM operated fetuses served as controls. The rate of liquid movement across the pulmonary epithelium was measured, using a previously established technique, in anesthetized fetal sheep between 133-137 days of gestation during a 2-hr adrenaline infusion (0.50 microg/min/kg, I.V.) and while lung luminal pressure was maintained at 5 mmHg. The rate of fetal lung liquid uptake was linear in all fetuses (mean r(2) < 0.97, n = 11). Mean values of lung liquid uptake expressed in relation to dry lung weight and luminal surface area of the right lung were significantly lower in TO fetuses (1.8 +/- 0.3 mL/hr/g and 1.0 +/- 0.2 mL/hr/m(2)) than in SHAM fetuses (2.6 +/- 0.2 mL/hr/g and 1.8 +/- 0.1 mL/hr/m(2)); surface area of the right lung was 140% greater in TO fetuses than in SHAM fetuses. There was a linear relationship between lung liquid uptake and pulmonary epithelial surface area in SHAM animals, but not in TO fetuses. We hypothesize that loss of alveolar epithelial type-II cells induced by increased levels of fetal lung expansion may impair alveolar liquid clearance in the perinatal period.


Assuntos
Transporte Biológico/fisiologia , Células Epiteliais/metabolismo , Água Extravascular Pulmonar/metabolismo , Pulmão/crescimento & desenvolvimento , Alvéolos Pulmonares/metabolismo , Traqueia/cirurgia , Animais , Transporte Biológico/efeitos dos fármacos , Gasometria , Pressão Sanguínea/fisiologia , Modelos Animais de Doenças , Epinefrina/farmacologia , Frequência Cardíaca/fisiologia , Concentração de Íons de Hidrogênio , Pulmão/embriologia , Medidas de Volume Pulmonar , Pressão , Alvéolos Pulmonares/embriologia , Ovinos/embriologia , Traqueia/embriologia
15.
Biochem J ; 111(5): 733-43, 1969 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-5783473

RESUMO

1. A substance has been isolated from the venom of the Okinawan pit viper (Trimeresurus okinavensis) that causes the aggregation of human blood platelets. The reaction resembles that between platelets and thrombin or connective tissue, in that the platelets release ADP. 2. The purified venom fraction is a protein-polysaccharide, and after Pronase digestion had mol.wt. 4x10(6), containing 10% peptide, 85% neutral sugars and 5% hexosamines. It is distinct from the proteolytic, esterolytic and coagulant materials also present in the venom, and has not been shown to possess any enzymic activity. How it reacts with platelets is not yet known.


Assuntos
Plaquetas/efeitos dos fármacos , Serpentes , Peçonhas/análise , Nucleotídeos de Adenina/metabolismo , Animais , Carboidratos/análise , Cromatografia , Cromatografia em Gel , Hexosaminas/análise , Humanos , Imunoeletroforese , Técnicas In Vitro , Peso Molecular , Peptídeos/análise , Fosfatidilcolinas , Polissacarídeos/análise , Proteínas/análise
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