RESUMO
Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programmes that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of 'assisting only'. In Rwanda, Team Heart, a US and Rwanda-based non-governmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, its 'Seal of Approval' for the sustainability of endorsed programmes in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programmes could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Sociedades Médicas , Cirurgia Torácica , Humanos , Sociedades Médicas/organização & administração , Cirurgia Torácica/organização & administração , Países em Desenvolvimento , Saúde GlobalRESUMO
Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programs that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of "assisting only." In Rwanda, Team Heart, a US and Rwanda-based non-governmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, its "Seal of Approval" for the sustainability of endorsed programs in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programs could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Sociedades Médicas , Cirurgia Torácica , Humanos , Países em Desenvolvimento , Saúde GlobalRESUMO
Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programs that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of "assisting only." In Rwanda, Team Heart, a US and Rwanda-based nongovernmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, its "Seal of Approval" for the sustainability of endorsed programs in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programs could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Sociedades Médicas , Humanos , Países em Desenvolvimento , Cirurgia Torácica/organização & administração , Cirurgia Torácica/educação , Cooperação Internacional , Acessibilidade aos Serviços de Saúde/organização & administração , Comportamento CooperativoRESUMO
SUMMARY: Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programmes that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of 'assisting only'. In Rwanda, Team Heart, a US and Rwanda-based non-governmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, it's 'Seal of Approval' for the sustainability of endorsed programmes in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programmes could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Países em Desenvolvimento , Sociedades Médicas , Humanos , Fortalecimento Institucional/organização & administração , Comportamento Cooperativo , Acessibilidade aos Serviços de Saúde/organização & administração , Necessidades e Demandas de Serviços de Saúde/organização & administração , Disparidades em Assistência à Saúde , Cooperação Internacional , Sociedades Médicas/organização & administração , Cirurgia Torácica/organização & administração , Cirurgia Torácica/educação , Fatores de TempoRESUMO
Spontaneous depolarizations around the core are a consistent feature of focal cerebral ischemia, but the associated regional hemodynamic changes are heterogeneous. We determined how the features of depolarizations relate to subsequent cerebral blood flow (CBF) changes in global forebrain ischemia. Forebrain ischemia was produced in halothane-anesthetized rats (n=13) by common carotid artery occlusion and hypovolemic hypotension. Mean arterial blood pressure (MABP) was monitored via a femoral catheter. Specific illuminations allowed the capture of image sequences through a cranial window to visualize: changes in membrane potential (voltage-sensitive dye method); CBF (laser speckle contrast imaging); cerebral blood volume (intrinsic optical signal, IOS at 540-550nm); and hemoglobin deoxygenation (IOS at 620-640nm). A depolarization occurred (n=9) when CBF fell below 43.4±5% of control (41±4mmHg MABP), and propagated with a distinct wave front at a rate of 2.8mm/min. Depolarizations were either persistent (n=4), intermediate (n=3) or short, transient depolarization (n=2). Persistent and intermediate depolarizations were associated with sustained hypoperfusion (-11.7±5.1%) and transient hypoperfusion (-17.4±5.2, relative to CBF before depolarization). Short, transient depolarizations did not generate clear CBF responses. Depolarizations during incomplete global ischemia occurred at the lower limit of CBF autoregulation, propagated similar to spreading depolarization (SD), and the hemodynamic responses indicated inverse neurovascular coupling. Similar to SDs associated with focal stroke, the propagating event can be persistent or transient.
Assuntos
Isquemia Encefálica/fisiopatologia , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/fisiopatologia , Animais , Pressão Arterial , Hemodinâmica , Masculino , Potenciais da Membrana/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
Previous studies have confirmed that the phase transition of vesicular gels of hydrogenated phospholipids to the less ordered fluid vesicular state was induced by the increase of the beta-sitosterol ratio in the whole gel system and consequently in the lipid bilayer. The purpose of the present study was to evaluate the influence of the beta-sitosterol portion in the lipid bilayer and the effect of high pressure homogenization on the structural characteristics of the prepared gel systems. In addition the influence of beta-sitosterol on the consequent chlorhexidine release from the obtained vesicles and liposomes was also examined. Lipid mixtures were prepared from different molar ratios of lecithin:sterol components (90:10-65:35 mol%). The obtained mixtures were hydrated with the aqueous solution of chlorhexidine digluconate in order to achieve a 30% (w/w) final concentration of the lipid mixtures and a 4% (w/w) concentration of the drug. One portion of the resultant multilamellar vesicles was homogenized by using high pressure. To characterize the homogenized and non-homogenized systems, transmission electron microscopy of the freeze-fractured samples and differential scanning calorimetry (DSC) were carried out. A vertical type diffusion cell was applied to determine the amount of released chlorhexidine digluconate. Along with the increase in beta-sitosterol concentration, the fluidity of the membrane as well as its permeability also increased. The increased permeability--caused by the higher beta-sitosterol concentration--and the high pressure homogenization, which increased the dispersity and therefore the surface area, enabled a higher amount of chlorhexidine to be released. The increase of drug release was more pronounced in the case of samples prepared with high pressure homogenization.
Assuntos
Anti-Infecciosos Locais/química , Clorexidina/química , Composição de Medicamentos/métodos , Hipolipemiantes/química , Lipossomos , Sitosteroides/química , Varredura Diferencial de Calorimetria , Preparações de Ação Retardada , Géis , Bicamadas Lipídicas/química , Microscopia Eletrônica de TransmissãoRESUMO
Structural and functional MRI was used in conjunction with computerized electron microscopy morphometry to study changes 2 h, 24 h and 3 days after 4-aminopyridine-induced seizures lasting 2 h in rats. T2 (relaxation time) values showed changes throughout the cerebral cortex, hippocampus, amygdala and medial thalamus, with a different temporal progression, showing a complete recovery only after 3 days. Two hours after seizures, the apparent diffusion coefficient was decreased throughout the brain compared to control animals, and a further decrease was evident 24 h after seizures. This was followed by a complete recovery at 3 days post-seizures. Functional MRI was performed using regional cerebral blood volume (rCBV) maps. The rCBV was increased shortly after convulsions (2 h) in all structures investigated, with a significant return to baseline values in the parietal cortex and hippocampus, but not in the medial thalamic nuclei, 24 h after seizure onset. No rCBV alterations were detected 3 days after seizures. Electron microscopy of tissue samples of parietal neocortex and hippocampus revealed prominent astrocytic swelling 2 h post-convulsions which decreased thereafter gradually. In conclusion, this experiment reports for the first time structural and functional brain alterations, lasting several hours, in 4-aminopyridine-treated rats after seizure onset. MRI approach combined with histological and ultrastructural analysis provided a clarification of the mechanisms involved in the brain acute response to ictal activity.
Assuntos
4-Aminopiridina , Encéfalo/patologia , Epilepsia/patologia , Imageamento por Ressonância Magnética/métodos , Bloqueadores dos Canais de Potássio , Tonsila do Cerebelo/patologia , Tonsila do Cerebelo/fisiopatologia , Animais , Astrócitos/patologia , Astrócitos/ultraestrutura , Encéfalo/fisiopatologia , Mapeamento Encefálico , Imagem de Difusão por Ressonância Magnética/métodos , Epilepsia/induzido quimicamente , Epilepsia/fisiopatologia , Hipocampo/patologia , Hipocampo/fisiopatologia , Masculino , Microscopia Eletrônica , Lobo Parietal/patologia , Lobo Parietal/fisiopatologia , Células Piramidais/patologia , Células Piramidais/ultraestrutura , Ratos , Ratos Wistar , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia , Tálamo/patologia , Tálamo/fisiopatologiaRESUMO
The transfer through a membrane of the main organic components and mineral elements of Carum carvi and Foeniculum vulgare volatile oils was studied. The transfer was studied from buffer solution pH 1.1 (stomach) and pH 6.5 (intestine) to pH 7.5 (plasma) in a Sartorius model. The transferred components were measured by GC-MS for volatile components and ICP-OES for inorganic elements. The main components (trans-anethole and fenchone from F. vulgare, carvone and D-limonene from C. carvi), as well as some mineral elements (Ca, Mg, S, Zn), transferred through the membrane.
Assuntos
Carum , Foeniculum , Mucosa Gástrica/metabolismo , Mucosa Intestinal/metabolismo , Fitoterapia , Óleos de Plantas/farmacocinética , Cromatografia Gasosa-Espectrometria de Massas , HumanosRESUMO
Previous studies confirm that beta-sitosterol is very effective in altering the molecular packing of soybean lecithin bilayers even more than the cholesterol. The primary aim of the present study was to evaluate the influence of the beta-sitosterol portion in the lipid bilayer on the physical-chemical characteristics of the prepared gel systems, and its influence on the consequent drug release from the liposomes obtained from vesicular phospholipid gels (VPG-s) by redispersion. VPG-s were prepared of different molar ratios of lecithin:sterol components (10:90-35:65 mol%). The mixture was hydrated with the aqueous solution of chlorhexidin digluconate in order to achieve 30% (w/w) final concentration of the lipid mixtures and 4% (w/w) concentration of the drug in each homogenized VPG sample. To characterize the obtained VPG systems optical microscopic examinations using polarized light, differential scanning calorimetry (DSC), photon correlation spectroscopy (PCS), and dynamic surface tension measurements were carried out. Vertical type diffusion cell was applied to determine the amount of released chlorhexidine digluconate. As a result of the surface tension-decreasing effect of beta-sitosterol, the membrane deformability and the dispersity of the system increased. The increased dispersity and fluidity significantly increased the extent of released chlorhexidine from the vesicles.
Assuntos
Clorexidina/química , Lipossomos/química , Sitosteroides/química , Clorexidina/farmacologia , Géis , Lipossomos/farmacologia , Sitosteroides/farmacologia , Solubilidade/efeitos dos fármacos , Propriedades de Superfície/efeitos dos fármacosRESUMO
Indications for sentinel lymph node mapping (SLNM) for patients with ductal carcinoma in situ (DCIS) of the breast are controversial. We reviewed our institutional experience with SLNM for DCIS to determine the node positive rate and clarify indications for nodal staging in patients with DCIS. Since 1998 we have used SLNM to stage breast cancer patients using both blue dye and radiocolloid. In DCIS patients, SLNM has been reserved for patients considered at high risk for harboring coexistent invasive carcinoma or treated by mastectomy. All sentinel nodes were evaluated with serial sectioning, hematoxylin and eosin staining, and immunohistochemical evaluation for cytokeratins. We identified 44 patients with 46 cases of DCIS (two patients with bilateral disease). SLNM identified at least one sentinel node in all cases. In all cases, the sentinel node(s) were negative for axillary metastasis. We calculated the binomial probability of observing 0 of 46 cases as negative when the expected incidence according to published reports in the surgical literature was 13 per cent and found a P value of <0.01. Based on this case-series observation, we conclude SLNM should not be routinely performed for patients with DCIS. We now use SLNM only for DCIS patients treated by mastectomy.
Assuntos
Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Biópsia de Linfonodo Sentinela/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de NeoplasiasRESUMO
OBJECTIVES: To determine whether patients with rheumatoid arthritis (RA) express humoral immunity to the small proteoglycans biglycan and decorin and to compare the response to that of patients suffering from other joint diseases. METHODS: Serum and synovial fluid IgG and IgM antibody levels were determined by enzyme-linked immunosorbent assay. Antibodies to biglycan and decorin as well as to other known and extensively investigated cartilage matrix components such as type II collagen, aggrecan and fibronectin were investigated. Patients suffering from RA, osteoarthritis (OA), psoriatic arthritis and other seronegative spondylarthropathies were included in the study. Correlation between antibody levels and clinical/laboratory parameters was determined. RESULTS: Patients with RA expressed an increased humoral immunity to biglycan, while patients with seronegative spondylarthropathies displayed elevated decorin-specific synovial antibody levels compared with OA patients. CONCLUSION: These results indicate a significantly higher immunity to small proteoglycans in RA and seronegative spondylarthropathies than in OA suggesting a possible involvement in the pathogenesis of inflammatory rheumatic diseases.
Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/análise , Proteoglicanas/imunologia , Líquido Sinovial/imunologia , Adulto , Idoso , Artrite Psoriásica/imunologia , Autoantígenos/imunologia , Biglicano , Cartilagem Articular/imunologia , Decorina , Ensaio de Imunoadsorção Enzimática , Proteínas da Matriz Extracelular , Feminino , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Masculino , Pessoa de Meia-Idade , Osteoartrite/imunologia , Espondiloartropatias/imunologiaRESUMO
BACKGROUND AND AIMS: The optimal treatment of clinically negative inguinal lymph nodes in patients with primary anal cancer has not yet been clearly defined. The presence of metastases in the inguinal lymph nodes is an adverse prognostic factor for anal cancer. In the present study the feasibility of sentinel lymph node biopsy (SLNB) for staging anal cancer was investigated. PATIENTS AND METHODS: From September 1999 to March 2002, 8 patients with biopsy proven primary anal cancer underwent lymphoscintigraphy and dual-agent guided inguinal SLNB for nodal staging before starting multimodality treatment. RESULTS: Inguinal SLNB was successful in all 8 patients (13 groins). A total of 20 hot and blue SLNs (mean 1,5 (1-2) per groins) were removed. In 2 patients (25%) the SLN was positive for metastasis. CONCLUSIONS: Lymphoscintigraphy followed by dual-agent guided inguinal SLNB is technically feasible for staging patients with primary anal cancer. The detection of metastases in the removed sentinel lymph node(s) may alter the treatment and thus may improve the locoregional control and overall survival of these patients.
Assuntos
Neoplasias do Ânus/patologia , Carcinoma de Células Escamosas/patologia , Biópsia de Linfonodo Sentinela , Idoso , Estudos de Viabilidade , Feminino , Virilha , Humanos , Metástase Linfática/diagnóstico , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/métodosRESUMO
Both toxicity and penicillin productivity of the hydroxylated derivatives of phenylacetic acid (PA) and phenoxyacetic acid (POA) were highly dependent on the position of hydroxylation on the aromatic ring in Penicillium chrysogenum. Hydroxylation at position 2 diminished penicillin production but the compounds retained most of their toxicity. On the other hand, hydroxylation at position 4 resulted in barely toxic derivatives with still significant penicillin productivity. 3-Hydroxy-PA was a weak side-chain precursor with considerably reduced toxicity. The activity of the glutathione-dependent detoxification pathway correlated well with the toxicity of the compounds but there was no correlation between acidity, toxicity and penicillin productivity.
Assuntos
Acetatos/metabolismo , Glutationa/metabolismo , Penicilinas/biossíntese , Penicillium chrysogenum/metabolismo , Fenilacetatos/metabolismo , Acetatos/toxicidade , Hidroxilação , Testes de Sensibilidade Microbiana , Penicillium chrysogenum/crescimento & desenvolvimento , Fenilacetatos/toxicidadeRESUMO
An elderly female patient was admitted and operated on for a lesion in the upper lobe of the right lung. After lobectomy the patient has recovered without complications. Histology proved oncocyter carcinoid tumour. This neuro-endocrine tumour is a rarity in the lungs with less than forty cases reported in the reviewed literature. This is the first case reported in Hungary.
Assuntos
Tumor Carcinoide/cirurgia , Neoplasias Pulmonares/cirurgia , Idoso , Tumor Carcinoide/diagnóstico por imagem , Tumor Carcinoide/patologia , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , RadiografiaRESUMO
The aging of the central nervous system and the development of incapacitating neurological diseases like Alzheimer's disease (AD) are generally associated with a wide range of histological and pathophysiological changes eventually leading to a compromised cognitive status. Although the diverse triggers of the neurodegenerative processes and their interactions are still the topic of extensive debate, the possible contribution of cerebrovascular deficiencies has been vigorously promoted in recent years. Various forms of cerebrovascular insufficiency such as reduced blood supply to the brain or disrupted microvascular integrity in cortical regions may occupy an initiating or intermediate position in the chain of events ending with cognitive failure. When, for example, vasoconstriction takes over a dominating role in the cerebral vessels, the perfusion rate of the brain can considerably decrease causing directly or through structural vascular damage a drop in cerebral glucose utilization. Consequently, cerebral metabolism can suffer a setback leading to neuronal damage and a concomitant suboptimal cognitive capacity. The present review focuses on the microvascular aspects of neurodegenerative processes in aging and AD with special attention to cerebral blood flow, neural metabolic changes and the abnormalities in microvascular ultrastructure. In this context, a few of the specific triggers leading to the prominent cerebrovascular pathology, as well as the potential neurological outcome of the compromised cerebral microvascular system are also going to be touched upon to a certain extent, without aiming at total comprehensiveness. Finally, a set of animal models are going to be presented that are frequently used to uncover the functional relationship between cerebrovascular factors and the damage to neural networks.
Assuntos
Envelhecimento/fisiologia , Doença de Alzheimer/patologia , Encéfalo/irrigação sanguínea , Circulação Cerebrovascular/fisiologia , Envelhecimento/metabolismo , Envelhecimento/patologia , Doença de Alzheimer/metabolismo , Animais , Membrana Basal/metabolismo , Membrana Basal/patologia , Membrana Basal/ultraestrutura , Barreira Hematoencefálica/fisiologia , Encéfalo/patologia , Capilares/metabolismo , Capilares/patologia , Capilares/ultraestrutura , Fibras Colinérgicas/metabolismo , Cognição/fisiologia , Humanos , Aprendizagem/fisiologia , Microcirculação/metabolismo , Microcirculação/patologia , Microcirculação/ultraestruturaRESUMO
Interaction between iron(II) and acetohydroxamic acid (Aha), alpha-alaninehydroxamic acid (alpha-Alaha), beta-alaninehydroxamic acid (beta-Alaha), hexanedioic acid bis(3-hydroxycarbamoyl-methyl)amide (Dha) or desferrioxamine B (DFB) under anaerobic conditions was studied by pH-metric and UV-Visible spectrophotometric methods. The stability constants of complexes formed with Aha, alpha-Alaha, beta-Alaha and Dha were calculated and turned out to be much lower than those of the corresponding iron(II) complexes. Stability constants of the iron(II)-hydroxamate complexes are compared with those of other divalent 3d-block metal ions and the Irving-Williams series of stabilities was found to be observed. Above pH 4, in the reactions between iron(II) and desferrioxamine B, the oxidation of the metal ion to iron(III) by the ligand was found. The overall reaction that resulted in the formation of the tris-hydroxamato complex [Fe(HDFB)]+ and monoamide derivative of DFB at pH 6 is: 2Fe2+ + 3H4DFB+ = 2[Fe(HDFB)]+ + H3DFB-monoamide+ + H2O + 4H+. Based on these results, the conclusion is that desferrioxamine B can uptake iron in iron(III) form under anaerobic conditions.
RESUMO
Chronic hypertension during aging is a serious threat to the cerebral vasculature. The larger brain arteries can react to hypertension with an abnormal wall thickening, a loss of elasticity and a narrowed lumen. However, little is known about the hypertension-induced alterations of cerebral capillaries. The present study describes ultrastructural alterations of the cerebrocortical capillary wall, such as thickening and collagen accumulation in the basement membrane of aging spontaneously hypertensive stroke-prone rats. The ratio of cortical capillaries with such vascular pathology occurred significantly more frequently in hypertensive animals. Nimodipine and nifedipine are potential drugs to decrease blood pressure in hypertension but their beneficial effects in experimental studies reach beyond the control of blood pressure. Nimodipine and nifedipine can alleviate ischemia-related symptoms and improve cognition. These drugs differ in that nifedipine, but not nimodipine reduces blood pressure at the here-used concentration while both drugs can penetrate the blood-brain barrier. Here we show that chronic treatment of aging hypertensive stroke-prone rats with nimodipine or nifedipine could preserve microvascular integrity in the cerebral cortex.
Assuntos
Envelhecimento/patologia , Bloqueadores dos Canais de Cálcio/farmacologia , Circulação Cerebrovascular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/patologia , Nimodipina/farmacologia , Animais , Comportamento Animal , Pressão Sanguínea , Canais de Cálcio Tipo L/metabolismo , Capilares/efeitos dos fármacos , Capilares/patologia , Capilares/ultraestrutura , Ingestão de Líquidos , Ingestão de Alimentos , Comportamento Exploratório , Masculino , Microscopia Eletrônica , Nifedipino/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologiaRESUMO
The aim of this study was to investigate the influence of three chlorhexidine species, chlorhexidine base and its salts (diacetate and digluconate), on the physico-chemical features of liquid crystalline systems and on drug transport through lipophilic membranes. Nonionic surfactant, Synperonic A7 (PEG(7)-C(13--15)) was selected for the preparation of the liquid crystalline systems. Mixtures of different ratios of Synperonic A7 and water were prepared. The liquid crystalline systems were characterized using polarizing microscopy, small-angle neutron scattering and transmission electron microscopy. Membrane transport was also examined. The addition of chlorhexidine species to the liquid crystalline system modified the structure of the liquid crystalline system. As a result of liquid crystal--drug interaction, the solubility of chlorhexidine base and its diffusion through lipophilic membranes increased in comparison with those of the chlorhexidine salts.
Assuntos
Clorexidina/química , Fenômenos Químicos , Físico-Química , Cristalização , Membranas Artificiais , Microscopia Eletrônica , Microscopia de Polarização , Nêutrons , Espalhamento de Radiação , Solubilidade , Espectrofotometria UltravioletaRESUMO
In this study the nodal staging sensitivity of sentinel lymph node biopsy (SLNB) with detailed pathological and molecular biological examination has been investigated and compared to that of axillary lymph node dissection (ALND) with routine histological evaluation. Sentinel lymph nodes (SLNs) were removed by the dual-agent injection technique in 68 patients with primary, clinically node-negative breast cancer. Forty-seven patients had negative SLNs according to hematoxylin and eosin (H&E) staining. These H&E-negative SLNs were serially sectioned and examined at 250 microm levels by anticytokeratin immunohistochemistry (IHC). In 14 patients the SLNs were also investigated by cytokeratin 20 (CK20) reverse transcriptase polymerase chain reaction (RT-PCR). SLNB with IHC increased the node-positive rate by 26% (by 40% in tumors less than or equal to 2 cm in size (pT1) and by 9% in tumors more than 2 cm but less than or equal to 5 cm in size (pT2)). The sensitivity of SLNB with IHC was superior to that of ALND with routine histology in pT1 tumors and identical in pT2 tumors. The concordance between histology and RT-PCR was only 21%, and in two of three cases with positive histological results RT-PCR was negative. In conclusion, SLNB with detailed pathological and/or molecular biological evaluation can improve the sensitivity of regional staging. ALND can probably be abandoned in patients with pT1 SLN-negative breast cancer. Further prospective studies are required to determine the clinical significance of these detailed SLN evaluation techniques, but at present these methods are still investigational.
Assuntos
Neoplasias da Mama/patologia , Proteínas de Filamentos Intermediários/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Biópsia de Linfonodo Sentinela , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imuno-Histoquímica , Proteínas de Filamentos Intermediários/análise , Queratina-20 , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de NeoplasiasRESUMO
The aim of the thesis was to examine liquid crystalline gel systems as novel, locally applied drug delivery systems. For developing liquid crystalline vehicle, different ratio of Synperonic A7--water mixtures was prepared. Chlorhexidine, chlorhexidine acetate and chlorhexidine gluconate were used as model drugs. Liquid crystalline structure, drug release and drug release kinetic of the samples were studied at increasing surfactant concentration and the effect of the different drugs on the physicochemical properties of the samples and on the membrane transport was examined. For the analysis of the prepared liquid crystalline systems polarising microscopy, rheology test, differential scanning calorimetry, small-angle neutron scattering and transmission electron microscopy were carried out. The drug release and membrane transport experiments were performed by Franz type vertical diffusion cell and Sartorius Resorptionsmodell apparatus. According to our results liquid crystalline vehicles of lamellar and hexagonal structure formed by increasing the surfactant concentration. The drug release studies indicated, that the kinetic of the release strongly depend on the liquid crystalline structure, zero order release occurs from hexagonal structures and anomalous transport occurs from lamellar structures. The addition of chlorhexidine species to the systems modified the structure of the liquid crystalline system. As a results of liquid crystal-drug interaction the solubility of chlorhexidine base and its diffusion through lipophilic membranes increased in comparison with those of the chlorhexidine salts.