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Toluidine blue O (TBO) is a phenothiazine dye that, due to its photochemical characteristics and high affinity for biomembranes, has been revealed as a new photosensitizer (PS) option for antimicrobial photodynamic therapy (PDT). This points to a possible association with membranous organelles like mitochondrion. Therefore, here we investigated its effects on mitochondrial bioenergetic functions both in the dark and under photostimulation. Two experimental systems were utilized: (a) isolated rat liver mitochondria and (b) isolated perfused rat liver. Our data revealed that, independently of photostimulation, TBO presented affinity for mitochondria. Under photostimulation, TBO increased the protein carbonylation and lipid peroxidation levels (up to 109.40 and 119.87%, respectively) and decreased the reduced glutathione levels (59.72%) in mitochondria. TBO also uncoupled oxidative phosphorylation and photoinactivated the respiratory chain complexes I, II, and IV, as well as the FoF1-ATP synthase complex. Without photostimulation, TBO caused uncoupling of oxidative phosphorylation and loss of inner mitochondrial membrane integrity and inhibited very strongly succinate oxidase activity. TBO's uncoupling effect was clearly seen in intact livers where it stimulated oxygen consumption at concentrations of 20 and 40 µM. Additionally, TBO (40 µM) reduced cellular ATP levels (52.46%) and ATP/ADP (45.98%) and ATP/AMP (74.17%) ratios. Consequently, TBO inhibited gluconeogenesis and ureagenesis whereas it stimulated glycogenolysis and glycolysis. In conclusion, we have revealed for the first time that the efficiency of TBO as a PS may be linked to its ability to photodynamically inhibit oxidative phosphorylation. In contrast, TBO is harmful to mitochondrial energy metabolism even without photostimulation, which may lead to adverse effects when used in PDT.
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Doença Hepática Induzida por Substâncias e Drogas , Mitocôndrias Hepáticas , Ratos , Animais , Mitocôndrias Hepáticas/metabolismo , Cloreto de Tolônio/metabolismo , Cloreto de Tolônio/farmacologia , Metabolismo Energético , Fármacos Fotossensibilizantes/farmacologia , Trifosfato de Adenosina/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismoRESUMO
Bone fractures are an important cause of morbidity and mortality in hemodialysis (HD) patients. The aim of this study was to quantify the incidence of fractures in a cohort of prevalent HD patients and evaluate its relationship with possible risk factors. We performed a retrospective analysis of 341 patients, since they started HD (median of 51 months). Demographic, clinical, and biochemical parameters as well as vascular calcifications (VC) were evaluated. Fifty-seven episodes of fracture were identified with a median HD vintage of 47 months (incidence rate of 31 per 1000 person-years). Age (p < 0.001), female gender (p < 0.001), lower albumin (p = 0.02), and higher VC score (p < 0.001) were independently associated with increased risk of fracture, while active vitamin D therapy (p = 0.03) was associated with decreased risk. A significantly higher risk of incident fracture was also associated with higher values of bone-specific alkaline phosphatase (bALP) (p = 0.01) and intact parathyroid hormone (iPTH) levels either < 300 pg/mL (p = 0.02) or > 800 pg/mL (p < 0.001) compared with 300-800 pg/mL. In conclusion, bone fracture incidence in HD patients is high and its risk increases with age, female gender, lower serum albumin, and with the presence of more VC. Prevalent HD patients with low or high iPTH levels or increased bALP also had a higher fracture risk. Therapy with active vitamin D seems to have a protective role. Assessment of fracture risk and management in dialysis patients at greatest risk requires further study.
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Fraturas Ósseas/epidemiologia , Fraturas Ósseas/etiologia , Diálise Renal/efeitos adversos , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Incidência , Masculino , Análise Multivariada , Hormônio Paratireóideo/sangue , Prevalência , Estudos Retrospectivos , Fatores de Risco , Calcificação Vascular/complicaçõesRESUMO
PURPOSE: (Poly)phenols have been reported to confer protective effects against type 2 diabetes but the precise association remains elusive. This meta-analysis aimed to assess the effects of (poly)phenol intake on well-established biomarkers in people with type 2 diabetes or at risk of developing diabetes. METHODS: A systematic search was conducted using the following selection criteria: (1) human randomized controlled trials involving individuals with prediabetes and type 2 diabetes; (2) one or more of the following biomarkers: glucose, glycated haemoglobin (HbA1c), insulin, pro-insulin, homeostatic model assessment of insulin resistance (HOMA-IR), islet amyloid polypeptide (IAPP)/amylin, pro-IAPP/pro-amylin, glucagon, C-peptide; (3) chronic intervention with pure or enriched mixtures of (poly)phenols. From 488 references, 88 were assessed for eligibility; data were extracted from 27 studies and 20 were used for meta-analysis. The groups included in the meta-analysis were: (poly)phenol mixtures, isoflavones, flavanols, anthocyanins and resveratrol. RESULTS: Estimated intervention/control mean differences evidenced that, overall, the consumption of (poly)phenols contributed to reduced fasting glucose levels (- 3.32 mg/dL; 95% CI - 5.86, - 0.77; P = 0.011). Hb1Ac was only slightly reduced (- 0.24%; 95% CI - 0.43, - 0.044; P = 0.016) whereas the levels of insulin and HOMA-IR were not altered. Subgroup comparative analyses indicated a stronger effect on blood glucose in individuals with diabetes (- 5.86 mg/dL, 95% CI - 11.34, - 0.39; P = 0.036) and this effect was even stronger in individuals taking anti-diabetic medication (- 10.17 mg/dL, 95% CI - 16.59, - 3.75; P = 0.002). CONCLUSIONS: Our results support that the consumption of (poly)phenols may contribute to lower glucose levels in individuals with type 2 diabetes or at risk of diabetes and that these compounds may also act in combination with anti-diabetic drugs.
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Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/sangue , Hipoglicemiantes/uso terapêutico , Fenóis/sangue , Fenóis/uso terapêutico , Biomarcadores/sangue , Terapia Combinada/métodos , Humanos , Polifenóis/sangue , Polifenóis/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: KRAS is an EGFR effector in the RAS/RAF/ERK cascade that is mutated in about 40% of metastatic colorectal cancer (mCRC). Activating mutations in codons 12 and 13 of the KRAS gene are the only established negative predictors of response to anti-EGFR therapy and patients whose tumors harbor such mutations are not candidates for therapy. However, 40 to 60% of wild-type cases do not respond to anti-EGFR therapy, suggesting the involvement of other genes that act downstream of EGFR in the RAS-RAF-MAPK and PI3K-AKT pathways or activating KRAS mutations at other locations of the gene. METHODS: DNA was obtained from a consecutive series of 201 mCRC cases (FFPE tissue), wild-type for KRAS exon 2 (codons 12 and 13). Mutational analysis of KRAS (exons 3 and 4), BRAF (exons 11 and 15), and PIK3CA (exons 9 and 20) was performed by high resolution melting (HRM) and positive cases were then sequenced. RESULTS: One mutation was present in 23.4% (47/201) of the cases and 3.0% additional cases (6/201) had two concomitant mutations. A total of 53 cases showed 59 mutations, with the following distribution: 44.1% (26/59) in KRAS (13 in exon 3 and 13 in exon 4), 18.6% (11/59) in BRAF (two in exon 11 and nine in exon 15) and 37.3% (22/59) in PIK3CA (16 in exon 9 and six in exon 20). In total, 26.4% (53/201) of the cases had at least one mutation and the remaining 73.6% (148/201) were wild-type for all regions studied. Five of the mutations we report, four in KRAS and one in BRAF, have not previously been described in CRC. BRAF and PIK3CA mutations were more frequent in the colon than in the sigmoid or rectum: 20.8% vs. 1.6% vs. 0.0% (P=0.000) for BRAF and 23.4% vs. 12.1% vs. 5.4% (P=0.011) for PIK3CA mutations. CONCLUSIONS: About one fourth of mCRC cases wild-type for KRAS codons 12 and 13 present other mutations either in KRAS, BRAF, or PIK3CA, many of which may explain the lack of response to anti-EGFR therapy observed in a significant proportion of these patients.
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Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Éxons , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Adulto , Sequência de Bases , Classe I de Fosfatidilinositol 3-Quinases , Neoplasias Colorretais/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Taxa de Mutação , Metástase Neoplásica , Técnicas de Amplificação de Ácido Nucleico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras) , Temperatura de Transição , Resultado do TratamentoRESUMO
Social insects are characterized by having a wide diversity of exocrine glands, with highlights for ants with about 85 glands spreading throughout the body. The mandibular and intramandibular glands are associated with the production of pheromones. The army ants (Dorylinae) play an important role in the structure of the invertebrate community because they are efficient predators and provide suitable conditions for various animals following their invasions in the food search. Labidus coecus (Latreille) is an underground-ameliorating ant and Labidus praedator (Smith) is a generalist surface predator which can deplete invertebrate biomass by up to 75%. This work investigated the morphology of the mandibular and intramandibular glands of L. praedator and L. coecus workers. The glands were analyzed by light microscopy, histochemistry, and scanning electron microscopy. The mandibular and intramandibular glands of the two species were classified as class III glands. The data on the morphology of the mandibular glands has revealed that they have characteristics in common with other subfamilies. The intramandibular glands of the two species of Labidus have similar morphology and chemical composition, which indicates that the components of these glands can have the same function despite their different habits.
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Formigas , Animais , Formigas/anatomia & histologia , Invertebrados , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/química , Microscopia Eletrônica de Varredura , BiomassaRESUMO
Hemocytes are cells present in the hemolymph of insects that play a role in combating invasive pathogens, ensuring defense by the immune system in these organisms. While the types of hemocytes are well known in some insect representatives, data on these cells in Hymenoptera are limited to certain bees and wasps, with little information available for ants. Among ants, the genus Atta has environmental and economic importance, forming highly organized colonies consisting of the queen and workers, with the latter subdivided into subcastes: gardeners, waste removers, foragers, and soldiers, which are exposed to different pathogens. This study describes the morphology of hemocytes in the worker subcastes of Atta sexdens rubropilosa. Hemolymph samples from the ant were submitted to light, confocal, and scanning electron microscopy analyses. Five types of hemocytes were identified in the hemolymph of all ant subcastes, including prohemocytes, oenocytoids, spherulocytes, plasmatocytes, and granulocytes. They exhibited nuclei with a predominance of decondensed chromatin. The granulocytes were the most abundant cell type in the subcastes, followed by prohemocytes, plasmatocytes, oenocytoids, and spherulocytes. Phagocytosis assays reveal that plasmatocytes and granulocytes are the main phagocytic cells in all castes evaluated. This study fills an important gap in understanding the immune response in this ant species.
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Formigas , Vespas , Abelhas , Animais , Hemócitos , Hemolinfa , Microscopia Eletrônica de VarreduraRESUMO
Clomipramine, a tricyclic antidepressant used to treat depression and obsessive-compulsive disorder, has been linked to a few cases of acute hepatotoxicity. It is also recognized as a compound that hinders the functioning of mitochondria. Hence, the effects of clomipramine on mitochondria should endanger processes that are somewhat connected to energy metabolism in the liver. For this reason, the primary aim of this study was to examine how the effects of clomipramine on mitochondrial functions manifest in the intact liver. For this purpose, we used the isolated perfused rat liver, but also isolated hepatocytes and isolated mitochondria as experimental systems. According to the findings, clomipramine harmed metabolic processes and the cellular structure of the liver, especially the membrane structure. The considerable decrease in oxygen consumption in perfused livers strongly suggested that the mechanism of clomipramine toxicity involves the disruption of mitochondrial functions. Coherently, it could be observed that clomipramine inhibited both gluconeogenesis and ureagenesis, two processes that rely on ATP production within the mitochondria. Half-maximal inhibitory concentrations for gluconeogenesis and ureagenesis ranged from 36.87 µM to 59.64 µM. The levels of ATP as well as the ATP/ADP and ATP/AMP ratios were reduced, but distinctly, between the livers of fasted and fed rats. The results obtained from experiments conducted on isolated hepatocytes and isolated mitochondria unambiguously confirmed previous propositions about the effects of clomipramine on mitochondrial functions. These findings revealed at least three distinct mechanisms of action, including uncoupling of oxidative phosphorylation, inhibition of the FoF1-ATP synthase complex, and inhibition of mitochondrial electron flow. The elevation in activity of cytosolic and mitochondrial enzymes detected in the effluent perfusate from perfused livers, coupled with the increase in aminotransferase release and trypan blue uptake observed in isolated hepatocytes, provided further evidence of the hepatotoxicity of clomipramine. It can be concluded that impaired mitochondrial bioenergetics and cellular damage are important factors underlying the hepatotoxicity of clomipramine and that taking excessive amounts of clomipramine can lead to several risks including decreased ATP production, severe hypoglycemia, and potentially fatal outcomes.
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Doença Hepática Induzida por Substâncias e Drogas , Clomipramina , Ratos , Animais , Clomipramina/toxicidade , Clomipramina/metabolismo , Metabolismo Energético , Fígado/metabolismo , Mitocôndrias/metabolismo , Trifosfato de Adenosina/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Mitocôndrias Hepáticas/metabolismoRESUMO
A 47-year-old woman with a history of a pulsatile headache, photophobia, dizziness and blurred vision was diagnosed with a massive expansive meningioma and proposed for surgical excision. During surgery, the patient began to show progressive haemodynamic instability with extreme hypotension and severe arrhythmia that only responded to epinephrine. With the continuity of haemodynamic instability, ST segment elevation and great amount of blood loss, the surgery was postponed. The follow-up brain CT scan showed evidence of posterior reversible encephalopathy syndrome and cardiac catheterisation diagnosed as Takotsubo syndrome. The patient remained sedated under aminergic support and was admitted to a cardiac intensive care unit. After clinic stabilisation, the patient underwent two more surgical procedures with special attention paid to monitoring haemodynamic stability, blood loss and cardiac output. After 70 days of admission, the patient was discharged with moderate visual impairment and follow-up consultations in neurosurgery and cardiology.
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Anestésicos , Neoplasias Meníngeas , Meningioma , Síndrome da Leucoencefalopatia Posterior , Feminino , Humanos , Neoplasias Meníngeas/complicações , Neoplasias Meníngeas/cirurgia , Meningioma/complicações , Meningioma/cirurgia , Pessoa de Meia-Idade , Neuroimagem , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Síndrome da Leucoencefalopatia Posterior/etiologiaRESUMO
Introduction: Diabetes is one of the major metabolic diseases worldwide. Despite being a complex systemic pathology, the aggregation and deposition of Islet Amyloid Polypeptide (IAPP), or amylin, is a recognized histopathological marker of the disease. Although IAPP proteotoxicity represents an important trigger of ß-cell dysfunction and ultimately death, its exploitation as a therapeutic tool remains underdeveloped. The bioactivity of (poly)phenols towards inhibition of pathological protein aggregation is well known, however, most of the identified molecules have limited bioavailability. Methods: Using a strategy combining in silico, cell-free and cell studies, we scrutinized a unique in-house collection of (poly)phenol metabolites predicted to appear in the human circulation after (poly)phenols ingestion. Results: We identified urolithin B as a potent inhibitor of IAPP aggregation and a powerful modulator of cell homeostasis pathways. Urolithin B was shown to affect IAPP aggregation pattern, delaying the formation of amyloid fibrils and altering their size and morphology. The molecular mechanisms underlying urolithin B-mediated protection include protein clearance pathways, mitochondrial function, and cell cycle ultimately rescuing IAPP-mediated cell dysfunction and death. Discussion: In brief, our study uncovered urolithin B as a novel small molecule targeting IAPP pathological aggregation with potential to be exploited as a therapeutic tool for mitigating cellular dysfunction in diabetes. Resulting from the colonic metabolism of dietary ellagic acid in the human body, urolithin B bioactivity has the potential to be explored in nutritional, nutraceutical, and pharmacological perspectives.
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Diabetes Mellitus , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Humanos , Cumarínicos/farmacologia , FenóisRESUMO
INTRODUCTION: Langerhans cell histiocytosis (LCH) is a rare heterogeneous disease that normally occurs in children under 15 years but can rarely be diagnosed in adulthood. It can affect any organ of the body, and a less favorable prognosis is expected when either liver, lung, spleen, or bone marrow are affected. Diabetes insipidus, from pituitary dysfunction, is one of the most common consequences that can develop anytime during the disease, and symptoms normally worsen during pregnancy. Pregnancy with this disease is uncommon, and when it occurs, a cesarean section is normally performed. CASE PRESENTATION: We report a 34-year-old pregnant woman (37 weeks and two days gestation) with the diagnosis of a disseminated LCH at the age of 30 who presented herself at the obstetrics emergency department due to respiratory distress. During pregnancy, her pulmonary function remained stable, and she was asymptomatic until the last two days before she was admitted. Labor was induced, with vaginal misoprostol, to achieve a vaginal birth with epidural analgesia. The child was born without complications, and the patient had an immediate clinical improvement. In the following three months, she remained asymptomatic without any worsening of her disease. CONCLUSIONS: In LCH, a cesarean section is the first choice in many cases due to pulmonary impairment. We concluded that early placement of an epidural catheter allows labor analgesia while safeguarding the possibility of an epidural anesthesia in case of urgent/emergent cesarean section. If pulmonary function remains stable, vaginal delivery is possible, thereby being less invasive and allowing for a faster recovery.
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Alzheimer's disease (AD) is a neurodegenerative disorder that affects millions worldwide. Due to population ageing, the incidence of AD is increasing. AD patients develop cognitive decline and dementia, features for which is known, requiring permanent care. This poses a major socio-economic burden on healthcare systems as AD patients' relatives and healthcare workers are forced to cope with rising numbers of affected people. Despite recent advances, AD pathological mechanisms are not fully understood. Nevertheless, it is clear that the amyloid beta (Aß) peptide, which forms amyloid plaques in AD patients' brains, plays a key role. Type 2 diabetes, the most common form of diabetes, affects hundreds of million people globally. Islet amyloid polypeptide (IAPP) is a hormone co-produced and secreted with insulin in pancreatic ß-cells, with a key role in diabetes, as it helps regulate glucose levels and control adiposity and satiation. Similarly to Aß, IAPP is very amyloidogenic, generating intracellular amyloid deposits that cause ß-cell dysfunction and death. It is now clear that IAPP can also have a pathological role in AD, decreasing cognitive function. IAPP harms the blood-brain barrier, directly interacts and co-deposits with Aß, promoting diabetes-associated dementia. IAPP can cause a metabolic dysfunction in the brain, leading to other diabetes-related forms of AD. Thus, here we discuss IAPP association with diabetes, Aß and dementia, in the context of what we designate a "diabetes brain phenotype" AD hypothesis. Such approach helps to set a conceptual framework for future IAPP-based drugs against AD.
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Diabetes remains one of the leading causes of deaths and co-morbidities in the world, with tremendous human, social and economic costs. Therefore, despite therapeutics and technological advancements, improved strategies to tackle diabetes management are still needed. One of the suggested strategies is the consumption of (poly)phenols. Positive outcomes of dietary (poly)phenols have been pointed out towards different features in diabetes. This is the case of ellagitannins, which are present in numerous foodstuffs such as pomegranate, berries, and nuts. Ellagitannins have been reported to have a multitude of effects on metabolic diseases. However, these compounds have high molecular weight and do not reach circulation at effective concentrations, being metabolized in smaller compounds. After being metabolized into ellagic acid in the small intestine, the colonic microbiota hydrolyzes and metabolizes ellagic acid into dibenzopyran-6-one derivatives, known as urolithins. These low molecular weight compounds reach circulation in considerable concentrations ranging until micromolar levels, capable of reaching target tissues. Different urolithins are formed throughout the metabolization process, but urolithin A, isourolithin A, and urolithin B, and their phase-II metabolites are the most frequent ones. In recent years, urolithins have been the focus of attention in regard to their effects on a multiplicity of chronic diseases, including cancer and diabetes. In this review, we will discuss the latest advances about the protective effects of urolithins on diabetes.
Assuntos
Cumarínicos/farmacocinética , Diabetes Mellitus/terapia , Disponibilidade Biológica , Frutas/química , Humanos , Taninos Hidrolisáveis/farmacocinética , Nozes/química , Punica granatum/química , Substâncias ProtetorasRESUMO
BACKGROUND: The present study aimed to characterize the intrinsic and photodynamic effects of azure B (AB) on mitochondrial bioenergetics, as well as the consequences of its intrinsic effects on hepatic energy metabolism. METHODS: Two experimental systems were utilized: (a) isolated rat liver mitochondria and (b) isolated perfused rat liver. RESULTS: AB interacted with mitochondria regardless of photostimulation, but its binding degree was reduced by mitochondrial energization. Under photostimulation, AB caused lipid peroxidation and protein carbonylation and decreased the content of reduced glutathione (GSH) in mitochondria. AB impaired mitochondrial bioenergetics in at least three distinct ways: (1) uncoupling of oxidative phosphorylation; (2) photoinactivation of complexes I and II; and (3) photoinactivation of the FoF1-ATP synthase complex. Without photostimulation, AB also demonstrated mitochondrial toxicity, which was characterized by the induction of lipid peroxidation, loss of inner mitochondrial membrane integrity, and uncoupling of oxidative phosphorylation. The perfused rat liver experiments showed that mitochondria were one of the major targets of AB, even in intact cells. AB inhibited gluconeogenesis and ureagenesis, two biosynthetic pathways strictly dependent on intramitochondrially generated ATP. Contrariwise, AB stimulated glycogenolysis and glycolysis, which are required compensatory pathways for the inhibited oxidative phosphorylation. Similarly, AB reduced the cellular ATP content and the ATP/ADP and ATP/AMP ratios. CONCLUSIONS: Although the properties and severe photodynamic effects of AB on rat liver mitochondria might suggest its usefulness in PDT treatment of liver tumors, this possibility should be considered with precaution given the toxic intrinsic effects of AB on mitochondrial bioenergetics and energy-linked hepatic metabolism.
Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes , Trifosfato de Adenosina/metabolismo , Animais , Corantes Azur , Metabolismo Energético , Fígado , Mitocôndrias/metabolismo , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Ratos , Ratos WistarRESUMO
Diabetes affects hundreds of millions of patients worldwide. Despite the advances in understanding the disease and therapeutic options, it remains a leading cause of death and of comorbidities globally. Islet amyloid polypeptide (IAPP), or amylin, is a hormone produced by pancreatic ß-cells. It contributes to the maintenance of glucose physiological levels namely by inhibiting insulin and glucagon secretion as well as controlling adiposity and satiation. IAPP is a highly amyloidogenic polypeptide forming intracellular aggregates and amyloid structures that are associated with ß-cell death. Data also suggest the relevance of unprocessed IAPP forms as seeding for amyloid buildup. Besides the known consequences of hyperamylinemia in the pancreas, evidence has also pointed out that IAPP has a pathological role in cognitive function. More specifically, IAPP was shown to impair the blood-brain barrier; it was also seen to interact and co-deposit with amyloid beta peptide (Aß), and possibly with Tau, within the brain of Alzheimer's disease (AD) patients, thereby contributing to diabetes-associated dementia. In fact, it has been suggested that AD results from a metabolic dysfunction in the brain, leading to its proposed designation as type 3 diabetes. Here, we have first provided a brief perspective on the IAPP amyloidogenic process and its role in diabetes and AD. We have then discussed the potential interventions for modulating IAPP proteotoxicity that can be explored for therapeutics. Finally, we have proposed the concept of a "diabetes brain phenotype" hypothesis in AD, which may help design future IAPP-centered drug developmentstrategies against AD.
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Diabetes is a major public health issue that has attained alarming levels worldwide. Pancreatic aggregates of human islet amyloid polypeptide (IAPP) represent a major histopathological hallmark of type 2 diabetes. IAPP is expressed in ß-cells as pre-pro-IAPP (ppIAPP) that is first processed to pro-IAPP (pIAPP) and finally to its mature form (matIAPP), being released upon glucose stimulation together with insulin. Impairment and overload of the IAPP processing machinery seem to be associated with the accumulation of immature IAPP species and the formation of toxic intracellular oligomers, which have been associated with ß-cell dyshomeostasis and apoptosis. Nevertheless, the pathological importance of these immature IAPP forms for the assembly and cytotoxicity of these oligomers is not completely understood. Here, we describe the generation and characterization of unprecedented Saccharomyces cerevisiae models recapitulating IAPP intracellular oligomerization. Expression of green fluorescent protein (GFP) fusions of human ppIAPP, pIAPP, and matIAPP proved to be toxic in yeast cells at different extents, with ppIAPP exerting the most deleterious effect on yeast growth and cell viability. Although expression of all IAPP constructs induced the formation of intracellular aggregates in yeast cells, our data point out the accumulation of insoluble oligomeric species enriched in immature ppIAPP as the trigger of the high toxicity mediated by this construct in cells expressing ppIAPP-GFP. In addition, MS/MS analysis indicated that oligomeric species found in the ppIAPP-GFP lysates contain the N-terminal sequence of the propeptide fused to GFP. These models represent powerful tools for future research focused on the relevance of immature forms in IAPP-induced toxicity. Furthermore, they are extremely useful in high-throughput screenings for genetic and chemical modulators of IAPP aggregation.
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Malignant melanoma (MM) arising primarily in the cervix is exceedingly rare and has a poor prognosis. We report the case of a primary MM of the cervix in a 64-year-old woman with vaginal bleeding. She presented with a cervical amelanotic lesion which on biopsy rendered the diagnosis of MM. The patient was staged as International Federation of Gynecology and Obstetrics IIB and underwent Wertheim-Meigshysterectomy followed by brachytherapy. One year later, she was diagnosed with a large pelvic relapse for which surgery was performed. She then presented with a vaginal relapse and an isolated hepatic lesion, both of which were proposed for surgery. The diagnosis of MM of the cervix is a clinical and pathological challenge due to its rarity and overlapping features. Cytology cannot accurately diagnose it. Moreover, amelanotic MMs must be distinguished from other poorly differentiated carcinomas by diagnosis that ultimately relies on immunohistochemical staining. Radical surgery is the only treatment showing predictive benefit.
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Melanoma/diagnóstico , Melanoma/terapia , Recidiva Local de Neoplasia/cirurgia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/terapia , Braquiterapia , Feminino , Humanos , Histerectomia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Pelve/patologia , Pelve/cirurgia , Doenças Raras , Resultado do Tratamento , Vagina/patologia , Vagina/cirurgiaRESUMO
We have analysed, at the hematological and molecular level, 51 Hb lepore heterozygotes and three compound heterozygotes for Hb Lepore and HbS (HbLep/HbS) in 26 unselected Portuguese families. The Lepore Boston variant was present in one family, in association with classical haplotype V. All of the other Lepore alleles present haplotype III in association with XmnI (+)5' of (G)gamma gene, in tight linkage disequilibrium to the major mutation found in the Portuguese population, the Lepore Baltimore variant ( delta(68Leu)-beta(84Thr)). The three compound heterozygotes are the first HbLep/HbS individuals reported in the literature, with the Lepore Baltimore mutation linked to haplotype III. In agreement with other studies, these Lepore Baltimore heterozygotes have higher HbF (1.4-14.1% of total hemoglobin) than published cases of Lepore Boston (0.8-5.4%), which is associated with XmnI(-). Among the Lepore Baltimore heterozygotes, the (AT)xTy repeat region at -540 bp of the beta globin gene in trans to the Lepore chromosome, can account for much of the variability in HbF level. The allele (AT)7T7 is associated with lower HbF, and (AT)9T5 is associated with higher HbF. As we previously reported for beta thalassemic carriers, we observe in Lepore Baltimore carriers an effector in trans, linked to the (AT)xTy sequence, acting as an HPFH (Hereditary Persistence of Fetal Hemoglobin) determinant.
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Hemoglobina Fetal/análise , Globinas/genética , Hemoglobina Falciforme/genética , Hemoglobinas Anormais/genética , Heterozigoto , Mutação , Adolescente , Adulto , DNA/análise , Enzimas de Restrição do DNA/metabolismo , Haplótipos , Hemoglobina A2/análise , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Traço Falciforme/sangue , Traço Falciforme/complicações , Traço Falciforme/genéticaRESUMO
Os autores apresentam um relato sobre a implantaçäo, bem como a descriçäo do primeiro ano de funcionamento, de um hospital-dia da cidade de Campinas - SP - Brasil, constituinte do serviço público municipal, e sem vinculaçäo universitária. Seu objetivo inicial era atender uma demanda dupla: evitar internaçöes e realizar um trabalho de reabilitaçäo (em sentido lato). No presente estudo, säo discutidas desde questöes mais amplas, como o posicionamento (fluxograma) desse hospital-dia no sistema de saúde da regiäo, até aquelas concernentes à sua organizaçäo interna. Salienta-se a interdisciplinaridade do trabalho em equipe, näo existindo exclusividade de funçöes entre os diversos profissionais. Dados sócio-demográficos e psicopatológicos da populaçäo atendida no período säo apresentados, visando uma análise da vinculaçäo dos pacientes ao serviço, e da efetividade do tratamento. O resultado do tratamento dos pacientes crônicos foi superior. Evidenciou-se ainda a necessidade de uma rede mais complexa (pronto-socorro, leitos noturnos näo hospitalares) para lidar com a demanda familiar de internaçäo dos pacientes agudos. Finalmente, ressaltamos a importância da experiência enquanto espaço crítico de discussäo, havendo sempre uma tentativa de traduçäo do trabalho em termos conceituais, e principalmente de seu registro, visando futuras replicaçöes. Sobretudo, a convicçäo da equipe de que a discussäo ideológica, embora essencial às práticas mais inovadoras, näo substitui uma avaliaçäo técnica do projeto
Assuntos
Humanos , Masculino , Feminino , Adulto , Serviços de Saúde Mental/organização & administração , Alcoolismo/terapia , Hospitais Municipais , Equipe de Assistência ao Paciente , Transtornos Neuróticos/terapia , Transtornos Psicóticos/terapiaRESUMO
Os autores revisam a literatura psiquiatríca recente (últimos cinco anos) a respeito da hospitalizaçäo parcial, e especialmente, de hospital-dia. Uma discussäo crítica da mesma é realizada enfatizando diversos aspectos: definiçäo em termos conceituais, possíveis modelos organizacionais, populaçäo alvo, e princípios do atendimento. Consideraçöes de ordem metodológica säo formuladas com o intuito de explicar a impossibilidade de generalizaçäo dos resultados obtidos pela maioria dos estudos mencionados. Além disso, säo examinadas as incidências desses dados sobre a atual situaçäo brasileira de atençäo à saúde mental, particularmente em questöes de planejamento. Finalmente, os autores, tendo em conta ainda a experiência relatada em outro texto, apontam: 1- o risco de subutilizaçäo de um hospital-dia em nosso meio face à arraigada cultura de internaçäo presente; 2- a necessidade do hospital-dia estar integrado a um sistema organizado de atençäo; e 3- alguns requisitos para um funcionamento eficaz do hospital-dia, sendo estes distintos conforme a populaçäo-alvo predominante seja constituída de pacientes agudos ou crônicos