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1.
Surg Endosc ; 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39313583

RESUMO

INTRODUCTION: Diffuse-type gastric carcinoma in an aggressive form of gastric cancer. Surgery is the only potentially curative treatment. It is controversial whether patients with diffuse-type gastric carcinoma should undergo total or subtotal gastrectomy when feasible. The aim of this study is to analyze the oncologic outcomes and overall survival of patients diagnosed with distal diffuse-type gastric cancer undergoing subtotal versus total gastrectomy with curative intent. METHODS: This retrospective study included all patients with histologically confirmed diffuse-type distal gastric carcinoma and clinical staging cT1-4M0, who underwent surgery with curative intent between 2011 and 2020 in a Tertiary Referral Hospital in Chile. Clinical and pathological staging was conducted using the 8th Edition of the American Joint Committee on Cancer Classification. STG group was comprised by patients who underwent subtotal gastrectomy and TG group by patients who underwent total gastrectomy. Both groups were compared in relation to sociodemographic variables, pathology reports and perioperative data which were obtained from electronic medical records. Data analysis was obtained with Stata 16.1 Statistical Software. RESULTS: One hundred and thirty patients underwent curative intent surgery. Subtotal gastrectomy with D2-lymphadenectomy was completed in 68 patients (52%). An R0 resection was achieved in all patients. Median number of resected lymph nodes, tumor size, proximal margin and depth of invasion were similar in both groups. Pathologic staging was similar between both groups, the most frequent being Stage 3(54%). After a median follow-up of 47 months [0.3-157], no difference was observed in overall survival between both groups (5-year-OS 63% in STG group versus 51% in TG group, p = 0.097). CONCLUSIONS: Oncologic and survival outcomes were similar in patients submitted to subtotal and total gastrectomy, suggesting that a subtotal gastrectomy with D2-lymphadenectomy for distal diffuse-type gastric carcinoma is not associated with a decrease in median overall survival and is an adequate surgical approach when technically feasible.

2.
Arch Gynecol Obstet ; 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39231831

RESUMO

PURPOSE: To investigate live birth rate (LBR) and cumulative live birth rate (CLBR) to achieve the first newborn per blastocyst transferred and oocyte retrieved in the first complete IVF cycle of autologous and donated oocytes and identify the possible success factors. METHODS: This was a retrospective cohort study of a private IVF center. There were 1867 cycles, 1241 of which were fresh transfers and 626, their subsequent thawing transfers. RESULTS: We found significant variables by binary logistic regression. For LBR, female infertility and the day of blastocyst transferred were relevant; however, for CLBR, the numbers of blastocysts available for future transfers, oocyte age, and maternal age were more critical. Oocyte age is a negative factor that begins to affect CLBR gradually beyond 36 years; from that age, there are significant worse results in polycystic ovary syndrome and poor responder patients. CONCLUSION: The LBR and CLBR were optimized for oocyte recipients when eight oocytes were retrieved (63.6%; 87.9%); at most, fourteen oocytes should be assigned to avoid freezing surplus blastocysts. Thirteen autologous oocytes (69.2%; 92.3%) were ideal for optimization. CLBR optimized after three blastocysts in donor oocytes (81.8%) and four for autologous oocyte patients (80.9%). Our outcomes are valuable for doctors and infertile couples, and they give us information on what we can expect from a first complete IVF cycle.

3.
Eur Spine J ; 31(10): 2723-2732, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35790650

RESUMO

PURPOSE: We show a systematic review of known complications during intraoperative neuromonitoring (IONM) using transcranial electric stimulation motor evoked potentials (TES-MEP) on cervical spine surgery, which provides a summary of the main findings. A rare complication during this procedure, cardiac arrest by cardioinhibitory reflex, is also described. METHODS: Findings of 523 scientific papers published from 1995 onwards were reviewed in the following databases: CENTRAL, Cochrane Library, Embase, Google Scholar, Ovid, LILACS, PubMed, and Web of Science. This study evaluated only complications on cervical spine surgery undergoing TES-MEP IONM. RESULTS: The review of the literature yielded 13 studies on the complications of TES-MEP IONM, from which three were excluded. Five studies are case series; the rest are case reports. Overall, 169 complications on 167 patients were reported in a total of 38,915 patients, a global prevalence of 0.43%. The most common complication was tongue-bite in 129 cases, (76.3% of all complication events). Tongue-bite had a prevalence of 0.33% (CI 95%, 0.28-0.39%) in all patients on TES-MEP IONM. A relatively low prevalence of severe complications was found: cardiac-arrhythmia, bradycardia and seizure, the prevalence of this complications represents only one case in all the sample. Alongside, we report the occurrence of cardiac arrest attributable to TES-MEP IONM. CONCLUSIONS: This systematic review shows that TES-MEP is a safe procedure with a very low prevalence of complications. To our best knowledge, asystole is reported for the first time as a complication during TES-MEP IONM.


Assuntos
Parada Cardíaca , Monitorização Neurofisiológica Intraoperatória , Vértebras Cervicais/cirurgia , Estimulação Elétrica , Potencial Evocado Motor/fisiologia , Parada Cardíaca/epidemiologia , Parada Cardíaca/etiologia , Humanos , Monitorização Neurofisiológica Intraoperatória/métodos , Monitorização Intraoperatória/métodos , Estudos Retrospectivos
4.
Sensors (Basel) ; 22(23)2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36501909

RESUMO

Within this paper, a PLC system that takes advantage of the loop resonance of an entire DC-PV string configured as a circular signal path is developed and implemented. Low cost and extremely simple transceivers intended to be installed within each PV module of a string have been designed and successfully tested. In addition, an anti-saturation coil has been conceived to avoid saturation of the core when the entire DC current of the string flows through it. Bi-directional half-duplex communication was successfully executed with up to a 1 MHz carrier frequency (150 kbps bitrate), using a simple ASK modulation scheme. The transmission and reception performance are presented, along with the overall system cost in comparison to the previous literature.


Assuntos
Comunicação , Desenho de Equipamento
5.
Rev Med Chil ; 150(11): 1422-1430, 2022 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-37358167

RESUMO

BACKGROUND: Transcatheter aortic-valve implantation (TAVI) was introduced in 2002 and the first implants in our country were performed in 2010. AIM: To review the TAVI experience in our hospital, considering the technology improvements and gained experience throughout this period. MATERIAL AND METHODS: All patients undergoing TAVI in our center were included. Results and complications were adjudicated according to the Valve Academic Research Consortium-2 (VARC-2) criteria. Patients were divided in 3 groups, according to procedural year: Period 1: 2010-2015 (n = 35); Period 2: 2016-2018 (n = 35); Period 3: 2019-2021 (n = 41). Mortality up to one year after the procedure was recorded. RESULTS: Between 2010 and 2021, 111 TAVI procedures were performed. The mean age of patients was 82 years and 47% were women. Risk scores for in-hospital mortality were STS 6.7%, EUROSCORE II 8.0% and ACC/STS TAVR Score 4.9%. The trans-femoral route was used in 88% and a balloon-expandable valve was chosen in 82% of patients. A successful implant was achieved in 96%, with an in-hospital mortality of 1.8%. Mortality at 30 days and 1-year were 2.7 and 9.0%, respectively. During period 3, 100% of implants were successful, with no in-hospital mortality, less vascular complications (p < 0.01), less stroke (p = 0.04), less severe paravalvular leak (p = 0.01) and significantly lower rate of acute complications (p < 0.01). CONCLUSIONS: TAVI achieves excellent results. With greater experience and better available technologies, these results are even more favorable.


Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Humanos , Feminino , Idoso de 80 Anos ou mais , Masculino , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodos , Estenose da Valva Aórtica/cirurgia , Próteses Valvulares Cardíacas/efeitos adversos , Resultado do Tratamento , Fatores de Risco
6.
J Neurosci Res ; 99(12): 3121-3147, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34716617

RESUMO

Astrocytes are abundant cells of the central nervous system (CNS) and are involved in processes including synapse formation/function, ion homeostasis, neurotransmitter uptake, and neurovascular coupling. Recent evidence indicates that astrocytes show diverse molecular, structural, and physiological properties within the CNS. This heterogeneity is reflected in differences in astrocyte structure, gene expression, functional properties, and responsiveness to injury/pathological conditions. Deeper investigation of astrocytic heterogeneity is needed to understand how astrocytes are configured to enable diverse roles in the CNS. While much has been learned about astrocytic heterogeneity in rodents, much less is known about astrocytic heterogeneity in the primate brain where astrocytes have greater size and complexity. The common marmoset (Callithrix jacchus) is a promising non-human primate model because of similarities between marmosets and humans with respect to genetics, brain anatomy, and cognition/behavior. Here, we investigated the molecular and structural heterogeneity of marmoset astrocytes using an array of astrocytic markers, multi-label confocal microscopy, and quantitative analysis. We used male and female marmosets and found that marmoset astrocytes show differences in expression of astrocytic markers in cortex, hippocampus, and cerebellum. These differences were accompanied by intra-regional variation in expression of markers for glutamate/GABA transporters, and potassium and water channels. Differences in astrocyte structure were also found, along with complex interactions with blood vessels, microglia, and neurons. This study contributes to our knowledge of the cellular and molecular features of marmoset astrocytes and is useful for understanding the complex properties of astrocytes in the primate CNS.


Assuntos
Astrócitos , Callithrix , Animais , Astrócitos/metabolismo , Encéfalo/metabolismo , Sistema Nervoso Central , Feminino , Masculino , Neurônios/metabolismo
7.
Catheter Cardiovasc Interv ; 97(6): E748-E757, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33058429

RESUMO

OBJECTIVES: To describe the characteristics of patients who undergo balloon pulmonary angioplasty (BPA) for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) and report the mid-term outcomes. BACKGROUND: BPA has been recently introduced in Latin America. Mid-term results have not been published. METHODS: Prospective Chilean Registry of inoperable CTEPH patients who underwent BPA. Clinical variables were analyzed at baseline, after each procedure and at follow-up. Hemodynamic variables were recorded before and after the last BPA. RESULTS: Between August 2016 and September 2019, 22 patients (17 women), 59 ± 12.7 years, underwent 81 BPA and were followed for as long as 33.1 months (mean 17.3 ± 7.5). Mean pulmonary artery pressure decreased by 17.4% (51.1 ± 12 vs. 42.2 ± 13 mmHg, p = .001), pulmonary vascular resistance by 23.9% (766.7 ± 351 vs. 583 ± 346 dynes/s/cm-5 , p = .001), cardiac index increased by 8% (2.3 ± 0.54 vs. 2.5 ± 0.54 L/min/m2 , p = .012), N-terminal pro-B-type natriuretic peptide decreased by 73.8% (1,685 ± 1,045 vs. 441.8 ± 276 pg/dl, p = .006), and 6-min walk distance improved by 135 m (316.7 ± 94 vs. 451.1 ± 113 m, p = .001). One patient (4.5%) developed lung reperfusion injury and four patients (18.2%) had minor bleeding (hemoptysis), after the procedure. There was no mortality associated with BPA. CONCLUSIONS: Our results confirm that BPA for inoperable CTEPH is a relatively safe procedure that improves clinical and hemodynamic parameters in the mid-term. This therapy should be considered as an alternative, mainly in places where access to PAH therapy or surgery is restricted.


Assuntos
Angioplastia com Balão , Hipertensão Pulmonar , Embolia Pulmonar , Angioplastia com Balão/efeitos adversos , Doença Crônica , Feminino , Seguimentos , Humanos , Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/etiologia , América Latina , Pulmão , Estudos Prospectivos , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/diagnóstico por imagem , Resultado do Tratamento
8.
J Org Chem ; 86(3): 2437-2446, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33369417

RESUMO

Six novel oxasqualenoids (polyether triterpenes) were isolated from the red alga Laurencia viridis. Laurokanols A-E (1-5) comprise an unreported tricyclic core with a [6,6]-spiroketal system. Yucatecone (6) shows a biogenetically intriguing epimerization at C14. Quantum mechanical calculations were used to corroborate their structures and to explain key steps involved in the biogenetic mechanisms proposed for the formation of oxasqualenoids.


Assuntos
Laurencia , Triterpenos , Estrutura Molecular
9.
Br J Neurosurg ; : 1-6, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34096815

RESUMO

OBJECTIVE: Patient safety indicators (PSI) are a set of potentially preventable events related to patient safety and opportunities for improvement. Eight pertinent PSI have been identified in patients with aneurysmal subarachnoid haemorrhage (ASAH), such as decubitus ulcer, and central line-related bacteraemia. Our aim was to evaluate the efficacy of a health care quality protocol to prevent the appearance of PSI in ASAH patients. METHODS: Adult patients treated for ASAH were included in a retrospective control group of 35 patients and a prospective experimental group of 35 patients when the prevention program was implemented. We evaluated the occurrence of PSI, and its relation to age, sex, Hunt and Hess scale grade, type of aneurysm treatment, length of hospital stay, and Glasgow Outcome Scale scores. RESULTS: Both groups had similar characteristics except for a longer hospital stay in the control group. The overall PSI prevalence decreased significantly in the experimental group compared to the control group. The experimental group had a decreased risk for having at least one PSI: OR = 0.21 (0.08-0.57, CI 95%). The absolute risk reduction is 37.1% (58.9%-15.4%), the preventable fraction for the population is 28.3% (10.6%-40.0%), and the number needed to treat is 2.69. CONCLUSIONS: The health care quality protocol is effective to prevent ISP in ASAH patients. Implementing this prevention program has no effect on the neurological state of the patient at the hospital discharge. Still, it is successful in decreasing the PSI prevalence and the days of hospital stay.

10.
Bioorg Chem ; 92: 103276, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31539745

RESUMO

Chagas disease and leishmaniasis are tropical neglected diseases caused by kinetoplastids protozoan parasites of Trypanosoma and Leishmania genera, and a public health burden with high morbidity and mortality rates in developing countries. Among difficulties with their epidemiological control, a major problem is their limited and toxic treatments to attend the affected populations; therefore, new therapies are needed in order to find new active molecules. In this work, sixteen Laurencia oxasqualenoid metabolites, natural compounds 1-11 and semisynthetic derivatives 12-16, were tested against Leishmania amazonensis, Leishmania donovani and Trypanosoma cruzi. The results obtained point out that eight substances possess potent activities, with IC50 values in the range of 5.40-46.45 µM. The antikinetoplastid action mode of the main metabolite dehydrothyrsiferol (1) was developed, also supported by AFM images. The semi-synthetic active compound 28-iodosaiyacenol B (15) showed an IC50 5.40 µM against Leishmania amazonensis, turned to be non-toxic against the murine macrophage cell line J774A.1 (CC50 > 100). These values are comparable with the reference compound miltefosine IC50 6.48 ±â€¯0.24 and CC50 72.19 ±â€¯3.06 µM, suggesting that this substance could be scaffold for development of new antikinetoplastid drugs.


Assuntos
Antiprotozoários/farmacologia , Éteres/farmacologia , Leishmania/efeitos dos fármacos , Triterpenos/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Éteres/síntese química , Éteres/química , Camundongos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-Atividade , Triterpenos/síntese química , Triterpenos/química
11.
Mar Drugs ; 17(7)2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31331002

RESUMO

Acanthamoeba genus is a widely distributed and opportunistic parasite with increasing importance worldwide as an emerging pathogen in the past decades. This protozoan has an active trophozoite stage, a cyst stage, and is dormant and very resistant. It can cause Acanthamoeba keratitis, an ocular sight-threatening disease, and granulomatous amoebic encephalitis, a chronic, very fatal brain pathology. In this study, the amoebicidal activity of sixteen Laurencia oxasqualenoid metabolites and semisynthetic derivatives were tested against Acanthamoeba castellanii Neff. The results obtained point out that iubol (3) and dehydrothyrsiferol (1) possess potent activities, with IC50 values of 5.30 and 12.83 µM, respectively. The hydroxylated congeners thyrsiferol (2) and 22-hydroxydehydrothyrsiferol (4), active in the same value range at IC50 13.97 and 17.00 µM, are not toxic against murine macrophages; thus, they are solid candidates for the development of new amoebicidal therapies.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Laurencia/química , Extratos Vegetais/farmacologia , Esqualeno/farmacologia , Amebicidas/isolamento & purificação , Animais , Linhagem Celular , Furanos/isolamento & purificação , Furanos/farmacologia , Concentração Inibidora 50 , Macrófagos , Camundongos , Extratos Vegetais/isolamento & purificação , Piranos/isolamento & purificação , Piranos/farmacologia , Esqualeno/análogos & derivados , Esqualeno/isolamento & purificação , Testes de Toxicidade , Trofozoítos/efeitos dos fármacos
12.
Molecules ; 24(3)2019 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-30717439

RESUMO

A new cytotoxic cyclononapeptide, sclerin, cyclo(⁻Dab¹â»Ser²â»Tyr³â»Gly4⁻Thr5⁻Val6⁻Ala7⁻ Ile8⁻Pro8⁻) (1), was isolated from the methanol extract of the seeds of Annona scleroderma, together with the known metabolite, cyclosenegalin A, cyclo(⁻Pro¹â»Gly²â»Leu³â»Ser4⁻Ala5⁻Val6⁻Thr7⁻) (2). The planar structures for the two compounds were established by comprehensive analysis of NMR and ESI-HRMS data, and the absolute stereochemistry was stablished by Marfey's method. Compound 1 showed moderate cytotoxic activity against the human prostate carcinoma cell line DU-145 at µM concentration.


Assuntos
Annona/química , Cumarínicos/farmacologia , Peptídeos Cíclicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/química , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Peptídeos Cíclicos/química
14.
Mar Drugs ; 16(4)2018 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-29673138

RESUMO

The red seaweed Laurencia viridis is a rich source of oxygenated secondary metabolites that were derived from squalene. We report here the structures of three novel compounds, (+)-longilene peroxide (1), longilene (2), and (+)-prelongilene (3) that were isolated from this alga, in addition to other substances, 4 and 5, resulting from their acid-mediated degradation. The effect of compounds 1 and 3 against Ser-Thr protein phosphatase type 2A (PP2A) was evaluated, showing that (+)-longilene peroxide (1) inhibited PP2A (IC50 11.3 μM). In order to explain the interaction between PP2A and compounds 1 and 3, molecular docking simulations onto the PP2A enzyme-binding region were used.


Assuntos
Organismos Aquáticos/química , Produtos Biológicos/química , Inibidores Enzimáticos/química , Laurencia/química , Proteína Fosfatase 2/antagonistas & inibidores , Alga Marinha/química , Produtos Biológicos/farmacologia , Inibidores Enzimáticos/farmacologia , Simulação de Acoplamento Molecular , Ligação Proteica , Esqualeno/química , Relação Estrutura-Atividade
15.
Proc Natl Acad Sci U S A ; 111(37): 13301-6, 2014 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-25197076

RESUMO

The production of purposely made painted or engraved designs on cave walls--a means of recording and transmitting symbolic codes in a durable manner--is recognized as a major cognitive step in human evolution. Considered exclusive to modern humans, this behavior has been used to argue in favor of significant cognitive differences between our direct ancestors and contemporary archaic hominins, including the Neanderthals. Here we present the first known example of an abstract pattern engraved by Neanderthals, from Gorham's Cave in Gibraltar. It consists of a deeply impressed cross-hatching carved into the bedrock of the cave that has remained covered by an undisturbed archaeological level containing Mousterian artifacts made by Neanderthals and is older than 39 cal kyr BP. Geochemical analysis of the epigenetic coating over the engravings and experimental replication show that the engraving was made before accumulation of the archaeological layers, and that most of the lines composing the design were made by repeatedly and carefully passing a pointed lithic tool into the grooves, excluding the possibility of an unintentional or utilitarian origin (e.g., food or fur processing). This discovery demonstrates the capacity of the Neanderthals for abstract thought and expression through the use of geometric forms.


Assuntos
Gravuras e Gravação , Sedimentos Geológicos , Homem de Neandertal , Animais , Cavernas , Gibraltar , Humanos , Imageamento Tridimensional , Tempo (Meteorologia)
16.
J Nat Prod ; 78(4): 712-21, 2015 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-25781558

RESUMO

The chemical study of the red alga Laurencia viridis has led to the isolation of four new polyether triterpenoids: 28-hydroxysaiyacenol B (2), saiyacenol C (3), 15,16-epoxythyrsiferol A (4), and 15,16-epoxythyrsiferol B (5). The structures of 2 and 3 were established mainly by NMR data analysis and comparison with the well-known metabolite dehydrothyrsiferol (1). However, due to the existence of a nonprotonated carbon within the epoxide functionality, stereochemical assignments in 4 and 5 required an in-depth structural study that included NOESY data, J-based configuration analysis, comparison with synthetic models, and DFT calculations. The biological activities of the new metabolites and other related oxasqualenoids were evaluated for the first time against a panel of relevant biofouling marine organisms, and structure-activity conclusions were obtained.


Assuntos
Incrustação Biológica/prevenção & controle , Laurencia/química , Triterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Piranos/química , Piranos/isolamento & purificação , Espanha , Relação Estrutura-Atividade , Triterpenos/química , Triterpenos/farmacologia
17.
Mar Drugs ; 12(10): 5188-96, 2014 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-25317536

RESUMO

Three new norzoanthamine-type alkaloids, named 2-hydroxy-11-ketonorzoan thamide B (1), norzoanthamide B (2) and 15-hydroxynorzoanthamine (3), were isolated from Zoanthus sp. specimens collected at the Canary Islands. Their structures were determined by interpretation of NMR and HR-ESIMS data. Relative configurations of their chiral centers were proposed on the basis of ROESY spectra and by comparison of their spectroscopic data with those of the well-known compound, norzoanthamine.


Assuntos
Alcaloides/química , Antozoários/química , Azepinas/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Quinolinas/química , Animais , Oxirredução , Espanha
18.
Org Lett ; 26(31): 6529-6534, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-38888989

RESUMO

A key to understanding the properties of functional molecules is to determine their conformation in solution. A conformational analysis procedure that relies on quantum mechanical calculations and the widely used DP4+ probability was evaluated to decipher the structural information encoded in NMR chemical shifts. The results underscore the potential utility of using NMR chemical shifts in advancing conformational analysis studies of complex molecules in solution.

19.
Brain Spine ; 4: 102824, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38706799

RESUMO

Introduction: Hydrocephalus, altering cerebrospinal fluid (CSF) dynamics, affects 175 per 100,000 adults worldwide. Ventriculoperitoneal shunts (VPS) manage symptomatic hydrocephalus, with 125,000 cases annually. Despite efficacy, VPS face complications, necessitating interventions. Research question: "What are the mechanisms and risk factors for bilateral VIth and VIIth lower motor neuron palsies in hydrocephalus patients with a fourth ventriculoperitoneal shunt?" Material and methods: This study details a 36-year-old female with a neonatal meningitis history, multiple shunt replacements, admitted for abdominal pain secondary to pelvic inflammatory disease. An abdominal shunt catheter removal and external ventricular drain placement occurred after consultation with a general surgeon. A cardiac atrial approach and subsequent laparoscopic abdominal approach were performed without complications. Results: After one month, the patient showed neurological complications, including decreased facial expression, gait instability, and bilateral VIth and VIIth lower motor neuron palsies, specifically upgazed and convergence restriction. Discussion: The complication's pathophysiology is discussed, attributing it to potential brainstem herniation from over-drainage of CSF. Literature suggests flexible endoscopic treatments like aqueductoplasty/transaqueductal approaches into the fourth ventricle. Conclusions: This study underscores the need for increased awareness in monitoring neurological outcomes after the fourth ventriculoperitoneal shunt, particularly in cases with laparoscopic-assisted abdominal catheter placement. The rarity of bilateral abducens and facial nerve palsies emphasizes the importance of ongoing research to understand pathophysiology and develop preventive and therapeutic strategies for this unique complication.

20.
Chemistry ; 19(26): 8525-32, 2013 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-23649973

RESUMO

The structural determination of small organic molecules is mainly undertaken by using NMR techniques, although it is increasingly supplemented by using computational methods. NMR parameters, such as chemical shifts and coupling constants, are extremely sensitive indicators of local molecular conformation and are a source of structural evidence. However, their interpretation is fairly challenging in many circumstances, such as the case of the new polyether squalene derivative nivariol, the structure of which was elucidated by means of NMR spectroscopy and DFT calculations. The potential flexibility of this molecule and the high number of quaternary carbon atoms that it contains make its configurational assignment very difficult. Moreover, the relative configuration of four separated stereoclusters was established and subsequently connected by using NOE and J-based analysis, as well as by a comparison of its experimental (13)C NMR chemical shifts with the corresponding population-weighted values, as calculated by using DFT methods. Limitations of these used approaches became apparent but were overcome by combining the two methods.


Assuntos
Produtos Biológicos/química , Éteres Cíclicos/química , Éteres/química , Furanos/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estereoisomerismo
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