Grief and Bereavement in the Latino/a Community: A Literature Synthesis and Directions for Future Research.

Introduction: Bereavement and grief are social phenomena influenced by a multitude of cultural factors. Prior studies of bereavement adjustment have primarily focused on bereaved survivors who identify racially as white; knowledge of the experience of grief and bereavement among racial/ethnic and other minority groups, particularly among Latino/a groups, in the United States is limited. Objective: The purpose of this review is to synthesize the literature documenting the bereavement experiences of the Latino/a community, evaluate the strength of the current evidence, and provide recommendations to guide future research. Method: A narrative review of research on grief and bereavement in the Latino/a community published between 1990 and 2021. Two authors used a thematic, deductive approach to categorize emergent prevalent themes from the literature and used The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) and The Oxford Center for Evidence-Based Medicine-Evidence Quality Rating Scale (OCEBM) approaches to evaluate the strength of the qualitative and quantitative reports reviewed. Results: Searches revealed 26 reports that were categorized into six themes: cultural values, mourning rituals, immigration, spirituality, disparities related to the COVID-19 pandemic, and the effects of COVID-19 on Latino/a communities. Our evaluation concludes that the evidence in this area is weak, with limited methodologically rigorous research examining the influence of culture on bereavement among Latino/a groups. Conclusion: Research is needed to identify Latino/a groups' mental health, cultural, social, and family needs and how fulfillment of mourning rituals and other cultural factors may promote or impede bereavement adjustment. Investigation into factors that may protect bereaved survivors against adverse mental health outcomes is also needed. A better understanding of Latino/a grief and bereavement is a step toward the development of culturally competent interventions designed to promote the mental health and psychosocial adjustment of Latino/a mourners.

Cost-effectiveness of new oral anticoagulants and warfarin in atrial fibrillation from adverse events perspective / Análisis de costo-efectividad de los nuevos anticoagulantes orales y la warfarina en fibrilación auricular desde la perspectiva de los eventos adversos

Abstract Objective: new oral anticoagulants (apixaban, dabigatran and rivaroxaban) are the newest advance for stroke's risk reduction in atrial fibrillation. These are as effective as warfarin in preventing stroke/systemic embolism, but exists heterogenic outcomes as gastrointestinal hemorrhage, mortality reduction, minor and major haemorrhage (adverse events). Despite of this, there is a lack of cost-effectiveness models focused on adverse events. Methods: a cost-effectiveness analysis with a third payer perspective, interventions included were apixaban, dabigatran, warfarin and rivaroxaban. Discount rate of 3%, and 10 years of temporal horizon. The Markov model is an international, validated, and modified to assess better adverse events. Major assumptions, patients with mild and moderate stroke returns to oral anticoagulation, patients with moderate and severe hemorrhage do not returns to oral anticoagulation. Probabilities and QALYs, taken from a cost-effectiveness analysis published. Costs, information from a cohort of stroke patients. Software, TreeAge pro( and Excel(. Results: overall results, 1.48 QALYs, $17 916 USD for apixaban, 1.49 QALYs, $18 122 USD for dabigatran, 1.32 QALYs, $21 966 USD for warfarin and 1.24 QALYs, $24 547 USD for rivaroxaban. The ICER for apixaban compared to dabigatran was $12 988 USD. Negative ICER for warfarin and rivaroxaban, shows that are dominated alternatives (less benefits and more costs). Apixaban is cost-effective at 70% and dabigatran at 30% of iterations in the probabilistic sensitivity analysis. Conclusions: apixaban and dabigatran are cost-effective alternatives, apixaban is the most cost-effective alternative from adverse events perspective. Warfarin shows better results than rivaroxaban to prevent stroke in atrial fibrillation from adverse events perspective.

Resumen Introducción: los nuevos anticoagulantes orales (apixabán, dabigatrán y rivaroxabán) son el avance más reciente para la reducción del riesgo de accidente cerebrovascular en la fibrilación auricular. Estos son tan efectivos como la warfarina en la prevención del accidente cerebrovascular/embolia sistémica, pero existen resultados heterogéneos como hemorragia gastrointestinal, reducción de la mortalidad y hemorragia menor y mayor (eventos adversos). Pese a ello, se carece de modelos de costo-efectividad enfocados en eventos adversos. Materiales y métodos: se hizo un análisis de costo-efectividad con una perspectiva de tercer pagador, en el que se incluyeron intervenciones como apixabán, dabigatrán, warfarina y rivaroxabán. La tasa de descuento fue del 3% y 10 años de horizonte temporal. El modelo de Markov es internacional, validado y modificado para evaluar mejor eventos adversos. Las principales suposiciones, los pacientes con accidente cerebrovascular leve y moderado vuelven a la anticoagulación oral, los pacientes con hemorragia moderada y grave no regresan a la anticoagulación oral. Probabilidades y AVAC, tomados de un análisis de costo-efectividad publicado. Los costos, información de una cohorte de pacientes con accidente cerebrovascular. Software, TreeAge pro y Excel. Resultados: resultados generales, 1.48 QALYs, $ 17 916 USD para apixabán, 1.49 QALYs, $ 18 122USD para dabigatrán, 1.32 QALYs, $ 21 966 USD para warfarina y 1.24 QALYs, $ 24 547 USD para rivaroxabán. El ICER para apixabán en comparación con dabigatrán fue de $ 12 988 USD. El ICER negativo para warfarina y rivaroxabán muestra que son alternativas dominadas (menos beneficios y más costos). Apixabán es rentable en 70% y dabigatrán en 30% de las iteraciones en el análisis de sensibilidad probabilístico. Conclusión: apixabán y dabigatrán son costo-efectivos; apixabán es la alternativa más costo-efectiva desde la perspectiva de los eventos adversos. Warfarina mostró mejores resultados que rivaroxabán para prevenir accidentes cerebrovasculares en fibrilación auricular desde la perspectiva de los eventos adversos.

The Hsp60 protein of helicobacter pylori displays chaperone activity under acidic conditions.

The heat shock protein, Hsp60, is one of the most abundant proteins in Helicobacter pylori. Given its sequence homology to the Escherichia coli Hsp60 or GroEL, Hsp60 from H. pylori would be expected to function as a molecular chaperone in this organism. H. pylori is an organism that grows on the gastric epithelium, where the pH can fluctuate between neutral and 4.5 and the intracellular pH can be as low as 5.0. This study was performed to test the ability of Hsp60 from H. pylori to function as a molecular chaperone under mildly acidic conditions. We report here that Hsp60 could suppress the acid-induced aggregation of alcohol dehydrogenase (ADH) in the 7.0-5.0 pH range. Hsp60 was found to undergo a conformational change within this pH range. It was also found that exposure of hydrophobic surfaces of Hsp60 is significant and that their exposure is increased under acidic conditions. Although, alcohol dehydrogenase does not contain exposed hydrophobic surfaces, we found that their exposure is triggered at low pH. Our results demonstrate that Hsp60 from H. pylori can function as a molecular chaperone under acidic conditions and that the interaction between Hsp60 and other proteins may be mediated by hydrophobic interactions.

GTP binds to α-crystallin and causes a significant conformational change.

ATP was previously reported to bind to the chaperone α-crystallin resulting in a significant effect on the protein's ability to suppress the aggregation of a thermally denatured protein. Here, we have investigated the binding of GTP to α-crystallin. Unlike ATP, binding of GTP to α-crystallin did not affect its ability to suppress the aggregation of thermally denatured rhodanese. GTP binding induced a conformational change on α-crystallin, however the degree of exposed hydrophobic surfaces, which are believed to be involved in the binding of the chaperone to denaturing proteins did not change. Here, we report that GTP binds to α-crystallin and this results in a decreased stability of the chaperone as indicated by urea denaturation.

Interaction of oxidized chaperonin GroEL with an unfolded protein at low temperatures.

The chaperonin GroEL binds to non-native substrate proteins via hydrophobic interactions, preventing their aggregation, which is minimized at low temperatures. In the present study, we investigated the refolding of urea-denatured rhodanese at low temperatures, in the presence of ox-GroEL (oxidized GroEL), which contains increased exposed hydrophobic surfaces and retains its ability to hydrolyse ATP. We found that ox-GroEL could efficiently bind the urea-unfolded rhodanese at 4°C, without requiring excess amount of chaperonin relative to normal GroEL (i.e. non-oxidized). The release/reactivation of rhodanese from GroEL was minimal at 4°C, but was found to be optimal between 22 and 37°C. It was found that the loss of the ATPase activity of ox-GroEL at 4°C prevented the release of rhodanese from the GroEL-rhodanese complex. Thus ox-GroEL has the potential to efficiently trap recombinant or non-native proteins at 4°C and release them at higher temperatures under appropriate conditions.

Divalent cations stabilize GroEL under conditions of oxidative stress.

The divalent cations Mg(2+), Mn(2+), Zn(2+), Ca(2+), and Ni(2+) were found to protect against proteolysis a form of GroEL (ox-GroEL) prepared by exposing GroEL for 16h to 6mM hydrogen peroxide (H(2)O(2)). K(+) and other monovalent cations did not have any effect. Divalent cations also induced a conformational change of ox-GroEL that led to the decrease of its large exposed hydrophobic surfaces (exposed with H(2)O(2)). Ox-GroEL incubated with a divalent cation behaved like N-GroEL in that it could transiently interact with H(2)O(2)-inactivated rhodanese (ox-rhodanese), whereas ox-GroEL alone could strongly interact with ox-rhodanese. Although, ox-GroEL incubated with a divalent cation could not recover the ATPase activity (66%) lost with H(2)O(2), it could facilitate the reactivation of ox-rhodanese (>86% of active rhodanese recovered), without requiring ATP or the co-chaperonin, GroES. This is the first report to demonstrate a role for the divalent cations on the structure and function of ox-GroEL.

Wettability and bonding of self-etching dental adhesives. Influence of the smear layer.

OBJECTIVES: To evaluate dentin wettability and bonding of self-etching and total-etch adhesives on smear layer-covered and smear layer-free dentin. METHODS: Three self-etching adhesives (Clearfil SE Bond, AdheSE and Xeno III) and one total-etch adhesive (SingleBond) were evaluated. The substrates were mid coronal smear layer-covered and smear layer-free dentin. Dentin wettability by resins was studied from contact angle measurement using sessile drop method and Axisymmetric Drop Shape Analysis (ADSA). Shear-bond strength was evaluated using a push-out technique (ad hoc design). Data were analysed with two-way ANOVA and Tukey's test. RESULTS: Similar values of dentin wettability were obtained for all adhesives tested regardless the presence of smear layer. Even though, Xeno III and AdheSE exhibited slightly lower wettability (higher contact angles values) on smear layer-free dentin. Likewise, the presence of smear layer did not affect the shear-bond strength. Total-etch adhesive obtained higher shear-bond strength than self-etching adhesives, which obtained similar values. SIGNIFICANCE: Wettability is similar between self-etching and total-etch adhesives. The smear layer affects slightly the wettability of self-etching adhesives. Shear-bond strength is not sensitive to the smear layer presence. Total-etch adhesion is stronger than self-etching adhesion. There is no clear relationship between wettability and bond strength.

Effect of acid etching on dentin wettability and roughness: self-etching primers versus phosphoric acid.

OBJECTIVE: To compare the effect of self-etching primers and phosphoric acid on the wettability and roughness of smear layer-covered and smear layer-free dentin. MATERIALS AND METHOD: Three self-etching primers (Clearfil SE Bond, AdheSE, and Xeno III) and 10% (w/w) phosphoric acid (H(3)PO(4)) solution were evaluated. The substrates were midcoronal dentin with and without smear layer. For each liquid, pH, density, and surface tension were determined. Water wettability of dentin and roughness were measured before and after each etching. Wettability of self-etching primers and phosphoric acid was measured on untreated dentin. RESULTS: Water wettability increased after acid conditioning similarly for all the liquids used. On smear layer-covered surfaces, self-etching primers achieved a comparable wetting but with greater contact angles than phosphoric acid. However, on smear layer-free surfaces, the increasing sequence of contact angle was Clearfil SE < AdheSE < Xeno III < Phosphoric acid. The treatment with phosphoric acid (lowest pH) produced the highest roughness increase on both dentin substrates. The roughening effect of the self-etching adhesives was more evident for AdheSE and Xeno III. CONCLUSIONS: Self-etching primers and phosphoric acid promote similar water wettability increase. However, self-etching primers provided lower dentin roughness increase than pretreatment with phosphoric acid. The presence of smear layer did not affect the results of self-etching and phosphoric acid treatments.

Comparison of regional bond strength in root thirds among fiber-reinforced posts luted with different cements.

AIM: To compare regional bond strength in different thirds of the root canal, among glass fiber-reinforced (FRC) endodontic posts luted with different cements, using the push-out test. MATERIAL AND METHODS: Sixty extracted human anterior teeth were endodontically treated with gutta-percha and AH Plus sealer. The crown portion was removed, and a dowel space was prepared. Prepared teeth were randomly assigned to one of six groups (n = 10) for luting glass FRC Postec posts, with one of the six cement systems (Ketac Cem Aplicap, Relyx Unicem Aplicap, Variolink II/Excite DCS, Panavia F/ED Primer, C&B cement/All-Bond 2, and Multilink/Multilink Primer A/B), using an alignment technique. Specimens were embedded in resin, and each root was sectioned into six 1-mm thick serial slices. A push-out test was performed to measure regional bond strengths and to identify the type of failure. RESULTS: The highest bond strength values were found in the cervical third and the lowest in the apical third. Highest values were obtained using Variolink II, Panavia F, and Multilink resin cements followed by C&B resin cement and Relyx Unicem ionomer resin cement; Ketac-cem ionomer cement showed the lowest value. CONCLUSION: Highest bond strength values were obtained in the cervical third and with resin cements.

Esofagocardiomiotomía de heller con fundoplicatura anterior de dor por laparoscopia en el tratamiento de la alcalasia / Heller Esophagocardyomiotomy with dor anterior fundoplication by laparoscopy in the treatment of achalasia

Presentar la experiencia obtenida por los autores practicando la esofagocardiomiotomía de Heller con fundoplicatura anterior de Dor por laparoscopia en el tratamiento de los pacientes con diagnóstico de acalasia, en el Centro Policlínico Valencia. Es un estudio retrospectivo realizado en el Centro Policlínico La Villa, Valencia, hospital privado donde se revisaron las historias clínicas de 12 pacientes que acudieron a la consulta quirúrgica con diagnóstico de acalasia entre noviembre del año 1996 y diciembre del 2005, a quienes se les practicó esofagocardiomiotomía de Heller con fundoplicatura anterior de Dor por laparoscopia. Los pacientes a quienes se les practicó la esofagocardiomiotomía de Heller con fundoplicatura anterior de Dor por laparoscopia presentaban disfagia como síntoma principal, dilataciones previas en el 100 por ciento de los casos, manometría que reportaba aperistalsis en el 100 por ciento y un promedio de presión en el Esfínter Esofágico Interior de 48.8 mmHg. El tiempo quirúrgico osciló entre 65 y 150 minutos, tolerancia a la vía oral en las primeras 24 horas, estancia hospitalaria promedio de 31.6 horas y sólo un paciente presentó una micro-perforación esofágica que evolucionó satisfactoriamente con tratamiento conservador. Hubo contacto telefónico con siete pacientes y no refirieron síntomas. Las complicaciones intra y post-operatorias de muestran lo seguro del procedimiento, aunado a los resultados satisfactorios hacen de la esofagocardiomiotomía de Heller con fundoplicatura de Dor por laparoscopia el procedimiento de elección en la Acalasia.

Protection of GroEL by its methionine residues against oxidation by hydrogen peroxide.

GroEL undergoes an important functional and structural transition when oxidized with hydrogen peroxide (H2O2) concentrations between 15 and 20mM. When GroEL was incubated for 3h with 15 mM H2O2, it retained its quaternary structure, chaperone and ATPase activities. Under these conditions, GroEL's cysteine and tyrosine residues remained intact. However, all the methionine residues of the molecular chaperone were oxidized to the corresponding methionine-sulfoxides under these conditions. The oxidation of the methionine residues was verified by the inability of cyanogen bromide to cleave at the carboxyl side of the modified methionine residues. The role for the proportionately large number (23) of methionine residues in GroEL has not been identified. Methionine residues have been reported to have an antioxidant activity in proteins against a variety of oxidants produced in biological systems including H2O2. The carboxyl-terminal domain of GroEL is rich in methionine residues and we hypothesized that these residues are involved in the protection of GroEL's functional structure by scavenging H2O2. When GroEL was further incubated for the same time, but with increasing concentrations of H2O2 (>15 mM), the oxidation of GroEL's cysteine residues and a significant decrease of the tyrosine fluorescence due to the formation of dityrosines were observed. Also, at these higher concentrations of H2O2, the inability of GroEL to hydrolyze ATP and to assist the refolding of urea-unfolded rhodanese was observed.

On the chaperonin activity of GroEL at heat-shock temperature.

The studies of GroEL, almost exclusively, have been concerned with the function of the chaperonin under non-stress conditions, and little is known about the role of GroEL during heat shock. Being a heat shock protein, GroEL deserves to be studied under heat shock temperature. As a model for heat shock in vitro, we have investigated the interaction of GroEL with the enzyme rhodanese undergoing thermal unfolding at 43 degrees C. GroEL interacted strongly with the unfolding enzyme forming a binary complex. Active rhodanese (82%) could be recovered by releasing the enzyme from GroEL after the addition of several components, e.g. ATP and the co-chaperonin GroES. After evaluating the stability of the GroEL-rhodanese complex, as a function of the percentage of active rhodanese that could be released from GroEL with time, we found that the complex had a half-life of only one and half-hours at 43 degrees C; while, it remained stable at 25 degrees C for more than 2 weeks. Interestingly, the GroEL-rhodanese complex remained intact and only 13% of its ATPase activity was lost during its incubation at 43 degrees C. Further, rhodanese underwent a conformational change over time while it was bound to GroEL at 43 degrees C. Overall, our results indicated that the inability to recover active enzyme at 43 degrees C from the GroEL-rhodanese complex was not due to the disruption of the complex or aggregation of rhodanese, but rather to the partial loss of its ATPase activity and/or to the inability of rhodanese to be released from GroEL due to a conformational change.

Oxidized GroEL can function as a chaperonin.

Here, we report on the facilitated reactivation (85%) of oxidatively inactivated rhodanese by an oxidized form of the molecular chaperone GroEL (ox-GroEL). Reactivation by ox-GroEL required a reductant, and the enzyme substrate, sodium thiosulfate. Also, we found that ox-GroEL formed a complex with oxidatively inactivated rhodanese as shown by differential centrifugation and fluorescence spectroscopy. Ox-GroEL was obtained upon incubation of native GroEL for 16 h with 5 mM hydrogen peroxide. Under these conditions, GroEL was shown to retain its quaternary and secondary structures, but it displayed an increased exposure of hydrophobic surfaces as detected with 1,1'-bis(4-anilino) naphthalene-5,5'-disulfonic acid (bisANS) fluorescence. Additionally, ox-GroEL was significantly more sensitive towards proteolysis with trypsin compared to the native form of the protein. The oxidatively inactivated form of rhodanese, also had an increased exposure of hydrophobic surfaces, as previously reported. Thus, the proteins binding appeared to be mediated by hydrophobic interactions. Unlike in prior reactivation studies that involved native GroEL or alpha-crystallin, we have clearly shown that an oxidized form of GroEL can function as a molecular chaperone in the reactivation of oxidatively inactivated rhodanese suggesting that GroEL retains the ability to protect proteins during oxidative stress.

Hydrogen peroxide induces the dissociation of GroEL into monomers that can facilitate the reactivation of oxidatively inactivated rhodanese.

Although, several studies have been reported on the effects of oxidants on the structure and function of other molecular chaperones, no reports have been made so far for the chaperonin GroEL. The ability of GroEL to function under oxidative stress was investigated in this report by monitoring the effects of hydrogen peroxide (H(2)O(2)) on the structure and refolding activity of this protein. Using fluorescence spectroscopy and light scattering, we observed that GroEL showed increases in exposed hydrophobic sites and changes in tertiary and quaternary structure. Differential sedimentation, gel electrophoresis, and circular dichroism showed that H(2)O(2) treated GroEL underwent irreversible dissociation into monomers with partial loss of secondary structure. Relative to other proteins, GroEL was found to be highly resistant to oxidative damage. Interestingly, GroEL monomers produced under these conditions can facilitate the reactivation of H(2)O(2)-inactivated rhodanese but not urea-denatured rhodanese. Recovery of approximately 84% active rhodanese was obtained with either native or oxidized GroEL in the absence of GroES or ATP. In comparison, urea-denatured GroEL, BSA and the refolding mixture in the absence of proteins resulted in the recovery of 72, 50, and 49% rhodanese activity, respectively. Previous studies have shown that GroEL monomers can reactivate rhodanese. Here, we show that oxidized monomeric GroEL can reactivate oxidized rhodanese suggesting that GroEL retains the ability to protect proteins during oxidative stress.

The ATPase activity of GroEL is supported at high temperatures by divalent cations that stabilize its structure.

Previously, we reported that the ATPase activity of GroEL that requires potassium and magnesium was highly temperature dependent in the 25-60 degrees C range. Here, we report that the monovalent cations, rubidium and ammonium were able to fully substitute for potassium; while the divalent cations manganese, cobalt, and nickel supported the ATPase activity of GroEL albeit to a lesser degree than magnesium. ATPase activities with manganese, cobalt, and nickel were 64%, 41%, and 29%, respectively, of the maximum activity (100%) when utilizing magnesium. Interestingly, the ability of all the cations to support the GroEL ATPase activity was somewhat consistent over the entire 25-60 degrees C range. Maximum ATPase activities were observed at 49 degrees C. Here, the influence of these cations on the thermal denaturation of GroEL was also monitored using bisANS binding as an indication of the exposure of hydrophobic surfaces during thermal denaturation of GroEL. Maximum exposure of hydrophobic surfaces on GroEL alone or in the presence of each of the monovalent cations was determined to occur at 65 degrees C. However, the maximum exposure of hydrophobic surfaces on GroEL in the presence of magnesium, manganese, cobalt or nickel was found to occur at 71 degrees C indicating that GroEL is significantly stabilized against thermal denaturation by these divalent cations.

GroEL interacts transiently with oxidatively inactivated rhodanese facilitating its reactivation.

When the enzyme rhodanese was inactivated with hydrogen peroxide (H(2)O(2)), it underwent significant conformational changes, leading to an increased exposure of hydrophobic surfaces. Thus, this protein seemed to be an ideal substrate for GroEL, since GroEL uses hydrophobic interactions to bind to its substrate polypeptides. Here, we report on the facilitated reactivation (86%) of H(2)O(2)-inactivated rhodanese by GroEL alone. Reactivation by GroEL required a reductant and the enzyme substrate, but not GroES or ATP. Further, we found that GroEL interacted weakly and/or transiently with H(2)O(2)-inactivated rhodanese. A strong interaction with rhodanese was obtained when the enzyme was pre-incubated with urea, indicating that exposure of hydrophobic surfaces alone on oxidized rhodanese was not sufficient for the formation of a strong complex and that a more unfolded structure of rhodanese was required to interact strongly with GroEL. Unlike prior studies that involved denaturation of rhodanese through chemical or thermal means, we have clearly shown that GroEL can function as a molecular chaperone in the reactivation of an oxidatively inactivated protein. Additionally, the mechanism for the GroEL-facilitated reactivation of rhodanese shown here appears to be different than that for the chaperonin-assisted folding of chemically unfolded polypeptides in which a nucleotide and sometimes GroES is required.