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1.
Artigo em Inglês | MEDLINE | ID: mdl-38833135

RESUMO

PURPOSE OF REVIEW: Management of meniscal injuries in the elite athlete is a difficult problem secondary to the high demands of athletic competition, the need for a timely return to sport, and the desire to maximize performance over time. The purpose of this review is to provide an up-to-date summary on the current literature and trends regarding the management of meniscus injuries with a special consideration for elite athletes. RECENT FINDINGS: Historically, partial meniscectomy has been the primary treatment option for meniscus injuries. However, in recent years there has been an increased emphasis on meniscus preservation due to the increased risk of cartilage degeneration over time. Moreover, while partial meniscectomy still provides a quicker return to sport (RTS), recent literature has demonstrated similar rates of RTS and return to pre-injury levels between partial meniscectomy and meniscus repair. In the setting of symptomatic meniscal deficiency, meniscus allograft transplantation has become an increasingly utilized salvage procedure with promising yet variable outcomes on the ability to withstand elite competition. Currently, there is no uniform approach to treating meniscal injuries in elite athletes. Therefore, an individualized approach is required with consideration of the meniscus tear type, location, concomitant injuries, athlete expectations, rehabilitation timeline, and desire to prevent or delay knee osteoarthritis. In athletes with anatomically repairable tears, meniscus repair should be performed given the ability to restore native anatomy, provide high rates of RTS, and mitigate long-term chondral damage. However, partial meniscectomy can be indicated for unrepairable tears.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38845301

RESUMO

Metastasis to the brain is a frequent complication of advanced melanoma. Historically, patients with melanoma brain metastasis (MBM) have had dismal outcomes, but outcomes have improved with the development of more effective treatments, including stereotactic radiosurgery and effective immune and targeted therapies. Despite these advances, MBM remains a leading cause of death from this disease, and many therapies show decreased efficacy against these tumors compared with extracranial metastases. This differential efficacy may be because of recently revealed unique molecular and immune features of MBMs-which may also provide rational new therapeutic strategies.

3.
Free Radic Biol Med ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38848786

RESUMO

The oxidative phase of the pentose phosphate pathway (PPP) involving the enzymes glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconolactonase (6PGL), and 6-phosphogluconate dehydrogenase (6PGDH), is critical to NADPH generation within cells, with these enzymes catalyzing the conversion of glucose-6-phosphate (G6P) into ribulose-5-phosphate (Ribu5-P). We have previously studied peroxyl radical (ROO•) mediated oxidative inactivation of E. coli G6PDH, 6PGL, and 6PGDH. However, these data were obtained from experiments where each enzyme was independently exposed to ROO•, a condition not reflecting biological reality. In this work we investigated how NADPH production is modulated when these enzymes are jointly exposed to ROO•. Enzyme mixtures (1:1:1 ratio) were exposed to ROO• produced from thermolysis of 100 mM 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH). NADPH was quantified at 340 nm, and protein oxidation analyzed by liquid chromatography with mass spectrometric detection (LC-MS). The data obtained were rationalized using a mathematical model. The mixture of non-oxidized enzymes, G6P and NADP+ generated ∼175 µM NADPH. Computational simulations showed a constant decrease of G6P associated with NADPH formation, consistent with experimental data. When the enzyme mixture was exposed to AAPH (3 h, 37 ºC), lower levels of NADPH were detected (∼100 µM) which also fitted with computational simulations. LC-MS analyses indicated modifications at Tyr, Trp, and Met residues but at lower concentrations than detected for the isolated enzymes. Quantification of NADPH generation showed that the pathway activity was not altered during the initial stages of the oxidations, consistent with a buffering role of G6PDH towards inactivation of the oxidative phase of the pathway.

4.
Front Immunol ; 15: 1397579, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38835755

RESUMO

Background: Yersinia pestis is the etiological agent of plague, which can manifest as bubonic, septicemic, and/or pneumonic disease. Plague is a severe and rapidly progressing illness that can only be successfully treated with antibiotics initiated early after infection. There are no FDA-approved vaccines for plague, and some vaccine candidates may be less effective against pneumonic plague than bubonic plague. Y. pestis is not known to impact males and females differently in mechanisms of pathogenesis or severity of infection. However, one previous study reported sex-biased vaccine effectiveness after intranasal Y. pestis challenge. As part of developing a safe and effective vaccine, it is essential that potential sex differences are characterized. Methods: In this study we evaluated novel vaccines in male and female BALB/c mice using a heterologous prime-boost approach and monitored survival, bacterial load in organs, and immunological correlates. Our vaccine strategy consisted of two subcutaneous immunizations, followed by challenge with aerosolized virulent nonencapsulated Y. pestis. Mice were immunized with a combination of live Y. pestis pgm- pPst-Δcaf1, live Y. pestis pgm- pPst-Δcaf1/ΔyopD, or recombinant F1-V (rF1-V) combined with adjuvants. Results: The most effective vaccine regimen was initial priming with rF1-V, followed by boost with either of the live attenuated strains. However, this and other strategies were more protective in female mice. Males had higher bacterial burden and differing patterns of cytokine expression and serum antibody titers. Male mice did not demonstrate synergy between vaccination and antibiotic treatment as repeatedly observed in female mice. Conclusions: This study provides new knowledge about heterologous vaccine strategies, sex differences in plague-vaccine efficacy, and the immunological factors that differ between male and female mice.


Assuntos
Camundongos Endogâmicos BALB C , Vacina contra a Peste , Peste , Yersinia pestis , Animais , Feminino , Peste/prevenção & controle , Peste/imunologia , Masculino , Yersinia pestis/imunologia , Vacina contra a Peste/imunologia , Vacina contra a Peste/administração & dosagem , Camundongos , Anticorpos Antibacterianos/sangue , Caracteres Sexuais , Fatores Sexuais , Modelos Animais de Doenças , Eficácia de Vacinas
5.
Sci Signal ; 17(840): eadn8376, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861613

RESUMO

Uveal melanoma (UM) is the deadliest form of eye cancer in adults. Inactivating mutations and/or loss of expression of the gene encoding BRCA1-associated protein 1 (BAP1) in UM tumors are associated with an increased risk of metastasis. To investigate the mechanisms underlying this risk, we explored the functional consequences of BAP1 deficiency. UM cell lines expressing mutant BAP1 grew more slowly than those expressing wild-type BAP1 in culture and in vivo. The ability of BAP1 reconstitution to restore cell proliferation in BAP1-deficient cells required its deubiquitylase activity. Proteomic analysis showed that BAP1-deficient cells had decreased phosphorylation of ribosomal S6 and its upstream regulator, p70S6K1, compared with both wild-type and BAP1 reconstituted cells. In turn, expression of p70S6K1 increased S6 phosphorylation and proliferation of BAP1-deficient UM cells. Consistent with these findings, BAP1 mutant primary UM tumors expressed lower amounts of p70S6K1 target genes, and S6 phosphorylation was decreased in BAP1 mutant patient-derived xenografts (PDXs), which grew more slowly than wild-type PDXs in the liver (the main metastatic site of UM) in mice. BAP1-deficient UM cells were also more resistant to amino acid starvation, which was associated with diminished phosphorylation of S6. These studies demonstrate that BAP1 deficiency slows the proliferation of UM cells through regulation of S6 phosphorylation. These characteristics may be associated with metastasis by ensuring survival during amino acid starvation.


Assuntos
Proliferação de Células , Melanoma , Transdução de Sinais , Proteínas Supressoras de Tumor , Ubiquitina Tiolesterase , Neoplasias Uveais , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Mutação , Fosforilação , Proteína S6 Ribossômica/metabolismo , Proteína S6 Ribossômica/genética , Estresse Fisiológico , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Neoplasias Uveais/genética , Neoplasias Uveais/metabolismo , Neoplasias Uveais/patologia , Feminino
6.
Cancers (Basel) ; 16(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38893272

RESUMO

Sortilin is an important regulator with potential tumour-suppressor function by limiting EGFR signalling. In this study, we undertook a comprehensive expression analysis of sortilin transcript variants and the DNA methylation status of their corresponding promoters in human non-small cell carcinomas (NSCLCs). RNA/DNA was extracted from 81 NSCLC samples and paired normal tissue. mRNA expression was measured by qPCR and DNA methylation determined by pyrosequencing. BigDye-terminator sequencing was used to confirm exon-8 alternative splicing. Results demonstrated that both SORT1A and SORT1B variants were downregulated in lung tumours. The SORT1A/SORT1B expression ratio was higher in tumours compared to normal tissue. SORT1B promoter hypermethylation was detected in lung tumours compared to normal lung (median difference 14%, Mann-Whitney test p = 10-6). Interestingly, SORT1B is hypermethylated in white blood cells, but a small and very consistent drop in methylation (6%, p = 10-15) was observed in the lung cancer cases compared to control subjects. We demonstrate that the SORT1B exon-8 splice variation, reported in sequence databases, is also a feature of SORT1A. The significantly altered quantitative and qualitative characteristics of sortilin mRNA in NSCLC indicate a significant involvement in tumour pathogenesis and may have significant impact for its utility as a predictive marker in lung cancer management.

7.
Lancet Reg Health Eur ; 42: 100936, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38813535

RESUMO

Background: Lower socioeconomic status, as measured by the Index of Multiple Deprivation (IMD), is associated with higher rates of smoking-related disease mortality, and with poor uptake of cancer screening. Here we explore whether socioeconomic status impacts the effectiveness of a single round of low-dose-CT screening, or impacts other causes of death, in the UKLS LDCT screening trial. Methods: IMD quintiles were defined according to UK-wide data, with the deprived group defined as the lower two quintiles (Q1-2) and the less deprived as Q3-5. Follow-up data was obtained for lung cancer diagnosis (median follow-up 9.1 years) and cause of death (median follow-up 9.9 years). Outcomes were compared based on IMD group and trial arm (CT or control). Findings: More deprived quintiles were less likely to respond to the questionnaire, but this population was more likely to be selected for screening by the LLP risk model. Lower IMD quintiles benefitted from low-dose-CT screening in terms of lung cancer survival (HR 1.89, 95% CI 1.16-3.08) to the same extent as upper quintiles (HR 1.87, 95% CI 1.07-3.26). However, there was a bigger impact on deaths due to COPD and emphysema in more deprived quintiles. Interpretation: Whilst LDCT screening benefit for lung cancer was similar, significant impact on the rates of death from other smoking-related diseases, notably COPD and emphysema, was seen primarily in lower socioeconomic groups. Future research is required to confirm how lung cancer screening benefits other disease outcomes. Funding: NIHR Health Technology Assessment Programme; NIHR Policy Research programme; Roy Castle Lung Cancer Foundation.

8.
J Orthop Res ; 2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38796742

RESUMO

Amibegron, a ß3-adrenergic receptor (B3AR) agonist, has recently been shown to provide therapeutic effects for chronic rotator cuff (RC) tears by inducing the expression of uncoupling protein 1 (UCP-1), a marker of brown fat, in fibroadipogenic progenitors (FAPs). However, it remains to be seen if these beneficial effects hold true with age and in older, more clinically relevant populations. This study seeks to understand the impacts of aging on the efficacy of amibegron to treat chronic RC tears. Young (4-month-old) and aged (33-month-old) C57BL/6 mice underwent a RC injury procedure with delayed repair (DR). Mice were equally randomized to receive amibegron or dimethyl sulfoxide (DMSO) treatments after repair. Functional ability was measured at baseline and 6-weeks after DR. Wet muscle weight and histology of injured and contralateral supraspinatus were also analyzed 6-weeks post-DR. For in vitro histology and real-time quantitative PCR experiments, FAPs were isolated from young and aged mice via fluorescence-activated cell sorting. Young and aged FAPs were treated with amibegron or DMSO either immediately after seeding (early exposure) or 8-days after seeding (late exposure). In vitro results showed that amibegron-mediated FAP UCP-1 expression decreases with age. In vivo data demonstrated that aged mice have a decreased responsiveness to amibegron and decreased propensity for intramuscular FAP UCP-1 expression. Further, delayed amibegron treatment with RC repair did not lead to improvements in muscle atrophy and functional outcomes. Our findings demonstrate that age and the timing of interventions play a critical role in FAP-targeted therapeutics for chronic injuries.

9.
Am J Dermatopathol ; 46(7): 410-415, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38718197

RESUMO

ABSTRACT: Acral lentiginous melanoma (ALM) is an aggressive type of cutaneous melanoma (CM) that arises on palms, soles, and nail units. ALM is rare in White population, but it is relatively more frequent in dark-skinned populations. There is an unmet need to develop new personalized and more effective treatments strategies for ALM. Increased expression of antiapoptotic proteins (ie, BCL2, MCL1) has been shown to contribute to tumorigenesis and therapeutic resistance in multiple tumor types and has been observed in a subset of ALM and mucosal melanoma cell lines in vivo and in vitro. However, little is known about their expression and clinical significance in patients with ALM. Thus, we assessed protein expression of BCL2, MCL1, BIM, and BRAF V600E by immunohistochemistry in 32 melanoma samples from White and Hispanic populations, including ALM and non-ALM (NALM). BCL2, MCL1, and BIM were expressed in both ALM and NALM tumors, and no significant differences in expression of any of these proteins were detected between the groups, in our relatively small cohort. There were no significant associations between protein expression and BRAF V600E status, overall survival, or ethnicity. In summary, ALM and NALM demonstrate frequent expressions of apoptosis-related proteins BCL2, MCL1, and BIM. Our findings suggest that patients with melanoma, including ALM, may be potential candidates for apoptosis-directed therapies.


Assuntos
Apoptose , Proteína 11 Semelhante a Bcl-2 , Biomarcadores Tumorais , Melanoma , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas Proto-Oncogênicas c-bcl-2 , Neoplasias Cutâneas , Humanos , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Masculino , Melanoma/patologia , Melanoma/genética , Melanoma/metabolismo , Feminino , Pessoa de Meia-Idade , Idoso , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína 11 Semelhante a Bcl-2/metabolismo , Proteína 11 Semelhante a Bcl-2/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/análise , Proteínas Proto-Oncogênicas B-raf/genética , Adulto , Imuno-Histoquímica , Idoso de 80 Anos ou mais
10.
Biochem Soc Trans ; 52(3): 1199-1217, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38778764

RESUMO

The extracellular matrix (ECM) is critical to biological architecture and determines cellular properties, function and activity. In many situations it is highly abundant, with collagens and elastin being some of the most abundant proteins in mammals. The ECM comprises of multiple different protein species and sugar polymers, with both different isoforms and post-translational modifications (PTMs) providing a large variety of microenvironments that play a key role in determining tissue structure and health. A number of the PTMs (e.g. cross-links) present in the ECM are critical to integrity and function, whereas others are deleterious to both ECM structure and associated cells. Modifications induced by reactive oxidants and electrophiles have been reported to accumulate in some ECM with increasing age. This accumulation can be exacerbated by disease, and in particular those associated with acute or chronic inflammation, obesity and diabetes. This is likely to be due to higher fluxes of modifying agents in these conditions. In this focused review, the role and effects of oxidants and other electrophiles on ECM are discussed, with a particular focus on the artery wall and atherosclerotic cardiovascular disease. Modifications generated on ECM components are reviewed, together with the effects of these species on cellular properties including adhesion, proliferation, migration, viability, metabolic activity, gene expression and phenotype. Increasing data indicates that ECM modifications are both prevalent in human and mammalian tissues and play an important role in disease development and progression.


Assuntos
Proteínas da Matriz Extracelular , Oxidantes , Processamento de Proteína Pós-Traducional , Humanos , Proteínas da Matriz Extracelular/metabolismo , Animais , Oxidantes/metabolismo , Matriz Extracelular/metabolismo
11.
mBio ; 15(6): e0082924, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38771046

RESUMO

Nontuberculous mycobacteria (NTM) are environmentally ubiquitous organisms that predominately cause NTM pulmonary disease (NTMPD) in individuals over the age of 65. The incidence of NTMPD has increased in the U.S., exceeding that of Mycobacterium tuberculosis. However, the mechanisms leading to higher susceptibility and severity of NTMPD with aging are poorly defined in part due to the lack of animal models that accurately recapitulate human disease. Here, we compared bacterial load, microbial communities, and host responses longitudinally between three young (two female and one male) and two aged (two female) rhesus macaques inoculated with Mycobacterium avium subsp. hominissuis (MAH) in the right caudal lobe. Unilateral infection resulted in a low bacterial load in both young and aged animals confined to the infected side. Although a robust inflammatory response was only observed in the inoculated lung, immune cell infiltration and antigen-specific T cells were detected in both lungs. Computed tomography, gross pathology, and histopathology revealed increased disease severity and persistence of bacterial DNA in aged animals. Additional analyses showed the translocation of gut and oral-pharyngeal bacterial DNA into the lower respiratory microbiome. Finally, single-cell RNA sequencing revealed a heightened inflammatory response to MAH infection by alveolar macrophages in aged animals. These data are consistent with the model that increased disease severity in the aged is mediated by a dysregulated macrophage response that may be sustained through persistent antigen presence. IMPORTANCE: Nontuberculous mycobacteria (NTM) are emerging as pathogens of high consequence, as cases of NTM pulmonary disease (NTMPD) have exceeded those of Mycobacterium tuberculosis. NTMPD can be debilitating, particularly in patients over 65 years of age, as it causes chronic cough and fatigue requiring prolonged treatments with antibiotics. The underlying mechanisms of this increased disease severity with age are poorly understood, hampering the development of therapeutics and vaccines. Here, we use a rhesus macaque model to investigate the impact of age on host-NTM interactions. This work shows that aging is associated with increased disease severity and bacterial persistence in aged rhesus macaques, thus providing a preclinical model to develop and test novel therapeutics and interventions.


Assuntos
Pulmão , Macaca mulatta , Infecções por Mycobacterium não Tuberculosas , Infecções por Mycobacterium não Tuberculosas/diagnóstico por imagem , Infecções por Mycobacterium não Tuberculosas/imunologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Pulmão/diagnóstico por imagem , Pulmão/imunologia , Pulmão/microbiologia , Animais , Masculino , Feminino , Fatores Etários , Tomografia Computadorizada por Raios X , Transcriptoma , Microbiota/fisiologia
12.
Neurooncol Adv ; 6(1): vdae033, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725995

RESUMO

Background: POLARIS (phase 2 [ph2]; NCT03911869) evaluated encorafenib (BRAF inhibitor) in combination with binimetinib (MEK1/2 inhibitor) in BRAF/MEK inhibitor-naïve patients with BRAF V600-mutant melanoma with asymptomatic brain metastases. Methods: The safety lead-in (SLI) assessed tolerability for high-dose encorafenib 300 mg twice daily (BID) plus binimetinib 45 mg BID. If the high dose was tolerable in ph2, patients would be randomized to receive high or standard dose (encorafenib 450 mg once daily [QD] plus binimetinib 45 mg BID). Otherwise, standard dose was evaluated as the recommended ph2 dose (RP2D). Patients who tolerated standard dosing during Cycle 1 could be dose escalated to encorafenib 600 mg QD plus binimetinib 45 mg BID in Cycle 2. Safety, efficacy, and pharmacokinetics were examined. Results: RP2D was standard encorafenib dosing, as >33% of evaluable SLI patients (3/9) had dose-limiting toxicities. Overall, of 13 safety-evaluable patients (10 SLI, 3 ph2), 9 had prior immunotherapy. There were 9 treatment-related adverse events in the SLI and 3 in ph2. Of the SLI efficacy-evaluable patients (n = 10), 1 achieved complete response and 5 achieved partial responses (PR); the brain metastasis response rate (BMRR) was 60% (95% CI: 26.2, 87.8). In ph2, 2 of 3 patients achieved PR (BMRR, 67% [95% CI: 9.4, 99.2]). Repeated encorafenib 300 mg BID dosing did not increase steady-state exposure compared with historical 450 mg QD data. Conclusions: Despite small patient numbers due to early trial termination, BMRR appeared similar between the SLI and ph2, and the ph2 safety profile appeared consistent with previous reports of standard-dose encorafenib in combination with binimetinib.

13.
Mol Cancer Ther ; 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38641411

RESUMO

Although patient-derived xenografts (PDXs) are commonly used for preclinical modeling in cancer research, a standard approach to in vivo tumor growth analysis and assessment of antitumor activity is lacking, complicating comparison of different studies and determination of whether a PDX experiment has produced evidence needed to consider a new therapy promising. We present consensus recommendations for assessment of PDX growth and antitumor activity, providing public access to a suite of tools for in vivo growth analyses. We expect that harmonizing PDX study design and analysis and access to a suite of analytical tools will enhance information exchange and facilitate identification of promising novel therapies and biomarkers for guiding cancer therapy.

14.
Endocrinology ; 165(7)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38608138

RESUMO

Clomiphene citrate is a common treatment for ovulation induction in subfertile women, but its use is associated with elevated risk of adverse perinatal outcomes and birth defects. To investigate the biological plausibility of a causal relationship, this study investigated the consequences in mice for fetal development and pregnancy outcome of periconception clomiphene citrate administration at doses approximating human exposures. A dose-dependent adverse effect of clomiphene citrate given twice in the 36 hours after mating was seen, with a moderate dose of 0.75 mg/kg sufficient to cause altered reproductive outcomes in 3 independent cohorts. Viable pregnancy was reduced by 30%, late gestation fetal weight was reduced by 16%, and ∼30% of fetuses exhibited delayed development and/or congenital abnormalities not seen in control dams, including defects of the lung, kidney, liver, eye, skin, limbs, and umbilicus. Clomiphene citrate also caused a 30-hour average delay in time of birth, and elevated rate of pup death in the early postnatal phase. In surviving offspring, growth trajectory tracking and body morphometry analysis at 20 weeks of age showed postweaning growth and development similar to controls. A dysregulated inflammatory response in the endometrium was observed and may contribute to the underlying pathophysiological mechanism. These results demonstrate that in utero exposure to clomiphene citrate during early pregnancy can compromise implantation and impact fetal growth and development, causing adverse perinatal outcomes. The findings raise the prospect of similar iatrogenic effects in women where clomiphene citrate may be present in the periconception phase unless its use is well-supervised.


Assuntos
Clomifeno , Clomifeno/efeitos adversos , Clomifeno/administração & dosagem , Animais , Feminino , Gravidez , Camundongos , Desenvolvimento Fetal/efeitos dos fármacos , Fármacos para a Fertilidade Feminina/efeitos adversos , Fármacos para a Fertilidade Feminina/administração & dosagem , Masculino , Resultado da Gravidez , Camundongos Endogâmicos C57BL , Morte Fetal , Indução da Ovulação/métodos
16.
Eur J Pharm Sci ; 197: 106774, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38641123

RESUMO

BACKGROUND: Preclinical models of cancer can be of translational benefit when assessing how different biomarkers are regulated in response to particular treatments. Detection of molecular biomarkers in preclinical models of cancer is difficult due inter-animal variability in responses, combined with limited accessibility of longitudinal data. METHODS: Nonlinear mixed-effects modelling (NLME) was used to analyse tumour growth data based on expected tumour growth rates observed 7 days after initial doses (DD7) of Radiotherapy (RT) and Combination of RT with DNA Damage Response Inhibitors (DDRi). Cox regression was performed to confirm an association between DD7 and survival. Hierarchical Cluster Analysis (HCA) was then used to identify candidate biomarkers impacting responses to RT and RT/DDRi and these were validated using NLME. RESULTS: Cox regression confirmed significant associations between DD7 and survival. HCA of RT treated samples, combined with NLME confirmed significant associations between DD7 and Cluster specific CD8+ Ki67 MFI, as well as DD7 and cluster specific Natural Killer cell density in RT treated mice. CONCLUSION: Application of NLME, as well as HCA of candidate biomarkers may provide additional avenues to assess the effect of RT in MC38 syngeneic tumour models. Additional studies would need to be conducted to confirm association between DD7 and biomarkers in RT/DDRi treated mice.


Assuntos
Biomarcadores Tumorais , Dinâmica não Linear , Animais , Análise por Conglomerados , Biomarcadores Tumorais/metabolismo , Camundongos , Neoplasias/metabolismo , Feminino , Camundongos Endogâmicos C57BL , Linhagem Celular Tumoral , Dano ao DNA , Modelos Animais de Doenças
17.
Free Radic Biol Med ; 220: 207-221, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38663830

RESUMO

At inflammatory sites, immune cells generate oxidants including H2O2. Myeloperoxidase (MPO), released by activated leukocytes employs H2O2 and halide/pseudohalides to form hypohalous acids that mediate pathogen killing. Hypochlorous acid (HOCl) is a major species formed. Excessive or misplaced HOCl formation damages host tissues with this linked to multiple inflammatory diseases. Previously (Redox Biology, 2020, 28, 101331) we reported that iodide (I⁻) modulates MPO-mediated protein damage by decreasing HOCl generation with concomitant hypoiodous acid (HOI) formation. HOI may however impact on protein structure, so in this study we examined whether and how HOI, from peroxidase/H2O2/I⁻ systems ± Cl⁻, modifies proteins. Experiments employed MPO and lactoperoxidase (LPO) and multiple proteins (serum albumins, anastellin), with both chemical (intact protein and peptide mass mapping, LC-MS) and structural (SDS-PAGE) changes assessed. LC-MS analyses revealed dose-dependent iodination of anastellin and albumins by LPO/H2O2 with increasing I⁻. Incubation of BSA with MPO/H2O2/Cl⁻ revealed modest chlorination (Tyr286, Tyr475, ∼4 %) and Met modification. Lower levels of these species, and extensive iodination at specific Tyr and His residues (>20 % modification with ≥10 µM I⁻) were detected with increasing I⁻. Anastellin dimerization was inhibited by increasing I⁻, but less marked changes were observed with albumins. These data confirm that I⁻ competes with Cl⁻ for MPO and is an efficient HOCl scavenger. These processes decrease protein chlorination and oxidation, but result in extensive iodination. This is consistent with published data on the presence of iodinated Tyr on neutrophil proteins. The biological implications of protein iodination relative to chlorination require further clarification.


Assuntos
Halogenação , Peróxido de Hidrogênio , Ácido Hipocloroso , Iodetos , Lactoperoxidase , Peroxidase , Peroxidase/metabolismo , Iodetos/metabolismo , Iodetos/química , Humanos , Lactoperoxidase/metabolismo , Lactoperoxidase/química , Ácido Hipocloroso/metabolismo , Peróxido de Hidrogênio/metabolismo , Oxirredução , Compostos de Iodo
19.
Artigo em Inglês | MEDLINE | ID: mdl-38441906

RESUMO

Introduction: Sodium glucose cotransporter inhibitors may increase beta-hydroxybutyrate (BHB) in insulin-requiring patients. We determined factors associated with BHB changes from baseline (ΔBHB) and diabetic ketoacidosis (DKA) in patients with type 1 diabetes (T1D) receiving sotagliflozin as an insulin adjunct. Research Design and Methods: This post hoc analysis compared ΔBHB levels in adults with T1D receiving sotagliflozin 400 mg or placebo for 6 months. We evaluated clinical and metabolic factors associated with ΔBHB and used logistic regression models to determine predictors associated with BHB values >0.6 and >1.5 mmol/L (inTandem3 population; N = 1402) or with DKA events in a pooled analysis (inTandem1-3; N = 2453). Results: From baseline (median, 0.13 mmol/L), median fasting BHB increased by 0.04 mmol/L (95% confidence interval, 0.03-0.05; P < 0.001) at 24 weeks with sotagliflozin versus placebo; 67% of patients had no or minimal changes in BHB over time. Factors associated with on-treatment BHB >0.6 or >1.5 mmol/L included baseline BHB and sotagliflozin use. Age, insulin pump use, sotagliflozin use, baseline BHB, and ΔBHB were significantly associated with DKA episodes. Independent of treatment, DKA risk increased by 18% with each 0.1-mmol/L increase in baseline BHB and by 8% with each 0.1-mmol/L increase from baseline. Conclusion: Incremental increases in baseline BHB and ΔBHB were associated with a higher DKA risk independent of treatment. Adding sotagliflozin to insulin increased median BHB over 24 weeks in patients with T1D and was associated with increased DKA events. These results highlight the importance of BHB testing and monitoring and individualizing patient education on DKA risk, mitigation, identification, and treatment.

20.
Colorectal Dis ; 26(5): 871-885, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38527938

RESUMO

AIM: The aim of this work was to evaluate the safety and feasibility of performing colonoscopy in patients aged 90 years or over. METHOD: In compliance with PRISMA statement standards, a systematic review of studies reporting the outcomes of colonoscopy in patients aged ≥90 years was conducted. A proportional meta-analysis model was constructed to quantify the risk of outcomes and a direct comparison meta-analysis model was constructed to compare outcomes between nonagenarians and patients aged between 50 and 89 years via random-effects models. RESULTS: Seven studies enrolling 1304 patients (1342 colonoscopies) were included. Analyses showed that complications related to bowel preparation occurred in 0.7% (95% CI 0.1%-1.6%), procedural complications in 0.6% (0.00%-1.7%), 30-day complications in 1.5% (0.6%-2.7%), procedural mortality in 0.3% (0.0%-1.1%) and 30-day mortality in 1.1% (0.3%-2.2%). Adequate bowel preparation and colonoscopy completion were achieved in 81.3% (73.8%-87.9%) and 92.1% (86.7%-96.3%), respectively. No difference was found in bowel preparation-related complications [risk difference (RD) 0.00, p = 0.78], procedural complications (RD 0.00, p = 0.60), 30-day complications (RD 0.01, p = 0.20), procedural mortality (RD 0.00, p = 1.00) or 30-day mortality (RD 0.01, p = 0.34) between nonagenarians and patients aged between 50 and 89 years. The colorectal cancer detection rate was 14.3% (9.8%-19.5%), resulting in therapeutic intervention in 65.9% (54.5%-76.6%). CONCLUSIONS: Although the evidence is limited to a selected group of nonagenarians, it may be fair to conclude that if a colonoscopy is indicated in a nonagenarian with good performance status (based on initial less-invasive investigations), the level 2 evidence supports its safety and feasibility. Age on its own should not be a reason for failing to offer colonoscopy to a nonagenarian.


Assuntos
Colonoscopia , Estudos de Viabilidade , Humanos , Colonoscopia/efeitos adversos , Colonoscopia/métodos , Colonoscopia/estatística & dados numéricos , Idoso de 80 Anos ou mais , Fatores Etários , Feminino , Masculino , Pessoa de Meia-Idade , Análise de Regressão
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