Mitochondrial Function in Oxidative and Glycolytic Bovine Skeletal Muscle Postmortem

ObjectivesMitochondrial function in postmortem muscle is affected by decreasing oxygenation. Functional properties relating to energy production and integrity of mitochondria may influence development of meat quality characteristics. Therefore, the objective was to evaluate changes in mitochondrial function in oxidative and glycolytic muscles during the first 24h postmortem.Materials and MethodsSteers (n = 6) of primarily Angus (80 to 100%) genetics were harvested at approximately 18.5 mo and 630 kg live weight. Samples from the longissimus lumborum (LL) and diaphragm (Dia) were collected at 1, 3, and 24h postmortem. Fresh-preserved muscle samples were permeabilized using saponin, and muscle bundles (2–4 mg) were transferred to a high-resolution oxygraph for respiration measurements (oxygen consumption rate, OCR, pmol/sec/mg of tissue). Samples were assessed in duplicate under hyperoxia. First, pyruvate and malate were added to support the TCA cycle and assess leak respiration. Then, ADP was added to support electron flow through complex I. The influence of glutamate on NADH production (complex I) was tested, followed by complex II activation by succinate. Integrity of the mitochondria outer membrane was tested with cytochrome c. Next, an uncoupler (FCCP) was added to force the electron transport system (ETS) to maximum capacity. Citrate synthase (CS) activity (nmol/min/mg tissue) was determined in frozen samples and used as a marker of mitochondria content. Subsequently, respiration data were normalized to CS activity (pmol/sec/U CS) to account for differences in mitochondria content. Coupling efficiency of oxidative phosphorylation was calculated as 1– (Leak/ADP-stimulated oxidative phosphorylation capacity). Raw and normalized OCR were analyzed in a randomized block design, with slaughter date as block and fixed effects of muscle, time, and the interaction. Time was considered a repeated measure.ResultsMuscle type affected (P = 0.0002) leak OCR, with Dia showing a higher rate than LL. After ADP was added, mitochondria from Dia exhibited higher OCR at all times tested and at all steps, with OCR being 4 times higher after FCCP addition. Mitochondrial content, evidenced by greater (P < 0.0001) CS activity in Dia, largely explained differences in OCR between muscles. After OCR was normalized to CS activity, the 1 and 3h postmortem OCR from Dia and LL were similar (P > 0.05). However, at 24h postmortem, OCR after ADP, glutamate, and FCCP additions were greater (P < 0.05) in Dia mitochondria. Time, but not muscle, affected cytochrome c response. At 1h postmortem, cytochrome c increased OCR by 6.6%, supporting that mitochondria outer membrane integrity is not compromised. However, cytochrome c response at 3h postmortem increased 52.4%, indicating outer membrane damage. Coupling efficiency is different between muscles (P = 0.005) with Dia exhibiting greater efficiency.ConclusionDespite inherent metabolic differences between the LL and Dia, mitochondria from both muscles are intact and coupled at 1h postmortem. However, by 24h postmortem, functional properties of LL mitochondria are reduced compared to Dia. Declining mitochondrial function may be associated with calcium overload, mitochondrial fragmentation, and protease activation.

Abstract P1-08-33: Molecular breast cancer subtypes in a Guatemalan population. Classification according to immunohistochemical markers: Clinicopathologic feature and survival analysis

Introduction: Breast cancer is a heterogeneous malignancy and it's possible to identify by simple techniques, such as inmmunohistochemistry, four subtypes with different clinical and biological behavior. Our aim was to evaluate the influence of these subtypes on the local and distant recurrences rates.

Method: data of 954 unilateral breast cancer patients primarily treated with radical or conservative surgery from 2008 to 2014 were obtained from medical records. Breast cancer subtypes were categorized in Luminal A (RE+ and/or RP+, HER2-), Luminal B (RE+ and/or RP+, HER2+ o Ki-67&gt; 14%); HER2 (RE-, RP-, HER2+) and triple negative tumors (TNT) (RE-, RP-, HER2-). Patterns of recurrence for each subtype and clinicopathological variables and the influence of each variable on the overall survival (OS) by the Kaplan-Meier method. In all cases, we determined histological type, grade nuclear (low, intermediate vrs high), tumor size, lymph node involvement

Results: Median age at diagnosis was 52 years (range, 23-95). Of these patients 55% were premenopausal. We found that 522 (56%) of the cases were luminal A breast cancer, 190 (20%) of the cases were triple negative tumors (TNT), luminal B were 73 (8%) and it was HER2-positive in 152 (20%) of cases. Nine patients (3%) had other breast cancer contralateral. In 70% of all the cases were found in locally advanced stages (IIB – IIIC). In 438 (70%) of all the cases were found in locally advanced stages (IIB – IIIC), 773 (81%) patients underwent radical mastectomy and 181 (19%) undergoing conservative surgery. We performed univariate analysis to evaluate recurrence-related factors. Variables included in the analysis clinical stage (I – IIa vs IIb – IIIC; 88% vs 70%; p = 0.001, ), nuclear grade (grade 1, 2 vs 3; 83% vs 62%; p = 0.01) and pathologic response (total vs parcial, stable disease; 76% vs 54%; p = 0.01), and status Her-2 subtype so borderline (positive vs negative; p= 0.079). A univariate survival analysis stratification according to clinicapathologic characteristics. Clinical stage, histologic grade, response to neoadjuvant and tumor size were identified as significant factors of prognosis for the OS. (p=0.5) and histological subtypes Luminal A (94%), Luminal B (75%), HER2 (79%) and TNT (68%), p= 0.001.

Conclusion: this study demonstrates that treatment efficacy is similar to that reported in the literature and emphasizes the need for establishing the molecular breast cancer subtypes and efforts should be made to reduce the high frequency of advanced-stage diagnoses.

Citation Format: Castro H, Garcia L, Jimenez F, Ramos P, Castro N. Molecular breast cancer subtypes in a Guatemalan population. Classification according to immunohistochemical markers: Clinicopathologic feature and survival analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-33.

Implication of non-coding PAX6 mutations in aniridia

There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Outcomes of oral lichen planus and oral lichenoid lesions treated with topical corticosteroid

OBJECTIVE

To determine corticosteroid treatment effectiveness in patients with oral lichen planus/oral lichenoid lesions (OLP/OLL).

MATERIAL AND METHODS

Twenty-one patients with OLP and eighty-one patients with OLL received 0.05% clobetasol propionate (CP) or 0.05% triamcinolone acetonide (TA) in aqueous solution (AS) or orabase (OB), evaluating responses to treatment and follow-up compliance.

RESULTS

Lesions were atrophic (72 of 102; 70.6%), extensive (58 of 100; 58%), producing eating difficulties (62 of 102; 60.8%), and spontaneous pain (30 of 102; 29.4%); 50 patients (49%) received CP-AS. The mean ± SD percentage of follow-ups attended was 43 ± 32%. Symptom remission was achieved in 46% of patients receiving CP-AS, 36.36% of those receiving TA-AS, 20% of those receiving CP-OB, and 25% of those receiving TA-OB. Follow-up compliance was poor in 66.7% of patients. Among 51 patients with continuous symptoms, 64.7% evidenced total remission at treatment completion; among 33 with intermittent symptoms, 73.1% had outbreaks 2-3 times/year and 51.5% controlled outbreaks with <6 corticosteroid applications. Adverse effects were observed in seven patients (6.8%) (moon face, hirsutism, capillary fragility) in induction stage, subsiding with dose; among 15 patients under maintenance treatment for >6 months, one showed hypothalamic-pituitary-adrenal (HPA) axis inhibition but not adrenal insufficiency.

CONCLUSIONS

Our treatment proved highly effective and safe. Recall programs are desirable to enhance follow-up compliance.

Effect of ultraviolet irradiation on free radical scavenging activity of immunosuppressants used in lung transplantation and comparative electron paramagnetic resonance study of kinetics of their interactions with model free radicals

WHAT IS KNOWN AND OBJECTIVE

The immunosuppressive drugs used in solid organ transplantation or autoimmunological processes were studied by electron paramagnetic resonance (EPR) spectroscopy to estimate their free radical scavenging activity. The interactions of immunosuppressants with free radicals were examined by an X-band (9.3 GHz) EPR spectroscopy and a model of DPPH free radicals.

METHODS

The EPR spectra of DPPH and DPPH interacting with individual drugs were compared. Kinetic studies were performed, and the effect of ultraviolet (UV) irradiation on the free radical scavenging activity of the tested drugs was determined.

RESULTS AND DISCUSSION

The free radical scavenging activity of non-irradiated drugs decreased in the order: rapamycin > mycophenolate mofetil > ciclosporin > tacrolimus. UV irradiation increased the free radical scavenging activity of all the tested immunosuppressive drugs, and the effect was highest for tacrolimus. For the non-irradiated samples, the speed of free radical interactions decreased in the order: ciclosporin > tacrolimus > mycophenolate mofetil > rapamycin. UV irradiation only slightly affected the speed of interactions of the immunosuppressive drugs with the model DPPH free radicals.

WHAT IS NEW AND CONCLUSION

Electron paramagnetic resonance spectroscopy is useful for obtaining information on interactions of immunosuppressive drugs with free radicals. We hypothesized that the long-term immunosuppressive effects of these drugs after transplantation or during autoimmune disorders may be mediated by anti-inflammatory action in addition to the known receptor/cell cycle inhibition.

[Factors determining patient satisfaction with the pre-anaesthesia consultation]

OBJECTIVE

To analyse patient satisfaction with care provided in the pre-anaesthetic consultation and its determining factors.

MATERIAL AND METHOD

An anonymous questionnaire was randomly distributed to patients attending a pre-anaesthesia clinic, which included 4 questions with 5 possible answers on a (very dissatisfied, dissatisfied, fairly satisfied, satisfied and very satisfied) categorical graduated scale related to punctuality, understanding of the information received, respectful treatment, and overall satisfaction. The fifth question was about the knowledge or the name of the anaesthesiologist who attended them. A binary logistic regression model was used, which identified the predictors of satisfaction, calculated the odds ratios, and their respective 95% confidence intervals.

RESULTS

A total of 4006 questionnaires were analysed, in which 99.2% (3966) of users rated as satisfied/very satisfied the question about the respectful treatment, 98.4% (3937) of the information received and understanding, 77.4% (3096) punctuality in attending, and 97, 6% (3909) overall satisfaction. Almost three-quarters (71%, 2844) did not know the name of the anaesthesiologist. Regression analysis associated the more satisfied with their treatment (OR 17.44; P<.0005) and the information received (OR 14.94, P<.0005), while punctuality (OR 5 40; P<.0005) was the factor that contributed less to the result.

CONCLUSION

In our population satisfaction in pre-anaesthesia consultation is due mainly to the communication skills of the anaesthesiologist.

Individual factors and school-based policies related to adherence to physical activity recommendations in Spanish adolescents

Our objective was to identify individual- and school-level contextual factors related to adherence to the recommendations for physical activity in adolescents. The study used a representative sample of 15,902 students from 328 schools aged 11-18 years participating in the Spanish Health Behaviour in School-aged Children (HBSC) survey 2006. In addition to the student questionnaire, the school management board completed a questionnaire about school-based policies related to physical activity. Adherence to the recommendations was defined as "having carried out moderate and/or vigorous physical activity for at least 60 min a day on five or more days during the last week". Analysis was undertaken using multilevel logistic regression models. Individual factors associated in a statistically significant way with a higher non-compliance were: being female; being older; immigrants; tobacco smoking; being overweight or obese; low consumption of fruit and vegetables; low level of satisfaction with life; not having a high level of academic achievement; and spending a lot of time studying. The family variables were: not undertaking sports activities with the family; low socioeconomic status; and a low level of satisfaction with family relationships. Compared with schools that have a low level of policies to promote physical activities, those with a high level of promotion had an odds ratio of 0.76 (CI 95 %, 0.61-0.94). In summary, irrespective of personal and family factors, students from schools with better policies of promotion of physical activity showed a higher compliance with the recommendations.

Spontaneous melanotic lesions in axillary seabream, Pagellus acarne (Risso)

In this article, we describe spontaneous melanotic lesions in the skin of axillary seabream, Pagellus acarne (Risso), from a defined area of the Portuguese Coast, located in Cabo da Roca and Foz do Arelho. The lesions corresponded to the black pigmentation spots on the skin of the head, fins, lips and conjunctiva and, additionally, black nodules on the skin of the head and lips. In some specimens, the nodular formations in the head changed their anatomical conformation. Histologically, there were melanophores scattered along the basement membrane or forming aggregates in the dermis, infiltrating the subcutaneous tissue but not invading the adjacent muscle tissue. The aim of this study was to characterize the macroscopic and microscopic features of the pigmented lesions. These fish show sessile hyperpigmented lesions (spots) that correspond to proliferative lesions of melanophores in the dermis and nodular lesions that correspond to neoplastic lesions, melanophoromas. The melanophores in such lesions showed high concentration of melanin in the cytoplasm, moderate pleomorphism and compact distribution throughout all of the dermis.

Physical activity and self-reported health status among adolescents: a cross-sectional population-based study

OBJECTIVES

Little is known about the dose-response relationship between physical activity and health benefits among young people. Our objective was to analyse the association between the frequency of undertaking moderate-to-vigorous physical activity (MVPA) and the self-reported health status of the adolescent population.

DESIGN

Cross-sectional study.

SETTING

All regions of Spain.

PARTICIPANTS

Students aged 11-18 years participating in the Spanish Health Behaviour in School-aged Children survey 2006. A total of 375 schools and 21 188 students were selected.

MAIN OUTCOMES

The frequency of undertaking MVPA was measured by a questionnaire, with the following four health indicators: self-rated health, health complaints, satisfaction with life and health-related quality of life. Linear and logistic regression models were used to analyse the association, adjusting for potential confounding variables and the modelling of the dose-response relationship.

RESULTS

As the frequency of MVPA increased, the association with health benefits was stronger. A linear trend (p<0.05) was found for self-rated health and health complaints in males and females and for satisfaction with life among females; for health-related quality of life this relationship was quadratic for both sexes (p<0.05). For self-reported health and health complaints, the effect was found to be of greater magnitude in males than in females and, in all scales, the benefits were observed from the lowest frequencies of MVPA, especially in males.

CONCLUSIONS

A protective effect of MVPA was found in both sexes for the four health indicators studied, and this activity had a gradient effect. Among males, health benefits were detected from very low levels of physical activity and the magnitude of the relationship was greater than that for females.