Human-induced pluripotent stem cell-derived ovarian support cell co-culture improves oocyte maturation in vitro after abbreviated gonadotropin stimulation

STUDY QUESTION

Can in vitro maturation (IVM) and developmental competence of human oocytes be improved by co-culture with ovarian support cells (OSCs) derived from human-induced pluripotent stem cells (hiPSCs)?

SUMMARY ANSWER

OSC-IVM significantly improves the rates of metaphase II (MII) formation and euploid Day 5 or 6 blastocyst formation, when compared to a commercially available IVM system.

WHAT IS KNOWN ALREADY

IVM has historically shown highly variable performance in maturing oocytes and generating oocytes with strong developmental capacity, while limited studies have shown a positive benefit of primary granulosa cell co-culture for IVM. We recently reported the development of OSCs generated from hiPSCs that recapitulate dynamic ovarian function in vitro.

STUDY DESIGN, SIZE, DURATION

The study was designed as a basic science study, using randomized sibling oocyte specimen allocation. Using pilot study data, a prospective sample size of 20 donors or at least 65 oocytes per condition were used for subsequent experiments. A total of 67 oocyte donors were recruited to undergo abbreviated gonadotropin stimulation with or without hCG triggers and retrieved cumulus-oocyte complexes (COCs) were allocated between the OSC-IVM or control conditions (fetal-like OSC (FOSC)-IVM or media-only IVM) in three independent experimental design formats. The total study duration was 1 April 2022 to 1 July 2023.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Oocyte donors between the ages of 19 and 37 years were recruited for retrieval after informed consent, with assessment of anti-Mullerian hormone, antral follicle count, age, BMI and ovarian pathology used for inclusion and exclusion criteria. In experiment 1, 27 oocyte donors were recruited, in experiment 2, 23 oocyte donors were recruited, and in experiment 3, 17 oocyte donors and 3 sperm donors were recruited. The OSC-IVM culture condition was composed of 100 000 OSCs in suspension culture with hCG, recombinant FSH, androstenedione, and doxycycline supplementation. IVM controls lacked OSCs and contained either the same supplementation, FSH and hCG only (a commercial IVM control), or FOSCs with the same supplementation (Media control). Experiment 1 compared OSC-IVM, FOSC-IVM, and a Media control, while experiments 2 and 3 compared OSC-IVM and a commercial IVM control. Primary endpoints in the first two experiments were the MII formation (i.e. maturation) rate and morphological quality assessment. In the third experiment, the fertilization and embryo formation rates were assessed with genetic testing for aneuploidy and epigenetic quality in blastocysts.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed a statistically significant improvement (∼1.5×) in maturation outcomes for oocytes that underwent IVM with OSCs compared to control Media-IVM and FOSC-IVM in experiment 1. More specifically, the OSC-IVM group yielded a MII formation rate of 68% ± 6.83% SEM versus 46% ± 8.51% SEM in the Media control (P = 0.02592, unpaired t-test). FOSC-IVM yielded a 51% ± 9.23% SEM MII formation rate which did not significantly differ from the media control (P = 0.77 unpaired t-test). Additionally, OSC-IVM yielded a statistically significant ∼1.6× higher average MII formation rate at 68% ± 6.74% when compared to 43% ± 7.90% in the commercially available IVM control condition (P = 0.0349, paired t-test) in experiment 2. Oocyte morphological quality between OSC-IVM and the controls did not significantly differ. In experiment 3, OSC-IVM oocytes demonstrated a statistically significant improvement in Day 5 or 6 euploid blastocyst formation per COC compared to the commercial IVM control (25% ± 7.47% vs 11% ± 3.82%, P = 0.0349 logistic regression). Also in experiment 3, the OSC-treated oocytes generated blastocysts with similar global and germline differentially methylated region epigenetic profiles compared commercial IVM controls or blastocysts after either conventional ovarian stimulation.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

While the findings of this study are compelling, the cohort size remains limited and was powered on preliminary pilot studies, and the basic research nature of the study limits generalizability compared to randomized control trials. Additionally, use of hCG-triggered cycles results in a heterogenous oocyte cohort, and potential differences in the underlying maturation state of oocytes pre-IVM may limit or bias findings. Further research is needed to clarify and characterize the precise mechanism of action of the OSC-IVM system. Further research is also needed to establish whether these embryos are capable of implantation and further development, a key indication of their clinical utility.

WIDER IMPLICATIONS OF THE FINDINGS

Together, these findings demonstrate a novel approach to IVM with broad applicability to modern ART practice. The controls used in this study are in line with and have produced similar to findings to those in the literature, and the outcome of this study supports findings from previous co-culture studies that found benefits of primary granulosa cells on IVM outcomes. The OSC-IVM system shows promise as a highly flexible IVM approach that can complement a broad range of stimulation styles and patient populations. Particularly for patients who cannot or prefer not to undergo conventional gonadotropin stimulation, OSC-IVM may present a viable path for obtaining developmentally competent, mature oocytes.

STUDY FUNDING/COMPETING INTEREST(S)

A.D.N., A.B.F., A.G., B.P., C.A., C.C.K., F.B., G.R., K.S.P., K.W., M.M., P.C., S.P., and M.-J.F.-G. are shareholders in the for-profit biotechnology company Gameto Inc. P.R.J.F. declares paid consultancy for Gameto Inc. P.C. also declares paid consultancy for the Scientific Advisory Board for Gameto Inc. D.H.M. has received consulting services from Granata Bio, Sanford Fertility and Reproductive Medicine, Gameto, and Buffalo IVF, and travel support from the Upper Egypt Assisted Reproduction Society. C.C.K., S.P., M.M., A.G., B.P., K.S.P., G.R., and A.D.N. are listed on a patent covering the use of OSCs for IVM: U.S. Provisional Patent Application No. 63/492,210. Additionally, C.C.K. and K.W. are listed on three patents covering the use of OSCs for IVM: U.S. Patent Application No. 17/846,725, U.S Patent Application No. 17/846,845, and International Patent Application No.: PCT/US2023/026012. C.C.K., M.P.S., and P.C. additionally are listed on three patents for the transcription factor-directed production of granulosa-like cells from stem cells: International Patent Application No.: PCT/US2023/065140, U.S. Provisional Application No. 63/326,640, and U.S. Provisional Application No. 63/444,108. The remaining authors have no conflicts of interest to declare.

Understanding Burnout Among US Radiation Oncology Residents

PURPOSE/OBJECTIVE(S)

Burnout is a significant concern among medical residents in the United States, including those in radiation oncology. This study aims to understand the extent of burnout among radiation oncology residents and identify modifiable factors within program structure and benefits that may help improve overall wellness and reduce burnout.

MATERIALS/METHODS

A Qualtrics-based survey was administered to US radiation oncology program directors and coordinators, utilizing contact information gathered in FREIDA, with a request to forward to all residents. The survey included questions on benefits and program structure as well as the Maslach Burnout Inventory. Data was analyzed using descriptive statistics.

RESULTS

To date, 82 of 736 residents (11.1%) completed the survey with representation from all PGY-levels. Median participant age was 31, and 53% identified as male. 20% of surveyed residents feel emotionally drained from work a few times a week and 6% feel emotionally drained daily. 59% feel burned out from work at least a few times a month, with 6% feeling burned out daily. Despite this, 85% feel they are positively influencing other people's lives through their work at least weekly and 77% feel they have accomplished many worthwhile things in this job at least weekly. 65% have salaries between $60,000-$74,999, and 35% have the opportunity to moonlight for supplemental income. 49% have 3 weeks of vacation and 48% have 4 weeks. 27% reported their department had funded wellness events. 61% reported dual coverage rotations, with 40% requiring coverage of multiple attendings in one day. 65% reported protected academic time on all rotations, and 7% have no protected academic time. 48% of respondents have 12 months of research time. 85% and 36% of those with research and protected academic time, respectively, can complete this off-site. Respondent concerns include the job market (62%), declining personal fertility in residency (46%), and cost of living (40%). The most reported ways to decrease stress and anxiety were exercise (35%), a strong support system (34%), and spirituality (10%). Increased salary was identified as the top benefit that could improve wellness by 41 residents, while retirement matching (32), paid gym memberships (23), a personal wellness stipend (30), and free/subsidized childcare (16) were also ranked among the top 5 benefit changes that could improve wellness. Increased mid-level support (16), more protected academic time during the week (15), and flexibility with work location during academic/research time (13) were the top aspects of program structure that were reported as opportunities to improve wellness.

CONCLUSION

Burnout is prevalent among US radiation oncology residents, and changes to residency programs and expanded institutional benefits are strongly perceived as the key components to improved resident wellness. This study highlights the need for further investigation into the root causes of burnout and the development of evidence-based strategies.

Quantifying the intensity of adverse events with ibuprofen and oxycodone: an observational cohort study

OBJECTIVE

To quantify the frequency and intensity of adverse events (AEs), commonly known as side effects, experienced by children receiving either ibuprofen or oxycodone for pain management following an acute fracture. Secondary objectives were to quantify functional outcome impairment and describe demographic and clinical characteristics associated with AEs.

DESIGN

Observational cohort study.

SETTING

Paediatric emergency department.

PATIENTS

Patients (n=240) aged 4-16 years diagnosed with an acute fracture.

INTERVENTION

Prescribed either ibuprofen (n=179) or oxycodone (n=61) for pain.

MAIN OUTCOME MEASURES

Families were called for the first 3 days after discharge to report the presence and intensity of AEs and their child's functional outcomes (ability to eat, sleep, play or attend school).

RESULTS

On day 1, children using oxycodone were more likely to report any AE (χ² ₁=13.5, p<0.001), nausea (χ² ₁=17.0, p<0.001), vomiting (χ² ₁=11.2, p<0.001), drowsiness (χ² ₁=13.7,p<0.001), constipation (χ² ₁=8.9, p=0.003) and dizziness (χ² ₁=19.1, p<0.001), compared with those using ibuprofen. Children receiving oxycodone reported greater severity of abdominal pain (oxycodone: mean 5.4 SD 3.1; ibuprofen mean 2.5 SD 1.4, F¹ ₁₃=6.5, p=0.02) on day 1 and worse intensity of constipation (oxycodone: mean 4.9 SD 2.1; ibuprofen mean 3.2 SD 2.2, F¹ ₃₃=4.5, p=0.04) over all 3 days. Use of oxycodone was associated with an increased odds of experiencing an AE on day 1 (OR=1.31 (95% CI 1.13 to 1.52)). Higher pain scores (OR=1.50 (95% CI 1.12 to 2.01)), lower extremity fracture (OR=1.25 (95% CI 1.07 to 1.47)) and undergoing ED sedation (OR=1.16 (95% CI 1.01 to 1.34)) were associated with missing school. Higher pain scores (OR=1.50 (95% CI 1.14 to 1.97)) and lower extremity fractures (OR=1.23 (95% CI 1.07 to 1.43)) were also associated with less play.

CONCLUSIONS

Oxycodone is associated with more frequent AEs overall, higher intensity gastrointestinal AEs and greater functional limitations compared with ibuprofen. Lower extremity fractures cause more functional limitations than upper extremity fractures. Clinicians should consider these differences when providing fracture pain care for children.

Dental Students’ Knowledge, Confidence, Ability, and Self-Reported Difficulties in Periodontal Education: A Mixed Method Pilot Study

Evidence on periodontal education areas in which students have difficulties and their factors are limited. In this study, third- and fourth-year dental students’ knowledge was assessed as well as their confidence and ability in five periodontal educational areas using a mixed-method approach. A survey was used to collect data related to history-taking, medical examination, diagnosis, treatment planning, and follow-up. Student answers were compared to the consensual answers of an expert panel using the cosine-similarity index (CSI). Descriptive statistics assessed confidence and ability for diagnosis. Semi-structured individual interviews were used to collect data on reported reasons for difficulties in periodontal education. A content analysis was employed to analyze the interview data. Eighteen third- and fourth-year dental students completed the survey and eleven were interviewed. Students’ knowledge was adequate regarding diagnosis and treatment planning. Third-year students’ median CSI were 0.93 and 0.89, respectively. Fourth-year students’ median CSI were 0.9 and 0.93, respectively. Students felt confident in history-taking and examination but lacked confidence and ability in diagnosis and treatment planning. Reported reasons for difficulties in periodontal education were linked to both preclinical and clinical pedagogical issues. Further improvements in preclinical and clinical periodontal education are needed to address students’ lack of knowledge, confidence, and skills in key periodontal areas.

ICD-11 Guidelines for Mental and Behavioral Disorders of Children and Adolescents: Reliability and Clinical Utility

OBJECTIVE

ICD-11 clinical guidelines for mental and behavioral disorders must be tested in clinical settings to guarantee their usefulness worldwide. The purpose of this study was to evaluate interrater reliability and clinical utility of the ICD-11 guidelines for children and adolescents in assessing and diagnosing mood, anxiety, and fear-related disorders; attention-deficit hyperactivity disorder (ADHD); and disruptive behavioral disorder (DBD).

METHODS

Children and adolescents ages 6-17 from two specialized settings in Mexico City were interviewed. Each was interviewed by a pair of psychiatrists (interviewer and observer), who independently codified established diagnoses and evaluated the clinical utility of the guidelines with each participant. Kappa values were calculated to determine the level of general diagnostic correlation between the two clinicians.

RESULTS

A total of 25 psychiatrists evaluated 52 children and adolescents. Kappa values between clinicians ranged from 0.46 to 0.53 for mood, anxiety, and fear-related disorders and for ADHD; the kappa value was 0.81 for DBD guidelines. Over 80% of psychiatrists reported that the guidelines, qualifiers, and descriptions of developmental presentations were quite useful.

CONCLUSIONS

ICD-11 guidelines for mental and behavioral disorders of children and adolescents demonstrated mostly moderate interrater reliability and strong interrater reliability in the case of DBD. A large proportion of clinicians regarded the guidelines as quite useful clinical tools.

Comparison of the effects of target-controlled infusion-remifentanil/midazolam and manual fentanyl/midazolam administration on patient parameters in dental procedures

Background

Moderate sedation is an integral part of dental care delivery. Target-controlled infusion (TCI) has the potential to improve patient safety and outcome. We compared the effects of using TCI to administer remifentanil/manual bolus midazolam with manual bolus fentanyl/midazolam administration on patient safety parameters, drug administration times, and patient recovery times.

Methods

In this retrospective chart review, records of patients who underwent moderate intravenous sedation over 12 months in a private dental clinic were assessed. Patient indicators (pre-, intra-, and post-procedure noninvasive systolic and diastolic blood pressure, respiration, and heart rate) were compared using independent t-test analysis. Patient recovery time, procedure length, and midazolam dosage required were also compared between the two groups.

Results

Eighty-five patient charts were included in the final analysis: 47 received TCI-remifentanil/midazolam sedation, and 38 received manual fentanyl/midazolam sedation. Among the physiological parameters, diastolic blood pressure showed slightly higher changes in the fentanyl group (P = 0.049), respiratory rate changes showed higher changes in the fentanyl group (P = 0.032), and the average EtCO₂ was slightly higher in the remifentanil group (P = 0.041). There was no significant difference in the minimum SpO₂ levels and average procedure length between the fentanyl and remifentanil TCI pump groups (P > 0.05). However, a significant difference was observed in the time required for discharge from the chair (P = 0.048), indicating that patients who received remifentanil required less time for discharge from the chair than those who received fentanyl. The dosage of midazolam used in the fentanyl group was 0.487 mg more than that in the remifentanil group; however, the difference was not significant (P > 0.05).

Conclusion

The combination of TCI administered remifentanil combined with manual administered midazolam has the potential to shorten the recovery time and reduce respiration rate changes when compared to manual administration of fentanyl/midazolam. This is possibly due to either the lower midazolam dosage required with TCI remifentanil administration or achieving a stable, steady-state low dose remifentanil concentration for the duration of the procedure.

Evaluating Classification Consistency of Oral Lesion Images for Use in an Image Classification Teaching Tool

A web-based image classification tool (DiLearn) was developed to facilitate active learning in the oral health profession. Students engage with oral lesion images using swipe gestures to classify each image into pre-determined categories (e.g., left for refer and right for no intervention). To assemble the training modules and to provide feedback to students, DiLearn requires each oral lesion image to be classified, with various features displayed in the image. The collection of accurate meta-information is a crucial step for enabling the self-directed active learning approach taken in DiLearn. The purpose of this study is to evaluate the classification consistency of features in oral lesion images by experts and students for use in the learning tool. Twenty oral lesion images from DiLearn's image bank were classified by three oral lesion experts and two senior dental hygiene students using the same rubric containing eight features. Classification agreement among and between raters were evaluated using Fleiss' and Cohen's Kappa. Classification agreement among the three experts ranged from identical (Fleiss' Kappa = 1) for "clinical action", to slight agreement for "border regularity" (Fleiss' Kappa = 0.136), with the majority of categories having fair to moderate agreement (Fleiss' Kappa = 0.332-0.545). Inclusion of the two student raters with the experts yielded fair to moderate overall classification agreement (Fleiss' Kappa = 0.224-0.554), with the exception of "morphology". The feature of clinical action could be accurately classified, while other anatomical features indirectly related to diagnosis had a lower classification consistency. The findings suggest that one oral lesion expert or two student raters can provide fairly consistent meta-information for selected categories of features implicated in the creation of image classification tasks in DiLearn.

Effect of Detailed OSCE Score Reporting on Learning and Anxiety in Medical School

INTRODUCTION

There is growing literature on increasing feedback from Objective Structured Clinical Examinations (OSCEs) and one approach is a score report. The purpose of this study was to implement and evaluate a score report for a second and fourth-year medical school OSCE.

METHODS

We developed an electronic OSCE score report that displayed comments and performance by domain within and across stations (checklist items and rating scales were tagged to each domain). Our initial pilot released the score report after pass/fail decisions but subsequent iterations released the score report the same day as the exam. Our evaluation approach included both student surveys and focus groups.

RESULTS

Students felt the OSCE score report was accurate, identified strengths and weaknesses, and would likely cause them to take future action, with second-year students more likely to act on the report than fourth year students. The thematic analysis revealed barriers and enablers to utilizing feedback as well as the power of the score report to reduce anxiety.

CONCLUSIONS

Our OSCE score report was simple to develop and implement the same day as an OSCE with an overall positive response from students with respect to accuracy and ability to use the information for future learning.

Survivorship of wild caught Mepraia spinolai nymphs: The effect of seasonality and Trypanosoma cruzi infection after feeding and fasting in the laboratory

Chagas disease is caused by Trypanosoma cruzi. Vector survival is an important variable affecting vectorial capacity to determine parasite transmission risk. The aims of this study are to evaluate vector survival under fasting/starvation conditions of wild-caught Mepraia spinolai after feeding and fasting, the pathogenicity of T. cruzi infection, the parasite burden and seasonal variation in parasite discrete typing units (DTU). The survivorship of M. spinolai nymphs after two continuous artificial feedings was evaluated, assessing their infection with microscopic observation of fecal samples and PCR. Later, insects were fasted/starved until death. We performed qPCR analyses of parasite load in the fecal samples and dead specimens. T. cruzi genotyping was performed using conventional PCR amplicons and hybridization tests. Infection rate was higher in M. spinolai nymphs in summer and spring than in fall. Parasite burden varied from 3 to 250,000 parasites/drop. Survival rate for starved nymph stage II was lower in insects collected in the spring compared to summer and fall. TcII was the most frequent DTU. Mainly metacyclic trypomastigotes were excreted. We conclude that M. spinolai infection rate in nymphs varies among seasons, suggesting higher transmission risk in warmer seasons. However, nymphs stage II collected in spring are more sensitive to starvation compared to other seasons. TcII in single or mixed infection does not seem relevant to determine vector pathogenicity. These results of vector survivorship after fasting/starvation are important to determine the competence of M. spinolai as a vector of T. cruzi, since they excrete metacyclic trypomastigotes and the parasitism with T. cruzi seems to be poorly pathogenic to the vector under a severe fasting/starvation condition.

Comparison of clinical and cognitive characteristics of a Mexican adult clinical population with and without ADHD

Introduction. Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting approximately 5% of the world population, with symptoms that may persist into adulthood. Despite the findings on the clinical course of this disorder, information regarding comorbidity patterns, psychosocial and executive functioning in adult life in those with and without ADHD in Latin American samples is scarce. Objective. The aim of this study is to compare the comorbidity pattern, psychosocial, and executive functioning of adults with and without ADHD from a clinical sample. Method. One hundred and fifty-one patients between 20 and 45 years, with screened positively on ASRS-V1.1, were invited to continue an evaluation process as part of clinical research program (PROMETEO): 1) K-SADS-PL Mx interview, 2) MINI-Plus interview, ASRS-V1-1 18 item version, BRIEF self-reported questionnaire, SCQA-ADHD, and 3) Individual case review by clinical expert in ADHD. Results. Individuals in the ADHD group had a higher average of comorbid disorders (2.5 SD 1.1 vs. 1.3 SD 1.0 respectively, F = .439; t = -6.621; df = 149; p < .001), more likelihood of procrastinating (OR = 6.5; 95% CI[2.6, 16.2]; z = 4.0) and were more likely to present difficulties in both the behavior regulation index (OR = 104.9; 95% CI[31.8, 345.7]; z = 7.65) and the metacognitive index (OR = 94.79; 95% CI[29.10, 308.76]; z = 7.56) compared to the non-ADHD group, regardless of gender. Discussion and conclusions. Our results indicate that the ADHD adult group presented with more comorbidity, and worse psychosocial and executive functioning than non-ADHD adults.

Validity and reliability of the kiddie schedule for affective disorders and schizophrenia present and lifetime version DSM-5 (K-SADS-PL-5) Spanish version

BACKGROUND

There are various language adaptations of the Schedule for Affective Disorders and Schizophrenia for School Age Children Present and Lifetime Version (K-SADS-PL). In order to comply with the changes in DSM classification, the Spanish edition of the interview was in need of update and evaluation.

METHODS

K-SADS-PL was adapted to correspond to DSM-5 categories. All clinicians received training, and a 90% agreement was reached. Patients and their parents or guardians were interviewed and videotaped, and the videos were exchanged between raters. Factor analysis was performed and inter-rater reliability was calculated only in the case of diagnoses in which there were more than five patients.

RESULTS

A total of 74 subjects were included. The Factor Analysis yielded six factors (Depressive, Stress Hyperarousal, Disruptive Behavioral, Irritable Explosive, Obsessive Repetitive and Encopresis), representing 72% of the variance. Kappa values for inter-rater agreement were larger than 0.7 for over half of the disorders.

CONCLUSIONS

The factor structure of diagnoses, made with the instrument was found to correspond to the DSM-5 disorder organization. The instrument showed good construct validity and inter-rater reliability, which makes it a useful tool for clinical research studies in children and adolescents.

Construct validity and parent-child agreement of the six new or modified disorders included in the Spanish version of the Kiddie Schedule for Affective Disorders and Schizophrenia present and Lifetime Version DSM-5 (K-SADS-PL-5)

Changes to the Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5) incorporate the inclusion or modification of six disorders: Autism Spectrum Disorder, Social Anxiety Disorder, Intermittent Explosive Disorder, Disruptive Mood Dysregulation Disorder, Avoidant/Restrictive Food Intake Disorder and Binge Eating Disorder. The objectives of this study were to assess the construct validity and parent-child agreement of these six disorders in the Spanish language Schedule for Affective Disorders and Schizophrenia for School Age Children Present and Lifetime Version (K-SADS-PL-5) in a clinical population of children and adolescents from Latin America. The Spanish version of the K-SADS-PL was modified to integrate changes made to the DSM-5. Clinicians received training in the K-SADS-PL-5 and 90% agreement between raters was obtained. A total of 80 patients were recruited in four different countries in Latin America. All items from each of the six disorders were included in a factor analysis. Parent-child agreement was calculated for every item of the six disorders, including the effect of sex and age. The factor analysis revealed 6 factors separately grouping the items defining each of the new or modified disorders, with Eigenvalues greater than 2. Very good parent-child agreements (r>0.8) were found for the large majority of the items (93%), even when considering the sex or age of the patient. This independent grouping of disorders suggests that the manner in which the disorders were included into the K-SADS-PL-5 reflects robustly the DSM-5 constructs and displayed a significant inter-informant reliability. These findings support the use of K-SADS-PL-5 as a clinical and research tool to evaluate these new or modified diagnoses.

Trypanosoma cruzi over the ocean: Insular zones of Chile with presence of infected vector Mepraia species

Chagas disease is one of the main zoonosis mediated by vectors in America. The etiologic agent Trypanosoma cruzi infects different mammals and is transmitted principally by the subfamily Triatominae. Mepraia is a genus endemic to Chile, responsible for transmitting T. cruzi in the sylvatic cycle. Mepraia includes three species: M. gajardoi and M. parapatrica inhabit coastal areas, while M. spinolai inhabits coastal and interior valleys. Previous studies reported the occurrence of Mepraia in Pan de Azucar Island, currently classified as M. parapatrica, but T. cruzi has not been reported in these insects. It is suggested that this could be due to infrequent insect feeding on mammalian hosts. In order to detect T. cruzi in insects from coastal islands, specimens from Pan de Azucar and Santa Maria Islands were examined. A region of kDNA of T. cruzi was amplified by PCR and hybridization assays were performed for T. cruzi genotyping of insect feces. The presence of infected insect and mixed T. cruzi infections was demonstrated. This is the first report of infected Triatominae in coastal islands in Chile. We discuss T. cruzi detection in insular zones, and the presumptive reservoirs that may participate in maintaining its transmission cycle in this habitat. Mixed and unidentified infections suggest that there are complex and unknown reservoir interactions in these habitats.

Minicircle classes heterogeneity within the TcIII and TcIV discrete typing units of Trypanosoma cruzi

The taxon Trypanosoma cruzi, causative agent of Chagas disease, is composed of several discrete typing units (DTUs) named TcI-TcVI, and Tcbat. The history of the taxon T. cruzi is known, even though several controversial aspects remain as the relationships between TcIII and TcIV. We analyzed cloned T. cruzi stocks pertaining to the seven DTUs by filter hybridization tests of PCR amplicons from minicircle variable regions and kinetoplast DNA probes. Minicircle DNA blots from the cloned stocks and filter hybridization with one TcI, one TcII, one TcV, one TcVI, three TcIII, one TcIV from North America and one TcIV kinetoplast DNA probes from South America revealed minicircle variable region cross-reaction in some T. cruzi DTUs probed. TcIII was heterogeneous in minicircle class composition, even though two TcIII probes revealed that a small fraction of minicircles cross-hybridized with the minicircles from the TcIII, TcV and TcVI DTUs. The minicircles of TcIV from North America cross-reacted only with TcIV from North America but not with TcIV stocks from Brazil and Bolivia. The results on minicircle cross-hybridizations are discussed in the context of RNA editing, mitochondrial function in T. cruzi DTUs.

[Prognostic implications of folliculo-stellate cells in pituitary adenomas: relationship with tumoral behavior]

INTRODUCTION

Despite progress in understanding its pathogenesis, there has not yet been found any independent predictive marker of aggressive behavior of pituitary adenomas, to facilitate the treatment and monitoring of patients.

AIM

To analyze the expression of folliculo-stellate cells by immunostaining with S-100 protein, in a series of patients with pituitary adenomas followed for at least seven years.

PATIENTS AND METHODS

A retrospective study of 51 patients diagnosed with a pituitary adenoma between 2006 and 2008 was performed, according to current criteria established by the World Health Organization. The S-100 expression in folliculo-stellate cells was immunohistochemically evaluated, correlating it with clinico-radiological and histopathological tumor parameters and post-operative progression/recurrence.

RESULTS

Of 51 tumors, 40 were classified as typical and 11 as atypical pituitary adenomas. Most typical pituitary adenomas showed positive folliculo-stellate cells for S-100 (mean: 3.93%); atypical had little/no cell S-100 positive (mean: 0.83%). There were no significant differences in the expression of S-100 with respect to age or sex of the patient, size, invasiveness or post-operative tumor recurrence.

CONCLUSIONS

In our study group, with the exception of non-functioning adenomas immunopositive for prolactin, with the lowest and highest average of all subtypes in both groups (typical 0.25% vs atypical 9.24%; p = 0.0028), the predictive factor of tumor aggressiveness for pituitary adenomas, is not represented by a low value of S-100 in folliculo-stellate cells, not allowing select patients for intensive post-operative treatment.

Trypanosoma cruzi diversity in infected dogs from areas of the north coast of Chile

As part of a multi-site research program on the eco-epidemiology and control of Chagas disease in northern Chile, we sought to identify the Trypanosoma cruzi discrete typing units (DTUs) infecting rural and peridomestic dogs, using direct methods without grown of the parasite in the laboratory and thus to assess the use of this species as a sentinel of the disease in well-defined endemic areas of T. cruzi in Chile. Infected dogs (35) from three villages were included in the study. The studied villages were Caleta Río Seco and Caleta San Marcos, both in the Tarapacá Region, and La Serena in the Coquimbo Region. These villages were selected based on previous evidence of Mepraia infection reports of the Chilean Ministry of Health. Amplicons from nested-PCR positive samples were used as targets to determine the infective T. cruzi DTUs circulating in blood using PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). Results of hybridization with dog samples from Caleta Rio Seco showed single infections in 2 out of 16 and mixed infections in 14 out of 16. TcVI was the most frequent DTU found in this area. A highlight is that for the first time the presence of TcIII is reported in this area. Samples from Caleta San Marcos showed single infections in 5 out of 9 and mixed infections in 4 out of 9. TcVI was the most frequent DTU found in this area. Samples from La Serena showed single infections in 5 out of 10 and mixed infections in 2 out of 10; we were unable to genotype the other 3 samples. Our results indicate that infection by T. cruzi DTUs in dogs is not homogeneously distributed but rather specific to each region of our country, as demonstrated by the differences in the T. cruzi DTU distribution in some localities.

Birth Control and Low-Income Mexican-American Women: The Impact of Three Values

Nineth-nine Mexican-American women who were identified as either high or low acculturated responded to questionnaires assessing the relationship between birth control attitudes, knowledge, and usage, and the values ascribed to motherhood, male dominance, and sexual expression. Using a multiple regression analysis, a significant positive relationship was found for both high and low acculturated women with respect to their attitudes toward birth control and the values ascribed to motherhood, male dominance, and sexual expression. Relative to birth control use, a significant positive relationship was found between this variable and the values ascribed to motherhood, male dominance, and sexual expression for the low but ntot the high acculturated women. Finallh, no significant relationship was found between birth control knowledge and the aforementioned values. It should be noted that the differences between the low and high acculturated women persisted even while holding their socioeconomic level constant.

Mid-infrared nonlinear optical response of Si-Ge waveguides with ultra-short optical pulses

We characterize the nonlinear optical response of low loss Si(0.6)Ge(0.4) / Si waveguides in the mid-infrared between 3.3 μm and 4 μm using femtosecond optical pulses. We estimate the three and four-photon absorption coefficients as well as the Kerr nonlinear refractive index from the experimental measurements. The effect of multiphoton absorption on the optical nonlinear Kerr response is evaluated and the nonlinear figure of merit estimated providing some guidelines for designing nonlinear optical devices in the mid-IR. Finally, we compare the impact of free-carrier absorption at mid-infrared wavelengths versus near-infrared wavelengths for these ultra-short pulses.

On the prediction of Hodgkin lymphoma treatment response

PURPOSE

The cure rate in Hodgkin lymphoma is high, but the response along with treatment is still unpredictable and highly variable among patients. Detecting those patients who do not respond to treatment at early stages could bring improvements in their treatment. This research tries to identify the main biological prognostic variables currently gathered at diagnosis and design a simple machine learning methodology to help physicians improve the treatment response assessment.

METHODS

We carried out a retrospective analysis of the response to treatment of a cohort of 263 Caucasians who were diagnosed with Hodgkin lymphoma in Asturias (Spain). For that purpose, we used a list of 35 clinical and biological variables that are currently measured at diagnosis before any treatment begins. To establish the list of most discriminatory prognostic variables for treatment response, we designed a machine learning approach based on two different feature selection methods (Fisher's ratio and maximum percentile distance) and backwards recursive feature elimination using a nearest-neighbor classifier (k-NN). The weights of the k-NN classifier were optimized using different terms of the confusion matrix (true- and false-positive rates) to minimize risk in the decisions.

RESULTS AND CONCLUSIONS

We found that the optimum strategy to predict treatment response in Hodgkin lymphoma consists in solving two different binary classification problems, discriminating first if the patient is in progressive disease; if not, then discerning among complete and partial remission. Serum ferritin turned to be the most discriminatory variable in predicting treatment response, followed by alanine aminotransferase and alkaline phosphatase. The importance of these prognostic variables suggests a close relationship between inflammation, iron overload, liver damage and the extension of the disease.

Nonlinear optical response of low loss silicon germanium waveguides in the mid-infrared

We have investigated the nonlinear optical response of low loss Si(0.6)Ge(0.4) / Si waveguides in the mid-infrared wavelength range from 3.25- 4.75μm using picosecond optical pulses. We observed and measured the three and four-photon absorption coefficients as well as the Kerr nonlinear refractive index. The dynamics of the spectral broadening suggests that, in addition to multiphoton absorption, the corresponding higher order nonlinear refractive phenomena also needs to be included when high optical pulse intensities are used at mid-infrared wavelengths in this material.

FT-IR and FT-Raman spectra of 6-chlorouracil: molecular structure, tautomerism and solid state simulation. A comparison between 5-chlorouracil and 6-chlorouracil

A Raman and IR study of the biomolecule 6-chlorouracil was carried out in the solid state. The unit cell found in the crystal was simulated as a tetramer form by density functional calculations. Specific scale factors and scaling equations deduced from uracil molecule were employed in the predicted wavenumbers of 6-chlorouracil. The scaled wavenumbers were used in the reassignment of the IR and Raman experimental bands. Good reproduction of the experimental wavenumbers is obtained and the % error is very small in the majority of cases. A comparison between the molecular structure and charge distribution of 6-chlorouracil and 5-chlorouracil molecules was presented. The effect of the hydration with the PCM model in the molecular structure and charges was discussed. The optimum tautomers of 6-chlorouracil were optimized and analyzed. Six of them were related to those of uracil molecule. The effect of the halogen substitution in the sixth position of the pyrimidine ring in the stability of the different tautomers was evaluated. HOMO and LUMO orbital energy analysis were carried out.

Common variant in VEGFA and response to anti-VEGF therapy for neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of visual impairment in aging populations in industrialized countries. Here we investigated whether the genotype of vascular endothelial growth factor A (VEGFA) gene is associated with response to anti-VEGF therapy. 223 eyes with neovascular AMD were treated with intravitreal anti-VEGF therapy. Responders were defined as patients who had an improvement in best corrected visual acuity (BCVA) of at least 5 letters or one line on the EDTRS visual acuity chart along with resolution of intraretinal or subretinal fluid over 12 months. Patients who did not meet the definition of responders were classified as poor-responders. The vision of responders (n = 148) improved while the vision of poor-responders (n = 75) worsened (P<0.001). Responders on average had a decrease in central foveal thickness (CFT), while poor-responders had an increase in CFT (P <0.001). Compared with the responder group, the poor-responder group had a higher frequency of the risk (T) allele (Allelic P = 0.019) and TT genotype (P = 0.002 under a recessive model) for the VEGFA-rs943080 polymorphism. VEGFA expression was 1.8-fold higher in cells with the VEGFA rs943080 TT genotype than in cells with the VEGFA rs943080 CC genotype (P = 0.012). Age, gender, smoking, diabetes mellitus, and hypertension did not play a significant role in treatment response, but BMI was found to be significantly different between responders and poorresponders (P = 0.033). In conclusion, we demonstrated a potential pharmacogenetic relationship between the VEGFA gene and treatment response to anti-VEGF therapy.The studies are registered at ClinicalTrials.gov under the identifiers NCT00474695 (http://clinicaltrials. gov/ct2/show/NCT00474695) and NCT01464723 (http://clinicaltrials.gov/ct2/show/NCT01464723).

Congenital co-infection with different Trypanosoma cruzi lineages

Variability of mixed Trypanosoma cruzi congenital infection in Chile in twenty one congenital samples of Chagas disease is reported. Recognition of infecting strains was performed by minicircle hybridization tests. Seven newborns with double infection were found. Trypanosoma cruzi TcII and TcV lineages were the most frequent in single and mixed infections. With these results we pretend to understand the epidemiological significance of the T. cruzi lineages for which the placenta does not seem to represent an actual barrier in congenital infections.

Simulation of a tetramer form of 5-chlorouracil: the vibrational spectra and molecular structure in the isolated and in the solid state by using DFT calculations

A Raman and FT-IR study of the biomolecule 5-chlorouracil in the solid state was carried out. The unit cell found in the crystal was simulated as a tetramer form by density functional calculations. They were performed to clarify the assignments of the experimentally observed bands in the spectra. Calculations in the monomer form and comparisons with the experimental data in Ar matrix were also carried out. The error in the calculated frequencies was analyzed and reduced by using scaling equations and scaling factors deduced from the uracil molecule. The calculations with the B3LYP method and with the 6-31G(d,p) and 6-311+G(2d,p) basis set, appear in general to be useful, when combining with a scaling equation procedure or with the specific scale factors, for interpretation of the general features of the IR and Raman spectra. The scaled values were used in the reassignment of the IR and Raman experimental bands. Comparison of the results with those determined in uracil and 5-halogenated derivatives were performed. The substitution at 5-position of the uracil ring by a chlorine atom has a little effect on the geometric parameters.

Caracterização bromatológica e agronômica de genótipos de milho para produção de silagem

O objetivo deste trabalho foi avaliar as características bromatológicas e agronômicas dos genótipos de milho para a produção de silagem dos cultivares do Ensaio Centro Superprecoce da Rede Nacional de Genótipos de Milho, bem como avaliar se a base genética (híbridos simples, duplos, tripos, intervarietais e variedades cultivadas) ou a dureza dos grãos (duro, semiduro e dentado mole) alteram a indicação de cultivares de milho para silagem. O experimento foi realizado na área experimental da Universidade Tecnológica Federal do Paraná (campus Dois Vizinhos). Os trinta e dois genótipos avaliados foram colhidos quando os grãos encontravam-se no estádio pastoso a farináceo, ensilados em microssilos de PVC e desensilados após 53 dias. Avaliou-se a relação entre as bases genéticas, a dureza do grão e as características individuais dos genótipos quanto à aptidão para a produção de silagem. Não se verificaram diferenças significativas entre os contrastes formados entre as bases genéticas, bem como a dureza dos grãos, para os caracteres estudados. Porém, foi possível identificar genótipos superiores para a produção de silagem pela produção de matéria seca pelos genótipos AS 1555 YG, AS 1572 YG, 30A37, 30A77, 20A78, Dx 908, Dx 603, 2A550, 2B433, AL2007A, Embrapa 1F640, PRE 22T10, PREXT0109, PRE 22D11, DKB330 YG (Test).