Highlights of the 1st Ecuadorian-Venezuelan Symposium of Young Researchers in Bioinformatics (1SEVJIB).

The COVID-19 pandemic profoundly changed how scientific conferences are organized, fostering virtual meetings. These online events have allowed students and researchers to overcome geographical, administrative and economic barriers to attend and organize high-quality international symposiums. Moreover, these virtual conferences have contributed to the creation of inclusive activities that strengthen scientific communities. Here, we summarize the main activities and learnings from the 1st Ecuadorian-Venezuelan Symposium of Young Bioinformatics Researchers (1SEVJIB), organized by the Ecuadorian and Venezuelan ISCB-SC Regional Student Groups (RSGs). This symposium aimed to provide an opportunity for undergraduate and postgraduate students from Ecuador, Venezuela, and other Latin American countries to share their Bioinformatics research. The 1SEVJIB was the first bi-national conference organized by two RSGs from Latin America (LatAm). This symposium was a two-day virtual meeting with five activities: 1) oral student presentations, 2) poster session, 3) keynote lectures, 4) workshop, and 5) round table. This conference promoted the scientific exchange and cooperation networks between young Bioinformatics researchers and students from Ecuador, Venezuela, and LatAm, giving them opportunities to boost their scientific careers.

Facial paralysis associated with glomus jugulare tumors.

OBJECTIVE: To review the intraoperative findings and facial nerve management in nine patients who presented with facial paralysis associated with glomus jugulare tumors. STUDY DESIGN: A retrospective analysis of patient medical records. SETTING: Tertiary care academic medical center. PATIENTS: All patients who presented with facial paralysis and a glomus jugulare tumor who underwent surgical resection of their tumors at our institution. INTERVENTION: A postauricular infratemporal fossa approach for tumor removal and greater auricular interposition neural repair. MAIN OUTCOME MEASURE: Intraoperative facial nerve findings and long-term facial recovery. RESULTS: One hundred two patients underwent a postauricular infratemporal approach for resection of glomus jugulare tumor from July 1988 through July 2005. Nine of these patients presented with ipsilateral facial paralysis. The medial surface of the vertical segment was invaded by tumor in all nine cases. Facial recovery at 2 years was House-Brackmann Grade III in eight patients and Grade IV in one individual. Facial recovery did not significantly change after 2 years (mean follow-up of 7.4 years). DISCUSSION: Facial nerve invasion of the vertical segment occurred in 9 (9%) of 101 patients in our series. Facial nerve resection with interposition grafting resulted in House-Brackmann Grade III in eight (89%) of nine patients. Facial nerve dissection and preservation was not possible when preoperative facial paralysis was evident.

DITPA restores the repolarizing potassium currents Itof and Iss in cardiac ventricular myocytes of diabetic rats.

Diabetes Mellitus (DM) can produce an increase in the cardiac action potential duration and QT interval that can be associated with sudden death. These cardiac effects are due to a region-specific decrease in repolarizing outward K(+) currents. Some authors have suggested that the proarrhythmic effects of diabetes can be due to diabetes-induced hypothyroidism. Thus, we have examined the effect of the thyroid hormone analog diiodothyropropionic acid (DITPA) on calcium-independent outward potassium currents in ventricular myocytes from diabetic rats. Sustained (I(ss)) and fast transient outward (I(tof)) K(+) currents were recorded using the whole-cell configuration of the patch-clamp technique. Myocytes were enzymatically isolated from the free wall of the right ventricle, and the epicardial and endocardial layers of the left ventricle of healthy, diabetic and DITPA-treated diabetic rats. Circulating thyroid hormones were measured by electrochemiluminescence. DITPA-treatment of diabetic rats restored I(tof) and I(ss) current densities in cardiac myocytes from the three regions studied, but did not alter current densities in myocytes of control rats. T(3) and T(4) levels were reduced by diabetes, and DITPA-treatment increased circulating T(3) levels. T(3)-treatment of diabetic rats also restored current densities to control values. However, direct incubation of diabetic myocytes with DITPA did not restore current densities. In summary, DITPA-treatment of diabetic rats restored the potassium current (I(tof) and I(ss)) densities in myocytes from all ventricular regions.

Knock-in mouse model for resistance to thyroid hormone (RTH): an RTH mutation in the thyroid hormone receptor beta gene disrupts cochlear morphogenesis.

Thyroid hormone and the beta isoform of its receptor, Trb, are essential for normal development of the mammalian auditory system. We have analyzed auditory system function and structure in a mouse strain with a targeted Thrb mutation, Thrb(PV), which leads to the loss of binding of thyroid hormone (T3) to the Trb protein. Heterozygosity for the orthologous human THRB(PV) mutation and other similar mutations in human THRB cause resistance to thyroid hormone (RTH), which is occasionally associated with mild sensorineural hearing impairment. Auditory brainstem response analysis of heterozygous Thrb(PV)/+ mice demonstrates that they develop normal hearing. In contrast, Thrb(PV)/Thrb(PV) mice have severe hearing impairment that is already present at 3 weeks of age. This hearing loss is associated with disruption of postnatal morphogenesis of the tectorial membrane and organ of Corti. Comparison with the previously described phenotype of a Thrb -/- knockout strain suggests that Thrb(PV) disrupts the function of other genes that are critical for development and/or maintenance of these structures.

Increased wave latency in auditory brainstem response to anemia in newborn and adult sheep.

The objective of the present study was to determine whether phlebotomy-induced anemia in newborn lambs and adult sheep results in prolonged auditory brainstem response (ABR) wave latencies, and if found, whether developmental differences exist between the two groups. Among newborn lambs, hemoglobin (Hb) levels were reduced from 100-120 to 30-50 g/l over a 3-day period. Over the next 2 days, serial red blood cell transfusions were administered to restore Hb to pre-phlebotomy levels. In adult sheep, comparable levels of phlebotomy-induced anemia were achieved within a 24-hour period, after which Hb levels returned to pre-phlebotomy levels. During the induction of anemia and its reversal, a significant (p < 0.05) increase in ABR latency followed by a return to pre-anemia ABR latencies that was most prominent in the peripheral auditory pathway was observed in both newborn and adult sheep as Hb levels fell below 50 g/l (p < 0.05). There was no difference between adults and newborns in ABR latency relative to the Hb level at which ABR wave latencies increased. We speculate that ABR wave latency prolongation might serve as an indicator of the need for red blood cell transfusion.

Comparison of neonatal hearing screening devices

Incidence studies estimate that 1-3 per 1000 full term normal neonates and 2-4 of high-risk newborns per 100 have severe bilateral hearing loss. In response, universal hearing screening has been proposed; however, choosing the most appropriate technology continues to be an obstacle. The purpose of the current preliminary study was to compare test results from thirty-two full-term newborns using three types of screening devices, Natus Algo 2 AABR, Otodynamics EchoCheck TEE, and Biologic AuDx DPE. Results indicate that the Natus had the highest pass percentage rate for the right and left ears at 97 and 91 respectively, while the other two devices had pass percentage rates between 31 and 56. Test duration time for the Natus was 22.5 minutes compared with 5.8-6.4 minutes for the other devices. Despite the longer duration time, our findings favor using the Natus, given its accurate representation of incidence data.