Assessment of ovarian vascularization in the polycystic ovary by three-dimensional power Doppler ultrasonography

Objective. To assess whether there are differences in ovarian echogenicity and vascularization as assessed by three-dimensional power Doppler angiography (3D-PDA) between women with polycystic ovaries (PCO) and women with normal ovaries (NO).

Methods. Eighty-three women were classified into two groups according to the 2003 Rotterdam consensus criteria. The NO group comprised women (n = 45) with regular menstrual cycles and proven fertility, whereas the PCO group comprised women (n = 38) with oligo-anovulation, clinical and/or biochemical features of hyperandrogenism, and polycystic ovary morphology at two-dimensional ultrasound. All women were evaluated by means of 3D-PDA. The parameters studied in both groups were follicle number per ovary (FNPO), ovarian volume (OV), mean gray value (MG) and three vascular indices: vascularization index (VI), flow index (FI) and vascularization flow index (VFI).

Results. The PCO group showed a higher mean OV as well as FNPO. No differences in MG, VI, FI and VFI were found between the groups.

Conclusions. 3D-PDA indices are not useful for discriminating between normal and polycystic ovaries.     

【In Press】Clinical outcomes of patterned laser trabeculoplasty as adjuvant therapy in open-angle glaucoma and ocular hypertension

AIM: To assess the efficacy and safety of patterned laser trabeculoplasty (PLT) as an adjunctive treatment in open-angle glaucoma (OAG) or ocular hypertension (OHT) patients who were under antiglaucoma medical treatment. METHODS: This study was a retrospective review of primary or secondary OAG patients and OHT patients with medically uncontrolled (≥18 mm Hg) intraocular pressure (IOP) who underwent 360º PLT from June 2016 to August 2016. Follow-up visits at week 1, and 1, 3 and 6mo were performed. IOP, best corrected visual acuity (BCVA), complications and eye drop glaucoma medication were recorded at each follow-up visit. Success was defined as IOP reduction ≥20% from baseline. RESULTS: Forty one eyes of 25 patients were included in this study. Pre-treatment mean IOP was 20.2±1.6 mm Hg. After PLT, IOP was 19.3±5.2, 16.1±2.7, 17.1±3.7 and 16.3±3.5 mm Hg, at 1wk, 1, 3 and 6mo, respectively. IOP reduction from baseline was statistically significant from the first month, remaining stable at 6mo (P<0.001). PLT success at 6mo of follow-up was 48.7%. The number of glaucoma medication per eye (P=0.10) and the mean BCVA both remained constant (P=0.37). Complications included transient IOP spikes in 4 eyes (9.7%) and peripheral anterior synechiae in 7 eyes (17.1%). CONCLUSION: PLT is an effective and safe method for the management of patients with OHT or OAG as an adjunctive therapy. Additional larger studies should be designed to verify the long-term stability of IOP reduction with this laser technology.     

Phase I/II study of gefitinib and capecitabine in patients with colorectal cancer

Objective The objectives of this phase I/II study were to determine the maximum tolerated dose (MTD), characterise the principal toxicities in the phase I part and assess the efficacy in the phase II part of gefitinib, an oral selective inhibitor of the epidermal growth factor receptor, in combination with capecitabine in patients with advanced colorectal cancer (CRC). Methods and patients Patients with advanced CRC were treated with gefitinib administered daily for 21 days and capecitabine administered twice daily for 14 days of a 21-day cycle. The dose levels of gefitinib (mg) and capecitabine (mg/m² bid) assessed were 250/1000 and 250/ 1250. An expanded cohort was enrolled at the MTD to better characterise toxicity and efficacy. A total of 32 previously treated patients were accrued. In the phase I part 10 subjects were treated, with one dose-limiting toxicity. Overall 26 patients were treated at the MTD of the combination, which was gefitinib 250 mg/day and capecitabine 1250 mg/m² twice daily. Results The most frequent treatment-related adverse events included asthenia, diarrhoea, nausea, rash and anorexia. The incidence profile was very similar in phases I and II. No objective responses were documented but 53% of the patients achieved stable disease as best response to therapy. Conclusions Capecitabine 1250 mg/m² twice daily 14 of 21 days and gefitinib at 250 mg/day can be safely administered in combination. The combination is relatively well tolerated. There were no objective responses, although an interesting stabilisation rate was documented, in previously treated advanced CRC patients.     

Mechanism of voltage sensing in Ca2+- and voltage-activated K+ (BK) channels

In neurosecretion, allosteric communication between voltage sensors and Ca²⁺ binding in BK channels is crucially involved in damping excitatory stimuli. Nevertheless, the voltage-sensing mechanism of BK channels is still under debate. Here, based on gating current measurements, we demonstrate that two arginines in the transmembrane segment S4 (R210 and R213) function as the BK gating charges. Significantly, the energy landscape of the gating particles is electrostatically tuned by a network of salt bridges contained in the voltage sensor domain (VSD). Molecular dynamics simulations and proton transport experiments in the hyperpolarization-activated R210H mutant suggest that the electric field drops off within a narrow septum whose boundaries are defined by the gating charges. Unlike Kv channels, the charge movement in BK appears to be limited to a small displacement of the guanidinium moieties of R210 and R213, without significant movement of the S4.

Excitable tissues accomplish their signaling functions thanks in part to the interplay of several voltage-sensitive ion channels (1–6). Hence, to understand these processes, it is crucial to establish how voltage-sensitive ion channels sense changes in the electric field across the membrane, an issue that has been a matter of extensive study and intense debate for decades. The most widely accepted mechanism proposes the existence of voltage-sensor domains (VSDs), modules that undergo two or more discrete conformational states in response to changes in the membrane voltage. The simplest model considers two states: active (A), which promotes pore opening, and resting (R), which promotes channel closing. To accomplish its function, VSDs contain voltage-sensitive particles, which move in response to changes in the electric field. This movement triggers the interconversion between the two discrete conformational states. These voltage-sensing particles are typically the guanidine groups of arginine residues within the S4 transmembrane segment, which undergo a combination of rotational, translational, and tilting movement in response to changes in membrane voltage (7–14).The large-conductance Ca²⁺- and voltage-activated K⁺ (BK) channels have a wide distribution in mammalian tissues (15–18), where they participate in a diversity of physiological processes. Their malfunction is often related to diverse pathological conditions (19, 20). BK channel open probability is independently regulated by membrane depolarization and intracellular Ca²⁺ concentration (21, 22), each stimulus being detected by specialized modules. Like other voltage-sensitive K⁺ (Kv) channels, BK is an homotetramer in which each of its α subunits consists of a pore domain (PD; S5-S6 transmembrane segments), a voltage-sensing domain (VSD; S1–S4 transmembrane segments) containing a positively charged S4, and a cytosolic C-terminal regulatory domain, which contains the Ca²⁺-binding sites (23, 24). Also, like some members of other K⁺ channel families (25, 26), the VSD and PD of BK are non–domain swapped (23, 24). BK channels display some distinctive structural and functional features: Despite sharing the selectivity filter sequence with Kv channels, BK unitary conductance and selectivity are exquisitely high (27–30). The BK α subunit has an additional transmembrane segment S0 [therefore, its N terminus faces the extracellular medium (31)], and the voltage sensitivity in BK channels is significantly lower than that of Kv channels, presumably because of their lower number of gating charges (32).Although thoroughly studied, research into BK VSD and its voltage dependence has faced several technical obstacles. The relatively small gating charge per channel (32) and the large conductance of the BK pore makes isolating of the gating currents from the ionic currents a tough experimental challenge. In addition, because mutations of VSD residues can produce very large shifts in both the gating charge-voltage (Q(V)) and the conductance-voltage G(V)) relationships (33), it is necessary to use extreme voltages to accurately measure the voltage dependence of some mutants. Consequently, the identification of BK gating charges has been addressed by using indirect approaches (33, 34). The combination of electrophysiology measurements and kinetic modeling suggests a decentralized VSD in the BK channel, where four charged residues (D153 and R167 in S2, D186 in S3, and R213 in S4) act as voltage sensor particles (33). A recent report of the atomistic cryo-electron microscopy (cryo-EM) structures of the human BK channel and its homolog in Aplysia californica (AcSlo) revealed minor structural differences between the VSD in both the Ca²⁺-bound (open pore) and the Ca²⁺-unbound (closed pore) conformations (23, 24, 35). This result can be explained if the conformational changes of the BK VSD upon activation are small compared to those that occur during the activation of other channels, such as HCN channels (12–14).In this study, we identified voltage-sensing particles in the BK channel by using a direct functional approach, involving gating of current measurements and analysis of the Q(V) curves spanning 800 mV in the voltage axis. Systematic neutralization of the individual charged residues in the VSD (S1–S4) revealed that only the neutralization of two arginines in S4 (R210 and R213) changed the voltage dependence of the Q(V) curves. Neutralization of other VSD charges point to roles in tuning of the half-activation voltage of the VSD and its allosteric coupling with the PD. Molecular dynamics (MD) simulations based on the cryo-EM structures of the human BK channel (35) as templates suggested that R210 and R213 lie in a very narrow septum separating intra- and extracellular water-filled vestibules. This interpretation is consistent with the robust hyperpolarization-activated proton currents generated when R210 is mutated to the protonable amino acid histidine. Overall, our results point to a unique and distinctive mode of activation in BK: In contrast to Kv channels, where positive charges move one by one through a charge transfer center (absent in BK channels) that spans the entire electric field (36, 37), charge movement in BK channels is limited to the small displacement of R210 and R213, which itself constitutes a narrow septum where the electric field drops.     

Differential Effects of Three Nutritional Supplements on the Nutrient Intake of Pregnant Women Enrolled in a Conditional Cash Transfer Program in Mexico: A Cluster Randomized Trial

Supplementation in malnourished pregnant women should not displace natural healthy foods. Objective: To estimate the differential effects of three nutritional supplements on macro- and micronutrient intake of pregnant women beneficiaries of the conditional cash transfer program Prospera (CCT-POP). Methods: Prospective cluster randomized trial. Communities were randomly assigned to receive a fortified beverage (Beverage), micronutrient tablets (Tablets), or micronutrient powder (MNP). Pregnant women (at <25 weeks) were recruited. The food frequency questionnaire was applied at 25 and 37 weeks of pregnancy and at one and three months postpartum (mpp). Differential effects of the three supplements on the median change in nutrient intake from baseline to each follow-up stage were estimated. Results: Median change in protein intake from dietary and supplement sources were significantly lower for MNP and Tablets than for Beverages (baseline to 37 w: −7.80 ± 2.90 and −11.54 ± 3.00, respectively; baseline to 1 mpp: −7.34 ± 2.90 for MNP, p < 0.001). Compared to Beverages, median increases were higher for the MNP for vitamins C (31.2 ± 11.7, p < 0.01), E (1.67 ± 0.81, p < 0.05), and B12 (0.83 ± 0.27, p < 0.01) from baseline to 37 wk; from baseline to 1 mpp, there was a higher median increase in B12 (0.55 ± 0.25, p < 0.05) and folate (63.4 ± 24.3, p < 0.01); and from baseline to 3 mpp, a higher median increase in iron (2.38 ± 1.06, p < 0.05) and folate (94.4 ± 38.1, p < 0.05). Conclusions: Intake of micronutrients was higher for MNP and Tablets, likely due to food displacement among Beverage consumers. Although iron bioavailability and absorption inhibitors were not considered for the present analyses, the distribution of Tablets or MNP had several advantages in this context where micronutrient deficiency remains high among pregnant women, but macronutrient intake is generally adequate or even high.     

Evaluation of the multimorbidity network and its relationship with clinical phenotypes in chronic obstructive pulmonary disease: The GALAXIA study

BackgroundChronic obstructive pulmonary disease (COPD) is a complex and heterogeneous condition, in which taking into consideration clinical phenotypes and multimorbidity is relevant to disease management. Network analysis, a procedure designed to study complex systems, allows to represent connections between the distinct features found in COPD.MethodsNetwork analysis was applied to a cohort of patients with COPD in order to explore the degree of connectivity between different diseases, taking into account the presence of two phenotypic traits commonly used to categorize patients in clinical practice: chronic bronchitis (CB⁺/CB⁻) and the history of previous severe exacerbations (Ex⁺/Ex⁻). The strength of association between diseases was quantified using the correlation coefficient Phi (ɸ).ResultsA total of 1726 patients were included, and 91 possible links between 14 diseases were established. Although the four phenotypically defined groups presented a similar underlying comorbidity pattern, with special relevance for cardiovascular diseases and/or risk factors, classifying patients according to the presence or absence of CB implied differences between groups in network density (mean ɸ: 0.098 in the CB⁻ group and 0.050 in the CB⁺ group). In contrast, between‐group differences in network density were small and of questionable significance when classifying patients according to prior exacerbation history (mean ɸ: 0.082 among Ex⁻ subjects and 0.072 in the Ex⁺ group). The degree of connectivity of any given disease with the rest of the network also varied depending on the selected phenotypic trait. The classification of patients according to the CB⁻/CB⁺ groups revealed significant differences between groups in the degree of conectivity between comorbidities. On the other side, grouping the patients according to the Ex⁻/Ex⁺ trait did not disclose differences in connectivity between network nodes (diseases).ConclusionsThe multimorbidity network of a patient with COPD differs according to the underlying clinical characteristics, suggesting that the connections linking comorbidities between them vary for different phenotypes and that the clinical heterogeneity of COPD could influence the expression of latent multimorbidity. Network analysis has the potential to delve into the interactions between COPD clinical traits and comorbidities and is a promising tool to investigate possible specific biological pathways that modulate multimorbidity patterns.     

Differences in the causes of death of HIV-positive patients in a cohort study by data sources and coding algorithms

OBJECTIVES:: To compare causes of death (CoDs) from two independent sources: National Basic Death File (NBDF) and deaths reported to the Spanish HIV Research cohort [Cohort de adultos con infección por VIH de la Red de Investigación en SIDA CoRIS)] and compare the two coding algorithms: International Classification of Diseases, 10th revision (ICD-10) and revised version of Coding Causes of Death in HIV (revised CoDe). METHODS:: Between 2004 and 2008, CoDs were obtained from the cohort records (free text, multiple causes) and also from NBDF (ICD-10). CoDs from CoRIS were coded according to ICD-10 and revised CoDe by a panel. Deaths were compared by 13 disease groups: HIV/AIDS, liver diseases, malignancies, infections, cardiovascular, blood disorders, pulmonary, central nervous system, drug use, external, suicide, other causes and ill defined. RESULTS:: There were 160 deaths. Concordance for the 13 groups was observed in 111 (69%) cases for the two sources and in 115 (72%) cases for the two coding algorithms. According to revised CoDe, the commonest CoDs were HIV/AIDS (53%), non-AIDS malignancies (11%) and liver related (9%), these percentages were similar, 57, 10 and 8%, respectively, for NBDF (coded as ICD-10). When using ICD-10 to code deaths in CoRIS, wherein HIV infection was known in everyone, the proportion of non-AIDS malignancies was 13%, liver-related accounted for 3%, while HIV/AIDS reached 70% due to liver-related, infections and ill-defined causes being coded as HIV/AIDS. CONCLUSION:: There is substantial variation in CoDs in HIV-infected persons according to sources and algorithms. ICD-10 in patients known to be HIV-positive overestimates HIV/AIDS-related deaths at the expense of underestimating liver-related diseases, infections and ill defined causes. CoDe seems as the best option for cohort studies.