Relationship between the hemodynamic profile and resistant hypertension in pregnant patients with hypertensive crisis

OBJECTIVE

Reducing maternal morbidity and mortality has been a challenge for low and middle-income countries, especially in the setting of hypertensive disorders of pregnancy. Improved strategies for treating obstetric patients with resistant hypertension are needed. We sought to explore whether hemodynamic parameters may be used to identify patients that develop resistant hypertension in pregnancy.

METHODS

Retrospective cohort study among pregnant patients with gestational hypertension or preeclampsia that experienced severe blood pressure elevations. Hemodynamic variables were evaluated, including cardiac output (CO), and total peripheral resistance (TPR). The primary endpoint was resistant hypertension. An exploratory logistic regression was performed to evaluate the association between the hemodynamic profile and the development of resistant hypertension. Adverse maternal and fetal outcomes were additionally described according to the presence of resistant hypertension.

RESULTS

Fifty-seven patients with severe pregnancy hypertension were included, of whom 34 developed resistant hypertension (59.7%). The resistant hypertension group, in comparison to those without resistant hypertension, presented with a hypodynamic profile characterized by reduced CO < 5 L/min (41.2% vs. 8.7%, p: 0.007), and increased TPR > 1400 dyn-s/cm5 (64.7% vs. 39.1%, p: 0.057). Logistic regression analysis revealed an association between a hypodynamic profile and resistant hypertension (OR 3.252, 95% CI 1.079-9.804; p = 0.035). Newborns of the resistant hypertension group had more frequent low birth weight (<2500 g), low Apgar scores, ICU admissions, and acute respiratory distress syndrome.

CONCLUSION

Patients experiencing hypertensive crisis during pregnancy and exhibiting a hypodynamic profile (TPR ≥1400 dyn·s/cm5 and CO ≤ 5 L/min) developed higher rates of resistant hypertension.

Pregnancy-specific responses to COVID-19 revealed by high-throughput proteomics of human plasma

BACKGROUND

Pregnant women are at greater risk of adverse outcomes, including mortality, as well as obstetrical complications resulting from COVID-19. However, pregnancy-specific changes that underlie such worsened outcomes remain unclear.

METHODS

Plasma samples were collected from pregnant women and non-pregnant individuals (male and female) with (n = 72 pregnant, 52 non-pregnant) and without (n = 29 pregnant, 41 non-pregnant) COVID-19. COVID-19 patients were grouped as asymptomatic, mild, moderate, severe, or critically ill according to NIH classifications. Proteomic profiling of 7,288 analytes corresponding to 6,596 unique protein targets was performed using the SOMAmer platform.

RESULTS

Herein, we profile the plasma proteome of pregnant and non-pregnant COVID-19 patients and controls and show alterations that display a dose-response relationship with disease severity; yet, such proteomic perturbations are dampened during pregnancy. In both pregnant and non-pregnant state, the proteome response induced by COVID-19 shows enrichment of mediators implicated in cytokine storm, endothelial dysfunction, and angiogenesis. Shared and pregnancy-specific proteomic changes are identified: pregnant women display a tailored response that may protect the conceptus from heightened inflammation, while non-pregnant individuals display a stronger response to repel infection. Furthermore, the plasma proteome can accurately identify COVID-19 patients, even when asymptomatic or with mild symptoms.

CONCLUSION

This study represents the most comprehensive characterization of the plasma proteome of pregnant and non-pregnant COVID-19 patients. Our findings emphasize the distinct immune modulation between the non-pregnant and pregnant states, providing insight into the pathogenesis of COVID-19 as well as a potential explanation for the more severe outcomes observed in pregnant women.

Pregnancy-specific responses to COVID-19 are revealed by high-throughput proteomics of human plasma

Pregnant women are at greater risk of adverse outcomes, including mortality, as well as obstetrical complications resulting from COVID-19. However, pregnancy-specific changes that underlie such worsened outcomes remain unclear. Herein, we profiled the plasma proteome of pregnant and non-pregnant COVID-19 patients and controls and showed alterations that display a dose-response relationship with disease severity; yet, such proteomic perturbations are dampened during pregnancy. In both pregnant and non-pregnant state, the proteome response induced by COVID-19 showed enrichment of mediators implicated in cytokine storm, endothelial dysfunction, and angiogenesis. Shared and pregnancy-specific proteomic changes were identified: pregnant women display a tailored response that may protect the conceptus from heightened inflammation, while non-pregnant individuals display a stronger response to repel infection. Furthermore, the plasma proteome can accurately identify COVID-19 patients, even when asymptomatic or with mild symptoms. This study represents the most comprehensive characterization of the plasma proteome of pregnant and non-pregnant COVID-19 patients.

Chorion releases a factor that inhibits oxytocin-stimulated myometrial contractility in the pregnant guinea pig

It was postulated that chorion releases a substance necessary for the maintenance of uterine quiescence during pregnancy. A decrease in the release of this substance at the end of the pregnancy would be necessary for normal myometrial activation. This hypothesis was tested by demonstrating the ability of chorion to inhibit oxytocin-stimulated myometrial contractility in vitro. Tissues were obtained from timed pregnant Duncan-Hartley guinea pigs either at pre-term or near-term gestation. Myometrial strips were placed in organ baths for isometric tension measurement and contractions stimulated by oxytocin (10(-8) mol/l). Fetal membranes or conditioned medium from chorion were added directly to the organ bath. Near-term chorion and chorion conditioned-medium decreased oxytocin-stimulated contractile activity to 39% and 49% respectively. Neither pre-term nor near-term amnion reduced oxytocin-stimulated myometrial contractile activity. Relaxation induced by pre-term chorion was greater than near-term chorion (23% and 41% of the oxytocin-induced basal level respectively; P < 0.05). Further, chorion-induced relaxation was independent of the gestational age of the myometrium. Human chorion from a term, not-in-labour woman also inhibited oxytocin-stimulated guinea pig myometrial contractility. It was concluded that the chorion releases a substance or substances that reduce oxytocin-stimulated myometrial contractility and may be involved in the maintenance of uterine quiescence during pregnancy.

Natriuretic peptide-induced relaxation of myometrium from the pregnant guinea pig is not mediated by guanylate cyclase activation

We tested both relaxation and cGMP generation by atrial (ANP), brain (BNP), and C-type natriuretic peptide (CNP) in oxytocin-stimulated myometrium from near-term pregnant guinea pigs to investigate the ability and mechanism of natriuretic peptides to inhibit myometrial contractility. Myometrial strips were contracted by 10(-8) M oxytocin, and relaxation to the cumulative addition (10(-9)-10(-6) M) of the natriuretic peptides measured. Maximal relaxation to BNP was significantly greater than to ANP (52 versus 32% respectively; p < 0.05), whereas CNP failed to produce relaxation. However, the increase in cGMP produced by BNP (10(-7) M) was significantly less than that produced by ANP (10(-7) M) (4.5 versus 7.0 times basal; p < 0.05); CNP did not increase myometrial cGMP. Anantin, a competitive blocker of the guanylate cyclase A receptor, significantly reduced the increase in cGMP produced by ANP and BNP, but had no effect on relaxation induced by either peptide. Rp-8-Br-cGMP, an inhibitor of the cGMP-dependent protein kinase, did not alter BNP-induced relaxation. The atrial natriuretic peptide-fragment 4-23 amide, a natriuretic peptide clearance receptor agonist, failed to inhibit oxytocin-stimulated myometrial contraction. We conclude that natriuretic peptide induced relaxation of oxytocin-stimulated myometrium from the pregnant guinea pig is not mediated by either guanylate cyclase A or B activation, is independent of the cGMP pathway, and does not involve clearance receptor activation. Our results suggest that natriuretic peptide-induced relaxation of pregnant myometrium is mediated via a novel mechanism.

Application of a functional genomics approach to identify differentially expressed genes in human myometrium during pregnancy and labour

The molecular mechanisms regulating uterine relaxation and contraction during pregnancy are poorly understood. In the present study, we used for the first time a functional genomics approach applying gene array technology to identify novel candidate genes involved in the regulation of uterine quiescence and contractility during pregnancy. The purpose of this approach was to obtain a molecular snapshot of the expression profile of gene transcripts as a function of the time dependent process regulating myometrial quiescence. Using this approach, we found several genes whose expression in human myometrium was altered with the onset of labour. For example, the expression of insulin-like growth factor (IGF)-II, calgranulin A and B, and G-protein coupled receptor were decreased while the expression of IGF-binding proteins, Ca(2+)/CaM binding protein kinase C substrate, and angiotensin converting enzyme were increased in the labouring, compared with non-labouring, pregnant myometrium. The differentially-expressed genes include several genes whose roles in myometrial quiescence are yet to be understood, although they have been reported to regulate vascular smooth muscle tone. Our findings illustrate the advantage of a functional genomics approach over a single gene analysis in identifying a large number of novel and potentially important genes mediating uterine smooth muscle contractile activity.

Molecular mechanism of cGMP-mediated smooth muscle relaxation

Contraction and relaxation of smooth muscle is a tightly regulated process involving numerous endogenous substances and their intracellular second messengers. We examine the key role of cyclic guanosine monophosphate (cGMP) in mediating smooth muscle relaxation. We briefly review the current art regarding cGMP generation and degradation, while focusing on the recent identification of the molecular mechanisms underlying cGMP-mediated smooth muscle relaxation. cGMP-induced SM relaxation is mediated mainly by cGMP-dependent protein kinase activation. It involves several molecular events culminating in a reduction in intracellular Ca(2+) concentration and a decrease in the sensitivity of the contractile system to Ca(2+). We propose that the cGMP-induced decrease in Ca(2+) sensitivity is a strategic way to achieve "active relaxation" of the smooth muscle. In summary, we present compelling evidence supporting a key role for cGMP as a mediator of smooth muscle relaxation in physiological and pharmacological settings.

[The quality of antibiotic treatment in primary health care in the county of Osona (Barcelona)]

BACKGROUND

The evaluation and quality control of antibiotic prescription has become widespread in primary health care (PHC). Most of the studies performed have analyzed the quality of the drug and not the treatment. The aim of this study was to evaluate the quality of the antibiotic treatments of physicians in a concrete area and identify the most deficient aspects.

METHODS

A prospective study was performed with the voluntary participation of general physicians and pediatricians of the PHC area of Osona (Barcelona, Spain) by the collection of a series of data of each antibiotic treatment carried out over 30 days. Consideration of each item to evaluate the quality of a given treatment was carried out by a nominal group.

RESULTS

A total of 1,976 antibiotic treatments were administered by the 44 physicians participating in the study (68% of the target population). The aspect found to be most deficient was that 20% of the doctors prescribed an antibiotic in a diagnosis for which it was not susceptible and in 30% of the susceptible cases the choice of antibiotic was erroneous. The length of treatment was the aspect on posology showing the worst results (27% incorrect). The mean quality following the application of the scale elaborated by the nominal group was 72.6 (SD = 25.7) over a maximum of 100. Lower quality was observed in the pediatricians (p = 0.006), in the physicians working in the reformed network (p < 0.0001), in the prescriptions induced by another physician (p = 0.0001) and in those induced by the patient (p = 0.03).

CONCLUSIONS

The number of antibiotics prescribed in non susceptible processes in primary health care should be reduced. Likewise, the choice of antibiotics prescribed should improve.