Renin imprinted Poly(methyldopa) for biomarker detection and disease therapy

Conventional molecularly imprinted polymers (MIPs) perform their functions principally depended on their three dimensional (3D) imprinted cavities (recognition sites) of templates. Here, retaining the function of recognition sites resulted from the imprinting of template molecules, the role of functional monomers is explored and expanded. Briefly, a class of dual-functional renin imprinted poly(methyldopa) (RMIP) is prepared, consisting of a drug-type function monomer (methyldopa, clinical high blood pressure drug) and a corresponding disease biomarker (renin, biomarker for high blood pressure disease). To boost target-to-receptor binding ratio and sensitivity, the microstructure of recognition sites is beforehand calculated and designed by Density Functional Theory calculations, and the whole interfacial structure, property and thickness of RMIP film is regulated by adjusting the polymerization techniques. The dual-functional applications of RMIP for biomarker detection and disease therapy in vivo is explored. Such RMIP-based biosensors achieves highly sensitive biomarker detection, where the LODs reaches down to 1.31 × 10-6 and 1.26 × 10-6 ng mL-1 for electrochemical and chemical polymers, respectively, and the application for disease therapy in vivo has been verified where displays the obviously decreased blood pressure values of mice. No acute and long-term toxicity is found from the pathological slices, declaring the promising clinical application potential of such engineered RMIP nanostructure.

Understanding the riddle of amine oxidase flavoenzyme reactivity on the stereoisomers of N-methyl-dopa and N-methyl-tyrosine

Enzymes are usually stereospecific against chiral substrates, which is commonly accepted for the amine oxidase family of enzymes as well. However, the FsqB (fumisoquin biosynthesis gene B) enzyme that belongs to the family of sarcosine oxidase and oxidizes L-N-methyl-amino acids, shows surprising activity for both enantiomers of N-methyl-dopa. The aim of this study is to understand the mechanism behind this behavior. Primary docking experiments showed that tyrosine and aspartate residues (121 and 315 respectively) are located on the ceiling of the active site of FsqB and may play a role in fixing the N-methyl-dopa via its catechol moiety and allowing both stereoisomers of this substrate to be in close proximity of the N5 atom of the isoalloxazine ring of the cofactor. Three experimental approaches were used to prove this hypothesis which are: (1) studying the oxidative ability of the variants Y121F and D315A on N-methyl-dopa substrates in comparison with N-methyl-tyrosine substrates; (2) studying the FsqB WT and variants catalyzed biotransformation via high-performance liquid chromatography (HPLC); (3) molecular dynamics simulations to characterize the underlying mechanisms of the molecular recognition. First, we found that the chemical characteristics of the catechol moiety of N-methyl-dopa are important to explain the differences between N-methyl-dopa and N-methyl-tyrosine. Furthermore, we found that Y121 and D315 are specific in FsqB and not found in the model enzyme sarcosine oxidase. The on-bench and theoretical mutagenesis studies show that Y121 residue has a major role in fixing the N-methyl-dopa substrates close to the N5 atom of the isoalloxazine ring of the cofactor. Simultaneously, D315 has a supportive role in this mechanism. Jointly, the experimental and theoretical approaches help to solve the riddle of FsqB amine oxidase substrate specificity.

Treatment of acute-onset hypertension in pregnancy: A network meta-analysis of randomized controlled trials comparing anti-hypertensives and route of administration

BACKGROUND

Consensus on the relative efficacy of available antihypertensive agents used in pregnancy is lacking.

OBJECTIVE

To compare treatment success with antihypertensives and categorize by route of administration.

SEARCH STRATEGY

MEDLINE, Embase, PubMed, Web of Science, Scopus, CINAHL, and clinicaltrials.gov were searched without date restriction.

DATA COLLECTION

Peer-reviewed randomized controlled trials (RCTs) comparing pharmacologic agents used to treat hypertension in parturients were included. Evaluated treatment groups included IV-labetalol (BBIV), IV-hydralazine (DIV), oral-nifedipine (CCBPO), sublingual nifedipine (CCBSL), IV-calcium channel blocker (nonspecific)(CCBIV), IV-nitroglycerine (NTG), epoprostenol infusion (PRO), IV-ketanserin (5HT2B), IV-diazoxide (BZO), oral-nifedipine + methyldopa (CCBAG), oral-methyl-dopa (AAG), and oral prazosin (ABPO).

ANALYSIS

Seventy-four studies (8324 patients) were eligible post PRISMA guidelines screening. Results were pooled using a Bayesian-approach for success of treatment (study defined target blood pressure), time to achieve target pressure, and neonatal intensive-care admissions.

RESULTS

Treatment success (primary outcome, 55 trials with 5518 patients) was analyzed. Surface under the cumulative ranking curve (SUCRA) was categorized for 13 drugs, CCBPO (0.84) followed by CCBSL (0.78) were most likely to be effective in achieving target blood pressure. After sub-grouping by presence/absence of preeclampsia, CCB-PO ranked highest for both [(0.82) vs. (0.77), respectively]. Serotonin antagonists (0.99) and nitroglycerin (0.88) ranked highest for time to target pressure. NICU admissions were lowest for alpha-2 agonists (0.89), followed by BB PO (0.82) and hydralazine IV (0.49).

CONCLUSION

Oral calcium-channel blockers ranked highest for treatment success. Ketanserin achieved target blood pressure fastest, warranting additional research. The results should be interpreted with caution as SUCRA values may not indicate whether the differences between interventions have clinically meaningful effect sizes.

Association of metformin use with risk of newly onset neovascular age-related macular degeneration development

PURPOSE

To investigate if metformin use reduces the odds of developing new neovascular AMD (nAMD).

METHODS

This is a case-control study of 86,930 subjects with new diagnoses of nAMD and 86,918 matched controls using the Merative™ Marketscan® Research Databases. Subjects were analyzed using multivariable conditional logistic regression to identify the risks of various exposures on developing nAMD. A subgroup analysis of 22,117 diabetic cases and 21,616 diabetic controls was also performed.

RESULTS

Metformin use was associated with reduced odds ratio (OR) of developing nAMD (OR 0.95, 95% confidence interval 0.91-0.98) in full sample and diabetic cohort particularly in patients without any diabetic retinopathy (DR) -an effect that persisted after Bonferroni correction. In the diabetic cohort without DR, reduced OR was observed at 24-month cumulative doses of 1 to 300g, 301 to 630g, and 631 to 1080g.

CONCLUSIONS

Metformin use was associated with reduced OR of nAMD, particularly in patients without DR. The protective effect was noted for 24-month cumulative doses below 1080g. Metformin may be a novel preventive strategy for nAMD.

Dasatinib Plus Quercetin Alleviates Choroid Neovascularization by Reducing the Cellular Senescence Burden in the RPE-Choroid

Purpose

Wet AMD (wAMD) is associated with cellular senescence. However, senescent cell-targeted therapies for wAMD have rarely been comprehensively studied. This study aimed to explore the therapeutic effects of senolytic agents on choroidal neovascularization (CNV).

Methods

RNA sequencing datasets were obtained from the Gene Expression Omnibus database and used to explore the association between senescence and wAMD. We explored the effects of senescent adult RPE cell line-19 cells on the proliferation, migration, invasion, and tube formation of human umbilical vein endothelial cells. A laser-induced CNV animal model was used to study wAMD. We studied a senescent cell elimination therapy for CNV progression using two types of senolytics and a transgenic method.

Results

Cells in the retinal pigment epithelium-choroid of the CNV model were enriched in senescence, inflammation, and angiogenesis gene sets. AP20187 was used to specifically eliminate senescent cells and proven to alleviate CNV progression in INK-ATTAC transgenic mice. Senescent adult RPE cell line-1 cells produced elevated levels of senescence-associated secretory phenotypes, including VEGFs; they also demonstrated increased proliferation, migration, invasion, and tube formation in human umbilical vein endothelial cells. The number of senescent cells increased in the laser-induced CNV rat model, and intravitreal injections of dasatinib with quercetin reduced the expression of p16 in CNV and alleviated neovascularization.

Conclusions

Senescent RPE cells can accelerate pathological neovascularization; thus, senescent cell-targeting therapy has great clinical potential for wAMD.

Fatal pulmonary oedema associated with severe pre-eclampsia: challenges and lessons

Pre-eclampsia complicated by pulmonary oedema, severe hypertension, tachycardia and desaturation is a devastating condition. A comprehensive understanding of the aetiopathogenesis during such an emergency is challenging in the absence of functional and responsive point-of-care imaging, and laboratory and other critical-care services. An unbooked 26-year-old gravida 3 para 1+1 presented to a primary healthcare clinic with features of pre-eclampsia, severe hypertension and pulmonary oedema. The only available antihypertensive drug, methyldopa, was administered. The patient was transferred to a district hospital and subsequently referred to a tertiary hospital. On arrival, she was booked for caesarean delivery and in the maternity ward a central venous pressure (CVP) line was inserted. The patient developed pneumothorax and died in the intensive care unit undelivered. This case highlights many lessons, which are discussed. If CVP monitoring is indicated before caesarean delivery, consideration must be given to line insertion in the operating room to facilitate rapid delivery should the patient's condition deteriorate.

Fabrication of a sensitive sensor for electrochemical detection of diltiazem in presence of methyldopa

Diltiazem (DTZ) is one of the most important drugs in blood pressure that is used to treat cardiovascular diseases. With this overuse of this drug and its use for suicide, swelling and neck cramps and fever has made it important to measure it. So, this paper will give an account of modification of carbon paste electrode with the ternary-nanocomposite including reduced-graphene oxide (rGO), cadmium oxide and 1-ethyl 3- methyl imidazole chloride as ionic liquid for using the determination of DTZ in blood serum samples. Characterization of the synthesized rGO, cadmium oxide, and modified electrodes and their electrochemical performance were studied by, scanning electron microscopy, and X-ray diffraction, electrochemical impedance spectroscopy, and voltammetry technique. The improvement of the DTZ oxidation current by modified electrode originated from the increased electrode surface area. The optimized method was validated and the results showed that LOD = 3 nM and good linearity. Also, a linear concentration range of 0.01-150 μM with a LOD of 0.03 μM in presence methyldopa were achieved based on the electrochemical investigations. The prepared sensor showed good repeatability (RSD = 2.26%) and selectivity for DTZ determination in the real samples (relative recovery of 93-102%).

Mechanism of catalytic ozonation for elimination of methyldopa with Fe3 O4 @SiO2 @CeO2 catalyst

In this study, a magnetic nanocatalyst (Fe₃ O₄ @SiO₂ @CeO₂ ) was prepared and applied in the catalytic ozonation of methyldopa (MD). The effects of operational parameters on catalytic ozonation performance were investigated, including ozone dosage, catalyst dosage, initial MD concentration, and pH. The removal of MD was 45.2% in ozonation, whereas the efficiency was achieved to 83.0% with the addition of Fe₃ O₄ @SiO₂ @CeO₂ . The results showed that Fe₃ O₄ @SiO₂ @CeO₂ could significantly improve the catalytic ozonation performance. And the enhanced mechanism study showed that it was attributed to promotion of ozone decomposition to generate hydroxyl radical. The reaction model was explored, and the reaction rates were calculated for the MD degradation in catalytic ozonation. A higher degradation efficiency of MD in catalytic ozonation was attributed to the enhanced surface effect of the catalysts, which was confirmed by using TBA, PO₄ ^3- , and p-BQ as scavengers of hydroxyl radical, surface reaction, and superoxide radical. The hydroxyl radical and superoxide radical played an important role in the degradation of MD. The mechanism of catalytic ozonation by Fe₃ O₄ @SiO₂ @CeO₂ was discussed via X-ray photoelectron spectroscopy (XPS) spectra and experimental data.

Pharmacotherapy for hypertension-induced left ventricular hypertrophy

BACKGROUND

Hypertension is the leading preventable risk factor for cardiovascular disease and premature death worldwide. One of the clinical effects of hypertension is left ventricular hypertrophy (LVH), a process of cardiac remodelling. It is estimated that over 30% of people with hypertension also suffer from LVH, although the prevalence rates vary according to the LVH diagnostic criteria. Severity of LVH is associated with a higher prevalence of cardiovascular disease and an increased risk of death. The role of antihypertensives in the regression of left ventricular mass has been extensively studied. However, uncertainty exists regarding the role of antihypertensive therapy compared to placebo in the morbidity and mortality of individuals with hypertension-induced LVH.

OBJECTIVES

To assess the effect of antihypertensive pharmacotherapy compared to placebo or no treatment on morbidity and mortality of adults with hypertension-induced LVH.

SEARCH METHODS

Cochrane Hypertension's Information Specialist searched the following databases for studies: Cochrane Hypertension Specialised Register (to 26 September 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; 2020, Issue 9), Ovid MEDLINE (1946 to 22 September 2020), and Ovid Embase (1974 to 22 September 2020). We searched the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov for ongoing trials. We also searched Epistemonikos (to 19 February 2021), LILACS BIREME (to 19 February 2021), and Clarivate Web of Science (to 26 February 2021), and contacted authors and funders of the identified trials to obtain additional information and individual participant data. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with at least 12 months' follow-up comparing antihypertensive pharmacological therapy (monotherapy or in combination) with placebo or no treatment in adults (18 years of age or older) with hypertension-induced LVH were eligible for inclusion. The trials must have analysed at least one primary outcome (all-cause mortality, cardiovascular events, or total serious adverse events) to be considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results, with any disagreements resolved by consensus amongst all review authors. Two review authors carried out the data extraction and analyses. We assessed risk of bias of the included studies following Cochrane methodology. We used the GRADE approach to assess the certainty of the body of evidence.

MAIN RESULTS

We included three multicentre RCTs. We selected 930 participants from the included studies for the analyses, with a mean follow-up of 3.8 years (range 3.5 to 4.3 years). All of the included trials performed an intention-to-treat analysis. We obtained evidence for the review by identifying the population of interest from the trials' total samples. None of the trials provided information on the cause of LVH. The intervention varied amongst the included trials: hydrochlorothiazide plus triamterene with the possibility of adding alpha methyldopa, spironolactone, or olmesartan. Placebo was administered to participants in the control arm in two trials, whereas participants in the control arm of the remaining trial did not receive any add-on treatment. The evidence is very uncertain regarding the effect of additional antihypertensive pharmacological therapy compared to placebo or no treatment on mortality (14.3% intervention versus 13.6% control; risk ratio (RR) 1.02, 95% confidence interval (CI) 0.74 to 1.40; 3 studies; 930 participants; very low-certainty evidence); cardiovascular events (12.6% intervention versus 11.5% control; RR 1.09, 95% CI 0.77 to 1.55; 3 studies; 930 participants; very low-certainty evidence); and hospitalisation for heart failure (10.7% intervention versus 12.5% control; RR 0.82, 95% CI 0.57 to 1.17; 2 studies; 915 participants; very low-certainty evidence). Although both arms yielded similar results for total serious adverse events (48.9% intervention versus 48.1% control; RR 1.02, 95% CI 0.89 to 1.16; 3 studies; 930 participants; very low-certainty evidence) and total adverse events (68.3% intervention versus 67.2% control; RR 1.07, 95% CI 0.86 to 1.34; 2 studies; 915 participants), the incidence of withdrawal due to adverse events may be significantly higher with antihypertensive drug therapy (15.2% intervention versus 4.9% control; RR 3.09, 95% CI 1.69 to 5.66; 1 study; 522 participants; very low-certainty evidence). Sensitivity analyses limited to blinded trials, trials with low risk of bias in core domains, and trials with no funding from the pharmaceutical industry did not change the results of the main analyses. Limited evidence on the change in left ventricular mass index prevented us from drawing any firm conclusions.

AUTHORS' CONCLUSIONS

We are uncertain about the effects of adding additional antihypertensive drug therapy on the morbidity and mortality of participants with LVH and hypertension compared to placebo. Although the incidence of serious adverse events was similar between study arms, additional antihypertensive therapy may be associated with more withdrawals due to adverse events. Limited and low-certainty evidence requires that caution be used when interpreting the findings. High-quality clinical trials addressing the effect of antihypertensives on clinically relevant variables and carried out specifically in individuals with hypertension-induced LVH are warranted.

Effect of antihypertensive therapy with alpha-methyldopa on umbilical artery Doppler in pregnancies with hypertensive disorders

Aim To clarify whether applying alpha-methyldopa treatment influences flow resistance in umbilical cord artery in pregnant women suffering from hypertensive disorder. Methods In this prospective cross-sectional study a follow-up was done for 50 pregnant women with singleton pregnancies between 36 and 40 gestation weeks, who had been hospitalized at the Gynecology and Obstetrics Department of the Cantonal Hospital Zenica, Bosnia and Herzegovina from October 2009 to January 2012. Pregnant women were classified in two groups according to the level of using alpha-methyldopa in the treatment. For all expectant mothers, flow in umbilical cord artery was measured, Resistance Index (RI) was determined and values were compared accordingly. Results There was a statistically significant difference in values of umbilical artery resistance index (UA RI) in terms mother's hypertension (p less than 0.05). Therefore, mothers with chronic hypertension had the highest UA RI (0.885±0.4), as well as mothers with preeclampsia superimposed on chronic hypertension (0.785±0.7), while mothers with gestational hypertension had the lowest UA RI (0.6413±0.13) (p less than 0.05). In mothers using the methyldopa UA RI was lower (0.6875±0.14) in comparison to those who did not use it (0.6686±0.13) but with no statistical significance (p greater than 0.05). Conclusion There was no change in flow resistance in umbilical cord artery in pregnant women suffering from hypertensive disorder. Key words: ultrasonography, umbilical artery, pregnancy-induced hypertension.

Inhibition of endotoxin-induced pulmonary vascocontriction in dogs by alpha-methyl dopa

The demonstration in a previous study of the effectiveness of an antihistaminic drug in blocking some of the systemic but not the pulmonary vascular effects of endotoxin led to the study of the effect of an inhibitor of serotonin synthesis, alpha-methyl 3,4-dihydroxyphenylalanine (α-m dopa). One group of seven dogs was pretreated with a single dose of 250 mg, and a second group of six animals with three doses of 250 mg, each given at 10-min intervals. Results in these two groups were compared with those in six control animals. Purified E. coli endotoxin, 1 mg/kg, was administered intravenously in all 19 experiments. Intravenous administration of α-m dopa alone had no effect on measured physiologic parameters. Compared with the endotoxin response in control animals, pretreatment with either dose level appeared to have no effect on the magnitude or duration of systemic arterial hypotension, portal venous hypertension, or drop in cardiac output. However, pretreatment with 250-mg and 750-mg doses was associated with significant reduction and abolition, respectively, of pulmonary arterial hypertension. The results are consistent with the interpretation that the pulmonary vasoconstrictive response to endotoxin is mediated through the release of serotonin and that α-m dopa blocks this response by interfering with the synthesis of this intermediary.

The pharmacological actions of 3,4-dihydroxyphenyl-alpha-methylalanine (alpha-methyldopa), an inhibitor of 5-hydroxytryptophan decarboxylase

alpha-Methyldopa (3,4-dihydroxyphenyl-alpha-methylalanine) is an inhibitor of 5-hydroxytryptophan decarboxylase which is effective in vitro and in vivo. The inhibition is complex and shows coenzyme reversal. Evidence is presented that it acts by coenzyme inactivation. Its administration to mice reduced brain 5-hydroxytryptamine but had no effect on noradrenaline. After repeated doses, intestinal 5-hydroxytryptamine concentrations were also reduced. Co-ordinated activity was diminished coincidently with the enzyme inhibition and the reduction in brain 5-hydroxytryptamine. Rectal temperatures were reduced and the possibility that this resulted from inactivity is discussed. Treated animals showed miosis and narrowing of the palpebral fissures. A comparison is drawn between the actions of alpha-methyldopa and reserpine. The present results support the idea that the sedative effects of both drugs are due to the fall in brain 5-hydroxytryptamine concentration that they produce.

A study of potential histidine decarboxylase inhibitors

A series of compounds has been examined for ability to inhibit histidine decarboxylase. Histidine analogues having substituents in the imidazole ring showed a wide variation in potency, but these were all much less active than alpha-methyldopa [beta-(3,4-dihydroxyphenyl)-alpha-methylalanine], the most potent known inhibitor of histidine decarboxylase. Some tentative conclusions are drawn regarding the relationship between chemical structure and inhibitory activity.

REVERSAL OF THE EFFECT OF ALPHA-METHYLDOPA BY MONOAMINE OXIDASE INHIBITORS

L-α-Methyldopa, which normally causes sedation, induces a strong central excitation in mice pretreated with a monoamine oxidase inhibitor after a lag of a few hours. It is concluded that this excitation is caused by accumulation of free catecholamines liberated by amines which are slowly formed by decarboxylation of α-methyldopa. The hypotensive and sedative effects of α-methyldopa given alone are attributed to the slow release of catecholamines and subsequent breakdown by monoamine oxidase so that a partial depletion of catecholamines ensues.

SOME OBSERVATIONS ON THE PHARMACOLOGY OF ALPHA-METHYLDOPA

alpha-Methyldopa in high concentrations impaired the responses of rabbit isolated ileum and guinea-pig isolated vas deferens to stimulation of the sympathetic nerves and to noradrenaline, but these preparations taken from animals previously treated with alpha-methyldopa showed no sign of impairment. Contractions of the cat nictitating membrane were reduced but not abolished by alpha-methyldopa. In cats, dogs and rats, pressor responses to noradrenaline were usually slightly increased by alpha-methyldopa. Pressor responses to tyramine were not affected consistently. alpha-Methyldopa, alpha-methyldopamine and alpha-methylnoradrenaline behaved like dopa, dopamine and noradrenaline respectively in restoring the responses of tissues from reserpine-treated animals to stimulation of the sympathetic nerves to the rabbit ileum, the guinea-pig vas deferens and the cat nictitating membrane and in restoring responses to tyramine of the cat blood pressure and nictitating membrane, and the rat blood pressure. The potency of alpha-methylnoradrenaline relative to noradrenaline ranged from one-half to one-ninth on various preparations. The results are discussed in relation to the antihypertensive action of alpha-methyldopa.