Validation of Risk Stratification for Cardiac Events in Pregnant Women With Valvular Heart Disease.

BACKGROUND: Most risk stratification tools for pregnant patients with heart disease were developed in high-income countries and in populations with predominantly congenital heart disease, and therefore, may not be generalizable to those with valvular heart disease (VHD). OBJECTIVES: The purpose of this study was to validate and establish the clinical utility of 2 risk stratification tools-DEVI (VHD-specific tool) and CARPREG-II-for predicting adverse cardiac events in pregnant patients with VHD. METHODS: We conducted a cohort study involving consecutive pregnancies complicated with VHD admitted to a tertiary center in a middle-income setting from January 2019 to April 2022. Individual risk for adverse composite cardiac events was calculated using DEVI and CARPREG-II models. Performance was assessed through discrimination and calibration characteristics. Clinical utility was evaluated with Decision Curve Analysis. RESULTS: Of 577 eligible pregnancies, 69 (12.1%) experienced a component of the composite outcome. A majority (94.7%) had rheumatic etiology, with mitral regurgitation as the predominant lesion (48.2%). The area under the receiver-operating characteristic curve was 0.884 (95% CI: 0.844-0.923) for the DEVI and 0.808 (95% CI: 0.753-0.863) for the CARPREG-II models. Calibration plots suggested that DEVI score overestimates risk at higher probabilities, whereas CARPREG-II score overestimates risk at both extremes and underestimates risk at middle probabilities. Decision curve analysis demonstrated that both models were useful across predicted probability thresholds between 10% and 50%. CONCLUSIONS: In pregnant patients with VHD, DEVI and CARPREG-II scores showed good discriminative ability and clinical utility across a range of probabilities. The DEVI score showed better agreement between predicted probabilities and observed events.

Outcomes of patients with indolent lymphoma treated with bendamustine plus rituximab compared to rituximab plus CVP or CHOP chemoimmunotherapy in Ontario.

Bendamustine (B) with rituximab (R) has become the preferred regimen for patients with indolent lymphoma in Ontario, Canada, compared to R with cyclophosphamide, vincristine, prednisone (CVP) or cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP). We conducted a propensity-matched retrospective cohort population-based study of patients treated with R-CVP/CHOP from 2005 to 2012 and patients treated with BR from 2013 to 2018. The primary outcome was 5-year overall survival (OS), and secondary outcomes included toxicities and healthcare utilization. The 5-year OS for patients treated with BR (n = 2023) and R-CVP/CHOP (n = 2023) was 80% and 75% respectively. Treatment with BR was associated with improved OS (HR 0.79, 95% CI 0.69-0.91). During the first 9 months, patients treated with BR versus R-CVP/CHOP had a higher number of admissions for infection (22% compared to 17%, p < 0.01) and a higher number of mean ED visits (mean 1.01 ± 1.68 visits vs. 0.85 ± 1.51 visits, p < 0.01). This trend persisted for 3 years. The adjusted 5-year OS for patients 75 years and older did not differ based on treatment regimen (55.5% for BR vs. 55.4% for R-CVP/CHOP). Our study supports the use of BR for patients with indolent lymphoma requiring treatment but suggests increased risk of certain toxicities warranting careful patient selection.

Ebstein's anomaly during pregnancy: experience from a tertiary care centre - a case series and review of literature.

Pregnancy complicated with uncorrected Ebstein's anomaly is uncommon and may pose a serious threat to maternal and foetal life in the clinical setting of altered hemodynamics of pregnancy. Data of eight pregnancies in four women with Ebstein's anomaly who delivered in a tertiary care institute was analysed. Among the four women, one had associated atrial septal defect, one had pulmonary hypertension and three had right bundle branch block. There were two miscarriages and six successful pregnancies resulting in live births. Three of the pregnancies were delivered by caesarean section. There was one pregnancy complicated by severe preeclampsia, no preterm births or maternal cardiac complications. There was one neonate with congenital ostium secundum atrial septal defect. All patients were managed by a multidisciplinary team involving Obstetrician, Cardiologist, Anaesthesiologist and Neonatologist.IMPACT STATEMENTWhat is already known on this subject? Ebstein's anomaly is a rare congenital anomaly with apical displacement of the septal tricuspid leaflet in association with leaflet dysplasia. It may cause varied presentation in pregnancy depending on the severity of the lesion.What do the results of this study add? Ebstein's anomaly may become symptomatic for the first-time during pregnancy. Patients with NYHA class II symptoms and no cyanosis generally tolerate pregnancy well. Miscarriages and intrauterine growth restriction may occur in the presence of this condition. Vaginal delivery is advised and caesarean is done only for obstetric indications.What are the implications of these findings for clinical practise and/or future research? The management of pregnancy with uncorrected Ebstein's anomaly is highly challenging especially in a low resource setting and requires tertiary centre care. Multidisciplinary team involvement can help to improve the outcomes in such pregnancies.

Prophylactic magnesium sulphate in prevention of eclampsia in women with severe preeclampsia: randomised controlled trial (PIPES trial).

Optimum dose, route and duration of use of prophylactic magnesium sulphate in women with severe pre-eclampsia is still controversial. We compared the efficacy and safety of 'low-dose Dhaka' regime with 'Loading dose only' regime for seizure prophylaxis in severe preeclampsia using a randomised controlled trial in 402 women. The incidence of eclampsia in the 'low-dose Dhaka' regime group was 1.49% and that in the 'Loading dose only regime' was 2.98% (p = .321). In the low-dose Dhaka regime, injection site abscess and respiratory depression occurred in one woman each. Neonatal outcomes such as Apgar score at 5 minutes (5.0% vs. 8.05% p = .251) and perinatal mortality (20.4% vs. 21.9%, p = .724) were similar in both groups. Loading dose only regime may be considered an effective alternative regime for the prevention of eclampsia in women with severe preeclampsia. Impact statement What is already known on this subject: Efficacy of therapeutic short regime magnesium sulphate in eclampsia has already been reported. Data regarding prophylactic short regime in women with preeclampsia is sparse. What the results of this study add: We have shown that short regime of magnesium sulphate using only the loading dose in the prevention of seizure in preeclampsia is an effective alternative to the low-dose Dhaka regime. What the implications are of these findings for clinical practice and/or further research: The short regime is less resource-intensive. Further larger studies are needed to confirm the efficacy of this short regime and to establish its cost-effectiveness.

Maternal ascites an independent prognostic factor in severe preeclampsia: a matched cohort study.

BACKGROUND: Preeclampsia is a multi-systemic, multi-organ dysfunction associated with increased maternal and perinatal complications. The presence of maternal ascites, a manifestation of endothelial dysfunction and increased capillary permeability, is shown to be associated with adverse outcomes. We aim to investigate the impact of maternal ascites on pregnancy outcome in women with severe preeclampsia. METHODS: A matched cohort study was conducted in a tertiary care teaching hospital in South India between March 2014 and March 2015. One hundred and twenty-one severe preeclamptic women with ascites formed the study cohort while age-, parity-, and gestational age-matched group of 121 severe preeclamptic women without ascites formed the control. Primary outcome was the composite maternal adverse outcome defined as the development of any of eclampsia, pulmonary edema, renal failure, or disseminated intravascular coagulation (DIC). Secondary outcome was the composite perinatal outcome defined as the occurrence of any of still birth, hypoxic ischemic encephalopathy or early neonatal death. RESULTS: Four maternal deaths occurred in the study group. The rates of pregnancies with composite maternal adverse outcome [42 vs 9% RR 4.6 (95% CI 2.5-8.4)] and composite perinatal adverse outcome [36 vs 17% RR 2.1, (95% CI 1.3-3.3)] were significantly more in ascites group than in control group. After adjusting for other confounding variables, ascites was independently associated with adverse maternal events [adjusted OR 16.40 (95% CI 2.88-93.31)] but not adverse perinatal outcome. CONCLUSION: In women with severe preeclampsia, maternal ascites is an independent risk factor for adverse maternal outcome.

Production of Enzymes From Agricultural Wastes and Their Potential Industrial Applications.

Enzymatic hydrolysis is the significant technique for the conversion of agricultural wastes into valuable products. Agroindustrial wastes such as rice bran, wheat bran, wheat straw, sugarcane bagasse, and corncob are cheapest and plentifully available natural carbon sources for the production of industrially important enzymes. Innumerable enzymes that have numerous applications in industrial processes for food, drug, textile, and dye use have been produced from different types of microorganisms from agricultural wastes. Utilization of agricultural wastes offers great potential for reducing the production cost and increasing the use of enzymes for industrial purposes. This chapter focuses on economic production of actinobacterial enzymes from agricultural wastes to make a better alternative for utilization of biomass generated in million tons as waste annually.

Marine Microbial Amylases: Properties and Applications.

Amylases are crucial enzymes which hydrolyze internal glycosidic linkages in starch and produce as primary products dextrins and oligosaccharides. Amylases are classified into α-amylase, ß-amylase, and glucoamylase based on their three-dimensional structures, reaction mechanisms, and amino acid sequences. Amylases have innumerable applications in clinical, medical, and analytical chemistries as well as in food, detergent, textile, brewing, and distilling industries. Amylases can be produced from plants, animals, and microbial sources. Due to the advantages in microbial production, it meets commercial needs. The pervasive nature, easy production, and wide range of applications make amylase an industrially pivotal enzyme. This chapter will focus on amylases found in marine microorganisms, their potential industrial applications, and how these enzymes can be improved to the required bioprocessing conditions.

Enzymes From Rare Actinobacterial Strains.

Actinobacteria constitute rich sources of novel biocatalysts and novel natural products for medical and industrial utilization. Although actinobacteria are potential source of economically important enzymes, the isolation and culturing are somewhat tough because of its extreme habitats. But now-a-days, the rate of discovery of novel compounds producing actinomycetes from soil, freshwater, and marine ecosystem has increased much through the developed culturing and genetic engineering techniques. Actinobacteria are well-known source of their bioactive compounds and they are the promising source of broad range of industrially important enzymes. The bacteria have the capability to degrade a range of pesticides, hydrocarbons, aromatic, and aliphatic compounds (Sambasiva Rao, Tripathy, Mahalaxmi, & Prakasham, 2012). Most of the enzymes are mainly derived from microorganisms because of their easy of growth, minimal nutritional requirements, and low-cost for downstream processing. The focus of this review is about the new, commercially useful enzymes from rare actinobacterial strains. Industrial requirements are now fulfilled by the novel actinobacterial enzymes which assist the effective production. Oxidative enzymes, lignocellulolytic enzymes, extremozymes, and clinically useful enzymes are often utilized in many industrial processes because of their ability to catalyze numerous reactions. Novel, extremophilic, oxidative, lignocellulolytic, and industrially important enzymes from rare Actinobacterial population are discussed in this chapter.

Extremozymes from Marine Actinobacteria.

Marine microorganisms that have the possibility to survive in diverse conditions such as extreme temperature, pH, pressure, and salinity are known as extremophiles. They produce biocatalysts so named as extremozymes that are active and stable at extreme conditions. These enzymes have numerous industrial applications due to its distinct properties. Till now, only a fraction of microorganisms on Earth have been exploited for screening of extremozymes. Novel techniques used for the cultivation and production of extremophiles, as well as cloning and overexpression of their genes in various expression systems, will pave the way to use these enzymes for chemical, food, pharmaceutical, and other industrial applications.

Structural basis of genomic RNA (gRNA) dimerization and packaging determinants of mouse mammary tumor virus (MMTV).

BACKGROUND: One of the hallmarks of retroviral life cycle is the efficient and specific packaging of two copies of retroviral gRNA in the form of a non-covalent RNA dimer by the assembling virions. It is becoming increasingly clear that the process of dimerization is closely linked with gRNA packaging, and in some retroviruses, the latter depends on the former. Earlier mutational analysis of the 5' end of the MMTV genome indicated that MMTV gRNA packaging determinants comprise sequences both within the 5' untranslated region (5' UTR) and the beginning of gag. RESULTS: The RNA secondary structure of MMTV gRNA packaging sequences was elucidated employing selective 2'hydroxyl acylation analyzed by primer extension (SHAPE). SHAPE analyses revealed the presence of a U5/Gag long-range interaction (U5/Gag LRI), not predicted by minimum free-energy structure predictions that potentially stabilizes the global structure of this region. Structure conservation along with base-pair covariations between different strains of MMTV further supported the SHAPE-validated model. The 5' region of the MMTV gRNA contains multiple palindromic (pal) sequences that could initiate intermolecular interaction during RNA dimerization. In vitro RNA dimerization, SHAPE analysis, and structure prediction approaches on a series of pal mutants revealed that MMTV RNA utilizes a palindromic point of contact to initiate intermolecular interactions between two gRNAs, leading to dimerization. This contact point resides within pal II (5' CGGCCG 3') at the 5' UTR and contains a canonical "GC" dyad and therefore likely constitutes the MMTV RNA dimerization initiation site (DIS). Further analyses of these pal mutants employing in vivo genetic approaches indicate that pal II, as well as pal sequences located in the primer binding site (PBS) are both required for efficient MMTV gRNA packaging. CONCLUSIONS: Employing structural prediction, biochemical, and genetic approaches, we show that pal II functions as a primary point of contact between two MMTV RNAs, leading to gRNA dimerization and its subsequent encapsidation into the assembling virus particles. The results presented here enhance our understanding of the MMTV gRNA dimerization and packaging processes and the role of structural motifs with respect to RNA-RNA and possibly RNA-protein interactions that might be taking place during MMTV life cycle.

SHAPE analysis of the 5' end of the Mason-Pfizer monkey virus (MPMV) genomic RNA reveals structural elements required for genome dimerization.

Earlier genetic and structural prediction analyses revealed that the packaging determinants of Mason Pfizer monkey virus (MPMV) include two discontinuous core regions at the 5' end of its genomic RNA. RNA secondary structure predictions suggested that these packaging determinants fold into several stem-loops (SLs). To experimentally validate this structural model, we employed selective 2' hydroxyl acylation analyzed by primer extension (SHAPE), which examines the flexibility of the RNA backbone at each nucleotide position. Our SHAPE data validated several predicted structural motifs, including U5/Gag long-range interactions (LRIs), a stretch of single-stranded purine (ssPurine)-rich region, and a distinctive G-C-rich palindromic (pal) SL. Minimum free-energy structure predictions, phylogenetic, and in silico modeling analyses of different MPMV strains revealed that the U5 and gag sequences involved in the LRIs differ minimally within strains and maintain a very high degree of complementarity. Since the pal SL forms a helix loop containing a canonical "GC" dyad, it may act as a RNA dimerization initiation site (DIS), enabling the virus to package two copies of its genome. Analyses of wild-type and pal mutant RNAs revealed that disruption of pal sequence strongly affected RNA dimerization. However, when in vitro transcribed trans-complementary pal mutants were incubated together showed RNA dimerization was restored authenticating that the pal loop (5'-CGGCCG-3') functions as DIS.

Optimal packaging of FIV genomic RNA depends upon a conserved long-range interaction and a palindromic sequence within gag.

The feline immunodeficiency virus (FIV) is a lentivirus that is related to human immunodeficiency virus (HIV), causing a similar pathology in cats. It is a potential small animal model for AIDS and the FIV-based vectors are also being pursued for human gene therapy. Previous studies have mapped the FIV packaging signal (ψ) to two or more discontinuous regions within the 5' 511 nt of the genomic RNA and structural analyses have determined its secondary structure. The 5' and 3' sequences within ψ region interact through extensive long-range interactions (LRIs), including a conserved heptanucleotide interaction between R/U5 and gag. Other secondary structural elements identified include a conserved 150 nt stem-loop (SL2) and a small palindromic stem-loop within gag open reading frame that might act as a viral dimerization initiation site. We have performed extensive mutational analysis of these sequences and structures and ascertained their importance in FIV packaging using a trans-complementation assay. Disrupting the conserved heptanucleotide LRI to prevent base pairing between R/U5 and gag reduced packaging by 2.8-5.5 fold. Restoration of pairing using an alternative, non-wild type (wt) LRI sequence restored RNA packaging and propagation to wt levels, suggesting that it is the structure of the LRI, rather than its sequence, that is important for FIV packaging. Disrupting the palindrome within gag reduced packaging by 1.5-3-fold, but substitution with a different palindromic sequence did not restore packaging completely, suggesting that the sequence of this region as well as its palindromic nature is important. Mutation of individual regions of SL2 did not have a pronounced effect on FIV packaging, suggesting that either it is the structure of SL2 as a whole that is necessary for optimal packaging, or that there is redundancy within this structure. The mutational analysis presented here has further validated the previously predicted RNA secondary structure of FIV ψ.

A G-C-rich palindromic structural motif and a stretch of single-stranded purines are required for optimal packaging of Mason-Pfizer monkey virus (MPMV) genomic RNA.

During retroviral RNA packaging, two copies of genomic RNA are preferentially packaged into the budding virus particles whereas the spliced viral RNAs and the cellular RNAs are excluded during this process. Specificity towards retroviral RNA packaging is dependent upon sequences at the 5' end of the viral genome, which at times extend into Gag sequences. It has earlier been suggested that the Mason-Pfizer monkey virus (MPMV) contains packaging sequences within the 5' untranslated region (UTR) and Gag. These studies have also suggested that the packaging determinants of MPMV that lie in the UTR are bipartite and are divided into two regions both upstream and downstream of the major splice donor. However, the precise boundaries of these discontinuous regions within the UTR and the role of the intervening sequences between these dipartite sequences towards MPMV packaging have not been investigated. Employing a combination of genetic and structural prediction analyses, we have shown that region "A", immediately downstream of the primer binding site, is composed of 50 nt, whereas region "B" is composed of the last 23 nt of UTR, and the intervening 55 nt between these two discontinuous regions do not contribute towards MPMV RNA packaging. In addition, we have identified a 14-nt G-C-rich palindromic sequence (with 100% autocomplementarity) within region A that has been predicted to fold into a structural motif and is essential for optimal MPMV RNA packaging. Furthermore, we have also identified a stretch of single-stranded purines (ssPurines) within the UTR and 8 nt of these ssPurines are duplicated in region B. The native ssPurines or its repeat in region B when predicted to refold as ssPurines has been shown to be essential for RNA packaging, possibly functioning as a potential nucleocapsid binding site. Findings from this study should enhance our understanding of the steps involved in MPMV replication including RNA encapsidation process.