Lower gastrointestinal bleeding in pregnancy: Differential diagnosis, assessment and management

Rectal bleeding is a common symptom experienced by pregnant women. Although the majority of cases are attributable to benign conditions such as haemorrhoids and anal fissures, other more serious diagnoses such as inflammatory bowel disease and malignancy should not be overlooked. Most investigations are safe during pregnancy and these should not be withheld as significant implications on both fetal and maternal morbidity may result. In these cases, a multidisciplinary team approach is essential. This review explores the differential diagnosis, investigation and management of rectal bleeding during pregnancy.

Active microrheology using pulsed optical tweezers to probe viscoelasticity of lamin A

Lamins are nucleoskeletal proteins of mammalian cells that stabilize the structure and maintain the rigidity of the nucleus. These type V intermediate filament proteins which are predominantly of A and B types provide necessary tensile strength to the nucleus. Single amino acid missense mutations occurring all over the lamin A protein form a cluster of human diseases termed as laminopathies, most of which principally affect the muscle and cardiac tissues responsible for load bearing functionalities of the body. One such mutation is A350P which causes dilated cardiomyopathy in patients. It is postulated that a change from alanine to proline in the α-helical coiled-coil forming 2B rod domain of the protein might severely disrupt the propensity of the filaments to polymerise into functional higher order structures required to form a fully functional lamina with its characteristic elasticity. In this study, we have elucidated for the very first time, the application of active microrheology employing oscillating optical tweezers to investigate any alterations in the viscoelastic parameters of the mutant protein meshwork in vitro, which might translate into possible changes in nuclear plasticity. We confirmed our findings from this robust yet fast method by imaging both the wild type and mutant lamin A networks using a super resolution microscope, and observed changes in the mesh size which corroborate our measured changes in the viscoelastic parameters of the lamins. This method could thus be extended to conduct microrheological measurements on any intermediate filament protein thus bearing significant implications in laminopathies and other diseases associated with intermediate filaments.

Do Multiple Drug Resistance Transporters Interfere with Cell Functioning under Normal Conditions?

Eukaryotic cells rely on multiple mechanisms to protect themselves from exogenous toxic compounds. For instance, cells can limit penetration of toxic molecules through the plasma membrane or sequester them within the specialized compartments. Plasma membrane transporters with broad substrate specificity confer multiple drug resistance (MDR) to cells. These transporters efflux toxic compounds at the cost of ATP hydrolysis (ABC-transporters) or proton influx (MFS-transporters). In our review, we discuss the possible costs of having an active drug-efflux system using yeast cells as an example. The pleiotropic drug resistance (PDR) subfamily ABC-transporters are known to constitutively hydrolyze ATP even without any substrate stimulation or transport across the membrane. Besides, some MDR-transporters have flippase activity allowing transport of lipids from inner to outer lipid layer of the plasma membrane. Thus, excessive activity of MDR-transporters can adversely affect plasma membrane properties. Moreover, broad substrate specificity of ABC-transporters also suggests the possibility of unintentional efflux of some natural metabolic intermediates from the cells. Furthermore, in some microorganisms, transport of quorum-sensing factors is mediated by MDR transporters; thus, overexpression of the transporters can also disturb cell-to-cell communications. As a result, under normal conditions, cells keep MDR-transporter genes repressed and activate them only upon exposure to stresses. We speculate that exploiting limitations of the drug-efflux system is a promising strategy to counteract MDR in pathogenic fungi.

The association of stressful life events on weight loss efforts among African American breast cancer survivors

OBJECTIVE

This study examined whether stressful life events were associated with weight loss, central adiposity, and health behavior changes of African American breast cancer survivors (AABCS) participating in a weight loss intervention.

METHODS

We conducted a secondary-data analyses of Moving Forward, a weight loss efficacy trial for AABCS conducted in 2011-2014. Two-hundred forty-six eligible women were randomized to a 6-month interventionist-guided (IG) or self-guided (SG) weight loss intervention. Data was collected on height, weight, self-reported diet, and self-reported physical activity. Stress (e.g., financial, legal, employment, relationships, safety, prejudice) was measured using an abbreviated version of the Crisis in Family Systems (CRISYS) urban life stress measure. Generalized linear models stratified by group examined the degree to which stress was associated with weight loss or changes in central adiposity, physical activity, and diet during the intervention (Months 1-6) or maintenance (Months 7 to 12) phases.

RESULTS

Participants reported a median of 3.0 life stressors (range 0 to 22) mostly relating to relationships, safety concerns, and financial problems. In the IG group during the intervention phase, exposure to life stressors was not associated with weight loss (p = 0.15) or change in central adiposity (p = 0.69), physical activity (p = 0.15), or diet (p = 0.26). We found similar associations for the maintenance phase and in the SG group.

CONCLUSION/IMPLICATIONS

Despite facing stress across a myriad of domains (e.g., relationships, safety, finances), AABCS were successful at initiating and maintaining behaviors to achieve weight loss, reductions in central adiposity, and behavioral changes. Future randomized controlled trials are warranted that include more strategies to address the challenges that AABCS face, to determine whether AABCS in particular might benefit from interventions that address barriers (e.g., stress management) to weight loss. Such strategies are critical for improving quality of life and lowering the risk of cancer recurrence.

Melatonin application differentially modulates the enzymes associated with antioxidative machinery and ascorbate-glutathione cycle during arsenate exposure in indica rice varieties

Arsenic (As) contamination and accumulation in rice is a serious concern causing severe oxidative damage. Melatonin acts as a protective agent in plant defence against multiple abiotic stresses. The mechanism of antioxidant function of melatonin during As stress in rice genotypes is less studied. In this study, hydroponically-grown As-susceptible (Khitish) and As-tolerant (Muktashri) rice cultivars, subjected to 150 µm arsenate stress, were supplemented with exogenously applied melatonin (20 µm) to examine the plant defence mechanism. Melatonin (Mel) increased root and shoot length, fresh and dry weight, chlorophyll a and b content and activated reducing power and free radical scavenging capacity in both rice cultivars. The role of Mel in the sensitive variety appeared to be more prominent with respect to reduced water saturation deficit by reducing endogenous As and H₂ O₂ accumulation, and enhancing overall antioxidant capacity by imposing reduced requirement of catalase for ROS detoxification, and restoring As-inhibited activity of glutathione-S-transferase, glutathione peroxidase and dehydroascorbate reductase. In contrast, melatonin treatment in the tolerant cultivar required reduced involvement of ascorbate peroxidase to deal with As toxicity, and complemented the stress-mediated inhibition of guaiacol peroxidase activity. Isozyme profiling also established extensive varietal differences with regard to induction of new isoform(s) by Mel during As treatment. This study provides clear insights into mechanistic details of the regulation of antioxidative enzymes by melatonin in contrasting rice genotypes, which may prove helpful in generating As tolerance in susceptible rice varieties grown in marginalized soils, thereby improving crop yield and productivity.

A large outbreak of measles in the West Midlands, England, 2017-2018: descriptive epidemiology, control measures and lessons learnt

In November 2017, eight confirmed measles cases were reported to Public Health England from a hospital in the West Midlands. A multidisciplinary Incident Management Team (IMT) was established to determine the extent of the problem and coordinate an outbreak response. Between 1 November 2017 and 4 June 2018, a total of 116 confirmed and 21 likely measles cases were linked to this outbreak; just under half (43%) were aged over 15 years of age. Fifty-five of the confirmed cases were hospitalised (48%) and no deaths were reported. At the start of the outbreak, cases were mostly individuals of Romanian origin; the outbreak subsequently spread to the wider population. Over the 8-month response, the IMT conducted the following control measures: extensive contact tracing, immediate provision of post-exposure prophylaxis, community engagement amongst specific high-risk groups, MMR awareness raising including catch-up campaigns and enhanced vaccination services at selected GP surgeries. Key challenges to the effective control measures included language difficulties limiting community engagement; delays in diagnosis, notification and appropriate isolation of cases; limited resources for contact tracing across multiple high-risk settings (including GPs and hospitals) and lack of timely data on vaccine coverage in sub-groups of the population to guide public health action.

Obesity during the COVID-19 pandemic: both cause of high risk and potential effect of lockdown? A population-based electronic health record study

OBJECTIVES

Obesity is a modifiable risk factor for coronavirus disease 2019 (COVID-19)-related mortality. We estimated excess mortality in obesity, both 'direct', through infection, and 'indirect', through changes in health care, and also due to potential increasing obesity during lockdown.

STUDY DESIGN

The study design of this study is a retrospective cohort study and causal inference methods.

METHODS

In population-based electronic health records for 1,958,638 individuals in England, we estimated 1-year mortality risk ('direct' and 'indirect' effects) for obese individuals, incorporating (i) pre-COVID-19 risk by age, sex and comorbidities, (ii) population infection rate and (iii) relative impact on mortality (relative risk [RR]: 1.2, 1.5, 2.0 and 3.0). Using causal inference models, we estimated impact of change in body mass index (BMI) and physical activity during 3-month lockdown on 1-year incidence for high-risk conditions (cardiovascular diseases, diabetes, chronic obstructive pulmonary disease and chronic kidney disease), accounting for confounders.

RESULTS

For severely obese individuals (3.5% at baseline), at 10% population infection rate, we estimated direct impact of 240 and 479 excess deaths in England at RR 1.5 and 2.0, respectively, and indirect effect of 383-767 excess deaths, assuming 40% and 80% will be affected at RR = 1.2. Owing to BMI change during the lockdown, we estimated that 97,755 (5.4%: normal weight to overweight, 5.0%: overweight to obese and 1.3%: obese to severely obese) to 434,104 individuals (15%: normal weight to overweight, 15%: overweight to obese and 6%: obese to severely obese) would be at higher risk for COVID-19 over one year.

CONCLUSIONS

Prevention of obesity and promotion of physical activity are at least as important as physical isolation of severely obese individuals during the pandemic.

Non-equilibrium magnetic response of canonical spin glass and magnetic glass

Time and history dependent magnetization has been observed in a wide variety of materials, which are collectively termed as the glassy magnetic systems. However, such systems showing similar non-equilibrium magnetic response can be microscopically very different and they can be distinguished by carefully looking into the details of the observed metastable magnetic behavior. Canonical spin glass (SG) is the most well studied member of this class and has been extensively investigated both experimentally and theoretically over the last five decades. In canonical SGs, the low temperature magnetic state obtained by cooling across the SG transition temperature in presence of an applied magnetic field is known as the field cooled (FC) state. This FC state in canonical SG is widely believed as an equilibrium state arising out of a thermodynamic second order phase transition. Here, we show that the FC state in canonical SG is not really an equilibrium state of the system. We report careful dc magnetization and ac susceptibility measurements on two canonical SG systems, AuMn (1.8%) and AgMn (1.1%). The dc magnetization in the FC state shows clear temperature dependence. In addition, the magnetization shows a distinct thermal hysteresis in the temperature regime below the SG transition temperature. On the other hand, the temperature dependence of ac susceptibility has clear frequency dispersion below SG transition in the FC state prepared by cooling the sample in the presence of a dc-bias field. We further distinguish the metastable response of the FC state of canonical SG from the metastable response of the FC state in an entirely different class of glassy magnetic system namely magnetic glass, where the non-equilibrium behavior is associated with the kinetic-arrest of a first order magnetic phase transition.

Quantitative material analysis using secondary electron energy spectromicroscopy

This paper demonstrates how secondary electron energy spectroscopy (SEES) performed inside a scanning electron microscope (SEM) can be used to map sample atomic number and acquire bulk valence band density of states (DOS) information at low primary beam voltages. The technique uses an electron energy analyser attachment to detect small changes in the shape of the scattered secondary electron (SE) spectrum and extract out fine structure features from it. Close agreement between experimental and theoretical bulk valance band DOS distributions was obtained for six different test samples, where the normalised root mean square deviation ranged from 2.7 to 6.7%. High accuracy levels of this kind do not appear to have been reported before. The results presented in this paper point towards SEES becoming a quantitative material analysis companion tool for low voltage scanning electron microscopy (LVSEM) and providing new applications for Scanning Auger Microscopy (SAM) instruments.

Biochemical characterisation of carious dentine zones using Raman spectroscopy

OBJECTIVE

Carious tissue discrimination in clinical operative caries management relies traditionally on the subjective hardness of carious dentine. Biochemical alterations within the lesion have the potential to discriminate the lesion zones objectively. This study aimed to determine the correlation between the biochemical proportions of amide I and phosphate moieties as these are the most prominent peaks found in dentine with the Knoop microhardness of carious dentine zones, using non-contact Raman spectroscopy. The null hypothesis investigated was that there was no correlation between Raman peak ratios, amide I: phosphateν1, and the Knoop microhardness within specific zones of a carious lesion.

METHODS

423 scan points from 20 carious dentine lesion samples examined using high-resolution Raman spectroscopy. The peak ratio of the characteristic vibration mode of amide I (1650 cm^-1) and phosphate (960 cm^-1) bands were calculated, following a straight line path through the lesion to the pulp and correlated to corresponding Knoop microhardness measurements.

RESULTS

Using logistic regression analysis, clear correlations were found between the Knoop microhardness and Raman peak ratio cut-off values between caries-infected and caries-affected dentine (81.5 % sensitivity / 92.7 % specificity), with a lower specificity (2.7 %) found between caries-affected and sound dentine.

CONCLUSION

This study concluded that non-contact Raman spectroscopy can be used in vitro to discriminate objectively between the different zones of a carious dentine lesion at high resolution, using the Raman peak ratios, amide I : phosphate ν₁.

CLINICAL SIGNIFICANCE

Specific biochemical alterations have the potential to be used in-vitro and in-vivo to identify the end-point of selective carious lesion excavation.

An automated setup to measure the linear and nonlinear magnetic ac-susceptibility down to 4 K with higher accuracy

An automated stepper motor controlled ac-susceptibility setup has been developed to measure the phase resolved linear and nonlinear magnetic ac-susceptibilities of a material in the temperature range of 4 K-300 K with a frequency range of 0.1 Hz-1.5 kHz. A maximum dc-field of ±150 Oe can be superimposed with a maximum ac-field of 100 Oe in the same coil by using a homemade ac-dc superimposing circuit. The induced voltage in the detection coil is measured by a lock-in amplifier, and temperature is controlled by a temperature controller. The very common offset voltage drifting problem is resolved by implementing a two-point measurement technique at every temperature, field, and frequency using a stepper motor. Operation of the stepper motor is controlled by a homemade computer programmable driver circuit. Sensitivity of the setup is obtained around ∼10^-7 emu, and relative accuracy of the measurement is much better than 0.1%. Higher harmonics can be measured with a maximum noise level of ±15 nV throughout the temperature, field, and frequency range.

Lifetime risk of cardiovascular-renal disease in type 2 diabetes: a population-based study in 473399 individuals

Background

Lifetime risks of cardiovascular (CV) and renal diseases are high, particularly in type 2 diabetes (T2D), but rarely studied together, and relative disease contributions are unknown. Knowledge of lifetime risk of cardiovascular-renal disease (CVRD) will better reflect disease burden in T2D.

Purpose

To investigate the lifetime risks (LTRs) of composite and individual components of major adverse reno-cardiovascular events, MARCE in T2D patients.

Method

In a population-based cohort study using national electronic health records, we studied 473399 individuals aged 45–99 years with T2D in England 2007–2018. The LTR of composite and individual components of MARCE (including CV death and CVRD: heart failure, HF; chronic kidney disease stage 3 and above, CKD; myocardial infarction, MI; stroke or peripheral artery disease, PAD) were estimated. LTRs by baseline CVRD comorbidity status were compared with individuals free from CVRD at baseline, accounting for the competing risk of death.

Results

Among T2D patients aged ≥45 years, the LTR of MARCE was 80% for individuals free from CVRD at baseline. LTR of MARCE was 97%, 93%, 98%, 89% and 91% for individuals with specific CVRD comorbidities for HF, CKD, MI, stroke and PAD, respectively at baseline. Within the CVRD-free cohort, LTR of CKD was highest at 54%, followed by CV death (41%), HF (29%), stroke (20%), MI (19%) and PAD (9%). Compared to CVRD-free, HF, MI and CKD at baseline were associated with the highest LTR of MARCE and its component diseases (Table).

Conclusion

The lifetime risk of CV disease and CKD in T2D patients is estimated to be over 60% and 50% respectively (1–3). When considered together, the LTR of MARCE is 80% in CVRD-free T2D patients, while nearly all those with T2D and HF will develop MARCE over their lifetime. Of the individual components of MARCE, LTR of CKD and HF were the highest among CVRD-free T2D patients. Preventive measures in T2D patients should be a priority in clinical practice to mitigate the burden of these complications.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): AstraZeneca

92 aetiologic factors for heart failure: prevalence, co-occurrence, prognosis and potential for prevention in 170,885 incident HF cases

Background

ESC and AHA guidelines identify 92 putative aetiological factors for heart failure, but primary prevention strategies for heart failure (HF) have had limited success. There are no previous studies systematically evaluating the potential for prevention among such a wide range of clinically manifest aetiologic factors.

Objective

To estimate for 92 (putative) aetiologic factors their prevalence, co-occurrence, preventability and impact on HF prognosis in incident HF.

Methods

We identified 170885 individuals aged ≥30 years with incident HF from 1997–2017 using linked primary and secondary care electronic health records (EHR) in the UK (CALIBER). For each of the 92 factors we developed EHR phenotypes using ICD-10 diagnosis, Read, procedure and medication codes (total = 5961 codes). We conducted a literature review of trials of primary HF prevention across 92 factors.

Results

35.6% of individuals with HF had ≥4 aetiologic factors recorded in the preceding 5 years. Of all new HF cases 71.5% had ≥1 of the 7 aetiologic factors with trial evidence of effective preventive therapy for HF; 12.9% had ≥1 aetiologic factor with effective preventive therapy for CVD and 15.6% had either no aetiological factor, or an aetiological factor with no evidence of preventive potential. 88/91 factors were represented. The commonest factors in the 5 years prior to HF diagnosis were hypertension (48.7%), smoking (46.6%), reduced physical activity (39.6%), stable angina (35.6%), obesity (29.4%), atrial arrhythmias (17.3%), unstable angina (16.9%), cancer (16.6%), myocardial infarction (15.9%), diabetes (15.2%), alcohol (14.9%) and severe anaemia (14.3%). Mortality at 1 year varied across all 91 factors (lowest: pregnancy-related hormonal disorder – 4.2%; highest: phaeochromocytoma – 73.7%).

Conclusion

We provide a systematic map of primary preventive opportunities for heart failure, demonstrate the high burden of co-occurring aetiologic factors and highlight need for trials tackling multiple aetiological factors.

Aetiologic factors of heart failure

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): Innovative Medicines Initiative-2 Joint Undertaking

Multi-drug resistant, biofilm-producing high-risk clonal lineage of Klebsiella in companion and household animals

Antimicrobial resistance is a global emergency which needs one health approach to address. The present study was conducted to detect the prevalence of beta-lactamase and biofilm-producing Klebsiella strains in rectal swabs (n = 624) collected from healthy dogs, cats, sheep and goats reared as companion or household animals in India. The dogs and cats were frequently exposed to third- or fourth-generation cephalosporins for therapy. The sheep and goats were occasionally exposed to antibiotics and had environmental exposure. Phenotypical ESBL (n = 93) and ACBL (n = 88)-producing Klebsiella were isolated significantly more (P < 0·05) from companion animals than household animals. Majority of the Klebsiella possessed bla_CTX-M-15 . The sequences bla_CTX-M-15.2 , bla_CTX-M-197 and bla_CTX-M-225 are reported first time from the companion animals. All ACBL-producing isolates possessed bla_AmpC . The present study detected 65·8% of Klebsiella strains as biofilm producers possessing the studied biofilm associated genes. The isolates showed phenotypical resistance against chloramphenicol, tetracycline, doxycycline, co-trimoxazole, ampicillin, cefotaxime/clavulanic acid. The present study showed that companion and household animals (dogs, cats, sheep, goats) may act as a carrier of ESBL/biofilm-producing, multi-drug resistant, high-risk clonal lineage of Klebsiella.

Comparison of Standard Conservative Treatment and Early Initiation of Renal Replacement Therapy in Pregnancy-related Acute Kidney Injury: A Single-center Prospective Study

INTRODUCTION AND OBJECTIVE

Pregnancy-related acute kidney injury (PRAKI) is one of the most important cause of maternal and fetal morbidity and mortality. Some of the reasons behind PRAKI may be due to sepsis, postpartum hemorrhage, preeclampsia, thrombotic microangiopathies (TMA), and acute fatty liver of pregnancy (AFLP). The timing of initiation of renal replacement therapy (RRT) for better patient outcome is still debatable. We conducted this study to establish whether earlier initiation of RRT in PRAKI improves fetomaternal survival compared to a more conservative approach.

MATERIALS AND METHODS

This is a prospective study, where patients were screened at a multispecialty tertiary care hospital in north India for 1 year. The patients were divided into two groups: early RRT and standard AKI treatment. The demographic profile and clinical characteristics of the patients in terms of age, parity access to antenatal care, fetal outcome, urine output, hematological and biochemical profiles, RRT, duration of hospitalization, recovery of renal function, and patients survival were recorded.

RESULTS

This prospective study conducted included 13 patients in the early RRT group and 23 patients in the standard group. Considering the fetal outcome, the number of fetal deaths in early RRT group were 14.29%, whereas for the standard group it was 85.71%. In all, 75% of early RRT group and 25% of standard group had normal term delivery. Probability test applied showed they were statistically significant. One maternal mortality was there in the standard group. The indices of maternal outcome in PRAKI patients were found to be statistically insignificant.

CONCLUSION

The planning of RRT whether early or late does not make a difference in maternal mortality or morbidity. The fetal outcome is significantly better for patients with early RRT than conservative treatment in PRAKI.

HOW TO CITE THIS ARTICLE

Banerjee A, Mehrotra G. Comparison of Standard Conservative Treatment and Early Initiation of Renal Replacement Therapy in Pregnancy-related Acute Kidney Injury: A Single-center Prospective Study. Indian J Crit Care Med 2020;24(8):688-694.

Nature of Magnetic Excitations in the High-Field Phase of α-RuCl_{3}

We present comprehensive electron spin resonance (ESR) studies of in-plane oriented single crystals of α-RuCl_{3}, a quasi-two-dimensional material with honeycomb structure, focusing on its high-field spin dynamics. The measurements were performed in magnetic fields up to 16 T, applied along the [110] and [100] directions. Several ESR modes were detected. Combining our findings with recent inelastic neutron- and Raman-scattering data, we identified most of the observed excitations. Most importantly, we show that the low-temperature ESR response beyond the boundary of the magnetically ordered region is dominated by single- and two-particle processes with magnons as elementary excitations. The peculiarities of the excitation spectrum in the vicinity of the critical field are discussed.

Giant electron-phonon coupling of the breathing plane oxygen phonons in the dynamic stripe phase of [Formula: see text]

Doped antiferromagnets host a vast array of physical properties and learning how to control them is one of the biggest challenges of condensed matter physics. [Formula: see text] (LSNO) is a classic example of such a material. At low temperatures holes introduced via substitution of La by Sr segregate into lines to form boundaries between magnetically ordered domains in the form of stripes. The stripes become dynamic at high temperatures, but LSNO remains insulating presumably because an interplay between magnetic correlations and electron-phonon coupling localizes charge carriers. Magnetic degrees of freedom have been extensively investigated in this system, but phonons are almost completely unexplored. We searched for electron-phonon anomalies in LSNO by inelastic neutron scattering. Giant renormalization of plane Ni-O bond-stretching modes that modulate the volume around Ni appears on entering the dynamic charge stripe phase. Other phonons are a lot less sensitive to stripe melting. Dramatic overdamping of the breathing modes indicates that dynamic stripe phase may host small polarons. We argue that this feature sets electron-phonon coupling in nickelates apart from that in cuprates where breathing phonons are not overdamped and point out remarkable similarities with the colossal magnetoresistance manganites.