Heterotaxy pattern associated with sinus node dysfunction in an adult: A case report

Key Clinical Message

A 26-year-old male patient admitted to the hospital ward with experience of repetitive syncopes for a year. The patient was diagnosed with sick sinus syndrome. The aim of this clinical report is to highlight the variability of anatomical findings associated with polysplenia pattern.

Abstract

This case report presents a 26-year-old male patient who presented to the medical ward with a complaint of repeating blackouts for a year. The patient was then diagnosed with sick sinus syndrome, and further investigations revealed left isomerism, polysplenia, and no congenital heart defects. Holter monitoring, ultrasonography, electrocardiography, and computed tomography were used to confirm the diagnosis. The patient underwent DDDR pacemaker implantation for the treatment of SA node dysfunction. The report highlights the variability of anatomical findings associated with polysplenia pattern and the various types of heartbeat disruptions that may occur in the atrial appendages of the left side isomerism.

Ventricular Septal Rupture Management in Patients With Acute Myocardial Infarction: A Review

Untreated myocardial infarction (MI) can potentially lead to many fatal complications which require immediate management. One of them is ventricular septal rupture (VSR) which necessitates the hemodynamic stabilization and closure of the septal rupture. Conventional treatment strategy involves surgical repair; however, percutaneous transcatheter repair using an occluder device is a promising upcoming approach. We conducted a detailed review of various published articles and examined the trends in incidence, risk factors, and pathophysiology of MI leading to VSR followed by an in-depth analysis of the various management strategies for the same. In the current clinical scenario, thrombolysis is an imperative management strategy that has been shown to decrease the occurrence of VSR by manifolds, more specifically in patients having ST-elevated MI. Delayed surgical closure remains the main treatment for post-infarction VSR. Other newer modalities, such as percutaneous closure devices and mechanical circulatory supports, are attractive alternative or complementary strategies to treat such patients, both postoperatively and perioperatively. However, earlier surgical repair in VSR increases the risk of mortality, and the optimal timing for VSR closure remains controversial. Despite surgical closure of VSR being the traditional treatment, it presents a considerably high operative risk. Although newer interventions such as percutaneous closure devices and mechanical circulatory supports provide impressive outcomes, their efficacy in high-risk patients remains inconclusive.

A Comparative Review of Vagal Nerve Stimulation Versus Baroreceptor Activation Therapy in Cardiac Diseases

Sympathetic imbalance coupled with impairment of baroreceptor control is a key factor responsible for hemodynamic abnormalities in congestive heart failure. Vagal nerve stimulation (VNS) and baroreceptor activation therapy (BAT) are two novel interventions for the same. In this paper, we review the role of sympathovagal alterations in cardiac diseases like heart failure, arrhythmia, hypertension (HTN), etc. Studies like neural cardiac therapy for heart failure (NECTAR-HF), autonomic regulation therapy to enhance myocardial function and reduce progression of heart failure (ANTHEM-HF), and baroreflex activation therapy for heart failure (BEAT-HF), which comprise the history, efficacy, limitations, and current protocols, were extensively analyzed in contrast to one another. Vagal nerve stimulation reverses the reflex inhibition of cardiac vagal efferent activity, which is caused as a result of sympathetic overdrive during the course for heart failure. It has shown encouraging results in certain pre-clinical studies; however, there is also a possibility of serious cardiovascular adverse events if given in higher than the recommended dosage. Attenuated baroreflex sensitivity is attributed to cardiac arrhythmogenesis during heart failure. Baroreceptor activation therapy reverses this phenomenon. However, the surgical procedure for baroreceptor stimulation can have unwarranted complications, including worsening heart failure and hypertension. Considering the effectiveness of the given modalities and taking into account the inconclusive evidence of their adverse events, more clinical trials are needed for establishing the future prospects of these interventional approaches.

Ultrafiltration in Heart Failure: A Review

Ultrafiltration is an effective method to get rid of fluid retention and congestion in patients with acute decompensated heart failure (HF) without affecting the circulating volume. Although its efficacy in comparison to diuretics is debatable, the evaluation of our analysis is based on various studies that comprise published clinical trials on ultrafiltration and studies comparing the efficacy of diuretics and ultrafiltration. Apart from this, we also look at literature that provides shortcomings of the said procedure and its scope for future advancements. Heart failure ultimately leads to volume overload, which is a highly concerning complication. Diuretics have been used as a first-line treatment for fluid overload but are becoming inefficacious due to the development of resistance and renal dysfunction. Ultrafiltration, on the other hand, is an attractive alternative to counter volume overload and congestion, which are unresponsive to medical therapy. There is also evidence that it significantly decreases the probability of future episodes of decompensation. There are, however, disagreements about whether ultrafiltration is an effective method to improve mortality in these patients. There is a lack of conclusive studies demonstrating the superiority of one fluid removal method over another. Hence, it is imperative to continue searching for the most effective method to treat congestion. Priority should be given to more mechanistic studies regarding ultrafiltration.

Identification and Characterization of Aluminium Tolerant Bacteria Isolated from Soil Contaminated by Electroplating and Automobile Waste

Due to anthropogenic activities and the advancement of industries, metal contamination is growing globally. Aluminum toxicity is seriously endangering plants, animals, and humans by rapidly rising in soil and water. Even though some fungi can tolerate aluminum, researchers are interested in finding bacteria that are resistant to aluminum. The current state of knowledge on bacteria resistant to aluminum is extremely limited. In the present study, bacterial isolates from soil near a metal electroplating and automobile industry in Punjab, India, were isolated and then screened for high aluminum metal tolerance. The aluminum tolerant bacterial isolate was identified as Cedecea davisae M1, a member of the Enterobacteriaceae family, using morphological, biochemical, and 16srRNA gene sequence analyses. The spectroscopic results indicate that the strain may tolerate up to 150 ppm of aluminum. Antibiotic resistance of Cedecea davisae M1 was determined using disks on Luria agar plates, and the bacteria were found to be resistant to vancomycin, ampicillin, carbenicillin, and rifampicin. The findings of the study indicated that the strain might be able to remove aluminum toxicity from the environment, which needs to be further explored.

Racial Disparity Between the Post-Procedural Outcomes Among Patients With Peripheral Artery Disease: A Systematic Review and Meta-analysis

The Racial disparity between the clinical outcomes post interventions among Peripheral Artery Disease (PAD) have not been well studied, with limited literature available. We conducted a meta-analysis to evaluate the post-procedure outcomes among PAD patients between Black and White race. We systematically searched all electronic databases from inception until first November 2022. The primary endpoint was major amputation within 30 days. Secondary endpoints were myocardial infarction (MI) within 30 days, mortality within 30 days, and all-cause mortality (ACM). A total of 136,395 patients were included in the analysis, with 117,177 patients of the White race and 19,218 patients of the Black race. The mean age of the patients in each group was (66.41 vs 62.75). Most common comorbidity among White and Black patients was diabetes mellitus (42.15% vs 55.90%), and hypertension (HTN) (39.53% vs 90.07%). The odds of major amputation within 30 days was significantly higher in Black patients compared to white patients (OR, 0.40 (95% CI: 0.19-0.84, P = 0.02), while the odds of MI was higher in White patients compared to Black race PAD patients (OR, 1.29, (95%CI:1.05-1.58), P < 0.02). There was no significant difference in ACM (OR, 0.97(95%CI: 0.64-1.47, P = 0.88), and mortality within 30 days (OR, 1.09(95%CI:0.77-1.53, P = 0.64) between both groups. To our knowledge, this is the first meta-analysis with the largest sample size thus far, highlighting that Black patients are at a higher risk for major amputation within 30 days compared to white patients although mortality remains comparable between the 2 races.

Easy route to functionalize iron oxide nanoparticles via long-term stable thiol groups

The functionalization of superparamagnetic iron oxide nanoparticles (SPIOs) by meso-2,3-dimercaptosuccinic acid (DMSA) was investigated. Under ambient conditions, the thiol groups from DMSA are not stable and do not allow a direct functionalization without storage in stringent conditions or a chemical regeneration of free thiols. In this study, we have developed a protocol based on poly(ethylene glycol) (PEG) grafting of SPIO prior to DMSA anchoring. We have observed that PEG helps to increase the stability of thiol groups under ambient conditions. The thiol functionalized SPIOs were stable under physiological pH and ionic strength as determined by Ellman's essay and allowed us to graft a thiol reactive fluorescent dye: tetramethylrhodamine-5-maleimide (TMRM).

Anemia prophylaxis in adolescent school girls by weekly or daily iron-folate supplementation

OBJECTIVE

To examine the benefits of anemia prophylaxis in adolescent school.girls by weekly or daily iron-folate supplementation.

DESIGN

Prospective study.

SETTING

Government girl schools of northeast Delhi.

SUBJECTS

2088 subjects (with hemoglobin greater than 7.9 g/dL), including 702 on daily and 695 on weekly iron-folate administration; 691 girls served as controls.

RESULTS

About 85% girls were iron deficient out of which 49.3% were anemic. Weekly administration took longer time to raise hemoglobin but was effective as well as practical. Plasma ferritin estimation in girls showed rise in level in both the treated groups.

CONCLUSION

Weekly administration of iron-folate was a practical and effective strategy for anemia prophylaxis in adolescent school girls.

Expression and purification of Dengue virus type 2 envelope protein as a fusion with hepatitis B surface antigen in Pichia pastoris

The methylotrophic yeast, Pichia pastoris, has been used as a host to express the envelope protein (Den2E) of dengue type 2 virus (NGC strain) as a chimera with hepatitis B surface antigen (HBsAg): a protein known to self assemble into virus-like particles (VLPs) and to be efficiently expressed in P. pastoris. The Den2E gene used in this study is a truncated version encoding the first 395 amino acid (aa) residues of the mature Den2E protein; the HBsAg gene encodes the full length 226 aa HBsAg protein. Two in-frame gene fusions were constructed for intracellular expression in P. pastoris. The first one contains the HBsAg gene as the 5' partner and the Den2E gene as the 3'partner (HBsAg-Den2E). In the second one, the relative positions of the two partners of the gene fusion were reversed to create the hybrid Den2E-HBsAg gene. These fusion genes were integrated into the genome of P. pastoris under the control of the methanol-inducible alcohol oxidase (AOX1) promoter. Of the two fusions, the Den2E-HBsAg gene was expressed at higher levels in P. pastoris based on Northern analysis. The hybrid protein ( approximately 68 kDa) expressed by this clone was purified to near homogeneity using a combination of acid precipitation, hydrophobic interaction, and immunoaffinity chromatographic steps. Final purification achieved was approximately 1400-fold with a yield of approximately 26%. The chimeric protein was found to possess the ability to assemble into high molecular weight aggregates (akin to HBsAg particles). The recombinant fusion protein eluted close to the void volume of a Sepharose CL-4B column indicating its macromolecular nature. On a CsCl density gradient the recombinant fusion protein sedimented to a position very similar to that of HBsAg VLPs. The hybrid protein is recognized by the two neutralizing monoclonals against the two components of the chimeric protein.

Mechanism of malarial haem detoxification inhibition by chloroquine

The haem detoxification pathway of the malaria parasite Plasmodium falciparum is a potential biochemical target for drug development. Free haem, released after haemoglobin degradation, is polymerized by the parasite to form haemozoin pigment. Plasmodium falciparum histidine-rich protein-2 (Pfhrp-2) has been implicated as the catalytic scaffold for detoxification of haem in the malaria parasite. Previously we have shown that a hexapeptide repeat sequence (Ala-His-His-Ala-Ala-Asp), which appears 33 times in Pfhrp-2, may be the major haem binding site in this protein. The haem binding studies carried out by ourselves indicate that up to 18 equivalents of haem could be bound by this protein with an observed K(d) of 0.94 microM. Absorbance spectroscopy provides evidence that chloroquine is capable of extracting haem bound to Pfhrp-2. This was supported by the K(d) value, of 37 nM, observed for the haem-chloroquine complex. The native PAGE studies reveal that the formation of the haem-Pfhrp-2 complex is disrupted by chloroquine. These results indicate that chloroquine may be acting by inhibiting haem detoxification/binding to Pfhrp-2. Moreover, the higher affinity of chloroquine for haem than Pfhrp-2 suggests a possible mechanism of action for chloroquine; it may remove the haem bound to Pfhrp-2 and form a complex that is toxic to the parasite.