Safety and efficacy of clot-dissolving therapies for submassive pulmonary embolism: A network meta-analysis of randomized controlled trials

BACKGROUND

Acute pulmonary embolism (PE) is a serious condition that needs quick and effective treatment. Anticoagulation therapy is the usual care for most PE patients but may not work well for higher-risk ones. Thrombolysis breaks the clot and improves blood flow. It can be given systemically or locally. Ultrasound-assisted catheter-directed thrombolysis (USAT) is a new technique that boosts clot-busting drugs. This network meta-analysis compares death, bleeding, and benefits of four treatments in acute submassive PE.

METHODS

We comprehensively searched relevant databases up to July 2023 for RCTs. The outcomes encompassed all-cause mortality, major and minor bleeding, PE recurrence, and hospital stay duration. Bayesian network meta-analysis computed odds ratios (OR) and 95 % CI estimates.

RESULTS

In this network meta-analysis of 23 RCTs involving 2521 PE patients, we found that SCDT had the most favorable performance for mortality, as it had the lowest odds ratio (OR) among the four interventions (OR 5.41e-42; 95 % CI, 5.68e-97, 1.37e-07). USAT had the worst performance for major bleeding, as it had the highest OR among the four interventions (OR 4.73e+04; 95 % CI, 1.65, 9.16e+13). SCDT also had the best performance for minor bleeding, as it had the lowest OR among the four interventions (OR 5.68e-11; 95 % CI, 4.97e-25, 0.386).

CONCLUSION

Our meta-analysis suggests that SCDT is the most effective treatment intervention in improving the risks of All-cause mortality and bleeding. Thrombolytic therapy helps in improving endpoints including the risk of PE recurrence and the duration of hospital stay.

Coronary Artery Dissection and Myocarditis Caused by Eosinophilic Granulomatosis with Polyangiitis (EGPA): A Case Report

Eosinophilic granulomatosis with polyangiitis (EGPA) also referred to as Churg-Strauss syndrome is a rare vasculitis of the small to medium vessels. We present a rare case of acute coronary artery dissection brought on by EGPA, which generally has a poor prognosis. A 41-year-old male with history of bronchial asthma presented to the emergency room with a 2-week history of dyspnea, cough with clear phlegm, and fever. For the past eight months he had experienced episodes with similar symptoms relieved by steroids. CT chest showed bilateral upper lobe patchy opacities with extensive workup for infectious etiology being negative. He had peripheral eosinophilia with sinusitis. He had acute coronary syndrome and Coronary angiogram showed Right coronary artery dissection. After making a diagnosis of EGPA based on American college of Rheumatology criteria, he was successfully treated with high dose immunosuppression. Coronary artery dissection is a fatal and uncommon complication of EGPA which is usually diagnosed postmortem. Early recognition of this condition ante mortem and aggressive treatment can be lifesaving as demonstrated in our case.

Sodium-glucose cotransporter-2 inhibitor-associated euglycemic diabetic ketoacidosis in COVID-19-infected patients: A systematic review of case reports

BACKGROUND

Diabetic ketoacidosis (DKA) manifests as hyperglycemia, metabolic acidosis, and ketosis. However, euglycemic DKA (eu-DKA) conceals severe DKA with glucose levels below 200 mg/dL. Sodium-glucose cotransporter-2 (SGLT2) inhibitors can induce eu-DKA in diabetic patients. Notably, coronavirus disease 2019 (COVID-19) -infected individuals with diabetes using SGLT2 inhibitors face an augmented risk of eu-DKA due to the direct toxic impact of the virus on pancreatic islets. This study aims to comprehensively investigate the association between SGLT2 inhibitors and eu-DKA in COVID-19 patients through meticulous case report analysis. Additionally, we endeavor to examine the outcomes and treatment approaches for COVID-19-infected diabetics receiving SGLT2 inhibitors, providing indispensable insights for healthcare professionals managing this specific patient population.

AIM

To investigate the connection between SGLT2 inhibitors and euglycemic DKA in COVID-19 patients through a meticulous analysis of case reports.

METHODS

We conducted an exhaustive search across prominent electronic databases, including PubMed, SCOPUS, Web of Science, and Google Scholar. This search encompassed the period from December 2019 to May 2022, incorporating published studies and pre-prints. The search terms employed encompassed "SGLT2 inhibitors", "euglycemic DKA", "COVID-19", and related variations. By incorporating these diverse sources, our objective was to ensure a thorough exploration of the existing literature on this subject, thereby augmenting the validity and robustness of our findings.

RESULTS

Our search yielded a total of seven case reports and one case series, collectively comprising a cohort of twelve patients. These reports detailed instances of eu-DKA in individuals with COVID-19. Crucially, all twelve patients were utilizing SGLT2 as their primary anti-diabetic medication. Upon admission, all oral medications were promptly discontinued, and the patients were initiated on intravenous insulin therapy to effectively manage the DKA. Encouragingly, eleven patients demonstrated a favorable outcome, while regrettably, one patient succumbed to the condition. Subsequently, SGLT2 were discontinued for all patients upon their discharge from the hospital. These findings provide valuable insights into the clinical management and outcomes of eu-DKA cases associated with COVID-19 and SGLT2, underscoring the critical importance of prompt intervention and vigilant medication adjustments.

CONCLUSION

Our study sheds light on the possibility of diabetic patients developing both drug-related and unrelated DKA, as well as encountering adverse outcomes in the context of COVID-19, despite maintaining satisfactory glycemic control. The relationship between glycemic control and clinical outcomes in COVID-19 remains ambiguous. Consequently, this systematic review proposes that COVID-19-infected diabetic patients using SGLT2 should contemplate alternative treatment protocols until their recovery from the disease.

COVID-19-associated MRSA infective endocarditis and mitral valve perforation: a case report

BACKGROUND

Coronavirus disease 2019 (COVID-19) has emerged as a global pandemic, leading to significant morbidity and mortality. The interplay between COVID-19 and other medical conditions can complicate diagnosis and management, necessitating further exploration.

CASE PRESENTATION

This case report presents a patient with COVID-19 who developed infective endocarditis (IE) and mitral valve perforation caused by methicillin-resistant Staphylococcus aureus on a native mitral valve. Notably, the patient did not exhibit typical IE risk factors, such as intravenous drug use. However, he did possess risk factors for bacteremia, including a history of diabetes mellitus and recent steroid use due to the COVID-19 infection. The diagnosis of IE was crucially facilitated by transesophageal echocardiography.

CONCLUSIONS

This case highlights the potential association between COVID-19 and the development of infective endocarditis. Prompt evaluation using transesophageal echocardiography is vital when there is a high suspicion of IE in COVID-19 patients. Further research is required to elucidate the precise relationship between COVID-19 and IE.

Effect of fibrinolytic therapy on ST-elevation myocardial infarction clinical outcomes during the COVID-19 pandemic: A systematic review and meta-analysis

BACKGROUND

ST-elevation myocardial infarction (STEMI) is the result of transmural ischemia of the myocardium and is associated with a high mortality rate. Primary percutaneous coronary intervention (PPCI) is the recommended first-line treatment strategy for patients with STEMI. The timely delivery of PPCI became extremely challenging for STEMI patients during the coronavirus disease 2019 (COVID-19) pandemic, leading to a projected steep rise in mortality. These delays were overcome by the shift from first-line therapy and the development of modern fibrinolytic-based reperfusion. It is unclear whether fibrinolytic-based reperfusion therapy is effective in improving STEMI endpoints.

AIM

To determine the incidence of fibrinolytic therapy during the COVID-19 pandemic and its effects on STEMI clinical outcomes.

METHODS

PubMed, Google Scholar, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were queried from January 2020 up to February 2022 to identify studies investigating the effect of fibrinolytic therapy on the prognostic outcome of STEMI patients during the pandemic. Primary outcomes were the incidence of fibrinolysis and the risk of all-cause mortality. Data were meta-analyzed using the random effects model to derive odds ratios (OR) and 95% confidence intervals. Quality assessment was carried out using the Newcastle-Ottawa scale.

RESULTS

Fourteen studies including 50136 STEMI patients (n = 15142 in the pandemic arm; n = 34994 in the pre-pandemic arm) were included. The mean age was 61 years; 79% were male, 27% had type 2 diabetes, and 47% were smokers. Compared with the pre-pandemic period, there was a significantly increased overall incidence of fibrinolysis during the pandemic period [OR: 1.80 (1.18 to 2.75); I²= 78%; P = 0.00; GRADE: Very low]. The incidence of fibrinolysis was not associated with the risk of all-cause mortality in any setting. The countries with a low-and middle-income status reported a higher incidence of fibrinolysis [OR: 5.16 (2.18 to 12.22); I² = 81%; P = 0.00; GRADE: Very low] and an increased risk of all-cause mortality in STEMI patients [OR: 1.16 (1.03 to 1.30); I² = 0%; P = 0.01; GRADE: Very low]. Meta-regression analysis showed a positive correlation of hyperlipidemia (P = 0.001) and hypertension (P < 0.001) with all-cause mortality.

CONCLUSION

There is an increased incidence of fibrinolysis during the pandemic period, but it has no effect on the risk of all-cause mortality. The low- and middle-income status has a significant impact on the all-cause mortality rate and the incidence of fibrinolysis.

MINOCA mimic: Type 2 myocardial infarction due to severe aortic stenosis complicated by cardiogenic shock

Acute myocardial infarction without significant obstructive coronary disease presents a challenging clinical entity that requires timely intervention. The term myocardial infarction with nonobstructive coronary arteries (MINOCA) describes a working diagnosis attributed to varying etiologies in patients with a presumed ischemic cardiac condition. Several overlapping etiologies can be classified as type 2 myocardial infarction (MI). The 2019 AHA statement established diagnostic criteria and clarified the associated confusion, aiding in appropriate diagnosis. In this report, we present a case of demand-ischemia MINOCA and cardiogenic shock in a patient with severe aortic stenosis (AS).

Pseudomonas infection reduction in the ICU: a successful multidisciplinary quality improvement project

Pseudomonas aeruginosa infection causes high morbidity and mortality, especially in immunocompromised patients. Pseudomonas can develop multidrug resistance. As a result, it can cause serious outbreaks in hospital and intensive care unit (ICU) settings, increasing both length of stay and costs. In the second quarter of 2020, in a community hospital's 15-bed ICU, the P. aeruginosa-positive sputum culture rate was unacceptably high, with a trend of increasing prevalence over the previous 3 quarters. We performed a multidisciplinary quality improvement (QI) initiative to decrease the P. aeruginosa-positive rate in our ICU. We used the Define, Measure, Analyze, Improve, and Control model of Lean Six Sigma for our QI initiative to decrease the P. aeruginosa-positive sputum culture rate by 50% over the following year without affecting the baseline environmental services cleaning time. A Plan-Do-Study-Act approach was used for key interventions, which included use of sterile water for nasogastric and orogastric tubes, adherence to procedure for inline tubing and canister exchanges, replacement of faucet aerators, addition of hopper covers, and periodic water testing. We analyzed and compared positive sputum culture rates quarterly from pre-intervention to post-intervention. The initial P. aeruginosa-positive culture rate of 10.98 infections per 1,000 patient-days in a baseline sample of 820 patients decreased to 3.44 and 2.72 per 1,000 patient-days in the following 2 post-intervention measurements. Environmental services cleaning time remained stable at 34 minutes. Multiple steps involving all stakeholders were implemented to maintain this progress. A combination of multidisciplinary efforts and QI methods was able to prevent a possible ICU P. aeruginosa outbreak.

Intensive care unit adaptations in the COVID-19 pandemic: Lessons learned

The coronavirus disease 2019 pandemic had deleterious effects on the healthcare systems around the world. To increase intensive care units (ICUs) bed capacities, multiple adaptations had to be made to increase surge capacity. In this editorial, we demonstrate the changes made by an ICU of a midwest community hospital in the United States. These changes included moving patients that used to be managed in the ICU to progressive care units, such as patients requiring non-invasive ventilation and high flow nasal cannula, ST-elevation myocardial infarction patients, and post-neurosurgery patients. Additionally, newer tactics were applied to the processes of assessing oxygen supply and demand, patient care rounds, and post-ICU monitoring.

Overlap of diabetic ketoacidosis and hyperosmolar hyperglycemic state

Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemia state (HHS) are two life-threatening metabolic complications of diabetes that significantly increase mortality and morbidity. Despite major advances, reaching a uniform consensus regarding the diagnostic criteria and treatment of both conditions has been challenging. A significant overlap between these two extremes of the hyperglycemic crisis spectrum poses an additional hurdle. It has well been noted that a complete biochemical and clinical patient evaluation with timely diagnosis and treatment is vital for symptom resolution. Worldwide, there is a lack of large-scale studies that help define how hyperglycemic crises should be managed. This article will provide a comprehensive review of the pathophysiology, diagnosis, and management of DKA-HHS overlap.

Ketosis-prone diabetes mellitus: A phenotype that hospitalists need to understand

Diabetes has been classified mainly into types 1 and 2. Some type 2 diabetes patients, when developing ketosis, have been labeled as having atypical diabetes. Lately, syndromes of ketosis-prone diabetes, primarily in patients who we previously classified as type 2 diabetics, have emerged, and calls are being made to even reclassify diabetes. This mini-review will extensively deal with the historical, molecular, phenotypical, and clinical basis of why ketosis-prone diabetes is different than the traditional principles of type 1 and 2 diabetes and should be classified as such. Clinicians, especially those who are not diabetologists or endocrinologists, as well as hospitalists, intensivists, and primary care providers, will greatly benefit from this review.

Role of octreotide in small bowel bleeding

Gastrointestinal bleeding accounts for a drastic negative impact on the quality of the patients’ lives as it requires multiple diagnostic and therapeutic interventions to identify the source of the bleeding. Small bowel bleeding is the least common cause of gastrointestinal bleeding. However, it is responsible for the majority of complaints from patients with persisting or recurring bleeding where the primary source of bleeding cannot be identified despite investigation. A somatostatin analog known as octreotide is among the medical treatment modalities currently used to manage small bowel bleeding. This medication helps control symptoms of gastrointestinal bleeding by augmenting platelet aggregation, decreasing splanchnic blood flow, and antagonizing angiogenesis. In this review article, we will highlight the clinical efficacy of octreotide in small bowel bleeding and its subsequent effect on morbidity and mortality.

A Case of Adult Multisystem Inflammatory Syndrome Following COVID-19 Vaccine

Multisystem inflammatory syndrome is a life-threatening condition associated with elevated inflammatory markers and multiple organ injury. A diagnosis of exclusion, it has been reported after severe acute respiratory syndrome coronavirus 2 infection (SARS-CoV-2) in children and adults; recently it has been described in some post-COVID-19 vaccinated individuals. The prognosis with supportive care and immunomodulatory therapy is good, although some individuals may require treatment in the intensive care unit (ICU). Here we report a case of a 58-year-old man who developed multi-organ failure after receiving the second dose of the Moderna mRNA-1273 COVID-19 vaccine. He required critical organ support in the ICU. An extensive workup was done to rule out alternative infectious and inflammatory processes. Following a period of gradual in-hospital convalescence, our patient made a full recovery. To our knowledge, this is the first comprehensively described case of multisystem inflammatory syndrome associated with Moderna mRNA-1273 COVID-19 vaccine in an adult over 50 years of age.

Is There a Bias Toward Unvaccinated COVID-19 Patients?

Description With more than 22% of the United States still not vaccinated for COVID-19, we are trying to shed some light on whether there is any bias when treating unvaccinated COVID-19 patients. We highlight several reports where some individuals or organizations displayed possible bias, whether implicit or explicit. We examine the legal and ethical implications of these biases and offer a general overview of how to tackle them.

SGLT-2 Inhibitor-Associated Euglycemic Diabetic Ketoacidosis: A Case Report and a Literature Review

Diabetic ketoacidosis (DKA) is considered a medical emergency, most commonly associated with type 1 diabetes mellitus, and is relatively rare in type 2 diabetes mellitus (T2DM). We discuss a case of a 45-year-old woman with T2DM who presented to the emergency room with worsening lethargy and weakness. Before her presentation, her physician had recently added empagliflozin, a sodium-glucose cotransporter-2 (SGLT-2) inhibitor, to her anti-diabetic drug regimen along with glimepiride and a combination drug of vildagliptin and metformin. Based on the clinical examination and lab findings, DKA was suspected, but her glucose level was below the cutoff value for DKA diagnosis. However, her lab results showed significant metabolic acidosis and ketonemia with no clinical or laboratory features of sepsis. Therefore, the diagnosis of euglycemic diabetic ketoacidosis (eu-DKA) was made. She was successfully treated according to the DKA protocol and discharged in good condition. In this report, our aim is to discuss the relationship between SGLT-2 inhibitors with eu-DKA. Given the absence of significant hyperglycemia, recognition of this entity by clinicians may be delayed. Serum ketones should be obtained in diabetic patients with symptoms of nausea, vomiting, or malaise while taking SGLT-2 inhibitors, and SGLT-2 inhibitors should be discontinued if ketoacidosis is confirmed.

Inari large-bore mechanical thrombectomy in intermediate-high risk submassive PE patients: Case series and literature review

Pulmonary embolism (PE) is one of the most common causes of cardiovascular (CV) mortality worldwide. Owing to the associated morbidity and mortality with other treatment modalities, including systemic thrombolysis, a discernible change in the era of acute pulmonary embolism management has been reported. Catheter-directed thrombectomy using the FlowTriever system (Inari Medical; Irvine, CA, USA) was shown to reduce endpoints of interest in patients with acute intermediate-high risk PE and was associated with rapid hemodynamic improvement. In this report, we describe our experience with three cases of patients presenting with submassive PE, whereby immediate pulmonary artery pressure improvement was evident in all cases after successful mechanical thrombectomy. Our experience supports the use of FlowTriever mechanical thrombectomy for the treatment of submassive PE in clinical practice, with a call for further research to establish associated benefits.

The overestimation of concentric hypertrophy in patients with HFpEF as determined by 2D- echocardiography

Background: Heart failure with preserved ejection fraction continues to pose multiple challenges in terms of accurate diagnosis, treatment, and associated morbidity. Accurate left ventricular (LV) mass calculation yields essential prognostic information relating to structural heart disease. Two-dimensional (2D) echocardiography-based calculations are solely limited to LV geometric assumptions of symmetry, whereas three-dimensional (3D) echocardiography could overcome these limitations. This study aims to compare the performance of 2D and 3D LV mass calculations.

Methods: A prospective review of echocardiography findings at the University of Louisville, Kentucky, was conducted and assessed. Normal ejection fraction (EF) was defined as >=52% in males and >=54% in females. The following calculations were performed: relative wall thickness (RWT) = 2x posterior wall thickness/LV internal diastolic dimension (LVIDd) and 2D LV mass = 0.8{1.04([LVIDd + IVSd +PWd]³ − LVIDd³)} + 0.6. Concentric hypertrophy was RWT >0.42 and LV mass >95 kg/m² in females or >115 kg/m² in males. The same cut-offs were used for 2D and 3D echocardiography.

Results: Echocardiographic findings for a total number of 154 patients in the study were investigated. There was a weak positive correlation between 2D and 3D LV mass indices (R = 0.534, r2 = 0.286, p = 0.001). Seventy patients had 3D EF >=45% with clinical heart failure (HFpEF). Among HFpEF patients, LV hypertrophy (LVH) was present in 74% of patients by 2D echocardiography and 30% by 3D echocardiography (McNemar test p = 0.001). Using 3D echocardiography as the reference, 68% of normal patients were misdiagnosed with LV hypertrophy by 2D echocardiography. Two-thirds of the patients with concentric remodeling by 3D echocardiography were misclassified as having concentric hypertrophy by 2D echocardiography (p = 0.001).

Conclusion: Adapting necropsy-proven LV mass index cutoffs, 2D over-diagnosed LV hypertrophy through overestimation of the mass, compared to 3D echocardiography. In turn, the majority of HFpEF patients showed no structural hypertrophy of the LV on 3D imaging. This suggests that the majority of patients with HFpEF may qualify for pharmacological prevention to prevent further progression to LV remodeling or LVH.

The undesirable communication: A case of cerebral air emboli in the setting of atrio- esophageal fistula following atrial fibrillation catheter ablation

Atrial-esophageal fistula is an extremely rare condition but is often a deleterious complication following catheter ablation for atrial fibrillation. The associated iatrogenic communication acts as a conduit for air and bacterial translocation, which may lead to cerebral air embolism and polymicrobial sepsis, respectively. Coupled with a history of invasive procedures, the diagnosis is largely based on the accompanying neurological symptoms. In this report, we present the case of a 73-year-old female who presented with neurological deficits attributed to cerebral vascular emboli three weeks after catheter ablation for the treatment of chronic atrial fibrillation.

Electronic Cigarettes: Are They Smoking Cessation Aids or Health Hazards?

The US Food and Drug Administration (FDA) recently approved the marketing of an electronic cigarette (e-cig) brand called Vuse (RJ Reynolds Vapor Company, US) to help aid in smoking cessation for adult smokers. It was believed that the consumption of traditional cigarettes and their harmful effects would be reduced given the availability of newer e-cigarettes. However, adolescent use of tobacco and nicotine products rather increased with the availability of the same e-cigarettes, and the FDA-approved market boom only worsened this problem. Although the FDA underlines the importance of marketing e-cigarettes as a possible solution for adult traditional smoking, its consequences on adolescents' health raise many concerns, which we narrated in this review article.

A Rare Case of Creutzfeldt-Jakob Disease With Alcohol Use Disorder and Review of Literature

Sporadic Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative disorder, accounting for a majority of the sporadic prion disease burden. This disorder rapidly progresses and is often fatal with no known cure. Initial diagnosis may be delayed due to its varied presentations, which can include psychiatric changes (behavioural and mood variances), visual and auditory hallucinations, cerebellar dysfunction, and pain, occurring in isolation in many cases. Due to the nonspecific complaints, accurate diagnosis can be challenging. CJD exhibits symptoms similar to other neuropsychiatric illnesses; however, only a few reports have been published concerning the association between CJD and alcohol-related illnesses. This case report demonstrates the challenge of diagnosing this disorder early in the clinical course given the variable presentation, especially in a patient with a history of an alcohol use disorder, falls, and cognitive decline.

Multisystem Inflammatory Syndrome in a Young Adult Following COVID-19 Infection: A Case Report

Multisystem inflammatory syndrome (MIS) after a primary infection with coronavirus disease 2019 (COVID-19) was first recognized in 2020 and presents with similar symptoms as Kawasaki disease, toxic shock syndrome, and macrophage activation syndrome/secondary hemophagocytic lymphohistiocytosis. In children, it is called multisystem inflammatory syndrome in children (MIS-C); in adults, it is termed multisystem inflammatory syndrome in adults (MIS-A). This case offers a unique presentation of MIS in a 20-year-old young adult, who turned 21 years old one week after his presentation. He fits the criteria for MIS-C and MIS-A according to the Centers for Disease Control and World Health Organization, respectively. Initial symptoms in the emergency department included headache, neck stiffness, and fever with diffuse rash. Other symptoms consistent with MIS-C/A developed rapidly later during the course of the disease.

A review of adverse effects of COVID-19 vaccines

The COVID-19 pandemic has led to unanticipated pressures on all aspects of human life. Multiple approaches to eliciting protective immunity must be rapidly evaluated. Numerous efforts have been made to develop an effective vaccine for this novel coronavirus, resulting in a race for vaccine development. To combat COVID-19, all nations must focus their efforts on widespread vaccination with an effective and safe vaccine. Globally, concerns about potential long-term adverse effects of vaccines have led to some apprehension about vaccine use. A vaccine's adverse effect has an integral role in the public's confidence and vaccine uptake. This article reviews the current primary literature regarding adverse effects associated with different COVID-19 vaccines in use worldwide.

Differential mortality with COVID-19 and invasive mechanical ventilation between high-income and low-and middle-income countries: a systematic review, meta-analysis, and meta-regression

The COVID-19 pandemic has markedly affected the health care of patients in low- and middle-income countries (LMICs), but no systematic study to corroborate this effect has been undertaken. In addition, the survival outcomes of patients with COVID-19 who received invasive mechanical ventilation (IMV) have not been well established. We pooled evidence from all available studies and did a systematic review and meta-analysis to assess and compare mortality outcomes between LMICs and high-income countries (HICs). We searched MEDLINE and the University of Michigan Library according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from December 1, 2019, to July 15, 2021, for case-control studies, cohort studies, and brief reports that discussed mortality ratios and survival outcomes among patients with SARS-CoV-2 who received IMV. We excluded studies and case reports without comparison groups, narrative reviews, and preprints. A random-effects estimate of the arcsine square root transformation (PAS) of each outcome was generated with the DerSimonian-Laird method. Seven eligible studies, consisting of 243,835 patients with COVID-19, were included. We identified a significantly higher mortality rate (i.e., a larger PAS) among the patients receiving IMV in LMICs (PAS, 0.754; 95% CI, 0.569-0.900; P<.001) compared to patients in HICs (PAS, 0.588; 95% CI, 0.263-0.876; P<.001). Considerable heterogeneity was present within the individual subgroups possibly because of the extent of the included studies, which had data from specific countries and states but not from individual hospitals or health care centers. Moreover, the sample population in each study was diverse. Meta-regression showed that a higher mortality rate among patients with COVID-19 who received IMV in both HICs (P<.001) and LMICs (P=.04) was associated with chronic pulmonary disease. Our study suggests that chronic pulmonary diseases and poor demographics lead to a worse prognosis among patients with COVID-19 who received IMV. Moreover, the survival outcome is worse in LMICs, where health care systems are usually understaffed and poorly financed.

Significance of Educational Literature and Diabetes Log Sheet on Hemoglobin A1c

Diabetes mellitus (DM) is a major cause of morbidity worldwide. The prevalence of DM has doubled over the last 35 years and is escalating. Various complications and manifestations of diabetes have caused numerous deaths worldwide, with numbers increasing every year. There have been many advances and breakthroughs over the past decade in the management of DM. The major focus of many research studies has been to evaluate effective medication combinations, preventative measures, and the way to control such morbid conditions. Our focus in this review is to discuss specific secondary prevention techniques with the diabetes log sheet and educational literature on its effectiveness in controlling diabetes. Hemoglobin A1c (HbA1c) has been accepted as a diabetes control measure in many resources worldwide. Here, we have assessed articles on the effectiveness of the diabetes log sheet and educational literature on HbA1c levels. We will begin with a few key points to acknowledge diabetes initially, followed by discussing the effectiveness of the diabetes log sheet and literature on HbA1c.

Food Allergy Prevention: Early Versus Late Introduction of Food Allergens in Children

The emergence of food allergies in children is crucial for various medical fields seeking a viable strategy for allergy prevention. The most well-recognized approach adopted by numerous health care and government institutions hinges on the delay in the introduction of food allergens, which supposedly protects infants from sensitization and decreases the possibility of allergy development. However, recent experimental findings indicate that the benefits of this approach might be overestimated, as early exposure to allergenic foods has been shown to yield more advantageous outcomes. Multiple investigations on the causes of allergic diseases report that avoiding food allergies might be related to early consumption of these allergens. Alternatively, delaying the contact with allergenic nourishments, explored in contemporary research, has been proven to result in a higher prevalence of allergies among children, originating such conditions as atopic diseases and extreme sensitization to foods. The current paper compares the two prominent strategies of allergenic food introduction, gathering the most pertinent modern evidence to distinguish whether exposure to food allergens should be delayed or advanced.

Subacute necrotizing fasciitis of the posterior neck disguised as a herpes zoster infection: A case report

Necrotizing fasciitis is a rare soft tissue infection characterized by a rapidly spreading infection of the subcutaneous tissue. Early diagnosis is important as it requires immediate and complete debridement of infected tissues and antibiotic therapy. Necrotizing fasciitis usually involves the extremities, abdomen, and groin, but rarely involves the head and neck. Necrotizing fasciitis has an aggressive course; however, in rare cases, it can present in a subacute indolent form which can be misdiagnosed as other cutaneous diseases. Our case is a unique presentation of subacute necrotizing fasciitis of the posterior neck, which was initially diagnosed as a herpes zoster infection, in a patient with undiagnosed diabetes mellitus, which was complicated with diabetic ketoacidosis and sepsis.

Granulomatous Polyangiitis With Renal Involvement: A Case Report and Review of Literature

Granulomatosis with polyangiitis (GPA), formerly named Wegner’s granulomatosis is an antineutrophilic cytoplasmic antibody (ANCA) associated vasculitis of the small vessels. GPA can affect several organ systems even though predominantly affects respiratory and renal systems. Pathogenesis is initiated by activation of the immune system to produce ANCA, Cytoplasmic (C-ANCA) antibody, which thereby leads to widespread necrosis and granulomatous inflammation. Multisystem involvement with varied symptomatology makes GPA diagnosis more challenging. Early diagnosis and management are vital and can alter the prognosis of the disease. We present a literature review and a clinical scenario of a 26-year-old male with a history of chronic sinusitis, testicular carcinoma in remission, recent onset of worsening cough, epistaxis, hoarseness of voice, weight loss, and dark-colored urine. Workup revealed high titers of C-ANCA, C-reactive protein, procalcitonin, CT chest evidence of mass-like consolidation, and bronchoscopy findings of friable tissue that was not amenable for biopsy. Methylprednisolone and rituximab (RTX) were administered, which resulted in marked clinical improvement. Therefore, a keen eye for details is necessary to diagnose GPA early, which can improve disease outcomes dramatically.

The Pathophysiology of Anorexia Nervosa in Hypothalamic Endocrine Function and Bone Metabolism

Anorexia nervosa (AN) is a persistent psychiatric disorder that is marked by abnormal reduced weight and amenorrhea, which may be primary or secondary. AN affects multiple endocrine axes such as gonadal, thyroid, and adrenal axis, growth hormone, and insulin-like growth factor-1, adipokines such as leptin, gut peptides like ghrelin, peptide YY, and amylin. As a result of these changes bone mineral density is reduced, which increases the risk of bone fracture in patients. In this review, we focus on substantial endocrine alterations in AN with a particular emphasis on the severe bone loss associated with this condition and current bone therapies. The disorder primarily affects girls and women, who are the focus of this review. Although the majority of AN-related endocrinopathies improve over time, long-term consequences such as short stature, osteoporosis, and infertility may occur. To avoid serious consequences, nutrition therapy in these patients requires a full understanding of bone complications, and new therapeutic options for treatment should be researched.

A Review of the Quiz, as a New Dimension in Medical Education

Over the years, medical education delivery has seen a change from teacher-centric to student-centric teaching-learning methods. Educators are constantly looking to develop interactive and innovative teaching-learning tools. One such supplementary tool is the use of the quiz for medical education. The Quiz has been used traditionally as a feedback assessment tool, but lately, it has found its way into the medical curriculum, mostly informally. The few available documented studies on the Quiz as a teaching and learning tool illustrate its acceptance and impact on the stakeholders. It could be one of the solutions to the endless search for a student-centric and engaging tool to deliver the medical curriculum. Commonly, the format for medical quiz is either on a case-based or image-based approach. Such an approach helps bridge the gap between traditional classroom teaching and clinical application. The Quiz is a readily acceptable tool that complements didactic lectures and improves students' learning and comprehension. Being an interactive student-centric tool, it enhances active student participation and encourages regular feedback mechanisms. It promotes healthy competition and peer-assisted learning by encouraging active discussion among students, hence improving student performance in standard examination techniques, along with teacher satisfaction. This literature review aims to enumerate the various formats of the Quiz, their role in improving the understanding and retention of knowledge among the students and assess their acceptability among the stakeholders.

Gastric Intestinal Metaplasia and Its Rapid Progression Toward Gastric Adenocarcinoma: A Call for Clear Patient Management and Awareness

Gastric cancer is one of the leading causes of cancer-related death worldwide. Helicobacter pylori (H. pylori) infection is known to cause gastric adenocarcinoma in a stepwise fashion. Gastric intestinal metaplasia is a known premalignant stage. We report a case of a 70-year-old male patient with active chronic H. pylori-associated gastritis and focal intestinal metaplasia on the initial presentation, who rapidly developed diffuse, poorly differentiated gastric adenocarcinoma 20 months after the loss to follow-up. Our case highlights the premalignant nature of gastric intestinal metaplasia (GIM) and the extreme importance of early eradication of H. pylori. We also address the lack of definitive GIM surveillance guidelines.

Pharmacologic Management of Coronary Artery Ectasia

Coronary artery ectasia (CAE) is a rare form of aneurysmal coronary heart disease. It is defined as a dilatation of the coronary artery by more than one-third of its length and with a diameter 1.5 times of a normal coronary artery adjacent to it. This condition increases the risk of angina pectoris and acute coronary syndrome. Hence, we discuss the pharmacologic options for primary and secondary prevention of CAE complications. Antiplatelets such as aspirin are considered the mainstay of treatment in patients with CAE. Anticoagulants such as warfarin are warranted on a case-by-case basis to prevent thrombus formation depending on the presence of concomitant obstructive coronary artery disease and the patient’s risk of bleeding. Since atherosclerosis is the most common cause of CAE, statins are indicated in all patients for primary prevention. Angiotensin-converting enzyme (ACE) inhibitors may be indicated, especially in hypertensive patients, due to their anti-inflammatory properties. Beta-blockers may be indicated due to their antihypertensive and anti-ischemic effects. Calcium (Ca) channel blockers may be needed to prevent coronary vasospasm. Nitrates are generally contraindicated as they may lead to worsening of symptoms. Other antianginal medications such as trimetazidine can improve exercise tolerance with no reported adverse events in these patients.

Exosome-Derived microRNA: Efficacy in Cancer

Exosome-derived microRNA (miRNA) has been the focus of attention in recent years. Mainly, their role in the pathogenesis of different types of cancer has been extensively studied. The different types of exosomal miRNAs (exomiRs) act as either oncogenes or oncosupressors. They have potential prognostic and diagnostic efficacy in different types of cancer due to their high stability and easy detection in bodily fluids. This is especially true in lung cancer, colorectal cancer, ovarian cancer, and breast cancer. However, their efficacy as potential therapies has not been widely investigated. This review will discuss the structure and functions of exosomes and miRNA, as well as the role of exomiRs in the pathogenesis of different types of cancer through boosting growth, promoting progression, chemotherapy resistance, angiogenesis, metastasis, and immune system evasion. We will also discuss the application of exomiRs in diagnosing different types of cancer and their role in prognosis. Furthermore, we shed light on the challenges of developing therapeutic agents using miRNAs and how the carriage of therapeutic miRNA by exosomes can help solve these challenges. Finally, we examine recent studies exploring the potential of exomiRs in treating cancers such as neuroblastoma, glioblastoma, and melanoma.

Non-Alcoholic Fatty Liver Disease and Its Association With Diabetes Mellitus

There is a bidirectional relationship between non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). The liver has a vital role in the pathophysiology of both diseases as it leads to the development of insulin resistance (IR), which in turn results in NAFLD and T2DM. It has been shown that T2DM increases the risk of NAFLD progression. Furthermore, the presence of NAFLD raises the probability of T2DM complications, which explains the increased rates of NAFLD screening in patients with T2DM. In addition, there are common management options for the two diseases. Lifestyle changes can play a role in the initial management of both diseases. Medications that are used to treat T2DM are also used in the management of NAFLD, such as metformin, thiazolidinediones (TZD), glucagon-like peptide-1 (GLP-1) analogues, and dipeptidyl peptidase-4 (DPP4) inhibitors. Bariatric surgery is often used as a last resort and has shown promising results. Lifestyle interventions with diet and exercise are important postoperatively to maintain the weight loss. There are many novel treatments that are being investigated for the treatment of NAFLD, targeting multiple pathophysiologic pathways. This review aims to shed some light on the intricate relationship between NAFLD and T2DM and how IR links both diseases. We also try to raise awareness among clinicians about this relationship and how the presence of one disease should raise a high index of suspicion for the existence of the other.

Pandemics Throughout the History

As we move amidst the coronavirus disease 2019 (COVID-19) pandemic, we have witnessed tremendous distress, death, and turmoil of everyday life for more than one year now. However, they are not modern phenomena; deadly pandemics have happened throughout recorded history. Pandemics such as the plague, Spanish Flu, HIV, and Ebola caused deaths, destruction of political regimes, as well as financial and psychosocial burdens. However, they sometimes resulted in scientific discoveries. Understanding the mechanism of the emergence of these pandemics is crucial to control any spreading pandemic and prevent the emergence of a potential new one. Public health agencies need to work on improving the countries' pandemic preparedness to prevent any future pandemics. The review article aims to shed light on some of the deadliest pandemics throughout history, information of critical importance for clinicians and researchers.

Paired-Box Gene 8 (PAX8) and Its Association With Epithelial Carcinomas

Cancer is the second most common culprit of mortality in the United States and epithelial carcinomas are considered as one of the most predominant types of cancer. The association between epithelial cancers and paired-box gene 8 (PAX8) has been studied significantly before. PAX8 belongs to the paired-box gene family, which plays an important role in the organogenesis of different body organ systems, especially the thyroid gland, the renal system, and the Müllerian system. Immunohistochemical staining is being used to detect PAX8 expression in different epithelial cancers and differentiate them from PAX8-negative tumors. In follicular, papillary, and anaplastic thyroid carcinomas, targeting the PAX8/peroxisome proliferator-activated receptors (PPARs) fusion protein is being considered as a potential mechanism for therapy. Moreover, because of its high expression in primary ovarian cancers, PAX8 is being considered as a target for ovarian cancer treatment as well. More studies are needed to test the possibility of using PAX8 as a possible target for managing endometrial carcinomas. In this article, we review the functions of the PAX8 gene, how its mutations lead to the development of certain epithelial carcinomas, how it can be used as a diagnostic or a prognostic marker, and its potential as a therapeutic target for these cancers.

HIV and Messenger RNA (mRNA) Vaccine

Human immunodeficiency virus (HIV) is a part of the lentivirus genus of the retroviridae family that incorporates its genome into the host DNA via a series of complex steps. HIV can be classified into two types, HIV-type 1 (HIV-1) and HIV-type 2 (HIV-2), with HIV-1 being the most common type worldwide. Seventy-six million people have been infected since the start of the pandemic, with a mortality rate of 33 million. Even after 40 years, no cure has been developed for this pandemic. The development of the mRNA vaccine has led to further research for the utilization of mRNA vaccine in HIV, in attempts to create a prophylactic and therapeutic treatment. Although messenger RNA (mRNA) vaccine has been around for many years, it has recently drawn attention due to its role and response in the unforeseen coronavirus pandemic. mRNA vaccine has faced its fair-share of challenges, but it also offers many advantages compared to conventional vaccines such as safety, efficacy, rapid preparation, and versatility. mRNA vaccine has shown promising results and has great potential. In this review, we discuss the types of mRNA vaccine, along with development, delivery, advantages, challenges, and how we are working to overcome these challenges.

Mechanisms and Potential Treatment Options of Heart Failure in Patients With Multiple Myeloma

Multiple myeloma is a pathology of plasma cells, with one of the most common side effects of its treatment is heart failure. In addition, cardiac amyloidosis could cause heart failure by itself. Even though mechanisms of cardiac amyloidosis are known, and they involve lysosomal dysfunction, reactive oxygen species (ROS) accumulation, and infiltrative effect by fibrils, there is no specific agent that could protect from these effects. While the molecular mechanism of doxorubicin cardiotoxicity via topoisomerase II β is established, the only FDA-approved agent for treatment is dexrazoxane. Liposomal doxorubicin can potentially improve response and decrease the development of heart failure due to microscopic liposomes that can accumulate and penetrate only tumor vasculature. Supplements that enhance mitochondrial biogenesis are also shown to improve doxorubicin-induced cardiotoxicity. Other agents, such as JR-311, ICRF-193, and ursolic acid, could potentially become new treatment options. Proteasome inhibitors, novel agents, have significantly improved survival rates among multiple myeloma patients. They act on a proteasome system that is highly active in cardiomyocytes and activates various molecular cascades in malignant cells, as well as in the heart, through nuclear factor kappa B (NF-kB), endoplasmic reticulum (ER), calcineurin-nuclear factor of activated T-cells (NFAT), and adenosine monophosphate-activated protein kinase (AMPKa)/autophagy pathways. Metformin, apremilast, and rutin have shown positive results in animal studies and may become a promising therapy as cardioprotective agents. This article aims to highlight the main molecular mechanisms of heart failure among patients with multiple myeloma and potential treatment options to facilitate the development and research of new preventive strategies. Hence, this will have a positive impact on life expectancy in patients with multiple myeloma.

Comparison between standard solid fuel and a new annular fuel performance in the core of a PWR

In new generation PWR the annular fuel has been proposed as one of the options to achieve higher power density, larger safety margin and reduced electricity generation cost. In the current work, RELAP5 code is used to compare the thermal hydraulic parameters for both solid fuel and internally and externally cooled annular fuel in a core of a PWR. MCNP6 code is used to evaluate the neutronic design and basic safety parameters of the annular fuel. To accomplish this goal, RELAP5 input files for both solid and annular fuels are developed. In these files, a 13 · 13 array annular fuel design is used while the 17 · 17 standard array design is used for the solid fuel. A 100% core power, steady state normal operation is assumed in the current investigation. Also, MCNP6 code input files for both fuels are prepared. It is found that annular fuel has lower peak fuel temperature than the standard solid fuel, which is an important advantage of the annular fuel rather than the solid one. Also, comparisons were performed for reactivity feedback coefficients of the two fuel types at BOC. Burnup calculations were performed to study the energy conversion capability of the annular fuel as well as rim effects.

Validation of RELAP5 model of experimental test rig simulating the natural convection in MTR research reactors

In an attempt to understand the built-up of natural circulation in MTR pool type upward flow research reactors after loss of power, an experimental test rig was built to simulate the loop of natural circulation in MTR reactors. The test rig consisting of two vertically oriented branches, in one of them the core is simulated by two rectangular, electrically heated, parallel channels. The other branch simulates the part of the return pipe that participates in the development of core natural circulation. In the first phase of the work, many experimental runs at different conditions of channel's power and branch's initial temperatures are performed. The channel's coolant and surface temperatures were measured. The measurements and their interpretation were published by the first three authors. In the present work the thermal hydraulic behavior of the test rig is complemented by theoretical analysis using RELAP5 Mod 3.3 system code. The analysis consisting of two parts; in the first part RELAP5 model is validated against the measured values and in the second part some of the other not measured hydraulic parameters are predicted and analyzed. The test rig is typically nodalized and an input dick is prepared. In spite of the low pressure of the test rig, the results show that RELAP5 qualitatively predicts the thermal hydraulic behaviour and the accompanied phenomenon of flow inversion of such facilities. Quantitatively, there is a difference between the predicted and measured values especially the channel's surface temperature. This difference may be return to the uncertainties in initial conditions of experimental runs, the position of the thermocouples which buried inside the heat structure, and the heat transfer package in RELAP5.

Thermal hydraulic analysis of reactivity accidents in MTR research reactors using RELAP5

The present paper comes in the line with the international approach which use the best estimate codes, instead of conservative codes, to get more realistic prediction of system behavior under off-normal reactor conditions. The aim of the current work is to apply this approach using the thermal-hydraulic system code RELAP5/Mod3.3 in a reassessment of safety of the IAEA benchmark 10 MW Research Reactor. The assessment is performed for both slow and fast reactivity insertion transients at initial power of 1.0 W. The reactor power is calculated using the RELA5 point kinetic model. The reactivity feedback terms are considered in two steps. In the first step the feedback from changes in water density and fuel temperature (Doppler effects) are considered. In the second step the feedback from the water temperature changes is added. The results from the first step are compared with that published in IAEA-TECDOC-643 benchmarks. The comparison shows that RELAP5 over predicts the peak power and consequently the fuel, clad and coolant temperatures in case of fast reactivity insertion. The results from the second step show unjustified values for reactor power. Therefore, the model of reactivity feedback from water temperature changes in the RELAP5 code may have to be reviewed.

Review of regulatory requirements relevant to calibration of monitoring instruments in research reactors

The objective of this work is to demonstrate the regulatory requirements pertaining to calibration of monitoring instruments in research reactors. The regulatory statements concerning this subject in IAEA safety standards and the implementation of such regulations in twelve countries with different levels of nuclear programs are surveyed: Australia, Bulgaria, Canada, Egypt, Finland, Germany, Hungary, Slovenia, South Korea, Spain, United Kingdom of England and United States of America. In addition, the requirements of ISO/IEC17025 and NUPIC (Nuclear Utilities Procurement Issues Committee) are compared. Seven technical and administrate aspects are suggested as the comparison criteria and the explicit expression of the statements, the level of document (i. e.: act, requirement or guide) are the considered resources. The main differences and similarities between the different approaches are identified in order to provide an input for future development of the national regulations.

Experimental study of flow inversion in MTR upward flow research reactors

The core cooling of upward flow MTR pool type Research Reactor (RR) at the later stage of pump coast down is experimentally handled to clarify the effect of some operating parameters on RR core cooling. Therefore, a test rig is designed and built to simulate the core cooling loop at this stage. The core is simulated as two vertical channels, electrically heated, and extended between upper and lower plenums. Two elevated tanks filled with water are connected to the two plenums. The first one constitutes a left branch, connected to the lower plenum, and is electrically heated to simulate the core return pipe. The second one constitutes the right branch, connected to the upper plenum, and is cooled by refrigerant circuit to simulate the reactor pool. Channel coolant and wall temperatures at different power and branch temperatures are measured, registered and analyzed. The results show that at this stage of core cooling two cooling loops are established; an internal circulation loop between the channels dominated by the difference in channel's power and an external circulation loop between the branches dominated by the temperature difference between branches. Also, there is a double inversion in core flow, upward-downward-upward flow. This double inversion increases largely the channel's wall temperature. Complementary safety analysis to evaluate this phenomenon must be performed.

Liquid chromatographic method for the analysis of buspirone HCl and its potential impurities

An accurate, reproducible, and sensitive method for the determination of buspirone HCl and its potential impurities is developed and validated. The validated liquid chromaography method is conducted to meet the Food and Drug Administration/ International Conference on Harmonization requirements for the analysis of buspirone HCI in the presence of its impurities. Five buspirone HCI potential impurities, including 1-(2-pyrimidinyl)-piperazine (I), propargyl chloride (II), 3,3'-tetramethylene glutarimide (III), propargyl glutarimide (IV), and the Mannich base-condensate of I-IV fumarate (V), are separated using a microBondapack C18 column by gradient elution with a flow rate 2.0 mL/min. The initial mobile phase composition is 90:10 (v/v) 10mM KH2PO4 (pH 6.1)-acetonitrile. After a 1-min initial hold, a linear gradient is performed in 26 min to 35:65 (v/v) 10mM KH2PO4 (pH 6.1)-acetonitrile. The samples are detected at 210 and 240 nm using a photo-diode array detector. The linear range of detection for buspirone HCI was between 1.25 ng/microL and 500 ng/microL, with a limit of quantification of 1.25 ng/microL. The linearity, range, peak purity, selectivity, system performance parameters, precision, accuracy, and robustness for all of the impurities were also shown to have acceptable values.

Stability-indicating high-performance liquid chromatographic assay of buspirone HCl

The United States Pharmacopoeia high-performance liquid chromatographic (HPLC) assay method of buspirone is not able to discriminate buspirone from its degradation products. The purpose of this work is to develop a sensitive, selective, and validated stability-indicating HPLC assay for the analysis of a buspirone hydrochloride in a bulk drug. Buspirone HCI and its potential impurities and degradation products are analyzed on an Ultrasphere C18 column heated to 40 degrees C using a gradient program that contains monobasic potassium phosphate buffer solution (pH 6.9) and acetonitrile-methanol mixture (13:17) of 35% for 5 minutes, then increased to 54% in 5.5 minutes. The samples are monitored using a photo-diode array detector and integrated at 244 and 210 nm. The stress testing of buspirone HCI shows that buspirone acid hydrochloride is the major degradation product. The developed method shows a separation of buspirone degradation product and its potential impurities in one run. The stability of buspirone HCI is studied under accelerated conditions in order to provide a rapid indication of differences that might result from a change in the manufacturing process or source of the sample. The forced degradation conditions include the effect of heat, moisture, light, acid-base hydrolysis, sonication, and oxidation. The compatibility of buspirone HCI with some pharmaceutical excipients is studied under stress conditions. The linear range of buspirone HCI is between 5 and 200 ng/microL with a limit of quantitation of 2.5 ng/microL. The intraassay percentage deviation is not more than 0.38%, and the day-to-day variation was not more than 0.80%. The selectivity, repeatability, linearity, range, accuracy, sample solution stability, ruggedness, and robustness show acceptable values.

3-Bromomethyl-propyphenazone as a new derivatization reagent for high performance liquid chromatography of captopril and hydrochlorothiazide with UV-detection

3-Bromomethyl-propyphenazone (BMP) was used as a derivatization reagent for the detection and quantification of captopril (CAP) and hydrochlorothiazide (HCT) by high performance liquid chromatography using Zorbax C8 column, and 0.05M sodium acetate, acetonitrile, methanol (14:17:4; pH 6.5) as mobile phase system with UV-detection at 254 nm. The cited reagent reacts with the mercapto and amino groups of CAP and HCT in acetone using anhydrous potassium carbonate as hydrobromide acceptor. The reaction was completed within 30 min for CAP and 60 min for HCT with heating at 105 +/- 5 degrees C in mini-reaction vial. The linear concentration ranges for both CAP and HCT were 8 to 160 and 6 to 140 ng per injection, respectively. The derivatized captopril was synthesized and confirmed with spectral analysis. This method was applied for determination of spiked captopril in human urine after extraction with Extrelut-20 column using ethyl acetate:isopropanol (85:15 v/v) as eluant.

Stereoselective metabolic study of famprofazone

Famprofazone (1) metabolites were studied in human urine after medication by 50 mg oral dose. The human urine was collected over 48 h from six volunteers at time intervals of 6, 12, 24 and 48 h. The amount of famprofazone metabolites were recovered from the urine samples by application of Extrelut extraction method. The resultant extracts were derivatized using N-methyl-N-trimethylsilytrifluoroacetamide (MSTFA) for trimethylsilylation followed by N-methyl-bis-trifluoroacetamide (MBTFA) for trifluoroacetylation. Methamphetamine (2) and 3-hydroxymethyl-propyphenazone (3), excreted in human urine, were identified as famprofazone metabolites by gas chromatography-mass spectrometry (GC-MS). The quantitative results revealed that the average amounts of 2 and 3, excreted in human urine were equal to 2.6 and 4 mg, respectively, through 48 h. However, 3 was analysed after enzymatic hydrolysis of the urine samples using beta-glucuronidase/arylsulphatase. The excreted methamphetamine enantiomers could be separated by application of indirect GC-technique using S-(-)-N-trifluoroacetylprolyl chloride (TPC) as a chiral derivatizing agent. The average amount of (-)-methamphetamine isomer excreted in the urine was found to be three fold those of the (+)-isomer.

On-line precolumn derivatization for HPLC determination of methotrexate using a column packed oxidant

A high-performance liquid chromatographic method involving on-line precolumn oxidative cleavage and fluorimetric detection was developed for the determination of methotrexate in plasma. Plasma samples were subjected to protein precipitation followed by solvent purification and then injection into the chromatographic system. Cerium (IV) trihydroxyhydroperoxide (CTH) was introduced as a packed oxidant before analytical column for the conversion of methotrexate into highly fluorescent 2,4-diaminopteridine derivatives. The oxidative cleavage of methotrexate occurs during the flow of 0.04 M phosphate buffer (pH 3.5) containing the drug through CTH column with a flow-rate of 0.2 mL/min at 40 degrees C. The separation was performed on a reversed-phase column (ODS/TM) using a mobile phase consisting of phosphate buffer (0.05 M, pH 6.6) and acetonitrile (90:10 v/v). The fluorescent products were monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. Validation of accuracy and precision were satisfactory for both within- and between-run assays. All coefficients of variance were less than 4% and mean relative errors were within 1.11% to 7.83%. The average recovery was found to be 93.74% to 98.11%. The proposed method is highly sensitive, specific and applicable to biological fluids.

High-performance liquid chromatography of alpha-amino acids and aztreonam on reversed phase columns with aqueous Cu2+ as eluent

Parameters affecting the separation of amino acids on different RP-HPLC columns were studied. Six amino acids were separated on Zorbax TMS, Zorbax CN, Zorbax ODS and Zorbax C8, using 1.8 x 10(-3) M copper sulphate at pH 4.1 as aqueous mobile phase. The best separation was shown by Zorbax TMS followed by Zorbax CN. The column performance was maintained by serial washing after 6 h continuous work with aqueous 10(-4) M disodium edetate, 10(-4) N sulphuric acid, water and gradient elution with aqueous methanol. The separation mechanism was interpreted. The method was applied for separation and quantification of aztreonam and L-arginine in Azactam vials.