Phase separation in mullite-composition glass.

Aluminosilicates (AS) are ubiquitous in ceramics, geology, and planetary science, and their glassy forms underpin vital technologies used in displays, waveguides, and lasers. In spite of this, the nonequilibrium behavior of the prototypical AS compound, mullite (40SiO2-60Al2O3, or AS60), is not well understood. By deeply supercooling mullite-composition liquid via aerodynamic levitation, we observe metastable liquid-liquid unmixing that yields a transparent two-phase glass, comprising a nanoscale mixture of AS7 and AS62. Extrapolations from X-ray scattering measurements show the AS7 phase is similar to vitreous SiO2 with a few Al species substituted for Si. The AS62 phase is built from a highly polymerized network of 4-, 5-, and 6-coordinated AlOx polyhedra. Polymerization of the AS62 network and the composite morphology provide essential mechanisms for toughening the glass.

A 77-Year-Old Man with Heparin-Induced Aldosterone Suppression Causing Hyperkalemia.

BACKGROUND Anticoagulation with heparin infrequently causes elevated serum potassium via a reduction in the number and affinity of adrenal angiotensin II receptors, causing reversible aldosterone suppression, thereby leading to enhanced sodium excretion and hyperkalemia. CASE REPORT A 77 year-old man presented with productive cough and shortness of breath and was subsequently found to have non-ST-elevation myocardial infarction and concomitant symptomatic COVID-19 infection, for which he was started on a high-dose unfractionated heparin infusion. A gradual increase in serum potassium followed, with a subsequent return to a normal potassium level after stopping treatment with heparin. An evaluation for hemolysis was unrevealing, and the patient was not on any other medications known to cause hyperkalemia. On day 6, heparin was restarted owing to a high suspicion of pulmonary embolism. There was a subsequent increase in serum potassium level, which was followed by a return to baseline after discontinuation of heparin, thereby confirming the suspected diagnosis. CONCLUSIONS Acute increases in serum potassium levels in hospitalized patients can result in weakness, paralysis, conduction abnormalities, and cardiac arrhythmias that, if left untreated, can result in serious morbidity and potentially death in a short period of time. As this clinical entity is infrequently encountered in clinical practice, it can easily be overlooked by clinicians. The prompt exclusion of alternative causes of acutely elevated serum potassium levels and the identification of heparin administration as an easily reversible trigger is imperative and can potentially be life-saving.

The effect of breastfeeding on postpartum fructosamine and HbA1c values after normal pregnancy.

INTRODUCTION: Breastfeeding can lower postpartum oral glucose tolerance test results by 5%. Similar data do not exist regarding fructosamine and HbA1c. The primary outcome was to determine if breastfeeding would lower fructosamine values by 5%. METHODS: At the 4-8 week postpartum visit, women with uncomplicated pregnancies were given a questionnaire and had blood drawn for fructosamine and HbA1c. RESULTS: Breastfeeding (n = 22) and non-breastfeeding women (n = 28) were demographically similar, including postpartum weight loss. The respective values among breastfeeding and non-breastfeeding women were: fructosamine 2.20 versus 2.21 mmol/L; HbA1c 5.2% versus 5.2%. Only two of the seven women with an HbA1c of 5.7% or more had an abnormal fructosamine. CONCLUSION: After uncomplicated pregnancies, breastfeeding was not associated with lower levels of postpartum fructosamine or HbA1c. Future research to improve screening for persistent postpartum dysglycemia in high-risk populations can utilize these tests without concern that results will be confounded by breastfeeding.

Prevalence of abnormalities in electrocardiogram conduction in dialysis patients: a comparative study / Prevalência de anormalidades de condução no eletrocardiograma de pacientes em diálise: um estudo comparativo

ABSTRACT Background: The electrocardiogram (ECG) can aid in identification of chronic kidney disease (CKD) patients at high risk for cardiovascular diseases. Cohort studies describe ECG abnormalities in patients on hemodialysis (HD), but we did not find data comparing ECG abnormalities among patients with normal kidney function or peritoneal dialysis (PD) to those on hemodialysis. We hypothesized that ECG conduction abnormalities would be more common, and cardiac conduction interval times longer, among patients on hemodialysis vs. those on peritoneal dialysis and CKD 1 or 2. Methods: Retrospective review of adult inpatients' charts, comparing those with billing codes for "Hemodialysis" vs. inpatients without those charges, and an outpatient peritoneal dialysis cohort. Patients with CKD 3 or 4 were excluded. Results: One hundred and sixty-seven charts were reviewed. ECG conduction intervals were consistently and statistically longer among hemodialysis patients (n=88) vs. peritoneal dialysis (n=22) and CKD stage 1 and 2 (n=57): PR (175±35 vs 160±44 vs 157±22 msec) (p=0.009), QRS (115±32 vs. 111±31 vs 91±18 msec) (p=0.001), QT (411±71 vs. 403±46 vs 374±55 msec) (p=0.006), QTc (487±49 vs. 464±38 vs 452±52 msec) (p=0.0001). The only significantly different conduction abnormality was prevalence of left bundle branch block: 13.6% among HD patients, 5% in PD, and 2% in CKD 1 and 2 (p=0.03). Conclusion: To our knowledge, this is the first study to report that ECG conduction intervals are significantly longer as one progresses from CKD Stage 1 and 2, to PD, to HD. These and other data support the need for future research to utilize ECG conduction times to identify dialysis patients who could potentially benefit from proactive cardiac evaluations and risk reduction.

RESUMO Introdução: O eletrocardiograma (ECG) pode auxiliar na identificação de pacientes com doença renal crônica (DRC) e alto risco para doenças cardiovasculares. Estudos de coorte descrevem anormalidades no ECG de pacientes em hemodiálise (HD), mas não encontramos dados comparando anormalidades no ECG entre pacientes com função renal normal ou aqueles em diálise peritoneal (DP), com aqueles em hemodiálise. Nossa hipótese foi de que as anormalidades de condução no ECG seriam mais comuns, e o intervalo de condução cardíaca seria mais longo entre os pacientes em hemodiálise comparados àqueles em diálise peritoneal e DRC 1 ou 2. Métodos: revisão retrospectiva dos prontuários de pacientes adultos internados, comparando aqueles com códigos de cobrança para "Hemodiálise" versus pacientes internados sem esses encargos, e uma coorte de pacientes em diálise peritoneal ambulatorial. Pacientes com DRC 3 ou 4 foram excluídos. Resultados: Cento e sessenta e sete prontuários foram revisados. Os intervalos de condução no ECG foram consistente- e estatisticamente mais longos entre os pacientes em hemodiálise (n = 88) vs. em diálise peritoneal (n = 22) e DRC estágios 1 e 2 (n = 57): PR (175 ± 35 vs 160 ± 44 vs 157 ± 22 msec) (p = 0,009); QRS (115 ± 32 vs. 111 ± 31 vs 91 ± 18 ms) (p = 0,001); QT (411 ± 71 vs. 403 ± 46 vs 374 ± 55 ms) (p = 0,006 ), QTc (487 ± 49 vs. 464 ± 38 vs 452 ± 52 ms) (p = 0,0001). A única anormalidade de condução significativamente diferente foi a prevalência de bloqueio do ramo esquerdo: 13,6% nos pacientes em HD, 5% em DP e 2% na DRC 1 e 2 (p = 0,03). Conclusão: Pelo que sabemos, este é o primeiro estudo a relatar que os intervalos de condução no ECG são significativamente maiores à medida que se progride das DRC Estágios 1 e 2, para DP, e para HD. Esses e outros dados corroboram a necessidade de estudos futuros para utilizar os tempos de condução no ECG para identificar pacientes em diálise que poderiam se beneficiar de avaliações cardíacas proativas e assim redução de risco.

Prevalence of abnormalities in electrocardiogram conduction in dialysis patients: a comparative study.

BACKGROUND: The electrocardiogram (ECG) can aid in identification of chronic kidney disease (CKD) patients at high risk for cardiovascular diseases. Cohort studies describe ECG abnormalities in patients on hemodialysis (HD), but we did not find data comparing ECG abnormalities among patients with normal kidney function or peritoneal dialysis (PD) to those on hemodialysis. We hypothesized that ECG conduction abnormalities would be more common, and cardiac conduction interval times longer, among patients on hemodialysis vs. those on peritoneal dialysis and CKD 1 or 2. METHODS: Retrospective review of adult inpatients' charts, comparing those with billing codes for "Hemodialysis" vs. inpatients without those charges, and an outpatient peritoneal dialysis cohort. Patients with CKD 3 or 4 were excluded. RESULTS: One hundred and sixty-seven charts were reviewed. ECG conduction intervals were consistently and statistically longer among hemodialysis patients (n=88) vs. peritoneal dialysis (n=22) and CKD stage 1 and 2 (n=57): PR (175±35 vs 160±44 vs 157±22 msec) (p=0.009), QRS (115±32 vs. 111±31 vs 91±18 msec) (p=0.001), QT (411±71 vs. 403±46 vs 374±55 msec) (p=0.006), QTc (487±49 vs. 464±38 vs 452±52 msec) (p=0.0001). The only significantly different conduction abnormality was prevalence of left bundle branch block: 13.6% among HD patients, 5% in PD, and 2% in CKD 1 and 2 (p=0.03). CONCLUSION: To our knowledge, this is the first study to report that ECG conduction intervals are significantly longer as one progresses from CKD Stage 1 and 2, to PD, to HD. These and other data support the need for future research to utilize ECG conduction times to identify dialysis patients who could potentially benefit from proactive cardiac evaluations and risk reduction.

Iatrogenic Cushing's Syndrome Following Intra-Articular Triamcinolone Injection in an HIV-Infected Patient on Cobicistat Presenting as a Pulmonary Embolism: Case Report and Literature Review.

BACKGROUND: Iatrogenic Cushing's syndrome (ICS) typically develops after long-term exposure to corticosteroids, but it can occur after a single dose in patients treated with cobicistat or ritonavir for HIV. We present a patient who developed ICS due to the interaction between cobicistat and triamcinolone, a review of the literature, and what to our knowledge is the first case of ICS presenting as a pulmonary embolism. CASE PRESENTATION: A 55-year old male with a past medical history of human immunodeficiency virus, undetectable for 15 years and currently on elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide, received 2 intra-articular injections of triamcinolone one month apart for a Baker's cyst in his right knee. He used nasal fluticasone for 9 days in-between the injections. After his second knee injection, he developed easy bruising and friable skin. Over the coming months, he experienced weight gain and Cushingoid facies. Four months after the knee injections he developed a pulmonary embolism and deep vein thrombosis treated with warfarin. The Cushingoid facies prompted an evaluation and diagnosis of ICS along with hypothalamic pituitary adrenal axis suppression. CONCLUSION: This case demonstrates the need to monitor patients on pharmacological boosters with any exposure to corticosteroids, whether it be injected, inhaled, topical, oral or intravenous, as it can lead to profound adrenal suppression and ICS.

Tolosa-Hunt Syndrome: A Non-Classical Presentation of a Rare Cause of Unilateral Headache and Painful Ophthalmoplegia.

Tolosa-Hunt syndrome is a rare condition involving the orbital and retro-orbital space. The typical symptoms are orbital pain, swelling, headache, palsies of the cranial nerves, and sensory loss in the distribution of the trigeminal nerve. Tolosa-Hunt syndrome relapses and remits with episodes separated by months to years. It is a diagnosis of exclusion after ruling out other causes of painful ophthalmoplegia and is treated with high-dose steroids. We present a case of a 43-year-old woman with a history of recurrent headaches and vision disturbances for the past 4 years presenting with worsening left-eye pain that radiated to the back of her head, swelling around the left eye, double vision, and a unilateral left-sided headache. Visual acuity was decreased in the left eye compared to the right and the patient reported left-eye pain when at extreme medial and lateral gaze. Erythrocyte sedimentation rate (ESR) was found to be elevated with all other laboratory testing within normal limits. Computed tomography (CT) scan of the orbits was unremarkable. Ophthalmology excluded other differential diagnoses and she was treated with intravenous methylprednisolone with significant improvement of symptoms. The triad of one or more episodes of unilateral orbital pain, paresis of one or more of the cranial nerves, and granulomas by magnetic resonance imaging (MRI) or biopsy is 95-100% sensitive at diagnosing the syndrome; however, our patient did not present with the "classic" triad. Initial treatment of Tolosa-Hunt is with high-dose steroids which as in our case lead to rapid and significant improvement of symptoms.

A Case of Pneumatosis Intestinalis With Pneumoperitoneum as a Potential Delayed Adverse Effect of Capecitabine.

Ileitis and colitis are known complications of capecitabine when used in patients with gastrointestinal cancers. However, to our knowledge, pneumatosis intestinalis (PI) has not previously been reported with this medication. We present a patient with breast cancer, without any metastases to the gastrointestinal tract, who presented with persistent diarrhea 4 weeks after discontinuing adjuvant capecitabine, which was found to be due to PI. As she had no other risk factors or identifiable causes, her PI was attributed to a delayed reaction to capecitabine. This case highlights the need to consider PI earlier in the differential diagnosis in patients with breast cancer who present with unexplained diarrhea after recent discontinuation of capecitabine.

Identifying Alpha-1 Antitrypsin Deficiency Based on Computed Tomography Evidence of Emphysema.

Introduction Chronic obstructive pulmonary disease (COPD) is most commonly caused by smoking tobacco or cigarettes. However, alpha-1 antitrypsin deficiency (AATD) is the only genetic disorder known to cause COPD and these patients often present with emphysema earlier in life and with more severe disease. Additionally, AATD patients are often misdiagnosed with other lung disorders, and the diagnosis is often delayed for up to a decade. Furthermore, several clinicians may see the patient before genetic testing is performed and an official diagnosis is made. We hypothesized that patients with radiographic emphysema on computed tomography (CT) scan of the chest would represent an enriched population of patients with a higher prevalence of alpha-1 antitrypsin (AAT) carrier or heterozygous state. Methods We evaluated 250 in-patients with chest computed tomography (CT) findings of emphysema, and per clinical guidelines, all were tested for AAT with Alphakit finger stick blood collection kits. Sampling 250 patients provided power to detect a carrier prevalence of 20% +/- 1.0%. Results A total of 250 patients were recruited of which 53% were male, 91% Caucasian, 7% African American, and 16% active smokers. They smoked an average of 39 packs per year. The prevalence of carrier status (Pi*MS or Pi*MZ) was 6.8% (95% CI (4%, 11%)). The mean forced expiratory volume in one second (FEV-1) was 53%, predicted among Pi*MM patients (n=126) and not significantly different from the Pi*MS group (50%, n=13). 69% of Pi*MM were diagnosed with asthma or COPD, vs. 79% of Pi*MS (n=14) and 100% Pi*MZ (n=3), but the difference was not significant (p=0.4). Conclusion In the population studied, compared to a cohort of patients with abnormal pulmonary function tests (PFTs), radiographically evident emphysema did not identify patients at higher risk of being heterozygous or homozygous for AAT deficiency.

Optical properties of a melt-quenched metal-organic framework glass.

Metal-organic framework (MOF) glasses are characterized by the possession of both inorganic and organic components, linked in a continuous network structure by coordination bonds. To the best of our knowledge, the optical properties of MOF glasses have not been reported until now. In this work, we prepared a transparent bubble-free bulk MOF glass, namely, the ZIF-62 glass (ZnIm2-xbImx), using our newly developed hot-pressing technique, and measured its optical properties. The ZIF-62 glass has a high transmittance (up to 90%) in the visible and near-infrared wavelength ranges, which is comparable to that of many oxide glasses. Using the Becke line nD method, we found that the ZIF-62 glass exhibits a refractive index (1.56) similar to most inorganic glasses, though a lower Abbe number (∼31).

Cannulation of the Femoral Arterial Bypass Cannula Allows Completion of TAVR in Unstable Patients.

When hemodynamic instability occurs during transcatheter aortic valve replacement, peripheral cardiopulmonary bypass is required. The pigtail catheter, initially placed through the femoral artery to direct placement of the valve, is exchanged over a wire for an arterial bypass cannula. Other than time-consuming arterial cut-down procedures in hypotensive patients, there are few techniques described to allow the operator to continue bypass and complete transcatheter aortic valve replacement. This report describes a method to reintroduce the pigtail catheter by puncturing the arterial bypass cannula. This technique allows the operator to support the patient, continue bypass, and successfully place the valve without aborting the procedure.

Diagnosing Meat Allergy After Tick Bite Without Delay.

Galactose-α-1, 3 galactose (α-gal) is a carbohydrate found in mammalian meat. In 2007, it was implicated as a cause of severe hypersensitivity reactions when a study found elevated levels of antibodies directed against this oligosaccharide among patients treated with cetuximab, a monoclonal antibody that contained an α -gal epitope. The majority of these cases were reported in the Southeast United States in a distribution similar to that of Rocky Mountain spotted fever and ehrlichiosis, and that geographic association led researchers to the conclusion that a bite from the Lone Star tick can induce this antibody. Here, we present a case of delayed urticarial angioedema due to a mammalian meat allergy caused by α-gal immunoglobulin E acquired after tick exposures, and the knowledge and patient education required to prevent recurrences. It is estimated that approximately 0.5% to 1.0% of the general population will experience an episode of angioedema in their lifetime, and this case demonstrates why clinicians in areas that are inhabited by ticks, particularly the Lone Star species, should include this cause in their differential.

Postpartum Testing to Detect Persistent Dysglycemia in Women With Gestational Diabetes Mellitus.

The rate of gestational diabetes has doubled, and identifying the 30% with persistent postpartum dysglycemia (prediabetes or diabetes mellitus) is important because low-cost interventions have been proven to prevent overt diabetes mellitus, improve health for women, and potentially decrease the risk for birth defects in future pregnancies. Consensus guidelines continue to recommend a 4- to 12-week postpartum 2-hour oral glucose tolerance test (OGTT) despite persistent reports that only 35% of women complete the test. Physician ordering rates can improve, but the largest barriers to postpartum testing are clearly patient-related. Initiatives to improve OGTT testing rates have been only moderately effective and required allocation of staff time, diverting resources from other clinical areas. Alternative testing models using single-draw tests that bypass patient barriers show promise for improving the diagnosis of postpregnancy dysglycemia. Specifically, evidence is emerging in the pregnant and nonpregnant populations that, compared with the OGTT, the single-draw hemoglobin A1C test may identify more patients with prediabetes, bypasses patient barriers to testing such as the need for fasting, and has less laboratory variation compared with the OGTT or fasting plasma glucose. The risk-benefit focus should shift from comparing individual test performance statistics presuming the OGTT to be the "gold standard" to data reporting the ability of a test to facilitate identification of patients. We review the evidence regarding postpregnancy testing and make recommendations for strategies to improve the identification of dysglycemia and postpregnancy health.

Obstetric medical care in the United States of America.

The current models of obstetric medical care utilized in the United States, how those models fit in with the overall care system, and ways to increase the role of obstetric internists will be reviewed.

Society for maternal and fetal medicine workshop on pregnancy as a window to future health: Clinical utility of classifying women with metabolic syndrome.

Women with preeclampsia, gestational diabetes, and obesity during pregnancy are at risk for medical complications later in life. Therefore, practitioners should identify those who can benefit from early diagnosis and interventions. Metabolic syndrome is a cluster of risk factors including hypertension, elevated triglycerides, low high-density lipoprotein cholesterol, glucose intolerance, and obesity, which also identifies those at risk for cardiovascular disease. Taking the time to classify women with the metabolic syndrome does not necessarily offer risk stratification superior to that offered by identifying the individual components. This article will offer conclusions regarding the need for busy obstetrician/gynecologists to make this classification.

Blood pressure goals and treatment in pregnant patients with chronic kidney disease.

As the age of pregnant women and prevalence of obesity and diabetes are increasing, so is the prevalence of medical disorders during pregnancy, particularly hypertension and the associated CKD. Pregnancy can worsen kidney function in women with severe disease, and hypertension puts them at risk for pre-eclampsia and the associated complications. There are no specific guidelines for hypertension management in this population, and tight control will not prevent pre-eclampsia. Women with end-stage kidney disease should be placed on intense dialysis regimens to improve obstetric outcomes, and angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are best avoided. This article will review the rationale for a management plan that includes a multidisciplinary team to discuss risks and develop a plan before conception, antepartum monitoring for maternal and fetal morbidity, individualization of medical management using medications with established records during pregnancy, and balancing the level of blood pressure control proved to protect kidney function against the potential effects that aggressive blood pressure control could have on the fetal-placental unit.