Time to therapy and safety of testicular tissue cryopreservation in children undergoing gonadotoxic treatment or hematopoietic stem cell transplant

BACKGROUND

With the use of multimodal treatments and hematopoietic stem cell transplant, the majority of children diagnosed with malignancies and hematologic diseases are now surviving into adulthood. Due to the gonadotoxic effects and potential for future infertility associated with many of these treatments, fertility counseling with sperm cryopreservation prior to starting therapy is the standard of care for post-pubertal males. Unfortunately, the options are limited for pre-pubertal patients or those unable to provide a specimen. Testicular tissue cryopreservation (TTC) is an investigational method to surgically obtain germ cells from testicular tissue and potentially restore future spermatogenesis. While TTC has been shown to be safe, little is reported on the time to treatment following the procedure to ensure adequate wound healing and avoid delays in definitive therapy.

OBJECTIVES

The primary outcome was the time to initiation of treatment following TTC. Secondary outcomes were complication rates, delays in treatment due to TTC, and presence of germ cells.

METHODS

We conducted a single-institution retrospective cohort study of patients undergoing TTC between 2017 and 2023. Patients at significant risk for treatment related infertility based on established criteria were eligible for TTC. Patients were excluded if they received their oncology or hematology care elsewhere. All patients were enrolled in an IRB approved research protocol with 75% of the tissue submitted for cryopreservation and 25% for research purposes. Time to therapy was defined as the first receipt of gonadotoxic treatment following TTC.

RESULTS

A total of 122 patients (53 = malignant, 69 = non-malignant) underwent TTC with a median age of 5.9 years (IQR 2.3-9.35). Germ cells were identified in 115 (94%) specimens. A total of 109 (89%) patients underwent concomitant procedures. The median time to initiation of therapy was 5 (IQR 1.0-7.0) and 7 days (IQR 6.0-13.0) for malignant and non-malignant disease, respectively. The 30-day surgical complication rate was 2.5% and was similar between malignant vs non-malignant diagnoses (p = 0.58). All surgical complications were managed non-operatively. No patients had a delay in definitive treatment due to concern for wound healing or complications.

DISCUSSION

Our surgical complication rates are similar to previous studies and are not affected by the time to treatment following TTC. Limitations of the study are its retrospective design, single institution, and short-term follow up.

CONCLUSION

TTC can be performed safely, efficiently, and in conjunction with other necessary procedures without resulting in delays of definitive treatment. TTC affords the opportunity for fertility preservation in children who have no other options.

One and done: Feasibility and Safety of Primary Ureteroscopy in a Pediatric Population

BACKGROUND

Pediatric urolithiasis has been increasing at rate of 4-10 % annually in the United States, most notably within adolescents and females. A significant number of patients will require surgical management of their stones. Primary ureteroscopy (URS) affords the opportunity to treat stones under a single anesthetic with lower re-treatment rates or anatomical and stone characteristic limitations compared to shockwave lithotripsy. Previous studies evaluating primary URS have been largely underpowered, are limited by stone location, and/or are not representative of the stone population in the United States.

OBJECTIVES

Primary study outcomes were the success of primary URS and patient characteristics associated with success. Secondary outcomes were the stone-free rate (SFR), 30-day emergency department (ED) visits, 30-day readmissions, and complications.

METHODS

We performed a retrospective cohort study of patients less than 18 years of age from 2011 to 2023 who underwent primary URS. Patients were excluded if a ureteral stent was placed prior to URS or diagnostic URS was performed. A successful primary URS was considered if access to the ureter was obtained and treatment of the stone(s) completed. In failed primary URS, a ureteral stent was placed for staged management.

RESULTS

A total of 196 patients were included and primary URS was performed or attempted on 224 renal units. The median age was 15.8 (IQR 13.4-16.9) years and median follow up 8.4 (IQR 1.1-24.6) months. The success rate of primary URS was 79 %. No significant characteristics were appreciated for successful primary URS based on: overall age, <14 vs > 14 years of age, sex, body mass index, history of stones, history of endourologic procedures, preoperative alpha blockade, location of stone(s), multiple stones, type of URS, or acute treatment. In successful primary URS, the SFR was 88 % with stone size (p = 0.0001) the only predictor of having residual stones. The 30-day ED rate was 21.4 %, 30-day unplanned readmission rate was 12.5 %, and complication rate was 7.5 %. No long-term complications were appreciated.

DISCUSSION

Our success of primary URS compares favorably to previously published literature. Our SFR rate, 30-day ED visits, 30-day unplanned readmission, and complication rates are similar to other studies. Limitations of the study are its retrospective design, selection bias, and intermediate follow-up.

CONCLUSIONS

Primary URS can be completed safely in the majority of pediatric patients without any patient characteristics associated with success. We advocate for primary URS when possible due to the excellent SFR and potential of treating stones under a single anesthetic.

Micro-kelvin temperature-stable system for biocalorimetry applications

Achieving micro-kelvin (µK) temperature stability is critical for many calorimetric applications. For example, sub-nanowatt resolution biocalorimetry requires stabilization of the temperature of the calorimeter to µK levels. Here, we describe how µK temperature stability can be accomplished in a prototypical calorimetric system consisting of two nested shields and a suspended capillary tube, which is well suited for biocalorimetry applications. Specifically, we show that by employing nested shields with µTorr-levels of vacuum in the space between them as well as precise feedback control of the temperature of the shields (performed using high-resolution temperature sensors), the effect of ambient temperature fluctuations on the inner shield and the capillary tube can be attenuated by ∼100 dB. We also show that this attenuation is key to achieving temperature stabilities within ±1 and ±3 µK (amplitude of oscillations) for the inner shield and the capillary tube sensor, respectively, measured in a bandwidth of 1 mHz over a period of 10 h at room temperature (∼20.9 ± 0.2 °C). We expect that the methods described here will play a key role in advancing biocalorimetry.

Transcription factor Tcf21 modulates urinary bladder size and differentiation

Urinary bladder organogenesis requires coordinated cell growth, specification, and patterning of both mesenchymal and epithelial compartments. Tcf21, a gene that encodes a helix-loop-helix transcription factor, is specifically expressed in the mesenchyme of the bladder during development. Here we show that Tcf21 is required for normal development of the bladder. We found that the bladders of mice lacking Tcf21 were notably hypoplastic and that the Tcf21 mutant mesenchyme showed increased apoptosis. There was also a marked delay in the formation of visceral smooth muscle, accompanied by a defect in myocardin (Myocd) expression. Interestingly, there was also a marked delay in the formation of the basal cell layer of the urothelium, distinguished by diminished expression of Krt5 and Krt14. Our findings suggest that Tcf21 regulates the survival and differentiation of mesenchyme cell-autonomously and the maturation of the adjacent urothelium non-cell-autonomously during bladder development.

Efficacy, Safety, Pharmacokinetics, and Immunogenicity of DRL-Trastuzumab Versus Herceptin in Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer: A Randomized Controlled Trial

PURPOSE

Dr Reddy's Laboratories Trastuzumab (DRL_TZ) is a biosimilar to Herceptin under development. The present study was conducted to evaluate efficacy, safety, pharmacokinetics (PKs), and immunogenicity of DRL_TZ in comparison with the reference medicinal product (RMP) along with concomitant weekly paclitaxel in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC).

METHODS

This was a randomized, double-blind study in female patients with HER2-positive MBC, randomly assigned in a 1:1 ratio to receive either DRL_TZ or the RMP, that is, an innovator product sourced from the European region, along with additional chemotherapy, as first-line treatment for up to 24 weeks. The primary end point was the best overall response rate (ORR) as per RECIST 1.1 criteria. Progression-free survival rate at 6 months (PFS6), safety, immunogenicity, and PK parameters were assessed as secondary end points.

RESULTS

A total of 164 patients were randomly assigned to receive either DRL_TZ or the RMP. Best ORR in the per-protocol population was comparable, 91.9% (93.3% CI, 83.2 to 96.3) versus 82.1% (93.3% CI, 72.0 to 89.1) in DRL_TZ and RMP arms, respectively; the difference between the arms was 9.8% with a 93.3% CI of -1.3 to 20.8. The PFS6 rate, safety, PK profile, and antidrug antibody incidence were comparable. An additional 44 patients were recruited in the postrandomization phase, in an open-label manner, and started on DRL_TZ to generate more data on efficacy, safety, and immunogenicity. The additional data with DRL_TZ, when pooled, were similar to the RMP data.

CONCLUSION

DRL_TZ was found to have similar efficacy and comparable safety, PK, and immunogenicity profiles as the RMP.

A Case of Pernicious Anemia Presenting With Severe Hemolysis

Vitamin B12 deficiency is a well-known and overall common disease. While the etiology of vitamin B12 deficiency varies from post-surgical changes to inadequate dietary consumption, pernicious anemia should be considered as it is a common cause. Pernicious anemia is an autoimmune atrophic gastritis impairing the absorption of vitamin B12. Manifestations include neurological changes, macrocytic anemia, glossitis, and nail changes. Hemolytic anemia is an unusual complication of vitamin B12 deficiency and an even more unusual initial presentation. This case identifies a patient with previously undiagnosed pernicious anemia with severe vitamin B12 deficiency compounded by hemolytic anemia as the presenting symptom. Overall, this case highlights the importance of considering vitamin B12 deficiency-related hemolytic anemia and the need for further research into the causes and pathophysiology of vitamin B12-induced hemolysis due to its potential for fatal outcomes despite being easily treatable with cost-effective methods to treat.

Surface Phonon Polariton-Mediated Near-Field Radiative Heat Transfer at Cryogenic Temperatures

Recent experiments, at room temperature, have shown that near-field radiative heat transfer (NFRHT) via surface phonon polaritons (SPhPs) exceeds the blackbody limit by several orders of magnitude. Yet, SPhP-mediated NFRHT at cryogenic temperatures remains experimentally unexplored. Here, we probe thermal transport in nanoscale gaps between a silica sphere and a planar silica surface from 77-300 K. These experiments reveal that cryogenic NFRHT has strong contributions from SPhPs and does not follow the T^{3} temperature (T) dependence of far-field thermal radiation. Our modeling based on fluctuational electrodynamics shows that the temperature dependence of NFRHT can be related to the confinement of heat transfer to two narrow frequency ranges and is well accounted for by a simple analytical model. These advances enable detailed NFRHT studies at cryogenic temperatures that are relevant to thermal management and solid-state cooling applications.

Electrical Conductance and Thermopower of β-Substituted Porphyrin Molecular Junctions─Synthesis and Transport

Molecular junctions offer significant potential for enhancing thermoelectric power generation. Quantum interference effects and associated sharp features in electron transmission are expected to enable the tuning and enhancement of thermoelectric properties in molecular junctions. To systematically explore the effect of quantum interferences, we designed and synthesized two new classes of porphyrins, P1 and P2, with two methylthio anchoring groups in the 2,13- and 2,12-positions, respectively, and their Zn complexes, Zn-P1 and Zn-P2. Past theory suggests that P1 and Zn-P1 feature destructive quantum interference in single-molecule junctions with gold electrodes and may thus show high thermopower, while P2 and Zn-P2 do not. Our detailed experimental single-molecule break-junction studies of conductance and thermopower, the latter being the first ever performed on porphyrin molecular junctions, revealed that the electrical conductance of the P1 and Zn-P1 junctions is relatively close, and the same holds for P2 and Zn-P2, while there is a 6 times reduction in the electrical conductance between P1 and P2 type junctions. Further, we observed that the thermopower of P1 junctions is slightly larger than for P2 junctions, while Zn-P1 junctions show the largest thermopower and Zn-P2 junctions show the lowest. We relate the experimental results to quantum transport theory using first-principles approaches. While the conductance of P1 and Zn-P1 junctions is robustly predicted to be larger than those of P2 and Zn-P2, computed thermopowers depend sensitively on the level of theory and the single-molecule junction geometry. However, the predicted large difference in conductance and thermopower values between Zn-P1 and Zn-P2 derivatives, suggested in previous model calculations, is not supported by our experimental and theoretical findings.

Real-world outcomes of diffuse large B-cell lymphoma in the biosimilar era

Background

Diffuse large B-cell lymphoma (DLBCL) is an aggressive and the most common type of non-Hodgkin lymphoma (NHL). The clinical use of rituximab has improved the treatment response and survival of patients with DLBCL. The introduction of rituximab biosimilar into healthcare system has helped in providing a cost-effective treatment to B-cell lymphoid malignancies as standard of care and has improved access to patients worldwide. The aim of this study was to observe the real-world effectiveness and safety of Reditux™ and Ristova® in DLBCL patients.

Methods

Observational study in adults with DLBCL receiving Reditux™ or Ristova® across 29 centers in India (2015-2022). Effectiveness and safety were assessed up to 2 years after first dose.

Results

Out of 1,365 patients considered for analysis, 1,250 (91.6%) were treated with Reditux™ and 115 (8.42%) with Ristova®. At 2 years, progression-free survival (PFS) 69% [hazard ratio (HR), 1.16; 95% CI, 0.80-1.67], overall survival (OS) 78.7% (HR, 1.20; 95% CI, 0.78-1.86), response rates, quality of life (QoL), and overall safety in both the cohorts were comparable. The best overall response rate (BORR) at 6 months was comparable with no statistically significant differences between the Reditux™ and the Ristova® cohorts (89.2% vs. 94.3%). In multivariate analysis, BCL-2 and VAS were significant prognostic factors for PFS.

Conclusion

Reditux™ and Ristova® were comparable in real-world setting.

Clinical Trial Registration

ISRCTN registry, identifier (ISRCTN13301166).

Pyridoxine Deficiency and Neurologic Dysfunction: An Unlikely Association

Pyridoxine deficiency is a prevalent condition in the United States that primarily affects patients with alcohol use disorder. The presentation of this condition is very nonspecific and commonly presents with a constellation of symptoms including peripheral neuropathy, stomatitis, dermatitis, confusion, depression, encephalopathy, and seizures. Over half of these patients have associated alcohol use disorder, which causes pyridoxine deficiency due to the breakdown of pyridoxal phosphate during ethanol metabolism in the liver. As an important cofactor in the synthesis of γ-aminobutyric acid (GABA), deficient levels of pyridoxine may lower the seizure threshold due to reduced GABA-mediated inhibition. This case details a 57-year-old male with chronic alcoholism and a history of seizures who developed episodes of myoclonic jerks, tremors, anxiety, and neuropathy whose symptoms persisted even while on anti-epileptic medication. He was found to have pyridoxine deficiency and had full resolution of symptoms shortly after the administration of vitamin B6 supplementation. Pyridoxine deficiency may lead to severe neurologic disorders such as encephalopathy and seizures. Hence, it is important to consider pyridoxine deficiency in the workup of neurologic complaints, especially in high-risk patients.

Diffuse Large B-cell Lymphoma of the Orbit With Intracranial Extension: A Rare Entity

Primary diffuse large B-cell lymphoma of the orbit is a rare diagnosis that accounts for less than 1% of all non-Hodgkin's lymphoma (NHL) cases. We present here the case of a middle-aged woman with a past medical history of intellectual delay and hypothyroidism who presented with a large diffusely infiltrating mass of the left orbit. A biopsy of the lesion during the patient's hospitalization confirmed a diagnosis of diffuse, large B-cell lymphoma. Due to extensive local invasion, she was deemed a poor surgical candidate. While inpatient, she was started on systemic chemotherapy and discharged with close follow-up planned with the oncologic and surgical teams.

Role of Tranexamic Acid in Palliative Control of Bleeding in End-Stage Head and Neck Cancer: A Case Report

Tumor-related bleeding is a common manifestation of end-stage head and neck cancer, and it can have a significant impact on a patient's quality of life. Tranexamic acid is an anti-fibrinolytic agent that has been shown to effectively control bleeding and reduce the need for transfusions in various hemorrhagic conditions. Here, we present the case of a patient with end-stage head and neck cancer experiencing recurrent episodes of bleeding, who was able to successfully achieve hemostasis after being treated with tranexamic acid. This case report highlights the role of tranexamic acid as a palliation agent that can help control the unpleasant bleeding symptoms of end-stage head and neck cancer and provide a better quality of life for patients.

Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Long-Term Male Sexual Function and Fecal Incontinence Outcomes for Adult Patients with Hirschsprung Disease or Anorectal Malformation

BACKGROUND

This study sought to characterize sexual function and fecal incontinence related quality of life (QOL) outcomes for adult males with anorectal malformation (ARM) or Hirschsprung's Disease (HD).

METHODS

We conducted a cross-sectional survey study of male patients ≥18 years with ARM or HD. Patients were identified from our institutional database, contacted and consented by telephone, and sent a REDCap survey via email. The International Index of Erectile Function (IIEF-5) and Male Sexual Health Questionnaire (MSHQ) evaluated erectile dysfunction (ED) and ejaculatory dysfunction (EjD), respectively. The Cleveland Clinic Incontinence Score (CCIS) and the Fecal Incontinence Quality of Life Scale (FIQLS) assessed fecal incontinence-related outcomes. A linear regression analysis of IIEF-5 scores compared to CCIS scores was used to evaluate for an association between ED and incontinence.

RESULTS

Of 63 patients contacted, 48 completed the survey. The median age for respondents was 22.5 years (IQR 20-25). There were 19 patients with HD and 29 patients with ARM. On the IIEF-5 survey, 35.3% report some level of ED. On the MSHQ-EjD survey, the median score was 14 out of 15 (IQR 10.75-15), indicating few EjD concerns. The median CCIS was 5 (IQR 2.25-7.75) and the median FIQL scores ranged from 2.7 to 3.5 depending on the domain assessed, demonstrating some QOL challenges secondary to fecal incontinence. On linear regression analysis, IIEF-5 and CCIS scores were weakly associated (B = -0.55, p = 0.045).

CONCLUSIONS

Male adult patients with ARM or HD may have ongoing concerns with sexual function and fecal incontinence.

LEVEL OF EVIDENCE

Level 4.

TYPE OF STUDY

Cross-Sectional Survey Study.

The Double-Edged Sword: Naloxone-Induced Noncardiogenic Pulmonary Edema

Naloxone-induced noncardiogenic pulmonary edema (NCPE) is a scarcely reported side effect that can occur after naloxone administration. We present a case of a 46-year-old male who presented to the emergency department for further management of an opioid overdose, who developed acute hypoxic respiratory failure after several doses of naloxone. The rapid deterioration of the patient's respiratory status required increased supplemental oxygen, with plane film radiography suggesting diffuse pulmonary edema. This case emphasizes the importance of understanding the significant side effects of a lifesaving drug and the implications they carry now that naloxone is available without prescription.

Non-Cutaneous Visceral Kaposi's Sarcoma Diagnosis Confounded by Mycobacterium Avium Complex Lymphadenitis

Kaposi's sarcoma (KS) is an Acquired Immune Deficiency Syndrome (AIDS)-defining illness, with cutaneous KS being a more common presentation. Visceral involvement, particularly in the gastrointestinal (GI) tract, without cutaneous involvement, is rare. Consisting of generally non-specific symptoms, GI-KS can have potentially fatal outcomes, including hemorrhage or perforation, making prompt diagnosis and treatment imperative. Our case describes a 31-year-old male with AIDS who presented with a neck mass and purulent, bloody rectal drainage. The neck mass was biopsied and identified as caseated necrotic cervical lymphadenitis caused by Mycobacterium avium complex (MAC). The patient presented with rectal drainage, and additional abdominal necrotic lymph nodes were discovered on CT. A subsequent colonoscopy was completed, confirming the diagnosis of visceral KS. Delayed diagnosis of visceral KS can lead to an extensive, widespread disease requiring adjuvant and prolonged treatment. Prompt diagnosis can reduce morbidity and mortality. This case aims to shed light on a rare presentation of a common disease state with potentially fatal complications and emphasizes the importance of maintaining a broad differential diagnosis.

Probing the Limits to Near-Field Heat Transfer Enhancements in Phonon-Polaritonic Materials

Near-field radiative heat transfer (NFRHT) arises between objects separated by nanoscale gaps and leads to dramatic enhancements in heat transfer rates compared to the far-field. Recent experiments have provided first insights into these enhancements, especially using silicon dioxide (SiO₂) surfaces, which support surface phonon polaritons (SPhP). Yet, theoretical analysis suggests that SPhPs in SiO₂ occur at frequencies far higher than optimal. Here, we first show theoretically that SPhP-mediated NFRHT, at room temperature, can be 5-fold larger than that of SiO₂, for materials that support SPhPs closer to an optimal frequency of 67 meV. Next, we experimentally demonstrate that MgF₂ and Al₂O₃ closely approach this limit. Specifically, we demonstrate that near-field thermal conductance between MgF₂ plates separated by 50 nm approaches within nearly 50% of the global SPhP bound. These findings lay the foundation for exploring the limits to radiative heat transfer rates at the nanoscale.

Paraneoplastic Scleroderma: A Case Report of Systemic Sclerosis in the Setting of Pulmonary Adenocarcinoma

A 42-year-old female with a past medical history significant for scleroderma and extensive tobacco use presented with a dry cough and pleuritic chest pain. Further workup was significant for leukocytosis, macrocytic anemia, left lower lung mass, bilateral supraclavicular, hilar, and mediastinal lymphadenopathy. After a comprehensive rheumatologic workup was completed, the patient was found to have strongly positive antinuclear antibody (ANA) and negative scleroderma-specific antibodies with fluorescent ANA indicating a nucleolar pattern. We present a case of paraneoplastic scleroderma in the setting of lung adenocarcinoma which emphasizes the bidirectional relationship that exists between malignancy and rheumatic diseases.

Acute Onset Lactic Acidosis Secondary to Linezolid

Linezolid has been the mainstay of treatment for multidrug-resistant Gram-positive bacteria. Common adverse effects with linezolid include diarrhea, nausea, headache, and bone marrow suppression. A less common and understudied side effect is lactic acidosis. This study describes a 19-year-old man with linezolid-induced lactic acidosis (LILA). The patient was admitted for the management of acute decompensated systolic heart failure, which improved on guideline-directed medication therapy (GDMT). During hospitalization, he developed an erythematous weeping cellulitis infection of his right lower extremity and was started on linezolid 600 mg every 12 hours with wound and blood cultures collected. After one day of treatment with linezolid, lactic acid levels acutely increased from 1.8 mmol/L to 5 mmol/L without any other interventions. Suspecting possible LILA, linezolid was transitioned to cephalexin with a reduction of lactic acid to 2.4 mmol/L, one day following linezolid cessation. After two days of linezolid cessation, lactic acid levels decreased to 1.9 mmol/L. Lactic acidosis can have profound hemodynamic consequences for patients, including death. A meta-analysis study of 35 articles with 47 patients (28 males, 18 females, and one non-binary) was done, which found a 25.5% mortality rate associated with LILA. Due to this high mortality, having a greater understanding of the associated risk factors with LILA is very important. This case study aims to inform clinicians of the potential harmful side effects associated with linezolid, as well as the understudied risk factors involved in LILA that are needed to prevent its occurrence.

Clinical Approach to Euvolemic Hyponatremia

Euvolemic hyponatremia is frequently encountered in hospitalized patients and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause in most patients. SIADH diagnosis is confirmed by decreased serum osmolality, inappropriately elevated urine osmolality (>100 mosmol/L), and elevated urine sodium (Na) levels. Patients should be screened for thiazide use and adrenal or thyroid dysfunction should be ruled out before making a diagnosis of SIADH. Clinical mimics of SIADH like cerebral salt wasting and reset osmostat should be considered in some patients. The distinction between acute (<48 hours) versus chronic (>48 hours or without baseline labs) hyponatremia and clinical symptomatology are important to initiate proper therapy. Acute hyponatremia is a medical emergency and osmotic demyelination syndrome (ODS) occurs commonly when rapidly correcting any chronic hyponatremia. Hypertonic (3%) saline should be used in patients with significant neurologic symptoms and maximal correction of serum Na level should be limited to <8 mEq over 24 hours to prevent the ODS. Simultaneous administration of parenteral desmopressin is one of the best ways to prevent overly rapid Na correction in high-risk patients. Free water restriction combined with increased solute intake (e.g., urea) is the most effective therapy to treat patients with SIADH. 0.9% saline acts as a hypertonic solution in patients with hyponatremia and should be avoided in the treatment of SIADH due to rapid fluctuations in serum Na levels. Dual effects of 0.9% saline resulting in rapid correction of serum Na during infusion (inducing ODS) and post-infusion worsening of serum Na levels are described in the article with clinical examples.

Thrombotic Storm Induced by Rituximab in a Patient With Pemphigus Vulgaris

Thrombotic storm is a rare hypercoagulable condition characterized by a clinical trigger causing extensive thrombotic events affecting multiple vessels over a short period of time. We present a case of thrombotic storm that developed in a patient who received rituximab therapy. The patient presented to the hospital with dyspnea and shortness of breath and was subsequently diagnosed with extensive thrombotic burden including multiple deep vein thrombi and pulmonary emboli. Hypercoagulable workup for the thrombotic storm was unrevealing with the only identifiable trigger being the rituximab infusion. The patient was treated successfully with anticoagulation and discontinuation of rituximab. There are very few reports highlighting thrombotic events as a complication of rituximab therapy. We aim to increase recognition of thrombotic storm as a potential complication of receiving rituximab therapy.

Hemophagocytic Lymphohistiocytosis and Clostridium difficile Infection: A Diagnostic Dilemma

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition that often goes underdiagnosed because of broad and non-specific symptomatology, usually consisting of fever, hepatosplenomegaly, and multiorgan failure. This disorder can be driven by genetic components (primary) or acquired (secondary) causes related to infectious, autoimmune, or malignant processes. HLH pathogenesis derives from overactive and dysregulated immune system responses. This disorder often goes misdiagnosed because of similar clinical and laboratory findings to septicemia. Cases of HLH most commonly coexist with Epstein-Barr virus (EBV). Clostridium difficile (C. difficile) infection causing HLH has also rarely been described in the literature. A firm knowledge of HLH association with clostridial infection is essential to recognize. A presumed diagnosis of HLH in a decompensating patient may prompt the initiation of appropriate treatment earlier and improve clinical outcomes. We discuss the diagnostic and management difficulties associated with these concurrent conditions.

Intraoperative laser angiography in bladder exstrophy closure: A simple technique to monitor penile perfusion

BACKGROUND

The successful repair of Bladder Exstrophy remains one of the biggest challenges in Pediatric Urology. The primary focus has long been on the achievement of urinary continence. Historically there has been less focus on early penile outcomes. To this end we have incorporated penile perfusion testing using intraoperative laser angiography in to our operative approach.

OBJECTIVE

We hypothesize that assessment of penile perfusion at various points in the procedure is a feasible technique that may assist in decision making during the repair of this complex condition. This will reduce the risk of tissue compression and potential loss of penile tissue that has been reported to occur as a complication of the procedure.

STUDY DESIGN

Consecutive patients presenting with bladder exstrophy were evaluated at four stages of their operation (i.e. following induction of anesthesia, after bladder mobilization, following internal rotation of the pubis and at the end of the procedure) by infusing indocyanine green (ICG) at a dose of 1 mg per 10 kg body weight. Measurements were taken at 80 s post infusion and the medial thigh served as the reference control. Postoperative penile viability was evaluated by visual inspection and palpation three months following the procedure.

RESULTS

Eight consecutive patients were included in this study. Perfusion was easy to measure and posed no significant technical difficulties. Penile perfusion increased slightly following bladder dissection. Internal rotation of the hips with apposition of the symphysis pubis resulted in an average 50% reduction in penile blood flow. Patients undergoing CPRE experienced an additional mean 33% drop in blood flow. In all eight cases the penis was symmetric and healthy with no sign of tissue loss at three months follow up.

CONCLUSIONS

This pilot study demonstrates that the measurement of penile perfusion utilizing intraoperative laser angiography is easy to employ and should be considered a reasonable adjunct to tissue assessment in this complex condition. Marked reduction in penile blood flow may occur without any outward clinical signs. Penile perfusion is markedly reduced by apposition of the symphysis pubis and, in the immediate postoperative period, there may be further reduction in penile blood flow with CPRE as opposed to a staged repair. Future correlation with measures of penile viability and function are needed to define the clinical utility of this modality.

Preventing Vitamin B6-Related Neurotoxicity

BACKGROUND

Vitamin B6 is essential for life and plays a critical role in many biochemical and physiological processes in the human body. The term B6 collectively refers to 6 water-soluble vitamers, and only the pyridoxal 5'-phosphate (PLP) serves as the biologically active form. A plasma PLP concentration above 30 nmol/L (7.4 μg/L) is indicative of an adequate vitamin B6 status for all age and sex groups. The currently recommended daily allowance of B6 (1.5-2 mg/d) from dietary sources frequently results in inadequate B6 status (<20 nmol/L or 5 μg/L) in many elderly patients and patients with comorbid conditions. PLP-based supplements are preferred and should be administered weekly in low doses (50-100 mg) to maintain a stable serum PLP level between 30 and 60 nmol/L or 7.4 and 15 μg/L.

AREAS OF UNCERTAINTY

It is challenging for physicians to prescribe a safe dose of B6 supplements because of the narrow therapeutic index. The association between elevated levels of pyridoxine and neuropathy is not well established. PLP-based supplements are shown to be least neurotoxic, but further clinical trials are needed to establish the long-term safety in high doses.

DATA SOURCES

PubMed search of randomized control trials and meta-analyses.

THERAPEUTIC OPINION

Plasma B6 levels should be ordered as a part of workup of any unexplained anemia before labeling as "anemia of chronic disease." B6 supplementation is also crucial in the management of chronic Mg deficiency resistant to therapy. When B6 is administered daily in supraphysiologic doses, there is a potential for the development of neurotoxicity (typically at levels >100 nmol/L or 25 μg/L). PLP-based supplements are preferred over pyridoxine supplements because of minimal neurotoxicity observed in neuronal cell viability tests. Since B6 metabolites have a long half-life, weekly administration is preferred over daily use to prevent toxicity.

Enhancement and Saturation of Near-Field Radiative Heat Transfer in Nanogaps between Metallic Surfaces

Near-field radiative heat transfer (NFRHT) between planar metallic surfaces was computationally explored over five decades ago by Polder and van Hove [Phys. Rev. B 4, 3303 (1971)PLRBAQ0556-280510.1103/PhysRevB.4.3303]. These studies predicted that, as the gap size (d) between the surfaces decreased, the radiative heat flux first increases by several orders of magnitude until d is ∼100  nm after which the heat flux saturates. However, despite both the fundamental and practical importance of these predictions, the combined enhancement and saturation of NFRHT at small gaps in metallic surfaces remains experimentally unverified. Here, we probe NFRHT between planar metallic (Pt, Au) surfaces and show that RHT rates can exceed the far-field rate by over a thousand times when d is reduced to ∼25  nm. More importantly, we show that for small values of d RHT saturates due to the dominant contributions from transverse electric evanescent modes. Our results are in excellent agreement with the predictions of fluctuational electrodynamics and are expected to inform the development of technologies such as near-field thermophotovoltaics, radiative heat-assisted magnetic recording, and nanolithography.

Refractory Thrombotic Thrombocytopenic Purpura to Therapeutic Plasma Exchange

Thrombotic thrombocytopenic purpura (TTP) is a rare, potentially fatal hematologic disorder characterized by microangiopathic hemolytic anemia, thrombocytopenia, and varying signs of visceral ischemia secondary to microvascular thrombosis. TTP is caused by a severe deficiency of ADAMTS13, a protease enzyme responsible for cleaving von Willebrand-factor (vWF) multimers. First-line therapy with plasmapheresis has increased survival rates immensely; however, there are few reported cases that are refractory to standardized treatment. We describe two cases of refractory TTP successfully managed with the addition of caplacizumab, an anti-von Willebrand factor immunoglobulin fragment that inhibits the interaction of vWF multimers with platelets.

Clinical Approach to Nosocomial Bacterial Sepsis

Bacterial sepsis and septic shock are associated with a high mortality, and when clinically suspected, clinicians must initiate broad-spectrum antimicrobials within the first hour of diagnosis. Thorough review of prior cultures involving multidrug-resistant (MDR) pathogens along with other likely pathogens should be performed to provide an appropriate broad-spectrum empiric antibiotic coverage. The appropriate antibiotic loading dose followed by individualized modification of maintenance dose should be implemented based on the presence of hepatic or renal dysfunction. Use of procalcitonin is no longer recommended to determine need for initial antibacterial therapy and for de-escalation. Daily reevaluation of appropriateness of treatment is necessary based on the culture results and clinical response. All positive cultures should be carefully screened for possible contamination or colonization, which may not represent the true organism causing the sepsis. Culture negative sepsis accounts for one-half of all cases, and de-escalation of initial antibiotic regimen should be done gradually in these patients with close monitoring.

Two PerPLEXing Cases of Hashimoto’s Encephalopathy Unresponsive to Steroid and Intravenous Immunoglobulin Therapy

Hashimoto’s encephalopathy is a nebulous entity over which much controversy exists. Often referred to as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), it describes a myriad of neurological sequelae that typically are observed to occur in patients with the presence of thyroid antibodies. We aim to raise clinical awareness of this seldom diagnosed entity as a potential etiology for altered mental status in patients who present with supporting clinical features and elevated thyroid antibodies. While steroid responsiveness is deemed a typical presenting feature of this medical condition, our cases aim to describe two cases that required escalation of therapy to intravenous immunoglobulins, and ultimately, plasmapheresis therapy for improvement in their clinical status. Our patients had a dramatic improvement in their mentation within three to four sessions of plasmapheresis, improving rapidly toward their baseline. Such a dramatic improvement, coupled with the corresponding reduction in their thyroid antibody titer supports the diagnosis of Hashimoto's encephalopathy and highlights the importance of having a low clinical threshold for the diagnosis of this entity in patients who, despite extensive evaluation, reveal no apparent cause for their altered mental status.

Prolonged Orbital Relaxation by Locally Modified Phonon Density of States for the SiV^{-} Center in Nanodiamonds

Coherent quantum systems are a key resource for emerging quantum technology. Solid-state spin systems are of particular importance for compact and scalable devices. However, interaction with the solid-state host degrades the coherence properties. The negatively charged silicon vacancy center in diamond is such an example. While spectral properties are outstanding, with optical coherence protected by the defects symmetry, the spin coherence is susceptible to rapid orbital relaxation limiting the spin dephasing time. A prolongation of the orbital relaxation time is therefore of utmost urgency and has been tackled by operating at very low temperatures or by introducing large strain. However, both methods have significant drawbacks: the former requires use of dilution refrigerators and the latter affects intrinsic symmetries. Here, a novel method is presented to prolong the orbital relaxation with a locally modified phonon density of states in the relevant frequency range, by restricting the diamond host to below 100 nm. Subsequently measured coherent population trapping shows an extended spin dephasing time compared to the phonon-limited time in a pure bulk diamond. The method works at liquid helium temperatures of few Kelvin and in the low-strain regime.

Inpatient Management of Encephalopathy

Unexplained encephalopathy is a common occurrence in tertiary care centers and neurologic disorders should be considered after ruling out the infectious, toxic and metabolic etiologies. Neuroimaging combined with a thorough history and examination is often helpful in ruling out stroke and fulminant demyelinating encephalopathies. Autoimmune encephalopathy should be suspected in any patient with unexplained acute or subacute onset encephalopathy or rapidly progressing dementia. Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is the most studied form and Hashimoto encephalitis is the most controversial form of autoimmune encephalopathies. Obtaining a combined serum and Cerebrospinal fluid (CSF) autoantibody testing will increase the diagnostic yield of autoimmune and paraneoplastic encephalitis. When diagnosing NMDA receptor antibodies CSF is always more sensitive than serum and in contrast, voltage-gated potassium channel (VGKC) complex antibodies are more readily detectable in serum than in CSF. Neural-specific antibody tests frequently result after several weeks and treatment should be administered without a significant delay to prevent brain damage. Autoimmune encephalitis is often treatment responsive when immunotherapy (glucocorticoids, intravenous immune globulin, plasma exchange) is used in various combinations. The absence of inflammatory markers and autoantibodies in the serum or CSF may not rule out the possibility of paraneoplastic encephalopathies.

Quantitative Mapping of Unmodulated Temperature Fields with Nanometer Resolution

Quantitative mapping of temperature fields with nanometric resolution is critical in various areas of scientific research and emerging technology, such as nanoelectronics, surface chemistry, plasmonic devices, and quantum systems. A key challenge in achieving quantitative thermal imaging with scanning thermal microscopy (SThM) is the lack of knowledge of the tip-sample thermal resistance (R_TS), which varies with local topography and is critical for quantifying the sample temperature. Recent advances in SThM have enabled simultaneous quantification of R_TS and topography in situations where the temperature field is modulated enabling quantitative thermometry even when topographical features cause significant variations in R_TS. However, such an approach is not applicable to situations where the temperature modulation of the device is not readily possible. Here we show, using custom-fabricated scanning thermal probes (STPs) with a sharp tip (radius ∼25 nm) and an integrated heater/thermometer, that one can quantitatively map unmodulated temperature fields, in a single scan, with ∼7 nm spatial resolution and ∼50 mK temperature resolution in a bandwidth of 1 Hz. This is accomplished by introducing a modulated heat input to the STP and measuring the AC and DC responses of the probe's temperature which allow for simultaneous mapping of the tip-sample thermal resistance and sample surface temperature. The approach presented here─contact resistance resolved scanning thermal microscopy (CR-SThM)─can greatly facilitate temperature mapping of a variety of microdevices under practical operating conditions.

Outcomes according to channel type for continent catheterizable channels in patients undergoing simultaneous urinary and fecal reconstruction

INTRODUCTION

When creating a continent catheterizable channel (CCC) the choice of bowel segment used as the conduit should be tempered with the morbidity associated with it. The split-appendix technique allows the creation of both a urinary and fecal CCC without the need for a bowel anastomosis. However, there is concern that by splitting the appendix there is compromise to its blood supply and may affect outcomes. We aim to compare what affect the bowel segment used for urinary and fecal CCCs has on perioperative and long-term outcomes in patients undergoing simultaneous urinary and fecal reconstruction.

METHODS

A retrospective review was performed analyzing all patients that underwent simultaneous continent catheterizable urinary and fecal CCC between the years 2010-2016. Patient demographics, channel characteristics, perioperative complications and clinical success rate were analyzed.

RESULTS

A total of 106 patients were identified that had simultaneous fecal and urinary CCC created at time of reconstruction. For urinary CCC, there were 64 patients (60.4%) that underwent a split-appendix technique, 27 patients (25.4%) underwent a Monti, and 15 patients (14.2%) had the appendix used only for the urinary channel. Those patients undergoing a split-appendix technique had median operative time of 447 min compared to 619 min when a Monti channel was created. The median length of hospital stay was 9 days for the split-appendix technique compared to 12 and 13 day median hospital stay when the appendix was used only for the urinary channel or a Monti was created, respectively. There was no difference seen in revision free survival of the channel following surgery of any of the channels with median follow-up of 44.5 months. However, there were more subfascial revisions of urinary CCC in those that underwent a Monti (5 patients, 18.5%) compared to other bowel segments (0 patients).

CONCLUSIONS

Utilizing a split-appendix approach for creation of urinary and fecal CCCs does not affect 30-day complications or long-term revision rates compared to other established techniques. This technique minimizes the potential surgical morbidity of a bowel anastomosis and provide shorter operative times, when feasible, at time of simultaneous creation of fecal and urinary CCC.

Healed Varicella Pneumonia: A Case of Diffuse Pulmonary Microcalcifications

Varicella pneumonia is a potentially fatal complication of the Varicella-zoster virus (VZV), which causes the well-known chickenpox disease of childhood. Identifying this type of pneumonia by characteristic features is important for radiologists and radiology residents. Typical manifestations of active Varicella pneumonia include diffuse pulmonary nodules, which may mimic other diseases. Healed Varicella pneumonia can present as diffuse, calcified pulmonary micronodules. We describe a case of healed Varicella pneumonia in a patient with a history of remote VZV infection.

A Prolonged Neurological Presentation of Legionnaire's Disease

Legionnaire's disease is an uncommon pneumonic disease that can carry a mortality rate up to 20%. It commonly presents as an atypical lower respiratory illness. However, it is important to be mindful of the various extra-pulmonic presentations of the infection. Here, we present a case of a 51-year-old female who presented to the emergency department with lethargy, slurred speech, and confusion. Legionella has been reported to present with neurological symptoms but it is not a common occurrence in each hospitalization. These neurological symptoms often lead to an extensive workup and the complexity of the diagnostic workup can significantly influence patient outcome. However, it is crucial that physicians follow a systemic approach to establish a diagnosis in an expedited manner. This case emphasizes the importance of key objective evidence of legionella that can help guide a physician's diagnostic approach.

Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

Thermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m² at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

Near-field thermophotovoltaic holds the potential for achieving high-power density and energy conversion efficiency by utilizing evanescent modes of heat transfer, yet the performance still lags behind the far-field counterpart. Here, the authors combine thermally robust planar emitter with InGaAs PV to push the limit of near-field device further.

A review on application of next-generation sequencing methods for profiling of protozoan parasites in water: Current methodologies, challenges, and perspectives

The advancement in metagenomic techniques has provided novel tools for profiling human parasites in environmental matrices, such as water and wastewater. However, application of metagenomic techniques for the profiling of protozoan parasites in environmental matrices is not commonly reported in the literature. The key factors leading to the less common use of metagenomics are the complexity and large eukaryotic genome, the prevalence of small parasite populations in environmental samples compared to bacteria, difficulties in extracting DNA from (oo)cysts, and limited reference databases for parasites. This calls for further research to develop optimized methods specifically looking at protozoan parasites in the environment. This study reviews the current workflow, methods and provide recommendations for the standardization of techniques. The article identifies and summarizes the key methods, advantages, and limitations associated with metagenomic analysis, like sample pre-processing, DNA extraction, sequencing approaches, and analysis methods. The study enhances the understanding and application of standardized protocols for profiling of protozoan parasite community from highly complexe samples and further creates a resourceful comparison among datasets without any biases.

Diagnosis and Management of Adrenal Insufficiency in Hospitalized Patients

BACKGROUND

Plasma cortisol is commonly obtained in hospitalized hypotensive patients, and adrenocorticotropic hormone (ACTH) challenge is typically conducted to further workup hypocortisolemia. It is important to recognize that relative adrenal insufficiency (AI) is the most common cause of low cortisol levels and failed ACTH challenge in ill patients. Both cortisol and synthetic ACTH challenge assays are unreliable in critically ill patients. In clinical practice, corticosteroid therapy in septic shock patients results in immediate hemodynamic benefits with less vasopressor and ventilator dependence.

AREAS OF UNCERTAINTY

There is no consensus about the diagnostic criteria of relative AI, appropriate cortisol level, and the dose used for synthetic ACTH challenge in patients with septic shock. There is controversy about the mortality benefits of supplemental steroid therapy and about the use of adjunctive fludrocortisone.

DATA SOURCES

PubMed search of randomized control trials and meta-analyses.

THERAPEUTIC OPINION

Despite all the controversies, hospital physicians frequently use steroids in patients with septic shock with hypocortisolemia. Hydrocortisone should be the choice of steroid for most relative AI patients, and fludrocortisone can be added on a case-by-case basis in refractory shock. Most of the adverse effects induced by a short course of steroids are easily managed in the inpatient setting.

Microwatt-Resolution Calorimeter for Studying the Reaction Thermodynamics of Nanomaterials at High Temperature and Pressure

Calorimetry of reactions involving nanomaterials is of great current interest, but requires high-resolution heat flow measurements and long-term thermal stability. Such studies are especially challenging at elevated reaction pressures and temperatures. Here, we present an instrument for measuring the enthalpy of reactions between gas-phase reactants and milligram scale nanomaterial samples. This instrument can resolve the net change in the amount of gas-phase reactants due to surface reactions in an operating range from room temperature to 300 °C and reaction pressures of 10 mbar to 30 bar. The calorimetric resolution is shown to be <3 μW/√Hz, with a long-term stability <4 μW/hour. The performance of the instrument is demonstrated via a set of experiments involving H₂ absorption on Pd nanoparticles at various pressures and temperatures. For this specific reaction, we obtained a mass balance resolution of 0.1 μmol/√Hz. Results from these experiments are in good agreement with past studies establishing the feasibility of performing high resolution calorimetry on milligram scale nanomaterials, which can be employed in future studies probing catalysis, phase transformations, and thermochemical energy storage.