Irreversible Electroporation as an Effective Technique for Ablating Human Metastatic Osteosarcoma.

Irreversible electroporation (IRE) induces apoptosis in tumor cells with electric energy, allowing treatment of unresectable tumors. One potential application is metastatic osteosarcoma (OS) in the pediatric population. A 12-year-old underwent thoracotomy with resection of metastatic OS. IRE was applied to 1 resected tumor section. Using 2 probes, 100 pulses with width of 90 ms were delivered. Efficacy was measured by increase in current draw during treatment. The treated sample was analyzed with hematoxylin and eosin and transmission electron microscopy. Default voltage of 1800 kV was ineffective. Voltage of 2700 kV caused excessive current draw and was aborted to prevent thermal injury. At 2200 kV, current draw rise was 9 amps, signifying successful treatment. Untreated specimen showed viable OS, normal surrounding lung tissue. Treated tumor had edema within the tumor and in surrounding lung tissue, with intra-alveolar hemorrhage and cellular architecture destruction. There was also evidence for cellular destruction such as disruption of lipid bilayer and release of intracellular fluid. Optimal voltage for treatment was 2200 kV, likely higher due to electrical conduction variation in the aerated lung. IRE may be an option for pediatric patients with unresectable metastatic OS.

An adolescent with Wolfram syndrome and central sleep apnea.

Wolfram syndrome is a rare autosomal recessive disorder affecting approximately 1 in 500,000 individuals. The disorder is most commonly caused by mutations in the WFS1 gene, which encodes an endoplasmic reticulum protein, wolframin, which is thought to protect against endoplasmic reticulum stress-related apoptosis. The major clinical findings of Wolfram syndrome are diabetes mellitus and optic atrophy, both of which usually appear before 16 years of age. Common additional findings include sensorineural hearing impairment, central diabetes insipidus, nonautoimmune hypothyroidism, delayed puberty, neurogenic bladder, cerebellar ataxia, and psychiatric disorders. Central sleep apnea is an uncommon but serious feature of Wolfram syndrome. However, the clinical details of this manifestation have not been documented. Herein, we report an adolescent with recently diagnosed Wolfram syndrome who demonstrated severe central sleep apnea on polysomnography testing. CITATION: Harris JC, Kenkare JD, Schramm CM. An adolescent with Wolfram syndrome and central sleep apnea. J Clin Sleep Med. 2024;20(7):1205-1208.

Can Anorectal Stenosis be Managed With Dilations Alone? A PCPLC Review.

PURPOSE: Congenital anorectal stenosis is managed by dilations or operative repair. Recent studies now propose use of dilations as the primary treatment modality to potentially defer or eliminate the need for surgical repair. We aim to characterize the management and outcomes of these patients via a multi-institutional review using the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC) registry. METHODS: A retrospective database review was performed using the PCPLC registry. The patients were evaluated for demographics, co-morbidities, diagnostic work-up, surgical intervention, current bowel management, and complications. RESULTS: 64 patients with anal or rectal stenosis were identified (57 anal, 7 rectal) from a total of 14 hospital centers. 59.6% (anal) and 42.9% (rectal) were male. The median age was 3.2 (anal) and 1.9 years (rectal). 11 patients with anal stenosis also had Currarino Syndrome with 10 of the 11 patients diagnosed with a presacral mass compared to only one rectal stenosis with Currarino Syndrome and a presacral mass. 13 patients (22.8%, anal) and one (14.3%, rectal) underwent surgical correction. Nine patients (8 anal, 1 rectal) underwent PSARP. Other procedures performed were cutback anoplasty and anterior anorectoplasty. The median age at repair was 8.4 months (anal) and 10 days old (rectal). One patient had a wound complication in the anal stenosis group. Bowel management at last visit showed little differences between groups or treatment approach. CONCLUSION: The PCPLC registry demonstrated that these patients can often be managed successfully with dilations alone. PSARP is the most common surgical repair chosen for those who undergo surgical repair. LEVEL OF EVIDENCE: III.

Lack of cAMP-response element-binding protein 1 in the hypothalamus causes obesity.

The melanocortin system in the hypothalamus controls food intake and energy expenditure. Its disruption causes severe obesity in mice and humans. cAMP-response element-binding protein 1 (CREB1) has been postulated to play an important role downstream of the melanocortin-4 receptor (MC4R), but this hypothesis has never been confirmed in vivo. To test this, we generated mice that lack CREB1 in SIM1-expressing neurons, of the paraventricular nucleus (PVN), which are known to be MC4R-positive. Interestingly, CREB1(ΔSIM1) mice developed obesity as a result of decreased energy expenditure and impairment in maintaining their core body temperature and not because of hyperphagia, defining a new role for CREB1 in the PVN. In addition, the lack of CREB1 in the PVN caused a reduction in vasopressin expression but did not affect adrenal or thyroid function. Surprisingly, MC4R function tested pharmacologically was normal in CREB1(ΔSIM1) mice, suggesting that CREB1 is not required for intact MC4R signaling. Thus CREB1 may affect other pathways that are implicated in the regulation of body weight.

Bacterial Surface Detachment during Nebulization with Contaminated Reusable Home Nebulizers.

Patients with chronic respiratory diseases use home nebulizers that are often contaminated with pathogenic microbes to deliver aerosolized medications. The conditions under which these microbes leave the surface as bioaerosols during nebulization are not well characterized. The objectives of this study were to (i) determine whether different pathogens detach and disperse from the nebulizer surface during aerosolization and (ii) measure the effects of relative humidity and drying times on bacterial surface detachment and aerosolization. Bacteria were cultured from bioaerosols after Pari LC Plus albuterol nebulization using two different sources, as follows: (i) previously used nebulizers donated by anonymous patients with cystic fibrosis (CF) and (ii) nebulizers inoculated with bacteria isolated from the lungs of CF patients. Fractionated bioaerosols were collected with a Next-Generation Impactor. For a subset of bacteria, surface adherence during rewetting was measured with fluorescence microscopy. Bacteria dispersed from the surface of used CF patient nebulizers during albuterol nebulization. Eighty percent (16/20) of clinical isolates inoculated on the nebulizer in the laboratory formed bioaerosols. Detachment from the plastic surface into the chamber solution predicted bioaerosol production. Increased relative humidity and decreased drying times after inoculation favored bacterial dispersion on aerosols during nebulized therapy. Pathogenic bacteria contaminating nebulizer surfaces detached from the surface as bioaerosols during nebulized therapies, especially under environmental conditions when contaminated nebulizers were dried or stored at high relative humidity. This finding emphasizes the need for appropriate nebulizer cleaning, disinfection, and complete drying during storage and informs environmental conditions that favor bacterial surface detachment during nebulization. IMPORTANCE Studies from around the world have demonstrated that many patients use contaminated nebulizers to deliver medication into their lungs. While it is known that using contaminated medications in a nebulizer can lead to a lung infection, whether bacteria on the surface of a contaminated nebulizer detach as bioaerosols capable of reaching the lung has not been studied. This work demonstrates that a subset of clinical bacteria enter solution from the surface during nebulization and are aerosolized. Environmental conditions of high relative humidity during storage favor dispersion from the surface. We also provide results of an in vitro assay conducted to monitor bacterial surface detachment during multiple cycles of rewetting that correlate with the results of nebulizer/bacterial surface interactions. These studies demonstrate for the first time that pathogenic bacteria on the nebulizer surface pose a risk of bacterial inhalation to patients who use contaminated nebulizers.

Management of broncho-esophageal fistula after button battery ingestion.

Button battery ingestion can cause serious injury or death in young children who cannot communicate symptoms. An 18-month-old male presented after his mother noted drooling, nonbilious emesis and a metallic smell to his breath. He underwent rigid esophagoscopy and a 3-V 20-mm button battery was removed. Subsequent bronchoscopy after a 1-week interval revealed progression to a large broncho-esophageal fistula on the posterior wall of the right mainstem bronchus past the carina. A fenestrated nasogastric tube for local control of secretion and a feeding jejunostomy was placed. Six weeks later, the patient underwent a right thoracotomy for division and repair of the fistula and intercostal muscle flap interposition. Utilizing a well-placed fenestrated nasogastric tube to manage secretions can help reduce fistula size and improve conservative management results. When surgical repair is required, an intercostal muscle flap can reinforce fistula closure while simultaneously buttressing the bronchus and esophagus.

Overweight and Obese Pediatric Patients Have an Increased Risk of Developing a Surgical Site Infection.

BACKGROUND: Obesity is a known risk factor in adult surgical site infections (SSIs), but its significance in pediatrics is unclear. We hypothesized that overweight and obese children have increased risk for SSI. PATIENTS AND METHODS: A National Surgical Quality Improvement Program-Pediatric (NSQIP-P) file and single-center reviews identified surgical patients (2-18 years) who developed SSIs. Patients were classified as underweight, normal, overweight, or obese based on body mass index (BMI). Comorbidities associated with SSI were analyzed. Sub-specialties and operations were recorded. RESULTS: National Surgical Quality Improvement Program-Pediatric review identified 66,671 patients and 1,380 SSIs. Seven hundred sixty-seven (767) were male and 613 female. Multivariable analysis revealed overweight and obese BMI to be risk factors for SSIs (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.06-1.43; OR 1.43, 95% CI 1.25-1.63). Most commonly, overweight and obese cohorts had superficial incisional SSIs. Pediatric general surgery (3.6%) and cardiothoracic surgery (2.5%) had the highest rates of SSIs. Single-center review identified 115 SSIs. Of these, 29.6% were overweight or obese with few other identifiable SSI risk factors. Sub-specialties with the most SSIs were pediatric surgery and pediatric orthopedics. Appendectomy was the most common procedure associated with SSIs. CONCLUSION: Herein we show elevated BMI to be a significant risk factor for SSIs. This information should be used in assessing and counseling pre-operative pediatric patients and families.

Cutaneous angiosarcoma metastatic to small bowel with nodal involvement.

A 77-year-old male with a history of metastatic scalp angiosarcoma presented with intractable gastrointestinal bleeding from a jejunal mass detected on capsule endoscopy. He underwent laparoscopic-assisted resection of the mass. Intraoperatively, an isolated small bowel mass with bulky lymphadenopathy was seen and resected en bloc. Pathology showed a 6.8cm high-grade metastatic angiosarcoma with nodal involvement and negative margins. Angiosarcoma is a sarcoma with a grim prognosis. The incidence is 2% of all soft tissue sarcomas; cutaneous lesions comprise 27% of manifestations and usually appear on head and neck. Risk factors include lymphedema, neurofibromatosis, vinyl chloride, arsenic, and anabolic steroids. Overall 5-year survival is 30-35% and is higher in patients younger than 60, those without metastasis, tumors less than 5 cm, and favorable histology. Angiosarcoma metastasis to small bowel is rare but nodal involvement is even more unusual, reported only three times in the literature. This case is the first with nodal involvement to present at a resectable stage. To diagnose disease when still at a resectable stage, a high index of suspicion must be maintained with any gastrointestinal symptoms in a patient with a history of angiosarcoma. Laparoscopic-assisted resection is safe for the resection of small bowel angiosarcoma.

Sustained delivery of vincristine inside an orthotopic mouse sarcoma model decreases tumor growth.

BACKGROUND: Sarcoma accounts for 20% of solid tumors in children. Surgery has significant morbidity. We hypothesized that delivering chemotherapy directly into tumors through sustained release silk systems could slow tumor growth. METHODS: Human Ewing sarcoma cells A673 were cultured with vincristine and doxorubicin to determine half maximal inhibitory concentration (IC50). Cells were injected into mouse hind leg to create orthotopic tumors. Tumor volumes were measured using ultrasound. When volume reached >250mm3, interventions included: implantation of drug-free silk foam (Control-F), doxorubicin 400µg foam (Dox400-F), vincristine 50µg foam (Vin50-F), drug-free silk gel (Control-G), vincristine 50µg gel (Vin50-G), or single dose intravenous vincristine 50µg (Vin50-IV). End-point was volume>1000mm3. Kaplan Meier and ANOVA were used. RESULTS: IC50 for vincristine and doxorubicin was 0.5ng/mL and 200ng/mL, respectively. There was no difference between Dox400-F [6±1days to end point (DTEP)] and Control-F (5±1.3 DTEP). Vin50-F (12.4±3.5 DTEP) had slower growth compared to Control-F (p<0.001), and there was no difference between Vin50-F and Vin50-IV (14±0 DTEP). Growth was slowest with Vin50-G, 28±10.3 DTEP compared to all other treatment groups (p<0.05). CONCLUSION: Sustained delivery of vincristine inside the sarcoma tumor with silk gel decreased tumor growth. Applying this intratumoral treatment strategy may potentially decrease the extent of surgical excision.

Thyroid hormone signaling in vivo requires a balance between coactivators and corepressors.

Resistance to thyroid hormone (RTH), a human syndrome, is characterized by high thyroid hormone (TH) and thyroid-stimulating hormone (TSH) levels. Mice with mutations in the thyroid hormone receptor beta (TRß) gene that cannot bind steroid receptor coactivator 1 (SRC-1) and Src-1(-/-) mice both have phenotypes similar to that of RTH. Conversely, mice expressing a mutant nuclear corepressor 1 (Ncor1) allele that cannot interact with TRß, termed NCoRΔID, have low TH levels and normal TSH. We hypothesized that Src-1(-/-) mice have RTH due to unopposed corepressor action. To test this, we crossed NCoRΔID and Src-1(-/-) mice to create mice deficient for coregulator action in all cell types. Remarkably, NCoR(ΔID/ΔID) Src-1(-/-) mice have normal TH and TSH levels and are triiodothryonine (T(3)) sensitive at the level of the pituitary. Although absence of SRC-1 prevented T(3) activation of key hepatic gene targets, NCoR(ΔID/ΔID) Src-1(-/-) mice reacquired hepatic T(3) sensitivity. Using in vivo chromatin immunoprecipitation assays (ChIP) for the related coactivator SRC-2, we found enhanced SRC-2 recruitment to TR-binding regions of genes in NCoR(ΔID/ΔID) Src-1(-/-) mice, suggesting that SRC-2 is responsible for T(3) sensitivity in the absence of NCoR1 and SRC-1. Thus, T(3) targets require a critical balance between NCoR1 and SRC-1. Furthermore, replacement of NCoR1 with NCoRΔID corrects RTH in Src-1(-/-) mice through increased SRC-2 recruitment to T(3) target genes.

NPY and MC4R signaling regulate thyroid hormone levels during fasting through both central and peripheral pathways.

Fasting-induced suppression of the hypothalamic-pituitary-thyroid (HPT) axis is an adaptive response to decrease energy expenditure during food deprivation. Previous studies demonstrate that leptin communicates nutritional status to the HPT axis through thyrotropin-releasing hormone (TRH) in the paraventricular nucleus (PVN) of the hypothalamus. Leptin targets TRH neurons either directly or indirectly via the arcuate nucleus through pro-opiomelanocortin (POMC) and agouti-related peptide/neuropeptide Y (AgRP/NPY) neurons. To evaluate the role of these pathways in vivo, we developed double knockout mice that lack both the melanocortin 4 receptor (MC4R) and NPY. We show that NPY is required for fasting-induced suppression of Trh expression in the PVN. However, both MC4R and NPY are required for activation of hepatic pathways that metabolize T(4) during the fasting response. Thus, these signaling pathways play a key role in the communication of fasting signals to reduce thyroid hormone levels both centrally and through a peripheral hepatic circuit.