Description of a national,multi-center registry of patients with sickle cell disease and SARS-CoV-2 infection: Data from the Pediatric COVID-19 United States Registry

Children with sickle cell disease (SCD) are at risk of complications from viral infections, including SARS-CoV-2. We present the clinical characteristics and outcomes of pediatric patients with SCD from the Pediatric COVID-19 United States Registry who developed acute COVID-19 due to SARS-CoV-2 infection (n = 259) or multisystem inflammatory syndrome in children (MIS-C; n = 4). Nearly half of hospitalized children with SCD and SARS-CoV-2 infection required supplemental oxygen, though children with SCD had fewer intensive care (ICU) admissions compared to the general pediatric and immunocompromised populations. All registry patients with both SCD and MIS-C required ICU admission. Children with SCD are at risk of severe disease with SARS-CoV-2 infection, highlighting the importance of vaccination in this vulnerable population.     

A New Suture for Hair Transplantation: Poliglecaprone 25

BACKGROUND: The most common type of donor closure in hair transplantation is with nonabsorbable, running sutures, usually of nylon or polypropylene. This is accomplished with or without buried absorbable sutures. Another popular method of closure is with stainless steel staples. Each of these methods has benefits and limitations with respect to healing, comfort, and convenience for the patient. OBJECTIVE: The purpose of this study is to describe the use of poliglecaprone 25, a synthetic, absorbable, monofilament suture in hair transplantation surgery, to detail the suturing techniques needed to maximize the benefit of this suture, and to compare this material and suturing technique to a well-established form of closure, that of metal staples in a bilaterally controlled fashion. METHODS: Poliglecaprone 25 is a synthetic, absorbable monofilament suture of low tissue reactivity. It was compared to closure with metal staples in a bilateral controlled study. One side of the donor area was closed with poliglecaprone 25 sutures using a running cutaneous stitch and the other side was closed with stainless steel staples. Patients were evaluated with regard to healing, postoperative discomfort, resultant surgical scar, and closure material preference. RESULTS: Of the 22 patients studied, the following postoperative complaints were noted on the staples side: tenderness (12), itching (4), swelling (2), and scabbing (1). This compared to only one complaint of itching and one complaint of swelling on the poliglecaprone 25 side. Two patients had postoperative complaints of visibility of staples showing through their hair. Objective measurements revealed a wider scar overall on the staples side in six patients and wider scar on the suture side in two patients. The average scar width on the staples side measured 1.78 mm compared to 1.42 mm on the suture side. Fourteen of the 22 patients preferred poliglecaprone 25 for future procedures, 1 preferred metal staples, and 7 had no preference. Most patients stated that postoperative discomfort from the staples and the inconvenience and occasional pain associated with their removal was responsible for their decision. CONCLUSION: Poliglecaprone 25 is a strong synthetic, absorbable, monofilament suture with low tissue reactivity that can be used in hair transplantation to close the donor wound with a single, running cutaneous stitch. This suture can provide a donor closure that ensures hemostasis, has little risk of infection, and is comfortable for the patient. If specific surgical techniques are followed, this suture can provide a donor closure that ensures hemostasis has little risk of complications, is both comfortable and convenient for the patient postoperatively and results in a fine surgical scar.     

Valveless microliter combustion for densely packed arrays of powerful soft actuators

Existing tactile stimulation technologies powered by small actuators offer low-resolution stimuli compared to the enormous mechanoreceptor density of human skin. Arrays of soft pneumatic actuators initially show promise as small-resolution (1- to 3-mm diameter), highly conformable tactile display strategies yet ultimately fail because of their need for valves bulkier than the actuators themselves. In this paper, we demonstrate an array of individually addressable, soft fluidic actuators that operate without electromechanical valves. We achieve this by using microscale combustion and localized thermal flame quenching. Precisely, liquid metal electrodes produce sparks to ignite fuel lean methane–oxygen mixtures in a 5-mm diameter, 2-mm tall silicone cylinder. The exothermic reaction quickly pressurizes the cylinder, displacing a silicone membrane up to 6 mm in under 1 ms. This device has an estimated free-inflation instantaneous stroke power of 3 W. The maximum reported operational frequency of these cylinders is 1.2 kHz with average displacements of ∼100 µm. We demonstrate that, at these small scales, the wall-quenching flame behavior also allows operation of a 3 × 3 array of 3-mm diameter cylinders with 4-mm pitch. Though we primarily present our device as a tactile display technology, it is a platform microactuator technology with application beyond this one.

Through the senses, human beings constantly gain rich information about the external world; ultimately, everything one knows comes from what one first learns through one’s sense powers (1). Though sight is generally considered to be our strongest sensorial asset, touch (pressure, pain, vibration, temperature, etc.) intimately connects us with our nearby environment and our own bodies. Touch is, perhaps, more necessary for survival than any other sense (2–8). It is unsurprising, then, that our skin is our bodies’ largest organ (9, 10), comprising in part a diverse array of mechanoreceptive organelles, allowing people to feel skin deformations of different types, durations, and intensities (11). For example, human fingertips have over 200 mechanoreceptive units per square centimeter (10), perceiving static deformations of down to 0.1 mm (12) and vibrations of up to 400 Hz (10, 13).Despite the importance of touch, our visual and auditory senses dominate the experience of digital information. The most proliferate form of haptic actuation is vibrotactile, but this technique does not allow the type of displacement and persistence of touch required to provide a natural experience. Vibrations alone cannot meaningfully recreate the pressure felt from a bag on the shoulders or the impact of a ball caught in the hands. Because of this lack of haptic experience, at least two societal needs remain unfulfilled: artificial touch recreation in immersive virtual reality (VR) and braille displays that compete with analogous visual media. For braille, specifically, there are no full-page, affordable, portable, refreshable displays on the market (14).The dearth of available tactile display options is not from lack of trying; manufacturing arrays of actuators at the size and density suitable for reading computer information from a tactile screen requires reducing actuator volume, weight, power draw, and cost, all together. The diverse set of designs conceived to achieve this haptic challenge have employed an equally numerous suite of physical principles, and each actuation method has presented its own failure mode (14). For example, thermal actuators usually take seconds (without thermal management accessories) (15) to finish a work loop because of heat transport limitations (16). Pulsed electromagnetic systems suffer from low actuation forces and interference between individual actuators (crosstalk) when made close to the size of a braille dot (17). Piezoelectric devices have large production costs at scale (HyperBraille systems cost ∼$50,000), also needing long cantilevered geometries that impede their ability to be densely arranged (14, 18).Fluidic elastomer actuators (FEAs) displace rubber forms with liquids and gases, showing promise as dense actuator arrays because of their manufacturing simplicity and favorable mechanical characteristics (19). An elastomeric membrane ∼1 mm in diameter can displace more than 0.5 mm as was previously shown by ref. 20 in which a 1.5-mm diameter viscoelastic membrane displaced 0.56 mm in about 1 s. Beyond simplicity, these soft haptic devices also have the convenient ability to conform to complex body shapes (21). For example, HaptX has developed a commercial, tethered VR glove technology that integrates 130 individually addressable fluidic actuators into each glove (22). This paper’s lead author has experienced this technology and testifies to its natural feel (23). As designed, the glove’s microfluidic channels are tethered to a large box housing a pump and many valves, limiting the user’s range of motion. One major deficiency of FEAs is how the system scales with actuator number density: there is generally a linear relationship between the number of valves and actuators. As electromechanical valves are themselves actuators, the size, weight, power, and cost (SWaP-C) requirements of FEA arrays soon become untenable for portable tactile display systems. For example, the most popular valve choice for FEAs is the Parker X-Valve, with dimensions of 7.87 × 23.37 × 12.30 mm³ at a unit cost of ∼$40 (24); if a single, six-dot braille cell (∼6 × 10 × 10 mm³) was controlled by six valves, that is, one valve per actuator, the array of valves would take up 18.4 times the cell area and cost $240 (14). Though there are multiplexing solutions to the valving challenge (25), we are currently unaware of any high-resolution tactile interaction being enabled by these methods.Counterintuitively, microscale combustion could provide an alternative actuation motif for haptic arrays, given its own engineering tradeoffs. Combining high-energy density fuels (26, 27) with small-volume mechanical elements results in a potentially safe and enduring actuation mechanism. Previously, microscale combustion research primarily focused on replacing batteries with high–power density micro-electromechanical systems (MEMS) thermoelectric generators (28). These systems may have failed to become practical because of unwanted flame extinction, thermal degradation, and frictional wear (29). More recently, combustion has been used in FEAs for macroscale soft robots and pumps (30–34). A spark ignites a combustible gas mixture that rapidly heats the product gas and expands the soft FEA cavity to move a robot or separate fluid. This research direction, however, has not been previously expanded into the realm of small gas-powered FEAs (35).In this paper, we make two contributions: 1) the use of combustion in microliter-scale FEAs for powerful, high-stroke, millimeter-scale actuations and 2) the exploitation of rapid thermal quenching at these scales to individually actuate fluidically coupled arrays without valving. As we no longer need valves, we can space the actuators more closely because their flow and electrical control components occupy less area than the actuator footprint. Primarily composed of molded silicone and microfluidic liquid metal (LM) traces, our design is an inexpensive, thin rubber sheet that provides more favorable SWaP-C scaling than prior FEA systems. We elementally characterize our device’s mechanical performance as a general microactuation strategy. As tactile display systems represent one of the oldest, broadest, and most contemporary microactuator research initiatives, we focus our discussion and demonstration on this system’s potential to serve a similar purpose.     

Cryosurgery after chemoembolization for hepatocellular carcinoma in patients with cirrhosis

Most cirrhotic patients with hepatocellular carcinoma (HCC) are not candidates for resection. Transarterial chemoembolization (TACE) may ablate a significant portion of the tumor but has a high rate of recurrence. Cryosurgery may permit successful ablation of hepatic tumors but can be complicated by post-operative hemorrhage and is also associated with a significant risk of recurrence. The combination of the two techniques might be beneficial. We evaluated in a prospective study the safety and efficacy of this combination in cirrhotic patients with unresectable HCC. Fifteen patients were included in this study. All but one patient underwent one or several sessions of TACE before cryosurgery. Cryoablation was successfully performed in each patient. The patient who did not undergo preoperative TACE required reoperation for hemorrhage. Another patient with Child-Pugh class B cirrhosis died postoperatively of hepatic and multiorgan failure. At a mean follow-up of 2.5 years, three patients had recurrence of disease, and 13 of 15 patients were alive with the longest survival time being 5 years. The actuarial survival rate at 5 years was 79%. Cryosurgery after TACE is feasible in cirrhotic livers with HCC and can increase the cure rate in large tumors. TACE may reduce the risk of hemorrhage after cryosurgery but can increase the risk of hepatic failure in patients with poor hepatic function. Presented at the Third Americas Congress of the American Hepato-Pancreato-Biliary Association, Miami, Fla., Feb. 22–25, 2001.     

Gene-gene,gene-environment,gene-nutrient interactions and single nucleotide polymorphisms of inflammatory cytokines

Inflammation plays a significant role in the etiology of type 2 diabetes mellitus(T2DM).The rise in the pro-inflammatory cytokines is the essential step in glucotoxicity and lipotoxicity induced mitochondrial injury,oxidative stress and beta cell apoptosis in T2 DM.Among the recognized markers are interleukin(IL)-6,IL-1,IL-10,IL-18,tissue necrosis factor-alpha(TNF-α),C-reactive protein,resistin,adiponectin,tissue plasminogen activator,fibrinogen and heptoglobins.Diabetes mellitus has firm genetic and very strong environmental influence; exhibiting a polygenic mode of inheritance.Many single nucleotide polymorphisms(SNPs) in various genes including those of pro and antiinflammatory cytokines have been reported as a risk for T2 DM.Not all the SNPs have been confirmed by unifying results in different studies and wide variations have been reported in various ethnic groups.The inter-ethnic variations can be explained by the fact that gene expression may be regulated by gene-gene,gene-environment and gene-nutrient interactions.This review highlights the impact of these interactions on determining the role of single nucleotide polymorphism of IL-6,TNF-α,resistin and adiponectin in pathogenesis of T2 DM.     

Clinical epidemiology of ulcerative colitis in Arabs based on the Montréal classification

AIM: To determine the clinical, epidemiological and phenotypic characteristics of ulcerative colitis (UC) in Saudi Arabia by studying the largest cohort of Arab UC patients.METHODS: Data from UC patients attending gastroenterology clinics in four tertiary care centers in three cities between September 2009 and September 2013 were entered into a validated web-based registry, inflammatory bowel disease information system (IBDIS). The IBDIS database covers numerous aspects of inflammatory bowel disease. Patient characteristics, disease phenotype and behavior, age at diagnosis, course of the disease, and extraintestinal manifestations were recorded.RESULTS: Among 394 UC patients, males comprised 51.0% and females 49.0%. According to the Montréal classification of age, the major chunk of our patients belonged to the A2 category for age of diagnosis at 17-40 years (68.4%), while 24.2% belonged to the A3 category for age of diagnosis at > 40 years. According to the same classification, a majority of patients had extensive UC (42.7%), 35.3% had left-sided colitis and 29.2% had only proctitis. Moreover, 51.3% were in remission, 16.6% had mild UC, 23.4% had moderate UC and 8.6% had severe UC. Frequent relapse occurred in 17.4% patients, infrequent relapse in 77% and 4.8% had chronic disease. A majority (85.2%) of patients was steroid responsive. With regard to extraintestinal manifestations, arthritis was present in 16.4%, osteopenia in 31.4%, osteoporosis in 17.1% and cutaneous involvement in 7.0%.CONCLUSION: The majority of UC cases were young people (17-40 years), with a male preponderance. While the disease course was found to be similar to that reported in Western countries, more similarities were found with Asian countries with regards to the extent of the disease and response to steroid therapy.     

Oxidative and carbonyl stress in pregnant women with obstructive sleep apnea

Sleep and Breathing - Pregnant women are particularly susceptible to sleep-disordered breathing. Obstructive sleep apnea (OSA) in pregnancy is associated with poor pregnancy and fetal outcomes....     

Effects of Obesity and Hypertension on Pulse Wave Velocity in Children

Pulse wave velocity (PWV) is a biomarker of arterial stiffness. Findings from prior studies are conflicting regarding the impact of obesity on PWV in children. The authors measured carotid‐femoral PWV in 159 children aged 4 to 18 years, of whom 95 were healthy, 25 were obese, 15 had hypertension (HTN), and 24 were both obese and hypertensive. Mean PWV increased with age but did not differ by race or sex. In adjusted analyses in children 10 years and older (n=102), PWV was significantly higher in children with hypertension (PWV±standard deviation, 4.9±0.7 m/s), obesity (5.0±0.9 m/s), and combined obesity‐hypertension (5.2±0.6 m/s) vs healthy children (4.3±0.7 m/s) (each group, P<.001 vs control). In our study, obesity and HTN both significantly and independently increased PWV, while African American children did not have a higher PWV than Caucasian children.