Carle Foundation Hospital

rRNA-based studies, which have become the most common method for assessing microbial communities, rely upon faithful amplification of the corresponding genes from the original DNA sample. We report here an analysis and reevaluation of commonly used primers for amplifying the DNA between positions 27 and 1492 of bacterial 16S rRNA genes (numbered according to the Escherichia coli rRNA). We propose a formulation for a forward primer (27f) that includes three sequences not usually present. We compare our proposed formulation to two common alternatives by using linear amplification-providing an assessment that is independent of a reverse primer-and in combination with the 1492 reverse primer (1492r) under the PCR conditions appropriate for making community rRNA gene clone libraries. For analyses of DNA from human vaginal samples, our formulation was better at maintaining the original rRNA gene ratio of Lactobacillus spp. to Gardnerella spp., particularly under stringent amplification conditions. Because our 27f formulation remains relatively simple, having seven distinct primer sequences, there is minimal loss of overall amplification efficiency and specificity.

A large International Restless Legs Syndrome (RLS) Study Group has been formed. As its first task, the group has taken upon itself the role of defining the clinical features of the RLS. As minimal criteria for diagnosis, the group proposes the following four features: (a) desire to move the extremities, often associated with paresthesias/dysesthesias; (b) motor restlessness; (c) worsening of symptoms at rest with at least temporary relief by activity, and (d) worsening of symptoms in the evening or night. Other features commonly seen in RLS include sleep disturbance, periodic limb movements in sleep and similar involuntary movements while awake, a normal neurological examination in the idiopathic form, a tendency for the symptoms to be worse in middle to older age, and, in some cases, a family history suggestive of an autosomal dominant mode of inheritance.

BACKGROUND: In this trial of the treatment of newly diagnosed multiple myeloma, we compared a protocol that entailed a hematopoietic stem-cell autograft followed by an allograft from an HLA-identical sibling with a protocol of tandem autografts. METHODS: We enrolled 162 consecutive patients with newly diagnosed myeloma who were 65 years of age or younger and who had at least one sibling. All patients were initially treated with vincristine, doxorubicin, and dexamethasone, followed by melphalan and autologous stem-cell rescue. Patients with an HLA-identical sibling then received nonmyeloablative total-body irradiation and stem cells from the sibling. Patients without an HLA-identical sibling received two consecutive myeloablative doses of melphalan, each of which was followed by autologous stem-cell rescue. The primary end points were overall survival and event-free survival. RESULTS: After a median follow-up of 45 months (range, 21 to 90), the median overall survival and event-free survival were longer in the 80 patients with HLA-identical siblings than in the 82 patients without HLA-identical siblings (80 months vs. 54 months, P=0.01; and 35 months vs. 29 months, P=0.02, respectively). Among patients who completed their assigned treatment protocols, treatment-related mortality did not differ significantly between the double-autologous-transplant group (46 patients) and the autograft-allograft group (58 patients, P=0.09), but disease-related mortality was significantly higher in the double-autologous-transplant group (43% vs. 7%, P<0.001). The cumulative incidence rates of grades II, III, and IV graft-versus-host disease (GVHD) combined and of grade IV GVHD in the autograft-allograft group were 43% and 4%, respectively. Overall, 21 of 58 patients (36%) were in complete remission after a median follow-up of 38 months (range, 10 to 72) after allografting. Of the 46 patients who received two autografts, 25 (54%) died. CONCLUSIONS: Among patients with newly diagnosed myeloma, survival in recipients of a hematopoietic stem-cell autograft followed by a stem-cell allograft from an HLA-identical sibling is superior to that in recipients of tandem stem-cell autografts. (ClinicalTrials.gov number, NCT00415987 [ClinicalTrials.gov].).

OBJECTIVES: Restless legs syndrome, a common neurologic sleep disorder, occurs in 5% to 10% of adults in the United States and Western Europe. Although approximately 25% of adults with restless legs syndrome report onset of symptoms between the ages of 10 and 20 years, there is very little literature looking directly at the prevalence in children and adolescents. In this first population-based study to use specific pediatric diagnostic criteria, we examined the prevalence and impact of restless legs syndrome in 2 age groups: 8 to 11 and 12 to 17 years. METHODS: Initially blinded to survey topic, families were recruited from a large, volunteer research panel in the United Kingdom and United States. Administration was via the Internet, and results were stratified by age and gender. National Institutes of Health pediatric restless legs syndrome diagnostic criteria (2003) were used, and questions were specifically constructed to exclude positional discomfort, leg cramps, arthralgias, and sore muscles being counted as restless legs syndrome. RESULTS: Data were collected from 10,523 families. Criteria for definite restless legs syndrome were met by 1.9% of 8- to 11-year-olds and 2.0% of 12- to 17-year-olds. Moderately or severely distressing restless legs syndrome symptoms were reported to occur > or = 2 times per week in 0.5% and 1.0% of children, respectively. Convincing descriptions of restless legs syndrome symptoms were provided. No significant gender differences were found. At least 1 biological parent reported having restless legs syndrome symptoms in > 70% of the families, with both parents affected in 16% of the families. Sleep disturbance was significantly more common in children and adolescents with restless legs syndrome than in controls (69.4% vs 39.6%), as was a history of "growing pains" (80.6% vs 63.2%). Various consequences were attributed to restless legs syndrome, including 49.5% endorsing a "negative effect on mood." Data were also collected on comorbid conditions and restless legs diagnosis rates. CONCLUSIONS: These population-based data suggest that restless legs syndrome is prevalent and troublesome in children and adolescents, occurring more commonly than epilepsy or diabetes.

As breast cancer screening rates increase, smaller and more numerous lesions are being identified earlier, leading to more breast-conserving surgical procedures. Achieving a clean surgical margin represents a technical challenge with important clinical implications. Optical coherence tomography (OCT) is introduced as an intraoperative high-resolution imaging technique that assesses surgical breast tumor margins by providing real-time microscopic images up to 2 mm beneath the tissue surface. In a study of 37 patients split between training and study groups, OCT images covering 1 cm(2) regions were acquired from surgical margins of lumpectomy specimens, registered with ink, and correlated with corresponding histologic sections. A 17-patient training set used to establish standard imaging protocols and OCT evaluation criteria showed that areas of higher scattering tissue with a heterogeneous pattern were indicative of tumor cells and tumor tissue in contrast to lower scattering adipocytes found in normal breast tissue. The remaining 20 patients were enrolled into the feasibility study. Of these lumpectomy specimens, 11 were identified with a positive or close surgical margin and 9 were identified with a negative margin under OCT. Based on histologic findings, 9 true positives, 9 true negatives, 2 false positives, and 0 false negatives were found, yielding a sensitivity of 100% and specificity of 82%. These results show the potential of OCT as a real-time method for intraoperative margin assessment in breast-conserving surgeries.

Brain temperature, as an independent therapeutic target variable, has received increasingly intense clinical attention. To date, brain hypothermia represents the most potent neuroprotectant in laboratory studies. Although the impact of brain temperature is prevalent in a number of common human diseases including: head trauma, stroke, multiple sclerosis, epilepsy, mood disorders, headaches, and neurodegenerative disorders, it is evident and well recognized that the therapeutic application of induced hypothermia is limited to a few highly selected clinical conditions such as cardiac arrest and hypoxic ischemic neonatal encephalopathy. Efforts to understand the fundamental aspects of brain temperature regulation are therefore critical for the development of safe, effective, and pragmatic clinical treatments for patients with brain injuries. Although centrally-mediated mechanisms to maintain a stable body temperature are relatively well established, very little is clinically known about brain temperature's spatial and temporal distribution, its physiological and pathological fluctuations, and the mechanism underlying brain thermal homeostasis. The human brain, a metabolically "expensive" organ with intense heat production, is sensitive to fluctuations in temperature with regards to its functional activity and energy efficiency. In this review, we discuss several critical aspects concerning the fundamental properties of brain temperature from a clinical perspective.

BACKGROUND: Brain iron deficiency has been implicated in the pathophysiology of RLS, and current RLS treatment guidelines recommend iron treatment when peripheral iron levels are low. In order to assess the evidence on the oral and intravenous (IV) iron treatment of RLS and periodic limb movement disorder (PLMD) in adults and children, the International Restless Legs Syndrome Study Group (IRLSSG) formed a task force to review these studies and provide evidence-based and consensus guidelines for the iron treatment of RLS in adults, and RLS and PLMD in children. METHODS: A literature search was performed to identify papers appearing in MEDLINE from its inception to July 2016. The following inclusion criteria were used: human research on the treatment of RLS or periodic limb movements (PLM) with iron, sample size of at least five, and published in English. Two task force members independently evaluated each paper and classified the quality of evidence provided. RESULTS: A total of 299 papers were identified, of these 31 papers met the inclusion criteria. Four studies in adults were given a Class I rating (one for IV iron sucrose, and three for IV ferric carboxymaltose); only Class IV studies have evaluated iron treatment in children. Ferric carboxymaltose (1000 mg) is effective for treating moderate to severe RLS in those with serum ferritin <300 μg/l and could be used as first-line treatment for RLS in adults. Oral iron (65 mg elemental iron) is possibly effective for treating RLS in those with serum ferritin ≤75 μg/l. There is insufficient evidence to make conclusions on the efficacy of oral iron or IV iron in children. CONCLUSIONS: Consensus recommendations based on clinical practice are presented, including when to use oral iron or IV iron, and recommendations on repeated iron treatments. New iron treatment algorithms, based on evidence and consensus opinion have been developed.

Extrapulmonary tuberculosis (EPTB) accounts for more than 20% of tuberculosis (TB) cases. Xpert MTB/RIF (Xpert) (Cepheid, Sunnyvale, CA, USA) is a fully automated amplification system, for which excellent results in the diagnosis of pulmonary TB in highly endemic countries have been recently reported. We aimed to assess the performance of the Xpert system in diagnosing EPTB in a low incidence setting. We investigated with Xpert a large number of consecutive extrapulmonary clinical specimens (1,476, corresponding to 1,068 patients) including both paediatric (494) and adult samples. We found, in comparison with a reference standard consisting of combination of culture and clinical diagnosis of TB, an overall sensitivity and specificity of 81.3% and 99.8% for Xpert, while the sensitivity of microscopy was 48%. For biopsies, urines, pus and cerebrospinal fluids the sensitivity exceeded 85%, while it was slightly under 80% for gastric aspirates. It was, in contrast, lower than 50% for cavitary fluids. High sensitivity and specificity (86.9% and 99.7%, respectively) were also obtained for paediatric specimens. Although the role of culture remains central in the microbiological diagnosis of EPTB, the sensitivity of Xpert in rapidly diagnosing the disease makes it a much better choice compared to smear microscopy. The ability to rule out the disease still remains suboptimal.

Sleep disruption can lead to symptoms of attention-deficit hyperactivity disorder (ADHD) in children. Since periodic limb movement disorder and/or restless legs syndrome can cause sleep disruption, we assessed whether these two specific sleep disorders are likely to occur in children with ADHD. We asked a series of 69 consecutive parents of children with ADHD questions about the symptoms of periodic limb movement disorder. Based on a positive response to these periodic limb movement disorder queries, 27 children underwent all-night polysomnography. Eighteen children (aged 2 to 15 years) of the 27 (26% of the 69 children with ADHD) had 5 or more periodic leg movements in sleep per hour of sleep and had complaints of sleep disruption, thus fulfilling the criteria for periodic limb movement disorder. A comparably age- and sex-matched group of children referred to a sleep laboratory for sleep complaints but without ADHD showed only a 5% prevalence (2 of 38 subjects) of periodic leg movements in sleep (P=.017). Eight of the 18 children with ADHD and periodic limb movement disorder and one of the two control patients with periodic limb movement disorder had both a personal and parental history of restless legs syndrome symptomatology. This study further documents the occurrence of periodic limb movement disorder and restless legs syndrome in children and is the first large-scale study establishing a possible comorbidity between ADHD and periodic limb movement disorder. We propose that the sleep disruption associated with periodic limb movement disorder and restless legs syndrome and the motor restlessness of restless legs syndrome while awake could contribute to the inattention and hyperactivity seen in a subgroup of ADHD-diagnosed children.

CONTEXT: Little is known about the impact biomechanics sustained by players during interscholastic football. OBJECTIVE: To characterize the location and magnitude of impacts sustained by players during an interscholastic football season. DESIGN: Observational design. SETTING: On the field. PATIENTS OR OTHER PARTICIPANTS: High school varsity football team (n = 35; age = 16.85 +/- 0.75 years, height = 183.49 +/- 5.31 cm, mass = 89.42 +/- 12.88 kg). MAIN OUTCOME MEASURE(S): Biomechanical variables (linear acceleration, rotational acceleration, jerk, force, impulse, and impact duration) related to head impacts were categorized by session type, player position, and helmet impact location. RESULTS: Differences in grouping variables were found for each impact descriptor. Impacts occurred more frequently and with greater intensity during games. Linear acceleration was greatest in defensive linemen and offensive skill players and when the impact occurred at the top of the helmet. The largest rotational acceleration occurred in defensive linemen and with impacts to the front of the helmet. Impacts with the highest-magnitude jerk, force, and impulse and shortest duration occurred in the offensive skill, defensive line, offensive line, and defensive skill players, respectively. Top-of-the-helmet impacts yielded the greatest magnitude for the same variables. CONCLUSIONS: We are the first to provide a biomechanical characterization of head impacts in an interscholastic football team across a season of play. The intensity of game play manifested with more frequent and intense impacts. The highest-magnitude variables were distributed across all player groups, but impacts to the top of the helmet yielded the highest values. These high school football athletes appeared to sustain greater accelerations after impact than their older counterparts did. How this finding relates to concussion occurrence has yet to be elucidated.

Fourteen consecutive children who were newly diagnosed with attention-deficit hyperactivity disorder (ADHD) and who had never been exposed to stimulants and 10 control children without ADHD underwent polysomnographic studies to quantify Periodic Limb Movements in Sleep (PLMS) and arousals. Parents commonly gave both false-negative and false-positive reports of PLMS in their children, and a sleep study was necessary to confirm their presence or absence. The prevalence of PLMS on polysomnography was higher in the children with ADHD than in the control subjects. Nine of 14 (64%) children with ADHD had PLMS at a rate of >5 per hour of sleep compared with none of the control children (p <0.0015). Three of 14 children with ADHD (21%) had PLMS at a rate of >20 per hour of sleep. Many of the PLMS in the children with ADHD were associated with arousals. Historical sleep times were less for children with ADHD. The children with ADHD who had PLMS chronically got 43 minutes less sleep at home than the control subjects (p = 0.0091). All nine children with ADHD who had a PLMS index of >5 per hour of sleep had a long-standing clinical history of sleep onset problems (>30 minutes) and/or maintenance problems (more than two full awakenings nightly) thus meeting the criteria for Periodic Limb Movement Disorder (PLMD). None of the control children had a clinical history of sleep onset or maintenance problems. The parents of the children with ADHD were more likely to have restless legs syndrome (RLS) than the parents of the control children. Twenty-five of 28 biologic parents of the children with ADHD and all of the biologic parents of the control children were reached for interview. Eight of twenty-five parents of the children with ADHD (32%) had symptoms of RLS as opposed to none of the control parents (p = 0.011). PLMS may directly lead to symptoms of ADHD through the mechanism of sleep disruption. Alternative explanations for the association between ADHD and RLS/PLMS are that they are genetically linked, they share a common dopaminergic deficit, or both.

This paper reviews evidence from April, 1998 through April 2002 for the dopaminergic treatment of the restless legs syndrome (RLS) and periodic limb movement disorder (PLMD). There has been increased study of dopaminergic agents for the treatment of these conditions since publication of a review paper and practice parameters that covered all types of medical treatment of RLS and PLMD in 1999. For this reason, the Restless Legs Syndrome Task Force and the Standards of Practice Committee decided to update the evidence on dopaminergic treatment of these conditions. This paper reviews the literature on levodopa, dopaminergic agonists (pergolide, pramipexole, ropinirole, talipexole, cabergoline, piribidel, DHEC), and other dopaminergic agents (amantadine, selegiline).

Elevated concentration of plasma total homocysteine (tHcy) is a common risk factor for arterial occlusive diseases. Folic acid (FA) supplementation usually lowers tHcy levels, but initial tHcy and vitamin levels, multivitamin use, and polymorphisms in the gene for 5, 10-methylenetetrahydrofolate reductase (MTHFR) may contribute to variability in reduction. We tested the effects of a 3-week daily intake of 1 or 2 mg of FA supplements on tHcy levels in patients with and without coronary heart disease (CHD) who were analyzed for the C677T MTHFR mutation. Prior multivitamin intake and baseline vitamin and tHcy levels were also compared with responsiveness to folate supplementation. Both dosages of FA lowered tHcy levels similarly, regardless of sex, age, CHD status, body mass index, smoking, or plasma creatinine concentration. In non-multivitamin users, FA supplements reduced tHcy by 7% in C/C homozygotes and by 13% or 21% in subjects with one or two copies of the T677 allele, respectively; the corresponding reductions were smaller in users of multivitamins. Moreover, T/T homozygotes had elevated tHcy and increased susceptibility to high levels of tHcy at marginally low plasma folate levels, as well as enhanced response to the tHcy-lowering effects of FA. Although other factors are probably involved in the responsiveness of tHcy levels to FA supplementation, about one third of heterogeneity in responsiveness was attributable to baseline tHcy and folate levels and to multivitamin use.

Abstract Nitric oxide (NO) is one of the most important molecules released by endothelial cells, and its antiatherogenic properties support cardiovascular homeostasis. Diminished NO bioavailability is a common hallmark of endothelial dysfunction underlying the pathogenesis of the cardiovascular disease. Vascular NO is synthesized by endothelial nitric oxide synthase (eNOS) from the substrate L-arginine (L-Arg), with tetrahydrobiopterin (BH 4 ) as an essential cofactor. Cardiovascular risk factors such as diabetes, dyslipidemia, hypertension, aging, or smoking increase vascular oxidative stress that strongly affects eNOS activity and leads to eNOS uncoupling. Uncoupled eNOS produces superoxide anion (O 2 − ) instead of NO, thus becoming a source of harmful free radicals exacerbating the oxidative stress further. eNOS uncoupling is thought to be one of the major underlying causes of endothelial dysfunction observed in the pathogenesis of vascular diseases. Here, we discuss the main mechanisms of eNOS uncoupling, including oxidative depletion of the critical eNOS cofactor BH 4 , deficiency of eNOS substrate L-Arg, or accumulation of its analog asymmetrical dimethylarginine (ADMA), and eNOS S-glutathionylation. Moreover, potential therapeutic approaches that prevent eNOS uncoupling by improving cofactor availability, restoration of L-Arg/ADMA ratio, or modulation of eNOS S-glutathionylation are briefly outlined.

INTRODUCTION: Sport concussion represents the majority of brain injuries occurring in the United States with 1.6–3.8 million cases annually. Understanding the biomechanical properties of this injury will support the development of better diagnostics and preventative techniques. METHODS: We monitored all football related head impacts in 78 high school athletes (mean age = 16.7 yr) from 2005 to 2008 to better understand the biomechanical characteristics of concussive impacts. RESULTS: Using the Head Impact Telemetry System, a total of 54,247 impacts were recorded, and 13 concussive episodes were captured for analysis. A classification and regression tree analysis of impacts indicated that rotational acceleration (95582.3 rad·s−²), linear acceleration (996.1g), and impact location (front, top, and back) yielded the highest predictive value of concussion. CONCLUSIONS: These threshold values are nearly identical with those reported at the collegiate and professional level. If the Head Impact Telemetry System were implemented for medical use, sideline personnel can expect to diagnose one of every five athletes with a concussion when the impact exceeds these tolerance levels. Why all athletes did not sustain a concussion when the impacts generated variables in excess of our threshold criteria is not entirely clear, although individual differences between participants may play a role. A similar threshold to concussion in adolescent athletes compared with their collegiate and professional counterparts suggests an equal concussion risk at all levels of play.

STUDY OBJECTIVES: To review the literature on restless legs syndrome (RLS), periodic limb movements in sleep, and depression. DESIGN: Literature review. SETTING, PARTICIPANTS, AND INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: We conducted a comprehensive review of the literature searching for publications that included data on depression or antidepressants and RLS or periodic limb movements in sleep. Sixty-two relevant literature references were found and reviewed. Four population-based studies and 9 clinical studies reported significantly higher rates of depression symptoms in individuals with RLS than in controls. Conversely, the prevalence of RLS in patients presenting with depression was reported as elevated in 2 studies. Conflicting data were found regarding the effect of antidepressants on the sensory symptoms of RLS. In contrast, several studies have found that selective serotonin reuptake inhibitor antidepressant use is associated with increased periodic limb movements in sleep. CONCLUSIONS: Depression symptoms are common in adults with RLS. However, the relationship appears complex, with overlap between RLS- and depression-related symptoms confounding the issue. Given what is known at this time, we propose a specific treatment approach to patients with RLS and depression symptoms.

This paper, and the two which will follow it (1, 2), deal with the intestinal mode of acute radiation death. Some new observations will be presented. However, this paper is mainly concerned with the relations between observed facts. It is an attempt to give a coherent account of one mode of radiation death, studied at various levels of organization from the cell to the whole organism. We shall try to identify the critical event on the cellular level; to trace its effects through the biology of the tissue involved, the intestinal epithelium; to relate the tissue changes to responses of the whole intestine; and to see in what manner the organ changes are responsible for the death of the whole animal. The picture is rough and unfinished in spots, but it leads to an interpretation which, though tentative, is unified. Some years ago, ‘‘acute radiation death’’ was, to most investigators, simply that mode of death which occurs after whole-body irradiation with X-rays or c-rays, with doses in the neighborhood of the LD50. This has changed. Since investigations have been extended to wider dosage domains, more species, a wider range of conditions, and, in particular, since it has become possible to prevent marrow death by specific treatments, other modes of radiation death have grown in importance. This has created a need for more precise concepts. A particular mode of acute radiation death occurs if a particular component of the acute radiation syndrome is severe enough to cause death. The isolation of a particular process can be difficult. Any mode can be expressed only if not masked by another lethal process. A faster process masks a slower one; a more sensitive process, a less sensitive one. For instance, death due to late changes of the central nervous system cannot be observed after wholebody irradiation; it is masked by marrow death. Therapeutic measures, or modifications of the radiation conditions, may unmask modes of radiation death which are not expressed under standard conditions. For instance, oral radiation death can be unmasked by treatment with spleen, or by regional irradiation. Use of fast neutrons brings out a mode of death which is recessive after treatment with X-rays and c-rays (3–6). Under the conditions most commonly used, marrow death masks all other modes (7).

Abstract We previously reported that patients with fibrotic, chronic graft-versus-host disease (cGVHD) have antibodies activating the platelet-derived growth factor receptor pathway. Because this pathway can be inhibited by imatinib, we performed a pilot study including 19 patients with refractory cGVHD, given imatinib at a starting dose of 100 mg per day. All patients had active cGVHD with measurable involvement of skin or other districts and had previously failed at least 2 treatment lines. Patient median age was 29 years (range, 10-62 years), and median duration of cGvHD was 37 months (range, 4-107 months). The organs involved were skin (n = 17), lung (n = 11), and bowel (n = 5); 15 patients had sicca syndrome. Imatinib-related, grade 3 to 4 toxicity included fluid retention, infections, and anemia. Imatinib was discontinued in 8 patients: in 3 because of toxicity and in 5 because of lack of response (n = 3) or relapse of malignancy (n = 2). Overall response rate at 6 months was 79%, with 7 complete remissions (CRs) and 8 partial remissions (PRs). With a median follow-up of 17 months, 16 patients are alive, 14 still in CR or PR. The 18-month probability of overall survival is 84%. This study suggests that imatinib is a promising treatment for patients with refractory fibrotic cGVHD.

BACKGROUND: Specific diagnostic criteria for pediatric restless legs syndrome (RLS) were published in 2003 following a workshop at the National Institutes of Health. Due to substantial new research and revision of the adult RLS diagnostic criteria, a task force was chosen by the International Restless Legs Syndrome Study Group (IRLSSG) to consider updates to the pediatric diagnostic criteria. METHODS: A committee of seven pediatric RLS experts developed a set of 15 consensus questions to review, conducted a comprehensive literature search, and extensively discussed potential revisions. The committee recommendations were approved by the IRLSSG executive committee and reviewed by the IRLSSG membership. RESULTS: The pediatric RLS diagnostic criteria were simplified and integrated with the newly revised adult RLS criteria. Specific recommendations were developed for pediatric application of the criteria, including consideration of typical words used by children to describe their symptoms. Pediatric aspects of differential diagnosis, comorbidity, and clinical significance were then defined. In addition, the research criteria for probable and possible pediatric RLS were updated and criteria for a related condition, periodic limb movement disorder (PLMD), were clarified. CONCLUSIONS: Revised diagnostic criteria for pediatric RLS have been developed, which are intended to improve clinical practice and promote further research.

Osteosarcoma is one of the most common primary tumours of the bone, with a 5-year survival rate of less than 20% after the development of metastases. Osteosarcoma is highly predisposed in Paget's disease of the bone, and both have common characteristic skeletal features due to rapid bone remodelling. Osteosarcoma prognosis is location dependent, which further emphasizes the likely contribution of the bone microenvironment in its pathogenesis. Mechanobiology describes the processes involved when mechanical cues from the changing physical microenvironment of the bone are transduced to biological pathways through mechanosensitive cellular components. Mechanobiology-driven therapies have been used to curb tumour progression by direct alteration of the physical microenvironment or inhibition of metastasis-associated mechanosensitive proteins. This review emphasizes the contribution of mechanobiology to the progression of osteosarcoma and sheds light on current mechanobiology-based therapies and potential new targets for improving disease management. Additionally, the many different 3D models currently used to study osteosarcoma mechanobiology are summarized.