Multicenter Evaluation of Ultra-Rapid Lispro Insulin with Control-IQ Technology in Adults, Adolescents, and Children with Type 1 Diabetes

Objective: To evaluate the safety and explore the efficacy of use of ultra-rapid lispro (URLi, Lyumjev) insulin in the Tandem t:slim X2 insulin pump with Control-IQ 1.5 technology in children, teenagers, and adults living with type 1 diabetes (T1D). Methods: At 14 U.S. diabetes centers, youth and adults with T1D completed a 16-day lead-in period using lispro in a t:slim X2 insulin pump with Control-IQ 1.5 technology, followed by a 13-week period in which URLi insulin was used in the pump. Results: The trial included 179 individuals with T1D (age 6-75 years). With URLi, 1.7% (3 participants) had a severe hypoglycemia event over 13 weeks attributed to override boluses or a missed meal. No diabetic ketoacidosis events occurred. Two participants stopped URLi use because of infusion-site discomfort, and one stopped after developing a rash. Mean time 70-180 mg/dL increased from 65% ± 15% with lispro to 67% ± 13% with URLi (P = 0.004). Mean insulin treatment satisfaction questionnaire score improved from 75 ± 13 at screening to 80 ± 11 after 13 weeks of URLi use (mean difference = 6; 95% confidence interval 4-8; P < 0.001), with the greatest improvement reported for confidence avoiding symptoms of high blood sugar. Mean treatment-related impact measure-diabetes score improved from 74 ± 12 to 80 ± 12 (P < 0.001), and mean TRIM-Diabetes Device (score improved from 82 ± 11 to 86 ± 12 (P < 0.001). Conclusions: URLi use in the Tandem t:slim X2 insulin pump with Control-IQ 1.5 technology was safe for adult and pediatric participants with T1D, with quality-of-life benefits of URLi use perceived by the study participants. Clinicaltrials.gov registration: NCT05403502.

Development of a Real-time Force-based Algorithm for Infusion Failure Detection

BACKGROUND

Continuous subcutaneous insulin infusion (CSII) is a common treatment option for people with diabetes (PWD), but insulin infusion failures pose a significant challenge, leading to hyperglycemia, diabetes burnout, and increased hospitalizations. Current CSII pumps' occlusion alarm systems are limited in detecting infusion failures; therefore, a more effective detection method is needed.

METHODS

We conducted five preclinical animal studies to collect data on infusion failures, utilizing both insulin and non-insulin boluses. Data were captured using in-line pressure and flow rate sensors, with additional force data from CSII pumps' onboard sensors in one study. A novel classifier model was developed using this dataset, aimed at detecting different types of infusion failures through direct utilization of force sensor data. Performance was compared against various occlusion alarm thresholds from commercially available CSII pumps.

RESULTS

The testing dataset included 251 boluses. The Bagging classifier model showed the highest performance metrics among the models tested, exhibiting high accuracy (96%), sensitivity (94%), and specificity (98%), with lower false-positive and false-negative rate compared with traditional occlusion alarm pressure thresholds.

CONCLUSIONS

Our study developed a novel non-threshold classifier that outperforms current occlusion alarm systems in CSII pumps in detecting infusion failures. This advancement has the potential to reduce the risk of hyperglycemia and hospitalizations due to undetected infusion failures, offering a more reliable and effective CSII therapy for PWD. Further studies involving human participants are recommended to validate these findings and assess the classifier's performance in a real-world setting.

Automated Insulin Delivery with Remote Real-Time Continuous Glucose Monitoring for Hospitalized Patients with Diabetes: A Multicenter, Single-Arm, Feasibility Trial

Introduction: Multiple daily injection insulin therapy frequently fails to meet hospital glycemic goals and is prone to hypoglycemia. Automated insulin delivery (AID) with remote glucose monitoring offers a solution to these shortcomings. Research Design and Methods: In a single-arm multicenter pilot trial, we tested the feasibility, safety, and effectiveness of the Omnipod 5 AID System with real-time continuous glucose monitoring (CGM) for up to 10 days in hospitalized patients with insulin-requiring diabetes on nonintensive care unit medical-surgical units. Primary endpoints included the proportion of time in automated mode and percent time-in-range (TIR 70-180 mg/dL) among participants with >48 h of CGM data. Safety endpoints included incidence of severe hypoglycemia and diabetes-related ketoacidosis (DKA). Additional glycemic endpoints, CGM accuracy, and patient satisfaction were also explored. Results: Twenty-two participants were enrolled; 18 used the system for a total of 96 days (mean 5.3 ± 3.1 days per patient), and 16 had sufficient CGM data required for analysis. Median percent time in automated mode was 95% (interquartile range 92%-98%) for the 18 system users, and the 16 participants with >48 h of CGM data achieved an overall TIR of 68% ± 16%, with 0.17% ± 0.3% time <70 mg/dL and 0.06% ± 0.2% time <54 mg/dL. Sensor mean glucose was 167 ± 21 mg/dL. There were no DKA or severe hypoglycemic events. All participants reported satisfaction with the system at study end. Conclusions: The use of AID with a disposable tubeless patch-pump along with remote real-time CGM is feasible in the hospital setting. These results warrant further investigation in randomized trials.

Frequency and Detection of Insulin Infusion Site Failure in the Type 1 Diabetes Exchange Online Community

Insulin infusion site (IIS) failures are a weakness in insulin pump therapy. We examined experience with IIS failures among U.S. individuals with diabetes on insulin pump through survey distributed to the T1D Exchange Online Community. Demographic factors, IIS characteristics, and diabetes-related perceptions were assessed by logistic regression to determine odds of higher (≥1 per month) or lower (<1 per month) reported IIS failure frequency. IIS failures were common; 41.4% reported ≥1 per month. IIS failure is usually detected through development of hyperglycemia rather than pump alarm. No assessed demographic factor or IIS characteristic was predictive; however, higher odds of ≥1 failure per month were associated with feelings of burnout (odds ratios [OR] 1.489 [1.024, 2.165]) and considering pump discontinuation (OR 2.233 [1.455, 3.427]). IIS failures are frequent and unpredictable, typically require hyperglycemia for detection, and are associated with negative perceptions. More should be done toward preventing IIS failures and/or detecting them sooner.

Allogeneic Blood or Marrow Transplantation with Post-Transplantation Cyclophosphamide for Peripheral T Cell Lymphoma: The Importance of Graft Source

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus host-disease (GVHD) prophylaxis has revolutionized allogeneic blood or marrow transplantation (alloBMT), but there is limited published experience in peripheral T cell lymphoma (PTCL). We sought to assess outcomes in patients with PTCL who underwent alloBMT with PTCy. We reviewed the charts of all adult patients age ≥18 years who underwent alloBMT with nonmyeloablative conditioning and PTCy-based GVHD prophylaxis at the Sidney Kimmel Comprehensive Cancer Center between January 2004 and December 2020. Sixty-five patients were identified. The median age was 59 years (range, 24 to 75 years). Lymphoma histology included PTCL not otherwise specified (n = 24), anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (n = 14), angioimmunoblastic T cell lymphoma (n = 7), enteropathy-associated T cell lymphoma (n = 6), hepatosplenic T cell lymphoma (n = 4), and others (n = 10). Eleven patients were in first complete remission (17%); the remaining patients were in first partial remission or underwent salvage therapy to at least PR prior to transplantation. Forty-eight patients underwent alloBMT from a haploidentical related donor (74%), 10 from a fully matched donor (15%), and 7 from a mismatched unrelated donor (11%). All patients received fludarabine, cyclophosphamide, and total body irradiation (TBI). The graft source was bone marrow (BM) in 46 patients (71%) and peripheral blood (PB) in 19 patients (29%); all patients in the BM cohort received 200 cGy TBI, and most patients in the PB cohort (15 of 19) received 400 cGy TBI. GVHD prophylaxis comprised PTCy, mycophenolate mofetil, and a calcineurin inhibitor or sirolimus. With a median follow-up of 2.8 years (range, 290 days to 14.2 years), the 2-year progression-free survival (PFS) for the entire cohort was 49% (95% confidence interval [CI], 38% to 64%), and the 2-year overall survival (OS) was 55% (95% CI, 44% to 69%). Outcomes were significantly improved in those receiving PB compared to those receiving BM, including a 2-year PFS of 79% (95% CI 63% to 100%) versus 39% (95% CI, 27% to 56%), 2-year OS of 84% (95% CI, 69% to 100%) versus 46% (95% CI, 33% to 63%), and 1-year cumulative incidence of relapse of 5% (95% CI, 0 to 16%) versus 33% (95% CI, 19% to 46%), with no difference in GVHD and nonrelapse mortality. AlloBMT with PTCy is safe and well-tolerated in patients with PTCL. Our data suggest that increasing the TBI dose to 400 cGy and using PB allografts may offer improved disease control and better survival outcomes, though additional studies are needed to confirm these findings.

Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes

BACKGROUND

Currently available semiautomated insulin-delivery systems require individualized insulin regimens for the initialization of therapy and meal doses based on carbohydrate counting for routine operation. In contrast, the bionic pancreas is initialized only on the basis of body weight, makes all dose decisions and delivers insulin autonomously, and uses meal announcements without carbohydrate counting.

METHODS

In this 13-week, multicenter, randomized trial, we randomly assigned in a 2:1 ratio persons at least 6 years of age with type 1 diabetes either to receive bionic pancreas treatment with insulin aspart or insulin lispro or to receive standard care (defined as any insulin-delivery method with unblinded, real-time continuous glucose monitoring). The primary outcome was the glycated hemoglobin level at 13 weeks. The key secondary outcome was the percentage of time that the glucose level as assessed by continuous glucose monitoring was below 54 mg per deciliter; the prespecified noninferiority limit for this outcome was 1 percentage point. Safety was also assessed.

RESULTS

A total of 219 participants 6 to 79 years of age were assigned to the bionic-pancreas group, and 107 to the standard-care group. The glycated hemoglobin level decreased from 7.9% to 7.3% in the bionic-pancreas group and did not change (was at 7.7% at both time points) in the standard-care group (mean adjusted difference at 13 weeks, -0.5 percentage points; 95% confidence interval [CI], -0.6 to -0.3; P<0.001). The percentage of time that the glucose level as assessed by continuous glucose monitoring was below 54 mg per deciliter did not differ significantly between the two groups (13-week adjusted difference, 0.0 percentage points; 95% CI, -0.1 to 0.04; P<0.001 for noninferiority). The rate of severe hypoglycemia was 17.7 events per 100 participant-years in the bionic-pancreas group and 10.8 events per 100 participant-years in the standard-care group (P = 0.39). No episodes of diabetic ketoacidosis occurred in either group.

CONCLUSIONS

In this 13-week, randomized trial involving adults and children with type 1 diabetes, use of a bionic pancreas was associated with a greater reduction than standard care in the glycated hemoglobin level. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; ClinicalTrials.gov number, NCT04200313.).

Checking the Checkpoint Inhibitors: A Case of Autoimmune Diabetes After PD-1 Inhibition in a Patient with HIV

Immune checkpoint inhibitor-associated diabetes mellitus (ICI-DM) is a known immune-related adverse event (irAE) following treatment with programmed cell death protein 1 (PD-1), with a reported 0.9% incidence. We hereby present the first case, to our knowledge, of ICI-DM following ICI use in a human immunodeficiency virus (HIV) patient. In this case, a 48-year-old man with HIV stable on highly active antiretroviral therapy (HAART) was diagnosed with Hodgkin lymphoma and initiated treatment with the PD-1 inhibitor nivolumab. His lymphoma achieved complete response after 5 months. However, at month 8, he reported sudden polydipsia and polyuria. Labs revealed a glucose level of 764 mg/dL and glycated hemoglobin A1c (HbA1c) of 7.1%. Low C-peptide and elevated glutamic acid decarboxylase 65 (GAD65) antibody levels confirmed autoimmune DM, and he was started on insulin. Major histocompatibility complex class II genetic analysis revealed homozygous HLA DRB1*03-DQA1*0501-DQB1*02 (DR3-DQ2), which is a known primary driver of genetic susceptibility to type 1 DM. Autoimmune DM has been reported as an ICI-associated irAE. However, patients with immunocompromising conditions such as HIV are usually excluded from ICI trials. Therefore, little is known about such irAEs in this population. In this case, risk of ICI-DM as an irAE was likely increased by several factors including family history, a high-risk genetic profile, islet-related immunologic abnormalities, active lymphoma, and HIV infection with a possible immune reconstitution event. Clinicians should maintain a high index of suspicion for development of irAEs associated with ICI, particularly as use of these therapies broadens. Thorough investigation for presence of higher-risk features should be conducted and may warrant inclusion of pre-therapy genetic and/or autoantibody screening.

Open Reduction and Suture Fixation of Acute Sternoclavicular Fracture-Dislocations in Children

Background

Acute sternoclavicular fracture-dislocation is associated with high-energy trauma and is being increasingly recognized in children¹. These injuries are associated with compression of mediastinal structures and can be life-threatening¹. The management of acute sternoclavicular fracture-dislocation includes closed reduction or open surgical stabilization; however, limited success is reported with closed reduction^2,3. To our knowledge, there are no detailed descriptions of open reduction and suture fixation of acute sternoclavicular fracture-dislocation in children.

Description

Following diagnosis of acute sternoclavicular fracture-dislocation, the timing of surgical treatment is determined according to several patient and surgical factors. Among patients with hemodynamic instability, respiratory compromise, or evidence of asymmetric perfusion, surgical treatment is needed on an emergency basis. In the absence of these factors, surgical treatment can be performed on an urgent basis. It is important to communicate with vascular or thoracic surgeons prior to proceeding to the operating room because of the rare case in which advanced surgical access or vascular repair is required. In the operating room, general anesthesia and large-bore intravenous access are required. Patients are positioned supine on a radiolucent table, and a small bump is placed between the scapulae to elevate the medial aspect of the clavicle. The contralateral sternoclavicular joint and medial aspect of the clavicle should be prepared into the sterile field, as well as both sides of the groin in case vascular access is needed. A 6 to 8-cm incision is centered on the medial aspect of the clavicle, extending to the manubrium. Standard dissection to the clavicle is performed, and care is taken to maintain the integrity of the sternoclavicular ligament complex. Circumferential dissection of the medial clavicular metaphysis is usually required in order to mobilize the dislocated fragment. Reduction of the physeal fracture usually requires axial traction and extension of the ipsilateral shoulder with the aid of a reduction clamp on the medial clavicular metaphysis. In some cases, a Freer elevator can be placed between the metaphysis and epiphysis to shoehorn the clavicle from posterior to anterior. Once reduced, the fracture-dislocation is usually stable; however, the reduction is augmented with suture fixation. The sternoclavicular joint capsule should be repaired if disrupted, and the incision should be closed in layers. Postoperatively, the arm is placed in a sling, and range of motion is commenced at 4 weeks.

Alternatives

Alternative management of acute sternoclavicular fracture-dislocation includes closed reduction, plate fixation⁴, and ligament reconstruction⁵.

Rationale

In our experience, closed reduction is often unsuccessful, which is consistent with the experiences reported by other authors^2,3. In addition, suture fixation is sufficient and plate fixation is not required because this injury is relatively stable following reduction. Lastly, ligament reconstruction with use of autograft or allograft may be indicated but is more relevant in chronic cases with injury or attenuation of the sternoclavicular ligament complex. Open reduction allows for direct visualization of the fracture reduction, and suture fixation allows for increased stability without the need for hardware or secondary surgical procedures.

Expected Outcomes

We expect patients to achieve full range of motion and strength without any joint instability as reported by Waters et al.³.

Important Tips

There is an inherent risk of vascular injury with open reduction and suture fixation. This risk is mitigated with perioperative planning and consultation with vascular or thoracic surgeons. General surgeons should always be available when these procedures are performed in case of vascular issues or emergencies.It is sometimes difficult to reduce the dislocation, but additional maneuvers allow for controlled reduction of the displaced clavicle, such as using a Freer elevator and serrated clamp.Assessing fracture reduction can be difficult intraoperatively. Including the contralateral sternoclavicular joint in the sterile surgical field can be helpful in assessing fracture reduction and osseous contour.

Application of entropy and signal energy for ultrasound-based classification of three-dimensional printed polyetherketoneketone components

This paper describes a preliminary method for the classification of annealed and unannealed polyetherketoneketone (PEKK) components manufactured using a material extrusion three-dimensional (3D) printing process. PEKK is representative of a class of high-performance thermoplastics that are increasingly employed as feedstocks for use in 3D printing. PEKK components may be used continuously at elevated temperatures, are chemically resistant, and able to withstand large mechanical loads. These properties render PEKK suitable as a metal component replacement in aerospace applications, high-temperature industrial applications, and surgical implants. The structure of PEKK is semi-crystalline with the specific crystallinity correlating to the final properties during application, making determination of this property crucial. This study compares three different signal processing techniques intended to distinguish annealed (high crystallinity) from unannealed (low crystallinity) components using backscattered ultrasound. The first is energy-based and is unable to detect annealing. The second two are based on different entropies of the backscattered signal: a limiting form of Renyi's entropy and a limiting form of joint entropy. The joint entropy values for the annealed and unannealed specimens fall into two non-overlapping intervals and have a statistical separation of two standard deviations.

Percutaneous Pinning of Pediatric Proximal Humeral Fractures

Background

Proximal humeral fractures are relatively common in pediatric patients. These injuries are usually treated nonoperatively in younger children or children with minimally displaced fractures. However, closed reduction or open reduction followed by percutaneous pinning is recommended for older children with displaced fractures. Percutaneous pinning has several advantages, but there are limited reports of a safe and reliable surgical technique in the literature.

Description

Patients are positioned in a modified beach-chair position to allow orthogonal imaging. The injured extremity is draped free from the remainder of the body. Closed reduction, which comprises a combination of traction, abduction, and rotation, is attempted. Internal or external rotation may be required, depending on the fracture line and deforming forces. If an anatomic closed reduction cannot be obtained, a block to reduction should be suspected and open reduction should be performed via a deltopectoral approach. Once the fracture is reduced, two 2.5-mm threaded Kirschner wires from the small external fixator set are used to percutaneously fix the fracture. Any small external fixator set can be used, and if not available, individual threaded wires of similar size can be used. Alternatively, Kirschner wires can be advanced to the fracture site prior to reduction and then advanced into the humeral epiphysis once the fracture is reduced. Care is taken to avoid the axillary nerve, which is reliably within 6 cm of the anterolateral aspect of the acromion, and wires are placed distal to this site. Once pin position has been confirmed radiographically, the construct is secured with pin-to-pin clamps to improve rigidity and further decrease the risk of pin migration. A soft dressing and shoulder immobilizer are placed postoperatively. Patients are followed with biweekly radiographs, and pins are removed in the outpatient office or under conscious sedation at 4 weeks. Leaving pins for a longer period may increase the risk of skin irritation and potentially infection.

Alternatives

Alternatives to closed reduction or open reduction and percutaneous pinning include nonoperative management and elastic intramedullary nailing. Nonoperative treatment is a reliable option for most patients. However, it is not suitable for older children with severely displaced fractures because of diminished remodeling potential. Elastic intramedullary nailing is a good option for distal fractures. However, it is not suitable for proximal fractures, and it has been associated with longer operative times and more blood loss than percutaneous pinning. It also requires a second procedure.

Rationale

This procedure allows for anatomic fixation of proximal humeral fractures and provides a rigid construct to maintain reduction. It is not technically challenging, requires limited postoperative immobilization, and decreases the risk of a second general anesthetic.

Budesonide treatment for microscopic colitis from immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (CPIs) are effective against a variety of malignancies but can be limited by inflammatory toxicities such as enterocolitis. Enterocolitis is typically treated with systemically active glucocorticoids. Endoscopy can stratify patients by the severity of mucosal inflammation, including identifying patients with colitis in the absence of visible mucosal changes: microscopic colitis. Whether patients with CPI microscopic colitis could be managed differently from colitis with more severe mucosal involvement is unclear. The objective of this study was to describe outcomes in CPI microscopic colitis focusing on the response to first line treatment with budesonide.

METHODS

We evaluated data from a retrospective cohort from a single-center large academic hospital. The participants were all adult patients evaluated by endoscopy for suspected CPI enterocolitis between 3/2017 and 3/2019. The exposures were: Mayo Endoscopic Score (range 0-3). The subset was: oral budesonide, maximum dose 12 mg daily, administered minimum of 5 weeks. The main outcomes and measures were: Primary: time from first CPI exposure to first glucocorticoid use; use of systemic glucocorticoids; time from symptom onset to resolution; continuation of CPI therapy; number of additional CPI infusions received. Secondary: admissions for symptom control; novel irAE development; need for second-line immunosuppression; oncologic outcomes.

RESULTS

We identified 38 patients with biopsy confirmed CPI enterocolitis, 13 in the microscopic colitis cohort, and 25 in the non-microscopic colitis cohort. Budesonide use was higher in the microscopic colitis cohort (12/13 vs 3/25, p < 0.001), and systemic glucocorticoid use was higher in non-microscopic colitis (22/25 vs. 3/13, p < 0.001). Time from symptom onset to resolution did not differ. Microscopic colitis patients more frequently remained on CPI after developing (entero)colitis (76.9% vs 16.0%, p < 0.001). Microscopic colitis patients tolerating further CPI received, on average, 4.2 CPI infusions more than non-microscopic colitis patients tolerating CPI (5.8 vs 1.6, p = 0.03). Microscopic colitis was associated with increased time-to-treatment-failure (HR 0.30, 95% CI 0.14-0.66) and progression-free survival (HR 0.22, 95% CI 0.07-0.70).

CONCLUSIONS

Gastrointestinal mucosal inflammation without visible mucosal injury is a distinct, prevalent CPI enterocolitis subset that can be diagnosed by endoscopy. First-line budesonide appears effective in controlling "microscopic colitis" symptoms and prolonging immunotherapy duration. These findings present a compelling rationale for routine endoscopic evaluation of suspected CPI enterocolitis and suggest an alternative glucocorticoid-sparing treatment strategy for a subset of such patients.

Colitis after checkpoint blockade: A retrospective cohort study of melanoma patients requiring admission for symptom control

BACKGROUND

Immune checkpoint inhibitors (CPIs) have revolutionized oncologic therapy but can lead to immune-related adverse events (irAEs). Corticosteroids are first-line treatment with escalation to biologic immunosuppression in refractory cases. CPI-related gastroenterocolitis (GEC) affects 20%-50% of patients receiving CPIs and can carry significant morbidity and mortality. Severe CPI-related GEC is not well-described. We present the clinical characterization of all CPI-related GEC requiring admission at a single institution.

METHODS

Clinical, laboratory, radiographic, and endoscopic data were extracted from charts of all melanoma patients ≥18 years of age admitted to one institution for CPI-related GEC, from February 5, 2011 to December 13, 2016. Patients were followed until December 31, 2017 for further admissions. Survival, outcomes, and pharmaceutical-use analyses were performed.

RESULTS

Median time-to-admission from initial CPI exposure was 73.5 days. Median length of stay was 4.5 days. About 50.0% required second-line immunosuppression. Readmission for recrudescence occurred in 33.3%. Common Terminology Criteria for Adverse Events (CTCAE) grade was not significantly associated with outcomes. Hypoalbuminemia (P = 0.005), relative lymphopenia (P = 0.027), and decreased lactate dehydrogenase (P = 0.026) were associated with second-line immunosuppression. There was no difference in progression-free survival (PFS) or OS (P = 0.367, 0.400) for second-line immunosuppression. Subgroup analysis showed that early corticosteroid administration (P = 0.045) was associated with decreased PFS.

CONCLUSIONS

Severe CPI-related GEC typically manifests within 3 months of immunotherapy exposure. Rates of second-line immunosuppression and readmission for recrudescence were high. CTCAE grade did not capture the degree of severity in our cohort. Second-line immunosuppression was not associated with poorer oncologic outcomes; however, early corticosteroid exposure was associated with decreased PFS. Further investigation is warranted.

Broodstock History Strongly Influences Natural Spawning Success in Hatchery Steelhead (Oncorhynchus mykiss)

We used genetic parentage analysis of 6200 potential parents and 5497 juvenile offspring to evaluate the relative reproductive success of hatchery and natural steelhead (Onchorhynchus mykiss) when spawning in the wild between 2008 and 2011 in the Wenatchee River, Washington. Hatchery fish originating from two prior generation hatchery parents had <20% of the reproductive success of natural origin spawners. In contrast, hatchery females originating from a cross between two natural origin parents of the prior generation had equivalent or better reproductive success than natural origin females. Males originating from such a cross had reproductive success of 26–93% that of natural males. The reproductive success of hatchery females and males from crosses consisting of one natural origin fish and one hatchery origin fish was 24–54% that of natural fish. The strong influence of hatchery broodstock origin on reproductive success confirms similar results from a previous study of a different population of the same species and suggests a genetic basis for the low reproductive success of hatchery steelhead, although environmental factors cannot be entirely ruled out. In addition to broodstock origin, fish size, return time, age, and spawning location were significant predictors of reproductive success. Our results indicate that incorporating natural fish into hatchery broodstock is clearly beneficial for improving subsequent natural spawning success, even in a population that has a decades-long history of hatchery releases, as is the case in the Wenatchee River.

Entropy vs. Energy Waveform Processing: A Comparison Based on the Heat Equation

Virtually all modern imaging devices collect electromagnetic or acoustic waves and use the energy carried by these waves to determine pixel values to create what is basically an “energy” picture. However, waves also carry “information”, as quantified by some form of entropy, and this may also be used to produce an “information” image. Numerous published studies have demonstrated the advantages of entropy, or “information imaging”, over conventional methods. The most sensitive information measure appears to be the joint entropy of the collected wave and a reference signal. The sensitivity of repeated experimental observations of a slowly-changing quantity may be defined as the mean variation (i.e., observed change) divided by mean variance (i.e., noise). Wiener integration permits computation of the required mean values and variances as solutions to the heat equation, permitting estimation of their relative magnitudes. There always exists a reference, such that joint entropy has larger variation and smaller variance than the corresponding quantities for signal energy, matching observations of several studies. Moreover, a general prescription for finding an “optimal” reference for the joint entropy emerges, which also has been validated in several studies.

Additional results for "joint entropy of continuously differentiable ultrasonic waveforms" [J. Acoust. Soc. Am. 133(1), 283-300 (2013)]

Previous results on the use of joint entropy for detection of targeted nanoparticles accumulating in the neovasculature of MDA435 tumors [Fig. 7 of M. S. Hughes et al., J. Acoust. Soc. Am. 133, 283-300 (2013)] are extended, with sensitivity improving by nearly another factor of 2. This result is obtained using a "quasi-optimal" reference waveform in the computation of the joint entropy imaging technique used to image the accumulating nanoparticles.

Glioma diagnostics and biomarkers: an ongoing challenge in the field of medicine and science

Glioma is the most common brain tumor. For the more aggressive form, glioblastoma, standard treatment includes surgical resection, irradiation with adjuvant temozolomide and, on recurrence, experimental chemotherapy. However, the survival of patients remains poor. There is a critical need for minimally invasive biomarkers for diagnosis and as measures of response to therapeutic interventions. Glioma shed extracellular vesicles (EVs), which invade the surrounding tissue and circulate within both the cerebrospinal fluid and the systemic circulation. These tumor-derived EVs and their content serve as an attractive source of biomarkers. In this review, we discuss the current state of the art of biomarkers for glioma with emphasis on their EV derivation.

Valve-sparing aortic root replacement: early and midterm outcomes in 83 patients

BACKGROUND

Valve-sparing aortic root replacement (VSARR) is an alternative to traditional composite valve graft (CVG) root replacement. We examined early and midterm outcomes after VSARR.

METHODS

A combined retrospective/prospective study was performed in 83 patients who underwent VSARR (16%) among 515 patients who underwent aortic root replacement during a nearly 12-year period. Thirty-six patients (43%) had a connective tissue disorder, 3 patients (4%) had acute aortic dissection, and 40 (48%) patients had at least moderate aortic regurgitation (AR). Twenty-eight patients (34%) had left ventricular hypertrophy or dilatation. The reimplantation VSARR technique was used in 82 patients (99%), and the Florida sleeve technique was used in 1 patient. Thirty-two patients (39%) underwent concomitant aortic arch replacement. For early survivors, the median duration of follow-up was 3.5 years (range, 5 days-12.2 years).

RESULTS

One patient had severe AR after VSARR that necessitated intraoperative conversion to a mechanical CVG. The 1 operative death and 1 stroke occurred in a patient with acute dissection. Actuarial survival was 96.4%±2.0% at 2 years and 86.9%±5.6% at 8 years. Six patients (7%) had late valve-related complications: 1 died of endocarditis, 4 underwent reoperation for severe AR and received replacement valves, and 1 had severe AR and is being monitored. Freedom from repair failure (reoperation, endocarditis, or severe AR) was 94.8%±2.6% at 2 years and 87.3%±5.7% at 8 years.

CONCLUSIONS

Valve-sparing aortic root replacement can have excellent early and respectable midterm outcomes, even when combined with arch repair. Further follow-up remains necessary to evaluate the long-term durability of VSARR.

Orthopaedic injuries from deer stands and their functional outcomes

Hunters who fall from deer stands can sustain a variety of injuries. A retrospective review was conducted at a single institution to gauge the experience in treating patients injured in falls from deer stands from 2002 to 2008. Medical records were analyzed for patient demographics, tree stand characteristics, and injury details. Patients were contacted to complete a SF-12 health survey to assess their functional outcome following their injuries. Of the 30 patients who sustained a fracture, an average of 2.08 fractures were sustained per patient. Sixteen patients sustained a spinal column fracture, and four of these sustained a spinal cord injury. Twenty-one patients underwent at least one surgical procedure by the trauma surgery (two), neurosurgery (four), or orthopaedic surgery (15) teams. The importance of understanding deer stand instructions should be emphasized during hunting education classes, and all hunters should follow safe hunting recommendations pertaining to firearms and tree stands.

Joint entropy of continuously differentiable ultrasonic waveforms

This study is based on an extension of the concept of joint entropy of two random variables to continuous functions, such as backscattered ultrasound. For two continuous random variables, X and Y, the joint probability density p(x,y) is ordinarily a continuous function of x and y that takes on values in a two dimensional region of the real plane. However, in the case where X=f(t) and Y=g(t) are both continuously differentiable functions, X and Y are concentrated exclusively on a curve, γ(t)=(f(t),g(t)), in the x,y plane. This concentration can only be represented using a mathematically "singular" object such as a (Schwartz) distribution. Its use for imaging requires a coarse-graining operation, which is described in this study. Subsequently, removal of the coarse-graining parameter is accomplished using the ergodic theorem. The resulting expression for joint entropy is applied to several data sets, showing the utility of the concept for both materials characterization and detection of targeted liquid nanoparticle ultrasonic contrast agents. In all cases, the sensitivity of these techniques matches or exceeds, sometimes by a factor of two, that demonstrated in previous studies that employed signal energy or alternate entropic quantities.

Quantitative ultrasound of skeletal muscle: reliable measurements of calibrated muscle backscatter from different ultrasound systems

Widespread implementation of quantitative muscle ultrasonography in assessing skeletal muscle pathology is limited by an inability to replicate results between different ultrasound systems. We have developed a measurement of skeletal muscle pathology, calibrated muscle backscatter (cMB), which should be reproducible between different ultrasound systems. We compared the reliability of grayscale and cMB measurements between different ultrasound systems, configurations and region-of-interest (ROI) sizes. cMB of skeletal muscle was reliably measured (intraclass correlation coefficient [ICC] ≤0.98) despite very dissimilar grayscale levels (ICC ≤0.54). cMB reliability was highest between systems using similar settings (ICC: 0.82-0.98) and was lowest when transducer type varied (ICC: 0.47-0.71). Reliability was better from ROIs spanning a narrow range of depths compared with larger ranges. cMB measurements are more reliable than grayscale between different ultrasound systems and configurations. Measuring cMB could improve widespread implementation of quantitative ultrasound in assessments of skeletal muscle pathology.

Comparison of bulb syringe, pressurized pulsatile, and hydrosurgery debridement methods for removing bacteria from fracture implants

Surgical-site infection is a common form of noscomial infection that can occur in fractures following internal fixation. Treatment of these infections has traditionally included preserving stable implants via debridement and antibiotic administration while the fracture is healing. Recent evidence indicated that this algorithm results in less-than-optimal rates of fracture union and infection eradication.The premise for this study is that bacterial removal from fracture implants using the Versajet Hydrosurgery System (Smith & Nephew, Memphis, Tennessee) method is better compared with the bulb syringe and pressurized pulsatile lavage methods. Thirty-two stainless steel, 4-hole, nonlocking, 3.5-mm fracture plates were incubated with Staphylococus aureus and divided into 4 groups. Eight plates in each group underwent irrigation with 1 L of saline using a bulb syringe lavage, pressurized pulsatile lavage, or the Versajet Hydrosurgery System method. Eight plates underwent no irrigation method and served as a control group. The residual bacterial loads following irrigation were quantitatively cultured. Each of the experimental groups had significantly reduced levels of bacteria adherent to the plate following irrigation compared with the control group (P=.0002). Furthermore, the Versajet Hydrosurgery System was most the effective at bacterial removal, followed by the pressurized pulsatile and bulb syringe lavage techniques (P=.0002 to P=.0012, respectively).Novel approaches to eradicate bacteria from implants, such as hydrosurgery technology, while maintaining rigid stability of healing fracture, may improve clinical outcomes.

Angiogenesis imaging with vascular-constrained particles: the why and how

Angiogenesis is a keystone in the treatment of cancer and potentially many other diseases. In cancer, first-generation antiangiogenic therapeutic approaches have demonstrated survival benefit in subsets of patients, but their high cost and notable adverse side effect risk have fueled alternative development efforts to personalize patient selection and reduce off-target effects. In parallel, rapid advances in cost-effective genomic profiling and sensitive early detection of high-risk biomarkers for cancer, atherosclerosis, and other angiogenesis-related pathologies will challenge the medical imaging community to identify, characterize, and risk stratify patients early in the natural history of these disease processes. Conventional diagnostic imaging techniques were not intended for such sensitive and specific detection, which has led to the emergence of novel noninvasive biomedical imaging approaches. The overall intent of molecular imaging is to achieve greater quantitative characterization of pathologies based on microanatomical, biochemical, or functional assessments; in many approaches, the capacity to deliver effective therapy, e.g., antiangiogenic therapy, can be combined. Agents with both diagnostic and therapy attributes have acquired the moniker "theranostics." This review will explore biomedical imaging options being pursued to better segment and treat patients with angiogenesis-influenced disease using vascular-constrained contrast platform technologies.

Theragnostics for tumor and plaque angiogenesis with perfluorocarbon nanoemulsions

Molecular imaging agents are extending the potential of noninvasive medical diagnosis from basic gross anatomical descriptions to complicated phenotypic characterizations based upon the recognition of unique cell-surface biochemical signatures. Although originally the purview of nuclear medicine, "molecular imaging" is now studied in conjunction with all clinically relevant imaging modalities. Of the myriad of particles that have emerged as prospective candidates for clinical translation, perfluorocarbon nanoparticles offer great potential for combining targeted imaging with drug delivery, much like the "magic bullet" envisioned by Paul Ehrlich 100 years ago. Perfluorocarbon nanoparticles, once studied in Phase III clinical trials as blood substitutes, have found new life for molecular imaging and drug delivery. The particles have been adapted for use with all clinically relevant modalities and for targeted drug delivery. In particular, their intravascular constraint due to particle size provides a distinct advantage for angiogenesis imaging and antiangiogenesis therapy. As perfluorocarbon nanoparticles have recently entered Phase I clinical study, this review provides a timely focus on the development of this platform technology and its application for angiogenesis-related pathologies.

The use of implantable bone stimulators in nonunion treatment

Delayed or failure of bone healing in fracture, osteotomy, and arthrodesis patients continues to be a clinical dilemma. Electromagnetic stimulation is 1 modality demonstrated in many studies to aid bone healing; however, relatively few studies depict the use and complications associated with direct current implantable bone stimulators. Over a 9-year period, we studied a consecutive series of 120 adult patients who underwent implantation of a direct current bone stimulator. The goals of this study were to determine the time until healing, the presence of infection, and the need for additional nonunion surgery or salvage procedure following internal bone stimulator placement for nonunion treatment. Of the factors affecting the time until healing, tobacco smoking was a significant factor associated with increased time until healing. Tobacco smoking and duration of nonunion prior to implantable bone stimulator placement were both significant factors in the need for revision nonunion surgery or salvage procedure after implantable bone stimulator placement. Deep soft tissue infection or osteomyelitis was a significant factor predicting prolonged time to healing, subsequent infection following implantable bone stimulator placement, and the need for revision or salvage surgery. With the relative lack of complications directly attributable to electromagnetic implantable bone stimulators, their use may be an effective adjuvant to stable internal fixation and autogenous bone grafting in healing nonunions. However, the use of implantable bone stimulators in patients with nonunion prior to deep soft tissue infection or osteomyelitis exhibited an increased rate of postoperative infection in this study.

Real-time calculation of a limiting form of the Renyi entropy applied to detection of subtle changes in scattering architecture

Previously a new method for ultrasound signal characterization using entropy H(f) was reported, and it was demonstrated that in certain settings, further improvements in signal characterization could be obtained by generalizing to Renyi entropy-based signal characterization I(f)(r) with values of r near 2 (specifically r=1.99) [M. S. Hughes et al., J. Acoust. Soc. Am. 125, 3141-3145 (2009)]. It was speculated that further improvements in sensitivity might be realized at the limit r-->2. At that time, such investigation was not feasible due to excessive computational time required to calculate I(f)(r) near this limit. In this paper, an asymptotic expression for the limiting behavior of I(f)(r) as r-->2 is derived and used to present results analogous to those obtained with I(f)(1.99). Moreover, the limiting form I(f,infinity) is computable directly from the experimentally measured waveform f(t) by an algorithm that is suitable for real-time calculation and implementation.

Application of Renyi entropy for ultrasonic molecular imaging

Previous work has demonstrated that a signal receiver based on a limiting form of the Shannon entropy is, in certain settings, more sensitive to subtle changes in scattering architecture than conventional energy-based signal receivers [M. S. Hughes et al., J. Acoust. Soc. Am. 121, 3542-3557 (2007)]. In this paper new results are presented demonstrating further improvements in sensitivity using a signal receiver based on the Renyi entropy.

Post-traumatic catamenial sciatica

This article presents a unique case of posttraumatic extrapelvic endometriosis presenting as a gluteal mass causing cyclic sciatica. A 38-year-old woman presented with an enlarging right buttock mass over the previous 6 years. She also had symptoms of radicular pain referred to the right leg and foot with sitting and daily activity. Four years prior to noticing the mass, she sustained a gunshot wound through the lower abdomen while 5 months pregnant. Excisional biopsy of the gluteal mass revealed endometrioma. Sciatica is a common and painful disorder that is believed to have an incidence of 40% in the adult population. Sciatica is most often due to intraspinal pathology affecting the lumbar nerve roots. There are many recognized extraspinal etiologies for sciatica in the literature including aneurysms, sciatic hernia, abcess, neoplasm, trochanteric wire, piriformis syndrome, ischial fracture, a posteriorly flexed uterus, and even an intrauterine device following uterine perforation. Similarly, endometriosis is a gynecologic condition that represents a significant health problem for women of reproductive age as it occurs in up to 50% of premenopausal women and 71% to 87% in women with chronic pelvic pain. Although rare, endometriosis has a well known ability to migrate outside of the abdominal cavity and proliferate ectopically under the control of systemic estrogen.

Sensitive ultrasonic delineation of steroid treatment in living dystrophic mice with energy-based and entropy-based radio frequency signal processing

Duchenne muscular dystrophy is a severe wasting disease, involving replacement of necrotic muscle tissue by fibrous material and fatty infiltrates. One primary animal model of this human disease is the X chromosome-linked mdx strain of mice. The goals of the present work were to validate and quantify the capability of both energy and entropy metrics of radio-frequency ultrasonic backscatter to differentiate among normal, dystrophic, and steroid-treated skeletal muscle in the mdx model. Thirteen 12-month-old mice were blocked into three groups: 4 treated mdx-dystrophic that received daily subcutaneous steroid (prednisolone) treatment for 14 days, 4 positive-control mdx-dystrophic that received saline injections for 14 days, and 5 negative-control animals. Biceps muscle of each animal was imaged in vivo using a 40-MHz center frequency transducer in conjunction with a Vevo-660 ultrasound system. Radio-frequency data were acquired (1 GHz, 8 bits) corresponding to a sequence of transverse images, advancing the transducer from "shoulder" to "elbow" in 100-micron steps. Data were processed to generate both "integrated backscatter" (log energy), and "entropy" (information theoretic receiver, H(f)) representations. Analyses of the integrated-backscatter values delineated both treated-and untreated-mdx biceps from normal controls (p < 0.01). Complementary analyses of the entropy images differentiated the steroid-treated and positive-control mdx groups (p < 0.01). To our knowledge, this study represents the first reported use of quantitative ultrasonic characterization of skeletal muscle in mdx mice. Successful differentiation among dystrophic, steroid-treated, and normal tissues suggests the potential for local noninvasive monitoring of disease severity and therapeutic effects.

Sensitive ultrasonic detection of dystrophic skeletal muscle in patients with duchenne muscular dystrophy using an entropy-based signal receiver

The dystrophinopathies comprise a group of X-linked genetic diseases that feature dystrophin deficiency. Duchenne and Becker muscular dystrophy are characterized by progressive weakness and wasting of skeletal, smooth, and/or cardiac muscle. Duchenne muscular dystrophy (DMD) is the most severe dystrophinopathy, with an incidence of 1:3500 male births. Despite understanding the structural and genetic basis for DMD, the pathogenesis and clinical basis for more severe involvement in specific skeletal muscle groups and the heart are poorly understood. Current techniques, such as strength testing for monitoring progress of disease and therapy in DMD patients, are imprecise and physically demanding for test subjects. Ultrasound is well-suited to detect changes in structure and organization in muscle tissue in a manner that makes low demands on the patient. Therefore, we investigated the use of ultrasound to quantitatively phenotype the remodeling process in patients with DMD. Beam-formed radio-frequency (RF) data were acquired from the skeletal muscles of nine DMD and five normal subjects imaged with a clinical imaging system (HDI5000 w/7 MHz probe applied above left biceps muscle). From these data, images were reconstructed using B-mode (log of analytic signal magnitude) and information-theoretic receivers (H(f)-receiver). H(f) images obtained from dystrophic muscle contained extensive "mottled" regions (i.e., areas with heterogeneous image contrast) that were not readily apparent from the B-Mode images. The 2-D autocorrelation of DMD H(f) images have broader peaks than those of normal subjects, which is indicative of larger scatterer sizes, consistent with pathologic changes of fibers, edema and fatty infiltration. Comparison of the relative peak widths (full width measured at 60% maximum) of the autocorrelation of the DMD and normal H(f) images shows a quantitative difference between the two groups (p < 0.005, student two-tailed paired t-test). Consequently, these imaging techniques may prove useful for longitudinal monitoring of disease progression and therapy.

Properties of an entropy-based signal receiver with an application to ultrasonic molecular imaging

Qualitative and quantitative properties of the finite part, H(f), of the Shannon entropy of a continuous waveform f(t) in the continuum limit are derived in order to illuminate its use for waveform characterization. Simple upper and lower bounds on H(f), based on features of f(t), are defined. Quantitative criteria for a priori estimation of the average-case variation of H(f) and log E(f), where E(f) is the signal energy of f(t) are also derived. These provide relative sensitivity estimates that could be used to prospectively choose optimal imaging strategies in real-time ultrasonic imaging machines, where system bandwidth is often pushed to its limits. To demonstrate the utility of these sensitivity relations for this application, a study designed to assess the feasibility of identification of angiogenic neovasculature targeted with perfluorocarbon nanoparticles that specifically bind to alpha(v)beta3-integrin expression in tumors was performed. The outcome of this study agrees with the prospective sensitivity estimates that were used for the two receivers. Moreover, these data demonstrate the ability of entropy-based signal receivers when used in conjunction with targeted nanoparticles to elucidate the presence of alpha(v)beta3 integrins in primordial neovasculature, particularly in acoustically unfavorable environments.

Enhanced fracture and soft-tissue healing by means of anabolic dietary supplementation

BACKGROUND

Malnutrition is common in hospitalized injured patients. It contributes to delayed fracture-healing and increased morbidity. However, relatively little attention has been directed toward nutritional strategies for augmenting musculoskeletal recovery after a fracture. This animal study was designed to examine the effects of dietary protein intake and the role of conditionally essential amino acids in muscle and bone-healing after a fracture.

METHODS

One hundred adult male rats were used. Ten rats served as controls and received a 15% protein diet throughout the study. The remaining ninety rats received a 6% protein diet for five weeks to induce protein malnutrition. The rats underwent intramedullary nailing and closed midshaft fracture of one femur. After the fracture, they were separated into three isocaloric dietary groups. Group P6 received a diet with 6% protein; Group P15, a diet with 15% protein; and group P30, a diet with 30% protein with conditionally essential amino acids. At two, four, and six weeks after surgery, ten animals from each group were killed and the femora were evaluated with dual x-ray absorptiometry, histomorphometric assessment of callus, and torsional testing. The quadriceps muscles were analyzed for total mass, total protein content, and for mRNA expression of insulin-like growth factor-1 (IGF-1), IGF-2, IGF receptors, actin, myosin, and vascular endothelial growth factor (VEGF).

RESULTS

The P30 group demonstrated elevations in albumin, body mass, muscle mass, total protein content of muscle, and bone mineral density in the fracture callus compared with the P6 diet group at six weeks (p < 0.05). Molecular analysis of muscle revealed that IGF-1, IGF-2, IGF receptors, myosin, actin, and VEGF gene expression were significantly (p < 0.001) higher in the P6 group compared with the P30 group. Biomechanical testing of the femora, however, showed no significant differences.

CONCLUSIONS

Dietary supplementation with conditionally essential amino acids in malnourished animals had anabolic effects on bone mineralization, body mass, and muscle mass.

Nanomedicine opportunities for cardiovascular disease with perfluorocarbon nanoparticles

Nanomedicine promises to enhance the ability of clinicians to address some of the serious challenges responsible for cardiovascular mortality, morbidity and numerous societal consequences. Targeted imaging and therapy applications with perfluorocarbon nanoparticles are relevant to a broad spectrum of cardiovascular diseases, ranging from asymptomatic atherosclerotic disease to acute myocardial infarction or stroke. As illustrated in this article, perfluorocarbon nanoparticles offer new tools to recognize and characterize pathology, to identify and segment high-risk patients and to treat chronic and acute disease.

Characterization of digital waveforms using thermodynamic analogs: detection of contrast-targeted tissue in vivo

We describe characterization of backscatter from tumor tissue targeted with a nanoparticle-based ultrasound contrast agent in vivo using analogs of thermodynamic quantities. We apply these waveform characteristics to detection of tumor neovasculature in tumors implanted in athymic nude mice, which were imaged using a research ultrasound scanner over a 2-hour period after injection of alpha upsilon beta3-targeted perfluorocarbon nanoparticles. Images were constructed from backscattered ultrasound using two different approaches: fundamental B-mode imaging and a signal receiver based on a thermodynamic analog (H(C)). The study shows that the thermodynamic analog is capable of detecting differences in backscattered signals that are not apparent with the B-mode approach.

Acoustic activation of targeted liquid perfluorocarbon nanoparticles does not compromise endothelial integrity

Perfluorocarbon nanoparticles consisting essentially of liquid perfluoro-octyl bromide (PFOB) core surrounded by a lipid monolayer can serve as highly specific site-targeted contrast and therapeutic agents after binding to cellular biomarkers. Based on previous findings that ultrasound applied at 2 MHz and 1.9 mechanical index (MI) for a 5-min duration dramatically enhances the cellular interaction of targeted PFOB nanoparticles with melanoma cells in vitro without inducing apoptosis or other harmful effects to cells that are targeted, we sought to define mechanisms of interaction and the safety profile of ultrasound used in conjunction with liquid perfluorocarbon nanoparticles for targeted drug delivery, as compared with conventional microbubble ultrasound contrast agents under identical insonification conditions. Cell-culture inserts were used to grow a confluent monolayer of human umbilical vein endothelial cells. Definity in conjunction with continuous wave ultrasound (2.25 MHz for 1 and 5 min) increased the permeability of monolayer by four to six times above the normal, decreased transendothelial electrical resistance (a sign of reduced membrane integrity), and decreased cell viability by approximately 50%. Histological evaluation demonstrated extensive disruptions of cell monolayers. Nanoparticles (both nontargeted and targeted) elicited no changes in these different measures under similar insonification conditions and did not disrupt cell monolayers. We hypothesize that ultrasound facilitates drug transport from the perfluorocarbon nanoparticles not by cavitation-induced effects on cell membrane but rather by direct interaction with the nanoparticles that stimulate lipid exchange and drug delivery.

Obstructive sleep apnoea syndrome in morbidly obese children with tibia vara

Morbid obesity and its association with obstructive sleep apnoea syndrome have been increasingly recognised in children. Orthopaedic surgeons are often the primary medical contact for older children with tibia vara, which has long been associated with obesity, but are unfamiliar with the evaluation and treatment of sleep apnoea in children. We reviewed all children with tibia vara treated surgically at one of our institutions over a period of five years. Thirty-seven patients were identified; 18 were nine years of age or older and 13 of these (72%) had morbid obesity and a history of snoring. Eleven children were diagnosed as having sleep apnoea on polysomnography. The incidence of this syndrome in the 18 children aged nine years or older with tibia vara, was 61%. All these patients required pre-operative non-invasive positive-pressure ventilation; tonsillectomy and adenoidectomy were necessary in five (45%). No peri-operative complications related to the airway occurred. There is a high incidence of sleep apnoea in morbidly obese patients with tibia vara. These patients should be screened for snoring and, if present, should be further evaluated for sleep apnoea before corrective surgery is undertaken.

Sonic activation of molecularly-targeted nanoparticles accelerates transmembrane lipid delivery to cancer cells through contact-mediated mechanisms: implications for enhanced local drug delivery

Liquid perfluorocarbon nanoparticles serve as sensitive and specific targeted contrast and drug delivery vehicles by binding to specific cell surface markers. We hypothesized that application of acoustic energy at diagnostic power levels could promote nanoparticle-associated drug delivery by stimulating increased interaction between the nanoparticle's lipid layer and the targeted cell's plasma membrane. Ultrasound (mechanical index = 1.9) applied with a conventional ultrasound imaging system to nanoparticles targeted to alpha(v)beta3-integrins on C32 melanoma cancer cells in vitro produced no untoward effects. Within 5 min, lipid delivery from nanoparticles into cell cytoplasm was dramatically augmented. We also demonstrate the operation of a potential physical mechanism for this effect, the acoustic radiation force on the nanoparticles, which may contribute to the enhanced lipid delivery. Accordingly, we propose that local delivery of lipophilic substances (e.g., drugs) from targeted nanoparticles directly into cell cytoplasm can be augmented rapidly and safely with conventional ultrasound imaging devices through nondestructive mechanisms.

Characterization of digital waveforms using thermodynamic analogs: applications to detection of materials defects

We describe characterization of digital signals using analogs of thermodynamic quantities: the topological entropy, Shannon entropy, thermodynamic energy, partition function, specific heat at constant volume, and an idealized version of Shannon entropy in the limit of digitizing with infinite dynamic range and sampling rate. We show that analysis based on these quantities is capable of detecting differences between digital signals that are undetectable by conventional methods of characterization based on peak-to-peak amplitude or signal energy. We report the results of applying thermodynamic quantities to a problem from nondestructive materials evaluation: detection of foreign objects (FO) embedded near the surface of thin graphite/epoxy laminates using backscattered waveforms obtained by C-scanning the laminate. The characterization problem was to distinguish waveforms acquired from the region containing the FO from those acquired outside. In all cases the thermodynamic analogs exhibit significant increases (up to 20-fold) in contrast and for certain types of FO materials permit detection when energy or amplitude methods fail altogether.

Molecular analyses of mycobacteria other than the M. tuberculosis complex isolated from Northern Ireland cattle

Mycobacteria other than the Mycobacterium tuberculosis complex (MOTT), isolated from Northern Ireland cattle, were identified by PCR amplification of the 16S rRNA gene, and subsequent reverse cross blot hybridisation and sequence analyses. Elucidation of the MOTT species was to facilitate specificity testing of new and existing diagnostic test reagents for bovine tuberculosis. The presence of the genes for potential diagnostic antigens: MPB70, MPB64, ESAT-6 and CFP-10 in the isolated MOTT species was investigated. Molecular analyses of cultured isolates from bovine lymph node specimens of 48 cattle identified a wide variety of mycobacterial species including Mycobacterium nonchromogenicum, Mycobacterium malmoense, Mycobacterium bohemicum, Mycobacterium paratuberculosis, Mycobacterium avium, Mycobacterium kansasii, Mycobacterium holsaticum, Mycobacterium palustre, Mycobacterium sp. IWGMT 90210, Mycobacterium sp. LIV-2129, a potentially novel mycobacterial species (EMBL/GenBank/DDBJ Accession Number AJ617495) and Rhodococcus equi. Apart from M. kansasii, the results of traditional (standard phenotypic and biochemical) and molecular identification methods did not correlate well, with traditional methods identifying fewer species. Most of the species identified were either recognised pathogenic or potential pathogenic species. The genes for ESAT-6, CFP-10 and, unusually, MPB64 were detected in M. kansasii only. The MPB70 gene was not detected in any of the species. This study supported restricted species distribution of these genes as well as identifying a different range of MOTT species that could be included in specificity testing of new diagnostic reagents for bovine tuberculosis.

Acoustic characterization in whole blood and plasma of site-targeted nanoparticle ultrasound contrast agent for molecular imaging

The ability to enhance specific molecular markers of pathology with ultrasound has been previously demonstrated by our group employing a nanoparticle contrast agent [Lanza et al., Invest. Radiol. 35, 227-234 (2000); Ultrasound Med. Biol. 23, 863-870 (1997)]. One of the advantages of this agent is very low echogenicity in the blood pool that allows increased contrast between the blood pool and the bound, site-targeted agent. We measured acoustic backscatter and attenuation coefficient as a function of the contrast agent concentration, ambient pressure, peak acoustic pressure, and as an effect of duty cycle and wave form shape. Measurements were performed while the nanoparticles were suspended in either whole porcine blood or plasma. The nanoparticles were only detectable when insonified within plasma devoid of red blood cells and were shown to exhibit backscatter levels more than 30 dB below the backscatter from whole blood. Attenuation of nanoparticles in whole porcine blood was not measurably different from that of whole blood alone over a range of concentrations up to eight times the maximum in vivo dose. The resulting data provide upper bounds on blood pool attenuation coefficient and backscatter and will be needed to more precisely define levels of molecular contrast enhancement that may be obtained in vivo.