Systemic inhibition or global deletion of CaMKK2 protects against post-traumatic osteoarthritis.

OBJECTIVE: To investigate the role of Ca2+/calmodulin-dependent protein kinase 2 (CaMKK2) in post-traumatic osteoarthritis (PTOA). METHODS: Destabilization of the medial meniscus (DMM) or sham surgeries were performed on 10-week-old male wild-type (WT) and Camkk2-/- mice. Half of the DMM-WT mice and all other cohorts (n = 6/group) received tri-weekly intraperitoneal (i.p.) injections of saline whereas the remaining DMM-WT mice (n = 6/group) received i.p. injections of the CaMKK2 inhibitor STO-609 (0.033 mg/kg body weight) thrice a week. Study was terminated at 8- or 12-weeks post-surgery, and knee joints processed for microcomputed tomography imaging followed by histology and immunohistochemistry. Primary articular chondrocytes were isolated from knee joints of 4-6-day-old WT and Camkk2-/- mice, and treated with 10 ng/ml interleukin-1ß (IL)-1ß for 24 or 48 h to investigate gene and protein expression. RESULTS: CaMKK2 levels and activity became elevated in articular chondrocytes following IL-1ß treatment or DMM surgery. Inhibition or absence of CaMKK2 protected against DMM-associated destruction of the cartilage, subchondral bone alterations and synovial inflammation. When challenged with IL-1ß, chondrocytes lacking CaMKK2 displayed attenuated inflammation, cartilage catabolism, and resistance to suppression of matrix synthesis. IL-1ß-treated CaMKK2-null chondrocytes displayed decreased IL-6 production, activation of signal transducer and activator of transcription 3 (Stat3) and matrix metalloproteinase 13 (MMP13), indicating a potential mechanism for the regulation of inflammatory responses in chondrocytes by CaMKK2. CONCLUSIONS: Our findings reveal a novel function for CaMKK2 in chondrocytes and highlight the potential for its inhibition as an innovative therapeutic strategy in the prevention of PTOA.

Suppression of cancer-associated bone loss through dynamic mechanical loading.

Patients afflicted with or being treated for cancer constitute a distinct and alarming subpopulation who exhibit elevated fracture risk and heightened susceptibility to developing secondary osteoporosis. Cancer cells uncouple the regulatory processes central for the adequate regulation of musculoskeletal tissue. Systemically taxing treatments to target tumors or disrupt the molecular elements driving tumor growth place considerable strain on recovery efforts. Skeletal tissue is inherently sensitive to mechanical forces, therefore attention to exercise and mechanical loading as non-pharmacological means to preserve bone during treatment and in post-treatment rehabilitative efforts have been topics of recent focus. This review discusses the dysregulation that cancers and the ensuing metabolic dysfunction that confer adverse effects on musculoskeletal tissues. Additionally, we describe foundational mechanotransduction pathways and the mechanisms by which they influence both musculoskeletal and cancerous cells. Functional and biological implications of mechanical loading at the tissue and cellular levels will be discussed, highlighting the current understanding in the field. Herein, in vitro, translational, and clinical data are summarized to consider the positive impact of exercise and low magnitude mechanical loading on tumor-bearing skeletal tissue.

Progressive skeletal benefits of physical activity when young as assessed at the midshaft humerus in male baseball players.

Physical activity benefits the skeleton, but there is contrasting evidence regarding whether benefits differ at different stages of growth. The current study demonstrates that physical activity should be encouraged at the earliest age possible and be continued into early adulthood to gain most skeletal benefits. INTRODUCTION: The current study explored physical activity-induced bone adaptation at different stages of somatic maturity by comparing side-to-side differences in midshaft humerus properties between male throwing athletes and controls. Throwers present an internally controlled model, while inclusion of control subjects removes normal arm dominance influences. METHODS: Throwing athletes (n = 90) and controls (n = 51) were categorized into maturity groups (pre, peri, post-early, post-mid, and post-late) based on estimated years from peak height velocity (<-2, -2 to 2, 2 to 4, 4 to 10, and >10 years). Side-to-side percent differences in midshaft humerus cortical volumetric bone mineral density (Ct.vBMD) and bone mineral content (Ct.BMC); total (Tt.Ar), medullary (Me.Ar), and cortical (Ct.Ar) areas; average cortical thickness (Ct.Th); and polar Strength Strain Index (SSIP) were assessed. RESULTS: Significant interactions between physical activity and maturity on side-to-side differences in Ct.BMC, Tt.Ar, Ct.Ar, Me.Ar, Ct.Th, and SSIP resulted from the following: (1) greater throwing-to-nonthrowing arm differences than dominant-to-nondominant arm differences in controls (all p < 0.05) and (2) throwing-to-nonthrowing arm differences in throwers being progressively greater across maturity groups (all p < 0.05). Regional analyses revealed greatest adaptation in medial and lateral sectors, particularly in the three post-maturity groups. Years throwing predicted 59% of the variance of the variance in throwing-to-nonthrowing arm difference in SSIP (p < 0.001). CONCLUSION: These data suggest that physical activity has skeletal benefits beginning prior to and continuing beyond somatic maturation and that a longer duration of exposure to physical activity has cumulative skeletal benefits. Thus, physical activity should be encouraged at the earliest age possible and be continued into early adulthood to optimize skeletal benefits.

Microvascular coupling devices: neglected resource with a short learning curve.

Microvascular couplers have a record of efficiency and efficacy. They have been used in anastomoses in the head and neck in Sunderland since November 2013, where we have investigated the time taken for anastomosis, patency, and cost. We also completed a national survey of the use of couplers in the United Kingdom, in which we recorded the time of anastomosis. The mean (range) time was 4minutes (2minutes 40seconds - 4minutes 10seconds). One flap partially failed. This shows that couplers can save time, they have successful outcomes, and the technique is quick and easy to learn.

The influence of geography on uptake of plastic surgery services - analysis based on bilateral breast reduction data.

The hub-and-spoke model was introduced in the National Health Service (NHS) with the goal of providing equitable access to health care for all. This study uses bilateral breast reduction (BBR) surgery to assess the success of this model in delivering equity of access for plastic surgery within a publicly funded health-care system. This study also assessed the effect of socioeconomic deprivation on patients seeking BBR. The hospital records were used to identify all patients who underwent BBR at the St. John's Hospital between 1996 and 2005 (N=1081). Patients living outside the catchment area were excluded. Realistic travel distances and times to the hospital and clinics were calculated using patients' postcodes and geographic information systems (GIS) network analysis. Carstairs deprivation scores were obtained for the residential postcode of each patient. The main findings of this study are (1) accessibility to a plastic surgery clinic is an important factor in determining whether an eligible female patient undergoes BBR and (2) most deprived parts of the catchment area accounted for a significantly greater proportion of patients.

Thoracoscopic-assisted placement of azygos vein central venous catheter in a child.

Loss of central venous access in intestinal failure patients is a potentially fatal complication, and an indication for intestinal transplantation. Thrombosis of the superior vena cava (SVC) has historically been considered a contraindication to small bowel transplantation; however, unconventional central venous access can facilitate survival and eventual transplant procedure in patients with end-stage central venous access. We describe a technique for azygos vein central catheter insertion utilizing thoracoscopic guidance in a 14-year-old girl with thrombosis of the SVC and chronic idiopathic pseudo-obstruction syndrome awaiting multivisceral transplantation. The technique is simplified by utilizing carbon dioxide (CO(2)) insufflation of the thoracic cavity to collapse the lung instead of double-lumen endotracheal tube placement, and no postoperative chest tube drainage of the pleural space is required. Thoracoscopic-assisted central access can also be used in children requiring chronic hemodialysis with limited venous sites due to thrombosis or small size of vessels.

Automated cardiac auscultation for detection of pathologic heart murmurs.

Experienced cardiologists can usually recognize pathologic heart murmurs with high sensitivity and specificity, although nonspecialists with less clinical experience may have more difficulty. Harsh, pansystolic murmurs of intensity grade > or = 3 at the left upper sternal border (LUSB) are likely to be associated with pathology. In this study, we designed a system for automatically detecting systolic murmurs due to a variety of conditions and examined the correlation between relative murmur intensity and likelihood of pathology. Cardiac auscultatory examinations of 194 children and young adults were recorded, digitized, and stored along with corresponding echocardiographic diagnoses, and automated spectral analysis using continuous wavelet transforms was performed. Patients without heart disease and either no murmur or an innocent murmur (n = 95) were compared to patients with a variety of cardiac diagnoses and a pathologic systolic murmur present at the LUSB (n = 99). The sensitivity and specificity of the automated system for detecting pathologic murmurs with intensity grade > or = 2 were both 96%, and for grade > or = 3 murmurs they were 100%. Automated cardiac auscultation and interpretation may be useful as a diagnostic aid to support clinical decision making.

Proximal trisomy of 1q mosaicism in a girl with hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome and multiple congenital anomalies.

We report an African American female who is mosaic for partial trisomy of 1q due to a direct duplication of 1q12 to 1q25. The child has hypertrophic cardiomyopathy with Wolff-Parkinson-White syndrome. The physical features include micrognathia, cleft palate, low set ears, posteriorly placed thumbs, and syndactyly of the second and third toes of both feet. Other abnormalities include intestinal malrotation, scoliosis, mental retardation, cerebral palsy, and hydrocephalus. There was also a selective deficiency of antibody responses to polysaccharide antigens. Proximal duplication of chromosome 1q is rare and has not been previously associated with hypertrophic cardiomyopathy. Most known gene disorders related to hypertrophic cardiomyopathy are autosomal dominant missense mutations in sarcomeric protein genes; however, none of the sarcomeric genes previously linked to hypertrophic cardiomyopathy are in this region. This finding thus highlights the possibility of additional genetic mechanisms for hypertrophic cardiomyopathy.

Cardiac auscultatory recording database: delivering heart sounds through the Internet.

The clinical skill of cardiac auscultation, while known to be sensitive, specific, and inexpensive in screening for cardiac disease among children, has recently been shown to be deficient among residents in training. This decline in clinical skill is partly due to the difficulty in teaching auscultation. Standardization, depth, and breadth of experience has been difficult to reproduce for students due to time constraints and the impracticality of examining large numbers of patients with cardiac pathology. We have developed a web-based multimedia platform that delivers complete heart sound recordings from over 800 different patients seen at the Johns Hopkins Outpatient Pediatric Cardiology Clinic. The database represents more than twenty significant cardiac lesions as well as normal and innocent murmurs. Each patient record is complete with a gold standard echo for diagnostic confirmation and a gold standard auscultatory assessment provided by a pediatric cardiology attending.

Comparison of two antibiotic regimens in the treatment of perforated appendicitis in pediatric patients.

BACKGROUND AND PURPOSE: An increased incidence of post-surgical infectious complications in children admitted with a diagnosis of perforated appendicitis led to development of a disease-specific antibiogram and modification of our post-operative antibiotic regimen. METHODS: A historical control group comprised of 32 pediatric patients receiving ampicillin, gentamicin, and clindamycin (group AGC) was compared to a cohort of 32 children receiving ticarcillin/clavulanate plus gentamicin (group TG). The surgical procedure, peri-operative management, and inclusion, exclusion and discharge criteria were the same for each group. Outcome measures including length of stay, time to defervesce, incidence of infectious complications, and clinical failures to the antibiotic regimen were compared. RESULTS: The groups were similar with respect to gender, age, weight, surgical time, pre-operative leukocytes, and number of intra-operative bacterial isolates cultured per patient. Length of stay was 10.1 days in group TG and 12.5 days for group AGC (p = 0.0197). The number of clinical failures was reduced from 9 (28.1%) to 2 (6.3%) in group TG (p = 0.02). The time to defervesce was decreased by 1.4 days, and the number of infectious complications was reduced to 2.5-fold in group TG patients. CONCLUSIONS: Ticarcillin/clavulanate plus gentamicin was clinically more effective than ampicillin, gentamicin, and clindamycin combination therapy in the management of perforated appendicitis in our pediatric population.

Antibody-mediated red blood cell agglutination resulting in spontaneous echocardiographic contrast.

Spontaneous echocardiographic contrast is well reported in states of low flow and low shear stress, and the primary blood component involved has been reported as red blood cells via rouleaux formation. This report describes the occurrence of spontaneous echocardiographic contrast from a unique mechanism of IgM-mediated red blood cell agglutination and describes the clinical sequelae.

Comparison of laparoscopic and open splenectomy in children with hematologic disorders.

OBJECTIVE: To compare laparoscopic and traditional open splenectomy in children with nonmalignant hematologic disorders. STUDY DESIGN: Retrospective review of 36 consecutive nonrandomized splenectomies (16 laparoscopic and 20 open) performed for hematologic disorders at a single pediatric institution during the past 3 years. The two-sided Mann-Whitney U test for non-parametric variables was used for statistical analysis. RESULTS: An open procedure was performed on 20 patients (mean age, 9.7 years), five of whom had a concomitant cholecystectomy. A laparoscopic splenectomy was performed on 16 children (mean age, 10.3 years), seven of whom had a concomitant cholecystectomy. The mean anesthesia and operative times were longer in the laparoscopic than in the open group (p < 0.001). However, the mean number of hours of postoperative analgesia was less in the laparoscopic group (p < 0.005). Patients who had laparoscopic splenectomy were also discharged home earlier (p < 0.01) and resumed a regular diet sooner. Mean operating room charges were higher in the laparoscopic group (p < 0.001), but total hospitalization costs were not significantly different. Postoperative complication rates were similar. The hematologic response was comparable. CONCLUSIONS: laparoscopic splenectomy is feasible and safe in children with hematologic disorders. Although it currently requires more operative time than the open approach, it is superior with regard to duration of postoperative analgesia, duration of hospital stay, and recovery of bowel function.

Regulation of the rat cardiac troponin I gene by the transcription factor GATA-4.

Troponin I is a thin-filament contractile protein expressed in striated muscle. There are three known troponin I genes which are expressed in a muscle-fibre-type-specific manner in mature animals. Although the slow skeletal troponin I isoform is expressed in fetal and neonatal heart, the cardiac isoform is restricted in its expression to the myocardium at all developmental stages. To study the regulation of this cardiac-specific and developmentally regulated gene in vitro, the rat cardiac troponin I gene was cloned. Transient transfection assays were performed with troponin I-luciferase fusion plasmids to characterize the regulatory regions of the gene. Proximal regions of the upstream sequence were sufficient to support high levels of expression of the reporter gene in cardiocytes and relatively low levels in other cell types. The highest luciferase activity in the cardiocytes was noted with a plasmid that included the region spanning -896 to +45 of the troponin I genomic sequence. Co-transfection of GATA-4, a recently identified cardiac transcription factor, with troponin I-luciferase constructs permitted high levels of luciferase expression in non-cardiac cells. Electrophoretic mobility-shift assays demonstrated specific binding of GATA-4 to oligonucleotides representative of multiple sites of the troponin I sequence. Mutation of a proximal GATA-4 DNA-binding site decreased transcriptional activation in transfected cardiocytes. These results indicate that the proximal cardiac troponin I sequence is sufficient to support high levels of cardiac-specific gene expression and that the GATA-4 transcription factor regulates troponin I-luciferase expression in vitro.

Central venous catheters revisited--infection rates and an assessment of the new Fibrin Analysing System brush.

Sixty-one consecutive patients in the Intensive Care Unit requiring central venous lines (CVC) for five or more days were randomized to receive either a standard triple lumen CVC (STD/CVC) or a silver sulphadiazine and chlorhexidine impregnated CVC (SSD/CVC). Data from the 54 patients who completed the trial show a reduced infection rate (positive tip culture) in the SSD/CVC group (4 out of 28) compared to the STD/CVC group (10 out of 26) (P < 0.05). In addition, the new Fibrin Analysing System (FAS) brush was evaluated and used to determine the presence of infection in all the CVCs (STD/CVC and SSD/CVC combined, n = 54) at day 3 (i.e. early warning of CVC colonization/infection) and at the time of removal of the CVC. The FAS brush was able to detect an infected CVC on only one occasion on day 3 out of the 14 CVC tips which were later found to be colonized/infected at the time of removal. The sensitivity of the FAS brush in detecting colonized/infected CVCs at the time of CVC removal compared with CVC tip culture was 21% with a specificity of 100%. These findings would currently not support the routine use of the FAS brush in determining CVC infection/colonization.

Laparoscopic Nissen fundoplication in the infant.

Twenty-five children weighing less than 8 kg underwent laparoscopic Nissen fundoplication for treatment of refractory gastroesophageal reflux (GER) between January 1993 and April 1995. Mean patient age was 6 months and weight was 5.1 kg. Mean operative time was 114 min, including gastrostomy in 20 patients. Nineteen patients are alive without evidence of GER with a mean follow-up of 359 days. Perioperative complications were unusual and mild. There were 6 late deaths due to progression of underlying disease and not attributable to the procedure. Laparoscopic Nissen fundoplication provides effective antireflux protection to very small children with acceptable morbidity and mortality through short-term follow-up.

Laparoscopic splenectomy in childhood hematologic disorders.

Laparoscopic splenectomy is a new technique that is being utilized in patients with a variety of mostly hematologic disorders. Its application in children has not been extensively documented. Between January 1994 and February 1995, 11 children less than 15 years of age underwent elective laparoscopic splenectomy. Data collected from this treatment group were compared to that from the ten most recent open splenectomy patients with comparable hematologic disorders. All procedures in both groups were successful in relief of symptoms, increase in platelet count, and/or increase in hematocrit. Operative times averaged 147 mm in the laparoscopic group, compared to 112 mm in the open group. Estimated blood loss was 32 ml in the laparoscopic group and 86 ml in the open group. Days to laparoscopic patient discharge were 3.6, compared to 5.3 days in the open group. There were no wound complications or need for perioperative platelet transfusions in the laparoscopic patients. Patient response has been uniformly positive in the laparoscopic group. Reusable access trocars are utilized for two of the four working ports. Stapling devices and special tissue morselizers are not required. There are no additional operating room or surgeons fees incurred in the laparoscopic procedures. This series demonstrates that laparoscopic splenectomy is a safe, cost-efficient alternative to open splenectomy in children with a variety of hematologic disorders.

Percutaneous dilational tracheostomy--a clinical study evaluating two systems.

Percutaneous dilational tracheostomy (PDT), first described in the 1950s, has become a common bedside technique in the Intensive Care Unit (ICU). This study compares the early complications associated with the use of the Ciaglia PDT (Cook Critical Care, Bloomington, USA) technique, with the newly available Portex PDT technique (Portex Ltd., UK). The Ciaglia technique was adopted in this ICU in July 1994 and twenty-nine patients had a tracheostomy using this set until January 1995. Complications during the procedure were collected prospectively. When the Portex PDT set became available in January 1995, it was decided to assess the complication rate of this technique and compare them to the previously-collected data using the Ciaglia PDT set. Twenty-five patients have had a tracheostomy using the Portex PDT set. There has been no mortality associated with either PDT set. Bleeding requiring intervention occurred in two patients in the Ciaglia group and three patients in the Portex Group. All these patients had a bleeding diathesis. Loss of airway control occurred on one occasion in the Ciaglia group due to premature removal of the endotracheal tube. The first routine tracheostomy tube change at day 7 was complicated in four cases in the Ciaglia group. One infected stoma was noted in the Ciaglia group at day 7. Both techniques result in rapid, safe placement of a tracheostomy tube in critically ill patients in the ICU, obviating the need for surgical referral and transport to the operating room.