Bone turnover markers correlate with implant fixation in a rat model using LPS-doped particles to induced implant loosening

Revision surgery for particle-induced implant loosening in total joint replacement is expected to increase dramatically over the next few decades. This study was designed to investigate if local tissue and serum markers of bone remodeling reflect implant fixation following administration of lipopolysaccharide (LPS)-doped polyethylene (PE) particles in a rat model. Twenty-four rats received bilateral implantation of intramedullary titanium rods in the distal femur, followed by weekly bilateral intra-articular injection of either LPS-doped PE particles (n = 12) or vehicle that contained no particles (n = 12) for 12 weeks. The group in which the particles were injected had increased serum C-terminal telopeptide of type I collagen (CTX-I), decreased serum osteocalcin (OC), increased peri-implant eroded surface, decreased peri-implant bone volume, and decreased mechanical pull-out strength compared to the controls. Implant fixation strength was positively correlated with peri-implant bone volume and serum OC and inversely correlated with serum CTX-I, while energy to yield was positively correlated with serum OC and inversely correlated with the number of tartrate-resistant acid phosphatase positive cells at the interface and the amount of peri-implant eroded surface. There was no effect on trabecular bone volume at a remote site. Thus, the particle-induced impaired fixation in this rat model was directly associated with local and serum markers of elevated bone resorption and depressed bone formation, supporting the rationale of exploring both anticatabolic and anabolic strategies to treat and prevent particle-related implant osteolysis and loosening, and indicating that serum markers may prove useful in tracking implant fixation.     

Size-controlled insulin-secreting cell clusters

The search for an effective cure for type I diabetes from the transplantation of encapsulated pancreatic β-cell clusters has so far produced sub-optimal clinical outcomes. Previous efforts have not controlled the size of transplanted clusters, a parameter implicated in affecting long-term viability and the secretion of therapeutically sufficient insulin. Here we demonstrate a method based on covalent attachment of patterned laminin for fabricating uniformly size-controlled insulin-secreting cell clusters. We show that cluster size within the range 40–120 μm in diameter affects a variety of therapeutically relevant cellular responses including insulin expression, content and secretion. Our studies elucidate two size-dependent phenomena: (1) as the cluster size increases from 40 μm to 60 μm, glucose stimulation results in a greater amount of insulin produced per cell; and (2) as the cluster size increases beyond 60 μm, sustained glucose stimulation results in a greater amount of insulin secreted per cell. Our study describes a method for producing uniformly sized insulin-secreting cell clusters, and since larger cluster sizes risk nutrient availability limitations, our data suggest that 100–120 μm clusters may provide optimal viability and efficacy for encapsulated β-cell transplants as a treatment for type I diabetes and that further in vivo evaluation is warranted.     

A multidisciplinary approach to the development of a cervical spine clearance protocol: process,rationale, and initial results

Background/Purpose: Assessment of potential spine injuries is inconsistent and controversial. Subsequent morbidity includes prolonged immobilization and missed injuries. To address these issues, a multidisciplinary team was organized to design a cervical spine management/clearance pathway. The process, algorithm, and initial results are described. Methods: Team members consisted of pediatric surgeons, orthopedic surgeons, neurosurgeons, emergency room physicians, and trauma nurse practitioners. Nationwide standards, guidelines, and experiences across disciplines were reviewed, and a consensus pathway evolved for cervical spine clearance in children 8 years and younger. A short-term retrospective review (5 months) was performed to assess initial performance. Time required for clearance, number and type of imaging studies, and number of missed injuries were compared between a group of patients before (n = 71) and after (n = 56) the implementation of the pathway. Results: Strict guidelines for cervical spine immobilization and clearance criteria were defined. After implementation of this pathway, time required for cervical clearance in nonintubated children decreased (before, 12.3 [plusmn] 1.5 v after, 7.5 [plusmn] 0.9 hours; P = .014). A clear trend toward earlier clearance in intubated patients existed (before [n = 6], 40.0 [plusmn] 16.8 v after [n = 6], 19.4 [plusmn] 8.1 hours; P = .10); there need to be larger numbers to determine statistical significance. The 2 study groups were similar in age; mechanism of injury; Glasgow coma scale score; and number of plain x-rays, computed tomography scans, and magnetic resonance imaging studies obtained. Neither group had missed injuries. Conclusions: standards for cervical spine immobilization, assessment, and clearance. Implementation of such guidelines decreased time for cervical spine clearance, and ongoing analysis of sensitivity is encouraging. J Pediatr Surg 38:358-362.     

Externalizing and Internalizing Subtypes of Posttraumatic Psychopathology and Anger Expression

Subtypes of posttraumatic psychopathology were replicated and extended in 254 female veterans with posttraumatic stress disorder (PTSD). Cluster analyses on Minnesota Multiphasic Personality Inventory‐2 and Personality Psychopathology Five scales (Harkness, McNulty, & Ben‐Porath, 1995 ) yielded internalizing and externalizing psychopathology dimensions, with a third low psychopathology group (simple PTSD). Externalizers were higher than the internalizers and the simple PTSD groups on the antisocial, substance, and aggression scales; internalizers were higher on depression and anxiety scales. Further validation included an independent measure of psychopathology to examine anger (Buss‐Durkee Hostility Inventory, [BDHI]; Buss & Durkee, 1957 ). Externalizers were higher on extreme behavioral anger scales (assault and verbal hostility); and externalizers and internalizers were higher than the simple PTSD subjects on other anger scales. Positive correlations between the BDHI scales and the PTSD symptom of “irritability and anger outbursts” were found across scales in the total sample (range: r = .19–.36), on the assault scale in externalizers (r = .59), and the verbal hostility scale in both internalizers (r = .30) and simple PTSD (r = .37) groups, suggesting the broad utility of the symptom in the diagnosis. The results demonstrate the generalizability of the internalizing/externalizing typology to the female veteran population and highlight clinically relevant distinctions in anger expression within PTSD.     

Cervical radicular pain caused by herpes simplex virus-type 1 infection: a case report

A case of a 16-year-old with herpes simplex virus type-1 infection with radicular arm pain is reported. The clinical implications of the case are discussed.     

Gene expression of growth differentiation factors in the developing periodontium of rat molars

Growth and differentiation factors (GDF) 5, 6, and 7 are known to play roles in tendon and ligament formation, and are therefore probably involved in the formation of periodontal ligament. In this study, we sought to determine temporal and spatial expression of GDF-5, -6, and -7 mRNA in developing periodontal tissue of rat molars using in situ hybridization. GDF gene expression in the periodontal ligament was first detected in cells associated with the initial process of periodontal ligament fiber bundle formation. Gene signals were also detected in cells located along the alveolar bone and cementum surfaces, the insertion sites of periodontal ligaments, during the course of root formation. GDF expression in these cells were down-regulated after completion of root formation. Our results appeared to suggest the involvement of GDF-5, -6, and -7 in the formation of the dental attachment apparatus.     

Abdominal lymphoma with abscess and thoracic perforation: en-bloc resection

The authors compare a rare case of acute onset Gastric Lymphoma with that present in the literature. The patient, a white 67 year-old man, was admitted to hospital in severe general condition. On CT scan an opacity of the pleura and a subtotal collapse of the left lung associated with a mass infiltrating the diaphragm, the gastric fundus and pancreas were seen. After 48 hours from the admission an operation was performed. The abdominal mass infiltrating the stomach, the spleen and the left thorax was resected en-bloc by laparotomy. A Boulau drainage was inserted. The histology showed an high malignant, diffused, big cell lymphoma. The patient was discharged 23 days later after a regular postoperative course. Surgery can be necessary, sometime curative in gastric lymphomas while long term result and quality of life could be improved by chemotherapy.