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1.
Int J Sports Med ; 37(1): 36-42, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26509369

ABSTRACT

The purpose of the current study was to determine if the application of platelet-rich fibrin matrix could improve regeneration of the tendon-bone insertion site in a rat rotator cuff repair model. 25 Lewis syngeneic rats underwent bilateral tenotomy and repair of the supraspinatus tendon. 10 separate rats were used for PRFM harvest. All left (control) shoulders underwent transosseous rotator cuff repair, while all right (treatment) shoulders were repaired similarly with PRFM augmentation. 9 rats were sacrificed at 2-weeks and ten at 4-weeks for biomechanical testing. 3 separate rats were sacrificed at 2-weeks and 4-weeks each for histologic analysis of the insertion site. At 2 weeks, the experimental group repairs were significantly stronger in ultimate load to failure (P=0.01), stress (P=0.03), and stiffness (P=0.03). Differences in biomechanical testing were not found between the groups at 4 weeks. Histological analysis revealed less collagen organization and cartilage formation at the insertion site in the experimental group. Semiquantitative histologic analysis confirmed our qualitative assessment of the specimens. PRFM does not recapitulate the native enthesis, but rather induces an exuberant and disordered healing response that is characterized by fibrovascular scar tissue.


Subject(s)
Fibrin/pharmacology , Platelet-Rich Plasma , Rotator Cuff Injuries , Wound Healing/drug effects , Animals , Biomechanical Phenomena , Collagen/metabolism , Male , Models, Animal , Rats, Inbred Lew , Rotator Cuff/pathology , Rotator Cuff/physiology , Rotator Cuff/surgery , Tensile Strength , Wound Healing/physiology
2.
Int J Sports Med ; 35(5): 438-42, 2014 May.
Article in English | MEDLINE | ID: mdl-24048911

ABSTRACT

Anterior cruciate ligament injury affects roughly 120,000 athletes in the United States every year. One of the most common techniques is the use of a bone-patellar tendon-bone graft. Graft harvest creates a sizeable defect in the remaining patellar tendon. Closure of this defect is based on surgeon preference. To date there has been no study on the effects of defect closure on the mechanical properties of remaining donor patellar tendon. The goal of this study was to investigate the effect of closure on both the strength and stiffness of the remaining patellar tendon. 7 pairs of fresh frozen cadaver patellar tendons were matched by tendon dimensions. Bone-patellar tendon-bone grafts were harvested from all of the specimens and then half of the paired tendons underwent defect closure. All of the donor tendons were then tested in a servohydraulic load frame to failure at a constant displacement rate at room temperature. This study found no differences in the load at failure, the engineering failure stress, stiffness or in the engineering modulus between the donor tendons that underwent defect closure versus those that did not.


Subject(s)
Anterior Cruciate Ligament Injuries , Anterior Cruciate Ligament/surgery , Bone-Patellar Tendon-Bone Grafting/methods , Tendons/physiology , Tendons/surgery , Tensile Strength , Biomechanical Phenomena , Cadaver , Humans , Knee Injuries/surgery , Transplantation, Autologous
3.
J Hand Surg Eur Vol ; 37(1): 8-13, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21987274

ABSTRACT

Benign extraosseous cartilage tumours of the hand and wrist comprise soft tissue chondromas, synovial chondromatosis and tenosynovial chrondromatosis. These tumours can significantly affect patients as they are often painful, functionally limiting and cosmetically displeasing. Although each tumour is generally considered to be a distinct entity, they share radiological and histopathological similarities. Occasionally, all three tumours may be seen in the same patient. This is an important consideration because of the risk of recurrence that may not necessarily occur at the same anatomical site but instead extend to different sites, such as a tendon sheath and/or joint.


Subject(s)
Hand/pathology , Neoplasms, Connective Tissue/pathology , Wrist/pathology , Chondroma/pathology , Chondromatosis, Synovial/pathology , Chondromatosis, Synovial/surgery , Diagnosis, Differential , Diagnostic Imaging , Humans , Neoplasms, Connective Tissue/surgery
4.
J Bone Joint Surg Br ; 90(5): 662-7, 2008 May.
Article in English | MEDLINE | ID: mdl-18450637

ABSTRACT

This study was undertaken to evaluate the safety and efficacy of retrievable inferior vena cava filters in high-risk orthopaedic patients. A total of 58 patients had a retrievable inferior vena cava filter placed as an adjunct to chemical and mechanical prophylaxis, most commonly for a history of previous deep-vein thrombosis or pulmonary embolism, polytrauma, or expected prolonged immobilisation. In total 56 patients (96.6%) had an uncomplicated post-operative course. Two patients (3.4%) died in the peri-operative period for unrelated reasons. Of the 56 surviving patients, 50 (89%) were available for follow-up. A total of 32 filters (64%) were removed without complication at a mean of 37.8 days (4 to 238) after placement. There were four filters (8%) which were retained because of thrombosis at the filter site, and four (8%) were retained because of incorporation of the filter into the wall of the inferior vena cava. In ten cases (20%) the retrievable filter was left in place to continue as primary prophylaxis. No patient had post-removal thromboembolic complications. A retrievable inferior vena cava filter, as an adjunct to chemical and mechanical prophylaxis, was a safe and effective means of reducing the acute risk of pulmonary embolism in this high-risk group of patients. Although most filters were removed without complications, thereby avoiding the long-term complications that have plagued permanent indwelling filters, a relatively high percentage of filters had to be left in situ.


Subject(s)
Pulmonary Embolism/prevention & control , Vena Cava Filters/adverse effects , Venous Thrombosis/prevention & control , Adolescent , Adult , Aged , Aged, 80 and over , Device Removal , Female , Humans , Immobilization/adverse effects , Male , Middle Aged , Orthopedic Procedures/adverse effects , Retrospective Studies , Risk Assessment , Risk Factors , Vena Cava, Inferior
5.
J Bone Joint Surg Br ; 89(6): 794-8, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17613507

ABSTRACT

Many orthopaedic surgeons believe that obese patients have a higher rate of peri-operative complications and a worse functional outcome than non-obese patients. There is, however, inconsistency in the literature supporting this notion. This study was performed to evaluate the effect of body mass index (BMI) on injury characteristics, the incidence of complications, and the functional outcome after the operative management of unstable ankle fractures. We retrospectively reviewed 279 patients (99 obese (BMI > or = 30) and 180 non-obese (BMI < 30) patients who underwent surgical fixation of an unstable fracture of the ankle. We found that obese patients had a higher number of medical co-morbidities, and more Orthopaedic Trauma Association type B and C fracture types than non-obese patients. At two years from the time of injury, however, the presence of obesity did not affect the incidence of complications, the time to fracture union or the level of function. These findings suggest that obese patients should be treated in line with standard procedures, keeping in mind any known associated medical co-morbidities.


Subject(s)
Ankle Injuries/surgery , Fractures, Bone/surgery , Obesity/complications , Postoperative Complications/etiology , Body Mass Index , Female , Follow-Up Studies , Fractures, Bone/diagnostic imaging , Fractures, Bone/pathology , Humans , Male , Radiography , Retrospective Studies
6.
J Bone Joint Surg Br ; 88(1): 84-9, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16365126

ABSTRACT

The type II Monteggia (posterior) lesion is a rare injury which is sometimes associated with ulnohumeral instability. We have reviewed 23 of 28 patients with this injury. A clinical and radiographic assessment was undertaken at follow-up. Functional outcome scores, including the Broberg and Morrey Index and the Disabilities of the Arm, Shoulder or Hand (DASH), were used. The results from the six patients with associated posterior ulnohumeral dislocation were compared with 17 without ulnohumeral injury. Those with dislocation had reduced movement of the elbow and had outcome scores indicative of greater disability compared to those without associated dislocation.


Subject(s)
Elbow Injuries , Joint Dislocations/surgery , Monteggia's Fracture/surgery , Multiple Trauma/surgery , Adult , Aged, 80 and over , Bone Plates , Disability Evaluation , Elbow Joint/diagnostic imaging , Elbow Joint/physiopathology , Elbow Joint/surgery , Female , Fracture Fixation, Internal/methods , Humans , Joint Dislocations/diagnostic imaging , Joint Instability/diagnostic imaging , Joint Instability/surgery , Male , Middle Aged , Monteggia's Fracture/diagnostic imaging , Multiple Trauma/diagnostic imaging , Radiography , Range of Motion, Articular , Retrospective Studies , Treatment Outcome
7.
Infect Immun ; 65(9): 3924-32, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9284172

ABSTRACT

Edwardsiella tarda is an enteric pathogen that causes diarrhea, wound infections, and death due to septicemia. This species is capable of invading human epithelial cell lines, and we have now been able to follow the entry and replication of E. tarda within tissue culture host cells. E. tarda escapes from the endocytic vacuole within minutes of entry and then replicates within the cytoplasm. Unlike other well-studied bacteria that replicate and reside in the cytoplasm, we never observed this organism moving directly from cell to cell; instead the bacteria spread by lysing the plasma membrane after several rounds of replication. Efforts to study the interactions of E. tarda with tissue culture cells are complicated by the presence of a potent cytotoxin that the bacterium produces. Using transposon mutagenesis, we isolated a noncytotoxic strain of E. tarda. This mutant is also defective for hemolysin production. The dual phenotype of this strain is consistent with the hypothesis that cytotoxicity is due to the previously characterized E. tarda hemolysin activity. The nonhemolytic strain is also unable to enter HEp-2 cells. The disrupted gene has sequence similarity to members of a family of genes required for transport and activation of the hemolysin genes, shlA and hpmA. A cosmid bearing 40 kb of E. tarda DNA, including wild-type copies of the E. tarda homologs of the transporter-activator protein and the hemolysin itself, confers hemolytic, cytotoxic, and invasive abilities upon normally nonhemolytic, noncytotoxic, and noninvasive strains of Escherichia coli. Sequence data indicate that the genes required for hemolytic activity are linked to a transposable element, suggesting that they arose in the E. tarda genome by horizontal transfer.


Subject(s)
Adhesins, Bacterial , Bacterial Proteins/genetics , Bacterial Proteins/physiology , Cytotoxins/metabolism , Enterobacteriaceae/genetics , Epithelium/microbiology , Hemolysin Proteins/physiology , Membrane Proteins , Amino Acid Sequence , Bacterial Adhesion , Cells, Cultured , DNA Transposable Elements , Endocytosis , Enterobacteriaceae/growth & development , Enterobacteriaceae/pathogenicity , Genes, Bacterial , Humans , Molecular Sequence Data , Mutagenesis, Insertional , Sequence Alignment , Sequence Homology, Amino Acid
8.
Science ; 276(5313): 707-12, 1997 May 02.
Article in English | MEDLINE | ID: mdl-9115190

ABSTRACT

The growing number of complete microbial genome sequences provides a powerful tool for studying the biology of microorganisms. In combination with assays for function, genomic-based approaches can facilitate efficient and directed research strategies to elucidate mechanisms of bacterial pathogenicity. As genomic information accrues, the challenge remains to construct a picture of the biology that accurately reflects how individual genes collaborate to create the complex world of microbial specialization.


Subject(s)
Bacteria/genetics , Bacteria/pathogenicity , Genome, Bacterial , Virulence/genetics , Animals , Bacterial Infections/microbiology , Databases, Factual , Gene Expression Regulation, Bacterial , Genetic Techniques , Humans , Sequence Analysis, DNA
9.
Emerg Infect Dis ; 2(4): 270-88, 1996.
Article in English | MEDLINE | ID: mdl-8969244

ABSTRACT

Recently, two novel but widespread themes have emerged in the field of bacterial virulence: type III secretion systems and pathogenicity islands. Type III secretion systems, which are found in various gram-negative organisms, are specialized for the export of virulence factors delivered directly to host cells. These factors subvert normal host cell functions in ways that seem beneficial to invading bacteria. The genes encoding several type III secretion systems reside on pathogenicity islands, which are inserted DNA segments within the chromosome that confer upon the host bacterium a variety of virulence traits, such as the ability to acquire iron and to adhere to or enter host cells. Many of these segments of DNA appear to have been acquired in a single step from a foreign source. The ability to obtain complex virulence traits in one genetic event, rather than by undergoing natural selection for many generations, provides a mechanism for sudden radical changes in bacterial-host interactions. Type III secretion systems and pathogenicity islands must have played critical roles in the evolution of known pathogens and are likely to lead to the emergence of novel infectious diseases in the future.


Subject(s)
Bacterial Proteins/metabolism , Gram-Negative Bacteria/pathogenicity , Gram-Negative Bacterial Infections/etiology , Host-Parasite Interactions , Bacterial Proteins/genetics , Chromosomes/genetics , DNA Transposable Elements/genetics , DNA, Bacterial/genetics , Gram-Negative Bacteria/genetics , Gram-Negative Bacterial Infections/genetics , Gram-Negative Bacterial Infections/metabolism , Humans , Plasmids/genetics , Virulence/genetics
10.
Curr Biol ; 6(5): 504-7, 1996 May 01.
Article in English | MEDLINE | ID: mdl-8805268

ABSTRACT

Vaccinia virus has recently been shown to induce inside its host cells the formation of actin tails very similar to those which facilitate the cell-to-cell spread of several pathogenic bacteria.


Subject(s)
Vaccinia virus/physiology , Actins/physiology , Membrane Fusion , Virus Replication
11.
Curr Biol ; 5(7): 706-9, 1995 Jul 01.
Article in English | MEDLINE | ID: mdl-7583109

ABSTRACT

Pathogenic bacteria express distinct sets of genes at different stages in their life cycles; inappropriate expression of normally repressed genes during host colonization can interfere with bacterial survival.


Subject(s)
Bacterial Physiological Phenomena , Bacteria/genetics , Bacteria/pathogenicity , Flagella , Gene Expression Regulation, Bacterial , Virulence/genetics , Virulence/physiology
12.
Nucleic Acids Res ; 22(15): 3187-93, 1994 Aug 11.
Article in English | MEDLINE | ID: mdl-7520570

ABSTRACT

We previously reported the isolation of PRP28, a gene in Saccharomyces cerevisiae whose activity is required for the first step of nuclear mRNA splicing in vivo. Sequence analysis revealed that PRP28 is included in the 'DEAD-box' gene family, members of which are thought to function as ATP-dependent RNA helicases. Genetic interactions led us to suggest that PRP28 is functionally associated with the U4/U5/U6 snRNP. We have now purified the PRP28 protein from S. cerevisiae and demonstrated that it is required for the first step of splicing in vitro. Interestingly, PRP28 is not a stably associated snRNP protein. Strand displacement assays indicate that PRP28 does not exhibit RNA helicase activity, suggesting that an additional factor or factors may be required for its activation.


Subject(s)
RNA Nucleotidyltransferases/metabolism , RNA Splicing , RNA, Messenger/metabolism , Saccharomyces cerevisiae/chemistry , Adenosine Triphosphatases/metabolism , Adenosine Triphosphate/pharmacology , Anthranilate Synthase/genetics , Antibodies/pharmacology , DEAD-box RNA Helicases , Escherichia coli/genetics , RNA/pharmacology , RNA Helicases , RNA Nucleotidyltransferases/genetics , RNA Nucleotidyltransferases/isolation & purification , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins
13.
Genes Dev ; 5(4): 629-41, 1991 Apr.
Article in English | MEDLINE | ID: mdl-2010088

ABSTRACT

We have isolated a cold-sensitive mutant of Saccharomyces cerevisiae in which the first step of mRNA splicing is inhibited. The growth and splicing defects are recessive and cosegregate, thus defining a single essential gene (PRP28). The wild-type PRP28 gene was cloned, and sequence analysis reveals extensive homology to a family of proteins that are thought to function as ATP-dependent RNA helicases. The cold sensitivity is caused by a glycine-to-glutamic acid change in a conserved sequence motif. Interestingly, double mutants containing conditional alleles of PRP28 and PRP24, which encodes a U6 snRNA-binding protein, are inviable. In addition, a suppressor of prp28-1 is a mutant allele of PRP8, which encodes a U5 protein, thus linking PRP28 with U5. These data are consistent with a scenario in which PRP28 acts to unwind the U4/U6 base-pairing interaction in the U4/U6/U5 snRNP, facilitating the first covalent step of splicing.


Subject(s)
Genes, Fungal , Genes, Suppressor , Multigene Family , Mutation , RNA Nucleotidyltransferases/genetics , RNA Splicing , RNA, Messenger/genetics , Saccharomyces cerevisiae/genetics , Amino Acid Sequence , Cold Temperature , Crosses, Genetic , Exons , Kinetics , Models, Genetic , Molecular Sequence Data , Oligonucleotide Probes , RNA Helicases , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/growth & development , Sequence Homology, Nucleic Acid
15.
S Afr Med J ; 68(6): 414-5, 1985 Sep 14.
Article in English | MEDLINE | ID: mdl-4035516

ABSTRACT

Intubation management of a patient with polyostotic fibrous dysplasia is described. The principles in planning for a difficult intubation are discussed.


Subject(s)
Anesthesia, Endotracheal/methods , Fibrous Dysplasia of Bone , Fibrous Dysplasia, Polyostotic , Intubation, Intratracheal , Adult , Face/abnormalities , Facial Bones/abnormalities , Hemorrhoids/surgery , Humans , Male , Spine/abnormalities
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