Biomedical subjects

B J Cole

Publications and source records attributed to B J Cole.

At least 19 recordsLinked to original sources

PubMed2006

The chemical defensome: environmental sensing and response genes in the Strongylocentrotus purpuratus genome.

Metazoan genomes contain large numbers of genes that participate in responses to environmental stressors. We surveyed the sea urchin Strongylocentrotus purpuratus genome for homologs of gene families thought to protect against chemical stressors; these genes collectively comprise the 'chemical defensome.' Chemical defense genes include cytochromes P450 and other oxidases, various conjugating enzymes, ATP-dependent efflux transporters, oxidative detoxification proteins, and transcription factors that regulate these genes. Together such genes account for more than 400 genes in the sea urchin genome. The transcription factors include homologs of the aryl hydrocarbon receptor, hypoxia-inducible factor, nuclear factor erythroid-derived 2, heat shock factor, and nuclear hormone receptors, which regulate stress-response genes in vertebrates. Some defense gene families, including the ABCC, the UGT, and the CYP families, have undergone expansion in the urchin relative to other deuterostome genomes, whereas the stress sensor gene families do not show such expansion. More than half of the defense genes are expressed during embryonic or larval life stages, indicating their importance during development. This genome-wide survey of chemical defense genes in the sea urchin reveals evolutionary conservation of this network combined with lineage-specific diversification that together suggest the importance of these chemical stress sensing and response mechanisms in early deuterostomes. These results should facilitate future studies on the evolution of chemical defense gene networks and the role of these networks in protecting embryos from chemical stress during development.

Acclimatization↗

PubMed2001

Arthroscopic Bankart repair with the Suretac device for traumatic anterior shoulder instability in athletes.

Arthroscopic treatment of anterior shoulder instability in the athlete has evolved tremendously over the past decade. Currently, most techniques include the use of suture and suture anchors. However, the variety of arthroscopic instruments and techniques that are available shows the complexity of intra-articular tissue fixation, which includes anchor placement, suture passing, and knot tying. Stabilization using the Suretac device (Acufex Microsurgical, Mansfield, MA) simplifies tissue fixation by eliminating the need for arthroscopic suture passing and intra-articular knot tying. However, a successful outcome is highly dependent on accurate patient selection. Preoperative evaluation, examination under anesthesia, and the pathoanatomy defined by a thorough arthroscopic examination suggest the most effective treatment strategy. The ideal candidate for shoulder stabilization using the Suretac device is an athlete with a relatively pure traumatic anterior instability pattern with detachment pathology (e.g., Bankart lesion) and minimal capsular deformation.

Absorbable Implants↗

PubMed2001

Effect of bipolar radiofrequency energy on human articular cartilage. Comparison of confocal laser microscopy and light microscopy.

PURPOSE: To evaluate chondrocyte viability using confocal laser microscopy (CLM) following exposure to bipolar radiofrequency energy (bRFE) and to contrast CLM with standard light microscopy (LM) techniques. TYPE OF STUDY: In vitro analysis using chondromalacic human cartilage. METHODS: Twelve fresh chondral specimens were treated with the ArthroCare 2000 bRFE system (ArthroCare, Sunnyvale, CA) coupled with 1 of 2 types of probes and at 3 energy delivery settings (S2, S4, S6). A sham-operated group was treated with no energy delivered. Specimens were analyzed for chondrocyte viability and chondral morphology with CLM using fluorescent vital cell staining and with LM using H&E and safranin-O staining. RESULTS: LM with H&E staining showed smoothing of fine fronds of fibrillated cartilage; thickened fronds were minimally modified. Chondrocyte nuclei were present and not morphologically different than nuclei within sham-operated and adjacent untreated regions. LM with safranin-O staining showed a clear demarcation between treated and untreated regions. CLM, however, showed chondrocyte death: the depth and width of chondrocyte death increased with increasing bRFE settings. CONCLUSIONS: CLM showed that bRFE delivered through the probes investigated created significant chondrocyte death. These changes were not apparent using LM techniques.

Aged↗

PubMed2001

Arthroscopic shoulder stabilization with suture anchors: technique, technology, and pitfalls.

Arthroscopic treatment of anterior shoulder instability has evolved significantly during the past decade. Currently, most techniques include the use of suture and suture anchors. A successful outcome is highly dependent on accurate patient selection. Preoperative evaluation, examination with the patient under anesthesia, and defining the pathoanatomy by a thorough arthroscopic examination determine the most effective treatment strategy. Technical skills include the surgeon's ability to accomplish anchor placement, suture passage, and arthroscopic knot tying. Various instruments and techniques are available to facilitate arthroscopic reconstruction. In properly selected patients and with good surgical technique, outcomes should approximate or exceed traditional open stabilization techniques.

Arthroscopes↗

PubMed2001

The anatomy and histology of the rotator interval capsule of the shoulder.

Forty-seven rotator interval regions from fetuses and 10 fresh-frozen rotator interval regions from adult cadavers were evaluated by gross dissection and light microscopy. Specimens from adults also were evaluated with ultrasound and magnetic resonance imaging. An analysis of 37 fetal specimens (> 14 weeks gestation) revealed two rotator interval types: Type I (9 of 37) was defined by a contiguous bridge of capsule consisting of poorly organized collagen fibers. A Type II rotator interval (28 of 37) had a complete defect covered by only a thin layer of synovium. Similar to the Type II rotator interval in the fetus, a rotator interval defect was present in six of eight specimens from adults. Histologically, the capsular tissue within the rotator interval consisted of poorly organized collagen fibers in specimens from the fetus and adult. Maximal opening of the rotator interval was seen by ultrasound with internal rotation and downward traction of the hyperextended arm in the coronal, oblique, and sagittal planes. Magnetic resonance imaging of the rotator interval region permitted anatomic evaluation. The complete absence of tissue in 28 of 37 fetuses suggests that the rotator interval defect is congenital. The authors recommend that surgeons carefully evaluate the integrity of the tissue within the rotator interval. When rotator interval closure is desired such as in patients with a persistent sulcus sign after arthroscopic stabilization, suturing the edges of more substantial tissue immediately adjacent to the boundaries of the rotator interval region would seem prudent.

Adult↗

PubMed2001

Male size, sperm transfer, and colony fitness in the western harvester ant, Pogonomyrmex occidentalis.

Mating success in the western harvester ant, Pogonomyrmex occidentalis, increases with male size. We tested the hypothesis that increased mating success increases male fitness and the fitness of colonies that make large males by comparing the sperm content of males prior to and at the conclusion of the mating swarm. The number of sperm a male initially possesses is a function of male size, and large males transfer a greater proportion of their sperm than do small males. For colonies, the payoff per unit of investment is an increasing function of male size, and investment in large males is not equivalent to investing in a larger number of small males. Allocation ratios in species that show size variation in reproductives may need to be modified by the individual fitness functions.

Animals↗

PubMed2001

Outpatient anterior cruciate ligament reconstruction: an analysis of charges and perioperative complications.

All outpatient anterior cruciate ligament (ACL) reconstructions using patellar tendon autograft performed at an accredited outpatient surgical center between 1994 and 1998 were prospectively studied. Hospital charges pertaining to the procedures were examined, and perioperative morbidities that might be attributed to an outpatient procedure were evaluated. The study group comprised 284 patients; average patient age at surgery was 28.7 years. Patients were subgrouped into group 1 (isolated ACL reconstructions; n=163), group 2 (ACL reconstructions and meniscal repair; n=48), and group 3 (ACL reconstructions and partial meniscectomy; n=73). Surgicenter facility charges, reoperation rate, complication rate, motion, pain management, hospital emergency room visits, hospital admission, and outpatient surgical facility visits were analyzed. Historical controls from our hospital and our initial outpatient pilot study (May 1994 through November 1995) were used as financial controls. The average surgical center charge for all patients was $3,443. On average, there was a $600 increase for all subgroups from May 1994 through November 1995 compared to December 1995 through August 1998. In the latter time interval, the fixed facility charges were $3,150, $4,075, and $4,275 for groups 1, 2, and 3, respectively. Overall, 19 (7%) patients required a reoperation including 7 (2.5%) patients who required arthroscopic debridement for symptomatic motion deficits. This study expands on our initial published report regarding hospital charges pertaining to an outpatient ACL reconstruction. Extended over another 4 years, we noted slight increases reflective of regional inflationary increases. Compared to our initial inpatient study (1988-1993), significant charge reductions were maintained. This study demonstrated a low complication rate and high patient subjective satisfaction level.

Adolescent↗

PubMed2000

Arthroscopic versus open Bankart repair for traumatic anterior shoulder instability.

After more than 15 years of experience, arthroscopic shoulder stabilization is becoming less controversial. Historically, recurrence rates following arthroscopic stabilization have been higher than with open stabilization. Although a negligible advantage may exist in terms of expedited postoperative rehabilitation and improved postoperative recovery of motion, critics suggest that its use in contact athletes be limited. The indications for arthroscopic stabilization are expanding, in part, because of improved understanding of the pathophysiology of shoulder instability. Understanding the mechanism of recurrent instability following arthroscopic stabilization offers clues to how physicians can prevent unsatisfactory results in the future. With newer instrumentation and the ability to thermally treat capsular tissue, coexisting pathology, such as capsular plastic deformation, rotator interval lesions, and unrecognized intra-articular pathology, can now be addressed arthroscopically. The judicious use of these techniques is warranted until long-term study results become available. Ideal patients for arthroscopic Bankart repair have a discrete Bankart lesion; a robust, well-developed IGHL; no significant capsular laxity or intraligamentous injury; and an absence of concomitant intra-articular pathology. Additional findings on MR imaging or CT evidence of a discrete labral lesion and pure unidirectional anterior instability during EUA are also good prognostic indicators for arthroscopic Bankart repair. Arthroscopic criteria that render patients less appropriate for an arthroscopic repair include capsular injury, capsular laxity, a bony Bankart lesion, glenohumeral arthritis, and a rotator cuff tear. The authors' believe that either absent or patulous, poorly developed glenohumeral ligaments represent a poor prognostic indicator for a successful outcome following standard arthroscopic Bankart repair. Individuals with poor-quality tissue are more predictably managed using open capsulorrhaphy. Patients with pathologic ligamentous laxity in the absence of a Bankart lesion or any apparent intraligamentous injury to the IGHL are also good candidates for treatment with an open capsulorrhaphy. Findings determined from a thorough physical examination, EUA, and the pathology appreciated during diagnostic arthroscopy help to appropriately choose the surgical procedure that effectively addresses pathology in patients who present with recurrent traumatic anterior instability. Patient preferences and surgical experience are important determinants of procedure selection, and current arthroscopic techniques lack the versatility to uniformly address the entire spectrum of pathology that may be associated with traumatic anterior shoulder instability. Surgeons should always be prepared to convert to an open-stabilization technique if the arthroscopic technique is deficient in addressing all pathology identified at the time of surgery.

Arthroscopy↗

PubMed2000

Comparison of arthroscopic and open anterior shoulder stabilization. A two to six-year follow-up study.

BACKGROUND: Sixty-three consecutive patients with recurrent traumatic anterior shoulder instability underwent operative repair. The decision to select either arthroscopic Bankart repair or open capsular shift was based on the findings of an examination under anesthesia and the findings at the time of arthroscopy. Thirty-nine patients with only anterior translation on examination under anesthesia and a discrete Bankart lesion underwent arthroscopic Bankart repair with use of absorbable transfixing implants. Twenty-four patients with inferior translation in addition to anterior translation on examination under anesthesia and capsular laxity or injury on arthroscopy underwent an open capsular shift. METHODS: Treatment outcomes for each group were determined according to the scoring systems of Rowe et al., the American Shoulder and Elbow Surgeons, and the Short Form-36. Failure was defined as recurrence of dislocation or subluxation or the finding of apprehension. Fifty-nine (94 percent) of the sixty-three patients were examined and filled out a questionnaire at a mean of fifty-four months (range, twenty-seven to seventy-two months) following surgery. RESULTS: There were no significant differences between the two groups with regard to the prevalence of failure or any of the other measured parameters of outcome. An unsatisfactory outcome occurred after nine (24 percent) of thirty-seven arthroscopic repairs and after four (18 percent) of twenty-two open reconstructions. All cases of recurrent instability resulted from a reinjury in a contact sport or a fall less than two years postoperatively. The treatment groups did not differ with regard to patient age, hand dominance, mechanism of initial injury, duration of follow-up, or delay until surgery. Measured losses of motion were minimal and, with the exception of forward elevation, slightly more of which was lost after the open capsular shifts (p = 0.05), did not differ between the two forms of treatment. Approximately 75 percent of the patients in each group returned to their favorite recreational sports with no or mild limitations. As rated by the patients, the result was good or excellent after thirty-one (84 percent) of the arthroscopic procedures and after twenty (91 percent) of the open procedures. CONCLUSIONS: Arthroscopic and open repair techniques for the treatment of recurrent traumatic shoulder instability yield comparable results if the procedure is selected on the basis of the pathological findings at the time of surgery.

Adolescent↗

PubMed1999

The multiple ligament injured knee.

Knee dislocations are complex cases requiring careful initial management to prevent devastating consequences caused by limb ischemia from vascular injury. Initial treatment includes gentle reduction and neurovascular assessment including an arteriogram and vascular reconstruction when necessary. Evaluation by examination and MR imaging will help define all ligamentous and associated pathology. All combined instabilities are repaired or reconstructed at the time of surgery. Early intervention within 3 weeks is preferred, as acute reconstruction is technically easier and more predictable than chronic reconstruction. Allografts are particularly helpful in these complex and time consuming knee injuries. Postoperative rehabilitation consists of initial immobilization followed by a supervised rehabilitation program emphasizing range of motion and strengthening.

Angiography↗

PubMed1999

Bone marrow and recombinant human bone morphogenetic protein-2 in osseous repair.

Bone marrow stem cells and recombinant human bone morphogenetic protein-2 each has the capacity to repair osseous defects. Recombinant human bone morphogenetic proteins require the presence of progenitor cells to function. It is hypothesized that a composite graft of recombinant human bone morphogenetic protein-2 and marrow would be synergistic and could result in superior grafting to autogenous bone graft. Syngeneic Lewis rats with a 5-mm critical sized femoral defect were grafted with recombinant human bone morphogenetic protein-2 and marrow, recombinant human bone morphogenetic protein-2, marrow, syngeneic cancellous bone graft, or carrier alone (control). Serial radiographs (3, 6, 9, 12 weeks) and torque testing (12 weeks) were performed. Bone formation and union were determined. The recombinant human bone morphogenetic protein-2 and marrow composite grafts achieved 100% union at 6 weeks. Recombinant human bone morphogenetic protein alone achieved 80% union by week 12. Both groups yielded a higher union rate and superior mechanical properties than did either syngeneic bone graft (38%) or marrow (47%) alone. The superior performance of recombinant human bone morphogenetic protein-2 combined with bone marrow in comparison with each component alone strongly supports a biologic synergism. This experimentation shows the clinical importance of establishing operative site proximity for the osteoinductive factors and responding progenitor cells.

Animals↗

PubMed1998

Optimizing hospital reimbursement through physician awareness: a step toward better patient care.

We instituted a training program to improve the overall accuracy of medical record coding through greater physician awareness to enhance hospital reimbursement and maintain quality patient care. A physician-targeted course reviewed the prospective payment system, diagnosis-related group guidelines, ambulatory surgery reimbursement, and the relationship between accurate physician documentation and medical record coding. Annual increases in charges from prospective surgical case assignment, proper conversion of outpatient to inpatient status, and more accurate coding of inpatient comorbidities and complications led to an estimated increase in hospital charges of $1.6 million.

Ambulatory Surgical Procedures↗

PubMed1997

Malignant fibrous histiocytoma at the site of a total hip replacement: review of the literature and case report.

Tumors developing in association with metallic implants are being reported with increasing frequency in the orthopedic literature. The authors report the tenth case of malignant fibrous histiocytoma associated with a total hip replacement. The diagnosis was made during an evaluation for rapid radiographic osteolysis surrounding the femoral component detected less than 1 year after revision of a hemiarthroplasty to a total hip replacement. The short latency period and aggressiveness of this tumor mimicking rapid osteolysis prompted a review of the literature, etiology and significance of implant-associated malignant fibrous histiocytoma.

Arthroplasty, Replacement, Hip↗

PubMed1997

Use of bone morphogenetic protein 2 on ectopic porous coated implants in the rat.

The ability of recombinant human bone morphogenetic protein 2 to remain osteoinductive and stimulate appositional bone formation on a porous coated implant was tested in a rat quadriceps muscle pouch. Implants with or without hydroxyapatite were used to compare the effects on bone formation of two different does (23 micrograms or 46 micrograms) of recombinant human bone morphogenetic protein 2 against controls as evidenced by contact radiography, histologic examination, and backscatter scanning electron microscopic analysis. Cylindrical plasma sprayed porous titanium implants were placed bilaterally within a muscle pouch surgically created in 48 Lewis rats. Implants treated with recombinant human bone morphogenetic protein 2 formed significantly more bone than did control implants independent of the dose or presence of hydroxyapatite. In all implants with bone formation, osteoinduction via endochondral ossification began within 7 days. By 21 days, cartilage largely was replaced by bone and marrow. The results of this ectopic, nonweightbearing in vivo assay suggest that recombinant human bone morphogenetic protein 2 remains biologically active after application to a titanium implant and may be used to enhance appositional bone formation by direct application to the implant surface.

Analysis of Variance↗

PubMed1996

AMPA antagonists differ from NMDA antagonists in their effects on operant DRL and delayed matching to position tasks.

The effects of NBQX (1.56-7.5 mg/kg, i.p.), a competitive antagonist at the AMPA type of glutamate receptor, were studied in two operant behavioural paradigms, differential reinforcement of low response rates (DRL), and delayed matching to position (DMTP), which have been shown to be sensitive to the antagonists of the NMDA type of glutamate receptor. Additionally, the non-competitive AMPA antagonist, GYKI 52466 (7.5-15 mg/kg, i.p.), was studied in the DRL procedure. As a positive control, the non-competitive NMDA antagonist, MK 801 (0.0125-0.1 mg/kg, i.p.) was studied in both procedures. During performance of the DRL schedule, MK 801 increased response rates in a dose dependent manner, and decreased the number of reinforcers obtained. The increase in response rates could be attributed to both a shift in the median inter-response time (IRT) to shorter intervals, and to a marked, dose dependent increase in the occurrence of bursts of responses (responses occurring within 3 s of a previous response). In contrast, NBQX and GYKI 52466 both decreased response rates in a dose dependent fashion, and did not shift the distribution of the IRTs, or increase the occurrence of burst responding. In the DMTP procedure, accuracy of matching decreased with increasing delay (up to 30 s, between presentation of sample and opportunity to respond). NBQX disrupted responding at a dose of 7.5 mg/kg, but lower doses were ineffective in influencing accuracy of performance of the discrimination. In contrast, MK 801 (0.1 and 0.2 mg/kg) reduced accuracy of matching at all delays, while tending to increase the speed of responding. These data demonstrate differences in the effects of AMPA and NMDA antagonists on performance of well trained operant behaviour.

Animals↗

PubMed1995

Double dissociation between the effects of muscarinic antagonists and benzodiazepine receptor agonists on the acquisition and retention of passive avoidance.

Both muscarinic antagonists, such as scopolamine, and benzodiazepine receptor (BZR) agonists, such as diazepam, produce a reliable impairment in the performance of one trial passive avoidance. Such deficits are frequently interpreted as drug-induced amnesia. However, these deficits could also result from a learning impairment. The present experiments compared the effects of two BZR agonists, lorazepam (0, 0.125, 0.25, and 0.375 mg/kg, IP) and diazepam (0, 0.78, 1.56, and 3.13 mg/kg, IP) with the effects of two muscarinic antagonists, scopolamine (0, 0.6, 0.8 and 1.0 mg/kg, SC) and atropine (0, 15, 30 and 60 mg/kg, IP) on a multiple trial passive avoidance task. In this procedure, the rats were trained with a 5-min inter-trial interval until a learning criterion was achieved. Retention was assessed 24 h later. This enabled the effects of the drugs on the acquisition and the retention of a passive avoidance response to be dissociated. Both atropine and scopolamine produced a marked impairment in the acquisition of the passive avoidance response, but did not impair retention. In contrast, diazepam and lorazepam did not alter the acquisition of a passive avoidance response, but did produce a dose-dependent impairment of retention. These results therefore demonstrate a double dissociation between the effects of muscarinic antagonists and BZR agonists on the acquisition and retention of passive avoidance.

Animals↗

PubMed1995

Effects of benzodiazepine receptor partial inverse agonists in the elevated plus maze test of anxiety in the rat.

The present series of experiments examined the effects of five benzodiazepine receptor (BZR) partial inverse agonists on the behaviour of rats on an elevated plus maze. The drugs were tested in a standard plus maze with 3-cm walls added to the open arms, as this has been shown to increase the sensitivity of the plus maze to anxiogenic-like drugs effects (Jones and Cole 1995). The drugs tested were FG 7142 (0-100 mg/kg), beta-CCE (0-30 mg/kg), ZK 132,556 (0-100 mg/kg), ZK 90 886 (0-30 mg/kg) and Ro 15-4513 (0-30 mg/kg). In addition, to allow a comparison with previous studies, the effects of three reference substances, DMCM (0-2.5 mg/kg), pentylenetetrazol (PTZ; 0-30 mg/kg) and yohimbine (0-5 mg/kg), were also examined. These three reference compounds produced a dose-dependent reduction in the duration of open arm exploration and the total number of open arm entries, indicative of anxiogenic-like effects. DMCM produced significant effects at the doses of 1.25 and 2.5 mg/kg, PTZ at 30 mg/kg, and yohimbine at 5 mg/kg. The BZR partial inverse agonist FG 7142 (10, 30 and 100 mg/kg) also reduced the duration of open arm exploration and the total number of arm entries. The minimally effective dose resulted in a receptor occupancy of approximately 80%. Ro 15-4513 also produced anxiogenic-like effects, but only at a dose (30 mg/kg) that resulted in a receptor occupancy of approximately 95%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Cost awareness and cost containment at the Hospital for Special Surgery. Strategies and total hip replacement cost centers.

To help balance the operating budget of The Hospital for Special Surgery, which was encountering an annual major deficit of $4 million in 1989, a program of cost awareness leading to cost containment was instituted in 1990. Costs of supplies, implants, and equipment were identified and reviewed by the hospital staff, including orthopaedic surgeons, orthopaedic residents, health care personnel, and administration, for cost effectiveness. Methods to accomplish the goals included structuring committees for information; workshops organized by different services to affect change; feedback to health care professionals through posters and newsletters; and statistical identification for continued education. Major cost savings resulted from recycling wasted implants, reduction of costly implants, and reduction of unnecessary supplies. As a result, vendors had been challenged, leading to more competitive prices. This program has opened new avenues of cost reduction without sacrificing quality of medical care and has contributed to a breakdown of barriers between medical staff, administration, and finance, leading to a strong hospital-team commitment. The price of health care in the United States in 1993 exceeded $900 billion. Health care expenditures now account for approximately 14% of the gross domestic product. Health care costs have been rising faster than the inflation rate for more than a decade. The result is the current national focus on containment of health care expenditures.

Cost Control↗