Ulnar collateral ligament reconstruction in high school baseball players: clinical results and injury risk factors

BACKGROUND: The incidence of ulnar collateral ligament injury has increased in baseball, especially at the high school level. HYPOTHESIS: Ulnar collateral ligament injury in high school baseball players is associated with overuse, high-velocity throwing, early throwing of breaking pitches, and improper warm-ups. STUDY DESIGN: Retrospective cohort study. METHODS: Follow-up physical examination and questionnaire data were collected at an average of 35 months after ulnar collateral ligament reconstruction from 27 former high school baseball players. Six potential risk factors were evaluated: year-round throwing, seasonal overuse, event overuse, throwing velocity more than 80 mph, throwing breaking pitches before age 14, and inadequate warm-ups. RESULTS: Overall, 74% returned to baseball at the same or higher level. Patients averaged 3 potential risk factors, and 85% demonstrated at least one overuse category. Of the pitchers, the average self-reported fastball velocity was 83 mph, and 67% threw breaking pitches before age 14. CONCLUSIONS: The success rate of ulnar collateral ligament reconstruction in high school baseball players is nearly equal to that in more mature groups of throwers. Overuse of the throwing arm and throwing breaking pitches at an early age may be related to their injuries. Special attention should be paid to elite-level teenage pitchers who throw with high velocity.     

Wear evaluation of cobalt-chromium alloy for use in a metal-on-metal hip prosthesis

Wear of the polyethylene in total joint prostheses has been a source of morbidity and early device failure, which has been extensively reported in the last 20 years. Although research continues to attempt to reduce the wear of polyethylene joint-bearing surfaces by modifications in polymer processing, there is a renewed interest in the use of metal-on-metal bearing couples for hip prostheses. Wear testing of total hip replacement systems involving the couple of metal or ceramic heads on polymeric acetabular components has been performed and reported, but, until recently, there has been little data published for pin-on-disk or hip-simulator wear studies involving the combination of a metallic femoral head component with an acetabular cup composed of the same or a dissimilar metal. This study investigated the in vitro wear resistance of two cobalt/chromium/molybdenum alloys, which differed primarily in the carbon content, as potential alloys for use in a metal-on-metal hip-bearing couple. The results of pin-on-disk testing showed that the alloy with the higher (0.25%) carbon content was more wear resistant, and this alloy was therefore chosen for testing in a hip-simulator system, which modeled the loads and motions that might be exerted clinically. Comparison of the results of metal-on-polyethylene samples to metal-on-metal samples showed that the volumetric wear of the metal-on-polyethylene bearing couple after 5,000,000 cycles was 110-180 times that for the metal-bearing couple. Polyethylene and metal particles retrieved from either the lubricant for pin-on-disk testing or hip simulator testing were characterized and compared with particles retrieved from periprosthetic tissues by other researchers, and found to be similar. Based upon the results of this study, metal-on-metal hip prostheses manufactured from the high carbon cobalt/chromium alloy that was investigated hold sufficient promise to justify human clinical trials.     

360-feedback in health care management: a field study

In recent years, organizations representing all types of industries, including health care, have adopted the 360-feedback approach with the goal of strengthening leader performance. But while 360-feedback enjoys a high level of face validity, current research shows that it is not problem-free and often fails to achieve its goals without proper development and implementation. This research, conducted in a large public hospital, surveyed the top management team of 49 executives who participated in a 360-feedback project beginning in February 2001. The survey, designed to solicit opinions about the effectiveness of the 360-feedback project, resulted in several recommendations to improve the process: One, both mentors and participants (raters and those rated) should be formally trained to improve the feedback process. Two, participants--both raters and those rated--should be significantly involved in 360-feedback planning and development efforts. Three, the 360-feedback process should be linked to hospital objectives. Four, the 360-feedback process should focus not only on interpersonal issues but departmental and organizational goals as well. First and foremost, our findings show that regardless of how popular a management development program may be, no technique for improving management and organizational effectiveness, including 360-feedback, will work unless properly designed and implemented.     

Safety of anthrax vaccine: an expanded review and evaluation of adverse events reported to the Vaccine Adverse Event Reporting System (VAERS)

PURPOSE: To assess the safety of a licensed anthrax vaccine (AVA) given to more than 500,000 US military personnel, through review and medical evaluation of adverse events (AEs) reported to the Vaccine Adverse Event Reporting System (VAERS). METHODS: AEs were summarized by person, vaccine lot, type, frequency and impact. A Delphic approach was used to tentatively assess causality in an effort to detect serious AEs (SAEs) or other medically important AEs (OMIAEs) possibly attributable to AVA. RESULTS: The Anthrax Vaccine Expert Committee (AVEC) reviewed 1841 reports describing 3991 AEs (9.4 reports/10,000 doses of AVA) that were submitted to VAERS from 1Q1998 through 4Q2001. One hundred forty-seven reports described an SAE or OMIAE, of which 26 were tentatively rated as possible, probable or certain consequences of vaccination (injection-site reaction [12], 'anaphylactic-like reaction' [5] and eight other systemic AEs [1-2 each]). CONCLUSIONS: This review produced no evidence for an unusual rate of any SAE or OMIAE attributable to AVA. It supported an earlier impression that AVA may cause significant local inflammation and should be administered over the deltoid rather than the triceps to avoid direct or compression injury to the ulnar nerve. The subjects of VAERS reports tended to be older than all recipients of AVA. Females generally had and/or reported AEs more often than males, but transient articular reactions were surprisingly more common in males. Variations in the frequency or severity (as judged by hospitalization and/or loss of duty) of reported AEs did not suggest a significant problem with (1) a particular lot of AVA, (2) recurrent AEs after multiple doses or (3) vaccination of persons with a concomitant illness or those given other vaccines or medications.     

Serotyping of Toxoplasma gondii infections in humans using synthetic peptides

To determine whether the characteristics of disease due to Toxoplasma gondii (toxoplasmosis) are dependent on the infecting strain, we have developed an enzyme-linked immunosorbent assay for typing strains that uses infection serum reacted against polymorphic peptides derived from Toxoplasma antigens SAG2A, GRA3, GRA6, and GRA7. Pilot studies with infected mice established the validity of the approach, which was then tested with human serum. In 8 patients who had Sabin-Feldman dye test titers >64 and for whom the infecting strain type was known, the peptides correctly distinguished type II from non-type II infections. ELISA analysis of a second group of 10 infected pregnant women from whom the parasite strain had not been isolated gave a clear prediction of the strain type causing infection. This method should allow statistically significant data to be obtained about whether different strain types cause disease with different characteristics.     

Mechanisms involved in persistent facilitation of neuromuscular synapses in aplysia

Synaptic plasticity can last from a fraction of a second to weeks depending on how it was induced. The mechanisms that underlie short-, intermediate-, and long-term plasticity have been intensively studied at central synapses of both vertebrates and invertebrates; however, peripheral plasticity has not received as much attention. In this study, we investigated the mechanisms that contribute to a persistent form of plasticity at neuromuscular synapses in buccal muscle I3a of Aplysia. These synapses are reversibly facilitated by the small cardioactive peptide (SCP), a peptide cotransmitter that is intrinsic to the motor neurons, and persistently facilitated by serotonin (5HT) released from modulatory neurons that are extrinsic to the motor circuit. Many of the short-term effects of 5HT and SCP are mediated by the cAMP pathway, but little is known about the mechanisms that underlie persistent modulation. We were able to eliminate several possible mechanisms. One of these was the possibility that the apparent reversal of SCP's effects was due to desensitization of the SCP receptor. Superfusion for longer periods or with higher concentrations of SCP indicate that the SCP receptors do not desensitize. We also determined that new protein synthesis is not required for the persistent facilitation of EJPs. Another possibility was that 5HT was taken up and slowly re-released. Our results suggest that this mechanism is also unlikely. Activation of the cAMP pathway does not appear to mediate persistent effects; however, 5HT as well as SCP does cause persistent increases in cAMP levels that can prime I3a synapses and increase the effectiveness of activators of the cAMP pathway. Instead, the persistent effects of 5HT are mimicked by phorbol, suggesting that protein kinase C or an Aplysia homologue of unc13 may mediate these effects. These results, in combination with results from experiments on the sensory neurons that contribute to withdrawal reflexes in Aplysia, suggest that the mechanisms for intermediate- and long-term facilitation may reside in all of the synapses involved in the sensory to motor response reflex.     

Feasibility and value of video-assisted thoracoscopic surgery wedge excision of small pulmonary nodules in patients with malignancy

PURPOSE: Advances in CT scanning have presented physicians with the challenge of diagnosing small (< 10 mm) or deep (> 5 mm) pulmonary nodules (SmPNs) in patients with known malignancies during workup or follow-up. Wedge excision of SmPNs is difficult with video-assisted thoracoscopic surgery (VATS) and often requires the performance of a thoracotomy. The value of the early detection of metastatic disease must be weighed against the morbidity (ie, thoracotomy) that is necessarily involved in obtaining the information. Little is known about the incidence of metastases in this subset of patients. We describe a VATS technique that allows the reliable excisional biopsy of SmPNs and present our findings in this patient population. METHODS: Using CT scan localization, 150 micro Ci technetium sulfur colloid is injected into the area of the pulmonary nodule. Additional blue dye is injected at the lung surface. During VATS, a sterile gamma probe is used to identify the area of radioactivity and plan placement of staple lines performed by an endostapling instrument. Palpation and the presence of radioactivity in the specimen supported the resection of the correct nodule, and CT scan findings confirmed the procedure. Between March 2000 and January 2001, 17 patients with known malignancies and SmPNs underwent VATS excisional biopsies. Six patients received a new diagnosis of malignancy, and 11 patients were in follow-up of a previously treated malignancy. The malignancies included the following: breast (four patients), head and neck (four patients), pancreas (two patients), lymphoma (two patients), lung (one patient), prostate (one patient), rectal (one patient), seminoma (one patient), and urethral (one patient). RESULTS: All lesions were successfully resected on the first try. Nodules were removed from 10 segments and all lobes. The mean (+/-/SD) nodule size was 9.2 +/- 3.6 mm, and the mean depth was 9.4 +/- 5.2 mm. Fourteen of 17 nodules (82.4%) could be neither seen nor felt using standard VATS techniques. Diagnoses included metastatic (four patients), new primary lung cancer (one patient), acid-fast bacillus (one patient), granuloma (seven patients), carcinoid (two patients), and inflammatory pseudotumor (two patients). Among these lesions, 29.4% were malignant, and 35.3% of patients received a diagnosis that altered their therapy. Five of 12 SmPNs (41.7%) < 10 mm in size were malignant. The median length of hospital stay was 2 days. Patients returned to full activity within 1 week. CONCLUSION: VATS excision of SmPNs after CT scan localization with radiolabeled technetium is reliable, reproducible, and associated with minimal morbidity. The technique prevented thoracotomies in 82.4% of patients. Despite the small size of these lesions, malignancy was found 29.4% of the time. This technique allows the early diagnosis of SmPNs, with low morbidity, in patients with known malignancies. Clinical implications: The reliability of this technique, the high incidence of malignancy, and the reduction in morbidity from undergoing excisional biopsy procedures will encourage the clinician to strive for earlier and more aggressive diagnoses of SmPNs.     

Interface fluid after laser in situ keratomileusis

PURPOSE: To describe a case of interface fluid after laser in situ keratomileusis (LASIK) and review the literature on this rare complication after LASIK. METHODS: We present a case report and literature review. Articles for this review were chosen from electronic database and manual literature searches. MEDLINE searches were made from 1990 to April 2002, using the key words "interface fluid" and "LASIK." RESULTS: A 40-year-old man had uneventful LASIK for residual refractive error from previous penetrating keratoplasty in his right eye. Diffuse lamellar keratitis began 1 day postoperatively. Topical corticosteroids were administered. Six weeks after LASIK, a layer of interface fluid developed. Intraocular pressure was 9 mmHg when measured centrally by Goldmann applanation tonometry and 30 mmHg by Tono-pen tonometry. The interface fluid resolved with antiglaucoma agents and corticosteroids combined with cyclosporine. CONCLUSIONS: This case, along with other reported cases, demonstrate the clinical features of interface fluid after LASIK.