Angiotensin type 1a receptors on corticotropin-releasing factor neurons contribute to the expression of conditioned fear.

Although generally associated with cardiovascular regulation, angiotensin II receptor type 1a (AT1a R) blockade in mouse models and humans has also been associated with enhanced fear extinction and decreased post-traumatic stress disorder (PTSD) symptom severity, respectively. The mechanisms mediating these effects remain unknown, but may involve alterations in the activities of corticotropin-releasing factor (CRF)-expressing cells, which are known to be involved in fear regulation. To test the hypothesis that AT1a R signaling in CRFergic neurons is involved in conditioned fear expression, we generated and characterized a conditional knockout mouse strain with a deletion of the AT1a R gene from its CRF-releasing cells (CRF-AT1a R((-/-)) ). These mice exhibit normal baseline heart rate, blood pressure, anxiety and locomotion, and freeze at normal levels during acquisition of auditory fear conditioning. However, CRF-AT1a R((-/-)) mice exhibit less freezing than wild-type mice during tests of conditioned fear expression-an effect that may be caused by a decrease in the consolidation of fear memory. These results suggest that central AT1a R activity in CRF-expressing cells plays a role in the expression of conditioned fear, and identify CRFergic cells as a population on which AT1 R antagonists may act to modulate fear extinction.

Fresh osteochondral allografts for treatment of articular defects in osteochondritis dissecans of the lateral femoral condyle in adults.

Fresh osteochondral allografts were used to patch defects in the lateral femoral condyle in 17 patients with osteochondritis dissecans. The patients included 12 males and five females, ages 16 to 46 years. All had previously undergone other procedures including pinning (4), primary removal of osteochondral fragments (16), and abrasion arthroplasty (14). Defects up to 3 cm in diameter were treated with isotopic grafts and fixed with Herbert screws. Larger defects were treated with crescent-shaped grafts fixed with multiple Herbert screws. Follow-up time ranged from two to nine years. Pain, stiffness, swelling, buckling, and locking were ablated in 16 of the 17 patients. No graft collapse has been noted in these individuals. Verification of graft viability was achieved at periods from six weeks to six years, typically at the time of hardware removal. The only failure occurred in an individual with a 3- x 4.5-cm defect who suffered gross fragmentation which left a large crater. Osteochondritis dissecans of the lateral femoral condyle provides an ideal opportunity for evaluating osteochondral grafts. Sixteen of 17 grafts were a success at two to nine years after surgery.

Osteochondritis dissecans of the lateral femoral condyle in the adult.

In osteochondritis dissecans, 15% of the lesions occur in the lateral condyle. In order to understand the significance of these lesions, 27 were studied prospectively from 1983 to 1990 and compared with 20 consecutive cases of lesions of the medial femoral condyle. Lesions of the lateral femoral condyle were larger, and often comprised the entire width of a condyle and resulted in deformation of a significant segment of the femoral condyle. They lay further posteriorly and commonly were associated with mechanical symptoms including buckling or locking. A discernible clunk was unique to these lesions. In addition, lateral lesions were more fragile, often having multiple bony islands that were prone to fragmentation, making replacement difficult if not impossible. Lateral lesions occurred directly within the main force-bearing areas of the condyle, disrupting normal contact areas and possibly leading to more rapid joint deterioration once segments are lost. This has prompted concern for reinsertion of articular fragments or reconstruction with osteochondral allografts.

Osteochondritis dissecans.

Osteochondritis dissecans is a rare orthopaedic disorder of unknown etiology. Advances in CT and MRI scanning have increased our knowledge of the disorder, but arthroscopy remains the principle means of monitoring its progress. Arthroscopic surgery has displaced traditional arthrotomy in many instances and is useful in retrieval of loose bodies, drilling of osteochondral fragments, retrograde bone grafting, and abrasion arthroplasty. Arthrotomy continues to be the best method of pinning and bone grafting of detached lesions. Advances in transplant surgery now permit large craters to be patched with osteochondral allografts.

Meniscal transplantation in the human knee: a preliminary report.

Meniscectomy can result in degenerative disease, with younger patients developing problems in middle age (1). In addition, loss of a major portion of a medical meniscus may increase instability in an anterior cruciate deficient knee (2). For these two reasons, it is theoretically desirable to transplant menisci in selected patients. In this paper, six patients who underwent allograft transplantation of a meniscus (four medial and two lateral) are presented to demonstrate the apparent success of the operative procedure. Follow-up extends from 24 to 44 months, June 1986 to March 1988. All patients are free of episodes of locking. Four have undergone arthroscopy, which demonstrated healing of the meniscus and no evidence of shrinkage. KT 1,000 values returned to normal in four cases, with concomitant reconstruction of the anterior cruciate ligament (ACL). It is hoped that meniscal transplantation will offset the development of degenerative changes; however, this supposition will remain unproven for decades. Meniscal transplantation seemed to improve stability in the knees undergoing ACL reconstruction. Arthroscopy performed after transplantation revealed that healing does indeed occur. There was no evidence of rejection, confirming the feeling that meniscal tissue is "immunologically privileged." Meniscal transplantation is offered as an adjunct to other reconstructive procedures in cases of meniscal deficient knees.

A directed approach to MRI of the athletic knee.

Surface coil MRI is now frequently utilized to assess acutely injured knees. In dedicated athletes, unique considerations exist which modify standard diagnosis and therapy. Concrete clinical findings must justify the potential loss of livelihood from even a "negative" arthroscopy. Seventeen injured athletes were evaluated by an orthopedic surgeon experienced in sports injuries and a preliminary localizing diagnosis was rendered, followed by knee MRI. Of 17 patients with significant injuries, MRI agreed with operative findings or clinical follow-up in 15 cases. Knee MRI prompted early intervention in those patients with conflicting subjective and/or objective findings. Furthermore, it helped direct the arthroscopist's surgical approach and encouraged close examination of areas less optimally visualized arthroscopically. MR and arthroscopy were complementary modalities in diagnosing certain ligamentous and cartilaginous lesions. MR effectively evaluated the cruciate ligaments often difficult to visualize by arthroscopy; arthroscopy better assessed articular surfaces. A cooperative effort existed between orthopedic surgeon and radiologist in directing both the MR study and arthroscopy. This was of particular benefit in maximizing scan efficiency in these large individuals who often filled the gantry. The team directed approach between orthopedic surgeon and radiologist affords deliberate and efficient diagnosis and therapy in this select population.

Pupillometric assessment of arousal to sexual stimuli: novelty effects or preference?

The pupillary response of male and female subjects to various sexual stimuli was examined. Change in pupil size was compared using light and dark control slides and nude male and female, heterosexual, and homosexual stimulus slides. Attempts were made to control for the many confounds inherent in pupillometric research. Pupil size was measured using video-recording techniques that magnified pupils to an easily measured size. Greater pupil change was found when the stimulus slide was preceded by a relatively lighter control slide. In addition, pupil change was related to familiarity with the stimulus slide and the relative pupil response changed as subjects gained experience with the stimulus material. Explanations and implications for further research are discussed.

Treatment of osteochondral defects of the distal femur with fresh osteochondral allografts: a preliminary report.

Twenty-four patients with osteochondral defects of a femoral condyle who failed to respond adequately to arthroscopic arthroplasty underwent osteochondral grafting with fresh allografts. Grafts were obtained from young donors and were matched according to skeletal size as measured by standard x-rays. Transplantation was performed within 12 h of harvesting. Follow-up extends from 2 to 4 years in 10 cases and is 1-2 years in the remaining 14. All ten patients with follow-up greater than 2 years were improved when evaluated in terms of pain, buckling, and swelling. Of the 24 patients, 11 have been evaluated arthroscopically following transplantation. In all 11 cases, the graft appeared viable. Fraying, if present, was limited to the margins of the graft in all except two cases. Collapse was not observed.

Temporomandibular joint disfunction syndrome and myofascial pain dysfunction syndrome: a critical review.

Temporomandibular joint (TMJ) dysfunction syndrome and myofascial pain dysfunction (MPD) syndrome have been primarily viewed as dental problems and have only recently received close attention by psychologists. The literature reviewed in the present paper reveals that a substantial portion of the population is affected by these disorders. There is, however, a great deal of confusion that exists in relation to the aetiology and treatment of these syndromes. In an attempt to clarify the current understanding of these disorders, the present review first presents a discussion of the symptoms which comprise each of these syndromes and the proposed physiological mechanisms associated with each symptom. Next, the aetiological theories for each of these syndromes are reviewed and critically evaluated. Treatments which have been derived from the theoretical models are then discussed. Finally, methodological considerations involving classification, assessment and treatment issues are presented and future research needs are outlined.

Assessment and treatment of stress in myofascial pain-dysfunction syndrome: a model for analysis.

Myofascial pain dysfunction (MPD) syndrome has received widespread attention in the dental and psychological literature. The present paper considers issues concerning a stress-related muscular hyperactivity theory of MPD syndrome. A review of the empirical evidence as well as methodological problems evident in these studies has been noted. In addition, definition aspects of stress and a conceptual model of stress in clinical use is presented. A functional analysis of the problem components will help determine a proper treatment protocol for patients suffering from stress-related myofascial pain. A discussion of the conceptual model for assessment and treatment purposes is presented and its implications for future research noted.

Free groin flap transfer to the upper extremity.

Seven patients underwent free groin flap transfer to the first web space, palm, wrist or elbow. Six of the seven were successful. The seventh developed acute venous occlusion and superficial necrosis of part of the flap, receiving split thickness skin grafts to salvage the dermal portion. Transfer is offered as an alternative to more conventional flaps for coverage of defects of the upper extremity.