The caudal neurosecretory system of Poecilia sphenops (molly) is an isolated population of neurosecretory cells located in the caudal most aspect of the teleost spinal cord. The structure of this neuroendocrine system is favorable for studies on the synaptic control of neurosecretory mechanisms. Little is known about the detailed synaptology of the system. Morphological and electrophysiological reports have shown that the caudal neurosecretory system is linked to higher brain centers by descending spinal projections. To examine the synaptology of the descending synaptic input, surgical deafferentation was performed by microsuction removal of a segment of spinal cord rostral to the caudal system. The degeneration of axon terminals was studied at various times following deafferentation and compared to control synaptology. Based on vesicle content and morphology, three axon terminal types were found in the caudal neurosecretory system. These terminals formed axosomatic, axodendritic, and axoaxonic synaptic contacts. Following deafferentation, axon terminals with dense-cored vesicles and boutons with round clear vesicles degenerated as evidenced by the electron dense dark reaction and the electron lucent reaction respectively. This suggested that at least two different types of axon terminals arise from the descending projection to the caudal neurosecretory system and that two different neurotransmitters may be influencing the neurosecretory activity of these cells.

Animals↗

PubMed1983

The iliac crest syndrome. A treatable cause of low-back pain.

Explore the source record for details and available documents.

Adult↗

PubMed1983

The load bearing capacity of vertebral cancellous bone in interbody fusion of the lumbar spine.

Explore the source record for details and available documents.

Biomechanical Phenomena↗

PubMed1983

Malpractice liability continues to expand.

Increasingly, the courts are holding hospitals liable for medical malpractice, especially in cases involving either physician-hospital contractual arrangements or selection and review of hospital medical staff.

Hospitals↗

PubMed1983

Contract management: legal issues in delegation and supervision.

Whatever the justification, the decision of a hospital board to enter into a management agreement is a significant one not to be undertaken without careful deliberation. An important component in that decision is consideration of the managerial functions to be delegated, and this process raises potential legal issues for the hospital trustee. This article examines those issues, identifies questions that a hospital board should address, and suggests some steps that trustees can take to minimize problems.

Contract Services↗

PubMed1983

The role of fusion for chronic low back pain.

The demonstration of a rich nerve supply in the outer half of the disc and the occurrence of deep pain referred from the vertebral column to the leg without nerve root compression are both important aspects in understanding low back pain and in making a decision regarding its surgical management. Discography is invaluable as a diagnostic test in patients with chronic back pain if one is to demonstrate discogenic lesions. For sufferers of postlaminectomy syndrome, a difficult patient group, a simultaneous combined anterior and posterior fusion offers a real hope for relief of pain and rehabilitation.

Adult↗

PubMed1983

Disseminated gonococcal infection: a prospective analysis of 49 patients and a review of pathophysiology and immune mechanisms.

Forty-nine patients with disseminated gonococcal infection (DGI) hospitalized at Boston City and University Hospitals over a 7-year period were studied. Patients with clinical manifestations of DGI and with cervical, urethral, rectal, pharyngeal, synovial or blood cultures positive for Neisseria gonorrhoeae were separated into two groups based on the presence or absence of suppurative arthritis. There were 19 cases of suppurative arthritis (Group II) and 30 cases with only tenosynovitis, skin lesions, or both (Group I). Blood cultures were positive only in Group I patients (43%) and synovial fluid cultures only in Group II patients (47%). Polyarthralgia was the most common initial symptom in both groups of patients. Twenty-six Group I patients had tenosynovitis (87%), while only 4 Group II patients (21%) had tenosynovitis (p less than 0.001). The knee was the most commonly involved suppurated joint. Twenty-seven Group I patients (90%) had skin lesions compared to 8 Group II patients (42%) (p less than 0.001). Some of these lesions progressed on treatment; some patients were unaware of their lesions. Genitourinary symptoms were unusual in both groups of patients. Eleven women (33%) were menstruating or were pregnant at the onset of DGI. Thirteen patients had histories suggestive of previous gonococcal infections; one had recurrent DGI. This patient and one other were found to have complement abnormalities. There were no cases of endocarditis or meningitis. Four patients had unexplained liver function abnormalities. All patients recovered uneventfully. Strains isolated from disseminated sites were predominantly of the transparent phenotype (90%). Many strains (58%) required arginine, hypoxanthine and uracil for growth. They were also more susceptible to penicillin than reported strains that cause pelvic inflammatory disease. Most strains were of a single outer membrane protein coagglutination serogroup, WI (85%). These characteristics did not vary between the Group I and Group II isolates. The two groups of strains, however, did vary in their complement-dependent bactericidal reactivity to normal human sera. Eighteen of 24 Group I strains (75%) versus 9 of 19 Group II strains (47%) resisted killing by all normal human sera tested (p less than .05). Likewise, convalescent sera from Group II patients were able to kill their infecting strains more often than did sera from Group I patients (70% vs 17%) (p less than 0.01). Thus, variations in the clinical expression of disease in patients with DGI may be explained, in part, by differences in certain phenotypic and immunologic features of infecting strains.

Arthritis, Infectious↗

PubMed1982