Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

Identification of an insulin-like factor in astrocyte conditioned medium

Survival of dissociated 19-day fetal rat telencephalic neurons in a hormone-free defined medium required the addition of insulin at pharmacological concentrations. However, survival of astrocytes cultured from the cerebral cortex of newborn rats in the same medium did not require insulin. When fetal neurons were incubated with astrocyte conditioned medium or plated on a monolayer of astrocytes, their survival was significantly increased in the absence of insulin. This effect of astrocyte conditioned medium was visibly inhibited by affinity chromatography on an anti-insulin protein A agarose column. A 5-30 kDa ultrafiltration fraction of astrocyte conditioned medium also increased neuronal survival. In addition, the 5-30 kDa fraction stimulated [3H]leucine incorporation into the TCA insoluble material from cultured neurons and competed for [125I]insulin binding to intact neuronal cultures. These results indicate that cultured astrocytes produce a factor with biological and immunological properties similar to those of insulin. This factor may in part mediate the observed neurotrophic effects of astrocyte conditioned medium and may play a role in the normal development and differentiation of central nervous system neurons.     

Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.      

Radiology information systems,picture archiving and communication systems,teleradiology— Overview and design criteria

Information technology (IT), long taken for granted in commercial settings, is now being utilized for healthcare applications. Medical imaging has lagged comparatively due to the extremely vast data content of each frame; thus, the requirement for expensive high-end components. Further, IT in radiology has evolved from two distinctly separate camps—information systems, known as RIS (radiology information systems) and PACS (picture archiving and communications systems). Both RIS and PACS applications have migrated to the PC environment, enabling cost-effective implementation, but from two backgrounds: RIS from vendors using conventional information systems platforms and products, and PACS from radiographic film and modality vendors. The radiology department at Texas Tech University has assembled a seamlessly integrated, enterprise-wide RIS/PACS/teleradiology intranet. The design criteria include user-friendliness, flexibility to respond to changing needs, and open modular architecture to assure interoperability, cost-effectiveness, and future-proofing of investment. Since no single venor could provide an integrated system meeting our specifications, we decided to assume the burden of constructing our own system. As the system integrator, we embrace open architecture, thus enabling the incorporation of industry-standard-compliant, COTS (commercially off the shelf) products as modules. Microsoft Windows NT operating system, Visual C++ programming language, TCP/IP (transmission control protocol/internetworking protocol), relational SQL (structured query language) database, ODBC (open database connectivity), HL-7 (health level seven) and DICOM (digital imaging and communications in medicine) interfaces are utilized. The usage of COTS components reduces the cost to very affordable levels. With this approach, any module in our system can be replaced when outmoded, without affecting other modules in our system, making it truly future-proof. Construction and evolution of our system (TECHRAD) is reviewed.     

Cell-mediated immune response to products of Actinomyces viscosus cultures.

Hartley strain guinea pigs were sensitized with 0.5 ml of concentrated cell-free Actinomyces viscosus culture supernatant fluids mixed with Freund complete adjuvant. Fourteen to 16 days later the animals were challenged by intradermal injection with 0.1 ml of the culture supernatant, and the reactions were observed at 4, 8, 16, 24, and 48 h. Peritoneal exudate cells from sensitized animals were used for determination of migration inhibition factor, and guinea pig peripheral blood served as a source of cells for determining the induction of mitogenesis by antigenic material. Skin responses were consistently positive to challenge with the test material, whereas reactions to noninoculated culture medium were negative. Sensitized cells, challenged with antigen, resulted in 60% or greater inhibition of migration of indicator cells in migration inhibition factor experiments. Tests for mitogenesis showed a greater than fourfold increase in isotope uptake when sensitized cells were challenged with test material. The data are consistent with the suggestion that A. viscosus culture supernatants contain substances that induce cell-mediated immune responses in guinea pigs.     

The inferior alveolar artery in its bony course

Based on the dissection of 30 hemi-mandibles, the authors report a study of the inferior alveolar artery in its intraosseous course. On morphologic considerations they propose a classification of the collaterals into two groups: the principal collaterals destined for the teeth and the bony alveolar tissue and the secondary collaterals destined for the sheath and the nerve as well as the bony tissue around the canal. Loss of the teeth and absorption of the alveolar bone modify the caliber of the inferior alveolar arterial axis, the distribution of its collaterals and possibly its mode of termination. These facts suggest a consideration of the vascularization of the mandible in terms of four sectors. They arrive at practical conclusions that may be drawn from this study in stomatology.