The mandibular canal of the edentulous jaw.

The morphology of the mandibular canal after loss of teeth has received little detailed attention. Improved documentation of this topic would allow better interpretation of dental radiographs and would enable those engaged in tooth implantation to better understand the nature of the tissue into which the prostheses are placed. In this study on mandibles from seven dissecting room cadavers panoramic radiographs usually showed the mandibular canal clearly, an incisive canal less so. The wall of the mandibular canal was similar in dentate and edentulous mandibles, and was highly perforated, as suggested by Cryer (Anderson et al., 1991). In edentulous specimens, it was composed mainly of cancellous bone with only occasional single osteons. The inferior alveolar nerve near the mandibular foramen was a large trunk, consisting of three to four nerve bundles with connective tissue sheaths. It became more loosely arranged toward the mental foramen. Medial to the mental foramen, the nerves were frequently in the form of small bundles in the marrow. Any incisive canal was ill-defined and neurovascular bundles, when present, ran through a labyrinth of intertrabecular spaces.     

An anatomic study of local infiltration analgesia in total knee arthroplasty

BackgroundLocal infiltration analgesia (LIA) is a relatively novel technique developed for effective pain control following total knee arthroplasty (TKA), reducing requirements for epidural or parenteral postoperative analgesia. This study investigated the anatomical spread of an LIA used in TKA to identify the nerve structures reached by the injected fluid.MethodsSix fresh-frozen cadaveric lower limbs were injected according to a standardised LIA technique with a solution of latex and India ink to enable visualisation. Wounds were closed and limbs placed flat in a freezer at ? 20 °C for two weeks. Limbs were then either sliced or dissected to identify solution locations.ResultsSolution was found from the proximal thigh to the middle of the lower leg. The main areas of concentration were the popliteal fossa, the anterior aspect of the femur and the subcutaneous tissue of the anterior aspect of the knee. There was less solution in the lower popliteal fossa. The solution was found to reach the majority of nerves, with good infiltration of nerves supplying the knee.ConclusionsThese results support the positive clinical outcomes with this LIA technique. However, the lack of infiltration into the lower popliteal fossa suggests more fluid or a different injection point could be used. The solution reaching the extensor muscles of the lower leg is likely to have no beneficial analgesic effect for a TKA patient. The LIA technique is already used in clinical practice following total knee arthroplasty. Results from this study show there may be scope to optimise the injection sites in LIA technique.     

High Throughput Fingerprint Analysis of Large-Insert Clones

As part of the Human Genome Project, the Washington University Genome Sequencing Center has commenced systematic sequencing of human chromsome 7. To organize and supply the effort, we have undertaken the construction of sequence-ready physical maps for defined chromosomal intervals. Map construction is a serial process composed of three main activities. First, candidate STS-positive large-insert PAC and BAC clones are identified. Next, these candidate clones are subjected to fingerprint analysis. Finally, the fingerprint data are used to assemble sequence-ready maps. The fingerprinting method we have devised is key to the success of the overall approach. We present here the details of the method and show that the fingerprints are of sufficient quality to permit the construction of megabase-size contigs in defined regions of the human genome. We anticipate that the high throughput and precision characteristic of our fingerprinting method will make it of general utility.     

Comparing longitudinal patient-reported outcome measures between Swedish patients with recent-onset systemic lupus erythematosus and early rheumatoid arthritis

Clinical Rheumatology - The onset of rheumatic disease affects each patient differently and may impact quality of life with progression. We investigated the relationship between patient-reported...     

Vanadate stimulation of adenylyl cyclase: an index of tyrosine kinase vascular effects.

BACKGROUND: Beyond their mitogenic effects, hormones such as insulin, which activate receptor tyrosine kinases, regulate vascular tone. Further, we have demonstrated that receptor tyrosine kinase activation enhances adenylyl cyclase activation, a prominent mechanism that mediates vasodilation. However, whether tyrosine kinase-mediated human vascular responses parallel tyrosine kinase-mediated cellular effects on adenylyl cyclase activity is unknown. METHODS AND RESULTS: To assess tyrosine kinase-mediated vascular responses, vascular sensitivity to insulin was assessed with the dorsal hand vein linear variable differential transformer technique. Insulin infusion resulted in a dose-dependent relaxation in all subjects. Cellular responses were assessed by means of the insulinomimetic vanadate-mediated sensitization of vascular adenylyl cyclase activity. Vanadate stimulated a tyrosine kinase-dependent enhancement of adenylyl cyclase function in human and rat aortic vascular smooth muscle cells, human lymphocytes, and human aortic endothelial cells. Further, maximal insulin-mediated vasodilation was significantly positively correlated with maximal vanadate-mediated enhancement of human lymphocyte adenylyl cyclase activity. CONCLUSION: Insulin-mediated vasodilation is positively correlated with vanadate-mediated enhancement of adenylyl cyclase activity. Vanadate-mediated enhancement of adenylyl cyclase activity in lymphocytes may represent an index of tyrosine kinase-mediated vascular effects.