Accurately evaluating for a small bowel obstruction using an abdominal radiograph, by a new method: The Bowel-Spine Ratio.

INTRODUCTION: A well-established method does not exist to rule out a small bowel obstruction using an abdominal xray series with significant accuracy. The hypothesis of the study is that the ratio of an average small bowel diameter to lumbar spine diameter over 0.5 is most likely a small bowel obstruction. METHODS: An x-ray abdominal series measurement technique was applied to 41 subjects with a chief complaint of "abdominal pain" as part of a randomized retrospective case review to predict an obstruction v. non obstruction. A total number of 81 abdominal pain subjects with a mean age of 46.7 years were selected with 40 excluded due to normal small bowel gas pattern. The subject's medical information was unknown to the authors when reading their images. The measurement technique involved averaging the largest and smallest small bowel short axis diameters with comparison to the lowest clearly visible lumbar body width. The subjects' medical course as described in the medical chart or subsequent computed tomography scans were used as the referencing standard to determine presence of obstruction vs non-obstruction. RESULTS: This method, called the Bowel-Spine Ratio (BSR), resulted in a sensitivity of 0.882 (0.622-0.979; 95% CI), specificity of 0.957 (0.760-0.998; 95% CI), accuracy of 94.7% (80.9%-99.1%; 95% CI) and a positive likelihood ratio of 21 for predicting a small bowel obstruction. CONCLUSION: The abdominal series Bowel-Spine Ratio is a simple yet effective technique to screen for a small bowel obstruction using limited resources and to avoid unnecessary computed tomography scans with the potential to reduce health care costs. IMPLICATIONS FOR PRACTICE: Clinicians could have increased confidence in utilizing abdominal radiographs to evaluate for small bowel obstruction.

The role of nitric oxide in development of topographic precision in the retinotectal projection of chick.

The axonal projection from the retina to the tectum exhibits a precise topographic order in the mature chick such that neighboring ganglion cells send axons to neighboring termination zones in the contralateral tectum. The initial pattern formed during development is much less organized and is refined to the adult pattern during a discrete period of development. Refinement includes elimination of radically aberrant projections, such as those from the temporal side of the retina to posterior regions of the tectum, as well as a more subtle improvement in the topographic precision of the projection. The enzyme that synthesizes nitric oxide is expressed at high levels in the tectum during the developmental period in which the topography improves. Pharmacological blockade of nitric oxide synthesis during this period prevented elimination of topographically inappropriate retinotectal projections in a dose-dependent manner. This effect could not be duplicated by treatment of embryos with a vasoconstrictor, indicating that vascular changes were not a factor. These results show that nitric oxide is involved in refinement of the topography of the retinotectal projection as well as in other aspects of refinement of this projection in developing chick.

Preliminary evidence: decreased GAP-43 message in tangle-bearing neurons relative to adjacent tangle-free neurons in Alzheimer's disease parahippocampal gyrus.

Loss of synapses has been shown to correlate with the severity of dementia in Alzheimer's disease (AD). Intracellular neurofibrillary tangles (NFTs) have also been shown to correlate to the severity of AD dementia. We have been investigating the influence of NFTs on mRNAs related to neuronal plasticity and synaptic function. We recently reported a decrease in message for the plasticity marker, GAP-43, in AD cases with high tangle densities. The study did not permit us to determine if: a) the decrease in GAP-43 message was specific to the NFT-bearing neurons, b) a general decrease in GAP-43 message was occurring in all surviving neurons, or c) the decrease in GAP-43 message was due to a loss of neurons. It is unlikely a loss of neurons could explain the sixfold GAP-43 message loss we reported, because only a 19% excess decrease in density of hippocampal neurons occurs in AD cases with high tangle densities. Consequently, the study reported here was undertaken to determine if a general decrease in GAP-43 message was occurring in all surviving AD neurons or if the decrease in GAP-43 message was specific to NFT-bearing neurons. We combined immunocytochemistry for neurofibrillary tangles with in situ hybridization for GAP-43 message. We report here preliminary evidence indicating a decrease in GAP-43 message in NFT-bearing neurons compared to adjacent nontangle bearing neurons in parahippocampal cortex of AD patients.

The human brain homeogene, DLX-2: cDNA sequence and alignment with the murine homologue.

A novel homeobox-containing cDNA from the developing human brain has been cloned and sequenced. The transcript is most closely related to the Distal-less (Dll) homeogene of Drosophila melanogaster and to the Dlx genes in the mouse, specifically to Dlx-2. As such, it is the first report of a human Dll-like gene.

The amino terminus of the putative Drosophila choline acetyltransferase precursor is cleaved to yield the 67 kDa enzyme.

A putative precursor of the 67 kDa choline acetyltransferase (Acetyl-CoA: choline-O-acetyltransferase; EC 2.3.1.6) polypeptide from Drosophila was examined using polyclonal antibodies. The central purpose of the study was to probe the suspected precursor with anti-peptide antibodies that could identify a cleavable amino terminal domain, since such a structure could be responsible for targeting the enzyme to the presynaptic terminal. Antisera were produced to both a plasmid-expressed fusion-free enzyme protein and a 26-amino acid-long peptide reproducing sequence from the enzyme. Both antisera were capable of precipitating enzyme activity from crude supernatants. Western blotting with the antibody to the plasmid-expressed enzyme visualized a major polypeptide at 75 kDa and minor polypeptides at 67 and 54 kDa. Affinity-purified IgG to the synthetic peptide only recognized the 75 kDa component and was unable to recognize purified 67 kDa enzyme protein. Timed autolysis of the enzyme in crude homogenates demonstrated both a 67 kDa polypeptide that was present prior to homogenization and a species that appeared as a product of the autolysis. The evidence from this study is consistent with the expectation that the 75 kDa band, visualized on Western blots with antisera to the enzyme, is an authentic enzyme protein. These data further suggested that the 75 kDa protein is an amino-terminally extended precursor of the 67 kDa enzyme that can be cleaved to generate the 67 kDa species.