Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Influence of complement on sperm motility

Isolated sperm from normo-, oligo- and astheno-spermic men were incubated for 20 h in medium supplemented with 8% heat-inactivated or untreated human serum, and in medium with heated or untreated serum deficient in complement factor C3. Before and after incubation, sperm motility was assessed by means of a computer-assisted semen analyser. The results did not show significant differences between the motility of sperm incubated in heated or untreated serum. It is concluded that heating of homologous serum is not necessary for preserving sperm motility and in some cases may even be disadvantageous.     

Detection of foot-and-mouth disease virus-infected cattle by assessment of antibody response in oropharyngeal fluids.

The detection of foot-and-mouth disease virus (FMDV)-persistent carriers among convalescent ruminants is of paramount importance in the aftermath of a field outbreak. To this purpose, FMDV-specific antibody should be investigated first, since virus isolation procedures from such carriers are seriously constrained. The complexity of the overall picture may be compounded by possible emergency vaccinations in the affected areas at the beginning of the outbreak. In this case, it is suggested that mucosal rather than serum antibody be investigated. In fact, we showed that FMDV-infected cattle regularly mount an antibody response in oropharyngeal fluids, in contrast to vaccinated cattle. Antibody could be revealed by neutralization assays and/or an immunoglobulin A (IgA)-specific kinetic enzyme-linked immunosorbent assay (ELISA). Cattle vaccinated once seldom showed a mucosal antibody response, which could be only detected by a total immunoglobulin-specific kinetic ELISA. Very few, if any, cattle showed a mucosal IgA response after repeated vaccinations. Our kinetic, IgA-specific ELISA generally allowed an early detection of FMDV-infected cattle; in particular, it proved to be more sensitive than the usual indirect, antigen-trapping ELISA in experiments on saliva samples.     

Image-directed percutaneous biopsies with a biopsy gun

Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method.     

Kainate receptor (GluR5)-mediated disinhibition of responses in rat ventrobasal thalamus allows a novel sensory processing mechanism

Kainate receptors have been studied extensively in vitro , but how they might function physiologically remains unclear. We studied kainate receptor modulation of synaptic responses in the rat ventrobasal thalamus using the novel antagonist LY382884 and the agonist ATPA (selective for GluR5-containing kainate receptors) as tools. No evidence could be found for a direct contribution of kainate receptors to responses of thalamic relay cells to lemniscal (sensory) input in thalamic slices studied with the aid of intracellular and field potential recordings, using selective AMPA and NMDA receptor antagonists and LY382884. However, the GluR5 agonist ATPA reduced the IPSPs originating from the thalamic reticular nucleus. Extracellular single-neurone recordings in anaesthetised rats showed that excitatory responses evoked by physiological vibrissa afferent stimulation were reduced by LY382884 applied iontophoretically at the recording site. This action of the antagonist was occluded when GABA receptors were blocked, indicating that the reduction in excitatory sensory responses by LY382884 is due to an action on GABAergic inhibition arising from the thalamic reticular nucleus. Further experiments showed that these actions depended on whether inhibition was evoked during activation of the excitatory receptive field rather than when inhibition was evoked from a surround vibrissa. We suggest that GluR5 is located presynaptically on inhibitory GABAergic terminals of thalamic reticular nucleus neurones, and that it is normally activated by glutamate spillover from synapses between excitatory afferents and relay neurones during physiological stimulation. We propose that this GluR5-activated disinhibition has an important novel role in extracting sensory information from background noise.     

Actions of microiontophoretically applied oxytocin, and immunohistochemical localization of oxytocin, vasopressin and neurophysin in the rat caudal medulla

Oxytocin-, vasopressin- and neurophysin-containing axons were visualized within the rat caudal medulla using the immunoperoxidase technique. The highest densities of axons and terminals were found in the nucleus tractus solitarius, nucleus dorsalis vagus, nucleus commissuralis, nucleus reticularis lateralis and within the marginal layer of the nucleus trigeminalis. In these areas, oxytocin fibres predominated markedly over vasopressin fibres. In a series of electrophysiological experiments, neurones in these and surrounding areas were predominantly depressed following the iontophoretic application of oxytocin. This depression was seen on both spontaneous and glutamate-evoked neuronal firing.