Use of the activated clotting time in anticoagulation monitoring of intravascular procedures

The activated clotting time first came into clinical use in the mid-1970s to guide the administration and reversal of heparin during cardiopulmonary bypass procedures. The explosive growth of cardiopulmonary bypass led to the development of automated techniques for measuring activated clotting times. Recent advances in the field of interventional cardiology have emphasized the importance of the coagulation cascade and the need for the prevention of thrombosis with anticoagulant drugs. The activated clotting time has emerged as an important means of monitoring and guiding heparin therapy during invasive intravascular procedures. This review focuses on the following topics: 1) the development of anticoagulation monitoring techniques; 2) current alternatives in bedside anticoagulation monitoring; and 3) the clinical application of activated clotting times outside surgery. Until prospective studies can establish appropriate "target" activated-clotting-time values for interventional procedures, procedural anticoagulation must be guided empirically. Nevertheless, the activated clotting time is extremely useful in the catheterization laboratory, for monitoring heparin therapy and the adequacy of anticoagulation.

Three-dimensional reconstruction of skeletal muscle from MRI

Three-dimensional (3D) reconstructions of medical images can provide useful information to the radiologist, enabling delineation and spatial correlation of anatomic structures in one image rather than consecutive two-dimensional (2D) images. Magnetic resonance imaging (MRI) is known to be a powerful technique for evaluation of skeletal muscle pathology and physiology. We investigated the role of 3D reconstruction from MRI images of pathological and healthy muscle, using volume rendering. The ability to easily delineate and recognize normal and injured muscle in the 3D images were dependent upon the original contrast between normal and injured muscle, spatial resolution, and anatomic complexity in the original slices, and also on imaging parameters such as volume averaging.

General practitioners' reported knowledge about depression and dementia in elderly patients

Previous studies have shown that general practitioners often fail to detect dementia and depression in their elderly patients. The present study aimed to find out how much knowledge general practitioners have of these disorders. The knowledge of 36 general practitioners was assessed and it was found that they had a limited knowledge of the symptoms and signs of dementia and depression. Furthermore, almost 60% of the general practitioners did not know that Alzheimer's disease is the most common dementing disorder.

General practitioners' detection of depression and dementia in elderly patients

In a study of 11 general practitioners' detection of dementia and depression in 101 elderly patients it was found that general practitioners were more accurate in their detection of dementia than depression. The general practitioners did not identify 12 of the 15 patients assessed as depressed by a Diagnostic Interview for Depression, but their assessments of dementia corresponded quite well with the results of dementia tests. The general practitioners' knowledge of the symptoms and signs of dementia and depression was limited. If the patient talked to the general practitioner about feeling depressed, sad or irritable, the depression recognition rate increased.

Effect of ranitidine on gastroduodenal mucosal damage induced by nonsteroidal antiinflammatory drugs

The effect of ranitidine in preventing mucosal damage caused by nonsteroidal antiinflammatory drugs (NSAIDs) was evaluated for eight weeks in a prospective study of 144 patients requiring NSAIDs. Patients with normal endoscopic findings were randomly assigned to receive either ranitidine 150 mg twice daily or placebo for eight weeks, along with either ibuprofen, indomethacin, naproxen, sulindac, or piroxicam. Duodenal damage was significantly less in the ranitidine group compared with the placebo group by weeks 4 and 8 (P less than or equal to 0.01). Duodenal ulcers did not develop in any patients on ranitidine (0/57) compared with 4/49 patients (8%) on placebo (P = 0.02). No significant difference was found between treatment groups with respect to gastric damage; 6/60 (10%) in the ranitidine group compared with 6/50 (12%) in the placebo group developed gastric ulcers. These findings suggest that acid suppression is of greater importance for mucosal protection in the duodenum than in the stomach, where other defense mechanisms may be operative. While ranitidine is an effective prophylaxis for NSAID-induced damage in the duodenum, further studies are needed to define specific risk groups and to assess the potential usefulness of more complete acid suppression in preventing gastric mucosal damage.

The ovulated ovum of the horse: cytology of nonfertilized ova to pronuclear stage ova

Fertilization and early development in the horse were studied by recovering oviductal ova at various times after postovulatory mating. Ova collected between 7 and 22 h post coitum (pc) were examined for evidence of fertilizing sperm, cellular changes accompanying fertilization, and pronuclear development. Five ova collected between 7 and 9 h pc contained a marginal metaphase plate, but had no indication of sperm components; three of these, however, showed reduced numbers of cortical granules. Two activated ova (10 and 14 h pc) were in telophase of the second meiotic division, following incorporation of the fertilizing sperm. The fertilizing sperm was situated in a slight elevation; the nucleus was expanding but lacked a nuclear envelope. The pronuclear stage in the horse began as early as 12 h pc, and lasted at least until 21 h pc. Sperm tail remnants were seen in 5 of 7 pronuclear-stage ova, although the crowding of the cytoplasm with clusters of lipid and vacuoles made discerning sperm tail remnants difficult. The spindles of the metaphase stage of the second meiotic division were oriented radially, that is, at right angles to the cell surface, in all but one ovum, so this orientation is not a response to fertilization.

An acoustic-speech study of patients who received orthognathic surgery

Several reports have suggested that orthognathic surgery may influence speech patterns. The purpose of this study was to examine the formant frequency changes of speech following orthognathic surgery in patients whose speech was considered perceptually normal preoperatively and postoperatively. Speech samples were obtained from five patients (three patients with Class II, Division 1 malocclusions and two patients with Class III malocclusions). Significant second-formant frequency shifts were found for the vowel 'e' (as in 'seat'); however, only minor second-formant frequency variations were found for the vowels 'a' (as in 'sat') and 'u' (as in 'suit'). The pattern of formant frequencies before and after surgical treatment suggested that the speakers adjusted their articulation to accommodate the orthognathic surgery. Overall, the data from this study indicate that speech patterns may be reorganized after orthognathic surgery even though speech remains perceptually "normal."

Binaural phase differences and binaural auditory adaptation

In order to determine the relationship between binaural phase localization and auditory adaptation, subjects were asked to perform a series of phase-based localization tasks, as well as an SDLB adaptation task. A binaurally presented 400 Hz tone was used for midplane localization tasks, and adaptation balances. The tone was presented monaurally during adaptation after binaural localization and the SDLB pre-test. Following 7 min exposure, subjects readjusted phase to centre the binaural stimulus in the midline, and then adjusted intensity to determine dB of adaptation. No consistent or statistically significant change in phase settings occurred. There was a significant decline in the balance intensity as a function of adaptation. A further re-establishment of the midline by phase manipulation also showed no localization effect. For the stimulus values used in the present study, there was no inter-effect of binaural phase localization, and SDLB auditory adaptation.

Prophylaxis of upper gastrointestinal hemorrhage in patients requiring mechanical ventilation

Because approximately 20% of patients receiving mechanical ventilation have upper gastrointestinal bleeding, these patients were prophylatically treated with either antacids, cimetidine, or a placebo in a double-blind randomized fashion. The authors did not titrate gastric acidity because it is a time-consuming process that requires a nasogastric tube. When gastrointestinal bleeding developed in 9 of the 36 patients entered in the study, the treatment code was broken to assess the efficacy of prophylaxis and the frequency of complications. In the antacid group, 5 of the 11 patients were unable to ingest and tolerate their antacids (p less than 0.05 when compared to the control and cimetidine groups). Gastrointestinal bleeding did not occur in any of the six subjects receiving antacids but did occur in one of the 11 subjects receiving cimetidine, in 5 of the 14 control patients, and in 3 of the 5 patients who were unable to tolerate antacids. These differences were not significant. When groups were rearranged, though, there was a significant difference between them. Only 1 of 17 patients receiving medication (antacids or cimetidine) bled, whereas 8 of 19 patients receiving no medications bled (p less than 0.01). The average number of risk factors was not significantly different in the treatment groups. The authors conclude that prophylactic therapy (cimetidine or antacids) given without titration is associated with a lower frequency of upper gastrointestinal hemorrhage than when no medication is given. The authors also conclude that more subjects are able to tolerate cimetidine than antacids.

Rupture of a splenic artery aneurysm into the pancreatic duct

A patient with hemorrhage into the pancreatic duct from a splenic artery aneurysm is presented. The angiographic, retrograde pancreatographic, and pathological findings are demonstrated. The diagnosis was established by demonstrating an enlarging aneurysm by serial angiograms. The location of the splenic artery aneurysm was confirmed by retrograde pancreatography before surgery. The distal pancreas containing the aneurysm was resected.

Electroimmunoquantitation of serum proteins cross-linked by glutaraldehyde

Electroimmunoassay is a simple, rapid and accurate method for quantitating the serum proteins. By use of glutaraldehyde, intermolecular cross-linkage of immunoglobulins to albumin was effected. The conjugation resulted in increased electrophoretic mobility of the immunoglobulins without perceptible change in antigenic determinants. With a Tris-EDTA-boric acid buffer system, the cross-linked immunoglobulins migrated anodically in an electrical field. Six serum proteins from each of 20 samples were quantitated by electroimmunoassay, and the results correlated with values obtained by radial immunodiffusion.