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Biomedical subjects

J Bowers

Publications and source records attributed to J Bowers.

52 records · Page 3Linked to original sources
PubMed1982

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.

Antacids↗
PubMed1976

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.

Aneurysm↗
PubMed1975

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.

Aldehydes↗
PubMedDate not supplied

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.

Algorithms↗
PubMedDate not supplied

An outbreak of plague including cases with probable pneumonic infection, Ecuador, 1998.

During February and March of 1998, 12 sudden deaths were reported among residents of a high-Andean community in Ecuador. All 12 fatalities were members of the same extended family and some had apparent exposure to sick guinea-pigs. Following an initial investigation by public health officials, an additional death was reported in a nearby community in April, also associated with exposure to sick guinea-pigs. Blood samples from humans, dogs, and a rodent were tested for antibody to the F1 antigen of Yersinia pestis by passive haemagglutination assay. Tissue from rodents was subjected to direct fluorescent antibody staining using fluorescein-labelled monoclonal antibody to Y. pestis F1 antigen. Formalin-fixed specimens from the 2 autopsies were evaluated using a 2-step alkaline phosphatase immunoassay with a monoclonal antibody to Y. pestis F1 antigen, and tissues that had not been embedded in paraffin were tested for the presence of DNA encoding the F1 structural antigen by polymerase chain reaction. Serological evaluation of close contacts of the fatalities revealed positive titres to F1 antigen of Y. pestis, the aetiological agent of plague, in 3 contacts from the first community and 1 from the second. Immunohistochemical staining of tissues collected from 2 of the fatalities provided evidence that both had pneumonic plague. Five of 14 dogs found in the communities were seropositive for plague antibody, providing evidence of a recent epizootic plague in the area.

Adolescent↗
PubMedDate not supplied

Interaction of saddle girth construction and tension on respiratory mechanics and gas exchange during supramaximal treadmill exercise in horses.

OBJECTIVE: To determine the effect of girth construction and tension on respiratory mechanics and gas exchange during supramaximal treadmill exercise in horses. METHODS: Six healthy detrained Thoroughbred horses were exercised on a treadmill inclined at 10% at 110% VO2max. Horses were instrumented for respiratory mechanics and gas exchange studies, and data were recorded during incremental exercise tests. The animals were exercised for 2 min at 40% VO2max, and samples and measurements were collected at 1 min 45 sec. After 2 min, speed was increased to that estimated at 110% VO2max and data was collected at 45 sec, 90 sec and every 30 sec thereafter at this speed until the horses fatigued. Horses were run on three occasions with the same racing saddle and saddle packing but using two different girths, either an elastic girth (EG) or a standard canvas girth (SCG) which is nonelastic. A run with 5 kg tension applied to a standard canvas girth was the control for each horse, with additional runs at 15 kg using either the standard canvas girth or using the elastic girth. The runs were randomised and tensions applied were measured at end exhalation whilst at rest. RESULTS: Increasing girth tension was not associated with changes in respiratory mechanical or gas exchange properties. Although girths tightened to 15 kg tension had short run to fatigue times this was not found to be significantly different to girths set at 5 kg resting tension. Girth tensions declined at end exhalation in horses nearing fatigue. CONCLUSIONS: Loss in performance associated with high girth tensions is not due to alteration of respiratory mechanics. Loss in performance may be related to inspiratory muscles working at suboptimal lengths due to thoracic compression or compression of musculature around the chest. However, these changes are not reflected in altered respiratory mechanical or gas exchange properties measured during tidal breathing during supramaximal exercise. Other factors may hasten the onset of fatigue when horses exercise with tight girths and further studies are required to determine why excessively tight girths affect performance.

Abdomen↗
PubMedDate not supplied

Comparison of girth materials, girth tensions and their effects on performance in racehorses.

OBJECTIVE: To compare the effect of girth materials and commonly used girth tensions on athletic performance of race-horses and to test the length tension properties of commercially available girths. PROCEDURE: Seven horses were exercised at speeds to produce 95% of maximal heart rates on 15 occasions using a randomised block design, and girthed with 5 different girths at 3 nominal tensions of 6, 12 or 18 kg. The girths used were a standard elastic race girth, an 'American' elastic race girth, an elastic race girth twice the normal width, a standard canvas race girth and a canvas race girth at twice the normal width. Tension in the girth was recorded continuously using an in-line load cell connected to a physiograph. Horses ran to fatigue on a treadmill inclined at 10% slope. Tensions were measured at peak inhalation (T/inh) and exhalation (T/exh), recorded at rest (rest) and during exercise (ex). An analysis of variance was used to compare the mean run to fatigue times (RTFT) between girth types and tensions, multiple pair-wise comparisons were then carried out using Tukey's test where significant differences were found. The length-tension relationships of five commercially available girths for training and racing of Thoroughbred racehorses were studied by the application of standardized weights in series to multiple samples of each type of girth. Measurements were taken in a controlled environment and analysis of variance was used to compare the means for length-tension of each girth type. RESULTS: The elastic and the 'American' elastic girths produced significantly longer RTFT when compared to the standard canvas girth (P = 0.01 and P = 0.001 respectively). Also girths tensioned at Texhrest 6 kg and Texhrest 12 kg produced significantly longer RTFT than when girthed at Texhrest 18 kg (P = 0.03 and P = 0.08 respectively). There were significant differences between the commercially available girth types at each tension (P < 0.05), but differences were not significant between girths of the same type. Girths with an elastic component reached their peak for maximum extension at 14.5 kg and thereafter their extension declined. CONCLUSION: The type of girth and the tension at which it is applied affects athletic performance. Lower girth tensions and the use of elastic materials in the girth would appear to optimise performance. However according to this study and our previous study, none of the commercially available girths studied would adequately protect against the potentially detrimental effects of overtightening on athletic performance.

Abdomen↗
PubMedDate not supplied

A double-blind, placebo-controlled trial of sustained-release diltiazem in patients with angina. Sustained-Release Diltiazem Study Group.

The efficacy of a new sustained-release formulation of diltiazem was examined in a placebo-controlled, double-blind trial in patients with stable angina. Doses of 60 mg BID, 90 mg BID, 180 mg BID and 240 mg BID were compared with placebo in 208 patients at 3 hours and 12 hours after dosing. Diltiazem, in doses of 90 mg BID and 180 mg BID, was statistically superior to placebo with respect to increasing total exercise time. Treadmill exercise time at 3 hours postdose increased with placebo from 356.1 +/- 118.7 sec to 375.7 +/- 119.8 sec (NS); with 90 mg BID, 382.7 +/- 111.8 sec to 445.4 +/- 117.5 sec (P < 0.005); and with 180 mg BID, 386.8 +/- 145.9 sec to 467.2 +/- 166.2 sec (P < 0.0001). At 12 hours postdose, treadmill exercise time with placebo increased from 357.6 +/- 128.3 sec to 383.8 +/- 128.7 sec (NS); with 90 mg BID, 395.2 +/- 119.4 sec to 449.7 +/- 123.1 sec (P = 0.053); with 180 mg BID, 395.3 +/- 141.4 sec to 476.6 +/- 165.6 sec (P < 0.0001). Time to onset of angina was also increased by the 180-mg-BID dose both at 3 hours postdose (257.3 +/- 126.8 sec to 354.3 +/- 158.7 sec; P < 0.0001) and at 12 hours postdose (274.7 +/- 131.2 sec to 377.4 +/- 186.2 sec; P < 0.0001). Sustained-release diltiazem is effective and safe in treating patients with chronic stable angina.

Angina Pectoris↗