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Biomedical subjects

E Harrison

Publications and source records attributed to E Harrison.

69 records · Page 4Linked to original sources
PubMedDate not supplied

Techniques and complications of esophageal foreign body extraction in children and adults.

To assess the success rates and complications of esophageal foreign body extraction in adult and pediatric patients, the charts of 76 adults and 116 children with endoscopically or radiographically documented esophageal foreign body impaction were retrospectively reviewed. Success rates for rigid esophagoscopy (100%) and flexible endoscopy (96.2%) were not significantly different (p > 0.05). Overall, rigid esophagoscopy had a higher complication rate than flexible endoscopy (10% versus 5.1%, p > 0.05), but this trend did not reach statistical significance. The Foley catheter technique was used predominantly in children with proximally located blunt objects. Our study shows that flexible and rigid esophagoscopy are both safe and effective methods of removing esophageal foreign bodies, but rigid esophagoscopy carries a higher complication rate and therefore should be reserved for patients in whom flexible endoscopy is unsuccessful. The Foley catheter technique is suited only for proximally located blunt objects, and its routine use is not recommended.

Aged↗
PubMedDate not supplied

Synapses in hippocampus occupy only 1-2% of cell membranes and are spaced less than half-micron apart: a quantitative ultrastructural analysis with discussion of physiological implications.

Relatively little information exists regarding the spatial structure of synaptic neuropil in the brain. The present electron microscopic study employs unbiased stereological techniques and Monte Carlo simulations to characterise quantitatively the spatial organisation of synaptic circuitry in the dentate gyrus of the hippocampus, an area of particular importance in mechanisms of learning and the subject of a number of experimental neurobiological models of synaptic plasticity such as long-term potentiation. Firstly, tissue shrinkage/expansion resulting from embedding was assessed by imaging 300-microm thick hippocampal slices in the course of the entire embedding protocol, giving a value of 94.3 +/- 1.1% for distance measures and 84.3 +/- 2.8% for volumetric measures. Secondly, numeric synaptic density, Nv, was estimated using the disector. Thirdly, accumulated area of post-synaptic densities (PSDs) per tissue volume, Sv, and the overall cell membrane area per tissue volume, Sv*, were assessed using unbiased stereological rules coupled with image analysis of single sections. Finally, the mean area of individual PSDs was derived as a ratio Sv/Nv giving: 0.0394 microm2 for axo-spinous PSDs (thus representing approximately 1.3% of total cell membranes) and 0.0769 microm2 for dendritic shaft PSDs (approximately 0.25% of total cell membranes). From these data, the mean nearest neighbour distance between synapses was estimated using Monte Carlo simulations of a random 3D arrangement of synapses constrained by PSD sizes (a truncated Poisson process), giving a value of 0.48-0.51 microm. The physiological importance of the morphometric data obtained is discussed in terms of assessing (i) the role of synaptic environment in modifying synaptic efficacy and (ii) the plausibility of cross talk between synapses in relation to extrasynaptic neurotransmitter diffusion and transient depletion of extracellular Ca2+.

Animals↗
PubMedDate not supplied

Difficult cases in heart failure: Left ventricular dysfunction related to septic shock masquerading as postpartum cardiomyopathy.

Peripartum cardiomyopathy, an uncommon cause of chronic heart failure, may present during the third trimester of pregnancy, but most often develops within 2 months postpartum. The etiologies of heart failure during pregnancy and postpartum are numerous, however. The authors describe the case of a 25-year-old woman who developed severe, symptomatic heart failure following delivery and discuss their initial consideration of peripartum cardiomyopathy and the differential diagnostic features of this case. (c)2001 CHF, Inc.

Journal Article↗
PubMedDate not supplied

Safety and efficacy of internal mammary artery grafts for left main coronary artery disease. A preliminary report.

Questions regarding the relative safety and efficacy of internal mammary artery (IMA) grafts versus saphenous vein grafts (SVG) in patients with left main coronary artery disease (LMCAD) have not been specifically addressed in the literature. To elucidate this point, we analyzed 196 patients with LMCAD who underwent myocardial revascularization between January 1975 and December 1981, 98 by IMA and SVG and 98 by SVG, IMA was used most often to bypass the left anterior descending (LAD). Chi Square and "t" tests were performed on all demographic, cardiac and operative data comparing IMA to SVG. All results were non-significant, indicating that the two groups were comparable. Anginal pattern was progressive or unstable in 93%. IMA was used in 4 patients who were on intra-aortic balloon pump. The mean number bypass grafts per patient was 3.1. Postoperative complications were comparable for both groups, including early and late myocardial infarction. Overall operative mortality was 2.6%. Results of a survival analysis indicated no significant difference in the mortality rates of patients operated on by SVG versus IMA-SVG. Cumulative mortality rates at a mean followup of 20.5 months were 12.2% for SVG and 7.1% for IMA patients. Significant mortality risk factors were ejection fraction less than 55% (p less than 0.05); and perioperative myocardial infarction (p less than 0.001). Twenty-five patients with recurrent chest pain underwent repeat cardiac catheterization. This revealed 10 of 10 patent IMA grafts, 6 of 8 single patent SVG to LAD and 6 of 9 patent sequential vein grafts to the diagonal and LAD arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMedDate not supplied

Advantages of superior approach for mitral valve surgery.

Technical factors in mitral valve surgery (MVS) which may influence neurological complications, trauma to the left atrium and formation of atrial mural thrombi have not previously been described in detail. We have reviewed the records of 146 patients (pts) undergoing MVS through the superior approach between January 1974 and May 1981. The series consisted of 97 females and 49 males with a mean age of 57 +/- 18 years. All but 4 pts were in New York Heart Association functional class III or IV. Twenty-five pts underwent open mitral commissurotomy, 116 had valve replacement and 5 had annuloplasty. Concomitant procedures were coronary bypass in 47, aortic valve replacement in 18 and resection of left ventricular aneurysm in 3. Left atrial thrombi were removed in 21 pts. Thirteen pts (9%) died postoperatively. The causes of death were left ventricular failure in 7, arrhythmia in 4 and atrio-ventricular disruption in 2. Two of these pts also had cerebral dysfunction. Autopsy examination in 8 pts failed to reveal formation of fresh left atrial septal or posterior mural thrombus. Postoperative complications included transient neurologic injury presumed to be due to air embolus in 3 and postoperative bleeding from atrial suture line in one. The mean follow-up for the survivors has been 30 months. There have been 16 (12%) late deaths from 1 to 72 months (mean 15). Autopsy examination of 4 pts and surgical exploration in one other pt which failed to reveal organized left atrial mural thrombus. Only one late death was related to prosthetic thrombosis. This occurred following cessation of anticoagulations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Vitamin A status and nutrient intake in a rural community in southern Ghana.

The present study was designed to assess the vitamin A status in a rural community (Gomoa Onyadze) in southern Ghana, to determine if there is any vitamin A deficiency in the community and also to estimate the nutrient intake of the inhabitants to see if the levels conform to the Recommended Dietary Allowance (RDA). Results of serum vitamin A analysis indicated that out of total of 263 subjects (3-60 years) screened, 0.76% had deficient vitamin A level of < 10 micrograms/1); 11.79% had low levels of 10-20 micrograms/dl; 83.65% had adequate levels of 20-50 micrograms/dl, while 3.80% had high levels (> 50 micrograms/dl). Since the deficient group (i.e. < 10 micrograms/dl) was less than 5% of total subjects screened, it is concluded that there is no vitamin A deficiency in the community. Dietary intake measurements showed that nutrient intake in subjects with normal or abnormal levels of vitamin A are similar and are, with some exceptions (energy, vitamin-thiamine, riboflavin and niacin), acceptable when compared with the RDA.

Adolescent↗