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Biomedical subjects

T R Morgan

Publications and source records attributed to T R Morgan.

44 records · Page 3Linked to original sources
PubMed1986

Colorectal neoplasms and Barrett's esophagus.

Prospective colonoscopic study of 36 patients with Barrett's esophagus found colorectal adenomas in 33% of patients. Of patients aged less than 60, four of 17 (24%) had adenomas, while patients aged 60 or more had adenomas in eight of 19 (42%) cases. All adenomas were less than or equal to 10 mm diameter. No colorectal malignancies were found in these patients. This prevalence of neoplasms is consistent with results of autopsy studies. It is concluded that no increased risk of colorectal neoplasms was found in this group of patients with Barrett's esophagus.

Adenoma↗
PubMed1983

Topical epinephrine and regional ocular blood flow in aphakic eyes of rabbits.

The effects of 4% topical epinephrine bitartrate on regional ocular blood flow were studied in normal, "sham-operated," and aphakic eyes of rabbits. Anterior uveal blood flow decreased in all cases, but reductions in the ciliary processes were less pronounced in aphakic eyes than in sham-operated eyes. Doubling the dose (from 2 to 4 drops) abolished this difference in the ciliary processes, but the increased dose was accompanied by the emergence of a similar (although lesser) effect in the iris. The latter dose additionally decreased retinal blood flow in aphakic eyes compared with the sham-operated eyes. Lens extraction, thus, seems to remove a notable diffusion barrier to topical epinephrine, resulting in both attenuation of its anterior segment effects and in potentiation of a vasoconstrictive response in the posterior pole.

Animals↗
PubMed1981

A simple technique for extracapsular lens extraction in the rabbit.

The aphakic rabbit is a useful model for studying the ocular penetration and pharmacological action of topically applied drugs at the posterior pole, but the use of this model is complicated by the need for specialized preparative surgery. This paper describes a simplified procedure for planned extracapsular lens surgery which utilizes inexpensive instruments commonly available in an ophthalmology department or ophthalmic research laboratory.

Animals↗
PubMed1977

Efficient oxygen mask for patients undergoing hyperbaric oxygen therapy.

Hyperbaric oxygen (HBO) is established therapy for various disorders, but its effectiveness depends on the efficiency of the oxygen delivery system. A mask oxygen delivery system, consisting of the standard USAF aviator's A-14 regulator and the MBU-5/P oxygen mask, is installed in all USAF hyperbaric chambers. The efficiency of the mask oxygen delivery system at the USAF Hyperbaric Center, Brooks AFB, Tx, was evaluated breath-by-breath at sea level and 2.4 ATA via two different measuring techniques. Three groups of subjects were evaluated. Four subjects in Group I and seven subjects in Group II were randomly selected to use a single instrumented mask which was improperly fitted. The result was variable inspired oxygen levels from 64% to 100%. Six subjects in Group III wore properly fitted masks and achieved end-inspired oxygen levels ranging from 96% to 99%, for a mean of 97.8 +/- 0.5 (S.E.)%. A mean end-inspired oxygen level of 88,5 +/- 3,5 (S.E.)% was achieved within 5 min of mask donning. Inspiratory gas analyses indicate that the USAF aviator MBU-5/P mask and the A-14 regulator as used at the USAF Hyperbaric Center constitute a highly efficient oxygen delivery system for HBO therapy. This view has been refleced in arterial blood gas measurements and in preliminary data from tissue oxygen measurements in a gas gangrene patient. Future improvements in patient therapy masks are recommended.

Air↗
PubMedDate not supplied

Ascitic fluid analysis in malignancy-related ascites.

A prospective study identified 45 patients with malignancy-related ascites among 448 ascites patients (10% of the total). Patients were categorized into five subgroups based on the pathophysiology of ascites formation. Each subgroup had a distinctive ascitic fluid analysis. Patients with peritoneal carcinomatosis but without massive liver metastases (53.3% of the patients with malignancy-related ascites) had a uniformly positive ascitic fluid cytology, high ascitic fluid protein concentration and low serum-ascites albumin gradient. Patients with massive liver metastases and no other cause for ascites formation (13.3% of the series) had a negative cytology, low ascitic fluid protein concentration, high serum-ascites albumin gradient and markedly elevated serum alkaline phosphatase. Those with peritoneal carcinomatosis and massive liver metastases (13.3% of the series) had a nearly uniformly positive ascitic fluid cytology, variable protein concentration, high serum-ascites albumin gradient and markedly elevated serum alkaline phosphatase. Chylous ascites (6.7%) was characterized by a milky appearance, negative cytology and an elevated ascitic fluid triglyceride concentration. Patients with hepatocellular carcinoma superimposed on cirrhosis (13.3%) had negative ascitic fluid cytology, low ascitic fluid protein concentration, high serum-ascites albumin gradient and elevated serum and ascitic fluid alpha-fetoprotein concentration. Two-thirds of patients with malignancy-related ascites had peritoneal carcinomatosis; 96.7% of patients with peritoneal carcinomatosis had positive ascitic fluid cytology. Ascitic fluid analysis is helpful in identifying and distinguishing the subgroups of malignancy-related ascites.

Alkaline Phosphatase↗
PubMedDate not supplied

Protein energy malnutrition in severe alcoholic hepatitis: diagnosis and response to treatment. The VA Cooperative Study Group #275.

BACKGROUND: Active nutrition therapy and the anabolic steroid oxandrolone (OX), in selected patients with severe alcoholic hepatitis, significantly improved liver status and survival. We report here on the changes in their nutritional parameters. METHODS: Protein energy malnutrition (PEM) was evaluated and expressed as percent of low normal in 271 patients initially, at 1 month and at 3 months. Active therapy consisted of OX plus a high caloric food supplement vs a matching placebo and a low calorie supplement. RESULTS: PEM was present in every patient; mean PEM score 60% of low normal. Most of the parameters improved significantly from baseline on standard care; the largest improvement seen in visceral proteins, the smallest in fat stores (skinfold thickness). Total PEM score significantly correlated with 6 month mortality (p = .0012). Using logistic regression analysis, creatinine height index, hand grip strength and total peripheral blood lymphocytes were the best risk factors for survival. When CD lymphocyte subsets replaced total lymphocyte counts in the equation, CD8 levels became a significant risk factor (p = .004). Active treatment produced significant risk factor (p = .004). Active treatment produced significant improvements in those parameters related to total body and muscle mass (ie, mid arm muscle area, p = .02; creatinine height index, p = .03; percent ideal body weight, p = .04). CONCLUSION: Deterioration in nutritional parameters is a significant risk factor for survival in severe patients with alcoholic hepatitis. This deterioration is reversible with standard hospital care. Active therapy further improves creatinine height index, mid arm muscle area and total lymphocyte counts. Hence, these later parameters appear to be the best indicators for follow-up assessments.

Adult↗
PubMedDate not supplied

Water soluble marihuana-derived material: pharmacological actions in rabbit and primate.

Further studies have been made with water soluble marihuana-derived material (MDM). Neither adrenergic, cholinergic, aldosterone, dopamine or serotonin antagonism affected the fall in intraocular pressure induced by MDM. Partial blockade was obtained with galactose, glucose, or mannose, but not arabinose, when the latter were given at intravenous concentrations of 1 gm/animal and MDM was given at 25 micrograms animal, suggesting that these sugars may be involved at the active site of the MDM glycoproteins. Dexamethasone was without effect on either intravenous or intravitreal MDM indicating that the MDM effect is not a non-specific response to a protein. A similar plant glycoprotein, larch arabinogalactan, at 200 micrograms/animal was without effect on intraocular pressure. Aqueous humor flow rate was increased 3 hours after MDM administration, a period corresponding to the intraocular pressure increase caused by MDM, and fell to 20% of control values when the fall in intraocular pressure occurred. Blood flow through the iris was increased at both one and six hours after intravenous MDM injection indicating a vasodilation which could contribute to the initial increase in intraocular pressure. Intravitreal injection of MDM in rabbit and rhesus monkey caused a fall in intraocular pressure only after a 24 hour delay: the unilateral response indicated that systemic metabolism was not required for activity and the delay was likely caused by the diffusion time to the ciliary processes from the mid-vitreal injection site. The changes in beta-receptors, adenylate cyclase and carbonic anhydrase in the ciliary processes are minimal indicating a possible vascular mechanism of action of MDM.

Animals↗