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Biomedical subjects

D A Scott

Publications and source records attributed to D A Scott.

At least 127 records · Page 7Linked to original sources
PubMed1991

Butorphanol compared with fentanyl in general anaesthesia for ambulatory laparoscopy.

Butorphanol was compared with fentanyl as the narcotic component of general anaesthesia for ambulatory laparoscopic surgery. This double-blind, randomized study enrolled 60 healthy women who received equianalgesic doses of fentanyl 1 microgram.kg-1 (F, n = 30) or butorphanol 20 micrograms.kg-1 (B, n = 30) prior to induction of anaesthesia. Tracheal anaesthesia was maintained with nitrous oxide/oxygen, isoflurane, and succinylcholine by infusion. Intraoperatively, patients who received B demonstrated lower pulse rate before and after intubation (P less than 0.05, P less than 0.01) and lower diastolic blood pressure after intubation (P less than 0.01). Anesthesiologists judged the maintenance phase as satisfactory more often with B (P less than 0.05). Postoperatively, there were no differences in analgesic need. No major side-effects occurred in either group. Among minor side-effects, patients who received B reported postoperative sedation more often, 77% vs 37% (P less than 0.01), which occurred during the first 45 min of recovery (P less than 0.05). Discharge times were not different. On the first postoperative day, more subjects who received B were satisfied with their anaesthesia experience (P less than 0.05). Butorphanol 20 micrograms.kg-1 is an acceptable alternative analgesic in general anaesthesia for ambulatory laparoscopy.

Adult↗
PubMed1991

Low prevalence of human immunodeficiency virus-1 (HIV-1), HIV-2, and human T cell lymphotropic virus-1 infection in Somalia.

A seroepidemiologic survey was conducted to determine the prevalence of human immunodeficiency virus type 1 (HIV-1), HIV-2, human T cell lymphotropic virus type I (HTLV-I), and Treponema pallidum infection among southern Somalis. Sera were collected from 1,269 study subjects in the urban area of the capital city, Mogadishu, and in the rural towns of Merka, Qoryoley, and Kismayo. The subjects included 57 prostitutes, 79 sexually transmitted disease (STD) patients, and 1,133 others, including outpatient and hospitalized patients with leprosy, tuberculosis, other infectious diseases, individuals from rehabilitation camps and secondary schools, and Ethiopian immigrants. Results indicated that none of the sera were positive for HIV-1 and HIV-2 by Western blot, but one was positive for HTLV-I. The prostitutes had a significantly higher prevalence of treponemal antibody (50.8%; P less than 0.0001) than either the STD patients (12.6%) or the other subjects (5.2%). Epidemiologic data indicated that 94% of the males and females were circumcised and only 2.6% of the males used condoms. Overall, the results of this study suggested a very low prevalence of HIV-1, HIV-2, and HTLV-I infections, especially among prostitutes and STD patients, who were considered at greatest risk of contracting these retroviral infections.

Adolescent↗
PubMed1991

Computer systems for dental practice management. A new generation of independent dental software.

A new generation of computer programs for dental patient management eliminates total dependence on the vendor for programming support. The software design enables information collected with the dental system to be transferred to popular off-the-shelf programs designed for business. A simplified example is used to illustrate for practitioners the advantages of this type of data structure management. Programs designed on this basis offer optimum performance and expandibility for both present and future needs.

Computer Systems↗
PubMed1991

Delayed subcapsular hematoma after percutaneous liver biopsy as a manifestation of warfarin toxicity.

Guidelines for the management of patients receiving chronic anticoagulation therapy who require liver biopsy are not clearly defined. In patients with normal coagulation, liver biopsy is a relatively safe procedure with a morbidity of less than 0.1% and a mortality of less than 0.01%. We report a patient with a prosthetic aortic valve who developed a large subcapsular hematoma 12 days after a percutaneous liver biopsy as a consequence of warfarin toxicity. Based on the experience with this patient, reinstitution of anticoagulant therapy should be avoided for at least 72 h after a percutaneous liver biopsy. Intravenous heparin should be resumed first, and warfarin added if no bleeding has occurred after an additional 48-72 h. The prothrombin time should be maintained at 1.5 times the baseline.

Biopsy, Needle↗
PubMed1991

Incidental microvesicular steatosis due to valproic acid anticonvulsant therapy.

Valproic acid has been implicated in at least 100 cases of fatal acute liver failure. Most cases have occurred in patients less than 10 yr old; however, at least seven have involved adults. Microvesicular steatosis has been uniformly observed, but its incidence in less severe liver disease and in asymptomatic patients receiving valproate is unknown. We report two patients receiving maintenance valproate, one with resolving acute hepatitis C and the other with chronic persistent hepatitis C, with incidental microvesicular steatosis demonstrated on oil-red O stains. We conclude that microvesicular steatosis does not necessarily signify hepatotoxicity in patients on chronic valproic acid, and should not lead to discontinuation of the drug until other causes of acute or chronic liver disease have been excluded.

Adult↗
PubMed1990

Colorimetric glucose assay using thermostable glucokinase.

A method for assaying glucose in serum or plasma samples using a thermostable glucokinase was developed. Glucokinase from Bacillus Stearothermophilus was coupled with glucose-6-phosphate dehydrogenase to produce NADPH, which reduced the tetrazolium dye MTT to its formazan. Detection of the product at 660 nm allowed samples containing up to 30 mmol/L glucose to be assayed with an endpoint method. Use of the optimal wavelength for formazan detection, 570 nm, increased sensitivity for NADPH detection by over threefold compared to UV detection. The stability of glucokinase assay mixtures was extensively studied, with variation in buffers, salt and enzyme stabilizers. Maximal half life for reagent stability at room temperature was approximately 30 days, with storage of assay mixtures in two solutions. Various drugs and metabolites were tested for interference in the method and no significant interferences were found.

Blood Glucose↗
PubMed1990

Norfloxacin for the prophylaxis of travelers' diarrhea in U.S. military personnel.

Norfloxacin, an oral fluoroquinolone (dose 400 mg daily), was compared to a placebo in a double blinded randomized trial for the prophylaxis of travelers' diarrhea. The study was of U.S. Navy and Marine Corps personnel on shore leave in Alexandria, Egypt. A total of 222 subjects were available (105 norfloxacin, 117 placebo). In the placebo group, 26% (30/117) developed acute diarrhea vs. 2% (2/105) in the norfloxacin group. There were no significant side effects in either group.

Acute Disease↗
PubMed1989

Measurement of the discomfort component of illness.

Discomfort is a prominent component of illness, but it is difficult to measure on a scale that allows its formal inclusion in a health status index. The authors tested the content validity of defining various discomforts in terms of their quality, duration, and intensity and found no responses that could not be categorized within this conceptual framework. They then analyzed the ability of patients to ascribe preference values to a sample of discomfort statements, based on this characterization of discomfort, and found them able to do this reliably using magnitude estimation. These results show that, although the universe of discomforts cannot be measured directly on a common scale, they can be compared using a scale of social preference. This will allow the formal incorporation of the discomfort component of illness into health status indexes based upon dysfunctions, discomforts, and prognosis.

Adult↗
PubMed1988

Effects of dietary fiber in vervet monkeys fed "Western" diets.

Male Vervet monkeys (7/treatment) were fed a "Western" diet containing 46.2% calories as fat, 39.8% as carbohydrate and 14.0% as protein. The diet was augmented with 10% cellulose or 10% pectin. A third (control) group of seven monkeys was fed a commercial ration augmented with fruit and bread. After 34 weeks, serum cholesterol levels were elevated significantly in the two test groups compared with the controls but there was no difference between the two fiber-fed groups. Serum triglycerides were unaffected. Liver cholesterol levels were the same in all three groups but liver triglyceride levels were lower in the monkeys fed cellulose. Biliary lipids were similar in all three groups as were the calculated lithogenic indices. The average aortic sudanophilia (percent of total area) in the three groups was cellulose, 10.6 +/- 2.5; pectin, 8.1 +/- 2.5; and control, 1.1 +/- 0.4. One animal in each of the groups fed "Western" diet exhibited an atherosclerotic plaque. The results indicate that there is no difference between pectin and cellulose with regard to their effects on either lipidemia or aortic sudanophilia in Vervet monkeys fed a Western-type diet.

Animals↗
PubMed1988

Disorders of the hair and scalp in blacks.

The hair follicle and shaft in blacks have unique configurations. The occurrence of certain disorders such as hot-comb and traction alopecia, proximal trichorrhexis nodosa, trichonodoses, and pseudofolliculitis predominantly among blacks is related to the morphology as well as methods of caring for black hair. In addition, there are several disorders of unknown etiology such as dissecting cellulitis that also occur primarily in blacks. Familiarity with all of the structural differences that distinguish black hair and the disorders that affect the black patient's hair and scalp will enable dermatologists to provide proper diagnoses, treatment, and counselling for their black patients.

Black People↗
PubMed1988

An experimental in vivo study of the canine internal mammary artery and its response to vasoactive drugs.

The internal mammary artery is clearly the preferred conduit for most patients undergoing coronary artery bypass grafting. However, the hemodynamic responses of this graft to vasoactive agents immediately after bypass have not been documented. We have therefore studied blood flow in the canine internal mammary artery after anastomosis to the left anterior descending artery, and its response to epinephrine, metaraminol, isoproterenol, and calcium chloride. Blood flow in the internal mammary artery clearly paralleled changes in systolic blood pressure with perfusion pressure being of prime importance in maintaining flow in the internal mammary artery. No deleterious effect of systemic vasoconstricting agents was demonstrated. We suggest that the administration of these drugs is safe in patients with internal mammary artery grafts.

Animals↗
PubMed1987

Folate utilisation by Leishmania species and the identification of intracellular derivatives and folate-metabolising enzymes.

The use and metabolism of folates by leishmanias have been studied by assessing the growth of promastigotes in defined media with different folates and the cell content of folate-metabolising enzymes. The folates present in Leishmania mexicana mexicana have been determined using HPLC. Folic acid, 5-formyltetrahydrofolate (THF) and 5-methyl-THF each supported growth of L. m. mexicana promastigotes in defined medium, whereas the parasites did not survive in the absence of folates; p-aminobenzoic acid could not replace the folate requirement. The only folate present at detectable levels in L. m. mexicana promastigotes was 5-methyl-THF. Dihydrofolate reductase (EC 1.5.1.3), methylene-THF reductase (EC 1.1.1.68), serine hydroxymethyltransferase (EC 2.1.2.1) and thymidylate synthetase (EC 2.1.1.45) were all detected in extracts of promastigotes of L. m. mexicana, L. donovani and L. major. Some of these activities were also found in extracts of amastigotes of the former two species. The enzymes of L. m. mexicana have been partially characterised. Methylene-THF reductase may be involved in the conversion in vivo of 5-methyl-THF to 5,10-methylene-THF.

Animals↗
PubMed1986

The rational zero point for an illness index with ratio properties.

To be of greatest use for the measurement of significant variations in treatment outcomes, a health status index should have ratio properties. Previous attempts to construct such a scale using the magnitude estimation technique have failed, principally because of an inappropriate choice for the zero point. By rejecting death as the logical zero point for a scale of social preference and choosing instead the absence of that being measured (dysfunction and discomfort), the authors attained reliable values from patients, for an illness index, using magnitude estimation. This type of scale allows comparative judgments between treatment methods to be made with greater validity. It should aid in the wise allocation of health care resources.

Adolescent↗
PubMed1985

Muscle-fiber compartmentalization in cat splenius muscles.

Splenius is a structurally complex muscle that is supplied by nerves from four cervical segments. We have examined the architectural organization of extrafusal fibers in splenius by microdissecting muscles stained "en bloc" with gold chloride. We also analyzed the distribution of motor units supplied from different cervical segments using the glycogen-depletion technique. Microdissections show that the fiber architecture of splenius is different in medial and lateral muscle parts. In medial splenius, muscle fascicles run uninterrupted from the muscle origin to insertion, while in lateral splenius, separate compartments of muscle fascicles are linked in series by two tendinous inscriptions. In muscle fascicles longer than 2.0 cm, many extrafusal fibers do not run the whole length of the fascicle. Instead, these fibers end intramuscularly by tapering to a fine strand that is closely adherent to adjacent extrafusal fibers. Less than 1% of extrafusal fibers in splenius exceeds 3.0 cm in length. Experiments using glycogen depletion showed that nerves from different spinal segments innervate different muscle regions. Nerves from C1 supply muscle fibers in a small rostromedial zone. Nerves from C2-C4 have motor domains that extend from the medial to the lateral muscle edge and are arranged in series. In lateral splenius, the motor domains are separated by tendinous inscriptions. In medial splenius, where no inscriptions are present, the motor domains of adjacent segmental nerves have overlapping boundaries due to the extensive interdigitation of motor units supplied from different segmental nerves. A single muscle fascicle in medial splenius is commonly composed of two sets of fibers supplied by adjacent segments that are distributed at opposite ends of the fascicle and interdigitate in midregions of the fascicle. The in-series compartmentalization of splenius has important implications for its motor control. To secure effective muscle shortening or tension development, central mechanisms may be required to coordinate the recruitment of in-series motor units. The presence of many short fibers with intramuscular insertions leads us to question how contractile forces are developed and transmitted in splenius and other mammalian muscles that are composed of short, in-series fibers.

Animals↗