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Biomedical subjects

M Hill

Publications and source records attributed to M Hill.

At least 325 records · Page 18Linked to original sources
PubMed1989

Teaching after CABG surgery: a family affair.

CABG surgery is a stressor that severely compromises the integrity of the family. In the role of teacher, the critical care nurse can function as a catalyst to facilitate the togetherness of the family. This goal may be achieved by the nurse using easily planned and presented teaching-learning strategies described in this article. Family wholeness can be encouraged by the nurse instructing both the patient and spouse in the basic skills and general knowledge necessary to perform postoperative care. In this capacity, the nurse can also establish a foundation for life-long commitment to healthful behaviors. Thus, the instruction of the nurse facilitates the mutual support needed by family members to achieve positive rehabilitation. Truly, teaching after CABG surgery is a family affair.

Coronary Artery Bypass↗
PubMed1988

The consistency of theophylline absorption from a sustained-release formulation in asthmatic children.

Theophylline absorption was studied in asthmatic children ages 2-7 years. A bead-filled capsule of sustained-release theophylline (Slo-Bid, William H. Rorer, Inc., Fort Washington, PA) was administered in equal doses twice daily (8 AM and 8 PM) to produce serum theophylline concentrations (STCs) between 10 and 20 micrograms ml. After 7 days, blood samples were obtained every 2 hours for 24 hours. This sequence was repeated after another seven days of treatment. Elimination values were calculated after an intravenous reference dose. Slo-Bid was completely absorbed (mean +/- SD percentage of dose absorbed of 117.1 +/- 26.1 on day 1, and 104.8 +/- 16.1% on day 2), and the pattern of absorption was consistent from day to day, with maximum STCs occurring 2-6 hours after the dose, and minimum STCs at or near the time of PM dose. The percentage of fluctuation of 149.7 +/- 49.7% and 163.0 +/- 114.0% (mean +/- SD) on days 1 and 2, respectively, was slightly higher than desired, but probably was a result of rapid theophylline clearance in this group of children (119.9 +/- 25.8 ml/hr/kg). Mean residence time for absorption after AM and PM doses indicated significantly longer time for absorption (ta) after the PM doses: mean +/- SEM ta for AM doses on days 1 and 2 was 2.8 +/- 0.3 and 2.7 +/- 0.2 hours, respectively, and increased to 3.9 +/- 0.3 and 3.7 +/- 0.5 hours after PM doses on days 1 and 2, respectively (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1988

Presence of human papilloma virus types 16 and 18 in genital warts and cervical neoplasias.

Certain types of human papilloma viruses (HPV) are associated with human genital proliferative diseases, and among them HPV16 and HPV18 seem to play an important role in the occurrence of cervical cancer. We used restriction enzyme analysis and molecular hybridization, in order to investigate the type of viral infection and the physical state of viral DNA in gynecological benign, pre-malignant and malignant lesions. HPV6/11 specific sequences could only be detected as episomes and this in benign lesions classified as condylomata acuminata. On the other hand, HPV16 and HPV18 sequences were detected in non-malignant lesions such as flat condylomata (7 out of 14 cases), pre-malignant lesions including cervical intra-epithelial neoplasias (10 out of 20 cases), and most frequently in cervical invasive cancers (21 out of 27 cases). In a large number of virus-positive cases, HPV16 and HPV18 could only be discerned in forms consistent with the existence of episomes and/or randomly integrated head-to-tail oligomers. However, some invasive carcinomas and cervical intra-epithelial neoplasias contained, in addition, clonal outgrowths with detectable virus-cellular junction fragments of the integrated viral genomes. In the light of these data, monitoring the type of viral infection proves to be an important adjunct to histological analysis when assessing those patients affected by condyloma or cervical intra-epithelial neoplasia who are at risk for developing invasive carcinoma.

Carcinoma↗
PubMed1988

Evaluation of an office method of measuring theophylline serum concentrations.

A strip test for theophylline, with an immunoassay with a colorimetric indicator, has been developed for use in the physician's office (Seralyzer, Ames Division, Miles Laboratories, Elkhart, Ind.). Diluted serum is applied to the plastic reagent strip, which is then inserted into a reflectance photometer that quantitates the color change and displays the serum concentration in 80 seconds. To determine the reliability of this method, control sera (5.0, 10.0, 15.0, 20.0, and 25.0 micrograms/ml of theophylline) and 78 specimens, each from a different patient, were analyzed by Seralyzer and a reference method (EMIT, Syva Co., Palo Alto, Calif.). Nine replicate measurements of a 15.0 micrograms/ml control serum were performed on one day, an all five control sera were analyzed once daily for 20 days. Patient specimens were analyzed at the rate of eight per day. The coefficient of variation (mean/SD X 100) for within day precision of the 15 micrograms/ml control was 5.2% for Seralyzer and 4.1% for EMIT (p less than 0.05). Coefficients of variation for between-day precision of the Seralyzer were less than 10% at concentrations greater than 5 micrograms/ml, but were significantly greater than EMIT measurements at 5 and 10 micrograms/ml (p less than 0.05). There was a strong correlation between the two methods for the 78 patients' specimens (r2 = 0.95). The Seralyzer demonstrated a positive bias of 0.9 microgram/ml. Results analyzed by the two methods differed by greater than 25% in 10 of the 78 specimens (mean error, 3.3 micrograms/ml over the range of 2.9 to 22.2 micrograms/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1988

Dose response of inhaled gallopamil (D600), a calcium channel blocker, in attenuating airway reactivity to methacholine and exercise.

To determine if there is a dose-response relationship for calcium channel blockers in preventing experimentally induced bronchoconstriction, we evaluated the effects of inhaled gallopamil (D600), a potent methoxy derivative of verapamil, on airway reactivity to methacholine and exercise in volunteers with mild asthma. Methacholine challenges were completed by 11 subjects 2 hours before and 20 minutes after placebo, and 1, 2, 5, 10, and 20 mg of inhaled gallopamil administered in a single-blind, randomized manner on different days. Gallopamil did not significantly alter FVC, FEV1, or forced expiratory flow rate between 25% and 75% of FVC, but increased the dose of methacholine required to produce a 20% decrease in FEV1 from baseline (p less than 0.0001). The mean +/- SEM fold increase in the dose of methacholine required to produce a 20% decrease in FEV1 from baseline was 1.0 +/- 0.1 after placebo, 2.4 +/- 0.2 after 1 mg, 2.2 +/- 0.2 after 2 mg, 2.5 +/- 0.2 after 5 mg, 2.5 +/- 0.3 after 10 mg, and 2.3 +/- 0.2 after 20 mg. Thirty minutes before a standardized exercise challenge, 10 subjects inhaled 1 and 10 mg of gallopamil or placebo in a randomized, double-blind, crossover manner. The mean +/- SEM maximum decrease in FEV1 after exercise was 25.1 +/- 5% after 10 mg of gallopamil (p less than 0.01), 34.4 +/- 5% after 1 mg (p greater than 0.05), and 39.0 +/- 6% after placebo. We conclude that inhaled gallopamil only modestly alters airway reactivity to methacholine; increasing the dose greater than 1 mg did not provide greater benefit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Increased risk of biliary tract cancer following gastric surgery.

Analysis of 4,466 peptic ulcer patients, who had undergone gastric surgery at least 25 years previously, showed no change in risk from biliary tract cancer within the first 20 years, but a 9.4 fold (P less than 0.001) excess risk thereafter. The increased risk was 15.8 fold (P less than 0.001) 20 years after operation for gastric ulcer patients and 5.1 fold (NS) in duodenal ulcer patients. When the risk was analysed by subsite it was found that there was no increased risk at any time after operation for cancer of the bile duct, and that all of the excess risk 20 or more years after operation (14.7 fold; P less than 0.001) was for cancer of the gallbladder.

Adult↗
PubMed1988

Dose-response of inhaled diltiazem on airway reactivity to methacholine and exercise in subjects with mild asthma.

Methacholine challenges were performed by 10 asthmatic subjects, 2 hours before and 15 minutes after placebo (diluent alone) and 5, 10, 15, 30, and 60 mg inhaled diltiazem given in a single-blind crossover manner. There was no significant change from placebo in the dose of methacholine required to produce a 20% decrease in forced expiratory volume in the first second (FEV1) (PD20); the fold increase in PD20 from baseline was 1.1 +/- 0.1 after placebo, 1.4 +/- 0.2 after 5 mg, 1.8 +/- 0.3 after 10 mg, 1.4 +/- 0.2 after 15 mg, 1.6 +/- 0.2 after 30 mg, and 1.2 +/- 0.1 after 60 mg. There was a 1% chance that we missed a twofold difference between placebo and the 10 mg dose because of inadequate sample size. Fifteen minutes before a standardized exercise challenge, 10 subjects received placebo, 10 mg, and the highest dose tolerated during the methacholine study (20 to 45 mg) in a randomized double-blind crossover design. The mean +/- SE maximum postexercise decrease in FEV1 was 28.8% +/- 5.7% after placebo, 23.4% +/- 4.6% after 10 mg, and 20.8% +/- 3.0% after high-dose diltiazem (P greater than 0.05). There was a 12% chance that we missed a 15% difference between placebo and the high-dose regimen because of inadequate sample size. We conclude that diltiazem does not attenuate airway reactivity to methacholine or exercise even when high concentrations are delivered to the lungs.

Adult↗
PubMed1988

Results of routine patch testing of 542 patients in Saskatoon, Canada.

542 patients (330 women, 212 men) with suspected allergic contact dermatitis were patch tested to standard series allergens between January 1983 and June 1987. Positive reactions were most frequently seen with nickel (17.4%), ethylenediamine (8.7%), formaldehyde (7.4%), colophony (7.0%), potassium dichromate (6.1%) and neomycin (5.7%). Patients with dermatitis involving the legs were significantly more likely to be allergic to ethylenediamine (p = 0.01) and benzocaine (p = 0.04) than those with dermatitis not involving the legs. Neomycin allergy was not associated with dermatitis involving the legs. Patients allergic to ethylenediamine were significantly more likely to be allergic to neomycin than patients not allergic to ethylenediamine (p = 0.002).

Adolescent↗
PubMed1988

Sustained release theophylline preparations. Practical recommendations for prescribing and therapeutic drug monitoring.

Theophylline is an important antiasthmatic medication which has bronchodilator properties. With increased understanding of the relationships of serum theophylline concentration and effect, both adverse and beneficial, oral dosage forms were developed to provide consistent serum theophylline concentrations with the benefit of convenient dosage intervals for long term use. Since factors such as concurrent disease states, drug interactions and age have a profound effect on theophylline disposition, relatively sophisticated dosage guidelines have evolved. Theophylline is in fact a model drug for the application of pharmacokinetic principles to the individualization of a treatment regimen. The purpose of this discussion is to review the relationship of serum theophylline concentration and pharmacodynamic effect and the special properties of oral sustained release theophylline formulations, and to provide a practical approach to prescribing theophylline. Guidelines are provided on the use of serum theophylline concentrations to individualize the theophylline dose, with an analysis of available techniques to monitor theophylline.

Asthma↗
PubMed1988

Molecular cloning of a novel oncogene generated by DNA recombination during transfection.

Genomic DNA of a Ewing's sarcoma cell line and pKOneo were cotransfected into NIH3T3 cells and assayed for tumorigenicity in nude mice. Primary transfected tumors all contained human DNA. One transfected sequence was retained through secondary and tertiary tumors, and was cloned in four overlapping cosmids covering 51.5-kb human DNA flanked on both sides with mouse DNA. The cloned sequence, though continuous in transfected tumors, originated from three major genetic elements discontiguous in human cells and recombined during transfection. Accordingly there was one species of hybrid RNA transcripts of 9 kb in the transfected tumors and no transcripts in human cells, including Ewing's sarcoma cells. Evidence that the cloned sequence is a biologically active novel oncogene was provided by transfection of a mixture of two cosmid clones which generated tumors where they were transcribed into 9-kb RNA. The oncogene was named tre to designate its origin from transfection recombined DNA molecules.

Animals↗
PubMed1988

Analysis of employment specialist intervention time in supported competitive employment.

Results of an initial analysis of the employment specialist intervention time provided to consumers in supported competitive employment programs operated by the Rehabilitation Research and Training Center (RRTC) at Virginia Commonwealth University over 8 years was described. Analyses focused on the amount of staff intervention time provided as a percentage of the total number of hours worked by a consumer each week and a comparison of the amount of intervention time provided to two subsamples. Results indicated that consumers previously classified moderately or severely mentally retarded did not require a significantly greater amount of intervention time than those previously classified as borderline or mildly retarded during the first year of employment.

Adult↗
PubMed1988

Regulation of a murine macrophage haemagglutinin (sheep erythrocyte receptor) by a species-restricted serum factor.

The mechanisms which generate heterogeneity amongst resident tissue macrophages (M phi) are poorly understood. In a previous study we described a novel mouse M phi haemagglutinin, which binds unopsonized sheep erythrocytes. This sheep erythrocyte receptor (SER) is expressed at high levels on stromal M phi from bone marrow and lymph nodes, but at low levels on M phi from serous cavities and broncho-alveolar spaces. In this paper we demonstrate that a species-restricted factor in mouse serum is required in vitro for optimal maintenance of SER on resident bone marrow M phi and for its induction on M phi populations which normally lack this receptor. Using thioglycollate-elicited peritoneal M phi, induction of SER by mouse serum was dose-dependent, reached maximal levels by 3-4 days, required the continuous presence of mouse serum, and was fully reversible. Re-expression following trypsinization was inhibited by cycloheximide, showing that protein synthesis by M phi was necessary. Using a quantitative microtitre plate assay to measure levels of the inducing activity (SER-IA) in different samples, it was found to be heat-labile, non-dialysable, precipitable by polyethylene glycol and inactivated at pH 4 but not at pH 9.6. On gel filtration of mouse serum, a single major peak of activity was obtained with an apparent MW of around 70,000. SER-IA appears to be unrelated to a variety of factors and cytokines which affect M phi function, including colony-stimulating factor-1 (CSF-1). The possible role of SER-IA in regulating the differential expression of SER in vivo is discussed.

Animals↗
PubMed1988

A rearranged transforming gene, tre, is made up of human sequences derived from chromosome regions 5q, 17q and 18q.

The transfection recombinant transforming gene, tre, originated from discontinuous human genetic elements after transfection of NIH3T3 cells with genomic DNA from a Ewing's sarcoma cell line. Probes for the three normally discontinuous human elements involved in the transfection recombinant were subcloned and used in conjunction with a panel of rodent-human hybrid cells to determine their normal location in the human genome. The leftmost (5') element derives from the long arm of chromosome 5 (5q); the internal fragment derives from human chromosome 18 proximal to the bcl-2 gene; and the rightmost (3') element derives from the long arm of chromosome 17 (17q) distal to an acute leukemia breakpoint at 17q21. In situ hybridization of the same probes to human metaphase chromosomes confirmed localization of these sequences to regions 5q23----q31, 18q12, and 17q12----q22.

Animals↗
PubMed1988

Bioavailability of a slow-release theophylline capsule given twice daily to preschool children with chronic asthma: comparison with liquid theophylline.

The reliability of slow-release theophylline products in young children has been questioned. Therefore, we studied the bioavailability of a commonly prescribed slow-release theophylline formulation (Slo-Bid Gyrocaps), administered twice daily by sprinkling the beads on applesauce. Serial measurements of serum theophylline concentrations were obtained during steady state in eight children (ages 1.6 to 5 years) after receiving a reference liquid theophylline product every six hours and also while receiving the slow-release product every 12 hours. The morning dose of slow-release theophylline was given before the child had eaten, and the evening dose was given two hours after supper. The extent of absorption of the slow-release product was 98.3 +/- 20.2% (mean +/- SD) relative to the liquid reference. The serum concentration fluctuations, expressed as percentage of the measured trough, did not differ between the two products: 108 +/- 59% v 129 +/- 97% (P greater than .05) for reference and slow-release products, respectively. Three of the eight patients had unacceptably large fluctuations (greater than 100%) while receiving the slow-release regimen, and two of these three had unacceptable fluctuations while receiving the liquid reference. The rate of absorption was slower after the evening dose of slow-release product (postprandial), resulting in significantly smaller fluctuations, and lower peak concentrations. Time to peak concentration while receiving the slow-release regimen varied from two to four hours after the evening dose and from two to eight hours after the morning dose. However, the average difference between the peak concentration and the four-hour measurement after the morning dose was only 0.3 microgram/mL (range 0 to 2.6 micrograms/mL).(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1987

Bacterially catalysed N-nitrosation reactions and their relative importance in the human stomach.

Human exposure to endogenously formed N-nitroso compounds has frequently been suggested as a causative factor in carcinogenesis where this is related to chronic bacterial infection such as is seen in gastric achlorhydria. At least two distinct mechanisms of endogenous formation have been identified. The first, a direct chemical reaction between secondary amino compounds and nitrite, is strongly pH dependent and does not proceed rapidly at neutral pH even in the presence of chemical catalysts. The second depends on the direct bacterial catalysis of N-nitrosation. The data presented demonstrate that the bacterially mediated reaction is catalysed by bacterial enzyme systems and proceeds much more rapidly at neutral pH than the chemical reaction. This suggests a particular relevance to the in vivo situation where neutral pH, bacteria and elevated nitrite concentrations are found. Drawing on the kinetic information presented regarding the bacterially mediated nitrosation reaction, the known kinetics of the chemical reaction and the published values for the relevant substrate concentrations in both the colonised and the normal acid stomach the bacterial and chemical reactions have been compared. Using these criteria, and assuming the presence of bacteria with the appropriate metabolic activity, it may be predicted that N-nitroso compounds may be formed in the colonized stomach at much higher concentrations than in the normal acid stomach. The difference in yield may be by two to four orders of magnitude. Different bacterial species and different isolates of the same species show considerable variation in their abilities to catalyse N-nitrosation reactions. The most rapid catalysis is associated with those bacteria capable of reducing nitrate and nitrite by the process of denitrification. The most significant clinical corollary of these studies is that although bacterial catalysis of N-nitrosation has been demonstrated unequivocally, bacterial colonization of the stomach may not itself necessarily result in elevated endogenous N-nitroso compound exposure despite the elevated nitrite concentrations normally associated with such colonization. An increase in exposure to endogenously formed N-nitroso compounds would only be predicted in those individuals where a significant proportion of the colonizing bacteria expressed significant N-nitrosation activity. As a consequence the carcinogenic risk may be restricted to only a small proportion of colonized individuals depending on the prevalence of sustained infection by bacteria with significant N-nitrosation activity, particularly denitrifiers.

Humans↗
PubMed1987

The effect of oral diltiazem on airway reactivity to methacholine and exercise in subjects with mild intermittent asthma.

The effect of increasing doses of oral diltiazem on airway reactivity to methacholine was evaluated in 10 volunteers with mild asthma. Then the highest tolerated dose was compared with placebo in preventing exercise-induced bronchoconstriction. Methacholine challenges were performed 1 h before and 100 min after placebo or after 30, 60, 90, 120, or 180 mg of oral diltiazem, given in a single-blind, crossover manner on different days within 2 wk. Diltiazem, at doses above 60 mg prolonged the P-R interval of the electrocardiograph but had no significant effect on FVC, FEV1, or FEF25-75. The mean +/- SEM ratio of the dose of methacholine required to produce a 20% decrease in FEV1 (PD20) after diltiazem to the PD20 before diltiazem, i.e., the fold increase in PD20, was not significantly different from placebo at any dose: 0.93 +/- 0.11 after placebo, 1.2 +/- 0.1 after 30 mg, 1.3 +/- 0.3 after 60 mg, 1.2 +/- 0.2 after 90 mg, 1.1 +/- 0.1 after 120 mg, and 1.0 +/- 0.1 after 180 mg. One hundred minutes before a standardized exercise challenge, 120 to 180 mg of oral diltiazem and identically appearing placebo tablets were administered in a randomized, double-blind, crossover design on separate days at least 48 h apart. The mean +/- SEM maximal postexercise decrease in FEV1 was 25.5 +/- 3.3% after placebo and 17.0 +/- 4.8% after diltiazem (p less than 0.01). There was no correlation between change in FEV1 and serum concentrations of diltiazem or its active metabolite desacetyldiltiazem.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Ultrasound appearance of extramedullary hematopoiesis.

Extramedullary hematopoiesis accompanies a wide variety of diseases and is defined as the abnormal production of blood outside the normal confines of the bone marrow. Most of the time, extramedullary hematopoiesis is found as microscopic foci in soft tissues; however, on occasion this process may reach a size that is detectable with ultrasound. Two forms are possible: "paraosseous"--in which the normal medullary tissue of the bone marrow ruptures through the bone to present as a paraosseous soft tissue mass,--and "extraosseous"--in which extramedullary hematopoiesis occurs within soft tissue. These "masses" of hematopoietic tissue can appear almost anywhere in the abdomen and pelvis and can mimic a wide variety of more serious diseases.

Adolescent↗