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Biomedical subjects

C L Johnson

Publications and source records attributed to C L Johnson.

At least 145 records · Page 8Linked to original sources
PubMed1987

The effect of various dose regimens of famotidine on basal nocturnal and meal-stimulated gastric secretion.

The antisecretory profile of the H2-receptor antagonist famotidine was studied with various oral doses and regimens in 10 healthy volunteers with high basal acid output (greater than or equal to 5 mEq/hr). Doses included 10, 20, and 40 mg at 9 PM and 9 AM and also 40 mg at 9 PM only. In the 22 hours after the PM doses, overnight (midnight to 7 AM) basal acid secretion was evaluated. Daytime meal-stimulated secretion was assessed at 7 AM, 12 noon, and 5 PM. Doses of 10, 20, and 40 mg inhibited fasting nocturnal basal secretion by 69%, 86%, and 83% to 94%, respectively (P less than 0.01). Meal-stimulated secretion at 7 AM (10 hours after administration) was inhibited by 28% and 39% (P less than 0.01) by only the 40 mg doses. The response to the 12 noon meal was inhibited by the 9 AM doses of 10, 20, and 40 mg by 45%, 75%, and 85%, respectively (P less than 0.01). The effect of a 40 mg dose given at 9 PM only had dissipated by breakfast (7 AM). The response to the 5 PM meal was suppressed by the 20 and 40 mg doses given at 9 AM by 22% and 35%, respectively (P less than 0.05). Suppression was present in only eight of the subjects after the 20 mg dose but in all 10 after the 40 mg dose. The effect on basal gastric aspirate pH values paralleled those seen on acid output. An association was found between mean plasma concentrations of famotidine and mean inhibition of meal-stimulated acid secretion. However, individual values may not be predictive.

Adult↗
PubMed1987

Comparison of dietary intakes and iron status of vitamin-mineral supplement users and nonusers, aged 1-19 years.

Despite widespread use of supplements, few studies have been conducted to determine if supplement users have better nutritional status. Using data from the second National Health and Nutrition Examination Survey (NHANES II), mean values of five iron status indicators (hemoglobin, mean corpuscular volume, transferrin saturation, erythrocyte protoporphyrin, and serum ferritin) and dietary intakes of several nutrients and food groups were compared between regular supplement users and nonusers aged 1-19 y. Users consumed more vitamin C and fruits and vegetables than nonusers in several age-sex groups. No significant differences in mean Fe status indicator values were observed except for hemoglobin for the 3-4-y olds and serum ferritin for the 5-10-y olds. In both cases, users had higher values than nonusers. In general, Fe status was not associated with supplement use but the reason cannot be identified from this survey.

Adolescent↗
PubMed1987

Acquired loss of red cell Kell antigens.

A 19-year-old patient with a long history of idiopathic thrombocytopenic purpura developed a potent antibody against a high-incidence antigen in the Kell blood group system. The direct antiglobulin test on his red cells was negative. His cells exhibited profound depression of Kell blood group antigens, but antigens of other blood groups were normal. Transfusion of incompatible blood was well tolerated and differential agglutination tests, using selected Rh antisera, showed in vivo survival of the transfused red cells for more than 8 weeks. However, the transfused red cells also showed acquired loss of Kell antigens. Five months after the initial findings, Kell-related antibody disappeared and Kell antigens reappeared on his red cells. The patient's serum stored from the initial investigation now reacted with his freshly collected red cells. These data suggest that an environmental agent in the patient's plasma was responsible for the temporary loss of Kell antigens from red cells in his circulation.

Adult↗
PubMed1987

The relationship between the binding site of [3H]-d-cis-diltiazem and that of other non-dihydropyridine calcium entry blockers in cardiac sarcolemma.

[3H]-d-cis-Diltiazem binds to canine cardiac sarcolemma in a specific, saturable, and reversible manner with a KD = 58.0 +/- 9.5 nM and a receptor site density (maximum binding) of 2.19 +/- 0.24 pmol/mg of protein. Bepridil and verapamil, Ca2+ channel inhibitors, can completely inhibit this binding at nM concentrations. This inhibition was determined from saturation binding data to be due to a change in affinity of the radioligand, suggesting a competitive interaction between the three drugs. However, in dissociation experiments, both bepridil and verapamil increased the dissociation rate of the radioligand. This effect is uncharacteristic of competitive inhibitors and suggests that bepridil and verapamil regulate [3H]-d-cis-diltiazem binding in a negative allosteric fashion through their own distinct binding sites.

Allosteric Regulation↗
PubMed1986

Arthroscopic meniscal repair evaluated with repeat arthroscopy.

Arthroscopic meniscal repair is a technically feasible approach to the treatment of meniscal tears in young active individuals. To evaluate this premise, we repaired 29 minisci in 27 patients and then arthroscoped their knees 3 months later. Repairs were limited to displaceable longitudinal tears. In 16 patients ligaments were intact. Eleven patients were anterior cruciate ligament deficient, six of whom underwent concomitant ACL reconstructions. In two patients, bicompartmental tears were encountered. Under arthroscopic control, using curved cannulae, horizontal mattress sutures of absorbable monofilament were placed across the tear, out through the capsule, and tied over the fascia, deep to the skin. No arthrotomies were performed, and all portions of the menisci could be reached with this method. Twenty-four of 29 repairs healed completely; 5 healed partially (30 to 50% healing). Four of the five failed repairs occurred in unstable anterior cruciate ligament deficient knees.

Adolescent↗
PubMed1986

Acquired loss of red-cell Wj antigen in a patient with Hodgkin's disease.

A patient with Hodgkin's disease became temporarily Wj-negative with alloanti-Wj in his serum. Four human autoantibodies, and 1 of 2 murine monoclonal antibodies, with serological characteristics of anti-Wj were nonreactive with his red cells, confirming that they have anti-Wj specificity. Six siblings of the patient are all Wj-positive. The patient was also temporarily Anton-negative, and cross-testing between Wj and Anton red cells and antisera showed mutual compatibility, indicating that the antigens are the same. The patient and 3 of his 6 siblings are also of the rare Lu: - 13 phenotype, providing the first evidence that this is an inherited characteristic.

Adult↗
PubMed1985

Effects of dimaprit on growth and differentiation of human promyelocytic cell line, HL-60.

The human promyelocytic cell line HL-60, differentiates in response to a variety of agents including dibutyryl cAMP and agents which increase intracellular cAMP concentrations (phosphodiesterase inhibitors, PGE2, and cholera toxin). HL-60 is also known to be rich in H2 -histamine sensitive adenylate cyclase activity. The present study was therefore designed to test the effects of H2-stimulation on growth and differentiation of HL-60 using the potent H2 agonist dimaprit. Dimaprit markedly increased cAMP production in a dose-dependent manner reaching maximal levels after 30-60 minutes. Intracellular cAMP levels decreased thereafter and by 24 hours were approximately 2-3 fold increased above control. Intracellular cAMP levels were not altered by dimaprit (10(-7)M to 10(-4)M) at 4 days in culture compared to either untreated HL-60 cells or dimethylsulfoxide (DMSO) (1.3%) treated cells. While exponential growth was unaltered by dimaprit (10(-7)M to 10(-4)M) as compared to control, dimaprit induced i) morphologic maturation to the myelocyte and metamyelocyte form with no differentiation seen beyond the metamyelocyte even after 6 days in culture, ii) increased NBT reductase activity and iii) dose-dependent increase in lysozyme activity which could be completely blocked by cimetidine, a specific H2 antagonist. Dimaprit-induced differentiation of HL-60 cells was associated with an initial but transient increase in intracellular cAMP production. Maturation beyond the metamyelocyte stage was not observed. Acquisition of NBT reductase and lysozyme activity correlated with morphologic maturation.

Bone Marrow↗
PubMed1985

Bulimia: multivariate predictors of life impairment.

The current study investigated the ability to predict life impairment in a group of women who reported frequent binge eating episodes. Results indicated that a combination of feeling out of control when binge eating, frequent binge episodes, frequent use of laxatives for weight control, plus early age at onset, guilt feelings after binging, and a history of low weight best predicted life impairment. Implications of these findings are discussed with respect to refining DSM-III criteria for bulimia.

Adaptation, Psychological↗
PubMed1985

Sulindac and ibuprofen inhibit furosemide-stimulated renin release but not natriuresis in men on a normal sodium diet.

We compared the effect of two commonly prescribed nonsteroidal anti-inflammatory drugs, ibuprofen and sulindac, and placebo on intravenous furosemide-induced natriuresis and renin stimulation in 11 healthy male volunteers, consuming a 100 mEq sodium, 80 mEq potassium diet. Chronic (6-day) therapy with each agent was followed by a 1-week washout period. There were no significant treatment-related differences in either urine volume or sodium excretion for any of the designated collection periods or for the cumulative value for the 4 h after furosemide administration. Similarly, differences among groups were not observed for creatinine clearance, urinary potassium and urinary chloride excretion. Mean basal plasma renin activity levels prior to furosemide administration on day 6 were significantly lower in the presence of ibuprofen (1.5 +/- 2.0 ng/ml/h;p less than 0.01) and sulindac (2,3 +/- 0.9 ng/ml/h; p less than 0.05), compared with placebo (3.3 +/- 1.1 ng/ml/h); the difference between the two NSAIDs was also significant (p less than 0.05). Mean plasma renin activity levels in the 4 h after furosemide increased significantly at all time points in comparison to basal values, but were significantly less for ibuprofen and sulindac groups in the first hour. Our data suggest that the natriuresis following intravenous furosemide in men consuming a normal sodium intake is not prostaglandin-dependent. Furthermore, the observation that sulindac suppressed basal and stimulated plasma renin activity levels, albeit to a lesser extent than ibuprofen, questions the claim that sulindac "spares' the kidney and compels further evaluation of this issue.

Adult↗
PubMed1984

Strategic feeding of high yielding dairy cows.

Computerised management schemes are widely used in British dairy herds yet the standardised lactation curves might not be the most appropriate in particular herds. The shape of these curves is more a reflection of feeding than lactational physiology. Experimental evidence supports the approach of prediction of yield potential for each cow in early lactation, the mean rate of fall for the herd and appropriately tailored feeding. Daily pattern of supplementary feeding interacts with body energy balance and might have implications in the incidence of metabolic diseases and infertility. Compositional quality and total yields of milk constituents are influenced by the level of nutrition used at the onset of each lactation.

Animal Nutritional Physiological Phenomena↗
PubMed1984

Operative management of thyroid disease. Technical considerations in a residency training program.

Experience with 294 thyroid operations at Medical Center Hospital as performed by resident housestaff in general surgery has been reported. Operative results were consistent with the morbidity and mortality figures from large reviews. The importance of an active role for surgical housestaff in the operative management of thyroid disease is emphasized. With close supervision and attention to intraoperative identification of the recurrent laryngeal nerves and parathyroid glands, satisfactory results can be achieved.

Adult↗
PubMed1984

Effects of sulindac and indomethacin on renal prostaglandin synthesis.

We compared the effects of sulindac and indomethacin, the effects of two nonsteroidal anti-inflammatory drugs, on renal prostaglandin synthesis and renal function. Sulindac, 200 mg twice daily, indomethacin, 25 mg four times a day, or placebo were taken by 15 normal female subjects (five in each of three treatment groups). Indomethacin decreased renal excretion of prostaglandins PGE2, PGF2 alpha, and 6-keto-PGF1 alpha, but sulindac and placebo had no effect on renal prostaglandin excretion. Concomitant with the reduction of renal prostaglandin synthesis in the indomethacin group, sodium and chloride excretion decreased; sulindac and placebo had no discernible effects on urine electrolytes. Extrarenal cyclooxygenase activity, as assessed by platelet thromboxane beta 2 release, was inhibited by both sulindac and indomethacin. Plasma renin activity and plasma aldosterone levels fell in all groups as a result of positive sodium balance, but the decrements of aldosterone were greater after indomethacin and sulindac. None of the treatments altered glomerular filtration rate or renal plasma flow in these normal women. We conclude that in normal women renal prostaglandin synthesis and prostaglandin-dependent tubular functions such as Na and Cl reabsorption are relatively unaffected by doses of sulindac (200 mg twice daily) that inhibit nonrenal cyclooxygenase. This may reflect the capacity of oxidative enzymes in the kidney to convert the active sulfide metabolite of sulindac to the inactive prodrug sulindac sulfoxide.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Physical therapists as scar modifiers.

Hypertrophic scars, a common sequelae to burn injuries, represent an overgrowth of dermal components like collagen. To the burn-injured patient, the red, raised, rigid scars represent impaired function and distorted appearance. Physical therapists modify scars by treating with pressure and stretching to minimize the devastating effects. Healing time, location of the injury, condition of the unhealed and healed areas, and treatment cost influence physical therapy. This article describes scarring and provides practical guidelines for pressure materials and stretching techniques. With an appropriate program, caring for a patient with burns becomes extremely beneficial and rewarding.

Adult↗
PubMed1984

Treatment of bulimia with brief psychoeducational group therapy.

Two groups of 10 normal-weight bulimic women received short-term, structured group treatment beginning 3 weeks apart in a multiple baseline design. The multifaceted treatment approach incorporated education, self-monitoring, goal setting, assertion training, relaxation, and cognitive restructuring. Results showed an overall reduction of 70% in binge/purge episodes. There were significant improvements in psychological functioning, including self-esteem, depression, assertiveness, and pathological attitudes about eating.

Adult↗
PubMed1984

Grasp and pinch strength in children 5 to 12 years old.

The objective of this study was to establish normative data concerning grasp and pinch strength for use by clinicians who are treating children with hand problems. A population of 474 children ages 5 to 12 were tested using the Jamar dynamometer and the Preston pinch guage. Means and standard deviations of all measurements for all subjects were determined. Results of the study indicate that there is a steady increase in both grasp and pinch strength that coincides with the increase in chronological age and development; males are consistently stronger than females across the age range in all tests, although the differences are not striking. Hand dominance was judged not to be an important factor in predicting strength in this population.

Adolescent↗
PubMed1984

Histamine H2 receptor desensitization in HL-60 human promyelocytic leukemia cells.

Recent studies have suggested that cyclic AMP (cAMP) may be involved in regulation of cell growth and differentiation of cancer cells. Incubating HL-60 cells in the presence of the specific H2 agonist dimaprit resulted in 30-fold increases in cAMP levels (EC50 = 5.7 X 10(-6) M) and morphological changes suggestive of cell maturation along the granulocyte pathway. However, cells cultured with 10(-5) M dimaprit showed more than an 80% decrease in their cAMP response to subsequent addition of H2 agonists, whereas the cAMP response to prostaglandin E2 was unaltered. Desensitization was time-dependent (halftime approximately 2.5 hr with 10(-5) M dimaprit), dose-dependent (dimaprit EC50 = 1.4 X 10(-6) M) and completely prevented by 10(-3) M cimetidine. Desensitization of HL-60 cells for 4 hr with 10(-5) M dimaprit followed by the addition of 10(-3) M cimetidine resulted in total recovery of the cAMP response in less than 24 hr. The pharmacologically inactive analog N-methyldimaprit (SK&F 92054) did not increase cAMP production or cause desensitization to H2 stimulation. Desensitization was observed in the presence or absence of a phosphodiesterase inhibitor, indicating that induction of cAMP-phosphodiesterase was not involved in this process. No difference in the number of [3H]tiotidine binding sites was observed between control and dimaprit-desensitized HL-60 cells. Based on these results, we suggest that H2 receptor agonists caused an agonist-dependent desensitization, presumably due to an uncoupling of receptors from adenylate cyclase.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗