Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poor patient compliance is common in clinical practice but difficult to demonstrate to medical students in a convincing manner. To accomplish this, the authors asked medical students who preregistered for a conference on patient compliance to adopt the role of "patient" and to take "medication" (Vitamin C) for one week, to observe certain dietary restrictions, and to complete an attitude and health beliefs questionnaire. The educational impact was intensified by making prior predictions about outcome which were almost exactly confirmed. The predictions concerned failure to fill the prescription, extent and type of noncompliance, and significant differences in attitudes between compliant and noncompliant students. The attitudes of the students resembled those of noncompliant patients asked to take medication for nonsymptomatic disorders (such as hypertension). Those students who participated in the drug-taking experience rated the educational impact of the conference more highly than did those students who attended the conference but did not take part in the drug project.
 ...
PMID:Teaching medical students about treatment compliance. 68 59

Neurochemical changes in the extracellular fluid of the rostral ventrolateral medulla (RVLM) were produced by changes in arterial blood pressure. Blood pressure was raised or lowered with systemic infusions of phenylephrine or nitroprusside and neurochemicals were recovered from RVLM by in vivo microdialysis. A dialysis probe 300 microns in diameter and 500 microns in length was stereotaxically implanted in the RVLM of the urethane-anesthetized rat. Sterile physiological Ringer's solution was perfused at a rate of 1.5 microliter/min. The perfusate was collected under ice-cold conditions every 15 min for the assay of epinephrine, dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA), ascorbic acid, and uric acid. After stable baseline neurochemical concentrations were achieved, animals were infused with phenylephrine or nitroprusside intravenously to raise or lower the blood pressure. Increasing blood pressure 50 mm Hg above the baseline value by phenylephrine led to a significant reduction in heart rate and a reduction in extracellular epinephrine and DOPAC concentrations. The 5-HIAA concentration was increased during the hypertensive drug infusion. There were no changes in the concentrations of ascorbic acid or uric acid. Hypotension produced by nitroprusside (-20 mm Hg) led to neurochemical changes which were the reciprocal of those seen during hypertension. During hypotension, heart rate increased as did the extracellular fluid epinephrine concentration. The 5-HIAA concentration fell with hypotension and remained depressed following the nitroprusside infusion. Ascorbic acid and uric acid concentrations did not change during hypotension but ascorbic acid did increase after the nitroprusside infusion stopped. These data provide direct evidence that epinephrine release in RVLM is linked to changes in systemic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Drug-induced changes in blood pressure lead to changes in extracellular concentrations of epinephrine, dihydroxyphenylacetic acid, and 5-hydroxyindoleacetic acid in the rostral ventrolateral medulla of the rat. 137 44

Xerostomia, the subjective feeling of dry mouth, affects millions of people particularly the elderly. It is invariably associated with hypofunction of the salivary glands. The amount, rate of secretion, and composition of saliva are regulated by both sympathetic and parasympathetic receptor systems whose stimulation transmits signals through intracellular messengers (cations, nucleotides, phospholipid derivatives) to structures and enzymes within the cell. Salivary glands express a variety of cell-surface receptors including adrenergic (alpha and beta), muscarinic-cholinergic, substance P, vasoactive intestinal peptide hormone, and ATP receptors. Ascorbate which is present in salivary acinar cells in relatively high concentrations, is closely involved in many cellular functions including the metabolism of pyrimidines, intracellular calcium, the catecholamines and other neurotransmitters which regulate salivary gland exocytosis. Ascorbate-dependent carboxyl-terminal peptide alpha-amidation enzyme similar to the pituitary peptidyl-glycine alpha-amidating monooxygase, is also present in salivary glands. It is therefore not fortuitous that the seemingly unrelated numerous factors like aging, drug ingestion, pregnancy, smoking, ionizing radiation, stress, and various pathological states such as cancer, autoimmune disorders, diabetes mellitus, and hypertension often implicated in the causation of xerostomia, all promote increased tissue requirement for and/or depletion of ascorbate.
 ...
PMID:Ascorbate status and xerostomia. 143 93

The purpose of prescribing combined oral contraceptives (OCs) is achievement of good cycle control and effective contraception with the least side effects, using an OC with the lowest possible dose of estrogen. Triphasil, Triquilar, Nordette, Microgynon 30, and Brevinor are good 1st choices because of the low estrogen dose (30-35 mcg). Women who probably cannot tolerate breakthrough bleeding and who need simple packaging should use a monophasic, more progestogenic OC, e.g., Nordette or Microgynon 30. Physicians should suggest a low dose estrogen and low dose antiandrogenic progestogen (OC) (e.g., Diane-35 ED) for women who have acne. They should advise patients that when they take OCs, their menstrual periods usually become shorter, regular, and lighter. Women need not take a break from OC usage. Vitamin C, antibiotics, griseofulvin, rifampicin, and anticonvulsants (except sodium valproate) interact with OCs. Women using warfarin and oral hypoglycemics and wanting to start using OCs need to consult their physician about changing requirements for warfarin and oral hypoglycemics. The effectiveness of OCs can be diminished by diarrhea and vomiting. Absolute contraindications to OCs include pregnancy, use during the first 2 weeks postpartum, history of thromboembolism, undiagnosed abnormal vaginal bleeding, focal migraine, coronary heart disease, steroid-dependent tumors, recent impaired liver function, and cardiovascular accidents. Some relative contraindications are older than 35 years old and smoking, breast feeding, and hypertension. This article provides a section on how to manage common side effects. For example, if the side effect is acne, the physician should prescribe an OC with increased estrogen and reduced progestogen (e.g., Triphasil/Triquilar to Biphasil/Sequilar). This article lists trade names of various OCs and their estrogen and progestogen doses, e.g., Nordette has 30 mcg ethinyl estradiol and 150 mcg levonorgestrel.
 ...
PMID:Combined oral contraception. 147 9

The acute cardiovascular effects of intracisternal injections of 6-hydroxydopamine (6-OHDA), 5,6-dihydroxytryptamine and 5,7-dihydroxytryptamine and the degree of neurotransmitter depletion achieved by such injections were studied. The two different vehicles used--0.2% ascorbic acid in 0.9% NaCl, or 0.9% NaCl--had little effect on the cardiovascular response to 6-OHDA injections but had a striking effect on levels of noradrenaline (NA) subsequently measured in the thoracic spinal cord. 6-OHDA (600 micrograms kg-1 free base) dissolved in normal saline depleted spinal cord NA to less than 1% of control levels whereas the same dose of 6-OHDA dissolved in ascorbate saline only depleted spinal cord NA to 24% of control levels. The degree of depletion of NA in medulla, pons and hypothalamus was similar in the two groups. Ascorbic acid also appeared to contribute to the non-specific toxicity of intracisternal injections of 6-OHDA. The hypertension and bradycardia that followed lesions of the ventrolateral medulla coinciding with the A1 group of noradrenergic cells (Al lesions) were attenuated in animals in which spinal cord NA had been depleted to 2% of control using 6-OHDA in normal saline. However, pretreatment with 6-OHDA in ascorbate saline, which only reduced spinal cord NA to 23% of control, had no effect on the cardiovascular response to Al lesions. It seems likely that the effects of Al lesions are mediated, at least in part, by NA projections descending within the spinal cord.
 ...
PMID:Cardiovascular effects of intracisternal 6-hydroxydopamine and of subsequent lesions of the ventrolateral medulla coinciding with the Al group of noradrenaline cells in the rabbit. 392 89

Throughout adult life, there is progressive alteration in body composition and tissue function. There is loss of lean body mass, notably by muscle, with a gain in body fat. We do not know whether nutritional factors affect these gross changes. In the case of loss of bone density (osteoporosis), however, there is evidence that the process is retarded by raising the intake of calcium and by exercise. Aging also adversely affects tissue function at the level of the whole organ and tissue as well as at the cellular and subcellular level. Animal models show similar age-related changes, and demonstrate further that alterations in nutrient intake or exercise can alter the rate of loss of tissue and cellular function. In addition to the effects of adult aging on tissue function, certain chronic diseases and disabilities are related to aging. These conditions include atherosclerosis, hypertension, coronary thrombosis, cancer, etc. Both human epidemiological studies and animal experiments on aging suggest strongly that nutrition plays a role in the onset and development of these conditions. There is a need for more accurate assessments of the nutrient needs of people over 65 years of age. A few selected nutrients are discussed. Studies of energy intake during adult life show a progressive reduction with increasing age, due mainly to reduced physical activity. Vitamin C levels in the white blood cells of elderly women can be half those of young adults; these respond to supplementary vitamin C without evidence of clinical benefit. Nitrogen balance studies suggest that the allowance of protein for older adults is not less than for young. Finally, surveys of elderly in whole populations and in selected groups show that, by the nutritional standards of young adults, there may exist a significant amount of malnutrition in people as they grow old, though we do not know whether this affects rate of loss of tissue function with age.
 ...
PMID:Nutrition and the elderly: a general overview. 650 37

General health and nutritional status of 167 free-living elderly Greek (aged 65-91 years) were assessed. The most prevalent diseases/symptoms encountered were related to respiratory, gastrointestinal, musculoskeletal and vascular systems (hypertension). Most subjects were socially active. Body mass index was < 20 and > 25 Kg/m2 in 7 and 57% of the subjects, respectively. Systolic blood pressure was significantly higher in women than in men, and as a group, 18 and 42%, respectively, had diastolic blood pressures > 90 and systolic blood pressures > 160 mmHg. Anemia and hypoalbuminemia were detected in < 5% of the population. Total fat intake was 40-45% of total energy intake and most of it came from monounsaturated fat. Hypercholesterolemia (> 6 mmol/L) was present in 32% of subjects. The percentages of men who smoked (66%) or drank (68%) were significantly higher than those of women (2 and 1%, respectively). Dietary intake data were compared with US recommended dietary allowances (RDA) for elderly. Daily energy and protein intakes were lower than the US RDA levels; calcium intake was > 50% of the US RDA, while magnesium and vitamin B6 levels were < 50% of the US RDA. Vitamin C intake was much higher than that of the US RDA. Mean thiamin, vitamin A, riboflavin and iron intakes were below the US RDA, while fiber intake was < 50% of the corresponding US estimate. Phosphorus was higher than the US RDA in men, while lower for women. Sodium intakes exceeded those recommended, while potassium levels were higher than those recommended in males, and lower in females.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Nutrition status of the elderly in Anogia, Crete, Greece. 829 24

For proper use of systemic GCS, a basic knowledge of the normal HPA axis, as well as knowledge of the pharmacology, clinical usage guidelines, and adverse reactions of these agents is imperative. Both short-term (acute) and long-term side effects should be well known by the physician. The pros and cons of oral and parenteral therapy for various disorders and in various situations should be recognized. For long-term therapy, an intermediate-acting agent such as prednisone in single, early morning doses is most commonly used to minimize suppression of the HPA axis. Alternate-morning doses produce even less suppression if the disease process will respond. A through patient history, including general medical history and medications the patient is taking, is important to anticipate any potential problems. Weight and blood pressure should be checked initially and every 1 to 3 months thereafter. Blood glucose, electrolytes, and lipid studies, including triglycerides, should be done approximately every 6 months. An ophthalmology examination should be performed every year, and stool examination for occult blood and chest radiography can be obtained as indicated. Bone density studies might be necessary in patients who are at high risk for osteoporosis. Specific acute situations may dictate other studies. The patient on long-term GCS should be kept as active as possible, as mild-to-moderate exercise helps prevent certain side effects, such as osteoporosis. The dose of oral GCS is best given with food to prevent gastrointestinal irritation, and agents to decrease gastric acidity might be needed in certain situations. Exposure to infections should be prevented, where possible, and treatment initiated at the first sign of systemic or cutaneous infection. Pain should be evaluated early, especially abdominal pain or bone pain; MRI is indicated if aseptic necrosis of bone is suspected. Both trauma and severe sun exposure should be avoided. Consultation with other specialists is strongly recommended when the situation dictates. Diet is one of the most important strategies to minimize side effects from long-term GCS therapy. Vegetable protein should be increased in the diet, and fats and carbohydrates limited. Adequate calcium is imperative, and calcium supplementation is recommended for high-risk osteoporosis patients. Small amounts of vitamin D may be necessary to increase absorption of calcium. Restriction of sodium is also important, as is maintainance of dietary potassium. Supplemental potassium may be necessary in some patients, and a thiazide diuretic might be useful in patients with hypertension, edema, or osteoporosis. Vitamin C can be given to promote wound healing. A good doctor-patient relationship is important in managing the patient on long-term GCS. The patient must return for regular visits and be encouraged to promptly report any adverse reactions to the physician. If these criteria are maintained and the strategies noted previously are followed, problems from long-term therapy with GCS will be minimized.
 ...
PMID:Minimizing complications from systemic glucocorticosteroid use. 878 96

Oxidative stress has been implicated as an important etiologic factor in atherosclerosis and vascular dysfunction. Antioxidants may inhibit atherogenesis and improve vascular function by two different mechanisms. First, lipid-soluble antioxidants present in low-density lipoprotein (LDL), including alpha-tocopherol, and water-soluble antioxidants present in the extracellular fluid of the arterial wall, including ascorbic acid (vitamin C), inhibit LDL oxidation through an LDL-specific antioxidant action. Second, antioxidants present in the cells of the vascular wall decrease cellular production and release of reactive oxygen species (ROS), inhibit endothelial activation (i.e., expression of adhesion molecules and monocyte chemoattractants), and improve the biologic activity of endothelium-derived nitric oxide (EDNO) through a cell- or tissue-specific antioxidant action. alpha-Tocopherol and a number of thiol antioxidants have been shown to decrease adhesion molecule expression and monocyte-endothelial interactions. Vitamin C has been demonstrated to potentiate EDNO activity and normalize vascular function in patients with coronary artery disease and associated risk factors, including hypercholesterolemia, hyperhomocysteinemia, hypertension, diabetes, and smoking.
 ...
PMID:On the role of vitamin C and other antioxidants in atherogenesis and vascular dysfunction. 1060 78

Increased production of superoxide anion may contribute to impaired bioactivity of endothelium-derived nitric oxide in hypertension. Ascorbic acid is capable of scavenging superoxide anion; however, experimental studies have shown that high physiological concentrations (>1 mmol/L) of ascorbic acid are required to prevent superoxide-mediated vascular dysfunction. To seek kinetic evidence that superoxide anion contributes to endothelial vasomotor dysfunction in human hypertension, we examined the effects of 2.4 or 24 mg/min ascorbic acid intra-arterial infusions on forearm blood flow responses to methacholine or sodium nitroprusside in 30 patients with hypertension and 22 age-matched controls. Endothelium-dependent vasodilation to methacholine was significantly impaired in the hypertensive patients, with a response to the highest dose of methacholine (10 microg/min) of 12.3+/-6.7 compared with 16.1+/-5.8 mL. min(-1). dL tissue(-1) in the controls (P<0.001). The response to sodium nitroprusside was equivalent in the 2 groups. Ascorbic acid at 24 mg/min significantly improved the forearm blood flow response to methacholine in hypertensive patients with a peak response of 16.1+/-7.1 mL. min(-1). dL tissue(-1) (P=0.001). This dose produced a cephalic vein ascorbic acid concentration of 3.2+/-1. 4 mmol/L. In contrast, ascorbic acid at 2.4 mg/min had no effect on the methacholine response. Ascorbic acid at both doses had no effect on the vasodilator response to sodium nitroprusside in hypertensive patients or the methacholine response in the controls. These results agree with the predicted kinetics for superoxide anion-mediated impairment of endothelium-derived nitric oxide action. Thus, superoxide anion may contribute to impaired endothelium-dependent vasodilation in patients with hypertension.
Hypertension 2000 Apr
PMID:Pharmacological concentrations of ascorbic acid are required for the beneficial effect on endothelial vasomotor function in hypertension. 1077 65


1 2 3 4 5 6 7 Next >>