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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifty-eight normal subjects and 51 subjects with borderline hypertension underwent microvascular and hemodynamic studies while on an ad libitum diet and during periods of sodium depletion (10 mEq/day) and repletion (200 mEq/day). Hemodynamic measurements included arterial blood pressure, cardiac index, total peripheral resistance, forearm blood flow, vascular resistance, venous compliance, and capillary filtration fraction. Studies of the microcirculation consisted of macrophotography of the bulbar conjunctiva with measurement of anteriolar, venular, and capillary density and diameter. During sodium repletion, cardiac index increased significantly in the normal subjects (2.35 +/- 0.7 vs 2.44 +/- 0.7 L/min/m2; p less than 0.01) and in the borderline hypertensive subjects (2.50 +/- 0.7 vs 2.70 +/- 0.8 L/min/m2; p less than 0.01). However, mean blood pressure rose by more than 5% in only 33 subjects, 13 with normal and 20 with borderline hypertension. When these sodium-sensitive subjects were compared with those whose blood pressure did not rise, the former were found to have significantly higher forearm vascular resistance (32.2 +/- 21 vs 17.9 +/- 12 mm Hg/ml/min/100 g; p less than 0.01), lower forearm blood flow (4.42 +/- 2.7 vs 7.47 +/- 5.0 ml/min/100 g) and lower conjunctival capillary density (3.72 +/- 1.7 vs 5.18 +/- 2.1 [SD] mm/mm2; p less than 0.05). These results indicate that sodium sensitivity in humans is accompanied by elevation of forearm vascular resistance and attenuation of the microcirculation.
Hypertension 1987 Apr
PMID:Hemodynamic characteristics of sodium-sensitive human subjects. 355 5

In the prospective Basel longitudinal study on aging (1955-1978) 123 men (age at entry from 6-61 years) were investigated in 2 year (average) intervals. Complete case histories are available on 67 subjects over the entire period (19.6 +/- 0.85 years). Part I of the study was to confirm the hypothesis of Bernstein and of Steinhaus, according to which life expectancy can be estimated from the speed of development of presbyopia. Parallel to the measurement of accommodation range (after preliminary determination of refraction and visual acuity), the development of height, body weight, vital capacity, expiratory volume, chest circumference, abdominal circumference, blood pressure, ECG and pulse wave velocity were measured. Invasive investigations were not undertaken. Only when hypertension was combined with obesity was the diminution of accommodation range striking (Fig. 10c; however there were only 3 subjects in this risk group). Taking everything into consideration there was a concomitance between decrease of accommodation range and changes of medical parameters (Table 6). Intercurrent illness did not influence the accommodation range. Longitudinal measurements and cross-sectional comparisons (data averaged to the same point as of the same age) were carried out. The results did not always coincide. We could not confirm the hypothesis of Bernstein and of Steinhaus. In Part II the results of the objective measurements are given. Apparently growth of the skull does not stop entirely. The increase of interpupillary distance can be complete at 17 years of age, but also can continue to the 30th year. The palpebral fissure increases an average of 3 mm more horizontally between the 6th and the 20th year of life. The corneal diameter remains constant in all age classes, that is, the growth of the cornea should be complete before the 6th year of life. Early arcus senilis changes are found already in the 20-year-old. The increase in the course of time of arcus senilis is obvious, it is most pronounced in obese hypertensives. Still there are persons who at 65 years of age show no arcus senilis. In the 20th year degenerative deposits in the conjunctiva begin. They increase in number and above the 60th year all subjects showed degenerative deposits. Aqueous veins are less visible in younger subjects. With increasing age--as a result of degenerative thinning of the conjunctiva--they are recognizable in ever greater numbers. The depth of the anterior chamber attains its greatest extent between the 20th and the 30th year.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The Basel longitudinal study on aging (1955-1978). Ophthalmo-gerontological research results. 362 22

Studies on microcirculation in the elderly include observations in the small vessels of the bulbar conjunctiva and of the nailbed with respect to a classification of the findings according to a number of semeiologic criteria (diameter and shape alterations, terminal capillary network, intravascular red cell aggregation). In vascular diseases of the elderly there are typical alterations of the capillaroscopic findings in the bulbar conjunctiva and in the nailbed, particularly in cases of arteriosclerosis, arterial hypertension, diabetic microangiopathy, heart failure, ischemic myocardiopathies. During the treatment with some vasoactive drugs (nicotinic acid and its derivatives, buflomedil, CPD-choline) there are marked modifications of the small conjunctival vessels, with evident dilatations, appearance of collaterals, increased homogeneity of the blood flow, better evidence of the capillary network and reduction of intravascular red cell aggregation.
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PMID:Microcirculation in the elderly. 383 Nov 49

The authors present two cases of large meningiomas of the lateral ventricle. In both cases the first diagnosis of the disease was cerebral ischaemia. Tumours did not produce symptome of intracranial hypertension, and the most common symptoms of these tumours - hemianopia and papilloedema - were also not observed. Both tumours did not originate from the choroid plexus, probably developing from the tela conjunctiva of the vessels.
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PMID:Meningiomas of the lateral ventricle. 405 35

Complications from mydriatic and cycloplegic drugs are rare compared with their extensive use. Adverse effects are often related to dosage or other factors. The ocular complications include increased intraocular pressure, pigmentation of the conjunctiva and cornea, pigment in the anterior chamber, lacrimal duct blockage, macular edema, corneal endothelium damage, hyperemia, allergy, discomfort, and blurred vision. The systemic complications are those common to sympathomimetic and parasympatholytic drugs and include tachycardia, hypertension, headache, faintness. pallor, trembling, excessive sweating, palpitations, arrhythmias, confusion, hallucinations, drowsiness, ataxia, flushed skin, high fever, dysarthria, thirst, dry mouth, convulsions, disorientation, nervousness, coma, and death. An understanding of all possible side effects is of paramount importance to those using these drugs in the treatment of anticholinesterase poisoning. This review is intended as a ready reference to the adverse effects of mydriatic and cycloplegic drugs.
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PMID:Mydriatic and cycloplegic drugs: a review of ocular and systemic complications. 703 29

Biomicroscopy was used to study microcirculation in the area of bulbar conjunctiva in 124 patients suffering from hypertension and in 45 healthy individuals aged 30-74 years. It was found that the form of the microvessels especially of the capillaries and venules is modified with age. The degree of such changes is enhanced in arterial hypertension in patients of all the age groups but it is more marked in the more aged.
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PMID:[Age-related characteristics of the conjunctival microcirculation in healthy persons and hypertensives]. 707 4

An autopsy-based study was made of the microcirculatory bed (MCB) of human heart in ischemic heart disease and arterial hypertension in an age-related aspect. Changes in MCB and its time course were studied in experimental models. On the basis of the studies done and data from the published literature we elaborated a morphological classification of MCB which include the following stages: compensatory; initial pathologic changes with the adaptation being maintained at the same level as before; profound pathological changes at the background of lowered adaptation; decompensation. The classification outlined above may be used in examining autopsy and biopsy material (experimental or perioperative) as well as in clinical investigations designed to study the nail bed, bulbar, conjunctiva, rectal mucous membrane. Investigation into MCB changes will enable us to properly assess adaptive potential and prescribe pathogenically substantiated surgical, internal or complex health resort treatment.
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PMID:[The clinico-morphological classification of changes in the microcirculatory bed]. 807 21

Arterial hypertension is known to be an important risk factor for cerebral and cardiovascular disease. Previous studies in rats have demonstrated that changes in both capillary density and vessel diameter may contribute to increased vascular resistance in hypertension. In vivo studies of human subjects with essential hypertension revealed a reduction in the number of arterioles in the skin and conjunctiva; no other in vivo data are available from other tissues. By means of a new imaging technique, capillary density and capillary blood flow velocity can now be assessed in the human retina. We undertook the present investigation to determine whether patients with essential hypertension and only minor clinical retinal vascular alterations have decreased retinal capillary density and altered capillary flow velocity. Seventeen hypertensive patients with only minor retinal vascular alterations and 17 healthy volunteers matched for age were selected. All study participants underwent ophthalmologic examination and fluorescein angiographic studies by means of scanning laser ophthalmoscopy. Capillary density and capillary blood flow velocity in the perifoveal network were evaluated from the angiograms. The retinal microcirculation in the perifoveal capillary network of hypertensive patients showed significant alterations. Both the capillary density and capillary flow velocities were significantly reduced compared with the control group. For the first time alterations of capillary blood flow and capillary density in a vascular network very similar to that of the brain have been demonstrated in hypertensive patients in vivo. Further studies with this technique may help identify patients at high risk for cerebrovascular diseases.
Hypertension 1994 Apr
PMID:Quantification of retinal capillary density and flow velocity in patients with essential hypertension. 814 16

In order to investigate the aging changes of the conjunctiva, we examined fluorescein-positive areas by fluorescein angiography. The deposition of melanin in basal cells, the degranulation of mast cells, and the lumens of capillaries were examined by light microscopy in 35 cataractous eyes without diabetes or hypertension. The fluorescein leakage increased with aging. The number of basal cells with deposition of melanin granules and mast cells with degranulation correlated significantly with aging. On the other hand, the narrowing of capillary lumens in conjunctival stroma was not observed with aging. Based on the above results, we conclude that the weakness of the conjunctival vessels without the narrowing of capillary lumens might be caused by functional disorder of the endothelium and pericytes. The increase of deposition of melanin granules in basal cells may be caused by the breakdown of the metabolic pathway of melanin. Long-time mechanical stimuli and metabolic disorders of active substances may increase the degranulation of mast cells.
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PMID:[Aging changes in conjunctiva visualized by fluorescein angiography and histopathology]. 864 42

Exfoliation syndrome (XFS) is an age-related disease in which abnormal fibrillar extracellular material is produced and accumulates in many ocular tissues. Its ocular manifestations involve all of the structures of the anterior segment, as well as conjunctiva and orbital structures. Glaucoma occurs more commonly in eyes with XFS than in those without it; in fact, XFS has recently been recognized as the most common identifiable cause of glaucoma. Patients with XFS are also predisposed to develop angle-closure glaucoma, and glaucoma in XFS has a more serious clinical course and worse prognosis than primary open-angle glaucoma. There is increasing evidence for an etiological association of XFS with cataract formation, and possibly with retinal vein occlusion. XFS is now suspected to be a systemic disorder and has been associated preliminarily with transient ischemic attacks, stroke, systemic hypertension, and myocardial infarction. Further ramifications await discovery. Deposits of white material on the anterior lens surface are the most consistent and important diagnostic feature of XFS. The classic pattern consists of three distinct zones that become visible when the pupil is fully dilated. Whereas the classic picture of manifest XFS has been often described, the early stages of beginning exfoliation have not been well defined. Next to the lens, exfoliation material is most prominent at the pupillary border. Pigment loss from the iris sphincter region and its deposition on anterior chamber structures is a hallmark of XFS. Despite extensive research, the exact chemical composition of exfoliation material (XFM) remains unknown. An overproduction and abnormal metabolism of glycosaminoglycans have been suggested as one of the key changes in XFS. The protein components of XFM include both noncollagenous basement membrane components and epitopes of the elastic fiber system such as fibrillium. Regardless of etiology, typical exfoliation fibers have been demonstrated electron microscopically in close association with the pre-equatorial lens epithelium, the nonpigmented ciliary epithelium, the iris pigment epithelium, the corneal endothelium, the trabecular endothelium, and with almost all cell types of the iris stroma, such as fibrocytes, melanocytes, vascular endothelial cells, pericytes, and smooth muscle cells. The presence of XFS should alert the physician to the increased risks of intraocular surgery, most commonly zonular dehiscence, capsular rupture, and vitreous loss during cataract extraction. Heightened awareness of this condition and its associated clinical signs are important in the detection and management of glaucoma, and preoperative determination of those patients at increased risk for surgical complications.
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PMID:Exfoliation syndrome. 1116 42


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