Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0595921 (intraocular pressure)
 11,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of intraperitoneal injections of dipyridamole on the elevations of intraocular pressure and anterior chamber aqueous humor protein produced by topical application of prostaglandin E2 was studied in rabbits. Pretreatment with 100 mg/kg dipyridamole inhibited the prostaglandin E2--induced ocular hypertension and rise of aqueous humor protein. Systemic administration of dipyridamole did not alter the responses of the eye to instilled nitrogen mustard. Topical instillation of dipyridamole was ineffective. Dipyridamole, a clinically available drug, may be useful in the treatment of ocular inflammatory disease.
 ...
PMID:Effect of dipyridamole on prostaglandin-induced ocular hypertension in rabbits. 44 64

Imidazole, given intraperitoneally to rabbits, inhibited the prostaglandin E1-induced (PGE1) elevation of intraocular pressure. The maximum imidaz-le effect occurred at three to six hours after intraperitoneal infection. The prostaglandin E1-induced aqueous humor protein elevation was reduced markedly in the imidazole-pretreated rabbits. Intravenous administration of imidazole also was effective in reducing the intraocular pressure elevation produced by prostaglandin E1. Imidazole pretreatment by subconjunctival, subdermal, or topical routes had no such effect. Imidazole derivatives, 1-methylimidazole and 2-methylimidazole, given intraperitoneally, blocked the effect of PGE1 on intraocular pressure and aqueous humor protein. Imidazole pretreatment also inhibited the elevation of intraocular pressure produced by topical nitrogen mustard, 1 per cent.
 ...
PMID:Modification by imidazoles of ocular inflammatory and pressure responses. 112 83

After topically administered nitrogen mustard the irritative effect on the pupil, intraocular pressure, protein concentration of the aqueous humor and on the vessels of the iris and conjunctiva was quantified. The protein level in aqueous was determined by refractometry. The degree of hyperemia of conjunctiva and iris was determined by measuring the amount of Evans blue dye present in the tissue minutes after intravenous administration. A reproducible relationship was obtained using these methods to evaluate the degree of irritation produced by nitrogen mustard.
 ...
PMID:Objective evaluation of experimental ocular irritation. 126 62

With nitrogen cryotherapy, the authors achieve lasting normalization of intraocular pressure in more than 90% of their primary glaucoma cases. To accomplish this, the therapeutic parameters (working temperature, diameter of the applicator tip, duration of application, number of application points, applicator contact pressure) must be strictly defined and coordinated. The applicator contact pressure has hitherto been neglected in published data, although it dictates the heat transfer resistance between the applicator and the surface of the bulb and is therefore a major factor influencing the therapeutic effect. A device was therefore developed which indicates the applicator contact pressure continuously during therapy, both optically and acoustically. It renders cryotherapy just as effective as microsurgical methods, with no side-effects.
 ...
PMID:[A new device technic for cryotherapy of glaucoma]. 279 34

A perfusion system has been established for the organ culture of the lens. The system is designed so that a constant flow of fluid occurs past the lens and a separate channel of fluid simultaneously bypasses the lens. Lens metabolic activity can be determined by analyzing differences between these two samples of fluid. The system also maintains a level of pressure comparable to intraocular pressure. Apparatus for observation and photography of the lens is built into the system. The purpose of these studies was to determine if this perfusion system could maintain the rabbit lens close to the physiological state, to study the metabolic behavior of the lens under steady state conditions, and to determine the effect of increasing amino acid concentrations on the metabolic activity of the lens under steady state conditions. By increasing the amino acid concentrations in the medium we hoped to compensate for the lack of protein in the medium and to provide metabolic substrate to maintain the lens under perfusion conditions. The rabbit lens was cultured at a temperature of 33 degrees C for periods up to 100 h. A totally synthetic perfusion medium without proteins or antibiotics was devised. This medium imitates posterior chamber aqueous humour, except that it does not contain ascorbic acid because it was found that ascorbic acid readily auto-oxidizes and depletes the oxygen content of the medium. The amino acid concentration of the perfusion medium was adjusted so that its total nitrogen content was equivalent to the total nitrogen content of posterior chamber aqueous humour. To determine the metabolic behavior of the lens, 10 different metabolic substances were analyzed in the medium and 15 were analyzed in the lens. These substances are mainly metabolic substrates and end products. As a reference for the evaluation of the behavior of the lens in the perfusion system, the perfused lens was compared to the lens in the other eye of the rabbit. Standards for differences between the right and left lens and the first or second lens removed from the rabbit were developed in control studies. A series of experiments was devised to determine the effect of increased amino acid concentration in the medium on the metabolic behavior of the lens. Concentrations of amino acids from 0 to 7.26 times the posterior concentration of amino acids in chamber aqueous humour were studied. Seven studies were done with a flow rate of medium of about 2 g per h, with each experiment lasting from 80 to 100 h.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Effect of amino acid input rates on lens metabolism in a perfusion culture system. 301 5

At 3-hr intervals over a 24-hr span, 36 systemic, serologic and urinary variables were examined in 7 men in their mid 20's in the Spring of 1969, and again in the same 7 men in the Spring of 1979 under a similar chronobiologic protocol, using the same chemical and numerical analytical procedures. The variables examined for rhythms by cosinor were: vital signs--blood pressure (systolic, diastolic, pulse pressure and mean arterial pressure), heart rate, intraocular pressure (left and right), oral temperature; serum components--albumin, albumin/globulin ratio, total bilirubin, calcium, carbon dioxide, chlorides, bilirubin, cholesterol, globulin, glucose, potassium, sodium, sodium/potassium ratio, transaminase, triglycerides, total protein, urea nitrogen; and urine components--calcium, calcium/magnesium ratio, creatinine, magnesium, pH, potassium, sodium, sodium/potassium ratio, urea clearance, urea nitrogen, volume and zinc. Although all subjects appeared clinically healthy in 1969 and in 1979, certain inter-study differences were observed in a number of rhythm parameters of different variables. Statistically significant increases in mesor for the group as a whole were observed for serum Ca, cholesterol, Cl, CO2, K, Na, and while statistically significant mesor decreases for a group as a whole were noted in serum glucose and transaminase. Statistically significant increases in amplitude for the group as a whole were observed in serum chloride and urinary Na/K ratio, while statistically significant decreases were observed in amplitude for blood pressure, heart rate, serum albumin, A/G ratio, globulin, glucose, protein, sodium and transaminase.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Ten-year-replicated circadian profiles for 36 physiological, serological and urinary variables in healthy men. 321 57

The mechanism of the intraocular pressure (IOP) elevation commonly seen in patients following neodymium (Nd):YAG laser posterior capsulotomy is unclear. Substance P, a potent polypeptide that is released into the eye after trigeminal nerve stimulation, may be the cause. In rabbits, topical application of nitrogen mustard causes a rise in IOP which is blocked by capsaicin, a presumed substance P depletor. In the present study, six eyes of three cynomolgus monkeys underwent extracapsular lensectomies. After 2 to 3 months, capsaicin was administered by retrobulbar injection on one side of each animal, and vehicle on the contralateral side. One day later, Nd:YAG laser posterior capsulotomies were performed using 31 mJ (total energy) per eye. Diurnal IOP measurements were made before and after the retrobulbar injections and the capsulotomies. Ten weeks later, laser capsulotomies were repeated using 200 mJ/eye without pretreatment with any potential blockers. None of the six eyes, each undergoing two separate capsulotomies 10 weeks apart, showed a postoperative rise in IOP. These results demonstrate that the cynomolgus monkey is a poor model for studying IOP elevation that often occurs following Nd:YAG laser posterior capsulotomy.
 ...
PMID:Nd:YAG laser posterior capsulotomy does not produce elevation of intraocular pressure in cynomolgus monkeys. 341 75

Evidence for the biosynthesis and release of prostaglandins and related substances in pathophysiological states of ocular tissues is reviewed and their participation in ocular injury and acute inflammation discussed. Ocular tissues are capable of generating prostaglandins from the endogenous or exogenous precursor, arachidonic acid. Prostaglandins are released into the aqueous humour in response to paracentesis, mechanical or laser injury to the iris, and in experimental immunogenic and non-immunogenic ocular inflammation. Antidromic stimulation of the trigeminal nerve, formaldehyde or nitrogen mustard-induced irritation of the eye do not cause the release of prostaglandins, nor are the responses to these stimuli inhibited by prostaglandin synthetase inhibitors. Prostaglandins in small doses administered topically or intraocularly produce some of the responses of injury and inflammation, such as hyperaemia, miosis, breakdown of the blood-aqueous barrier and rise in intraocular pressure. Also, E-type prostaglandins administered topically together with histamine (but not the individual components) cause cellular infiltration and produce oedema in conjunctival tissues. Non-steroidal aspirin-like drugs at concentrations which inhibit prostaglandin biosynthesis markedly block injury responses but have only a moderate inhibitory effect on acute inflammatory reactions of the eye. The present evidence suggests that prostaglandins are involved in some of the injury and inflammatory responses. However, recent studies indicate that the intermediates of arachidonic acid metabolism, especially hydroxy fatty acids, may play a greater role in inflammatory responses.
 ...
PMID:Prostaglandins and inflammatory reactions in the eye. 680 89

Much of our knowledge of the ocular responses to irritants is derived from studies on the effects of mustards applied topically to the rabbit eye. The present study shows, however, that vertebrate eyes display profound species variations in the initial (first 6 hours) response to nitrogen mustard (NM). Rabbits and guinea pigs showed two episodes, ducks and cats one, and owl monkeys no episode of increased intraocular pressure. Development of anterior chamber flare and cellular invasion was seen in all species except ducks and owl monkeys. Pupillary constriction of differing time-course and magnitude was observed in all species except guinea pigs and ducks. At least one indomethacin-sensitive component of the NM-induced inflammatory response was demonstrated in each subprimate species, the nature of which depended upon the predominant ocular effect of prostaglandins in each. The present work suggests that while rabbits and guinea pigs may be of particular value for the study of some aspects of the ocular response to irritation and trauma, these species may be unsuitable for studying ocular inflammation and therapeutics as applicable to man.
 ...
PMID:Species variations in the pathophysiologic responses of vertebrate eyes to a chemical irritant, nitrogen mustard. 682 23

Diathermy and cryosurgery have different effects on living tissue. Cell membranes are ruptured by cryosurgery, but the proteins are less affected than by diathermy. A short review of experimental cyclocryosurgery and the clinical results are presented. Data from the literature as well as evaluation of patients confirm that, as yet, the results are not satisfactory. The sequelae of freezing are very different in slow-and fast-freezing procedures. Therefore, the results in rabbits treated with a cryosurgical unit used for retinal detachment surgery (Amoils, -80 degrees C) were compared with the results using a cryoprobe cooled with liquid nitrogen (-180 degrees C). A permanent reduction in intraocular pressure was not achieved using cyclocryotherapy applied with the equipment used for detachment surgery (-80 degrees C). Repeated cryosurgery of this type did not result in a permanent pressure reduction. Histopathology demonstrated that the ciliary epithelium had regenerated and prolongation of the cyclocryotherapy applications did not result in a permanent intraocular pressure reduction. Lens opacities occurred in all rabbits of this series. Application of cryotherapy with a nitrogen-cooled cryoprobe (2.5 mm2 contact area) caused severe damage, resulting in phthisis bulbi. Another nitrogen-cooled probe (contact area of about 1 mm2 diameter) resulted in a permanent reduction in intraocular pressure, but the anterior parts of the lens became opaque. Histopathology revealed total necrosis of the ciliary epithelium and the basal membrane. Three months after cyclocryotherapy of this type the ciliary processes were atrophic and covered with connective tissue and regeneration of epithelial cells was not found in areas of such cryotherapy scars. Further experiments have been commenced including a reduction of application time, in order to find the optimum application technique resulting in permanent intraocular pressure reduction and the fewest possible side effects.
 ...
PMID:[Experimental and clinical examinations of the effect of cryosurgery of intraocular pressure]. 691 Mar 55


1 2 3 Next >>