Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors have carried out a statistical study on two large groups of patients operated on for cataract and in whom the enzyme alph-chymotrypsin has been used, and the occurrence of ocular hypertension has been examined. One group, which contained 1,003 operations most of which were under the microscope using a firm closure technique, was compared with another group of 324 cases operated under the same conditions but without using the enzyme. In all cases the intraocular pressure was measured 24-48 hours after the operation. The rise in pressure, the rapidity of its development were studied together with its duration and the concentration of the enzyme. In addition these findings were compared with another group of 2,334 eyes operated on several years previously with standard techniques using a less hermetic wound suture, without a microscope, with alpha-chymotrypsin, but whose tensions were controlled from the third week. The results show conclusively that there is a greater frequency of the occurrence of raised intra-ocular pressure when the enzyme is used (40,3%) than when it is not used (25,3%). This ocular hypertension persists in all cases to the end of three weeks. The time of the appearance of the hypertension, the numbers affected and the duration of the intraocular pressure were not significantly meaningful in the statistical analysis.
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PMID:[Enzymatic ocular hypertension: a statistical study (author's transl)]. 14 59

In 499 patients operated on for cataract, the clinical postoperative signs of extraocular inflammation (conjunctival hyperaemia, chemosis, discharge and oedema of the lids), the number of infiltrates around the corneoscleral sutures, and the severity of intraocular inflammation in the anterior chamber (aqueous-flare) were assessed on the fourth postoperative day and correlated with the bacterial conjunctival flora examined both qualitatively and quantitatively on the same day. Patients with potential pathogens (Staphylococcus aureus, gram-negative bacilli and streptococci) on the conjunctiva following operation did not show any increased inflammatory reactions when compared with those without such pathogen. The quantity of bacteria, i.e. number of colonies, did not appear to play a role. The reasons are discussed. The clinical postoperative inflammatory signs were further correlated with the following factors: surgical complications, quality of suturing technique, use of alpha chymotrypsin, systemic disease, sex and age. A positive correlation was found between the severity of extraocular inflammation and retained lens material and hyphaema. Furthermore, extraocular reactions were more severe in males than in females. The incidence of infiltrates around corneoscleral sutures was found to vary with age, i.e. occurred more frequently in patients less than 60 years. No relationship was found between the severity of aqueous-flare and the above mentioned factors.
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PMID:Bacterial flora in relation to cataract extraction. IV. Postoperative inflammation. The role of conjunctival bacteria and certain surgical factors. 98 45

We have undertaken a retrospective review of samples of case records from patients undergoing cataract surgery at St Thomas's Hospital over the years of the introduction of new extracapsular techniques and the widespread use of intraocular lens implants. We found no significant change in the proportion of patients achieving a corrected visual acuity of better than or equal to 6/12 three months after surgery. However, the pattern of complications was found to have changed in three respects. Firstly, there was a fall in the frequency of raised intraocular pressure requiring treatment associated with the abandonment of intracapsular surgery and the use of chymotrypsin. Secondly, a considerable number of patients who had had extracapsular extractions suffered from visually disabling posterior capsular thickening (13%). Thirdly, there was a downward trend in the rates of vitreous loss and of reduced vision at three months due to vitreous haemorrhage, vitritis, and retinal detachment in the patients undergoing extracapsular cataract surgery.
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PMID:Changing patterns of early complications in cataract surgery with new techniques: a surgical audit. 341 39

Trypsin inhibition (reduction in benzoyl arginine p-nitroanilide hydrolysis), elastase inhibition (reduction in succinyl trialanyl p-nitroanilide hydrolysis), and chymotrypsin inhibition (reduction in acetyl tyrosine ethyl ester hydrolysis) by neutral extracts of mammalian lenses were estimated. The activities were found to be markedly elevated in human cortical cataract lenses compared to normal adult lenses (antielastase 7.21 +/- 3.90 units (mean +/- SD) in cataract compared to 1.46 +/- 0.57 in normals; antitryptic, 0.54 +/- 0.38 and 0.12 +/- 0.04; antichymotryptic, 1.03 +/- 0.61 and 0.297 +/- 0.055). Antielastase activity was distinctly higher in adult normal human lenses compared to infant lenses (0.159 +/- 0.068). Elastase- and trypsin-like activities were detected at low levels in all mammalian lenses. Chymotrypsin-like activity could not be observed in the lenses. The cataractous lenses had lower trypsin- and elastase-like activities compared to normal human lenses (elastase 1.20 +/- 0.643 in normal compared to 0.062 +/- 0.035 in cataract; trypsin, 0.367 +/- 0.154 and 0.069 +/- 0.038). The role of protease: inhibitor complexes in the expression of the individual activities and their role in cataractogenesis are discussed.
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PMID:Proteases and protease inhibitory activities in normal mammalian lenses and human cataractous lenses. 351 55

One hundred eyes undergoing intracapsular cataract extraction and 100 undergoing extracapsular extraction were examined prospectively within one week postoperatively and again at 6-10 weeks postoperatively. Indirect ophthalmoscopy showed vitreous haemorrhage in 36% of the intracapsular group and 13% of the extracapsular group. Vitreous haemorrhage was significantly related to the occurrence of operative hyphaema (p less than 0.01) but not to iridectomy (p greater than 0.05). In the intracapsular group the use of chymotrypsin significantly reduced the incidence of vitreous haemorrhage (p less than 0.01). Three different types of vitreous haemorrhage were identified--streaks, diffuse haze, and beads in the vitreous base. Wound haemorrhage and operative hyphaema account for most cases, but it is suggested that zonular traction may be responsible for the bead haemorrhages and also for the retinal haemorrhages reported by other authors. Although no difference in visual result or incidence of cystoid macular oedema was observed in this study, a relationship to the vitreoretinal pathology of aphakia is suggested.
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PMID:Vitreous haemorrhage after cataract extraction. 408 84

The transfer coefficient of fluorescein across the corneal endothelium, kc.ac, was determined by a method of oral dye administration in 54 normal eyes. The kc.ac averaged 0.46 +/- 0.13 (SD) hour-1, and the fluorescein distribution ratio between the anterior chamber and the cornea, rac, was 0.57 +/- 0.20. There were no significant differences in these values between young subjects and those older than 50 years. A total of 56 eyes which underwent intracapsular cataract extraction were divided into three groups, 1) those operated on with routine medications, 2) with topical indomethacin and 3) with alpha-chymotrypsin of 7,500 times dilution. The value of rac was fixed at 0.57 and kc.ac was calculated taking the fraction, X, of unbound fluorescein in the aqueous into account. In addition, the apparent transfer coefficients of the dye between the blood and anterior chamber, k'in and k'out, were also calculated from the apparent fluorescein concentrations in the whole plasma and aqueous. The kc.ac was significantly greater in patients than in normal eyes, showing damage of the corneal endothelium by the surgery. The value of X was less than unity, indicating an increase in aqueous protein in the patients, but it was closer to unity in the indomethacin group than in other groups. The value of k'in was significantly less in the indomethacin group than in other groups. Between the groups with routine medication and with chymotrypsin, no significant difference was found in X or in k'in. It was concluded that topical indomethacin suppressed disruption of the blood-aqueous barrier and also that chymotrypsin at the present dilution did not cause serious disruption of the barrier.
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PMID:A fluorophotometric study of the barrier functions in the anterior segment of the eye after intracapsular cataract extraction. 662 Jul 23

Methylglyoxal (MGO), a potent glycating agent, forms advanced glycation end products (AGEs) with proteins. Several diabetic complications including cataract are thought to be the result of accumulation of these protein-AGEs. alpha-Crystallin, molecular chaperone of the eye lens, plays an important role in maintaining the transparency of the lens by preventing the aggregation/inactivation of several proteins/enzymes in addition to its structural role. Binding of adenosine-5-triphosphate (ATP) to alpha-crystallin has been shown to enhance its chaperone-like function and protection against proteolytic degradation. In the earlier study, we have shown that modification of alpha-crystallin by MGO caused altered chaperone-like activity along with structural changes, cross-linking, coloration and subsequent insolubilization leading to scattering of light [Biochem. J. 379 (2004) 273]. In the present study, we have investigated ATP binding, stability and degradation of MGO-modified alpha-crystallin. Proteolytic digestion with trypsin and chymotrypsin showed that MGO-modified alpha-crystallin is more susceptible to degradation compared to native alpha-crystallin. Furthermore, ATP was able to protect native alpha-crystallin against proteolytic cleavage but not MGO-modified alpha-crystallin. Interestingly, binding studies indicate decreased ATP binding to MGO-modified alpha-crystallin and support the decreased protection by ATP against proteolysis. In addition, differential scanning calorimetric and denaturant-induced unfolding studies indicate that modification of alpha-crystallin by MGO leads to decreased stability. These results indicate that MGO-modification of alpha-crystallin causes partial unfolding and decreased stability leading to enhanced proteolysis. Cross-linking of these degraded products could result in aggregation and subsequent insolubilization as observed in senile and diabetic cataract lenses.
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PMID:Enhanced degradation and decreased stability of eye lens alpha-crystallin upon methylglyoxal modification. 1538 Oct 41