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Biomedical subjects

M Ciancaglini

Publications and source records attributed to M Ciancaglini.

At least 37 records · Page 2Linked to original sources

Ultrastructural changes in rat cornea after prolonged hypobaric hypoxia.

A study was performed to evaluate the effect of prolonged environmental hypobaric hypoxia on the ultrastructure of rat cornea. 60-day-old female Wistar rats were exposed to a simulated altitude of 5,500 m (350 mmHg) and pO2 of 76 mmHg for 30 days. Control rats were exposed to atmospheric sea level pressure (760 mmHg) and pO2 of 150 mmHg, for the same period. Ultrastructural analysis of the corneal epithelium did not reveal any relevant difference between control and treated rats. In contrast, the corneal stroma of rats subjected to hypoxia showed vascularization with advanced vessel differentiation and signs of active proliferation. The endothelium of hypoxic cornea showed swollen mitochondria and large empty cytoplasmic areas. The endothelial intercellular junctions could hardly be identified in the hypoxic condition. Nevertheless, the most evident change in hypoxic cornea was in Descemet's membrane, which was considerably thickened, to approximately twice that of the control specimen. These results suggest that environmental hypobaric hypoxia induces marked alterations in the corneal stroma and endothelium morphology, probably related to reduced oxygen tension in the aqueous humor, consequent to hypoxemia.

Animals↗

Ocular hypotensive effect of topical ketanserin in timolol users.

BACKGROUND: Ketanserin is a specific antagonist of 5-HT2 and 5-HT1c receptors. These receptors are linked to the stimulation of phosphoinositide metabolism and are involved in IOP controls. Orally and topically administered ketanserin reduces IOP in normotensive and glaucomatous eyes. METHODS: Ketanserin 0.5% eye drops were administered to 20 patients with primary open-angle glaucoma in a randomised, crossover, double-masked fashion to evaluate the effect of ketanserin in glaucomatous patients already receiving timolol who did not have controlled IOP (> 21 mmHg). Mean and range of IOP curve (8.00 a.m.-8.00 p.m.), pupil diameter, Schirmer I, basal secretion test and BUT values were recorded at baseline and after 2 weeks of topical administration of ketanserin or placebo twice daily. The alternative treatment was given 2 weeks later and the same protocol was repeated. RESULTS: When patients received placebo no significant variations were found in the analysed parameters. Ketanserin significantly reduced mean IOP (19.5%) and was effective for up to 12 h without inducing variations of tear secretion or pupil diameter. No systemic side effects were observed, and no significant variations in ocular symptoms and signs were reported. CONCLUSION: These results indicate that topical administration of ketanserin may be useful to reduce IOP in patients not controlled with beta-blockers.

Administration, Topical↗

Heparin eyedrops to prevent posterior capsule opacification.

PURPOSE: To evaluate whether heparin eyedrops prevent or reduce posterior capsule opacification (PCO) after extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation. SETTING: Institute of Ophthalmology, University G. d'Annunzio, Chieti, Italy. METHODS: This 4 year, prospective, case-controlled study evaluated 200 patients who had ECCE and implantation of the same type of posterior chamber IOL. Patients were randomly assigned to receive topical heparin eyedrops postoperatively (heparin group, n = 100) or not to receive the eyedrops (control group, n = 100). Postoperative cell response, cellular precipitates on the IOL, and presence of PCO were evaluated. RESULTS: There were no significant differences between groups in postoperative inflammation. The incidence of cellular precipitates was significantly lower in the heparin group than in the control group (P < .001). A neodymium:YAG (Nd:YAG) posterior capsulotomy was done in 7 patients in the heparin group and 14 in the control group (P = .15). During the first 24 months after surgery, the heparin group had a significantly lower incidence of Nd:YAG capsulotomy (P < .05) and fibrotic PCO (P = .02). CONCLUSION: Topical heparin eyedrops were effective in reducing fibrotic PCO in the long term, indicating their usefulness in the postoperative management of ECCE.

Administration, Topical↗

Polycyclic aromatic hydrocarbons in bovine lens.

A study was performed to detect the presence of polycyclic aromatic hydrocarbons (PAHs) in bovine eyes. Twenty fresh bovine eyes were used to detect the presence of PAHs in lens, vitreous and aqueous by HPLC and spectrofluorometer. In lenticular tissue the mean amount of PAHs was 0.0271 microgram/g and the mean level of PAH in each lens was 0.059 microgram. Five types of PAHs (pyrene, fluoranthene, triphenylene, 1.2-benzanthracene and chrysene) were found in the lenses but none in vitreous and aqueous. These data indicate that PAHs are present only in the lens of the bovine eye. The source of these substances in mammalian clear lens is unclear.

Animals↗

Hypoxanthine and xanthine levels in human aqueous humor from cataractous eyes.

Purine nucleotide degradation products have been determined by HPLC in aqueous humor obtained during cataract surgery and from plasma of 22 patients (12 women). Uric acid, cytosine, guanosine monophosphate, uracyl, guanine, adenosine, adenosine monophosphate, thymine, adenine, inosine, cyclic guanosine monophosphate, hypoxanthine and xanthine were evaluated. Uric acid and the last two were the only compounds detectable in measurable amounts in aqueous humor and in plasma of all patients. Aqueous humor xanthine levels were not significantly different from plasma; aqueous humor hypoxanthine concentrations were lower than those of xanthine and than plasma oxypurine levels. In 8 patients, treated with allopurinol, oxypurinol concentrations in aqueous humor and in plasma were comparable suggesting that oxypurines are transported through the blood-aqueous humor barrier.

Aqueous Humor↗

The ability of bacteria to use Na-hyaluronate as a nutrient.

The objective of this study was to test bacteria ability to use Na-hyaluronate as a nutrient in vitro. Thirteen bacteria strains were tested in three different media: specific culture medium, agar-Healon medium and agar-Healon GV medium. The bacterial growth criteria were determined by counting the number of new colonies appearing at each observation time (0, 24, 48 and 72 h). The results were expressed as the percentage of growth in agar-Na-hyaluronate compared to each corresponding specific culture medium. After 24 h in the medium containing agar-Healon, S. aureus, S. epidermidis, S. pyogenes and S. viridans grew using hyaluronic acid as a nutrient. The percentage of growth of these species remained constant over the follow-up period. The other bacteria strains tested were unable to use Healon as a nutrient. After 24 h of incubation in the medium containing agar-Healon GV, S. aureus, S. epidermidis, S. pyogenes, and S. viridans exhibited about 20% growth. Subsequently, this percentage slowly increased to about 50%. The other bacteria stains tested were unable to employ Healon GV as a nutrient. With the exception of Staphylococci and Streptococci, the other species do not synthesize the necessary enzymes to break glucosidic bonds, therefore neither concentration of hyaluronic acid can be utilized as a source of carbohydrate for their survival in culture media.

Bacteria↗

Long term results of intraoperative mitomycin C in the treatment of recurrent pterygium.

AIM: The study was designed to evaluate the long term results of intraoperative mitomycin C in patients with one recurrence of pterygium. METHODS: In 45 white patients with one recurrence of pterygium the 'bare sclera technique' was performed and a sterile sponge soaked in a 0.2 mg/ml (0.02%) mitomycin C solution was placed intraoperatively on the sclera for 3 minutes. The control group underwent surgical excision only. Recurrences were analysed by the chi 2 test and the method of Kaplan-Meier (life table analysis); the difference between survival curves was tested by the log rank test. The chi 2 test with Yates's correction or Fisher's exact test were used to analyse the difference in complications and side effects between the two groups. RESULTS: After a mean postoperative follow up of 34.55 (SD 13.70) months, 6 recurrences (12.5%) were observed in the mitomycin C treated patients and 16 (35.6%) in the control patients (p = 0.027). The 24 and 48 month life table success rates were 89% and 83% in the mitomycin C treated group and 66% and 63% in the control group, respectively (p = 0.022). No severe side effects appeared during follow up. Superficial punctate keratitis appeared in the early postoperative period in only seven mitomycin C treated eyes (15.5%) (p = 0.018). CONCLUSION: This study confirms the efficacy of intraoperative mitomycin C in improving the success rate after recurrent pterygium surgical excision.

Adult↗

Effect of dapiprazole, an alpha-adrenergic blocking agent, on aqueous humor dynamics in pigmentary glaucoma.

PURPOSE: In this investigation the authors studied the effect of dapiprazole, an alpha-adrenergic blocking agent, on aqueous humor dynamics in patients affected with pigmentary glaucoma. METHODS: Dapiprazole 0.5% eye drops were administered 3 times daily as adjunctive therapy to 16 pigmentary glaucoma patients in addition to timolol 0.5% eye drops twice daily. Computerized tonography was performed before and 3, 12 and 36 months after dapiprazole treatment. Sixteen sex- and age-matched pigmentary glaucoma patients treated with timolol 0.5% eye drops alone were used as a control group. RESULTS: After 36 months of follow-up, the dapiprazole-treated group showed a significant increase in total outflow facility (C, from 0.17 +/- 0.04 to 0.22 +/- 0.07 ml min-1 mm Hg-1; p = 0.010, paired t test) and Po/C ratio (Q) significantly decreased from 113.39 +/- 31.02 to 89.22 +/- 51.66 (p = 0.036, paired t test). CONCLUSIONS: Our results show that the introduction of dapiprazole in the therapy of pigmentary glaucoma may be useful in the long-term management of these patients. Its mechanism of action is likely to be due to iridoplegia; in fact, a decrease in the shedding of pigment occurs, with time, the outflow facility increases and the pigment clearance from the trabecular meshwork is enhanced.

Administration, Topical↗

Long-term results of Krupin-Denver valve implants in filtering surgery for neovascular glaucoma.

The long-term results obtained with the Krupin eye short valve shut in 28 eyes with neovascular glaucoma were retrospectively analyzed by means of Kaplan-Meier survival curve. The preoperative intraocular pressures (IOPs) ranged from 28 to 62 mm Hg (mean, 36.8 +/- 5.8 mm Hg). Success was considered an IOP of less than 22 mm Hg and greater than 5 mm Hg without medication (complete success) or with medication (qualified success) without additional glaucoma filtering surgery or devastating complications. Postoperative success was obtained in 10 out of 28 eyes after a mean follow-up period of 58.4 +/- 23.02 months (range, 10-108 months). The 3- and 6-year life table success rates were 66 and 34%, respectively. Early complications were: shallow or flat anterior chamber (15 patients, 53.6%), hypotony (16 patients, 57.1%), hypertony (7 patients, 25%), serous choroidal effusion (7 patients, 25%), fibrinous uveitis (5 patients, 17.9%), blockage of the intracameral portion of the tube by fibrin (5 patients, 17.9%), choroidal hemorrhage (2 patients, 7.1%). Late complications were: external conjunctival bleb failure (12 patients, 42.9%), blockage of the intracameral portion of the tube by fibrovascular tissue (5 patients, 17.9%), cataract (2 patients, 7.1%), bullous keratopathy (2 patients, 7.1%), external erosion of the Silastic valve (2 patients, 7.1%), phthisis bulbi (2 patients, 7.1%). Mortality during long-term follow-up was high in our series. The complications of an underlying diabetes mellitus were the most common cause of death (15 out of 22 patients). The high mortality of patients subjected to valve implantation makes it difficult to interpret the results of long-term studies. However, the valve implant is still today an alternative surgical procedure for controlling IOP in eyes with neovascular glaucoma that have visual potential.

Aged↗

The usefulness of dapiprazole, an alpha-adrenergic blocking agent, in pigmentary glaucoma.

The aim of this study was to increase understanding of the usefulness of an alpha-adrenergic blocking agent, dapiprazole 0.5% eyedrops, as an adjunct in antiglaucomatous therapy for 20 patients with pigmentary glaucoma receiving timolol 0.5% and pilocarpine 1%. After 12 months of dapiprazole treatment, the difference from the pretreatment mean intraocular pressure (IOP) value was statistically significant (P = .005). After 12 and 36 months of treatment, an hour-to-hour comparison of diurnal IOP curve values showed a statistically significant difference in all cases (P < .001). Although further investigations may be necessary to reach a definite conclusion, dapiprazole appeared to have a beneficial, stable in time effect in these patients.

Administration, Topical↗

Tear deficiency in Fuchs' intermediate uveitis.

OBJECTIVE: To assess quantitatively and qualitatively tear secretion in Fuchs' intermediate (heterochromic) uveitis to detect any possible anomaly linked to Fuchs' uveitis. DESIGN: Prospective study. SETTING: University eye clinic, Chieti, Italy. PATIENTS: Thirty consecutive white patients aged 32 to 65 years with unilateral Fuchs' heterochromic uveitis. OUTCOME MEASURES: Results of Schirmer's test I, tear film breakup time, conjunctival mucus ferning. RESULTS: Schirmer's test I showed a tear deficiency in 15 patients; the tear film breakup time and ferning were abnormal in these patients. There was a significant difference in the test results between the affected eyes and the fellow, unaffected eyes (p < 0.001). There was no relation between tear deficiency and age. CONCLUSIONS: The presence of tear anomalies only in the affected eye of patients with Fuchs' heterochromic uveitis suggests a link between Fuchs' uveitis and tear deficiency.

Adult↗

Colour vision and persistent microalbuminuria in children with type-1 (insulin-dependent) diabetes mellitus: a longitudinal study.

In an attempt to elucidate colour vision in children with type 1 (insulin-dependent) diabetes mellitus without fluorescein angiographic signs of retinopathy, we studied a group of 50 patients of mean age + or - SD 10.27 + or - 2.89 (range 8.1-13.0 years). Results were compared with a sex-and age-matched control group. The Farnsworth-Munsell 100-hue test showed a significantly higher value in total error score (TES) in diabetics than in controls (64.07 + or - 18.32 and 54.27 + or - 12.87, respectively: P = 0.0004). Diabetic patients were divided in two groups as regards presence of persistent microalbuminuria and followed for 7 years. The HbAlc values of the two groups were: normoalbuminuric 7.10 +/- 2.92%, microalbuminuric 9.79 + or - 1.41 (P = 0.004). Microalbuminuric patients showed a significantly higher TES than normoalbuminuric subjects both at the beginning (94.79 + or - 13.98 vs. 58.10 + or - 11.98) and end of the study (103.07 + or - 14.61 vs. 61.04 + or - 13.36: P < 0.0001), and after follow-up they had a worse TES than at the beginning of the study (P = 0.01); no change in TES was found in normoalbuminuric patients during the study. The results suggest that a deficit in colour vision occurs in diabetic children before the onset of fluorescein angiographic signs of retinopathy. Our follow-up shows that microalbuminuric patients present a significant worsening of colour vision. When a patient shows persistent microalbuminuria, colour vision must be carefully evaluated, also in subjects without fluorescein angiographic signs of retinopathy.

Adolescent↗