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Biomedical subjects

A Macri

Publications and source records attributed to A Macri.

At least 19 recordsLinked to original sources
PubMed2001

Effects of laser in situ keratomileusis on tear production, clearance, and the ocular surface.

PURPOSE: To evaluate components of the integrated ocular surface/lacrimal gland unit in a series of patients before and after undergoing bilateral laser in situ keratomileusis (LASIK). DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Forty-eight eyes of 14 men and 34 women (age range, 26-54; mean, 39.2 years) who underwent bilateral LASIK for myopia or myopic astigmatism. METHODS: LASIK was performed using a VISX Star Excimer Laser (Santa Clara, CA). Patients completed a questionnaire containing 11 questions that evaluated the character and severity of ocular irritation symptoms. Snellen visual acuity, tear fluorescein clearance, corneal fluorescein staining, aqueous tear production by the Schirmer 1 test, and corneal and conjunctival sensitivity were measured in each eye. Corneal surface regularity (SRI) was evaluated with the Tomey TMS-1 (Tomey, Cambridge, MA) topography instrument. Each randomly chosen eye was evaluated 1 to 2 days (T0) before LASIK and 7 days (T1), 1 (T2), 2 (T3), 6 (T4), 12 (T5), and 16 (T6) months postoperatively. A Wilcoxon test, two-tailed paired t test, Friedman test, or analysis of variance were used for statistical comparisons. MAIN OUTCOME MEASURES: Components of the integrated ocular surface/lacrimal gland unit. RESULTS: Both corneal and conjunctival sensitivity were noted to be significantly decreased from preoperative levels at 1week, 1 month, 12 months, and 16 months postoperatively (P < 0.0002 at each time point). Symptom severity scores were significantly increased at 1 week, 12 months, and 16 months postoperatively (P < 0.007 at all time points). The mean Schirmer 1 test scores were 24 +/- 14 mm preoperatively, and they decreased to 18 +/- 14 mm by 1 month postoperatively (P < 0.001). Tear fluorescein clearance showed a linear increase postoperatively and was significantly greater than baseline (P < 0.001) at each time point. There was a significant increase in punctate corneal fluorescein staining at 1 week postoperatively (P < 0.0001), but staining returned to baseline by 12 months. There was a statistically significant increase in SRI 1 week postoperatively (P < 0.007) with return to baseline levels by 6 months. CONCLUSIONS: Sensory denervation of the ocular surface after bilateral LASIK disrupts ocular surface tear dynamics and causes irritation symptoms. Patients undergoing LASIK should be informed of these risks.

Adult↗
PubMed2001

Pro- and anti-inflammatory forms of interleukin-1 in the tear fluid and conjunctiva of patients with dry-eye disease.

PURPOSE: To compare the expression of the pro- and anti-inflammatory forms of interleukin (IL)-1 in the tear fluid and conjunctival epithelium of normal eyes and those with dry-eye disease. METHODS: The concentrations of IL-1 alpha, IL-1 beta (precursor and mature forms), and IL-1 receptor antagonist (IL-1Ra) were measured by ELISA in tear fluid samples obtained from normal individuals and patients with dry eye who had rosacea-associated meibomian gland disease (MGD) or Sjögren's syndrome (SS) aqueous tear deficiency (ATD). These cytokines were also measured in normal tear fluid before and after nasal stimulation to induce reflex tearing. The relative expression of these cytokines was evaluated in conjunctival impression cytology specimens and conjunctival biopsy tissue obtained from normal subjects and SS ATD-affected patients using immunofluorescent staining. Matrix metalloproteinase (MMP)-9 concentration and activity in the tear fluid were evaluated with gelatin zymography and with an MMP-9 activity assay kit, respectively. RESULTS: Compared with normal subjects, the concentration of IL-1 alpha and mature IL-1 beta in the tear fluid was increased, and the concentration of precursor IL-1 beta was decreased in patients with MGD (P < 0.05, P = 0.02, and P < 0.01, respectively) and SS ATD (P < 0.001, P = 0.02, and P < 0.001, respectively). There was no significant change in the concentration of IL-1 alpha, precursor IL-1 beta, and IL-1Ra in reflex tear fluid, indicating that the lacrimal glands may secrete these cytokines. The activity of MMP-9, a physiological activator of IL-1 beta, was significantly elevated in the tear fluid of both dry-eye groups compared with normal subjects. A strong positive correlation was observed between the intensity of corneal fluorescein staining and the tear fluid IL-1 alpha concentration (r(2) = 0.17, P < 0.02) and the mature-to-precursor IL-1 beta ratio (r(2) = 0.46, P < 0.001). Positive immunofluorescent staining for IL-1 alpha, mature IL-1 beta, and IL-1Ra was observed in a significantly greater percentage of conjunctival cytology specimens from eyes with SS ATD than in those from normal eyes (P < 0.01 for IL-1 alpha, P < 0.009 for mature IL-1 beta, and P < 0.05 for IL-1Ra). CONCLUSIONS: Dry-eye disease is accompanied by an increase in the proinflammatory forms of IL-1 (IL-1 alpha and mature IL-1 beta) and a decrease in the biologically inactive precursor IL-1 beta in tear fluid. Increased protease activity on the ocular surface may be one mechanism by which precursor IL-1 beta is cleaved to the mature, biologically active form. The conjunctival epithelium appears to be one source of the increased concentration of IL-1 in the tear fluid of patients with dry-eye disease. These results suggest that IL-1 may play a key role in the pathogenesis of keratoconjunctivitis sicca.

Adult↗
PubMed2000

Correlation of the Schirmer 1 and fluorescein clearance tests with the severity of corneal epithelial and eyelid disease.

OBJECTIVE: To evaluate the correlations of the fluorescein clearance test (FCT) and the Schirmer 1 test with the severity of corneal epithelial and eyelid disease in normal patients and patients with tear film disorders due to meibomian gland disease (MGD) and/or aqueous tear deficiency (ATD). METHODS: Nineteen normal control subjects, 16 patients with MGD associated with rosacea, 21 patients with noninflammatory atrophic MGD, and 43 patients with ATD were enrolled. There was a similar age and sex distribution in each group. Each patient completed a symptom severity questionnaire that consisted of 11 questions and then underwent a panel of diagnostic tests in the following order: assessment of corneal and conjunctiva sensation with the Cochet-Bonnet esthesiometer, FCT, assessment of corneal fluorescein staining, Schirmer 1 test (5 minutes without anesthesia), and biomicroscopic examination of the eyelid margins and meibomian glands. The FCT was performed with a fluorophotometer by measuring the fluorescein concentration in minimally stimulated tear samples collected from the inferior tear meniscus. By studying the best area under the receiver operating characteristic curves, we developed a formula that combined the FCT and Schirmer test results, which we termed the FCT corrected by Schirmer test. RESULTS: The FCT showed stronger correlation with ocular irritation symptoms (r = 0. 35, P <.001), corneal fluorescein staining (r = 0.54, P<.001), and meibomian gland and eyelid pathologic signs than the Schirmer 1 test. A correction factor that was based on the best area under the receiver operating characteristic curves, added to the FCT score, improved its correlation with ocular irritation symptoms, eyelid margin and meibomian gland pathologic signs, and ocular surface sensitivity scores. CONCLUSIONS: Corneal epithelial disease is correlated with decreased aqueous tear production and delayed tear clearance, whereas eyelid and MGD are correlated with delayed tear clearance. The FCT corrected by Schirmer 1 test improves the correlations of the FCT with ocular irritation symptoms, corneal epithelial and eyelid pathologic signs, and corneal and conjunctival sensitivity for patients with MGD and ATD.

Aged↗
PubMed2000

A standardized visual scale for evaluation of tear fluorescein clearance.

OBJECTIVE: To evaluate the correlation and the agreement between a validated fluorometric technique (fluorescein clearance test) and a newly developed, clinically practical standardized visual scale to evaluate tear fluorescein clearance. Also, the ability of this new method to distinguish healthy persons from patients reporting ocular irritation associated with meibomian gland disease (MGD), aqueous tear deficiency (ATD), or both was tested. DESIGN: Case-controlled study. PARTICIPANTS: Healthy persons (n = 32), patients with MGD associated with rosacea (n = 30), patients with noninflammatory atrophic MGD (n = 24), and patients with ATD (n = 39) were evaluated. There was a similar age and gender distribution in each group. METHODS: Each subject completed a symptom questionnaire and had the following tests performed: fluorescein clearance test (FCT), standardized visual scale test (SVST), corneal fluorescein staining, Schirmer 1 test, corneal and conjunctiva sensitivity, and eyelid margin and meibomian gland examination. MAIN OUTCOME MEASURES: The FCT was performed with a CytoFluor II fluorophotometer by measuring the fluorescein concentration in minimally stimulated tear samples collected from the inferior tear meniscus 15 minutes after instillation of 5 microl of 2% sodium fluorescein. The SVST score, ranging from 0 to 6, was obtained by comparing the colors of the standardized visual scale with the color of the lateral inferior tear meniscus immediately before tear collection for the FCT. Severity of ocular irritation was assessed with a symptom questionnaire. Schirmer 1 test (without anesthesia), biomicroscopic meibomian gland evaluation, and corneal fluorescein staining were performed. Corneal and conjunctival sensitivity scores were assessed with the Cochet-Bonnet aesthesiometer. The correlation and the agreement between FCT, FCT corrected for Schirmer test (corrected FCT), SVST, and SVST corrected for Schirmer test (corrected SVST) in separating healthy persons from patients with ATD, MGD, or both were studied. Furthermore, the correlations of FCT, corrected FCT, SVST and corrected SVST, corneal fluorescein staining score, corneal and conjunctiva sensitivity, meibomian gland and eyelid evaluation, and questionnaire score were studied. RESULTS: The FCT, the corrected FCT, the SVST, and the corrected SVST all showed strong correlation with irritation symptoms, corneal fluorescein staining, Schirmer 1 test score, cornea and conjunctiva sensitivity, and meibomian gland and eyelid pathologic characteristics. The FCT, the corrected FCT, the SVST, and the corrected SVST had a sensitivity in diagnosing MGD, respectively, of 67%, 72%, 69%, and 76%, and of 95%, 97%, 97%, and 97% in diagnosing ATD. The specificity was, respectively, 97%, 96%, 97%, and 94%. CONCLUSIONS: The new standardized visual scale test was equivalent to fluorometric assessment of tear clearance in its correlation with irritation symptoms, ocular surface and eyelid disease, and ocular surface sensitivity. Its ability to separate healthy persons from patients with MGD and ATD was improved by applying a correction factor based on Schirmer test score. The new standardized visual scale test is an accurate and practical method for clinical assessment of fluorescein tear clearance.

Case-Control Studies↗
PubMed1999

Evaluation of the analgesic effect of 0.1% indomethacin solution on corneal abrasions.

PURPOSE: The authors wished to verify the analgesic action of 0.1% indomethacin in a water-based solution on patients affected by traumatic corneal abrasions. METHODS: 347 patients affected by traumatic corneal abrasions, having been randomly divided into 2 groups on the basis of the administration of indomethacin, were evaluated at 30 min, 12 h and 24 h after the initial treatment of the abrasion. The level of pain experienced was evaluated on a verbal pain scale and the healing time was evaluated relative to the dimension of the abrasion. RESULTS: The pain level was initially overwhelming for both groups: p = 0.737; at successive check-ups it was possible to verify a reduction of the symptomatology, with a more pronounced decrease in pain in the group treated with indomethacin (p < 0.0001), which also demonstrated a lower sensitivity to pain in the case of larger lesions (p < 0.0001). There was no difference in the healing time between groups, and the reduction of pain is not correlated with corneal anesthesia and healing time. CONCLUSIONS: Our study highlighted the efficacy of indomethacin as a pain reducer for acute corneal pathology and suggested that the medication may act on the corneal nociceptors in a qualitative way.

Adult↗
PubMed1998

A comparative study of computerised visual field testing and optic disc morphometric parameters in the follow-up of primary open angle glaucoma.

PURPOSE: To evaluate the correlation between computerised visual field testing and optic disc morphometric parameters (rim area, rim/disc area ratio, cup/disc area ratio and optic disc surface smoothness (ODSS)) in the follow-up of a group of patients affected by primary open angle glaucoma (POAG). METHODS: Reliable automated perimetry (Humphrey 640 VFA, central 30-2 threshold program) was performed at T0 (the enrollment time), T1 (after 6 +/- 1 months; range 5-7 months), T2 (12 +/- 1 months), T3 (18 +/- 1 months), and T4 (the end of the follow-up period: 24 +/- 2 months) in one eye randomly chosen from each of 30 POAG patients. Computerised optic disc analysis (IMAGEnet X Rev-3-51b, Topcon Europe, The Netherlands) was performed at T0 and T4. To evaluate the correlation between morphometric parameters and computerised visual field testing, the stability or worsening of visual field test was evaluated by means of 'Mean Deviation linear regression analysis' (STATPAC 2 software); that of morphometric parameters was studied using their coefficients of variation. A rank of '0' was assigned to stability and a rank of '1' to worsening. The Spearman rank correlation coefficient was used to evaluate statistically the correlations between visual field analysis and morphometric parameters. Furthermore kappa statistic was used to evaluate the agreement of morphometric parameter changes with visual field progression analysis. RESULTS: According to the MD slope regression analysis, in 18 patients the visual fields were stable while in 12 they were worsening during the follow-up period. In 86.65% of patients (n = 26) the morphometric parameter ODSS and visual field analysis were concordant (p < 0.0001). In 80% of patients (n = 24) the cup/disc area ratio and visual field analysis were concordant (p < 0.001). The other morphometric parameters (rim area, rim/dics area ratio) were less correlated with visual field analysis than ODSS (p < 0.05). The agreement of visual field analysis with all the morphometric parameters was good (kappa = 0.690, 95% confidence interval (CI) of kappa = 0.589-0.790). The agreement of visual field analysis with ODSS and cup/disc area (kappa = 0.688; 95% CI = 0.511-0.864) was better than the agreement of visual field analysis with rim area and rim/disc area ratio (kappa = 0.438; 95% CI = 0.260-0.655). CONCLUSION: Analysis of the progression of visual field damage and optic nerve head morphometric parameters should both be taken into account in glaucoma follow-up. Among the morphometric parameters evaluated by means of Topcon IMAGEnet, ODSS and (to a lesser extent) the cup/disc ratio should have the greatest weight.

Aged↗
PubMed1989

Familial porphyria cutanea tarda with normal erythrocytic urodecarboxylase: an exception to the rule?

The possibility that the differentiation between sporadic and familial porphyria cutanea tarda cannot always be made on the basis of the measurement of the erythrocytic uroporphyrinogen decarboxylase activity has been examined. Two cases of porphyria cutanea tarda, with a normal erythrocytic enzyme activity in a father and son, are described. The authors exclude that these are 2 cases of sporadic or toxic porphyria cutanea tarda within the same family. These 2 cases provide additional evidence for the existence of a form of familial porphyria cutanea tarda in which erythrocytic uroporphyrinogen decarboxylase activity is normal.

Adult↗
PubMed1984

Kinetics and bioavailability of N-nitrosodiethanolamine after intravenous and cutaneous administration to rats.

Male CD-COBS rats were given N-nitrosodiethanolamine (NDELA) by intravenous or cutaneous administration at a dose of 5 mg/kg. Blood and liver were analysed for NDELA at various times after administration. The excretion of unchanged NDELA and its acidic metabolite N-(2-hydroxyethyl)-N-carboxymethylnitrosamine (ECMN) was determined in urine for 24 hr after treatment. The semilogarithmic blood concentration-time plot after iv injection showed a triphasic profile indicating that a three-compartment model may adequately describe the kinetics of this compound. After cutaneous application NDELA was rapidly absorbed through the skin, and the absolute bioavailability was calculated to be 27% from blood data, and to be 32% (NDELA + ECMN) from urine data. Hepatic NDELA levels reflected blood levels after both treatments, indicating that this organ does not accumulate NDELA to a significant extent. Urinary excretion of unchanged NDELA after iv and cutaneous administration was 83 and 25% of the administered dose, respectively. ECMN excretion was 4.9 and 2.5% of the administered dose after iv and cutaneous administration, respectively.

Animals↗
PubMed1984

Experimental model for evaluating animal exposure to endogenous N-nitrosodi-n-butylamine by measuring its urinary metabolites N-butyl-N-(4-hydroxybutyl)-nitrosamine and N-butyl-N-(3-carboxypropyl)nitrosamine.

Endogenous formation of N-nitrosodi-n-butylamine (NDBA) was studied in rats after administration of sodium nitrite or sodium nitrate and N,N-dibutylamine (DBA) by monitoring the urinary excretion of NDBA and its metabolites, N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) and N-butyl-N-(3-carboxypropyl)nitrosamine (BCPN). Animals were given sodium nitrite (0.2%) or sodium nitrate (0.5%), dissolved in the drinking-water. This treatment was started 24 h before DBA administration and was continued throughout the experiment. Animals were fasted overnight before receiving DBA, which was administered by gavage as three doses of 50 mg/kg, 8 h apart; 24-h urine samples were collected on ammonium sulfamate. NDBA, BBN and BCPN were extracted and analysed by GC-TEA, according to a method previously described. Under the experimental conditions reported, NDBA and BBN (free or glucuronic acid-conjugated) were not detected in the urine of animals given nitrite or nitrate and DBA, but the presence of BCPN indicated that N-nitrosation had occurred in both groups of animals. These results suggest that, when studying nitrosamines that are extensively metabolized, quantitative analysis of urinary metabolites is a better indicator of nitrosamine exposure than measurement of nitrosamine itself.

Animals↗
PubMed1982

A study on the urinary and fecal excretion of furazolidone in rats by means of mutagenicity assays.

The urinary and fecal excretion of furazolidone in rats was studied by means of mutagenicity assays: when animals received a single dose by gavage (1 to 10 mg/100 g body wt) the mutagenic activity recovered in urines accounted for less than 0.1% of the administered dose and quickly disappeared. After prolonged (1 week) treatments, however, some mutagenicity was retained in urine concentrates until the fifth to seventh days. Similarly the fecal excretion of mutagenicity accounted for less than 0.1% of the administered dose and disappeared within the third day. The efficient deactivation of furazolidone observed in vivo was shown to be unaffected by the amount of gut bacteria in treated animals; in in vitro experiments it turned out to be actively performed by a rat intestine homogenate fraction, working more efficiently under hypoxic conditions.

Animals↗
PubMed1977

Adaptation of the domestic chicken, Gallus domesticus, to continuous feeding of albumin amylase inhibitors from wheat flour as gastro-resistant microgranules.

Albumin amylase inhibitors were extracted from wheat flour, precipitated by salting out the extract with ammonium sulphate, and enclosed in cellulose-coated microgranules resistant to the peptic action in the chicken gizzard. Continuous intake of gastro-resistant wheat albumins significantly (P less than 0.01) depressed chicken growth rate, whereas native wheat albumins did not show such an effect. After 4 weeks of treatment, treated chickens showed a growth rate identical to that of control chickens thus showing that an adaptation to the presence of wheat albumins in the diet had occurred. Treated chickens also showed pancreas hypertrophy and a number of histological changes in the pancreas indicating degenerative processes in progress. Moreover, in treated chickens the production of pancreatic amylase was markedly increased (P less than 0.02), whereas pancreatic protease activity was less affected. The data obtained suggest that the synthesis of pancreatic amylase in chicken is under some homeostatic control of alpha-amylase in the intestine.

Adaptation, Physiological↗