Tear proteome and protein network analyses reveal a novel pentamarker panel for tear film characterization in dry eye and meibomian gland dysfunction

Dry eye and meibomian gland dysfunction are common ocular surface disorders. Discrimination of both conditions often may be difficult given the overlapping of signs and symptoms, and the lack of correlation with clinical parameters. A total of 144 individuals were included in this study. To search for proteome differences, tear proteins were collected by Merocel sponge and analyzed using 2D-PAGE. Comparative tear protein profile analysis indicated changes in the expression levels of fifteen proteins. Subsequent to MALDI-TOF/TOF protein identification, network analysis revealed expression/interaction connections with other proteins, thereby identifying additional putative markers. A screening validation assay demonstrated the discriminative power of six candidate biomarkers. A further validation study using multiplexed-like ELISA assays in tear samples collected with both sponge and capillary confirmed the high discriminatory power of five biomarkers: S100A6, annexin A1 (ANXA1), annexin A11 (ANXA11), cystatin-S (CST4), and phospholipase A2-activating protein (PLAA) with an area under ROC curve (AUC)≥ 97.9% (sensitivity ≥ 94.3%; specificity ≥ 97.6%) when comparing dry eye and control individuals. This panel also discriminated between dry eye, meibomian gland dysfunction and control individuals, with a global correct assignment (CA) of 73.2% between all groups. Correct assignment was not found to be significantly dependent on the tear collection method.

Changes in tear protein profile in keratoconus disease

PURPOSE

To analyze tear protein profile variations in patients with keratoconus (KC) and to compare them with those of control subjects.

SUBJECTS AND METHODS

Tears from 12 normal subjects and 12 patients with KC were analyzed by two-dimensional gel electrophoresis (2-DE) and liquid chromatography-mass spectrometry (LC-MS). Analysis of the 2-DE gels was performed using Progenesis SameSpots software (Nonlinear Dynamics). Proteins exhibiting high variation in expression levels (P-value <0.05) were identified using matrix-assisted laser desorption/ionization-TOF spectrometry. For LC-MS analysis, a label-free quantification approach was used. Tears were digested with trypsin, subjected to data-independent acquisition (MS(E)) analysis, and identified proteins were relatively quantified using ProteinLynx Global Server software (Waters).

RESULTS

The 2-DE and LC-MS analyses revealed a significant decrease in the levels of members of the cystatin family and an increase in lipocalin-1 in KC patients. A 1.43-fold decrease was observed for cystatin-S by 2-DE, and 1.69- and 1.56-fold for cystatin-SN and cystatin-SA by LC-MS, respectively. The increase in lipocalin-1 was observed by both methods with fold changes of 1.26 in the 2-DE approach and 1.31 according to LC-MS. Significant protein upregulation was also observed for Ig-κ chain C and Ig J chain proteins by 2-DE. Levels of lipophilin-C, lipophilin-A, and phospholipase A2 were decreased in tears from KC patients according to LC-MS. Serum albumin was found to be increased in KC patients according to LC-MS.

CONCLUSION

The results show differences in the tear protein profile of KC and control subjects. These changes are indicative of alterations in tear film stability and in interactions with the corneal surface in KC patients.

[Protected penetrating keratoplasty: surgical technique and endothelial response]

PURPOSE

To describe the technique and to evaluate the safety of protected penetrating keratoplasty (PPK).

METHODS

A technique for penetrating keratoplasty is described. The postoperative endothelial cell counts of 17 eyes in which this operative technique was used were compared with those in 24 eyes in whom the standard operative technique for penetrating keratoplasty (PK) was used. The post-operative time periods were grouped as follows: 3-6 months, 7-12 months and >12 months. For statistical analysis, the Mann-Whitney U non-parametric test was employed.

RESULTS

There was no case where tissue extrusion occurred during the procedure. The endothelial cell count was similar in both groups for the 3-6 month period (PK = 2,086, DS 566; PPK = 1,858, DS 671; p = 0.2702) and >12 months period (PK = 1,574, DS 745; PPK = 1,419, DS 810; p = 0.2882). There was a significant difference in the 7-12 month period (PK = 2,255, DS 831; PPK = 1,569, DS 623; p = 0.0397).

CONCLUSIONS

The described technique of PPK may reduce the risk of per-operative complications. Damage to the endothelium is not increased compared with that seen following the standard PK procedure.

[Subclinical keratoconus diagnosis by elevation topography]

PURPOSE

To evaluate the most effective parameters of Orbscan Corneal Topography System for subclinical keratoconus screening.

METHODS

The study includes corneas from patients with clinical diagnosis of keratoconus (group 1, n=35), patients with subclinical keratoconus (group 2, n=14) and a control group of myopic subjects paired in gender, age and refractive spherical equivalent (group 3, n=35). Placement of the apex, anterior and posterior corneal elevation, minimal corneal thickness, anterior chamber depth and corneal diameter were evaluated.

RESULTS

The most frequent location of the apex was at the inferotemporal sector (53%). Mean anterior elevation was 56.73 S.D. 25.95 mm in group 1 and 20.35 S.D. 8.04 mm in group 2; results that are statistically significant different from the control group (p<0.001). Mean posterior elevation was 126.23 S.D. 57.7 mm in group 1 and 54.28 S.D. 19.55 mm in group 2, both showing a statistically significant difference from the control group (p<0.001). Minimal corneal thickness and anterior chamber depth also showed statistically significant differences between the three groups. No differences were found in corneal diameter values.

CONCLUSIONS

Statistically significant differences were found in anterior and posterior elevation, minimal corneal thickness and anterior chamber depth parameters, as measured by the Orbscan system, between normal myopic subjects and those with clinical and sub-clinical keratoconus. These parameters should be considered in the detection of patients with increased risk for developing secondary keratectasia following corneal refractive surgery.

[Iris-claw phakic intraocular lens for high myopia correction. Visual and refractive results]

PURPOSE

To determine predictability, efficacy, complications and patient's satisfaction to phakic intraocular lens (Artisan) in highly myopic patients.

METHOD

Retrospective study of 65 eyes (36 patients), with preoperative spherical equivalent (SE) between -9,75 and -25,0 diopters (D) operated on by a single surgeon (JAD) between January 1999 and August 2001. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, postoperative complications, and patient's subjective response were evaluated.

RESULTS

UCVA evaluated 3 months postoperatively was 0.47 and BSCVA was 0.62. An average gain of 2.3 lines was observed with respect to the preoperative BSCVA. Refraction between +/-0.50 D from emmetropia ocurred in 49.23% of the eyes, and between +/- 1.0 D in 78.46% of the eyes. The difference between intended SE (preoperative SE minus IOL diopter) and achieved postoperative SE, showed a 0.55 D mean undercorrection. An intraocular pressure (IOP) over 30 mmHg was seen in 10% of the eyes in the immediate postoperative period. Night halos/glare perception was <<mild>> in 20% of the eyes, and in 90.77% of the cases the patient showed satisfaction with the results of the procedure.

CONCLUSION

Artisan iris-claw phakic lens implantation in highly myopic eyes is a safe procedure that increases BSCVA. It was observed a tendency towards undercorrection in the postoperative refractive outcome.

[Retinal ganglion cell neuroprotection in culture]

PURPOSE

To study the pig retinal ganglion cell (RGC) survival in culture, analysing the possible neuroprotective effect of retinal Müller glia (RMG) and brain-derived neurotrophic factor (BDNF).

METHODS

Adult pig retina were dissociated and cultured under different conditions: 1) on laminin/poly-D-lysine-coated coverslips in chemically defined medium (CDM); 2) on laminin/poly-D-lysine-coated coverslips in CMD supplemented with BDNF; 3) on confluent monolayer cultures of RMG in CDM; 4) on laminin/poly-D-lysine substrate in conditioned medium obtained from RMG. RGCs were identified by immunocytochemistry using antibody against 68 kDa neurofilament and observed under an fluorescent microscope. RGCs were classified on the basis of the size, number and length of neurites, and their survival was assayed for each treatment.

RESULTS

Confluent RMG substrates and RMG conditioned medium significantly increased the survival of cultured pig RGC. Moreover these two conditions increased the mean area of RGCs and enhanced neurite growth and elongation. Addition of BDNF to culture medium did not modify survival but increased RGC size, neurite number and neurite length.

CONCLUSIONS

These findings demonstrate that factor(s) secreted by RMG exert beneficial effects on adult RGC survival and neurite regeneration in vitro, and might constitute important agent(s) for RGC neuroprotection. BDNF also increases the mean area of RGCs and enhances neurite growth but it does not increase the survival of RGCs.

[Usefulness of olanzapine in the levodopa-induced psychosis in patients with Parkinson's disease]

BACKGROUND

To evaluate the antipsychotic efficacy of olanzapine (OLZ) in patients with Parkinson's disease (PD) and drug-induced psychosis (DIP) and its repercussion on the motor function.

METHODS

Ten patients (5 women and 5 men) diagnosed of PD and DIP, aged 67 years (range: 50-81), with PD duration of 11.1 years (range: 6-23), treated chronically with levodopa per day, received a dose of 2.5 or 5.0 mg OLZ daily. Data concerning improvement of psychosis and worsening of motor function was based on Positive And Negative Symptoms Scale (PANSS) and Unified Parkinsons Disease Rating Scale (UPDRS) motor.

RESULTS

Psychotic symptoms were improved in all patients. In most of them the improvement was almost total. Seven patients increased levodopa dose on OLZ, but significant worsening of motor function was reported just in one patient. None of the patients had agranulocytosis in the blood monitoring. Two patients presented weight gain. Seven patients improved their cognitive status.

CONCLUSIONS

We conclude that OLZ at the doses studied may have efficacy for DIP which appears in PD and does not induce worsening of motor function in most of the patients.

[Acute hepatitis due to ticlopidine. A report of 12 cases and review of the literature]

OBJECTIVE

To analyze the characteristics of hepatotoxicity due to ticlopidine.

PATIENTS AND METHODS

We describe all the case of hepatotoxicity attributed to ticlopidine and reported to the Register of drug associated hepatopathies. We also obtained data from MEDLINE and the Spanish Medical Index regarding cases reported during the period 1982 2001.

RESULTS

We reported twelve cases of hepatopathy related to the use of ticlopidine. These made up 5% of all the cases notified to the Register. Eighty three percent of the patients were male, and of an average age of 68 years. Sixty six percent required hospital admission. The latent period varied between 2 and 13 weeks. The liver lesion was of cholestatic type in 75% of the cases, hepatocellular in 16.6% and mixed in 8.3%. Twenty five percent of the patients had received sub therapeutic doses.

CONCLUSIONS

Ticlopidine is often related to hepatotoxicity. This seems to be due to an idiosyncratic mechanism and is mainly cholestatic. The use of lower dosage than that recommended means that the desired therapeutic effect is not attained but does not protect against the development of hepatotoxicity. Doctors who use this drug should be aware of this so as to establish the true risk benefit relation.

Probable diltiazem-induced acute interstitial nephritis

OBJECTIVE

To describe a case of acute interstitial nephritis (AIN) probably related to administration of diltiazem.

CASE SUMMARY

A 53-year-old white man presented to the hospital experiencing abdominal pain radiating to both renal fossae, as well as dysuria. Diltiazem and atenolol had been prescribed to treat an episode of precordial pain associated with effort. An erythematous maculopapular rash developed approximately 2 hours after administration of a single dose of diltiazem, and acute renal failure, associated with elevated liver function test results, developed 6 days later.

DISCUSSION

To the best of our knowledge, this is the third reported case of acute renal failure believed to be induced by diltiazem. In all cases, there was an obvious temporal relationship between administration of diltiazem and the onset of acute renal failure. Previous reports failed to discuss a probable pathogenic mechanism. AIN is the most likely etiology of acute renal failure in our patient. Favorable resolution with no relapse, the presence of the skin rash, and the liver sequelae suggest a common immunoallergic mechanism.

CONCLUSIONS

Healthcare professionals should consider diltiazem-induced AIN in the differential diagnosis of a patient taking diltiazem who develops acute renal failure.

H1-antihistamines and prescription compliance

H1-antihistamines (H1A) have been used for more than 50 years in the treatment of allergic pathology. Their widespread consumption and the growing pharmaceutical offer is noteworthy. Despite this, we have not found any study on the compliance of these drugs in the scientific literature reviewed. The aims of this study are to evaluate compliance with the prescription of H1A in a sample of allergic patients diagnosed as pollen rhinoconjunctivitis (PRC), and to evaluate the possible association between the degree of compliance and certain patient-dependent parameters (age, sex, cultural level, knowledge of the prescription and treatment [duration, number of drugs, posology, method of administration and appearance of adverse drug reactions]). The sample size was 300, and 164 were attended. Of these 164 patients, 123 claimed to have taken correctly the H1A prescribed by the allergologist. Of the group of patient claiming to have followed treatment correctly, only 8 patients did not remember the number of packs of H1A bought, nor their price, nor the appearance of the tablets (or solution). Regarding the frequency of use, 101 patients took the H1A daily, and the remaining 22, depending on symptoms. Administration of the H1A was always oral-tablets in 114 cases and solution in 9. The compliance we have found is at a medium level, similar to that reported in other studies (although on other drugs), and no significant differences were found in relation to the parameters studied.

Heparin inhibits Pseudomonas adherence to soft contact lenses

Adherence of bacteria to the surface of contact lenses may play an important role in contact lens intolerance and corneal infections. To decrease the capability of bacteria to adhere to contact lenses we incubated two types of soft contact lenses with two strains of Pseudomonas aeruginosa (serotypes 0:11 and 0:8) at a concentration of 5 x 10(7) c.f.u./ml for 12 hours. When heparin was added to the medium at a concentration of 1000 IU/ml the numbers of bacteria adhering to the contact lenses were significantly fewer than in the controls (p < 0.005). Our results suggest that heparin, either included in contact lens solutions or bonded to the surface of the contact lens, may decrease contact-lens-related morbidity.

Total and free valproic acid: plasma level/dose ratio in monotherapy

Free plasma level/dose ratio of valproic acid (L/D-F) can be more effective than total plasma level/dose ratio (L/D-T) in adjusting dosage regimens. The influence of age, dose, and plasma concentration have been studied on L/D-T and L/D-F ratios. L/D-T and L/D-F ratios from 67 outpatients under long-term monotherapy were obtained. Analytical data was carried out by fluorescent polarized immunoassay. L/D-T and L/D-F ratios do not vary according to age. L/D-T and L/D-F ratios decreased while the dosage increased; both ratios increased with an increase in total plasma level of valproic acid. Significant differences were found between L/D-T and L/D-F ratios. Dose and interindividual variations are the factors which most influence L/D ratios of valproic acid.

Idiopathic lipid corneal degeneration

Two patients with no history of eye disease or systemic disorder exhibited bilateral corneal lipid annular infiltrates, together with deep stromal vascularization. Penetrating keratoplasty was performed on one eye of each patient, and one patient presented with an acute graft rejection.

Crescentic resection for the treatment of pellucid corneal marginal degeneration

The left eye of a patient with bilateral pellucid marginal corneal degeneration was treated by crescentic resection of the affected part. The treatment, while it has not been monitored over the long term, appears to have many advantages over penetrating keratoplasty.

Toxic psychosis following cycloplegic eyedrops

A case of toxic psychosis due to cycloplegic eyedrops is reported. The characteristic mental symptoms of atropine intoxication include confusion with vivid visual hallucinations, restlessness, muscular incoordination, and later emotional lability. These symptoms and a short period of retrograde amnesia occurred in our patient. The adverse drug reaction was confirmed following rechallenge. The possible preventive measures against intoxication caused by atropine eyedrops are described. All healthcare professionals should be aware of the possible temporal relationship between the appearance of pathology and the administration of a drug.

Fusarium moniliforme keratitis

We report a case of keratomycosis from which fusarium moniliforme was isolated. After initial therapy without improvement, antifungal testing showed susceptibility to cyclopiroxolamine. After changing to this treatment the infection improved and an eventual healing took place with moderate corneal scarring.

Factors modifying valproate plasma level/dose ratio: age, sex, dose and plasma level

Valproate plasma level/dose (L/D) ratios obtained from 155 outpatients under long-term monotherapeutic regimen have been studied. Analytical data were obtained by enzymatic immunoassay (EMIT) from paired samples taken before the morning drug dosage. L/D ratios were increased with age and plasma level and decreased with dose. There were no sex differences in L/D in the different age, dose and concentration groups. L/D ratios were higher than those found by other researchers in our country.

Phenobarbital plasma level/dose ratio in monotherapy. Influence of age, sex and dose

Phenobarbital plasma level/dose ratio (L/D) has been studied in 536 outpatients distributed in groups according to age, sex and drug dosage. Samples were obtained prior to the first morning dose. Plasma levels that correspond to the steady-state phase were determined by homogeneous enzymatic immunoassay (EMITR). From the results it must be pointed out: 1) An increase of L/D as the age increases within each group; 2) A decrease of L/D as the dose of phenobarbital increases in the overall sample; 3) Sex does not affect L/D in any of the subgroups studied; 4) For a given dose higher blood levels are reached in children 7 to 15 years old in our sample than in other comparable studies in Spain.

[Preventive treatment of convulsions in perinatal asphyxia]

A double blind randomized study has been performed in 17 newborn infants bearing a diagnosis of perinatal asphyxia and treated with phenobarbital (FB) or phenytoin (DPH) to prevent the onset of seizures. The initial dose for both drugs was 12 m/kg IM the first day, followed by 6 mg/kg/day through the seventh day. Patients were clinically assessed daily and drug blood levels were also determined daily by enzyme immunoassay (EMIT). Mean FB levels along the seven days were 17.6, 23.7, 25.6, 31.6, 31.4, 36.7, and 44.6 micrograms/ml. One child treated with FB exhibited seizures on the second day and six children showed drowsiness and bradycardia on the last two days, that were attributable to high levels of FB. Mean (DPH) levels along the study were: 4.6, 7.0, 9.7, 6.5, 4.5, and 5.2 micrograms/ml. Seizures occurred in one of the DPH-treated patients and signs of therapeutic inefficacy such as hypertonus and abnormal movements appeared in four children.

Hydrogel contact lens-induced Pseudomonas keratitis in a rabbit model

Unused soft contact lenses (SCL) containing 38.6% water (polymacon) and 70% water (lidofilcon A) were exposed to Pseudomonas aeruginosa (10(8) CFU/ml) for 60 min and washed. The contaminated lenses were used on rabbit eyes under the following conditions: for 1 h on a scratched corneal epithelium (16 eyes, four infected), for 24 h on normal cornea (eight eyes, none infected), and for 7 days on normal cornea (eight eyes, three bacterial infections and two noninfected epithelial defects). A control group of rabbits used an uncontaminated lens for 7 days (eight eyes, four noninfected epithelial defects). The control group and groups that wore contaminated lenses for 24 h and 7 days underwent tarsorrhaphy to keep the contact lens in place. In addition, three drops of the bacterial suspension were instilled in eyes with normal corneal epithelium (eight eyes, none infected) and scratched corneal epithelium (16 eyes, 13 infected). Results suggest that Pseudomonas-contaminated SCL give rise to keratitis only on an injured corneal epithelium and that a bacterial suspension is more pathogenic to the rabbit cornea than is a similar amount of bacteria on an SCL.

Steady-state carbamazepine plasma concentration-dose ratios in epileptic patients

The distribution of carbamazepine plasma concentration-dose ratio was studied in 322 samples from patients undergoing long term treatment. Data have been grouped according to: age--3 to 6, 7 to 9, 10 to 14, and above 15 years old; number of drugs used in the treatment--mono- and polytherapy; dose--less than or equal to 10, 10.1 to 14.9, 15 to 19.9, and greater than or equal to 20 mg/kg; and plasma concentration found--less than 4, 4 to 8, 8.1 to 12, and greater than 12 mg/L. From the results it is concluded that the carbamazepine concentration-dose ratio increases with age in children, but is less than in adults, is higher in monotherapy than in polytherapy, and decreases as the dose increases.

Protective effect of GABA and sodium valproate on stress-induced gastric lesions in guinea-pigs

gamma-Aminobutyric acid (GABA) and sodium valproate (VPA) inhibit the formation of stress-induced gastric ulcers in guinea-pigs. The present study was conducted to evaluate the effect of these drugs on the development of cold- and restraint-induced gastric ulcers in guinea-pigs. In control saline-pretreated animals, a 3 h exposure to cold and restriction resulted in the production of gastric ulcers in 9 out of 10 animals. GABA (200 mg kg-1 oral, i.p.) completely prevented the development of gastric ulcers. VPA (100 and 200 mg kg-1 i.p.) exerted no significant effects on the development of gastric ulcers. GABA (100 mg kg-1 oral and i.p.) and VPA (oral) also exhibited partially protective activity. It is suggested that GABA may participate in a physiological modulation of the gastric mucosal barrier, by increasing its resistance to stress-induced lesions.

Involvement of bicuculline-insensitive receptors in the hypothermic effect of GABA and its agonists

GABA, delta-aminovaleric acid (DAVA) and sodium valproate (VPA) decrease core temperature in conscious rats. Bicuculline increases GABA-induced hypothermia, does not modify DAVA (250 mg/kg) and VPA (100 and 400 mg/kg) hypothermia and antagonizes initial hypothermia by DAVA (1000 mg/kg) and VPA (200 mg/kg) and late hypothermia by DAVA (500 mg/kg) and VPA (200 mg/kg). Picrotoxin increases late hypothermia by GABA (250 mg/kg) and VPA (400 mg/kg), but decreases initial hypothermia by VPA (200 mg/kg). Pentylenetetrazol increases variably GABA-induced hypothermia, inhibits early early hypothermia by DAVA and increases hypothermia induced by VPA (400 mg/kg). We conclude that GABA and GABA-agonists (DAVA and VPA) may induce hypothermia partly mediated by activation of bicuculline-insensitive GABA-receptors.

Cyst of accessory lacrimal gland

We present a case of an epithelial cyst of the conjunctiva caused by the dilatation of an accessory lacrimal gland. The case is peculiar in regard to the size of the cyst and the absence of traumatic or inflammatory factors to explain the retention of fluid.