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Biomedical subjects

A A Cruz

Publications and source records attributed to A A Cruz.

At least 37 records · Page 2Linked to original sources
PubMed1998

Digital image processing measurement of the upper eyelid contour in Graves disease and congenital blepharoptosis.

OBJECTIVE: This study used image processing techniques to quantify the upper eyelid contour of patients with Graves upper eyelid retraction and congenital blepharoptosis. DESIGN: The study design was a cross-sectional study. PARTICIPANTS: A total of 29 patients with Graves disease, 22 patients with congenital blepharoptosis, and 50 patients with no history of eye disease participated. INTERVENTION: The images of the palpebral fissure of all participants were transferred to a personal computer and processed with NIH Image 1.55 software. MAIN OUTCOME MEASURES: The following parameters were analyzed: the curvature of the upper eyelid contour, the position of the contour peak relative to the midline, and the ratio between the temporal and nasal upper quadrant areas of the palpebral fissure. RESULTS: All upper eyelid contours could be fitted with second-degree polynomial functions. The mean temporal/nasal area ratio was 1.33 mm in patients with Graves disease, 0.92 mm in patients with blepharoptosis, and 1.04 mm in control subjects. The peak of the upper eyelid contour was found to be lateral to the midline in control subjects (1.05 mm) and in patients with Graves disease (2.09 mm). In patients with blepharoptosis, the peak was 0.69 mm medial to the midline. Overall, the distance between the midpupil and the upper eyelid margin was correlated with several factors: the degree of curvature, the position of the peak of the eyelid contour, and the temporal/nasal area ratio. CONCLUSIONS: In Graves eyelid retraction, the curvature of the upper eyelid is enhanced, the peak of the contour is displaced laterally, and the temporal upper quadrant area is increased. Conversely, in congenital blepharoptosis, the eyelid is almost flat, the peak of the contour is displaced medially, and the upper quadrant area is diminished. The lateral segment of the upper eyelid is more involved than the nasal segment in both Graves upper eyelid retraction and congenital blepharoptosis.

Adolescent↗
PubMed1998

Eyelid changes in long-standing leprosy.

To describe eyelid changes in ocular leprosy, 74 patients (148 eyes or 296 eyelids) were examined, focusing on eyelid abnormalities. The adnexal examination included evaluation of the upper eyelid crease pattern, qualitative assessment of the orbicularis oculi muscle function, measurement of the distance between the corneal reflex and the upper eyelid margin (margin reflex distance), and slit-lamp biomicroscopy of the eyelashes and tarsal conjunctiva. Eyelash ptosis was a common finding associated with a multiple upper eyelid crease pattern and trichiasis. In the past, eyelash ptosis has probably been diagnosed as upper eyelid entropion or trichiasis, but in this series entropion was not observed. The distinction between eyelash ptosis, trichiasis, and upper eyelid entropion is important because the surgical management for each is different. Other true leprotic abnormalities of the eyelids are lagophthalmos and lower lid ectropion.

Adult↗
PubMed1998

Levator aponeurosis surgery in Schwartz-Jampel syndrome.

Schwartz-Jampel syndrome is a rare disorder with prominent palpebral fissure changes. These changes are complex and have been described as ptosis, blepharophimosis, and blepharospasm. Two new cases of the Schwartz-Jampel syndrome and the results of elevating the upper eyelid margin with levator aponeurosis surgery are presented, along with a review of the literature.

Blepharophimosis↗
PubMed1997

Analysis of the in vivo decay of the Escherichia coli dicistronic pyrF-orfF transcript: evidence for multiple degradation pathways.

Messenger RNA decay in Escherichia coli is slowed in pnp-7 (PNPase) rnb-500 (RNase II) rne-1(RNase E) multiple mutants. We have used Northern blots, S1 nuclease protection and primer extension analysis to map 18 endonucleolytic cleavage sites within the pyrF-orfF dicistronic transcript. Although examination of a total of 27 cleavage sites including those determined for the monocistronic trxA transcript revealed a complex pattern, the central four nucleotides within a cluster of 12 residues encompassing the cleavage sites showed a definite A/U preference. Also of interest was the processing of the dicistronic transcript to remove the downstream orfF sequence as a stable but untranslated RNA fragment. The data provide further support for the hypothesis that multiple decay pathways are involved in the decay of a single transcript. In particular, the pyrF-orfF transcript apparently can be degraded either in the 5' to 3' or the 3' to 5' direction. Our results are discussed in light of current models of mRNA decay involving polyadenylation and multiprotein decay complexes.

Endoribonucleases↗
PubMed1996

A new role for RNase II in mRNA decay: striking differences between RNase II mutants and similarities with a strain deficient in RNase E.

The effect of Escherichia coli ribonuclease II and polynucleotide phosphorylase was analysed on the degradation of Desulfovibrio vulgaris cytochrome c3 (cyc) mRNA. In the absence of these exoribonucleolytic activities, cyc mRNA was stabilised but the two enzymes had a different role in its decay. Surprisingly, a temperature-sensitive mutation in ribonuclease II gave a degradation pattern similar to what had been observed in the absence of endoribonuclease E activity. In an RNase II deletion mutant this was not observed. We propose and verify a model in which the temperature-sensitive ribonuclease II interferes with the action of ribonuclease E.

Antibiotics, Antitubercular↗
PubMed1996

Degradation products of the cytochrome c3 mRNA are similar in Desulfovibrio vulgaris Hildenborough and Escherichia coli.

The transcription and mRNA degradation pattern of a cloned Desulfovibrio vulgaris (Dv) Hildenborough cytochrome c3-encoding gene (cyc) was analyzed in detail, both in Escherichia coli and its native species. Transcription in Dv seems to be controlled by the same promoter elements as in E. coli; the transcription start point (tsp) of this Dv gene has been mapped in both species and found to be identical. A major putative transcription terminator was mapped and it was found to be the same in both organisms. Furthermore, the intermediates in cyc mRNA degradation are similar in both bacterial species.

Chromosome Mapping↗
PubMed1996

RNase E can inhibit the decay of some degradation intermediates: degradation of Desulfovibrio vulgaris cytochrome c3 mRNA in E coli.

In Escherichia coli, ribonuclease E (RNase E) is a key endonuclease in mRNA decay. We have analysed the role of E coli RNase E on the degradation of a heterologous cytochrome c3 (cyc) mRNA from Desulfovibrio vulgaris Hildenborough. The decay of the cyc transcript in wild-type and mutant E coli cells was followed and the degradation intermediates analysed by Northern blotting and S1 protection analysis. The half-life of total cyc mRNA intermediates was increased in the RNase E mutant. A number of degradation intermediates were stabilised, and new species arose. However, some species decayed faster in the met5 mutant at the non-permissive temperature, suggesting that RNase E might inhibit their degradation. The results indicate that RNase E is involved in cyc mRNA degradation, and, interestingly, decay of certain intermediates could be reduced by this enzyme activity. This may suggest a functional interaction between RNase E and exonucleases, like polynucleotide phosphorylase.

Blotting, Northern↗
PubMed1995

Palpebral fissure height and downgaze in patients with Graves upper eyelid retraction and congenital blepharoptosis.

PURPOSE: To compare the relation between vertical eyelid fissure height and downgaze in healthy subjects and in patients with Graves upper eyelid retraction and congenital blepharoptosis. METHODS: With a caliper rule, the authors measured the vertical eyelid fissure height of 25 patients with no previous history of eye disease, 34 patients with Graves disease, and 16 patients with congenital blepharoptosis. All measurements were done at the primary position and at four levels of downgaze (10 degrees, 20 degrees, 30 degrees, and 40 degrees). In 13 patients with Graves disease, vertical phoria was quantified with a Maddox rod and prism. RESULTS: The relation between vertical eyelid fissure height and downgaze is linear. The slope was identical for the control subjects and for the patients with Graves disease (b = -1.36) but it was almost zero for the patients with congenital blepharoptosis (b = -0.037). When vertical eyelid fissure height was corrected to arc values, the slope of the relation between vertical eyelid fissure height and downgaze was significantly greater for the patients with Graves disease. Vertical phoria was not related to the amount of Graves upper eyelid retraction. CONCLUSIONS: The data support the hypotheses that upper eyelid retraction secondary to Graves eye disease results from hyperactivity of the levator palpebrae superioris muscle.

Adolescent↗
PubMed1995

Congenital shortening of the anterior lamella of all eyelids: the so-called ablepharon macrostomia syndrome.

The so-called ablepharon macrostomia syndrome is an extremely rate congenital condition that includes abnormal ears, an enlarged, fishlike mouth, absence of lanugo, redundant skin, and vertical shortening of all eyelids. Only four cases have been described so far. In these cases the nature of the eyelid anomalies has not been clearly defined. We report one more case showing that the condition is better described as a severe microblepharon because only the anterior lamella of the eyelids is shortened. The literature about this condition is reviewed, and oculoplastic treatment is discussed.

Adolescent↗
PubMed1994

The development of eye alignment, convergence, and sensory binocularity in young infants.

PURPOSE: To measure and compare the development of ocular alignment, sensory binocularity, and convergence in infants during the first 5 months of life. METHODS: Healthy infants were tested between 2 and 21 weeks of age. Ocular alignment was measured by the Hirschberg test; convergence was determined by visual examination as an illuminated toy approached an infant's face; and sensory binocularity was measured by preferential looking for fusible versus rivalrous gratings. In experiment 1 we compared the proportion of infants at different ages demonstrating orthotropic ocular alignment with those showing convergence. In experiment 2, we compared the age of onset of convergence to that of sensory binocularity. RESULTS: Experiment 1: Most infants were orthotropic during the first month, and almost all of the others showed small amounts of exotropia. None of the infants showed accurate convergence until 6 weeks of age. By 4 months of age virtually all were orthotropic and had good convergence. Experiment 2: The onset of sensory binocular fusion occurred at 12.8 +/- 3.3 weeks. Full convergence did not occur until 13.7 +/- 3.2 weeks, although the first signs of convergence occurred slightly earlier. For individual infants there was a high correlation between the age of onset of sensory binocularity and convergence, and both onsets occurred earlier in girls than in boys. CONCLUSIONS: Ocular alignment did not require the development of binocularity mechanisms, and the development of binocularity mechanisms did not await the onset of good ocular alignment. The relatively sudden onset of binocularity, both sensory (preference for fusion and stereopsis) and motor (convergence) at about 3 months of age and the high correlation between these measures indicate a common causal mechanism that probably involves refinements in striate cortex circuitry.

Child Development↗
PubMed1992

Tryptase and histamine as markers to evaluate mast cell activation during the responses to nasal challenge with allergen, cold, dry air, and hyperosmolar solutions.

We have used assays for histamine and for the specific mast cell enzyme, tryptase, to examine the response of the nasal mucosa to provocation with several different stimuli and to evaluate the reliability of histamine as a marker of mast cell activation. High levels of histamine detected in baseline lavages of some subjects are not associated with any detectable tryptase, suggesting they are not mast cell derived. During pronounced immediate allergic responses, however, mast cell degranulation clearly occurs, and a striking correlation between histamine and tryptase is observed. This correlation is weaker when a more modest allergic response is induced, possibly reflecting differential diffusion of the two mediators across the epithelium. Provocation of susceptible individuals with cold, dry air leads to increased recoveries of both histamine and tryptase, confirming that mast cell degranulation occurs during this reaction. Although hyperosmolarity of the nasal mucosa may contribute to mast cell degranulation induced by cold, dry air, a brief exposure of the nasal cavity to hyperosmolar mannitol was not associated with measurable production of tryptase. The combined use of histamine and tryptase measurements can therefore provide useful evidence regarding the role of mast cell activation in the pathogenesis of inflammatory responses.

Adult↗
PubMed1992

Intranasal beclomethasone inhibits antigen-induced nasal hyperresponsiveness to histamine.

To determine whether intranasal steroid treatment inhibits the increased sensitivity to histamine that occurs 24 hours after nasal antigen challenge, 12 allergic volunteers were entered into a double-blind study comparing placebo or 164 micrograms of beclomethasone dipropionate twice a day for 7 days. Beclomethasone dipropionate partially reduced the early mediator response to antigen and the influx of eosinophils 24 hours later. Comparing the initial histamine challenge with that done 24 hours after antigen with the subjects on placebo, there was a significant increase in sneezes, TAME-esterase activity, and albumin. Pretreatment with intranasal beclomethasone dipropionate resulted in a reduced response to histamine 24 hours after antigen challenge. A positive correlation occurred between the number of eosinophils in the lavage before histamine challenge and the level of TAME-esterase activity (rs = 0.67, p = 0.03) during the histamine challenge that followed antigen with the subjects on placebo. We thus confirmed the increase in nonspecific nasal airway responsiveness 24 hours after antigen challenge, with a concomitant increase in eosinophils, and demonstrate its inhibition by pretreatment with intranasal steroids.

Administration, Intranasal↗
PubMed1992

Local application of atropine attenuates the upper airway reaction to cold, dry air.

In some individuals, inhalation of cold, dry air (CDA) provokes symptoms of rhinitis, accompanied by an increase in the levels of inflammatory mediators and markers of plasma leakage of recovered nasal lavages. Because rhinorrhea is a major component of this reaction and because nasal glands are heavily innervated by the parasympathetic system, we assessed the effect of atropine on the nasal reaction to CDA. Using a double-blind, randomized, crossover design, we administered a total dose of 0.5 mg of atropine or placebo intranasally to 18 volunteers before provocation with CDA. The reaction was monitored with symptom scores and by measuring the concentrations of histamine, N-alpha-p-tosyl-L-arginine methyl ester (TAME)-esterase activity and albumin, as well as the osmolality of lavage fluids before and after the provocation. Atropine significantly reduced rhinorrhea, the levels of histamine, and TAME-esterase activity as well as the osmolality of recovered lavage fluids, but had no effect on nasal congestion or albumin. Even with atropine, however, rhinorrhea and TAME-esterase activity were still significantly increased over the prechallenge baseline. Our results demonstrate that atropine-sensitive parasympathetic efferent pathways contribute to the CDA-induced rhinitis. We speculate that (1) the glandular and the vascular events of the upper airway reaction to dry air have different pathophysiologic mechanisms; (2) a significant component of TAME-esterase activity in lavage fluids may be of glandular origin; and (3) in addition to parasympathetic nerve activation, other mechanisms are involved in the upper airway reaction to dry air. The mechanism(s) leading to the reduction of histamine is unknown.

Administration, Intranasal↗
PubMed1991

Inhibition of binocular contrast sensitivity in hypermetropic anisometropia.

Binocular contrast inhibition can occur when the monocular contrast sensitivities are not equal. It has been reported in cases of monocular cataracts. Our case is an 18-year-old female with 3.50 D of hypermetropic anisometropia. She was not amblyopic but showed a typical binocular contrast inhibition.

Adolescent↗
PubMed1991

Steroid-induced reduction of histamine release does not alter the clinical nasal response to cold, dry air.

In some persons, cold, dry air (CDA) provokes symptoms of rhinitis that are associated with increased levels of histamine and other inflammatory mediators in nasal lavages. Because the patterns of mediators released during the early reaction to antigen and CDA-induced rhinitis are similar, we believe that mast cell activation is part of the reaction to CDA. In view of our previous finding that 1-wk pretreatment with topical steroids reduced symptoms and mediator release in the early nasal response to antigen of allergic subjects, we examined the effect of beclomethasone dipropionate on the response to CDA. Using a double-blind, crossover design, 84 micrograms of beclomethasone or placebo were administered in each nostril twice a day to 13 volunteers for 7 days prior to CDA challenge. The reaction to CDA was monitored by measuring the levels of histamine, N-alpha-p-tosyl-L-arginine methyl ester (TAME)-esterase activity and albumin in nasal lavages before and after provocation. Overall symptom scores, as well as scores for rhinorrhea and congestion, were also obtained. Cold, dry air challenge resulted in elevation over baseline of all parameters after placebo pretreatment. After beclomethasone, a significant reduction in histamine levels, but not in TAME-esterase activity or albumin levels or in number of symptoms, was observed. These results indicate that 1-wk pretreatment with beclomethasone affects mast cells, reducing histamine release after CDA, as it did in antigen-induced rhinitis. They also indicate that histamine may not be essential for the development of the immediate nasal reaction to CDA.

Adult↗
PubMed1991

Surgical correction of trachoma-related upper eyelid cicatricial entropion utilizing the Barbera-Carre technique.

Upper eyelid cicatricial entropion is commonly encountered as a sequela of inflammatory conditions. The surgical correction of this defect is often difficult and frequently unsuccessful. We have used the Barbera-Carre technique with good results in 20 patients with cicatricial entropion due to trachoma. We take this opportunity to present the surgical technique and our results.

Adult↗
PubMed1990

Conjunctival vessel abnormalities in sickle cell diseases: the influence of age and genotype.

Conjunctival vessels were examined with a slit-lamp and the abnormalities were graded in 77 patients with sickle cell diseases, including 48 with sickle cell anaemia, 17 with sickle cell beta (0)-thalassaemia and 12 with HbS/HbC disease. The study demonstrated the occurrence of similar conjunctival vessel abnormalities for the three sickle cell diseases which are, however, more severe in HbS homozygotes than in the two other genotypes. An increase of the severity of the vascular abnormalities with the increase of patient age was also observed for HbS homozygotes. The data suggest that the conjunctival lesions accumulate and increase in severity in a similar fashion as other tissue damages observed in sickle cell diseases.

Adolescent↗