Biomedical subjects

G Cennamo

Publications and source records attributed to G Cennamo.

At least 19 recordsLinked to original sources

PubMed1999

Protein and gene structure of a blue laccase from Pleurotus ostreatus1.

A new laccase isoenzyme (POXA1b, where POX is phenol oxidase), produced by Pleurotus ostreatus in cultures supplemented with copper sulphate, has been purified and fully characterized. The main characteristics of this protein (molecular mass in native and denaturing conditions, pI and catalytic properties) are almost identical to the previously studied laccase POXA1w. However, POXA1b contains four copper atoms per molecule instead of one copper, two zinc and one iron atom per molecule of POXA1w. Furthermore, POXA1b shows an unusually high stability at alkaline pH. The gene and cDNA coding for POXA1b have been cloned and sequenced. The gene coding sequence contains 1599 bp, interrupted by 15 introns. Comparison of the structure of the poxa1b gene with the two previously studied P. ostreatus laccase genes (pox1 and poxc) suggests that these genes belong to two different subfamilies. The amino acid sequence of POXA1b deduced from the cDNA sequence has been almost completely verified by means of matrix-assisted laser desorption ionization MS. It has been demonstrated that three out of six putative glycosylation sites are post-translationally modified and the structure of the bound glycosidic moieties has been determined, whereas two other putative glycosylation sites are unmodified.

Amino Acid Sequence↗

PubMed1998

Goldmann applanation tonometry after myopic photorefractive keratectomy.

PURPOSE: To determine the accuracy of applanation tonometry in patients with corneas thinned by photorefractive keratectomy, and to correlate corneal changes with tonometric readings. METHODS: The intraocular pressure was measured with Goldmann applanation tonometry in 87 patients who underwent photorefractive keratectomy before and 1, 6 and 12 months after treatment. The treatments ranged from -1.5 to -14 diopters (mean=-7.6+/-4.1 diopters) and the fellow eyes were used as controls. RESULTS: In the treated eyes the intraocular pressure before surgery ranged from 11 to 26 mmHg (mean=17.7+/-2.8 mmHg). One month after surgery it ranged from 5 to 22 mmHg (mean=11.9+/-2.7 mmHg) with a significant underestimation (P=1x10(-33)). Six months after surgery it ranged from 6 to 22 mmHg (mean=12+/-3 mmHg) with a significant underestimation (P=5x10(-30)). Twelve months after surgery it ranged from 8 to 22 mmHg (mean=12.7+/-2.7 mmHg) with a significant underestimation (P=5x10(-31)). CONCLUSIONS: A correcting factor should be applied when using applanation tonometry to measure intraocular pressure in patients who have undergone PRK.

Adolescent↗

PubMed1998

In vitro evaluation of a new echographic contrast agent.

BACKGROUND: So far, intravenously injected echographic contrast agents have not been able to overcome the lung circle, and their use was confined to the study of right-sided heart abnormalities. A new agent that is able to pass the pulmonary barrier has been manufactured, and it is currently under investigation in ophthalmology. METHODS: A saccharide-based contrast agent (SHU 454) that is not able to overcome the lung filter has been compared in vitro with a new saccharide-based contrast agent (SHU 508 A) that is able to overcome the pulmonary barrier. They have been diluted in saline solution, and the reflectivity of the solution and the eventual sound attenuation have been studied with standardized A scan and a tissue model. RESULTS: The solution with SHU 508 showed a higher reflectivity that lasted longer, without significant sound attenuation. CONCLUSIONS: The long-lasting period of the increased reflectivity will allow to better evaluate the normal and pathological vascular network in the eye and orbit, such as the evaluation of the effectiveness of conservative treatment in cases of malignant melanoma with a spread of the indications of standardized echography to other fields of ophthalmology.

Contrast Media↗

PubMed1998

Power doppler ultrasonography in ocular and orbital diseases.

PURPOSE: The authors present a preliminary report to test the usefulness of a new technique called power Doppler ultrasonography (PD) in the study of orbital vessels. MATERIAL AND METHODS: The ophthalmic artery and vein as well as the central retinal artery and vein have been examined in 10 patients with a General Electric Logiq 5000 that allows the examination with both color Doppler ultrasonography (CD) and PD. RESULTS: PD does not alias, is relatively angle independent and is able to better detect the pathways of these vessels. CONCLUSIONS: PD is a new promising technique that may be superior to CD in detecting orbital and ocular vessels.

Blood Flow Velocity↗

PubMed1997

The corneal endothelium 12 months after photorefractive keratectomy in high myopia.

PURPOSE: To determine if photorefractive keratectomy with a 193 nm excimer laser could cause human corneal endothelial changes, mainly in high dioptric treatments. METHODS: 18 patients underwent a treatment ranging from 7 to 13 diopters at the corneal apex (mean 10.3 +/- 1.4 SD) with an estimated corneal thinning ranging from 62 to 116 microns (mean 90.7 +/- 12 SD). In these patients a comparison between the number and shape of the corneal endothelial cells has been performed before and 12 months after PRK. RESULTS: The mean cell density was 2818 +/- 337 mm2, before surgery, and 2894 +/- 301 mm2 after 12 months. The polymorphic index was 79.0 +/- 2.3, before surgery, and 81.0 +/- 5.0 after 12 months with no significant changes (p = 0.16 and P = 0.09, respectively). CONCLUSIONS: These results show that photorefractive keratectomy does not cause any significant observable damage to the central corneal endothelium up to 12 months after surgery, even in high myopic treatments.

Adult↗

PubMed1997

Use of a special device for the treatment of overfiltration after glaucoma filtering surgery.

BACKGROUND: standardized A and B scan echography were used to look for the possible presence of ciliochoroidal detachment in patients with flat anterior chamber following glaucoma filtering surgery. For this purpose, a scleral shell filled with saline solution was inserted between the lids. As a deepening of the anterior chamber was found in some patients, we planned to utilize these devices for the treatment of flat anterior chambers after glaucoma filtering surgery. METHODS: 16 patients with flat anterior chambers after glaucoma filtering surgery underwent the insertion of a scleral shell filled with saline solution between the lids. The shell was left in place for 15 min. RESULTS: In all of our patients a deepening of the anterior chamber was achieved. In 5 patients 1 application, in 6 patients 2 applications, in 4 patients 3 applications were needed. CONCLUSIONS: The advantages of using this procedures are: the procedure is quick; it does not disturb the corneal epithelium; it is cheap; it does not require suturing the conjunctiva; it can be part of the examination of the anterior segment with echography to look for any ciliary body detachment.

Anterior Chamber↗

PubMed1997

Non-contact tonometry in patients that underwent photorefractive keratectomy.

To determine the accuracy of non-contact tonometry in patients with corneas thinned by photorefractive keratectomy, the authors measured the intraocular pressure with a non-contact tonometer and the corneal thickness with an ultrasonic pachymeter in 47 patients before and 9 months after photorefractive keratectomy. The patients were divided into three groups according to the degree of treatment: group I between 1 and 5 diopters (14 eyes), group II between 6 and 10 diopters (18 eyes), group III between 11 and 15 diopters (15 eyes). In the first group of patients mean intraocular pressure was 16.1 (+/-3.85) mm Hg before surgery, and 13.2 (+/-3.14) mm Hg after surgery with a significant difference (p = 0.0027). In the second group of patients mean intraocular pressure was 16.0 (+/-4.13) mm Hg before surgery and 13.0 (+/-3.0) mm Hg after surgery with a significant difference (p = 0.0045). In the third group of patients mean intraocular pressure was 17.7 (+/-3.8) mm Hg before surgery and 12.4 (+/-2.6) mm Hg after surgery, with a significant difference (p = 0.0005). In conclusion, according to our results, non-contact tonometry needs a correcting factor for measuring the intraocular pressure in patients that underwent photorefractive keratectomy, related to the degree of refractive treatment.

Adult↗

PubMed1997

Endothelial cells evaluation two years after photorefractive keratectomy.

To evaluate long-term corneal endothelium damages after myopic photorefractive keratectomy (PRK) a morphometric analysis of corneal endothelial cells was performed in 41 patients before and at least 24 months after photorefractive keratectomy. These patients underwent a treatment ranging from -2.5 to -14 dpt with a mean of 8.9 +/- 2.8 dpt at the corneal apex, with an estimated corneal thinning ranging from 23 to 123 microns with a mean of 78 +/- 24.4 microns. Our results showed that the density of endothelial cells ranged from 2,334 to 3,554/mm2 with a mean of 2,819 +/- 351/mm2 before surgery, and from 2,051 to 3,461/mm2 with a mean of 2,774 +/- 330/mm2 after surgery without any significant changes (p = 0.16). The polymorphic index ranged from 58 to 84 with a mean of 77 +/- 5.7 before PRK and from 57 to 89 with mean of 77.7 +/- 7.2 after treatment without any significant changes (p = 0.61). In conclusion, we can state that there is no long-term corneal endothelial damage after PRK even in highly myopic eyes.

Adolescent↗

PubMed1996

Refractive outcome and corneal topographic studies after photorefractive keratectomy with different-sized ablation zones.

BACKGROUND: Discrepancies may still occur between planned and actual refractive correction in eyes undergoing photorefractive keratectomy (PRK). The authors have evaluated the use of an enlarged ablation zone. METHOD: A computerized corneal analysis system has been used to compare the changes of the anterior surface of the cornea and the refractive changes before and 1, 6, and 12 months after PRK in 113 patients (119 eyes) treated with an excimer laser. The patients were divided into two groups: those treated with a mask with a 5-mm window (59 eyes), and those with a new mask with different window openings according to the degree of refraction at the corneal apex, starting from 5 mm in diameter for treatments less than 6.5 diopters (D) and from 7 mm in diameter for higher treatments (60 eyes). In the first group, treatment ranged from -2.5 to -16 D (mean +/- standard deviation. -8.5 +/- 3.24 D); in the second group, it ranged from -1 to -14 D (-7.8 +/- 3.06 D). Treatments were evaluated with a chi-square test. RESULTS: In the first group of eyes, 46% were within +/-1 D at 1 month, 37% at 6 months, and 39% at 12 months. In the second group of eyes, 73% were within +/-1 D at 1 month, 60% at 6 months, and 58% at 12 months. The comparison between these data and corneal topographic changes shows that both are more stable and predictable with the new mask compared with the 5-mm mask (P = 0.002, 0.02, 0.04, at 1, 6, and 12 months, respectively). CONCLUSIONS: The use of larger ablation zones improves the predictability and stability of refractive changes.

Adult↗

PubMed1996

Macula study with standardized echography.

At an early clinical stage, patients with cystoid macular oedema show no significant changes in their vision. This phase is described as angiographic cystoid macular oedema. Echographic macular studies have in the past years shown that the macular thickness is increased in the early stages of cystoid macular oedema. In these patients there was no evidence of cystoid macular oedema with the visual acuity test, B-scan echography and fluorescein angiography. In this paper an echographic macular study by standardized A-scan echography was performed in 537 patients before extracapsular cataract extraction and intraocular lens implantation in posterior chamber (ciliary sulcus). The results showed that this method is very sensitive in detecting patients with high risk of cystoid macular oedema.

Adult↗

PubMed1995

Effects on the corneal endothelium six months following photorefractive keratectomy.

Photorefractive keratectomy (PRK) with a 193-nm excimer laser has been shown not to destroy endothelial cells in vivo. However, this laser could damage endothelial cell metabolism, and result in damage over a longer term. In this paper, a comparison between the number and shape of corneal endothelial cells has been performed in 25 patients before and 6 months after PRK. These patients underwent treatment with myopic correction ranging from 2.5 to 17 dpt and with an estimated corneal thinning ranging from 25 to 170 microns. No significant changes in the number (p = 0.167) and shape (p = 0.075) of endothelial cells have been found. These results show that there are no long-term damages after PRK even in severely myopic eyes.

Adult↗

PubMed1994

First experience with a new echographic contrast agent.

The intravenous injection of an ultrasound contrast agent can enhance signals from blood flow. Broad toxicological and pharmaceutical studies in animals confirmed the safety and efficacy of an ultrasound contrast agent made of microparticles of galactose with stabilised microbubbles in watery suspension (SH U 508 A). In this paper 10 patients with different malignant orbital and ocular tumours have been evaluated with an echo colour Doppler machine before and after the injection of SH U 508 A. An enhancement of the Doppler signals in the lesions in different degrees has been detected. This echographic contrast agent seems to be very important not only in the evaluation of vascular lesions, but also in evaluating the effectiveness of radiotherapy in malignant tumours and could spread the echographic indications in several other ophthalmic fields.

Adult↗

PubMed1994

Phototherapeutic keratectomy in the treatment of Avellino dystrophy.

Avellino corneal dystrophy has rarely been reported in literature. It consists of a combination of granular and lattice dystrophy. Patients may complain of glare and decreased night vision with or without decreased visual acuity, depending on the degree of corneal involvement. Current treatment for this dystrophy includes bandage contact lenses for the erosions or corneal transplant in the case of decreased visual acuity. We describe the first patient with Avellino corneal dystrophy to have been treated with phototherapeutic keratectomy.

Aged↗

PubMed1994

An unusual orbital lesion: hepatoma metastatic to the orbit.

The authors describe a case of histologically proven orbital metastasis from a hepatic carcinoma in an 85-year-old patient with rapid onset of proptosis and visual loss. The clinical diagnosis of orbital metastatic lesion was established by standardized echography and CT scan. To the best of our knowledge, this is only the third histologically proven case of hepatoma metastatic to the orbit.

Aged↗

PubMed1993

Echographic and ophthalmodynamometric study in the empty sella syndrome.

A group of patients with empty sella syndrome (ESS) and visual field defect with or without visual loss has been examined with standardized echography and ophthalmodynamometric examination. The optic nerve thickness has been evaluated with standardized echography; the pressure of the central retina artery has been evaluated with ophthalmodynamometric examination with or without compression on the external carotid. Our results point out two different pathogeneses in the ESS: vascular defects or irregular endocranial hypertension.

Empty Sella Syndrome↗

PubMed1993

Optic nerve involvement in acute lymphoblastic leukemia.

Leukemic infiltration of the optic nerve is rare. We describe the diagnostic assessment and the outcome in two adult patients suffering from acute lymphoblastic leukemia with T phenotype. In both cases the leukemic involvement of the eye was observed as an isolated extramedullary relapse followed after several months by hematological relapse. CT and MRI scans were negative, while an A-scan echography of the eye clarified the diagnosis. Early radiotherapy caused recovery of visual acuity in one case. A-scan echography is the most sensitive investigation for the early recognition of ocular localization in acute leukemias.

Adult↗

PubMed1992

Standardized A-scan echography and the normal optic nerve. Experience with the new Mini A equipment.

The potential of making differential diagnosis in optic nerve disease with standardized A-Scan echography has been well established. With this technique it is possible to differentiate 'solid' and 'fluid' thickening. A few years ago a new standardized A-scan equipment was built: The Mini A. With this equipment, it is possible to distinguish spikes coming from the pia, the arachnoid, and the dura around the optic nerve, and to measure the thickness of these structures with a precision of 0.03 mm. We found dura distance 4.0-5.3 mm, arachnoid 3.2-4.0 mm, an pial diameter 2.8-3.4 mm. In this paper the authors discuss their preliminary findings in a normal population.

Adolescent↗

PubMed1992

Comparison between echographic and histological findings in choroidal malignant melanomas.

Echography is crucial in making a diagnosis of malignant melanoma when ocular media are opaque. Even with clear ocular media, standardized echography is important to confirm or to rule out a malignant melanoma in the eye. In this study the reflectivity in 27 cases of malignant melanomas has been evaluated and compared to cell type, pigmentation and number and size of blood vessels. No significant correlations have been found.

Choroid Neoplasms↗