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S Biondi

Publications and source records attributed to S Biondi.

At least 19 recordsLinked to original sources
PubMed2004

Methyl jasmonate disrupts shoot formation in tobacco thin cell layers by over-inducing mitotic activity and cell expansion.

The aim of the present study was to determine early cyto-histological events associated with the reduced number of shoots formed at the end of culture in tobacco (Nicotiana tabacum L.) thin cell layers treated with methyl jasmonate (MJ) [S. Biondi et al. (2001) J Exp Bot 52:1-12]. The results show that 0.1-10 microM MJ strongly stimulated mitotic activity early in culture relative to untreated controls. Treatment with MJ also induced anomalous mitoses. Enhanced proliferative growth was confirmed by northern analysis and in situ hybridisation using cDNA probes of the G1/S phase-specific genes ubiquitin carboxyl-extension protein (ubi-CEP), topoisomerase 1 (top1) and ribonucleotide reductase (RNR). The formation of meristematic cell clusters on day 5 was also enhanced by 1 muM MJ, but subsequent development of these cell clusters into meristemoids and shoot primordia was reduced by all MJ concentrations in a dose-dependent manner. Cell expansion was stimulated by MJ concentrations ranging from 0.001 to 10 microM; expanded cells frequently occurred around and within meristemoids and shoot primordia, and displayed thickened and suberised cell walls; cell wall thickness increased with increasing MJ concentration. These cytological events caused alterations in the tunica and stem differentiation of the shoot dome. The apparently paradoxical role of MJ, which deregulates shoot formation through a stimulation of growth events, i.e., mitotic activity and cell expansion, is discussed.

Acetates↗
PubMed2004

Prevalence of oesophagitis in patients with persistent upper respiratory symptoms.

A growing body of evidence suggests that a variety of upper respiratory symptoms (URS) are associated with gastro-oesophageal reflux (GORD). The aim of this study was to determine the prevalence of endoscopic erosive, and non-erosive, oesophagitis among patients complaining of persistent URS, in the absence of typical GORD symptoms, and to compare them with a comparison group of similar age. A group of 110 patients aged 18-75, presenting with persistent URS with no suspicion of GORD symptoms, underwent upper flexible endoscopy, with biopsy sampling for histology, and was compared with a group of 117 patients of similar age undergoing endoscopy for reasons other than GORD. Patients affected with upper airway disorders, such as posterior laryngitis, chronic sinusitis and vocal fold nodules, had a significantly higher prevalence of oesophagitis of varying degrees (31 per cent) compared to the comparison population (15.4 per cent) (p < 0.01). These data suggest that in many patients with chronic URS occult gastro-oesophageal diseases are present.

Adolescent↗
PubMed2004

Presurgical antimicrobial prophylaxis: effect on ocular flora in healthy patients.

OBJECTIVE: Evaluation of presurgical antimicrobial prophylaxis for reduction of ocular flora. SETTING: Ophthalmology Section, Department of Medicine and Surgery, University of Catania, Italy. METHODS: Three days before photorefractive keratectomy (PRK), conjunctiva of 70 healthy patients (100 eyes) were swabbed. After 3 days of instillation of ofloxacin 0.3% (3 times daily), conjunctival swabs were taken again. Bacteria were isolated and identified from each swab. RESULTS: A total of 191 independent isolates were obtained prior to antimicrobial treatment. Bacteria were isolated from all 100 eyes sampled. Gram-positive species predominated, with Staphylococcus epidermidis and Staphylococcus aureus cultured from 69% and 25% of eyes sampled, respectively. Species of the anaerobic genera Peptococcus and Peptostreptococcus were found in 22% and 14% of eyes, respectively. After prophylaxis with ofloxacin, bacteria could be cultured from only 7% of eyes (10 independent isolates). All isolates were sensitive to ofloxacin except 5 strains of S. epidermidis, which displayed intermediate sensitivity. No infections occurred after PRK. CONCLUSION: Prophylaxis by instillation of ofloxacin 0.3% 3 times daily for 3 days substantially reduced the ocular flora of 100 healthy eyes prior to refractive surgery.

Administration, Topical↗
PubMed2002

Transglutaminase activity during senescence and programmed cell death in the corolla of tobacco (Nicotiana tabacum) flowers.

Corolla life span of undetached flowers of Nicotiana tabacum was divided into stages from the closed corolla (stage 1) through anthesis (stage 5) to death (stage 9). Senescence began around stage 6 in the proximal part, concomitantly with DNA laddering. Nuclear blebbing, DNA laddering, cell wall modification, decline in protein, water, pigment content and membrane integrity were observed during senescence and PCD. Transglutaminase activity was measured as mono- and bis-derivatives of putrescine (mono-PU; bis-PU) and bis-derivatives of spermidine (bis-SD). Bis-derivatives decreased with the progression of senescence, while mono-PU increased during early senescence; derivatives were present in different amounts in the proximal and distal parts of the corolla. In excised flowers, exogenous spermine delayed senescence and PCD, and caused an increase in free and acid-soluble conjugated PA levels. Bis-PU was the most abundant PA-derivative before DNA laddering stage; thereafter, bis-PU generally decreased and mono-PU became the most abundant derivative.

Apoptosis↗
PubMed2001

Methyl jasmonate upregulates biosynthetic gene expression, oxidation and conjugation of polyamines, and inhibits shoot formation in tobacco thin layers.

The effect of methyl jasmonate (MJ) on de novo shoot formation and polyamine metabolism was investigated in thin layer explants of tobacco (Nicotiana tabacum L. cv. Samsun). A relatively low concentration of MJ (0.1 microM) enhanced explant fresh weight, but had no effect on the final number of shoots per explant while higher concentrations (1 and 10 microM) significantly inhibited organogenesis. The histological study revealed that, with increasing concentrations of MJ, the formation of meristemoids and shoot domes declined and the incidence of cell hypertrophy increased. In explants cultured with 0.1, 1 or 10 microM MJ, the endogenous levels of free putrescine, spermidine and spermine generally declined compared with controls, after 7 and 15 d. Perchloric acid-soluble conjugated polyamines accumulated dramatically during culture, but much more so in the presence of MJ than in controls. Acid-insoluble conjugated spermidine alone increased in response to the elicitor. Activities of the putrescine biosynthetic enzymes arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17) in the soluble fraction of MJ-treated explants displayed up to 3-fold increases relative to control explants. However, the most relevant increases in these enzyme activities occurred in the particulate fraction. The activity of S:-adenosylmethionine decarboxylase (SAMDC, EC 4.1.1.21), an enzyme involved in spermidine and spermine biosynthesis, was also stimulated by exposure to MJ. Northern analyses revealed MJ-induced, generally dose-dependent, increases in the mRNA levels of all three enzymes. Diamine oxidase (DAO, EC 1.4.3.6) activity was stimulated by MJ mainly in the cell wall fraction. The upregulation of polyamine metabolism is discussed in relation to the morphogenic behaviour of MJ-treated explants.

Acetates↗
PubMed2000

Laryngeal cytological aspects in women with surgically induced menopause who were treated with transdermal estrogen replacement therapy.

OBJECTIVE: To investigate the effects of estrogen replacement therapy (ERT) on laryngeal cytology in postmenopausal women. DESIGN: Prospective open clinical trial. SETTING: Outpatient menopausal clinic in the Department of Gynecology, University of Catania, Catania, Italy. PATIENT(S): Eighty-four healthy, surgically postmenopausal women, of whom 48 were treated with ERT and 36 were considered as a control group. INTERVENTION(S): Transdermal E(2) treatment by patches or gel, evaluation of laryngeal cytology with cytobrush by indirect laryngoscopy, and questionnaire for the voice history. MAIN OUTCOME MEASURE(S): Changes in cytologic aspects of laryngeal cells with respect to vaginal cytology by hematoxylin and eosin staining; subjective voice changes. RESULT(S): Sixty-seven women completed the study. Ten women from the ERT group and five from the control group dropped out because of the invasive laryngoscope method; two subjects in the control group were excluded because of pathologies of the vocal cord. Hematoxylin and eosin staining confirmed similar superficial-intermediate aspects of the cells between the laryngeal and the vaginal smears in ERT-treated women. In the control group, both smears showed aspects of atrophy-dystrophy. The ERT group had a subjectively better quality of voice than the control group. CONCLUSION(S): Our study confirms that the larynx is an estrogen target, as are vaginal cells. ERT may provide prevention and treatment of dystrophic pathologies of the vocal cords in postmenopausal women.

Administration, Cutaneous↗
PubMed1999

Indications and results of fronto-lateral laryngectomy using a combined endolaryngeal and external approach.

Patients with laryngeal anterior commissure, cord-commissure, bilateral anterior cord-commissure carcinomas (T1 and T2 N0 M0) were subjected to a new method of frontolateral laryngectomy using a combined endolaryngeal and external approach. The proposed surgical procedure allowed the removal of the anterior commissure and part of one or both vocal cords in a single unit, together with the cartilaginous framework, respecting the integrity of the superior portion of the thyroid cartilage. The internal procedure permitted an accurate delimitation of the posterior part of the laryngeal neoplasm. In particular, this was performed during suspension microlaryngoscopy using the CO(2) laser or traditional cutting tools for section of the laryngeal visceral structures to the internal surface of the thyroid cartilage. Following this, the external approach included incision of the external perichondrium along the superior edge of the thyroid cartilage and along the median line, from the incisura to the inferior edge of the thyroid cartilage. The superior opening of the larynx is made side-to-side and the epiglottis separated at the level of the superior edge of the thyroid cartilage. The ends of the section are joined together with the superior parts of the section created during the laryngeal approach. Then progressive craniocaudal detachment of the internal perichondrium is performed backwards until the endolaryngeal sections are reached and downwards to the insertion of the cord ligaments. The inferior opening of the larynx is made by a horizontal section of the cricothyroid membrane at the level of the superior edge of the cricoid cartilage. Section of the thyroid cartilage is therefore performed in a trapezoidal shape. This section involves the inferior part of the protruding corner of the thyroid cartilage. After joining the ends of the cricothyroid section with the inferior extremities of the endolaryngeal sections, the surgical specimen is removed as a single unit. The method must be used only after accurate clinical evaluation. It is mostly recommended in subjects with cord-commissure carcinomas previously treated with radiotherapy. The results obtained were extremely satisfactory both as regards survival and functional results. In all, 27/28 patients (96.4%) were free from disease. The quality of voice was satisfactory but hoarse in 30% and breathy in 70% of the patients.

Adult↗
PubMed1999

Long-term visual results of bifocal intraocular lens implantation.

PURPOSE: To evaluate the long-term visual results and variability in contrast sensitivity in patients with heparin-surface-modified (HSM) diffractive bifocal intraocular lenses (IOLs). SETTING: Institute of Ophthalmology, University of Catania, Italy. METHODS: In this prospective study, visual acuity (distance and near) and contrast sensitivity were measured in 35 patients who had phacoemulsification with bifocal diffractive IOL (model 811E, Pharmacia) implantation. Patient satisfaction was also evaluated using a questionnaire. Mean follow-up was 20 months (range 18 to 24 months). RESULTS: At the last examination, mean distance visual acuity was 0.79 +/- 0.2 (SD) without correction and 1.0 +/- 0.15 with best correction. Mean uncorrected near visual acuity was J1.6 +/- J0.77 and with best distance correction, J1.19 +/- J0.49. No statistically significant changes in visual acuity were evident at the last follow-up (Student t test). No changes were found in contrast sensitivity reduction over time, nor were late postoperative complications noted. Overall patient satisfaction was rated as good by 94.3% of patients with best distance correction. CONCLUSIONS: The diffractive bifocal HSM IOL provided good visual performance for distance and near over time. In relation to the low rate of postoperative complications, the slight contrast sensitivity reduction was stable during follow-up.

Adult↗
PubMed1997

[Fronto-lateral laryngectomy using a combined endolaryngeal external approach].

Functional laryngectomies-whether subtotal (with significant demolition) or conservative (with limited latero-frontal and frontal demolition)-can, at times, lead to significant post operative functional sequelae. Negative outcomes method proposed calls for an internal, endolaryngeal approach along with an external approach. The internal approach makes it possible to carefully delimit the posterior extension of the laryngeal neoplasm. The external approach, on the other hand, makes it possible to remove the anterior commissure and part of one or both vocal cords in a single unit together with a smaller portion of the thyroid cartilage. In particular, the endolaryngeal approach using suspension microlaryngoscopy makes it possible to section the laryngeal structures all the way up to the internal surface of the thyroid cartilage and, anteriorly, along the midline from the incision to the lower edge of the cartilage. From above the larynx is opened by means of a transfixed section of the thyroid membrane and of the epiglottis at the upper edge of the thyroid cartilage. The ends of the section are joined with the upper ends of the section prepared using the endolaryngeal approach. Cranio-caudal dissection of the internal perichondrium of the thyroid larynx is then performed, from behind, all the way to the endolaryngeal sections and, from below, to the point where the cord ligaments are inserted. The larynx is opened from below by means of a horizontal section in the crico-thyroid membrane at the upper edge of the cricoid cartilage. The trapezoidal section of the lower part of the protruding corner of the thyroid cartilage. After having joined the edges of the crico-thyroid section with the lower edge of the endolaryngeal sections, the entire piece is then removed in a single unit. This method, for treatment of carcinoma of the anterior commissure and of the anterior portion of one or both vocal cords (T1 and T2 N0 M0), must be used after accurate clinical evaluation; it is particularly appropriate for subjects with cordo-commissure carcinoma which was previously treated with radiotherapy. The method meets the requirements of oncological radicalness, permits one to perform both the external and internal sections under visual control and maintains the endolaryngeal diameters nearly intact.

Aged↗
PubMed1990

[Correlations between vocal qualities and mental retardation].

This research is intended to verify the existence of vocal spectrographic alterations, with particular reference to the values of Fundamental Frequency, in patients with different levels of Mental Retardation. The results show the existence of a direct correspondence between the values of the Fundamental Frequency and the level of Mental Retardation: the spectrographic characteristics appear to be more altered in subjects with severe Mental Retardation. The spectrographics patterns are characterized by the presence of bi-phonation particularly at the onset time and at the end, and by a noise signal on constant frequency. The shifts of Fundamental Frequency and voice breakage are rarely detected.

Adolescent↗
PubMedDate not supplied

Visual outcome after excimer laser refractive surgery in adult patients with amblyopia.

PURPOSE: To evaluate the visual and refractive outcome in adult patients wi th refractive and anisometropic amblyopia treated with photorefractive keratectomy. METHODS: An interventional non-comparative study was performed on 50 consecutive patients with amblyopia treated with photorefractive keratectomy. Sixty-eight eyes of 18 participants with bilateral refractive amblyopia and 32 participants with unilateral anisometropic amblyopia were studied. The photorefractive keratectomy was performed with MEL 70 G-Scan excimer laser. Follow-up was 1, 3, 6, and 12 months after the treatment. The mean outcome measures were uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BCVA), refraction, and corneal transparency. RESULTS: In 64.7% of eyes, the UCVA at 12 months after the treatment was better than or equal to their preoperative BCVA. A total of 82.4% of eyes improved their BCVA one or more lines. No eye lost lines of BCVA, 17.6% remained unvaried, 50% gained one line, 20.6 % gained two lines, and 11.8% gained three lines of BCVA. The number of lines gained correlated strongly with diopters of anisometropia between eyes (p<0.01). The mean sphere changed from -5.62+/-3.37 D to -0.47+/-1 D, mean cylinder varied from -2.36+/-1.57 to -0.18+/-0.41 D, and the spherical equivalent varied from -6.82+/-3.1 to -0.45+/-1.08 D. No clinically significant haze was observed. CONCLUSIONS: Excimer laser refractive surgery appears to be a safe and efficient procedure in the treatment of ametropic and anisometropic amblyopia in adults. Adult patients with anisometropic and refractive amblyopia could benefit from the refractive treatment with significant improvement of the visual acuity.

Adult↗
PubMedDate not supplied

[An unusual case of orbital cellulitis and perforating scleromalacia].

We report the case of a diabetic patient with refractory anemia with excess blasts (RAEB) who developed bladder infection followed by orbital cellulitis and nodular skin lesions. After a short remission, the clinical aspect was complicated by corneal ulceration, scleromalacia, bulbar perforation and lens luxation.

Aged↗
PubMedDate not supplied

[The senile voice].

Involutive processes which characterize aging induce substantial morphological and functional alteration in the pneumo-phono-articulatory system and thus bring about numerous effects on vocal quality. Fundamental frequency (Fo) variation, whose values increase in males and decrease in females, are found in voice patterns. Moreover, in literature many authors have described vocal substain intensity and timbre deficit in the elderly. Vocal emission of elderly people can become so peculiar that it may be possible to identify approximately the age and the sex of the speaker by merely hearing the voice. The aim of this work was to identify specific parameters of the senile voice using spectroacoustic digital analysis. The following points were considered in this study: the psychoacoustic perceptive evaluation of vocal samples in subjects of different ages in order to identify the sex and age of the speaker; the spectroacoustic digital analysis of the same vocal samples; the morphofunctional observation of the phono-articulatory apparatus. Our results confirmed the presence of peculiar electroacoustic characteristics in the senile voice (mean pitch value variation in males and in females, vocal substain deficit, decrease in vocal intensity, senile tremolo, cycle-to-cycle alteration of Fo and mean amplitude) due to morphofunctional changes of the pneumo-phono-articulatory system. In all the subjects we observed anatomo-functional changes at the glottic level. The presence of specific vocal patterns and the quality of speech play an important role in the processes of senile voice identification.

Aged↗