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Biomedical subjects

S Bonini

Publications and source records attributed to S Bonini.

At least 55 records · Page 3Linked to original sources
PubMed2000

Do sex and hormonal status influence choroidal circulation?

AIMS: To investigate the relation between pulse amplitude (PA), pulsatile ocular blood flow (POBF), and sex and hormonal status. METHODS: Measurements of POBF and PA were obtained by ocular blood flow tonography in 76 healthy subjects: 32 males and 44 females (age range 17-77 years). Females were divided into two age groups: group 1 (premenopausal) 17-42 years, and group 2 (post-menopausal) 55 years old and over. Two groups of age matched males served as controls. RESULTS: Premenopausal females demonstrated a significantly higher rate of POBF and PA than age matched males and post-menopausal females. CONCLUSION: Sex and hormonal status were shown to influence choroidal circulation.

Adolescent↗
PubMed2000

Conjunctival fibroblasts enhance the survival and functional activity of peripheral blood eosinophils in vitro.

PURPOSE: To examine the effect of human conjunctival fibroblasts on the survival and functional activity of human peripheral blood eosinophils. METHODS: Eosinophils were purified by negative immunoselection [magnetic activated cell sorter (MACS), purity > 97%] from volunteers with mild atopia. Fibroblasts were cultured from conjunctival specimens of healthy donors. Eosinophils were cultured on confluent monolayers of conjunctival fibroblasts or in culture medium alone. Eosinophil survival was evaluated by the trypan blue exclusion test. Eosinophil adherence was assessed by counting the attached cells after washing the cultures. Eosinophil viability and adherence in coculture were also assessed in the presence of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF), anti-interleukin (IL)-3, and anti-IL-5 neutralizing antibodies. Cocultured eosinophils were activated by lipopolysaccharide (LPS) after 4 days in culture, and eosinophil peroxidase (EPO) release was determined as a marker of their activation. RESULTS: Eosinophils cocultured with conjunctival fibroblasts had a significantly increased viability of 35.9% (P = 0.004) and 12.8% (P = 0.003) on days 4 and 8, respectively. Fibroblast-conditioned medium did not enhance the survival of eosinophils. The increase in eosinophil survival in coculture was partially inhibited by anti-GM-CSF (P = 0.019), anti-IL-3 (P = 0.033), or anti-IL-5 (P = 0.011), whereas eosinophil adherence was reduced by anti-GM-CSF alone (P = 0.034). LPS activation of eosinophils cultured for 4 days with conjunctival fibroblasts induced higher EPO release than in freshly isolated eosinophils (P = 0.01). CONCLUSIONS: Human conjunctival fibroblasts induced prolonged survival and increased secretory function of human peripheral blood eosinophils. Increased survival is partially mediated by IL-3, IL-5, and GM-CSF. The coculture of conjunctival fibroblasts with eosinophils can serve as an in vitro system for the study of eosinophil behavior in the ocular surface and of cellular interactions in allergic eye diseases.

Adolescent↗
PubMed2000

Nerve growth factor promotes corneal healing: structural, biochemical, and molecular analyses of rat and human corneas.

PURPOSE: A recent clinical report demonstrated that topical nerve growth factor (NGF) treatment in patients affected by corneal neurotrophic ulcers induced epithelial and stromal healing restoring corneal integrity. Mechanisms(s) undergoing these clinical NGF actions are still unclear. The aim of this study was to investigate the role of NGF in human and rat cornea physiopathology. METHODS: Expression of high-affinity NGF receptors, NGF-mRNA, and NGF protein was evaluated in human and rat normal corneas, in human and rat corneal epithelial cell cultures, in human corneal organ culture, and in the rat cornea after an experimental model of epithelial injury, by means of immunohistochemistry, in situ hybridization reverse transcription-polymerase chain reaction, and enzyme-linked immunosorbent assay. RESULTS: The resultant data demonstrated that NGF is a constitutive molecule present and produced in normal human and rat corneas. In vitro human and rat corneal epithelial cells produce, store, and release NGF and also express high-affinity NGF receptors (TrkA). In human organ culture, epithelium, keratocytes, and endothelium have been shown to bind exogenous radiolabeled NGF, and the epithelial cells' binding was increased after epithelium injury. In vivo, after rat corneal epithelial injury, a transient increase of corneal NGF levels was observed. Inhibition of endogenous NGF activity by neutralizing anti-NGF antibodies delayed the corneal epithelial healing rate, whereas exogenous administration of NGF accelerated healing. CONCLUSIONS: Taken together, the above findings show that NGF plays an important role in corneal physiopathology and suggest that this neurotrophin may exert therapeutic action in wide-spectrum corneal diseases.

Aged↗
PubMed1999

Location and clonal analysis of stem cells and their differentiated progeny in the human ocular surface.

We have analyzed the proliferative and differentiation potential of human ocular keratinocytes. Holoclones, meroclones, and paraclones, previously identified in skin, constitute also the proliferative compartment of the ocular epithelium. Ocular holoclones have the expected properties of stem cells, while transient amplifying cells have variable proliferative potential. Corneal stem cells are segregated in the limbus, while conjunctival stem cells are uniformly distributed in bulbar and forniceal conjunctiva. Conjunctival keratinocytes and goblet cells derive from a common bipotent progenitor. Goblet cells were found in cultures of transient amplifying cells, suggesting that commitment for goblet cell differentiation can occur late in the life of a single conjunctival clone. We found that conjunctival keratinocytes with high proliferative capacity give rise to goblet cells at least twice in their life and, more importantly, at rather precise times of their life history, namely at 45-50 cell doublings and at approximately 15 cell doublings before senescence. Thus, the decision of conjunctival keratinocytes to differentiate into goblet cells appears to be dependent upon an intrinsic "cell doubling clock. " These data open new perspectives in the surgical treatment of severe defects of the anterior ocular surface with autologous cultured conjunctival epithelium.

3T3 Cells↗
PubMed1999

Management of neurotrophic keratopathy.

Neurotrophic keratopathy is a degenerative corneal disease caused by an impairment of corneal sensitivity. Lack of the sensory nerve's trophic effect is responsible for the impairment in corneal healing and for the changes on the ocular surface that lead to corneal epithelial deficit, ulcer, and perforation. The etiology and recent advances in understanding of the pathogenetic mechanisms of neurotrophic keratopathy are reviewed here. An accurate history and a clinical examination that covers the function of cranial nerves often identify the cause of the disease. Clinical features and guidelines for the differential diagnosis and treatment are presented. Specific medical and surgical treatments, selected on the basis of clinical staging of the disease, can often halt disease progression. Future developments in medical treatment, including the use of neuropeptide and growth factors, are discussed. The identification of corneal anesthesia associated with an epithelial defect allows appropriate treatment and prevention of progression to stromal lysis and perforation.

Cornea↗
PubMed1999

Topical lomefloxacin 0.3% twice daily versus tobramycin 0.3% in acute bacterial conjunctivitis: A multicenter double-blind phase III study.

AIMS/BACKGROUND: To evaluate in a double-masked comparative, prospective, randomized multicenter trial the efficacy of lomefloxacin 0.3% eye drops twice daily and of tobramycin eye drops 4 times daily in patients with acute bacterial conjunctivitis. METHODS: Ninety-nine subjects were enrolled: 50 were treated with lomefloxacin 0.3% eye drops twice daily and 49 with tobramycin 0.3% eye drops 4 times daily. In all patients, conjunctival swabbing and assessment of objective signs and of subjective symptoms were performed. RESULTS: There was no statistical difference for any individual sign or symptom or for the sum score of either key or other signs and symptoms at any of the examination days. The sum score of both key and other signs and symptoms decreased in both groups at day 3-4 as compared to baseline values (p < 0.0001). The decrease in both these scores continued significantly from day 3-4 to day 7-8 (p < 0.05) and was similar in the two treatment groups (p > 0.4). The lowest resistance rate was seen in lomefloxacin (3.5%) and in neomycin (7.0%), while tobramycin showed resistance in 10 out of 88 resistance strains (11.4%). CONCLUSION: Both lomefloxacin 0.3% twice daily and tobramycin 0.3% administered 4 times daily were well tolerated and showed a high degree of clinical and microbiological efficacy in the treatment of acute bacterial conjunctivitis. Lomefloxacin caused less resistance than other antibiotics evaluated.

Acute Disease↗
PubMed1999

Blunt chest trauma: case report.

Care of patients with blunt cardiac trauma is challenging for bedside nurses because of the potentially elusive and subtle nature of clinical findings associated with such trauma. An understanding of the forces exerted during the trauma episode will assist nurses in the assessment and search for hidden injuries. A high index of suspicion and continued cautious assessment and attention to subtle changes in the patient's physical condition are essential. Keen attention to changes in the patient's vital signs, cardiac output, ECG findings, pulses, and fluid volume status alert nurses to potential injuries associated with blunt cardiac trauma ranging from myocardial contusion to cardiac tamponade, aortic tears, and cardiac rupture. Survival of patients with blunt cardiac trauma depends on early intervention.

Accidents, Traffic↗
PubMed1998

Topical treatment with nerve growth factor for corneal neurotrophic ulcers.

BACKGROUND: Corneal neurotrophic ulcers associated with impairment of sensory innervation of the cornea may lead to loss of vision, and there is no effective treatment for these ulcers. We evaluated the effects of nerve growth factor in patients with this disorder. METHODS: Twelve patients (14 eyes) with severe neurotrophic corneal ulcers associated with corneal anesthesia were treated with topical nerve growth factor 10 times daily for two days and then 6 times daily until the ulcers healed. Treatment continued for 2 weeks after the ulcers healed, and the patients were then followed for up to 12 months. The evolution of the corneal disease during treatment and follow-up was evaluated by slit-lamp examination, photography, fluorescein-dye testing, and tests of corneal sensitivity and best corrected visual acuity. RESULTS: Corneal healing began 2 to 14 days after the initiation of treatment with nerve growth factor, and all patients had complete healing of their corneal ulcers after 10 days to 6 weeks of treatment. Corneal sensitivity improved in 13 eyes, and returned to normal in 2 of the 13 eyes. Corneal integrity and sensitivity were maintained during the follow-up period (range, 3 to 12 months). Best corrected visual acuity increased progressively during treatment and follow-up in all patients. There were no systemic or local side effects of treatment. CONCLUSIONS: In this preliminary, uncontrolled study, topically applied exogenous nerve growth factor restored corneal integrity in patients with corneal neurotrophic ulcers.

Administration, Topical↗
PubMed1998

Nerve growth factor is preformed in and activates human peripheral blood eosinophils.

BACKGROUND: Recent studies have shown that nerve growth factor (NGF) is produced by and can act on several immune-inflammatory cells. OBJECTIVES: The objective of this study was to study the effects of NGF on human peripheral blood eosinophils and assess whether these cells produce and store NGF. METHODS: Eosinophils were purified by negative immunoselection (magnetic cell sorting systems, purity 98% to 100%) from 13 subjects (9 to 26 years old) with mild blood eosinophilia, mainly of allergic origin. Eosinophils were incubated with NGF (50 to 1000 ng/mL), and supernatants were collected for measurement of eosinophil peroxidase (EPO, 20 minutes, colorimetric enzymatic assay) and IL-6 (12 hours, ELISA). Eosinophil viability was evaluated by Trypan blue test (days 2, 3, and 4). NGF content in freshly isolated eosinophils, after ultrasound disruption, was determined with a 2-site immunoenzymatic assay. The presence of mRNA for NGF was evaluated by reverse transcription PCR. RESULTS: NGF caused EPO release (highly significant at 1000 ng/mL NGF). IL-6 release from eosinophils was not higher than IL-6 spontaneously released into culture medium alone. NGF did not significantly affect the number of viable eosinophils. NGF was found in the eosinophil sonicates (1.5 to 17.8 pg/mL per 106 cells). Similarly, mRNA for NGF was detected by reverse transcription PCR in the freshly isolated eosinophils. CONCLUSIONS: NGF activates human peripheral blood eosinophils from subjects with mild eosinophilia to selectively release inflammatory mediators. Eosinophils store and produce NGF. Therefore the capability of NGF to induce a secretory response and its production and storage by circulating human eosinophils suggest a possible role for NGF in conditions associated with eosinophilia, including allergic disease.

Adolescent↗
PubMed1998

Pollen-related allergy in Europe.

The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropalynologic and allergologic studies have progressed to meet this need, and extensive international networks now provide regular pollen and hay-fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently, pollen calendars differ from one area to another; however, on the whole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Europe, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Mediterranean areas favor the production of pollen types that are rarely found in central and northern areas of the continent (e.g., the genera Parietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultural factors (e.g., importation of plants for urban parklands) and greater international travel (e.g., the expansion of the ragweed genus Ambrosia in France, northern Italy, Austria, and Hungary). Studies on allergen-carrying paucimicronic or submicronic airborne particles, which penetrate deep into the lung, are having a relevant impact on our understanding of pollinosis and its distribution throughout Europe.

Allergens↗