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Biomedical subjects

A Lambiase

Publications and source records attributed to A Lambiase.

At least 19 recordsLinked to original sources

Vernal keratoconjunctivitis revisited: a case series of 195 patients with long-term followup.

OBJECTIVE: This study aimed at revisiting vernal keratoconjunctivitis (VKC) on the basis of anamnestic, clinical, immunologic, histopathologic, and followup data of 195 patients. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: One hundred and ninety-five patients with VKC. METHODS: Clinical evaluation and outcome in 151 of 195 patients with a median followup of 47 months. Evaluation was by telephone survey in 69 patients. MAIN OUTCOME MEASURES: (1) Demographic, clinical, and immunologic features of VKC and their influence on the course of the disease; (2) conjunctival and corneal complications and efficacy of treatment observed during the followup period. RESULTS: VKC is a chronic disease. More than 60% of patients had repeated recurrences all year round. Males had an earlier presentation of symptoms than females and the male/female ratio decreased with age. Major (greater than 80%) and minor (up to 80%) diagnostic criteria were defined for clinical signs and symptoms of the disease. Negative skin test or radioallergosorbent test was present in approximately 50% of patients, whereas eosinophil infiltration was a constant histopathologic finding. A marked conjunctival sensitivity to nonspecific stimuli was noted in more than one third of patients. In 6% of cases, a reduction of visual acuity resulted from corneal scarring, and in 2% of patients, steroid-induced glaucoma was observed. The large size of giant papillae indicates poor prognosis for the persistence of the disease and its evolution into a chronic, perennial condition. CONCLUSIONS: VKC is a chronic eosinophilic disease of the ocular surface involving IgE, non IgE-mediated mechanisms, and age-sex-related influences. Although the disease has a good prognosis, severe visual impairments may result from long-standing inflammation.

Adolescent↗

Topical treatment with nerve growth factor for neurotrophic keratitis.

OBJECTIVE: To evaluate the efficacy of nerve growth factor (NGF) in patients with neurotrophic keratitis. DESIGN: Prospective, noncomparative, interventional case series. PARTICIPANTS: Forty-five eyes of 43 consecutive patients with moderate (stage 2, n = 17) to severe (stage 3, n = 28) neurotrophic keratitis unresponsive to other nonsurgical therapies. METHODS: After a 10-day washout with preservative-free artificial tears, 45 eyes with neurotrophic keratitis received murine NGF (200 microg/ml) every 2 hours for 2 days followed by one drop six times daily until the ulcer healed. A maintenance dose of one drop NGF (100 microg/ml) was administered four times daily for the 2 weeks subsequent to ulcer healing. MAIN OUTCOME MEASURES: Size and depth of the ulcer or the epithelial defect, corneal sensitivity, best corrected visual acuity, side effects, and relapse of the disease in the follow-up period. RESULTS: All patients had a complete resolution of the persistent epithelial defect (with or without an ulcer) after 12 days to 6 weeks of treatment with NGF. Patients affected by both stages of the disease demonstrated both improved corneal sensitivity and visual acuity (P<0.001). No significant differences were observed in the time to complete corneal healing between stage 2 and stage 3 patients. Hyperemia and ocular and periocular pain were side effects reported during the first days of treatment. No relapse of the disease was observed during the follow-up period, with the exception of three patients with trigeminal nerve resection, who required a single retreatment. CONCLUSIONS: Nerve growth factor eye drops improved corneal sensitivity and promoted corneal epithelial healing in both moderate and severe neurotrophic keratitis. Although performed in an uncontrolled and nonrandomized series of patients, this therapy shows promise for the restoration of ocular surface integrity and visual function in neurotrophic corneal disease.

Administration, Topical↗

Transplantation potential of peripheral whole blood primed by VACOP-B chemotherapy plus filgrastim (r-metHuG-CSF) in patients with aggressive non-Hodgkin's lumphoma.

Large volumes of peripheral blood need to be processed to obtain sufficient stem cells for hematopoietic rescue after myeloablation, and more than one leukapheresis is necessary in most patients. We conceived the feasibility of harvesting sufficient numbers of hematopoietic cells from the whole blood, obtainable by venaepunctures, of patients treated with a standard dose chemotherapy regimen for high-grade non-Hodgkin's lymphoma. We evaluated the kinetics of mobilization, amount and quality of hematopoietic cells released into circulation during VACOB-B chemotherapy (which consists of a 12-week program), and G-CSF in 6 patients with aggressive non-Hodgkin's lymphoma. The median number of granulocyte-macrophage colony-forming cells (GM-CFC) x 10(3)/ml of blood (range), were 1.9 (0.3-8), and 1.16 (0.2-3.2) after the 7th and 11th weekly dose of drugs, respectively, showing an increase of 19- and 12-fold over patients' prechemotherapy values and of 53- and 33-fold over normal controls (p < 0.001). The median number of CD34+ cells x 10(3)/ml of blood (range), at the 7th and 11th cycle, was 135 (53.7-240.9) and 79.8 (69-173.5), respectively, showing an increase of 10- and 13-fold over patients prechemotherapy values (p < or = 0.04) and of 300- and 179-fold over normal controls (p < or = 0.001). Long-term culture initiating cells (LTC-IC) were released into circulation together with hematopoietic progenitors. We estimated that 1 liter of peripheral blood could yield on average 1.8 x 10(6)/kg CD34+ cells and 2 x 10(4)/kg GM-CFC with LTC-IC frequency comparable to a bone marrow harvest. These figures may be considered sufficient for hematopoietic rescue after myeloablation or hematopoietic support after high-dose chemotherapy.

Adult↗

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↗

Effects of oleoresin capsicum pepper spray on human corneal morphology and sensitivity.

PURPOSE: To examine the potential harmful effects on corneal structure, innervation, and sensitivity of a spray containing the neurotoxin capsaicin (oleoresin capsicum, OC). METHODS: Ten police officers who volunteered for the study were exposed to OC. Clinical signs were assessed. Corneal sensitivity was measured using a Cochet-Bonnet or a noncontact esthesiometer that provides separate measurements of mechanical, chemical, and thermal sensitivity. Tear fluid nerve growth factor (NGF) was measured. Corneal cell layers and subbasal nerves were examined by in vivo confocal microscopy. The subjects were examined before application and 30 minutes, 1 day, 1 week, and 1 month after OC exposure. RESULTS: OC spray produced occasional areas of focal epithelial cell damage that healed within 1 day. Each eye showed conjunctival hyperemia and in two subjects, mild chemosis. All except one eye had unchanged best corrected visual acuity (BCVA). A transient decrease (day 1) of mechanical sensitivity was observed with the Cochet-Bonnet esthesiometer. With the gas esthesiometer, mechanical sensitivity remained below normal values for 7 days. Chemical sensitivity to CO2 was high for as much as 1 day and decreased below normal 1 week later, whereas sensitivity to cold was unaffected. Two subjects had measurable tear NGF that increased after exposure. Basal epithelial cell morphology suggested temporary corneal epithelial swelling, whereas keratocytes, endothelial cells, and subbasal nerves remained unchanged. CONCLUSIONS: Although OC causes immediate changes in mechanical and chemical sensitivity that may persist for a week, a single exposure to OC appears harmless to corneal tissues. The changes are possibly associated with damage of corneal nerve terminals of mainly unmyelinated polymodal nociceptor fibers.

Adult↗

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↗

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↗

Altered nerve growth factor level in the optic nerve of patients affected by multiple sclerosis.

In this study we measured with a highly sensitive two-site immunoenzymatic assay the levels of nerve growth factor (NGF) in human optic nerve affected by multiple sclerosis (MS). The result of this study showed an elevated increase of NGF in the MS optic nerves, as compared to the level of NGF found in the optic nerves non-affected by this demyelinating disorder. Moreover, the results showed that the optic nerves also expressed trkA NGF receptor and NGFmRNA, most likely by oligodendrocytes, implying that NGF is locally produced and suggesting that the presence of NGF might be regulated by an autocrine mechanism. These and other ongoing studies on animal models indicate that altered NGF levels are among one of the early symptoms of these demyelinating diseases. The physiopathological role of NGF in the optic nerve during demyelinating disorders remains however to be defined.

Aged↗

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↗

Immunophenotypic profile of peripheral blood eosinophils in acute graft-vs.-host disease.

We used a flow cytometry technique, the "FOG" method (formaldehyde and octylglucopyranoside), to investigate the expression of activation antigens, i.e., CD4, CD23, CD25, HLA-DR, and the EG2 epitope of eosinophilic cationic protein, on peripheral blood eosinophils (PBEs) in leukemic patients who had developed acute graft-vs.-host disease (aGVHD) with eosinophilia after allogeneic bone marrow transplantation (alloBMT) or leukocyte buffy coat infusion. A comparative analysis was performed in transplanted patients not affected by aGVHD and in other conditions commonly associated with peripheral eosinophilia, i.e., interleukin (IL)-2 immunotherapy and allergy. CD25, recognizing the p55 subunit of IL-2 receptor, was detected in all patients with aGVHD except two who, at the onset of eosinophilia, were already receiving methylprednisolone intravenously. The specificity of our findings is confirmed by the absence of reactivity with anti-CD25 mAb in PBEs from transplanted patients not affected by aGVHD. Interestingly, the expression of CD25 progressively declined after steroid therapy. CD25 was also expressed after rhIL-2 administration, probably reflecting analogous mechanisms of eosinophil activation. No aGVHD or rhIL-2-treated patient showed reactivity with anti-CD4, CD23, or HLA-DR. CD25 and CD23 antigens were detected in 29% and 36% of allergic patients only. The accessibility of the EG2 epitope was significantly enhanced in all study groups compared with controls. In vitro activation of normal eosinophils with phorbol 12-myristate 13-acetate upregulated CD9 and EG2 expression but failed to induce the CD25 antigen, suggesting that selective activating stimuli may be required. The functional significance of in vivo CD25 expression and the role of activated PBEs in the development of cellular and cytokine-mediated tissue destructive processes in aGVHD remain to be clarified.

Adolescent↗

Expression of nerve growth factor receptors on the ocular surface in healthy subjects and during manifestation of inflammatory diseases.

PURPOSE: Recent studies have suggested the involvement of nerve growth factor (NGF) in the conjunctival inflammatory process and in corneal epithelium proliferation and differentiation. To verify the hypothesis that NGF could locally modulate the inflammatory and reparative processes, the authors evaluated the expression of NGF high-affinity receptor on the ocular surface in normal and pathologic conditions. METHODS: Ten conjunctival biopsies (obtained from three healthy subjects, five patients affected by vernal keratoconjunctivitis [VKC], and two patients with cicatricial pemphigoid [CP]) and five corneal specimens obtained from the Eye Bank of Veneto (Italy) were evaluated. All specimens were histologically stained, and immunohistochemistry was performed to identify the NGF high-affinity receptor (TrkA). RESULTS: All tissues expressed immunoreactivity for NGF receptors. In conjunctival specimens of healthy subjects, basal epithelial cells strongly expressed immunoreactivity and, in the stroma, rare cells were immunopositive for TrkA. No significant difference in immunoreactivity was observed in the conjunctival epithelium between healthy subjects and patients with inflammatory conjunctival diseases, whereas there were more immunopositive cells observed in the conjunctival stroma of VKC and CP patients than in the controls. The immunoreactivity in the cornea was confined to basal epithelial cells and endothelium. CONCLUSIONS: The NGF receptor is present on the human ocular surface. The authors' data support the possibility that NGF modulates ocular inflammation and corneal epithelial proliferation and differentiation through its receptors.

Adolescent↗

Nerve growth factor (NGF) reduces and NGF antibody exacerbates retinal damage induced in rabbit by experimental ocular hypertension.

BACKGROUND: It has been shown that intravitreal injection of NGF inhibits ganglion cell degeneration after optic nerve transection and ischemic injury. The aim of our study was to investigate the presence of NGF in aqueous humor and its involvement in retinal damage during ocular hypertension. METHODS: We used an experimental model of ocular hypertension in rabbit. Before treatment and 4, 10 and 15 days after induction of hypertension, we evaluated histological retinal damage and NGF levels in aqueous humor using an immunoenzymatic assay. Polyclonal anti-NGF antibodies were injected intravitreally into one eye of each rabbit (n = 6), and the animals were killed after 4 days of hypertension. Another group of rabbits (n = 12) was injected retro-ocularly with NGF and killed after 10 or 15 days of treatment for histologic evaluation of the retina. RESULTS: Our data show that experimental ocular hypertension in adult rabbits induces retinal damage and enhances local NGF levels. The highest NGF value was found after 4 days of intraocular hypertension: high levels persisted, though to a lesser extent, for up to 15 days. Histological examination revealed that the number of retinal ganglion cells (RGC) remained unchanged during the first 4 days but decreased at 10 days. These studies also showed that retro-ocular administration of NGF reduced RGC loss, whereas intraocular injection of NGF antibodies, which inhibited the endogenous NGF, exacerbated the retinal insult. CONCLUSION: These findings demonstrate a protective effect of NGF on RGC damaged by ocular hypertension and prompt further investigations to evaluate a possible therapeutic use of NGF to retard RGC death in humans.

Animals↗

Human CD4+ T cell clones produce and release nerve growth factor and express high-affinity nerve growth factor receptors.

BACKGROUND: Increasing evidence shows that nerve growth factor (NGF) plays a role in the complex and fascinating linkage between the nervous and the immune systems due to its ability to modulate functions of several inflammatory cells. OBJECTIVE: To investigate NGF receptor expression and NGF production and release by human CD4+ cells clones, which have primary relevance in modulating inflammatory events through their different subsets of functional phenotypes. METHODS: The expression of NGF and a transmembrane tyrosine kinase (TrkA) was evaluated by immunohistochemistry and flow cytometry analysis in five T(H0), six T(H1), and five T(H2) cell clones derived from human circulating mononuclear blood cells. Moreover, the amount of NGF protein was assessed by measuring the NGF levels in culture supernatants of the T cell clones before stimulation and 48 hours after phytohemagglutinin (PHA) activation by use of an immunoenzymatic assay. RESULTS: Our data have shown that in unstimulated conditions, human CD4+ T cell clones express both immunoreactivity for NGF and the TrkA NGF receptor irrespective of their cytokine profile. Moreover, T(H1) and T(H2) clones, but not T(H0) clones, secrete NGF in basal conditions. PHA activation induces NGF secretion in T(H0) clones and a significant increase of NGF levels in T(H2) (p < 0.05), but not in T(H1) culture supernatants. CONCLUSIONS: Results obtained represent the first evidence of TrkA expression and NGF production and release in human CD4+ cell clones and suggest a possible functional role of NGF in modulating the immune and inflammatory network.

CD4-Positive T-Lymphocytes↗