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Biomedical subjects

A G Secchi

Publications and source records attributed to A G Secchi.

At least 37 records · Page 2Linked to original sources
PubMed1992

Conjunctival mast cells and the allergic late phase reaction.

An active model of ocular anaphylaxis was developed in guinea pigs to evaluate the histopathology of the early (EPR) and late (LPR) phase reaction, focusing on the role of mast cells. Five groups (n = 6) of animals were actively immunized by first injecting into each of the axillary and inguinal lymph node areas, 0.25 ml of an emulsion containing 1 mg dinitrophenyl bovine gamma-globulin (DNP-BCG) with 0.5 ml complete Freund's adjuvant. After two weeks, an intramuscular injection of 0.5 ml of an emulsion containing 1 mg DNP-BGG with 0.5 ml of incomplete adjuvant was administered. One month after the first injection, animals were sacrificed after topical ocular challenge with 10 microliters of 1 mg/ml divalent hapten, di-DNP-lysine, in one eye and phosphate buffered saline (PBS) in the fellow eye as control. Clinical reactions were graded over time and histology evaluated at the endpoint (time 0, 0.5, 3, 9, and 24 h). Results showed that all animals clearly developed both an EPR and an LPR, as either a biphasic, multiphasic or prolonged clinical response. A small percentage of mast cells were degranulated at baseline, whereas, at 0.5 h, 95% of mast cells were degranulated in the eyes treated with specific hapten and 25% in the control eyes treated with PBS. At 3 h, 84% of the mast cells were degranulated. This value rose to 89% at 9 h, and remained unchanged at 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Heterogeneity of lymphocytes from aqueous humor of patients with uveitis.

T lymphocyte subsets from inflammatory aqueous humor (n = 34) have shown one of three different patterns: group 1 = lower CD4+/CD8+ ratio in aqueous as compared to peripheral blood (0.43 +/- 0.25 vs. 1.96 +/- 0.82; n = 9); group 2 = similar CD4+/CD8+ ratio in aqueous and peripheral blood (1.76 +/- 0.60 vs. 1.60 +/- 0.62; n = 22); and group 3 = higher CD4+/CD8+ ratio in aqueous as compared to peripheral blood (7.53 +/- 0.47 vs. 2.13 +/- 0.55; n = 3). DR+ T lymphocytes were significantly higher, and natural killer cells significantly lower, in inflammatory aqueous as compared to peripheral blood.

Aqueous Humor↗
PubMed1991

Double hapten challenge in guinea pigs undergoing an ocular late-phase reaction.

Clinical and histological profiles of guinea pig conjunctiva undergoing late-phase reaction (LPR) were evaluated before and after additional antigenic challenge. Four groups of animals were passively sensitized with IgG1 antibodies, challenged with the specific hapten di-DNP-lysine, and rechallenged during LPR either with di-DNP-lysine, or with PBS, or with an aspecific antigen to characterize the reactivity of the inflamed conjunctival tissues. The course of the clinical anaphylactic responses was modified slightly only by challenge with a specific hapten during LPR. However, no significant changes in the inflammatory cell profile were observed in conjunctiva undergoing LPR after an additional challenge. This suggests the participation of mechanisms which may mediate the attenuation of the anaphylactic response in physiologic conditions of persistent antigen provocation.

Anaphylaxis↗
PubMed1991

Open noncontrolled multicenter long-term trial with ciclosporin in endogenous non-infectious uveitis.

The efficacy, tolerability and safety of low doses (5-7 mg/kg/day) of oral ciclosporin (CS) for treatment of endogenous uveitis resistant to conventional therapy were studied in an open, noncontrolled, multicenter long-term trial. CS was shown to be effective for patients with posterior or intermediate noninfectious uveitis; it limited the progression of the disease, decreased the number and severity of inflammatory relapses, and improved visual acuity while reducing signs of intraocular inflammation. Moreover, in corticodependent patients, a steroid-sparing effect was also obtained. At low doses and by means of the careful monitoring of safety parameters, the side effects (especially renal function impairment) were well controlled. Efficacy was maintained during long-term treatment.

Adult↗
PubMed1990

Topical use of cyclosporine in the treatment of vernal keratoconjunctivitis.

We treated 11 patients with vernal keratoconjunctivitis for four to nine months with topical cyclosporine as a 2% dilution in castor oil. No significant side effects occurred, except for mild and transient burning upon administration. Within the first 15 days, both symptoms and signs of the condition improved significantly, and these results were maintained throughout the entire treatment. Relapses of the disease occurred two to four months after the end of the therapy. A double-masked clinical trial of nine patients (2% cyclosporine in castor oil vs castor oil alone) confirmed the results. Treated eyes improved significantly for both signs and symptoms as compared to control eyes. Topical cyclosporine may, therefore, be considered an effective substitute for corticosteroids, with an excellent anti-inflammatory activity in patients with both corticosteroid-dependent and corticosteroid-resistant vernal keratoconjunctivitis.

Administration, Topical↗
PubMed1990

Cyclosporine-A in the treatment of serpiginous choroiditis.

Seven patients affected by bilateral inflammatory serpiginous choroiditis have been treated with Cyclosporine-A for 6-21 months. Nine out of the fourteen eyes showed a significant improvement in their visual acuity; five eyes did not change. Cyclosporine-A may, therefore, be considered effective in the treatment of this disease. Its usefulness seems to be greater when the serpiginous choroiditis is in its 'acute' stage; 'chronic' stages, however, also seem to improve under treatment. Its main indication is, in our opinion, the involvement of the macular region of the 'second' eye, when the 'first' eye is already damaged. We consider Cyclosporine-A, in these situations, to be a first choice treatment.

Choroiditis↗
PubMed1990

Correlation between conjunctival provocation test (CPT) and systemic allergometric tests in allergic conjunctivitis.

In order to assess the potential usefulness of CPT as a diagnostic tool for ocular allergy, the correlation between skin/RAST tests and CPT was determined in 144 patients affected by allergic 'hay fever' type conjunctivitis. The results showed that an agreement between skin/RAST tests and CPT occurred in 71% of the cases (130/183). Of the 29% uncorrelated cases, 23% (43/183) were positive for at least one specific antigen by skin/RAST tests but not by CPT, while 6% (10/183) were positive for at least one specific antigen by CPT, but not by skin/RAST tests. CPT dramatically increased the histamine levels in tears (p less than 0.001). These findings show that (1) systemic tests can be misleading in that they may suggest a specific sensitisation which, in fact, does not involve the conjunctiva (systemic test positive/CPT negative); (2) CPT can identify local conjunctival sensitisation in the absence of a systemic sensitisation (systemic test negative/CPT positive); (3) CPT can demonstrate that allergic 'hay fever' type conjunctivitis may be related to allergens different from those responsible for a systemic sensitisation.

Adolescent↗
PubMed1989

Retinoblastoma. Combined treatment of 21 cases. Critical review of the results.

The authors report their experience in the treatment of 21 children affected by retinoblastoma. There were 14 bilateral and seven unilateral cases of retinoblastoma; mean age at diagnosis was 16 months in males (16 patients) and 30 months in females (five patients). They were all staged according to Howarth et al. (1980) and treatment was correlated to the various stages. The treatment protocol was determined by a group of co-workers at the University of Padova. Among the 35 affected eyes, 26 were enucleated and the others were treated without surgery. One patient died of cerebral metastases and two patients are affected by a second tumor with an unfavorable prognosis for survival. Two other patients are affected by chronic liver disease, probably due to chemotherapy. The authors confirm the importance of early diagnosis and prompt and effective treatment in children affected by retinoblastoma. They also stress that recently developed genetic techniques allow diagnosis of retinoblastoma even before the symptoms appear.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

A psychosomatic approach to idiopathic recurrences of anterior uveitis.

We examined 60 patients affected by idiopathic recurrent anterior uveitis and studied the relevance of stressful life events and psychological distress in relation to relapses of the disease. The results were statistically insignificant when compared to the control groups. We found that neither life events nor psychological distress played a contributory role in this disease.

Adult↗
PubMed1983

Opto-chiasmatic arachnoiditis in the young.

14 young patients, operated upon for opto-chiasmatic arachnoiditis by craniotomy are presented. 2 main etiopathogenetic forms (and their respective clinical equivalents) of the disease could be recognized. Only 1 postoperative death occurred, in a patient with a dominant clinical picture of intracranial hypertension. Results of surgery (craniotomy and lysis of adhesions) could be distinguished as positive (functional improvement) in 5 cases, indifferent or negative in the others, with a follow-up duration of up to 23 years. The role of the diagnostic value of the pneumoencephalogram as a basis for surgical indication is discussed: it is felt that this examination, when reported as negative, is not of sufficient value to rule out the diagnosis, which must essentially rely upon clinical data.

Adolescent↗
PubMed1982

Cataracts in Uveitis.

One of the most important components in the pathogenesis of lens opacification related to uveitis appears to be lens permeability changes consisting of potassium loss, sodium and water intake and late leakage of cytoplasmic constituents. These changes may be induced by 'Lens Permeability Factors' present and active in the aqueous humor during inflammation, factors that include antigen-antibody complexes, antilens and antiuveoretinal antibodies, phospholipase A and lysophosphatidylcholine (LPC). The damage caused by at least one of these factors, LPC, may be counteracted in vitro by a monosialoganglioside, (GM1). An in vivo experiment, still in progress, suggests that GM1 has a positive effect even in cases of incipient lens opacification related to uveitis.

Animals↗
PubMed1981

Gliomas of the optic nerve and chiasm. A clinical review.

A series of 24 children with anterior optic gliomas, observed and for the most part operated upon in a neurosurgical service, is reviewed. A low incidence of unilateral nerve tumors and of associated neurofibromatosis, and a rather high frequency of precocious or pseudoprecocious puberty were noted in comparison with other series. Most tumors were low-grade growths. The results of surgical treatment reflect a good prognosis for unilateral tumors and an increasing prognostic ominousness for the posterior neoplastic development. Cerebrospinal fluid shunts and radiation treatment do have a role as adjuncts to surgical exploration and biopsy, which are generally indicated since no preoperative test seems to grant an absolute diagnosis. The opinion that chiasmal tumors should not be treated at all is not shared. When the treatment of an illness falls as far short of the ultimate, as does the therapy of neoplastic disease, then it is necessary to reconsider frequently the principles upon which it is based and the results it achieves. These results are two-fold, curative and palliative and, while our efforts are directed toward the former, we realize only too frequently that the best results will sometimes lie in palliation. The disappointment in accepting this lesser goal must not allow us to underestimate its importance or neglect the help it may give.

Adolescent↗
PubMed1980

Anterior optic gliomas with precocious or pseudoprecocious puberty.

5 patients with gliomas of the anterior optic pathways, histologically assessed or with strong diagnostic evidence, who developed precocious or pseudoprecocious puberty (2 cases) before the operation or after radiation treatment, are presented. Only 2 patients presented familial and/or personal evidence of neurofibromatosis. The production mechanism of these sexual changes is discussed.

Adolescent↗