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M Santin

Publications and source records attributed to M Santin.

28 records · Page 2Linked to original sources
PubMed1996

Synthesis and characterization of a new interpenetrated poly(2-hydroxyethylmethacrylate)-gelatin composite polymer.

Poly(2-hydroxyethylmethacrylate) [poly(HEMA)] is a widely used biomaterial which does not allow cell adhesion and growth on its surface, limiting its use in biomedical applications in which cell cohesion is detrimental. We have prepared a poly(HEMA)-gelatin composite hydrogel using a sequential interpenetrating polymer network technique. The properties of this material were compared with poly(HEMA) freeze-dried sponges in terms of morphology, mechanical properties and biocompatibility. Moreover, in vivo biocompatibility experiments highlighted the occurrence of cellular interactions on the surface of the poly(HEMA)-gelatin interpenetrating polymer network, which are usually absent when unmodified poly(HEMA) hydrogels are implanted in the same host organism. These tests also showed a progressive gelatin degradation from the surface to the bulk of the poly(HEMA)-gelatin specimens during short-term (7 d) implantation. Finally, in vitro tests confirmed an improved ability of this composite to scaffold for the cells.

3T3 Cells↗
PubMed1995

Steroids do not enhance the risk of developing tuberculosis or other AIDS-related diseases in HIV-infected patients treated for Pneumocystis carinii pneumonia.

OBJECTIVE: To evaluate the risk of developing tuberculosis or other AIDS-related diseases (ARD) in HIV-infected patients treated with corticosteroids as adjunctive therapy for Pneumocystis carinii pneumonia (PCP). DESIGN: Retrospective study. SETTING: Infectious Disease Service of a 1000-bed university teaching hospital in Barcelona, Spain. PATIENTS: HIV-infected patients diagnosed with PCP from 1985 to 1992. Patients were classified into two groups: steroid (group A) and non-steroid (group B) adjunctive therapy. Baseline characteristics, antibiotherapy, dose and duration of steroidal treatment were analysed. Endpoints were either the development of tuberculosis or other ARD or death. RESULTS: From the 129 patients included in this study 72 were in group A and 57 in group B. No differences between groups were observed in baseline characteristics or mean follow-up period (15 versus 14 months, respectively). The mean total dose of steroids was 420 mg (range, 160-1260 mg) methylprednisolone or its equivalent in dexamethasone, with a mean treatment duration of 12 days (range, 4-33 days). No differences were found in the occurrence of tuberculosis or other endpoints in the first 6 months of follow-up. In addition, the cumulative rate of developing tuberculosis was 7% in group A and 12% in group B at 12 months of follow-up, and 13 versus 12% at 24 months (P = 0.622, Mantel-Cox): 4 versus 4% at 12 months and 27 versus 24% at 24 months (P = 0.873) for non-tuberculosis mycobacterial infection, and 40 versus 42% at 12 months, and 88 versus 66% at 24 months (P = 0.330) for non-mycobacterial ARD. The cumulative survival rate was 79 versus 71% and 46 versus 34% at 12 and 24 months, respectively (P = 0.526). CONCLUSIONS: Our data suggest that the use of corticosteroids during PCP in HIV-infected patients at the doses and for the duration used in our patients did not enhance the risk of developing or relapsing tuberculosis or other ARD.

AIDS-Related Opportunistic Infections↗
PubMed1995

Cytomegalovirus ventriculoencephalitis in AIDS patients.

We report 4 autopsy-proven cases of cytomegalovirus ventriculoencephalitis (CMV-VE) and a further case with dramatic clinical and radiological response to ganciclovir therapy. The diagnoses were based upon clinical features, cerebrospinal fluid (CSF) examination and either brain computerized tomography (CT) or magnetic resonance imaging (MRI), and confirmed by autopsy findings in 4 cases. All patients had previously had an AIDS-defining condition. CMV retinitis was diagnosed in 3 patients, 2 of them before the onset of encephalitis. CMV viremia was present in 4 patients. Examination of CSF demonstrated elevated protein and hypoglycorachia in all cases. CSF culture was negative for CMV in 3 of 3 patients. Periventricular enhancement was detected by MRI in 2 of 3 patients, but in only 1 of 5 patients by CT. Three patients received ganciclovir and 2 patients foscarnet therapy. All 4 patients died. Pathologic examination revealed periventriculitis with ependymal necrosis and CMV intranuclear inclusion bodies all 4 patients. One showed a marked neurological improvement and radiological resolution by MRI after 4 weeks of ganciclovir therapy. We conclude that CMV-VE should be suspected in HIV-infected patients who present with altered neurological status, CMV viremia or retinitis, hypoglycorachia and ventriculitis as demonstrated by MRI. Although more effective therapy is needed, ganciclovir may be beneficial, as shown in one of our patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

Chitosan-mediated stimulation of macrophage function.

According to the modern definition of biocompatibility, a biocompatible material need not be inert but be bioactive. A benign reactivity implies that the reactivity has to be appropriate for the intended use. Chitosan, a non-acetylated or partially deacetylated chitin (a linear homopolymer of beta (1-4)-linked N-acetylglucosamine) has been proposed as a biomaterial because of its apparent satisfactory biocompatibility. The present investigation demonstrates that chitosan has an in vitro stimulatory effect on both macrophage nitric oxide (NO) production and chemotaxis. The macrophage NO secretion is attributed to the N-acetylglucosamine unit of the chitosan molecule rather than to the glucosamine residue (28 and 15 microM NO respectively). Moreover, the immune stimulatory effect of chitosan was very specific since other glycosaminoglycans, such as N-acetyl-D-mannosamine and N-acetyl-D-galactosamine, had no effects on NO production (5 and 8 respectively). In vivo experiments strengthen this hypothesis. Transmission electron microscopy analysis identifies the presence of many leucocytes in the specimens after 14 d post-implantation, showing poor healing processes (i.e. fibroblast proliferation and collagen deposition) that characterize the tissue repair at this time in our animal model.

Acetylglucosamine↗
PubMedDate not supplied

First epidemic of echovirus 16 meningitis in Cuba.

From April to September 2000, an epidemic of aseptic meningitis spread throughout Cuba, with 16,943 reported cases. Virologic studies identified echovirus 16 as the cause of this epidemic. This is the first reported isolate of echovirus 16 from patients with viral meningitis in Cuba.

Adolescent↗