Experimental demonstration of the immunogenicity of silicone-protein complexes

Although silicones, as a class, are nontoxic in animal and tissue studies, implanted silicone prostheses and medical devices are associated with various local and systemic host inflammatory reactions. They also have been associated with a form of autoimmune disease. To test the hypothesis that silicones may evoke an immunologically mediated inflammatory reaction, 10 guinea pigs were stimulated for 1 month with intraperitoneal injections of sterile medical-grade silicone oil admixed with homologous serum and complete Freund's adjuvant. Ten controls were stimulated with saline. Four additional animals were passively sensitized with splenic homogenates from four sensitized animals. Intradermal antigenic challenges consisted of silicone-homologous serum, pure silicone, saline-homologous serum, and purified protein derivative. Cutaneous reaction patterns were graded grossly and microscopically. Silicone-serum and purified protein derivative antigens evoked three to four times greater palpable lesions in all 10 actively and all 4 passively sensitized animals at approximately 24 h compared to controls. Biopsies showed a moderate to marked lymphocytic infiltrate. Control sites and naive animals showed only edema at the challenge sites. The data suggest that silicone-protein complexes are potentially immunogenic.     

T cell subsets in human colostrum

Lymphocytes from 10 paired colostrum and peripheral blood specimens were examined to determine if the colostral T cell population differs from the peripheral blood T cell population in subset distribution. The percentages of lymphocytes staining with OKT3, OKT4, and OKT8 murine monoclonal antibody were determined. Lymphocytes from colostrum were 74.7 +/- 2.5% OKT3+, 50.6 +/- 2.3% OKT4+, 24.0 +/- 1.7% OKT8+, whereas peripheral blood lymphocytes were 78.7 +/- 1.9% OKT3+, 48.4 +/- 1.4% OKT4+, and 29.8 +/- 1.6% OKT8+. The percentage of colostrum lymphocytes positive for OKT3 was significantly although not strikingly lower than the OKT3 percentage for blood lymphocytes (p less than 0.05). This difference was due to the lower percentage of OKT8 positive lymphocytes in colostrum compared with blood (p less than 0.01). Although the T cell subset distribution of colostrum generally appears to be similar to that in the peripheral blood, there were small differences in OKT3 and OKT8 percentages that were statistically significant suggesting the possibility of some selectivity of the colostral T cell population.     

Anthracycline-based combined chemotherapy in the mouse model.

Our research was aimed at establishing if and how selenium (Se) ion, N-acetylcysteine (NAC), sodium salt of monoketocholic acid (MKH) and superoxide-dismutase (SOD), administered in the experimental animal model, could affect the possible cytotoxicity associated with anthracycline-based combined chemotherapy with doxorubicin, vincristine and prednisolone (DVP). The following biochemical parameters were investigated: the extent of lipid peroxidation (LPx), and the activity of peroxidase (Px), catalase (CAT), glutathione-peroxidase (GSHPx), and xanthine-oxidase (XOD). A statistical increase in LPx activity was obtained by SOD, MKH, DVPSe and DVPMKH. All chemotherapeutic agents reduced Px activity in a statistically significant manner. There was no statistical significance for the results regarding the effects of the administered substances on GSHPx activity. The results for DVP, SOD, MKH, DVPSOD, DVPSe and DVPMKH showed reduced XOD activity which was statistically significant, which was lowest in the case of MKH, while NAC and Se reduced the activity of this enzyme but statistically non significant. NAC, Se, DVP, MKH and DVPMKH caused a reduction in CAT activity, while DVPSOD and DVPSe caused an increase of the latter.     

Adapting therapy with repeated short-infusions to inter individual variability between patients.

Because of the wide inter individual variability between patients and their marked differences in drug response, one of the major issues that arises is adapting the therapy in question to the particular patient. In hospital, it is possible to vary the conditions of intravenous (i.v.) drug delivery by means of short infusions repeated at certain intervals. In this study, review of this process has been presented, and a therapeutic method described. It essentially consists of two stages. The first concerns the time of the first infusion, and the course of drug elimination: from two analyses of the drug concentrations in the blood made at two different times, the pharmacokinetic parameters of the patient are determined. Stage 2 consists of repeated short infusions and the therapy is adapted to the particular patient by varying the conditions involved. Thus, either the amount of the dose based on the rate of infusion or the time interval between the repeated infusions are varied. In order to reach a general solution, master curves are built by using dimensionless numbers as co-ordinates, such as time expressed in terms of the half-life t0.5 of the drug, and the drug concentration at the peaks defined as a fraction of the first unchanged peak concentration.     

Probing insulin's secondary structure after entrapment into alginate/chitosan nanoparticles.

The aim of the present study was to probe the structural integrity of insulin after being entrapped into chitosan/alginate nanoparticles produced by ionotropic polyelectrolyte pre-gelation. By manipulating the alginate:chitosan mass ratio and the pH during nanoparticle production, desired nanoparticles with a mean size of 850 (+/-88)nm and insulin association efficiency of 81 (+/-2)% were obtained. Insulin secondary structure was assessed by Fourier transform infrared (FTIR) and circular dichroism (CD) after entrapment into nanoparticles and after release from the particles under gastrointestinal simulated conditions. FTIR second-derivative spectra and area-overlap compared to an insulin standard confirmed that no significant conformational changes of insulin occurred in terms of alpha-helix and beta-sheet content. Far-UV-CD spectra corroborated the preservation of insulin structure during the nanoparticle production procedure. The presented nanoparticulate system is a promising carrier for insulin oral delivery since it preserves insulin structure and therefore also, potentially, its bioactivity.     

Phenotypic and genotypic characterization of prolyliminopeptidase-negative Neisseria gonorrhoeae isolates in Denmark

In the study presented here 26 recent Danish clinical isolates of prolyliminopeptidase (PIP)-negative Neisseria gonorrhoeae were phenotypically and genotypically characterized to investigate whether one or more PIP-negative strains are circulating in the Danish community. The profiles of these isolates were compared with those of three isolates from a recent outbreak of PIP-negative N. gonorrhoeae infection in the UK. Twenty-five of the Danish isolates and all three UK isolates had similar antibiograms and were designated serovar IB-4. Genotypic characterization by pulsed-field gel electrophoresis, porB1b gene sequencing, and opa-typing revealed that these isolates were indistinguishable or closely related. The results indicate that at least one PIP-negative N. gonorrhoeae strain is currently circulating in the Danish community, and this strain is indistinguishable from the one that caused an outbreak in the UK.An erratum to this article can be found at     

Primary aspergillosis of the sphenoid sinus with pituitary invasion – a rare differential diagnosis of sellar lesions

Summary Aspergillosis belongs to the group of mycotic diseases of paranasal sinuses. The invasive forms, and particularly the fulminant forms, are potentially fatal. Isolated aspergillosis of the sphenoid sinus or the clivus is a difficult diagnosis, since the often misleading clinical manifestations of this rare disease develop late. These patients become apparent by neurological signs such as cavernous sinus syndrome, pseudotumor of the pituitary or the orbit. Diagnosis is often made intra-operatively or on histological examination. We report a case of invasive aspergillosis uniquely involving the sellar area revealed by clinical features suggesting a pseudotumor of the pituitary. Although such lesions are almost always seen in immune suppressed subjects, in our case, the patient was immune competent and had no past history of sinusitis. The question of whether, and when to perform limited or extensive surgery remains an issue for discussion, owing to the rarity of this disease honed by lack of experience. It depends on several factors: the kind of disease, the immunity, the subtype of invasive fungal sinusitis and the degree of tissue invasion.