Use of Proktis-M suppositories in patients undergoing neoadjuvant radiochemotherapy for adenocarcinoma of the rectum.

AIM: Generally speaking, the negative side of radiation treatment of the pelvic district is the toxicity that may compromise the patient's quality of life and lead to temporary suspension of treatment with possible negative effects on its effectiveness. In neoadjuvant radiochemotherapy for locally advanced rectal cancer (LARC), the toxicity that is most frequently observed is proctitis, usually treated with topical corticosteroids or mesalazine. Hyaluronic acid's function is to restore the regular trophism and elasticity of the connective tissues leading to faster repair of the damage, and this could represent a viable option for the control of actinic proctitis. METHODS: Since March 2012, a neoadjuvant radiochemotherapy protocol has been active at the Pisa Universitary Hospital for patients with LARC; 23 patients have been enrolled up to the present. Treatment involves an induction chemotherapy phase according to the FOLFOXIRI + Bevacizumab regimen for 6 cycles, followed by chemotherapy (capecitabina + Bevacizumab) concomitant with radiotherapy (5040 cGy in 28 fractions). Surgery is scheduled 6-8 weeks after the end of RTCT. During the course of associated treatment (RTCT), 12/23 patients received topical therapy with hyaluronic acid (Proktis-M suppositories) for the prevention of proctitis. RESULTS: All 23 patients enrolled in the study completed the induction chemotherapy phase. In the first 11 enrolled patients who did not receive prior Proktis-M suppositories, intense rectal toxicity was observed. Proctalgia of grade G1-2 and G3-4 presented respectively in 64% and 36% of cases, with consequent interruption of treatment which, in 45% of patients, lasted longer than 10 days. In the remaining 12 patients who underwent prior treatment with Proktis-M suppositories, the percentage of rectal toxicity was lower. In those cases where it did present, onset was later and its intensity and duration lower. 25% of patients did not develop proctalgia, 33% developed proctalgia of grade G1 and 42% proctalgia of grade G2. In none of these was it found necessary to interrupt radiochemotherapy. CONCLUSION: Prior topical treatment with Proktis-M suppositories in patients undergoing preoperative RTCT for LARC, enabled us to carry out radiochemotherapy at scheduled times, so protecting the treatment's effectiveness on the down-staging of the disease and preserving the patient's quality of life.

High-yield continuous production of nicotinic acid via nitrile hydratase-amidase cascade reactions using cascade CSMRs.

High yields of nicotinic acid from 3-cyanopyridine bioconversion were obtained by exploiting the in situ nitrile hydratase-amidase enzymatic cascade system of Microbacterium imperiale CBS 498-74. Experiments were carried out in continuously stirred tank UF-membrane bioreactors (CSMRs) arranged in series. This reactor configuration enables both enzymes, involved in the cascade reaction, to work with optimized kinetics, without any purification, exploiting their differing temperature dependences. To this end, the first CSMR, optimized for the properties of the NHase, was operated (i) at low temperature (5°C), limiting inactivation of the more fragile enzyme, nitrile hydratase, (ii) with a high residence time (24 h) to overcome reaction rate limitation. The second CSMR, optimized for the properties of the AMase, was operated (i) at a higher temperature (50°C), (ii) with a lower residence time (6h), and (iii) with a lower substrate (3-cyanopyridine) concentration to control excess substrate inhibition. The appropriate choice of operational conditions enabled total conversion of 3-cyanpyridine (up to 200 mM) into nicotinic acid to be achieved at steady-state and for long periods. Higher substrate concentrations required two CSMRs optimized for the properties of the NHase arranged in series to drive the first reaction to completion.

Nitrile bioconversion by Microbacterium imperiale CBS 498-74 resting cells in batch and ultrafiltration membrane bioreactors.

The biohydration of acrylonitrile, propionitrile and benzonitrile catalysed by the NHase activity contained in resting cells of Microbacterium imperiale CBS 498-74 was operated at 5, 10 and 20 degrees C in laboratory-scale batch and membrane bioreactors. The bioreactions were conducted in buffered medium (50 mM Na(2)HPO(4)/NaH(2)PO(4), pH 7.0) in the presence of distilled water or tap-water, to simulate a possible end-pipe biotreatment process. The integral bioreactor performances were studied with a cell loading (dry cell weight; DCW) varying from 0.1 mg(DCW) per reactor to 16 mg(DCW) per reactor, in order to realize near 100% bioconversion of acrylonitrile, propionitrile and benzonitrile without consistent loss of NHase activity.

Models for enzyme superactivity in aqueous solutions of surfactants.

Theoretical models are developed here for enzymic activity in the presence of direct micellar aggregates. An approach similar to that of Bru et al. [Bru, Sánchez-Ferrer and Garcia-Carmona (1989) Biochem. J. 259, 355-361] for reverse micelles has been adopted. The system is considered to consist of three pseudo-phases: free water, bound water and surfactant tails. The substrate concentration in each pseudo-phase is related to the total substrate concentration in the reaction medium. In the absence of interactions between the enzyme and the micelles, the model predicts either monotonically increasing or monotonically decreasing trends in the calculated reaction rate as a function of surfactant concentration. With enzyme-micelle interactions included in the formulation (by introducing an equilibrium relation between the enzyme confined in the free water and in the bound water pseudo-phases, and by allowing for different catalytic behaviours for the two forms), the calculated reaction rate can exhibit a bell-shaped dependence on surfactant concentration. The effect of the partition of enzyme and substrate is described, as is that of enzyme efficiency in the various pseudo-phases.

Stability and activity of immobilized hydrolytic enzymes in two-liquid-phase systems: acid phosphatase, beta-glucosidase, and beta-fructofuranosidase entrapped in poly(2-hydroxyethyl methacrylate) matrices.

Enzyme storage stability and hydrolysis yield were measured in experiments carried out with three model hydrolytic enzymes: acid phosphatase (EC 3.1.3.2), beta-glucosidase (EC 3.2.1.4), and beta-fructofuranosidase (EC 3.2.1.26) entrapped in hydrogels of poly(2-hydroxyethyl methacrylate). Runs were performed at 30 degrees C, under intensive stirring (500 rev min-1), in 50% v/v biphasic media prepared with buffer and organic solvents, whose log P value varied from 0.68 to 8.8. Storage stability was also monitored in the pure solvents. The small average particle size (125-210 microns) and the intensive stirring eliminate hindrances of intra- and interphase mass transfer resistances. The hydrophilic matrix protects the enzymes against thermal and chemical deactivation, thus allowing good production per unit weight of biocatalyst. In biphasic media, storage stability, with the exception of acid phosphatase, was not dependent on solvent polarity. On the contrary, a significant trend was observed when the enzymes were stored in neat organic solvents.

Control of enzyme properties in supramolecular systems.

The study deals with stability and activity of enzymes in supramolecular systems. Acid phosphatase (EC 3.1.3.2) has been studied as model enzyme. The organic phase is rich in C2-C4 acetates. Didodecyldimethylammonium chloride (DD-DACl) has been mainly used as ionic surfactants. The rate of enzyme inactivation is smaller than in buffer and is less dependent on storage temperature. Specific activity of the enzyme is lowered because of a less affinity towards the substrate and of reduction of maximal velocity.

Invertase activity of Saccharomyces cerevisiae cells entrapped in poly (2-hydroxyethyl methacrylate) gels: kinetic and thermostability study in membrane reactors.

Films of poly (2-hydroxyethyl methacrylate) with entrapped yeast cells have been prepared and characterized in membrane reactors. Two concentrations, 5 and 10% w/w, of crosslinking agent ethylene dimethacrylate are used. The invertase activity is monitored between 30 and 55 degrees C in the range of sucrose concentration from 40 to 200 mM and during almost 600 h of operation. Comparison is also made with the behaviour of free cells and small size particles (less than 115 mesh) of poly-HEMA immobilized cells. The results show that the whole membrane volume is not involved in substrate permeation and a combined diffusion-reaction rate controlling mechanism holds. An unusual dependence of reaction rate on bulk pH is observed. In the range of pH from 4.0 to 6.0, invertase activity in films continuously increases while two distinctive maxima for free yeast cells (pH 4.75) and for small particles of poly-HEMA-immobilized yeast cells (pH 4.5) are observed.

[Comparative study of some cephalometric analyses. 1]. / Studio comparato di alcune analisi cefalometriche--I nota.

In this article the measurements proposed by some Authors in their cephalometric analysis will be briefly described for the facial tiptology analysis, for the maxillarys divergence analysis, for the skeletal Class analysis and for the aestetic analysis.

Hydrolytic reactions in two-phase systems. Effect of water-immiscible organic solvents on stability and activity of acid phosphatase, beta-glucosidase, and beta-fructofuranosidase.

The stability and activity of three hydrolytic enzymes, acid phosphatase (EC 3.1.3.2), beta-fructofuranosidase (EC 3.2.1.26), and beta-glucosidase (EC 3.2.1.4), were studied at 30 degrees C in two-phase systems. They were prepared with equal quantities of buffered water and a water-immiscible organic solvent. Low-molecular-weight acetates and paraffins were tested in this investigation. The kinetic constant of storage inactivation was correlated with the logarithm of solvent polarity. Enzyme stability in the presence of organic phases, whose log P value was included in 1.2-2.2, was greater than the one measured in pure buffered aqueous media. On the other hand, a dramatic enzyme denaturation took place making use of solvents at higher log P-value. Experiments carried out during the 24-h operation clarified that the reaction yield does not depend solely on solvent polarity. Acid phosphatase and beta-glucosidase, which are less resistant than beta-fructofuranosidase to temperature and shear in buffered solutions, showed especially significant enhancement of catalytic activity when hydrolysis was performed with the addition of acetates (50% v/v).

[Histo-ontogenetic study of the major salivary glands and Chievitz's organ]. / Studio isto-ontogenetico sulle ghiandole salivari maggiori e dell'organo di Cheivitz.

Salivary glands development has been studied by optical microscopy in 8 fetuses aged from 8 to 20 weeks of fetal life. From the observation of the sections obtained we can assume that submandibular gland is the first gland to be detectable, later the parotid gland and then the sublingual gland. In tight connection with the parotid gland Chievitz organ has been demonstrated. It is not known whether this organ may or may not contribute to parotid gland.

[Skeletal growth of young thalassemia major patients treated with intensive transfusion]. / Considerazioni sull'accrescimento scheletrico di giovani soggetti affetti da talassemia major trattati con trasfusioni intensive.

The AA. have carried out an investigation on skeletal maturation of children and adolescent with thalassemia major. The data collected in this investigation seem to indicate that skeletal age is quite similar to cronological age in the subjects studied. Furthermore any difference statistically significant as far as growth has been observed between males and of females in our sample.

Sexual behaviour in relation to age: a study of 205 puerperal women.

Sexual desire, frequency of coitus, frequency of orgasm, which partner took the first sexual initiative, and the level of sexual satisfaction were studied in 205 women in puerperium in relation to age in the year preceding pregnancy and during pregnancy. It seems evident that sexual desire and the frequency of coitus and orgasm diminish during pregnancy independently of age. The group of younger women (16 to 20 years old) in our study maintained a relatively higher level of sexual activity especially in comparison to older women (36 to 40 years old). The number of women who took the first sexual initiative increased considerably in pregnancy.

Enzyme immobilization by means of ultrafiltration techniques.

Unstirred, plane membrane, ultrafiltration cells have been used as enzymatic reactor units. Because of the concentration polarization phenomena which take place in the system, at steady-state the enzyme is confined (dynamically immobilized) within an extremely narrow region upstream the ultrafiltration membrane. Correspondingly its concentration attains fairly high values. Kinetic studies have been therefore performed under quite unusual experimental conditions in order to better approximate local enzyme concentration levels in immobilized enzyme systems. Studies have been also carried out on the kinetics of enzyme deactivation in the continuous presence of substrate and reaction products. Once the enzyme concentration profile is completely developed, further injection into the system of suitable amounts of an inert proteic macromolecule (albumin polymers) gives rise to the formation of a gel layer onto the ultrafiltration membrane within which the enzyme is entrapped (statically immobilized). The effect of this immobilization technique has been studied as far as the kinetics of the main reaction, the substrate mass transfer resistances and the enzyme stability are concerned. The rejective properties of such gel layers towards enzymatic molecules have been exploited in producing multilayer, multi-enzymatic reactors.

Theoretical and experimental analysis of a soluble enzyme membrane reactor.

Recently enzyme immobilization techniques have been proposed that are mainly founded on the formation of an enzyme-gel layer onto the active surface of an ultrafiltration membrane within an unstirred ultrafiltration cell. If the membrane molecular-weight cutoff is less than the enzyme molecular weight and hence such as to completely prevent enzyme permeation (once the enzyme solution has been charged into the test cell and pressure applied to the system), a time progressive increase in enzyme concentration takes place at the upstream membrane surface that can eventually lead to gelation and hence to enzyme immobilization. However, depending on the total enzyme amount fed, the maximum enzyme concentration achieved in the unsteady state could be less than the gelation level. In this situation, no immobilization occurs and the enzyme still remains in the soluble form although it is practically confined within a limited region immediately upstream the membrane and at fairly high concentrations. In this paper, the experimental conditions that allow gelling to occur are discussed together with a theoretical analysis of the soluble enzyme membrane reactor which is obtained when no gelling takes place. Such a system could be usefully employed in performing kinetic analyses at high enzyme concentration levels that are still in the soluble form.