Ultrasonic energy in liposome production: process modelling and size calculation

The use of liposomes in several fields of biotechnology, as well as in pharmaceutical and food sciences is continuously increasing. Liposomes can be used as carriers for drugs and other active molecules. Among other characteristics, one of the main features relevant to their target applications is the liposome size. The size of liposomes, which is determined during the production process, decreases due to the addition of energy. The energy is used to break the lipid bilayer into smaller pieces, then these pieces close themselves in spherical structures. In this work, the mechanisms of rupture of the lipid bilayer and the formation of spheres were modelled, accounting for how the energy, supplied by ultrasonic radiation, is stored within the layers, as the elastic energy due to the curvature and as the tension energy due to the edge, and to account for the kinetics of the bending phenomenon. An algorithm to solve the model equations was designed and the relative calculation code was written. A dedicated preparation protocol, which involves active periods during which the energy is supplied and passive periods during which the energy supply is set to zero, was defined and applied. The model predictions compare well with the experimental results, by using the energy supply rate and the time constant as fitting parameters. Working with liposomes of different sizes as the starting point of the experiments, the key parameter is the ratio between the energy supply rate and the initial surface area.

Rehabilitation of acquired brain injuries: a multicentric prospective survey

BACKGROUND

The rehabilitation of the persons with Severe Acquired Brain Injury (ABI) is an important concern to be approached with a comprehensive program aimed to improve the recovery of patients.The efficacy of an early and intensive rehabilitation program has been shown in large number of studies. Few studies focused on the prevalence of TBI and the data are often extrapolated in indirect ways.

AIM

An analysis of the demographic characteristics of the population included in the GISCAR (Gruppo Italiano per lo Studio delle Gravi Cerebrolesioni Acquisite e Riabilitazione- Italian Group for the Study of the severe ABI) database, type and conditions associated to the index event; the treatment administered during hospitalization; and the prognosis according to outcome measures.

DESIGN

The study was an observational prospective survey looking at management of ABI (both traumatic and non-traumatic).

SETTING

In hospital rehabilitation.

POPULATION

Patients consecutively admitted in each of the 52 GISCAR centres.

METHODS

Every centre included a consecutive cohort and recorded demographic data and index event characteristics.

RESULTS

In the study population were included 2626 subjects suffering of a severe ABI. The difference of length of stay (LOS) was significantly different with 67.5 days for traumatic patients compared to the 80 days of non traumatic ones. In the study population the probability of discharge at home is significantly greater for the traumatic condition (odds ratio 0,4587; CI 0.3671-0.5731). The overall benefit of the rehabilitative treatment was encountered in a net gain in all disability scores taken into account: LCF classes; DRS as well as GOS scores. At discharge the main destination for severe ABI patients was home (67.2%).

CONCLUSIONS

A large number of patients admitted in Italian rehabilitative facilities for a severe ABI suffered from a TBI, more often these subjects were young male victims of road accident. The majority of subjects during the rehabilitative hospitalization demonstrated a significant recovery.

CLINICAL REHABILITATION IMPACT

Considering the evidence of an early treatment benefit the delay ofthe rehabilitation program start is far from being satisfactory. The high frequency of the home discharge indicate a good compliance of national family network.

Crystallinity and Linear Rheological Properties of Polymers

The crystallization of a polymer melt, taking place during transformation processes, has a great impact on the process itself, mainly because it causes a large increase in the viscosity (hardening). Knowledge of the hardening kinetics is important for modeling and controlling the transformation processes. In this work, first an overview is given of the experimental and modeling work on the hardening of crystallizing polymers. Next, we present isothermal crystallization experiments using differential scanning calorimetry (DSC) and rotational rheometry to measure the dynamic viscosity. The evolution of the relative crystallinity and normalized complex viscosity are correlated by a novel technique which allows simultaneous analysis of several runs, even if they are not carried out at same temperatures; the main requirement with the traditional technique. The technique, described in detail in this paper, provides an experimental relationship between the crystallinity and the hardening, i.e. the increase in the viscosity. Moreover, by measuring the dynamic viscosity at different frequencies, surprisingly, a master curve is obtained which combines the effects of shear rate, temperature and the level of crystallinity.

Therapeutic potential of nucleic acid-based drugs in coronary hyper- proliferative vascular diseases

The thickening of the vessel wall (intimal hyperplasia) is a pathological process which often follows revascularization approaches such as transluminal angioplasty and artery bypass graft, procedures used to re-vascularize stenotic artery. Despite the significant improvements in the treatment of intimal hyperplasia obtained in the last years, the problem has not completely solved. Nucleic acid based-drugs (NABDs) represent an emergent class of molecules with potential therapeutic value for the treatment of intimal hyperplasia. NABDs of interest in the field of intimal hyperplasia are: ribozymes, DNAzymes, antisense oligonucleotides, decoy oligonucleotides, small interfering RNAs and micro interfering RNAs. These molecules can recognize, in a sequencespecific fashion, a target which, depending on the different NABDs, can be represented by a nucleic acid or a protein. Upon binding, NABDs can down-modulate the functions of the target (mRNA/proteins) and thus they are used to impair the functions of disease-causing biological molecules.In spite of the great therapeutic potential demonstrated by NABDs in many experimental model of intima hyperplasia, their practical use is hindered by the necessity to identify optimal delivery systems to the vasculature. In the first part of this review a brief description of the clinical problem related to intima hyperplasia formation after revascularization procedures is reported. In the second part, the attention is focused on the experimental evidences of NABD therapeutic potential in the prevention of intimal hyperplasia. Finally, in the third part, we will describe the strategies developed to optimize NABD delivery to the diseased vessel.

Ruthenium-106 eye plaque brachytherapy in the conservative treatment of uveal melanoma: a mono-institutional experience

BACKGROUND

Traditional treatment for uveal melanoma is the enucleation of the eye with outcomes cosmetically unacceptable and loss of useful vision. Plaque brachytherapy, compared to enucleation, had the advantage to preserve the eye with outcomes cosmetically acceptable and preservation of vision.

PATIENTS AND METHODS

From July 1990 to December 2009 one hundred forty-two (142) patients (51 males and 91 females) with small to medium uveal melanoma were treated with 106Ru plaque brachytherapy. The patients underwent a complete staging before brachytherapy with indirect ophthalmoscopy and ultrasounds. Mean tumour thickness was 3.26 mm (1.6-6 mm). The dose scheduled was 80-100 Gy to the apex with a maximum dose of 800 Gy to the sclera.

RESULTS

One hundred forty-two have been treated, nine patients had lost the follow-up and drop out; 133 patients were assessed. Mean follow-up was 7.7 years (6 months-18 years). The overall survival at 5, 10 and 15 years was 92%, 85% and 78% respectively. Cancer fee survival was 95%, 90% and 83%, respectively at 5, 10 and 15 year. Radiation-induced toxicity was represented in 47 patients with a 5 year actuarial survival rate free from complications of 54%.

CONCLUSIONS

106Ru plaque brachytherapy is a valid approach for treatment of uveal melanoma. This technique is efficacy and safe, with a low toxicity profile.

Die Beziehung der Steroid-Hormon-Rezeptoren zum axillären Lymphknotenbefall beim Mammakarzinom

In 337 patients with primary cancer of the breast, the oestrogen and progesterone receptor concentration was correlated to the metastasis of axillary lymph nodes taking into account the age of the patients and the size of the primary tumour. The frequency of axillary lymph node involvement increases significantly with size, although not quite steadily but rather stepwise within the T classification. Whereas the tumour diameter influences the receptor status only slightly, the age of the patients plays a major rôle in the oestrogen receptor concentration. In the age group up to 50 years the oestrogen receptor concentration is significantly lower than in the age group over 50 years. There is no comparable influence of age on progesterone receptor concentration. With all 337 breast cancers, no difference in axillary lymph node metastasis is found either between oestrogen receptor positive and oestrogen receptor negative cancers, or between progesterone receptor positive and progesterone receptor negative cancers. In the age group up to 50 years, if looked upon separately, the oestrogen receptor positive cancers do show significantly more often an axillary lymph node involvement, than do oestrogen receptor negative cancers. As this difference exists in the age group up to 50 years only, it is assumed that endogenous oestradiol favours the axillary spread in oestrogen receptor positive cancers. With oestrogen receptor negative cancers the axillary lymph node involvement increases from the younger to the older age group, explaining why in unselected series the oestrogen receptor negative cancers show a more unfavourable course.

Treatment of neurogenic bowel dysfunction using transanal irrigation: a multicenter Italian study

STUDY DESIGN

Thirty-six patients with unsatisfactory treatment of neurogenic bowel dysfunctions (NBD) were enrolled from Spinal Units and Rehabilitation Centers in Italy. Treatment was for 3 weeks using a newly developed integrated system with an enema continence catheter for transanal irrigation (Peristeen, Coloplast A/S Kokkedal Denmark).

OBJECTIVES

To evaluate the effects of Peristeen Anal Irrigation on NBD and patient quality of life (QoL).

SETTING

Italy.

METHODS

Lesion level, ambulatory status and hand functionality were determined in all patients. NBD symptoms and QoL were evaluated before and after treatment, using a specific questionnaire. Statistical analysis was performed using McNemar Test and Sign Test.

RESULTS

Thirty-six patients were enrolled, and 32 patients completed the study. At the end of the treatment, 28.6% of patients reduced or eliminated their use of pharmaceuticals. Twenty-four patients became less dependent on their caregiver. There was a significant increase in patients' opinion of their intestinal functionality (P=0.001), QoL score (P=0.001) and their answers regarding their degree of satisfaction (P=0.001). A successful outcome was recorded for 68% of patients with fecal incontinence, and for 63% of patients with constipation.

CONCLUSION

Peristeen Anal Irrigation is a simple therapeutic method for managing NBD and improving QoL. It should be considered as the treatment of choice for NBD, playing a role in the neurogenic bowel analogous to that of intermittent clean catheterization in bladder treatment.

Effect of hinged lamellar keratotomy on postkeratoplasty eyes

PURPOSE

To evaluate the effect of a hinged lamellar keratotomy on refraction, vision, and corneal topography of postkeratoplasty eyes with high-degree astigmatism.

DESIGN

Noncomparative, interventional case series.

PARTICIPANTS

A hinged lamellar keratotomy was performed on nine eyes of nine patients at least 9 months after penetrating keratoplasty and with high-degree astigmatism. All patients were spectacle and contact lens intolerant.

INTERVENTION

A superiorly hinged lamellar keratotomy (corneal flap), 160 microm in thickness and 9 mm in diameter, was created on all eyes included in this study. Each patient was examined 1 day, 1 month, and 3 months after surgery.

MAIN OUTCOME MEASURES

Uncorrected visual acuity, best spectacle-corrected visual acuity, refraction, computerized analysis of corneal topography.

RESULTS

At each postoperative examination time, there was a significant reduction in both average spherical equivalent (P < 0.05) and average absolute value of astigmatism (P < 0.01) over mean preoperative values. The major changes were seen as early as 1 day after surgery, but both progression and regression of the effect were documented at later postoperative examinations. In all patients best spectacle-corrected acuity was maintained or improved after the procedure. Postoperatively, four patients could be successfully corrected either with spectacles (n = 2) or with gas-permeable contact lenses (n = 2). There were no surgical flap or corneal graft complications.

CONCLUSIONS

Hinged lamellar keratotomy improves vision and refraction of postkeratoplasty eyes with high-degree astigmatism. In some cases it may be so effective as to make planned excimer laser treatment unnecessary.

The heterozygous 20210 G/A genotype prevalence in patients affected by central and branch retinal vein occlusion: a pilot study

BACKGROUND

Several inherited conditions have been associated with an increased or decreased incidence of retinal vein occlusion (RVO). The A allele in the 20210 G/A prothrombin gene has been found to be associated with systemic venous thrombosis. The aim of this study has been to verify the prevalence of this mutation in patients affected by central RVO (CRVO) or branch RVO (BRVO).

METHODS

A retrospective study was carried out on 100 consecutive patients suffering from RVO, more than 50 years old, unaffected by systemic diseases known to be associated with markedly increased RVO occurrence. We determined the frequency of this mutation by performing mutagenised amplification of exon 14 followed by restriction analysis of the amplified DNA fragment.

RESULTS

The overall frequency of prothrombin 20210A allele in RVO patients was 6.0%. All heterozygous patients had suffered from CRVO. In this study subgroup, the frequency of the 20210 G/A prothrombin heterozygosis was 12.0%. The difference in the frequency of this the genetic variant between the CRVO and BRVO groups was statistically significant. None of the conventional RVO risk factors were statistically related to the occurrence of the disease in either the CRVO or the BRVO subgroup.

CONCLUSION

The prevalence of the prothrombin 20210A mutation observed in CRVO patients is significantly higher than in the normal Italian population. Moreover, the prevalence is significantly greater in CRVO than in BRVO patients. These results raise the possibility that the prothrombin 20210A variant may be considered as a risk factor for CRVO.

Idiopathic central retinal vein occlusion in a thrombophilic patient with the heterozygous 20210 G/A prothrombin genotype

PURPOSE

To report the occurrence of monolateral central retinal vein occlusion in a patient with heterozygous 20210 G/A prothrombin genotype, known to be associated with high thrombophilic risk.

METHODS

A monolateral central retinal vein occlusion was diagnosed in a 71-year-old woman, who had suffered from a deep vein thrombosis in her left leg at the age of 36 years. Mutations of the genes involved in the coagulation process were investigated by DNA polymerase chain reaction.

RESULT

DNA analysis showed the patient to be heterozygous for the prothrombin 20210 G/A genetic variation.

CONCLUSION

The 20210 G/A prothrombin gene mutation may be associated with central retinal vein occlusion.

Intraoperative cauterization of the cornea can reduce postkeratoplasty refractive error in patients with keratoconus

OBJECTIVE

This study aimed to evaluate the effect of intraoperative corneal cauterization on the postkeratoplasty refraction of patients with keratoconus.

DESIGN

A randomized clinical trial.

PARTICIPANTS

Thirty eyes of 29 patients with keratoconus undergoing standard penetrating keratoplasty by the same surgeon were evaluated (MB).

INTERVENTION

Standard penetrating keratoplasty included the use of an 8.0-mm donor button sutured into a 7.5-mm recipient bed by means of two running 10-0 nylon sutures with 16 bites each. Before trephination of the recipient bed, superficial cauterization causing tissue shrinkage was applied to a 6-mm central area of the cornea of only 15 eyes (group A). The remaining 15 eyes (group B) did not undergo intraoperative cauterization. Before surgery, 6 months, and 13 months after surgery, a complete ophthalmologic examination was performed on each patient, including uncorrected and best-corrected visual acuity, refraction, keratometry, computerized corneal topography, as well as A-scan contact ultrasonography.

MAIN OUTCOME MEASURES

Postkeratoplasty refractive error was measured.

RESULTS

Both 6 months (sutures still in place) and 13 months (suture removal performed in all patients) after surgery, the average spherical equivalent was significantly less myopic in the patients undergoing cauterization. At 6 months, it was +1.72 diopters (D) +/- 1.13 D in group A and -3.16 D +/- 2.84 D in group B; at 13 months, it was +0.09 D 1.52 D in group A and -3.89 D +/- 3.01 D in group B. The average keratometric astigmatism also was significantly lower in group A than in group B both at 6 (2.5 D +/- 1.6 D vs. 4.1 D +/- 2.3 D) and 13 months (2.7 D +/- 1.5 D vs. 4.4 D +/- 2.4 D) after surgery.

CONCLUSION

Cauterization of the central cornea improves the postkeratoplasty refractive results of patients with keratoconus.

Changes in S-phase fraction and micronucleus frequency as prognostic factors in radiotherapy of cervical carcinoma

Twenty-five patients with cervical carcinoma were treated with combined external beam and high dose rate afterloading radiotherapy. Biopsies obtained at different time points in the course of therapy were analysed with respect to cell proliferation and cytogenetic damage. The fraction of cells with an S-phase DNA-content as well as the frequency of micronuclei were determined. These two parameters were then related to treatment outcome, in particular patient survival. Neither S-phase fraction nor the micronucleus frequency before radiotherapy were predictive of treatment outcome in this small group of patients. However, when changes in response to therapy were considered, patients whose S-phase fraction decreased and patients whose micronucleus frequency increased tended to have a better prognosis. Although statistical significance was not achieved with either criterion alone, when applied together the combination predicted patient survival quite reliably; the 5-year survival rate of those patients who showed a decrease in S-phase fraction as well as an increase in micronucleus frequency was about 90% in contrast to less than 30% for the non-responders (p < 0.03).

[Neuropsychological analysis of schizophrenia-induced attention deficits--attempt at an overview]

In this review schizophrenic attention disorders are described from a neuropsychological perspective. After a historical excursion to Wundt, James and Kraepelin, the experimental psychology attention research of the last decades is presented, with special regard to Joseph Zubin's model of attention. After describing the symptomatology and course of schizophrenic psychosis, the concept of positive and negative symptoms according to Crow and Andreasen is set out as well. In describing the cognitive disorders it is on the one hand tried to elucidate the concept of "Basisstörung", and, on the other, to deal with attention disorders as potential vulnerability markers. After setting out various models re. the origin of attention disorders in both acute and chronic psychoses, implications for diagnosis and treatment are offered for the clinical psychologist in conclusion.

[Psychoses and driving fitness--development of criteria for clinical assessment]

The legal foundations for driver fitness evaluation in psychiatric conditions are enumerated in the 1985 "Illness and road traffic" expert opinion of the advisory medical council with the Federal Ministry of Transport. In case of the endogenous psychoses, in-patient episodes will invariably give rise to a call for expert psychiatric appraisement, notwithstanding the fact that reliable and valid criteria, with the exception of a standardized driving sample, continue to be almost non-existent. Carried out between 1989 and 1991 with support from the Federal Employment Institute in the framework of an employment creation project as well as from Bundesanstalt für Strassenwesen, the present study hence had been aimed at correlation-statistical identification of as valid driving ability predictors as possible in post-acute patients with a diagnosis of schizophrenic psychosis (ICD 295.3). The patients' pre-discharge fitness for driving, for one, was assessed using a number of psychological procedures and, for the other, was examined during a 60 minute practical driving sample, involving both city and autobahn driving. Driving behaviour during the practical trial was taken down according to pertinent categories, with subsequent judgment of overall driving performance both by self-ratings and by driving instructor ratings by means of a school grades scale of 1 to 6. With reference to pertinent studies elsewhere, our test battery had consisted of procedures for testing visual perception, reaction, selective and split attention, personality structure, anxiety, and risk-taking.(ABSTRACT TRUNCATED AT 250 WORDS)