A mathematical model for the evaluation of iron transport across the blood-cerebrospinal fluid barrier in neurodegenerative diseases.

Iron plays important roles in healthy brain but altered homeostasis and concentration have been correlated to aging and neurodegenerative diseases. Iron enters the central nervous system by crossing the brain barrier systems: the Blood- Brain Barrier separating blood and brain and the Blood-Cerebrospinal Fluid Barrier (BCSFB) between blood and CSF, which is in contact with the brain by far less selective barriers. Herein, we develop a two-compartmental model for the BCSFB, based on first-order ordinary differential equations, performing numerical simulations and sensitivity analysis. Furthermore, as input parameters of the model, experimental data from patients affected by Alzheimer's disease, frontotemporal dementia, mild cognitive impairment and matched neurological controls were used, with the aim of investigating the differences between physiological and pathological conditions in the regulation of iron passage between blood and CSF which can be possibly targeted by therapy.

Clinical outcome of latissimus dorsi tendon transfer and partial cuff repair in irreparable postero-superior rotator cuff tear.

BACKGROUND AND PURPOSE: Irreparable rotator cuff tears are a common cause of pain in adult population, requiring in many cases a surgical treatment. Possible alternatives are debridement, partial repair, muscle transfers and joint replacement. We evaluated two groups of patients with irreparable rotator cuff tear treated surgically: one group received an arthroscopic-assisted latissimus dorsi tendon transfer (LDTT), and the other an arthroscopic rotator cuff partial repair. Aim of our study was to compare clinical results and quality of life in two groups of patients with massive irreparable rotator cuff tear: one receiving an arthroscopic LDTT and the other receiving an arthroscopic rotator cuff partial repair. METHODS: Forty patients were assigned to two groups: 20 patients to group TT treated with LDTT and 20 patients to group PR treated with a partial repair. The average follow-up duration was 2.8 years (1-5, SD 3). Pre- and postoperative modified UCLA shoulder score, ROM, measurement of the strength and the rotator cuff quality of life (RC-QOL) were used to asses the outcome. RESULTS: LDTT showed significative improvements when compared to partial repair in UCLA score results, strength and RC-QOL questionnaire. No differences were found between the groups in pain relief. CONCLUSION: Both techniques are effective in reducing patients' symptoms. We believe that in younger, high-demanding patients with no or mild osteoarthritis, the LDTT represents a valid treatment option with better modified UCLA score improvement and strength at our follow-up.

Epidemic history of major genotypes of hepatitis C virus in Uruguay.

Worldwide, more than 170 million people are chronically infected with the hepatitis C virus (HCV) and every year die more than 350,000 people from HCV-related liver diseases. Recently, HCV was reclassified into seven major genotypes and 67 subtypes. Some subtypes as 1a, 1b and 3a, have become epidemic as a result of the new parenteral transmission routes and are responsible for most HCV infections in Western countries. HCV 1a subtype have been sub-categorized into two separate sub clades. Recent studies based on the analysis of NS5B genome region, reveal that HCV epidemics in Argentina and Brazil are characterized by multiple introductions events of subtypes 1a, 1b and 3a, followed by subsequent local dispersion. There is no data about HCV genotypes circulating in Uruguay and their evolutionary and demographic history. To this end, a total of 153 HCV NS5B gene sequences were obtained from Uruguayan patients between 2005 and 2011. 86 (56%) sequences grouped with subtype 1a, 40 (26%) with subtype 3a and 27 (18%) with subtype 1b. Furthermore, subtype 1a sequences were distributed among both clades, 1 (n=62, 72%) and 2 (n=24, 28%). Four local HCV clades were found: UY-1a(I), UY-1a(II), UY-1a(III) and UY-3a; comprising a 39% of all HCV viruses analyzed in this study. HCV epidemic in Uruguay has been driving by multiple introductions of subtypes 1a, 1b and 3a and by local dissemination of a few country-specific strains. The evolutionary and demographic history of the major Uruguayan HCV clade UY-1a(I) was reconstructed under two different molecular clock rate models and displayed an epidemic history characterized by an initial phase of rapid expansion followed by a more recent reduction of growth rate since 2000-2005. This is the first comprehensive study about the molecular epidemiology and epidemic history of HCV in Uruguay.

Use of 65Zn as a tracer for the assessment of purification in the 68Ga-DOTANOC synthesis.

In the last years (68)Ga has got into the focus of researchers and clinicians especially for radio-labeling of biomolecules; an important characteristic of this positron emitting isotope is its availability via the (68)Ge/(68)Ga generator system: the long-lived (68)Ge (t1/2=270.8 d) produces the short-lived (68)Ga (t1/2=67.63 min) which decays to stable (68)Zn. (68)Ge breakthrough compromises (68)Ga radionuclidic purity, while (68)Zn might affect the specific activity of the radiopharmaceutical. In this paper we investigated the weight of these impurities in (68)Ga-DOTANOC synthesis. (65)Zn (t1/2=244.26d; decay mode: EC 98.3%, ß(+) 1.7%) was used as a radiotracer of stable (68)Zn; samples of the purification columns, wastes and product were recovered and measured with a calibrated HPGe gamma-ray spectrometry system. The results showed that (68)Zn competes with (68)Ga in labeling DOTANOC with a (95±2)% labeling yield; they also proved the effectiveness of the STRATA X-C cationic post-processing of the generator eluate in lowering the amount of this impurity to less than 1%. Moreover this approach, along with the purification of the final product through a STRATA X cartridge, effectively removes (68)Ge breakthrough providing a (68)Ga-DOTANOC radionuclidic purity of (99.9999986±0.0000006)%, superior to 99.9% required by the Pharmacopoeia Monograph on (68)Ga Edotreotide injection.

Automation synthesis modules review.

The introduction of (68)Ga labelled tracers has changed the diagnostic approach to neuroendocrine tumours and the availability of a reliable, long-lived (68)Ge/(68)Ga generator has been at the bases of the development of (68)Ga radiopharmacy. The huge increase in clinical demand, the impact of regulatory issues and a careful radioprotection of the operators have boosted for extensive automation of the production process. The development of automated systems for (68)Ga radiochemistry, different engineering and software strategies and post-processing of the eluate were discussed along with impact of automation with regulations.

Prediction of (89)Zr production using the Monte Carlo code FLUKA.

The widely used Monte Carlo simulation code FLUKA has been utilized to prototype a solid target for the production of (89)Zr by irradiation of a metallic (89)Y target foil in a 16.5MeV proton biomedical cyclotron, through the reaction (89)Y(p, n)(89)Zr. Simulations were performed with and without an Al energy degrader. In the setup of the geometry of the target, state of the art support tools, like SimpleGeo, were used for accurate, detailed modeling. The results permitted a quick assessment of all possible radionuclidic contaminants and confirmed that the use of an energy degrader avoids production of the most important impurity, (88)Zr. The estimated value for the activity produced in one hour of irradiation at 20µA is 384 ± 42MBq; this is encouraging, indicating possible production of clinically significant amounts of activity with the relatively simple target setup adopted. Initial experimental tests gave results in excellent agreement with simulations, confirming the usefulness and accuracy of FLUKA as a tool for the design and optimization of targets for the production of PET radionuclides.

The London APP mutation (Val717Ile) associated with early shifting abilities and behavioral changes in two Italian families with early-onset Alzheimer's disease.

BACKGROUND/AIMS: Mutations in the amyloid precursor protein gene were the first to be recognized as a cause of Alzheimer's disease (AD). METHODS: We describe 2 Italian families showing the missense mutation in exon 17 of the amyloid precursor protein gene on chromosome 21 (Val717Ile), known as London mutation. RESULTS: In 1 family, this mutation was responsible for AD in 3 out of 7 siblings and it is also present in a fourth sibling who has only shown signs of executive dysfunction so far. Two subjects of the other family with AD diagnosis were carriers of the same mutation. CONCLUSION: All AD subjects showed a cognitive profile characterized by early impairment in long-term memory, shifting abilities and affective symptoms beginning in the fifth decade of life.

Experimental monitoring of ozone production in a PET cyclotron facility.

Ozone produced from radiolytic processes was investigated as a possible health hazard in the working environment at the University Hospital "S.Orsola--Malpighi" PET facility. Intense radiation fields can generate ozone, known to be the most toxic gas produced by ionizing radiation around a particle accelerator. To evaluate ozone concentration in air, two different measurement campaigns were conducted with passive diffusion detectors. Comparison of the results with the concentration limits recommended by American Conference of Governmental Industrial Hygienists (ACGIH) demonstrated that ozone poses no health hazard to workers around a biomedical cyclotron.

Advances in preclinical therapeutics development using small animal imaging and molecular analyses: the gastrointestinal stromal tumors model.

The large use of target therapies in the treatment of gastrointestinal stromal tumors (GISTs) highlighted the urgency to integrate new molecular imaging technologies, to develop new criteria for tumor response evaluation and to reach a more comprehensive definition of the molecular target. These aspects, which come from clinical experiences, are not considered enough in preclinical research studies which aim to evaluate the efficacy of new drugs or new combination of drugs with molecular target. We developed a xenograft animal model GIST882 using nude mice. We evaluated both the molecular and functional characterization of the tumor mass. The mutational analysis of KIT receptor of the GIST882 cell lines and tumor mass showed a mutation on exon 13 that was still present after in vivo cell growth. The glucose metabolism and cell proliferation was evaluated with a small animal PET using both FDG and FLT. The experimental development of new therapies for GIST treatment requires sophisticated animal models in order to represent the tumor molecular heterogeneity already demonstrated in the clinical setting and in order to evaluate the efficacy of the treatment also considering the inhibition of tumor metabolism, and not only considering the change in size of tumors. This approach of cancer research on GISTs is crucial and essential for innovative perspectives that could cross over to other types of cancer.

Experimental results and related clinical implications of PET detection of epidermal growth factor receptor (EGFr) in cancer.

The epidermal growth factor receptor (EGFr) is one of the most studied molecules as a target for cancer therapy. Over these last few years, several studies attempting to identify predictive biomarkers of treatment response, such as the receptor status or other molecules related to the downstream signalling pathway, have been conducted. However, from a clinical point of view, the information obtained from ex vivo analyses still has various limitations that may be overcome by the combination with molecular imaging technologies which may provide a noninvasive, global, in vivo evaluation of the molecular tumour background. The aim of this review is to report the preclinical results of all positron emission tomography (PET) tracers synthesized until now for in vivo detection of EGFr in cancer. Two classes of PET compounds have been developed: labelled small molecules such as tyrosine kinase inhibitors and labelled monoclonal antibodies. The in vitro and in vivo results of these PET tracers are very different depending on the chemical properties, positron emission radionuclide, or animal models. As a consequence, various critical questions are still open, and the implications of a translation in the clinical setting for EGFr imaging in cancer patients is discussed.

Molecular imaging and targeted therapies in oncology: new concepts in treatment response assessment. a collection of cases.

The widespread use of several new non-cytotoxic drugs and the significant improvements in functional imaging highlights a number of difficulties in monitoring, interpreting and predicting treatment response in clinical practice. Certain guidelines for disease assessment after therapy are already available: the traditional Response Evaluation Criteria in Solid Tumours guidelines based on tumour size variations using conventional imaging technologies, the recent combined method developed by Choi and colleagues in gastrointestinal stromal tumour treated with tyrosine kinase inhibitors based on tumour density variations using computed tomography (CT), and the European Organization for Research and Treatment of Cancer criteria based on tumour glucose metabolism variations using fluorodeoxyglucose (FDG) positron emission tomography (PET). At the moment combined PET/CT response criteria are still not available. A number of new PET compounds other than FDG are also currently being developed to visualize specific cellular and molecular tumour pathways but their role in assessment and prediction of cancer treatment response has not yet been thoroughly investigated in a large series. However, in clinical practice many oncologists treat cancer patients with targeted therapies or chemotherapy and evaluate the response using conventional or functional imaging without appropriate and standardized guidelines. The aim of this study was to present a selection of clinical cases that illustrate the usefulness of new PET tracers and efficacy evaluation of new drugs. In the era of molecular imaging and molecular therapies, these cases highlight the urgency to develop new criteria for treatment assessment and the exigency of correctly interpreting the biological information obtained from new technologies, and introduce new concepts that require further investigation in clinical trials.

Radiolabelling, quality control and radiochemical purity assessment of the Octreotide analogue 68Ga DOTA NOC.

Somatostatin receptors 1-5 are over expressed in neuroendocrine tumours (NETs). 68Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-Nal3-Octreotide (DOTA NOC), a recent synthesized somatostatin analogue, shows high affinity for those receptors. Herein, modifications of a commercial module for the labelling of DOTA NOC with 68Ga, as well as the assessment of time course of the radiochemical purity variation are described. The evaluation of radiochemical stability was done by two different chromatographic methods: reversed-phase radio HPLC and fast TLC analysis. Labelled compound has been found radiochemically stable within 3h from the end of labelling (EOL) and radiochemical purity was always higher than 99%. After 73 labelling sessions the system showed great reproducibility and high radiochemical yield.

Conventional and novel PET tracers for imaging in oncology in the era of molecular therapy.

In the last ten years, the development of several novel targeted drugs and the refinement of state of the art technologies such as the genomics and proteomics and their introduction to clinical practice have revolutionized the management of patients affected by cancer. However, everyday practice points out several clinical questions: the difficulty of response assessment to new drugs especially using standard RECIST criteria that do not provide information on biological, vascular or metabolic variations; the inadequate selection of patients who are likely to benefit from a targeted therapy excluding those with breast cancer and gastrointestinal stromal tumours; the need to know the global biological background of diseases especially in metastatic setting using repeatable non-invasive procedures. Molecular imaging could provide information on in vivo distribution of biological markers in response to targeted therapy and could improve the selection of patients before therapies. The aim of this review is to analyze the current role of conventional and innovative positron emission tomography (PET) radiotracers in clinical practice and to explore the promising perspectives of molecular imaging in cancer research.

Mutational analysis of the inhibin alpha gene in preeclamptic women.

BACKGROUND: Preeclampsia (PE) is a disorder that occurs in at least 5% of pregnancies and affects both the mother and the unborn baby. A dramatic increase of maternal serum inhibin A concentration in the second and third trimester of pregnancy is a common feature of PE and inhibin A measurement may add significant prognostic information for predicting PE in pregnant women. DESIGN: We evaluated the presence and prevalence of gene polymorphisms for inhibin alpha subunit (INHalpha) in patients affected by PE (no.=50; study group), and in the general population (control group composed of 103 women and 42 men). METHODS: DNA extraction, single strand conformation polymorphism analysis, DNA sequencing, restriction fragment length polymorphism analysis, and Fisher's exact test were used. RESULTS: A 769G-->A transition was found in INHalpha1, but not in INHalpha2 or INHalpha3 fragment. This variant was found in 10/145 normal controls (7,6%), and in 1/50 preeclamptic patients (2%), without significant difference between the two groups (p=0.29). CONCLUSIONS: The prevalence of INHalpha gene variants is not increased in PE. Due to its frequency, the 769G-->A transition may be considered a polymorphism present in the general Italian population.

A meal stimulation test in the diagnosis of pancreatic endocrine tumors in multiple endocrine neoplasia type 1.

BACKGROUND: The diagnostic value of the determination of the serum pancreatic polypeptide (PP) and gastrin concentrations after a standard meal for early diagnosis of patients with multiple endocrine neoplasia type 1 (MEN 1) is controversial. The aim of this study was to clarify this issue. Thirteen patients with MEN 1, seven healthy family members, and eight healthy controls were studied. Plasma PP and serum gastrin were measured before and after the ingestion of a standardized meal. The meal caused a statistically significant (p < 0.05) increase of both PP and gastrin in all three groups studied. Concerning PP, no statistically significant difference was observed between patients and controls. In family members, the values were significantly (p < 0.05) lower than in the other two groups. On the whole, no significant differences in gastrin levels were noted between patients and controls; in family members, the values were significantly (p < 0.05) lower than in patients. All patients who had abnormally high postprandial values of PP and gastrin also had abnormally high basal values of these two peptides. The determination of serum PP and gastrin levels after a meal stimulation test in patients with MEN 1 adds no information about the presence of pancreatic endocrine tumors over that provided by basal values of the two peptides.

Opioid peptides attenuate blood pressure increase in acute respiratory failure.

Plasma opioid peptides, norepinephrine, atrial natriuretic factor (ANF) and blood pressure (BP) were assessed in 24 chronic obstructive pulmonary disease patients with acute respiratory failure. Hypoxemic-hypercapnic patients had high BP, beta-endorphin, Met-enkephalin and dynorphin B, whereas hypoxemic-normocapnic and hypoxemic-hypocapnic patients showed normal BP, high beta-endorphin, and normal Met-enkephalin and dynorphin B. Norepinephrine and ANF were high in all patients, particularly in hypoxemic-hypercapnic patients. Infusion with the opioid antagonist naloxone hydrochloride significantly increased systolic blood pressure (SBP) in hypoxemic-hypercapnic (182.0 +/- 3.2 versus 205.1 +/- 3.0 mmHg; P < 0.01), hypoxemic-normocapnic (149.3 +/- 1.8 versus 169.1 +/- 2.2 mmHg; P < 0.01) and hypoxemic-hypocapnic (147.3 +/- 1.3 versus 166.8 +/- 2.2 mmHg; P < 0.01) patients, norepinephrine in hypoxemic-hypercapnic patients (3583.2 +/- 371.8 versus 5371.3 +/- 260.0 fmol/ml; P < 0.01), and reduced ANF in hypoxemic-normocapnic (18.3 +/- 0.8 versus 11.9 +/- 1.0 fmol/ml; P < 0.05) and hypoxemic-hypocapnic (18.1 +/- 1.2 versus 12.1 +/- 2.1 fmol/ml; P < 0.05) patients. These results indicate that the endogenous opioid system attenuates SBP responses in acute respiratory failure by affecting norepinephrine or ANF release.

Luteinzing hormone activity in menotropins optimizes folliculogenesis and treatment in controlled ovarian stimulation.

Although the role that LH plays in folliculogenesis is still controversial, recent evidence points toward facilitatory actions of LH activity in ovulation induction. Thus, we compared the response to either highly purified FSH (75 IU FSH/ampoule; group A, 25 subjects) or human menopausal gonadotropin (75 IU FSH and 75 IU LH/ampoule; group B, 25 subjects) in normoovulatory GnRH agonist-suppressed women, candidates for intrauterine insemination. A fixed regimen of 2 daily ampoules of highly purified FSH or human menopausal gonadotropin was administered in the initial 14 days of treatment; menotropin dose adjustments were allowed thereafter. Treatment was monitored with daily blood samples for the measurement of LH, FSH, 17beta-estradiol (E(2)), progesterone, testosterone, hCG, inhibin A, and inhibin B, and transvaginal pelvic ultrasound was performed at 2-day intervals. Although preovulatory E(2) levels were similar, both the duration of treatment (16.1 +/- 0.8 vs. 12.6 +/- 0.5 days; P< 0.005) and the per cycle menotropin dose (33.6 +/- 2.4 vs. 23.6 +/- 1.1 ampoules; P < 0.005) were lower in group B. In the initial 14 treatment days the area under the curve of FSH, progesterone, testosterone, inhibin A, and inhibin B did not differ between the 2 groups, whereas LH, hCG, and E(2) areas under the curve were higher in group B. The occurrence of small follicles (<10 mm) and the inhibin B/A ratio in the late follicular phase were significantly reduced in group B. A nonsignificant trend toward a higher multiple gestation rate was present in group A (60% vs. 17%). We conclude that ovulation induction with LH activity-containing menotropins is associated with 1) shorter treatment duration, 2) lower menotropin consumption, and 3) reduced development of small ovarian follicles. These features can be exploited to develop regimens that optimize treatment outcome, lower costs, and reduce occurrence of complications such as multiple gestation and ovarian hyperstimulation.