Electroretinography, Ocular Ultrasonography, and Phacoemulsification of Bilateral Cataracts in Two Juvenile Loggerhead Sea Turtles (Caretta caretta) of the Mediterranean Region

Bilateral cataracts were diagnosed in two rescued juvenile, immature loggerhead sea turtles (Caretta caretta), weighing 1.65 and 1.7 kg. Both animals showed vision impairment and difficulty in feeding without assistance. In fact, they did not notice the presence of the food in the tank unless it was brought close to touching the mouth. Ocular ultrasonography and electroretinography showed no lesions of the vitreal body and retinal layer, therefore, both animals were candidates for bilateral cataract surgery. Topical administration of tropicamide + phenylephrine alternating with rocuronium resulted in only minimal mydriasis. Administration of intracameral rocuronium did not improve mydriasis. Phacoemulsification using a one-handed technique was performed bilaterally with a phacoemulsification device (Sovereign, AMO (Abbott Medical Optics^®). After surgery, the systemic anti-inflammatory drug (dexamethasone 0.2 mg/kg, IM daily for one week) and antibiotics (enrofloxacin 10 mg/kg IM q 72 h, for 4 weeks; ceftazidime 20 mg/kg IM q 72 h for 3 weeks) were administered. Topical ofloxacin, flurbiprofen and tobramycin/dexamethasone were instilled TID for 4 weeks. Both turtles regained vision in both eyes. Results at a 10-month follow-up were satisfactory. This is the first report of cataracts in turtles rescued in the Mediterranean Sea and the first description of surgical treatment of cataracts in loggerhead turtles so young.

Symblepharon, Ankyloblepharon, and Salt Gland Dysfunction in a Loggerhead Sea Turtle (Caretta caretta)

Adhesions involving the bulbar and the palpebral conjunctiva (Symblepharon) may interfere with tear drainage, cause chronic conjunctivitis, and reduce ocular motility. This condition may be associated with adhesion of the edges of the upper and lower eyelids (ankyloblepharon). The present case describes bilateral symblepharon, ankyloblepharon and salt gland dysfunction in a juvenile Caretta caretta. The loggerhead presented both eyelids swollen, ulcerated, and not separable when rescued. Eye examination was not possible, but ultrasonography showed right bulbar integrity, while the left eye was smaller, with a thicker cornea that had lost its normal doubled lined structure. Surgical dissection of the fibrous adhesions between the palpebral and bulbar conjunctiva, cornea, and third eyelid was performed, and large dacryoliths were removed. The microscopic findings were consistent with chronic keratoconjunctivitis. Ultrastructurally, no virus-like particles were observed. In addition, tissue samples were negative for herpesvirus by qualitative PCR. The eyelids of both eyes and the corneal epithelium of the right eye healed; moreover, the vision was restored in the right eye. There were no recurrences after 12 months of follow-up, and the turtle was released 16 months after the end of treatments on the southern Tyrrhenian coast in the western Mediterranean Sea. To the authors’ knowledge, this is the first report of symblepharon with ankyloblepharon and salt gland dysfunction in Caretta caretta turtle. Ocular ultrasonography was helpful in the preliminary diagnostic work-up.

A pilot study on molecular diagnosis of Hapalotrema mistroides (Digenea: Spirorchiidae) infection in blood samples of live loggerhead turtles Caretta caretta

BACKGROUND

Parasites of the family Spirorchiidae cause disease and mortality in marine and freshwater turtles; two species, Hapalotrema mistroides and Neospirorchis sp., are reported in the resident population of loggerhead turtles of the Mediterranean Sea, with the first being the most widespread. In vivo diagnosis of spirorchidiasis can represent a challenge in guaranteeing prompt control and treatment of the disease and is currently limited to copromicroscopy. The aim of this study was the development of a real time PCR assay with TaqMan probe for the detection of H. mistroides infection in the blood of live loggerhead turtles, Caretta caretta, hospitalized in rehabilitation centres. Its potential use for in vivo diagnosis is explored.

RESULTS

The developed real time PCR successfully detected H. mistroides DNA from both positive controls and experimental blood samples of live loggerhead sea turtles, showing good specificity, sensitivity and good reaction efficiency. Two out of three turtles which had demonstrated positivity at copromicroscopy also tested positive to this blood assay; DNA of H. mistroides was detected within the blood of one sea turtle, which tested negative for copromicroscopy.

CONCLUSIONS

This study describes a specific and rapid molecular assay to detect H. mistroides infection from live sea turtles and highlights for the first time the presence of DNA of this species in turtle blood samples. Since this assay is able to detect low amounts of the parasitic free DNA in blood samples, its application could be helpful for in vivo diagnosis of H. mistroides infection as well as for epidemiological purposes.

Aeromonas induced polyostotic osteomyelitis in a juvenile loggerhead sea turtle Caretta caretta

Bacterial bone infections have been occasionally reported in wild sea turtles. This study reports on a sub-adult Caretta caretta affected by Aeromonas hydrophila osteomyelitis, with extensive involvement of cranial and caudal flippers. The turtle was severely debilitated, had limited flipper mobility and showed signs of pain in reaction to manipulation. Radiographs and computed tomography revealed multiple lytic bone lesions. Since an infectious polyostotic osteomyelitis was suspected, the turtle was subjected to echo-assisted fine needle aspiration to characterize the etiology of the disease. Bacterial cultures and antibiotic susceptibility testing led to the isolation of Aeromonas hydrophila responsive to amikacin and doxycycline. Therefore, the turtle was treated with these antibiotics and monitored through repeat bacterial cultures and diagnostic imaging. The turtle was released 17 mo after admission, upon resolution of clinical signs. The documentation of this case provides a treatment approach that may improve the outcome of Aeromonas-associated osteomyelitis, especially in endangered wildlife species.

Pathology and molecular analysis of Hapalotrema mistroides (Digenea: Spirorchiidae) infecting a Mediterranean loggerhead turtle Caretta caretta

Turtle blood flukes belonging to the family Spirorchiidae (Digenea) represent a major threat for sea turtle health and are considered the most important parasitic cause of turtle stranding and mortality worldwide. Despite the large diversity of spirorchiid species found globally, there are only 2 records for free-ranging Mediterranean sea turtles that date back to the late 1800s involving just Hapalotrema mistroides Monticelli, 1896. This study describes the first fatal confirmed case of spirorchiidiasis in a free-ranging Mediterranean loggerhead turtle Caretta caretta (Linnaeus) and, owing to the complexities of taxonomic identification of these parasites, provides the first molecular characterization and phylogenetic analysis of H. mistroides from the Mediterranean Sea. The loggerhead turtle showed cachexia and digestive disorders associated with severe damage to the pancreas and intestinal ganglia, caused by deposition of Hapalotrema eggs forming granulomas. Massive Hapalotrema egg emboli in several tissues and organs and encephalitis were the most probable contributions to the death of the turtle. The congruence between the phylogenetic analysis of both the ITS2 and 28S rDNA resolved the Italian and USA H. mistroides as the same species, confirming the parasite identification. The case here described clearly indicates that the blood flukes should be considered in the differential diagnosis of Mediterranean sea turtle diseases.

Guidelines for the Care and Welfare of Cephalopods in Research -A consensus based on an initiative by CephRes, FELASA and the Boyd Group

This paper is the result of an international initiative and is a first attempt to develop guidelines for the care and welfare of cephalopods (i.e. nautilus, cuttlefish, squid and octopus) following the inclusion of this Class of ∼700 known living invertebrate species in Directive 2010/63/EU. It aims to provide information for investigators, animal care committees, facility managers and animal care staff which will assist in improving both the care given to cephalopods, and the manner in which experimental procedures are carried out. Topics covered include: implications of the Directive for cephalopod research; project application requirements and the authorisation process; the application of the 3Rs principles; the need for harm-benefit assessment and severity classification. Guidelines and species-specific requirements are provided on: i. supply, capture and transport; ii. environmental characteristics and design of facilities (e.g. water quality control, lighting requirements, vibration/noise sensitivity); iii. accommodation and care (including tank design), animal handling, feeding and environmental enrichment; iv. assessment of health and welfare (e.g. monitoring biomarkers, physical and behavioural signs); v. approaches to severity assessment; vi. disease (causes, prevention and treatment); vii. scientific procedures, general anaesthesia and analgesia, methods of humane killing and confirmation of death. Sections covering risk assessment for operators and education and training requirements for carers, researchers and veterinarians are also included. Detailed aspects of care and welfare requirements for the main laboratory species currently used are summarised in Appendices. Knowledge gaps are highlighted to prompt research to enhance the evidence base for future revision of these guidelines.

Cross-species toxicogenomic analyses and phenotypic anchoring in response to groundwater low-level pollution

Background

Comparison of toxicogenomic data facilitates the identification of deregulated gene patterns and maximizes health risk prediction in human.

Results

Here, we performed phenotypic anchoring on the effects of acute exposure to low-grade polluted groundwater using mouse and zebrafish. Also, we evaluated two windows of chronic exposure in mouse, starting in utero and at the end of lactation. Bioinformatic analysis of livers microarray data showed that the number of deregulated biofunctions and pathways is higher after acute exposure, compared to the chronic one. It also revealed specific profiles of altered gene expression in all treatments, pointing to stress response/mitochondrial pathways as major players of environmental toxicity. Of note, dysfunction of steroid hormones was also predicted by bioinformatic analysis and verified in both models by traditional approaches, serum estrogens measurement and vitellogenin mRNA determination in mice and zebrafish, respectively.

Conclusions

In our report, phenotypic anchoring in two vertebrate model organisms highlights the toxicity of low-grade pollution, with varying susceptibility based on exposure window. The overlay of zebrafish and mice deregulated pathways, more than single genes, is useful in risk identification from chemicals implicated in the observed effects.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1067) contains supplementary material, which is available to authorized users.

NCOA4 transcriptional coactivator inhibits activation of DNA replication origins

NCOA4 is a transcriptional coactivator of nuclear hormone receptors that undergoes gene rearrangement in human cancer. By combining studies in Xenopus laevis egg extracts and mouse embryonic fibroblasts (MEFs), we show here that NCOA4 is a minichromosome maintenance 7 (MCM7)-interacting protein that is able to control DNA replication. Depletion-reconstitution experiments in Xenopus laevis egg extracts indicate that NCOA4 acts as an inhibitor of DNA replication origin activation by regulating CMG (CDC45/MCM2-7/GINS) helicase. NCOA4(-/-) MEFs display unscheduled origin activation and reduced interorigin distance; this results in replication stress, as shown by the presence of fork stalling, reduction of fork speed, and premature senescence. Together, our findings indicate that NCOA4 acts as a regulator of DNA replication origins that helps prevent inappropriate DNA synthesis and replication stress.

Cephalopods in neuroscience: regulations, research and the 3Rs

Cephalopods have been utilised in neuroscience research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentiation) and anatomical features facilitating physiological studies (e.g. squid giant axon and synapse). On 1 January 2013, research using any of the about 700 extant species of "live cephalopods" became regulated within the European Union by Directive 2010/63/EU on the "Protection of Animals used for Scientific Purposes", giving cephalopods the same EU legal protection as previously afforded only to vertebrates. The Directive has a number of implications, particularly for neuroscience research. These include: (1) projects will need justification, authorisation from local competent authorities, and be subject to review including a harm-benefit assessment and adherence to the 3Rs principles (Replacement, Refinement and Reduction). (2) To support project evaluation and compliance with the new EU law, guidelines specific to cephalopods will need to be developed, covering capture, transport, handling, housing, care, maintenance, health monitoring, humane anaesthesia, analgesia and euthanasia. (3) Objective criteria need to be developed to identify signs of pain, suffering, distress and lasting harm particularly in the context of their induction by an experimental procedure. Despite diversity of views existing on some of these topics, this paper reviews the above topics and describes the approaches being taken by the cephalopod research community (represented by the authorship) to produce "guidelines" and the potential contribution of neuroscience research to cephalopod welfare.

Mice anesthesia, analgesia, and care, Part II: anesthetic considerations in preclinical imaging studies

Animal experiments are necessary for a better understanding of diseases and for developing new therapeutic strategies. The mouse (Mus musculus) is currently the most popular laboratory animal in biomedical research. Mice imaging procedures are increasingly used in preclinical research because they allow in vivo monitoring and they are readily available for longitudinal and noninvasive studies as well as investigations into the evolution of diseases and the effects of new therapies. New imaging techniques and sophisticated laboratory animal imaging tools are currently producing a large body of evidence about the possible interference of anesthesia with different imaging methods that have the potential to compromise the results of in vivo studies. The purpose of this article is to review the existing literature on molecular imaging studies in mice, to describe the effects of different anesthetic protocols on their outcome, and to report our own experience with such studies.

Mice anesthesia, analgesia, and care, Part I: anesthetic considerations in preclinical research

Animal experiments are necessary for a better understanding of diseases and for developing new therapeutic strategies. The mouse (Mus musculus) is currently the most popular laboratory animal in biomedical research. Experimental procedures on animals often require anesthesia and/or analgesia to obtain adequate immobilization and to reduce stress or pain. Mice anesthesia is challenging for several reasons including the animals' size, metabolic rate, and the high risk of hypothermia and hypoglycemia. Moreover, anesthetic agents influence physiological parameters, further interfering with experimental results. Small animal imaging procedures are increasingly used in biomedical research both because the animals allow in vivo monitoring and because they are readily available for longitudinal and noninvasive studies as well as investigations into the evolution of diseases and the effects of new therapies. Anesthesia must adapt to the imaging technique, the procedure length, and the aim of the study. The purpose of this article is to review the existing literature on anesthetic protocols adopted in mice for molecular imaging studies and to report our experience.

CD133 and CD44 cell surface markers do not identify cancer stem cells in primary human gastric tumors

Emerging evidence suggests that tumors contain and are driven by a cellular component that displays stem cell properties, the so-called cancer stem cells (CSCs). CSCs have been identified in several solid human cancers; however, there are no data about CSCs in primary human gastric cancer (GC). By using CD133 and CD44 cell surface markers we investigated whether primary human GCs contain a cell subset expressing stem-like properties and whether this subpopulation has tumor-initiating properties in xenograft transplantation experiments. We examined tissues from 44 patients who underwent gastrectomy for primary GC. The tumorigenicity of the cells separated by flow cytometry using CD133 and CD44 surface markers was tested by subcutaneous or intraperitoneum injection in NOD/SCID and nude mice. GCs included in the study were intestinal in 34 cases and diffuse in 10 cases. All samples contained surface marker-positive cells: CD133(+) mean percentage 10.6% and CD133(+)/CD44(+) mean percentage 27.7%, irrespective of cancer phenotype or grade of differentiation. Purified CD133(+) and CD133(+)/CD44(+) cells, obtained in sufficient number only in 12 intestinal type GC cases, failed to reproduce cancer in two mice models. However, the unseparated cells produced glandular-like structures in 70% of the mice inoculated. In conclusion, although CD133(+) and CD133(+)/CD44(+) were detectable in human primary GCs, they neither expressed stem-like properties nor exhibited tumor-initiating properties in xenograft transplantation experiments.

A neutralizing RNA aptamer against EGFR causes selective apoptotic cell death

Nucleic acid aptamers have been developed as high-affinity ligands that may act as antagonists of disease-associated proteins. Aptamers are non immunogenic and characterised by high specificity and low toxicity thus representing a valid alternative to antibodies or soluble ligand receptor traps/decoys to target specific cancer cell surface proteins in clinical diagnosis and therapy. The epidermal growth factor receptor (EGFR) has been implicated in the development of a wide range of human cancers including breast, glioma and lung. The observation that its inhibition can interfere with the growth of such tumors has led to the design of new drugs including monoclonal antibodies and tyrosine kinase inhibitors currently used in clinic. However, some of these molecules can result in toxicity and acquired resistance, hence the need to develop novel kinds of EGFR-targeting drugs with high specificity and low toxicity. Here we generated, by a cell-Systematic Evolution of Ligands by EXponential enrichment (SELEX) approach, a nuclease resistant RNA-aptamer that specifically binds to EGFR with a binding constant of 10 nM. When applied to EGFR-expressing cancer cells the aptamer inhibits EGFR-mediated signal pathways causing selective cell death. Furthermore, at low doses it induces apoptosis even of cells that are resistant to the most frequently used EGFR-inhibitors, such as gefitinib and cetuximab, and inhibits tumor growth in a mouse xenograft model of human non-small-cell lung cancer (NSCLC). Interestingly, combined treatment with cetuximab and the aptamer shows clear synergy in inducing apoptosis in vitro and in vivo. In conclusion, we demonstrate that this neutralizing RNA-aptamer is a promising bio-molecule that can be developed as a more effective alternative to the repertoire of already existing EGFR-inhibitors.

Spheres derived from lung adenocarcinoma pleural effusions: molecular characterization and tumor engraftment

Malignant pleural effusions (MPEs) could represent an excellent source to culture a wide variety of cancer cells from different donors. In this study, we set up culture conditions for cancer cells deriving from MPEs of several patients affected by the most frequent form of lung cancer, namely the subset of non small cell lung cancers (NSCLC) classified as Lung Adenocarcinomas (AdenoCa) which account for approximately 40% of lung cancer cases. AdenoCa malignant pleural effusions gave rise to in vitro cultures both in adherent and/or in spheroid conditions in almost all cases analyzed. We characterized in greater detail two samples which showed the most efficient propagation in vitro. In these samples we also compared gene profiles of spheroid vs adherent cultures and identified a set of differentially expressed genes. Finally we achieved efficient tumor engraftment in recipient NOD/SCID mice, also upon inoculation of small number of cells, thus suggesting indirectly the presence of tumor initiating cells.

Morphological ultrasound microimaging of thyroid in living mice

The objective of the study was to explore high-frequency ultrasound (HFUS) for noninvasive microimaging of thyroid in living mice. Thyroid examination was performed by HFUS in 10 normal C57BL/6 mice, eight mice treated by propylthiouracil, and 22 Tg-TRK-T1 transgenic mice. The dimension of the gland and the presence of nodules were evaluated. Nodules were classified as malignant (hypoechogenicity, poorly defined margins, internal microcalcification, irregular shapes, and extra glandular extension) or not, and the findings were compared with histological data. Thyroid images were successfully obtained in all the animals analyzed. Normal thyroid reached a volume of 4.92 microl (range 2.11-4.92 microl). Mice with propylthiouracil-induced goiter showed diffuse thyroid enlargement (median volume 6.67 microl, range 4.09-8.82 microl). In 19 of 22 Tg-TRK-T1 mice (86%), HFUS identified a nodular process (the smallest detected nodule had a diameter of 0.46 mm). Eleven nodules were classified as malignant and eight as benign. Compared with histological analysis, HFUS showed a sensitivity of 100% in the detection of thyroid nodules and a specificity of 60% (two of the nodules identified by HFUS were not confirmed at the histology). The specificity and sensitivity of HFUS in predicting the malignancy of the thyroid nodules were 83 and 91%, respectively. Thus, HFUS is an accurate imaging modality that can potentially replace more invasive techniques, and, therefore, it represents a significant advancement in phenotypic assessment of mouse models of thyroid cancer.

Conditional inactivation of the E-cadherin gene in thyroid follicular cells affects gland development but does not impair junction formation

We have conditionally inactivated the E-cadherin gene in the thyroid follicular cells of mouse embryo to unravel its role in thyroid development. We used the Cre-loxP system in which the Cre-recombinase was expressed under the control of the tissue-specific thyroglobulin promoter that becomes active at embryonic d 15. At postnatal d 7, thyroid follicle lumens in the knockout mice were about 30% smaller with respect to control mice and had an irregular shape. E-cadherin was almost completely absent in thyrocytes, beta-catenin was significantly reduced, whereas no change in gamma-catenin was detected. alpha-Catenin was also reduced on the cell plasma membrane. Despite the dramatic loss of E-cadherin and beta-catenin, cell-cell junctions were not affected, the distribution of tight junction proteins was unaltered, and no increase of thyroglobulin circulating in the blood was observed. In addition, we found that other members of the cadherin family, the R-cadherin and the Ksp-cadherin, were expressed in thyrocytes and that their membrane distribution was not altered in the E-cadherin conditional knockout mouse. Our results indicate that E-cadherin has a role in the development of the thyroid gland and in the expression of beta-catenin, but it is not essential for the maintenance of follicular cell adhesion.

A physiological mechanism to regulate d-aspartic acid and NMDA levels in mammals revealed by d-aspartate oxidase deficient mice

Free D-aspartic acid and NMDA are present in the mammalian central nervous system and endocrine glands at significant concentrations, but their physiological role is still matter of debate. The only enzyme known to metabolize in vitro selectively these D-amino acids is D-aspartate oxidase (DDO). To clarify the role in vivo of the enzyme, we generated mice with targeted deletion of Ddo gene by homologous recombination. Mutated animals showed increased amounts of both D-aspartic acid and NMDA in all tissues examined demonstrating a physiological role of DDO in the regulation of their endogenous levels.

A mouse model demonstrates a multigenic origin of congenital hypothyroidism

Congenital hypothyroidism with thyroid dysgenesis (TD) is a frequent human condition characterized by elevated levels of TSH in response to reduced thyroid hormone levels. Congenital hypothyroidism is a genetically heterogeneous disease. In the majority of cases studied, no causative mutations have been identified and very often the disease does not show a Mendelian transmission. However, in approximately 5% of cases, it can be a consequence of mutations in genes encoding the TSH receptor or the transcription factors TITF1, FOXE1, or PAX8. We report here that in mouse models, the combination of partial deficiencies in the Titf1 and Pax8 genes results in an overt TD phenotype that is absent in either of the singly deficient, heterozygous mice. The disease is characterized by a small thyroid gland, elevated levels of TSH, reduced thyroglobulin biosynthesis, and high occurrence of hemiagenesis. The observed phenotype is strain specific, and the pattern of transmission indicates that at least two other genes, in addition to Titf1 and Pax8, are necessary to generate the condition. These results show that TD can be of multigenic origin in mice and strongly suggest that a similar pathogenic mechanism may be observed in humans.

Replacement of K-Ras with H-Ras supports normal embryonic development despite inducing cardiovascular pathology in adult mice

Ras proteins are highly related GTPases that have key roles in regulating growth, differentiation and tumorigenesis. Gene-targeting experiments have shown that, out of the three mammalian ras genes, only K-ras is essential for normal mouse embryogenesis, and that mice deprived of H-ras and/or N-ras show no major phenotype. We generated mice (HrasKI) in which the K-ras gene had been modified to encode H-Ras protein. HrasKI mice produce undetectable amounts of K-Ras but-in contrast to mice homozygous for a null K-ras allele-they are born at the expected mendelian frequency, indicating that H-Ras can be substituted for K-Ras in embryonic development. However, adult HrasKI mice show dilated cardiomyopathy associated with arterial hypertension. Our results show that K-Ras can be replaced by H-Ras in its essential function in embryogenesis, and indicate that K-Ras has a unique role in cardiovascular homeostasis.

An integrated regulatory network controlling survival and migration in thyroid organogenesis

The thyroid gland originates from the ventral floor of the foregut as a thickening of the endodermal cell layer. The molecular mechanisms underlying the early steps of thyroid morphogenesis are not known. Gene targeting experiments have contributed to the identification of several transcription factors, in general playing a role in the proliferation, survival, and migration of the thyroid cell precursors. The experiments reported here analyze the expression of the transcription factors Titf1, Hhex, Pax8, and Foxe1 in the thyroid primordium of null mutants of each of them. We found that most of these transcription factors are linked in an integrated regulatory network, each of them controlling the presence of other members of the network. The expression of Foxe1 is regulated in an intriguing fashion as it is strongly dependent on the presence of Pax8 in thyroid precursor cells, while the expression of the same gene in the pharyngeal endoderm surrounding the primordium is dependent on Sonic hedgehog (Shh)-derived signaling. Moreover, by the generation of mouse mutants expressing Foxe1 exclusively in the thyroid primordium, we provide a better understanding of the role of Foxe1 in these cells in order to acquire the competence to migrate into the underlying mesenchyme. In conclusion, we provide the first evidence of gene expression programs, controlled by a hierarchy of transcription factors expressed in the thyroid presumptive gut domain and directing the progression of thyroid morphogenesis.

Rhes is involved in striatal function

The development and the function of central nervous system depend on thyroid hormones. In humans, the lack of thyroid hormones causes cretinism, a syndrome of severe mental deficiency. It is assumed that thyroid hormones affect the normal development and function of the brain by activating or suppressing target gene expression because several genes expressed in the brain have been shown to be under thyroid hormone control. Among these, the Rhes gene, encoding a small GTP-binding protein, is predominantly expressed in the striatal region of the brain. To clarify the role of Rhes in vivo, we disrupted the Rhes gene by homologous recombination in embryonic stem cells and generated mice homozygous for the Rhes null mutation (Rhes(-/-)). Rhes(-/-) mice were viable but weighed less than wild-type mice. Furthermore, they showed behavioral abnormalities, displaying a gender-dependent increase in anxiety levels and a clear motor coordination deficit but no learning or memory impairment. These results suggest that Rhes disruption affects selected behavioral competencies.

In Vitro and In Vivo Characterization of Indium-111 and Technetium-99m Labeled CCK-8 Derivatives for CCK-B Receptor Imaging

Cholecystokinin (CCK) receptors of the subtype B (CCK-BR) have been shown to be overexpressed in certain neuroendocrine tumors including medullary thyroid cancer. Our recent work has focused on new methods to radiolabel the CCK8 peptide with 111In or 99mTc for CCK-B receptor imaging. Derivatives of CCK8 were obtained by addition at the N-terminus in solid phase of a DTPA derivative (DTPAGlu) linked through a glycine spacer (DTPAGlu-G-CCK8) or cysteine, glycine and a diphenylphosphinopropionyl moiety (PhosGC-CCK8) for labeling with 111In and 99mTc, respectively. CCK-BR overexpressing A431 cancer cell lines were utilized to characterize in vitro properties of the two compounds as well as for generating xenografts in nude mice for in vivo characterization. Both 111In-DTPAGlu-G-CCK8 and 99mTcPhosGC-CCK8 showed similar binding affinities for CCK-BR with dissociation constants of 20-40 nM, were internalized after interaction with the receptor and displayed prolonged cellular retention times. Specific in vivo interaction with the receptor of both CCK8 analogs was observed in our animal model. 111In-DTPAGlu-G-CCK8 showed better target to non-target ratios, although it appeared to be rapidly metabolized after injection and activity cleared through the kidneys. 99mTc-PhosGC-CCK8 was more stable in vivo but showed marked hepatobiliary clearance with resulting high background activity in the bowel. The rapid clearance and lower background obtained with 111In-DTPAGlu-G-CCK8 make this a better candidate for further development.

[Propofol, fentanyl, nitrous oxide: useful and current combination?]

The introduction of use of propofol in the anesthetists' pharmacopoeia has reinvigorated the research for a totally intravenous anaesthesia, for which the Authors propose a diagram. However, in experience related to the supplementary use of N2O, in virtue of its analgesic power, demonstrates yet another utility, permitting an easier anesthetical administration with minor consumption of intravenous drugs.