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T Testa

Publications and source records attributed to T Testa.

At least 19 recordsLinked to original sources
PubMed2003

The rabbit motilin receptor: molecular characterisation and pharmacology.

Following identification of the human motilin receptor, we isolated the rabbit orthologue by PCR amplification and found this to be 85% identical to the open reading frame of the human receptor. The protein encoded was 84% identical to the human polypeptide. In HEK293T cells transfected with the rabbit receptor, motilin concentration-dependently increased intracellular calcium mobilisation (pEC50=9.25). After transfection with Go1alpha, motilin similarly stimulated [35S]GTPgammaS binding (pEC50=8.87). Using both systems, similar values were obtained with the human receptor, with rank-order potencies of motilin=[Nle13]-motilin>erythromycin; ghrelin was ineffective. In circular muscle preparations of rabbit gastric antrum, [Nle13]-motilin 0.1-30 nM concentration-dependently increased the amplitude of electrically-evoked, neuronally-mediated contractions (pEC50=8.3); higher concentrations increased the muscle tension (30-3000 nM). Both responses to [Nle13]-motilin faded rapidly during its continual presence. Rat or human ghrelin 0.01-10 microM were without activity. Erythromycin 30-3000 nM and 10 microM, respectively, increased neuronal activity and muscle tension in rabbit stomach. Unlike [Nle13]-motilin, the increase in neuronal activity did not fade during continual presence of submaximally-effective concentrations of erythromycin; some fade was observed at higher concentrations. We conclude that the pharmacology of the rabbit motilin receptor is similar to the human orthologue and, when expressed as a recombinant, comparable to the native receptor. However, in terms of their ability to increase neuronal activity in rabbit stomach, [Nle13]-motilin and erythromycin are distinguished by different response kinetics, reflecting different rates of ligand degradation and/or interaction with the receptor.

Animals↗
PubMed2000

A new remote-controlled endoscope positioning system for endoscopic solo surgery. The FIPS endoarm.

In the field of endoscopic solo surgery, the assistance received by the surgeon from ergonomical positioning devices is extremely important. They aid in both the retracting of instruments and the positioning of the endoscope. However, passive systems derived from open surgery have not proved satisfactory. Therefore, we set out to develop a remote-controlled arm capable of moving a rigid endoscope with about four degrees of freedom, while maintaining an invariant point of constraint motion coincident with the trocar puncture site through the abdominal wall. The system is driven by means of speaker-independent voice control or a finger-ring joystick clipped onto the instrument shaft close to the handle. When the joystick is used, the motion of the endoscope is controlled by the fingertip of the operating surgeon, which is inserted into the small ring of the controller in such a way as to make the motion of the fingertip correspond directly to the motion of the tip of the endoscope. A study was performed to compare the two different interfaces available for the system. With both interfaces, the guiding system allows for transparent and intuitive operation. Its set-up is easy; it is safe and reliable to use during the intervention; and it is faster than human assistance. With its improved ergonomy, this new generation of remote-controlled endoscope positioning system represents a further step toward the diffusion of solo surgery techniques in minimally invasive therapy. In our opinion, this prototype creates a valid compromise between human and robotic control of rigid endoscopes.

Animals↗
PubMed2000

The human GABA(B1b) and GABA(B2) heterodimeric recombinant receptor shows low sensitivity to phaclofen and saclofen.

1. The aim of this study was to characterize the pharmacological profile of the GABA(B1)/GABA(B2) heterodimeric receptor expressed in Chinese hamster ovary (CHO) cells. We have compared receptor binding affinity and functional activity for a series of agonists and antagonists. 2. The chimeric G-protein, G(qi5), was used to couple receptor activation to increases in intracellular calcium for functional studies on the Fluorimetric Imaging Plate Reader (FLIPR), using a stable GABA(B1)/GABA(B2)/G(qi5) CHO cell line. [(3)H]-CGP-54626 was used in radioligand binding studies in membranes prepared from the same cell line. 3. The pharmacological profile of the recombinant GABA(B1/B2) receptor was consistent with that of native GABA(B) receptors in that it was activated by GABA and baclofen and inhibited by CGP-54626A and SCH 50911. 4. Unlike native receptors, the GABA(B1)/GABA(B2)/G(qi5) response was not inhibited by high microMolar concentration of phaclofen, saclofen or CGP 35348. 5. This raises the possibility that the GABA(B1)/GABA(B2)/G(qi5) recombinant receptor may represent the previously described GABA(B) receptor subtype which is relatively resistant to inhibition by phaclofen.

Animals↗
PubMed2000

[Positioning systems for endoscopic solo surgery].

BACKGROUND: Endoscopic surgery has acquired undisputed importance in the field of both general and specialised surgery. The introduction of robotic technology in surgery has recently led to the development of new positioning systems for endoscopic surgery. These allow direct control of the endoscopic procedures by the surgeon, whose vision currently depends on the assistant in charge of positioning the optic camera in compliance with his wishes. METHODS: We experimented different positioning systems for optics and rigid endoscopic instruments for laparoscopy, some of which were our own design. Over 400 cholecystectomies were carried out by six different surgeons on phantoms containing animal organs. The experimental systems were AESOP (Computer Motion, USA), with both foot-pedal and voice control, ENDOASSIST (Armstrong Healthcare Co. UK), controlled by a device worn by the surgeon, FIPS Endoarm (Karlsruhe Research Centre, Germany), controlled by a joystick and voice, and the passive TISKA Endoarm system (Karlsruhe Research Centre, Germany). Combinations of two systems were compared, using one to position the optic and one to position the retractor instrument. RESULTS: Phantom tests, which are preferable owing to constant conditions, showed the feasibility of experiments in Solo Surgery conditions and highlighted the advantages and drawbacks of the various systems. In particular, the surgeons appreciated the intuitive use of the TISKA Endoarm system as a positioner for the retractor instrument and the optics, in spite of the fact that it was only a passive movement apparatus. Among the remote-control systems tested as an optics positioner, FIPS Endoarm controlled by a joystick was particularly intuitive and produced the best results in terms of time taken to complete the procedure. The time taken was even shorter than that in a large control group with human assistance. CONCLUSIONS: In our experience endoscopic Solo Surgery was found to be applicable to clinical practice. This will bring numerous advantages in terms of the precision of surgical procedures and savings in terms of time and human resources, with a consequent reduction of management costs. There is no doubt that this method represents a step forward in the application of technology to surgery.

Endoscopes↗
PubMed1999

Molecular and pharmacological characterization of a functional tachykinin NK3 receptor cloned from the rabbit iris sphincter muscle.

1. A functional tachykinin NK3 receptor was cloned from the rabbit iris sphincter muscle and its distribution investigated in ocular tissues. 2. Standard polymerase chain reaction (PCR) techniques were used to clone a full length rabbit NK3 receptor cDNA consisting of 1404 nucleotides. This cDNA encoded a protein of 467 amino acids with 91 and 87% homology to the human and rat NK3 receptors respectively. 3. In CHO-K1 cells transiently expressing the recombinant rabbit NK3 receptor, the relative order of potency of NKB>>NKA>/=SP to displace [125I]-[MePhe7]-NKB binding and to increase intracellular calcium, together with the high affinity of NK3 selective agonists (e.g. senktide, [MePhe7]-NKB) and antagonists (e.g. SR 142801, SB 223412) in both assays was consistent with NK3 receptor pharmacology. In binding and functional experiments, agonist concentration response curves were shallow (0.7 - 0.8), suggesting the possibility of multiple affinity states of the receptor. 4. Quantitative real time PCR analysis revealed highest expression of rabbit NK3 receptor mRNA in iris sphincter muscle, lower expression in retina and iris dilator muscle, and no expression in lens and cornea. In situ hybridization histochemistry revealed discrete specific localization of NK3 receptor mRNA in the iris muscle and associated ciliary processes. Discrete specific labelling of NK3 receptors with the selective NK3 receptor agonist [125I]-[MePhe7]-NKB was also observed in the ciliary processes using autoradiography. 5. Our study reveals a high molecular similarity between rabbit and human NK3 receptor mRNAs, as predicted from previous pharmacological studies, and provide the first evidence that NK3 receptors are precisely located on ciliary processes in the rabbit eye. In addition, there could be two affinity states of the receptor which may correspond to the typical and 'atypical' NK3 receptor subtypes previously reported.

Amino Acid Sequence↗
PubMed1997

Transcellular metabolism of leukotriene A4 by rabbit blood cells: lack of relevant LTC4-synthase activity in rabbit platelets.

The objective of this study was to determine the transcellular metabolism of leukotriene A4 by rabbit blood cells. mixed peripheral blood leukocyte preparations with and without platelets in a ratio of 1:40 were challenged with the Ca(2+)-ionophore A23187. 5-Lipoxygenase metabolites production was assessed by RP-HPLC coupled with diode-array UV detection. In light of the observation that leukotriene C4 production in leukocyte-platelet coincubation was the same as with leukocytes alone, mixed coincubation of human and rabbit blood cells was tested. Rabbit leukocytes with human platelets resulted in a significant increase of leukotriene C4 production, while no changes were observed in human leukocytes with or without rabbit platelets. In agreement with these results, intact rabbit platelets or rabbit platelet lysates, unlike human platelets, were not able to convert synthetic leukotriene A4 free acid to leukotriene C4. These data provide evidence that rabbit leukocytes are able to make a significant amount of leukotriene A4 available for transcellular metabolism, while rabbit platelets, unlike human platelets, lack leukotriene C4-synthase activity.

Animals↗
PubMed1996

Leukotriene A4, and not leukotriene B4, is the main 5-lipoxygenase metabolite released by bovine leukocytes.

The production of leukotriene A4 (LTA4)-derived metabolites, analysed by RP-HPLC, was studied in purified bovine polymorphonuclear leukocyte (PMNL) preparations and in PMNL-platelet coincubations after challenge with the calcium ionophore A23187. The results obtained show that in bovine PMNL LTB4 represents the main LTA4 metabolite. When washed platelets were added to PMNL, LTC4 was the main enzymatic metabolite observed, indicating a substantial transfer of PMNL-derived LTA4 to platelets. The synthesis of LTC4 was accompanied by a significant decrease in LTB4, suggesting that a quota of the LTB4 synthesized in PMNL preparations is the result of transcellular metabolism of released LTA4 by neighbouring PMNL. Reduction of PMNL-PMNL interactions through dilution of cell incubates allowed us to estimate that most of the leukotriene A4 synthesized by PMNL is indeed released from the cell. LTA4, and not LTB4, represents the main 5-lipoxygenase metabolite released by bovine PMNL.

Animals↗
PubMed1996

Myocardial protection by the leukotriene synthesis inhibitor BAY X1005: importance of transcellular biosynthesis of cysteinyl-leukotrienes.

Perfusion of the isolated rabbit heart with 5 x 10(6) human polymorphonuclear leukocytes, under recirculating conditions (50 ml), and challenge with A-23187 (0.5 microM) caused an increase in coronary perfusion pressure (from a prechallenge value of 46 +/- 1.1 to 176.2 +/- 29.7 mm Hg, 30 min after challenge, n = 6-4), which was linearly correlated (P < .006) with formation of cysteinyl leukotrienes (29.7 +/- 7.3 pmol/ml, 30 min after challenge). Pretreatment with the leukotriene synthesis inhibitor BAY X1005 (1 microM) (n = 6) resulted in significant protection against the increase in coronary perfusion pressure (76.7 +/- 12.8 mm Hg, 30 min after challenge) and in almost complete inhibition of sulfidopeptide leukotriene synthesis (3.2 +/- 1.7 pmol/ml, 30 min after challenge). In in vivo experiments, ligation of the left anterior descending coronary artery in the rabbit (n = 10) resulted in acute myocardial infarction marked by a mortality rate of 60% compared with sham-operated animals (n = 10). Intravenous treatment of the rabbits with BAY X1005 (10 mg/kg/h, for 2 h) (n = 10) markedly reduced the mortality rate (20%), protected the rabbits against the marked electrocardiogram derangement and abolished the significant increase in plasma creatine phosphokinase activity and cardiac tissue myeloperoxidase activity induced by coronary artery ligation. BAY X1005 exerts a significant cardioprotection and suggests that specific leukotriene synthesis inhibitors may lead to innovative therapy in myocardial ischemia.

Animals↗
PubMed1996

Consensus on diuresis renography for investigating the dilated upper urinary tract. Radionuclides in Nephrourology Group. Consensus Committee on Diuresis Renography.

UNLABELLED: There is great variation in technique and interpretation of diuresis renography between different establishments. METHODS: To address this problem, an International Consensus Committee was appointed by the Ninth International Symposium on Radionuclides in Nephrourology in 1994. RESULTS: The final document was produced and addressed: objectives, equipment, data acquisition, choice of radiopharmaceutical, patient preparation, position, dosage of furosemide, timing of furosemide, role of bladder catheter, duration of study, pediatric considerations, evaluation of the furosemide response, interpretation, and conclusion. CONCLUSION: The report presents a standardized approach to diuresis renography that, if adopted, will improve reproducibility between centers, discourage unacceptable practice and stimulate further discussion between nuclear medicine and urology health care professionals who treat patients with dilated and obstructed upper urinary tracts.

Adolescent↗
PubMed1995

[Adhesive peritonitis caused by a foreign body. A case report].

After investigation of the international literature on this subject, the authors describe a case report of adhesive-stenotic and retractile peritonitis, very likely caused bt a foreign body reaction (surgical stitches, gloves, rice powder, etc.?). This case-report is interesting both to remember the existence of this pathology and to limit its iatrogenic development. In conclusion, it is advisable to wash surgical gloves with sterile solutions and to limit enlarged bowel resections mostly in young people.

Adolescent↗
PubMed1995

[Lobar bronchoplasty for tumor. Surgical technique and long-term results].

Between 1978 and 1994, 55 patients (53 men and 2 women) with a mean age of 62 years underwent an extended lobectomy to the main bronchus, with bronchial re-anastomosis, for bronchogenic tumours located around the lobar orifice. There were 32 upper sleeve lobectomies (58%) with a wedge resection of carina in one instance, 7 lower mono/bilobectomies with an upper lobe "turn up" re-anastomosis (13%) and 16 upper wedge lobectomies (29%). Squamous cell carcinoma was predominant (32 patients, 58%), while the adenocarcinoma was present in 16%, adenosquamous in 5%, microcitoma in 9%, carcinoid in 4% and a well differentiated neuro-endocrine carcinoma in 2%. The indication for the bronchoplastic procedure was judged to be when the FEV, value was about -25% of the normal; in a few patients still in good respiratory condition, an elective indication was also admitted. Postoperative staging was: Stage 0 in 1 patient, Stage I in 7 patients; Stage II in 10 patients; Stage III A in 31 patients; Stage III B in 5 patients and Stage IV in 1 patient. Follow-up was completed with a mean extension of 40 months (range 3 months-16 years). There was no operative mortality in Stages I and II as well as in Stages III B and IV, while it was 9% in Stage III A patients. Survival rates according to the stage were as following: 66% 5 and 10 year for Stage I disease; 56% 5 year and 45% 10 year for Stage II disease; 7% 4 year for Stage III A. None of 5 patients belonging to Stage III B has survived for more than 18 months (mean 7). Some single survivals are mentioned because of their special clinical features. Besides stressing the absolute value of survival rates obtained in Stage I and II disease, the Author also point out the clinical role of these advanced surgical techniques in improving both the survival length and the quality of life, when applied for the treatment of more advanced Stage III A.

Adult↗
PubMed1993

[Prognostic significance of cell-mediated immune response in patients with colorectal carcinoma. Preliminary results].

Pre-operative skin test response has been evaluated in 50 cases of colorectal carcinoma. Cellular defense's depression was correlated with tumoral staging (p = < 0.001). In B2 and C groups, a higher incidence of metastatic and local recurrences was registered in subjects with low response. These last are suitable for a randomized trial including immunotherapy.

Colorectal Neoplasms↗
PubMed1990

[Nuclear DNA content in tumors of the colon and rectum. Relationship between ploidy and site of the neoplasm].

The DNA distribution pattern was determined 30 colo-rectal carcinomas. The DNA content in individual cells was measured according to a cytophotometric method based on light transmission measurement of Feulgen-stained nuclei. The DNA non diploid carcinomas were significantly more common from the left (descending and sigmoid) colon and rectum (P = 0.0002). No relationship existed between DNA pattern and age, sex, Dukes' stage, tumor grade.

Adenocarcinoma↗
PubMed1990

[The reliability of the grading assessment of the biopsy samples in malignant colorectal neoplasms].

The authors evaluate the results of preoperative bioptic grading compared with those obtained from postoperative specimens. Altogether, there was nonagreement in 45% of cases; therefore there is the risk of underestimating the biological aggressiveness of the disease. In fact, 68% of patients who were assessed as G1 in preoperative staging were found to have a higher degree of neoplastic dedifferentiation.

Adult↗