Biomedical subjects
Publications and source records attributed to G Tritto.
Testicular descent is a complex mechanism influenced by hormonal and anatomical factors. Whatever the age of the patient or the descent technique used for either one or both testes, there is a risk of degeneration and sterility counts. Anatomical studies and the results of sperm are important, hence the importance of establishing a precise anatomical and therapeutic classification.
Explore the source record for details and available documents.
Measurement of postheparin plasma diamine oxidase (PHD) activity has been proposed to assess mucosal integrity in several diseases of the small intestine. In Crohn's disease, PHD values identify a group of patients with predominantly small bowel mucosal damage. To determine the role of mucosal involvement in the progression of small bowel Crohn's disease and whether different PHD values can predict different outcomes the changes in PHD values in 41 patients with small bowel Crohn's disease admitted consecutively to our department were investigated. The test was performed during periods of active disease and after either medical or surgical treatment had resulted in improvement. PHD values were significantly lower than in normal subjects (normal range 3.7-7.7 U/ml). In 35 patients with active disease (Crohn's disease activity index (CDAI) greater than 150) two groups were identified by choosing a cut off value of 2 U/ml: 93% of the 15 patients with PHD values lower than 2 U/ml (mean (SD) 1.36 (0.46) U/ml) relapsed at least once in the following year, while only the 20% of the 20 whose values were higher than 2 U/ml (mean (SD) 3.69 (1.50)) relapsed in the same period. The data were statistically significant (Yates's corrected chi 2 = 15.63; p less than 0.0001). The positive and negative predictive values of the test were 93% and 80%, respectively. During relapses, PHD values were consistently lower than previous values, and increased significantly after effective medical or surgical treatment. In the six patients in whom there were no changes in disease activity (CDAI persistently less than 150), there was no change in PHD values. This test may be useful for identifying Crohn's disease patients who are likely to relapse. Furthermore, the data indicate that mucosal damage is common in active small bowel Crohn's disease and improves at least in part after treatment.
The intracellular concentrations of the polyamines are highly regulated and high polyamine concentrations are associated with rapidly proliferating cells. Hormones, nutrients and growth factors that stimulate the proliferation of the intestinal epithelium, increase the intracellular polyamine concentration mainly by activating ODC expression. Other cell types stimulated to proliferate satisfy their requirement for polyamines by increasing polyamine uptake. In the present study, we investigated polyamine uptake by a human colon carcinoma cell line, CaCo-2. Uptake of putrescine, spermidine and spermine by CaCo-2 cells was saturable and temperature dependent and all polyamines appear to share a common carrier. The carrier of differentiated cells had an apparently higher affinity and lower activity than the carrier of replicating cells. Culture of CaCo-2 cells on porous filters showed that polyamine accumulation occurred mainly through the basolateral membrane in replicating cells, while an increase in the rate of apical uptake was observed after differentiation. A significant increase in polyamine uptake and in ODC expression resulted from fresh medium replacement, a well-known stimulus to proliferation; no change in uptake occurred after ODC inhibition by DFMO. We conclude that CaCo-2 cells are able to increase their polyamine concentration by both enhanced synthesis and increased polyamine uptake.
Ornithine decarboxylase (ODC) and diamine oxidase (DAO), enzymes involved in polyamine metabolism, are highly expressed by small bowel enterocytes. Modulation of ODC expression is mediated through cellular concentration of polyamines that inhibits the enzyme synthesis and also induces the synthesis of an inhibitory protein, the antizyme, which in turn binds to ODC and inhibits its activity. DAO is an important regulator of intracellular concentration of polyamines because it catalyzes the degradation of putrescine into gamma-aminobutyraldehyde. Change in intracellular polyamine concentration has been suggested to represent a regulatory factor for DAO expression. In order to investigate a possible regulation of DAO expression by ODC, we studied the effect of difluoromethylornithine (DFMO), a selective, irreversible inhibitor of ODC, on DAO activity in isolated rat small bowel enterocytes. Our data demonstrate that in isolated small bowel enterocytes ODC inhibition by 10 mM DFMO reduced DAO activity by 53%, suggesting that, in our experimental conditions, ODC plays a regulatory role on DAO expression.
A new reconstructive microsurgical model of the epididymo-deferential complex was performed in the rat to study the plastic adaptation of the distal epididymal tubule in transposition and/or substitution procedures. The model consists of three steps: endoluminal stripping of the mucosa of the proximal half of the vas deferens; pull-through technique for the advancement of the unfolded epididymal tubule of the "zone 9" into the stripped vas deferens; end-to-end tubulo-deferential telescopic reconstruction.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
First results of the comparison between the electrical activity of taenia coli and circular muscle are described. Experimental techniques consisted in recording electrical activity for 83 h in 12 patients during the post-operative period after cholecystectomy. Bipolar wire electrodes were surgically inserted in each muscle of the transverse colon's median portion. Statistical treatment leads to the principal conclusion as follows: Whatever type of muscles we have investigated, always could be found slow rhythmic components (called electro-control activity, ECA) in frequency ranges of 1-5 c/min and 9-12 c/min. Major part of taenia coli ECA is in frequency range between 1-5 c/min. ECA in this frequency range can be found in 21% of circular ECA, 23% of taenia coli ECA and 9% of common ECA (% means percents of total recording time). Higher frequencies are found in 7% of circular ECA, 4% of taenia coli ECA and 3% of common ECA. Using long time constant (more than 2 s) the bursts of spikes (10-50 microV) meaning active responses are always accompanied with slower components of important amplitude (greater than or equal to 100 microV): In the discrete mode of activity (DERA) short bursts (during 1-2.5 s) always follow the ECA, whereas in the continuous mode of activity (CERA) mostly longlasting bursts (up to 30 s) could be found. The bursts represent 14% of total time, namely in 8% of longitudinal ECA, 4% of circular ECA and 2% of common ECA. ECA of taenia coli in the case of common ECA is always prolonged. Typical slow waves of greater amplitude (greater than or equal to 500 microV) different from ECA are frequently recorded probably due the intensive contractile process.
Electrical activity of the colon was investigated in the postoperative period in 12 patients, 1 to 6 days after cholecystectomy. The polygraphic records are obtained during 2 hours each day late in the morning (10-12 h) in a preprandial situation from serosal implantation of bipolar copper wires inserted into each circular and longitudinal layer in narrow portion of the middle part of the transverse colon. The time presence diagrams was built up after recognition of the basic patterns activity previously definite by Sarna as follows: Electro-Control-Activity, with it slow waves (ECA), Electro-Response-Activity (ERA) with Discrete bursts (DERA) or Continuous ones (CERA). In the former postoperative period 1 to 3 days ECA is present with a low range frequency 1-5 c/min. The higher frequency (10-12 c/min) activity arises sporadically, in this case associated with DERA bursts. From the 4th day all activities ECA and DERA increase significantly. The continuous response activity CERA may be observed in all periods but more frequently from the 3rd day with the same mean duration (12.4 +/- 1.85 s for the circular fibers and 21.6 +/- 2.56 s for the longitudinal ones); the predominance of longitudinal activity duration is significative (p = .001). The complex CEC (26-40 c/min) associated with CERA is observed only in 3% of the time recording. Thus after the onset of colonic motility with DERA and CERA in the 3th day, the normalization is obtain the 6th day with the predominant rythm of 1-2 c/min.