Cocoa by-product inclusion in dairy sheep diet: effect on sensory, volatile and antioxidant properties of cheese.

The possibility of inclusion of agro-industrial by-products in the diet of small ruminants represents both an economical and an environmental strategy for reducing waste management by industries and the cost of feeding as well as the impact of livestock farming. Large amounts of wastes from the cocoa industry are annually produced with a considerable part represented by cocoa bean shells, considered a suitable ingredient to be included in the diet of ruminants within the limits established by European legislation. The aim of this study was to assess the effect of including cocoa bean shells in the diet of dairy sheep on the sensory, volatile, and antioxidant properties of cheese. To this purpose, 20 Comisana lactating ewes were randomly assigned to 2 experimental groups: control (CTRL) and cocoa bean shells (CBS), and received alfalfa hay ad libitum and 800g of conventional (CTRL) or experimental (CBS) concentrate containing 11.7% CBS to partially replace corn and barley of the CTRL concentrate. Bulk milk collected from each group was used to produce a total of 15 cheeses per group, obtained in 5 different days of cheese-making (3 cheeses a day per group). After 60 d of aging, each cheese of each experimental group was sampled for the analyses. The results on chemical composition revealed a greater monounsaturated fatty acids content and an increase in the nutritional indices suggesting a favorable role of cocoa bean shells dietary inclusion on the nutritive value of the cheese. The cheese sensory profile was affected by the cocoa bean shells inclusion, with more pronounced appearance, odor, aroma, and taste attributes in the product. The volatile profile showed only a few significant differences, mainly related to the cheese ripening process, and no differences were found in α-tocopherol contents in cheese fat between the 2 groups. Therefore, the coca bean shells inclusion in the diet of dairy sheep allowed to obtain a good quality cheese, without altering the characteristics associated with the typical profiles of sheep cheese. Furthermore, the use of this by-product could contribute to decrease feed costs and waste management, representing a good practice for increasing the sustainability of dairy products.

Clinical and oncological outcomes in single-stage versus staged surgery for pediatric craniopharyngiomas: a multicenter retrospective study.

PURPOSE: Craniopharyngiomas (CPGs) are aggressive brain tumors responsible of severe morbidity in children. The best treatment strategies are under debate. Our study evaluates surgical, pituitary, and hypothalamic outcomes of a tailored staged-surgical approach compared to a single-stage radical approach in children with CPGs. METHODS: Multicenter retrospective study enrolling 96 children treated for CPGs in the period 2010-2022. The surgical management was selected after a multidisciplinary evaluation. Primary endpoint includes the inter-group comparison of preservation/improvement of hypothalamic-pituitary function, the extent of resection, and progression-free survival (PFS). Secondary endpoints include overall survival (OS), morbidity, and quality of life (QoL). RESULTS: Gross Total Resection (GTR) was reached in 46.1% of cases in the single-stage surgery group (82 patients, age at surgery 9 ± 4.7 years) and 33.3% after the last operation in the staged surgery group (14 patients age 7.64 ± 4.57 years at first surgery and 9.36 ± 4.7 years at the last surgery). The PFS was significantly higher in patients addressed to staged- compared to single-stage surgery (93.75% vs 70.7% at 5 years, respectively, p = 0.03). The recurrence rate was slightly higher in the single-stage surgery group. No significant differences emerged in the endocrinological, visual, hypothalamic outcome, OS, and QoL comparing the two groups. CONCLUSIONS: In pediatric CPGs' surgical radicality and timing of intervention should be tailored considering both anatomical extension and hypothalamic-pituitary function. In selected patients, a staged approach offers a safer and more effective disease control, preserving psychophysical development.

Inclusion of cocoa by-product in the diet of dairy sheep: Effect on the fatty acid profile of ruminal content and on the composition of milk and cheese.

In this study, we hypothesized that dietary cocoa bean shell (CBS) as a partial replacer of human edible cereal grains in the diet of lactating ewes may affect performance and milk and cheese composition. Twenty Comisana lactating ewes allotted into control (CTRL; n = 10) or cocoa (CBS; n = 10) group received alfalfa hay ad libitum and 800 g of conventional (CTRL) or experimental (CBS) concentrate containing 11.7% CBS to partially replace corn and barley of the CTRL concentrate. Milk yield and composition did not differ between groups, and only urea concentration was lower in CBS milk. Dietary CBS increased cheese fat and reduced protein percentage in CBS group. Fatty acid composition of rumen content partially reflected that of the ingested diet, with total saturated fatty acids (SFA), total monounsaturated fatty acids (MUFA), 16:0, 18:0 and 18:1c9 greater in the CBS group. Moreover, all the identified trans- and cis-18:1 isomers were greater in CBS rumen content. Milk and cheese showed a similar fatty acid composition. Total MUFAs were greater in milk and cheese of CBS, mainly due to the proportion of 18:1c9, and conversely, total polyunsaturated fatty acids (PUFA), PUFAn-6 and PUFAn-6-to-PUFAn-3 ratio was greater in CTRL group. Concluding, the inclusion of CBS in the diet of lactating ewes within the limit imposed by the current legislation did not cause detrimental effects on animal performance and milk composition. Interestingly, dietary CBS reduced milk urea concentration probably due to the phenols contained in CBS concentrate. However, our results support that biohydrogenation was weakly impaired by dietary CBS. Finally, CBS negatively affected cheese nutritional characteristics due to lower protein and greater fat content, but improved fat health indexes in milk and cheese.

Fournier's gangrene as a rare complication in patient with uncontrolled type 2 diabetes treated with surgical debridement: A case report and literature review.

INTRODUCTION: Fournier's gangrene is a potentially fatal emergency condition, supported by an infection of perineal and perianal region, characterized by necrotizing fasciitis with a rapid spread to fascial planes. FG, usually due to compromised host, may be sustained by many microbial pathogens. CASE REPORT: A 66-year-old man, with a history of uncontrolled type 2 diabetes, obesity with BMI 38, chronic kidney failure and chronic heart failure, was admitted to the Emergency Department with a large area of necrosis involving the perineal and perianal regions. DISCUSSION: Fournier's gangrene is favoured by hypertension, obesity, chronic alcoholism, renal and heart failure. Generally, Fournier's gangrene needs other procedures in addition to wound debridement such as colostomy, cystostomy, or orchiectomy. CONCLUSION: We report a case of FG found as complication in a patient with uncontrolled type 2 diabetes, treated with effective combination therapy with surgical debridement and antibiotics infusion.

Pattern of recurrence and survival of c-Ia NSCLC diagnosed by transpleural methods.

AIM: The aim of this study was to evaluate if transpleural diagnostic methods as percutaneous fine-needle aspiration biopsy (FNAB) or tumour wedge resection by video-assisted thoracoscopic surgery (VATS) impact on local recurrence and long term survival of patients affected by non-small cell lung cancer (NSCLC). METHODS: Records concerning 179 patients with peripheral c-Ia NSCLC who underwent complete resection from 1994 to 2000 have been reviewed. Patients were randomized into two groups according to the diagnostic method employed, as follows: in group I (N.=63) diagnosis was obtained by bronchoscopy; in group II (N.=116) diagnosis was obtained by FNAB (N.=59) or tumour wedge resection by VATS (N.=57) after a negative bronchoscopy. Survival curves were compared using log-rank test. Distribution of frequencies was analyzed with Chi-square and Fisher's exact test. RESULTS: The two groups of patients did not significantly differ in terms of age, gender, forced expiratory volume in 1 second, comorbidities, histological type and tumour size; pathologic stage IIb was more frequent in group I. At a median follow-up of 48 months, (range 2-108 months), local recurrence was found in 9.5% (N.=6) of the patients in group I and in 12.5% (N.=15) of patients in group II (P=NS); distant metastasis were found in 28.6% (N.=18) of patients in group I and in 13.8% (N.=16) in group II (P=0.03). Patients in group II had a statistically better five-year survival rate than patients in group I (70% and 55% respectively P=0.016). CONCLUSION: FNAB and tumour wedge resection by VATS represent valuable diagnostic methods for lung cancers, since they do not seem to increase the risk of local recurrence. On the other hand, tumours diagnosed by bronchoscopy have a worse prognosis, that may be related to their higher metastatic potential rather than to diagnostic procedure itself.

A case of primary malignant hemangiopericytoma of the heart with fatal outcome.

Hemangiopericytoma is a rare, highly vascular tumor which has both malignant and benign varieties. We report a case of a 41-year-old man who underwent surgery in emergency because of cardiac tamponade. The histopathologic examination of the specimens revealed primary malignant cardiac hemangiopericytoma. The patient died 46 days from the beginning of symptoms and 13 days after surgery.

Late outcome and perioperative complications for surgery of locally recurrent bronchogenic carcinoma.

AIM: Many doubts involve a 2(nd) surgical approach for local relapse of non small cell lung cancer (NSCLC) since iterative resections represent a well-recognized treatment in second primary lung cancer (SPLC). METHODS: The medical reports of patients who underwent surgical resection, between 1988 and 2002, were reviewed. All patients submitted to 2(nd) operation were examined according to Martini and Melamed criteria to distinguish between local recurrence and second primary lung cancer. RESULTS: Complete resection for NSCLC was performed in 1 386 patients. Nineteen patients were submitted to surgery for local recurrence (17 men and 2 women) and mean age at the time of 1(st) operation was 61 years (range 41-78 years). The 1(st) operation consisted of lobectomy in 15 cases, anatomical segmentectomy in 2 and wedge resection in 2. The 2(nd) pulmonary resection was completion pneumonectomy in 16 cases, completion lobectomy in 2, wedge resection in 1. Major complications occurred in 26% and overall hospital mortality was 5%. Five-year survival after 2(nd) intervention was 31% and median survival 27 months. Survival was better when the time between 1(st) resection and cancer relapse was longer than 14 months and when recurrence was intrapulmonary. CONCLUSIONS: A new malignant lesion can be operated if it is solitary and intrapulmonary, if accurate staging is negative and if the patient is able to go through 2(nd) surgery from cardiopulmonary evaluation.

Ten year experience of bioabsorbable mesh support in pectus excavatum repair.

INTRODUCTION: We reviewed 10 years experience in the treatment of this deformity using a retro-sternal bioabsorbable mesh in place of a metallic device to lift and stabilise the sternum. Moreover, the mesh supports the thoracic and upper abdominal wall reconstruction. MATERIALS AND METHODS: From January 1990 to December 2000, in our Thoracic Surgery Unit, 65 patients with PE were assessed for surgical repair, mean age 16+/- 3.5 years, fronto sagittal thoracic index (FSTI) 0.21, ranging from 0.15-0.33. Twenty-three of them underwent surgical correction after initial assessment, 22 were deferred and sent to physiotherapy. At a subsequent assessment, five of the patients sent to physiotherapy were deemed to require surgery. RESULTS: Of the 28 patients who underwent surgery, 2 (10%) presented a mild recurrence of PE after 1 year (0.300.34), meanwhile all other patients maintained a FSTI>0.34. For all patients the improvement in FSTI was statistically significant, p = 0.001. Patients satisfaction after 24 months was thus shared: excellent 18 patients (65%), good seven patients (25%), fair one patient (3.5%) and poor two patients (7%). No major complications were observed in preoperative period. Patients mobilisation was soon achieved thanks to the postoperative pain control and the absence of retro-sternal metallic support. CONCLUSIONS: The introduction of bioabsorbable mesh in the Robicsek technique is a safe procedure related to a high percentage of success. The high tolerance of the material reduces the inflammatory reaction. Moreover, the procedure prevents patients from having complications caused by retro-sternal device dislodgment, avoiding a second intervention for device reposition and reducing the postoperative chest pain achieving an early patient mobilisation. In the end a complete reconstruction of the upper abdomen wall has been produced.

Right pneumonectomy for adenocarcinoma stage IIIA-N2 in a heart transplant patient after induction chemotherapy.

Lung tumors are the most frequent solid tumor in the heart transplant population. Unfortunately, most of these patients are in an advanced stage of disease at the time of presentation, which carries a poor prognosis. We present a heart transplant patient with histologically proven. Stage IIIA-N2 bronchogenic adenocarcinoma who had complete lymph-node downstaging after induction chemotherapy and underwent a complete tumor resection by right pneumonectomy.

Comparison between segmentectomy and larger resection of stage IA non-small cell lung carcinoma.

AIM: Stage IA non small cell lung carcinoma (NSCLC) represents early cancer and is best treated by surgery. The frequency of recurrence and new primary cancer varies from one report to another while the role of sublobar resection is still debated. METHODS: We retrospectively reviewed 121 consecutive patients with pathological stage IA after radical surgery. RESULTS: In stage IA NSCLC 1-, 3-, 5-year survival rates were 89%, 76% and 66%. Nearly half of the deaths were unrelated to the original cancer. From statistical analysis we did not find any factor indicative of a better prognosis. We did not find any difference in survival between histologic types. Segmentectomy did not show a worse survival rate compared with larger resection. CONCLUSION: Survival is neither influenced by the type of resection nor by the histologic types in stage IA. However, we noticed a high incidence of local recurrence, segmentectomy could be a viable choice in patients with cardiopulmonary impairment.

Sudden onset of thoracic pain: neurofibroma with intracystic haemorrhage.

Intercostal nerve sheath tumors are normally benign and asymptomatic. Nevertheless surgical resection can eliminate the risk of malignant transformation and also achieve complete remission in case of symptoms.

Pneumonectomy vs lobectomy in the treatment of pathologic N1 NSCLC: could the type of surgical resection dictate survival?

AIM: To define the prognostic significance of specific types of N1 lymph node involvement in patients operated on for stage II (N1) NSCLC and to evaluate if the extent of resection affects survival. METHODS: Of 1117 patients operated on from 1985 to 1998, an homogeneous group of 124 consecutive patients with pathologic T1-T2 N1 disease who had undergone a complete resection with systematic nodal dissection were analysed. No patients received adjuvant radio- or chemotherapy. RESULTS: The overall 5-year survival rate was 48.8%. Survival was not related to pathologic T factor, histology, number, percentage or level of N1 involved, visceral pleura involvement, number of lymph nodes dissected. Patients were then divided into 3 groups depending on the level of lymph node involvement (stations 10, 11 and 12-13) and survival analysed according to the extent of resection (pneumonectomy vs lobectomy). No significant difference was found, however, in the group of level 10, patients treated by pneumonectomy showed a better 5-year survival (58%) compared to patients treated by lobectomy (33%) with a median survival of 110 against 58 months. This data was confirmed by a lower incidence of local recurrence in the pneumonectomy group than lobectomy group (0% vs 24%), whereas the same incidence of distant metastases was observed in the two groups (29% vs 23%). CONCLUSIONS: In patients with stage II (N1) NSCLC, only in case of station 10 involved, pneumonectomy could allow a better survival lowering the incidence of local recurrence. However the major part of patients with stage II (N1) NSCLC die for distant metastasis. This supports the necessity to develop a specific systemic treatment.

Which treatment in pericardial effusion?

BACKGROUND: Pericardiocentesis, pleuro-pericardial window, subxiphoid pericardial drainage and pericardioscopy: which methodology to treat pericardial effusion? Each of these surgical treatments can be effective, depending on clinical factors and history of the patients. We considered pericardial effusions during 5 years. METHODS: We reviewed 64 cases: 14 acute pericardial effusions (5 patients with cardiac tamponade), 39 subacute, 11 chronic. Epidemiology and aetiology: 8 cases were between 20 and 25 years old (all affected by lymphoma), 56 were distributed in every age, especially over 60, and of these 45 were neoplastic and 11 non- neoplastic. Non-neoplastic cases were connectivitis (3 patients), uncertain origin effusion (7 patients), tubercular (1 patient). In neoplastic effusions we found lymphoma (at older age) in 7, small cell lung cancer in 6, NSCLC in 12, mesothelioma in 2, breast cancer in 7. RESULTS: Acute pericardial effusions with cardiac tamponade underwent echo-guided pericardiocentesis. In 43 we had a subxiphoid pericardial drainage, among these cases we performed 4 pericardioscopies. We created a pleuro-pericardial window on VATS in 13, on thoracotomy in 4 for technical reasons. CONCLUSIONS: Pericardiocentesis is to be preferred in acute pericardial effusion with cardiac tamponade to avoid general anaesthesia. Pleuro-pericardial window on VATS is better in chronic pericardial effusion (for infective or systemic disease) and in recurrence, after performing subxiphoid drainage. Subxiphoid drainage is suitable for all neoplastic patients, and in case of unknown aetiology in order to perform a pericardioscopy.

Survival after bronchoplastic lobectomy for non small cell lung cancer compared with pneumonectomy according to nodal status.

BACKGROUND: In this retrospective study we have compared the results after sleeve lobectomy and pneumonectomy performed for non small cell lung cancer in the period January 1990-December 1995 at the Thoracic Surgery Unit, University Hospital of Siena. Follow-up was updated until December 2000. METHODS: In that period, 38 patients underwent sleeve lobectomy and 127 underwent pneumonectomy. The bronchoplasty was a full sleeve in 30 patients and a bronchial wedge resection in eight. Systemic nodal dissection was undertaken routinely. RESULTS: The 30-day postoperative mortality was 5.2% (2/38) in the sleeve lobectomy group and 3.9% (5/127) in the pneumonectomy group. Postoperative complications occurred in 23.6% of patients in the sleeve lobectomy group and in 23.2% of those in the pneumonectomy group. Local recurrences occurred in 5.2% of patients in the sleeve lobectomy group and in 4.8% of those in the pneumonectomy group. The overall 5-year survival for the sleeve lobectomy group was 38% whereas that for the pneumonectomy group was 25% (p=0.03). Regarding lymph-node involvement, in the sleeve lobectomy group, the 5-year survival for N0, N1 and N2 was 62.5, 17.5 and 12.5%, respectively. CONCLUSIONS: Our data confirm that sleeve lobectomy, when performed in selected patients with non small cell lung cancer, provides at least similar overall long term survival to that seen after pneumonectomy. Long term result are chiefly related to nodal stage with a significantly lower survival for patients with nodal involvement. As most patients with nodal involvement die from distant metastases, adjuvant treatment, instead of type of resection, would play a major role in prolonging survival.

Plasma thiols inhibit hemin-dependent oxidation of human low-density lipoprotein.

Oxidative modification of human low-density lipoprotein (LDL) renders it atherogenic. Previous studies demonstrated that plasma thiols promote oxidation of LDL by free ferric iron (Fe3+). The current study investigated effects of plasma thiols on oxidation of LDL by hemin, a physiological Fe3+-protoporphyrin IX complex thought to be capable of initiating LDL oxidation in vivo. In contrast to free Fe3+ which is incapable of oxidizing LDL in the absence of an exogenous reductant, hemin readily promoted LDL oxidation. During incubation of LDL (0.2 mg of protein/ml) with hemin (10 microM) at 37 degrees C for 6 h, thiobarbituric acid-reactive substances (TBARS), a marker of lipid oxidation, increased from 0.3 (+/-0.1) nmol/mg of LDL protein to a maximal concentration of 45.8 (+/-5.2) nmol/mg of LDL protein. Under the same experimental conditions, lipid-conjugated dienes, another marker of lipid oxidation, increased from non-detectable to near-maximal levels of 78-187 nmol/mg of LDL protein, and lipoprotein polyunsaturated fatty acyl-containing cholesteryl ester content decreased to 15-36% of that present in native (i.e. unoxidized) LDL. Continued incubation of LDL with hemin for up to 24 h resulted in no further significant alterations in lipoprotein levels of TBARS, lipid-conjugated dienes, and cholesteryl esters. In addition to these chemical modifications indicative of lipoprotein oxidation, agarose gel electrophoretic analysis indicated that exposure of LDL to hemin resulted in conversion of the lipoprotein to an atherogenic form as evidenced by its increased anodic electrophoretic mobility. Addition of physiological concentrations of plasma thiols (either cysteine, homocysteine or reduced glutathione; 1-100 microM, each) inhibited hemin-mediated oxidation of LDL. Thus, whereas the maximal TBARS concentration was achieved following 6 h of incubation of LDL with hemin alone, addition of thiol extended the time required to attain maximal TBARS concentration to > or = 12 h. Similar antioxidant effects of thiols on formation of lipid-conjugated dienes, loss of cholesteryl esters, and lipoprotein anodic electrophoretic mobility were also observed. However, all thiols were not equally effective at inhibiting hemin-dependent LDL oxidation. Thus, whereas reduced glutathione was most effective at inhibiting hemin-dependent LDL oxidation, an intermediate effect was observed for homocysteine, and cysteine was least effective. The inhibition of hemin-mediated LDL oxidation by plasma thiols reported here confirms a previous observation that, under certain conditions, thiols can function as antioxidants, but contrasts with the previously documented pro-oxidant effect of the same thiols on oxidation of LDL by free Fe3+. These contrasting effects of plasma thiols on hemin- and free Fe3+-mediated LDL oxidation indicate that, in vivo, the ability of thiols to function as either anti- or pro-oxidants during LDL oxidation may, at least in part, be determined by the type of oxidant stress to which the lipoprotein is exposed.

p53 transactivity during in vitro osteoblast differentiation in a rat osteosarcoma cell line.

We previously demonstrated a correlation between wild-type p53 expression and appearance of osteoblastic-specific differentiation characteristics, as evidenced by basal osteocalcin gene expression in a mouse osteosarcoma tumor. The study reported here further explored the possibility of p53's having a distinct transcription-activating role in bone differentiation, in addition to its proposed role in G1 arrest and apoptosis. ROS17/2.3 osteoblastic osteosarcoma cells were stably transfected with a plasmid containing wild-type p53 binding sequences fused to the chloramphenicol acetyltransferase reporter gene. These cells were used to determine the transactivating role of p53 in regulation of osteocalcin gene expression. We chose two conditions under which osteocalcin expression is known to be upregulated: exposure of osteoblastic cells to differentiation-promoting medium and to vitamin D3. Exposure of the transfected cells to differentiation-promoting medium produced an increase in p53 transactivating activity correlating with the appearance of osteocalcin expression after about 1 wk. Vitamin D3 treatment resulted in upregulation of osteocalcin activity without a corresponding change in p53 transactivation activity or expression. In separate experiments, we tested whether changes in osteocalcin expression accompanied changes in p53 activity under conditions of downregulation of cell proliferation mediated by inhibition of DNA synthesis. Hydroxyurea treatment was used to inhibit DNA synthesis and produce growth arrest in osteoblastic cells. Inhibition of osteoblast cell proliferation was associated with a fourfold increase in p53 transactivating activity and a transient increase in osteocalcin steady-state expression. These results demonstrated a close relationship between p53 and osteocalcin and suggested a regulatory role for wild-type p53 in the control of basal osteocalcin gene expression in osteoblasts.

Osmotic regulation of taurine transport via system beta and novel processes in mouse preimplantation conceptuses.

Taurine was shown recently to increase the frequency at which 2-cell mouse conceptuses develop into blastocysts in vitro. For this reason and because taurine helps cells adapt to external stresses, we studied transport of this and related amino acids by preimplantation mouse conceptuses. The most conspicuous component of taurine transport in conceptuses at the 1-cell through blastocyst stages of development was both Na(+)- and Cl(-)-dependent. This Na(+)- and Cl(-)-dependent transport system interacted relatively strongly with beta- but not alpha-amino acids. By these criteria, transport system beta is responsible for Na(+)-dependent taurine transport in preimplantation mouse conceptuses. Moreover, detection of mRNA encoding the taurine transport protein (TAUT) in early conceptuses supports the theory that TAUT is a major component of system beta. Transport of taurine by system beta in 1-cell conceptuses was slower in hypotonic than in hypertonic media, whereas the reverse was true for system beta in blastocysts. In contrast, hypotonically stimulated Na(+)-independent taurine transport was, of course, more rapid in hypotonic than in hypertonic media in both 1-cell conceptuses and blastocysts. Transport via this hypotonically stimulated process also showed no sign of saturation by up to 10 mM taurine. Hypotonically stimulated taurine transport appeared transiently in 1-cell conceptuses under hypotonic conditions until they had recovered their initial volumes. Hence, we suggest that a decrease in taurine uptake via system beta and an increase in taurine exodus via the Na(+)-independent, nonsaturable transport process could contribute to the regulatory volume decrease in 1-cell conceptuses in hypotonic medium. Since taurine uptake by system beta in blastocysts is, however, higher in hypotonic than in hypertonic media, taurine uptake by system beta in blastocysts might intensify a tendency to increase cell volume in hypotonic medium. Such an increase in taurine uptake could further favor anabolic changes associated with cell swelling. In addition to contributing to regulation of cellular volume and perhaps metabolism, the hypotonically stimulated Na(+)-independent transport processes in early embryos have novel characteristics. Hypotonically stimulated Na(+)-independent taurine transport was inhibited by niflumate, N-ethylmaleimide and NaN3 but not by furosemide, iodoacetate, KCN, ouabain or alpha- or beta-amino acids. Furthermore, 4,4'-diisothiocyanostilbene-2,2'-disulfonate inhibited this transport in 1-cell conceptuses but not in blastocysts. Hence, different hypotonically stimulated Na(+)-independent taurine transport processes appear to be present in 1-cell conceptuses vs. blastocysts. The functions of these and other instances of developmental regulation of expression of transport processes in preimplantation conceptuses remain largely to be elucidated.(ABSTRACT TRUNCATED AT 400 WORDS)

The cation receptor subsite of the choline transporter in preimplantation mouse conceptuses resembles a cation receptor subsite of several amino acid transporters.

Mediated choline transport in preimplantation mouse conceptuses was inhibited competitively by Na+ and other cationic osmolites. Uptake of choline by conceptuses was also inhibited relatively strongly by ethanolamine, hemicholinium-3, harmaline, harmalol and harmine. The Ki values for inhibition of choline transport by most of the latter inhibitors were of the same order of magnitude as the Km value for choline transport (approximately 100 microM). To our knowledge, we are the first to show that mediated 'Na(+)-independent' choline transport is, nevertheless, inhibited strongly by the Na(+)-site inhibitor, harmaline. Inhibitions by harmaline, Na+ and other cations have been used to draw a parallel between the substrate receptor sites of amino acid transport systems y+ and bo.+. We suggest that the latter parallel should be extended to include the Na(+)-independent mammalian choline transporter. In addition, the choline transport activity in conceptuses increased by more than 100-fold between the 2-cell and blastocyst stages of development. Mouse blastocysts probably utilize choline for the synthesis of membrane phospholipids during cellular differentiation and when they begin to grow about ten hours prior to implantation. Since we show here that mouse conceptuses develop the capacity to transport choline prior to the onset of growth, some of the choline utilized for growth could come from an exogenous source.