The gravity field and interior structure of Enceladus.

The small and active Saturnian moon Enceladus is one of the primary targets of the Cassini mission. We determined the quadrupole gravity field of Enceladus and its hemispherical asymmetry using Doppler data from three spacecraft flybys. Our results indicate the presence of a negative mass anomaly in the south-polar region, largely compensated by a positive subsurface anomaly compatible with the presence of a regional subsurface sea at depths of 30 to 40 kilometers and extending up to south latitudes of about 50°. The estimated values for the largest quadrupole harmonic coefficients (10(6)J2 = 5435.2 ± 34.9, 10(6)C22 = 1549.8 ± 15.6, 1σ) and their ratio (J2/C22 = 3.51 ± 0.05) indicate that the body deviates mildly from hydrostatic equilibrium. The moment of inertia is around 0.335MR(2), where M is the mass and R is the radius, suggesting a differentiated body with a low-density core.

Leptin influences histidine dipeptides and nitric oxide release from anterior pituitary cells of sheep in vitro.

Our previous results show that leptin, as well as nitric oxide (NO) and some antioxidants (histidine dipeptides - HDP) change the secretion of gonadotrophins from ovine adenohypophysis cells in vitro. NO and HDP are produced by pituitary and can modulate gonadotropin secretion by autocrine action. It is possible that these compounds mediate leptin influence on gonadotropin secretion. Therefore, the objective of the present study was to analyse leptin effect on NO and HDP (3-metyl-L-histidine, carnosine and anserine) release from ovine pituitary in vitro. Adenohypophysis cells were cultured in McCoy 5A medium with GnRH (4 x 10(-9) M) and 10(-10)-10(-5) M/l of leptin, respectively. Next, the media for analysis of NO (Griess method) and HDP (HPLC) were collected. Leptin in concentration of 10(-8)-10(-6) M/l caused a significant augmentation in NO in the culture medium, whereas in the dose of 10(-5) M/l reduced (P< or =0.05) NO release. The level of 3-metyl-L-histidine and anserine, but not carnosine, was significantly lower in the culture with 10(-8)-10(-7) M/l of leptin. Taking into account that 10(-8)-10(-7) M/l leptin stimulates LH and FSH secretion, as show in our previous study, it is possible that this effect in ewes is mediated by augmented release of NO and reduction of HDP level.

Concentrations of carnosine, anserine, L-histidine and 3-methyl histidine in boar spermatozoa and sheep milk by a modified HPLC method.

The present study deals with the application of high-performance-liquid-chromatography (HPLC) method for a quantitative detection of carnosine, anserine, L-histidine and 3-methyl-L-histidine in biological material with o-phthaldialdehyde (OPA) post column derivatisation at the constant temperature of 50 degrees C. For this purpose, some mobile-phases were prepared with scalar acetonitrile concentrations. A complete separation of all molecules, particularly for carnosine and 3-methyl-L-histidine, was obtained with a solution of acetonitrile and 6mM hydrochloric acid with 0.48 M sodium chloride (5%:95% v/v). Post column derivatisation reaction at temperature of 50'C permitted to obtain an increase in sensibility of all molecules. This method has been utilised for detection of histidine dipeptides in boar spermatozoa and in sheep milk. Concentrations (mean +/- S.E. nmol/10(9) spermatozoa) of carnosine (0.96 +/- 0.14) and anserine (0.83 +/- 0.18) in boar spermatozoa were significantly lower than those of L-histidine (52.85 +/- 4.86) and 3-methyl-L-histidine (83.07 +/- 7.1). Positive correlation was found between carnosine and anserine contents (r = 0.740; p < 0.01) and between L-histidine and 3-methyl-L-histidine (r = 0.657; p < 0.01). All histidine dipeptides studied were also present in 40 samples of sheep milk. In a case of samples without unit-forming colonies (UFC) of Staphylococcus coagulase-positive, carnosine concentrations (9.17 +/- 0.89 nmol/ml) were higher than anserine (0.51 +/- 0.02 nmol/ml) and both were significantly lower in respect to L-histidine (49.51 +/- 6.48 nmol/ml) and 3-metyl-L-histidine (81.21 +/- 6.82 nmol/ml). A negative correlation was observed between carnosine milk levels (r = -0.773; p < 0.01) and UFC/ml of Staphylococcus coagulase-positive. In conclusion this very simple and fast method can be used to detect histidine dipeptides in biological compartments where their concentrations are very low.

Influence of training on plasma adrenaline and noradrenaline kinetics in untrained standardbreds.

REASONS FOR PERFORMING STUDY: Catecholamines (CAT) play an important role in modulating the response to exercise. But the kinetics of CAT changes during exercise are difficult to study due to their short biological half-life. OBJECTIVES: Learning about variations in plasma CAT levels during training could furnish new information regarding sweating, redistribution of blood flow and energy metabolism. METHODS: Four untrained Standardbreds, adapted to treadmill work, were used to determine the influence of training on plasma adrenaline (A) and noradrenaline (NA) kinetics. Horses underwent a standardised exercise test (SET) on treadmill before (SET1), and 1 (SET2) and 2 months after (SET3) the start of a moderate training period on treadmill. The SET procedure was: warm-up and a single step of 2 min at 200 beats/min heart rate (SS). The automatic blood collection system (that has been carried out during SS) and the preparation of the horses have been described previously. The system was programmed to obtain a blood sample every 15 sec (8 blood samples per SS). Analyses were performed by HPLC. Training progress was monitored by means of anaerobic threshold velocity (V4) and the velocity during SS (V200). Wilcoxon's test was used for statistical analysis. RESULTS: Decreased levels of A and NA with significant differences between SET1/SET2 and SET1/SET3 for A (P = 0.007) and NA (P = 0.007) were found. There were no differences between SET2 and SET3 for A (P = 0.195) and NA (P = 0.054). CONCLUSIONS: Training appears to influence the level of plasma CAT and this influence is greater during the first training period in untrained Standardbreds. POTENTIAL RELEVANCE: It may prove interesting to associate the study of training-induced modifications of the concentration of plasma CAT with thermoregulation, which is under catecholaminergic control and undergoes important adaptations during training.

[Mechanical microanastomosis in reconstructive surgery of the neck and face]. / Le microanastomosi meccaniche in chirurgia ricostruttiva del distretto cervico-facciale.

Aim of the study is to report our preliminar experience with MCA Coupler System in mechanical microanastomoses performed in head and neck reconstructive surgery. During almost 7 months we performed 7 end-to-end venous anastomoses: 3 of them regarding the cephalic district. We had no vascular thrombosis, vascular congestion or flap loss. Mean time of execution of anastomosis with MCA Coupler System was 10 minutes. In our experence it is essential the choice of the appropriate size of the device and a good dissection of recipient vessels. In our opinion the Coupler System is an easy applicable device, and an efficient alternative to manual micro-anastomoses.

Coenzyme Q10 levels in pigeon (Columba livia) spermatozoa.

AIM: To assess the CoQ10 levels in pigeon spermatozoa and to verify their possible correlation with spermatic kinetic parameters. METHODS: In pigeons the sperm motility percentage (MOT%), mean linear velocity (VCM) and morphology were determined in ejaculated semen. In addition intracellular CoQ10 concentrations were also detected with a HPLC method. RESULTS: Intracellular CoQ10 levels demonstrated wide individual variations, averaging 4.85 +/- 2.31 (SD) ng/106 spermatozoa. Statistical analysis showed a positive correlation of the substance with the sperm concentration (r= 0.63; P<0.05) and with the VCM (r=0.66; P<0.05), and a negative correlation with the MOT% (r = -0.78; P=0.01). No correlation was found between the CoQ10 concentration and the percentage of normal spermatozoa. CONCLUSION: Our results suggest a possible role for CoQ10 as a "fertility marker" in pigeons, which may be employed to monitor the pharmacological effects of cytostatic substances often used to reduce the pigeon fertility in urban environment.

Papillary thyroid carcinoma metastatic to the parapharyngeal space.

Nodal metastases from head and neck primary cancer presenting as a parapharyngeal space mass are rare. This paper reports two cases of papillary thyroid carcinoma metastatic to the parapharyngeal space. This finding can be related to Rouviere's description of a direct lymphatic pathway from the posterior surface of the superior thyroid lobe to the lateral retropharyngeal nodes. Metastatic thyroid cancer should be considered in the differential diagnosis of a parapharyngeal space mass.

Assessment of trans, trans-muconic acid in human seminal plasma.

Trans, trans-muconic acid (tt-MA) is one of the most important metabolites of benzene, a pollutant ubiquitously distributed in ambient air and classified in 1982 as a group I carcinogen. For its sensitivity and specificity, tt-MA excreted in urine is considered a good biological marker of benzene exposure. In this study, seminal tt-MA levels in occupationally nonexposed subjects (n = 32) have been determined. The seminal fluid of normozoospermic subjects contained an average tt-MA concentration (170 +/- 100 ng ml-1) significantly lower than that of teratozoospermic (310 +/- 180 ng ml-1; P < 0.01), oligozoospermic (400 +/- 180 ng ml-1; P < 0.001), and oligoasthenozoospermic (430 +/- 230 ng ml-1; P < 0.01) subjects. A negative correlation existed between tt-MA levels and sperm concentration (r = - 0.62; P < 0.001), percentage of normal spermatozoa (r = - 0.41; P < 0.05), and percentage of vital spermatozoa (r = - 0.89; P < 0.001). Average tt-MA levels detected in seminal plasma were higher in smokers (350 +/- 160 ng ml-1) than in nonsmokers (280 +/- 210 ng ml-1). These results show that seminal plasma tt-MA content could be an important biological indicator for evaluating the negative effects of benzene on spermatogenesis.

Serum cytokeratins determination in differentiated thyroid carcinoma.

To assess the potential value of cytokeratins (CK) 8,18,19 as tumor markers for thyroid diseases, a study was performed comparing serum CK 8,18,19 levels in patients affected from thyroid carcinoma, adenoma, other benign thyroid diseases and healthy volunteers as controls. One hundred cases (65 patients and 35 controls) were examined. Thirty patients had thyroid carcinoma (18 papillary--PTC, 8 follicular--FTC, 4 medullary--MTC), 19 non-toxic goiter, 10 thyroid adenoma, 6 chronic thyroiditis and 35 healthy volunteers as controls. These controls were matched by age and sex. The mean value of CK in benign thyroid diseases (46.1 U/L) was significantly higher (p<0.02) than that in healthy controls (29.6 U/L). The mean value of CK in carcinomas (68.1 U/L) was significantly higher than that in healthy controls (p<0.01) and benign thyroid diseases patients (p<0.05). The positive rate of CK in thyroid carcinomas was 28.1%, while in benign thyroid diseases was 17.8%. The CK sensitivity for thyroid carcinomas was 28.1%, with a specificity of 80% and accuracy of 70.4%. In PTC patients the mean CK value was not significantly higher than in the benign diseases' group and in healthy subjects. No evident correlation between CK levels and tumor mass was found. In FTC patients the mean value was significantly higher than in the benign diseases' group and in healthy subjects. Large tumors showed the highest levels, while small tumor values were similar to the control ones. In MTC patients the mean value was significantly higher than in the benign diseases' group and in healthy subjects, with the highest peaks in large tumors and metastatic tumors. The detection of increased values in thyroid carcinomas with high metastatic potential (FTC and MTC) seems to confirm the role of these antigens in predicting the malignancy's degree of the neoplasm. These findings, if confirmed in larger series, could play an important role in assessing the CK 8,18,19 serum level as a real prognostic factor. Further repeated serum determinations after total thyroidectomy might indicate the role of CK 8,18,19 as serum markers predicting the risk of metastases.

The osteo-chondro-mucous flap of the nasal septum in orbital reconstruction.

This paper describes a technique for orbital infero-medial wall reconstruction after "en bloc" resection of squamous cell carcinomas involving ethmoidal and maxillary sinuses utilizing an osteo-chondro-mucous flap of the nasal septum. This technique seems to be superior for many reasons: rapidity in flap preparation, direct access to the donor area in the resection surgical field, reliabilty due to good vascular supply, major functional and aesthetic results (low risk of diplopia and eyeball displacement). In our opinion, among the orbital reconstruction techniques, the osteo-chondro-mucous flap of the nasal septum can be the preferred reconstructive choice in ethmoid-orbital-maxillectomy with excision of the whole medial and two thirds of the lower orbital walls.

[Free radial forearm flap and myocutaneous flaps in oncological reconstructive surgery of the oral cavity, Comparison of functional results]. / Il lembo libero radiale di avambraccio ed i lembi miocutanei nella chirurgia ricostruttiva oncologica del cavo orale. Implicazioni funzionali a confronto.

In modern multi-disciplinary cancer treatment, rehabilitation and functional results represent utmost intent in reconstructive surgery of the oral cavity. Even in cases where the stage of disease is advanced) and the perspective of survival is limited, it is possible to achieve an acceptable quality of life. The authors report, in this study, the morpho-functional results and the morbidity observed in glossectomies in which the reconstruction was performed using three different methods. In a total of 264 reconstructive flaps of the head and neck regions, the authors considered three groups of 15 patients that had had reconstruction after the demolitive procedure. Respectively these groups were divided by the followed methods: free forearm flap, pectoralis major myocutaneous flap and nasolabial flap. The morbidity showed an extremely low rate of flap loss in all the groups, but "minor" complications, such as fistulas and leakages, were significantly more frequent in the myocutaneous flaps group. Functional evaluation for speech and deglutition showed good results in most patients. Extremely severe postoperative conditions as a permanent NG tube or incomprehensible speech had been observed in less than 15% of the cases. Particularly, the pectoralis major flap, showed its best functional performances in the total or subtotal glossectomies with a sacrifice of the muscles of the oral floor. The free forearm flap is reliable and safe with its low thickness and pliability, especially for partial glossectomies. The nasolabial flap was confirmed to be the first reconstructive choice for selected limited resections of the tongue and of the antero-lateral floor. With this experience it is possible, even in more complex free flaps, to reduce the time consumption and the complication rate. Free flaps do not substitute routinely myocutaneous and conventional flaps, but they represent the "ideal" reconstructive alternatives for specific and selected indications.

Hyperfunctioning differentiated thyroid carcinoma.

A case of functioning plurifocal papillary carcinoma causing a clinical condition of hyperthyroidism is presented. Histologically, the carcinoma presented a dominant macrofocal nodule of an approximately 5 cm diameter, surrounded by chronic thyroiditis. Its occurrence in a patient under 20 years of age within a hot area in the thyroid bed and the lack of histological findings of hyperplastic tissue led the authors to consider this a rare case of hyperfunctioning differentiated thyroid carcinoma, and not a pure association of hyperthyroidism and carcinoma. Autonomously functioning thyroid nodules that are differentiated carcinomas are extremely rare with only 18 such cases reported in literature. While in the past it was commonly believed that a hot nodule is unlikely to be malignant, the possibility of an hyperfunctioning carcinoma should not be overlooked.

Neck dissection for surgical treatment of lymphnode metastasis in papillary thyroid carcinoma.

In papillary thyroid carcinoma lymphnode metastases at presentation do not seem to adversely affect survival, but do increase the risk of loco-regional tumor recurrence. The value of systematic versus selective lymphadenectomy is far less standardized, whereas the role of postoperative radioiodine in preventing either nodal recurrence or cancer death remains controversial. Clinical data of 36 N+ patients with papillary thyroid carcinoma who had undergone from 1990 to 1996 ipsilateral or bilateral neck dissection were retrospectively reviewed, to analyse the value of systematic lymphadenectomy. In our series of 50 extensive lymph node dissections (levels 2-6), the number of metastases in each specimen (mean value: 5) and the incidence of multiple level metastases (36%) were high. In 37.5% of the metastases at level 6 and in 11.1% at level 4, coexisting nodal involvement at level 2 was observed, without metastasization at intermediate levels. Multiple levels metastases and skip metastases were present in at least one third of the patients and could be excised only performing a complete dissection of the levels 2-6. Extra-capsular spread was found in 56% of the specimens. In 64.3% of these cases a functional neck dissection was performed. A modified radical or radical neck dissection was carried out in the other 35.7% of the cases. These patients received modified radical neck dissection (functional dissection with sacrifice of internal jugular vein) in 60% of the cases and radical neck dissection in the other 40%. In papillary thyroid carcinoma extensive lymphnode dissection at presentation has been stated to offer no advantage versus selective lymphadenectomy, causing increased morbidity. However, experienced surgeons report a low incidence (less than 5%) of accessory spinal nerve and cervical plexus permanent sequelae after functional neck dissection. In our opinion, patients with cervical lymph node metastases require a complete loco-regional neck dissection. Systematic lymphadenectomy, performed by lateral neck plus upper anterior mediastinal dissection, can yield a high disease-free survival. Moreover, this can limit the overall radio-iodine therapeutic dose and the risk of de-differentiation of recurrent tumor to the anaplastic type in patients with a long-term and near normal life-span.

[Multiple stage cervical laryngotracheal reconstruction after trauma with extensive tissue loss]. / La ricostruzione per stadi della laringe e della trachea cervicale dopo traumi con estesa perdita di sostanza.

Laryngotracheal reconstruction after trauma with extensive tissue loss is one of the most controversial issues in head and neck surgery today. The main goal is to provide a durable supportive framework over which endolaryngeal mucosa can regenerate. Although a variety of single-stage and multiple-stage reconstructive techniques are available, all have limitations. As there is no single universally applicable technique, it is necessary to know most of them and to realize the advantages and limitations of each procedure. On the basis of 18 years' experience we show the results from a series of 18 patients who underwent multiple-stage laryngotracheal reconstruction done with almost all available procedures (Laser surgery, Aubry technique, laryngotracheoplasty with cartilage grafting, subtotal laryngectomy, tracheal and laryngo-tracheal anastomosis, sternocleidomastoid myoperiosteal flap, composite hyoid sternohyoid muscle flap). Fourteen of the 18 patients were successfully decannulated. All of the mentioned procedures have been previously reported to be successful by their proponents, with variable complication rates. Subsequently, every case requires individual evaluation to determine which reconstructive technique is most appropriate for the patient's particular disease process.

[Differentiated carcinoma in autonomously functioning thyroid nodule: case report]. / Carcinoma differenziato in nodulo autonomo della tiroide: descrizione di un caso.

This paper report a case of autonomously functioning thyroid nodule, firstly occurred in a 13 years old women, complicated 9 years later by hyperthyroidism, with no response to thyreostatic treatment, hystologically diagnosed as papillary carcinoma, in a thyroid gland affected by Hashimoto's thyroiditis, with cervical bilateral lymph node metastasis. In literature the rate of coexisting hyperthyroidism, chronic thyroiditis and differentiated carcinoma is low; thus thyroid malignancies are very rare in young people. In this patient the large autonomously functioning nodule was entirely made of neoplastic tissue, while in the remaining thyroid there was no evidence of adenomatous tissue. Moreover, thyreostatic treatment failed in controlling hyperthyroidism. The Authors consider these facts as indirect evidences that this is a rare case of hyperfunctioning differentiated thyroid carcinoma.

[The rectus abdominis free flap in reconstructive surgery of the head and neck]. / Il lembo libero di muscolo retto addominale nella chirurgia ricostruttiva cervico-facciale.

The Authors describe their preliminary experience with rectus abdominis free flap in reconstructive surgery of the head and neck. Out of the 29 cases of microsurgery in treating head and neck tumours, four inferior rectus abdominis free tissue transfers were used: two for complex intraoral reconstruction and two for composite facial defects. There was one flap loss due to late infection in the region of anastomosis, while there were two complications in the remaining three cases. The morphological and functional results have proved to be highly satisfactory. The flap, based on the deep inferior epigastric vessels, appears to be versatile in terms of skin island design, thickness and length of the pedicle. As with the forearm free flap, the inferior rectus abdominis has the advantage of offering the possibility of simultaneous demolition and reconstruction in one surgical session. The Authors conclude that the low morbidity concerned with this microvascular flap, also reported in international literature, confirm its validity as a soft tissue transfer in the in the treatment of advanced head and neck cancer.

[Pressor, renal and endocrine effects of systemic infusion of L-arginine in hypertensive patients]. / Effetti pressori, renali ed endocrini dell'infusione sistemica di L-arginina in soggetti ipertesi.

In this study we compared the pressor, renal and endocrine effects of the physiological precursor of endothelial derived nitric oxide, L-arginine, with D-glucose, a substrate inactive on nitric oxide. Ten subjects with mild to moderate primary hypertension underwent infusion with either L-arginine (5 patients) or D-glucose (5 patients). The substances were infused over 25 min at equiosmolar rates, preceded and followed by a 25-min saline infusion. Blood pressure (BP) and heart rate were monitored at 3-min intervals; hormonal and humoral variables, inulin and para-aminohippurate clearance, and electrolyte excretion were measured at the end of each period at maximum diuresis. L-arginine and D-glucose brought about comparable increases in serum osmolality and similar hemodilution as compared with control saline. During L-arginine infusion, systolic and diastolic BP dropped by 16.6% and 11% respectively and recovered during the post-infusion period. Heart rate, plasma renin activity, and plasma norepinephrine did not change significantly. The percent BP decrease induced by L-arginine was significantly greater than that caused by D-glucose. Glomerular filtration rate remained stable, and renal plasma flow increased with both substances. However, only L-arginine stimulated markedly natriuresis, kaliuresis, and chloruresis. It also seemed to induce systemic acidosis, possibly as a consequence of hydrochloric acid generated during its metabolism. Circulating insulin, atrial natriuretic peptide, growth hormone, and glucagon levels increased, and plasma aldosterone remained unchanged during L-arginine infusion. During D-glucose infusion, insulin was stimulated and the other hormones were inhibited.(ABSTRACT TRUNCATED AT 250 WORDS)

Pressor, renal and endocrine effects of L-arginine in essential hypertensives.

The pressor, renal and endocrine effect of the physiological precursor of endothelial derived nitric oxide, L-arginine was compared, with a substrate inactive on nitric oxide, hypertonic D-glucose, in hypertensive patients. Ten mild-moderate essential hypertensives were assigned to either L-arginine (n = 5) or D-glucose (n = 5). Substances were infused over 25 min at equiosmolal rates preceded and followed by saline infusion for 25 min. Blood pressure and heart rate were monitored at 3-min intervals, while hormonal and humoral variables, inulin and paraaminohippurate clearance and electrolyte excretion were measured at the end of each period under conditions of maximal diuresis. L-arginine and D-glucose increased serum osmolality comparably and caused similar haemodilution to that with control saline. During L-arginine infusion, systolic and diastolic blood pressure decreased by 16.6% and 11%, respectively, and recovered in the postinfusion period. Heart rate, plasma renin activity, and plasma noradrenaline did not change significantly. The percent blood pressure decrement induced by L-arginine was significantly greater than that by D-glucose. Glomerular filtration rate was stable and renal plasma flow was increased by both substances. However, natriuresis, kaliuresis and chloruresis were markedly stimulated only by L-arginine, which also promoted the development of systemic acidosis, possibly as a consequence of hydrochloridric acid generated during its metabolism. Circulating insulin, atrial natriuretic peptide, growth hormone and glucagon levels were increased and plasma aldosterone was unchanged during infusion of L-arginine. Insulin was stimulated and the other hormones inhibited during infusion of D-glucose.(ABSTRACT TRUNCATED AT 250 WORDS)

[Total/near-total glossectomy for advanced carcinoma of the tongue]. / La glossectoma totale/subtotale nel trattamento dei tumori avanzati della lingua.

Poor survival rates and the limited palliation afforded by radiotherapy alone, together with progress made in reconstructive surgery in restoring mucosal continuity after large resections, make total glossectomy reasonably indicated for treatment of advanced carcinoma of the tongue. The Authors reviewed 19 cases (17 males, 2 females, mean age 58.4 years) of total and near total glossectomy without laryngectomy treated at National Cancer Institute "Regina Elena" of Rome from 1990 to 1993 in order to evaluate oncological and functional results. All patients were reconstructed immediately, 16 with a pectoralis major flap, 2 with a nasolabial flap and 1 with a radial forearm free flap and were available for follow-up from 6 to 45 months (mean 29 months). There was no operative mortality and no patient needed total laryngectomy for aspiration. The rate of local recurrencies was 52.6%, most of them (75%) in patients who had undergone total/near total glossectomy for recurrence. Survival rate was 61.5% after 1 year and 20% after 2 years. 94% of patients resumed swallowing and independent oral alimentation (48% of them without any dysphagia); 84%; of the patients were decannulated and 48% produced easily intellegible speech. Data from our experience let us conclude that, in the light of the acceptable functional results obtained with reconstructive flaps, total glossectomy should be considered as the primary treatment modality in advanced carcinoma of the tongue (including T2 > 3 cm exceeding midline), and should not be reserved only for salvaging hopeless situations.