Precise U-Pb age constrains on the Ediacaran biota in Podolia, East European Platform, Ukraine.

The Neoproterozoic Era was characterized by rapidly changing paleogeography, global climate changes and especially by the rise and fall of the Ediacaran macro-biota. The correlation between disparate Ediacaran fossil-bearing localities and the tentative reconstruction of their paleoenvironmental and paleogeographic contexts are usually complicated by the lack of precise and accurate age data. For this reason, Neoproterozoic sedimentary sections associating Ediacaran biota fossils and fresh volcanic material are especially valuable for radioisotopic dating. Our research in the Podolya Basin, southwestern Ukraine, revealed the presence of four Neoproterozoic volcanic ash deposits (potassium-bentonite layers) within Ediacaran fossil-bearing siliciclastic rocks of the Mohyliv-Podilskyi Group. We used zircon U-Pb LA-ICPMS and CA-ID-TIMS methods to date two of those layers. The results indicate that a diverse assemblage of body and trace Ediacaran fossils occurred as early as 556.78 ± 0.18 million years (Ma) ago. By combining morphological evidence and new age determinations, we suggest a closer paleobiogeographical relationship between the Ukrainian Ediacaran assemblage and the Avalon paleocontinent than previously estimated.

A crystallographic study of crystalline casts and pseudomorphs from the 3.5†Ga Dresser Formation, Pilbara Craton (Australia).

Crystallography has a long history of providing knowledge and methods for applications in other disciplines. The identification of minerals using X-ray diffraction is one of the most important contributions of crystallography to earth sciences. However, when the crystal itself has been dissolved, replaced or deeply modified during the geological history of the rocks, diffraction information is not available. Instead, the morphology of the crystal cast provides the only crystallographic information on the original mineral phase and the environment of crystal growth. This article reports an investigation of crystal pseudomorphs and crystal casts found in a carbonate-chert facies from the 3.48 Ga-old Dresser Formation (Pilbara Craton, Australia), considered to host some of the oldest remnants of life. A combination of X-ray microtomography, energy-dispersive X-ray spectroscopy and crystallographic methods has been used to reveal the original phases of these Archean pseudomorphs. It is found with a high degree of confidence that the original crystals forming in Archean times were hollow aragonite, the high-temperature polymorphs of calcium carbonate, rather than other possible alternatives such as gypsum (CaSO4·2H20) and nahcolite (NaHCO3). The methodology used is described in detail.

Pasireotide treatment reduces cardiometabolic risk in Cushing's disease patients: an Italian, multicenter study.

PURPOSE: Patients with Cushing's disease (CD) experience metabolic alterations leading to increased cardiovascular mortality. Recently, the visceral adiposity index (VAI) has been proposed as a marker of visceral adipose tissue dysfunction (ATD) and of the related cardiometabolic risk. We aimed to evaluate the impact of 12-month pasireotide treatment on cardiometabolic risk in CD patients. METHODS: This is a multicentre, prospective, and observational study. Sixteen CD patients, referred to the Endocrine Units of the University Hospitals of Messina, Napoli, Padova, and Palermo (Italy), successfully treated with pasireotide for 12 month have been enrolled. In all patients, we assessed anthropometric, clinical, and biochemical parameters and calculated VAI, ATD severity, Framingham, and atherosclerotic cardiovascular disease (ASCVD) risk scores, before and after 6 and 12 months of treatment with pasireotide (1200-1800 mcg/daily). RESULTS: Before starting pasireotide treatment, ATD was present in 7/16 patients (mild in 2/16, moderate in 3/16, and severe 2/16). After 12 months of treatment: (i) 24h-urinary free cortisol levels (p = 0.003), BMI (p < 0.001), waist circumference (p = 0.001), LDL-cholesterol (p = 0.033), total-cholesterol (p = 0.032), triglycerides (p = 0.030), VAI (p = 0.015), and ATD severity (p = 0.026) were significantly decreased as compared to baseline; (ii) ATD was present in only 1/16 patients; (iii) prevalence of diabetes mellitus (p = 0.015) and HbA1c levels (p = 0.001) were significantly increased as compared to baseline; (iv) Framingham and ASCVD risk scores were not significantly different from pre-treatment values. CONCLUSIONS: Twelve-month pasireotide treatment significantly reduces VAI and ATD in CD patients. These positive effects on cardiometabolic risk occur despite no change in Framingham and ASCVD risk scores and the increase in the prevalence of diabetes mellitus.

Clinical management of critically ill patients with Cushing's disease due to ACTH-secreting pituitary macroadenomas: effectiveness of presurgical treatment with pasireotide.

The management of critically ill Cushing's disease (CD) patients is extremely challenging. Pasireotide is indicated for the treatment of CD patients when pituitary surgery is unfeasible or has not been curative, but no data are available about the use of this drug as pre-operative treatment in critically ill patients. We report the effects of presurgical pasireotide therapy in CD patients in whom hypercortisolism caused life-threatening hypokalemia, alkalosis, and cardio-respiratory complications precluding surgical approach. Clinical, biochemical, and radiological data of two critically ill patients with ACTH-secreting pituitary macroadenoma, before and during first-line presurgical pasireotide treatment (600 µg s.c. bid). During the first 21 days of treatment, pasireotide therapy induced a rapid, partial decrease of plasma ACTH, serum cortisol, and urinary free cortisol levels, with the consequent normalization of serum potassium concentration and arterial blood gases parameters, in both the patients. They did not experience unmanageable side effects and underwent endoscopic transsphenoidal surgery after 4 weeks of effective treatment. Pre-operative MRI evaluation did not show pituitary tumor shrinkage. Surgical cure of CD was obtained in the first patient, while debulking allowed the pharmacological control of hypercortisolism in the second case. We suggest that pasireotide can induce a rapid improvement of clinical and metabolic conditions in critically ill CD patients in whom surgical approach is considered hazardous and need to be delayed.

Increased frequency of the rs2066853 variant of aryl hydrocarbon receptor gene in patients with acromegaly.

CONTEXT: Aryl hydrocarbon receptor (AHR) pathway has a key role in cellular detoxification mechanisms and seems implicated in tumorigenesis. Moreover, polymorphisms and mutations of AHR gene have been associated with several human and animal tumours. Although AHR has been found differently expressed in pituitary adenomas, AHR gene mutation status has never been investigated in acromegalic patients. DESIGN: In this study, we evaluated patients with apparently sporadic GH-secreting pituitary adenoma for AHR gene variants. PATIENTS AND METHODS: Seventy patients with sporadic GH-secreting pituitary adenoma (M = 27, age 59.1 ± 1.6 years) and 157 sex- and age-matched controls were enrolled in the study. In all patients and controls, the exons 1, 2, 3, 5 and 10 of AHR gene were evaluated for nucleotide variants by sequencing analysis. RESULTS: The rs2066853 polymorphism was identified in the exon 10 of 18/70 acromegalic patients and 9/157 healthy subjects (25.7 vs. 5.7%, χ(2) = 18.98 P < 0.0001), in homozygosis in one patient and in heterozygosis in the other 17 and in the 9 healthy subjects. Moreover, a heterozygous rs4986826 variant in exon 10 was identified in a patient with heterozygous rs2066853 polymorphism, and in the patient with homozygous rs2066853 variant. This second polymorphism was not detected in the control group. Patients with rs2066853 polymorphism showed increased IGF-1 ULN (P < 0.05) and prevalence of cavernous sinus invasion (P = 0.05), thyroid (P = 0.02), bladder (P = 0.0001) or lymphohematopoietic (P < 0.05) tumours. CONCLUSIONS: AHR gene rs2066853 polymorphism is significantly more frequent in acromegalic patients than in healthy subjects and is associated with increased disease aggressivity. Moreover, the rs4986826 variant was detected in few patients with rs2066853 polymorphism, but its role is to be cleared.

Laparoscopic transduodenal papillosphincteroplasty.

In the past 20 years, the approach to biliary lithiasis has changed tremendously as a result of advances in endoscopic and laparoscopic techniques. The two most important open surgical techniques involve extraction of the stones from the common bile duct combined with choledochoenterostomy and papillotomy followed by transduodenal papillosphinteroplasty. Ideally, the choledochotomy is followed by the insertion of a T-tube in the common bile duct. The transcystic approach has never been considered. The first endoscopic papillotomy was performed in 1973. Subsequently, it became the most widely used method for removal of common bile duct stones. In this report we explore the possibility of performing a laparoscopic transduodenal papillosphincteroplasty, following the strict rules commonly used in surgery. After cholecystectomy, a Fogarty catheter, is introduced through the cystic duct. This is followed by a minimal duodenotomy, then incision of the papillar sphincter. In this surgical proposal, we do not intend to substitute technique, but this method should be considered the ultimate solution in the laparoscopic approach to cholecystic choledocholithiasis.

[Fast track in abdominal aortic surgery]. / Fast track in chirurgia dellaorta addominale.

BACKGROUND: The aim of this work is to evaluate the efficacy of a new perioperative approach to improve the outcome and to reduce hospitalisation after abdominal aortic surgery. EXPERIMENTAL DESIGN: observational study on patients operated from October 1996 to October 1997 (Group 1996), and from November 1997 to November 1998 (group 1998). CENTRE: Anaesthesiology Department of Regional Hospital. PATIENTS: historical group: 56 patients surgically treated with abdominal aortic bypass in 1996. CASE CONTROL GROUP: 58 patients surgically treated with abdominal aortic bypass in 1998. INTERVENTION: group 1996: maintenance of anaesthesia with forane and fentanyl; postoperative infusion of mepivacaine 1% through lumbar epidural catheter. GROUP 1998: preoperative anaesthesia through thoracic (T 4) epidural catheter with infusion of bupivacaine 0.5%; maintenance of anaesthesia with propofol, fentanyl and infusion of bupivacaine 0.125%; postoperative infusion of bupivacaine 0.125%, early rehabilitation care (early removal of nasogastric tube and urinary catheter, early deambulation, feeding and physiotherapy). EVALUATION: analgesia efficacy, day of deambulation, day of removal of the urinary catheter and the nasogastric tube, day of bowel canalization, day of discharge, major complications. RESULTS: In group 1998 analgesia was better. Furthermore a significant improvement consisted in the earlier removal of the nasogastric tube and the urinary catheter, earlier return of the gastrointestinal function and earlier deambulation. The length of stay is significantly reduced. In group 1998 we have less complications. CONCLUSIONS: Total intra-venous anaesthesia associated with a thoracic epidural anaesthesia, connected with early rehabilitation may improve the outcome and reduce the length of stay in patients submitted to abdominal aortic surgery.

Regional anaesthesia in vascular surgery: a multidisciplinary approach to accelerate recovery and postoperative discharge.

A multimodal, rehabilitative, fast discharge approach to abdominal aortic surgery is analyzed. The approach was developed in two phases during the years 1997-2000: in the first phase (1997) patients had thoracic epidural anesthesia plus TIVA and analgesia. They had improvement of the classical surrogate outcomes and analgesia: pain relief, nasogastric tube withdrawal, mobilization, ileus, hospital length of stay were significantly (p< 0,01) improved when compared to a historical, standard management group (1996: general anesthesia or lumbar epidural anesthesia plus general anesthesia with gas). In the second phase we started a more aggressive perioperative approach based on thoracic epidural anesthesia plus general anesthesia with gas and spontaneous breathing and postoperative epidural analgesia, left subcostal minilaparotomy incisions, aggressive postoperative nursing and pain relief on the ward. Preliminary results on 44 patients show no mortality, low postoperative morbility (cardiac complications 2,2%, peripheral embolization 2,2%, no pulmonary complications), no ICU stay and fast hospital discharge (median: 3,5 days, range: 2-8 days) without complications. We conclude that preliminary data support the safety and the need for further improvement of a multimodal, aggressive rehabilitative approach in abdominal vascular surgery.

[The effect on breastfeeding rate of regional anesthesia technique for cesarean and vaginal childbirth]. / Influenza sulla frequenza di allattamento al seno delle tecniche di anestesia regionale nel parto cesareo e nel parto per via vaginale.

BACKGROUND: To evaluate the influence of regional techniques of anesthesia and analgesia on breastfeeding rate after cesarean section and vaginal delivery. STUDY DESIGN: prospective, area-based. SETTING: Obstetrics and Pediatrics Department at Aosta Valley Regional Hospital. SUBJECTS: all the mothers and their newborns during a three-year period (1993-1995). Maternal wish to breastfeed was the main inclusion criterion. Data recorded: feeding modality at discharge, anesthesia and analgesia modality, maternal/neonatal socio-demographic and clinical data. RESULTS: 2725 records were examined, among them 1920 vaginal deliveries and 355 cesarean sections were statistically analyzed. chi 2 analysis showed a significant greater incidence of breastfeeding after cesarean section under regional anesthesia (spinal or epidural) versus general anesthesia: 95% vs 85.5%, p = 0.002. Breastfeeding rate was not different after vaginal delivery with epidural analgesia versus delivery without analgesia: 96.5% vs 97.8%. Logistic regression confirmed the positive role of regional anesthesia and few other maternal and neonatal variables on breastfeeding rate after cesarean section. CONCLUSIONS: Regional anesthesia seems to be advantageous for breastfeeding after cesarean section, probably because of a faster neonatal-maternal bonding if compared with general anesthesia. Epidural analgesia for vaginal delivery does not adversely affects breastfeeding if compared with delivery without analgesia.

Lumbar dura mater biomechanics: experimental characterization and scanning electron microscopy observations.

UNLABELLED: There is no consensus about the anatomical structure of human dura mater. In particular, the orientation of collagen fibers, which are responsible for biomechanical behavior, is still controversial. The aim of this work was to evaluate the mechanical properties and the microstructure of the lumbar dura mater. We performed experimental mechanical characterization in longitudinal and circumferential directions and a scanning electron microscopy observation of the tissue. Specimens of human dura mater were removed from the dorsal-lumbar region (T12-L4/L5) of six subjects at autopsy; specimens of bovine dorsal-lumbar dura mater were obtained from two animals at slaughter. Human and bovine tissues both exhibited stronger tensile strength and stiffness in the longitudinal than in the circumferential direction. Scanning electron microscopy observations of dura mater showed that the collagen fibers are mainly oriented in a longitudinal direction, which accounts for its stronger tensile strength in this direction. We conclude that dura mater has a different mechanical response in the two directions investigated because the fiber orientation is predominantly longitudinal. IMPLICATIONS: In this experimental work, we studied the structural and functional relationship of human lumbar dura mater. We performed mechanical tests and microscopic observations on dura mater samples. The results show that the dura mater is mainly composed of longitudinally oriented collagen fibers, which account for higher tissue resistance in this direction.

[Peridural anesthesia versus subarachnoid anesthesia in cesarean section. Prospective clinical study]. / Anestesia peridurale versus anestesia subaracnoidea nel parto cesareo. Studio clinico prospettico.

OBJECTIVE: To compare technical and clinical differences between epidural and spinal anesthesia for cesarean section. STUDY DESIGN: Randomized prospective trial. PATIENTS AND METHODS: 64 pregnant women at term scheduled for elective cesarean section. Two groups were randomized: A) PD Group (n = 32): continuous epidural anesthesia by administration of bupivacaine 0.5% plus epinephrine 1/400,000 via an epidural catheter. Epidural morphine 3 mg was administered at the end of surgery. B) SP Group (n = 32): "single shot" spinal anesthesia by intrathecal administration of hyperbaric 1% bupivacaine 1-1.4 ml plus morphine 0.2 mg. The pin prick block level reached T2-T6 at incision time. DATA COLLECTION: 1) Time from the beginning of anesthesia to surgical incision. 2) Hypotension episodes. 3) Ephedrine consumption. 4) Intraoperative discomfort at delivery, traction and uterine manipulation, peritoneal toilette. 5) Nausea and vomiting. 6) Apgar score. 7) Postoperative headache. RESULTS: Women in the SP group had more hypotensive episodes (81% vs 53%: p < 0.05) and more ephedrine consumption with a large individual variability (29.12 mg +/- 20.4 vs 12.83 +/- 13.8: p < 0.01) when compared to PD group, without any difference in the Apgar score. The SP group required less time consumption (10.5 min. +/- 6.7 vs 35.9 min. +/- 17.3: p < 0.01) and had less intraoperative discomfort with less analgesic and/or sedative drugs consumption (9.7% vs 29%: p < 0.05) and less vomiting (3% vs 22.5%: p < 0.05). No postoperative headache was noticed in both groups. CONCLUSIONS: With the described pharmacological and technical approach, spinal anesthesia is more suitable than continuous epidural technique for cesarean section, unless contraindicated.

Spinal anesthesia using hyperbaric 0.75% versus hyperbaric 1% bupivacaine for cesarean section.

UNLABELLED: Although 0.75% hyperbaric bupivacaine is commonly administered to provide spinal anesthesia for cesarean section in the United States, in some countries, only the 1% hyperbaric solution of spinal bupivacaine is available. The aim of this study was to compare 0.75% with 1% hyperbaric spinal bupivacaine for cesarean section. In this prospective study, 50 patients undergoing elective cesarean section were randomized to receive a spinal anesthetic with either 1.5 mL of 0.75% bupivacaine (n = 25) or 1.125 mL of 1% bupivacaine (n = 25). There were no statistically significant differences in patient demographics, time to onset of block, or intraoperative pain. All patients had a successful block for surgery. The time from injection of the spinal anesthetic to first request for pain medication in the postanesthesia care unit was longer in the women who received 0.75% bupivacaine (4.3 vs 3 h; P < 0.05). Six women (24%) who received 1% bupivacaine versus one woman (4%) who received 0.75% bupivacaine complained of postoperative backache (P < 0.05). In addition, postdural puncture headache occurred in four women, all of whom received 1% bupivacaine (P = 0.04). In conclusion, our data suggest that 0.75% bupivacaine results in fewer postoperative problems and offers several significant benefits compared with the 1% concentration. IMPLICATIONS: Although 0.75% bupivacaine is usually used to provide spinal anesthesia for cesarean section in the United States, a more concentrated solution is popular in Europe. In this study, we compared 0.75% bupivacaine with 1% bupivacaine when administered for cesarean section and found that the 0.75% solution offers several significant benefits.

Magnetic resonance (MR) imaging and MR spectroscopy of nerve regeneration and target muscle energy metabolism in a model of prosthesis-guided reinnervation in rats.

RATIONALE AND OBJECTIVES: We monitored the regeneration of the rat sciatic nerve after its transection and the concomitant alteration in the high-energy phosphates content in the target tibialis anterior muscle. METHODS: Rat sciatic nerve was resected and the gap connected with a prosthesis of polytetrafluoroethylene. Progress of reinnervation was monitored by 1H MR imaging, whereas muscular energy metabolism was evaluated by localized 31P MR spectroscopy. RESULTS: Reconstitution between the nerve stumps was resumed 8-12 weeks postoperatively. The ratio of phosphocreatine to inorganic phosphate reached a plateau at 46% of the initial level approximately 8 weeks after the operation and recovered thereafter. Immediately after the surgery, muscular pH became slightly alkaline and returned to normal with the progress of reinnervation. CONCLUSION: Recovery of the muscular energy metabolism began after the reconnection of the severed nerve stumps. The combination of MR imaging and MR spectroscopy followed noninvasively the progress of reinnervation and muscular energy metabolism of the prosthesis-guided nerve regeneration.