Age and origin of carlsbad cavern and related caves from 40Ar/39Ar of alunite

40Ar/39Ar dating of fine-grained alunite that formed during cave genesis provides ages of formation for the Big Room level of Carlsbad Cavern [4.0 to 3.9 million years ago (Ma)], the upper level of Lechuguilla Cave (6.0 to 5.7 Ma), and three other hypogene caves (11.3 to 6.0 Ma) in the Guadalupe Mountains of New Mexico. Alunite ages increase and are strongly correlative with cave elevations, which indicates an 1100-meter decline in the water table, apparently related to tectonic uplift and tilting, from 11.3 Ma to the present. 40Ar/39Ar dating studies of the hypogene caves have the potential to help resolve late Cenozoic climatic, speleologic, and tectonic questions.     

Absorption, uptake and tissue affinity of high-molecular-weight hyaluronan after oral administration in rats and dogs

The purpose of this study was to determine the absorption, distribution and excretion of (99m)technetium-labeled, high-molecular-weight hyaluronan (((99m)Tc-HA) and (99m)technetium pertechnetate ((99m)Tc-P) after single dose, oral administration to Wistar rats and Beagle dogs. A pilot study utilized (99m)Tc-HA alone, and a second confirmatory study compared uptake of labeled (99m)Tc-HA with (99m)Tc-P. Urinary and fecal excretion after (99m)Tc-HA ingestion by rats showed 86.7-95.6% of radioactivity was recovered, almost all in feces. All tissues examined showed incorporation of radioactivity from (99m)Tc-HA starting at 15 min and persisting for 48 h, in a pattern significantly different from (99m)Tc-P. Whole-body scintigraphs and close-ups of the ventral chest region showed nonalimentary radioactivity from (99m)Tc-HA concentrated in joints, vertebrae and salivary glands four hours after administration. Autoradiography of skin, bone and joint tissue pieces after 24 h showed incorporation of radioactivity from (99m)Tc-HA, but not from (99m)Tc-P. Conversely, absorption, distribution and excretion of (99m)Tc was completely different from (99m)Tc-HA, showing an expected pattern of rapid absorption and excretion in urine, with accumulation in thyroid glands, stomach, kidney and bladder. This report presents the first evidence for uptake and distribution to connective tissues of orally administered, high-molecular-weight HA.     

Comparison of 5 Surgical Techniques for Partial Liver Lobectomy in the Dog for Intraoperative Blood Loss and Surgical Time

Objective: To compare surgical time and intraoperative blood loss for 5 partial liver lobectomy techniques in the dog. Study Design: Experimental in vivo study. Animals: Dogs (n=10). Methods: Five surgical techniques (SurgiTie^?; LigaSure^?; Ultracision^® Harmonic Scalpel [UAS]; Suction+Clip; Suction+thoracoabdominal stapler [TA]) for partial liver lobectomy in dogs were evaluated and compared for total surgical time and intraoperative blood loss. Body weight, activated clotting time (ACT), heart rate, and intraoperative blood pressure (BP) were recorded. Blood loss was determined by adding the weight of the blood soaked sponges during surgery (1 g=1 mL) to the amount of suctioned blood (mL). Surgical time (in seconds) was determined from the start of the lobectomy until cessation of bleeding from the stump. Mean surgical time and mean blood loss for each technique were compared using a Tukey's multiple comparison test. Results: No significant differences were found between dogs for weight, ACT, heart rate, and intraoperative BP. No complications were seen with the SurgiTie^? technique in 9 of 10 cases. There was no significant difference in surgical time between techniques however there was a significant difference for blood loss; the Suction+Clip method had significantly more blood loss than the other techniques. Conclusions: Skeletonization of the lobar vessels before individually clipping them (Suction+Clip) resulted in a higher blood loss than using Suction+TA, UAS, SurgiTie^? or the LigaSure^? device. The SurgiTie^? appears to be an acceptable method for partial liver lobectomy. Clinical Relevance: Although skeletonization and individually clipping the vessels had the highest blood loss, it still was <7.5% of total blood volume. All 5 techniques should be safe for clinical use in small to medium sized dogs up to 26 kg.     

New Isocoumarin Analogues from the Marine-Derived Fungus Paraphoma sp. CUGBMF180003

Nine new secondary metabolites, including six isocoumarin analogues, 7-hydroxyoospolactone (1), 7-methoxyoospolactone (2), 7-methoxy-9-hydroxyoospolactone (3), 10-acetoxy-9-hydroxyoospolactone (4), 6-dehydroxysescandelin (5), parapholactone (6), and three compounds with a rare skeleton of isocoumarin coupled with phenylethylamine, namely paraphamide A (12), paraphamide B (13), and paraphamide C (14), together with five known compounds, oospolactone (7), 8-O-methyloospolactone (8), 10-hydroxyoospolactone (9), 9,10-dihydroxyoospolactone (10), and oospoglycol (11), were isolated and identified from the marine-derived fungus Paraphoma sp. CUGBMF180003. Their chemical structures were determined using spectroscopic data, including HRESIMS and 1D and 2D NMR techniques. Furthermore, the stereogenic carbons in 5 and 14 were determined by comparing the experimental and calculated electronic circular dichroism (ECD) spectra. The carbon skeleton of 12–14 was identified as the first example of isocoumarin coupled with phenylethylamine derivatives. All of these compounds were examined for antimicrobial activities against Candida albicans and Staphylococcus aureus. Both 1 and 6 showed antibacterial activity against S. aureus with MIC values of 12.5 μg/mL.     

The influence of a novel organ perfusion solution on early graft function in canine renal autotransplantation

Objective— To evaluate the influence of a kidney perfusion solution on early graft function in dogs.
Study Design— Experimental, randomized study.
Animals— Intact adult male mongrel dogs (n=12).
Methods— Dogs had renal autograft transplantation without ureteroneocystotomy with contralateral nephrectomy. Kidney graft flushing with a novel organ perfusion solution was compared with flushing with saline (0.9% NaCl) solution. Serum creatinine (Cr) and blood urea nitrogen (BUN) concentrations were measured daily posttransplant for 7 days. Ultrasound-guided renal biopsy was performed on postoperative day 1 for electron microscopic evaluation. Dogs were euthanatized on day 7.
Results— All dogs completed the study. Cr and BUN concentrations of the saline group were significantly greater than the organ perfusion solution group on each postoperative day ( P =.01 for S Cr; P =.001 for BUN). Electron micrographs of nuclei and mitochondria from convoluted proximal tubule cells indicated profound ultrastructural disruptions in the saline group and mild ultrastructural disruptions in the organ perfusion solution group.
Conclusion— Flushing solution composition can influence early graft function in live donor kidney transplantation.
Clinical Relevance— Use of a specialized flushing solution can improve early graft function in canine kidney transplantation, independent of antigen-mediated events.