Nutrient digestibility, rumen parameters, and (cannabinoid) residues in sheep fed a pelleted diet containing green hemp (Cannabis sativa L.) biomass.

The feeding value for ruminants of green hemp biomass, from the low Δ9-tetrahydrocannabinol (Δ9-THC) variety of Cannabis sativa L., is unknown. Twelve Merino ewes were individually penned and randomly allocated on a stratified liveweight basis to one of two pelleted dietary treatments, control (0% hemp, n = 6) or hemp (42% green hemp biomass, n = 6) that delivered a diet meeting the nutrient requirements of the animals. The experimental period consisted of 17 d dietary and housing adaptation, followed by 7 d total urine and feces collection for determination of apparent nutrient digestibility. A ruminal fluid sample was collected on day 27 and assessed for pH, ammonia, volatile fatty acid (VFA), and cannabinoid concentrations. A blood sample from the jugular vein and incisional subcutaneous fat biopsy from an area around the base of the tail were collected on day 28 with additional fat biopsies taken 35 d and 140 d post-feeding to measure cannabinoids. The dry matter (DM), organic matter (OM), and crude protein (CP) digestibilities, along with total VFA concentration did not differ (P = 0.713) between the two diets; however, acid detergent fiber (ADF) and neutral detergent fiber (NDF) digestibilities (P < 0.001), water intake (P = 0.023), and fecal water output (P < 0.001) were significantly lower for the sheep-fed Hemp. Rumen pH did not vary (P = 0.256) between diets, but ruminal ammonia concentration was significantly lower (P = 0.024) for sheep consuming Hemp. Sheep-fed Hemp had significantly greater molar proportions of butyric (P = 0.039) and hexanoic (P = 0.012) acids and lower molar proportions of propionic acid (P = 0.003). There were no differences between diets for N intake (P = 0.175), fecal N output (P = 0.253), and N balance (P = 0.695), with all sheep in positive N balance; however, there was significantly lower (P = 0.001) urinary N output for sheep-fed Hemp. Cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA) were detected in plasma of all sheep-fed Hemp. ∆9-tetrahydrocannabinol was present in the subcutaneous fat of four of the six sheep on the final day of being fed Hemp, and in all (six) sheep 35 d post-feeding and one sheep 140 d post-feeding Hemp. No cannabinoids were detected in the corresponding samples taken from the sheep-fed Control. Thus, despite green hemp biomass being nutritionally a suitable feed for ruminants, under current Food Standards in Australia, the presence of these cannabinoid residues restricts its use in ruminant diets.

Valproate and copper accelerate TRH-like peptide synthesis in male rat pancreas and reproductive tissues.

Treatment with valproate (Valp) facilitates the synthesis of TRH-like peptides (pGlu-X-Pro-NH(2)) in rat brain where "X" can be any amino acid residue. Because high levels of TRH-like peptides occur in the pancreas and pGlu-Glu-Pro-NH(2) (Glu-TRH) has been shown to be a fertilization promoting peptide, we hypothesized that these peptides mediate some of the metabolic and reproductive side effects of Valp. Male WKY rats were treated with Valp acutely (AC), chronically (CHR) or chronically followed by a 2 day withdrawal (WD). AC, CHR and WD treatments significantly altered TRH and/or TRH-like peptide levels in pancreas and reproductive tissues. Glu-TRH was the predominant TRH-like peptide in epididymis, consistent with its fertilization promoting activity. Glu-TRH levels in the epididymis increased 3-fold with AC Valp. Phe-TRH, the most abundant TRH-like peptide in the pancreas, increased 4-fold with AC Valp. Phe-TRH inhibits both basal and TRH-stimulated insulin release. Large dense core vesicles (LDCV's) contain a copper-dependent enzyme responsible for the post-translational processing of precursors of TRH and TRH-like peptides. Copper (500 microM) increased the in vitro C-terminal amidation of TRH-like peptides by 8- and 4-fold during 24 degrees C incubation of homogenates of pancreas and testis, respectively. Valp (7 microM) accelerated 3-fold the processing of TRH and TRH-like peptide precursors in pancreatic LDCV's incubated at 24 degrees C. We conclude that copper, an essential cofactor for TRH and TRH-like peptide biosynthesis that is chelated by Valp, mediates some of the metabolic and reproductive effects of Valp treatment via acceleration of intravesicular synthesis and altered release of these peptides.

Rapid modulation of TRH and TRH-like peptide levels in rat brain and peripheral tissues by corticosterone.

Disturbance of glucocorticoid signaling has been implicated in several neuropsychiatric disorders including unipolar and bipolar depression and anxiety induced by maternal deprivation. Antidepressants have been shown to be neuroprotective and able to reverse damage to glia and neurons. Thyrotropin-releasing hormone (TRH) is an endogenous antidepressant that reduces the expression of glycogen synthase kinase-3beta (GSK-3beta), an enzyme that hyperphosphorylates tau and is implicated in bipolar depression, diabetes and Alzheimer's disease. In order to understand the potential role of TRH and TRH-like peptides both as mediators of the depressogenic effects of glucocorticoids and as potential therapeutics for neuropsychiatric disease, 300 g male Sprague-Dawley rats were injected i.p. with 4 mg corticosterone/0.5 ml 50% DMSO+50% ethanol and sacrificed 0, 2, 4 and 8h later. Levels of TRH and TRH-like peptides were measured in various brain regions involved in mood regulation and pancreas and reproductive tissues that mediate the metabolic and reproductive impairments associated with high glucocorticoid levels. Significant increases, ranging from 2- to 12-fold, in TRH or TRH-like peptide levels were observed in almost all brain regions studied at 4h after corticosterone injection. In cerebellum, TRH and TRH-like peptides increased 4-14-fold by 8h. TRH-like peptide levels fell 86-98% at 4h after treatment in testis. TRH, derived only from Leydig cells, was not affected. TRH and TRH-like peptides increased 2-4-fold at 8h in pancreas. TRH and TRH-like peptide concentrations in prostate were not affected by corticosterone up to 8h after injection. The 4h needed to detect a highly significant change in the TRH and TRH-like peptide levels in brain and peripheral tissues is consistent with the mediation of most corticosterone-effects via alterations in gene transcription.

Mean pressures and flows in the human intracranial system as determined by mathematical simulations of a steady-state infusion test.

In order to understand the fluid dynamics within the human intracranial system, the relatively small flow of extracellular fluid into, and out of, the interstitial brain tissue must be determined. Due to the magnitude of these flows, it is difficult to measure them clinically. Through a steady-state infusion simulation run on a mathematical model, values for these small flows may be calculated based on clinical data regarding the conductance of cerebrospinal fluid outflow. In this way, the mathematical model allows information to be obtained regarding these small mean flows, as well as the remaining mean flows and mean pressures throughout the intracranial space, with minimal reliance on data from intrusive procedures.

Anonymous oocyte donation performed exclusively with embryos cryopreserved at the pronuclear stage.

OBJECTIVE: To evaluate the clinical outcomes of patients who participated in an anonymous oocyte donation program that used embryos cryopreserved at the pronuclear stage. DESIGN: Observational study. SETTING: A tertiary care reproductive medicine unit. PATIENT(S): Anonymous oocyte donors and their respective recipients. INTERVENTION(S): Oocyte donors underwent a standard controlled ovarian hyperstimulation protocol and transvaginal ultrasound-guided oocyte retrieval. Oocyte recipients underwent at least one programmed hormone replacement cycle with transcervical ET. MAIN OUTCOME MEASURE(S): Thaw survival, implantation, clinical and ongoing pregnancy rates. RESULT(S): Thirty-six oocyte retrievals resulted in one ET to date. The mean numbers of oocytes that were retrieved and normally fertilized were 18.2 and 11.6, respectively. Fifty-one embryo thaw-transfer cycles were performed, with an embryo thaw survival rate of 93.5%. The clinical and ongoing pregnancy rates per ET were 52.9% and 51%, respectively. The overall implantation rate was 28.7%. The percentage of oocyte retrievals that resulted in at least one ongoing pregnancy to date was 69.4%. CONCLUSION(S): Anonymous oocyte donation can be conducted efficiently with the exclusive use of embryos cryopreserved at the pronuclear stage. This approach facilitates synchronization of the donor-recipient pair, eliminates the risk that recipients will begin hormonal therapy without embryo availability, and produces an acceptable ongoing pregnancy rate per oocyte donation.

An evaluation of educational outreach to general practitioners as part of a statewide cervical screening program.

OBJECTIVES: The purpose of this study was to determine the acceptability, effectiveness, and cost of a face-to-face educational outreach intervention in the context of a program aimed at increasing cervical screening in Victoria, Australia. METHODS: All identified general practitioners in a specified intervention area were offered a visit by a general practitioner educator. Practitioners completed a questionnaire evaluating the acceptability of the visit. Odds ratios for a woman being screened in the 3 months following the visits were determined. RESULTS: Fifty-nine general practitioners (69.4%) accepted the offer of a visit. Most found both the process and the content of the intervention to be acceptable. The intervention and nonintervention regions did not differ either before or after the intervention. In both regions, there was a statistically significant increase in number of Pap tests performed. There was no difference in the change in screening between the two regions. Costs were estimated at Au$34 per general practitioner visited. CONCLUSIONS: This strategy cannot be recommended for widespread use in a cervical screening program.

The effects of L-dopa on in vitro and in vivo calcitonin release from medullary thyroid carcinoma.

The in vivo and in vitro effects of the dopamine precursor L-dopa on basal and stimulated calcitonin release from medullary thyroid carcinoma have been studied. In six studies of five patients, including 7- to 8-h control and test periods, oral L-dopa depressed basal calcitonin secretion by an average of 35%; the peak effects occurred within 30 min of drug administration and lasted for as long as 4 h. In seven of eight patients with medullary thyroid carcinoma (three infused with calcium and five with pentagastrin), L-dopa inhibited to varying degrees peak levels of stimulated calcitonin release and total calcitonin secretion; basal calcitonin levels, where directly tested, also again generally fell after L-dopa by an average of 50%. In a short term organ culture system using medullary thyroid carcinoma tissues, calcitonin secretion into the medium was linear with time for 2 h and could be stimulated by dibutyryl cAMP and pentagastrin. L-Dopa, in concentrations from 0.5--3.0 mM, inhibited basal calcitonin secretion (ranging from 25--55%). Addition of the L-dopa decarboxylase inhibitor, alpha-methyldopa, abolished the inhibitory effects of L-dopa. Another L-dopa decarboxylase inhibitor, carbidopa, stimulated calcitonin secretion in vitro; this effect may be independent of the L-dopa decarboxylase-inhibiting properties of this drug since alpha-methyldopa alone did not stimulate calcitonin secretion. It is concluded that the amine precursor L-dopa inhibits calcitonin release in patients with medullary thyroid carcinoma; the in vitro studies suggest that a portion of this effect may involve direct metabolism of L-dopa to dopamine in the tumor tissue itself. The importance of considering the uptake of amine precursors and the subsequent metabolism of these compounds as a modulating site for peptide hormone release from peripheral endocrine tissues is stressed.

Association of diamine oxidase and ornithine decarboxylase with maturing cells in rapidly proliferating epithelium.

Diamine oxidase and ornithine decarboxylase activities are shown to have a parallel distribution across rat small intestine mucosa; levels of both enzyme activities are sharply higher in mature cells in the villus tip region than in proliferating cells in the crypt areas. Histidine decarboxylase levels were not measurable in the same cell preparations and aromatic-L-amino-acid decarboxylase activity was distributed in an opposite pattern to diamine oxidase and ornithine decarboxylase. The results suggest that intestinal diamine oxidase could be involved with polyamine metabolism. The new findings for ornithine decarboxylase suggest an in vivo role for polyamines in non-proliferative cells; rat small intestinal mucosa may be an excellent model for investigating the function of polyamines in regenerating cells.