Scope for growth of Texas Bay scallop Argopecten irradians amplicostatus

Bivalves have exceptional potential as sentinel organisms because their sedentary benthic lifestyle and ability to pump large volumes of water in short periods of time results in bioaccumulation of pollutants and toxins present in the water column. Scope for Growth (SFG) is an instantaneous measure of production that ranges from maximum positive values under optimal conditions to negative valves when the organism is stressed and utilizing its body reserves for maintenance. We determined baseline SFG for the Texas bay scallop Argopecten irradians amplicostatus so that this species might be used to determine sublethal effects of toxins, contaminants, or other environmental stressors in light of recent harmful algal bloom events in the Gulf of Mexico. We also quantified the effects of different diets (phytoplankton, zooplankton, mixed phytoplankton/zooplankton) on Texas bay scallop SFG. SFG of starved animals was negative, indicating that body reserves were used for maintenance. SFG varied significantly (P < 0.001) by diet, with rotifers yielding the highest value (mean = 14.88 Joules hr^?1g dry weight, SE = 0.72). We determined that the Texas bay scallop has presently unrecognized potential as sentinel organisms to define effects of various environmental and anthropogenic perturbations.     

Granulosa cell tumours in the mare: A review of 52 cases

Granulosa cell tumour (GCT) is reported to be the most common ovarian neoplasm in the mare. A multicentre retrospective study evaluating the medical records of horses undergoing ovariectomy for treatment of a GCT was undertaken, documenting the presenting clinicopathological features, treatment and outcome. Follow‐up information was obtained by telephone questionnaire. Fifty‐two mares were included. Most presented with behavioural/reproductive abnormalities, including stallion‐like behaviour (50%), aggression (31%), prolonged oestrus or nymphomania (19%), and persistent anoestrus (8%). Most (93%) affected ovaries had a multilocular appearance when examined ultrasonographically. Only 60% of horses with histopathologically confirmed GCTs demonstrated elevations in serum inhibin concentrations. Twenty‐five percent of horses had histopathologically confirmed bilateral GCTs. Ninety‐four percent of horses that underwent ovariectomy were discharged from the hospital. Standing laparoscopic ovariectomies had a lower complication rate (34%) than other surgical methods. Long‐term complications were uncommon (11%). In conclusion, histopathologically confirmed GCTs can occur in the presence of normal serum inhibin concentrations. The high prevalence of bilateral GCTs indicates that thorough evaluation of the contralateral ovary is necessary. Surgical ovariectomy for treatment of GCTs has favourable short‐ and long‐term outcomes. Standing laparoscopic ovariectomy may be associated with a lower complication rate than other surgical methods.     

Renal carcinoma as a cause of sudden death in an aged horse

This report describes rupture of a primary renal carcinoma as a cause of sudden death of an aged horse that presented with mild clinical signs of colic. The case is considered in the context of the few reported cases in the veterinary literature. The most striking feature of this case was the absence of prodromal signs prior to a catastrophic rupture of the tumour during a diagnostic work‐up.     

Enzymatic synthesis of a selective inhibitor for alpha-glucosidases: alpha-acarviosinyl-(1-->9)-3-alpha-D-glucopyranosylpropen

Here, we describe the enzymatic synthesis of novel inhibitors using acarviosine-glucose as a donor and 3-alpha-D-glucopyranosylpropen (alphaGP) as an acceptor. Maltogenic amylase from Thermus sp. (ThMA) catalyzed the transglycosylation of the acarviosine moiety to alphaGP. The two major reaction products were isolated using chromatographies. Structural analyses revealed that acarviosine was transferred to either C-7 or C-9 of the alphaGP, which correspond to C-4 and C-6 of glucose. Both inhibited rat intestine alpha-glucosidase competitively but displayed a mixed-type inhibition mode against human pancreatic alpha-amylase. The alpha-acarviosinyl-(1-->7)-3-alpha-D-glucopyranosylpropen showed weaker inhibition potency than acarbose against both alpha-glycosidases. In contrast, the alpha-acarviosinyl-(1-->9)-3-alpha-D-glucopyranosylpropen exhibited a 3.0-fold improved inhibition potency against rat intestine alpha-glucosidase with 0.3-fold inhibition potency against human pancreatic alpha-amylase relative to acarbose. In conclusion, alpha-acarviosinyl-(1-->9)-3-alpha-D-glucopyranosylpropen is a novel alpha-glucosidase-selective inhibitor with 10-fold enhanced selectivity toward alpha-glucosidase over alpha-amylase relative to acarbose, and it could be applied as a potent hypoglycemic agent.