Digestive capabilities reflect the major food sources in three species of talitrid amphipods

Digestive enzyme activities of three talitrid amphipods were examined to investigate the relationship between their digestive capabilities and diet. Laminarinase, cellobiase, carboxymethyl-cellulase, xylanase, alpha- and beta-glucosidase and lipase were detected in all three species suggesting talitrid amphipods can readily digest dietary carbohydrate and lipid, including complex polysaccharides. Relatively high specific enzyme activity (Units (mg(-1) digestive tract protein)(-1)) of laminarinase and lipase was detected in Talorchestia marmorata, a supralittoral kelp feeder which is coherent with the digestion of lipid-esters and beta-glucans (laminarin) which are the main lipid and storage polysaccharides of brown seaweeds. Talorchestia sp., a low shore intertidal feeder, had high enzymatic activity of alpha- and beta-glucosidase, cellobiase and xylanase, which is consistent with the digestion of diatoms. Keratroides vulgaris, a forest litter feeder had a relatively low specific activity of all enzymes. It is possible that leaf litter is partially digested prior to ingestion by bacteria and fungi present in the rotting vegetation, with bacterial and fungal enzymes contributing to this species' ability to hydrolyse its diet. This study provides the first quantitative data on digestive capacity in these three talitrid amphipods and confirms the relationship between dietary preference and digestive enzyme complement.     

Post burn muscle wasting and the effects of treatments

Severe burns are typically followed by a hypermetabolic response that lasts for at least 9-12 months post-injury. The endocrine status is also markedly altered with an initial and then sustained increase in proinflammatory 'stress' hormones such as cortisol and other glucocorticoids, and catecholamines including epinephrine and norepinephrine by the adrenal medulla and cortex. These hormones exert catabolic effects leading to muscle wasting, the intensity of which depends upon the percentage of total body surface area (TBSA) involved, as well as the time elapsed since initial injury. Pharmacological and non-pharmacological strategies may be used to reverse the catabolic effect of thermal injury. Non-pharmacological strategies include early excision and wound closure of burn wound, aggressive treatment of sepsis, elevation of the environmental temperature to thermal neutrality (31.5+/-0.7 degrees C), high carbohydrate, high protein continuous enteral feeding and early institution of resistive exercise programs. Pharmacological modulators of the post-burn hypermetabolic response may be achieved through the administration of recombinant human growth hormone, low dose insulin infusion, use of the synthetic testosterone analogue, oxandrolone and beta blockade with propranolol. This paper aims to review the current understanding of post-burn muscle proteolysis and the effects of clinical and pharmacological strategies currently being studied to reverse it curb these debilitating sequelae of severe burns.     

Genotypic characterization of bacteria cultured from duck faeces

AIMS: To characterize the bacterial composition of mallard duck faeces and determine if novel bacterial species are present that could be utilized as potential indicators of avian faecal contamination. METHODS AND RESULTS: Combined samples of fresh faeces from four ducks were serially diluted and plated onto six different media selected to allow the growth of a range of organisms at 42 degrees C under three atmospheric conditions: aerobic, microaerophilic and anaerobic. Forty-seven morphologically dissimilar isolates were purified and partial sequencing of the16S rRNA indicated at least 31 bacterial species. Twenty of these could be identified to the species level including pathogenic species of Bacillus, Campylobacter, Clostridium and Streptococcus. Other species identified included: Enterococcus, Escherichia, Megamonas, Cellulosimicrobium, Neisseria, Staphylococcus and Veillonella. Potentially novel species, which could represent bacteria specific to avian fauna included Bacillus, Corynebacterium, Macrococcus and Peptostreptococcus, while four isolates had <97% similarity to known bacterial species in the available databases. CONCLUSION: A survey of the natural microflora of the mallard duck and its hybrid with the grey duck identified both bacteria that are potentially human pathogenic and putative novel bacteria species as determined by 16S rRNA sequencing. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides further evidence that duck faeces is a potential human health hazard, and has identified bacteria potentially useful for distinguishing duck faeces from other faecal sources.     

FGFR1 function at the earliest stages of mouse limb development plays an indispensable role in subsequent autopod morphogenesis

Fibroblast growth factors (FGFs) and their receptors have been implicated in limb development. However, because of early post-implantation lethality associated with fibroblast growth factor receptor 1 (FGFR1) deficiency, the role of this receptor in limb development remains elusive. To overcome embryonic lethality, we have performed a conditional knockout of Fgfr1 using the Cre-LoxP approach. We show that Cre-mediated deletion of Fgfr1 in limb mesenchyme, beginning at a time point slightly after the first sign of initial budding, primarily affects formation of the first one or two digits. In contrast, deletion of Fgfr1 at an earlier stage, prior to thickening of limb mesenchyme, results in more severe defects, characterized by malformation of the AER, diminished Shh expression and the absence of the majority of the autopod skeletal elements. We show that FGFR1 deficiency does not affect cell proliferation. Instead, it triggers cell death and leads to alterations in expression of a number of genes involved in apoptosis and digit patterning, including increased expression of Bmp4, Dkk1 and Alx4, and downregulation of MKP3. These data demonstrate that FGF/FGFR1 signals play indispensable roles in the early stages of limb initiation, eliciting a profound effect on the later stages of limb development, including cell survival, autopod formation and digit patterning.     

Synthesis and SAR of 2,3-diarylpyrrole inhibitors of parasite cGMP-dependent protein kinase as novel anticoccidial agents

Several analogs of 2,3-diaryl pyrroles were synthesized and evaluated as inhibitors of Eimeria tenella cGMP-dependent protein kinase and in in vivo anticoccidial assays. A 4-fluorophenyl group enhances both in vitro and in vivo activities. The most potent analogs are the 5-(N-methyl, N-ethyl, and N-methylazetidine methyl) piperidyl derivatives 12, 23, and 34. These compounds have a broad spectrum of activity. Based on the in vivo efficacy and cost of synthesis, the N-ethyl analog 23 was chosen as a novel anticoccidial agent for a field trial.     

Bradykinin B1 antagonists: SAR studies in the 2,3-diaminopyridine series

SAR study of the biphenyl region of 2,3-diaminopyridine bradykinin B1 antagonists was investigated with non-aromatic carbo- and heterocyclic rings. A piperidine ring was found to be a good replacement for the proximal phenyl ring while replacement of the distal phenyl was optimal with a cyclohexyl group leading to a dramatic improvement in affinity for the B1 receptor.     

Tetrahydroisoquinoline 1-carboxamides as growth hormone secretagogues

Several novel series of tetrahydroisoquinoline 1-carboxamides were prepared and shown to be potent growth hormone (GH) secretagogues. Among them, carbamate 12a-E2 displays excellent in vivo activity by increasing plasma GH 10-fold in an anesthetized IV rat model.