Local ecological factors, not interference competition, drive the foundress number of two species of fig wasp sharing Ficus septica figs

Recent studies have challenged assumptions about the classic fig-fig wasp pollination mutualism model, suggesting that further investigation into the receptive phase of fig development is needed. This study assessed the pollination mechanisms of Ficus septica in southern Taiwan and identified two species of wasps as the primary pollinators. Machine learning was used to identify and rank the factors that explain the relative abundance of these wasps. The two wasp species showed the highest level of cohabitation ever reported in the literature, with three-quarters of the figs containing multiple foundresses. The study also reported re-emerged foundresses and a 10% ratio of pollinated figs without foundresses. Local factors, such as the sampling period and tree identity, were the best predictors of the presence and number of each foundress species, with fig size also affecting the number of foundresses. The study highlights the variability in pollinator abundance between figs, crops, and trees. It also shows that the local environment of the trees and the availability of figs are crucial factors in determining which figs the pollinator wasps choose. These findings challenge assumptions about the classic mutualism model and suggest that long-term surveys are needed to estimate the relative contributions of each partner and provide data for evolutionary and ecological models. This study also provides valuable insights into the factors that affect the abundance and interactions of pollinator wasps during the receptive phase of fig development, with implications for understanding the behaviour of pollinating wasps and advancing our knowledge of population dynamics in Ficus species.

Parasitism Features of a Fig Wasp of Genus Apocrypta (Pteromalidae: Pteromalinae) Associated with a Host Belonging to Ficus Subgenus Ficus

Non-pollinating fig wasps (NPFWs), particularly long-ovipositored Sycoryctina wasps, exhibit a high species specificity and exert complex ecological effects on the obligate mutualism between the plant genus Ficus and pollinating fig wasps. Apocrypta is a genus of NPFWs that mostly interacts with the Ficus species under the subgenus Sycomorus, and the symbiosis case between Apocrypta and F. pedunculosa var. mearnsii, a Ficus species under subgenus Ficus, is unique. As fig's internal environments and the wasp communities are distinct between the two subgenera, we addressed the following two questions: (1) Are the parasitism features of the Apocrypta wasp associated with F. pedunculosa var. mearnsii different from those of other congeneric species? (2) Is this Apocrypta species an efficient wasp that lives in its unique host? Our observation revealed that this wasp is an endoparasitic idiobiont parasitoid, as most congeneric species are, but developed a relatively long ovipositor. Furthermore, the relationships of the parasitism rate versus the pollinator number, the fig wall, and the sex ratio of the pollinator, respectively, showed that it possessed a higher parasitism ability than that of other congeners. However, its parasitism rate was low, and thus it was not an efficient wasp in its habitat. This difference between parasitism ability and parasitism rate might be a consequence of its oviposition strategy and the severe habitat conditions. These findings may also provide insights into the mechanism to maintain the interaction between the fig tree and the fig wasp community.

Mediation of a Mutualistic Conflict for Pollination via Fig Phenology and Odor Recognition between Ficus and Fig Wasp

The vegetative and reproductive growth of plants provide the basic tempo for an ecosystem, and when species are interdependent, phenology becomes crucial to regulating the quantity and quality of the interactions. In plant-insect interactions, the plants signal the beginning of their reproductive period with visual and chemical cues; however, in the case of Ficus mutualism, the cues are strictly chemical. The volatile organic compounds emitted by a fig species are a unique, specific blend that provides a signal to mutualistic wasps that the figs are receptive for pollination. In this study, we studied both the phenological pattern of Ficus septica in Central Taiwan and its emissions of volatile compounds at receptivity. This dioecious fig species displays a pattern of continuous vegetative and reproductive production all through the year with a decrease in winter. In parallel, the odor blends emitted by male and female trees are similar but with seasonal variations; these are minimal during winter and increase with the size of the wasp population during the favorable season. In addition, the pollinating females cannot distinguish between the male and female summer odor blends. The link between odor similarity, pollinators and intersexual conflict is discussed.

Exploring systematic biases, rooting methods and morphological evidence to unravel the evolutionary history of the genus Ficus (Moraceae)

Despite many attempts in the Sanger sequencing era, the phylogeny of fig trees remains unresolved, which limits our ability to analyze the evolution of key traits that may have contributed to their evolutionary and ecological success. We used restriction-site-associated DNA sequencing (c. 420 kb) and 102 morphological characters to elucidate the relationships between 70 species of Ficus. To increase phylogenetic information for higher-level relationships, we targeted conserved regions and assembled paired reads into long loci to enable the retrieval of homologous loci in outgroup genomes. We compared morphological and molecular results to highlight discrepancies and reveal possible inference bias. For the first time, we recovered a monophyletic subgenus Urostigma (stranglers) and a clade with all gynodioecious Ficus. However, we show, with a new approach based on iterative principal component analysis, that it is not (and will probably never be) possible to homogenize evolutionary rates and GC content for all taxa before phylogenetic inference. Four competing positions for the root of the molecular tree are possible. The placement of section Pharmacosycea as sister to other fig trees is not supported by morphological data and considered a result of a long-branch attraction artefact to the outgroups. Regarding morphological features and indirect evidence from the pollinator tree of life, the topology that divides Ficus into monoecious versus gynodioecious species appears most plausible. It seems most likely that the ancestor of fig trees was a freestanding tree and active pollination is inferred as the ancestral state, contrary to previous hypotheses. However, ambiguity remains on the ancestral breeding system. Despite morphological plasticity, we advocate restoring a central role to morphology in our understanding of the evolution of Ficus, as it can help detect systematic errors that appear more pronounced with larger molecular datasets.

Use and validation of a survey tool to measure the perceived effectiveness of insulin prescribing safety interventions in UK hospitals

AIMS

To describe the use and validation of a survey tool to elicit the opinion of hospital pharmacists and medicines safety officers in the UK regarding the perceived effectiveness of strategies to improve insulin prescribing safety in hospitals.

METHODS

One respondent from each participating organization completed the survey on behalf of the main acute hospital in their trust (n = 92). A five-point Likert scale was used to determine opinion on how effective 22 different interventions were at promoting insulin safety at the respondent's trust. The tool, the Perception of Effectiveness of Prescribing Safety Interventions for Insulin (PEPSII) questionnaire, underwent content validity testing. The reliability was estimated using Cronbach's alpha (α).

RESULTS

The PEPSII questionnaire demonstrated good reliability (α = 0.867). Outreach team review and mandatory insulin education were the highest-scoring interventions; the insulin passport was amongst the lowest scoring interventions. Most interventions were considered more effective by trusts using them compared to those who didn't, except for self-administration policies, electronic prescribing and the insulin passport.

CONCLUSIONS

The perceived effectiveness of a variety of insulin prescribing safety strategies in UK hospitals was described by leveraging a purposely developed survey tool. The results describe current levels of support for recommended interventions, and may facilitate the direction of both local and national insulin prescribing safety improvement efforts.

Abstract MP26: Endothelial-derived Microvesicles From Andean Highlanders With Excessive Erythrocytosis Induce A Deleterious Cardiomyocyte Phenotype

Background: Excessive erythrocytosis (EE), defined as Hb ≥21 g/dL in men and ≥19 g/dL in women, is a pathologic consequence of residing at high altitude (>2500 m) and is common in Andean highlanders. EE is associated with increased cardiovascular risk and cardiac dysfunction. Specifically, EE has been linked to congestive heart failure as well as right ventricular hypertrophy in high altitude dwellers. The mechanisms responsible for diminished cardiac function in adults with EE remain unclear. Endothelial microvesicles (EMVs) play an important role in mediating interaction between the vascular endothelium and cardiac function. The experimental aim of this study was to determine the effects of EMVs isolated from adults with EE on markers of cardiomyocyte fibrosis, hypertrophy and autophagy as well as endothelial nitric oxide synthase (eNOS).

Methods: Twenty-four male residents of Cerro de Pasco, Peru (4,340 m) were studied: 12 highlanders without EE (Healthy; age: 40±4 yr; BMI: 26.4±1.7; Hb: 17.4±0.5 g/dL) and 12 highlanders with EE (EE: 45±5 yr; 26.7±1.0; 24.4±0.4 g/dL). All subjects were non-obese, normotensive, normolipidemic and non-diabetic. EMVs (CD31+/CD42b-) were identified, enumerated, and isolated from plasma by flow cytometry. Human induced pluripotent stem cell cardiomyocytes were cultured and treated with EMVs from either healthy or EE men.

Results: EMVs from EE men induced significantly greater expression of specific markers of fibrosis: TGF-β (91.1±4.0 vs 52.7±3.8 AU) and alpha-1 type I collagen (85.6±5.6 vs 59.7±4.8 AU) and hypertrophy: troponin T (41.4±2.0 vs 16.9±1.4 AU) and α-actinin (95.3±6.7 vs 62.4±5.0 AU) than EMVs from healthy men. Cell autophagy was not significantly affected by EE EMVs. Intercellular expression of phosphorylated eNOS at the primary activation site, Ser1177 (13.3±1.1 vs 18.9±1.2 AU), and inhibitory site, Thr495 (56.7±3.4 vs 40.8±2.7 AU), were ~35% lower and ~30% higher (both P<0.05), respectively, in cells treated with EMVs from EE compared with healthy men.

Conclusions: These data indicate that EMVs from Andean highlanders with EE negatively affect cardiomyocyte function and, therefore, may contribute to the increased risk of heart failure and cardiac dysfunction associated with EE.

Strategies to reduce insulin prescribing errors in UK hospitals: results from a national survey

AIM

To describe insulin prescribing practice in National Health Service hospitals in the UK and the current use of interventions and strategies to reduce insulin prescribing errors.

METHODS

We sent a cross-sectional questionnaire to chief pharmacists in all National Health Service hospital trusts in the UK in January 2019. Questions concerned the use and functionality of electronic and paper systems used to prescribe subcutaneous insulin, along with features and interventions designed to reduce insulin prescribing errors.

RESULTS

Ninety-five hospital trusts responded (54%). Electronic prescribing of insulin was reported in 40% of hospitals, most of which were teaching hospitals in England. We found a wide variation in the functionality of both electronic prescribing and paper-based systems to enable the safe prescribing of insulin for inpatients. The availability of specialist diabetes pharmacists to support the safe prescribing of insulin was low (29%), but was positively associated with the use of a greater number of insulin prescribing error reduction strategies (P=0.002). The use of specific interventions to improve insulin prescribing quality (e.g. self-administration policies) varied greatly between respondent hospitals.

CONCLUSIONS

There is potential to optimize the functionality of both electronic and paper-based prescribing systems to improve the safe prescribing of insulin in hospitals in the UK. The wide variation in the use of insulin error reduction strategies may be improved by the availability of specialist diabetes pharmacists who can support the implementation of insulin-prescribing interventions.

Interventions to improve insulin prescribing practice for people with diabetes in hospital: a systematic review

AIM

To conduct a systematic review of literature to identify interventions that are effective in improving insulin prescribing for people with diabetes in the hospital setting.

METHODS

Computerized bibliographic databases were searched for studies published in English that described the effectiveness of interventions to improve insulin prescribing within the hospital setting. Studies were eligible for inclusion if they reported data that compared insulin prescribing practice after an intervention or compared with a control group. Studies were not excluded on the basis of publication date, geographical location or risk of bias assessment.

RESULTS

We identified 35 studies for inclusion in the review, including two cluster randomized controlled trials, two cohort studies, and 31 uncontrolled before-after studies. Studies reported a variety of interventions that aimed to increase insulin prescribing accuracy or completeness or decrease the use of discouraged subcutaneous sliding scale insulin regimens. Differences in definition of insulin prescribing error, terminology and common practice based on geographical location was evident, and quality issues with respect to study design and reporting somewhat limited the interpretation of conclusions.

CONCLUSIONS

Implementing strategies that are sensitive to local context and designed to increase adherence to insulin prescribing guidelines are associated with a reduction in prescribing errors. Future implementation should build on effective approaches including multifaceted interventions involving multiple stakeholders at various institutional levels. Future studies in insulin prescribing errors would benefit from the use of standardized approaches, terminology and outcome measures to enable greater comparison.

Effects of climate change on a mutualistic coastal species: Recovery from typhoon damages and risks of population erosion

Presently, climate change has increased the frequency of extreme meteorological events such as tropical cyclones. In the western Pacific basin, these cyclones are called typhoons, and in this area, around Taiwan Island, their frequency has almost doubled since 2000. When approaching landmasses, typhoons have devastating effects on coastal vegetation. The increased frequency of these events has challenged the survival of coastal plant species and their posttyphoon recovery. In this study, a population of coastal gynodioecious Ficus pedunculosa var. mearnsii (Mearns fig) was surveyed for two years to investigate its recovery after Typhoon Morakot, which occurred in August 2009. Similar to all the Ficus species, the Mearns fig has an obligate mutualistic association with pollinating fig wasp species, which requires syconia (the closed Ficus inflorescence) to complete its life cycle. Moreover, male gynodioecious fig species produces both pollen and pollen vectors, whereas the female counterpart produces only seeds. The recovery of the Mearns fig was observed to be rapid, with the production of both leaves and syconia. The syconium:leaf ratio was greater for male trees than for female trees, indicating the importance of syconium production for the wasp survival. Pollinating wasps live for approximately 1 day; therefore, receptive syconia are crucial. Every typhoon season, few typhoons pass by the coasts where the Mearns fig grows, destroying all the leaves and syconia. In this paper, we highlight the potential diminution of the fig population that can lead to the extinction of the mutualistic pair of species. The effects of climate change on coastal species warrant wider surveys.

Diversification and spatial structuring in the mutualism between Ficus septica and its pollinating wasps in insular South East Asia

BACKGROUND

Interspecific interactions have long been assumed to play an important role in diversification. Mutualistic interactions, such as nursery pollination mutualisms, have been proposed as good candidates for diversification through co-speciation because of their intricate nature. However, little is known about how speciation and diversification proceeds in emblematic nursery pollination systems such as figs and fig wasps. Here, we analyse diversification in connection with spatial structuring in the obligate mutualistic association between Ficus septica and its pollinating wasps throughout the Philippines and Taiwan.

RESULTS

Ceratosolen wasps pollinating F. septica are structured into a set of three vicariant black coloured species, and a fourth yellow coloured species whose distribution overlaps with those of the black species. However, two black pollinator species were found to co-occur on Lanyu island. Microsatellite data on F. septica indicates the presence of three gene pools that broadly mirrors the distribution of the three black clades. Moreover, receptive fig odours, the specific message used by pollinating wasps to locate their host tree, varied among locations.

CONCLUSIONS

F. septica and its black pollinator clades exhibited similar geographic structuring. This could be due originally to geographic barriers leading to isolation, local adaptation, and finally co-structuring. Nevertheless, the co-occurrence of two black pollinator species on Lanyu island suggests that the parapatric distribution of the black clades is now maintained by the inability of migrating individuals of black pollinators to establish populations outside their range. On the other hand, the distribution of the yellow clade strongly suggests an initial case of character displacement followed by subsequent range extension: in our study system, phenotypic or microevolutionary plasticity has allowed the yellow clade to colonise hosts presenting distinct odours. Hence, while variation in receptive fig odours allows specificity in the interaction, this variation does not necessarily lead to coevolutionary plant-insect diversification. Globally, our results evidence evolutionary plasticity in the fig-fig wasp mutualism. This is the first documentation of the presence of two distinct processes in pollinating fig wasp diversification on a host species: the formation of vicariant species and the co-occurrence of other species over large parts of their ranges probably made possible by character displacement.

Sexual specialization in phenology in dioecious Ficus benguetensis and its consequences for the mutualism

BACKGROUND

Timing of reproductive events has become central in ecological studies linking success in pollination and seed dispersion to optimizing the probability and periods of encounters with pollinators or dispersers. Obligate plant-insect interactions, especially Ficus-fig wasp mutualisms, offer striking examples of fine-tuned encounter optimization as biological cycles between mutualistic partners are deeply dependent on each other and intertwined over generations. Despite fig flowering phenology being crucial in maintaining Ficus-fig wasp mutualisms, until now, the forces of selection shaping the phenological evolution of dioecious fig trees have received little attention. By conducting a 2-year survey of a population of Ficus benguetensis in Northern Taiwan, we assessed whether environmental factors or other selective pressures shape the phenology of male and female fig trees.

RESULTS

Constraints by mutualistic pollinating wasps and seed dispersers, rather than climatic factors, appeared to mainly shape fig phenology and allometry in F. benguetensis. We identified a new sexual specialization in dioecious fig trees: the position of fig production. We propose that the continuous male fig production on tree trunks can enhance the survival of pollinating fig wasps through faster localization of receptive figs while reducing the mutualistic conflict between the fig and its obligate pollinators. By contrast, in female trees, fig production is massive in summer, located on the twigs of the foliar crown and seem more related to seed dispersal and germination.

CONCLUSIONS

Identifying variations in the allometry and phenology of dioecious figs provide valuable insights into how monoecious and dioecious species resolve mutualism conflicts and into the emergence of dioecy in fig trees.

Ficus (Moraceae) and fig wasps (Hymenoptera: Chalcidoidea) in Taiwan

Although Ficus-associated wasp fauna have been extensively researched in Australasia, information on these fauna in Taiwan is not well accessible to scientists worldwide. In this study, we compiled records on the Ficus flora of Taiwan and its associated wasp fauna. Initial agronomic research reports on Ficus were published in Japanese in 1917, followed by reports on applied biochemistry, taxonomy, and phenology in Chinese. On the basis of the phenological knowledge of 15 species of the Ficus flora of Taiwan, recent research has examined the pollinating and nonpollinating agaonid and chalcid wasps (Hymenoptera: Chalcidoidea). Updating records according to the current nomenclature revealed that there are 30 taxa (27 species) of native or naturalized Ficus with an unusually high proportion of dioecious species (78%). Four species were observed to exhibit mutualism with more than one pollinating wasp species, and 18 of the 27 Ficus species were reported with nonpollinating wasp species. The number of nonpollinating wasp species associated with specific Ficus species ranges from zero (F. pumila) to 24 (F. microcarpa). Approximately half of the Taiwanese fig tree species have been studied with basic information on phenology and biology described in peer-reviewed journals or theses. This review provides a solid basis for future in-depth comparative studies. This summary of knowledge will encourage and facilitate continuing research on the pollination dynamics of Ficus and the associated insect fauna in Taiwan.

Portable microsatellite primers for Ficus (Moraceae)

PREMISE OF THE STUDY

Highly portable microsatellite primers were developed for Ficus to facilitate investigation of genetic structure of complete regional floras using a single set of markers.

METHODS AND RESULTS

Pyrosequencing of five species of Ficus produced a library of 5723 potential primers. Potential primers found in at least two species and presenting identical annealing temperatures were tested on a set of five additional Ficus species. A set of 20 primer pairs producing well-defined and easily readable peaks was retained and tests showed their potential utility for analyzing population genetic structure of 24 Ficus species from Taiwan. Numbers of alleles per locus ranged from one to six in the least variable species and from one to 17 in the most variable species.

CONCLUSIONS

The results indicate that our set of primers can be used to analyze polymorphism and compare levels of polymorphism among Ficus species.

Glutamine protects function and improves preservation of small bowel segments

BACKGROUND

Improved organ preservation is essential for the success of small bowel transplantation. Small bowel is usually preserved in UW (University of Wisconsin) solution which does not contain glutamine (Gln), the principal fuel for the enterocyte. We hypothesized that Gln-supplemented UW would improve mucosal function and structure of cold preserved small intestine.

MATERIALS AND METHODS

Jejunum (40 cm) was harvested from Lewis rats and preserved for 18 hr at 4 degrees C in saline; UW solution only; UW with 1, 2, or 4% Gln; and UW containing 1, 2, or 4% isonitrogenous balanced nonessential amino acids (NEAA). 14C glucose transport, mucosal protein, mucosal maltase and alkaline phosphatase, jejunal villous height, and histologic damage were measured.

RESULTS

UW with 2% Gln significantly increased glucose transport and mucosal protein when compared to the 2% NEAA and UW-only groups. Two percent Gln significantly decreased histologic damage of jejunum following cold preservation. Increasing Gln to 4% did not significantly increase its efficacy when compared to the UW with 2% Gln group. There were no significant differences in the activities of mucosal maltase and alkaline phosphatase among the various treatment groups.

CONCLUSIONS

The addition of Gln, optimally provided at a concentration of 2%, to UW solution may protect the preserved small bowel segments from cold ischemic injury and improve mucosal function.

Resection-induced colonic adaptation is augmented by IGF-I and associated with upregulation of colonic IGF-I mRNA

The effects of exogenous insulin-like growth factor-I (IGF-I) on colonic adaptation were examined in male Sprague-Dawley rats (n = 60, 225-275 mg) after either a 60% small bowel and cecal resection (RX) or mid-small bowel transection with reanastomosis (TX). Animals received a 7-day treatment with either IGF-I (2.4 mg.kg-1.day-1) or vehicle (V; 0.1 mol/l acetic acid). Body weight decreased significantly after resection (-25.6 +/- 4.0 g; P < 0.05 vs. TX/V). IGF-I treatment significantly reduced weight loss after resection (-12.4 +/- 3.8 g; P < 0.01 vs. RX/V) and induced significant weight gain after transection (15.6 +/- 4.0 g; P < 0.05 vs. TX/V). Plasma IGF-I decreased with resection (526 +/- 41 TX/V vs. 344 +/- 17 ng/ml RX/V; P < 0.01). IGF-I treatment significantly increased plasma IGF-I levels (805 +/- 100 ng/ml TX/IGF, 677 +/- 56 ng/ml RX/IGF). After resection, IGF-I treatment significantly increased colonic mucosal weight, DNA, protein content, and crypt depth when compared with resection alone (P < 0.05). Colonic water absorption, measured by an in vivo [3H]polyethylene glycol assay, was significantly increased by IGF-I treatment in resected animals (399 +/- 23 RX/IGF vs. 306 +/- 32 microliter.cm-1.h-1 RX/V; P < 0.05). Resection resulted in increased steady-state colonic IGF-I mRNA (182% of TX/V; P < 0.01) without significantly affecting IGF-I receptor mRNA expression. Regulation of IGF binding protein (BP)-3 and -4 was discoordinate, with IGFBP-3 mRNA tending to decrease with resection (67% of TX/V; P is not significant) and IGFBP-4 increasing significantly (191% of TX/V; P < 0.05). An important role for IGF-I in colonic adaptation after massive intestinal resection is indicated by 1) significantly enhanced colonic mucosal growth and water absorption with IGF-I treatment and 2) postresection upregulation of colonic IGF-I mRNA and alteration of IGFBP-3 and IGFBP-4 mRNA expression.

Insulin-like growth factor-I (IGF-I) and glutamine improve structure and function in the small bowel allograft

IGF-I, a mitogenic polypeptide hormone, and glutamine (GLN), the preferred enterocyte fuel, singularly improve growth and structure of the small bowel isograft; however, their combined effects on intestinal allografts are unknown. This study examined the effects of IGF-I and GLN, singularly and in combination, on the structure and function of the intestinal allograft. Fifty-nine adult rats underwent resection of the distal 60% of small bowel and received either a 40-cm isograft or an allograft. Either IGF-I (2.4 mg/kg/day) or its vehicle was infused continuously by subcutaneous minipumps. An isocaloric polymeric diet with either 2% GLN or isonitrogenously balanced 2% nonessential amino acids was given continuously by gastrostomy for 10 days. Five groups were studied: isograft (ISO) alone, allograft (ALLO) alone, ALLO and GLN, ALLO and IGF-I, and ALLO and IGF-I with GLN. All recipients received Cyclosporine A (15 mg/kg, im) daily. Mucosal villus height, surface area, crypt depth, IgA, IgG, IgM, and intercellular adhesion molecule-1 (ICAM-1) plasma cells in intestinal tissue, glucose and water absorption of intestinal graft, bacterial translocation (BT) to mesenteric lymph nodes, and body weight were determined. IGF-I increased villus height, surface area (P < 0.001), crypt depth (P < 0.01), and glucose absorption (P < 0.05) compared to the ISO and ALLO groups. GLN increased only crypt depth when compared to the ALLO group (P < 0.01). Both IGF-I and GLN independently decreased BT to MLN (P < 0.05) and, in combination, enhanced water absorption (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor-I improves mucosal structure and function in transplanted rat small intestine

The transplanted small intestine develops significant mucosal atrophy, impaired nutrient and water absorption, and increased bacterial translocation to mesenteric lymph nodes in rats maintained on elemental diets or total parenteral nutrition. This study determined the effects of administration of an peptide growth factor (insulin-like growth factor-I[IGF-I]) on the mucosal structure and barrier function of rat small bowel isografts. Thirty-six adult Lewis rats underwent either resection of the distal 60% of the small bowel and proximal colon followed by a 40-cm orthotopic jejunal isograft or proximal small bowel transection and distal small bowel resection to leave an analogous length of small intestine in control animals. All rats received an isocaloric, isonitrogenous, polymeric diet (200 kcal/kg/day, 2 gN/kg/day) by gastrostomy and were infused with either IGF-I (2.4 mg/kg/day) or vehicle by osmotic pumps subcutaneously. After 10 days of treatment, jejunal crypt cell production, mucosal morphometric indices, glucose and water absorption, body weight, and bacterial translocation to mesenteric lymph nodes (MLN) were measured. Jejunal mRNA content for IGF-I, IGF-I receptor, and IGF-binding proteins 3 and 4 (IGFBP-3,4) were determined by Northern blotting. Crypt cell production, villus height, crypt depth, and villus surface area were significantly increased in control and transplanted jejunum of rats infused with IGF-I when compared to animals given vehicle alone. Additionally, jejunal glucose absorption and water absorption were significantly improved in both IGF-I groups when compared with their respective vehicle controls. IGF-I infusion increased body weight in transplanted and control animals and markedly reduced bacterial translocation to MLN after small bowel transplantation. Jejunal levels of IGF-I mRNA were significantly increased in transplanted animals when compared to transected controls. IGF-I treatment significantly increased IGFBP-3 tissue mRNA levels in both transected and transplanted animals. These results demonstrate that IGF-I administration, after small bowel transplantation, improves mucosal structure and absorptive function and reduces bacterial translocation to MLN. IGF-I may have important effects in transplanted small bowel both as an endogenous and administered growth factor.

Glutamine reduces bacterial translocation after small bowel transplantation in cyclosporine-treated rats

Bacterial translocation (BT) of enteric organisms is a major cause of sepsis in patients undergoing small bowel transplantation (SBT). Cyclosporine (CsA) may be toxic to intestinal epithelium and increase the risk of BT. Glutamine (Gln) is the preferred enterocyte fuel and maintains graft epithelial integrity in experimental SBT. This study determined the effects of CsA on mucosal structure and function of transplanted intestinal isograft and examined whether Gln-enriched diet reversed CsA-induced intestinal toxicity. Thirty-three adult Lewis rats underwent resection of the distal 60% of small bowel and received an orthotopic jejunal isograft. Rats received either elemental diet with 2% Gln or the same diet with balanced nonessential amino acids (non-Gln) by gastrostomy for 10 days. CsA (15 mg/kg, im) or olive oil was injected daily. Rats were assigned to four groups: non-Gln with vehicle, non-Gln with CsA, Gln with vehicle, and Gln with CsA. Mucosal villous height, surface area, crypt depth, 14C glucose absorption, BT to mesenteric lymph nodes (MLN), and body weight change were evaluated. The non-Gln with CsA group had the highest incidence of BT (P < 0.001). Gln groups had significantly decreased BT (P < 0.01) and increased crypt depth and villous surface area (P < 0.01) when compared to non-Gln groups. Body weight significantly decreased in CsA groups when compared to non-CsA groups (P < 0.01). These results indicate at CsA significantly decreased body weight and increased BT without decreasing mucosal structure and glucose absorption of intestinal isografts.(ABSTRACT TRUNCATED AT 250 WORDS)

Fiber: effect on bacterial translocation and intestinal mucin content

Total parenteral nutrition (TPN) and elemental diet (ED) produce intestinal atrophy and increase bacterial translocation (BT) to mesenteric lymph nodes. The increased rate of BT may be due to alterations in mucosal structure, enzyme activity, or mucin content. Fiber improves intestinal structure and function in rats and may reduce the rate of BT. This study determined whether the addition of fiber to TPN or ED would maintain intestinal integrity and decrease BT to the mesenteric lymph nodes. Fifty-six adult male Sprague-Dawley rats underwent placement of jugular catheters and were assigned to one of five dietary groups: TPN, TPN+oral oat fiber (TPNF) 2 g/day, ED, ED+oral oat fiber (EDF) 2 g/day, or AIN-76 (control); they were pair-fed for 7 days. On day 8 the mesenteric lymph nodes were removed for bacterial cultures; and jejunal mucosal weight, DNA, protein, alkaline phosphatase, maltase, and jejunal mucin content were measured. Enteral nutrition significantly decreased BT when compared to parenteral feeding, and fiber significantly decreased BT when administered to rats receiving TPN or ED. Improvements in intestinal mucosal structure were not consistently associated with decreased rates of BT. Additionally, BT occurred independently of jejunal mucin concentration. Mechanisms other than maintenance of mucosal structure or mucin content are important in the mediation of fiber-induced decreased BT in rats receiving TPN or ED.

Butyrate increases colonocyte protein synthesis in ulcerative colitis

Butyrate promotes epithelial cell healing and improves symptoms when administered rectally in patients with distal ulcerative colitis (UC). It was hypothesized that butyrate may enhance healing in patients with UC by stimulating colonocyte proliferation and/or protein production. Mucosa from the descending colon was obtained from patients with UC (n = 5), Crohn's disease (n = 8), diverticulitis (n = 6), and cancer (normal tissue 10 cm from tumor; n = 10). Epithelial cells were isolated using dispase/collagenase and differential sedimentation and incubated for 4 hr at 37 degrees C with either Na butyrate (10 mM) or NaCl (10 mM). Protein synthesis was assessed by [14C]leucine incorporation and proliferation was determined with [3H]thymidine. Mean viability and purity were >88%. Spontaneous proliferation was significantly increased in UC when compared to diverticulitis and normal controls. Butyrate significantly increased protein synthesis in UC epithelial cells when compared to saline control. The therapeutic effects of butyrate in patients with UC may be due to its use by epithelial cells as a metabolic fuel to increase protein production and promote healing.

Validity of a perceived exertion scale for children: a pilot study

The purpose of this study was to examine the validity of a recently developed rating scale of perceived exertion, the Children's Effort Rating Table (CERT), for controlling exercise intensity in young children. 16 children (M age = 9.9 yr., SD = 1.2) performed three separate exercise tests on a mechanically braked cycle ergometer. Stage I (response protocol) consisted of a graded test with heart rate and perceived effort rating recorded in response to specified steady-state work outputs. Stage II (production protocol) examined subjects' ability to produce work outputs corresponding to levels 5, 7, and 9 of the CERT. This protocol was repeated on a further occasion (Stage III) to assess the reliability of the findings. Pearson correlations between ratings and heart rate (0.76) and ratings and work output (0.75) highlight the potential of the scale as a valid measure of exercise intensity. Also, the work rates produced by subjects in Stage II correlated 0.89 with those predicted from Stage I; however, analysis of variance showed that work output was significantly lower in Stage II than predicted. Finally, an intraclass correlation of 0.91 between Stages II and III suggests that the scale gave a reliable estimate of exercise intensity of children. The findings from this pilot study suggest that children's perceptions of effort might be used to guide intensity of exercise during structured activity classes.

Infectious drug resistance during an outbreak of samonellosis

The sudden acquisition of aminoglycoside resistance among Salmonella group C1 isolates causing summer diarrhoea raised the possibility oif plasmid-mediated reistance. The demonstration of circular DNA species in the resistant, but not in the sensitive salmonellae and the transfer by conjugation of antibiotic resistance to a sensitive strain of Escherichic coli, was consistent with plasmid-mediated resistance.