Comparison of a Pre-Trained AI Contouring Model to Unseen Institutional Data

PURPOSE/OBJECTIVE(S)

To compare contours generated by a pre-trained, commercial AI model to those manually drawn in house.

MATERIALS/METHODS

Previously treated radiotherapy patients (N = 20 per site) for several sites (brain, head & neck, thorax, abdomen, pelvis) with approved structure sets were selected for this retrospective analysis. For the planning CT of each patient, a pre-trained AI model auto-contoured several OARS: bladder, brain, eyes, femurs, kidneys, lenses, mandible, and parotids, etc. A two-step rejection method filtered the results based on unmatched structure names (i.e., contours existing in only one of the two structure sets causing incorrect auto-matching of structure names by the comparison algorithm), and structures with different superior and/or inferior extents. From the remaining contours, DSC (Dice Similarity Coefficient) and HD95% (95th percentile of Hausdorff Distance) were calculated between auto and manually generated contours using vendor-supplied software; median values were then calculated.

RESULTS

The entire data set contained 592 structures at the on-set of analysis. After applying the rejection filters, the remaining data had 294 structures; a large portion of filtering was due to unmatched names. Out of these, OARs with contours from at least 10 patients (N>9) were further analyzed to include the 25th and 75th percentile for DSC and HD95%. Results from this analysis (structures with N>9) are presented in the table below, where results of left-right paired structures are combined into one row. The submandibular glands, larynx, and optical nerves (5 < N < 10) all had median DSC < 0.77 while lungs had median DSC > 0.98 (N = 6). Parotids and lenses had poor DSC and HD95% scores and may require significant contour editing to achieve agreement with our clinical conventions. This study highlights the difficulty with retrospective analysis of contours with an external trained model due to variations in the superior/inferior extent of tubular structures such as rectum, cord, esophagus, etc. CONCLUSION: Results are encouraging, given that the pre-trained commercial model has not seen our institutional data. The pre-trained AI contouring model matched very well to manual contours for large volume, higher contrast structures but did not match well for parotids and lenses. Variability in conventions regarding the superior/inferior extent of some structures hinders retrospective comparison with a pre-trained AI model.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

A return-on-investment approach for prioritization of rigorous taxonomic research needed to inform responses to the biodiversity crisis

Global biodiversity loss is a profound consequence of human activity. Disturbingly, biodiversity loss is greater than realized because of the unknown number of undocumented species. Conservation fundamentally relies on taxonomic recognition of species, but only a fraction of biodiversity is described. Here, we provide a new quantitative approach for prioritizing rigorous taxonomic research for conservation. We implement this approach in a highly diverse vertebrate group-Australian lizards and snakes. Of 870 species assessed, we identified 282 (32.4%) with taxonomic uncertainty, of which 17.6% likely comprise undescribed species of conservation concern. We identify 24 species in need of immediate taxonomic attention to facilitate conservation. Using a broadly applicable return-on-investment framework, we demonstrate the importance of prioritizing the fundamental work of identifying species before they are lost.

A new species of large green treefrog (Litoria, Pelodryadidae) from Papua, Indonesia

We describe a new species of large green treefrog from southern Papua Province, Indonesia. Litoria lubisi sp. nov. is placed in the L. infrafrenata Group based on its size, colouration and configuration of hand webbing, but differs from other members of this group in aspects of body size and proportions, extent of hand webbing, colouration and male advertisement call. Litoria lubisi sp. nov. occurs in close proximity to two other species in the L. infrafrenata Group, emphasising an until-recently overlooked pattern that multiple species of large, arboreal Litoria have overlapping distributions across much of the lowlands of southern New Guinea.

Diversification across biomes in a continental lizard radiation

Ecological opportunity is a powerful driver of evolutionary diversification, and predicts rapid lineage and phenotypic diversification following colonization of competitor-free habitats. Alternatively, topographic or environmental heterogeneity could be key to generating and sustaining diversity. We explore these hypotheses in a widespread lineage of Australian lizards: the Gehyra variegata group. This clade occurs across two biomes: the Australian monsoonal tropics (AMT), where it overlaps a separate, larger bodied clade of Gehyra and is largely restricted to rocks; and in the larger Australian arid zone (AAZ) where it has no congeners and occupies trees and rocks. New phylogenomic data and coalescent analyses of AAZ taxa resolve lineages and their relationships and reveal high diversity in the western AAZ (Pilbara region). The AMT and AAZ radiations represent separate radiations with no difference in speciation rates. Most taxa occur on rocks, with small geographic ranges relative to widespread generalist taxa across the vast central AAZ. Rock-dwelling and generalist taxa differ morphologically, but only the lineage-poor central AAZ taxa have accelerated evolution. This accords with increasing evidence that lineage and morphological diversity are poorly correlated, and suggests environmental heterogeneity and refugial dynamics have been more important than ecological release in elevating lineage diversity.

Two new species of Choerophryne (Anura, Microhylidae) from the northern versant of Papua New Guinea's central cordillera

We describe two new species of small microhylid frogs in the genus Choerophryne from the northern slopes of Papua New Guinea's central cordillera. Choerophryne epirrhina sp. nov. can be distinguished from congeners by the combination of moderately small size (SUL 14.9-15.0 mm), distinctly elongated snout (OHG/SUL 0.09-0.10), first finger without expanded disk, and advertisement call consisting of 3-4 distinctly pulsed notes repeated in long sequences. Choerophryne grylloides sp. nov. can be distinguished from congeners by the combination of very small size (SUL 12.5 mm), moderately long snout (OHG/SUL 0.08), long legs (TL/SUL 0.42), first finger without expanded disk and advertisement call consisting of 4-5 distinctly pulsed notes, the last of which has many more pulses than preceding notes (9-10 vs. 3-4).

The intake of high-fat diets induces the acquisition of brown adipocyte gene expression features in white adipose tissue

BACKGROUND/OBJECTIVE

White-to-brown adipose tissue remodeling (browning) in response to different stimuli constitutes an active research area for obesity treatment. The emergence in traditional white adipose tissue (WAT) depots of multilocular adipocytes that express uncoupling protein 1 (UCP1) and resemble brown adipocytes, the so called 'brite' adipocytes, could contribute to increased energy expenditure. In rodents, obesogenic stimuli such as the intake of hyperlipidic diets can increase brown adipose tissue (BAT) thermogenic capacity and contribute to maintaining body weight. The aim of this study was to investigate the potential of two different hyperlipidic diets, a commercial high-fat (HF) diet and a highly palatable cafeteria (CAF) diet, to induce WAT browning.

METHODS

We analyzed gene expression of a wide number of brown/brite adipocyte markers in different WAT depots, in BAT and in peripheral blood mononuclear cells (PBMCs) increasingly being used in nutrition studies as a potential source of biomarkers of physiological effects. We also performed morphological analysis of adipose tissue.

RESULTS

Both HF diets studied were able to increase the expression of the markers studied in WAT in a depot-specific manner, as well as in BAT; some of these changes were also reflected in PBMCs. This increased browning capacity was translated into the appearance of UCP1- and CIDE-A (cell death-inducing DFFA-like effector A)-positive brite adipocytes in retroperitoneal WAT. Administration of the CAF diet, associated with higher adiposity, produced the strongest impact on the parameters studied while its withdrawal restored basal conditions.

CONCLUSIONS

Acquisition of brown adipocyte features in WAT could evidence an adaptation to try to counteract increased adiposity due to the intake of HF diets. Additionally, PBMCs could constitute an interesting easily obtainable material to assess the effect of nutritional interventions on browning capacity.

Prevalence of aggressive challenging behaviours in intellectual disability and its relationship to personality status: Jamaican study

BACKGROUND

Both the classification of personality disorder in intellectual disability (ID) and its identification in practice are deemed to be difficult. A simpler approach to classification and its relationship to challenging behaviours were tested in an adult Jamaican population with ID.

METHOD

The study was carried out in Kingston, Jamaica, as part of a programme of field trials to determine the utility of the proposed revision of personality disorders in the 11th Revision of the International Classification of Diseases (ICD-11), in a population of adults with ID living with their families or in supported care homes. Thirty-eight people with borderline (n = 5), mild (n = 16), moderate (n = 14) and severe (n = 3) ID were assessed at face-to-face interview and with relatives or staff using the provisional criteria for severity of personality disorder and its associated domain traits, and challenging behaviour was assessed using the Problem Behaviour Check List (PBCL) (a 5-point, 7-item scale).

RESULTS

Using the severity scale 18 patients (47%) had no personality disorder, 7 (18%) had personality difficulty, 9 (24%) had mild personality disorder, and 4 (11%) had moderate personality disorder. None of the sample had severe personality disorder in which there is high risk of harm to self or others. Of the four major trait domains, provisionally named anankastic, detached, emotional and dissocial, three were evenly distributed in those with personality disturbance with the antagonistic (antisocial) trait less commonly shown (6 only). Scores on the PBCL were higher in those with increasing severity of personality disorder (P = 0.03) and those in the antagonistic personality trait domain had the highest PCL scores.

CONCLUSIONS

Despite previous difficulties in assessing personality disorder in intellectual difficulties the ICD-11 classification was easy to administer in practice in this population, and the higher problem behaviour scores in those with greater severity of personality disturbance support its construct validity.

A new species of Choerophryne (Anura, Microhylidae) from the central cordillera of Papua New Guinea

We describe a new species of very small microhylid frog in the genus Choerophryne from the upper Strickland River area, Western and Southern Highlands Provinces, Papua New Guinea. Choerophryne gracilirostris sp. nov. can be distinguished from congeners by the following combination of characters: small size (SUL 13.5-14.7 mm), moderately long and narrow snout, first finger without expanded disk and advertisement call consisting of 3-5 distinctly pulsed notes repeated in long sequences. Males in the type series were calling from within leaf litter in primary hill rainforest (213-1368 m a.s.l.). The new species is the third Choerophryne known from the southern side of New Guinea's central cordillera. Measurements of a juvenile specimen (rare because most Choerophryne collected are calling males) demonstrate that the distinctive rostral projection of this genus exhibits pronounced positive allometry.

New approaches to cataloguing and understanding evolutionary diversity: a perspective from Australian herpetology

Species are a fundamental unit for all fields of biology but conceptual and practical limitations have hampered the process of identifying and describing species in many organismal groups. One outcome of these challenges is the accumulation of genetically divergent lineages and morphologically distinctive populations that are ‘known’, but remain of uncertain taxonomic status and evolutionary significance. These lineages are also currently not effectively incorporated into evolutionary studies or conservation planning and management. Here we suggest three ways to address this issue. First, there is a need to develop improved frameworks to systematically capture taxonomically unrecognised lineage diversity. Second, increased utilisation of metadata frameworks will allow better recording and dissemination of biodiversity information. Finally, emerging genomic and analytical techniques will provide powerful new tools to improve our identification and understanding of evolutionary lineages.

Drug-related death following release from prison: a brief review of the literature with recommendations for practice

Mortality from drug-related death is a significant contributor to the loss of life of young people in the UK. Despite attention, the high death rate from this cause continues to persist. One of the most frequently cited factors involved in drug-related death (DRD) is release from prison. This review aims to examine the published literature with a view to quantifying the risk associated with recent prison release and identifying risk factors and prevention strategies. Most deaths following release from prison are caused by overdose, usually from opioid use. The risk of death is greatest within the first week of release but, when compared with the general population, continues to be elevated for several weeks. Relative risk estimates suggest that those released from prison are up to 40 times more likely to die than similar individuals from the general population. Other than gender and an association with poor mental health, there is little in the way of robust risk factors for post-release death that could be identified from the literature. In-prison pharmacological maintenance treatment with methadone and buprenorphine has been shown to reduce the rate of heroin use, in the period immediately following release, in a small number of randomised controlled trials. It is widely recognised that continuity of care, of any form, is critical in avoiding DRDs. For problem drug users, packages of education, including information on the associated risks, treatments, and recognition of DRD after release from prison, are seen as a basic minimum requirement of the prison services. However, special protocols may be required for those drug-using prisoners who have a possibility of being released at short notice.

[Nutritional profile of foods offered and dietary intake in school canteens in Biscay]

INTRODUCTION

Nowadays the school canteen occupies a central place in the supply and in the nutritional education of the children in school age.

OBJECTIVES

To assess the nutritional adequacy of the school menus and the food intake of the children.

METHODS

1,500 trays were selected in six school dining rooms of Biscay. Dietary intake was evaluated by means of the technique of double weighed and visual estimation of the residues.

RESULTS

Evaluation of the menus: Macronutrients: carbohydrates 48%, proteins 20%, lipids 32%. Weekly offer: The first plate: vegetables 1.1; legumes 1.8; potatoes 0.4; pasta-rice 1.7. The second plate: meat 2.5; fish 1.4; eggs 0.6; precooked fried food 0.5. Garnish: potatoes 0.5; sauces 0.8; lettuce 1.7; cooked vegetables 1; no garnish 1. Dessert: fruit 2.8; dairy product 2; other 0.2. Significant changes have been observed in 4% of the menus. The vegetable garnish is not served in 40% of the occasions. 70% do not eat the vegetable garnish.

CONCLUSIONS

Though the theoretical offer of vegetables is appropriate, due to the fact that frequently the vegetables are not served in garnish and to that when they are served children do not eat them, their final intake is poor. The protein contribution to the diet is higher than the recommended. Meaningful changes take place often in the composition of the menus.

Rehabilitation of older patients: day hospital compared with rehabilitation at home. A randomised controlled trial

OBJECTIVES

To test the hypotheses that older people and their informal carers are not disadvantaged by home-based rehabilitation (HBR) relative to day hospital rehabilitation (DHR) and that HBR is less costly.

DESIGN

Two-arm randomised controlled trial.

SETTING

Four trusts in England providing both HBR and DHR.

PARTICIPANTS

Clinical staff reviewed consecutive referrals to identify subjects who were potentially suitable for randomisation according to the defined inclusion criteria.

INTERVENTIONS

Patients were randomised to receive either HBR or DHR.

MAIN OUTCOME MEASURES

The primary outcome measure was the Nottingham Extended Activities of Daily Living (NEADL) scale. Secondary outcome measures included the EuroQol 5 dimensions (EQ-5D), Hospital Anxiety and Depression Scale (HADS), Therapy Outcome Measures (TOMs), hospital admissions and the General Health Questionnaire (GHQ-30) for carers.

RESULTS

Overall, 89 subjects were randomised and 42 received rehabilitation in each arm of the trial. At the primary end point of 6 months there were 32 and 33 patients in the HBR and DHR arms respectively. Estimated mean scores on the NEADL scale at 6 months, after adjustment for baseline, were not significantly in favour of either HBR or DHR [DHR 30.78 (SD 15.01), HBR 32.11 (SD 16.89), p = 0.37; mean difference -2.139 (95% CI -6.870 to 2.592)]. Analysis of the non-inferiority of HBR over DHR using a 'non-inferiority' limit (10%) applied to the confidence interval estimates for the different outcome measures at 6 months' follow-up demonstrated non-inferiority for the NEADL scale, EQ-5D and HADS anxiety scale and some advantage for HBR on the HADS depression scale, of borderline statistical significance. Similar results were seen at 3 and 12 months' follow-up, with a statistically significant difference in the mean EQ-5D(index) score in favour of DHR at 3 months (p = 0.047). At the end of rehabilitation, a greater proportion of the DHR group showed a positive direction of change from their initial assessment with respect to therapist-rated clinical outcomes; however, a lower proportion of HBR patients showed a negative direction of change and, overall, median scores on the TOMs scales did not differ between the two groups. Fewer patients in the HBR group were admitted to hospital on any occasion over the 12-month observation period [18 (43%) versus 22 (52%)]; however, this difference was not statistically significant. The psychological well-being of patients' carers, measured at 3, 6 and 12 months, was unaffected by whether rehabilitation took place at day hospital or at home. As the primary outcome measure and EQ-5D(index) scores at 6 months showed no significant differences between the two arms of the trial, a cost-minimisation analysis was undertaken. Neither the public costs nor the total costs at the 6-month follow-up point (an average of 213 days' total follow-up) or the 12-month follow-up point (an average of 395 days' total follow-up) were significantly different between the groups.

CONCLUSIONS

Compared with DHR, providing rehabilitation in patients' own homes confers no particular disadvantage for patients and carers. The cost of providing HBR does not appear to be significantly different from that of providing DHR. Rehabilitation providers and purchasers need to consider the place of care in the light of local needs, to provide the benefits of both kinds of services. Caution is required when interpreting the results of the RCT because a large proportion of potentially eligible subjects were not recruited to the trial, the required sample size was not achieved and there was a relatively large loss to follow-up.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN71801032.

Retinol-binding protein 4 and nicotinamide phosphoribosyltransferase/visfatin in rat obesity models

Retinol-binding protein 4 (RBP4) and nicotinamide phosphoribosyltransferase/visfatin (Nampt/visfatin) are adipocyte-secreted proteins (adipokines) whose relevance to the metabolic syndrome and regulation in obesity remain controversial. Here, we tested the hypothesis that adipose tissue expression and circulating levels of these two adipokines are elevated in obesity by analyzing their changes in both a genetic and a diet-induced model of obesity in the rat (obese FA/ FA Zucker rats and Wistar rats fed a cafeteria diet, respectively). Compared with lean controls, obese FA/ FA rats were hyperleptinemic, hyperinsulinemic, and insulin resistant and had reduced RBP4 serum levels and mRNA levels in adipose depots, unchanged Nampt/visfatin serum levels, and reduced Nampt/visfatin mRNA levels selectively in the inguinal adipose depot. Cafeteria diet-induced obesity resulted in increased fed blood glucose levels, a variable degree of insulin resistance, unchanged serum Nampt/visfatin and RBP4 levels, and reduced mRNA levels of both adipokines in several adipose depots. Hence, increases in RBP4 or Nampt/visfatin do not accompany obesity and insulin resistance in the models examined.

Factors influencing the expression of dental extracellular matrix biomineralization

The forming tooth organ provides a number of opportunities to investigate the cellular and molecular biology of cell-mediated extracellular matrix (ECM) biomineralization. Regulatory processes associated with tooth formation are being investigated by identifying when and where cell adhesion molecules (CAMs), substrate adhesion molecules (SAMs), dentine phosphoprotein and enamel gene products are expressed during sequential developmental stages. In vitro organotypic culture studies in serumless, chemically-defined medium, have shown that instructive and permissive signalling are required for both morphogenesis and cytodifferentiation. Intrinsic developmental instructions (autocrine and paracrine factors) act independently of long-range hormonal or exogenous growth factors and mediate morphogenesis from the initiation of the dental lamina to the crown stages of tooth development. This review summarizes the results of studies using experimental embryology, recombinant DNA technology and immunocytology to elucidate mechanisms responsive to instructive epithelial-mesenchymal interactions associated with ameloblast differentiation, odontoblast differentiation, and dentine and enamel ECM biomineralization.

No evidence of the Chlamydia trachomatis variant in the UK

OBJECTIVES

The discovery of a variant strain of Chlamydia trachomatis (Ct) in Sweden has raised awareness of its possible undetected spread in the UK. The assays that fail to detect this variant are widely used in this country. This study aimed to determine if this variant is circulating in the UK.

METHOD

1,680 genital specimens tested negative by the Roche assays were retested by Aptima Combo2. Discordant results were sequenced to check for the deletion variant.

RESULTS

Of 1,680 specimens tested, 29 were candidates for sequencing: 16 were negative for the variant, 11 failed to amplify, and 2 were lost.

DISCUSSION

No Ct deletion variants were found in the UK. If it is circulating, then the prevalence is low (0-0.77%), but even a low level cannot be ignored. The system we describe is simple and suitable for rapid response and phasing of surveillance to match an unknown level of threat if other variants emerge.

PRODIACOR: A patient-centered treatment program for type 2 diabetes and associated cardiovascular risk factors in the city of Corrientes, Argentina

OBJECTIVE

To implement a controlled clinical trial (PRODIACOR) in a primary care setting designed 1) to improve type 2 diabetes care and 2) to collect cost data in order to be able to measure cost-effectiveness of three system interventions (checkbook of indicated procedures, patient/provider feedback and complete coverage of medications and supplies) and physician and/or patient education to improve psychological, clinical, metabolic and therapeutic indicators. All three Argentinean health subsectors (public health, social security and the private, prepaid system) are participants in the study. Patients of participating physicians were randomly selected and assigned to one of four groups: control, provider education, patient education, and provider/patient education; the system interventions were provided to all four groups.

BASELINE RESULTS

Mean BMI was 29.8 kg/m(2); most subjects had blood pressure, fasting glucose and total cholesterol above targets recommended by international standards. Only 1% had had microalbuminuria measured, 57% performed glucose self-monitoring, 37% had had an eye examination and 31% a foot examination in the preceding year. Ten percent, 26% and 73% of people with hyperglycemia, hypertension and dyslipidemia, respectively, were not on medications. Most patients treated with either insulin or oral antidiabetic agents were on monotherapy as were those treated for hypertension and dyslipidemia. WHO-5 questionnaire scores indicated that 13% of the subjects needed psychological intervention.

CONCLUSIONS

Baseline data show multiple deficiencies in the process and outcomes of care that could be targeted and improved by PRODIACOR intervention.

The intake of physiological doses of leptin during lactation in rats prevents obesity in later life

BACKGROUND

There is epidemiological evidence that perinatal nutritional factors may have long-term effects on obesity. Which nutrients or food components are involved in this programming mechanism are unknown. Breast milk contains leptin, a hormone that regulates food intake and energy expenditure, and previous studies in rats have shown that leptin orally administered during lactation exerts anorexigenic effects.

OBJECTIVE

To evaluate whether supplementation with physiological doses of oral leptin during lactation has long-term effects on body weight regulation.

DESIGN

A daily oral dose of leptin (equivalent to five times the amount of leptin ingested normally from maternal milk during the suckling period) or the vehicle was given to suckling male rats during lactation. Animals were fed after weaning with a normal fat (NF) or a high-fat (HF) diet. We followed body weight and food intake of animals until the age of 6 months, and measured the size of adipose tissue depots, the thermogenic capacity, the expression of leptin in the stomach and adipose tissues and the expression of two appetite-related peptides (neuropeptide Y (NPY) and proopiomelanocortin (POMC)), leptin receptor (OB-Rb) and suppressor of cytokine signalling 3 (SOCS-3) in the hypothalamus at the age of 6 months.

RESULTS

Leptin-treated animals had, in adulthood, lower body weight and fat content and ate fewer calories than their untreated controls. Unlike adipocitary leptin production, adult animals that were leptin-treated during lactation displayed higher gastric leptin production without changes in OB-Rb mRNA levels. In addition, in response to HF diet, leptin-treated animals (contrary to controls) showed lower hypothalamic NPY/POMC mRNA ratio. Hypothalamic OB-Rb mRNA levels decreased in control animals as an effect of HF diet feeding, but remained unchanged in leptin-treated animals; SOCS-3 mRNA levels were lower in leptin-treated animals than in their controls, both under normal or HF diet.

CONCLUSION

The animals that received leptin during lactation become more protected against fat accumulation in adult life and seem to be more sensitive to the short- and long-term regulation of food intake by leptin. Thus, leptin plays an important role in the earlier stages of neonatal life, as a component of breast milk, in the prevention of later obesity.

Resistin as a putative modulator of insulin action in the daily feeding/fasting rhythm

Resistin and adiponectin are adipokines with postulated opposite functions. Resistin has been related with insulin resistance in obesity, while adiponectin could be associated to higher insulin sensitivity. We have determined whether the production of these two adipokines during the day is related to the feeding rhythm in rats. Resistin mRNA levels in adipose tissue correlated positively with the gastric contents and serum insulin concentration, showing higher levels during the dark phase (period of the highest food intake), especially in the mesenteric depot, while levels decreased during the light phase. The diurnal pattern of resistin expression was not directly reflected in the circulating levels, but it showed a 6-h delay and correlated negatively with the gastric contents and serum insulin. Adiponectin expression followed an opposite pattern, not apparently related to feeding or insulin release, and not translated into changes in circulating levels. Moreover, considering that insulin stimulates resistin expression and that circulating resistin follows a contrary circadian pattern in comparison to insulin, resistin, apart from its role in the increased insulin resistance associated to obesity, could also act as a putative modulator of insulin in the daily feeding/fasting rhythm through a negative feedback regulation of its action.

Fitness and life-history traits of the two major mitochondrial DNA haplotypes of Drosophila subobscura

Mitochondrial DNA restriction site analyses on natural populations of Drosophila subobscura have proved the existence of two common, coexisting haplotypes (I and II), as well as a set of less frequent ones derived from them. To explain this distribution, experiments to date point practically to all possible genetic mechanisms being involved in the changes of gene frequencies (cytonuclear coadaptation, direct natural selection on mtDNA and genetic drift). In an attempt to find differences that help to understand the dynamics of these haplotypes and to detect the effect of selection, we measured certain fitness components and life-history traits (egg-larva and larva-adult viabilities and developmental times, longevity, resistance to desiccation and optimal density) of the two main haplotypes I and II when maintained in laboratory population cages. As a general trend, haplotype II showed a higher net fitness than haplotype I, which explains the superiority of haplotype II over haplotype I in experimental populations but not their coexistence in nature, where additional factors must be considered.

Linkage disequilibria between mtDNA haplotypes and chromosomal arrangements in a natural population of Drosophila subobscura

The association between mtDNA haplotypes and chromosomal arrangements in a natural population of Drosophila subobscura from Calvia (Balearic Islands, Spain) was studied in order to search for linkage disequilibria, in an attempt to explain the populational dynamics of the mtDNA haplotypes of this species in nature. The presence of Wolbachia was not detected. Two main haplotypes (I and II) were found, as well as a series of less common ones. The Tajima D-test seemed to indicate some kind of seasonal population bottleneck. An analysis of linkage disequilibrium and factorial analysis of correspondences detected an association between haplotype I and the J(ST) inversion and haplotype II and the J(1) inversion.

Efficient c-kit receptor-targeted gene transfer to primary human CD34-selected hematopoietic stem cells

We have previously reported effective gene transfer with a targeted molecular conjugate adenovirus vector through the c-kit receptor in hematopoietic progenitor cell lines. However, a c-kit-targeted recombinant retroviral vector failed to transduce cells, indicating the existence of significant differences for c-kit target gene transfer between these two viruses. Here we demonstrate that conjugation of an adenovirus to a c-kit-retargeted retrovirus vector enables retroviral transduction. This finding suggests the requirement of endosomalysis for successful c-kit-targeted gene transfer. Furthermore, we show efficient gene transfer to, and high transgene expression (66%) in, CD34-selected, c-kit(+) human peripheral blood stem cells using a c-kit-targeted adenovirus vector. These findings may have important implications for future vector development in c-kit-targeted stem cell gene transfer.

Improved radioiodination of biomolecules using exhaustive Chloramine-T oxidation

To improve standardization in analytical reagents we investigated Chloramine-T radioiodination (125I) of several biomolecules based on the use of a single amount of the oxidizing agent Chloramine-T as the limiting reagent being exhausted during the course of the reaction. Whenever the labeling yield resulted in less than one atom 125I/molecule, a second amount of the oxidizing agent was added. Thereafter, the integrity of the various biomolecules was assessed using radioimmunoassays, radioreceptor binding assays, or radioimmunometric assays. Purification yields were done by gel permeation (56% +/- 19%, n=230) or by precipitation with trichloroacetic acid (59% +/- 19%, n=230). Specific activity (117 +/- 61 MBq/nmol) and the degree of iodine incorporation (1.4 +/- 0.8 atoms of 125I/molecule) were achieved after 300 sec of incubation. A second addition of Chloramine-T resulted in an increased labeling yield of all biomolecules tested by a mean factor of 1.8 +/- 0.9. After the second addition of Chloramine-T, we observed for some biomolecules a significant (p<0.001) decreased effect in biological performance. In conclusion, the use of Chloramine-T as a limiting reagent resulted in molecules with appropriate immunological and biological performance. In general, tracers were minimally damaged and assessment of the shelf life as well as storing conditions showed the usefulness of the standardization of biomolecule labeling.

Residential rehabilitation for drug users: a review of 13 months' intake to a therapeutic community

BACKGROUND

Residential rehabilitation based on 'therapeutic community' treatment for drug users is a treatment option which is attractive to GPs and others referring drug users for treatment. Whilst there is evidence that maintenance-based programmes for drug users are effective, there have been fewer attempts to evaluate the effectiveness of abstinence-based programmes which are relatively more intensive and expensive interventions.

OBJECTIVE

This paper reports and evaluates the outcomes for 13 months' intake of 138 drug users to a residential community.

METHODS

We carried out a retrospective cohort study using existing clinical and residential record data. The setting is a residential rehabilitation centre run by the charity Phoenix House in Sheffield, UK, offering a 1-year programme for heroin addicts including community detoxification overseen by primary care specialist doctors and residential rehabilitation. Participants were all patients who entered treatment between 1 February 1998 and 28 February 1999 inclusive. An analysis was carried out of clinical records and other records kept by clinicians and staff at the centre. Outcome measures were numbers of days of retention in treatment and reasons for departure, categorized as completed treatment, planned or unplanned departure and expulsion from the programme. For patients who underwent in-house detoxification, a further outcome measure was whether or not detoxification was complete at discharge.

RESULTS

Heroin was the main drug of abuse in 85% of admissions. Mean length of time for which individuals had been drug dependent was 8 years (range 1.3-20.1 years). The mean length of stay was 80.2 days (range 1-394, 95% confidence interval 61.8-98.6). Thirty-four individuals (25%) completed 90 days or more. No association was found between length of stay and age, sex, route of administration, polydrug use, length of time addicted or age of first addiction. Sixty-five per cent of those who received in-house detoxification completed the detoxification period. When patients were classified as 'successes' or 'failures' by reason for departure from the programme, 94 (68.1%) were classified as failures and 18 (13.0%) as successes. Data were unavailable for 26 patients. Success was not associated with any characteristic at entry apart from being drug free as opposed to requiring detoxification (P = 0.048, chi-square = 6.06, df = 2).

CONCLUSION

This study shows overall low levels of programme completion and high levels of unplanned departure and eviction from the programme amongst these long-term drug users. On the other hand, the importance of abstinence for those who achieve it in residential rehabilitation should not be underestimated, nor should the possibility that long-term outcomes are influenced by the learning process involved in the intervention. It may be possible to operate better selection procedures in order to optimize outcomes.

Il-17 mobilizes peripheral blood stem cells with short- and long-term repopulating ability in mice

Autologous and allogeneic bone marrow transplantations have evolved as important cancer therapy modalities. For both indications, peripheral blood has been shown to have distinct advantages over bone marrow as the stem cell source. Cytokine combinations for mobilization have enhanced stem cell yield and accelerated engraftment. However, novel mobilizing agents and strategies are needed to further improve clinical outcomes. Within the donor graft, the dynamic equilibrium between T cells and stem cells critically influences engraftment and transplantation results. IL-17 is a cytokine produced almost exclusively from activated T cells. IL-17 was expressed in vivo with adenovirus technology. Here, proof-of-principle studies demonstrate that IL-17 effectively mobilizes hemopoietic precursor cells (CFU-granulocyte-erythrocyte-macrophage-monocyte, CFU-high proliferative potential) and primitive hemopoietic stem cells (Lin(-/low)c-kit(+)Sca1(+)). Moreover, mouse IL-17 adenovirus-mobilized peripheral blood stem cells rescued lethally irradiated mice. Bone marrow was found to be 45-75% of donor origin at 1 year. In secondary recipients, donor-derived bone marrow cells ranged from 45 to 95%. These data show that IL-17 mobilizes stem cells in mice with short- and long-term reconstituting capacity. Additional comparative studies are needed as well as studies in tumor models to refine distinct potential clinical applications for IL-17-mobilized peripheral blood stem cells.

Sexual dimorphism in age-related changes in UCP2 and leptin gene expression in subcutaneous adipose tissue in humans

The influence of age and gender on uncoupling protein 2 (UCP2) expression and its relationship with leptin expression in subcutaneous adipose tissue has been studied in humans. Samples of subcutaneous adipose tissue were obtained from 41 adult subjects (20 women and 21 men), with an age range of 28 to 84 years, and body mass index (BMI) of 19 to 36 Kgm(minus sign2). UCP2 and leptin mRNA expression was determined by northern blot. In women, both leptin and UCP2 expression in the subcutaneous adipose tissue increased significantly with age (r = 0.490 p < 0.05 and r = 0.475 p < 0.05, respectively). In men, in contrast, a negative correlation was found between leptin expression and age (r = minus sign0.678 p < 0.001), while no significant correlation was apparent between UCP2 expression and age (r = minus sign0.077). In addition, there was a positive correlation between UCP2 and leptin expression in women (r = 0.656 p < 0.01). These data show important gender dependent differences in the age-related changes in leptin and UCP2 expression in subcutaneous adipose tissue in humans.

Ontogenesis of leptin expression in different adipose tissue depots in the rat

Serum leptin levels and leptin mRNA expression by adipose tissue increase with age and are mainly associated with an increase in adiposity. Regional changes in both leptin production and fat distribution contribute to circulating leptin levels and may play a role in the regulation of body weight. a capacity that changes during development. Here, we have studied leptin mRNA expression in four different white adipose tissue depots (epididymal, retroperitoneal, mesenteric, inguinal; namely, EWAT, RWAT, MWAT, IWAT) and in interscapular brown adipose tissue (IBAT). We have also studied their relationship with lipid content and adiposity changes, together with serum leptin levels in male rats at different ages (18, 55, 93, 159, 212, 294 and 355 days). Serum leptin levels increased during development, reaching stable levels at the age of 7 months, and, as expected, were highly correlated with both the adiposity index (r=0.908, P<0.01) and body weight (r=0.906, P<0.01). Leptin mRNA expression also increased with age, following characteristic ontogenic patterns in every adipose tissue depot. The patterns were similar in EWAT and RWAT: leptin expression increased very rapidly during the first 55 days for EWAT and 3 months for RWAT, with a peak in the latter at 7 months, and high expression levels were retained for the rest of the study period. In IWAT and IBAT, leptin expression increased steadily during the 12-month period studied and was significantly lower than levels in EWAT and RWAT. Leptin expression in MWAT increased progressively with age to reach levels close to those of EWAT and RWAT in 10-month-old animals. The pattern of leptin expression in both EWAT and RWAT paralleled their lipid content, and leptin mRNA expression per unit of tissue lipid content was maintained high and constant from a very young age (about 2 and 3 months, respectively). However, the expression of mRNA for leptin (expressed per unit of tissue lipid concentration) in MWAT, IWAT and IBAT increased steadily during the whole period studied, without attaining the maximal levels observed in EWAT and RWAT. MWAT, IWAT and IBAT maintained their capacity to increase leptin mRNA expression in response to an additional accumulation of lipids. Our data demonstrate that there are regional-specific differences and different rates of increase of leptin gene expression within distinct depots of WAT and BAT. These changes cannot be uniquely explained by changes in adiposity or lipid content, implying that there are regional-specific regulatory mechanisms that may depend on the attenuation with age of the beta-adrenergic inhibitory signalling pathway upon leptin expression or on other factors.

Deaths from drugs of abuse in Sheffield, 1998: the role of prescribed medication

Characteristics of recent drug abuse-related deaths in the city of Sheffield were examined from the coroner's records. Almost all of those who died of poisoning from a drug of abuse were known to be dependent on heroin yet less than half were receiving treatment. Benzodiazepines were frequently detected alongside opiates during toxicology, the source of which was likely to be the deceased's own prescription.

Differential expression of genes for uncoupling proteins 1, 2 and 3 in brown and white adipose tissue depots during rat development

The different expression patterns of genes for uncoupling proteins (UCPs) 1, 2 and 3 (ucp1, ucp2 and ucp3) were studied in interscapular brown adipose tissue (BAT) and in four white adipose tissue (WAT) depots (epididymal, inguinal, mesenteric and retroperitoneal) in male rats of different ages (18 days-12 months). UCP mRNA expression levels were determined by Northern blotting. In BAT, there were high levels of expression of UCP1 and UCP3 mRNA, but no detectable levels of UCP2 mRNA. Both ucp1 and ucp3 followed a similar expression pattern with age, with high levels in suckling rats which decreased to 50% or less in rats just under 2 months old, declining thereafter until 5 months and then recovering with age. However, an additional peak of expression was observed for ucp3 at the age of 3 months. In WAT, ucp1 expression was rare: occasional expression was found for UCP1 mRNA in the retroperitoneal depot in suckling rats and in the epididymal and inguinal depots in suckling and mature adult rats. ucp2 and ucp3 had different developmental expression patterns, but these were similar for each gene in the different depots studied. UCP3 mRNA was highly expressed in rats soon after birth, it decreased until 3 months, and increased thereafter, except for the mesenteric WAT where ucp3 expression decreased until 7 months before recovering. The fact that changes with age of both ucp1 and ucp3 expression have a similar profile in BAT, which is also similar to the ucp3 and also ucp1 profiles in some WAT depots, might reflect a common regulatory pattern for the expression of these genes, and also a common function. In contrast to ucp1 and ucp3, ucp2 had a peak of expression at about 2 months, and lower expression at 3 months, suggesting different regulation and probably a different role for this UCP.

Current best practice for the health surveillance of enzyme workers in the soap and detergent industry

This study defines current best practice for the health surveillance of workers who are potentially exposed to enzymes in the manufacture of enzymatic detergent products. It is recommended that health surveillance is performed 6-monthly for the first 2 years and annually thereafter. The health surveillance programme should include a respiratory questionnaire to detect symptoms, assessment of lung function to detect pre-symptomatic changes and an immunological test to detect specific immunoglobulin E (IgE) to enzymes. The International Union Against Tuberculosis and Lung Disease respiratory questionnaire should be used since it has been validated extensively for detecting asthma. Operators should observe the American Thoracic Society performance criteria for spirometers and standardized procedures for conducting spirometry. Since current airborne monitoring techniques for enzymes do not detect short-duration peak exposures, the incidence of employee sensitizations remains the most reliable measure of the integrity of environmental control. The Pepys skin prick test has been validated as a sensitive, specific and practical test for detecting specific IgE to many inhalant allergens including enzymes. For newly sensitized workers, a multi-cause investigation should be conducted to identify potential sources of exposure. Group results of immunological test results assist in the evaluation of workplace control measures, and should be used to monitor the effectiveness of hygiene and engineering programmes and to help prioritize areas for improvement. Positive responses to a questionnaire or abnormal spirometry should be assessed further. Occupational asthma should be excluded in any case of adult-onset asthma that starts or deteriorates during working life. This is particularly important because an accurate diagnosis of occupational asthma with early avoidance of exposure to its cause can result in remission of symptoms and restoration of lung function.

Prolonged ethanol treatment enhances lipopolysaccharide/phorbol myristate acetate-induced tumor necrosis factor-alpha production in human monocytic cells

BACKGROUND

Ethanol (EtOH) is known to alter host immune responses and cytokine production. Acute EtOH exposure can suppress tumor necrosis factor (TNF)-alpha production, which attenuates pulmonary defense against infection. Previous studies in our laboratory show that acute EtOH inhibited TNF-alpha production by a posttranscriptional process, namely suppression of TNF-alpha-converting, enzyme-mediated, ectodomain shedding. However, chronic EtOH has been shown to augment TNF-alpha production, and this has been associated with EtOH-induced liver injury. To further characterize this paradoxical effect of EtOH on TNF-alpha production, we developed an in vitro model by using Mono Mac 6 cells, a human monocytic cell line.

METHODS

Mono Mac 6 cells were treated with EtOH (0-75 mM) for 1 to 7 days. TNF-alpha production was induced by lipopolysaccharide and phorbol myristate acetate and quantitated by enzyme-linked immunosorbent assay. Generation of reactive oxygen species (ROS) was assayed by using a specific fluorogenic reagent.

RESULTS

Acute EtOH initially inhibited lipopolysaccharide/phorbol myristate acetate-induced TNF-alpha production in Mono Mac 6 cells. However, during chronic EtOH exposure, this inhibition was reversed gradually over time. By day 6 after EtOH treatment, Mono Mac 6 cells demonstrated significant up-regulation of TNF-alpha production. Moreover, chronic EtOH induced the generation of ROS in these Mono Mac 6 cells. Scavenging ROS by Mn(III)tetrakis(1-methyl-4pyridyl)porphyrin pentachloride and N-acetyl-L-cysteine attenuated chronic EtOH-enhanced TNF-alpha production.

CONCLUSION

These results suggest that ROS induction is involved in EtOH-enhanced TNF-alpha production by monocytes. This study also provides insight into the mechanisms of alteration of TNF-alpha production in different EtOH exposure settings.

Reactive oxygen species mediate tumor necrosis factor alpha-converting, enzyme-dependent ectodomain shedding induced by phorbol myristate acetate

Ectodomain shedding of cell surface membrane-anchoring proteins is an important process in a wide variety of physiological events(1, 2). Tumor necrosis factor alpha (TNF-alpha) converting enzyme (TACE) is the first discovered mammalian sheddase responsible for cleavage of several important surface proteins, including TNF-alpha, TNF p75 receptor, L-selectin, and transforming growth factor-a. Phorbol myristate acetate (PMA) has long been known as a potent agent to enhance ectodomain shedding. However, it is not fully understood how PMA activates TACE and induces ectodomain shedding. Here, we demonstrate that PMA induces both reactive oxygen species (ROS) generation and TNF p75 receptor shedding in Mono Mac 6 cells, a human monocytic cell line, and l-selectin shedding in Jurkat T-cells. ROS scavengers significantly attenuated PMA-induced TNF p75 receptor shedding. Exogenous H2O2 mimicked PMA-induced enhancement of ectodomain shedding, and H2O2-induced shedding was blocked by TAPI, a TACE inhibitor. Furthermore, both PMA and H2O2 failed to cause ectodomain shedding in a cell line that lacks TACE activity. By use of an in vitro TACE cleavage assay, H2O2 activated TACE that had been rendered inactive by the addition of the TACE inhibitory pro-domain sequence. We presume that the mechanism of TACE activation by H2O2 is due to an oxidative attack of the pro-domain thiol group and disruption of its inhibitory coordination with the Zn++ in the catalytic domain of TACE. These results demonstrate that ROS production is involved in PMA-induced ectodomain shedding and implicate a role for ROS in other shedding processes.

Poly-L-lysine-based molecular conjugate vectors: a high efficiency gene transfer system for human progenitor and leukemia cells

BACKGROUND

Targeted, specific receptor mediated gene transfer is a major goal of gene therapy research to accomplish gene transfer exclusively to the desired cell population.

METHODS

First, the use of natural receptor for stem cell factor and transferrin receptor-targeted gene transfer using poly-L-lysine-based molecular conjugate vectors was evaluated in a panel of hematopoietic progenitor cell lines. Second, the ability of poly-L-lysine to enhance adenovirus mediated gene transfer efficiency was examined in different cell lines by using recombinant adenovirus-poly-L-lysine molecular conjugate conglomerates (recMCVEGFP).

RESULTS

Despite effective ligand internalization receptor, gene expression amplification in receptor positive cell lines was not uniformly observed. Therefore, using a poly-L-lysine-based, receptor-targeted vector, neither transferrin nor natural receptor for stem cell factor mediated gene transfer can be considered a universally applicable procedure that exclusively depends on the presence of receptors on the cell surface; rather, it is a cell specific phenomenon. In our model, poly-L-lysine is the major contributor for gene transfer to hematopoietic progenitor cells, mediating the initial vector-cell binding. Human progenitor cell lines are poorly transduceable with recombinant adenovirus vectors. This new poly-L-lysine-modified, adenovirus-based vector could overcome virus tropism restrictions and consistently achieve very high transduction efficiency (>90%) in cells otherwise refractory to adenovirus gene transfer.

CONCLUSIONS

Polylysine-based adenovirus vectors may have promise for situations in which high-efficiency gene transfer with transient high level transgene expression in hematopoietic cells is needed, such as leukemia vaccine protocols or for purging strategies in leukemia cell contaminated stem cell preparations.

What makes catchment management groups "tick"?

The work of catchment management groups throughout Australia represents a significant economic and social investment in natural resource management. Institutional structures and policies, the role of on-ground coordinators, facilitation processes, citizen participation and social capital are critical factors influencing the success of catchment management groups. From a participant-researcher viewpoint, this paper signposts research directions and themes that are being pursued from the participant/coordinator, catchment group, and lead government/non-government agency perspective on the influence of these factors on the success of a catchment management group in the Pumicestone Region of Southeast Queensland, Australia. Research directions, themes and discussion/reflection points for practitioners include--the importance of understanding milieu; motivation; success; having fun; "networking networks"; involvement of "nontraditional" stakeholders; development of stakeholder/participant partnerships; learning from other practitioners; methods of stakeholder/participant representation; evaluation; the need for guiding principles or philosophy; the equivalence of planning, implementation, evaluation, and resourcing; catchments as fundamental units of Nature; continuity of support for groups; recognising a new role for government; working with existing networks; and the need for an eclectic approach to natural resource management.