A bibliometric analysis of past and emergent trends in animal welfare science

A bibliometric analysis was undertaken to chart the development of animal welfare (AW) science as a whole, and of the individuals, organisations and countries that have had most academic impact to date. Publication data were collected from the Web of Science for the year range 1968–2017 and by-hand pre-processing of the data was undertaken to identify reviews and original research articles on AW. VOSviewer was used to create bibliometric networks. There has been a 13.3% annual growth in AW publications in the last 50 years with Animal Welfare and Applied Animal Behaviour Science the most frequent publishers of AW publications. Farm animals continue to dominate the subject of AW research and comparison of network visualisations for five key species suggested possible gaps in the research, such as relatively little emphasis on emotion research for some farm animals and little research on inherited disorders in dogs. However, keyword analysis indicated a recent broadening of AW findings to include other international contexts, such as conservation and sustainability. Highly cited review articles were grouped into five clusters with affective state (ie emotions, moods) and fish welfare the most recent topics. Almost all core authors of original research articles study farm animals, though in the last ten years other topics, such as consumer attitudes and wildlife, have emerged as highly cited areas of original research articles. Network analysis of organisations revealed the University of Bristol, UK as the main publisher of original research articles. Citation analysis indicated that many low-cited articles were originating from Germany and were published in German journals, suggesting that many worthwhile results and opinions on AW may be being missed by other researchers due to a language barrier. Several limitations of bibliometric analysis to generate an overview of AW science were identified, including the challenge of how to search and extract all the relevant publications in this discipline. In conclusion, animal welfare science is still in an exponential phase of growth which will bring opportunities, such as for the publication of new journals, but also challenges. The insights generated by this study suggest bibliometric analysis to be a useful addition to other approaches investigating the trends and concepts of animal welfare.

Correction: DUB3 and USP7 de-ubiquitinating enzymes control replication inhibitor Geminin: molecular characterization and associations with breast cancer

The final sentence of the Acknowledgements should be as follows: This work was supported by grants from Instituto de Salud Carlos III (BA15/00092), Spanish Ministry of Economy and Competitiveness/EU-ERDF (SAF2016-80626-R, SAF2013-49149-R, BFU2014-51672-REDC), Fundación CajaCanarias (AP2015/008) to RF, and the Australian National Health and Medical Research (NHMRC program grant to SRL and KKK (APP1017028).

Interval colorectal cancer after colonoscopy

INTRODUCTION AND AIMS

Interval colorectal cancer (iCRC) can occur due to missed lesions or to a newly developed lesion. The present study aimed to assess the iCRC rate and its characteristics in our population and find possible explanations.

MATERIALS AND METHODS

A retrospective study was conducted on patients with colorectal cancer (CRC) diagnosed between January 2011 and January 2015 at our department. Demographics, endoscopic data, and tumor characteristics (location, histology, staging) were collected. We identified patients diagnosed with CCR who underwent colonoscopy at our department in the previous 10years and presented the disease (iCRC) before the date of their next recommended exam. The cases of iCRC were characterized and compared with other CRC cases. Possible explanations for the appearance of iCRC were analyzed.

RESULTS

A total of 266 patients presented with CRC, 61.7% were men, and mean patient age was 70.7years. We identified 10 patients with iCRC: 6 were men, and mean patient age was 71.1years. Mean time for iCRC diagnosis after index colonoscopy was 3.5±1.84years. Tumor was located in the right colon in 50% of the patients with iCRC and in 24.5% of the patients without iCRC (P=.091). More patients with iCRC had a family history of CRC (50%) than the patients with reference CRC (3.1%) (P=.000).

CONCLUSIONS

In our case series, 3.76% of all CRC were iCRC. There were no statistically significant differences between patients with or without iCRC, with the exception of family history of CRC.

DUB3 and USP7 de-ubiquitinating enzymes control replication inhibitor Geminin: molecular characterization and associations with breast cancer

This corrects the article DOI: 10.1038/onc.2017.21.

DUB3 and USP7 de-ubiquitinating enzymes control replication inhibitor Geminin: molecular characterization and associations with breast cancer

Correct control of DNA replication is crucial to maintain genomic stability in dividing cells. Inappropriate re-licensing of replicated origins is associated with chromosomal instability (CIN), a hallmark of cancer progression that at the same time provides potential opportunities for therapeutic intervention. Geminin is a critical inhibitor of the DNA replication licensing factor Cdt1. To properly achieve its functions, Geminin levels are tightly regulated through the cell cycle by ubiquitin-dependent proteasomal degradation, but the de-ubiquitinating enzymes (DUBs) involved had not been identified. Here we report that DUB3 and USP7 control human Geminin. Overexpression of either DUB3 or USP7 increases Geminin levels through reduced ubiquitination. Conversely, depletion of DUB3 or USP7 reduces Geminin levels, and DUB3 knockdown increases re-replication events, analogous to the effect of Geminin depletion. In exploring potential clinical implications, we found that USP7 and Geminin are strongly correlated in a cohort of invasive breast cancers (P<1.01E-08). As expected, Geminin expression is highly prognostic. Interestingly, we found a non-monotonic relationship between USP7 and breast cancer-specific survival, with both very low or high levels of USP7 associated with poor outcome, independent of estrogen receptor status. Altogether, our data identify DUB3 and USP7 as factors that regulate DNA replication by controlling Geminin protein stability, and suggest that USP7 may be involved in Geminin dysregulation during breast cancer progression.

RNF168 cooperates with RNF8 to mediate FOXM1 ubiquitination and degradation in breast cancer epirubicin treatment

The forkhead box M1 (FOXM1) transcription factor has a central role in genotoxic agent response in breast cancer. FOXM1 is regulated at the post-translational level upon DNA damage, but the key mechanism involved remained enigmatic. RNF168 is a ubiquitination E3-ligase involved in DNA damage response. Western blot and gene promoter-reporter analyses showed that the expression level and transcriptional activity of FOXM1 reduced upon RNF168 overexpression and increased with RNF168 depletion by siRNA, suggesting that RNF168 negatively regulates FOXM1 expression. Co-immunoprecipitation studies in MCF-7 cells revealed that RNF168 interacted with FOXM1 and that upon epirubicin treatment FOXM1 downregulation was associated with an increase in RNF168 binding and conjugation to the protein degradation-associated K48-linked polyubiquitin chains. Consistently, RNF168 overexpression resulted in an increase in turnover of FOXM1 in MCF-7 cells treated with the protein synthesis inhibitor cycloheximide. Conversely, RNF168, knockdown significantly enhanced the half-life of FOXM1 in both absence and presence of epirubicin. Using a SUMOylation-defective FOXM1-5x(K>R) mutant, we demonstrated that SUMOylation is required for the recruitment of RNF168 to mediate FOXM1 degradation. In addition, clonogenic assays also showed that RNF168 mediates epirubicin action through targeting FOXM1, as RNF168 could synergise with epirubicin to repress clonal formation in wild-type but not in FOXM1-deficient mouse embryo fibroblasts (MEFs). The physiological relevance of RNF168-mediated FOXM1 repression is further emphasized by the significant inverse correlation between FOXM1 and RNF168 expression in breast cancer patient samples. Moreover, we also obtained evidence that RNF8 recruits RNF168 to FOXM1 upon epirubicin treatment and cooperates with RNF168 to catalyse FOXM1 ubiquitination and degradation. Collectively, these data suggest that RNF168 cooperates with RNF8 to mediate the ubiquitination and degradation of SUMOylated FOXM1 in breast cancer genotoxic response.

OTUB1 inhibits the ubiquitination and degradation of FOXM1 in breast cancer and epirubicin resistance

The forkhead transcription factor FOXM1 has a key role in DNA damage response, and its deregulated overexpression is associated with genotoxic drug resistance in breast cancer. However, little is known about the posttranslational mechanisms by which FOXM1 expression is regulated by genotoxic agents and how they are deregulated in resistant cells. Initial co-immunoprecipitation studies verified previous proteomic analysis finding that the OTUB1 is a novel FOXM1-interacting protein. Western blot analysis showed that both OTUB1 and FOXM1 expression reduced upon genotoxic agent treatment in MCF-7 cells, but remained relatively constant in resistant cells. FOXM1 expression reduced upon OTUB1 depletion by siRNA and increased with OTUB1 overexpression in MCF-7 cells, arguing that OTUB1 positively regulates FOXM1 expression. In agreement, co-immunoprecipitation experiments demonstrated that FOXM1 expression is associated with OTUB1 binding but inversely correlates with conjugation to the protein degradation-associated Lys-48-linked ubiquitin-chains. Overexpression of wild-type (WT) OTUB1, but not the OTUB1(C91S) mutant, disrupted the formation of Lys48-linked ubiquitin-conjugates on FOXM1. Importantly, knockdown of OTUB1 by siRNA resulted in an increase in turnover of FOXM1 in MCF-7 cells treated with the protein synthesis inhibitor cycloheximide, whereas overexpression of WT OTUB1, but not the OTUB1(C91S) mutant, significantly enhances the half-life of FOXM1. In addition, proliferative and clonogenic assays also show that OTUB1 can enhance the proliferative rate and epirubicin resistance through targeting FOXM1, as OTUB1 has little effect on FOXM1-deficient cells. The physiological relevance of the regulation of FOXM1 by OTUB1 is further underscored by the significant correlations between FOXM1 and OTUB1 expression in breast cancer patient samples. Cox-regression survival analysis indicates that OTUB1 overexpression is linked to poorer outcome in particular in patients treated with chemotherapy. Collectively, these data suggest that OTUB1 limits the ubiquitination and degradation of FOXM1 in breast cancer and has a key role in genotoxic agent resistance.

Myocardial ischemia during endoscopic retrograde cholangiopancreatography - A real problem?

AIM

The occurrence of silent myocardial ischemia during endoscopic retrograde cholangiopancreatography (ERCP) has been documented, but its clinical significance remains unknown. The aims of this study were to investigate the incidence and risk factors of myocardial ischemia during ERCP, to determine the presence or absence of permanent myocardial injury and to evaluate if deep sedation with propofol had a positive effect on myocardial ischemia during ERCP.

METHODS

Ambulatory ST-segment monitoring from 30 minutes prior to 4 hours after ERCP was obtained on 50 patients. A deep sedation was performed with intravenous propofol administered by anesthesiologist. Changes in vital signs during ERCP, pre and postprocedural 12-lead ECG examination and cardiac enzymes were evaluated.

RESULTS

Silent cardiac ischemia occurred only in one patient (2%) during ERCP. This 64-year-old patient did not develop hypoxemia, tachycardia or hypotension periods during the exam. None of the patients developed cardiac enzymes or postprocedural electrocardiographic changes. Thirty seven (74%) patients suffered rhythm changes.

CONCLUSION

Although rhythm disturbances were common, silent myocardial ischemia during ERCP was rare (2%) and without clinical relevance. In prolonged or complex therapeutic procedures, like ERCP, deep sedation with propofol performed by trained personnel is associated with reduced cardiac complications.

[Health-economic burden of Parkinson's disease in Portugal: a cohort study]

INTRODUCTION

Parkinson's disease (PD) is a common neurodegenerative disorder with a considerable socioeconomic burden. Health-economic evaluations of PD in the Southern European countries are limited.

AIM

To evaluate the costs of PD in an outpatient cohort in Portugal.

PATIENTS AND METHODS

49 consecutive PD patients were recruited at the neurological outpatient clinic of the University of Lisbon between October 2004 and December 2005. Clinical status was evaluated using the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr stages. Costs were assessed from the societal perspective using health-economic questionnaires. Human capital approach was used to estimate indirect costs. Health-related quality of life was evaluated by means of the EQ-5D.

RESULTS

Direct costs were 2,717 euros (95% CI = 1,147-3,351) per patient for a six-month period. Main contributors to the direct costs included drugs (544 euros; 95% CI = 426-6,940) and hospitalizations (690 euros; 95% CI = 229-1,944). Indirect costs amounted to 850 euros (95% CI = 397-1,529), whereas patient expenditures constituted 12% of direct costs. Assistance by family and other relatives played a major role. In general, costs were lower than in other Western countries.

CONCLUSIONS

The economic burden of PD in Portugal is considerable. Important cost components include medications and hospitalizations. More research is needed in order to describe a comprehensive health service patterns in Portugal and to guide health policy decisions more effectively.

Murine model of Clostridium difficile infection with aged gnotobiotic C57BL/6 mice and a BI/NAP1 strain

The increased incidence and severity of Clostridium difficile infection (CDI) in older adults (age, ≥65 years) corresponds with the emergence of the BI/NAP1 strain, making elucidation of the host immune response extremely important. We therefore infected germ-free C57BL/6 mice aged 7-14 months with a BI/NAP1 strain and monitored the mice for response. Infected mice were moribund 48-72 h after infection and developed gross and histological cecitis and colitis and elevated concentrations of keratinocyte chemoattractant, interleukin 1β, monocyte chemotactic protein 1, and granulocyte colony-stimulating factor and decreased levels of interferon γ, interleukin 12 p40, interleukin 12 p70, and interleukin 10 compared with controls. We conclude that aged, germ-free C57BL/6 mice are susceptible to fulminant CDI from a BI/NAP1 strain and represent a novel model to further elucidate the host immune response to acute CDI.

Exploring the knowledge contained in neuroimages: statistical discriminant analysis and automatic segmentation of the most significant changes

OBJECTIVE

The aim of this article is to propose an integrated framework for extracting and describing patterns of disorders from medical images using a combination of linear discriminant analysis and active contour models.

METHODS

A multivariate statistical methodology was first used to identify the most discriminating hyperplane separating two groups of images (from healthy controls and patients with schizophrenia) contained in the input data. After this, the present work makes explicit the differences found by the multivariate statistical method by subtracting the discriminant models of controls and patients, weighted by the pooled variance between the two groups. A variational level-set technique was used to segment clusters of these differences. We obtain a label of each anatomical change using the Talairach atlas.

RESULTS

In this work all the data was analysed simultaneously rather than assuming a priori regions of interest. As a consequence of this, by using active contour models, we were able to obtain regions of interest that were emergent from the data. The results were evaluated using, as gold standard, well-known facts about the neuroanatomical changes related to schizophrenia. Most of the items in the gold standard was covered in our result set.

CONCLUSIONS

We argue that such investigation provides a suitable framework for characterising the high complexity of magnetic resonance images in schizophrenia as the results obtained indicate a high sensitivity rate with respect to the gold standard.

Effects of different forms of exercise on post inhibitory rebound and unwanted behaviour in stabled horses

REASONS FOR PERFORMING STUDY

It is unknown if different locomotor activities are equally effective at meeting the stabled horse's need for exercise and if they attenuate unwanted behaviour.

HYPOTHESIS

Alternative forms of exercise influence the intensity of locomotor activities during a period of turn-out (the so-called rebound effect) and the occurrence of unwanted or undesirable activities during standard handling situations.

METHOD

Twenty-four horses kept in stables were randomly assigned to one of 4 exercise regimes (walker, treadmill, turn-out and riding) for 4 consecutive days. Because these forms of exercise provide additional environmental stimulation, beyond that provided by exercise, each horse served as its own control in 4 corresponding (no exercise) control treatments presented in a balanced order. Unwanted behaviour was tested by taking horses to weighing scales and loading and unloading them onto a 4-horse float by an experienced handler and the rebound effect was tested by releasing them into a large arena for a period of 15 min at the end of the exercise and control treatments.

RESULTS

Locomotor activities made up a large part of behaviour in the large arena following control treatments and all exercise regimes were sufficient to reduce the intensity of walking (P < 0.05), trotting (P < 0.01) and cantering (P < 0.001) on release into a large arena. Exercise regime reduced the number of bucks (P < 0.01) and rolling (P < 0.05) during rebound tests suggesting that turn-out was having a stronger effect than the other 3 exercise regimes. Exercise regimes significantly reduced the amount of unwanted behaviour and the number of commands given by the handler during weighing (P < 0.05) but had no effect on these behaviours during loading onto a float.

CONCLUSION

Providing stabled horses with one hour/day of exercise on a walker, treadmill, turn-out or by being ridden are all effective at allowing expression of locomotor activities in stabled horses.

POTENTIAL RELEVANCE

Providing stabled horses with regular exercise is likely to provide positive effects on horse welfare, training ability and handler safety.

Cleavage and degradation of Claspin during apoptosis by caspases and the proteasome

Apoptosis plays a crucial role in development and tissue homeostasis. Some key survival pathways, such as DNA damage checkpoints and DNA repair, have been described to be inactivated during apoptosis. Here, we describe the processing of the human checkpoint protein Claspin during apoptosis. We observed cleavage of Claspin into multiple fragments in vivo. In vitro cleavage with caspases 3 and 7 of various fragments of the protein, revealed cut sites near the N- and C-termini of the protein. Using mass spectrometry, we identified a novel caspase cleavage site in Claspin at Asp25. Importantly, in addition to cleavage by caspases, we observed a proteasome-dependent degradation of Claspin under apoptotic conditions, resulting in a reduction of the levels of both full-length Claspin and its cleavage products. This degradation was not dependent upon the DSGxxS phosphodegron motif required for SCF(beta-TrCP)-mediated ubiquitination of Claspin. Finally, downregulation of Claspin protein levels by short interfering RNA resulted in an increase in apoptotic induction both in the presence and absence of DNA damage. We conclude that Claspin has antiapoptotic activity and is degraded by two different pathways during apoptosis. The resulting disappearance of Claspin from the cells further promotes apoptosis.

Pre- and post-hatching effects of corticosterone treatment on behavior of the domestic chick

We investigated the effect of 60 ìg of corticosterone administered to domestic chicks either before or after hatching on the behavioral response to isolation in a novel arena and performance in a task involving the simultaneous identification of food and detection of a predator (overhead silhouette of a hawk moving overhead). Following release into a novel arena, chicks treated with corticosterone at 18 days of incubation emitted more distress vocalizations. In contrast, no difference in the number of vocalizations was found between chicks treated with corticosterone at day 1 post-hatching and controls. Behavior in the home cages was generally similar across treatments, though chicks treated with corticosterone at 18 days of incubation slept more than control chicks. While searching for grain against a background of pebbles, chicks treated with corticosterone at embryonic day 18, but not chicks treated on day 1 post-hatching, took longer to detect the overhead image of a predator than did controls. Corticosterone treatment at both ages increased the rate of pecking at grains and pebbles. Our findings support work on other birds indicating that corticosterone treatment during incubation influences stress reactivity. The impairment in predator detection in chicks treated with corticosterone on day 18 of incubation appears to be caused by the known effects of corticosterone treatment at this age in preventing the development of lateralization of the thalamofugal visual projections. This further supports the hypothesis that brain lateralization provides an advantage in performing more than one task simultaneously.

Endotoxin stress responses in chickens from different genetic lines. 1. Sickness, behavioral, and physical responses

Genetic variation in response to lipopolysaccharide (LPS) challenge was studied in chicken lines divergently selected for high (HGPS) and low (LGPS) group productivity and survivability resulting from cannibalism and flightiness in colony cages and in a Dekalb XL (DXL) commercial line. Six-week-old chicks were randomly assigned to control or experimental groups and were injected intravenously with Escherichia coli LPS (5 mg/kg of BW) or distilled saline (control). Sickness responses were measured at 6, 12, 24, 48, and 72 h following injection (n = 10 at each point in time for each line). Although LPS induced widespread sickness symptoms in all of the treated chicks, the reactions were in a genotypic- and phenotypic-specific manner. Compared with LGPS and DXL chicks, HGPS chicks had acute, transient behavioral and physical changes with less effect on BW gain, organ development, and core temperature, which were in the order HGPS < DXL < LGPS. The effects of heritable factors and LPS challenge on the differential responses among the present lines may reflect each line's unique adaptability to stress and resistance to infection and inflammation. The results suggested that the present chicken lines may provide a valuable animal model for investigating the effects of genetic-environmental interactions on the behavioral and physiological homeostasis in response to stress and disease.

Behaviour and welfare of individual laying hens in a non-cage system

1. A leg band containing a transponder was fitted to 80 birds in a perchery containing 1,000 birds. 2. The transponder emitted a unique identification number when a bird walked on one of 8 flat antennae on the floor. The recording apparatus was used to measure the amount of time that each of the tagged birds spent on the slatted and littered areas in a 6-week period. 3. Some birds spent long periods of time on the slats, possibly as a means of avoiding repeated attacks. Duration on the slats was greatest in birds with the worst (as opposed to better) feather scores of the head, back and tail regions. 4. Birds that spent long periods on the slats were lighter than other birds at both 39 weeks of age and 72 weeks of age and had greater back, head and tail feather damage, consistent with these birds being victims of pecking. 5. Tagged birds received a social avoidance test outside the perchery at 39 weeks of age, which suggested that birds retreated to the slats in response to pecks rather than just to close proximity to other birds. 6. The failure to find that duration on the slats was related to anatomical indicators of stress (liver, spleen and bursa of Fabricius) suggests that retreating to the slats following pecking attenuates physiological stress responses. 7. We conclude that the provision of areas where birds in a large group can avoid pecking may improve the welfare of a minority of victimised birds.

Development of furnished cages for laying hens

1. A 3-year trial was carried out of cages for laying hens, occupying a full laying house. The main cage designs used were 5000 cm2 in area, 50 cm high at the rear and furnished with nests and perches. F cages had a front rollaway nest at the side, lined with artificial turf. FD cages also had a dust bath containing sand over the nest. H cages had two nest hollows at the side, one in front of the other. They were compared with conventional cages 2500 cm2 in area and 38 cm high at the rear. 2. Cages were stocked with from 4 to 8 ISA Brown hens per cage, resulting in varied allowances of area, feeder and perch per bird. No birds were beak trimmed. In F and FD cages two further treatments were applied: nests and dust baths were sometimes fitted with gates to exclude birds from dust baths in the morning and from both at night; elevated food troughs, with a lip 33 cm above the cage floor, were compared with standard troughs. 3. Management of the house was generally highly successful, with temperature control achieved by ventilation. Egg production was above breeders' standards and not significantly affected by cage design. More eggs per bird were collected when there were fewer birds per cage but food consumption also then tended to be higher. 4. The number of downgraded eggs was variable, with some tendency for more in furnished cages. Eggs laid in dust baths were often downgraded. Those laid at the back of the cage were frequently dirty because of accumulation of droppings. H nests were unsuccessful, with less than 50% of eggs laid in the nest hollows. However, up to 93% of eggs were laid in front rollaways, and few of these were downgraded. 5. Feather and foot damage were generally less in furnished than in conventional cages, greater where there were more birds per cage. With an elevated food trough there was less feather damage but more overgrowth of claws. In year 2, mortality was greater in cages with more birds. 6. Pre-laying behaviour was mostly settled in front rollaway nests. Dust baths were used more for pecking and scratching than for dust bathing. Comfort behaviour was more frequent in furnished cages than conventional, although still not frequent. Locomotion was strongly affected by number of birds per cage or by space per bird, being reduced by crowding. Most birds perched at night except in one treatment providing only 10.7 cm perch per bird. 7. Behaviour was more unrestricted and varied, and physical condition was better, in furnished than in conventional cages. However, egg production will cost more in furnished cages, partly because more eggs are downgraded. Dust baths must be fitted with gates that the birds cannot open from outside, but gates for nest boxes were found unnecessary. If a low perch is fitted it must be far enough from the back of the cage for birds to walk there. 8. Where there was less space per bird (more birds per cage) than the requirements in the 1999 European Commission Directive on laying hens, there were: fewer eggs per hen, but still above the breeders' target; lower food consumption; more feather and foot damage, but less than in conventional cages; higher mortality in one trial out of three; less freedom of movement. However, the results were still very good even with 8 birds per cage, and support the principle that furnished cages provide an acceptable way of protecting the welfare of laying hens.

The 5S rDNA of mussels Mytilus galloprovincialis and M. edulis: sequence variation and chromosomal location

The 5S ribosomal DNA of the mussels Mytilus galloprovincialis and M. edulis was amplified by PCR using contiguous primers. The most general 5S rDNA amplification pattern consisted of several products in both mussels. Two main PCR products of about 250 bp and 760 bp were cloned and sequenced, revealing two classes of 5S rDNA units. These were characterized as containing an identical coding region of 119 bp but with highly divergent spacers. Clones of each unit type exhibited minimal differences except those of the large unit of M. edulis. The sequences analysed of the two mussels possess the same coding region and only six fixed base changes on the spacers. FISH, carried out with specific probes, consistently showed hybridization signals on the largest metacentric pair (two differentiated sites) and with variable frequency on two other metacentric pairs (one site on each pair). Differences in the 5S rDNA distribution between both mussels were not found. In M. edulis, chromosomes carrying 18S-28S rDNA were also identified by FISH. These correspond to two submetacentric-subtelocentric pairs, as was previously reported in M. galloprovincialis, demonstrating that the two rDNA multigene families are located on different chromosome pairs in these mussels.

Direct association of Bloom's syndrome gene product with the human mismatch repair protein MLH1

Bloom's syndrome (BS) is a rare genetic disorder characterised by genomic instability and cancer susceptibility. BLM, the gene mutated in BS, encodes a member of the RecQ family of DNA helicases. Here, we identify hMLH1, which is involved in mismatch repair (MMR) and recombination, as a protein that directly interacts with BLM both in vivo and in vitro, and that the two proteins co-localise to discrete nuclear foci. The interaction between BLM and hMLH1 appears to have been evolutionarily conserved, as Sgs1p, the Saccharomyces cerevisiae homologue of BLM, interacts with yeast Mlh1p. However, cell extracts derived from BS patients show no obvious defects in MMR compared to wild-type- and BLM-complemented BS cell extracts. We conclude that the hMLH1-BLM interaction is not essential for post-replicative MMR, but, more likely, is required for some aspect of genetic recombination.

Cleavage of the Bloom's syndrome gene product during apoptosis by caspase-3 results in an impaired interaction with topoisomerase IIIalpha

In higher eukaryotes, the integration of signals triggered in response to certain types of stress can result in programmed cell death. Central to these events is the sequential activation of a cascade of proteinases known as caspases. The final activated effector caspases of this cascade digest a number of cellular proteins, in some cases increasing their enzymatic activity, in others destroying their function. Of the proteins shown to be targets for caspase-mediated proteolysis, a surprisingly large proportion are proteins involved in the signalling or repair of DNA damage. Here we investigate whether BLM, the product of the gene mutated in Bloom's syndrome, a human autosomal disease characterised by cancer predisposition and sunlight sensitivity, is cleaved during apoptosis. BLM interacts with topoisomerase IIIalpha and has been proposed to play an important role in maintaining genomic integrity through its roles in DNA repair and replication. We show that BLM is cleaved during apoptosis by caspase-3 and reveal that the main cleavage site is located at the junction between the N-terminal and central helicase domains of BLM. Proteolytic cleavage by caspase-3 produces a 120 kDa fragment, which contains the intact helicase domain and three smaller fragments, the relative amounts of which depend on time of incubation with caspase-3. The 120 kDa fragment retains the helicase activity of the intact BLM protein. However, its interaction with topoisomerase IIIalpha is severely impaired. Since the BLM-topoisomerase interaction is believed to be necessary for many of the replication and recombination functions of BLM, we suggest that caspase-3 cleavage of BLM could alter the localisation and/or function of BLM and that these changes may be important in the process of apoptosis.

Fragmentation of carbohydrate anomeric alkoxy radicals. synthesis of polyhydroxy piperidines and pyrrolidines related to carbohydrates

Imino sugars of the piperidine and pyrrolidine types can be specifically obtained when protected 5-amino-5-deoxyfuranopentoses, 5-amino-5-deoxyfuranohexoses, 6-amino-6-deoxyfuranohexoses, and 6-amino-6-deoxypyranohexoses undergo a tandem alkoxy radical beta-fragmentation-intramolecular cyclization reaction. The reaction is promoted by the system: iodosylbenzene-iodine under mild conditions. The tert-butoxycarbonyl, benzyloxycarbonyl, and diphenylphosphinoyl radicals have been studied as amino-protecting groups. Using this methodology, polyhydroxylated pyrrolidines of the D-erythrofuranoses 34 and 35, D-threofuranose 36, L-xylofuranose 42, and D-arabinofuranose 43 series and polyhydroxylated piperidines of the D-arabinopyranose type 37 and 38 were obtained.

Expression and nuclear localization of BLM, a chromosome stability protein mutated in Bloom's syndrome, suggest a role in recombination during meiotic prophase

Bloom's syndrome (BS) is a recessive human genetic disorder characterized by short stature, immunodeficiency and elevated risk of malignancy. BS cells have genomic instability and an increased frequency of sister chromatid exchange. The gene mutated in BS, BLM, encodes a 3′-5′ helicase (BLM) with homology to bacterial recombination factor, RecQ. Human males homozygous for BLM mutations are infertile and heterozygous individuals display increased frequencies of structural chromosome abnormalities in their spermatozoa. Also, mutations in the Saccharomyces cerevisiae homolog of BLM, Sgs1, cause a delay in meiotic nuclear division and a reduction in spore viability. These observations suggest that BLM may play a role during meiosis. Our antibodies raised against the C terminus of the human protein specifically recognize both mouse and human BLM in western blots of cell lines and in successive developmental stages of spermatocytes, but fail to detect BLM protein in a cell line with a C-terminally truncated protein. BLM protein expression and location are detected by immunofluorescence and immunoelectron microscopy as discrete foci that are sparsely present on early meiotic prophase chromosome cores, later found abundantly on synapsed cores, frequently in combination with the recombinases RAD51 and DMC1, and eventually as pure BLM foci. The colocalization of RAD51/DMC1 with BLM and the statistically significant excess of BLM signals in the synapsed pseudoautosomal region of the X-Y chromosomes, which is a recombinational hot spot, provide indications that BLM protein may function in the meiotic recombination process.

Effect of experience of occlusion events on the domestic chick's strategy for locating a concealed imprinting object

We investigated how positional and directional cues affected the way single domestic chicks, Gallus gallus domesticus, searched for a concealed imprinting object. The chicks were 4 or 12 days of age and had been reared in enriched pens that allowed them to move out of sight of the imprinting object, or control pens that did not. In experiment 1, 44 chicks viewed a positional cue, which was a stationary imprinting object placed for 1 min in front of one of two possible hiding locations (each concealing an identical imprinting object) either to the left or right of the chick. When released, chicks moved towards, and spent more time in, the side in which the positional cue had been presented. We presented a further 44 chicks with a directional cue, which involved an imprinting object moving from near one possible hiding location towards the other and its occlusion midway between the two possible hiding locations. When released, chicks moved towards, and spent more time in, the opposite side to that indicated by the visible direction of movement of the imprinting object. Additionally, chicks reared in enriched pens spent more time in the side in which the imprinting object was seen than chicks reared in control pens. We examined the relative influence of positional and directional cues in experiment 2, by providing both cues sequentially to 88 chicks. Chicks spent more time in the positional cue side, when the directional cue offered complementary information, but no side preference was found when cues provided contradictory information. We conclude that in this study, orientation towards a concealed object was based on previous spatial location alone, with little influence from the temporal aspects of the presentation such as movement before occlusion or last-seen location. We discuss the possibility that chicks imprinting on a stationary object develop a strategy for locating a concealed social stimulus that is unrepresentative of chicks reared by a hen. Copyright 1999 The Association for the Study of Animal Behaviour.

The association of ATR protein with mouse meiotic chromosome cores

The ATR (ataxia telangiectasia- and RAD3-related) protein is present on meiotic prophase chromosome cores and paired cores (synaptonemal complexes, SCs). Its striking characteristic is that the protein forms dense aggregates on the cores and SCs of the last chromosomes to pair at the zygotene-pachytene transition. It would appear that the ATR protein either signals delays in pairing or it is directly involved in the completion of the pairing phase. Atm-deficient spermatocytes, which are defective in the chromosome pairing phase, accumulate large amounts of ATR. The behaviour of ATR at meiotic prophase sets it apart from the distribution of the RAD51/DMC1 recombinase complex and our electron microscope observations confirm that they do not co-localize. We failed to detect ATM in association with cores/SCs and we have reported elsewhere that RAD1 protein does not co-localize with DMC1 foci. The expectation that putative DNA-damage checkpoint proteins. ATR, ATM and RAD1, are associated with RAD51/DMC1 recombination sites where DNA breaks are expected to be present, is therefore not supported by our observations.

Human and mouse homologs of Schizosaccharomyces pombe rad1(+) and Saccharomyces cerevisiae RAD17: linkage to checkpoint control and mammalian meiosis

Preventing or delaying progress through the cell cycle in response to DNA damage is crucial for eukaryotic cells to allow the damage to be repaired and not incorporated irrevocably into daughter cells. Several genes involved in this process have been discovered in fission and budding yeast. Here, we report the identification of human and mouse homologs of the Schizosaccharomyces pombe DNA damage checkpoint control gene rad1(+) and its Saccharomyces cerevisiae homolog RAD17. The human gene HRAD1 is located on chromosome 5p13 and is most homologous to S. pombe rad1(+). This gene encodes a 382-amino-acid residue protein that is localized mainly in the nucleus and is expressed at high levels in proliferative tissues. This human gene significantly complements the sensitivity to UV light of a S. pombe strain mutated in rad1(+). Moreover, HRAD1 complements the checkpoint control defect of this strain after UV exposure. In addition to functioning in DNA repair checkpoints, S. cerevisiae RAD17 plays a role during meiosis to prevent progress through prophase I when recombination is interrupted. Consistent with a similar role in mammals, Rad1 protein is abundant in testis, and is associated with both synapsed and unsynapsed chromosomes during meiotic prophase I of spermatogenesis, with a staining pattern distinct from that of the recombination proteins Rad51 and Dmc1. Together, these data imply an important role for hRad1 both in the mitotic DNA damage checkpoint and in meiotic checkpoint mechanisms, and suggest that these events are highly conserved from yeast to humans.

Assessment of pre-laying motivation in the domestic hen using social interaction

While much is known about the hormonal basis of pre-laying behaviour of domestic hens, Gallus gallus domesticuslittle is known about how the behaviour is initiated or how changes in this behaviour occur. An experiment was conducted in which hens had to overcome an aversive task, during the course of pre-laying behaviour, in order to reach a nest site. Twelve hens were tested in four treatments presented as a Latin square design. The test arena was arranged such that hens could approach the nestbox only along one corridor, and return to the home pen by another. The four treatments consisted of leaving the corridor leading to the nestbox empty, or placing a hen that was dominant, subordinate or unfamiliar to the test-bird in it. Hens took longer to enter the corridor leading to the nestbox when there was a dominant or unfamiliar stimulus-bird than with a subordinate or an empty corridor. They also made more attempts to find alternative routes to the nestbox during the searching phase of pre-laying behaviour when there was a dominant or unfamiliar stimulus-bird, than with a subordinate stimulus-bird or empty pen and made fewer entries into the corridor with an unfamiliar stimulus-bird, but not a dominant or subordinate stimulus-bird or an empty pen. We suggest that hens are weakly motivated to reach the nest site during the searching phase. However, the motivation to gain access to a nest site increases near the start of the sitting phase of pre-laying behaviour.

Activation of replication origins in phi29-related phages requires the recognition of initiation proteins to specific nucleoprotein complexes

Protein p6 of Bacillus subtilis phage phi29 activates the initiation of viral DNA replication by forming a multimeric nucleoprotein complex at the origins of replication, located at both ends of the linear genome. This activation requires a precise positioning of the protein p6 array with respect to the initiation site. To investigate this activation mechanism, we have purified the phi29 protein p6 counterparts from the related phages Nf and GA-1 and analyzed the formation of complexes with DNA. In the homologous protein p6-DNA complexes the phi29 and Nf protein arrays showed an identical positioning, different than that of the GA-1 protein array. In contrast, in the heterologous complexes the protein showed a different arrangement except in the case of the Nf protein-phi29 DNA complex. We have also purified the proteins involved in the initiation of replication (terminal protein and DNA polymerase) from phages Nf and GA-1 and measured the ability of the different p6 proteins to activate homologous and heterologous replication origins. The results obtained indicate that the activation requires not only the formation of a specific nucleoprotein complex but also its specific recognition by the proteins involved in the initiation of DNA replication.

Protein-nucleic acid interactions in bacteriophage phi 29 DNA replication

phi 29 DNA replication starts at both DNA ends by a protein priming mechanism. The formation of the terminal protein-dAMP initiation complex is directed by the second nucleotide from the 3' end of the template. The transition from protein-primed initiation to normal DNA elongation has been proposed to occur by a sliding-back mechanism that is necessary for maintaining the sequences at the phi 29 DNA ends. Structure-function studies have been carried out in the phi 29 DNA polymerase. By site-directed mutagenesis of amino acids conserved among distantly related DNA polymerases we have shown that the N-terminal domain of phi 29 DNA polymerase contains the 3'-5' exonuclease activity and the strand-displacement capacity, whereas the C-terminal domain contains the synthetic activities (protein-primed initiation and DNA polymerization). Viral protein p6 stimulates the initiation of phi 29 DNA replication. The structure of the protein p6-DNA complex has been determined, as well as the main signals at the phi 29 DNA ends recognized by protein p6. The DNA binding domain of protein p6 has been studied. The results indicate that an alpha-helical structure located in the N-terminal region of protein p6 is involved in DNA binding through the minor groove. The phi 29 protein p5 is the single-stranded DNA binding (SSB) protein involved in phi 29 DNA replication, by binding to the displaced single-stranded DNA (ssDNA) in the replication intermediates. In addition, protein p5 is able to unwind duplex DNA. The properties of the phi 29 SSB-ssDNA complex are described. Using the four viral proteins, terminal protein, DNA polymerase, protein p6 and the SSB protein, it was possible to amplify the 19,285-bp phi 29 DNA molecule by a factor of 4000 after 1 h of incubation at 30 degrees C. The infectivity of the in vitro amplified DNA was identical to that of phi 29 DNA obtained from virions.

A new protein domain for binding to DNA through the minor groove

Protein p6 of the Bacillus subtilis phage phi 29 binds with low sequence specificity to DNA through the minor groove, forming a multimeric nucleoprotein complex that activates the initiation of phi 29 DNA replication. Deletion analysis suggested that the N-terminal part of protein p6, predicted to form an amphipathic alpha-helix, is involved in DNA binding. We have constructed site-directed mutants at the polar side of the putative alpha-helix. DNA binding and activation of initiation of phi 29 DNA replication were impaired in most of the mutant proteins obtained. A 19 amino acid peptide comprising the N-terminus of protein p6 interacted with a DNA fragment containing high-affinity signals for protein p6 binding with approximately 50-fold higher affinity than the peptide corresponding to an inactive mutant. Both wild-type peptide and protein p6 recognized the same sequences in this DNA fragment. This result, together with distamycin competition experiments, suggested that the wild-type peptide also binds to DNA through the minor groove. In addition, CD spectra of the wild-type peptide showed an increase in the alpha-helical content when bound to DNA. All these results indicate that an alpha-helical structure located in the N-terminal region of protein p6 is involved in DNA binding through the minor groove.

DNA structure in the nucleoprotein complex that activates replication of phage phi 29

Initiation of phage phi 29 DNA replication is activated by the viral protein p6 which forms a nucleoprotein complex at the replication origins, located at the linear genome ends. The complex consists of a DNA right-handed superhelix wrapped around a multimeric protein core. We have determined the superhelical path of the DNA in the complex, measuring the change in linking number induced by the protein, the surface-related helical repeat and the compaction of the DNA. One superhelical turn has approximately 63 bp (2.6 p6 dimers). Furthermore, we have determined that the DNA binding domain of protein p6 is located at the N-terminal region, predicted to form an amphipathic alpha-helix. We have obtained, by site-directed mutagenesis, protein p6 mutants in the polar side of the putative helix in which their DNA binding and replication activation properties were impaired or undetectable, in agreement with in vivo results.

Assembly of phage phi 29 genome with viral protein p6 into a compact complex

The formation of a multimeric nucleoprotein complex by the phage phi 29 dsDNA binding protein p6 at the phi 29 DNA replication origins, leads to activation of viral DNA replication. In the present study, we have analysed protein p6-DNA complexes formed in vitro along the 19.3 kb phi 29 genome by electron microscopy and micrococcal nuclease digestion, and estimated binding parameters. Under conditions that greatly favour protein-DNA interaction, the saturated phi 29 DNA-protein p6 complex appears as a rigid, rod-like, homogeneous structure. Complex formation was analysed also by a psoralen crosslinking procedure that did not disrupt complexes. The whole phi 29 genome appears, under saturating conditions, as an irregularly spaced array of complexes approximately 200-300 bp long; however, the size of these complexes varies from approximately 2 kb to 130 bp. The minimal size of the complexes, confirmed by micrococcal nuclease digestion, probably reflects a structural requirement for stability. The values obtained for the affinity constant (K(eff) approximately 10(5) M-1) and the cooperativity parameter (omega approximately 100) indicate that the complex is highly dynamic. These results, together with the high abundance of protein p6 in infected cells, lead us to propose that protein p6-DNA complexes could have, at least at some stages, during infection, a structural role in the organization of the phi 29 genome into a nucleoid-type, compact nucleoprotein complex.

Phage phi 29 protein p6: a viral histone-like protein

Phage phi 29 protein p6 is one of the most abundant viral proteins in phi 29-infected B subtilis cells, constituting about 4% of the total cellular proteins (about 3 x 10(6) copies/cell) at late infection. Electron microscopic studies showed that, in vitro, protein p6 forms heterogeneously-sized complexes all along phi 29 DNA, suggesting that protein p6 may have a role in genome packaging and organization. The low stability of the protein p6-phi 29 DNA complexes observed in vitro could reflect the dynamic nature of these complexes, to allow replication, transcription, and encapsidation of the genome. The protein p6-DNA complex consists of a DNA right-handed superhelix wrapped around a multimeric protein core. The DNA in this complex is strongly distorted and compacted. Protein p6 recognition signals have been mapped near the ends of the linear phi 29 DNA and act as nucleation sites for complex formation. Protein p6 does not recognize a specific sequence, but sequences with specific bendable properties that would favor the formation of the complex. Protein p6 represses transcription from the phi 29 C2 early promoter, and activates initiation of phi 29 DNA replication that occurs from both DNA ends. The formation of nucleoprotein complexes at the origins of replication, as well as the specific positioning of protein p6 with respect to the DNA ends are required for the activation of replication. This suggests that the proteins involved in the initiation step of phi 29 DNA replication, either directly interact with protein p6, or recognize a conformational change at a specific location in the DNA. The mechanism of activation could be the local and transient unpairing of DNA at specific sites, facilitated by the strong distortion of DNA conformation in the nucleoprotein complex.

Long-acting contraceptive agents: testosterone esters of unsaturated acids

The synthesis of 13 new esters of testosterone is described, with the esterifying acids bearing acetylenic, olefinic, or polyunsaturated functions in the chain, for evaluation as long-acting androgens.

[Miliary tuberculosis in adults. Study of 67 patients]

67 patients with miliary TB diagnosed over a 15 year period (1973-1987) have been retrospectively studied. The clinical and analysis data were evaluated, highlighting different factors associated to higher mortality. 53 patients diagnoses were made premortem and 14 had the diagnosis made post-mortem. The age of the patients was of 48 +/- 21 (mean +/- DE) years, inferior to other series, this showing a higher prevalence and early age of infection in the area. 63% had miliary radiological features; the most frequent tests performed were liver biopsy with profitability of 80% and bronchoscopy which, together with transbronchial biopsy and bacterial analysis of the bronchoalveolar lavage, showed a positive diagnosis of 60%. The factors which were associated with bad prognosis were cavitated or chronic lesions (P less than 0.01), chronic diseases and immunosuppression factors associated, this not being statistically significant.