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PubMed2006

Genotyping of beta-lactoglobulin gene by PCR-RFLP in Sahiwal and Tharparkar cattle breeds.

BACKGROUND: Improvement of efficiency and economic returns is an important goal in dairy farming, as in any agricultural enterprise. The primary goal of dairy industry has been to identify an efficient and economical way of increasing milk production and its constituents without increasing the size of the dairy herd. Selection of animals with desirable genotypes and mating them to produce the next generation has been the basis of livestock improvement and this would continue to remain the same in the coming years. The use of polymorphic genes as detectable molecular markers is a promising alternative to the current methods of trait selection once these genes are proven to be associated with traits of interest in animals. The point mutations in exon IV of bovine beta-Lactoglobulin gene determine two allelic variants A and B. These variants were distinguished by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) analysis in two indigenous Bos indicus breeds viz. Sahiwal and Tharparkar cattle. DNA samples (228 in Sahiwal and 86 in Tharparkar) were analyzed for allelic variants of beta-Lactoglobulin gene. Polymorphism was detected by digestion of PCR amplified products with Hae III enzyme, and separation on 12% non-denaturing gels and resolved by silver staining. RESULTS: The allele B of beta-Lactoglobulin occurred at a higher frequency than the allele A in both Sahiwal and Tharparkar breeds. The genotypic frequencies of AA, AB, and BB in Sahiwal and Tharparkar breeds were 0.031, 0.276, 0.693 and 0.023, 0.733, 0.244 respectively. Frequencies of A and B alleles were 0.17 and 0.83, and 0.39 and 0.61 in Sahiwal and Tharparkar breeds respectively. The Chi-square test results (at one degree of freedom at one per cent level) revealed that the Tharparkar population was not in Hardy-Weinberg equilibrium as there was a continuous migration of animals in the herd studied, where as, the results are not significant for the Sahiwal population. CONCLUSION: Genotype frequencies of AA were the lowest compared to that of BB genotype in Sahiwal cattle while AB genotypes were more frequent in Tharparkar cattle. The frequency of A allele was found to be lower than that of B allele in both the breeds studied. These results further confirm that Bos indicus cattle are predominantly of beta-Lactoglobulin B type than Bos taurus breeds.

Alleles↗
PubMed2004

Magnetoreception and its trigeminal mediation in the homing pigeon.

Two conflicting hypotheses compete to explain how a homing pigeon can return to its loft over great distances. One proposes the use of atmospheric odours and the other the Earth's magnetic field in the 'map' step of the 'map and compass' hypothesis of pigeon homing. Although magnetic effects on pigeon orientation provide indirect evidence for a magnetic 'map', numerous conditioning experiments have failed to demonstrate reproducible responses to magnetic fields by pigeons. This has led to suggestions that homing pigeons and other birds have no useful sensitivity to the Earth's magnetic field. Here we demonstrate that homing pigeons (Columba livia) can discriminate between the presence and absence of a magnetic anomaly in a conditioned choice experiment. This discrimination is impaired by attachment of a magnet to the cere, local anaesthesia of the upper beak area, and bilateral section of the ophthalmic branch of the trigeminal nerve, but not of the olfactory nerve. These results suggest that magnetoreception (probably magnetite-based) occurs in the upper beak area of the pigeon. Traditional methods of rendering pigeons anosmic might therefore cause simultaneous impairment of magnetoreception so that future orientation experiments will require independent evaluation of the pigeon's magnetic and olfactory systems.

Animal Migration↗
PubMed1987

Mechanisms of liver cell damage in acute hepatitis B.

Markers of hepatitis B viral infection and the evolution of immune response to these were compared with serum alanine aminotransferase (ALT) levels in adult male and non-pregnant and pregnant female patients with acute hepatitis B from the time of onset of disease to the seventh week. In the adult male and non-pregnant female patients, the peak ALT levels of about 360 IU/litre, seen at the time of onset, gradually declined during the course of the disease. Significantly, even in the seventh week, the median ALT level was abnormal (80 IU/litre). In contrast, the disease was mild in pregnant patients and the ALT levels declined rapidly, returning to normal by the third week. Markers associated with HBV replication, i.e., serum HBV-DNA and HBeAg, declined early in the course of the disease in both groups. The anti-HBc-IgM and anti-HBe responses were well evolved early in the course of the disease in both groups. HBsAg was present in the serum in large amounts (1-1.5 X 10(4) AU/100 microliter) early in the course of the disease and remained so up to the seventh week. Even the pregnant patients who had recovered clinically by the fourth week continued to have HBsAg in their sera in large amounts in spite of normal ALT levels. LMI and LTT responses to HBsAg, which were practically absent in the first week, gradually increased to a peak during the fourth week and remained elevated up to the seventh week in adult male and non-pregnant female patients. In contrast, LMI response to HBsAg was absent in pregnant patients with acute hepatitis B even up to the fourth week Thus, continued liver cell necrosis after the fourth week, as indicated by raised ALT levels, may be associated with T cell responses to HBsAg.

Acute Disease↗
PubMed2002

Overlapping roles of P-selectin and alpha 4 integrin to recruit leukocytes to the central nervous system in experimental autoimmune encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is mediated by inflammatory cells recruited from the circulation to the CNS. We used intravital microscopy to investigate the mechanisms of this recruitment. No leukocyte rolling and very little adhesion was observed in healthy control mice. In contrast, both rolling and adhesion was observed in brain postcapillary venules before onset of physical symptoms of EAE. Rolling and adhesion remained elevated for 2 wk and returned to near normal levels by 5 wk postsymptom onset. Consistent with a role for P-selectin in recruitment to the CNS, P-selectin protein was detected in the brains and spinal cords of EAE mice. Expression was highest before symptom onset and decreased over the next 2 wk. The importance of alpha(4) integrin increased with time as anti-alpha(4) integrin blocked approximately 20, 50, and 60% of leukocyte rolling 2 days before disease onset, 5 days and 2 wk postonset of symptoms, respectively, and 85% of rolling 5 wk postsymptoms. Addition of anti-P-selectin to alpha(4) integrin Ab-treated mice blocked all remaining rolling at each time point. Interestingly, however, alpha(4) integrin-mediated rolling appeared to be entirely dependent on P-selectin as anti-P-selectin alone was able to completely block all leukocyte rolling. In the absence of rolling (with P-selectin Ab), a 70% reduction in adhesion was noted. A very similar reduction was seen when mice were treated with alpha(4) integrin-blocking Ab. In conclusion, we describe increased leukocyte trafficking in the brains of EAE mice with important overlapping roles for both P-selectin and alpha(4) integrin in mediating leukocyte-endothelial cell interactions.

Animals↗
PubMed1989

Microscopic observation of leukocyte kinesis in the vascular bed during hemodialysis using the rabbit ear chamber technique.

Leukocyte kinesis in the capillary vascular bed during hemodialysis (HD) was investigated to elucidate the mechanism of transient leukopenia. Leukocyte movement was observed microscopically during HD using the rabbit ear chamber (REC) technique, which permits visualization of the movement of blood corpuscles in capillaries. Blood was drawn from the femoral artery and returned into the auricular and/or carotid artery so that the blood passing through the hollow fiber artificial kidney (HFAK) flowed into capillaries in the REC. Leukocyte counts of blood samples taken from the afferent and efferent limbs of the HD circuit, the right jugular vein and the right atrium were determined consecutively during HD. The difference in the leukocyte count was observed between the afferent and efferent limbs for the first 15 minutes and thereafter between the efferent limb and the jugular vein. The "transpulmonary" difference in the leukocyte count was not noticed throughout HD. Between 15 and 90 minutes after the start of HD, scarcely any circulating leukocytes were found in capillaries in the REC and some leukocytes were attached to the endothelial surface. Thereafter circulating leukocytes were seen again and detachment of leukocytes from the endothelial surface was observed. No leukocyte aggregation or embolization of aggregating leukocytes was noticed. This evidence suggests that leukopenia may be attributed to the transient shift of leukocytes to the marginal pool of the vessel lumen and this process may not be specific for the pulmonary vasculature, but may occur in the first capillary bed into which the blood passing through the HFAK flows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Climate and spatio-temporal variation in the population dynamics of a long distance migrant, the white stork.

1. A central question in ecology is to separate the relative contribution of density dependence and stochastic influences to annual fluctuations in population size. Here we estimate the deterministic and stochastic components of the dynamics of different European populations of white stork Ciconia ciconia. We then examined whether annual changes in population size was related to the climate during the breeding period (the 'tap hypothesis' sensu Saether, Sutherland & Engen (2004, Advances in Ecological Research, 35, 185 209) or during the nonbreeding period, especially in the winter areas in Africa (the 'tube hypothesis'). 2. A general characteristic of the population dynamics of this long-distance migrant is small environmental stochasticity and strong density regulation around the carrying capacity with short return times to equilibrium. 3. Annual changes in the size of the eastern European populations were correlated by rainfall in the wintering areas in Africa as well as local weather in the breeding areas just before arrival and in the later part of the breeding season and regional climate variation (North Atlantic Oscillation). This indicates that weather influences the population fluctuations of white storks through losses of sexually mature individuals as well as through an effect on the number of individuals that manages to establish themselves in the breeding population. Thus, both the tap and tube hypothesis explains climate influences on white stork population dynamics. 4. The spatial scale of environmental noise after accounting for the local dynamics was 67 km, suggesting that the strong density dependence reduces the synchronizing effects of climate variation on the population dynamics of white stork. 5. Several climate variables reduced the synchrony of the residual variation in population size after accounting for density dependence and demographic stochasticity, indicating that these climate variables had a synchronizing effect on the population fluctuations. In contrast, other climatic variables acted as desynchronizing agents. 6. Our results illustrate that evaluating the effects of common environmental variables on the spatio-temporal variation in population dynamics require estimates and modelling of their influence on the local dynamics.

Animal Migration↗
PubMed2001

Effect of implant lengthening and mode of fixation on knee laxity after ACL reconstruction with an artificial ligament: a cadaveric study.

An "apparent" lengthening of the ligament implant, which causes an increase in knee laxity after the reconstruction of the anterior cruciate ligament (ACL) may be due to either slippage of the implant from under the fixation devices, or tunnel migration (due to bone resorption). These two mechanisms are related to the initial ligament placement, implant tensioning, and fixation modes. This cadaveric study simulates, in a controlled experimental situation, the postoperative lengthening of artificial ACL implants, and seeks to quantify the consequent increase in joint laxity. Eight cadaveric right knees, in which the Leeds-Keio artificial ligament was implanted, were tested in a specially constructed apparatus, which allowed the knee joint six degrees of freedom. In each of the tested joints the laxity was measured under several test conditions for two final fixation modes of the implant. The difference between the fixation modes was the application (as in mode B) or not (as in mode A), of a posteriorly directed force of 50 N on the tibia, at the moment of final fixation of the ligament. In both cases a tensile load of 50 N was maintained along the implant. All measurements were taken at flexion angles of 20 degrees and 90 degrees and with controlled implant lengthening of up to 3 mm in 0.5-mm increments. After implantation, adopting fixation mode B resulted in the knee exhibiting an anterior laxity considerably less than the original physiological laxity, compared with that measured after using fixation mode A. Thus at 20 degrees of knee flexion, under an anterior load of 100 N applied on the tibia, adopting fixation mode B, the joint laxity was 2.8 mm smaller than the natural laxity, whereas, for fixation mode A, it was 1.4 mm larger. At 90 degrees of knee flexion, the situation was similar, but with smaller differences. However, the situation was overturned as the implant length was increased. Thus, at 20 degrees of knee flexion, when the implant was lengthened in a range of 1--2 mm, the laxity observed with fixation mode B was similar to that recorded when the ACL was intact, whereas the laxity observed with fixation mode A was about 3--4 mm greater. Similar data were observed at 90 degrees of knee flexion. It appears that fixing the implant finally by applying a tensile load on it while simultaneously pushing the tibia posteriorly could be an effective measure against the possible return of joint laxity.

Adult↗
PubMed2000

Adverse effects of fetal cocaine exposure on neonatal auditory information processing.

BACKGROUND: Studies with animals have shown that in utero exposure to cocaine interferes with fetal brain development by disrupting the processes of neuronal proliferation, differentiation, and migration, often leading to subsequent neurobehavioral deficits. However, studies with humans have produced inconsistent findings. Although neurobehavioral abnormalities have been observed among cocaine-exposed infants in several studies and in some cases dose-response effects have been found, the specific neurobehaviors affected vary from one study to the next. Researchers studying the effects of fetal cocaine-exposure are faced with many difficult challenges. For example, women who use cocaine typically use other substances in addition to cocaine, many of the methods available for identifying cocaine-exposed neonates are not reliable, and the available methods for assessing cocaine-exposed newborns may not be sufficiently sensitive to detect the subtle effects of cocaine on the developing central nervous system. Despite these difficulties, there is a growing body of research that suggests that fetal cocaine exposure is associated with subsequent language deficits among children exposed in utero. However, it is virtually impossible to disentangle the effects of the impoverished environments in which these children are often raised from the effect, if any, of fetal cocaine exposure. To determine the effects of fetal cocaine exposure independent of postnatal environmental effects, cocaine-exposed neonates would ideally be tested within the first few weeks of birth, and to identify early risks for subsequent language delay, well-researched auditory information processing measures could be used. OBJECTIVE: The purpose of the present study was to assess the effects of fetal cocaine exposure on neonatal auditory information processing ability. To overcome limitations of some previous studies on the neuroteratogenic effects of cocaine, such as unreliable subject identification techniques, inadequate control over confounding variables, and questionable measures of central nervous system integrity, a valid measure of auditory information processing was used in a rigorous, case-control design. METHOD: Newborn information processing was assessed using habituation and recovery of head-turning toward an auditory stimulus across the 3 phases of the procedure: familiarization, novelty, and dishabituation. During the familiarization phase, the infant orients and habituates to a repeated word; during the novelty phase, the infant recovers head-turning to a novel word and subsequently habituates to this word; and during the dishabituation phase the infant displays renewed head-turning to the return of the original stimulus. Testing takes approximately 20 minutes. This procedure has been shown previously to discriminate among infants at high-, moderate-, and low-risk for subsequent developmental delay. Twenty-five cocaine-exposed and 25 nonexposed control neonates, identified by meconium analysis, urine analysis, and/or maternal self-report, were tested on the auditory information processing procedure. The majority of infants were tested within the first few days of birth. Cocaine-exposed and control neonates were matched on birth weight, gestational age, Apgar scores, age at testing, and socioeconomic status as reflected by household income. Mothers were matched on age, weight gain, cigarette smoking, and alcohol consumption. RESULTS: Fetal cocaine exposure was associated with impaired auditory information processing. Both cocaine-exposed and nonexposed control neonates oriented to the familiarization stimulus, but cocaine-exposed neonates displayed impaired habituation. Moreover, cocaine-exposed neonates did not recover or habituate to the novel stimulus or dishabituate to the return of the familiarization stimulus. (ABSTRACT TRUNCATED)

Auditory Perception↗
PubMed1988

Order on programmes of assistance favouring emigrants, 15 January 1988.

This Order sets forth programs of assistance containing the following categories of aid: 1) aid for elderly emigrants who are Spanish or in the process of recovering Spanish citizenship and are ill and incapable of working; 2) aid to cover the extraordinary costs related to emigration or the return of Spanish emigrant workers and their families who are in a state of need; 3) aid to facilitate the integration into the workplace of returned Spanish emigrants who are unemployed; 4) aid for emigrant centers, associations, and federations helping Spanish emigrants; 5) aid to organizations to improve the assistance and hospital and cultural activities that they provide to Spanish emigrants; 6) aid to organizations that promote professional and occupational orientation and training to facilitate the professional promotion and insertion in the workplace of Spanish emigrant workers; 7) aid to Spanish emigrants and their families resident abroad who have special abilities and wish to pursue higher education and lack the means to do so in Spain; 8) aid to young Spanish emigrants resident abroad to promote their participation in cultural, sociocultural, artistic, and youth activities; 9) aid to promote the social integration of foreign workers in Spain; and 10) aid to programs involving the exchange of young workers within the European Economic Community. Further provisions of the Order deal with beneficiaries of aid, documentation required, and applications, among other things. This Order repeals provisions of an Order of 30 January 1987 (Boletin Oficial del Estado, No. 42, 18 February 1987, pp. 4952-4964) on the same topic in so far as those provisions are in conflict with the provisions of this Order.

Age Factors↗
PubMed1998

Occupational risk of HIV infection among western health care professionals posted in AIDS endemic areas.

In this study on occupational risks of HIV infection among 99 Dutch medics working in AIDS endemic areas, 61% reported percutaneous exposures during an average stay of 21 months. The mean number of injuries was lower among physicians (2.0 versus 3.9 per year) and higher among nurses (1.9 versus 1.2) than in previous research conducted in 1987-1990 among Dutch medics returning from Africa. But the reduction of exposures among physicians might be explained by the fact that the number of procedures they carried out was less in the later study. Also among nurses a shift of tasks was seen. On the basis of an estimated HIV prevalence in the patient population of 19%, a chance of transmission per accident of 0.3%, and 1.9 percutaneous exposures per year, the mean occupational risk of HIV infection per year can be estimated at 0.11% per person. Besides length of stay and number of activities, characteristics of the work setting were associated with the frequency of different kinds of injuries. From the analysis of 109 extensive descriptions of recent accidents, it appeared that the majority of the injuries occurred during routine activities and were self-inflicted. Injuries with hollow needles usually occurred after the actual medical act (e.g. during recapping). Carelessness (e.g. due to fatigue) or being in a hurry (e.g. because of an emergency) were also often the cause of percutaneous injuries, as were the poor quality of the equipment, lack of professional skills, or a combination of these factors. Prevention activities are still important to reduce the frequency of occupational exposures. But they will not eliminate them totally; from the descriptions of recent exposures it was clear that some of the injuries occurred in spite of precautions.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Bimodal run distribution in a northern population of sockeye salmon (Oncorhynchus nerka): life history and genetic analysis on a temporal scale.

Life history variation and genetic differentiation were analysed in sockeye salmon in Klukshu River, Yukon Canada over 7 years (1994-2000). Sockeye salmon return to the Klukshu River in two distinct runs, with a small 'early run' in June-August, and a larger 'late run' in August-September. A maximum likelihood test for clusters indicated that the return frequency distribution was bimodal in all the years analysed. Life history differences (fork length, sex ratio, age at maturity, fresh- and saltwater residency times) were found between the early and late runs; however, inconsistent patterns suggest that environmental effects outweigh, or strongly interact with, genetic effects for the life history characters evaluated. Analysis of variation at eight microsatellite loci showed that the early and late runs are genetically differentiated in all years examined (exact test). FST estimates between runs within years were significantly greater than zero (range: 0.018-0.041) for all years except one (0.004). The genetic variance explained by early vs. late runs (2.27%) was twice the variance among years (1.16%) based on analysis of molecular variance. Our neighbour-joining tree showed early and late runs generally clustering separately, indicating higher gene flow among the early or late run fish across years relative to between-run gene flow. Two years did not fit the general clustering pattern; although the early and late runs in 1995 and 2000 were genetically differentiated, they clustered separately from the rest of the groups. We cannot offer a definitive explanation for these anomalies; however, an analysis of possible cryptic population structure in early and late runs indicated that at least a few fish strayed between the runs in each year, and the highest rate of mixing was in 1995 and 2000. Our data indicate that the runs are at least partially reproductively isolated as a result of temporal and/or spatial isolating mechanisms. Such reproductive isolation has important implications for conservation and management of the Klukshu sockeye salmon, and make them an evolutionarily interesting group because of parallels with incipient speciation.

Alleles↗
PubMedDate not supplied

Extraprostatic seed placement and its effect on seed loss.

PURPOSE: The purpose of this study was to examine the relationship between extraprostatic seed placement and seed loss in a cohort of patients who had underwent both computed tomographic (CT) and magnetic resonance (MR) scans at day 0 and day 30 following brachytherapy. MATERIALS AND METHODS: Twenty-two patients with 1997 AJC clinical stage T1-T2 prostatic carcinoma were implanted with nonstranded I 125. Patients were selected solely by having a prostate volume between 15 and 60 cc and a willingness to return for 30-day follow-up CT and MR scans. The total number of I-125 sources implanted on day 0 ranged from 50 to 104 (median: 70). Preplan treatment planning methods have been previously described in detail: a modified peripheral loading pattern and treatment margins of 5-10 mm were used. Noncontrast postimplantation CT and MR scans were obtained 1-4 hours after implantation on day 0. The total seed count on days 0 and 30 was verified by plain radiograph. Pelvic MR (T1) images were registered with the CT images in the Varian planning system, using bony landmarks. The number of extracapsular seeds in each quadrant of the circumference was then totaled for each patient. A second set of plain radiographs (for seed counting), as well as CT and MR scans, were obtained 30 days after implantation (day 30) and were similarly analyzed. RESULTS: The number of extraprostatic seeds at day 0 ranged from 13 to 35, making up 17%-48% (median: 34%) of the total number implanted. Of the 22 patients, 10 lost one or more seeds between the implantation day and the 1-month follow-up. The mean number of seeds lost was 1.1 (+/- 1.7). There was no apparent relationship between the percent of extraprostatic seeds and the number of seeds lost. There was no apparent relationship between seed loss and number of seeds less than 3 mm or greater than 3 mm from the prostatic capsule. CONCLUSIONS: We have shown here that with CT and MR seed localization, extraprostatic seed placement does not appear to substantially increase the likelihood of seed loss after the procedure.

Brachytherapy↗
PubMed2004

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

BACKGROUND: Retention is the phase of orthodontic treatment that attempts to keep teeth in the corrected positions after orthodontic (dental) braces. Without a phase of retention there is a tendency for the teeth to return to their initial position (relapse). To prevent relapse almost every patient who has orthodontic treatment will require some type of retention. OBJECTIVES: To evaluate the effectiveness of different retention strategies used to stabilise tooth position after orthodontic braces. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Several journals were handsearched. No language restrictions were applied. Authors of randomised controlled trials (RCTs) were identified and contacted to identify unpublished trials. Most recent search: December 2002. SELECTION CRITERIA: RCTs on children and adults, who have had retainers fitted or adjunctive procedures undertaken, following orthodontic treatment with braces to prevent relapse. The outcomes are: how well the teeth are stabilised, survival of retainers, adverse effects on oral health and quality of life. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two reviewers. As no two studies compared the same retention strategies (interventions) it was not possible to combine the results of any studies. MAIN RESULTS: Four trials satisfied the inclusion criteria. These trials all compared different interventions: circumferential supracrestal fiberotomy (CSF) combined with full-time removable retainer versus a full-time removable retainer alone; circumferential supracrestal fiberotomy (CSF) combined with a nights-only removable retainer versus a nights-only removable retainer alone; removable Hawley retainer versus a clear overlay retainer; and three types of fixed retainers versus a removable retainer. There was weak unreliable evidence, based on data from one trial, that there was a statistically significant increase in stability in both the mandibular (p < 0.001) and maxillary anterior segments (p < 0.001) when the CSF was used, compared with when it was not used. There was also weak, unreliable evidence that teeth settle quicker with a Hawley retainer than with a clear overlay retainer after 3 months. The quality of the trial reports was generally poor. REVIEWER'S CONCLUSIONS: There are insufficient research data on which to base our clinical practice on retention at present. There is an urgent need for high quality randomised controlled trials in this crucial area of orthodontic practice.

Humans↗
PubMed2006

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

BACKGROUND: Retention is the phase of orthodontic treatment that attempts to keep teeth in the corrected positions after treatment with orthodontic (dental) braces. Without a phase of retention there is a tendency for the teeth to return to their initial position (relapse). To prevent relapse almost every patient who has orthodontic treatment will require some type of retention. OBJECTIVES: To evaluate the effectiveness of different retention strategies used to stabilise tooth position after orthodontic braces. SEARCH STRATEGY: The Cochrane Oral Health Group's (OHG) Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching of orthodontic journals was undertaken in keeping with the Cochrane OHG search programme. No language restrictions were applied. Authors of randomised controlled trials (RCTs) were identified and contacted to identify unpublished trials. Most recent search: May 2005. SELECTION CRITERIA: RCTs on children and adults, who have had retainers fitted or adjunctive procedures undertaken, following orthodontic treatment with braces to prevent relapse. The outcomes were: how well the teeth were stabilised, survival of retainers, adverse effects on oral health and quality of life. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. As no two studies compared the same retention strategies (interventions) it was not possible to combine the results of any studies. MAIN RESULTS: Five trials satisfied the inclusion criteria. These trials all compared different interventions: circumferential supracrestal fiberotomy (CSF) combined with full-time removable retainer versus a full-time removable retainer alone; CSF combined with a nights-only removable retainer versus a nights-only removable retainer alone; removable Hawley retainer versus a clear overlay retainer; multistrand wire retainer versus a ribbon-reinforced resin bonded retainer; and three types of fixed retainers versus a removable retainer. There was weak unreliable evidence, based on data from one trial, that there was a statistically significant increase in stability in both the mandibular (lower) (P < 0.001) and maxillary (upper) anterior segments (P < 0.001) when the CSF was used, compared with when it was not used. There was also weak, unreliable evidence that teeth settle quicker with a Hawley retainer than with a clear overlay retainer after 3 months. The quality of the trial reports was generally poor. AUTHORS' CONCLUSIONS: There are insufficient research data on which to base our clinical practice on retention at present. There is an urgent need for high quality randomised controlled trials in this crucial area of orthodontic practice.

Humans↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗