Letters to the Editor

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66363/1/j.1752-7325.1998.tb02993.x.pd

Movement variability emerges in gait as adaptation to task constraints in dynamic environments

Background: Motor variability has been related to motor control playing a functional role in human adaptive behaviours. However, the direction of the relationship between variability and motor control can be unclear. The specific relations that exist between task constraints and movement (re)organization could explain some of this controversy. Research question: This study sought to understand whether manipulation of task constraints result in changes in the magnitude or structure of motor system variability observed in a basic walking task. We also investigated the relationship between performance in achieving task goals and the structure of motor variability. Methods: Twenty volunteers walked around a circular track with binary combinations of 3 task constraints, providing 8 conditions. The manipulated task constraints were: 1) track width; 2) surface stiffness; and 3), walking direction. Performance was analysed using standard deviation (SD) of sacral displacement and its mean velocity (MV). Fuzzy Entropy (FE) and Detrended Fluctuation Analysis (DFA) were used to assess the kinematic variability structure. Results: Individuals showed lower SD and MV walking on the narrower track. These changes were also followed by higher DFA values, indicating a more auto-correlated structure of variability. The foam surface was also associated with an increase in amplitude, velocity and irregularity (FE) of movement. Significance: Results of this study describe how specific task constraints, such as the width of the walking track and the surface stiffness, shape emergent movement coordination patterns as participants search for functional information from the environment to regulate performance behaviors. Changes in variability structure could reveal the search for adaptive strategies during walking. Smaller movement fluctuations and higher velocity in gait patterns are related to greater irregularity and lower autocorrelation in the kinematic variability structure, demonstrating that a specific relationship emerges between system variability and movement performance, which is driven by task constraints

Longitudinal Evaluation of Sealing Molars with and without Incipient Dental Caries in a Public Health Program

Objectives: This study undertook a retrospective evaluation of the effect of sealants on the caries experience of initially sound and incipient permanent first molar pit and fissure surfaces. Methods : Records of children with complete five-year records were obtained from a school-based dental sealant program in a fluoridated community. Sealants were placed on 677 tooth surfaces in 96 children; 120 tooth surfaces in 17 children who received baseline examinations were not sealed because of lack of caregiver consent. Tooth surfaces were initially diagnosed as being sound or having incipient lesions, and evaluated for caries status after five years. Results : For initially incipient surfaces the five-year decay rate was 10.8 percent (41 of 380 surfaces) for sealed surfaces and 51.8 percent (29 of 56 surfaces) for nonsealed surfaces with an odds ratio of 8.88 (95% Cl=4.56, 17.35). Initially sound surfaces had a decay rate of 8.1 percent (24 of 297 surfaces) for sealed surfaces and 12.5 percent (8 of 64 surfaces) for nonsealed surfaces with an odds ratio of 1.63 (95% Cl=0.63, 4.08). The two odds ratios were significantly different. Conclusions : Initially sound tooth surfaces were unlikely to become decayed in five years, and did not benefit greatly from the application of sealants. Within the limitations of this study, there were clear efficiencies in sealing incipient, but not sound, surfaces. The targeting of teeth with incipient caries for sealants is therefore recommended.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66270/1/j.1752-7325.1995.tb02358.x.pd

Entomopathogenic Fungi as Mortality Factors of Macadamia Felted Coccid, Eriococcus ironsidei (Hemiptera: Eriococcidae) in Hawaii

Entomopathogenic fungi are considered to play a vital role as a biologi- cal control agent of many insect populations. Different entomopathogenic fungi were observed infecting Eriococcus ironsidei Williams (Hemiptera: Eriococcidae) in a macadamia nut orchard in Honokaa, Hawaii. Here, we report the results of the isolation of the unidentified fungal pathogens observed infecting E. ironsidei on macadamia leaves and their identification using molecular techniques. We evaluated the susceptibility of E. ironsidei to the isolated fungi and to one com- mercial formulation of the entomopathogenic fungus, Beauveria bassiana. To assess whether any of the isolated pathogens have potential to serve as biocontrol agents, E. ironsidei was exposed to isolated fungi. Identified entomopathogens were Chlorocillium griseum and Pleurodesmospora coccorum. Results of this study confirmed that C. griseum, P. coccorum, and B. bassiana cause mortality in E. ironsidei up to 67%, 78%, and 100%, respectively. The present investigation indicates that E. ironsidei is highly susceptible to these fungi and they may have a role in regulating insect pest populations

An archaeal family-B DNA polymerase variant able to replicate past DNA damage: occurrence of replicative and translesion synthesis polymerases within the B family

A mutant of the high fidelity family-B DNA polymerase from the archaeon Thermococcus gorgonarius (Tgo-Pol), able to replicate past DNA lesions, is described. Gain of function requires replacement of the three amino acid loop region in the fingers domain of Tgo-Pol with a longer version, found naturally in eukaryotic Pol zeta (a family-B translesion synthesis polymerase). Inactivation of the 3'–5' proofreading exonuclease activity is also necessary. The resulting Tgo-Pol Z1 variant is proficient at initiating replication from base mismatches and can read through damaged bases, such as abasic sites and thymine photo-dimers. Tgo-Pol Z1 is also proficient at extending from primers that terminate opposite aberrant bases. The fidelity of Tgo-Pol Z1 is reduced, with amarked tendency tomake changes at G:C base pairs. Together, these results suggest that the loop region of the fingers domain may play a critical role in determining whether a family-B enzyme falls into the accurate genome-replicating category or is an errorprone translesion synthesis polymerase. Tgo-Pol Z1 may also be useful for amplification of damaged DNA

Human PrimPol is a highly error-prone polymerase regulated by single-stranded DNA binding proteins

PrimPol is a recently identified polymerase involved in eukaryotic DNA damage tolerance, employed in both re-priming and translesion synthesis mechanisms to bypass nuclear and mitochondrial DNA lesions. In this report, we investigate how the enzymatic activities of human PrimPol are regulated. We show that, unlike other TLS polymerases, PrimPol is not stimulated by PCNA and does not interact with it in vivo. We identify that PrimPol interacts with both of the major single-strand binding proteins, RPA and mtSSB in vivo. Using NMR spectroscopy, we characterize the domains responsible for the PrimPol-RPA interaction, revealing that PrimPol binds directly to the N-terminal domain of RPA70. In contrast to the established role of SSBs in stimulating replicative polymerases, we find that SSBs significantly limit the primase and polymerase activities of PrimPol. To identify the requirement for this regulation, we employed two forward mutation assays to characterize PrimPol's replication fidelity. We find that PrimPol is a mutagenic polymerase, with a unique error specificity that is highly biased towards insertion-deletion errors. Given the error-prone disposition of PrimPol, we propose a mechanism whereby SSBs greatly restrict the contribution of this enzyme to DNA replication at stalled forks, thus reducing the mutagenic potential of PrimPol during genome replication

Adult case of partial trisomy 9q

Background: \ud Complete and partial trisomy 9 is the fourth most common chromosomal disorder. It is also associated with various congenital characteristics affecting the cranio-facial, skeletal, central nervous, gastrointestinal, cardiac and renal systems. Very few cases have been reported in adults. Partial trisomy 9q is also associated with short stature, poor growth and growth hormone deficiency. This is the first reported case of an extensive endocrinology investigation of short stature in trisomy 9q and the outcome of growth hormone treatment.\ud \ud Case Presentation: \ud The case involves a 23-year-old female of pure partial trisomy 9q. The case involves a 23-year old female with pure partial trisomy 9q involving a duplication of 9q22.1 to q32, de novo, confirmed by genetic studies using fluorescene in situ hybridization (FISH) method. The diagnosis was at 6 years of age. She did not demonstrate all the congenital morphologies identified with trisomy 9q disorders especially in relation to multi-organ morphologies. There is also a degree of associated intellectual impairment. At prepuberty, she was referred for poor growth and was diagnosed with partial growth hormone deficiency. She responded very well to treatment with growth hormone and is currently living an independent life with some support.\ud \ud Conclusions: \ud Trisomy 9q is associated with short stature and failure to thrive. Growth hormone deficiency should be identified in cases of trisomy 9q and treatment offered. This is the first reported case of response to growth hormone replacement in partial trisomy 9

Home-based therapy programmes for upper limb functional recovery following stroke

Background: With an increased focus on home-based stroke services and the undertaking of programmes, targeted at upper limb recovery within clinical practice, a systematic review of home-based therapy programmes for individuals with upper limb impairment following stroke was required. Objectives: To determine the effects of home-based therapy programmes for upper limb recovery in patients with upper limb impairment following stroke. Search methods: We searched the Cochrane Stroke Group's Specialised Trials Register (May 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), MEDLINE (1950 to May 2011), EMBASE (1980 to May 2011), AMED (1985 to May 2011) and six additional databases. We also searched reference lists and trials registers. Selection criteria: Randomised controlled trials (RCTs) in adults after stroke, where the intervention was a home-based therapy programme targeted at the upper limb, compared with placebo, or no intervention or usual care. Primary outcomes were performance in activities of daily living (ADL) and functional movement of the upper limb. Secondary outcomes were performance in extended ADL and motor impairment of the arm. Data collection and analysis: Two review authors independently screened abstracts, extracted data and appraised trials. We undertook assessment of risk of bias in terms of method of randomisation and allocation concealment (selection bias), blinding of outcome assessment (detection bias), whether all the randomised patients were accounted for in the analysis (attrition bias) and the presence of selective outcome reporting. Main results: We included four studies with 166 participants. No studies compared the effects of home-based upper limb therapy programmes with placebo or no intervention. Three studies compared the effects of home-based upper limb therapy programmes with usual care. Primary outcomes: we found no statistically significant result for performance of ADL (mean difference (MD) 2.85; 95% confidence interval (CI) -1.43 to 7.14) or functional movement of the upper limb (MD 2.25; 95% CI -0.24 to 4.73)). Secondary outcomes: no statistically significant results for extended ADL (MD 0.83; 95% CI -0.51 to 2.17)) or upper limb motor impairment (MD 1.46; 95% CI -0.58 to 3.51). One study compared the effects of a home-based upper limb programme with the same upper limb programme based in hospital, measuring upper limb motor impairment only; we found no statistically significant difference between groups (MD 0.60; 95% CI -8.94 to 10.14). Authors' conclusions: There is insufficient good quality evidence to make recommendations about the relative effect of home-based therapy programmes compared with placebo, no intervention or usual care