Strategies for Neoglycan conjugation to human acid α-glucosidase

Engineering proteins for selective tissue targeting can improve therapeutic efficacy and reduce undesired side effects. The relatively high dose of recombinant human acid α-glucosidase (rhGAA) required for enzyme replacement therapy of Pompe disease may be attributed to less than optimal muscle uptake via the cation-independent mannose 6-phosphate receptor (CI-MPR). To improve muscle targeting, Zhu et al. (1) conjugated periodate oxidized rhGAA with bis mannose 6-phosphate bearing synthetic glycans and achieved 5-fold greater potency in a murine Pompe efficacy model. In the current study, we systematically evaluated multiple strategies for conjugation based on a structural homology model of GAA. Glycan derivatives containing succinimide, hydrazide, and aminooxy linkers targeting free cysteine, lysines, and N-linked glycosylation sites on rhGAA were prepared and evaluated in vitro and in vivo. A novel conjugation method using enzymatic oxidation was developed to eliminate side oxidation of methionine. Conjugates derived from periodate oxidized rhGAA still displayed the greatest potency in the murine Pompe model. The efficiency of conjugation and its effect on catalytic activity were consistent with predictions based on the structural model and supported its use in guiding selection of appropriate chemistries.

Critical thinking: knowledge and skills for evidence-based practice

PURPOSE

I respond to Kamhi's (2011) conclusion in his article "Balancing Certainty and Uncertainty in Clinical Practice" that rational or critical thinking is an essential complement to evidence-based practice (EBP).

METHOD

I expand on Kamhi's conclusion and briefly describe what clinicians might need to know to think critically within an EBP profession. Specifically, I suggest how critical thinking is relevant to EBP, broadly summarize the relevant skills, indicate the importance of thinking dispositions, and outline the various ways our thinking can go wrong.

CONCLUSION

I finish the commentary by suggesting that critical thinking skills should be considered a required outcome of our professional training programs.

Combined inhibition of DNA methylation and histone acetylation enhances gene re-expression and drug sensitivity in vivo

Histone deacetylation and DNA methylation have a central role in the control of gene expression in tumours, including transcriptional repression of tumour suppressor genes and genes involved in sensitivity to chemotherapy. Treatment of cisplatin-resistant cell lines with an inhibitor of DNA methyltransferases, 2-deoxy-5′azacytidine (decitabine), results in partial reversal of DNA methylation, re-expression of epigenetically silenced genes including hMLH1 and sensitisation to cisplatin both in vitro and in vivo. We have investigated whether the combination of decitabine and a clinically relevant inhibitor of histone deacetylase activity (belinostat, PXD101) can further increase the re-expression of genes epigenetically silenced by DNA methylation and enhance chemo-sensitisation in vivo at well-tolerated doses. The cisplatin-resistant human ovarian cell line A2780/cp70 has the hMLH1 gene methylated and is resistant to cisplatin both in vitro and when grown as a xenograft in mice. Treatment of A2780/cp70 with decitabine and belinostat results in a marked increase in expression of epigenetically silenced MLH1 and MAGE-A1 both in vitro and in vivo when compared with decitabine alone. The combination greatly enhanced the effects of decitabine alone on the cisplatin sensitivity of xenografts. As the dose of decitabine that can be given to patients and hence the maximum pharmacodynamic effect as a demethylating agent is limited by toxicity and eventual re-methylation of genes, we suggest that the combination of decitabine and belinostat could have a role in the efficacy of chemotherapy in tumours that have acquired drug resistance due to DNA methylation and gene silencing.

Large and massive tears of the rotator cuff

The aim of this study was to determine the functional outcome and rate of re-tears following mini-open repair of symptomatic large and massive tears of the rotator cuff using a two-row technique.

The 24 patients included in the study were assessed prospectively before and at a mean of 27 months (18 to 53) after surgery using the Constant and the Oxford Shoulder scores. Ultrasound examination was carried out at follow-up to determine the integrity of the repair. Patient satisfaction was assessed using a simple questionnaire.

The mean Constant score improved significantly from 36 before to 68 after operation (p < 0.0001) and the mean Oxford Shoulder score from 39 to 20 (p < 0.0001). Four of the 24 patients (17%) had a re-tear diagnosed by ultrasound. A total of 21 patients (87.5%) were satisfied with the outcome of their surgery. The repair remained intact in 20 patients (83%). However, the small number of re-tears (four patients) in the study did not allow sufficient analysis to show a difference in outcome in relation to the integrity of the repair.

Controlled clinical trial of two weight reducing diets in a NHS hospital dietetic outpatient clinic - a pilot study

BACKGROUND

Outpatient dietary weight reduction for obesity is unsatisfactory. The objective of this study was to compare the efficacy of an energy prescription diet with usual care (a healthy eating diet) in adult overweight patients referred to a NHS hospital dietetic outpatient clinic, in terms of weight change over 12 weeks.

METHODS

Controlled clinical trial (systematic allocation).

RESULTS

Of the 53 patients who attended their first appointment, 27 completed the trial. Mean weight loss (kg) after 12 weeks was 4.2 (sd 3.8) on the energy prescription diet (n = 16) and 6.0 (sd 2.8) on the healthy eating diet (n = 11).

CONCLUSIONS

Patients on a weight reducing diet based on energy prescription or healthy eating lost, on average, clinically significant amounts of body weight by 12 weeks. Mean weight loss was greater by about 50% in the healthy eating group and supports the development of a larger trial to estimate true effect.

The knee skyline radiograph: its usefulness in the diagnosis of patello-femoral osteoarthritis

The aim of this study was to determine the usefulness of the skyline radiograph in the diagnosis of patellofemoral osteoarthritis. Additionally, we wanted to assess the usefulness of patello-femoral crepitus as a clinical sign of this condition. Seventy-seven patients scheduled to undergo knee surgery had standard antero-posterior, lateral and skyline X-rays of their affected knee. The presence of clinical patello-femoral crepitus was also documented preoperatively. At the operation, their patellofemoral joints were graded into two groups according to the presence or absence of osteoarthritis. The lateral and skyline view X-rays as well as patello-femoral crepitus were compared individually against the operative findings. The skyline view had a sensitivity of 79% and a specificity of 80%. The lateral view had a sensitivity of 82% and specificity of 65%. Patello-femoral crepitus as a sign had a sensitivity of 89% and a specificity of 82%. There was no statistically significant difference between the two radiological views in terms of sensitivity and specificity in the diagnosis of patellofemoral osteoarthritis. Hence, we cannot recommend the skyline view as a routine radiological investigation in all cases of suspected patellofemoral osteoarthritis.

Independent associations between weight status and disability in adults: Results from the health survey for England

OBJECTIVES

While direct links between obesity and some illnesses are well-established, there is a relative paucity of research on associations between obesity and disabilities. The aim of this study was to test for significant associations between overweight and obesity and the presence of a wide range of disabling conditions in adults, controlling for sex, age, education, social class, income, cigarette smoking status and alcohol consumption.

STUDY DESIGN

Data were extracted from the Health Survey for England (2001); a cross-sectional survey of the community-dwelling population. In total, 8613 adult participants were included in the analysis.

METHODS

Multivariate logistic regression was employed to test whether the odds of having a range of disabling conditions are higher in the overweight and obese populations compared with those in the ideal weight range.

RESULTS

The risk of nearly all disabling conditions tested was elevated in the obese and morbidly obese groups. Of great importance for public health, the risks of musculoskeletal illness, arthritis and rheumatism, and personal care disability were significantly elevated, even in those in the overweight category (currently about half of the adult population living in the UK).

CONCLUSIONS

Obesity is independently associated with a range of disabling conditions in adults. The present study highlights the need for further research into the mechanisms by which these associations occur.

Science and pseudoscience in communication disorders: criteria and applications

PURPOSE

The purpose of this tutorial is to describe 10 criteria that may help clinicians distinguish between scientific and pseudoscientific treatment claims. The criteria are illustrated, first for considering whether to use a newly developed treatment and second for attempting to understand arguments about controversial treatments.

METHOD

Pseudoscience refers to claims that appear to be based on the scientific method but are not. Ten criteria for distinguishing between scientific and pseudoscientific treatment claims are described. These criteria are illustrated by using them to assess a current treatment for stuttering, the SpeechEasy device. The authors read the available literature about the device and developed a consensus set of decisions about the 10 criteria. To minimize any bias, a second set of independent judges evaluated a sample of the same literature. The criteria are also illustrated by using them to assess controversies surrounding 2 treatment approaches: Fast ForWord and facilitated communication.

CONCLUSIONS

Clinicians are increasingly being held responsible for the evidence base that supports their practice. The power of these 10 criteria lies in their ability to help clinicians focus their attention on the credibility of that base and to guide their decisions for recommending or using a treatment.

Glove perforation and contamination in primary total hip arthroplasty

We conducted a randomised, controlled trial to determine whether changing gloves at specified intervals can reduce the incidence of glove perforation and contamination in total hip arthroplasty. A total of 50 patients were included in the study. In the study group (25 patients), gloves were changed at 20-minute intervals or prior to cementation. In the control group (25 patients), gloves were changed prior to cementation. In addition, gloves were changed in both groups whenever there was a visible puncture. Only outer gloves were investigated.

Contamination was tested by impression of gloved fingers on blood agar and culture plates were subsequently incubated at 37°C for 48 hours. The number of colonies and types of organisms were recorded. Glove perforation was assessed using the water test. The incidence of perforation and contamination was significantly lower in the study group compared with the control group. Changing gloves at regular intervals is an effective way to decrease the incidence of glove perforation and bacterial contamination during total hip arthroplasty.

Predictors of outcome after percutaneous treatment for cardiogenic shock

OBJECTIVES

To determine predictors of outcome after percutaneous coronary intervention (PCI) in patients with cardiogenic shock complicating acute myocardial infarction.

METHODS

Retrospective analysis of a cohort of 113 patients undergoing emergency coronary angiography and attempted PCI for cardiogenic shock complicating acute myocardial infarction in a regional cardiothoracic unit.

RESULTS

In-hospital mortality was 51% (58 patients). Adverse outcome was associated with previous myocardial infarction, age over 70 years, cardiogenic shock complicating failure to respond to thrombolytic treatment (failed thrombolysis), and multivessel coronary artery disease. Multivariate logistic regression analysis showed that the first three factors were independent predictors of in-hospital death with odds ratios of 5.21 (95% confidence interval (CI) 1.85 to 14.69), 4.02 (95% CI 1.14 to 14.12), and 3.78 (95% CI 1.43 to 9.96), respectively.

CONCLUSION

About 50% of patients with cardiogenic shock undergoing a strategy of urgent coronary angiography and PCI survive to hospital discharge. Survivors do well in the subsequent six months. Emergency PCI for cardiogenic shock reduces mortality from an expected 80% to about 50%. Clinical features can help determine which patients are most likely to gain from urgent coronary angiography and attempted PCI. Alternative strategies are needed to improve the outcome of patients who fare badly.

Sanders classification of fractures of the os calcis

Our study was undertaken to assess the inter- and intra-observer variability of the classification system of Sanders for calcaneal fractures. Five consultant orthopaedic surgeons with different subspecialty interests classified CT scans of 28 calcaneal fractures using this classification system. After six months, they reclassified the scans.

Kappa statistics were used to analyse the two groups. The interobserver variability of the classification system was 0.32 (95% confidence interval (CI) 0.26 to 0.38). The subclasses were then combined and assessment of agreement between the general classes as a whole gave a kappa value of 0.33 (95% CI 0.25 to 0.41). The mean kappa value for intra-observer variability of the classification system was 0.42 (95% CI 0.22 to 0.62). When the subclasses were combined, it was 0.45 (95% CI 0.21 to 0.65).

Our results show that, despite its popularity, the classification system of Sanders has only fair agreement among users.

Impairment on a simulated gambling task in long-term abstinent alcoholics

BACKGROUND

Recent research indicates that currently active or recently detoxified substance abusers make more disadvantageous decisions on a simulated gambling task (SGT). This study expands on the current literature by using the SGT to examine decision making in long-term abstinent alcoholics (mean of 6.6 years' abstinence) who do not have antisocial personality disorder or a history of conduct disorder.

METHODS

A total of 102 subjects (58 controls and 44 abstinent alcoholics) were tested on the SGT, in which subjects choose cards from 4 different decks that vary in terms of the magnitude of the immediate win (large or small) and the magnitude of long-term loss (large or small). The association of SGT performance with alcohol use variables, with the number of externalizing symptoms, and with personality measures of social deviance was examined.

RESULTS

Compared with controls, long-term abstinent alcohol-dependent subjects had more externalizing symptoms, had personality profiles associated with a proneness to social deviance, and made more disadvantageous decisions on the SGT. The magnitude of disadvantageous decision making was associated with the duration of peak alcohol use but was associated with only one measure (low socialization) of socially deviant personality traits.

CONCLUSIONS

The results suggest that alcoholics can achieve long-term abstinence despite persistent deficits in decision making and abnormal personality profiles. The decision-making deficits either may be the result of long-term alcoholism or may reflect a factor predisposing to alcoholism that persists with abstinence. The possibility is raised that alcoholics who cannot achieve long-term abstinence are even more impaired on their decision making and have more abnormal personality profiles than the abstinent alcoholics studied here.

"Roadblocks" revisited: neural change, stuttering treatment, and recovery from stuttering

In light of emerging findings concerning untreated recovery and neural plasticity, this paper re-examines the viability of an NIH conference recommendation [Cooper, J. A. (1990). Research directions in stuttering: Consensus and conflict. In Cooper, J. A. (Ed.), Research needs in stuttering: Roadblocks and future directions (pp. 98-100). Rockville, MD: American Speech-Language-Hearing Association.] that adults who have recovered from stuttering might inform our understanding of the nature and treatment of persistent stuttering. It is suggested that those who have recovered could constitute a behavioral, cognitive, and neurophysiologic benchmark for evaluating stuttering treatment for adolescents and adults, while helping to identify the limits of recovery from a persistent disorder. This possibility seems especially promising because of findings from recent studies investigating untreated recovery during childhood and adulthood, the emerging evidence concerning neural plasticity and reorganization, and reports of neural system changes during stuttering treatment. Potential obstacles to applying findings from unassisted recovery to treatment do exist, but the benefits of attempts to fully understand stuttering certainly outweigh the difficulties.

EDUCATIONAL OBJECTIVES

After completing this activity, the learner will be able to: (1) describe two complexities involved in determining whether recovery from stuttering was assisted or unassisted; (2) discuss the implications for stuttering research of two neural plasticity research findings from areas other than stuttering; and (3) evaluate the possible implications for stuttering treatment of a coordinated research program that addresses behavioral, cognitive, and neurological characteristics of assisted and unassisted recovery from stuttering.

Unassisted recovery from stuttering: self-perceptions of current speech behavior, attitudes, and feelings

The purpose of this study was to investigate the nature of recovery from stuttering based on the experiences of adults who recovered without treatment. Using a semi-structured, open-ended interview format, 15 speakers verified as persons who recovered without treatment were asked to describe their status as everyday speakers. Seven speakers reported that they no longer stuttered and eight reported that they still stuttered on occasion. Interview material was coded and analyzed by the investigators and checked by independent judges. Results suggested that complete recovery was possible for speakers who reported that they no longer stuttered; whereas, those who still stuttered occasionally appeared to no longer be handicapped by stuttering, but required some vigilance to maintain their relatively fluent speech.

EDUCATIONAL OBJECTIVES

After completing this activity, the learner will be able to: (1) describe the relevance of self-report data for evaluating the nature of recovery from stuttering without treatment; (2) describe the differences in self-perception concerning the nature of recovery for those who no longer have any tendency to stutter compared to those who still have an occasional tendency to stutter; and (3) suggest the possible implications for understanding the nature of recovery from persistent stuttering based on investigations of late recovery without treatment.

Controlled clinical trial of two weight reducing diets in a NHS hospital dietetic outpatient clinic - a pilot study

BACKGROUND

Outpatient dietary weight reduction for obesity is unsatisfactory. The objective of this study was to compare the efficacy of an energy prescription diet with usual care (a healthy eating diet) in adult overweight patients referred to a NHS hospital dietetic outpatient clinic, in terms of weight change over 12 weeks.

METHODS

Controlled clinical trial (systematic allocation).

RESULTS

Of the 53 patients who attended their first appointment, 27 completed the trial. Mean weight loss (kg) after 12 weeks was 4.2 (sd 3.8) on the energy prescription diet (n = 16) and 6.0 (sd 2.8) on the healthy eating diet (n = 11).

CONCLUSIONS

Patients on a weight reducing diet based on energy prescription or healthy eating lost, on average, clinically significant amounts of body weight by 12 weeks. Mean weight loss was greater by about 50% in the healthy eating group and supports the development of a larger trial to estimate true effect [corrected].