The minor components of the rat asialoglycoprotein receptor are apically located in neonatal enterocytes

Because specific uptake of the asialoglycoprotein haptocorrin has been reported in suckling distal intestine, evidence of the asialoglycoprotein receptor in rat ileum was sought. On Western blot, two different polyclonal antisera against purified rat holoreceptor recognized only proteins of the size of the minor receptor components (51 and 55 kilodaltons) in both suckling and adult rat intestine. Messenger RNA encoding the minor component (RHL-2/3) was detected in total RNA extracted from rat ileum. Calcium-specific binding of porcine or rat haptocorrin-[57Co]cobalamin complexes was detected in the brush border membranes of distal suckling rat and porcine small intestine. This binding was almost completely blocked by another asialoglycoprotein, asialofetuin. The pH optimum for binding was 6-9, with a Ka of 0.25 nmol/L and a capacity of 4.6 fmol/mg protein. These properties, with the exception of the low capacity, are all consistent with those of the intact receptor on hepatocytes. The intestinal receptor was localized not to the basolateral membrane, as in the liver, but to the apical brush border, as suggested by the binding data. Furthermore, immunoperoxidase stains of paraffin-embedded tissue detected strong binding to the brush border and apical phagolysosome of mid and distal suckling rat intestine. These data show that, contrary to expectations, the minor components of the asialoglycoprotein receptor are functional and expressed in the apical membrane of the suckling intestine. The abundance of the protein by Western blot suggests possible roles for it in the neonatal gut other than haptocorrin binding.     

An analysis of blood donation barriers experienced by North American and Caribbean university students in Grenada,West Indies

Objectives

To estimate the associations of nationality, university program, donation history and gender, with blood donation barriers experienced by non-donating students on the day of a campus blood drive. This project focused particularly on nationality and the effect of the different blood donation cultures in the students' countries of origin.

Gender differences in acute coronary syndromes: focus on the women with ACS without an obstructing culprit lesion

Introduction: The etiologies of acute coronary syndromes (ACS) in women expand beyond the traditional paradigm of obstructive epicardial atherosclerotic disease and plaque rupture. Fundamental differences in pathobiology and presentation can partially explain the gender disparity in ACS diagnosis and management, but there is also much we do not know about the spectrum of coronary artery disease in women.

Areas covered: This review seeks to explain some key differences between men and women in terms of risk factors, pathophysiology, and clinical presentations, as well as identify areas where more data are needed, focusing on women presenting with ACS but without a culprit lesion to explain their presentation. Literature search was undertaken with PubMed and Google Scholar.

Expert commentary: Women with acute coronary syndromes but without plaque rupture or obstructive epicardial atherosclerosis can be difficult to diagnose and manage. Improving care in this underdiagnosed and undertreated population will require early identification of at risk patients, development of better diagnostic strategies, and standardized implementation of guideline-based therapies.     

Pain After Spinal Cord Injury Is Associated With Abnormal Presynaptic Inhibition in the Posterior Nucleus of the Thalamus

Pain after spinal cord injury (SCI-Pain) is one of the most debilitating sequelae of spinal cord injury, characterized as relentless, excruciating pain that is largely refractory to treatments. Although it is generally agreed that SCI-Pain results from maladaptive plasticity in the pain processing pathway that includes the spinothalamic tract and somatosensory thalamus, the specific mechanisms underlying the development and maintenance of such pain are yet unclear. However, accumulating evidence suggests that SCI-Pain may be causally related to abnormal thalamic disinhibition, leading to hyperactivity in the posterior thalamic nucleus (PO), a higher-order nucleus involved in somatosensory and pain processing. We previously described several presynaptic mechanisms by which activity in PO is regulated, including the regulation of GABAergic as well as glutamatergic release by presynaptic metabotropic gamma-aminobutyric acid (GABA_B) receptors. Using acute slices from a mouse model of SCI-Pain, we tested whether such mechanisms are affected by SCI-Pain. We reveal 2 abnormal changes in presynaptic signaling in the SCI-Pain condition. The substantial tonic activation of presynaptic GABA_B receptors on GABAergic projections to PO—characteristic of normal animals—was absent in mice with SCI-Pain. Also absent in mice with SCI-Pain was the normal presynaptic regulation of glutamatergic projections to the PO by GABA_B receptors. The loss of these regulatory presynaptic mechanisms in SCI-Pain may be an element of maladaptive plasticity leading to PO hyperexcitability and behavioral pain, and may suggest targets for development of novel treatments.

The effect of physician gender on length of patient consultations: observational findings from the UK hospital setting and synthesis with existing studies

Objectives

To investigate the effect of physician gender on consultation length in UK hospital outpatient clinics and compare this, through meta-analysis, with previous studies outside the UK.

Design

Observational data on clinic times were analysed and findings were combined in a meta-analysis with existing studies investigating the effect of physician gender on consultation length.

Setting

UK hospital practice.

Participants

A total of 174 observations of outpatient consultations with 10 hospital specialists (consultants) from different specialties in two UK hospital trusts.

Main outcome measures

Clinic times were recorded and analysis of consultation length was undertaken with physician gender as a covariate. Data were then synthesised through meta-analysis with 10 existing studies in this field.

Results

No statistically significant difference was found in the length of consultations for male and female doctors in these UK hospital settings. When pooled with existing studies, consultations with women doctors were found to be approximately two minutes longer than with men (p = 0.01).

Conclusions

Findings from this analysis of clinic consultations in the UK National Health Service do not support previous studies, which were undertaken predominantly in North America and primary care settings. Overall, meta-analysis suggests doctors’ gender may influence consultation length. Gender differences in communication should be considered in training clinicians and in overall clinical practice.     

Myopathy in older people receiving statin therapy: a systematic review and meta-analysis

Objective

The aim of the present study was to determine the risk of myopathy in older people receiving statin therapy.

Methods

Eligible studies were identified searching Ovid Medline, EMBASE, Scopus, CINAHL, Cochrane and PSYCHINFO databases (1987 to July 2014). The selection criteria comprised randomized controlled studies that compared the effects of statin monotherapy and placebo on muscle adverse events in the older adult (65+ years). Data were extracted and assessed for validity by the authors. Odds ratios and 95% confidence intervals (CIs) were used to calculate binary outcomes. Evidence from included studies were pooled in a meta-analysis using Revman 5.3.

Results

The trials assessed in the systematic review showed little or no evidence of a difference in risks between treatment and placebo groups, with myalgia [odds ratio (OR) 1.03, 95% CI 0.90, 1.17; I² = 0%; P = 0.66] and combined muscle adverse events (OR 1.03, 95% CI 0.91, 1.18; I² = 0%; P = 0.61) (myopathy). No evidence was found for an increased risk of rhabdomyolysis (OR 2.93, 95% CI 0.30, 28.18; I² = 0%; P = 0.35) in the seven trials that reported this. No trials reported mortality due to a muscle-related event. Discontinuations due to an adverse effect were reduced in the treatment group compared with placebo (OR 0.74, 95% CI 0.50, 1.09; I² = 0%; P = 0.13).

Conclusion

The results obtained from the present review suggest that statins are relatively safe, even in older people. There was no evidence to suggest an increased risk of myopathy in older adults receiving statin therapy. There is slightly increased seen with rhabdomyolysis when compared with the general population, although the event is relatively rare. Statins should be prescribed to elderly people who need it, and not withheld, as its myopathy safety profile is tolerable.