Resistance to RevM10 inhibition reflects a conformational switch in the HIV-1 Rev response element

Nuclear export of certain HIV-1 mRNAs requires an interaction between the viral Rev protein and the Rev response element (RRE), a structured element located in the Env region of its RNA genome. This interaction is an attractive target for both drug design and gene therapy, exemplified by RevM10, a transdominant negative protein that, when introduced into host cells, disrupts viral mRNA export. However, two silent G->A mutations in the RRE (RRE61) confer RevM10 resistance, which prompted us to examine RRE structure using a novel chemical probing strategy. Variations in region III/IV/V of mutant RNAs suggest a stepwise rearrangement to RevM10 resistance. Mass spectrometry was used to directly assess Rev “loading” onto RRE and its variants, indicating that this is unaffected by RNA structural changes. Similarity in chemical footprints with mutant protein implicates additional host factors in RevM10 resistance.     

Hypersensitivity and hyperalgesia in somatoform pain disorders

Objective

In psychiatry, pain disorders not explained by structural lesions have been classified for decades as somatoform pain disorders, the underlying concept being somatization. In a parallel move, somatic medicine has defined an expanding group of similar pain disorders, known as functional pain syndromes. Functional pain syndromes are characterized by enhanced pain sensitivity. The aim of our study was to investigate the proportion of patients with somatoform pain disorders who also meet the criteria of functional pain syndromes and the extent to which patients with somatoform pain disorders also show enhanced pain sensitivity.

Methods

Data on pain sensitivity in 120 hospitalized patients were obtained by means of two algometric methods. The group of patients with somatoform pain disorders was further divided into two subsets: patients with and those without a co-diagnosis of a functional pain syndrome. Patients with nociceptive pain served as control group.

Results

Of the 120 in-patients selected, 67 fulfilled the criteria of a somatoform pain disorder of which 41 (61%) also met the co-diagnosis of a functional pain syndrome. Patients with somatoform pain disorder differed from controls in that they showed enhanced pain sensitivity, irrespective of whether a functional pain syndrome was concomitantly present (P< .001).

Conclusions

Somatoform pain disorders show considerable overlap with functional pain syndromes, including enhanced pain sensitivity. This suggests the relevance of integrating somatosensory aspects of pain into a modified understanding of somatoform pain disorders.     

Uncomplicated oocyte donation pregnancies are associated with a higher incidence of human leukocyte antigen alloantibodies

Background

Fetuses in pregnancies conceived after oocyte donation (OD) have a higher degree of antigeneic dissimilarity with the mother compared to semi-allogeneic fetuses after natural conception. We questioned whether this leads to higher level of HLA antibody formation in OD pregnancies.

Method

Uncomplicated pregnancies after OD were compared with pregnancies conceived either spontaneously or by IVF. We calculated the number of HLA- and epitope mismatches. Maternal sera were screened for HLA antibodies with ELISA; child HLA specific antibody production was determined using CDC and Luminex with single antigen beads for class I and II.

Results

A significantly (p < 0.0001) higher incidence of HLA antibody production was observed in women conceiving after OD (69%) compared to non-donor pregnancies (24–25%). The antibody formation was positively correlated with the number of fetomaternal antigen (Spearman’s rho 0.95, p < 0.0001) and epitope mismatches (Spearman’s rho 0.91, p < 0.0001). The number of HLA-DR mismatches between women and child was an independent risk factor for the production of HLA class I specific alloantibodies.

Conclusion

Women conceiving after OD have a higher risk of developing child-specific HLA antibodies; the higher the number of immunogenetic differences, the higher the chance these antibodies are formed. The high incidence of antibody production also strongly depends upon the number of HLA-DR mismatches. Despite the stronger antibody response, OD was associated with uncomplicated pregnancy in cases included in this study.     

Viral Infection and Respiratory Exacerbation in Children: Results from a Local German Pediatric Exacerbation Cohort

Respiratory viruses play an important role in asthma exacerbation, and early exposure can be involved in recurrent bronchitis and the development of asthma. The exact mechanism is not fully clarified, and pathogen-to-host interaction studies are warranted to identify biomarkers of exacerbation in the early phase. Only a limited number of international exacerbation cohorts were studied. Here, we have established a local pediatric exacerbation study in Germany consisting of children with asthma or chronic, recurrent bronchitis and analyzed the viriome within the nasopharyngeal swab specimens derived from the entire cohort (n = 141). Interestingly, 41% of exacerbated children had a positive test result for human rhinovirus (HRV)/human enterovirus (HEV), and 14% were positive for respiratory syncytial virus (RSV). HRV was particularly prevalent in asthmatics (56%), wheezers (50%), and atopic (66%) patients. Lymphocytes were decreased in asthmatics and in HRV-infected subjects, and patients allergic to house dust mites were more susceptible to HRV infection. Our study thus confirms HRV infection as a strong ‘biomarker’ of exacerbated asthma. Further longitudinal studies will show the clinical progress of those children with a history of an RSV or HRV infection. Vaccination strategies and novel treatment guidelines against HRV are urgently needed to protect those high-risk children from a serious course of disease.     

O2 consumption,aerobic glycolysis and tissue phosphagen content during activation of the NA+/K+ pump in rat portal vein

Oxygen consumption, lactate production and tissue contents of ATP, phosphocreatine (PCr) and lactate were measured following readdition of K⁺ to K⁺-depleted rat portal veins, in order to study the energy turnover associated with Na⁺/K⁺ pumping. During incubation in K⁺-free medium at 37° C spontaneous contractions disappeared in 10–20 min. Readdition of K⁺ (5.9 mM) after 40 min K⁺-free incubation caused hyperpolarization of the cell membrane for the first 5–10 min and then gradual depolarization with return of spontaneous action potentials and contractions by 10–20 min. During the first 4–6 min after K⁺ readdition aerobic lactate production was about doubled and then gradually returned to the original level (0.17 mol/min g) at about 20 min. The increase in glycolytic rate was prevented by 1 mM ouabain. In contrast, O₂ consumption (in K⁺-free medium, 0.38 mol/min g) rose by about 10% when K⁺ was added and this increase lasted about 5 min. By 8 min after K⁺ addition the increased glycolysis and oxidative phosphorylation had accounted for each about the same amount of extra ATP generation over that extrapolated from the steady rate before K⁺ addition. The average total increase in ATP turnover in the first 8 min was 15%. During this period there was no change in the cellular content of ATP, PCr, or extractable ADP. The results indicate that Na⁺/K⁺ pumping utilizes a relatively small share of the total energy turnover in the vascular smooth muscle but is to a large extent dependent on aerobic glycolysis and therefore a major site of carbohydrate usage.     

International application of health literacy measures: Adaptation and validation of the newest vital sign in The Netherlands

Objective

The newest vital sign assesses individual reading and numeracy skills. The aim of this study was to create a Dutch version (NVS-D) and to assess its feasibility, reliability, and validity in The Netherlands.

Methods

We performed a qualitative study among experts (n = 27) and patients (n = 30) to develop the NVS-D and to assess its feasibility. For validation, we conducted a quantitative survey (n = 329). Reliability was assessed by Cronbach's alpha. Construct validity was examined by analyzing association patterns. Receiver operating characteristic (ROC) curves determined optimal cut-off scores.

Results

Cronbach's alpha was 0.76. In accordance with a priori hypotheses we found strong associations between NVS-D, general vocabulary, prose literacy and objective health literacy, and weaker associations between NVS-D and subjective health literacy. A score of ≥4 out of 6 best distinguished individuals with adequate versus inadequate health literacy.

Conclusion

The results suggest that the NVS-D is a reliable and valid tool that allows international comparable health literacy research in The Netherlands.

Practice implications

The NVS-D can be applied in research on the role of health literacy in health and health care, and the development of interventions. The methods can be applied in cross-cultural adaptation of health literacy measures in other countries.     

Informed choice on Pap smear still limited by lack of knowledge on the meaning of false-positive or false-negative test results

Objective

Screening for cervical cancer may have favourable or unfavourable effects at the individual level. This study assesses whether invitees in the Netherlands made an informed choice about screen uptake.

Methods

Attached to the invitation letter and the information leaflet, screen invitees were sent a questionnaire. An informed decision was defined as based on decision-relevant knowledge, while the woman's attitude was consistent with her actual screening behaviour.

Results

Of all cervical screen participants, 60% (924/1551) responded to the questionnaire. Decision-relevant knowledge was sufficient in 595 women. Especially knowledge about false-positive and false-negative test results was limited. The attitude towards cervical screening was mainly positive (99%). Requirements for informed decision making were met in 571 (68%) women and in 91% when an alternative cut-off point of sufficient decision-relevant knowledge was applied. Most frequently reported main reasons to attend were early detection of abnormalities (67%) and reassurance in case of a normal smear (22%).

Conclusion

Insufficient decision-relevant knowledge was the main cause of uninformed attendance.

Practice implication

Adequate strategies to provide invitees with sufficient decision-relevant information are still needed, especially regarding false-positive and false-negative test results.     

Human T-cell lymphotrophic virus type-I (HTLV-I) retrovirus and human disease

Human T-cell lymphotrophic virus type-I (HTLV-I) was the first pathogenic retrovirus identified in humans. HTLV-I is now linked to a number of clinical diseases, most notably adult T-cell leukemia/lymphoma and the syndrome known as HTLV-associated myelopathy or tropical spastic paraparesis (HAM/TSP). For the emergency physician practicing among patients from high-risk groups, HTLV-I infection and its associated diseases are presenting an increasing challenge. This report describes its transmission, seroprevalence, associated diseases, and methods to control the spread of this retrovirus.     

Bowel obstruction after laparoscopic and open colon resection for cancer: Results of 5?years of follow-up in a randomized trial

Background

Postoperative bowel obstruction caused by intra-abdominal adhesions occurs after all types of abdominal surgery. It has been suggested that the laparoscopic technique should reduce the risk for adhesion formation and thus for postoperative bowel obstruction. This study was designed to compare the incidence of bowel obstruction in a randomized trial where laparoscopic and open resection for colon cancer was compared.

Methods

A retrospective analysis was performed, collecting data of episodes of bowel obstruction with or without surgery. Only episodes treated in the hospital where the index surgery took place were included. Data for 786 patients were collected for the 5-year period after cancer surgery.

Results

Baseline characteristics for the evaluated laparoscopic (n?=?383) and open (n?=?403) groups were comparable. The cumulative obstruction percentages at 5?years for the open and laparoscopic groups were 6.5 and 5.1% respectively and did not significantly differ from each other. Tumor stage seemed to influence the risk for bowel obstruction: 2.8% in stage I, 6.6% in stage II, and 7% in stage III, but the differences were not significant.

Conclusions

This analysis does not support the hypothesis that laparoscopy leads to fewer episodes of bowel obstruction compared with open surgery.