Stress testing in patients one year after orthotopic cardiac transplantation

To evaluate the circulatory response of the denervated heart to exercise, the authors studied 15 patients with an orthotopic transplanted heart (TH). Mean age was 48 +/- 10 (range twenty-five to sixty-two) years. All patients underwent a symptom-limited bicycle stress testing following a continuous protocol increasing the work load by 30 watts every three minutes. Exercise test was performed 16 +/- 9 months after operation. Fifteen healthy subjects matched for age were used as the control group. There were significant differences (p less than 0.01) in heart rate, at rest, peak exercise, and at five minutes of the recovery period, in maximal oxygen consumption (VO2 max) and in duration of exercise between TH patients and controls. Synchronization between recipient and donor sinoatrial nodes was observed in 10 of 15 patients. A case of silent myocardial ischemia was also observed in a patient with vasculitis and acute rejection. In conclusion, the lack of neural control in TH patients allows them to maintain a normal resting cardiac output but precludes attaining a normal maximum oxygen uptake, despite a normal contractile state. The high resting heart rate due to parasympathetic denervation constitutes an important limiting factor for an adequate chronotropic reserve. Functional capacity of transplanted patients is slightly impaired, but it does not preclude a good quality of life.     

Ganglioglioma anaplásico: diseminación leptomeníngea cervico-dorso-lumbar. A propósito de un caso

Gangliogliomas are well-differentiated, slow-growing tumors. The majority are grade I of WHO. It appears predominantly in children and young adults. Most are located at the temporal lobe, and as symptomatology more frequent epileptic seizures of difficult pharmacological control. In general, they have a good prognosis after surgical resection. The anaplasic variant, considered to be grade III of the WHO, presents greater clinical and radiological aggressiveness. Leptomeningeal dissemination is exceptional in these types of tumors, but when diagnosed it presents a rapidly progressive and fatal course for the patient.     

A Study in First-Episode Psychosis Patients: Does Angiotensin I-Converting Enzyme Activity Associated With Genotype Predict Symptom Severity Reductions After Treatment With Atypical Antipsychotic Risperidone?

BackgroundOur previous studies showed increased angiotensin I-converting enzyme (ACE) activity in chronic schizophrenia patients compared with healthy control (HC) volunteers, and the relevance of combining ACE genotype and activity for predicting schizophrenia was suggested.MethodsACE activity was measured in plasma of ACE insertion/deletion (I/D) genotyped HC volunteers (n = 53) and antipsychotic-naïve first-episode psychosis (FEP) patients (n = 45) assessed at baseline (FEB-B) and also after 2 months (FEP-2M) of treatment with the atypical antipsychotic risperidone.ResultsACE activity measurements showed significant differences among HC, FEP-B, and FEP-2M groups (F = 5.356, df = 2, P = .005) as well as between HC and FEP-2M (post-hoc Tukey’s multiple comparisons test, P = .004). No correlation was observed for ACE activity increases and symptom severity reductions in FEP as assessed by total Positive and Negative Syndrome Scale (r = −0.131, P = .434). FEP subgrouped by ACE I/D genotype showed significant ACE activity increases, mainly in the DD genotype subgroup. No correlation between ACE activity and age was observed in FEP or HC groups separately (r = 0.210, P = .392), but ACE activity level differences observed between these groups were influenced by age.ConclusionsThe importance of measuring the ACE activity in blood plasma, associated with ACE I/D genotyping to support the follow-up of FEP patients, did not show correlation with general symptom amelioration in the present study. However, new insights into the influence of age and I/D genotype for ACE activity changes in FEP individuals upon treatment was demonstrated.     

Meta‐analysis of Duct‐to‐duct versus Roux‐en‐Y biliary reconstruction following liver transplantation for primary sclerosing cholangitis

This meta‐analysis aimed to compare outcomes following bile duct reconstruction in patients with primary sclerosing cholangitis (PSC) undergoing liver transplantation depending on whether duct‐to‐duct or Roux‐en‐Y anastomosis was utilized. An electronic search was performed of the MEDLINE, EMBASE, PubMed databases using both subject headings (MeSH) and truncated word searches. Pooled risk ratios and mean difference were calculated using the fixed‐effects and random‐effects models for meta‐analysis. Ten studies including 910 patients met the inclusion criteria. There was no difference in the overall incidence of biliary strictures between the two groups [odds ratio (OR) 1.06 (0.68, 1.66); (P = 0.80)]. The anastomotic stricture rate was similar, [OR 1.18 (0.56, 2.50); (P = 0.67)]. Ascending cholangitis was higher in the Roux–en‐Y group [OR 2.91 (1.17, 7.23); (P = 0.02)]. Anastomotic bile leak rates, graft survival, PSC recurrence and number of patients diagnosed with cholangiocarcinoma following transplantation were comparable between both groups. Duct‐to‐duct and Roux‐en‐Y reconstruction had comparable outcomes. Both techniques are associated with similar incidence of biliary stricture. The bilioenteric reconstruction was associated with a higher risk of cholangitis. The incidence of de novo cholangiocarcinoma was similar in both groups. Duct‐to‐duct reconstruction should be considered when feasible in patients with PSC.     

EFFECTIVENESS OF A MOTOR CONTROL THERAPEUTIC EXERCISE PROGRAM COMBINED WITH MOTOR IMAGERY ON THE SENSORIMOTOR FUNCTION OF THE CERVICAL SPINE: A RANDOMIZED CONTROLLED TRIAL

Background

Motor control therapeutic exercise (MCTE) for the neck is a motor relearning program that emphasizes the coordination and contraction of specific neck flexor, extensor, and shoulder girdle muscles. Because motor imagery (MI) improves sensorimotor function and it improves several motor aspects, such as motor learning, neuromotor control, and acquisition of motor skills, the authors hypothesized that a combination of MCTE and MI would improve the sensorimotor function of the cervical spine more effectively than a MCTE program alone.

Purpose

The purpose of this study was to investigate the influence of MI combined with a MCTE program on sensorimotor function of the craniocervical region in asymptomatic subjects.

Study Design

This study was a single‐blinded randomized controlled trial.

Methods

Forty asymptomatic subjects were assigned to a MCTE group or a MCTE+MI group. Both groups received the same MCTE program for the cervical region (60 minutes), but the MCTE+MI group received an additional intervention based on MI (15 minutes). The primary outcomes assessed were craniocervical neuromotor control (activation pressure value and highest pressure value), cervical kinesthetic sense (joint position error [JPE]), and the subjective perception of fatigue after effort.

Results

Intra‐group significant differences were obtained between pre‐ and post interventions for all evaluated variables (p<0.01) in the MCTE+MI and MCTE groups, except for craniocervical neuromotor control and the subjective perception of fatigue after effort in the MCTE group. In the MCTE+MI group a large effect size was found for craniocervical neuromotor control (d between ‐0.94 and ‐1.41), cervical kinesthetic sense (d between 0.97 and 2.14), neck flexor muscle endurance test (d = ‐1.50), and subjective perception of fatigue after effort (d = 0.79). There were significant inter‐group differences for the highest pressure value, joint position error (JPE) extension, JPE left rotation, and subjective perception of fatigue after effort.

Conclusion

The combined MI and MCTE intervention produced statistically significant changes in sensorimotor function variables of the craniocervical region (highest pressure value, JPE extension and JPE left rotation) and the perception of subjective fatigue compared to MCTE alone. Both groups showed statistically significant changes in all variables measured, except for craniocervical neuromotor control and the subjective perception of fatigue after effort in the MCTE group

Level of Evidence

1b     

Links that speak: The global language network and its association with global fame

Languages vary enormously in global importance because of historical, demographic, political, and technological forces. However, beyond simple measures of population and economic power, there has been no rigorous quantitative way to define the global influence of languages. Here we use the structure of the networks connecting multilingual speakers and translated texts, as expressed in book translations, multiple language editions of Wikipedia, and Twitter, to provide a concept of language importance that goes beyond simple economic or demographic measures. We find that the structure of these three global language networks (GLNs) is centered on English as a global hub and around a handful of intermediate hub languages, which include Spanish, German, French, Russian, Portuguese, and Chinese. We validate the measure of a language’s centrality in the three GLNs by showing that it exhibits a strong correlation with two independent measures of the number of famous people born in the countries associated with that language. These results suggest that the position of a language in the GLN contributes to the visibility of its speakers and the global popularity of the cultural content they produce.Of the thousands of languages that have ever been spoken, only a handful have become influential enough to be considered global languages. However, how do we measure the global influence of a language? What are the implications of a world in which only a handful of languages are globally influential?In the past, researchers have used a variety of measures to determine the global influence of a language. Several studies have relied on measures that proxy the global influence of a language using the population and wealth of its speakers (1–4). While wealth and population approximate a language’s influence, as the dissemination of a language has historically required a strong power base (5), such measures fail to capture the global influence of a language: often the speakers of a language, and their wealth, are locally concentrated, making the language locally influential rather than globally influential.An alternative method to measure the global influence of a language is to focus on who speaks that language, and in particular, on how connected the speakers of that language are. In the words of linguist David Crystal, “Why a language becomes a global language has little to do with the number of people who speak it. It is much more to do with who those speakers are.” (5) In the past, Latin was the pan-European language, not because it was the mother tongue of most Europeans, but because it was the language of the Roman Empire and later the language of the Catholic Church, scholars, and educators (5). The use of Latin by well-connected elites set it apart from other languages and helped Latin endure as a universal language for more than 1,000 years.However, can we use these ideas to identify which modern languages are globally influential? If global languages are those connecting international elites, then we can identify the global languages associated with particular elites by mapping their networks of multilingual coexpressions. Examples of multilingual coexpressions include book translations, edits to multiple language editions of Wikipedia, and posting short messages on Twitter (“tweets”) in multiple languages. These coexpressions define networks (Fig. 1) that—even though not representative of the world’s general population—represent a coarse map of the links connecting the elites that participate of these three important global forums, as social connections often require a shared language.Open in a separate windowFig. 1.Visualizations of the three GLNs. The three GLNs contain all language connections that involve at least six users (Twitter and Wikipedia) or six translations and that are significant with P < 0.01.In this paper, we map the global language networks (GLNs) expressed in three large records of linguistic expression, and use the structure of these networks to determine the degree to which each language is global. First, we look at a collection of more than 2.2 million book translations compiled by UNESCO’s Index Translationum project. This dataset allows us to map the network of book translations, which are produced by individuals with a high literary capacity (authors and professional translators) and are shaped by market forces, such as the demand for books in different languages. Each translation from one language to another forms a connection. Next, we map the network of linguistic coexpressions expressed by the community of digitally engaged knowledge specialists that edit Wikipedia. Here, two languages are connected when users that edit an article in one Wikipedia language edition are significantly more likely to also edit an article in another language edition. Finally, we map the network of linguistic coexpressions expressed in Twitter. Here, two languages are connected when users that tweet in a language are also significantly more likely to tweet in another language.These three networks allow us to map the paths of direct and indirect communication between speakers from different languages. Our method formalizes the intuition that certain languages are disproportionately influential because they provide direct and indirect paths of translation among most of the world’s other languages. For example, it is easy for an idea conceived by a Spaniard to reach an Englishman through bilingual speakers of English and Spanish. An idea conceived by a Vietnamese speaker, however, might only reach a Mapudungun speaker in south-central Chile through a circuitous path that connects bilingual speakers of Vietnamese and English, English and Spanish, and Spanish and Mapudungun. In both cases, however, English and Spanish are still involved in the flow of information, indicating that they act as global languages. In the first example, Spanish and English have a direct involvement because communication is flowing among their speakers. In the latter case, the involvement is indirect and emerges from the lack of speakers that can communicate in both Vietnamese and Mapudungun. These indirect connections make multilingual speakers of global languages globally influential, as they mediate the flow of information not only among each other, but also, among people with whom they do not share a language (6).     

Contrasting dynamic responses in vivo of the Bcl-xL and Bim erythropoietic survival pathways

Survival signaling by the erythropoietin (Epo) receptor (EpoR) is essential for erythropoiesis and for its acceleration in hypoxic stress. Several apparently redundant EpoR survival pathways were identified in vitro, raising the possibility of their functional specialization in vivo. Here we used mouse models of acute and chronic stress, including a hypoxic environment and β-thalassemia, to identify two markedly different response dynamics for two erythroblast survival pathways in vivo. Induction of the antiapoptotic protein Bcl-x(L) is rapid but transient, while suppression of the proapoptotic protein Bim is slower but persistent. Similar to sensory adaptation, however, the Bcl-x(L) pathway "resets," allowing it to respond afresh to acute stress superimposed on a chronic stress stimulus. Using "knock-in" mouse models expressing mutant EpoRs, we found that adaptation in the Bcl-x(L) response occurs because of adaptation of its upstream regulator Stat5, both requiring the EpoR distal cytoplasmic domain. We conclude that survival pathways show previously unsuspected functional specialization for the acute and chronic phases of the stress response. Bcl-x(L) induction provides a "stop-gap" in acute stress, until slower but permanent pathways are activated. Furthermore, pathologic elevation of Bcl-x(L) may be the result of impaired adaptation, with implications for myeloproliferative disease mechanisms.