Dependency of blood flow velocity in the middle cerebral artery on end-tidal carbon dioxide partial pressure--a transcranial ultrasound Doppler study

The end-tidal carbon dioxide partial pressure (PCO2) response curves for the flow velocity in the middle cerebral artery were studied in 31 normal subjects with transcranial Doppler techniques. An exponential curve with an exponent of 0.034 mm Hg-1 was found to be a good fit to the recorded data. By means of this relationship, recordings of flow velocity in cerebral arteries can be normalized to a standard value of PCO2. Physiological aspects of cerebrovascular reactivity to PCO2 and the clinical implications of the PCO2 response curve are discussed. The normal material provides a reference for assessing pathological responses.

Potent antiretroviral treatment of HIV-infection results in suppression of the seminal shedding of HIV. The Swiss HIV Cohort Study

OBJECTIVE

The amount of HIV in semen likely influences infectiousness. Antiretroviral therapy decreases HIV-RNA in semen, but data on HIV concentrations in semen in a large cohort of men with suppressed HIV-RNA in blood is unavailable.

METHODS

Male patients with a treatment-induced reduction of HIV-RNA load in plasma below 400 copies/ml were asked to donate a semen and blood sample. Blood and seminal plasma were tested for the presence of HIV-RNA by the NucliSens method (detection limit 400 copies/ml). Seminal cell samples from 67 patients were further analysed for the presence of HIV-DNA using a nested DNA-polymerase chain reaction. Results of RNA and DNA testing in semen were compared with 55 HIV-positive antiretroviral therapy-naive men.

RESULTS

A total of 114 patients participated in the study. Seminal plasma HIV-RNA was detectable in only two patients [1.8%, 95% confidence ratio (CI), 0-4.2%] compared with a detection frequency of 67% in untreated controls [Odds ratio (OR), 0.01; 95% CI, 0-0.03]. Detection of cell-associated HIV-DNA in semen was significantly less frequent (16 versus 38%) in patients receiving suppressive therapy compared with untreated controls (OR, 0.32; 95% CI, 0.12-0.80).

CONCLUSION

In patients with treatment-induced suppression of blood viral load the likelihood of having detectable HIV in semen is very low (< 4%). In addition, seminal shedding of cell-free and cell-associated HIV is significantly lower than in an untreated population of HIV-infected asymptomatic men. On a population basis, this effect of therapy may help to reduce sexual transmission of HIV. However, individual patients may still be infected as evidenced by continued shedding of cells harbouring the HIV provirus.

Accuracy of staging in early oesophageal cancer using high resolution endoscopy and high resolution endosonography: a comparative, prospective, and blinded trial

BACKGROUND AND AIMS

The increasing use of endoscopic resection for curative treatment of early oesophageal cancers requires accurate staging before therapy. In a prospective blinded trial, we compared staging of early oesophageal carcinoma using high resolution endoscopy (HR-E) with staging using high resolution endosonography (HR-EUS).

PATIENTS AND METHODS

A total of 100 patients (89 men, 11 women; mean age 63.9 (10.8) years (range 31-91)) with a suspicion of early oesophageal adenocarcinoma (n = 81) or squamous cell carcinoma (n = 19) were enrolled in the study. After endoscopic staging with high resolution video endoscopy by two experienced endoscopists, HR-EUS was performed by an experienced endosonographer who was blinded to the endoscopic assessment. Results of the staging examinations were correlated with the histology of the resected tumours.

RESULTS

Overall rates for accuracy of the endoscopic and endosonographic staging were 83.4% and 79.6%, respectively. Sensitivity for mucosal tumours (n = 68) was more than 90% (EUS 91.2%, endoscopy 94.1%) while sensitivity for submucosal tumours (n = 25) was lower, at 48% for EUS and 56% for endoscopic staging. A combination of the two techniques increased the sensitivity for submucosal tumours to 60%. Submucosal tumours in the tubular oesophagus were significantly better staged with HR-EUS than submucosal tumours close to the oesophagogastric junction (10/11 v 2/14; p<0.001). Tumours infiltrating the second and third submucosal layers were also more correctly diagnosed than tumours with slight infiltration of the first submucosal layer (sm1).

CONCLUSIONS

The overall diagnostic accuracy of both HR-E and HR-EUS with a 20 MHz miniprobe in early oesophageal cancer was high (approximately 80%), with no significant differences between the two techniques. HR-E and HR-EUS provide a high level of diagnostic accuracy for mucosal tumours and submucosal tumours located in the tubular part of the oesophagus. With submucosal tumours located at the oesophagogastric junction or with infiltration of the first third of the submucosa however, the diagnostic accuracy of both techniques is not yet satisfactory.

Human benefits of animal interventions for zoonosis control

Although industrialized countries have been able to contain recent outbreaks of zoonotic diseases, many resource-limited and transitioning countries have not been able to react adequately. The key for controlling zoonoses such as rabies, echinococcosis, and brucellosis is to focus on the animal reservoir. In this respect, ministries of health question whether the public health sector really benefits from interventions for livestock. Cross-sectoral assessments of interventions such as mass vaccination for brucellosis in Mongolia or vaccination of dogs for rabies in Chad consider human and animal health sectors from a societal economic perspective. Combining the total societal benefits, the intervention in the animal sector saves money and provides the economic argument, which opens new approaches for the control of zoonoses in resource-limited countries through contributions from multiple sectors.

Aptamer-mediated blockade of IL4Rα triggers apoptosis of MDSCs and limits tumor progression

In addition to promoting tumor progression and metastasis by enhancing angiogenesis and invasion, myeloid-derived suppressor cells (MDSC) and tumor-associated macrophage (TAM) also inhibit antitumor T-cell functions and limit the efficacy of immunotherapeutic interventions. Despite the importance of these leukocyte populations, a simple method for their specific depletion has not been developed. In this study, we generated an RNA aptamer that blocks the murine or human IL-4 receptor-α (IL4Rα or CD124) that is critical for MDSC suppression function. In tumor-bearing mice, this anti-IL4Rα aptamer preferentially targeted MDSCs and TAM and unexpectedly promoted their elimination, an effect that was associated with an increased number of tumor-infiltrating T cells and a reduction in tumor growth. Mechanistic investigations of aptamer-triggered apoptosis in MDSCs confirmed the importance of IL4Ra-STAT6 pathway activation in MDSC survival. Our findings define a straightforward strategy to deplete MDSCs and TAMs in vivo, and they strengthen the concept that IL4Rα signaling is pivotal for MDSC survival. More broadly, these findings suggest therapeutic strategies based on IL4Rα signaling blockades to arrest an important cellular mechanism of tumoral immune escape mediated by MDSCs and TAM in cancer.

Comparison of MELD, Child-Pugh, and Emory model for the prediction of survival in patients undergoing transjugular intrahepatic portosystemic shunting

OBJECTIVES

Recently, new prognostic models (Model for End-Stage Liver Disease [MELD model] and Emory score) were proposed for the prediction of survival in transjugular intrahepatic portosystemic shunt (TIPS) patients. Although the MELD model is considered to be superior and has consecutively been applied to priority listing for liver transplantation, these models have never been directly compared in terms of long-term prognosis. We therefore compared the prognostic accuracy of the different models, including the Child-Pugh score, in an unselected cohort of TIPS patients followed long-term.

METHODS

Baseline risk scores for 162 unselected consecutive TIPS patients followed until death (n = 81), liver transplantation, or end of observation (n = 81) (mean follow-up 30.7 +/- 26.4 months) were calculated, and respective concordance- (c-)statistics for the predictive accuracy of 3-, 12-, and 36-month survival for the three models were compared statistically.

RESULTS

All three models predicted short-term (3-month) survival with similar accuracy. The MELD model generated the best c-statistics for both 12-month (c-statistic 0.73, 95% CI = 0.64-0.82) and 36-month survival (c-statistic 0.74, 95% CI = 0.64-0.84). The predictive accuracy of the Emory score was significantly lower (c-statistic for 12-month survival: 0.60, 95% CI = 0.52-0.68, p = 0.012 vs MELD). In the statistical comparison of the MELD and the Child-Pugh model, only a trend favoring MELD for the prediction of 1-yr survival in patients with intestinal bleeding could be observed (MELD: c-statistic 0.78, 95% CI = 0.67-0.89; Child-Pugh: c-statistic 0.67, 95% CI = 0.55-0.80, p = 0.059).

CONCLUSIONS

The MELD model is superior to the Emory score but only slightly superior to the Child-Pugh classification for the prediction of long-term survival in TIPS patients.

A model of animal-human brucellosis transmission in Mongolia

We developed a dynamic model of livestock-to-human brucellosis transmission in Mongolia. The compartmental model considers transmission within sheep and cattle populations and the transmission to humans as additive components. The model was fitted to demographic and seroprevalence data (Rose Bengal test) from livestock and annually reported new human brucellosis cases in Mongolia for 1991-1999 prior to the onset of a mass livestock-vaccination campaign (S19 Brucella abortus for cattle and Rev 1 Brucella melitensis for sheep and goat). The vaccination effect was fitted to livestock- and human-brucellosis data from the first 3 years of the vaccination campaign (2000-2002). Parameters were optimized on the basis of the goodness-of-fit (assessed by the deviance). The simultaneously fitted sheep-human and cattle-human contact rates show that 90% of human brucellosis was small-ruminant derived. Average effective reproductive ratios for the year 1999 were 1.2 for sheep and 1.7 for cattle.

Keypathophysiologic pathways in age-related macular disease

PURPOSE

To review current knowledge of key pathogenetic pathways in age-related macular disease (AMD).

METHODS

Experimental evidence and clinical observations are reviewed.

RESULTS

A number of common downstream pathophysiologic pathways appear to be relevant in AMD manifestations irrespective of primary heterogeneous etiologies. These include sequelae of oxidative damage, retinal pigment epithelium (RPE) cell dysfunction with accumulation of lipofuscin and impairment of lysosomal functions, deposition of subsequently incompletely degraded material at the basal RPE cell side and alterations in Bruch's membrane extracellular matrix, immunologic responses to extracellular material (drusen) with subsequent growth of drusen, induction of choroidal neovascularization as a result of imbalance between anti-angiogenetic and proangiogenetic factors as well as cell death (geographic atrophy) without prior neovascular events.

CONCLUSIONS

Understanding is expanding regarding the sequence of events that lead to early and late lesions in AMD. Therapeutic approaches that focus on the molecular mechanisms are more likely to succeed than currently available treatment options as exemplified by the management of choroidal neovascularisations.

Peptide-conjugated PAMAM dendrimer as a universal DNA vaccine platform to target antigen-presenting cells

DNA-based vaccines hold promise to outperform conventional antigen-based vaccines by virtue of many unique features. However, DNA vaccines have thus far fallen short of expectations, due in part to poor targeting of professional antigen-presenting cells (APC) and low immunogenicity. In this study, we describe a new platform for effective and selective delivery of DNA to APCs in vivo that offers intrinsic immune-enhancing characteristics. This platform is based on conjugation of fifth generation polyamidoamine (G5-PAMAM) dendrimers, a DNA-loading surface, with MHC class II-targeting peptides that can selectively deliver these dendrimers to APCs under conditions that enhance their immune stimulatory potency. DNA conjugated with this platform efficiently transfected murine and human APCs in vitro. Subcutaneous administration of DNA-peptide-dendrimer complexes in vivo preferentially transfected dendritic cells (DC) in the draining lymph nodes, promoted generation of high affinity T cells, and elicited rejection of established tumors. Taken together, our findings show how PAMAM dendrimer complexes can be used for high transfection efficiency and effective targeting of APCs in vivo, conferring properties essential to generate effective DNA vaccines.

In vivo visualization of dendritic cells, macrophages, and microglial cells responding to laser-induced damage in the fundus of the eye

PURPOSE

To study the in vivo response of mononuclear phagocytes (i.e., dendritic cells [DCs] and macrophages [MPhis]) in the posterior eye segment after laser-induced injury, and to gain a better understanding of the role of these cells in inflammatory eye disease.

METHODS

CX(3)CR1(GFP/+) knockin mice were used, in which DCs, MPhis, and microglia cells (microGCs) are constitutively fluorescent. These reporter mice were examined by a confocal scanning laser ophthalmoscope (cSLO) after argon laser coagulation. cSLO was complemented by fluorescence microscopy of retinal flatmounts and eye cryosections, to study cell morphology and location, and by multicolor flow cytometry, to determine the number and identity of the fluorescent cells.

RESULTS

The retina of healthy reporter mice featured abundant fluorescent microGCs. After laser injury to the fundus, these cells accumulated and migrated laterally toward injury after 60 minutes. Distinctly shaped fluorescent cells accumulated within laser spots and were identified by flow cytometry and immunofluorescence microscopy as DCs and MPhis in the retina and choroid. The DCs rapidly disappeared from the retina, whereas the MPhis stayed longer. Choroidal infiltrates were detectable even 35 days after laser injury, in particular in larger spots resulting from higher laser intensity. In addition, nonfluorescent granulocytes were detected in the choroid.

CONCLUSIONS

The synergistic use of ophthalmoscopy, flow cytometry, and immunofluorescence microscopy allows detailed dissection of the in vivo response of mononuclear phagocytes to laser injury of the fundus. The number of microGCs increased in the retina. DCs and MPhis were present in the retina and choroid infiltrate. MPhis and granulocytes persisted in the choroid infiltrate longer than previously thought.

Suxamethonium-induced hyperkalaemia in patients with severe intra-abdominal infections

In nine patients, undergoing repeat operations because of severe intra-abdominal infection developing after major abdominal surgery, serum potassium concentrations were monitored during induction of anaesthesia. Four patients showed an increase of serum potassium ranging from 2.5 to 3.1 mmol/litre above baseline values within 3-6 min after suxamethonium 100 mg i.v. In five patients there was no change. The four patients demonstrating an increase had suffered from pyrexia and leucocytosis for at least 2 weeks. The other five had signs of infection for no more than 9 days. It is concluded that patients with signs of severe intra-abdominal infection lasting longer than 1 week represent an additional category susceptible to suxamethonium-induced hyperkalaemia. They should receive only non-depolarizing muscle relaxants. When the use of suxamethonium is unavoidable, the injection of a non-depolarizing muscle relaxant before the administration of suxamethonium is recommended.

Persistence of brucellosis in pastoral systems

Regarded as a highly contagious, zoonotic disease with worldwide distribution, brucellosis is endemic in many countries and settings and is responsible for a considerable economic and health-related burden. Limited information is available on the persistence and prevalence of brucellosis in pastoral communities, due to the difficulty in gathering information and to their mobility. However, since these communities are economically and culturally dependent on livestock, it is important to further determine the cause of persistent disease and develop possible methods for its management. The two main objectives of this paper are to review the literature, identifying various epidemiological and social factors that affect the persistence of brucellosis in pastoral ecosystems, and determine prevalence estimates within these communities. The general trend of the summarised studies indicates low-level, relatively stable transmission of brucellosis in pastoral areas, when compared to transmission in intensive and semi-intensive peri-urban production systems. A formal mathematical analysis can be undertaken using matrix models or coupled differential equations. This allows an examination of the various conditions under which the number of diseased, infected or exposed animals remains stable. The authors examined an existing mathematical differential equation model for brucellosis in Mongolia for its equilibrium conditions and found it reasonably robust, though clearly more data are needed to estimate threshold densities for brucellosis transmission in other regions of the world. However, the results indicate the importance of livestock demographic determinants for brucellosis persistence. The paper concludes that brucellosis remains largely persistent in pastoral areas of the world, despite (varying) control efforts. Plans to control brucellosis in pastoral settings should include ecological considerations, such as sustaining ecosystem services in pastoral areas. This approach would include placing limitations on livestock stocking density, land reform, improved governance and integrated social and economic development.

Coral reef degradation affects the potential for reef recovery after disturbance

The loss of coral cover is often accompanied by an increase of benthic algae, a decline in biodiversity and habitat complexity. However, it remains unclear how surrounding communities influence the trajectories of re-colonization between pulse disturbance events. Over a 12-month field experiment in the central Red Sea, we examined how healthy (hard-coral dominated) and degraded (algae-dominated) reef areas influence recruitment and succession patterns of benthic reef foundation communities on bare substrates. Crustose coralline algae and other calcifiers were important colonizers in the healthy reef area, promoting the accumulation of inorganic carbon. Contrary, substrates in the degraded area were predominantly colonized by turf algae, lowering the accumulation of inorganic carbon by 178%. While coral larvae settlement similarly occurred in both habitats, degraded areas showed 50% fewer recruits. Our findings suggest that in degraded reefs the replenishment of adult coral populations is reduced due to recruitment inhibition through limited habitat complexity and grazing pressure, thereby restraining reef recovery.

One for all: cobalt-containing polymethacrylates for magnetic ceramics, block copolymerization, unexpected electrochemistry, and stimuli-responsiveness

Functional cobalt-containing homo and block polymers are probed with respect to their redox-induced switchability and as preceramic materials.

Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil)

Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted δ(13)Corg and δ(15)N signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOD rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality.

Palmare winkelstabile Plattenosteosynthese der instabilen distalen Radiusfraktur

Internal fixation of distal radius fractures often shows the problem of secondary dislocation due to dorsal comminution and osteoporosis. Although dorsal plating systems provide good stabilization, the intraoperative control of reduction is difficult in the comminuted area with high incidence for the need of cancellous bone graft. Occurrence of extensor tendon complications including tendonitis and rupture is not uncommon. The use of fixed angle devices by a palmar approach has demonstrated the advantage of better visualization and control at the fracture side. The subchondrale support of the articular surface by fixed angle pegs or screws prevents secondary dislocation allowing early mobilization. Better soft tissue coverage is associated with a low complication rate. 62 patients (average age 55 years) were treated with different fixed angel devices according to the fracture type and underwent retrospective evaluation with mean follow-up of 11 months (6-23 months). According to the AO Classification there were 3 A2, 24 A3, 7 B3, 14 C1, 9 C2 und 5 C3 fractures. The majority beside the B3 types and one C3 fracture were dorsally displaced. All of them showed healing without relevant secondary loss of reduction. Mean DASH score reached 19 points.