Duplex–assisted internal carotid artery balloon angioplasty and stent placement: A novel approach to minimize or eliminate the use of contrast material

BackgroundCarotid artery balloon angioplasty and stenting (CBAS) is emerging as an acceptable alternative to carotid endarterectomy in selected high-risk patients. Conversely, patients with pre-existing renal impairment, diabetes, or both may be harmed by the nephrotoxic contrast agents required during CBAS. We attempted to limit or eliminate the use of contrast material during CBAS.MethodsEighteen patients with severe carotid stenoses (>70%) underwent CBAS at our institution over the last 12 months with duplex scan-assisted CBAS. Of these, 12 were primary procedures, and 6 were performed for carotid re-stenosis. Fourteen patients (78%) were neurologically asymptomatic. The average age of these patients was 75 ± 11 years (range, 44–92 years). Hypertension, chronic renal insufficiency (serum creatinine level ≥1.5 mg/dL), coronary artery disease, diabetes, and smoking were present in 89%, 67%, 59%, 33%, and 28% of patients, respectively. Preoperative duplex carotid mapping was performed in all cases. All procedures were performed with patients under local anesthesia and light sedation.ResultsAn ATL HDI 5000 scanner with the SonoCT feature was used. The common femoral artery was cannulated with a single-entry needle under direct ultrasound visualization. Fluoroscopy was used to assist passage of the guidewire into the aorta and the common carotid artery. In only four cases (22%) was an aortic arch angiogram obtained. Selective catheterization of the internal and external carotid arteries was performed under ultrasound guidance. The distal cerebral protection device (17 cases) was placed under fluoroscopic guidance. Balloon width and length were chosen according to ultrasound measurements. Balloon and stent deployment were successfully achieved with ultrasound guidance alone in all cases. Appropriate stent apposition and resolution of the stenosis was confirmed by duplex scanning in all cases. Five patients (28%) were noted to have low (<100 mL/min) internal carotid artery volume flow after stent deployment (range, 20–88 mL/min; mean ± SD, 50 ± 25 mL/min). The internal carotid artery volume flow increased immediately after Filterwire retrieval in all cases and ranged from 136 to 400 mL/min (mean, 245 ± 107 mL/min). This increase was statistically significant (P < .02). No ipsilateral strokes or deaths occurred during follow-up from 1 to 12 months (mean follow-up, 5 months).ConclusionsDuplex scan-assisted CBAS is feasible and may reduce the need for intra-arterial contrast injection in selected patients deemed at high risk for renal failure from nephrotoxic contrast material. Additional advantages include direct visualization of the puncture site, precise position of the balloon and stent, and B-mode and hemodynamic confirmation of the adequacy of the technique

Cholinergic Modulation of Locomotion and Striatal Dopamine Release Is Mediated by α6α4* Nicotinic Acetylcholine Receptors

Dopamine (DA) release in striatum is governed by firing rates of midbrain DA neurons, striatal cholinergic tone, and nicotinic ACh receptors (nAChRs) on DA presynaptic terminals. DA neurons selectively express α6* nAChRs, which show high ACh and nicotine sensitivity. To help identify nAChR subtypes that control DA transmission, we studied transgenic mice expressing hypersensitive α6^(L9’S*) receptors. α6^(L9’S) mice are hyperactive, travel greater distance, exhibit increased ambulatory behaviors such as walking, turning, and rearing, and show decreased pausing, hanging, drinking, and grooming. These effects were mediated by α6 α4* pentamers, as α6^(L9’S) mice lacking α4 subunits displayed essentially normal behavior. In α6^(L9’S) mice, receptor numbers are normal, but loss of α4 subunits leads to fewer and less sensitive α6* receptors. Gain-of-function nicotine-stimulated DA release from striatal synaptosomes requires α4 subunits, implicating α6α4β2* nAChRs in α6^(L9’S) mouse behaviors. In brain slices, we applied electrochemical measurements to study control of DA release by α6^(L9’S) nAChRs. Burst stimulation of DA fibers elicited increased DA release relative to single action potentials selectively in α6^(L9’S), but not WT or α4KO/ α6^(L9’S), mice. Thus, increased nAChR activity, like decreased activity, leads to enhanced extracellular DA release during phasic firing. Bursts may directly enhance DA release from α6^(L9’S) presynaptic terminals, as there was no difference in striatal DA receptor numbers or DA transporter levels or function in vitro. These results implicate α6α4β2* nAChRs in cholinergic control of DA transmission, and strongly suggest that these receptors are candidate drug targets for disorders involving the DA system

α6* Nicotinic Acetylcholine Receptor Expression and Function in a Visual Salience Circuit

Nicotinic acetylcholine receptors (nAChRs) containing α6 subunits are expressed in only a few brain areas, including midbrain dopamine (DA) neurons, noradrenergic neurons of the locus ceruleus, and retinal ganglion cells. To better understand the regional and subcellular expression pattern of α6-containing nAChRs, we created and studied transgenic mice expressing a variant α6 subunit with green fluorescent protein (GFP) fused in-frame in the M3-M4 intracellular loop. In α6-GFP transgenic mice, α6-dependent synaptosomal DA release and radioligand binding experiments confirmed correct expression and function in vivo. In addition to strong α6* nAChR expression in glutamatergic retinal axons, which terminate in superficial superior colliculus (sSC), we also found α6 subunit expression in a subset of GABAergic cell bodies in this brain area. In patch-clamp recordings from sSC neurons in brain slices from mice expressing hypersensitive α6* nAChRs, we confirmed functional, postsynaptic α6* nAChR expression. Further, sSC GABAergic neurons expressing α6* nAChRs exhibit a tonic conductance mediated by standing activation of hypersensitive α6* nAChRs by ACh. α6* nAChRs also appear in a subpopulation of SC neurons in output layers. Finally, selective activation of α6* nAChRs in vivo induced sSC neuronal activation as measured with c-Fos expression. Together, these results demonstrate that α6* nAChRs are uniquely situated to mediate cholinergic modulation of glutamate and GABA release in SC. The SC has emerged as a potential key brain area responsible for transmitting short-latency salience signals to thalamus and midbrain DA neurons, and these results suggest that α6* nAChRs may be important for nicotinic cholinergic sensitization of this pathway

Incidence and Risk Factors of Serious Adverse Events during Antituberculous Treatment in Rwanda: A Prospective Cohort Study

BACKGROUND: Tuberculosis (TB) and TB-human immunodeficiency virus infection (HIV) coinfection is a major public health concern in resource-limited settings. Although TB treatment is challenging in HIV-infected patients because of treatment interactions, immunopathological reactions, and concurrent infections, few prospective studies have addressed this in sub-Saharan Africa. In this study we aimed to determine incidence, causes of, and risk factors for serious adverse events among patients on first-line antituberculous treatment, as well as its impact on antituberculous treatment outcome. METHODS AND FINDINGS: Prospective observational cohort study of adults treated for TB at the Internal Medicine department of the Kigali University Hospital from May 2008 through August 2009. Of 263 patients enrolled, 253 were retained for analysis: median age 35 (Interquartile range, IQR 28-40), 55% male, 66% HIV-positive with a median CD4 count 104 cells/mm(3) (IQR 44-248 cells/mm(3)). Forty percent had pulmonary TB, 43% extrapulmonary TB and 17% a mixed form. Sixty-four (26%) developed a serious adverse event; 58/167 (35%) HIV-infected vs. 6/86 (7%) HIV-uninfected individuals. Commonest events were concurrent infection (n = 32), drug-induced hepatitis (n = 24) and paradoxical reactions/TB-IRIS (n = 23). HIV-infection (adjusted Hazard Ratio, aHR 3.4, 95% Confidence Interval, CI 1.4-8.7) and extrapulmonary TB (aHR 2, 95%CI 1.1-3.7) were associated with an increased risk of serious adverse events. For TB/HIV co-infected patients, extrapulmonary TB (aHR 2.0, 95%CI 1.1-3.9) and CD4 count <100 cells/mm3 at TB diagnosis (aHR 1.7, 95%CI 1.0-2.9) were independent predictors. Adverse events were associated with an almost two-fold higher risk of unsuccessful treatment outcome at 6 months (HR 1.89, 95%CI 1.3-3.0). CONCLUSION: Adverse events frequently complicate the course of antituberculous treatment and worsen treatment outcome, particularly in patients with extrapulmonary TB and advanced immunodeficiency. Concurrent infection accounts for most events. Our data suggest that deterioration in a patient already receiving antituberculous treatment should prompt an aggressive search for additional infections

Plasma steroid concentrations reflect acute disease severity and normalise during recovery in people hospitalised with COVID-19

Objective: Endocrine systems are disrupted in acute illness, and symptoms reported following coronavirus disease 2019 (COVID-19) are similar to those found with clinical hormone deficiencies. We hypothesised that people with severe acute COVID-19 and with post-COVID symptoms have glucocorticoid and sex hormone deficiencies. Design/Patients: Samples were obtained for analysis from two UK multicentre cohorts during hospitalisation with COVID-19 (International Severe Acute Respiratory Infection Consortium/World Health Organisation [WHO] Clinical Characterization Protocol for Severe Emerging Infections in the UK study), and at follow-up 5 months after hospitalisation (Post-hospitalisation COVID-19 study). Measurements: Plasma steroids were quantified by liquid chromatography–mass spectrometry. Steroid concentrations were compared against disease severity (WHO ordinal scale) and validated symptom scores. Data are presented as geometric mean (SD). Results: In the acute cohort (n = 239, 66.5% male), plasma cortisol concentration increased with disease severity (cortisol 753.3 [1.6] vs. 429.2 [1.7] nmol/L in fatal vs. least severe, p < .001). In males, testosterone concentrations decreased with severity (testosterone 1.2 [2.2] vs. 6.9 [1.9] nmol/L in fatal vs. least severe, p < .001). In the follow-up cohort (n = 198, 62.1% male, 68.9% ongoing symptoms, 165 [121–192] days postdischarge), plasma cortisol concentrations (275.6 [1.5] nmol/L) did not differ with in-hospital severity, perception of recovery, or patient-reported symptoms. Male testosterone concentrations (12.6 [1.5] nmol/L) were not related to in-hospital severity, perception of recovery or symptom scores. Conclusions: Circulating glucocorticoids in patients hospitalised with COVID-19 reflect acute illness, with a marked rise in cortisol and fall in male testosterone. These findings are not observed 5 months from discharge. The lack of association between hormone concentrations and common post-COVID symptoms suggests steroid insufficiency does not play a causal role in this condition

T Regulatory Cells Control Susceptibility to Invasive Pneumococcal Pneumonia in Mice

Streptococcus pneumoniae is an important human pathogen responsible for a spectrum of diseases including pneumonia. Immunological and pro-inflammatory processes induced in the lung during pneumococcal infection are well documented, but little is known about the role played by immunoregulatory cells and cytokines in the control of such responses. We demonstrate considerable differences in the immunomodulatory cytokine transforming growth factor (TGF)-β between the pneumococcal pneumonia resistant BALB/c and susceptible CBA/Ca mouse strains. Immunohistochemistry and flow cytometry reveal higher levels of TGF-β protein in BALB/c lungs during pneumococcal pneumonia that correlates with a rapid rise in lung Foxp3+Helios+ T regulatory cells. These cells have protective functions during pneumococcal pneumonia, because blocking their induction with an inhibitor of TGF-β impairs BALB/c resistance to infection and aids bacterial dissemination from lungs. Conversely, adoptive transfer of T regulatory cells to CBA/Ca mice, prior to infection, prolongs survival and decreases bacterial dissemination from lungs to blood. Importantly, strong T regulatory cell responses also correlate with disease-resistance in outbred MF1 mice, confirming the importance of immunoregulatory cells in controlling protective responses to the pneumococcus. This study provides exciting new evidence for the importance of immunomodulation during pulmonary pneumococcal infection and suggests that TGF-β signalling is a potential target for immunotherapy or drug design

The impact of provider-initiated (opt-out) HIV testing and counseling of patients with sexually transmitted infection in Cape Town, South Africa: a controlled trial

<p>Abstract</p> <p>Background</p> <p>The effectiveness of provider-initiated HIV testing and counseling (PITC) for patients with sexually transmitted infection (STI) in resource-constrained settings are of particular concern for high HIV prevalence countries like South Africa. This study evaluated whether the PITC approach increased HIV testing amongst patients with a new episode of sexually transmitted infection, as compared to standard voluntary counseling and testing (VCT) at the primary care level in South Africa, a high prevalence and low resource setting.</p> <p>Methods</p> <p>The design was a pragmatic cluster-controlled trial with seven intervention and 14 control clinics in Cape Town. Nurses in intervention clinics integrated PITC into standard HIV care with few additional resources, whilst lay counselors continued with the VCT approach in control clinics. Routine data were collected for a six-month period following the intervention in 2007, on new STI patients who were offered and who accepted HIV testing. The main outcome measure was the proportion of new STI patients tested for HIV, with secondary outcomes being the proportions who were offered and who declined the HIV test.</p> <p>Results</p> <p>A significantly higher proportion of new STI patients in the intervention group tested for HIV as compared to the control group with (56.4% intervention versus 42.6% control, p = 0.037). This increase was achieved despite a significantly higher proportion intervention group declining testing when offered (26.7% intervention versus 13.5% control, p = 0.0086). Patients were more likely to be offered HIV testing in intervention clinics, where providers offered the HIV test to 76.8% of new STI patients versus 50.9% in the control group (p = 0.0029). There was significantly less variation in the main outcomes across the intervention clinics, suggesting that the intervention also facilitated more consistent performance.</p> <p>Conclusions</p> <p>PITC was successful in three ways: it increased the proportion of new STI patients tested for HIV; it increased the proportion of new STI patients offered HIV testing; and it delivered more consistent performance across clinics. Recommendations are made for increasing the impact and feasibility of PITC in high HIV prevalence and resource-constrained settings. These include more flexible use of clinical and lay staff, and combining PITC with VCT and other community-based approaches to HIV testing.</p> <p>Trial registration</p> <p>Controlled trial ISRCTN93692532</p