228 research outputs found
Procedural results and acute complications in stenting native and recurrent coarctation of the aorta in patients over 4 years of age: A multi-institutional study
Background: We report a multi-institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta. Methods and Results: Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean = 18.1 years). Successful reduction in the post stent gradient (0.8 was achieved in 97.9% of procedures. There was significant improvement ( P < 0.01) in pre versus post stent coarctation dimensions (7.4 mm Β± 3.0 mm vs. 14.3 Β± 3.2mm), systolic gradient (31.6 mm Hg Β± 16.0 mm Hg vs. 2.7 mm Hg Β± 4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43 Β± 0.17 vs. 0.85 Β± 0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation ( n = 6), intimal tears ( n = 8), and dissections ( n = 9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration ( n = 28), and balloon rupture ( n = 13). Peripheral vascular complications included cerebral vascular accidents (CVA) ( n = 4), peripheral emboli ( n = 1), and significant access arterial injury ( n = 13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% ( P < 0.001) was observed in procedures performed after January 2002. Conclusions: Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta. Β© 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56159/1/21164_ftp.pd
Arterial wall dynamics
An early change in arterial wall dynamics introduced as a novel risk factor for cardiovascular events in various populations is discussed in this review. Distensibility of an artery segment as reflection of the mechanical stress affecting the arterial wall during the cardiac cycle has been intensively studied recent years through the technological development of high-resolution ultrasound systems. A decrease of arterial distensibility (i.e. increase of arterial wall stiffness) seems to be a common pathological mechanism for many factors associated with cerebrovascular and cardiovascular diseases. It is difficult to define the role of each factor affecting the arterial wall motions dependent mainly on the left ventricle, intra arterial pressure and blood volume, endothelium function, smooth muscle tone and neural control mechanism. The calculations of arterial compliance, elastic modulus, augmentation pressure, stiffness and intima-media thickness may help to identify the role of each mechanism if they are based on high-tech measurements of arterial wall. The role of nervous regulation of blood vessel's tone in this process is not clear. Our studies show the strong correlation between autonomic imbalance and increase of carotid arterial distensibility in young patients. Various possible relationships between changes in the dynamic artery wall properties and neural regulation are discussed.publishersversionPeer reviewe
results from a cross-sectional study using respondent-driven sampling in eight German cities (2011β14)
Background People who inject drugs (PWID) are at increased risk of acquiring
and transmitting HIV and Hepatitis C (HCV) due to sharing injection
paraphernalia and unprotected sex. To generate seroprevalence data on HIV and
HCV among PWID and related data on risk behaviour, a multicentre sero- and
behavioural survey using respondent driven sampling (RDS) was conducted in
eight German cities between 2011 and 2014. We also evaluated the feasibility
and effectiveness of RDS for recruiting PWID in the study cities. Methods
Eligible for participation were people who had injected drugs within the last
12 months, were 16 years or older, and who consumed in one of the study
cities. Participants were recruited, using low-threshold drop-in facilities as
study sites. Initial seeds were selected to represent various sub-groups of
people who inject drugs (PWID). Participants completed a face-to-face
interview with a structured questionnaire about socio-demographics, sexual and
injecting risk behaviours, as well as the utilisation of health services.
Capillary blood samples were collected as dried blood spots and were
anonymously tested for serological and molecular markers of HIV and HCV. The
results are shown as range of proportions (min. and max. values (%)) in the
respective study cities. For evaluation of the sampling method we applied
criteria from the STROBE guidelines. Results Overall, 2,077 PWID were
recruited. The range of age medians was 29β41 years, 18.5β35.3 % of
participants were female, and 9.2β30.6 % were foreign born. Median time span
since first injection were 10β18 years. Injecting during the last 30 days was
reported by 76.0β88.4 % of participants. Sharing needle/syringes (last 30
days) ranged between 4.7 and 22.3 %, while sharing unsterile paraphernalia
(spoon, filter, water, last 30 days) was reported by 33.0β43.8 %. A majority
of participants (72.8β85.8 %) reported incarceration at least once, and
17.8β39.8 % had injected while incarcerated. Between 30.8 and 66.2 % were
currently in opioid substitution therapy. Unweighted HIV seroprevalence ranged
from 0β9.1 %, HCV from 42.3β75.0 %, and HCV-RNA from 23.1β54.0 %. The
implementation of RDS as a recruiting method in cooperation with low-threshold
drop in facilities was well accepted by both staff and PWID. We reached our
targeted sample size in seven of eight cities. Conclusions In the recruited
sample of mostly current injectors with a long duration of injecting drug use,
seroprevalence for HIV and HCV varied greatly between the city samples. HCV
was endemic among participants in all city samples. Our results demonstrate
the necessity of intensified prevention strategies for blood-borne infections
among PWID in Germany
A simplified study of trans-mitral Doppler patterns
<p>Abstract</p> <p>Background</p> <p>Trans-mitral Doppler produces complex patterns with a great deal of variability. There are several confusing numerical measures and indices to study these patterns. However trans-mitral Doppler produces readymade data visualization by pattern generation which could be interpreted by pattern analysis. By following a systematic approach we could create an order and use this tool to study cardiac function.</p> <p>Presentation of the hypothesis</p> <p>In this new approach we eliminate the variables and apply pattern recognition as the main criterion of study. Proper terminologies are also devised to avoid confusion. In this way we can get some meaningful information.</p> <p>Testing the hypothesis</p> <p>Trans-mitral Doppler should be seen as patterns rather than the amplitude. The hypothesis can be proven by logical deduction, extrapolation and elimination of variables. Trans-mitral flow is also analyzed <it>vis-Γ -vis </it>the Starling's Law applied to the left atrium.</p> <p>Implications of the hypothesis</p> <p>Trans-mitral Doppler patterns are not just useful for evaluating diastolic function. They are also useful to evaluate systolic function. By following this schema we could get useful diagnostic information and therapeutic options using simple pattern recognition with minimal measurements. This simplified but practical approach will be useful in day to day clinical practice and help in understanding cardiac function better. This will also standardize research and improve communication.</p
Ultrasound Imaging Versus Morphopathology in Cardiovascular Diseases: The Heart Failure
This review article summarizes the results of histopathological studies to assess heart failure in humans. Different histopathological features underlying the clinical manifestations of heart failure are reviewed. In addition, the present role of echocardiographic techniques in assessing the failing heart is briefly summarized
Emergence and Persistence of Minor Drug-Resistant HIV-1 Variants in Ugandan Women after Nevirapine Single-Dose Prophylaxis
BACKGROUND: Nevirapine (NVP) single-dose is still a widely used antiretroviral prophylaxis for the prevention of vertical HIV-1 transmission in resource-limited settings. However, the main disadvantage of the Non-nucleoside Reverse Transcriptase Inhibitor (NNRTI) NVP is the rapid selection of NVP-resistant virus with negative implications for subsequent NNRTI-based long-term antiretroviral therapy (ART). Here, we analysed the emergence of drug-resistant HIV-1 including minor variants in the early phase after NVP single-dose prophylaxis and the persistence of drug-resistant virus over time. METHODS AND FINDINGS: NVP-resistant HIV-1 harbouring the K103N and/or Y181C resistance mutations in the HIV-1 reverse transcriptase gene was measured from 1 week up to 18 months after NVP single-dose prophylaxis in 29 Ugandan women using allele-specific PCR assays capable of detecting drug-resistant variants representing less than 1% of the whole viral population. In total, drug-resistant HIV-1 was identified in 18/29 (62%) women; rates increased from 18% to 38% and 44% at week 1, 2, 6, respectively, and decreased to 18%, 25%, 13% and 4% at month 3, 6, 12 and 18, respectively. The proportion of NVP-resistant virus of the total viral population was significantly higher in women infected with subtype D (median 40.5%) as compared to subtype A (median 1.3%; pβ=β0.032, Mann-Whitney U test). 33% of resistant virus was not detectable at week 2 but was for the first time measurable 6-12 weeks after NVP single-dose prophylaxis. Three (10%) women harboured resistant virus in proportions >10% still at month 6. CONCLUSIONS: Current WHO guidelines recommend an additional postnatal intake of AZT and 3TC for one week to avoid NVP resistance formation. Our findings indicate that a 1-week medication might be too short to impede the emergence of NVP resistance in a substantial proportion of women. Furthermore, subsequent NNRTI-based ART should not be started earlier than 12 months after NVP single-dose prophylaxis
Evaluation of an open access echocardiography service in the Netherlands: a mixed methods study of indications, outcomes, patient management and trends
Background: In our region (Eastern South Limburg, The Netherlands) an open access echocardiography service started in 2002. It was the first service of this kind in The Netherlands. Our study aims were: (1) to evaluate demand for the service, participation, indications, echocardiography outcomes, and management by the general practitioner (GP); (2) to analyse changes in indications and outcomes over the years. Methods: (1) Data from GP request forms, echocardiography reports and a retrospective GP questionnaire on management (response rate 83%) of 625 consecutive patients (Dec. 2002-March 2007) were analysed cross-sectionally. (2) For the analysis of changes over the years, data from GP request forms and echocardiography reports of the first and last 250 patients that visited the service between Dec. 2002 and Feb. 2008 (n = 1001) were compared. Results: The echocardiography service was used by 81% of the regional GPs. On average, a GP referred one patient per year to the service. Intended indications for the service were dyspnoea (32%), cardiac murmur (59%), and peripheral oedema (17%). Of the other indications (22%), one-third was for evaluation of suspected left ventricular hypertrophy (LVH). Expected outcomes were left ventricular dysfunction (LVD) (43%, predominantly diastolic) and valve disease (25%). We also found a high proportion of LVH (50%). Only 24% of all echocardiograms showed no relevant disease. The GP followed the cardiologist's advice to refer the patient for further evaluation in 71%. In recent patients, more echocardiography requests were done for 'cardiac murmur' and 'other' indications, but less for 'dyspnoea'. The proportions of patients with LVD, LVH and valve disease decreased and the proportion of patients with no relevant disease increased. The number of advices by the cardiologists increased. Conclusion: Overall, GPs used the open access echocardiography service efficiently (i. e. with a high chance of finding relevant pathology), but efficiency decreased slightly over the years. To meet the needs of the GPs, indications might be widened with 'suspicion LVH'. Further specification of the indications for open access echocardiography-by defining a stepwise diagnostic approach including ECG and (NT-pro)BNP-might improve the service
Prevalence of Transmitted Drug Resistance and Impact of Transmitted Resistance on Treatment Success in the German HIV-1 Seroconverter Cohort
BACKGROUND: The aim of this study is to analyse the prevalence of transmitted drug resistance, TDR, and the impact of TDR on treatment success in the German HIV-1 Seroconverter Cohort. METHODS: Genotypic resistance analysis was performed in treatment-naΓ―ve study patients whose sample was available 1,312/1,564 (83.9% October 2008). A genotypic resistance result was obtained for 1,276/1,312 (97.3%). The resistance associated mutations were identified according to the surveillance drug resistance mutations list recommended for drug-naΓ―ve patients. Treatment success was determined as viral suppression below 500 copies/ml. RESULTS: Prevalence of TDR was stable at a high level between 1996 and 2007 in the German HIV-1 Seroconverter Cohort (Nβ=β158/1,276; 12.4%; CI(wilson) 10.7-14.3; p(for trend)β=β0.25). NRTI resistance was predominant (7.5%) but decreased significantly over time (CI(Wilson): 6.2-9.1, p(for trend)β=β0.02). NNRTI resistance tended to increase over time (NNRTI: 3.5%; CI(Wilson): 2.6-4.6; p(for trend)=β0.07), whereas PI resistance remained stable (PI: 3.0%; CI(Wilson): 2.1-4.0; p(for trend)β=β0.24). Resistance to all drug classes was frequently caused by singleton resistance mutations (NRTI 55.6%, PI 68.4%, NNRTI 99.1%). The majority of NRTI-resistant strains (79.8%) carried resistance-associated mutations selected by the thymidine analogues zidovudine and stavudine. Preferably 2NRTI/1PIr combinations were prescribed as first line regimen in patients with resistant HIV as well as in patients with susceptible strains (susceptible 45.3%; 173/382 vs. resistant 65.5%; 40/61). The majority of patients in both groups were treated successfully within the first year after ART-initiation (susceptible: 89.9%; 62/69; resistant: 7/9; 77.8%). CONCLUSION: Overall prevalence of TDR remained stable at a high level but trends of resistance against drug classes differed over time. The significant decrease of NRTI-resistance in patients newly infected with HIV might be related to the introduction of novel antiretroviral drugs and a wider use of genotypic resistance analysis prior to treatment initiation
Emergence of Minor Drug-Resistant HIV-1 Variants after Triple Antiretroviral Prophylaxis for Prevention of Vertical HIV-1 Transmission
Background: WHO-guidelines for prevention of mother-to-child transmission of HIV-1 in resource-limited settings recommend complex maternal antiretroviral prophylaxis comprising antenatal zidovudine (AZT), nevirapine single-dose (NVP-SD) at labor onset and AZT/lamivudine (3TC) during labor and one week postpartum. Data on resistance development selected by this regimen is not available. We therefore analyzed the emergence of minor drug-resistant HIV-1 variants in Tanzanian women following complex prophylaxis. Method: 1395 pregnant women were tested for HIV-1 at Kyela District Hospital, Tanzania. 87/202 HIV-positive women started complex prophylaxis. Blood samples were collected before start of prophylaxis, at birth and 1β2, 4β6 and 12β16 weeks postpartum. Allele-specific real-time PCR assays specific for HIV-1 subtypes A, C and D were developed and applied on samples of mothers and their vertically infected infants to quantify key resistance mutations of AZT (K70R/T215Y/T215F), NVP (K103N/Y181C) and 3TC (M184V) at detection limits of,1%. Results: 50/87 HIV-infected women having started complex prophylaxis were eligible for the study. All women took AZT with a median duration of 53 days (IQR 39β64); all women ingested NVP-SD, 86 % took 3TC. HIV-1 resistance mutations were detected in 20/50 (40%) women, of which 70 % displayed minority species. Variants with AZT-resistance mutations were found in 11/50 (22%), NVP-resistant variants in 9/50 (18%) and 3TC-resistant variants in 4/50 women (8%). Three wome
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