Impact of influenza and pneumococcal vaccines on HIV persistence and immune dynamics during suppressive antiretroviral therapy

OBJECTIVE

:We sought to determine if standard influenza and pneumococcal vaccines can be used to stimulate HIV reservoirs during antiretroviral therapy (ART).

DESIGN

:Prospective, randomized, double-blinded, placebo-controlled, crossover trial of two clinically recommended vaccines (influenza and pneumococcal).

METHODS

:Persons with HIV on ART (N = 54) were enrolled in the clinical trial. Blood was collected at baseline and days 2,4,7,14 and 30 postimmunizations. Levels of cellular HIV RNA and HIV DNA were measured by ddPCR. Expression of immunological markers on T cell subsets were measured by flow cytometry. Changes in unspliced cellular HIV RNA from baseline to day 7 postinjection between each vaccine and placebo was the primary outcome.

RESULTS

:Forty-seven participants completed at least one cycle and there were no serious adverse events related to the intervention. We observed no significant differences in the change in cellular HIV RNA after either vaccine compared to placebo at any timepoint. In secondary analyses we observed a transient increase in total HIV DNA levels after influenza vaccine, as well as increased T cell activation and exhaustion on CD4+ T cells after pneumococcal vaccine.

CONCLUSIONS

:Clinically recommended vaccines were safe but did not appear to stimulate the immune system strongly enough to elicit significantly noticeable HIV RNA transcription during ART.Clinicaltrials.gov identifier: NCT02707692.

Identification of system-level features in HIV migration within a host

OBJECTIVE

Identify system-level features in HIV migration within a host across body tissues. Evaluate heterogeneity in the presence and magnitude of these features across hosts.

METHOD

Using HIV DNA deep sequencing data generated across multiple tissues from 8 people with HIV, we represent the complex dependencies of HIV migration among tissues as a network and model these networks using the family of exponential random graph models (ERGMs). ERGMs allow for the statistical assessment of whether network features occur more (or less) frequently in viral migration than might be expected by chance. The analysis investigates five potential features of the viral migration network: (1) bi-directional flow between tissues; (2) preferential migration among tissues in the same biological system; (3) heterogeneity in the level of viral migration related to HIV reservoir size; (4) hierarchical structure of migration; and (5) cyclical migration among several tissues. We calculate the Cohran's Q statistic to assess heterogeneity in the magnitude of the presence of these features across hosts. The analysis adjusts for missing data on body tissues.

RESULTS

We observe strong evidence for bi-directional flow between tissues; migration among tissues in the same biological system; and hierarchical structure of the viral migration network. This analysis shows no evidence for differential level of viral migration with respect to the HIV reservoir size of a tissue. There is evidence that cyclical migration among three tissues occurs less frequent than expected given the amount of viral migration. The analysis also provides evidence for heterogeneity in the magnitude that these features are present across hosts. Adjusting for missing tissue data identifies system-level features within a host as well as heterogeneity in the presence of these features across hosts that are not detected when the analysis only considers the observed data.

DISCUSSION

Identification of common features in viral migration may increase the efficiency of HIV cure efforts as it enables targeting specific processes.

Sex Differences in Human Immunodeficiency Virus Persistence and Reservoir Size During Aging

BACKGROUND

Sex differences in human immunodeficiency virus (HIV) reservoir dynamics remain underexplored.

METHODS

Longitudinal samples from virally suppressed midlife women (n = 59, median age 45 years) and age-matched men (n = 31) were analyzed retrospectively. At each time point, we measured sex hormones (by means of enzyme-linked immunosorbent assay) and cellular HIV DNA and RNA (by means of digital droplet polymerase chain reaction). Number of inducible HIV RNA+ cells, which provides an upper estimate of the replication-competent reservoir, was quantified longitudinally in a different subset of 14 women, across well-defined reproductive stages. Mixed-effects models included normalized reservoir outcomes and sex, time since antiretroviral therapy (ART) initiation, and the sex-by-time interaction as predictors.

RESULTS

At ART initiation, women and men had median (interquartile range [IQR]) CD4+ T-cell counts of 204/μL (83-306/μL) versus 238/μL (120-284/μL), respectively; median ages of 45 (42-48) versus 47 (43-51) years; and median follow-up times of 79.2/μL (60.5-121.1/μL) versus 66.2/μL (43.2-80.6/μL) months. We observed a significant decline of total HIV DNA over time in both men and women (P < .01). However, the rates of change differed significantly between the sexes (P < .01), with women having a significantly slower rate of decline than men, more pronounced with age. By contrast, the levels of inducible HIV RNA increased incrementally over time in women during reproductive aging (P < .01).

CONCLUSIONS

In contrast to men, in whom the HIV reservoir steadily declines with aging, the HIV reservoir in women is more dynamic. Total HIV DNA (including intact and defective genomes) declines more slowly in women than in men, while the inducible HIV RNA+ reservoir, which is highly enriched in replication-competent virus, increases in women after menopause.

Subclinical Cytomegalovirus and Epstein-Barr Virus Shedding Is Associated with Increasing HIV DNA Molecular Diversity in Peripheral Blood during Suppressive Antiretroviral Therapy

Cytomegalovirus (CMV) almost universally infects persons with HIV (PWH), and it is a driver of persistent inflammation and HIV persistence. The mechanisms underlying the association between CMV (and possibly other herpesviruses) and HIV persistence are unclear. Serially collected blood samples were obtained from men who have sex with men (MSM) who started antiretroviral therapy (ART) within 1 year of their estimated date of HIV infection (EDI). Total CMV and Epstein-Barr virus (EBV) DNA were quantified in peripheral blood mononuclear cells by droplet digital PCR (ddPCR). Deep sequencing of the HIV DNA partial env gene was performed, and the dynamics of viral diversity over time were analyzed in relation to CMV and EBV shedding status. In total, 37 MSM PWH were included and followed for a median of 23 months (IQR, 22 to 28). Participants started ART within a median of 3.1 months (IQR, 1.5 to 6.5) after EDI and remained virally suppressed thereafter. A total of 18 participants (48.6%) were classified as high EBV shedders, while 19 (51.4%) were classified as CMV shedders. In longitudinal analyses, normalized molecular diversity levels tended to increase over time among participants with detectable CMV and high EBV DNA (0.03 ± 0.02, P = 0.08), while they significantly declined among participants with no/low viral shedding (-0.04 ± 0.02, P = 0.047, interaction P < 0.01). Subclinical CMV and EBV shedding could contribute to the dynamics of the HIV DNA reservoir during suppressive ART. Whether persistent CMV/EBV replication could be targeted as a strategy to reduce the size of the latent HIV reservoir is an avenue that should be explored.IMPORTANCE As part of this study, we evaluated the molecular characteristics of the HIV DNA reservoir over time during antiretroviral treatment (ART) in relation to those of other chronic viral infections (i.e., cytomegalovirus [CMV] and Epstein-Barr virus [EBV]). We demonstrated that the presence of CMV and high-level EBV DNA in peripheral blood cells was associated with changes in HIV DNA molecular diversity. Specifically, HIV DNA molecular diversity increased over time among participants with detectable CMV and high-level EBV DNA, while it significantly declined among participants with no/low viral shedding. Although the current study design does not allow causality to be inferred, it does support the theory that persistent CMV and EBV shedding could contribute to the dynamics of the HIV DNA reservoir during suppressive ART, even when ART is initiated during the earliest phases of HIV infection.

HIV RNA Rebound in Seminal Plasma after Antiretroviral Treatment Interruption

If strategies currently in development succeed in eradicating HIV reservoirs in peripheral blood and lymphoid tissues, residual sources of virus may remain in anatomic compartments. Paired blood and semen samples were collected from 12 individuals enrolled in a randomized, double-blind, placebo-controlled therapeutic vaccine clinical trial in people with HIV (PWH) who began antiretroviral therapy (ART) during acute or early infection (ClinicalTrials registration no. NCT01859325). After the week 56 visit (postintervention), all participants interrupted ART. At the first available time points after viral rebound, we sequenced HIV-1 env (C2-V3), gag (p24), and pol (reverse transcriptase) regions amplified from cell-free HIV RNA in blood and seminal plasma using the MiSeq Illumina platform. Comprehensive sequence and phylogenetic analyses were performed to evaluate viral population structure, compartmentalization, and viral diversity in blood and seminal plasma. Compared to that in blood, HIV RNA rebound in semen occurred significantly later (median of 66 versus 42 days post-ART interruption, P < 0.01) and reached lower levels (median 164 versus 16,090 copies/ml, P < 0.01). Three of five participants with available sequencing data presented compartmentalized viral rebound between blood and semen in one HIV coding region. Despite early ART initiation, HIV RNA molecular diversity was higher in semen than in blood in all three coding regions for most participants. Higher HIV RNA molecular diversity in the genital tract (compared to that in blood plasma) and evidence of compartmentalization illustrate the distinct evolutionary dynamics between these two compartments after ART interruption. Future research should evaluate whether the genital compartment might contribute to viral rebound in some PWH interrupting ART.IMPORTANCE To cure HIV, we likely need to target the reservoirs in all anatomic compartments. Here, we used sophisticated statistical and phylogenetic methods to analyze blood and semen samples collected from 12 persons with HIV who began antiretroviral therapy (ART) during very early HIV infection and who interrupted their ART as part of a clinical trial. First, we found that HIV RNA rebound in semen occurred significantly later and reached lower levels than in blood. Second, we found that the virus in semen was genetically different in some participants compared to that in blood. Finally, we found increased HIV RNA molecular diversity in semen compared to that in blood in almost all study participants. These data suggest that the HIV RNA populations emerging from the genital compartment after ART interruption might not be the same as those emerging from blood plasma. Future research should evaluate whether the genital compartment might contribute to viral rebound in some people with HIV (PWH) interrupting ART.

Presence of asymptomatic cytomegalovirus and Epstein--Barr virus DNA in blood of persons with HIV starting antiretroviral therapy is associated with non-AIDS clinical events

BACKGROUND

Even with antiretroviral therapy (ART), persons with HIV (PWH) experience increased morbidity and mortality. Cytomegalovirus (CMV) and Epstein--Barr virus (EBV) co-infections likely exacerbate inflammatory-related diseases.

OBJECTIVE

To determine if presence of detectable CMV or EBV DNA in peripheral blood mononuclear cells (PBMC) is associated with non-AIDS events among PWH receiving modern ART.

DESIGN

We performed a case--control study of PWH starting ART and HIV-suppressed at year 1 and thereafter, 140 cases who experienced non-AIDS events and 305 matched controls. Events included myocardial infarction, stroke, malignancy, serious bacterial infection or death.

METHODS

Blood samples were studied pre-ART, 1-year post-ART and pre-event. Controls had an event-free follow-up equal or greater than cases. CMV and EBV DNA levels were measured in PBMC. Conditional logistic regression analysis assessed associations and adjusted for relevant covariates; Spearman's correlations compared CMV and EBV DNA levels with other biomarkers.

RESULTS

CMV DNA was detected in PBMC of 25% of participants, EBV DNA was detected in more than 90%. Higher EBV DNA levels were associated with increased risk of events at all time points (odds ratio (OR) per one IQR = 1.5-1.7, all P < 0.009). At year 1, detectable CMV DNA was associated with increased risk of events in most adjusted models (OR = 1.4-1.8, P values ranging 0.03-0.17). Higher levels of CMV and EBV DNA correlated with multiple inflammatory markers and lower CD4/CD8 ratio.

CONCLUSION

In PWH starting ART, detection of CMV and EBV DNA in PBMC was associated with development of non-AIDS events. Clinical trials will be needed to understand causal mechanisms and ways to interrupt them.

Rapid Sequencing of Complete env Genes from Primary HIV-1 Samples

The ability to study rapidly evolving viral populations has been constrained by the read length of next-generation sequencing approaches and the sampling depth of single-genome amplification methods. Here, we develop and characterize a method using Pacific Biosciences' Single Molecule, Real-Time (SMRT®) sequencing technology to sequence multiple, intact full-length human immunodeficiency virus-1 env genes amplified from viral RNA populations circulating in blood, and provide computational tools for analyzing and visualizing these data.

Characterizing the multiplicity of HIV founder variants during sexual transmission among MSM

Transmission of multiple founder variants has been associated with faster HIV disease progression. Many studies have attempted to determine the number of founder variants, mainly by analysis of sequence diversity and/or tree topology from acutely HIV-infected individuals. We hypothesized that adding sequence data collected from source partners might improve resolution and characterization of transmission events. Blood plasma samples were collected from both the source and recipient in thirty epidemiologically- and phylogenetically linked transmission pairs. All were men who have sex with men, sampled on average 70 days (range 11–170) after the recipient’s estimated date of infection. Next generation sequencing (454 FLX, Roche) of HIV-1 env (C2-V3) was performed for all samples. Inspection of sequence alignments, highlighter plots, phylogenetic tree topologies and sequence diversity were used to determine the multiplicity of founder viruses with and without the inclusion of source data. Using only recipient sequence data, we were able to resolve multiplicity in twenty-six of the thirty transmission pairs (87 percent). Among them, five presented with a high viral diversity at baseline (>0.10 subst/site), consistent with multiple founders. By incorporating sequence data collected from the source partner, we were able to characterize all thirty transmission pairs. Overall, sixteen transmission events (53.3 percent) involved multiple founders. Results obtained by combining sequence data from recipient and source were congruent for nineteen of the twenty-six (73 percent) cases where conclusions were made using only recipient sequence data. The multiplicity of founders was associated with significantly higher HIV RNA levels (P = 0.04). To further evaluate the transmission bottleneck, we focused on single founder transmissions (fourteen of the thirty), and identified four recipients (28.6 percent) that had founder variants that were inferred to arise from minority viral populations in the source. These source clades ranged from 1.0 to 5.4 percent of the sampled population. Incorporating sequence data from the source increased of the ability to determine the multiplicity of founder variants, reduced misclassification, and allowed us to infer the transmission of minority variants.

Clade-Specific Quantitative Analysis of Photosynthetic Gene Expression in Prochlorococcus

Newly designed primers targeting rbcL (CO2 fixation), psbA (photosystem II) and rnpB (reference) genes were used in qRT-PCR assays to assess the photosynthetic capability of natural communities of Prochlorococcus, the most abundant photosynthetic organism on Earth and a major contributor to primary production in oligotrophic oceans. After optimizing sample collection methodology, we analyzed a total of 62 stations from the Malaspina 2010 circumnavigation (including Atlantic, Pacific and Indian Oceans) at three different depths. Sequence and quantitative analyses of the corresponding amplicons showed the presence of high-light (HL) and low-light (LL) Prochlorococcus clades in essentially all 182 samples, with a largely uniform stratification of LL and HL sequences. Synechococcus cross-amplifications were detected by the taxon-specific melting temperatures of the amplicons. Laboratory exposure of Prochlorococcus MED4 (HL) and MIT9313 (LL) strains to organic pollutants (PAHs and organochlorine compounds) showed a decrease of rbcL transcript abundances, and of the rbcL to psbA ratios for both strains. We propose this technique as a convenient assay to evaluate effects of environmental stressors, including pollution, on the oceanic Prochlorococcus photosynthetic function.

Perfluoroalkylated substances in the global tropical and subtropical surface oceans

In this study, perfluoroalkylated substances (PFASs) were analyzed in 92 surface seawater samples taken during the Malaspina 2010 expedition which covered all the tropical and subtropical Atlantic, Pacific and Indian oceans. Nine ionic PFASs including C6-C10 perfluoroalkyl carboxylic acids (PFCAs), C4 and C6-C8 perfluoroalkyl sulfonic acids (PFSAs) and two neutral precursors perfluoroalkyl sulfonamides (PFASAs), were identified and quantified. The Atlantic Ocean presented the broader range in concentrations of total PFASs (131-10900 pg/L, median 645 pg/L, n = 45) compared to the other oceanic basins, probably due to a better spatial coverage. Total concentrations in the Pacific ranged from 344 to 2500 pg/L (median = 527 pg/L, n = 27) and in the Indian Ocean from 176 to 1976 pg/L (median = 329, n = 18). Perfluorooctanesulfonic acid (PFOS) was the most abundant compound, accounting for 33% of the total PFASs globally, followed by perfluorodecanoic acid (PFDA, 22%) and perfluorohexanoic acid (PFHxA, 12%), being the rest of the individual congeners under 10% of total PFASs, even for perfluorooctane carboxylic acid (PFOA, 6%). PFASAs accounted for less than 1% of the total PFASs concentration. This study reports the ubiquitous occurrence of PFCAs, PFSAs, and PFASAs in the global ocean, being the first attempt, to our knowledge, to show a comprehensive assessment in surface water samples collected in a single oceanic expedition covering tropical and subtropical oceans. The potential factors affecting their distribution patterns were assessed including the distance to coastal regions, oceanic subtropical gyres, currents and biogeochemical processes. Field evidence of biogeochemical controls on the occurrence of PFASs was tentatively assessed considering environmental variables (solar radiation, temperature, chlorophyll a concentrations among others), and these showed significant correlations with some PFASs, but explaining small to moderate percentages of variability. This suggests that a number of physical and biogeochemical processes collectively drive the oceanic occurrence and fate of PFASs in a complex manner.

Incidence and prevalence of intrasubtype HIV-1 dual infection in at-risk men in the United States

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1) dual infection (DI) has been associated with decreased CD4 T-cell counts and increased viral loads; however, the frequency of intrasubtype DI is poorly understood. We used ultradeep sequencing (UDS) to estimate the frequency of DI in a primary infection cohort of predominantly men who have sex with men (MSM).

METHODS

 HIV-1 genomes from longitudinal blood samples of recently infected, therapy-naive participants were interrogated with UDS. DI was confirmed when maximum sequence divergence was excessive and supported by phylogenetic analysis. Coinfection was defined as DI at baseline; superinfection was monoinfection at baseline and DI at a later time point.

RESULTS

 Of 118 participants, 7 were coinfected and 10 acquired superinfection. Superinfection incidence rate was 4.96 per 100 person-years (95% confidence interval [CI], 2.67-9.22); 6 occurred in the first year and 4 in the second. Overall cumulative prevalence of intrasubtype B DI was 14.4% (95% CI, 8.6%-22.1%). Primary HIV-1 incidence was 4.37 per 100 person-years (95% CI, 3.56-5.36).

CONCLUSIONS

 Intrasubtype DI was frequent and comparable to primary infection rates among MSM in San Diego; however, superinfection rates declined over time. DI is likely an important component of the HIV epidemic dynamics, and development of stronger immune responses to the initial infection may protect from superinfection.

Using ultradeep pyrosequencing to study HIV-1 coreceptor usage in primary and dual infection

HIV-1 dual infection (DI) and CXCR4 (X4) coreceptor usage are associated with accelerated disease progression but frequency and dynamics of coreceptor usage during DI is unknown. Ultradeep sequencing was used to interrogate for DI and infer coreceptor usage in longitudinal blood samples of 102 subjects. At baseline, X4 usage was high (23 subjects harbored X4 variants) and was not associated with infection duration or DI. Coreceptor usage changed over time in 12 of 47 participants, and X4 usage emerged in 4 of 41 monoinfections vs 2 of 5 superinfections (P = .12), suggesting a weak statistical trend toward occurrence of superinfection and acquiring X4 usage.

Occurrence of aerosol-bound fullerenes in the Mediterranean Sea atmosphere

This work describes the assessment of a selection of fullerenes including C(60) and C(70) fullerene, N-methylfulleropyrrolidine, C(60) pyrrolidine tris-acid ethyl ester, [6,6]-Phenyl-C(61) butyric acid butyl ester and [6,6]-Thienyl C(61) butyric acid methyl ester, in airborne particulate from the Mediterranean Sea collected during two sampling campaigns from Barcelona to Istanbul and Alexandria, respectively. The analysis of the samples was carried out using a new method based on liquid chromatography coupled to mass spectrometry (LC-MS) presenting sensitivities between 5.4 and 20.9 pg/m(3). A total number of 43 samples covering the different basins of Mediterranean Sea were analyzed. Fullerenes were detected in all analyzed samples and quantifiable concentrations were found in 28 of the analyzed samples. The median of C(60) and C(70) fullerenes aerosol phase concentrations were 0.06 ng/m(3) and 0.48 ng/m(3) respectively for the Mediterranean Sea atmosphere. C(70) fullerene was the most frequently detected compound and also it was found in the higher concentrations for most samples, reaching 233.8 ng/m(3). The modeled back-trajectories disclose that those samples with higher concentrations of fullerenes were related to air masses which had been circulating over regions with an intense industrial activity, but the variability of the C(70)/C(60) ratio suggests multiple different sources. These results are related to the incidental emissions from urban and industrial development, underpinning the need of studying the possible risks associated to carbon nanoparticles in the environment and the need of evaluating the possible consequences of their ubiquitous occurrence.

Ubiquitous net volatilization of polycyclic aromatic hydrocarbons from soils and parameters influencing their soil-air partitioning

Soils are a major reservoir of organic pollutants, and soil-air partitioning and exchange are key processes controlling the regional fate of pollutants. Here, we report and discuss the soil concentrations of polycyclic aromatic hydrocarbons (PAHs), their soil fugacities, the soil-air partition coefficients (K(SA)) and soil-air gradients for rural and semirural soils, in background areas of N-NE Spain and N-NW England. Different sampling campaigns were carried out to assess seasonal variability and differences between sampling sites. K(SA) values were dependent on soil temperature and soil organic quantity and type. Soil fugacities of phenanthrene and its alkyl homologues were 1-2 orders of magnitude higher than their ambient air fugacities for all sampling sites and periods. The soil to air fugacity ratio was correlated with soil temperature and soil redox potential. Similar trends for other PAHs were found but with lower fugacity ratios. The ubiquitous source of PAHs from background soils to the atmosphere found in all temperate regions in different seasons provides an indirect evidence of potential in situ generation of two to four ring PAHs and their alkyl homologues in the surface soil. We discuss this hypothetical biogenic source and other potential processes that could drive the high soil to air fugacity ratios of some PAHs.

Factors influencing the soil-air partitioning and the strength of soils as a secondary source of polychlorinated biphenyls to the atmosphere

Soils are a major reservoir of persistent organic pollutants, and soil-air partitioning and exchange are key processes controlling the atmospheric concentrations and regional fate of pollutants. Here, we report and discuss the concentrations of polychlorinated biphenyls (PCBs) in soils, their measured fugacities in soil, the soil-air partition coefficients (K(SA)) and soil-air fugacity gradients in rural background areas of N-NE Spain and N-NW England. Four sampling campaigns were carried out to assess seasonal and daily variability and differences between sampling sites. K(SA) values were significantly dependent on soil temperature and soil organic matter quantity, and to a minor extent organic matter type. All the PCB congeners in the soil are close to equilibrium with the atmosphere at rural Ebro sites, but soil fugacities tend to be higher than ambient air fugacities in early and late summer, consistent with the influence of temperature on soil-air partitioning. Therefore, during warm periods, soils increment their strength as secondary sources to the atmosphere. The mixture of PCBs found in the atmosphere is clearly strongly influenced by the mixture of PCBs which escape from soil, with significant correlations between them (R(2) ranging between 0.35 and 0.74 and p-level <0.001 for the Ebro sampling sites). Conversely, the close-to-equilibrium to net sink status of rural UK sites, suggest a close coupling of air and soil concentrations, but it is not possible to elucidate the importance of these soils as secondary sources yet, and presumably there are still significant primary sources to the regional/global environment.

Stable interference of EWS-FLI1 in an Ewing sarcoma cell line impairs IGF-1/IGF-1R signalling and reveals TOPK as a new target

BACKGROUND

Ewing sarcoma is a paradigm of solid tumour -bearing chromosomal translocations resulting in fusion proteins that act as deregulated transcription factors. Ewing sarcoma translocations fuse the EWS gene with an ETS transcription factor, mainly FLI1. Most of the EWS-FLI1 target genes still remain unknown and many have been identified in heterologous model systems.

METHODS

We have developed a stable RNA interference model knocking down EWS-FLI1 in the Ewing sarcoma cell line TC71. Gene expression analyses were performed to study the effect of RNA interference on the genetic signature of EWS-FLI1 and to identify genes that could contribute to tumourigenesis.

RESULTS

EWS-FLI1 inhibition induced apoptosis, reduced cell migratory and tumourigenic capacities, and caused reduction in tumour growth. IGF-1 was downregulated and the IGF-1/IGF-1R signalling pathway was impaired. PBK/TOPK (T-LAK cell-originated protein kinase) expression was decreased because of EWS-FLI1 inhibition. We showed that TOPK is a new target gene of EWS-FLI1. TOPK inhibition prompted a decrease in the proliferation rate and a dramatic change in the cell's ability to grow in coalescence.

CONCLUSION

This is the first report of TOPK activity in Ewing sarcoma and suggests a significant role of this MAPKK-like protein kinase in the Ewing sarcoma biology.

[Restructuring and reorganization project in the public health area]

The objective of this project is to produce substantial change as regards the reorganization, reconstruction and normalization of the hospital data to extra hospital data recording system from the Ministry of Health in the Province of Córdoba (Argentina). In order to incorporate socio-demographic factors in the various data forms so asa to produce efficiency upon the politic implemented. To achieve such aim, colwork on the different levels of execution, training the health team with respect to the identification of the population problems, and attempting to change of a demographic basis the current sanitary policies into policies of populations.

Endovascular repair of an ascending aorta-to-left common femoral artery graft with aneurysmal degeneration

PURPOSE

To report the use of endovascular grafting to repair degenerative aneurysmal changes in an extra-anatomic bypass graft.

METHODS

A 14-year-old extra-anatomic ascending aorta-to-left common femoral bypass graft ("ventral aorta") had undergone aneurysmal degeneration, producing symptoms of progressive claudication and local abdominal swelling. The aneurysmal graft dilatation began within the thoracic cavity and extended through the entire extraperitoneal abdominal segment. The option for minimally invasive repair using a customized stent-graft device was offered to the patient as an alternative to standard reoperation.

RESULTS

An 8-mm x 42-cm endovascular graft was constructed by polytetrafluoroethylene with 30-mm Palmaz stents sutured to each end. With balloon occlusion of antegrade and retrograde blood flow, the stent-graft was delivered retrograde through an incision in the distal end of the existing bypass graft. The device was successfully positioned and deployed with complete exclusion of the aneurysm. No complications occurred, and the patient's symptoms abated. Follow-up arteriography at 1 months showed a pseudoaneurysm at the distal graft incision site; surgical repair was necessary. At 6 months, angiography demonstrated continued patency of the extra-anatomic bypass graft.

CONCLUSIONS

Intraluminal aneurysm exclusion techniques in degenerated extra-anatomic bypass grafts may evolve into a viable therapeutic alternative to complex reoperative surgery.

[Laparoscopic cholecystectomy. 1203 cases with ultraselective cholangiography]

We present our experience at the University of Chile Hospital with 1203 cases of laparoscopic cholecistectomy between April 1991 and July 1993. In only 36 patients ultraselective cholangiography was performed. In 88 cases an endoscopic cholangiography was performed prior to surgery because of suspicion of choledocolithiasis. In 31 of them choledocolithiasis was demonstrated, and was successfully treated by papilotomy in 30 of them. In 5.8% of cases coversion to open surgery was necessary: 1.4% in chronic cholecystitis, 13% in acute cholecystitis and 39% in cases with fibrosis and esclerosis of gallbladder with or without biliary digestive fistula. The intraoperative cholangiography has been advocated as a manner to prevent the common duct injury. In spite of the small number of cases operated on with cholangiography, we haven't seen serious injuries of biliary tract; a carefully disection, as far away as possible of the common duct, is the best way to prevent iatrogenic lesions. Postoperative morbidity was present in 15 cases, 8 of them required a new operation. Two patients died.

Long-term ambulatory treatment of metastatic colorectal adenocarcinoma by continuous intravenous infusion of 5-fluorouracil

To delineate the efficacy of continuous intravenous 5-fluorouracil (5-FU) infusion therapy for advanced colorectal adenocarcinoma, a study of 36 patients with measurable metastatic disease was conducted. Patients received a daily intravenous infusion of 300 mg/m2 5-FU over a 24-h period utilizing portable infusion devices and central venous catheters. In a population characterized by substantial pretreatment exposure to radiotherapy, chemotherapy, and other indicators of poor prognosis, 13/36 (36%) patients achieved an objective response. An additional 10/36 (28%) patients manifested stable disease (no change) and experienced survival comparable to that of patients with objective response. Toxicity was minimal; patients were able to continue 5-FU infusions 95% of the total time on protocol. There were no adverse hematologic effects or catheter complications. Because previously untreated patients benefited more frequently (positive response, 50%), continuous intravenous infusion should be evaluated further as a primary modality option when 5-fluorouracil antitumor chemotherapy is contemplated.

Drug concentration errors related to sampling from Silastic catheters

To the Editor:

Constant infusion of some antitumor agents appears to improve their efficacy and/or diminish adverse effects associated with their administration. Silastic catheters placed for long-term central access facilitate this type of therapy. Also, they provide a means to obtain blood with minimal trauma for the patient. During treatment it is sometimes useful to withdraw samples for assay of drug blood levels. When doing so, we became concerned about unusually high 5-fluorouracil (5-FU) values in several patients, causing us to measure drug concentration in samples taken simultaneously from the catheter and a peripheral vein. Catheter samples showed seven to 80 times greater concentration of 5-FU. In one individual who had been off infusion for three days, a small 5-FU concentration persisted in the catheter sample whereas the peripheral vein value was zero as expected.

Subsequently, we performed an in vitro study. A Broviac catheter (volume, 0.6 mL) was perfused for five days at 2.0 mL per hour with a solution containing 500 mg 5-FU made up to 60 mL with 0.9% saline. The catheter then was flushed with 30-mL water to remove all fluid containing 5-FU. Ensuing sampling and flushing was done in accordance with Table 1. The last milliliter of flush solution was analyzed in each instance by high-pressure liquid chromatography technology.

Since all of the 5-FU infusion solution had been removed, the presence of drug in the water wash indicates that 5-FU was passing into the catheter lumen from the silastic wall.

We believe it is important to recognize that other drugs may act in the same way. The use of silastic catheters for both infusion and sampling may lead to an overestimation of drug concentration even though sufficient blood is withdrawn before taking the definitive sample.

Please see the PDF for Table.