Cross sectional survey of Varicella-Zoster virus and measles seropositivity in people living with HIV in a Parisian suburb and a review of current immunization guidelines.

According to evidence-based guidelines, vaccines against measles and varicella are generally recommended to susceptible HIV-positive patients, as long as they are not severely immunocompromised. However, routine screening to determine serologic status is not recommended. We conducted a seroprevalence study of anti-measles and anti-Varicella-Zoster virus (VZV) antibodies in adults living with HIV (PLWHA) consulting at Avicenne University Hospital in a Parisian suburb. Sera were collected in years 2018-2020 and tested by commercial immunoassays in 268 patients. Most of the patients were born in Sub-Saharan Africa (55 %) and only 23 % in Europe. Measles and varicella seropositivity were present respectively in 91.4 % and 96.2 % of patients. One patient in ten was seronegative to at least one of tested diseases. In the univariate analysis, only younger age (p = 0.027) was associated with a higher risk of measles seronegativity, while shorter time since arrival in France (p < 0.001) and shorter time since HIV discovery (p = 0.007) were associated with a higher risk of VZV seronegativity. In multivariate analysis no association was found. This study highlights the absence of specific risk factors for VZV and measles seronegativity in PLWHA and supports the importance of routine screening, in order to increase immunization rates and reduce risk of complications.

Microbiological epidemiology and antibiotic susceptibility of infected meshes after prosthetic abdominal wall repair.

INTRODUCTION: Infectious complications of parietal mesh after prosthetic abdominal wall repair are rare. Their management is complex. Furthermore, the emergence of bacterial resistance, the presence of a foreign material, the need to continue an extended antibiotic therapy, and the choice of an appropriate treatment are crucial. The objective of this study is to access the microbiological epidemiology of infected parietal meshes in order to optimize the empirical antibiotic therapy. METHODS: Between January 2016 and December 2021, a monocentric and retrospective study was performed in patients hospitalized for infected parietal meshes at Avicenne hospital, in Paris area. Clinical and microbiological data such as antibiotic susceptibility were collected. RESULTS: Twenty-six patients with infected parietal meshes have been hospitalized during this period. Meshes were in preaponevrotic positions (n=10; 38%), retromuscular (n=6; 23%) and intraperitoneal (n=10; 38%). Among the 22 (84.6%) documented cases of infections, 17 (77.3%) were polymicrobial. A total of 54 bacteria were isolated, 48 of which had an antibiogram available. The most frequently isolated bacteria were: Enterobacterales (n=19), Enterococcus spp. (n=11) and Staphylococcus aureus (n=6), whereas anaerobes were poorly isolated (n=3). Concerning these isolated bacteria, amoxicillin-clavulanic acid, metronidazole-associated cefotaxime, piperacillin-tazobactam and meropenem were susceptible in 45.5%, 68.2%, 63.6%, 77.2%, of cases, respectively. CONCLUSION: This work highlights that infections of abdominal parietal meshes may be polymicrobial and the association amoxicillin-clavulanic acid cannot be used as a probabilist antibiotic therapy because of the high resistance rate in isolated bacteria. The association piperacillin-tazobactam appears to be a more adapted empirical treatment to preserve carbapenems, a broad-spectrum antibiotic class.

Intra-abdominal abscesses: Microbiological epidemiology and empirical antibiotherapy.

PURPOSE: Data on the microbiological epidemiology of Intra-Abdominal Abscesses (IAAs) are very scarce. We aimed to study the microbiological epidemiology of these infections in order to optimize empirical antibiotic therapy. PATIENTS AND METHODS: Between January 2015 and December 2020, we retrospectively analyzed all IAAs files in our hospital. Clinical and microbiological data such as antibiotic susceptibilities were collected. RESULTS: We studied 243 IAA cases. All in all, 139 (57.2%) IAAs were healthcare-associated and 201 (82.7%) were drained. The highest risk situations for IAAs were appendicitis (n = 69) and diverticulitis (n = 37). Out of the 163 microbiologically documented infections, 136 (81.9%) were polymicrobial. Enterobacterales (n = 192, 36.1%), Enterococcus sp. (n = 84, 17.6%) and anaerobes (n = 66, 16.1%) were the most frequently identified bacteria. Gram-negative bacteria were susceptible to amoxicillin-acid clavulanic, piperacillin-tazobactam, cefotaxime, meropenem in 55.2%, 84.9%, 77.6% and 99.5% of cases, respectively. Concerning Gram-positive bacteria, the susceptibility rate was 81.8% for amoxicillin-clavulanic acid, piperacillin-tazobactam and meropenem, and decreased to 63.4% for cefotaxime. CONCLUSION: This study highlights the polymicrobial profile of IAAs and their low susceptibility to amoxicillin and clavulanic acid. The piperacillin-tazobactam association remained the most appropriate empirical antibiotic therapy.

Nonuniversal effects in mixing correlated-growth processes with randomness: interplay between bulk morphology and surface roughening.

To construct continuum stochastic growth equations for competitive nonequilibrium surface-growth processes of the type RD+X that mixes random deposition (RD) with a correlated-growth process X, we use a simplex decomposition of the height field. A distinction between growth processes X that do and do not create voids in the bulk leads to the definition of the effective probability p(eff) of the process X that is a measurable property of the bulk morphology and depends on the activation probability p of X in the competitive process RD+X. The bulk morphology is reflected in the surface roughening via nonuniversal prefactors in the universal scaling of the surface width that scales in p(eff). The equation and the resulting scaling are derived for X in either a Kardar-Parisi-Zhang or Edwards-Wilkinson universality class in (1+1) dimensions and are illustrated by an example of X being a ballistic deposition. We obtain full data collapse on its corresponding universal scaling function for all p∈(0;1]. We outline the generalizations to (1+n) dimensions and to many-component competitive growth processes.

Comment on "Dynamic properties in a family of competitive growing models".

The article [Phys. Rev. E 73, 031111 (2006)] by Horowitz and Albano reports on simulations of competitive surface-growth models RD+X that combine random deposition (RD) with another deposition X that occurs with probability p . The claim is made that at saturation the surface width w(p) obeys a power-law scaling w(p) proportional, variant1/pdelta, where delta is only either delta=1/2 or delta=1 , which is illustrated by the models where X is ballistic deposition and where X is RD with surface relaxation. Another claim is that in the limit p-->0+, for any lattice size L, the time evolution of w(t) generally obeys the scaling w(p,t) proportional, variant(Lalpha/pdelta)F(p2deltat/Lz), where F is Family-Vicsek universal scaling function. We show that these claims are incorrect.

Universal scaling in mixing correlated growth with randomness.

We study two-component growth that mixes random deposition (RD) with a correlated growth process that occurs with probability p. We find that these composite systems are in the universality class of the correlated growth process. For RD blends with either Edwards-Wilkinson or Kardar-Parisi-Zhang processes, we identify a nonuniversal exponent in the universal scaling in p.

Roughening of the interfaces in (1+1) -dimensional two-component surface growth with an admixture of random deposition.

We simulate competitive two-component growth on a one-dimensional substrate of L sites. One component is a Poisson-type deposition that generates Kardar-Parisi-Zhang (KPZ) correlations. The other is random deposition (RD). We derive the universal scaling function of the interface width for this model and show that the RD admixture acts as a dilatation mechanism to the fundamental time and height scales, but leaves the KPZ correlations intact. This observation is generalized to other growth models. It is shown that the flat-substrate initial condition is responsible for the existence of an early nonscaling phase in the interface evolution. The length of this initial phase is a nonuniversal parameter, but its presence is universal. We introduce a method to measure the length of this initial nonscaling phase. In application to parallel and distributed computations, the important consequence of the derived scaling is the existence of the upper bound for the desynchronization in a conservative update algorithm for parallel discrete-event simulations. It is shown that such algorithms are generally scalable in a ring communication topology.

Update statistics in conservative parallel-discrete-event simulations of asynchronous systems.

We model the performance of an ideal closed chain of L processing elements that work in parallel in an asynchronous manner. Their state updates follow a generic conservative algorithm. The conservative update rule determines the growth of a virtual time surface. The physics of this growth is reflected in the utilization (the fraction of working processors) and in the interface width. We show that it is possible to make an explicit connection between the utilization and the microscopic structure of the virtual time interface. We exploit this connection to derive the theoretical probability distribution of updates in the system within an approximate model. It follows that the theoretical lower bound for the computational speedup is s=(L+1)/4 for L> or =4. Our approach uses simple statistics to count distinct surface-configuration classes consistent with the model growth rule. It enables one to compute analytically microscopic properties of an interface, which are unavailable by continuum methods.

Algorithmic scalability in globally constrained conservative parallel discrete event simulations of asynchronous systems.

We consider parallel simulations for asynchronous systems employing L processing elements that are arranged on a ring. Processors communicate only among the nearest neighbors and advance their local simulated time only if it is guaranteed that this does not violate causality. In simulations with no constraints, in the infinite L limit the utilization scales [Korniss et al., Phys. Rev. Lett. 84, 1351 (2000)]; but, the width of the virtual time horizon diverges (i.e., the measurement phase of the algorithm does not scale). In this work, we introduce a moving Delta-window global constraint, which modifies the algorithm so that the measurement phase scales as well. We present results of systematic studies in which the system size (i.e., L and the volume load per processor) as well as the constraint are varied. The Delta constraint eliminates the extreme fluctuations in the virtual time horizon, provides a bound on its width, and controls the average progress rate. The width of the Delta window can serve as a tuning parameter that, for a given volume load per processor, could be adjusted to optimize the utilization, so as to maximize the efficiency. This result may find numerous applications in modeling the evolution of general spatially extended short-range interacting systems with asynchronous dynamics, including dynamic Monte Carlo studies.

Canned cod liver as a source of n-3 polyunsaturated fatty acids, with a reference to contamination.

Lipid composition (HPLC), fatty acid composition (GC/MS), lipid oxidation (peroxide value, anisidine value), UV-VIS and fluorescence spectra (Ex 365 nm), and susceptibility of lipids to oxidation (photooxidation test) as well as heavy metal, PCB, and DDT contents were determined in canned, raw, and thermally treated cod liver (separately in the released oil and in the solids). Canned products of three manufacturers were examined. Mean contents of n-3 polyunsaturated fatty acids (n-3 PUFAs) in the oil and solids were 31.91 +/- 1.83 and 16.59 +/- 7.48 g/100 g, respectively, the respective contents of docosahexaenoic acid (DHA) being 17.88 +/- 1.69 and 8.79 +/- 3.67 g/100 g. Lipid resistance to oxidation was found to decrease after thermal treatment of livers. However, the lipid oxidation level in canned liver stored for 3-8 months was not high and averaged, for the entire can content, 0.47 +/- 0.4 Meq O, the oil being more susceptible to oxidation that the solids. It is concluded that canned cod liver is a very good source of n-3 PUFA, particularly with respect to DHA. Heavy metal, DDT, and PCB contamination and the presence of lipid oxidation products in the canned products tested remain at a level producing no perceivable health hazard and could in no way interfere with consumption of recommended amounts of n-3 PUFAs.

Changes in lipids during the storage of krill (Euphausia superba Dana) at 3 degrees C.

Lipid content and composition (classes), susceptibility to UV-catalysed oxidation and carotenoid content were determined in Antarctic krill (Euphausia superba Dana) stored for 72 h at 3 degrees C. Phospholipids making up 80% of krill lipids were observed to undergo the most drastic changes during storage. After 72 h of storage, their content dropped by about 20%; the largest drop was recorded in phosphatidylcholine, its content being reduced by almost half. The amount of free fatty acids increased to about 6% of lipids. No degradation was observed in triacylglycerols, diacylglycerols, and wax esters. Monoglycerides did not appear. The UV-catalysed lipid oxidation rate decreased with deteriorating freshness of krill, as evidenced by a slower oxidation reaction, much lower oxidation maximum attained by lipids from spoiled krill, slower carotenoid decomposition, slower coloration of lipids and a slower absorbance increase at 320 nm. As no significant differences were found between iodine numbers and the carotenoid content of the samples tested, differences in the oxidation rate can be explained by hyperoxide decomposition brought about by products of phosphatidylcholine break-down.

Lipid composition of fresh and frozen-stored krill.

Lipid classes in seven krill (Euphausia superba D.) samples, fresh and after various periods of storage at 251 K were compared. Fresh krill lipid composition differed from that determined in frozen samples, depending on storage duration, season of harvest, and developmental stage (as determined on a few samples only). Phospholipids proved most susceptible to changes, as opposed to triglycerides, which were most resistant; diglycerides and cholesterol esters were also destroyed. The freezing process per se affected the lipid composition only slightly; however, after 30 days storage the amount of free fatty acids almost doubled. After 6 months storage at 251 K, 70% of phospholipids were decomposed and the amount of free fatty acids increased by a factor of 6 to 20. Monoglycerides, absent from fresh krill, appeared after several months of frozen storage. Juvenile krill were more susceptible to lipolytic changes. Females bearing mature eggs contained stable phospholipids; it was only triglycerides that were hydrolysed. It seems probable that discrepancies encountered in the literature data on krill lipid composition are the result of frozen krill being analysed.

The influence of trimethylamine on the concentration/odour intensity relations in hexanal.

Hexanal and trimethylamine are products formed in the process of fish deterioration and it is believed that both these substances contribute somehow to the typical off-flavour developing in the course of this process. In aqueous hexanal solutions and in hexanal solutions with added trimethylamine the intensity differences in the odour of hexanal and the difference thresholds for hexanal solutions were determined.

Some comments on the usefulness of 2-thiobarbituric acid (TBA) test for the evaluation of rancidity in frozen fish.

Rancidity of frozen fish (Baltic cod and herring, mackerel, horse mackerel and hake) was determined by means of TBA value, organoleptical scoring and peroxide value. The correlation between the rancid odour sensory assessment and TBA test results proved insignificant (r = 0.53). Model experiment was undertaken in which promine D with addition of papain was incubated at 50 degrees C over 44 h. It was shown that as accumulation of protein hydrolysis products proceeded the increase of TBA value has taken place without development of rancid odour and with peroxide content below sensibility of sulphocyanide method. With regard to fish, therefore, it seems that the TBA test applied by means of techniques in which the reaction with TBA proceeds in the presence of interfering substances should be treated as a "freshness test" rather than a strictly rancidity one.

Nonenzymic browning. XI. Effect of free amino groups on browning reactions in lipid-protein mixtures.

The course of browning was more rapid in mixtures of polyunsaturated fatty acid esters with casein that in those of the same lipids with formaldehyde-treated casein or with an inert inorganic substrate (barium sulphate or sodium sulphate). On the contrary, the content of oxidation products (peroxides and aldehydes) was much higher in lipids mixed with formaldehydetreated casein or with inorganic substrates. The results obtained with albumin were similar. The ratio of red to yellow pigments was higher in mixtures with non-treated casein than in the other two investigated reaction mistures. Brown pigments contained only low per centages of nitrogen.