What do the changing patterns of comorbidity burden in people living with HIV mean for long-term management? Perspectives from European HIV cohorts.

Undoubtedly, comorbidities complicate long-term HIV management and have significant cost implications for healthcare systems. A better understanding of these comorbidities and underlying causes would allow for a more considered and proactive approach to the long-term management of HIV. This review examines cross-sectional analyses of six European cohort studies (Athens Multicenter AIDS Cohort Study, Aquitaine Cohort, EuroSIDA Cohort study, French claims EGB, German InGef Cohort and the Italian Cohort of Individuals, Naïve for Antiretrovirals), which included individuals with HIV followed over a certain period of time. Based on these cohorts, we examined how comorbidities have changed over time; how they compromise HIV management; and how much of a financial burden they impart. These data also provided a framework to explore the major issues of ageing and HIV and the practical implications of managing such issues in real-life practice.

Reference curves for CD4 T-cell count response to combination antiretroviral therapy in HIV-1-infected treatment-naïve patients.

OBJECTIVES: The aim of this work was to provide a reference for the CD4 T-cell count response in the early months after the initiation of combination antiretroviral therapy (cART) in HIV-1-infected patients. METHODS: All patients in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) cohort who were aged ≥ 18 years and started cART for the first time between 1 January 2005 and 1 January 2010 and who had at least one available measurement of CD4 count and a viral load ≤ 50 HIV-1 RNA copies/mL at 6 months (± 3 months) after cART initiation were included in the study. Unadjusted and adjusted references curves and predictions were obtained using quantile regressions. RESULTS: A total of 28 992 patients were included in the study. The median CD4 T-cell count at treatment initiation was 249 [interquartile range (IQR) 150, 336] cells/µL. The median observed CD4 counts at 6, 9 and 12 months were 382 (IQR 256, 515), 402 (IQR 274, 543) and 420 (IQR 293, 565) cells/µL. The two main factors explaining the variation of CD4 count at 6 months were AIDS stage and CD4 count at cART initiation. A CD4 count increase of ≥ 100 cells/mL is generally required in order that patients stay 'on track' (i.e. with a CD4 count at the same percentile as when they started), with slightly higher gains required for those starting with CD4 counts in the higher percentiles. Individual predictions adjusted for factors influencing CD4 count were more precise. CONCLUSIONS: Reference curves aid the evaluation of the immune response early after antiretroviral therapy initiation that leads to viral control.

The permanent deformation of the self-adjusting files when used in canals of extracted teeth.

AIM: To examine the permanent deformation of self-adjusting files (SAF) when used by endodontists with no previous experience with this system. METHODOLOGY: The canals of extracted human molars were initially prepared with glide path up to size 20 K-file. The operators were first instructed on the use of the SAF in simulated canals in plastic blocks then applied the SAF in natural root canals of extracted teeth. Every 4 min, each file was withdrawn from the canal and inspected for integrity. If intact, it was used in another canal for an additional 4 min and checked again. This was repeated until all 19 SAF files were deformed. The files were collected for inspection at ×50 magnification. All teeth were then examined radiographically for the presence of any metal fragments in the root canals. Permanent deformation was categorized according to the type and location occured. Three types were defined as follows: (i) detachment of one component of the file at one end while the component is retained (ii) detachment of a component at both ends and the component missing and (iii) permanent twisting of the component. Recordings were made and statistically analysed using McNemar's test. RESULTS: Mechanical failures on the 5-arch-side of SAF (odd side) were significantly more frequent in comparison with the even side (P = 0.039). Similarly, mechanical failures in arches on the odd side were also significantly more frequent compared with the even ones (P = 0.012) Longitudinal beams fractured significantly less often compared with arcs or struts (P < 0.001). In no case did complete file fracture occur, nor were metal fragments retained in the root canal. CONCLUSIONS: Deformation of SAF files occurred mainly as detachment of one of the arches or struts at connection points on the odd side of the file. In no case did its mechanical failure result in metal fragment retention in the root canal.

Central-line-associated bloodstream infections, multi-drug-resistant bacteraemias and infection control interventions: a 6-year time-series analysis in a tertiary care hospital in Greece.

BACKGROUND: Central-line-associated bloodstream infections (CLABSIs) are serious healthcare-associated infections with substantial morbidity and hospital costs. AIM: To investigate the association between the incidence of CLABSIs, the implementation of specific infection control measures, and the incidence of multi-drug-resistant (MDR) bacteraemias in a tertiary care hospital in Greece from 2013 to 2018. METHODS: Analysis was applied for the following indices, calculated monthly: CLABSI rate; use of hand hygiene disinfectants; isolation rate of patients with MDR bacteria; and incidence of bacteraemias [total Gram-negative carbapenem-resistant Acinetobacter baumanii, carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Klebsiella pneumoniae; and Gram-positive meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci]. FINDINGS: The total number of bacteraemias from carbapenem-resistant Gram-negative pathogens was significantly correlated with an increased CLABSI rate for all (total) hospital departments [incidence rate ratio (IRR) 1.17, 95% confidence interval (CI) 1.05-1.31, P=0.006] and the adult intensive care unit (ICU) (IRR 1.37, 95% CI 1.07-1.75, P=0.013). In the adult ICU, every increase in the incidence of each resistant Gram-negative pathogen was significantly correlated with a decreased CLABSI rate (carbapenem-resistant A. baumanii: IRR 0.59, 95% CI 0.39-0.90, P=0.015; carbapenem-resistant K. pneumoniae: IRR 0.48, 95% CI 0.25-0.94, P=0.031; carbapenem-resistant P. aeruginosa: IRR 0.54, 95% CI 0.33-0.89, P=0.015). The use of hand disinfectants was correlated with a decreased CLABSI rate 1-3 months before the application of this intervention for all (total) hospital departments (IRR 0.80, 95% CI 0.69-0.93, P=0.005), and for scrub disinfectants in the current month for the adult ICU (IRR 0.34, 95% CI 0.11-1.03, P=0.057). Isolation of patients with MDR pathogens was not associated with the incidence of CLABSIs. CONCLUSION: Hand hygiene was associated with a significant reduction in the incidence of CLABSIs at the study hospital. Time-series analysis is an important tool to evaluate infection control interventions.

Effectiveness of fissure sealants on initial caries lesions (ICDAS 1-3) of permanent molars: A 4-year follow-up.

AIM: The aim of the present prospective study was to evaluate the retention and effectiveness of two types of sealants (clear vs. opaque) on early pit and fissure occlusal non-cavitated ICDAS II #1-3, caries lesions of permanent posterior teeth of children. MATERIALS AND METHODS: Study Design: 6986 pit and fissure occlusal surfaces were randomly sealed with clear or opaque sealants out of which, 5828 sealants were placed on sound and 1158 on questionable surfaces, while 3508 were clear and 3478 opaque sealants. The mean age of the sample at initial sealant placement was 9.5 (±2.9) years and the follow-up time was 12-48 months. The median (IQR, range) follow-up time was 17.9 (8.7-28.6) months. Study inclusion and exclusion criteria applied to the combined database in order to select the study sample. Teethmate™ F-1 natural and opaque sealants (Kuraray, Hattersheim am Main, Germany) were applied following the standard procedure of preparation with moisture control kept by cotton rolls handled Dri-Angles" and a 30 seconds acid-etch with 37% ortho-phosphoric acid gel was used followed by 10 sec air-water spraying washing and polymerization for 20x2 sec. Sealants were applied on sound tooth surfaces (ICDAS #0) with no visible defects or on surfaces with early caries lesions (ICDAS #1-3), randomly and interchangeably on the upper or lower Jaw. Total retention was considered when all pits and fissures were completely sealed, while partial or complete loss was scored as one code, although was registered separately. STATISTICS: Separate analyses were performed for each type of failure (loss of sealant or restoration). Cumulative probabilities of failure over time after sealant placement, overall or by specific characteristics, were calculated using the Kaplan-Meier method. Association between these characteristics and the hazard of failure were investigated using appropriate Cox proportional hazard models. RESULTS: Sealed surfaces with ICDAS II # 1-3, showed 100% higher probability of having a restoration and 60% higher probability of sealant loss, with both differences being statistically significant (aHR=2.03, p=0.046), adjusted for age, sex, type of sealant and location of surface. Opaque sealants presented statistically significant (p 0.009) higher re-application rate, while fissures had 70% statistically significant (p<0.001) higher probability for resealing with time compared to pits, with gender not affecting sealant retention while the earlier a sealant was placed on children's teeth, the more probable it was to need resealing or restoration (p <0.012). CONCLUSIONS: The therapeutic use of sealants on occlusal surfaces of posterior permanent molars with early carious lesions (ICDAS II 1-3) is inferior compared to sound surfaces, showing higher sealant failures and restorations.

Secretion of nerve growth factor by central nervous system glioma cells in culture.

Bacteriophage immunoassays, radioimmunoassays, and biological assays have been used to measure levels of NGF in media conditioned by rat C-6 glioma cells in culture. By all three criteria, these cells secrete a macromolecule which is indistinguishable from mouse submandibular gland NGF.

Epidermal growth factor in the submandibular gland and serum of mice with muscular dystrophy: chemical properties in dilute gland extracts.

Epidermal growth factor (EGF) has been measured in extracts of submandibular glands from mice with hereditary muscular dystrophy. RIA results show that adult male and female dystrophic mice have significantly less submandibular gland EGF than do unafflicted controls. Despite the differences in gland content of the protein, serum levels of EGF are similar in both dystrophic and control animals. Furthermore, submandibular gland concentrations of amylase are normal in the dystrophic mice, indicating that not all proteins synthesized by the glands are affected. Gel filtration studied reveal that the elution properties of EGF in extracts of glands from dystrophic and control animals are indistinguishable. Unexpectedly, the chromatographic profiles indicate that most of the EGF in gland extracts elutes as a low molecular weight protein when the molecule is studied at low, biologically active concentrations; only a small portion of the protein is associated with a high molecular weight complex. Under the same experimental conditions, submandibular gland nerve growth factor maintains its association with other components in a high molecular weight form.

Effectiveness of teaching radiologic image interpretation in gross anatomy. A long-term follow-up.

This prospective study was designed to gauge the effectiveness of teaching radiologic interpretation during a gross anatomy course for first-year medical students by measuring short- and long-term ability to identify normal anatomic structures on radiologic diagnostic images. The evaluation required students to identify normal anatomic structures on radiographs, computed tomographs, ultrasonograms, and magnetic resonance images (MRIs). The assessments were made before (pre-test) and during (post-test) the experimental radiology portion of the gross anatomy course. The students were then retested 14 to 17 months later (long term). The pre-test correct response rate of 17% improved to 88% on the post-tests. After 14 to 17 months, the students had a 74% correct response rate on the same images and anatomic structures. This high level of long-term retention documents the effectiveness of integrating diagnostic radiologic imaging into normal gross anatomy instruction.

Gross anatomy instruction with diagnostic images.

A new module of instruction for diagnostic imaging with emphasis on cross-sectional anatomy was developed within the existing course of gross anatomy for freshmen medical students. Two lectures introduced radiation protection, radiology history, and the basic principles of computed tomography, magnetic resonance imaging, ultrasound, and radiograph image production. Six radiographic anatomy correlation sessions allowed student-teacher interaction while studying viewbox images in a "hands on" fashion. Relevant exhibits complemented cadaver dissection. Testing established that significant improvement occurred in the students' ability to identify anatomic structures on diagnostic images.

Nerve growth factor, not laminin, is the major neurite-promoting component in medium conditioned by mouse L929 fibroblast cells.

In this study the neurite-promoting activity present in conditioned medium (LCM) from mouse fibroblast L929 cells was examined. The biological and biochemical properties of nerve growth factor (NGF) synthesized by L929 cells and released into the LCM were studied. In addition it was established that the extracellular matrix protein laminin is synthesized by L929 cells and is also present in LCM. Although NGF is a well-recognized neurite-promoting factor, recent studies have suggested that laminin is also a neurite-promoting factor. In this paper the possibility that NGF and laminin were both responsible for the neurite-promoting activity of LCM was examined. It was determined that NGF, not laminin, is the major neurite-promoting component in LCM. This was established using pheochromocytoma (PC12) cells as a biological test system and also utilizing antibodies to both NGF and laminin. The possible functional significance of NGF synthesis by fibroblast cells is discussed.

Ethanol exposure reduces the density of the low-affinity nerve growth factor receptor (p75) on pheochromocytoma (PC12) cells.

Although ethanol is detrimental to the developing nervous system, the mechanism(s) by which ethanol produces neuronal damage is (are) not clear. One potential mechanism is ethanol-induced inhibition of neurotrophic support. This study utilized an in vitro model, pheochromocytoma PC12 cells, to examine the effect of ethanol on the nerve growth factor (NGF) receptor. NGF binding studies indicated that ethanol exposure (400 mg/dl for 4 days) reduced the density of the low-affinity (p75) NGF receptor on PC12 cells, but had no effect on the density of the high-affinity NGF receptor. The equilibrium dissociation constants (Kd) for both the low-affinity and high-affinity NGF receptors were unaffected by ethanol. Low-affinity NGF binding is mediated by the p75 component of the NGF receptor. Quantification of p75 by immunoprecipitation revealed that ethanol reduced the level of p75 in PC12 cells. However, Northern analysis indicated that the p75 mRNA was not reduced by ethanol exposure, raising the possibilities that ethanol inhibited translation of p75 or incorporation of the p75 protein into the plasma membrane. This work is consistent with the hypothesis that ethanol's detrimental effects may be produced in part by inhibition of neurotrophic support at the receptor level.

Rat astrocytes and Schwann cells in culture synthesize nerve growth factor-like neurite-promoting factors.

Neurite-promoting activity in feeding medium conditioned by rat astrocytes and Schwann cells in culture was examined. The conditioned medium (CM) from both types of glial cultures stimulated extensive neurite outgrowth from embryonic chick dorsal root ganglia (DRG) as well as pheochromocytoma (PC12) cells. Both the DRG and PC12 cells also produce neurite outgrowth in the presence of nerve growth factor (NGF). With the DRG, the neurite growth rates observed with the glial cell CM were identical to growth rates seen with NGF. Although anti-NGF antibody did not inhibit the neurite outgrowth produced by either of the glial CM, a nerve growth factor radioreceptor assay did detect an NGF-like molecule in both CM. Since the extensive neurite outgrowth stimulated by the glial CM was not mimicked by pure laminin alone, we conclude that the glial neurite promoting factors are distinct from laminin.

Transfection of C6 glioma cells with glia maturation factor upregulates brain-derived neurotrophic factor and nerve growth factor: trophic effects and protection against ethanol toxicity in cerebellar granule cells.

Glial cells play active roles in neuronal survival, as well as neuroprotection against toxic insult. Recent studies suggest that the brain protein glia maturation factor (GMF) is involved in intracellular signaling in glia. This study investigated whether or not GMF plays a role in the survival-promoting and neuroprotective functions of glia. C6 glioma cells were transfected in vitro with GMF utilizing an adenovirus vector. The transfected cells overexpressed GMF intracellularly, but did not secrete the protein. The conditioned medium (CM) was obtained from the GMF-transfected cells (CM-GMF) and tested on primary neuronal cultures, consisting of cerebellar granule cells (CGC). The CGC cultures were utilized because these cultures have a background level of cell death, and the survival-promoting, i.e. neurotrophic effect, of the CM could be tested. In addition, since CGC cultures are ethanol-sensitive (ethanol enhances neuronal death), the neuroprotective effect of the CM against ethanol-induced cell death was tested also. We demonstrated that the CM-GMF had an enhanced neurotrophic effect as well as an increased neuroprotective effect against ethanol-induced cell death compared to control CM obtained from untransfected C6 cells (CM-Mock) or CM obtained from cells transfected with an unrelated gene (CM-LacZ). Because neurotrophins have trophic and protective effects, we investigated whether GMF-transfection upregulated the expression of neurotrophins in C6 cells. RT-PCR verified that GMF-transfected C6 cells had increased mRNA levels for BDNF and NGF. Immunoblotting corroborated the RT-PCR results and indicated that CM-GMF contained greater concentrations of BDNF and NGF protein compared to CM-Mock and CM-LacZ. A soluble TrkB-IgG fusion protein, which selectively binds BDNF and prevents its binding to the neuronal TrkB receptor, eliminated the neurotrophic effect of CM-GMF; whereas anti-NGF antibody was ineffective in preventing this effect, suggesting that the neurotrophic effect was due to BDNF. On the other hand, both the TrkB-IgG fusion protein and anti-NGF reduced neuroprotection, suggesting that BDNF and NGF both contribute to the neuroprotective effect of CM-GMF. In conclusion, GMF upregulates the expression of BDNF and NGF in C6 cells, and these factors exert neurotrophic and neuroprotective functions on primary neurons.

Detection of a nerve growth factor receptor on fetal human Schwann cells in culture: absence of the receptor on fetal human astrocytes.

Cultures of human Schwann cells and astrocytes were established from fetal nerves and brains respectively. The human Schwann cells in culture expressed a nerve growth factor (NGF) receptor as determined by indirect immunofluorescence, autoradiography, and immunoprecipitation. In contrast, the human astrocytes in culture did not have an NGF receptor. Cultures of rat Schwann cells and astrocytes were also established for comparison, with similar results. The rat Schwann cells had an NGF receptor whereas the astrocytes did not. The functional significance of this NGF receptor on Schwann cells, as well as the lack of the receptor on astrocytes, is discussed.

Alcohol reduces the number of pheochromocytoma (PC12) cells in culture.

Pheochromocytoma (PC12) cells were used as an in vitro neuronal cell model to examine detrimental effects of alcohol on cell numbers. Alcohol exposure (100, 200, 400, and 800 mg/dl) reduced PC12 cell numbers in a dose-dependent manner. Cells that were treated with nerve growth factor (NGF) incurred less severe reductions in numbers compared with cells that were never treated with NGF. Because NGF stops proliferation of many of the PC12 cells and differentiates them into neuronal-like cells, these data suggest that differentiated, nonproliferating cells are less vulnerable to alcohol-induced reductions in cell numbers. In a subsequent experiment using only undifferentiated PC12 cells, alcohol reduced cell number of both proliferating and nonproliferating cultures; however, the reductions in proliferating cultures were more severe than in nonproliferating cultures. Two mechanisms may account for alcohol-induced reductions of PC12 cell numbers--inhibition of proliferation and killing of cells. PC12 cell cultures are a useful model system to examine mechanism(s) underlying alcohol's depletion of neuronal-like cells.

Effects of first antiretroviral regimen on lipid levels in HIV (+) individuals.

OBJECTIVE: To evaluate the long-term effects of different boosted protease inhibitors (bPIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs)-based antiretroviral regimens on lipid levels in HIV seropositive individuals who have not received lipid-lowering agents. METHODS: Data consisted of 595 patients participating in the population-based Athens Multicenter Cohort Study who were consistently followed up during 1996-2008. RESULTS: In naïve patients, lipid parameters increased sharply during the first 3 months of antiretroviral therapy and reached a plateau level approximately 6-9 months after therapy initiation. The plateau levels remained almost stable for up to 3.5 years. In general, bPIs exerted a more pronounced effect compared to NNRTIs. CONCLUSIONS: The administration of PI- or NNRTI-based regimens especially in naïve but also in unboosted PI experienced patients provoked a sharp increase in lipid levels that remained stable in higher levels for more than 3 years.

The optimal home blood pressure monitoring schedule based on the Didima outcome study.

This study investigated the optimal schedule for home blood pressure (HBP) monitoring that has the greatest prognostic ability and provides the most reliable assessment of HBP. The Didima study assessed the value of HBP (duplicate morning and evening measurements, 3 days) in predicting cardiovascular events in the general population (662 adults, 8.2+/-0.2 years follow-up). Criteria for the optimal monitoring schedule were stabilization of mean HBP, its variability (standard deviation (s.d.)) and hazard ratios (HRs) of cardiovascular events per 1 mm Hg HBP increase. By averaging more readings (1-12), there was a progressive decline in average HBP and its s.d. and increase in HR, with most of these benefits achieved on the second day (8 readings) and little additional benefit obtained on the third day (12 readings). The first day gave higher and more unstable HBP values (higher s.d.) with less prognostic ability (lower HR). The first HBP readings per occasion gave higher values but with similar prognostic ability as the second readings taken 1 min later. There was little difference in average HBP between morning and evening readings with no prognostic superiority of morning readings. In conclusion, by averaging more readings the average HBP and its variability are reduced and the prognostic ability improved. Any aspect of HBP monitoring (first or second readings, morning or evening) has similar prognostic ability. The first day gives higher and unstable values with lower prognostic ability and should be better discarded. These data validate the HBP monitoring schedule proposed by the European Society of Hypertension.

Frequency and distribution of root filled teeth and apical periodontitis in a Greek population.

AIM: To investigate the prevalence of root filled teeth and apical periodontitis (AP) in a Greek population. METHODOLOGY: A random sample of 320 patients who required full mouth periapical radiographic examination as a part of diagnostic and planning procedures were included. The age of the patients ranged from 16 to 77 years. A total of 7664 teeth were assessed and the frequency of root filled teeth and periapical status was recorded. Two observers evaluated the radiographs under standardized conditions. AP was defined as distinct periapical radiolucency or widening of the periodontal ligament space exceeding two times the normal width. Statistical evaluation of differences in proportions between groups was performed using random effects logistic regression models. RESULTS: The periapical status of 286 (3.7%) teeth was impossible to evaluate because of radiographic faults; these teeth were excluded from further analysis. A total of 1040 (13.6%) teeth had radiographic signs of AP and 680 (9.2%) teeth had been root filled. Of the root filled teeth, 408 (60.0%) had AP. There was no difference in the number of root filled teeth between males and females; the prevalence of root filled teeth increased with age. Significantly more molars (13.1%) and premolars (11.9%) than anterior teeth (5.8%) had been root filled (P < 0.001). The prevalence of AP was significantly higher (P < 0.001) in molars (23.9%) and premolars (14.0%) than anterior teeth (9.4%). CONCLUSIONS: The prevalence of AP and the frequency of root filled teeth with AP in this Greek population were higher than those found in many other European countries. The frequency of root filled teeth was comparable with findings in other epidemiological studies.

Nerve growth factor synthesized by mouse fibroblast cells in culture: absence of alpha and gamma subunits.

Nerve growth factor (NGF) is found in high concentrations in the mouse salivary gland. However, this gland is unique since salivary glands from other animals have only trace amounts of NGF. In the mouse gland, two high molecular weight forms of NGF have been reported, 7S-NGF [Varon, S., Nomura, J., & Shooter, E.M. (1967) Biochemistry 6, 2202-2209] and NGF1 [Young, M., Saide, J.D., Murphy, R.A., & Blanchard, M.H. (1978) Biochemistry 17, 1490-1498]. 7S-NGF is comprised of three noncovalently associated subunits: beta-NGF, which is the biologically active subunit, alpha subunit, and gamma subunit. A similar subunit composition is seen with NGF1 (unpublished work with R.A. Murphy). Since the mouse salivary gland is unique with regard to its synthesis of NGF, the following question arises. Do other sources of NGF produce either 7S-NGF or NGF1? Mouse fibroblast cells (L929) in culture synthesize and secrete into their feeding medium (conditioned medium) a beta-NGF-like molecule [Pantazis, N.J., Blanchard, M.H., Arnason, B.G.W., & Young, M. (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 1492-1496]. These cells therefore provided the opportunity to examine the molecular nature of NGF produced by a nonsalivary gland source. In this study, it was determined by radioimmunoassay that neither the alpha nor the gamma subunit is present in fibroblast cell conditioned medium. Since alpha- and gamma-proteins are present in both 7S-NGF and NGF1, this indicates that neither of the salivary gland forms of NGF are produced by the mouse fibroblast cell.

Localization of the nerve growth factor receptor on fetal human Schwann cells in culture.

Previous studies have established that Schwann cells (SC) in culture express an NGF receptor. In this study, cultures of fetal human SC were established from fetal nerves and various light microscopic (LM) and electron microscopic (EM) techniques were used to localize the NGF receptor on the SC. Results indicate that NGF receptor is localized to the plasma membrane of the SC. Quantitative digital analysis determined that the distal portion of the SC process had high concentrations of NGF receptor. The possible functional significance of this latter observation is discussed in terms of SC migration and ensheathment of axons.