Estimated HIV Incidence in California, 2006–2009

Introduction

Accurate estimates of HIV incidence are crucial for prioritizing, targeting, and evaluating HIV prevention efforts. Using the methodology the CDC used to estimate national HIV incidence, we estimated HIV incidence in Los Angeles County (LAC), San Francisco (SF), and California’s remaining counties.

Methods

We estimated new HIV infections in 2006–2009 among adults and adolescents in LAC, SF and the remaining California counties using the Serologic Testing Algorithm for Recent Seroconversion (STARHS). STARHS methodology uses the BED HIV-1 capture enzyme immunoassay to determine recent HIV infections by testing remnant serum from persons newly diagnosed with HIV. A population-based incidence estimate is calculated using HIV testing data from newly diagnosed cases and imputing for persons unaware of their HIV infection.

Results

For years 2007–2009, respectively, we estimated new infections in LAC to be 2426 (95% CI 1871–2982), 1669 (CI 1309–2029) and 1898 (CI 1452–2344) (p<0.01); in SF for 2006–2009, 492 (CI 327–657), 490 (CI 335–646), 458 (CI 342–574) and 367 (CI 261–473) (p = 0.14); and in the remaining California counties in 2008–2009, 2526 (CI 1688–3364) and 2993 (CI 2141–3846) respectively. HIV infection rates among men who have sex with men (MSM) in LAC were 100 times higher than other risk populations; the SF MSM rate was 3 to 18 times higher than other demographic groups. In LAC, incidence rates among African-Americans were twice those of whites and Latinos; persons 40 years or older had lower rates of infection than younger persons.

Discussion

We report the first HIV incidence estimates for California, highlighting geographic disparities in HIV incidence and confirming national findings that MSM and African-Americans are disproportionately impacted by HIV. HIV incidence estimates can and should be used to target prevention efforts towards populations at highest risk of acquiring new HIV infections, focusing on geographic, racial and risk group disparities.     

SMi biomarkers summit, 2–3 February 2009, London,UK

As part of a programme to develop biomarker assays for polycyclic aromatic hydrocarbons (PAHs) in marine invertebrates, two species of crabs, Carcinus maenas and Carcinus aestuarii were exposed to benzo(a)pyrene (B(a)P) or crude oil. Microsomes were prepared from the midgut gland (hepatopancreas), examined by gel electrophoresis and Western blotting and assayed for B(a)P monooxygenase activity. In early experiments there was evidence of protein degradation and results were inconsistent and inconclusive. However, when steps were taken to minimize this in subsequent experiments, including the inclusion of four protease inhibitors in the homogenization buffer, there was consistent evidence for an increase of proteins of estimated molecular weight 45-60 kDa, and particularly of a distinct band at c. 48 kDa, following exposure to PAH at levels down to 0.1 ppm in ambient water. In C. aestuarii the increase in this band was found to coincide with an 8-12-fold increaseof B(a)P monooxygenase activity in midgut gland microsomes. These results suggest that one or more forms of cytochrome P450 may be induced by PAHs in these species. However, Western blotting using antibodies raised to vertebrate P450s, and representing four different gene families, failed to recognize any proteins in either the PAH-treated samples or in the controls. The isolation and characterization of induced protein, and the production of antibodies may provide the basis for a biomarker assay to measure a response to environmental PAHs in crabs.     

Trends in 1-year survival of people admitted to hospital in Ontario, 1994–2009

Background:

Changes in the long-term survival of people admitted to hospital is unknown. This study examined trends in 1-year survival of patients admitted to hospital adjusted for improved survival in the general population.

Methods:

One-year survival after admission to hospital was determined for all adults admitted to hospital in Ontario in 1994, 1999, 2004, or 2009 by linking to vital statistics datasets. Annual survival in the general population was determined from life tables for Ontario.

Results:

Between 1994 and 2009, hospital use decreased (from 8.8% to 6.3% of the general adult population per year), whereas crude 1-year mortality among people with hospital admissions increased (from 9.2% to 11.6%). During this time, patients in hospital became significantly older (median age increased from 51 to 58 yr) and sicker (the proportion with a Charlson comorbidity index score of 0 decreased from 68.2% to 60.0%), and were more acutely ill on admission (elective admissions decreased from 47.4% to 42.0%; proportion brought to hospital by ambulance increased from 16.1% to 24.8%). Compared with 1994, the adjusted odds ratio (OR) for death at 1 year in 2009 was 0.78 (95% confidence interval [CI] 0.77–0.79). However, 1-year risk of death in the general population decreased by 24% during the same time. After adjusting for improved survival in the general population, risk of death at 1 year for people admitted to hospital remained significantly lower in 2009 than in 1994 (adjusted relative excess risk 0.81, 95% CI 0.80–0.82).

Interpretation:

After accounting for both the increased burden of patient sickness and improved survival in the general population, 1-year survival for people admitted to hospital increased significantly from 1994 to 2009. The reasons for this improvement cannot be determined from these data. Hospitals have a special place in most health care systems. Hospital staff care for the people with the most serious illnesses and the most vulnerable. They are frequently the location of many life-defining moments — including birth, surgery, acute medical illness and death — of many people and their families. Hospitals serve as a focus in the training of most physicians. In addition, they consume a considerable proportion of health care expenditures worldwide. ¹ Given the prominence of hospitals in health care systems, measuring outcomes related to hospital care is important. In particular, the measurement of trends for outcomes of hospital care can help us to infer whether the care provided to hospital patients is improving. Previous such studies have focused on survival trends for specific diseases or patients who received treatment in specific departments. ^{2 – 12} None of these studies have adjusted for survival trends in the general population, the adjustment for which is important to determine whether changes in survival of patients in hospital merely reflect changes in the overall population. In this study, whether or not patient outcomes have changed over time was determined by examining trends in 1-year survival in all patients admitted to hospital, adjusting for improved survival in the general population.     

Circulation of Coxsackievirus A10 and A6 in Hand-Foot-Mouth Disease in China, 2009–2011

Coxsackieviruses A10 (CV-A10) and A6 (CV-A6) have been associated with increasingly occurred sporadic hand-foot-mouth disease (HFMD) cases and outbreak events globally. However, our understanding of epidemiological and genetic characteristics of these new agents remains far from complete. This study was to explore the circulation of CV-A10 and CV-A6 in HFMD and their genetic characteristics in China. A hospital based surveillance was performed in three heavily inflicted regions with HFMD from March 2009 to August 2011. Feces samples were collected from children with clinical diagnosis of HFMD. The detection and genotyping of enteroviruses was performed by real-time PCR and sequencing of 5′UTR/VP1 regions. Phylogenetic analysis and selection pressure were performed based on the VP1 sequences. Logistic regression model was used to identify the effect of predominant enterovirus serotypes in causing severe HFMD. The results showed 92.0% of 1748 feces samples were detected positive for enterovirus, with the most frequently presented serotypes as EV-71 (944, 54.0%) and CV-A16 (451, 25.8%). CV-A10 and CV-A6 were detected as a sole pathogen in 82 (4.7%) and 44 (2.5%) cases, respectively. Infection with CV-A10 and EV-71 were independently associated with high risk of severe HFMD (OR = 2.66, 95% CI: 1.40–5.06; OR = 4.81, 95% CI: 3.07–7.53), when adjusted for age and sex. Phylogenetic analysis revealed that distinct geographic and temporal origins correlated with the gene clusters based on VP1 sequences. An overall ω value of the VP1 was 0.046 for CV-A10 and 0.047 for CV-A6, and no positively selected site was detected in VP1 of both CV-A10 and CV-A6, indicating that purifying selection shaped the evolution of CV-A10 and CV-A6. Our study demonstrates variety of enterovirus genotypes as viral pathogens in causing HFMD in China. CV-A10 and CV-A6 were co-circulating together with EV-71 and CV-A16 in recent years. CV-A10 infection might also be independently associated with severe HFMD.     

Genetics of osteoarticular disorders,Florence, Italy, 22–23 February 2002

Osteoporosis (OP) and osteoarthritis (OA), the two most common age-related chronic disorders of articular joints and skeleton, represent a major public health problem in most developed countries. They are influenced by environmental factors and exhibit a strong genetic component. Large population studies clearly show their inverse relationship; therefore, an accurate analysis of the genetic bases of one of these two diseases may provide data of interest for the other disorder. The discovery of risk and protective genes for OP and OA promises to revolutionize strategies for diagnosing and treating these disorders. The primary goal of this symposium was to bring together scientists and clinicians working on OP and OA in order to identify the most promising and collaborative approaches for the coming decade. This meeting put into focus the importance of an adequate genetic approach to several areas of research: the search for the genetic determinants underlying new susceptibilities, the optimization of previously acquired data; the establishment of correlations between genetic polymorphism and functional variants, and gene–gene and gene–environment interactions (particularly those between genes and nutrients). An adequate genetic approach is also essential with regard to determining more selective criteria for phenotypic definition of familial OP, in order to obtain more homogeneous and statistically powerful family-based studies. The symposium concluded with an interesting overview of the future perspectives offered by DNA microarray technologies for identifying novel candidate genes, for developing proteomics and bioinformatics analyses and for designing low-cost clinical trials.     

Genomic characterization of invasive meningococcal X isolates from Brazil, 1992–2022

International Microbiology - Invasive meningococcal disease (IMD) is a major health problem. Given the post-COVID-19 pandemic scenario with the loosening of the non-pharmacological measures to...     

Thermal, mixing, and oxygen regimes of the Salton Sea, California, 1997–1999

The Salton Sea is a shallow (mean depth = 8 m; maximum depth = 15 m), saline (41–45 g l^–1), intermittently mixing, 57 km long, 980 km² lake located in the arid southwestern United States. The Sea is a wind driven system, with predominant winds paralleling the long axis of the lake, being strongest in spring and weakest in summer and fall. The Sea mixed daily or nearly daily between September and January. During this cooling period, moderate to high levels of dissolved oxygen (3–11 mg l^–1) were found throughout the water column. Mean water column temperature ranged from a minimum of 13–14 °C in early January to a maximum of 30–34 °C in July–September. During most of this warming period, the Sea was thermally stratified but subject to periodic wind driven mixing events. Winds were stronger in spring 1998 than in 1997 or 1999, causing more rapid heating of the lake that year and also delaying onset of anoxic conditions in bottom waters. During summer months, mid-lake surface waters were sometimes supersatured with oxygen, and bottom waters were hypoxic or anoxic with sulfide concentrations > 5 mg l^–1. Oxic conditions (> 1 mg O₂ l^–1) often extended a few meters deeper nearshore than they did well offshore as a consequence of greater mixing nearshore. Mixing events in late summer deoxygenated the entire water column for a period of days. Consumption of oxygen by sulfide oxidation likely was the principal mechanism for these deoxygenation events. Sulfide concentrations in surface waters were 0.5–1 mg l^–1 approximately 3 days after one mixing event in mid-August 1999. These mixing events were associated with population crashes of phytoplankters and zooplankters and with large fish kills. In the southern basin, freshwater inflows tended to move out over the surface of the Sea mixing with saline lake water as a function of wind conditions. Salinity gradients often contributed more to water column stability than did thermal gradients in the southeasternmost portion of the lake.     

World Antibody Drug Conjugate Summit Europe: February 21–23, 2011; Frankfurt,Germany

The World Antibody Drug Conjugate Summit Europe, organized by Biorbis/Hanson Wade was held in Frankfurt, Germany February 21–23, 2011. Antibody drug conjugates (ADCs), also called immunoconjugates, are becoming an increasingly important class of therapeutics as demonstrated by the attendance of nearly 100 delegates at this highly focused meeting. Updates on three ADCs that are in late-stage clinical development, trastuzumab emtansine (T-DM1), brentuximab vedotin (SGN-35) and inotuzumab ozogamicin (CMC-544), were presented by speakers from ImmunoGen, Genentech, Roche, Seattle Genetics and Pfizer. These ADCs have shown encouraging therapeutic effects against solid tumors (T-DM1) and hematological malignancies (SGN-35, CMC-544). The key feature of the new generation of ADCs is the effective combination of the cytotoxicity of natural or synthetic highly potent antineoplastic agents, tumor selective monoclonal antibodies and blood-stable optimized linkers. Early clinical data for ADCs were showcased by Progenics Pharmaceuticals (PSMA ADC), Celldex (CDX-011) and Biotest (BT-062). Takeda, MedImmune and sanofi-aventis outlined their strategies for process development and analytical characterization. In addition, presentations on duocarmycin based-ADCs, α emitting immunoconjugates and antibody-conjugated nanoparticles were given by representatives from Syntarga, Algeta and the University of Stuttgart, respectively.Key words: antibody drug conjugates, immunoconjugates, trastuzumab emtansine, brentuximab vedotin, inotuzumab ozogamicin, oncology, cancer     

Effects of Spontaneous Bilayer Curvature on Influenza Virus–mediated Fusion Pores

Cells expressing the hemagglutinin protein of influenza virus were fused to planar bilayer membranes containing the fluorescent lipid probes octadecylrhodamine (R18) or indocarbocyanine (DiI) to investigate whether spontaneous curvature of each monolayer of a target membrane affects the growth of fusion pores. R18 and DiI lowered the transition temperatures for formation of an inverted hexagonal phase, indicating that these probes facilitate the formation of negative curvature structures. The probes are known to translocate from one monolayer of a bilayer membrane to the other in a voltage-dependent manner. The spontaneous curvature of the cis monolayer (facing the cells) or the trans monolayer could therefore be made more negative through control of the polarity of voltage across the planar membrane. Electrical admittance measurements showed that the open times of flickering fusion pores were shorter when probes were in trans monolayers and longer when in cis monolayers compared with times when probe was symmetrically distributed. Open times were the same for probe symmetrically distributed as when probes were not present. Thus, open times were a function of the asymmetry of the spontaneous curvature between the trans and cis monolayers. Enriching the cis monolayer with a negative curvature probe reduced the probability that a small pore would fully enlarge, whereas enriching the trans monolayer promoted enlargement. Lysophosphatidylcholine has positive spontaneous curvature and does not translocate. When lysophosphatidylcholine was placed in trans leaflets of planar membranes, closing of fusion pores was rare. The effects of the negative and positive spontaneous curvature probes do not support the hypothesis that a flickering pore closes from an open state within a hemifusion diaphragm (essentially a “flat” structure). Rather, such effects support the hypothesis that the membrane surrounding the open pore forms a three-dimensional hourglass shape from which the pore flickers shut.     

Saccharomyces cerevisiae–Based Platform for Rapid Production and Evaluation of Eukaryotic Nutrient Transporters and Transceptors for Biochemical Studies and Crystallography

To produce large quantities of high quality eukaryotic membrane proteins in Saccharomyces cerevisiae, we modified a high-copy vector to express membrane proteins C-terminally-fused to a Tobacco Etch Virus (TEV) protease detachable Green Fluorescent Protein (GFP)-8His tag, which facilitates localization, quantification, quality control, and purification. Using this expression system we examined the production of a human glucose transceptor and 11 nutrient transporters and transceptors from S. cerevisiae that have not previously been overexpressed in S. cerevisiae and purified. Whole-cell GFP-fluorescence showed that induction of GFP-fusion synthesis from a galactose-inducible promoter at 15°C resulted in stable accumulation of the fusions in the plasma membrane and in intracellular membranes. Expression levels of the 12 fusions estimated by GFP-fluorescence were in the range of 0.4 mg to 1.7 mg transporter pr. liter cell culture. A detergent screen showed that n-dodecyl-ß-D-maltopyranoside (DDM) is acceptable for solubilization of the membrane-integrated fusions. Extracts of solubilized membranes were prepared with this detergent and used for purifications by Ni-NTA affinity chromatography, which yielded partially purified full-length fusions. Most of the fusions were readily cleaved at a TEV protease site between the membrane protein and the GFP-8His tag. Using the yeast oligopeptide transporter Ptr2 as an example, we further demonstrate that almost pure transporters, free of the GFP-8His tag, can be achieved by TEV protease cleavage followed by reverse immobilized metal-affinity chromatography. The quality of the GFP-fusions was analysed by fluorescence size-exclusion chromatography. Membranes solubilized in DDM resulted in preparations containing aggregated fusions. However, 9 of the fusions solubilized in DDM in presence of cholesteryl hemisuccinate and specific substrates, yielded monodisperse preparations with only minor amounts of aggregated membrane proteins. In conclusion, we developed a new effective S. cerevisiae expression system that may be used for production of high-quality eukaryotic membrane proteins for functional and structural analysis.     

Tat–Dependent Translocation of an F420–Binding Protein of Mycobacterium tuberculosis

F₄₂₀ is a unique cofactor present in a restricted range of microorganisms, including mycobacteria. It has been proposed that F₄₂₀ has an important role in the oxidoreductive reactions of Mycobacterium tuberculosis, possibly associated with anaerobic survival and persistence. The protein encoded by Rv0132c has a predicted N–terminal signal sequence and is annotated as an F₄₂₀–dependent glucose-6-phosphate dehydrogenase. Here we show that Rv0132c protein does not have the annotated activity. It does, however, co–purify with F₄₂₀ during expression experiments in M. smegmatis. We also show that the Rv0132c–F₄₂₀ complex is a substrate for the Tat pathway, which mediates translocation of the complex across the cytoplasmic membrane, where Rv0132c is anchored to the cell envelope. This is the first report of any F₄₂₀–binding protein being a substrate for the Tat pathway and of the presence of F₄₂₀ outside of the cytosol in any F₄₂₀–producing microorganism. The Rv0132c protein and its Tat export sequence are essentially invariant in the Mycobacterium tuberculosis complex. Taken together, these results show that current understanding of F₄₂₀ biology in mycobacteria should be expanded to include activities occurring in the extra-cytoplasmic cell envelope.     

Occurrence,distribution and transport of pesticides into the Salton Sea Basin,California, 2001–2002

The Salton Sea is a hypersaline lake located in southeastern California. Concerns over the ecological impacts of sediment quality and potential human exposure to dust emissions from exposed lakebed sediments resulting from anticipated shrinking of shoreline led to a study of pesticide distribution and transport within the Salton Sea Basin, California, in 2001–2002. Three sampling stations—upriver, river mouth, and offshore—were established along each of the three major rivers that discharge into the Salton Sea. Large-volume water samples were collected for analysis of pesticides in water and suspended sediments at the nine sampling stations. Samples of the bottom sediment were also collected at each site for pesticide analysis. Sampling occurred in October 2001, March–April 2002, and October 2002, coinciding with the regional fall and spring peaks in pesticide use in the heavily agricultural watershed. Fourteen current-use pesticides were detected in water and the majority of dissolved concentrations ranged from the limits of detection to 151 ng/l. Diazinon, EPTC and malathion were detected at much higher concentrations (940–3,830 ng/l) at the New and Alamo River upriver and near-shore stations. Concentrations of carbaryl, dacthal, diazinon, and EPTC were higher in the two fall sampling periods, whereas concentrations of atrazine, carbofuran, and trifluralin were higher during the spring, which matched seasonal use patterns of these pesticides. Current-use pesticides were also detected on suspended and bed sediments in concentrations ranging from detection limits to 106 ng/g. Chlorpyrifos, dacthal, EPTC, trifluralin, and DDE were the most frequently detected pesticides on sediments from all three rivers. The number of detections and concentrations of suspended sediment-associated pesticides were often similar for the river upriver and near-shore sites, consistent with downstream transport of pesticides via suspended sediment. While detectable suspended sediment pesticide concentrations were more sporadic than detected aqueous concentrations, seasonal trends were similar to those for dissolved concentrations. Generally, the pesticides detected on suspended sediments were the same as those on the bed sediments, and concentrations were similar, especially at the Alamo River upriver site. With a few exceptions, pesticides were not detected in suspended or bed sediments from the off-shore sites. The partitioning of pesticides between water and sediment was not predictable from solely the physical–chemical properties of individual pesticide compounds, but appear to be a complicated function of the quantity of pesticide applied in the watershed, residence time of sediments in the water, and compound solubility and hydrophobicity. Sediment concentrations of most pesticides were found to be 100–1,000 times lower than the low-effects levels determined in human health risk assessment studies. However, maximum concentrations of chlorpyrifos on suspended sediments were approximately half the low-effects level, suggesting the need for further sediment characterization of lake sediments proximate to riverine inputs. Guest editor: S. H. Hurlbert The Salton Sea Centennial Symposium. Proceedings of a Symposium Celebrating a Century of Symbiosis Among Agriculture, Wildlife and People, 1905–2005, held in San Diego, California, USA, March 2005     

Integral role of the I′-helix in the function of the “inactive” C-terminal domain of catalase–peroxidase (KatG)

Catalase–peroxidases (KatGs) have two peroxidase-like domains. The N-terminal domain contains the heme-dependent, bifunctional active site. Though the C-terminal domain lacks the ability to bind heme or directly catalyze any reaction, it has been proposed to serve as a platform to direct the folding of the N-terminal domain. Toward such a purpose, its I′-helix is highly conserved and appears at the interface between the two domains. Single and multiple substitution variants targeting highly conserved residues of the I′-helix were generated for intact KatG as well as the stand-alone C-terminal domain (KatG^C). Single variants of intact KatG produced only subtle variations in spectroscopic and catalytic properties of the enzyme. However, the double and quadruple variants showed substantial increases in hexa-coordinate low-spin heme and diminished enzyme activity, similar to that observed for the N-terminal domain on its own (KatG^N). The analogous variants of KatG^C showed a much more profound loss of function as evaluated by their ability to return KatG^N to its active conformation. All of the single variants showed a substantial decrease in the rate and extent of KatG^N reactivation, but with two substitutions, KatG^C completely lost its capacity for the reactivation of KatG^N. These results suggest that the I′-helix is central to direct structural adjustments in the adjacent N-terminal domain and supports the hypothesis that the C-terminal domain serves as a platform to direct N-terminal domain conformation and bifunctionality.