Defusing inflammasomes.

In this issue of JEM, Boucher et al. (https://doi.org/10.1084/jem.20172222) report isolation of active caspase-1 from macrophages after inflammasome activation. Surprisingly, they find that caspase-1 is quickly inactivated upon autoproteolytic processing

The Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE): The Dust Extinction Curve from Red Clump Stars

We use Hubble Space Telescope (HST) observations of red clump stars taken as part of the Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE) program to measure the average dust extinction curve in a ~ 200 pc x 100 pc region in the southwest bar of the Small Magellanic Cloud (SMC). The rich information provided by our 8-band ultra-violet through near-infrared photometry allows us to model the color-magnitude diagram of the red clump accounting for the extinction curve shape, a log-normal distribution of $A_{V}$, and the depth of the stellar distribution along the line of sight. We measure an extinction curve with $R_{475} = A_{475}/(A_{475}-A_{814})$ = 2.65 $\pm$ 0.11. This measurement is significantly larger than the equivalent values of published Milky Way $R_{V}$ = 3.1 ($R_{475} = 1.83$) and SMC Bar $R_{V}$ = 2.74 ($R_{475} = 1.86$) extinction curves. Similar extinction curve offsets in the Large Magellanic Cloud (LMC) have been interpreted as the effect of large dust grains. We demonstrate that the line-of-sight depth of the SMC (and LMC) introduces an apparent "gray" contribution to the extinction curve inferred from the morphology of the red clump. We show that no gray dust component is needed to explain extinction curve measurements when a full-width half-max depth of 10 $\pm$ 2 kpc in the stellar distribution of the SMC (5 $\pm$ 1 kpc for the LMC) is considered, which agrees with recent studies of Magellanic Cloud stellar structure. The results of our work demonstrate the power of broad-band HST imaging for simultaneously constraining dust and galactic structure outside the Milky Way.Comment: 16 pages, 12 figures, 5 tables. Accepted for publication in Ap

The JWST Resolved Stellar Populations Early Release Science Program I.: NIRCam Flux Calibration

We use globular cluster data from the Resolved Stellar Populations Early Release Science (ERS) program to validate the flux calibration for the Near Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST). We find a significant flux offset between the eight short wavelength detectors, ranging from 1-23% (about 0.01-0.2 mag) that affects all NIRCam imaging observations. We deliver improved zeropoints for the ERS filters and show that alternate zeropoints derived by the community also improve the calibration significantly. We also find that the detector offsets appear to be time variable by up to at least 0.1 mag.Comment: Accepted for publication in RNAA

Patterns of sexually transmitted infections in adolescents and youth in Dar es Salaam, Tanzania

BACKGROUND: Syndromic management of STIs has been advocated as simplified and cheap approach. Youth have been reported to be at increased risk of acquiring STIs which can facilitate HIV transmission. We have investigated the relationship between the syndromic management and specific aetiology diagnosis and its relationship with HIV infection and health seeking behaviour among youth attending a reproductive health clinic in Dar es Salaam, Tanzania. METHODS: Between September 1998 and February 1999 among 1895 adolescents and youth below 25 years seen in the clinic 199 (10.5%) were randomly selected and consented to participate in the study. A standard questionnaire was administered. Blood and vaginal or urethral specimens were taken and investigated for STI causative agents. RESULTS: Among a total of 199 studied adolescents and youth 22.6 % were teenagers, with fewer females 17.8% than males; 27.5% (p < 0.018). 20.8% of the females compared to 11.5% in males were HIV infected. Genital discharge was the most common complaint which was reported in 54.1% of male and 63.4 % of female patients. All males with gonorrhoea and four out of five with Chlamydia were given appropriate treatment with syndromic management, while 28% women with gonorrhoea or Chlamydia received appropriate treatment by syndromic management. All patients found with active syphilis by serology had not complained of genital ulcers and would not have been assigned to syndromic treatment for syphilis at the initial visit. CONCLUSION: The burden of STIs in this youth population is large indicating that youth are at increased risk of STIs and will certainly require youth friendly clinics. There is a need to refine the current syndromic management guidelines

Effect of Improved access to Antiretroviral Therapy on clinical characteristics of patients enrolled in the HIV care and treatment clinic, at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania

\ud Sub-Saharan Africa has been severely affected by the HIV and AIDS pandemic. Global efforts at improving care and treatment has included scaling up use of antiretroviral therapy (ART). In Tanzania, HIV care and treatment program, including the provision of free ART started in 2004 with a pilot program at Muhimbili National Hospital in Dar es Salaam. This study describes the socio-demographic and clinical features of patients enrolled at the care and treatment clinic at MNH, Dar es Salaam, Tanzania. A cross-sectional study looking at baseline characteristics of patients enrolled at the HIV clinic at MNH between June 2004-Dec 2005 compared to those enrolled between 2006 and September 2008. Of all enrolled patients, 2408 (58.5%) were used for analysis. More females than males were attending the clinic. Their baseline median CD4 cell count was low (136 cells/microl) with 65.7% having below 200 cells/microl. Females had higher CD4 cell counts (150 cells/microl) than males (109 cells/microl) p < 0.001). The most common presenting features were skin rash and/or itching (51.6%); progressive weight loss (32.7%) and fever (23.4). Patients enrolled earlier at the clinic (2004-5) were significantly more symptomatic and had significantly lower CD4 cell count (127 cells/microl) compared to CD4 of 167 cells/microl in those seen later (2006-8) (p < 0.001). Patients enrolled to the MNH HIV clinic were predominantly females, and presented with advanced immune-deficiency. Improved access to HIV care and treatment services seems to be associated with patients' early presentation to the clinics in the course of HIV disease.\u

CmeABC multidrug efflux pump contributes to antibiotic resistance and promotes 'Campylobacter jejuni' survival and multiplication in 'Acanthamoeba polyphaga'

Campylobacter jejuni is a foodborne pathogen recognized as the leading cause of human bacterial gastroenteritis. The wide use of antibiotics in medicine and in animal husbandry has led to an increased incidence of antibiotic resistance in Campylobacter In addition to a role in multidrug resistance, the Campylobacter CmeABC RND-type efflux pump, which is associated with multidrug resistance (MDR), may also be involved in virulence. As a vehicle of pathogenic microorganisms, the protozoan Acanthamoeba is a good model for the investigation of bacterial survival in the environment and molecular mechanisms of pathogenicity. The interaction between C. jejuni 81-176 and A. polyphaga was investigated in this study by using a modified gentamicin protection assay. In addition, a possible role for the CmeABC MDR pump in this interaction was explored. Here we report that this MDR pump is beneficial for the intracellular survival and multiplication of C. jejuni in A. polyphaga, but is dispensable for biofilm formation and motility.Importance The endosymbiotic relationship between amoebae and microbial pathogens may contribute to persistence and spreading of the latter in the environment, which has significant implications to human health. In this study we found that Campylobacter jejuni was able to survive and multiply inside Acanthamoeba. polyphaga Since these microorganisms can co-exist in the same environment (e.g. in poultry farms), the latter may increase the risk of infection with Campylobacter Our data suggests that, in addition to its role in antibiotic resistance, the CmeABC MDR efflux pump also plays a role in bacterial survival within amoebae. Furthermore, we demonstrated a synergistic effect of the CmeABC MDR efflux pump and TetO on bacterial resistance to tetracycline. Due to its role both in antibiotic resistance and virulence of C. jejuni, the CmeABC MDR efflux pump could be considered as a good target for the development of antibacterial drugs against this pathogen