The synthesis of xyloglucan, an abundant plant cell wall polysaccharide, requires CSLC function.

Xyloglucan (XyG) is an abundant component of the primary cell walls of most plants. While the structure of XyG has been well studied, much remains to be learned about its biosynthesis. Here we employed reverse genetics to investigate the role of Arabidopsis cellulose synthase like-C (CSLC) proteins in XyG biosynthesis. We found that single mutants containing a T-DNA in each of the five Arabidopsis CSLC genes had normal levels of XyG. However, higher-order cslc mutants had significantly reduced XyG levels, and a mutant with disruptions in all five CSLC genes had no detectable XyG. The higher-order mutants grew with mild tissue-specific phenotypes. Despite the apparent lack of XyG, the cslc quintuple mutant did not display significant alteration of gene expression at the whole-genome level, excluding transcriptional compensation. The quintuple mutant could be complemented by each of the five CSLC genes, supporting the conclusion that each of them encodes a XyG glucan synthase. Phylogenetic analyses indicated that the CSLC genes are widespread in the plant kingdom and evolved from an ancient family. These results establish the role of the CSLC genes in XyG biosynthesis, and the mutants described here provide valuable tools with which to study both the molecular details of XyG biosynthesis and the role of XyG in plant cell wall structure and function.

Bartonella quintana Infection in People Experiencing Homelessness in the Denver Metropolitan Area.

BACKGROUND: Bartonella quintana is an important cause of infection amongst people experiencing homelessness that is underdiagnosed due to its nonspecific clinical manifestations. We reviewed cases identified in the Denver metropolitan area in 2016-2021. METHODS: The electronic medical records from 2 large academic medical centers in Colorado were reviewed for demographic, clinical, and laboratory features of patients with B. quintana infection confirmed by blood culture, serologies, and/or molecular testing from July 2016 to December 2021. RESULTS: Fourteen patients with B. quintana infection were identified. The mean age was 49.5 years (SD 12.7 years) and 92.9% of patients were male. Twelve patients had history of homelessness (85.7%) and 11 were experiencing homelessness at the time of diagnosis (78.6%). Most frequent comorbidities included substance use (78.6%), of which 42.9% had alcohol use disorder. The average time to blood culture positivity was 12.1 days (SD 6.2 days). Three patients with bacteremia had negative B. quintana IgG, and 6 of 14 (42.8%) patients had evidence of endocarditis on echocardiography. CONCLUSIONS: B. quintana is an underrecognized cause of serious infection in individuals experiencing homelessness. Serologic and microbiologic testing, including prolonged culture incubation, should be considered in at-risk patients due to ongoing transmission in homeless populations.

Retrospective analysis of the management of pelvic decubitus ulcers and their outcomes.

Background: Many patients with decubitus-related osteomyelitis are ineligible for myocutaneous flapping, and optimal management in this population is unknown. We describe treatments and outcomes of hospitalized patients with decubitus ulcer-related osteomyelitis who did not undergo surgical reconstruction or coverage. Methods: We systematically identified hospitalized patients with diagnoses of pelvic, sacral, or femoral osteomyelitis due to decubitus ulceration between 1 January 2018 and 31 December 2018. Demographics, comorbidities, laboratory data, and outcomes were collected by manual chart review. T-tests or Chi-square tests were used for descriptive statistical comparisons; logistic regressions were used to explore the odds of readmission, osteomyelitis-related readmission, and death. Results: Of 89 patients meeting inclusion criteria, 34 (38%) received surgical debridement and ⩾6 weeks of antibiotics; 55 (62%) received either antibiotics alone or debridement and <6 weeks of antibiotics. Mean age was 55 (standard deviation 18) years, 55% of patients were male, and 69% had spinal cord injury or other form of paralysis. Within 1 year, 56 (63%) patients were readmitted, 38 (44%) patients were readmitted due to complications from osteomyelitis, and 15 (17%) died. We found no significant differences in readmission (OR = 1.33, 95% CI: 0.54-3.21, p = 0.53), readmission related to osteomyelitis (OR = 1.64, 95% CI: 0.69-4.04, p = 0.27), subsequent sepsis (OR = 2.27, 95% CI: 0.83-6.93, p = 0.13), or death (OR = 2.88, 95% CI: 0.83-13.4, p = 0.12) by treatment group. Conclusions: Among patients with decubitus-related osteomyelitis who did not undergo myocutaneous flapping, outcomes were generally poor regardless of treatment, and not significantly improved with prolonged antibiotics. Prospective studies are needed to assess best practice strategies for this challenging patient population.

Coxiella burnetii Infection Associated With Thromboangiitis Obliterans-like Phenomena With Digital Autoamputation: A Case Report and Review of Q Fever-Associated Autoimmunity.

We present a case of a patient with chronic Q fever who presented with digital necrosis, autoamputations, and positive anticentromere antibody, mimicking a scleroderma vasculopathy or thromboangiitis obliterans. Coxiella burnetii infection has long been associated with the presence of autoantibodies and autoimmune phenomena including vasculitis. Clinicians should consider Q fever testing in patients with new-onset autoimmune diseases or autoantibodies and appropriate exposure histories.

Common Dermatologic Conditions in Returning Travelers.

PURPOSE OF REVIEW: Travel medicine practitioners often are confronted with returning travelers with dermatologic disorders that could be of infectious causes or inflammatory or allergic. Some dermatologic processes are the result of exposure to insects or acquired due to environmental exposures. There is a broad range of dermatosis of infectious and non-infectious etiologies that clinicians need to consider in the differential diagnosis of dermatosis in travelers. RECENT FINDINGS: With increasing international travel to tropical destinations, many individuals may be exposed to rickettsia (i.e., African tick bite fever, scrub typhus, or Mediterranean spotted fever), parasitic infections (i.e., cutaneous larva migrans, cutaneous leishmaniasis, African trypanosomiasis, or American trypanosomiasis), viral infections (i.e., measles or Zika virus infection), bacterial (i.e., Buruli ulcer) or ectoparasites (scabies or tungiasis), and myiasis. Cutaneous lesions provide clinical clues to the diagnosis of specific exposures during travel among returned travelers. SUMMARY: Dermatologic disorders represent the third most common health problem in returned travelers, after gastrointestinal and respiratory illness. Many of these conditions may pose a risk of severe complications if there is any delay in diagnosis. Therefore, clinicians caring for travelers need to become familiar with the most frequent infectious and non-infectious skin disorders in travelers.

Physicochemical implications of cyanobacteria oxidation with Fe(VI).

Increases in harmful algal blooms has negatively impacted many surface-sourced drinking water utilities. To control these blooms, many water utilities implement pre-oxidation with ozone, chlorine, or permanganate; however, pre-oxidation of algae has both positive and negative water quality outcomes. This study investigated ferrate (Fe(VI)) as an alternative oxidant by measuring its effect on cell lysing, surface characteristics, and coagulation in waters containing the cyanobacteria Microcystis aeruginosa. Bench scale studies were conducted to examine the complex combination of processes in a Fe(VI)-algae system. These processes were characterized by fluorescence index, surface charge, collision frequency modeling, particle counts and sphericity, total nitrogen, and ferrate decomposition measurements. Results showed that Fe(VI) lysed algal cells, but further oxidation of released organic matter is possible. The presence of algae did not significantly impact the rate of Fe(VI) decomposition. Fe(VI) pre-oxidation may also be capable of decreasing the formation of nitrogenated disinfection byproducts through subsequent oxidation of released nitrogen rich organic matter. Streaming current and zeta potential results indicate destabilization of the resulting algae and iron suspension was incomplete under most conditions. Particle collision frequency modeling indicates fluid shear to be an important aggregation mechanism of the resulting suspension. Overall, Fe(VI) is a viable alternative to other strong oxidants for water utilities struggling with harmful algal blooms, but the final fate of the resulting organic matter must be further studied.

Dermatologic Manifestations of Tick-borne Diseases in Travelers.

PURPOSE OF REVIEW: International and domestic travelers may acquire a wide variety of infectious diseases transmitted by exposure to insects. Exposure to ticks may be associated with systemic infections clinically suspected through skin and soft tissue manifestations along with fever, myalgia, headache, and other related symptoms. Cutaneous lesions may include eschars at the site of initial contact, maculopapular rashes, or others as the result of systemic dissemination of viral, Rickettsial, parasitic, and protozoan infections acquired by exposure to different types of ticks. RECENT FINDINGS: Ticks represent the second most common global vector of transmission of infectious diseases to humans after mosquitoes. In some endemic regions, ticks are the most important vector of transmission of a great variety of infectious pathogens including protozoan (Babesia spp.), viral (Coltivirus), rickettsia, and bacterial infections (Francisella tularensis). With increasing international travel, different tick-borne diseases continue to emerge and being identified. SUMMARY: Identifying the cutaneous signs associated with tick-borne diseases is crucial to clinically suspect the diagnosis of a specific tick-borne illness. Minimizing the exposure to ticks during domestic or international travel represents the most important intervention to reducing the risk of tick-borne illnesses.

Disparities in Kaposi sarcoma incidence and survival in the United States: 2000-2013.

OBJECTIVE: Geographic and racial disparities may contribute to variation in the incidence and outcomes of HIV-associated cancers in the United States. METHOD: Using the Surveillance, Epidemiology, and End Results (SEER) database, we analyzed Kaposi sarcoma (KS) incidence and survival by race and geographic region during the combined antiretroviral therapy era. Reported cases of KS in men from 2000 to 2013 were obtained from 17 SEER cancer registries. Overall and age-standardized KS incidence rates were calculated and stratified by race and geographic region. We evaluated incidence trends using joinpoint analyses and calculated adjusted hazard ratios (aHR) for overall and KS-specific mortality using multivariable Cox proportional hazards models. RESULTS: Of 4,455 KS cases identified in men younger than 55 years (median age 40 years), the annual percent change (APC) for KS incidence significantly decreased for white men between 2001 and 2013 (APC -4.52, p = 0.02). The APC for AA men demonstrated a non-significant decrease from 2000-2013 (APC -1.84, p = 0.09). Among AA men in the South, however, APC has significantly increased between 2000 and 2013 (+3.0, p = 0.03). In addition, compared with white men diagnosed with KS during the same time period, AA men were also more likely to die from all causes and KS cancer-specific causes (aHR 1.52, 95% CI 1.34-1.72, aHR 1.49, 95% CI 1.30-1.72 respectively). CONCLUSION: Although overall KS incidence has decreased in the U.S., geographic and racial disparities in KS incidence and survival exist.

Facilitating a More Efficient Commercial Review Process for Pediatric Drugs and Biologics.

Over the past two decades, the biopharmaceutical industry has seen unprecedented expansion and innovation in concert with significant technological advancements. While the industry has experienced marked growth, the regulatory system in the United States still operates at a capacity much lower than the influx of new drug and biologic candidates. As a result, it has become standard for months or even years of waiting for commercial approval by the U.S. Food and Drug Administration. These regulatory delays have generated a system that stifles growth and innovation due to the exorbitant costs associated with awaiting approval from the nation's sole regulatory agency. The recent re-emergence of diseases that impact pediatric demographics represents one particularly acute reason for developing a regulatory system that facilitates a more efficient commercial review process. Herein, we present a range of initiatives that could represent early steps toward alleviating the delays in approving life-saving therapeutics.