Microsporum canis pseudomycetoma and disseminated Mycobacterium genavense infection in an HIV/AIDS patient, an unusual combination

Pseudomycetomas are rare fungal subcutaneous infections caused by dermatophytes, which are mainly observed in immunocompromised patients. Mycobacterium genavense is considered an opportunistic pathogen in people living with HIV/AIDS (PLWHA), clinically resembling the presentation of Mycobacterium avium complex (MAC). Here, we describe the case of a 26-year-old PLWHA with a 3-month history of a 4cm tumoral, duroelastic and painful lesion located on the back. Histopathology of the tumoral lesion revealed chronic granulomatous inflammation with grains composed of PAS-positive and Grocott-positive septate hyphae, as well as acid-fast bacilli (AFB). Culture on Sabouraud and lactrimel agar developed colonies that were later identified as Microsporum canis. In successive samples, the AFB were identified as M. genavense by restriction analysis of PCR products. Immunocompromised PLWHA not only suffer increased susceptibility to diseases due to unusual pathogens but also atypical clinical presentation of frequently encountered pathogens.

Post-diagnosis serum 25-hydroxyvitamin D concentrations in women treated for breast cancer participating in a lifestyle trial in Italy

OBJECTIVE

To report cross-sectionally serum levels of 25-hydroxyvitamin D [25(OH)D] in women living in Italy within 12 months from breast cancer (BC) diagnosis.

METHODS

Baseline data were obtained from 394 women diagnosed with primary BC, enrolled from 2016 to 2019 in a lifestyle trial conducted in Italy. Subjects' characteristics were compared between two 25(OH)D concentrations (hypovitaminosis D<20 and ≥20 ng/mL) with the Chi-squared test or Fisher's exact test for small-expected counts. Using multiple logistic regression-adjusted models, we estimated odds ratios (ORs) of hypovitaminosis D with 95% confidence intervals (CIs) in the total sample and in the unsupplemented subgroup.

RESULTS

Hypovitaminosis D was found in 39% of all subjects, 60% in unsupplemented subjects, and 10% in supplemented subjects. Increasing ORs of hypovitaminosis D were found with increasing body mass index, 25-30, >30, and ≥35 versus <25 kg/m2 (ORs: 2.50, 4.64, and 5.81, respectively, in the total cohort and ORs: 2.68, 5.38, and 7.08 in the unsupplemented); living in the most southern Italian region (OR 2.50, 95%CI 1.22-5.13); and with hypertriglyceridemia (OR 2.46; 95%CI 1.16-5.22), chemotherapy history (OR 1.86, 95%CI 1.03-3.38), and inversely with anti-estrogenic therapy (OR 0.43, 95%CI 0.24-0.75) in the total sample.

CONCLUSIONS

Hypovitaminosis D in women recently diagnosed with BC and participating in a lifestyle trial in Italy was widespread and highest with obesity, hypertriglyceridemia, and chemotherapy use. Considering that hypovitaminosis D is a risk factor for lower efficacy of bone density treatments and possibly BC mortality, our results suggest the need to promptly address and treat vitamin D deficiency.

Neutralizing IFN-γ autoantibodies are rare and pathogenic in HLA-DRB1*15:02 or 16:02 individuals

BACKGROUNDWeakly virulent environmental mycobacteria (EM) can cause severe disease in HLA-DRB1*15:02 or 16:02 adults harboring neutralizing anti-IFN-γ autoantibodies (nAIGAs). The overall prevalence of nAIGAs in the general population is unknown, as are the penetrance of nAIGAs in HLA-DRB1*15:02 or 16:02 individuals and the proportion of patients with unexplained, adult-onset EM infections carrying nAIGAs.METHODSThis study analyzed the detection and neutralization of anti-IFN-γ autoantibodies (auto-Abs) from 8,430 healthy individuals of the general population, 257 HLA-DRB1*15:02 or 16:02 carriers, 1,063 patients with autoimmune disease, and 497 patients with unexplained severe disease due to EM.RESULTSWe found that anti-IFN-γ auto-Abs detected in 4,148 of 8,430 healthy individuals (49.2%) from the general population of an unknown HLA-DRB1 genotype were not neutralizing. Moreover, we did not find nAIGAs in 257 individuals carrying HLA-DRB1* 15:02 or 16:02. Additionally, nAIGAs were absent in 1,063 patients with an autoimmune disease. Finally, 7 of 497 patients (1.4%) with unexplained severe disease due to EM harbored nAIGAs.CONCLUSIONThese findings suggest that nAIGAs are isolated and that their penetrance in HLA-DRB1*15:02 or 16:02 individuals is low, implying that they may be triggered by rare germline or somatic variants. In contrast, the risk of mycobacterial disease in patients with nAIGAs is high, confirming that these nAIGAs are the cause of EM disease.FUNDINGThe Laboratory of Human Genetics of Infectious Diseases is supported by the Howard Hughes Medical Institute, the Rockefeller University, the St. Giles Foundation, the National Institutes of Health (NIH) (R01AI095983 and U19AIN1625568), the National Center for Advancing Translational Sciences (NCATS), the NIH Clinical and Translational Science Award (CTSA) program (UL1 TR001866), the French National Research Agency (ANR) under the "Investments for the Future" program (ANR-10-IAHU-01), the Integrative Biology of Emerging Infectious Diseases Laboratory of Excellence (ANR-10-LABX-62-IBEID), ANR-GENMSMD (ANR-16-CE17-0005-01), ANR-MAFMACRO (ANR-22-CE92-0008), ANRSECTZ170784, the French Foundation for Medical Research (FRM) (EQU201903007798), the ANRS-COV05, ANR GENVIR (ANR-20-CE93-003), and ANR AI2D (ANR-22-CE15-0046) projects, the ANR-RHU program (ANR-21-RHUS-08-COVIFERON), the European Union's Horizon 2020 research and innovation program under grant agreement no. 824110 (EASI-genomics), the Square Foundation, Grandir - Fonds de solidarité pour l'enfance, the Fondation du Souffle, the SCOR Corporate Foundation for Science, the Battersea & Bowery Advisory Group, William E. Ford, General Atlantic's Chairman and Chief Executive Officer, Gabriel Caillaux, General Atlantic's Co-President, Managing Director, and Head of business in EMEA, and the General Atlantic Foundation, Institut National de la Santé et de la Recherche Médicale (INSERM) and of Paris Cité University. JR was supported by the INSERM PhD program for doctors of pharmacy (poste d'accueil INSERM). JR and TLV were supported by the Bettencourt-Schueller Foundation and the MD-PhD program of the Imagine Institute. MO was supported by the David Rockefeller Graduate Program, the Funai Foundation for Information Technology (FFIT), the Honjo International Scholarship Foundation (HISF), and the New York Hideyo Noguchi Memorial Society (HNMS).

First case report of tinea corporis caused by Trichophyton indotineae in Latin America

A case of tinea corporis by Trichophyton indotineae observed in Argentina is presented. The patient had a history of having spent 18 months in Tulum, Mexico. She was suffering from tinea corporis in the anterior region of both thighs and the gluteal area. A mycological study was performed and T. mentagrophytes complex was isolated. The fungus was later identified as T. indotineae by DNA sequencing and treatment with SUBA-itraconazole was initiated with good clinical response.

Sporotrichosis in Argentina: clinical and epidemiological analysis

Introduction

Sporotrichosis is an implantation mycosis caused by Sporothrix spp. It is distributed worldwide and can be found in vegetation and soil. The most frequent route of infection is by trauma with elements contaminated with fungal propagules. Since domestic cats are the most affected animals and can transmit this infection to humans, sporotrichosis is considered a zoonosis. Clinical presentations include nodular lymphangitis, fixed cutaneous, pulmonary (rare), and disseminated (exceptional).

Objectives

To analyze the epidemiology of sporotrichosis in Argentina during 2010 and 2022. To describe the clinical presentation, diagnostic methods, and treatment of cases diagnosed during this period. To know the circulating genotypes and to observe possible associations with the geographic location where the infection was acquired.

Materials and methods

Analytical, retrospective, and observational study. We analyzed the medical records of patients with sporotrichosis from 12 health institutions in Argentina, between 2010 and 2022.

Results

We present 54 cases in which the most frequent clinical form was nodular lymphangitis, and the treatment of choice was itraconazole. Conventional diagnosis was made in all cases. Culture of clinical samples was more sensitive than direct examination because it allowed the isolation of Sporothrix spp. in all 54 cases. Molecular identification was performed in 22 cases, with Sporothrix schenkii sensu stricto being the most frequently isolated species.

Conclusions

This study allowed to know the epidemiology of this mycosis in Argentina, as well as the availability of diagnostic methods and the treatment of choice.

Preemptive Therapy in Cryptococcosis Adjusted for Outcomes

Cryptococcosis is one of the most serious opportunistic diseases in patients living with HIV. For this reason, early diagnosis and appropriate treatment are important.

OBJECTIVES

The aim of the study was to understand the development of patients diagnosed with cryptococcosis by detection of Cryptococcus antigen in serum by lateral flow assay (CrAg LFA) without nervous system involvement and with treatment in accordance with the results.

MATERIALS AND METHODS

A retrospective, longitudinal, analytical study was performed. Seventy patients with cryptococcosis initially diagnosed by serum CrAg LFA without meningeal involvement between January 2019 and April 2022 were analyzed for medical records. The treatment regimen was adapted to the results of blood culture, respiratory material, and pulmonary tomography imaging.

RESULTS

Seventy patients were included, 13 had probable pulmonary cryptococcosis, 4 had proven pulmonary cryptococcosis, 3 had fungemia, and 50 had preemptive therapy without microbiological or imaging findings compatible with cryptococcosis. Among the 50 patients with preemptive therapy, none had meningeal involvement or cryptococcosis recurrences to date.

CONCLUSION

Preemptive therapy avoided progression to meningitis in CrAg LFA-positive patients. Preemptive therapy with dose adjustment of fluconazole in patients with the mentioned characteristics was useful despite the use of lower doses than recommended.

Clinical and Demographic Features of Paracoccidioidomycosis in Argentina: A Multicenter Study Analysis of 466 Cases

Information on paracoccidioidomycosis (PCM) in Argentina is fragmented and has historically been based on estimates, supported only by a series of a few reported cases. Considering the lack of global information, a national multicentric study in order to carry out a more comprehensive analysis was warranted. We present a data analysis including demographic and clinical aspects of a historical series of 466 cases recorded over 10 years (2012-2021). Patients were aged from 1 to 89 years. The general male: female (M:F) ratio was 9.5:1 with significant variation according to the age group. Interestingly, the age range 21-30 shows an M:F ratio of 2:1. Most of the cases (86%) were registered in northeast Argentina (NEA), showing hyperendemic areas in Chaco province with more than 2 cases per 10,000 inhabitants. The chronic clinical form occurred in 85.6% of cases and the acute/subacute form occurred in 14.4% of cases, but most of these juvenile type cases occurred in northwestern Argentina (NWA). In NEA, the incidence of the chronic form was 90.6%; in NWA, the acute/subacute form exceeded 37%. Diagnosis by microscopy showed 96% positivity but antibody detection displays 17% of false negatives. Tuberculosis was the most frequent comorbidity, but a diverse spectrum of bacterial, fungal, viral, parasitic, and other non-infectious comorbidities was recorded. This national multicenter registry was launched in order to better understand the current status of PCM in Argentina and shows the two endemic zones with a highly diverse epidemiology.

[Clinical problems in Medical Mycology: Problem number 56]

We present the case of a twenty six year-old woman with rheumatoid arthritis, treated with certolizumab. She sought medical attention due to cough, fever and night sweats. X-ray exam showed a miliary pneumonia. She was treated for tuberculosis and 50days later she presented with aphasia. Magnetic nuclear resonance revealed brain lesions. Histoplasma capsulatum PCR test and urinary antigen were positive, so an antifungal treatment with voriconazole was started. Visual adverse effects forced to change the antifungal schedule in both the length of treatment and the antifungal drug. With this measure the patient progressed favorably. The test of urinary Histoplasma capsulatum antigen and PCR amplification were key to make a diagnosis and also for a follow-up.

Investigating the Origin of Mycobacterium chimaera Contamination in Heater-Cooler Units: Integrated Analysis with Fourier Transform Infrared Spectroscopy and Whole-Genome Sequencing

Mycobacterium chimaera is ubiquitously spread in the environment, including factory and hospital water systems. Invasive cases of M. chimaera infection have been associated with aerosols produced by the use of heater-cooler units (HCU) during cardiac surgery. The aim of this study was to evaluate for the first time the performance of IR-Biotyper system on a large number of M. chimaera isolates collected from longitudinal environmental HCUs samples and water sources from hospitals located in three Italian provinces. In addition, IR-Biotyper results were compared with whole-genome sequencing (WGS) analysis, the reference method for molecular epidemiology, to investigate the origin of M. chimaera contamination of HCUs. From November 2018 to May 2021, 417 water samples from 52 HCUs (Stockert 3T, n = 41 and HCU40, n = 11) and 23 hospital taps (used to fill the HCU tanks) were concentrated, decontaminated, and cultured for M. chimaera. Positive cultures (n = 53) were purified by agar plate subcultures and analyzed by IR-Biotyper platform and Ion Torrent sequencing system. IR-Biotyper spectra results were analyzed using a statistical approach of dimensionality reduction by linear discriminant analysis (LDA), generating three separate clusters of M. chimaera, ascribable to each hospital. Furthermore, the only M. chimaera-positive sample from tap water clustered with the isolates from the HCUs of the same hospital, confirming that the plumbing system could represent the source of HCU contamination and, potentially, of patient infection. According to the genome-based phylogenies and following the classification proposed by van Ingen and collaborators in 2017, three distinct M. chimaera groups appear to have contaminated the HCU water systems: subgroups 1.1, 2.1, and branch 2. Most of the strains isolated from HCUs at the same hospital share a highly similar genetic profile. The nonrandom distribution obtained with WGS and IR-Biotyper leads to the hypothesis that M. chimaera subtypes circulating in the local plumbing colonize HCUs through the absolute filter, in addition with the current hypothesis that contamination occurs at the HCU production site. This opens the possibility that other medical equipment, such as endoscope reprocessing device or hemodialysis systems, could be contaminated by M. chimaera. IMPORTANCE Our manuscript focuses on interventions to reduce waterborne disease transmission, improve sanitation, and control infection. Sanitary water can be contaminated by nontuberculous Mycobacteria, including M. chimaera, a causative agent of invasive infections in immunocompromised patients. We found highly similar genetic and phenotypic profiles of M. chimaera isolated from heater-cooler units (HCU) used during surgery to thermo-regulate patients' body temperature, and from the same hospital tap water. These results lead to the hypothesis that M. chimaera subtypes circulating in the local plumbing colonize HCUs through the absolute filter, adding to the current hypothesis that contamination occurs at the HCU production site. In addition, this opens the possibility that other medical equipment using sanitized water, such as endoscope reprocessing devices or hemodialysis systems, could be contaminated by nontuberculous Mycobacteria, suggesting the need for environmental surveillance and associated control measures.

COVID-19 lockdown and hip arthroplasty rehabilitation changes: mid-term clinical outcomes

OBJECTIVE

Hip arthroplasty is one of the most performed surgeries in orthopedics. Rehabilitation process after surgery allows rapid recovery of joint functions in absence of pain in most patients. During COVID-19 pandemic, rehabilitation clinics have reduced the number of beds available. Thus, an increasing number of patients were forced to home rehabilitation programs. Our study aimed at determining any significant differences in clinical and functional outcomes between those patients who underwent a home rehabilitation program and those others who were granted a place in a Rehabilitation clinic during COVID-19 pandemic, at mid-term follow-up.

PATIENTS AND METHODS

An observational retrospective single-center study was designed. The patients included were 63, divided into two groups: Group A (29 patients) for home rehabilitation, and Group B (34 patients) for clinic rehabilitation. Follow-up was performed at 1, 6 and 12 months after surgery. Clinical evaluation was assessed through Oxford Hip Score for hip function, Visual Analogue Scale (VAS) for pain and hip range of motion (ROM) to evaluate joint recovery.

RESULTS

ROM was compared at follow-up with significant differences 12 months after surgery (107.93° group A vs. 104.7° group B; p=0.0168). Pain felt by patients according to the VAS scale showed no significant differences at follow-up (1 month 3.27 vs. 3.65 p=0.1489; 6 months 1.89 vs. 2.18 p=0.105; 12 months 0.58 vs. 0.68 p=0.6263). Regarding the Oxford Hip score, significant differences emerged at 1-month follow-up (38.75 group A vs. 37.94 group B; p=0.0498).

CONCLUSIONS

At mid-term follow-up, little differences were found between patients who went through home rehabilitation and those who went to a rehabilitation clinic. Therefore, decreasing the number of beds available in rehab clinics during COVID-19 pandemic was not an obstacle for elective surgery for orthopedic surgeons.

Proximal humerus fractures treatment in adult patients with bone metastasis

OBJECTIVE

The humerus is the second long bone most affected by pathological fractures. According to Capanna and Campanacci criteria, surgical choice is based on bone metastasis location, on the patient's status and on the residual functional capacity. Metadiaphysis is an area of conflict in the choice between megaprosthesis implant and intramedullary nail osteosynthesis. This study compares these two surgical procedures in terms of reacquired functionality and local control of metastasis.

PATIENTS AND METHODS

Thirty-eight patients (17 males and 21 females; mean age: 66 years old) treated in our institution between January 2010 and December 2020 for pathological humeral metadiaphyseal fractures caused by metastasis, were included in this study. We choose the Musculoskeletal Tumor Society rating system (MSTS) and the Quick Disability of Arm-Shoulder-Hand (QuickDASH) scores for the evaluation of the upper limb function after surgery.

RESULTS

Eighteen (47%) pathological fractures were treated by resection and megaprosthesis implantation, twenty (53%) were treated by medullary nail osteosynthesis. A reduction in pain and greater mechanical stability in the immediate post-operative period was found in all patients. Twenty-two patients died (58%) and sixteen survived (42%). Long-term functional recovery of patients undergoing osteosynthesis is greater than megaprothesis group.

CONCLUSIONS

Both medullary nail osteosynthesis and resection and megaprosthesis implantation guarantee excellent recovery at 72 months after surgery, improvement in quality of life and pain relief.  Patients treated with osteosynthesis showed a great short-term functional recovery since the joint portion of the limb is not involved, whereas patients treated with megaprosthesis showed better local oncologic control. It is therefore possible to define the type of treatment not only on the localization of the fracture (diaphysis or epiphysis) but above all on the conditions and characteristics of the patient.

Survivorship of proximal femoral replacement in neoplastic and non-neoplastic elderly patients

OBJECTIVE

Massive bone loss is a serious problem in the elderly. Joint replacement with modular prostheses represents the most common reconstructive technique after oncological and non-oncological resections. Megaprostheses are broadly available, adaptable and versatile and allow early mobilization and rehabilitation. Although segmental endoprosthetic implants are now widely used and despite innovations, complications remain far high. Our purpose is to establish what happens to megaprostheses of a specific anatomical site in the long term in a population with oncologic and non-oncologic indications treated at a single center solely by a few skilled surgeons.

MATERIALS AND METHODS

We retrospectively reviewed our institutional database. We collected 35 patients who underwent endoprosthetic reconstruction exclusively of the proximal femur for neoplastic and non-neoplastic disease between 2008 and 2021. The minimum follow-up was 12 months. Complications were collected and classified, and also adapted to the non-oncological setting.

RESULTS

Taking into consideration the entire population, 94% of this survived the follow-up at 6 months, subsequently 85% at 1 year and 82% at 2 years. At follow-ups after 5 years, 79% of megaprostheses showed no mechanical failure. Analyzing prosthetic survival in the two groups, this was >50% at 24 months after surgery in both groups, with better survival for the oncological one.

CONCLUSIONS

Proximal femur replacement can be a valid option in treatment of oncological and non-oncological cases. Due to the high complication rate, only selected cases should undergo this kind of surgical procedure.

Photoinduced charge separation in functional carbon-silver nanohybrids

In recent times, nanoscience is devoting growing interest to the easy assembly of well-established nanomaterials into hybrid nanostructures displaying new emerging features. Here, we study the photophysicochemical response of binary nanohybrids obtained by the spontaneous coupling of luminescent carbon dots to silver nanoparticles with controlled surface charge. Evidence of the successful coupling is obtained by steady-state and time resolved optical measurements and further confirmed by direct imaging. We demonstrate strong interactions within nanohybrids, which can be modelled in terms of a sub-picosecond electron transfer from photoexcited carbon dots to silver nanoparticles. Accordingly, newly designed nanohybrids display significant photocatalytic performance demonstrated by the photodegradation of methylene blue under ultraviolet-visible light. Our results provide an exhaustive picture of the optical response of these self-assembled carbon-silver nanohybrids and show their promise as a new class of eco-friendly materials for light-driven catalytic applications.

First report of phaeohyphomycosis caused by Phialophora americana in a domestic cat from Argentina

Case summary

A 10-year-old male neutered domestic shorthair cat from Quilmes (Province of Buenos Aires, Argentina) presented at the Infectious Diseases and Parasitology Unit with a hyperpigmented nodule of 5 cm diameter on the nasal plane with a small ulceration of more than 1 year’s evolution. A scaly and hyperpigmented alopecic lesion of 3 cm in diameter was found on the lower edge of the tail. The patient was under immunosuppressive therapy with corticosteroids for lymphoplasmacytic duodenitis. Samples of the lesion present on the nasal plane were taken under a surgical procedure. In the wet mount preparations, pigmented irregular hyphae were observed. They developed dark colonies when cultured on Sabouraud medium. On micromorphology, structures compatible with Phialophora species were identified. PCR and sequencing of ITS (ITS1-5.8S-ITS2) confirmed Phialophora americana as the etiologic agent. A therapeutic scheme that included a combination of itraconazole oral solution (1.5 mg/kg PO q12h) with terbinafine (30 mg/kg PO q24h) was indicated for a period of 10 months. The patient died of complications resulting from its underlying disease.

Relevance and novel information

As far as the authors are aware, this is the first study to report P americana as an etiologic agent of phaeohyphomycosis in cats. In this case study, the species was identified using molecular tests.

Drug Survival of IL-12/23, IL-17 and IL-23 Inhibitors for Psoriasis Treatment: A Retrospective Multi-Country, Multicentric Cohort Study

BACKGROUND

Drug survival analysis of biologic agents in psoriasis is of extreme importance, as it allows not only the evaluation of objective clinical outcomes (such as effectiveness and safety) but also of factors that are associated with patients' adherence to treatment. The aim of this study was to evaluate and compare the drug survival of the most recent biologic agents approved for the treatment of moderate-to-severe psoriasis-ustekinumab, secukinumab, ixekizumab, brodalumab, guselkumab, and risankizumab-and to identify clinical predictors that can influence the drug survival of these drugs.

METHODS

This retrospective multicentric cohort study from 16 dermatology centers in Portugal, Spain, Italy, Switzerland, Czech Republic, Canada, and the United States included patients that started IL-12/23, IL-17 (IL-17A and IL-17R) and IL-23 inhibitors for the treatment of psoriasis between January 1, 2012 and December 31, 2019. Survival analysis was performed using a Kaplan-Meier estimator, to obtain descriptive survival curves, and proportional hazard Cox regression models.

RESULTS

A total of 3312 treatment courses (total patients: 3145) were included in the study; 1118 (33.8%) with an IL-12/23 inhibitor (ustekinumab), 1678 (50.7%) with an IL-17 inhibitor [911 (27.5%) on secukinumab, 651 (19.7%) on ixekizumab, 116 (3.5%) on brodalumab], and 516 (15.5%) with an IL-23 inhibitor [398 (12.0%) on guselkumab, 118 (3.5%) on risankizumab]. At 18 months, the cumulative probability of survival was 96.4% for risankizumab, 91.1% for guselkumab, 86.3% for brodalumab, 86.1% for ustekinumab, 82.0% for ixekizumab, and 79.9% for secukinumab. Using ustekinumab as reference, drug survival of guselkumab was higher (HR 0.609; 95% CI 0.418-0.887) and that of secukinumab was lower (HR 1.490; 95% CI 1.257-1.766). In the final multivariable model, secukinumab, female sex, higher BMI, and prior exposure to biologic agents significantly increased the risk of drug discontinuation, whereas risankizumab was protective.

CONCLUSION

In this multinational cohort with 8439 patient-years of follow-up, the cumulative probability of drug survival for all drugs was >79% at 18 months. Prescribed biologic, female sex, higher BMI, and previous exposure to biologic agents were predictors of drug discontinuation. Drug survival of guselkumab and risankizumab was higher than that of ustekinumab, and secukinumab was lower.

[Clinical problems in Medical Mycology: problem number 55]

A 31-year-old woman, with signs of HIV infection (oral thrush, weight loss, asthenia) presented to our hospital with dyspnea and fever. A rapid HIV test yielded a positive result, and cryptococcal capsular antigen was detected in serum. In the mycological study of the clinical respiratory samples, yeasts compatible with Cryptococcus were observed under light microscope in a wet mount; structures compatible with Pneumocystis jirovecii were also observed in Giemsa stain. Treatment for both pathologies was prescribed but, unfortunately, the patient died 7 days after. The finding of two etiologic agents in the same clinical picture is rare but not exceptional, and it always must be considered in immunocompromised hosts.

Clinical and microbiological characteristics of paracoccidioidomycosis in patients with AIDS in Buenos Aires, Argentina

Paracoccidioidomycosis (Pm) is a systemic disease, endemic in the American continent. There are two different clinical forms, the infant-juvenile or subacute form (PmS) and the chronic adult form (PmC). The human immunodeficiency virus (HIV) associated paracoccidioidomycosis (PmHIV) shares characteristics with both of the previously mentioned forms. The objective of this work was to describe the epidemiological, clinical and laboratory features of the PmHIV and to compare them with the ones of PmS and the PmC. A retrospective analysis of 119 patients with paracoccidioidomycosis was performed. Ninety four suffered the chronic form, 11 the subacute one and 14 were coinfected with HIV. Patients with PmHIV presented a CD4+ T lymphocytes median of 70.5 cells/μl, 71.4% had fever, 64.3% had a miliary pattern on the chest radiography, 64.3% had hepatosplenomegaly, 64.3% had mucosal lesions and 50% had skin lesions. One patient died during his hospitalization. The clinical presentation of Pm in patients with HIV resembled the subacute form with fever, hepatomegaly and skin lesions. However, they also tended to present mucosal lesions, positive serology for Pm and pulmonary parenchyma lesions as usually seen in PmC (9/14 PmHIV patients had overlapping features, while 4/14 PmHIV patients clinically resembled PmS and 1/14 PmC). The incidence of Pm has not changed with the burden of AIDS as it has happened with other fungal infections but it appears clinically different from the classic clinical forms of the disease.

UV photobleaching of carbon nanodots investigated by in situ optical methods

In situ optical analysis of photobleaching unveils the real nature and evolution of emitters in a carbon-dot system.

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Antifungal Resistance in Clinical Isolates of Aspergillus spp.: When Local Epidemiology Breaks the Norm

Aspergillosis is a set of very frequent and widely distributed opportunistic diseases. Azoles are the first choice for most clinical forms. However, the distribution of azole-resistant strains is not well known around the world, especially in developing countries. The aim of our study was to determine the proportion of non-wild type strains among the clinical isolates of Aspergillus spp. To this end, the minimum inhibitory concentration of three azoles and amphotericin B (used occasionally in severe forms) was studied by broth microdilution. Unexpectedly, it was found that 8.1% of the isolates studied have a diminished susceptibility to itraconazole. This value turned out to be similar to the highest azole resistance rate reported in different countries across the world.

[Focal brain lesion due to cerebral aspergillosis in a patient with AIDS. Case report and literature review]

Cerebral aspergillosis is a rare disease with high mortality rates in AIDS patients. It is important to take this into account in the differential diagnosis of a brain expansive lesion. A high level of suspicion is required to make an early diagnosis. We present a case of an HIV-infected patient with progresive neurological disease caused by Aspergillus flavi. We review 40 previously published cases of central nervous system aspergillosis in patients with AIDS.

Arteriovenous Fistulas for Hemodialysis Created using a Long-Term Absorbable Suture: A Safe Solution and a Measure to Minimize Myointimal Hyperplasia

Background/aims

The goal of the therapeutic management of patients affected by end-stage renal disease (ESRD) is to maintain the vascular access (VA) as long as possible. Myointimal hyperplasia development in the vascular walls of arteriovenous fistulas (AVFs) is considered one of the most important factors responsible for procedure failure. These alterations could be linked to hemodynamic changes in the anastomosis and to the presence of the surgical suture itself. We report our preliminary experience, discussing the use and the possible benefits of an absorbable suture in polyglycolide trimethylene carbonate (PTC) in AVF creation.

Methods

Seventy-four AVFs were created as primary access for hemodialysis (HD), using PTC, over 4 years. Age, gender, ESRD etiology, artery and vein preoperative diameters, AVF survival outcome, and the number of AVFs created per year were recorded. The Kaplan-Meier method was used to analyze AVF survival rates.

Results

No dehiscences, pseudoaneurysms, or failures in the “critical” period related to PTC absorption were recorded. Kaplan-Meier analysis was used to evaluate AVF survival; 12-month primary AVF survival (74.33%) and AVF failure (25.67%) rates, 9 “early” (8.22%) and 10 “late” failures (13.51%), and a 360-day mean survival were found.

Conclusions

Our data indicate that PTC, a well known and widely used material for sutures in vascular surgery, is safe and effective in AVF creation. Potential advantages of PTC sutures are represented by a reduced myointimal hyperplasia formation in the AVF vascular walls, prolonging the AVF lifespan and avoiding re-interventions.

[Clinical problems in medical mycology: Problem number 51]

A 48 year-old immunocompetent woman, who had a nodular lesion in the neck and a dense infiltrate at the lower lobe of the left lung, presented at the Mycology Unit of Muñiz Hospital of Buenos Aires City. The pulmonary infiltrate disappeared spontaneously 3 months later. The histopathological study of the nodular lesion showed capsulated yeasts (mucicarmin and alcian blue positive stains) compatible with Cryptococcus. The mycological study of a new sample, obtained by a nodular puncture, allowed the isolation of yeasts, identified as Cryptococcus gattii (VGII). Latex test for Cryptococcus capsular antigen in serum was positive (1/100). CSF cultures rendered negative results. Fluconazole at a daily dose of 800mg was given during 45 days with partial improvement; as cultures from a new clinical sample were positive for Cryptococcus, the antimycotic was changed to itraconazole 400mg/day for 5 months, with an excellent clinical response.

Cryptococcosis in an Infectious Diseases Hospital of Buenos Aires, Argentina. Revision of 2041 cases: Diagnosis, clinical features and therapeutics

BACKGROUND

Cryptococcosis is still a life-threatening mycosis that continues to be of serious concern in Latin American countries, especially among HIV+positive population. However, there is not any reliable information about the prevalence of this disease in this region.

AIMS

The aim of this study is to report data of 2041 patients with cryptococcosis that were attended at the Infectious Diseases Hospital F. J. Muñiz over a 30 year-period.

METHODS

Information about demographic and clinical data, survival time and the applied treatment, was taken from the Mycology Unit database. Mycological exams from different clinical samples were performed. Cryptococcal capsular antigen in serum and cerebrospinal fluid was detected through the latex agglutination technique. Cryptococcus isolates were phenotypically identified and the genotype was determined in some of them. Susceptibility tests were carried out following M27-A3 document.

RESULTS

Seventy five percent of HIV+positive patients and 50% of the HIV-negative population were males. Mean ages were 34.1 in HIV+positive patients and 44.8 in the HIV-negative. Cryptococcosis was associated with AIDS in 98% of the cases. Meningeal compromise was seen in 90% of the patients. Although cerebrospinal fluid rendered more positive results, blood culture was the first diagnostic finding in some cases. Cryptococcal antigen showed positive results in 96.2% of the sera samples and in the 93.1% of the cerebrospinal fluid samples. Most of the isolates were Cryptococcus neoformans and belonged to genotype VNI. Minimal inhibitory concentration values were mostly below the epidemiological cutoff values.

CONCLUSIONS

We observed that thanks to a high level of clinical suspicion, early diagnosis, combined therapy and intracranial pressure control by daily lumbar punctures, the global mortality rate has markedly decreased through the years in the analyzed period.

The interaction of photoexcited carbon nanodots with metal ions disclosed down to the femtosecond scale

Fluorescent carbon nanodots are a novel family of carbon-based nanoscale materials endowed with an outstanding combination of properties that make them very appealing for applications in nanosensing, photonics, solar energy harvesting and photocatalysis. One of the remarkable properties of carbon dots is their strong sensitivity to the local environment, especially to metal ions in solution. These interactions provide a testing ground for their marked photochemical properties, highlighted by many studies, and frequently driven by charge transfer events. Here we combine several optical techniques, down to femtosecond time resolution, to understand the interplay between carbon nanodots and aqueous metal ions such as Cu²⁺ and Zn²⁺. We find that copper inhibits the fluorescence of carbon dots through static and diffusional quenching mechanisms, and our measurements allow discriminating between the two. Ultrafast optical methods are then used to address the dynamics of copper-dot complexes, wherein static quenching takes place, and unveil the underlying complexity of their photocycle. We propose an initial increase of electronic charge on the surface of the dot, upon photo-excitation, followed by a partial electron transfer to the nearby ion, with 0.2 ps and 1.9 ps time constants, and finally a very fast (≪1 ps) non-radiative electron-hole recombination which brings the system back to the ground state. Notably, we find that the electron transfer stage is governed by an ultrafast water rearrangement around photo-excited dots, pointing out the key role of solvent interactions in the photo-physics of these systems.

Evaluation of a semi-automated software program for the identification of vertebral fractures in children

AIM

To assess observer reliability and diagnostic accuracy in children, of a semi-automated six-point technique developed for vertebral fracture (VF) diagnosis in adults, which records percentage loss of vertebral body height.

MATERIALS AND METHODS

Using a semi-automated software program, five observers independently assessed T4 to L4 from the lateral spine radiographs of 137 children and adolescents for VF. A previous consensus read by three paediatric radiologists using a simplified algorithm-based qualitative technique (i.e., no software involved) served as the reference standard.

RESULTS

Of a total of 1,781 vertebrae, 1,187 (67%) were adequately visualised according to three or more observers. Interobserver agreement in vertebral readability for each vertebral level for five observers ranged from 0.05 to 0.47 (95% CI: -0.19, 0.76). Intra-observer agreement using the intraclass correlation coefficient (ICC) ranged from 0.25 to 0.61. The overall sensitivity and specificity were 18% (95% CI: 14-22) and 97% (95% CI: 97-98), respectively.

CONCLUSION

In contrast to adults, the six-point technique assessing anterior, middle, and posterior vertebral height ratios is neither satisfactorily reliable nor sensitive for VF diagnosis in children. Training of the software on paediatric images is required in order to develop a paediatric standard that incorporates not only specific vertebral body height ratios but also the age-related physiological changes in vertebral shape that occur throughout childhood.

[Efficacy of the treatment and secondary antifungal prophylaxis in AIDS-related histoplasmosis. Experience at the Francisco J. Muñiz Infectious Diseases Hospital in Buenos Aires]

BACKGROUND

Classic histoplasmosis is a systemic endemic mycosis due to Histoplasma capsulatum var. capsulatum. A significant reduction in the morbidity and mortality of AIDS-related histoplasmosis has been observed since the introduction of highly active antiretroviral therapy (HAART) and secondary antifungal prophylaxis.

AIMS

The aim of this study was to determine the current state of prognosis and treatment response of HIV-positive patients with histoplasmosis in the Francisco J. Muñiz Infectious Diseases Hospital in Buenos Aires City.

METHODS

A retrospective study was conducted using the demographic, clinical, immunological and treatment data of 80 patients suffering from AIDS-related histoplasmosis.

RESULTS

Of the 80 cases studied 65 were male, the median age was 36 years, with 73.7% of the patients being drug addicts, 82.5% of the patients was not receiving HAART at diagnosis, and 58.7% of the cases had less than 50 CD4+ cells/μl at the beginning of the treatment. The initial phase of treatment consisted of intravenous amphotericin B and/or oral itraconazole for 3 months, with 78.7% of the cases showing a good clinical response. Only 26/63 patients who were discharged from hospital continued with the follow-up of the HAART, secondary prophylaxis with itraconazole or amphotericin B. Secondary prophylaxis was stopped after more than one year of HAART if the patients were asymptomatic, had two CD₄+ cell counts greater than 150cells/μl, and undetectable viral loads. No relapses were observed during a two-year follow up after prophylaxis was stopped.

CONCLUSIONS

The treatment of histoplasmosis in HIV-positive patients was effective in 78.8% of the cases. The combination of HAART and secondary antifungal prophylaxis is safe, well tolerated, and effective. The low adherence of patients to HAART and the lack of laboratory kits for rapid histoplasmosis diagnosis should be addressed in the future. The usefulness of primary antifungal prophylaxis for cryptococcosis and histoplasmosis HIV-positive patients should be studied.

Different natures of surface electronic transitions of carbon nanoparticles

Pictorial representation of the fluorescence mechanisms proposed for carbon nanodots. Blue: tunable visible emission from surface-delocalized electronic states. Violet: UV emission from localized, quasi-molecular chromophores.

[Clinical problems in medical mycology: Problem number 50]

We present the case of a 34 year-old man, HIV-positive, who had suffered a disseminated histoplasmosis treated with amphotericin B one year before his admission. He was admitted at the Infectious Diseases Muñiz Hospital with a non-lithiasic chlolecystitis. During the clinical examination perigenital skin lesions compatible with tinea cruris, as well as proximal subungual onychomycoses of toenails, were observed. Microsporum gypseum was isolated from both types of lesions. Oral terbinafine led to a good clinical response. Treatment prescription was a big challenge in this patient because he was receiving HAART and itraconazole, and there was scarce experience in the treatment of nail infections due to M. gypseum.

Ventriculoperitoneal shunts for treating increased intracranial pressure in cryptococcal meningitis with or without ventriculomegaly

INTRODUCTION

Cryptococcosis is an opportunistic mycosis, especially in patients that are human immunodeficiency virus (HIV)-positive, and frequently involves the central nervous system.

METHODS

We assessed the potential of ventriculoperitoneal shunting (VPS) in preventing mortality due to uncontrollable intracranial hypertension (ICH) in 15 patients with acquired immunodeficiency syndrome (AIDS)-related cryptococcal meningitis.

RESULTS

After 2 weeks of antifungal therapy consisting of amphotericin B deoxycholate with or without fluconazole, patients with persistent ICH underwent VPS, despite having persistent Cryptococcus neoformans infection. In 12 patients, the uncontrollable ICH was resolved by VPS.

CONCLUSIONS

Patients with cryptococcal meningoencephalitis who have ICH must be considered for VPS even with positive cerebrospinal fluid cultures.

Importance of spin-orbit interaction for the electron spin relaxation in organic semiconductors

Despite the great interest organic spintronics has recently attracted, there is only a partial understanding of the fundamental physics behind electron spin relaxation in organic semiconductors. Mechanisms based on hyperfine interaction have been demonstrated, but the role of the spin-orbit interaction remains elusive. Here, we report muon spin spectroscopy and time-resolved photoluminescence measurements on two series of molecular semiconductors in which the strength of the spin-orbit interaction has been systematically modified with a targeted chemical substitution of different atoms at a particular molecular site. We find that the spin-orbit interaction is a significant source of electron spin relaxation in these materials.

[Clinical problems in medical mycology: Problem number 47]

A 66 year-old man, who had lived in Paraguay and was a rural worker, was admitted to Infectious Diseases Hospital F. J. Muñiz in Buenos Aires. He presented fever, loss of body weight, cough, mucopurulent expectoration, wide perianal ulceration, paresthesia and paresis of both legs as well as vesical and anal sphincter dysfunction. He was a heavy smoker and drinker. Thorax X-ray examination showed bilateral micronodular interstitial lesions. With a NMR of the dorsolumbar spine region a nodular lesion outside the spinal cord (which produced compression of this organ) was shown. The diagnosis of disseminated paracoccidiodomycosis was based on the finding of Paracoccidioides brasiliensis in the skin ulcer in histopathology and mycology studies, and on the positive results of serologic tests with paracoccidioidin antigen. The patient was treated with trimethoprim-sulfamethoxazole with good clinical outcome.