Biomedical subjects

L Rodero

Publications and source records attributed to L Rodero.

26 records · Page 2Linked to original sources

PubMedDate not supplied

[Malassezia species isolated from skin diseases in a care center in the city of Buenos Aires, Argentina].

The epidemiology of Malassezia genus is poorly understood; geographical and population factors might have influence on the species distribution. The aim of this work was to determine the frequency of Malassezia species involved in skin diseases in a diagnostic center at Buenos Aires City. From 02/01/1999 to 10/31/2001, 456 skin specimens from 447 patients diagnosed as pityriasis versicolor, seborrheic dermatitis, foliculitis and atopic dermatitis, were analyzed by microscopic examination and culture. Malassezia spp was evidenced in 255 skin samples (55.9%) by microscopic analysis but it could be recovered from only 99 (38.8%) specimens. Malassezia species were isolated from 10 (3.9%) scarring lesions that were negative by microscopy. Among 109 isolates, M. sympodialis (58.7%) was the most frequent, followed by M. globosa and M. furfur (18.3% and 9.2%). Unique isolates (0.9%) of M. obtusa, M. slooffiae and M. restricta were recovered. Eleven isolates (10.1%) could not be identified because they had lost viability in the culture. This is the first study on Malassezia species associated to skin diseases in Argentina; further screening including other geographic regions of the country is necessary in order to confirm these results.

Adolescent↗

PubMedDate not supplied

[Buttock mass and malignant sciatic nerve tumor].

Malignant peripheral nerve sheath tumors (MPNST) are rare. We report a case of a MPNST of the proximal sciatic nerve in the thigh, unassociated with pre-existing type 1 neurofibromatosis or history of radiation therapy. A 71-year-old man had a 6 month history of constant, severe, burning pain affecting the sole of the left foot. One month after the onset, the pain radiated to the left calf, posterior aspect of the thigh and buttock, and distal leg weakness followed. Three months prior to admission, the patient developed a large and painful mass in the buttock, that occupied the entire left gluteal region on examination. There was severe weakness of ankle and toe dorsiflexion and plantarflexion, decreased sensation on the lateral and posterior aspect of the left leg as well as on the dorsal and plantar surfaces of the foot, and absent ankle jerk. EMG showed denervation and motor unit loss in the short head of biceps femoris and muscles supplied by tibial and peroneal nerves on the left side. Magnetic resonance imaging revealed a 10-cm enhancing mass of the left sciatic nerve from the upper thigh to the greater sciatic notch. In surgery, a large MPNST with a high Ki67 labeling index (> 60 %) was subtotally removed from the sciatic nerve, and adjuvant radiation therapy was administered. In the ensuing months the tumor invaded the entire pelvic region. A high sciatic malignant tumor can present with a rapidly growing buttock mass and unilateral, neuropathic foot pain imitating the tarsal tunnel syndrome.

Aged↗

PubMedDate not supplied

[Immunodiagnosis of endemic mycoses and bronchopulmonary aspergillosis: a multicenter study in Argentina].

In order to contribute to the knowledge of the relative frequency of chronic fungal diseases and assess the performance of diagnostic laboratories in Argentina, a multicenter study was performed with the participation of 25 medical centers located in 12 different provinces and Buenos Aires City. Between 04-01-2000 and 03-30-2001, 965 serum specimens from patients clinically suspected of having histoplasmosis (HP), paracoccidioidomycosis (PCM), coccidioidomycosis (CM) or aspergilosis were analyzed. Agar immunodiffusion tests (IDD) were done locally. All positive and 35% of negative sera were retested in the reference center. Results of laboratories of origin showed 98.8% concordance with those of reference center. Antibodies against any of the etiological agents were detected in 120 specimens from 98 patients. Endemic mycoses (HP, PCM and CM) were diagnosed in 70 patients (71.4%) and aspergilosis in 28 (28.6%). The frequencies of the different mycoses in decreasing order were PCM 47 patients (47.9%), aspergilosis 28 patients (28.6%), HP 13 patients (13.3%) and CM 10 patients (10.2%). The study was carried out on a voluntary basis and some areas of the country were not represented. However, the frequencies were in range with the expected rates in the population under study.

Argentina↗

PubMedDate not supplied

[Multicenter study of fungemia due to yeasts in Argentina].

The incidence of candidemia has increased approximately 500% in high-complexity hospitals. A change in the spectrum of Candida infections due to species other than Candida albicans has also been detected. Between April 1999 and April 2000 a multicenter study was performed in order to determine the species distribution associated to candidemias in Argentina and the susceptibility profile of the isolates to the current antifungal drugs. Thirty six institutions have participated. All the 265 yeast strains isolated from blood cultures were identified by morphological, physiological, and biochemical tests. The antifungal susceptibility testing of isolates was performed based on the reference NCCLS procedure. The distribution of species was: Candida albicans (40.75%), Candida parapsilosis (28.67%), Candida tropicalis (15.84%), Candida famata (3.77%), Cryptococcus neoformans (3.77%), Candida glabrata (2.64%), and others (4.53%). Most of the isolates were susceptible to amphotericin B, fluconazole and itraconazole. Mortality associated to the fungemia by yeasts episodes (n=265) was 30%, lower than results previously determined (33-54%). The mortality percentage in patients who received antifungal therapy versus patients without treatment was 26.3% and 47%, respectively.

Amphotericin B↗

PubMedDate not supplied

[Disk diffusion method for fluconazole susceptibility testing of Candida spp. isolates].

In order to standardize and evaluate a disk diffusion method with visual reading to detect in vitro fluconazole susceptibility of yeast, 1193 clinical isolates were tested. These included 584 Candida albicans, 196 Candida parapsilosis, 200 Candida tropicalis, 113 Candida glabrata, 50 Candida krusei and 50 Candida spp. and other opportunistic yeasts. The disks were manufactured in the INEI-ANLIS "Dr. Carlos G. Malbrán. The disk diffusion method results were compared to MIC results obtained by the reference CLSI M27-A2 broth microdilution method modified by EUCAST. The interpretative breakpoints for in vitro susceptibility testing of fluconazole were established at: zone diameter > or =16 mm for MIC < or =8 microg/ml (susceptible isolates), between 9 and 15 mm for MIC = 16-32 microg/ml (susceptible dose-dependent isolates), and < or =8 mm for MIC > or =64 microg/ml (resistant isolates). Overall agreement between the two methods was 94.7%, with 0.2% very major errors, and 0.3% major errors. Inter - and intralaboratory agreement was good. The disk diffusion method for drug susceptibility testing of Candida spp. isolates is inexpensive, reliable and reproducible. However, when the inhibition zone diameter is < or =15 mm, it is advisable to test the isolate by the reference microdilution method.

Antifungal Agents↗

PubMedDate not supplied

[Yeast infections: causative agents and their antifungal resistance in hospitalized pediatric patients and HIV-positive adults].

Candidiasis has increased its frequency over the last decade, particularly among hospitalized patients where it is accompanied with high rates of mortality, and in patients with AIDS who are predisposed to oropharyngeal or esophageal candidiasis. The aim of this study was to determine the frequency of appearance of different yeast species and the resistance profile to current antifungal drugs in hospitalized pediatric patients and adult HIV patients from 5 institutions of Buenos Aires City and suburbs, and La Plata City, during the period 1993-1995, in order to obtain local and updated information. Candida albicans was the etiologic agent recovered in 87% of the 214 HIV positive patients with oropharyngeal candidosis, and in 50% of the 209 hospitalized pediatric patients. In the latter group 28% of these infections were due to Candida parapsilosis and 18% to Candida tropicalis, but only 2% and 4% of oral candidosis were caused by these organisms. Detection of Malassezia furfur and Hansenula anomala, responsible of systemic infections, and Trichosporon beigelii, isolated from a burn patient, were considered remarkable since these organisms appear to be emerging pathogens. Azole resistant species as Candida krusei and C. glabrata were mostly recovered from HIV positive patients, exposed to fluconazole treatment. A very low number of amfotericin B "resistant" yeasts (n = 9) were observed in both groups. However, resistance to azole drugs, particularly to fluconazole, was found in pediatric patients (13%) and in HIV infected adults (34%).

AIDS-Related Opportunistic Infections↗

PubMedDate not supplied

[Candida dubliniensis: 1st isolation in Argentina].

We report the first isolation of Candida dubliniensis in Argentina. This strain was isolated from an oral lesion of an adult patient with AIDS during one recurrent episode of a previously treated oropharingeal candidosis. Phenotypic and genotypic characteristics coincided with those described by Sullivan et al., who was the first to study this new species.

AIDS-Related Opportunistic Infections↗

PubMedDate not supplied

[Specific fungal antisera production in rabbits].

A method for fungic antisera production against Aspergillus fumigatus, Histoplasma capsulatum, Paracoccidioides brasiliensis and Coccidioides immitis in rabbits was evaluated. Intradermic via and antigen in the dilution used for routine tests (UD) were employed to produce positive control serum for immunodiffusion test in agar gel. A. fumigatus, H. capsulatum and C. immitis antigens were prepared as described in CDC's Procedure Manual, P. brasiliensis antigen was prepared as previously described by Pires de Camargo. All rabbits produced antibodies against the different specific antigens in the primary response peak and after each booster. The titer obtained in secondary response was similar or smaller than the primary response in all cases. However, bands of similar quality and intensity were obtained by immunoprecipitation in agar gel tests. Although the antibody titers proved to be similar, higher or lower concentration of antigen used in the primary immunization produced fewer and smeared bands, respectively. This effect was evaluated in A. fumigatus only. Specific antisera production with this method proved to be easy and yielded high quality antisera. The major advantages of this method are: a) reduced number of inoculations, b) fast and simple standardisation of the antigen needed, c) equally useful for all the fungal species used so far. Therefore we strongly recommend this method.

Animals↗