Detection of linezolid resistance due to the optrA gene in Enterococcus faecalis from poultry meat from the American continent (Colombia).

Background: Three Enterococcus isolates obtained from retail chicken collected in 2010-11 as part of the Colombian Integrated Program for Antimicrobial Resistance Surveillance (COIPARS) showed reduced susceptibility towards linezolid (MIC 8 mg/L). Objectives: This study aimed at characterizing the isolates resistant to linezolid and detecting the resistance mechanism. Methods: Strains were analysed in 2011-12 without successful detection of the resistance mechanism. All isolates were found negative for the cfr gene and no 23S rRNA mutations were detected. In 2016, with the novel resistance gene optrA being described, the WGS data were re-analysed using in silico genomic tools for confirmation of species, detection of virulence and resistance genes, MLST and SNP analyses and comparison of the genetic environment with the previously published plasmid pE349. Results: : Three Enterococcus faecalis isolates were found positive for the optrA gene encoding resistance to linezolid and phenicols. Additional screening of 37 enterococci strains from the same study did not detect any further positives. Typing showed that two of the isolates belong to ST59, while the last belongs to ST489. All isolates carry genes encoding resistance to macrolide-lincosamide-streptogramin B, tetracycline and phenicols. In addition, the ST489 isolate also carries genes conferring aminoglycoside resistance and is resistant to quinolones, but no plasmid-mediated gene was detected. The optrA gene regions of the three plasmids showed high similarity to the originally reported optrA -carrying plasmid pE349. Conclusions: To the best of our knowledge, this is the first description of the optrA gene in E. faecalis isolated from poultry meat in the Americas.

Cutaneous infection with Alternaria triticina in a Bilateral lung transplant recipient.

We report the case of a 60-year-old man who was receiving immunosuppressive therapy for a bilateral lung transplant and presented with a crusted, violaceous plaque on the left hand. Based on histopathology and microbiological culture the patient was diagnosed with infection by Alternaria species. Treatment with itraconazole led to complete resolution of the skin lesion. Forty months later he developed four reddish, nodular, skin lesions on the left leg. Analysis of a biopsy from one of these lesions using histopathologic and molecular techniques identified a mold that shared 98% homology with a strain of Alternaria triticina. Alternaria species belong to a group of dematiaceous fungi that cause opportunistic infections in humans. The incidence of these infections is increasing, mainly in transplant centers. To the best of our knowledge, this is the first reported case of a human infection caused by A. triticina.

Development and validation of I-DNA1: a 15-Loci multiplex system for identity testing.

This paper presents a system for the multiplex amplification of 15 loci, known as I-DNA1, which combines mini and midiSTR technology, with amplicon sizes ranging from 49 to 297 bp. I-DNA1 analyses all the STR loci included in the CODIS and the Interpol Standard Set of loci, nine of the ten European core loci and seven of the eight German core loci, making it suitable for use in identifying humans. Moreover, its high sensitivity and the small size of its amplicons mean that I-DNA1 is potentially highly useful for analysing highly degraded and/or very small DNA samples.

Generalized granuloma annulare and giant cell arteritis.

Granuloma annulare (Gan) and giant cell arteritis (GCA) share common histologic features. In Gan, a disease characterized by the presence of palisading granulomas usually in the dermis, the main alteration is the presence of elastic fiber degeneration and it strongly suggests that the primary target leading to the development of this disorder is the injury to the elastic tissue. On the other hand, in giant cell arteritis (GCA), a vasculitis involving large-and middle-sized blood vessels, the main histologic features are the disruption of the internal elastic lamina and the nonsuppurative granulomatous giant cell infiltrate, which seems to be focused around the disintegrated elastic fibers. Due to this, these two conditions appear to be related. However, to the best of our knowledge, only one case of association of generalized Gan and GCA is described in the literature. We herein report a new case of generalized Gan in a patient previously diagnosed with biopsy-proven GCA. Both diseases were successfully treated by oral prednisone. Although the etiology of generalized Gan and GCA remains still unknown, they seem to be immunologically mediated conditions showing predominance of T-cells in the inflammatory infiltrate.

Sclerotic fibroma-like dermatofibroma: an uncommon distinctive variant of dermatofibroma.

Dermatofibroma (DF) is a common benign cutaneous tumor with many variants based on alterations in the morphology and composition of its diverse elements. One very infrequent type is sclerotic fibroma-like DF (SF-DF). We report 7 new cases of SF-DF. In addition, their main clinicopathological and immunohistochemical features were compared with 14 unselected common DFs and with 3 sclerotic fibromas (SFs). Microscopically, the 7 cases of SF-DFs showed an unencapsulated, well-circumscribed, hypocellular central nodule with thick collagen bundles arranged in a storiform pattern with prominent clefts. The overlying epidermis was attenuated. The periphery of this nodule was more cellular with histopathologic features of common DF. The 7 SF-DFs patients were 4 women and 3 men with a mean (+/-SD) age of 44.8 (+/-15.5) years. These 7 patients were younger than those suffering from SFs [71.0 (+/-17.3) years; (p=0.04)] and older than those presenting common DFs [30.5 (+/-12.3) years; (p=0.03)]. Immunohistochemically, spindle cells in all 7 SF-DFs were negative for CD34 and CD99. On the contrary, the 3 cases of SF were positive for CD34 and CD99. All of the common DFs were negative for CD34 and only 4 (28.6%) of them were positive for CD99. In conclusion, SF-DF is an uncommon variant of DF with similar clinicopathological and immunohistochemical features. SF-DF shares certain histopathologic features with SF but they are immunophenotypically different. Therefore, both entities should be differentiated.

Markers of fibrosis in early biopsies of renal transplants.

Many factors are involved in the development of chronic allograft nephropathy (CAN). Extracellular matrix turnover depends on the balance between fibrogenic and antifibrogenic cytokines. The aim of our study was to analyze the presence of transforming growth factor beta-1 (TGF-beta1), matrix metalloproteinase-2 (MMP-2), and mast cells in 53 early transplant biopsies using immunochemistry with specific monoclonal antibodies. We divided the patients into two groups depending on graft evolution (lost due to CAN versus functioning), renal function, presence of proteinuria, and graft survival. There were no differences in the demographic or immunological data. Renal function was worse and proteinuria greater among the group with CAN. The presence of mast cells was similar in both groups, but TGF-beta1 was expressed more and MMP-2 less in the CAN group. We observed a negative correlation between donor age and mast cells, and a positive correlation between TGF-beta1 and MMP-2. Grafts from younger donors showed better renal function, less proteinuria, greater graft survival, and less frequent development of CAN. According to our experience, cytokines involved in matrix turnover are expressed in early stages, correlating with donor age. The expressions of TGF-beta1 and MMP-2 seem to be important for the development of fibrosis in CAN.

[Microscopic polyangiitis in a patient with rheumatoid arthritis]. / Poliangeítis microscópica en paciente con artritis reumatoide.

Rheumatoid arthritis (RA) is a systemic disorder that primary involves joints, although renal disease has also been associated it is not common that rapidly progressive glomerulonephritis (RPGN) appears. We report the case of a patient with nodular and aggressive RA who had an acut renal failure secondary to ANCA positive RPGN due to a Microscopic polyangiitis who was not responsive to steroids and cyclophosphamide therapy.

Pagetoid dyskeratosis of the cervix: an incidental histologic finding in uterine prolapse.

Pagetoid dyskeratosis, is considered a reactive process in which a small part of the normal population of keratinocytes is induced to proliferate. The lesion is characterized by pale cells resembling those of Paget's disease within the epidermis. These cells have been seen as an incidental finding in a variety of benign papules most commonly located in intertriginous areas. Among the inductors of the lesion, friction is suspected. To the best of our knowledge, these pale cells have not been reported in the cervix. We describe the location of the lesion in the ectocervix and the incidence of this lesion in a group of 100 unselected patients surgically treated for uterine prolapse. Another group of 100 unselected patients treated for uterine leiomyoma was used as a control. Pagetoid dyskeratosis was found in 37 cases (37%) of uterine prolapse and in five cases (5%) of uterine leiomyomas. The lesion is more common in uterine prolapse (p <0.001) and is not significantly associated with cornification of the epithelium (p = 0.72343). The cells of pagetoid dyskeratosis show an immunohistochemical profile different from the surrounding squamous cells characterized by premature keratinization. Pagetoid dyskeratosis cells have shown positivity for high molecular weight cytokeratin and negative reaction for low molecular weight cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and human papilloma virus. Pagetoid dyskeratosis cells must be distinguished from artefactual clear cells, glycogen-rich cells, koilocytes, extramammary Paget's disease cells, and pagetoid spread of carcinoma cells to the cervix. In cases in which pagetoid dyskeratosis shows a florid expression, there is a hazard of overdiagnosis. The pathologist should be aware of the histologic features of pagetoid dyskeratosis in the ectocervix to avoid misdiagnosis and unnecessary treatment. Routine histologic study is usually sufficient to identify the lesion.

Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor).

The presence of human herpesvirus-8 DNA sequences, as well as an overexpression of human interleukin-6 and human cyclin D1 in myofibroblastic cells of inflammatory myofibroblastic tumor (inflammatory pseudotumor), has recently been reported. We describe the pattern of human herpesvirus-8 gene expression in five cases of pulmonary inflammatory myofibroblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR), with several positive and negative controls, was performed to detect mRNA of 11 open reading frames encoded by human herpesvirus-8 in lytic and latent stages of viral replicative cycle. We found molecular transcripts from ORF16, ORFK13, and ORF72 in the five cases and from ORFK2 in four of five neoplasms. The corresponding encoded proteins were human homologous oncoproteins (viral cyclin-D), inflammatory cytokines (viral IL-6), and inhibitors of apoptotic pathways (viral FLIP and viral Bcl-2), mostly expressed in a latent viral replicative stage. The rest of open reading frames examined included mainly lytic-associated genes and showed no expression. The spectrum of expressed viral genes is not the same as can be observed in Kaposi's sarcoma or multicentric Castleman's disease, suggesting that human herpesvirus-8 plays a different role in the pathogenesis of its associated diseases. These differences may be related to either cell-specific or immunologic host factors.

Telomerase activity in pulmonary neuroendocrine tumors: correlation with histologic subtype (MS-0060).

The authors measured telomerase activity using the telomeric repeat amplification protocol-enzyme-linked immunosorbent assay method in 13 neuroendocrine pulmonary neoplasms and in non-neoplastic frozen lung samples from the same patients. These cases belonged to the complete neuroendocrine neoplastic spectrum: four typical carcinoids, three atypical carcinoids, four large cell neuroendocrine lung carcinomas, and two small cell lung carcinomas. The authors performed the same assay for 52 non-neoplastic lung tissues from the surgical files in their department (negative controls). They verified the presence (or absence) of neoplastic tissue in every case by looking at one frozen section done in the same tissue used for telomerase assay. The telomerase activity level in non-neoplastic tissues (mean, 182 A450nm U) was similar to that obtained in the typical carcinoids (mean, 104.5 A450nm U). All neuroendocrine tumors but the typical carcinoids showed high levels of telomerase activity (mean, 1,750.8 A450nm U). According to the telomerase hypothesis, typical carcinoid cells are mortal pre-M2 stage cells, but atypical carcinoid, large cell neuroendocrine lung carcinoma, and small cell lung carcinoma cells are immortal post-M2 stage cells. This finding may be of important prognostic significance in these kinds of tumors. Measurement of enzyme activity with a good morphologic control could be necessary in telomerase activity assay.

Thrombomodulin, calretinin and c-kit (CD117) expression in cardiac myxoma.

The immunohistochemical profile of cardiac myxoma has been debated. The tumor is thought to be derived from multipotential undifferentiated mesenchymal cells. A consistent marker for this tumor has not been found. In this article an immunohistochemical study of 23 cardiac myxomas was accomplished. This study comprised the immunoreactivity of the tumors for thrombomodulin, calretinin and and c-kit (CD117). To the best of our knowledge, thrombomodulin and c-kit have not been tested in cardiac myxoma. Calretinin expression has been recently demonstrated in cardiac myxoma, although this finding has not been yet validated. Surface lining cells, tumor vascular endothelium, cells around the vascular slits and stromal cells embedded in the myxoid matrix were assessed independently. All tumors showed reactivity for thrombomodulin in the surface cells and in the endothelium of neoplastic vessels. 82.6% of cardiac myxomas expressed thrombomodulin in the stromal cells and 69.6% of the tumors were reactive in the perivascular cells. 73.9% of cardiac myxomas expressed calretinin in the stromal cells and in the perivascular cells. All myxomas were negative for c-kit. Thrombomodulin and calretinin may be important diagnostic aids for cardiac myxoma. Cardiac myxoma cells do not express embryonic/fetal endothelial antigens.

Selective nuclear morphometry as a prognostic factor of survival in renal cell carcinoma.

In the present study, we sought to determine the predictive value of selective nuclear morphometry (SNM) for patient outcome in renal cell carcinoma (RCC). Tumor samples of 140 renal adenocarcinomas diagnosed and treated with radical nephrectomy and hilar lymphadenectomy between 1970 and 1988 with a minimum follow up of 5 years in all the cases were studied by SNM. The morphometric analysis was performed in the most malignant tumor selected zone. Selection was based on cytological criteria including nuclear grade. Nuclear morphometric features analyzed were: area, perimeter, major diameter, major and minor diameter of the equivalent ellipse, volume of the equivalent ellipse and sphere, circumference diameter, and shape factors. The results showed that in the selected zone tumor nuclei were larger than in the zones selected at random. There was an inverse correlation between morphometric parameters and survival and a direct one between tumoral grade and stage. Tumors of the long-term survival group of patients presented nuclei with smaller morphometric measurements than tumors of short term survival group, with significant differences between them (p < 0.05). In the survival analysis carried out by the Kaplan-Meier method significant differences existed between different groups formed from break point for: area, perimeter, major diameter, major and minor diameter of the ellipse, volume of the ellipse and sphere, circumference diameter and perimeter shape factor. In the multivariate analysis carried out by the Cox method, the feature with the most predictable value related to survival, was the tumor stage. Morphometric value with the highest punctuation in the test was major nuclear diameter. The rest of the morphometric values (except elliptic shape factor and elongation factor) were also significant but they did not improve prognostic information of the major nuclear diameter. SNM offers a useful aid in a more objective grading of RCC. Multivariate Cox analysis revealed additional value of karyometry to tumor stage. SNM can be a useful tool for stratification of patients with RCC.

Papillary adenoma of the kidney with mucinous secretion.

Although infrequently, mucin secretion has previously been reported in papillary renal cell carcinoma. We here investigate the presence of mucin in a series of 93 renal papillary adenomas in 58 patients. Acid mucin was present in four cases (4.3% of the tumors; 6.9% of the patients), in which basophilic mucin secretion was evident with hematoxylin-eosin. To the best of our knowledge mucin secretion has not been reported in renal papillary adenoma. We describe two different types of mucin secretion: intracytoplasmic and luminal. The secretion was intracellular in numerous scattered tumor cells in two cases, focal luminal in one case, and mixed intracellular and luminal in another case. Mucin production, despite its low frequency, can be considered as an additional feature of renal papillary adenoma. Mucin production suggests that renal papillary adenoma and papillary renal cell carcinoma are actually not two independent biological processes, but a continuum of one biological process.

MIB1 proliferation index in breast infiltrating carcinoma: comparison with other proliferative markers and association with new biological prognostic factors.

AIMS: In breast invasive carcinoma our objectives were I) to compare cellular proliferation determined by MIB1 index with S-phase fraction (SPF) assessed by flow cytometry and with mitotic index, and II) to examine the association of MIB1 index with classical and with new biological prognostic factors [bcl-2, p53, c-erbB-2 and cathepsin D (CD)]. METHODS AND RESULTS: From 102 cases of breast invasive carcinoma, 5-microm thick serial sections were cut from formalin-fixed, paraffin-embedded tissue blocks, and processed for detection of CD, c-erbB-2, p53, bcl-2, Ki-67 antigen MIB-1 and estrogen receptors (ER) and progesterone receptors (PR). SPF was measured by flow cytometry in fresh-frozen tissue samples taken from the carcinoma in each patient. MIB1 index was correlated with SPF (rho=0.45, p<0.0001) and with mitotic index (rho=0.42, p<0.0001). The MIB-1 index was positively associated with the histological grade (p=0.001), tumor size (p=0.04) and the presence of metastases in axillary lymph nodes (p=0.01). MIB1 was associated directly with p53 (p=0.045) and inversely with bcl-2 (p=0.0002). The MIB-1 index was not statistically associated with c-erbB-2. There was a weak association between MIBI index and stromal cell CD. The median MIB1 index was higher in tumors with moderate to strong CD staining of stromal cell, but the difference did not reach statistical significance (p=0.09). CONCLUSIONS: MIB1 index correlates with well established methods for assessing tumor proliferation and with parameters of an aggressive phenotype of tumor. MIB1 index is an effective and readily accessible method for assessing tumor proliferation in breast carcinoma.

Argyrophilic nucleolar organizer region (AgNOR) counting in astrocytic gliomas: prognostic value.

In 87 astrocytic gliomas the number of AgNORs/nucleus was retrospectively studied and data correlated with the histological type of the tumors and survival. All patients were treated by the same surgical team and with uniform criteria. Statistically significant differences (p < 0.01) were found in relation with the AgNOR averages among the histological types of tumors. A statistically significant linear correlation (p < 0.05) between the AgNOR values and survival of the patients was also found. Patients with mean AgNOR values higher than 2.23 and lower than 2.9 survived an average of 11.5 +/- 9.1 months vs. a survival in average of 24.4 +/- 34.1 months with mean AgNOR values under 2.23 (p < 0.05). Patients with AgNOR values higher than 2.9 survived, on average, 7.7 +/- 3.9 months. AgNOR counting in astrocytic gliomas is a reproducible, easy, quick method with prognostic value. AgNORs may be successfully applied in routine material to assess the growth potential of astrocytic gliomas.

Helicobacter pylori in Barrett's esophagus.

Barrett's esophagus is an anatomicoclinical state in which, due to the prolonged action of gastroesophageal reflux, the squamous epithelium is replaced by columnar epithelium. Helicobacter pylori has been implicated in the pathogenesis of various gastrointestinal disorders and has occasionally been observed in Barrett's esophagus. The aim of this study is to determine the incidence of H. pylori in Barrett's esophagus and try to establish its role in the pathogenesis of this disorder. H. pylori was observed in 31 biopsies (44.3%) of the 70 studied, mainly when the epithelium is of the gastric atrophic-fundic type (p less than 0.01). Its presence shows no relation to the degree of inflammatory activity and does not seem, therefore, to play an important role in the pathogenesis of the lesion.

Prognostic analysis of astrocytic gliomas correlating histological parameters with the proliferating cell nuclear antigen labelling index (PCNA-LI).

Eighty out of 250 cases of astrocytic glioma collected from a practice served by a single clinical team over a 15-year period were studied using a full complement of clinical, follow up, histopathological analysis and proliferating cell nuclear antigen (PCNA) immunostaining for the obtention of the PCNA-labelling index (LI). A statistical evaluation and discriminant analysis were carried out with the aim of clarifying the importance of various parameters as predictors of tumor behaviour. Data are correlated with survival (with a 10-year follow up). A significant correlation with survival was found when histological grouping and the PCNA-LI were studied with the Cox test. Most significant features were histological as detected using classical techniques including histological grading. The utilization of objective values (mitosis, cellular density and necrosis) appears to be useful in grading astrocytic tumors. Our results emphasize the importance of cytological, histological and PCNA-LI parameters as predictors of tumor behaviour.

Symptomatic solitary right renal vein aneurysm: a case report.

Renal vein aneurysms are very uncommon. Those located in the right side are exceptional. A symptomatic, solitary, voluminous aneurysm of the right renal vein in a 33-year-old man is reported. The lesion was diagnosed preoperatively as a renal tumor. The pathologic study of the nephrectomy specimen disclosed a thrombosed saccular aneurysm measuring 5.5 cm with marked medial atrophy of its wall. Recognition that a mass like this reported is of vascular origin is very important to avoid percutaneous biopsy which could be potentially hazardous; and for undertaking conservative prophylactic surgery. Renal venography is indicated for the diagnosis of these lesions.

Polypoid (pedunculated) subepicardial lipoma: a cardiac lesion resembling the epiploic appendage.

This report describes a 75-year-old woman with an asymptomatic pedunculated lipoma involving the epicardium of the right atrium. The lipoma was an incidental finding at autopsy. The twisted lesion showed many similarities with the infarcted epiploic appendages observed in the visceral peritoneum.