Renal Contrast-Enhanced Sonography Findings in a Model of Acute Cellular Allograft Rejection.

Noninvasive methods to diagnose and differentiate acute cellular rejection from acute tubular necrosis or acute calcineurin inhibitor toxicity are still missing. Because T lymphocytes play a decisive role in early states of rejection, we investigated the suitability and feasibility of antibody-mediated contrast-enhanced ultrasound by using microbubbles targeted to CD3(+) , CD4(+) , or CD8(+) T cells in different models of renal disease. In an established rat renal transplantation model, CD3-mediated ultrasound allows the detection of acute rejection as early as on postoperative day 2. Ultrasound signal intensities increased with the severity of inflammation. Further, an early response to therapy could be monitored by using contrast-enhanced sonography. Notably, acute tubular necrosis occurring after ischemia-reperfusion injury as well as acute calcineurin inhibitor toxicity could easily be differentiated. Finally, the quantified ultrasound signal correlated significantly with the number of infiltrating T cells obtained by histology and with CD3 mRNA levels, as well as with chemokine CXCL9, CXCL11, and CCL19 mRNA but not with KIM-1 mRNA expression, thereby representing the severity of graft inflammation but not the degree of kidney injury. In summary, we demonstrate that antibody-mediated contrast-enhanced ultrasound targeting T lymphocytes could be a promising tool for an easy and reproducible assessment of acute rejection after renal transplantation.

Giant cavernous malformations in young adults: report of two cases, radiological findings and surgical consequences.

Cerebral cavernous malformations, also known as cavernous angioma or cavernoma, are a type of vascular disorder. They consist of abnormally large vascular cavities or sinusoid channels of varying size. The majority of cavernous malformations in the brain are small and do not always present with symptoms. A minority of large cavernous malformations, known as giant cavernous malformations (GCM), can cause neurological symptoms (such as headaches, focal neurologic deficits and seizures), which are probably related to hemorrhage and mass effect. GCM grow steadily in size over time, due to repetitive episodes of bleeding. The purpose of this paper is to document two case reports of patients with GCM, illustrate the radiological appearance, discuss the neurosurgical consequences, and to provide a literature analysis.

Pneumosinus dilatans in anterior skull base meningiomas.

INTRODUCTION: Skull base meningiomas are often missed on non-contrast CT or MR examinations due to their close proximity to bone and low lesion to brain contrast. The purpose of this study is to illustrate that pneumosinus dilatans can be an indicator of anterior skull base meningiomas. METHODS: A retrospective search of the radiology information system and picture archiving and computing system database was performed. Search terms were "meningioma" in association with "pneumosinus dilatans." Medical records and imaging studies were reviewed independently by two experienced neuroradiologists and were read in consensus. We recorded the patient age at the time of discovery of the meningioma, main presenting symptom(s), location of the tumor, and imaging characteristics. We also performed a comparative literature search for pneumosinus dilatans and its association with meningiomas. RESULTS: Ten patients (six women; four men) were identified in whom a meningioma of the anterior skull base was associated with a pneumosinus dilatans. Three patients had multiple meningiomas, so a total of 14 intracranial tumors were identified. Mean age at discovery was 59 years with an age range of ± 20years. All meningiomas were diagnosed by MRI and/or CT. CONCLUSION: Pneumosinus dilatans can be a helpful sign to indicate the presence of a meningioma of the anterior skull base.

Medical and surgical management of paraneoplastic pyoderma gangrenosum--a case report and review of the literature.

We present a case of a 44-year-old male with pyoderma gangrenosum (PG) presenting simultaneously with diagnosis of acute leukemia. His skin disease was stabilized with corticosteroids and most lesions cleared after chemotherapy-induced remission of the malignancy, but the largest lesion remained necrotic. Surgical treatment of the large necrotic ulcer included debridement followed by split-thickness skin graft while maintaining corticoid therapy. Unfortunately, relapse of the pyoderma gangrenosum with bullous lesions heralded relapse of the ultimately fatal malignancy. This case illustrates: (1) PG presenting simultaneously with a haematologic malignancy (2) Relapse with atypical bullous lesions with return of the malignancy and (3) The use of surgical modalities in managing patients with PG, a disease notorious for surgical complications.

Stridor due to a bridge-like subglottic stenosis in a 10-week-old male infant.

We present an infant with post-intubation stridor caused by a bridge-like subglottic stenosis. At the age of 6 weeks he suffered from a RSV infection with the need for endotracheal intubation. At week 10 acute respiratory distress required a re-intubation. Flexible endoscopy was suggestive for laryngomalacia. Rigid endoscopy revealed a subglottic laterolateral mucosal bridge resulting in a doubling of the airway lumen. Histopathological examination showed a fibrinoid pseudomembrane. Follow up endoscopy showed a grade 1 posterior subglottic stenosis without respiratory compromise. This is the first case in the literature of an infant with a post-intubation bridge-like fibrinoid pseudomembranous subglottic lesion.

Influence of tangeretin on tamoxifen's therapeutic benefit in mammary cancer.

BACKGROUND: Tamoxifen and the citrus flavonoid tangeretin exhibit similar inhibitory effects on the growth and invasive properties of human mammary cancer cells in vitro; furthermore, the two agents have displayed additive effects in vitro. In this study, we examined whether tangeretin would enhance tamoxifen's therapeutic benefit in vivo. METHODS: Female nude mice (n = 80) were inoculated subcutaneously with human MCF-7/6 mammary adenocarcinoma cells. Groups of 20 mice were treated orally by adding the following substances to their drinking water: tamoxifen (3 x 10(-5) M), tangeretin (1 x 10(-4) M), tamoxifen plus tangeretin (3 x 10(-5) M plus 1 x 10(-4) M), or solvent. RESULTS AND CONCLUSIONS: Oral treatment of mice with tamoxifen resulted in a statistically significant inhibition of tumor growth compared with solvent treatment (two-sided P = .001). Treatment with tangeretin did not inhibit tumor growth, and addition of this compound to drinking water with tamoxifen completely neutralized tamoxifen's inhibitory effect. The median survival time of tumor-bearing mice treated with tamoxifen plus tangeretin was reduced in comparison with that of mice treated with tamoxifen alone (14 versus 56 weeks; two-sided P = .002). Tangeretin (1 x 10(-6) M or higher) inhibited the cytolytic effect of murine natural killer cells on MCF-7/6 cells in vitro, which may explain why tamoxifen-induced inhibition of tumor growth in mice is abolished when tangeretin is present in drinking water. IMPLICATIONS: We describe an in vivo model to study potential interference of dietary compounds, such as flavonoids, with tamoxifen, which could lead to reduced efficacy of adjuvant therapy. In our study, the tumor growth-inhibiting effect of oral tamoxifen was reversed upon addition of tangeretin to the diet. Our data argue against excessive consumption of tangeretin-added products and supplements by patients with mammary cancer during tamoxifen treatment.

Two cases of disseminated mucormycosis in patients with hematological malignancies and literature review.

Two cases of disseminated mucormycosis in patients with underlying hematological disease are described. Both patients presented with fever and pulmonary infiltrates which did not respond to empirical treatment with broad-spectrum antibiotics and antifungal agents, and in both patients there was rapid progression with a fatal outcome. All cultures were negative and the diagnosis was made postmortem. A review of the literature revealed only three recent reports of successful treatment of disseminated mucormycosis. Survival correlated with control of the underlying disease and early diagnosis based on histological examination of biopsy specimens from suspected lesions. Therapy consisted of surgical debridement and amphotericin B. Standard therapeutic schedules need to be defined for this infection.

Anti-invasive activity of alkaloids and polyphenolics in vitro.

Invasiveness, the ability of certain tumour cells to migrate beyond their natural tissue boundaries, often leads to metastasis, and usually determines the fatal outcome of cancer. The need for anti-invasive agents has led us to search for possibly active compounds among alkaloids and polyphenolics. One hundred compounds were screened in an assay based on the confrontation of invasive human MCF-7/6 mammary carcinoma cells with fragments of normal embryonic chick heart in vitro. Anti-invasive activity was frequently found among chalcones having a prenyl group. Six compounds were found to inhibit invasion when added to the culture medium at concentrations as low as 1 microM. For at least three of them the anti-invasive effect could be associated with a cytotoxic effect on the MCF-7/6 cells, but not on the heart tissue. This selective cytotoxicity was substantiated by different methods, such as histology and growth assays (volume measurements, cell counts, MTT and sulforhodamine B assays). The anti-invasive effects of the compounds could neither be ascribed to induction of apoptosis nor to the promotion of cell-cell adhesion. Our data indicate that among the alkaloids and polyphenolics a number of molecules can inhibit growth and invasion of human mammary cancer cells via selective cytotoxicity.

Functional downregulation of the E-cadherin/catenin complex leads to loss of contact inhibition of motility and of mitochondrial activity, but not of growth in confluent epithelial cell cultures.

When epithelial cells reach confluency in vitro, a number of energy-requiring activities such as growth and motility are contact-inhibited. We investigated the possible role of the E-cadherin/catenin complex, which acts as an invasion suppressor, in contact inhibition. Three strategies for modulation of the complex were used. Firstly, the cell-cell adhesion and signal transduction functions of E-cadherin were neutralized immunologically in human MCF-7/6 mammary carcinoma cells possessing a complete complex. Secondly, the effect of E-cadherin transfection in E-cadherin negative cell lines was investigated. Thirdly, alpha-catenin deficient variants of the human HCT-8/S11 colon carcinoma cell line were compared with their parent cells. In confluent cultures functional downregulation of the E-cadherin/catenin complex did not alter cell growth nor saturation density. This was shown by cell number counts, protein staining assays, cell cycle analysis, proliferation markers (Ki67 and Proliferating Cell Nuclear Antigen) and apoptosis assays. However, confluent cells with a functionally deficient complex showed positional instability and enhanced succinate dehydrogenase-mediated mitochondrial 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl) tetrazolium bromide (MTT) conversion, as compared to cells with an active complex. Our data indicate that contact inhibition of motility and of mitochondrial enzyme activity, but not of growth is regulated by the E-cadherin/catenin complex in epithelial cells.

Regulation of the invasion suppressor function of the cadherin/catenin complex.

Invasion is the cause of cancer malignancy. Invasion results from the cross-talk between cancer cells and host cells, building molecular invasion-promoter and invasion-suppressor complexes. The E-cadherin/catenin invasion-suppressor complex is regulated multifactorially, at multiple levels and sometimes in a reversible way. Mutations in the E-cadherin gene combined with loss of the wild type allele, causing irreversible downregulation, has been demonstrated only in a minority of human cancers. Posttranslational and reversible downregulation has been ascribed to tyrosine phosphorylation of beta-catenin. Phosphorylation is also implicated in transmembrane receptor signal transduction through the E-cadherin/catenin complex. E-cadherin interacts with E-cadherin on another cell through a dimeric adhesion zipper, involving the histidine-alanine-valine (HAV) sequence of the first extracellular domains. This is the major extracellular like of the E-cadherin/catenin complex, though not the only one. Intracellularly, the list of proteins that bind to or signal through the complex or through one or more of its elements is steadily growing. Extrinsic factors may influence the complex. At least in vitro, insulin-like growth factor-I, retinoic acid, tangeretin and tamoxifen were shown to upregulate the functions of the E-cadherin/catenin complex including inhibition of invasion.