ABSTRACT
Tumor thrombus arising from osteosarcoma is rare. We report the case of a 20-year-old man with proximal humerus osteosarcoma, accompanied by an extensive intravascular tumor thrombus extending into the heart. Our review of the literature found 14 previous reports on osteosarcoma with tumor thrombus. The combination of positron emission tomography and computed tomography is very useful in differentiating tumor thrombus from vascular thrombus, thereby avoiding unnecessary anticoagulation therapy. This same imaging combination can also be used to evaluate the response to treatment. Surgical resection of the tumor thrombus is highly recommended. The effect of tumor thrombus on survival is still unknown.
Subject(s)
Bone Neoplasms/complications , Humerus/pathology , Osteosarcoma/complications , Thrombosis/etiology , Adolescent , Adult , Aged , Biopsy , Bone Neoplasms/diagnosis , Bone Neoplasms/surgery , Brachiocephalic Veins/pathology , Child , Child, Preschool , Diagnosis, Differential , Disease Progression , Female , Heart Atria/pathology , Humans , Humerus/surgery , Male , Neoplasm Invasiveness , Osteosarcoma/diagnosis , Osteosarcoma/surgery , Positron-Emission Tomography , Predictive Value of Tests , Thrombosis/diagnosis , Thrombosis/surgery , Tomography, X-Ray Computed , Treatment Outcome , Vena Cava, Superior/pathology , Young AdultSubject(s)
Cholestasis/etiology , Abnormalities, Multiple/diagnosis , Ataxia/complications , Ataxia/diagnosis , Brain/abnormalities , Cholestasis/complications , Cholestasis/diagnosis , Coloboma/complications , Coloboma/diagnosis , Diagnosis, Differential , Female , Humans , Infant , Liver Diseases/complications , Liver Diseases/diagnosis , Magnetic Resonance ImagingSubject(s)
Esophagitis/etiology , Esophagus/pathology , Keratosis/etiology , Landau-Kleffner Syndrome/complications , Vitamin A Deficiency/complications , Child , Esophagitis/drug therapy , Esophagitis/pathology , Esophagoscopy , Esophagus/drug effects , Humans , Keratosis/drug therapy , Keratosis/pathology , Male , Mucous Membrane/pathology , Vitamin A/therapeutic use , Vitamin A Deficiency/drug therapy , Vitamin A Deficiency/pathology , Vitamins/therapeutic useABSTRACT
To investigate the pre-vacuolar secretory pathway in Candida albicans, we cloned and analyzed the C. albicans homolog of the Saccharomyces cerevisiae vacuolar protein sorting gene VPS1. C. albicans VPS1 encodes a predicted 694-aa dynamin-like GTPase that is 73.3% similar to S. cerevisiae Vps1p. Plasmids bearing C. albicans VPS1 complemented the temperature-sensitive growth, abnormal class F vacuolar morphology, and carboxypeptidase missorting of a S. cerevisiae vps1 null mutant. To study VPS1 function in C. albicans, a conditional mutant strain (tetR-VPS1) was generated by deleting the first allele of VPS1 and placing the second allele under control of a tetracycline-regulatable promoter. With doxycycline, the tetR-VPS1 mutant was hyper-susceptible to sub-inhibitory concentrations of fluconazole, but not amphotericin B, 5-fluorocytosine, or non-specific osmotic stresses. The repressed tetR-VPS1 mutant was defective in filamentation and secreted less extracellular protease activity. Biofilm production and filamentation within the biofilm were markedly reduced. These results suggest that C. albicans VPS1 has a key role in several important virulence-related phenotypes.
Subject(s)
Biofilms/growth & development , Candida albicans/enzymology , Candida albicans/physiology , GTP-Binding Proteins/metabolism , Peptide Hydrolases/metabolism , Antifungal Agents/pharmacology , Candida albicans/drug effects , Candida albicans/genetics , Fungal Proteins/genetics , Fungal Proteins/metabolism , GTP-Binding Proteins/genetics , Gene Expression Regulation, Fungal , Genetic Complementation Test , Osmotic Pressure , Protein Transport , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Transcription, Genetic , Vacuoles/metabolism , Vesicular Transport ProteinsABSTRACT
Human immunodeficiency virus type 1 (HIV-1) infection is initiated by the binding of the viral envelope protein gp120 to the host cell CD4 receptor through a high-affinity interaction involving amino acids 39-60 within the CD4. We obtained evidence demonstrating functional importance of this region in CD4 for viral infectivity by showing that a synthetic peptide corresponding to this CD4 sequence exhibited competitive binding to gp120 and significantly reduced infection by diverse HIV-1 strains, including primary isolates. Treatment of HIV-1-infected cells with this CD4 peptide induced shedding of gp120 and exposure of the transmembrane protein gp41. Furthermore, we observed that deletion or substitution of arginine at position 59 (Arg(59)) within the CD4 peptide sequence abrogated its gp120-shedding property. These results indicate a critical role for Arg(59) in the CD4 for conformational changes in gp120 during the sequential process of entry and infection by HIV-1.