ABSTRACT
The plastid DNA of Neospora caninum encodes a homologue of the rpoB gene, which is believed to encode a subunit of a bacterial or chloroplast-like RNA polymerase. The predicted protein product of the N. caninum rpoB gene has three in-frame UGA codons which appear to encode tryptophan residues rather than act as stop codons. Based on the nucleotide sequence of a portion of the ssrRNA gene of the N. caninum plastid, a model for suppression of UGA termination in this plastid is presented.
Subject(s)
DNA, Protozoan/genetics , DNA-Directed RNA Polymerases/genetics , Genes, rRNA/genetics , Neospora/genetics , Plastids/genetics , Amino Acid Sequence , Animals , Codon , DNA-Directed RNA Polymerases/chemistry , Genes, Protozoan , Molecular Sequence Data , Neospora/enzymology , Nucleic Acid Conformation , Plasmodium falciparum/genetics , Sequence Analysis, DNAABSTRACT
It is well established that the vacuole plays an important role in the cellular adaptation to growth in the presence of elevated extracellular Ca2+ concentrations in Saccharomyces cerevisiae. The Ca2+ ATPase Pmc1p and the Ca2+/H+ exchanger Vcx1p/Hum1p have been shown to facilitate Ca2+ sequestration into the vacuole. However, the distinct physiological roles of these two vacuolar Ca2+ transporters remain uncertain. Here we show that Vcx1p can rapidly sequester a sudden pulse of cytosolic Ca2+ into the vacuole, while Pmc1p carries out this function much less efficiently. This finding is consistent with the postulated role of Vcx1p as a high capacity, low affinity Ca2+ transporter and suggests that Vcx1p may act to attenuate the propagation of Ca2+ signals in this organism.
Subject(s)
Antiporters/physiology , Calcium-Binding Proteins/physiology , Calcium/metabolism , Cation Transport Proteins , Cytosol/metabolism , Ion Exchange , Macrolides , Saccharomyces cerevisiae Proteins , Vacuoles/metabolism , Aequorin/metabolism , Anti-Bacterial Agents/pharmacology , Calcium-Transporting ATPases/physiology , Enzyme Inhibitors/pharmacology , Fungal Proteins/physiology , Mutagenesis , Plasma Membrane Calcium-Transporting ATPases , Saccharomyces cerevisiae , Time FactorsABSTRACT
Clinical, radiological, histological, and anatomical features in 2 patients with necrotizing infundibulo-hypophysitis are reported. The patients presented with a combination of diabetes insipidus and hypopituitarism. Each was found to have a sellar mass lesion with an abnormally thickened enlarged pituitary stalk that intensively enhanced on contrast magnetic resonance imaging. They were suspected to have pituitary tumors with suprasellar extension. However, tissue obtained at transphenoidal surgery revealed necrosis, fibrosis, and chronic inflammation; there was no evidence of infiltrative, infective, or neoplastic disease processes. Postoperatively, they continued to have diabetes insipidus and hypopituitarism despite radiological improvement and steroid therapy. Several clinical and anatomical features distinguish these 2 cases from classical lymphocytic hypophysitis, the most common entity in the differential diagnosis. Specifically, diabetes insipidus has not been observed preoperatively in 30 cases of lymphocytic hypophysitis, but was present in the 2 cases reported. Histological evidence of tissue necrosis present in these 2 cases is not a feature of lymphocytic hypophysitis. Pituitary stalk involvement on magnetic resonance imaging or computed tomographic scan present in these 2 cases is highly unusual in lymphocytic hypophysitis. Finally, 29 of 30 cases of lymphocytic hypophysitis were females, whereas the 2 cases reported are men. On the basis of these disparate findings, we suggest that these 2 cases represent a unique syndrome, which may be recognized clinically and radiologically.
Subject(s)
Arcuate Nucleus of Hypothalamus/pathology , Diabetes Insipidus/complications , Hypopituitarism/complications , Pituitary Diseases/pathology , Adult , Humans , Inflammation , Magnetic Resonance Imaging , Male , Necrosis , Pituitary Diseases/complications , Pituitary Diseases/drug therapy , Pituitary Gland/pathology , Prednisone/therapeutic use , SyndromeABSTRACT
Measurement of the serum thyroglobulin level may be more sensitive than total-body scan using sodium iodide 131 for detecting recurrences from well-differentiated thyroid cancer. We have evaluated the merit of these two methods through a retrospective chart review of patients followed up at the Milton S. Hershey Medical Center, Hershey, Pa. We found that in 17 (45%) of 38 follow-up visits, the presence of interfering antibodies prevented the measurement of serum thyroglobulin levels. Furthermore, such determination was less sensitive than iodine 131 total-body scan in detecting residual thyroid tissue and/or cancer in the neck area. We concluded that iodine 131 total-body scan is the preferable method of follow-up, particularly when the goal of therapy is complete ablation of thyroid tissue.
Subject(s)
Adenocarcinoma/diagnosis , Biomarkers, Tumor/blood , Carcinoma, Papillary/diagnosis , Iodine Radioisotopes , Thyroglobulin/blood , Thyroid Neoplasms/diagnosis , Adenocarcinoma/secondary , Adenocarcinoma/therapy , Adolescent , Adult , Aged , Carcinoma, Papillary/secondary , Carcinoma, Papillary/therapy , Female , Follow-Up Studies , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/diagnosis , Retrospective Studies , Thyroid Neoplasms/therapy , Whole-Body CountingABSTRACT
Thyroid storm is a rare occurrence in the adult population and is even more unusual in children. The current report is of a 3.5-year-old girl who had thyroid storm with unique neurologic manifestations, namely seizure and coma. Acute medical management with propylthiouracil, saturated solution of potassium iodide, hydrocortisone, and propranolol brought about complete resolution of symptoms.
