Transfer RNA methyltransferase activity in paramecium aurelia

Primary oral tuberculosis: A case series of a rare disease

Tuberculosis (TB) is still one of the most life-threatening infectious diseases, resulting in high mortality in adults and is commonly found in developing countries. Lung is primarily affected while extrapulmonary TB is rarely encountered. Oral lesions, although rare, can be seen in both primary and secondary stages of TB. Primary oral TB may present a diagnostic challenge as its clinical features can be nonspecific that mimics other diseases and is usually misdiagnosed. Thus, it is very important to be aware and be highly suspicious of oral TB especially in endemic area. We share 4 such cases of primary oral TB with uncommon presentations (two on the gingiva, one on the palate and one on the tongue) The diagnosis was made by histopathological examination, polymerase chain reaction analysis and Mantoux test. They were successfully treated with antituberculous treatment. In secondary TB, the oral manifestations may be accompanied by lesions in the lungs, lymph nodes or in any other part of the body and can be detected by a systemic examination.

Isolation and characterization of mRNA from Paramecium aurelia

Total cellular RNA was isolated from the ciliate protozoan Paramecium aurelia by pH 9.5 chloroform/octanol extraction. Passage of this RNA through an oligo(dT)-cellulose column in 0.5 M NaCl resulted in 2--3% binding, indicating the presence of polyadenylic acid sequences. These polyadenylic acid regions were estimated to be 250-500 nucleotides in length, based on their resistance to ribonuclease degradation. The oligo(dT)-cellulose bound RNA sedimented at 14--25 S in sodium dodecyl sulphate/sucrose gradients. The base composition of this RNA is similar to the base composition of the DNA. This RNA was also actively translated into protein by an in vitro protein synthesizing system isolated from wheat germ. Translation was optimal under conditions similar to those used for mammalian mRNA translation. In addition, translation of the P. aurelia oligo(dT)-cellulose bound RNA was inhibited 80% by the analog 7-methylguanosine-5'-phosphate, suggesting the presence of a 5'-capped terminus.