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Biomedical subjects

K Raghu

Publications and source records attributed to K Raghu.

32 records · Page 2Linked to original sources
PubMed1976

Methylation and aging in Rhizoctonia solani.

Our earlier studies had shown that as fungi age, many of their vital functions decrease; in Rhizoctonia solani, protein synthesis is one of the functions so affected. We now find that the ability to methylate tRNA, a vital component of the protein synthesizing system, also decreases with age. This methylation of Escherichia coli tRNA by R. solani methylase preparations increased with the concentration of enzyme and with time of incubation; in both cases the rate of increase was considerably higher for preparations from young cells than for those from old cells. The methylation reaction also increased with the concentration of substrate tRNA, with temperature, at least to 45 degrees C, and with pH to 9.0. Methylase preparations from R. solani methylated both exogenous E. coli tRNA and yeast tRNA, but were only weakly active on isolated R. solani tRNA. However, acid-precipitated methylases from R. solani were very effective in methylating the homologous exogenous tRNA. Regardless of the source of the tRNA used as substrate, the methylases from older cells were always less active than those from young cells from the same mycelium. No methylase inhibitor was detected in the fungus.

Escherichia coli↗
PubMed1966

Biodegradation of the gamma isomer of benzene hexachloride in submerged soils.

Determination of the residual gamma isomer of benzene hexachloride (gamma-BHC) by gas chromatography showed that the insecticide persisted longer in sterilized flooded soils than in nonsterilized flooded soils. A second addition of gamma-BHC to one of the nonsterilized soils. (55 days after the first application) disappepsilonared more rapidly than the first addition. These results strongly indicate biodegradation of gamma-BHC in flooded soils.

Chromatography, Gas↗
PubMedDate not supplied

Absent coronary venous sinus: a rare anomaly.

A 42-year-old man, presenting with dyspnea on exertion and ST segment depression on treadmill test, was found to have absent coronary venous sinus on coronary angiography. We report this case of isolated congenital absence of coronary venous sinus because of its rarity.

Adult↗
PubMedDate not supplied

Transesophageal echocardiography for the detection of left atrial thrombus.

We performed transesophageal two-dimensional echocardiography (TEE) and compared its results with those of transthoracic echocardiography (TTE) in a series of 120 patients with rheumatic mitral stenosis (MS). The patients were selected from a pool of 2000 patients of rheumatic heart disease assessed earlier by clinical examination and TTE. The selection criteria for TEE included one or more of the following: 1. Atrial fibrillation, 2. Embolic episode, 3. Before closed mitral valvotomy or balloon mitral valvuloplasty, 4. Large left atrium (LA) and 5. Evidence of clot or spontaneous echo-contrast in LA. The aim was to study the usefulness of TEE as compared to TTE in the detection of thrombus in LA. LA thrombus was imaged in 34/120 TEE studies as compared to 21/120 TTE studies. In 12/13 patients in whom TTE failed, the clot was present in the left atrial appendage (LAA). In the remaining one patient, poor echo window for TTE was responsible. In 2/6 patients with embolic episode, neither TTE nor TEE could document the presence of clot in LA. The procedure of TEE was well tolerated and there were no complications. We conclude that TEE is a safe and valuable adjunct to TTE with better diagnostic ability for the detection of LA thrombus and should be performed in all patients with MS in whom a clot in LA is suspected or needs to be excluded.

Adolescent↗
PubMedDate not supplied

Distribution of cholesterol in HDL and its subfractions in patients with coronary atherosclerotic heart disease.

The distribution of HDL-C and its subclasses HDL3-C and HDL2-C and other serum lipids was studied in patients with coronary atherosclerotic heart disease grouped as young males (group 1) and older males (group 2) along with age matched controls. All the patients had significantly higher levels of serum cholesterol, triglycerides, LDL-C and VLDL-C and lower levels of HDL-C. The analysis of HDL - subclasses clearly demonstrated that the low levels of HDL-C was due to the significant decrease of cholesterol in both HDL3 (group 1: 32%; group 2: 30%) and HDL2 subclasses (group 1: 55%; group 2: 48%) compared to the respective control values. Further it has also been observed that this low level of HDL-C is a characteristic feature of patients irrespective of whether the levels of serum cholesterol and triglycerides are high or normal. Although both the HDL subclasses were decreased, the percentage of reduction of cholesterol was greater in the HDL2 than in HDL3 subclass. In addition, the levels of cholesterol either in HDL or any of its subclasses, HDL3 and HDL2 did not show any change in relation to the extent of coronary disease which was assessed by coronary angiography. This study confirms the inverse relation of HDL-C with coronary atherosclerosis and also indicates that, of all the lipid parameters examined, only HDL-C, particularly its subclass HDL2-C, shows independent inverse relation to the incidence of coronary atherosclerotic artery disease in men.

Adult↗