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Biomedical subjects

N Natarajan

Publications and source records attributed to N Natarajan.

71 records · Page 4Linked to original sources
PubMed1982

Treatment and follow-up study of squamous cell carcinoma in situ of the cervix uteri.

The survey of approved cancer programs done by the Commission on Cancer of the American College of Surgeons observed a total of 9,468 patients with a diagnosis of in situ squamous cell carcinoma of the cervix uteri. Sixty-four per cent of these patients had been observed for at least nine years. The most commonly used definitive treatment was hysterectomy. Recurrences were observed after hysterectomy, conization and radiation therapy. There were significantly more recurrences in the group treated by conization compared with those treated by hysterectomy. The highest rate of second cancer primary to the vagina, vulva, uterus or ovaries was among patients who received no treatment. The cancer specific, ten year survival rate for those with no treatment was 96.6 per cent, and for those treated by conization or by hysterectomy, the rates were 99.3 and 99.8 per cent, respectively.

Adult↗
PubMed1981

Premature ventricular complexes in the absence of identifiable heart disease.

To define the prevalence, frequency and characteristics of premature ventricular complexes (PVCs) in adults free of recognizable heart disease, we performed 24-hour ambulatory electrocardiography on 101 subjects (51 men and 50 women, mean age 48.8 years) in whom physical examination, chest x-ray, ECG, echocardiogram, maximal exercise stress test, right- and left-heart catheterization and coronary arteriography were normal. Thirty-nine subjects had at least 1 PVC/24 hours, but only four had more than 100 PVCs/24 hours and fewer than five had more than five PVCs in any given hour. The probability of having at least 1 PVC/24 hours increased with age (chi square = 11.789, p = 0.019). The number of PVCs/24 hours was also positively associated with age (4 = 0.33, p = 0.001). These was no consistent relationship between the presence or number of PVCs/24 hours and sex, blood pressure, weight, height, body mass index, serum potassium or calcium, cholesterol and triglyceride, hemoglobin, the ingestion of coffee, tea or alcohol, and cigarette smoking. Four subjects had multiform PVCs, two of whom had early PVCs.

Adolescent↗
PubMed1981

Trends in the United States for the management of adenocarcinoma of the rectum.

Data from surveys conducted by the Commission on Cancer of the American College of Surgeons were examined to identify recent trends in the treatment of carcinoma of the rectum. Between 1973 and 1978, the stage of disease at diagnosis for the total series changed little, but significant upgrading in the stage of disease at diagnosis for the black patients was observed. There was increasing use of a multimodality approach to treatment combining operation with radiotherapy. The use of chemotherapy alone or in combination with other therapies, while never widely used, declined during the interval observed. Significant changes occurred in the type of operations performed for carcinoma in the upper two-thirds of the rectum. During this interval, abdominoperineal resection was increasingly being displaced by low anterior resection. The trend toward multimodality treatment and the use of effective sphincter preserving procedures represent significant changes noted in this survey in the therapy of carcinoma of the rectum.

Adenocarcinoma↗
PubMed1979

The pathophysiology and diverse etiology of septal perforator compression.

Compression of the septal perforator branches of the left anterior descending artery (systolic obliteration and diastolic reopacification during arteriography) has been proposed as a marker of idiopathic hypertrophic subaortic stenosis (IHSS). Among 568 unselected coronary arteriograms this angiographic finding was pronounced in 11 of 17 patients with IHSS; in 12 of 44 with aortic stenosis (AS); in five of 46 patients with severe (95%) proximal stenosis of the left anterior descending coronary artery; in three of 18 with myocardial bridge; in three of 12 with hypertrophic cardiomyopathy; in one of 62 with normal right and left heart catheterization; and in none of the 369 patients with other cardiac diseases. Mild septal perforator compression (SPC) was observed in six other patients with IHSS, one patient with hypertrophic cardiomyopathy, 19 patients with AS, eight patients with severe stenosis of the LAD and one patient with myocardial bridge. SPC was more pronounced in patients with high systolic pressure gradients (Spearmann Rank r = 0.64, p = 0.003 and Pearson r = 0.31, p = 0.159 for IHSS; Spearmann Rank r = 0.47, p = 0.001; Pearson r = 0.51, p = 0.001 for AS) and increased septal thickness (Spearmann Rank r = 0.45, p = 0.05, Pearson r = 0.61, p = 0.011 for IHSS; Spearmann r = 0.44, p = 0.013, Pearson r = 0.42, p = 0.018 for AS). SPC is not specific for IHSS. It may result from a decrease of the intraluminal pressure in the septal perforators resulting from obstruction at the left ventricular, aortic valvular or coronary arterial level and from increased septal thickness which may lead to higher extraluminal pressure.

Aortic Valve Stenosis↗
PubMed1977

Genetic damage from diagnostic radiation.

Using the data from the Tri-State Leukemia Survey and a mathematical model, the hypothesis that low levels of diagnostic radiation produce severe genetic damage that is expressed in the child of the exposed person as leukemia and other diseases is tested. It is estimated that for about 1% of the exposed persons who are affected by radiation, there is a 50-fold increase in the risk of leukemia and a five-fold increase in certain other diseases.

Adolescent↗
PubMed1977

Multiple fistulas between the coronary arteries and the left ventricle.

The authors report a case of fistulas connecting the anterior descending, circumflex, and dominant right coronary arteries with the left ventricle. Although fistulous connections between a coronary artery and a cardiac chamber have been described before, this is only the third known case in which all of the coronary arteries communicated with the left ventricle.

Coronary Vessels↗
PubMedDate not supplied

Cumulative genetic damage in children exposed to preconception and intrauterine radiation.

Using a mathematical model and newly developed computer software, the data from the Tri-State Leukemia Survey involving different combinations of radiation exposures to the father and mother prior to conception and to the mother during pregnancy were analyzed. The hypothesis that radiation exposure produces genetic damage which may be expressed in the child both as indicator disease and as leukemia was tested. The genetic damage was estimated in terms of the proportion affected by a given exposure. The relative risk of leukemia and certain other indicator diseases among those "affected" could then be estimated. The results were obtained by direct minimization of the total chi-square. The results show that there are at least two distinguishable risk groups, one group with lower (one or two exposures), and the other group with higher (two or three) radiation exposures. The estimates for the proportion affected are 0.13 and .04 for the lower and higher exposure groups, respectively. The relative risks of leukemia and indicator diseases are 25.0 and 5.0, respectively. The 95% confidence intervals for the proportion affected in the lower and higher exposure categories are (.0075, .02) and (.028, .055), respectively, and for the relative risk of leukemia are (16.0, 35.0). These results have confirmed and extended the findings of our preliminary report published in the Journal of the American Medical Association in May 1977.

Adolescent↗
PubMedDate not supplied

Pretreatment transurethral resection of prostate cancer and disease-free survival.

Data from the American College of Surgeons' national survey on prostate cancer were analyzed to determine whether recurrence-free survival differs between those patients diagnosed by transurethral resection of the prostate (TURP) and those diagnosed by needle biopsy. Only patients who received radiation therapy as treatment were included in this analysis. There were 461 patients diagnosed by TURP and 541 patients by needle biopsy. Disease free survival was calculated according to the state and tumor differentiation. Except in stage B1, none of the groups showed a statistically significant difference in recurrence-free survival between the two diagnostic procedures. The results of this analysis suggest that the disease-free survival of patients with radiation-treated prostate cancer diagnosed by TURP and needle biopsy are similar.

Aged↗