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Biomedical subjects

R Babayan

Publications and source records attributed to R Babayan.

At least 19 recordsLinked to original sources
PubMed1988

[Technic, limits and complications of breast reconstruction with island flaps of the rectus abdominis muscle].

A definite assessment of mammary repair, using myocutaneous island flaps of the abdominorectal muscle, is likely to underline the unambiguous benefits of the approach. Lasting soft breast consistency, individual adjustability of breast shape, and availability of sufficient tissue quantity are among the major measurable advantages. Caution, however, is necessary for the risk of island flap necrosis in case of excessive ptosis of the breast restored.

Breast↗
PubMed1985

Surgical management of Stage B or C prostatic carcinoma: radical surgery vs radiotherapy.

Radical prostatectomy provides an excellent degree of disease control for the longest period of time in patients with localized prostatic cancer. Although advocates of radiation therapy point to nearly identical survival curves for patients treated with either interstitial or external techniques, an analysis of disease-free survival suggests that radical prostatectomy yields the best long-term "cure." Crude fifteen-year survival rates of 50 per cent may be achieved with radical prostatectomy, compared with 20 per cent to 25 per cent associated with radiation therapy. Additional experience with long-term survival data is necessary before a final conclusion can be drawn from comparison of the two treatment modalities.

Brachytherapy↗
PubMed1984

Radiation damage in rat kidney microvasculature.

Scanning electron microscopy (SEM) combined with a specialized polymer injection casting technique permits the analysis of radiation induced damage in rat kidney glomeruli. A lead shielding device is constructed to enable the irradiation of the living rat left kidney, while the remainder of the animal is shielded from the dose, the right kidney serves as a control. The source of radiation is 137Cs which produces 0.66 MeV gamma-rays to achieve a kidney dose of 100 rad and 5000 rad in these experiments. Radiation damage to kidney glomeruli is assessed at intervals of 0, 1, 3 and 7 days post-irradiation at the two dose levels. It is found that radiation damage to kidney glomeruli is expressed morphologically at 7 days post-irradiation at the 100 rad dose level, while glomerular damage is apparent as early as 3 days post-irradiation at the 5000 rad dose level. Moreover, by 7 days post-irradiation with a 5000 rad dose, the kidney glomerulus thoroughly degenerates to a leaky fused mass of vessels. From a morphological viewpoint, kidney glomeruli are significantly more sensitive to radiation than surrounding vasculature. The methods developed here for assessment of radiation damage are highly repeatable and could serve as a standard technique in radiobiology.

Animals↗
PubMed1983

Maytansine as a cause of acute proliferative disorder of bladder urothelium in the rat.

Male Wistar Lewis rats were injected with maytansine at a total dose of 0.425 to 0.6 mg/kg over a 3-week period. Biopsies taken at 5 weeks showed that 23% of the bladders had hyperplasia or other abnormalities. Of the bladder biopsies done for the first time at 8 weeks, 80% demonstrated papillary hyperplasia. A small number of biopsies at 13 and 19 weeks still showed hyperplasia and minimal inflammatory reaction. These results were seen regardless of prior biopsy, the presence of bladder calculi, and/or the dose level used. It is not clear from the data whether the observed changes are reversible or precarcinogenic. However, these changes closely resembled the histologic features described in the evolution of bladder cancer in rats fed N-C4-(5-nitro-2-furyl)-2-thiazolyl formamide.

Animals↗
PubMed1980

Occupational lead exposure, nephropathy, and renal cancer.

A 48-year-old lead worker was found to have a cystic renal carcinoma during an evaluation of his occupational lead poisoning. Clinical studies showed elevated blood lead levels, impaired urinary concentrating ability, and reduced creatinine clearance. Histologic and electron microscopic studies showed this cystic tumor to be similar to renal carcinomas observed in animals with prolonged lead exposure. Lead content of the tumor was elevated (2.49 micrograms/gm) in comparison with adjacent renal tissue and with normal adult levels. In light of previous animal studies, this case adds increased evidence to the concern over the carcinogenic potential of prolonged lead exposure.

Adenocarcinoma↗
PubMed1979

[Experimental acceleration of fracture repair by biochemical media (author's transl)].

The influence of calcitonine, amino acids, ribonucleid acids, kallikrein, growth hormone, and cyclic adenosine 3'5' monophosphate on fracture repair was tested in rabbits. To obtain an objective measurement of callus stability the bones were bent mechanically. The force applied and the degree of bending were recorded continuously. The slope of the curve was taken as a parameter of callus stability. In the series with calcitonine no influence on fracture healing was found. Injections of ribonucleic acids, amino acids, kallidrein, and growth hormone demonstrated a limited effect on bone repair. Callus formation was stimulated by adenosine 3'5' monophosphate. Optimal results were achieved by a combination of adenosine 3'5' monophosphate, amino acids, ribonucleic acids, and kallikrein.

Amino Acids↗