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Biomedical subjects

A M Bagirov

Publications and source records attributed to A M Bagirov.

At least 19 recordsLinked to original sources

New algorithms for multi-class cancer diagnosis using tumor gene expression signatures.

MOTIVATION: The increasing use of DNA microarray-based tumor gene expression profiles for cancer diagnosis requires mathematical methods with high accuracy for solving clustering, feature selection and classification problems of gene expression data. RESULTS: New algorithms are developed for solving clustering, feature selection and classification problems of gene expression data. The clustering algorithm is based on optimization techniques and allows the calculation of clusters step-by-step. This approach allows us to find as many clusters as a data set contains with respect to some tolerance. Feature selection is crucial for a gene expression database. Our feature selection algorithm is based on calculating overlaps of different genes. The database used, contains over 16 000 genes and this number is considerably reduced by feature selection. We propose a classification algorithm where each tissue sample is considered as the center of a cluster which is a ball. The results of numerical experiments confirm that the classification algorithm in combination with the feature selection algorithm perform slightly better than the published results for multi-class classifiers based on support vector machines for this data set. AVAILABILITY: Available on request from the authors.

Algorithms↗

[A physiological method of annuloplasty of the mitral valve].

The work deals with an anatomo-functional substantiation of plastic repair of the mitral valve. Isolated annuloplasty was carried out in 20 patients with mitral incompetence, annuloplasty with aortic prosthetics was conducted in 13 patients. The method allows a prosthesis with a larger diameter to be used in the last named group of patients. A fatal outcome which was not connected with the operative method was encountered in 2 cases. The clinical and hemodynamic effect was good in all patients.

Adolescent↗

[Hemodynamic support of physical loads in patients with ischemic heart disease and a permanent artificial pacemaker].

A study, using noninvasive monitoring during bicycle ergometry, was carried out to assess hemodynamic support of physical stress in coronary patients with implanted pacemaker (IPM). Heart contractility of IPM-carrying coronary patients was reduced, with capacity for compensation diminished even at rest, while exercise contributed to further deterioration of those. Adequate hemodynamic support of stress was only observed in patients belonging to the second functional class.

Adult↗

[Vascular complications of kidney transplantation].

584 kidney transplantations (208 from cadaveric donors, 376 from living relative donors) were performed in Medical Faculties of the Istambul University in 1986-1997. Thrombosis of the renal artery was observed in 2 patients (0.35%). One of them had diffused arterial atherosclerosis 4 months after the kidney transplantation. In spite of two successful thrombectomies, the patient died 3 months after the last surgical procedure from cerebral thrombosis. The other patient underwent nephrectomy. Hypertension was observed in 63 patients. In 5 of them about 50% stenosis of the anastomotic area was detected by doppler duplex scan and selective angiogram. Transluminal angioplasty was performed in one patient, open surgical correction in one case. Renal vein thrombosis took place in 1 (0.2%) patient. In 2 cases (0.35%) 5 and 12 years after the transplantation aortic aneurysmal dissection was observed.

Adult↗