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Biomedical subjects

A Medina

Publications and source records attributed to A Medina.

At least 163 records · Page 9Linked to original sources
PubMed1984

Discriminant value of clinical and exercise variables in detecting significant coronary artery disease in asymptomatic men.

To determine whether clinical or exercise test variables could reliably detect coronary disease in asymptomatic men, several variables were compared with angiographic findings in 225 asymptomatic men. None of the individual clinical or rest electrocardiographic variables were able to detect coronary artery disease. The three individual exercise variables with a high likelihood ratio were: 1) at least 0.3 mV ST depression, 2) persistence of ST depression 6 minutes after exercise, and 3) total duration of exercise of less than 10 minutes. However, because of low sensitivity and predictive value, these single variables were not helpful in identifying individual patients with coronary disease. The combination of any single clinical risk factor and any two of these exercise risk predictors was highly predictive (89%) but relatively insensitive (37%) for detecting any coronary disease. These criteria have a sensitivity of 55% and a predictive value of 84% for the detection of two and three vessel coronary disease. The effectiveness of exercise testing for detecting asymptomatic coronary disease is improved when the group is first screened for the presence of risk factors and additional exercise variables other than ST segment criteria are evaluated.

Adult↗
PubMed1983

[Bouveret syndrome].

Bouveret syndrome, a rare form of gallstone ileus predominantly encountered in elderly female patients, is clinically characterized by the sequelae of duodenal obstruction. Two patients observed within one year are presented and the clinical, diagnostic and therapeutic aspects of the disease are discussed. The surgical treatment of choice is one-stage removal of stone, closure of fistula and cholecystectomy completed by a careful search for residual stones in the small and large intestine.

Aged↗
PubMed1982

Services for pregnant teenagers in the large cities of the United States, 1970-1980.

This article reports the findings of the third national survey of services for and needs of pregnant teenagers and their infants in the large cities of the United States, done in 1979-1980. Only five cities have developed a new program since 1976, and major unmet needs continue to exist. The survey also provides baseline data on the status of health, social, and educational care for this target population. With the substantial decrease in the various sources of federal funds due to current budgetary reduction, continued monitoring is required to determine the effects on services for pregnant teenagers and their infants, as well as on the incidence of teenage pregnancy.

Abortion, Legal↗
PubMed1982

Synthesis and assembly of hepatitis B virus surface antigen particles in yeast.

The surface antigens of hepatitis B virus (HBsAg) has been synthesized in the yeast Saccharomyces cerevisiae by using an expression vector that employs the 5'-flanking region of yeast alcohol dehydrogenase I as a promotor to transcribe surface antigen coding sequences. The protein synthesized in yeast is assembled into particles having properties similar to the 22-nm particles secreted by human cells.

Alcohol Dehydrogenase↗
PubMed1982

Pregnancy outcomes of Indochinese refugees, Santa Clara County, California.

Birth certificates and a sample of hospital obstetric records for Indochinese refugees in Santa Clara County, CA, 1979-1980, were reviewed. Among 542 live births, the overall median birthweight of 3175 gm and 5.7 per cent rate of low birthweight were favorable; it is our impression that the more recent arrivals, especially Cambodians and Laotians, present at greater risk, lacking prenatal care, and have more infants of low birth rate and more pregnancy complications.

Adolescent↗
PubMed1980

Deoxyribonucleic acid polymerase from the marine Pseudomonas sp. BAL-31.

A deoxyribonucleic acid (DNA)-dependent DNA polymerase (DNA nucleotidyltransferase) was purified 3,000-fold from the marine Pseuodomonas sp. BAL-31. The molecular weight of the native enzyme was estimated by glycerol gradient sedimentation to be 110,000. The enzyme migrated in sodium dodecyl sulfate-acrylamide gels as a single polypeptide with a molecular weight of 105,000. An absolute requirement for divalent cation was satisfied by Mg2+ or Mn2+ at concentrations of 1 mM. Monovalent cations at concentrations higher than 50 mM showed an inhibitory effect. The polymerase activity was resistant to N-ethylmaleimide and showed a wide pH optimum.

DNA-Directed DNA Polymerase↗
PubMed1980

[Pleomorphic adenoma of the breast].

The pleomorphic adenoma (mixed tumor) of the mammary gland is a rare benign tumor. Clinically, mammographically and histologically it can, on the basis of a quick-biopsy examination, be confounded with a carcinoma. We relate on a case of our own where the diagnostic difficulties conducted to an inadequate amputation of the mammary gland.

Adult↗
PubMed1979

[Breast cancer in men].

Carcinoma of the breast is relatively uncommon in men. Represents somewhere between 0.9 to 1.5 of all tumors of the breast. Most patients are within the 7th to 8th decade of life. The most common symptoms at the time of presentation are a tumor mass in either breast, ulceration of the nipple or nipple retraction or fixation of the skin. Extension to the axiliar nodes takes place early in the course of the disease. The presence of nipple discharge should be considered expression of carcinoma of the breast unless otherwise proven. The final diagnosis is established by biopsy. The most common form of carcinoma of the breast is the ductal carcinoma. The surgical management takes basically that followed in carcinoma of the breast in the female patient. Also orquiectomy has been used which is equivalent to ovariectomy in woman. In the presence of metastasis both estrogens and androgens have been used. Hypophysectomy and post-op radiation therapy has been used. Most recently chemotherapy has been widely used in those cases with widespread metastasis. However, in spite of all these efforts carcinoma of the breast in the male still carries a very serious prognosis. We present our experience in 16 cases.

Aged↗