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M Schwartz

Publications and source records attributed to M Schwartz.

967 records · Page 54Linked to original sources
PubMedDate not supplied

[Preservation of rat liver using prolonged perfusion with a complex solution lacking hemoglobin].

The author's aim was to investigate conservation of rat liver by continuous perfusion of the isolated organ in conditions of normal temperature, as well as in hypothermia. A complex solution was used, lacking hemoglobin. Over a period of 5 hours of conservation the authors evaluated the perfusion rate, the concentration of lactate and pyruvate in the conservation medium, while on histological preparations was investigated the formation of fibrin deposits in the intra-hepatic vessels. The results confirmed the positive effects of hypothermia, that is not due exclusively to a limiting of the metabolic necessities of the organ but also to a reduction of the fibrinogenesis and a slowing down of the formation of intra-hepatic microaggregates.

Animals↗
PubMedDate not supplied

Hormone receptors and disease-free survival in breast cancer: impact of increasing threshold levels.

Laboratory data from Milan and Houston were evaluated to determine the extent to which the distribution of estrogen receptor (ER) and progesterone receptor (PgR) has changed with time. Results from over 11,500 ER and over 8,200 PgR determinations (6,194 ER and 3,127 PgR from Milan) were analyzed. All assays in Milan were performed by a dextran-coated charcoal method and in Houston by a sucrose density-gradient method. The data demonstrate a time-dependent, upward drift in the amount of ER and PgR detected, with the effect most pronounced at the lower end of the distribution curves. We attribute this change to optimization of all facets of the receptor assay procedures (tissue harvesting and storage) as well as to a change in breast cancer biology. These results suggest that studies correlating certain biological parameters with receptor status (whether using qualitative or quantitative scales) need to be re-examined. For example, a population of 349 node-negative patients who did not receive any adjuvant treatment was studied in Milan to determine any association between disease-free survival (DFS) and receptor status. If the "historical" threshold values (10 fmol/mg protein) were used to determine receptor status, no significant difference in DFS at 5 years was detected. Even the combination of ER and PgR did not improve the predictive power of receptor status. In the premenopausal subgroup, ER status did predict the 5-year DFS. However, if the threshold value for PgR was adjusted to 25 fmol/mg protein, patients with ER-positive, PgR-positive tumors had significantly better 5-year DFS than patients with ER-negative, PgR-negative tumors. In addition, PgR status alone was associated with significantly improved 3-year DFS if the subgroups of PgR less than 5 fmol/mg protein and PgR greater than 100 fmol/mg protein were compared. We conclude from these data that: 1) historical threshold values for receptor positivity should be re-examined in all laboratories; 2) studies involving receptor results determined over an extended period of time should attempt to "normalize" these results; and 3) the quantitative assessment of receptor status should be used whenever possible.

Biomarkers, Tumor↗
PubMedDate not supplied

Aorto-caval fistula: a clinical spectrum.

Ten cases of aortocaval fistula (ACF) associated with abdominal aortic aneurysm (AAA) were reviewed. In 5 cases the ACF became apparent after evacuation of the thrombus; only 5 patients presented with features of patent ACF. Four patients in addition presented with extra-caval rupture of the aneurysm. Based on these variables, a classification relating ACF and AAA was developed. In this series all patients were male with a mean aneurysm size of 8.5 cm. All patients required bifurcation grafts for reconstruction. A multifactorial etiology related to enlargement and rupture of all aneurysms seems to apply to ACF. Eight of 10 patients survived. Awareness of this entity and proper preparation allow for successful outcome in the treatment of this condition.

Aged↗
PubMedDate not supplied

Variations in treatment of postmenopausal osteoporosis.

The purpose of this study was to determine trends and differences between various medical specialties with regard to the treatment of postmenopausal osteoporosis. The method used was a cross-sectional survey, and the authors' sample was composed of 116 physicians. There was an overall lack of consensus on choice of treatment for postmenopausal osteoporosis. Treatment varies with the individual physician without any strict adherence to a formal therapeutic protocol. Calcium was the treatment modality most widely used by all the specialties. Gynecologists and endocrinologists show the greatest usage of estrogens, while orthopedic surgeons show the least. Fluoride was used significantly less than calcium, vitamin D, estrogen, diet, and exercise by all the specialties surveyed. One in three postmenopausal women in the United States has osteoporosis, and one in five will sustain a hip or vertebral fracture. Twelve to twenty percent of elderly patients die within six months of sustaining a hip fracture. There is an obvious need for carefully constructed clinical programs evaluating multiple agents and diagnostic techniques.

Attitude of Health Personnel↗
PubMedDate not supplied

Viscoelastic measurement of clot formation: a new test of platelet function.

Assessment of platelet function presents a challenge to the investigators in the clinical field. An instrument, Sonoclot, is described which measures changes in the viscoelastic properties (clot impedance on a vibrating probe) of plasma as it is recalcified. Platelet poor plasma (PPP) and platelet rich plasma (PRP) show distinct and characteristic Sonoclot tracings. Tracings of PPP show a lag period and a primary wave. These parameters correspond to recalcification time and fibrin polymerization. Tracings of PRP show, in addition, a secondary wave and a downward wave. These parameters correspond to the incorporation of platelets in the clot and retraction of the clot. The PRP parameters are influenced by the number and quality of the platelets. This instrument was utilized to assess the platelet function in patients after coronary artery bypass surgery (CAB). In 69 patients studied, 20 patients did not have excessive bleeding. The clot impedance tracings in this group were normal. Twenty-four patients had excessive bleeding, normal clot impedance, and coagulation tests indicating the possibility of surgical bleeding. This was confirmed in 22 (92 percent) patients upon exploration to control bleeding. Twenty-five patients had excessive bleeding, normal coagulation tests and abnormal clot impedance suggesting platelet dysfunction. In twenty-one (84 percent) of the patients, transfusion of platelet concentrate controlled the bleeding with corresponding correction of clot impedance. Sonoclot studies are quick and easy to perform, and appear to be a valuable and reliable adjunct in the diagnosis of hemostatic problems after CAB surgery.

Bleeding Time↗
PubMedDate not supplied

Utilization of ovarian cancer screening by women at increased risk.

Our objective was to identify demographic, medical, and psychological correlates of ovarian cancer screening utilization in a sample of women at increased risk. We designed a cross-sectional study that evaluated demographic factors, risk factors, psychological factors, and utilization of ovarian cancer screening in first-degree relatives of ovarian cancer patients. In multivariable analysis, use of CA-125 was associated with number of affected relatives [odds ratio (OR), 2.9; 95% confidence interval (95% CI), 1.3-6.5] and ovarian cancer worries (OR, 2.9; 95% CI, 1.1-8.1). For ultrasound (transvaginal or abdominal), the model included employment status (OR, 2.7; 95% CI, 1.1-6.8) and ovarian cancer worries (OR, 3.3; 95% CI, 1.2-9.1). Significant interaction terms in the ultrasound models indicated that employment was a significant predictor of ultrasound utilization in women with 2 or more affected relatives. Among women with only one affected relative, ultrasound use was strongly associated with the presence of ovarian cancer worries. Utilization of ovarian cancer screening among women at increased risk is influenced by psychological and sociodemographic factors, in addition to level of risk.

Adolescent↗