Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Q: Abstract: Recurrent pulmonary embolism from the lower extremities or pelvis, despite anticoagulation, often requires interruption of the inferior vena cava (IVC). We report two patients in whom interruption of the IVC failed to ameliorate symptoms. Both patients demonstrated a previously unrecognized duplication of the IVC. We stress the importance of excluding abdominal venous anomalies prior to interrupting the IVC using surgical or percutaneous methods.

A: Duplication of the inferior vena cava in thromboembolic disease.
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Q: Abstract: Forty male and 40 female rats were randomly assigned to 1 of 4 experimental groups. Half of the animals of each gender were exercised by jumping (weighted by a vest with up to 70% body weight) to a height of 16 cm 20 times X d-1 (30 s between jumps) 5 d X wk-1 for 8 wk. Half of the exercised animals and half of the sedentary animals were injected with the anabolic steroid durabolin (0.2 mg in 0.1 ml sesame seed oil) 6 d X wk-1 for the last 3 wk of the 8-wk exercise program. The other animals were injected with 0.1 ml of sesame seed oil (as a placebo) on the same schedule. At the end of the 8-wk program, blood was drawn from the right atria of the anesthetized animals. Plasmas were analyzed for total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) concentrations. Low density lipoprotein cholesterol (LDL-C) concentration was estimated as the difference between these two parameters (TC - HDL-C). A three-factor analysis of variance (2 X 2 X 2) demonstrated that there was a significant (P less than 0.05) gender effect (males greater than females), but no steroid or exercise main effects for TC. There were significant (P less than 0.05) steroid and exercise main effects for both HDL-C and estimated LDL-C, as well as a significant gender main effect for estimated LDL-C (but not HDL-C).(ABSTRACT TRUNCATED AT 250 WORDS)

A: Effects of exercise and anabolic steroids on total and lipoprotein cholesterol concentrations in male and female rats.
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Q: Abstract: The purpose of this study was to evaluate the effect of long-term anemia and subsequent retransfusion of erythrocytes on various circulatory parameters. Anemia was induced in nine healthy male subjects by repeated venesections. The stored blood was retransfused after 9 wk (range 8-11 wk). Exercise tests were performed before venesection in the control state (C), in the anemic state (A), and 48 h after retransfusion (R). Hemoglobin concentration levels were 146 +/- 10 g/l in C, 110 +/- 7 g/l in A, and 145 +/- 9 g/l in R. Maximal O2 uptake was 4.55 +/- 0.6, 3.74 +/- 0.7, and 4.45 +/- 0.6 l/min in C, A, and R, respectively. A decrease in heart rate of 7 beats/min (P less than 0.01) and in cardiac output of 2 l/min (P less than 0.05) at maximal exercise occurred in the anemic state compared with control values. These decreases were not reversed but, rather, were further accentuated after retransfusion. The adaptive response to submaximal exercise (cycling at 150-175 W) in anemia was mediated to the amount of 50% by an increase in cardiac output (mainly an increase in heart rate) and 50% was due to increased O2 extraction in the peripheral tissue. In conclusion, long-term anemia was found to decrease the heart rate and cardiac output at maximal exercise. Furthermore the close correlation between hemoglobin concentration and maximal O2 uptake in humans is confirmed.

A:
Effect of long-term anemia and retransfusion on central circulation during exercise.
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