Myocardial mechanics and energetics in experimental iron-deficiency anemia.

The effect of iron-deficiency anemia on myocardial mechanics and energetics was studied in 10 anesthetized bealge puppies. Nine littermates served as controls. Left ventricular/body weight ratio was increased 14.2% (P less than 0.05) and cardiac index 36.5% (P less than 0.02) in the anemic puppies. Heart rate, mean systolic pressure, myocardial lactate extraction coefficient, and lactic dehydrogenase isozymes were similar in both groups. Contractile state measured in vivo (pressure-velocity curves) and in isolated muscles (isotonic force-velocity curves) was virtually identical in the littermate groups. Despite markedly increased coronary blood flow in the anemia animals, oxygen consumption per unit weight of myocardium was the same in both groups. Contractile element efficiency averaged 18.3% in 10 adult mongrel dogs studied in a similar fashion and was 27.1% and 39.8% in the normal puppies and anemic puppies, respectively. The oxygen cost of internal or force-generating work was similar among the three groups of dogs. It is concluded that the volume load produced by iron-deficiency anemia was associated with a normal contractile state, normal unit myocardial oxygen consumption, no evidence of chronic anaerobiosis, and a high contractile element efficiency, perhaps as a consequence of increased diastolic fiber stretch.     

Incarceration and Sexual Risk: Examining the Relationship Between Men’s Involvement in the Criminal Justice System and Risky Sexual Behavior

In this study, we used data from Add Health Waves II and III to compare men who had been incarcerated to those who had not, and examined whether incarceration was associated with increased numbers of sexual partners and increased odds of concurrent partnerships. We used multivariate regression and propensity-score matching to compare sexual behavior of Wave III male respondents who had been incarcerated with those who had not, and compared sexual behavior at Wave II to identify differences in sexual behavior prior to incarceration. Incarceration was associated with an increased rate of lifetime sexual partnership, but this was attenuated by substance use. Criminal justice involvement was associated with increased odds of having partners who report concurrent partnerships, but no further increase was seen with incarceration. There were no significant sexual behavior differences prior to incarceration. These results suggest that the criminal justice system and substance use may interact to shape sexual behavior.     

Mediastinal lymphadenopathy and pulmonary arterial hypertension in mixed connective tissue disease

A case of mixed connective tissue disease (MCTD) is presented in which mediastinal lymphadenopathy was the most prominent radiological finding detected by plain chest radiographs and computed tomography. Pulmonary arterial hypertension, which is a rare and often fatal complication of MCTD, also developed in this patient.     

Lean body mass and leg power best predict bone mineral density in adolescent girls

PURPOSE: We evaluated anthropometric and performance measures that best predict bone mineral density (BMD) and bone mineral content (BMC) in 54 adolescent girls (14.6 +/- 0.5 yr; 22.7 +/- 14.0 months past menarche). METHODS: Whole body, femoral neck, greater trochanter, lumbar spine (L2-L4), and mid-femoral shaft BMD and BMC, and whole body bone-free lean mass and fat mass were assessed using DXA (Hologic QDR 1000/W). Knee extensor strength and leg power were assessed by isokinetic dynamometry and the Wingate Anaerobic Power Test, respectively. RESULTS: Whole body lean mass was correlated with BMD at all bone sites (r = 0.45-0.77; P < 0.001) and was more highly correlated with bone at all sites than was body weight. Leg power was also associated with BMD at all sites (r = 0.41-0.67; P < 0.001), whereas leg strength correlated significantly with all sites (r = 0.41-0.53; P < 0.001) except the lumbar spine. Stepwise regression analyses revealed that 59% of the variance in whole body BMD was predicted by lean mass alone. No other variables, including fat mass, height, months past menarche, leg power, or leg strength, contributed additionally to the regression model. Similarly, lean mass was the only predictor of lumbar spine and femoral shaft BMD (R2 = 0.25, R2 = 0.37, respectively), while femoral neck and trochanteric BMD were best predicted by leg power (R2 = 0.38, R2 = 0.36, respectively). Similar but stronger models emerged using BMC as the outcome, with lean mass and leg power explaining the most variance in BMC values. CONCLUSION: In this group of adolescent girls, lean body mass and leg power best predicted BMC and BMD of the whole body, lumbar spine, femoral shaft, and hip, which may suggest an important role for muscle mass development during growth to maximize peak bone density.     

Electromyographic evaluation of the midvastus approach

Compared with the standard median parapatellar approach, the muscle-splitting midvastus approach to the knee has led to claims of an easier and earlier recovery after total knee arthroplasty, but some investigators have questioned whether the midvastus approach damages the vastus medialis obliquus. We used electromyographic and nerve conduction studies to evaluate whether we could document any such damage. Twenty patients undergoing bilateral total knee arthroplasty were randomized prospectively for the treatment of 1 knee with each of the 2 approaches. Radiographs, electromyographies, nerve conduction studies, range-of-motion tests, and Knee Society function and pain tests were conducted preoperatively and at 6 weeks postoperatively. If the electromyography or nerve conduction tests were abnormal at 6 weeks, the tests were repeated at 12 weeks. At the final follow-up, these studies showed no evidence of muscle denervation. The midvastus approach appears to be a safe alternative for knee arthrotomy for total knee arthroplasty without concerns for damage to the vastus medialis obliquus.     

Radioimmunotherapy in patients with head and neck squamous cell carcinoma: initial experience

BACKGROUND: Despite improvements in locoregional treatment of stages III/IV squamous cell carcinoma of the head and neck (HNSCC), local and distant failure rates remain high. An effective adjuvant therapy is required for these patients. Among novel approaches is radioimmunotherapy, in which monoclonal antibodies (MAbs) are used for selective delivery of radiation to tumor cells. METHODS: The suitability of 186Re-labeled chimeric MAb U36 (186Re-cMAb U36) for radioimmunotherapy was evaluated in a phase I study, with radiation dose escalating steps of 11, 27, and 41 mCi/m2. Tumor targeting was monitored with a gamma camera, and the maximum tolerated dose was established in 13 patients with recurrent or metastatic disease. RESULTS: Administrations were well tolerated, and excellent targeting of tumor lesions was seen. Myelotoxicity was the only toxicity observed, resulting in dose-limiting toxicity in two patients treated with 41 mCi/m2. The MTD was established at 27 mCi/m2. A marked reduction in tumor size was observed in two patients, another showed stable disease for 6 months. CONCLUSIONS: Radioimmunotherapy with 186Re-cMAb U36 seems to be well tolerated, with bone marrow being the dose-limiting organ. The observation of antitumor effects is encouraging for further development of radioimmunotherapy for HNSCC.     

Postoperative narcotic requirement after microscopic lumbar discectomy is not affected by intraoperative ketorolac or bupivacaine

STUDY DESIGN: Prospective, randomized, double-blind study. OBJECTIVE: To assess the efficacy of ketorolac and bupivacaine in reducing postoperative pain after microsurgical lumbar discectomy. SUMMARY OF BACKGROUND DATA: Microsurgical lumbar discectomy often is performed as an ambulatory procedure. Pain, nausea, and urinary retention may delay discharge. It was hypothesized that intraoperative ketorolac or bupivacaine would reduce postoperative pain as measured by morphine demand. METHODS: After Institutional Review Board (IRB) approval and informed consent, 30 patients undergoing single-level microsurgical lumbar discectomy under general anesthesia randomly received either intravenous ketorolac, intramuscular bupivacaine, or placebo before wound closure. After surgery, all patients received intravenous, MSO4, patient-controlled analgesia. MSO4 demand was compared between groups at 30 minutes and at 1, 4, 8, 16, 20, and 24 hours after surgery by one-way ANOVA. Pre- and postoperative pain was assessed by using a standard scale and was correlated to postoperative MSO4 demand by Pearson correlation. Significance was assumed at P < 0.05. RESULTS: There were no group differences in age, gender, weight, disc level, preoperative pain, or preoperative use of pain medication. Neither ketorolac nor bupivacaine decreased pain or nausea scores, MSO4 demand, or time to void and ambulation. Preoperative pain was significantly correlated to postoperative narcotic demand (r = 0.46, P < 0.01). Preoperative narcotic or NSAID use was not correlated to either preoperative pain scores or postoperative MSO4 requirement. CONCLUSIONS: Neither ketorolac nor bupivacaine decreased the postoperative narcotic requirement in patients undergoing microsurgical lumbar discectomy. Postoperative narcotic requirements are increased in patients who are in severe pain before surgery, regardless of preoperative narcotic use.