Temporary leukocyte depletion reduces ventricular dysfunction during prolonged postischemic reperfusion

Leukocyte depletion improves early postischemic ventricular performance in neonatal models of global myocardial ischemia. However, the rate of leukocyte reaccumulation after cardiopulmonary bypass and its subsequent impact on myocardial function is not known. This laboratory study examined the effect of leukocyte depletion on myocardial performance during the initial 6-hour period after bypass in an in situ, in vivo porcine model of neonatal cardiac surgery. Fifteen 3- to 5-day-old piglets (eight control and seven leukocyte depleted animals) were instrumented by placement of left ventricular short-axis sonomicrometry crystals and an intraventricular micromanometer catheter. Mechanical leukocyte depletion was achieved with Pall RC100 filters (Pall Biomedical, Inc., Fajardo, Puerto Rico) in the cardiopulmonary bypass circuit. Neonatal hearts were subjected to 90 minutes of hypothermic ischemia after a single dose of cold crystalloid cardioplegia. Two control animals died after the operation and were excluded from data analysis. Leukocyte filtration reduced the granulocyte count during initial myocardial reperfusion to 0.8% of control values. However, circulating granulocyte counts increased in leukocyte depleted animals throughout the postoperative period, reaching 68% of control values by 6 hours. Despite this rapid return of circulating granulocytes, animals subjected to leukocyte depletion had significantly better preservation of left ventricular performance (measured by preload recruitable stroke work, p < or = 0.02), left ventricular systolic function (measured by end-systolic pressure-volume relationship, p < or = 0.05), and ventricular compliance (p < or = 0.04) during the experiment. These changes in ventricular function were associated with a significant increase in left ventricular water content (p < or = 0.02) and tissue myeloperoxidase activity (p < or = 0.005) in control animals compared with leukocyte depleted animals. This study demonstrates that leukocyte depletion during initial reperfusion results in sustained improvement in postischemic left ventricular function despite the rapid return of granulocytes to the circulation.     

Dopamine and the regulation of cell proliferation in gerbil (Meriones unguiculatus) pyloric mucosa

The epithelium of the digestive system mucosa consists of a highly dynamic cell population. The conditions under which mitotic activity in the gastrointestinal epithelium is regulated is as yet poorly understood. Nevertheless, it is assumed that some biogenic amines might be involved. Having demonstrated that dopaminergic cells occur in the stomach of gerbils (Meriones unguiculatus), in the present study we examined the influence of dopamine antagonist haloperidol on the proliferation of epithelial cells in the mucosa of the stomach. Proliferating cells were detected immunocytochemically and quantified after in-vivo labeling with 5-bromo-2'-desoxyuridine in both haloperidol- and saline-treated animals. The results show that acute doses of haloperidol significantly increases the proliferation rate in the pyloric mucosa, suggesting that dopamine plays a probable modulatory role in the regulation of mitotic activity. These findings are discussed with regard to the role of paraneurons in regulating epithelial mitosis.     

Risedronate

Risedronate is a pyridinyl bisphosphonate that can be administered orally in lower dosages than other antiresorptive bisphosphonates. Like others of its class risedronate inhibits osteoclast-mediated bone resorption. In experimental models of osteoporosis, risedronate inhibited bone loss and improved trabecular architecture. In patients with Paget's disease, pain diminished or disappeared and serum alkaline phosphatase levels decreased after treatment with oral risedronate 30 mg/day for < or = 3 months. Risedronate 30 mg/day orally for 2 months significantly reduced pain, whereas etidronate 400 mg/day orally for 6 months tended to reduce pain, in a randomised double-blind trial of patients with Paget's disease. Oral risedronate 5 mg/day for < or = 2 years increased bone mass in postmenopausal women with low or normal bone mass. Risedronate 2.5 mg/day prevented bone loss in postmenopausal women treated with glucocorticoids for rheumatoid arthritis. The incidence of gastrointestinal or other adverse events was similar in patients treated with risedronate or placebo in clinical trials.     

Pharmacokinetics of hyperimmune anti-human immunodeficiency virus immunoglobulin in persons with AIDS

Hyperimmune anti-human immunodeficiency virus immunoglobulin (HIVIG) is an intravenous immunoglobulin prepared from HIV-infected asymptomatic donors with a CD4 cell count greater than 400 cells/microl and a high titer of antibody to HIV-1 p24 protein. Twelve persons with AIDS received four doses of HMG (two at 50 mg/kg of body weight and then two at 200 mg/kg) every 28 days. Pharmacokinetics were evaluated by measurement of anti-p24 antibody. HIVIG was well tolerated, and all participants completed the study. Three subjects who were not receiving Pneumocystis carinii pneumonia (PCP) prophylaxis developed PCP. The mean value for HIVIG clearance was 3.02 ml/kg/day at 50 mg/kg and 3.65 ml/kg/day at 200 mg/kg (P = 0.027); the mean trough antibody titers (reciprocal units) were 1,442 and 4,428, respectively. This study indicates that high titers of anti-p24 antibody can be maintained with a monthly administration schedule of HIVIG and that short-term safety is acceptable. Comparisons to evaluate the therapeutic potential of HIVIG are justified.     

Chances of cure are not compromised with sphincter-saving procedures for cancer of the lower third of the rectum

BACKGROUND: The goal of this study was to compare patterns of recurrence and long-term outcome after sphincter-saving procedures (SSPs) and abdominoperineal resection (APR) in patients with tumors located in the lower third of the rectum. METHODS: We reviewed the charts of 1001 patients operated on for primary rectal adenocarcinoma between 1980 and 1991. All patients with tumors located between 5 and 7 cm from the anal verge and treated with curative intent were included. RESULTS: Of the 261 patients who met our criteria, 162 had undergone SSP and 99 had undergone APR. The local recurrence rates for SSP and APR were 8% and 11%, respectively (p = 0.41), and the distant metastases rates were 23% and 28%, respectively (p = 0.35). Recurrence and distant metastases rates for SSP and APR, respectively, did not differ by TNM classification: state I, 10% versus 9% (p = 0.9); stage II, 25% versus 43% (p = 0.13); and stage III, 56% versus 57% (p = 0.92). Five-year disease-free survival rates for SSP and APR patients were 70.5% and 62.3%, respectively (p = 0.2). CONCLUSIONS: Tumors in the lower third of the rectum can be treated with sphincter-saving procedures without compromising the chance of cure.     

A comparative cerebral blood flow study in a baboon model with acetazolamide provocation: 99mTc-HMPAO vs 123I(IMP)

Pharmacological interactions are important when nuclear medical procedures are applied to patients under drug therapy, or drug provocation. This study compares in baboon models (regional) cerebral blood flow [(r)CBF] results from 99mTc-HMPAO and 123I-iodoamphetamine [123I(IMP)] each with and without acetazolamide, the latter a suggested drug for testing cerebrovascular reserve. Expected differences in cerebral uptake were observed between the two radio-tracers without acetazolamide. The increase in tracer uptake resulting from acetazolamide is significantly enhanced for 123I(IMP), which could have diagnostic implications.     

Palatability of prerigor cooked boar meat

Cooking reduces odor intensity in boar meat but also may induce lipid oxidation unless the meat pH is above approximately 6.0. This research was designed to determine the feasibility of cooking boar meat in the prerigor state to overcome boar odor and lipid oxidation problems. Prerigor and postrigor triceps brachii muscle samples from 40 boars (20 Duroc and 20 Yorkshire) were cooked to 60 degrees C, frozen and stored at -20 degrees C, reheated in a 60 degrees C water bath for 1 h, and then subjected to pH, thiobarbituric acid (TBA), and sensory analyses. Boar odor intensity and skatole concentration in backfat samples were determined by olfactory test and HPLC, respectively. Cooked (initial cooking) prerigor meat was found to have higher (P < .05) pH and lower (P < .05) TBA values than comparable postrigor meat (6.44 vs 6.09 and 2.15 vs 3.23, respectively). Regression analysis indicated an inverse relationship between pH and TBA values (r = -.52; P < .01). No appreciable changes in TBA values were noted after frozen storage for 14 to 98 d, but reheating increased TBA values (P < .05) in both prerigor and postrigor samples (3.45 vs 4.32, respectively). Sensory evaluation scores indicated that prerigor cooked meat was less tender with more pronounced rancid flavor than postrigor cooked meat (P < .05), but panelists may have allowed the toughness of the prerigor samples to adversely affect their flavor scores. No difference in boar odor was detected between rigor states or breeds. Mean skatole concentration in backfat was .12 micrograms/g and no difference was detected between breeds.(ABSTRACT TRUNCATED AT 250 WORDS)