Effects of room-temperature exposure on bacterial growth in stored red cells

Experiments were performed to determine the effect of room-temperature (RT) exposure on the growth rates of selected bacteria by deliberate contamination of AS-1 packed red cell (RBC) units contained in PL146 plastic bags. Isolates of Staphylococcus aureus, S. epidermidis, Streptococcus faecalis, Pseudomonas aeruginosa, Citrobacter freundii, Enterobacter agglomerans, and Yersinia enterocolitica were inoculated into 3- to 5-day-old packed RBC units. The units were refrigerated at 4 to 6 degrees C for 14 days. On two occasions during this period, one-half of the units were removed from the refrigerator and held at 25 to 26 degrees C for 2 hours. Timed samples taken during the periods at RT revealed stable or decreasing bacterial counts in the majority of exposed units, and in no instance was a marked increase in bacterial growth observed. Samples taken after subsequent prolonged rerefrigeration showed no significant increase in bacterial counts as compared with those in control units that were refrigerated constantly. These results indicate that RT exposure of contaminated RBC units does not result in accelerated bacterial proliferation over a period of 2 hours and that it may, in fact, have a detrimental effect on bacterial growth.     

Radiologically guided balloon dilation of gastrointestinal strictures. Part II. Results of long-term follow-up

Balloon dilation catheters were used to treat 94 gastrointestinal strictures in 92 patients over a 6-year period. Long-term follow-up data were obtained for 80 of these patients, with a mean follow-up period of 389 days. Overall, of the patients who underwent a successful dilation procedure, 83% remained symptom free after 1 year, and 69% after 2 years. The location of the stricture did not significantly influence the long-term outcome, nor did procedure characteristics, aside from primary technical failure. Both patients with malignant strictures and those whose strictures were associated with an anastomosis were more likely than other patients to have recurrent symptoms.     

Twin gestations: monitoring of complications and anomalies with US

An evaluation of 227 consecutive twin gestations was undertaken to assess the role of ultrasound (US) in the diagnosis of major obstetric complications and congenital anomalies. US accurately depicted the growth and development of fetuses in 65 patients with underlying maternal disorders that produced additional risks to the pregnancy. Complications such as malpresentations (104 cases), polyhydramnios (15 cases), oligohydramnios (five cases), and uterine myomas (seven of 11 cases) were demonstrated prenatally with US. Fetal anomalies included anencephaly (two cases), hydrocephalus (two cases), conjoined twins (three cases), twin-twin transfusion syndrome (five cases), and acardiac monsters (two cases). Demise of one twin in 20 gestations and demise of both twins in 18 gestations (overall mortality of 17%) were correctly identified with US. These 38 gestations included intrauterine demise in 12, spontaneous abortion in 13, and neonatal deaths in 13. Therefore, when multiple gestations are suspected clinically, serial real-time US scans should be obtained beginning in the first trimester.     

Altersgrenze von 68 Jahren auch für Entlastungsassistenten (Anm.: L. Schauber)

Ohne Zusammenfassung     

An autologous blood program coordinated by a regional blood center: a 5- year experience

The Southern Arizona Regional Red Cross blood program offers preoperative autologous blood deposit to all patients and intraoperative autotransfusion services to all hospitals in the region. During a 5-year period, the amount of preoperatively deposited autologous blood and intraoperatively salvaged red cells available increased from 0.3 to 19.6 percent of the community's total collections. Further increases in the availability and use of autologous blood may be achieved by community-wide integration of services.     

Hematopoiesis on cellulose ester membranes. XI. Induction of new bone and a hematopoietic microenvironment by matrix factors secreted by marrow stromal cells

Cellulose ester membranes (CEM) were coated with stromal cells from bone marrow (BM) or bone and implanted intraperitoneally (IP) in CAF1 mice for intervals of 1 to 6 months. Previous studies indicated that matrix factors [glycoproteins (GPs), proteoglycans (PGs), and glycosaminoglycans (GAGs)] were secreted by the regenerating stromal cells and adsorbed by the CEM. After 1 to 6 months, the CEMs were removed, scraped free of adherent cells, and irradiated in vitro with 40 Gy. The scraped and irradiated CEMs were then reimplanted IP or subcutaneously (SC) for periods of 1 to 6 months in secondary syngeneic murine hosts. They were then removed for histologic study. CEMs reimplanted in SC sites developed bone and hematopoiesis as early as 1 month after implantation. Maximum hematopoiesis and bone formation was observed after 3 months. CEMs coated during the initial implantation with bone-derived stromal cells contained more bone and hematopoietic cells than did CEMs coated with marrow-derived stromal cells after SC implementation. Neither the CEMs coated with bone stromal cells nor those coated with marrow stromal cells developed new bone or trilineal hematopoiesis after being implanted IP. A few CEMs contained small foci of granulopoiesis only. We conclude that noncellular matrix substances deposited on CEMs by bone, and to a lesser degree by marrow cells, can induce prestromal cells in the SC tissues to produce a microenvironment suitable for trilineal hematopoiesis.     

Elevated 8-hydroxy-2'-deoxyguanosine levels in lung DNA of A/J mice and F344 rats treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and inhibition by dietary 1,4-phenylenebis(methylene)selenocyanate

1,4-Phenylenebis(methylene)selenocyanate (p-XSC) is an effective chemopreventive agent against 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanone (NNK)-induced lung adenoma in female A/J mice. While p-XSC can effectively inhibit NNK-induced DNA methylation in female A/J mice and in male F344 rats, its effect on NNK-induced oxidative DNA damage had not been determined. Thus, the effect of p-XSC on the levels of 8- hydroxy-2'-deoxyguanosine (8-OH-dG) in lung DNA from A/J mice and F344 rats treated with NNK was examined. Mice were given NNK by gavage (0.5 mg/mouse in 0.2 ml corn oil, three times per week for 3 weeks) or by a single i.p. injection (2 mg/mouse in 0.1 ml saline) while maintained on a control diet (AIN-76A) or control diet containing p-XSC at 10 or 15 p.p.m. (as Se) starting 1 week before NNK administration and continuing until termination. Mice were killed 2 h after the last NNK gavage in the multiple administration protocol or 2 h after the single i.p. injection. Treatment with NNK by gavage significantly elevated the levels of 8-OH-dG in lung DNA of A/J mice from 0.7 +/- 0.1 to 1.6 +/- 0.2 adducts/10(5) 2'-deoxyguanosine (dG) (P < 0.001), while dietary p- XSC (at 10 p.p.m. Se) prevented significant elevation of the levels of this lesion caused by NNK, keeping them at 0.9 +/- 0.1 adducts/10(5) dG (P < 0.003). Injection of NNK in saline also significantly increased the levels of 8-OH-dG in lung DNA of A/J mice from 1.2 +/- 0.6 to 3.6 +/- 0.8/10(5) dG adducts (P < 0.01), while dietary p-XSC (at 15 p.p.m. Se) kept these levels at 1.9 +/- 0.5 adducts/10(5) dG (P < 0.03). Rats were given a single i.p. injection of NNK (100 mg/kg body wt) in saline while being maintained on control diet (AIN-76A) or control diet containing p-XSC (15 p.p.m. as Se) starting 1 week before NNK administration and continuing until termination. The rats were killed 2 h after injection. Treatment with NNK using this protocol significantly elevated the levels of 8-OH-dG in lung DNA of F344 rats from 2.6 +/- 0.5 to 3.5 +/- 0.5 adducts/10(5) dG (P < 0.03), while dietary p-XSC (at 15 p.p.m. Se) kept the levels of this lesion at 2.2 +/- 0.6 adducts/10(5) dG (P < 0.01). Our findings suggest that the chemopreventive efficacy of p-XSC against NNK-induced lung tumorigenesis in A/J mice and F344 rats may be due in part to inhibition of oxidative DNA damage.      

Inhibition of N'-nitrosonornicotine-induced esophageal tumorigenesis by 3-phenylpropyl isothiocyanate

The ability of dietary isothiocyanates to inhibit the esophageal metabolism of N'-nitrosonornicotine (NNN) was examined in F344 rats. Following feeding of benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC), 3-phenylpropyl isothiocyanate (PPITC), 4- phenylbutyl isothiocyanate (PBITC) or 6-phenylhexyl isothiocyanate for 2 weeks, rats were killed and the esophagi were incubated in vitro with [5-3H]NNN. While dietary BITC, PEITC and PBITC all decreased NNN metabolism, dietary PPITC had the greatest effect, yielding inhibition ranging from 55 to 91% of the control production of various NNN metabolites. To determine the chemopreventive efficacy of PPITC on NNN- induced esophageal tumorigenesis, rats were fed AIN-76A diets containing 0, 1.0 or 2.5 micromol/g PPITC and were given untreated drinking water or drinking water containing 5 p.p.m. NNN. After 87 weeks, the experiment was terminated and the esophageal tumors were counted. Rats that were given untreated drinking water developed no tumors. Rats that were given 5 p.p.m. NNN and unadulterated AIN-76A diet had an esophageal tumor incidence of 71% and a multiplicity of 1.57 tumors/animal. The two dietary concentrations of PPITC reduced the incidence and multiplicity of NNN-induced esophageal tumors by >95%. These results demonstrate the remarkable chemopreventive efficacy of PPITC in the NNN-induced esophageal tumor model.