Benzo[b]fluoranthene: tumorigenicity in strain A/J mouse lungs, DNA adducts and mutations in the Ki-ras oncogene

The polycyclic aromatic hydrocarbon benzo[b]fluoranthene (B[b]F)is a pervasive constituent of environmental combustion products.We sought to examine the lung tumorigenic activity of B[b]Fin strain A/J mice, to study the relationship between formationand decay of B[b]F-DNA adducts and to examine mutations in theKi-ras proto-oncogene in DNA from B[b]F-induced tumors. Micewere given i.p. injections of 0, 10, 50, 100 or 200 mg/kg bodywt and lung adenomas were scored after 8 months. B[b]F inducedsignificant numbers of mouse lung adenomas in a dose-relatedfashion, with the highest dose (200 mg/kg) yielding 6.95 adenomas/mouse, with 100% of the mice exhibiting an adenoma. In micegiven tricaprylin, the vehicle control, there were 0.60 adenomas/mouse,with 55% of the mice exhibiting an adenoma. Based on dose, B[b]Fwas less active than benzo[     

Inhibitation of pro-inflammatory cytokine gene expression and papilloma growth during murine multistage carcinogenesis by pentoxifylline

Topical application of 12-O-tetradecanoylphorbol-13-acetate(TPA) to the dorsal epidermis of Sencar mice induces synthesisof pro-inflammatory cytokines, including interleukin-1     

Gene expression and cellular sources of inducible nitric oxide synthase during tumor promotion

The present studies examined the temporal sequence of induciblenitric oxide synthase (iNOS) gene expression and the cellularsources of iNOS protein and of 3-nitrotyrosine, as a markerof production of nitric oxide-derived reactive nitrogen intermediatesduring murine multi-stage carcino-genesis. Levels of iNOS mRNAin dorsal skin isolated from acetone-treated female Sencar micewere 2.5-fold higher than iNOS gene expression detected in cutaneoustissue isolated from Sencar mice at 1,3,6,10,16 and 22 weeksafter exposure to a single topical application of 25 nmol 7,12-dimethylbenz[     

Fetal plasma and renal responses to ruminal fluid

Amniotic fluid homeostasis is dependent on a balance of fetal fluid production and absorption. The fetal gastrointestinal tract is believed to resorb 500 to 1000 ml of amniotic fluid per day during 7 to 10 bouts of swallowing activity. However, the impact of ruminal fluid on fetal plasma composition and fluid homeostasis is largely unknown. Seven ovine fetuses (120 +/- 1 day) received intraruminal infusions of 0.9% or 3% saline solution on alternate days. In response to successive 40-minute intraruminal infusions of 0.9% saline solution (0.5 and 1.0 ml/kg/min), there was no change from basal levels of fetal plasma osmolality (295.7 +/- 2.9 mosm), plasma arginine vasopressin (1.45 +/- 0.29 pg/ml), urine osmolality (150 +/- 8 mosm), or urine volume (0.49 +/- 0.10 ml/min). In response to the 3% saline solution infusion, significant increases were noted in fetal plasma osmolality (295.4 +/- 3.1 to 302.6 +/- 2.6 mosm), plasma arginine vasopressin (1.77 +/- 0.31 to 4.84 +/- 0.79 pg/ml), and urine osmolality (157 +/- 13 to 342 +/- 25 mosm), whereas fetal urine volume significantly decreased (0.35 +/- 0.05 to 0.15 +/- 0.06 ml/min). These results indicate that hypertonic, but not isotonic, saline solution infusion into the fetal gastrointestinal tract may affect fetal plasma composition and urine production. Under conditions of significant plasma to luminal osmotic gradients, fetal gastrointestinal water and electrolyte transfer may be more rapid than can be compensated by either fetal renal function or placental equilibration.     

Early experience with the selective splenocaval shunt for variceal bleeding

Selective variceal decompression is the operative method of choice in the definitive management of recurrent hemorrhage from gastroesophageal varices. The distal splenorenal shunt is the recommended procedure for selective variceal decompression, but its use may be limited in patients who have undergone left nephrectomy, in patients with an anatomically aberrant relationship between the splenic and left renal veins and in patients with preoperative visceral angiographic findings suggesting that they are at risk for development of the postoperative syndrome of renal vein hypertension. In these clinical situations, selective variceal decompression can be obtained with a splenocaval shunt, constructed by directly anastomosing the splenic vein to the infrarenal vena cava. Seven patients who have undergone the selective splenocaval shunt are reviewed in this report. Early experience with these patients demonstrates the use of the selective splenocaval shunt when an alternative to the distal splenorenal shunt is needed.     

Fetal Renal Vein Thrombosis

Two cases of fetal renal vein thrombosis, diagnosed via maternal ultrasound scan are presented. One was associated with severe placental dysfunction and demonstrated haematuria and renal failure which resolved on day 10. The other followed an antepartum haemorrhage and resolved before the baby was born. The ultrasound showed, as transient findings, unilateral renal enlargement, thrombus protruding into the inferior vena cava, and mild fetal ascites. We suggest that fetal renal vein thrombosis may be more common than previously suspected, and warrants close monitoring of fetal well-being. Delivery should be considered if there is other evidence of fetal compromise, if the amount of peritoneal fluid suggests substantial haemorrhage, or if there is propagating thrombus in the inferior vena cava.     

Body fluid compartment changes following cardiopulmonary bypass in dogs

To investigate whether pulsatile perfusion affects postoperative edema, we examined weight, total body water (TBW), and extracellular fluid (ECF) following cardiopulmonary bypass (CPB) in dogs using three different perfusion systems. Fourteen dogs were divided into three groups differing only in the perfusion system used: Sarns nonpulsatile and pulsatile roller pumps and a University of Texas pulsatile pump. Weight, TBW, and ECF were measured preoperatively and on postoperative days (POD) 1, 3, and 7. No significant differences were seen in body weight, TBW, or ECF between groups. Body TBW (percent of body weight) rose significantly (P=0.005) to 72% on POD 3 and 7. ECF (percent of body weight) rose to 58% by POD 7 (P=0.008). These three perfusion systems produced no differences in the pattern of postoperative body fluid distribution after CPB, suggesting that there is no advantage to pulsatile perfusion for the purpose of decreasing postoperative edema.     

Serologic diagnosis of whooping cough by enzyme-linked immunosorbent assay

Pernasal swabs were obtained on 3 consecutive days from 146 children referred for hospital admission with suspected whooping cough, and immunoglobulin A and immunoglobulin M antibodies to Bordetella pertussis were measured by enzyme-linked immunosorbent assay. The clinical features in 113 of the children were considered consistent with the diagnosis. Sixty-four cases were confirmed by serology, which showed a greater sensitivity (57% vs. 35%) than pernasal swab culture with no loss of specificity (100%). Paired serum samples were necessary for diagnosis in 30 (47%) of these 64 cases. Seventeen (43%) of 40 cases confirmed by pernasal swab culture had negative serologic results. Most of these were young infants who showed a less reliable antibody response. Detection of antibodies to B. pertussis by enzyme-linked immunosorbent assay can be a valuable additional test in the differential diagnosis of whooping cough but is not appropriate as the sole diagnostic test.     

PROLONGED PREGNANCY AND THE BIOPHYSICAL PROFILE A Birthing Center Perspective

A triage system for antepartum surveillance of postdates pregnancy is studied in a busy, indigent care service with limited resources for in-hospital delivery. One hundred seventy-eight pregnancies (13.2% of the total population) were thought to be at least 42 weeks' gestation by clinical criteria, and 128 of these underwent at least one complete biophysical profile within seven days of delivery. We find no statistically significant difference in the incidence of meconium staining, fetal distress in labor, or low Apgar scores when either the high or low scoring groups are compared, or when compared with the 50 patients who delivered without a biophysical evaluation. Specific components of the testing schema, however, namely oligohydramnios and spontaneous decelerations on the nonstress test, are highly associated with adverse perinatal events. Of the total population thought to be postmature clinically, only 60 infants (33.9%) were actually beyond 42 weeks' gestation by Dubowitz scoring. We conclude that a modified biophysical assessment as described is easily performed in a nontertiary care setting where a CNM-MD team approach is applied and may help to differentiate patients who require expeditious termination of pregnancy in-hospital from those who can be managed expectantly in the birthing center.