The combination of a potent vitamin D3 analog, EB 1089, with ionizing radiation reduces tumor growth and induces apoptosis of MCF-7 breast tumor xenografts in nude mice.

PURPOSE: The purpose of this research was to evaluate theinfluence of the combination of the vitamin D(3) analogue EB 1089 with fractionated radiation on growth and apoptosis of MCF-7 tumor xenografts in athymic mice. EXPERIMENTAL DESIGN: Four to six-week-old ovariectomized mice were injected s.c. with MCF-7 tumor cells suspended in Matrigel. When tumors reached a size of approximately 150-200 mm(3), animals were exposed to EB 1089 (45 pmols/day) for 8 days, whereas mice that were to be irradiated in the absence of EB 1089 received solvent (Solutol HS15). After the termination of EB 1089 and solvent administration, tumors were irradiated (3 x 5 Gy) over a period of 3 days using a 300 KV Pantax Therapax irradiator. Tumor growth was monitored for 25-30 days after the last dose of irradiation in a double-blind manner; tumor cellularity was assessed by H&E and trichrome staining, cell proliferation by Ki-67 staining, and apoptosis by terminal deoxynucleotidyltransferase-mediated nick end labeling assay. Rates of tumor regression were assessed using a mixed effects statistical model. RESULTS: A significantly higher rate of decline in tumor volume (7.5% per day) was observed in mice exposed to radiation subsequent to EB 1089 compared with animals treated with radiation alone (5.6% per day). Final tumor volumes in animals irradiated after EB 1089 were approximately 50% lower than in the group that received radiation alone. Loss of cellularity, a marked reduction in the fraction of proliferating cells, and the promotion of apoptosis confirmed that the combination of EB 1089 with radiation was significantly more effective than radiation alone in blocking tumor cell growth and promoting tumor cell death. CONCLUSIONS: This work demonstrates that EB 1089 can improve local tumor control by fractionated radiation, in part through the promotion of apoptotic cell death.     

Recurrence of extrahepatic biliary atresia in two half sibs.

Extrahepatic biliary atresia (EHBA) usually is a sporadic disorder. Familial cases, including occurrence in sibs and twins, have been reported. We report the first recurrence of EHBA in two half sibs born to a common father and unrelated mothers and suggest the possibility of gonadal mosaicism for a new dominant mutation.     

Magnetic resonance imaging of osteosarcoma

Early magnetic resonance (MR) experience in the evaluation of 14 consecutive long bone intramedullary osteosarcomas demonstrates the need for T1 and T2 weighted pulsing sequences in the staging of this disease. Intramedullary disease is best depicted by coronal T1 weighted pulsing sequences and subtle extra-compartmental discase by T2 weighted axial imaging. Both high intensity and low intensity intra-medullary signals were noted on T2 weighting, while all T1 weighted pulsing sequences showed intra-medullary disease to have low signal intensity. Extraosseous tumor on T2 weighting usually had a high signal, and disease extent was therefore sharply demarcated from uninvolved muscle and its relationship to vessels confidently assessed. MR appears optimally suited for local staging of osteosarcoma, further enhancing the role of radiology in planning limbsalvage surgical techniques.     

Effects of extracorporeal shock wave lithotripsy on the structure and function of rabbit kidney

An animal model was developed to investigate the effect of extracorporeal shock wave lithotripsy (ESWL) on a normal kidney. Rabbits were treated with 3,000 shock waves at 18 kV to each kidney. Blood and urine samples were collected daily before and after shock wave treatment. Serum levels of hemoglobin, creatinine, lactic dehydrogenase (LDH), creatinine phosphokinase (CPK), and total protein were determined. Urine determination of volume, total protein, hemoglobin, and creatinine were also made. All kidneys, after sacrifice, were subjected to histologic analysis. The average pre-treatment creatinine clearance of our rabbits was 8.3 ml./min. After the treatment, a significant (p less than 0.01) reduction in creatinine clearance was noted for four days. The reduction was to 0.61 ml./min. on day one, 0.87 on day two, 1.04 on day three, and so forth. Urine hemoglobin rose significantly (p less than 0.01) for the first three days from 0.0 to 1.5 gm./dl. Histologic examination at seven days showed focal subcapsular hemorrhage, tubular dilation, and interstitial hemorrhage. Histologic evaluation at two months revealed focal interstitial fibrosis. In conclusion, this study reveals that shock waves to the kidney have short term physiologic effects on renal function and permanent focal histologic effects, which do not effect long term physiologic function. Further research on the effects of ESWL on renal function and structure could be facilitated with the use of this model.     

Monocarboxylate 4 Mediated Butyrate Transport in a Rat Intestinal Epithelial Cell Line

Background

Short chain fatty acids (SCFA) are absorbed by carrier mediated uptake in the small intestine by pH-dependent SCFA/HCO₃ ^? exchangers on the apical membrane of epithelial cells. Conventional assumption is that MCT1 mediates SCFA/HCO₃ ^? exchange in the intestine. Further, due to the presence of multiple such anion exchangers, the identity of the intestinal SCFA/HCO₃ ^? has been controversial.

Aims

The aim of this study was to determine the identities of the butyrate transporter in the intestinal epithelial cells (IEC-18).

Methods

IEC-18 cells were treated with specific siRNAs for MCT1 and MCT4, and butyrate and lactate uptake studies were performed.

Results

Alpha-cyano-4-hydroxycinnamic acid inhibited lactate uptake but not butyrate uptake in IEC-18 cells, indicating that these two substrates are transported via two different transporter systems. MCT1 siRNA treatment abolished both MCT1 mRNA by more than 95 % and protein expression by 83 % as evidenced by RTQ-PCR and western blotting experiments. However, MCT1 siRNA treatment inhibited butyrate uptake upto 24 %, whereas it inhibited lactate uptake significantly by 70 %. Treatment with MCT4 siRNA inhibited MCT4 mRNA expression by 75 % and protein expression by 85 % in these cells. MCT4 siRNA inhibited butyrate uptake by 40 %. Further, several non-steroidal anti-inflammatory drugs (NSAIDs) are transported by the butyrate transporter. Finally, MCT4 siRNA inhibited salicylate uptake by 27 % indicating direct evidence for the transport of salicylate by MCT4.

Conclusions

These data indicate that MCT1 is the high affinity lactate transporter and MCT4 is the high affinity butyrate transporter in the intestinal epithelial cell line IEC-18.     

Evaluation of a vessel sealing system,bipolar electrosurgery,harmonic scalpel,titanium clips,endoscopic gastrointestinal anastomosis vascular staples and sutures for arterial and venous ligation in a porcine model

PURPOSE: We assessed the usefulness of the LigaSure (Valleylab, Boulder, Colorado) vessel sealing system for vascular control during laparoscopic surgery and compared it with other available hemostatic modalities. MATERIALS AND METHODS: A total of 31 domestic pigs were divided into 5 groups. In groups 1 and 2 the vessel sealing system was compared with titanium clips and Endo-GIA (United States Surgical, Stamford, Connecticut) staples. In group 3 the vessel sealing system was compared with standard Klepinger (Karl Storz, Culver City, California) bipolar forceps. In group 4 the harmonic scalpel and Trimax (United States Surgical) bipolar forceps were compared. In group 5 in vivo laparoscopic application of the vessel sealing system was evaluated. RESULTS: The 5 mm. laparoscopic vessel sealing system sealed arteries up to 6 mm. and veins up to 12 mm. in diameter at supraphysiological bursting pressure. We evaluated 13 arteries with a diameter of 6 mm. or less at a mean bursting pressure of 662 mm. Hg (range 363 to 1,985) and 11 veins with a diameter of 12 mm. or less with a mean bursting pressure of 233 mm. Hg (range 63 to 440). Collateral tissue damage extended 1 to 3 mm. from the application site. Standard bipolar energy with Klepinger and Trimax forceps was less reliable and in some cases vessel sealing could not be accurately assessed before vessel division. Collateral tissue injury was 1 to 6 mm. The harmonic scalpel did not reliably seal vessels larger than 3 mm. but resulted in the least acute collateral tissue injury of 0 to 1 mm. CONCLUSIONS: In the porcine model the LigaSure system is a viable option for laparoscopic management of arteries up to 6 mm. and veins up to 12 mm. in diameter.