Urine catalytic iron and neutrophil gelatinase-associated lipocalin as companion early markers of acute kidney injury after cardiac surgery: a prospective pilot study.

BACKGROUND: Open heart surgery with cardiopulmonary bypass is recognized as a common cause of acute kidney injury (AKI). The conventional biomarker creatinine is not sensitive enough to detect AKI until a significant decline in renal filtration has occurred. Urine neutrophil gelatinase-associated lipocalin (NGAL), part of an acute response to the release of tissue iron from cells, is an early biomarker and a predictor of AKI in a variety of clinical settings. We sought to evaluate the relationship between urine catalytic iron (unbound iron) and NGAL over the course of AKI due to cardiac surgery. METHODS: FOURTEEN PATIENTS WHO UNDERWENT OPEN HEART SURGERY HAD THE FOLLOWING MEASURED: serum creatinine (0, 12, 24, 48 and 72 h postoperatively), urine NGAL and urine catalytic iron (0, 8, 24 and 48 h postoperatively). Urine NGAL and urine catalytic iron were quantified by immunoassay and bleomycin-detectable iron assay, respectively. AKI was defined by the Acute Kidney Injury Network (AKIN) criteria. RESULTS: Urine catalytic iron increased significantly (p < 0.05) within 8 h and peaked at 24 h postoperatively in patients who developed AKI (n = 8, baseline 101.96 ± 177.48, peak 226.35 ± 238.23 nmol/l, p = 0.006), but not in non-AKI patients (n = 6, baseline 131.08 ± 116.21, peak 163.99 ± 109.62 nmol/l, p = 0.380). Urine NGAL levels also peaked at 24 h with significant increase observed only in AKI patients: AKI - baseline 34.88 ± 26.47, peak 65.50 ± 27.03 ng/ml, p = 0.043; non-AKI - baseline 59.33 ± 31.72, peak 71.00 ± 31.76 ng/ml, p = 0.100. The correlation between baseline levels of urine catalytic iron and NGAL and peak levels of urine catalytic iron and NGAL was r = 0.86, p < 0.0001. CONCLUSION: Urine catalytic iron appears to rise and fall in concert with NGAL in patients undergoing cardiac surgery and may be indicative of early AKI. Future research into the role that catalytic iron plays in acute organ injury syndromes and its potential diagnostic and therapeutic implications is warranted.

Water as a contrast medium: a re-evaluation using the multidetector-row computed tomography.

Water as an intraluminal negative contrast medium produces improved image quality with reduced artefact. However, rapid absorption of oral water in the bowel relative to speed and timing of image capturing has limited its clinical application. These findings predate advances in multidetector-row computed tomography (CT). To re-evaluate differences in image quality, we studied image clarity and luminal distention between the same group of patients who received both a pancreas protocol CT (PPCT) that uses oral water and a conventional positive oral contrast scan. We reviewed 66 patients who had previously undergone both a PPCT and an oral contrast abdominal CT. CT images were independently reviewed by two board-certified radiologists who scored degree of hollow viscus distention and visualization of mural detail using a Likert 5-point scale. Results were evaluated by using the Wilcoxon-signed rank test. Student's t test was applied to evaluate the differences in radiation dosage and Spearman's correlational test was used to evaluate interrater correlation between the radiologists. In comparing the mean radiation dosage, there was no statistical difference between the two protocols, and there was good interrater association with ratios of 0.595 and 0.51 achieved for the PPCT and conventional oral scan, respectively. The Wilcoxon signed-rank test showed statistical differences in the stomach (P < 0.001) for both clarity (P < 0.001) and distention (P < 0.001), the duodenum for both clarity (P < 0.001) and distention (P = 0.02), and the ileum for distention (P = 0.02) with the PPCT having a better median score for organ clarity in the stomach and duodenum and better luminal distention in the stomach, equal distention in the duodenum, and slightly worse distention in the ileum. For the remainder of the bowel and organs evaluated, there was no statistically significant difference in the ratings between the two protocols. Using present CT scan technology, water can be an effective contrast medium causing better or equal distention in the bowel and better or equal clarity than routine barium contrast. This calls for a need to reconsider the use of water as a contrast medium in clinical practice.

A true orthotopic gastric cancer murine model using electrocoagulation.

BACKGROUND: Orthotopic mouse models of human gastric cancer represent an important in vivo tool for testing chemotherapeutic agents and for studying intraluminal factors. Currently, orthotopic mouse models of gastric cancer require an operative procedure involving either injection or implantation of tumor cells in stomach layers. The resultant tumor does not grow from the stomach's mucosal surface, so it does not mimic the human disease process. STUDY DESIGN: A low-dose gastric mucosal coagulation was done transorally in the body of stomach using a specially designed polyethylene catheter in 16 female severe combined immunodeficient mice. This was followed by the instillation of SNU-16 human gastric cancer tumor cells (1 × 10(6) cells). Five mice each were euthanized at 1 and 2 months, and 6 mice were euthanized at 3 months. Three control mice underwent electrocoagulation alone and 3 mice underwent cell line instillation alone. RESULTS: Tumors were detected in 11 of 16 experimental mice, but not in the control mice. Tumors were noted in mice at 1 month. Over time, there was an increase in tumor growth and metastasis to lymph nodes and surrounding organs. Histopathologic evaluation showed that the tumors grew from the gastric mucosa. CONCLUSIONS: Our model is easy to create and overcomes the limitations of the existing models, as the tumor arises from the stomach's mucosal layer and mimics the human disease in terms of morphology and biologic behavior. This is the first report of a true orthotopic gastric cancer murine model. This model opens new doors for additional studies that were not possible earlier.

Intratumoral acetic acid injection eradicates human prostate cancer tumors in a murine model.

INTRODUCTION: To treat localized prostate cancer without substantial morbidity, an ideal treatment would be an effective local therapy with minimal morbidity. Direct injections have been used to treat benign prostatic hyperplasia without major complications, but in limited cases. We evaluated the local oncotoxic effects of acetic acid in a prostate cancer xenograft murine model. MATERIALS AND METHODS: PC3 and LNCaP human prostate cancer cell lines were used to grow subcutaneous tumors in SCID mice. For each cell line, 14 mice underwent intratumor injection with 25% acetic acid (0.05 ml/100 cm3 of tumor) after the tumor was >300 mm3. Post-treatment one mouse/group was euthanized after 2 h, 24 h, 1 and 2 weeks; remaining mice (n = 10) were killed at 120 days. Control mice (8/group) were euthanized after they met the humane criteria for tumor burden and overall health. RESULTS: Tumor necrosis was noted immediately post-injection; by 24 h, ulceration and crusting of overlying skin were noted, which healed into scars by 23 ± 5 days. Histological examination showed tumor degeneration and necrosis with blood vessel obstruction. Ten treated mice in both groups survived for 120 days, which was much longer than the mean survival of PC3 (40 ± 9 days) and LNCaP (56 ± 10) control mice. CONCLUSIONS: Direct injection of acetic acid successfully eradicated both tumors. This treatment option could potentially be used in humans for treatment of early localized prostate cancer and nonoperative management of locally advanced cases. This is the first report of successful local chemical therapy for prostate cancer.

The expression of interferon receptor α/ß in human pancreatic cancer in nude mice is essential for tumor response to interferon α treatment.

BACKGROUND: Adjuvant interferon based chemoradiation has rendered promising results against pancreatic cancer. This study evaluated the in vivo effect of interferon α on two human pancreatic carcinoma cell lines implanted in nude. MATERIAL AND METHODS: MiaPaCa-2 expressed the interferon α/ß receptor and Panc-1 cells did not. Regimen I consisted of intraperitoneal single-agent gemcitabine and Regimen II consisted of IFN-α and gemcitabine biweekly for 30 d. RESULTS: Regimen I and II significantly decreased median tumor volume compared with control mice (P < 0.001). However, MiaPaCa-2 showed a more dramatic response to Regimen II compared with Panc-1 implanted mice. MiaPaCa-2 and treated with Regimen II showed less metastasis and less local invasion compared with Panc-1 treated with same regimen. Regimen II was more effective on MiaPaCa-2 compared with Regimen I (P < 0.001). There were no differences between Regimens I and II in the Panc-1 group. CONCLUSIONS: Treatment of human pancreatic cancer in nude mice with interferon α and gemcitabine was associated with a reduction in tumor volume. This process was more prominent in the cells that express the interferon receptors.

A novel nonoperative orthotopic colorectal cancer murine model using electrocoagulation.

BACKGROUND: Orthotopic mouse models of human colorectal cancer represent an important in vivo tool for testing chemotherapeutic agents and studying intraluminal factors that may alter the growth of cancers. Currently the orthotopic mouse models of colorectal cancer require either an operative procedure or creation of colitis to implant the cancer cells in rectum. We have developed a nonoperative, minimally invasive technique to create a true orthotopic colon cancer mouse model. STUDY DESIGN: We used human (LS 174T and HT-29) and murine (CRL-2638 and CRL-2639) colon cancer cell lines. Low-dose mucosal coagulation was performed transanally using a specially designed electrode at 1 to 3 predetermined points, 2 to 3 cm from the anus, followed by a transanal instillation of tumor cells (1 × 10(6) cells) in 12 female nude or severe combined immunodeficiency disease mice for each of the 4 groups (n = 48, plus 16 controls). Mouse colonoscope (Coloview) and microCT were used to follow tumor growth. Four mice from each group were euthanized at 1, 2, and 3 weeks. RESULTS: Tumors were detected in 12 of 12 of the CRL-2638, 11 of 12 of the CRL-2639, 7 of 12 of the HT-29 and 12 of 12 mice in the LS 174T groups. Histopathologic evaluation showed that the tumors grew from the colonic mucosa. CRL-2638 and LS 174T exhibited better implantation, faster tumor growth, larger tumor volume, and earlier metastases. MicroCT detected tumors larger than 3 mm, and the colonoscopy detected tumors larger than 1 mm. CONCLUSIONS: Our mouse model is minimally invasive and easy to create and overcomes the limitations of existing models while mimicking the human disease in terms of morphology and biologic behavior. This model opens the doors for colon cancer oncologic studies in an animal model that were previously not possible.

Seeing the trees in the forest: selective electroporation of adipocytes within adipose tissue.

Electroporation has been recently adapted for the transfer of macromolecules into cells of tissues in vivo. Although mature adipocytes constitute <20% of cells residing in adipose tissue, we hypothesized that fat cells might be susceptible to selective electrotransfer of plasmid DNA owing to their large size relative to other cells in the tissue. Results demonstrate the feasibility of electroporating DNA into mature fat cells with >99% selectivity over other cells in the tissue. Further experiments used the "adiporation" technique to image the subcellular targeting of fluorescent bioreporter molecules to the nucleus, mitochondria, and lipid droplets of adipocytes within intact adipose tissue. Finally, we utilized fluorescent bioreporters to examine the effects of constitutive activation of the beta-adrenergic signaling pathway in adipocytes. These results demonstrate that overexpression of rat beta1-adrenergic receptors alters the cellular morphology of white adipocytes in a fashion that mimics the effects of systemic infusion of beta3-adrenergic receptor agonists. Hallmarks of the altered morphology include pronounced fragmentation of the single lipid droplet, repositioning of the nucleus, and induction of mitochondrial biogenesis. These results indicate that activation of beta-adrenergic signaling within adipocytes is sufficient to induce a phenotype that resembles typical brown adipocytes and suggest that in vivo electroporation will allow molecular dissection of the mechanisms involved.

Prenatal cocaine exposure influences the growth and life span of laboratory rats.

Laboratory rats prenatally exposed to alcohol, nicotine, amphetamine, undernutrition or hypoxia can exhibit shortened life span and other signs of enhanced age-related degeneration. We evaluated the possibility of similar effects following prenatal cocaine exposure. Pregnant rats received 20 or 40 mg/kg cocaine HCl subcutaneously (C20, C40), twice daily, from gestation days (GD) 7-20. Untreated control (UTC) and pair-fed control (PFC) groups were also used. The pregnant C40, C20, and PFC dams ate less food and gained less weight than the UTC dams did. The pregnant C40 and C20 dams drank more water than the UTC dams did, and the pregnant PFC dams drank less than the UTC dams did. The C40 and PFC offspring had delayed earflap openings. The C40 male and female offspring had lower birth weights than their cohorts in the other three groups. The C40 female and male offspring remained significantly underweight until postnatal day (PND) 28 and PND56, respectively. During young adulthood, the males and females in the C20, C40, and PFC groups had normal body weights. During old adulthood, however, the C20 and C40 males and the C20, C40, and PFC females developed reduced body weights as compared with their UTC cohorts. The C20 and C40 male offspring and the C20, C40, and PFC female offspring also had life spans that were 7-12% shorter than that of their UTC cohorts. Thus, groups that showed reduced body weights in old age also showed shorter life spans. These results provided converging evidence that prenatal cocaine exposure caused enhanced age-related degeneration. Observations on cardiac and other organ pathology were also made. Health implications for children born to cocaine-abusing women are discussed.

Effects of Prenatal Cocaine on Hearing, Vision, Growth, and Behaviora.

The illicit use of cocaine has increased dramatically over the last 10-12 years. There has been a corresponding increase in cocaine abuse among obstetric patients and in the number of "cocaine babies." According to some estimates, these children make up more than half of the drug-associated births. This problem is therefore a major public health concern. Consequently, our laboratory investigated the effects of prenatal cocaine exposure on hearing, vision, growth, and exploratory/stress behavior. This chapter summarizes the literature on animals and humans on these topics and presents new observations from our laboratory. In terms of maternal toxicity, prenatal cocaine exposure causes hypertension, placental abruption, spontaneous abortion, poor pregnancy weight gain, and undernutrition secondary to appetite suppression. Some offspring effects include in utero growth retardation, cephalic hemorrhage, fetal edema, altered body composition, congenital malformations, and even pre- and postnatal death. The offspring can also exhibit a variety of behavioral, visual, hearing, and language disorders. Differential effects of animal strain and late gestational cocaine exposure are discussed. Comparisons are made between prenatal cocaine, the fetal alcohol syndrome, and the effects of prenatal undernutrition. Recommendations for clinical assessment and intervention are made.