Vitamin D3 analog, EB1089, inhibits growth of subcutaneous xenografts of the human colon cancer cell line, LoVo, in a nude mouse model

PURPOSE: In this study, we investigated the effect of the vitamin D ₃ analog, EB1089, on the growth of subcutaneous xenografts of the human colon cancer cell line, LoVo, in a nude mouse model. METHODS: BALB/c Nu/Nu nude mice were inoculated subcutaneously with 10 ⁶ LoVo cells. EB1089 dissolved in isopropanol was administered intraperitoneally and orally on alternate days at doses of 0.1, 0.5, and 2.5 g/kg/day. Control animals received isopropanol alone. Tumor volumes estimated using the formula 0.5×length×(width). The tumor kinetic index was determined by immunohistochemical detection of proliferating cell nuclear antigen. RESULTS: Significant dose-dependent inhibition of tumor growth was seen. After 20 days of treatment with 0.1 g/kg/day EB1089, mean tumor volume in treated mice was 41 to 49 percent less than that in control animals (P <0.01). Significant inhibition of tumor growth was also seen with 0.5 g/kg/day EB1089 after 22 days of treatment (51 percent of control P <0.01). Treatment with 2.5 g/kg/day resulted in weight loss that required termination of this group; these mice were subsequently found to be hypercalcemic. The tumor kinetic index was significantly lower in tumors treated with 0.1 g/kg/day EB1089 compared with that for control tumors (8 vs.30 percent in controls). CONCLUSION: These findings suggest that the vitamin D ₃ analog, EB1089, is a potent antiproliferative agent for some human colon cancers.The human colonic adenocarcinoma cancer cell line, LoVo, was a gift from CRC Laboratories, Nottingham, United Kingdom.Read at the Royal Australasian College of Surgeons Annual Scientific Congress, Melbourne, Australia, June 5 to 10, 1996.     

High incidence of false positives by a latex agglutination test for the diagnosis of Clostridium difficile associated colitis in compromised patients

Detection of Clostridium difficile cytotoxin using cell culture assays for the diagnosis of antibiotic-associated colitis has been used for over a decade. Because the methodology is time consuming and cumbersome, a recently introduced commercial latex agglutination (LA) kit has attracted much attention. We compared the sensitivity and specificity of this method with the cytotoxic assay (CTA) using diarrheal stools from 652 patients at a referral tertiary care center. Specimens from 71 (10.9%) patients were found positive with CTA and 98 (15%) by LA. Of these, 67 stools were positive by both methods. Four specimens showed cytotoxicity but were negative by LA. Of the 31 patient specimens that were positive by LA but negative by CTA, 22 were obtained from leukemic bone marrow transplant and four from renal transplant patients [corrected]. Sixteen of these patients had Giardia lamblia (four), Salmonella enteritidis (three), Blastocystis hominis (five), Rotavirus (two), and Shigella boydii (two) in their stools [corrected]. No significant organisms were found in the rest of the LA-positive and CTA-negative specimens.     

Urinary Biomarkers in the Clinical Prognosis and Early Detection of Acute Kidney Injury

Background and objectives: Several novel urinary biomarkers have shown promise in the early detection and diagnostic evaluation of acute kidney injury (AKI). Clinicians have limited tools to determine which patients will progress to more severe forms of AKI at the time of serum creatinine increase. The diagnostic and prognostic utility of novel and traditional AKI biomarkers was evaluated during a prospective study of 123 adults undergoing cardiac surgery.Design, setting, participants, & measurements: Urinary neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (CyC), kidney injury molecule-1 (KIM-1), hepatocyte growth factor (HGF), π-glutathione-S-transferase (π-GST), α-GST, and fractional excretions of sodium and urea were all measured at preoperative baseline, postoperatively, and at the time of the initial clinical diagnosis of AKI. Receiver operator characteristic curves were generated and the areas under the curve (AUCs) were compared.Results: Forty-six (37.4%) subjects developed AKI Network stage 1 AKI; 9 (7.3%) of whom progressed to stage 3. Preoperative KIM-1 and α-GST were able to predict the future development of stage 1 and stage 3 AKI. Urine CyC at intensive care unit (ICU) arrival best detected early stage 1 AKI (AUC = 0.70, P < 0.001); the 6-hour ICU NGAL (AUC = 0.88; P < 0.001) best detected early stage 3 AKI. π-GST best predicted the progression to stage 3 AKI at the time of creatinine increase (AUC = 0.86; P = 0.002).Conclusion: Urinary biomarkers may improve the ability to detect early AKI and determine the clinical prognosis of AKI at the time of diagnosis.Acute kidney injury (AKI) is a common and serious complication of cardiothoracic surgery (1); depending on the definition of AKI used, it may occur in over 40% of adults, with 1% to 5% requiring renal replacement therapy (RRT) (2–9). Recently, standardized clinical definitions of AKI have been implemented through the use of the RIFLE (Risk, Injury, Failure, Loss, and ESRD) and AKIN (Acute Kidney Injury Network) criteria (10,11). However, these criteria are still very much dependent on delayed serum creatinine elevations, the current gold standard for the diagnosis of AKI. Furthermore, as a functional marker of glomerular filtration, serum creatinine is not ideally suited to diagnose AKI caused by renal tubular injury, rather than reversible prerenal azotemia (10).In recent years, several novel human biomarkers have been demonstrated to detect acute tubular injury and have shown promise in their ability to precede and/or complement serum creatinine in the diagnosis of AKI (12–15). Cardiac surgery has long been used to study AKI because of the ability to prospectively follow patients before and after a well timed renal insult; for this reason, several urinary proteins have been shown to serve as biomarkers of AKI after cardiac surgery, including neutrophil gelatinase-associated lipocalin (NGAL) (16–20), cystatin C (CyC) (19,21), kidney injury molecule-1 (KIM-1) (18,21), interleukin-18 (IL-18) (22), and α-glutathione-S-transferase (α-GST) (23,24). Limited data are available comparing the ability of these markers to predict renal outcomes at the time of AKI diagnosis. In fact, nephrologists have limited tools in their arsenal to assess the presence and severity of renal tubular injury at the time of AKI diagnosis. Although urinalysis with microscopy has been shown to be of some utility in the differential diagnosis of AKI in a generalized hospital-based cohort (25), data supporting its use in the specific setting of cardiac surgery are lacking (24). Similarly, diagnostic mainstays of AKI evaluation such as the fractional excretion of sodium (FENa) have long been shown to be suboptimal tools in the complex setting of cardiac surgery AKI (24), in which volume status, fluid responsiveness, and diuretic use confound inferences regarding the relationship between tubular function and injury (26,27). Additionally, although recent data support the utility of the fractional excretion of urea (FEUrea) as a diagnostic tool in AKI (28), not all data support its use (29). Furthermore, very little is known about the utility of FENa or FEUrea compared with the novel urinary biomarkers discussed above for the differential diagnosis and prognostic evaluation of AKI.In this study, we assessed the diagnostic utility of urinary NGAL, CyC, KIM-1, hepatocyte growth factor (HGF), α-GST (a proximal tubular damage marker), π-GST (a marker specific to distal tubule damage), FENa, and FEUrea as biomarkers for the detection of early and severe AKI after adult cardiac surgery. These novel biomarkers can be thought of as falling into two categories: constitutive markers (proteins/enzymes that are normally present in renal tubular cells and not normally found in the urine in significant concentration but are released into the urine in direct response to cellular injury), and inducible biomarkers (proteins that are not normally found in high concentrations in renal tubular cells or urine until their production is directly upregulated in response to cellular injury). CyC, α-GST, and π-GST are constitutive proteins that are extruded into urine in the presence of site-specific renal tubular injury (CyC and α-GST are proximal and π-GST is distal); intracellular GSTs are released into urine by damaged tubular cells, whereas injured proximal tubules fail to reabsorb filtered CyC. In contrast, KIM-1 and NGAL are inducible biomarkers, gene products that are increased in direct response to nephron damage (30,31). We also evaluated the ability of these markers to predict the severity/stage of AKI at the time of clinical diagnosis by serum creatinine increase. We performed all of the above analyses for those subjects who developed AKI as defined by the AKIN (11). Recent data demonstrate that urine NGAL after cardiac surgery varies with baseline renal function (32); as such, a secondary analysis of baseline GFR was conducted for the aforementioned panel of biomarkers (32). Finally, we interpreted the data for all novel biomarker concentrations adjusted and unadjusted for dilution by indexing to urinary creatinine, but for brevity''s sake, we only report the indexed values unless otherwise noted.     

Cigarette smoking and the risk of colorectal cancer among men: a prospective study in Japan.

The association between cigarette smoking and the risk of colorectal cancer remains controversial. We examined this association using a population-based prospective cohort study in Miyagi, Japan. In 1990, we delivered a self-administered questionnaire on cigarette smoking and other health habits to 25 279 men who were 40-64 years of age and lived in 14 municipalities of Miyagi Prefecture. A total of 22 836 men responded (90.3% response rate). During 7 years of follow-up (158 376 person-years), we identified 188 patients of colorectal cancer. Relative risks and 95% confidence intervals were estimated by the Cox proportional-hazards regression analysis with adjustment for potential confounders. The multivariate-adjusted relative risks (95% confidence interval) of colorectal cancer for past smokers and current smokers compared with those who had never smoked were 1.73 (1.04-2.87) and 1.47 (0.93-2.34), respectively. Among current smokers, both a higher number of cigarettes smoked per day and an earlier age at which smoking had started were associated with a significant linear increase in risk (P for trend <0.05). Our findings are consistent with the hypothesis that cigarette smoking is associated with a higher risk of colorectal cancer in men.     

Hypocalcemia and hyperphosphatemia in severely dehydrated children with and without convulsions

Tetanic convulsions are not uncommon among severely dehydrated children in the developing countries. This raises the question whether these children have disturbances in the homeostasis of divalent ions. Serum values are reported of calcium, magnesium, phosphorus, sodium and potassium, as well as blood pH in children below 3 years of age with acute watery diarrhoea and with an estimated weight loss of about 10%. The study was performed on dehydrated children with (DC) or without (D) convulsions. Values were obtained on admission and following rehydration therapy (RT). On admission serum calcium was low in both D and DC children. Serum phosphorus was likewise elevated in both D and DC children. Serum magnesium was slightly elevated in the DC but not in the D group. No patient had hypernatremia. During RT, serum calcium increased significantly and serum phosphorus decreased significantly in D and DC children. Serum calcium showed a significant inverse correlation with serum phosphorus and a significant direct correlation with blood pH. Treatment of DC children with i.v. calcium and i.m. magnesium had no immediate effect on the convulsions. Our conclusion is that severely dehydrated children will develop hypocalcemia. The cause may be a redistribution of calcium into the cells, parallelled by a redistribution of phosphorus from the intra- to the extracellular space.     

Menstrual regulation and contraception in Bangladesh: Competing or complementary?

To examine the relationship between menstrual regulation (MR) and subsequent use of contraception in Bangladesh, we studied the birth control practices of a 6-month cohort of 4359 family-planning acceptors in a family-planning clinic in Dacca. We compared their use of birth control measures before and after MR. We attempted to examine the subsequent pregnancy and induced-abortion rates of 1671 of these women through a 3-year non-concurrent prospective study. Of those 1172 made their first visit to the clinic to obtain an MR and the remaining 499 women, who served as a comparison group, made their first visit to obtain contraceptive services not associated with MR. Three years' followup data were available for 558 women in the MR group and 228 women in the comparison group. Based on these data, the 3-year pregnancy rate for the MR group was 37.6/100 women and the induced abortion rate was 4.3/100 women. The 3-year pregnancy rate for the comparison group was 39/100 women and the induced abortion rate was 3.5/100 pregnancies. Thus, during a 3-year period women in the MR group did not obtain abortions significantly more often than women in the comparison group.     

Myocardial function in hearts with transgenic overexpression of the G protein-coupled receptor kinase 5

BACKGROUND: Chronic heart failure is associated with impairment of the myocardial beta-adrenergic receptor (beta-AR) system. In this study, the effects of G protein-coupled receptor kinase 5 (GRK5) overexpression on myocardial performance were directly assessed in the hearts of transgenic mice using an isolated work-performing murine heart preparation and computerized analysis of functional data. METHODS: A controlled experimental study was performed to evaluate cardiac function in both transgenic mice with a 30-fold overexpression of GRK5 (n = 9, 23 to 29 g) and littermate controls (n = 10, 22 to 29 g). Preload-dependent cardiac output, contractility, stroke work, stroke volume, and heart rate were compared between the two groups. RESULTS: Significant decreases in preload-dependent cardiac output and contractility were observed in the mice with GRK5 overexpression when compared with control group mice and occurred in association with significant decreases in stroke work and stroke volume. There was no significant difference in the average heart rate between the two groups. CONCLUSIONS: These data suggest that GRK5 upregulation may be partially responsible for alterations in myocardial function in chronic heart failure.