Phase II trial of CDK4/6 inhibitor palbociclib in advanced sarcoma based on mRNA expression of CDK4/ CDKN2A

Cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors demonstrated activity in terms of progression-free survival (PFS) in advanced dedifferentiated liposarcoma (DD-LPS), a sarcoma with CDK4 amplification. CDK4 overexpression is by far more common than amplification in sarcomas and it might be a rational target for CDK inhibitors. Preclinical investigators of this study found that CDK4 overexpression, while not of CDKN2A, was the most consistent predictive factor for palbociclib efficacy in sarcomas. Advanced adult-type soft-tissue sarcoma, excluding DD-LPS, or bone sarcoma patients, progressing after at least one systemic line, whose tumors overexpressed CDK4, but not CDKN2A at baseline biopsy, were accrued in this single-arm phase II trial (EudraCT number: 2016-004039-19). With the main endpoint of a 6-month PFS rate, 40% was considered promising in this population. Palbociclib was administered orally at 125 mg/day for 21 days in 28-day cycles. A total of 214 patients with 236 CDK4/CDKN2A determinations were assessed for prescreening, archival material (141), and screening, baseline biopsy (95). There were 28 (29%) with favorable mRNA profiles from 95 screened patients at baseline. From 23 enrolled patients, 21 evaluable, the 6-month PFS rate was 29% (95% CI 9-48), and there were 6 patients out of 21 with a PFS longer than 6 months. The median PFS and overall survival were 4.2 (95% CI 3.6-4.8) and 12 (95% CI 8.7-15.4) months, respectively. Translational research showed a significant correlation between CDK4 mRNA and protein expression. Palbociclib was active in a variety of sarcoma subtypes, selected by CDK4/CDKN2A, and deserves further investigation in the sarcoma context.

A phase II trial of weekly nab-paclitaxel for progressive and symptomatic desmoid tumors

Desmoid fibromatosis (DF) are mesenchymal neoplasms, with potential aggressive course and relevant clinical impact. New systemic therapy modalities are needed in this symptomatic/progressive population. In this multicenter, phase II trial (NCT03275818), patients with symptomatic/progressing DF received three cycles of weekly nab-paclitaxel. Brief pain inventory short form (BPI-SF) was collected at baseline and in every visit. MRI was performed every 3 months. Primary composite endpoint was RECIST 1.1 overall response rate (ORR) and/or clinical response (improvement ≥ 2 points in BPI-SF). If 40% of patients achieved clinical/radiological response, further investigation would be warranted. Toxicity, progression-free survival (PFS), pattern of response and its correlation with clinical best response and BPI, variation of physical function, and analgesic consumption were secondary endpoints. The translational research reported was not a pre-specified secondary outcome. Forty eligible patients started therapy, being 35 radiologically and clinically evaluable. The study achieved its primary endpoint, as 7(20%) patients obtained RECIST partial response, whereas 31(89%) experienced pain reduction of ≥2 points in BPI-SF worst pain. Therapy was well tolerated. With a median follow-up of 30(14-44) months, median 12 and 24-months PFS rates were 91%(CI 95%, 82-100) and 84%(CI 95%, 71-97). For clinical progression, 12 and 24-months PFS rates were 85% (CI 95%, 73-97) and 74% (CI 95%, 58-90) respectively. Short course of nab-paclitaxel is active, safe and achieves quick and durable responses in progressing/symptomatic DF patients.

Outcome of acute renal injury in diabetic mice with experimental endotoxemia: role of hypoxia-inducible factor-1 α

The role of diabetic nephropathy in the outcome of acute renal injury (AKI) is not well defined. Herein we evaluate the outcome of lipopolysaccharide- (LPS-) induced AKI in streptozotocin-induced diabetes, as well as the potential role of Hypoxia Inducible Factor (HIF-1 α ) in this condition. Although 6 h after LPS injection all mice developed a decrease in renal function, proteinuric diabetic mice showed a better recovery of this parameter throughout the study (72 h). Both HIF-1 α and vascular endothelium growth factor (VEGF) were found to be upregulated in diabetic mice. After LPS injection, all animals showed an upregulation of these factors, although it was higher in the diabetic group. Glycated albumin (GA) was found to upregulate HIF-1 α in HK-2 cells, which resulted in increased production of VEGF. Interestingly, LPS cooperated with GA to induce HIF-1 α upregulation. In conclusion, diabetic mice display a better recovery of AKI after experimental endotoxemia. Moreover, these animals showed an increased expression of both HIF-1 α and VEGF that was reproduced by incubating renal cells with GA. Since VEGF is considered a survival factor for tubular cells, our findings suggest that diabetes displays HIF-1 α upregulation that might function as a "precondition state" offering protection from endotoxic AKI.

Effectiveness of a diagnostic algorithm combining clinical probability, D-dimer testing, and computed tomography in patients with suspected pulmonary embolism in an emergency department

OBJECTIVE

The aim of our study was to assess the clinical effectiveness of a simplified algorithm using the Wells clinical decision rule, D-dimer testing, and computed tomography (CT) in patients with suspected pulmonary embolism (PE) in an Emergency Department (ED).

METHODS

Patients with clinically suspected PE from the Emergency Department were included from May 2007 through December 2008. Clinical probability was assessed using the Wells clinical decision rule and a VIDAS D-dimer assay was used to measure D-dimer concentration. Patients were categorized as "pulmonary embolism unlikely" or "pulmonary embolism likely" using the dichotomized version of the Wells clinical decision rule. Pulmonary embolism was considered excluded in patients with unlikely probability and normal D-dimer test (< 500 ng/ml). All other patients underwent CT, and pulmonary embolism was considered present or excluded based on the results. Anticoagulants were withheld from patients classified as excluded, and all patients were followed up for 3 months.

RESULTS

241 patients were included in the study. The prevalence of PE in the entire population was 23.6%. The combination of unlikely probability using the dichotomized Wells clinical decision rule and a normal D-dimer level occurred in 23.6%, thus making CT unnecessary. During the followup period, no thromboembolic events were recorded and there were no deaths related to venous thromboembolic disease (3-month thromboembolic risk 0% [95% CI, 0%-8%]).

CONCLUSIONS

In this study we have confirmed the effectiveness of a diagnostic management strategy using a simple clinical decision rule, D-dimer testing, and CT in the evaluation and management of patients with clinically suspected pulmonary embolism.

Diagnostic Efficacy and Prognostic Value of Serum Procalcitonin Concentration in Patients With Suspected Sepsis

Background: Procalcitonin is released in response to bacterial infection and it is not released in Inflammatory and viral diseases.

Objective: To show the diagnostic efficacy and prognostic value of procalcitonin for sepsis.

Methods: A consecutive series of 103 patients with suspected sepsis were admitted to the intensive care unit over a 2-year period. During the first 24 hours of the admission procalcitonin, C-reactive protein, and complement proteins were determined. The diagnostic efficacy was tested with predictive values, likelihood ratios, receiver operating characteristic curves, and multiple logistic regression. The association of procalcitonin with mortality was assessed by the Multivariate Cox proportional hazards model.

Results: Procalcitonin had a better positive likelihood ratio than C-reactive protein —2.2 (95% confidence interval: 1.3-3.7) versus 1.1 (95% confidence interval: 0.9-1.2). Sequential Organ Failure Assessment yielded the highest discriminative value, with an area under the curve of 0.82 (95% confidence interval: 0.73-0.92), followed by procalcitonin (0.81; 95% confidence interval: 0.72-0.89). Multivariate regression analysis showed procalcitonin (adjusted odds ratio: 3.8; 95% confidence interval: 1.2-11.8) and Sequential Organ Failure Assessment score (adjusted odds ratio: 5.3; 95% confidence interval: 1.4-19.9) as the only variables independently associated with infection. Multivariate Cox regression analysis revealed that procalcitonin was not independently associated with mortality.

Conclusions: The diagnostic accuracy of procalcitonin was higher than C-reactive protein and complement proteins. Procalcitonin in combination with Sequential Organ Failure Assessment was useful to diagnose infection. C-reactive protein, Sequential Organ Failure Assessment score, age, and gender showed to be helpful to improve the prediction of mortality risk, but not procalcitonin.

Phosphocalcic Metabolism after Biliopancreatic Diversion

BACKGROUND

Malabsorptive techniques to treat morbid obesity have been followed by alterations in phosphocalcic metabolism. Knowledge of the preoperative situation is important to assess the influence of these techniques on phosphocalcic metabolism and to consider treatments for these alterations.

METHODS

61 consecutive morbidly obese patients (50 women, 11 men, age 19 to 63 years) having had biliopancreatic diversion (BPD) were studied in a prospective manner. Preoperative and postoperative levels of calcium, phosphorus, 25-hydroxyvitamin D, tartrate resistant acid phosphate, plasma parathormone (PTH), tubular absorption of phosphate, and urinary calcium and pyridinolines were analyzed, as well as the potential risk factors for their alterations. Follow-up of all patients was a minimum of 4 years.

RESULTS

Before BPD, 42.3% of patients presented an increase in PTH and 54% a decrease in the 25-OH vitamin D, but the values of calcium and plasma phosphorus maintained at normal level. 81.8% of the patients with an increase in the PTH maintained high levels after BPD, while 60% of those with a normal preoperative PTH also presented hyperparathyroidism 4 years after the intervention. A correlation between the levels of plasma PTH and body mass index was not found.

CONCLUSION

Morbid obesity is accompanied by a high percentage of hyperparathyroidism. BPD produces malabsorption of vitamin D during the first years, favoring the persistence or appearance of hyperparathyroidism. It is important to recognize and treat the secondary hyperparathyroidism. The postoperative period could necessitate more energetic interventions to get more efficient control of the phosphocalcic metabolism.

[Differences in the synthesis pattern of vasoactive factors in gestational hypertension and preeclampsia]

BACKGROUND AND OBJECTIVE

The gestational hypertension -HG- and preeclampsia -P- are hypertensive diseases whose pathogenic mechanism has not been determined yet. The aim of this work is to define some patterns of vasoactive factors release that allow to explain the origin of the differences between both entities.

DESIGN

Prospective case-control study.

MATERIAL AND METHODS

Two groups of target patients were consecutively selected, GH (n=21) and P patients (n=21). Every patient was matched with a pregnant of similar age and week of pregnancy. Two control groups were obtained, one respect to the GH and another one respect to the P group. A biochemistry, blood cell count, coagulation and quantification of vasoactive factors endothelin, nitrites and GMPc were performed in every woman. Results of GH and P groups were compared with their respective control group with the paired Student's t Test.

RESULTS

Both systolic and diastolic arterial pressures were higher in hypertensive pregnants (GH and P) than in their respective controls. Moreover, blood endothelin and GMPc were higher in GH and P. GH pregnants showed decreased norepinephrine and increased epinephrine urinary excretion , as well as an increased plasma nitrites concentration than control group. P patients did not show statistically significant differences in catecholamines urinary excretion nor in plasma nitrites concentration respect their control group.

CONCLUSION

There are relevant differences in the synthesis patterns of vasoactive factors between gestational hypertension and preeclampsia. These differences could account for a decreased tissue perfusion in preeclampsia and could also contribute to the genesis of the renal dysfunction of this entity.

The parathyroid hormone-related protein system and diabetic nephropathy outcome in streptozotocin-induced diabetes

The pathophysiology of the diabetic kidney (e.g., hypertrophy, increase urinary albumin excretion (UAE) is still ill-defined. Parathyroid hormone-related protein (PTHrP) is overexpressed in several nephropathies, but its role remains unclear. We evaluated the effect of high glucose on PTHrP and the PTH1 receptor (PTH1R) protein (by Western blot and immunohistochemistry) in the kidney of mice ith streptozotocin-induced diabetes, and in several mouse renal cells in vitro. Diabetic mice showed a significantly increased renal expression of PTHrP and PTH1R proteins with 2-8 weeks from the onset of diabetes. These animals exhibited an intense immunostaining for both proteins in the renal tubules and glomeruli. Using transgenic mice overexpressing PTHrP targeted to the renal proximal tubule, we found a significant increase in the renal hypertrophy index and in UAE in these diabetic mice relative to their control littermates. Moreover, logistic regression analysis showed a significant association between both PTHrP and PTH1R protein levels and UAE in all diabetic mice throughout the study. High-glucose (25 mm) medium was found to increase PTHrP and PTH1R in tubuloepithelial cells, mesangial cells and podocytes in vitro. Moreover, this increase in PTHrP (but not that of PTH1R) was inhibited by the AT1 receptor antagonist losartan. Collectively, these results indicate that the renal PTHrP/PTH1R system is upregulated in streptozotozin-induced diabetes in mice, and appears to adversely affect the outcome of diabetic renal disease. Our findings also suggest that angiotensin II might have a role in the PTHrP upregulation in this condition.

Retinoids as a potential treatment for experimental puromycin-induced nephrosis

1 Puromycin aminonucleoside (PAN)-induced nephrosis is a model of human minimal change disease. In rats, PAN induces nephrotic-range proteinuria, renal epithelial cell (podocyte) damage, infiltration of mononuclear leukocytes, and apoptosis of several renal cell types. 2 Retinoic acid (RA) modulates a wide range of biological processes, such as inflammation and apoptosis. Since renal damage by PAN is characterized by inflammatory infiltration and epithelial cell death, the effect of treatment with all-trans RA (tRA) was examined in the PAN nephrosis model and in the cultured differentiated podocyte. 3 Treatment with tRA 4 days after PAN injection did not inhibit the proteinuria peak but reversed it significantly. However, treatment with tRA both before and 2 days after the injection of PAN protected the glomerular epithelial cells, diminishing the cellular edema and diffuseness of the foot process effacement. Preservation of the podocyte architecture correlated with the inhibition of proteinuria. The anti-inflammatory effect of tRA was evidenced by the inhibition of PAN-induced interstitial mononuclear cell infiltration and the decreased renal expression of two molecules involved in monocyte infiltration: fibronectin and monocyte chemoattractant protein-1. TUNEL assays showed that tRA inhibited the PAN-induced apoptosis of cultured differentiated mouse podocytes. 4 We conclude that tRA treatment may prevent proteinuria by protecting the podocytes from injury and diminishing the interstitial mononuclear infiltrate in the model of PAN nephrosis. Retinoids are a potential new treatment for kidney diseases characterized by proteinuria and mononuclear cell infiltration.

Bone mass, bone metabolism, gonadal status and body mass index

Weight and gonadal status are the main determinants of bone mass in women. Because of this it is important to study which influences it more. The effect of weight (expressed as body mass index, BMI) and gonadal status of women on total-body bone mineral content (TBBMC) and regional bone mineral content (BMC) was investigated. A total of 373 normal women (mean age 48.9 +/- 13.4 years) were studied: 171 postmenopausal women (mean age 59.3 +/- 9.5 years; years since menopause 11.3 +/- 6.7 years); 76 perimenopausal women (mean age 48.9 +/- 2.2 years); and 126 premenopausal women (mean age 34.7 +/- 7.4 years). In all the women, TBBMC and regional BMC were determined by dual-energy X-ray absorptiometry. Also biochemical markers of bone metabolism (total alkaline phosphatase and tartrate-resistant acid phosphatase) and serum estrone and estradiol were determined. When the women were stratified by gonadal status and BMI, thin women (BMI <20 kg/m2) had significantly lower TBBMC and regional BMC, lower gonadal steroid concentration and higher levels of biochemical markers than overweight (BMI 25-30 kg/m2) and obese (BMI >30 kg/m2) women, regardless of gonadal status. Overweight and obese women had findings suggestive of increased parathyroid activity, but greater bone mass. Weight rather than gonadal steroid concentration is the main determinant of bone mass in women regardless of gonadal status.

Can a determination of tartrate-resistant acid phosphatase predict postmenopausal loss of bone mass?

BACKGROUND

A study was carried out over a 24-month interval to determine if an initial measurement of serum tartrate-resistant acid phosphatase would be predictive of bone mass loss quantified by dual-energy X-ray absorptiometry, as total bone mineral content and total bone mineral content corrected for weight.

DESIGN

Sixty-two women were studied (at onset: mean age 59.7 +/- 8.9 years, 10.8 +/- 8.8 years since menopause; at conclusion: mean age 61.9 +/- 8.8 and 13.0 +/- 8.7 since menopause).

RESULTS

A paired Wilcoxon test showed a small, but significant, increase in weight (P < 0.05) and decrease in height (P < 0.05). Total bone mineral content and total bone mineral content corrected for weight decreased (P < 0.005 and 0.0001, respectively). Serum tartrate-resistant acid phosphatase increased (P < 0.005). Single-regression analysis showed that the per cent bone mass loss observed between the first and second body bone mineral content measurements correlated negatively with the first serum tartrate-resistant acid phosphatase determination (r = -0.62, P < 0.0001). Changes in tartrate-resistant acid phosphatase correlated negatively with changes in total bone mineral content (r = -0.79, P < 0.0001). In a multiple regression analysis of per cent change in bone mass against initially important variables such as age, years since menopause, weight, and tartrate-resistant acid phosphatase, only tartrate-resistant acid phosphatase was significant (P < 0.0001). The sensitivity and specifity of tartrate-resistant acid phosphatase for evaluating bone loss were 86% and 78%, respectively, and the area under the curve was of 0.83 (95% CI 0.71-0.95).

CONCLUSION

These results show that a simple measurement of serum tartrate-resistant acid phosphatase can help to predict the potential rate of bone mass loss in women.

Prognostic value of carcinoembryonic antigen, CA 19-9 and CA 72-4 in gastric carcinoma

The prognostic value of preoperative serum levels of carcinoembryonic antigen (CEA), CA 19-9 and CA 72-4 tumor markers was investigated in patients with gastric cancer. Eighty-two patients who underwent surgical resection of gastric cancer were entered in the study. Correlation analyses showed that CA 72-4 was more frequently positive in patients with advanced tumors (p = 0.04), lymph node invasion (p = 0.02), liver metastasis (p = 0.02) and peritoneal involvement (p = 0.03). CA 19-9 was more frequently positive in patients with advanced tumors (p = 0.01) and with serosal (p = 0.04), lymph node (p = 0.008) and peritoneal involvement (p = 0.02). CEA was more frequently positive in patients with liver metastasis (p = 0.03). Low 3-year cumulative survival was significantly associated with elevated serum levels of CA 72-4 (p = 0.004), CA 19-9 (p = 0.001) and CEA (p < 0.001). Age, tumor stage and CA 72-4 provided prognostic information in the multivariate analysis. Patients with elevated serum levels of CA 72-4 showed a 4.2 times higher risk of death than patients with low levels of the marker. Our results suggest that CA 72-4 has prognostic value in gastric cancer, and patients with a high preoperative serum level of CA 72-4 have a greater risk of death due to gastric cancer.

Spiral CT findings in active and remission phases in patients with Crohn disease

PURPOSE

The purpose of this study was to evaluate the radiologic findings in helical CT (HCT) that can be useful to differentiate patients with active Crohn disease (CD) from those in the remission phase.

METHOD

Fifty patients diagnosed with cases of CD were classified into active or remission phases (n = 37 and n = 13, respectively) according to clinical criteria and laboratory data. All of them underwent an abdominal HCT exploration. The following radiologic findings were evaluated: thickness, density and enhancement of the bowel wall, presence of "target" or "double halo," mesenteric involvement, and possible complications.

RESULTS

All patients in the active phase had pathologic findings on HCT. The wall thickness was 8.5 (SD 3.2) and 6.5 mm (SD 4 mm) in active and remission phases, respectively (p = 0.06). Target was present in seven patients (19%) with active disease and in five patients (38.5%) in the remission phase (p = 0.15). Density of the wall in the active phase was 95 HU and in the remission phase 65 HU (p < 0.002). Mesentery was involved in 89.2% of patients in the active phase and 38% of patients in the remission phase (p < 0.001). The complications observed in patients with active-phase disease were abscesses in nine (24%), phlegmons in two, fistulas in three, intestinal obstruction in two, and pancreatitis in one.

CONCLUSION

A normal HCT rules out that a patient with CD is in the active phase of disease. The presence of significant bowel wall enhancement and mesentery involvement assists in the differentiation of patients in the active phase from those in remission. HCT is also effective to assess the presence of complications, which are indicative of the active phase.

Behavior of phalangeal bone ultrasound in normal women with relation to gonadal status and body mass index

The behavior of phalangeal bone ultrasound was studied, measured by amplitude-dependent speed of sound (Ad-SOS) in meters per second, in 324 normal women (mean age 48.9 +/- 13.7 years) classified by gonadal status (premenopausal, perimenopausal and postmenopausal) and body mass index (BMI, thin, normal, overweight and obese). Ad-SOS differed significantly with gonadal status and BMI (p<0.0001 for all). In the overall group of women, Ad-SOS correlated negatively with age (r=-0.84, p<0.0001), weight (r=-0.16, p<0.005), BMI (r=-0.27, p<0.0001), and tartrate-resistant acid phosphatase concentration (TRAP) (r=-0.35, p<0.0001). The negative correlation remained significant in the groups separated by gonadal status, but to a lesser extent. After adjusting for confounding variables such as age and weight, Ad-SOS was dependent on age (but not on weight or BMI) in the overall group of women and in the gonadal status groups. In conclusion, Ad-SOS values differed significantly with gonadal status and BMI, and correlated negatively with TRAP. The plot of Ad-SOS against age differed significantly with gonadal status as well as BMI.

[Usefulness of the percentage of free prostatic specific antigen in the differential diagnosis between benign prostatic hyperplasia and prostate cancer]

BACKGROUND

PSA (prostatic specific antigen) is the most used tumor marker to monitor prostate cancer (PC). It is an acceptably sensitive test. Molecular forms of PSA give a chance to improve its specificity. We have evaluated the usefulness of the ratio free PSA/total PSA (f-PSA/t-PSA%) to diagnose prostate cancer, in the range between 4 and 20 ng/ml; i.e. the interval in which values overlap for patients with PC and benign prostatic hyperplasia (BPH) in our environment.

PATIENTS AND METHODS

Prospective study on 269 patients, 73 with PC and 196 with BPH. Both t-PSA and f-PSA were determined using microparticles enzyme immune assay (MEIA) with AXSYM (Abbott) analyzer.

RESULTS

Statistically significant differences were evidenced in f-PSA/t-PSA% for patients with PC vs. BPH; but that did not happen for t-PSA values. Sensitivity and specificity values were established for different cut-off points. ROC curve analysis proved diagnostic efficacy was better for f-PSA/t-PSA% than for t-PSA.

CONCLUSIONS

f-PSA/t-PSA percentage is a useful tool for the differential diagnosis between PC and BPH. A ratio lower than 12% selects a population with high risk of cancer. A percentage over 18% is useful to avoid or delay the indication of biopsy.

Changes in body composition in women treated with gonadotropin-releasing hormone agonists

OBJECTIVE

The changes that agonists of gonadotropin-releasing hormone (GnRH) produce in mineral bone mass are known, but, as far as we know, those produced by these agents in other body compartments are unknown.

METHODS

We studied these changes using dual-energy X-ray absorptiometry in 50 eugonadal women treated with decapeptyl (Triptoreline), 3.75 mg injected intramuscularly, at 28-day intervals for 6 months.

RESULTS

There were significant increases in fat content (9.5%, P < 0.0005) and weight (1.3%, P < 0.01), and significant decreases in fat-free mass (-1.9%, P < 0.0001) and water content (-1.8%, P < 0.0002). Bone mass was lost in the axial skeleton (-3.6%, P < 0.0001) but not in the peripheral skeleton.

CONCLUSIONS

The changes induced in body composition by the GnRH agonists are similar to those of natural menopause.

Cyclosporine increases local glomerular synthesis of reactive oxygen species in rats: effect of vitamin E on cyclosporine nephrotoxicity

BACKGROUND

We report an investigation of the effects of cyclosporine (CsA) on kidney function, the glomerular synthesis of reactive oxygen species, the peroxidation of lipids, and the levels of thromboxane B2 (TXB2). The effect of the simultaneous administration of the antioxidant vitamin E (Vit E) and CsA in rats was also evaluated.

METHODS

Adult male Wistar rats were treated for 30 days with CsA (30 mg/kg/day), with Vit E (0.05 mg/ml), with CsA plus Vit E, or with the vehicle used for administration of CsA, namely 12.6% ethanol.

RESULTS

CsA induced kidney failure and increased the glomerular synthesis of superoxide anion, H2O2, malonyldialdehyde, and TXB2. Vit E minimized the adverse effects of CsA on kidney function and the glomerular synthesis of these compounds.

CONCLUSIONS

Our results suggest that the acute decrease in glomerular filtration rate induced by CsA might be mediated by the synthesis of reactive oxygen species and subsequent peroxidation of lipids, which increases the levels of TXB2. Treatment with Vit E prevented these effects, suggesting a possible role for antioxidants in the prevention of CsA nephrotoxicity.

Total and regional bone mass and biochemical markers of bone remodeling in metastatic prostate cancer

BACKGROUND

The osteolytic activity of metastases of prostate cancer was evaluated in relation to total body bone mineral content (TBBMC) and regional bone mineral content (RBMC).

METHODS

Bone mass was determined by dual-energy X-ray absorptiometry (DXA). Tartrate-resistant acid phosphatase (TRAP) was measured as a biochemical marker of bone resorption.

RESULTS

In 32 patients (mean age 72+/-4 years) compared with 32 controls (mean age 73+/-5 years), there were significant differences in TRAP (P < 0.0001), TBBMC (P < 0.0001), and RBMC in the pelvis (P < 0.0001), legs (P=0.0001), and trunk (P<0.05), but not in the arms and head (P=ns). In the overall group of subjects, the correlation between TBBMC and TRAP was r=-0.68, P < 0.0001. The correlations remained significant in the patient and control groups separately.

CONCLUSIONS

The loss of bone mass observed in patients with metastatic prostate cancer was caused mainly by the predominance of bone resorption in the osteoblastic metastases.

Cyclosporin A-induced hydrogen peroxide synthesis by cultured human mesangial cells is blocked by exogenous antioxidants

Cyclosporin A (CsA) is the immunosupressor most widely used in transplanted patients for preventing organ rejection, but it has some toxic side effects in vascular beds and kidney. The purpose of this work was to study if H2O2, a reactive oxygen species, is involved in the CsA-induced toxic effects on kidney in vitro. Human mesangial cells (HMC) in culture were incubated in presence of CsA (10[-5]-10[-8]M) and H2O2 was measured by flow cytometry. The specificity of the probe used in this method was demonstrated as fluorescence was not detected when superoxide anion generated through a Xanthine-Xanthine oxidase system was present, but fluorescence was noted when H2O2 was present in the incubation medium, both directly and after addition of superoxide dismutase to the medium thus promoting H2O2 synthesis. CsA induced a significant dose and time-response increased H2O2 synthesis by cultured HMC. This increase appeared 5 min after CsA addition, being maximal between 15-45 min at CsA concentration of 10(-7)M. When HMC were preincubated with antioxidants as vitamin E or selenium, the CsA-induced H2O2 production was partially blocked. In addition, selenium also induced an increased activity of glutathion peroxidase in HMC after 24 hours of incubation, suggesting that it exerted its H2O2 scavenging action through the modulation of the activity of this enzyme.

Cyclosporine A nephrotoxicity: role of thromboxane and reactive oxygen species

The main adverse effect of cyclosporine A (CyA) is nephrotoxicity. CyA increases urinary concentrations of thromboxane A2 (TXA2), a potent vasoconstrictor that can be involved in kidney failure induced by CyA. Furthermore, it has been postulated that a relationship exists between oxygen free radicals and the synthesis of arachidonate metabolites in experimental models of CyA nephrotoxicity. We studied the effect of vitamin E (VitE), an oxygen free radical scavenger, on renal function, on glomerular synthesis of thromboxane B2 (TXB2), and on free radicals in rats treated with CyA. Four groups of male Wistar rats were studied: (1) a control group; (2) a group given VitE at 0.05 mg/dl in drinking water for 25 days; (3) a group given CyA at 50 mg/kg body weight/day orally for 10 days; and (3) a group given Vit E + CyA, in which rats were provided with drinking water containing VitE for 15 days and afterwards were treated with VitE and CyA for 10 days. Renal function parameters and glomerular synthesis of TXB2, superoxide anion (02.-), malondialdehyde (MDA), and hydrogen peroxide (H202) were evaluated. CyA decreased body weight, caused deterioration of kidney function and increased glomerular synthesis of TXB2, O2.-, MDA, and H202. Pretreatment with VitE prevented the effects of CyA on kidney function and decreased glomerular synthesis of these mediators. In conclusion, CyA induced glomerular synthesis of reactive oxygen species (ROS) and TxB2. Pretreatment with VitE inhibited acute renal failure induced by CyA, probably by scavenging free radicals and by inhibiting the synthesis of TXB2.

New evidence that serum beta(2)-microglobulin behaves as a biological marker of bone remodelling in women

Having observed that serum beta(2)-microglobulin concentration correlates with serum tartrate-resistant acid phosphatase (TRAP) concentration in postmenopausal osteoporosis, and that metacarpal endosteal diameter is dependent on bone resorption, we correlated the two biochemical parameters with the radiographic parameter to determine if beta(2)-microglobulin behaves like a biological marker of bone remodelling. In 105 women (mean age 68 +/- 4 years) consisting of 60 normal postmenopausal women and 55 osteoporotic postmenopausal women, there was a significant positive correlation between metacarpal endosteal diameter and these two biochemical values (r = 0.66 with beta(2)-microglobulin and r = 0.68 with TRAP in the osteoporotic postmenopausal women; r = 0.48 with beta(2)-microglobulin and r = 0.56 with TRAP in the normal postmenopausal women; P < 0.001 for all comparisons). All three measurements were significantly higher (P < 0.001) in the osteoporotic postmenopausal women than in the normal postmenopausal women. These findings show that serum beta(2)-microglobulin behaves like a biological marker of remodelling.

Beta-2-microglobulin in diseases with high bone remodeling

Beta2-microglobulin has been observed to behave as a biological marker of bone remodeling. We measured beta2-microglobulin and tartrate-resistant acid phosphatase (TRAP), a specific biological marker of bone remodeling, in 225 women: healthy premenopausal controls, healthy postmenopausal control, and patients with diseases characterized by enhanced bone turnover (postmenopausal osteoporosis, primary hyperparathyroidism, primary hyperthyroidism, polyostotic Paget's bone disease), and in other Paget's group before and after calcitonin treatment. Beta2-microglobulin levels differed significantly between the healthy premenopausal women (n = 20) compared with all the other groups. However, beta2-microglobulin levels did not differ significantly between healthy postmenopausal women (n = 38) and patient's with Paget's bone disease (n = 40)(P = 0.5095), or between women with postmenopausal osteoporosis (n = 30) and women with hyperthyroidism (n = 20)(P = 0.7890). TRAP concentrations differed significantly in all the groups paired except for women with Paget's bone disease and women with either hyperparathyroidism or hyperthyroidism (P = 0.5179 and 0.6993, respectively); likewise, TRAP levels did not differ significantly between the women with hyperparathyroidism and those with hypothyroidism (P = 0.7804). After calcitonin treatment, there was a 22% increase in beta2-microglobulin, a 17% decrease in TRAP, and a 39% decrease in alkaline phosphatase, all of which were significant at P < 0.0001. Our findings indicate that serum beta2-microglobulin, like osteocalcin, behaves as a biological marker of remodeling in a number of diseases with enhanced bone remodeling but not in Paget's bone disease.

Zinc, biochemical markers of nutrition, and type I osteoporosis

Having observed previously that the reduction of levels of biological markers of nutrition in postmenopausal osteoporosis may be related to zinc deficiency, we measured plasma and urinary zinc concentrations in 30 women with postmenopausal osteoporosis and in 30 healthy postmenopausal women who served as controls. Plasma zinc levels did not differ between groups, but urinary zinc excretion was significantly higher in the women with postmenopausal osteoporosis (p = 0.002). The relation between total body bone mineral content corrected for body weight (TBBMC/W) and markers of nutrition was significant (multiple regression analysis: p < 0.0001) in the women with postmenopausal osteoporosis but not in the healthy postmenopausal controls. Likewise, the relation between TBBMC/W and plasma and urinary zinc levels also was significant in the women with postmenopausal osteoporosis but not in the controls (multiple regression analysis: p = 0.0022). Neither group showed any correlation between plasma or urinary zinc concentrations and levels of biological markers of nutrition. Urinary zinc concentration correlated significantly with serum tartrate-resistant acid phosphatase level (simple linear regression analysis: r = 0.583, p < 0.001) in the women with postmenopausal osteoporosis but not in controls. TBBMC correlated with urinary zinc concentration significantly in the women with postmenopausal osteoporosis (simple linear regression: r = 0.567, p = 0.0015), but the correlation was nonsignificant in healthy postmenopausal controls. These findings indicate that the elevation of urinary zinc elimination in osteoporosis is dependent on bone resorption.

Thromboxane A2 and platelet-activating factor decrease in the platelet-mesangial cell interactions

To analyze the metabolisms of platelet-activating factor (PAF) and Thromboxane A2 (TxA2) when platelets and mesangial cells (MC) interact, immunoreactive thromboxane B2 (TxB2) and PAF were measured after incubation of cultured rat MC with platelets (P) and with platelet supernatants (PS). In both cases, TxB2 significantly decreased with respect to the P synthesis and to the PS content, suggesting an increased degradation of this metabolite or even the existence of a specific effect of MC upon platelet TxB2. When immunoreactive PAF was measured, results were comparable to those observed for TxB2. Moreover, when intrinsic mesangial cell synthesis of PAF was assessed by analyzing the [3H]-acetate incorporation by prelabeled MC in the HPLC fraction coeluting with cold PAF standards, it was possible to demonstrate that P or PS did not modify PAF synthesis in these cells. In summary, present results support the existence of a specific effect of mesangial cells upon platelet TxA2 and PAF.

Biochemical markers of nutrition in type-I and type-II osteoporosis

We studied nutritional deficits, using as markers the levels of transferrin, retinol-binding protein, and prealbumin, in 20 women with osteoporotic hip fractures (type II), 40 women with vertebral fractures (type I), and two groups of age-matched control subjects. The concentrations of all three nutritional markers were lower in the two groups of patients than in their matched controls, and in type-I as compared with type-II osteoporosis. In the osteoporotic patients, simple linear regression showed a significant correlation between the variables which we studied (r2 ranged from 0.5 to 0.7; p < 0.001), the best correlation being between prealbumin and retinol-binding protein in type-II osteoporosis. Our results suggest that there is a more marked nutritional deficit in type-II than in type-I osteoporosis.

Biochemical markers of nutrition in type-I and type-II osteoporosis

We studied nutritional deficits, using as markers the levels of transferrin, retinol-binding protein, and prealbumin, in 20 women with osteoporotic hip fractures (type II), 40 women with vertebral fractures (type I), and two groups of age-matched control subjects. The concentrations of all three nutritional markers were lower in the two groups of patients than in their matched controls, and in type-I as compared with type-II osteoporosis. In the osteoporotic patients, simple linear regression showed a significant correlation between the variables which we studied (r2 ranged from 0.5 to 0.7; p < 0.001), the best correlation being between prealbumin and retinol-binding protein in type-II osteoporosis. Our results suggest that there is a more marked nutritional deficit in type-II than in type-I osteoporosis.

Longitudinal study of the effect of calcium pidolate on bone mass in eugonadal women

Seventy-two eugonadal women, mean age 39 +/- 4 years, with a z score for total body bone mineral content (BMC) of less than -1.5 (mean -1.80 +/- 0.12) were selected from a previous screening study of normal values of total body and regional BMC in women using dual-energy X-ray absorptiometry. The women were distributed into two groups: 36 women undergoing treatment with 1 g/day of elemental calcium in the form of calcium pidolate and 36 women not treated. One year later, total body BMC, regional BMC in arms, legs and trunk, 24-hour urinary calcium excretion (Ca 24 hour), fasting urinary calcium/creatinine ratio, and serum tartrate-resistant acid phosphatase concentration were measured in both groups. There was a significant increase in total body and regional BMC (P < 0.001) in the group taking calcium pidolate. The increase was greater in arms and legs (2.5%) than in trunk (1.7%), being 2.6% for total body BMC. The z score increased from -1.81 +/- 0.13 to -1.52 +/- 0.12 (16%, P < 0.001). The corporal index did not change, and total body BMC corrected for fat-free body mass increased by 6.7% (P < 0.001). These changes were accompanied by an increase in 24-hour urinary calcium excretion and a decrease in urinary calcium/creatinine ratio and serum tartrate-resistant acid phosphatase concentration (P < 0.05 for all). There was a correlation between cumulative calcium dose at the end of treatment and gain in total body BMC (r2 = 0.925, P < 0.001). The untreated group showed no changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of weight and seasonal changes on radiogrammetry and bone densitometry

We studied the behavior of radiogrammetric and densitometric measurements in relation to season and body weight in a group of 30 healthy premenopausal women. Measurements were made at 6-month intervals, in summer/fall when bone density increases and in winter/spring when bone density declines. Total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) were measured using dual-energy X-ray absorptiometry (DXA). Metacarpal radiogrammetry was carried out with computed radiography. Weight and body mass index increased significantly in winter (P < 0.05) and total body and RBMC decreased (P < 0.001). The opposite occurred in summer: weight and body mass index decreased significantly (P < 0.05) and total body and regional bone mineral content increased (P < 0.001). Differences in TBBMC persisted when the measurement was corrected for weight (TBBMC/W) (P < 0.001), but not for metacarpal cortical thickness corrected for weight. In the first measurement made there were significant relations between weight and both TBBMC (P < 0.001) and metacarpal cortical thickness (P < 0.005). The relation between weight and TBBMC remained significant in later measurements, but the relation between weight and metacarpal cortical thickness ceased to be significant in the second and fourth measurements. Our results show that there is an important seasonal variation in bone mass and that DXA is more sensitive than radiogrammetry in registering these changes.

Etidronate versus clodronate in the prevention of postovariectomy bone loss. An experimental study in rats

OBJECTIVE

We compared the diphosphonates etidronate and clodronate to find out which was more effective in inhibiting the loss of bone mass after ovariectomy in rats.

METHODS

Five lots of female Sprague Dawley rats, each containing 15 rats (14 wks old; mean weight 290 g), were kept under identical living conditions (12 hrs of light and 12 hrs of darkness), habitat, and diet following the current norms of the European Economic Community. One lot was kept as a control; one lot underwent sham ovariectomy (Sham-OVX); and the remaining 3 lots were anesthesized and underwent double ovariectomy (OVX). One lot of ovariectomized rats was given etidronate by esophageal tube, 5 mg/kg/day (OVX-E); one lot was treated with intraperitoneal clodronate, 5 mg/kg/3 days (OVX-Cl). The remaining lot was not manipulated (OVX). The animals' right femurs were then dissected for measurements of the bone mineral content.

RESULTS AND CONCLUSION

Bone densitometry revealed that loss of bone mass 2 months after ovariectomy in the OVX-Cl group was 2.3%, not differing from that of the control group; bone loss in the OVX-E group was 11.7%, significantly different from the control group and from the OVX-Cl group (p < 0.001). These results show that clodronate is superior to etidronate in inhibiting osteopenia after ovariectomy in rats.

beta 2-Microglobulin in Paget's bone disease

On the basis of earlier findings of increased serum beta 2-microglobulin concentration in women with postmenopausal osteoporosis, we decided to study serum beta 2-microglobulin concentration in other bone diseases. In 28 patients with untreated Paget's bone disease, serum beta 2-microglobulin concentration was normal (1.49 +/- 0.41 mg/liter versus 1.36 +/- 0.21 mg/liter in 42 control subjects, P = ns), a finding that contradicts reports in the literature. We found that serum beta 2-microglobulin concentration was related negatively and significantly (r2 = -0.154, P = 0.0354) with serum total alkaline phosphatase concentration, but not with serum tartrate-resistant acid phosphatase concentration (p = ns). Urinary elimination of beta 2-microglobulin was lower in the patients with Paget's disease than in the controls (34 +/- 28 versus 120 +/- 21 mg/liter, P < 0.001). These findings suggest that beta 2-microglobulin behaves similarly to osteocalcin (BGP) in Paget's bone disease and that its concentration remains within normal levels perhaps because of the rate of reuptake of beta 2-microglobulin in bone neoformation.

Changes in renal function in acute experimental pancreatitis in rats: a therapeutic role for somatostatin

1. The present study was designed to determine the changes in renal function in two models of experimental pancreatitis in rats, in an attempt to assess the possible pathogenic role of reactive oxygen species and to elucidate a possible therapeutic role for somatostatin. 2. Mild pancreatitis was induced by low blockade of the biliary duct and severe pancreatitis was evoked by retrograde infusion of bile salts. Renal function was studied by clearance techniques in rats with pancreatitis, treated or not treated with somatostatin. Plasma and glomerular malonyldialdehyde levels were measured by the thiobarbituric acid method. 3. Renal function did not change in rats with low blockade of the biliary duct, but animals receiving a retrograde infusion of bile salts showed a significant decrease in glomerular filtration rate and renal plasma flow with respect to sham-operated animals. 4. Plasma malonyldialdehyde levels increased significantly in rats treated with bile salts with respect to control animals, whereas no changes were detected in glomerular malonyldialdehyde levels. Thus, the renal dysfunction does not seem to be related to an increased production of reactive oxygen metabolites at the glomerular level. 5. Somatostatin infusion significantly improved renal function in rats with severe pancreatitis (retrograde infusion of bile salts) by increasing glomerular filtration rate, renal plasma flow and filtration fraction. These results support a possible therapeutic role for somatostatin in the renal dysfunction associated with the severe forms of pancreatitis.

Direct interactions between platelets and cultured rat mesangial cells

Platelets seem to be involved in the pathogenesis of some kidney diseases, but the exact relationships between platelets and the changes in renal function are incompletely known. Mesangial cells (MC) were incubated with platelet-supernatants (PS) and cellular surface area (CSA) and myosin light-chain phosphorylation (MLCP) were measured. CSA of PS-incubated MC (PS-MC) significantly diminished, as compared to control MC (70 +/- 6% vs. 100 +/- 5%). PS induced a significant increase in MLCP with respect to control cells (150 +/- 23% vs. 100 +/- 18%). When platelets were pretreated with indomethacin, the PS-dependent contraction was abolished. Pretreatment with sulotroban (SU) or BN-52021 (BN), a thromboxane A2 (TXA2) and a platelet-activating factor (PAF) receptor blocker respectively, also completely blocked the PS effects. In other experiments, platelets were activated with thrombin (T), adding the so obtained PS to MC. Moreover, cells were also preincubated with T and then added PS. No changes in CSA were observed in either case. It may be concluded that PS contracted cultured MC, and these changes could be related to the decreased glomerular filtration rate (GFR) observed in some diseases in which platelets seem to be involved. TXA2 and PAF may be responsible for this effect. In contrast, T incubation inhibited the effect of PS, perhaps through a direct relaxing effect of T in MC.

Total and regional bone mineral content in women treated with GnRH agonists

Changes in bone mineral content induced by GnRH agonists were investigated by measuring total body bone mineral content (TBBM) and regional bone mineral content (BMC) (arms, legs, trunk, pelvis) and densities with dual energy X-ray absorptiometry in 25 premenopausal women before and after a 6-month treatment with gonadotropin-releasing hormone (GnRH) agonists. Biological markers of bone remodeling, estrogens, luteinizing hormone, and follicle-stimulating hormone were also measured. Weight and body mass index increased significantly after treatment (P < 0.05), and TBBM, corrected for weight (TBBM/W), decreased (P < 0.001). The changes in BMC that we observed ranged from +2.5% to -6.9%. The greatest decrease in regional BMC occurred in the trunk (4.4%, P < 0.001), with TBBM decreasing by 2.1% (P < 0.001). No significant changes were observed in the limbs. Tartrate-resistant acid phosphatase (TRAP) increased significantly after treatment (P < 0.001) and a significant negative correlation between TRAP and TBBM (P < 0.001) and between TRAP and estradiol (P < 0.001) were observed before treatment. The lack of changes observed in the BMC of the limbs indicate that GnRH agonists cause a preferential loss of BMC in trunk osseous structures, a situation similar to that of the first years of menopause.

Biochemical markers of nutrition in osteoporosis

Thirty-six women with vertebral osteoporosis showed significantly decreased levels of biochemical markers of nutrition, transferrin (P < 0.001), prealbumin (P < 0.001), retinol binding-protein (P < 0.001), and fibronectin (P < 0.001), compared with 40 healthy women of similar age. Multiple regression analysis showed a significant (R2 = 0.509; P = 0.0068) correlation between bone mineral content and biochemical markers of nutrition in the osteoporotic patients but not in the control group. These data suggest that postmenopausal osteoporosis may be associated with a nutritional deficiency.

Total and regional bone mass values and biochemical markers of bone remodeling in endometriosis

OBJECTIVE

TO measure peripheral, axial, and total bone mass and to assess markers of bone remodeling in women with endometriosis, with the aim of addressing previous reports of diminished peripheral bone mass in these patients.

METHODS

Whole body bone densitometry, estradiol (E2) levels, and biochemical bone markers (calcium, phosphorus, total alkaline phosphatase, tartrate-resistant acid phosphatase, and total proteins) were determined in 28 patients with endometriosis and compared with findings in 33 controls.

RESULTS

There were no significant differences between the groups in bone mass at different sites or in biochemical bone markers. We observed a significant negative correlation between tartrate-resistant acid phosphatase and E2 levels (P < .001) and with total (P < .001), head (P < .01), and axial (trunk) (P < .001) bone mass. Total alkaline phosphatase did not correlate with any of the indices studied.

CONCLUSIONS

Bone mass was not lower in any of the areas studied in women with endometriosis. There was a significant negative correlation of tartrate-resistant acid phosphatase with E2 and with total, head, and trunk bone mass.

Effects of reactive oxygen species on cultured rat mesangial cells and isolated rat glomeruli

The effects of reactive oxygen species (ROS) on cultured rat mesangial cells were studied by measuring planar cell surface area (PCSA) after incubation with xanthine plus xanthine oxidase (XXO), in the presence of superoxide dismutase (SOD; 5 micrograms/ml) or catalase (CAT; 20 micrograms/ml), or after incubation with H2O2. Myosin light chain (MLC) phosphorylation was assessed in cells prelabeled with o-[32P]phosphoric acid and incubated with H2O2, after protein separation with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A possible intermediate role for platelet-activating factor (PAF) was analyzed by preincubation of the cells with a PAF antagonist BN 52021 (BN, 5 x 10(-5) M) and by measuring PAF-specific [3H]acetate incorporation and immunoassayable PAF. XXO significantly decreased PCSA (14%), an effect abolished by CAT but not by SOD. H2O2 induced a similar effect, in a dose-dependent and time-dependent manner. MLC phosphorylation increased by 81 +/- 15% after H2O2 incubation, and this effect was blocked by BN. BN also completely blocked the effect of H2O2 on PCSA. PAF-specific [3H]acetate incorporation increased in the presence of H2O2 (from 6,886 +/- 2,030 to 58,703 +/- 16,063 counts.min-1.mg-1) as well as the immunoassayable PAF production by cells (from 0.90 +/- 0.19 to 6.71 +/- 2.27 ng/mg). These results suggest that ROS, particularly H2O2, could modulate the surface area of mesangial cells, modifying the ultrafiltration coefficient, thus explaining the decrease in glomerular filtration rate in those pathological situations characterized by an increased ROS synthesis. PAF could be involved in the genesis of these effects.

[Biological profile of tartrate-resistant acid phosphatase as a marker of bone resorption]

Tartrate-resistant serum acid phosphatase was measured in 123 subjects, 80 of which were normal and the rest pathologic, in order to define the profile and value of this parameter as a biological marker of osteoclastic activity. Normal subjects were divided into age groups based on the period where skeletal growth ends (under 20 years), at the age of menopause in women (50 years, between 20 and 50 years) and those over 50 years. There was an increase in tartrate-resistant serum acid phosphatase coinciding with puberty and no sex differences were observed after the 50 year mark, when women showed higher values than men (p less than 0.001). Such tartrate-resistant serum acid phosphatase increase, is reflected as higher values in the 50 year group than in the 20 to 50 year group (p less than 0.001), the only age limit where a negative significant correlation between tartrate-resistant serum acid phosphatase values and age could be observed (p less than 0.05). Values were higher up to the age of 20 years (p less than 0.001) than in any other older age group. Levels increased significantly (p less than 0.001 for both groups) in post-menopausal osteoporosis (n = 20) and in Paget's disease of bone (n = 15), and decreased significantly (p less than 0.05) in imperfect osteogenesis (n = 8), thus revealing its value as a biological marker of osteoclastic activity.