Extracellular matrix educates an immunoregulatory tumor macrophage phenotype found in ovarian cancer metastasis.

Recent studies have shown that the tumor extracellular matrix (ECM) associates with immunosuppression, and that targeting the ECM can improve immune infiltration and responsiveness to immunotherapy. A question that remains unresolved is whether the ECM directly educates the immune phenotypes seen in tumors. Here, we identify a tumor-associated macrophage (TAM) population associated with poor prognosis, interruption of the cancer immunity cycle, and tumor ECM composition. To investigate whether the ECM was capable of generating this TAM phenotype, we developed a decellularized tissue model that retains the native ECM architecture and composition. Macrophages cultured on decellularized ovarian metastasis shared transcriptional profiles with the TAMs found in human tissue. ECM-educated macrophages have a tissue-remodeling and immunoregulatory phenotype, inducing altered T cell marker expression and proliferation. We conclude that the tumor ECM directly educates this macrophage population found in cancer tissues. Therefore, current and emerging cancer therapies that target the tumor ECM may be tailored to improve macrophage phenotype and their downstream regulation of immunity.

Targeting immunoliposomes to EGFR-positive glioblastoma.

BACKGROUND: We assessed the capacity of epidermal growth factor receptor (EGFR)-targeted immunoliposomes to deliver cargo to brain tumor tissue in patients with relapsed glioblastoma harboring an EGFR amplification. We aimed to assess the tolerability and effectiveness of anti-EGFR immunoliposomes loaded with doxorubicin (anti-EGFR ILs-dox) in glioblastoma multiforme patients. PATIENTS AND METHODS: Patients with EGFR-amplified, relapsed glioblastoma were included in this phase I pharmacokinetic trial. Patients received up to four cycles of anti-EGFR ILs-dox. Twenty-four hours later, plasma and cerebrospinal fluid (CSF) samples were obtained. In addition, we also treated three patients with anti-EGFR ILs-dox before resection of their relapsed glioblastoma. Doxorubicin concentrations were measured in plasma, CSF, and tumor tissue. Safety and efficacy parameters were also obtained. RESULTS: There were no or negligible levels of doxorubicin found in the CSF demonstrating that anti-EGFR ILs-dox are not able to cross the blood-brain barrier (BBB). However, significant levels were detected in glioblastoma tissue 24 h after the application, indicating that the disruption of BBB integrity present in high-grade gliomas might enable liposome delivery into tumor tissue. No new safety issues were observed. The median progression-free survival was 1.5 months and the median overall survival was 8 months. One patient undergoing surgery had a very long remission suggesting that neoadjuvant administration may have a positive effect on outcome. CONCLUSIONS: We clearly demonstrate that anti-EGFR-immunoliposomes can be targeted to EGFR-amplified glioblastoma and cargo-in this case doxorubicin-can be delivered, although these immunoliposomes do not cross the intact BBB. (The GBM-LIPO trial was registered as NCT03603379).

The complex relationship between inflammation and lung function in severe asthma.

Asthma is a common respiratory disease affecting ∼300 million people worldwide. Airway inflammation is thought to contribute to asthma pathogenesis, but the direct relationship between inflammation and airway hyperresponsiveness (AHR) remains unclear. This study investigates the role of inflammation in a steroid-insensitive, severe allergic airway disease model and in severe asthmatics stratified by inflammatory profile. First, we used the T-helper (T(H))-17 cells adoptive transfer mouse model of asthma to induce pulmonary inflammation, which was lessened by tumor necrosis factor (TNF)-α neutralization or neutrophil depletion. Although decreased airspace inflammation following TNFα neutralization and neutrophil depletion rescued lung compliance, neither intervention improved AHR to methacholine, and tissue inflammation remained elevated when compared with control. Further, sputum samples were collected and analyzed from 41 severe asthmatics. In severe asthmatics with elevated levels of sputum neutrophils, but low levels of eosinophils, increased inflammatory markers did not correlate with worsened lung function. This subset of asthmatics also had significantly higher levels of T(H)17-related cytokines in their sputum compared with severe asthmatics with other inflammatory phenotypes. Overall, this work suggests that lung compliance may be linked with cellular inflammation in the airspace, whereas T-cell-driven AHR may be associated with tissue inflammation and other pulmonary factors.

Bone turnover, osteopenia and vascular calcifications in hemodialysis patients. A histomorphometric and multislice CT study.

BACKGROUND: Several classical risk factors are at the base of vascular calcifications in hemodialysis patients. Among these, according to a general opinion, also bone turnover plays a role, which, however, requires a better definition. In addition, it has been suggested that there is a relationship between primary osteoporosis and vascular calcifications. This bone biopsy-based study on a hemodialysis patient cohort is a contribution to the evaluation of these alleged relations. METHODS: This study has been carried out on a cohort of 32 patients on maintenance hemodialysis, who were subjected to transiliac bone biopsy for histomorphometric, histodynamic and bone aluminum deposit evaluation. The patients were also examined with multislice computerized tomography for quantitation of heart and coronary calcifications. RESULTS: The patients were affected by renal osteodystrophy with a wide range of bone formation rate values. A significant negative correlation was found between the rate of bone turnover and log-transformed cardiac calcification score (p < 0.003). There were also negative significant correlations between the cardiac and coronary calcification score log and trabecular number (p < 0.02 and p < 0.05, respectively), while the correlations were positive with trabecular separation (p < 0.03 and p < 0.05, respectively). However, multiregression analysis, forward method, selected only age, hemodialysis age and serum Ca as predictive variables of cardiac and coronary calcification score log, while the histomorphometric and histodynamic variables were excluded. CONCLUSIONS: In this study, in spite of the suggestive findings of the univariate statistical approach, a further multivariate analysis was indicative of a spurious association between calcification scores and both bone turnover and histomorphometric parameters of trabecular mass and connectivity. Bone turnover and trabecular mass do not appear to be prominently connected with the extent of cardiac and coronary calcifications in hemodialysis patients.

Cardiac calcifications in hemodialysis patients assessed with spiral computed tomography.

AIM: Cardiac disease is a major cause of mortality in uremic patients. The aim of this paper was to evaluate cardiac calcium content in uremic patients with multislice computed tomography (MSCT). METHODS: The study has been carried out on 120 uremic and 28 nonuremic patients affected by cardiovascular disease. Serum calcium, phosphorus, calcium-phosphate product, intact PTH were assayed. Several lipidic and nutritional parameters were measured. Calcification values obtained with the MSCT were reported in terms of Agatson scores. RESULTS: We found that the average score values in cohort on uremic was 10 times higher than in nonuremic patients (score values 3.389 vs 328). Cardiac calcification score was found to be correlated significantly to age (P=0.006), HD age (P=0.010), serum calcium (P=0.006), iPTH (P=0.004). Multiregression analysis (MRA) with the cardiac score as dependent variable selected the following variables (R(2) 0.612): age (P=0.002), HD age (P=0.010), serum cholesterol (P<0.000), triglycerides (P=0.001) and inversely HDL cholesterol (P=0.001) and non-HDL cholesterol (P=0.001) as predictive variables for cardiac score. By comparing patients with scores lower and higher than 400, the group with score <400 showed a significantly lower age (P=0.0001), HD vintage (P=0.01) and a significantly higher serum cholesterol (P=0.009), HDL cholesterol (P=0.05) and non-HDL cholesterol (P=0.05). CONCLUSIONS: The MSCT could help in identifying and stratifying high-risk patients to implement preventive strategies. The control of mineral metabolism and of lipid levels is important in prevention of arterial calcification in uremic patients.

[Can cardiovascular calcifications be prevented in chronic kidney disease?]. / E possibile prevenire i processi di calcificazione cardiovascolare nel paziente con insufficienza renale cronica?

Chronic kidney disease, with special regard to hemodialysis patients, develop frequent and widespread cardiac and vascular calcifications. In the heart calcifications are mainly located in the coronary arteries and in the valvular structures. There is a strict relation between cardiovascular mortality in CKD and the extent of cardiac and vascular calcifications. Therefore it is important to evaluate the causes of extraskeletal calcifications for the evaluation of the possibility of prevention. The importance of hyperphosphatemia, of hypercalcemia and of the increased CAxP product as a cause of cardiac calcification has been clearly underlined. However the mechanism of calcification, initially considered a physico-chemical precipitation, has been investigated with the conclusion that the process is mediated by cellular differentiation and production of factors favoring mineralization in the extracellular milieu. Increased serum phosphate levels are able to induce a transformation of vascular smooth muscle cells into osteoblast-like cells, able to produce factors known to be pro-mineralizing agents in the bone tissue. Further studies have revealed the importance of a number of inhibitors of calcification of cardiovascular structures, like Fetuin-A, MGP, Osteopontin, Osteoprotegerin. Therefore at present the calcification process of vascular tissue is considered to be linked to a balance between inducers and inhibitors of calcium-phosphate deposits. Prevention of cardiac calcifications is at present mainly based of optimal control of serum phosphate and reduction of calcium load through the use of non-calcium containing phosphate binders. Treatment with statins for prevention and treatment of atherosclerosis is also an important means of decreasing the size and number of atherosclerotic plaques, where a portion of the calcification process develops.

Cardiac calcium evaluation in hemodialysis patients with multisection spiral computed tomography.

AIM: The aim of this study is cardiac calcium content evaluation in hemodialysis patients by a new technique, based on ultrafast multisection CT (MTC). METHODS: The study was carried out on 30 HD patients, 14 F and 16 M, average age 57.7 +/- 13.9 years, average HD age 57.3 +/- 47.4 months. The intact PTH levels were 625.4 +/- 571 pg/mL. Serum calcium, phosphate and CaxP product were 9.75 +/- 0.84 mg/mL, 6.21 +/- 1.01 mg/dL and 60.2 +/- 10.7 mg2/dL2, respectively. RESULTS: The values obtained with the MTC technique were reported in terms of Agatson scores. Score values frankly in the pathologic range (>100) were found in 24 patients (80%). Correlation analysis has shown positive and significant correlation coefficients of the score with patients' age (p = 0.003), serum calcium (p = 0.012), CaxP (p = 0.015), iPTH (p = 0.049), and borderline, to HD age (p = 0. 06). CONCLUSION: Risk factors for cardiac calcification are mainly age, degree of hyperparathyroidism, increased CaxP and serum calcium levels. A control of calcium phosphate parameters in hemodialysis patients seems to be mandatory to avoid increased severity of coronary artery disease.

Sphenoidal metastasis from prostate carcinoma. Case report and review of the literature.

A case of an uncommon sphenoidal metastasis from prostate carcinoma with cranial nerve involvement is described. Current concepts of metastatic spread of this tumor to the skull base, clinical signs and therapeutic approaches are reviewed in the light of the available literature.

Urinary deoxypyridinoline excretion for the evaluation of bone turnover in chronic renal failure.

BACKGROUND: The urinary excretion of deoxypyridinoline (DPD) was evaluated in predialysis chronic renal failure (CRF), together with intact PTH and several classic markers of bone turnover in order to assess whether urine free and total DPD excretion are equivalent parameters of bone turnover in CRF, and to evaluate the relationship between urine DPD excretion, PTH and the other bone markers. METHODS: The study was carried out in 94 patients with different degrees of renal failure due to various kidney diseases. Besides urinary DPD expressed as free DPD, total DPD, free/total DPD, free DPD/Cr and total DPD/Cr, the following determinations were made: intact PTH, bone alkaline phosphatase (BALP), total alkaline phosphatase (AP), osteocalcin (BGP), serum C-terminal telopeptide of collagen type I (ICTP) and hydroxyproline (OHpro). The patients were divided into 3 groups according to the increasing severity of renal failure (Ccr >40, 40-20, <20 ml/min). RESULTS: The ratio free/total DPD decreased (NS) with advancing renal failure, and was inversely correlated with total DPD excretion. While PTH increased progressively to about four times the values observed in the Ccr >40 group, there was a parallel increase only in BGP and ICTP, parameters retained in the serum with decreasing renal function, while AP, BALP, total DPD and OHpro did not change. However, significant correlations between total DPD/Cr and PTH, BALP, BGP and ICTP were also found. CONCLUSIONS: In CRF free DPD is an unreliable index of bone turnover due to a probable interference in its production from the peptide-bound DPD. Total DPD or total DPD/Cr are better used. In spite of the significant correlations observed in advanced renal failure between PTH and most of the parameters examined, a resistance of bone tissue to PTH action in CRF must be considered.

Solitary metastases to the cranial vault. Report of ten cases.

BACKGROUND: Metastatic spread of tumors to the skull is quite unusual and often represents a relevant diagnostic and therapeutic problem. Skull involvement can be observed in various neoplasms of epithelial origin (rarely in other tumors) and most often responsible are lung, breast, thyroid, kidney and prostate cancers. Less frequent than multiple involvement, single cranial vault lesions are often amenable to surgical resection instead of radiotherapy alone; scope of this paper is to highlight the key points of the management of such entities, including a brief review of the pathological and radiological features of these entities. METHODS: A retrospective study has enabled us to select from our files ten cases of surgically treated solitary cranial vault metastases, with a variable follow-up ranging from 6 months to 4 years. In all the cases the operation consisted in a monobloc resection and a cranioplasty for the repair of the defect. RESULTS: We have observed no perioperative morbidity or mortality; in all the cases surgery allowed histologic confirmation and immediate relief of neurological symptoms and cosmetic impairment (when present). CONCLUSIONS: Monobloc resection of solitary cranial vault metastatic lesions is an easy made and safe procedure, to be performed in every patient except the ones in poor general conditions, which are better addressed to radiotherapy alone.

Bone markers in the diagnosis of low turnover osteodystrophy in haemodialysis patients.

BACKGROUND: Renal osteodystrophy includes a number of low and high turnover bone histologic patterns which require a bone biopsy for their full identification. The role of intact PTH and several classical and more recent bone markers in the non-invasive diagnosis of renal bone disease in patients with CRF in HD requires further definition since available published data are limited. METHODS: In addition to intact PTH, alkaline phosphatase (AP) and osteocalcin (BGP), bone alkaline phosphatase isoenzyme (BALP), tartrate resistant acid phosphatase (TRAP), C-terminal cross-linked peptide of collagen type 1 (ICTP) and deoxypyridinoline (DPD) were measured in the serum of 41 patients on haemodialysis, subjected at the same time to transiliac bone biopsy for histomorphometric, histodynamic and aluminium histochemical examination. Histodynamic evaluation following double tetracycline label, was carried out in 37 patients. The patients had no evidence of active cytolytic and cholestatic liver disease and a history of very limited aluminium exposure. RESULTS: The patients had differing degrees of hyper-parathyroidism, with intact PTH ranging from normal to very elevated levels. Serum values of the markers BGP, ICTP and DPD, normally excreted through the kidneys, were on average very high. The correlation coefficients of the humoral parameters vs dynamic variables, such as BFR/BS, were high. The highest values were: intact PTH 0.798, AP 0.900, BALP 0.891, ICTP 0.807. The patients, grouped in low turnover osteodystrophy (LTO; 9), mixed osteodystrophy (MO; 9) and prevalent hyperparathyroidism (HP; 23), showed significant difference in the levels of most humoral and static and dynamic parameters (ANOVA). Bone aluminium histochemistry was negative in all cases. Discrimination of LTO patients from the other groups by humoral parameters, at the highest value of accuracy, showed 100% sensitivity and 93.7% specificity with a cut-off of 12.9 ng/ml for BALP; 88.9% sensitivity and 93.7% specificity with a cut-off of 21.5 ng/ml for DPD, and 88.9% sensitivity and 90.6% specificity with a cut-off of 79.7 pg/ml for intact PTH. The other markers had lower values. A standardized z-score approach for evaluation of all humoral parameters was also carried out. Using all variables, a correct classification of MO/HP and of LTO was possible in 93.8 and 88.9% of the cases, respectively. Predictive power was 96.8 and 80%, respectively for MO/HP and LTO. When the only variables used were intact PTH and BALP, a correct classification of MO/HP and LTO was possible in 90.6% and 88.9%, respectively. Predictive value of MO/HP was 96.7% and for LTO 72.7%. Predictive values using PTH and AP were 96.3% and 57.2%, respectively. CONCLUSION: Intact PTH and several relatively new bone markers are of certain value in the non-invasive diagnosis of renal osteodystrophy. However some of the humoral markers carry the same quality of information and the use of intact PTH and BALP may be adequate in the discrimination of bone histologic patterns. In cases exempt from liver disease, PTH and AP may be used as a less costly alternative. Bone biopsy could be chiefly limited to cases with borderline humoral values and to all those with a suspected aluminium overload.

The glucose transporter of Escherichia coli with circularly permuted domains is active in vivo and in vitro.

The bacterial phosphotransferase system (PTS) consists of two energy-coupling soluble proteins (enzyme I and HPr) and a large number of inner membrane transporters (enzymes II) that mediate concomitant phosphorylation and translocation of sugars and hexitols. The transporters consist of three functional units (IIA, IIB, IIC), which occur either as protein subunits or domains of a multidomain polypeptide. The membrane-spanning IIC domain contains the substrate binding site; IIA and IIB are phosphorylation domains that transfer phosphate from HPr to the transported sugar. The transporter complexes of the PTS are good examples for variation of design by modular assembly of domains and subunits. The domain order is IIC-IIB in the membrane subunit of the Escherichia coli glucose transporter (IICBGlc) and IIB-IIC in Salmonella typhimurium sucrose transporter (IIBCScr). The phosphorylation domain of IICBGlc was translocated from the carboxyl-terminal to the amino-terminal end of the IIC domain, and the activity of the circularly permuted form was optimized by variation of the length and the composition of the interdomain linker. IIBapCGlc with an alanine-proline-rich interdomain linker has 70% of the control specific activity after purification and reconstitution into proteoliposomes. These results indicate that the amino-terminal end of IICBGlc must be on the cytoplasmic side of the inner membrane, that membrane insertion of the IIC domain is insensitive to the modification of its amino-terminal end, and that a domain swap as it could occur by a single DNA translocation event can rapidly lead to a functional protein. However, IIB could not be substituted for by glucokinase. Fusion proteins between the IIC domain and glucokinase do not transport and phosphorylate glucose in an ATP-dependent mechanism, although the IIC moiety displays transport activity upon complementation with soluble subclonal IIB, and the glucokinase moiety retains ATP-dependent nonvectorial kinase activity. This indicates that IIC and IIB are two cooperative units and not only sequentially acting upon a common substrate, and that translocation of glucose must be conformationally coupled to the phosphorylation/dephosphorylation cycle of IIB.

Renal bone disease in 76 patients with varying degrees of predialysis chronic renal failure: a cross-sectional study.

BACKGROUND: Renal osteodystrophy has been studied less extensively in predialysis than in dialysis patients. Different types or histological patterns in their natural evolution from moderate to advanced severity of renal insufficiency are only partially known, with special regard to adynamic bone disease and its relationship with osteomalacia. METHODS: We conducted a cross-sectional retrospective study on 76 unselected patients with chronic renal failure undergoing conservative treatment, with a wide range of severity of renal insufficiency. All the patients were subjected to bone biopsy for histological and histomorphometric evaluation. The patients, 44 males and 32 females ranging in age from 18 to 72 years and with serum creatinine 1.2-11.4 mg/dl, had not been exposed to aluminium-containing drugs and had never been treated with vitamin D or calcitriol. RESULTS: Ten patients had normal bone, nine were diagnosed with adynamic bone disease, 26 with mild mixed osteodystrophy, seven with predominant osteomalacia, 22 with advance mixed osteodystrophy, and two with predominant hyperparathyroidism. Patients with adynamic bone disease had less severe chronic renal failure than the other pathological subgroups, intact PTH above the upper limit of normal, normocalcaemia, and reduced serum osteocalcin in line with a significantly lower ObS/BS. Osteomalacia was found in a more advanced stage of chronic renal failure with relative hypocalcaemia and more severe metabolic acidosis. A creatinine clearance of 20 ml/min served as a clear demarcation between this histological group and adynamic bone disease. CONCLUSIONS: It is postulated that adynamic bone disease is a form of renal osteodystrophy, separate from osteomalacia, appearing when bone resistance to PTH develops, probably a transient stage to more hyperparathyroid histological classes with increasing severity of chronic renal failure.

[Long-term assessment of bone loss in patients treated with GnRH agonists]. / Valutazione a lungo termine della perdita calcica ossea nelle pazienti trattate con GnRH Agonisti.

GnRH Analogues therapy of estrogen-dependent gynaecological diseases aims at suppression of physiologic ciclic ovaric function producing a hypogonadotropic condition. The first consequence of GnRH Analogues administration is hypoestrogenism; this condition permits the disease regression but, on the other, it causes a negative impact on bone metabolism particularly for prolonged therapeutic schemes (6 months). This study has evaluated the faculty of bone mass protection combining GnRH Analogues therapy with Ipriflavone that stimulates, both "in vivo" and "in vitro", Osteoblastic cells activity. The result of this study showed a significant bone loss in patients treated with GnRH Analogues only. The Ipriflavone association prevented bone loss.

Metabolic acidosis and osteodystrophic bone disease in predialysis chronic renal failure: effect of calcitriol treatment.

The role of metabolic acidosis on osteodystrophic bone lesions of chronic renal failure has been studied retrospectively in 24 patients, divided into two equal groups of 12, one with normal acid-base equilibrium (group A) and one with metabolic acidosis (group B). The two groups were found to differ significantly in serum levels of BGP (23.7 +/- 18 vs. 42.3 +/- 24 ng/ml, p < 0.02) and in several bone histomorphometric parameters such as osteoid volume (4.5 +/- 3.4 vs. 10.2 +/- 6.6%, p < 0.01), osteoid surface (27.7 +/- 18 vs. 48.4 +/- 19%, p < 0.01), single-labelled surface (7.94 +/- 2.9 vs. 15.8 +/- 9.9%, p < 0.02), mineralizing surface (60.69 +/- 26 vs. 30.89 +/- 15.8%, p < 0.003) and mineralization lag time (56.5 +/- 54 vs. 170.5 +/- 189 days, p < 0.05), with the acidotic group showing excess osteoid and a defect in mineralization. Osteomalacia was found only in the acidotic group, while the only 2 cases of adynamic bone disease (ABD) were in the nonacidotic group. Calcitriol administration, 0.25 micrograms daily for a period of 1 year, in 5 cases in group A and 6 cases in group B induced significant improvement of bone lesions mainly in group A. Two of these patients following treatment acquired the characteristics of ABD. In group B, the response to treatment was very limited, with 5 patients still showing persistence of the histological mixed type of bone disease. In conclusion, metabolic acidosis is accompanied by osteomalacia, pure or mixed variety, and shows a relative resistance to calcitriol administration. Normal acid-base equilibrium is more frequently associated with mild hyperparathyroidism and ABD, spontaneously or as a consequence of calcitriol administration.

Two-site immunoradiometric intact parathyroid hormone assay versus C-terminal parathyroid hormone in predicting osteodystrophic bone lesions in predialysis chronic renal failure.

Intact parathyroid hormone (iPTH) radioimmunoassay represents an important advancement in the measurement of serum PTH levels, permitting the evaluation of the actual rate of secretion of the parathyroid glands. The aim of the study was to compare the value of intact and C-terminal PTH measurements in predicting the osteodystrophic bone lesion in predialysis patients with chronic renal failure (CRF). We have studied 37 subjects with CRF who were receiving conservative treatment. In each subject a transiliac bone biopsy for histomorphometric examination was performed in addition to the assay of serum intact and C-terminal PTH, osteocalcin, and alkaline phosphatase. Serum C-terminal and intact PTH levels were closely correlated, both showing a high degree of correlation with serum osteocalcin. Similar degrees of correlation were observed between the two PTH assays and the histologic parameters osteoblastic surface (ObS/BS) and osteoclastic surface (OcS/BS). The evaluation of specificity and sensitivity of the two PTH assays in selecting patients with normal or pathologic histomorphometric parameters gave an equivalent number of false positive and negative cases. Based on discriminant analysis of histomorphometric parameters, intact PTH shows a higher discriminant power when compared with C-terminal PTH assay for the parameters OcS/BS and eroded surface (ES/BS), but without practical clinical value. In conclusion, in analogy to the short lived N-terminal PTH fragment assay, prediction of elementary hyperparathyroid bone lesions in predialysis CRF is not improved by the use of intact PTH as compared to the more traditional C-terminal assay.

Procollagen type I C-terminal extension peptide in predialysis chronic renal failure.

Collagen type 1 is the most abundant protein of bone. Serum levels of type 1 procollagen carboxy-terminal extension peptide (Procoll-1-C) may give a measure of the rate of synthesis of the collagen of bone and be therefore a marker of bone turnover. We have studied 38 patients with predialysis chronic renal failure; 14 of them were under long-term treatment with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] for prevention of secondary hyperparathyroidism. In all patients a transiliac bone biopsy for histomorphometry and determination of dynamic parameters was performed following double tetracycline labeling. In addition serum Procoll-1-C, intact and C-terminal parathyroid hormone (PTH), osteocalcin and alkaline phosphatase were determined. In the patients not receiving 1,25(OH)2D3, serum levels of Procoll-1-C were higher than normal. Procoll-1-C did not correlate with any of the humoral parameters, including serum creatinine, nor with static histomorphometric parameters. Contrarily to osteocalcin, the collagen type 1 marker correlated significantly with all dynamic parameters. Treatment with 1,25(OH)2D3 was accompanied by lower levels of osteocalcin, iPTH (n.s.), osteoblastic surface and by normal levels of Procoll-1-C (p < 0.001, compared to untreated patients), without substantial change in bone formation parameters (bone formation rate). In conclusion Procoll-1-C in predialysis chronic renal failure is a marker of bone turnover unparalleled by other markers. 1,25(OH)2D3 administration is associated with lower serum levels of the peptide unaccompanied by a decrement of bone formation parameters, therefore with an apparently better utilization of collagen type 1 in the mineralization process.(ABSTRACT TRUNCATED AT 250 WORDS)

Deferoxamine test and PTH serum levels are useful not to recognize but to exclude aluminum-related bone disease.

The use of noninvasive diagnostic tools, like the deferoxamine (DFO) test and serum iPTH, to identify aluminum-related bone disease has proved to be inadequate due to false-negative cases; therefore, bone biopsy becomes a necessary diagnostic procedure. Our purpose was to verify whether these non-invasive parameters, appropriately used, may result valid in the identification of patients not at risk of Al toxicity, therefore restricting the need for histologic evaluation. We studied 68 hemodialyzed patients, aged 49.0 +/- 11.6 years, with a M/F ratio of 37/31 and a dialytic age of 85.0 +/- 47.0 months, by means of bone biopsy, DFO test and serum C-PTH. 19.1% of the cases had positive stainable Al and/or high bone Al content (greater than 60 mg/kg/dw) and could be intoxicated. To obtain the highest sensitivity, we selected the following limit values: the lower limit of increment so far proposed for DFO test positivity (greater than 150 micrograms/l) and a value capable of selecting patients with pathologic osteoclasia for C-PTH (greater than 15 ng/ml). With these limits, four different groups of patients were recognized: group A, DFO test positive and PTH high, n = 12; group B, DFO test positive and PTH low, n = 6; group C, DFO test negative and PTH high, n = 30; group D, DFO test negative and PTH low, n = 20. In group B, which could be anticipated as being at higher risk, we actually found the highest (p less than 0.05) bone Al content as compared to other groups, associated with a reduced bone formation rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma insulin-like growth factor-1 and bone formation parameters in predialysis chronic renal failure.

Insulin-like growth factor-1 (IGF-1), produced by osteoblasts following parathormone (PTH) stimulation, is a local hormone with autocrine and paracrine functions on bone formation. To evaluate whether circulating IGF-1 is also important in stimulating bone formation, a study was carried out on 28 patients with slowly progressing nondialytic chronic renal failure. 9 patients were treated with 1,25(OH)2D3, while 19 did not receive vitamin D metabolites. In all patients a transiliac bone biopsy for histomorphometric studies was obtained, and the following determinations were made: immunoreactive PTH (iPTH), osteocalcin, alkaline phosphatase, IGF-1, serum calcium, phosphate and creatinine. Serum IGF-1 levels were similar in the two groups of patients, and higher than normal. iPTH and osteocalcin were positively correlated with serum creatinine, osteoblast surface and the eroded surface, but did not correlate with IGF-1. A negative (n.s.) relationship was found between dynamic bone parameters and circulating IGF-1, with the mineral apposition rate reaching a significant level (p less than 0.05). In conclusion, the circulating levels of IGF-1 are not correlated with bone formation parameters, thus apparently showing no role in bone turnover or dependency on bone production of the growth factor. The results may favor the hypothesis of a negative feedback control of circulating IGF-1 by suppressive signals originating from active bone metabolic units.