Bone turnover in children and adolescents with McCune-Albright syndrome treated with pamidronate for bone fibrous dysplasia

Bone fibrous dysplasia is one of the main features of McCune-Albright syndrome, a rare genetic condition caused by constitutive activating mutations of Gs-protein and defined by skin dysplasia, bone fibrous dysplasia, and autonomous multiple endocrinopathies. Raised serum alkaline phosphatase (ALP) and urinary hydroxyproline levels indicating bone metabolic hyperactivity have been reported in these patients. Encouraging therapeutic results have been achieved, mainly in adults, with pamidronate, an aminobisphosphonate. In this study we investigate newer bone metabolic indices in a cohort of 11 children and adolescents treated with pamidronate. Tenfold increases of bone ALP and urinary pyridinoline cross-links were found and osteocalcin levels were twofold higher compared with reference values. After treatment, significant decreases in bone ALP and cross-links (Wilcoxon test P < 0.06) were found. Bone mineral density (BMD) significantly increased during treatment. There were signs of radiological healing as thickening of the cortical bone was found in some cases.     

Atypical distant metastases from hypopharyngeal cancer

Hypopharyngeal squamous carcinoma is an aggressive disease with a high frequency of local and distant spread. Distant metastasis is seen more often now because of better loco-regional control due to more aggressive multimodal therapy. This article reports two cases of unusual metastatic disease from squamous carcinoma of pyriform sinus and reviews the metastatic disease in hypopharyngeal squamous cancers. The first was a case of metastatic pericardial effusion and the second was a metastasis to soft tissues of the scapular region and lung.     

Insulin-like growth factor-binding protein 1 stimulates human trophoblast migration by signaling through alpha 5 beta 1 integrin via mitogen-activated protein Kinase pathway

A highly migratory subpopulation of the human placental trophoblast, known as the extravillous trophoblast (EVT), invades the uterus and its vasculature, to establish adequate exchange of key molecules between the maternal and fetal circulations. During their formation, EVT cells selectively acquire alpha 5 beta 1 integrin. We had shown that alpha 5 beta 1 is required for their migratory function, and that EVT cell migration is stimulated by insulin-like growth factor-binding protein (IGFBP)-1 produced by the uterine decidua. The present study examined whether this stimulation is dependent on binding of the Arg-Gly-Asp (RGD) domain of IGFBP-1 to an RGD binding site on the alpha 5 beta 1 integrin, followed by activation of focal adhesion kinase (FAK) and stimulation of the mitogen-activated protein kinase (MAPK) pathway. IGFBP-1 treatment increased migration of EVT cells, whereas an anti-alpha 5 beta 1 integrin antibody blocked migration regardless of IGFBP-1 treatment. Migration stimulation by IGFBP-1 was abrogated by pretreatment with a Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP), but not a Gly-Arg-Gly-Glu-Ser-Pro (GRGESP) hexapeptide, and by mutation of the RGD domain of IGFBP-1 to Trp-Gly-Asp (WGD). IGFBP-1 treatment caused a rapid localization of immunoreactive FAK to cellular lamellipodia, a rapid increase in phosphorylation of FAK and extracellular-signal regulated kinases 1 and 2. Preincubation of EVT cells with Herbimycin A, a tyrosine kinase inhibitor, abrogated IGFBP-1 effects; whereas an MAPK kinase inhibitor, PD 98059, reduced migration regardless of IGFBP-1 treatment. These results indicate that IGFBP-1 stimulation of EVT cell migration occurs by binding of its RGD domain to the alpha 5 beta 1 integrin, leading to activation of FAK and stimulation of MAPK pathway.     

Pamidronate treatment of bone fibrous dysplasia in nine children with McCune-Albright syndrome

McCune-Albright syndrome is a rare genetic disorder consisting of skin and bone dysplasia and peripheral endocrinopathies. Little data have been collected regarding bisphosphonate treatment of bone fibrous dysplasia in paediatric patients with this syndrome. The aim of our study was to investigate the therapeutic efficacy of pamidronate in these patients. Nine patients with moderate to severe forms of bone fibrous dysplasia were treated with pamidronate intravenously (0.5-1 mg/kg/daily for 2-3 d) at 0.5-1-y intervals. Patients were treated over a time period of 0.5-3.5 y. During treatment no spontaneous fracture occurred. Bone pain and gait abnormality due to pain disappeared after 2-3 therapeutic cycles. Cranial asymmetry and limb length discrepancy remained unchanged. Elevated serum alkaline phosphatase and urine hydroxyproline values were reduced by the treatment, demonstrating drug activity at the lesional level. The effectiveness of pamidronate was also seen at the non-lesional level through an increase in bone density. Radiographic and scintigraphic evidence of lesion healing was not attained. Pamidronate treatment can ameliorate the course of bone fibrous dysplasia in children and adolescents with McCune-Albright syndrome.     

Eradication of spontaneous and experimental adenocarcinoma metastases with chronic indomethacin and intermittent IL-2 therapy

We had earlier shown that tumor-bearing results in an inactivation of IL-2–dependent effector cells by host macrophagederived PGE₂, and that chronic indomethacin therapy (CIT) aimed at blocking prostaglandin synthesis, combined with multiple rounds of IL-2, can cure experimental metastases of a variety of tumors in mice. We have now tested the efficacy of this therapy on spontaneous as well as experimental metastasis of C3–L5 mammary adenocarcinoma in C3H/HeJ mice. Mice transplanted s.c. with C3–L5 cells (and showing visible spontaneous lung metastases between days 7 and 10) were given CIT starting on day 15, plus 2 5–day rounds of IL-2 or IL-2 alone. Mice injected i.v. with 10⁴ C3–L5 cells (and showing lung micrometas-tases on day 5) were placed on CIT on day 5 and given 3 5–day rounds of IL-2 or treated with IL-2 alone. Control mice received vehicles alone. Results revealed that combined CIT + IL-2 therapy in the spontaneous metastasis model caused a regression of primary tumors, a marked reduction in lung metastases scored on days 25–35 and a marked prolongation of host survival (79% cured). Survivors rechallenged with 10⁴ tumor cells i.v. on day 210 resisted tumor growth. In the experimental metastasis model, this therapy also markedly reduced lung metastases and prolonged animal survival (50% cured). In both models, the combination therapy led to the presence of highly active tumoricidal (for C3–L5 and YAC-I lymphoma targets) lymphocytes with AGM-I⁺, Lyt-2^- and Thy-l± phenotype and macrophages in the spleen and the lungs, and ADCC-promoting activity in the serum. CIT + IL-2 therapy can thus effectively eradicate spontaneous and experimental mammary adenocarcinoma metastasis in mice. It activates natural effector cells in situ, generates ADCC-promoting activity in the serum and results in resistance to umor take in this moderately immunogenic tumor model.     

Nitric oxide promotes murine mammary tumour growth and metastasis by stimulating tumour cell migration, invasiveness and angiogenesis

The contributory role of nitric oxide (NO) on tumour growth and metastasis was evaluated in a murine mammary tumour model. NO synthase (NOS) protein expression levels were examined in spontaneously arising C3H/HeJ mammary adenocarcinomas and respective lung metastases. In addition, 2 clonal derivatives of a single spontaneous tumour differing in metastatic phenotype (C3L5 and C10; highly and weakly metastatic, respectively) were utilised to investigate (i) the relationship between NOS expression levels and the biological behaviour of tumour cells (e.g., in vitro migratory and invasive capacities, in vivo tumour growth rate and metastatic and angiogenic capacities) and (ii) whether tumour-derived NO stimulated the invasive, migratory and angiogenic capacities of tumour cells. A heterogeneous pattern of endothelial NOS (eNOS) expression was observed in tumour cells in spontaneous primary tumours, and eNOS expression was higher in undifferentiated relative to differentiated tumour zones. However, tumour cells in lung metastatic sites were always strongly eNOS-positive, suggesting that eNOS expression facilitated metastasis. Findings using clonal derivatives supported this notion; s.c. primary tumour growth rate, efficiency of spontaneous metastasis and eNOS expression were higher for C3L5 relative to C10 cell lines. Nevertheless, lung metastases derived from both tumour cell lines were always strongly and homogeneously eNOS-positive. C3L5 cells were more invasive than C10 cells in vitro, but the migratory capacities of the cell lines did not differ. However, migration and invasiveness of both cell lines were inhibited with L-NAME and restored with excess L-arginine. Tumour-associated angiogenesis, measured in Matrigel implants inclusive of tumour cells, was higher for C3L5 relative to C10 cells, and C3L5-induced angiogenesis was reduced with chronic L-NAME treatment of host animals. These findings suggest that tumour-derived eNOS promoted tumour growth and metastasis by multiple mechanisms: stimulation of tumour cell migration, invasiveness and angiogenesis.     

Testicular microlithiasis: an unreported feature of McCune-Albright syndrome in males

OBJECTIVE: To ascertain the incidence of testicular microlithiasis (TM) in boys with McCune-Albright syndrome (MAS). STUDY DESIGN: Study population consisted of 8 boys with MAS whose medical records were reviewed with emphasis on their past genitourinary histories. All of the boys underwent a clinical and ultrasonographic (US) scanning of the scrotal and inguinal regions. US results in boys with MAS were compared with those obtained in two control populations consisting of 20 healthy subjects and 12 boys with idiopathic and untreated central precocious puberty (CPP). RESULTS: Clinical examination revealed urological abnormalities in no patients, whereas US showed a typical picture of TM in 5 of 8 boys. TM was observed in none of the subjects belonging to control populations (v=15.2 and 11.3, respectively; P <.001). CONCLUSIONS: In a series of 8 boys with MAS we demonstrated a high prevalence (62%) of TM that was associated with neither malignant nor nonmalignant conditions. This finding is unlikely to be only occasional, considering the very low prevalence of TM reported until now in healthy children and young adults and in our results in control populations. TM may be another marker for MAS.     

Kidney-bone, bone-kidney, and cell-cell communications in renal osteodystrophy

The relationship between bone and the kidney in renal osteodystrophy is a complex interplay of kidney to bone connections, bone to kidney connections, and cell to cell connections. In addition, such interactions have a profound effect on the vasculature. In this review, we discuss the role of the bone morphogenetic proteins (BMPs) in the skeleton, kidney, and vasculature. In addition, we propose that deficiencies of these BMPs seen in chronic kidney disease (CKD) result in decreased bone remodeling and a compensatory secondary hyperparathyroidism (high turnover state). Treatment of the hyperparathyroidism blocks this compensatory arm and thus decreased bone remodeling occurs (low turnover). We review animal models of CKD in which treatment with BMP-7 resulted in normalization of both high and low turnover states. Finally, we discuss vascular calcification as it relates to bone metabolism. We discuss the roles of BMP-7 and 2 other bone regulatory proteins, osteoprotegerin (OPG) and alpha2-HS glycoprotein (AHSG, human fetuin), in the human vasculature and their implications for vascular calcification.     

Pharmacokinetic and pharmacodynamic studies on interaction of "Trikatu" with diclofenac sodium

"Trikatu"-an Ayurvedic formulation comprising of a 1:1:1 ratio of dried fruits of Piper nigrum, Piper longum and dried rhizomes of Zingiber officinale is widely used to enhance the bioavailability of drugs, like vasicine, indomethacin, etc. The enhanced biological response might lead to alteration of therapeutic regimens of commonly prescribed drugs. The present work was aimed to study the effect of concomitant administration of Trikatu on the pharmacokinetics and pharmacodynamics of diclofenac sodium, a frequently prescribed non-steroidal anti-inflammatory drug, having a poor oral bioavailability (54 +/- 2%). The effect of Trikatu on the bioavailability profile of diclofenac sodium was studied in rabbits. It was observed that Trikatu significantly decreased the serum levels of diclofenac sodium. The pharmacodynamic study was carried out to evaluate the effect of Trikatu on the anti-inflammatory activity of diclofenac sodium using carragenin-induced rat paw edema model. It was observed that the mean percent edema inhibition shown by the combination of Trikatu and diclofenac was similar to that shown by Trikatu alone but significantly less than that shown by diclofenac alone. Thus, the experimental findings indicated that Trikatu pretreatment might decrease the bioavailability of certain drugs probably through a drug-herb interaction thereby adversely affecting the therapeutic efficacy of these drugs.