Efectos adversos de los bisfosfonatos

Bone-Targeted Bortezomib Inhibits Bortezomib-Resistant Multiple Myeloma in Mice by Providing Higher Levels of Bortezomib in Bone

Limited treatment options exist for cancer within the bone, as demonstrated by the inevitable, pernicious course of metastatic and blood cancers. The difficulty of eliminating bone-residing cancer, especially drug-resistant cancer, necessitates novel, alternative treatments to manipulate tumor cells and their microenvironment, with minimal off-target effects. To this end, bone-targeted conjugate (BP-Btz) was generated by linking bortezomib (Btz, an anticancer, bone-stimulatory drug) to a bisphosphonate (BP, a targeting ligand) through a cleavable linker that enables spatiotemporally controlled delivery of Btz to bone under acidic conditions for treating multiple myeloma (MM). Three conjugates with different linkers were developed and screened for best efficacy in mouse model of MM. Results demonstrated that the lead candidate BP-Btz with optimal linker could overcome Btz resistance, reduced tumor burden, bone destruction, or tumor metastasis more effectively than BP or free Btz without thrombocytopenia and neurotoxicity in mice bearing myeloma. Furthermore, pharmacokinetic and pharmacodynamic studies showed that BP-Btz bound to bone matrix, released Btz in acidic conditions, and had a higher local concentration and longer half-life than Btz in bone. Our findings suggest the potential of bone-targeted Btz conjugate as an efficacious Btz-resistant MM treatment mechanism. © 2021 American Society for Bone and Mineral Research (ASBMR).

Ultrastructural changes in giant cell tumor of bone cultured cells exposed to quercetin

Giant cell tumor of bone (GCTB) is a primary bone tumor that affects skeletally mature people and whose main treatment is surgical. Because there are few pharmacological alternatives for the treatment of this tumor to find other molecules or compounds that could be potential therapeutic agents is desirable. Quercetin is a flavonoid with described antitumoral effect in different types of cancer cell lines that could be a possible option in GCTB treatment. However, there is no literature about the effect of quercetin on GCTB. In the present paper, we reported the ultrastructural changes in GCTB cells exposed to quercetin and also determined the expression of RIP1K, Caspase 3 and Caspase 8 on the exposed cells. For this purpose, GCTB sample was obtained from one patient and cultured. Quercetin affected all the histological components of the GCTB. The ultrastructural changes consisted mainly in necroptosis, autophagocytosis and secondary necrosis. This is the first report about quercetin effects on giant cell tumor of bone cultured cells. Further studies in other models could be done to support the use of quercetin as a complementary treatment in giant cell tumor of bone.Abbreviations: Giant cell tumor of bone (GCTB); transmission electron microscopy (TEM); reverse transcription - polymerase chain reaction (RT-PCR); receptor interacting protein kinase 1 (RIP1K); Dulbecco's Modified Eagle's Medium (DMEM).

Orthogeriatric activity in a general hospital of Castilla-La Mancha, Spain

AIM

To describe the orthogeriatric activity in the elderly with hip fractures in the Hospital Mancha Centro, based on the recommendations of the main guidelines.

MATERIAL AND METHOD

Observational prospective study, comprising all patients over 65 years of age admitted to the Traumatology Unit with a hip fracture between April 2015 and December 2015. Patients were admitted under the care of the Traumatology Unit with cross-consultation carried out with the Geriatrics Department, which then carried out a pre-operative geriatric assessment and the post-operative follow-ups.

RESULTS

The mean pre-surgery waiting time was 48h and the overall time in hospital was 10.3±8.2 days. Patients who suffered from delirium (42.1%) did not improve as well, and were referred to nursing homes. Blood transfusions were received by 54.7% of the patients, despite 53.5% of them having received intravenous and/or oral iron after the surgery. Treatment with calcium and vitamin D was prescribed in 79% of the patients on discharge. The Rehabilitation Unit assessed 36% of the patients, with 4.8% fully, and 16.7% partially recovering their prior functional status. Upon discharge, 55% of the patients returned to their homes, and 22% were referred to short-term assisted living facilities.

DISCUSSION

This article describes how the main clinical problems are handled in the elderly with hip fractures in our hospital, based on recommendations of the main guidelines and publications.

CONCLUSIONS

Our hospital follows the recommended guidelines. Aspects for improvement include the management of anaemia during admission and rehabilitation.

Temporal course of avascular femoral head necrosis in patients with pemphigus vulgaris

BACKGROUND AND OBJECTIVES

Pemphigus vulgaris (PV) is typically treated with systemic corticosteroids and immunosuppressive agents. Avascular necrosis (AVN) of the femoral head is a well-recognized major complication of corticosteroid therapy. The characteristics of this serious complication in PV remain unknown.

PATIENTS AND METHODS

Uncontrolled, retrospective study of all PV-related AVN cases diagnosed at an Iranian autoimmune bullous disease clinic between 1985 and 2013.

RESULTS

Of the 2,321 medical records of PV patients reviewed, 45 (1.93 %) cases showed femoral AVN, with 30 (66.7 %) individuals being male. The mean age at diagnosis of AVN was 47.4 ± 14.2 years. The mean interval between the diagnosis of PV and the onset of AVN was 25.3 ± 18.3 months. With the exception of eight cases (17.8 %), the majority of patients developed AVN within three years after the diagnosis of PV. The mean cumulative dose of prednisolone in patients with AVN was 13,115.8 ± 7041.1 mg. There was a strong correlation between the total prednisolone dose and the time of onset of AVN (p = 0.001). In patients with a history of alendronate intake, that interval was significantly shorter (p = 0.01).

CONCLUSIONS

Occurring in about 2 % of patients, AVN is a serious complication of corticosteroid treatment in patients with PV, predominantly in the first three years of treatment. In individuals receiving higher doses of prednisolone, AVN tends to occur earlier.

Bone homeostasis and breast cancer: implications for complex therapy and the maintenance of bone integrity

The standard of care in bone metastases is antiresorptive therapy. If present in the bone, tumor cells induce a vicious cycle by stimulating the osteoclasts, which further accelerates tumor progression. The widely-used bisphosphonates or the new therapeutic option, denosumab an inhibitor of the receptor activator of NF-κB ligand (RANKL), interrupt this vicious cycle, inhibit tumor growth, and in clinical practice prevent skeleton-related events. Adjuvant oncological therapy, including chemotherapy and endocrine manipulations (ovarian ablation and tamoxifen in premenopausal, and aromatase inhibitors in postmenopausal women), increases the bone turnover and the risk of fracture. Awareness is essential for the diagnosis and treatment of cancer therapy-induced bone loss, or its prevention with appropriate calcium and vitamin D supplementation. A new possibility has been suggested for the prevention of relapse: the use of bisphosphonates in the adjuvant setting. Three large studies and their meta-analyses indicate that the inhibition of bone remodeling prevents the growth of dormant tumor cells and cancer relapse in the population of postmenopausal patients with a low-estrogen environment in the skeleton. The similar potential of a RANKL inhibitor is currently under evaluation. Since the maintenance of bone integrity is necessary for the prevention of both therapy-related side-effects and progression of the disease, the management of breast cancer at any stage requires a careful consideration of the bone homeostasis.

[2011 Up-date of the consensus statement of the Spanish Society of Rheumatology on osteoporosis]

OBJECTIVE

Due to increasing improvement in the diagnosis, evaluation and management of osteoporosis and the development of new tools and drugs, the Spanish Society of Rheumatology (SER) has promoted the development of recommendations based on the best evidence available. These recommendations should be a reference to rheumatologists and other health professionals involved in the treatment of patients with osteoporosis.

METHODS

Recommendations were developed following a nominal group methodology and based on a systematic review. The level of evidence and degree of recommendation were classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through Delphi technique. Evidence from previous consensus and available clinical guidelines was used.

RESULTS

We have produced recommendations on diagnosis, evaluation and management of osteoporosis. These recommendations include the glucocorticoid-induced osteoporosis, premenopausal and male osteoporosis.

CONCLUSIONS

We present the SER recommendations related to the biologic therapy risk management.