How to achieve the desired outcomes of advance care planning in nursing homes: a theory of change.

BACKGROUND: Advance care planning (ACP) has been identified as particularly relevant for nursing home residents, but it remains unclear how or under what circumstances ACP works and can best be implemented in such settings. We aimed to develop a theory that outlines the hypothetical causal pathway of ACP in nursing homes, i.e. what changes are expected, by means of which processes and under what circumstances. METHODS: The Theory of Change approach is a participatory method of programme design and evaluation whose underlying intention is to improve understanding of how and why a programme works. It results in a Theory of Change map that visually represents how, why and under what circumstances ACP is expected to work in nursing home settings in Belgium. Using this approach, we integrated the results of two workshops with stakeholders (n = 27) with the results of a contextual analysis and a systematic literature review. RESULTS: We identified two long-term outcomes that ACP can achieve: to improve the correspondence between residents' wishes and the care/treatment they receive and to make sure residents and their family feel involved in planning their future care and are confident their care will be according to their wishes. Besides willingness on the part of nursing home management to implement ACP and act accordingly, other necessary preconditions are identified and put in chronological order. These preconditions serve as precursors to, or requirements for, accomplishing successful ACP. Nine original key intervention components with specific rationales are identified at several levels (resident/family, staff or nursing home) to target the preconditions: selection of a trainer, ensuring engagement by management, training ACP reference persons, in-service education for healthcare staff, information for staff, general practitioners, residents and their family, ACP conversations and documentation, regular reflection sessions, multidisciplinary meetings, and formal monitoring. ONCLUSIONS: The Theory of Change map presented here illustrates a theory of how ACP is expected to work in order to achieve its desired long-term outcomes while highlighting organisational factors that potentially facilitate the implementation and sustainability of ACP. We provide the first comprehensive rationale of how ACP is expected to work in nursing homes, something that has been called for repeatedly.

Problematic alcohol and other substance use among patients presenting to emergency services in South Africa: Who is ready for change?

BACKGROUND: Studies that identify factors associated with intervention uptake are urgently needed in poorly resourced healthcare systems. This is important, as knowing who is likely to engage may lead to intervention targeting, which is an efficient use of scarce health resources. OBJECTIVE: To identify patient characteristics that predict the acceptance of a brief intervention for substance use delivered in emergency departments (EDs). METHODS: Patients presenting to three EDs were screened for substance use using the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST). All patients identified as at risk for substance use problems were offered a brief psychotherapy intervention focused on substance user education. Data were collected on patients' age, sex, presenting condition (injury/no injury), type of substance used, and severity of substance use. Logistic regression analysis was used to identify variables that predicted acceptance of the offer of a brief intervention. RESULTS: Being between the ages of 25 and 39 years increased the likelihood of accepting an offer of help compared with 18 - 24-year-olds. Polysubstance users were less likely to accept an offer of help than patients with problematic alcohol use only, while patients with higher ASSIST scores were more likely to accept an offer of help than those with lower scores. CONCLUSIONS: Findings suggest that more work is needed to understand the mechanisms underlying treatment acceptance. Brief interventions delivered in ED services in countries such as South Africa should target alcohol users with higher ASSIST scores in order to ensure the efficient use of scarce health resources.

Validity and diagnostic accuracy of the Luganda version of the 9-item and 2-item Patient Health Questionnaire for detecting major depressive disorder in rural Uganda.

BACKGROUND: The prevalence of depression in rural Ugandan communities is high and yet detection and treatment of depression in the primary care setting is suboptimal. Short valid depression screening measures may improve detection of depression. We describe the validation of the Luganda translated nine- and two-item Patient Health Questionnaires (PHQ-9 and PHQ-2) as screening tools for depression in two rural primary care facilities in Eastern Uganda. METHODS: A total of 1407 adult respondents were screened consecutively using the nine-item Luganda PHQ. Of these 212 were randomly selected to respond to the Mini International Neuropsychiatric Interview diagnostic questionnaire. Descriptive statistics for respondents' demographic characteristics and PHQ scores were generated. The sensitivity, specificity and positive predictive values (PPVs), and area under the ROC curve were determined for both the PHQ-9 and PHQ-2. RESULTS: The optimum trade-off between sensitivity and PPV was at a cut-off of ≧5. The weighted area under the receiver Operating Characteristic curve was 0.74 (95% CI 0.60-0.89) and 0.68 (95% CI 0.54-0.82) for PHQ-9 and PHQ-2, respectively. CONCLUSION: The Luganda translation of the PHQ-9 was found to be modestly useful in detecting depression. The PHQ-9 performed only slightly better than the PHQ-2 in this rural Ugandan Primary care setting. Future research could improve on diagnostic accuracy by considering the idioms of distress among Luganda speakers, and revising the PHQ-9 accordingly. The usefulness of the PHQ-2 in this rural population should be viewed with caution.

TACC3 deregulates the DNA damage response and confers sensitivity to radiation and PARP inhibition.

Deregulation of the transforming acidic coiled-coil protein 3 (TACC3), an important factor in the centrosome-microtubule system, has been linked to a variety of human cancer types. We have recently reported on the oncogenic potential of TACC3; however, the molecular mechanisms by which TACC3 mediates oncogenic function remain to be elucidated. In this study, we show that high levels of TACC3 lead to the accumulation of DNA double-strand breaks (DSBs) and disrupt the normal cellular response to DNA damage, at least in part, by negatively regulating the expression of ataxia telangiectasia mutated (ATM) and the subsequent DNA damage response (DDR) signaling cascade. Cells expressing high levels of TACC3 display defective checkpoints and DSB-mediated homologous recombination (HR) and non-homologous end joining (NHEJ) repair systems, leading to genomic instability. Importantly, high levels of TACC3 confer cellular sensitization to radiation and poly(ADP-ribose) polymerase (PARP) inhibition. Overall, our findings provide critical information regarding the mechanisms by which TACC3 contributes to genomic instability, potentially leading to cancer development, and suggest a novel prognostic, diagnostic and therapeutic strategy for the treatment of cancer types expressing high levels of TACC3.

HIV/AIDS and Mental Health Research in Sub-Saharan Africa: a Systematic Review

The relationship between mental illness and HIV/AIDS is complex and bidirectional. A significant amount of research has been performed in high-income countries but less is known about HIV and mental health in sub-Saharan Africa. The objectives of the review were to search the literature for quantitative studies conducted in sub-Saharan Africa on mental health and HIV and to critically evaluate and collate the studies in order to identify research needs and priorities. The databases Ovid; MEDLINE; PsycINFO and the Social Sciences Citation Index (SSCI) were searched for variations of search terms related to HIV/AIDS and mental health and studies limited to the populations of African countries. In addition; we hand-searched indexes of key journals and the databases of academic theses. We included 104 papers or research publications. The majority of these were published after 2005. The major topics covered were: mental-health-related HIV-risk behaviour; HIV in psychiatric populations; and mental illness in HIV-positive populations. The reported prevalence levels of mental illness among people living with HIV or AIDS (PLHIV) was high; with all but one study noting a prevalence of 19or higher. Neurocognitive changes in adults with HIV were also prevalent; with reported deficits of up to 99in symptomatic PLHIV and 33in non-symptomatic PLHIV. Research on HIV in relation to mental health is increasing; however; there is a need for good-quality prospective studies to investigate the bidirectional effects of mental illness and HIV on each other

[Novel prognostic marker in invasive breast cancer. ITIH5 expression is abrogated by aberrant promoter methylation]. / Neuer Prognosemarker beim invasiven Mammakarzinom. ITIH5-Expression wird über aberrante Promotormethylierung inaktiviert.

We have recently characterized ITIH5 as a new extracellular matrix protein that exhibits clear expression loss in a variety of human tumour entities, including breast cancer. The aim of the present study was to decipher the molecular cause of ITIH5 expression loss in breast cancer and to learn more about the possible role of this molecule in cancer diseases. ITIH5 protein expression was found to be strongly reduced in 42% of invasive breast carcinomas-interestingly, with significant association with poor patient outcome. ITIH5 promoter methylation was frequently detected in breast cell lines and in primary carcinomas (40%), and it was functionally correlated with loss of ITIH5 mRNA expression. Moreover, ITIH5 promoter methylation was also significantly associated with poor clinical patient outcome and also with the occurrence of lymph node and distant metastases. In conclusion, we propose that ITIH5 may represent a novel metastasis repressor in human breast cancer. Both ITIH5 protein expression and ITIH5 promoter methylation may serve as prognostic biomarkers, thereby helping improve clinical patient outcome.

The extracellular matrix protein ITIH5 is a novel prognostic marker in invasive node-negative breast cancer and its aberrant expression is caused by promoter hypermethylation.

Inter-alpha-trypsin inhibitors (ITIs) are protease inhibitors stabilizing the extracellular matrix. ITIs consist of one light (bikunin) and two heavy chains (ITIHs). We have recently characterized ITIH5, a novel member of the ITIH gene family, and showed that its messenger RNA is lost in a high proportion of breast tumours. In the present study, an ITIH5-specific polyclonal antibody was generated, validated with western blot and used for immunohistochemical analysis on a tissue microarray; ITIH5 was strongly expressed in epithelial cells of normal breast (n=11/15), while it was lost or strongly reduced in 42% (92/217) of invasive breast cancers. ITIH5 expression in invasive carcinomas was associated with positive expression of oestrogen receptor (P=0.008) and histological grade (P=0.024). Correlation of ITIH5 expression with clinical outcome revealed that patients with primary tumours retaining abundant ITIH5 expression had longer recurrence-free survival (RFS; P=0.037) and overall survival (OS; P=0.044), compared to those with reduced expression (mean RFS: 102 vs 78 months; mean OS: 120 vs 105 months). Methylation-specific PCR analysis frequently showed strong methylation of the ITIH5 promoter in primary breast tumours (41%, n=109) and breast cancer cell lines (n=6). Methylation was significantly associated with mRNA loss (P<0.001; n=39), and ITIH5 expression was induced after treatment of tumour cell lines with the demethylating agent 5-aza-2'-deoxycytidine. Moreover, ITIH5 promoter methylation was significantly associated with reduced OS (P=0.008). The cellular function of ITIH5 was evaluated by forced expression of a full-length ITIH5 complementary DNA in the breast cancer cell line MDA-MB-231, which does not endogenously express ITIH5. ITIH5-expressing clones showed a 40% reduced proliferation rate compared to mock-transfected cells. Overall, these data show that promoter methylation-mediated loss of ITIH5 expression is associated with unfavourable outcome in breast cancer patients, and thus ITIH5 could be used as a prognostic marker, although this marker is not multivariate independent due to its close association with ER expression. Our data indicate that ITIH5 is a candidate class II tumour suppressor gene and could be involved in tumour progression, invasion and metastasis, as its absence is associated with increased proliferation rates and a prognostic value indicating poor clinical outcome.

Antibacterial substances of low molecular weight isolated from the blowfly, Lucilia sericata.

Low molecular weight compounds were isolated by high-performance liquid chromatography from the maggot or haemolymph extracts of Lucilia sericata (Meigen) (Diptera: Calliphoridae). Using gas chromatography-mass spectrometry analysis, three compounds were obtained: p-hydroxybenzoic acid (molecular weight 138 Da), p-hydroxyphenylacetic acid (molecular weight 152 Da) and octahydro-dipyrrolo[1,2-a;1',2'-d] pyrazine-5,10-dione (molecular weight 194 Da), also known as the cyclic dimer of proline (or proline diketopiperazine or cyclo[Pro,Pro]). All three molecules revealed antibacterial activity when tested against Micrococcus luteus and/or Pseudomonas aeruginosa, and the effect was even more pronounced when these molecules were tested in combination and caused lysis of these bacteria.

Supercontinuum generation system for optical coherence tomography based on tapered photonic crystal fibre.

We report smooth and broad continuum generation using a compact femtosecond Ti:Sapphire laser as a pump source and a tapered photonic crystal fibre as a nonlinear element. Spectral output is optimized for use in optical coherence tomography, providing a maximum longitudinal resolution of 1.5 microm in free space at 809 nm centre wavelength without use of additional spectral filtering.

Drill cutting accumulations in the Northern and Central North Sea: a review of environmental interactions and chemical fate.

The exploration and production of North Sea oil and gas reserves has resulted in the accumulation of large quantities of drill cuttings on the seabed surrounding drill sites. This complex mixture of man-made and natural substances contains higher concentrations of certain metals (Ba, Cr, Cu, Ni, Pb, and Zn) and hydrocarbons than are observed in background sediments. With decommissioning of older platforms underway, an evaluation of the environmental interactions and chemical fate of the drill cuttings accumulations is required. This review concentrates on contaminants within drill cutting accumulations in the Northern and Central North Sea (56 degrees N-62 degrees N). Present literature reviewed reveals that hydrocarbons within the cuttings piles remain relatively unchanged with time. A considerable proportion of the associated contaminants are likely to remain within the cuttings pile unless they are disturbed which will then increase exchanges of porewater and solids back to the seabed surface resulting in pathways of exposure for organisms.

Primary breast cancer therapy in six regions of Germany.

Studies from six regions of Germany (Aachen (W1), Dresden (E1), Jena (E2), Marburg (W2), Munich (W3), and Stuttgart (C1)) have been compared to verify and assess the quality of healthcare using breast cancer as an example. All of the data collection was carried out in comprehensive cancer centres and is population-based, with the exception of C1. Classic prognostic factors and the initial treatment of 8661 women with breast cancer, diagnosed between 1996 and 1998, were examined. Primary therapy, breast conserving therapy (BCT), and the use of subsequent local radiation and/or systemic therapy (chemotherapy or hormonal therapy) were analysed. BCT was performed on 39.3-57.7% of patients. By pT-category, the proportion of BCT in the six regions were as follows: for pTis between 37.8 and 64.3%, for pT1 between 51.7 and 71.5%, for pT2 between 25.9 and 51.1%, for pT3 between 0 and 13.1% and for pT4 between 0 and 15.2%. Multivariate analyses, adjusted for age and biological factors, showed a significant influence of the treating hospital on the mastectomy rate. The use of radiotherapy after BCT (80%) was quite homogeneous in the six regions. The application of radiotherapy after mastectomy, however, varied between 10.4 and 32.2%. In all regions, for premenopausal patients, the use of adjuvant systemic therapy almost reflected the St. Gallen-Consensus recommendations. In contrast, post-menopausal women with positive lymph nodes were not always treated according to these standards. In all regions, age had an influence on the administration of treatment: elderly breast cancer patients received less BCT, less radiotherapy and less adjuvant therapy than recommended in the St. Gallen-Consensus. Feedback of the results was made available to each hospital, providing a comparative summary of patient care that could be used by the participating hospitals for self-assessment and quality-control.

High reactivity of alkyl sulfides towards epoxides under conditions of collagen fixation--a convenient approach to 2-amino-4-butyrolactones.

Epoxy crosslinking agents have been investigated for use in the fabrication of bioprosthetic devices, such as heterograft heart valve prostheses. It has been generally assumed that epoxy crosslinking takes place via amino-epoxy reactions. The present study investigated the hypothesis that the reactions of methionine residues with epoxides also can occur in biomaterial crosslinking. A series of model reactions were studied in which a mono-epoxide was combined with individual alkyl sulfides. In the present studies epoxides rapidly alkylate aliphatic sulfides, including methionine derivatives, in buffered aqueous solutions at room temperature and pH close to neutral, forming sulfonium compounds, which are stable at pH 5-7 at temperatures up to 50 degrees C, except for cases in which methionine derivatives with non-protected carboxy groups are used. The rate of reaction remains practically unchanged within the range of pH from 5 to 12, whereas in strongly alkaline media the reverse reaction occurs. This discovery can provide a better understanding of processes occurring in the fixation of bioprosthetic tissues with polyepoxides. It can also develop into a site-specific method to label methionine residues in proteins. The carboxy group-containing sulfonium betaines derived from N-protected methionines undergo cyclization in unexpectedly mild conditions, which can be used as an efficient method for preparation of N-protected 2-amino-4-butyrolactones with sensitive protective groups.

[Solitary fibrous thoracic wall tumor. Progression with percutaneous radiotherapy]. / Solitärer fibröser Thoraxwandtumor. Progredienz unter perkutaner Radiatio.

HISTORY AND CLINICAL FINDINGS: A 81-year-old patient free of pain was referred to the university hospital for further evaluation and therapy of tumour masses in the right thorax. Clinical examination revealed dullness to percussion and reduced breathing in the right lower lung. INVESTIGATIONS: Computed tomography showed an enlarged solid tumour mass attached to the thoracic cavity and pleural effusion on the right side. Quantification of pulmonary perfusion presented significant defects in the right upper and middle lobe. DIAGNOSIS, TREATMENT AND COURSE: The pulmonary masses were biopsied under CT-guidance. Biopsy and immunohistochemical findings proved a malignant solitary fibrous tumour of the chest wall, a mesenchymal tumour of its own entity. Because of pain in the right arm and because of missing other reliable therapeutic options a palliative irradiation was performed. The tumour did increase in size due to radiotherapy and a severe right ventricular heart failure occurred. The patient died 5 months after diagnosis has been made. Autopsy revealed a transition of tumour cells to sarcomatic growth. CONCLUSION: In our case we conclude an accelerated progression of the solitary fibrous chest wall tumour in the course of irradiation. Whether the development of sarcomatic growth occurred as a result of radiotherapy remains speculative.

Different usage of the glycosaminoglycan attachment sites of biglycan.

Biglycan is a member of the small leucine-rich proteoglycan family. Its core protein comprises two chondroitin/dermatan sulfate attachment sites on serine 42 and serine 47, respectively, which are the fifth and tenth amino acid residues, respectively, after removal of the prepro peptide. Because the regulation of glycosaminoglycan chain assembly is not fully understood and because of the in vivo existence of monoglycanated biglycan, mutant core proteins were stably expressed in human 293 and Chinese hamster ovary cells in which i) either one or both serine residues were converted into alanine or threonine residues, ii) the number of acidic amino acids N-terminal of the respective serine residues was altered, and iii) a hexapeptide was inserted between the mutated site 1 and the unaltered site 2. Labeling experiments with [(35)S]sulfate and [(35)S]methionine indicated that serine 42 was almost fully used as the glycosaminoglycan attachment site regardless of whether site 2 was available or not for chain assembly. In contrast, substitution of site 2 was greatly influenced by the presence or absence of serine 42, although additional mutations demonstrated a direct influence of the amino acid sequence between the two sites. When site 2 was not substituted with a glycosaminoglycan chain, there was also no assembly of the linkage region. These results indicate that xylosyltransferase is the rate-limiting enzyme in glycosaminoglycan chain assembly and implicate a cooperative effect on the xylosyl transfer to site 2 by xylosylation of site 1, which probably becomes manifest before the removal of the propeptide. It is shown additionally that biglycan expressed in 293 cells may still contain the propeptide sequence and may carry heparan sulfate chains as well as sulfated N-linked oligosaccharides.

The effect of topical delivery of novel bisacylphosphonates in reducing alveolar bone loss in the rat model.

BACKGROUND: Periodontal surgery stimulates osteoclast activity, leading to varying amounts of alveolar crest loss. We have established that topical application of 20 mg/ml of alendronate placed at the surgical mucoperiosteal site produced a striking reduction of alveolar bone loss in the rat model. The aim of this investigation was to examine the antiresorptive efficacy of 3 novel bisacylphosphonates topically delivered at the surgical site, in comparison to alendronate and etidronate which are in clinical use. METHODS: Mucoperiosteal flap (MF) surgery was performed on the buccal and lingual aspects next to molars on both sides of the rat mandible. A gelatin sponge soaked in the bisphosphonate solution prepared by dissolving 20 mg of the bisphosphonate (alendronate, etidronate, VS-5, VS-6, ISA-13, SuBP) in 1 ml of saline was applied to exposed bone on the right side of the mandible (experimental, MF + BPs ) and the left side was treated with saline only (control, MF + S). Sections were evaluated for bone loss using microradiography pattern and amount. RESULTS: The 3 novel bisacylphosphonates, VS-5 VS-6, and ISA-13 were more effective than etidronate, and less effective than alendronate. The most effective among this group was ISA-13 followed by VS-5 and VS-6. CONCLUSION: We conclude that ISA-13-like alendronate is effective in reducing alveolar bone loss when delivered at surgical sites. Since ISA-13 is well absorbed through mucose tissues, we suggest that ISA-13 efficacy on reducing bone loss should be tested by its application on the mucosal tissue.

A peptide prodrug approach for improving bisphosphonate oral absorption.

This work was aimed at improving the absorption of bisphosphonates by targeting carrier systems in the intestine and the intestinal peptide carrier system (hPEPT1), in particular. (14)C-Labeled pamidronate and alendronate as well as radiolabeled and "cold" peptidyl-bisphosphonates, Pro-[(3)H]Phe-[(14)C]pamidronate, and Pro-[(3)H]Phe-[(14)C]alendronate were synthesized. In situ single-pass perfusion studies revealed competitive inhibition of transport by Pro-Phe, suggesting peptide carrier-mediated transport. Prodrug transport in the Caco-2 cell line was significantly better than that of the parent drugs, and the prodrugs exhibited high affinity to the intestinal tissue. Oral administration of the dipeptidyl prodrugs resulted in a 3-fold increase in drug absorption following oral administration in rats, and the bioavailability of Pro-Phe-alendronate was 3.3 (F(TIBIA)) and 1.9 (F(URINE)) times higher than that of the parent drug. The results indicate that the oral absorption of bisphosphonates can be improved by peptidyl prodrugs via the hPEPT1; however, other transporters may also be involved.

Synthesis and preclinical pharmacology of 2-(2-aminopyrimidinio) ethylidene-1,1-bisphosphonic acid betaine (ISA-13-1)-a novel bisphosphonate.

PURPOSE: To validate our hypothesis that a bisphosphonate (BP) having a nitrogen-containing heterocyclic ring on the side chain, and with no hydroxyl on the geminal carbon would possess increased activity, and better oral bioavailability due to enhanced solubility of its calcium complexes/salts and weaker Ca chelating properties. METHODS: A novel BP, 2-(2-aminopyrimidinio)ethylidene-1, 1-bisphosphonic acid betaine (ISA-13-1) was synthesized. The physicochemical properties and permeability were studied in vitro. The effects on macrophages, bone resorption (young growing rat model), and tumor-induced osteolysis (Walker carcinosarcoma) were studied in comparison to clinically used BPs. RESULTS: The solubility of the Ca salt of ISA-13-1 was higher, and the log beta(Ca:BP) stability constant and the affinity to hydroxyapatite were lower than those of alendronate and pamidronate. ISA-13-1 exhibited effects similar to those of alendronate on bone volume, on bone osteolysis, and on macrophages, following delivery by liposomes. ISA-13-1 was shown to have 1.5-1.7 times better oral absorption than the other BPs with no deleterious effects on the tight junctions of intestinal tissue. CONCLUSIONS: The similar potency to clinically used BPs, the increased oral absorption as well as the lack of effect on tissue tight junction of ISA-13-1 warrant its further consideration as a potential drug for bone diseases.

Disposition of alendronate following local delivery in a rat jaw.

BACKGROUND: Recently, we have shown that local delivery of alendronate reduced significantly bone resorption activated by surgical separation of periosteum from bone. These results advocate the use of local application of alendronate in bone surgeries to prevent regional bone resorption at the surgery site. Here we investigated the efficacy of absorbtion of alendronate by the bone from a gelatin sponge soaked with radiolabeled alendronate applied topically at the surgical site. METHODS: Following elevation of the mucoperiosteal flap next to premolars and molars of the rat mandible, a gelatin sponge soaked with 10 microl of radiolabled alendronate (1 microCi/mg) was applied to exposed bone on one side. The local absorbtion of alendronate and its disposition in the contralateral side of the mandible as well as in the tibia bone were analyzed. RESULTS: The results show that 10% of total alendronate content of the gelatin sponge was absorbed in the bone locally (in the surgical site), while 0.2% was disposed in the tibia. Of interest is the fact that the surgical wound in the contralateral side increased the disposition of alendronate up to 2%. This finding is most likely the result of extravasation and diffusion of alendronate due to surgical wounding. CONCLUSION: This study strongly supports our notion that local delivery of alendronate and its affinity to bone may become a very important treatment modality to prevent resorption of bone during dental and orthopedic procedures.

Transplacental effects of bisphosphonates on fetal skeletal ossification and mineralization in rats.

Bisphosphonates are clinically used mainly to reduce bone resorption. We studied the transplacental effects of two bisphosphonates on the fetal skeleton in rats. Pregnant rats were treated during days 11-20 of pregnancy with daily subcutaneous injections of 0.1 mg/kg of alendronate or a newly synthesized bisphosphonate, VS-b6. This period of pregnancy was chosen because the active development of bones from mesenchyme through cartilaginous models occurs during that time. Histological examination of midlongitudinal sections of the 21-day-old fetuses showed an increase in the amount of diaphyseal bone trabeculae with slight shortening of the diaphysis in the experimental fetuses, in comparison to controls. Computerized histomorphometric studies similarly showed an increase in the amount of diaphyseal bone trabeculae with a concomitant decrease in bone marrow volume, but no change in cartilage volume. In addition, chemical analysis of the fetal bones showed an increase in calcium content in the treated fetuses. 14C-alendronate was shown to pass through the rat placenta and accumulate in the fetuses, most probably in their bones. This is presumed because bisphosphonates are known to accumulate in bone, being stored there for long periods of time. It is important, in light of our results, to give careful consideration to the treatment of women with bisphosphonates at childbearing age, whenever this is needed.

Bisphosphonates and tetracycline: experimental models for their evaluation in calcium-related disorders.

PURPOSE: This work was aimed at synthesizing novel bisphosphonates (BPs) and examining them in comparison to clinically used BPs such as pamidronate and alendronate, and to tetracycline, in order to evaluate their potential as anticalcification and antiresorption agents. The correlation between the various models was examined in order to establish facile experimental models for pre-screening of potential compounds. METHODS: Nitrogen-containing heterocyclic, novel BPs such as 2-(3-methylimidazolio) ethylidene-1,1-bisphosphonic acid betaine (VS-5b), 2-(2-dimethylamino-4-pyrazinio)ethylidene-1,1-bisphosphonic acid betaine (VS-6b), and 2-(2-alpha-pyridylethylthio) ethylidene-1,1-bisphosphonic acid (ISA-225), were synthesized and evaluated in comparison to clinically used BPs, in various experimental models of resorption and calcification. RESULTS: The physicochemical properties of the novel compounds are slightly different than the BPs in clinical use: the pKa values are lower, the affinity for hydroxyapatite is lower and the solubilities of the calcium salts are higher. The anticalcification potencies of the novel compounds were high and ranked as follows: alendronate = pamidronate > VS-6b = VS-5b = ISA-225 > tetracycline. The in vivo antiresorption activity of VS-5b and VS-6b in comparison to that of the clinically employed, pamidronate, was shown to be similar and higher, respectively. CONCLUSIONS: The anticalcification activity of the novel compounds as well as that of tetracycline was lower than that of alendronate. The antiresorption activity of VS-6b was similar to that of pamidronate. A good correlation between the different models was found, enabling the facile screening of novel compounds. The activities of tetracycline and EDTA highlight the distinct behavior of BPs as "crystal poison." In addition, tetracycline was found to be a potent anticalcification agent in the ectopic calcification model.