New synthesis of tic-hydantoins sigma-1 ligands and pharmacological evaluation on cocaine-induced stimulant effects.

Activation of the newly identified σ1 chaperone protein is involved in several aspects of the psychostimulant and addictive effects of cocaine. The development of ligands that selectively target the σ1 protein may lead to putative potent anti-cocaine agents. We report here a new and more convergent synthetic pathway to amino side chain substituted hydantoins. Twenty new analogs of our lead compound were synthesized. None of them showed better in vitro affinity for σ1 receptor than our lead compound. Nevertheless, three of them, obtained as racemates, showed high in vitro affinity and selectivity for σ1 receptor. A preliminary in vivo evaluation of their pharmacological activity identified compound 22 as one that increases cocaine-induced locomotor stimulation and therefore acts as a potential efficient σ1 agonist.

Understanding the benefits and costs of communities of practice

It argues that promoting healthy collaboration in communities of practice takes management support at all levels, and that management wants and needs to comprehend what the organization gets for that investment. Document in pdf format; Acrobat Reader required.

Parallel synthesis and anti-malarial activity of a sulfonamide library.

Solution-phase synthesis and evaluation of a library of 31 sulfonamides as inhibitors of a chloroquine-resistant strain of Plasmodium falciparum are described. The most potent compound displayed an activity 100-fold better than chloroquine. Experiments using a fluorescent sulfonamide derivative suggest that their site of action inside the parasite is different to that of chloroquine.

Synthesis and in vitro and in vivo antimalarial activity of new 4-anilinoquinolines.

A new series of 4-anilinoquinolines with two proton-accepting side chains has been synthesized. Antimalarial activity and levels of cytotoxicity upon both MRC-5 cells and macrophages were found to be highly dependent upon the features of these side chains. Several compounds were found to be active in the low nanomolar range, against both chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. From among them, a morpholino derivative cured mice infected by Plasmodium berghei and displayed a lower toxicity than amodiaquine upon mouse macrophages.

Antimalarial in-vivo activity of bis(9-amino-6-chloro-2-methoxyacridines).

In the fight against malaria, chemotherapy using bisacridines may represent an alternative method to overcoming chloroquine-resistance. Eight bis(9-amino-6-chloro-2-methoxyacridines), in which acridine moieties were linked by polyamines substituted with a side chain, were tested for their in-vivo activity upon mice infected by Plasmodium berghei. Three of the compounds revealed antimalarial activity but no relationship could be deduced from a comparison of in-vitro and in-vivo activities. N-alkylation of the central amino group generated toxicity and, therefore, only compounds N-acylated in this position can be selected as leads.

Fracture and bone mineral density in hemodialysis patients.

AIM: The aim of this cross-sectional study was to determine in hemodialysis patients the pattern of low trauma fracture, the ability of dual X-ray absorptiometry (DXA) to discriminate between patients with and without fracture, and the magnitude, distribution and mechanism of bone loss. PATIENTS AND METHODS: Eighty-eight patients were studied. Bone mineral density (BMD) was measured by DXA at lumbar spine (LS), femoral neck (FN) and 3 radius sites (UD, MID and 1/3R). In 11 patients (12.5%), 16 fractures occurred and were predominant at the distal forearm and ribs. RESULTS: Patients with fracture had a significatively lower BMD Z-score at LS (-1.34 +/- 1.66 vs -0.42 +/- 1.23), at FN (-1.58 +/- 1.25 vs -0.60 +/- 1.01), at MID radius (-2.59 +/- 1.34 vs -0.93 +/- 1.76) and 1/3 radius (-1.62 +/- 1.60 vs -0.39 +/- 1.32). They also had a longer history of dialysis (113 +/- 64 vs 53 +/- 65 months). Prevalence of osteoporosis varied from 23% at LS to 50% at MID radius. CONCLUSION: Multiple regression analysis showed that there was no influence of gender, age, parathormone status and primary renal disease on BMD. However, at FN, UD, MID and 1/3 radius, a significantly negative correlation was found between length of dialysis and BMD Z-score. By contrast at LS, there was a positive correlation between age at onset of dialysis and BMD Z-score. Despite occurrence of fracture at the fistula forearm, BMD levels were similar in both arms.

Effect of exogenous and endogenous antioxidants on 3-nitropionic acid-induced in vivo oxidative stress and striatal lesions: insights into Huntington's disease.

3-Nitropropionic acid (3-NP) is an irreversible inhibitor of complex II in the mitochondria. 3-NP toxicity has gained acceptance as an animal model of Huntington's disease (HD). In the present study, we confirmed that rats injected with 3-NP (20 mg/kg, i.p., daily for 4 days) exhibit increased oxidative stress in both striatum and cortical synaptosomes as well as lesions in the striatum. Synaptosomal membrane proteins from rats injected with 3-NP exhibited a decrease in W/S ratio, the relevant electron paramagnetic resonance (EPR) parameter used to determine levels of protein oxidation, and western blot analysis for protein carbonyls revealed direct evidence of increased synaptosomal protein oxidation. Treatment of rats with the brain-accessible free radical spin trap 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO; 30 mg/kg, i.p., daily 2 h before 3-NP injection) or with N-acetylcysteine (NAC; 100 mg/kg, i.p., daily 2 h before 3-NP injection), a known glutathione precursor, before 3-NP treatments protects against oxidative damage induced by 3-NP as measured by EPR and western blot analysis for protein carbonyls. Furthermore, both DEMPMPO and NAC treatments before 3-NP administration significantly reduce striatal lesion volumes. These data suggest oxidative damage is a prerequisite for striatal lesion formation and that antioxidant treatment may be a useful therapeutic strategy against 3-NP neurotoxicity and perhaps against HD as well.

3-nitropropionic acid induced in vivo protein oxidation in striatal and cortical synaptosomes: insights into Huntington's disease.

3-nitropropionic acid (3-NP) administered systemically daily for 4 days to rats inhibits mitochondrial oxidative phosphorylation and induces selective lesions in the striatum in a manner reminiscent of Huntington's disease (HD). To investigate the potential oxidative nature of these lesions, rats were injected with 3-NP (20 mg/kg, i.p. daily for 4 days) and subsequently isolated brain synaptosomal membranes were examined for evidence of oxidative stress. Brain synaptosomal membrane proteins from rats injected with 3-NP exhibited a decreased in W/S ratio, the relevant electron paramagnetic resonance (EPR) parameter used to determine levels of protein oxidation (76% of control), and Western blot analysis for protein carbonyls revealed direct evidence of increased synaptosomal membrane protein oxidation (248% of control). Similar results were obtained in synaptosomes isolated from striatum and from cerebral cortex, demonstrating that the oxidative changes are not restricted to the lesion site. Moreover, increased oxidative stress was evident prior to the appearance of morphological lesions. These data are consistent with the hypothesis that 3-NP-induced striatal lesions, and perhaps those in HD, are associated with oxidative processes.

Detection of human papillomaviruses in paraffin-embedded biopsies of cervical intraepithelial lesions: analysis by immunohistochemistry, in situ hybridization, and the polymerase chain reaction.

One hundred and forty biopsies with an initial diagnosis of cervical intraepithelial lesion (CIL) were tested for the presence of human papillomavirus (HPV) by immunohistochemistry and in situ hybridization using commercial biotinylated probes (Vira-Type in situ assay; Digene Diagnostics, Silver Spring, MD) or probes labeled with digoxigenin by the random primer technique. Immunohistochemistry was more inferior to the in situ hybridization method, with a detection rate of 14% (20/140) compared to 61% (86/140) for the in situ assay with the digoxigenin-labeled probes. Biotinylated probes proved to be slightly less sensitive than digoxigenin-labeled probes, with a detection rate of 53% (74/140). Although less sensitive in our series taken as a whole, immunohistochemistry was positive in a few cases of CILs negative by in situ hybridization, so that the association of these techniques gave the highest detection rate (66%; 92/140). The CILs that remained negative with these methods (34%; 48/140) were investigated by the polymerase chain reaction (PCR) using consensus primers to determine definitively the presence of HPV in these lesions and were reviewed histologically to assess the diagnosis of CILs. The PCR method increased the detection rate of HPV in our series to 76% (107/140). The diagnosis of CILs was confirmed for all the biopsy specimens positive by PCR (15/15; 100%) and for all the HPV negative tissues with histological features of a high-grade lesions (7/7; 100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Electric fields modulate bone cell function in a density-dependent manner.

The influence of an extremely low frequency (ELF) electric field stimulus (30 Hz at 6 microV/cm rms), known to promote bone formation in vivo, was evaluated for its ability to affect bone cell function in vitro. To accomplish this, we developed an apparatus for the exposure of monolayer cell systems to electric fields in a manner that provides relatively uniform electric field exposure of multiple cell samples as well as a rigorous sham exposure. We show that field exposure significantly limits the normal increase in osteoblastic cell number and enhances alkaline phosphatase activity compared to sham-exposed samples. Moreover, these alterations are shown to occur in a cell density-dependent manner. Samples plated at 6 x 10(3) cells/cm2 show no effect of field exposure. In samples plated at 30 x 10(3) cells/cm2, 72 h of field exposure resulted in 25% fewer cells in the exposed samples, and a doubling of alkaline phosphatase activity in those cells compared to sham exposure. Experiments using a 12 h exposure to preclude significant changes in cell number during the exposure show this density-dependent response to be biphasic. Sparse cultures (< 50 x 10(3) cells/cm2) were not found to be affected by the field exposure, but increases in alkaline phosphatase activity occurred in cultures at densities of 50-200 x 10(3) and 200-350 x 10(3) cells/cm2 and no effect on alkaline phosphatase activity was seen in confluent cell cultures of greater than 350 x 10(3) cells/cm2.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of bone marrow sections, smears and immunohistological staining for immunoglobulin light chains in the diagnosis of benign and malignant plasma cell proliferations.

Bone marrow specimens from 118 patients with clinical suspicion of multiple myeloma were studied to assess the diagnostic reliability of histological and cytological criteria. Plasma cell clonality was assessed by demonstrating light chain restriction. In most cases of multiple myeloma, the classical cytological and histological criteria were found. In eight cases in which the marrow contained less than 10% of plasma cells, there was discordance between the light microscopic and immunohistochemical findings. In six cases without evidence of multiple myeloma and with polyclonal plasma cells in bone marrow, abnormal plasma cells resembling a malignant proliferation were found. These findings indicate that comparison of histological and cytological results with immunohistological studies for immunoglobulin light chains in bone marrow biopsy sections can be helpful in the evaluation of patients with a suspicion of multiple myeloma and when the marrow contains less than 10% of plasma cells.

Influence of estrogen replacement therapy on endogenous calcitonin production rates.

Calcitonin is now a well-accepted therapy for inhibition of bone loss, both in the first years of menopause and in established osteoporosis. However, its exact role in the pathogenesis of that disease as well as the interactions between calcitonin production and estrogen metabolism remain unsolved. In order to clarify the influence of estrogen replacement therapy (ERT) on calcitonin secretory capacity, we measured whole plasma immunoreactive calcitonin basal levels, metabolic clearance rates and production rates in a group of postmenopausal women, before and after a daily intake for 28 days of 0.625 mg/day of conjugated equine estrogens, and again 4 weeks after the withdrawal of that estrogen replacement therapy. No significant changes appeared in immunoreactive calcitonin or immunoreactive calcitonin metabolic clearance rate but the production rate significantly increased over the 28 days (mean +/- SEM, from 21.3 +/- 5.1 pg/ml to 25.2 +/- 5.9 pg/ml, p less than 0.05), and then decreased 4 weeks after therapy was withdrawn to the initial level (17.9 +/- 3.6 pg/ml). We concluded that estrogen replacement therapy significantly increases calcitonin secretory capacity. This confirms the interactions between calcitonin production and estrogen metabolism, and may provide an explanation concerning the mode of action of estrogen replacement therapy in prevention of postmenopausal bone loss.

Calcitonin and postmenopausal bone loss.

In order to establish the role of calcitonin (CT) in postmenopausal bone loss, we studied CT metabolism in 25 pre- and postmenopausal women. Postmenopausal women presented a highly significant reduction of CT basal levels compared to premenopausal females (p less than 0.01). Also, production rates of CT in osteoporotics were significantly lower than in either young premenopausal (18-25 years old), older premenopausal (35-40 years old), or postmenopausal healthy subjects. In a study in rabbits, we found that injection of CT, along with equimolar amounts of anti-SCT antibodies extracted from serum of pagetic patients, did not inhibit the hypocalcemic response to the hormone, thus demonstrating that resistance to CT treatment cannot be accounted for by antibody production. In a subsequent clinical study in patients with Paget's disease of bone, we found that 200 IU/day of salmon CT (SCT), given by nasal spray, improved both clinically and biochemically the activity of the disease, as demonstrated by 37 +/- 4% decrease of serum alkaline phosphatase and 35 +/- 5% fall of urinary excretion of hydroxyproline after six months of therapy. The effectiveness of CT as nasal spray was further tested in healthy women at an early stage of menopause. A 12-month course of intranasal SCT counteracted early postmenopausal bone loss, presumably by inhibiting bone resorption. In conclusion, intranasal CT seems to be a very attractive alternative to be considered for the prevention of postmenopausal osteoporosis.

Effects of repetitive administration of growth hormone-releasing hormone on growth hormone secretion, insulin-like growth factor I, and bone metabolism in postmenopausal women.

This study sought to determine whether GH response to synthetic GHRH was impaired in 13 postmenopausal (55-71 years) as compared with that in 8 eugonadal women and whether IGF-I and bone metabolism were consequently depressed. Thereafter, the effects of daily iv injections of 80-micrograms GHRH-44 for 8 days were studied in the same postmenopausal group. In addition to significantly higher basal IGF-I and osteocalcin levels (P less than 0.005) in eugonadal as compared with the postmenopausal women, the administration of one GHRH-44 injection resulted in significantly higher 120-min postinjection GH maximum peak and cumulative responses in the former group as well (P less than 0.005). Highly significant correlations were observed between 17 beta-estradiol plasma levels and either GH maximum peak or cumulative responses to GHRH-44 when both groups were pooled together, but not when considered independently. In postmenopausal women, a correlation was found between both age and duration of menopause and GH responses. Repeated GHRH-44 injections in postmenopausal women induced a significant increase in GH response (P less than 0.001) as well as in IGF-I levels from day 4 to 8. No phospho-calcium parameters were modified except for a significant rise in osteocalcin from day 2 to 8. These data indicate an age-related loss of sensitivity of somatotrope cells to GHRH-44 in postmenopausal women, partly corrected by repeated daily GHRH-44 injections. As a consequence of the GHRH-induced increase in GH secretion, IGF-I was also enhanced and may be responsible for a stimulatory effect on bone formation, as shown by the osteocalcin increase, uncoupled from bone resorption.

Biological and clinical assessment of a new bisphosphonate, (chloro-4 phenyl) thiomethylene bisphosphonate, in the treatment of Paget's disease of bone.

Several Biophosphonates have been used as therapeutic agents for Paget's bone disease. (Chloro-4 phenyl)thiomethylene-bisphosphonate (CIPsMBP) has recently been shown to have significant antiosteoclastic activity while an affect of CIPsMBP on mineralization was only observed at high doses. We tested this drug for 6 months in 23 pagetic patients distributed in three groups. Gr 1 (n = 5) receiving 200 mg/day showed a decrease of serum alkaline phosphatase (SAP) to 42 +/- 4% (p less than 0.01) of initial value (100%) while hydroxyprolinuria/creatinuria ratio (OH/Cr) dropped to 69 +/- 8% of baseline. In 4 patients receiving 400 mg/day, SAP improved to 48 +/- 9% of initial value (p less than 0.01) and OH/Cr to 40 +/- 3% (p less than 0.01). In the last group (n = 14) receiving 200 mg/day for 3 months, and 400 mg/day thereafter up to the 6th month SAP decreased to 53 +/- 4% and OH/Cr to 62 +/- 6% of initial value (p less than 0.01). Clinical improvement was significant from the first month of treatment. No resistance (mean decrease of SAP lower than 30%) was recorded and no radiological or clinical evidence of mineralization defect appeared. The clinical and biological tolerance was excellent throughout the study.

1-Year controlled randomised trial of prevention of early postmenopausal bone loss by intranasal calcitonin.

79 women who had been menopausal for less than 36 months and who had not received any form of treatment to prevent bone loss were randomly assigned to a 12-month regimen of calcium 500 mg/day or calcium 500 mg plus intranasal salmon calcitonin 50 IU/day for 5 days per week. After 12 months of treatment bone mineral density had decreased in the calcium-only group by a mean of 3.16 (SEM 0.6)% (p less than 0.01) but had increased in the calcium plus calcitonin group by 1.38 (0.8)% (NS). The difference in response between the two treatment groups was also highly significant (p less than 0.01), as was the difference between values for hydroxyprolinuria/creatininuria (p less than 0.01). Endogenous calcitonin levels rose significantly in the calcium group but remained unchanged in calcitonin-treated patients. Treatment by calcitonin and calcium was not followed by increased secretion of parathyroid hormone. The findings suggest that intranasal calcitonin can counteract early postmenopausal bone loss.