Radiologic case study. Abrasion chondroplasty mimicking avascular necrosis

Arthroscopic abrasion arthroplasty, subchondral drilling, and microfracture continue to be performed with some frequency in younger patients with focal chondral defects and occasionally for patients with moderate degenerative knee arthritis. The plain radiographic appearance after those procedures may mimic avascular necrosis, but MRI is a sensitive method used to exclude the diagnosis of avascular necrosis and evaluate the extent to which fibrocartilaginous repair tissue has formed. When combined with an appropriate clinical history, dedicated articular cartilage imaging sequences improve the sensitivity and specificity that MRI provides in these patients with chondral knee injuries.     

Association of the G289S single nucleotide polymorphism in the HSD17B3 gene with prostate cancer in Italian men

BACKGROUND: Prostate cancer is a significant public health problem in this country. Substantial data support a plausible role for androgens in the etiology of this disease. The human HSD17B3 gene encodes the testicular (or type III) 17 beta-hydroxysteroid dehydrogenase enzyme, which catalyzes testosterone biosynthesis in men. METHODS: We have investigated the G289S (glycine at codon 289 replaced by serine) polymorphism at the HSD17B3 locus as a candidate single nucleotide polymorphism (SNP) for prostate cancer risk in constitutional DNA from 103 Italian prostate cancer patients and 109 Italian disease-free centenarians to assess the role of this SNP in susceptibility to prostate cancer. RESULTS: The G289S polymorphism confers a significant increase in risk for prostate cancer (odds ratio = 2.5; 95% confidence interval, 1.03-6.07) in our study population. CONCLUSION: Our data are consistent with a plausible role of the G289S SNP in prostate cancer susceptibility. Therefore, the HSD17B3 gene may be a plausible candidate gene for prostate cancer risk.     

Modulation of dendritic release of dopamine by metabotropic glutamate receptors in rat substantia nigra

A superfusion system was used to study the effects of metabotropic glutamate receptor (mGluR) ligands upon the release of [(3)H]dopamine ([(3)H]DA) previously taken up by rat substantia nigra (SN) slices. trans-(+/-)-1-Amino-(1S,3R)-cyclopentane dicarboxylic acid (trans-ACPD; 100 and 600 microM), a group I and II mGluR agonist, evoked the release of [(3)H]DA from nigral slices. This last effect was reduced significantly by (2S,3S,4S)-2-methyl-2-(carboxycyclopropyl)-glycine (MCCG; 300 microM), an antagonist of group II mGluR, or by the addition of tetrodotoxin (D-APV; 1 microM) to the superfusion medium. D-(-)-2-Amino-5-phosphono-valeric acid (100 microM), an N-methyl-D-aspartate receptor antagonist, or the presence of Mg(2+) (1.2mM) in the superfusion medium did not modify trans-ACPD-induced [(3)H]DA release. In addition, a group II mGluR agonist such as (2S,1'R,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)-glycine (DCG-IV; 100 microM) significantly induced the release of [(3)H]DA from nigral slices, whereas a group I mGluR agonist such as (RS)-3,5-dihydroxyphenylglycine (DHPG; 50 and 100 microM) did not modify the release of the [(3)H]-amine. Further experiments showed that the NMDA (100 microM)-evoked release of [(3)H]DA was decreased significantly by prior exposure of SN slices to trans-ACPD. Finally, partial denervation of the DA nigro-striatal pathway with 6-hydroxydopamine (6-OH-DA) increased trans-ACPD-induced release of [(3)H]DA, whereas it decreased trans-ACPD inhibitory effects on NMDA-evoked release of [(3)H]DA from nigral slices. The present results suggest that the dendritic release of DA in the SN is regulated by mGluR activation. Such nigral mGluR activation may produce opposite effects upon basal and NMDA-evoked release of DA in the SN. In addition, such mGluR-induced effects in the SN are modified in response to partial denervation of the DA nigro-striatal pathway.     

Long-term antidepressant treatment

Major depressive disorder (MDD) is a common and costly illness. Recent research suggests that MDD is a lifelong condition for many patients. This has stimulated researchers to identify risk factors associated with an increased frequency of relapse and recurrence of major depression. One of the most important of these risk factors is an incomplete response to acute treatment. These data have led investigators to pursue techniques that enhance the acute response of patients to therapy, and study whether long-term treatment with antidepressants may prevent relapse and recurrence of MDD. Data from these trials suggest that continuation and maintenance treatment of MDD confers some protection against deteriorating back into an episode after acute treatment and against developing another episode of MDD.     

Learning outcomes in health care ethics; a case study concerning one course

Medicine, Health Care and Philosophy -     

Four new flavonol glycosides from the leaves of Astragalus caprinus

Four new flavonol 3-O-glycosides were isolated from the leaves of Astragalus caprinus. Their structures were elucidated by spectroscopic methods as rhamnocitrin-3-O-[3-hydroxy-3-methylglutaroyl(1-->6)][beta-D-apiofuranosyl(1-->2)]-beta-D-galactopyranoside (1), rhamnetin-3-O-[3-hydroxy-3-methylglutaroyl(1-->6)][beta-D-apiofuranosyl(1-->2)]-beta-D-galactopyranoside (2), kaempferol-3-O-[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)]-beta-D-galactopyranoside (3), and quercetin-3-O-[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][beta-D-apiofuranosyl(1-->2)]-beta-D-galactopyranoside (4).     

Ultrastructural analysis of bone tissue irradiated by Er:YAG Laser

BACKGROUND AND OBJECTIVES: The use of erbium:yttrium aluminum garnet (Er:YAG) laser has been suggested for bone ablation, however, little is known about the nature of the tissue after irradiation. This study was aimed to analyze the ultrastructure of bone tissue treated with Er:YAG laser, as compared to those treated with CO(2) laser and bur drilling. STUDY DESIGN/MATERIALS AND METHODS: Parietal bones of Wistar rats were treated and analyzed by light microscopy, transmission electron microscopy (TEM), electron diffraction analysis and energy dispersive X-ray spectroscopy (SEM-EDX). RESULTS: This study demonstrated that Er:YAG laser irradiation resulted in a very thin changed layer of approximately 30 microm thickness, which consisted of two distinct sub-layers: a superficial, greatly altered layer and a deep, less affected layer. CONCLUSIONS: The major changes found on bone surface after Er:YAG laser irradiation consisted of micro-cracking, disorganization, and slight recrystallization of the original apatites and reduction of surrounding organic matrix.     

Micellar-type complexes of tailor-made synthetic block copolymers containing the HIV-1 tat DNA for vaccine application

A novel class of cationic block copolymers constituted by a neutral hydrophilic poly(ethylene glycol) (PEG) block and a positively charged poly(dimethylamino)ethyl methacrylate block was prepared for delivery of DNA. These block copolymers spontaneously assemble with DNA to give in aqueous medium micellar-like structures. Five of these novel block copolymers (K1-5), differing in the length of both the PEG chain and the linear charge density of the poly(dimethylamino)ethyl methacrylate block, were prepared and analyzed for gene delivery, gene expression and safety. All five block copolymers protected DNA from DNAse I digestion and delivered the DNA into the cell. However, only three of them (K1, K2 and K5) released the DNA at level allowing efficient gene expression into cells. No toxic effects of both the copolymers alone or their DNA complexes were observed in vitro or in mice. In addition, copolymers were scarcely immunogenic. These results indicate that this novel class of cationic block copolymers is safe and possesses the biological characteristics required for DNA delivery, thus, representing promising vehicles for DNA vaccination.     

Involvement of the endocannabinoid system in the ability of long-term tricyclic antidepressant treatment to suppress stress-induced activation of the hypothalamic-pituitary-adrenal axis.

The efficacy of antidepressants has been linked in part to their ability to reduce activity of the hypothalamic-pituitary-adrenal (HPA) axis; however, the mechanism by which antidepressants regulate the HPA axis is largely unknown. Given that recent research has demonstrated that endocannabinoids can regulate the HPA axis and exhibit antidepressant potential, we examined the hypothesis that the endocannabinoid system is regulated by long-term antidepressant treatment. Three-week administration of the tricyclic antidepressant desipramine (10 mg/kg/day) resulted in a significant increase in the density of the cannabinoid CB(1) receptor in the hippocampus and hypothalamus, without significantly altering endocannabinoid content in any brain structure examined. Furthermore, chronic desipramine treatment resulted in a reduction in both secretion of corticosterone and the induction of the immediate early gene c-fos in the medial dorsal parvocellular region of the paraventricular nucleus of the hypothalamus (PVN) following a 5 min exposure to swim stress. Acute treatment with the CB(1) receptor antagonist, AM251 (1 mg/kg), before exposure to swim stress, completely occluded the ability of desipramine to reduce both corticosterone secretion and induction of c-fos expression in the PVN. Collectively, these data demonstrate that CB(1) receptor density in the hippocampus and hypothalamus is increased by chronic tricyclic antidepressant treatment, and suggest that this upregulation could contribute to the ability of tricyclic antidepressants to suppress stress-induced activation of the HPA axis.