Venous ligation-mediated bone adaptation is NOS 3 dependent

Interstitial fluid flow (IFF) in bone has been hypothesized to mediate bone modeling in the absence of mechanical strain. The mechanism of this effect has not been clearly defined, though previous studies indicate that nitric oxide (NO) may play an important role in mediating IFF. In the current study, mice with a targeted disruption of the NOS 3 gene were used according to a previously established model of altered interstitial fluid flow in bone. Femoral vein ligation was performed in one limb to increase intramedullary pressure and consequently its IFF; a sham operation was performed on the contralateral limb. The mice were then hindlimb suspended to uncouple the effects of altered flow in the limb from mechanical loading. Differences in radiographic bone density and bone strength were compared for the sham and venous-ligated femurs in wild-type (WT) mice and NOS 3 knockout (KO) mice. Suspension-induced bone loss in the femurs, as evidenced by a loss in radiographic bone mineral density (BMD), was seen in both groups. Differences between sham and venous-ligated femurs were significant only for the WT mice, in which there appeared to be a protective effect of venous ligation against bone loss [-6.69% (ligated) vs. -12.36% (sham), P<0.05]. Furthermore, the difference in bone density between sham and venous-ligated femurs was muted by NOS 3 knockout, suggesting that the protective effect of venous ligation against bone loss observed in the WT group was NO dependent. The differences in relative BMD were mirrored in the mechanical testing experiments, where maximum load to fracture was significantly higher in the venous-ligated limbs relative to the sham limbs of the WT mice, but not in the NOS 3 group. Taken together, these data further support the hypothesis that fluid flow can modulate bone modeling and suggest that IFF-mediated bone adaptation is NOS 3 dependent.

CAR/PXR provide directives for Cyp3a41 gene regulation differently from Cyp3a11

This study reports that Cyp3a41 gene contains 13 exons and is localized on the chromosome 5. CYP3A41 is a female-specific isoform that is predominantly expressed in the liver. Estrogen signaling is not responsible for its female specificity. CYP3A41 expression in kidney and brain is observed only in 50% of mice examined. PXR mediates dexamethasone-dependent suppression of CYP3A41. In contrast to CYP3A11, CYP3A41 expression is not induced by pregnenolone-16alpha-carbonitrile (PCN) in wild-type mice, but is significantly suppressed by PCN in PXR(-/-) mice. Phenobarbital and TCPOBOP induce CYP3A11 expression only in the presence of CAR, but have no effect on CYP3A41 expression. Immunoblot and erythromycin demethylase activity analysis reveal robust CYP3A induction after PCN treatment, which is poorly correlated to CYP3A41. These findings suggest a differential role for CAR/PXR in regulating individual CYP3A isoforms by previously characterized CYP3A inducers.

Management of fetal pain during invasive fetal procedures. A review

In recent years, fetal stress and analgesia draw more and more attention. Evidence that fetuses show a significant endocrinological and hemodynamical response to invasive stimuli, and that these responses can be blocked by analgesia, suggests that fetuses experience a stress response, even if this does not signify they experience "pain". Moreover, it is becoming increasingly clear that experiences of pain of a fetus will be "remembered" by the developing nervous system, perhaps for the entire life of the individual, which can probably lead to abnormal behavioural patterns or altered nociception. But up to now, the entire mechanism of fetal stress response and the optimal analgesic drug, dose and route of administration is not so clear.

A rapid multiparameter approach to study factors that regulate osteoclastogenesis: demonstration of the combinatorial dominant effects of TNF-alpha and TGF-ss in RANKL-mediated osteoclastogenesis

Macrophages differentiate into osteoclasts in response to the critical cytokine RANKL. However, the efficiency of RANKL-mediated osteoclastogenesis can be profoundly influenced by various cytokines. While studies describing the isolated effects of particular cytokines on osteoclastogenesis have been performed, combinatorial effects of cytokines have not been addressed routinely due to the absence of an efficient assay system. To study the effects of cytokine combinations on osteoclast formation, we performed in vitro assays using either the RAW293 cell line or primary murine splenic macrophages as osteoclast precursors. Using a multiparameter cytokine plating method, we analyzed osteoclastogenesis in response to multiple combinations of the following inflammation-related cytokines: RANKL, IFN-gamma, TNF-alpha, IL-1beta, IL-6, IL-10. We further investigated the role of T-cell-related cytokine combinations on osteoclastogenesis by measuring osteoclast area in response to RANKL with IFN-gamma, IL-2, IL-4, IL-6, TGF-ss, and TNF-alpha. Treatments with RANKL, TNF-alpha, and TGF-ss induced maximal osteoclast formation, suggesting a role for these cytokines in the most aggressive forms of inflammatory bone loss. TNF-alpha alone, however, was unable to induce osteoclast formation in the absence of RANKL despite co-administration of other proinflammatory cytokines. IFN-gamma was a potent inhibitor under all conditions, implicating T cells and NK cells in osteoclast inhibition. These studies demonstrate a rapid screening approach for identifying the potential collective effects of multiple factors on osteoclastic bone resorption.

Shoot production per responsive leaf explant increases exponentially with explant organogenic potential in Nicotiana species

As part of the effort to develop optimal plant varieties for the production and molecular farming of plant-made pharmaceuticals, this study evaluated shoot organogenic potential of a total of 115 Nicotiana accessions, representing 53 species. To induce shoots, leaves from seedling grown in vitro were cut into pieces, cultured on shoot-induction medium under low light for 3 weeks, and then subcultured onto the same medium for another 4 weeks under normal light. Statistical analysis detected significant differences among the 115 accessions for the percentage of leaf explants producing shoots and the number of shoots produced per responsive leaf explant. Importantly, regression analysis also found an exponential relationship between the number of shoots produced per responsive leaf explant and the percentage of leaf explants producing shoots. The number of shoots produced per responsive leaf explant increased rather slowly, ranging from zero to around five, as the percentage of leaf explants producing shoots increased from 0 to 80%, but the increase became dramatic as the percentage increased from 80% to 100%, reaching as high as 35 shoots per responsive leaf explant. This exponential relationship is the first of its kind to be established in plant regeneration studies using either organogenesis or somatic embryogenesis systems. A possible mechanism that governs the establishment of the exponential relationship is discussed.

Platelet chimerism by polymerase chain reaction (PCR) utilizing variable number of tandem repeats (VNTR) in allogeneic stem cell transplant in children: a new novel approach to full chimerism analysis

Evaluation of chimerism following allogeneic transplantation has been performed traditionally focusing on two cellular compartments, namely lymphoid and myeloid. However, none has been described so far to evaluate platelet chimerism. In order to achieve full chimerism in all three cellular compartments, we prospectively obtained 138 samples of peripheral blood in 55 patients at different post transplant periods following allogeneic hematopoietic transplantation. Evaluation of chimerism was performed utilizing tests of variable number of tandem repeat (VNTR) and sex determination by quantitative polymerase chain reaction (PCR). Tests for platelet chimerism using platelet-rich plasma were simultaneously analyzed with samples for T-cell lymphoid and myeloid compartments. Complete donor chimerism was noted in 49 of 55 patients (89%), while the remaining six have split chimerism ranging from 34 to 98%. There is significant difference (P=0.0004) between the percentages of donor DNA in all three cellular compartments comparing the means+/-s.e.m. (myeloid 95.60+/-0.9, T-cell lymphocytes 87.6+/-1.9, and the platelets 90.8+/-1.5); however, comparison between the medians is not statistically significant. This study represents an additional step towards achieving full chimerism and the observation may help reduce the number of unnecessary platelet transfusions once chimerism is noted in that cellular compartment.

Lowering anti-dsDNA antibodies--what's new?

Antibodies to dsDNA are specific to SLE and are pathogenic, both due to their ability to deposit in tissues through a variety of mechanisms, and to their ability, when present in immune complexes, to activate inflammatory cells. The relationship of serum anti-dsDNA antibody levels to disease activity is a complex one and the factors that determine whether or not such antibodies will be pathogenic in an individual SLE patient are incompletely understood. Although anti-dsDNA antibodies can be made by naïve B cells and B cells belonging to the B1 and marginal zone subsets, pathogenic anti-dsDNA antibodies have the hallmarks of germinal center development and exposure to T cell help, including accumulation of somatic mutations and class switching to the IgG isotype. Epitope spreading may result in aquisition of cross-reactivities with multiple target organ antigens and aquisition of a memory phenotype will allow these B cells to acquire antigen presentation functions that amplify the autoreactive response. In the early stages of disease, or after remission induction protocols, autoreactive B cells may be susceptible to treatments that target T cell costimulation or that deplete or tolerize naïve and mature B cells. Therapeutic approaches targeting innate immune responses or regulatory T cells are starting to be tested in pre-clinical models. In later disease stages, memory and plasma cell accumulation may render patients more resistant to this type of therapeutic approach. Deposition of anti-dsDNA antibodies in target tissues can stimulate an inflammatory cascade that leads to tissue damage. A number of murine models have now been developed that show that interruption of this cascade can prevent or reverse such damage. This type of approach may be beneficial for individuals with established disease. As we learn more about the specific defects that cause SLE, it may become possible to individualize therapy based on patient specific biologic markers.

Cognitive performance and MR markers of cerebral injury in cognitively impaired MS patients

OBJECTIVE

To relate neuropsychological performance to measures of cerebral injury in persons with MS selected for cognitive impairment.

METHODS

Participants were 37 individuals with relapsing-remitting (59.5%) and secondary progressive (40.5%) MS. They were tested at baseline as part of a clinical trial to enhance cognition with an acetylcholinesterase inhibitor. Eligibility criteria included at least mild cognitive impairment on a verbal learning and memory task. A modified Brief Repeatable Battery of Neuropsychological Tests formed the core of the behavioral protocol. Neuroimaging measures were central (ventricular) cerebral atrophy, lesion volume, and ratios of N-acetyl aspartate (NAA) to both creatine and choline.

RESULTS

A clear, consistent relation was found between cognitive and MR measures. Among neuroimaging measures, central atrophy displayed the highest correlations with cognition, accounting for approximately half the variance in overall cognitive performance. NAA ratios in right hemisphere sites displayed larger correlations than those on the left. Multiple regression models combining the MR measures accounted for well over half the variance in overall cognitive performance. The Symbol Digit Modalities Test was the neuropsychological task most strongly associated with the neuroimaging variables.

CONCLUSIONS

If a strong and stable association can be firmly established between cognitive and MR variables in appropriate subsets of MS patients, it might aid in the investigation of interventions to enhance cognition and modify the course of the disease.

C-fiber modulation of the rat type I slowly adapting mechanoreceptor

Effects of C-fiber activation on type I slowly adapting mechanoreceptor responses were investigated in a rat in vitro nerve-skin preparation using controlled mechanical stimuli. Two changes in behavior were evoked by antidromic C-fiber stimulation: (1). The type I response to mechanical stimuli was modulated in a graded fashion by antidromic C-fiber activation. The average decrease in mechanoresponse from baseline discharge was 53% at 20-Hz, 51% at 5-Hz, and 30% at 1-Hz stimulation rate. The type I response recovered to baseline levels following termination of antidromic electrical stimulation. (2). Antidromic C-fiber activation generated a spontaneous ongoing activity in many skin units; this was independent of mechanical stimulation and outlasted electrical stimulation. The fact that neither antidromic electrical stimulation of the crushed nerve trunk nor selective A-fiber activation elicited these reactions suggests that they were mediated via action potentials of slowly conducting (C-fiber) axons. Immunohistochemical staining revealed both substance P- and calcitonin gene-related peptide-like immunoreactivity in small unmyelinated nerve fibers entering the touch dome. These results support the concepts that (1). the type I slowly adapting mechanoreceptor in rat receives input from nociceptive terminals within the touch dome. (2). The function of type I slowly adapting mechanoreceptors is modulated by axon reflex activation of nociceptor terminals, which may play a role in altering the type I response during states of mechanical allodynia and have paracrine and autocrine influences on maintenance of touch dome structure.

Atrial natriuretic peptide stimulates cat carotid body chemoreceptors in vivo

It is known that atrial natriuretic peptide (ANP) is released from cardiac myocyte and other stores during hypoxia and is involved in pulmonary-cardiovascular reflexes and in natriuresis and diuresis. Since the carotid body initiates hypoxic chemoreflexes, we hypothesized that ANP could potentiate the hypoxic stimulation of the carotid body chemoreceptor in vivo. We studied the effect of close intra-arterial injection of ANP on carotid chemoreceptor activity in anesthetized male cats which were paralyzed and artificially ventilated. Graded doses of ANP (0-10 nmoles) were administered by intra-arterial injections and they produced an excitatory response. Single dose of ANP (6.5 nmoles) at four steady-state levels of arterial PO(2), at constant PCO(2), produced increases of chemoreceptor activity. This increase of chemoreceptor activity with ANP in the presence of CO(2)-HCO(3)(-) in vitro could make a difference from those without CO(2)-HCO(3)(-) in vivo.

Spectroscopic studies of interaction of chlorobenzylidine with DNA

Electronic absorbance and fluorescence titrations are used to probe the interaction of chlorobenzylidine with DNA. The binding of chlorobenzylidine to DNA results in hypochromism, a small shift to a longer wavelength in the absorption spectra, and emission quenching in the fluorescence spectra. These spectral characteristics suggest that chlorobenzylidine binds to DNA by an intercalative mode. This conclusion is reinforced by fluorescence polarization measurements. Scatchard plots constructed from fluorescence titration data give a binding constant of 1.3 x 10(5) M(-1) and a binding site size of 10 base pairs. This indicates that chlorobenzylidine has a high affinity with DNA. The intercalative interaction is exothermic with a Van't Hoff enthalpy of -143 kJ/mol. This result is obtained from the temperature dependence of the binding constant. The interaction of chlorobenzylidine with DNA is affected by the pH value of the solution. The binding constant has its maximum at pH 3.0. Upon binding to DNA, the fluorescence from chlorobenzylidine is quenched efficiently by the DNA bases and the fluorescence intensity tends to be constant at high concentrations of DNA when the binding is saturated. The Stern-Volmer quenching constant obtained from the linear quenching plot is 1.6 x 10(4) M(-1) at 25 degrees C. The measurements of the fluorescence lifetime and the dependence of the quenching constant on the temperature indicate that the fluorescence quenching process is static. The fluorescence lifetime of chlorobenzylidine is 1.9 +/- 0.4 ns.

Analysis of a CD40 ligand dinucleotide microsatellite in multiple sclerosis

In recent years, numerous reports have described the diverse roles of the CD40-CD40 ligand receptor-ligand pair. The interaction of these two cell-surface molecules regulates both humoral and cell-mediated immune functions. Because the CD40 ligand is known to be highly expressed on the peripheral blood mononuclear cells (PBMC) of multiple sclerosis (MS) patients, and because activated helper T cells expressing CD40 ligand have been found in the brain sections of MS patients, but not in those of normal controls, the protein is believed to be involved in MS development. We studied the influence of a polymorphic dinucleotide-repeat marker located in the 3' untranslated region of the X-linked gene encoding CD40 ligand (CD40LG) on susceptibility to and disease severity in MS. From a total cohort of 771 Nordic definite-MS patients, the most (n = 92) and least (n = 90) disabled octiles, as well as random samples of intermediately disabled males (n = 119) and females (n = 121), were genotyped; 135 ethnically matched healthy subjects were used as controls. In addition, the effect of the polymorphism on CD40 ligand mRNA expression was assessed using PBMC from 54 MS patients and 22 controls. The phenotype frequencies for the CD40LG marker did not differ significantly between gender-conditioned intermediate-MS subgroups and controls, or between gender-conditioned disability octiles. Nor did the polymorphism appear to exert any significant effect on mRNA expression in either patients or controls.

Modification of gold surface by grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion

Gold surfaces were first treated in an alkanethiol solution to form self-assembled monolayers (SAMs). The thiolated Au surface was then subjected to Ar plasma pretreatment, followed by air exposure and UV-induced graft polymerization of poly(ethylene glycol) methacrylate (PEGMA) macromonomer. In comparison with the 3-mercaptopropionic acid-2-ethylhexyl ester (MPAEE) SAM, the (3-mercaptoproply)trimethoxysilane (MPTMS) SAM on Au exhibited higher stability under the conditions of Ar plasma pretreatment. The graft concentration of the PEGMA polymer on SAM-modified Au surface increased with increasing PEGMA macromonomer concentration and UV-graft polymerization time. The modified-Au surfaces were characterized by X-ray spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle measurement. The Au surface with a high concentration of grafted PEGMA polymer could completely repel protein adsorption and platelet adhesion.

Effects of androgen supplementation therapy on partial androgen deficiency in the aging male: a preliminary study

OBJECTIVE

To assess the responses of a symptom complex related to partial androgen deficiency in the aging male (PADAM) to androgen supplementation.

SUBJECTS AND METHODS

Eighty-six men from five hospitals in Beijing aged 50-70 years with symptoms related to PADAM received oral testosterone undecanoate for 2 months, and the effects of the therapy were evaluated.

RESULTS

After treatment, the symptom scores were significantly improved (all p < 0.001). Serum levels of luteinizing hormone and follicle stimulating hormone were suppressed, and free testosterone and albumin-bound testosterone levels were elevated. However, they were not significantly different from the pretreatment values. Waist/hip ratio and blood pressure were markedly decreased, but no changes were found in serum levels of total cholesterol, triglyceride, albumin and prostate specific antigen.

CONCLUSIONS

Two months of treatment with oral testosterone undecanoate clearly improved the symptoms related to PADAM. No statistical relationship was found between symptom improvement and androgen levels. Androgen therapy for 2 months was beneficial to the waist/hip ratio and blood pressure, and no harm was done to the prostate gland or lipid metabolism.

Primary cerebral anaplastic large cell lymphoma containing abundant reactive histiocytes and eosinophils. A case report and literature review

Primary cerebral anaplastic large cell lymphoma (ALCL) is very rare. We report on our experience with such a case and review the literature. A 46-year-old Taiwanese woman presented with headache, weakness of her right extremity, and limited eye movement. A solid mass (5 cm x 4 cm) at the left occipital lobe was almost completely removed. The neoplastic cells, some of which had reniform or embryo-like nuclei, were large and were admixed with abundant eosinophils, histiocytes, and some small lymphocytes. These neoplastic cells expressed CD30, CD43, granzyme B and T-cell intracellular antigen-1, but not ALK1, CD3, CD20, CD45, CD79a, cytokeratin, and EMA. They were positive for Epstein-Barr virus-encoded mRNA by in situ hybridization. Polymerase chain reaction study of formalin-fixed tissue showed a clonal gene arrangement of the T-cell receptor-gamma chain. ALCL of T-cell lineage with cytotoxic phenotype was diagnosed. The patient received cranial irradiation and has remained with no evidence of disease for 25 months of follow-up.

Chimerism Analysis in Sex-Mismatched Murine Transplantation Using Quantitative Real-Time PCR

Murine experimental stem cell transplantations require the accurate discrimination and quantification of donor cells from host cells. A Y-chromosome-specific, quantitative real-time PCR (kinetic PCR) protocol for blood-derived DNA was developed. The assay sensitivity was extremely high with accurate detection of only 10 pg (six copies of Y target DNA) in a variable background of female DNA background ranging from 2.5 to 50 ng. The dynamic range of the assay provided accurate results ranging from 2.2 × 10−2% to 100% of male DNA in female background. The kinetic PCR assay can be used in all mouse strains, and a sample size as low as 2.5 ng total DNA is sufficient for analysis. Therefore, kinetic PCR allows engraftment kinetic studies on repeated blood draws of individual animals with no need for sacrifice. Compared to conventional PCR, the assay is much simplified, as neither the accurate adjustment of sample DNA concentration nor a post-reaction analysis procedure is required. The procedure is simple, free of radioactivity, and permits a throughput of 500–600 reactions per day.

Chimerism analysis in sex-mismatched murine transplantation using quantitative real-time PCR

Marine experimental stem cell transplantations require the accurate discrimination and quantification of donor cells from host cells. A Y-chromosome-specific, quantitative real-time PCR (kinetic PCR) protocol for blood-derived DNA was developed. The assay sensitivity was extremely high with accurate detection of only 10 pg (six copies of Y target DNA) in a variable background of female DNA background ranging from 2.5 to 50 ng. The dynamic range of the assay provided accurate results ranging from 2.2 x 10(-2)% to 100% of male DNA in female background. The kinetic PCR assay can be used in all mouse strains, and a sample size as low as 2.5 ng total DNA is sufficient for analysis. Therefore, kinetic PCR allows engraftment kinetic studies on repeated blood draws of individual animals with no need for sacrifice. Compared to conventional PCR, the assay is much simplified, as neither the accurate adjustment of sample DNA concentration nor a post-reaction analysis procedure is required. The procedure is simple, free of radioactivity, and permits a throughput of 500-600 reactions per day.