Showing papers by "Rappaport Faculty of Medicine published in 1998"
TL;DR: The results show that the BRCT domains interact in vivo with CtIP, a protein originally identified on the basis of its association with the CtBP transcriptional co-repressor, suggesting that BRCA1 regulates gene expression, at least in part, by modulating CtBP-mediated transcriptional repression.
394 citations
TL;DR: It is reported that the degradation of the myc proteins in cells is inhibited by lactacystin and MG132, two inhibitors of the 20S proteasome.
Abstract: We have previously shown that the degradation of c-myc and N-myc in vitro is mediated by the ubiquitin system. However, the role of the system in targeting the myc proteins in vivo and the identity of the conjugating enzymes and possible ancillary proteins involved has remained obscure. Here we report that the degradation of the myc proteins in cells is inhibited by lactacystin and MG132, two inhibitors of the 20S proteasome. Inhibition is accompanied by accumulation of myc-ubiquitin conjugates. Dissection of the ancillary proteins involved revealed that the high-risk human papillomavirus oncoprotein E6-16 stimulates conjugation and subsequent degradation of the myc proteins in vitro. Expression of E6-16 in cells results in significant shortening of the t1/2 of the myc proteins with subsequent decrease in their cellular level. Analysis of the conjugating enzymes revealed that under basal conditions the proteins can be conjugated by two pairs of E2s and E3s—E2-14 kDa and E3α involved in the “N-end rule” pathway, and E2-F1 (UbcH7) and E3-Fos involved also in conjugation of c-Fos. In the presence of E6-16, a third pair, E2-F1 and E6-AP mediate conjugation of myc by means of a mechanism that appears to be similar to that involved in the targeting of p53, formation of a myc⋅E6⋅E6–AP targeting complex. It is possible that in certain cells E6-mediated targeting of myc prevents myc-induced apoptosis and thus ensures maintenance of viral infection.
230 citations
TL;DR: Macrophage enrichment with polyphenolic flavonoids in vitro or in vivo also reduce macrophage oxidative state, and subsequently cell-mediated oxidation of LDL, which is a hallmark in early atherosclerosis.
181 citations
TL;DR: In the canine model and patients, local endocardial shortening was significantly impaired in MI zones compared with controls, and preliminary data suggest that infarctedMyocardium could be accurately diagnosed and distinguished from healthy myocardium by a reduction in both electrical voltage and mechanical activity.
Abstract: Background —A catheter-based left ventricular (LV) endocardial mapping procedure using electromagnetic field energy for positioning of the catheter tip was designed to acquire simultaneous measurements of endocardial voltage potentials and myocardial contractility. We investigated such a mapping system to distinguish between infarcted and normal myocardium in an animal infarction model and in patients with coronary artery disease.
Methods and Results —Measurements of LV endocardial unipolar (UP) and bipolar (BP) voltages and local endocardial shortening were derived from dogs at baseline (n=12), at 24 hours (n=6), and at 3 weeks (n=6) after occlusion of the left anterior descending coronary artery. Also, 12 patients with prior myocardial infarction (MI) and 12 control patients underwent the LV endocardial mapping study for assessment of electromechanical function in infarcted versus healthy myocardial regions. In the canine model, a significant decrease in voltage potentials was noted in the MI zone at 24 hours (UP, 42.8±9.6 to 29.1±12.2 mV, P =0.007; BP, 11.6±2.3 to 4.9±1.2 mV, P <0.0001) and at 3 weeks (UP, 41.0±8.9 to 13.9±3.9 mV, P <0.0001; BP, 11.2±2.8 to 2.4±0.4 mV, P <0.0001). No change in voltage was noted in zones remote from MI. In patients with prior MI, the average voltage was 7.2±2.7 mV (UP)/1.4±0.7 mV (BP) in MI regions, 17.8±4.6 mV (UP)/4.5±1.1 mV (BP) in healthy zones remote from MI, and 19.7±4.4 mV (UP)/5.8±1.0 mV (BP) in control patients without prior MI ( P <0.001 for MI values versus remote zones or control patients). In the canine model and patients, local endocardial shortening was significantly impaired in MI zones compared with controls.
Conclusions —These preliminary data suggest that infarcted myocardium could be accurately diagnosed and distinguished from healthy myocardium by a reduction in both electrical voltage and mechanical activity. Such a diagnostic electromechanical mapping study might be clinically useful for accurate assessment of myocardial function and viability.
177 citations
TL;DR: Although Levite Y chromosomes are diverse, Cohen chromosomes are homogeneous, and this work traces the origin of Cohen chromosomes to about 3,000 years before present, early during the Temple period.
Abstract: According to Jewish tradition, following the Exodus from Egypt, males of the tribe of Levi, of which Moses was a member, were assigned special religious responsibilities, and male descendants of Aaron, his brother, were selected to serve as Priests (Cohanim). To the extent that patrilineal inheritance has been followed since sometime around the Temple period (roughly 3,000-2,000 years before present), Y chromosomes of present-day Cohanim and Levites should not only be distinguishable from those of other Jews1, but — given the dispersion of the priesthood following the Temple's destruction — they should derive from a common ancestral type no more recently than the Temple period. Here we show that although Levite Y chromosomes are diverse, Cohen chromosomes are homogeneous. We trace the origin of Cohen chromosomes to about 3,000 years before present, early during the Temple period.
166 citations
TL;DR: It appears that a significant proportion of children with ADHD have a language comorbidity not reflected by IQ assessments; therefore, language tests should be considered as part of their routine assessment.
Abstract: The aim of this study was to delineate the prevalence and behavioral patterns of children with attention-deficit and language problems as compared to children with attention-deficit hyperactivity disorder (ADHD) only. Out of a cohort of 3208 children 6 to 11 years old, 5.2% were identified as having a primary ADHD. A teacher's behavioral questionnaire, pediatric interview and assessment, IQ, attention tests, and language evaluation were employed. A 45% rate of language problems was identified. This comorbidity is more prevalent among girls (P = .02). Sequencing and short-term memory were significantly related to attention-deficit and language problems, but the attention scores were not. Language performance was the best predictor of group assignment and was superior to IQ in that regard. Correlation analysis revealed a different behavioral pattern for the two groups. It appears that a significant proportion of children with ADHD have a language comorbidity not reflected by IQ assessments; therefore, language tests should be considered as part of their routine assessment. Children with attention-deficit and language problems appear to have a different neurocognitive pattern underlying their problems as compared with their peers with ADHD only.
165 citations
Journal Article•
TL;DR: It is suggested that perturbation of the Th1/Th2 balance toward Th2 cells is the mechanism underlying EAE blockade by anti-IGIF immunotherapy.
Abstract: Specific oligonucleotide primers were used to identify and isolate IFN-γ-inducing factor (IGIF) from the brain of rats with developing experimental autoimmune encephalomyelitis (EAE), a T cell-mediated autoimmune disease of the central nervous system that serves as a model for multiple sclerosis. IGIF was highly transcribed in the brain at the onset and during the course of active EAE. PCR products encoding rat IGIF were used to generate the recombinant protein that was used to induce anti-IGIF neutralizing Abs. These Abs significantly reduced the production of IFN-γ by primed T cells proliferating in response to their target myelin basic protein epitope and by Con A-activated T cells from naive donors. When administered to rats during the development of either active or transferred EAE, these Abs significantly blocked the development of disease. Splenic T cells from protected rats were cultured with the encephalitogenic myelin basic protein epitope and evaluated for production of IL-4 and IFN-γ. These cells, which proliferated, exhibited a profound increase in IL-4 production that was accompanied by a significant decrease in IFN-γ and TNF-α production. Thus, we suggest that perturbation of the Th1/Th2 balance toward Th2 cells is the mechanism underlying EAE blockade by anti-IGIF immunotherapy.
164 citations
TL;DR: The in vivo and in vitro reduction of the susceptibility of LDL to oxidation obtained with glabridin, may be related to the absorption or binding of gl abridin to the LDL particle and subsequent protection of LDL from oxidation by inhibiting the formation of lipid peroxides and oxysterols, and by protecting LDL associated carotenoids.
158 citations
TL;DR: It is suggested that E4orf4 antagonizes continuous signals to proliferate, like those given by E1A or v-Ras, and that the conflicting signals lead to the induction of cell death.
Abstract: Adenovirus type 5 E4 open reading frame 4 (E4orf4) protein has been previously shown to counteract transactivation of the junB and c-fos genes by cyclic AMP plus E1A protein and to interact with protein phosphatase 2A (PP2A). Here, we show that the wild-type E4orf4 protein induces apoptosis in the E1A-expressing 293 cells, in NIH 3T3 cells transformed with v-Ras, and in the lung carcinoma cell line H1299. The induction of apoptosis is not accompanied by enhanced levels of p53 in 293 cells and occurs in the absence of p53 in H1299 cells, indicating involvement of a p53-independent pathway. A mutant E4orf4 protein that had lost the ability to induce apoptosis also lost its ability to bind PP2A. We suggest that E4orf4 antagonizes continuous signals to proliferate, like those given by E1A or v-Ras, and that the conflicting signals lead to the induction of cell death.
143 citations
TL;DR: The segregation pattern of the mutation which is the first reported in the γ-glutamyl carboxylase gene fits perfectly with phenotype of the disorder and confirms the suggested autosomal recessive pattern of inheritance of combined deficiency of all vitamin K-dependent procoagulants and anticoagulant in this kindred.
142 citations
Journal Article•
TL;DR: Modulation of EAE with C-C chemokine DNA vaccines is dependent on targeting chemokines that are highly transcribed at the site of inflammation at the onset of disease.
Abstract: DNA vaccination represents a novel means of expressing Ag in vivo for the generation of both humoral and cellular immune responses. The current study uses this technology to elicit protective immunity against experimental autoimmune encephalomyelitis (EAE), a T cell-mediated autoimmune disease of the central nervous system that serves as an experimental model for multiple sclerosis. RT-PCR verified by Southern blotting and sequencing of PCR products of four different C-C chemokines, macrophage-inflammatory protein-1alpha (MIP-1alpha), monocyte-chemotactic protein-1 (MCP-1), MIP-1beta, and RANTES, were performed on brain samples from EAE rats to evaluate mRNA transcription at different stages of disease. Each PCR product was then used as a construct for naked DNA vaccination. The subsequent in vivo immune response to MIP-1alpha or MCP-1 DNA vaccines prevented EAE, even if disease was induced 2 mo after administration of naked DNA vaccines. In contrast, administration of the MIP-1beta naked DNA significantly aggravated the disease. Generation of in vivo immune response to RANTES naked DNA had no notable effect on EAE. MIP-1alpha, MCP-1, and MIP-1beta mRNA transcription in EAE brains peaked at the onset of disease and declined during its remission, whereas RANTES transcription increased in EAE brains only following recovery. Immunization of CFA without the encephalitogenic epitope did not elicit the anti-C-C chemokine regulatory response in DNA-vaccinated rats. Thus, modulation of EAE with C-C chemokine DNA vaccines is dependent on targeting chemokines that are highly transcribed at the site of inflammation at the onset of disease.
TL;DR: Cardiac antioxidants were demonstrated to change in a systematically organized relationship under ischemia-reperfusion, and this graded utilization of antioxidants supports the redox based antioxidant network concept, found to be present in other biological systems.
TL;DR: The results suggest that the antioxidant effect of glabridin on LDL oxidation appears to reside mainly in the 2' hydroxyl, and that the hydrophobic moiety of the isoflavan is essential to obtain this effect.
TL;DR: Because HMG-CoA reductase inhibitors can inhibit platelet aggregation, macrophage foam cell formation, and LDL oxidation, major contributors to atherogenesis, the use of these drugs can significantly attenuate the atherosclerotic process.
Abstract: To assess the effect of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on plasma cholesterol concentrations and on platelet aggregation, lovastatin or fluvastatin, 40 mg daily, was given to hypercholesterolemic patients. After 24 weeks, plasma low-density lipoprotein (LDL) cholesterol concentrations were reduced by 37% after lovastatin therapy and 29% after fluvastatin therapy. The platelet cholesterol/phospholipid ratio was reduced by 33% and 26%, respectively. Platelet aggregation was significantly reduced by 12-15% (p < 0.01) after 4 weeks of therapy with either agent. Lovastatin or fluvastatin therapy reduced platelet aggregation through an in vivo hypocholesterolemic action on the platelet cholesterol content and also through a direct effect on platelet function, as a result of drug binding to the platelets. We also studied the effect of these HMG-CoA reductase inhibitors on LDL susceptibility to oxidation. LDL oxidation (induced by copper ions) was reduced by 31% after lovastatin therapy and by 37% after fluvastatin therapy. The inhibitory effect of HMG-CoA reductase inhibitors on LDL oxidation involved their stimulatory effect on the removal of LDL from the circulation and a direct binding effect of the drugs to the lipoprotein. Because HMG-CoA reductase inhibitors can inhibit platelet aggregation, macrophage foam cell formation, and LDL oxidation, major contributors to atherogenesis, the use of these drugs can significantly attenuate the atherosclerotic process.
TL;DR: Cariel T.M. is an enriched serum-free cell culture medium, its ability to enhance the survival of human aspirated fat grafts was investigated in the nude mouse model, and it seems that addition of the nutrients enriched with anabolic hormones enabled the survival and take of more adipose cells in the graft.
Abstract: Injection of aspirated fat is now the most commonly used technique for the filling of depressed areas. Partial absorption of the injected fat is the main limitation of this procedure. Cariel T.M. is an enriched serum-free cell culture medium, its ability to enhance the survival of human aspirated fat grafts was investigated in the nude mouse model. A volume of 0.75-cc Cariel preprocessed fat was injected under the scalp skin of 16 nude mice in the experimental group, and the same volume of saline preprocessed fat was injected to 15 control group of mice. Significant maintenance of the weight, 46 percent in the experimental group compared with 29 percent in the control group (p < 0.008), and the volume, 44 percent in the experimental group compared with 31 percent in the control group (p < 0.026), was observed, after 15 weeks, in this newly used model. It seems that addition of the nutrients enriched with anabolic hormones enabled the survival and take of more adipose cells in the graft.
TL;DR: Results hint that at least in mammary gland CIS3 is likely the main physiological negative regulator of the PRLR‐mediated JAK2/STAT5 pathway.
TL;DR: The data show that there is a marked downregulation of all KD channel α subunits from P1–P4 to P40 in the sciatic nerve and confirm that KD channels are involved in SC proliferation.
Abstract: Schwann cells (SCs) are responsible for myelination of nerve fibers in the peripheral nervous system. Voltage-dependent K 1 currents, including inactivating A-type (KA), delayed-rectifier (KD ), and inward-rectifier (KIR )K 1 channels, constitute the main conductances found in SCs. Physiological studies have shown that KD channels may play an important role in SC proliferation and that they are downregulated in the soma as proliferation ceases and myelination proceeds. Recent studies have begun to address the molecular identity of K 1 channels in SCs. Here, we show that a large repertoire of K 1 channel a subunits of the Shaker (Kv1.1, Kv1.2, Kv1.4, and Kv1.5), Shab (Kv2.1), and Shaw (Kv3.1b and Kv3.2) families is expressed in mouse SCs and sciatic nerve. We characterized heteromultimeric channel complexes that consist of either Kv1.5 and Kv1.2 or Kv1.5 and Kv1.4. In postnatal day 4 (P4) sciatic nerve, most of the Kv1.2 channel subunits are involved in heteromultimeric association with Kv1.5. Despite the presence of Kv1.1 and Kv1.2 a subunits, the K 1 currents were unaffected by dendrotoxin I (DTX), suggesting that DTX-sensitive channel complexes do not account substantially for SC KD currents. SC proliferation was found to be potently blocked by quinidine or 4-aminopyridine but not by DTX. Consistent with previous physiological studies, our data show that there is a marked downregulation of all KD channel a subunits from P1‐P4 to P40 in the sciatic nerve. Our results suggest that KD currents are accounted for by a complex combinatorial activity of distinct K 1 channel complexes
TL;DR: It is confirmed that a nonprotective IgG3 MAb can be converted to a protective MAb by isotype switching, and the efficacy of protection of an IgG1 MAbCan be increased by isotypes switching to another subclass, as well as showing that protective and nonprot protective IgG MAbs are opsonic.
Abstract: The isotype and epitope specificities of antibodies both contribute to the efficacy of antibodies that mediate immunity to Cryptococcus neoformans, but the relationship between these properties is only partially understood. In this study, we analyzed the efficacy of protection of two sets of immunoglobulin G (IgG) isotype switch variants from two IgG3 monoclonal antibodies (MAbs) which are either not protective or disease enhancing, depending on the mouse model used. The two IgG3 MAbs 3E5 and 4H3 have different epitope specificities. Protection experiments were done with A/JCr mice infected intravenously with C. neoformans and administered with 3E5 IgG3 and its IgG1, IgG2a, and IgG2b switch variants. These experiments revealed that IgG1, IgG2b, and IgG2a were each more effective than IgG3. For 4H3 IgG3 and its IgG1 and IgG2b switch variants, the relative efficacy was IgG2b > IgG1 >> IgG3. The combination of 3E5 IgG3 and 4H3 IgG3 was more deleterious than either IgG3 alone. All IgG isotypes were opsonic for mouse bronchoalveolar cells, with the relative efficacy being IgG2b > IgG2a > IgG1 > IgG3. These results (i) confirm that a nonprotective IgG3 MAb can be converted to a protective MAb by isotype switching, (ii) indicate that the efficacy of protection of an IgG1 MAb can be increased by isotype switching to another subclass, (iii) show that protective and nonprotective IgG MAbs are opsonic, and (iv) provide additional evidence for the concept that the efficacy of the antibody response to C. neoformans is dependent on the type of MAb elicited.
TL;DR: BzR ligands (clonazepam, diazepam, PK11195 and Ro5-4864) were found to exert antitumor effects in B16 melanoma cells, and encourage further studies of a possible therapeutic potential of BzRligands in treatment of melanoma.
TL;DR: This review focuses on HuR, an RNA-binding protein which has recently been shown is critical for the hypoxic stabilization of VEGF mRNA.
TL;DR: Results indicate that rasagiline has potential for the treatment of Parkinson's Disease and this compound is currently under development for that indication.
Abstract: (+)-N-Propargyl-1-aminoindan (rasagiline) and a series of derivatives have been synthesized and screened for monoamine oxidase inhibitory activity. Rasagiline and several analogues were found be highly selective and potent inhibitors of the B form of the enzyme in contrast to the levorotatory enantiomer which was not active. The results indicate that rasagiline has potential for the treatment of Parkinson’s Disease. This compound is currently under development for that indication.
TL;DR: The role of GH and IGF-I in normal and malignant haemopoiesis is summarized and their possible contribution to the development of leukemia should be considered.
Abstract: The process of haemopoiesis, occurring primarily within the bone marrow, involves the proliferation and differentiation of pluripotent haemopoietic stem cells into committed, or pathway-restricted progenitors /1/. The latter further proliferate and undergo a process of maturation into circulating blood cells of myeloid and erythroid lineages /2/. Haemopoietic cell growth and differentiation is primarily regulated by the local production of various cytokines within the bone marrow micro-environment /3/, as well as by the circulating hormone, erythropoietin (EPO). The formation as well as functional activation of mature blood cells, are also modulated by a variety of hormones and growth peptides, including growth hormone (GH) and insulin-like growth factor-I (IGF-I) /4,5/. Early evidence for the role of GH in modulating haemopoiesis was provided in classical studies in rodents, which showed that removal of the pituitary gland affects blood cell formation and function /6/ and that impairment of the latter can be restored by GH administration /7/. GH exerts its effects on target cells by binding to its own receptor, which belongs to the class I cytokine receptor superfamily /8/. In humans, GH can also bind to and activate the prolactin receptor /9/. Based on the somatomedin hypothesis of Salmon and Daughaday /10/, it is now generally accepted that, in addition to the above, GH exerts many of its effects via autocrine or paracrine IGF-I, as well as via endocrine IGF-I produced in the liver. IGF-I, a small single-chain polypeptide, is one of two highly homologous peptides (IGF-I and IGF-II), that stimulate the proliferation and differentiation of a wide variety of cell types, including bone marrow cells /5,11/. Both IGF-I and IGF-II play an important role in prenatal growth and IGF-I is also essential for postnatal growth and development /12/. Two types of IGF receptors have been described. The type I IGF receptor, a tyrosine kinase receptor highly homologous to the insulin receptor, binds IGF-I and IGF-II with a high affinity. The type II/mannose 6-phosphate receptor which lacks intrinsic kinase activity, binds IGF-II with a high affinity and IGF-I with a low affinity /13,14/. Haemopoietic progenitors and mature blood cells have been shown to produce GH and IGF-I and to express receptors for these peptides. GH and IGF-I may act independently on these cells or, as more commonly observed, in a synergistic manner with primary haemopoietic cytokines. GH and IGF-I receptors are also present on freshly explanted leukemic cells and leukemic cell lines. Thus, their possible contribution to the development of leukemia should also be considered. This review summarizes our current understanding of the role of GH and IGF-I in normal and malignant haemopoiesis.
TL;DR: This is a first report of an H+/K+ transporter in microglia cells with a Kd in the physiological range of [K+]out, and it is suggested that a K/H ATPase is the major generator of both the potassium and the proton gradients.
Abstract: An ion selective electrode in self-referencing mode was employed to detect ionic concentration gradients at the vicinity of microglia isolated from newborn rat brains. At 5 mM extracellular potassium concentration, a gradient of -9.43+/-4.2 microM (n=48) was recorded dissipating over a distance of 10 microm from the outer surface of the cell membrane. Pharmacological studies indicated that neither the Na+/K+-ATPase nor the inward rectifier potassium channel makes significant contributions to generation of this gradient. The recorded potassium gradient was found to be augmented by increase in extracellular potassium or proton concentrations and could be inhibited by Omeprazole (10 microM) and by the specific H+/K+-ATPase blocker SCH28080 (1 microM). These, along with the coexistence of a gradient of excess of protons, strongly suggest that a K/H ATPase is the major generator of both the potassium and the proton gradients. The Kd of the glial transporter for K ions is an order of magnitude higher (3.7 mM) than that of the epithelial H+/K+-ATPase. This is a first report of an H+/K+ transporter in microglia cells with a Kd in the physiological range of [K+]out. Implications of the H+/K+-ATPase on potassium homeostasis in microglia under high extracellular potassium and low pH, as found at the site of brain injury, are discussed.
TL;DR: Inhibition of the expression of each of the channels suppressed progenitor cell generation by IL‐3 and SCF‐stimulated CD34+38− cells in 7‐day suspension cultures, suggesting a potentially important role in potassium homeostasis in these cells.
Abstract: A potassium inward rectifier (K(ir)) current was previously shown by us to be induced in primitive hematopoietic progenitor cells, stimulated with the combination of interleukin-3 (IL-3) and stem cell factor (SCF). Biophysical features of whole cell currents implicated the involvement of more than one K(ir) channel type. Employing IL-3 + SCF stimulated human cord blood CD34+38- cells, we isolated and characterized different components of this current. Reverse transcription-polymerase chain reaction (RT-PCR) subcloning identified the expression of a strongly rectifying K(ir) channel (K(ir) 4.3) as well as a weakly rectifying K(ir) channel (K(ir) 1.1) in these cells. Inhibition of the expression of each of the channels suppressed progenitor cell generation by IL-3 and SCF-stimulated CD34+38- cells in 7-day suspension cultures. The variable expression of two essential inward rectifying potassium channels early in the course of hematopoietic progenitor cell differentiation may play a potentially important role in potassium homeostasis in these cells.
TL;DR: A substantial contribution of macrophage-associated GAGs is demonstrated in the catabolism of Ox-LDL, which is mediated in part by a cooperation between GAGS and cell-surface SR-As.
Abstract: Macrophage binding sites for oxidized LDL (Ox-LDL) include class A scavenger receptors (SR-As), the CD-36 molecule, and an additional but hitherto unidentified binding site. Because cell-surface glycosaminoglycans (GAGs) were previously shown to be involved in the cellular uptake of native LDL and lipoprotein(a), several strategies to assess the participation of heparan sulfate (HS) and chondroitin sulfate (CS) in macrophage catabolism of Ox-LDL were used. First, incubation of J-774 A.1 macrophage-like cells with either heparinase or chondroitinase, or with both enzymes together, reduced the binding, uptake, and degradation of 125I-Ox-LDL by 20% to 45%, in comparison with control nontreated cells, while catabolism of 125I-labeled acetylated LDL (Ac-LDL) and native LDL were unaffected. Second, the proteoglycan (PG) cellular content was increased by cell enrichment with exogenous GAGs or by using human monocyte-derived macrophages from two patients with Sanfilippo mucopolysaccharidosis, which are characterized by cellular HS accumulation. In these macrophages, cellular uptake of 125I-Ox-LDL increased, while catabolism of 125I-Ac-LDL and native LDL were unaffected. Experiments using conditioned media from control, heparinase-digested, or chondroitinase-digested macrophages indicated that neither secreted GAGs nor released digestion products played any role in Ox-LDL catabolism. To evaluate potential interactions between cell-surface GAGs and known receptors for Ox-LDL, we used excess unlabeled Ac-LDL to block SR-As or anti-CD-36 antibodies to block CD-36, and then examined the catabolism of 125I-Ox-LDL by GAG-enriched or -depleted macrophages. Both excess unlabeled Ac-LDL and anti-CD-36 antibodies reduced 125I-Ox-LDL catabolism, but only excess unlabeled Ac-LDL completely abolished the increase in 125I-Ox-LDL catabolism on GAG enrichment of the cells, indicating a cooperation between exogenous GAGs and cell-surface SR-As in the catabolism of OX-LDL. Moreover, the addition of GAGases to macrophages that were preincubated with anti-CD-36 antibodies and excess Ac-LDL further reduced macrophage degradation of Ox-LDL in comparison with cells that were pretreated only with anti-CD-36 antibodies and Ac-LDL, indicating a more complex role for endogenous GAGs. Overall, these studies demonstrate a substantial contribution of macrophage-associated GAGs in the catabolism of Ox-LDL, which is mediated in part by a cooperation between GAGs and cell-surface SR-As.
TL;DR: A new case of central granular cell odontogenic tumor is presented with emphasis on its clinical and radiologic features and critically review and analyze previously published case reports.
TL;DR: In this article, a simple, low-cost, sensitive and selective HPLC method was developed for the determination of doxycycline in human plasma, which has a detection limit of 0.008 μg mL−1 and a limit of quantification of 2.02 μg mL −1.
Abstract: A simple, low-cost, sensitive and selective HPLC method was developed for the determination of doxycycline in human plasma. The method has a detection limit of 0.008 μg mL−1 and a limit of quantification of 0.02 μg mL−1. Calibration curves were linear over a large dynamic range, namely within 0.02–5.0 μg mL−1, which allowed accurate determination of doxycycline peak levels in human plasma after administration of 50–200 mg tablets and also the low plasma levels obtained 72 hours after drug administration.
TL;DR: In this study, IVIg (Sandoglobin) was examined for complement binding moieties which resemble immune complexes and can mediate the binding of IgG and C′3b to human erythrocytes via CR1 and enhance ERYthrocyte susceptibility to sequestration.
Abstract: Treatment with IVIg can, on rare occasions, lead to detrimental effects such as enhanced erythrocyte sequestration and an increase in serum immune complexes with inflammatory sequellae such as exacerbation of glomerular nephritis. In this study, IVIg (Sandoglobin) was examined for complement binding moieties which resemble immune complexes and can mediate the binding of IgG and C′3b to human erythrocytes via CR1 and enhance erythrocyte susceptibility to sequestration. Sephacryl S-200 HR separated IVIg into two fractions: monomeric IgG (74%) and larger complexes of the molecular weight of an IgG dimer or greater (≥ 300 kD) (26%). In the presence of complement, the ‘dimers’ bound to human erythrocytes, rendering them susceptible to phagocytosis in vitro. Removal of erythrocyte-specific isoantibodies from the IVIg had no effect on ‘dimer’ binding to the erythrocytes. Monomeric IgG contained virtually no complement-activating, erythrocyte-binding activity. Erythrocyte binding of complement-bearing IgG ‘dimers’ and subsequent phagocytosis resembles the binding of complement-bearing immune complexes to erythrocyte CR1. Exposure to Factor I leads to the release of complement-bearing IgG ‘dimers’ from erythrocyte CR1 and to the abrogation of erythrophagocytosis. Binding of complement-bearing IgG ‘dimers’ to the erythrocyte is blocked by To5, a CR1-specific monoclonal antibody.
TL;DR: By using homozygosity mapping and two consanguineous affected kindreds of Israeli-Arab origin, including five patients, linkage of a MoCoD gene to an 8-cM region on chromosome 6p21 is demonstrated and can be used to perform prenatal diagnosis with microsatellite markers.
Abstract: Molybdenum cofactor deficiency (MoCoD) is a fatal disorder manifesting, shortly after birth, with profound neurological abnormalities, mental retardation, and severe seizures unresponsive to any therapy. The disease is a monogenic, autosomal recessive disorder, and the existence of at least two complementation groups suggests genetic heterogeneity. In humans, MoCoD leads to the combined deficient activities of sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase. By using homozygosity mapping and two consanguineous affected kindreds of Israeli-Arab origin, including five patients, we demonstrated linkage of a MoCoD gene to an 8-cM region on chromosome 6p21.3, between markers D6S1641 and D6S1672. Linkage analysis generated the highest combined LOD-score value, 3.6, at a recombination fraction of 0, with marker D6S1575. These results now can be used to perform prenatal diagnosis with microsatellite markers. They also provide the only tool for carrier detection of this fatal disorder.
TL;DR: A step-by-step manual for chronic cannulation of rats using a simple technique that facilitates repeated clamping of the same rat over a 6-10-week period is presented.