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Publication
Journal: Journal of Neuroscience
January/27/1988
Abstract
Utilizing 125I-BSA administered intravenously, a simple, reliable, and sensitive method was established for the detection of plasma protein extravasation in the dura of rats and guinea pigs following chemical, electrical, or immunological stimulation. Extravasated 125I-BSA or Evans blue was noted in the dura and conjunctiva but not in the temporalis muscle of saline-perfused rats following intravenous capsaicin, 1 mumol/kg. Capsaicin-induced extravasation was mediated by unmyelinated and small myelinated fibers since leakage did not develop in adult animals in whom these fibers were destroyed by capsaicin pretreatment (50 mg/kg) as neonates. An ipsilateral increase in Evans blue and 125I-BSA was found in the dura, eyelids, lips and gingival mucosa, and snout following electrical stimulation of the rat trigeminal ganglion. This increase was also C-fiber dependent. Among those peptides contained in perivascular afferent fibers and administered intravenously, substance P (SP) and neurokinin A (NKA), but not calcitonin gene-related peptide, caused a dose-dependent extravasation in the dura and conjunctiva of rats. Neonatal capsaicin pretreatment did not attenuate SP- nor NKA-induced effects in the dura and actually increased extravasation in the conjunctiva. Intravenous administration of 5-HT or bradykinin to normal adult rats or adult rats pretreated as neonates with capsaicin increased levels of 125I-BSA in both the dura and the conjunctiva. Histamine and prostaglandin E2, on the other hand, caused protein leakage in the conjunctiva but not in the dura of rats; however, histamine did induce extravasation in the dura of guinea pigs.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication
Journal: Hepatology
December/28/2004
Abstract
Adefovir dipivoxil was recently approved for the treatment of wild-type and lamivudine-resistant hepatitis B virus (HBV) infection. Tenofovir disoproxil fumarate, a congender of adefovir that is used in the treatment of HIV infected patients, has recently been shown to also be effective in patients with lamivudine-resistant HBV infection. We therefore compared the two substances in a study of 53 patients defined by high HBV DNA (>6 log10 copies/mL) levels and genotypic evidence of lamivudine resistance. Thirty-five patients received tenofovir for 72 to 130 weeks, and 18 received adefovir for 60 to 80 weeks. Changes in HBV DNA levels were followed for the complete period of 48 weeks. Early viral kinetics were compared on matched subgroups of 5 patients each. Individually, all tenofovir-treated patients showed a strong and early suppression of HBV DNA within a few weeks whether they were coinfected with HIV or were without comorbidity. In contrast, considerable individual variations in HBV DNA decline were observed in the adefovir group. Thus at week 48, only 44% of these patients had HBV DNA levels below 10(5) copies/mL in contrast to 100% of the tenofovir-treated patients (P = .001). No severe side effects were noticed in either group. No evidence of phenotypic viral resistance could be demonstrated in the tenofovir-treated patients in the long term (up to 130 weeks). In conclusion, tenofovir may become an effective alternative for the treatment of patients with lamivudine-resistant HBV infection.
Publication
Journal: Brain Research
August/29/1984
Abstract
The central nucleus of the amygdala (ACe) in the rat sends a considerable projection to, and receives projections from, the parabrachial nucleus (PB) and the dorsal vagal complex (DVC; the nucleus of the solitary tract and the dorsal motor nucleus of the vagus nerve). In each part of this 'triangle', immunohistochemical staining for the following peptides has been observed in perikarya and fibers: neurotensin, somatostatin, substance-P, Leu-enkephalin and corticotropin-releasing factor. The aim of the present study was to investigate whether any of these peptides are involved in projections to the brainstem from the ACe, and to characterize the distribution of each cell type in the ACe. The results of double retrograde tracing studies indicate that most of the ACe neurons projecting to the PB and DVC are present in the medial part of ACe (ACem), and that many of them project to both the 1 B and the DVC. The combined use of immunohistochemistry with a retrograde fluorescent tracer, True Blue, indicated that the peptide-containing perikarya are found predominantly in the lateral part of ACe (ACe1), and that only a small proportion of neurotensin, somatostatin and corticotropin-releasing factor-stained neurons contained True Blue after injections into the PB or the DVC. The results suggest that most of the fibers in the descending projection from the ACe to the brainstem do not contain the peptides examined here.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
June/8/1987
Abstract
Inflammatory or allergic conditions, as well as situations where healing and repair processes occur, are characterized by the presence of increased numbers of mast cells. Previous work on the effect of neuropeptides on mast cell mediator release showed that only substance P caused such release from intestinal mucosal mast cells [Shanahan, F., Denburg, J. A., Fox, J., Bienenstock, J. & Befus, A. D. (1985) J. Immunol. 135, 1331-1337]. Accordingly, we investigated the microanatomical relationship between mast cells and enteric nerves in normal rat intestine and parasite-infected rat intestine, in which mucosal mast cell hyperplasia occurs. Combined immunohistochemistry for neuron-specific enolase and staining with alcian blue at pH 0.5 was employed on paraffin-embedded sections of normal and Nippostrongylus brasiliensis-infected rat jejunum. Sixty-seven percent of intestinal mucosal mast cells were touching subepithelial nerves, and an additional 20% were within 2 micron of nerves. Assessment of the proportion of the lamina propria occupied by mast cells (12.5%), the average mast cell area (121 +/- 28 microns 2), and the density of enteric nerves (one per 788 +/- 151 microns 2) suggested that the association was 5 times greater than would be expected by chance alone (P less than 0.0001). In consecutive sections, the nerves in contact with mast cells were also shown to contain substance P and/or calcitonin-gene-related peptide. Electron microscopy confirmed this association: 8% of the mast cells in infected rats exhibited membrane-membrane contact with unmyelinated axons containing 70- to 170-nm dense-core vesicles, and an additional 31% were situated less than 250 nm from nerves. Other mast cells appeared to embrace nerve bundles through the projection of lamellopodia. These data provide systematic quantitative evidence that a structural foundation for communication between the immune and nervous systems exists in the rat gastrointestinal tract.
Publication
Journal: Hypertension
October/15/2002
Abstract
Angiotensin II plays an important role in vascular remodeling. We investigated the role of aldosterone, which is stimulated by angiotensin II, as a mediator of angiotensin II-induced vascular structural and functional alterations. Sprague-Dawley rats (n=8 to 12/group) received angiotensin II (120 ng/kg per minute, subcutaneously) for 14 days +/- spironolactone or hydralazine (25 mg/kg per day). An additional group received aldosterone (750 ng/h, subcutaneously) +/- spironolactone. Systolic blood pressure was increased by angiotensin II (P<0.001) and reduced by spironolactone and hydralazine (P<0.001). Aldosterone-induced increase of blood pressure was reduced by spironolactone (P<0.05). In mesenteric small arteries studied on a pressurized myograph, media/lumen ratio was increased (P<0.001) and acetylcholine-mediated relaxation was impaired in angiotensin II-infused rats (P<0.001); both were partially improved by spironolactone (P<0.05) but not by hydralazine. Aldosterone-induced increase of media/lumen ratio (P<0.001) and impaired response to acetylcholine (P<0.001) were normalized by spironolactone. Response to sodium nitroprusside was similar in all groups. Aortic NADPH oxidase activity was increased (P<0.01) by angiotensin II and reduced by spironolactone and hydralazine. Aldosterone also increased (P<0.05) activation of NADPH oxidase, an effect abolished by spironolactone. Plasma thiobarbituric acid-reactive substances (a marker of oxidative stress), higher in angiotensin II and aldosterone rats (P<0.001), were normalized by spironolactone. In conclusion, spironolactone, which inhibited aldosterone actions, partially corrected structural and functional angiotensin II-induced abnormalities. These effects were associated with reduced vascular NADPH oxidase activity and decreased plasma markers of oxidative stress. Our findings suggest that aldosterone may mediate some of angiotensin II-induced vascular effects in hypertension, in part via increased oxidative stress.
Publication
Journal: Nature
June/19/1985
Abstract
Connective tissue cells proliferate actively when cultured in the presence of serum. Platelet-derived growth factor (PDGF), a basic protein of relative molecular mass approximately 30,000, has been identified as the major serum mitogen for these cells; its main physiological/pathophysiological role may be to initiate wound healing in connection with tissue injury. However, growth of cultured cells is also influenced by several other factors, including epidermal growth factor, fibroblast growth factor, insulin and somatomedins. Furthermore, Rozengurt and Sinnett-Smith recently showed that bombesin, a neuroendocrine peptide isolated from frog skin, stimulates DNA synthesis and cell division in cultures of a specific subtype of 3T3 cells. Substance P and substance K (also known as neurokinin A or neuromedin L) are mammalian peptides belonging to the tachykinin family. Substance P has been studied extensively; it is distributed widely throughout the central and peripheral nervous system, including primary sensory neurones, and can be released in the periphery from axon collaterals of stimulated pain fibres and contribute to the inflammatory response. Substance K is a member of the tachykinin family isolated from mammalian spinal cord; Nawa et al. determined the primary structure of two types of substance P precursors, one of which contained a sequence homologous to substance K, as well as the sequence of substance P. We report here that substance P and substance K stimulate DNA synthesis in cultured arterial smooth muscle cells and human skin fibroblasts, and that this stimulation is inhibited by the substance P-antagonist spantide.
Publication
Journal: Neuroscience
April/8/1998
Abstract
In situ hybridization was combined with FluoroGold retrograde labelling to determine the distribution of messenger RNAs for the D1 dopamine receptor, D2 dopamine receptor, beta-preprotachykinin or preproenkephalin in the neurons projecting from the nucleus accumbens to the ventral pallidum and the ventral tegmental area. Neurons were quantified in both the core and the shell of the nucleus accumbens to estimate the proportion of neurons projecting to the ventral pallidum or ventral tegmental area that contain transcripts for D1 receptors, D2 receptors, beta-preprotachykinin or preproenkephalin. Following the deposition of FluoroGold into the central ventral pallidum, both the core and the shell of the nucleus accumbens were retrogradely labelled, while deposits into the ventral tegmental area selectively labelled cells in the shell. A high percentage of nucleus accumbens neurons innervating the ventral tegmental area expressed messenger RNAs for D1 receptors (72%) and beta-preprotachykinin (62%), while less than 3% of the neurons contained messenger RNAs for preproenkephalin or D2 receptors. The neurons projecting to the ventral pallidum did not show the discrete distribution of transcripts as was observed in the accumbens-ventral tegmental area projection. Preproenkephalin messenger RNA was identified in 46% of the neurons innervating the ventral pallidum, and D2 receptor messenger RNA was found in approximately 40% of the cells. A large minority of neurons projecting from the nucleus accumbens to the ventral pallidum also expressed messenger RNAs for D1 receptors (37%) and beta-preprotachykinin (35%). While a higher percentage of D1 receptor, and beta-preprotachykinin messenger RNA expressing cells were located in the shell than in the core of the nucleus accumbens, the percentage tended to be higher in the core for cells expressing D2 receptors or preproenkephalin messenger RNA. These data indicate that messenger RNAs for D2 receptors and enkephalin are selectively expressed in the accumbens-pallidal projection while transcripts encoding D1 receptors and substance P are contained in the efferent projections to both the ventral pallidum and ventral tegmental area. The presence of D1 receptor and beta-preprotachykinin messenger RNAs in both mesencephalic and pallidal projections contrasts output from the striatum where the expression of D1 receptor and beta-preprotachykinin messenger RNAs is primarily restricted to the mesencephalic projection.
Publication
Journal: Child Abuse and Neglect
March/25/2002
Abstract
OBJECTIVE
This study is a detailed examination of the association between parental alcohol abuse (mother only, father only, or both parents) and multiple forms of childhood abuse, neglect, and other household dysfunction, known as adverse childhood experiences (ACEs).
METHODS
A questionnaire about ACEs including child abuse, neglect, household dysfunction, and exposure to parental alcohol abuse was completed by 8629 adult HMO members to retrospectively assess the relationship of growing up with parental alcohol abuse to 10 ACEs and multiple ACEs (ACE score).
RESULTS
Compared to persons who grew up with no parental alcohol abuse, the adjusted odds ratio for each category of ACE was approximately 2 to 13 times higher if either the mother, father, or both parents abused alcohol (p < 0.05). For example, the likelihood of having a battered mother was increased 13-fold for men who grew up with both parents who abused alcohol (OR, 12.7; 95% CI: 8.4-19.1). For almost every ACE, those who grew up with both an alcohol-abusing mother and father had the highest likelihood of ACEs. The mean number of ACEs for persons with no parental alcohol abuse, father only, mother only, or both parents was 1.4, 2.6, 3.2, and 3.8, respectively (p < .001).
CONCLUSIONS
Although the retrospective reporting of these experiences cannot establish a causal association with certainty, exposure to parental alcohol abuse is highly associated with experiencing adverse childhood experiences. Improved coordination of adult and pediatric health care along with related social and substance abuse services may lead to earlier recognition, treatment, and prevention of both adult alcohol abuse and adverse childhood experiences, reducing the negative sequelae of ACEs in adolescents and adults.
Publication
Journal: American Journal of Physiology - Gastrointestinal and Liver Physiology
June/1/2009
Abstract
SOX transcription factors have the capacity to modulate stem/progenitor cell proliferation and differentiation in a dose-dependent manner. SOX9 is expressed in the small intestine epithelial stem cell zone. Therefore, we hypothesized that differential levels of SOX9 may exist, influencing proliferation and/or differentiation of the small intestine epithelium. Sox9 expression levels in the small intestine were investigated using a Sox9 enhanced green fluorescent protein (Sox9(EGFP)) transgenic mouse. Sox9(EGFP) levels correlate with endogenous SOX9 levels, which are expressed at two steady-state levels, termed Sox9(EGFPLO) and Sox9(EGFPHI). Crypt-based columnar cells are Sox9(EGFPLO) and demonstrate enriched expression of the stem cell marker, Lgr5. Sox9(EGFPHI) cells express chromogranin A and substance P but do not express Ki67 and neurogenin3, indicating that Sox9(EGFPHI) cells are postmitotic enteroendocrine cells. Overexpression of SOX9 in a crypt cell line stopped proliferation and induced morphological changes. These data support a bimodal role for SOX9 in the intestinal epithelium, where low SOX9 expression supports proliferative capacity, and high SOX9 expression suppresses proliferation.
Publication
Journal: Biochemical Journal
December/13/1984
Abstract
Endopeptidase-24.11 (EC 3.4.24.11), purified to homogeneity from pig kidney, was shown to hydrolyse a wide range of neuropeptides, including enkephalins, tachykinins, bradykinin, neurotensin, luliberin and cholecystokinin. The sites of hydrolysis of peptides were identified, indicating that the primary specificity is consistent with hydrolysis occurring at bonds involving the amino group of hydrophobic amino acid residues. Of the substrates tested, the amidated peptide substance P is hydrolysed the most efficiently (Km = 31.9 microM; kcat. = 5062 min-1). A free alpha-carboxy group at the C-terminus of a peptide substrate is therefore not essential for efficient hydrolysis by the endopeptidase. A large variation in kcat./Km values was observed among the peptide substrates studied, a finding that reflects a significant influence of amino acid residues, remote from the scissile bond, on the efficiency of hydrolysis. These subsite interactions between peptide substrate and enzyme thus confer some degree of functional specificity on the endopeptidase. The inhibition of endopeptidase-24.11 by several compounds was compared with that of pig kidney peptidyldipeptidase A (EC 3.4.15.1). Of the inhibitors examined, only N-[1(R,S)-carboxy-2-phenylethyl]-Phe-p-aminobenzoate inhibited endopeptidase-24.11 but not peptidyldipeptidase. Captopril (D-3-mercapto-2-methylpropanoyl-L-proline), Teprotide (pGlu-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro) and MK422 [N-[(S)-1-carboxy-3-phenylpropyl]-L-Ala-L-Pro] were highly selective as inhibitors of peptidyldipeptidase. Although not wholly specific, phosphoramidon was a more potent inhibitor of endopeptidase-24.11 than were any of the synthetic compounds tested.
Publication
Journal: Pharmacological Reviews
April/26/1995
Publication
Journal: Journal of Neuroscience
April/16/2003
Abstract
The transcription factor DeltaFosB accumulates in substance P-dynorphin-containing striatal neurons with repeated cocaine use. Here, we show that inducible transgenic DeltaFosB overexpression in this same striatal cell type facilitates acquisition of cocaine self-administration at low-threshold doses, consistent with increased sensitivity to the pharmacological effects of the drug. Importantly, DeltaFosB also enhances the degree of effort mice will exert to maintain self-administration of higher doses on a progressive ratio schedule of reinforcement, whereas levels of cocaine intake are not altered on less demanding fixed-ratio schedules. Acquisition and extinction of behavior reinforced by food pellets is not altered in DeltaFosB-overexpressing mice, indicating that DeltaFosB does not alter the capacity to learn an instrumental response or cause response perseveration in the absence of reinforcement. These data suggest that accumulation of DeltaFosB contributes to drug addiction by increasing the incentive properties of cocaine, an effect that could increase the risk for relapse long after cocaine use ceases.
Publication
Journal: General pharmacology
March/11/1998
Abstract
1. Primary afferent nerve fibers control cutaneous blood flow and vascular permeability by releasing vasoactive peptides. These vascular reactions and the additional recruitment of leukocytes are commonly embodied in the term neurogenic inflammation. 2. Calcitonin gene-related peptide (CGRP) acting via CGRPsubstance P (SP) and neurokinin A (NKA) acting via NK1 receptors mediate the increase in venular permeability. 3. Neurogenic vasodilatation and plasma protein leakage play a role in inflammation because many inflammatory and immune mediators including interleukin-1 beta, nitric oxide, prostanoids, protons, bradykinin, histamine, and 5-hydroxytryptamine can stimulate peptidergic afferent nerve fibers or enhance their excitability. 4. Neurogenic inflammatory reactions can be suppressed by alpha 2-adrenoceptor agonists, histamine acting via H1 receptors, 5-hydroxytryptamine acting via 5-HT1B receptors, opioid peptides, and somatostatin through prejunctional inhibition of peptide release from vasoactive afferent nerve fibers. CGRP, SP, and NKA receptor antagonists are powerful pharmacological tools to inhibit neurogenic inflammation at the postjunctional level. 5. Imbalance between the facilitatory and inhibitory influences on afferent nerve activity has a bearing on chronic inflammatory disease. Impaired nerve function represents a deficit in skin homeostasis while neuronal overactivity is a factor in allergic and hyperreactive disorders of the skin.
Authors
Publication
Journal: Archives of neurology
November/30/1998
Abstract
OBJECTIVE
To determine the effect of treatment with Ginkgo biloba extract on objective measures of cognitive function in patients with Alzheimer disease (AD) based on formal review of the current literature.
METHODS
An attempt was made to identify all English and non-English-language articles in which G. biloba extract was given to subjects with dementia or cognitive impairment. Inclusion criteria for the meta-analysis were (1) sufficiently characterized patients such that it was clearly stated there was a diagnosis of AD by either Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, or National Institute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, or there was enough clinical detail to determine this by our review; (2) clearly stated study exclusion criteria, ie, those studies that did not have stated exclusions for depression, other neurologic disease, and central nervous system-active medications were excluded; (3) use of standardized ginkgo extract in any stated dose; (4) randomized, placebo-controlled and double-blind study design; (5) at least 1 outcome measure was an objective assessment of cognitive function; and (6) sufficient statistical information to allow for meta-analysis.
RESULTS
Of more than 50 articles identified, the overwhelming majority did not meet inclusion criteria, primarily because of lack of clear diagnoses of dementia and AD. Only 4 studies met all inclusion criteria. In total there were 212 subjects in each of the placebo and ginkgo treatment groups. Overall there was a significant effect size of 0.40 (P<.0001). This modest effect size translated into a 3% difference in the Alzheimer Disease Assessment Scale-cognitive subtest.
CONCLUSIONS
Based on a quantitative analysis of the literature there is a small but significant effect of 3- to 6-month treatment with 120 to 240 mg of G. biloba extract on objective measures of cognitive function in AD. The drug has not had significant adverse effects in formal clinical trials but there are 2 case reports of bleeding complications. In AD, there are limited and inconsistent data that preclude determining if there are effects on noncognitive behavioral and functional measures as well as on clinician's global rating scales. Further research in the area will need to determine if there are functional improvements and to determine the best dosage. Additional research will be needed to define which ingredients in the ginkgo extract are producing its effect in individuals with AD.
Publication
Journal: Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
September/16/2010
Abstract
Childhood trauma is associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation and is a known risk factor for suicidal behavior. In this study we sought to determine whether the impact of childhood trauma on suicide risk might be modified by FKBPPA-axis regulating gene. Sixteen FKBPplotype-tagging single nucleotide polymorphisms (SNPs) were genotyped in a sample of African Americans: 398 treatment-seeking patients with substance dependence (90% men; 120 suicide attempters) and 432 nonsubstance-dependent individuals (40% men; 21 suicide attempters). In all, 474 participants (112 suicide attempters) also completed the Childhood Trauma Questionnaire (CTQ). Primary haplotype analyses were conducted with the four SNPs implicated in earlier studies: rs3800373, rs9296158, rs1360780, and rs9470080. We found that childhood trauma was associated with suicide attempt (P<0.0001). Although there was no main effect of the two major yin yang haplotypes in the four SNP haplotype blocks, there was a haplotype influence on suicide risk (p=0.006) only in individuals exposed to high levels of childhood trauma. In this group, 51% with two copies of the risk haplotype, 36% with one copy, and 20% with no copies had attempted suicide. The total logistic regression model accounted for 13% of the variance in attempted suicide. Analyses of the 16 SNPs showed significant main effects on suicide attempt of rs3777747, rs4713902, and rs9470080 and interactive effects of rs3800373, rs9296158, and rs1360780 with CTQ score on suicide attempt. These data suggest that childhood trauma and variants of the FKBPpting suicide.
Publication
Journal: Current Medicinal Chemistry
March/11/2007
Abstract
This review critically surveys the literature published mainly within this millennium on the new and emerging applications of silybin (pure, chemically defined substance) and silymarin (flavonoid complex from Silybum marianum - milk thistle seeds). These compounds used so far mostly as hepatoprotectants were shown to have other interesting activities, e.g. anticancer and canceroprotective and also hypocholesterolemic activity. These effects were demonstrated in a large variety of illnesses of different organs, e.g. prostate, lungs, CNS, kidneys, pancreas and also in the skin protection. Besides the cytoprotective activity of silybin mediated by its antioxidative and radical-scavenging properties also new functions based on the specific receptor interaction were discovered. These were studied on the molecular level and modulation of various cell-signaling pathways with silybin was disclosed--e.g. NF-kappaB, inhibition of EGFR-MAPK/ERK1/2 signaling, activity upon Rb and E2F proteins, IGF-receptor signaling. Proapoptotic activity of silybin in pre- and/or cancerogenic cells and anti-angiogenic activity of silybin are other important findings that bring silymarin preparations closer to respective application in the cancer treatment. Discovery of the inhibition and modulation of drug transporters, P-glycoproteins, estrogenic receptors, nuclear receptors by silybin and some of its new derivatives contribute further to the better understanding of silybin activity on the molecular level. Silymarin application in veterinary medicine is reviewed as well. Recent works using optically pure silybin diastereomers clearly indicate extreme importance of the use of optically active silybin namely in the receptor studies. Significance of silymarin and its components in the medicine is clearly indicated by an exponential growth of publications on this topic--over 800 papers in the last 5 years.
Publication
Journal: Toxicology and Industrial Health
May/24/1999
Abstract
Antiandrogenic chemicals alter sexual differentiation by a variety of mechanisms, and as a consequence, they induce different profiles of effects. For example, in utero treatment with the androgen receptor (AR) antagonist, flutamide, produces ventral prostate agenesis and testicular nondescent, while in contrast, finasteride, an inhibitor of 5 alpha-dihydrotestosterone (DHT) synthesis, rarely, if ever, induces such malformations. In this regard, it was recently proposed that dibutyl phthalate (DBP) alters reproductive development by a different mechanism of action than flutamide or vinclozolin (V), which are AR antagonists, because the male offsprings display an unusually high incidence of testicular and epididymal alterations--effects rarely seen after in utero flutamide or V treatment. In this study, we present original data describing the reproductive effects of 10 known or suspected anti-androgens, including a Leydig cell toxicant ethane dimethane sulphonate (EDS, 50 mg kg-1 day-1), linuron (L, 100 mg kg-1 day-1), p,p'-DDE (100 mg kg-1 day-1), ketoconazole (12-50 mg kg-1 day-1), procymidone (P, 100 mg kg-1 day-1), chlozolinate (100 mg kg-1 day-1), iprodione (100 mg kg-1 day-1), DBP (500 mg kg-1 day-1), diethylhexyl phthalate (DEHP, 750 mg kg-1 day-1), and polychlorinated biphenyl (PCB) congener no. 169 (single dose of 1.8 mg kg-1). Our analysis indicates that the chemicals discussed here can be clustered into three or four separate groups, based on the resulting profiles of reproductive effects. Vinclozolin, P, and DDE, known AR ligands, produce similar profiles of toxicity. However, p,p'-DDE is less potent in this regard. DBP and DEHP produce a profile distinct from the above AR ligands. Male offsprings display a higher incidence of epididymal and testicular lesions than generally seen with flutamide, P, or V even at high dosage levels. Linuron treatment induced a level of external effects consistent with its low affinity for AR [reduced anogenital distance (AGD), retained nipples, and a low incidence of hypospadias]. However, L treatment also induced an unanticipated degree of malformed epididymides and testis atrophy. In fact, the profile of effects induced by L was similar to that seen with DBP. These results suggest that L may display several mechanisms of endocrine toxicity, one of which involves AR binding. Chlozolinate and iprodione did not produce any signs of maternal or fetal endocrine toxicity at 100 mg kg-1 day-1. EDS produced severe maternal toxicity and a 45% reduction in size at birth, which resulted in the death of all neonates by 5 days of age. However, EDS only reduced AGD in male pups by 15%. Ketoconazole did not demasculinize or feminize males but rather displayed anti-hormonal activities, apparently by inhibiting ovarian hormone synthesis, which resulted in delayed delivery and whole litter loss. In summary, the above in vivo data suggest that the chemicals we studied alter male sexual differentiation via different mechanisms. The anti-androgens V, P, and p,p'-DDE produce flutamide-like profiles that are distinct from those seen with DBP, DEHP, and L. The effects of PCB 169 bear little resemblance to those of any known anti-androgen. Only in depth in vitro studies will reveal the degree to which one can rely upon in vivo studies, like those presented here, to predict the cellular and molecular mechanisms of developmental toxicity.
Publication
Journal: Current Opinion in Neurology
August/8/2010
Abstract
OBJECTIVE
Although a number of factors contribute to the high mortality and morbidity associated with traumatic brain injury (TBI), the development of cerebral edema with brain swelling remains the most significant predictor of outcome. The present review summarizes the most recent advances in the understanding of mechanisms associated with development of posttraumatic cerebral edema, and highlights areas of therapeutic promise.
RESULTS
Despite the predominance of cytotoxic (or cellular) edema in the first week after traumatic brain injury, brain swelling can only occur with addition of water to the cranial vault from the vasculature. As such, regulation of blood-brain barrier permeability has become a focus of recent research seeking to manage brain edema. Aquaporins, matrix metalloproteinases and vasoactive inflammatory agents have emerged as potential mediators of cerebral edema following traumatic brain injury. In particular, kinins (bradykinins) and tachykinins (substance P) seem to play an active physiological role in modulating blood-brain barrier permeability after trauma. Substance P neurokinin-1 receptor antagonists show particular promise as novel therapeutic agents.
CONCLUSIONS
Attenuating blood-brain barrier permeability has become a promising approach to managing brain edema and associated swelling given that increases in cranial water content can only be derived from the vasculature. Inflammation, both classical and neurogenic, offers a number of attractive targets.
Publication
Journal: Molecular Ecology
January/29/2013
Abstract
Many insects contain diverse gut microbial communities. While several studies have focused on a single or small group of species, comparative studies of phylogenetically diverse hosts can illuminate general patterns of host-microbiota associations. In this study, we tested the hypotheses that (i) host diet and (ii) host taxonomy structure intestinal bacterial community composition among insects. We used published 16S rRNA gene sequence data for 58 insect species in addition to four beetle species sampled from the Sevilleta National Wildlife Refuge to test these hypotheses. Overall, gut bacterial species richness in these insects was low. Decaying wood xylophagous insects harboured the richest bacterial gut flora (102.8 species level operational taxonomic units (OTUs)/sample ± 71.7, 11.8 ± 5.9 phylogenetic diversity (PD)/sample), while bees and wasps harboured the least rich bacterial communities (11.0 species level OTUs/sample ± 5.4, 2.6 ± 0.8 PD/sample). We found evidence to support our hypotheses that host diet and taxonomy structure insect gut bacterial communities (P < 0.001 for both). However, while host taxonomy was important in hymenopteran and termite gut community structure, diet was an important community structuring factor particularly for insect hosts that ingest lignocellulose-derived substances. Our analysis provides a baseline comparison of insect gut bacterial communities from which to test further hypotheses concerning proximate and ultimate causes of these associations.
Publication
Journal: Kidney International
June/18/2002
Abstract
BACKGROUND
In non-ESRD patients, recent studies have demonstrated that the process of vascular calcification resembles developmental osteogenesis. Patients with ESRD are known to have excessive vascular calcification, but this has previously been attributed to the non-cell-mediated process of metastatic calcification.
METHODS
To determine if the calcification observed in patients with ESRD is related to a cell-mediated process, we removed a piece of inferior epigastric artery at the time of renal transplant. Calcium content of the entire vessel was quantified with spiral computed tomography (CT). The vessel was then examined histologically for calcification and the presence of bone matrix proteins by immunohistochemistry, and medial and intimal thickness quantified by histomorphometry. These findings were correlated with demographic, clinical and laboratory values.
RESULTS
The proximal inferior epigastric artery was obtained from 41 patients undergoing renal transplantation, but two were inadequate for histologic examination. Twenty-seven of the remaining vessels had no evidence of calcification by MacNeal's or Alizarin red pH 4.2 staining, five vessels had mild/moderate calcification, and seven had severe calcification, all in the medial layer. Calcification assessed histologically was closely correlated with calcification score as assessed by spiral CT, normalized for vessel weight (P=0.027). Positive immunostaining for the bone matrix proteins osteopontin, type I collagen, bone sialoprotein, and alkaline phosphatase was strongly correlated with calcification (all P < or = 0.001), as was a history of coronary artery disease (P < 0.001), and diabetes (P=0.034). The calcification score by spiral CT correlated with these same factors and the serum phosphorus and calcium x phosphorus product (P=0.032 and 0.037). The location of immunostaining for the bone proteins was strongly associated with the presence of calcification. However, positive immunostaining also was observed in association with disorganization of the vascular smooth muscle cells in the medial layer due to deposition of a matrix-like substance, prior to overt calcification.
CONCLUSIONS
In patients with ESRD undergoing renal transplantation, vascular calcification of the medial layer of the inferior epigastric artery is common (44%), can be detected by spiral CT, and is associated with deposition of bone matrix proteins. This implies an active cell-mediated process, raising hope that directed intervention can arrest this process.
Publication
Journal: Science
July/12/1995
Abstract
In vivo somatosensory stimuli evoked the release of substance P from primary afferent neurons that terminate in the spinal cord and stimulated endocytosis of substance P receptors in rat spinal cord neurons. The distal dendrites that showed substance P receptor internalization underwent morphological reorganization, changing from a tubular structure to one characterized by swollen varicosities connected by thin segments. This internalization and dendritic structural reorganization provided a specific image of neurons activated by substance P. Thus receptor internalization can drive reversible structural changes in central nervous system neurons in vivo. Both of these processes may be involved in neuronal plasticity.
Publication
Journal: Pain
September/28/1997
Abstract
Subcutaneous (s.c.) injection of formalin induces a rapid and prolonged hyperalgesia across widespread areas of the body. This hyperalgesic state involves a brain-to-spinal cord pathway, likely arising from the nucleus raphe magnus. The present study examined whether subsequent activation of spinal cord glia may be critical for the hyperalgesic state to be observed in rats. Glia were considered candidates as they can, upon activation, release a variety of substances known to be critical for the mediation of subcutaneous formalin-induced hyperalgesia including glutamate, aspartate, nitric oxide, arachidonic acid and cyclooxygenase products such as prostaglandins. This series of experiments demonstrate that formalin-induced hyperalgesia in rats can be blocked by intrathecal administration of agents that: (a) disrupt glial function (using either 1 nmol fluorocitrate which is a glial metabolic inhibitor, or 9 microg CNI-1493 which disrupts synthesis of nitric oxide and cytokines in monocyte-derived cells; ANOVA revealed reliable group effects for each drug with P < 0.0005); or (b) disrupt the action of glial products (using 10, 50, or 100 microg of a human recombinant interleukin-1 receptor antagonist or 10 microl antibody directed against nerve growth factor; ANOVA revealed reliable group effects for each drug with P < 0.001). Disruption appeared to be selective, as blockade of only select glial products was effective. That is, up to 120 microg of a functional antagonist of tumor necrosis factor-alpha (TNF binding protein) and 5 microl of an antibody against complement-3 produced no statistically reliable reduction in formalin-induced hyperalgesia. Taken together, the present series of experiments suggest an important role for spinal glial cells in the cascade of events that are initiated by descending signals following s.c. administration of formalin.
Publication
Journal: Annals of Neurology
January/26/1984
Abstract
The prevalence of severe dementia in the United States is about 1.3 million cases, of which at least 50 to 60% are of the Alzheimer type. Severe dementia of the Alzheimer type is found rarely in a clearly dominant pattern, although often one or more relatives are affected. Down's syndrome in adults is often associated with Alzheimer changes. The diagnosis is a clinicopathological one; there is a considerable error rate in the clinical diagnosis early in the course of the disease, especially in regard to dementia in depression. The differential diagnosis involves a great many disorders, including multi-infarct dementia, tumors, subdural hematomas, and others. Physiological aspects of Alzheimer's disease include a diffusely slow electroencephalogram, reduced cerebral blood flow, and particular patterns noted on positron emission tomographic scanning. The latter technique has also demonstrated that oxygen extraction is normal in Alzheimer's disease, thus excluding ischemia from possible pathogenetic factors. Morphological changes, that is, the presence of plaques and tangles, are widely distributed in neocortex, paleocortex, and many deep gray areas down through the pontine tegmentum, but largely exclude the basal ganglia, thalamus, and substantia nigra. Numerous plaques without neocortical tangles are found in many demented persons older than 75 years. A severe loss of large neocortical neurons is characteristic of the disease. The chemical nature of the paired helical filaments that make up the neurofibrillary tangle has not yet been ascertained. Neurons are markedly deficient in the basal forebrain nuclei, and this deficiency may account for the severe diminution of choline acetyltransferase and acetylcholine in the neocortex and paleocortex. Muscarinic cholinergic receptors are present in normal amounts. Norepinephrine is reduced in some cases, and somatostatin in most. Substance P is low in severe cases. The etiology of the disorder is unknown and the role of aluminum is disputed. Management of patients with Alzheimer's disease is difficult, and neuroleptics are to be used with great caution because of their side effects. Substrate therapy has not been effective; physostigmine improves memory but is not suitable for general use. Trophic factors, gangliosides, and aluminum chelation are being investigated for use in pharmacological intervention.
Publication
Journal: Immunology
March/26/2008
Abstract
During neuronal-induced inflammation, mast cells may respond to stimuli such as neuropeptides in an FcepsilonRI-independent manner. In this study, we characterized human mast cell responses to substance P (SP), nerve growth factor (NGF), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) and compared these responses to human mast cell responses to immunoglobulin E (IgE)/anti-IgE and compound 48/80. Primary cultured mast cells, generated from CD34(+) progenitors in the presence of stem cell factor and interleukin-6 (IL-6), and human cultured mast cells (LAD2) were stimulated with these and other stimuli (gastrin, concanavalin A, radiocontrast media, and mannitol) and their degranulation and chemokine production was assessed. VIP and SP stimulated primary human mast cells and LAD cells to degranulate; gastrin, concanavalin A, radiocontrast media, mannitol, CGRP and NGF did not activate degranulation. While anti-IgE stimulation did not induce significant production of chemokines, stimulation with VIP, SP or compound 48/80 potently induced production of monocyte chemoattractant protein-1, inducible protein-10, monokine induced by interferon-gamma (MIG), RANTES (regulated on activation, normal, T-cell expressed, and secreted) and IL-8. VIP, SP and compound 48/80 also activated release of tumour necrosis factor, IL-3 and granulocyte-macrophage colony-stimulating factor, but not IL-4, interferon-gamma or eotaxin. Human mast cells expressed surface neurokinin 1 receptor (NK1R), NK2R, NK3R and VIP receptor type 2 (VPAC2) but not VPAC1 and activation of human mast cells by IgE/anti-IgE up-regulated expression of VPAC2, NK2R, and NK3R. These studies demonstrate the pattern of receptor expression and activation of mast cell by a host of G-protein coupled receptor ligands and suggest that SP and VIP activate a unique signalling pathway in human mast cells. These results are likely to have direct relevance to neuronally induced inflammatory diseases.
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