The analgesic and anti-inflammatory effects of Salvinorin A analogue ß-tetrahydropyran Salvinorin B in mice.

BACKGROUND: Drugs activating the mu opioid receptor are routinely used to treat severe acute and chronic pain. Unfortunately, side effects including nausea, constipation, respiratory depression, addiction and tolerance can limit clinical utility. In contrast, kappa opioid receptor (KOPr) agonists, such as Salvinorin A (SalA), have analgesic properties with little potential for abuse. METHODS: We evaluated SalA and the novel analogue ß-tetrahydropyran Salvinorin B (ß-THP SalB) for the ability to modulate pain and inflammation in vivo. The hot water tail-withdrawal assay, intradermal formalin-induced inflammatory pain and paclitaxel-induced neuropathic pain models were used to evaluate analgesic properties in mice. Tissue infiltration of inflammatory cells was measured by histology and flow cytometry. RESULTS: ß-tetrahydropyran Salvinorin B produced a longer duration of action in the tail-withdrawal assay compared to the parent compound SalA, and, like SalA and U50,488, ß-THP SalB is a full agonist at the KOPr. In the formalin-induced inflammatory pain model, ß-THP SalB and SalA significantly reduced pain score, paw oedema and limited the infiltration of neutrophils into the inflamed tissue. ß-THP SalB and SalA supressed both mechanical and cold allodynia in the paclitaxel-induced neuropathic pain model, in a dose-dependent manner. CONCLUSIONS: Structural modification of SalA at the C-2 position alters its analgesic potency and efficacy in vivo. Substitution with a tetrahydropyran group at C-2 produced potent analgesic and anti-inflammatory effects, including a reduction in paclitaxel-induced neuropathic pain. This study highlights the potential for KOPr agonists as analgesics with anti-inflammatory action and little risk of abuse. SIGNIFICANCE: Salvinorin A and the novel analogue ß-THP Salvinorin B show analgesic effects in the tail-withdrawal and formalin assays. They reduce oedema and decrease neutrophil infiltration into inflamed tissue, and suppress mechanical and cold allodynia in paclitaxel-induced neuropathic pain.

Formative evaluation of ontology learning methods for entity discovery by using existing ontologies as reference standards.

OBJECTIVE: Developing a two-step method for formative evaluation of statistical Ontology Learning (OL) algorithms that leverages existing biomedical ontologies as reference standards. METHODS: In the first step optimum parameters are established. A 'gap list' of entities is generated by finding the set of entities present in a later version of the ontology that are not present in an earlier version of the ontology. A named entity recognition system is used to identify entities in a corpus of biomedical documents that are present in the 'gap list', generating a reference standard. The output of the algorithm (new entity candidates), produced by statistical methods, is subsequently compared against this reference standard. An OL method that performs perfectly will be able to learn all of the terms in this reference standard. Using evaluation metrics and precision-recall curves for different thresholds and parameters, we compute the optimum parameters for each method. In the second step, human judges with expertise in ontology development evaluate each candidate suggested by the algorithm configured with the optimum parameters previously established. These judgments are used to compute two performance metrics developed from our previous work: Entity Suggestion Rate (ESR) and Entity Acceptance Rate (EAR). RESULTS: Using this method, we evaluated two statistical OL methods for OL in two medical domains. For the pathology domain, we obtained 49% ESR, 28% EAR with the Lin method and 52% ESR, 39% EAR with the Church method. For the radiology domain, we obtain 87% ESA, 9% EAR using Lin method and 96% ESR, 16% EAR using Church method. CONCLUSION: This method is sufficiently general and flexible enough to permit comparison of any OL method for a specific corpus and ontology of interest.

Effectiveness of lexico-syntactic pattern matching for ontology enrichment with clinical documents.

OBJECTIVE: To evaluate the effectiveness of a lexico-syntactic pattern (LSP) matching method for ontology enrichment using clinical documents. METHODS: Two domains were separately studied using the same methodology. We used radiology documents to enrich RadLex and pathology documents to enrich National Cancer Institute Thesaurus (NCIT). Several known LSPs were used for semantic knowledge extraction. We first retrieved all sentences that contained LSPs across two large clinical repositories, and examined the frequency of the LSPs. From this set, we randomly sampled LSP instances which were examined by human judges. We used a two-step method to determine the utility of these patterns for enrichment. In the first step, domain experts annotated medically meaningful terms (MMTs) from each sentence within the LSP. In the second step, RadLex and NCIT curators evaluated how many of these MMTs could be added to the resource. To quantify the utility of this LSP method, we defined two evaluation metrics: suggestion rate (SR) and acceptance rate (AR). We used these measures to estimate the yield of concepts and relationships, for each of the two domains. RESULTS: For NCIT, the concept SR was 24%, and the relationship SR was 65%. The concept AR was 21%, and the relationship AR was 14%. For RadLex, the concept SR was 37%, and the relationship SR was 55%. The concept AR was 11%, and the relationship AR was 44%. CONCLUSION: The LSP matching method is an effective method for concept and concept relationship discovery in biomedical domains.

Development of visual diagnostic expertise in pathology.

In this study, we use methods from information-processing to explore the visual diagnostic processes of novice, intermediate, and expert pathologists. Subjects were asked to examine and interpret a set of slides while we collected think-aloud verbal protocols and captured on digital video the actual visual data they examined from the microscope. We performed an in-depth combined video and protocol-based analysis of processes and errors occurring as the task was performed. Additionally, we collected measures of accuracy, certainty, and difficulty for all cases. Our preliminary analysis identified significant differences between groups in all three major aspects of this task: searching skills, perceptual skills and cognitive/reasoning skills. We describe the implications of our preliminary cognitive task analysis on the design of a developing intelligent educational system in Pathology.

Defining the role of anatomic pathology images in the multimedia electronic medical record--a preliminary report.

The development of the Multimedia Electronic Medical Record System (MEMRS) offers new opportunities for integrating medical imaging data with text-based clinical data. The effective integration of pathology images into the patient's medical record poses some significant technical and organizational challenges. Before these challenges can be met, it is imperative that we investigate the value and utility of providing these images to clinicians. In this study we examined attitudes towards use of pathology images in Image Engine, a MEMRS under development at the University of Pittsburgh Cancer Institute (UPCI). We conducted semi-structured standardized interviews with a cohort of practicing oncologists, all of whom had significant experience with Image Engine. This study is a first step towards elucidating the potential barriers, uses, and value of anatomic pathology images in the MEMRS.

Overexpression of copper/zinc superoxide dismutase: a novel cause of murine muscular dystrophy.

Oxidative injury underlies the cellular injury and cell death in a variety of disease states. In muscular dystrophies, evidence from in vivo and in vitro studies suggests that muscle degeneration may be secondary to an increased susceptibility to oxidative stress. To address the role of free radical metabolism in the pathogenetic process of muscular dystrophies, we examined the muscle of transgenic mice that overexpress copper/zinc (Cu/Zn) superoxide dismutase. Overexpression of this enzyme can sensitize cells to oxidative injury, and Cu/Zn superoxide dismutase activity was elevated approximately fourfold above control levels in skeletal muscle of the transgenic strain. Examination of serum creatine phosphokinase levels in these mice revealed significant elevations after 2 months of age, indicative of active muscle breakdown. By 8 months of age, there was gross atrophy of the quadriceps muscle, and other hindlimb muscles were variably affected. Histologically, there was evidence of widespread muscle necrosis and regeneration, fiber splitting, and replacement of muscle with adipose and fibrous connective tissue, typical of a muscular dystrophy. Associated with the development of this degeneration was an increase in the levels of lipid peroxidation in the muscle of Cu/Zn superoxide dismutase transgenic mice, highlighting the central role of oxidative injury in this pathogenetic process. These results demonstrate that oxidative damage can be the primary pathogenetic process underlying a muscular dystrophy.

Scedosporium apiospermum (Pseudallescheria boydii) infection in a heart transplant recipient: a case of mistaken identity.

We report a case of fatal central nervous system infection with Scedosporium apiospermum (Pseudallescheria boydii) in a heart transplant recipient. This ubiquitous fungus is known to cause mycetoma and localized infections in patients with otherwise normal conditions. Disseminated infections occur rarely and are seen primarily in patients who are receiving immunosuppressive medications or who have neutropenia. Often life-threatening when infection is disseminated and involves the central nervous system, this diagnosis is difficult to make rapidly because S. apiospermum (P. boydii) mimics Aspergillus spp. and Fusarium spp., both clinically and histopathologically. Imidazoles such as miconazole, but not amphotericin B, are considered the therapeutic compounds of choice. Improved diagnostic and treatment options are needed to optimize management of infections with S. apiospermum (P. boydii).

Coexistence of occult vascular malformations and developmental venous anomalies in the central nervous system: MR evaluation.

PURPOSE: We sought to determine the prevalence of coexistent occult vascular malformations (OVMs) and developmental venous anomalies (DVAs) and to investigate the relationship between them. METHODS: One hundred two patients with OVMs were examined with precontrast and postcontrast T1-weighted MR imaging and with noncontrast T2-weighted MR imaging. Seventy-two patients had surgery, with subsequent pathologic confirmation of the final diagnosis. RESULTS: Coexistent DVAs and OVMs were present in 23 (23%) of 102 patients. Seventy-nine patients had OVMs without DVAs, and in this population, multiple OVMs (from two to 10 or more) were seen in 13 patients (16%). In contrast, multiple OVMs were seen in 10 (43%) of 23 patients with coexisting OVMs and DVAs. Twenty-five (83%) of 30 OVMs coexisting with DVAs were infratentorial. In 72 patients with surgically resected OVMs, 49 (68%) had pathologically confirmed cavernous malformations. Among the patients with coexistent DVAs, seven (46%) had cavernous malformations, four (27%) had thrombosed arteriovenous malformations, and four (27%) had vascular malformations that were not classifiable. CONCLUSION: Our study revealed a high prevalence of OVMs with coexistent DVAs, and a high percentage of these were in the posterior fossa. Contrast-enhanced MR imaging may increase the probability of finding these lesions, and therefore should be considered part of the preoperative evaluation, since the finding of unexpected coexistent lesions may affect surgical management.

Concentrations of leptin in the serum of pregnant, lactating, and cycling rats and of leptin messenger ribonucleic acid in rat placental tissue.

Leptin concentrations were measured in the serum of cycling, pregnant, and lactating Sprague-Dawley rats. Serum leptin concentrations did not vary significantly during the estrous cycle. In contrast, as gestation advanced, serum leptin concentrations increased significantly, p < 0.0001. Following delivery, leptin concentrations declined and remained stable during lactation. Leptin messenger ribonucleic acid (mRNA) was identified in the visceral adipose tissue and placenta of rats sacrificed on days 14 and 21 of pregnancy. The relative abundance of placental leptin mRNA increased approximately 4 to 5 fold from day 14 to 21 of gestation. The pattern of elevated leptin concentrations in the serum of late pregnant rats is similar to that reported in pregnant women, therefore the rat may be a useful model for the study of leptin during pregnancy. The increase in leptin in the serum of late pregnant rats, as well as an increase in placental mRNA, raises the possibility that leptin may serve a physiological role for the late parturient rat and/or its young.

Mixed arteriovenous malformation and capillary telangiectasia: a rare subset of mixed vascular malformations. Case report.

In this report, the authors discuss the case of a patient with a mixed cerebrovascular malformation in which an arteriovenous malformation (AVM) was associated with a capillary telangiectasia. Recent reports have contained reviews of various subsets of mixed malformations. To the authors' knowledge, however, this is the first report of a mixed vascular malformation with both arterial and capillary components. The patient underwent complete resection of the AVM after presenting with a clinical hemorrhage. She required a second operation to resect the capillary telangiectasia after new symptoms developed several months following the first procedure. The authors conclude that a mixed AVM-capillary telangiectasia is a rare but distinct entity.

Isolated meningeal vasculopathy associated with Clostridium septicum infection.

A 28-year-old patient with acute lymphoblastic leukemia and neutropenia developed necrotizing enterocolitis and Clostridium septicum bacteremia, followed by rhabdomyolysis, skin rash, and acute neurologic changes. Numerous cortical leptomeningeal enhancements were present on head MRI. Meningeal and brain biopsy showed segmental, full-thickness lysis of smooth muscle cells of medium-sized meningeal vessels with overall preservation of the structure of the vessel wall.

Effect of progesterone on hypothalamic oxytocin messenger ribonucleic acid levels in the lactating rat.

We recently reported that sequential administration of estrogen and progesterone and subsequent withdrawal of progesterone increased the level of hypothalamic oxytocin (OT) messenger RNA (mRNA) in the female rat. Both estrogen priming and progesterone withdrawal are critical components of this regimen. Rats experience this ovarian steroid pattern during certain lactational events such as on days 10-12 of lactation or with interruption of nursing for 48-72 h. In the present study, we used Northern blot and in situ hybridization to determine the association between the steroid exposure and the level of OT mRNA during these lactational conditions. Week 1 lactating rats that had pups removed for 24 and 48 h, but not 12 h, had significantly higher serum estradiol concentrations than animals continuously nursing their pups on a comparable day of lactation (F4, 15 = 6; P < 0.005). Serum progesterone levels declined significantly during the 48 h after litter removal (F4, 15 = 130.5; P < 0.0001). Significant increases in OT mRNA levels were found at 48 h, but not 12 or 24 h, after litter removal (F4, 15 = 4.3; P < 0.02). Implantation of progesterone-filled capsules to compensate for the spontaneous decline in progesterone that occurs with interruption of nursing attenuated this increase in OT mRNA levels. OT mRNA was significantly higher in the hypothalamic paraventricular nuclei (P < 0.0002) and supraoptic nuclei (P < 0.002) of nursing interrupted animals receiving empty vs. progesterone-filled implants. Implantation of day 12 lactating rats with progesterone capsules for 5 days before being killed blunted the increase in OT mRNA that normally occurs on this day of lactation. The data highlight the pivotal role of estrogen priming and progesterone withdrawal in the increased expression of the OT gene during select lactational events.

Effect of testosterone and its metabolites upon the level of vasopressin messenger ribonucleic acid in the hypothalamus of the hyperosmotically stimulated male rat.

We previously reported that gonadal steroids modify the expression of arginine vasopressin (AVP) in the hypothalamus of rats administered 2% sodium chloride solution for 5 days. Gonadectomy prevented, and testosterone (T) replacement restored, enhanced AVP mRNA levels in the supraoptic nucleus (SON) of male rats receiving this hyperosmotic challenge. The present study investigated the effects of the androgenic and estrogenic metabolites of T on hypothalamic AVP mRNA levels in response to chronic hyperosmolality. Gonadectomized male rats receiving 2% NaCl for 5 days and treated with T, dihydrotestosterone (DHT), or DHT+estradiol (E2), but not E2 alone or empty implants, had increased AVP mRNA levels compared to gonadectomized animals receiving tap water. Our results support a role for T and DHT-mediated effects upon the enhanced accumulation of AVP mRNA in the SON of male rats receiving a chronic hyperosmotic challenge.

Increased accumulation of oxytocin messenger ribonucleic acid in the hypothalamus of the female rat: induction by long term estradiol and progesterone administration and subsequent progesterone withdrawal.

To examine a possible role for gonadal steroid hormones in the enhanced accumulation of hypothalamic oxytocin (OT) messenger RNA (mRNA) and peptide in late pregnancy, we used an established model (22) in which sequential administration of estradiol (E2) and progesterone (P) SILASTIC capsules to ovariectomized rats is followed by removal of P. Long term and sustained E2 combined with abrupt P withdrawal mimics the gonadal steroid hormone pattern of late gestation in the rat (22). Using this paradigm, we demonstrate that OT mRNA is increased in the rat hypothalamus after long term P treatment, but only in the presence of E2 and only when P capsules are removed 48 h before killing. Furthermore, we show that P replacement in primiparous rats during late pregnancy blunts the increase in OT mRNA normally observed at the end of gestation. Our results support a role for E2 priming and P withdrawal in the enhanced accumulation of OT mRNA in the hypothalamus of the female rat.

Effect of gonadal steroids upon hypothalamic oxytocin expression.

Oxytocin (OT) has been implicated in reproductive events. Gonadal steroids, which are also essential for reproduction, may in these instances influence the expression of the OT gene. The relationship between gonadal steroids and OT expression is incompletely understood. First, although estrogen (E) induces OT expression in heterologous in vitro systems and the OT gene contains an estrogen response element, evidence for a stimulatory effect of E upon OT mRNA in vivo as in the rat hypothalamus has been lacking. Second, an enhanced and coordinated expression of OT and vasopressin (AVP), mRNA during late pregnancy and lactation is not expected. This is especially true in lactation, during which suckling selectively activates OT, not AVP, neurons. We now report that E does increase OT mRNA levels in the rat hypothalamus. Ovariectomized rats were implanted initially with E, followed by progesterone (P) 48 hrs later; both were sustained for 12 days and the P implants were removed 48 hrs prior to sacrifice. By in situ and Northern blot hybridizations, OT, but not AVP, mRNA was increased in the hypothalamus of animals receiving this regimen compared to sham treated cohorts. A similar phenomenon associated with exposure to E and P followed by P withdrawal occurs in physiologic states such as day 21 of pregnancy, day 10-12 of lactation, and with interruption of the suckling stimulus for 48 hrs. If E was not administered or if P was not withdrawn prior to sacrifice, no increase was found in OT mRNA. Our data highlight the pivotal role of P withdrawal in the induction of the hypothalamic OT gene in the E-primed rat.

Gonadal steroid modulation of oxytocin and vasopressin gene expression in the hypothalamus of the osmotically stimulated rat.

We investigated the modulatory role of gonadal steroids on the expression of oxytocin (OT) and vasopressin (AVP) cytoplasmic mRNAs in the paraventricular nucleus and supraoptic nucleus of the osmotically stimulated rat. We chronically administered an oral salt load (2% sodium chloride solution for 5 days) to intact and gonadectomized female and male Sprague-Dawley rats and measured serum sodium, body weight, pituitary content of OT and AVP immunoreactivities, and size and abundance of hypothalamic cytoplasmic OT and AVP mRNA transcripts. Intact and gonadectomized rats that were administered an osmotic challenge developed comparable degrees of hypernatremia and loss of body weight as well as depletion of posterior pituitary stores of OT and AVP. Hyperosmolality induced elongation of the OT and AVP transcripts in intact and gonadectomized animals, but only intact rats had enhanced hypothalamic cytoplasmic OT and AVP mRNA concentrations to this stimulus. Replacement with gonadal steroids restored the up-regulation in OT and AVP gene expression in gonadectomized animals rendered hyperosmolar. The findings support a modulatory role for gonadal steroids in hypothalamic OT and AVP gene expression during osmotic stimulation.

Cytoplasmic oxytocin and vasopressin gene transcripts decline postpartum in the hypothalamus of the lactating rat.

Oxytocin (OT) and vasopressin (AVP) gene expression are enhanced in the rat hypothalamus in late gestation and during the second and third weeks of lactation. We report that during the first 3 postpartum days, OT and AVP cytoplasmic mRNAs in the supraoptic and paraventricular nuclei of lactating rats decreased dramatically, reaching less than one fifth of peak gestational levels by day 2 postpartum. Differences in the temporal pattern of OT and AVP expression were observed in the supraoptic and paraventricular nuclei from days 4-10 of lactation. We also compared OT and AVP cytoplasmic mRNAs isolated from the hypothalamus of day 3 lactating rats to cohorts that had litters removed at the time of parturition. Lactating rats had significantly lower OT and AVP cytoplasmic mRNA levels than their nonlactating cohorts. We further compared OT and AVP cytoplasmic mRNAs in the hypothalamus of day 12 lactating rats that had been ovariectomized or sham ovariectomized on day 3 of lactation. Ovariectomized day 12 lactating animals had significantly lower OT and AVP cytoplasmic mRNA levels than their intact cohorts. These data refute the hypothesis that lactation is characterized by persistently elevated hypothalamic cytoplasmic OT and AVP mRNAs produced as a result of continuous stimulation by suckling and suggest that ovarian steroids may exert a modulatory effect on hypothalamic OT and AVP expression during early lactation.

Endothelin-1 gene expression in human pheochromocytoma.

We examined expression of human endothelin-1 (ET-1) in adrenal tissues removed from five patients with pheochromocytomas and two patients with aldosterone-producing adenomas. The pheochromocytomas contained a 2.3 kilobase ET-1 transcript, which was not found int he aldosteronomas. Constitutive expression of ET-1 varied in magnitude among the pheochromocytomas but was generally at a low level. Immunohistochemical staining of the pheochromocytomas with an antiserum to human ET-1 showed the presence of immunoreactive ET-1 as well. The presence of ET-1 messenger ribonucleic acid and ET-1 immunoreactivity in human pheochromocytomas suggests a possible paracrine role for this peptide in human chromaffin cells.