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[Acrocyanosis: changing concepts and nosological limitations].

Acrocyanosis is undoubtedly the most commonplace acrosyndrome, both in terms of pathogenesis and prognosis. Patients experience functional impairment and an esthetic prejudice that must not be neglected. Adopting the nosological classifications described for Raynaud's syndrome, primary acrocyanosis must be distinguished from exceptional secondary phenomena that have a radically different clinical course. Primary acrocyanosis is generally observed in a young woman who appears thin or has recently lost weight. No paroxysmal episode (syncope, cyanosis, suspicious event involving the fingers) is found. The physical examination is negative and no complementary explorations are needed. Current pathophysiological hypotheses remain insufficient but suggest that vasospasticity rather than hemorheology is involved. The hypothesis that a thermoregulation disorder could be associated with weight loss deserves further study. Symptomatic care relies on dietary and hygiene counseling, emphasizing the importance of warm clothing. The psychological element must also be considered even in the most common forms.

Adult↗

SMAD3 represses androgen receptor-mediated transcription.

The androgen-signaling pathway is important in the growth and progression of prostate cancer. Androgen ablation therapy, which may result in programmed cell death, is often used to treat advanced prostate cancer. The growth-promoting effects of androgen are mediated mostly through the androgen receptor (AR). Transforming growth factor beta (TGF-beta) plays critical roles in controlling prostate cell proliferation, differentiation, and apoptosis. Normal transcripts and proteins of TGF-beta receptors are frequently lost in prostate cancer cells, especially in advanced stages of the disease. However, the mechanisms by which TGF-beta inhibits proliferation and induces apoptosis in prostate cancer cells is not clear. We investigated the molecular mechanism by which TGF-beta inhibits transcriptional activation mediated by AR. Using transient transfection systems, we demonstrated that Smad3 specifically represses transcriptional activation mediated by AR on two natural androgen-responsive promoters. This repression is transmitted through TGF-beta signaling and can be regulated by other Smad proteins. A protein-protein interaction between AR and Smad3 was identified in vitro and in vivo, and the transcription activation domain of AR and the MH2 of Smad3 were identified as being responsible for binding. Additional functional experiments showed that the repression of AR by Smad3 is mediated solely through the MH2 domain. These results provide fresh insight for understanding the mechanism by which TGF-beta regulates the androgen-signaling pathway in prostate cancer cells.

Androgen Receptor Antagonists↗

[Vertebral osteoblastoma and scoliosis. Two cases report].

We report two cases of spinal osteoblastoma in two boys aged 16 and 19 years. The lesion was disclosed by scoliosis with signs of thoracic and lumbar neurological compression. The diagnosis was provided by the CT scan and magnetic resonance imaging and was confirmed by the histology study of the surgical specimen. Involvement of the vertebral column has been estimated to range from 30 to 40% for these rare tumors that account for less than 1% of all bone tumors. Localization on the convex aspect of scoliosis is rare. CT-scan provides an analysis of the tumor components and clearly demonstrates intraspinal extension. MRI is superior in visualizing neurological compression. In our experience, function outcome has been favorable after surgical decompression.

Adolescent↗

Fox (forkhead) genes are involved in the dorso-ventral patterning of the Xenopus mesoderm.

Fox (forkhead/winged helix) genes encode a family of transcription factors that are involved in embryonic pattern formation, regulation of tissue specific gene expression and tumorigenesis. Several of them are transcribed during Xenopus embryogenesis and are important for the patterning of ectoderm, mesoderm and endoderm. We have isolated three forkhead genes that are activated during gastrulation and play an important role in the dorso-ventral patterning of the mesoderm. XFKH1 (FoxA4b), the first vertebrate forkhead gene to be implicated in embryonic pattern formation, is expressed in the Spemann-Mangold organizer region and later in the embryonic notochord. XFKH7, the Xenopus orthologue of the murine Mfh1(Foxc2), is expressed in the presomitic mesoderm, but not in the notochord or lateral plate mesoderm. Finally, XFD-13'(FoxF1b)1 is expressed in the lateral plate mesoderm, but not in the notochord or presomitic mesoderm. Expression pattern and functional experiments indicate that these three forkhead genes are involved in the dorso-ventral patterning of the mesoderm.

Amino Acid Sequence↗

Combined hippocampal and amygdala lesions block learning of a response-independent form of occasion setting.

This study compared rats with dorsal striatal, ventrolateral prefrontal cortical, and combined lesions of the hippocampus and amygdala to sham controls on a conditional discrimination task in which contextual cues modulated a taste aversion. All groups were able to acquire this occasion setting task. The 2nd experiment functionally minimized the stimulus-response component of the paradigm, creating a "tasteless" form of occasion setting. Rats with pretraining lesions of the hippocampus and amygdala were impaired compared with shams on the acquisition of this tasteless occasion setting task. Rats with posttraining combined lesions did not retain the ability to perform the tasteless occasion setting task learned preoperatively. Rats with selective lesions of either the hippocampus or the amygdala alone were not impaired in the acquisition of the tasteless occasion setting task. The findings suggest that this occasion setting task may be learned by several redundant neural systems.

Amygdala↗

Tissue engineering of cardiac valve prostheses II: biomechanical characterization of decellularized porcine aortic heart valves.

BACKGROUND AND AIMS OF THE STUDY: For both young patients with congenital heart disease and young, growing adults there is a need for replacement heart valves that will develop with the patient. Tissue-engineered heart valves coupled with in-vitro recellularization have this potential. One approach is to use acellular tissue matrices, but the decellularization treatment must not affect the biomechanical integrity of the valvular matrix. This study investigated the effect of 0.03% (w/v) and 0.1% (w/v) sodium dodecyl sulfate (SDS) on the mechanical integrity of porcine aortic valve leaflets. METHODS: Left coronary porcine leaflets were treated with SDS (0.03% or 0.1%, w/v) in hypotonic or isotonic buffer and buffer alone. SDS in hypotonic buffer produced accellularity. Circumferential and radial specimens of treated leaflets were subjected to uniaxial tensile testing, and the effect of the buffer on leaflet morphology was assessed. Whole porcine aortic roots were also treated with 0.1% (w/v) SDS and subjected to function testing. RESULTS: SDS treatment significantly increased extensibility of the leaflet specimens, which was greater in the circumferential than radial direction. This was seen as a significantly decreased slope of both the elastic and collagen phases of the stress-strain behavior. The ultimate tensile strength and transition stress were not affected significantly; nor was there any significant difference between hypotonic buffer and hypotonic buffer + SDS treatments. Study of the leaflet morphology suggested that the increased extensibility was due to shrinkage as well as to increased hydration of the treated leaflets caused by the hypotonic buffer. CONCLUSION: SDS treatment produced a more extensible tissue with equal strength compared with the fresh aortic valve. Functionality experiments with SDS-treated whole aortic roots showed complete valve leaflet competence under physiological pressures (120 mmHg) as well as physiological leaflet kinematics.

Animals↗

Major histocompatibility complex class I-related chain A and UL16-binding protein expression on tumor cell lines of different histotypes: analysis of tumor susceptibility to NKG2D-dependent natural killer cell cytotoxicity.

NKG2D, together with NKp46 and NKp30, represents a major triggering receptor involved in the induction of cytotoxicity by both resting and activated human natural killer cells. In this study, we analyzed the expression and the functional relevance of MHC class I-related chain A (MICA) and UL16 binding protein (ULBP), the major cellular ligands for human NKG2D, in human tumor cell lines of different histological origin. We show that MICA and ULBP are frequently coexpressed by carcinoma cell lines, whereas MICA is expressed more frequently than ULBP by melanoma cell lines. Interestingly, the MICA(-) ULBP(+) phenotype was detected in most T cell leukemia cell lines, whereas the MICA(-) ULBP(-) phenotype characterized all acute myeloid leukemia and most B-cell lymphoma cell lines analyzed. These results, together with functional experiments, based on monoclonal antibody-mediated blocking of either NKG2D or its ligands, showed that killing of certain MICA(-) cell tumors is at least in part NKG2D dependent. Indeed, leukemic T cells as well as certain B-cell lymphomas were killed in a NKG2D-dependent fashion upon recognition of ULBP molecules. Moreover, ULBP could induce NKG2D-mediated NK cell triggering also in tumors coexpressing MICA. Our data suggest that the involvement of NKG2D in natural killer cell-mediated cytotoxicity strictly correlates with the expression and the surface density of MICA and ULBP on target cell tumors of different histotypes.

Carrier Proteins↗

Functional alpha1-adrenergic receptor subtypes in human right gastroepiploic artery.

AIM: To study the functional alpha1-adrenergic receptor (alpha1-AR) subtypes in human right gastroepiploic artery (RGA). METHODS: The effects of alpha2-AR, alpha1-AR, and alpha1-AR subtype selective antagonists on norepinephrine (NE)-induced vasoconstriction in isolated human RGA were observed by contractile function experiment. RESULTS: Cumulative concentration-response curves for NE were competitively antagonized in RGA by alpha2-AR selective antagonist yohimbine (pA2 6.82+/-0.28, slope 1.12+/-0.40),alpha1-AR selective antagonist prazosin (pA2 9.77+/-0.22, slope 0.90+/-0.22),alpha1A-AR selective antagonists RS17053 (pA2 8.42+/-0.20, slope 0.93+/-0.20) and 5-MU (pA2 8.42+/-0.22, slope 0.88+/-0.18),alpha1D-AR selective antagonist BMY7378 (pA2 6.84+/-0.32, slope 1.05+/-0.17), and alpha1A-,alpha1B-AR selective antagonist WB4101 (pA2 8.88+/-0.20, slope 1.15+/-0.16). The correlation coefficients between these pA2 values of alpha1-AR selective antagonists with pKi values of which obtained from alpha1A-, alpha1B- and alpha1D-AR cloned cells are 0.95, 0.82, and 0.42. After the vessels were pretreated by chlorethylclonidine (CEC), an alpha1B- and alpha1D-AR irreversible alkylating agent, the pD2 values were changed from 5.9+/-0.5 to 5.6+/-0.6 and the maximal contraction was changed from (8.9+/-3.2) g to (8.0+/-3.2) g, respectively. The difference was not significant. CONCLUSION: In human RGA, the contraction response is mainly mediated by alpha1-AR, of which alpha1A-AR plays an important role, whereas alpha1B- and alpha1D-AR are not involved in the contraction response.

Adrenergic alpha-1 Receptor Antagonists↗

Alteration of vascular response to norepinephrine, calcitonin gene-related peptide, and acetylcholine in orchidectomized rats.

AIM: To determine the long-term effects of orchidectomy on vasoreactivity. METHODS: Orchidectomized rats with or without hormone replacement were raised 1, 2, and 4 months. Vascular responses to norepinephrine, calcitonin gene-related peptide (CGRP), and acetylcholine were tested on three different arteries (thoracic aorta, pulmonary artery, and caudal artery) by functional experiments. RESULTS: Responses to norepinephrine, CGRP, and acetylcholine were not changed by 1 or 2 months deprivation of androgen. In aorta, the dose-response curve of CGRP was shifted to the left by 1 month of testosterone replacement. Response to norepinephrine was increased 4 months after orchidectomy and reversed by testosterone replacement in thoracic aorta. Orchidectomy did not affect CGRP- and acetylcholine-induced relaxation in all the arteries 4 months after orchidectomy. CONCLUSION: Compared to estrogen, the protective effects of androgen on vasoresponsiveness may be through inhibiting vasoconstriction, but is relatively weak.

Acetylcholine↗

Metabolism of simultaneously administered antipyrine and theophylline in male BN/BiRij rats before and after induction with 3-methylcholanthrene.

In order to study the metabolic activities of different P-450 enzymes in male Brown Norway rats, formation rates of antipyrine (AP) metabolites and theophylline (TH) metabolic clearance were determined. Brown Norway rats are often used in studies concerning the influence of age on liver function. Experiments were performed after simultaneous iv administration of the two compounds with and without 3-methylcholanthrene (3-MC) pretreatment. Pharmacokinetic data of both AP and TH were significantly influenced by 3-MC pretreatment. Metabolic clearance of AP increased from 6.8 +/- 1.0 (mean +/- SD, N = 23) to 18.4 +/- 7.9 (N = 10) ml.min-1.kg-1, whereas the metabolic clearance of TH increased from 1.9 +/- 0.6 to 20.0 +/- 5.1 ml.min-1.kg-1. Elimination half-life in plasma decreased from 77 +/- 10 to 33 +/- 9 min for AP and from 171 +/- 36 to 25 +/- 7 min for TH, respectively. Urinary recovery as the metabolites 3-hydroxymethylantipyrine, 4-hydroxyantipyrine, and norantipyrine accounted for approximately 36% of the administered dose in the control situation, and for approximately 21% after 3-MC pretreatment. 3-MC pretreatment strongly reduced the formation of 3-hydroxymethylantipyrine, but increased the formation rate of 4-hydroxyantipyrine and norantipyrine. Weak correlations were found between the clearances of formation of the AP metabolites and the metabolic clearance (CLm) of TH in the control rats. This may be caused by a large contribution of constitutive P-450 enzymes in the formation of AP metabolites and/or the metabolic clearance of TH in Brown Norway rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Epidermal growth factor receptor as a target for therapy with antireceptor monoclonal antibodies.

The epidermal growth factor (EGF) receptor is a potential target for antitumor therapy. Recent studies from many laboratories have found that this receptor is expressed in high levels on a variety of human tumor cells. Furthermore, the EGF receptor has been implicated in autocrine stimulation of cell growth in a number of experimental studies. We have produced anti-EGF receptor monoclonal antibodies (MAbs), which block the binding of EGF and transforming growth factor alpha (TGF-alpha), and can prevent ligand-stimulated activation of EGF receptor tyrosine kinase. These MAbs have been useful in studies of EGF receptor function. Experiments utilizing the MAbs to block ligand binding have demonstrated that autocrine stimulation of EGF receptor phosphorylation can occur via an extracellular pathway, involving TGF-alpha-mediated activation of EGF receptor on the surface of the cell. The capacity of anti-EGF receptor MAbs to inhibit cell proliferation has provided evidence of an autocrine stimulatory pathway in cultures of malignant human skin, breast, colon, and lung cells. Growth of a variety of human tumor xenografts can be inhibited in situations where autocrine dependency is demonstrable in cell culture. Imaging studies with anti-EGF receptor MAb labeled with indium 111 (111In) demonstrated selective uptake in xenografts expressing high receptor levels. Based on these observations, a phase I trial was carried out with 111In-labeled anti-EGF receptor MAb 225 IgG1 in patients with advanced squamous cell lung carcinoma, a tumor that invariably expresses large numbers of EGF receptors. In the case of squamous lung carcinoma, there is evidence that overexpression of EGF receptors correlates with worse clinical stage and worse prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

[Hepatocellular transport of bile acids and organic anions in infection and SIRS--evidence for different mechanisms for regulating membrane transport proteins].

The alteration of proinflammatory mediators during sepsis and SIRS results in a large variety of adaptive changes of metabolic and physiologic variables. This study investigated the alterations of hepatocellular transport in a rat sepsis model (LPS i.p.) as well as in a model inducing SIRS by sterile abscess formation (turpentine i.m.). Two bile acids (Cholyltaurine and Chemodeoxycholyltaurine) and one organic anion (Sulfolithocholyltaurine) were used as marker substrates to investigate the time course of hepatocellular transport function. Experiments were performed in isolated perfused rat livers and plasma membrane vesicles. During sepsis, both, the transport of bile acids and that of the organic anion was markedly reduced. In contrast no alteration of transport was detected during SIRS. However, biliary secretion of glutathione (+90%) and bile acid independent bile flow (%) were increased. mRNA levels of bile acid and organic anion transport proteins were reduced. The lowest values were noted 12 h after injection of LPS or turpentine. Almost unchanged kinetic parameters during SIRS pointed to a normal population of transporters with regard to quantity and substrate affinity. Therefore it seems that transcriptional regulation plays an important role for the expression of transport proteins during sepsis, whereas posttranscriptional regulation may be of importance during SIRS. The clinical phenomenon of septic cholestasis including jaundice implies endotoxemia and differenciates against SIRS.

Animals↗

Apoptosis induced by p75NTR overexpression requires Jun kinase-dependent phosphorylation of Bad.

The p75 neurotrophin receptor (p75NTR), a member of the tumor necrosis factor receptor superfamily, facilitates apoptosis during development and after injury to the CNS. The signaling cascades activated by p75NTR that result in apoptosis remain poorly understood. In this study, we show that overexpression of p75NTR in primary cortical neurons, in pheochromocytoma cell line (PC12) cells, and in glioma cells results in activation of Jun kinase (JNK), accumulation of cytochrome c within the cytosol, and activation of caspases 9, 6, and 3. To link p75NTR-dependent JNK activation to mitochondrial cytochrome c release, regulation of BH3-domain-only family members was examined. Transcription of BH3-domain-only family members was not induced by p75NTR, but p75NTR-dependent JNK activation resulted in phosphorylation and oligomerization of the BH3-domain-only family member Bad. Loss of function experiments using Bad dominant negatives or RNA interference demonstrated a requirement for Bad in p75NTR-induced apoptosis. Together, these studies provide the first data linking apoptosis induced by p75NTR to the phosphorylation of BH3-domain-only family members.

Animals↗

[Psychiatric disorders and disability among leprosy patients; a review].

As a gross estimate, leprosy currently affects 11-16 million patients worldwide There are currently 3600 registered patients in Turkey. The social stigma connected to leprosy makes this disease completely different from others. Even nowadays people affected by leprosy have to leave their village or are socially isolated. The physical deformity ratio is approximately 25% in other countries whereas it is more than half in Turkey. The prevalence of mental disorders among leprosy patients is higher than that among the general population. Depression is the most common psychiatric disorder among leprosy patients. Another important finding is that the long duration of the illness and physical handicaps raise the risk of psychiatric disorders. Nevertheless, the results of two studies conducted in Turkey on this subject contradict the results of international studies. Leprosy patients experience functional disabilities that limit their lives and ability to establish relation ships with others both in social and occupational fields. The physical disability rate is high (75%) in Turkey. A review of the literature revealed several papers on the psychosocial aspects of illness but few references to the degree or pattern of psychiatric disorders among leprosy patients. The main purpose of this paper is to review psychiatric disorders and disabilities in leprosy patients and to obtain concrete results.

Persons with Disabilities↗

Roles of FGF-10 on the development of diathrodial limb joints.

OBJECTIVES: Members of the fibroblast growth (FGF) family of signaling proteins are known to play important roles in limb skeletal patterning and in chondrocyte proliferation and maturation. Recent work from this laboratory showed that FGF members are expressed in limb developing joints. Thus, the present project focused on what roles these proteins may have in joint development. METHODS: Heparin-coated beads precoated with recombinant FGF-10 or GDF-5 were implanted around incipient proximal and distal joints of digits 3 and 4 in Day 6-8 chick limb buds in organ culture. Specimens were processed for whole mount in situ hybridization using antisense riboprobes encoding chick GDF-5 and FGF-10 or for histology analysis at indicated time points. RESULTS: Whole mount in situ hybridization revealed that FGF-10 is expressed, and its transcripts are present, during interzone formation. Gain-of-function experiment revealed that exogenous FGF-10 caused down-regulation of expression of FGF-10 as well as GDF-5. In specimens continuously treated with exogenous FGF-10, joint formation was markedly impaired and often resulted in fusion of contiguous cartilaginous phalanges. CONCLUSIONS: The study provides evidence for the first time that FGF-10 is expressed during joint development in addition to FGF-2 and FGF-4. The precise roles of these signaling molecules will require further work. However, it is possible to speculate that these proteins, singly or in concert, may favor proliferation of mesenchymal cells during interzone formation. Our data also show that prolonged treatment with exogenous FGF-10 leads to joint impairment and fusion. Similar defects were observed previously when other joint-associated proteins were experimentally manipulated, indicating that a fine balance among distinct regulatory molecules is needed for normal joint formation.

Animals↗

[Inducing specific antitumor effects on osteosarcoma by fused vaccine of rat dendritic cells].

BACKGROUND & OBJECTIVE: Dendritic cells (DCs) are the strongest antigen presenting cells (APCs). But immune therapy based on DCs for osteosarcoma has seldom been reported. This study was designed to investigate the immunologic potency and antitumor effects of fused vaccine of rat DCs on osteosarcoma. METHODS: Mononuclear cells in rat bone marrow were propagated in vitro under the condition of recombinant granulocytemacrophage colony-stimulating factor (rGM-CSF), recombinant interleukin-4 (rIL-4), and recombinant tumor necrosing factor-alpha (rTNF-alpha) to obtain DCs. DCs were purified by monoclonal antibody OX62 and magnetic beads, and confirmed by morphologic observation, phenotype determine, and functional experiments. Osteosarcoma cell line UMR-106 was fused with allogeneic or syngeneic DCs by electrofusion to produce the tumor vaccine. Each kind of tumor vaccine was injected subcutaneously into 10 rats to observe its specific antitumor effects. RESULTS: Survival rate of rats after injection of 1x10(7) UMR-106 cells was 70% in allogeneic tumor vaccine group, and 50% in syngeneic tumor vaccine group. The survival rats stood up to the second challenge of 1x10(7) UMR-106 cells 7 weeks after injection. After immunization of 2x10(6) UMR106-DCs, tumors in 60% of the rats bearing pre-established tumor cells diminished or vanished. CONCLUSION: Fused tumor vaccine of UMR-106 cells and allogeneic DCs might induce specific anti-tumor effects on osteosarcoma.

Animals↗

Orthopedic surgical management of hip and knee involvement in patients with juvenile rheumatoid arthritis.

Juvenile rheumatoid arthritis is the most common arthritic disease of childhood and a leading cause of childhood disability, affecting an estimated 300,000 US children and adolescents aged < or =16 years. Approximately 10% to 30% of patients experience functional deficits resulting from both the articular and systemic manifestations of their disease, including leg length inequality and deformity, that are often more crippling than joint destruction. Surgical intervention to treat bone and soft-tissue deformity, leg length inequality, and joint destruction is indicated when medical therapy has failed. Synovectomy, soft-tissue release, osteotomy, and epiphysiodesis are used to treat deformity and early joint destruction. Arthroplasty remains the primary therapy for joint destruction, although it is fraught with complications specific to this young patient population.

Arthritis, Juvenile↗

[Mechanisms of synovial joint formation].

Synovial joints are comprised of relatively simple biomechanical structures including articular cartilage, synovial membrane, synovial fluid, ligaments and a fibrous capsule; they are fundamentally important for function and quality of life. Recent studies described the spatio-temporal expression patterns of signaling molecules and transcription factors in the developing synovial joints. Though few in number, the gain and/or loss of function-experiments demonstrated direct involvement of these molecules in joint formation. This review focuses on recent advances in understanding the mechanisms of synovial joint formation in the limbs.

Animals↗