Anticoagulant therapy in patients undergoing dental interventions: a critical review of the literature and current perspectives.

Patients treated with oral anticoagulant therapy (OAT) represent an issue to the dentist, as an increasing number of people are using anticoagulant drugs for cardiovascular disease. The choice of an eventual suspension or continuation of anticoagulant therapy is important when considering an efficient management of the patient. Patients in anticoagulant therapy and requiring dental procedures sometimes represent therapeutic concerns especially concerning the suspension of the anticoagulant treatment. At the moment there is no consensus among international experts of a possible discontinuation of therapy before invasive dental procedures. In this paper, the authors try to focus on this topic through a critical review of the literature. Most of the studies suggest the continuation of the anticoagulant treatment with heparin before invasive oral surgical interventions. Based on the data of the literature, two rules must be adopted in clinical practice: 1) maintenance of anticoagulation related to the international normalized ratio (INR); 2) local application of antifibrinolytic agents to ensure a proper hemostatic process. Given the widespread use of anticoagulant drugs in cardiovascular disease, dentists must often face the problem of the therapy and, since there is no consensus on the management of these patients, the authors propose, after a thorough critical review of the literature, the implementation of a multiphase protocol of surgical approach to be implemented with safety in daily clinical practice.

Comparison of Alternaria spp. collected in Italy from apple with A. mali and other AM-toxin producing strains.

Since 1999, a disease of apple caused by an Alternaria sp. has been affecting orchards in northern Italy resulting in necrotic spots on leaves and on fruit. Forty-four single-spored isolates were obtained from diseased plant materials to investigate the diversity of this fungus in Italy and to compare these isolates to isolates of Alternaria associated with apple disease in previous studies, including A. mali, causal agent of apple blotch. All isolates, including the reference strains, were tested for pathogenicity utilizing in vitro bioassays on detached leaf or on fruit ('Golden Delicious'). In addition, morphological characterizations were conducted describing both the three-dimensional sporulation pattern and the colony morphology of each isolate. In order to assess the genetic diversity within the Italian Alternaria population, sequence characterization of specific loci and anonymous regions (endoPG, OPA1-3, OPA2-1, and OPA10-2) and genetic fingerprinting based on amplified fragment length polymorphism and inter simple sequence repeat markers were performed. The single spore isolates exhibited differential pathogenicity, which did not correlate with the morphological groupings or to groupings defined by molecular approaches. Moreover, 10 pathogenic isolates out of the 44 single-spored tested were positive for the host-specific AM-toxin gene based upon polymerase chain reaction amplification using specific primers for the AM-toxin gene. This suggests that the production of the AM-toxin may be involved in pathogenesis by some of the Italian isolates of A. alternata from apple. However, this research also suggests that a number of different Alternaria genotypes and morphotypes may be responsible for the apple disease in Italy and that a single taxon cannot be defined as the sole causal agent.

Endoglin and CD-34 immunoreactivity in the assessment of microvessel density in normal pituitary and adenoma subtypes.

UNLABELLED: Vascularization is a prerequisite of tumor growth, invasion and metastasis. In the present work, microvessel density was assessed by quantitating using two different endothelial cell biomarkers, endoglin (CD-105) and CD-34. Fifty endocrinologically active and 36 clinically nonfunctioning pituitary adenomas, all surgically resected, as well as 10 autopsy-derived normal adenohypophyses were investigated by immunohistochemistry. The results showed that in every pituitary adenoma type endoglin, an assumed biomarker of proliferating endothelial cells, immunostained fewer vessels than CD-34 which revealed immunopositivity in all capillaries. Differences in endoglin versus CD-34 immunoexpression indicate varying degrees of vascularity in pituitary adenoma subtypes. The low levels of endoglin immunoexpression in pituitary tumors exposed to long-acting somatostatin analogs and dopamine agonists are consistent with the view that these agents inhibit angiogenesis. KEYWORDS: immunohistochemistry, endoglin, CD34, microvascular density, angiogenesis, pituitary.

Hemangiopericytoma of the sella mimicking pituitary adenoma: case report and review of the literature.

OBJECTIVE: Hemangiopericytoma (HPC) is a potentially malignant vascular neoplasm that in rare cases presents as a primary intracranial lesion, where most often it is meningeal in origin. Hemangiopericytoma arising within the sella turcica is an even more sporadic event. To our knowledge, only 9 cases of HPC presenting as a sellar or suprasellar mass have been reported in the literature. Often, these cases can mimic and be mistaken for a pituitary adenoma. MATERIAL AND METHODS: We report a case of an 18-year-old woman presenting with a sellar mass which was thought both clinically and radiologically to be a pituitary adenoma. RESULTS: Based on histologic, immunohistochemical and electron-microscopic studies, the diagnosis of sellar HPC was made. CONCLUSION: Hemangiopericytoma should be considered in the differential diagnosis of sellar or suprasellar masses.

New chromatographic and biochemical strategies for quick preparative isolation of tRNA.

A combination of hydrophobic chromatography on phenyl-Sepharose and reversed phase HPLC was used to purify individual tRNAs with high specific activity. The efficiency of chromatographic separation was enhanced by biochemical manipulations of the tRNA molecule, such as aminoacylation, formylation of the aminoacyl moiety and enzymatic deacylation. Optimal combinations are presented for three different cases. (i) tRNA(Phe) from Escherichia coli. This species was isolated by a combination of low pressure phenyl-Sepharose hydrophobic chromatography with RP-HPLC. (ii) tRNA(Ile) from E. coli: Aminoacylation increases the retention time for this tRNA in RP-HPLC. The recovered acylated intermediate is deacylated by reversion of the aminoacylation reaction and submitted to a second RP-HPLC run, in which deacylated tRNA(Ile) is recovered with high specific activity. (iii) tRNA(i)(Met) from Saccharomyces cerevisiae. The aminoacylated form of this tRNA is unstable. To increase stability, the aminoacylated form was formylated using E.coli: enzymes and, after one RP-HPLC step, the formylated derivative was deacylated using peptidyl-tRNA hydrolase from E.COLI: The tRNA(i)(Met) recovered after a second RP-HPLC run exhibited electrophoretic homogeneity and high specific activity upon aminoacylation. These combinations of chromatographic separation and biochemical modification can be readily adapted to the large-scale isolation of any particular tRNA.

Identification of a 43-kDa protein in human liver cytosol that binds to the 3'-untranslated region of CYP2A6 mRNA.

Hepatic expression of cytochrome P450 2A6 (CYP2A6) varies widely in humans and is induced during hepatitis; however, the mechanism regulating CYP2A6 has not been established. The murine orthologue Cyp2a5 is regulated post-transcriptionally by mRNA stabilization. A 43-kDa protein that binds to the 3'-untranslated region (3'-UTR) of Cyp2a5 mRNA has been identified, but its role in mRNA stabilization is unclear. We hypothesized that similar interactions occur between cytosolic proteins in human liver and CYP2A6 3'-UTR mRNA. We identified, by RNA electrophoretic mobility shift assay, an hepatic cytosolic protein that binds specifically to sequences in the 3'-UTR of CYP2A6. Complexes did not form with denatured proteins and were eliminated with proteinase K digestion. Complex formation was inhibited with a molar excess of unlabeled CYP2A6 RNA but not by non-specific competitor RNA. Protein-mRNA interactions were not affected by probe denaturation, suggesting that RNA secondary structure is not essential for binding. UV cross-linking of complexes revealed RNA-binding proteins in both human and mouse liver cytosols with molecular masses of approximately 43 kDa. Using truncated RNA probes corresponding to various lengths of CYP2A6 mRNA, the protein-binding site was localized to a 50-nucleotide region between bases 1478 and 1527 of the 3'-UTR. Complex formation with hepatic cytosolic protein from four human subjects correlated with levels of hepatic CYP2A6 microsomal protein, suggesting a possible regulatory role. Further characterization of the RNA-binding protein, the primary binding site, and the influence of this interaction on CYP2A6 mRNA stability will help to elucidate the relevance of these findings to the post-transcriptional control of CYP2A6.

Effect of aminoguanidine in ligature-induced periodontitis in rats.

The role of nitric oxide and reactive oxygen species is well-demonstrated in inflammation. In this study, we evaluated the effect of aminoguanidine, a nitric oxide synthase inhibitor, in a rat model of periodontitis. We induced periodontitis in rats by placing a piece of 2/0 braided silk around the lower left 1st molar. At day 8, the gingivomucosal tissue encircling the mandibular 1st molar was removed for biochemical and histological analysis. Ligation significantly increased inducible nitric oxide synthase activity and expression, and damaged tissue revealed increased neutrophil infiltration, lipid peroxidation, and positive staining for nitrotyrosine formation and poly (ADP-ribose) polymerase activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction. Aminoguanidine (100 mg/kg i.p., daily for 8 days) treatment significantly reduced all these inflammatory parameters, indicating that it protects against the tissue damage associated with periodontitis by reducing nitric oxide production and oxidative stress.

Histologic, immunohistochemical, and ultrastructural findings in a case of minocycline-associated "black thyroid".

We report on a 37-yr-old woman with known antemortem ingestion of minocyclin who died suddenly from a ruptured cerebral aneurysm. At autopsy, her thyroid gland, although not enlarged, was diffusely black, caused by the deposition of a melanin-like pigment that stained positive with Schmorl's reagent. The pigment could be bleached with permanganate, and on examination by electron microscopy, it appeared to be deposited within the thyrocyte lysosomes. Additional immunostaining with many antibodies revealed an increase in vimentin staining in the follicular epithelium compared with normal control thyroid glands. Staining for cytoplasmic thyroglobulin was markedly reduced, despite normal thyroid indices performed on stored antemortem blood. Stainable ubiquitin in the follicular epithelium appeared reduced compared with control thyroid tissues. These immunohistochemical findings may reflect disruptions of lysosomal transport and function associated with the abnormal accumulation of pigment. This appears to be the only case of minocyclin-associated "black thyroid" in which extensive immunohistochemical investigations have been performed.

Invasive thymoma metastatic to the cavernous sinus.

BACKGROUND: Thymomas are typically benign tumors of thymic epithelium. Metastases to distal sites, particularly intracranial locations, are extremely rare. Herein, we present the third case of thymoma and the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary. CASE DESCRIPTION: A 41-year-old female patient presented with headaches, stuffy nose, and drooping of the right face. A magnetic resonance imaging scan revealed a complex, multilobulated mass centered upon the right cavernous sinus. The mass was removed via transsphenoidal surgery, and histopathological investigation confirmed the diagnosis of metastatic thymoma. A positron emission tomography-computed tomography scan demonstrated a large anterior mediastinal mass. A biopsy confirmed the diagnosis of invasive thymoma morphologically identical to the World Health Organization type B2 sellar region metastasis. CONCLUSION: Although rare, thymomas can metastasize to the central nervous system. Our case is the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary.

Estrogen receptors alpha and beta immunohistochemical expression: clinicopathological correlations in pituitary adenomas.

AIM: We investigated the immunohistochemical expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) in pituitary adenoma subtypes combined with clinicopathological factors. MATERIALS AND METHODS: Pituitary adenomas (n=75) were immunostained for ERalpha and ERbeta using the streptavidin-biotin-peroxidase complex method with a monoclonal ERalpha antibody and polyclonal ERbeta antibody. RESULTS: Nuclear immunoreactivity for both receptors was highest among PRL, FSH/LH, null cell, and GH adenomas. ACTH, silent subtypes I and II corticotrophs, and subtype III adenomas were the least immunoreactive for both receptors. ACTH adenomas expressed significantly less ERalpha than FSH-LH, GH, and null cell adenomas. A significantly elevated ERalpha expression was observed in macroadenomas compared to microadenomas and non-invasive compared to invasive tumors. CONCLUSION: ERalpha and ERbeta are differentially expressed in the various pituitary adenoma subtypes suggesting a cell-specific function for these receptors. To elucidate the role of ERalpha in tumor size and invasiveness, additional studies are required.

Adrenomedullin expression in pituitary adenomas and nontumoral adenohypophyses.

Adrenomedullin (ADM) is a novel peptide originally identified in extracts of human pheochromocytoma. It is produced by several tissues, including the pituitary gland. The presence of ADM has been immunohistochemically demonstrated in pathologic pituitary glands, but no systematic study of ADM expression in human pituitary adenomas has been reported. Thus, we investigated ADM immunoexpression in 88 various hormone-secreting and clinically nonfunctioning pituitary adenoma types as well as 30 nontumoral adenohypophyses. Furthermore, ADM immunoreactivity was assessed on a 0 to +3 scale in all samples. We found strong immunoreativity for ADM in normal gonadotrophs also expressing FSH and LH whereas in the other adenohypophysial cell types expression of ADM was mild. Results showed that normal adenohypophyses were strongly immunopositive for ADM (2.18+/-0.11). Our findings demonstrate that ADM expression in the anterior pituitary is diminished in tumors as compared to the normal gland. The physiologic function of ADM is unknown, but it could act as a paracrine or autocrine factor in the adenohypophysis.

Relationships among durum wheat accessions. I. Comparative analysis of SSR, AFLP, and phenotypic data.

The determination of genetic relatedness among elite materials of crop species allows for more efficient management of breeding programs and for the protection of breeders' rights. Seventy simple sequence repeats (SSRs) and 234 amplified fragment length polymorphisms (AFLPs) were used to profile a collection of 58 durum wheat (Triticum durum Desf.) accessions, representing the most important extant breeding programs. In addition, 42 phenotypic traits, including the morphological characteristics recommended for the official distinctness, uniformity, and stability tests, were recorded. The correlation between the genetic similarities obtained with the 2 marker classes was high (r = 0.81), whereas lower values were observed between molecular and phenotypic data (r = 0.46 and 0.56 for AFLPs and SSRs, respectively). Morphological data, even if sampled in high numbers, largely failed to describe the pattern of genetic similarity, according to known pedigree data and the indications provided by molecular markers.

Diagnosis and follow-up of inborn errors of amino acid metabolism: Use of proton magnetic resonance of biological fluids.

Proton magnetic resonance spectra of biological fluids such as urine, plasma and cerebro-spinal fluid can be used for multi-component analysis of highly concentrated species, thus providing information about the general metabolism of the patient. Hydrogen containing analytes in concentration higher than 10µM are indeed often detectable in biological fluid in 15 minutes by means of an unexpensive 200 MHz spectrometer essentially without sample manipulation. Amino acids, keton bodies, organic acids and other metabolites can be easily estimated by this approach; consequently this technique represents a powerful tool particularly in the diagnosis of inborn errors of amino acid metabolism, when improving the prognosis often depends on a very early diagnosis and on an effective method for monitoring the effects of therapy.In the present paper, several cases of inherited diseases related to amino acid impaired metabolism will be presented to illustrate the importance in the diagnosis. Phenylketonuria, tyrosinemia, cystinuria, ornithinemia, argininosuccinic aciduria, maple syrup urine disease (MSUD), alkaptonuria, lysinuria and other genetic pathologies were in fact unambiguously and rapidly diagnosed by means of the identification in the biological fluids of the relevant accumulating amino acids and/or of their metabolites. The proposed technique is suitable to become, in the future, a useful routine tool for a wide neonatal screening.

Diagnosis and follow-up of cystinuria: use of proton magnetic resonance spectroscopy.

Proton Nuclear Magnetic Resonance (NMR) Spectroscopy of urine (as well as of other biological fluids) is a very powerful technique enabling multi-component analysis useful in both diagnosis and follow-up of a wide range of inherited metabolic diseases. Among these pathologies, cystinuria is characterised by accumulation in urine of four dibasic amino acids, namely lysine, arginine, ornithine and cystine; the last one, being only slightly water soluble, generates urolithiasis. The mentioned aminoacids can be detected in the urine NMR spectrum of cystinuric patients, the most abundant being the lysine (5 mM and over are often detected), whose typical signals become very high; arginine and ornithine are also usually detectable, although pathologic concentrations are lower (usually below 2mM). The proposed NMR technique is also suitable in monitoring the therapy with alpha-mercaptopropionylglycine (MPG), providing quantitation of several metabolites of interest in the follow-up of the pathology, like cystine, creatinine and citrate.

Diet treatment of branched chain ketoaciduria studied by proton magnetic resonance spectroscopy.

A novel nuclear magnetic resonance method is proposed for the diagnosis and follow-up of patients affected by branched chain ketoaciduria. The method allows quantitation of the branched chain amino acids (BCAA's) such as leucine, isoleucine and valine and of related keto- and hydroxy acids by means of a single spectrum. The method implies short time of analysis, as opposed to the very long time required by the techniques currently in use (amino acid analyzer combined with gaschromatography/mass spectrometry of keto- and hydroxyacids), it is easy and suitable for adjustements of the dietary treatment even on a daily basis. The case of a 15 days old newborn child, presenting muscular hypertonicity was unambiguously diagnosed in few minutes by means of one single NMR spectrum of urine. More interestingly, NMR spectra of serum in the following days were suitable for quantitating amino-, and keto acids as well as other metabolites of relevance in the follow up of the dietary treatment of the disease. After a diet lacking of BCAA's, to eliminate keto acids, a low BCAA diet was introduced, that succeeded in keeping the serum levels of the three amino acids within the normal range, while dropping the related keto acids.

Identification of the allergenic components of kiwi fruit and evaluation of their cross-reactivity with timothy and birch pollens.

BACKGROUND: Only a few food allergens have as yet been identified, mainly because of the difficulty of obtaining a sufficient number of patients who are clinically sensitized to a given food. This is more feasible in the case of the oral allergy syndrome (OAS), a common form of food allergy, which is especially prevalent in patients with pollinosis. OBJECTIVE: We designed a study to identify the allergens of kiwi fruit (Actinidia chinensis) by analyzing the sera of patients with OAS for kiwi and to examine the cross-reactivity of these allergens with timothy and birch pollen allergens. METHODS: Twenty-seven patients with OAS for kiwi, a positive skin prick test response and serum IgE antibody to kiwi, and a positive open kiwi challenge test result and three patients who had OAS with severe systemic symptoms, which excluded a challenge test, were included in this study. The different polypeptide components of an extract of fresh kiwi were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and analyzed by IgE immunoblotting with sera from these patients. Cross-reactivity with the two pollen extracts was assessed by inhibition of the immunoblots with pooled and individual patients' sera. RESULTS: Twelve IgE-binding components with molecular weights ranging from 12 to 64 kd were identified in the kiwi extract, but only a 30 kd component acted as major allergen, being recognized by sera of 100% of these patients. Inhibition of kiwi immunoblots with timothy and birch pollen extracts demonstrated strong cross-reactivity with some of the kiwi allergens, suggesting complete identity between certain food and pollen allergens; whereas others, particularly the 30 kd allergen, were only partially inhibited, suggesting much weaker cross-reactivity. CONCLUSIONS: Kiwi fruit contains a large number of allergens widely cross-reacting with allergens in grass and birch pollen extracts. Nevertheless, the major allergen at 30 kd appears to be specific for kiwi.