Accuracy and safety of pretest probability assessment of deep vein thrombosis by physicians in training using the explicit Wells clinical model.
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Adult↗
Biomedical subjects
A Penaloza
Publications and source records attributed to A Penaloza.
[Ototoxicity-related dysequilibrium].
Many substances may be the source of dizziness or transient equilibrium disturbances due to dysfunction of the CNS or to an impairment of visual or proprioceptive informations. Other agents are responsible for drop of arterial pressure by changing position, including antihypertensive drugs, alpha-blocking agents used in urology, antipsychotics, cyclic antidepressants, vasodilators and nitrates, dopaminergic antiparkinson drugs, sedatives, etc. Only drug with true ototoxic properties will be discussed here, namely substances that are able to damage the inner ear (cochlear or vestibular damage) or the VIIIth cranial nerve, causing impairment of equilibrium and/or (most often) hearing. No relevant data report the actual incidence of ototoxic problems, but more than 130 products have been classified as potentially dangerous. Individual susceptibiity seems highly variable, but some predisposing factors have been identified: renal failure, age, combination of ototoxic drugs, familial sensitivity to ototoxic effects or previous neurosensorial deficit. We will first discuss the ototoxic medications that have certainly been extensively studied and among which we find several antibiotics (especially aminoglycosides and macrolides), the loop diuretics, and some antimalarial or chemotherapeutic agents. Environmental toxins and drug of abuse will then be discussed briefly because scientific data are much less significant. Early recognition of subjects who are at risk of developing ototoxicity, use of therapeutic monitoring and close observation of cochleo-vestibular functions in high risk situations (often not easy in critical patients) are the best way to prevent severe complications that have occasionally disastrous consequences on the quality of further life.
Anti-Bacterial Agents↗
[Ototoxicity-related vertigo].
Many substances may be the source of dizziness or transient equilibrium disturbances due to dysfunction of the CNS or to an impairment of visual or proprioceptive informations. Other agents are responsible for drop of arterial pressure by changing position, including antihypertensive drugs, alpha-blocking agents used in urology, antipsychotics, cyclic antidepressants, vasodilators and nitrates, dopaminergic antiparkinson drugs, sedatives, etc. Only drug with true ototoxic properties will be discussed here, namely substances that are able to damage the inner ear (cochlear or vestibular damage) or the VIIIth cranial nerve, causing impairment of equilibrium and/or (most often) hearing. No relevant data report the actual incidence of ototoxic problems, but more than 130 products have been classified as potentially dangerous. Individual susceptibility seems highly variable, but some predisposing factors have been identified: renal failure, age, combination of ototoxic drugs, familial sensitivity to ototoxic effects or previous neurosensorial deficit. We will first discuss the ototoxic medications that have certainly been extensively studied and among which we find several antibiotics (especially aminoglycosides and macrolides), the loop diuretics, and some antimalarial or chemotherapeutic agents. Environmental toxins and drug of abuse will then be discussed briefly because scientific data are much less significant. Early recognition of subjects who are at risk of developing ototoxicity, use of therapeutic monitoring and close observation of cochleovestibular functions in high risk situations (often not easy in critical patients) are the best way to prevent severe complications that have occasionally disastrous consequences on the quality of further life.
Anti-Bacterial Agents↗
[Serotonin syndrome].
The serotonin syndrome is a hyperserotoninergic state resulting from an excess of intrasynaptic 5-hydroxytryptamine, induced by multiple psychotropic agents, but also non psychiatric drugs. It is a potentially dangerous and sometimes lethal condition. The clinical manifestations usually include cognitive, neuromuscular and autonomic features and are mediated by the action of serotonin on various subtypes of receptors. The main differential diagnosis is the neuroleptic malignant syndrome. Treatment is mainly supportive. No pharmacological agent has been definitely demonstrated really effective. However, reports of cases treated with the 5-HT2 blockers, including cyproheptadine or chlorpromazine have suggested that these agents could have some efficacy. Serotonin syndrome is a toxic condition which requires heightened clinical awareness among physicians in order to prevent, recognize, and treat the condition promptly.
Diagnosis, Differential↗
Quantitative ultrasound and dual X-ray absorptiometry measurements of the calcaneus in patients on maintenance hemodialysis.
It has been suggested that quantitative ultrasound measurements (QUS), which reflect mainly bone density, could be influenced by bone micro-architecture. The aim of the study was to assess whether the relationship of QUS to dual X-ray absorptiometry (DXA) would reflect abnormalities of bone structure observed in renal osteodystrophy. QUS and bone mineral density of the calcaneus (BMDc) were measured by DXA in 30 patients on maintenance hemodialysis and 34 age- and gender-matched controls. QUS parameters and BMDc were significantly lower in hemodialysis patients than in controls (speed of sound [SOS] and broadband ultrasound attenuation [BUA], p = 0. 030; stiffness, p = 0.003; BMDc, p = 0.006). Bone measurements were not correlated with serum parathyroid hormone (PTH). The regression lines of SOS, BUA, and stiffness to BMDc were not significantly different from that of the controls. When dividing the patients into two subgroups according to their median PTH (203 pg/mL), the slopes of the regression lines of BUA to BMDc were significantly different between these two subgroups (p = 0.052). The slope of the subgroup with PTH </= 203 pg/mL was significantly different from that of the controls (p = 0.030). In conclusion, QUS of the calcaneus can be used for bone assessment in patients on maintenance hemodialysis. The differences in the slopes of patients with a less pronounced degree of hyperparathyroidism compared with patients with a higher degree of hyperparathyroidism and to controls suggest that BUA of the calcaneus contains information on bone complementary to DXA measured at the same site. The clinical relevance of this finding is presently unclear.
Absorptiometry, Photon↗
Labeled neoglycoproteins and human lectins as diagnostic and potential functional markers in salivary glands of patients with Sjögren's syndrome.
OBJECTIVE: The profile of glycans and their recognition by endogenous receptors (lectins) are increasingly attributed to disease process. Monitoring this can provide information on the pathogenesis of Sjögren's syndrome (SS). Commonly, plant lectins are employed for phenomenological glycan mapping. To go beyond this approach restricted to binding of exogenous probes, new markers measure ligand properties of glycans to human (not plant) lectins and the presence of sugar receptors completing a protein-carbohydrate recognition system. Carrier-immobilized sugar epitopes (neoglycoproteins) and purified human lectins establish this innovative panel. METHODS: The host defence molecules mannan binding lectin, serum amyloid P component, and the macrophage migration inhibitory factor-binding sarcolectin, selected for their involvement in cell destructive mechanisms, were purified and labeled. The plant lectins SNA and MAA were employed to monitor regulation of potential ligand sites for I-type lectins and galectins. Asialofetuin was tested as a "pan-galectin selective" probe. The specific binding characteristics were determined by quantitative morphometry and statistical analysis. RESULTS: Diagnostic information emerged from this analysis. The percentage of stained tissue area was significantly different between SS and control specimens after processing with GlcNAc and Man-bearing neoglycoproteins and the 2 tested serum lectins. For separation of cases of primary and secondary SS, the staining intensity with the asialoglycoprotein, sarcolectin, and the exogenous alpha2,6-sialylated glycan-binding lectin SNA was statistically significant. CONCLUSION: Saccharide-presenting probes to measure the cellular capacity to bind glycan epitopes and human lectins as sensors for endogenous binding sites have proven to be useful as diagnostic tools. We suggest the differences we observed reflect aberrations from the normal cellular homeostasis with relevance for the pathogenesis of SS and its manifestation as a primary or secondary syndrome.
Binding Sites↗
D-mannose and N-acetylglucosamine moieties and their respective binding sites in salivary glands of Sjögren's syndrome.
OBJECTIVE: Sjögren's syndrome (SS) is an autoimmune exocrinopathy. The mannose binding lectin (MBL), a pluripotent molecule of the innate immune system, is involved in the pathogenesis of autoimmune diseases. We investigated whether specific ligands for MBL and MBL related structures could be reliable markers in cases of SS. METHODS: The labial salivary glands of 19 patients fulfilling the diagnostic criteria for primary (n=11) and secondary SS (n=8) were studied. Seven healthy women served as controls. Computer assisted microscopy was employed to determine quantitatively the percentage of positive structures (acini, ducts, and interlobular connective tissue), the staining intensity, and the level of staining heterogeneity for 4 glycohistochemical probes including wheat germ agglutinin and concanavalin (Con A) as lectins, and mannose and N-acetylglucosamine as parts of neoglycoproteins. The data were evaluated by discriminant analysis. RESULTS: The data strongly suggest that MBL related structures, if not MBL itself, could play distinct roles in the pathogenesis of primary versus secondary SS. Further, quantitative determination of the level of expression of D-mannose and N-acetylglucosamine and their respective binding sites in labial salivary gland acini offers a powerful diagnostic tool for distinguishing primary from secondary SS. CONCLUSION: In SS labial salivary glands, determination of the level of acceptor sites for wheat germ agglutinin, Con A, D-mannose, and N-acetylglucosamine provides information on the roles played by glycoforms in SS. The methodology and data described in this paper should provide pathologists with objective diagnostic markers for SS. Our results should enhance the biological understanding of this pathology.
Acetylglucosamine↗
Sialic acid residues in the labial salivary glands from Sjögren's syndrome patients.
OBJECTIVE: To investigate the composition and expression of sialic acid in the labial salivary glands (LSG) in Sjögren's syndrome (SS). METHODS: LSG of 19 patients with primary SS (n = 11) or secondary SS (n = 8) were studied. Specimens from 7 healthy women served as controls. Computer-assisted microscopy was employed to quantitatively determine the percentage of positive structures, the staining intensity and the heterogeneity for the 4 biotinylated plant lectins Tritricum vulgaris L. (WGA), Maackia amurensis (MAA), Sambucus nigra (SNA) and Canavalia ensiformis L. (Con A). RESULTS: In the acini there was a significant decrease in the staining heterogeneity of WGA in SS compared to controls; the same was observed with respect to MAA staining in the connective tissue and extralobular ducts. In the intralobular ducts, primary SS differed from normal and secondary SS mainly in terms of a decrease in the percentage of positively labeled MAA tissue. In addition, Con A stained acinar cells were significantly more numerous in secondary SS compared with primary SS. CONCLUSION: Differences in the degree of glycoconjugate sialylation were found in SS labial salivary glands, and may play a role in the disease process.
Diagnosis, Differential↗