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Biomedical subjects

C Pareja

Publications and source records attributed to C Pareja.

5 recordsLinked to original sources
PubMed2001

Stereoselective nucleophilic formylation and cyanation of alpha-alkoxy- and alpha-aminoaldehydes.

The spontaneous 1,2-addition of formaldehyde N,N-dialkylhydrazones to carbohydrate-derived alpha-alkoxyaldehydes takes place under neutral conditions and in the absence of catalysts or promoters to afford the corresponding alpha-hydroxyhydrazones in good to excellent yields and with highly anti diastereoselectivities. Subsequent transformations of the hydrazono group into aldehydes and nitriles following known procedures provide a new entry into the homologation of carbohydrates and the synthesis of cyanohydrins, respectively. Additionally, reaction of methyleneaminopyrrolidine with N-Boc-protected alpha-aminoaldehydes from natural amino acids efficiently affords the corresponding adducts under the same conditions. From these adducts, a variety of biologically interesting alpha-hydroxy-beta-aminocarbonyl compounds can be accessed upon manipulation of the hydrazone moiety.

Journal Article↗
PubMed2000

[Acute precordial pain: 100 cases in 3 years].

OBJECTIVE: To find the effectiveness of diagnoses of acute precordial pain seen as an emergency at our centre. DESIGN: Observational, descriptive and retrospective study. SETTING: Urban primary care centre. PATIENTS: The 100 most recent patients who attended as an emergency with their first episode of acute precordial pain were included. STUDY PERIOD: December 1994 to March 1998. Home visits, patients without medical records and those seen on repeated attendance for precordialgia were excluded. MEASUREMENTS AND MAIN RESULTS: The emergency diagnosis and the diagnosis recorded afterwards in the clinical history of 100 people with acute precordialgia, aged 54.9 (16.7 years; 56% [n = 56] women), were gathered. Ischaemic cardiopathy (41%, n = 41) and mechanical precordialgia (36%, n = 36) were the most common initial diagnoses. We found 66.6% sensitivity and 81.4% specificity in the detection of ischaemic cardiopathy. The proportion of diagnostic errors was not linked to the pathological history of anxiety, ischaemic cardiopathy or oesophageal disease. CONCLUSIONS: 41% of precordialgias are diagnosed as presumably ischaemic and are potentially serious, although only 50% of them are confirmed as such. Our sensitivity in their diagnosis is comparable to that of other studies.

Acute Disease↗
PubMed1989

In vitro degradation of cements: a comparison of three test methods.

Three in vitro tests were evaluated on the basis of their ability to predict the relative resistance of various types of luting cements to disintegration in the oral cavity. The tests were (1) weight loss, (2) reduction in size of cement films held between glass optical flats, and (3) reduction in transverse strength. Storage media evaluated were H2O and 0.1, 0.01, and 0.001 M HAc. These data were compared with previously obtained measurements on the in vivo disintegration rates of the same cements. The best correlation with in vivo disintegration was obtained by test No. 2 when the specimens were subjected to 0.01 M HAc.

Dental Cements↗