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Biomedical subjects

C Lorentz

Publications and source records attributed to C Lorentz.

6 recordsLinked to original sources
PubMed2006

Gene expression profiling of CD34+ cells identifies a molecular signature of chronic myeloid leukemia blast crisis.

Despite recent success in the treatment of early-stage disease, blastic phase (BP) of chronic myeloid leukemia (CML) that is characterized by rapid expansion of therapy-refractory and differentiation-arrested blasts, remains a therapeutic challenge. The development of resistance upon continuous administration of imatinib mesylate is associated with poor prognosis pointing to the need for alternative therapeutic strategies and a better understanding of the molecular mechanisms underlying disease progression. To identify transcriptional signatures that may explain pathological characteristics and aggressive behavior of BP blasts, we performed comparative gene expression profiling on CD34+ Ph+ cells purified from patients with untreated newly diagnosed chronic phase CML (CP, n=11) and from patients in BP (n=9) using Affymetrix oligonucleotide arrays. Supervised microarray data analysis revealed 114 differentially expressed genes (P<10(-4)), 34 genes displaying more than two-fold transcriptional changes when comparing CP and BP groups. While 24 of these genes were downregulated, 10 genes, especially suppressor of cytokine signalling 2 (SOCS2), CAMPATH-1 antigen (CD52), and four human leukocyte antigen-related genes were strongly overexpressed in BP. Expression of selected genes was validated by real-time-polymerase chain reaction and flow cytometry. Our data suggest the existence of a common gene expression profile of CML-BP and provide new insight into the molecular phenotype of blasts associated with disease progression and high malignancy.

Adult↗
PubMed1997

Monometoxytrityl derivatives of uridine as inhibitors of a human recombinant UDP-glucuronosyltransferase: UGT1*6.

A series of inhibitors of the human liver recombinant UDP-glucuronosyltransferase 1*6 derived from uridine were synthetized as probes of the binding site of the cosubstrate, UDP-glucuronic acid. If triphenylmethanol or uridine alone failed to inhibit the glucuronidation of 4-methylumbelliferone, the trityl derivatives of uridine were found to be very effective inhibitors of the enzyme (Ki 4.4 to 73 microM). The type of inhibition (competitive or mixed) varied with the substitutions on the uracile or on the triphenylmethyl moiety by halogen atoms or methyl groups. Structural features for the binding of the cofactor are postulated.

Animals↗
PubMed1990

[Acute respiratory distress syndrome in the initial phase of myocardial infarction in adults].

Four patients developed an acute respiratory distress syndrome characterised by clinical and radiological signs of pulmonary oedema, a protein-rich oedema, severe hypoxemia refractory to oxygen therapy, contrasting with normal left ventricular filling pressures and indicating increased permeability of the alveolo-capillary membrane, 24 to 72 hours after the onset of acute myocardial infarction. After having excluded the usual causes of the acute respiratory distress syndrome, the authors suggest that acute myocardial infarction, especially when extensive, may cause a lesion of the alveolo-capillary membrane by an unknown mechanism. Treatment consisted in mechanical ventilation with positive expiratory pressures in 3 cases and with continuous positive pressure during spontaneous respiration in the third patient and in relay with controlled ventilation in the other two. These techniques of ventilation improved the hypoxemia and led to complete cure in all cases without evolution to pulmonary fibrosis. In addition to mechanical ventilation, all patients were given systematic antibiotic therapy because of the possibility of an infectious etiology while waiting for the results of microbiological and serological testing and because of the high risk of superinfection which plays an essential part in the outcome of the condition. The immediate response to treatment was favourable in all cases. One patient died suddenly of cardiogenic shock two weeks after this episode. The other patients are still alive 39, 38 and 20 months after infarction. The importance of the diagnosis of the acute respiratory distress syndrome in the acute phase of myocardial infarction resides in its therapeutic implications which are quite different to those of cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[Annulo-aortic ectasia].

On the basis of a literature review and the study of 18 cases, the authors examine annuloaortic ectasia, which involves dilatation of the fibrous ring of the heart at the aortic orifice, marked by aortic regurgitation and dystrophic aneurysm of the ascending aorta. The authors noted a predominantly muscular disorder (14 males, 4 females) often detected from an assessment of aortic regurgitation without clinical, radiologic or specific electrical features. The value of echocardiography and Doppler echocardiography is clearly apparent from the diagnosis of the disease, monitoring of progress, selection of patients for invasive pre-operative explorations and post-operative surveillance. The developing gravity of this disease is stressed, rapid repercussions in the left ventricle intervening more than complications due to ectasia itself. This indicates the urgency of complete replacement of the whole ascending aorta and of the aortic valve with reimplantation of coronary arteries as in the Bentall or Bentall-Cabrol surgical intervention, seven cases of which have been reported with satisfactory results.

Adult↗