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Biomedical subjects

J Laurent

Publications and source records attributed to J Laurent.

At least 55 records · Page 3Linked to original sources
PubMed1994

Winter pollinosis in Paris.

Pollen is rarely investigated as a cause of winter respiratory symptoms. Infectious coryza and asthma are particularly common during winter, and it has been shown that environmental antigens can cause at least some cases in Paris. Recent experimental data from Calhoun et al. (1991) indicate that pollen may act synergistically with viral respiratory infections, which are particularly prevalent in winter. In the present study, we investigated, in 130 consecutive patients presenting with winter aggravation of asthma or rhinitis, winter pollinosis by skin test, radioallergosorbent test (RAST), and specific endonasal challenge test. Totals of 35, 24, and 21 patients reacted positively in skin, RAST (> 0.70 PRU/ml), and endonasal tests, respectively. Clinical features during the season established the diagnosis of winter pollinosis in 20 cases; it was due to alder pollen in 10 patients and hazel pollen in 12. The positive predictive value of the skin test was only 0.57, as compared with 0.86 for the specific endonasal test, which had a negative predictive value of 1. Our results indicate that hazel and alder pollens should be prick-tested for more often as causes of winter respiratory symptoms in Paris, even if similar manifestations were absent during previous winters, were previously present during spring or summer, or were both absent in previous winters and present in spring or summer.

Adolescent↗
PubMed1993

Pediatric liver transplantation for primary hepatocellular carcinoma associated with hepatitis virus infection.

We report two cases of early primary hepatocellular carcinoma (PHC) in children, after probable maternal transmission of hepatitis B, that were treated with orthotopic liver transplantation (OLT). Both children were 8.5 years old and had elevated levels of serum alpha-feto-protein. The diagnosis of PHC was made at 8 years and confirmed histologically. Serum hepatitis B surface antigen (HBs Ag) was detected in the mothers and suggested vertical transmission. An attempt at complete liver tumor resection failed, leading to OLT. In order to prevent recurrence of the hepatitis B virus (HBV) infection, hepatitis B immunoprophylaxis was used. Two years after OLT, one child presented with recurrent HBV infection. No tumor recurrence was observed at follow-up in either of the patients. From these two cases we conclude that (1) HBV infection may play an important causal role in PHC in children, with an even shorter incubation period than that in adults; (2) close follow-up is needed for children who are HBs Ag-positive carriers; and (3) liver transplantation should be proposed early after the diagnosis of PHC, when tumor resection is not feasible.

Carcinoma, Hepatocellular↗
PubMed1993

Testing the cognitive content-specificity hypothesis with anxious and depressed youngsters.

Beck's (1976) cognitive model of psychopathology stipulates that each emotional disorder can be characterized by a cognitive content specific to that disorder. Although other aspects of Beck's theory have been empirically supported with youngsters, few have tested the applicability of the cognitive content-specificity hypothesis to children. Forty-five youngsters in Grades 4 through 7 who met diagnostic criteria of the revised third edition of the Diagnostic and Statistical Manual of Mental Disorders for a depressive or anxiety disorder and 18 controls completed measures of anxious and depressive cognitions. Analysis revealed that the valence of depressive cognitions played an important role in distinguishing the anxious group from the depressed and mixed groups. Specifically, negatively worded items did not differentiate between groups as well as positively worded items. The anxious, depressed, and mixed depressed-anxious groups were not differentiated on the basis of their anxious cognitions. The results provide partial support for Beck's cognitive content-specificity hypothesis and the broader positive-negative affectivity construct.

Adolescent↗
PubMed1993

Cognitive, behavioral, and family factors in the differentiation of depressive and anxiety disorders during childhood.

Contribution of cognitive, behavioral, and family environment variables to the differentiation of depressive and anxiety disorders in children was explored. Fifty-nine children from Grades 4-7 (14 diagnosed with a depressive disorder, 16 diagnosed with depressive and anxiety disorders, 11 diagnosed with an anxiety disorder, and 18 nondisturbed controls) completed measures of the depressive cognitive triad, depressive cognitions, social skills, family environment, and maladaptive family messages. Results of a stepwise discriminant function analysis indicated that 2 discriminant functions composed of 7 variables from the cognitive, behavioral, and family environment domains accounted for 91% of the between-groups variance. Results suggest that depressive disorders can be distinguished from anxiety disorders on the basis of ratings of cognition, social skills, and family environment. Implications for existing research and a model of depression during childhood are discussed.

Adolescent↗
PubMed1993

Evidence for chestnut pollinosis in Paris.

The existence of chestnut pollinosis in Paris is not generally accepted in spite of the production of very large quantities of chestnut pollen in July. We carried out systematic skin-prick testing with chestnut pollen on 81 patients seen in the allergology department. The results were positive in 17 of the 47 patients presenting seasonal symptoms and in none of the 34 patients with perennial symptoms (chi 2 test = 12.91, P < 0.001). Eight of the 17 positive patients had sIgE levels above 300 IU/ml, 15 had a positive RAST and 14 had a positive nasal provocation test result. On the basis of these findings and the results of the clinical examination during the peak period of pollen emission, we diagnosed chestnut pollinosis in 11 patients. We draw our conclusions from the evidence of this form of pollinosis in the Paris region, together with the reasons why it is, as yet, rarely recognized.

Adolescent↗
PubMed1993

Proteinuria selectivity index--prognostic value in lipoid nephrosis and related diseases.

In order to predict the steroid response in lipoid nephrosis (LN), we studied age, sex, proteinuria level, histological features and proteinuria selectivity index (SI; ratio between IgG and transferrin clearances) in 52 LN cases (minimal-change disease: n = 39; focal glomerulosclerosis+IgM nephropathy: n = 13). The multivariate analysis showed that age, sex and proteinuria level were not contributive, whereas histology and SI were. The predictive value of SI was much higher than that of histological type (McFadden's r2: 47% vs. 22%, p < 0.001). Thus, SI should be systemically assessed in idiopathic nephrotic syndrome for reviewing the pathologic classification obtained by histology. However, if its prognostic value is lower than that of selectivity, initial renal biopsy remains necessary for diagnosis in adults.

Adolescent↗
PubMed1992

The Roman strains of rats as a psychogenetic tool for pharmacological investigation of working memory: example with RU 41656.

This study examined the effects of RU 41656, a dopaminergic D2 agonist, on the differential working memory performances and on the differential activities of the neurochemical systems of the Roman high (RHA) and Roman low (RLA) avoidance strains of rats. Compared with RLA, RHA performed worse in three tests of working memory (spontaneous alternation, radial maze and object recognition) and had higher levels of exploratory locomotor activity. Hippocampal and frontal cortex choline acetyltransferase (ChAT) activities were lower in RHA. Frontal cortex DA and DOPAC levels, hippocampal and striatal 5-HT and NA levels were higher in RHA. RU 41656 induced a significant improvement in working memory performance of RHA, whereas in RLA it had no effect. It decreased exploratory locomotor activity in both strains. ChAT activity in hippocampus was not affected by RU 41656 in either strain, whereas in frontal cortex it was increased in RHA but not in RLA. Hippocampal NA levels were decreased by RU 41656 in RHA but not in RLA. These results confirm previous data concerning the promnesic effect of RU 41656 and extend the finding that the Roman strains are a psychogenetic model for the behavioural, neurochemical and psychopharmacological study of the working memory in rats.

Animals↗
PubMed1992

[Acute hepatic artery thrombosis in pediatric liver transplantation: surgical thrombectomy and in situ fibrinolysis].

In pediatric liver transplantation, hepatic artery thrombosis usually leads to graft loss, early due to hepatic necrosis when it occurs during the first week following the transplant procedure, or later due to biliary complications. Liver retransplantation is the usual attitude. However, urgent surgical hepatic arterial thrombectomy to restore the blood flow can be successful when early diagnosis is made with Doppler ultrasound examination and angiography. Four hepatic arterial thrombectomies were performed as an emergency with additional intra-hepatic arterial fibrinolytic treatment, in three children, 1.5, 3 and 5.5 years of age. Mean duration between the first signs of hepatic artery thrombosis and thrombectomy was 16 hours. None of the children had an urgent liver retransplantation. A complete success was obtained in one case, with normal liver function tests and patent hepatic artery on the Doppler ultrasound examination at the present time. In the two other cases, hepatic artery thrombosis recurred, in spite of repeated thrombectomy in one case; following this attempt complications of hepatic artery thrombosis occurred in the two patients: ischemic necrosis of the left lobe (1 case), biliary leak (1 case) and stenosis of the common bile duct (2 cases). A complete success in one case and a partial success in the two others lead us to advocate urgent thrombectomy and in situ fibrinolytic treatment when early diagnosis of hepatic artery thrombosis is made.

Acute Disease↗
PubMed1991

Recombinational biases in the rearranged C1-inhibitor genes of hereditary angioedema patients.

DNA structural changes responsible for hereditary angioedema were sought in the C1-inhibitor gene, which contains unusually dense clusters of Alu repeats in various orientations. Among patients belonging to 45 unrelated families, eight partial C1-inhibitor gene deletions and a partial duplication were found. Four deletions had one of the boundaries within the gene and the other in extragenic regions--in three cases 5' of the gene and in one case 3' of the gene. The boundaries of the partial duplication and of the remaining four deletions mapped instead within a few kilobases of exon 4. The same element--Alu 1--the first of three tandem Alu repeats preceding exon 4, contained one of the breakpoints of each of these five rearrangements. Moreover, these recombination breakpoints spread over the entire length of Alu 1, in contrast with the tight clustering observed near the 5' end of Alu sequences rearranged in other human genes. Thus, two uncommon recombinational biases are observed in the Alu rearrangements of hereditary angioedema patients; one promotes the occurrence of intragenic breakpoints in a single Alu repeat, and the other allows the breaks to be distributed over the entire Alu structure rather than within the hot spot of the left Alu monomer. A region of potential Z-DNA structure, located 1.7 kb upstream of Alu 1, may contribute to both peculiarities.

Angioedema↗