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Biomedical subjects

C Perret

Publications and source records attributed to C Perret.

At least 127 records · Page 7Linked to original sources
PubMed1993

Estrogen-induced calbindin-D 9k gene expression in the rat uterus during the estrous cycle: late antagonistic effect of progesterone.

Progesterone modulates estrogen-stimulated responses in the uterus. Calbindin-D 9k (CaBP9k), a 17 beta-estradiol-responsive gene expressed in the uterus, was used as a marker to examine the interactions between endogenous progesterone and estradiol in the rat. The variations in uterine CaBP9k messenger RNAs (mRNAs) during the rat estrous cycle indicated that CaBP9k gene expression was greatest during the estrogen-dominated phases (proestrus and estrus) and became totally repressed during diestrus, when progesterone predominates. Estradiol was found to be the major controlling factor of CaBP9k gene expression in vivo, progesterone antagonizing estrogen-induced CaBP9k gene expression. The inhibitory role of progesterone was further examined in two experiments. Mature cyclic rats were injected with the progesterone antagonist RU486 before the progesterone surge of proestrus, and the estrous cycle was mimicked in ovariectomized rats by sequential injections of estrogen and progestin. Progesterone did not appear to be involved in the rapid decrease in CaBP9k mRNA during estrus but was implicated in the down-regulation of the estrogen-stimulated CaBP9k gene expression at the end of estrus and during diestrus. This delayed effect of progesterone was confirmed in the ovariectomized rat model. CaBP9k mRNA accumulation in estrogen-primed ovariectomized rats was suppressed by estrogen followed 1 h later by the progesterone agonist R5020. This effect occurred more than 24 h after progestin treatment. The inhibition of the estrogen-induced CaBP9k gene expression in the rat uterus by progesterone is certainly mediated by the progesterone receptor, because progesterone had no effect without estrogen priming or when the antagonist RU486 was used. The delayed progesterone effect probably does not involve depletion of nuclear estrogen receptors, the major rapid mechanism proposed for estrogen inhibition by progesterone in the rodent uterus, or control of estrogen receptor synthesis, as shown by Northern blot analysis of estrogen receptor mRNA.

Animals↗
PubMed1993

[The pulmonary manifestations of diving accidents].

Scuba diving is associated with risks of drowning, lung barotrauma and decompression sickness. In case of near-drowning, irreversible neurologic lesions or death may follow an acute hypoxemia or a cardiopulmonary arrest. Therefore, victims of drowning should benefit from an immediate and prolonged cardiopulmonary resuscitation. Lung barotrauma are due to the failure of expanding lung gases to escape during ascent; they are likely to be complicated by arterial gas embolism. They can follow a panic ascent even from a shallow depth. Most of decompression procedures induce the formation of asymptomatic venous gas bubbles, normally filtrated and eliminated by the lungs. In case of massive intravenous bubbling, the filtering capacity of the lungs can be overwhelmed and the lung microcirculation damaged up to the point of provoking a cardio-respiratory failure.

Adult↗
PubMed1993

[Biological and parasitic variations in horses infested and reinfested by Trichinella spiralis].

Seven mares were infected with 20,000 Trichinella spiralis larvae; 2 of them were reinfected 22 wk later with the same amount of larvae. The course of infection in horses was assessed by serology (ELISA), biochemistry (aldolase activity), parasitology and histopathology. In each animal, infection was followed by a significant rise in specific antibody titers culminating at 5-10 wk post-infection (pi) and decreasing thereafter. Reinfection was followed by a slight rise in antibody levels. Aldolase activity increased during the first infection, but was not modified by reinfection. The parasite burden was maximum 20 wk pi (24-145 larvae/g according to localisation) and was very low at 52 wk pi (0.4-5 larvae/g). Compared to mares infected only once, the number of parasites in the reinfected animals was similar 28 wk pi but much lower 40 wk pi. Moreover, 6 wk post-reinfection, the larvae were surrounded by a large inflammatory granuloma which could have been caused by larvae from the reinfection batch. These experiments confirm the susceptibility of horses to Trichinella spiralis and the rapid disappearance of specific antibodies which prevents usual serological methods from being used in the diagnosis of infected animals. Reinfection could help the horse to eliminate the larvae more rapidly.

Animals↗
PubMed1993

[Contribution of imaging techniques in acute neonatal renal pathology].

Ultrasound is the first imaging modality used to evaluate acute renal disease in neonates. Normal findings and abnormalities seen in venous or arterial thrombosis, hemodynamic shock, or sepsis are reviewed. Transient changes due to intoxications, tubular disorders, or congenital nephrotic syndrome are considerably less common.

Acute Disease↗
PubMed1992

[Rhabdomyolysis, acute renal insufficiency and hypercalcemia].

Acute renal failure is a severe and frequent complication of rhabdomyolysis. During the early polyuric phase, hypercalcemia is observed in around 30% of cases. The principal mechanism is the liberation of calcium from areas of muscular necrosis. Two cases of toxic rhabdomyolysis with secondary hypercalcemia are described.

Acute Kidney Injury↗
PubMed1992

[Sepsis: confusion of terms].

Recent developments in the pathophysiology and treatment of sepsis have clearly shown the confusion produced by the imprecise terminology used to define the various facets of the sepsis process. The criteria required to diagnose bacteremia, sepsis, sepsis syndrome or septic shock vary from one author to the other. This inaccuracy accounts for the inability to compare the results of therapeutic investigation from different groups. The aim of this article is to point out the necessity of standardized terminology and to propose definitions which might be appropriate.

Bacterial Infections↗
PubMed1992

[Treatment of eye tumors by accelerated proton beams. 7 years experience].

The therapeutic results of 1070 cases of intraocular tumors treated with an accelerated proton beam at the University Eye Clinic of Lausanne and at the Paul Scherrer Institute of Villigen are analysed. This total is composed of 981 cases of uveal melanomas treated by proton beam as first treatment modality, 42 cases of recurrent choroidal melanomas, 16 cases of conjunctival melanomas, 8 cases of choroidal hemangiomas, 18 cases of uveal metastases and of 5 other ocular tumors. The mortality rate at 5 years for tumors treated with an accelerated proton beam as first treatment modality was 13%, and the mortality rate of recurrent melanomas was 23%. The risk factor for life expectancy analysed with the Cox model pointed out that the largest tumor diameter, the width of the tumor, the presence of an extrocular extension and the age of the patient were the most significant parameters. The conclusions of this study are compared with those found in available literature.

Conjunctival Neoplasms↗
PubMed1992

A novel score for predicting the mortality of septic shock patients.

OBJECTIVE: To establish a prognostic scoring system for septic shock patients. DESIGN: The clinical, biological, and hemodynamic data of these patients were retrospectively explored to select variables independently associated with outcome. According to the risk of death, ratings from 0 to 2 points were attributed to each value. SETTING: Medical intensive care service of a 1,000-bed tertiary care university medical center. PATIENTS: Eighty-eight patients in septic shock in whom hemodynamic measurements were performed using pulmonary artery flotation catheters. RESULTS: Fourteen clinical, biological, and hemodynamic variables were selected and rated for each patient. A Simplified Septic Shock Score, available immediately after admission and catheterization, was established by adding the rates of these variables. The mean Simplified Septic Shock Score was 2.5 +/- 1.7 (SD) in 43 survivors and 6.5 +/- 2.3 in 45 nonsurvivors (p less than .0001). Some underlying diseases and characteristics of infections also correlated with the outcome. Further ratings from 0 to 2 points were attributed to these conditions. A Complete Septic Shock Score was calculated by adding these rates to the Simplified Septic Shock Score. The Complete Septic Shock Score had a slightly better prognostic value than the Simplified Septic Shock Score, but it could be determined only after the availability of the microbiological data. The mean Complete Septic Shock Score was 3.1 +/- 1.9 in survivors and 8.4 +/- 2.6 in nonsurvivors (p less than .0001). Both Simplified and Complete Septic Shock Scores showed better association with patient outcome than the Simplified Acute Physiology Score or the Acute Physiology and Chronic Health Evaluation (APACHE II) score. CONCLUSIONS: The Simplified and the Complete Septic Shock Scores are simple scoring systems that appear to predict the outcome of septic shock patients more accurately than general scoring systems, such as the Simplified Acute Physiology Score and APACHE II score. These septic shock scores might be useful in assessing the severity of septic shock patients.

Adult↗
PubMed1992

Calbindin-D9K gene expression in the lung of the rat. Absence of regulation by 1,25-dihydroxyvitamin D3 and estrogen.

Calbindin-D9K (CaBP9K) is classically considered to be the molecular expression of 1,25-dihydroxyvitamin D3. The hormone is known to regulate the rat CaBP9K gene in duodenal tissue at transcriptional and posttranscriptional levels. This study shows that the CaBP9K gene is expressed in the rat lung, and that this expression is probably not vitamin D- or estrogen-dependent. The CaBP9K gene is not expressed in alveolar macrophages, but CaBP9K messenger RNA (mRNA) was localized by in situ hybridization in alveolar epithelial cells. CaBP9K mRNA was detected as early as the 20th day of gestation. The quantity of CaBP9K mRNA gradually increased during growth, from 1-77 days after birth, whereas the CaBP9K concentration dramatically increased from day 19 to day 20 of gestation. Vitamin D-deficient male rats (8 weeks old) were given a single injection of 1,25-dihydroxyvitamin D3 (650 pmol/100 g body wt) and killed 1 h and 24 h after injection. The hormonal treatment resulted in a rise in duodenal CaBP9K mRNA, but no significant change in lung extracted CaBP9K mRNA. Mature ovariectomized rats were injected with 17 beta-estradiol (0.5 microgram/100 g body wt) and killed 24, 48, and 72 h later. The CaBP9K mRNA concentration in the uterus was markedly dependent on estrogen; that of the lung was not. The factors regulating the CaBP9K gene expression in the lung remain to be determined.

Aging↗
PubMed1992

[Diabetes mellitus and pancreatic cancer: a case-control study in greater Montreal, Quebec, Canada].

In a population-based case-control study of dietary risk factors in French Canadians in Montreal, a total of 179 cases and 239 controls were interviewed between 1984 and 1988. It was found that the frequency of diabetes was almost three times higher in cases of pancreatic cancer (16%) than in the controls (6%), with an Odds Ratio (OR) of 2.52 and a Confidence Interval (CI) of 1.04-6.11. Fifty per cent of the pancreatic cancer cases had this disease before the cancer was diagnosed, compared with 71% of the controls at the time of the study. Those aged 50 years and over accounted for 75% of the cases and 71% of the controls (diabetic subjects); 68% of the cases were treated with a combination of diet and oral hypoglycemic agents compared with 86% of the controls. Insulin was used by 32% of the cases and 14% of the controls. These results suggest that diabetes may play a major role in the etiopathogenesis of pancreatic cancer in this urban population. A lot of controversy remains about the precise role of diabetes, and further studies are needed for a better assessment and understanding of the mechanisms of this association.

Adult↗
PubMed1991

DNase I-hypersensitive sites are associated, in a tissue-specific manner, with expression of the calbindin-D9k-encoding gene.

We have examined the chromatin structure of a 28-kb chromosomal region containing the gene (CaBP9k) encoding calbindin-D9k in different rat tissues. DNase I-hypersensitive sites (HSs) were probed with DNase I using an indirect end-labeling technique. Duodenal chromatin, where the gene is strongly expressed, contained one major HS (HS4) and three minor HSs (HS2, HS3 and HS5) near the promoter region. The HS4 was mapped just upstream from the promoter region and had the characteristics of a tissue-specific HS. The HS5 was located at the transcription start point, it included the TATA box and its presence was correlated with a promoter function. The duodenal chromatin contained two additional HSs, a major HS (HS1) located approx. 3.5 kb upstream from the cap site and a minor HS (HS6) in the second intron at +0.5 kb. Despite the marked effect of 1,25-dihydroxyvitamin D3 (DHD3) on the CaBP9k mRNA level, the pattern of HSs in duodenal chromatin was unchanged after stimulation with DHD3. The liver chromatin contained one major HS (HS1) identical to the duodenum HS1 (although this tissue does not express CaBP9k). It also contained a liver-specific HS (HS0) 0.1 kb upstream from HS1. The interaction of HS0 with HS1 could explain the absence of CaBP9k expression in the liver. Thus, specific sets of HSs are associated with various functional states of CaBP9k in a tissue-specific manner.

Amino Acid Sequence↗
PubMed1991

Family aggregation of cancer of the prostate in Quebec: the tip of the iceberg.

Cancer of the prostate is one of the most common cancers among males in North America. Although some causative factors have been suggested by several surveys, the etiology of this common cancer is poorly understood. In a case-control study of prostatic cancer in Greater Montreal, 21 of 140 patients with prostatic cancer (15.0%) gave a positive family history of the same cancer, as compared with two cases among 101 (2.0%) population-based controls. This indicates about an eightfold difference in occurrence of cancer of the prostate among first-degree family members of the case group with an odds ratio (OR) of 8.7 and 95% CI, 2.00-38.17. In this report we present the pedigrees of three families (two cases and one control) with four pathologically confirmed cases of cancer of the prostate in each family. This data suggest that a familial predisposition to prostatic cancer may become apparent in later decades of life. In these family aggregations, in addition to the genetic factors, environmental factors may also play an important role in the etiology of the same cancer among family members.

Aged↗
PubMed1991

Esophageal and mouth pressure during sniffs with and without nasal occlusion.

The sniff maneuver has recently been advocated for assessing inspiratory muscle strength. We characterized the relationship between mouth pressure (Pmo) and esophageal pressure (Pes) during sniffs performed with open, semi-occluded, and occluded nose. In seven normal subjects, pressure was simultaneously measured with a mouthpiece (Pmo) an esophageal balloon (Pes) during high- and low-intensity sniffs performed from FRC. With open nose, the mean ratio Pmo/Pes was 0.96 +/- 0.05 (mean +/- SE). The mean ratio Pmo/Pes was not significantly different in high- and low-intensity sniffs. With one nostril occluded, the mean ratio Pmo/Pes was 1.03 +/- 0.04. The ratio Pmo/Pes was significantly higher than with open nose for all sniffs (P less than 0.05) and low-intensity sniffs (P less than 0.01). With both nostrils occluded, the mean ratio Pmo/Pes was 1.06 +/- 0.03, with occasional marked overestimation of Pes by Pmo. We conclude that Pmo generally reflects Pes during sniffs performed with open and semi-occluded nose, but not with complete nasal occlusion.

Adult↗
PubMed1991

Tenascin expression in hyperproliferative skin diseases.

The expression of tenascin, a recently discovered extracellular matrix glycoprotein, was studied by immunohistochemistry in normal human skin and in a number of skin diseases with epidermal hyperproliferation such as psoriasis, basal cell carcinoma, Bowen's disease and solar keratosis. Tenascin expression in the upper dermis of normal skin was found to vary from almost absent to patchy along the basal membrane. Staining was continuous and intense around blood vessels, hair follicles and eccrine sweat ducts. In basal cell carcinoma a marked expression of tenascin was found in the tumour stroma, especially adjacent to the basal membrane surrounding the tumour cell nests. In Bowen's disease and solar keratosis, tenascin expression was found in the dermis next to the keratinocytes. In psoriasis the dermal papillae of clinically involved skin were intensely stained and a continuous band of tenascin was present in the upper dermis along the basal membrane. The distribution of tenascin differed from other known extracellular matrix components.

Animals↗