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Biomedical subjects

G Brulé

Publications and source records attributed to G Brulé.

At least 19 recordsLinked to original sources
PubMed2003

Improvement of rheological properties of firm acid gels by skim milk heating is conserved after stirring.

The enhancement of the strength of set acid gels by heating milk was related to rheological parameters (water retention capacity, storage modulus) of corresponding stirred gels. To obtain accurate rheological data from stirred gel it was necessary to maintain a constant granulometry of gel particles and to recognize time after stirring as a contributing factor. Two hours after stirring, the gel exhibited a higher storage modulus when milk was heated above 80 degrees C. A measurement of viscosity of just-stirred yoghurt was sufficient to predict correctly the quality of a stirred gel analysed by viscoelastic measurements. Increased resistance to syneresis of just-stirred gels was related to higher viscosity. The quantity of beta-lactoglobulin (beta-Ig) bound to casein micelles explains the improvement of these gel qualities. We have considered that the structure of the initial firm gel (mesostructure level) was conserved in fragments within the stirred gel. Consequently, the explanation given by various authors for the effect of heating milk on the properties of set gels can also be applied to stirred gels. The same mechanism, described in literature for structure formation of set gels from acidified milk is purposed to explain the role of heating milk on the recovery of gel structure after stirring. The beta-Ig association with casein micelles during heating favoured micelle connections during the acidification. It also favoured the association of gel fragments after stirring during the recovery in gel structure.

Animals↗
PubMed1999

High intensity pulsed electric fields applied to egg white: effect on Salmonella Enteritidis inactivation and protein denaturation.

High-intensity electric fields have been successfully applied to the destruction of Salmonella Enteritidis in diaultrafiltered egg white. The effects of electric field strength (from 20 to 35 kV x cm(-1)), pulse frequency (from 100 to 900 Hz), pulse number (from 2 to 8), temperature (from 4 to 30 degrees C), pH (from 7 to 9), and inoculum size (from 10(3) to 10(7) CFU x ml(-1)) were tested through a multifactorial experimental design. Experimental results indicate that, for Salmonella inactivation, the electric field intensity is the dominant factor with a strongly positive effect, strengthened by its positive interaction with pulse number. Pulse number, temperature, and pH have also significant positive effects but to a lesser extent. In the most efficient conditions, the pulsed electric field (PEF) treatment is capable of 3.5 log10 reduction in viable salmonellae. Simultaneously, the measure of surface hydrophobicity does not indicate any increase after PEF treatment. These results suggest that no protein denaturation occurs, unlike what is observed after comparable heat treatment in terms of Salmonella inactivation (55 degrees C for 15 min).

Colony Count, Microbial↗
PubMed1999

Rapid growth of Salmonella enteritidis in egg white reconstituted from industrial egg white powder.

The aim of this study was to evaluate the consequences of the egg white-drying process on egg white ability to limit Salmonella Enteritidis growth in addition to the elucidation of the factors involved. We observed rapid growth of Salmonella Enteritidis inoculated in egg white reconstituted from industrial powder in comparison with that observed in liquid egg white collected in the laboratory: Salmonella cell counts rose from 10(3) to 10(8) cells/ml of egg white from powder during 24 h incubation at 30 degrees C. This rapid growth was observed in powder from all egg-breaking factories investigated, and it was comparable to that observed in optimum medium (tryptone soy broth). In view of the mechanism of egg white resistance and the major role played by iron availability and by ovotransferrin, we investigated several hypotheses to explain this rapid growth: iron provided during the drying process and/or denaturation of protein (especially ovotransferrin). The rapid growth observed in egg white reconstituted from powder was in relation to egg white protein denaturation and especially ovotransferrin denaturation during powder pasteurization that enhanced the availability of iron necessary for Salmonella growth. The major role played by ovotransferrin and iron deficiency on Salmonella growth in egg white was illustrated in this study.

Animals↗
PubMed1996

Novel monoacetoneglucose derivatives with calcium antagonist activity.

Ethers and thioethers of monosaccharides have been synthesised which show potent toxicity to mouse (LD50 > or = 4 g.kg-1 O.W. and 0.2 to 1.5 g.kg-1 I.P.W.). A study of calcium antagonist activity for the full series of compounds indicated that the activity was similar for both O- and S- ethers and maximum activities were observed for monoacetoneglucose ethers possessing carbon chain close to 8 carbons.

Animals↗
PubMed1994

Two-step chromatographic procedure for the purification of hen egg white ovomucin, lysozyme, ovotransferrin and ovalbumin and characterization of purified proteins.

An improved procedure is described involving gel permeation and anion-exchange chromatography for the purification of four major hen egg white proteins. The procedure involves a first-step purification of ovomucin and lysozyme by gel permeation on a Superose 6 Prep Grade column. In the second step, anion-exchange chromatography on Q Sepharose Fast Flow led to the isolation of ovotransferrin and ovalbumin from a gel permeation chromatographic peak. The purities were estimated as ca. 80, 100, 80 and 100% for ovomucin, lysozyme, ovotransferrin and ovalbumin, respectively. The purification yield was over 60% for each protein. Further characterization of purified lysozyme revealed that it was fully active and homogeneous in relation to the electrospray ionization mass spectrum. The electrospray ionization mass spectrum showed different ovotransferrin species. The amino acid composition of purified ovomucin was compared to those published previously.

Amino Acids↗
PubMed1983

[Modification of the affinity of actomyosin calcium sites by anions].

ATP hydrolysis-pCa and isometric tension-pCa relationships were determined for isolated myofibrils under a variety of ionic conditions i.e. in presence of Cl- ions (normal conditions), in presence of CH3COO- or CH3OSO3- (ions replacing all or a part of Cl- ions). In all ionic conditions, these relationships have a S-shape. For each ionic condition, the relationships between isometric tension or ATP hydrolysis and pCa were parallel, but the isometric tension-pCa was shifted towards a smaller value of pCa. The relation between ATP hydrolysis and pCa has been analysed by means of the enzymatic reaction described by Michaelis-Menten. The analysis of isometric tension-pCa relationship can be also described by using the consecutive scheme of reaction for the co-operative action of two Ca2+ ions in the process of tension activation given by Ashley & Moisescu (1977) for barnacle myofibrils. The dissociation constant (k1) equal to the one that we determined for the ATP hydrolysis probably corresponds to the Ca2+ binding site of troponin (M1). This association (M1-Ca) would lead to the phosphorylation of the second site (M2) localized on myosin, which can bind a Ca2+ ion. In presence of CH3COO-, ATP hydrolysis (V) was increased with no change of the affinity of the first site for the Ca2+ ion. At the opposite, V did not change but the affinity of M1 site was decreased in presence of CH3OSO3-. CH3OSO3- must be considered as a competitive inhibitor whereas CH3COO- must be considered as an activator ion of the ATP hydrolysis reaction. In all cases, the relationship between isometric tension and ATP hydrolysis was hyperbolic.

Acetates↗
PubMed1983

[Relapses of malignant nonseminomatous germinal testicular tumors].

18 relapses of non seminomatous germ cell cancer of the testis are studied, among a group of 112 patients treated from 1974 to 1978, of which 90 are in complete remission. The study of these cases shows the bad prognosis value of yolk sac tumor component at histological examination. Relapses are more frequent in the stages with lymph node involvement treated by retroperitoneal lymphadenectomy followed by chemotherapy without cis-platinum. Cis-platinum chemotherapy decreases relapse rate in theses stages and increases complete remission rate in metastatic stages.

Cisplatin↗
PubMed1983

[Digestion of milk proteins in the abomasum of the preruminant calf. Gastric evacuation after a test meal].

In this study, we used fasted, preruminant calves fitted with a double proximal cannula in the duodenum; gastric evacuation was investigated by recovering products leaving the abomasum after a test meal. Five types of meal were given: whole milk, skimmed milk, casein solution in water, casein solution in a mineral medium simulating the permeate of highly-filtered milk, and whey. Gastric emptying of nitrogen was relatively slow. The coagulation of "milk diets" slowed down this emptying. Precipitation of "casein diets" at acid pH also slowed down emptying, but to a lesser degree. The "casein diets", more proteolyzed than the "milk diets", released larger amounts of non-protein nitrogen (NPN) into the intestine. Calcium emptying was highly related to NPN emptying, demonstrating the important role of acid peptides (phosphopeptides) from casein hydrolysis.

Abomasum↗
PubMed1982

[Role of the excision of thoracic lesions in the treatment of metastatic malignant germinal tumors of the testis].

Among 112 cases of non-seminomatous testicular tumours treated from 1974 to 1978, there were 13 thoracotomies for the excision of thoracic lesions: in 4 cases for recurrence, in 9 for incomplete remission. In 8 cases, one of the 4 recurrences and 7 of the 9 Stages III, a cure was obtained. In all cases thoracic surgery was combined with chemotherapy including bleomycin and cis platinum and in some cases lombo-aortic lymph node dissection. The hope of cure at metastatic stages of non-seminomatous testicular tumours is 50%.

Bleomycin↗
PubMed1982

[Cerebral metastases of malignant germinal tumors of the testis].

Cerebral metastases occur in 6% of cases of testicular cancer. In our study of 5 cases they occurred during the course of the disease (with a delay of 4-18 months, at the same time as pulmonary and abdominal metastases). The prognosis in these cases is poor (presence of choriocarcinomatous or vitelline elements, advanced stages). The diagnosis is easily established (clinical, encephalogram, scanner); the prognosis is hopeless (5 deaths in 3-90 days). When a metastasis is the first diagnostic clue (one case), the prognosis is slightly better (9 month survival). The incidence of cerebral metastasis is the same now as it was before the introduction of effective chemotherapy in patients who die from testicular cancer, but the death rate from this malignancy has decreased since the introduction of active chemotherapy with cisplatin. Hence, there is no indication for prophylactic treatment for cerebral metastases in patients in remission since metastases only appear in cases which are resistant to treatment.

Abdominal Neoplasms↗
PubMed1981

[2 N methyl 9 hydroxy-ellipticine in treatment of metastatic breast cancers (author's transl)].

A phase II trial was conducted in 57 patients with advanced metastatic breast cancer given 2-N-methyl 9-hydroxy-ellipticine (NMHE) as 100 mg/m2 weekly. Evaluation of response, after at least 4 injections, was possible in 46 patients. Two complete regressions (of 3 and 12 months) and 7 regressions of over 50 p. cent were observed, a total regression rate of 19 p. cent. Regression was mainly observed in cutaneous or subcutaneous metastases. No objective regression was noted for pulmonary or hepatic metastases. Bone metastases were not taken in account when assessing response to treatment. Absence of haematological changes must be emphasized. The most frequent side effects were anorexia, nausea +/- vomiting and dryness of mouth. Major toxicity was intravascular haemolysis, observed in 6 of 175 patients receiving NMHE in the Institut Gustave-Roussy, always controlled by symptomatic treatment. This product, of acceptable efficacy in breast cancer treatment, will probably occupy an original place in anti-cancer chemotherapy because of its lack of myelotoxicity.

Alkaloids↗
PubMed1980

Cisplatinumdiamminodichloride (CPDD) in chemotherapy of cancers: a phase II therapeutic trial.

We have conducted a phase II trial of cisplatinumdiamminodichloride (CPDD) which not only demonstrated its remarkable activity in embryonic carcinoma of the testes, but also in ovarian carcinoma, in melanoma, and in epidermoid carcinoma, especially of the head and of the uterus cervix. Its toxicity, manifested mainly in the digestive and renal tracts, confines its administration to hospitalized patients only. This compound is now indicated in combination therapy for the above-mentioned tumors.

Adolescent↗
PubMed1979

[Cis-diammino-dichloro-platinum therapy of cancers; phase II therapeutic trial].

We have conducted a phase II trial of cisdiammino-dichloro platinum (CDDP) which demonstrates its remarkable activity in testis embryonic carcinoma, in ovary carcinoma and in epidermoid cancers, especially head and neck and uterus cervix carcinoma. Its toxicity in mainly digestive and renal. This compound is now indicated in combinations in the case of the above mentioned tumors.

Adolescent↗