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Biomedical subjects

C Badet

Publications and source records attributed to C Badet.

12 recordsLinked to original sources
PubMed2004

Adaptation of salivary Lactobacillus strains to xylitol.

OBJECTIVE: Acid production from sugars is one of the virulence factors of cariogenic bacteria. To eliminate this factor, many authors have suggested using sugar substitutes like xylitol, which is not fermented by most oral bacteria. The aim of this work was to investigate whether oral strains of lactobacilli unable to utilise xylitol could become able to utilise this polyol. DESIGN: Twenty-eight oral strains and six ATCC strains of lactobacilli were tested. None was initially able to produce acids from xylitol. Media containing only xylitol was used in order to see if an adaptation was possible. The acid production from xylitol was measured by recording the pH variations of the culture medium. The acids produced were identified by HPLC. RESULTS: After a 15-days culture, 10 strains produced acids. After a 40-days culture, 11 more strains produced acid. When acid production occurred, lactic, formic, acetic, propionic and butyric acids were the organic acids formed by all the strains. CONCLUSIONS: Adaptation of oral strains of lactobacilli to xylitol can occur in vitro.

Adaptation, Physiological↗
PubMed2001

Identification of salivary Lactobacillus rhamnosus species by DNA profiling and a specific probe.

The Lactobacillus genus has been shown to be associated with the dental carious process, but little is known about the species related to the decay, although Lactobacillus rhamnosus is suspected to be the most implicated species. Conventional identification methods based on biochemical criteria lead to ambiguous results, since the Lactobacillus species found in saliva are phenotypically close. To clarify the role of this genus in the evolution of carious disease, this work aimed to find a rapid and reliable method for identifying the L. rhamnosus species. Methods based on hybridization with DNA probes and DNA amplification by PCR were used. The dominant salivary Lactobacillus species (reference strains from the ATCC) were selected for this purpose as well as some wild strains isolated from children's saliva. DNA profiling using semirandom polymorphic DNA amplification (semi-RAPD) generated specific patterns for L. rhamnosus ATCC 7469. The profiles of all L. rhamnosus strains tested were similar and could be grouped; these strains shared four common fragments. Wild strains first identified with classic methods shared common patterns with the L. rhamnosus species and could be reclassified. One fragment of the profile was purified, cloned, used as a probe and found to be specific to the L. rhamnosus species. These results may help to localize this species within its ecological niche and to elucidate the progression of the carious process.

Bacterial Typing Techniques↗
PubMed1994

[Plasma methoxyamines assay: a practical advance for the diagnosis of pheochromocytoma].

Measurement of plasma methoxyamines is aimed to provide a reliable plasma marker readily available for any patient suspected of having a pheochromocytoma. The present HPLC method is able to detect methoxyamine amounts as low as 0.2 nmoles/l and allows the determination of both free or conjugated methoxyamines (metanephrine MN and normetanephrine NMN) in normal subjects, treated or untreated patients and a fortiori in pheochromocytoma. The analytical specificity is excellent. Among most usual antihypertensive drugs, only conversion enzyme inhibitors and diuretics induce in some patients a moderate increase of NMN with minor consequence in values interpretation. The kidney plays a major role in the blood clearance of methoxyamines and any alteration of renal function is associated to the increase of plasma methoxyamine levels. Plasma methoxyamines have a long half-life and are long-lasting integrated markers of catecholamine secretion; at variance with plasma free catecholamines, they are able to afford the presence of a secreting pheochromocytoma whatever the clinical presentation--asymptomatic or paroxysmal form between the crisis. The diagnostic sensitivity (at least 98%) is equal to that of urinary methoxyamines, far higher than plasma or urine catecholamines or urine VMA (60 to 70%).

Adrenal Gland Neoplasms↗
PubMed1993

[Multiple endocrine neoplasia type 1. Digestive hormones in the screening].

Detection of subjects from a multiple endocrine neoplasia type 1 family must rest on clinical, biochemical and radiological data, since study of the genome is unable to detect these subjects. In the new family described here, 6 out of the 14 subjects explored were affected. One had a confirmed pancreatic endocrine tumour and in 3 others a pancreatic endocrine tumour was highly probable, since insulin and glucagon levels, as well as ultrasonic exploration of the pancreas were pathological. Measurements of gastrointestinal hormones gave normal results in all cases. We conclude that to detect this endocrine neoplasia in subjects at risk it seems necessary to measure plasma insulin levels and perform an abdominal ultrasonography.

Adolescent↗
PubMed1992

Malignant pheochromocytoma: a series of 14 cases observed between 1966 and 1990.

We report 14 patients (9 males, 5 females) aged 15-59 years, treated for malignant pheochromocytoma. These patients were observed during the 1966-1990 period along with 68 other patients presenting benign pheochromocytomas. From the initial general presentation of the 14 patients, two groups could be individualized. In seven patients, the initial presentation seemed benign. After the excision, the recovery was complete, but patients recurred on average 7.8 yr later (range 1-22 yr). Tumors were intraadrenal in six cases (5 single, 1 bilateral) and extraadrenal in one case. In the seven remaining patients, malignancy was evident from the first examination. The tumors were intraadrenal in 2 cases, extraadrenal in 5 cases. Frequency of extraadrenal locations (6/14) was in this series significantly higher than in benign forms (9/68). Diagnosis of malignancy was based on metastases in 12 cases (lymph nodes in 5, bones in 5, liver in 4, lung in 2, brain in 1) and on peritumoral extension in 2 cases. No biological specificity was detected in urinary excretion of catecholamines or its metabolites. In 6 patients so far studied, an uptake of 131I MIBG was found in the tumor and/or metastases. Four patients received therapeutic doses of 131I MIBG and in three of them, this treatment led to a good result within a follow-up range of 12 to 66 months.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Iodobenzylguanidine↗
PubMed1992

[Pheochromocytoma. Study of a personal series of 85 cases].

The study of a personal series of 85 cases observed by the same endocrinologist over a period of 40 years shows the modifications of clinical presentation and biological methods of diagnosis and treatment. There is a striking increase in the percentage of patients without any cardiac or vascular manifestations. The methoxyamines assay has the best sensitivity and specificity even in asymptomatic tumors. The recent development of this assay in the blood is very efficient. The tumor may be found with an abdominal CT scan. The use of NMR is not fruitful. The 131I MIBG scintigraphy is necessary if the CT scan is not informative and in malignant forms. The malignancy is more frequent (16.5%) than classical according to the long duration of the disease. The quite good prognosis is improved by the administration of 131I MIBG. The surgery was safer and without mortality over the last 15 years.

Adrenal Gland Neoplasms↗
PubMed1992

MRI and CT in a case of pituitary abscess.

We report the case of a woman admitted for hypopituitarism of sudden onset, in whom conventional radiography, CT and MRT suggested a pituitary tumour with supra- and intrasellar extensions. The surgical findings and the clinical course under antibiotic therapy transformed this diagnosis into one of pituitary abscess by a pyogenic micro-organism. Pituitary abscess is an exceptional lesion. Despite the advent of CT and MRI, its preoperative diagnosis remains difficult. However, the presence of an intrasellar expansive process with liquid centre and contrast-enhanced outline should suggest the possibility of an abscess, particularly when the pituitary lesion is associated with a sphenoidal sinus effusion.

Abscess↗
PubMed1991

Sources of carbon for hepatic glycogen synthesis in the conscious dog.

To identify the source(s) of carbon for the indirect pathway of hepatic glycogen synthesis, we studied nine 42-h fasted conscious dogs given a continuous intraduodenal infusion of glucose, labeled with [1-13C]glucose and [3-3H]glucose, at 8 mg.kg-1.min-1 for 240 min. Glycogen formation by the direct pathway was measured by 13C-NMR. Net hepatic balances of glucose, gluconeogenic amino acids, lactate, and glycerol were determined using the arteriovenous difference technique. During the steady-state period (the final hour of the infusion), 81% of the glucose infused was absorbed as glucose. Net gut output of lactate and alanine accounted for 5% and 3% of the glucose infused, respectively. The cumulative net hepatic uptakes were: glucose, 15.5 +/- 3.8 g; gluconeogenic amino acids, 32.2 +/- 2.2 mmol (2.9 +/- 0.2 g of glucose equivalents); and glycerol, 6.1 +/- 0.9 mmol (0.6 +/- 0.1 g of glucose equivalents). The liver produced a net of 29.2 +/- 9.6 mmol of lactate (2.6 +/- 0.8 g of glucose equivalents). Net hepatic glycogen synthesis totaled 9.3 +/- 2.5 g (1.8 +/- 0.4 g/100 g liver), with the direct pathway being responsible for 57 +/- 10%. Thus, net hepatic glucose uptake was sufficient to account for all glycogen formed by both the direct and indirect pathways. Total net hepatic uptake of gluconeogenic precursors (gluconeogenic amino acids, glycerol, and lactate) was able to account for only 20% of net glycogen synthesis by the indirect pathway. In a net sense, our data are consistent with an intrahepatic origin for most of the three-carbon precursors used for indirect glycogen synthesis.

Amino Acids↗
PubMed1989

[An orodental epidemiologic survey conducted in the school environment in the Great Southwest of France].

Within the framework of a national epidemiological study, a regional study of the oral conditions of a representative survey of 1174 schoolchildren aged 6 to 15 years, was conducted in the south-west Region of France. This Region studied by the Dental School of Bordeaux comprised the departments of Dordogne, Gironde, Landes, Lot-et-Garonne, Pyrénées-Atlantiques, Charente and Charente-Maritime. Only 8.8% of the 15 years old children were caries free. The mean DMFT was 4.3 at age 12 years whereas the mean DMFS at the same age was 6.6. At the age of 15, these indices reached respectively the values of 6.5 and 11.4. The most affected sites were the pits and fissures, followed by the approximal and smooth surfaces (respectively 59.3%, 25.4% and 15.3% at age 15). The plaque index varied only slightly around 0.9, whereas the calculus index increased regularly from 0.0 to 0.4 between the ages of 6 to 15 years. The gingival index, which was 0.1 at age 6, remained stable around 0.3 between 8 and 15 years of age.

Adolescent↗