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Biomedical subjects

G Durand

Publications and source records attributed to G Durand.

At least 343 records · Page 19Linked to original sources

Measurement of serum alpha 1-acid glycoprotein and alpha 1-antitrypsin desialylation in liver disease.

To determine whether the presence of circulating desialylated glycoproteins reflect the existence and/or the severity of liver disease, 73 patients were evaluated with liver biopsies, conventional liver function tests, and the measurement of the degree of desialylation of two glycoproteins alpha 1-acid glycoprotein (alpha 1-AGP) and alpha 1-antitrypsin (alpha 1-AT). A combination of two immunological methods, available as routine laboratory tests, was used for the determination of the desialylation of alpha 1-AGP and alpha 1-AT. The severity of liver disease was assessed by a clinical classification depending upon the presence or absence of four complications (jaundice, ascites, hepatic encephalopathy, and weight loss). The presence of serum desialylated alpha 1-AGP did not allow detection of mild liver disease, but asialo alpha 1-AGP (and to a lesser extent of asialo-alpha 1-(AT) correlated with the severity of liver disease. The sensitivity of desialylated alpha 1-AGP in detection of severe liver disease was 65%, and its specificity was 80%.

Adult↗

Endocytosis and binding of asialoorosomucoid by hepatocytes from rats with jejunoileal bypass.

Rats with jejunoileal bypass were used to study the biological activity of the hepatic binding protein. Hepatocytes were prepared 11 weeks after surgical procedure, and presence of asialoorosomucoid in serum has been determined. Compared to control rat hepatocytes, endocytosis of [3H]asialoorosomucoid by bypassed rat hepatocytes was decreased by about 60%. This was due to a decreased number of total and surface receptors. In most sera, an accumulation of asialoorosomucoid was found. A reduction of protein synthesis or turnover could be considered.

Animals↗

Bronchial aneurysms mimicking aortic aneurysms: endovascular treatment in two patients.

Bronchial artery dilatation and aneurysm formation is a potential complication of local inflammation, especially in bronchiectasis. When the bronchial artery has an ectopic origin from the inferior segment of the aortic arch, aneurysms may mimick aortic aneurysms. Despite this particular location, endovascular treatment is possible. We report two such aneurysms that were successfully embolized with steel coils.

Aneurysm↗

Age-related changes in ethanolamine glycerophospholipid fatty acid levels in rat frontal cortex and hippocampus.

Morphological and biochemical alterations are associated with a progressive age-related cognitive deficit. Plasmenylethanolamine, the major brain plasmalogen, may be modified during aging because of a possible antioxidant role and involvement in synaptic transmission. Two- and 18-month-old rats were used to study the effect of aging on the levels and acyl composition of plasmenylethanolamine (PmE), phosphatidylethanolamine (PE), and phosphatidylserine (PS) in the frontal cortex and hippocampus. Aging only reduced significantly the PE levels in the frontal cortex. In 18-month-old rats, the fatty acid composition of the three phospholipid classes studied showed an increase of monounsaturated fatty acid (18:1 n-9 and 20:1 n-9) and a decrease in polyunsaturated fatty acid (PUFAs), essentially docosahexaenoic acid (DHA). DHA was markedly decreased in hippocampus PE. DHA, but also arachidonic acid, were considerably lower in frontal cortex PmE. PS modifications were similar in both regions. Hippocampus and frontal cortex underwent specific age-induced modifications in PmE and PE acyl composition. This could produce different effects on the functional ability of these two structures involved in the processes of specific memorization.

Aging↗

DHA-enriched phospholipid diets modulate age-related alterations in rat hippocampus.

Our previous work on rat hippocampus showed that a loss of docosahexaenoic acid (DHA) occurs in the fatty acid composition of phosphatidylethanolamine (PE), plasmenylethanolamine (PmE) and phosphatidylserine (PS) with increasing age. The present study investigated whether a DHA-enriched phospholipid dietary supplement could restore DHA levels and cholinergic activity. Male rats were fed a balanced diet containing both linoleic and alpha-linolenic acids until the age of 2, 18 and 21 months. From 18 to 21 months, one subgroup received a diet supplemented with DHA-enriched phospholipids from egg yolk (E-PL), and another a diet with DHA-enriched phospholipids from pig brain (B-PL). Compared to the control diet, the E-PL diet restored the proportion of polyunsaturated fatty acids (PUFAs: 22:6n-3 and 20:4n-6) in PE and PmE, while enhancing spontaneous and evoked-acetylcholine (Ach) release. The B-PL diet had no effect on PUFAs, but increased basal extracellular levels of Ach in 21-month-old rats as compared to the age-matched control. Our results show that supplementation with DHA-enriched egg PL can enhance Ach release and correct PUFA composition.

Acetylcholine↗

Angiotensin II type 1 receptor gene polymorphism is associated with an increased vascular reactivity in the human mammary artery in vitro.

A gene polymorphism of the angiotensin II (AII) type 1 receptor has been described previously (A to C transversion at position 1166). Besides the epidemiological studies needed to determine a possible relationship between the polymorphism and some cardiovascular diseases, no study has been conducted to determine the impact of the polymorphism on vascular functions. At subthreshold concentrations, within the physiological range, AII potentiates alpha-adrenergic-dependent vascular tone. We investigated phenylephrine-induced tone and its amplification by AII (10 pmol/l) in human internal mammary artery rings mounted in organ baths. We performed concentration-response curves to phenylephrine (0.1-100 micromol/l) before and after pretreatment with AII (10 pmol/l). Patients had the genotype AA (n = 20) or the A to C transversion (AC/CC, n = 30). Contractions to phenylephrine (0.1-100 micromol/l) were significantly higher in rings from AC/CC than from AA patients (maximum response: 1.47+/-0.07 vs. 1.22+/-0.06 mN/mg, p < 0.001). AII (10 pmol/l) induced a significant potentiation of phenylephrine-induced contraction (e.g. 58.9% increase in tone with 1 micromol/l phenylephrine, p < 0.001) which was significantly lower in the AC/CC than in the AA group (46+/-9 vs. 66+/-7% with 1 micromol/l phenylephrine, p < 0.01). Contractions to AII (1 or 100 nmol/l) were not significantly affected by the genotype. Although the study was performed in arteries from patients with a coronary artery disease, these changes in vascular reactivity might be of interest in the understanding of the relationship between a possible higher probability of cardiovascular disorder and the genetic polymorphism of the AII type 1 receptor.

Aged↗

Changes in auditory brainstem responses in alpha-linolenic acid deficiency as a function of age in rats.

Auditory brainstem responses (ABRs) to click stimuli have been compared in young (21-day-old), adult (6-month-old), and old (18-month-old) rats fed a normal (Arachid-Colza) or an alpha-linolenic acid deficient (Arachid only) diet. Wave I amplitude and latency did not show any significant change with either age or diet. However, wave III showed a progressive decrease in amplitude and latency from young to adult and from adult to old rats having a normal diet. With alpha-linolenic acid deficiency, wave III amplitude and latency values decreased faster than in the normal diet control groups. Although final values in the old groups with the two diets were similar, with alpha-linolenic acid deficiency values for wave III decreased to this final level in the adult group. These data indicate that the central auditory nervous system ages faster, or earlier, with a fatty acid deficiency.

Aging↗

[Prevention of wasting and opportunistic infections in HIV-infected patients in West Africa: a realistic and necessary strategy before antiretroviral treatment].

The medical inequalities between countries of the North and South (infrastructure, drug availability, medical techniques) are particularly marked in terms of the challenge posed by HIV infection. We propose a strategy for monitoring adult patients in West Africa that is appropriate to the situation in the field and to economic constraints. The aim of this strategy is to increase the quality of life and the life expectancy of HIV-infected adults and to prevent the overcrowding of hospital departments with patients in the terminal phase of AIDS. We analyzed the biological and clinical spectrum of HIV infection before the onset of the diseases that define AIDS (excluding pulmonary tuberculosis). We found that it was particularly important to diagnose B-stage diseases early, especially atypical chronic cutaneous and mucous diseases. Careful analysis of data from a routine hemogram (total lymphocyte count 2500/ml; paradoxical eosinopenia), even in the absence of a CD4 lymphocyte count, should also enable clinicians from a wide variety of health structures to identify the HIV-infected patients most likely to benefit from more detailed clinical follow up, prophylaxis of opportunistic infections using cotrimoxazole, nutritional checkups and prevention of wasting. Cachexia is the most common AIDS-associated disease in West African patients. It involves an overall decrease in calorific intake, diarrhea, immune system activation, an increase in TNFalpha production and greater energy expenditure when resting. Recent nutritional studies have shown that it is vital to optimize the calorific intake of HIV-infected patients presenting with chronic diarrhea, before the onset of severe immune deficiency, to prevent wasting. So, spontaneous calorific intake should de routinely determined in HIV-infected patients and an optimal diet provided. Specific training in nutrition is required for doctors and nurses, as is consideration of the logistic organization required to provide nutritional support to HIV-infected adults. Despite the large number of individuals infected and the lack of sophisticated paraclinical facilities, we feel that it is possible to establish rational management "a minima" of HIV infection in West Africa, whilst waiting for antiretroviral drugs to become more widely available. This strategy could be of direct benefit to patients without swallowing up the financial resources of the health system in expensive biological follow up. Such basic management is also required before the new antiretroviral drugs become widely available. Research should be carried out in parallel in several reference centers in West Africa to determine the most effective associations of antiretroviral drugs and the optimal timing of treatment during the course of infection and to assess the potential side effects of these drugs in HIV patients exposed to recurrent antigenic stimulation by a wide diversity of pathogens.

AIDS-Related Opportunistic Infections↗