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C Charpentier

Publications and source records attributed to C Charpentier.

At least 37 records · Page 2Linked to original sources

A case of mitochondrial encephalomyopathy associated with a muscle coenzyme Q10 deficiency.

We report severe coenzyme Q10 deficiency of muscle in a 4-year-old boy presenting with progressive muscle weakness, seizures, cerebellar syndrome, and a raised cerebro-spinal fluid lactate concentration. State-3 respiratory rates of muscle mitochondria with glutamate, pyruvate, palmitoylcarnitine, and succinate as respiratory substrates were markedly reduced, whereas ascorbate/N,N,N',N'-tetramethyl-p-phenylenediamine were oxidized normally. The activities of complexes I, II, III and IV of the electron transport chain were normal, but the activities of complexes I+III and II+III, both systems requiring coenzyme Q10 as an electron carrier, were dramatically decreased. These results suggested a defect in the mitochondrial coenzyme Q10 content. This was confirmed by the direct assessment of coenzyme Q10 level by high-performance liquid chromatography in patient's muscle homogenate and isolated mitochondria, revealing levels of 16% and 6% of the control values, respectively. We did not find any impairment of the respiratory chain either in a lymphoblastoid cell line or in skin cultured fibroblasts from the patient, suggesting that the coenzyme Q10 depletion was tissue-specific. This is a new case of a muscle deficiency of mitochondrial coenzyme Q in a patient suffering from an encephalomyopathy.

Cerebellar Ataxia↗

Diffuse leukodystrophy in an infant with cytochrome-c oxidase deficiency.

A 25-month-old boy, born to consanguineous parents, had progressive spastic tetraplegia, and increased signal of the white matter on cerebral T2-weighted magnetic resonance imaging indicative of diffuse leukodystrophy. Elevated blood and cerebrospinal fluid lactate levels pointed to a respiratory chain defect. Cytochrome-c oxidase deficiency was demonstrated in cultured skin fibroblasts and skeletal muscle. This report extends the phenotype of COX deficiency in infancy. Systematic study of blood and CSF lactate should be carried out in every infant with leukodystrophy.

Brain↗

Reversal of late septic shock with supraphysiologic doses of hydrocortisone.

OBJECTIVES: Preliminary studies have suggested that low doses of corticosteroids might rapidly improve hemodynamics in late septic shock treated with catecholamines. We examined the effect of hydrocortisone on shock reversal, hemodynamics, and survival in this particular setting. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: Two intensive care units of a University hospital. PATIENTS: Forty-one patients with septic shock requiring catecholamine for >48 hrs. INTERVENTIONS: Patients were randomly assigned either hydrocortisone (100 mg i.v. three times daily for 5 days) or matching placebo. MEASUREMENTS AND MAIN RESULTS: Reversal of shock was defined by a stable systolic arterial pressure (>90 mm Hg) for > or =24 hrs without catecholamine or fluid infusion. Of the 22 hydrocortisone-treated patients and 19 placebo-treated patients, 15 (68%) and 4 (21%) achieved 7-day shock reversal, respectively, a difference of 47% (95% confidence interval 17% to 77%; p = .007). Serial invasive hemodynamic measurements for 5 days did not show significant differences between both groups. At 28-day follow-up, reversal of shock was higher in the hydrocortisone group (p = .005). Crude 28-day mortality was 7 (32%) of 22 treated patients and 12 (63%) of 19 placebo patients, a difference of 31% (95% confidence interval 1% to 61%; p = .091). Shock reversal within 7 days after the onset of corticosteroid therapy was a very strong predictor of survival. There were no significant differences in outcome in responders and nonresponders to a short corticotropin test. The respective rates of gastrointestinal bleeding and secondary infections did not differ between both groups. CONCLUSIONS: Administration of modest doses of hydrocortisone in the setting of pressor-dependent septic shock for a mean of >96 hrs resulted in a significant improvement in hemodynamics and a beneficial effect on survival. These beneficial effects do not appear related to adrenocortical insufficiency.

APACHE↗

[Renal harvesting from donors in cardiac arrest: report of 3 cases and surgical technique].

During periods of transplant organ shortage, techniques designed to "salvage" transplants must be developed. The authors report three cases of renal harvesting from donors in cardiac arrest, in which the use of in situ perfusion-cooling with transfemoral introduction of Gillot's catheter resulted in six good quality transplants. The indications, surgical technique, alternatives and results are discussed.

Adult↗

Comparison of norepinephrine and dobutamine to epinephrine for hemodynamics, lactate metabolism, and gastric tonometric variables in septic shock: a prospective, randomized study.

OBJECTIVES: To compare the effects of norepinephrine and dobutamine to epinephrine on hemodynamics, lactate metabolism, and gastric tonometric variables in hyperdynamic dopamine-resistant septic shock. DESIGN: A prospective, intervention, randomized clinical trial. SETTING: Adult medical/surgical intensive care unit in a university hospital. PATIENTS: 30 patients with a cardiac index (CI) > 3.51 x min(-1) x m(-2) and a mean arterial pressure (MAP) < or = 60 mmHg after volume loading and dopamine 20 microg/kg per min and either oliguria or hyperlactatemia. INTERVENTIONS: Patients were randomized to receive an infusion of either norepinephrine-dobutamine or epinephrine titrated to obtain an MAP greater than 80 mmHg with a stable or increased CI. MEASUREMENTS AND MAIN RESULTS: Baseline measurements included: hemodynamic and tonometric parameters, arterial and mixed venous gases, and lactate and pyruvate blood levels. These measurements were repeated after 1, 6, 12, and 24 h. All the patients fulfilled the therapeutic goals. No statistical difference was found between epinephrine and norepinephrine-dobutamine for systemic hemodynamic measurements. Considering metabolic and tonometric measurements and compared to baseline values, after 6 h, epinephrine infusion was associated with an increase in lactate levels (from 3.1 +/- 1.5 to 5.9 +/- 1.0 mmol/l;p < 0.01), while lactate levels decreased in the norepinephrine-dobutamine group (from 3.1 +/- 1.5 to 2.7 +/- 1.0 mmol/l). The lactate/pyruvate ratio increased in the epinephrine group (from 15.5 +/- 5.4 to 21 +/- 5.8; p < 0.01) and did not change in the norepinephrine-dobutamine group (13.8 +/- 5 to 14 +/- 5.0). Gastric mucosal pH (pHi) decreased (from 7.29 +/- 0.11 to 7.16 +/- 0.07; p < 0.01) and the partial pressure of carbon dioxide (PCO2) gap (tonometer PCO2-arterial PCO2) increased (from 10 +/- 2.7 to 14 +/- 2.7 mmHg; p < 0.01) in the epinephrine group. In the norepinephrine-dobutamine group pHi (from 7.30 +/- 0.11 to 7.35 +/- 0.07) and the PCO2 gap (from 10 +/- 3.0 to 4 +/- 2.0 mmHg) were normalized within 6 h (p < 0.01). The decrease in pHi and the increase in the lactate/pyruvate ratio in the epinephrine group was transient, since it returned to normal within 24 h. CONCLUSIONS: Considering the global hemodynamic effects, epinephrine is as effective as norepinephrine-dobutamine. Nevertheless, gastric mucosal acidosis and global metabolic changes observed in epinephrine-treated patients are consistent with a markedly inadequate, although transient, splanchnic oxygen utilization. The metabolic and splanchnic effects of the combination of norepinephrine and dobutamine in hyperdynamic dopamine-resistant septic shock appeared to be more predictable and more appropriate to the current goals of septic shock therapy than those of epinephrine alone.

Adrenergic beta-Antagonists↗

Is endotoxin and cytokine release related to a decrease in gastric intramucosal pH after hemorrhagic shock?

OBJECTIVES: (a) To investigate the relationship between gut ischemia parameters (gastric intramucosal pH [pHi], mucosal-arterial carbon dioxide difference [PCO2-gap]), and endotoxin or cytokine release during hemorrhagic shock; (b) to compare the predictive value of pHi, PCO2-gap and arterial lactate concentrations. DESIGN: Prospective study. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: 20 multiple trauma patients with severe hemorrhagic shock. INTERVENTIONS: Intramucosal measurements and blood samples were obtained on admission to the emergency room and repeatedly over 48 h. MEASUREMENTS AND RESULTS: Endotoxin was measured using a chromogenic limulus amoebocyte assay. Cytokine [tumor necrosis factor-alpha (TNF alpha) and interleukin-6 (IL-6)] values were evaluated by immunoradiometric assays. Only 3 patients had positive blood cultures but endotoxins were detected at least once in all patients. Endotoxin levels were similar in survivors and non-survivors over the study period and were not related to pHi or PCO2-gap. Initially, high levels of IL-6 were observed in both nonsurvivors and survivors [median 1778 pg/ml (range 435-44,540) vs 2068 pg/ml (range 996-92,300)]. IL-6 levels progressively decreased in the survivors but not significantly. On admission, TNF alpha concentrations were similar in nonsurvivors and survivors (42 +/- 35 vs 46 +/- 27 pg/ml). From the 24th h, TNF alpha values were higher in the nonsurvivors than in the survivors (24 h: 72 +/- 38 vs 34 +/- 17 pg/ml, p < 0.05). The greatest IL-6 levels were found for a pHi < 7.20 (28.5 +/- 36.5 vs 1.8 +/- 1.3 ng/ml, p < 0.05) or a PCO2-gap > 7.5 mmHg (1 kPa) (32.5 +/- 37.5 vs 1.7 +/- 1.3 ng/ml, p < 0.01). With the same pHi threshold, no difference was found in endotoxin levels. The lactate concentrations were predictive for outcome from the 12th h (9.5 +/- 5.9 vs 3.6 +/- 2.3 mmol/l, p < 0.05). CONCLUSIONS: During severe hemorrhagic shock, endotoxin translocation from the gut was a common phenomenon that seemed independent of both pHi values and outcome. It could not explain IL-6 and TNF alpha release. In severe hemorrhagic shock, neither pHi nor PCO2-gap provides additional information to the lactate measurements.

Adult↗

Sleep-related hypoxaemia in chronic obstructive pulmonary disease: causes, consequences and treatment.

Worsening of hypoxaemia during sleep in patients with chronic obstructive pulmonary disease has been extensively investigated in the past 20 years owing to the development of polysomnography and to the advent of reliable transcutaneous oximeters. Sleep-related hypoxaemia is characteristic of rapid-eye-movement (REM) sleep but may be present during other sleep stages. There is a strong relationship between nocturnal O2 saturation and the level of daytime PaO2: the more pronounced daytime hypoxaemia, the more severe nocturnal hypoxaemia. Sleep-related hypoxaemia is due to a variable combination of alveolar hypoventilation and ventilation-perfusion mismatching, alveolar hypoventilation being the preponderant mechanism during REM sleep. The deleterious effects of sleep-related hypoxaemia include cardiac arrhythmias, 'hypoxaemic stress' on the coronary circulation and especially, peaks of pulmonary hypertension. The treatment of nocturnal hypoxaemia is conventional O2 therapy (both nighttime and daytime) in patients who exhibit marked daytime hypoxaemia (PaO2 < 55-60 mm Hg). At present data are not sufficient for justifying the use of isolated nocturnal O2 therapy in patients with nocturnal desaturation who do not qualify for conventional O2 therapy.

Clinical Trials as Topic↗

Sleep-related O2 desaturation and daytime pulmonary haemodynamics in COPD patients with mild hypoxaemia.

It has been hypothesized but not firmly established that sleep-related hypoxaemia could favour the development of pulmonary hypertension in chronic obstructive pulmonary disease (COPD) patients without marked daytime hypoxaemia. We have investigated the relationships between pulmonary function data, sleep-related desaturation and daytime pulmonary haemodynamics in a group of 94 COPD patients not qualifying for conventional O2 therapy (daytime arterial oxygen tension (Pa,O2) in the range 7.4-9.2 kPa (56-69 mmHg)). Nocturnal desaturation was defined by spending > or = 30% of the recording time with a transcutaneous O2 saturation < 90%. An obstructive sleep apnoea syndrome was excluded by polysomnography. Sixty six patients were desaturators (Group 1) and 28 were nondesaturators (Group 2). There was no significant difference between Groups 1 and 2 with regard to pulmonary volumes and Pa,O2 (8.4+/-0.6 vs 8.4+/-0.4 kPa (63+/-4 vs 63+/-3 mmHg)) but arterial carbon dioxide tension (Pa,CO2) was higher in Group 1 (6.0+/-0.7 vs 53+/-0.5 kPa (45+/-5 vs 40+/-4 mmHg); p<0.0001). Mean pulmonary artery pressure (Ppa) was very similar in the two groups (2.6+/-0.7 vs 2.5+/-0.6 kPa (19+/-5 vs 19+/-4 mmHg)). No individual variable or combination of variables could predict the presence of pulmonary hypertension. It is concluded that in these patients with chronic obstructive pulmonary disease with modest daytime hypoxaemia, functional and gasometric variables (with the noticeable exception of arterial carbon dioxide tension) cannot predict the presence of nocturnal desaturation; and that mean pulmonary artery pressure is not correlated with the degree and duration of nocturnal hypoxaemia. These results do not support the hypothesis that sleep-related hypoxaemia favours the development of pulmonary hypertension.

Aged↗

Metabolic intermediates in lactic acidosis: compounds, samples and interpretation.

A number of acquired conditions including infections, severe catabolic states, tissue anoxia, severe dehydration and poisoning can give rise to hyperlactacidaemia. All these causes should be ruled out before considering inborn errors of metabolism. Carefully collected samples are necessary if artefacts that result in spuriously increased lactate/pyruvate (L/P) and 3-hydroxybutyrate/acetoacetate (B/A) ratios are to be avoided. When properly performed, 24-h studies of L/P and B/A ratios provide a useful tool in making a diagnosis. A few metabolic profiles when present are specific or highly suggestive of a given disorder. When the L/P ratio is normal or low, pyruvate dehydrogenase (PDH) deficiency is highly probable whatever the lactate concentration, which is often only moderately elevated after meal, may be. When the L/P ratio is very high in association with post-prandial hyperketonaemia and in contrast to a normal or low B/A ratio, pyruvate carboxylase (PC) deficiency and alpha-ketoglutarate dehydrogenase (KGDH) deficiency are the most likely diagnoses. The distinction between the two disorders relies upon amino acid and organic acid profiles (glutamate and alpha-ketoglutarate accumulations in KGDH deficiency and hyperammonaemia and hypercitrullinaemia in PC deficiency). When both L/P and B/A ratios are elevated and associated with significant post-prandial hyperketonaemia, respiratory-chain disorders should first be suspected. All other profiles, especially a high L/P ratio without hyperketonaemia, are compatible with respiratory-chain disorders but are not specific; all acquired anoxic conditions should also be ruled out. Clearly, the clinical utility of these profiles needs to be interpreted cautiously in very ill patients in relation to the cardiocirculatory condition and to therapy. Finally, a normal profile, even after stress and loading, does not rule out an inborn error of lactate/pyruvate oxidation.

Acidosis, Lactic↗

Clinical outcome and long-term management of 17 patients with propionic acidaemia.

UNLABELLED: A retrospective study was performed on the clinical outcome and long-term treatment of 17 patients with propionic acidaemia diagnosed during the last 20 years in our hospital. The study group consisted of 12 patients with early onset type of disease and 5 patients with late onset. Seven (41%) patients died, five with early onset and two with late onset. The deceased early onset patients had a median survival of 0.4 years while the deceased late onset patients died at the age of 2.8 and 4 years respectively. Median age of the living early onset patients was 5.2 (1-9.25) years, the late onset patients were 4, 7 and 23 years old. Patients were all treated with natural protein restriction and in most cases carnitine and metronidazole were added. The early onset patients were almost all treated with daily home tube feeding. The mean natural protein intake of early onset patients (6.3 +/- 1.5 g/day) was significantly lower than the natural protein intake of late onset patients (17.6 +/- 5.3 g/day). Supplemental protein intake was higher in early onset patients. The general neurological outcome of our study group was satisfactory with a better outcome for early onset patients. As to growth, many patients showed a failure to thrive, this was particularly for height. The strong protein restriction during the first years of life probably contributed to this. CONCLUSION: The prognosis for patients with propionic acidaemia appeared to be satisfactory in terms of survival and outcome characteristics such as neurological and mental development. Despite these results the authors feel that the prognosis and quality of life of these patients might be improved with liver transplantation or possibly somatic gene therapy in the future.

Adolescent↗

[Analgesia after laparoscopic cholecystectomy by intraperitoneal administration of bupivacaine].

OBJECTIVES: The aims of this study were to assess the analgesic effect of the intraperitoneal topical administration of 0.375% bupivacaine in patients undergoing laparoscopic cholecystectomy and to carry out a pharmacokinetic study of bupivacaine administered topically by intraperitoneal route. STUDY DESIGN: Randomized, double-blind controlled trial. PATIENTS AND METHODS: Twenty-four patients of ASA physical status 1 or 2, undergoing elective laparoscopic cholecystectomy, were included. Anaesthesia technique was the same for all patients. At the end of surgery, they were randomly assigned to one of two groups. Patients in group bupivacaine were administered 0.375% bupivacaine, 0.6 mL.kg-1 intraperitoneally in both subdiaphragmatic areas and the cholecystectomy wound, those of the control group were given the same volume of NaCl 0.9%. Analgesia was provided by morphine PCA. Postoperative pain, assessed on a 100 mm visual analogue pain scale (VAS), and administered morphine were recorded 30 min after extubation, and 0.5, 1, 2, 3, 6, 12, 24, 36 and 48 hours later. Blood samples were collected 2, 5, 15, 30, 60, 90, 120, 180, 300 and 480 min after the intraperitoneal administration of bupivacaine to measure bupivacaine plasma concentration. Statistics included Student t test and Chi square test. P < 0.05 was considered significant. RESULTS: There was no significant difference between the two groups with regard to VAS scores during the first 48 postoperative hours. Morphine requirements (total and at each point) were also similar. Plasma bupivacaine concentrations reached a plateau at 10-20 min, and then decreased slowly. The median plasma peak concentration was 0.94 +/- 0.47 microgram.mL-1. In one patient toxic concentrations (> 1.6 micrograms.mL-1) during the first 60 min after intraperitoneal administration were obtained, while in another patient a concentration of 1.58 micrograms.mL-1 was reached twice. CONCLUSIONS: Intraperitoneal administration of 0.6 mL.kg-1 of 0.375% bupivacaine is ineffective in reducing postoperative pain after laparoscopic cholecystectomy. Furthermore these high doses of bupivacaine may result in toxic plasma concentrations. This technique is not safe and cannot be recommended.

Adult↗

[Chylothorax following closed thoracic injury].

Chylothorax following blunt chest trauma is a rare event. The presence of a cloudy or milky persistent pleural effusion should suggest the possibility of its chylous origin. The diagnosis is made by analysis of the fluid obtained either from thoracentesis or tube thoracostomy. A lymphangiogram can show the site of the lesion, but computed tomography is a more recent and probably as helpful diagnostic test. An efficient control of the chylous effusion may be facilitated by using a fat-poor enteral nutrition and parenteral nutrition, which prevents malnutrition. Surgical ligation of the thoracic duct is relatively simple and efficient. It is indicated when the daily chylous flow is over 500 mL after 2 or 3 weeks of medical treatment or in case of weight loss.

Adult↗

[Treatment of post-traumatic acute anemia by recombinant human erythropoietin in Jehovah's Witnesses].

A 20-year-old Jehovah's witness patient experienced a femur fracture, with a section of the femoral artery and vein. On admission, haemoglobin concentration was 5.6 g.dL-1 and haematocrit 17%. Because of aponevrotomy, blood losses persisted. As the patient refused blood transfusion, recombinant human erythropoietin and parenteral iron were administered, associated with mild hypothermia, sedation and mechanical ventilation. After 21 days, the haemoglobin concentration increased to 10.9 g.dL-1 and haematocrit to 33% Recombinant human erythropoietin and parenteral iron may provide an alternative safe and effective therapy in life-threatening anaemia when blood transfusions are not accepted by the patient.

Acute Disease↗

[Sleep and COPD].

In COPD patients hypoxaemia does worsen during sleep and particularly during REM sleep. However, severe sleep-related O2 desaturation is only observed in patients who exhibit a marked daytime hypoxaemia. Nocturnal desaturation is due to the combination of alveolar hypoventilation and ventilation-perfusion mismatch; alveolar hypoventilation is the predominant mechanism, at least during REM sleep. Sleep-related hypoxaemia leads to peaks of pulmonary hypertension but also to cardiac arrhythmias. Hypoxaemia can be particularly severe when COPD is associated with a sleep apnoea syndrome (this association is rather frequent). A severe nocturnal desaturation needs a treatment with prolonged oxygen therapy, especially if daytime hypoxaemia (PaO2 < 55-60 mmHg) is present. The real benefit from oxygen therapy limited to sleep time in nocturnal desaturators who have not a significant daytime hypoxaemia, has not been yet demonstrated.

Humans↗

[Outcome of the use of albumin and colloid plasma substitutes from 1989 to 1993 in a French University Hospital Center].

OBJECTIVES: To evaluate the use of plasma substitutes (albumin, gelatins, dextrans, starches) from 1989 to 1993 in a 3000-bed University hospital and to assess the impact of the 1989 consensus conference of the French speaking Society of Intensive Care Medicine on the choice of plasma substitutes for treatment of hypovolaemia. STUDY DESIGN: Retrospective study of a case series. METHODS: Data on the use of albumin and artificial plasma substitutes were obtained from Blood Bank and Pharmacy. RESULTS: Between 1989 and 1993, the total amount of administered plasma substitutes decreased by 20%, allowing a saving of 1.7 million FF. There was a 60% decrease in the use of gelatins and dextrans. The starches, introduced in 1991, became in 1993 the most used plasma substitute, with 37% of the total. The use of albumin showed only a 32% decrease and was still in 1993 the main source of expenditure for plasma substitutes, with 3.8 million FF and 80% of the total cost. The number of plasmapheresis increased by 15%, whereas the use of albumin for plasmapheresis, almost constant in absolute value, increased from 31% in 1989 to 45% in 1993 of the total expenses. There were large differences between the services regarding the use of albumin. Intensive care and surgical units represented 70% of the total (plasmapheresis excluded). In this group, the overall fall of use was 22%, some units obtaining a 93% decrease whereas other did not change in spite of constant admission numbers. Medical units decreased their albumin use by 53%. CONCLUSION: The decrease in the albumin use between 1989 and 1993 was not significant. The impact of the consensus conference, if any, was weak. A careful evaluation of the prescriptions would be necessary to improve the compliance of clinical practice with recommendations by the consensus conference.

Albumins↗

Prognostic factors in COPD patients receiving long-term oxygen therapy. Importance of pulmonary artery pressure.

Prognostic factors in COPD patients receiving long-term oxygen (LTO) therapy were recently analyzed, but very few studies considered the prognostic value of pulmonary artery pressure (PAP) in these patients. We investigated 84 patients who had undergone a right heart catheterization just before the onset of LTO. There were 75 men and 9 women, with a mean age of 63.0 +/- 9.9 (SD) years, at the onset of LTO. When PaO2 was persistently less than 55 mm Hg, LTO was initiated. This therapy was started in some patients with PaO2 in the range of 55 to 60 mm Hg if they had signs of cor pulmonale or a resting PAP of 25 mm Hg or greater at right heart catheterization. The daily duration of LTO was 16 h/d or more. Oxygen flow was adapted to achieve a PaO2 of 65 mm Hg or more. The patients were subdivided into subgroups according to the median value of age (cutoff value = 63 years); vital capacity (2,250 mL); FEV1 (800 mL); residual volume-total lung capacity ratio (58%); PaO2 value (52 mm Hg), PaCO2 level (45 mm Hg); and PAP (25 mm Hg). The cumulative 5-year survival rate was 48% for the group as a whole. Actuarial survival curves were plotted for the two subgroups of patients subdivided according to the initial median value of the variables just listed. There was no significant difference in survival rate between subgroups except when taking into account the level of PAP and age. In patients with an initial PAP of 25 mm Hg or less (n = 44), the 5-year survival was of 62.2 vs 36.3% in the remainder (n = 40) [p < 0.001]. We performed a multivariate analysis of survival using Cox's model of the proportional hazards regression including sex and the variables with the same categorization in the stepwise procedure: PAP and age were the only variables included in the final model. We conclude that the best prognostic factor in COPD patients receiving LTO is not the FEV1, nor the degree of hypoxemia or hypercapnia, but the level of PAP.

Actuarial Analysis↗

Relationship between ethanol tolerance, lipid composition and plasma membrane fluidity in Saccharomyces cerevisiae and Kloeckera apiculata.

The lipid composition of a strain of each of two yeasts, Saccharomyces cerevisiae and Kloeckera apiculata, with different ethanol tolerances, was determined for cells grown with or without added ethanol. An increase in the proportion of ergosterol, unsaturated fatty acid levels and the maintenance of phospholipid biosynthesis seemed to be responsible for ethanol tolerance. The association of ethanol tolerance of yeast cells with plasma membrane fluidity, measured by fluorescence anisotropy, is discussed. We propose that an increase in plasma membrane fluidity may be correlated with a decrease in the sterol:phospholipid and sterol:protein ratios and an increase in unsaturation index.

Bacterial Proteins↗