Metformin as a protective agent against natural or chemical toxicities: a comprehensive review on drug repositioning.

BACKGROUND: Metformin is the first prescribed drug for hyperglycemia in type 2 diabetes mellitus. Mainly by activating AMPK pathway, this drug exerts various functions that among them protective effects are of the interest. PURPOSE: Herein, we aimed to gather data about the protective impacts of metformin against various natural or chemical toxicities. RESULTS: An extensive search among PubMed, Scopus, and Google Scholar was conducted by keywords related to protection, toxicity, natural and chemical toxins and, metformin. Our literature review showed metformin alongside its anti-hyperglycemic effect has a wide range of anti-toxic effects against anti-tumour and routine drugs, natural and chemical toxins, herbicides and, heavy metals. CONCLUSION: It is evident that metformin is a potent drug against the toxicity of a broad spectrum of natural, chemical toxic agents which is proved by a vast number of studies. Metformin mainly through AMPK axis can protect different organs against toxicities. Moreover, metformin preserves DNA integrity and can be an option for adjuvant therapy to ameliorate side effect of other therapeutics.

Unexpectedly long half-life of metformin elimination in cases of metformin accumulation.

INTRODUCTION: In a study of the oral administration of a single dose of metformin to healthy participants, the estimated half-life (t½ ) for the elimination of the drug from erythrocytes was found to be 23.4 h (compared with 2.7 h for metformin in plasma). However, these pharmacokinetic indices have not been well defined in metformin accumulation. METHODS: We systematically reviewed all the data on plasma and erythrocyte metformin assays available in our centre. We then selected patients with a plasma metformin concentration ≥ 5 mg/l and in whom the metformin concentration had been remeasured once or more at least 5 days after admission. RESULTS: Twelve patients met the aforementioned criteria. All but one of these patients displayed generally severe lactic acidosis on admission (mean ± sd pH and lactate: 6.88 ± 0.35 and 14.8 ± 6.56 mmol/l, respectively) and 11 were treated with dialysis. The mean ± sd time interval between the first and last blood sample collections for metformin measurement was 8.3 ± 3.2 days (range 5-14 days). Five days after the first sample had been collected, metformin was still detectable in plasma and in erythrocytes in all patients. Metformin remained detectable for up to 13 days (both in plasma and in erythrocytes). The estimated mean terminal t½ for metformin in plasma and erythrocytes was 51.9 and 43.4 h, respectively. CONCLUSIONS: The prolonged elimination of accumulated metformin (even after dialysis therapy) challenges the traditional view that the drug clears rapidly because of a short half-life in plasma.

The relationship between metformin therapy and sleep quantity and quality in patients with Type 2 diabetes referred for potential sleep disorders.

AIMS: Given that sleep disorders are known to be related to insulin resistance, and metformin has favourable effects on insulin resistance and on ventilatory drive, we sought to determine whether metformin therapy was related to sleep variables in a group of patients with Type 2 diabetes. METHODS: We performed a retrospective, observational study of our centre's database for patients referred for potential sleep disorders and then compared metformin-treated patients with those not treated with the drug. All study patients had undergone the same standard polysomnographic procedure. A multivariate analysis was performed to establish whether or not there was an independent relationship between metformin use and sleep variables (after adjusting for age, gender, BMI, neck circumference, cumulated risk factors and insulin use). RESULTS: We studied 387 patients (mean ± sd age: 58.4 ± 10.8 years), of whom 314 had been treated with metformin. Total sleep time and sleep efficiency were higher in metformin-treated patients than in patients not treated with metformin [total sleep time: 6 h 39 min vs. 6 h 3 min, respectively (P = 0.002); sleep efficiency: 77.9 ± 12.3 vs. 71.5 ± 17.2%, respectively (P = 0.003)]. These differences persisted after adjustment for covariates and were observed even although metformin users had a higher BMI than did non-users (median 37.5 vs. 34.8 kg/m(2) ; P = 0.045). CONCLUSION: We showed that metformin therapy is associated with a longer sleep duration and better sleep efficiency. Randomized clinical trials are needed to confirm metformin's favourable effect on sleep quality and quantity.

The criteria for metformin-associated lactic acidosis: the quality of reporting in a large pharmacovigilance database.

AIMS: To study the quality of pharmacovigilance reporting in cases of so-called 'metformin-associated lactic acidosis' and, ultimately, whether or not the criteria for this condition are indeed met. METHODS: We searched for cases meeting the criteria for metformin-associated lactic acidosis [arterial pH < 7.35, blood lactate > 5 mmol/l (45 mg/dl) and detectable plasma metformin concentration] in a 15-year period (1995-2010) in a pharmacovigilance database of the license holder for metformin (Merck Serono, Lyon, France). RESULTS: We found 869 reports stated as 'metformin-associated lactic acidosis' from 32 countries. The respective criteria for pH, lactate concentration and metformin concentration were met in 51.2, 53.3 and 13.9% of cases. All three criteria were met in just 10.4% of cases. By year, each of the percentages remained roughly stable throughout the study period. CONCLUSIONS: The role of metformin in triggering metformin-associated lactic acidosis was assessed incorrectly in most patients and the quality of reporting did not improve over time.

Effect of metformin on survival rate in experimental sepsis.

AIM: Because "metformin-associated lactic acidosis" refers to metformin and concurrent pathologies as co-precipitating factors, the respective impact in the outcome of metformin therapy, metformin accumulation, and general diseases should be determined. We therefore constructed a model of sepsis in mice treated with metformin at a dose corresponding to clinical practice, or to accumulation. METHODS: 460 mice were separated in 3 groups: no metformin therapy, a 7-day metformin therapy at 50 mg.kg(-1).day(-1) (MET50) or 500 mg.kg(-1).day(-1) (MET500). Blood was drawn on day 7 in 40 metformin-treated animals for determining metformin concentrations. The 420 other mice were divided in 14 subgroups according to the amount of an intra-peritoneal inoculum of E. coli ranging from 5.103 to 1010 CFU/ml in order to construct a lethal dose curve. The survival rate was assessed at 7, 13, 24, 36, 60 and 120 hours thereafter. RESULTS: Plasma metformin concentrations were 0.26 +/- 0.13 mg/l in MET50, and 4.63 +/- 1.92 mg/l in MET500. The comparative analysis of the survival rates at 120 hours showed no difference of mortality, always occurring for an inoculum amount > 10(8) CFU/ml. Comparing the survival rates from time 0 to 120 hours using Kaplan-Meyer curves and the Logrank test, there was no difference between the different groups. CONCLUSION: Metformin, even at a dose mimicking accumulation, does not aggravate the mortality rate in this model of sepsis. Consequently, metformin can not be considered as toxic in such a condition.

Role of metformin accumulation in metformin-associated lactic acidosis.

OBJECTIVE: To investigate the role of metformin accumulation in the pathophysiology of metformin-associated lactic acidosis. RESEARCH DESIGN AND METHODS: We used high-performance liquid chromatography to measure plasma metformin concentrations in 14 patients who experienced lactic acidosis (pH < 7.35 and lactate concentration 5 > mmol/l) while receiving chronic metformin treatment. Their treatment was generally based on alkalinization and dialysis therapy. RESULTS: Clinical shock and/or evidence of tissue hypoxia was found in all patients with the exception of one who had a nonsteroidal anti-inflammatory drug-induced anuria. Ten patients had significant metformin accumulation (plasma metformin concentrations 4.1-84.9 mg/l, normal value 0.6 +/- 0.5 mg/l before drug intake), generally because of failure to withdraw metformin despite intercurrent pathological conditions affecting its renal elimination (serum creatinine concentrations ranging from 269 to 1,091 mumol/l). There was no metformin accumulation (plasma metformin 0.03-0.7 mg/l) in the four other patients, who had less severe renal failure (serum creatinine 140-349 mumol/l). The severity of the patient's general condition did not predict early hospital mortality (death before discharge from the intensive care unit) even in patients in shock. Whereas it was high in those without metformin accumulation (only 1 of 4 patients recovered), early hospital mortality was low in the 10 patients with metformin accumulation and was not related to its extent (3 patients died with end-stage hepatic failure or cardiac failure). Correlation studies showed a positive correlation between serum creatinine and plasma metformin and between plasma metformin and arterial lactate but, for the latter correlation, only in patients with metformin accumulation. CONCLUSION: Metformin-associated lactic acidosis is not necessarily due to metformin accumulation; true type B (aerobic) lactic acidosis, i.e., without an apparent associated hypoxic factor, seems exceptional. Neither the severity of the clinical picture nor the degree of metformin accumulation predicted survival; rather, the prognosis was dependent upon the severity of the associated pathological conditions.

Somatostatin analogs for the localization and preoperative treatment of an adrenocorticotropin-secreting bronchial carcinoid tumor.

The diagnosis of the ectopic ACTH syndrome often remains difficult. Although bilateral inferior petrosal sinus sampling has recently offered a new approach, it does not help to localize an occult nonpituitary tumor. We report the case of a 45-yr-old woman whose hypercortisolism highly suggested the ectopic ACTH syndrome: elevated urinary free cortisol (3234 nmol/day, normal 28-143) was not suppressed by the high-dose dexamethasone test (2789 nmol/day); increased plasma ACTH (21.8 pmol/L, normal 2-11.4) did not respond to the ovine CRH test (23.8 pmol/L); and pituitary magnetic resonance imaging was negative. The thorax computed tomographic scan showed a questionable 7-mm nodular lesion in the upper part of the left lung. Because a 3-day trial of octreotide administration (200 micrograms sc every 8 h) induced a dramatic clinical and biological response with a drop in urinary free cortisol from 1738 to 441 nmol/day we performed a scintigraphy with [111In]pentetreotide; it revealed a single-well limited area of abnormal uptake at the exact location of the suspected thoracic lesion. This nodule was removed surgically after preparation of the patient by a 1-month treatment with octreotide: the tumor proved to be a typical bronchial carcinoid, containing extremely high concentrations of immunoreactive ACTH (198 pmol/mg wet wt tissue) and POMC messenger RNA by Northern blot. The presence of somatostatin receptors in the tumor was confirmed by in vitro radioautography. After surgery plasma cortisol and ACTH were undetectable. Somatostatin radioanalog scintigraphy should be considered as a new investigative tool in patients with suspected ectopic ACTH syndrome.

Lactic acidosis in metformin therapy.

The biguanide drugs metformin and phenformin have been linked in the past to lactic acidosis, a metabolic condition associated with high rates of mortality. Although concern over the hyperlactataemic effect of phenformin led to the withdrawal of this drug from clinical practice in the 1970s, the situation with metformin has been less clear. Retrospective data indicate that, in metformin-treated patients with lactic acidosis, neither the degree of hyperlactataemia nor accumulation of metformin is of prognostic significance. Furthermore, the lowest rates of mortality were seen in patients with high plasma concentrations of metformin, which has led to the hypothesis that the drug may confer some benefit, linked to an increase in vasomotility, in such cases. Overall, it appears that mortality in patients receiving metformin who develop lactic acidosis is linked to underlying disease rather than to metformin accumulation, and that metformin can no longer be considered a toxic drug in this respect. These findings are likely to be of considerable relevance to the management of patients with type 2 (non-insulin-dependent) diabetes mellitus, especially where such patients are elderly.

Calcium metabolism, plasma parathyroid hormone, and calcitriol in transient hypertension of pregnancy.

In order to know if abnormalities of calcium metabolism may be involved in the pathophysiology of pregnancy-induced hypertension (PIH), as it has been incriminated in essential hypertension, we measured plasma and urinary calcium and phosphate as well as plasma PTH and free calcitriol index (ratio of total calcitriol on the D binding protein) in normotensive pregnant women (n = 25), in women with PIH after the same duration of amenorrhea (> 28 wk, n = 21:preeclampsia and 20 transient hypertensions), and in age-matched nonpregnant women (n = 15). The severity of PIH was mild since blood uric acid was not increased and plasma volume, measured with the Evans blue technique, was found only moderately decreased (-10.5 +/- 3.1% of normal value). The results show that normotensive pregnant women showed the expected increase of the vitamin D parameters in comparison to nonpregnant controls. Hypertensive pregnant women were not different from the normotensive ones regarding plasma corrected calcium and phosphate and urinary excretion of calcium and phosphate, but had higher plasma PTH (13 +/- 1 v 8.8 +/- 1.6 pg/mL) and lower total and free calcitriol index (86 +/- 7 v 110 +/- 6 pg/mL and 1.72 +/- 0.10 v 2.25 +/- 0.13 x 10(-5)). Correlative studies showed PIH having a negative correlation between blood pressure and plasma corrected calcium (r = -0.43, P < .05), which is in agreement with epidemiological studies of essential hypertension. In conclusion, disturbances of calcium regulating hormones do exist in transient forms of pregnancy-induced hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Myxoedema coma: response of thyroid hormones with oral and intravenous high-dose L-thyroxine treatment.

Myxoedema coma is a medical emergency with high mortality. In this study, clinical response and plasma variations of thyroid hormones were analysed in 7 patients, 6 presenting with myxoedema coma and one with myxoedema ileus. These patients were treated with intravenous or oral l-thyroxine (l-T4). 1000 mu l-T4 iv were administered in two patients. Within 3 h, plasma T4 and triiodothyronine (T3) reached a peak upper normal range, then diminished slowly during 5-9 days. The 5 remaining patients were treated with 500 micrograms l-T4 po on the first day, then 100 micrograms l-T4 daily by mouth. Plasma T4 and T3 increased slowly, remaining in hypothyroid range but clinical response (assessed on mental status, pulse rate and body temperature) occurred within 24-72 h. Cortisone therapy was used in 3 patients. Two patients died of myocardial infarction, or septicemia, one while receiving cortisone therapy and i.v. l-T4, another one treated only by oral l-T4. This study suggests: 1) oral absorption of l-T4 is variable, but clinical response occurs quickly even in myxoedema ileus; 2) the intravenous route involves high peaks of plasma T4 and T3; 3) peripheral conversion of T4 to T3 allows gradually T3 delivery to organ systems, even if only l-T4 is used and 4) initial and daily dosage determinations need further studies.

Pancreatitis related to severe acute hypertriglyceridemia during pregnancy: treatment with lipoprotein apheresis.

We report a clinical observation of acute pancreatitis due to severe hypertriglyceridemia in a pregnant woman. In order to decrease the serum triglyceride level rapidly, two lipaphereses were undertaken using the double-filtration technique. This lipoprotein apheresis technique is briefly described and the efficacy in reducing rapidly hypertriglyceridemia is outlined. Like in 3 previously published reports, the patient had a rapid recovery, confirming that lipoprotein apheresis should be an adequate and a well-tolerated treatment in such a condition.

Bicarbonate haemodialysis: an adequate treatment for lactic acidosis in diabetics treated by metformin.

Lactic acidosis in diabetics on metformin therapy is rare but still associated with poor prognosis. The authors report here five cases. Three patients were initially with a cardiovascular collapse and all had an acute renal failure. Sodium bicarbonate haemodialysis therapy led to a dramatic improvement. Consciousness and hemodynamic status recovered rapidly. Severe metabolic and blood gases derangements were also rapidly corrected. Plasma metformin removal, appreciated by repeated blood samplings in 3 cases, was satisfactory. All patients survived. However, blood metformin levels remained abnormally high at the end of the dialytic therapy. In conclusion, (1) bicarbonate dialysis is an adequate treatment of lactic acidosis observed in diabetic patients treated with metformin since it rapidly corrects the acid-base disorders and partially removes metformin; (2) the sole accumulation of metformin is not sufficient to explain lactic acidosis since this latter might be corrected in spite of persisting high levels of blood metformin.

Insulin sensitivity, insulin action, and fibrinolysis activity in nondiabetic and diabetic obese subjects.

Because inconsistencies occur with regard to the relative contribution of insulin to the hypofibrinolysis characteristic of obesity and diabetes, we explored the relationship between insulin and fibrinolysis, assessing both insulin sensitivity and insulin action. Seventeen markedly obese subjects (body mass index [BMI], 34.0+/-1.6 kg/m2; 12 nondiabetic and five diabetic) were studied using the three-step euglycemic-hyperinsulinemic clamp technique. Since the circadian rhythm of the fibrinolytic system may obscure a true effect of insulin, variations in fibrinolysis parameters observed during the glucose clamp were compared with those occurring spontaneously because of the circadian rhythm. Compared with six normal-weight subjects (BMI, 21.0+/-0.9 kg/m2), all obese subjects exhibited basal hyperinsulinism (fasting plasma insulin, 16.0+/-1.4 v 9.8+/-1.3 microU/microL, P < .001; fasting plasma C-peptide, 1.4+/-0.2 v 0.5+/-0.2 ng/mL, P < .001), hypofibrinolysis (euglobulin lysis time [ELT], 378+/-29 v 222+/-31 minutes, P=.01; tissue plasminogen activator [tPA] antigen, 7.8+/-0.9 v 4.2+/-0.5 ng/mL, P=.04; plasminogen activator inhibitor type 1 [PAI-1] activity, 22.2+/-2.5 v3.9+/-0.6 AU/mL, P=.004), and marked insulin resistance (M value, ie, the maximal glucose disposal rate, 9.1+/-0.6 v 18.6+/-0.8 mg/(kg x min), P < .001). The M value correlated inversely with tPA antigen (r=-.46, P=.05). During insulin infusion, values for fibrinolysis parameters decreased, but were not different compared with variations due to the circadian rhythm. In conclusion, our findings together with previously reported data reinforce the idea that chronic hyperinsulinism is linked to hypofibrinolysis, but insulin does not seem to acutely regulate the fibrinolysis system.

Lactic acidosis in metformin-treated patients. Prognostic value of arterial lactate levels and plasma metformin concentrations.

OBJECTIVE: The antidiabetic drug metformin has been associated in a small number of patients with lactic acidosis, a serious condition with a poor prognosis. However, because of lack of data, the prognostic significance of hyperlactataemia in metformin-treated patients is not known. METHODS: Data were collected from 49 metformin-treated patients with lactic acidosis (arterial lactate level > or = 5 mmol/L and blood pH < or = 7.35) and available plasma metformin concentration data to investigate the association of arterial lactate levels and plasma metformin concentrations with mortality. RESULTS: The overall mortality rate in this patients sample was 45% and the median arterial lactate level was 13.1 mmol/L. Median lactate levels were similar in patients who survived (13 mmol/L) and those who died (14.3 mmol/L), whereas the median plasma metformin concentration was 3 times higher in patients who survived (20.6 mg/L versus 6.3 mg/L). CONCLUSION: In this, the largest series of metformin-treated patients with lactic acidosis yet reported, 55% of patients survived and these patients had a median arterial lactate level of 13.1 mmol/L. Neither arterial lactate levels nor plasma metformin concentrations were of prognostic significance in relation to mortality in this sample of metformin-treated patients with lactic acidosis. Death in these patients appeared instead to be associated with other hypoxic disease or underlying ill health. These observations suggest that accumulation of metformin may not be as significant with respect to high arterial levels of lactate and their effects as has been traditionally thought.

Inhibition of aromatase activity during pregnancy affects sex-related adrenocorticotropic hormone release in response to ether-inhalation in juvenile rats.

The pituitary release of adrenocorticotropic hormone (ACTH) induced by ether inhalation was investigated on day 30 postpartum in male and female young rats from mothers treated daily with the aromatase inhibitor ATD (1,4,6-androstatriene 3,17-dione) from day 17 to day 21 of gestation, in males from mothers injected daily with solvent during the same period of gestation. In spite of a surge in plasma testosterone levels at birth, the males from ATD-treated mothers showed on day 30 postpartum a pituitary response characteristic of the females and not of the males. Thirty minutes after the end of the ether inhalation, the males from ATD-treated mothers showed a surge in plasma ACTH similar to that of littermate females but significantly higher than that of males from solvent-treated mothers. These data suggest that the aromatization of endogenous testosterone to estrogens during the critical period of the fetal life, when a transient surge of plasma testosterone was observed, has a significant organizational effect on the sexually dimorphic ACTH response to the ether stress.

Kinetics of plasma and erythrocyte metformin after acute administration in healthy subjects.

OBJECTIVES: Although the existence of a deep compartment for metformin has long been hypothesized, there is still little direct information concerning metformin distribution in individual tissues in man. The only available study involves chronic metformin therapy. In that study, the measurement of metformin in erythrocytes provided a reliable indicator of metformin distribution and of potential accumulation. To determine the kinetics of metformin in plasma and in erythrocytes after acute oral administration, we performed the present study in healthy subjects after a single oral dose of metformin and compared the pharmacokinetics parameters in erythrocytes to those in plasma. METHODS: Six nondiabetic participants took the study dose of 850 mg metformin at 8: 00 AM after a non-standardized breakfast (i.e., as recommended in clinical practice). Blood samples were collected for metformin measurement in plasma and in erythrocytes at 0, 1, 2, 3, 4, 6, 9, 24, 33, 48, 57, and 72 h. RESULTS: Maximum metformin concentration was attained at 3.0 +/- 0.3 h in plasma and 4.7 +/- 0.5 h in erythrocytes. This difference was not significant. Metformin concentrations peaked at a maximum almost 6 times higher in plasma than in erythrocytes (1.7 +/- 0.1 and 0.3 +/- 0.0 mg/l, respectively). However, because the elimination half-life of metformin was much longer in erythrocytes (23.4 +/- 1.9 h vs. 2.7 +/- 1.2 h), there was no difference in area under the curve between plasma and erythrocytes. The distribution volume (plasma) was calculated to be 146 +/- 11 l. Plasma and erythrocytes concentration-time curves showed that metformin was not detectable in plasma 24 hours after the oral administration, while it remained detectable in erythrocytes up to 48 hours. Metformin concentrations crossed approximately 13 hours after having reached their maximum values in plasma, approximately 16 h after metformin intake. CONCLUSION: Having demonstrated the rapid elimination of metformin from plasma and its slow disappearance from erythrocytes, the presents results should contribute to adjustment of metformin dosage to renal function, assessment of drug compliance, and retrospective analysis (when blood samples are drawn with delay) of the link between metformin and development of lactic acidosis. Most importantly, the present findings should help to ascertain the optimal dosage of metformin, particularly in elderly patients.

Metformin retention independent of renal failure in intestinal occlusion.

Metformin is eliminated by the kidneys, and metformin accumulation has always been noticed in oligo-anuric patients. We have reported an exception to the rule with the case of a metformin-treated patient having metformin accumulation contrasting with a mild increase in serum creatinine in the context of a volvulus of the sigmoid colon. This case prompted us to examine the association between intestinal occlusion and plasma metformin concentrations. For this purpose, we developed an experimental animal model of mechanical obstruction of the intestine. Rats were pre-treated during 3 weeks via drinking solution at a dose of approximately 100 mg/kg/day of metformin. They underwent at day 0 either sham-operation (n=7) or operation (n=8) to place a plastic tube around the ileum near the ileocaecal valve. Metformin administration was pursued on days 1, 2, and 3 giving a single dose of 100 mg/kg by intragastric gavage. Four days after the surgery, i.e. 24 h after the last metformin administration, the surviving intestinal obstructed rats (n=8) developed overt intestinal dilation but no biochemical abnormality compared to sham-operated animals (n=7; arterial lactate concentrations respectively 4.87 +/- 0.63 mmol/l and 3.97 +/- 0.30 mmol/l, NS, and serum creatinine concentrations 69.0 +/- 1.7 micromol/l and 68.7 +/- 1.9 micromol/l, NS). By contrast, there was a striking difference with regard to metformin concentrations, decreasing from 2.95 +/- 0.94 mg/l at day 0 to 0.12 +/- 0.03 mg/l at day 4 (p<0.001) in the sham-operated group but remaining unchanged (1.65 +/- 0.76 mg/l and 1.61 +/- 0.51 mg/l) in the operation group. In conclusion, this is the first experiment showing that intestinal occlusion may be responsible for metformin retention in the absence of renal failure. Whether this observation may be relevant to other drugs remains to be established.

Efficacy and tolerance of calcium alginate versus vaseline gauze dressings in the treatment of diabetic foot lesions.

BACKGROUND: The study aimed at comparing the efficacy and tolerance of an alginate wound dressing with a vaseline gauze dressing in the treatment of diabetic foot lesions. METHODS: This open-label randomized multicenter controlled study was designed to assess the effect of an up to 6-week treatment with either calcium alginate or vaseline gauze dressings. Lesions were either acute or chronic, under cleansing, and with a surface area of 1-50 cm(2); osteomyelitis and severe hypovascularization were non-inclusion criteria. Dressings were changed every day then, once granulation had occurred, every 2 to 3 days. Primary outcome was the proportion of patients with granulation tissue over 75% of the wound area and having a 40% decrease in wound surface area; secondary outcomes were pain on dressing changes, the number of dressing changes, and adverse events. RESULTS: Seventy-seven patients were enrolled. Due to the premature cessation of treatment in 13 patients, it was decided to reduce the period of the efficacy analysis to 4 weeks (without revising the criteria of efficacy). The success rate was of 42.8% in the calcium alginate group and of 28.5% in the vaseline gauze group (not significant difference). A subsequent analysis of granulation tissue surfaces covering the wounds at week 4 (all surfaces taken together) showed a superiority of calcium alginate (p=0.04). Pain on dressing change was lower in the calcium alginate group (p=0.047) and the total number of dressing changes tended also to be lower (p=0.07). Adverse events, which occurred 4 times in the calcium alginate group and 6 times in the other, were judged independent of the treatments. CONCLUSIONS: As compared with vaseline gauze, calcium alginate appears to be more appropriate for topical treatment of diabetic foot lesions in terms of both healing and tolerance.

Thyroid hormone extraction by plasma exchange: a study of extraction rate.

How to obtain an optimal efficiency of plasma exchanges in the treatment of severe hyperthyroidism has not been defined. In order to evaluate how long the exchanges must be continued to be fully effective in extracting thyroid hormones, we evaluated the extraction rate by repeated plasma sampling in two hyperthyroid patients and three euthyroid subjects who underwent a total of seven exchanges. Plasma concentrations of thyroid hormones were also determined just before, just after, and 24 hours following the exchange. The hormonal removal rate did not fall dramatically during the exchange, so that its efficiency--in terms of hormone extraction--depends closely on its duration. The determination of plasma thyroid hormone concentrations after the exchange does not appear to be useful in evaluating the thyroid hormone loss since these concentrations may not change in spite of the hormonal extraction.

[Variations in the amplitude of the Q wave at V5 during computerized exercise test. Value in the diagnosis of coronary insufficiency]. / Etude des variations d'amplitude de l'onde Q en V5 au cours de l'épreuve d'effort informatisée. Valeur dans le diagnostic de l'insuffisance coronaire.

The aim of this study was to evaluate the diagnostic value of changes in Q wave amplitude in the V5 chest lead in coronary artery disease, especially for the detection of significant (greater than or equal to 75% narrowing) left interior descending disease. The stress tests of 227 patients were reviewed and confronted with the results of coronary angiography in 93 patients with angiographically normal arteries, and 134 patients with left anterior descending disease of the latter, 37 had single vessel disease, 38 had double vessel disease and 59, triple vessel disease. The average values of the Q wave amplitude in V5 at the peak of effort were 0.97 +/- 1.04 mm in the control group; 0.53 +/- 0.65 mm (p less than 0.01) in the group with single vessel disease; 0.46 +/- 0.66 mm (p less than 0.01) in the group with double vessel disease and 0.64 +/- 0.9 mm (p = 0.04) in the group with triple vessel disease. The mean variations of the amplitude of the Q wave in lead V5 on effort in the same group of patients were: +0.55 +/- 0.73 mm (p less than 0.001); + 0.11 +/- 0.66 mm (NS); + 0.02 +/- 0.5 mm (NS) and + 0.05 +/- 0.53 mm (NS), respectively. The Q wave in lead V5 was generally deeper on effort in the control group and the average variation in its amplitude was statistically significant only in this group. In the coronary patients, the Q wave in lead V5 was generally smaller and its amplitude did not change significantly on effort.(ABSTRACT TRUNCATED AT 250 WORDS)