Microscopic polyangiitis following recurrent Staphylococcus aureus bacteremia and infectious endocarditis.

Secondary vasculitis resulting from unusual pathologic expressions of infections has been described and has important clinical significance. Infectious agents have also been implicated in the pathogenesis of different primary systemic necrotizing vasculitides. Infectious endocarditis is of particular importance in the differential diagnosis of a patient presenting with ANCA associated vasculitis. We report a well-documented case of a patient with recurrent Staphylococcus aureus bacteremia who developed bacterial endocarditis and also fulfilled the Chapel Hill Conference definitions for microscopic polyangiitis. To the best of our knowledge, it is the second case of bacterial endocarditis associated with both pANCA and anti-MPO specificity that fulfilled definitions for systemic necrotizing vasculitis. We emphasize the potential pathogenic role of infection as the trigger factor for the development of systemic vasculitis.

[Two unexpected cases of hepatobiliary fascioliasis in Dakar (Senegal)]. / Deux observations inattendues de distomatose hépato-biliaire à Dakar (Sénégal).

The authors report two hepatobiliary distomatosis cases on patients living in Senegal and Cape Verde islands. No similar case has been reported in Senegal so far. The first case was a 41 years old woman who presented enlarged, painful liver with hypereosinophilia. There was no fever. Ultrasound and CT Scan demonstrated the presence of three poorly limited and heterogeneous masses, located on the liver right lobe. The percutaneous biopsy was not suggestive. Because of the fear ofhepatocellular carcinoma, a hepatectomy was performed and eosinophilic abcesses were found in the piece of resected liver with Fasciola eggs. The second case was a 32 years old man who presented a febrile enlarged liver with hypereosinophilia. Ultrasound revealed an heterogenous process of the liver fourth segment Serology study using Fasciola hepatica antigen was positive. The treatment with Praziquantel was successful. The clinical and epidemiological inquiry in both cases has found stays in Cape Verde islands before the disease. This was consistent with a contamination in that region. In both cases either F hepatica or F gigantica could be responsible since the serological tests are not able to differentiate these two species. Parasitic hepatopathies should be recognised particularly when a painful liver process is associated to hypereosinophilia. The serological tests will help to establish the diagnosis

Increased glucose synthesis in renal tubule fragments from hyperthyroid rats.

Rates of glucose synthesis from several substrates were examined in renal tubule fragments from hyperthyroid rats. A hyperthyroid state was induced by daily intraperitoneal injections of thyroxine (T4) (100 microg/100 g body weight) for 14 days. At the end of the experimental period, plasma triiodothyronine and T4 levels were six and eight times higher, respectively, than initial values. Hyperthyroid rats gained less weight and had lower blood glucose despite an increased food intake. In both control and hyperthyroid rats, rates of glucose production by renal tubule fragments were higher with glutamine and glycerol than with lactate, alanine, or glutamate. T4 treatment induced a significant increase in the de novo glucose synthesis from all substrates, except glutamine. The highest percent increase was obtained with alanine (64%), compared with 31-40% for glutamate, lactate, and glycerol. The T4 treatment induced increase in glucose synthesis by renal tubule fragments suggests that renal gluconeogenesis contributes to enhance glucose production in hyperthyroidism.

Gluconeogenesis and glucose replacement rate during long-term fasting of Japanese quails.

Gluconeogenic activity and kinetic parameters of glucose metabolism were estimated during the different phases of prolonged food deprivation in quails. Gluconeogenic activity, estimated from the rate of increase of incorporation of H14CO-3 into circulating glucose, was significantly higher in fasted quails than in fed birds, whatever the period of food deprivation. However, gluconeogenic activity during phase II, although higher than in the fed state, was significantly lower than in quails fasted for 2 days (phase I) or in those on the final (phase III) period of starvation. Gluconeogenic activity did not differ significantly in birds from phases I and III. Rates of glucose replacement, estimated with [6-3H]-glucose, were very high (20.5 mg.kg-1.min-1) in fed quails and were markedly reduced (to about 42% of fed values) by fasting, no difference being observed between quails fasted for 2 and 5 days. Because of the poor condition of the birds, glucose replacement rates could not be measured during phase III. The present data are the first to provide direct evidence for the changes in gluconeogenesis which occur during prolonged food deprivation.

Metabolic adaptations induced by long-term fasting in quails.

After up to 21 days without food, adult male quails (Coturnix coturnix japonica) lost about 45% of the initial body weight (100-150 g). As in naturally fast-adapted and larger birds, three phases were identified during prolonged fasting in quails. Phase I lasted 2-3 days and was characterized by a rapid decrease in the rate of body weight loss and high fat mobilization. Phase II was longer and characterized by a slow and steady decline in the rates of body weight loss and of nitrogen excretion. The third (critical) period was marked by an abrupt increase in the rates of body weight loss and of nitrogen excretion. Despite their small size, the duration of phase II in quails was relatively long, a clear advantage for the study of the relationships between the several metabolic events that occur during this crucial adaptative period. Also, the beginning of phase III could be precisely determined. Changes in blood glucose, plasma FFA and triacylglycerols levels, as well as in liver and carcass lipid content were similar to those found in other species of birds. Therefore, quails seem to be a suitable model to investigate the biochemical mechanisms involved in the metabolic adjustments to prolonged food deprivation in non fasting-adapted birds.

Role of the adrenal glands in insulin-induced free fatty acid mobilization in the chicken.

The effects of the administration of insulin on plasma free fatty acid (FFA) levels of adrenalectomized and sham-operated (SO) chickens were compared in order to determine if the lipid-mobilizing action of the hormone is mediated by the adrenal glands. Plasma FFA levels of adrenalectomized and SO chickens were the same before hormone administration (0.69 +/- 0.03 vs 0.72 +/- 0.03 mu Eq/ml, N = 15 for each group). Injection of insulin (1 U/kg, iv) caused a significant increase of plasma FFA of SO chickens (103%) but did not modify FFA levels of adrenalectomized chickens. Blood sugar levels were higher in SO than adrenalectomized birds (163 +/- 4 vs 126 +/- 3 mg/100 ml, N = 9 for each group) before insulin administration but the magnitude of the reduction of blood sugar induced by insulin was similar for both groups. The marked lipolytic effect of glucagon (0.2 mg/kg, iv) on intact chickens was affected only to a small extent by adrenalectomy but, in contrast, the blood sugar response to glucagon was greatly reduced (27%) in adrenalectomized chickens. Significant increases (38%) in plasma FFA levels of intact chickens were obtained during the first few hours after a single intravenous injection of hydrocortisone (10 mg/kg, iv). The data show that the presence of the adrenal glands is essential for the increase in plasma FFA induced by insulin in chickens, and suggest that the lipid-mobilizing effect of the hormone in this species is due to an increased secretion of endogenous glucocorticoids following insulin-induced hypoglycemia.

Gluconeogenesis in guinea pig renal tubule fragments--effects of noradrenaline, 3':5' cyclic AMP and angiotensin II.

1. Tubule fragments were isolated by collagenase treatment of guinea pig kidney cortex. 2. 3':5'-Cyclic AMP increased gluconeogenesis from lactate, pyruvate, malate and fructose. 3. Noradrenaline decreased gluconeogenesis from lactate, pyruvate, 2-oxoglutarate and fructose. 4. Angiotensin II slightly, but significantly, increased gluconeogenesis from lactate. 5. Gluconeogenesis from glycerol as sole substrate was negligible. Gluconeogenesis from combinations of glycerol together with either lactate, pyruvate, 2-oxoglutarate or malate was appreciably greater than the sum of the glucose output observed when these substrates were added singly.

Stimulation of renal gluconeogenesis by exogenous adenine nucleotides.

1. Tubule fragments were isolated from renal cortex of fed rats. 2. Gluconeogenesis from lactate was significantly increased by low concentrations of exogenous ATP, ADP, AMP adenylyl (beta, gamma-methylene)diphosphonate and, to a lesser extent, by ITP and inosine. GTP was slightly inhibitory. Hypoxanthine was ineffective. Exogenous adenosine deaminase slightly decreased gluconeogenesis and was additive in effect to GTP. Adenosine deaminase did not abolish the stimulatory effects of ATP or cyclic AMP. 3. 40 microM ATP also stimulated gluconeogenesis from pyruvate, malate, succinate, 2-oxoglutarate and glutamine, but had no effect when glycerol or fructose were used as substrates. 4. With lactate as substrate the effect of 40 microM ATP was additive to the maximal stimulations of gluconeogenesis seen with 1 microM noradrenalin or 0.1 microM angiotensin II, but was not additive to the stimulatory effect of 0.1 mM cyclic AMP. 5.40 microM ATP had no effect upon either the tubule content of cyclic AMP or upon 45Ca efflux from prelabelled tubules. 6. Addition of ouabain or removal of extracellular K+ diminished the stimulatory effects of ATP and cyclic AMP. 7. Extracellular ATP was rapidly metabolized by tubule fragments, with resulting accumulation of adenosine. Further metabolism resulting in formation of inosine, hypoxanthine, xanthine and uric acid was also observed. Cyclic AMP was metabolized less rapidly, with no accumulation of adenosine. 8. The effects of purinergic agents on gluconeogenesis are discussed.

Effects of fasting and adrenalectomy on the kinetics of glucose metabolism in granivorous and carnivorous birds.

1. [1-(14)C]-Glucose was used to estimate the rate of glucose replacement and of hexose recycling via 3-carbon compounds in fed, fasted and fasted-adrenalectomized granivorous (chickens) and carnivorous (black vultures) birds. 2. Fed chickens had a larger body glucose mass and 3 to 4-fold higher rates of glucose replacement than fed black vultures. Glucose recycling represents a larger fraction of the overall glucose replacement rate in chickens (60%) than in black vultures (25%). 3. Following a 72-h fast, the body glucose mass of chickens decreased markedly, without appreciable changes in fractional turnover rates but glucose replacement rates were reduced to 48% of fed values. In contrast, these parameters were much less affected by fasting in carnivorous birds, the largest difference being the rate of replacement which was 70% of the fed values. 4. In both species, fasting after adrenalectomy induced a marked reduction of body glucose mass. However, while fractional turnover rates increased in black vultures, they actually decreased in chickens. Consequently, glucose replacement rates were markedly reduced in fasted-adrenalectomized chickens, but did not change or increase in black vultures. Adrenalectomized chickens showed decreased tolerance to intravenous glucose loads. 5. The results indicate that: a) the maintenance of constant blood sugar levels during prolonged fasting in carnivorous birds is due solely to their high gluconeogenic capacity and b) in carnivorous, but not granivorous birds, increased rates of peripheral glucose utilization plus diminished gluconeogenesis contribute to reduce blood sugar levels after adrenalectomy.

Fasting, adrenalectomy, and gluconeogenesis in the chicken and a carnivorous bird.

Previous studies showed that livers from carnivorous birds have a higher gluconeogenic capacity and higher levels of gluconeogenic enzymes than livers from granivorous birds. In this work we compare the effects of fasting and adrenalectomy on gluconeogenesis. Fasting in the chicken elicited increased rates of incorporation of 14C from alanine into blood glucose, increased gluconeogenesis in liver slices, and increased activities of four gluconeogenic enzymes: glucose-6-phosphatase, phosphoenolpyruvate carboxykinase, alanine aminotransferase, and aspartate aminotransferase. These responses in the chicken resemble those observed in fasted rodents. In marked contrast, fasting in black vultures induced decreased rates of incorporation of alanine label into circulating glucose, decreased gluconeogenesis in liver slices, and no change in any of the four enzymes studied. This unusual response to fasting in the carnivorous bird is probably related to the high-protein-low-carbohydrate content of the diet. Fasted adrenalectomized birds (granivorous and carnivorous) had reduced rates of in vivo glucose synthesis, decreased liver gluconeogenesis, and lower activity of glucose-6-phosphatase and aspartate aminotransferase, without change in phosphoenolpyruvate carboxykinase and alanine aminotransferase activities.