Concurrent training associated with moderate walnut consumption improved isokinetic strength, subjective sleep quality, cognitive performance and postural balance in elderly active men: a randomized controlled trial

AIMS

To investigate the effects of concurrent training (resistance and endurance) associated with moderate walnut consumption on isokinetic strength, subjective sleep quality, cognitive performance and postural balance in physically active elderly men.

METHODS

Twenty healthy elderly men were divided into two matched groups, in a randomized controlled experiment. They have participated in three training sessions per week: concurrent (strength and endurance) training + ad libitum diet with walnuts (15 g/day for 6 weeks, CTW: n = 10) and concurrent training + ad libitum diet (CT: n = 10). Isokinetic strength, Spiegel questionnaire, Montreal cognitive assessment and postural balance parameters were assessed 48 h pre- and post-intervention.

RESULTS

Absolute peak torque of knee extensors and knee flexors significantly increased compared to pre-training in CTW (15.2% ± 6.7; 13.2% ± 2.3, p < 0.05, respectively) and CT (10.6% ± 6.8; 7.4% ± 2.9, p < 0.05, respectively). Subjective sleep quality increased compared to pre-training for CTW and CT (24% ± 14.4; 10.5% ± 9.4, p < 0.05, respectively) with a significantly greater increase in CTW (p < 0.05). Cognitive performance measured by Montreal cognitive assessment (MoCA) increased only in CTW compared to baseline (7.7% ± 2.5, p < 0.05). Postural balance parameters with dual task decreased only in CTW compared to baseline.

CONCLUSIONS

The present study clearly revealed that concurrent training alone or associated with daily walnut (15 g) consumption for 6 weeks significantly increased knee isokinetic strength, support leg standing parameters and sleep quality. Meanwhile, cognitive performance evaluated by MoCA test and postural balance with dual task were improved for CTW group only.

Melatonin supplementation alleviates cellular damage and physical performance decline induced by an intensive training period in professional soccer players

Melatonin has been proved to have positive effects on cellular damage and metabolic regulation. The aim of the study was to determine the effect of melatonin supplementation during an intensive training period on physical performance decline, oxidative stress and cellular damage state. The investigation was conducted on 20 soccer players who participated in an exhaustive six-day training schedule associated with daily 5 mg oral melatonin or placebo ingestion. Resting blood samples and physical performance were measured before and after the training period. The mixed 2-way ANOVA (group x training camp) showed that compared to placebo, melatonin intake prevented an increase in advanced oxidation protein products (p>0.05) and increased the antioxidant enzyme activity (i.e., superoxide dismutase; p<0.001). In addition, melatonin prevented an increase of biomarkers of renal function (e.g., creatinine; p>0.05) and biomarkers of muscle (e.g., creatine kinase; p>0.05) and liver (e.g., gamma-glutamyltransferase; p>0.05) damage. Furthermore, melatonin alleviated the deterioration in physical performance (countermovement jump, five-jump test and 20-m sprint; p>0.05). In conclusion, the obtained data showed increased oxidative stress and renal, muscle and liver damage in professional soccer players during an exhaustive training schedule. Melatonin intake during the training period exerts beneficial effects on physical performance and protects tissues against the deleterious effects of reactive oxygen species and cellular damage.

Involvement of nitric oxide in corticosterone release and glucose metabolism in food deprived rats

This study was performed to investigate the involvement of nitric oxide (NO) in corticosterone, endpoint product of hypothalamo-pituitary-adrenal (HPA) axis activation, and metabolic responses to 3 days of food deprivation. To investigate this aim, we used a nonspecific inhibitor of nitric oxide synthases, N-nitro- L-arginine methyl ester (L-NAME). In food deprived group we have noted a significant increase in plasma corticosterone concentration accompanied by a significant depletion in hepatic glycogen content with concomitant increase in glycogen phosphorylase (GP) activity by 63.72%, key enzyme of glycogenolysis and decrease in hexokinase (HK) activity by 25.16%, leading to significant decrease in glucose concentration. However, L-NAME administration in food deprived rats decreased slightly corticosterone level and GP activity (16.39%) and increased HK activity (11.26%) as compared to food deprived group. Considering these results, we can deduce that in food deprivation nitric oxide is involved in the regulation of corticosterone release and in glucose metabolic responses via glycogenolysis activation by the stimulation of GP activity and the inhibition of HK activity. However, more studies are necessary to further clarify the mechanisms by which NO induces these responses.

[Molecular analysis of crossing-over in the CMH in two Tunisian families with aplastic bone marrow]

In order to select compatible human leucocytes antigens (HLA) donors for bone marrow graft, all the members of 76 families were typed by serology for HLA class I (A and B locus) and class II (DR, DQ locus) by polymerase chain-reaction-sequence-specific primes (PCR-SSP). The HLA typing interpretation revealed the existence of crossing-over in major histocompatibility (CMH) regions for two families, AB and AT, with aplastic bone marrow. The study of crossing-over site has needed the genotyping of seven short tandem repeat (STR) markers located on the short arm of chromosome 6 (D6S291, D6S273, TNFa, C1.2.C, C3.2.11, D6S265, D6S276), using ABI Prism 310 sequencer. HLA and STR Haplotypic analysis enabled us to confirm the crossing-over between locus B and DR in AB family and between locus A and B in AT family. Based in this study, we recommend to be careful in the interpretation of the results of HLA typing between donors and recipients of bone marrow. Complementary investigations should be accomplished for studying genetic abnormalities, which would be involved in this pathology.

Protective effect of resveratrol on ethanol-induced lipid peroxidation in rats

AIM

Chronic ethanol treatment induces an increase in oxidative stress. As polyphenolic compounds are potent antioxidants, we aimed to examine whether dietary supplementation of resveratrol may attenuate lipid peroxidation, the major end-point of oxidative damage resulting from chronic ethanol administration.

METHOD

Three groups of male Wistar rats were used. The first group served as control and received a daily intraperitoneal injection of 0.9% saline. The second group of rats was daily injected with 35% ethanol at 3 g/kg body weight. The third group was given the same dose of ethanol and supplemented with resveratrol (5 g/kg) in the standard diet. Malondialdehyde (MDA), an indicator of oxidative stress, was measured in the liver, heart, brain, and testis.

RESULTS

At the end of a 6 weeks treatment period, MDA levels were significantly increased by 51.5, 53.7, 72.7, and 40.5% in the liver, heart, brain, and testis, respectively. However, when ethanol treated rats were given resveratrol the increase in MDA levels was significantly reduced in all organs to nearly those of control rats.

CONCLUSION

Resveratrol is able to inhibit the ethanol-induced lipid peroxidation and have protective effect against oxidative injury.

Vasopressin and nitric oxide synthesis after three days of water or food deprivation

Nitric oxide has been suggested to be involved in the regulation of fluid and nutrient homeostasis. In the present investigation, vasopressin and nitric oxide metabolite (nitrite and nitrate) levels were determined in plasma of male Wistar rats submitted to water or food deprivation for three days. Hematocrit and plasma sodium showed marked increase in dehydrated and starved rats. Potassium levels and plasma volume decreased in both treated groups. Plasma osmolality and vasopressin levels were significantly elevated in water deprived (362.8 +/- 7.1 mOsm/kg H2O, 17.3 +/- 2.7 pg/ml, respectively, p < 0.001) rats, but not in food deprived (339.9 +/- 5.0, 1.34 +/- 0.28) rats, compared to the controls (326.1 +/- 4.1, 1.47 +/- 0.32). The alterations observed in plasma vasopressin levels were related to plasma osmolality rather than plasma volume. Plasma levels of nitrite and nitrate were markedly increased in both water and food deprived rats (respectively, 2.19 +/- 0.29 mg/l and 2.22 +/- 0.17 mg/l versus 1.33 +/- 0.19 mg/l, both p < 0.01). There was a significant negative correlation between plasma nitrite and nitrate concentration and plasma volume. These results suggest that both dehydration and starvation increase plasma nitric oxide, probably by activation of nitric oxide synthases. The release of nitric oxide may participate in the regulation of the alteration in blood flow, fluid and nutrient metabolism caused by water deprivation or starvation.

Evolution of acquired resistance to third-generation cephalosporins in Enterobacteriaceae in a Tunisian hospital 1993-2001

Between January 1993 and December 2001, the overall frequency of resistance to third-generation cephalosporins in isolates of Enterobacteriaceae from Charles Nicolle Hospital, Tunis, rose from 2.4% to 7.4%. Klebsiella pneumoniae was the most prevalent species (56%), followed by Escherichia coli (15%) and Proteus mirabilis (9%). A rate of 49% was observed among isolates from paediatric patients in 1999, caused mostly by outbreaks in the neonatal intensive care unit of K. pneumoniae and P. mirabilis isolates that produced extended-spectrum beta-lactamases.

Two-year surveillance of antibiotic resistance in Streptococcus pneumoniae in four African cities

Worldwide spread of antibiotic resistance in Streptococcus pneumoniae is a major problem. However, data from West and North African countries are scarce. To study the level of resistance and compare the situations in different cities, a prospective study was conducted in Abidjan (Ivory Coast), Casablanca (Morocco), Dakar (Senegal), and Tunis (Tunisia), from 1996 to 1997. The resistances to eight antibiotics of 375 isolates were studied by E test, and the results were interpreted using the breakpoints recommended by the National Committee for Clinical Laboratory Standards. Overall, 30.4% of the isolates were nonsusceptible to penicillin G (25.6% were intermediate and 4.8% were resistant). Amoxicillin (96.3% were susceptible) and parenteral third-generation cephalosporins (92.7%) were highly active. Resistance to chloramphenicol was detected in 8.6% of the isolates. High levels of resistance were noted for erythromycin (28%), tetracycline (38.3%), and cotrimoxazole (36.4%). Resistance to rifampin was rare (2.1%). There were significant differences in resistance rates between individual countries. Multiple resistance was more frequent in penicillin-nonsusceptible isolates than in penicillin-susceptible isolates. Recommendations for treatment could be generated from these results in each participating country.

[Infectious endocarditis caused by a glycopeptide-resistant enterococus]

Enterococci are an important cause of infective endocarditis. Their resistance to most of the antibiotics involve real therapeutic problems. We report the first clinical isolate of glycopeptide resistant enterococcus from blood culture of patient with a prosthetic valve endocarditis. The strain is an E. faecium with a high level of resistance to vancomycin and teicoplanin (MIC > 256 mg/l), a low level of resistance to gentamycin (MIC = 6 mg/l) and susceptible to ampicillin (MIC = 1.5 mg/l). Therapeutic failure was observed leading to a surgical treatment. Therapy of such infection caused by multiresistant Enterococcus must be based on the study of bactericidal activity of antibiotic associations. In order to control the spread of this emerging resistance, the implementation of control measures is necessary.

Vasopressin and A1 noradrenaline turnover during food or water deprivation in the rat

In the present study, we have examined in Wistar rats the effects of food or water deprivation of 3 days on the hypophyso-adrenal axis, vasopressinergic system and activity of A1 noradrenergic brain stem cell group, which is involved in the control of the hypothalamic neuro-endocrine activity. Levels of adrenocorticotropic hormone (ACTH) and vasopressin (AVP) were determined by radio-immunoassay, and corticosterone level was determined by fluorimetric method. Plasma levels of ACTH and corticosterone were greatly increased in both groups of rats. In water-deprived rats, plasma AVP (13.83 +/- 1.63 vs. 3.03 +/- 0.23 pg/ml) and osmolality levels were significantly elevated with a marked decrease of AVP hypophysis content (272 +/- 65 vs. 1098 +/- 75 ng/mg protein), but not in food-deprived rats in which osmolality did not change and AVP remained stocked (2082 +/- 216 ng/mg protein) in the hypophysis without release in the plasma (1.11 +/- 0.23 pg/ml). These observations indicated that both food-deprivation and water-deprivation stimulated the pituitary adrenal axis thereby suggesting a stress state. AVP production is stimulated both by fluid and food restriction but is secreted with differential effects: during food restriction AVP secretion is limited to supporting the hypothalamic pituitary-adrenal system.

[The effect of age and dehydration on the activity of the vasopressinergic system in rats]

The aim of our work was to study the different blood parameters as well as the activity of the vasopressinergic axis in young and mature male rats under normal conditions and following a 3-day dehydration cycle by water deprivation. Under normal conditions, our study demonstrates higher levels of vasopressin in mature rats as compared to young rats. This could be due in part to the higher blood osmolality in the mature rats. After dehydration, hypovolemia, plasmatic hyperosmolality, hypernatremia and hyperproteinemia cause a stimulation in vasopressin synthesis and release, as seen in results obtained from the hypothalamus, hypophysis and plasma in both young and mature rats. However, the response of the vasopressinergic axis to dehydration is greater in young rats, suggesting a more pronounced sensitivity to osmotic factors.

Urolithiasis in Tunisian children: a study of 120 cases based on stone composition

The composition of urinary stones in children depends on socioeconomic conditions and hygiene, geographical area, and dietary habits. We analyzed urinary stones from 120 consecutive Tunisian children (81 males, 39 females) aged 5 months to 15 years. The stone was located in the upper urinary tract in 91 cases (76%). Stone analysis included both a morphological examination and an infrared analysis of the nucleus and the inner and peripheral layers. The main components of bladder calculi were whewellite (69%) and struvite (22%), whereas the main component of upper urinary tract calculi was whewellite (67%). The nucleus of bladder stones was composed of ammonium urate (45%), struvite (28%), cystine (10%), and carbapatite (7%). The nucleus of kidney and ureteral calculi was mainly composed of ammonium urate (38%), whewellite (24%), carbapatite (13%), or struvite (11%). Based on stone composition, urinary tract infection was involved in the nucleation or growth of a third of calculi. Endemic urolithiasis involving simultaneous nutritional, metabolic, and infectious factors, and defined by its nucleus composed of ammonium urate without struvite, represented 40% of cases. Exclusive metabolic factors - including genetic diseases such as primary hyperoxaluria, cystinuria, and hypercalciuria - were responsible for less than 25% of cases.

[Colonic tuberculosis: an exceptional cause of a massive surgical hemorrhage apropos of a case and review of the literature]

Colonic tuberculosis rarely causes massive bleeding, as a matter of fact less than twenty cases have been reported in medical literature. Resorting to surgery in this context is even more exceptional. We have not found any case operated on in the literature we have consulted. Endoscopy together with histological study of biopsies is the best exam for the diagnosis of this disease. We report the case of a 37 year old male, coronarian, carrying a caecal lesion evocative of tuberculosis at the endoscopic exam, who had an emergency right hemicolectomy for massive bleeding caused by caecal tuberculosis. The surgical indication was dictated by the abundance and the persistence of the bleeding. The post-operative course was uneventful.

[Effect of fasting on glycemia and proteinemia in young and adult rats]

The aim of Our work has consisted of studying the effects of a severe three-day fast on the evolution of the body weight, on glycemia and on proteinemia among the young and mature male rats. The decrease in body weight which is more marked among young rats after starvation shows that the loss of body mass due to fasting decreases with the age of the rats. The physiological perturbations of nutritive constants that have been recorded during this period of fast show that the mature rat first attacks its non-protein stocks or glucides, which leads to a decrease in its glycemia and in its lipids; whereas the young rat uses its proteins after only three days of starvation because of its small stock of lipids.

Tissue norepinephrine turnover and cardiovascular responses during intermittent dehydration in the rat

We investigated the central and peripheral sympathetic responses to intermittent dehydration in rats. The norepinephrine (NE) turnover, a biochemical index correlated with noradrenergic neuronal activity, was measured. The modification of blood pressure was also determined by telemetry during the different cycles of dehydration. Dehydration caused a decrease of NE turnover in A2, A5 and A6 nuclei and in peripheral organs. The vasopressinergic level of dehydrated rats decreased in hypophysis and hypothalamus, and increased in plasma. A repeated gradual increase of arterial blood pressure during the first three days of dehydration, followed by a sudden drop when the rats were rehydrated on the fourth day was observed. In conclusion, our study revealed an increase in blood pressure and in central sympathetic activity during dehydration.

Effects of acute and chronic starvation on central and peripheral noradrenaline turnover, blood pressure and heart rate in the rat

When faced with stress, an organism calls upon several mechanisms to maintain biological homeostasis. The cardiovascular system is the first to respond usually with an increase in arterial pressure and tachycardia. Therefore we investigated the central and peripheral sympathetic responses to acute and chronic starvation in Wistar rats. The noradrenaline (NA) turnover rate was determined in different catecholaminergic nuclei (A1, A2, A5, A6) as well as the arterial blood pressure and heart rate modifications. During acute starvation (3 days of starvation), the NA turnover was increased in the A1 and rostral A2 nuclei as well as in ventricles and kidneys and decreased in the A6 nucleus. During chronic starvation (4 consecutive cycles of 3 days of starvation plus 1 day of feeding), the NA turnover was increased in the A5 and caudal A2 nuclei as well as in ventricles and atria and decreased in the A1 nucleus and kidneys. The arterial blood pressure revealed a gradual decrease during the first 3 days of fasting but the heart rate was not modified. We conclude that starvation should be considered as an unusual state of stress because of the absence of locus coeruleus response (A6 nucleus) despite its well-defined role in stress reactions. One of the manifestations of these central and peripheral noradrenergic changes is the change in blood pressure during the starvation-feeding cycles.

Effects of acute and chronic starvation on central and peripheral noradrenaline turnover, blood pressure and heart rate in the rat

When faced with stress, an organism calls upon several mechanisms to maintain biological homeostasis. The cardiovascular system is the first to respond usually with an increase in arterial pressure and tachycardia. Therefore we investigated the central and peripheral sympathetic responses to acute and chronic starvation in Wistar rats. The noradrenaline (NA) turnover rate was determined in different catecholaminergic nuclei (A1, A2, A5, A6) as well as the arterial blood pressure and heart rate modifications. During acute starvation (3 days of starvation), the NA turnover was increased in the A1 and rostral A2 nuclei as well as in ventricles and kidneys and decreased in the A6 nucleus. During chronic starvation (4 consecutive cycles of 3 days of starvation plus 1 day of feeding), the NA turnover was increased in the A5 and caudal A2 nuclei as well as in ventricles and atria and decreased in the A1 nucleus and kidneys. The arterial blood pressure revealed a gradual decrease during the first 3 days of fasting but the heart rate was not modified. We conclude that starvation should be considered as an unusual state of stress because of the absence of locus coeruleus response (A6 nucleus) despite its well-defined role in stress reactions. One of the manifestations of these central and peripheral noradrenergic changes is the change in blood pressure during the starvation-feeding cycles.

[Adrenal cortex activity in the malnourished newborn rat]

Newborn rats (4 day-old) were subjected to chronic malnutrition through their mothers submitted to an intermittent fasting (one day out of two) during 41 days. These offspring were compared with others undergoing a treatment of a 21 days malnutrition followed by 20 days ad libitum realimentation. Rats whose mothers were nourished ad libitum with a standard diet served as controls. The body growth was hindered by the malnutrition but restored when fasting was followed by realimentation. The weight of the encephalon, the heart and the ovary was unchanged. In contrast, testicle atrophy was observed without correction by realimentation. A corticoadrenal activation characterized by an increase in blood and adrenal corticosterone levels and by an adrenal gland hypertrophy was observed in undernourished animals. A lower response of the adrenal cortex to ether stress (added stress) was also observed. All these perturbations were suppressed when fasting was followed by refeeding.

[Urinary calculi in children: contribution of anamnesis, biological exploration and physical analysis of calculi to the etiological diagnosis]

BACKGROUND

It is always of importance to define the cause of urinary calculi disease in children to prevent recurrence and possible impairing of renal function. Nevertheless, etiology is not always easy to prove and must be deduced from both clinical and biological arguments.

PATIENTS AND METHODS

The aim of this prospective study including 39 Tunisian children with urinary stones was to identify etiology and stone risk factors and detail the part of clinical and biological data and results of physical analysis of stones in determining the cause of the stone.

RESULTS

In 31 cases among 39, clinical and biological data were not sufficient to identify clearly the stone etiology. When considering the structure and stone composition, the cause of the stone could be determined in 97.4% of the cases. An inherited disease was found responsible for the stone in 11 children, urinary tract infection in 13 cases, idiopathic hypercalciuria in nine cases and a nutritional deficiency disease in seven cases. In one case, polycystic kidney disease with metabolic risk factors could explain the stone process. No precise etiology was found in one case. Among infection stones, struvite stones could be related to urea-splitting bacteria while other calculi, containing whitlockite and protein matrix could be related to other micro-organisms. Earlier severe chronic diarrhoea episodes were noted in six among seven children presenting stones with a nucleus mainly composed of ammonium urate.

CONCLUSION

Clinical data, biological data from both urine and blood of the patients and also the structure and composition of the stones are needed to identify the cause of urinary calculi. Such a procedure could provide the stone etiology in most cases.

[Sequential and ultrastructural study of lactotroph response to stress in rats as a function of age]

In adult rats, ether inhalation stress stimulated basal serum prolactin (PRL) significantly, within a maximum delay of one minute. The same pattern was seen with immature animals of 15-20 and 30 days of age. In contrast, in 2 or 6 days old neonates, serum PRL concentrations remained unaffected by stress. This lack of responsiveness suggests the existence of a transient impairment of lactotroph hormones to stressful stimuli during postnatal life. This hypothesis has been controlled by ultrastructural exploration of lactotrophs. The distribution of organites and secretion grains in lactotrophs was similar in unstressed neonates and adult rats, but after ether stress, the distribution of secretion grains became different with age. Adult lactotrophs showed a peripheral secretion grains aspects indicating cells discharge. In the very young rats, the grains were distributed in the totality of the cytoplasm. These results confirm the existence, in the lactotrophs, of a refractory period to stress in the neonate rats.

[Effects of simulated weightlessness on the hypophyseal-cortical-adrenal axis in the pregnant rat]

The eventual part of stress in the hormonal responses to simulated weightlessness was studied during gestation in the rat. We have compared these responses with the effects of two other situations well-known to provoke stress: ultrasounds and denutrition. An increase of blood and adrenal corticosterone levels was found in mothers after denutrition, neither after ultrasounds nor after simulated weightlessness. In foetuses, a decrease of weight was noted after denutrition and simulated weightlessness. Foetal suprarenal corticosterone remained normal when mothers were submitted to simulated weightlessness. In this group, a decrease in foetal weight was found that could be explained by non suprarenal hormonal factors or by circulation disturbances.

[Primary hyperoxaluria: Tunisian experience apropos of 24 pediatric cases]

We report on 24 children (10 girls) presenting with primary hyperoxaluria. The mean age at diagnosis was 6.3 years (range: 3 months-14.8 years). The mean interval between initial symptom and diagnosis was 1.3 year. The average follow-up period was 22 months (range: 1-60 months). At the time of diagnosis the renal function was normal in 6 children, moderately altered in 1 and severely in 17. During the follow-up the renal function remained stable in 6 patients, improved in 2, deteriorated in 4. The 12 patients with end-stage renal disease at diagnosis remained unchanged. Urolithiasis were present in all patients older than 2 years, and in 1 among the 5 infants. Medullary nephrocalcinosis was observed in 3 patients in whom the renal function was preserved. Diffuse nephrocalcinosis was present in all patients with end-stage renal failure. Improvement of renal function was secondary to stone removal in 2 patients. Extracorporeal shock wave lithotripsy performed in 7 patients was efficient only in 3. In 10 patients oxalate bone disease was correlated with both renal function and dialysis duration, whereas retinal involvement noted in 6 patients was not.

[Infantile forms of primary hyperoxaluria type I: apropos of 4 cases]

BACKGROUND

Approximately 10% of the cases with primary hyperoxaluria type I present before age 1 and are usually classified as neonatal primary oxaluria.

CASE REPORTS

Four unrelated infants, aged 3 to 9 months, were admitted for severe renal failure due to primary hyperoxaluria type I. Other affected members were known in two of these four families but the disease was not present at the same age in each family. Echogenicity of kidneys was increased in all the patients and calcium oxalate crystals were seen in the collecting system and within the renal parenchyma. Urolithiasis was not present. Treatment of renal failure, ie, peritoneal dialysis, was uneffective in one patient and was interrupted in two others because organ transplantation was impossible.

CONCLUSIONS

The infantile forms of primary hyperoxaluria type I may be rapidly complicated by severe renal failure in the absence of urolithiasis.

End-stage renal disease of the Tunisian child: epidemiology, etiologies, and outcome

From December 1989 to December 1993, 90 children under 15 years were admitted to our department for end-stage renal disease; 9 children were less than 5 years and 28 were aged between 5 and 10 years. The sex ratio (M/F) of the children was 2.1. The estimated incidence of pediatric end-stage renal disease in Tunisia is 7 new cases per year and per million child population under 15 years. The chief etiologies of end-stage renal disease are glomerulonephritis (19%), hereditary nephropathies (29%), and malformative uropathies (13%); 26% of the end-stage renal diseases are of unknown etiologies. Our findings, compared with the European data, show a particularly high frequency of primary hyperoxaluria (13.5%) and an unusual proportion of male subjects.

Cortico-adrenal function under simulated weightlessness during gestation in the rat--effects on fetal development

To examine the effects of simulated weightlessness on cortico-adrenal function and on fetal development, we suspended pregnant rats for 20 days. The levels of adrenal and plasma corticosterone were examined in mothers and in fetuses. The animal control group was kept single in standard cages. Growth of the suspended animals was repressed for the first 8 days of the experiment, but thereafter it increased greatly, as did the daily food intake. By the 18th day of the experiment, the body masses and food intake of the two groups were equal. No modification in circulating corticosterone was found. It appears that there is no stress in pregnant rats submitted to simulated weightlessness.

[Etiologic factors of urinary lithiasis in Tunisian children]

Fifty-five Tunisian children with urinary stones, between the ages of 8 months and 15 years, underwent morphological and infrared spectrophotometric analysis of their stones. This study provides an approach to the aetiological profile of urinary stones in Tunisian children. The nucleus of the stones was composed of acidic ammonium urate in 48% of cases with a morphology suggestive of phosphorus deficiency associated with a history of diarrhoea. In 24% of cases, the nucleus contained struvite indicating the presence of urinary tract infection by urease-positive bacteria. The main growth factors of urinary stones were hyperoxaluria and urinary tract infection. In 5 cases, the stones were due to a hereditary lithogenic metabolic disease : cystinuria in 1 case and primary hyperoxaluria in 4 cases.

Growth stimulation of human skin fibroblasts by elastin-derived peptides

Elastin-derived peptides (kappa-elastin: kappa E, mean molecular mass: 75 kDa), either coated onto plastic dishes or added to culture media (0.26 to 1.33 nM) stimulated the growth of human skin fibroblasts (HSF) strains obtained from different donors and tested at different cell passages (4 to 12). Coated 44.4 micrograms/cm2 insoluble elastin (iE) exhibited the same action; coated iE or kappa E significantly modifies the HSF morphology: after 5-6 days of culture, HSF are more elongated, and at preconfluence state, formation of HSF clusters surrounding iE were observed. Increased 3H thymidine incorporation and proliferative effect of HSF by kappa E (1.3 to 2.2 fold as compared to control cells) was observed after a lag phase period which raised with initial HSF density. Optimal proliferative effect was obtained at kappa E 8.5 10(-10) M, a value close to the dissociation constant (kD = 2.7 10(-10) M) of kappa E to HSF. Valine-glycine-valine-alanine-proline-glycine (VGVAPG), but not valine-glycine-valine (VGV) or Valine-glycine-valine-valine-glycine-alanine (VGVVGA) also significantly stimulated, optimally at 7.0 10(-10) M, HSF proliferation. It was concluded that the stimulatory influence of elastin derived peptides on HSF proliferation was mediated through a binding to plasmalemmal receptor of HSF.

[Value of extracorporeal shockwave lithotripsy in primary hyperoxaluria type I]

BACKGROUND

Application of extracoporal shock wave lithotripsy (ESWL) has revolutionized the management of many types of urolithiasis, including that observed in primary hyperoxaluria where surgical attempts to remove calculi sometimes result in worsening of renal function.

CASE REPORTS

Three unrelated patients aged 8, 10 and 11 years, respectively, with type I primary hyperoxaluria, suffered from recurrent bouts of abdominal pain (two patients) or anemia (one patient). Two patients had chronic renal failure. Plain abdominal films and ultrasonography showed several large bilateral stones. ESWL was applied to the three patients permitting complete removal of stones following three sessions in one patient and partial removal following four sessions in the second patient who developed infection after the first session with transitory increase in creatinemia. Several sessions of ESWL failed to fragment stones in the third patient.

CONCLUSION

ESWL may represent a safe procedure for attempting stone removal in patients with primary hyperoxaluria.

[Can a serotonin uptake agonist be an authentic antidepressant? Results of a multicenter, multinational therapeutic trial]

The classical biochemical hypothesis of depression posits a functional deficit in central neurotransmitter systems particularly serotonin (5-HT) and noradrenaline. The major role suggested for 5-HT in this theory led to the development of a large number of compounds which selectively inhibit 5-HT uptake. Numerous clinical trials have demonstrated the antidepressant efficacy of such types of serotoninergic agents, supporting 5-HT deficit as the main origin of depression. Therefore, everything seemed clear: depression was caused by 5-HT deficit. Tianeptine is clearly active in classical animal models predictive of antidepressant activity, and is also active in behavioral screening tests: it antagonizes isolation induced aggression in mice and behavioral despair in rats. Biochemical studies have revealed that in contrast to classical tricyclic antidepressant, tianeptine stimulates 5-HT uptake in vivo in the rat brain. This somewhat surprising property was observed in the cortex and the hippocampus following both acute and chronic administrations. This increase in 5-HT uptake has also been confirmed in rat platelets after acute and chronic administrations. Moreover, in humans, a study in depressed patients demonstrated that tianeptine significantly increased platelet 5-HT uptake after a single administration as well as after 10 and 28 days of treatment. The antidepressant activity of tianeptine has been evaluated in controlled studies versus reference antidepressants. Another study aiming to compare the antidepressant efficacy of tianeptine versus placebo and versus imiporamine is presented. 186 depressed patients were included in this trial. They presented with either Major Depression, single episode (24.6%) or Major Depression recurrent (66.8%) or Bipolar Disorder (depressed) (8.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of tianeptine on the hypothalamic somatotropic axis in the conscious sheep

The action of serotonin on growth hormone (GH) secretion is controversial because of interspecies differences and lack of specificity of serotoninergic drugs. Serotonin (5-HT) appears to inhibit GH release in the sheep and in man. We have investigated the site of action of tianeptine, a 5-HT uptake enhancer, in sheep since it is possible to collect hypophysial portal blood for the simultaneous determination of growth hormone-releasing hormone (GHRH) and somatostatin in this species under conscious, unstressed conditions. Tianeptine injection (10 mg/kg i.v.) resulted in a significant, immediate and short-lasting (30 min) increase in peripheral GH (+750%; P < 0.01) and hypophysial portal GHRH (+180%; P < 0.01). No change in the secretion of somatostatin was recorded during the same time. These data suggest that serotoninergic inputs are inhibitory to GH secretion. Tianeptine acts centrally to stimulate GH secretion in the sheep and its effect is mediated through changes in GHRH but not somatostatin release into hypophysial portal blood.

Novel bioactive compounds from actinomycetes

Actinomycetes form an enormous reservoir of secondary metabolites and enzymes. The potential for exploiting rare actinomycetes is highlighted by the discovery of novel compounds from strains of Spirillospora and Nocardioides. Novel compounds of well known classes of antibiotics, such as polyenes, continue to be discovered. For compounds containing a chromophore, the analysis by high-performance liquid chromatography coupled with a diode-array detector enables the elimination of producers of known compounds and facilitates the discovery of novel compounds or derivatives. The complexity of the regulatory mechanisms is illustrated by glutamine synthetase. The characterization of thermostable amylolytic, lignolytic, peroxidase and neuramidase activities, and the isolation of novel cellulolytic actinomycetes clearly demonstrate the potential of Actinomycetes as producers of enzymes.

[Study of antibiotic sensitivity of Streptococcus pyogenes isolated in the hospital milieu (Charles Nicolle hospital of Tunis)]

The purpose of the present work was to investigate the susceptibility of S. pyogenes to antimicrobial agents. The strains have been taken from the bacteriological Service of Charles Nicolle's hospital at Tunis, and that during the period from January 1988- to December 1990. The antibiogram results as well as the minimal inhibitrice concentration determined by the agar diffusion technique, reveal that S. pyogenes continues to be very susceptible to the beta-lactamins (M.I.C. of penicillin G is "0.15 for 50% of strains tested. Resistance are noted for chloramphenicol; tetracycline and novobiocine (13%, 93%, 80%) not considered as good antibiotics anti-streptococcies. The macrolids are effective against S. pyogenes (100% of susceptibility) that's they are considered as the best alternating antimicrobiologents to the beta-lactamins (M.I.C. of erythromycin is 0.015.