The rate of lactate removal after maximal exercise: the effect of intensity during active recovery.

AIM: The aim of the present investigation was to determine the greater rate of lactate removal after a maximal rowing test using different intensities during active recovery. METHODS: Thirty elite male rowers performed a simulated incremental exercise protocol on rowing ergometer to determine their maximal oxygen uptake and they divided into three equal sized group according to the type of the recovery that followed the assessment. The first group (N.=10) subjected to 20 min of passive recovery, while the second (N.=10) and the third (N.=10) groups performed 20 min of active recovery using the 25% and the 50% of each individual's maximal power output, respectively. During the recovery period, every two min were performed measurements for the assessment of blood lactate, oxygen consumption and heart rate (HR). RESULTS: It was found that after 10 min of active recovery at 50% and 25% of maximal power output lactate concentration reduced by 43% and 15%, respectively, while during passive recovery lactate concentration found to be slightly elevated by 1%. It was also found that during recovery period, HR, oxygen consumption and pulmonary ventilation was significant elevated at higher exercise intensity compared to lower exercise intensity and passive recovery. CONCLUSION: It is concluded that in elite male rowers the active recovery provided higher rate of lactate removal compared to passive recovery. Moreover, active recovery at 50% of maximal power output had better results in lactate clearance compared to the active recovery of lower intensity (25% of maximal power output).

Vitamin D: a necessity for children and adolescents in Greece.

Children and adolescents with the high bone turnover comprise a high risk population for vitamin D insufficiency. A sample of 178 clinically healthy children aged 3 to 18 years who came from public schools and lived in North West of Greece participated in the study. They were grouped into three age groups (I: 3-10, II: 11-14 and III: 15-18 years of age). Blood samples were taken during winter and summer months for determining calciotropic hormones, calcium, phosphate and biochemical markers of bone synthesis.A high percentage (47%) of the subjects aged 15-18 years was found to have 25OHD <10 ng/ml in winter but much less (13-14%) of the younger ages (13-14 years), while in the summer they were all >10 ng/ml. The prevalence was even higher in the girls of the older group accompanied by lower Pi concentrations again in winter (win:1.19+/-0.03, sum:1.93+/-0.03 mmol/l, p < 0.001). The 24,25(OH)(2)D levels were changing in parallel to 25OHD, but again in the older subjects, during winter, they were by 2/3 lower than the summer ones (0.73+/-0.10 vs. 2.41+/-0.20 ng/ml, p < 0.001). No significant differences were found between seasons and groups in the 1,25(OH)(2)D levels. The biochemical markers of bone synthesis, osteocalcin (OC) and total alkaline phosphatase (ALP), were found significantly lower in the girls of the older group both in winter and summer respectively. Even in a sunny country like Greece the adolescents living in an urban area are in high risk for vitamin D deficiency during winter. Supplementation with vitamin D of milk, of popular beverages and perhaps some foods would be of help.

Biochemical markers of bone metabolism in infants and children under intravenous corticosteroid therapy.

The short-term effects of corticosteroids (CS) administered intravenously (IV) on biochemical parameters of bone metabolism were followed in infants and children. Forty-nine patients from 2 months to 10 years of age, admitted to Pediatrics Department for bronchiolitis, viral-associated wheezing and croup, were treated with IV hydrocortisone or methylprednisolone (10 or 2 mg/Kg/day, respectively) for 3 days. Blood and fasting urine were collected on admission (day 1), 2 days later (day 3) and 12 days after the end of therapy (day 15). Fifty-one children of similar age and gender without respiratory problems or bone diseases were used as controls. On day 3, suppression of the bone formation markers osteocalcin (OC) (P < 0.001) and total alkaline phosphatase (ALP) (P < 0.05) was observed, but not of the bone resorption markers of hydroxyproline, pyridinoline and calcium excretion (UHyp/UCr, UPYD/UCr and UDPD/UCr, UCa/UCr). Significant decreases were indicated in serum phosphate (Pi) and the maximum renal tubular Pi reabsorption (TmP/GFR) compared to basal (P < 0.001). No significant changes were noticed in the circulating levels of calcium (Ca), parathyroid hormone (iPTH), 25OHD, 24,25(OH)2D, 1,25(OH)2D, the insulin-like growth factor-I (IGF-I) and its binding protein-3 (IGFBP-3). Two weeks after therapy, the increase of OC to higher than basal (P < 0.01) indicated a probable activation of the osteoblasts. Serum Pi and the TmP/GFR index values that had significantly decreased by day 3 returned to pretreatment levels by day 15. When assessing the effects of the CS in relation to age, no changes were detected in the levels of OC and total ALP in the <12-month-old children, but a fall of OC was observed in the >1-year-old group (P < 0.001). In contrast to the OC, the effects on serum and renal tubular reabsorption of phosphate were similar for both groups. In conclusion, short-term IV administered CS led to significant but reversible inhibition of bone formation markers, especially detectable in the >1-year-old children, without affecting the bone resorption ones. The adverse effects on phosphate metabolism were also significant, but temporal and irrespective of age.

Conventional MRI and magnetisation transfer imaging of tumour-like multiple sclerosis in a child.

Tumefactive multiple sclerosis is a rare entity in children. Differential diagnosis includes other mass lesions such as neoplasm and abscess. A case of tumefactive multiple sclerosis in a child is presented. The open-ring pattern of enhancement on conventional MRI and magnetisation transfer imaging was important for the initial diagnosis and the evaluation of the course of the disease.

Interleukin-3 and interleukin-4 in childhood brucellosis.

BACKGROUND: The Th1/Th2 cytokine balance seems to be involved in the susceptibility or resistance to Brucella infection, however the precise role of interleukins in human brucellosis has not been thoroughly explored. PATIENTS AND METHODS: The serum levels of interleukin-3 (IL-3) and interleukin-4 (IL-4) were measured by enzyme-linked immunosorbent assay (Quantikines, R&D Systems) in five children hospitalized for brucellosis and in a control group comprising ten children who were residents of the same area. RESULT: IL-4 levels were significantly increased during both the acute phase (p = 0.0036) and convalescence (p = 0.026) as compared to controls. IL-3 levels were mildly increased during the acute phase (p = 0.026) without any significant difference noted during convalescence (p = 0.271) as compared to controls. Both IL-3 and IL-4 levels were neither related to hemoglobin values, nor to red and white blood cell, neutrophil, lymphocyte and platelet counts. CONCLUSION: Serum IL-4 levels are increased in hospitalized children with symptomatic brucellosis, a finding suggestive of a Th2 response leading to severe infection.

A study of the growth-promoting and metabolic effects of growth hormone (GH) in a patient with the "growth without GH" syndrome.

The paradox of normal or even excessive growth despite a proven lack of GH is a well-known but still unexplained phenomenon that has been described in some patients following resection of a craniopharyngioma or other suprasellar tumours. However, the consequences of GH deficiency on other metabolic aspects of GH action in this syndrome have not been adequately investigated. The aim of this study was to examine whether a dissociation might exist between the growth-promoting and metabolic effects of GH. We studied a 7.1 year old boy who, after removal of a suprasellar craniopharyngioma, developed panhypopituitarism with mild hyperprolactinaemia. Despite the presence of severe GH deficiency associated with persistently low IGF-I and IGFBP-3 levels, the patient grew spontaneously at an accelerated rate for a prepubertal boy, achieving a height velocity of 9.0 cm during the first and 8.5 cm during the second post-operative year. However, other metabolic parameters of GH activity were adversely affected by the lack of GH. The maximum tubular reabsorption rate for phosphate over glomerular filtration rate ratio (2.8) was persistently low and normalized during a 4 day course of hGH administration (4.2) together with the normalization of IGF-I (from 34 microg/l to 294 microg/l), suggesting that GH-dependent renal phosphate handling is impaired in this syndrome. In addition, bone age was delayed by 1.7 years consistently with delayed skeletal maturation, whereas skinfold thickness and the waist to hip ratio were increased in comparison with normative data, suggesting increased adipose tissue mass with central fat distribution, a phenotype characteristic of GH deficiency. In conclusion, our case study suggests that, in the "growth without GH" syndrome, the excessive growth is independent of GH and dissociated from other GH-dependent metabolic effects, which are decreased.

Dysembryoplastic neuroepithelial tumour and cerebellar atrophy: case report.

Dysembryoplastic neuroepithelial tumours (DNET) are mainly benign cortical lesions. DNET in the caudate nucleus, thalamus, hypothalamus, pons and cerebellar hemispheres has also been reported. We describe a fronto-temporo-parietal DNET extending to the ipsilateral thalamus and internal capsule, associated with cerebellar lobe atrophy. Involvement of the internal capsule and complication of DNET with cerebellar atrophy have not been reported previously. We emphasise the importance of early diagnosis and treatment of this rare condition.

Streptococcus mitis septicaemia and hepatitis.

The case of an otherwise well 9-y-old boy with fever, papular rash, jaundice and impaired liver function is presented. Streptococcus mitis sensitive to penicillin grew in blood culture. The boy had an excellent outcome. The clinical spectrum of viridans streptococci may be wider than currently anticipated, and Streptococcus mitis may cause septicaemia and hepatitis in immunocompetent individuals.

Hemolytic uremic syndrome and thymic dysplasia in an infant.

A 33-day-old male infant was admitted to the neonatal intensive care nursery because of respiratory distress, grunting, cyanosis, and radiological findings of bilateral bronchopneumonia. He responded well to intensive therapy, but 11 days later developed hemolytic uremic syndrome, which was treated conservatively with prednisone and plasma transfusions with good response. The hemolytic uremic syndrome resolved, but he subsequently developed severe recurrent infections of unknown etiology and died at the age of 78 days. Necropsy findings revealed necrotizing enterocolitis as well as dysplasia of the thymus and other lymphoid tissues, compatible with the diagnosis of immunodeficiency disorder.

Effect of aminoglycoside therapy on renal function in full-term infants.

The effect of aminoglycosides on renal function was evaluated in 30 full-term infants who were treated within 24 h of birth with either amikacin (10 infants, group A), gentamicin (9 infants, group B), or netilmicin (10 infants, group C). Renal function was assessed before, during, and 48 h after discontinuation of therapy by measuring the plasma creatinine concentration (PCr), the fractional excretion of sodium (FENa), potassium, magnesium, phosphate (FEP), uric acid, and the urinary excretion of calcium (UCA/UCr ratio) immediately before (trough) and after (peak) the infusion of the aminoglycosides. The results were compared with 10 control newborns who did not receive antibiotics. Significant alterations in renal function were observed only during therapy with gentamicin (group B). These consisted of a sustained elevation of FENa and UCa/UCr ratio throughout therapy, a latent increase in FEP on the 7th day (P < 0.05), and lack of the normal postnatal decline of PCr in 3 of 9 infants (P < 0.01). These abnormalities persisted up to 2 days after discontinuation of therapy. Therapeutic doses of gentamicin may result in significant electrolyte disturbances in sick full-term infants.

Renal function in premature infants during aminoglycoside therapy.

The effect of three different aminoglycosides on renal function was evaluated in 30 premature infants of similar gestational age who were treated within 24 h of birth with either amikacin (10 infants, group A), gentamicin (10 infants, group B) or netilmicin (10 infants, group C), for a period of 7 days. Ten infection-free premature infants of similar post-conceptional age were used as controls. Serial determinations of plasma creatinine concentration (PCr), as well as the fractional excretion of sodium (FENa), potassium, magnesium (FEMg), phosphate (FEP) and uric acid (FEUA), and the urinary excretion of calcium (UCa/UCr ratio) were assessed before, during and after treatment. During the treatment period a significant increase in FENa, FEMg and UCa/UCr was observed in group B (P < 0.05 and P < 0.01, respectively) and an increase in FENa and UCa/UCr in group C (P < 0.01) compared with controls. These disturbances were observed with trough concentrations of aminoglycosides but were accentuated at peak serum concentrations and were restored to normal 2 days after stopping therapy. In addition, a significant correlation was demonstrated between FENa, FEMg and UCa/UCr ratio in treated patients. PCr levels decreased similarly in all patient groups, but in 8 of 30 infants (27%) they remained elevated and returned to control values only 10 days after stopping therapy. Such renal functional disturbances, although transient, may result in significant electrolyte and mineral imbalance in the sick premature infant.

Behavioural and biochemical effects of haloperidol during the oestrous cycle of the rat.

The effects of two doses (1 and 2 mg/kg, i.p.) of haloperidol (HAL) on catalepsy, on concentrations of DA and DOPAC in frontal cortex, nucleus accumbens and striatum and on serum levels of oestradiol were investigated in intact female rats during the 4-day oestrous cycle. Catalepsy induced by haloperidol did not vary much during phases of the cycle. The turnover of DA in the cortex induced by haloperidol was significantly greater on proestrus and smaller on oestrus. The effect of haloperidol on the turnover of DA in the nucleus accumbens and in striatum was marginally affected by the oestrous cycle being greatest on oestrus. The levels of serum oestradiol were higher on proestrus and lower on oestrus. No significant differences were detected between diestrus and metestrus. After haloperidol there was a dramatic increase in serum oestradiol on oestrus, a slight increase on metestrus and diestrus and a decrease on proestrus. However, serum levels of oestradiol were not significantly different between phases of the cycle in rats treated with haloperidol. The results indicate that the oestrous cycle has a detectable influence on DAergic mechanisms in the frontal cortex and possibly in the tuberoinfudibular system, brought about by treatment with haloperidol.

Chlorimipramine, electroconvulsive shock and combination thereof: differential effects of chronic treatment on apomorphine-induced behaviours and on striatal and mesocortical dopamine turnover.

We studied the influence of different pretreatment regimens (Chlorimipramine-Cmi, electroconvulsive shock-ECS, and Cmi + ECS all regimens being applied for either 2 or 15 days) on the open field behaviour, on the striatal and on the prefrontal dopamine-PFC DA turnover in rats injected with either apomorphine-AP 25 micrograms/kg (stimulating presynaptic DA receptors), AP 200 micrograms/kg (stimulating post-synaptic DA receptors), or vehicle (control). In the controls, AP 25 micrograms/kg reduced the locomotor activity and the striatal, but not the PFC DA turnover. AP 200 micrograms/kg increased the locomotor activity and reduced the striatal but not the PFC DA turnover. Short-term pretreatment: ECS and Cmi + ECS prevented the decrease of striatal DA turnover after AP 25 micrograms/kg. No other influence of any pretreatment on behaviour or DA-turnover became significant. Long-term pretreatment: Chronic Cmi: marginally increased the open field behaviour and marginally decreased the PFC DA turnover; significantly increased the effect of AP (200 micrograms/kg) on striatal DA turnover and the effect of AP (25 and 200 micrograms/kg) on PFC DA turnover. Repeated ECS: decreased locomotion and rearing and increased PFC DA turnover; increased the effect of AP (200 micrograms/kg) on locomotion and on striatal DA turnover; decreased the effect of AP (25 and 200 micrograms/kg) on PFC DA turnover. Chronic Cmi + ECS: decreased locomotion and rearing and marginally decreased PFC DA turnover; increased the effect of AP on hyperlocomotion and on striatal DA turnover.(ABSTRACT TRUNCATED AT 250 WORDS)