Protein synthesis and translation initiation factor activation in neonatal pigs fed increasing levels of dietary protein

Limited data suggest that the growth of low-birth-weight infants is enhanced by feeding a high-protein diet; however, the mechanisms involved in the effect have not been delineated. To identify these mechanisms, 34 pigs were fed from 2 to 7 d of age [60 g dry matter/(kg body weight . d)] isocaloric milk diets that contained levels of dietary protein that were marginal, adequate, and in excess of the piglets protein requirement (21, 33, and 45% of dry matter, respectively). Dietary protein replaced lactose and fat on an isocaloric basis. Fractional protein synthesis rates, various biomarkers of translational regulation, and plasma glucose and insulin levels were measured in overnight food-deprived and fed pigs. Mean daily weight gain of pigs fed the 33 and 45% protein diets was greater than that of pigs fed the 21% protein diet (P < 0.01). Plasma glucose (P = 0.07) and insulin (P < 0.01) levels decreased as dietary protein increased 60 min after feeding. Protein synthesis rates in longissimus dorsi, gastrocnemius, masseter, heart, liver, kidney, jejunum, and pancreas were greater in the fed than in the food-deprived state (P < 0.01). Protein synthesis in skeletal muscle did not change with protein intake in the fed state, but decreased quadratically (P < 0.01) with increasing dietary protein in the food-deprived state. Protein kinase B, ribosomal protein S6 kinase 1(S6K1), and eukaryotic initiation factor (eIF) 4E binding protein-1 (4E-BP1) were more phosphorylated, and assembly of the inactive eukaryotic initiation factor 4E . 4E-BP1 complex in muscle and liver was reduced in the fed state (P < 0.001) and were not consistently affected by dietary protein level. The results suggest that feeding stimulates protein synthesis, and this is modulated by the activation of initiation factors that regulate mRNA binding to the ribosomal complex. However, the provision of a high-protein diet that exceeds the protein requirement does not further enhance protein synthesis or translation initiation factor activation.     

Oral leucine administration stimulates protein synthesis in rat skeletal muscle

Oral administration of a single bolus of leucine in an amount equivalent to the daily intake (1.35 g/kg body wt) enhances skeletal muscle protein synthesis in food-deprived rats. To elucidate whether smaller amounts of leucine can also stimulate protein synthesis, rats were administered the amino acid at concentrations ranging from 0.068 to 1.35 g/kg body wt by oral gavage. Thirty minutes following the administration of doses of leucine as low as 0.135 g/kg body wt, skeletal muscle protein synthesis was significantly greater than control values. The increase in protein synthesis was associated with changes in the regulation of biomarkers of mRNA translation initiation as evidenced by upregulated phosphorylation of the translational repressor, eukaryotic initiation factor (eIF)4E-binding protein 1 (4E-BP1), the association of eIF4G with the mRNA cap binding protein eIF4E, and the phosphorylation of the 70-kDa ribosomal protein S6 kinase. Alterations in the phosphorylation of eIF4G, as well as the association of 4E-BP1 with eIF4E, were observed following leucine administration; however, these changes appeared to be biphasic with maximal changes occurring when circulating insulin concentrations were elevated. Thus it appears that leucine administration affects mRNA translation and skeletal muscle protein synthesis through modulation of multiple biomarkers of mRNA translation. The ability of small doses of leucine to stimulate skeletal muscle protein synthesis suggests that future research on the regulation of skeletal muscle protein synthesis by orally administered leucine will be feasible in humans.     

Epidural morphine does not affect the duration of action of epidural 2-chloro-procaine following Caesarean section

The effect of epidural morphine on the duration of action of epidural 2-chloroprocoine was studied in a double-blind fashion in 30 patients following elective Caesarean section. When compared to epidural saline controls (n = 15), patients (n - 15) who received epidural morphine (4.0-5.0 m g) did not experience a prolongation or reduction in the duration of the somatic or sympathetic nervous system blockades produced by epidural 2-ckloro-procaine.     

Encephalitis and polyneuritis complicating varicella zoster infection

A 70-year-old patient is described who developed symptoms and signs of a Guillain-Barré-type neuropathy and encephalopathy beginning 6 weeks after a cutaneous varicella zoster eruption. The patient made a complete symptomatic recovery over a period of 4 months. It is suggested that the delayed onset neuropathy and encephalopathy in this patient may have been due to an allergic inflammatory response to an antigen common to peripheral and central myelin.     

Low adrenal androgenic-anabolic steroids in women with rheumatoid arthritis (RA): gas-liquid chromatographic studies of RA patients and matched normal control women indicating decreased 11-deoxy-17-ketosteroid excretion

Using GLC, multiple adrenal corticosteroid urinary metabolites, including androgenic-anabolic, glucocorticoid, pregnanediol, and pregnanetriol, were measured in eight ambulatory female RA patients and eight matched normal control subjects on baseline, ACTH-, and metyrapone-stimulation days under carefully monitored clinical research center protocol. Neither group had been treated previously with any steroid hormones. The 11-deoxy-17-KS metabolites, derived from adrenal androgenic-anabolic steroids, and comprising androsterone, etiocholanolone, and DHA, were significantly lower in RA patients on baseline (P less than .001), ACTH (P less than .005)-, and metyrapone (P less than .02)-stimulation days. To the contrary, the 11-oxy-17-KS metabolites, derived mainly from glucocorticoids, showed some lowered excretion at baseline (P less than .05), but none on ACTH- or metyrapone-stimulation. RA patients had lower tetrahydrocortisone (P less than .001) and tetrahydro-11-deoxycortisol (P less than .01) excretion at baseline, but not during ACTH- or metyrapone-stimulation, than control subjects. Pregnanetriol excretion was lower (P less than .005) in RA patients than control subjects only during ACTH-stimulation. No difference was found between groups in tetrahydrocortisol or pregnanediol excretion on any day studied. Under conditions of oral metyrapone administration (750 mg every four hours for seven doses) each control subject increased their DHA excretion, but no RA patient showed an increase over baseline excretion (P less than .02). Except for 11-deoxy-17-KS, no difference was found in the other metabolites studied during metyrapone stimulation, ie, pregnanediol, pregnanetriol, tetrahydro-11-deoxycortisol, and tetrahydrocortisol. The 24-hour oral metyrapone test provided a greater stimulus to total 11-deoxy-17-KS excretion than an eight-hour intravenous ACTH test in control and particularly RA (P less than .01) subjects even though the DHA excretion decreased in the RA groups. Our findings of lower adrenal androgenic-anabolic metabolite excretion in female RA patients than normal matched control subjects under various conditions and other supportive androgenic hormone and metabolite studies reviewed in the English reports suggest an abnormality of adrenal androgen synthesis or metabolism in RA, whether it be a primary predisposing or secondary factor in disease. The recognized female sex preponderance and age-specific patterns of occurrence of RA are consistent with adrenal androgenic function in adrenarche, adrenopause, and later changes in aging. Metabolite excretion patterns at baseline, ACTH-, and metyrapone- stimulation indicate the greatest relative     

Neuroimaging and cardiac correlates of cognitive function among patients with cardiac disease

In the present study, we examined the relationships between whole brain volume (WBV), subcortical hyperintensities (SH), indices of cardiac disease and cognitive function in nondemented cardiac patients with evidence of mild cerebrovascular disease. A total of 27 individuals with evidence of cardiac disease underwent neuropsychological examination, neuroimaging, and cardiac assessment. Cognition was assessed with the Dementia Rating Scale-2 (DRS). WBV and SH were quantified using a semi-automated thresholding program based on MRI. Correlational analyses revealed that WBV predicted performance on the overall DRS score, the attention subscale and the initiation/perseveration scale. SH were significantly associated with performance on the attention subscale, and the initiation/perseveration subscale. Regression analyses revealed that SH accounted for most of the variance in the initiation/perseveration scale, whereas WBV accounted for most of the variance in the attention scale. The only cardiac structural or functional variable related to the neurological indices was aortic diameter, which was strongly related to both neuroimaging variables, as well as performances on the DRS attention and initiation/perseveration subscales. Our results highlight the importance of overall brain parenchyma in determining cognitive status among patients at risk for cognitive decline and suggest that select indices of structural cardiac morphology may be related to the early phases of cerebrovascular disease and cognitive status.     

Unilateral subthalamic nucleus deep brain stimulation contralateral to thalamic stimulation in Parkinson disease

The effects of unilateral subthalamic nucleus (STN) stimulation contralateral to thalamic stimulation in Parkinson disease (PD) have not been previously reported. We are reporting a patient who developed left arm tremor in 1994, at age 62, as her first PD symptom. She underwent right thalamic DBS surgery in 1999 that resulted in complete resolution of left arm tremor. Her PD symptoms progressed and she developed severe motor fluctuations and disabling dyskinesias. In 2003, she underwent left STN electrode implantation. Left STN stimulation improved contralateral motor scores in the medication OFF state, and allowed for reduced medication doses and less dyskinesia. However, there was no significant improvement in activities of daily living (ADL), motor scores in the medication ON state, gait, or postural stability.     

Autoimmune thyroiditis in 18q deletion syndrome

Deletion of a segment of the long arm of chromosome 18 causes characteristic physical features and mental retardation. Autoimmune disorders have been described with this syndrome in a limited number of reports. We describe 2 cases of autoimmune hypothyroidism in children with 18q deletion syndrome.