Sleep restriction reduces voluntary isometric quadriceps strength through reduced neuromuscular efficiency, not impaired contractile performance.

Acute sleep restriction (SR) reduces strength through an unknown mechanism. PURPOSE: To determine how SR affects quadriceps contractile function and recruitment. METHODS: Eighteen healthy subjects (9 M, 9F, age 23.8 ± 2.8y) underwent isometric (maximal and submaximal), isokinetic (300-60°·s-1), and interpolated twitch (ITT) assessment of knee extensors following 3d of adequate sleep (SA; 7-9 h·night-1), 3d of SR (5 h·night-1), and 7d of washout (WO; 7-9 h·night-1). RESULTS: Compared to SA (227.9 ± 76.6Nm) and WO (228.19 ± 62.9Nm), MVIC was lesser following SR (209.9 ± 73.9Nm; p = 0.006) and this effect was greater for males (- 9.8 v. - 4.8%). There was no significant effect of sleep or sleep x speed interaction on peak isokinetic torque. Peak twitch torque was greater in the potentiated state, but no significant effect of sleep was noted. Males displayed greater potentiation of peak twitch torque (12 v. 7.5%) and rate of torque development (16.7 v. 8.2%) than females but this was not affected by sleep condition. ITT-assessed voluntary activation did not vary among sleep conditions (SA: 81.8 ± 13.1% v. SR: 84.4 ± 12.6% v. WO 84.9 ± 12.6%; p = 0.093). SR induced a leftward shift in Torque-EMG relationship at high torque output in both sexes. Compared to SA, females displayed greater y-intercept and lesser slope with SR and WO and males displayed lesser y-intercept and greater slope with SR and WO. CONCLUSIONS: Three nights of SR decreases voluntary isometric knee extensor strength, but not twitch contractile properties. Sex-specific differences in neuromuscular efficiency may explain the greater MVIC reduction in males following SR.

Activated Notch counteracts Ikaros tumor suppression in mouse and human T-cell acute lymphoblastic leukemia.

Activating NOTCH1 mutations occur in ~60% of human T-cell acute lymphoblastic leukemias (T-ALLs), and mutations disrupting the transcription factor IKZF1 (IKAROS) occur in ~5% of cases. To investigate the regulatory interplay between these driver genes, we have used a novel transgenic RNA interference mouse model to produce primary T-ALLs driven by reversible Ikaros knockdown. Restoring endogenous Ikaros expression in established T-ALL in vivo acutely represses Notch1 and its oncogenic target genes including Myc, and in multiple primary leukemias causes disease regression. In contrast, leukemias expressing high levels of endogenous or engineered forms of activated intracellular Notch1 (ICN1) resembling those found in human T-ALL rapidly relapse following Ikaros restoration, indicating that ICN1 functionally antagonizes Ikaros in established disease. Furthermore, we find that IKAROS mRNA expression is significantly reduced in a cohort of primary human T-ALL patient samples with activating NOTCH1/FBXW7 mutations, but is upregulated upon acute inhibition of aberrant NOTCH signaling across a panel of human T-ALL cell lines. These results demonstrate for the first time that aberrant NOTCH activity compromises IKAROS function in mouse and human T-ALL, and provide a potential explanation for the relative infrequency of IKAROS gene mutations in human T-ALL.

Pro-apoptotic Bim suppresses breast tumor cell metastasis and is a target gene of SNAI2.

Evasion of cell death is fundamental to the development of cancer and its metastasis. The role of the BCL-2-mediated (intrinsic) apoptotic program in these processes remains poorly understood. Here we have investigated the relevance of the pro-apoptotic protein BIM to breast cancer progression using the MMTV-Polyoma middle-T (PyMT) transgenic model. BIM deficiency in PyMT females did not affect primary tumor growth, but substantially increased the survival of metastatic cells within the lung. These data reveal a role for BIM in the suppression of breast cancer metastasis. Intriguingly, we observed a striking correlation between the expression of BIM and the epithelial to mesenchymal transition transcription factor SNAI2 at the proliferative edge of the tumors. Overexpression and knockdown studies confirmed that these two genes were coordinately expressed, and chromatin immunoprecipitation analysis further revealed that Bim is a target of SNAI2. Taken together, our findings suggest that SNAI2-driven BIM-induced apoptosis may temper metastasis by governing the survival of disseminating breast tumor cells.

GB/SA water model for the Merck molecular force field (MMFF).

A revised generalized Born/surface area (GB/SA) continuum solvation model has been developed for water that is compatible with the Merck molecular force field (MMFF). This model gives free energies of aqueous solvation that are comparable in accuracy to the original water model when the OPLS* force field is employed. The average unsigned error in aqueous deltaGsol using the new water model and MMFF is 0.62 kcal/mol for a training set of 82 solutes compared to 1.24 kcal/mol for the original GB/SA water model and MMFF. The average unsigned errors for 47 neutral solutes outside the training set and 10 ions are 0.96 and 2.32 kcal/mol, respectively. By comparison, the average errors for the test set and ions using the original GB/SA water model are 1.76 and 5.32 kcal/mol. This revised parameter set provides a more accurate representation of aqueous solvation for use with MMFF.

Rehabilitation after subcutaneous transposition of the ulnar nerve: immediate versus delayed mobilization.

We studied 36 patients who had clinical signs and symptoms consistent with cubital tunnel syndrome and in whom nonoperative management failed. These patients underwent anterior subcutaneous transposition of the ulnar nerve followed by either immediate (20 patients) or delayed (16 patients) mobilization. All patients were evaluated with an outcomes assessment questionnaire, and 35 of the 36 were given repeat physical examinations. After surgery, there were no significant differences between the two groups in pain relief, weakness, or patient satisfaction (71% of the immediate mobilization group and 74% of the delayed group) were satisfied. Secondary quantitative outcomes such as grip strength, lateral pinch, or two-point discrimination were also not significantly different between the groups. Both groups had a statistically significant improvement in first dorsal interosseous and adductor pollicis muscle strength. In the immediate mobilization group, however, patients returned to work and resumed activities of daily living earlier (median 1 month) than patients in the delayed mobilization group (median 2.75 months). Therefore, we conclude that anterior subcutaneous transposition provides a high degree of satisfaction and relief of symptoms regardless of when mobilization is initiated. However, immediately mobilizing the patient significantly influenced how early the patient returned to work and resumed activities of daily living.

Assessment of growth hormone (GH) secretion in men with adult-onset GH deficiency compared with that in normal men--a clinical research center study.

It is not known how patients who acquire GH deficiency (GHD) in adulthood differ in measures of GH secretion from normal adults. To characterize measures of GH secretion in such patients compared to those in normal subjects, we studied 23 men (median age, 51 yr; range, 32-62 yr) with adult-onset pituitary disease, defined as GH-deficient based on having no detectable GH response to two pharmacological agents, and 17 normal men. Patients less than 50 yr old received insulin (0.1 U/kg, i.v.) and clonidine (0.15 mg, orally), whereas those 50 yr of age or older as well as normal controls received arginine (30 g, i.v.) and clonidine. Patients were compared to normal men by investigating GH sampling every 10 min for 24 h and serum levels of insulin-like growth factor I (IGF-I), IGF-binding protein 2 (IGFBP-2), IGFBP-3, and GH-binding protein. Frequent venous sampling of GH was analyzed in terms of mean 24-h levels, pooled 24-h GH, mean levels over the 12 h between 2000-0800 h (mean overnight GH level), and pulse analysis (pulses per 24 h and pulse amplitude) by the Pulsar computer program. Although there were significant differences between the two groups for almost all measures of GH secretion, overlap between the groups was always present. GH levels measured using a highly sensitive chemiluminescence assay on 24-h pools derived from frequent sampling displayed the least overlap between the two groups, as only 2 of 17 normal controls overlapped with the GHD patients. The pooled 24-h GH level using this technique was significantly lower in patients with GHD than in controls (0.117 +/- 0.021 vs. 0.861 +/- 0.098 micrograms/L; P < 0.0001). In the analysis of frequent GH sampling using a standard immunoradiometric assay, mean overnight GH levels provided the best separation between the two groups, as all 23 patients had values of 0.6 microgram/L or less, and 13 of 17 normal controls had values greater than 0.6 microgram/L. The mean overnight GH level in patients was 0.6 +/- 0.0 microgram/L compared to 1.0 +/- 0.1 microgram/L in controls (P < 0.0001). The mean 24-h GH level in patients was 0.5 +/- 0.0 microgram/L compared to 0.8 +/- 0.1 microgram/L in normal controls (P < 0.0001). GH pulse frequency and pulse amplitude were also reduced in patients with GHD compared to those in normal controls [1.7 +/- 0.5 vs. 5.1 +/- 0.5 pulses/24 h (P < 0.0001) and 0.6 +/- 0.1 vs. 2.8 +/- 0.4 microgram/L (P < 0.0001), respectively]. The mean serum IGF-I level was significantly lower in patients with GHD than in normal controls (106.7 +/- 8.0 vs. 218.7 +/- 16.7 microgram/L; P < 0.0001). Three of 23 patients overlapped with control values. Mean serum levels of IGFBP-3 and the serum IGF-I/IGFBP-2 ratio were also significantly lower in patients than in controls, but values overlapped substantially. We conclude that overlap occurs on measures of GH secretion between normal men and men identified as GH deficient despite a stringent definition of GHD. The best separation was obtained using pooled 24-h GH levels determined by a highly sensitive chemiluminescence assay.

The determination of hydroxydopamines and other trace amines in the urine of parkinsonian patients and normal controls.

5- and 6-Hydroxydopamine, which we had earlier identified as naturally occurring amines in human urine, were quantified in Parkinson's patients treated with L-DOPA, Parkinson's patients whose treatment did not include L-DOPA and in age matched controls. Analysis was carried out by GC-MS of the ditrifluoromethylbenzoyl-trimethylsilyl (DTFMB-TMS) derivatives of the compounds. The concentrations of 5- and 6-hydroxydopamine in the urine of DOPA treated Parkinson's patients were significantly higher than the concentrations from patients not treated and from normal controls. Urinary dopamine levels were greatly elevated in DOPA treated Parkinson's patients while p-tyramine levels were suppressed. No marked differences were seen between the three groups in terms of the urinary concentrations of any of the other amines measured.

Analysis of biogenic amines in plasma of hypertensive patients and a control group.

Procedures were developed for the determination of 17 circulating amines using gas chromatography-negative ion chemical ionisation mass spectrometry. The amines were quantified against their appropriate deuterated isotopomers. The mean concentrations and ranges of catecholamines and trace amines were high compared with previous studies. In comparison with nonhypertensives, plasma from hypertensives had higher concentrations of the following amines: noradrenaline (t = 4.0%); normetanephrine (t = 6.1%) and metanephrine (t = 1.9%). There were no significant differences between 5HT levels in plasma from hypertensives and controls. The following trace amines could be detected in variable amounts in plasma: p-tyramine, m-tyramine, p-octopamine, m-octopamine, p-synephrine, m-synephrine, and salsolinol. The trace amines melatonin, N-acetyl 5HT, tryptamine, 6-hydroxymelatonin and 5-methoxytryptamine could not be detected in plasma with limits of detection lying in the range 20-100 pg ml-1.

The determination of 5-hydroxytryptamine, related indolealkylamines and 5-hydroxyindoleacetic acid in the bovine eye by gas chromatography-negative ion chemical ionization mass spectrometry.

Methods were developed for the analysis of 5-hydroxytryptamine, related indolealkylamines (tryptamine, melatonin, 5-methoxytryptamine, N-acetyl-5-hydroxytryptamine and 6-hydroxymelatonin) and 5-hydroxyindole-3-acetic acid (5HIAA) in bovine retina, aqueous and vitreous humours. 5-Hydroxytryptamine and related indolealkylamines were extracted and derivatized to form their corresponding pentafluoropropionyl spirocyclic derivatives. 5HIAA was extracted and derivatized to the corresponding pentafluoropropionamide-trifluoroethyl derivative. Identification and quantitation by gas chromatography-negative ion chemical ionization mass spectrometry was made with reference to deuteriated internal standards. 5-Hydroxytryptamine was present in all (n = 34) retinal samples analysed (20.53 +/- 1.64 ng) while N-acetyl-5-hydroxytryptamine was detected in half of the samples of retina (0.06 +/- 0.02 ng). Melatonin (0.15 +/- 0.06 ng) and tryptamine (0.78 +/- 0.34 ng) were detected in only a small number of retinas. 5-Methoxytryptamine was not present in retina. 5-Hydroxytryptamine was also present in aqueous (0.76 +/- 0.17 ng ml-1 and vitreous (0.35 +/- 0.05 ng ml-1' humours from bovine eye. Tryptamine, melatonin, 5-methoxytryptamine and N-acetyl-5-hydroxytryptamine were not detected in bovine aqueous and vitreous humours. 5HIAA was found in both bovine aqueous (2.03 +/- 0.38 ng ml-1) and vitreous (0.65 +/- 0.06 ng ml-1) humours, but its consistent determination in retina was obviated by interference from spurious peaks.