Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu_{3}O_{3}.

LiCu_{3}O_{3} is an antiferromagnetic mixed valence cuprate where trilayers of edge-sharing Cu(II)O (3d^{9}) are sandwiched in between planes of Cu(I) (3d^{10}) ions, with Li stochastically substituting Cu(II). Angle-resolved photoemission spectroscopy (ARPES) and density functional theory reveal two insulating electronic subsystems that are segregated in spite of sharing common oxygen atoms: a Cu d_{z^{2}}/O p_{z} derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3d_{x^{2}-y^{2}}/O 2p_{x,y} derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes. First-principle analysis shows the Li substitution to stabilize the insulating ground state, but only if antiferromagnetic correlations are present. Li further induces substitutional disorder and a 2D electron glass behavior in charge transport, reflected in a large 530 meV Coulomb gap and a linear suppression of VB spectral weight at E_{F} that is observed by ARPES. Surprisingly, the disorder leaves the Cu(II)-derived ZRS largely unaffected. This indicates a local segregation of Li and Cu atoms onto the two separate corner-sharing Cu(II)O_{2} sub-lattices of the edge-sharing Cu(II)O planes, and highlights the ubiquitous resilience of the entangled two hole ZRS entity against impurity scattering.

More evidence on TRIO missense mutations in the spectrin repeat domain causing severe developmental delay and recognizable facial dysmorphism with macrocephaly.

TRIO is a Dbl family guanine nucleotide exchange factor (GEF) and an important regulator of neuronal development. Most truncating and missense variants affecting the Dbl homology domain of TRIO are associated with a neurodevelopmental disorder with microcephaly (MIM617061). Recently, de novo missense variants affecting the spectrin repeat region of TRIO were associated with a novel phenotype comprising severe developmental delay and macrocephaly (MIM618825). Here, we provide more evidence on this new TRIO-associated phenotype by reporting two severely affected probands with de novo missense variants in TRIO affecting the spectrin repeat region upstream of the typically affected GEF1 domain of the protein.

Genetic and phenotypic characterization of NKX6-2-related spastic ataxia and hypomyelination.

BACKGROUND AND PURPOSE: Hypomyelinating leukodystrophies are a heterogeneous group of genetic disorders with a wide spectrum of phenotypes and a high rate of genetically unsolved cases. Bi-allelic mutations in NKX6-2 were recently linked to spastic ataxia 8 with hypomyelinating leukodystrophy. METHODS: Using a combination of homozygosity mapping, exome sequencing, and detailed clinical and neuroimaging assessment a series of new NKX6-2 mutations in a multicentre setting is described. Then, all reported NKX6-2 mutations and those identified in this study were combined and an in-depth analysis of NKX6-2-related disease spectrum was provided. RESULTS: Eleven new cases from eight families of different ethnic backgrounds carrying compound heterozygous and homozygous pathogenic variants in NKX6-2 were identified, evidencing a high NKX6-2 mutation burden in the hypomyelinating leukodystrophy disease spectrum. Our data reveal a phenotype spectrum with neonatal onset, global psychomotor delay and worse prognosis at the severe end and a childhood onset with mainly motor phenotype at the milder end. The phenotypic and neuroimaging expression in NKX6-2 is described and it is shown that phenotypes with epilepsy in the absence of overt hypomyelination and diffuse hypomyelination without seizures can occur. CONCLUSIONS: NKX6-2 mutations should be considered in patients with autosomal recessive, very early onset of nystagmus, cerebellar ataxia with hypotonia that rapidly progresses to spasticity, particularly when associated with neuroimaging signs of hypomyelination. Therefore, it is recommended that NXK6-2 should be included in hypomyelinating leukodystrophy and spastic ataxia diagnostic panels.

Selective beta-1 receptor blockade with oral practolol in man. A dose-related phenomenon.

The purpose of this study was to test the hypothesis that oral administration of a low dose of practolol in man produces selective beta-1 receptor blockade, whereas oral administration of a high dose blocks both beta-1 and beta-2 receptors. Normal men were studied 2-4 h after a single oral dose of practolol (1.5 or 12 mg/kg) and after placebo. Effects on beta-1 receptors were studied by measuring heart rate responses to exercise. Effects on beta-2 receptors were tested by measuring forearm vascular responses to brachial arterial infusions of isoproterenol. Neither dose of practolol altered base-line heart rate, forearm vascular resistance, and arterial pressure, Both low and high doses significantly attenuated heart rate responses to exercise. Forearm vasodilator responses to isoproterenol were attenuated by the high dose, but not the low dose, of practolol. Serum concentrations of practolol 2 h after administration of the drug and at the time of the studies of forearm vascular responses averaged 0.5+/-0.1 (SE) and 5.9+/-1.0 mug/ml for low and high doses of practolol, respectively. The results indicate that the phenomenon of selective beta-1 receptor blockade in man is related to the dose and serum concentration of practolol selectively block beta-1 receptors; a high dose and serum concentrations block both beta-1 and beta-2 receptors.

[Three-stage method in lung scintigraphy: ventilation, diffusion and perfusion (author's transl)]. / Drei-Schritt-Untersuchung in der Lungenszintigraphie: Ventilation, Diffusion und Perfusion

A combination of three stages--ventilation, "perfusion" and diffusion-- has proved to be the optimal method in the scientigraphic exmaination of the lung. 85mCrypton is preferred for ventilation studies compared with 133Xenon, in view of its more suitable radiation energy and lower solubility. In the pre and post-operative investigation of the lungs, ventilation estimations are essential, providing a more reliable perameter than "perfusion estimations". The results from "perfusion" measurements with MAA or microspheres frequently do not correspond with those obtained by 133Xenon. It is still debatable whether the use of MAA or microspheres provide perfusion values and it would be better at present to speak of MAA fixation results.

Self-care assessment: key to teaching and discharge planning.

Patient education research supports the premise that the nurse must consider the patient's perspective before attempting to provide an educational program for implementing the therapeutic regimen. This article describes how a self-care assessment instrument can help the nurse to develop an individualized teaching plan for the cardiac patient.

Chronic obstructive pulmonary disease: current comprehensive care for emphysema and bronchitis.

Chronic obstructive pulmonary disease (COPD) is the fifth leading cause of mortality in the United States. Most clients are initially seen when symptomatic and significant lung damage has already occurred; most cases are preventable. There is no cure for COPD, but lifestyle changes (especially smoking cessation) and proper treatment can significantly impact quality of life. The diagnostic tools most commonly used include chest x-ray, arterial blood gases, and pulmonary function tests. Pharmacologic interventions include steroids, bronchodilators, mucolytics, and an armamentarium of antibiotics, which must be selected with careful discretion. Because the prognosis of COPD may be guarded, the practitioner is obligated to provide information on advance directives. A sensitive approach, holistic perspective, consistent follow-up, and clinical astuteness are essential ingredients in the management of clients with COPD.

Pressure ulcer incidence and severity in a community hospital.

In a study of 1320 adult patients admitted to a community hospital, there was a pressure ulcer incidence rate of 8.4%, with 3.2% of pressure ulcers present on admission. Of the 190 ulcers found, 63% (n = 120) were hospital acquired and were less severe than those present on admission. There was an average of 1.6 ulcers per patient; 56.3% (n = 107) were Stage I ulcers and 36.3% (n = 69) were Stage II ulcers. The most frequent sites were coccyx-sacral area, heels, and elbows. Preventive measures used most frequently were turning, special mattresses, and special skin care. After a pressure ulcer developed, the most frequently used treatment measures were special bed or mattress, frequent turning, and special ointments and dressings.

Interrater reliability of the Tinetti Balance Scores in novice and experienced physical therapy clinicians.

OBJECTIVE: To examine interrater agreement of scores by physical therapy novices and experienced clinicians on videotaped and live performances of the balance portion of Tinetti's Performance Oriented Mobility Assessment (BPOMA). DESIGN: A reliability design was used to assess the interrater agreement and consistency of the BPOMA scores in an elderly population. SETTING: General community hospital and skilled nursing facility. PATIENTS: Twenty-six residents of a skilled nursing home, ranging in age from 66 to 99 yrs (mean = 80.4, SD = 6.8), participated in Phase 1. Twenty-four hospital inpatients and five residents of a skilled nursing home, ranging in age from 60 to 92 yrs (mean = 74.7, SD = 7.9), participated in Phase 2. RATERS: Three student physical therapists scored the patients in Phase 1. One student was designated the administrating rater (AR). The AR instructed, guarded, and scored the subjects. The other two students were the observing raters (ORs), whose role was to observe and score the subject's performances. Nine physical therapy clinicians, ranging from 0 to 6 years of experience, rated subjects in Phase 2. MAIN OUTCOME MEASURES: Consistency and agreement of BPOMA scores were compared between clinicians with varying levels of experience. In Phase I, BPOMA was scored on-site by three student physical therapists. In Phase 2, videotaped performances were scored by five physical therapists, one physical therapist assistant, and three student physical therapists. RESULTS: Phase 1 demonstrated fair to excellent kappa coefficients (.40-1.00) in all maneuvers across all raters. The ORs had higher agreement compared with the AR, ranging from good to excellent (.75-1.00). Phase 2 demonstrated fair to good kappa coefficients (.40-.75) in 5 of 8 maneuvers across all nine raters. When comparing proportion of observed agreement to evaluate the years of experience on rater agreement, there was no significant difference between clinician groups. CONCLUSIONS: Fair to good reliability of BPOMA scores occurred across many rates of varied experience with a small amount of training.

Efferent pathways of the coronary chemoreflex.

This study was performed to identify the efferent pathways which mediate vasodilation during activation of the coronary chemoreflex and to compare the reflex responses in vessels in skeletal muscle and skin. Reflex vasodilator responses (decreases in perfusion pressure) were measured in innervated, perfused gracilis muscle and hindpaw of dogs during activation of the coronary chemoreflex with intracoronary injections of nicotine. Reflex vasodilator responses to intracoronary nicotine (1.25 and 2.50 mu-g per kilogram) averaged -14 plus or minus 5 (S.E.M.) and -34 plus or minus 6 mm. Hg, respectively, in muscle, but only -5 plus or minus 2 and -10 plus or minus 4 mm. Hg, respectively, in paw. Atropine, tripelennamine, and propranolol did not alter the vasodilation. Guanethidine blocked reflex vasodilation in muscle. The reflex vasodilator responses in paw were slight and were not significantly attenuated by guanethidine. The results indicate that sympathetic cholinergic pathways to skeletal muscle do not participate in the coronary chemoreflex. The reflex vasodilation in muscle results from withdrawal of adrenergic constrictor tone. The efferent pathway demonstrates that the coronary chemoreflex does not produce striking withdrawal of adrenergic tone in paw. The results indicate, therefore, that activation of the coronary chemoreflex results in greater withdrawal of adrenergic constrictor tone and greater vasodilation in muscle than in skin.