Measuring Coping in Parents of Children with Disabilities: A Rasch Model Approach

Background

Parents of a child with disability must cope with greater demands than those living with a healthy child. Coping refers to a person’s cognitive or behavioral efforts to manage the demands of a stressful situation. The Coping Health Inventory for Parents (CHIP) is a well-recognized measure of coping among parents of chronically ill children and assesses different coping patterns using its three subscales. The purpose of this study was to provide further insights into the psychometric properties of the CHIP subscales in a sample of parents of children with disabilities.

Methods

In this cross-sectional study, 220 parents (mean age, 33.4 years; 85% mothers) caring for a child with disability enrolled in special schools as well as in mainstream schools completed the 45-item CHIP. Rasch analysis was applied to the CHIP data and the psychometric performance of each of the three subscales was tested. Subscale revision was performed in the context of Rasch analysis statistics.

Results

Response categories were not used as intended, necessitating combining categories, thereby reducing the number from 4 to 3. The subscale – ‘maintaining social support’ satisfied all the Rasch model expectations. Four item misfit the Rasch model in the subscale –maintaining family integration’, but their deletion resulted in a 15-item scale with items that fit the Rasch model well. The remaining subscale – ‘understanding the healthcare situation’ lacked adequate measurement precision (<2.0 logits).

Conclusions

The current Rasch analyses add to the evidence of measurement properties of the CHIP and show that the two of its subscales (one original and the other revised) have good psychometric properties and work well to measure coping patterns in parents of children with disabilities. However the third subscale is limited by its inadequate measurement precision and requires more items.     

Molecular docking analysis of CDK-1 inhibitors from Chrysophyllum cainito leaves

It is of interest to document the molecular docking analysis of Cyclin-dependent kinase 1 (CDK-1) inhibitors from Chrysophyllum cainito leaves towards the treatment of tumors using the known structure of PDB ID: 5HQ0. Data shows that molecules such as 8- (Dimethylamino)-7-(3-(4-ethylphenoxy)-2d, ethyl 6-oxo-5-propylheptanoate, 2,3-dihydro-3, 5-dihydroxy-6-methyl-4h-pyran-4-one, 1,2,3-benzenetriol and 1,4-benzenediol 2,5-bis (1,1-dimethylethyl) identified in methanolic extract of C. cainito have binding features with CDK1 for further consideration.     

D:b-friedoolean-5-ene-3β,29-diol,an angular methyl oxygenated d: b-friedooleanene from elaeodendron balae

A new dioxygenated D: B-friedooleanene from Elaeodendron balae root bark was shown to be D:B–friedoolean-5-ene-3β,29-diol by relating it to 29-oxygenated D:A-friedooleanane. This is the first report of angular methyl oxygenation in the D: B-friedooleananes.     

The nature of information, required for export and sorting, present within the outer membrane protein OmpA of Escherichia coli K-12.

Information, in addition to that provided by signal sequences, for translocation across the plasma membrane is thought to be present in exported proteins of Escherichia coli. Such information must also exist for the localization of such proteins. To determine the nature of this information, overlapping inframe deletions have been constructed in the ompA gene which codes for a 325-residue major outer membrane protein. In addition, one deletion, encoding only the NH2-terminal part of the protein up to residue 160, was prepared. The location of each product was determined by immunoelectron microscopy. Proteins missing residues 4-45, 43-84, 46-227, 86-227 or 160-325 of the mature protein were all efficiently translocated across the plasma membrane. The first two proteins were found in the outer membrane, the others in the periplasmic space. It has been proposed that export and sorting signals consist of relatively small amino acid sequences near the NH2 terminus of an outer membrane protein. On the basis of sequence homologies it has also been suggested that such proteins possess a common sorting signal. The locations of the partially deleted proteins described here show that a unique export signal does not exist in the OmpA protein. The proposed common sorting signal spans residues 1-14 of OmpA. Since this region is not essential for routing the protein, the existence of a common sorting signal is doubtful. It is suggested that information both for export (if existent) and localization lies within protein conformation which for the former process should be present repeatedly in the polypeptide.     

A vanadate-stimulated NADH oxidase in erythrocyte membrane generates hydrogen peroxide

Summary Oxidation of NADH by rat erythrocyte plasma membrane was stimulated by about 50-fold on addition of decavanadate, but not other forms of vanadate like orthovanadate, metavanadate aad vanadyl sulphate. The vanadate-stimulated activity was observed only in phosphate buffer while other buffers like Tris, acetate, borate and Hepes were ineffective. Oxygen was consumed during the oxidation of NADH and the products were found to be NAD⁺ and hydrogen peroxide. The reaction had a stoichiometry of one mole of oxygen consumption and one mole of H₂O₂ production for every mole of NADH that was oxidized.Superoxide dismutase and manganous inhibited the activity indicating the involvement of superoxide anions. Electron spin resonance in the presence of a spin trap, 5, 5-dimethyl pyrroline N-oxide, indicated the presence of superoxide radicals. Electron spin resonance studies also showed the appearance of V^IV species by reduction of V^V of decavanadate indicating thereby participation of vanadate in the redox reaction. Under the conditions of the assay, vanadate did not stimulate lipid peroxidation in erythrocyte membranes. Extracts from lipid-free preparations of the erythrocyte membrane showed full activity. This ruled out the possibility of oxygen uptake through lipid peroxidation. The vanadate-stimulated NADH oxidation activity could be partially solubilized by treating erythrocyte membranes either with Triton X-100 or sodium cholate. Partially purified enzyme obtained by extraction with cholate and fractionation by ammonium sulphate and DEAE-Sephadex was found to be unstable.     

Localization of the ornithine aminotransferase gene and related sequences on two human chromosomes

Summary We have used a full length cDNA clone to determine the chromosomal location ofthegene encoding human ornithine aminotransferase (OAT), a mitochondrial matrix enzyme. Southern blot analysis of ScaI-digested DNA from 34 human-mouse somatic cell hybrids revealed 11 human fragments. Three fragments mapped to chromosome 10q23-10qter, confirming the previous provisional assignment of the functional gene to this autosome by analysis of OAT expression in somatic cell hybrids (O'Donnell et al. 1985). The remaining eight fragments were assigned to the X chromosome, and regionally assigned to Xp21-Xp11 by use of an X-chromosome mapping panel. These X chromosome sequences could represent pseudogenes, or related members of a multigene family. Two of the X chromosome fragments are alternate alleles of a restriction fragment length polymorphism (RFLP) making this OAT-related locus an excellent genetic marker. The RFLP may now be used to determine any possible relationship between this locus and several X-linked eye defects.     

Serine Hydroxymethyltransferase from Mung Bean (Vigna radiata) Is Not a Pyridoxal-5'-Phosphate-Dependent Enzyme

Serine hydroxymethyltransferase from mammalian and bacterial sources is a pyridoxal-5′-phosphate-containing enzyme, but the requirement of pyridoxal-5′-phosphate for the activity of the enzyme from plant sources is not clear. The specific activity of serine hydroxymethyltransferase isolated from mung bean (Vigna radiata) seedlings in the presence and absence of pyridoxal-5′-phosphate was comparable at every step of the purification procedure. The mung bean enzyme did not show the characteristic visible absorbance spectrum of a pyridoxal-5′-phosphate protein. Unlike the enzymes from sheep, monkey, and human liver, which were converted to the apoenzyme upon treatment with l-cysteine and dialysis, the mung bean enzyme similarly treated was fully active. Additional evidence in support of the suggestion that pyridoxal-5′-phosphate may not be required for the mung bean enzyme was the observation that pencillamine, a well-known inhibitor of pyridoxal-5′-phosphate enzymes, did not perturb the enzyme spectrum or inhibit the activity of mung bean serine hydroxymethyltransferase. The sheep liver enzyme upon interaction with O-amino-d-serine gave a fluorescence spectrum with an emission maximum at 455 nm when excited at 360 nm. A 100-fold higher concentration of mung bean enzyme-O-amino-d-serine complex did not yield a fluorescence spectrum. The following observations suggest that pyridoxal-5′-phosphate normally present as a coenzyme in serine hydroxymethyltransferase was probably replaced in mung bean serine hydroxymethyltransferase by a covalently bound carbonyl group: (a) inhibition by phenylhydrazine and hydroxylamine, which could not be reversed by dialysis and or addition of pyridoxal-5′ phosphate; (b) irreversible inactivation by sodium borohydride; (c) a spectrum characteristic of a phenylhydrazone upon interaction with phenylhydrazine; and (d) the covalent labeling of the enzyme with substrate/product serine and glycine upon reduction with sodium borohydride. These results indicate that in mung bean serine hydroxymethyltransferase, a covalently bound carbonyl group has probably replaced the pyridoxal-5′-phosphate that is present in the mammalian and bacterial enzymes.     

Clarification of yeast by colloidal gas aphrons

Summary Colloidal gas aphrons or CGAs were employed in a flotation column for the recovery of yeast from aqueous solutions. The CGAs sparging rate was a critical factor that governed the efficiency of the process. The separation efficiency was less than 30% at a sparging rate of 1.3 ml sec^–1 and increased exponentially up to 90% as the sparging rate was increased to 2.4 ml sec^–1. Whereas there was no appreciable change in the separation efficiency with CGAs sparging rates for high initial feed concentrations, the maximum achievable efficiency decreased with an increase in the initial feed concentration. In general, a decrease in pH will improve the separation efficiency.