Biomedical subjects

D M Malone

Publications and source records attributed to D M Malone.

10 recordsLinked to original sources

PubMed2000

Effects of hydrodynamic and interfacial forces on plant cell suspension systems.

Plant cells are perceived to be sensitive to the hydrodynamic environment in conventional bioreactors. Heightened sensitivity, relative to most bacterial cultures, is frequently attributed to larger plant cell sizes, extensive vacuolization and aggregation patterns. Early studies of shear sensitivity focused on cell lysis and/or loss of viability. More recently, an extensive array of sub-lethal responses has been identified. A fuller understanding of these sub-lytic effects may assist in the optimization of large-scale cultivation conditions. This paper reviews recent work on the hydrodynamic shear sensitivity of plant cell systems, under cultivation conditions and in purpose-built shearing devices. The relevance of different approaches to the characterization of the intensity of a given hydrodynamic environment is discussed. Indicators of cell response to hydrodynamic stress are evaluated. The potential significance of cellular defense mechanisms, observed in response to mechanical stimulants, is identified.

Bioreactors↗

PubMed2000

Social work early intervention for young children with developmental disabilities.

Social workers' awareness of and formal involvement in family-centered early intervention for infants and toddlers who are at risk of or who have developmental disabilities has increased considerably during the past 15 years. The functional role that social workers can play on early intervention teams and as coordinators of early intervention services is underscored by the formal recognition of the discipline in the Individuals with Disabilities Education Act. Despite the relevance of social work to early intervention, personnel often enter early intervention practice without the benefit of formal preparation related to very young children with developmental disabilities. This article provides an overview of the definition and identification of developmental disabilities, and discusses the role of and challenges to social work in early intervention.

Child, Preschool↗

PubMed2000

Risperidone implicated in the onset of tardive dyskinesia in a young woman.

The aim of this case report is to highlight that risperidone may cause and ameliorate tardive dyskinesia. A 16 year old white women with a 12 month history of schizophrenia, developed buccolingual masticatory tardive dyskinesia after receiving risperidone 6 mg. She had received small dosages of typical antipsychotics before and during receiving risperidone for short periods. Recommencement of risperidone with 2 mg and increasing to 6 mg resulted in improvement in tardive dyskinesia and up until now she remains free of any abnormal involuntary movements.

Adolescent↗

PubMed1997

Plant cell suspension cultures: some engineering considerations.

Higher plants are the source of a vast array of biochemicals which are used as drugs, pesticides, flavourings and fragrances. For some of these compounds, plant cell culture can provide a potential production alternative to traditional cultivation methods or chemical synthesis routes. Many systems have been patented and the last 20 years have seen considerable industrial and academic interest in the development of large scale cultures to produce pharmaceutically active, high value substances. However, the industrial application of plant cell suspension cultures has, to date, been limited. Commercialisation has essentially been impeded by economic feasibility, arising from both biological and engineering considerations. This paper reviews the commercial development of the technology to date and focuses on the impact of specific engineering-related factors, in particular, the shear sensitivity of plant cell suspension cultures. Evidence of sensitivity to hydrodynamic shear in bioreactors has generally been attributed to the physical characteristics of the suspended cells. Recent studies indicate that shear sensitivity may not be as important, in some cases, as initially anticipated.

Bioreactors↗

PubMed1997

A rationale for family therapy specialization in early intervention.

Over the past two decades, professionals providing intervention to families with children with disabilities have witnessed a philosophical shift from individually oriented care to family-centered care. Although the relevance of family therapy to these families has been formally acknowledged through the Individuals with Disabilities Education Act (IDEA), the integration of the fields of family therapy and developmental disabilities has not yet occurred to any significant degree. Awareness of critical issues associated with developmental disabilities and the potential impact on the family system is vital to the process of family-centered intervention. In this paper we address the need for family specialists to become knowledgeable about early intervention considerations relevant to young children with disabilities and their families.

Child↗

PubMed1995

Cell growth patterns in immobilization matrices.

Within an immobilized cell matrix, mass transfer limitations on substrate delivery or product removal can often lead to a wide range of local chemical environments. As immobilized living cell populations actively grow and adapt to their surroundings, these mass transfer effects often lead to strong, time-dependent spatial variations in substrate concentration and biomass densities and growth rates. This review focuses on the methods that have been devised, both experimentally and theoretically, to study the non-uniform growth patterns that arise in the mass transfer limited environment of an immobilization matrix, with particular attention being paid to cell growth in polysaccharide gels.

Journal Article↗

PubMed1991

Ascribed role relations between children with mental retardation and their younger siblings.

Ascribed, parent-mediated childcare roles of younger same-sex siblings of children with mental retardation were compared to roles assumed by a matched group of comparison siblings. Role reversals were evident for younger siblings of children with mental retardation. These reversals were consistent with roles assumed by the siblings during observed interactions. Increased younger sibling childcare roles were related to less conflicted sibling relationships but were not predictive of friendship or socialization experiences of younger siblings. Younger siblings of children with mental retardation had fewer household chores than did comparison agemates. Children with mental retardation had fewer friendship contacts and out-of-home activities than did their peers without mental retardation. Important within-group differences were evident.

Activities of Daily Living↗

PubMed1990

Cognitive play of mentally retarded preschoolers: observations in the home and school.

A within-subjects design was used to examine the cognitive play of 12 mainstreamed mentally retarded preschool boys during group free-play at school and in an independent play situation at home. Children played with available toys at school and with three designated toy sets at home. Cognitive and communicative abilities were established through administration of the Battelle Developmental Inventory. Children not only played more in the home condition, but this play was more sophisticated than that in the school condition. Increased differences between home and school performance were positively associated with expressive communicative developmental age. Peak play did not differ between the two settings. Children not only sequenced play activities more at home, but these sequences were longer and more complex than those at school.

Cerebral Palsy↗

PubMed1974

Mechanism of osmotic flow in porous membranes.

A model for osmotic flow in porous membranes is developed from classical transport and thermodynamic relations. Mathematical expressions for the reflection coefficient as a function of solute dimension and shape, and more generally pore/bulk distribution coefficient, are derived for long cylindrical pores of circular cross section. For a rigid, spherical macromolecule the osmotic reflection coefficient equals (1 - Phi)(2), where Phi is the solute distribution coefficient; this result differs significantly from expressions found in the literature. The effect of weak solute adsorption to (or repulsion from) the pore wall can also be accounted for in the derivation. The driving force for osmotic flow arises from solute-pore wall interactions which cause radial variations in concentration and concomitant gradients in pressure normal to the wall. Implications of this three-dimensionality of osmotic phenomena are discussed with particular reference to the adequacy of one-dimensional treatments in relating reflection coefficient to membrane and solute properties.

Biological Transport↗

PubMedDate not supplied

Effects of sterilization treatments on some properties of alginate solutions and gels.

Aqueous sodium alginate solutions were subjected to various heat sterilization treatments. Sodium alginate powder was also treated by both gamma-irradiation and ethylene oxide sterilization. The effects of these treatments on the viscosities of sodium alginate solutions and both the diameter and strength of the beads formed in 0.1 M CaCl2 solutions were determined quantitatively. The viscosity of sodium alginate solutions and the gel strength of the calcium alginate beads decreased with increasing sterilization temperature while the bead diameters were found to increase. All these effects can be attributable to a reduction in the degree of polymerization of the alginate molecules as a result of the heat treatments. Ethylene oxide and gamma-irradiation treatments caused similar effects. Standard conditions for sterilization are necessary for comparative studies with alginate beads.

Alginates↗