Quantification of cerebrospinal fluid proteins in children by high-resolution agarose gel electrophoresis

Physiologic alterations in cerebrospinal fluid proteins occur inter alia with aging. Agarose gel electrophoresis discriminates many cerebrospinal fluid proteins and in addition quantifies concentration alterations. This study aimed to investigate the time course of these alterations in children and to establish normative values for cerebrospinal fluid protein properties. In 202 children without diseases known to alter cerebrospinal fluid, normative protein properties were quantified using nephelometry, ultrafiltration, high-resolution electrophoresis, and Gaussian curve fit densitometry. Total protein and protein concentrations (albumin and gamma-globulins) decreased from birth until 7 months age, and, from then on, increased slightly (transthyretin, albumin, and alpha2-proteins) or strongly (gamma-globulins). Protein proportions (transthyretin and transferrin) increased until about 3 years of age and decreased from then on. These normative values for children as quantified by high-resolution agarose gel electrophoresis are presented in a significance-structured percentile table. The time courses of these cerebrospinal fluid properties reflect physiologic alterations of the blood-brain barrier function during childhood.

An acute cerebellar syndrome following high-dose chemotherapy and a blood cell autotransplant

A woman with high-risk stage III breast cancer developed acute cerebellar syndrome 75 days after high-dose chemotherapy and blood cell transplant (BCT). An extensive search for metastatic, vascular, metabolic, infectious, and paraneoplastic etiologies was negative. We postulate a delayed adverse effect of high-dose chemotherapy as the etiology.

Satisfaction with a new model of professional practice in critical care

Although only a moderately severe general nursing shortage exists at this time, the shortage of critical care nurses remains severe. Innovative administrators across the country are trying new professional practice models aimed at maximizing autonomy and freeing nurses from mundane tasks with the hopes of retaining experienced clinicians. We implemented a professional practice model in which unlicensed assistive personnel were trained to assist registered nurses in patient care. Monies saved by increasing nurse-patient ratios were distributed to staff nurses. Acuity-based staffing was maintained and professional practice encouraged through self-scheduling and elimination of hierarchical relationships. Satisfaction among nurses working in the program increased in terms of coworkers and supervision. Patient satisfaction with the quality of care provided did not change during the course of the program. Data from interviews demonstrated that staff were satisfied with the quality of care provided by the assistants, but the changes in the staffing ratios coupled with the increased responsibility for overseeing the assistants caused stress in the nurses. We conclude that a professional practice model in which critical care assistants are added to the work force is a viable option, but creative methods of addressing the stress of increased workload are needed.

Preterm infant follow-up project: a multi-site field experiment of hospital and home intervention programs for mothers and preterm infants

This study was designed as a multi-site field experiment to test the efficacy of hospital and home visit interventions to improve interaction between mothers and preterm infants. Hospital intervention consisted of State Modulation (SM) treatment, which focused on teaching mothers to read the behavioral cues and modulate the states of consciousness of preterm infants during feedings. Home visit intervention was a field-tested program, Nursing Systems for Effective Parenting-Preterm (NSTEP-P), implemented during the first five months after the infant's hospital discharge. A hospital program on car seats (CS) and standard public health nursing home visits (PHN) served as comparison treatments. The sample consisted of 327 mothers and their preterm infants who were less than 36 weeks of gestational age at hospital discharge. Mothers were randomly assigned to intervention groups on the basis of their education. High education (HE) was > or = 13 years of education, while low education (LE) was < or = 12 years of education. HE mothers were only assigned to hospital programs, while LE mothers were assigned to combinations of hospital and home visit programs. Evaluations were conducted at 40 weeks conceptual age (expected date of birth), at 46 weeks conceptual age (1.5-months-corrected age), and 60 weeks conceptual age (5-months-corrected age). Comparisons were made within each educational group. For HE groups, SM infants gave significantly more clear cues during observations of feeding interactions at 1.5-months-corrected age and teaching interactions at 5-months-corrected age than infants in the CS group. During the teaching interaction, well-educated SM mothers provided significantly more social-emotional and cognitive stimulation than CS mothers. For LE groups, infants in the SM group combined with either PHN or NSTEP-P exhibited significantly more responsive behavior during feeding observations than those infants in the CS/PHN group at 1.5-months-corrected age. LE mothers in the SM/NSTEP-P group demonstrated more sensitivity and more stimulation during teaching interactions at 5-months-corrected age than mothers in the SM/PHN or CS/PHN groups. Findings suggest that State Modulation treatment is effective in influencing positive social interaction of infants regardless of the level of maternal education. State modulation treatment combined with NSTEP-P is most effective in improving the social interaction between preterm infants and mothers with limited formal education. Such treatment-specific programs suggest avenues for providing cost-effective care that complements the changing transactional needs of mothers and preterm infants.

Description of the clinical practice of advanced practice nurses in family-centered early intervention in two rural settings

The purpose of this study was to describe the scope of clinical practice of advanced practice nurses who were involved in a project designed to increase access of families with at-risk and disabled young children, newborn to 3 years of age, to early intervention services in rural Washington State. The findings from this study are based on the retrospective review of records of clients seen by the advanced practice nurses. Nursing diagnoses and nursing interventions were assigned to chart recordings. The most frequently occurring nursing diagnoses assigned to parents were Altered Parenting, Altered Family Processes, Fear, Noncompliance, and Knowledge Deficit. The most frequently occurring nursing diagnoses assigned to children were Impaired Physical Mobility, Impaired Verban Communication, Altered Nutrition: Less than Body Requirements, Sensory-Perceptual Alteration, and Altered Thought Processes. Categories of nursing intervention recorded most frequently were Monitoring, Planning and Information. Discussion of findings addresses the roles and reimbursement of advanced practice nurses who provide family-centered early intervention services in rural communities.

Elongational flow studies on type IV collagen: comparison with type I

Elongation flow techniques have been used to investigate the birefringent response of monodisperse type IV collagen in dilute solution and the results compared with type I collagen. A four-roll mill apparatus was used to characterize the solutions at low strain rates, epsilon < or = 300 s-1. The birefringence is nonlocalized and rises gradually to a plateau value, in accordance with rigid-rod behavior. The gradients of the tangent to the curves at zero strain rate are estimated for types IV and I collagen. The concentrations of the solutions used were in the dilute to semidilute regimes. Using a value of 300 nm for the length of type I collagen, values of 364-408 nm were calculated for the length of the type IV collagen molecule, depending on the concentration regime chosen, which is consistent with biochemical predictions based on a rigid molecule. The results imply that the behavior of type IV collagen molecules in solution is similar to type I collagen, despite the presence of several sequence interruptions in the type IV helix.

Molecular bending and networks in a basement membrane-like collagen: packing in dogfish egg capsule collagen

Low-angle X-ray diffraction data have been obtained from three mutually perpendicular axes through sheets of the collagenous egg capsule of the dogfish Scyliorhinus caniculus, a collagen that resembles type IV collagen. The data are interpreted in the light of the body of knowledge of the structure derived from transmission electron microscopy by Knight and Hunt. A model to account for the X-ray data is proposed incorporating the main dimensions of the Knight and Hunt model which are confirmed by the diffraction data. Several features of the diffraction patterns are not explained by the existing model however, and a new model is proposed to account for these features. This consists of antiparallel packed pairs of two mutually parallel molecules, each kinked and rotated so as to produce a four-fold helix resembling a crankshaft. This has the advantage of conferring intermolecular linkage in three dimensions throughout the structure with tetragonal symmetry and unit dimensions a = b = 22.6 nm, c (fibre axis direction) = 39.3 nm. The result is a fairly rigid open polygonal network or sponge-like architecture that is capable of accommodating large quantities of water and other molecules.

Learning and behavioral--emotional problems of children born preterm at second grade

A longitudinal prospective study examined the question, "which child and family factors discriminate between children born preterm who are characterized by the presence or absence of learning or behavioral-emotional problems at second grade?" Assessments were completed during the child's hospital stay at birth, at 4, 8, and 24 months, and 8 years of age for 68 children born preterm and their mothers. Discriminant analyses identified the variables that statistically maximized the differentiation between two groups of children defined to exhibit or not exhibit school age problems. Three categories of discriminators were used in the analyses: infant status, family interactive quality, and family context. The three significant discriminators were variables from the family categories. The results of this study highlight the importance of understanding the presence or absence of school age problems from a multivariate model of development that takes into account the quality of the child's interactions within the family during early childhood and school age and the current stress levels in the family context.

Three-dimensional structure of type IV collagen in the mammalian lens capsule

The anterior lens capsule provides a thick, easily handled model system for the study of the organization of type IV collagen, the main component of basement membranes. We have used the technique of rapid freezing, deep-etch, and rotary replication to study the three-dimensional organization of the collagen skeleton in mammalian lens capsule after a variety of extraction procedures. In all cases the collagen appeared as a densely packed three-dimensional branching network of fine microfibrils. The organization of the microfibrils appears to show some regularity, with branch points approximately 40 nm apart. Most junctions are three-way and the network forms predominantly five-sided figures. This closely resembles the collagenous network described by Yurchenco and Ruben (1987, 1988) in human amniotic basement membrane and EHS tumor matrix, but extends their findings to another system for which X-ray diffraction data are available. The three-dimensional network is discussed in terms of molecular packing of type IV collagen in light of the information available from the diffraction data.

Short and long range order in basement membrane type IV collagen revealed by enzymic and chemical extraction

Oriented bovine lens capsules give X-ray diffraction patterns suggesting a considerable degree of order in the collagenous components, predominantly type IV collagen. Here we report the effects of preliminary treatment of lens capsules before orientation. Extraction with 4 M guanidinium hydrochloride or with heparinase/hyaluronidase reveals the same collagenous diffraction patterns previously seen after extraction with 1 M NaCl. There is a four-point pattern of d-spacing 3.9 nm, indicating liquid crystal cybotactic nematic organization, along with sharp streaked meridional reflections which index as orders of 21 nm. This suggests that the removal of basement membrane proteoglycans results in a reduction in diffuse scatter and clarification of the pattern. Extraction of the lens capsules with trypsin or dithiothreitol greatly reduces the intensity of the four-point pattern while leaving the meridional pattern unaffected. This strengthens the evidence that the 21 nm period has its origins in the collagen IV helix. Reduction in the four-point pattern could arise if disruption of non-helical NC1 domains or 7S overlap regions allows slippage of the collagen molecules on orientation, weakening the proposed 1 nm intermolecular stagger. Ultra-low angle diffraction patterns of extracted lens capsules show meridional reflections which index as a long-range axial repeat of approximately 95 nm. This is consistent with a model of microfibrils of type IV collagen in which the NC1 domains bind to the collagen helix at approximately 100 nm intervals, as has been previously suggested.

Molecular organization of type IV collagen: polymer liquid crystal-like aspects

A new X-ray diffraction pattern from type IV collagen is described, which can be interpreted on the basis of crystalline and liquid crystalline origins of the reflections. Bovine anterior lens capsules extracted with 1 M NaCl and oriented by extension of 60% under constant load gave medium angle X-ray diffraction patterns showing many of the characteristics typical of liquid crystals. Prominent features, apart from those wide angle features attributable to the collagen triple helix, are (1) a four-point pattern of broad reflections at d-spacing 3.9 nm, and layer line spacing near 5 nm. (2) A broad intense equatorial peak centred at 1.24 nm, indicative of liquid-like lateral molecular associations. (3) A set of five sharp, streaked meridional reflections (previously obscured by the broad peak near 5 nm in unextracted capsules). (4) A further six higher angle reflections of a diffuse, arced and broad appearance on the meridian. The sharp streaked meridional reflections emanate from a long-range periodicity of units 8-9 nm in diameter. These features form a self-consistent system if interpreted on the basis of a staggered liquid crystal-like array of collagen molecules, in which case the first five meridionals and remaining broad reflections, sampled on the meridian, can all be indexed as orders of 21 nm.

Chemistry of the collagen cross-links. Origin and partial characterization of a putative mature cross-link of collagen

The conversion of the reducible divalent cross-links in collagen to non-reducible multivalent cross-links in mature collagen has resulted in the identification of several new amino acids as the putative mature cross-link. None of these compounds has completely satisfied the necessary criteria. We have now isolated an amino acid of high Mr, derived from lysine, that is only present in high-Mr peptides derived from mature collagen. Its increase with age of the tissue correlates with the decrease in the reducible cross-links, and it is present both in mature skin and bone, which are initially cross-linked through the aldimine and oxo-imine divalent cross-link respectively. We propose that this amino acid, as yet incompletely characterized and designated compound M, is a major cross-link of mature collagen.

Basement membrane collagen--evidence for a novel molecular packing

Type IV collagen is the major structural protein of basement membranes but very little is known about its molecular organisation in vivo. We have used X-ray diffraction of a thick basement membrane, bovine lens capsule, to provide information. Under constant load, lens capsule gave a collagen diffraction pattern of a similar quality to unstretched rat rail tendon. In addition there were clear meridional reflections which indexed as orders of 10 nm, and equatorial reflections at 2.1 and 3.8 nm. These results suggest the ordering of type IV collagen molecules in fibrils, with a 10 nm periodicity along the length of the fibrils.

Labour relations in health services management

'Labour relations' or 'industrial relations' refers to employer-employee relations which are both economic as in matters of pay and conditions, and managerial, i.e. the political relationships between management and employees, collectivized through trade unions and professional associations. This paper traces the development of managerial relationships as illustrated by experiences in the British National Health Service particularly over the past 20 years focusing on groups of actors--management (within which may be distinguished government and local managers), health professional workers and other workers--whose interactions need to be studied if managerial relations within health services are to be satisfactorily analysed. We conclude that, although until recently, developments in management have had little impact upon worker behaviour outside unskilled groups, changing economic and other circumstances could create the conditions in which stronger managerial control over professional workers might emerge.

Measurement of anti-glomerular-basement-membrane antibodies by micro ELISA using insoluble antigens

An enzyme immunoassay, using finely ground rabbit glomerular basement membrane (GBM) as an antigen, was able to detect sheep anti-rabbit GBM antibodies at serum dilutions of 1:32 000. The particulate GBM bound firmly to plastic micro ELISA plates without the aid of a linking agent, and the antigen-coated plates remained stable for several months when stored at -70 degrees C. There were no appreciable differences between amino acid compositions of ground and whole GBM, and no detectable loss of antigens occurred during the grinding procedure. Competitive inhibition assays with collagenase and pepsin digests of rabbit GBM demonstrated preservation of collagenous and non-collagenous antigens in the ground GBM. The assay should prove to be a relatively simple and highly sensitive technique for detecting antibodies to a wide spectrum of GBM antigens.

Lysozyme is a component of human vascular elastic fibers

Lysozyme has been demonstrated in the elastic fibers of normal human arteries and veins by the peroxidase-antiperoxidase technique. Preliminary trypsinization of paraffin sections is necessary to unmask the immunoreactive lysozyme.