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Biomedical subjects

J E Scott

Publications and source records attributed to J E Scott.

At least 127 records · Page 7Linked to original sources
PubMed1990

Medication compliance and health education among outpatients with chronic mental disorders.

Medication noncompliance occurs among as many as one-third to one-half of all medical and psychiatric outpatients. Noncompliance has serious consequences for individuals diagnosed with schizophrenia, often resulting in higher rates of relapse and rehospitalization, and poorer community adjustment. Health education interventions have been shown to be effective in promoting compliance among patients with chronic medical illness such as hypertension or diabetes, but there have been few randomized trials of this approach among patients with chronic psychiatric disorders. This paper presents the results of an application of health education among a group of male psychiatric outpatients. Two interventions were developed which used health education techniques to 1) engage families or significant others as active participants in the aftercare process, and 2) train patients to become effective health care consumers. A total of 418 individuals participated in a six-month trial over a four-year study. Both interventions significantly improved medication compliance among those who received them. The results show that comparatively brief interventions can significantly alter medication compliance behavior and improve the quality of life for patients with chronic psychiatric disorders.

Attitude to Health↗
PubMed1990

Ultrasound measurement of renal size in newborn infants.

Renal measurements were made by ultrasonography in 560 healthy newborn infants. Three dependent variables (kidney length, kidney depth, and kidney area) were measured, together with three independent variables (birth weight, head circumference, and gestational age). The SD of the measurement inconsistency was 0.13 cm for length, 0.078 cm for depth, and 0.32 cm2 for area; the percentages of total variance caused by measurement inconsistency were 7.9, 9.5, and 7.5, respectively. There was a significant difference between right and left kidneys in length and depth for each independent variable. The left kidney increased more in length and less in depth than the right so that the areas remained similar as the scale of variable increased. Kidney depth and area in boys were significantly larger than in girls, both dimensions increasing at equal rates. Centile charts for each dependent variable by each independent variable were constructed by a non-parametric method.

Birth Weight↗
PubMed1990

The comparative chemical morphology of the mammalian cornea.

A simple model of mammalian corneal stroma has been tested against biochemical and ultrastructural measurements performed on a number of species. Contents of water, collagen and total sulphated polyanion were constant, as predicted from the model. Alcian blue CEC results showed great variability between species, with a rise in CEC as corneal size and thickness increased. These variations were due to changes in keratan sulphate content, and particularly to its oversulphated terminal domain, which is absent from mouse cornea. The increase in keratan sulphate content with corneal thickness was balanced by an increase in dermatan sulphate in thin corneas, thus maintaining total sulphated GAG levels at a constant "average", in all the mammals investigated. This balance is probably decided by oxygen tension, which will vary with corneal thickness.

Animals↗
PubMed1990

Proteoglycan:collagen interactions and subfibrillar structure in collagen fibrils. Implications in the development and ageing of connective tissues.

Evidence is presented confirming that collagen fibrils are aggregates of subfibrils. Rat tail tendon fibrils swollen in acetate buffer, pH 5.8, (with or without MgCl2 or Cupromeronic blue, a proteoglycan (PG) precipitant used to locate PGs by electron histochemistry) showed two characteristic populations of subfibrils, of 10-15 nm, and approximately 25 nm thickness respectively. The smaller protofibrils, helically orientated, were derived from, or coalesced into, the larger subfibrils. The results prove that cross-links are not regularly distributed throughout the tissue but are limited to intra-protofibrillar collagen. Cupromeronic blue-stained PGs were seen in thick fibrils from cartilage and tendons, axially orientated in bands across the fibrils in longitudinal sections, or chordally in fibril cross-sections. Based on the intrafibrillar location of PGs vis-à-vis the fibril a-e banding pattern, the relative orientation of PGs and protofibrils and PG distribution in very young, as compared with mature or old, tissue, it is suggested that intrafibrillar PG is originally associated with protofibrils, which coalesce to larger fibrils, e.g. during development. The function of the large amount of PG and hyaluronan in young tissues is seen to keep the collagen protofibrils and subfibrils from coalescing. Disaggregation to protofibrils was demonstrated in conditions not very different from certain in vivo situations. It is suggested that this phenomenon is potentially important during tissue modelling and remodelling, allowing rapid access of reactants to the interior of thick fibrils and recycling of component protofibrils.

Aging↗
PubMed1989

Secondary structures in hyaluronan solutions: chemical and biological implications.

Hyaluronan behaves as an unusually stiff polymer in solution. Periodate oxidation of the hexuronic acid moiety is severely hindered, as is that of chondroitin 4-sulphates and 6-sulphates. On the basis of X-ray and computer studies a secondary structure was proposed which accounted for the known facts. NMR data obtained subsequently in dimethyl sulphoxide were completely compatible with these proposals. Results obtained in H2O suggested that the acetamido group could not be oriented in aqueous solution as it was in dimethyl sulphoxide solution. There is strong evidence that an H2O bridge between the acetamido and carboxylate groups is involved in the secondary structure in H2O. It is suggested that conversion of one structure (stable in the absence of H2O) to the other (in aqueous solution) might occur during biosynthesis, as part of the driving force that results in shedding from the H2O-poor environment of the membrane. The hydrogen-bonded secondary structures show quite large arrays of contiguous CH groups, giving a hydrophobic character to some parts of the polymer, which might be significant in self-association and for interactions with membranes.

Carbohydrate Conformation↗
PubMed1989

Proteoglycan: collagen interactions in dermatosparactic skin and tendon. An electron histochemical study using cupromeronic blue in a critical electrolyte concentration method.

Proteoglycans (PGs), stained for electron microscopy with Cupromeronic blue, were observed in skin and tendon from normal and dermatosparactic calves. Very frequently they (i.e. dermatan sulphate (DS) PGs) were seen arrayed orthogonally to the collagen fibrils, in the gap zone, usually at the d band, in both diseased and normal tissues. Where UO2(2+) staining showed regular and normal packing of collagen molecules, orthogonally located DS PGs were seen. No qualitative differences between controls and pathological tissues were identified, but quantitatively it appears likely that considerable areas of the surface of dermatosparactic skin collagen fibrils may be without associated PGs.

Animals↗
PubMed1989

Intermittent catheterisation for neuropathic urinary incontinence.

Eighty six children with neuropathic urinary incontinence who had been treated by clean intermittent catheterisation for more than five years were reviewed. Eighty five had congenital lesions, and one traumatic paraplegia. During the day, 72 (84%) patients were dry or had minor stress incontinence only, 11 were damp but controlled with pads, and only three were continuously wet. Eleven abandoned clean intermittent catheterisation, five because of poor control, four by choice despite good control, and only two because of deterioration of upper urinary tract disease. Most of them usually had bacteriuria, but only 32 developed occasional symptomatic infections. Urinary calculi occurred in six, epididymitis in three, and urethral problems in four. Upper urinary tract dilatation did not arise in a previously normal renal system in any patient during clean intermittent catheterisation. Clean intermittent catheterisation was successful in controlling wetting with few serious complications, and was well tolerated. It remains the method of choice for the management of neuropathic urinary incontinence in such children.

Adolescent↗
PubMed1989

Keratan sulphate: a functional substitute for chondroitin sulphate in O2 deficient tissues?

Keratan sulphate and chondroitin sulphate can each fill space and exert swelling pressure in collagenous fibrillar matrices, but whereas the former is synthesised from glucose precursor without consuming NAD, the latter converts 2 mols of NAD for each uronate residue in the polymer chain. We suggest that the observed distribution of keratan sulphate and chondroitin sulphate in cartilage, cornea and intervertebral disc are determined by the ambient oxygen tension, and that keratan sulphate is preferentially synthesised in conditions of oxygen lack. The implications of this hypothesis in the physiology of contact lenses, cartilage degeneration, corneal scar repair and ageing are discussed.

Aging↗
PubMed1989

Ion binding: patterns of 'affinity' depending on types of acid groups.

Bungenberg de Jong's sequences of cation binding to polymer-bound anionic sites established, over 40 years ago, that the most common cations, Na+, K+, Mg+(+) and Ca+(+), in biological materials behaved differently in the presence of the three most common polyanionic charges, carboxylate, diester phosphate and ester sulphate. He proposed a fundamental mechanism involving polarisability and polarising power, respectively, of the anionic electrons and the cation, which accounted for his observations. We generalised his mechanism to provide a relationship between the pK of the anion and the ion binding spectrum. Extracellular polyanions would be predicted to prefer K+ to Na+, in spite of the preponderance of Na+ in the extracellular space. It is suggested that this preference was important during biosynthesis inside the cell, where K+ is predominant.

Acids↗
PubMed1989

In praise of dyestuff histochemistry.

The merits of low molecular weight reagents (mini-stains) for localising tissue components, are compared with those of high molecular weight (macro-stains), with respect to stoichiometry, ease of tissue penetration, and particularly specificity. Macro-stains, which are based mainly on antibodies, are likely to be more specific, but this will not always be the case. The concept of specificity in the design of mini-stains is examined, and its application to the delivery of e.g. Cupromeronic blue to particular substrates in the "critical electrolyte concentration" system, is discussed. The much greater resolving power of mini-stains in electron histochemistry has permitted the elucidation of four specific binding sites for proteoglycans along the collagen fibrils, validating the 'one proteoglycan: one binding site' hypothesis.

Animals↗
PubMed1988

A water molecule participates in the secondary structure of hyaluronan.

The structure of hyaluronan was investigated in water/dimethyl sulphoxide mixtures by using high-field n.m.r. and space-filling molecular models. The secondary structure previously established in detail in 'dry' dimethyl sulphoxide [Heatley, Scott & Hull (1984) Biochem. J. 220, 197-205] undergoes changes on addition of water, compatible with the incorporation of a water bridge between the uronate carboxylate and acetamido NH groups. Molecular models show that such a configuration is highly probable, and saturation-transfer experiments yield rates of NH proton exchange that support this proposed structure. The existence of two distinct stable configurations for hyaluronan, in water-rich and water-poor conditions respectively, may have biological implications, e.g. during its biosynthesis in cell membranes. There are extensive hydrophobic regions in both forms, which may be important for interactions with e.g., membranes, proteins and itself.

Dimethyl Sulfoxide↗
PubMed1988

Identification of specific binding sites for keratan sulphate proteoglycans and chondroitin-dermatan sulphate proteoglycans on collagen fibrils in cornea by the use of cupromeronic blue in 'critical-electrolyte-concentration' techniques.

Proteoglycans (PGs) in bovine corneal stroma were stained with Cupromeronic Blue in 'critical-electrolyte-concentration' (CEC) methods for electron microscopy, and were located vis-à-vis collagen fibril a-e banding patterns. Keratanase and chondroitin ABC lyase digestion showed that a + c-band- and d + e-band-associated PGs were keratan sulphate-rich and chondroitin (dermatan) sulphate-rich respectively. The CEC pattern proved that the keratan sulphate PGs at the a and c bands differed. Comparison of their CECs with their behaviour on anion-exchange chromatography confirmed previous (indirect) attempts at identification [Scott & Haigh (1985) Biosci. Rep. 5, 765-774]. Similar arguments were applied to the dermatan sulphate PGs at the d and e bands. These results strongly support the one-PG-one-binding-site hypothesis [e.g. Scott (1988) Biochem. J. 252, 313-323]. Remarkable inter-species variations in the keratan sulphate PG patterns contrast with the relatively constant picture of dermatan sulphate PG-collagen fibril interactions.

Animals↗