Search PubMed⌕ Search

Biomedical subjects

R Collins

Publications and source records attributed to R Collins.

At least 217 records · Page 12Linked to original sources
PubMed1985

Effect of maternal education on prognosis of development in children with Down syndrome.

Longitudinal development data from 40 home-reared children with Down syndrome who had been enrolled in an infant stimulation program were analyzed by level of maternal education: high, medium, or low. High level of maternal education was significantly correlated with higher mental development scores (P less than .001) and significantly different from scores of those with medium and low maternal educational level (P less than .001). The differences between groups with medium and low maternal education showed the same trend but were not significant. Multiple regression analysis confirmed that these differences were consistently significant throughout the age range. Analysis of longitudinal data of a subgroup of 11 children with Down syndrome showed remarkable intrasubject consistency and intersubject variability. This suggests that the intellectual functioning of the population with Down syndrome is not a uniform one but is subject to the same genetic and environmental influences as the rest of the population. The creation of percentile charts is advocated for the evaluation of treatment programs.

Adult↗
PubMed1984

An effective therapeutic intervention with adolescent in-patients in love.

Easson noted in 1967 how little had been published on intimate (frequently sexual) involvements between adolescents in in-patient settings and remarked how staff attitudes and countertransference feelings frequently resulted in an unsatisfactory resolution of such occurrences. Since that time the literature has remained sparse, yet the phenomenon and the problem of how best to deal with it persists. The present case study of two female in-patients "in love" attempts to demonstrate the usefulness of a simple and presumably infrequently used mode of intervention in promoting therapeutic growth and facilitating ward management. Rather than attempting to separate the two patients and deal with issues of their relationship individually, the existence of the relationship was acknowledged and accepted, and conjoint meetings which explored its troublesome aspects were held with them and their respective therapists. Provocative behaviour on the ward diminished, some insights were gained and their separation due to the discharge of one of them was effected with minimum turmoil. While certain factors specific to the case may have contributed to the outcome, the success of the intervention, nonetheless, warrants further application and study in the clinical arena.

Adolescent↗
PubMed1984

Monoclonal antibodies against antigens of the human platelet surface: preparation and properties.

Three monoclonal antibodies, FMC24, 25 and 27, reactive with human platelets, are described. In normal blood the 3 antibodies are specific for platelets, but FMC27 reacts with leukemic blast cells in a proportion of acute leukemias. FMC25 precipitates the platelet membrane glycoprotein lb and a glycoprotein of molecular weight 22,000. The antibodies show different effects on platelet aggregation.

Acute Disease↗
PubMed1984

A theoretical model for myocardial tissue deformability.

Early detection of cardiac disease is based on the quantitative interpretation of left ventricular wall motion throughout the cardiac pumping cycle. Wall deformations result from complex fluid-wall interactions wherein muscle fibre orientation, intraventricular pressure and regional variations of myocardial wall rheology play a crucial role. A reliable theoretical model would be of intrinsic value in aiding the cardiologist in his interpretation of clinical diagnostic results, particularly through the incorporation of microprocessor-based algorithms permitting automatic processing of clinical data within the framework of such a model. As a step in this direction, a theoretical analysis is formulated for a relatively simple characterization of the left ventricle in terms of a truncated ellipsoidal shell. The myocardial wall contains contractile muscle fibres of known orientation. The stress tensor is derived on the basis of an inviscid fluid-fibre continuum. Principal stresses are calculated in terms of regional wall deformations and intraventricular pressure. These are determined from an inviscid fluid dynamic model for left ventricular contraction, subject to an appropriate Neumann condition on wall velocity as obtained from cineangiography. Local "defects" in wall velocity simulate the inhibition of wall contractility associated with the development of myocardial infarct. The theoretical model makes it possible to evaluate local variations in wall stress at those sites and to calculate both regional and overall changes in heart work as a noninvasive indicator of cardiomyopathies or valvular defects. Graphic results are presented depicting the role of myocardial tissue rheology on the dynamics of cardiac performance during the ejection phase, on the basis of the present theoretical model.

Blood Pressure↗
PubMed1984

Further studies on human plasma aldosterone-binding globulins: isolation, purification, and evidence for heterogeneity.

The present study further characterizes the aldosterone-binding globulin (ABG) in human plasma. Isolations were performed by ultrafiltration, Blue Sepharose CL-6B, or ion-exchange chromatography and gel filtration. New ABG species were identified: interconvertible with ABG in plasma is a thermolabile (MW less than 70,000) and a thermostable ABG macromolecule (MW 27,500). All forms were extensively purified to electrophoretic homogeneity (SDS-PAGE) showing microheterogeneity in isoelectric focusing (pI 4.76 and 4.8) and reversible high-affinity binding for aldosterone. Chromatography of lipoprotein-free plasma in DEAE-Sephadex A-50 gel (ionic gradient) revealed the presence of a dimer of ABG (MW 55,000) which was found to be interconvertible with ABG and was the main carrier of aldosterone in normal fresh plasma. Selective adsorption of albumin from lipoprotein-free plasma on Blue Sepharose CL-6B permitted in a single novel step the complete resolution of bound aldosterone (binding ABG) and bound cortisol (binding corticosteroid-binding globulin). Both ABG and the dimer can be separated from corticosteroid-binding globulin by Blue Sepharose chromatography. A new homeostatic mechanism in which ABG participates in blood pressure regulation by interacting with aldosterone is postulated.

Aldosterone↗
PubMed1982

Combined neutrophil and T-cell deficiency: initial report of a kindred with features of the hyper-IgE syndrome and chronic granulomatous disease.

A six year old female presented with a recent history of pyoderma gangrenosum involving her legs and arms associated with an episode of Mycoplasma-like pneumonia. This was followed by Aspergillus osteomyelitis involving her left ulna and right femur. Both the skin lesions and the osteomyelitis responded to prolonged treatment with antifungal and antibiotic agents. Investigation of this patient revealed (1) an elevated serum IgE (4,800 units/ml), (2) defect in neutrophil chemotaxis that appeared to be due to immune complexes, (3) an abnormal nitroblue tetrazolium (NBT) result (0 percent stimulated and unstimulated), and (4) depressed mitogen responses to concanavalin A, phytohemagglutinin, and pokeweed mitogen, negative results of intradermal skin tests, and negative dinitrochlorobenzene (DNCB) sensitization. The patient's clinically unaffected sibling had similar findings except for a positive DNCB response. In both children, intracellular bacterial killing of catalase-positive and negative organisms was normal. Kindred studies revealed widespread T-cell abnormalities consistent with autosomal dominant inheritance. Tissue typing studies showed that affected siblings shared the A1, B8, DR3 haplotype. This kindred is unique in that both the proband and the sibling have abnormalities of both the hyper-IgE syndrome and chronic granulomatous disease.

Child↗
PubMed1981

Documentation of Epstein-Barr virus infection in immunodeficient patients with life-threatening lymphoproliferative diseases by clinical, virological, and immunopathological studies.

Multiple methods, pedigree analysis, clinical evaluation, and Epstein-Barr virus (EBV)-specific serology, EBV DNA hybridization of tissues to probe for viral genome, staining of touch imprints for EBV nuclear-associated antigen, establishment of spontaneous infected B-cell lines from peripheral blood or tissues, examination of peripheral blood smears, and hematopathology studies, were used to study seven patients with the X-linked lymphoproliferative syndrome and seven additional patients with life-threatening EBV-associated diseases. These studies demonstrated EBV in the tissues of all 14 patients and immunodeficient antibody responses to EBV were documented. This virus can produce various life-threatening lymphoproliferative diseases in a variety of immunodeficient patients.

Adolescent↗
PubMed1981

Documentation of Epstein-Barr virus infection in immunodeficient patients with life-threatening lymphoproliferative diseases by Epstein-Barr virus complementary RNA/DNA and viral DNA/DNA hybridization.

Tissues from patients thought to have Epstein-Barr virus (EBV)-induced lymphoproliferative diseases were probed for EBV genomes using 2 independent hybridization techniques. Tissues from six patients with the X-linked lymphoproliferative syndrome, all five renal allograft recipients with immunoblastic sarcoma, and eight patients with diverse types of immunodeficiency and lymphoproliferative diseases such as fatal infectious mononucleosis or malignant lymphoma associated with antecedent immunodeficiency contained significant numbers of EBV genome equivalents per cell. The use of 2 hybridization probes is recommended to confirm the presence of EBV genomes. The finding of significant numbers of EBV genomes in tissues from patients with immunodeficiency suggests that EBV is the etiological agent of the associated lymphoproliferative diseases.

Adolescent↗
PubMed1981

Onchocerciasis in Guatemala. Epidemiology in fincas with various intensities of infection.

To provide quantitative information on the epidemiology of infection with Onchocerca volvulus and to define the association between indicators of infection and onchocercal eye disease, skin snips were obtained and skin and ocular examinations were performed on 892 persons living on seven Guatemalan coffee plantations. Skin-snip positivity and the density of microfilariae in the skin increased with age, reaching highest levels at 15-19 years, and both were greater in males than females. A history of nodulectomy was given by 67% of long-term residents and this percentage also increased with age. Over 90% of skin-snip positive subjects and 39% of skin-snip negative subjects had previous or present nodules. Microfilariae were detected in the cornea of 35.1% and in the anterior chamber of 18.9% of all persons examined and the frequencies increased with age, reaching peak levels at 10-19 years. Onchocercal eye lesions were found in 52 persons, causing bilateral blindness in six. Skin-snip positivity, microfilarial skin density, number of nodules, eye infection, and onchocercal eye lesions all correlated significantly with each other. Onchocercal blindness in one or both eyes was found only on fincas with a high prevalence (greater than 80%) and intensity of infection (greater than 22 microfilariae/mg skin).

Adolescent↗
PubMed1980

The effects of ethanol on developing catecholamine neurons.

Significantly lower concentrations of norepinephrine were observed in whole brain and hypothalamus of pups exposed to ethanol pre- and post-natally as compared to controls. Dopamine levels were found to be unaltered in whole brain compared to controls although hypothalamus and corpus striatum demonstrated a decreased concentration in the experimental animals exposed to ethanol. The reduced levels of these neurotransmitters observed in the hypothalamus could reflect a direct damage to norepinephrine neurons by pre- or post-natal exposure to ethanol. However, depressed dopamine levels in the corpus striatum indicate additional injury to dopamine neurons. Alternatively, a modulatory interaction between norepinephrinergic and dopaminergic systems may be operative in these offspring. The changes observed in catecholamines could not be explained by a single and simple mode of ethanol action in the developing rat.

Aging↗
PubMed1978

SOluble and insoluble immune complex-platelet interactions in rheumatoid inflammation.

The interactions of soluble and insoluble immunoglobulin G (IgG) complexes with macromolecular rheumatoid factor (RF) and platelets were examined in an in vitro system permitting observation of platelet activities which may contribute to rheumatoid inflammation. Studies of the aggregation phenomenon by the nephalometric technique and by selective sedimentation of 51Cr-labelled platelets revealed no aggregation by platelets exposed to heat aggregated IgG (HAIgG) complexes or their RF precipitates in a plasma test system. Release of serotonin was demonstrated by the increasing radioactivity of platelet supernates to 45 min by 14C-serotonin labelled platelets exposed to insoluble IgG heat aggregates. Significantly less release was shown with saline, native IgG, and soluble IgG complexes. When RF was added to soluble HAIgG complexes, the resulting precipitate caused significantly higher release than controls. No concomitant release of the lysosomal enzyme beta-glucuronidase was detected. Thus, although soluble complexes do not cause significant release of biologically active amines, conversion of soluble complexes to insoluble immune precipitates by RF is associated with this activity which is independent of platelet aggregation and/or lyosomal enzyme release in our test system. Release of biologically active amines from platelets exposed to insoluble complexes may be important in the initiation and propagation of inflammation in rheumatoid arthritis.

Antigen-Antibody Complex↗