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Biomedical subjects

M Roberts

Publications and source records attributed to M Roberts.

At least 361 records · Page 20Linked to original sources
PubMed1978

Continuous tracking of behavioral development in infants.

Infant development scales provide a one time measure of the number of scale items an infant performs and his standing relative to his age group. Repeated assessment indicates how many more items he can perform and whether his relative status has altered but does not measure actual changes in the same behaviors as development progresses. This paper discusses the importance of continuously measuring the same behavior over time as an alternative strategy. The developmental information is exemplified by the behavioral records of two infants observed over a 25-week period for changes in frequency and duration of three prone position motor responses.

Child Behavior↗
PubMed1978

Development of a sorbent peritoneal dialysate regeneration system--a progress report.

A sorbent regenerative dialysate system for peritoneal dialysis has been developed (Pericycle). Clinical results and data demonstrate that the sorbent system provides a suitable dialysate. The sorbents effectively remove uraemic metabolites from the dialysate. Calcium and magnesium removed by the cartridge and glucose metabolised by the patient are replaced by the infusion system. The machine pumps regenerated dialysate into and spent dialysate out of the patients. A pressure sensor in the patient line prevents excessive inflow and outflow pressures by stopping the inflow or outflow pump respectively. The Pericycle provides a simple, safe, portable method for conducting peritoneal dialysis in the home or hospital.

Aged↗
PubMed1977

Membrane marker analysis of 'lymphoid' and myeloid blast crisis in PH1 positive (chronic myeloid) leukemia.

The membrane phenotype of leukaemic cells was analysed during different stages of chronic myeloid leukaemia by a panel of markers. These included antisera against ALL antigen, p23,30 (Ia-like structure) and other T cell, B cell and myeloid markers 'Lymphoid' blast crisis shares the phenotype of common ALL (of non-T, non-B variety). Both leukemias react with anti-ALL serum and have pre-myeloid, pre-B lymphoid and pre-thymocyte characteristics. Their phenotype may reflect the characteristics of the pluripotential stem cell from which they derive. Nevertheless both leukaemias retain their undifferentiated characteristics and lack overt myeloid, B cell and thymocyte differentiation markers. Myeloid blast crisis and AML are negative with anti-ALL serum but some of the poorly differentiated myeloblasts react with anti-p23,30 serum (and negative for SmIg). The anti-p23,30 serum (used in a double marker assay combined with anti-immunoglobulin) detects some (4-11%) intermediate sized agranular p23,30+/SmIg-cells in peripheral blood during the chronic phase of CML as well as in normal foetal bone marrow. These could be myeloid stem cells (from which in CML the myeloid blast crisis arises). The results demonstrate that surface membrane analysis can aid exact diagnosis in different stages of CML.

Antigens, Neoplasm↗
PubMed1977

Evidence that Aspergillus fumigatus growing in the airway of man can be a potent stimulus of specific and nonspecific IgE formation.

Serum IgE levels in patients with allergic bronchopulmonary aspergillosis are elevated but the degree of elevation varies markedly. Serum IgE levels in patients with aspergillomas may be strikingly elevated or normal. Absorption of serums with antigens of Aspergillus fumigatus combined with a solid phase radioimmunoassay technic demonstrated that both immunoglobulin E (IgE) and immunoglobulin G (IgG) antibody activity against A. fumigatus were markedly reduced without a parallel reduction in serum total IgE. These results indicate that the very high levels of serum IgE found in allergic bronchopulmonary aspergillosis and aspergilloma are not all specific IgE. These results are similar to those observed in rats infested with Nippostrongylus brasiliensis. An explanation for the elevations of IgE levels in infestations with A. fumigatus may be analogous to the postulate that parasite-produced materials may result in T cell stimulatory factors for IgE-producing cells. Alternatively, A. fumigatus organisms may produce materials that inhibit T suppressor lymphocytes.

Aspergillosis↗
PubMed1977

Polymerization of mixtures of grass allergens.

Mixed grass pollen allergens were precipitated from crude grass extract by 90% saturation with ammonium sulfate. The precipitate was dissolved and polymerized with glutaraldehyde. Polymerized allergens with a molecular weight range of 200,000 to 4,000,000 were isolated. The resultant grass allergen polymers had reduced allergenicity but were capable of absorbing out IgG antibody from sera of 2 patients treated with crude grass allergens. This alteration of allergenicity was intended to reduce the ability of allergens to react with IgE-sensitized cells rather than to modify or destroy antigenic determinants. Prior exposure of allergens to phenol used as a preservative inhibited the polymerization process probably by blocking combining sites with which glutaraldehyde reacts.

Allergens↗
PubMed1977

Immunologic responses to therapy in allergic bronchopulmonary aspergillosis: serum IgE value as an indicator and predictor of disease activity.

Two patients, a child and an adult, with allergic bronchopulmonary aspergillosis were studied over an 18-month period. Initially elevated total serum IgE levels fell during prednisone therapy and rose prior to and during an exacerbation. Total serum IgG fell with therapy, whereas the values of IgA and IgM remained constant. Specific IgG and IgE values against Aspergillus fumigatus as measured by radioimmunoassay were elevated in both patients. Specific IgE values increased in each patient prior to exacerbation, whereas specific IgG values increased in only one patient at the time of exacerbation. Immunologic evaluation may provide an assessment of disease activity of prospective value.

Adolescent↗
PubMed1977

Sexual potency following surgery for rectal carcinoma. A followup of 44 patients.

Of 157 patients operated upon for cancer of the rectum within the last 10 years, 44 were available for a followup study of sexual potency. After the anterior resection operation, sexual function for both men and women remained practically unchanged. Following the abdominoperineal operation, where the entire rectum was extirpated, the results differed for men and women. Sexual function in men was completely destroyed, but women were capable of continuing sexual enjoyment as before the operation. Anterior resection in both sexes, i.e., leaving 6 cm of the distal rectum, does not destroy nerve fibers or other structures vital to continuing normal sex activity. However, the abdominoperineal operation in men destroys the important parasympathetic fibers to the male genital system and renders the patient impotent. In women, the abdominoperineal operation for cancer spares most of the nerve supply, especially the important pudendal nerve, thus permitting the patient to continue sexual activity as before surgery.

Aged↗
PubMed1977

Plasmid-mediated beta-lactamase production in Neisseria gonorrhoeae.

Several beta-lactamase-producing, penicillin-resistant strains of Neisseria gonorrhoeae were examined for R plasmids. Penicillin-resistant strains isolated from men returning from the Far East and their contacts contained a 4.4 x 10(6)-dalton plasmid in common. Transformation studies and the isolation of a spontaneous penicillin-susceptible segregant showed that the structural gene for beta-lactamase was part of the 4.4 x 10(6)-dalton plasmid. An additional penicillin-resistant gonococcal strain isolated in London was found to harbor a 3.2 x 10(6)-dalton R plasmid. Deoxyribonucleic acid (DNA)-DNA duplex studies revealed that the penicillin-resistant gonococcal isolates contained a significant portion (about 40%) of the transposable DNA sequence, TnA, which includes the beta-lactamase gene commonly found on R plasmids of the Enterobacteriaceae and Haemophilus influenzae.

DNA, Bacterial↗
PubMed1977

Molecular characterization of two beta-lactamase-specifying plasmids isolated from Neisseria gonorrhoeae.

The molecular nature of two distinct gonococcal R plasmids, 4.4 X 10(6) and 3.2 X 10(6) daltons, encoding beta-lactamase activity were examined. Both plasmids contained about 40% of the transposable ampicillin resistance sequence Tn2. Deoxyribonucleic acid-deoxyribonucleic acid polynucleotide sequence studies have shown that the two gonococcal plasmids share about 70% of their sequences and are closely related to RSF0885, a 4.1 X 10(6)-dalton plasmid found in a beta-lactamase-producing strain of Haemophilus influenzae. All three of these R plasmids possess a guanine-plus-cytosine content of 0.40 to 0.41 mol fraction and are present as multicopy gene pools in their bacterial hosts.

Base Sequence↗
PubMed1977

Living histamine-containing cells from the bronchial lumens of humans. Description and comparison of histamine content with cells of rhesus monkeys.

Cell populations obtained by bronchial lavage from human subjects were examined for the presence of cells related to the mast cell-basophil series. Such bronchial lumen histamine-containing cells (BLHCC) were identified. The BLHCC stained with toluidine blue may be identified by bright field or dark field microscopy. The BLHCC are alive as evidenced by ability to release histamine (H) after exposure to anti-IgE or calcium ionophore. Although H release from peripheral blood leukocytes by these two agents is potentiated by the presence of D2O, H release from BLHCC of the same subjects by anti-IgE or calcium ionophore was not potentiated by D2O. In studies comparing bronchial cell populations of humans and rhesus monkeys with peripheral blood leukocyte populations of the same subjects, the histamine content of the bronchial cell population was much higher in rhesus monkeys. IgE/Alb ratios of respiratory secretions and serum of the same human subjects were of the same order of magnitude in contrast to previous comparisons done on these fluids in rhesus monkeys.

Animals↗
PubMed1977

In search of a 24 hours per day artificial kidney.

Wearable, 24 hrs per day, 7 days per week artificial kidneys are being developed. Patients will benefit from more even control of physiologic parameters than can be obtained with conventional intermittent dialysis. Improvement in economic and social circumstances will result. Both hemodialysis and peritoneal dialysis techniques are being miniaturized. Small REDY cartridges containing urease, zirconium phosphate, hydrouse zirconium oxide and activated carbon are being utilized to regenerate dialysate. Hemodialyzers will be worn on the forearm and include long, wide, low resistance series blood flow paths to reduce the potential for thrombosis. Peritoneal effluent is regenerated and filtered by the sorbent cartridge and automatically cycled back into the peritoneal cavity.

Animals↗
PubMed1977

Clinical and immunologic criteria for the diagnosis of allergic bronchopulmonary aspergillosis.

Clinical and immunologic characteristics are reported in a series of 20 patients with allergic bronchopulmonary aspergillosis seen by physicians in one consulting service during a period of 9 years. Seventeen of these patients have been identified in the past 2 years, reflecting the increasing recognition of the entity. Fifteen of the 20 patients are believed to have proven diagnoses; the other five are strongly suspected. Asthma, pulmonary infiltrates, and eosinophilia are the usual presenting symptoms. Serum immunoglobulin E was markedly elevated in all patients, and serum immunoglobulin D was normal in four out of five patients sampled. Bronchograms were abnormal in all cases in which they could be done. Lymphocyte transformation may be present in some cases but is not a diagnostic feature. The average age at time of diagnosis was 25.5 years, and seven of the 15 proven patients were 20 or younger.

Adolescent↗
PubMed1977

Immediate-type hypersensitivity to keyhole limpet haemocyanin in the dog.

A model of immediate-type hypersensitivity (ITH) in the dog using keyhole limpet haemocyanin (KLH) as the antigen was studied. Long-lasting ITH was induced in fifteen of sixteen dogs by the i.v. (Kepron & Tse, 1975), intradermal (Rockey, Schwartzmann & Halliwell, 1971), inhalation (Patterson & Kelley, 1974) and i.d. plus inhalation (Rockey et al., 1971) routes. This ITH was demonstrated by direct skin reactivity, acute respiratory reactions and peripheral blood leucocyte and respiratory cell histamine release. The reaginic antibodies considered to mediate these reactions were larger than canine IgG, heat labile, 2-mercaptoethanol sensitive, and are probably canine IgE. In addition to cutaneous and respiratory reactions, these reagins were shown to mediate systemic reactions. In the course of these studies, an unexpected finding was the occurrence of ITH to KLH in three dogs which had had no prior experimental exposure to KLH. This ITH was of sufficient intensity to be associated with acute airway reactions to the inhaled antigen.

Animals↗