Search PubMed⌕ Search

Biomedical subjects

B Atkinson

Publications and source records attributed to B Atkinson.

At least 73 records · Page 4Linked to original sources
PubMed1984

Monoclonal antibody localization of A and B isoantigens in normal and malignant fixed human tissues.

The expression of human blood group A and B isoantigens in normal and malignant tissues from stomach, colon, and pancreas was analyzed in an immunoperoxidase assay using monoclonal antibodies specific for these isoantigens. Appropriate isoantigen expression was demonstrated in the normal epithelium from the stomach, pancreas, and proximal but not distal colon of blood group A, AB, or B patients. Half of all gastric carcinomas and of proximal colon carcinomas showed complete loss of isoantigen, whereas the adjacent mucosa in these cases continued to express appropriate isoantigen. Isoantigen expression was completely lost in only 13% of pancreatic carcinomas tested. Neither A nor B isoantigen was detected in normal epithelium from the distal colon. By contrast, 85% of carcinomas derived from this site showed reexpression of isoantigen. Inappropriate expression of A isoantigen was detected in pancreatic carcinomas (2/5) but not in gastric or colon carcinomas (0/21). Inappropriate expression of B substance was not detected in any tissue (0/38). Interestingly, differential binding of antibodies to Type 1 versus Type 2 and/or difucosyl versus monofucosyl blood group B substances was manifested by differences in intensity of staining for endothelium and red blood cells.

ABO Blood-Group System↗
PubMed1984

Identification of melanoma-associated antigens using fixed tissue screening of antibodies.

Early culture supernatants from hybridomas that were obtained through fusions of mouse myeloma cells with lymphocytes of melanoma-immunized mice were screened for their reactivity with a paraffin-embedded cell block of a melanoma cell line, using a biotin:avidin immunoperoxidase procedure. Eleven monoclonal antibodies were derived that define several new melanoma-associated antigens. The antigens include a neutral glycolipid, gangliosides, membrane-associated proteins, cytosolic proteins, and strongly secreted proteins. These antibodies, which detect antigens that withstand tissue fixation and embedding procedures, were tested for reactivity in fixed cell lines, as well as in melanoma biopsies. These antibodies may provide powerful tools in diagnostic studies of human malignant melanoma biopsy material.

Animals↗
PubMed1983

Monoclonal antibodies derived from immunosuppressed mice grafted with human melanoma.

Hybridoma cells producing monoclonal antibodies against tumor-shed antigens were generated by fusing mouse myeloma cells with spleen cells from immunosuppressed mice bearing human melanoma xenografts. Thirty-eight fusion experiments were performed at different stages of tumor growth. Hybridomas producing anti-melanoma antibodies were obtained from 12 spleens in mice bearing 1-4-week-old tumors but at later stages of tumor growth, no hybridomas whatsoever could be obtained. However, the sera of all mice tested showed anti-melanoma antibody binding reactivity at the time of fusion. Using radioimmunoassay (RIA) to select specific antibody secreting hybridoma cultures, the majority of cultures were found to produce antibodies which bound to both 3 M KCl melanoma extracts and melanoma culture supernatants. No stable cultures secreting membrane-reactive (live tumor cell targets) antibodies could be obtained. All of the monoclonal antibodies bound not only to melanoma target cell preparations, but also to preparations from tumors of other origins and only 3 did not bind to normal human fibroblasts. The crossreactivity pattern of binding was confirmed in immunoperoxidase (IP) assays by binding to human tissue sections. The immunosuppressed mouse bearing human tumor xenografts has proven a useful system for production of monoclonal antibodies against antigens shed by tumor cells.

Animals↗
PubMed1983

Phagocytosis of filaments of Escherichia coli produced with mezlocillin.

The phagocytosis of filaments of Escherichia coli produced with mezlocillin differs from the phagocytosis of normal bacilli in that pseudopods are employed for bacilli, but the entire body of the polymorphonuclear cell (PMN) participates in the engulfment of a filament. A single PMN was observed phagocytizing one or more filaments 20-50 micron long. The mass of a filament is about ten times larger than the mass of a bacillus. When equal bacterial mass, one filament or 10 bacilli, is exposed to PMNs comparable bacterial killing results after 2-3 h of incubation.

Blood Bactericidal Activity↗
PubMed1983

Mild cervical dysplasia. Experience in a family planning clinic.

To evaluate mild cervical dysplasia, the results of Papanicolaou smears were reviewed for a six-month period in an inner-city family planning program. Papanicolaou smear evidence of mild dysplasia was consistent with the biopsy diagnosis in most cases. A single Papanicolaou smear is not a reliable indication of condylomata, nor is a single normal Papanicolaou smear in this setting completely reassuring. Persistent mild dysplasia is an indicator of high risk for cervical dysplasia and cervical infection. Aggressive initial cervical surgery is not indicated, but close follow-up is required.

Adolescent↗
PubMed1982

Phase-I clinical trial of monoclonal antibody in treatment of gastrointestinal tumours.

A phase-I clinical trial of a murine monoclonal antibody that specifically suppresses growth of human gastrointestinal tumours in athymic mice was conducted in four patients, who were given 15-200 mg purified antibody. The monoclonal antibody persisted in the circulation for more than a week when more than 15 mg was given. Antibodies against mouse immunoglobulin developed in three of the four patients. In one patient who received autologous mononuclear cells that had been mixed with monoclonal antibody by way of a hepatic-artery catheter, hepatic metastases became smaller and their echogenic characteristics changed, and there was heavier monocyte infiltration in the histological appearance of a resected metastasis.

Adenocarcinoma↗
PubMed1980

Killing of oxacillin-exposed staphylococci in human polymorphonuclear leukocytes.

Twelve strains of Staphylococcus aureus isolated from patients and two collection strains were grown on membranes placed on agar containing subminimal inhibitory concentrations of oxacillin. Clusters of staphylococci held together by thick cross walls resulted. These organisms, as well as the same strains grown in the same way on drug-free medium (control), were eluted from the membranes and were incubated with human polymorphonuclear leukocytes (PMNs) from various donors. Phagocytosis was comparable for both staphylococci exposed to oxacillin and control staphylococci, but the killing effect was different. The staphylococci grown on membranes in the presence of oxacillin were less susceptible to killing than the control staphylococci, but the killing effect was different. The staphylococci grown on membranes in the presence of oxacillin were less susceptible to killing than the control staphylococci. After 0.5 and 1 h of incubation with PMNs, the killing rates for oxacillin-grown versus control staphylococci were 52 and 70% and 65 and 85%, respectively (P < 0.01). After 2 and 3 h of incubation, the killing was similar. Most clusters of staphylococci contain a few individual cells that are located in the center of the cluster and are surrounded by other staphylococci; therefore, they are protected from adverse agents in the environment. This could explain why the phagocytized clusters are less susceptible than control staphylococci to the killing effect of PMNs during the first hour of incubation. Oxacillin does not penetrate into PMNs and in the absence of the drug the cross walls lyse, liberating the constituent staphylococci. This coincides with the increase in the percentage of cluster killing by PMNs after 2 and 3 h of incubation.

Adult↗
PubMed1979

Clinical evaluation of the MICRO-ID, API 20E, and conventional media systems for identification of Enterobacteriacea.

MICRO-ID (General Diagnostics, Morris Plains, N.J.) is a new kit system designed for the identification of Enterobacteriaceae in 4 h. It consists of 15 biochemical tests of paper disks. Each test is in its own compartment in a molded plastic tray. Only one reagent need be added to the system (2 drops of 20% KOH, which is added to the Voges-Proskauer test). Based on the pattern of positive and negative biochemical test results, a five-digit octal code number is calculated. An identification is derived from a computer-generated identification manual. A study was conducted to compare three systems-the MICRO-ID 4-h and the API 20E (Analytab Products Inc., Plainview, N.Y.) 18- to 24-h systems and a conventional media system-to measure the ability of each to identify members of the family Enterobacteriaceae. Comparison tables, rather than simple percentage agreement tables, were generated to define the particular strengths and weaknesses of each system and allow the laboratory to best use the data. The MICRO-ID compared quite favorably with conventional media. MICRO-ID yielded incorrect identifications with 1.5% of the isolates tested (API 20E, 4.7% misidentification rate). Half the MICRO-ID misidentifications occurred when the system identified a Citrobacter diversus as a lysine-negative Escherichia coli; all gave one octal number. A direct comparison of the MICRO-ID and API 20E was of limited value because percentage agreements were merely the sums of the errors of each. The ease of inoculation, the requirement for the addition of only one reagent, and the 4-h capability make the MICRO-ID system an extremely attractive development in the field of bacterial identification.

Bacteriological Techniques↗
PubMed1978

Adolescent parent education: a maturational model.

Health care, educational and social programs are frequently required to assist increasing numbers of adolescent mothers to meet their own needs and those of their babies. This paper presents a maturational rationale for development of a comprehensive parent education program. Some pertinent aspects of adolescent psychological development are first presented to provide a perspective for understanding the models illustrating the teenage mother's responses to her child. Barriers are then delineated which commonly restrict the young mother from attaining the mature relationship with her baby presented in a maturational model. Specific recommendations are offered in the areas of program development, content, and structure.

Adolescent↗
PubMed1978

Cyclic adenosine monophosphate excretion in urine of patients and carriers of congenital nephrogenic diabetes insipidus.

Urinary excretion of cyclic adenosine monophosphate (cAMP) is assessed in response to pitressin stimulation in three patients with nephrogenic diabetes insipidus, four carriers and seven controls. There is no significant difference in cAMP excretion between these groups when corrected for surface area, nor is there any significant increase in excretion after pitressin stimulation. There is very close correlation between urinary cAMP and both urinary concentration and urinary creatinine excretion. Urinary cAMP after pitressin stimulation does not discriminate between carriers of nephrogenic diabetes insipidus and control subjects.

Adult↗
PubMed1978

Effect of serum on gram-positive cocci grown in the presence of penicillin.

Strains of Staphylococcus aureus, Streptococcus faecalis, Streptococcus bovis, and a strain of Streptococcus that produces filaments were grown on agar containing penicillin at concentrations of one-half to 1/10th the minimal inhibitory concentration. These penicillin-exposed organisms as well as untreated control organisms were incubated with human serum of plasma. Both serum and plasma produced a remarkable bactericidal effect on the filament-forming Streptococcus grown in the presence of penicillin, whereas the untreated control was only slightly affected. This response resembled that of gram-negative bacilli rather than that of gram-positive cocci. The growth of staphylococci exposed to penicillin was slightly inhibited in the presence of serum, whereas the growth of untreated staphylococci was stimulated. The streptococci, regardless of whether they were treated with penicillin or whether they were untreated, showed no change in growth pattern in the presence of serum.

Agar↗
PubMed1978

Bronchioloalveolar carcinoma: two clinical entities with one pathologic diagnosis.

Bronchioloalveolar carcinoma may present with a variety of radiologic and clinical patterns. Two types of this primary carcinoma of the lung have been recognized: a solitary lesion and a diffuse form. Charts and radiographs of 61 cases of bronchioloalveolar carcinoma were reviewed as well as the pertinent literature. Our experience indicates that the localized form seldom, if ever, becomes diffuse and has a good prognosis following appropriate surgery (lobectomy or pneumonectomy). If the lesion is diffuse, death almost invariably results within 3 years. Based on available clinical information, we suggest that at least two primary tumors of the lung have the histologic pattern of bronchioloalveolar carcinoma: one of these tumors is diffuse and the other is solitary.

Adenocarcinoma, Bronchiolo-Alveolar↗