Search PubMed⌕ Search

Biomedical subjects

D G Anderson

Publications and source records attributed to D G Anderson.

At least 55 records · Page 3Linked to original sources

Simple and rapid method for isolating large plasmid DNA from lactic streptococci.

A procedure for the rapid isolation of plasmid DNA larger than 30 megadaltons from lactic streptococci is described. This protocol can be used on a preparative scale to isolate sufficient quantities of plasmid DNA required for restriction analysis, cloning, or transformation experiments. A scaled-down protocol is very useful for rapidly screening the plasmid content of streptococcal strains. With this methodology, previously undetected large plasmids were observed.

DNA, Bacterial↗

Isolation of a recombination-deficient mutant of Streptococcus lactis ML3.

A recombination-deficient mutant of Streptococcus lactis ML3 designated MMS36 was isolated on the basis of its sensitivity to methyl methanesulfonate. This mutant also displayed sensitivity to UV irradiation. The inability of MMS36 to mediate homologous recombination was demonstrated by transduction of plasmid-linked lactose fermenting ability but not chromosomally mediated streptomycin resistance.

Lactococcus lactis↗

Endometrial carcinoma: causes of death and sites of treatment failure.

A retrospective analysis of causes of death in 398 patients with endometrial carcinoma and sites of treatment failure in 105 cases, all seen at the University of Michigan Medical Center between 1930 and 1971, is the subject of this report. Of 398 patients (337 with Stage I, 61 with Stage II disease), 183 (46%) died with endometrial carcinoma, and 122 (31%) died free of cancer. The cause of death in 35 cases (9%) was a known or unknown maligancy, and remained undetermined in 58 patients (14%). The exact site of treatment failure was identified in 105 cases. Forty-one (40%) failures were considered local, 32 (30%) geographic, and 32 (30%) both local and distant. The uterus and lungs were the most common sites of local failure and distant metastasis, respectively. Of patients who died free of cancer, 88% survived 5 or more years, and 32% survived 20 years or longer. It is concluded that 1) Hematogenous dissemination of endometrial carcinoma may occur early and with appreciable frequency. Thorough pretreatment investigative workup, preferably including chest laminograms and liver scans and consideration of adjuvant systemic therapy in advanced cases (i.e. those with positive nodes) is recommended. 2) The uterus, a common site of local failure, must be removed whenever feasible. 3) A realistically aggressive approach to the treatment of patients with endometrial cancer is justifiable despite their older age and coexistent medical problems.

Adolescent↗

Benign gestational trophoblastic disease metastatic to pleura: unusual cause of hemothorax.

A unique case of hemothorax caused by proven pleural involvement with benign gestational trophoblastic disease and anticoagulation is presented. The pulmonary manifestations of gestational trophoblastic disease are reviewed. It is stressed that these may be associated with histologically benign as well as frankly malignant disease, and that the clinician must be alert for them in managing all patients with known or suspected gestational trophoblastic disease.

Adolescent↗

Plasmids, loss of lactose metabolism, and appearance of partial and full lactose-fermenting revertants in Streptococcus cremoris B1.

The unstable ability to metabolize lactose (lac) via the phosphoenolpyruvate-phosphotransferase system (PTS) was examined in Streptococcus cremoris B1. The presence of functional lactose-specific PTS enzymes was correlated with the presence of a distinct plasmid species. Characterization of deoxyribonucleic acid extracted from lactose-positive (Lac+) S. cremoris B1 revealed two plasmids having molecular weights of 9 X 10(6) and 36 X 10(6). An acriflavine (BC1)-induced, lactose-negative (Lac-) mutant possessed no plasmids and was devoid of all three lac-specific PTS enzymes. A Lac- mutant (DA2) isolated by growing at elevated temperatures only possessed the 9 X 10(6)-dalton plasmid and also lacked the lac PTS enzymes. A spontaneous Lac- mutant possessed both the 9 X 10(6)-and 36 X 10(6)-dalton plasmids. This mutant displayed FIII-lac and phospho-beta-D-galactosidase (P-beta-gal) activity but was deficient in EII-lac activity. The spontaneous Lac- strain reverted to both full and partial lactose-fermenting phenotypes having FIII-lac, EII-lac, and P-beta-gal activities. BC1 and DA2 Lac- mutants reverted only to the partial lactose-fermenting phenotype having P-beta-gal activity; EII-lac and FIII-lac activities were absent. The results indicate that the genetic determinants for EII-lac, FIII-lac, and P-beta-gal are located on the 36 X 10(6)-dalton plasmid in S. cremoris B1. Evidence for a second chromosomally associated P-beta-gal gene operating in the partial lactose-fermenting revertants is also presented.

DNA, Bacterial↗

The cytologic diagnosis of endometrial adenocarcinoma.

An outpatient diagnositc technique comparable to the Papanicolaou smear for carcinoma of the cervix is needed to permit early recognition of adenocarcinoma of the endometrium. Five different techniques of sampling the endometrial cavity were carried out on 1, 742 patients at the University of Michigan Medical Center. A total of 2,553 specimens were correlated with operating room curettings to assess the accuracy of each sampling technique. The methods of saline irrigation with an antrum cannula, endometrial brush sampling, high-vacuum aspiration, and the Gravlee jet washer proved not to be accurate enough to be used as a routine screeening test. There was excellent correlation (96 per cent) between endometrial biopsies and curettings. In our experience, endometrial biopsy with a suction or basket curette was the diagnostic technique short of curettage which permitted accurate diagnosis.

Adenocarcinoma↗

The effect of immunizing female rats with modified rat pituitary extract.

Immune reactions to a number of hormones have been induced, but information is lacking on the feasibility of inducing immune reactions to homologous gonadotropins. Female rats immunized with diazotized and tyrosylated rat pituitary extract containing gonadotropic activity and emulsified in complete Freund's adjuvant expressed various reproductive disturbances such as increased cycle length (7.0 days), increased number of sterile matings, reduced implantation in animals becoming pregnant, and reduced ability to carry fetuses to term. These effects were not exhibited by rats immunized similarly with diazotized or tyrosylated rat pituitary extract containing no detectable gonadotropic activity. Rats not becoming pregnant had a significantly higher antibody level to rat luteinizing hormone than did rats becoming pregnant. No significant elevation of rat follicle-stimulating hormone antibodies was noted. It is concluded that auto-immune reactions to gonadotropins can be induced and that very low levels of antibodies have a significant effect on reproduction.

Animals↗

Implanted amniotic membrane as an autograft and as an allograft.

Detailed studies on autograft and allograft amniotic membranes implanted in the subcutaneous tissues to form tunnels are described. Autograft amniotic membranes appear to become permanent structures whereas allografts of this material, though accepted by the host for a longer time than most allografts, were eventually rejected. Serial histological studies were performed.

Amnion↗

Amnion autografts, permanent structure.

Autografts of amniotic membrane were used to form tubes or conduits in lambs. These conduits survived for periods up to 9 months. The possibility of a clinical application has been explored.

Amnion↗

Wound healing and the amniotic membrane.

The successful clinical application of the amniotic membrane as a surgical dressing is discussed as to the mode of healing. The amniotic membrane does not appear to be a permanent structure when used as an allograft.

Amnion↗

Neighborhood screening in communities throughout the nation for children with elevated blood lead levels.

From the spring of 1971 to September 1973, neighborhood surveys were conducted in 58 communities throughout the nation to determine whether children with confirmed elevated blood lead levels could be identified. Another purpose of these screenings was to assist communities in identifying children with elevated blood lead levels and thereby demonstrate to community officials that such children do exist in communities screened. The children screened were not a random sample.In those communities where the initial elevated blood levels were confirmed all but seven had one or more children requiring followup and/or treatment. Of those children screened, black children had an elevated rate about three times as great as nonblack children. With few exceptions, the homes in the neighborhoods had at least one interior surface with sufficient quantities of lead paint to be dangerous if the paint were ingested.

Black or African American↗