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Biomedical subjects

J de Graaff

Publications and source records attributed to J de Graaff.

At least 163 records · Page 9Linked to original sources
PubMed1980

Virulence of Escherichia coli in acute pyelonephritis, acute cystitis and asymptomatic bacteriuria.

E. coli strains were isolated from urine specimens of hospitalised patients with acute pyelonephritis, acute cystitis or asymptomatic bacteriuria (ABU), and tested for virulence in an experimental mouse model. Of 12 pyelonephritis-strains 11 were shown to be virulent and 1 avirulent; of 12 cystitis-strains 4 were virulent and 8 avirulent; of 12 ABU-strains 5 were virulent and 7 avirulent. It is concluded that, while no difference in virulence was found between cystitis- and ABU-strains, pyelonephritis-strains were more often virulent than cystitis- and ABU-strains. No associations could be shown between virulence of the isolated strains and the presence of antibody-coated bacteria in the urine. Common urinary O types were not more often virulent than other O types. No relationship was seen between virulence and the presence of K antigen or the presence of particular K types.

Acute Disease↗
PubMed1980

Alpha-fetoprotein in ovarian teratoma with glial implants on the peritoneum.

A case of ovarian teratoma with glial implants on the peritoneum associated with alpha-fetoprotein (AFP) in the blood is reported. After repeated surgical excision the AFP became negative. The AFP can also be considered as a tumor marker in case of ovarian teratoma. The literature concerning ovarian teratoma with glial implants on the peritoneum is reviewed. The pathogenesis of glial implantation on the peritoneum and the association with AFP is discussed.

Child↗
PubMed1980

Mannose-sensitive and mannose-resistant adherence to human uroepithelial cells and urinary virulence of Escherichia coli.

The adherence to human uroepithelial cells of 23 Escherichia coli strains belonging to three groups with different levels of virulence was investigated, and the mechanism of adherence was studied. It was found that strains belonging to the most virulent group adhered better to human uroepithelial cells than did avirulent strains. Adherence of loss virulent but supposedly nephropathogenic strains was more variable. These results suggest that adherence is an important virulence factor, especially in the group of strains with the highest but a more general virulence. Piliated strains adhered better than did nonpiliated strains. We found strong evidence for the existence of at least two different mechanisms of adherence: (i) mannose-sensitive adherence by piliated strains, very likely mediated by type I pili because this mannose-sensitive adherence was associated with mannose-sensitive hemagglutination of guinea pig erythrocytes by broth cultures of the strains; (ii) mannose-resistant adherence by piliated strains, very likely mediated by non-type I pili because this mannose-resistant adherence was invariably associated with mannose-resistant hemagglutination of human group A erythrocytes by the strains, whether grown in broth or on plates. Additionally, one strain without pili and without hemagglutinating activity adhered well. Thus in most cases adherence seemed to be mediated by bacterial pili, although different types might be involved.

Adult↗
PubMed1979

Phagocytosis and intracellular killing of coagulase-negative staphylococci.

The phagocytosis and intracellular killing of different coagulase-negative staphylococcal species by polymorphonuclear (PMN) leukocytes from one healthy donor were compared. The uptake of strains belonging to a given species varied from 60 to 80% with an average of 70% after 20 min incubation at 37 degrees C. Up to 95% of intracellular bacteria were killed after 10 min. There was no correlation between uptake capacity and species or biotype. The average rates of phagocytosis and killing strains whether isolated from urinary tract infections or from the skin were virtually the same.

Cells, Cultured↗
PubMed1979

Virulence of Escherichia coli in experimental hematogenous pyelonephritis in mice.

Differences in nephropathogenicity between Escherichia coli strains were studied by following the kinetics of the viable count in the mouse kidney during 8 h after intravenous injection. Assuming as a reference point that at zero time 0.1% of the inoculum was lodged in the kidney, we found that strains fell into three main groups with different behavior patterns: in group I, the viable count fell and remained low; in group II, the viable count first fell and then rose after 4 h, reaching the level of the reference point within 8 h; in group III, the viable count rose rapidly and remained high. The kinetics of the viable counts were also studied in blood, spleen, and liver: group I and II strains behaved similarly; only in the kidney did group II strains show higher counts than group I strains. These data suggest that group II strains are specifically virulent for the mouse kidney. Group III strains also gave higher viable counts in blood and spleen but comparable counts in the liver, suggesting that group III strains are more generally virulent. Fifty percent lethal dose measurements confirmed the conclusion that group I strains are avirulent and group III strains are the most virulent. Possible relationships between behavior pattern and serotype are discussed.

Animals↗
PubMed1978

Taxonomy of coagulase-negative staphylococci: a comparison of two widely used classification schemes.

In a comparative study 351 strains of Micrococcus subgroups 1-3 (Baird-Parker, 1963, 1965, 1974) were classified according to the Kloos and Schleifer scheme (1975b). The results showed that Micrococcus subgroups 1, 2 and 3 are heterogeneous groups in the Kloos and Schleifer scheme. Strains belonging to Micrococcus subgroups 1 and 2 were mostly classified by the Kloos and Schleifer criteria as Staphylococcus hominis, Micrococcus subgroup 3 strains from the skin as S. cohnii, while Micrococcus subgroup 3 strains from urinary infections were classified mainly as S. saprophyticus. The correlation of novobiocin resistant S. saprophyticus biotype III (Baird-Parker, 1974) with S. saprophyticus (Kloos and Schleifer, 1975a, 1975b) when isolated from urine, was 80%. Although the Kloos and Schleifer scheme provides more information about biochemical characters, doubts are expressed about the validity of some of the species so delineated.

Bacteriological Techniques↗
PubMed1978

Age at menarche and menopause of uterine cancer patients.

An investigation was undertaken of the ages at menarche and at menopause of cervical and endometrial cancer patients for the years 1950-55 and 1960-65. Analysis of the ages at menarche in relation to the year of birth did not show a difference between the uterine cancer groups, whereas the age at menopause did show such a difference. The menopause occurred later in the endometrial than in the cervical cancer group. There was an earlier mean age at menarche and a later mean age at menopause per decade. Therefore, the menopause seems a constitutional factor involved in the development of endometrial cancer and perhaps also cervical cancer.

Adolescent↗
PubMed1978

Replication of the nonconjugative plasmid RSF1010 in Escherichia coli K-12.

Replicating DNA molecules of the nonconjugative R plasmid RSF1010 (Smr Sur) were cleaved with the EcoRI restriction endonuclease and examined with the electron microscope. Results of this analysis indicated that replication is initiated from an origin located at about 19% of total genome size from one of the EcoRI ends. Replication proceeded either unidirectionally or bidirectionally with equal frequency. Results of the analysis of replicative intermediates of RSF1010 containing the Apr-transposable sequence (Tn) are also presented.

DNA Replication↗
PubMed1977

Marriage and childbearing in relation to cervical cancer.

In order to assess any correlation between cervical cancer and age at marriage and childbearing, matched control groups were formed. From the comparison it appears that cervical cancer patients are more likely to be married and to have married at an earlier age than control women. In the same age groups at marriage there was no difference in the number of children between the cervical cancer patients and the control women. It appeared that cervical cancer patients had their first child earlier than control women. There were more illegitimate children in the cervical cancer groups than in the control groups, but after the wedding date there were no differences between the cervical cancer groups and the control groups in the time between the wedding date and the date of birth of the first child. The data show that after pregnancy or childbirth, in particular at an early age, there is a greater risk of getting a cervical cancer. By contrast, nulliparous married women seem to have a low risk of cervical cancer.

Adolescent↗
PubMed1975

[Episiotomy].

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Episiotomy↗