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Biomedical subjects

W D Grahlow

Publications and source records attributed to W D Grahlow.

17 recordsLinked to original sources
PubMed1989

Occurrence and significance of Clostridium difficile in faecal specimens of hospitalized children.

Stool specimens from 766 hospitalized children, 418 with diarrhoea and 348 controls, were investigated for C. difficile. In both groups the rate of isolation was highest (about 30%) during the first year of life, dropping to nearly 5% in older children. There was no significant difference in the frequency of C. difficile in children with diarrhoea and the controls nor was there a significant influence of previous antibiotic therapy on the rate of isolation. 111/135 strains (82.2%) produced toxin B and 58/135 strains (43%) produced toxin A measured by Y-1- cell culture (toxin B) and rabbit ileal loop test (toxin A). We did not find any significant difference in the toxin production between strains isolated from diarrhoeal children and from the controls. A total of 285 stool specimens was investigated for toxin B production in vivo. There was no significant difference of toxin B in the stool specimens of both groups.

Adolescent↗
PubMed1985

[Cell wall proteins of Escherichia coli: a substance resembling the thermolabile enterotoxin (LT)].

In ultrasonic extracts of all 19 investigated non-enterotoxigenic E. coli strains a substance (LTLS) could be detected reacting positively in all tests which are commonly used to detect specifically E. coli thermolabile enterotoxin (LT). Culture supernatants of these strains in general did not contain LTLS in detectable amounts. LTLS can be found in the whole cell, however, the membrane fraction contains the highest quantities. Released LTLS appears mainly aggregated with components of the cell wall, especially with lipopolysaccharides. This fact in combination with the very low quantities produced by the bacteria renders very difficult purification of LTLS.

Animals↗
PubMed1980

[Comparison of the Limulus test with the pyrogen test in rabbits].

The Limulus test was compared with the official pyrogen test in rabbits for detecting pyrogens in medical devices for single use. 46 samples were examined. Two of them were positive in the rabbit test and also in the Limulus test; 5 samples were only positive in the Limulus test. This is in agreement with published papers. Against endotoxins of gram-negative bacteria the Limulus test is more sensitive than the common test in rabbits, but not sensitive for other pyrogens. Therefore, the Limulus test cannot replace the official rabbit test in the quality control of medical devices. We recommend the Limulus test as a quick, simple and highly sensitive screening method for gram-negative bacterial endotoxins, the most common pyrogen contaminants in drugs.

Animals↗
PubMed1979

[Cholera today].

Explore the source record for details and available documents.

Acid-Base Equilibrium↗
PubMed1978

[Laboratory experiments with a polyvalent extract vaccine for oral immunization against E. coli enteritis].

Bacteria of E. coli causing enteritis can be extracted by EDTA-sodium. These extracts having lower dry weights result in better protective effects in contrast to sodium-deoxycholate extracts. The EDTA-sodium extracts can be concentrated, purified and sterile filtrated. Thus the production of polyvalent vaccines is possible. A direct relation exists between the effectiveness of the extracts and the virulence of the strains used for extraction. The more virulent the original strain the better is the protective effect of the vaccine produced by extraction of the original strain. The single components of the polyvalent vaccine show a certain improvement of their protective effects. For estimating the immunizing dose, it is necessary to consider the limiting dose. When exceeding this dose the protective effect or the vaccine does not further increase but remains constant of even decreases. The immunizing dose wanted must be greater than the ED50 but smaller than the limiting dose. Extremely high oral doses of vaccine result in symptoms of incompatibility in mice.

Administration, Oral↗
PubMed1977

[Resection and enteroanastomosis in the ligated rabbit gut test as a modified and sparing operating procedure (author's transl)].

For detection of heat labile enterotoxin of E. coli we also carried out the ligated rabbit gut test, which was complicated by a high primary mortality. We modified the operating technique as follows. We interrupted the continuity of the ileum by resection of the segment containing the loops and restored the passage by an end-to-end-anastomosis of the oral and aboral stumps of the gut. The technique is explained by pictures. The strains from patients were incubated in Brain Heart Infusion broth (Difco) by 37 degrees C for 48 hours without shaking. The strains were tested both as suspensions and as sterile filtrates by injection of 2 ml each using positive (O 148:-:28, B 7 A) and negative controls (U 5/41 O 1:K1:H7, neotype strain). We used rabbits (Helle Grosssilber) weighing 1500 to 2500 g. Operation was performed under general anaesthesia with pentobarbital (SPOFA) and under aseptic conditions. After a period of 18 hours the animals were killed, and the index of enterosorpiton was estimated. An index of 1.0 or greater was regarded as positive. This technique is an sparing procedure, the artificial ileus is avoided, the surviving rate of the rabbits is higher, and the possibility is given to carry out long time studies on enteropathogenetic problems. The results of our studies on 17 rabbits with a total number of 100 loops are summarized in a table.

Animals↗
PubMedDate not supplied

Meningococcal infections in the German Democratic Republic 1971-1984.

Since May 1979 all meningococcal strains isolated in the GDR have been investigated microbiologically. Despite a generally low incidence, a marked increase in meningococcal infections has been observed. From a total of 650 strains sent to our institute up to 1984, 515 could be serogrouped. 54 strains belonged to serogroup A, 292 to B, 125 to C, two to X, eight to Y, one to Z, 30 to W-135 and three to 29E. There were no substantial changes in the distribution of the groups. In our study we tried to find out whether there are any correlations between the epidemiological and microbiological data. A record was made of the age distribution, clinical picture and regional distribution of the meningococcal strains isolated. Rifampicin chemoprophylaxis of contacts was introduced in 1981.

Age Factors↗