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Biomedical subjects

L Schwartzbrod

Publications and source records attributed to L Schwartzbrod.

41 records · Page 3Linked to original sources
PubMed1977

[Evaluation of the alginat membrane filter method for the Enterovirus concentration in water (author's transl)].

It is bound to use a concentration method for the research of enteroviruses in water. One of the concentration methods, the filtration on alginat membranes, avoids the problem of the virus elution from the filter, then the membrane is soluble in a sodium citrat buffer. This method was studied with different types of water (synthetic water, tap water and wastewater). -The recovery efficiency of Poliovirus I in clear waters (synthetic water and tap water) was poor, unsatisfying reproducible; the results are better for small virus concentrations. This efficiency may be slowly enhanced by the addition to the sample of aluminium chlorid at a final concentration of 5.10(-4) M. -The technical problems (brittleness of the membranes, slow filtrations speed, small sample volume), soon noticeable with clear waters, are more important in the case of trouble waters. Meanwhile the use of this filtration method gives better results for the recovery of Poliovirus I in wastewaters than the direct inoculation to cells cultures.

Alginates↗
PubMed1975

[Concentration of viruses in water by the 2 phase polymer method: quantitative study].

The authors attempt to determine the sensibility of polymer two phases system applied to the concentration of viruses from water. They show that this technic agrees to the research of poliomyelitic viruses in waters since viral recuperation is always upper than 74.5%. Besides, they notice that average percentages of regained viruses are always 100% where the initial concentrations of viruses are 10(2) or 10(3) per liter; on the other hand if the initial concentration is higher the yield of this method is decreasing.

Poliovirus↗
PubMedDate not supplied

[Study of the behavior of poliomyelitis virus type 1 in diffrerent hydrous media (author's transl)].

After having analyzed several surveys on natural inactivation of viruses in water, the authors have attempted to determine the survival life of poliomyelitis virus type 1 in hydrous medium, of known composition, well-buffered and devoid of any bacterial contamination on the one hand, and on the other hand, in a similar medium with addition of organic humate-type substances. The experiment was carried out at 4 degrees C and at laboratory room temperature (18 degrees C-24 degrees C). Results tend to confirm that the presence of humate-type substances seems to have no significant influence on the development of poliomyelitis virus type 1. Moreover, under the experimental conditions used, the survival life of the virus is much longer than the one previously described. It represents an average of 296 days for a storage temperature of 18 degrees C-24 degrees C. It is longer in water kept at 4 degrees C; in fact, according to statistical calculations and to titrations carried out over a period of 550 days, the total disappearance of the virus was detected only after a period of 10 to 15 years.

HeLa Cells↗
PubMedDate not supplied

[Research on coronaviruses in water. I. Adsorption and elution of the coronavirus on glass powder].

The purpose of the research was to determine under what conditions enteric coronaviruses from water can be optimally concentrated by acid-pH adsorption on glass-powder followed by alkaline-pH elution. The 14C labelled bovine enteric coronavirus was grown on HRT18 cell monolayers and purified. Virus adsorption was studied in relation to pH: optimal adsorption yield--between 50 to 75% (mean value: 62%)--was obtained at pH less than or equal to 3.5. Elution was made comparatively with a 0.05 M glycine solution and a 3% beef extract solution. Virus elution occurred mostly at alkaline pH with a maximum yield between 38 and 55% for pH values between 9 and 11. Owing to the sensitivity of coronavirus to acid (pH 3) and alkaline pH (pH greater than or equal to 10), adsorption was optimal at pH 3.3 and elution at pH 9. Under such conditions, the overall efficiency of the method appears to stand between 24 and 28%.

Adsorption↗