摘要:

To study the behavior of antibiotics in the tissues, rats were sacrificed repeatedly in groups of six, after the injection of 25 mg/kg ampicillin, 100 mg/kg cephalothin or 10 mg/kg doxycycline. These antibiotics were bioassayed in ten different organs. Standards were established for each organ by using identical organs, thus avoiding errors caused by tissue binding or inhibition. Penetration into the tissue is very fast. Compared to serum levels, lung, muscle, heart, testicle and spleen, levels are higher for doycycline, lower for ampicillin and variable for cephalothin: for example, lung/serum ratio at 1 h is 2.2, 0.5 and 1.1, respectively; muscle/serum is 2.3, 0.2 and 0.18. The decrease in tissue levels parallels that in the serum for doxycycline, but is slower for ampicillin. The hepatic penetration of cephalothin is less than that of doxycycline or ampicillin. Levels are higher in the renal cortex than in the medulla for doxycycline, lower for cephalothin, and similar for ampicillin. The data enabled calculation of tissular pharmacokinetics. They have practical implications in the selection of antibiotics.

ISSN:0009-3157    

DOI:10.1159/000221981

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The recovery rate of gentamicin and tobramycin from uraemic sera was between 50 and 70% using a bioassay method which gave a 90% recovery rate from normal sera. This difference was not seen with streptomycin or kanamycin. The recovery rate from uraemic sera could be raised to clinically acceptable levels of above 80% either by using a different assay medium or by preparing standard solutions in pooled uraemic sera.

ISSN:0009-3157    

DOI:10.1159/000221982

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Dipyridamole showed an antiviral activity against mengovirus in FL cells using the agar diffusion plaque inhibition test, plaque reduction test, tube titra-tion test, and virus yield test after one replication cycle. With the last two tests mentioned aboye the inhibitory action was also confirmed in L cells. In consequence of the known transport inhibition of uridine into the cell in presence of dipyridamole only a very small incorporation of 3H-uridine into acid-insoluble material could be demonstrated. Applying the method of prelabelling of FL cells at 16°C for 1 h with subsequent addition of dipyridamole the drug failed to show an effect on cellular RNA synthesis per se in uninfected cells whereas the viral RNA synthesis in mengo-virus-infected L cells was completely depressed

ISSN:0009-3157    

DOI:10.1159/000221983

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The validity of nonsimultaneous association of penicillinase-sensitive β-lactam antibiotics with halogenated isoxazolylpenicillins was tested in various Enterobacteriaceae strains. With several bacterial strains, expecially if producers of β-lactamase type IV, exposure of either the bacterial suspensions of the broth supernatant to the isoxazolylpenicillins appears both in vivo and in vitro to reduce the extent of subsequent hydrolysis of penicillinase-sensitive β-lactam antibioti

ISSN:0009-3157    

DOI:10.1159/000221984

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Morphometric parameters of mitochondria such as volumetric density, surface density of envelopes and cristae and numerical density were calculated for control untreated and triacetyloleandomycin (TAO)-treated rat hepatocytes using a point-counting technique. Moreover, morphometric parameters calculated experimentally and those computed on the basis of the least square interpolation and the agreement with the χ2 test, were compared. The equations modelling each main morphometric parameter of experimental mitochondria were also computed. Morphometric study revealed that TAO produces a highly reproducible pattern of morphological alterations in the mitochondrial population of rat hepatocytes, and a good agreement between experimental and theoretical data was found. The response of hepatocyte mitochondria to TAO may be modelled by parabolic functions described by equations of the second degree. During the whole experimental period, the number of mitochondria decreases, but the specific volume of mitochondria increases. The area of the cristae surface per mitochondrion does not change substantially during the whole experimental period but since the quantity of internal mitochondrial membranes per hepatocyte is less in the later experimental period than in control material, it can be assumed that the oxidizing capacity per hepatocyte has diminished. The morphometric model based on TAO-treated hepatocyte mitochondria is different from those so far described in the literature for rat liver

ISSN:0009-3157    

DOI:10.1159/000221985

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Rates of reduction in viability and degree of cell killing were relatively independent of concentrations when replicating cultured L1210 cells were exposed to increasing concentrations of 6-thioguanine, 6-methylthiopurine ribonucleoside, 9-β-D-arabinofuranosyl-9H-purine-6-thiol, or 9-ethyl-6-thiopurine. The relative lack of dependence of cell killing rate on cytotoxic concentrations suggest (a) that these agents may be only effective against proliferating cells, and (b) that only limited therapeutic advantage can be gainged by increasing their concentration beyond a minimum effective level. In contrast, the rate and degree of cell killing were dependent upon concentrations when cells were exposed to increasing amounts of 4-aminopyrrolo(2,3-d)pyrimidine-β-D-ribofuranoside or to 2-fluoroadenosine, indicating that these analogs are not cell-cycle-stage-specific and that nonreplicating cell populations may be sensitive to the

ISSN:0009-3157    

DOI:10.1159/000221986

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The present stage of our studies suggests that, provided a highly effective combined therapy is, and can be, carried out correctly, all excreters can be cured of their chronic carrier state by chemotherapy within 8–12 weeks. Although we cannot recommend a universal therapeutic regimen for all patients, a highly effective ‘basic therapy’ (RMP+TSP) is available for the majority of the cases, needing occasional modification, depending on the specific requirements of the individual patient as shown by the result of the serum activity determination. This method saves the patient from toxic inconveniences caused by inadequate treatment, it shortens the treatment time and makes cholecystectomy superfluous – unless it is considered necessary out of a different indication in which case it should certainly be done. We cannot share the often expressed view that Salmonella enteritidis excreters cannot be cured, a view which is found even in the most recent manuals. The same applies to the view that therapy is not necessary because it would delay cure. It is indispensable to establish a close cooperation between the public health authorities and the private physician, and we therefore wish to sincerely thank all colleagues and Public Health Officers for their collab

ISSN:0009-3157    

DOI:10.1159/000221987

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0009-3157    

DOI:10.1159/000221988

出版商:S. Karger AG    

年代:1977

数据来源: Karger