The purpose of this paper is to review the development of the mammalian kidney and to assess the influence that various perinatal manipulations may have on the developmental process either morphologically or functionally. Immature kidneys in general have less functional capacity than adult kidneys and a low rate of glomerular filtration, perhaps related to renal blood flow, which appears to limit the disposition of a fluid or solute load. Tubular reabsorption is also limited leading to the urinary loss of glucose, amino acids, bicarbonate and phosphate. Although the relatively low function of the immature kidney is a normal part of development, its capacity to respond under conditions of stress may be less adequate than in adults. An additional concern is that a variety of perinatal manipulations, such as the incidental or accidental ingestion of a chemical, may lead to varying degrees of altered morphogenesis or functional development of the kidney. Chemical induced renal anomalies may be of several types, but in typical teratology experiments hydronephrosis may be the most frequent observation. The functional consequences of these renal malformations may be lethal or inconsequential or while an animal may be able to survive and develop normally in the presence of a renal malformation, it is possible that a stressful situation would unmask a functional malformation which could compromise survival. Thus, some renal abnormalities may be subtle enough to go unnoticed without experimental tests. Without such tests it is impossible to evaluate the effect of functional alterations on successful adaptation. (+info)
A case of canine salmonellosis due to Salmonella infantis.
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A 7-year-old male dog kept outdoors manifested severe watery diarrhea with generalized weakness. Salmonella Infantis was isolated from a fecal sample and the dog recovered soon after medication with ampicillin, to which the isolate was highly sensitive. The present case was diagnosed as S. Infantis infection. Due to the importance of Salmonella in public health, soil samples were collected from the garden where the dog was kept and were examined for Salmonella, Some of them were positive for S. Infantis, however, no Salmonella was isolated from any soil samples collected after thorough disinfection of the surrounded environment. (+info)
Efficacy of ampicillin plus ceftriaxone in treatment of experimental endocarditis due to Enterococcus faecalis strains highly resistant to aminoglycosides.
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The purpose of this work was to evaluate the in vitro possibilities of ampicillin-ceftriaxone combinations for 10 Enterococcus faecalis strains with high-level resistance to aminoglycosides (HLRAg) and to assess the efficacy of ampicillin plus ceftriaxone, both administered with humanlike pharmacokinetics, for the treatment of experimental endocarditis due to HLRAg E. faecalis. A reduction of 1 to 4 dilutions in MICs of ampicillin was obtained when ampicillin was combined with a fixed subinhibitory ceftriaxone concentration of 4 micrograms/ml. This potentiating effect was also observed by the double disk method with all 10 strains. Time-kill studies performed with 1 and 2 micrograms of ampicillin alone per ml or in combination with 5, 10, 20, 40, and 60 micrograms of ceftriaxone per ml showed a > or = 2 log10 reduction in CFU per milliliter with respect to ampicillin alone and to the initial inoculum for all 10 E. faecalis strains studied. This effect was obtained for seven strains with the combination of 2 micrograms of ampicillin per ml plus 10 micrograms of ceftriaxone per ml and for six strains with 5 micrograms of ceftriaxone per ml. Animals with catheter-induced endocarditis were infected intravenously with 10(8) CFU of E. faecalis V48 or 10(5) CFU of E. faecalis V45 and were treated for 3 days with humanlike pharmacokinetics of 2 g of ampicillin every 4 h, alone or combined with 2 g of ceftriaxone every 12 h. The levels in serum and the pharmacokinetic parameters of the humanlike pharmacokinetics of ampicillin or ceftriaxone in rabbits were similar to those found in humans treated with 2 g of ampicillin or ceftriaxone intravenously. Results of the therapy for experimental endocarditis caused by E. faecalis V48 or V45 showed that the residual bacterial titers in aortic valve vegetations were significantly lower in the animals treated with the combinations of ampicillin plus ceftriaxone than in those treated with ampicillin alone (P < 0.001). The combination of ampicillin and ceftriaxone showed in vitro and in vivo synergism against HLRAg E. faecalis. (+info)
Pharmacodynamic comparisons of levofloxacin, ciprofloxacin, and ampicillin against Streptococcus pneumoniae in an in vitro model of infection.
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The increasing frequency of penicillin-resistant pneumococcus continues to be of concern throughout the world. Newer fluoroquinolone antibiotics, such as levofloxacin, have shown enhanced in vitro activity against Streptococcus pneumoniae. In this study, the bactericidal characteristics and pharmacodynamic profiles of levofloxacin, ciprofloxacin, and ampicillin against four isolates of S. pneumoniae were compared by using an in vitro model of infection. Standard antibiotic dosing regimens which simulated the pharmacokinetic profile observed in humans were used. Control and treatment models were sampled for bacterial CFU per milliliter over the duration of each 24- or 48-h experiment. In addition, treatment models were sampled for MIC determinations and drug concentration. Regrowth of all isolates as well as an increase in MICs throughout the study period was observed in the ciprofloxacin experiments. A limited amount of regrowth was noted during levofloxacin therapy for one isolate; however, no change in MIC was detected for any isolate. Ampicillin showed rapid and sustained bactericidal activity against all isolates. In this study, ratios of effective fluoroquinolone area under the concentration-time curve (AUC):MIC values ranged from 30 to 55. Levofloxacin, owing to its larger AUC0-24 values, has excellent and sustained activity against different pneumococcal strains superior to that of ciprofloxacin. (+info)
Organization of the gene cluster for biosynthesis of penicillin in Penicillium nalgiovense and antibiotic production in cured dry sausages.
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Several fungal isolates obtained from two cured meat products from Spain were identified as Penicillium nalgiovense by their morphological features and by DNA fingerprinting. All P. nalgiovense isolates showed antibiotic activity in agar diffusion assays, and their penicillin production in liquid complex medium ranged from 6 to 38 microgram. ml-1. We constructed a restriction map of the penicillin gene cluster of P. nalgiovense and found that the organization of the penicillin biosynthetic genes (pcbAB, pcbC, and penDE) is the same as in Penicillium chrysogenum and Aspergillus nidulans. The pcbAB gene is located in an orientation opposite that of the pcbC and penDE genes in all three species. Significant amounts of penicillin were found in situ in the casing and the outer layer of salami meat during early stages of the curing process, coinciding with fungal colonization, but no penicillin was detected in the cured salami. The antibiotic produced in situ was sensitive to penicillinase. (+info)
Pneumococcal psoas abscess.
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A 47-year-old woman was admitted to our hospital because of severe low back pain. A computed tomography (CT) scan revealed a left sided psoas muscle abscess. On the first hospital day, US-guided drainage was performed. Streptococcus pneumoniae was isolated from the pus. Thereafter, the open drainage of the abscess and antibiotic treatment were given with subsequent clinical improvement. Only 10 cases of pneumococcal psoas abscess have been previously reported in the world literature. (+info)
Determination of free interstitial concentrations of piperacillin-tazobactam combinations by microdialysis.
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The investigation of tissue penetration and distribution of antibiotics is of great importance, since infections occur mostly in the tissues. The aim of this study was to investigate the pharmacokinetics of piperacillin and tazobactam, alone and in combination, by measuring total plasma and free interstitial concentrations, and to examine the relationship between free levels of both drugs in blood and those in the extracellular space. Piperacillin and tazobactam were administered, alone and in combination, to anaesthetized rats as a single iv bolus dose. Total plasma concentrations and free extracellular concentrations were quantified by HPLC. In-vivo microdialysis sampling was used to study the free tissue distribution patterns of both drugs. The pharmacokinetics of piperacillin and tazobactam in plasma were consistent with a two-compartment body model. Piperacillin pharmacokinetics were not influenced by co-administration of tazobactam. Tazobactam's volumes of distribution and clearance were decreased by the co-administration of piperacillin and the area under the curve was significantly increased. Comparisons between calculated free concentrations in the peripheral compartment for both drugs and measured free extracellular concentrations revealed excellent agreement. For piperacillin and tazobactam, alone and in combination, predictions of the concentration-time profiles of free drug in the peripheral compartment can be made on the basis of plasma data. (+info)
Case of sepsis caused by Bifidobacterium longum.
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We report a case of sepsis caused by Bifidobacterium longum in a 19-year-old male who had developed high fever, jaundice, and hepatomegaly after acupuncture therapy with small gold needles. Anaerobic, non-spore-forming, gram-positive bacilli were isolated from his blood and finally identified as B. longum. He recovered completely after treatment with ticarcillin and metronidazole. To our knowledge, this is the first report of incidental sepsis caused by B. longum. (+info)