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The objective of this study was to deal with the evaluation of 7-(2-(benzylideneamino)-2-(cyclohexa-1,4-dienyl)acetamido)-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid based schiff bases as a new class of enzyme inhibitors. In this connection, a series of Schiff bases of cephradine with substituted aromatic aldehydes was synthesized and characterized using FTIR, 1HNMR and 13CNMR. The in-vitro biological activities including free radical scavenging potential using DPPH assay, acetyl cholinesterase and butyryl cholinesterase inhibition potential were evaluated. Two compounds of the series 1g and 1h were found to be active against AChE whereas no derivative was active against BChE while the whole series showed excellent 1, 1-diphenyl-2-picrylhydrazyl scavenging activity. All the synthesized compounds were found to be non-toxic and present passive gastrointestinal absorption. Furthermore, the study suggests that the synthesized cephradine derivatives exhibit inhibitory potential against different biologically relevant enzyme targets.

Our research investigated the hormesis effect of cefradine on the specific growth rates (μ) of single-celled algae (Chlamydomonas reinhardtii) from aqueous solutions. We found the specific growth rate of C. reinhardtii slightly increased with cefradine concentrations within the range 0.5-10 mg/L. Effects of algae density, initial solution pH, and temperature on the adsorption batch assays were investigated. The optimum conditions for cefradine adsorption occurred at a density of 5 × 10 6 algae cells/mL, a solution pH of 7.0, and a temperature of 25.0 °C. A Box-Behnken design was employed to evaluate correlations between influential factors and cefradine adsorption. The results showed a significant interaction between algae density and temperature. The maximum removal rate could reach 50.13% under the optimal conditions. Additionally, the adsorption mechanisms were explored through Langmuir and Freundlich isotherm equations, adsorption kinetics, and thermodynamics. The results suggested that the adsorption process was monolayer, spontaneous, and endothermic with an increase in randomness at the algae-solution interface, which followed a pseudo-second-order model. All the data indicated that the alga performed a better removal capacity in the antibiotic-containing wastewater treatment process. This study lays the groundwork for a better understanding of the interaction mechanism between cefradine and Chlamydomonas reinhardtii in water solutions under dark condition., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This study was undertaken to investigate drug resistance in Escherichia coli (E. coli) strains isolated from bamboo rats in Zhejiang province of China. One hundred and fifty-four E. coli strains were isolated from dead bamboo rats. Polymerase chain reaction (PCR) was used to detect the representative genes encoding resistance to commonly used β-lactam antibiotics. Highest resistance was observed for cefradine (24.03%), followed by penicillin (20.78%) and ceftazidime (20.13%). The isolation rates of β-lactam resistance genes were 53.25, 48.70, 15.58 and 14.29% for bla TEM , bla CTX-M , bla OXA and bla SHV , respectively, while 62 (40.26%) E. coli isolates harbored multiple β-lactam resistance genes. These results also suggested that long term use of these antibiotics leads to antibimicrobial resistance. We believe that this study will provide a guideline for veterinarians and a research basis for examining resistance-encoding genes in other food animals like bamboo rats.

Antimicrobial resistance (AMR) is a rapidly increasing threat to the effective treatment of infectious diseases worldwide. The two major remedies include: (1) using narrow-spectrum antibiotics based on rapid diagnosis; and (2) developing new antibiotics. A key part of both remedies is the antimicrobial susceptibility test (AST). However, the current standard ASTs that monitor colony formation are costly and time-consuming and the new strategies proposed are not yet practical to be implemented. Herein, we report a strategy to fabricate whole-hydrogel microfluidic chips using alginate-doped agar. This agar-based microfabrication makes it possible to prepare inexpensive hydrogel devices, and allows a seamless link between microfluidics and conventional agar-based cell culture. Different from common microfluidic systems, in our system the cells are cultured on top of the device, similar to normal agar plate culture; on the other hand, the microfluidic channels inside the hydrogel allow precise generation of linear gradient of drugs, thus giving a better performance than the conventional disk diffusion method. Cells in this system are not exposed to any shear flow, which allows the reliable tracking of individual cells and AST results to be obtained within 2-3 hours. Furthermore, our system could test the synergistic effect of drugs through two-dimensional gradient generation. Finally, the platform could be directly implemented to new drug discovery and other applications wherein a fast, cost-efficient method for studying the response of microorganisms upon drug administration is desirable.

Skin inflammation, and skin cancer induced by excessive solar ultraviolet (SUV) is a great threat to human health. SUV induced skin inflammation through activating p38 mitogen-activated protein kinase (p38) and c-Jun N-termeinal kinases (JNKs). T-LAK cell-originated protein kinase (TOPK) plays an important role in this process. Herein, the clinical data showed TOPK, phospho-p38, phospho-JNKs were highly expressed in human solar dermatitis. Ex vivo studies showed that SUV induced the phosphorylation of p38 and JNKs in HaCat and JB6 cells in a dose and time dependent manner. Molecule docking model indicated cefradine, an FDA-approved cephalosporin antibiotic, directly binds with TOPK. The result of in vitro binding assay verified cefradine can directly bind with TOPK. In vitro kinase results showed cefradine can inhibit TOPK activity. Ex vivo studies further showed cefradine inhibited SUV-induced the phosphorylation level of p38, JNKs and H2AX through inhibiting TOPK activity in a dose and time dependent manner, and cefradine inhibited the secretion of IL6 and TNF-α in HaCat and JB6 cells. In vivo studies showed that cefradine down-regulated SUV-induced the phosphorylation of p38, JNKs and H2AX and inhibited the secretion of IL6 and TNF-α in Babl/c mice. These results indicated that cefradine can inhibit SUV-induced skin inflammation by blocking TOPK signaling pathway, and TOPK is an effective target for suppressing inflammation induced by SUV irradiation., Competing Interests: The authors declare no conflicts of interest.

Binary pollution of both heavy metals and antibiotics has received increasing attentions for their joint effects of eco-toxicity and health hazards. To reveal the effects of mixtures of different pollutants on bacterial antioxidant response system, Pseudomonas fluorescens ZY2, a new strain isolated from swine wastewater, was chosen to determinate growth (bacterial density OD600), reactive oxygen species (ROS) concentration, protein concentration and superoxide dismutase (SOD) activity under exposure treatments of Zn, Cefradine or Zn + Cefradine. Bacterial densities of all the treatment groups increased significantly over the incubation time, but those containing pollutant addition were slightly lower than the control at different times of incubation. Both ROS concentration and SOD activity increased first and then decreased (p < 0.01) over time, which was opposite to the protein concentrations (p < 0.01), showing a much significant increase by Cefradine alone. With Zn concentration increasing from 40 to 160 mg/L, the intracellular SOD activity increased as a response to the improvement of ROS (p < 0.05), while the balance between ROS and SOD was broken down due to the disproportionate change of total SOD activity and ROS concentration, the bacterial densities therefore decreased for the weak resistance. With the combined treatment of Zn (200 mg/L) and Cefradine (1 mg/L), though the toxicity of Zn caused a much significant increase of ROS, the bacterial resistance was further improved showing a more significant increase of total SOD activity and the bacterial densities therefore increased bacterial growth. Zn concentration also affected the protein synthesis. Either single or binary stress induced the bacterial resistance by regulating SOD activity to eliminate ROS. All results of the bacterial oxidant stress, SOD response and protein synthesis in the combined treatment groups were more complicated than those in single treatment groups, which depended on the properties of the single treatment as well as the interaction between the two treatments upon bacterial activity. For P. fluorescens ZY2, the mediation of SOD activity to eliminate ROS in response to the combined exposure to Zn and Cefradine was first revealed as one of the co-resistance mechanisms, which is informative to further understanding the risk of antibiotics resistant bacteria to human and environmental health more accurately.

A better understanding on the mechanism involved in bacterial resistance to combined exposure to antibiotics and heavy metals is helpful in implementing practices to mitigate their ecological risk and spread of resistance genes in microbial population. Pseudomonas fluorescens ZY2, a strain isolated from swine wastewater, was chosen to study its growth (bacterial density OD600), the formation of reactive oxygen species (ROS), nitric oxide (NO) and NO synthases (NOS) under Zn, cefradine or Zn + cefradine treatments. Using Zn and cefradine as representative heavy metal and antibiotic in this investigation, respectively, the resistance of P. fluorescens ZY2 to toxic chemical exposure was investigated. Bacterial densities of treatment groups significantly increased over the time of incubation, but less than the control. ROS, NO and NOS initially increased, but then decreased after the initial 8 h of culturing, and were positively related to Zn concentrations. Moreover, the formation of ROS, NOS, and NO was activated by cefradine at Zn of up to 160 mg/L, but inhibited at Zn of 200 mg/L whether cefradine was added or not. Zn concentration affected ROS and NO concentrations between treatments and also was closely related to the variation of the relative bacterial density. For P. fluorescens ZY2, the mediation of endogenous NO to overcome ROS in response to the combined exposure of Zn and cefradine was suggested as a co-resistance mechanism, which would be beneficial to evaluate the ecological risk of heavy metals and antibiotics.

The present work evaluated the combined effects of cefradine and ceftazidime on the green alga Chlorella pyrenoidosa using response surface methodologies (RSM). After a 48 h-exposure, the population growth rate (PGR), the chlorophyll-a content and the SOD content of the alga increased with increased concentrations of two antibiotics. However, the three responses did not continue to demonstrate significant increases once antibiotic concentrations exceed a moderate level. Three two order polynomial regression equations were obtained to describe well the relationship between the responses of the alga and the two antibiotics' concentration (R(2) = 0.9997, 0.9292 and 0.9039, respectively). Three 3 D-surface graphs and their contour plots showed directly the changing trends of the alga under the combined effects of two antibiotics. This study for the first time employed the RSM in ecotoxicology, which indicated that the RSM should be placed under a feasible and a potential application prospect in toxicity assessment., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A Pseudomonas fluorescens strain ZY2, isolated from swine wastewater, was used to investigate the synergistic effects of five heavy metals (Pb, Cu, Zn, Cr(VI) and Hg) on bacterial resistance to antibiotics. Results indicate that the combined effects of antibiotic type, heavy metal type and concentration were significant (p < 0.01). Cross-resistance to Hg and antibiotics was the most noticeable. Moreover, the resistance to Hg and cefradine or amoxicillin, and Cr and amoxicillin were synergistic for low heavy metal concentrations, and turned antagonistic with increasing concentrations, while the resistances to Cr or Cu and cefradine, Pb or Cu and amoxicillin, Cu and norfloxacin showed reverse effects. In addition, resistance to Zn and amoxicillin were always synergetic, while resistance to Pb and cefradine or norfloxacin, Cr or Hg and norfloxacin as well as all the heavy metals and tetracycline were antagonistic. These results indicate that bacterial resistance to antibiotics can be affected by the type and concentration of co-exposed heavy metals and may further threaten people's health and ecological security severely via horizontal gene transfer.

Background: This study attempts to determine the antimicrobial resistance profiles of obligate anaerobic bacteria that were isolated from a periodontal abscess and to evaluate the prevalence of resistance genes in these bacteria., Methods: Forty-one periodontal abscess samples were cultivated on selective and non-selective culture media to isolate the oral anaerobes. Their antibiotic susceptibilities to clindamycin, doxycycline, amoxicillin, imipenem, cefradine, cefixime, roxithromycin, and metronidazole were determined using the agar dilution method, and polymerase chain reaction assays were performed to detect the presence of the ermF, tetQ, nim, and cfxA drug resistance genes., Results: A total of 60 different bacterial colonies was isolated and identified. All of the isolates were sensitive to imipenem. Of the strains, 6.7%, 13.3%, 16.7%, and 25% were resistant to doxycycline, metronidazole, cefixime, and amoxicillin, respectively. The resistance rate for both clindamycin and roxithromycin was 31.7%. Approximately 60.7% of the strains had the ermF gene, and 53.3% of the amoxicillin-resistant strains were found to have the cfxA gene. Two nim genes that were found in eight metronidazole-resistant strains were identified as nimB., Conclusions: In the present study, the Prevotella species are the most frequently isolated obligate anaerobes from periodontal abscesses. The current results show their alarmingly high resistance rate against clindamycin and roxithromycin; thus, the use of these antibiotics is unacceptable for the empirical therapy of periodontal abscesses. A brief prevalence of four resistance genes in the anaerobic bacteria that were isolated was also demonstrated.

The astounding and exceptional growth of generic pharmaceutical Industry in Pakistan has raised certain questions for drug regulatory authorities contemplating their efficacy and quality. The current study focuses on assessing the in-vitro antimicrobial activity of 24 brands of Cephradine 500mg capsules against 4 different strains by employing standardized methods. Disk diffusion method was performed on all brands to look into the susceptibility and resistance patterns. Standard disk of 5µg Cephradine powder were used during evaluation. The zones of inhibitions were ranged from 24-40mm against S. aureus, 24-40mm against E. coli, 20-25mm against K. pneumonia and 19-23mm P. mirabilis. On the basis of mean value, the multinational brands were found to have better zone of inhibitions and were better than local Pharmaceutical companies but ANOVA cooperative study showed that all brands of Cephradine showed similar comparable results. Further investigations by employing MIC method, quality of raw material with special emphasis on the shelf-life, excepients and method of manufacturing will be needed to obtain more authenticated results. The price of National and Multinational brands ranges from Rs.156.00-212.00 for 10 capsules. It is concluded that Public health is at risk because of noticeable growing widespread curse of the manufacture and trade of sub-standard or below par pharmaceuticals. The pecuniary accountability of management of pharmaceutical agents is additionally apparent. The results of the study need to be made public to boost the confidence of medical profession about the quality of locally manufactured pharmaceuticals. It will succour the foreign exchange being incurred on the trade in of medicines.

The effects of cephradinum and ceftazidime on the metabolism of Escherichia coli (E. coli) DH5alpha was determined by microcalorimetry. The microbial activity was recorded as power-time curves through an ampoule method with a TAM Air Isothermal Microcalorimeter at 37 degrees C. The parameters such as the growth rate constant (k), inhibitory ratio (I), the maximum power output (Pm) and the time (tm) corresponding to the maximum power output were calculated. The results show that the ceftazidime has a better inhibitory effect on E. coli DH5alpha than cephradinum.

Intestinal peptide transporters, including hPEPT1, facilitate the absorption of cephalosporins and angiotensin-converting enzyme inhibitors, and have been investigated as a means to improve oral drug absorption. Renal peptide transporters including hPEPT2, may also facilitate renal reabsorption of such compounds. In vitro and animal studies suggest that co-administration of peptidomimetic compounds may alter oral pharmacokinetics, although this has not been well studied in humans. The purpose of this study was to determine whether co-administration of the hPEPT substrates captopril and cephradine alters the oral pharmacokinetics of either agent. Nine healthy male volunteers received a single oral 25-mg dose of captopril, a single oral 500-mg dose of cephradine, or concurrent ingestion of captopril and cephradine in a cross-over manner. Venous blood samples were taken and captopril and cephradine pharmacokinetics were determined using noncompartmental analyses. No significant differences were observed in captopril or cephradine pharmacokinetics when administered together as compared to each agent alone (a marginal decrease in C(max) was observed for both captopril and cephradine during co-administration [5-15%]; however, differences were not statistically significant). The results of our study suggest that hPEPT1 and hPEPT2 are unlikely to contribute to clinically important drug interactions in humans.

Aim: To analyse the characteristics of Streptococcus pyogenes isolates from Chinese children with scarlet fever., Methods: Minimal inhibitory concentration with nine antibiotics was performed on 145 Streptococcus pyogenes isolates acquired from Beijing and Shanghai in 2007. Their macrolide-resistant genes (mefA, ermB and ermA- a subclass of ermTR), superantigens (speA and speC), and en-coding mature M protein gene (emm gene) were amplified by PCR., Results: A total of 97.9% of the isolates exhibited resistance to the macrolides, while 96.6% manifested resistance to tetracycline. All isolates were sensitive to chloramphenicol, penicillin, cefradine, and ofloxacin. Moreover, 94.5% exhibited a cMLSB phenotype, while 90.3% had the ermB gene. Five emm types (emm1.0, emm4.0, emm12.0, emm22.0 and st5240) were discovered, of which 9.7% carried the superantigen speA, 35.9% carried the speC, 42.8% carried both speA and speC and 11.7% carried neither speA nor speC. Finally, 85.5% of emm1.0 and 15.5% of emm12.0 isolates carried speA, while 79.0% of emm1.0 and 75.9% of emm12.0 isolates carried speC., Conclusion: The Streptococcus pyogenes isolates had high resistance rates against macrolides and tetracycline. They mainly expressed the ermB gene type and cMLSB phenotype. Their common emm types are emm1.0 and emm12.0, which have different frequencies of speA and speC.

Cephradine, the first generation cephalosporin, is active against a wide range of Gram-positive and Gram-negative bacteria including penicillinase-producing Staphylococci. Since the presence of complexing ligand may affect the bioavailability of a metal in the blood or tissues, therefore, in order to study the probable interaction of cephradine with essential and trace elements present in human body, cephradine has been reacted with cobalt, copper, zinc and cadmium metal halides in L:M ratio of 2:1 in methanol and the products recrystallized from suitable solvents to pure crystals of consistent melting points. Infrared and ultraviolet studies of these complexes were carried out and compared with ligand. Magnetic susceptibility studies of these complexes were also carried out showing their paramagnetic behavior. From the infra red studies and elemental analysis of the complexes, it has been shown that the drug molecule serves as a bidentate ligand coordinating through both its carboxylate at C-3 and beta-lactam nitrogen and the metal having a square planar or octahedral geometry. To evaluate the changes in microbiological activity of cephradine after complexation, antibacterial studies were carried out by observing the changes in MIC (minimum inhibitory concentration) of the complexes and compared with the parent drug by measuring the zone of inhibition of complexes and compared with the parent cephalosporin against both Gram-positive and Gram-negative organisms. For MIC observation, serial dilution method was employed and zone series were determined by disk diffusion method. Our investigations reveal that formation of complexes results in decrease in antibacterial activity of cephradine and MIC values are increased.

Routine susceptibility data for urinary coliform isolates from community practice were analysed in comparison with dispensed antibiotic prescriptions for all conditions and social deprivation data for Bro Taf and North Wales Health Authorities for financial years 1996--1998. Prescribing rates and resistance rates varied widely between practices. Among isolates from practices with high usage of an antibiotic, rates of resistance to that antibiotic tended to be high, and usage correlated significantly with resistance between practice population units. Cross-correlations were found between usage of one antibiotic and resistance to another, particularly for trimethoprim and ampicillin. Usage, particularly of trimethoprim, was associated with multi-resistance to up to four antibiotics. Resistance was more frequent in isolates from males, children and the elderly. Ampicillin resistance correlated with social deprivation. Analyses including or excluding potential repeat isolates yielded closely similar results. Indices reflecting sampling behaviour (laboratory coliform positivity rates, positivity per 1000 registered patients, specimens submitted per 1000 registered patients) varied widely between surgeries, suggesting lack of consensus on urine sampling policies. These indices showed only weak correlations with usage or resistance. Associations between resistance and usage were compared for isolates from two patient subsets that were likely to differ in their proportions of non-Escherichia coli isolates: female patients aged 16--55 years; and males, children and patients aged >55 years. The latter showed higher base levels of resistance, but the associations of resistance with usage were statistically indistinguishable for the two populations. The results suggest that usage of antibiotics in a practice population may affect the rate of urinary infection caused by resistant coliform organisms in that population.

The physical entrapment of a hydrophilic drug within degradable microspheres is generally difficult because of poor entrapment yield and/or fast release, depending on the microsphere fabrication method. In order to counter the effects of drug hydrophilicity, it is proposed to covalently attach the drug to lactic acid oligomers, with the aim of achieving temporary hydrophobization and slower release controlled by the separation of the drug from the degradable link within the polymer matrix. This strategy was tested on microspheres of the antibiotic cephradin. As the prodrug form, the entrapment of the drug was almost quantitative. The prodrug did degrade in an aqueous medium, modelling body fluids, but cleavage did not occur at the drug-oligomer junction and drug molecules bearing two lactyl residual units were released. When the prodrug is entrapped within a PLAGA matrix, no release was observed within the experimental time period. However, data suggest that conjugation via a bond more sensitive to hydrolysis than the main chain PLA ester bonds should make the system work as desired.

The aim of the study was to determine the influence of certain antibiotics on the production of IFN-gamma by mouse lymphocytes T after four days incubation with Listeria monocytogenes. The level of mouse IFN-gamma was determined by ELISA method (Inter Test-gamma Mouse IFN-gamma Kit, Genzyme). The strongest immunosuppression effect was demonstrated using rifampicin (39 ng/ml IFN-gamma) (Control: 123 +/- 29 ng/ml IFN-gamma, p < 0.05). Lower immunosuppression effects were observed also with cephradine (54 ng/ml IFN-gamma), amikacin (56 ng/ml IFN-gamma) and ticarcillin (83 ng/ml). The obtained results show that all tested cephalosporins (cephamandole, cefotaxime, cephradine) and aminogllycosides (gentamicin, streptomycin, amicacin) inhibit production of IFN-gamma by mouse lymphocytes T. The influence of penicillin G and ampicillin, as well as, erythromycin and lincomycin on the production IFN-gamma was not observed. Our results suggest that rifampicin, ticarcillin, cephalosporins and aminoglycosides act as inhibitors of production IFN-gamma.

MICs of 21 beta-lactams were determined by agar dilution against 283 penicillin-susceptible (pen-S), 122 intermediate (pen-I) and 23 fully penicillin-resistant (pen-R) pneumococci. MICs of all beta-lactams increased with increasing MICs of penicillin. Clometocillin was the most active penicillin against pen-I or pen-R pneumococci. All oral cephalosporins except cefuroxime and cefpodoxime were less active than penicillin and none was satisfactory against pen-I or pen-R pneumococci. The parenteral third- and fourth-generation cephalosporins (except ceftazidime) were similar in activity to penicillin against pen-S isolates. Cefpirome showed the lowest mean MICs against pen-I and pen-R strains.

Oral cephalosporins are frequently prescribed beta-lactam antibiotics. Although it has been well established that cephalosporins compete with dipeptides for absorption in the intestine, using the same transport mechanism, little is known about the action of the drugs on the absorption of other nutrients. In this work the effect of cephradine and cefaclor on the absorption of D-galactose has been studied. Intestinal sugar uptake was measured in-vitro in pieces of intestine (50 mg) and brush-border membrane vesicles, and in-vivo in intestinal loops. Galactose uptake was inhibited by cephalosporins in a dose-related, time-dependent manner. In-vivo the inhibition appeared when the antibiotics were on the luminal side of the enterocyte and when they reached the gut from the basolateral side. Only the active transport of the sugar was modified; passive transfer did not change in the presence of cephalosporins. In brush-border membrane vesicles, cephradine and cefaclor did not alter sugar uptake in either sodium or potassium gradients. Both antibiotics non-competitively inhibited basolateral Na+,K(+)-ATPase activity. These findings show that cephradine and cefaclor inhibit the active-transport component of galactose absorption because they reduce the activity of the basolateral Na+,K(+)-ATPase.

Cephradine was microencapsulated by coacervation. Ethyl cellulose was used as the polymer and a core/wall ratio of 1:1 was selected. The repose angle, apparent and tapped density, particle size distribution of cephradine microcapsules (CM) and of cephradine powder were examined. Then flat-surfaced tablets of CM were prepared using Avicel PH 101 and magnesium stearate. In vitro and in vivo properties of CM and tabletted CM (both equivalent to 150 mg cephradine) were compared with commercial capsules (equivalent to 250 mg cephradine). The dissolution studies were carried out by the rotating basket method and the agar diffusion method was applied for quantitative determinations. Among the investigated kinetic models for the release of cephradine from CM and tabletted CM the best fit was found with the Higuchi model. In vivo studies were made in rabbits. Bioavailabilities of CM and their tabletted form were higher than that of the commercial capsules. In vitro/in vivo correlations between mean residence time (MRT) and mean dissolution time (MDT) for CM and tabletted CM were calculated. A good correlation was found between the in vitro and in vivo results.

The localization and transport characteristics of dipeptide transporters of the intestinal epithelial cell line Caco-2 were examined by measuring the intracellular accumulation and transcellular flux of Bestatin, a dipeptide-like anticancer agent. When added to the apical surface of Caco-2 monolayers grown on microporous membrane filters, Bestatin was accumulated in the cells and was transported unidirectionally to the basolateral side. The cellular uptake of Bestatin from the basolateral as well as from the apical surface was inhibited by excess dipeptides. Bestatin accumulation from the apical surface was dependent on the pH of the incubation medium with an optimal pH of 6.0, whereas uptake from the basolateral surface was insensitive to the medium pH. Kinetic parameters for Bestatin uptake also indicated that the basolateral and apical dipeptide transporters could be distinguished from each other. A sulfhydryl reagent, p-chloromercuribenzene sulfonate, inhibited Bestatin accumulation from both surfaces, although the inhibitory effect on the basolateral transport was greater than that on the apical transport. These findings suggest not only that dipeptide transporters exist on both the apical and basolateral membranes of Caco-2 cells but also that the basolateral dipeptide transporter is distinct from the apical H(+)-dipeptide cotransporter.

The divergence of the obtained results of uric acid determination in patients with proliferative diseases of the haemopoietic system who were given cefradine concomitantly induced the authors to carry out a more profound analysis of that problem. The serum uric acid concentration was determined by two methods. The method with phosphorotungstenic acid showed an effect of cefradine present in samples on overestimation of uricemia, while no such effect was noted when the enzymatic method was used.

The human colon adenocarcinoma cell line Caco-2 retains the H+/dipeptide cotransporter. To identify the structure of the human dipeptide transporter, we have examined the expression of the transporter in Xenopus laevis oocytes injected with Caco-2 poly(A)+RNA, by monitoring the uptake of bestatin, a dipeptide-like anticancer agent. The bestatin uptake in the poly(A)+RNA-injected oocytes was inhibited by excess glycyl-L-leucine, and showed pH dependence (optimal pH of 5.5-6.0). These observations suggest that the human intestinal dipeptide transporter can be expressed functionally in Xenopus oocytes.

Rabbits of group I received cephradine i.m. and of group II lincomycin in mean therapeutic doses (calculated by body weight) for seven days. Determinations were performed before application of antibiotics and at 7, 14, 28 and 42 days of the study. Following tests were performed: phagocytosis index by determination of phagocytizing neutrophils, phagocytosis index and the NBT test. After application of cephradine, each determination revealed significant decrease of percentage of phagocytosing neutrophils, whereas phagocyte index was lowered at 14 day and the NBT value in 14 and 28 days of investigation. After application of lincomycin, value of percentage of phagocytosing neutrophils was lowered at the 14 day, and of phagocytosis index at the 7 day. NBT test values were lowered at 7 and 28 day and increased at the 42 day of the study.

Rabbits were injected intramuscularily with antibiotics in mean therapeutic doses (calculated by body weight) for the period of 7 days. Group I received cephradine, group II--cefuroxime, group III--lincomycin and group IV--amikacin. Determination of complement level by CH50 method was performed before application of antibiotics and at 7, 14, 28 and 42 day of the study. Application of the cephalosporin antibiotics did not result in any changes in the complement level. After application of lincomycin, complement level increased at the 17 day and after amikacin treatment it was higher after 7 days of investigation.

The role of a residue of arginine at the active site of beta-lactamase from Shigella flexneri UCSF-129 was studied. It is a local pathogenic strain which produces intestinal problems, especially in children. Purified enzymes were obtained by affinity chromatography on phenylboronic acid-agarose gels. The enzyme was serine dependent with a molecular weight of 23.6 kD. It was specifically modified with phenylglyoxal (1/830 molar ratio) and incubated for 20 min in the presence of 50 mM sodium phosphate buffer at pH 8.3. The chemical change was established by isoelectric focusing, since a loss of one positive charge was detected. Protection by cephradine, a substrate, indicated the presence of a residue of arginine at its active site. Controls were conducted by differential spectroscopy. Similar results were obtained with 2,3,butanedione. This vital arginine stabilizes the negative charge of the carboxylic group of C-3 or C-4 from the substrates.

Bestatin [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-leucine], a dipeptide containing an unusual amino acid, has been used clinically as an anticancer agent in p.o. dosage form. We examined the transport characteristics of [3H]bestatin by rabbit intestinal brush-border membrane vesicles. Bestatin uptake was stimulated by an inward H+ gradient (overshoot phenomenon) and by an interior-negative membrane potential. About half of the apparent bestatin uptake at 1 mM by brush-border membrane vesicles was estimated as binding to the membranes. The affinity constant for the bestatin transport was 0.52 mM. The uptake of bestatin by brush-border membrane vesicles was inhibited by p.o. cephalosporins and dipeptides, but not by amino acids. In vesicles preloaded with either bestatin, cephradine or glycylsarcosine, the uptake of [3H]bestatin was stimulated markedly (countertransport effect). These results indicate that bestatin is transported via the H+/dipeptide transport system in rabbit intestinal brush-border membranes.

The effect of cefroxadine, an aminocephalosporin (beta lactam antibiotic) on rat intestinal L-leucine transport has been studied. Cefroxadine inhibited the L-leucine uptake by the intestinal mucosa in a dose-dependent fashion. In vivo studies showed that cefroxadine reduced L-leucine absorption. This effect was irreversible. Only the active transport component of the absorption was inhibited. Oxygen consumption of the mucosa was reduced by cefroxadine which inhibited the activity of the basolateral (Na(+)-K+) ATPase also.

The in vitro activity of cefroxadine was studied and found to be at least comparable to that previously reported for cefalexin and cefradine. The activity of cefroxadine was superior to that of amoxicillin against tested isolates. Time-killing studies showed that the addition of 4 X minimum inhibitory concentration (MIC) of cefroxadine to growing cultures reduced viable counts by 4 log units within a 3 h incubation. A diffusion test with a 30 microgram cefroxadine disk produced acceptable interpretive results with tentative zone size breakpoints of less than or equal to 14 mm for resistance and greater than or equal to 17 mm for susceptibility.

6-cephalosporins (cephalothin, cephradine, cephacetrile, cefaclor, cefuroxime, cefotaxime) has been tested in vitro against 212 gram negative bacteria and 60 Staphylococci. Cefuroxime and especially Cefotaxime showed the highest activity against the gram negative bacteria, with a very low MIC. Cefotaxime also acted fairly well against several strains of Pseudomonas. Of the six cephalosporins tested, cephalothin gave the best results against the Staphylococci.

In this study we have evaluated the antibacterial activity of six cephalosporins of the first generation (cephacetrile, cephalothin, cefazolin, cephaloridin, cephalexin, cephradine) two cephalosporin of the second generation (cefoxitin and cefuroxime) and two of the third generation (cefotaxime and cefoperazone) against 66 clinical bacterial isolates. Cefotaxime has been highly active against the strains examined in this study with low MICs.

A double-blind controlled trial of cefroxadine (CXD) 250 mg t.i.d. was undertaken to objectively evaluate its safety and effectiveness in the treatment of acute suppurative otitis media and acute exacerbation of chronic suppurative otitis media, using cephalexin (CEX) 250 mg q.i.d. as a control drug, and the following results were obtained. In the treatment of acute suppurative otitis media, the 2 drugs produced almost equal outcomes, showing no significant difference in assessments of both overall effects and usefulness. In the treatment of acute exacerbation of chronic suppurative otitis media, the 2 drugs exhibited no significant difference as well in overall effects by Wilcoxon's two-sample test. However, the CEX group had significantly more nonresponsive patients, i.e. 35.5% as compared with 9.7% of the CXD group (chi 2-test, P less than 0.05). In the assessment of clinical usefulness as well, no significant difference was observed between the 2 groups. In the assessment of overall effects based on the patients whose isolated organisms were sensitive to the drugs, CEX group had more patients not responding to the treatment of acute exacerbation of chronic suppurative otitis media (chi 2-test, P less than 0.05). Bacteriological effects were not significantly different between the 2 drugs in both acute suppurative otitis media and acute exacerbation of chronic suppurative otitis media. Overall safety rating was not significantly different between the 2 drugs. Side effects occurred as the symptoms of digestive organ in 2 patients each in both groups (equally an incidence of 2.6%). As for the improvement of each symptom after treatment (assessed on day 3), CXD was superior in the improvement rate of otorrhea volume as the main symptom of acute exacerbation of chronic suppurative otitis media, while CEX was superior in that of otoobstruction feeling. From the above findings, it is presumed that CXD is a safe drug which can exhibit equal or superior therapeutic effects to CEX in the treatment of acute suppurative otitis media and acute exacerbation of chronic suppurative otitis media, at 3/4 of the CEX dose level.

Basic and clinical evaluations of a new oral cephalosporin cefroxadine (CXD) in pediatric fields were investigated, and the following results were obtained. 1. MICs of CXD against various bacteria were compared with those of cephalexin (CEX). MIC peaks of CXD against clinically isolated S. aureus (22 strains), S. pyogenes (25), S. pneumoniae (8), H. influenzae (23), and E. coli (23) in pediatric fields, were 1.56, 0.2, 1.56, 25 approximately 50 and 6 .25 microgram/ml, respectively in the inoculum size of 10(8) cells/ml, and they were 1.56, less than 0.1, 0.78, 25 and 6.25 microgram/ml respectively in the inoculum size of 10(6) cells/ml. In comparison with CEX, MIC peaks of CXD against S. aureus, S. pyogenes, H. influenzae and E. coli were almost the same with those of the former, it was, however, better by 1 approximately 2 tubes than that of CEX against S. pneumoniae. 2. CXD in the form of dry syrup was administered orally at a dose of either 10 mg/kg or 20 mg/kg to 5 children, and the serum levels and the urinary excretion were evaluated. In the case of 3 children who were administered a dose of 10 mg/kg the mean serum levels were 11.9 microgram/ml after 30 minutes, 13.7 microgram/ml after 1 hour, 4.7 microgram/ml after 2 hours, 0.7 microgram/ml after 4 hours, and 0.3 microgram/ml after 6 hours, while those 2 children who were administered a dose of 20 mg/kg, they were 15.1, 28.5, 12.5, 2.0 and 0.9 microgram/ml respectively. The mean periods of half-life in serum were 0.87 hour in the case of 10 mg/kg and 0.94 hour in the case of 20 mg/kg. The mean excretion rates were 83.8% in the case of 10 mg/kg and 59.8% in the case 20 mg/kg. 3. CXD dry syrup was administered to 31 children with various bacterial infections i.e. acute pharyngitis (15 cases), acute purulent tonsillitis (10 cases), acute bronchitis (4 cases) and 1 case each of acute pyelonephritis and acute purulent cervical lymphadenitis, and the clinical and bacteriological responses and side effect were investigated. The clinical response was either excellent or good in all of the cases. Out of the S. pyogenes (20 strains), S. aureus (1), S. pneumoniae (2), E. coli (1) and H. influenzae (1), bacteriological eradication was observed in all strains with the exception of 1 strain each in S. pyogenes and H. influenzae in which reduction was observed. No side effects and abnormal laboratory findings were observed.

Cefroxadine (CXD) was studied in the field of obstetrics and gynecology and the following results were obtained. MIC values of CXD against 55 clinical isolates were investigated, from 6.25 to 12.5 micrograms/ml for 8 strains of E. coli, 6.25 micrograms/ml for 3 strains of K. pneumoniae and from 0.39 to 3.13 micrograms/ml for 9 strains of anaerobes such as Peptostreptococcus and Peptococcus in 10(6) cells/ml. Transfer of CXD into intrapelvic organ such as uterus, uterine tube and ovary after the oral administration of 500 mg was investigated. The concentrations in the tissues of genitalia ranged from 5.84 to 7.44 micrograms/g about 2 hours later after the administration. CXD was orally given to 18 patients with infections of genital organs at daily dose of 1,500 mg (500 mg 3 times a day). The clinical response was good, and efficacy rate was 88.9%. No remarkable side effects were observed.

The antibacterial effectiveness of cephalothin, cefazolin, cephacetrile and cephradine was investigated on growing cultures of Klebsiella pneumoniae recording the growth curves with a biophotometer. Thereby cefazolin has a greater antibacterial activity than the other cephalosporins. By raising the dose to 100 microgram/ml after initial bactericidal effect a second growth phase was observed. Phase microscopic observation showed that this was caused by an increasing number of L-forms. This phenomenon could be observed with two other strains and seems to be a strain-specific characteristic. It occurs only using cephalosporins and isotonic nutrient media. The medical importance of the described ability of some bacteria as a factor of pathogenicity is discussed.

Miscellaneous Staphylococcus aureus populations were tested with seven commercialized cephalosporins. The strains were divided in five groups according to the following criteria: penicillinase production or not: sensitivity to methicillin and cephalosporins; RB type resistance to methicillin; RH and RO type resistance to every beta-lactamine (according to Chabbert and Baudens). For each cephalosporin studied, the population cell analysis performed with these different groups showed the constant heterogeneous arrangement of the individual MIC. However, whatever the staphylococcus group, cephaloridine remains the antibiotic that inhibits the largest number of cells at lower concentration than other cephalosporins. In vitro results were compared with pharmacokinetic data of the different cephalosporins.

The activity of cephradine and the influence of pH on its activity against 70 Gardnerella vaginalis strains were determined. Serial dilutions of cephradine (0.062 to 256 micrograms/ml) were incorporated into Dunkelberg agar, inoculated with a Steers replicator, incubated in 5% CO2 for 48 h, and examined. The minimal inhibitory concentrations for 90% of the isolates were 16 and 8.0 micrograms/ml at pH 7.0 to 6.0 and 5.5, respectively.

Cephalosporins are being given more and more frequently empirically as initial therapy, until the bacteriological findings become available. The wide selection of cephalosporins available make the choice of the most suitable one difficult for the clinician. Cephazolin, cephradine and cephacetrile were tested against three standard bacteria strains (Escherichia coli, Staphylococcus aureus, Kelebsiella pneumoniae) in normal broth and with the addition of 30% inactivated human serum; the geometric mean of the minimum inhibitory concentration (MIC) was determined by serial dilution, and the minimum bactericidal concentration (MBC) by inoculation onto solid medium. On the addition of 30% serum, cephazolin showed a reduction in effectivity of up to 360% for the MIC and up to 74% for the MBC, cephacetril up to 250% for the MIC and 100% for the MBC, and cephradin a maximum loss of 16%. Successful treatment of a severe infection requires a high drug level or a corresponding tissue titer. Due to the high tissue concentration of cephradin and the unrivalled stable antibacterial effectivity in serum, this antibiotic can be recommended for clinical use.

Fundamental and clinical studies on cefroxadine (CXD) were carried out, and we have obtained the following results. (1) Sensitivity distribution: As for the sensitivity distribution in S. aureus, the peak was within the ranges from 3.13 to 6.25 microgram/ml in the inoculum size of 10(9) CFU/ml, the distribution was less than or equal to 0.1 to 50 microgram/ml in the inoculum size of 10(6) CFU/ml, with the peak at 1.56 to 6.25 microgram/ml. In S. pyogenes, the sensitivity distribution ranged between less than 0.1 and 1.56 microgram/ml, with the peak at 0.1 microgram/ml in the inoculum size of 10(9) CFU/ml. In the inoculum size of 10(6) CFU/ml, however, the all strains were distributed within the ranges of 0.1 to 0.78 microgram/ml, and the growth of 49 out of 54 strains (91%) was inhibited at less than or equal to 0.1 microgram/ml. In E. coli, the sensitivity peak was at 25 to 50 microgram/ml in the inoculum size of 10(8) CFU/ml, and 5 strains (9.3%) were detected with greater than 100 microgram/ml. Of the 5 strains, 1 strain showed cross tolerance with CEX, the remaining 4 strains was at 50 microgram/ml and at 25 microgram/ml in 2 strains each. In the case of inoculum size of 10(6) CFU/ml, the sensitivity distribution was all within the ranges from 0.78 to 12.5 microgram/ml, except for 1 strain at 100 microgram/ml, with the peak being within the ranges from 3.13 to 12.5 microgram/ml. As for the above 100 microgram/ml-strain, it was showing cross tolerance with CEX. (2) Serum concentration: CXD was administered at a dose level of 10 mg/kg and 20 mg/kg between meals to 5 children, and CXD concentration in their serum was measured. In the group of the 10 mg/kg administration: average 30 minutes value; 8.7 microgram/ml, 1 hour value; 9.15 microgram/ml, 2 hours value; 7.4 microgram/ml, 3 hours value; 2.85 microgram/ml, 4 hours value; 1.0 microgram/ml and 6 hours value; 0.32 microgram/ml, with half-life of 0.88 hours. In the group of the 20 mg/kg administration: average 30 minutes value; 11.7 microgram/ml, 1 hour value; 16.8 microgram/ml, 2 hours value; 10.7 microgram/ml, 3 hours value; 8.15 microgram/ml, 4 hours value; 3.33 microgram/ml, 6 hours value; 1.22 microgram/ml, with half-life of 1.03 hours. A significant interrelation in dose response was observed between the 2 groups. (3) CLINICAL RESULTS: Clinical investigation were held in 29 cases (47 boys and 32 girls). Their diseases comprised of 2 acute pharyngitis, 28 acute purulent tonsillitis, 11 scarlet fever, 3 cervical purulent lymphadenitis, 14 acute bronchitis, 7 acute pneumonia, 11 urinary tract infection and 3 skin soft tissue infection. The drug was effective in 74 out of the 79 cases (93.7%). Causative organism was proved in 60 out of the 79 cases. Fifty-five cases (91.7%) were observed bacterial disappearance or reduction in the 60 cases. Side effects were observed in a total of 3 cases (3.8%), i.e. 2 cases of abnormal values in the laboratory findings (an eosinophilia and/or an elevation of the GPT readings) and 1 case of manifestation of exanthema.

Iodmetric and spectrophotometric methods were developed for the analysis of the new antibiotic cephradine. The procedures are modifications of known methods but are novel in employing a specific beta-lactamase for hydrolysis of the beta-lactam ring of the cephalosporin molecule. The iodometric method is rapid, precise, and accurate, but it requires fairly large amounts of cephradine. The spectrophotometric method, using differential UV absorption at 260 nm, is more rapid and more sensitive than the iodometric method but somewhat less accurate. Both methods proved useful for the routine assay of cephradine in certain formulations.

The effect of cefotaxime and cephradine on the activity of some immune mechanisms was investigated in mice. It was found that cefotaxime in therapeutic doses did not affect the humoral and cellular immune response against sheep erythrocytes, whereas cephradine suppressed the humoral response in doses corresponding to those used for the treatment of patients. The response in vitro of mouse spleen lymphocytes to PHA was suppressed by both cephalosporins; however this occurred at therapeutic concentrations only in the case of cephradine. Neither cephalosporin affected the phagocytic and chemotactic activity of mouse peritoneal macrophages and rabbit microphages.

The cefradine-tobramycine association was used in 11 cases of septicaemia and in 10 cases of non-septicaemic severe poly-infections. In 15 cases, the treatment was undertaken because of the serious state of the patients before the bacteriologic results were known. This association is characterized by its great effectiveness and its very good tolerance, mainly from the renal point of view. The results shown here corroborate those two elements.