The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Minimum standards of pelvic exenterative practice: PelvEx Collaborative guideline

This document outlines the important aspects of caring for patients who have been diagnosed with advanced pelvic cancer. It is primarily aimed at those who are establishing a service that adequately caters to this patient group. The relevant literature has been summarized and an attempt made to simplify the approach to management of these complex cases.

Simultaneous pelvic exenteration and liver resection for primary rectal cancer with synchronous liver metastases: results from the PelvEx Collaborative

AIM

At presentation, 15-20% of patients with rectal cancer already have synchronous liver metastases. The aim of this study was to determine the surgical and survival outcomes in patients with advanced rectal cancer who underwent combined pelvic exenteration and liver (oligometastatic) resection.

METHOD

Data from 20 international institutions that performed simultaneous pelvic exenteration and liver resection between 2007 and 2017 were accumulated. Primarily, we examined perioperative outcomes, morbidity and mortality. We also assessed the impact that margin status had on survival.

RESULTS

Of 128 patients, 72 (56.2%) were men with a median age of 60 years [interquartile range (IQR) 15 years]. The median size of the liver oligometastatic deposits was 2 cm (IQR 1.8 cm). The median duration of surgery was 406 min (IQR 240 min), with a median blood loss of 1090 ml (IQR 2010 ml). A negative resection margin (R0 resection) was achieved in 73.5% of pelvic exenterations and 66.4% of liver resections. The 30-day mortality rate was 1.6%, and 32% of patients had a major postoperative complication. The 5-year overall survival for patients in whom an R0 resection of both primary and metastatic disease was achieved was 54.6% compared with 20% for those with an R1/R2 resection (P = 0.006).

CONCLUSION

Simultaneous pelvic exenteration and liver resection is feasible, with acceptable morbidity and mortality. Simultaneous resection should only be performed where an R0 resection of both pelvic and hepatic disease is anticipated.

Colorectal anastomosis after laparoscopic low anterior resection with total mesorectal excision: a difficult problem made simple

Laparoscopic anterior resection with total mesorectal excision for middle and lower third rectal cancer remains a difficult operation, in particular, in male patients with a narrow pelvis and bulky mesentery. In this type of patient, the available staplers do not allow an easy transection of the rectum close to the pelvic floor. A new approach that uses instruments (dilator, obturator, and pursestring anoscope) specifically designed for the technique of stapled hemorrhoidopexy and a common circular stapler can overcome all these issues.

Does the new TNM classification (1997) improve prognostic stratification in gastric cancer submitted to R0 surgery?

AIMS

To determine the eventual advantage of the new 1997 TNM as prognosis predictor for gastric cancer patients submitted to an R0 resection and to compare it with two other lymph-node involvement classifications, the 1990 TNM and the Okusa system.

METHODS

From January 1980 to December 1995, an R0 resection was performed as primary therapy in 275 cases of gastric cancer. These operations consisted of a total or sub-total gastrectomy and of a D2 type lymph-node dissection. Tumour classification was performed according to 1990 and 1997 TNM systems, and to the Okusa lymph node classification. The statistical methods used to evaluate prognostic value were: Kaplan-Meier survival estimates; the log-rank test for univariate analysis; and Cox's model for multivariate analysis.

RESULTS

The 1990 TNM showed the best stratification power in univariate analysis. In multivariate analysis, the Okusa classification was identified as the best prognostic index (P<0.01). The 1997 TNM showed worse stratification capability than the two other systems.

CONCLUSIONS

In the present series, the new TNM (1997) did not improve the prognostic stratification of lymph-node involvement. An adequate and universal system for lymph-node stratification is necessary and further validation of these classifications is needed.

Chemotherapeutic activity of levofloxacin (HR 355, DR-3355) against systemic and localized infections in laboratory animals

Ofloxacin, its optical isomers levofloxacin (HR 355, DR-3355) and D-ofloxacin (DR-3354) and ciprofloxacin were administered orally to mice and rats which had systemic and localized infections. Both levofloxacin and ciprofloxacin were equally effective in treating systemic murine infections caused by staphylococci. Enterobacteriaceae or Pseudomonas aeruginosa with ED50s ranging from 0.18 to 15.8 mg/kg and 0.42 to 16.3 mg/kg respectively and both these agents were twice as effective as ofloxacin which had an ED50 0.41 to 39.7 mg/kg. In contrast, D-ofloxacin was either inactive or exhibited only modest chemotherapeutic activity against the staphylococci and the Gram-negative organisms tested. When given to mice to treat staphylococcal abscesses and lung infections due to Klebsiella pneumoniae DT-S levofloxacin was up to four times more effective and produced a more pronounced bactericidal effect against the pathogens in vivo than the reference compounds. Despite possessing a similar, if not lesser, in-vitro activity against the infecting pathogens, levofloxacin was more effective than ofloxacin and ciprofloxacin in rats with localized infections caused by Enterobacteriaceae and P. aeruginosa.

Balhimycin, a new glycopeptide antibiotic produced by Amycolatopsis sp. Y-86,21022. Taxonomy, production, isolation and biological activity

A new glycopeptide antibiotic, balhimycin, has been isolated from the fermentation broth of a Amycolatopsis sp. Y-86,21022. Balhimycin belongs to the vancomycin class of glycopeptides and contains a dehydrovancosamine sugar. The biological activity of balhimycin has been compared extensively with that of vancomycin against methicillin resistant staphylococci and also against anaerobes. Balhimycin is marginally superior to vancomycin in its in vitro activity against anaerobes and in its bactericidal properties.

Mersacidin, a new antibiotic from Bacillus. In vitro and in vivo antibacterial activity

Mersacidin is a new peptide antibiotic of the proposed lantibiotic family. It is active in vitro and in vivo against Gram-positive bacteria including the methicillin-resistant Staphylococci. Its in vitro activity is less than those of vancomycin and erythromycin but it shows much higher activity in the in vivo system than can be expected from the in vitro testing results. A water soluble potassium salt has been prepared which has an activity profile similar to that of mersacidin, but has better in vivo activity against Streptococcus pyogenes than the parent compound.

RU 29 246, the active compound of the cephalosporin prodrug-ester HR 916. III. Pharmacokinetic properties and antibacterial activity in vivo

The pharmacokinetics of the broad spectrum cephem RU 29 246 and its prodrug-ester HR 916 B were investigated in mice, rats and dogs and compared to those of cefpodoxime proxetil, cefuroxime axetil and cefixime. HR 916 B is well absorbed following oral administration and efficiently converted to the antibacterially active form. In mice, mean peak blood levels of 31.1 micrograms/ml of the parent compound were recorded within 20 minutes after oral administration of a single dose equivalent to 40 mg/kg RU 29 246. The bioavailability calculated on the basis of the areas under the concentration-time curves (AUC) and the urinary recoveries was about 90%. In rats, peak blood levels of 14.5 micrograms/ml were obtained 1 hour after an oral 20 mg/kg dose. The bioavailability was calculated as 70%. In dogs, 40% of an oral 10 mg/kg dose was recovered in the urine within 24 hours. Cmax was 15.9 micrograms/ml at 4.6 hours. Mean elimination half-lives of RU 29 246 were 0.35, 0.5 and 2.1 hours in mice, rats and dogs, respectively. After an oral HR 916 B dose equivalent to 50 mg/kg of RU 29 246, tissue concentrations at 0.5 hour ranged between 0.8 micrograms/g in brain and 95.7 micrograms/g in murine kidneys. These values of HR 916 B are similar to, or distinctly higher than, those of the reference compounds. Of the oral cephalosporins tested, HR 916 B had the most balanced antibacterial spectrum. With ED50s of between 0.9 and 11.5 mg/kg against staphylococci, its activity was similar to that of the additional reference compound cefaclor and higher than that of cefuroxime. Cefixime and cefpodoxime proxetil displayed low antistaphylococcal activity or were inactive. In septicemias with Enterobacteriaceae, cefixime and cefpodoxime proxetil were more potent than HR 916 B and cefaclor. Cefuroxime axetil was inactive against most of these infections. HR 916 B was also highly effective against murine lung infections caused by Klebsiella pneumoniae DT-S or Streptococcus pneumoniae 1147.

Antibacterial activity in vitro of cefpirome against clinical isolates causing sexually transmitted diseases

The in-vitro activity of cefpirome was compared with other antibiotics against organisms causing sexually transmitted diseases (STD). The excellent activity of cefpirome against Neisseria gonorrhoeae (MIC90 1.0 mg/L), Haemophilus ducreyi (MIC90 0.5 mg/L), and Gardnerella vaginalis (MIC90 1.0 mg/L) suggests that this agent might be useful in the empirical treatment of a variety of venereal diseases.

Pharmacokinetics of cefpirome administered intravenously or intramuscularly to rats and dogs

The pharmacokinetic profile of cefpirome was evaluated in rats and dogs after a single intravenous or intramuscular dose. A two-compartment open model was used for the calculation of the pharmacokinetic parameters for both routes of administration. The elimination half-lives after intravenous and intramuscular administration of 20 mg/kg cefpirome did not differ significantly and ranged from 0.4 h in rats to 1.1 h in dogs. Cefpirome was mainly excreted via the kidneys. After iv or im dosing of the compound, between 80% (dogs) and 90% (rats) was recovered in urine within 24 h. The bioavailability of cefpirome in rats and dogs after both routes of administration was almost identical when calculated either by the AUC or the urinary recovery rates.

The in-vitro antibacterial activity of a combination of cefpirome or cefoperazone with vancomycin against enterococci and Staphylococcus aureus

Cefpirome, cefoperazone and ceftazidime were tested for their in-vitro activity against Enterococcus faecalis and methicillin-resistant Staphylococcus aureus (MRSA) isolates. Cefpirome was the most active cephalosporin followed by cefoperazone. Ceftazidime had only very limited activity against these strains. In experiments with cefpirome/vancomycin and cefoperazone/vancomycin combinations, synergy was detected against most MRSA strains and some enterococci. Antagonism did not occur.

RU 29 246, the active compound of the cephalosporin-prodrug-ester HR 916. I. Antibacterial activity in vitro

The aminothiazolyl-cephalosporin RU 29 246 is the active metabolite of the prodrug-pivaloyl-oxyethyl-ester HR 916. RU 29 246 in vitro activity includes a wide range of clinically relevant bacterial pathogens. Against methicillin-sensitive Staphylococci RU 29 246 (MIC90 of 0.25 approximately 2 micrograms/ml) was clearly more active than cefaclor, cefuroxime, cefpodoxime, cefixime and ceftibuten, but slightly less active than cefdinir. RU 29 246 inhibited hemolytic Streptococci of the serogroups A, B, C and G as well as penicillin-sensitive Streptococcus pneumoniae at concentrations similar to cefdinir, cefpodoxime and cefuroxime (MIC90 less than or equal to 0.13 micrograms/ml), but less than the other oral cephalosporins investigated (cefixime, cefaclor and ceftibuten). MIC90s of RU 29 246 against Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Salmonella spp., Shigella spp., Proteus mirabilis and Haemophilus influenzae were less than or equal to 0.5 micrograms/ml. Only RU 29 246 and cefdinir demonstrated moderate activity against Acinetobacter baumannii (MIC90 greater than or equal to 4 micrograms/ml). Most strains of Pseudomonas spp., Serratia marcescens, Enterobacter spp., Hafnia alvei and Bacteroides spp. were resistant to RU 29 246. RU 29 246 killed Escherichia coli and Staphylococcus aureus at a rate of 99% to 99.9% at concentrations of two times MIC. The pH value of the medium (range 5.5 to 8.5) and the inoculum size (range 10(5) to 10(7) cfu/ml) had no or only low influence on the antibacterial activity of RU 29 246. RU 29 246 is a broad spectrum cephalosporin including in its activity both Gram-positive and Gram-negative pathogens and therefore--depending on the bioavailability of its prodrug--looks promising as to its therapeutic perspective.

RU 29 246, the active compound of the cephalosporin-prodrug-ester HR 916. II. Stability to beta-lactamases and affinity for penicillin-binding proteins

The aminothiazolyl-cephalosporin RU 29 246, the active metabolite of the prodrug-ester HR 916, is active against strains producing the widespread plasmid-encoded TEM-1, TEM-2 and SHV-1 beta-lactamases. Except for TEM-7 the activity of RU 29 246 against strains producing extended broad spectrum beta-lactamases (TEM-3, TEM-5, TEM-6, SHV-2, SHV-4, SHV-5, CMY-1, CTX-M), however, is low. Relative hydrolysis rates of RU 29 246 are comparable with those of cefpodoxime, the active metabolite of CS-807, and are extremely low for the TEM-1 and SHV-1 beta-lactamases. The compound demonstrates remarkable inhibitory activity against the chromosomal beta-lactamase of Enterobacter cloacae P99. In the presence of 1.7 microM this enzyme loses 50% of its activity. At concentrations of 0.43, 0.003 and 0.01 micrograms/ml the compound binds preferentially to the penicillin-binding protein (PBP) 3 of Escherichia coli K12, to the PBPs 2x and 3 of Streptococcus pneumoniae R6 and to PBP 1 of Staphylococcus aureus SG 511, respectively.

Influence of cefodizime on the reagibility of human leukocytes

Cefodizime was evaluated for its effect on a number of parameters of leukocyte function in humans. Four healthy volunteers received 2 g i.v. b.i.d. for seven days. Leukocyte activity was measured before, during and after treatment. Using opsonized zymosan as a stimulant, no effect on the respiratory burst of granulocytes was observed. It was found, however, that the lymphocytes in three of the four subjects showed significantly more marked proliferation rates in the mixed lymphocyte reaction after administration of cefodizime than at baseline. The stimulation indices subsequently returned to normal. This pilot study therefore demonstrated that cefodizime has biological response modifying properties in healthy humans.

Antibacterial activities in vitro and in vivo and pharmacokinetics of cefquinome (HR 111V), a new broad-spectrum cephalosporin

Cefquinome is a new injectable aminothiazolyl cephalosporin derivative. It is stable against chromosomally and plasmid-encoded beta-lactamases and has a broad antibacterial spectrum. Staphylococcus aureus, streptococci, Pseudomonas aeruginosa, and members of the family Enterobacteriaceae (Escherichia coli, Salmonella spp., Klebsiella spp., Enterobacter spp., Citrobacter spp., and Serratia marcescens) are inhibited at low concentrations. Cefquinome is also active against many strains of methicillin-resistant staphylococci and enterococci. Its in vitro activity against gram-negative anaerobes is very limited. The high in vitro activity of cefquinome is reflected by its high in vivo efficacy against experimental septicemia due to different gram-positive and gram-negative bacteria. We studied the pharmacokinetic properties of cefquinome in mice, dogs, pigs, and calves. After single parenteral administrations, cefquinome displayed high peak levels, declining with half-lives of about 0.5, 0.9, 1.2, and 1.3 h, respectively. The areas under the concentration-time curve determined for dogs and mice showed linear correlations to the given doses. In dogs the urinary recovery was more than 70% within 24 h of dosing.

Comparative chemotherapeutic activity of cefpirome and imipenem in experimental infections

In systemic and local infections, the therapeutic efficacy of cefpirome was compared to that of imipenem and cefotaxime. Murine septicemia induced with methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains responded well to cefpirome and imipenem therapy, the ED50 values ranged from 0.8 to 28.40 mg/kg and 0.5 to 15.58 mg/kg, respectively. The carbapenem also displayed high efficacy against Enterococci and was more potent than cefpirome. Cefotaxime, however, exhibited lower activity or proved to be inactive against these strains. With ED50 values of 0.03 to 31.33 mg/kg, cefpirome was the most active of the three antibiotics in protecting mice challenged with Enterobacteriaceae. The corresponding ED50 values of imipenem and cefotaxime ranged from 0.72 to 70.95 mg/kg and 0.06 to 66.30 mg/kg, respectively. Despite distinctly lower in vitro activity against the infecting organism, cefpirome showed efficacy similar to imipenem in the treatment of subcutaneous S. aureus abscesses in mice. It was more effective than imipenem and cefotaxime against experimental Klebsiella pneumonia in mice and the Escherichia coli infected granuloma pouch in rats.

Synthesis and structure-activity relationships in the cefpirome series. III. 7 Alpha-methoxy and 7 alpha-formamido analogues of cefpirome

7 alpha-Methoxy and 7 alpha-formamido derivatives of cefpirome (HR 810) have been synthesized and tested in comparison with cefpirome and some analogues 1 against aerobic and anaerobic bacteria. Cefpirome and analogues 1 have good activity against Gram-positive and only limited activity against Gram-negative anaerobic bacteria. 7 alpha-Methoxy derivatives 2 show only a slight improvement of activity against Gram-negative anaerobes and are less active against all aerobes. Introduction of the 7 alpha-formamido group (compounds 3) results in an overall loss of activity towards both aerobic and anaerobic bacteria.

The in vitro activity of the combination of cefotaxime and HRE 664

Cefotaxime (CTX) and HRE 664 (a novel penem antibiotic) possess complementary in vitro properties. Differences can be observed in their antibacterial spectra, their beta-lactamase stability and -inhibition, and their affinity to penicillin-binding proteins. These differences suggested that combinations of the cephalosporin and the penem antibiotic would be advantageous and should be studied. The fractional inhibitory concentration values of checkerboard studies confirmed that CTX and HRE 664 act synergistically against various Gram-positive and Gram-negative bacteria. Fixed combinations containing 80% CTX and 20% HRE 664 possess broader antibacterial spectra and in certain cases higher antibacterial activities than each of the components alone. The combinations had improved activity against Staphylococci including methicillin-resistant strains, beta-lactamase producing strains of Enterobacter sp. and Bacteroides fragilis. The combination as well as the single antibiotics had only limited activity against Pseudomonas aeruginosa.

HRE 664, a new parenteral penem. II. Evaluation of the pharmacokinetic behavior and the chemotherapeutic activity in animals

The pharmacokinetic and chemotherapeutic properties of the new penem antibiotic HRE 664 (Fig. 1) were evaluated in experimental animals. High and sustained blood and serum levels were achieved following parenteral injection in mice, rats, dogs and monkeys. Half-lives ranged from 27 to 40 minutes in the various species tested. The antibiotic was well distributed in the rodents and penetrated well into tissues and body fluids. At 30 minutes after subcutaneous administration to mice (50 mg/kg), concentrations of between 12.4 and 35.9 micrograms/g were measured in the lungs, liver, heart and kidneys, that is 33 approximately 95% of the corresponding level in murine blood (37.7 micrograms/ml). In experimentally induced infections in mice, HRE 664 displayed good chemotherapeutic activity particularly against septicemias caused by methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains and on abscess formation induced by Bacteroides fragilis. Most of the cephalosporins and other beta-lactam antibiotics exhibited low efficacy against these strains of bacteria.

HRE 664, a new parenteral penem. I. Antibacterial activity in vitro

The new penem antibiotic HRE 664 displays potent antibacterial activity in vitro against a broad spectrum of clinically relevant bacterial strains including Gram-negative and Gram-positive aerobes and anaerobes. With an MIC 90% of 0.43 micrograms/ml, it is also active against methicillin-resistant staphylococci. HRE 664 is extremely stable against beta-lactamases, it binds preferentially to the penicillin-binding proteins 2, 3, 5 and 6 of Escherichia coli.

Cefodizime, an aminothiazolylcephalosporin. V. Synthesis and structure-activity relationships in the cefodizime series

The synthesis as well as in vitro antibacterial activity and pharmacokinetic behavior of cefodizime (HR 221, 1a), its analogs and derivatives is described. In this comparison, cefodizime stands out for its balance between its high antibacterial activity, prolonged elimination half-life and high AUC in mice and dogs.

Comparative effects of cefpirome (HR 810) and other cephalosporins on experimentally induced pneumonia in mice

The chemotherapeutic efficacy of cefpirome (HR 810), a new polar aminothiazolylcephalosporin and that of ceftazidime, cefotaxime, cefoperazone, latamoxef and cefodizime were examined against experimental pneumonia caused by Klebsiella pneumoniae DT-S in mice. When compared in terms of MIC values against the infecting organism and the pharmacokinetic pattern, cefpirome showed equal activity and a similar pharmacokinetic behavior to ceftazidime and cefotaxime in mice. Trials to assess the bactericidal activity in vivo, however, showed that cefpirome displayed a more marked bactericidal effect in pneumonic mice than the other cephalosporins tested. Only cefodizime, a cephalosporin with extremely high and prolonged blood and tissue levels in experimental animals exerted chemotherapeutic effects similar to cefpirome. After cefpirome or cefodizime medication (50 mg/kg), the viable counts in the lungs of experimental animals fell steadily to 1/10,000 of the pretreatment level and, in contrast to the reference compounds, no regrowth of the challenge organisms could be observed with both drugs. Moreover, with ED50s ranging from 1.1 to 59.1 mg/kg in treatment studies, cefpirome as well as cefodizime were two to ten times more effective than ceftazidime and cefotaxime, whereas cefoperazone and latamoxef were considerably less effective.

[Effect of cefodizime on the immune system: in vitro studies]

Cefodizime is a broad-spectrum cephalosporin with high efficacy, especially in experimental infections. The in vivo activity may be partly due to an immunomodulatory effect. Macrophages in cefodizime-treated mice showed enhanced activity (chemiluminescence, IL-1-synthesis, IFN-synthesis). The number of PFC increased during the treatment with cefodizime. The spleen cells of these mice showed elevated responses to dextransulfate and LPS but not to ConA or PHA.

Chemotherapeutic effects of ofloxacin (HOE 280) and other quinolone-carboxylic derivates in the treatment of experimental lung infections due to Klebsiella pneumoniae DT-S in mice

The chemotherapeutic activity of ofloxacin (HOE 280), a new pyridone-carboxylic acid derivative, was compared with that of other drugs in the same group, including norfloxacin, ciprofloxacin, enoxacin and in some cases pipemidic acid and nalidixic acid. The test model used was experimental pneumonia caused by Klebsiella pneumoniae DT-S in mice. In the treatment of pneumonic mice, ofloxacin was 4 to 18 times more effective than norfloxacin and enoxacin and in most cases slightly more effective than ciprofloxacin. Pipemidic acid and nalidixic acid showed only low activity or proved to be inactive. In studies on the bactericidal activity of the compounds in vivo, ofloxacin produced a more pronounced effect than ciprofloxacin. With norfloxacin and enoxacin, a bactericidal effect in the infected tissue of the animals was only observed during the first hours after treatment.

Cefodizime, an aminothiazolyl cephalosporin. III. Therapeutic activity against experimentally induced pneumonia in mice

The activity of the aminothiazolyliminomethoxy cephalosporin cefodizime (HR 221) was compared to that of cefotaxime, cefuroxime and cefazolin in experimental pneumonia caused by Klebsiella pneumoniae DT-S in mice. Cefodizime exhibited high and long-acting levels in the blood and lung homogenates of infected mice; the blood and tissue concentrations obtained with the other cephalosporins tested were low by comparison. In the treatment of experimental Klebsiella pneumonia, cefodizime was superior to cefotaxime and cefuroxime. Counts of the number of viable bacteria present in the infected tissue showed that cefodizime exerted a more marked bactericidal effect than cefotaxime or cefuroxime. Hardly any therapeutic activity was seen with cefazolin.

Cefodizime, an aminothiazolyl cephalosporin. IV. Influence on the immune system

Studies concerning the activity of cefodizime (HR 221), on certain aspects of the immune response, were conducted. It was found that lymphocytes from Balb/c mice treated with 3 and 30 mg/kg/day of cefodizime display increased responsiveness to B-cell mitogens and specific antigens. Also, the amount of antigen specific antibody producing plaque forming cells was increased in these mice and was accompanied by a rise in the specific IgG haemagglutinin titer. These effects were not observed in lymphocytes obtained from NMRI mice that had been treated with cefodizime. Peritoneal macrophages from NMRI mice, treated with cefodizime prior to harvesting of the cells, contained increased levels of lysosomal enzymes, developed enhanced chemiluminescent reaction to stimuli and showed elevated pinocytosis rates. Furthermore, NMRI mice treated with cefodizime during the immunization, developed enhanced DTH-reaction, when challenged with the antigen (SRBC). The prophylactic treatment of Balb/c mice with cefodizime (2 X 30 mg/kg/day ip for 4 days) significantly prolonged the mean survival time of the animals after intravenous infection with Candida albicans 200/175 (16.7 days as against 3.5 days in the case of the controls). This stimulatory effect of cefodizime on the host defence system was not observed for NMRI mice. Treatment with latamoxef or cefoperazone under the same experimental conditions did not reduce the susceptibility of mice to C. albicans. The protective activity of cefodizime against C. albicans in Balb/c mice, may be due to the immuno-stimulatory activity of this agent.

Cefodizime, an aminothiazolylcephalosporin. I. In vitro activity

Cefodizime possesses a broad antibacterial spectrum including staphylococci, streptococci and Enterobacteriaceae. Neisseria gonorrhoeae and Haemophilus influenzae are also highly susceptible to cefodizime. Because of its beta-lactamase stability cefodizime is active against bacterial strains producing especially plasmid-coded enzymes. The MICs of cefodizime are slightly higher than those of cefotaxime, but with most Gram-negative bacteria they are lower than those of cefazolin, cefotiam and piperacillin. The in vitro activity of cefodizime is not dependent on inoculum size, or on the pH and composition of the test medium. Cefodizime did not induce in vitro resistance of Staphylococcus aureus or Escherichia coli. Because of its binding properties to PBPs 1A/B and 3, cefodizime leads to filamentation of Gram-negative rods and, at only slightly higher concentrations, to bacteriolysis.

Cefodizime, an aminothiazolylcephalosporin. II. Comparative studies on the pharmacokinetic behavior in laboratory animals

The pharmacokinetic properties of cefodizime, a new aminothiazolyliminomethoxycephalosporin, were studied in laboratory animals and compared with the pharmacokinetics of another long-acting cephalosporin, ceftriaxone. Both cephalosporin derivatives showed high affinity (33-99%) for serum proteins. High and prolonged blood respectively serum levels of the antibiotics were achieved following subcutaneous and intravenous injection into mice, rats, rabbits, dogs and monkeys. Cefodizime elimination half-lives ranged from 1.17 hours in mice to 3.53 hours in rabbits compared to ceftriaxone half-lives ranging from 0.73 hour in mice to 7.31 hours in rabbits. The antibiotics were well distributed in the body and penetrated into tissues and body fluids to a high degree. Particularly high and prolonged levels were detected in the lungs, liver and kidneys of the experimental animals. Large amounts, approximately 35-55% of the given dose, were recovered in the urine of rabbits and dogs, while the recovery rate in the bile of rabbits was only 0.57% for cefodizime and 1.08% for ceftriaxone.

Chemotherapeutic properties of the new cephalosporin antibiotic HR810 in laboratory animals

The chemotherapeutic properties of the new aminothiazolyl cephalosporin HR810 were investigated in experimental animals. Unlike other cephalosporins of the third generation, HR810 had good activity against Staphylococcus aureus as well as some activity against enterococci. In murine protection tests with these strains, it was clearly superior to ceftazidime, cefotaxime, ceftriaxone, cefoperazone and latamoxef. The compounds most effective in protecting mice from infections caused by Enterobacteriaceae were HR810 and ceftriaxone followed by ceftazidime, latamoxef and cefotaxime; cefoperazone was less active. HR810 was less active against Pseudomonas aeruginosa than ceftazidime but was considerably more effective than the other cephalosporins tested. HR810 also proved effective against localised infections such as thigh lesions, as well as against meningo-encephalitis in mice and pyelonephritis in rats. These results in laboratory animals make HR810 a promising candidate for clinical studies.

The in vitro antimicrobial activity of desacetylcefotaxime compared to other related beta-lactams

Like all other cephalosporins that contain an acetyl side chain in the 3' position, cefotaxime (CTX) is partially desacetylated in vivo. Desacetylcefotaxime (des-CTX) possesses a broad antimicrobial spectrum and high beta-lactamase stability. With the exception of Pseudomonas aeruginosa, Morganella morganii, Bacteroides fragilis, and Staphylococcus aureus, most strains of other species tested usually had mean MICs of des-CTX lower than 1 microgram/ml. Its activity is generally lower than that of the parent compound. It was only against some strains of P. cepacia that des-CTX surpassed the activity of CTX. The activity of des-CTX markedly exceeds the activity of many therapeutically used cephalosporins. This is especially true for Haemophilus influenzae, Neisseria meningitidis, most species of Enterobacteriaceae, and streptococci other than Streptococcus faecalis.

Comparison of the antibacterial in vitro and in vivo activity of ofloxacin (HOE 280 DL 8280) and nalidixic acid analogues

The in vitro and in vivo activity of ofloxacin (DL 8280, HOE 280) was compared with that of other antibacterial compounds. Ofloxacin was found to have a broad antibacterial spectrum which includes both gram-positive and gram-negative aerobic and anaerobic species. Its activity is generally higher than that of pipemidic acid and nalidixic acid. Against staphylococci and streptococci, ofloxacin proved to be more active than norfloxacin. In the case of Enterobacteriaceae and Pseudomonadaceae, ofloxacin and norfloxacin possess comparable activities. Ofloxacin was the most active compound against a number of aerobic isolates which are resistant to cefotaxime and ceftriaxone. Of the compounds compared, ofloxacin was the only one which exhibited reasonable activity against anaerobes. It inhibited all strains of Bacteroides fragilis at a concentration of 3.125 mg/l and the gram-positive anaerobes at 0.5 mg/l. In mice experimentally infected with various gram-positive and gram-negative bacteria, ofloxacin was more active than norfloxacin and pipemidic acid. With the gram-negative pathogens, orally administered ofloxacin was as active as gentamicin used parenterally. We conclude from our studies that ofloxacin could be a valuable therapeutic agent with a variety of indications.

The Antibacterial activity in vitro and beta-lactamase stability of the new cephalosporin HR 810 in comparison with five other cephalosporins and two aminoglycosides

The antibacterial activity of the cephalosporin antibiotic HR 810 was evaluated in comparison with cefoperazone, cefotaxime, ceftazidime, ceftriaxone, latamoxef, gentamicin and amikacin against 1500 clinical isolates. HR 810 is the antibiotic with the broadest antimicrobial spectrum. It is also highly active against isolates of the genera Pseudomonas, Enterobacter, Staphylococcus and enterococci. HR 810 is very stable against hydrolysis by plasmid-coded and chromosomally coded beta-lactamases.

HR 810, a new parenteral cephalosporin with a broad antibacterial spectrum

3-[(2,3-Cyclopenteno-1-pyridinium)-methyl]-7-[2-syn-methoximino-2-(2-aminothiazol-4-yl)-acetamido]-ceph-3-em-4-carboxylate (HR 810) is a new cephalosporin derivative with an extremely broad antimicrobial spectrum. It is active against all bacterial species of clinical relevance, including strains which are frequently resistant towards cephalosporins of the third generation.

Purification and characterization of a cephalosporinase from E. coli

The isolation and properties of a beta-lactamase from E. coli are described, which hydrolyses the Cephalosporins of the third generation. The enzyme has been brought to high purity by precipitation with (NH4)2SO4, gel chromatography and affinity chromatography on Cephalosporin C bound to agarose. The enzyme has been characterized by evaluation of its molecular weight 39 000, isoelectric point (pH 7.2), pH-optimum (pH 8.4) and substrate profile. It accepts Ceftizoxime, Cefamandole, Cefazolin and Cefotaxime as substrates, but shows nearly no activity on Penicillin G, Cefoxitin and the Desacetylmetabolite of Cefotaxime.

The cooperation of cefotaxime and desacetyl-cefotaxime with respect to antibacterial activity and beta-lactamase stability

Desacetyl-cefotaxime, the main metabolite of cefotaxime, possesses a broad antibacterial spectrum. Its activity is lower than that of cefotaxime, but significantly surpasses that of cefazolin against gram-negative bacteria. The beta-lactamase stability of desacetyl-cefotaxime is higher than that of the parent compound. This beta-lactamase stability might be responsible for the synergistic effects of cefotaxime and desacetyl-cefotaxime occasionally seen in in vitro combination studies.

Activation by some T-independent antigens and B cell mitogens of the alternative pathway of the complement system

A number of T-independent antigens and B cell mitogens were examined for their ability to activate C3 via the alternative pathway of the complement system. Loss of hemolytically active C3, generation of anaphylatoxin activity, and immunoelectrophoretic conversion of C3 and factor B, were checked in normal and C4-deficient guinea pig serum, and, in some cases, in normal human serum. As judged by their activity in these assays, 10 lipopolysaccharides of different origin and constitution, pneumococcus type III polysaccharide, levan, dinitrophenylated aminoethyl-dextran, dinitrophenylated (D-glutamic acid, D-lysin) copolymer, polymerized flagellin, and pokeweed mitogen were all capable of initiating the alternative pathway, but differed with respect to their potency, their relative activity in the presence or absence of C4, and their ability to inhibit C3-turnover at high concentrations. Polyvinylpyrrolidone of intermediate molecular weight (4 x 10(4) daltons) was only active if the most sensitive assay was used (anaphylatoxin generation). Other species of polyvinylpyrrolidone, depolymerized pneumococcal polysaccharide, aminoethyl-dextran, [D-glutamic acid, D-lysin] copolymer, phytohemagglutinin and concanavalin A failed to activate C3. C3-consumption by concanavalin A was due to nonspecific binding.