Antimicrobial activities of piperacillin alone and in combination with tazobactam against beta-lactamase-producing bacteria

Tazobactam (YTR 830), a new beta-lactamase inhibitor, was evaluated for its effect in combination with piperacillin, a broad spectrum, but beta-lactamase sensitive, penicillin, against 14 common bacteria. A total of 1,086 clinical isolates from different clinical specimens were tested for beta-lactamase production by the rapid chromogenic cephalosporin method. Their susceptibilities to piperacillin alone and in combination with tazobactam in a ratio of 8:1 by the agar dilution method were evaluated. The percentage of beta-lactamase producing strains ranged from 14.5% to 100% in these tested species. In general, the beta-lactamase producers were more resistant to piperacillin than the beta-lactamase nonproducers with higher minimal inhibitory concentrations (MICs). For the beta-lactamase producers, tazobactam decreased the MICs of piperacillin prominently in methicillin-resistant Staphylococcus aureus, Neisseria gonorrhoeae, Haemophilus influenzae, Escherichia coli, Proteus mirabilis, Morganella morganii, Salmonella species and Bacteroides fragilis, with a 4-fold or greater decrease in MIC50, MIC90 and the geometric mean of MIC. For Serratia marcescens and Pseudomonas aeruginosa, the MICs did not change after adding tazobactam. For other species, there was a moderate decrease in MICs. We conclude that tazobactam is an effective beta-lactamase inhibitor for increasing the antimicrobial activity of piperacillin against beta-lactamase producing strains of many species of bacteria.

[Age and pulmonary function testing in predicting postoperative morbidity after thoracic surgery]

In order to evaluate whether age and pulmonary function testing may predict postoperative morbidity and mortality in the patients having received thoracic surgery, 203 patients were included in this study. Spirometry, flow volume curve, lung volume determination and arterial blood gas analysis were performed in all of them. Postoperative complications were classified into respiratory complications including pneumonia, purulent bronchitis, atelectasis, respiratory failure and so on; and non-respiratory complications including subcutaneous emphysema, internal bleeding, stump leakage, dysarrythmia and so on. Of the 117 patients over 65 years of age, 27 (23.1%) had postoperative respiratory complications, 27 (23.1%) had non-respiratory complications, and 7 (5.93%) expired postoperatively. Of the 86 patients under 65 years of age, 21 (24.4%) had postoperative respiratory complications and 9 (7.6%) had postoperative non-respiratory complications, but one expired. The incidences of postoperative mortality and non-respiratory complications were both higher in the patients over 65 years of age (p less than 0.05). Our results indicated that age is a risk factor of thoracic surgery, even if the pulmonary function testing meet the surgical criteria.

Actinobacillus actinomycetemcomitans endocarditis: a report of four cases and review of the literature

Four patients with infective endocarditis caused by Actinobacillus actinomycetemcomitans seen at the National Taiwan University Hospital between January 1985 and December 1990 are reported. There were two men and two women with a mean age of 40 years. Three had had a xenograft replacement, the other one had prolapse of mitral valve. Carious teeth were noted in two. The most common presenting symptoms were fever, cough, dyspnoea, and weight loss and the duration of symptoms before diagnosis varied from 2 weeks to 2 months. Peripheral stigmata of endocarditis were not present in any patient. Laboratory investigation revealed haematuria and anaemia in three patients, and elevated erythrocyte sedimentation rates in all four. None had leucocytosis. Echocardiography was performed more than once for each patient and vegetation was demonstrated in only one. Blood culture became positive after 7-10 days of incubation. One of the isolates was resistant to penicillin. The diagnosis was delayed due to the indolent clinical course, non-specific presentation, and the slow growth of the organism. However, all patients were cured clinically and bacteriologically after 6 weeks of intravenous antibiotic therapy which included penicillin, cefamandole, chloramphenicol, or aztreonam, with or without an aminoglycoside. All patients were free of evidence of recurrence after 6-25 months of follow-up.

Factors affecting the production of eremofortin C and PR toxin in Penicillium roqueforti

Eremofortin C (EC) and PR toxin are secondary metabolites of Penicillium roqueforti. Of 17 strains from the American Type Culture Collection that were studied for their ability to produce EC and PR toxin, 13 produced these metabolites. Toxin production by strains grown in solid media (10 cereals and 8 other agricultural products) was also investigated. Production of EC and PR toxin by fungi grown on cereals was greater than production of EC and PR toxin by fungi grown on legumes; fungi grown on corn produced the greatest amount of PR toxin. Addition of corn extracts to the culture medium greatly increased the production of EC and PR toxin in a coordinated manner, with no significant change in mycelial dry weight. The fungi produced the highest levels of EC and PR toxin at 20 to 24 degrees C depending on the strain. Toxin production was higher in stationary cultures than in cultures that were gently shaken at 120 rpm. The optimum pH for production of both EC and PR toxin was around pH 4.0. With regard to spore age, toxin levels did not change significantly when we used spores obtained from fungi that were grown at 24 degrees C for 3 up to 48 days.

In vitro activities of 36 antimicrobial agents against clinically isolated Bacteroides fragilis

Thirty-six antimicrobial agents were evaluated for in vitro activities against 100 clinical isolates of Bacteroides fragilis. The minimal inhibitory concentration (MIC) of each agent for each isolate was determined by the agar dilution method. Among 25 beta-lactam antibiotics, the most active agent was imipenem with an MIC90 and a geometric mean of 1 and 0.15 micrograms/ml, respectively; followed by ticarcillin-clavulanic acid, and amoxicillin-clavulanic acid. Ampicillin-sulbactam, piperacillin-tazobactam, moxalactam, and flomoxef were the next most active agents. Piperacillin, ticarcillin, ceftizoxime, cefotaxime, cefuzonam, cefoxitin, and cefmetazole were equally active with the MIC50s ranging from 4 to 16 micrograms/ml, and MIC90s ranging from 32 to greater than or equal to 256 micrograms/ml. The remaining 10 beta-lactam antibiotics, ampicillin, amoxicillin, cefazolin, cefuroxime, cefoperazone, cefmenoxime, ceftazidime, cefpirome, aztreonam, and carumonam were less active. All isolates were resistant to cefotiam at a low breakpoint. Among 6 quinolones, ciprofloxacin was the most active agent with an MIC50 and an MIC90 of 4 and 16 micrograms/ml, respectively. All isolates were resistant to nalidixic acid, pipemidic acid, cinoxacin, enoxacin, and norfloxacin. Among 5 frequently used agents, chloramphenicol, ornidazole, and metronidazole were the most effective agents which inhibited 100% of the isolates at 8, 2, and 2 micrograms/ml, respectively; while clindamycin and minocycline had less activity.

Usefulness of bronchoalveolar cell profile in early detection of canine lung allograft rejection

To evaluate the value of a bronchoalveolar cell profile in the early detection of canine lung allograft rejection, bronchoalveolar lavages were done serially in mongrel dogs before and after single lung transplantation. The dogs were divided into 3 groups. In group 1, neither donor nor recipient dogs were treated with cyclosporine. In group 2, only donors were treated with cyclosporine, orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3, only recipients were treated with cyclosporine (20 mg/kg/day) for 9 days after single lung transplantation. A marked increase in the number of bronchoalveolar cells and their cell differentials, and of major histocompatibility complex (MHC) class II-positive cells obtained from the grafted lungs after lung transplantation, was seen in groups 1 and 2. The changes in bronchoalveolar cell profile obtained from the rejecting grafted lungs were significantly different from those obtained from the normal and native lungs (P less than 0.05). In group 3, the bronchoalveolar cell profile obtained from the grafted lungs did not significantly differ from those present in normal and native lungs during the period of cyclosporine treatment after lung transplantation. On various days after withdrawal of cyclosporine treatment, bronchoalveolar cell profiles obtained from the grafted lungs showed similar changes to those observed in groups 1 and 2. Abnormal changes in bronchoalveolar cell profiles obtained from the grafted lungs heralded the appearance of abnormalities detected by chest X-ray films. Our results indicate that serial measurements of bronchoalveolar cell profile may serve as a useful means for early detection of canine lung allograft rejection.

Antibacterial activities of amoxicillin alone and in combination with clavulanic acid correlated with beta-lactamase production

Amoxicillin, a beta-lactam antibiotic, was tested for its effect in combination with clavulanic acid, a beta-lactamase inhibitor, against 9 species of bacteria isolated from clinical specimens. A total of 698 strains of bacteria were tested for beta-lactamase production by the rapid chromogenic cephalosporin method. Their susceptibilities to amoxicillin alone and in combination with clavulanic acid were tested by the agar dilution method. The percentage of beta-lactamase producing strains ranged from 46.6% in Proteus mirabilis to 100% in Klebsiella pneumoniac. In general, beta-lactamase nonproducers were more susceptible to amoxicillin than beta-lactamase producers. For beta-lactamase producers, clavulanic acid decreased the MICs of amoxicillin prominently in strains of Neisseria gonorrhoeae, Haemophilus influenzae, Escherichia coli, K. pneumoniae, P. mirabilis, Enterobacter cloacae and Bacteroides fragilis, when combining clavulanic acid with amoxicillin in the ratio of 1:2. Their MIC50s, MIC90s and geometric means of MICs all decreased 4 folds or greater. For beta-lactamase non-producing strains, the MICs did not show significant differences by adding clavulanic acid in most species we tested, including methicillin-sensitive Staphylococcus aureus, N. gonorrhoeae, H. influenzae, Proteus vulgaris and E. cloacae.

A new classification of female stress urinary incontinence--based on transrectal sonographic cystourethrography

A new classification of female stress urinary incontinence was made according to the results of transrectal ultrasonography of the urinary bladder and urethra (cystourethrography) studied in 67 women with genuine stress urinary incontinence (SUI). This classification is based on the following changes of the bladder and urethra on abdominal straining: hypermobility of the urethra, bladder neck incompetence, urethral sphincter incompetence and presence of a cystocele. Five types of SUI has been classified. We believe that this new classification can provide a better understanding of the anatomical changes as well as the pathophysiology of SUI. In addition, it can serve as a guideline of proper surgical management for SUI.

Potentiation effect of corn extract on the production of eremofortin C, EC oxidase, and PR toxin by Penicillium roqueforti

Eremofortin C (EC) and PR toxin are secondary metabolites of Penicillium roqueforti. Their structures are similar and differ only by an alcohol and an aldehyde group at the C-12 position. EC has been demonstrated to be the precursor of PR toxin, and EC is transformed to PR toxin by EC oxidase. These two compounds and EC oxidase are secreted by P. roqueforti in the culture medium, which is usually composed of 15% sucrose and 2% yeast extract. Recently, we discovered that the addition of corn extract to this medium increased the production of EC and PR toxin and the activity of EC oxidase in a coordinative manner. In a time-course study, we found that the peak yield of EC and PR toxin and the maximum activity of EC oxidase in the culture medium containing 7.5% sucrose, 1% yeast extract, and 20% corn extract were increased 6.2, 4.6, and 4.7-fold, respectively, as compared with those obtained in the medium without corn extract. Moreover, corn extract increased the production of EC and PR toxin and the activity of EC oxidase by P. roqueforti in a dose-dependent manner. On the other hand, when the concentrations of sucrose and yeast extract were increased while fixing the ratio of corn extract, we found that the levels of EC and PR toxin and the enzyme activity were decreased concomitantly. We thus conclude that corn extract can enhance the production of EC, PR toxin and EC oxidase by P. roqueforti when grown in a minimal medium and that the potentiation effect of corn extract is suppressed when the fungi are grown in a rich medium.

Dissociation of opioid receptor upregulation and functional supersensitivity

Alterations in brain opioid binding and opioid pharmacodynamics following chronic (8-day) naltrexone (NTX) treatment were determined in pertussis toxin (PTX)-treated mice. Intrathecal (IT) and intracerebroventricular (ICV) PTX produced a time-dependent, long-lasting inhibition of morphine (SC) analgesia without modifying basal nociception. Inhibition was maximal 16 days following PTX treatment, and was still observed at 40 days. Relative to placebo controls, NTX treatment produced supersensitivity to morphine analgesia in all control mice and in mice pretreated with PTX 1 day before NTX. Supersensitivity was not observed in 7-day PTX-pretreated mice. [3H][D-Ala2-D-Leu5]enkephalin ([3H]DADLE) and [3H][D-Ala2-MePhe4-Gly(ol)5]enkephalin ([3H]DAMGO) binding sites were increased by NTX treatment in saline- and PTX-pretreated groups. KDs were unchanged. These results indicate that PTX does not alter opioid antagonist-induced receptor upregulation. However, PTX treatment can diminish morphine potency in upregulated and control mice. Therefore, opioid analgesia in control and upregulated mice appears to be mediated by receptors linked to a common PTX-sensitive G-protein. Furthermore, in 7-day PTX-pretreated mice, NTX increased binding sites without altering morphine potency, which suggests that new binding sites can appear without being functionally coupled.

Modification of morphine-induced analgesia and toxicity by pertussis toxin

The present study evaluates the effect of pertussis toxin (PTX) on morphine-induced analgesia and lethality. Mice were injected with 0.2 microgram PTX intracerebroventricularly (i.c.v.) and 0.2 micrograms PTX intrathecally (i.t.) or saline. Mice were tested for morphine-induced analgesia (tail flick) and lethality 16 days later; mice were also examined for pentobarbital-induced mortality. Morphine analgesic potency was decreased by approximately 4-fold in PTX-treated mice compared to controls. Conversely, the lethal potency of morphine was increased by 10-fold in PTX-treated mice compared to controls. PTX treatment did not alter the lethal potency of pentobarbital. Morphine-induced analgesia and lethality were dose-dependently antagonized by naloxone in both PTX and saline-treated groups. The results of this study suggest that morphine analgesia is mediated through PTX-sensitive G proteins. On the other hand, morphine-induced lethality appears to be limited by PTX-sensitive factor(s) since PTX treatment enhanced morphine's lethal potency. The increase in lethal potency of morphine may be due to unmasking of an excitatory opioid receptor mediated effect by PTX.

Significance of biochemical markers in early detection of canine lung allograft rejection

To evaluate the significance of bronchoalveolar lavage fluid, levels of tumor necrosis factor-alpha (TNF), gamma-interferon, interleukin 2, and soluble IL-2 receptor in early detection of canine lung allograft rejection, bronchoalveolar lavages were performed serially in mongrel dogs before and after single lung transplantation. The dogs were divided into three groups. Group 1 (control group) consisted of one in which neither donor nor recipient dogs were treated with cyclosporine. In group 2 (CsA-pretreated group) only donors were treated with CsA orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3 only recipients were treated with CsA orally at a single dose of 20 mg/kg/day for a short period of 9 days after single-lung transplantation. Marked elevation was found of TNF, IFN-gamma, IL-2, and IL-2R in BALF obtained from the grafted lungs in group 1 and group 2 dogs. The levels of these markers were significantly higher than those obtained from the normal, native lungs (P less than 0.05). Two of three recipients in group 2 had pneumonia in the native lungs on day 10 after single-lung transplantation. All markers except IFN-gamma in BALF obtained from the infected native lungs were also increased, but the titers were less than those obtained from the grafted lungs at the same time. There were significantly higher levels of TNF, IL-2, and IL-2R present in the BALF of grafted lungs of dogs in group 1 than group 2 (P less than 0.05). In group 3, BALF levels of these markers from the grafted lungs were not significantly different from those of the normal and native lungs during the period of CsA treatment after single-lung transplantation. On various days after discontinuation of CsA treatment, BALF levels of all markers began to rise. Abnormal levels of BALF markers obtained from the grafted lungs heralded the appearance of abnormalities detected by chest x-ray films. Our study suggests that serially measuring BALF levels of TNF, IFN-gamma, IL-2, and IL-2R may serve as a useful means in monitoring the immunologic status of canine lung allografts and in the early detection of lung allograft rejection. The role of BALF IFN-gamma in distinguishing lung allograft rejection from pulmonary infection needs further studies.

Analysis and tracing of polycyclic aromatic hydrocarbons and mutagenicity of airborne particulates from the Taipei area

In a 3-year study, we determined the mutagenicity and polycyclic aromatic hydrocarbons (PAHs) of airborne particulates collected during December 1987-September 1988 (216 samples), October 1988-January 1989 (81 samples), and October 1989-April 1990 (52 samples) from 9 locations in the Taipei area. We found that dichloromethane extracts of all the samples were mutagenic to Salmonella typhimurium in the Ames test. Moreover, the mutagenicity was much higher in the presence of rat liver microsomal fraction (S9 mixture) than that observed in its absence, which indicates that airborne particulates contained both direct and indirect mutagens. The average mutagenicity of the samples collected in the 3-year period was 137, 127, and 118 histidine revertants/10 m3 air, respectively. On the other hand, we found that dichloromethane extracts of each airborne particulate sample contained 14 PAHs with wide variations in concentration and relative distribution. The levels of Pha, Flu, Pyr, and Ben were much higher than the PAHs with higher ring numbers such as BaP, BeP, Pr, IP, and DbA. The average PAH content was 8.0, 5.0, and 7.8 ng/m3 air for airborne particulates collected during December 1986-September 1987, October 1988-January 1989, and October 1989-April 1990, respectively. Among the 9 stations, Fu Hsing Elementary School and Chung Hsing University (Taipei campus), which are, respectively, located in the downtown area and a heavy traffic zone, had significantly higher levels of mutagenicity and PAHs than did the other stations. Moreover, comparative analysis of PAH levels of airborne particulates over the 3-year period revealed an interesting season-dependent change of PAH content in airborne particulates from the Taipei area. The concentrations of individual and total PAHs were consistently lower in the summer than those in the winter. A similar pattern of seasonal change was also observed in the mutagenicity of airborne particulate samples examined. It is worth mentioning that neither PAH level nor mutagenicity of airborne particulates showed significant yearly change over the 3-year period of study. As part of an effort to identify pollution sources, we examined the mutagenicity and PAH compounds of air particulates collected from the burning of garbage (14 samples) and motor-vehicle exhaust in the Hsin Hai Tunnel (17 samples), Taipei. The results showed that garbage burning gave rise to air particulates containing several hundred times higher levels of PAHs and about 20 times stronger mutagenicity, while the motor-vehicle exhaust contained about ten times higher PAH content and mutagenicity as compared with those of airborne particulates of the Taipei city.(ABSTRACT TRUNCATED AT 400 WORDS)

Pneumothorax following cytotoxic chemotherapy in malignant lymphoma

Pneumothorax occurring as a complication of the antitumor effect of cytotoxic chemotherapy has been reported in occasional cases of a variety of tumors. Its occurrence in malignant lymphoma has not been reported heretofore. In this report, we describe two cases of this complication in patients with malignant lymphoma and discuss the possible pathophysiologic mechanisms involved. Because pulmonary involvement with the tumor was found in both cases, pneumothorax could be attributed to the anti-tumor effect of cytotoxic agents on underlying lung involvement in patients with malignant lymphoma.

Transrectal sonographic cystourethrography: studies in stress urinary incontinence

Transrectal ultrasonic sagittal transducer is an excellent modality to image the bladder and urethra in dynamic change. In female patients, we found it is also helpful for the diagnosis of urinary stress incontinence. The posterior urethrovesical (PUV) angle is measured with the transrectal sonoprobe under strain and non-strain conditions. We compared the results of sonographic cystourethrogram with the radiographic chain cystourethrogram. The sonographic cystourethrography is superior to the radiography. The former may estimate the PUV angle accurately and differentiate between the patients with and without stress urinary incontinence. Furthermore, we also use the transrectal sagittal probe intraoperatively to adjust the suspension force as well as PUV angle in patients who underwent vesical neck suspension for stress urinary incontinence (SUI).

[Epidemiologic study of pathogens causing nosocomial infections]

Nosocomial infection is a global problem. It significantly adds to the expected duration of hospitalization resulting with an increased economic burden and represents a leading cause of death. The characteristics of nosocomial infection vary from country to country and also changes with time. In order to understand the pathogens causing nosocomial infection in the large teaching hospital in Taiwan, we collected and analysed the surveillence data of nosocomial infection at the National Taiwan University Hospital from 1981 to 1989. We found that the nosocomial infection rate had been around 4-5% annually since 1981 till 1989. As ranked according to the site of infection, surgical wound infections were the most common, followed by the urinary tract, respiratory tract, and blood stream infections. However, the incidence of surgical wound infections had decreased gradually. About one third of nosocomial infections were caused by multiple microorganisms. The most frequently isolated pathogen has changed from Escherichia coli in early years to Pseudomonas aeruginosa in the most recent years. Gram-negative aerobic bacteria has been the major pathogens resulting in nosocomial infections for the past 9 years, accounting for 55-66%. In contrast, fungi have increased rapidly from 1.8% of total isolates in 1981 to 7.7% in 1989. Gram-positive cocci have also increased in recent years. The leading pathogen by infection site was P. aeruginosa in surgical wound infections, E. coli in urinary tract infections, and P. aeruginosa in respiratory tract infections. In earlier years E. coli was the major isolate in bacteremic cases, but glucose non-fermenters, including P. aeruginosa, Acinetobacter calcoaceticus and others, plus Enterobacter species-emerged as the major pathogens of recent years.(ABSTRACT TRUNCATED AT 250 WORDS)

MHC class II antigens on canine bronchoalveolar cells

To evaluate the expression of MHC (major histocompatibility complex) antigens on canine bronchoalveolar cells (BAC), bronchoalveolar lavages (BAL) were performed in mongrel and German shepherd dogs. MHC class II antigens on canine BAC and peripheral blood mononuclear cells (PBMC) were detected by monoclonal antibodies (mAbs) B1F6, 7.5.10.1 and Q5/13 recognising canine MHC class II antigens, using cytofluorometry. These mAbs reacted with more than 20% of BAC and PBMC in both breeds of dog. The percentage of MHC class II positive cells in BAC were lower than those in PBMC. There was no significant difference in the percentages of MHC class II positive BAC and PBMC in mongrel and German shepherd dogs. To further identify the expression of MHC class II antigens on BAC, the cells were separated into adherent and nonadherent cells by petri dish adherence. The percentages of MHC class II positive cells in adherent and non-adherent cell populations were similar. Nearly half the lymphocytes in normal BAC were T cells detected by mAbs F3-20-7 and 1A1; B cells were scarce and represented less than 10% of nonadherent cells. Immunoprecipitation by anti-MHC class II mAbs, and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) revealed MHC class II-like molecules on canine BAC and PBMC. After stimulation with phytohaemagglutinin (PHA), the percentages of class II positive cells in BAC and PBMC were significantly increased. Thus, these anti-MHC class II mAbs may prove to be of advantage in experiments designed to evaluate the changes in class II antigen expression on canine BAC during the course of immune response in the lung, as in pulmonary allograft rejection.

Effects of dietary manganese deficiency on rat pancreatic amylase mRNA levels

Manganese deficiency is associated with increased pancreatic amylase activity in rats. The present study investigated whether this increase in amylase activity is associated with increased pancreatic amylase messenger RNA (mRNA) levels. Weanling rats were fed a high carbohydrate diet containing either 40 micrograms Mn/g (control) or 0.5 microgram Mn/g (deficient) for 4 to 8 wk. Mn deficiency was confirmed by determining hepatic Mn content, which was significantly lower in Mn-deficient rats than in controls. Pancreatic RNA from both groups of rats was hybridized with 32P-labeled complementary DNAs for amylase and trypsinogen. Amylase mRNA levels were increased in rats fed Mn-deficient diets for both 4 wk (200%) and 8 wk (250%) when compared with respective control levels. In contrast, Mn deficiency was not associated with alterations in trypsinogen mRNA levels. Serum levels of insulin and corticosterone, hormones known to increase pancreatic amylase mRNA, were not affected by Mn deficiency. These observations suggest that Mn may participate in the regulation of amylase gene expression in a manner that is independent of insulin and corticosterone.

Staphylococcus aureus endocarditis in drug addicts: report of 2 cases

Two young men presented with prolonged hectic fever and chills followed by chest pain, dyspnea and hemoptysis. The chest films revealed multiple lung infiltrates, and blood cultures yielded Staphylococcus aureus. Echocardiographic examination confirmed the diagnosis of tricuspid valve endocarditis. Multiple punctate lesions in the bilateral inguinal areas and dragon tattoos over the forechest gave rise to the suspicion of drug abuse. After prolonged antimicrobial therapy, bacteremia was eliminated, and elective vegetectomy and valvuloplasty were performed on one of the patients. The other one suffered recurrent episodes of pulmonary embolism. Disappearance of the large vegetation was disclosed by echocardiography. Both of them eventually regained their health with the abstinence of drugs. This report illustrates two typical cases of infective endocarditis in drug addicts.

Antimicrobial activities of six new oral cephem antibiotics

Six newly developed oral cephem antibiotics, which included 5 with an aminothiazolyl side chain, viz., cefixime, cefotiam hexetil, cefpodoxime proxetil, cefteram pivoxil, ceftibuten, and one with a conventional side chain design, BMY 28100, were tested for their antimicrobial activities. Three traditional oral beta-lactam antibiotics, ampicillin, cephalexin, and cefaclor, were used as reference antibiotics. The 5 aminothiazolyl cephems were more active than the reference drugs against clinical isolates of Escherichia coli, Klebsiella pneumoniae and Haemophilus influenzae. All 6 new drugs showed poor activity against clinical isolates of Enterobacter cloacae, Pseudomonas aeruginosa, and enterococci. They were better than cephalexin and cefaclor, but slightly poorer than or the same as ampicillin in activities against Streptococcus pyogenes and Streptococcus pneumoniae. Cefotiam hexetil, BMY 28100, and cefpodoxime proxetil were also more active than cephalexin against Staphylococcus aureus. Although the 6 tested new oral cephems demonstrated little difference in their activities against different bacteria, they all showed greater antimicrobial activity than the traditional oral antibiotics now in clinical use.

(S)-2-hydroxypropyl-beta-cyclodextrin, a new chiral stationary phase for reversed-phase liquid chromatography

(S)-2- and (R,S)-2-hydroxypropyl-beta-cyclodextrin have been bonded to silica gel and evaluated as stationary phases for reversed-phase liquid chromatography. Stationary phases also were prepared on two silicas having different pore sizes and surface areas. Dissimilarities were observed in enantiomeric selectivities between these columns and also between these and the native beta-cyclodextrin columns. With the exception of compounds 5 and 10, all other racemates reported here which have been successfully resolved on the new phases are enantiomers which have not been previously reported as separated on the beta-cyclodextrin stationary phase. In some cases, there were also differences in enantioselectivities observed between the (S)- and the (R,S)-hydroxypropyl-beta-cyclodextrin phases on the same silica. The results are discussed in terms of the retention mechanism and compared to results reported earlier for beta-cyclodextrin columns.

[Preparation of toxoid from Taiwan cobra (Naja naja atra) venom]

Potency of sixty antitoxic unit was reached after two immunizations in 2-week intervals of rabbits and horses with 10-25 mg Taiwan cobra (Naja naja atra) venom which was detoxified by 0.125% glutaraldehyde. Now this procedure has become a routine antivenine-producing method by which snake bivalent neurotropic antivenine is produced. The stability test showed that Taiwan cobra toxoid kept at 37 degrees C for 40 days, the antigenicity increased by 24% and toxicity decreased by 10% as compared to the toxoid maintained at 4 degrees C.

Increased expression of MHC class II antigens in rejecting canine lung allografts

Expression of major histocompatibility complex class II antigens was investigated in the normal lungs and in lung allografts of mongrel dogs after single-lung transplantation. Cryostat sections were stained with an indirect immunoperoxidase technique that used B1F6 and 7.5.10.1 as anti-MHC class II monoclonal antibodies. In the normal lungs and native lungs of the recipient dogs after single-lung transplantation, only some cells of lymphoid tissue and macrophages/dendritic cells were MHC class II-positive. During acute rejection, increased infiltration with MHC class II-positive cells in perivascular, peribronchial, and interstitial areas and intraalveolar spaces was found in lung allografts. In addition, expression of MHC class II antigens was induced on the bronchial epithelium and vascular endothelium. Induced expression of MHC class II antigens on the bronchial epithelium and vascular endothelium in rejecting lung allografts was found as early as two days after single-lung transplantation. The intensity of MHC class II antigen expression on bronchial epithelium and vascular endothelium in graft lungs increased with the progression of rejection response and directly correlated with the bronchoalveolar lavage fluid (BALF) levels of biochemical markers, as tumor necrosis factor alpha, gamma-interferon (IFN-gamma), interleukin 2 (IL-2) and soluble interleukin 2 receptor (SIL-2R). Abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium and abnormal elevation of BALF levels of the cytokines in lung allografts could be prevented by cyclosporine (CsA) treatment. Our results suggested that MHC class II antigen expression could be induced on the bronchial epithelium and vascular endothelium of canine lung allografts during acute rejection. This abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium of graft lungs may serve as a specific index for diagnosis of lung allograft rejection when infection as an inducing factor can be excluded. Furthermore, bronchial epithelium and vascular endothelium of lung allografts have become MHC class II-positive, and are likely to be the targets for low-grade rejection, resulting in the development of bronchiolitis obliterans and occlusive vascular disease in lung allografts.

The effect of cyclosporine on expression of class II major histocompatibility complex antigens on bronchoalveolar cells and peripheral blood mononuclear cells

To evaluate the effect of cyclosporine (CsA) on the expression of class II major histocompatibility complex (MHC) antigens on bronchoalveolar cells (BAC) and peripheral blood mononuclear cells (PBMC), BAC and PBMC were obtained from mongrel dogs before and during CsA treatment. Expression of MHC class II antigens on BAC and PBMC were detected by monoclonal antibodies (Mabs) B1F6, 7.5.10.1 and Q5/13, which recognized canine MHC class II antigens, using cytofluorometry. Total cell counts and cell differentials of canine BAC showed no significant difference before or during CsA treatment (P greater than 0.05). Anti-MHC class II Mabs used in this study reacted with 21-51% of canine BAC and with 31-69% of PBMC. After stimulation with phytohaemagglutinin (PHA) the percentages of MHC class II positive BAC and PBMC were significantly increased (P less than 0.001). Whole blood levels of CsA were 315 +/- 76 (mean +/- SD) ng/ml and 343 +/- 57 ng/ml on days 7 and 14 during CsA treatment at an oral dose of 20 mg/kg/day. During CsA treatment there was no significant difference in the percentages of MHC class II positive BAC and PBMC compared with data obtained before CsA treatment (P greater than 0.05). We likewise failed to observe a suppressive effect of CsA on the increased expression of MHC class II antigens on BAC and PBMC induced by PHA (P greater than 0.05). In summary, at an oral dose of 20 mg/kg/day for a period of two weeks, our results show that: (1) CsA does not affect the total cell counts and cell differentials of canine BAC; (2) CsA does not reduce the basal expression of MHC class II antigens on canine BAC and PBMC; (3) CsA does not suppress the increased expression of MHC class II antigens on canine BAC and PBMC induced by PHA.