Thein vitro inactivation of thirteen β-lactam antibiotics by other mechanisms than adsorption to faecal substance

Summary We have investigated the antibiotic inactivating capacity of intestinal contentsin vitro in faeces. In the presently reported study the influence of -lactamase catalyzed hydrolysis on the antimicrobial activity of 13 commonly used -lactam antibiotics was investigated, while the influence of non-specific adsorption of antibiotics to faecal compounds was also taken into account. The following antibiotics were tested: benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin, temocillin, cefuroxime, cefamandole, cephradine, cefotaxime, ceftazidime, aztreonam and imipenem. Faecal samples were obtained from 30 healthy volunteers. Six different concentrations of each antibiotic were added to 1 g of faeces. After 24 h of incubation at 37°C the remaining amount of active antibiotic was determined by means of a growth inhibition assay. The contribution to the test results of non-specific adsorption to macromolecules was calculated by means of a model and the inactivation data were subsequently corrected. The amount of antibiotic non-specifically bound to faecal macromolecules varied from 0% to 80% of the amount of antibiotic initially added to the faeces. A considerable difference was found in the degree of inactivation of several antibiotics. However, in contrast to earlier investigations, the results of this study show that in a normal population the influence of -lactamase catalyzed hydrolysis on the activity of -lactam antibiotics is apparently very small when compared to the influence of non-specific adsorption of -lactam antibiotics to faecal compounds.

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Inaktivierung von 13 -Laktamantibiotika durch Mechanismen, die nicht auf Adsorption durch Bestandteile der Faeces zurückzuführen sind

Zusammenfassung Die Fähigkeit des Darminhaltes, Antibiotika zu inaktivieren, wurdein vitro untersucht. In der vorliegenden Studie wurde neben der unspezifischen Adsorption von Antibiotika an Stuhlbestandteile vor allem der Einfluß der -Laktamase-vermittelten Hydrolyse auf die anti-mikrobielle Aktivität von 13 gebräuchlichen -Laktamantibiotika untersucht (Benzylpenicillin, Amoxicillin, Amoxicillin/Clavulansäure, Cloxacillin, Piperacillin, Temocillin, Cefuroxim, Cefamandol, Cephradin, Cefotaxim, Ceftazidim, Aztreonam und Imipenem). Die Stuhlproben wurden von 30 gesunden Probanden gewonnen. Jedes Antibiotikum wurde in sechs verschiedenen Konzentrationen jeweils zu 1 g Faeces gegeben. Nach 24 h Inkubationszeit bei 37°C wurde mittels Wachstumshemmtest die Restaktivität des Antibiotikums bestimmt. Die Ergebnisse wurden mit dem Faktor der unspezifischen Adsorption an Makromoleküle (Berechnung nach entsprechendem Modell) korrigiert. Von der ursprünglich zugegebenen Antibiotikamenge wurden 0 bis 80% unspezifisch an Makromoleküle der Faeces gebunden. Zwischen dem Inaktivierungsgrad der Antibiotika bestanden beträchtliche Unterschiede. Im Vergleich zur unspezifischen Adsorption an Stuhlbestandteile erwies sich in dieser Studie — im Gegensatz zu früheren Untersuchungen — der Einfluß der Hydrolyse durch -Laktamasen auf die Antibiotikaaktivität bei gesunden Personen als sehr gering.

     

Sensor histidine kinase is a β-lactam receptor and induces resistance to β-lactam antibiotics

β-Lactams disrupt bacterial cell wall synthesis, and these agents are the most widely used antibiotics. One of the principle mechanisms by which bacteria resist the action of β-lactams is by producing β-lactamases, enzymes that degrade β-lactams. In Gram-negative bacteria, production of β-lactamases is often induced in response to the antibiotic-associated damage to the cell wall. Here, we have identified a previously unidentified mechanism that governs β-lactamase production. In the Gram-negative enteric pathogen Vibrio parahaemolyticus, we found a histidine kinase/response regulator pair (VbrK/VbrR) that controls expression of a β-lactamase. Mutants lacking either VbrK or VbrR do not produce the β-lactamase and are no longer resistant to β-lactam antibiotics. Notably, VbrK autophosphorylation is activated by β-lactam antibiotics, but not by other lactams. However, single amino acid substitutions in the putative periplasmic binding pocket of VbrK leads its phosphorylation in response to both β-lactam and other lactams, suggesting that this kinase is a β-lactam receptor that can directly detect β-lactam antibiotics instead of detecting the damage to cell wall resulting from β-lactams. In strong support of this idea, we found that purified periplasmic sensor domain of VbrK binds penicillin, and that such binding is critical for VbrK autophosphorylation and β-lactamase production. Direct recognition of β-lactam antibiotics by a histidine kinase receptor may represent an evolutionarily favorable mechanism to defend against β-lactam antibiotics.The β-lactams are the most widely used and among the most valuable classes of antibiotics (1). These agents contain a β-lactam ring in their structures and inhibit the activity of transpeptidases or penicillin binding proteins (PBPs), the essential enzymes for the biosynthesis of peptidoglycan (PG) (2, 3), thereby damaging the integrity of bacterial cell wall. One of the principal mechanisms by which bacteria develop resistance to β-lactam antibiotics is the production of intrinsic or horizontally acquired β-lactamases that can degrade and inactivate β-lactams (4).In many bacterial species, β-lactamase expression is inducible in response to β-lactam antibiotic treatment. For example, in Gram-positive bacteria, β-lactamase can be induced directly by β-lactam antibiotics or indirectly by muropeptides that are released from PG after β-lactam treatment (5). In Gram-negative bacteria (e.g., Enterobacteriaceae), muropeptide produced after β-lactam treatment can also induce the expression β-lactamase (6, 7). In addition to β-lactam treatment, β-lactamase expression in Gram-negative bacteria can also be induced by the changes of growth rate (8, 9). The direct role of β-lactam in inducing the expression of β-lactamase in Gram-negative bacteria has not been reported.Two-component systems (TCSs), which are typically composed of a sensor histidine kinase (HK) and a response regulator (RR), are widely present in many bacterial species (10, 11). Typically, environmental signals are sensed by histidine kinase, leading to its autophosphorylation and subsequent phosphoryl transfer to its cognate response regulator (12, 13). Upon phosphorylation, a response regulator usually controls the expression of genes for adaptation to changing environment. Certain TCSs have been shown to contribute to antibiotic (e.g., glycopeptide) resistance. For example, VanS, the histidine kinase of VanSR TCS, directly binds to vancomycin, leading to the expression of genes that are required for the synthesis of alternate peptidoglycan precursors that have low affinity for vancomycin (14–16). Histidine kinases also contribute to the resistance to the antimicrobial peptides, e.g., LL-37, which activates the histidine kinase PhoQ by directly binding to the acidic surface of the PhoQ periplasmic domain (17). TCSs (e.g., BlrAB in Aeromonas or CreBC in Escherichia coli and Pseudomonas) have also been shown to be involved in the expression of β-lactamase and thus are important for β-lactam resistance (3, 9, 18). The response regulator of BlrAB or CreBC triggers the expression of β-lactamase by recognizing the signature sequences (cre/blr-tag: TTCACnnnnnnTTCAC) located in the promoter of β-lactamase gene (3, 9, 18). Despite the evidence that TCS plays an important role in the induction of β-lactamase expression, the identity of the cues that are recognized and transmitted by TCS to control β-lactamase expression remain completely unknown (19).Here, we reported a previously unidentified mechanism that governs β-lactamase production in Gram-negative bacterium Vibrio parahaemolyticus, the leading cause of seafood-borne diarrheal disease worldwide. Most isolates of V. parahaemolyticus from both clinical and environmental settings exhibit resistance to β-lactam antibiotics, thereby limiting treatment options. At the time we initiated these studies, there was minimal knowledge of the mechanisms underlying V. parahaemolyticus resistance to β-lactam antibiotics. However, a recent report revealed that essentially all V. parahaemolyticus isolates encode a class A chromosomal carbenicillin-hydrolyzing (CARB) β-lactamase (bla_V110) (20). We independently identified this chromosome II-encoded enzyme as part of the regulon of a novel TCS (VbrK/VbrR) that controls V. parahaemolyticus resistance to β-lactam antibiotics. Notably, we show that the sensor histidine kinase, VbrK, in this system detects β-lactam antibiotics via direct binding and transmits the signal to the response regulator, VbrR, to control the expression of this CARB β-lactamase gene.     

Relationship between the β-galactosidase activity in saliva and parameters associated with oral malodor

Volatile sulfur compounds (VSCs) are produced by enzymes capable of transforming S-amino acids to corresponding sulfides. Protein degradation by periodontopathogens plays an important role in this process, and the proteolysis of glycoproteins depends on the initial removal of the carbohydrate side chains. In the present report, we tested the relationship between the β-galactosidase activity in saliva and parameters that influence oral malodor, including daily habits and oral conditions. The prevalence of periodontopathic bacteria was also examined. Forty-nine saliva samples were collected from halitosis patients. Patients were examined for breath odor and other associated parameters. Their breath odor was assessed using an organoleptic test, a portable sulfide monitor and gas chromatography. The presence of periodontopathic bacteria in the saliva was also examined. β-galactosidase activity was measured with the chromogenic substrates 5-bromo-4-chloro-3-indoyl-β-d-galactopyranoside and isopropyl-β-d-thiogalactopyranoside. β-galactosidase activity was positively correlated with malodor strength (organoleptic score, portable sulfide monitor score and VSC concentrations). Enzyme activity was also correlated with the degree of observable tongue coating. However, it showed no relationship with periodontal condition, saliva flow, tooth decay, unfitted restorations or the color of any tongue coating. While there was no relationship with Porphyromonas gingivalis and Treponema denticola, there was a negative correlation with Prevotella intermedia. These results indicate that β-galactosidase activity plays an important role in malodor production. Interestingly, the activity of this enzyme was not related to the presence of periodontopathic bacteria, which are the main malodor-producing organisms. The results obtained here may have been associated with physiologic halitosis, which is not necessarily associated with oral problems or with periodontopathic bacteria.     

In vitro activity of cefpirome against selected clinical enterobacterial isolates with β-lactamase-mediated resistance

Summary Previous studies have shown that there is a high incidence of resistance to cephalosporins among enterobacteria isolated in Greek hospitals. This resistance is mainly due to either the derepression of chromosomal cephalosporinases or the acquisition of plasmids coding for SHV-5 type -lactamase. In the present study the activity of cefpirome against a number of enterobacteria (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes andSerratia marcescens) possessing the mechanisms mentioned above was examined. Cefpirome was found active against all the strains characterized by stable derepression of chromosomal class-C enzymes. The antibiotic was less potent against strains expressing SHV-5 type -lactamase due to its hydrolysis by the enzyme. Also cefpirome exhibited good activity againstE. aerogenes strains with reduced susceptibility to imipenem. Thesein vitro data suggest that cefpirome might be useful in treating infections caused by these resistant microorganisms that are frequently encountered in Greek hospitals.

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In-vitro-Aktivität von Cefpirom gegen ausgewählte klinische Isolate von Enterobakterien mit -Laktamase-bedingter Resistenz

Zusammenfassung Frühere Studien haben gezeigt, daß die Resistenzrate von Enterobakterien-Isolaten aus griechischen Krankenhäusern gegen Cephalosporine hoch ist. Diese Resistenz beruht im wesentlichen auf der Derepression chromosomaler Cephalosporinasen oder dem Erwerb von Plasmiden, die für eine -Laktamase vom Typ SHV-5 kodieren. In der vorliegenden Studie wurde die Aktivität von Cefpirom gegen eine Reihe von Enterobakterien (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes undSerratia marcescens) mit den obengenannten Resistenzmechanismen geprüft. Cefpirom erwies sich als wirksam gegen alle Stämme, die durch eine stabile Derepression der chromosomal kodierten Klasse-C-Enzyme charakterisiert waren. Das Antibiotikum war gegen Stämme mit Expression einer -Laktamase vom Typ SHV-5 weniger aktiv, da es durch dieses Enzym hydrolysiert wurde. Cefpirom zeigte auch gute Aktivität gegen Stämme vonE. aerogenes, mit verminderter Empfindlichkeit gegen Imipenem. DieseIn-vitro-Daten lassen darauf schließen, daß Cefpirom sich für die Behandlung von Infektionen durch diese resistenten Erreger eignet, die in griechischen Krankenhäusern häufig zu finden sind.

     

Utility of serum CA19-9 in diagnosis of cholangiocarcinoma:In comparison with CEA

AIM:The diagnosis of cholangiocarcinoma is often difficult,making management approaches problematic.A reliableserum marker for cholangiocarcinoma would be a usefuldiagnostic test.The aims of our study were to evaluate theusefulness of a serum CA19-9 determination in the diagnosisof cholangiocarcinoma.METHODS:We prospectively measured serum CA19-9 andCEA concentrations in patients with cholangiocarcinoma(n=35),benign biliary diseases (n=92),and healthyindividuals (n=15).Serum CA19-9 and CEA concentrationswere measured by an immunoradiometric assay withoutknowledge of the clinical diagnosis.RESULTS:The sensitivity of a CA19-9 value >37 KU·L~(-1)and a CEA value >22 μg·L~(-1) in diagnosing cholangiocarcinomawere 77.14% and 68.57%,respectively.When comparedwith the benign biliary diseases group,the true negativerates of serum CA19-9 and CEA were 84.78% and 81.52%,respectively.The false positive rates of serum CA19-9 andCEA were 15.22% and 18.48%,whereas the accuracy ofserum CA19-9 and CEA were 82.68% and 77.95%,respectively.Serum CA19-9 and CEA concentrations weresignificantly elevated (P<0.001 and P<0.05) in patients withcholangiocarcinoma (290.31±5.34 KU·L~(-1) and 36.46±18.03μg·L~(-1)) compared with patients with benign biliary diseases(13.38±2.59 KU·L~(-1) and 13.84±3.85 μg·L~(-1)) and healthyindividuals (12.78±3.69 KU·L~(-1) and 11.48±3.37 μg·L~(-1)).In 15patients undergoing curative resection of cholangiocarcinoma,the mean serum CA19-9 concentration was decreased froma preoperative level of 286.41±4.36 KU·L~(-1) to a postoperativelevel of 62.01±17.43 KU·L~(-1) (P<0.001),and the mean serumCEA concentration from 39.41±24.35 μg·L~(1) to 28.69±11.03μg·L~(-1)(P<0.05).In patients with cholangiocarcinoma,however,no correlation was found between serum CEA andCA19-9 concentrations (r=0.036).CONCLUSION:These data suggest that the serum CA19-9determination is a useful addition to the available tests for thedifferential diagnosis of cholangiocarcinoma.Serum CA19-9 isan effective tumor marker in diagnosing cholangiocarcinoma,deciding whether the tumor has been radically resected andmonitoring effect of treatment.     

Utility of serum CA19-9 in diagnosis of cholangiocarcinoma： In comparison with CEA

AIM:The diagnosis of cholangiocarcinoma is often difficult,making management approaches problematic. A reliable serum marker for cholangiocarcinoma would be a useful diagnostic test. The aims of our study were to evaluate the usefulness of a serum CA19-9 determination in the diagnosis of cholangiocarcinoma.METHODS: We prospectively measured serum CA19-9 and CEA concentrations in patients with cholangiocarcinoma (n=35), benign biliary diseases (n=92), and healthy individuals (n=15). Serum CA19-9 and CEA concentrations were measured by an immunoradiometric assay without knowledge of the clinical diagnosis.RESULTS:The sensitivity of a CA19-9 value&gt;37KU&#183;L^-1 and a CEA value &gt;22μg&#183;L^-1 in diagnosing cholangiocarcinoma were 77.14% and 68.57%, respectively. When compared with the benign biliary diseases group,the true negative rates of serum CA19-9 and CEA were 84.78% and 81.52%,respectively. The false positive rates of serum CA19-9 and CEA were 15.22% and 18.48%, whereas the accuracy of serum CA19-9 and CEA were 82.68% and 77.95%,respectively. Serum CA19-9 and CEA concentrations were significantly elevated (P&lt;0.001 and P&lt;0.05) in patients with cholangiocarcinoma (290.31&#177;5.34KU&#183;L^-1 and 36.46&#177;18.03μg&#183;L^-1) compared with patients with benign biliary diseases (13.38&#177;2.59KU&#183;L^-1 and 13.84&#177;3.85μg&#183;L^-1) and healthy individuals (12.78&#177;3.69KU&#183;L^-1 and 11.48&#177;3.37μg&#183;L^-1). In 15 patients undergoing curative resection of cholangiocarcinoma,the mean serum CA19-9 concentration was decreased from a preoperative level of 286.41&#177;4.36KU&#183;L^-1 to a postoperative level of 62.01&#177;17.43KU&#183;L^-1 (P&lt;0.001), and the mean serum CEA concentration from 39.41&#177;24.35μg&#183;L^-1 to 28.69&#177;11.03μg&#183;L6-1(P&lt;0.05). In patients with cholangiocarcinoma,however, no correlation was found between serum CEA and CA19-9 concentrations (r=-0.036).CONCLUSION:These data suggest that the serum CA19-9 determination is a useful addition to the available tests for the differential diagnosis of cholangiocarcinoma. Serum CA19-9 is an effective tumor marker in diagnosing cholangiocarcinoma,deciding whether the tumor has been radically resected and monitoring effect of treatment.     

Effect of an oral β2-adrenoceptor agonist in a patient with idiopathic interstitial pneumonia

A 63-year-old man was referred to our hospital because of a dry cough. His chest roentgenogram revealed ground-glass opacities and honeycomb formations bilaterally in the lower lung fields. Pulmonary function tests showed a depleted lung volume and decreased arterial oxygen tension. He was clinically diagnosed as having idiopathic interstitial pneumonia (IIP). A β₂-adrenoceptor agonist was administrated because the patient's symptoms improved after its inhalation. Following treatment with an oral β₂-adrenoceptor agonist, the dry cough disappeared, lung function tests remained unchanged and an improvement in arterial oxygen tension was observed. Although β₂-adrenoceptor agonist therapy does not improve disease activity or progression in patients with IIP, its use may mitigate symptoms associated with the disease.     

Lipoprotein-associated phospholipase A₂ activity is increased in patients with definite familial hypercholesterolemia compared with other forms of hypercholesterolemia

Background and Aim

Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) plays a key role in atherosclerosis development. It is considered a marker of increased risk of cardiovascular disease (CVD) and plaque vulnerability. Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol and a higher prevalence of early CVD.Our aim was to evaluate the differences in Lp-PLA₂ activity in a population of hypercholesterolemic patients with and without definite FH.

Increased levels of thymosin β4 in synovial fluid of patients with rheumatoid arthritis: association of thymosin β4 with other factors that are involved in inflammation and bone erosion in joints

Aim: Thymosin (Tβ4) may have various biological effects that are relevant to the pathogenesis of rheumatoid arthritis (RA). This study was performed to gain insight into the relevance of Tβ4 in the pathogenesis of inflammatory arthritis. Method: The level of Tβ4 in synovial fluid from patients with osteoarthritis (OA) or RA was measured by enzyme‐linked immunosorbent assay. An association between Tβ4 and matrix metalloproteinase (MMP)‐1 and MMP‐13 (collagenases), MMP‐2 and MMP‐9 (gelatinases), MMP‐7, adiponectin, lactoferrin, vascular endothelial growth factor (VEGF), urokinase‐type plasminogen activator (uPA), interleukin (IL)‐6, IL‐8 and prostaglandin E2 (PGE₂) in synovial joint fluids from OA and RA patients were investigated. Results: The level of Tβ4 in the synovial joint fluid of patients with OA and RA was (mean ± SD) 145 ± 88 and 1359 ± 1685 ng/mL, respectively. The level of Tβ4 in the synovial joint fluid of RA patients was significantly associated with the levels of MMP‐9, MMP‐13, VEGF, uPA, IL‐6 and IL‐8, but not with MMP‐1, MMP‐2, MMP‐7, adiponectin and lactoferrin. In contrast, the level of Tβ4 in the synovial joint fluid of patients with OA was not associated with any of these molecules. Conclusions: The results suggest that Tβ4 may play an important role in bone degradation and inflammation in RA but not OA, although nothing is known about the molecular mechanisms mediating Tβ4 in arthritic joints. The role of Tβ4 in arthritis should be studied to understand its relevance to the pathogenic processes in arthritis.     

In vitro assessment of the anti-biofilm activity of ethanol alone and in combination with enoxaparin 60 IU

Introduction

Catheter-related bloodstream infection (C-RBSI) can sometimes be managed without catheter removal by combining systemic therapy with catheter lock therapy. Most antiseptic lock solutions are made up of ethanol combined with an anticoagulant. However, data regarding the anti-biofilm activity of ethanol combined with enoxaparin are scarce. We aimed to assess the efficacy of ethanol at different concentrations combined with enoxaparin 60 IU as a lock solution for eradication of the biofilm of different microorganisms.

In vitro activity of cefpodoxime and ten other cephalosporins against gram-positive cocci,enterobacteriaceae and pseudomonas aeruginosa,including β-lactamase producers

Summary Cefpodoxime, the deesterified part of the orally available cefpodoxime proxetil, is active against mostEnterobacteriaceae with MIC₅₀ of 0.06 to 2 mg/l. OnlyEnterobacter cloacae andCitrobacter freundii strains show MIC₅₀ of 4 mg/l. Coagulase negative staphylococci have a MIC₅₀ of 2, whileStaphylococcus aureus strains have a MIC of 4 mg/l. In comparison to other orally available cephalosporins cefpodoxime is slightly less active than cefixime and cefotiam against gram-negative bacteria but more active than cefuroxime, cefaclor, and cephalexin. Against staphylococci the activity of cefpodoxime is comparable to that of cefotiam and cefuroxime and superior to cefaclor and cephalexin, while cefixime does not have sufficient activity against these species. Like all cephalosporins cefpodoxime has no activity against enterococci.

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In-vitro-Aktivität von Cefpodoxim und zehn anderen Cephalosporinen gegen grampositive Kokken, Enterobacteriaceae und Pseudomonas aeruginosa einschließlich -Laktamase-Bildnern

Zusammenfassung Cefpodoxim entsteht durch Spaltung des Esters aus dem resorbierbaren Cefpodoxim-Proxetil und ist gegen die meistenEnterobacteriaceae mit MHK₅₀-Werten von 0,06 bis 2 mg/l aktiv. Nur Stämme vonEnterobacter cloacae undCitrobacter freundii zeigen MHK₅₀-Werte von 4 mg/l. Coagulase negative Staphylokokken haben eine MHK₅₀ von 2, währendStaphylococcus aureus-Stämme eine MHK von 4 mg/l aufweisen. Im Vergleich mit anderen oral verfügbaren Cephalosporinen ist Cefpodoxim gegen gramnegative Bakterien etwas weniger aktiv als Cefixim und Cefotiam, aber aktiver als Cefuroxim, Cefaclor und Cephalexin. Gegen Staphylokokken ist die Aktivität von Cefpodoxim mit der von Cefotiam und Cefuroxim vergleichbar und der von Cefaclor und Cephalexin überlegen, während Cefixim keine ausreichende Aktivität gegen diese Spezies hat. Wie alle Cephalosporine weist Cefpodoxim keine Aktivität gegen Enterokokken auf.

     

Prenatal diagnosis of β-thalassemia and other hemoglobinopathies in southwestern Turkey

Our aim was to evaluate the prenatal diagnosis of β-thalassemia (β-thal) and other hemoglobinopathies in a region with high frequency. After detection by premarital or antenatal screening, 312 patients underwent 420 prenatal diagnostic procedures for 407 fetuses in a 10-year period. Fetal samples were collected by chorionic villi sampling (CVS) in the first trimester and amniocentesis and cordocentesis in the second trimester. Mutation analyses of β-globin and cytogenetic analyses were performed and the most common mutations detected were: IVS-I-110 (G>A), IVS-II-1 (G>A), IVS-I-6 (T>C) and IVS-II-745 (C>G). Hb S [β6(A3)Glu→Val, GAG>GTG)] was the most common hemoglobin (Hb) variant with a frequency of 6.3%. Among 407 fetuses, 105 (25.8%) were diagnosed as affected, while 201 (49.4%) were carriers and 101 (24.8%) were normal. Cytogenetic analyses revealed nine fetuses (2.3%) with numerical chromosomal abnormalities as regular or mosaicism. Prenatal diagnosis of common hemoglobinopathies is safe and effective. Performing cytogenetic analysis in excess fetal material is an acceptable option.     

Vascular Effects of Aqueous Extract of Chamaemelum nobile : In Vitro Pharmacological Studies in Rats

This study aims to evaluate the in vitro vasorelaxant effect of C. nobile aqueous extract. We use aortic ring isolated from Wistar rats and aqueous C. nobile extract at doses of 5, 10 and 20 mg/ml. Incubation of aqueous C. nobile extract for 30 minutes produced a significant shift of the dose–response curve to norepinephrine (NE) (10^–8 to 10^–5 M) (p < 0.001). This study demonstrates that aqueous C. nobile extract possesses in vitro vasorelaxant effect.     

A comparison of intensive mixture therapy with basal insulin therapy in insulin-naïve patients with type 2 diabetes receiving oral antidiabetes agents

Aim: In patients with type 2 diabetes, insulin therapy is commonly initiated with either a single dose of basal insulin or twice‐daily premixed (basal plus prandial) insulin despite no widely accepted recommendation. We compared the glycaemic control, as measured by a change in HbA1c, of intensive mixture therapy (IMT), a basal plus prandial regimen using insulin lispro mixture 50/50 (50% lispro and 50% NPL) before breakfast and lunch and insulin lispro mixture 25/75 (25% lispro and 75% NPL) before dinner, vs. once‐daily insulin glargine therapy, while continuing patients on oral antidiabetes medications. Methods: Following inadequate glycaemic control (HbA1c 1.2–2.0 times the upper limit of normal) and at least 2 months of two or more oral antidiabetes agent therapy, 60 insulin‐naïve patients with type 2 diabetes were randomized to one of the insulin regimens for 4 months with crossover to the alternative regimen for an additional 4 months. Glycaemic goals were preprandial blood glucose <120 mg/dl (6.7 mmol/l) and 2‐h postprandial blood glucose <180 mg/dl (10.0 mmol/l). The insulin dose was optimized by investigators without forced titration. Results: Mean prestudy (baseline) HbA1c for all patients was 9.21 ± 1.33% (±s.d.). IMT compared to glargine resulted in both a lower endpoint in HbA1c (7.08 ± 0.11% vs. 7.34 ± 0.11%; p = 0.003) and a greater change in HbA1c from pretherapy (?1.01 ± 0.10% vs. ?0.75 ± 0.10%; p = 0.0068). Forty‐four per cent of patients receiving IMT and 31% of patients receiving insulin glargine achieved HbA1c ≤ 7%. Two‐hour postprandial glucose values (for all three meals) and predinner glucose values were significantly less with IMT than with insulin glargine (p = 0.0034, 0.0001, 0.0066 and 0.0205). Overall hypoglycaemia throughout the complete treatment period was infrequent (IMT vs. Glargine: 3.98 ± 4.74 vs. 2.57 ± 3.22 episodes/patient/30 days, p = 0.0013), and no severe hypoglycaemia was observed during the study with either therapy. There was no difference in nocturnal hypoglycaemia between the two therapies. The mean insulin dose at the end of therapy was greater for IMT than for once‐daily insulin glargine (0.353 ± 0.256 vs. 0.276 ± 0.207 IU/kg, p = 0.0107). Conclusions: In combination with oral antidiabetes agents, multiple daily injections of a basal plus prandial insulin IMT regimen (using premixed insulin lispro formulations) resulted in greater improvements and a lower endpoint in HbA1c compared with a basal‐only insulin regimen. IMT also resulted in improved postprandial blood glucose control at each meal and enabled administration of a greater daily dose of insulin, which most likely contributed to these lower HbA1c measures. This greater reduction in HbA1c with IMT is accompanied by a small increased occurrence of mild hypoglycaemia but without any severe hypoglycaemia. Greater consideration should be given to initiating insulin as a basal plus prandial regimen rather than a basal‐only regimen.