Gram staining of protected pulmonary specimens in the early diagnosis of ventilator-associated pneumonia

We evaluated prospectively the use of Gram staining of protected pulmonary specimens to allow the early diagnosis of ventilator-associated pneumonia (VAP), compared with the use of 60 bronchoscopic protected specimen brushes (PSB) and 126 blinded plugged telescopic catheters (PTC) obtained from 134 patients. Gram stains were from Cytospin slides; they were studied for the presence of microorganisms in 10 and 50 fields by two independent observers and classified according to their Gram stain morphology. Quantitative cultures were performed after serial dilution and plating on appropriate culture medium. A final diagnosis of VAP, based on a culture of > or = 10(3) c.f.u. ml-1, was established after 81 (44%) samplings. When 10 fields were analysed, a strong relationship was found between the presence of bacteria on Gram staining and the final diagnosis of VAP (for PSB and PTC respectively: sensitivity 74 and 81%, specificity 94 and 100%, positive predictive value 91 and 100%, negative predictive value 82 and 88%). The correlation was less when we compared the morphology of microorganisms observed on Gram staining with those of bacteria obtained from quantitative cultures (for PSB and PTC respectively: sensitivity 54 and 69%, specificity 86 and 89%, positive predictive value 72 and 78%, negative predictive value 74 and 84%). Increasing the number of fields read to 50 was associated with a slight decrease in specificity and positive predictive value of Gram staining, but with a small increase in its sensitivity and negative predictive value. The results obtained by the two observers were similar to each other for both numbers of fields analysed. Gram staining of protected pulmonary specimens performed on 10 fields predicted the presence of VAP and partially identified (using Gram stain morphology) the microorganisms growing at significant concentrations, and could help in the early choice of the treatment of VAP. Increasing the number of fields read or having the Gram stain analysed by two independent individuals did not improve the results.

Oxidation, nitrosation, and nitration of serotonin by nitric oxide-derived nitrogen oxides: biological implications in the rat vascular system

Because NO is not very reactive in an oxygen-free buffer, a significant part of serotonin (5-HT) is transformed by NO in nondeaerated phosphate buffer, at pH 7.4, into (4-serotonyl)-4-serotonin, 4-nitrososerotonin, and 4-nitroserotonin. Dimerization and above all nitrosation occur through the HNO2 reaction in the pH 4-6 range, possibly via radical mechanism involving N2O3. 5-HT is readily a substrate for nitrosation by HNO2 or N2O3, whereas tyrosine was described as not very reactive under the same conditions. Peroxynitrite converts 5-HT to the (4-serotonyl)-4-serotonin and to the 4-nitro derivative. In order to evaluate whether such structural modifications could modulate the biological properties of 5-HT, arterial pressure was measured after i.v. bolus injection of these derivatives to anesthetized rats. Injections of the 4-nitroso- and 4-nitro-5-HT resulted in first a brief hypotensive response and did not give the subsequent hypertensive and hypotensive phases observed with 5-HT. Finally, when tested on some cloned rat 5-HT receptors stably transfected into LMTK- cells, both 4-nitroso and 4-nitro derivatives behaved as agonists and antagonists toward 5-HT1B and 5-HT2B receptors, respectively.

Prevalence of hypertension in patients attending Al-Kharj Military Hospital

OBJECTIVE

This study was carried out to ascertain the prevalence of hypertension in our community with a view to forming a baseline and planning strategies for prevention and control.

METHODS

A cross sectional study carried out by collecting data from randomly selected case notes of 3747 patients (1683 males and 2064 females), regarding age, sex, blood pressure measurements and whether or not they were on treatment for hypertension.

RESULTS

The prevalence of hypertension in the total population was 3.1% (females 3.05% and males 2.67%). With regard to age group, the prevalence was highest in 65-74 years in both males and females.

CONCLUSION

There is a need for health education among our patients regarding the nature of hypertension and the relation between life style and hypertensive disease.

Celecoxib does not significantly alter the pharmacokinetics or hypoprothrombinemic effect of warfarin in healthy subjects

The objective of this study was to determine the effects of celecoxib, an anti-inflammatory/analgesic agent that primarily inhibits COX-2 and not COX-1 at therapeutic doses, on the steady-state pharmacokinetic profile and hypoprothrombinemic effect of racemic warfarin in healthy volunteers. Twenty-four healthy adult volunteers on maintenance doses of racemic warfarin (2-5 mg daily), stabilized to prothrombin times (PT) 1.2 to 1.7 times pretreatment PT values for 3 consecutive days, were randomized to receive concomitant celecoxib (200 mg bid) or placebo for 7 days in an open-label, multiple-dose, randomized, placebo-controlled, parallel-group study of warfarin pharmacokinetics and PT. Steady-state exposure of S- and R-warfarin (area under the curve [AUC]) and maximum plasma concentration (Cmax) in subjects receiving celecoxib were within 2% to 8% of the warfarin AUC and Cmax in subjects receiving placebo during the concomitant treatment period. In addition, PT values were not significantly different in subjects receiving warfarin and celecoxib concomitantly compared with subjects receiving warfarin and placebo. In conclusion, concomitant administration of celecoxib has no significant effect on PT or steady-state pharmacokinetics of S- or R-warfarin in healthy volunteers.

Biochemical-genetic characterization and regulation of expression of an ACC-1-like chromosome-borne cephalosporinase from Hafnia alvei

A naturally occurring AmpC beta-lactamase (cephalosporinase) gene was cloned from the Hafnia alvei 1 clinical isolate and expressed in Escherichia coli. The deduced AmpC beta-lactamase (ACC-2) had a pI of 8 and a relative molecular mass of 37 kDa and showed 50 and 47% amino acid identity with the chromosome-encoded AmpCs from Serratia marcescens and Providentia stuartii, respectively. It had 94% amino acid identity with the recently described plasmid-borne cephalosporinase ACC-1 from Klebsiella pneumoniae, suggesting the chromosomal origin of ACC-1. The hydrolysis constants (k(cat) and K(m)) showed that ACC-2 was a peculiar cephalosporinase, since it significantly hydrolyzed cefpirome. Once its gene was cloned and expressed in E. coli (pDEL-1), ACC-2 conferred resistance to ceftazidime and cefotaxime but also an uncommon reduced susceptibility to cefpirome. A divergently transcribed ampR gene with an overlapping promoter compared with ampC (bla(ACC-2)) was identified in H. alvei 1, encoding an AmpR protein that shared 64% amino acid identity with the closest AmpR protein from P. stuartii. beta-Lactamase induction experiments showed that the ampC gene was repressed in the absence of ampR and was activated when cefoxitin or imipenem was added as an inducer. From H. alvei 1 cultures that expressed an inducible-cephalosporinase phenotype, several ceftazidime- and cefpirome-cross-resistant H. alvei 1 mutants were obtained upon selection on cefpirome- or ceftazidime-containing plates, and H. alvei 1 DER, a ceftazidime-resistant mutant, stably overproduced cephalosporinase. Transformation of H. alvei 1 DER or E. coli JRG582 (ampDE mutant) harboring ampC and ampR from H. alvei 1 with a recombinant plasmid containing ampD from E. coli resulted in a decrease in the MIC of beta-lactam and recovery of an inducible phenotype for H. alvei 1 DER. Thus, AmpR and AmpD proteins may regulate biosynthesis of the H. alvei cephalosporinase similarly to other enterobacterial cephalosporinases.

Hardness and ultrasonic characteristics of the human crystalline lens

PURPOSE

To evaluate the relationship between hardness of the human crystalline lens and its acoustic characteristics.

SETTING

St. George's Hospital Medical School, University of London, London, United Kingdom.

METHODS

Cataractous lenses from patients who had extracapsular cataract surgery were studied for hardness and ultrasonic characteristics. Lens hardness was assessed with an automated guillotine. Ultrasound velocity and attenuation were measured with a scanning acoustic macroscope using the pulse transmission reflection method.

RESULTS

Thirty-seven lenses from 37 patients (mean age 75.5 years) were evaluated. Lens hardness was associated with ultrasound attenuation (r = 0.65, P <.0001) and attenuation frequency gradient (r = 0.67, P <.0001). The correlation of hardness with mean ultrasound velocity was not significant (r = 0.22, P =.2).

CONCLUSIONS

The attenuation of ultrasound waves by the human crystalline lens correlated with its hardness. Ultrasonography can be used to evaluate lens hardness.

Prevalence of diabetes mellitus in a Saudi community

OBJECTIVE

The aim of this retrospective cross sectional study is to find out the prevalence of Diabetes Mellitus according to age and sex in the population attending the family and community medicine clinic in Al-Kharj Armed Forces Hospital.

METHODS

Total eligible patients of Al-Kharj Military Hospital are about 100,000. The case notes in Medical Records were selected randomly and examined. Data was collected from 3747 case notes. They were divided into different age groups and also separated into male and female groups.

RESULTS

The prevalence of Diabetes Mellitus in this study sample of 3747 (1,683 males and 2,064 females) was 2.55% in males and 5.32% in females. In the age group of 35 and above the prevalence in males was 8.52% and in females 19.48%.

CONCLUSION

A high prevalence of Diabetes Mellitus was noted in the population and particularly in females. There is need for comprehensive programs for the prevention of Diabetes Mellitus particularly in the adult population.

Tumor-selective gene transduction and cell killing with an oncotropic autonomous parvovirus-based vector

A recombinant MVMp of the fibrotropic strain of minute virus of mice (MVMp) expressing the chloramphenicol acetyltransferase reporter gene was used to infect a series of biologically relevant cultured cells, normal or tumor-derived, including normal melanocytes versus melanoma cells, normal mammary epithelial cells versus breast adenocarcinoma cells, and normal neurons or astrocytes versus glioma cells. As a reference cell system we used normal human fibroblasts versus the SV40-transformed fibroblast cell line NB324K. After infection, we observed good expression of the reporter gene in the different tumor cell types, but only poor expression if any in the corresponding normal cells. We also constructed a recombinant MVMp expressing the green fluorescent protein reporter gene and assessed by flow cytometry the efficiency of gene transduction into the different target cells. At a multiplicity of infection of 30, we observed substantial transduction of the gene into most of the tumor cell types tested, but only marginal transduction into normal cells under the same experimental conditions. Finally, we demonstrated that a recombinant MVMp expressing the herpes simplex virus thymidine kinase gene can, in vitro, cause efficient killing of most tumor cell types in the presence of ganciclovir, whilst affecting normal proliferating cells only marginally if at all. However, in the same experimental condition, breast tumor cells appeared to be resistant to GCV-mediated cytotoxicity, possibly because these cells are not susceptible to the bystander effect. Our data suggest that MVMp-based vectors could prove useful as selective vehicles for anticancer gene therapy, particularly for in vivo delivery of cytotoxic effector genes into tumor cells.

The influence of reduced liver blood flow on the pharmacokinetics and pharmacodynamics of recombinant tissue factor pathway inhibitor

OBJECTIVES

Recombinant tissue factor pathway inhibitor (rTFPI) has been shown to be an effective treatment in animal models of sepsis and is under investigation for human use. Reduced liver blood flow during septic shock may substantially alter the pharmacokinetics of rTFPI because clearance of rTFPI approaches liver blood flow. The aim of this study was to examine the effect of exercise-induced reduction in liver blood flow on the pharmacokinetics and pharmacodynamics of rTFPI.

METHODS

This was a two-way, open-label, randomized crossover study in eight healthy male volunteers. The subjects in both treatment groups received a continuous intravenous infusion of rTFPI (0.2 mg/kg/h) concurrently with intravenous sorbitol (50 mg/min) for 4 hours. Sorbitol was used as a biomarker for liver blood flow. The subjects were randomized to remain supine or to exercise on a bicycle ergometer for 30 minutes starting at the beginning of the third hour of the infusion.

RESULTS

Exercise reduced liver blood flow (mean +/- SEM) from 1.44 +/- 0.06 L/min to 0.40 +/- 0.03 L/min. The average clearance of rTFPI decreased from 0.73 +/- 0.04 L/min in the supine position to 0.25 +/- 0.02 L/min during exercise. This decrease in rTFPI clearance resulted in an 80% (95% confidence interval [CI], 60% to 102%) increase in plasma rTFPI levels during exercise. The average maximal prothrombin time and activated partial thromboplastin time values during exercise were 1.4 (95% CI, 0.4 to 2.5) and 4.4 (95% CI, 2.7 to 6.1) seconds higher compared with the supine steady-state level.

CONCLUSIONS

Reduction in liver blood flow by exercise markedly increased rTFPI concentrations and induced a slight but variable prothrombin time and activated partial thromboplastin time increase at the rTFPI dose studied.

Isolation modifies the behavioural response in rats

Twenty-four male wister rats were reared from weaning either alone (isolation reared) or in groups of five (socially reared) for 6 weeks. Thereafter, the present study examined and compared the behaviour of isolation and socially reared rats in the test of social interaction, in the elevated plus-maze test of anxiety, in the open field behavior of exploration and locomotion activity, and the depressive behaviour in forced swim test. Under high light in unfamiliar conditions isolation reared rats spent significantly more time in aggressive interactions (P < 0.05) and high levels of aggressive behaviour compared to the socially reared rats (P < 0.05). Isolation reared rats had spent less time in the open arms than the socially reared rats in the maze test (P < 0.05). Isolation reared rats were more exploratory than the socially reared rats in the open field test and the defaecation scores were less compared to the socially reared controls (P < 0.05). Isolated rats spent less time immobile on the rats' forced swim test behaviour but the difference was not statistically significant. These findings suggest that isolation reared rats are nervous, aggressive and hyperactive animals in a novel field. It appears that isolation rearing in the early stages of life has modified a variety of behaviour in the adult rats, and the investigation of the pattern of behavioural changes in isolation reared rats may help to explore the environmental influences on the development of human psychopathology.

Molecular epidemiology of an outbreak due to IRT-2 beta-lactamase-producing strains of Klebsiella pneumoniae in a geriatric department

In February 1998, 195 patients in the geriatric department of a French hospital were screened for the presence of co-amoxiclav-resistant Klebsiella pneumoniae. Eleven co-amoxiclav-resistant isolates obtained all produced an identical IRT-2 beta-lactamase. These K. pneumoniae isolates were clonally related and harboured a c. 55 kb non-conjugative plasmid encoding a non-class-1 integron-located blaIRT-2 gene. This study underlines that geriatric departments may be a reservoir for antibiotic-resistant strains and that IRT beta-lactamase-producing strains may be nosocomial pathogens.

Metabolism and excretion of [(14)C]celecoxib in healthy male volunteers

We determined the disposition of a single 300-mg dose of [(14)C]celecoxib in eight healthy male subjects. The [(14)C]celecoxib was administered as a fine suspension reconstituted in 80 ml of an apple juice/Tween 80/ethanol mixture. Blood and saliva samples were collected at selected time intervals after dosing. All urine and feces were collected on the 10 consecutive days after dose administration. Radioactivity in each sample was determined by liquid scintillation counting or complete oxidation and liquid scintillation counting. Metabolic profiles in plasma, urine, and feces were obtained by HPLC, and metabolites were identified by mass spectrometry and NMR. [(14)C]Celecoxib was well absorbed, reaching peak plasma concentrations within 2 h of dosing. [(14)C]Celecoxib was extensively metabolized, with only 2.56% of the radioactive dose excreted as celecoxib in either urine or feces. The total percentage of administered radioactive dose recovered was 84.8 +/- 4.9%, with 27.1 +/- 2.2% in the urine and 57.6 +/- 7.3% in the feces. The oxidative metabolism of celecoxib involved hydroxylation of celecoxib at the methyl moiety followed by further oxidation of the hydroxyl group to form a carboxylic acid metabolite. The carboxylic acid metabolite of celecoxib was conjugated with glucuronide to form the 1-O-glucuronide. The percentages of the dose excreted in the feces as celecoxib and the carboxylic acid metabolite were 2.56 +/- 1.09 and 54.4 +/- 6.8%, respectively. The majority of the dose excreted in the urine was the carboxylic acid metabolite (18.8 +/- 2.1%); only a small amount was excreted as the acyl glucuronide (1.48 +/- 0.15%).

[Colonization by methicillin-resistant Staphylococcus aureus is a predictive factor for the resistance phenotype of an infectious strain of S. aureus]

OBJECTIVE

To assess the predictive value of a previous colonization with methicillin-resistant Staphylococcus aureus for the resistance pattern of a bacteriological specimen significantly positive to S. aureus.

STUDY DESIGN

Retrospective study of patients' files.

PATIENTS

Patients admitted for at least 48 hours in a surgical intensive care unit from April 1, 1996 to December 31, 1997.

METHODS

Collection of patients' characteristics and chronology of positive microbiological specimens with methicillin-susceptible (MSSA) or -resistant (MRSA) S. aureus from medical and laboratory records. During the study period, screening for nasal or perineal colonization with MRSA was systematically performed on admission and weekly thereafter.

RESULTS

The files of 540 patients were reviewed. MSSA and MRSA infections occurred in 7% (39/540) and 4% (20/540) of the patients respectively. By opposition with MSSA infections, MRSA infections occurred more frequently in patients previously colonized with MRSA (13 infections in 63 colonized patients [21%] versus 7 infections in 477 non-colonized patients [2%], odds ratio = 18, confidence interval: 6-51, P < 0.0001). The median delay between colonization and infection was 5 days. The positive and negative predictive values for previous colonization with MRSA to predict infection with MRSA in presence of a bacteriological specimen significantly positive with S. aureus were 81 and 84%, respectively.

CONCLUSION

The probabilistic use of a glycopeptide in presence of a bacteriological specimen significantly positive with S. aureus should be limited to patients already colonized with MRSA, in order to decrease the abusive administration of these antibiotics.

Biochemical sequence analyses of GES-1, a novel class A extended-spectrum beta-lactamase, and the class 1 integron In52 from Klebsiella pneumoniae

Klebsiella pneumoniae ORI-1 was isolated in 1998 in France from a rectal swab of a 1-month-old girl who was previously hospitalized in Cayenne Hospital, Cayenne, French Guiana. This strain harbored a ca. 140-kb nontransferable plasmid, pTK1, that conferred an extended-spectrum cephalosporin resistance profile antagonized by the addition of clavulanic acid, tazobactam, or imipenem. The gene for GES-1 (Guiana extended-spectrum beta-lactamase) was cloned, and its protein was expressed in Escherichia coli DH10B, where this pI-5. 8 beta-lactamase of a ca. 31-kDa molecular mass conferred resistance to oxyimino cephalosporins (mostly to ceftazidime). GES-1 is weakly related to the other plasmid-located Ambler class A extended-spectrum beta-lactamases (ESBLs). The highest percentage of amino acid identity was obtained with the carbenicillinase GN79 from Proteus mirabilis; with YENT, a chromosome-borne penicillinase from Yersinia enterocolitica; and with L-2, a chromosome-borne class A cephalosporinase from Stenotrophomonas maltophilia (36% amino acid identity each). However, a dendrogram analysis showed that GES-1 clustered within a class A ESBL subgroup together with ESBLs VEB-1 and PER-1. Sequencing of a 7,098-bp DNA fragment from plasmid pTK1 revealed that the GES-1 gene was located on a novel class 1 integron named In52 that was characterized by (i) a 5' conserved segment containing an intI1 gene possessing two putative promoters, P(1) and P(2), for coordinated expression of the downstream antibiotic resistance genes and an attI1 recombination site; (ii) five antibiotic gene cassettes, bla(GES-1), aac(6')Ib' (gentamicin resistance and amikacin susceptibility), dfrXVb (trimethoprim resistance), a novel chloramphenicol resistance gene (cmlA4), and aadA2 (streptomycin-spectinomycin resistance); and (iii) a 3' conserved segment consisting of qacEDelta1 and sulI. The bla(GES-1) and aadA2 gene cassettes were peculiar, since they lacked a typical 59-base element. This work identified the second class A ESBL gene of a non-TEM, non-SHV series which was located in the plasmid and integron, thus providing it additional means for its spread and its expression.

Lipotoxic heart disease in obese rats: implications for human obesity

To determine the mechanism of the cardiac dilatation and reduced contractility of obese Zucker Diabetic Fatty rats, myocardial triacylglycerol (TG) was assayed chemically and morphologically. TG was high because of underexpression of fatty acid oxidative enzymes and their transcription factor, peroxisome proliferator-activated receptor-alpha. Levels of ceramide, a mediator of apoptosis, were 2-3 times those of controls and inducible nitric oxide synthase levels were 4 times greater than normal. Myocardial DNA laddering, an index of apoptosis, reached 20 times the normal level. Troglitazone therapy lowered myocardial TG and ceramide and completely prevented DNA laddering and loss of cardiac function. In this paper, we conclude that cardiac dysfunction in obesity is caused by lipoapoptosis and is prevented by reducing cardiac lipids.

Tissue factor pathway inhibitor dose-dependently inhibits coagulation activation without influencing the fibrinolytic and cytokine response during human endotoxemia

Inhibition of the tissue factor pathway has been shown to attenuate the activation of coagulation and to prevent death in a gram-negative bacteremia primate model of sepsis. It has been suggested that tissue factor influences inflammatory cascades other than the coagulation system. The authors sought to determine the effects of 2 different doses of recombinant tissue factor pathway inhibitor (TFPI) on endotoxin-induced coagulant, fibrinolytic, and cytokine responses in healthy humans. Two groups, each consisting of 8 healthy men, were studied in a double-blind, randomized, placebo-controlled crossover study. Subjects were studied on 2 different occasions. They received a bolus intravenous injection of 4 ng/kg endotoxin, which was followed by a 6-hour continuous infusion of TFPI or placebo. Eight subjects received 0.05 mg/kg per hour TFPI after a bolus of 0.0125 mg/kg (low-dose group), and 8 subjects received 0.2 mg/kg per hour after a bolus of 0.05 mg/kg (high-dose group). Endotoxin injection induced the activation of coagulation, the activation and subsequent inhibition of fibrinolysis, and the release of proinflammatory and antiinflammatory cytokines. TFPI infusion induced a dose-dependent attenuation of thrombin generation, as measured by plasma F1 + 2 and thrombin-antithrombin complexes, with a complete blockade of coagulation activation after high-dose TFPI. Endotoxin-induced changes in the fibrinolytic system and cytokine levels were not altered by either low-dose or high-dose TFPI. The authors concluded that TFPI effectively and dose-dependently attenuates the endotoxin-induced coagulation activation in humans without influencing the fibrinolytic and cytokine response. (Blood. 2000;95:1124-1129)

Effects of celecoxib, a novel cyclooxygenase-2 inhibitor, on platelet function in healthy adults: a randomized, controlled trial

Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) nonspecifically inhibit cyclooxygenase-1 (COX-1), an enzyme critical to normal platelet function, and COX-2, which mediates inflammatory response mechanisms. Celecoxib, an antiarthritic agent that inhibits COX-2 but spares COX-1 at therapeutic doses, is expected to have minimal effects on platelet function. A double-blind, randomized, placebo-controlled study of 10 days' duration was conducted in 24 healthy adults to compare the effects on platelet function of a supratherapeutic dose of celecoxib (600 mg bid) with a standard dose of naproxen (500 mg bid), a conventional NSAID. Ex vivo platelet aggregation in response to standard agonists (collagen, arachidonate, or U46619 [a thromboxane A2 receptor agonist]), bleeding time, and serum thromboxane B2 (TxB2) level were measured. Unlike celecoxib or placebo, naproxen produced statistically significant reductions in platelet aggregation and serum TxB2 levels and increased bleeding time. The results indicate that even at supratherapeutic doses, celecoxib will not interfere with normal mechanisms of platelet aggregation and hemostasis, supporting the premise that celecoxib is COX-1 sparing relative to conventional NSAIDs.

Unsafe injections and the transmission of hepatitis B and C in a periurban community in Pakistan

Following reports of frequent deaths associated with jaundice and chronic liver disease among adults in a periurban community of Karachi, Pakistan, an investigation was conducted to evaluate the relationship between injections and viral hepatitis infections, to identify the reasons why patients received frequent injections, and to observe the injection practices employed in clinics. Two hundred and three adult patients were interviewed as they left each of the 18 area clinics. Practitioners were interviewed and three consecutive injections were observed at each clinic. Eighty-one per cent of patients received an injection on the day of the interview. Of the 135 patients who provided a serum sample, 59 (44%) had antibodies against hepatitis C virus and 26 (19%) had antibodies against hepatitis B virus. Patients who received more injections were more likely to be infected with hepatitis C. If oral and injected medications were equally effective, 44% of patients preferred injected medication. None of the practitioners knew that hepatitis C could be transmitted by injections. Non-sterile syringes and needles that had been used earlier in the day on other patients were used for 94% of the observed injections. Interventions to limit injections to those which are safe and clinically indicated are needed to prevent injection-associated infections in Pakistan and other low-income countries.

Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. A randomized, controlled trial

BACKGROUND

Chlorhexidine is better than povidone-iodine for care of catheter sites, but it is not known whether chlorhexidine is superior in reducing blood culture contamination.

OBJECTIVE

To determine whether alcoholic chlorhexidine is a more effective skin antiseptic for collection of blood cultures than aqueous povidone-iodine.

DESIGN

Randomized, controlled trial.

SETTING

Three adult intensive care units in a French university hospital.

PATIENTS

403 adults who had at least one blood culture drawn through a peripheral vein.

INTERVENTIONS

Patients were randomly assigned to receive skin preparation with an aqueous solution of 10% povidone-iodine or an alcoholic solution of 0.5% chlorhexidine before phlebotomy.

MEASUREMENTS

Contamination rates of blood cultures.

RESULTS

Of 2041 blood cultures collected in 403 patients, 124 yielded pathogens. Chlorhexidine reduced the incidence of blood culture contamination more than povidone-iodine (14 of 1019 cultures [1.4%] compared with 34 of 1022 cultures [3.3%]; odds ratio, 0.40 [95% CI, 0.21 to 0.75]; P = 0.004).

CONCLUSION

Skin preparation with alcoholic chlorhexidine is more efficacious than skin preparation with aqueous povidone-iodine in reducing contamination of blood cultures.

Celecoxib, a specific COX-2 inhibitor, has no significant effect on methotrexate pharmacokinetics in patients with rheumatoid arthritis

OBJECTIVE

To determine the effects of celecoxib, a specific inhibitor of cyclooxygenase 2 (COX-2) on the renal clearance and plasma pharmacokinetic profile of stable methotrexate (MTX) doses in patients with rheumatoid arthritis (RA).

METHODS

Fourteen adult female patients with RA taking a stable weekly dose of MTX (5 to 15 mg/wk) for a minimum of 3 months were randomized to receive concomitantly either celecoxib (200 mg BID) or placebo for a period of 7 days in a single blind, 2 period crossover study of MTX pharmacokinetics and renal clearance.

RESULTS

The plasma pharmacokinetic profile of MTX did not change significantly when celecoxib or a placebo was coadministered. The mean renal clearance of MTX alone, 7.98+/-2.18 l/h, was virtually unchanged by coadministration of celecoxib (7.94+/-1.61 l/h) or placebo (7.97+/-1.19 l/h).

CONCLUSION

Celecoxib has no significant effect on the pharmacokinetics or renal clearance of MTX in patients with RA, although these results should be confirmed in prospective studies of elderly and renally impaired patients.

Cardiac drug and psychotropic drug interactions: significance and recommendations

Understanding cardiac drug interactions with concurrent psychotropic prescriptions is essential for the practicing cardiologist and primary care physician, as well as for the psychiatrist. There has been an explosive use of new drugs in both psychiatry and cardiology without widespread knowledge of their potential interactions. The increasing tendency toward poly-pharmacy, the use of psychotropic medications by cardiologists and primary care physicians caring for cardiac patients, and the growth of the aging population present major challenges for the practitioner. Finally, there is a need to have models/paradigms for predicting potential drug interactions--e.g., the Cytochrome p450 schema. This paper describes a method to identify, understand, and codify the interactions between psychotropic and cardiac drugs, a systematic approach for updating this key database and specific cardiac-psychotropic drug interactions. Specifically, this paper 1) details the interactions, 2) addresses the level of their clinical significance, 3) describes the potential mechanism(s) of the interactions, and 4) offers recommendations to the clinician. Since the majority of the original clinical trials, either for cardiac medications or psychotropic drugs, do not include studies comparing these two drug domains contemporaneously, their interactions often become known only with their combined use in the clinical arena, using the patient as "guinea pig," and through subsequent reporting.

Plasma protein binding of celecoxib in mice, rat, rabbit, dog and human

The plasma protein binding of celecoxib was determined for animals and humans using in vitro and ex vivo methods. Eight, healthy, human volunteers (three male, five female, 20-39 years) received celecoxib (600 mg) BID for 7 days, blood samples were collected and concentrations of bound and unbound celecoxib determined. The fraction of bound drug in the volunteers was constant (97.4 +/- 0.1%) at total celecoxib plasma concentrations ranging from 0.01 to 4.02 microg/mL. The ex vivo plasma protein binding of celecoxib in the animals was concentration-independent up to approximately 12, 8 and 10 microg/mL for mouse, rat and dog, respectively. The plasma protein binding of celecoxib after a single oral dose of 10 and 300 mg/kg to mice was 98.3 +/- 0.2%, of 1 and 400 mg/kg to rats was 98.3 +/- 0.2% and of 1 and 100 mg/kg to dogs was 98.5 +/- 0.1%. The percent binding of celecoxib to plasma proteins in vitro was slightly lower than those values determined ex vivo. The in vitro binding of celecoxib to plasma protein was constant over the concentrations of 0.1-10 microg/mL for all species, except rat.

Molecular characterization of In50, a class 1 integron encoding the gene for the extended-spectrum beta-lactamase VEB-1 in Pseudomonas aeruginosa

A clinical isolate of Pseudomonas aeruginosa, JES, was resistant to extended-spectrum cephalosporins with a marked synergistic effect with clavulanic acid on a routine antibiogram. Preliminary PCR analysis revealed the presence of blaVEB-1, an integron-located gene encoding an extended-spectrum beta-lactamase previously identified in Escherichia coli MG-1. Using class 1 integron primers and blaVEB-1 intragenic primers, the insert region of the blaVEB-1 containing integron along with some flanking sequence from P. aeruginosa JES was amplified and subsequently sequenced. In50 contains within its variable region, in addition to qacE delta 1 and sull genes commonly found in class 1 integrons, two gene cassettes, veb1 and aadB. In50 is peculiar since its attI1 site is interrupted by two novel insertion sequences, IS1999 and IS2000. P. aeruginosa JES and Escherichia coli MG-1 strains were isolated from patients previously hospitalized in south east Asian countries. The finding of blaVEB-1 in these strains and on different integrons underlines the interspecies spread of this integron-located extended-spectrum beta-lactamase gene.

Pseudoglandular formations in clot sections from fine needle aspirates--an artefact caused by bubble formation during aspiration

AIMS

To report the occurrence of an uncommon artefact producing pseudoglandular formations in clot sections from haemorrhagic fine needle aspirations.

METHODS

All available histological material from 610 fine needle aspirations by pathologists (23 g needle) over a five year period was reviewed. The frequency and associations of the pseudoglandular artefact was assessed.

RESULTS

Clot sections were prepared in 41 of the 610 cases (7%). Bubbles were present in the clots in 22 of these cases (54%), and in three cases (7%) these were lined by lymphocytes creating pseudoglandular formations. These were two lymph node aspirates and one thyroid aspirate. In four further cases lesser numbers of cells partly lined some of the bubbles; these were lymphocytes, macrophages, or in one case, thyroid epithelial cells.

CONCLUSIONS

When clot sections are prepared in cases of haemorrhagic fine needle aspiration, bubbles are often produced during suction; these can on occasion become lined by lymphocytes or other cells, leading to pseudoglandular formations. Recognition of this artefact will prevent unnecessary further investigation of their nature.

Drug, meal and formulation interactions influencing drug absorption after oral administration. Clinical implications

Drug-drug, drug-formulation and drug-meal interactions are of clinical concern for orally administered drugs that possess a narrow therapeutic index. This review presents the current status of information regarding interactions which may influence the gastrointestinal (GI) absorption of orally administered drugs. Absorption interactions have been classified on the basis of rate-limiting processes. These processes are put in the context of drug and formulation physicochemical properties and oral input influences on variable GI physiology. Interaction categorisation makes use of a biopharmaceutical classification system based on drug aqueous solubility and membrane permeability and their contributions towards absorption variability. Overlaying this classification it is important to be aware of the effect that the magnitudes of drug dosage and volume of fluid administration can have on interactions involving a solubility rate limits. GI regional differences in membrane permeability are fundamental to the rational development of extended release dosage forms as well as to predicting interaction effects on absorption from immediate release dosage forms. The effect of meals on the regional-dependent intestinal elimination of drugs and their involvement in drug absorption interactions is also discussed. Although the clinical significance of such interactions is certainly dependent on the narrowness of the drug therapeutic index, clinical aspects of absorption delays and therapeutic failures resulting from various interactions are also important.

Effect of exposure to balanced salt solution upon the hardness of the crystalline lens

BACKGROUND

The nucleus confers most of the hardness upon the lens, water content decreases towards the centre of the nucleus and a relative dehydration accompanies increased hardness in some cataractous lenses. It is a possibility that exposure and incubation of the inner layers of the nucleus to balanced salt solution (BSS) can result in the softening of the nucleus.

PURPOSE

This study aimed to investigate the effect of BSS upon the lens hardness.

METHODS

Nuclear colour element of cataract was graded biomicroscopically. Following extracapsular cataract surgery the lens nucleocortex was divided into two equal parts and each half was allocated randomly to incubation in BSS or air for 5 min before the hardness of each section was assessed by an automated guillotine.

RESULTS

Following incubation with BSS the mean force necessary to bisect the lens was 0.50 N and in the control air group the mean force was 0.64 N. The lenses in the BSS-treated group were consistently softer than those in the control group, with a mean softening of 18.3% (P=0.001). The amount of softening was not related to the nuclear colour (P=0.6) or age (P=0.1).

CONCLUSION

Softening of the lens through physical disruption has previously been reported. This study describes the phenomenon of nuclear softening following exposure to BSS, indicating that lens softening can occur through biochemical means.

The analysis of aqueous humor constituents using capillary zone electrophoresis

One of the difficulties encountered in the study of aqueous humor is the relatively small volume generally available for analysis. The purpose of this study was to investigate the potential use of capillary zone electrophoresis (CE) for the analysis of nanolitre quantities of this fluid. Twelve samples of aqueous humor were obtained from patients undergoing cataract surgery and a further three samples were from non cataract post mortem subjects within 6 hr of death. CE was carried out in an uncoated fused silica glass capillary, 75 mu internal diameter and 100 cm long using a run buffer of 40 mM borate pH 9.4 containing 0.4 g l-1 methylcellulose. Detection of the separated zones was by ultra violet absorption at 200 nm. Preliminary identification of peaks was achieved by enzymatic hydrolysis and spiking with purified analytes. A number of very well resolved peaks were obtained from both cataract and post mortem samples using nanolitre quantities of unmodified fluid. Additional peaks were noted in the post mortem samples, most of which were likely to be due to a partial breakdown of the blood aqueous humor barrier. The profiles obtained were not significantly affected by various drugs routinely administered during cataract surgery. This preliminary study has demonstrated the potential value of CE in the analysis of aqueous humor in health and disease.

[Werner syndrome. Apropos of a case]

A 26 year-old woman, whose parents were consanguineously married, was admitted to our center because of bilateral juvenile cataract. The patient exhibited short stature, sclerodermalike appearance of the skin with a typical bird-like facies, thinning and graying of hair, high pitched voice and hypogonadism. Werner's syndrome, was diagnosed. History, pathogeny, clinical features, diagnosis and cataract surgery are discussed.

Chemical modifications of the vasoconstrictor peptide angiotensin II by nitrogen oxides (NO, HNO2, HOONO)--evaluation by mass spectrometry

Nitric oxide (NO) and angiotensin II are natural regulators of blood pressure. Under aerobic conditions, NO is transformed into its higher oxides (N2O4, NO2, NO/NO2 or N2O3) and oxoperoxonitrate (currently named peroxynitrite) by coupling with superoxide. Previous studies have shown that these reactive nitrogen species should be involved in vivo in the transformation of cysteine and tyrosine into the corresponding nitrosothiol and 3-nitrotyrosine. In the present study, attention has been focused on the relative reactivities of HNO2, peroxynitrite, and NO in the presence of dioxygen, towards the arginine and tyrosine residues of the peptide angiotensin II. Nitration of the tyrosine residue is clearly the main reaction with peroxynitrite. By contrast, besides 20% of nitration of the tyrosine residue, NO in the presence of dioxygen leads to nitrosation reactions with the arginine residue similar to those observed with HNO2 at pH 5, possibly through the intermediate N2O3 reactive species. Angiotensin II is converted for the most part to peptides having lost either a terminal amine function or the whole guanido group, leading respectively to citrulline-containing angiotensin II or to a diene derivative. Identification established mainly by tandem mass spectrometry of peptidic by-products allows us to propose a cascade of nitrosations of all the amine functions of the arginine residue. Further in vivo studies show that transformations of the arginine residue in angiotensin II do not alter its vasoconstrictive properties, whereas nitration of the tyrosine residue totally inhibits them.

Mechanism of compound- and species-specific food effects of structurally related antiarrhythmic drugs, disopyramide and bidisomide

PURPOSE

To determine mechanism of food effects observed with bidisomide but not with the structurally similar drug, disopyramide.

METHODS

Food effect studies of bidisomide and disopyramide were conducted with and without a standardized high fat meal in healthy subjects and in the dog. Intestinal metabolism of disopyramide and absorption of the metabolites were examined after oral administration of the drug to the dogs with portal vein canula implanted. Effects of food or a mixture of amino acids on metabolism of [14C]disopyramide were examined after intraportal infusion of the drug with and without high fat meal and after drug infusion into portal vein with the amino acid mixture, respectively.

RESULTS

The systemic availability of bidisomide was markedly reduced with food in humans, whereas the systemic availability of disopyramide did not change notably. In the dog, the systemic availability of bidisomide was also reduced with food. The systemic availability of disopyramide did not change with food. This was due to the fact that reduction in absorption was compensated by reduction of metabolism. There was no evidence for reduction in hepatic and intestinal metabolism with food.

CONCLUSIONS

The apparent reduction in disopyramide metabolism with food may be due to an increase in colonal and/or lymphatic absorption. Food effects on the apparent systemic availability of bidisomide and disopyramide in the dog were similar to those in the rat. However, there was substantial species difference in the mechanism of food effects.

Reduced systemic availability of an antiarrhythmic drug, bidisomide, with meal co-administration: relationship with region-dependent intestinal absorption

PURPOSE

The aim of this research was to determine the mechanism by which a co-administered meal decreases the oral absorption of bidisomide and does not influence the oral absorption of the chemically-related antiarrhythmic agent, disopyramide.

METHODS

Bidisomide plasma levels, following oral administration and intravenous infusion in the fasted state and with various meal treatments, were determined in human subjects. A dialysis technique was employed to examine the potential for drug binding to meal homogenates. Plasma levels, following drug administration through duodenal and jejunal intestinal access ports and following various meal treatments with oral drug co-administration, were compared for bidisomide and disopyramide in a canine model.

RESULTS

Bidisomide plasma AUC was significantly reduced following oral drug co-administration with breakfast compared to fasted-state controls in human subjects and in dogs independent of the composition of the solid cooked breakfast. While intravenous bidisomide infusion in human subjects showed a statistically significant reduction in AUC 15 minutes after oral administration of a high fat breakfast as compared to drug infusion in the fasted state, the reduction (-13%) was substantially smaller than the reduction (from -43% to -63%) observed with oral bidisomide meal co-administration. The percentages of bidisomide and disopyramide lost by binding to homogenates of cooked breakfast were 25.0 +/- 5.7% and 23.7 +/- 7.7%, respectively, as determined by dialysis at 4 hours. In dogs, the extent of absorption of disopyramide was comparable from oral, duodenal and mid-jejunal administration while the extent of bidisomide absorption from mid-jejunal administration was significantly lower than for oral or duodenal administration. Non-viscous liquid meals decreased Cmax but not AUC, while viscous homogenized solid meals decreased both Cmax and AUC for bidisomide with oral drug-meal co-administration. Oral non-caloric hydroxypropyl methylcellulose meals decreased bidisomide to the same extent as homogenized solid meals but did not lower disopyramide AUC.

CONCLUSIONS

The significant reduction in bidisomide plasma levels observed with meal co-administration in human subjects was predominantly mediated through a reduction in drug absorption and was independent of solid meal composition. The difference in meal effect on the absorption of the two drugs in humans did not appear to be a function of drug binding to cooked meal components over typical human upper gastrointestinal residence times. In dogs, the high-viscosity medium generated by oral co-administration of a solid meal reduced the upper intestinal absorption of bidisomide and disopyramide. Bidisomide AUC was decreased since it was well absorbed in the upper but not lower small intestine. Disopyramide AUC was not significantly affected since it was well absorbed from both regions. A similar mechanism may play a role in drug plasma level reductions following oral co-administration with solid meals for drugs showing similar regionally-dependent absorption profiles.

[Therapeutic and prognostic problems of traumatic cataracts. Apropos of 45 cases]

PURPOSE

The purpose of this study was to investigate clinical profile, prognosis and therapeutics problems of traumatic cataract.

MATERIAL AND METHODS

A retrospective study was conducted in 45 cases of traumatic cataracts (1993-1996). Mean age was 19 years, principally male. We chose the extracapsular extraction with implantation in 28 cases.

RESULTS

Overall results were satisfactory (62% with VA > 2/10); they are better in patients with implantation and poorer in infants. Postoperatively, most complications were major inflammatory and secondary capsular opacification essentially children. The importance of systemic corticotherapy and prevention of amblyopia in children is emphasized.

Phase I/II study of the toxicity, pharmacokinetics, and activity of the HIV protease inhibitor SC-52151

SC-52151, an HIV-1 protease inhibitor, was developed as an ethanol-based elixir and subsequently as a self-emulsifying drug delivery system (SEDDS) to improve bioavailability. To evaluate formulation and treatment regimen effects, we conducted a four-arm, phase I/II study using the highest previously tested daily dose, 2250 mg. Forty-nine patients received the elixir or SEDDS at a dosage of 750 mg three times daily or 1125 mg twice daily for 14 days. One patient developed hypertriglyceridemia, and one had fever and dyspnea. The SEDDS formulation compared with the elixir resulted in a larger area under the concentration-time curve (AUC, p < 0.001), peak (Cmax, p = 0.041) and trough (Cmin, p = 0.025). Twice-daily administration compared with administration three times daily produced a higher cumulative AUC (p = 0.008). Both SEDDS regimens produced mean plasma concentrations above the 90% inhibitory concentration (IC90) for HIV. A mean decline of 0.03 log10 RNA copies (SEDDS) and an increase of 0.15 log10 (elixir) were observed. Although SC-52151 was well tolerated and the SEDDS formulation resulted in plasma concentrations above the IC90 for viral replication, no antiviral activity was produced.

SC-52458, an orally active angiotensin II-receptor antagonist: inhibition of blood pressure response to angiotensin II challenges and pharmacokinetics in normal volunteers

This study was designed to assess in normal volunteers the potency, efficacy, and tolerability of the new nonpeptidic, orally active, angiotensin (Ang) II subtype 1 (AT1)-receptor antagonist SC-52458. After a randomized, single-blind, placebo-controlled protocol, two groups of eight healthy men ingested placebo or increasing single oral doses (10, 25, and 50 mg or 100, 150, and 200 mg) of SC-52458. Finger blood pressure (BP) was continuously monitored (Finapres), and BP response to repeated intravenous challenges with Ang II was compared with baseline BP response to the same dose of Ang II. Up to 24 h after drug intake, effects on plasma renin activity (PRA), Ang II, and aldosterone and pharmacokinetics were estimated. One, 4, and 10 h after the 200-mg dose, diastolic BP response to Ang II challenges was decreased from 30.3 to 2.6 mm Hg (mean +/- SEM; n = 8; i.e., to 8.3 +/- 1.1% of baseline response), 10.1 mm Hg (35.4 +/- 1.8%), and 17.5 mm Hg (58.7 +/- 1.8%), respectively. SC-52458 produced dose-related increases in PRA and Ang II concentrations < or = 10 h after drug intake. Plasma aldosterone concentrations tended to be decreased for < or = 24 h after SC-52458 doses of > or = 100 mg. No drug-related side effects were observed. The pharmacokinetics were linear over the dose range of 10-150 mg (t1/2 = 1.14-2.39 h). Efficacy was dose dependent, with a peak effect after 1 h. In conclusion, the novel AT1-receptor antagonist SC-52458 is well tolerated and orally active. It produces a rapid-onset inhibition of the renin-angiotensin system and reduces BP response to Ang II for > or = 10 h. These characteristics promise strong antihypertensive properties for SC-52458.

Oxaprozin and piroxicam, nonsteroidal antiinflammatory drugs with long half-lives: effect of protein-binding differences on steady-state pharmacokinetics

The nonsteroidal antiinflammatory drugs (NSAIDs) oxaprozin and piroxicam have long elimination half-lives (t 1/2 approximately 55 hours), permitting once-daily dose regimens. The protein-binding characteristics of these drugs, however, vary widely. This study examines the effect of these binding differences on the drugs' disposition kinetics at steady state. A total of 52 participants (26 young healthy volunteers, and 26 elderly osteoarthritic patients, 15 men and 37 women (2 of them poor metabolizers of debrisoquine [CYP2D6]) completed the two-period, two-treatment, randomized, single-dose and 21-day, once-daily multiple-dose, cross-over study. Doses of oxaprozin and piroxicam were 1,200 mg once daily and 20 mg once daily, respectively. Mean single-dose kinetic parameters of oxaprozin versus piroxicam did not differ more than +/-14% (t1/2, 53.0 versus 57.4 hours; apparent oral clearance adjusted for 70-kg body weight [Clpo], 0.139 versus 0.121 L/hr; apparent volume of distribution adjusted for 70-kg body weight [Vd/F]; 10.2 L versus 9.13 L). Protein binding was plasma-concentration dependent with oxaprozin (range, 10-400 mg/L) but not with piroxicam (range, 1-30 mg/ L). Steady-state conditions were established within 3 days with oxaprozin but took almost 12 days with piroxicam. Compared with the single-dose values, steady-state Clpo (Clpo,ss) and Vd/F of total drug increased with oxaprozin by almost 127% but remained within +/-10% with piroxicam. Post-steady-state apparent t 1/2 of the total and unbound drugs of approximately 62 hours were similarly prolonged with piroxicam but differed substantially with oxaprozin (50.6 hours [total drug] versus 23.8 hours [unbound drug]). Single dose Clpo (Clpo,sd) values of both NSAIDs were significantly correlated in the study populations. With both NSAIDs, Clpo in the two poor metabolizers of debrisoquine was within +/-20% of mean values for the population. Clinically important age- and gender-dependent decreases were not observed in the weight-adjusted, Clpo,sd or Vd/F values of the total drug for either NSAID. Clearances of the two NSAIDs were significantly correlated, suggesting that a common P450 isozyme (most likely CYP2C9, in that piroxicam is a known substrate of this isozyme) may be at least partly involved in the oxidative metabolism of these NSAIDs.