bluuebunny/crossref_metadata_2025 huggingface dataset:
OBSERVATIONS ON THE SITES OF REMOVAL OF BACTERIA FROM THE BLOOD IN PATIENTS WITH BACTERIAL ENDOCARDITIS
Authors: Beeson Paul B. , Brannon Emmett S. , Warren James V.
Published: June 2004

In 6 patients with bacterial endocarditis studies were made of the bacterial content of arterial and venous blood. Paired samples were collected, approximately simultaneously, from two different locations in the circulatory system, and colony counts were determined. As many as 48 specimens were taken for culture during a single period of study. Venous blood was drawn not only from different locations in the extremities, but also from the superior and inferior venae cavae, the right auricle, and the hepatic and renal veins.

As would be expected, colony counts were highest in arterial blood.

Blood from the antecubital veins gave colony counts only slightly lower than arterial blood. In the femoral veins, on the other hand, there were appreciably fewer organisms. This difference is attributed to the type of tissues drained by the two veins.

Colony counts in blood from the superior and inferior venae cavae were also lower than arterial counts, the ratio being comparable to that found in femoral vein blood.

In the renal veins colony counts were only slightly below the arterial level indicating that few organisms are removed from the blood during passage through the kidneys.

The greatest reduction in bacterial content was found in hepatic vein blood. In 3 of the 6 subjects this reduction amounted to more than 95 per cent, and in all subjects the difference was very considerable.

Mixed venous blood in the right auricle of the heart gave colony counts which were usually one-half to two-thirds as high as in corresponding samples of arterial blood.

An interesting finding in these studies was a remarkable constancy of the bacterial content of arterial blood, during periods of 1 or 2 hours. Despite the fact that a considerable portion of the bacteria which leave the heart in arterial blood appear to be removed during a single circuit of the body, the number of bacteria in successive samples of arterial blood shows little change. This indicates that in bacterial endocarditis organisms are discharged into the blood from the endocardial vegetations at a comparatively even rate, rather than in a haphazard fashion as a result of the breaking off of infected particles.
ANAEROBIC GLYCOLYSIS OF THE BRAIN IN EXPERIMENTAL POLIOMYELITIS
Authors: Wood Harland G. , Rusoff Irving I. , Reiner John M.
Published: June 2004

The rate of anaerobic glycolysis of brain tissue was compared for normal animals and animals with experimentally induced poliomyelitis, using two different strains of mice and two different procedures. The report of interference of poliomyelitis with anaerobic glycolysis of brain was not confirmed. In one series there was a small increase and in the other series a small decrease in the brain QCOCO2N2 calculated for infected animals as compared to normal animals. When the calculations were made on the basis of wet weight of brain there was no difference in glycolysis.

It is considered that the methods so far used for study of the enzymes may be inadequate, and that no decision is as yet possible on the effect of poliomyelitis on anaerobic glycolysis.
A STUDY OF TISSUE CULTURE CELLS BY ELECTRON MICROSCOPY
Authors: Porter Keith R. , Claude Albert , Fullam Ernest F.
Published: June 2004

By means of a tissue culture technique, cells from chick embryos were procured in a state which proved to be suitable for electron microscopy. The electron micrographs disclosed details of cell structure not revealed by other methods of examination.
STUDIES IN RODENT POLIOMYELITIS
Authors: Jungeblut Claus W.
Published: June 2004

1. Attempts to separate by processes of physical segregation, i.e. ultrafiltration, ultracentrifugation, or dialysis, from live SK murine poliomyelitis virus a non-pathogenic agent capable of interfering with simian poliomyelitis virus were unsuccessful. Neither was it possible to convert live SK murine virus into a non-pathogenic interfering agent by processes of chemical inactivation, i.e., phenolization or formalinization.

2. Preparations of SK murine virus, which had been markedly attenuated by ultraviolet irradiation, gave evidence of having retained some interfering power in rhesus monkeys.

3. MM murine poliomyelitis virus interfered, both in mixture tests and by peripheral administration, with two simian strains of poliomyelitis virus. With adequate amounts, distinct protective effects could be obtained in rhesus monkeys which had received murine virus (animal passage or tissue culture virus) up to 48 hours after intracerebral infection with simian poliomyelitis virus.

4. Theiler's virus of spontaneous mouse encephalomyelitis, when tested in mixture with simian poliomyelitis virus, gave some evidence of irregular and low grade interference. Interference could not be shown conclusively in experiments to prevent poliomyelitic infection or to modify its effects.

5. The nature of the interfering agent present in murine virus is discussed.
THE CARDIOTOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES
Authors: Cantoni G. L. , Bernheimer Alan W.
Published: June 2004

1. The mechanism of sensitization of the isolated frog' heart to a product of the hemolytic streptococcus has been investigated. The sensitization depends upon the release from the isolated heart of a substance which inhibits the action of the cardiotoxin. The inhibitor is released upon the first (sensitizing) administration of cardiotoxin, but not upon the second (contracture-producing) administration.

2. The inhibitor released by the heart neutralizes the lethal factor present in the streptococcal preparation employed.

3. Some of the properties of the inhibitor have been investigated.
STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI
Authors: Perlman Ely , Binkley Francis , Goebel Walther F.
Published: June 2004

1. Volunteers have been immunized with the purified specific antigen of Type V Shigella paradysenteriae (Flexner). The subjects developed a high titer of bacterial agglutinins and mouse-protective antibodies. The agglutinin titer fell moderately after a period of 6 months. The subjects responded fairly well to a small recall dose of the antigen.

2. Two individuals from a group of 10 injected with the specific polysaccharide obtained from Type V organisms responded with an increase in bacterial agglutinins. Mouse-protective antibodies were demonstrable in the one serum tested.
A NEW VIRUS DISEASE OF PIGEONS
Authors: Smadel Joseph E. , Jackson E. B. , Harman John W.
Published: June 2004

A virus has been isolated from the tissues of a pigeon with visceral lesions that were characterized by focal necrosis of parenchymatous tissue, by the presence in affected cells of intranuclear inclusions of the herpetic type, and by secondary inflammatory reaction. This newly recognized virus, which has been tentatively called the I.N.I. agent is pathogenic for pigeons and embryonated eggs but is avirulent for rabbits, guinea pigs, and mice. The virus is smaller than the agent of psittacosis and is immunologically different from it.

The I.N.I. agent and psittacosis virus were both of etiological importance in an epizootic among pigeons. Some birds were infected simultaneously with the two agents while others were infected with only one.
REVERSIBLE INACTIVATION OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES
Authors: McCarty Maclyn
Published: June 2004

1. The transforming substance of Pneumococcus Type III is inactivated by treatment with ascorbic acid. This effect of ascorbic acid is catalyzed by traces of cupric ion and is prevented by the presence of sulfhydryl compounds.

2. Under certain conditions, the activity of transforming substance treated with ascorbic acid can be restored by the use of glutathione and other sulfhydryl compounds.

3. Other compounds, such as catechol, hydroquinone, and p-phenylenediamine, which undergo autoxidation similar to that of ascorbic acid, have an analogous effect on the transforming substance.

4. The effect of these compounds on the transforming substance is nullified by exclusion of oxygen or by the use of catalase.

5. It is concluded that inactivation of the transforming substance is probably oxidative in character and depends on the formation of peroxides in the course of autoxidation of ascorbic acid or related compounds.

6. The relation of this phenomenon to that of the inactivation of other biologically active substances by ascorbic acid is discussed.
LOSS OF GROUP CARBOHYDRATE DURING MOUSE PASSAGES OF A GROUP A HEMOLYTIC STREPTOCOCCUS
Authors: Wilson Armine T.
Published: June 2004

In the course of rapid passages through mice a strain of group A type 27 hemolytic streptococcus was found to have lost its group carbohydrate without the loss of type-specific precipitinogens, agglutinogens, or its capacity to induce protective antibodies in rabbits, and without the acquisition of the carbohydrate of another group.

The loss of group carbohydrate was shown to be complete, within the limits of the methods for its detection. Extracts of the anomalous strain did not react with group A antisera; and antisera prepared with organisms of this anomalous strain did not contain demonstrable antibodies for the group carbohydrate. Bacterial suspension of the anomalous strain failed to absorb any appreciable amount of group-specific antibody.

The fact that the anomalous strain lacking group-specific carbohydrate, C, was derived from the original was established by the demonstration of persistence of its other characteristics, in particular the precipitinogens, agglutinogens, and antigens responsible for protective antibodies of type 27.
STUDIES ON THE DENATURATION OF ANTIBODY
Authors: Wright George G.
Published: June 2004

The specific rate of inactivation of antitoxin in urea solutions, as measured by the Römer neutralization test with toxin, has been shown to be independent of the concentration of protein under the conditions studied. The amount of precipitate obtained in the quantitative precipitation test with toxin, however, increases greatly with increasing protein concentration during denaturation. The time during which the protein concentration is important in this respect has been shown to be the interval in which the urea is being dialyzed from the solutions. The meaning of the results is discussed.
EFFECT OF ENZYME INHIBITORS AND ACTIVATORS ON THE MULTIPLICATION OF TYPHUS RICKETTSIAE
Authors: Greiff Donald , Pinkerton Henry
Published: June 2004

The time of blending the rickettsial inoculum, as also the strain of hen's egg employed, influenced the degree of infection which developed in fertile eggs after the injection of typhus rickettsiae into the yolk sac. By varying these factors, maximal or minimal infections could be obtained.

Eggs incubated at 40°C. developed only minimal rickettsial infection, whereas control eggs incubated at 37.5°C. became heavily infected. Potassium cyanide markedly enhanced rickettsial growth in experiments in which the control eggs developed only minimal infection. Under circumstances such that the control eggs became heavily infected, KCN had no appreciable effect.

Toluidin blue and methylene blue delayed the development of rickettsial infection in the yolk sac, but their rickettsiostatic action under the conditions of these experiments was less marked than that of penicillin and para-aminobenzoic acid.

The rickettsiostatic action resulting from temperature elevation was neutralized by KCN, and hence is believed to be due to the increased activity of the cyanide-sensitive respiratory enzyme (cytochrome oxidase) in the entodermal cells in which the rickettsiae multiply.

The rickettsiostatic action of toluidin blue and methylene blue, though probably also resulting from increased metabolic activity in the entodermal cells, was not neutralized by KCN. This observation is in harmony with the reported observation that dyes of this type furnish an alternative mechanism for intracellular oxidation which is cyanide-insensitive.

The rickettsiostatic action of para-aminobenzoic acid was not neutralized by KCN. No conclusions can be reached at present concerning the mechanism of action of this compound.

Dinitrophenol and several compounds related to para-aminobenzoic acid gave negative results.
HEREDITARY ACHONDROPLASIA IN THE RABBIT
Authors: Brown Wade H. , Pearce Louise
Published: June 2004

An achondroplastic condition in the rabbit has been described. It is present at birth and is characterized by size reduction, by a disproportion of bodily parts, most marked in the extremities, and by an invariably lethal effect. The animals are still-born or die very shortly after birth.

In physical appearance and in the character of the skeletal changes as shown by x-ray photographs, achondroplasia in the rabbit has a remarkable resemblance to the disease in man and in cattle and dogs.

The condition which first occurred in offspring of pure bred Havana rabbits is inherited. In anticipation of the later discussion of this phase of the study (13), it can be stated that the mode of inheritance is on the basis of a simple recessive unit factor and that the appearance of non-achondroplastic transmitters (heterozygotes) is that of normal animals.
STUDIES ON THE ETIOLOGY OF PRIMARY ATYPICAL PNEUMONIA
Authors: Eaton Monroe D. , van Herick William , Meiklejohn Gordon
Published: June 2004

Significant increases in neutralizing antibodies were demonstrated in 42 of a total of 69 persons with a clinical diagnosis of primary atypical pneumonia. Detailed titrations of virus-neutralizing antibodies in a representative group of 28 patients are presented. Increases of four- to 64-fold were demonstrated. Acute-phase titers were 4 or less in 83 per cent and convalescent titers were 16 or over in 86 per cent of these cases.

Only about half of the number of patients having increases in neutralizing antibodies also developed cold agglutinins and agglutinins for the indifferent streptococcus No. 344.

Patients from the Eastern United States as well as those from the Pacific Coast were shown to develop virus-neutralizing antibodies.

Patients with pneumococcal pneumonia and pneumonias caused by influenza virus type A or viruses of the psittacosis group did not have significant increases in neutralizing antibodies for the virus of atypical pneumonia. Cold agglutinins appeared in 3 cases of type A influenzal pneumonia.

Sera from persons with atypical pneumonia, when tested against the 3 most prevalent respiratory viruses isolated from cotton rats and hamsters, failed to neutralize these agents or showed no significant change in neutralization titer.
HEMOGLOBIN PRECIPITATION IN RENAL TUBULES
Authors: Yuile Charles L. , Gold Michael A. , Hinds Ewart G.
Published: June 2004

1. A readily reproducible pathological lesion closely resembling that typical of the "transfusion kidney" has been obtained by the injection of hemoglobin into rabbits having acid urine, whose renal tubules had previously been damaged to a moderate degree by (a) a short period of complete renal ischemia, or (b) the administration of a specific chemical poison—sodium tartrate.

2. It has been found that hemoglobin is precipitated in the tubules of damaged kidneys excreting either acid or alkaline urine, in contrast to the absence of hemoglobin precipitation in normal kidneys.

3. In the acid state hemoglobin casts are more numerous and more persistent than in the alkaline, and are associated with renal functional disturbances, in contrast to the lack of such disturbances when the urine is alkaline.

4. The ultimate outcome, both anatomically and functionally, in any given instance is determined by variations in the degree of tubular damage, the level of hemoglobinemia, and the urinary pH.
STUDIES ON THE NATURE OF RESISTANCE OF GRAM-NEGATIVE BACILLI TO PENICILLIN
Authors: Shwartzman Gregory
Published: June 2004

The susceptibility of E. coli and Salmonella to penicillin is highest in a basal medium devoid of amino acids. Blood serum in certain concentrations, meat infusion broth, yeast extract, and casein hydrolysate interfere with the penicillin activity. The effect is apparently due to the antagonism of certain amino acids in the materials.

Dicarboxyl-monoamino acids (i.e. aspartic, glutamic, and hydroxyglutamic acids and asparagine) cystine, arginine, histidine, and hydroxyproline are capable of suppressing the effect of penicilhn upon Gram-negative organisms.

The antagonism of amino acids is not primarily related to their effect upon the rate of bacterial growth.

It is suggested from the experiments detailed, that the antipenicillin activity is due to the effect of the amino acids upon bacterial metabolism.

Prepassages in media of various concentrations of antagonistic amino acids alter the resistance of E. coli to penicillin. The changes are in inverse relation to the concentration of the antagonists.

The antipenicillin activity of amino acids may be reversed significantly by dl-methionine. The substance, however, reverses only incompletely the antagonism of materials of mixed composition; i.e., casein hydrolysate, meat infusion broth, and serum.

Upon addition of methionine, methionine sulfoxide, and threonine, there occurs a marked enhancement of penicillin susceptibility of broth cultures of Brucella, Eberthella, Salmonella, and Shigella. The enhancement is apparently due to the ability of this amino acid mixture to reverse effectively the action of the antagonists present in the cultures.

Methionine is essential for the enhancement of penicillin susceptibility. Threonine and methionine sulfoxide facilitate the effect of methionine following a reciprocal quantitative relationship.
Central Cities as Engines of Metropolitan Area Growth*
Authors: Solé‐Ollé Albert , Viladecans‐Marsal Elisabet
Published: June 2004

The paper analyzes the role of central cities as engines of economic growth in their metropolitan area. We wonder if there are increasing returns to central city growth at the metropolitan level arising from the positive externalities associated with the unique features of central cities. To answer this question we analyze the causality between the economic growth of Spanish central cities and the growth of the other jurisdictions belonging to their metropolitan area (i.e., the suburbs). The analysis uses population and economic activity data for a sample of 28 Spanish metropolitan areas during 35 years. We use a Vector Error Correction Model (VECM) framework to estimate long‐run equilibrium relationships between the growth of central cities and their suburbs. The combination of panel data and a VECM is an innovative approach that is still being developed in econometrics. The results suggest that central city growth has a long‐run positive effect on the growth of the suburbs. We also inquire as to whether or not this positive effect depends on the size of the central city. The results suggest that the effect is much higher in the case of the largest cities, but that it is also important in the case of the smaller ones.
Chemical analysis of monomers in epoxy resins based on bisphenols F and A
Authors: Pontén A. , Zimerson E. , Sörensen Ö. , Bruze M.
Published: June 2004

Diglycidyl ether of bisphenol A (DGEBA) is the monomer and most important contact allergen in epoxy resin(s) based on bisphenol A (DGEBA‐R). Both thin‐layer chromatography (TLC) and high‐pressure liquid chromatography (HPLC) methods are available for the analysis of products containing DGEBA‐R. With respect to detection and quantification, epoxy resins of the bisphenol F‐type, i.e. epoxy resins containing the isomers of diglycidyl ethers of bisphenol F (DGEBF), are not as well investigated as DGEBA‐R. The isomers of DGEBF are p,p′–DGEBF, o,p′–DGEBF and o,o′–DGEBF. Both p,p′–DGEBF and o,p′–DGEBF have been shown to be contact allergens in humans, and all 3 isomers are sensitizers in the guinea pig maximization test. We aimed (i) to develop HPLC methods for separation and purification of the individual DGEBF isomers, (ii) to detect and quantify the DGEBF isomers in epoxy resins of the bisphenol F‐type and (iii) to evaluate and develop the TLC as a method for the detection of the DGEBF monomers. We found the total content of the DGEBF isomers in the investigated epoxy resins of the bisphenol F‐type to vary from 17.0 to 81.7% w/w. Some of them also contained 0.1–2.4% w/w DGEBA. The HPLC method showed a sensitivity that was 2000–20 000× higher than that obtained with the TLC method for the DGEBF monomers. We concluded that the range of the DGEBF isomer content in epoxy resins of the bisphenol F‐type is approximately the same as the monomer content in liquid compared to solid DGEBA‐R. The relevance of contact allergy to DGEBA‐R can remain unrecognized if the suspected product is an epoxy resin of the bisphenol F‐type, which is analysed with the TLC method.
Selling the Public on Sustainable Watershed Conservation
Authors: Pugh Jeff , Sarmiento Fausto O.
Published: June 2004

Abstract:  The city of Quito, Ecuador, began working in 2000 to protect the ecologically fragile watershed area for its drinking water. In order to protect the Papallacta watershed, the independent Fund for the Conservation of Watersheds (FONAG) was launched to finance and manage economically sound sustainability projects in the area. FONAG is funded in part through start up grants from several organisations and a 1 per cent fee on all Quito water bills, but it has been unable to build an endowment sizeable enough to begin implementing conservation projects. We measure perceptions of the fund among Quito's university–based residents in two settings and evaluate the quality of the fund's proposed communication campaign based on existing communication theory. Further, we propose an adapted environmental education model based on a synthesis of existing theory and the empirical findings from our examination of the FONAG example. The Papallacta case study illuminates the potential strengths and weaknesses of the cultural ecology and political will of this type of collaborative sustainability project for addressing water problems in a developing country in a mountainous setting, centred around the themes of water conservation and sustainable development.
The Defence of Iturbide or the Defence of Federalism? Rebellion in Jalisco and the Conspiracy of the Calle de Celaya, 1824
Authors: Andrews Catherine
Published: June 2004

Abstract:  This article investigates a planned rebellion in favour of Agustín de Iturbide organised by a group of his supporters in Guadalajara, Jalisco, in 1824. It shows that the rebels in Guadalajara were in close communication with a second cadre of conspirators in Mexico City. By examining the various plans drawn up by the rebels, the article demonstrates the existence of two separate and apparently contradictory aims for the rebellion: the return of Iturbide and the defence of federalism. The question posed by the paper is: does this discovery indicate a coalition between federalists and iturbidistas against the central government in Mexico City?
Alprazolam is relatively more toxic than other benzodiazepines in overdose
Authors: Isbister Geoffrey K. , O'Regan Luke , Sibbritt David , Whyte Ian M.
Published: June 2004

Aims

To describe alprazolam poisoning and the relative toxicity of alprazolam compared with other benzodiazepines.

Methods

A database of consecutive poisoning admissions to a regional toxicology service was searched to identify consecutive benzodiazepine deliberate self poisonings, which were coded as alprazolam, diazepam or other benzodiazepine. Major outcomes used were length of stay (LOS), intensive care (ICU) admission, coma (GCS < 9), flumazenil administration and requirement for mechanical ventilation. Prescription data were obtained for benzodiazepines for the study period.

Results

There were 2063 single benzodiazepine overdose admissions: 131 alprazolam overdoses, 823 diazepam overdoses and 1109 other benzodiazepine overdoses. The median LOS for alprazolam overdoses was 19 h which was 1.27 (95% CI 1.04, 1.54) times longer compared with other benzodiazepines by multiple linear regression. For patients with alprazolam overdoses, 22% were admitted to ICU which was 2.06 (95% CI 1.27, 3.33) times more likely compared with other benzodiazepines after multivariate analysis adjusting for age, dose, gender, time to ingestion and co‐ingested drugs. Flumazenil was administered to 14% of alprazolam patients and 16% were ventilated, which was significantly more than for other benzodiazepine overdoses (8% and 11%, respectively). Twelve percent of alprazolam overdoses had a GCS < 9 compared with 10% for other benzodiazepines. From benzodiazepine prescription data, total alprazolam prescriptions in Australia increased from 0.13 million in 1992 to 0.41 million in 2001. Eighty five percent of prescriptions were for panic disorder, anxiety, depression or mixed anxiety/depression.

Conclusions

Alprazolam was significantly more toxic than other benzodiazepines. The increased prescription of alprazolam to groups with an increased risk of deliberate self poisoning is concerning and needs review.
Effects of hydrofluoroalkane formulations of ciclesonide 400 µg once daily vs fluticasone 250 µg twice daily on methacholine hyper‐responsiveness in mild‐to‐moderate persistent asthma
Authors: Lee Daniel K. C. , Haggart Kay , Currie Graeme P. , Bates Caroline E. , Lipworth Brian J.
Published: June 2004

Aims  There are no data comparing the relative efficacy of hydrofluoroalkane (HFA) formulations of ciclesonide (CIC) and fluticasone propionate (FP) on airway hyper‐responsiveness, in mild‐to‐moderate persistent asthma. We therefore elected to evaluate the comparative efficacy of HFA pressurized metered‐dose inhaler formulations of CIC and FP, assessing methacholine challenge, in addition to exhaled nitric oxide, lung function, diary cards and quality of life.

Methods  Nineteen mild‐to‐moderate asthmatic patients completed the study per protocol in randomized, double‐blind, double‐dummy, crossover fashion. Patients were required to stop their usual inhaled corticosteroid therapy for the duration of the study. Pa‐tients were commenced instead on salmeterol (SM) 50 µg one puff twice daily + montelukast (ML) 10 mg once daily for 2‐week washout periods prior to each randomized treatment, in order to prevent dropouts. Patients received 4 weeks of either CIC 200 µg two puffs once daily (08.00 h) + CIC‐placebo (PL) two puffs once daily (20.00 h) + FP‐PL two puffs twice daily (08.00 h and 20.00 h), or FP 125 µg two puffs twice daily (08.00 h and 20.00 h) + CIC‐PL two puffs twice daily (08.00 h and 20.00 h). SM + ML were withheld for 72 h prior to post‐washout visits and CIC or FP was withheld for 24 h prior to study visits.

Results  There was no significant difference between CIC vs. FP for the primary outcome of methacholine PC20 as doubling dilution (dd) shift from respective baseline; mean difference: 0.4 dd (95% CI −0.4, 1.2). Moreover, there was no difference between treatments for the sequence of CIC first vs FP second; mean difference: 0.2 dd (95% CI −1.3, 1.7) or FP first vs CIC second; mean difference: 0.9 dd (95% CI −0.1, 1.8). There were also no differences for other secondary outcomes between treatments, either respective or irrespective of sequence, as change from baseline.

Conclusions  There were no differences between 4 weeks of CIC 400 µg once daily and FP 250 µg twice daily on methacholine hyper‐responsiveness in mild‐to‐moderate persistent asthma. Longer‐term studies are indicated to evaluate their relative efficacy on asthma exacerbations.
Acute and clinically relevant drug‐induced liver injury: a population based case‐control study
Authors: De Abajo Francisco J. , Montero Dolores , Madurga Mariano , Rodríguez Luis A. García
Published: June 2004

Aims To provide quantitative information about the absolute and relative risks of acute and clinically relevant drug‐induced liver injury.

Methods We performed a population‐based case‐control study using the UK‐based General Practice Research Database as the source of information. A total of 1636792 persons subjects aged 5–75 years old registered in the database from 1 January, 1994 to 31 December, 1999 were followed‐up for a total of 5404705 person‐years. Cases were identified by an exhaustive computer search, then reviewed manually and finally validated against the clinical records. Only idiopathic cases serious enough to be referred to hospital or a consultant were selected. A total of 5000 controls were randomly sampled from the person‐time of study cohort. Current users were defined if a prescription ended within 15 days of the index date, and nonusers if there was no prescription before the index date.

Results One hundred and twenty‐eight patients were considered as valid cases, being the crude incidence rate of 2.4 (95% confidence interval: 2.0, 2.8) per 100 000 person‐years. The strongest associations were found with chlorpromazine (adjusted odds ratio (AOR); 95% CI = 416; 45, 3840), amoxicillin/clavulanic acid (AOR = 94.8; 27.8, 323), flucloxacillin (AOR = 17.7; 4.4, 71.0), macrolides (AOR = 6.9; 2.3, 21.0), tetracyclines (AOR = 6.2; 2.4, 15.8); metoclopramide (AOR = 6.2; 1.8, 21.3); chlorpheniramine (AOR = 9.6; 1.9, 49.7); betahistine (AOR = 15.3; 2.9, 80.7); sulphasalazine (AOR = 25.5; 6.0, 109); azathioprine (AOR = 10.5; 1.4, 76.4), diclofenac (AOR = 4.1; 1.9, 8.8) and antiepileptics (AOR = 5.1; 1.9, 13.7). A dose‐effect was apparent for diclofenac, amoxicillin/clavulanic acid and flucloxacillin. The combination of two or more hepatotoxic drugs increased the risk by a factor of 6. The highest crude incidence rates were found for chlorpromazine, azathioprine, and sulfasalazine (about 1 per 1000 users).

Conclusions Idiopathic, acute and clinically relevant liver injury, which has the use of drugs as the most probable aetiology, is a rare event in the general population. The relative risks of 40 drugs/therapeutic classes are provided, along with the crude incidence rates for 15 of them where a statistical association was found.
A novel four transmembrane spanning protein, CLP24
Authors: Kearsey Jonathan , Petit Silvere , De Oliveira Catherine , Schweighoffer Fabien
Published: June 2004

A novel hypoxically regulated intercellular junction protein (claudin‐like protein of 24 kDa, CLP24) has been identified that shows homology to the myelin protein 22/epithelial membrane protein 1/claudin family of cell junction proteins, which are involved in the modulation of paracellular permeability. The CLP24 protein contains four predicted transmembrane domains and a C‐terminal protein–protein interaction domain. These domains are characteristic of the four transmembrane spanning (tetraspan) family of proteins, which includes myelin protein 22, and are involved in cell adhesion at tight, gap and adherens junctions. Expression profiling analyses show that CLP24 is highly expressed in lung, heart, kidney and placental tissues. Cellular studies confirm that the CLP24 protein localizes to cell–cell junctions and co‐localizes with the β‐catenin adherens junction‐associated protein but not with tight junctions. Over‐expression of CLP24 results in decreased adhesion between cells, and functional paracellular flux studies confirm that over‐expression of the CLP24 protein modulates the junctional barrier function. These data therefore suggest that CLP24 is a novel, hypoxically regulated tetraspan adherens junction protein that modulates cell adhesion, paracellular permeability and angiogenesis.
Large‐scale overproduction, functional purification and ligand affinities of the His‐tagged human histamine H1 receptor
Authors: Ratnala Venkata R. P. , Swarts Herman G. P. , VanOostrum Jenny , Leurs Rob , DeGroot Huub J. M. , Bakker Remko A. , DeGrip Willem J.
Published: June 2004

This report describes an efficient strategy for amplified functional purification of the human H1 receptor after heterologous expression in Sf9 cells. The cDNA encoding a C‐terminally histidine‐tagged (10xHis) human histamine H1 receptor was used to generate recombinant baculovirus in a Spodoptera frugiperda‐derived cell line (IPLB‐Sf9). As judged from its ligand affinity profile, functional receptor could be expressed at high levels (30–40 pmol per 106 cells). Rapid proteolysis in the cell culture led to limited fragmentation, without loss of ligand binding, but could be efficiently suppressed by including the protease inhibitor leupeptin during cell culture and all subsequent manipulations. Effective solubilization of functional receptor with optimal recovery and stability required the use of dodecylmaltoside as a detergent in the presence of a high concentration of NaCl and of a suitable inverse agonist. Efficient purification of solubilized receptor could be achieved by affinity chromatography over nickel(II) nitrilotriacetic acid resin. Functional membrane reconstitution of purified H1 receptor was accomplished in mixed soybean lipids (asolectin). The final proteoliposomic H1 receptor preparation has a purity greater than 90% on a protein basis and displays a ligand binding affinity profile very similar to the untagged receptor expressed in COS‐7 cells. In conclusion, we are able to produce pharmacologically viable H1 receptor in a stable membrane environment allowing economic large‐batch operation. This opens the way to detailed studies of structure–function relationships of this medically and biologically important receptor protein by 3D‐crystallography, FT‐IR spectroscopy and solid‐state NMR spectroscopy.
Molecular and biochemical characterization of d‐phosphoglycerate dehydrogenase from Entamoeba histolytica
Authors: Ali Vahab , Hashimoto Tetsuo , Shigeta Yasuo , Nozaki Tomoyoshi
Published: June 2004

A putative phosphoglycerate dehydrogenase (PGDH), which catalyzes the oxidation of d‐phosphoglycerate to 3‐phosphohydroxypyruvate in the so‐called phosphorylated serine metabolic pathway, from the enteric protozoan parasite Entamoeba histolytica was characterized. The E. histolytica PGDH gene (EhPGDH) encodes a protein of 299 amino acids with a calculated molecular mass of 33.5 kDa and an isoelectric point of 8.11. EhPGDH showed high homology to PGDH from bacteroides and another enteric protozoan ciliate, Entodinium caudatum. EhPGDH lacks both the carboxyl‐terminal serine binding domain and the 13–14 amino acid regions containing the conserved Trp139 (of Escherichia coli PGDH) in the nucleotide binding domain shown to be crucial for tetramerization, which are present in other organisms including higher eukaryotes. EhPGDH catalyzed reduction of phosphohydroxypyruvate to phosphoglycerate utilizing NADH and, less efficiently, NADPH; EhPGDH did not utilize 2‐oxoglutarate. Kinetic parameters of EhPGDH were similar to those of mammalian PGDH, for example the preference of NADH cofactor, substrate specificities and salt‐reversible substrate inhibition. In contrast to PGDH from bacteria, plants and mammals, the EhPGDH protein is present as a homodimer as demonstrated by gel filtration chromatography. The E. histolytica lysate contained PGDH activity of 26 nmol NADH utilized per min per mg of lysate protein in the reverse direction, which consisted 0.2–0.4% of a total soluble protein. Altogether, this parasite represents a unique unicellular protist that possesses both phosphorylated and nonphosphorylated serine metabolic pathways, reinforcing the biological importance of serine metabolism in this organism. Amino acid sequence comparison and phylogenetic analysis of various PGDH sequences showed that E. histolytica forms a highly supported monophyletic group with another enteric protozoa, cilliate E. caudatum, and bacteroides.
KIPase activity is a novel caspase‐like activity associated with cell proliferation
Authors: Medina‐Palazon Cahora , Bernard Emmanuelle , Frost Victoria , Morley Simon , Sinclair Alison J.
Published: June 2004

A novel caspase‐like activity, which is directly regulated with cell proliferation is a candidate to regulate the abundance of the cyclin‐dependent kinase inhibitor, p27KIP1, in human lymphoid cells. This activity, which we term KIPase activity, can also cleave a subset of caspase substrates. Here we demonstrate that KIPase is a novel enzyme distinct from any of the previously characterized human caspases. We show that KIPase is active in a variety of cell lineages, its activity is associated with the proliferation of the human T‐cell line, Jurkat, and is not inhibited by the broad spectrum caspase inhibitor z‐VAD‐fmk. Gel filtration analysis revealed that KIPase has a native molecular mass of approximately 100–200 kDa. Furthermore, the activity of KIPase does not change during apoptosis induced by either ligation of FAS or exposure of cells to etoposide. The uniqueness of KIPase is demonstrated by the fact that none of the human caspases tested (1–10) are able to cleave a specific KIPase substrate (Ac‐DPSD‐AMC) and that an aldehyde modified derivative of the DPSD tetra peptide is unable to inhibit caspases, but is a good inhibitor of KIPase activity. This supports a hypothesis whereby KIPase is a currently unidentified caspase‐like enzyme which regulates the abundance of p27KIP1 in a proliferation‐dependent manner.
Altered inactivation pathway of factor Va by activated protein C in the presence of heparin
Authors: Nicolaes Gerry A. F. , Sørensen Kristoffer W. , Friedrich Ute , Tans Guido , Rosing Jan , Autin Ludovic , Dahlbäck Björn , Villoutreix Bruno O.
Published: June 2004

Inactivation of factor Va (FVa) by activated protein C (APC) is a predominant mechanism in the down‐regulation of thrombin generation. In normal FVa, APC‐mediated inactivation occurs after cleavage at Arg306 (with corresponding rate constant k′306) or after cleavage at Arg506 (k506) and subsequent cleavage at Arg306 (k306). We have studied the influence of heparin on APC‐catalyzed FVa inactivation by kinetic analysis of the time courses of inactivation. Peptide bond cleavage was identified by Western blotting using FV‐specific antibodies. In normal FVa, unfractionated heparin (UFH) was found to inhibit cleavage at Arg506 in a dose‐dependent manner. Maximal inhibition of k506 by UFH was 12‐fold, with the secondary cleavage at Arg306 (k306) being virtually unaffected. In contrast, UFH stimulated the initial cleavage at Arg306 (k′306) two‐ to threefold. Low molecular weight heparin (Fragmin®) had the same effects on the rate constants of FVa inactivation as UFH, but pentasaccharide did not inhibit FVa inactivation. Analysis of these data in the context of the 3D structures of APC and FVa and of simulated APC–heparin and FVa–APC complexes suggests that the heparin‐binding loops 37 and 70 in APC complement electronegative areas surrounding the Arg506 site, with additional contributions from APC loop 148. Fewer contacts are observed between APC and the region around the Arg306 site in FVa. The modeling and experimental data suggest that heparin, when bound to APC, prevents optimal docking of APC at Arg506 and promotes association between FVa and APC at position Arg306.
Contribution of Tyr712 and Phe716 to the activity of human RNase L
Authors: Nakanishi Masayuki , Yoshimura Akihiro , Ishida Norihisa , Ueno Yoshihito , Kitade Yukio
Published: June 2004

Ribonuclease L (RNase L) is a key enzyme in the 2‐5A host defense system, and its activity is strictly regulated by an unusual 2′,5′‐linked oligoadenylate (2‐5A). A bipartite model, in which the N‐terminal half of RNase L is responsible for the 2‐5A binding and the C‐terminal half alone is able to hydrolyse the substrate RNA, has been proposed on the basis of the results of deletion mutant analyses [Dong, B. & Silverman, R.H. (1997) J. Biol. Chem.272, 22236–22242]. Above all, the region between Glu711 and His720 was revealed to be essential for RNA binding and/or hydrolysis. To dissect the function of the region, we performed scanning mutagenesis over the 10 residues of glutathione S‐transferase (GST)‐fusion RNase L. Among the single amino acid mutants examined, Y712A and F716A resulted in a significant decrease of RNase activity with a reduced RNA binding acitivity. The losses of the RNase activity were not restored by its conservative mutation, whereas the RNA binding activity was enhanced in the case of Y712F. These results indicate that both Tyr712 and Phe716 provide the enzyme with a RNA binding activity and catalytic environment.
Effect of priming on activation and localization of phospholipase D‐1 in human neutrophils
Authors: Cadwallader Karen A. , Uddin Mohib , Condliffe Alison M. , Cowburn Andrew S. , White Jessica F. , Skepper Jeremy N. , Ktistakis Nicholas T. , Chilvers Edwin R.
Published: June 2004

Phospholipase D (PLD) plays a major role in the activation of the neutrophil respiratory burst. However, the repertoire of PLD isoforms present in these primary cells, the precise mechanism of activation, and the impact of cell priming on PLD activity and localization remain poorly defined. RT‐PCR analysis showed that both PLD1 and PLD2 isoforms are expressed in human neutrophils, with PLD1 expressed at a higher level. Endogenous PLD1 was detected by immunoprecipitation and Western blotting, and was predominantly membrane‐associated under control and primed/stimulated conditions. Immunofluorescence showed that PLD had a punctate distribution throughout the cell, which was not altered after stimulation by soluble agonists. In contrast, PLD localized to the phagolysosome membrane after ingestion of nonopsonized zymosan particles. We also demonstrate that tumour necrosis factor α greatly potentiates agonist‐stimulated PLD activation, myeloperoxidase release, and superoxide anion generation, and that PLD activation occurs via a phosphatidylinositol 3‐kinase‐sensitive and brefeldin‐sensitive ADP‐ribosylation factor GTPase‐regulated mechanism. Moreover, propranolol, which causes an increase in PLD‐derived phosphatidic acid accumulation, caused a selective increase in agonist‐stimulated myeloperoxidase release. Our results indicate that priming is a critical regulator of PLD activation, that the PLD‐generated lipid products exert divergent effects on neutrophil functional responses, that PLD1 is the major PLD isoform present in human neutrophils, and that PLD1 actively translocates to the phagosomal wall after particle ingestion.
Amino acids at the N‐ and C‐termini of human glutamate carboxypeptidase II are required for enzymatic activity and proper folding
Authors: Bařinka Cyril , Mlčochová Petra , Šácha Pavel , Hilgert Ivan , Majer Pavel , Slusher Barbara S. , Hořejší Václav , Konvalinka Jan
Published: June 2004

Human glutamate carboxypeptidase II (GCPII) is a co‐catalytic metallopeptidase and its putative catalytic domain is homologous to the aminopeptidases from Vibrio proteolyticus and Streptomyces griseus. In humans, the enzyme is expressed predominantly in the nervous system and the prostate. The prostate form, termed prostate‐specific membrane antigen, is overexpressed in prostate cancer and is used as a diagnostic marker of the disease. Inhibition of the form of GCPII expressed in the central nervous system has been shown to protect against ischemic injury in experimental animal models. Human GCPII consists of 750 amino acids, and six individual domains were predicted to constitute the protein structure. Here, we report the analysis of the contribution of these putative domains to the structure/function of recombinant human GCPII. We cloned 13 mutants of human GCPII that are truncated or extended at one or both the N‐ and C‐termini of the GCPII sequence. The clones were used to generate stably transfected Drosophila Schneider's cells, and the expression and carboxypeptidase activities of the individual protein products were determined. The extreme C‐terminal region of human GCPII was found to be critical for the hydrolytic activity of the enzyme. The deletion of as few as 15 amino acids from the C‐terminus was shown to completely abolish the enzymatic activity of GCPII. Furthermore, the GCPII carboxypeptidase activity was abrogated upon removal of more than 60 amino acid residues from the N‐terminus of the protein. Overall, these results clearly show that amino acid segments at the N‐ and C‐termini of the ectodomain of GCPII are essential for its carboxypeptidase activity and/or proper folding.
Peroxidase catalyzed nitration of tryptophan derivatives
Authors: Sala Alberto , Nicolis Stefania , Roncone Raffaella , Casella Luigi , Monzani Enrico
Published: June 2004

The enzymatic nitration of tryptophan derivatives by oxidation of nitrite has been studied using lactoperoxidase and horseradish peroxidase, and compared with the chemical nitration produced by nitrogen dioxide and peroxynitrite. HPLC, mass spectra and NMR analysis of the mixture of products clearly show that nitration occurs at position 4‐, 6‐, 7‐, and N1 of the indole ring, and nitrosation at position N1. Kinetic studies performed on peroxidase/NO2–/H2O2 systems showed substrate saturation behavior with all the tryptophan derivatives employed. The rate dependence on nitrite concentration was found to be linear with horseradish peroxidase while it exhibited saturation behavior with lactoperoxidase. The composition of the product mixture depends on the nitrating agent. While the production of 4‐nitro, 6‐nitro, 7‐nitro and N1‐nitro derivatives follows a similar trend, indicating that they are formed according to a similar mechanism, the ratio between the N1‐nitroso derivative and other derivatives depends markedly on the nitrite concentration when tryptophan modification is performed by the peroxidase/H2O2/nitrite systems. Analysis of the data indicates that at low nitrite concentration the enzymatic reaction occurs through the classical peroxidase cycle. At high nitrite concentration the reaction proceeds through a different intermediate that we assume to be a protein bound peroxynitrite species.
Spatial nonstationarity and scale‐dependency in the relationship between species richness and environmental determinants for the sub‐Saharan endemic avifauna
Authors: Foody Giles M.
Published: June 2004

Aim  This article aims to test for and explore spatial nonstationarity in the relationship between avian species richness and a set of explanatory variables to further the understanding of species diversity variation.

Location  Sub‐Saharan Africa.

Methods  Geographically weighted regression was used to study the relationship between species richness of the endemic avifauna of sub‐Saharan Africa and a set of perceived environmental determinants, comprising the variables of temperature, precipitation and normalized difference vegetation index.

Results  The relationships between species richness and the explanatory variables were found to be significantly spatially variable and scale‐dependent. At local scales > 90% of the variation was explained, but this declined at coarser scales, with the greatest sensitivity to scale variation evident for narrow ranging species. The complex spatial pattern in regression model parameter estimates also gave rise to a spatial variation in scale effects.

Main conclusions  Relationships between environmental variables are generally assumed to be spatially stationary and conventional, global, regression techniques are therefore used in their modelling. This assumption was not satisfied in this study, with the relationships varying significantly in space. In such circumstances the average impression provided by a global model may not accurately represent conditions locally. Spatial nonstationarity in the relationship has important implications, especially for studies of species diversity patterns and their scaling.