Distribution of free-living amoebae (FLA) during preparation and supply of drinking water

Free-living amoebae (FLA) are widely distributed in aquatic environments with increasing importance in hygienic, medical and ecological relationship to man. Only few data are available about abundances of these protozoa in the treatment of drinking water and standards in the management of water quality are not suitable for detection of FLA. Prevalence of FLA were investigated within six selected German drinking water treatment plants in the course of the purification-process of surface water and in a subsequent drinking water supply. The data give a short survey about the prevalence and reduction of FLA in processing and supply of drinking water.

Managing a sound industrial radiography radiation safety program

This article was developed to provide new radiation safety officers with the basic information needed for ensuring safety, security, and control of industrial radiography sources and to discuss licensing requirements and other information pertaining to the management of radiation safety programs associated with these sources.

The natural history and longitudinal study of the surgically corrected clubfoot

Surgical treatment for clubfoot has been largely directed at finding the best one-stage operation for the resistant clubfoot. Eighteen patients with 27 clubfeet (average follow-up 11 years since first surgery; range, 3.5-24 years) were reviewed. More than one clubfoot operation was required in 56% of cases. Forty-six percent were corrected after one surgery; 33% required a second surgery and 14% required a third operation. One patient with particularly severe feet required a fourth operation on each foot. The mean age at the time of surgery was 1.26 years, 5.12 years, and 8 years for the first, second, and third operations, respectively. The first operation consisted of a soft-tissue release. The second and third operations consisted of more extensive soft-tissue release and various rearfoot and forefoot procedures. Radiographic values revealed an AP talocalcaneal angle of 18 degrees, AP talo-first metatarsal angle of 6 degrees, lateral talocalcaneal angle of 29.6 degrees, lateral talo-first metatarsal angle of 15 degrees, and calcaneo-first metatarsal angle of 143 degrees. At follow-up all patients had adequate function as determined by personal interview and clinical examination. We conclude that correction of resistant congenital clubfoot often requires more than one surgery, not because of a "failed first operation," but due to dynamic muscle imbalances that may not be fully recognized in infancy and early childhood. Thus, the need for a second operation should not be perceived as a failure of the first, but as part of the natural history of congenital clubfoot.

Effective dose equivalent estimates in diagnostic radiology with single dosimetry

In many external exposure situations dose estimates obtained from personal monitors significantly overestimate the Effective Dose Equivalent (EDE). This occurs particularly when the body is not uniformly exposed due to the irradiation conditions or due to protective shielding (i.e., lead apron) of portions of the body (NCRP 1995). Many numerical relationships between monitoring data and EDE have been proposed to perform more accurate dose estimates (Gill et al. 1980; Faulkner and Harrison 1988; Webster 1989; Niklason et al. 1994; Berger et al. 1995). Also, organizations such as the Conference of Radiation Control Program Directors (CRCPD), the National Council on Radiation Protection and Measurements (NCRP) and the Electric Power Research Institute (EPRI) have published recommendations on this subject (CRCPD 1995; NCRP 1995; EPRI 1998). Before implementing the use of any of the proposed relationships, they should be thoroughly reviewed so that proper practices are chosen and monitoring data are properly evaluated. It is also important for each facility to be aware of the regulatory requirements in their state such as if the methodology is approved for use, which method and for whom can the EDE be applied. The United States Nuclear Regulatory Agency (NRC) does not currently permit dose weighting for any of its licensees. The EPRI study performed in 1997 was initiated by the NRC to determine how viable dose weighting would be, and for which NRC licensee population. This paper discusses numerical relationships for external exposure in diagnostic radiology for estimating EDE in a single-monitor program.

Measuring earthquakes from optical satellite images

Système pour l'Observation de la Terre images are used to map ground displacements induced by earthquakes. Deformations (offsets) induced by stereoscopic effect and roll, pitch, and yaw of satellite and detector artifacts are estimated and compensated. Images are then resampled in a cartographic projection with a low-bias interpolator. A subpixel correlator in the Fourier domain provides two-dimensional offset maps with independent measurements approximately every 160 m. Biases on offsets are compensated from calibration. High-frequency noise (0.125 m(-1)) is approximately 0.01 pixels. Low-frequency noise (lower than 0.001 m(-1)) exceeds 0.2 pixels and is partially compensated from modeling. Applied to the Landers earthquake, measurements show the fault with an accuracy of a few tens of meters and yields displacement on the fault with an accuracy of better than 20 cm. Comparison with a model derived from geodetic data shows that offsets bring new insights into the faulting process.

Vannella sp. harboring Microsporidia-like organisms isolated from the contact lens and inflamed eye of a female keratitis patient

Viable Hartmannella sp. and two strains of Vannella sp.--but no Acanthamoebae--multiplied on NN-agar inoculated with pieces of the contact lens from a female keratitis patient. Within the cytoplasm of one Vannella isolate, intracellular parasites could be observed whose earliest stages were developing within the nucleus, resembling those Microsporidia-like parasites seen within Vannella isolated recently from a warm tapwater system. This assumption was also confirmed by electron microscopy. In swabs taken directly from the cornea, Pseudomonas aeruginosa were identified, but they did not yield any growth of amebas in culture. However, cocultivation of parasite-free Vannella strains with the above-mentioned swab matter resulted in infected amebas harboring the same intracellular parasites seen before. This infection could be established only if the corresponding spores were present as infective agents in the swab matter. The successful treatment of the patient with antibiotics supports the assumption that P. aeruginosa was the main cause of the corneal ulceration. The extent to which the Microsporidia-like organisms may have been involved in the development of keratitis remains a matter of discussion.

Managing a sound portable gauge radiation safety program

At some construction engineering companies, individuals with no background in radiation safety sometimes are assigned the not always welcome title of Radiation Safety Officer (RSO). With this new title comes the responsibility of ensuring that portable gauges are used safely at their facilities and in tile field. These newly appointed RSOs sometimes lack the knowledge and experience needed to manage a radiation safety program. This article was developed to provide the basic information needed to work confidently and safely around these instruments and to discuss licensing requirements and other information pertaining to the management of a portable gauge radiation safety program.

'Candidatus Odyssella thessalonicensis' gen. nov., sp. nov., an obligate intracellular parasite of Acanthamoeba species

An intracellular bacterium, strain L13, was observed infecting an environmental isolate of an Acanthamoeba species. The bacterium could not be recovered on axenic medium but was recovered and cultivated in vitro using cultures of Acanthamoeba polyphaga. The 16S rRNA gene sequence of L13 was found to be new, sharing less than 84% similarity with other sequences in the GenBank/EMBL database. L13 was found to be a member of the alpha-Proteobacteria, sharing an evolutionary line of descent with a group of uniquely obligate intracellular organisms comprised of Caedibacter and Holospora species and the NHP bacterium. Viable bacteria appeared to be highly motile within amoebae. Ultrastructural analysis of the bacterium demonstrated that it is rod-shaped and possesses a typical Gram-negative cell wall, but has no other outstanding features except small vesicle-like structures often associated with the outer surface of each bacterium. The host range of L13 was found to be limited to the genus Acanthamoeba. In A. polyphaga, L13 infection was slow to manifest when cultures were incubated below 30 degrees C, but at higher temperatures bacteria multiplied prolifically and induced host cell lysis. The protein profile of the bacterium purified from the amoebae was assessed by SDS-PAGE and its G+C content was estimated to be 41 mol%. Although these results support the proposal of L13 as a new species, its obligate intracellular nature prevented isolation of a definitive type strain. L13 is therefore proposed as 'Candidatus Odyssella thessalonicensis' gen. nov., sp. nov.

Basic radiation protection considerations in dental practice

This article provides basic guidance to radiation safety professionals unfamiliar with dental radiography on how to optimize the use of x-ray equipment and maintain occupational and non-occupational doses ALARA. Topics discussed in this article include basic protective measures commonly used to minimize the patient and operator's exposure to radiation, recommendations for the development of operating procedures, and the performance of compliance audits in dental practice.

Imipramine and diet counseling with psychological support in the treatment of obese binge eaters: a randomized, placebo-controlled double-blind study

OBJECTIVE

This study with 31 obese binge eaters (body mass index [BMI] 39.5+/-8.6 kg/m(2) [SD]) was designed to assess whether diet counseling with psychological support and imipramine or placebo has an effect on the frequency of binge eating, body weight, and depression during an 8-week treatment phase. This was followed by an open medication-free phase of 6 months of continuous diet counseling with psychological support.

METHODS

Randomized double-blind placebo-controlled study of 8 weeks followed by an open phase of 6 months. Patients were evaluated in medical visits by a semistructured videotaped interview, psychometric questionnaires, and hematochemical parameters.

RESULTS

From Week 0 to 8, a significant reduction in binge frequency occurred in both treatment conditions (7.1+/-4.1 to 2.8+/-3.0 binges per week [imipramine] vs. 7.1+/-4.1 to 5.4+/-5.1 [placebo], p<.01). Patients on imipramine lost -2.2+/-1.8 kg compared to placebo-treated subjects (+0.2+/-3.3 kg, p<.001). On follow-up, only the patients initially treated with imipramine continued to lose weight (-5.1+/-2.8 kg [imipramine] vs. 2.2+/-6.8 kg [placebo], p<.001 [differences to Week 0]). While both treatment conditions were associated with significant improvements on a rater's measure of depressive symptoms (Hamilton Depression Scale) at Week 8, only the patients treated with imipramine still showed a significant improvement at Week 32. Scores on the Self Depression Rating Scale did not show a group difference but a significant reduction at Weeks 8 and 32, compared to baseline.

DISCUSSION

These results suggest that adding low-dose imipramine to diet counseling with psychological support helps patients losing weight even for at least 6 months off medication. The effect might include a psychological priming of weight loss during the double-blind phase that continues at least for half a year after stopping the drug.

Intracellular bacteria of Acanthamoebae resembling Legionella spp. turned out to be Cytophaga sp

Acanthamoeba sp. isolated from the drinking water system of a hospital harboured gram-negative bacteria multiplying inside phagosomes and within the cytoplasm of their host cells. According to their morphology demonstrated by electron microscopy they resembled Llaps (Legionella-like amoebal pathogens) but turned out to be Cytophaga sp. as shown by a typical profile of cellular fatty acids obtained by means of gas-liquid chromatography.

Determination of 129I in atmospheric samples by accelerator mass spectrometry

A method for the radiochemical extraction of 129I from atmospheric charcoal filters and its measurement by accelerator mass spectrometry is presented. Either the 129I concentration or the 129I/127I atom ratio can be determined in the sample. With this method, air filters from Seville, in the Southwest of Spain (37.4 degrees N, 6 degrees W) have been analyzed. Sensitivities in the order of 10(4) atoms/m3 for 129I concentrations and 10(-10) for 129I/127I atom ratios are obtained. AMS measurements are performed with the 6 MV tandem accelerator at the ETH-Hönggerberg in Zurich.

Biophysical characterization of lithostathine. Evidences for a polymeric structure at physiological pH and a proteolysis mechanism leading to the formation of fibrils

Lithostathine is a calcium carbonate crystal habit modifier. It is found precipitated under the form of fibrils in chronic calcifying pancreatitis or Alzheimer's disease. In order to gain better insight into the nature and the formation of fibrils, we have expressed and purified recombinant lithostathine. Analytical ultracentrifugation and quasi-elastic light scattering techniques were used to demonstrate that lithostathine remains essentially monomeric at acidic pH while it aggregates at physiological pH. Analysis of these aggregates by electron microscopy showed an apparently unorganized structure of numerous monomers which tend to precipitate forming regular unbranched fibrils. Aggregated forms seem to occur prior to the apparition of fibrils. In addition, we have demonstrated that these fibrils resulted from a proteolysis mechanism due to a specific cleavage of the Arg(11)-Ile(12) peptide bond. It is deduced that the NH(2)-terminal undecapeptide of lithostathine normally impedes fiber formation but not aggregation. A theoretical model explaining the formation of amyloid plaques in neurodegenerative diseases or stones in lithiasis starting from lithostathine is described. Therefore we propose that lithostathine, whose major function is unknown, defines a new class of molecules which is activated by proteolysis and is not involved in cytoskeleton nor intermediate filament functions.

Radiation safety instruction for non-radiation workers

In today's society, neglecting to provide adequate hazard-awareness instruction to workers can be successfully used to file suit against institutions where radioactive material (RAM) or radiation generating devices (RGDs) are used. Because of the lack of instruction, in some cases, just the perceived risk (even where no significant exposure to radiation existed) has proven to be more important than the actual risk. Groups of non-radiation workers such as custodian, maintenance and laboratory personnel, whose duties may require them to work in the vicinity of RAM and RGDs, sometimes do not receive proper hazard-awareness instruction. Misinterpretation of the applicable hazard-awareness regulations is a reason why institutions sometimes fail to instruct their workers. The objectives of this paper are to help radiation safety program managers become more aware of the importance of having well-instructed non-radiological personnel and to develop and provide basic information to help implement an effective hazard-awareness instruction program for workers. Topics discussed in this paper include regulatory aspects regarding the instruction to non-radiation workers, a list of radiological incidents that could have been prevented with proper instruction to workers and recommendations for the development and implementation of an effective instruction program.

On the analysis of iodine-129 and iodine-127 in environmental materials by accelerator mass spectrometry and ion chromatography

Based on a review of literature about the abundances of 129I (T1/2 = 15.7 Ma) in the environment we show that there is a severe lack of knowledge, in particular about natural, pre-nuclear levels. Among the two analytical techniques which are sensitive enough to investigate 129I in environmental materials, namely radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS), only AMS is capable of covering the natural, pre-nuclear levels. Since such AMS measurements require chemical separation of iodine from the matrix, a wide variety of separation schemes are necessary for environmental analyses. We report here on such schemes for the analysis of soils, plants and soft tissue. They are applied exemplarily to analyses of soils from the vicinity of Chernobyl. For chemical separations prior to analysis, contamination control and blank analyses are essential. Here, we discuss quality control procedures in detail, both for RNAA and AMS. In the case of AMS we use ion-chromatography (IC) for the determination of stable iodine. The IC analysis is included in the separation schemes for environmental materials. First AMS-analyses of terrestrial biospheric materials demonstrate that natural environmental levels of 129I are lower than previously deduced from investigations using RNAA, but higher than expected from model calculations. AMS is capable of providing the missing knowledge about the radioecology of 129I.

Comparison of free-living amoebae in hot water systems of hospitals with isolates from moist sanitary areas by identifying genera and determining temperature tolerance

Legionella-contaminated hot water systems and moist sanitary areas in six hospitals were sampled for amoebae by following a standardized collection protocol. Genus identifications and temperature tolerance determinations were made. Amoebae identified as Hartmannella vermiformis (65%), Echinamoebae spp. (15%), Saccamoebae spp. (12%), and Vahlkampfia spp. (9%) were detected in 29 of 56 (52%) hot water samples. Twenty-three of 49 (47%) swabs obtained from moist areas were amoeba positive. The following genera were identified: Acanthamoeba (22%), Naegleria (22%), Vahlkampfia (20%), Hartmannella (15%), and Vanella (7%). The temperature tolerance of amoebae from hot water systems was strikingly different from that of amoebae from moist areas. At 44 degrees C on agar, 59% of amoebic isolates sampled from hot water systems showed growth. The corresponding value for isolates from moist areas was only 17%. Six Acanthamoeba isolates from the moist areas were considered potential pathogens. Four Hartmannella and two Saccamoeba isolates from hot water could be cultured at 53 degrees C.

Isolation of an Acanthamoeba strain with intracellular Burkholderia pickettii infection

Burkholderia pickettii is a facultative pathogen that has been isolated from patient sources and environmental sources including respiratory therapy solutions, deionized water and aqueous disinfectants. The organism has been associated with septicemia and respiratory tract infections. In our investigation, Burkholderia pickettii (biovar 2) was for the first time isolated from Acanthamoeba sp. (group II), a free living amoeba species recovered from the wet area of a physiotherapy unit. Pathogenic strains of acanthamoebae may cause amoebic-encephalitis (AE) and keratitis. Light and electron microscopic examinations showed that in a first step, the bacterial were phagocytized by the amoebae. In contrast to Enterobacter cloacae and Escherichia coli that were used as food organisms and digested within food vacuoles, Burkholderia pickettii caused the amoebae to develop large vacuoles filled with completely intact and motile bacteria. 3-5 days after infection, Pseudomonas pickettii had multiplied within the enlarging parasitophorous vacuoles. Ultrastructural changes in the host cells occurred and the amoebae finally underwent rupture or lysis. In cocultivation assays we could not only reinfect the original host amoeba but Acanthamoeba strains from other habitats could successfully be infected with Burkholderia pickettii as well.

Obligate intracellular bacterial parasites of acanthamoebae related to Chlamydia spp

The phylogeny of obligate intracellular coccoid parasites of acanthamoebae isolated from the nasal mucosa of humans was analyzed by the rRNA approach. The primary structures of the 16S and 23S rRNA molecules of one strain were determined in almost full length. In situ hybridization with a horseradish peroxidase-labeled oligonucleotide probe targeted to a unique signature site undoubtedly correlated the retrieved 16S rRNA sequence to the respective intracellular parasite. This probe also hybridized with the second strain, suggesting a close relationship between the two intracellular parasites. Comparative sequence analysis demonstrated a distinct relationship to the genus Chlamydia. With 16S rRNA similarities of 86 to 87% to the hitherto-sequenced Chlamydia species, the intracellular parasites are likely not new species of this genus but representatives of another genus in the family of the Chlamydiaceae. Consequently, it is proposed to provisionally classify the endoparasite of Acanthamoeba sp. strain Bn9 as "Candidatus Parachlamydia acanthamoebae." From an epidemiological perspective, the results suggest that small amoebae could be environmental reservoirs and vectors for a variety of potentially pathogenic bacteria including members of the Chlamydiaceae.

Pancreatic lithostathine as a calcite habit modifier

Most biological fluids are supersaturated with calcium salts. A mechanism controlling crystal growth is therefore necessary to prevent excessive precipitation and development of a lithiasis. In pancreatic juice, calcite precipitation is prevented by lithostathine, a glycoprotein that inhibits calcite crystal growth. We describe here the interaction of lithostathine with calcite crystals. Without lithostathine, calcite crystals grew as rhombohedra showing six (104) faces. At low concentration (1 microM), lithostathine already altered crystal growth by generating new (110) faces. At physiological concentrations (3-10 microM), adsorption resulted in a transition from rhombohedral to sub-cubic habits. Immunochemical localization demonstrated that, although all (104) faces are equivalent, lithostathine binding was restricted to the face edges distal to the c axis. Scanning electron microscopy showed that, at the site of lithostathine binding, spreading of new CaCO3 layers during crystal growth was arrested before reaching the crystal diad axis-bearing edges. The successive kinks generated during crystal growth formed the new, striated (110)faces. Similar modifications were observed with the N-terminal undecapeptide of lithostathine that bears the inhibitory activity. With 100 microM lithostathine, (110) faces could reach the c axis outcrop of the former rhombohedron, resulting in an olive-shaped crystal. Finally, the number of crystals increased and their average size decreased when lithostathine concentration increased from 0.1 to 100 microM. Decreased Ca2+ concentration during crystal growth was delayed in the presence of lithostathine. It was concluded that lithostathine controls lithogenesis 1) by triggering germination of numerous calcite crystals and 2) by inhibiting the rate of Ca2+ ion apposition on the nuclei and therefore interfering with the apposition of new layers on calcite. Formation of smaller crystals, whose elimination is easier, is thereby favored.

Biochemical characterization of the 8-hydroxy-5-deazaflavin-reactive hydrogenase from Methanosarcina barkeri Fusaro

The membrane-associated coenzyme F420-reactive hydrogenase of the anaerobic methanogenic archaeon Methanosarcina barkeri Fusaro has been purified 95-fold to apparent homogeneity. A new purification procedure and altered storage conditions gave substantially higher yield (13.4% versus 4.3%) and specific coenzyme F420-reducing activity (82.8 mumol.min-1.mg protein-1 versus 11.5 mumol.min-1.mg protein-1) than reported previously [Fiebig, K. & Friedrich, B. (1989) Eur. J. Biochem. 184, 79-88]. The predominant coenzyme F420-reactive form of the hydrogenase has an apparent molecular mass of 198 kDa and is composed of three non-identical subunits with apparent molecular masses of 48 (alpha), 33 (beta), and 30 kDa (gamma), apparently in a stoichiometry of alpha 2 beta 2 gamma 1. This minimal coenzyme F420-reducing hydrogenase formed aggregates with apparent molecular masses of approximately 845 kDa. 1 mol of the 198-kDa form of hydrogenase contained 2 mol FAD, 2 mol nickel, 28-32 mol non-heme iron, and 34 mol acid-labile sulfur; in addition, 0.2 mol selenium was detected. The isoelectric point was 5.30. The amino acid sequence PXXRXEGH, where X is any amino acid, was found to be conserved in the N-termini of the putative nickel-binding subunits of most [NiFe]- and [NiFeSe]hydrogenases of methanogenic Archaea and Bacteria. However, this motif was not detected in the protein sequences of [Fe]hydrogenases. Maximal coenzyme F420-reducing activity was obtained with reductively reactivated enzyme at 55 degrees C in the pH range 6.5-7.25. The Km values of the purified enzyme for H2 with coenzyme F420 or methylviologen as electron acceptor were extremely low, namely 3 microM and 4 microM. The catalytic efficiency coefficients (kcat/Km) for H2 with both reducible cosubstrates were high: 2.5 x 10(7) M-1.s-1 with coenzyme F420 and 6.9 x 10(7) M-1.s-1 with methylviologen.

The glycan moiety of human pancreatic lithostathine. Structure characterization and possible pathophysiological implications

Lithostathine, also known as pancreatic stone protein, pancreatic thread protein or regenerating protein, is a glycoprotein which is normally found in the exocrine pancreas, whereas in other tissues it appears either only under pathological conditions, such as Alzheimer's disease (brain), cancer (colon) or during regeneration (endocrine pancreas). In the latter case, it has been shown recently that it acts as a growth factor which stimulates islet regeneration. Little is known about its glycan moiety, which conceivably might be involved in this tissue specificity and pathophysiological characteristics. Therefore we isolated the major oligosaccharide chains of human pancreatic lithostathine and determined their sequences by means of NMR analysis. We obtained eleven different glycoforms and we were able to determine the sequence of seven of them. They all were from the same site of glycosylation (Thr5) and displayed the same core 2 structure: GlcNAc(beta 1-6)[Gal(beta 1-3)]GalNAc alpha-. They ranged in size from 4 to 9 sugar residues. Elongation was found to proceed from a common tetrasaccharidic core: Gal(beta 1-4)GlcNAc(beta 1-6)[Gal(beta 1-3)]GalNAc-ol through N-acetyllactosamine units. The non-reducing ends of some oligosaccharides carry the antigenic determinant H, with presence of external Fuc linked only in (alpha 1-2) to Gal. All the glycans, except one, carry a sialic acid in (alpha 2-3) linkage to Gal, with one disialylated form which displays a supplementary (alpha 2-6) linkage. These findings are consistent with the polymorphism of the protein, shown by means of SDS gel electrophoresis and isoelectric focusing, either in its native form or after enzymic processing. Moreover, sialylation seems to protect to some extent the Arg11-Ile12 bond from in situ hydrolysis, thus preventing the harmful precipitation of the C-terminal polypeptide in the pancreatic ducts.

Quantification of human lithostathine by high performance liquid chromatography

Pancreatic stones of patients with chronic calcifying pancreatitis (CCP) are mostly made up of CaCO3 crystals. Formation and growth of such crystals is inhibited in vitro by lithostathine, a protein present in normal pancreatic juice. Decreased lithostathine activity was therefore suspected in patients with CCP, but comparison by immunoassay of lithostathine concentrations in the pancreatic juices of patients and controls led to conflicting results. This study shows that these discrepancies might have been caused in part by a remarkably high susceptibility of the protein to trypsin like cleavage, resulting in important structural changes and concomitant modifications of the epitopes. A novel lithostathine assay in juice was developed, based on separation of secretory proteins by high performance liquid chromatography. The chromatographic separation of lithostathine was based on hydrophobic interactions at pH 5.0 using a Phenyl-TSK column. This study showed with this assay that lithostathine concentrations (microgram/mg of total protein) were similar in CCP patients with alcoholic aetiology (mean (SD) 6.3 (2.7)) and other aetiologies (7.2 (3.7)), but one third of those estimated in patients without pancreatic disease (16.7 (4.3)). Similar concentrations were found, however, in chronic alcoholic patients without CCP (6.6 (3.3)) and in patients with CCP. It was concluded that decreased lithostathine concentration is associated with CCP, although such a decrease is not sufficient by itself for the disease to occur.

[Acanthamoeba, naturally intracellularly infected with Pseudomonas aeruginosa, after their isolation from a microbiologically contaminated drinking water system in a hospital]

The drinking water system of a new hospital building that was highly contaminated with bacteria before opening was investigated too for the prevalence of small free living amoebae. Germ counts resulted in > 100 CFU/ml in 100% of the cold water samples, that showed also growth of P. aeruginosa, whereas E. coli and coliforme bacteria could not be identified. The investigation of 37 water samples for protozoa revealed growth of small freeliving amoebae in 20 samples (54%) belonging to 10 species of the genus Acanthamoeba, Naegleria, Hartmannella, Echinamoeba among others. In addition 2 Ciliate- and 2 Microflagellate-species could be observed. While all Naegleria strains isolated belonged to the N. gruberi-complex two of 16 Acanthamoeba-isolates proved to be pathogenic for laboratory mice. From 7 watersamples positive with P. aeruginosa 5 Acanthamoeba- and 2 Echinamoeba strains could be isolated which revealed intracellular multiplication of P. aeruginosa. Because of their well known resistances against chlorine, the amoebae and their cysts are considered to be vectors for these intracellular bacteria. A complete sanitation of the incriminated drinking water system was accomplished by combined chemical and thermic disinfection measures.

Changes of concentrations of the elements Co, Cr, Sb, and Sc in tissues of persons with joint implants

Elevated levels of Co and Cr were found in several organs of decreased implant bearers (CoCr-alloy/polyethylene joint prostheses) by means of instrumental and radiochemical neutron activation analysis as compared to normal persons. For comparative purposes, concentrations of the elements Co, Cr, Sb, and Sc were measured in heart, kidney, liver, and spleen of the patients and normal persons. For Cr determination, a new radiochemical separation technique with sufficiently low determination limit was employed. The importance of such investigations for studying possible carcinogenic effects of corrosion products and wear particles of metallic prostheses is mentioned.

Risk factors for low urinary citrate in calcium nephrolithiasis: low vegetable fibre intake and low urine volume to be added to the list

Risk factors for low urinary citrate excretion were assessed in 34 consecutive male recurrent idiopathic calcium stone formers (RCSF) who collected two 24-h urines while on free-choice diet. Overt hypocitraturia (hypo-cit) was defined as UCit x V < 1.70 mmol/day, and 'low' citraturia (low-cit) as UCit x V between 1.70 and 2.11 mmol/day. Twenty-three RCSF had normocitraturia (normo-cit), six low-cit and five hypo-cit. UCit x V positively correlated with urine volume (VOLUME, r = 0.44, P = 0.009), vegetable fibre intake (fibers, r = 0.46, P = 0.009) and GI-alkali absorption (alkali, r = 0.47, P = 0.006), and volume, fibres and alkali tended to be lower among RCSF with low-/hypo-cit. A 3-day NH4Cl loading test (0.95 mEq/kg BW daily in 3 doses) was performed in RCSF as well as in 14 age-matched healthy male controls (C). On a plot of urine pH versus serum bicarbonate, 10 of 11 RCSF with low-/hypo-cit, but only six of 23 with normo-cit (P = 0.0004) fell off the normal range, indicating incomplete RTA. Two or more risk factors simultaneously occurred in only four of 23 RCSF with normo-cit, but in eight of 11 with low-/hypo-cit (P = 0.002). In conclusion, incomplete RTA is the most prevalent risk factor for low-/hypo-cit in RCSF, and decreases in vegetable fibres and urine volume emerge as two new risk factors for low urinary CIT.

Isolation of Ewingella americana from a patient with conjunctivitis

Ewingella americana (family Enterobacteriaceae) was isolated separately from both eyes of a 30-year-old woman. Clinical signs and symptoms included adhesive eyelids, itching and edematous upper and lower lids. Therapy with amoxicillin-clavulanate resulted in the relief of symptoms. Ewingella americana can be isolated worldwide, but seems to be a rare pathogen.

Pancreatic gene expression is altered during acute experimental pancreatitis in the rat

We investigated pancreatic gene expression in the rat in response to taurocholate-induced acute pancreatitis. Concentrations of transcripts encoding pancreatic protein showed noncoordinated alterations. Contents in amylase, trypsinogen I, chymotrypsinogen B, elastase 1, and procarboxypeptidase A mRNAs decreased by greater than 50% during the acute phase (days 0-2), whereas actin and lithostathine mRNAs increased 5 and 0.6 times, respectively, and pancreatitis-associated protein (PAP) mRNA increased greater than 200 times, indicating redirection of the pattern of gene expression. Synthesis of pancreatic proteins was also altered in a noncoordinated manner. During the acute phase, it decreased more for trypsinogen I and chymotrypsinogen B than for amylase and lipase, whereas synthesis of the PAP increased dramatically. For amylase and chymotrypsinogen B, we compared the patterns of changes in mRNA concentrations, rates of synthesis, and pancreatic contents. Changes in enzyme contents and synthetic rates were temporally correlated during the acute phase. On the contrary, changes in mRNA concentrations and enzyme synthesis were not coordinated, suggesting that control of synthesis partly occurred at the posttranscriptional level. It was concluded that induction of pancreatitis is accompanied by transcriptional and posttranscriptional modifications resulting in rapid and massive rearrangement of the pattern of pancreatic protein gene expression.

Species identification and characterization of an Acanthamoeba strain from human cornea

The isoenzyme pattern of an Acanthamoeba, stock H-1, isolated from a patient with keratitis (Krankenhaus Heidberg, Hamburg) was compared with that of two strains of A. quina-A. lugdunensis (302-2, 312-1), two stocks of A. lenticulata (45, 89-1) and one strain of A. rhysodes (302-1). The isolated stock showed glucose-6-phosphate dehydrogenase (G-6-PDH), beta-hydroxybutyric dehydrogenase (beta-HBDH), alcohol dehydrogenase (ADH) and superoxide dismutase (SOD) isoenzyme patterns similar to those of A. quina-A. lugdunensis but their acid phosphatase (AP) patterns differed. Furthermore, cyst morphology showed that the patient-isolated stock belongs to group II of the taxonomic classification of Acanthamoeba. This stock was not thermophilic and exhibited non-pathogenic properties after its intranasal instillation into NMRI mice, whereas it killed BALB/c mice. Immunofluorescent studies revealed the presence of antibodies against Acanthamoeba in the patient's serum. Immunoblotting experiments showed that a 45-kDa protein reacted with this serum. Such an antigen was also detected in A. quina-A. lugdunensis and A. lenticulata. Lectin reactions with Canavalia ensiformis, Ricinus communis-120, Lotus tetragonolobus, Ulex europaeus I, Helix pomatia, Arachis hypogaea, Triticum vulgaris, Glycine maxima, Bauhinia purpurea and Mycoplasma gallisepticum demonstrated that only the A. lenticulata stocks could not be distinguished and that the H-1 stock was more similar to the A. lugdunensis 302-2 strain than to the other acanthamoebae.

Systemic effects of implanted prostheses made of cobalt-chromium alloys

Systemic effects of Co-Cr alloy/polyethylene hip joint prostheses were investigated using instrumental neutron activation to determine the concentrations of up to 16 elements. First, in a prospective study whole blood and serum taken from 10 patients from 1 day before to 90 days after implantation were analyzed. Secondly, in a retrospective study whole blood and serum from 23 patients who had had prostheses in place for up to 18 years were analyzed. For comparison, normal trace element levels in humans were determined by analyzing whole blood and serum from 21 patients. Finally, various tissues and organs from two decreased implant patients were analyzed and compared with normal concentrations obtained from the analysis of five "normal" patients without implants. In agreement with other recent investigations, our analyses of normal serum, whole blood, tissues, and organs show that most previously defined "normal" trace element concentrations were too high, chiefly owing to contamination and insufficient blanks. A detailed discussion shows that for many elements the ranges of normal concentrations have to be revised. This conclusion is of particular importance with respect to the sometimes conflicting earlier reports of systemic effects of metal prostheses. In the work reported here, both the prospective and the retrospective investigations of serum and whole blood showed massive Co enrichments as a consequence of implant corrosion. The data show a wide range of individual burdening, ranging from practically no effect to the most extreme values. The analyses of tissues from the vicinity of the implants in the two deceased implant patients showed strong local effects of Co, Cr, Zr, and Hf, the latter two elements originating from the X-ray contrast media in the bone cement. The analyses of organs revealed significant Co and Cr enrichment in several tissues and organs. Consequently, it can be seen that implant corrosion is not an occurrence of merely local significance, but one that affects the trace element status of the entire organism.

[Degenerative changes in schwannoma (neurilemmoma)]

We report on a 51-year-old male patient showing a slowly growing, pedunculated, hairless tumor on the back of his head. The tumor grew up to the size of 4.2 cm in diameter, before it was removed by surgery. Histological examination revealed the typical picture of an ancient schwannoma (degenerated neurilemmoma). In spite of its highly atypical nuclei, the biological behavior of ancient schwannoma is benign, and it must be differentiated from malignant tumors of the nerve sheath.

[Proliferative myositis]

We report on a 42-year-old woman showing a rapidly growing tumor on her left flank; it was removed by surgery. Histological examination revealed the typical picture of proliferative myositis. Since the clinical symptoms of this disease are nonspecific, the diagnosis always depends on histological evidence. Despite its rapid growth and its cellular pleomorphism, proliferative myositis is a reactive process and has to be differentiated histologically from sarcoma of the soft tissue.

[The significance of amoebae and other protozoa in water conduit systems in dental units]

In a longitudinal study over a period of ten weeks, the water conduit systems of seven dental surgeries with a total of 20 dental units in which legionellae had been detected in an earlier study (3) were investigated as a complement to extended microbiological tests (4) for the occurrence of free-living amebae and other protozoa. In 96% of all water samples, one or several ameba species were detected. These included 14 strains of the genus Naegleria, but no acanthamoebae. The naeglerias isolated were not thermophilic and thus belong to the N. gruberi complex, which does not contain any pathogenic strains. In two water samples, two different species of small freeliving nematodes were demonstrated. The simultaneous investigation of samples from the warm water supply in the individual dental surgeries revealed an ameba contamination in 24.9% of the samples. A nonpathogenic strain of the genus Protacanthamoeba was demonstrated once. The possible role of the trophozoites of various ameba species as hosts for an intracellular proliferation of the legionella strains demonstrated at the same time (cf. 4) is discussed. The occasional protective intracellular inclusion of legionellae in trophozoites of various species and in cysts of acanthamoebae might be an explanation for the resistance of legionellae to disinfection measures which has been repeatedly observed. This observation will have to be taken into consideration in sterilization and disinfection projects.

Influence of experience and visual stimulation in Japanese quail laying site selection under experimental condition

We raised female Japanese quail until their post juvenile moult in "neutral" or simplified environments chosen according to features representative of natural habitats. At laying, we placed female quail individually in a choice situation with regard to environmental patterns. 9fiey took account of the visual factors of. their environment in selecting laying site. We found that female Japanese quail preferred a structured achromatic environment over a uniform achromatic environment. They showed a preference for vertical grey stripes over horizontal stripes and a clear preference for green over ochre. Green vertical and horizontal striping proved highly attractive but there was no preference for one or another. Juvenile experience does not affect laying site selection but it certainly does emphasize preference for green. Individual choice proved to be stable but, on the contrary, we found strong interin dividual variability within each one of the groups. The results taken as a whole are relevant to the choices faced by female quails seeking nest sites in their natural habitat.