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PubMed1986

Chromosome damage induced by herpes simplex virus type 1 in early infection.

The chromosome damage induced by herpes simplex virus type 1 (HSV-1) in vitro was examined up to 6 h after infection using HT-1080 cells. Initial damage occurring within 3 h was specific, involving uncoiling of chromosome 1q12-21 and to a lesser extent the pericentric regions of chromosomes 9, 16 and satellited chromosomes. For the initial unwinding, synthesis of the immediate early class of HSV proteins needed to occur as was demonstrated using HSV-1 temperature-sensitive mutants tsK and tsB7 and two viral inhibitors, beta-propiolactone and psoralen plus long wavelength u.v. light. Later damage included chromatid breaks, acentric fragments and pulverization which did not take place until synthesis of delayed early proteins had begun.

Cell Line↗
PubMed2004

Log-stable laws as asymptotic solutions to a fragmentation equation: application to the distribution of droplets in a high Weber-number spray.

In this paper, it will be shown that "totally skewed to the left" log-stable distributions are suitable asymptotic solutions to a fragmentation equation. This result generalizes Kolmogorov's work on log-normal distribution for the drops' size number distribution of particles under pulverization. Indeed, Kolmogorov's discrete process is extended to a continuous time Markov process for the volume distribution instead of the number distribution. New hypotheses are then introduced which lead to log-stable distributions as asymptotic solutions of the fragmentation equation. Log-stable laws are then used to fit experimental probability distribution function (pdf) of Simmons and Hanratty measuring drop sizes in a horizontal annular gas-liquid flow at high Weber number [Int. J. Multiphase Flow 27, 861 (2001)]]. Log-stable pdf better fits to the experimental pdf than usual empirical spray pdf and especially, because of the heavy tail of the associated stable distribution, in the small drops part of the distribution.

Journal Article↗
PubMed1996

Rapid [gamma]-Aminobutyric Acid Synthesis and the Inhibition of the Growth and Development of Oblique-Banded Leaf-Roller Larvae.

The hypothesis that rapid [gamma]-aminobutyrate (GABA) accumulation is a plant defense against phytophagous insects was investigated. Increasing GABA levels in a synthetic diet from 1.6 to 2.6 [mu]mol g-1 fresh weight reduced the growth rates, developmental rates, and survival rates of cultured Choristoneura rosaceana cv Harris larvae. Simulation of the mechanical damage resulting from phytophagous activity increased soybean (Glycine max L.) leaf GABA 10- to 25-fold within 1 to 4 min. Pulverizing leaf tissue resulted in a value of 2.15 ([plus or minus]0.11 SE) [mu]mol GABA g-1 fresh weight.

Journal Article↗
PubMed1981

Immunological approach to structural comparisons of assimilatory nitrate reductases.

Homogeneous squash cotyledon reduced nicotinamide-adenine dinucleotide (NADH):nitrate reductase (NR) was isolated using blue-Sepharose and polyacrylamide gel electrophoresis. Gel slices containing NR were pulverized and injected into a previously unimmunized rabbit. This process was repeated weekly and antiserum to NR was obtained after four weeks. Analysis of the antiserum by Ouchterlony double diffusion using a blue-Sepharose preparation of NR resulted in a single precipitin band while immunoelectrophoresis revealed two minor contaminants. The antiserum was found to inhibit the NR reaction and the partial reactions to different degrees. When the NADH:NR and the reduced methyl viologen:NR activities were inhibited 90% by specifically diluted antiserum, the reduction of cytochrome c was inhibited 50%, and the reduction of ferricyanide was inhibited only 30%. Antiserum was also used to compare the cross reactivities of NR from squash cotyledons, spinach, corn, and soybean leaves, Chlorella vulgaris, and Neurospora crassa. These tests revealed a high degree of similarity between NADH:NR from the squash and spinach, while NADH:NR from corn and soybean and the NAD(P)H:NR from soybean were less closely related to the squash NADH:NR. The green algal (C. vulgaris) NADH:NR and the fungal (N. crassa) NADPH:NR were very low in cross reactivity and are apparently quite different from squash NADH:NR in antigenicity. Antiserum to N. crassa NADPH:NR failed to give a positive Ouchterlony result with higher plant or C. vulgaris NADH:NR, but this antiserum did inhibit the activity of squash NR. Thus, it can be concluded from these immunological comparisons that all seven forms of assimilatory NR studied here have antigenic determinants in common and are probably derived from a common ancestor. Although these assimilatory NR have similar catalytic characteristics, they appear to have diverged to a great degree in their structural features.

Journal Article↗
PubMed1999

A method to produce microseed stock for use in the crystallization of biological macromolecules.

A method is presented for producing a seed-stock mixture for macromolecular crystallization. A PTFE bead and micro-centrifuge tube act as mortar and pestle for pulverizing seed crystals of macromolecules. Energy for the bead's motion is supplied by a vortex mixer or an ultrasonic bath. The crushed crystal is serially diluted to prepare a seed-stock mixture of the desired concentration for crystallization. Crystals produced using both hanging-drop vapor diffusion and a capillary microbatch method show expected dilution behavior. This technique of producing seed stock is compared with traditional means and advantages over the standard protocol are demonstrated.

Biochemistry↗
PubMed1992

Phage pattern and antibiotic resistance pattern of coagulase-negative staphylococci obtained from immunocompromised patients.

A total of 152 coagulase-negative staphylococcal strains were isolated from clinical samples of 14 patients hospitalized after bone-marrow transplantation in a specialized hospital ward in Hungary, during an 18-month period between 1987 and 1989. Two species, Staphylococcus epidermidis and Staphylococcus haemolyticus, predominated (each, 45%). Using Pulverer and co-workers' phage set for typing, 68% of the isolates were typable; 16 phage patterns were observed. A characteristic long pattern with phages Ph10/Ph13/Ph15/U4/U15/U16/U20/U33 /U46 appeared only in S. epidermidis, among 5 of 11 colonized patients (8.5% of all strains). Single lysis with phage Ph13 was observed in 7 of the 14 patients (49% of all strains), in species S. capitis, S. epidermidis, S. haemolyticus, S. hominis, and S. warneri. In S. haemolyticus, non-typable strains predominated (66%); this character occurred only in 2% among other species. The strains colonizing the immunocompromised patients differed from each other in phage pattern, antibiotic resistance pattern, and/or slime production. No hospital infection was suggested. On the other hand, high incidence of two well-definable phage patterns raises some relationship between phage receptors or some regulatory systems in phage multiplication and factors responsible for special colonization as common surface properties.

Bacterial Typing Techniques↗
PubMed2005

Ovipositional site selection by Anopheles gambiae: influences of substrate moisture and texture.

The influence of substrate moisture (hydration) and grain size (texture) on oviposition was quantified in choice tests using Anopheles gambiae sensu stricto Giles (Diptera: Culicidae) laboratory strains and gravid An. gambiae sensu lato from a natural population in Western Kenya. A strong, positive correlation was found between moisture content and the degree of egg-laying, which peaked at saturation with standing water. Soil moisture quantified as surface conductivity, was measured with an electronic leaf-wetness sensor slightly modified from a unit available commercially. Although An. gambiae females were sensitive to measurable differences in substrate moisture, they distributed eggs on both fully hydrated and less hydrated substrates. In contrast, An. gambiae females showed little response to substrate texture: they oviposited with equal frequency on all silica substrates of eight particle size classes, ranging from small pebbles (850 microm diameter) to very fine grains (< 38 microm diameter), when all were moist. Female An. gambiae laid more eggs on dark than white substrates against a light background, but did not discriminate between moist, pulverized black soapstone and moist black Kenyan soil taken from typical An. gambiae larval habitats. We conclude that hydration and visual contrast are critical ovipositional site qualities for An. gambiae, but substrate texture is not.

Animals↗
PubMed1989

Immunochemical estimations of allergenic activities from outdoor aero-allergens, collected by a high-volume air sampler.

To quantify airborne allergens in amorphus and morphological particles, a survey with collection of aero-allergens on glass fibre filters by means of a high-volume air-sampler (HIVOL) was conducted. In preliminary laboratory experiments we compared various filter elution techniques, and the pulverizing elution technique was found to be optimal with regard to yield and convenience. When a surfactant, Tween 20 (0.5% v/v), was added to the elution buffer, a recovery of 80% could be obtained. Allergens in eluates were analysed by means of an IgG-subclass RAST inhibition assay. This immunochemical method for quantification of airborne allergens was validated, as a high recovery of timothy grass pollen allergens was eluted from air filters, and eluates were shown specific by RAST inhibition. The amount of immunochemically measured airborne timothy and birch allergens collected by means of the HIVOL sampler was highly correlated with pollen counts obtained with a Burkard sampler (pollen trap) situated in the same place.

Air Pollutants↗
PubMedDate not supplied

Sonographic patterns of radiolucent gall-bladder stones for predicting successful shock-wave lithotripsy.

The aim of this study was to examine whether the sonographic patterns of gallstones are useful for predicting the outcome of piezoelectric shock-wave lithotripsy. Pretreatment analysis of gallstones based on our sonographic classification was conducted on 115 patients with radiolucent solitary stones of 10-30 mm in diameter, monitored for at least a year after the first lithotripsy. All stones were categorized as type I with gradual attenuation of echoes: type Ia, the stone echo appears as a full moon, usually accompanied by comet-tail artifacts beyond the stone itself (n = 55); type Ib, the stone echo showing the anterior half of the stone, seen as a half moon (n = 29); and type Ic, the stone echo seen as a crescent (n = 31). The most complete fragmentation, 'pulverization', was achieved at a significantly higher rate for type Ia (51%) than for type Ib (14%, P < 0.005) and type Ic (7%, P < 0.0001) after significantly fewer shock-waves (vs type Ib, P < 0.01; vs type Ic, P < 0.0001). The rate of complete clearance at 12 months after lithotripsy was significantly greater for type Ia (91%) than for type Ib (62%, P < 0.01) and type Ic (45%, P < 0.0001). Comparison of the sonographic and computed tomography (CT) patterns of stones revealed a close relationship between the two: the vast majority (98%) of type Ia showed the iso- or hypo-dense, and the majority (90%) of type Ic the rimmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholelithiasis↗
PubMed1996

Detection of Proteus mirabilis urease gene in urinary calculi by polymerase chain reaction.

BACKGROUND: Urea-splitting microorganisms cannot always be detected by stone or urine culture in patients with infection stones. Detection of genetic elements within the calculi by the polymerase chain reaction (PCR) may be a useful alternative. In this study, we assessed the usefulness of the PCR method in detecting the urease gene specific to Proteus mirabilis in urinary calculi. METHODS: Thirty-eight metabolic stones (calcium oxalate and/or calcium phosphate, uric acid, or cystine) and 49 struvite stones were examined. The PCR was applied with DNA extracted by boiling pulverized stone pieces. RESULTS: Of the 87 stones, PCR demonstrated the presence of the P. mirabilis urease elements ureC1 and ureC2 in 17, all of which were struvite. Stone culture and urine culture had been performed in 22 and 46 struvite stone cases, respectively, and the PCR was positive in all of the 10 culture-positive calculi and also in two calculi from which P. mirabilis was not isolated. CONCLUSION: PCR was reliable and convenient for detecting P. mirabilis in desiccated struvite calculi. Study to detect other species such as Ureaplasma or Corynebacterium would be useful in elucidating the role of bacterial infection in the formation of these stones.

Adult↗
PubMed2006

Role of uric acid in different types of calcium oxalate renal calculi.

AIM: The presence of uric acid in the beginning zone of different types of 'pure' calcium oxalate renal calculi was evaluated with the aim of establishing the degree of participation of uric acid crystals in the formation of such calculi. METHODS: The core or fragment of different types of 'pure' calcium oxalate renal calculi was detached, pulverized and uric acid extracted. Uric acid was determined using a high-performance liquid chromatography/mass spectrometry method. RESULTS: In calcium oxalate monohydrate (COM) papillary calculi with a core constituted by COM crystals and organic matter, 0.030+/-0.007% uric acid was found in the core. In COM papillary calculi with a core constituted by hydroxyapatite, 0.031+/-0.008% uric acid was found in the core. In COM unattached calculi (formed in renal cavities) with the core mainly formed by COM crystals and organic matter, 0.24+/-0.09% uric acid was found in the core. In COM unattached calculi with the core formed by uric acid identifiable by scanning electron microscopy (SEM) coupled to X-ray microanalysis, 20.8+/-7.8% uric acid was found in the core. In calcium oxalate dihydrate (COD) unattached calculi containing little amounts of organic matter, 0.012+/-0.004% uric acid was found. In COD unattached calculi containing little amounts of organic matter and hydroxyapatite, 0.0030+/-0.0004% of uric acid was found. CONCLUSIONS: From these results it can be deduced that uric acid can play an important role as inducer (heterogeneous nucleant) of COM unattached calculi with the core formed by uric acid identifiable by SEM coupled to X-ray microanalysis (these calculi constitute the 1.2% of all calculi) and in COM unattached calculi with the core mainly formed by COM crystals and organic matter (these calculi constitute the 10.8% of all calculi).

Calcium Oxalate↗
PubMed1983

Methylation of mercury from dental amalgam and mercuric chloride by oral streptococci in vitro.

The capacity of the oral bacteria Streptococcus mitior, S. mutans and S. sanguis to methylate mercury was investigated in vitro. Mercuric chloride and pulverized dental amalgam in distilled water, respectively, were used as sources of mercury. Methylmercury was found in the bacterial cells of all three tested strains. The results indicate that organic mercury compounds may be formed in the oral cavity.

Dental Amalgam↗
PubMed1992

Primate dentine extracellular matrix induces bone differentiation in heterotopic sites of the baboon (Papio ursinus).

In rodents, demineralized dentine matrix induces local differentiation of endochondral bone. This study investigated the osteoinductive potential of primate dentine matrices when implanted extraskeletally in allogeneic recipients. Demineralized dentine cylinders prepared from adult baboon incisors and demineralized dentine matrix pulverized to a particle size of 74-420 microns were implanted into the rectus abdominis of 4 subadult male baboons (Papio ursinus). Specimens were harvested 30 and 90 d after implantation. Histological analysis on serial sections showed bone differentiation in demineralized dentine cylinders after partial resorption of the external demineralized layer, and in resorption lacunae and excavation chambers within the matrix. Implants of demineralized dentine matrix of 74-420 microns particle size showed no osteoinductive activity as determined biochemically (alkaline phosphatase activity) and histologically. The demonstration of bone induction by primate dentine prepared from fully erupted tooth matrix suggests that putative osteogenic proteins may be conserved after dentinogenesis and embryonic tooth development, and may play a role during healing after surface demineralization of exposed root surfaces during regenerative procedures in humans.

Animals↗
PubMed1994

Detection and quantification of melatonin in a dinoflagellate, Gonyaulax polyedra: solutions to the problem of methoxyindole destruction in non-vertebrate material.

Preservative procedures are described for the extraction and quantification of melatonin in cell material from the dinoflagellate Gonyaulax polyedra, an organism in which this indoleamine is rapidly degraded due to interaction with free oxygen radicals and photooxidation. Cells were shock-frozen in liquid nitrogen and pulverized. Various extraction methods were applied to the powder, and rates of recovery were compared. For the determination of melatonin by high performance liquid chromatography (HPLC), extractions with acetone or perchloric acid were more suitable than the use of other solvents. For purposes of radioimmunoassay (RIA), extraction with acetone gave the best results. Several other inorganic solvents, which are often applied in melatonin research, such as chloroform, dichloromethane, and diethyl ether, led to considerable losses of the indoleamine. The procedures developed for HPLC with either electrochemical or fluorescence detection also allow the quantification of other indolic compounds, in particular, tryptophan and 5-methoxytryptamine. The methods described may be of value in the further search for melatonin and related indoleamines in non-vertebrate material, especially, from unicells, multicellular plants, and invertebrates.

Animals↗
PubMed1987

Regulation of serum sodium in dehydrated and orally rehydrated infants. Influence of age and of purging rates.

We have examined the control of serum sodium concentration (S-Na) in 60 male infants with acute diarrheal disease, moderate dehydration, but without the presence of fever, vomiting or other conditions. The infants were studied on admission and during oral rehydration therapy (ORT). We examined the effect of rapid reduction of the purging rate on the control of S-Na by adding pulverized rice and pulses (dal moong) to the rehydration solution. On admission S-Na was significantly inversely related to age. This correlation could not only be attributed to difference in stool sodium losses. Changes in S-Na and urinary K/Na ratio during oral rehydration therapy (ORT), were analyzed separately in infants below and above 4 month of age. During the first six hours of ORT, there was an increase in S-Na in all groups. During the following 18 hours, S-Na tended to normalize around 138 mmol/l. Normalization occurred faster if purging rate was reduced. In all groups urinary K/Na ratio (index of aldosterone production and, inversely, of sodium balance), was high at admission and fell during ORT. In the youngest infants (below 4 month of age) the fall was significantly more pronounced if the purging was reduced. We conclude that it is important to consider age when prescribing ORT. The capacity to correct disturbances in S-Na becomes more efficient during maintenance stage of ORT. Correction of S-Na and sodium balance is enhanced by rapid reduction of abnormal intestinal losses.

Acute Disease↗
PubMed2006

Massive strontium ferrite ingestion without acute toxicity.

Ingestion of strontium ferrite is previously unreported. We document absorption of strontium without acute toxicity. A 22 year-old schizophrenic man was brought to hospital after he was witnessed to pulverize and ingest flexible adhesive magnets, which later were identified as strontium ferrite. Other than auditory hallucinations his vital signs, physical examination, ECG and routine laboratories were unremarkable. Abdominal radiographs revealed diffuse radiopaque material. He was treated with whole bowel irrigation with polyethylene glycol electrolyte lavage solution (PEG-ELS) until radiographically cleared. His initial blood and urine strontium levels were 2900 microg/l and 15,000 microg/l, respectively (reference range for urine: <240 microg/l, occupational threshold 800 microg/l). A repeat urine level one week later was 370 microg/l. His hospital course was complicated by bacteraemia secondary to a thrombophlebitis at the site of the intravenous catheter, and the patient was treated with intravenous and oral antibiotics. He remained otherwise asymptomatic and was discharged to a psychiatric unit approximately 3 weeks later. Although clearly absorbed, strontium ferrite does not appear to produce acute toxicity. Delayed, and or chronic toxicity cannot be excluded based on this report.

Adult↗
PubMed1994

Bioextraction (reductive dissolution) of iron from low-grade iron ores. Fundamental and applied studies.

Results of the present study indicate that S. putrefaciens 200 may be a suitable Fe(3+)-reducing microorganism for commercial application in a microbially catalyzed iron ore bioextraction (reductive dissolution) process. The proposed scheme of the bioextraction process (Fig. 1) entails the addition of a suitable iron ore to anaerobic, batch cultures of aerobically grown S. putrefaciens 200, with subsequent recovery of Fe2+ in the product stream. Although batch growth under low oxygen tension is known to induce expression of the high-rate Fe3+ reduction system in S. putrefaciens, such growth conditions do not appreciably enhance the rate at which S. putrefaciens catalyzes the reductive dissolution of iron from low-grade iron ore. As a result, strict monitoring of dissolved oxygen levels during batch growth is not required. Highly aerobic growth conditions are most desirable because such conditions maximize microbial growth rates. Commercial application of the proposed process is made more attractive by the ability to grow S. putrefaciens aerobically on a relatively inexpensive organic substrate (filter-sterilized, primary effluent wastewater) as sole carbon and energy source. Physical and chemical factors that accelerate overall reductive dissolution rates include (i) pulverization of the iron ores before their addition to the anaerobic, batch cultures, and (ii) subsequent addition of an Fe(III)-chelating agent to the anaerobic iron ore-microorganism slurry. Recycle of residual ore remaining in the initial reactor vessel after a one-hour incubation is recommended, since overall reductive dissolution rates decrease dramatically after that time. Significant enhancement of the overall reductive dissolution rates may reside in the ability to genetically engineer a more robust Fe(3+)-reducing microorganism. Preliminary genetic studies presented here indicate that S. putrefaciens is a suitable model microorganism for studying the molecular basis of microbial Fe3+ reduction. Mutagenesis experiments demonstrated that the Fe3+ reduction system of S. putrefaciens is physiologically uncoupled from other electron-accepting processes carried out by this bacterium, and that a distinct ferrireductase enzyme is expressed after growth under either highly aerobic or microaerobic conditions. An array of S. putrefaciens mutants (Class I), deficient only in their ability to grow anaerobically on Fe3+ as sole terminal electron acceptor, were isolated and a single mutant selected for subsequent gene cloning (complementation) experiments. Restriction enzyme analysis of putative, complemented clones (i.e., transconjugates in which the ability to grow anaerobically on Fe3+ had been restored) revealed the presence of a common cloned DNA insert.(ABSTRACT TRUNCATED AT 400 WORDS)

Biotechnology↗
PubMed1994

Modeling the Dornier HM3 lithotripter.

The computational modeling of a Dornier HM3 electrohydraulic, extracorporeal shock wave lithotripter is considered. In order to produce large amplitude shock waves for the purpose of pulverizing renal and ureteric calculi (stones), the HM3 uses a hemi-ellipsoidal bowl to focus the spherical field generated by a high-voltage spark gap. The initial propagation of the bowl-focused field is accomplished using a recently developed nonplanar source algorithm. An updated version of an existing nonlinear acoustic beam propagation model is then used to consider the subsequent propagation of the field. The resulting modeling sequence accounts for the effects of diffraction, attenuation, dispersion, nonlinearity, and (planar) reflection and refraction. The water path computed predictions agree well with existing measurements. The computed in vivo predictions suggest that the Dornier HM3's clinical performance is not significantly different than its water path performance.

Equipment Design↗