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Biomedical subjects

M Wille

Publications and source records attributed to M Wille.

16 recordsLinked to original sources

Standardized white spot syndrome virus (WSSV) inoculation procedures for intramuscular or oral routes.

In the past, strategies to control white spot syndrome virus (WSSV) were mostly tested by infectivity trials in vivo using immersion or per os inoculation of undefined WSSV infectious doses, which complicated comparisons between experiments. In this study, the reproducibility of 3 defined doses (10, 30 and 90 shrimp infectious doses 50% endpoint [SID50]) of WSSV was determined in 3 experiments using intramuscular (i.m.) or oral inoculation in specific pathogen-free (SPF) Litopenaeus vannamei. Reproducibility was determined by the time of onset of disease, cumulative mortality, and median lethal time (LT50). By i.m. route, the 3 doses induced disease between 24 and 36 h post inoculation (hpi). Cumulative mortality was 100% at 84 hpi with doses of 30 and 90 SID50 and 108 hpi with a dose of 10 SID50. The LT50 of the doses 10, 30 and 90 SID50 were 52, 51 and 49 hpi and were not significantly different (p > 0.05). Shrimp orally inoculated with 10, 30 or 90 SID50 developed disease between 24 and 36 hpi. Cumulative mortality was 100% at 108 hpi with doses of 30 and 90 SID50 and 120 hpi with a dose of 10 SID50. The LT50 of 10, 30 and 90 SID50 were 65, 57 and 50 hpi; these were significantly different from each other (p < 0.05). A dose of 30 SID50 was selected as the standard for further WSSV challenges by i.m. or oral routes. These standardized inoculation procedures may be applied to other crustacea and WSSV strains in order to achieve comparable results among experiments.

Administration, Oral↗

[Inner amputation of an upper extremity with impaired cerebral perfusion and lethal outcome].

An inner amputation of the upper extremity is understood to be a rupture of the arm's vascular nerve bundle as well as the shoulder's and scapular's stabilizing muscles and fibrous joints without damage to the dermal soft tissue sheath. This injury is a rare and grave incident which mostly occurs within the scope of a high-energy trauma and in cases of polytraumatized patients in combination with additional life-threatening injuries. In the literature this is referred to by the terms scapulothoracic dissociation (SD) and closed forequarter amputation--the entity of SD was first described by Oreck et al. in 1984. Traction of the upper extremity leads to the rupture of the m. pectoralis major, m. pectoralis minor, the musculi rhomboidei, the m. levator scapulae, the m. latissimus dorsi as well as the m. trapezius. Furthermore the traction causes acromioclavicular or sternoclavicular bursting of the joints or a displaced clavicle fracture. Among the more than 50 cases depicted until now, 94% of the patients exhibit a neurological (plexus) and 80% a vascular lesion, thus corresponding to a genuine inner amputation. The prognosis for this injury is consistently poor: 10% of the patients die, in 52% an nonfunctional extremity remains, and in 21% a untimely amputation has to be performed. The observed complication of cerebral hypoperfusion caused by increasing pressure in the neck compartment, which ultimately leads to the death of the patient, has, as far as we know, not yet been specified and emphasizes the gravity and the magnitude as well as the necessity of rapid diagnosis and appropriate therapy of this infrequent injury.

Adult↗

In vivo titration of white spot syndrome virus (WSSV) in specific pathogen-free Litopenaeus vannamei by intramuscular and oral routes.

White spot syndrome virus (WSSV) is a devastating pathogen in shrimp aquaculture. Standardized challenge procedures using a known amount of infectious virus would assist in evaluating strategies to reduce its impact. In this study, the shrimp infectious dose 50% endpoint (SID50 ml(-1)) of a Thai isolate of WSSV was determined by intramuscular inoculation (i.m.) in 60 and 135 d old specific pathogen-free (SPF) Litopenaeus vannamei using indirect immunofluorescence (IIF) and 1-step polymerase chain reaction (PCR). Also, the lethal dose 50% endpoint (LD50 ml(-1)) was determined from the proportion of dead shrimp. The median virus infection titers in 60 and 135 d old juveniles were 10(6.8) and 10(6.5) SID50 ml(-1), respectively. These titers were not significantly different (p > or = 0.05). The titration of the WSSV stock by oral intubation in 80 d old juveniles resulted in approximately 10-fold reduction in virus titer compared to i.m. inoculation. This lower titer is probably the result of physical and chemical barriers in the digestive tract of shrimp that hinder WSSV infectivity. The titers determined by infection were identical to the titers determined by mortality in all experiments using both i.m. and oral routes at 120 h post inoculation (hpi), indicating that every infected shrimp died. The determination of WSSV titers for dilutions administered by i.m. and oral routes constitutes the first step towards the standardization of challenge procedures to evaluate strategies to reduce WSSV infection.

Animals↗

The attribute rating test for sensory analysis.

This new sensory method evaluates the intensity of an odorant by using a modified "paired-comparison" format. It can be applied to any situation for which the odor-causing agent is known and a purified standard is available. The attribute rating test requires that a standard solution of the odorant be prepared at a concentration that is both readily recognized by most individuals and likely to evoke customer complaints. Within an hour individuals can be trained to compare the odor type and intensity of the standard to water samples, then rate the odor in the sample as "not detected," "less than the standard," "equal to standard," or "greater than the standard." The attribute rating test was successfully used by a full-scale water treatment facility to monitor the intensity of geosmin in the source water and to determine the effectiveness of powdered activated carbon for controlling its earthy-odor in treated water.

Carbon↗

Intrathecal use of ropivacaine: a review.

Spinal anesthesia is a very old and popular anesthetic technique, with a high success rate and a good safety profile. In order to further improve and understand safety issues as well as the clinical use of spinal anesthesia, new local anesthetics and analgesic additives are being investigated for different applications. As practice of medicine focuses increasingly on outpatient care, spinal anesthetics should provide short-acting and adequate anesthesia without compromising early ambulation and discharge from the day surgery unit. A review of the current literature suggests that ropivacaine could have potential in this area.

Amides↗

Paleoenvironmental history of the Popayán area since 27 000 yr BP at Timbio, Southern Colombia.

A pollen record from Timbio, located at an elevation of 1750m on the high plain of Popayán (2 degrees 24'N, 76 degrees 36'W) is presented. This forms the basis for reconstructing the vegetation and climate history for the periods from 27000 to 9200 radiocarbon years before the present (14Cyr BP) and 2100 14Cyr BP to sub-recent. The 5m sediment core has time control based on seven AMS radiocarbon dates. Four pollen assemblage zones (TIM-1 to TIM-4) are recognized. During the period of 27200 to 26000 14Cyr BP, an Andean forest was near the site. The vegetation consisted of forest and open herb-rich vegetation, climatic conditions were moist and temperatures some 6 degrees C lower than compared to those of today. During the period of 26000 to 16000 14Cyr BP forest was less open. The observed succession from a Podocarpus-Weinmannia dominated forest to a Hedyosmum dominated forest, and finally to a forest with Ilex, Myrica and ferns indicates a progressive decrease of temperature during this period, with a maximum temperature depression of ca. 5-7.5 degrees C compared to present-day conditions. During the period of 16000 to 9200 14Cyr BP, temperature decrease is estimated at ca. 7.5 degrees C and the climate was the driest. During the period of 2100 to 600 14C2600m altitude (ca. 8 degrees C) and those at sea-level (2.5-6 degrees C) and supports the observation that glacial lapse rates were higher than in modern times.

Journal Article↗

Ammonia toxicity as a criterion for the evaluation of larval quality in the prawn Macrobrachium rosenbergii.

The feasibility of a short-term ammonia toxicity test as an evaluation criterion for larval quality was assessed in three trials. In each one, Macrobrachium rosenbergii larvae originating from the same spawn were nutritionally differentiated in two groups by feeding them either a nutrient-rich (Artemia nauplii enriched for 24 h with n-3 highly unsaturated fatty acids (HUFA) and ascorbic acid (AA)) or a nutrient-poor diet (Artemia nauplii starved for 24 h). Throughout their development, larvae from both treatments were exposed during 24 h to six concentrations of total ammonia (NH(4)(+)+NH(3)) and a control (no ammonia added). Based on mortality rates, the median lethal concentration for 50% of the population (LC(50)) was estimated. As expected from earlier work, larvae fed the optimal diet presented higher n-3 HUFA and AA contents as well as higher growth and metamorphosis rates. From the moment the effect of diet quality was analytically detectable in the tissues of the larvae, the ammonia test was able to distinguish both groups of larvae. Differences in ammonia tolerance were observed as early as larval stage 4 and remained evident throughout larval development. The short-term ammonia toxicity test proved to be a valuable, sensitive and reproducible criterion for the establishment of larval quality.

Age Factors↗

Fluoride release from a toothbrush.

The purpose of the present study was to evaluate the fluoride concentration in unstimulated saliva after using a toothbrush with 9,048 ppm fluoride as sodium fluoride incorporated in the bristles. A toothpaste with 1,500 ppm fluoride served as the positive control. Twelve volunteers took part in the single-blind crossover study. In a pre-test phase of 14 days, the subjects refrained from eating fluoride-rich foods and did not use any fluoride-containing products for oral hygiene measures. This was followed by a test period of four weeks. At day one and after 14 and 28 days, unstimulated saliva was collected and analyzed for its fluoride content. Saliva was collected immediately after toothbrushing and after 15, 30, 60, 90, 120 150, and 180 minutes. On day one, the fluoride toothbrush released significant amounts of fluoride immediately after the brushing, and after 15 and 30 minutes (p < 0.01). After 14 days of use, this could be found immediately after brushing and after 15 minutes (p < 0.01 or p < 0.05, respectively). After 28 days, a significant fluoride release was only found immediately after brushing (p < 0.05). On all days, compared to the positive control, the fluoride release from the fluoride toothbrush was generally lower immediately after brushing and after 15 minutes (p < 0.001, p < 0.01 or p < 0.05, respectively). It may be concluded that a toothbrush with incorporated sodium fluoride could act as a fluoride-releasing. device.

Cariostatic Agents↗

Gelsolin-actin complex is target for ADP-ribosylation by Clostridium botulinum C2 toxin in intact human neutrophils.

The gelsolin-actin complex was ADP-ribosylated by Clostridium botulinum C2 toxin and Clostridium perfringens iota toxin in lysates of human platelets and human neutrophils. When [32P]orthophosphate-labelled human neutrophils were treated with C. botulinum C2 toxin, [32P]ADP-ribosylated gelsolin-actin was precipitated with anti-gelsolin antibody. Stimulation of neutrophils by formyl-methionine-leucine-phenylalanine decreased the interaction of gelsolin with ADP-ribosylated actin in toxin-treated cells. The data indicate that the gelsolin-actin complex is a pathophysiological substrate for actin-ADP-ribosylating toxins.

Actins↗

ADP-ribosylation of gelsolin-actin complexes by clostridial toxins.

ADP-ribosylation of the 1:1 (G-A) and 1:2 (G-A-A) gelsolin-actin complexes by Clostridium perfringens iota toxin and Clostridium botulinum C2 toxin was studied. Iota toxin ADP-ribosylated actin in the G-A complex from human platelets as effectively as skeletal muscle actin. The Km for NAD (4 microM) was identical for both substrates. C2 toxin ADP-ribosylated actin in the G-A complex with lower efficacy than nonmuscle actin from platelet cytosol. In the G-A-A complex both actin molecules were ADP-ribosylated by iota toxin. The G-A complex bound ADP-ribosylated actin (Ar) to form the G-A-Ar complex in which the weakly bound actin is ADP-ribosylated. Vice versa, ADP-ribosylated 1:1 gelsolin-actin complex (G-Ar) was able to bind unmodified actin to yield the G-Ar-A complex. ADP-ribosylation did not change the nucleation activity of either the G-Ar complex or the G-Ar-A complex. When monomeric actin was added to the G-A-Ar complex, polymerization of actin was delayed by about 10 min. According to a quantitative kinetic analysis, the delay of polymerization corresponded to the rate of dissociation of ADP-ribosylated actin from the G-A-Ar complex. This suggests that the nucleation activity of the G-A-A complex is inhibited by ADP-ribosylation of the weakly bound actin and that the inhibition can be removed by dissociation of ADP-ribosylated actin from the G-A-Ar complex.

ADP Ribose Transferases↗

The complete sequence of botulinum neurotoxin type A and comparison with other clostridial neurotoxins.

The seven serologically different botulinum neurotoxins are highly potent protein toxins that inhibit neurotransmitter release from peripheral cholinergic synapses. The activated toxins consist of the toxifying A-subunits (Mr approximately 50,000) linked by a disulfide bond to the receptor-binding BC-subunits (Mr approximately 100,000). We have established the complete sequence of botulinum neurotoxin type A (BoNT/A; 1,296 amino acid residues, Mr = 149,425) and a partial sequence of botulinum neurotoxin type E (273 amino acid residues) as deduced from the corresponding nucleotide sequences of the chromosomally located structural genes. The promoter of the BoNT/A gene is inactive in Escherichia coli. Primer extension experiments indicated that initiation of transcription of the BoNT/A gene occurred 118 nucleotides upstream from the ATG codon. A comparison of the protein sequence revealed an overall identity of 33.8% to that of tetanus toxin. No significant similarity to other known proteins including ADP-ribosylating toxins could be detected. Three of the six histidine residues of the A-subunit of BoNT/A were found in the peptide sequence H223ELIHXXH230 within a domain of predicted alpha-helical secondary structure. This motif is also found in similar positions of the A-subunits of tetanus toxin and BoNT/E.

Amino Acid Sequence↗

Characterization of the ADP-ribosylation of actin by Clostridium botulinum C2 toxin and Clostridium perfringens iota toxin.

Clostridium botulinum C2 toxin and Clostridium perfringens iota toxin belong to a novel family of actin ADP-ribosylating toxins. ADP-ribosylation of actin inhibits actin polymerization and G-actin-associated ATPase activity. The ADP-form of actin is ADP-ribosylated at a higher rate than actin with bound ATP. ADP-ribosylation of actin is reversible, a reaction, which is accompanied by reconstitution of actin ATPase activity.

Actins↗

[The strength of retinal sear tissue after argon-, xenon-, and cryocoagulation (author's transl)].

A method is presented for measuring the adhesive force between retina and pigment epithelium in rabbit eye preparations. This force shows a great interindividual variation and so the absolute value is of little interest. The variation of several readings in one animal is, however, significantly smaller. Therefore the relative change in adhesive force between untreated and treated areas of one animal can be used. The data shows similar increases of +25-30%. For laser-, xenon-, and cryocoagulation, the maximum adhesive strength is reached within 4-8 days after treatment. After a few weeks the additional adhesion in treated areas slowly fell to about +10% as compared to pretreatment levels.

Adhesiveness↗