Cerebral Microbleeds May Be Less Detectable by Susceptibility Weighted Imaging MRI From 24 to 72 Hours After Traumatic Brain Injury

Purpose: A former rodent study showed that cerebral traumatic microbleeds (TMBs) may temporarily become invisible shortly after injury when detected by susceptibility weighted imaging (SWI). The present study aims to validate this phenomenon in human SWI.

Methods: In this retrospective study, 46 traumatic brain injury (TBI) patients in various forms of severity were included and willingly complied with our strict selection criteria. Clinical parameters potentially affecting TMB count, Rotterdam and Marshall CT score, Mayo Clinic Classification, contusion number, and total volume were registered. The precise time between trauma and MRI [5 h 19 min to 141 h 54 min, including SWI and fluid-attenuated inversion recovery (FLAIR)] was individually recorded; TMB and FLAIR lesion counts were assessed. Four groups were created based on elapsed time between the trauma and MRI: 0–24, 24–48, 48–72, and >72 h. Kruskal–Wallis, ANOVA, Chi-square, and Fisher’s exact tests were used to reveal differences among the groups within clinical and imaging parameters; statistical power was calculated retrospectively for each comparison.

Results: The Kruskal–Wallis ANOVA with Conover post hoc analysis showed significant (p = 0.01; 1−β > 0.9) median TMB number differences in the subacute period: 0–24 h = 4.00 (n = 11); 24–48 h = 1 (n = 14); 48–72 h = 1 (n = 11); and 72 h ≤ 7.5 (n = 10). Neither clinical parameters nor FLAIR lesions depicted significant differences among the groups.

Conclusion: Our results demonstrate that TMBs on SWI MRI may temporarily become less detectable at 24–72 h following TBI.

Microbleeds show a characteristic distribution in cerebral fat embolism

This systematic review aims to test the hypothesis that microbleeds detected by MRI are common and show a characteristic pattern in cerebral fat embolism (CFE). Eighty-four papers involving 140 CFE patients were eligible for this review based on a systematic literature search up to 31 January 2020. An additional case was added from hospital records. Patient data were individually scrutinised to extract epidemiological, clinical and imaging variables. Characteristic CFE microbleed pattern resembling a "walnut kernel" was defined as punctuate hypointensities of monotonous size, diffusely located in the subcortical white matter, the internal capsule and the corpus callosum, with mostly spared corona radiata and non-subcortical centrum semiovale, detected by susceptibility- or T2* weighted imaging. The presence rate of this pattern and other, previously described MRI markers of CFE such as the starfield pattern and further diffusion abnormalities were recorded and statistically compared. The presence rate of microbleeds of any pattern, the "walnut kernel microbleed pattern", diffusion abnormality of any pattern, the starfield pattern, and cytotoxic edema in the corpus callosum was found to be 98.11%, 89.74%, 97.64%, 68.5%, and 77.27% respectively. The presence rate between the walnut kernel and the starfield pattern was significantly (p < 0.05) different. Microbleeds are common and mostly occur in a characteristic pattern resembling a "walnut kernel" in the CFE MRI literature. Microbleeds of this pattern in SWI or T2* MRI, along with the starfield pattern in diffusion imaging appear to be the most important imaging markers of CFE and may aid the diagnosis in clinically equivocal cases.

Taxamat: Automated biodiversity data management tool - Implications for microbiome studies

Working with biodiversity data is a computationally intensive process. Numerous applications and services provide options to deal with sequencing and taxonomy data. Professional statistics software are also available to analyze these type of data. However, in-between the two processes there is a huge need to curate biodiversity sample files. Curation involves creating summed abundance values for chosen taxonomy ranks, excluding certain taxa from analysis, and finally merging and downsampling data files. Very few tools, if any, offer a solution to this problem, thus we present Taxamat, a simple data management application that allows for curation of biodiversity data files before they can be imported to other statistics software. Taxamat is a downloadable application for automated curation of biodiversity data featuring taxonomic classification, taxon filtering, sample merging, and downsampling. Input and output files are compatible with most widely used programs. Taxamat is available on the web at http://www.taxamat.com either as a single executable or as an installable package for Microsoft Windows platforms.

Cerebral Microbleeds Temporarily Become Less Visible or Invisible in Acute Susceptibility Weighted Magnetic Resonance Imaging: A Rat Study

Previously, we reported human traumatic brain injury cases demonstrating acute to subacute microbleed appearance changes in susceptibility-weighted imaging (SWI—magnetic resonance imaging [MRI]). This study aims to confirm and characterize such temporal microbleed appearance alterations in an experimental model. To elicit microbleed formation, brains of male Sprague Dawley rats were pierced in a depth of 4 mm, in a parasagittal position bilaterally using 159 μm and 474 μm needles, without the injection of autologous blood or any agent. Rats underwent 4.7 T MRI immediately, then at multiple time points until 125 h. Volumes of hypointensities consistent with microbleeds in SWI were measured using an intensity threshold-based approach. Microbleed volumes across time points were compared using repeated measures analysis of variance. Microbleeds were assessed by Prussian blue histology at different time points. Hypointensity volumes referring to microbleeds were significantly decreased (corrected p < 0.05) at 24 h compared with the immediate or the 125 h time points. By visual inspection, microbleeds were similarly detectable at the immediate and 125 h imaging but were decreased in extent or completely absent at 24 h or 48 h. Histology confirmed the presence of microbleeds at all time points and in all animals. This study confirmed a general temporary reduction in visibility of microbleeds in the acute phase in SWI. Such short-term appearance dynamics of microbleeds should be considered when using SWI as a diagnostic tool for microbleeds in traumatic brain injury and various diseases.

Multi-aspect candidates for repositioning: data fusion methods using heterogeneous information sources

Drug repositioning, an innovative therapeutic application of an old drug, has received much attention as a particularly costeffective strategy in drug R&D Recent work has indicated that repositioning can be promoted by utilizing a wide range of information sources, including medicinal chemical, target, mechanism, main and side-effect-related information, and also bibliometric and taxonomical fingerprints, signatures and knowledge bases. This article describes the adaptation of a conceptually novel, more efficient approach for the identification of new possible therapeutic applications of approved drugs and drug candidates, based on a kernel-based data fusion method. This strategy includes (1) the potentially multiple representation of information sources, (2) the automated weighting and statistically optimal combination of information sources, and (3) the automated weighting of parts of the query compounds. The performance was systematically evaluated by using Anatomical Therapeutic Chemical Classification System classes in a cross-validation framework. The results confirmed that kernel-based data fusion can integrate heterogeneous information sources significantly better than standard rank-based fusion can, and this method provides a unique solution for repositioning; it can also be utilized for de novo drug discovery. The advantages of kernel-based data fusion are illustrated with examples and open problems that are particularly relevant for pharmaceutical applications.

First occurrence of periosteal chondroma (juxtacortical chondroma) in Uromastyxmaliensis (Reptilia: Sauria: Agamidae)

The occurrence of a periosteal chondroma (juxtacortical chondroma) in an adult male Uromastyx maliensis is documented for the first time. The chondroma developed near the right shoulder joint from the periosteal membrane, causing partial atrophy in the surrounding skeletal muscles. In the chondroma tissues widespread central necrosis and secondary calcium salt deposition were observed. Monomorphic chondrocytes were irregularly spread in the chondromucin matrix. The lizard had locomotor problems due to irritation of the periosteum and reduced movement of the bones constituting the shoulder joint caused by the chondroma.

Factors affecting survival of bacteriophage on tomato leaf surfaces

The ability of bacteriophage to persist in the phyllosphere for extended periods is limited by many factors, including sunlight irradiation, especially in the UV zone, temperature, desiccation, and exposure to copper bactericides. The effects of these factors on persistence of phage and formulated phage (phage mixed with skim milk) were evaluated. In field studies, copper caused significant phage reduction if applied on the day of phage application but not if applied 4 or 7 days in advance. Sunlight UV was evaluated for detrimental effects on phage survival on tomato foliage in the field. Phage was applied in the early morning, midmorning, early afternoon, and late evening, while UVA plus UVB irradiation and phage populations were monitored. The intensity of UV irradiation positively correlated with phage population decline. The protective formulation reduced the UV effect. In order to demonstrate direct effects of UV, phage suspensions were exposed to UV irradiation and assayed for effectiveness against bacterial spot of tomato. UV significantly reduced phage ability to control bacterial spot. Ambient temperature had a pronounced effect on nonformulated phage but not on formulated phages. The effects of desiccation and fluorescent light illumination on phage were investigated. Desiccation caused a significant but only slight reduction in phage populations after 60 days, whereas fluorescent light eliminated phages within 2 weeks. The protective formulation eliminated the reduction caused by both of these factors. Phage persistence was dramatically affected by UV, while the other factors had less pronounced effects. Formulated phage reduced deleterious effects of the studied environmental factors.

Bacteriophages for plant disease control

The use of phages for disease control is a fast expanding area of plant protection with great potential to replace the chemical control measures now prevalent. Phages can be used effectively as part of integrated disease management strategies. The relative ease of preparing phage treatments and low cost of production of these agents make them good candidates for widespread use in developing countries as well. However, the efficacy of phages, as is true of many biological control agents, depends greatly on prevailing environmental factors as well as on susceptibility of the target organism. Great care is necessary during development, production and application of phage treatments. In addition, constant monitoring for the emergence of resistant bacterial strains is essential. Phage-based disease control management is a dynamic process with a need for continuous adjustment of the phage preparation in order to effectively fight potentially adapting pathogenic bacteria.

Integration of Biological Control Agents and Systemic Acquired Resistance Inducers Against Bacterial Spot on Tomato

Two strains of plant growth-promoting rhizobacteria, two systemic acquired resistance inducers (harpin and acibenzolar-S-methyl), host-specific unformulated bacteriophages, and two antagonistic bacteria were evaluated for control of tomato bacterial spot incited by Xanthomonas campestris pv. vesicatoria in greenhouse experiments. Untreated plants and plants treated with copper hydroxide were used as controls. The plant growth-promoting rhizobacteria or a tap water control were applied as a drench to the potting mix containing the seedlings, while the other treatments were applied to the foliage using a handheld sprayer. The plant growth-promoting rhizobacteria strains, when applied alone or in combination with other treatments, had no significant effect on bacterial spot intensity. Messenger and the antagonistic bacterial strains, when applied alone, had negligible effects on disease intensity. Unformulated phage or copper bactericide applications were inconsistent in performance under greenhouse conditions against bacterial spot. Although acibenzolar-S-methyl completely prevented occurrence of typical symptoms of the disease, necrotic spots typical of a hypersensitive reaction (HR) were observed on plants treated with acibenzolar-S-methyl alone. Electrolyte leakage and population dynamics experiments confirmed that acibenzolar-S-methyl-treated plants responded to inoculation by eliciting an HR. Application of bacteriophages in combination with acibenzolar-S-methyl suppressed a visible HR and provided excellent disease control. Although we were unable to quantify populations of the bacterium on the leaf surface, indirectly we determined that bacteriophages specific to the target bacterium reduced populations of a tomato race 3 strain of the pathogen on the leaf surface of acibenzolar-S-methyl-treated plants to levels that did not induce a visible HR. Integrated use of acibenzolar-S-methyl and phages may complement each other as an alternative management strategy against bacterial spot on tomato.

Management of Tomato Bacterial Spot in the Field by Foliar Applications of Bacteriophages and SAR Inducers

Various combinations of the harpin protein, acibenzolar-S-methyl, and bacteriophages were compared for controlling tomato bacterial spot in field experiments. Harpin protein and aciben-zolar-S-methyl were applied every 14 days beginning twice before transplanting and then an additional four applications throughout the season. Formulated bacteriophages were applied prior to inoculation followed by twice a week at dusk. A standard bactericide treatment, consisting of copper hydroxide plus mancozeb, was applied once prior to inoculation and then every 7 days, while untreated plants served as an untreated control. Experiments were conducted in north and central Florida fields during fall 2001, spring 2002, and fall 2002. In three consecutive seasons, acibenzolar-S-methyl applied in combination with bacteriophage or bacteriophage and harpin significantly reduced bacterial spot compared with the other treatments. However, it did not significantly affect the total yield compared with the standard or untreated control. Application of host-specific bacteriophages was effective against the bacterial spot pathogen in all three experiments, providing better disease control than copper-mancozeb or untreated control. When results of the disease severity assessments or harvested yield from the bacteriophage-treated plots were grouped and compared with the results of the corresponding nonbacteriophage group, the former provided significantly better disease control and yield of total marketable fruit.

Improved Efficacy of Newly Formulated Bacteriophages for Management of Bacterial Spot on Tomato

Bacteriophages are currently used as an alternative method for controlling bacterial spot disease on tomato incited by Xanthomonas campestris pv. vesicatoria. However, the efficacy of phage is greatly reduced due to its short residual activity on plant foliage. Three formulations that significantly increased phage longevity on the plant surface were tested in field and greenhouse trials: (i) PCF, 0.5% pregelatinized corn flour (PCF) + 0.5% sucrose; (ii) Casecrete, 0.5% Casecrete NH-400 + 0.5% sucrose + 0.25% PCF; and (iii) skim milk, 0.75% powdered skim milk + 0.5% sucrose. In greenhouse experiments, the nonformulated, PCF-, Casecrete-, and skim milk-formulated phage mixtures reduced disease severity on plants compared with the control by 1, 30, 51, and 62%, respectively. In three consecutive field trials, nonformulated phage caused 15, 20, and 9% reduction in disease on treated plants compared with untreated control plants, whereas plants treated with PCF- and Casecrete-formulated phage had 27, 32, and 12% and 30, 43, and 24% disease reduction, respectively. Plants receiving copper-mancozeb treatments were included in two field trials and had a 20% decrease in disease in the first trial and a 13% increase in the second one. Skim milk-formulated phage was tested only once and caused an 18% disease reduction. PCF-formulated phage was more effective when applied in the evening than in the morning, reducing disease on plants by 27 and 13%, respectively. The Casecrete-formulated phage populations were over 1,000-fold higher than the nonformulated phage populations 36 h after phage application.

Increasing the injection volume by dilution improves the onset of motor blockade, but not sensory blockade of ropivacaine for brachial plexus block

BACKGROUND AND OBJECTIVE

Ropivacaine used for axillary plexus block provides effective motor and sensory blockade. Varying clinical dosage recommendations exist. Increasing the dosage by increasing the concentration showed no improvement in onset. We compared the behaviour of a constant dose of ropivacaine 150 mg diluted in a 30, 40 or 60 mL injection volume for axillary (brachial) plexus block.

METHODS

A prospective, randomized, observer-blinded study on patients undergoing elective hand surgery was conducted in a community hospital. Three groups of patients with a constant dose of ropivacaine 150 mg, diluted in 30,40 or 60 mL NaCl 0.9%, for axillary plexus blockade were compared for onset times of motor and sensory block onset by assessing muscle strength, two-point discrimination and constant-touch sensation.

RESULTS

Increasing the injection volume of ropivacaine 150 mg to 60 mL led to a faster onset of motor block, but not of sensory block, in axillary plexus block, compared with 30 or 40 mL volumes of injection.

CONCLUSIONS

The data show that the onset of motor, but not of sensory block, is accelerated by increasing the injection volume to 60 mL using ropivacaine 150 mg for axillary plexus block. This may be useful for a more rapid determination of whether the brachial plexus block is effective. However, when performing surgery in the area of the block, sensory block onset seems more important.

[Periarterial sympathectomy of the radial and ulnar arteries in Raynaud's phenomenon--a preliminary study]

PURPOSE

Assessment of the post-operative results of peripheral sympathectomy in Raynaud's phenomenon.

METHODS

Six patients with therapy refractory Raynaud's phenomenon underwent a 4 cm long adventitial stripping of the radial and ulnar arteries proximal to the wrist. The nerve of Henle was followed up to the surface of the palmar arch and resected. The pre- and postoperative examinations were performed using the help of a questionnaire, telethermography and infra-red laser reflexion rheography.

RESULTS

All but two patients (two hands) were free of complaints (four patients, six hands), the three ulcers on the finger tips healed well. According to the questionnaire there was a dramatic improvement in the quality of life of the patients.

CONCLUSION

In the follow-up period of two years, there was no recurrence. Adventitial stripping of the radial and ulnar arteries and resection of the nerve of Henle proximal to the wrist have demonstrated favourable results in the treatment of therapy-resistant complaints in Raynaud's phenomenon.

[The sympathetic axons of the nerves of the hand]

PURPOSE

In the hand surgery literature, more and more studies seem to indicate that the number of sympathetic fibers in the median and the ulnar nerves varies. However, there are no studies that confirm this suspicion.

METHOD AND MATERIAL

Six hours post mortem samples were taken from the median and ulnar nerves, the superficial branch of the radial nerve, and from all digital nerves (each five females and males, average age 78 years). 13 samples were taken from one hand. To make sympathetic fibers visible, the immunohistochemical staining technique with tyrosinhydroxylase (TH) antibodies was used. Quantitative assessment of the sympathetic axons was made in whole cross-sections of the nerve. Statistical evaluation was performed with Wilcoxon rank-sum tests.

RESULTS

The TH-positive axons are arranged in groups and are located in the endoneurium. No isolated sympathetic fibers were found in the peri- and epineurium. TH-positive axons were present on the arterial walls including the smallest arterioles. Proximal to the wrist, the median nerve has more sympathetic fibers than the ulnar nerve. The number, however, of the fibers was the same in each fascicle. A comparison of the digital nerves shows significant differences only between the radial nerve of the thumb and the ulnar nerve of the ring finger and between the radial nerve of the index finger and the ulnar nerve of the little finger.

CONCLUSION

Although the median nerve proximal to the wrist has on average 20 fascicles and the ulnar nerve only 14, the number of fibres in each fascicle is the same. Therefore, based on the present study we conclude that there is no significant difference in the sympathetic fiber distribution of the two nerves.

Functional impairment of the abdominal wall following laparoscopic and open cholecystectomy

BACKGROUND

Subcostal incisions for open cholecystectomy (OC) denervate the right upper and middle abdomen.

METHODS

Sensory and abdominal muscle function (Janda's muscle function test, Cybex 6000) was evaluated. Healthy volunteers (10 women, 12 men) were compared with 13 women and 12 men after OC and 11 women and 11 men after laparoscopic cholecystectomy (LC). For computed tomography (CT) studies, a spiral scanner was used.

RESULTS

Of the OC patients, 21 (95.5%) complained of dys- and anesthesias below the incision. Of the LC patients, only nine (2.4%) reported anesthesias around the port sites. Normal subjects scored significantly higher in muscle strength (p <.01). LC patients scored higher than OC patients at 10 degrees and 20 degrees trunk flexion (p <.05). Depending on the flexion angles, the men in all groups developed 30-114% more muscle power than the women. Denervation of the abdominal muscles was confirmed by CT.

CONCLUSION

OC reduced skin sensitivity and abdominal muscle function. Although the procedure is minimally invasive, LC also causes sensory and functional losses, albeit minor ones.

[Proximal neuropathy of the median nerve]

In a 77 year old man the rare clinical picture of a complete lesion of the median nerve at the upper arm is described. During removal of a "neurinoma" at the upper arm, inadvertedly the general surgeon had also transsected the median nerve. However diagnosis was delayed due to electrodiagnostic tests, which erronously interpreted the volume conduction of the neigbouring nerves as partial function, and later even as improvement of the median nerve function. Clinically he presented with "orators" hand. He was unable to pinch thumb and index finger, Sensory loss was noted at the fingertip 2 and 3, atrophy of the abductor pollicis brevis muscle and trophic skin changes with an ulcer at the tip of the index finger. Nerve revision confirmed the median nerve transsection. Intraoperative nerve stimulation could not elicit distal muscle stimulation. Sural nerve transplant was performed and within one year a positive Tinel sign progressing 20 cm distally to the operation site, without distal motor or sensory changes was observed.

The nerve of Henle: an anatomic and immunohistochemical study

The topography of the nerve of Henle was reviewed. Fifty-two human cadaveric upper extremities were studied. In 30 (58%) the nerve was well defined; in 22 (42%) its origin from the ulnar nerve was unidentifiable. The palmar cutaneous branch of the ulnar nerve separated from the ulnar nerve 5 to 11 cm distal to the medial epicondyle of the humerus to divide into its terminal branches in the distal forearm. Four patterns were detected: ulnar, radioulnar, vessel-related, and radial. These shared a consistent vascular branch, which sent 2 branches to the ulnar artery just proximal to the distal ulnar tunnel. Using a tyrosine hydroxylase antibody-based immunohistochemistry technique the nerve was shown to carry sympathetic fibers. Motor fibers were ruled out with Karnovsky's stain, which was used in combination with the tyrosine hydroxylase method in 10 specimens.

[Bursitis calcarea--an often overlooked and falsely diagnosed illness of the hand]

OBJECTIVE

To compare surgical and conservative management in patients with acute calcific bursitis of the hand, a rare condition often misdiagnosed because of its unspecific symptoms.

METHOD

Four patients with calcific bursitis at the metacarpophalangeal or distal interphalangeal joints or the pisiform are presented. Of these, 3 underwent surgery, while one was treated conservatively. Clinical and radiological symptoms and signs are described.

RESULTS

The 3 patients treated surgically returned to work on the 10th postoperative day, while the patient who refused surgery needed rehabilitation for 4 weeks.

CONCLUSION

Surgery to remove the calcium deposits enables patients to resume work earlier than after conservative treatment which may take weeks.