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At least 667 records · Page 37Linked to original sources
PubMed1988

Dorsal root entry zone lesions for conus medullaris root avulsions.

We have found dorsal root entry zone (DREZ) lesions to be an effective treatment of chronic deafferentation pain in patients who have had avulsions of the dorsal rootlets from the spinal cord. Eight patients were operated in whom chronic pain of the lower extremity resulted from dorsal root avulsions from the conus medullaris. In 7 of the 8 patients, the mechanism of injury was a motor vehicle accident; all 7 sustained severe pelvic trauma. Seven of the 8 patients remained pain-free, off all narcotics, with an average follow-up of 33 months. All patients had DREZ lesions of the conus performed by radiofrequency techniques.

Adult↗
PubMed1996

Human root caries: microbiota of a limited number of root caries lesions.

The microbiota of root caries lesions of different grades of severity were studied. Fourteen lesions were examined. The experimental design of the study allowed correlation of histopathologically distinguishable stages with specific and distinct microbial populations. Dentin samples were ground in a sterile mortar and cultured anaerobically on nonselective Columbia blood agar plates supplemented with 5% hemolyzed human blood and on media selective for Lactobacillus spp. and streptococci. The cultivable microbiota were quantitatively speciated using Rapid ID 32A, Rapid ID 32 Strep, API 20 Strep, APIZYM, and API50 CH tests and SDS-PAG electrophoresis. In initial as well as in advanced lesions gram-positive bacteria accounted for approximately 90% of the CFUt. The proportion of Actinomyces, and in particular A. naeslundii was significantly higher (p < 0.05) in initial lesions than in advanced lesions. In contrast, the percentage of Streptococcus and especially S. mutans was higher (p < 0.05) in advanced than in initial lesions. Surprisingly low (0.8% of the CFUt) was the percentage of lactobacilli in advanced lesions. Gram-negative bacteria formed a minor part of the microbiota in both initial and advanced lesions. Among the gram-negative isolates, Prevotella, Selenomonas, and Bacteroides spp. were most noticeable. In advanced lesions, only the outermost layer of 0.5 mm thickness was populated by a high number of bacteria; the following segments harbored a negligible number of bacteria only. It is concluded that root caries is a continuous destruction process which is restricted to a subsurface zone of limited depth. The necrotic dentin is successively worn away, leading to a saucer-shaped cavitation which is repopulated by plaque. The creation of cavitations favors an aciduric flora. This might explain the succession of bacterial populations observed during the destruction process.

Actinomyces↗
PubMed2004

Antifungal compounds from the root and root exudate of Zea mays.

A maize plant (Zea mays) planted in a test tube was found to inhibit the growth of the soil-borne plant pathogen, Fusarium oxysporum f. sp. melongenae. The antifungal compounds, 6-methoxybenzoxazolinone and 6,7-dimethoxybenzoxazolinone, were isolated from an ethanol extract of Zea mays roots, and (6R)-7,8-dihydro-3-oxo-alpha-ionone and (6R,9R)-7,8-dihydro-3-oxo-alpha-ionol were isolated from the root exudate.

Antifungal Agents↗
PubMed2001

Utilization of different carbon sources by bacteria isolated from the roots of pine seedlings (Pinus silvestris L.) inoculated with root-free, rhizosphere and mycorrhizosphere soil.

Studies were carried out on the utilization of different sugars (glucose, fructose, arabinose, xylose, sucrose) and organic acids (acetic, citric, fumaric, propionic, succinic) by fast and slow growing bacteria isolated from the roots of pine seedlings (P. silvestris L.) inoculated with root-free, rhizosphere and mycorrhizosphere soil from nursery and mature pine forest. Sucrose among sugars and propionic acid among organic acids were the less frequently utilized compounds. Sugars were better carbon sources than organic acids. Proportion of isolates utilizing respective sugars or organic acids was, in general, significantly higher among fast growing bacteria as compared with slow growing ones. No significant differences in number of strains assimilating the appropiate sugars depending on their original habitat or kind of soil were observed. Such differences were noted for utilization of some organic acids. 3-factor ANOVA confirmed that the growth speed of bacteria at the moment of their isolation had the strongest effect on utilization of the compounds studied.

Bacteria↗
PubMed2002

[Limit of root canal obturation by gutta percha compaction technique in single rooted teeth. Clinical data apropos of 168 canals].

After the introduction of the lateral compactage of gutta percha in endodontic clinic of OdontoStomatology Institute of Dakar in 1995; the immediate evaluation of the quality and the limit of the canal obturation due to a prospective study on 157 monoradicular teeth so be 168 canals (11 supplementary canals) has shown that 75% of canals are of type I of Vertucci and that the apical limit of security is reached within 80.25% of cases. The manual step back canal preparation (79.17%) and the technique of canal obturation by lateral compactage of gutta percha [(64.88%); Apical limit of security: 59.52%] permit to obtain a densities (95.83%) and homogeneous (79.57%) canal obturation. The indication of gutta percha compactage on monoradicular teeth (hermetic and tridimensional root canal filling) must avail to apical curved roots of lateral incisive, the use of adapted instruments in case of canines (31 mm) and apical stop cone on necrotic pulp teeth.

Adult↗
PubMed2002

Number of root canals, their shape, configuration, accessory root canals in radicular pulp morphology. A preliminary study.

Dental Pulp is a soft gelatinous, living cellular tissue of ectomesenchymal origin having various functions, residing within bilayered hard mineralized structures like enamel, dentin and cementum. Hertwigs epithelial root sheath initiates the formation of size, shape and number of radicular pulp. Deciduous pulp cavities differ from permanent teeth present study was conducted to find out number of root canals and their pattern, in deciduous teeth.

Dental Pulp Cavity↗
PubMed2006

Root canal transportation with a Ni-Ti rotary file system and stainless steel hand files in simulated root canals.

OBJECTIVE: The purpose of this study was to compare the root canal transportation of the crown-down technique performed with the Ni-Ti rotary ProFile system (Dentsply/Maillefer), with the step-back technique using stainless steel K-Flexofiles (Dentsply/Maillefer). METHOD AND MATERIALS: Thirty simulated root canals in resin blocks were equally divided into 2 groups. The first group was instrumented with the ProFile system in a crown-down technique and the second group with hand K-Flexofiles in a step-back technique. After instrumentation, resin blocks of both groups were scanned by a transparency scanner, and the derived images were superimposed with the scanned image of an uninstrumented block. Transportation was digitally calculated by a computer software, and results were statistically evaluated by Student t test. RESULTS: Statistically significant differences (P < .05) were found among the 2 groups at 1, 2, 4, 5, and 6 mm from the apical foramen. No statistically significant difference was detected at 3 mm from the apical foramen. CONCLUSION: ProFile caused less transportation at 1 and 2 mm from the apex, whereas at 3 mm, both instrumentation techniques caused the same transportation. Standard deviation was less in the ProFile group than in the hand file group, indicating a more standardized preparation.

Dental Alloys↗
PubMedDate not supplied

[The dimensions of the roots and root canals of human premolars and molars].

Dental roots and channels were measured in 160 premolars and molars on human upper and lower jaws. The longest roots were found in 5-th teeth and shortest in 7-th. The data suggest that dental channels can be extended up to 10 mm. Their maximal widening in upper jaw molars and premolars is 1 mm and in lower premolars 1.2 mm.

Bicuspid↗
PubMed1979

[Root canal filling materials (electron scanning microscope comparison of root canal adaptation to 3 endodontic filling products)].

The main characteristics required of a good endodontic fillingsmaterial are its perfectly hermetic sealing of the root canal, the eventual secondary canals, and the dentine canals, against bacteria. 48 root canals, sealed respectively with A H 26, Endomethazone and N 2, have been checked by means of the Scanning Electron Microscope in order to discover to what extent these products conform to the qualifications mentioned. 842 photographs have been taken. The results of the investigation are discussed judging from some photographs chosen at random.

Dental Pulp Cavity↗
PubMedDate not supplied

Intra-alveolar transplantation of deeply fractured roots after elongation with titanium roots screws.

Teeth with deep transverse or oblique fractures have posed severe challenges for treatment in the past. Today, such teeth can be saved by transplantation within the alveolus. In this pilot study, a technique is described by means of which roots otherwise determined to be too short can be salvaged. Fourteen fractured short roots were extracted carefully, elongated with titanium screws, and subsequently replanted.

Adult↗
PubMed1997

[Sacral nerve root cysts. Discussion on the mechanism of nerve root suffering. Apropos of 4 cases].

Low back pain, sciatia or perineal chronic pain are sometimes related to perineural sacral cysts. Surgical treatment is difficult and may lead to pain or neurological worsening. We report four cases of symptomatic perineural cysts; three of them where operated on with two good results and one increasing perineal pain. Anatomical and radiological description are reviewed. From a therapeutical point of view, we can distinguish two clinical types of radicular suffering. Perineural cyst can cause a commun radicular extrinsic compression; in such a case surgical operation will improve radicular pain. The cystic nerve root can present an intrinsic suffering because of on intradural dilaceration. Then surgery must be avoided specially when many roots are involved because it may worsen the pluriradicular suffering.

Adult↗
PubMed2006

Effect of root canal treatments on quartz fiber posts bonding to root dentin.

The aim of this study was to evaluate the effect of irrigants and endodontic sealers on fiber post push-out strength in both fatigue cycling and no-cycling conditions. Fifty single-rooted human teeth received five endodontic treatments. The posts were cemented using a flowable composite and a three-steps adhesive. Five specimens from each group were subjected to 2 x 10(6) cycles of 37.5 N. There were 200 sections obtained for the push-out test. Fatigue cycled groups treated with an eugenol-containing sealer showed the lowest push-out strength (p < 0.001). No significant differences were found among no-cycled groups (p = 0.665). The post-cement interface was found to be weaker than the cement-dentin one. However, fatigue cycles increased the occurrence of cement-dentin failures (p = 0.001). The eugenol-containing sealer reduced the bonding of fiber posts when mechanically cycled, thus the use of a resin-based sealer is advisable.

Chelating Agents↗
PubMed1996

Isolation of cDNAs encoding two purine biosynthetic enzymes of soybean and expression of the corresponding transcripts in roots and root nodules.

Soybean nodule cDNA clones encoding glycinamide ribonucleotide (GAR) synthetase (GMpurD) and GAR transformylase (GMpurN) were isolated by complementation of corresponding Escherichia coli mutants. GAR synthetase and GAR transformylase catalyse the second and the third steps in the de novo purine biosynthesis pathway, respectively. One class of GAR synthetase and three classes of GAR transformylase cDNA clones were identified. Northern blot analysis clearly shows that these purine biosynthetic genes are highly expressed in young and mature nodules but weakly expressed in roots and leaves. Expression levels of GMpurD and GMpurN mRNAs were not enhanced when ammonia was provided to non-nodulated roots.

Acyltransferases↗
PubMed1994

Isolation of chalcone synthase and chalcone isomerase cDNAs from alfalfa (Medicago sativa L.): highest transcript levels occur in young roots and root tips.

Flavonoids are involved in several different interactions between plants and microorganisms. In the Rhizobium-legume symbiosis, they play an important role as inducers of rhizobial nodulation (nod) genes. We have identified from an alfalfa cDNA library four clones for chalcone synthase (CHS) and two clones for chalcone isomerase (CHI); CHS and CHI are key enzymes in flavonoid biosynthesis. In Medicago sp., CHS is encoded by 8-12 genes, and CHI is encoded by 1-2 genes. Here we report the DNA sequence of these clones as well as their relatedness to other legume CHS and CHI clones. In addition, we report on the expression patterns of two CHS gene family members as well as the CHI gene in M. sativa cv. Iroquois. While CHS and CHI transcript levels are high in root tips and entire young roots, they are low in effective nodules elicited by wild-type strains of Rhizobium meliloti and very low in aerial portions of the plant (stems, leaves, flowers). However, wounding the cotyledons results in a rapid increase in transcript levels of both chalcone synthase and chalcone isomerase genes in these organs.

Acyltransferases↗
PubMed1981

Depression of ventral root--dorsal root potential by DL-alpha-aminoadipate in frog spinal cord.

Ventral root--dorsal root potential (VR--DRP) was partially depressed in the presence of 1 mM DL-alpha-aminoadipate (DL-alpha-AAD), probably corresponding to 0.5 mM D-alpha-AAD, in isolated hemisected frog spinal cord. It was suggested that acidic amino acid receptors might be subserving for the generation of VR--DRP in addition to the initial cholinergic link between motoneurons and interneurons and the electrical coupling between motoneurons and primary afferent terminals and the last step between unidentified interneurons and primary afferent terminals which had been reported to be mediated by GABA.

2-Aminoadipic Acid↗
PubMed1991

The effect of bicuculline and baclofen on the dorsal root-ventral root reflex in the isolated spinal cord.

1. In the lumbar spinal cord, 10(-6) M bicuculline reduces the inhibition of the dorsal root-ventral root (DR-VR) reflex produced by lateral stimulation of the spinal cord. The inhibition returns on washing in control artificial cerebrospinal fluid (ACSF). 2. Baclofen (10(-6) M) inhibits the monosynaptic DR-VR reflex which returns on washing in control ACSF. 3. This suggests an involvement of GABAA receptors in the lateral inhibition and GABAB receptors in the DR-VR reflex system. 4. The increased activity seen following bicuculline or tubocurarine probably resets the "set point" of neural activity to a lower level.

Action Potentials↗
PubMed2006

Effects of electro-acupuncture on the expression of c-jun and c-fos in spared dorsal root ganglion and associated spinal laminae following removal of adjacent dorsal root ganglia in cats.

This study evaluated the plastic changes of c-jun and c-fos in the right sixth lumbar dorsal root ganglion (L6 DRG), Rexed's lamina II in representative spinal segments L3, L5, and L6 and in the nucleus dorsalis (ND) at L3 segments after electro-acupuncture (EA) in cats subjected to removal of L1-L5 and L7-S2 DRG. Following dorsal root ganglionectomy, there was a significant increase in the density of c-jun immunoreactivity in the neurons and glia in spinal lamina II and in the ND; there was also marked elevation in the expression of c-fos in ND. In both cases there was no change in the c-jun and c-fos immunoreactivity in the DRG. After EA in the operated animals, there was an up-regulation in the expression of c-jun in the L6 DRG and the associated spinal lamina II; however, increased c-fos expression was detected only in the L6 DRG. Western blot and RT-PCR were also performed to quantitatively explore the mRNA and protein expression changes in the spinal dorsal horn and associated DRG. Following partial deafferentation, there was a significant increase in the protein level of both c-jun and c-fos in the dorsal horn, while, in both cases there was no change in c-jun and c-fos protein and mRNA in the DRG. After EA in the operated animals, both c-jun protein and its mRNA in the L6 DRG as well as the associated dorsal horn of L6 spinal segment were upregulated, but increased c-fos protein and its mRNA was observed only in the L6 DRG. These findings suggested that c-jun and c-fos might be related to the acupuncture promoted spinal cord plasticity as reported previously.

Animals↗