Plasminogen activator in periodontal health and disease.
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Adult↗
Biomedical subjects
J Schmid
Publications and source records attributed to J Schmid.
The excitation site of the trigeminal nerve to transcranial magnetic stimulation varies and lies proximal or distal to the foramen ovale: an intraoperative electrophysiological study in man.
The excitation site of the trigeminal nerve using transcranial magnetic stimulation (magStim) was analyzed in 5 patients in whom the trigeminal nerve was surgically exposed in the posterior fossa during microvascular decompression of the facial nerve for hemifacial spasm. The trigeminal nerve was stimulated (1) magnetically immediately prior to craniotomy, and (2) electrically near the root exit zone (elREZ) of the nerve from the brainstem. Mean latency differences (delta) of masseter compound muscle action potentials (CMAPs) (delta elREZ minus magStim) were 0.7 (range: +0.3 to +1.3) ms (P less than or equal to 0.05, Wilcoxon-test). From these results, an analysis of anatomical data, and using a trigeminal nerve conduction velocity (NCV) of 50 m/s as reported in the literature, the following conclusions were drawn: the excitation site to magStim (1) is variable among individuals, (2) is located 3.4 (1.6-6.5) cm distal to the trigeminal REZ, and (3) which corresponds to segments of the nerve that are located either within or outside the cerebrospinal fluid (CSF), either proximal or distal to the foramen ovale. These findings are in contrast to those we obtained in a previous study of the facial nerve in which the excitation site was found to be constant among subjects and restricted to the location on the nerve where it exists the high conductivity CSF to enter the high-resistance petrous bone.
Action Potentials↗
Transcranial magnetic stimulation of the facial nerve: intraoperative study on the effect of stimulus parameters on the excitation site in man.
Magnetic stimulation (magStim) of the intracranial facial nerve is performed in clinical and research settings, but the activation site is a matter of controversy. Latencies of nasalis muscle responses to magStim were, therefore, compared with those obtained by direct electrical stimulation of the facial nerve (a) at the root exit zone (REZ); (b) at the porus of the facial canal; and (c) in the stylomastoid fossa during microvascular decompression operations in the cerebellopontine angle (CPA). Measurements of latencies of the nasalis muscle response, obtained while the stimulating coil was placed over the parieto-occipital area of the scalp, indicated that it was the labryinthine segment of the facial canal, 5 to 16 mm distal to the CPA, that was activated. This would be in agreement with studies of physical models reported in the literature that showed (a) the strength of the electrical current generated by a magnetic field is particularly high close to a nerve foramen; and (b) excitation to magStim is most likely to occur where the induced electrical field changes rapidly over distance, i.e., at anatomical boundaries between media of high and low specific resistance. These characteristics are found at the end of the labyrinthine segment of the facial canal, where the facial nerve leaves the low-resistance cerebrospinal fluid and enters the high-resistance petrous bone. The site of neural excitation is robust and unaffected by stimulus intensity and current direction within a wide range, or by large changes in location of the coil.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Osseous healing of experimentally created defects in the calvaria of rabbits using guided bone regeneration. A pilot study.
The aim of this study was to test whether healing of extensive transosseous defects in the calvaria can successfully be achieved using guided bone regeneration. The results demonstrated complete osseous bridging of the skull defect in the test specimen. In the control specimen, fibrous connective tissue occupied the area of the skull defect.
Animals↗
Genetic similarity and maintenance of Candida albicans strains from a group of AIDS patients, demonstrated by DNA fingerprinting.
By using the computer-assisted Dendron system to analyze the patterns of Southern blots probed with the repetitive sequence Ca3, we have compared oral isolates of Candida spp. from a group of 11 nonhospitalized patients with AIDS suffering from recurrent episodes of oral thrush in Leicester, England, with oral isolates from a group of control individuals. Genetic diversity among the AIDS strains was significantly reduced compared with that of control strains. In addition, the same strains persisted through recurrent infections in patients with AIDS. Although AIDS strains were genetically less diverse than either control strains or oral commensal strains analyzed in previous studies, the majority did not form a genetically distinct group. The results of this study suggest that in the majority of patients with AIDS in this group from Leicester, original commensal strains were replaced, replacement occurred early in the manifestation of AIDS, and replacement occurred only once.
Acquired Immunodeficiency Syndrome↗
Motor and somatosensory evoked potentials in coma: analysis and relation to clinical status and outcome.
Central sensory and motor conduction were studied in 23 comatose and three brain-dead patients. Motor evoked potentials (MEPs) to transcranial magnetic (magMEP) and electrical (elMEP) stimulation were recorded from the hypothenar muscle, and somatosensory evoked potentials (SEPs) were recorded after median nerve stimulation. Comparison of clinical with evoked potential (EP) findings revealed: 1) a painful stimulus applied to the skin of the arm lowered excitation threshold to cortical stimulation and was a prerequisite to obtain MEPs in 14 instances; 2) only in braindead patients were all EPs abolished simultaneously and bilaterally; 3) MEPs (p less than or equal to 0.05, chi 2-Test), but not necessarily SEPs (p greater than 0.1) were preserved in the arms that showed normal motor reaction during clinical examination; 4) no correlation was found between EP findings and the Glasgow Coma Scale (GCS). The results of clinical and EP testing were examined in the light of the patient's outcome 10 months later: 1) fatal outcome was predicted by a GCS of three (38% of cases, p less than or equal to 0.05, Fisher's exact test), abolished brainstem- or papillary reflexes (38%, p less than or equal to 0.05), the combination of these clinical signs (54%, p less than or equal to 0.01), bilateral abolition of elMEPs (38%, p less than or equal to 0.05), magMEPs (38%, p less than or equal to 0.05), or SEPs (23%, p greater than 0.1), or a combination of clinical and EP data (85%, p less than or equal to 0.0005); 2) good outcome was predicted by a GCS of greater than or equal to 8 only in post-traumatic coma, and EPs did not help to predict fatal outcome of coma; 1) if this appears impossible on the basis of clinical data alone; 2) if a second indicator is needed to confirm a clinical impression; 3) SEPs may be first evaluated during the acute stage of coma treatment, because they can be recorded in the presence of anaesthetic or relaxant agents; 4) MEP may be studied if outcome prediction remains ambiguous, and if the clinical situation allows for discontinuation of these agents.
Adolescent↗
Influence of some anesthetic agents on muscle responses to transcranial magnetic cortex stimulation: a pilot study in humans.
The effects of some commonly used intravenous and inhalational anesthetic agents on the motor evoked responses to transcranial magnetic cortex stimulation were assessed in 17 subjects. Compound motor action potentials (CMAPs) of the abductor digiti minimi muscle were recorded. Baseline values (12 stimulations/subject) were established before anesthesia was induced with a single agent administered in steps up to a maximal dose (MaxDose). Cortical stimulation was performed and depth of anesthesia was assessed according to Guedel after each dose. A common feature was the marked intra- and interindividual variability of baseline values of CMAPs in those patients not premedicated, those premedicated, and the anesthetized patients. The average amplitude of CMAPs was related to the depth of anesthesia in a given subject, whereas onset latencies of CMAPs did not systematically change. CMAPs were markedly reduced or abolished after administration of potent sedative drugs such as midazolam (MaxDose, 0.4 mg/kg body weight), pentothal (MaxDose, 8 mg/kg), propofol (MaxDose, 2 mg/kg), and isoflurane (MaxDose, 1.9 and 3.7 vol %), as soon as patients reached Stage II and Stage III anesthesia. When fentanyl (MaxDose, 8 micrograms/kg) or nitrous oxide (MaxDose, 79%) was used, the subjects reached Stages I and II, but not Stage III. With these drugs, reliable recording of CMAPs was possible even with the maximal administered dose.
Action Potentials↗
The in-vitro synthesized tomato shikimate kinase precursor is enzymatically active and is imported and processed to the mature enzyme by chloroplasts.
Full-length cDNA clones encoding shikimate kinase (EC 2.7.1.71), an enzyme of the central section of the shikimate pathway, have been isolated from tomato (Lycopersicon esculentum L., cv. UC82b). The open reading frame has the capacity to encode a peptide of 300 amino acids. The in-vitro synthesized peptide catalysed the phosphorylation of shikimate thus confirming the identity of the isolated cDNA clones. The N-terminal portion of the deduced amino acid sequence resembles known chloroplast-specific transit peptides. The existence of such a transit peptide was proven by the uptake of the in-vitro synthesized peptide as well as its processing by isolated chloroplasts. Multiple sites of polyadenylation were observed in shikimate kinase mRNAs. The results of Northern and Southern blot analyses are consistent with the existence of only one shikimate kinase gene per haploid genome in tomato. These results are discussed with respect to the dual pathway hypothesis of the shikimate pathway in higher plants.
Amino Acid Sequence↗
Molecular cloning and analysis of a cDNA coding for chorismate synthase from the higher plant Corydalis sempervirens Pers.
Chorismate synthase catalyzes the last common step in the biosynthesis of the three aromatic amino acids in microorganisms and plants. We have cloned a cDNA for this enzyme from the higher plant Corydalis sempervirens. This is the first chorismate synthase cDNA from a eukaryotic organism. The nucleotide sequence was determined and the identity of the cDNA was confirmed by the amino acid sequence of tryptic peptides obtained from purified chorismate synthase. The homology to the two known bacterial sequences is about 48%. The cDNA contains an open reading frame of 1341 base pairs, encoding a protein of 447 amino acids. This protein with a molecular mass of 48,100 daltons resembles a chorismate synthase precursor targeted for chloroplast import. Multiple sites of polyadenylation were observed in chorismate synthase mRNAs.
Amino Acid Sequence↗
Chemically bonded phases for the reversed-phase high-performance liquid chromatographic separation of basic substances.
A chemically bonded phase with a peptide group (PB) for reversed-phase high-performance liquid chromatography (HPLC) is described. This packing was prepared by a two-stage modification of the surface of silica gel with mono- and trifunctional 3-aminopropylsilane and then with an appropriate derivative of a fatty acid. Packings prepared in this way were compared with standard C18 materials used in HPLC. Surface characteristics of the packings before and after chemical modification were determined by different physico-chemical methods, e.g., porosimetry, elemental analysis, 13C and 29Si cross-polarization magic angle spinning NMR and HPLC. Chromatographic properties of these packings were evaluated by comparison between log k' of one phase and log k' of a second phase for substances with different chemical natures. The PB packing was found to be especially useful for the separation of basic substances.
Amino Acid Sequence↗
Transcranial magnetic stimulation excites the labyrinthine segment of the facial nerve: an intraoperative electrophysiological study in man.
The site where transcranial magnetic stimulation (magStim) depolarizes the facial nerve was investigated in 6 patients who underwent surgery of the cerebellopontine angle (CPA). The facial nerve was stimulated (1) magnetically prior to craniotomy, (2) electrically near the brainstem (elREZ), (3) at the exit from the CPA into the facial canal (elPorus), and (4) in the stylomastoid fossa (elStylo). The range of latency differences (delta) of compound muscle action potentials (CMAPs) recorded from the ipsilateral mentalis muscle were as follows: delta elREZ-magStim: +0.5 to +1.1 ms (P less than or equal to 0.03, Wilcoxon test); delta elPorus-magStim: +0.2 to +0.5 ms (P less than or equal to 0.03); delta elStylo-magStim: +0.8 to +1.0 ms (P less than or equal to 0.03). On the basis of anatomical data and a facial nerve conduction velocity of 33-46 m/s in these patients, it was concluded that transcranial magnetic stimuli depolarized the facial nerve at a location 10-15 mm distal to its entrance into the facial canal. This corresponds to the end of the labyrinthine segment of the facial nerve, i.e. the transit zone where the nerve ceases to be surrounded by cerebrospinal fluid (CSF) with its high electrical conductivity and enters the high-resistance tissue of the petrous bone.
Action Potentials↗
Plasminogen activator in human periodontal health and disease.
Plasminogen activators, proteases associated with the fibrinolytic system, also play a major part in extravascular processes such as tissue remodelling, cell migration and activation of prohormones, growth factors and other proteases. It is likely that plasminogen activators participate in the pathophysiology of periodontal disease. Plasminogen activator has been identified in human gingival crevicular fluid in a concentration 100-fold greater than in plasma. The local activity of plasminogen activator in gingival tissues was examined and changes detected in its distribution in relation to the extent of disease. Frozen sections from human gingival biopsies were overlaid on fibrin-coated slides; tissue-type plasminogen activator activity was found in all samples. Focal activity was observed in healthy tissue, originating from the most superficial cells of the junctional epithelium. Biopsies of clinically healthy sites obtained 6 weeks after treatment for periodontitis also showed epithelial plasminogen activator activity localized to this area. In contrast, in diseased tissue the entire epithelium lining the periodontal pocket showed activity. This differential pattern of activity in health and disease is consistent with the hypothesis that plasminogen activator is a modulator of periodontal homeostasis.
Gingiva↗
Telomeric and dispersed repeat sequences in Candida yeasts and their use in strain identification.
Several different repetitive DNA sequences have been isolated from the pathogenic yeast Candida albicans. These include two families of large dispersed repeat sequences (Ca3, Ca24) and a short (23-bp) tandemly repeated element (Ca7) associated with C. albicans telomeres. In addition, a large subtelomeric repeat (WOL17) has been cloned. DNA fragments containing the telomeric repeats are highly variable among different C. albicans strains. We have shown that the Ca3 repeat is relatively more stable and is suitable for use as a species-specific and strain-specific probe for C. albicans.
Base Sequence↗
Genetic dissimilarity of commensal strains of Candida spp. carried in different anatomical locations of the same healthy women.
Candida spp. carriage and strain relatedness were assessed in 52 healthy women at 17 anatomical locations by using an isolation procedure which assesses carriage intensity and by using a computer-assisted DNA fingerprinting system which computes genetic similarity between strains on the basis of the patterns of Southern blots probed with the moderately repetitive sequence Ca3. Candida spp. were cultured from 73% of the test individuals, most frequently from the oral (56%), vulvovaginal (40%), and anorectal (24%) regions. Half of the test individuals with Candida spp. carried the organism simultaneously in more than one of the three general areas of carriage. Isolates from different body locations of the same individual were either completely unrelated, identical, or highly similar but nonidentical. In 11 cases in which Candida spp. were simultaneously isolated from the oral cavity and vaginal canal, seven pairs of isolates were genetically unrelated and four pairs were similar but nonidentical. In the latter cases, the isolate pairs each appear to have arisen by genetic divergence from a single progenitor. A comparison of the genetic relatedness of isolates from different individuals further uncovered a single strain which was vaginospecific in the Iowa City, Iowa area and reduced genetic diversity among vulvovaginal strains compared with those isolated from other body locations. These results suggest that strains adapt to different anatomical locations and, conversely, that in a healthy individual there is anatomical selection of vaginotropic, anotropic and orotropic strains of Candida spp.
Adult↗
Influence of peripheral nerve stimulation on the responses in small hand muscles to transcranial magnetic cortex stimulation.
The influence of afferent median nerve stimulation on the responses of small hand muscles (CMAPs) to cortical stimulation (CortStim) was investigated by applying short stimulus trains to the median nerve at the wrist and slightly suprathreshold magnetic stimuli to the scalp. Train stimulus frequency (TSF), train stimulus intensity (TSI), and train onset (TO) in relation to the CortStim were varied. Amplitudes and latencies of CMAPs were compared with those obtained by CortStim alone. When applying short trains of 10 msec duration, of 300/sec-400/sec TSF, and of threshold or supramaximal intensity for motor fibers, both facilitatory and inhibitory effects on the responses to CortStim were achieved depending on the timing of the train onset. With a TO of 8-10 msec before CortStim, mean amplitudes of CMAPs were enhanced 3-10 times; mean amplitudes reached up to 20 times the baseline values when the TO was greater than 45 msec before CortStim. With a TO of 15-35 msec before CortStim, amplitudes were diminished below control values. No systematic changes in latency were noted with TO of 8-10 msec, but when the TO was 45-60 msec before CortStim the latencies of CMAPs were 1.5-3 msec shorter than baseline latencies. With afferent stimuli that were subthreshold for motor fibers facilitation only occurred when the TO was about 45 msec before CortStim. The differences were statistically significant (Wilcoxon-Mann-Whitney Test). This biphasic pattern of facilitation and inhibition probably reflects spinal and supraspinal reflex phenomena mediated by spindle receptor and various cutaneous afferents.
Action Potentials↗
[Does breast self-examination affect the stage of breast carcinoma?].
The regular self-examination of the breast is one of the possibilities to detect breast cancer early. Our aim was to test the sensitivity of the method on rural, poorly informed patients. Almost one fourth of the 90 cancer patients belonged to the self-examination group. 52% of these women had a stage-I tumor. 58% of the women who didn't examine themselves entered hospital with stage-III or stage-IV tumor. In the self-examination group, in 71% of the lymph nodes were negative. This cohort showed also a better result concerning tumor extension. The average size was 1.9 cm compared to 3.8 cm in the 'non-analyser group'. We summarize that women controlling themselves have a better prognosis. Therefore, self-examination, combined with mammography and clinical control, is one of the best methods for early detection of mammary-cancer.
Adult↗
[Disseminated, highly malignant non-Hodgkin's lymphoma and pregnancy: polychemotherapy in the 2d and 3d trimester].
The coincidence of Non-Hodgkin-lymphoma (NHL) and pregnancy is rare. Even rarer is the use of chemotherapy in pregnancy complicated by NHL. We report on a case of malignant NHL IVa, where diagnosis was established in the 24th week of gestation. The patient was treated with polychemotherapy in the second and third trimester of pregnancy and delivered a normal infant. We review the literature and discuss possibilities and risks of chemotherapy in pregnancy.
Adult↗
Developmental and environmental regulation of a bean chalcone synthase promoter in transgenic tobacco.
Regulatory properties of a 1.4-kilobase promoter fragment of the bean chalcone synthase CHS8 gene were examined by analysis of glucuronidase (GUS) activity in transgenic tobacco containing a CHS8-GUS gene fusion. The promoter was highly active in the root apical meristem and in petals, exclusively in those cells of the inner epidermis that accumulate anthocyanins. The gene fusion was only weakly expressed in other floral organs, mature leaves, and stems. The early stages of seedling development were characterized by an apparent wound induction of the promoter in the endosperm and strong expression in the immature root, which became localized to the apical meristem and perivascular tissue at the root-hypocotyl junction. The promoter became active during lateral root formation in both the new root and damaged tissue of the main root. The gene fusion was also expressed in greening cotyledons and primary leaves but not in the shoot apical meristem. Light modulated expression in the cotyledons and root-shoot junction but had no effect on other aspects of the developmental program. Wounding or fungal elicitor treatment of mature leaves activated the promoter in a well-defined zone adjacent to the stress site. Stress induction occurred in mesophyll and vascular tissues as well as in the epidermis. We conclude that the CHS8 promoter contains cis-elements required to establish temporal and spatial control of flavonoid biosynthesis during development and in response to diverse environmental stimuli.
Acyltransferases↗