Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Miniaturization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources
PubMed1999

Miniature inhibitory postsynaptic currents in CA1 pyramidal neurons after kindling epileptogenesis.

Miniature inhibitory postsynaptic currents (mIPSCs) were measured in CA1 pyramidal neurons from long-term kindled rats (>6 weeks after they reached the stage of generalized seizures) and compared with controls. A large reduction in the number of mIPSCs was observed in a special group of large mIPSCs (amplitude >75 pA). The frequency of mIPSCs in this group was reduced from 0.042 Hz in controls to 0.027 Hz in the kindled animals. The reduction in this group resulted in a highly significant difference in the amplitude distributions. A distinction was made between fast mIPSCs (rise time <2.8 ms) and slow mIPSCs. Fast mIPSCs, which could originate from synapses onto the soma and proximal dendrites, had significantly larger amplitudes than slow mIPSCs, which could originate from more distal synapses (35.4 +/- 1.1 vs. 26.2 +/- 0.4 pA in the kindled group; means +/- SE). The difference in the value of the mean of all amplitudes and frequency of fast and slow mIPSCs did not reach significance when the kindled group was compared with controls. The mIPSC kinetics were not different after kindling, from which we conclude that the receptor properties had not changed. Nonstationary noise analysis of the largest mIPSCs suggested that the single-channel conductance and the number of postsynaptic receptors was similar in the kindled and control groups. Our results suggest a 40-50% reduction in a small fraction of (peri-) somatic synapses with large or complex postsynaptic structure after kindling. This functionally relevant reduction may be related to previously observed loss of a specific class of interneurons. Our findings are consistent with a reduction in inhibitory drive in the CA1 area. Such a reduction could underlie the enhanced seizure susceptibility after kindling epileptogenesis.

Animals↗
PubMed1999

GABA(A) receptor-mediated miniature postsynaptic currents and alpha-subunit expression in developing cortical neurons.

Previous studies have described maturational changes in GABAergic inhibitory synaptic transmission in the rodent somatosensory cortex during the early postnatal period. To determine whether alterations in the functional properties of synaptically localized GABA(A) receptors (GABA(A)Rs) contribute to development of inhibitory transmission, we used the whole cell recording technique to examine GABAergic miniature postsynaptic currents (mPSCs) in developing cortical neurons. Neurons harvested from somatosensory cortices of newborn mice showed a progressive, eightfold increase in GABAergic mPSC frequency during the first 4 wk of development in dissociated cell culture. A twofold decrease in the decay time of the GABAergic mPSCs, between 1 and 4 wk, demonstrates a functional change in the properties of GABA(A)Rs mediating synaptic transmission in cortical neurons during development in culture. A similar maturational profile observed in GABAergic mPSC frequency and decay time in cortical neurons developing in vivo (assessed in slices), suggests that these changes in synaptically localized GABA(A)Rs contribute to development of inhibition in the rodent neocortex. Pharmacological and reverse transcription-polymerase chain reaction (RT-PCR) studies were conducted to determine whether changes in subunit expression might contribute to the observed developmental alterations in synaptic GABA(A)Rs. Zolpidem (300 nM), a subunit-selective benzodiazepine agonist with high affinity for alpha1-subunits, caused a reversible slowing of the mPSC decay kinetics in cultured cortical neurons. Development was characterized by an increase in the potency of zolpidem in modulating the mPSC decay, suggesting a maturational increase in percentage of functionally active GABA(A)Rs containing alpha1 subunits. The relative expression of alpha1 versus alpha5 GABA(A)R subunit mRNA in cortical tissue, both in vivo and in vitro, also increased during this same period. Furthermore, single-cell RT-multiplex PCR analysis revealed more rapidly decaying mPSCs in individual neurons in which alpha1 versus alpha5 mRNA was amplified. Together these data suggest that changes in alpha-subunit composition of GABA(A)Rs contribute to the maturation of GABAergic mPSCs mediating inhibition in developing cortical neurons.

Animals↗
PubMed2000

Properties of miniature glutamatergic EPSCs in neurons of the locomotor regions of the developing zebrafish.

As a first step in understanding the development of synaptic activation in the locomotor network of the zebrafish, we examined the properties of spontaneous, glutamatergic miniature excitatory postsynaptic currents (mEPSCs). Whole cell patch-clamp recordings were obtained from visually identified hindbrain reticulospinal neurons and spinal motoneurons of curarized zebrafish 1-5 days postfertilization (larvae hatch after the 2nd day of embryogenesis). In the presence of tetrodotoxin (TTX) and blockers of inhibitory receptors (strychnine and picrotoxin), we detected fast glutamatergic mEPSCs that were blocked by the AMPA/kainate receptor-selective antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). At positive voltages or in the absence of Mg(2+), a second, slower component of the mEPSCs was revealed that the N-methyl-D-aspartate (NMDA) receptor-selective antagonist DL-2-amino-5-phosphonovalerate (AP-5) abolished. In the presence of both CNQX and AP-5, all mEPSCs were eliminated. The NMDA component of reticulospinal mEPSCs had a large single-channel conductance estimated to be 48 pS. Larval AMPA/kainate and NMDA components of the mEPSCs decayed with biexponential time courses that changed little during development. At all stages examined, approximately one-half of synapses had only NMDA responses (lacking AMPA/kainate receptors), whereas the remainder of the synapses were composed of a mixture of AMPA/kainate and NMDA receptors. There was an overall increase in the frequency and amplitude of mEPSCs with an NMDA component in reticulospinal (but not motoneurons) during development. These results indicate that glutamate is a prominent excitatory transmitter in the locomotor regions of the developing zebrafish and that it activates either NMDA receptors alone at functionally silent synapses or together with AMPA/kainate receptors.

2-Amino-5-phosphonovalerate↗
PubMed2000

Short-term potentiation of miniature excitatory synaptic currents causes excitation of supraoptic neurons.

Magnocellular neurons (MCNs) of the hypothalamic supraoptic nucleus (SON) secrete vasopressin and oxytocin. With the use of whole-cell and nystatin-perforated patch recordings of MCNs in current- and voltage-clamp modes, we show that high-frequency stimulation (HFS, 10-200 Hz) of excitatory afferents induces increases in the frequency and amplitude of 2,3-dioxo-6-nitro-1,2,3, 4-tetrahydrobenzo(f)quinoxaline-7-sulfonamide (NBQX)-sensitive miniature excitatory postsynaptic currents (mEPSCs) lasting up to 20 min. This synaptic enhancement, referred to as short-term potentiation (STP), could be induced repeatedly; required tetrodotoxin (TTX)-dependent action potentials to initiate, but not to maintain; and was independent of postsynaptic membrane potential, N-methyl-D-aspartate (NMDA) receptors, or retrograde neurohypophyseal neuropeptide release. STP was not accompanied by changes in the conductance of the MCNs or in the responsiveness of the postsynaptic non-NMDA receptors, as revealed by brief application of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate. mEPSCs showed similar rise times before and after HFS and analysis of amplitude distributions of mEPSCs revealed one or more peaks pre-HFS and the appearance of additional peaks post-HFS, which were equidistant from the first peak. STP of mEPSCs was not associated with enhanced evoked responses, but was associated with an NBQX-sensitive increase in spontaneous activity of MCNs. Thus we have identified a particularly long-lasting potentiation of excitatory synapses in the SON, which has a presynaptic locus, is dissociated from changes in evoked release, and which regulates postsynaptic cell excitability.

Animals↗
PubMed2001

Number of K(Ca) channels underlying spontaneous miniature outward currents (SMOCs) in mudpuppy cardiac neurons.

Spontaneous miniature outward currents (SMOCs) in parasympathetic neurons from mudpuppy cardiac ganglia are caused by activation of TEA- and iberiotoxin-sensitive, Ca(2+)-dependent K(+) (BK) channels. Previously we reported that SMOCs are activated by Ca(2+)-induced Ca(2+) release (CICR) from caffeine- and ryanodine-sensitive intracellular Ca(2+) stores. In the present study, we analyzed the single channel currents that contribute to SMOC generation in mudpuppy cardiac neurons. The slope conductance of BK channels, determined from the I-V relationship of single-channel currents recorded with cell-attached patches in physiological K(+) concentrations, was 84 pS. The evidence supporting the identity of this channel as the channel involved in SMOC generation was its sensitivity to internal Ca(2+), external TEA, and caffeine. In cell-attached patch recordings, 166 microM TEA applied in the pipette reduced single-channel current amplitude by 32%, and bath-applied caffeine increased BK channel activity. The ratio between the averaged SMOC amplitude and the single-channel current amplitude was used to estimate the average number of channels involved in SMOC generation. The estimated number of channels involved in generation of an averaged SMOC ranged from 18 to 23 channels. We also determined that the Po of the BK channels at the peak of a SMOC remains constant at voltages more positive than -20 mV, suggesting that the transient rise in intracellular Ca(2+) from ryanodine-sensitive intracellular stores in the vicinity of the BK channel reached concentrations most likely exceeding 40 microM.

Animals↗
PubMed1999

Treatment of stable and recalcitrant vitiligo by autologous miniature punch grafting: a prospective study of 1,000 patients.

BACKGROUND: Stable and refractory vitiligo may be unresponsive to medical therapy. Melanocyte transplantation by punch grafting (PG) can restore the normal pigmentation. OBJECTIVE: To evaluate the efficacy of PG on repigmentation of vitiligo patches. METHODS: Autologous miniature PG was undertaken in 1,000 patients with stable and recalcitrant vitiligo. Test grafting (TG) was done in all the patients. Those who showed negative TG results were excluded from the study. RESULTS: Of the 1,000 patients, 880 (88%) showed positive TG results. In 656 (74.55%) patients, 90-100% repigmentation was achieved. In 93 (10.57%) patients, there was no spread of pigment, while in 21 (2.39%) patients depigmentation of the graft(s) was notices. Of various complications, polka dot appearance (43.98%) and colour mismatch (34.32%) were most frequent. CONCLUSION: Partial to near-total repigmentation of a vitiligo patch can be achieved by PG.

Adolescent↗
PubMed2001

Miniature multileaf collimator as an alternative to traditional circular collimators for stereotactic radiosurgery and stereotactic radiotherapy.

PURPOSE: To evaluate the miniature multileaf collimator (MMLC) as an alternative to traditional circular collimators for radiosurgery. MATERIALS AND METHODS: 'Circular' fields were created with the Radionics MMLC (leaf width 3.53 mm at isocenter). Beam data, including tissue maximum ratios, output factors, penumbrae and isodose distributions of these fields were measured. These were compared to the Radionics circular collimators traditionally used for radiosurgery. The MMLC data were input to the XKnife Treatment Planning System. Treatment plans were completed and evaluated using both the MMLC 'circular' fields and the circular collimators. RESULTS: MMLC fields using 3, 5, 7, 9, 11, and 13 leaves on each side of the Radionics MMLC were created to approximate circular fields. The TMRs are essentially identical to those of comparable-size circular collimators. Measured at isocenter at 5-cm depth for 6 MV, the 80-20% penumbra widths are comparable to circular collimators, but are increased by as much as 1 mm at the leaf intersections (steps) where scalloping occurs. Isodose distributions were matched to those of circular collimators with comparable 50% isodose widths. Treatment plans for the MMLC 'circular' fields with four arcs (totaling 360 degrees) are essentially identical to those of comparable circular collimators. Dose-volume histograms revealed clinically insignificant differences between the two in doses to the target, to the volume surrounding the target, and to adjacent critical normal tissues. There is very little discrepancy between the dose distribution calculated with the approximated MMLC fields and with those of simulated arcs with the actual MMLC fields. CONCLUSIONS: With the MMLC simulating circular fields, dose distributions may be obtained which are essentially identical to comparable-size circular collimators. The mechanical accuracy of the MMLC is as good as that of the circular collimators, and the leakage dose is less. The diameter of 'circular' fields is limited by the MMLC leaf width to 1 cm and greater in increments of 7 mm. Attention needs to be paid to mechanical collisions because the MMLC is bulkier than the circular collimators.

Humans↗
PubMed2002

Stereotactic interstitial radiosurgery with a miniature X-ray device in the minimally invasive treatment of selected tumors in the thalamus and the basal Ganglia.

The aim of this study was to evaluate the role of interstitial radiosurgery (IR) using the photon radiosurgery system (PRS) in the treatment of selected tumors within the thalamus and the basal ganglia. The PRS is a miniature X-ray generator that was developed for interstitial irradiation. This series included 14 patients (5 with glioblastomas, 4 with low-grade astrocytomas and 5 with metastases) harboring spheroidal lesions with dimensions ranging from 13 to 42 mm (mean 30 mm). After stereotactic biopsy, a radiation dose ranging from 6 to 15.4 Gy (mean 11.3 Gy) was delivered at the target volume margins. Follow-up varied from 3 to 26 months (mean 10.2 months). In the group of glioblastomas, 3 patients died (3-12 months after the procedure) because of tumor progression, while the remaining had tumor control. Two patients with metastases died from systemic disease (4-9 months after the treatment), and 3 were alive and well at the end of the study. Local control was achieved in all metastases. Patients with low-grade astrocytomas were well and imaging studies showed tumor control PRS IR is a minimally invasive procedure for the treatment of selected glial or secondary brain tumors. Compared to conventional radiosurgery (brachytherapy and external radiosurgery), PRS IR presents dose delivery characteristics useful for the treatment of tumors in the thalamus and basal ganglia, without inconveniences such as handling radioisotopes, the need of expensive facilities and radiation protection measures. Although the clinical value needs further investigations, PRS IR seems to be effective in metastases while it provides less benefit in malignant gliomas. PRS IR could have a major role in the treatment of low-grade astrocytomas.

Adolescent↗
PubMed1996

Mandibular molar teeth and the development of mastication in the miniature pig (Sus scrofa).

The only components of the orofacial complex that are fully developed as soon as they establish function are the occlusal surfaces of teeth. It is usually assumed that the occlusal surface of the molar teeth influences the orientation of the power stroke in spite of the fact that the data supporting this claim are lacking. The purpose of this longitudinal study was therefore to determine whether or not this hypothetical form-function relationship existed during development and whether or not it was related to growth. Serial dorsoventral and lateral radiography, and dorsoventral cineradiography were performed during natural feeding of 5 Hanford miniature pigs (Sus scrofa) of both genders between their 8th and 18th weeks. Sequences of power strokes were analyzed frame by frame and compared between sessions, and related to the position of the fourth primary mandibular molar (dm4). The changes in direction of the power stroke and in position of the dm4 relative to the midline were subsequently related to growth. The results of this study indicate that changes in orientation of the power stroke, though significant only on the balancing side, occur independently of the repositioning working and balancing side mandibular molars, as well as of skeletal growth. The null hypothesis that the mandibular primary molars influence the transverse orientation of the power stroke during growth is therefore refuted.

Animals↗
PubMedDate not supplied

Baroreflex control of renal sympathetic nerve activity in hypertensive miniature swine.

The baroreceptor reflex control of renal nerve activity was examined in seven normotensive and 14 deoxycorticosterone acetate-treated anesthetized Yucatan miniature swine. Pressor responses evoked by the administration of phenylephrine were used to assess reflex control. The mean absolute threshold for inhibition of renal nerve activity was higher but not significantly different between the deoxycorticosterone acetate-treated and normotensive group. However, the mean relative threshold for inhibition of renal nerve activity was significantly greater in the deoxycorticosterone acetate-treated group (p less than 0.05). Responses from five deoxycorticosterone acetate-treated and five normotensive swine were used to examine the time course of the baroreflex inhibition of renal nerve activity. During the initial rise in pressure the percent inhibition of renal nerve activity was similar for the two groups. During the recovery phase of the response, renal nerve activity in the deoxycorticosterone acetate-treated group returned to baseline while renal nerve activity remained attenuated below baseline in the normotensive group. The gain of the reflex was significantly lower in the deoxycorticosterone acetate-treated group compared with the control group (p less than 0.05). The results of this study clearly indicate that baroreceptor reflex control of renal nerve activity is altered in anesthetized deoxycorticosterone acetate-treated hypertensive swine.

Animals↗
PubMed1987

Pathogenesis of coronary artery spasm in miniature swine with regional intimal thickening after balloon denudation.

Pathogenesis of coronary artery spasm induced by histamine in miniature pigs was studied angiographically in in vivo and in vitro conditions. Endothelial balloon denudation was performed and the animals were fed laboratory chow for 3 months, after which coronary artery spasm was repeatedly provoked by histamine given intracoronarily. Regional hypercontraction of the coronary artery was documented by selective coronary arteriography, and the resulting myocardial ischemia was confirmed by ECG-ST changes. To evaluate coronary artery spasm without the influence of blood constituents and neural control and to quantitate the pharmacophysiological characteristics of histamine-induced coronary constriction in the coronary spasm, the same heart was isolated and perfused with Krebs-Henseleit solution under a constant perfusion pressure of 90 mm Hg. Histamine (10(-5) M) reduced the diameter of the coronary artery of the isolated heart by 29 +/- 4 and 67 +/- 3% (p less than 0.001) in nondenuded and denuded areas, respectively. These figures were similar to data obtained angiographically in vivo after the administration of histamine 10 micrograms/kg. The constriction of the denuded areas in response to histamine was topologically the same in vivo and in vitro. The degree of focal constriction induced by histamine, defined as a percent of stenoses from the mean diameter of the areas of proximal and distal to the spastic site, was similar in in vivo (10 micrograms/kg i.c.) and in vitro (10(-5) M) conditions. KCl (40 mM) reduced both the denuded and nondenuded coronary artery diameter by 67 +/- 3% and 68 +/- 3% (NS), respectively. The dose-response relation of the coronary diameter to histamine was not influenced by pretreatment with the nerve transmitter blockers guanethidine (3 X 10(-6) M), atropine (10(-6) M), and tetrodotoxin (3 X 10(-7) M). Phenylephrine (10(-5) M) did not potentiate constriction of the denuded areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Native and nonnative speakers' processing of a miniature version of Japanese as revealed by ERPs.

Several event-related potential (ERP) studies in second language (L2) processing have revealed a differential vulnerability of syntax-related ERP effects in contrast to purely semantic ERP effects. However, it is still debated to what extent a potential critical period for L2 acquisition, as opposed to the attained proficiency level in the L2, contributes to the pattern of results reported in previous ERP studies. We studied L2 processing within the model of a miniature version of a natural language, namely Japanese, specifically constructed to assure high proficiency of the learners. In an auditory ERP experiment, we investigated sentence processing of the "Mini-Japanese" in Japanese native speakers and German volunteers before and after training. By making use of three different types of violation, namely, word category, case, and classifier violations, native and nonnative ERP patterns were compared. The three types of violation elicited three characteristic ERP patterns in Japanese native speakers. The word category violation elicited an anteriorly focused, broadly distributed early negativity followed by a P600, whereas the case violation evoked a P600 which was preceded by an N400. The classifier violation led solely to a late left distributed negativity with an anterior focus. Although the P600 was similar for Japanese natives and learners, the N400 and the anterior negativities were not present in the learner group. The differences across groups suggest deviant neural processes in on-line syntactic and thematic processing in the L2 learners despite high behavioral skills.

Acoustic Stimulation↗
PubMed2003

Miniaturized multichannel near infrared endoscope for mouse imaging.

We describe the design and construction of a miniaturized multichannel near infrared (NIR) endoscopic imaging system developed for high-resolution imaging of mice. The device allows for simultaneous real-time video images in white light and two independent NIR channels. Testing demonstrated independent acquisition of nanomolar concentrations of fluorochromes Cy5.5 and Cy7. Cross-talk between the NIR channels, partially a result of broad tails in the spectra of commonly used organic fluorochromes, was assessed, modeled for the linear range of the concentration/signal intensity function, and compensated. The calculated compensation was 5.5% and 22% of the total signal intensity in the two channels NIR700 and NIR780, respectively, at equal concentrations of the two fluorochromes. Using a mouse model of colonic adenomatosis, we show that both perfusion and protease activity can be detected simultaneously, independently, and repeatedly in live mice. The developed device should be useful for in vivo imaging of diverse molecular targets.

Adenoma↗
PubMed2006

Anatomical substrates of visual and auditory miniature second-language learning.

Longitudinal changes in brain activity during second language (L2) acquisition of a miniature finite-state grammar, named Wernickese, were identified with functional magnetic resonance imaging (fMRI). Participants learned either a visual sign language form or an auditory-verbal form to equivalent proficiency levels. Brain activity during sentence comprehension while hearing/viewing stimuli was assessed at low, medium, and high levels of proficiency in three separate fMRI sessions. Activation in the left inferior frontal gyrus (Broca's area) correlated positively with improving L2 proficiency, whereas activity in the right-hemisphere (RH) homologue was negatively correlated for both auditory and visual forms of the language. Activity in sequence learning areas including the premotor cortex and putamen also correlated with L2 proficiency. Modality-specific differences in the blood oxygenation level-dependent signal accompanying L2 acquisition were localized to the planum temporale (PT). Participants learning the auditory form exhibited decreasing reliance on bilateral PT sites across sessions. In the visual form, bilateral PT sites increased in activity between Session 1 and Session 2, then decreased in left PT activity from Session 2 to Session 3. Comparison of L2 laterality (as compared to L1 laterality) in auditory and visual groups failed to demonstrate greater RH lateralization for the visual versus auditory L2. These data establish a common role for Broca's area in language acquisition irrespective of the perceptual form of the language and suggest that L2s are processed similar to first languages even when learned after the "critical period." The right frontal cortex was not preferentially recruited by visual language after accounting for phonetic/structural complexity and performance.

Acoustic Stimulation↗
PubMed1983

Murine pulmonary macrophages: evaluation of lung lavage fluids, miniaturized monolayers, and candidacidal activity.

Optimal yields of pulmonary macrophages (PuM) from lavage of normal murine lungs have been obtained by the study of several different lung lavage fluids. Approximately 1 X 10(6) PuM can be consistently recovered from mice weighing 20 to 30 g, using 15 ml of phosphate buffered saline with 0.1% EDTA, with or without 10% fetal calf serum at 37 degrees C. Use of Terasaki tray wells for monolayer formation has allowed a relatively small number of cells (75,000) to be used to prepare multiple replicate wells from each mouse. Simultaneous functional comparisons with other cell types, e.g., peritoneal macrophages (PeM) were performed using this practical and economical system. Data on the phagocytosis and killing of Candida albicans by PuM and PeM are presented as evidence of the utility of this miniaturized system.

Animals↗
PubMed1997

Novel instrumentation for real-time monitoring using miniaturized flow systems with integrated biosensors.

A prototype miniaturized Total Chemical Analysis System (muTAS) has been developed and applied to on-line monitoring of glucose and lactate in the core blood of anaesthetized dogs. The system consists of a highly efficient microdialysis sampling interface sited in a small-scale extracorporeal shunt circuit ('MiniShunt'), a silicon machined microflow manifold and integrated biosensor array for glucose and lactate detection with associated computer software for analytical process control. During in-vivo testing the device allowed real-time on-screen monitoring of glucose and lactate with system response times of less than 5 min, made possible by the small dead volume of the microflow system. On-line glucose and lactate measurements were made in the basal state as well as during intravenous infusion of glucose or lactate. The prototype muTAS is currently suitable for trend monitoring but refinements are necessary before application of the system for determination of individual lactate values.

Animals↗
PubMedDate not supplied

Development and evaluation of porous dental implants in miniature swine.

Organized bone ingrowth in endosteal porous implants fabricated from VMC titanium alloy and surgically implanted with a tight interference fit, securely anchored the implants in fresh and healed mandibular premolar sites of miniature swine. This bone-implant union retained its integrity under high as well as slight masticatory stresses up to one-year after implantation. Bone invasion of the alumina porcelain implants was impeded by the lack of adequate interconnecting porosity; when the porosity was increased, insufficient ceramic strength prohibited a tight initial bone-implant fit. As a consequence, inadequate initial implant stability resulted in a soft tissue encapsulation of the majority of the ceramic implants. Histological examination and mechanical testing results were similar for bone-ingrown implants exposed to different experimental stresses for 4, 5, 8, and 12 months. Bone ingrowth and interface shear strengths were also similar in the different VMC pore sizes and shapes investigated. The design of intraoral attachments appeared critical, at least in swine where no postoperative treatment was administered. Gingival inflammation and alveolar bone resorption caused by calculus were severe around truncated cone-shaped devices. Slender transgingival posts, occlusal caps, and crown restorations were less susceptible to calculus accumulation, resulting in a more satisfactory gingival and subgingival response. Excessive epithelial invagination was a problem only in implants with transgingival truncated cones. Good adherence of soft tissue to metal under the gingival mucosa prevented epithelial migration around implants with other transgingival devices. Alveolar bone resportion around the tops of bone-ingrown implants was minimal at the time intervals examined (up to one year); however, a definite conclusion should be delayed until longer-term implants under full occlusion are evaluated.

Aluminum↗
PubMed1982

EMG approach to assessing tongue activity using miniature surface electrodes.

Miniature surface electrodes were developed to examine the EMG activity of the tongue during various functions under normal physiological conditions with minimal fear and discomfort to human subjects. An outline of the electrodes, which consist of electrically high-conductive silver paste, small rubber caps, and fine wires, is introduced, and the practicability of their clinical application is discussed.

Adolescent↗