Microdroplet Technique Research Articles

Lip Augmentation with Liquid Silicone

Many fillers have been used to augment the lips. One of these that has provided long-term satisfactory results is liquid silicone. To demonstrate the efficacy and safety of lip augmentation with liquid silicone. Following a discussion of the benefits and risks of the procedure and the benefits and risks of alternatives and after answering all of the patients' questions, an informed consent form was signed. After obtaining anesthesia with a regional nerve block of the infraorbital and mental nerves, 0.25 to 0.5 cc of liquid silicone (1,000 centistokes) was injected using the microdroplet technique into the vermilion border of both the upper and lower lips. Depending on the desire of the patient, the procedure was repeated monthly. The augmentation of the lips was documented with histology, micrometry, and digital photography. Lip augmentation was achieved gradually during the months following liquid silicone injections into the vermilion border of the lips in the 608 patients studied. Most of the patients requested a second and third injection session. The results were most dramatic in the patients with type I and type II lips and less satisfactory in patients with type III lips. Bruising occurred in the majority of the patients. Eleven patients (2%) developed small palpable granulomas. These granulomas either required no treatment, responded to steroid injections, or were excised. The use of liquid silicone remains an effective method of lip augmentation. It returns the adolescent vermilion curl to the lips.

Liposuction

Through the appropriate use of tumescent anesthesia and the use of modern instruments and techniques, liposuction surgery has become a low-risk procedure which produces predictable and aesthetically pleasing results. New indications for liposuction surgery include lipedema and cellulite. Vibration-assisted liposuction has proven to be especially gentle to the tissues. The induced tissue contraction helps to create better results in correction procedures after less-than-satisfactory liposuction. Autologous fat transfer is also firmly established as an augmentation procedure. In liporecycling, the fat obtained during reduction liposuction is used elsewhere for augmentation. New approaches in fat transfer include the microdroplet technique, flatter injection approaches and three-dimensional tissue augmentation.

Injecting 1000 centistoke liquid silicone with ease and precision.

Since the Food and Drug Administration approved the use of the 1000 centistoke liquid silicone, Silikon 1000, for intraocular injection, the off-label use of this injectable silicone oil as a permanent soft-tissue filler for facial rejuvenation has increased in the United States. Injecting liquid silicone by the microdroplet technique is the most important preventive measure that one can use to avoid the adverse sequelae of silicone migration and granuloma formation, especially when injecting silicone to improve small facial defects resulting from acne scars, surgical procedures, or photoaging. To introduce an easy method for injecting a viscous silicone oil by the microdroplet technique, using an inexpensive syringe and needle that currently is available from distributors of medical supplies in the United States. We suggest the use of a Becton Dickinson 3/10 cc insulin U-100 syringe to inject Silikon 1000. This syringe contains up to 0.3 mL of fluid, and its barrel is clearly marked with an easy-to-read scale of large cross-hatches. Each cross-hatch marking represents either a unit value of 0.01 mL or a half-unit value of 0.005 mL of fluid, which is the approximate volume preferred when injecting liquid silicone into facial defects. Because not enough negative pressure can be generated in this needle and syringe to draw up the viscous silicone oil, we describe a convenient and easy method for filling this 3/10 cc diabetic syringe with Silikon 1000. We have found that by using the Becton Dickinson 3/10 cc insulin U-100 syringe, our technique of injecting minute amounts of Silikon 1000 is facilitated because each widely spaced cross-hatch on the side of the syringe barrel is easy to read and measures exact amounts of the silicone oil. These lines of the scale on the syringe barrel are so large and clearly marked that it is virtually impossible to overinject the most minute amount of silicone. Sequential microdroplets of 0.01 cc or less of Silikon 1000 can be measured and injected with the greatest ease and precision so that inadvertent overdosing and complications can be avoided.

Transfer Mechanism of Dodecyl Sulfate with Methylene Blue across an Oil/Water Interface Studied by Single-Droplet Injection and Microabsorption Methods

Abstract The ion-pair extraction mechanism in a dodecyl sodium sulfate (Na+DS−)/Methylene Blue (MB+Cl−) system was kinetically investigated by single microdroplet techniques. A single tributyl phosphate microdroplet was injected into an aqueous solution and the extraction rate of MB+ by DS− into the single droplet was measured with time using a microabsorption method. The MB+ concentration in the droplet at the extraction equilibrium was independent of the pH in water, while the extraction rate was highly influenced by the pH. The characteristic pH dependence of the MB+/DS− extraction was considered in terms of the mass transfer of MB+, DS− and H+ as individual ions across the oil/water interface.

Gel microdroplet technique leaving microorganisms alive for sorting by flow cytometry

Fluorescent labels used to disclose cellular function and the like are generally needed for cytometric analysis, but suitable ones are not always available. Thiamin, an example of such a label, was used as a model in this study. Thiamin in cells of bakers’ yeast can be chemically converted to thiochrome, which fluoresces strongly, but the reaction kills cells not protected inside a gel microdroplet (GMD). Our new procedure for preparation of a small amount of GMDs uses a glass filter with micropores uniform in size to make an emulsion of molten agar in mineral oil that is then chilled for gelation of the agarose. Cells were suspended and mixed with the warm agarose, which was used to make GMDs. Cells were grown into microcolonies in the GMDs, which were then treated to convert thiamin to thiochrome. The thiochrome in microcolonies in single GMDs could be detected by flow cytometry. Plating showed that enough cells survived for this method to be used for screening. This technique can be used for all applications of GMDs.

Fluorescence imaging of single molecules in polymer microspheres.

We report on far-field fluorescence imaging of single molecules in spherical polymer microparticles produced from solution by using microdroplet techniques. The fluorescence photobleaching quantum yields of rhodamine 6G in a common water-soluble polymer (polyvinyl alcohol) are at least five times smaller, corresponding to proportionally larger average fluorescence signals, than those in ethanolic solvents. This allows for acquisition of multiple images from a single molecule on a time scale of several minutes. We also show that fluorescent images of single molecules in microspheres can be calculated from semiclassic electrodynamics, which may ultimately be useful in retrieving dynamical information from experimental images.

The microdroplet test: experimental and finite element analysis of the dependance of failure mode on droplet shape

The microdroplet technique is usually designed as a fibre embedded in a drop of resin and subsequently pulled out while the drop is being supported by two knife edges, resulting in either debonding of the droplets from the fibres, or breakage of the fibres before debonding can occur. In this study, the microdroplet technique was performed using a platinum ring with a 40 μm hole instead of the usual two knife edges, giving an axisymmetric geometry, load and stress distribution. Glass/phenolic and glass/polyester composite systems were tested experimentally and subsequent finite element modelling studies were performed to assess the variation of droplet size, and contact angle between the droplet and fibre. It was found that contact angle is of major influence in the proposed failure model. This study characterizes the influence of the contact angle between the droplet and the fibre on the subsequent stress distribution in the microdroplet specimen.

Complications of Silicone Injections

Correction of rhytides with injections of medical grade 350 centistoke silicone by the microdroplet technique was performed for many years until a ban

Measurement of interfacial shear strength of ultra-high modulus carbon fibers and its effects on macromechanical properties of CFRP

Ultra-high tensile modulus (700 GPa) pitch-based carbon fiber was systematically surface treated, and interfacial shear strength (IFSS) between the fiber and epoxy resin was measured by micro-droplet method; then, relations between the IFSS and several mechanical properties of the corresponding CFRP were investigated. First, the method of measuring IFSS of very thin and fragile fiber by micro-droplet technique was developed by modifying the shape of specimen. IFSS was related to fiber surface oxygen, which seems to be related to functional groups on the fiber surface. Next, 0° tensile, 0° flexural and 0° compressive properties, 90° tensile strength, interlaminar shear strength (ILSS), and 0° Izod resistance were measured and were related to the IFSS. On the 0° compressive test, delamination was not the dominant failure mode and hence the compressive strength did not change with IFSS. ILSS was measured by double notch shear method, and was proportional to the IFSS. 90° tensile strength increased with incre...

Development of a micro-droplet technique for wettability studies: Application to the Al-Si/SiC system

Development of a micro-droplet technique for wettability studies: Application to the Al-Si/SiC system

A method to extend the application of microdroplet techniques in the SEM

SummaryA thin‐film method of microdroplet analysis is described. The method differs from those published previously. First, uniformly distributed amorphous deposits of chemicals were obtained through the use of a non‐aqueous anti‐crystallization agent, ethylene glycol, which has not been described previously. Second, films of celloidin were used; these could be prepared routinely at 60–80 nm and contained no interfering elements. Initially, these films were too unstable to be of use, but heating them at 60°C greatly improved their stability. A nebulizer was used to deliver microdroplets to these supports, which were, in turn, supported by a specially constructed carbon holder. Minimum detectable concentrations were improved with this method.

Improved microdroplet method for quantitative X-ray microanalysis of small fluid samples

Current microdroplet techniques for very small volumes of fluid tend to be cumbersome and obtaining sufficiently thin droplets with small crystals is difficult. Several alterations to existing microdroplet techniques were tested. Addition of a macro-molecular solute (PVP) facilitated production of thin droplets and reduced crystal size by a very simple method involving slow drying under liquid paraffin oil. Introduction of a different reference element (rubidium) also caused a reduction in crystal size. The new method was compared with existing methods.

Application of the Microdroplet Method of X-Ray Analysis to the Characterization of Inks

Abstract This study was undertaken to investigate the application of the microdroplet method of x-ray analysis to the characterization of inks. A methodology to allow the microdroplet method to be applied to ink analysis was designed. Ethylene glycol was the preferred solvent for droplet formation. Pyridine was added to this solvent to improve ink extraction capabilities, and could then be removed selectively by vacuum evaporation. Microdroplets were delivered to a thin film support through the use of a nebuliser. Thin films of celloidin were supported on copper specimen grids which were in turn held on a specially designed carbon holder. A number of different inks were examined using both a previously described method and the newly designed microdroplet technique. Examination of 17 inks from ballpoint pens commonly available in Australia showed that no detectable elements were present that could be used for characterization. This result was in contrast to earlier work by Harada in Japan. Four fountain pen inks were also examined and it was found that all of these inks contained detectable elements that could be used for characterization.

Quantitative X-ray analysis of biological fluids: the microdroplet technique.

X-ray microanalysis can be used to quantitatively determine the elemental composition of microvolumes of biological fluids. This article describes the various steps in preparation of microdroplets for analysis: The manufacturing of micropipettes, the preparation of the specimen support, the deposition of droplets on the support, shock-freezing, and lyophilization. Examples of common artifacts (incomplete rehydration prior to freezing or partial rehydration after lyophilization) are demonstrated. Analysis can be carried out either by wavelength-dispersive analysis, which is the most sensitive method, or by energy-dispersive analysis, which is more commonly available. The minimum detectable concentration is 0.05 mmol.liter-1 for 0.1-nl samples analyzed by wavelength-dispersive spectrometry and 0.5-1 mmol.liter-1 for samples analyzed by energy-dispersive spectrometry. A major problem, especially in wavelength-dispersive analysis, where high beam currents are used, is radiation damage to the specimen; in particular chloride (but also other elements) can be lost. Quantitative analysis requires the use of standard solutions with elemental concentration in the same range as those present in the specimen.

Interactions between a commercial preparation of Bacillus thuringiensis and β-exotoxin in the fall armyworm, Spodoptera frugiperda

A commercial preparation of Bacillus thuringiensis (Dipel) and its β-exotoxin were assayed alone and in combination against neonate (3- to 6-hr-old) fall armyworm, Spodoptera frugiperda, larvae using a microdroplet technique. Positive dosage-mortality response curves were determined for each agent. Combination bioassays were then conducted using dosages based on these curves. Presence or absence of interactions was determined by comparing mortality levels from the combination assays with expected mortality levels using single degree of freedom χ 2 tests. Synergism occurred in 14 of 18 combinations of B. thuringiensis and β-exotoxin tested. Four combinations, all of which contained low individual dosages, exhibited additivity of effects. Maximum deviation of observed from expected mortality occurred at the combination of LC 30 for B. thuringiensis plus LC 30 for β-exotoxin (observed = 100%, expected = 51%). The data suggested that both agents were contributing to the synergism in this system, but that B. thuringiensis was a slightly stronger synergist than β-exotoxin.

Rhinoplastic revisions with injectable silicone.

We report 20 years of experience with conservative and cautious injection of small amounts of medical-grade liquid silicone in 347 postrhinoplasty patients for a total of 1,937 treatments. Medical-grade silicone was found to be a safe, effective, and valuable adjunct to cosmetic rhinoplastic procedures. Microdroplet technique with very small doses is recommended for the correction of nasal defects that may not be amenable to revisional surgery. Controlled release of this material to the medical profession after appropriate evaluation is recommended, along with proper training prior to its use.

Effect of prostaglandins on polymorphonuclear leukocyte motolity

The effect of prostaglandins (PGE1, E2, F2α on LIF production, LIF activity, and on the random migration of polymorphonuclear leukocytes was investigated. Concanavalin A-induced LIF production was tested in an indirect LIF assay using agarose microdroplet technique; PGE1 and PGE2 inhibited the LIF production. PGE1, PGE2, and F2α in physiological concentration, decreased the random migration of leukocytes, they also interfered with the LIF activity of supernatants, decreasing their inhibitory effect on cell migration; but the opposite explanation that LIF-treated PMNs escaped the inhibitory effect of PGs, cannot be ruled out. Macrophages produce supernatant factor(s) in the course of phagocytosis which inhibit the motility of polymorphonuclear leukocytes. The active component of supernatant seems to be PG, since its production can be blocked by indomethacin. These data indicate that prostaglandins may have different sites of attack in the local regulation of leukocyte motility.

Agar microdroplet assay for delayed hypersensitivity to Legionella pneumophila serogroup 1.

An agarose microdroplet technique was utilized to assess the cellular immunity of guinea pig lymphoid cells to Legionella pneumophila antigen in vitro. Both direct and indirect migration inhibition procedures were shown to be capable of detecting sensitization of guinea pigs to L. pneumophila antigens. Animals injected with adjuvant alone or unrelated antigens did not yield spleen cells responsive to L. pneumophila, indicating the specificity of the response. Migration inhibition factor induction by Legionella antigen in vitro correlated well with skin test responses in vivo. The positive reaction detected by migration inhibition occurred at times similar to that of skin reactivity but later than that of the earliest serum antibody titers. The assay appears to be useful for monitoring sensitization to Legionella and may be applicable to the study of cell-mediated immunity to this bacterium in infected individuals.

Leukocyte migration inhibition by Mu-MTV-enriched extracts in breast cancer patients

The direct leukocyte migration inhibition assay has been used by a number of investigtors who demonstrated that it reflects the delayed-type hypersensitivity response in vitro . In this study we used an agarose microdroplet technique adapted from the technique described by Harrington and Stastny in 1973, in order to test the response of breast cancer lymphocytes to Mu-MTV (murine mammary tumour virus). This technique allowed us to test 30 patients suffering from malignant breast tumour, 30 healthy controls, 9 non-malignant breast patients and 9 patients with tumours other than breast cancer (ORL localization). The leukocytes of 9 out of 30 (30 %) of the malignant breast cancer patients studied were significantly inhibited by at least 2 concentrations of the Mu-MTV-enriched antigenic extract (average migration index (MI)=0.57 for a 5 μg/ml concentration), while the average MI was 0.92 for the controls under the same conditions. There was no significant inhibition in the non-malignant breast patients (average MI=0.91) or in the ORL patients (average MI=0.97) against Mu-MTV extracts. Among the 9 patients with a positive response, 5 were tested before any treatment; 4 had recurrence from 3 to 13 years following the primary tumour. The present study shows a cellular hypersensitivity response of breast cancer human lymphocytes against one or several antigens located in the murine virus extract. Le test d'inhibition de la migration des leucocytes (LMIA) a été décrit par de nombreux auteurs pour détecter in vitro une réponse d'hypersensibilité à médiation cellulaire chez l'homme. La technique de migration en micro-gouttes d'agarose nous a permis de comparer la réponse des lymphocytes de patientes atteintes de cancer du sein, vis-à-vis d'un extrait enrichi en Mu-MTV, avec celle de témoins sains. Neuf sur trente (30 %) des malades ont répondu positivement au Mu-MTV, alors que les 30 sujets témoins testés sont négatifs. Parallèlement, les 9 malades atteintes de tumeur bénigne du sein et les 9 malades ayant un cancer ORL sont négatives. Ces résultats montrent que 30 % des malades ayant un cancer du sein ont été préalablement sensibilisées à un ou plusieurs antigènes présent dans l'extrait viral murin.

Correlation between agarose microdroplet and capillary tube procedures as assays for migration inhibition of target cells

We have compared the capillary tube assay for migration inhibition studies with our modification of the agarose microdroplet technique, using several sources of factors with inhibitory activity (lymphokines, bacterial factors) and a variety of cell types (inflammatory exudated cells, tumor cells). In all circumstances both procedures gave quantively similar results, and high statistical correlation was found. These results suggest that the two procedures are measuring similar properties, and in any case may be used interchangeably as assays.