Neutral Red Solution Research Articles

In vitro and clinical evaluation of specific dentifrices for complete denture hygiene

To study the physical properties of two experimental dentifrices for complete denture hygiene, their effect on denture biofilm removal and antimicrobial properties by means of a clinical trial. The experimental dentifrices comprised two compositions. One was based on the addition of 1% chloramine T (D1) and the other on the presence of 0.01% fluorosurfactant (D2). Measurements of density, pH, consistency, rheological features and abrasiveness were conducted. Sixty complete denture wearers were randomly assigned to three groups and were instructed to brush their dentures with a specific toothbrush: (1) Water (control); (2) D1; or (3) D2. Each method was used for 21 days. Denture biofilm was disclosed by a 1% neutral red solution and quantified by means of digital photos taken from the internal surface. Microbiological assessment was conducted to quantify Candida sp. and mutans streptococci. Data were evaluated by one-way anova and Tukey HSD, or Kruskal-Wallis (alpha = 0.05). Both dentifrices decreased biofilm coverage when compared with the control group. D1 was the most efficacious treatment to reduce mutans streptococci, whereas D2 showed an intermediate outcome (ANOVA, p < 0.040). No treatment influenced Candida albicans or non-albicans species (Kruskal-Wallis, p = 0.163 and 0.746, respectively). It can be concluded that brushing complete dentures with the experimental dentifrices tested could be effective for the removal of denture biofilm.

Effects of mechanical and chemical methods on denture biofilm accumulation

The aim of this study was to quantify biofilm on the internal surface of upper complete dentures following six possible cleansing methods. Thirty-six edentulous subjects were submitted to a time-series trial and dentures were cleansed according to six methods: (i) rinsing with water; (ii) soaking in an alkaline peroxide solution (Bonyplus); (iii) brushing with dentifrice (Dentu-Creme) and soft Johnson and Johnson's toothbrush; (iv) combination between soaking and brushing according to methods 2 and 3; (v) brushing with dentifrice (Dentu-Creme) and soft Oral B toothbrush; (vi) combination between soaking and brushing according to methods 2 and 5. Each method was randomly used throughout 21 days. Denture biofilm was disclosed by 1% neutral red solution and quantified by means of digital photos taken from the internal surface. The six methods presented significant differences in percentage of biofilm coverage (repeated measures anova, P < 0.0001). Method 1 showed the highest values, 2 was intermediate and other results were the lowest. The most efficacious approach was 6. Biofilm tended to accumulate predominantly over specific zones of the denture base, but this pattern did not change regardless of the method employed. It can be concluded that brushing alone was more effective than the chemical method employed. The best results were obtained by a combination of methods.

Distribution of biofilm on internal and external surfaces of upper complete dentures: the effect of hygiene instruction

The purpose of this study was to evaluate biofilm distribution over internal and external surfaces of upper complete dentures. It was also aimed at assessing the effect of oral hygiene instructions before and after home use of a disclosing solution. The sample consisted of 29 complete denture wearers whose upper prostheses were evaluated. Surface biofilm was disclosed by means of a 1% neutral red solution and quantified with regard to internal and external surfaces. Oral hygiene information was provided on an individual basis. During the second stage, an amount of disclosing solution was given for domestic use. Internal and external surfaces presented a similar amount of biofilm, which was concentrated over the area of the posterior teeth area, palatal rugae and the internal vestibular incline of the distobuccal flange. This pattern was maintained during the study. However, overall amounts were reduced following denture hygiene information. The use of disclosing solution by subjects at home resulted in a further reduction. It was concluded that biofilm deposits were similar over assessed surfaces, regardless of the type of procedure but irregular areas presented greater amounts. Oral health instruction was effective in reducing the biofilm, in particular when associated with home use of a disclosing agent.

Immersion in Neutral Red Solution as a Mass-Marking Technique to Study the Movement of the Amphipod Corophium Volutator

Abstract We evaluated the usefulness of immersion in neutral red solution as a marking technique for studies of movement of the amphipod Corophium volutator. Amphipods were immersed for 20 minutes in solutions of neutral red at different concentrations (25, 50 and 100 mg L−1). Amphipods incorporated dye at all concentrations, and the hepatopancreas remained distinctly stained red for at least 7 days. No increase in mortality was detected at any concentration when compared to a control treatment (0 mg L−1). In a separate field experiment, staining did not significantly affect tendency of C. volutator to move. Overall, immersion in neutral red seems to be an appropriate technique to rapidly mark large numbers of C. volutator and is suitable for short-term mark-recapture experiments. This technique may also apply to other small-sized crustacean species with relatively transparent exoskeletons.

Testosterone and Nandrolone Sensitization of Brain Anteroventral Area of Third Ventricle to Hypertonic NaCl-Induced Sympathetic Response

Androgenic steroids increase atherogenesis, thrombogenicity and endothelial dysfunction when administered in high doses, however their effects on NaCl sensitivity of the brain anteroventral area of the third ventricle (ΔV3V) have not been explored. Sprague-Dawley male rats were anesthetized with sodium pentobarbital (40 mg/kg) and the femoral intra-arterial blood pressure and heart rate monitored through a strain-gauge blood pressure transducer and tachograph. ΔV3V microinjections of (2 µl) 1.5 mol/l NaCl solution were done according to brain coordinates: AP = 7.0 mm, L = 1.0 mm, D = 7.5 mm through a 0.2-mm diameter stainless steel needle. The injection site was verified with 1.0 µl neutral red solution. Basal systolic blood pressure increased 37.6 and 39.6 mm Hg after testosterone (1 mg/kg/day for 20 days) and nandrolone (1 mg/kg/day for 20 days) treatment respectively; diastolic blood pressure also increased upon testosterone and nandrolone treatment in 36.4 and 53.1 mm Hg, respectively; basal heart rate did not change. Vasopressor response to 1.5 mol/l NaCl ΔV3V microinjection was higher in testosterone-treated rats; systolic blood pressure increased 56.0 vs. 28.3 control mm Hg; diastolic blood pressure increased 54.0 vs. 25 control mm Hg. This hypertensive response was 29% longer lasting in testosterone compared to vehicle-treated rats. The same pattern of ΔV3V sensitization to hypertonic NaCl was observed in nandrolone-treated rats. Blood lipid profile changed to a proatherogenic fashion upon testosterone and nandrolone long-term treatment; the plasma-free testosterone concentration increased from 4.9 ± 0.9 to 36.0 ±7.1 pg/ml with the same testosterone treatment schedule. In conclusion, long-term androgenic steroid treatment sensitizes the brain ΔV3V region to hypertonic NaCl which in turn conducts into a sympathetic vasopressor and heart rate-stimulating action.

Evaluation of in vitro endocytosis and antibody synthesis by rainbow trout head kidney cells treated with bovine lactoferrin

Bovine lactoferrin (LF) was evaluated for its capacity to modulate the in vitro endocytosis (phagocytosis and pinocytosis) and antibody synthesis by head kidney cells of rainbow trout Oncorhynchus mykiss. Phagocytic activity and phagocytic index of head kidney macrophages, determined by measurement of ingested yeast, were influenced by bovine LF starting from the LF concentration of 1 and 0·1 μg ml−1, respectively. Endocytosis, determined by the evaluation of droplet uptake of neutral red dye solution, was significantly enhanced by 10 μg ml−1 of LF. In contrast, antibody synthesis by head kidney cells, evaluated by immunoenzymatic assay, from fish immunized against human‐γ‐globulins (HGG)in vivo was not affected by bovine LF. Although these results showed that bovine LF had no effect on specific immunoglobulin production in vitro, an enhancement of the acquired immune response may be assumed in LF‐treated fish in vivo, as observed in higher vertebrates.

A method for the rapid recognition of nulliparous and parous females of haematophagous Diptera

AbstractBased on the fact that in haematophagous Diptera, the basal bodies, groups of six to nine specialized epithelial cells in the calyx wall within the ovariolar sheath, become granular after ovulation, a method for rapidly determining parity of the females has been developed. After supravitally staining intact ovaries with fresh neutral red solution in physiological saline (1:3000–1:5000) for one to three minutes, granular basal bodies in parous females can be clearly recognized under a stereo-microscope or a compound microscope with a raised condensor. The advantages of the method are its speed, accuracy and simplicity.

Neutral red staining for the assessment of acute outcome in rat focal cerebral ischemia models.

Neutral red staining was evaluated as an acute outcome assessment method in rat models of cerebral ischemia by comparison with histological infarction volume. Fischer 344 rats (n = 48) were used in three different models of middle cerebral artery (MCA) occlusion: proximal MCA occlusion (n = 16), distal MCA occlusion followed by ipsilateral common carotid artery (CCA) occlusion (distal MCA/CCA occlusion, n = 15), and MCA occlusion with an intravascularly introduced 4-0 nylon suture (intravascular MCA occlusion, n = 17). At 1 hour, 2 hours, and 4 hours after MCA occlusion, animals were injected with 2.5 ml of 4% neutral red solution via the femoral vein, and then sacrificed. Proximal MCA occlusion caused a neutral red defect volume in the cortex which correlated well with histological infarction volume at 4 hours (r = 0.88, p < 0.05), and in the caudate which correlated well with infarction volume at 4 hours (r = 0.94, p < 0.01). Distal MCA/CCA occlusion caused a neutral red defect volume in the cortex lager than the histological infarction volume (4 hrs: 88.6 +/- 11.8 vs. 74.3 +/- 17.4 mm3, p < 0.05) but closely correlated with the infarction volume at 4 hours (r = 0.81, p < 0.05). Intravascular MCA occlusion caused a neutral red defect volume in only two of 17 animals after 1-4 hours, which correlated well with the absence of histological evidence of infarction. Neutral red staining is a simple method for assessing the acute outcome of focal cerebral ischemia as early as 4 hours after the onset, in an appropriate model of cerebral ischemia.

A quantitative structure-activity relationship for the effect of alcohols on neutral red retention by the marine macroalga Enteromorpha intestinalis

The effect of alcohols on the retention of neutral red, a vital stain, was investigated for the marine macroalga Enteromorpha intestinalis. The algae were incubated for 24 hrs in a series of non-specific narcotic alcohols, and subsequently exposed to a neutral red solution for 3 hrs. On removal, the stain was extracted into a solvent and the resultant absorbance measured spectrophotometrically. EC 50 values for the inhibition of neutral red uptake were used to establish a quantitative structure-activity relationship (QSAR). This technique is reproducible and sensitive enough for laboratory testing. Comparisons are made between this assay and others.

The fluctuation and distribution of the population density and fish movement of rose bitterling in shin tone river.

From the analysis of fish catch data and mark-recapture experiments the population density and movement of rose bitterling Rhodeus ocellatus ocellatus was determined. The mean of the catch per trap was considered as the index of the population density. It was found that the population density was high in summer and very low in winter with a peak in late summer. In the daily mark-recapture experiments using Neutral Red and Bismark Brown solution, about 90% of the recapture numbers in every month were found within 30-40m from the released points. A very few of the fish managed to cover a distance of 100m. In other mark-recapture experiments using fluorescent pigment, in a five month period more than 90% of the recaptures were made near their point of release, having covered only a distance of 200-700m. From these, it was concluded that only limited and localized fish movement occurred during the daily or the five month interval of the experimental period. Fish abundance estimates based on the daily mark-recapture date of each month using the Petersen method were calculated as 13, 000-35, 300 fish for a 36m river shoreline for August and September when the fish catch was highest.

Les corps multivésiculaires de l’œuf de Barnea candida (Mollusque Bivalve) étudiés au microscope électronique

ABSTRACT Multivesicular bodies of the egg o/Barnea candida studied with the electron microscope Fertilized eggs, stained for 5 min with 1/5000 neutral red solution, when examined an hour later (at the stage of the pronuclei) show all the stain con-centrated in vacuoles having a diameter from 4 to 5 μ, crowded around the pronuclei (cf. Pasteels &amp; Mulnard, 1963). After examination with the electron microscope, it appears that these vacuoles are the result of an enlargement of the multivesicular bodies (m.v.b) deriving from the transformation of the yolk platelets. Acid phosphatase activity (after an incubation of 1 h) has been detected in e.m. sections; this activity appears selectively in very limited areas of some yolk platelets, on the m.v.b. and at the top of the cortical microvilli. These observations allow us to confirm the previous hypothesis of Pasteels &amp; Mulnard (1963) : that the a meta-granules are some of the yolk platelets while the β meta-granules are the m.v.b. deriving from those platelets. The pictures of the accumulation of neutral red into the m.v.b. are identical with those which have been published by Robbins, Marcus &amp; Gonatas (1964), who stained Hela cells with acridine orange under the same experimental conditions. The m.v.b. of the egg, although being a transitory phase of the transformation of the yolk, have thus the same properties as the m.v.b. of some non-embryonic cells. It might be concluded that the ‘vacuome’ of Parat (1928) is constituted by the m.v.b. The existence of an acid phosphatase activity on top of the cortical micro-villi permits one to presume that this activity is preliminary to an excretion of some substances from the egg into sea-water.

界面活性剤の定量 (第4報)

By the use of the properties of Neutral Red to react with sulfate-type and sulfonate-type anionic surface active agents to forma complex compound sparingly soluble in water but easily soluble in organic solvents, various conditions were examined for the determination of sodium laurylsulfate. The method thereby established was as follows: A sample solution containing 5-100γ/cc. of sodium laurylsulfate, 1cc. of buffer solution (pH 5), and 2cc. of 0.01M Neutral Red solution, measured accurately, are placed in a glass-stoppered test tube and shaken for about 1 minute. To this mixture, 10cc. of dichloroethylene is added, the mixture is shaken for 2 minutes, and centrifuged. The supernatant is filtered through a cotton plug and absorbance of the filtrate is measured at 530mμ. A blank test is carried out with the same quantity of the same reagents, using 1cc. of distilled water in place of the sample solution. This method can be used to a certain extent in the presence of potassium stearate and nonionic surface active agents, and the presence of sodium sulfate does not interfere in this reaction. If 10cc. of the sample solution is used, this method can be applied to solutions of 1/10 the concentration. The accuracy of this method is below 1%.

Survival of Woody Plants at Extremely Low Temperatures

JENSEN1 has also claimed that the ability to plasmolyse in onion cells is not a reliable index to their viability, because he observed some abnormal cells in which vacuoles were normally stained by neutral red solution and tonoplasts still retained their permeability, having the cytoplasmic layers torn outside the tonoplasts. In a previous report3 I stated that such abnormal cells have not yet been observed during several years study in the parenchyma cells of the cortex in woody plants, but some parenchyma cells are found in which the ectoplasts still retain their semi-permeability though their tonoplasts are torn and their cytoplasmic layers are mixed with vacuolar content (see plate 1,2 ref. 2) However, such abnormal cells are easily distinguishable from the normal by their appearance. Thus, in the parenchyma cells in twigs of woody plants, unlike the case of onion cells, it may be possible to determine the relative degree of viability in parenchyma cells, upon the basis of both their vital staining with neutral red solution and the appearance of plasmolysed cells, at least in one and the same series of experiments. However, judging3 of the intactness of twig as a whole cannot be made only on the basis of plasmolysis test in parenchyma cells just subsequent to, or even after, many days of thawing, because inner cortex, pith ray, and pith periclinal tissue are less resistant to freezing than parenchyma cells of cortex. Accordingly, to demonstrate the intactness of a treated twig as a whole, it was planted in moist sand and its capacity tested to continue normal development at least for three months after planting, as mentioned in my reports4. Even in the tetrazolium5 test used by Parker, it may be said that judging the intactness in plants means only determination of a relative value of viability of certain tissues in twig or leaf without testing the whole of it as is done by the plasmolysis method.

Acceleration of the cleavage of sea urchin eggs by vital staining with neutral red

1. 1. Unfertilized sea urchin eggs were stained with neutral red sea water (1–8 drops of 0.2 per cent neutral red solution plus 10 cc of ordinary sea water) for 5 and 30 minutes respectively, and then transferred in ordinary sea water. These eggs were fertilized after having been left in the sea water for 30 minutes or more in the case of the Temnopleurus and Anthocidaris eggs and for 90 minutes or more in the case of the Pseudocentrotus eggs. The first cleavage in such stained eggs takes place much earlier than in the controls. 2. 2. The acceleration of cleavage was observed only in the first cleavage cycle and is due to a shortening of the time of appearance of the streak stage. 3. 3. Even in stained centrifugal egg fragments, which lack the egg pronucleus, the acceleration of cleavage was induced. 4. 4. The cleavage was accelerated only in the eggs in which the neutral red-stained vacuoles appeared before fertilization.

The frost-hardiness of roses. I

1. With the deceleration of the process of grow-th, the cane of rose becomes frost-hardy to some degree without being subjected to low temperature and then can be hardened further when they are subjected to low temperature. On the other hand, the growing cane is neither frost-hardy nor able to increase its frost-hardiness, even if it is subjected for ten days to 0°C. It is, therefore, very likely that in canes of the rose, the frost-hardiness as well as the abilty to be effectively hardened by ar-tificial chilling is closely associated with their stage of development. A variety that increase earlier its frost-hardiness in early fall has greater winter frost-hardiness than others. 2. The minimum temperature at which the canes of rose varieties are able to survive after 24 hours of freezing in winter are as follows: R. laevigata: -10°_??_-12°C, H. T., Floribunda, R. kordesii: -14°_??_16°C, H. P., Sub. Zero: -17_??_-18°C, Dorothy Perkins (Rambler): -20°C, R. multiflora, R. wichuraiana, R. setigera: -22°_??_-24°C and R. rugosa, R. pendulina: -27°_??_-28°C (Table 1). 3. In both natural and artificial frost-hardening of the parenchyma cells in the cortex of the rose, the increase in frost-hardiness of parenchyma cells is intimately proportional to that in their osmotic concentration (Table 2, Fig.2). 4. The canes of R. pendulina, and R. rugosa were immersed in liquid oxygen for 24 hours after pre-freezing for 16 hours at -30°C in order to draw from the cell interior almost all of the easily freez-able water by sufficient extracellular freezing. After having been thawed, they were planted in moist sand to test the capacity for development in green-house. The canes so treated put forth buds (Fig. 3); the parenchyma cells of their cortex were normally stained by neutral red solution and retain-ed their plasmolysis capacity (Fig. 4), but gradual-ly th canes withered because their inner cortex, pith-ray and pith periclinal tissue are less resistant to pre-freezing at -30°C than the parenchyma cells of cortex and buds.

簡易骨髄組織培養法に関する研究

With the use of the simple bone-marrow tissue culture, the method devised in our laboratory, in the medium composed of serum and vitamin B12, the author studied the neutral red vital staining of neutrophils in the bone marrow of both normal persons and patients with various blood diseases. These results were compared with those obtained by the conventional method using the medium composed of plasma mixed with heparin and chick embryo juice; and the author arrived at the following conclusions:1. The average stain of mature neutrophils in the case of normal persons reaches the maximum of 1.12 within 4 hours after the addition of neutral red solution, fading gradually thereafter.2. In the case of leukemia mature neutrophils in the bone marrow are stained more deeply at an early stage as compared with those of normal persons; and in the acute leukemia they fade at an early stage, and in the chronic leukemia they fade more slowly than those of acute leukemia.3. In the case of hypoplastic anemia mature neutrophils in the bone marrow are stained deeper and earlier than those is normal persons, and also they fade more quickly.4. In the case of agranulocytosis mature neutrophils are stained more lightly than those in normal persons.5. In the case of essential hypochromic anemia mature neutrophils in the bone marrow are stained more deeply and earlier than those in normal persons, but fading more slowly. In the case of pernicious anemia these neutrophils are stained more deeply both before and after the treatment than those in normal persons, but as for the fading before and after treatment, the former is slightly faster than the latter.6. These results indicate that, although this method is slightly inferior to the conventional method from the standpoint of neutral red vital staining, it is rather a superior method for clinical application because of its simplicity in manipulation the same as in the study of the carbon-particle phagocytosis.

The Use of Neutral Red Solution for the Comparative Study of Filtration Rates of Lamellibranchs

Journal Article The Use of Neutral Red Solution for the Comparative Study of Filtration Rates of Lamellibranchs Get access H. A. Cole, H. A. Cole Fisheries LaboratoryBurnham-on-Crouch Search for other works by this author on: Oxford Academic Google Scholar B. T. Hepper B. T. Hepper Fisheries LaboratoryBurnham-on-Crouch Search for other works by this author on: Oxford Academic Google Scholar ICES Journal of Marine Science, Volume 20, Issue 2, December 1954, Pages 197–203, https://doi.org/10.1093/icesjms/20.2.197 Published: 01 December 1954

Excretory function of the skin in the squid.

SummaryThe skin of the squid functions as an organ of excretion. This is proven by feeding squids neutral red solution. The neutral red is eliminated by the skin in the form of dark red droplets, heavier than sea water and not soluble in it.