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PubMedDate not supplied

The effects of ivermectin used in combination with other known antiparasitic drugs on adult Onchocerca gutturosa and O. volvulus in vitro.

The effects of ivermectin at a concentration of 3.13 x 10(-6) M used in combination with other antiparasitic drugs on the viability of adult Onchocerca in vitro were assessed using MTT colorimetry and worm motility levels. When ivermectin was used against male O. gutturosa over a 7 d period in combination with suramin (5 x 10(-5) M), CGP 6140 (3.13 x 10(-6) M), CGP 20376 (1.95 x 10(-7) M), mefloquine (3.13 x 10(-6) M), levamisole (3.13 x 10(-6) M), mebendazole (5 x 10(-5) M), flubendazole (5 x 10(-5) M) and albendazole (5 x 10(-5) M), there was either no increased effect or only a marginally increased effect on motility levels when compared with the use of ivermectin alone. MTT colorimetry revealed that in most cases there was a cumulative effect of the 2 drugs used in combination but not a synergistic effect. In a trial extended to 26 d it was demonstrated that the combination of ivermectin and suramin did not produce a greater inhibition of motility than ivermectin alone. Using female O. volvulus, the activity of ivermectin, CGP 6140 and the 2 drugs combined was examined. The motility of all 3 groups exposed to drug(s) was suppressed by 24 h compared with controls. MTT colorimetry performed on day 7, using the pre-weighed anterior end of each worm, illustrated that ivermectin alone produced a 43.4% inhibition of formazan formation compared with controls, CGP 6140 alone produced 50.6% inhibition, while the drug combination produced a 72% inhibition, equivalent to the heat-killed control.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Potency assessment of topical corticoids in the vasoconstrictor assay and on tuberculin-induced inflammation.

The topical anti-inflammatory activity of potent and very potent corticoids was studied in normal and inflamed skin using the vasoconstriction assay and tuberculin-induced inflammation in four double-blind intraindividual comparison trials. Instrumental techniques in addition to visual scores and several time points were applied to get better insight into the reliability of the models and the sensitivity of the different variables. Beta-methasone-17-valerate and two concentrations of prednicarbate were used as potent corticoids, clobetasol-17-propionate, betamethasone-17,21-dipropionate and different biopharmaceutical forms of desoximetasone (DOM) as very potent corticoids. Visual scores, the reactive skin hyperemia after arterial occlusion and skin colorimetry were used to quantify vasoconstriction; erythema scores, surface area of infiltration and changes in skin colorimetry, skin blood flow and skin temperature for the tuberculin reaction. The time courses of blanching (n = 20) and of the tuberculin reaction (n = 10) were described by orthogonal polynomials and the coefficients were statistically analyzed by nonparametric tests, the discriminative variables in tuberculin inflammation in addition by the parametric multiple analysis of variance. Important differences in the release rates of corticoids demand several assessment times and not just one as often used. The potency ranking may otherwise be misleading. In general, ointments released corticoids slowlier than the cream which in turn liberated slowlier than the gels. The DOM gel declined rapidly after an apparent peak at 5.5 h in terms of its blanching effect, but was nevertheless comparable after once-daily application to other very potent corticoids in its activity against delayed-type inflammation. Such differences may explain discrepancies found for some corticoid preparations between their blanching response and clinical efficacy. The more potent a corticoid the more the erythema is reduced, the less pronounced the cell infiltration and the more delayed the peak seems from 24 to 48 h in the tuberculin reaction. The inflammatory response is diminished in the following manner: very potent greater than potent corticoids; erythema greater than infiltration. Visual scores were the most reliable parameters in normal and inflamed skin and they correlated well with skin colorimetry which shows greater variability. Reactive hyperemia after arterial occlusion gave poor results in terms of ranking in the vasoconstriction assay as did resting skin blood flow in inflamed skin. Changes in the temperature of inflamed skin are sensitive enough to discriminate the active drugs from the controls, but have a somewhat different time course, reflecting perhaps a higher impact of the amount of mediator release in the early phase relative to the cell invasion in the later phase.

Administration, Topical↗

PubMed2004

[Morphological observation on NK/LAK cell-mediated lysis of human oral carcinoma cells].

OBJECTIVE: To understand the relation between cytotoxic activity of immunologic effector cells and multidrug resistance of the tumor cells. METHODS: Continuous observation of the morphological changes and MTT colorimetry were employed to evaluate the cytotoxic activity of lymphokine-activated killer (LAK) cells and natural killer (NK) cells against multidrug-resistant (MDR) human oral carcinoma cell line-KBV200 (before and after reversal of MDR) and parental drug-sensitive cell line KB. The morphologic changes of LAK cells and the 3 target cell lines were observed continuously under inverted microscope 3 h after co-culture of LAK cells with one of three target cell lines respectively. The lysis rates of three tumor cell lines in response to co-culture with LAK or NK cells were determined using MTT colorimetry. RESULTS: In comparison with the parental drug-sensitive cell line KB, both KBV200 and its reserved cell line by verapamil (KBVV) showed earlier adherence and greater number of cells lysed by LAK. In MTT colorimetry assay, the cytotoxicity of both LAK and NK cells against the 3 cell lines was associated with the effector-to-target (E/T) cell ratio; the lysis rates of KBV200 and reversed KBV200 cells by verapamil in response to LAK and NK cells were higher than that of KB cells (P<0.05), but KBV200 and KBVV did not significantly differ (P>0.05). At the same E/T ratio, LAK cells possessed stronger cytotoxicity than NK cells against all the tumor cell lines (P<0.05). CONCLUSIONS: Immunologic effector cells possess strong cytotoxic activity against multidrug-resistant cell line KBV200. Modulation of MDR does not decrease the cytotoxic activity of the immunologic effector cells. The results of this study suggest that adoptive cell immunotherapy with immunologic effector cells may be of value in controlling the progress of MDR tumors.

Cell Line, Tumor↗

PubMed1994

MTT-assay and neutral red release (NRR)-assay: relative role in the prediction of the irritancy potential of surfactants.

A comparative study on the in vitro and in vivo irritancy of anionic, amphoteric and non-ionic surfactants was performed. In vitro ED50 values of the surfactants were determined by two cytotoxicity assays, the dimethylthiazoldiphenyltetrazoliumbromide (MTT) assay and the neutral red release (NRR) assay on serum-free cultured human foreskin keratinocytes. In vivo human irritancy data were obtained by a 24 hour occlusive patch test in volunteers and the irritant skin response quantified by visual scoring, evaporimetry and colorimetry. A close relationship between the evaluation methods of the patch test was observed (r = 0.92 to r = 0.96), confirming that the 'bioengineering' methods, such as evaporimetry and colorimetry are suitable for measuring skin irritation. For six surfactants evaluated we found a good correlation (r = 0.91) between the ED50 values of the MTT assay and the in vivo irritancy data. The NRR assay yielded less satisfactory correlation coefficients with regard to MTT assay (r = 0.42) and in vivo irritancy data (r = 0.46). This can be mainly attributed to a misinterpretation of the amphoteric and non-ionic surfactants by the NRR assay. While the NRR assay may better evaluate the anionic surfactants, the MTT assay seems to be more suitable when testing a broader range of chemically diverse surfactants. Limitations of cell culture systems are noted, although the potential usefulness of cultured human skin cells for skin irritancy testing has been clearly demonstrated.

Adult↗

PubMed1997

Para-aminobenzoic acid used as a marker for completeness of 24 hour urine: assessment of control limits for a specific HPLC method.

OBJECTIVE AND DESIGN: The study comprised three protocols. Protocol 1 compared a HPLC method with the commonly employed colorimetric diazocoupling method. Protocol 2 examined, if the last dosage of p-aminobenzoic acid (PABA) could be advanced in the old to allow for a delayed age-dependent urinary excretion of PABA. Protocol 3 established limits for recovery of PABA in 24 h urine applying the HPLC method. SUBJECTS AND SETTING: A total of 151 healthy volunteers participated in the study of which 140 were accepted. In protocol 1: 37 subjects aged 20-78 y were included. All subjects took PABA as recommended (80 mg orally at 08.00, 12.00 and 18.00 h). Protocol 2: compared urinary PABA excretion in two groups of 80 y old subjects who had their last PABA dosage administered at 15.00 h (n = 16) and at 18.00 h (n = 31), respectively. Protocol 3: comprised 56 subjects aged 20-80 y. In the younger age group (20-59 y; n = 34) PABA was taken as recommended, whereas in the older age group (60-80 y; n = 22) the last PABA dosage was advanced three hours. RESULTS: Protocol 1: HPLC gave significantly lower PABA recovery results compared to colorimetry, the difference between methods being 23.9 +/- 8.5 mg/24 h (P < 0.001). Protocol 2: higher PABA recoveries were demonstrated with the advanced dosage schedule compared to the recommended schedule (208 +/- 14 mg/24 h vs 181 +/- 22 mg/24 h; P < 0.001). Protocol 3: PABA recovery with HPLC was 211 +/- 12 mg/24 h, and the lower limit comprising 95% of subjects was 187 mg/24 h. Similar PABA recoveries were demonstrated in the younger subjects and the older subjects (211 +/- 11 mg/24 h vs 211 +/- 13 mg/24 h; NS). CONCLUSION: An advanced dosage schedule for PABA in the aged is recommended. Because of lower recoveries with HPLC, the low limit for recovered PABA in a complete 24 h urine differs from the limit based on colorimetry. This study found a limit of 187 mg/24 h corresponding to the lower 95% confidence limit for a single subject.

4-Aminobenzoic Acid↗

PubMed2006

Approaches to document the efficacy and safety of microdermabrasion procedure.

BACKGROUND: Microdermabrasion is a popular cosmetic procedure for skin rejuvenation, which is achieved by mechanical abrasion of the skin at a superficial level. OBJECTIVE: The objective was to study the efficacy of microdermabrasion in photoaging and to investigate the compatibility of a cleanser and a lotion with microdermabrasion. METHODS: Sixteen women underwent microdermabrasion to the face once a week for a total of six treatments. Subjects were also given a personal skin care regimen (cleanser and lotion). Colorimetry values as well as investigator and patients ratings for safety and efficacy were analyzed at various time points and compared to baseline. RESULTS: There were no significant changes in safety and tolerance variables throughout the study. Clinical efficacy variables (fine wrinkles, dullness, pigmentation, and large pores) significantly improved by the third treatment, with further improvement by the end of the study (six treatments). Subjects perceived improvement in facial photoaging variables. Colorimetry showed increased brightness and decreased yellowness of target skin sites on the face throughout the study. CONCLUSION: Multiple microdermabrasions were effective in significantly improving various facial photoaging variables. The personal skin care regimen used was well tolerated by the subjects.

Adult↗

PubMed2000

Assessment of iron absorption from ferric trimaltol.

Therapeutic iron compounds have limited absorption and often have side-effects, which limits patient compliance. Iron trimaltol is a novel, stable complex, formed between ferric iron (Fe3+) and maltol (3-hydroxy-2-methyl-4-pyrone), and is effective in the treatment of iron deficiency anaemia with few side-effects. However, the kinetics of iron absorption from ferric trimaltol and the reliability of normal colorimetric analysis in detecting iron absorbed from this complex have not been established. We measured increases in serum iron levels in 12 volunteers following oral challenge with four different pharmaceutical formulations of ferric trimaltol in a double-blind, cross-over, randomized study. The conventional colorimetric method for detecting serum iron was compared with thermal analyses after trichloroacetic acid (TCA) treatment of serum. Measurements of serum iron levels by TCA treatment and thermal analysis closely agreed with measurements by colorimetry. For all formulations, serum iron levels peaked at 90 min with a plateau of at least 5 h [mean (standard deviation) peak absorption 8.3% (6.3%) of ingested dose, n=48]. Absorption of iron, based on peak serum values or area under the serum curve, was not different for the four formulations (n=12 each) and correlated with the individual's iron status, as assessed by serum ferritin values (r = -0.6; P < 0.001). Normal colorimetry is suitable for analysis of serum iron levels following ingestion of ferric trimaltol. There is rapid and sustained absorption of iron from ferric trimaltol and, as with ferrous iron, uptake appears to be controlled through normal mechanisms of iron acquisition that depend upon body iron stores.

Adult↗

PubMed2001

[The influence of somatostatin 14 on the proliferation of human retroocular fibroblasts].

OBJECTIVE: To elucidate the possible mechanism of Somatostatin 14 in the treatment of Graves' ophthalmopathy, thus providing laboratory data with the intent to underpin therapeutic developments. METHODS: The human retro-ocular fibroblasts (HROFb) was cultured and MTT colorimetry assay was used to determine the proliferation of HROFb. RESULTS: MTT colorimetry assay could precisely reflect the proliferation of HROFb. The absorbance was directly proportional to the numbers of the cells (r = 0.996, P < 0.001). Somatostatin 14 could enhance the cell proliferation percentage at lower levels (< 25 nmol/L) and inhibit that at higher levels (> 25 nmol/L). The cell proliferation correlated positively to Somatostatin 14 levels significantly (r = -0.9054, P < 0.001). CONCLUSION: Somatostatin 14 has a dual effect on HROFb.

Cell Division↗

PubMed2005

[Preparation and quality control of low molecular weight chitosan].

OBJECTIVE: To prepare the low molecular weight chitosan (LMWC) and establish the method for quality control. METHOD: Use enzymatic degradation to prepare LMWC with chitosan, and separate by ultrafiltration; the molecular weight and purity were determined by gel permeation chromatography (GPC) and colorimetry respectively. RESULT: LMWC was prepared by control the hours of enzymatic degradation and ultrafiltered through filter with cutoff molecular of 10K Dalton and 50 K dalton; the average molecular weight was 20 K dalton and the purity was (96.60 +/- 1.56)%. CONCLUSION: The condition of enzymatic degradation is geniality and easy to control, LMWCs with different molecular weight can separate by ultrafiltration efficiently; the quality of LMWC can control with gel permeation chromatography (GPC) and colorimetry.

Cellulase↗

PubMed1990

[The effect of sorbitol on the determination of keto amines using a colorimetric method].

The presence of sorbitol in a concentration 11 mg/ml in a sample reduces by 68 percent the values of fructose glycine measured by colorimetry with thiobarbituric acid. Such sorbitol concentration has no effect on furfural production and on 5-hydroxymethylfurfural reaction with thiobarbituric acid. Measurements of glycolyzed hemoglobin have demonstrated that sorbitol in concentration 11 mg/ml completely inhibits hydrolysis. This fact should be borne in mind when measuring blood glycosylated hemoglobin by colorimetry with thiobarbituric acid and exclude sorbitol from patients' rations before measurements.

Colorimetry↗

PubMedDate not supplied

Improved method for measurement of dietary fiber as non-starch polysaccharides in plant foods.

A method is described that allows rapid estimation of total, soluble, and insoluble dietary fiber as the non-starch polysaccharides (NSP) in plant foods. It is a modification of an earlier, more complex procedure. Starch is completely removed enzymatically, and NSP is measured as the sum of its constituent sugars released by acid hydrolysis. The sugars may, in turn, be measured by gas chromatography (GC), giving values for individual monosaccharides, or more rapidly by colorimetry. Both GC and colorimetry are suitable for routine measurement of total, soluble, and insoluble dietary fiber in cereals, fruits, and vegetables. Values obtained are not affected by food processing so the dietary fiber content of various processed foods and mixed diets can be calculated simply from knowing the amount in the raw materials. The additional information obtained by GC analysis is valuable in the interpretation of physiological studies and in epidemiology where disease is related to type and amount of dietary fiber.

Acetylation↗

PubMed1989

Effect of sodium bicarbonate infusions on ionized calcium and total calcium concentrations in serum of clinically normal cats.

The effects of sodium bicarbonate (0.5 mEq/kg of body weight, 1.0 mEq/kg, 2.0 mEq/kg, and 4.0 mEq/kg) on ionized and total calcium concentrations were determined in clinically normal cats. Also, serum pH, whole blood pH, and serum albumin, serum total protein, and serum phosphorus concentrations were measured. Intravenous administration of sodium bicarbonate to awake cats decreased serum ionized calcium and serum total calcium concentrations. All dosages of sodium bicarbonate were associated with significant decreases of serum ionized calcium concentration. This effect lasted for greater than 180 minutes when cats were given 2.0 mEq/kg or 4.0 mEq/kg. When cats were given 4 mEq of sodium bicarbonate/kg, serum ionized calcium concentration was significantly decreased, compared with that when cats were given lower doses, but only at 10 minutes after infusion. After sodium bicarbonate infusion, serum total calcium concentration, measured by ion-specific electrode and colorimetry, was lower than baseline values at most of the times evaluated. Decreases in serum ionized calcium and serum total calcium concentrations can be attributed only in part to an increase in serum or whole blood pH and to a decrease in serum protein concentration. Serum total calcium concentrations measured by ion-specific electrode and by colorimetry were positively correlated, but the variability was high. Only 44% of the variability in serum ionized calcium concentration could be predicted when serum total calcium, albumin, total protein, phosphorus, and bicarbonate concentrations and pH were considered.

Animals↗

PubMed1986

Liquid-chromatographic determination of 4-hydroxyproline in urine.

In this method for 4-hydroxyproline in urine, hydroxyproline is derivatized with 4-chloro-7-nitrobenzofurazan, with subsequent estimation by reversed-phase "high-performance" liquid chromatography. The ranges for excretion of free and total hydroxyproline while the subjects were ingesting unrestricted diets were 2-29 and 122-374 mumol/24 h (n = 21), respectively, with no significant sex-related difference. A comparison with results by colorimetry indicated no significant differences: mean (n = 18) concentrations (mumol/L) of hydroxyproline in urine were 180 (SD 149) by the present method, 163 (SD 166) by colorimetry. For protein hydrolysate the respective values were 5.9 (SD 2.7) and 6.7 (SD 2.9).

Chromatography, High Pressure Liquid↗

PubMedDate not supplied

[Determination of the iodine content in food products using the nitrite-rhodanide method].

The nitrite-rodanide method was suggested to determine the content of iodine in food. It was shown that this method, provided the exposure of the test solutions during colorimetry was appropriately chosen, enables the determination in an aliquot of 0.5 g of both low and high (2-600 microgram/100 ml) concentrations of iodine. The determination of high concentrations can be realized by an ordinary diluting of the solutions under colorimetry.

Animals↗

PubMed1998

[The use of electrophoretic methods for determining modified proteins in diabetic patients].

Modified proteins were determined by isoelectric focusing in borate-polyol system with subsequent colorimetry (micromethod) and electrophoresis of blood serum on paper with subsequent TCA-ethanol treatment. Increased levels of glycated hemoglobin and modified albumin and changed light absorbance of glycated albumin were detected. The levels of glycated hemoglobin assessed by the micromethod and colorimetry without calibration did not correlate.

Blood Protein Electrophoresis↗

PubMed1997

Sodium hypochlorite, bleaching agents, and the stratum corneum.

Interactions between bleaching agents containing sodium hypochlorite (NaOCl) and human stratum corneum are complex and not fully understood. The same applies when NaOCl is used as a war gas decontaminant. In this study data yielded by in vivo testing and an ex vivo bioassay are compared. Fifteen volunteers received patch tests of a neat proprietary NaOCl bleaching agent for 15, 30, 45, 60, and 90 min. No clinical reaction was seen. Reflectance colorimetry, transepidermal water loss (TEWL), and capacitance were measured for 72 hr after patch removal. Squamometry was also performed using D-Squames and colorimetry of the samples. In addition, the ex vivo corneoxenometry bioassay was conducted on various dilutions of the bleach. Data reveal that conductance and squamometry were more sensitive than TEWL to disclose the action of bleach upon the stratum corneum. Corneoxenometry proved to be a good predictive ex vivo bioassay, indicating the same information as the in vivo tests. Both squamometry and corneoxenometry appear valuable and complementary in assessing infraclinical damages of human skin by a NaOCl bleaching agent.

Adult↗

PubMed1983

Detection and determination of lipase (acylglycerol hydrolase) activity from various sources.

Methods for the detection and determination of lipases (acylglycerol hydrolases) and preparation of assays are reviewed including substrates, conditions and screening. Some newer methods for the determination of lipase activity are discussed. Several of these are: (a) titrimetry, (b) colorimetry of Cu soaps of free fatty acids (FFA), (c) colorimetry of chromophores in the acyl chain of FFA or in glycerol, (d) radioassay, (e) gas liquid chromatography, (f) enzymatic treatment of FFA and measurement of the resulting products, and (g) direct immunological determination of the lipase. Examples and sensitivities are given and advantages and disadvantages are described.

Chromatography, Gas↗

PubMed2005

Tumor necrosis factor-related apoptosis ligand induces apoptosis in prostate cancer PC-3M cell line.

To study the effect of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on PC-3M cell line, PC-3M cell line was incubated with gradient concentrations of TRAIL for 4--24 h. Annixin-V fluorescence staining and TUNEL method were employed to detect the apoptosis of PC-3M cells. The morphology of apoptotic PC-3M cells was observed by electron microscopy. The relationship between TRAIL concentrations and the percentage of apoptotic cells was evaluated by flow cytometry. The proliferation inhibitory ratio was calculated by using MTT colorimetry. Our results showed that apoptosis of PC-3M cells could be induced by treatment with TRAIL for at most 4 h. The results of flow cytometry and MTT colorimetry demonstrated a time- and concentration-dependent relationship between cell apoptosis rate and TRAIL concentration. It is concluded that apoptosis of PC-3M cells can be induced by TRAIL. Because of the selective killing effect of TRAIL on tumor cells, it may become a potential alternative for the treatment of advanced prostate cancer.

Apoptosis↗