Tear dynamics under scleral lenses

PurposeTo evaluate post-lens tear dynamics at two different time points during scleral lens wear in two cohorts with 10 neophytes each.MethodsAll subjects wore bilaterally scleral lenses for 5 h on 3 separate visits. Post-lens tear exchange was measured using Out-in method, which required 5 μL of 2% FITC-Dextran instilled on the bulbar conjunctiva during lens wear. Time taken to observe the first sign of fluorescence in post-lens tear reservoir was recorded with a stopwatch. Out-in measurements were collected at 5-hour post-lens insertion in Group 1 and compared with those obtained at 20 min of lens wear in Group 2. Tear dynamics under the lens was observed in Group 2 with fluorogram using a modified slit-lamp technique (Tan et al., 2018) to monitor post-lens fluorescence intensity and with high-resolution spectral domain optical coherence tomography (ENVISU 2300; Bioptigen Inc.) to measure post-lens tear thickness (PoLTT) over 5 h of lens wear.Results60% of subjects in Group 1 achieved Out-in times less than 5 min at 5-hour post-lens insertion, compared with 67% of subjects at 20-min lens wear (Tan et al., 2018). Using qualitative analysis on 60 series of data in Group 2 to compare the changes in fluorescence intensity and PoLTT with respect to lens-wearing time, 27% was due to lens settling, 13% was due to tear exchange and mixing while 60% indicated tear dynamics under scleral lenses was due to a combination of tear exchange, mixing, and lens settling.ConclusionTear flow into tear reservoir under a scleral lens on subjects with healthy cornea occurred at 20 min and 5 h after lens insertion. After 5 h of lens wear, roughly one third of the subjects had no tear flow into post-lens reservoir, as the observed decline in post-lens tear fluorescence was predominately due to lens settling.     

J. Cosmet. Sci., 59, 441–448 (September/October 2008)Simultaneous determination of heavy metals in cosmetic products

An extremely small amount of several heavy metals have been detected in cosmetic products as impurities, which can cause skin allergies through percutaneous adsorption on the skin. We present here a fast, accurate, and highly sensitive method for simultaneous determination of Pb²⁺, Fe²⁺, Cu²⁺, Ni²⁺, Zn²⁺, Co²⁺, Cd²⁺ and Mn²⁺ in coloring agents and cosmetic products, to be evaluated by ion chromatography. All of these metals are well separated through a bifunctional ion-exchange column (IonPac CS5A) and detected by post-column reaction and spectrophotometric detection. The calibration graphs are linear ( r ² > 0.999), in the range 0.1–1000 μg ml^-1. Detection limits for a 200-μl sample solution are at the μg L^-1 level, which is sufficient for judging whether the product is safe or not. The relative standard deviations (RSDs) of the retention time and the peak area are less than 0.21 and 1.24%, respectively. The recovery rates are 97–104%. The result shows that the proposed determination method is more sensitive, more accurate, and faster than current methods such as HPLC, ICP-MS and Flame-AAS. The new method was applied to analyse the amount of heavy metals contained in 22 cosmetic products and 11 coloring agents.     

糯麦粉对冷冻面团发酵流变特性和面包烘焙特性的影响

采用发酵流变测定仪和质构分析仪研究不同比例的糯麦粉对冷冻面团发酵流变学特性和面包烘焙特性的影响。结果表明：无论面团冷冻与否,随着糯麦比例增加,面团发展的最大高度(Hm)和持气率(R)逐渐下降,而气体释放曲线最大高度(H＇m)和CO2产气量(Vco2)在一定程度上增加。随着冻藏时间的延长,面团各种参数(Hm、H＇m、R等)逐渐降低,但是下降的幅度随糯麦粉添加量的增加而减小,如与冻藏7d相比,添加质量分数0%、10%、20%和30%的糯麦面团经冻藏60d后Hm分别下降了12.9%、9.6%、7.7%和7.5%,而R则分别下降了2.8%、2.1%、1.6%和1.7%。在冷冻贮藏过程中,面包品质虽有一定程度的下降,但添加糯麦粉的面包品质下降程度较慢,抗老化效果好,且由感官评定可知,冻藏不同天数后,添加10%糯麦粉的面包最易受人们喜爱。     

Optimization analysis by capillary electrophoresis of thiamine in meat: comparison with high perfomance liquid chromatography

 A new capillary electrophoresis (CE) method for the analysis of thiamine in meat is proposed. Samples were submitted to acidic and enzymatic hydrolysis and the extracts were purified using ethanol and an ion exchange column. The thiamine content was determined by CE using 100 mM sodium tetraborate, 50 mM sodium phosphate (pH 7.6), 50 mM sodium dodecyl sulphate and 10% isopropyl alcohol as a separation buffer solution. The analysis was carried out at 15 kV and 50  °C in a 70 cm effective length× 75 μm i.d. fused-silica capillary using on-column UV detection at 254 nm and 7 s injection time (27 nl injection volume). The results obtained by CE for thiamine contents in meat were compared to those obtained by HPLC using an ion-pair reverse phase column with post-column derivatization and fluorescence detection. Received: 24 August 1998 / Revised version: 21 January 1999     

Characterization of industrial processed milk by analysis of heat-induced changes

Summary Thermal indicators in milk, which had been subjected to one of the six industrial processes of thermization, pasteurization, direct and indirect UHT-sterilization, pre-sterilization and in-bottle sterilization, were studied. The following three indices of heat damage were analyzed by high performance liquid chromatography (HPLC), hydroxymethylfurfural (HMF), lactulose and acid-soluble β-lactoglobulin(β-LG). Average amounts found were 1710 mg/l of β-LG and 2.49 μmol/l of HMF in pasteurized milk. In UHT milk, the amounts for direct and indirect processes were 389 and 322 mg/l of β-LG, 12.0 and 250 mg/l of lactulose and 5.6 and 8.7 μmol/l of HMF. In sterilized milk the amounts were 1120 mg/l of lactulose and 22 μmol/l of HMF, without any detectable presence of undenatured whey proteins. On the basis of the time/temperature profiles, a sterilization factor, expressed as seconds, was defined for each thermal treatment. By applying discriminant analysis each industrial process could be classified independently at the 95% confidence level (pasteurization, UHT-treatment and in-bottle sterilization), but direct-UHT treated milk could not be discriminated from indirect-UHT milk, nor thermized milk from raw bulk milk. The simultaneous application of several heat-induced parameters improves the classification of industrial processed milks, and is therefore a useful tool for optimization of the processing conditions.     

Effect of lipid-based dry eye supplements on the tear film in wearers of eye cosmetics

Purpose

To compare the effects on tear film parameters and contamination in cosmetic eyeliner wearers, after single application of two lipid-based dry eye treatments: a lipid-containing lubricant eye drop and a phospholipid liposomal spray.

Effects of 50% Ethanol Extract from Rosemary (Rosmarinus officinalis) on α-Glucosidase Inhibitory Activity and the Elevation of Plasma Glucose Level in Rats, and Its Active Compound

ABSTRACT:  Rosemary ( Rosmarinus officinalis ) extract with 50% ethanol remarkably inhibited rat intestinal α-glucosidase (sucrase) activity when compared with 31 different herbs and spices (aqueous and 50% ethanol aqueous extracts). Rosemary-distilled extract obtained from 50% ethanol extract by evaporation inhibited α-glucosidase activity in the reaction with both maltose and sucrose. Maltose or sucrose was orally administered, with or without rosemary-distilled extract, to mice at a dose of 20 mg/mouse. A postprandial elevation in plasma glucose levels 30 min after administration of maltose or sucrose plus the distilled extract was significantly suppressed compared with glucose levels in mice that did not receive the distilled extract. A 0.01% aqueous solution of rosemary-distilled extract supplied as drinking water to streptozotocin (STZ)-induced diabetic mice significantly suppressed an increase in plasma glucose levels 4 d after injection of STZ. It was also shown that a 0.01% aqueous solution of the distilled extract inhibited α-glucosidase (maltase and sucrase) in the small intestine of STZ-induced diabetic mice. An active compound with IC₅₀ values of 290 μg/mL (maltase inhibitory activity) and 150 μg/mL (sucrase inhibitory activity) was isolated and identified to be 5,7,3',4'-tetrahydroxy flavone (luteolin). These results suggested that rosemary extract might be a beneficial food material in the prevention of diabetes and obesity.     

Suppressive effect of Tetragenococcus halophilus,isolated from fish-nukazuke,on histamine accumulation in salted and fermented fish

Occasionally, quantities higher than 1000 mg/kg of histamine (Hm) accumulate in salted and fermented fish products by the histidine decarboxylase of halophilic lactococci Tetragenococcus sp. In a total of 200 isolates from fish nukazuke (salted and fermented fish with rice bran), 13 strains produced Hm more than 200 μg/ml in 0.5% histidine containing broth, whereas 130 isolates produced absolutely no Hm. Among the strains, 22 strains suppressed the Hm production of the Hm-forming (HmF) strains. Both the HmF and Hm-suppressing (HmS) strains were identified as Tetragenococcus halophilus. To observe the Hm-suppressing effect, a specified quantity of live cells was needed. In the case of 10% NaCl salted sardine, inoculation with 3 log cells/g of a strain HmF-131 resulted in a significant Hm accumulation, 2800 μg/g in 30 days at 20 °C. The increase in Hm was clearly suppressed by 9 log live cells/g of strain HmS-129. These results suggest that HmS-129 can be used as a starter for salted and fermented fish products, enhancing food safety.     

Effect of pasteurization, vitamin C supplementation and ultraviolet irradiation on the nitrosamine content of palm wine

Palm wine contaminated with varying quantities of the carcinogen dimethylnitrosamine (DMN) was subjected to heat treatments and ultraviolet irradiation. Dimethylnitrosamine (DMN) recoveries and nitrite concentrations were investigated by gas-liquid chromatography (g.l.c.) and colorimetry respectively. Whereas up to 2–6% of the initial DMN concentration was detectable in samples of the alcoholic beverage after raising the temperature of the fermenting drink to 62.5°C and also to 70°C and maintaining these for 30 and 10 min respectively, no nitrosamine was found in any of the palm wine samples treated for 20 min with UV light. Incorporation of 20 mg and 50 mg ascorbic acid into the pasteurized wine containing 2 μmol sodium nitrite, as well as increasing its acidity, appeared to enhance the disappearance of nitrite ions from the beverage.     

Therapeutic profile of a latent heat eyelid warming device with temperature setting variation

PurposeTo compare the effects on ocular temperature and tear film parameters following a single application of a latent heat eyelid warming device at a range of temperature settings.MethodsFifteen subjects were enrolled in a prospective, investigator-masked, randomised, cross-over trial. On separate days, participants were randomised to 10-minute application of a research latent heat device (Laboratoires Théa) at device temperature settings of 45 °C, 50 °C and 55 °C. Outer eyelid and corneal temperatures, tear film lipid layer grade, and non-invasive tear film breakup time (NIBUT) were measured at baseline and immediately after 10 min of device application.ResultsBaseline measurements did not differ between treatment groups (all p > 0.05). Ocular temperatures, lipid layer grade and non-invasive tear film stability rose significantly following device application in all treatment groups (all p < 0.05). The 55 °C setting effected a mean ocular surface temperature rise in the order of +4 °C from baseline, which was 1.46 and 1.26 times greater than at the 45 °C and 50 °C temperature settings, respectively (all p < 0.05). Similarly, improvements in mean non-invasive tear film stability from baseline in the order of +7 s were observed, which were 2.43 and 1.66 times greater than those at the lower temperature settings of 45 °C and 50 °C, respectively (all p < 0.05).ConclusionsAt all temperature settings, the latent heat device resulted in clinically and statistically significant increases in ocular temperature, lipid layer grade, and non-invasive tear film stability. However, the 55 °C setting proved to be most effective at raising ocular temperature (in the order of +4 °C from baseline) and improving tear film stability.     

Evaluating tear clearance rate with optical coherence tomography

Purpose

To assess the early-phase of tear clearance rate (TCR) with anterior segment optical coherence tomography (OCT) and to determine the association between TCR and other clinical measures of the tear film in a group of young subjects with different levels of tear film quality.

Ethics of studies involving human volunteers. II. Relevance and practical implementation for cosmetic scientists

Presented in part at the XXVI Congreso Internacional de la Sociedad Farmace´utica del Mediterra´neo Latino, Medicamentos del siglo XXI: Innovadores y Gene´ricos, Palma de Mallorca, September 16–18, 2004. The aim of this work is to evaluate the stability and release of chitosan beads loaded with volatile molecules of Mentha piperita essential oil (EO) in a cosmetic formulation. The ability of the beads to quickly release Mentha piperita EO during use of a cosmetic formulation such as bath foam is also assessed. The chitosan beads were produced with three different chitosan dispersions gelled with two different gelling solutions: (i) a 10% solution of sodium hydroxide (NaOH) and (ii) a 4% solution of sodium tripolyphosphate (TPP). A few properties of six bead samples loaded with Mentha piperita EO are assessed. The properties are morphology, size, swelling ability, encapsulation efficiency, stability in time, and fast release of Mentha piperita EO during the use phase of the cosmetic formulation.     

Properties of electrospun PVA/nanoclay composites

Laponite^® nanoclay was added to poly(vinyl alcohol) (PVA) solution which was electrospun to make PVA/Laponite^® nanocomposites. After adding Laponite^® nanoclay, fibers were observed to be warped, making their surface rougher. The addition of Laponite^® resulted in less water solubility of electrospun PVA web. PVA/Laponite^® nanocomposite disintegrated after exposure to heat and agitation in water reducing its filtration capability. PVA/Laponite^® nanocomposites showed lower air permeability than electrospun PVA webs probably because of more resistance to air stream caused by rougher and less uniform fiber surface. Tensile and tear strength were weakened by Laponite^® nanoclay due to several reasons: random orientation of nanoclay along fiber axial direction, and fiber discontinuity caused by nanoclay and inhomogeneous distribution of nanoclay.     

HPLC determination of thioglycolic acid and other aliphatic thiols in cosmetic formulations using ethacrynic acid as precolumn derivatization reagent

Limits imposed on the usage of thioglycolic acid, its salts and esters in cosmetic formulations require selective and sensitive analytical methods for their determination. In this study a convenient and reliable method based on high-performance liquid chromatography (HPLC) has been developed. The method involves a precolumn reaction of the thiol compounds with ethacrynic acid to give thiol adducts which can be separated by reversed-phase liquid chromatography and detected at λ= 273 nm.
The derivatization reaction proved to be quantitative under mild conditions (20 min at pH 7.4 and room temperature) and the chromatographic conditions allowed thioglycolic acid, glyceryl monothioglycolate, thiolactic acid, and thioglycolic acid ethyl ester to be discriminated.
The proposed method was successfully applied to the analysis of commercial cosmetic formulations containing thioglycolic acid and glyceryl monothioglycolate, fulfilling the requirements of a general and selective method for the analysis of aliphatic thiols in cosmetics.     

Evaluation of W-Rh permanent modifier for lead determination in sugar by graphite furnace atomic absorption spectrometry

An alternative procedure that improves the performance of graphite atomizers for the determination of Pb in sugar by electrothermal atomic absorption spectrometry is described. The procedure is based on the injection of 10 μl of an acidified aqueous solution containing 8% w/v sugar and 0.2% v/v HNO₃ into integrated graphite platforms. Either transversely (THGA) as well as longitudinally heated graphite atomizers (LHGA) were evaluated by using conventional co-injection of 0.03% Pd + 0.05% Mg(NO₃)₂ or thermally treated platforms with 250 μg W + 200 μg Rh and co-injection of 5 μg l⁻¹ Rh solution. With W-Rh under the same analytical conditions, the lifetimes of THGA and LHGA reached up to 1110 and 900 firings, respectively. With Pd + Mg the LHGA tube lifetime was limited to approximately 500 firings, but for THGA up to 1020 firings were made with a single tube. Characteristic masses were 11 and 29 pg Pb for LHGA and THGA, respectively. Detection limits (3 s) based on sugar blank solution and on integrated absorbance were 5.0 mg kg⁻¹ with LHGA and 9.3 mg kg⁻¹ Pb for THGA. In general, the coefficients of variation of 20 consecutive measurements of a solution containing 50 μg l⁻¹ Pb were lower than 5%. The obtained detection limits are in consonance with the Codex Alimentarius recommendation for the maximum Pb content in the sugar.     

Effect of Hexanal Vapor on Spore Viability of Penicillium expansum, Lesion Development on Whole Apples and Fruit Volatile Biosynthesis

ABSTRACT: The effects of hexanal vapor on spore viability of Penicillium expansum , lesion development on whole apple fruit, and flavor volatile biosynthesis were investigated. Spore viability was reduced by 94% after exposure to a hexanal concentration of 40 μmol/L for 24 h, compared with 50% at 18 μmol/L and 20% at 9 μmol/L. Decay on whole apple fruit inoculated with 5 × 10⁴ spores/mL of P. expansum was reduced with exposure to hexanal vapor for 48 h. Although almost all of the fruit treated with 8 to 12 jmiol/L developed decay lesions, lesion size was reduced compared with the controls. At concentrations of 15 to 19 μmol/L, and 25 to 29 μmol/L, the incidence of fruit with lesions was 44% and 24%, respectively, compared with 100% and 98% in the inoculated control apples and lesion size was further reduced. Apples treated at 4°C with only 5 to 7 jimol/L hexanal vapor also showed a marked reduction in lesion incidence. Hexanal was rapidly converted to high levels of the aroma volatiles hexanol, hexylacetate, hexylbutanoate, and hexylhexanoate, but these decreased to levels similar to the control after 4 to 7 d of being held in air. There was no detectable hexanal after holding fruit in air for 5 h.     

Determination of Polyamines in Baby Food by Gas Chromatography-Mass Spectrometry: Optimization of Extraction and Microwave-Assisted Derivatization Using Response Surface Methodology

The present work evaluates the feasibility of microwave-assisted acylation combined with previous ion-pair extraction for the determination of the polyamines spermidine and spermine in baby food by GC-MS. In this way, extraction and derivatization reaction times were simultaneously optimized using a central composite rotational design. From response surface analysis, we verified maximum analytical response for spermidine and spermine employing 1 M hydrochloric acid solution as extraction solvent under shaking during 35 min, followed by acylation derivatization using a household microwave at 600 W for only 5 min. Limits of detection and quantification of 5 and 10 μg kg^?1 were achieved, and recoveries from 72 to 112% and RSD values ≤16% were obtained under repeatability and within-reproducibility conditions for both polyamines, at levels of 250 and 500 μg kg^?1. The validated GC-MS method was applied for 20 baby food samples commercially available in Brazil, thus resulting in the first report on spermidine and spermine in baby food.     

Determination of aldehydes in tequila by high-performance liquid chromatography with 2,4-dinitrophenylhydrazine derivatization

In this work, the determination of aldehydes in different tequila brands was carried out by high-performance liquid chromatography after derivatization with 2,4-dinitrophenylhydrazine. For the comparative purposes, two commercial brandies were also analyzed. The derivatization agent (50 μl of 3.5 mmol l⁻¹ DNPH in HCl, 2 mol l⁻¹) was added directly to the sample (500 μl) and dinitrophenylhydrazones formed were extracted with hexane. After evaporation of the solvent in nitrogen stream, the residues were dissolved in 100 μl of acetonitrile. The calibration standards were prepared from respective dinitrophenylhydrazones, following the same procedure as for beverage samples. Reversed phase chromatographic separation was achieved on Luna C18 column (250 mm×4.6 mm, 5 μm), using gradient elution (acetonitrile:water, from 68 to 80% of acetonitrile in 20 min) and a total flow rate 1 ml min⁻¹. Spectrophotometric detection for furanic aldehydes was at 390 nm (for other aldehydes at 365 nm). The assignation of chromatographic peaks was accomplished by comparison of their relative retention times and UV/Vis spectra with those of external standards. The method of standard addition was also used. The aldehydes identified were 5-hydroxymethylfurfuraldehyde (t _ret=4.1 min), formaldehyde (t _ret=5.1 min), syringaldehyde (t _ret=5.6 min), acetaldehyde (t _ret=6.2 min), 2-furaldehyde (t _ret=7.2 min) and 5-methylfurfuraldehyde (t _ret=8.9 min). At least four chromatographic peaks with retention times higher than 12 min remained unidentified. The quantification results showed drastically higher concentrations of 2-furaldehyde and 5-methylfuraldehyde in tequilas as referred to brandies. Furthermore, 100% tequilas contained higher levels of these two compounds (for four brands analyzed, mean values 18.6 and 5.97 μg ml⁻¹, respectively) as compared to the mixed brands (five brands analyzed, mean values 6.46 and 3.30 μg ml⁻¹). The results obtained confirm that the profile of furanic aldehydes depends on the type of fructans contained in the raw material and also on heating treatment applied or not prior to fermentation. In contrast to other polysaccharides, inulin hydrolyzes at elevated temperature and the contribution of Maillard browning reactions increases the production of furanic compounds. Our results indicate that the levels of 2-furaldehyde and 5-methylfuraldehyde could be used for discrimination between 100% and mixed tequila brands.     

The impact of exposure on the magnitude of astigmatism formed within the precorneal tear film over the central optical zone of the cornea in ocular surface disease

PurposeTo estimate the astigmatic power and axis of the tear film over the central optical zone of the cornea by vector analysis of topographic data, in ocular surface disease (OSD) and controls, during blink suppression.MethodsVideo-keratoscopic images were captured on opening the eyes after a single blink 5, 10 & 15 s later during blink suppression in OSD patients (mixed aetiology, group 1 age 20 ­ 50 years, n = 12, group 2 > 50 years, n = 38) and controls (group 3, n = 19). The SimK and axis values were used to calculate the astigmatism (power and axis) that formed in the precorneal tear film during each period. Data were aggregated into 3 periods; T0-T5 (between 0 & 5 s after the blink), T5-T10 (5 & 10 s later, T10-T15 (between 10 & 15 s later).ResultsMean (± SD, 95%CI) astigmatic power (DC) formed in the tear film over each period was respectively : Group 1, −0.81 DC (0.99, −1.44 to −0.17), −2.65 DC(1.36, −3.52 to −1.79), −1.37 DC (2.15, −2.73 to −0.01). Group 2, −0.33 DC (0.38, −0.45 to −0.20), −0.57 DC (0.97, −0.91 to −0.24) −0.96 DC (2.10, −1.68 to −0.24), Group 3, −0.57 DC (0.55 −0.76 to −0.38), −0.56 DC (0.57, −0.76 to -0.37), −0.31 DC (0.44, −0.46 to −0.16). Changes were significant in groups 1 (p = 0.013) & 3 (p = 0.033) but not in 2 (p = 0.078). Intergroup differences were significant at all periods (p < 0.05). Significant correlations were detected following vector analysis, e.g Group2 between the astigmatism formed during T5-T10 (y) and ocular surface astigmatism at 5 s was y = 0.281x - 0.834 (r = 0.328, n = 38, p < 0.05). In all three groups apparent changes in the axes of astigmatism were not significant (p > 0.05).ConclusionsChanges in the precorneal tear film after blinking are predominately astigmatic indicating that changes in the central region of the tear film following the natural blink are quasi-orthogonal.     

Effects of recombinant bovine interleukin-8 (rbIL-8) treatment on health,metabolism, and lactation performance in Holstein cattle I: Production and functional characterization of rbIL-8 in vitro and in vivo

In the present study, we standardized processes of cloning and purification of recombinant bovine interleukin-8 (rbIL-8) from bacterial culture and assessed its biological activity in Holstein cattle. Plasmid containing a subclone of bovine IL-8 was expressed using Escherichia coli BL21 and cell lysate was purified by chromatography. The presence of rbIL-8 was assessed by Western blot analyses and function was confirmed in vitro using a chemotaxis chamber. Based on optical density values, chemoattractant properties of rbIL-8 were 10-fold greater compared with control wells. Two in vivo studies were conducted to assess the biological activity of rbIL8. For study 1, one-year-old Holstein heifers (n = 20) were randomly allocated to receive a single intravaginal administration containing 1,125 µg of rbIL-8 diluted in 20 mL of saline solution (rbIL-8, n = 10) or a single intravaginal administration of 20 mL of saline solution (control, n = 10). For study 2, nonpregnant lactating Holstein cows (n = 31) were randomly allocated to receive an intrauterine administration with 1,125 µg of rbIL-8 diluted in 20 mL of saline solution (rbIL-8, n = 11), a positive control consisting of resin-purified lysate of E. coli BL21 not transfected with the plasmid coding for rbIL-8 diluted in 20 mL of saline solution (E. coli, n = 10), and a negative control administered with 20 mL of saline solution (control, n = 10). An increase in vaginal neutrophils was observed in heifers treated with rbIL-8 within 3 h of treatment, but not in control heifers. Additionally, intrauterine administration of rbIL-8 increased the proportion of PMN cells in uterine cytological samples from 3.5% before treatment to 75.8% 24 h later—an increase that was not observed in the negative control group and cows treated with resin-purified lysate of E. coli. To further evaluate the effect of local and systemic rbIL-8 stimulation on the dynamics of circulating white blood cells, a third study was conducted. In study 3, nonpregnant 8-mo-old Holstein heifers (n = 30) were randomly allocated into 1 of 3 treatment groups: intravenous rbIL-8 (1,125 µg of rbIL-8 diluted in 5 mL of saline solution, n = 10); intravaginal rbIL-8 (1,125 µg of rbIL-8 diluted in 20 mL of saline solution; n = 10); or intravaginal saline (20 mL of saline solution, n = 10). Intravenous injection of rbIL-8 resulted in a transient increase in rectal temperature, which was greater at 2 h after treatment compared with cows treated intravaginally with rbIL-8 or heifers treated with saline solution. Heifers treated with rbIL-8 intravenously displayed a marked reduction in neutrophils, basophils, lymphocytes, and monocytes within the first 4 h posttreatment compared with heifers treated intravaginally. However, at 6 h after treatment, heifers treated with rbIL-8 intravenously displayed a rebound in white blood cell counts caused by an increase in neutrophil counts. These results show that the presented purification method is effective and results in biologically active rbIL-8 that can be used safely to modulate immune responses in cattle.