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PubMed1990

Ranking of the antipsoriatic effect of various topical corticosteroids applied under a hydrocolloid dressing--skin-thickness, blood-flow and colour measurements compared to clinical assessments.

In 10 patients with chronic plaque type psoriasis one or two plaques affected equally with psoriasis were chosen for study. Five punched out rings of a hydrocolloid dressing were applied to the psoriasis plaque(s). In each circular test area 20 mg of one of the following creams was applied: base, 1% hydrocortisone (DAK), 0.1% triamcinolone acetonide (Kenalogue), 0.1% betamethasone-17-valerate cream (Betnovate), and 0.05% clobetasol proprionate cream (Dermovate). The areas were occluded with a thin film of transparent hydrocolloid dressing (Comfeel Transparent Dressing), for 1 week. Non-invasive measurements (ultrasound skin thickness, laser-Doppler flowmetry, colorimetry) were performed before and after treatment. Therapeutic response was evaluated blindly by clinical score. The measurements showed a decline in blood flow, a decrease in skin thickness, and normalization of colour approaching that of normal skin, the more potent the corticosteroid used. The clinical scores showed the same: the more potent a corticosteroid used, the closer to the score of normal skin. Data on variability and applications of the methods are presented. The study concludes that potent corticosteroids occluded with a hydrocolloid dressing can clear psoriasis in 1 week. Short-course corticosteroid therapy appears harmless and relevant for clinical dermatology.

Administration, Topical↗

PubMed1994

Effects of softened and unsoftened fabrics on infant skin.

BACKGROUND: The effects of softened and unsoftened fabrics on the skin of infants of 1-12 months of age were evaluated under real life conditions of skin contact with fabrics. METHODS: During 4 weeks, 24 infants wore cotton fabrics washed with a granular detergent on one side of their lower back, and on the other side, cotton fabrics washed with the same detergent and softened with a liquid fabric softener. Skin effects were evaluated by visual grading for redness, dryness, and smoothness, by skin stripping and measuring of Chroma C* (squamometry), by measurements of elasticity and bioelastic ratio, and by instrumental measurements of skin parameters (pH, capacitance, transepidermal water loss (TEWL), and erythema by colorimetry). RESULTS: No deleterious effects were observed in any infant. A decrease in squamometry (Chroma C*) and an increase in capacitance were detected in skin exposed to softened fabrics relative to unsoftened ones. Values of pH tended to be higher in the sites treated with softened versus unsoftened fabrics (pH 6.06 and 5.87, respectively, at end of study). All other parameters showed no significant differences in the two treatment groups. CONCLUSIONS: Neither softened nor unsoftened fabrics produced any adverse effects on the skin of infants after continuous wearing during 29 days. A slight beneficial effect on the infants' skin was observed with softened relative to unsoftened fabrics. Methods measuring the structure and function of the stratum corneum were more sensitive discriminators of the effects of fabrics on the skin than traditional methods of visual clinical evaluation.

Double-Blind Method↗

PubMed2004

A double-blind randomized trial of 5% ascorbic acid vs. 4% hydroquinone in melasma.

BACKGROUND: Melasma is an acquired treatment-resistant hyperpigmentation of the skin. METHODS: Sixteen women with idiopathic melasma were included in our trial. After randomization by another clinician, they were instructed to use, at night, 5% ascorbic acid cream on one side of the face and 4% hydroquinone cream on the other side, for 16 weeks. Sunscreen was applied daily throughout the period of observation. They were evaluated every month by colorimetry, digital photography, and regular color slides. Subjective evaluation by each patient was also taken into account. RESULTS: The best subjective improvement was observed on the hydroquinone side with 93% good and excellent results, compared with 62.5% on the ascorbic acid side (P < 0.05); however, colorimetric measures showed no statistical differences. Side-effects were present in 68.7% (11/16) with hydroquinone vs. 6.2% (1/16) with ascorbic acid. CONCLUSION: Although hydroquinone showed a better response, ascorbic acid may play a role in the therapy of melasma as it is almost devoid of side-effects; it could be used alone or in combination therapy.

Administration, Topical↗

PubMed1976

N-acetyl-9-O-L-lactylneuraminic acid, a new acylneuraminic acid from bovine submandibular gland.

The acylneuraminic acid fraction, obtained on mild acid hydrolysis of glycoproteins from bovine submandibular glands, contains approximately 2% N-acety-9-O-L-lactylneuraminic acid. The compound has been isolated and purified by ion-exchange and cellulose column chromatography. The structure has been elucidated using thin-layer chromatography, colorimetry, gas-liquid chromatography/mass spectrometry, periodate oxidation and specific lactate dehydrogenases. An evaluation of the different analytical methods is given.

Animals↗

PubMed1983

The vanadate complex of the calcium-transport ATPase of the sarcoplasmic reticulum, its formation and dissociation.

Vanadate binding to different sarcoplasmic reticulum membrane preparations was determined by measuring bound vanadate colorimetrically and by phosphorylating the vanadate-free enzyme fraction with [gamma-32P] ATP. Colorimetry allowed the study of the dependence of equilibrium vanadate binding on ionized magnesium and the displacing effect of ionized calcium at vanadate concentrations greater than 0.1 mM only. At saturating magnesium concentration the enzyme binds 6-8 nmol vanadate/mg protein and half-maximum saturation is reached at 40 microM. Vanadate is displaced from the enzyme when its high-affinity calcium-binding sites are saturated and conversely calcium is solely displaced from its high-affinity binding sites by vanadate. The phosphorylation procedure allowed the measurement of equilibrium binding as well as the kinetics of vanadate binding and release at vanadate concentrations below 0.1 mM. Half-times of 30s and 3s were observed for vanadate release induced by 0.1 mM and 1 mM calcium respectively. Millimolar concentrations of ATP are required for vanadate displacement. Under equilibrium conditions the enzyme displays an affinity for vanadate of 1.6 X 10(6) M-1. The dependence on the concentration of vanadate of the rate of vanadate binding yielded an affinity of only 1 X 10(4) M-1. Closed vesicles bind vanadate much more slowly than calcium-permeable preparations. The initial rate of calcium-induced vanadate dissociation is accelerated considerably when the vesicles are made calcium permeable. The rate of vanadate dissociation from calcium-permeable vesicles reaches half-maximum values at 1-2 mM calcium indicating that the internal low-affinity calcium-binding sites must first be occupied in order to release bound vanadate. The results suggest that vanadate binding leads to a transition of the external high to internal low-affinity calcium-binding sites.

Animals↗

PubMed1992

Redox properties of the iron-sulfur clusters in activated Fe-hydrogenase from Desulfovibrio vulgaris (Hildenborough).

The periplasmic Fe-hydrogenase from Desulfovibrio vulgaris (Hildenborough) contains three iron-sulfur prosthetic groups: two putative electron transferring [4Fe-4S] ferredoxin-like cubanes (two F-clusters), and one putative Fe/S supercluster redox catalyst (one H-cluster). Combined elemental analysis by proton-induced X-ray emission, inductively coupled plasma mass spectrometry, instrumental neutron activation analysis, atomic absorption spectroscopy and colorimetry establishes that elements with Z > 21 (except for 12-15 Fe) are present in 0.001-0.1 mol/mol quantities, not correlating with activity. Isoelectric focussing reveals the existence of multiple charge conformers with pI in the range 5.7-6.4. Repeated re-chromatography results in small amounts of enzyme of very high H2-production activity determined under standardized conditions (approximately 7000 U/mg). The enzyme exists in two different catalytic forms: as isolated the protein is 'resting' and O2-insensitive; upon reduction the protein becomes active and O2-sensitive. EPR-monitored redox titrations have been carried out of both the resting and the activated enzyme. In the course of a reductive titration, the resting protein becomes activated and begins to produce molecular hydrogen at the expense of reduced titrant. Therefore, equilibrium potentials are undefined, and previously reported apparent Em and n values [Patil, D. S., Moura, J. J. G., He, S. H., Teixeira, M, Prickril, B. C., DerVartanian, D. V., Peck, H. D. Jr, LeGall, J. & Huynh, B.-H. (1988) J. Biol. Chem. 263, 18,732-18,738] are not thermodynamic quantities. In the activated enzyme an S = 1/2 signal (g = 2.11, 2.05, 2.00; 0.4 spin/protein molecule), attributed to the oxidized H cluster, exhibits a single reduction potential, Em,7 = -307 mV, just above the onset potential of H2 production. The midpoint potential of the two F clusters (2.0 spins/protein molecule) has been determined either by titrating active enzyme with the H2/H+ couple (E,m = -330 mV) or by dithionite-titrating a recombinant protein that lacks the H-cluster active site (Em,7.5 = -340 mV). There is no significant redox interaction between the two F clusters (n approximately 1).

Copper↗

PubMed2005

Striae distensae in darker skin types: the influence of melanocyte mechanobiology.

INTRODUCTION: Striae distensae in White people are commonly described as being reddish at first and turning white in time. This dual perception has been challenged. Indeed, the color difference between striae distensae and their surrounding skin varies on a wide range in part depending upon typology. AIM: To study striae nigrae that are found only in subjects of darker complexion. MATERIALS AND METHODS: In the present study conducted in 44 darker skin adults, dermoscopy was combined to reflectance colorimetry. RESULTS: Striae nigrae exhibited hypermelanosis of the epidermal rete ridges crossing transversally the lesions in a laddering pattern. By contrast, striae albae showed only faint melanotic networks. CONCLUSIONS: As striae distensae are in part under the influence of skin stretching, their colors are likely to be controlled by some mechanobiological process activating or inhibiting melanogenesis in people of darker complexion. No argument involving an inflammatory mechanism is supported by the present observations.

Journal Article↗

PubMed1996

Increased interleukin-8 release by beta-adrenoceptor activation in human transformed bronchial epithelial cells.

1. The effect of beta-adrenoceptor activation on release of the neutrophil chemoattractant, interleukin-8 (IL-8), was examined in human transformed bronchial epithelial cells (16HBE cells). 2. The combined beta 1- and beta 2-adrenoceptor agonist, isoprenaline, time- (100 nM, 2-18 h) and concentration- (1-30 nM) dependently increased IL-8 protein content in the cell culture supernatant as measured by an enzyme immunosorbent assay standardized for DNA by fluoro-colorimetry. 3. Isoprenaline (1-100 nM, 15 min) increased cyclic AMP concentration-dependently. 4. The effect of isoprenaline (100 nM) was inhibited by the beta-adrenoceptor blocker propranolol (10 microM). The maximum magnitude of IL-8 increase caused by beta-adrenoceptor activation was 40% of that caused by the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha 100 ng ml-1). 5. The selective beta 2-adrenoceptor agonist salbutamol (1 microM), increased IL-8 protein similarly to isoprenaline and the cyclic AMP analogue, dibutyryl cyclic AMP (1 mM) produced a corresponding effect. 6. Pretreatment with isoprenaline (100 nM) followed by TNF-alpha (20 ng ml-1) increased IL-8 additively. 7. In conclusion, beta-adrenoceptor stimulation increased the release of the neutrophil chemoattractant, IL-8 in 16HBE cells, via an increase in intracellular cyclic AMP. beta-adrenoceptor stimulation adds to the IL-8 increase caused by the pro-inflammatory cytokine TNF-alpha. If this mechanism exists in vivo, beta-adrenoceptor activation may increase neutrophil chemotaxis into the airways.

Adrenergic beta-2 Receptor Antagonists↗

PubMed1997

Glycolic acid peels for postinflammatory hyperpigmentation in black patients. A comparative study.

BACKGROUND: Treatment of postinflammatory hyperpigmentation in patients of Fitzpatrick skin types IV, V, and VI is difficult. Glycolic acid peels are useful for pigment dyschromias in caucasians; however, there are no controlled studies examining their safety and efficacy in dark-complexioned individuals. OBJECTIVE: To determine if serial glycolic acid peels provide additional improvement when compared with a topical regimen of hydroquinone and tretinoin. METHODS: Nineteen patients with Fitzpatrick skin type IV, V, or VI were randomized to a control or peel group. The control group applied 2% hydroquinone/10% glycolic acid gel twice daily and 0.05% tretinoin cream at night. The peel patients used the same topical regimen and, in addition, received six serial glycolic acid peels (68% maximum concentration). Patients were evaluated with photography, colorimetry, and subjectively. RESULTS: Sixteen patients completed the study. Both treatment groups demonstrated improvement, but the patients receiving the glycolic acid peels showed a trend toward more rapid and greater improvement. The peel group also experienced increased lightening of the normal skin. CONCLUSIONS: This pilot study demonstrates that serial glycolic acid peels provide an additional benefit, with minimal adverse effects, for the treatment of postinflammatory hyperpigmentation in dark-complexioned individuals.

Administration, Topical↗

PubMedDate not supplied

Cerebrospinal fluid sodium increases in migraine.

BACKGROUND: Pharmaceuticals with calcium- or sodium-channel-blocking activity have proven useful for migraine prophylaxis, and calcium channel, sodium transporter, and sodium channel gene mutations have been found in familial hemiplegic migraine. However, it is not known whether calcium or sodium homeostasis is altered in migraine. OBJECTIVE: To compare levels of sodium, calcium, potassium, and magnesium in cerebrospinal fluid (CSF) and blood plasma between migraineurs and controls. METHODS: We recruited 20 migraineurs without aura and 11 controls prospectively, and studied migraineurs in sick (MH(+)) and well (MH(-)) states. We collected lumbar CSF and venous blood plasma, quantified elements with ion-selective electrodes or colorimetry, and determined osmolality by depression of freezing point. We compared levels of Na(+), Ca(2+), K(+), and Mg among and also within subjects who were studied in both MH(+) and MH(-) states. RESULTS: Mean CSF Na(+) levels were increased by 3 mmol/L in MH(+) compared with MH(-) and by 4 mmol/L compared to controls (P < 0.005). In 4 subjects who were sampled in both MH(+) and MH(-) states, mean CSF Na(+) concentration increased by 2 mmol/L in the MH(+) state compared with the MH(-) state (P < 0.05). Simultaneous plasma Na(+) levels did not differ among the 3 clinical groups, nor did osmolality, total Ca and Ca(2+), K(+), and total Mg levels in CSF. CONCLUSIONS: Compared to both controls and the MH(-) state, CSF Na(+) concentration increased in MH(+) independently from other clinical or pharmacological fluctuations, CSF concentrations of Ca(2+), Mg, and K(+), and blood plasma Na(+) levels. These results implicate a deviation of Na(+) homeostasis in migraine. The modestly elevated extracellular Na(+) in MH(+) may cause the neural changes that underlie clinical features of migraine.

Calcium↗

PubMed1993

Efficacy of skin barrier creams (III). The repetitive irritation test (RIT) in humans.

2 barrier creams (BC) were evaluated against the anionic detergent sodium lauryl sulphate (SLS) using a new human test model. In the repetitive irritation test (RIT) on human skin, the irritant SLS is applied to the ventral forearm of healthy volunteers daily for 2 weeks. 1%, 5%, and 10% SLS is exposed to the skin for 30 min, using a glass cup 2.5 cm in diameter. The BC is applied 30 min before the irritant. Cutaneous irritation is assessed on a score for erythema (0 to 5+), and quantified by various biophysical techniques: transepidermal water loss (TEWL) by evaporimetry, skin blood flow volume (BFV) by laser-Doppler velocimetry, and skin colour by colorimetry (La* value). 10 subjects were tested with SLS on one forearm without pretreatment (control) and with Taktosan Salbe as BC on the other forearm. A 2nd panel of 10 subjects was tested in the same way with SLS and Marly skin as BC. Taktosan Salbe was extremely effective in reducing the irritation by SLS: there were significant differences regarding all test parameters for 10% SLS in the 2nd week. The most differentiating parameter was TEWL, revealing statistical differences as early as the 1st week for 10% SLS and Taktosan Salbe, while the least differentiating sensitivity was found for La*. In contrast, there was no significant suppression of irritancy in any parameter with Marly skin, either in the 1st week or in the 2nd week with any concentration of SLS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Comparison of in vitro predictive tests for irritation induced by anionic surfactants.

Skin compatibility of anionic surfactants may often but not always be predicted by in vitro tests. For instance, the correlation between in vivo and in vitro data is classically hampered in the presence of magnesium. This ion is known to interfere with in vitro skin irritation predictive tests based on protein denaturation. This study was conducted to compare a recently introduced assay, corneosurfametry, with other in vitro tests including the pH-rise of bovine serum albumin, collagen swelling, and zein solubilization tests. Corneosurfametry entails collection of cyanoacrylate skin surface strippings and short contact time with surfactants, followed by staining samples with toluidine blue and basic fuchsin dyes. Measurements are made by reflectance colorimetry. Data show that irritation potentials predicted by corneosurfametry agree with those obtained by established in vivo and in vitro irritation tests. Moreover, corneosurfametry data are not artificially lowered by addition of magnesium in surfactant solutions. In conclusion, corneosurfametry should be viewed as one of the realistic predictive tests for surfactant irritancy.

Collagen↗

PubMed2004

Effects of repeated sunbed exposures on the human skin. In vivo measurements with confocal microscopy.

BACKGROUND: Ultraviolet (UV) lamps used in commercial sunbeds are usually defined as UVA sources. Although it is well accepted that sunbed exposure significantly increases melanin pigmentation, its capacity to induce epidermal thickening is discussed controversially. OBJECTIVES: The aim of this study was to assess non-invasively the effects of repeated sunbed exposures on epidermal thickness, cell size, and pigmentation by means of confocal laser-scanning microscopy (CLSM) in vivo. METHODS: Eight volunteers had sunbed exposures six times in a 3-week period (cumulative dose: 126 J/cm(2) UVA). During irradiation, a small site (2 cm x 2 cm) on the lateral aspect of the inner forearm was covered with a UV-opaque sheet (non-exposed site). CLSM was performed with the Vivascope (Lucid, Henrietta, NY, USA) 24 h after the last UVA exposure on non-exposed sites and UVA-exposed sites that were on the medial aspect of the inner forearm at a distance of 2 cm to the non-exposed measurement site. The following parameters were assessed: thickness of the horny layer (DSC), minimal thickness of the epidermis (E(min)), minimal thickness of the viable epidermis (VE(min)), cell size of the granular layer (A(gran)), and the epidermal melanin content (MI). Additionally, colorimetric measurements have been carried out on non-exposed and UVA-exposed sites. RESULTS: DSC of the UVA-exposed skin was significantly higher than the one of non-exposed sites (mean+/-SD: 15+/-2.9 microm vs. 12.8+/-3 microm). Although E(min) was significantly higher in UVA-exposed sites (mean+/-SD: 40.4+/-3.6 microm vs. 39+/-2.9 microm), a slight but not statistically significant (P>0.05) decrease of VE(min) was observed (25.5+/-2.1 microm vs. 26.2+/-2.4 microm). The median of cell size of the granular layer (A(gran)) significantly (P=0.008) differed between non-exposed (752.1 microm(2)) and UVA-exposed sites (600 microm(2)). MI was significantly (P=0.014) higher for the UVA-exposed skin (1.12 vs. 1.34). Accordingly, colorimetry revealed significantly (P< 0.01) lower skin brightness for UVA-exposed sites (L*=60.2+/-4.3) as compared with non-exposed sites (L*=63.4+/-3.9). CONCLUSIONS: Sunbed exposures seem to induce photoadaptation not only by skin pigmentation but also by epidermal thickening that is predominantly due to an increase in thickness of the horny layer. Moreover, our data indicate that UVA radiation has an influence on the cell size of the granular layer. CLSM is a promising tool for photobiological studies in vivo.

Adaptation, Physiological↗

PubMed2005

Inhibitory effect of picroside II on hepatocyte apoptosis.

AIM: To investigate the influence of picroside II on hepatocyte apoptosis and its mechanism. METHODS: Morphological changes and quantification of apoptotic cells were determined under transmission electron microscopy and flow cytometry respectively. DNA fragmentation was visualized by agarose gel electrophoresis. Semi-quantitative reverse transcription-PCR (RT-PCR) was used to analyze the expression of bcl-2 and bax genes. The content of manganese-superoxide dismutase (SOD) in liver mitochondria was detected by the Marland method. The content of malonic aldehyde (MDA) and the protein level in liver tissue were determined by thiobarbituric acid colorimetry and Lowry method. RESULTS: Picroside II decreased the levels of alanine aminotransferase and aspartate aminotransferase in the serum resulting from acute-liver injured mice induced with D-GalN and LPS; it also reduced the content of MDA, and thus, enhanced the activity of SOD. Picroside II 10 mg/kg was found to protect hepatocytes against apoptosis in a dose-dependent manner; it up-regulated the expression of bcl-2 genes, thus increased the bcl-2/bax ratio. CONCLUSION: Picroside II can protect hepatocytes against injury and prevent hepatocytes from apoptosis. It might by upregulating the bcl-2 gene expression and antioxidation.

Animals↗

PubMedDate not supplied

Blood stasis contributions to the perception of skin pigmentation.

The chromatic characteristics of skin color arise from the interactions of light (primarily absorption and scattering) with the epidermis and the dermis. The primary light absorbers in skin are hemoglobin and melanin. Most of scattering is attributed to collagen fibers and in pigmented skin to melanosomes. Traditionally skin redness is considered to arise due to locally elevated concentrations of hemoglobin, whereas skin pigmentation is attributed to melanin. In this study we attempt to understand better the contributions of these chromophores to the perceived skin color using spectral analysis of skin color reactions induced by ultraviolet (UV) irradiation or pressure. In the first experiment 12 individuals with skin phototypes III-IV were irradiated on the back using a solar simulator with doses ranging from 0.7 to 3 MED. The skin reactions were evaluated on days 1, 7, 14, and 21 after irradiation. Evaluations included diffuse reflectance spectroscopy (DRS) and clinical assessment of the erythema and the pigment reaction. Apparent concentrations of melanin, oxy-, and deoxy-hemoglobin were calculated from the absorption spectra. In the second experiment the levels of deoxy-hemoglobin of the volar forearm of ten volunteers were selectively altered by either application of a pressure cuff or by topical application of 3% H(2)O(2). Changes in skin color appearance were documented by photography, colorimetry, and DRS. In the UV exposure experiment all reactions were dose dependent. Oxy-hemoglobin values increased to a maximum on day 1, correlating well with the clinical evaluation of erythema, and then decreased exponentially to base line. Melanin showed a significant increase on day 7 and remained relatively constant for the next 3 weeks, correlating well with the clinical evaluation of pigmentation (tanning). Deoxy-hemoglobin increased slightly on day 1 and remained elevated for the next 2 weeks. Thus, deoxy-hemoglobin correlated moderately with the clinical erythema scoring on day 1 only, while it contributes significantly to what is clinically perceived as skin tanning on days 7 and 14. Application of pressure below the diastolic level increased deoxy-hemoglobin concentration as measured by DRS. This increase corresponded to a decrease of a "pigmentation" parameter (based on the L(*)a(*)b(*) scale) in a similar fashion that has been documented for increases in melanin concentration. Topical H(2)O(2) application reduced deoxy-hemoglobin levels as measured by DRS. This reduction coincided kinetically with a visible skin blanching. Application of pressure or H(2)O(2) did not significantly alter the levels of oxy-hemoglobin or melanin. In this report we present compelling evidence that deoxy-hemoglobin significantly contributes to the skin color appearance. Blood pooling, expressed as increased deoxy-hemoglobin, can contribute to what is visually perceived as pigmentation. Furthermore, we present that measurement of its contribution to the skin color appearance can only be accomplished with DRS.

Administration, Topical↗

PubMed1976

Synthesis and release of polyribophosphate by Haemophilus influenzae type b in vitro.

Polyribophosphate, the capsular polysaccharide antigen of Haemophilus influenzae type b, can be assayed in crude bacterial extracts by a combination of immunoprecipitation, hot-acid extraction, and colorimetry. In vitro, the antigen is synthesized during growth and, in well-buffered media, in early stationary phase as well. It is shed from the cell throughout the course of synthesis, and at 37 C almost all the extractable antigen has been released spontaneously within several hours after synthesis. Various strains are similar in extent of synthesis and gross composition of the antigen; however, strains differ in the rate of release during exponential phase. The antigen is released as (or as part of) a very large structure, although under certain culture conditions much smaller antigenic units are found.

Antigens, Bacterial↗

PubMed1984

Bacterial endotoxin isolated from a water spray air humidification system as a putative agent of occupation-related lung disease.

Outbreaks of hypersensitivity pneumonitis or humidifier fever were attributed to the inhalation of organic material aerosolized by a chilled-water spray humidification system. The purpose of this study was to isolate and characterize the serologically detectable antigen(s) present in extracts obtained from the humidification system. By using bicarbonate or phenol-water extractions or both, the antigen was isolated and characterized, using colorimetry, gas-liquid chromatography, reverse-phase high-performance liquid chromatography, and X-ray fluorescence. Carbohydrates, hexosamines, phosphorus, and even-numbered saturated and unsaturated fatty acids were constituents of the serologically detectable antigen. When tested in in vivo and in vitro assays, the antigen had demonstrable endotoxin activity. All subjects with biopsy-proven lung disease and a majority of subjects suspected of having lung disease had antibodies directed toward the purified endotoxin. The data strongly suggest that an aerosolized bacterial endotoxin is a putative agent inducing lung disease.

Alveolitis, Extrinsic Allergic↗

PubMed2002

Hepatic veno-occlusive disease as a result of a traditional remedy: confirmation of toxic pyrrolizidine alkaloids as the cause, using an in vitro technique.

BACKGROUND/AIMS: A child presented with hepatic veno-occlusive disease after having been administered a short course of treatment with a traditional herbal remedy. The child subsequently died. Postmortem liver histology confirmed the diagnosis. This study aimed to investigate the hypothesis that the herbal remedy was the cause of veno-occlusive disease. METHODS: Extracts of the traditional remedy were analysed by colorimetry and gas chromatography/mass spectrometry. Cultured hepatocytes were treated with an extract of the plant material and examined for morphological changes. RESULTS: The screening analyses indicated the presence of toxic pyrrolizidine alkaloids, which were later confirmed by gas chromatography/mass spectrometry. The cell studies indicated dose related toxicity, with necrosis at high concentrations and apoptosis and abnormalities of the cytoskeleton at lower concentrations. CONCLUSIONS: The simple screening techniques used allowed rapid confirmation of the presence of toxic pyrrolizidines in the remedy. The in vitro method confirmed the toxicity of herbal extracts to hepatocytes.

Cell Culture Techniques↗