Sedimentary Cobalt Protoporphyrin as a Potential Precursor of Prosthetic Heme Group for Bacteria Inhabiting Fossil Organic Matter-Rich Shale Rock

This study hypothesizes that bacteria inhabiting shale rock affect the content of the sedimentary cobalt protoporphyrin present in it and can use it as a precursor for heme synthesis. To verify this hypothesis, we conducted qualitative and quantitative comparative analyses of cobalt protoporphyrin as well as heme, and heme iron in shale rock that were (i) inhabited by bacteria in the field, (ii) treated with bacteria in the laboratory, and with (iii) bacterial culture on synthetic cobalt protoporphyrin. Additionally, we examined the above-mentioned samples for the presence of enzymes involved in the heme biosynthesis and uptake as well as hemoproteins. We found depletion of cobalt protoporphyrin and a much higher heme concentration in the shale rock inhabited by bacteria in the field as well as the shale rock treated with bacteria in the laboratory. Similarly, we observed the accumulation of protoporphyrin in bacterial cells grown on synthetic cobalt protoporphyrin. We detected numerous hemoproteins in metaproteome of bacteria inhabited shale rock in the field and in proteomes of bacteria inhabited shale rock and synthetic cobalt protoporhyrin in the laboratory, but none of them had all the enzymes involved in the heme biosynthesis. However, proteins responsible for heme uptake, ferrochelatase and sirohydrochlorin cobaltochelatase/sirohydrochlorin cobalt-lyase were detected in all studied samples.

Afterglow Amplification for Fast and Sensitive Detection of Porphyria in Whole Blood

Porphyria is a group of genetic photodermatoses that cause too much porphyrin to accumulate in the blood, skin, and liver, resulting in skin photosensitivity and damage, liver disease, or potential liver failure. Conventional detection methods include high-performance liquid chromatography and fluorescence spectrometry. However, these methods usually require complicated pretreatment and time-consuming processes. Therefore, efficient and fast detection of porphyria is urgently needed. Herein, we develop a molecular afterglow reporter-based sensing scheme for the detection of porphyrins in whole blood. The afterglow reporter can respond to the production of singlet oxygen (¹O₂) of porphyrins after light excitation, and the detection signals can be amplified through adjusting the amount of singlet oxygen and afterglow reporter molecules. Moreover, without the use of a real-time excitation source, afterglow signals can avoid the scattering and autofluorescence interference in biological samples, thereby reducing background noise. More importantly, we prove the applicability of the afterglow reporter in the quantitative detection of porphyrins in whole blood and demonstrate its great clinical potential.

5-Aminolevulinic acid-mediated photodynamic activity in patient-derived cholangiocarcinoma organoids

BACKGROUND

Accurate diagnosis of the disease extension of cholangiocarcinoma (CCA) is often difficult in clinical practice. The diagnostic yield of conventional pre-operative imaging or endoscopic procedures is sometimes insufficient for the evaluation of longitudinal spreading of CCA. Here we investigated the usefulness of 5-aminolevulinic acid (5-ALA) for the pre- or intra-operative diagnosis of CCA, using patient-derived organoids.

METHODS

Four CCA- and two adjacent tissue-derived organoids were established. After 5-ALA treatment, we assessed their photodynamic activity using fluorescence microscopy.

RESULTS

CCA organoids established from different patients showed diverse morphology in contrast to monolayer structures of non-tumor organoids, and had the ability to form subcutaneous tumors in immunodeficient mice. CCA organoids demonstrated remarkably high photodynamic activity based on higher accumulation of protoporphyrin IX as a metabolite of 5-ALA compared to non-tumor organoids (40-71% vs. < 4%, respectively). Importantly, cancer cell-specific high photodynamic activity distinguished the organoids originated from biliary stenotic lesions from those of non-stenotic lesions in a CCA patient. The high photodynamic activity did not depend on the expression profile of heme biosynthesis genes.

CONCLUSIONS

Distinct 5-ALA-based photodynamic activity could have diagnostic potential for the discrimination of CCA from non-tumor tissues.

Organochlorine pesticides and polychlorinated biphenyls in common kestrel eggs from the Canary Islands: Spatiotemporal variations and effects on eggshell and reproduction

Organochlorine (OC) pesticides were widely used on the Canary Islands (Spain) for intensive crop production and against plagues of African locust. A previous study performed in 1988-1994 showed a high concentration of p,p'-DDE in the eggs of common kestrels (Falco tinnunculus) from the island of Tenerife. The present study shows OC pesticide and polychlorinated biphenyl (PCBs) levels in 40 unhatched common kestrel eggs collected from southern Tenerife between 2009 and 2016. The protoporphyrin IX in eggshells has also been analysed in order to explore the use of this pigment as a biomarker. Egg biometry, status of embryo development, eggshell thickness and mass of extractable lipids of each egg were recorded. Surrounding land use and reproductive parameters (hatching and fledging rates) were obtained for each nest. The most abundant compound was p,p'-DDE (15.0 μg/g d.w), followed by PCBs (0.46 μg/g d.w.). The decline in p,p'-DDE levels in southern Tenerife (with 23.6 μg/g d.w. in 1988-1994) was 36.4%. p,p'-DDE levels were positively associated with the surface of active and abandoned cropland in a 200 m-radius around the nest and with proximity to urban areas. PCB levels were associated with proximity to roads. Shell thickness was negatively affected by the p,p'-DDE concentration. The concentration of protoporphyrin IX in the eggshell was negatively associated with the concentration of hexachlorobenzene in the egg content. Despite the total ban on the use of p,p'-DDT in Spain since 1986, p,p'-DDE levels remain elevated in those areas in which that use was formerly intensive.

Scanning Fiber Endoscope Improves Detection of 5-Aminolevulinic Acid-Induced Protoporphyrin IX Fluorescence at the Boundary of Infiltrative Glioma

OBJECTIVE

Fluorescence-guided surgery with protoporphyrin IX (PpIX) as a photodiagnostic marker is gaining acceptance for resection of malignant gliomas. Current wide-field imaging technologies do not have sufficient sensitivity to detect low PpIX concentrations. We evaluated a scanning fiber endoscope (SFE) for detection of PpIX fluorescence in gliomas and compared it to an operating microscope (OPMI) equipped with a fluorescence module and to a benchtop confocal laser scanning microscope (CLSM).

METHODS

5-Aminolevulinic acid-induced PpIX fluorescence was assessed in GL261-Luc2 cells in vitro and in vivo after implantation in mouse brains, at an invading glioma growth stage, simulating residual tumor. Intraoperative fluorescence of high and low PpIX concentrations in normal brain and tumor regions with SFE, OPMI, CLSM, and histopathology were compared.

RESULTS

SFE imaging of PpIX correlated to CLSM at the cellular level. PpIX accumulated in normal brain cells but significantly less than in glioma cells. SFE was more sensitive to accumulated PpIX in fluorescent brain areas than OPMI (P < 0.01) and dramatically increased imaging time (>6×) before tumor-to-background contrast was diminished because of photobleaching.

CONCLUSIONS

SFE provides new endoscopic capabilities to view PpIX-fluorescing tumor regions at cellular resolution. SFE may allow accurate imaging of 5-aminolevulinic acid labeling of gliomas and other tumor types when current detection techniques have failed to provide reliable visualization. SFE was significantly more sensitive than OPMI to low PpIX concentrations, which is relevant to identifying the leading edge or metastasizing cells of malignant glioma or to treating low-grade gliomas. This new application has the potential to benefit surgical outcomes.

Wide-field spectrally resolved quantitative fluorescence imaging system: toward neurosurgical guidance in glioma resection

In high-grade glioma surgery, tumor resection is often guided by intraoperative fluorescence imaging. 5-aminolevulinic acid-induced protoporphyrin IX (PpIX) provides fluorescent contrast between normal brain tissue and glioma tissue, thus achieving improved tumor delineation and prolonged patient survival compared with conventional white-light-guided resection. However, commercially available fluorescence imaging systems rely solely on visual assessment of fluorescence patterns by the surgeon, which makes the resection more subjective than necessary. We developed a wide-field spectrally resolved fluorescence imaging system utilizing a Generation II scientific CMOS camera and an improved computational model for the precise reconstruction of the PpIX concentration map. In our model, the tissue's optical properties and illumination geometry, which distort the fluorescent emission spectra, are considered. We demonstrate that the CMOS-based system can detect low PpIX concentration at short camera exposure times, while providing high-pixel resolution wide-field images. We show that total variation regularization improves the contrast-to-noise ratio of the reconstructed quantitative concentration map by approximately twofold. Quantitative comparison between the estimated PpIX concentration and tumor histopathology was also investigated to further evaluate the system.

Enhancement of 5-aminolevulinic acid-based fluorescence detection of side population-defined glioma stem cells by iron chelation

Cancer stem cells (CSCs) are dominantly responsible for tumor progression and chemo/radio-resistance, resulting in tumor recurrence. 5-aminolevulinic acid (ALA) is metabolized to fluorescent protoporphyrin IX (PpIX) specifically in tumor cells, and therefore clinically used as a reagent for photodynamic diagnosis (PDD) and therapy (PDT) of cancers including gliomas. However, it remains to be clarified whether this method could be effective for CSC detection. Here, using flow cytometry-based analysis, we show that side population (SP)-defined C6 glioma CSCs (GSCs) displayed much less 5-ALA-derived PpIX fluorescence than non-GSCs. Among the C6 GSCs, cells with ultralow PpIX fluorescence exhibited dramatically higher tumorigenicity when transplanted into the immune-deficient mouse brain. We further demonstrated that the low PpIX accumulation in the C6 GSCs was enhanced by deferoxamine (DFO)-mediated iron chelation, not by reserpine-mediated inhibition of PpIX-effluxing ABCG2. Finally, we found that the expression level of the gene for heme oxygenase-1 (HO-1), a heme degradation enzyme, was high in C6 GSCs, which was further up-regulated when treated with 5-ALA. Our results provide important new insights into 5-ALA-based PDD of gliomas, particularly photodetection of SP-defined GSCs by iron chelation based on their ALA-PpIX-Heme metabolism.

Drug-Induced Protoporphyria in Beagle Dogs

As part of regulatory safety testing program, a 13-week oral toxicity study with a new antipsychotic drug candidate was performed in beagle dogs. During this study, dark red/brown feces were recorded in treated dogs and increases in liver parameters (alanine aminotransferase, alkaline phosphatase, bilirubin) were measured biochemically. At the end of the study, livers of high-dose (50 mg/kg) animals were (mottled) dark brown, sometimes with pale foci. Histopathological examination of these livers showed dark globular pigment deposits in the hepatocellular cytoplasm and within the bile canaliculi. Varying numbers of inflammatory cell infiltrates were additionally present in association with the deposits. These pigment deposits showed birefringency with characteristic “Maltese Cross”-like structures under polarized light. Electronmicroscopy revealed the typical, so-called “sunburst” pattern with radiating double-lined crystalline structures. These morphologic characteristics strongly indicated at the presence of porphyrins, which was definitely confirmed biochemically. Published reports of drug-induced hepatic porphyria in dogs are rare. The possible underlying mechanism in the dog and man is discussed.

Optimization and characterization of the endogenous production of protoporphyrin IX in a yeast model

The availability of reproducible, convenient, and inexpensive model organisms able to generate predictable levels of endogenous porphyrins, including protoporphyrin IX (PpIX), is essential in photomedicine research. Saccharomyces cerevisiae produces endogenous PpIX and was used as a model organism for this study with the aim to maximize endogenous PpIX fluorescence intensity. It was found that PpIX fluorescence was significantly enhanced by administration of 5-aminolevulinic acid (ALA) and 2,2?-bipyridyl. Fluorescence intensity and spectroscopy of PpIX produced endogenously were measured in diluted yeast solutions under various conditions. The optimal protocol was: 5 ?? ? M ALA and 1 mM 2,2?-bipyridyl administered synchronously at 32°C. After 3 h, PpIX in yeast demonstrated similar steady-state and time-resolved spectroscopy as that of PpIX in DMSO. Moreover, under hypoxic conditions, the reciprocal lifetime of PpIX delayed fluorescence measured in real time was correlated to the partial pressure of oxygen ( pO 2 ) measured concomitantly with a commercially available pO 2 probe. These data show that yeast can, in optimal conditions, reproducibly generate PpIX. This is of interest in various fields such as photodiagnosis, photodynamic therapy, and photobiomodulation. Use of this model organism focuses on essential mechanisms, without the complexity of a multicellular organism.

Characterization and standardization of tissue-simulating protoporphyrin IX optical phantoms

Optical devices for measuring protoporphryin IX (PpIX) fluorescence in tissue are routinely validated by measurements in optical phantoms. Yet there exists limited data to form a consensus on the recipe for phantoms that both mimic the optical properties found in tissue and yield a reliable and stable relationship between PpIX concentration and the fluorescence remission intensity. This study characterizes the influence of multiple phantom components on PpIX fluorescence emission intensity, using Intralipid as the scattering source, bovine whole blood as the background absorber, and Tween as a surfactant to prevent PpIX aggregation. Optical measurements showed a linear proportionality (r > 0.99) between fluorescence intensity and PpIX concentration (0.1 to 10 μg/mL) over a range of Intralipid (1 to 2%) and whole blood (0.5 to 3%) for phantoms containing low surfactant (≤ 0.1%), with fluorescence intensities and scattering and absorption properties stable for 5 h after mixing. The role of surfactant in PpIX phantoms was found to be complex, as aggregation was evident in aqueous nonturbid phantoms with no surfactant (0% Tween), and avoided in phantoms containing Intralipid as the scattering source with no additional or low amounts of added surfactant (≤ 0.1% Tween). Conversely, phantoms containing higher surfactant content (>0.1% Tween) and whole blood showed interactions that distorted the fluorescence emissions.

Nature's Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells

Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature's palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa.

Determination of selected protoporphyrins in parma ham with use of 5,10,15,20-tetra(4-hydroxyphenyl)porphyrin as a surrogate standard in the recovery study

A high-performance liquid chromatographic method for the determination of hemin, protoporphyrin IX (PPIX), and zinc(II)protoporphyrin IX (Zn(II)PPIX) in Parma ham was developed. The detection was done by means of a universal DAD-detector, whereby quantification of the three naturally occurring protoporphyrins was carried out at lambda = 414 nm, i.e., very close to the respective maxima of their Soret bands. The extraction thereof from the meat matrix was done by a mixture of acetone and chloroacetic acid (100 mL + 0.2 g). Usage of 5,10,15,20-tetra(4-hydroxyphenyl)porphyrin (THPP) as a surrogate standard and its detection fixed at lambda = 444 nm, allowed to obtain accurate (ca. 96%) recovery results. Established concentrations of hemin, Zn(II)PPIX, and PPIX in the Parma ham samples were 15.97, 19.96 and 1.52 µg g(-1), respectively.

Dual-channel red/blue fluorescence dosimetry with broadband reflectance spectroscopic correction measures protoporphyrin IX production during photodynamic therapy of actinic keratosis

Dosimetry for aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photodynamic therapy of actinic keratosis was examined with an optimized fluorescence dosimeter to measure PpIX during treatment. While insufficient PpIX generation may be an indicator of incomplete response, there exists no standardized method to quantitate PpIX production at depths in the skin during clinical treatments. In this study, a spectrometer-based point probe dosimeter system was used to sample PpIX fluorescence from superficial (blue wavelength excitation) and deeper (red wavelength excitation) tissue layers. Broadband white light spectroscopy (WLS) was used to monitor aspects of vascular physiology and inform a correction of fluorescence for the background optical properties. Measurements in tissue phantoms showed accurate recovery of blood volume fraction and reduced scattering coefficient from WLS, and a linear response of PpIX fluorescence versus concentration down to 1.95 and 250 nM for blue and red excitations, respectively. A pilot clinical study of 19 patients receiving 1-h ALA incubation before treatment showed high intrinsic variance in PpIX fluorescence with a standard deviation/mean ratio of > 0.9. PpIX fluorescence was significantly higher in patients reporting higher pain levels on a visual analog scale. These pilot data suggest that patient-specific PpIX quantitation may predict outcome response.

[Photodynamic diagnosis and preoperative chemotherapy for biliary tract cancer]

BACKGROUND

Cancer cells synthesize substantial amounts of protoporphyrin IX( PPIX) from aminolevulinic acid( ALA). PPIX emits red fluorescence when illuminated under blue light. Photodynamic diagnosis (PDD), based on this phenomenon, is currently used; however, various microorganisms also show the same fluorescence with ALA when illuminated under blue light, resulting in false-positive PDD results.

PURPOSE AND METHODS

To avoid misdiagnosis, we incorporated novel systems into the PDD system. ALA, blue light (wavelength, 380-450 nm), different kinds of cell lines, and bacteria were used in this in vitro study. We used a 70% deacetylated chitosan solution (DAC-70 Sol), developed in-house, as an antibacterial agent and prepared ALA/DAC-70 Sol, used as a novel photoimaging agent. The antibacterial function of ALA/DAC-70 Sol was examined in vitro, and the photodiagnostic effects on using the novel systems were clinically evaluated using bile from patients with biliary tract cancer.

RESULTS

DAC-70 Sol demonstrated an effective bactericidal function in vitro. Red fluorescence could clearly be identified, enabling the detection of cancer cells in the bile using ALA/DAC-70 Sol.

CONCLUSIONS

Our novel systems have a great potential for use in clinical photodynamic cytodiagnosis( PDCD), which plays an important role in preoperative cancer chemotherapy.

The spectroscopy analyses of PpIX by ultrasound irradiation and its sonotoxicity in vitro

Protoporphyrin IX (PpIX) has been used as a sensitizer in photodynamic therapy (PDT) as well as in sonodynamic therapy (SDT). The photo-bleaching of PpIX has been well investigated in many experimental systems and some photo-products have also been identified in PDT. But until now, little information has been reported about the sono-damage of PpIX in SDT. So, the present study was to investigate changes of PpIX properties before and after different ultrasound treatment, and the potential interactions between PpIX, ultrasound and the irradiated cells. In cell-free system, the absorption and fluorescence spectra of PpIX in different solutions were measured by ultraviolet spectrometer and fluorescence spectrophotometer, respectively. The terephthalic acid dosimetry was applied to evaluate the efficiency of ultrasound cavitation by monitoring hydroxyl radical (OH) production on the thermolysis of H2O in the ultrasound field. In in vitro study, confocal microscopy was applied to detect the sub-cellular localization of PpIX in S180 cells before and after ultrasound exposure. Flow cytometry was used to detect the reactive oxygen species (ROS) generation during PpIX-SDT. MTT assay was performed to evaluate the cell viability of S180 cells after SDT treatment with or without ROS scavengers. The results show that PpIX displayed different spectral patterns in different solutions. PpIX was decomposed by ultrasound exposure as measured by the decreased absorption and fluorescence peak values in RPMI-1640 medium. In addition, the decomposition of PpIX was found to be simultaneously accompanied by OH production with increasing output power from ultrasound generator. PpIX at 1μg/ml significantly enhanced the ultrasound induced cavitation as measured by OH generation, and which was greatly eliminated by NaN3, histidine, mannitol, EDTA and catalase, but not by SOD. The in vitro study indicates more PpIX entered into S180 cells after ultrasound exposure. And, the extra-cellular PpIX play an important role in the enhanced cell killing of PpIX-SDT. SDT induced obvious ROS generation in S180 cells, which could be mostly inhibited by the general ROS scavenge NAC (N-acetylcysteine). Other scavengers such as NaN3, histidine, mannitol all partially prevented the SDT induced cell viability loss of S180 cells, suggesting OH, (1)O2 might be involved during the process.

White light-informed optical properties improve ultrasound-guided fluorescence tomography of photoactive protoporphyrin IX

Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX concentration, including the lowest concentration used, 0.025 μg/ml. White light spectroscopy informed optical properties, which improved fluorescence reconstruction accuracy compared to the use of fixed, literature-based optical properties, reduced reconstruction error and reconstructed fluorescence standard deviation by factors of 8.9 and 2.0, respectively. Recovered contrast-to-background error was 25% and 74% for inclusion phantoms without and with a 2-mm skin-like layer, respectively. Preliminary mouse-model imaging demonstrated system feasibility for subsurface fluorescence measurement in vivo. These data suggest that this implementation of USFT is capable of regional PpIX mapping in human skin tumors during photodynamic therapy, to be used in dosimetric evaluations.

Eggshell spottiness reflects maternally transferred antibodies in blue tits

Blue-green and brown-spotted eggshells in birds have been proposed as sexual signals of female physiological condition and egg quality, reflecting maternal investment in the egg. Testing this hypothesis requires linking eggshell coloration to egg content, which is lacking for brown protoporphyrin-based pigmentation. As protoporphyrins can induce oxidative stress, and a large amount in eggshells should indicate either high female and egg quality if it reflects the female's high oxidative tolerance, or conversely poor quality if it reflects female physiological stress. Different studies supported either predictions but are difficult to compare given the methodological differences in eggshell-spottiness measurements. Using the blue tit Cyanistes caeruleus as a model species, we aimed at disentangling both predictions in testing if brown-spotted eggshell could reflect the quality of maternal investment in antibodies and carotenoids in the egg, and at improving between-study comparisons in correlating several common measurements of eggshell coloration (spectral and digital measures, spotted surface, pigmentation indices). We found that these color variables were weakly correlated highlighting the need for comparable quantitative measurements between studies and for multivariate regressions incorporating several eggshell-color characteristics. When evaluating the potential signaling function of brown-spotted eggshells, we thus searched for the brown eggshell-color variables that best predicted the maternal transfer of antibodies and carotenoids to egg yolks. We also tested the effects of several parental traits and breeding parameters potentially affecting this transfer. While eggshell coloration did not relate to yolk carotenoids, the eggs with larger and less evenly-distributed spots had higher antibody concentrations, suggesting that both the quantity and distribution of brown pigments reflected the transfer of maternal immune compounds in egg yolks. As yolk antibody concentrations were also positively related to key proxies of maternal quality (egg volume, number, yellow feather brightness, tarsus length), eggshells with larger spots concentrated at their broad pole may indicate higher-quality eggs.

Zinc erythrocyte protoporphyrin as marker of malaria risk in pregnancy - a retrospective cross-sectional and longitudinal study

BACKGROUND

The effects of iron interventions and host iron status on infection risk have been a recurrent clinical concern, although there has been little research on this interaction in pregnant women.

METHODS

Cross-sectional and longitudinal analyses were undertaken to determine the association of whole blood zinc erythrocyte protoporphyrin (ZPP) with malaria parasitaemia in pregnant women attending antenatal and delivery care at Montfort and Chikwawa Hospitals, Shire Valley, Malawi. Prevalence of antenatal, delivery and placental malaria was assessed in relation to maternal ZPP levels. The main outcome measures were prevalence of peripheral and placental Plasmodium falciparum parasitaemia and odds ratios of malaria risk.

RESULTS

A total of 4,103 women were evaluated at first antenatal visit, of whom at delivery 1327 were screened for peripheral and 1285 for placental parasitaemia. Risk of malaria at delivery (peripheral or placental) was higher in primigravidae (p < 0.001), and lower (peripheral) with use of intermittent preventive anti-malarials during pregnancy (p < 0.001). HIV infection was associated with increased malaria parasitaemia (p < 0.02, peripheral or placental). Parasitaemia prevalence was lower in women with normal ZPP levels compared to those with raised concentrations at both first antenatal visit (all gravidae, p = 0.048, and at delivery (all gravidae, p < 0.001; primigravidae, p = 0.056). Between first antenatal visit and delivery women who transitioned from raised (at first antenatal visit) to normal ZPP values (at delivery) had lower peripheral parasitaemia prevalence at delivery compared to those who maintained normal ZPP values at both these visits (all gravidae: 0.70, 95%CI 0.4-1.1; primigravidae: 0.3, 0.1-0.8). In regression analysis this difference was lost with inclusion of HIV infection in the model.

CONCLUSIONS

Raised ZPP concentrations in pregnancy were positively associated with P. falciparum parasitaemia and were probably secondary to malaria inflammation, rather than indicating an increased malaria risk with iron deficiency. It was not possible from ZPP measurements alone to determine whether iron deficiency or repletion alters malaria susceptibility in pregnancy.

Quantitative fluorescence imaging of protoporphyrin IX through determination of tissue optical properties in the spatial frequency domain

The ability to quantitatively determine tissue fluorescence is of interest for the purpose of better understanding the details of photodynamic therapy of skin cancer. In particular, we are interested in quantifying protoporphyrin IX (PpIX) in vivo. We present a method of correcting fluorescence for effects of native tissue absorption and scattering properties in a spatially resolved manner that preserves the resolution of the fluorescence imaging system, based off a homogeneous representation of tissue. Validation was performed using a series of liquid turbid phantoms having varying concentrations of absorber, scatterer, and fluorophore (PpIX). Through the quantification of tissue optical properties via spatial frequency domain imaging, an empirical model based on Monte Carlo simulations was deployed to successfully decouple the effects of absorption and scattering from fluorescence. From this we were able to deduce the concentration of the PpIX to within 0.2 μg/ml of the known concentration. This method was subsequently applied to the determination of PpIX concentration from in vivo normal skin where the model-based correction determined a concentration of 1.6 μg/ml, which is in agreement with literature.

Combined fluorescence and reflectance spectroscopy for in vivo quantification of cancer biomarkers in low- and high-grade glioma surgery

Biomarkers are indicators of biological processes and hold promise for the diagnosis and treatment of disease. Gliomas represent a heterogeneous group of brain tumors with marked intra- and inter-tumor variability. The extent of surgical resection is a significant factor influencing post-surgical recurrence and prognosis. Here, we used fluorescence and reflectance spectral signatures for in vivo quantification of multiple biomarkers during glioma surgery, with fluorescence contrast provided by exogenously-induced protoporphyrin IX (PpIX) following administration of 5-aminolevulinic acid. We performed light-transport modeling to quantify multiple biomarkers indicative of tumor biological processes, including the local concentration of PpIX and associated photoproducts, total hemoglobin concentration, oxygen saturation, and optical scattering parameters. We developed a diagnostic algorithm for intra-operative tissue delineation that accounts for the combined tumor-specific predictive capabilities of these quantitative biomarkers. Tumor tissue delineation achieved accuracies of up to 94% (specificity = 94%, sensitivity = 94%) across a range of glioma histologies beyond current state-of-the-art optical approaches, including state-of-the-art fluorescence image guidance. This multiple biomarker strategy opens the door to optical methods for surgical guidance that use quantification of well-established neoplastic processes. Future work would seek to validate the predictive power of this proof-of-concept study in a separate larger cohort of patients.

Monte Carlo modeling of in vivo protoporphyrin IX fluorescence and singlet oxygen production during photodynamic therapy for patients presenting with superficial basal cell carcinomas

We present protoporphyrin IX (PpIX) fluorescence measurements acquired from patients presenting with superficial basal cell carcinoma during photodynamic therapy (PDT) treatment, facilitating in vivo photobleaching to be monitored. Monte Carlo (MC) simulations, taking into account photobleaching, are performed on a three-dimensional cube grid, which represents the treatment geometry. Consequently, it is possible to determine the spatial and temporal changes to the origin of collected fluorescence and generated singlet oxygen. From our clinical results, an in vivo photobleaching dose constant, β of 5-aminolaevulinic acid-induced PpIX fluorescence is found to be 14 ± 1 J/cm(2). Results from our MC simulations suggest that an increase from our typical administered treatment light dose of 75-150 J/cm(2) could increase the effective PDT treatment initially achieved at a depth of 2.7-3.3 mm in the tumor, respectively. Moreover, this increase reduces the surface PpIX fluorescence from 0.00012 to 0.000003 of the maximum value recorded before treatment. The recommendation of administrating a larger light dose, which advocates an increase in the treatment time after surface PpIX fluorescence has diminished, remains valid for different sets of optical properties and therefore should have a beneficial outcome on the total treatment effect.

Determination of time-dependent protoporphyrin IX concentration for photodynamic therapy dosimetry in a mice colon tumor model using fluorescence spectroscopy

Photodynamic therapy (PDT) is an effective treatment method for various types of invasive tumors. The efficiency of PDT treatment depends, to a great extent, on optimal dosimetry of light, the photosensitizer used, and on tissue oxygenation. Fluorescence spectroscopy can be employed for measurement of drug concentration in target tissue and can provide a basis for in vivo evaluation of treatment efficiency. We have developed an integrated system that can be used to determine photosensitizer concentration in vivo based on fluorescence measurements. In our study, we performed fluorescence measurements on colon tumors of Balb/c mice in which CT26 cells were injected subcutaneously in the right flank. 5-Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) was used as the photosensitizer. ALA was administered intraperitoneally at a dose of 200 mg/kg and PpIX fluorescence profiles were followed up to 34 h after ALA administration. Maximum fluorescence intensity was found 8 h after ALA administration. Also, we determined the relationship between PpIX concentration in colon tumor tissue of Balb/c mice and its fluorescence intensity at the peak of the spectrum (635 nm). This was used to determine the PpIX content in the target tissue as a function of time after ALA administration.

System development for high frequency ultrasound-guided fluorescence quantification of skin layers

A high frequency ultrasound-coupled fluorescence tomography system, primarily designed for imaging of protoporphyrin IX production in skin tumors in vivo, is demonstrated for the first time. The design couples fiber-based spectral sampling of the protoporphyrin IX fluorescence emission with high frequency ultrasound imaging, allowing thin-layer fluorescence intensities to be quantified. The system measurements are obtained by serial illumination of four linear source locations, with parallel detection at each of five interspersed detection locations, providing 20 overlapping measures of subsurface fluorescence from both superficial and deep locations in the ultrasound field. Tissue layers are defined from the segmented ultrasound images and diffusion theory used to estimate the fluorescence in these layers. The system calibration is presented with simulation and phantom validation of the system in multilayer regions. Pilot in-vivo data are also presented, showing recovery of subcutaneous tumor tissue values of protoporphyrin IX in a subcutaneous U251 tumor, which has less fluorescence than the skin.

Concentration of protoporphyrin IX in cancer tissues and blood in patients with colorectal cancer at early stage

OBJECTIVE

To determine the concentration difference in protoporphyrin in cancerous intestine and to discuss its application in laser-induced autofluorescence diagnosis for colorectal cancer at early stage.

METHODS

We detected the concentration of protoporphyrin IX in 30 patients with colorectal cancer and 30 control patients, as well as that in 60 cases of intestinal tissues (30 control tissues and 30 cancer tissues).

RESULTS

The concentration of blood protoporphyrin IX in patients with colorectal cancer was significantly higher than that in the controls (P<0.05). Protoporphyrin IX concentration in the cancer tissue was significantly higher than that in the control tissues (P<0.05).

CONCLUSION

That the concentration of protoporphyrin in cancerous intestine becomes abnormally high may be the material basis for spectrum intensity peak of (644.3+/-5.7) nm in laser-induced autofluorescence diagnosis for colorectal cancer at early stage.

Hereditary hepatic porphyrias in Finland

The occurrence of hepatic porphyrias--acute intermittent porphyria (AIP) and variegate porphyria (VP)--in Finland has been studied. During a period of 9 years 107 patients with AIP and 45 patients with VP were found. The prevalence of hereditary hepatic porphyrias was calculated to be 3.4 per 100 000 inhabitants. The patients belonged to 42 different families. Eighty-nine patients (59%) had had acute attacks, whereas 63 were symptomless latent cases. Precipitating factors, symptoms and excretion of porphyrins and their precursors did not significantly differ from what has been reported earlier from other parts of the world. A slight fragility of the skin on the back of the hands was noted in some 50% of VP patients. Abnormal sensitivity to sunlight could not be seen in a single case. However, about 50% of patients with VP showed an abnormal reaction when irradiated with artificial ultraviolet light. The difference in the skin symptoms in South African and Finnish VP patients is discussed.

Induction of sonodynamic effect with protoporphyrin IX on isolate hepatoma-22 cells

Sonodynamic therapy (SDT) is a potential cancer therapy based on the synergistic interactions of ultrasound and certain chemical compounds (sono-sensitizers). It has become evident that the direct sonochemical and subsequent redox reactions induced by SDT treatment can lead to apoptotic cell death. However, the detailed mechanisms are not well understood. This study sought to identify the cytotoxic effects of ultrasound-activated protoporphyrin IX (PpIX) on Hepatoma-22 cells (H22). The fluorescence microscope was used to detect the generation of mitochondrial reactive oxygen species (ROS), mitochondrial swelling and release of mitochondrial protein cytochrome c. Several distinct sonochemical effects were found after SDT treatment, including changes of cell viability (decreased to 82.6% in SDT-treated group), generation of mitochondrial ROS, mitochondrial swelling and release of cytochrome c (19.16% in SDT-treated group). These results indicated that the ultrasonically-induced cell killing effect could be enhanced by PpIX, and that the mitochondrial pathway might be involved in the cell damage process.

Biochemical and molecular diagnosis of erythropoietic protoporphyria in an Ashkenazi Jewish family

Erythropoietic protoporphyria (EPP) is a rare hereditary disorder due to a partial deficiency of ferrochelatase (FECH). The genotype of EPP patients features a mutation on one allele of the FECH gene and a common hypomorphic FECH IVS3-48c on the other allele (M/c). The resulting enzyme activity in patients is ∼35% of that in normal individuals. Ferrochelatase deficiency results in the accumulation of protoporphyrin in the skin, which is responsible for the clinical symptom of cutaneous photosensitivity in patients. In this study, we report the identification of a novel FECH mutation delT23 in an 11-member EPP family of Jewish origin. Two EPP siblings shared an identical genotype of delT23/IVS3-48c (M/c). They were both photosensitive and showed highly increased erythrocyte protoporphyrin. The genotype of the patients' mother, who did not present with any EPP clinical symptoms, was delT23/IVS3-48t (M/t). The patients' father, an offspring of consanguineous parents, was homozygous IVS3-48 c/c. He exhibited a mild photosensitivity, and an increase of 4-fold in erythrocyte protoporphyrin. His FECH mRNA amount was 71% of that of genotype t/t. It is the first reported case of an individual with c/c genotype who exhibits both biochemical and clinical indications of EPP. These results suggest that IVS3-48c is a functional variant of ferrochelatase. The clinical symptoms and biochemical abnormalities in the patients' father could be the result of an interaction between genetic and environmental factors. In addition, the frequency of IVS3-48c in the Ashkenazi Jewish population was estimated at 8%, which is similar to that in the European populations.

Kinetics and subcellular localization of 5-ALA-induced PpIX in DHL cells via two-photon excitation fluorescence microscopy

Two-photon excitation fluorescence (TPEF) microscopy was used to measure the 5-aminolevulinic acid (5-ALA)-induced PpIX fluorescence in follicular lymphoma DHL cells. Kinetics of 5-ALA-induced PpIX accumulation in DHL cells under various 5-ALA concentrations was studied. We found that during the course of continuous incubation with 5-ALA, the relationship between the DHL cell fluorescence signal and the incubation time showed a biphasic variation. Initially the PpIX signal increased with the incubation time and reached the maximal value at about 3 h, and then it decreased with time during the subsequent incubation period. By labeling the 5-ALA incubated DHL cells with different organelle-specific fluorescence probes: Rhodamine 123 (for mitochondria), DioC6(3) (for endoplasmic reticulum) and LysoTracker Green (for lysosomes) respectively, we found that 5-ALA-induced PpIX was primarily localized in endoplasmic reticulum and mitochondria; its concentration in the lysosome was much lower. The results suggested that 5-ALA could potentially be an effective photosensitizer in photodynamic purging of DHL cells. Two-photon excitation fluorescence microscope is a useful tool for studying 5-ALA-induced PpIX subcellular localization.

Fluorescence detection of protoporphyrin IX in living cells: a comparative study on single- and two-photon excitation

Photodynamic therapy (PDT) involves a combination of a lesion-localizing photosensitizer with light and has been established as a new modality for some medical indications. Much evidence has shown the correlation between subcellular localization of a photosensitizer with its photodynamic efficiency. However, the fluorescence of most photosensitizers in cells is weak and easily photobleached. We compare the effect of single-photon excitation (SPE) with that of two-photon excitation (TPE) on fluorescence detection of protoporphyrin IX (PpIX), a potent photosensitizer, in the PLC hepatoma cells in vitro. By using laser scanning confocal fluorescence microscopy, both fluorescence images and spectra of intracellular PpIX are studied with SPE of 405- and 488-nm lasers, and TPE of 800-nm femtosecond laser. The 405-nm laser is more efficient at exciting PpIX fluorescence than the 488-nm laser, but causes a considerable photobleaching of the PpIX fluorescence and induces weak autofluorescence signals of native flavins in the cells as well. The 800-nm TPE is found to significantly improve the quality of PpIX fluorescence images with negligible PpIX photobleaching and minimized endogenous autofluorescence, indicating the potential of 800-nm TPE for studying cellular localization of porphyrin photosensitizers for PDT.

A cohort study of haemoglobin and zinc protoporphyrin levels in term Zambian infants: effects of iron stores at birth, complementary food and placental malaria

OBJECTIVE

To examine zinc-protoporphyrin (ZPP) and haemoglobin levels, and to determine predictors of iron deficiency anaemia (IDA) in Zambian infants.

SUBJECTS AND METHODS

Ninety-one women and their normal birth weight (NBW) infants were followed bi-monthly during the first 6 months of life, and iron status, food intake, malaria parasitaemia and growth were monitored. At 4 months, the infants were divided into two groups, and the data were analysed according to whether or not they were exclusively breastfed.

RESULTS

Almost two-third of infants were born with low iron stores as defined by ZPP levels, and this proportion increased with age. Over 50% had developed IDA by 6 months. Exclusive breastfeeding at 4 months could be a protective factor for IDA (odds ratio (OR): 0.2; 95% confidence interval (CI): 0.0-1.1). Exclusively breastfed infants had higher haemoglobin values at 4 and 6 months (mean difference 0.6; 95% CI: 0.1-1.2 g/dl and mean difference 0.9; 95% CI: 0.2-1.7 g/dl, respectively), compared with infants with early complementary feeding. In univariate analysis, past or chronic placental malaria appeared to be a predictor of IDA at 4 and 6 months, but the significance was lost in multivariate analysis.

CONCLUSIONS

Zambian NBW infants are born with low iron stores and have a high risk to develop IDA in the first 6 months of life. Continuation of exclusive breastfeeding after 4 months is associated with a reduction of anaemia. The effect of placental malaria infection on increased risk of infant IDA could not be proven.

Macromolecular delivery of 5-aminolaevulinic acid for photodynamic therapy using dendrimer conjugates

Intracellular porphyrin generation following administration of 5-aminolaevulinic acid (5-ALA) has been widely used in photodynamic therapy. However, cellular uptake of 5-ALA is limited by its hydrophilicity, and improved means of delivery are therefore being sought. Highly branched polymeric drug carriers known as dendrimers present a promising new approach to drug delivery because they have a well-defined structure capable of incorporating a high drug payload. In this work, a dendrimer conjugate was investigated, which incorporated 18 aminolaevulinic acid residues attached via ester linkages to a multipodent aromatic core. The ability of the dendrimer to deliver and release 5-ALA intracellularly for metabolism to the photosensitizer, protoporphyrin IX, was studied in the transformed PAM 212 murine keratinocyte and A431 human epidermoid carcinoma cell lines. Up to an optimum concentration of 0.1 mmol/L, the dendrimer was significantly more efficient compared with 5-ALA for porphyrin synthesis. The intracellular porphyrin fluorescence levels showed good correlation with cellular phototoxicity following light exposure, together with minimal dark toxicity. Cellular uptake of the dendrimer occurs through endocytic routes predominantly via a macropinocytosis pathway. In conclusion, macromolecular dendritic derivatives are capable of delivering 5-ALA efficiently to cells for sustained porphyrin synthesis.

Iron deficiency and anemia: disparity exists between children in American Samoa and children living within the US

BACKGROUND/OBJECTIVES

Healthy People 2010 emphasizes elimination of health disparity and improvements in anemia and iron deficiency (ID). The study purpose was to (1) determine the prevalence of anemia, ID and ID anemia (IDA) in children living in American Samoa and (2) compare the prevalence to that found in children living in the United States.

SUBJECTS/METHODS

A total of 211 children from American Samoa, aged 1-5 years of age, participated in this cross-sectional study. Prevalence of anemia, ID and IDA were determined and comparison made using data obtained from children living in the United States. Anemia was diagnosed as hemoglobin (Hb) <110.0 g/l, ID as erythrocyte protoporphyrin (EP) >70 mumol/mol heme and IDA as Hb <110.0 g/l and EP >70 mumol/mol heme.

RESULTS

Anemia, ID and IDA prevalence was 33, 70 and 33%, respectively. The results of children from the United States were as follows: anemia, 9%; ID, 10% and IDA, 2%. Within American Samoan children, ID is positively associated with being breastfed <6 months (P<0.05) and anemia and IDA with lower household income (P<0.05; P<0.01). Mean Hb was significantly lower (P<0.001) and mean EP was significantly higher (P<0.001) than those within children living in the United States.

CONCLUSION

To meet Healthy People 2010 goals in children aged 1-2 years, the prevalence of ID in children living in American Samoa would need to decrease from 83 to 5% and in children aged 3-5 years from 59 to 1%. It is critical to ensure that populations within the United States and its territories are provided appropriate resources to promote health and prevent disease.

Quantitative spectroscopic analysis of 5-aminolevulinic acid-induced protoporphyrin IX fluorescence intensity in diffusely infiltrating astrocytomas

The fluorescence of protoporphyrin IX (PpIX) induced endogenously by 5-aminolevulinic acid (5-ALA) administration has recently been used for the intraoperative visualization of glioma tissues. To increase the sensitivity of photodetection, the emission spectra of 5-ALA-induced PpIX fluorescence was quantitatively measured in tissues taken from six cases of en bloc resected diffusely infiltrating astrocytomas (2 diffuse astrocytomas, 2 anaplastic astrocytomas, and 2 glioblastomas), and the correlation assessed between the fluorescence intensity and histological features. A total of 65 slices were analyzed by ex vivo spectroscopy. The ratio of the peak emission intensity to reflected excitation intensity or fluorescence intensity ratio was less than 0.001 for all 36 non-tumor tissues. The tissues with glioblastoma morphology had a fluorescence intensity ratio in excess of 0.090. The spectroscopic fluorescence intensity was positively correlated with the MIB-1 labeling index as an indicator of proliferation activity, the CD31-microvessel density as a pan-endothelial marker, and the vascular endothelial growth factor expression as an angiogenetic factor. The MIB-1 proliferation index was the most powerful determinant, suggesting that higher cell proliferation may govern preferential PpIX accumulation in glioma cells. This preliminary study suggests that spectroscopic analysis may be useful for optimizing the removal of diffuse gliomas.

Comparison between sonodynamic effect with protoporphyrin IX and hematoporphyrin on sarcoma 180

PURPOSE

The comparison between sonodynamic antitumor effect with protoporphyrin IX (PPIX) and hematoporphyrin (Hp) at a concentration of 5 mg/kg on Sarcoma 180 (S180) cells was studied in vivo, and the potential cell damage mechanism was also investigated.

METHODS

The sonodynamically induced anti-tumor effect of PPIX was studied in mice bearing S180 solid tumors. In order to determine the optimum timing of ultrasound exposure after administration of PPIX, the PPIX concentrations in plasma, skin, muscle and tumor were determined by the fluorescence intensity of tissue extractions with a fluorescence spectrophotometer based on the standard curve. Anti-tumor effects were estimated by measuring the tumor size and the tumor weight. Additionally, the morphological changes of S180 cells were evaluated by transmission electron microscope (TEM) observation immediately after sonodynamic therapy (SDT) treatment.

RESULTS

A time of 24 h after the intravenous administration of PPIX was chosen as the best time for ultrasound exposure. The antitumor effect induced by PPIX mediated sonodynamic therapy (PPIX-SDT) was in a dose dependent manner when ultrasound intensity was at or above the inertial cavitation threshold (5 W/cm(2)). A significant tumor growth delay was observed both in PPIX mediated sonodynamic therapy and in Hp mediated sonodynamic therapy treatments (Hp-SDT), and the tumor weight inhibition ratios after the synergistic treatments were 42.82 +/- 0.03 and 35.22 +/- 0.03%, respectively, this difference was significant at P < 0.05. While ultrasound alone (5 W/cm(2)) showed a slight tumor growth inhibitory effect compared with the control group, and PPIX or Hp alone showed almost no significant effect. Furthermore, TEM observation indicated cell damage was more serious in PPIX-SDT treatment group than in Hp-SDT treatment group. After sonication, the cell ultra-structure such as cell membrane destruction, mitochondria swelling, chromatin condensation might be important factors that inhibited the tumor growth and even induced cell death.

CONCLUSIONS

The comparative results suggested that PPIX as a sonosensitizer might have more potential cytotoxicity than Hp when irradiated with ultrasound, and the ultra-structural changes may account for cell destruction induced by sonodynamic therapy in our experiment mode.

Proteins of insoluble matrix of avian (gallus gallus) eggshell

The protein composition of the insoluble avian eggshell matrix was studied. The determination of these proteins insoluble in water (EDTA-insoluble) was carried out using enzymatic cleavage followed by a high-performance liquid chromatography-mass spectrometry method. The influence of various enzymes on the protein splitting also was studied. The distribution of proteins depends on the type of layer (localization within the eggshell): ovocalyxin-32 was found mainly in the outer layer (the cuticle); ovocleidin-116 and 17 and ovocalyxin-36 were found throughout the whole eggshell, whereas ovalbumin was only found in the inner layer, the mammillary. The pigment (protoporphyrin IX) was mainly found in the cuticle and is incorporated into the protein network.

Active photosensitizers in butter detected by fluorescence spectroscopy and multivariate curve resolution

In this study, fluorescence excitation and emission matrices and multivariate curve resolution (PARAFAC) were used to detect and characterize active photosensitizers spectrally in butter. Butter samples were packed under high (air) and low oxygen (<0.05%) atmospheres and exposed to violet, green, or red light. Six photosensitizers were found: riboflavin, protoporphyrin, hematoporphyrin, a chlorophyll a-like molecule, and two unidentified tetrapyrrols. By estimation of relative concentrations, we could follow how each sensitizer was photodegraded as function of wavelength, oxygen level, and time. The degradation rate of protoporphyrin, hematoporphyrin, chlorophyll a, and one of the tetrapyrrols correlated well (0.83-0.91) with the formation of sensory measured oxidation. The results suggest that mainly type I photoreactions were responsible for the degradation of photosensitizers in both high and low oxygen atmosphere. Type II photoreactions (generation of singlet oxygen) were involved in the oxidation of butter stored in air. The study shows that PARAFAC modeling of fluorescence landscapes is an excellent tool for studying photooxidation in complex systems.

Fractionated illumination after topical application of 5-aminolevulinic acid on normal skin of hairless mice: The influence of the dark interval

We have previously shown that light fractionation during topical aminolevulinic acid based photodynamic therapy (ALA-PDT) with a dark interval of 2h leads to a significant increase in efficacy in both pre-clinical and clinical PDT. However this fractionated illumination scheme required an extended overall treatment time. Therefore we investigated the relationship between the dark interval and PDT response with the aim of reducing the overall treatment time without reducing the efficacy. Five groups of mice were treated with ALA-PDT using a single light fraction or the two-fold illumination scheme with a dark interval of 30 min, 1, 1.5 and 2h. Protoporphyrin IX fluorescence kinetics were monitored during illumination. Visual skin response was monitored in the first seven days after PDT and assessed as PDT response. The PDT response decreases with decreasing length of the dark interval. Only the dark interval of 2h showed significantly more damage compared to all the other dark intervals investigated (P<0.05 compared to 1.5h and P<0.01 compared to 1h, 30 min and a single illumination). No relationship could be shown between the utilized PpIX fluorescence during the two-fold illumination and the PDT response. The rate of photobleaching was comparable for the first and the second light fraction and not dependent of the length of dark interval used. We conclude that in the skin of the hairless mouse the dark interval cannot be reduced below 2h without a significant reduction in PDT efficacy.

A study comparing endogenous protoporphyrin IX induced by 5-ALA and ALA-methyl ester with exogenous PpIX and PpIX dimethyl ester in photodynamic diagnosis of human nasopharyngeal carcinoma xenografts

5-Aminolevulinic acid (5-ALA) and its esters have been under intense investigation to enhance the endogenous production of protoporphyrin IX (PpIX) in tumour cells for the purpose of photodynamic diagnosis. In this study we have investigated the use of exogenous PpIX and its dimethyl ester (PME) and compared the results with endogenous PpIX produced via 5-ALA and ALA methyl ester (AME) in poorly differentiated NPC/CNE-2 nasopharyngeal carcinoma cells in both in vivo and in vitro systems. All prodrugs and photosensitizers were administered to tumour bearing balb/c nude mice either intravenously or topically. in vitro results show that 5-ALA induced more PpIX fluorescence when compared with AME in NPC/CNE-2 cells and PME showed better uptake than PpIX. in vivo results show that exogenous PpIX and PME show promise as good candidates as photosensitizers for photodynamic diagnosis as they exhibit significant selectivity between tumour tissue and normal tissue at 3 h. Modification of delivery vehicle used for application of exogenous PpIX and PME could allow for rapid uptake; better selectivity and localization of the photosensitizer.

Lead poisoning as a result of infertility treatment using herbal remedies

INTRODUCTION

Lead poisoning remains a major problem in our society due to the lack of awareness of its ill effects among the clinical community. The non-availability of blood lead levels at primary health centers results in many lead-poisoned cases being treated symptomatically, without the diagnosis being sought.

CASE REPORT

We report a case here, presenting with colicky abdominal pain receiving symptomatic treatment initially; lead poisoning was confirmed following the estimation of blood lead levels.

DISCUSSION

The consumption of unbranded herbal medicines as a causative factor for lead poisoning was confirmed by high lead content in the medicines. Surely, this demands public health programs to disseminate strategies to the medical personnel about the clinical implication of lead poisoning, as well as the general public for awareness and to prevent lead poisoning.

Griseofulvin enhances the effect of aminolevulinic acid-based photodynamic therapy in vitro

OBJECTIVE

In this study, we investigated whether or not griseofulvin (GF), which is an antimycotic widely used for the oral treatment of skin fungal infections, enhanced the effect of aminolevulinic acid-based photodynamic therapy (ALA-PDT) in vitro, using several tumor cell lines.

METHODS

A human squamous cell carcinoma line (KB), two human osteosarcoma cell lines from mandible (HOSM-1, HOSM-2), and the human gingiva-derived fibroblast line (HF), representing normal cells, were used. GF enhancement of ALA-PDT was evaluated by comparing the effect of ALAin combination with GF to the effect of ALAalone (GF enhancement rate of ALA-PDT). Also, the effect of GF on intracellular accumulation of protoporphyrin IX (PpIX) was evaluated by comparing the intracellular accumulation of PpIX in the ALA and GF combined treatment with that of ALA treatment alone (pGF enhancement rate of intracellular PpIX).

RESULTS

GFenhancement rate of ALA-PDT was 2.51 in KB cells, and 1.65 and 1.27 in HOSM-1 and HOSM-2 cells, respectively. GF enhancement rates of intracellular PpIX were 1.94 in KB cells, 1.53 in HOSM-1 cells, and 1.19 in HOSM-2 cells. GF enhancement rate of intracellular PpIX followed the same trends as the levels of GF enhancement rate of ALA-PDT in the different cell types. For HF, a large effect was not revealed in this study.

CONCLUSION

The present study, although preliminary, strongly suggests that concomitant treatment with ALAand GF may be very useful to enhance the effect of ALA-PDT.

Fluorescence spectroscopy combined with 5-aminolevulinic acid-induced protoporphyrin IX fluorescence in detecting oral premalignancy

BACKGROUND

Early detection of premalignant/malignant lesions in the oral cavity can certainly improve the patient's prognosis. This study presents fluorescence imaging with the topical application of 5-aminolevulinic as a way to improve detection of various oral tissue pathologies. This procedure depends mainly on comparing the intensity of red and green fluorescence emitted from tissues during examination.

MATERIALS AND METHODS

Seventy-one patients who presented with clinically suspicious oral leukoplakia were recruited for this study. Each of the patients was required to have 5-aminolevulinic acid in the form of mouth rinse prior to fluorescence imaging. Following this a surgical biopsy was acquired from the exact examination site. The results of the fluorescence spectroscopy have been compared with histopathology.

RESULTS

A Student's t-test was applied to test the viability of the ratio between red and green fluorescence. The red-to-green ratio was found to increase significantly when the lesion was identified as dysplastic or carcinoma in situ. By applying a threshold line to discriminate between normal and dysplastic lesions; a sensitivity of 83-90% and specificity of 79-89% were obtained.

CONCLUSION

Fluorescence spectroscopy combined with 5-aminolevulinic acid-induced protoporphyrin IX was found as a valuable tool in the diagnosis of oral premalignancy. This technique offers the potential to be advantageous over other non-optical techniques in terms of providing real-time diagnosis, in situ monitoring, cost effectiveness and more tolerated by patient compared to surgical biopsy.

Three-dimensional model of the human aromatase enzyme and density functional parameterization of the iron-containing protoporphyrin IX for a molecular dynamics study of heme-cysteinato cytochromes

Mammalian cytochromes P450 (CYP) are enzymes of great biological and pharmaco-toxicological relevance. Due to their membrane-bound nature, the structural characterization of these proteins is extremely difficult, and therefore computational techniques, such as comparative modeling, may help obtaining reliable structures of members of this family. An important feature of CYP is the presence of an iron-containing porphyrin group at the enzyme active site. This calls for quantum chemical calculations to derive charges and parameters suitable for classical force field-based investigations of this proteins family. In this report, we first carried out density functional theory (DFT) computations to derive suitable charges for the Fe2+-containing heme group of P450 enzymes. Then, by means of the homology modeling technique, and taking advantage of the recently published crystal structure of the human CYP2C9, we built a new model of the human aromatase (CYP19) enzyme. Furthermore, to study the thermal stability of the new model as well as to test the suitability of the new DFT-based heme parameters, molecular dynamics (MD) simulations were carried out on both CYP2C9 and CYP19. Finally, the last few ns of aromatase MD trajectories were investigated following the essential dynamics protocol that allowed the detection of some correlated motions among some protein domains.

Topical 5-Aminolevulinic Acid Mediated Photodynamic Therapy of Superficial Basal Cell Carcinoma Using Two Light Fractions with a Two-hour Interval: Long-term Follow-up

Photodynamic therapy (PDT) of superficial basal cell carcinoma using topical 5-aminolaevulinic acid (ALA) and 75-100 J/cm2 light dose yields unsatisfactory long-term results. In several animal models, illumination with two light fractions approximately 2 h apart was considerably more effective than single illumination, suggesting the need for a pilot clinical study. Fifteen patients with a total of 86 primary superficial basal cell carcinomas, received topical ALA and were illuminated 4 and 6 h later, both with 45 J/cm2 laser light (633+/-1 nm). Fluorescence spectra were measured before and immediately after each illumination. At a mean follow-up of 59 months (range 44-82), 67 lesions could be evaluated, 56 of which showed a complete response (84%). Cosmesis was good/excellent in 88% of the complete response group and fair in 12%. There was no correlation between protoporphyrin fluorescence and response, but a significant correlation between the percentage of fluorescence left after photobleaching by the first illumination and the amount of protoporphyrin re-synthesized 2 h later. In conclusion, the long-term complete remission rate of fractionated ALA-mediated PDT of superficial basal cell carcinoma as reported here is significantly better than after PDT with single illumination previously reported by others, but equal to studies using single illumination with a much higher light fluence. Further improvement may be possible by reducing the fluence of the first fraction, with constant total fluence.

Enhanced porphyrin accumulation using dendritic derivatives of 5-aminolaevulinic acid for photodynamic therapy: An in vitro study

Intracellular porphyrin generation following administration of 5-aminolaevulinic acid has been widely used in photodynamic therapy for a range of malignant and certain non-malignant lesions. However, cellular uptake of 5-aminolaevulinic acid is limited by its hydrophilic nature and improved means of delivery are therefore being sought. Highly branched polymeric drug carriers known as dendrimers are a promising new approach to drug delivery. The aim of this study was to investigate the efficacy of dendrimers conjugated with 5-aminolaevulinic acid for porphyrin production in the transformed PAM 212 keratinocyte cell line and skin explants. Each dendritic derivative incorporated three 5-aminolaevulinic acid residues which were conjugated as esters via methyl or propyl linkers to a central tertiary carbon whose remaining terminal bore an amino, aminobenzyloxycarbonyl or nitro group. In the cell line, all compounds were more efficient at low concentrations compared to equimolar 5-aminolaevulinic acid for porphyrin production, with the most efficient incorporating the longer propyl linker. This compound was also the most lipophilic according to partition coefficient measurements. The intracellular porphyrin fluorescence levels showed good correlation with cellular phototoxicity following light exposure for all the compounds, together with minimal dark toxicity. Our findings indicate that the key factors influencing the efficacy of the dendritic derivatives are lipophilicity and steric hindrance within the dendritic structure which could restrict access to intracellular esterases for liberation of 5-aminolaevulinic acid. These findings should be taken into account in the design of larger dendrimers of 5-aminolaevulinic acid.

Lipid cubic phases for improved topical drug delivery in photodynamic therapy

We have evaluated the efficacy of lipid cubic phases, highly ordered self-assembly systems on the nanometer level, as drug delivery vehicles for in vivo topical administration of delta-aminolevulinic acid (ALA) and its methyl ester (m-ALA) on nude mice skin. ALA, a precursor of heme, induces the production of the photosensitizer protoporphyrin IX (PpIX) in living tissue. Measuring the PpIX fluorescence at the skin surface, after topical administration, makes indirect quantification of the penetration of ALA into the tissue possible. Cubic phases were formed of lipid (monoolein or phytantriol), water and drug. In some cases, propylene glycol was included in the cubic phase as well. The drug concentration was 3% (w/w, based on the total sample weight) in all investigated vehicles. When the formulations were applied for 1 h, the monoolein cubic systems and the three-component phytantriol sample showed higher fluorescence compared to the standard ointment during the 10 h of measurement. Both ALA and m-ALA yielded similar results, although the differences between the investigated vehicles were more pronounced when using m-ALA. For the 24-h applications, the monoolein cubic systems with m-ALA showed faster PpIX formation than the standard ointment, implying higher PpIX levels at short application times (less than 4 h). The systemic PpIX fluorescence of ALA was elevated by using the lipid cubic formulations. Notably, a small systemic effect was also observed for the monoolein cubic sample with m-ALA. These results imply improved PpIX formation when using the lipid cubic systems, most probably due to enhanced drug penetration.

A Chilean boy with severe photosensitivity and finger shortening: the first case of homozygous variegate porphyria in South America

A 7-year-old Chilean boy presented with severe photosensitivity, blistering, erosions and scarring on sun-exposed areas of the body since the age of 6 months. Additionally, he showed a short stature and shortening of the fingers. Laboratory examination revealed greatly elevated protoporphyrin levels in the blood. Such biochemical findings can be observed in homozygous variants of usually autosomal dominantly inherited acute porphyrias such as variegate porphyria (VP) and hereditary coproporphyria, which usually do not become manifest before the second or third decade of life in heterozygotes. Using polymerase chain reaction-based techniques we identified a missense mutation in exon 7 on the paternal allele and a frameshift mutation in exon 13 on the maternal allele of the protoporphyrinogen oxidase gene that harbours the mutations underlying VP. This is the first homozygous case of VP in South America. As VP represents the most frequent type of acute porphyria not only in Chile but also in South Africa, more such cases could be expected in the future, particularly because a founder mutation for this disease has already been described in the Chilean and South African population.

Expression pattern and intensity of protoporphyrin IX induced by liposomal 5-aminolevulinic acid in rat pilosebaceous unit throughout hair cycle

We have developed liposomal formulation of 5-aminolevulinic acid (ALA) to enhance topical delivery and examined ALA-induced protoporpyrin (PpIX) expression in rat pilosebaceous unit throughout hair cycle. Two types of liposomes--glycerol dilaulate (GDL) and phosphatidylcholine (PC)--were formulated and both liposomal ALA increased PpIX expression in rat dorsal skin and pilosebaceous units when compared with free ALA. However, iontophoresis combined with liposomal ALA reduced the expression intensity of PpIX in hair bulbs although it achieved deeper and wider expression of PpIX through transfollicular pathway. After topical application in intact or depilated rat skin, liposomal ALA produced excellent PpIX expression in pilosebaceous units. The expression pattern and intensity of PpIX changed in hair cycle-dependent manner: specific expression only in sebaceous glands was observed at telogen; strong expression in whole pilosebaceous units was shown at anagen with intense expressions in hair bulbs and sebaceous glands; and a pattern similar to anagen but reduced intensity in the hair bulbs was seen at catagen. Throughout hair cycle, the expression pattern and intensity were dramatically changed in hair follicular epithelial cells depending on the cell density and proliferation activity of those cells, whereas those were consistent in sebaceous glands regardless of hair cycle. Little expression was shown in dermis. Photoactivation effect of 20% liposomal ALA-PDT using a red filtered-halogen lamp damaged sebaceous glands, hair follicles and epidermal layers. Formation of a thicker epidermal layer was observed, and hair induction after depilation was inhibited along with damage in sebaceous glands.