Evaluating aroma quality of black tea by an olfactory visualization system: Selection of feature sensor using particle swarm optimization.

Aroma is an important index to evaluate the quality and grade of black tea. This work innovatively proposed the sensory evaluation of black tea aroma quality based on an olfactory visual sensor system. Firstly, the olfactory visualization system, which can visually represent the aroma quality of black tea, was assembled using a lab-made color sensitive sensor array including eleven porphyrins and one pH indicator for data acquisition and color components extraction. Then, the color components from different color sensitive spots were optimized using the particle swarm optimization (PSO) algorithm. Finally, the back propagation neural network (BPNN) model was developed using the optimized characteristic color components for the sensory evaluation of black tea aroma quality. Results demonstrated that the BPNN models, which were developed using three color components from FTPPFeCl (component G), MTPPTE (component B) and BTB (component B), can get better results based on comprehensive consideration of the generalization performance of the model and the fabrication cost of the sensor. In the validation set, the average of correlation coefficient (RP) value was 0.8843 and the variance was 0.0362. The average of root mean square error of prediction (RMSEP) was 0.3811 and the variance was 0.0525. The overall results sufficiently reveal that the optimized sensor array has promising applications for the sensory evaluation of black tea products in the process of practical production.

Structural analysis of small to medium-sized molecules by mass spectrometry after electron-ion fragmentation (ExD) reactions.

Electron capture dissociation (ECD) is a tandem mass spectrometry (MS/MS) method that utilizes the interaction of ions and electrons. Its unique ability to preserve labile bonds distinguishes it from conventional threshold-based MS/MS methods, the most important of which is collision-induced dissociation (CID). During the last decade, ECD has opened up several new venues in protein analyses, for example top-down sequencing, identification of post-translational modifications, and characterization of protein-protein interactions. In recent years, a number of related dissociation techniques, so-called ExD techniques, particularly electron transfer dissociation (ETD), electron detachment dissociation (EDD), electron induced dissociation (EID), and negative electron transfer dissociation (NETD), have emerged and have extended the application range of ion-electron dissociations further. Importantly, ExD techniques have been applied beyond protein analyses, which is the focus of the current paper. This short introduction describes the application of ExD to small and medium-sized molecules and reviews important applications to natural products, biomedical compounds, synthetic molecules, crude oils, and environmental toxins.

NMR-Based Metabolomic Study on Isatis tinctoria: Comparison of Different Accessions, Harvesting Dates, and the Effect of Repeated Harvesting.

Isatis tinctoria is an ancient dye and medicinal plant with potent anti-inflammatory and antiallergic properties. Metabolic differences were investigated by NMR spectroscopy of accessions from different origins that were grown under identical conditions on experimental plots. For these accessions, metabolite profiles at different harvesting dates were analyzed, and single and repeatedly harvested plants were compared. Leaf samples were shock-frozen in liquid N2 immediately after being harvested, freeze-dried, and cryomilled prior to extraction. Extracts were prepared by pressurized liquid extraction with ethyl acetate and 70% aqueous methanol. NMR spectra were analyzed using a combination of different methods of multivariate data analysis such as principal component analysis (PCA), canonical analysis (CA), and k-nearest neighbor concept (k-NN). Accessions and harvesting dates were well separated in the PCA/CA/k-NN analysis in both extracts. Pairwise statistical total correlation spectroscopy (STOCSY) revealed unsaturated fatty acids, porphyrins, carbohydrates, indole derivatives, isoprenoids, phenylpropanoids, and minor aromatic compounds as the cause of these differences. In addition, the metabolite profile was affected by the repeated harvest regime, causing a decrease of 1,5-anhydroglucitol, sucrose, unsaturated fatty acids, porphyrins, isoprenoids, and a flavonoid.

Dialysis-associated pseudoporphyria successfully treated with vitamin D. Report of two cases.

Pseudoporphyria refers to a rare bullous dermatosis characterized by the clinical and histological features of porfiria cutanea tarda without abnormalities in porphyrin metabolism. The pathogenesis is heterogeneous and several exogenous factors may promote the bullous lesion formation, including medications, end stage renal disease, dialysis and tanning beds. Regarding treatment of this condition, in literature different therapy have been reported, such as glutathione and his precursor N-acetylcysteine, which presents anti-oxidant properties; however even more toxic drugs, such as chloroquine, are used. Moreover, in patients with drug-induced PP discontinuation of the offending agent, if possible, is a crucial aspect of the clinical management. We report two cases of dialysis patients presenting blisters on extremities, which healed with the avoidance of UV exposure and oral Vitamin D supplementation. Interestingly Vitamin D despite the lack of antioxidant properties led to a completely resolution of PP in both our patients within 30 days. A possible explanation of this finding is that Vitamin D, playing a key role in the regulation of serum Ca2+, can modulated cadherin-cadherin interactions and led to healing of pseudoporphyria bullous lesions. Finally we highlight the prominent role of UV-exposure in PP elicitation thus a good photoprotection is essential for all patients with pseudoporphyria.

The effect of blue light on periodontal biofilm growth in vitro.

We have previously shown that blue light eliminates the black-pigmented oral bacteria Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Prevotella melaninogenica. In the present study, the in vitro photosensitivity of the above black-pigmented microorganisms and four Fusobacteria species (Fusobacterium nucleatum ss. nucleatum, F. nucleatum ss. vincentii, F. nucleatum ss. polymorphum, Fusobacterium periodonticum) was investigated in pure cultures and human dental plaque suspensions. We also tested the hypothesis that phototargeting the above eight key periodontopathogens in plaque-derived biofilms in vitro would control growth within the dental biofilm environment. Cultures of the eight bacteria were exposed to blue light at 455 nm with power density of 80 mW/cm2 and energy fluence of 4.8 J/cm2. High-performance liquid chromatography (HPLC) analysis of bacteria was performed to demonstrate the presence and amounts of porphyrin molecules within microorganisms. Suspensions of human dental plaque bacteria were also exposed once to blue light at 455 nm with power density of 50 mW/cm2 and energy fluence of 12 J/cm2. Microbial biofilms developed from the same plaque were exposed to 455 nm blue light at 50 mW/cm2 once daily for 4 min (12 J/cm2) over a period of 3 days (4 exposures) in order to investigate the cumulative action of phototherapy on the eight photosensitive pathogens as well as on biofilm growth. Bacterial growth was evaluated using the colony-forming unit (CFU) assay. The selective phototargeting of pathogens was studied using whole genomic probes in the checkerboard DNA-DNA format. In cultures, all eight species showed significant growth reduction (p < 0.05). HPLC demonstrated various porphyrin patterns and amounts of porphyrins in bacteria. Following phototherapy, the mean survival fractions were reduced by 28.5 and 48.2% in plaque suspensions and biofilms, respectively, (p < 0.05). DNA probe analysis showed significant reduction in relative abundances of the eight bacteria as a group in plaque suspensions and biofilms. The cumulative blue light treatment suppressed biofilm growth in vitro. This may introduce a new avenue of prophylactic treatment for periodontal diseases.

Discrimination of Chinese green tea according to varieties and grade levels using artificial nose and tongue based on colorimetric sensor arrays.

Colorimetric artificial tongue and nose were used to discriminate nine Chinese green teas from different geographical origins and grade levels. Printing nanoporous porphyrin, dimeric metalloporphyrins, metallosalophen complexes and chemically responsive dyes on a hydrophobic membrane, the developed sensor array of artificial tongue and nose showed a unique pattern of colorimetric change upon exposure to green tea liquids or gases. All green tea samples, both in liquid and gas analysis, gave distinct patterns according to geographical origin and grade level, thus resulting in their facile identification. The good reproducibility of colorimetric artificial tongue and nose was proved. Data analysis was performed by chemometric techniques: hierarchical cluster analysis (HCA), and principal component analysis (PCA). Chinese green tea from the same geographical origin could cluster together in PCA score plot. No errors in classification by HCA were observed in 90 trials. The colorimetric artificial tongue and nose can be used to discriminate Chinese green tea according to geographical origin and grade level.

Sodiation as a tool for enhancing the diagnostic value of MALDI-TOF/TOF-MS spectra of complex astaxanthin ester mixtures from Haematococcus pluvialis.

The microalga Haematococcus pluvialis produces the pigment astaxanthin mainly in esterified form with a multitude of fatty acids, which results in a complex mixture of carotenol mono- and diesters. For rapid fingerprinting of these esters, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/TOF-MS) might be an alternative to traditional chromatographic separation combined with MS. Investigation of ionization and fragmentation of astaxanthin mono- and diester palmitate standards in MALDI-TOF/TOF-MS showed that sodium adduct parent masses [M + Na](+) gave much simpler MS(2) spectra than radical / protonated [M](+●) / [M + H](+) parents. [M + Na](+) fragments yielded diagnostic polyene-specific eliminations and fatty acid neutral losses, whereas [M](+●) / [M + H](+) fragmentation resulted in a multitude of non-diagnostic daughters. For diesters, a benzonium fragment, formed by polyene elimination, was required for identification of the second fatty acid attached to the astaxanthin backbone. Parents were forced into [M + Na](+) ionization by addition of sodium acetate, and best signal-to-noise ratios were obtained in the 0.1 to 1.0 mM range. This method was applied to fingerprinting astaxanthin esters in a crude H. pluvialis extract. Prior to MALDI-TOF/TOF-MS, the extract was fractionated by normal phase Flash chromatography to obtain fractions enriched in mono- and diesters and to remove pheophytin a, which compromised monoester signals. All 12 types of all-trans esterified esters found in LC were identified with MALDI-TOF/TOF-MS, with the exception of two minor monoesters.

Hexagonal class representation for fingerprinting and facile comparison of petroleomic samples.

Because of the high complexity of petroleomic-type samples, there is a need for efficient ways of visualizing and interpreting the resulting data in mass spectrometry-based petroleomics. Over the years, several graphing approaches have become widespread, yet they mostly deal with a particular subset of compounds detected within a given sample. Here, we present an alternative and complementary sample visualization method, the hexagonal class representation, based on relative abundance vs compound classes plot. The representation can be used to "fingerprint" a petroleomic-type sample, provide a simple means of sample comparison, as well as allow for a fast overview and detection of any compound of interest based on its elemental composition and chemical properties.

A valuable visual colorimetric and electrochemical biosensor for porphyrin.

Porphyrin is able to specifically combine with phosphorus, thus a novel bifunctional sensing platform for determination of porphyrin by visual colorimetry and electrochemistry was demonstrated. A pretreated gold sheet (or electrode) with 2-mercatpoethanol (2-ME) was chemically modified by POCl(3) to obtain the surface phosphate active sites. The different stages of modified electrode were characterized by electrochemical impedance spectroscopy (EIS). The 1:1 cationic sitting-atop (SAT) complex P(V)-porphyrin was formed due to the high affinity of the modified gold sheet (or electrode) towards the porphyrin, resulting in electron transfer resistance increase of the electrode surface. Meanwhile, a dramatic color changing from burgundy to dark green of porphyrin solution was observed with the naked-eye within 3s. What's more, this was reflected by the notable change of the Soret band of porphyrin when using UV-vis. Two sensing systems provide different sensitivity for porphyrin analysis. With visual colorimetry, porphyrin can be detected at a level of 1.0×10(-6) M, whereas the detection limit of porphyrin is 3.0×10(-8) M using the EIS method. The practical application of the sensor to determination of pheophytin which was obtained from fresh spinach leaves has been accomplished. The results demonstrate the facility and effectivity of our introduced bifunctional biosensor for quantitative analysis of porphyrin.

A comprehensive metabolite profiling of Isatis tinctoria leaf extracts.

A broad-based characterisation of a pharmacologically active dichloromethane extract from Isatis tinctoria leaves was carried out. For a comprehensive picture we also included the polar constituents of I. tinctoria (MeOH extract) and for comparative purposes, the taxonomically closely related plant I. indigotica. Diode array detector, evaporative light scattering detector, atmospheric pressure chemical ionisation and electrospray ionisation mass spectrometry, and electrospray ionisation time-of-flight mass spectrometry detectors were used in parallel to ensure a wide coverage of secondary metabolites with highly diverging analytical properties. Off-line microprobe nuclear magnetic resonance spectroscopy after peak purification by semi-preparative high-pressure liquid chromatography served for structure elucidation of some minor constituents. More than 65 compounds belonging to various structural classes such as alkaloids, flavonoids, fatty acids, porphyrins, lignans, carotenoids, glucosinolates and cyclohexenones were unambiguously identified, and tentative structures were proposed for additional compounds. Numerous compounds were identified for the first time in the genus Isatis, and an indolic alkaloid was discovered.

Porfiria cutánea tarda en una paciente hemodializada / Porphyria cutanea tarda in a dialyzed female patient

Las alteraciones dermatológicas constituyen un hallazgo frecuente en los pacientes con insuficiencia renal. La porfiria cutánea tarda, la pseudoporfiria, la fototoxicidad o enfermedades ampollosas concurrentes pueden ocasionar la aparición de lesiones de contenido líquido en pacientes en hemodiálisis. Describimos el caso de una paciente en hemodiálisis que desarrolló lesiones ampollosas. Los hallazgos clínicos y de laboratorio eran inicialmente compatibles con la sospecha de pseudoporfiria, pero el hallazgo de unos niveles francamente elevados de porfirinas en suero, orina y heces confirmó el diagnóstico de porfiria cutánea tarda. La porfiria cutánea tarda y la pseudoporfiria presentan manifestaciones clínicas comunes. Sin embargo, los valores de porfirinas en plasma, orina y heces en la pseudoporfiria se encuentran normales o ligeramente elevados

Dermatological disorders are a frequent finding in patients with renal insufficiency. Porphyria cutanea tarda, pseudoporphyria, phototoxicity or concurrent bullous diseases may cause the appearance of lesions with liquid content in patients in dialysis. We describe the case of a female patient in dialysis who developed bullous lesions. The clinical and laboratory findings were initially compatible with the suspicion of pseudoporphyria, but the finding of some frankly elevated levels of porphyrins in serum, urine and feces confirmed the diagnosis of porphyria cutanea tarda. Porphyria cutanea tarda and pseudoporphyria present with common clinical manifestations. However, the levels of porphyrins in plasma, urine and feces in pseudoporphyria are normal or slightly elevated

[Registration of surface fluorescence of endogenous porphyrins during low-level laser therapy of gastric and duodenal ulcers]. / Izmerenie poverkhnostei fluorestsentsii éndogennykh porfirinov v protsesse lazeroterapii iazv zheludka i dvenadtsetiperstnoi kishki.

With the use of the developed opto-fiber spectroscope and gastroscope, the intensity of fluorescence from the ulcer surface into the gastrointestinal tract was measured in the range of 670-690 nm under the He-Ne laser (= 632.8 nm) illumination. Surface fluorescence data were collected with the use of a special diagnostic fiber with a total diameter of about 2 mm, which combines some illuminating and receiving fibers. To do the measurements, the diagnostic fiber was brought into a slight contact with the mucosa surface. The quantitative results were calculated with the use of the special fluorescent contrast coefficient (Kf), which takes into account the backscattered light as well. After the fluorescent diagnostic procedure, the low-level laser therapy was applied to all patients. It was found that: first of all, during the laser medical cure the registered fluorescence for the patients with a good dynamics of treatment had an evident tendency to a decrease, and the coefficient Kf for observed ulcers tended to approach the value obtained from normal mucosa (Kf), which indicates the normalization of the porphyrin content in the tissue. Second, the retrospective analysis of the efficacy of laser therapy versus initial values of Kf showed that, for the patients with the initial values Kf = 0.2, the efficiency of the laser treatment was the highest: the relation between the patients with good treatment results and bad ones was 4:1 (more than 80%). For the initial Kf = 0.2-0.3, this relation was 3:1 but for Kf = 0.4-0.5 it was 2:3. The differences in the efficiency of the low-level laser therapy, except the cases of the cancer in the ulcers, may be due to different content of porphyrin in the tissue: at high concentrations of the photosensitizer in the ulcer, the effect of the overdosing could be realized. In this case, another technology of laser illumination is needed. The results are discussed in terms of the free-radical conception of the stimulating effect of laser radiation.

Blue light phototherapy in the treatment of acne.

BACKGROUND: Blue light irradiation is known to be effective against acne. However, the profile of a good candidate is still unclear. METHODS: Thirty-one Taiwanese with symmetrical facial acne were irradiated with blue light on one side of the face selected randomly twice weekly for 4 consecutive weeks. The other half of the face was left untreated as control. Parameters, including scar type, pore size, and facial follicular porphyrin fluorescence intensity, were documented. The severity of acne was assessed before the treatment, after two, four, and eight sessions of treatment, and 1 month after the treatment was completed. RESULTS: Compared with the non-irradiation side, eight sessions of blue light irradiation were effective in acne treatment (P<0.001). Gender (P=0.471), scar type (P-values of pitted, atrophic, and hypertrophic type were 0.688, 0.572, and 0.802, respectively), pore size (P=0.755), and pretreatment fluorescence intensity (P=0.656) could not be used as predictive factors of therapeutic effectiveness. Compared with pretreatment, nodulocystic lesions tended to worsen despite treatment. In addition, the therapeutic effectiveness was not related to the fluorescence intensity change (P=0.812). CONCLUSIONS: Blue light irradiation is effective in acne treatment. Patients without nodulocystic lesions are better candidates for blue light irradiation.

Porphyrin metabolism in lymphocytes of miners exposed to diesel exhaust at oil shale mine.

The present study was carried out on the evaluation and application of new biomarkers for populations exposed to occupational diesel exhaust at oil shale mines. Since not only genotoxic effects may play an important role in the generation of tumors, the level of porphyrin metabolism was proposed as a biomarker of diesel exhaust exposure effects. The data on determination of 5-aminolevulinic acid (ALA) synthesis and heme formation in lymphocytes from groups of 50 miners exposed to diesel exhaust and 50 unexposed surface workers of oil shale mine are presented. All workers were examined and interviewed using structured questionnaires. The levels of benzene, carbon monoxide and nitric oxides in air as well as concentrations of 1-nitropyrene and elemental carbon in particulate matter were used for evaluation of exposure to diesel exhaust in mine. The levels of ALA and protoporphyrin (PP), activities of ALA synthetase (ALA-S) and ferrochelatase (FC), as well as levels of PP associated with DNA (PP/DNA) were investigated in lymphocytes spectrophotometrically. Significant differences in activity of ALA synthesis and heme formation between exposed miners and surface workers were found (207+/-23 vs. 166+/-14 pmol/10(6) lymp./30' for ALA-S and 46.1+/-3.8 vs. 54.8+/-4.1 pmol/10(6) lymp./60' for FC activities, respectively, P<0.001). ALA-S activity was higher and ALA accumulated in lymphocytes of exposed miners. Inhibition of FC activity caused PP cellular accumulation and an increase in the PP/DNA level (P<0.05). Tobacco smoking led to the increase of ALA biosynthesis in lymphocytes of both surface and underground smokers. The comparison of data obtained for non-smokers and smokers of both groups of workers has shown a significant difference (P<0.05). The work duration of underground or surface workers did not significantly influence the investigated biochemical parameters. The determination of ALA synthesis in lymphocytes could be a useful biomonitoring index of organism sensitivity to underground working. The alterations of PP levels, FC activity and PP/DNA association in peripheral lymphocytes of miners illustrate the harmful effects of exposure to diesel exhaust.

Response of river otters to experimental exposure of weathered crude oil: fecal porphyrin profiles.

Profiles of porphyrins were characterized in fecal samples from river otters (Lontra canadensis) experimentally exposed to weathered crude oil to determine effects on heme synthesis. Fifteen male river otters were randomly assigned to three groups of five individuals each representing a control group, a low-dosage group that received 5 mg/kg body mass of oil per day, and a high-dosage group that received 50 mg/kg body mass of oil per day. Mean levels of coproporphyrin III (CoproIII) and protoporphyrin IX (ProtoIX) in fecal samples collected from all experimental river otters were higher throughout the experimental period than levels of CoproIII and ProtoIX in fecal samples collected previously at two field sites. No statistically significant differences in levels of CoproIII and ProtoIX were observed between treatment groups, although a trend of reduction in variability in CoproIII was observed in the low- and high-dose groups. We found no relation between levels of CoproIII and ProtoIX, suggesting that the process of disruption that leads to oxidation of the precursors of porphyrins is probably nonlinear. Our results also indicate that the interaction between oiled induced reduction in hemoglobin levels and induction of CYP1A1 corresponded with significantly lower levels of ProtoIX in the fecal samples, possibly representing high demand for ProtoIX. Therefore, while this experiment does not support the use of porphyrin profiles as an individual biomarker, it does suggest that the latter may be valuable when a weight of evidence is used in an ecotoxicological risk assessment in which the interactions between several biomarkers are explored.

A mouse model of familial porphyria cutanea tarda.

Approximately one-third of patients with porphyria cutanea tarda (PCT), the most common porphyria in humans, inherit a single mutant allele of the uroporphyrinogen decarboxylase (URO-D) gene. PCT associated with URO-D mutations is designated familial PCT. The phenotype is characterized by a photosensitive dermatosis with hepatic accumulation and urinary excretion of uroporphyrin and hepta-carboxylic porphyrins. Most heterozygotes for URO-D mutations do not express a porphyric phenotype unless hepatic siderosis is present. Hemochromatosis gene (HFE) mutations are frequently found when the phenotype is expressed. We used homologous recombination to disrupt one allele of murine URO-D. URO-D(+/-) mice had half-wild type (wt) URO-D protein and enzymatic activity in all tissues but did not accumulate hepatic porphyrins, indicating that half-normal URO-D activity is not rate limiting. When URO-D(+/-) mice were injected with iron-dextran and given drinking water containing delta-aminolevulinic acid for 21 days, hepatic porphyrins accumulated, and hepatic URO-D activity was reduced to 20% of wt. We bred mice homozygous for an HFE gene disruption (HFE(-/-)) to URO-D(+/-) mice, generating mice with the URO-D(+/-)/HFE(-/-) genotype. These animals developed a porphyric phenotype by 14 weeks of age without ALA supplementation, and URO-D activity was reduced to 14% of wt. These data indicate that iron overload alone is sufficient to reduce URO-D activity to rate-limiting levels in URO-D(+/-) mice. The URO-D(+/-) mouse serves as an excellent model of familial PCT and affords the opportunity to define the mechanism by which iron influences URO-D activity.

Meso-tetraphenylporphyrin in liposomes as a suitable photosenzitizer for photodynamic therapy of tumors.

The suitability of a liposomal form of hydrophobic nonsulfonated meso-tetraphenyl porphyrin (TPP) for the photodynamic therapy of tumors was investigated. TPP was solubilized in small unilamellar lipid vesicles prepared by extrusion on a LIPOSOFAST apparatus. These samples were studied by laser-excited time resolved luminescence and triplet-triplet absorption spectroscopy. In this lipid environment TPP was still an efficient singlet oxygen producer, as indicated by the characteristic singlet oxygen phosphorescence at 1270 nm in D2O, when excited with a 28 ns laser pulse at 412 nm. Moreover, unlike with sulfonated TPP (TPPS4), liposomal TPP showed the reduced decay rates of TPP triplet-states with the increasing time of pre-illumination by a Xenon lamp. This was shown in an indirect way, based upon the appearance of a second component of the luminescence decay at 1270 nm in D2O; and by direct TPP triplet state monitoring, detecting triplet-triplet absorption at 440 nm in H2O. The deactivation of higher triplet states was delayed upon pre-illumination. This reflects an irreversible interaction of singlet oxygen with membrane lipids, thus demonstrating the potential of the liposomal form of TPP to efficiently disintegrate tumor cell membranes and to be a suitable preparation for the photodynamic therapy.

Photodynamic diagnosis and therapy in dermatology.

The topical application of delta-aminolevulinic acid (ALA) induces porphyrin formation in the skin, preferentially in tumor tissues. Irradiation of the porphyrin-enriched tumor tissue with Wood's light leads to emission of a brick-red fluorescence. This principle may be used as a diagnostic procedure which may be termed photodynamic diagnosis (PDD). In ALA-PDD, tumors and precancerous lesions of the skin reveal a homogeneous, intensive red fluorescence. Psoriatic lesions also show a strong but inhomogeneous porphyrin fluorescence. ALA-induced porphyrin fluorescence in preoperative planning is a valuable method to determine the peripheral borders of a given tumor. The histopathological extensions of the tumors correlate well with the borders detected by the tumor-specific fluorescence. The main indications of PDD are the delineation of clinically ill-defined skin tumors and the control of the efficacy of other tumor therapies. Photodynamic therapy (PDT) utilizes exogenously applied or endogenously formed photosensitizers and their activation by light to induce cell death via formation of singlet oxygen and other free radicals. PDT is highly efficient in the treatment of solar keratoses and superficial basal cell carcinomas. Initial squamous cell carcinomas also show good response to ALA-PDT. During the last decade, numerous studies on PDT for dermatologic diseases were published, the more important ones are reviewed here.

Biochemical diagnosis of a fatal case of Günther's disease in a newborn with hydrops foetalis.

The birth of a male baby was induced at 32 weeks. In utero, the child presented, inter alia, signs of hydrops, hepatosplenomegaly and anaemia. Two in utero transfusions for correction of the anaemia were performed at 28 and 29 weeks, respectively. The baby rapidly presented respiratory distress with mixed acidosis. Three hours after birth, pink urine was excreted. Signs of icterus necessitated phototherapy, after which photosensitivity occurred. Erythrocytes were fluorescent under long-wavelength UV light. The baby died 24 hours after birth, displaying severe acidosis, a diffuse haemorrhagic syndrome, and repeated brady-cardia which did not respond to isoprenaline. The analysis of porphyrins in urine, blood and faeces of the baby gave the following results: 1) uroporphyrin (I and III isomeric series) was increased in urine and faeces, with traces in erythrocytes and plasma; 2) heptacarboxyporphyrin I was found mainly in urine and much less in erythrocytes, plasma and faeces; 3) coproporphyrin I was increased in urine, erythrocytes, plasma and faeces, and 4) 5-aminolaevulinic acid and porphobilinogen in urine and plasma were within the reference ranges. Determination of the enzymes of haem biosynthesis in erythrocytes and lymphocytes showed that both parents possessed only 50% of the normal activity of cosynthase. A previously described point mutation in codon 73 was observed in one parent. Fatal cases of neonatal Günther's disease are extremely rare and such an observation, according to our knowledge, is probably one of the first described.

Carbon and nitrogen isotopic compositions of alkyl porphyrins from the Triassic Serpiano oil shale.

The carbon and nitrogen isotopic compositions of seven of the most abundant alkylporphyrins from the Serpiano oil shale (marine, Triassic) were determined. For the C31 and C32 butanoporphyrins, values of delta 13CPDB and delta 15NAIR averaged -24.0% and -3.1%. In contrast, the C31 and C32 methylpropanoporphyrins, DPEP, and a C30 13-nor etioporphyrin had delta 13C and delta 15N values averaging -27.5 and -3.3%, respectively. Carbon and nitrogen isotopic values for kerogen averaged -30.8 and -0.9, whereas those for total extract averaged -31.6, and -4.0%. The butanoporphyrins apparently derive from a biological source different from that giving rise to the other porphyrins, their 13C enrichment not being related to carbon isotopic fractionation accompanying diagenetic reactions. The delta 15N values for all the porphyrins indicate that the depletion of 15N observed in the kerogen is of primary origin. Consistent with the very high abundance of hopanoids and methyl hopanoids in the aliphatic hydrocarbon fraction, it is suggested that cyanobacterial fixation of N2 may have been the main cause of 15N depletion.