A novel 3D evaluation method for assessing bone to bone relationships in clubfoot.

OBJECTIVE: Clubfoot is a complex congenital three-dimensional foot deformity, which affects 150,000-200,000 newborn babies annually around the world. A good understanding of the alignment of the two osseous columns and the lower leg of the ankle and foot complex is essential for evaluating the severity of clubfoot. The purposes of this study were to (1) develop an automated three-dimensional (3D) surface model of severe clubfoot based on two-dimensional (2D) slices of computed tomography (CT) images, (2) evaluate the alignment of foot bones relative to the ankle in severe clubfoot, and (3) examine the structural changes in the shape of the clubfoot. PATIENTS AND METHODS: Two-dimensional CT image was taken from a four-year-old child with a severe clubfoot. Subsequently, an automated and detailed 3D surface model of the severe clubfoot was developed from the 2D images by using MATLAB software programming. Then, the x, y, and z coordinate angles were automatically calculated for each bone in the foot relative to the ankle (lower end of the tibia) to determine the orientations and relationships among the bones. RESULTS: The relative position or orientation of each bone of the foot to the ankle of the severe clubfoot was objectively measured which was used to determine the orientation of each bone in the foot. Among the x, y, and z axes of the interested tarsal bones, the z axis represents the smallest moment of inertia, and the results showed that the bones in the x axis shifted medially with higher relative angle. CONCLUSIONS: This 3D objective measurement method for assessing clubfoot can be used to determine and classify the severity of clubfoot, as well as evaluate and monitor the progress of the clubfoot intervention based on the relative position of the tarsal bones. The method can also be used to quantify the relationship between the tarsal bones of the foot and lower end of the tibia. In addition, angular measurements can be used to assess other pathological conditions of the foot such as pes cavus and pes planus.

Functional associations of genetic variants involved in the clinical manifestation of erythropoietic protoporphyria in the Argentinean population.

BACKGROUND: Combined inheritance of genetic variants in ferrochelatase gene (FECH) are implicated in clinical manifestation of Erythropoietic Protoporphyria (EPP). OBJECTIVE: Identify the genetic variants in FECH gene and their associations in the expression of EPP in Argentina. Determine the allelic frequency of polymorphic variants, associations in cis and its linkage disequilibrium. METHODS: The FECH gene was PCR-amplified and sequenced. Allelic variants of intragenic polymorphisms were identified by PCR followed by sequencing or restriction digestion analysis. Residual FECH activity was determined by prokaryotic expression in Escherichia coli JM109. Data were analyzed using Haploview and Statistix 9. RESULTS: Ten mutations were identified: three novel (p.S222N; p.R298X and p.R367X) and seven already known (g.12490_18067del; p.R115X; p.I186T; c.580_584delTACAG; c.598 + 1 G>T; p.Y209X and p.W310X). The p.R115X mutation was found in two families. The p.S222N mutation expressed 5% of normal activity. Only individuals who inherited a mutation combined in trans to a low expression allele c.1-251G, c.68-23T, and c.315-48C, showed clinical symptoms. The absence of c.315-48C variant was sufficient for not triggering EPP. However, these variants showed high levels of cosegregation and GTC haplotype is over-represented in EPP patients. CONCLUSION: In the dominant inheritance form of EPP, c.315-48C variant in trans to the mutated allele is sufficient to trigger the disease. The presence of GTC haplotype in all patients with dominant EPP could be due to the high level of cosegregation of c.315-48C with c.1-251G and c.68-23T variants in our population.

Induction of hepatic aminolevulinate acid synthetase activity by isoflurane in a genetic model for erythropoietic protoporphyria.

Erythropoietic Protoporphyria (EPP) is an inherited deficiency of ferrochelatase, the last enzyme of the heme pathway. Under general anaesthesia, some patients develop neurological dysfunction suggesting upregulation in heme biosynthesis similar to that described for acute porphyrias after xenobiotic administration. Our aim has been to evaluate whether Isoflurane induces alterations in the heme pathway in a mouse model for EPP. Administration of Isoflurane (a single dose of 2 ml/kg, i.p) to wild-type (+/+), heterozygous (+/Fechm1Pas) and homozygous (Fechm1Pas/Fechm1Pas) mice, was evaluated by measuring the activity of delta-aminolevulinic acid synthetase (ALA-S) and Porphobilinogen-deaminase (PBG-D) in different tissues, as well as Heme oxygenase (HO), cytochrome P-450, CYP2E1 and glutathione levels in liver. Porphyrin precursors were measured in 24 h-urine samples. Fechm1Pas/Fechm1Pas mice receiving anaesthesia show enhanced ALA-S and CYP2E1 activities in the liver and increased urinary excretion of porphyrin precursors. No alterations were found in either PBG-D or HO activities. Diminished glutathione levels suggest that anaesthesia may produce oxidative stress in these animals. In conclusion, Isoflurane induces ALA-S activity and increased excretion of porphyrin precursors in EPP mice. These findings appear to confirm our previous hypothesis and indicate that Isoflurane may be an unsafe anaesthetic not only for patients with acute porphyrias but also for individuals with non acute porphyrias.

The very first description of a patient with hepatoerythropoietic porphyria in Argentina. Biochemical and molecular studies.

Hepatoerythropoietic Porphyria (HEP) is the rare homozygous form of Porphyria Cutanea Tarda (PCT). It is characterized clinically by the early onset of severe skin manifestations which can be confused with Congenital Erythropoietic Porphyria (CEP) or with PCT when the symptoms are mild. We describe the case of a 14 year-old child with skin manifestations similar to those observed in PCT. The biochemical assays ruled out a CEP as well as they suggested the development of a HEP. Although his symptoms were not severe enough to be HEP, the enzymatic activity was dramatically reduced to a 5% of normal values and the molecular analysis revealed the presence of two already known different mutations on the patient's URO-D gene, c.703 C>T and IVS9-1. Each parent carry one of the mutations, but they were absent in the brother. This is the first Argentinean HEP case ever described which appeared in a compound heterozygous form and less residual URO-D activity but associated to a mild phenotype.

Acute porphyrias in the Argentinean population: a review.

The porphyrias are a group of inherited metabolic disorders of heme biosynthesis which result from a partial deficiency in one of its seven specific enzymes, after its first and rate limiting enzyme, delta-aminolevulinic acid synthetase. They can be classified on the basis of their clinical manifestations into cutaneous, acute and mixed disorders. Acute intermittent porphyria (AIP) is the most common type of hepatic acute porphyrias, inherited as an autosomal dominant trait, caused by a defect in the gene which codifies for the heme enzyme porphobilinogen deaminase. Its prevalence in the Argentinean population is about 1:125,000. A partial deficiency in another enzyme, protoporphyrinogen oxidase, produces variegate porphyria (VP), the second acute porphyria most frequent in the Argentinean population (1:600,000). Here, we review all the mutations we have found in 46 AIP and 9 VP unrelated Argentinean patients. To screen for mutations in symptomatic patients, we have proposed a geneticresearch strategy.

Scavengers protection of cells against ALA-based photodynamic therapy-induced damage.

The exogenously stimulated formation of intracellularly generated protoporphyrin IX, a precursor of haem, is becoming one of the fastest developing areas in the field of photodynamic therapy (PDT). We tested the action of several free radical scavengers, amino acids, antioxidants and sulphur-containing compounds as protectors from photodamage induced by 5-aminolaevulinic acid (ALA)-mediated PDT, employing the LM2 cell line, derived from a mammary murine adenocarcinoma. We exposed the cells to different concentrations of the compounds, 24 h before PDT, during PDT, and 19 h after treatment. We defined the protection grade (PG) as the ratio between cell survival after ALA-PDT treatment in the presence of the protector and cell survival of ALA-PDT treatment alone. We found that l -tryptophan (PG=9.2 at 2 m m ), reduced glutathione (GSH) (PG=5.8 at 0.8 m m ), N-acetyl- l -cysteine (PG=4.86 at 30 m m ), melatonin (PG=4.5 at 8 m m ) and l -methionine (PG=4.0 at 0.8 m m ) are the best protectors from PDT damage, followed by l -cysteine (PG=2.8 at 0.8 m m ), mannitol (PG=2.6 at 20 m m ) and glycine (PG=2.4 at 40 m m ) whereas oxidised glutathione and S-adenosyl- l -methionine do not exert any protection. We did not found any photoactive action of the protectors in absence of ALA. These results can be considered to modulate the photodamage induced by ALA-PDT.

ALA and ALA hexyl ester in free and liposomal formulations for the photosensitisation of tumour organ cultures.

In spite of the wide range of tumours successfully treated with 5-aminolevulinic acid mediated photodynamic therapy, the fact that 5-aminolevulinic acid has low lipid solubility, limits its clinical application. More lipophilic 5-aminolevulinic acid prodrugs and the use of liposomal carriers are two approaches aimed at improving 5-aminolevulinic acid transmembrane access. In this study we used both 5-aminolevulinic acid and its hexyl ester in their free and encapsulated formulations to compare their corresponding endogenous synthesis of porphyrins. Employing murine tumour cultures, we found that neither the use of hexyl ester nor the entrapment of either 5-aminolevulinic acid or hexyl ester into liposomes increase the rate of tumour porphyrin synthesis. By light and electronic microscopy it was demonstrated that exposure of tumour explants to either free or liposomal 5-aminolevulinic acid and subsequent illumination induces the same type of subcellular damage. Mitochondria, endoplasmic reticulum and plasma membrane are the structures mostly injured in the early steps of photodynamic treatment. In a later stage, cytoplasmic and nuclear disintegration are observed. By electronic microscopy the involvement of the endocytic pathway in the incorporation of liposomal 5-aminolevulinic acid into the cells was shown.

Photodynamic therapy of activated and resting lymphocytes and its antioxidant adaptive response.

In this work we have studied the effects of ALA-mediated photodynamic therapy (PDT) on resting and mitogen-activated murine splenic lymphocytes, evaluating its impact on cell viability. We have also characterised the stress response, measuring the levels of antioxidant enzymes. A 2h exposure to ALA produced 50% lethality upon irradiation of activated cells with 2.1J/cm2. The decrease in cell survival with increasing time exposure to ALA, correlated well with the higher porphyrin accumulation. In resting lymphocytes, in spite of the low amount of porphyrins formed during 2h incubation with ALA, 40% of the cells died after irradiation, this response was not further increased when higher amounts of porphyrins were synthesised. Superoxide dismutase was impaired by light treatment independently of ALA exposure in activated lymphocytes and, to a lesser extent, in resting lymphocytes. PDT induced an antioxidant adaptive response in activated cells 19 h after irradiation, reflected as a net increase in GSHPx activity and a slight reversion of the catalase (CAT) activity already impaired by light treatment. PDT treatment of activated cells also produced a diminution in the GSH/GSSG ratio. Only activated cells are capable of developing an antioxidant adaptive response to PDT treatment.

Effect of acetaminophen on heme metabolism in rat liver.

BACKGROUND AND AIMS: Acetaminophen (APAP) or paracetamol is a hepatotoxic drug through mechanisms involving oxidative stress. To know whether mammalian cells possess inducible pathways for antioxidant defense, we have to study the relationship between heme metabolism and oxidative stress. METHODS: fasted female Wistar rats received a single injection of APAP (3.3 mmol kg(-1) body weight) and then were killed at different times. Heme oxygenase-1 (HO), delta-aminolevulinic acid (ALA) synthase, ALA dehydratase, and porphobilinogenase activities, lipid peroxidation, GSH, catalase and glutathione peroxidase, were measured in liver homogenates. The antioxidant properties of bilirubin and S-adenosyl-L-methionine were also evaluated. RESULTS: APAP increased lipid peroxidation (115% +/- 6; S.E.M., n=12 over control values) 1 h after treatment. GSH reached a minimum at 3 h (38% +/- 5) increasing thereafter. At the same time antioxidant enzymes reached minimum values (catalase, 5. 6 +/- 0.4 pmol mg(-1) protein, glutathione peroxidase, 0.101 +/- 0.006 U mg(-1) protein). HO induction was observed 6 h after treatment reaching a maximum value of 2.56 +/- 0.12 U mg(-1) protein 15 after injection. ALA synthase (ALA-S) induction occurred after enhancement of HO, reaching a maximum at 18 h (three-fold the control). ALA dehydratase activity was first inhibited (31 +/- 3%) showing a profile similar to that of GSH, while porphobilinogenase activity was not modified along the whole period of the assay. Administration of bilirubin (5 micromol kg(-1) body weight) or S-adenosyl L-methionine (46 micromol kg(-1) body weight) 2 h before APAP treatment entirely prevented the increase in malondialdehyde (MDA) content, the decrease in GSH levels as well as HO and ALA-S induction. CONCLUSION: This study shows that oxidative stress produced by APAP leads to increase in ALA-S and HO activities, indicating that toxic doses of APAP affect both heme biosynthesis and degradation.

Identification and characterization of two novel mutations that produce acute intermittent porphyria: A 3-base deletion (841-843delGGA) and a missense mutation (T35M).

A partial deficiency of Porphobilinogen deaminase (PBGD) is responsible for acute intermittent porphyria (AIP). AIP is inherited in an autosomal dominant fashion, and the prevalence in the Argentinean population is about 1:125,000. Here, two new mutations and two previously reported were found in the PBGD gene in 22 Argentinean AIP patients corresponding to 8 different families. To screen for AIP mutations in symptomatic patients, genomic DNA isolated was amplified in 6 PCR reactions, then all coding exons and flanking intronic regions were sequenced. The novel mutations are 841-843delGGA in exon 14, which results in the loss of glycine-281 (G281del), and one 104C>T point mutation in the exon 4 (T35M). To further characterize both novel mutations, the pKK-PBGD construct for the mutant alleles were expressed in E. coli, the enzymatic activity of the recombinant proteins were 1% and 4% of the mean level expressed by the normal allele for 841-843delGGA and T35M, respectively. Hum Mutat 16:373, 2000.

Relevance of cytochrome P450 levels in the actions of enflurane and isoflurane in mice: studies on the haem pathway.

1. The effect of the fluorinated ether anaesthetics enflurane and isoflurane in mice on haem metabolism and regulation in different metabolic states, such as depression and induction of cytochrome P450 produced by allylisopropylacetamide (AIA) and imidazole, respectively, was investigated. 2. Mice previously treated with AIA (350 mg/kg, i.p.) or imidazole (400 mg/kg, i.p.) received a single dose (1 mL/kg, i.p.) of enflurane or isoflurane and were killed 20 min after anaesthetic administration. 3. Induction of delta-aminolevulinic acid synthetase (ALA-S) activity was found, as expected, in animals receiving AIA and also in animals treated with AIA plus anaesthesia, but no change in the activity of either porphobilinogenase (PBGase) or porphobilinogen deaminase (PBG-D) activities was detected in these two groups of animals. An additional increase in haem destruction was observed in the AIA plus isoflurane-treated group. When mice were injected with imidazol alone or in combination with the anaesthetics, ALA-S activity was increased 50-90% in all groups, but again no change in PBGase or PBG-D activity was observed. Haem oxygenase was diminished in mice receiving imidazole and anaesthesia. 4. In conclusion, neither enflurane nor isoflurane caused additional disturbances in haem metabolism to those produced by AIA or imidazole alone.

The influence of the vehicle on the synthesis of porphyrins after topical application of 5-aminolaevulinic acid. Implications in cutaneous photodynamic sensitization.

BACKGROUND: The optimal vehicle to ensure adequate penetration of 5-aminolaevulinic acid (ALA) for its use in photodynamic therapy (PDT) of skin lesions has not been determined. OBJECTIVES: We aimed to study the effects of ALA in various vehicle formulations [saline lotion with and without dimethylsulphoxide (DMSO), cream, liposomes and vaseline] after topical application in a murine subcutaneous adenocarcinoma model. METHODS: The effect of DMSO on porphyrin synthesis and ALA penetration through the skin was studied by measuring the uptake of 14C label from ALA, ALA and porphobilinogen accumulation, and some haem enzyme activities. The tissue distribution and kinetics of porphyrin synthesis after topical application of ALA entrapped in large multilamellar liposomes was also determined. RESULTS: ALA in saline lotion, alone or with 10% DMSO, proved to be the most efficient vehicle for tumour porphyrin accumulation (mean +/- SD 1.75 +/- 0.25 and 2.09 +/- 0.39 microg g-1, respectively), whereas cream and liposomes induced lower levels and identical porphyrin accumulation (0.60 microg g-1). Using ALA + DMSO saline lotion, a higher porphyrin accumulation was found in skin overlying the tumour tissue and in the first 2 mm of tumour, probably due to increased ALA penetration, or greater interconversion to porphyrins, or greater retention of ALA and/or porphyrins. CONCLUSIONS: These findings reinforce the importance of the vehicle in topical ALA-based PDT, and explain the mechanism of action of DMSO in enhancing protoporphyrin IX biosynthesis in superficial lesions.

Mutations in familial porphyria cutanea tarda: two novel and two previously described for hepatoerythropoietic porphyria.

Uroporphyrinogen decarboxylase (URO-D) deficiency is responsible for two forms of genetic cutaneous porphyria: familial porphyria cutanea tarda (f-PCT) and hepatoerythropoietic porphyria (HEP). The f-PCT transmitted as an autosomal dominant trait, is characterized by photosensitive cutaneous lesions frequently associated to hepatic dysfunction and is precipitated by various ecogenic factors. The HEP, transmitted as a recessive trait, is more severe than f-PCT and would be considered as the homozygous form of f-PCT. For the mutational analysis of f-PCT patients, the entire URO-D gene was amplified and each exon, intron-exon boundaries and the promoter region were cycle sequenced. Five mutations were found in 6 unrelated families studied, of these, two were new: a nonsense mutation in exon 6 (W159X) and a splice defect in intron 9 (IVS9(-1)G-->C). The other two missense mutations, P62L and A80G, had been previously reported in the homozygous state in HEP families. The g10insA, reported in our laboratory, was again identified in other two unrelated families. In addition 3 novel URO-D polymorphisms in non-coding regions were found. The reverse transcription-PCR and sequencing of the splice mutation carrier's RNA did not reveal the presence of an abnormal mRNA, suggesting that no stable transcript from the mutated allele is synthesized. These results increase to 39 the number of mutations identified in the URO-D gene; 4 of them causing both HEP and f-PCT.

Porfiria variegata: signos cutáneos, agudos y bioquímicos. Primer estudio genético en pacientes Argentinos / Variegate porphyria: cutaneus sign, biochemistry and sharp. Genetic first study in Argentinean patients

Las porfirias son enfermedades metabólicas que surgen como consecuencia de una deficiencia enzimática parcial de alguna de las enzimas del hemo. En la porfiria Variegata (PV) este defecto se encuentra a nivel de la Protoporfirinógeno oxidasa (PPOX) quwe transforma el Protoporfirinógeno IX en Protoporfirina IX. Se caracteriza por presentar el síndromeagudo y cutáneo. Es una patología genéticamente heterogénea, al presente se han detectado 77 mutaciones diferentes en el gen de la PPOX, responsables de esta porfiria. Nuestro objetivo es el estudio bioquímico y molecular de pacientes con sintomatología de PV para llegar a un dignóstico certero de la enfermedad y hacerlo extensivo a sus familiares con el fin de identificar a los portadores asintomáticos y asesorarlos acerca del contacto con los factores desencadenantes de esta porfiria. Hasta el momento el estudio genético nos permitió detectar 2 mutaciones, una mutación puntual recientemente descripta que produce cambio de aminoácido, R168H en el exón 6 y una inserción nueva, 1320InT, que produce corrimiento del marco de lectura. Estos resultados han permitido confirmar el diagnóstico de PV en estos pacientes

Acute intermittent porphyria: biochemical and clinical analysis in the Argentinean population.

Acute intermittent porphyria (AIP) is the most common type of hepatic acute porphyria. In this work, we have analyzed the biochemical data of all Argentinean AIP families studied in the Porphyrins and Porphyrias Research Centre (CIPYP). We have shown that: (i) the prevalence for this population is about 1:125,000; (ii) the disease is more frequent in women than in men (7:3); (iii) about 60% are latent carriers; (iv) 15% of patients with symptomatic AIP died during an acute attack; (v) the most important precipitating factors of acute attacks in our population were the ingestion of therapeutic drugs (25%), anesthetics in surgical interventions (25%) and infections (20%); (vi) the initial symptom in Argentinean AIP individuals is severe abdominal pain (100%), and it is often accompanied by constipation (37%), anorexia (37%) and tachycardia (30%); and (vii) the percentage of recurrence of the acute attacks is high (81%).

Acute intermittent porphyria: characterization of two novel mutations in the porphobilinogen deaminase gene, one amino acid deletion (453-455delAGC) and one splicing aceptor site mutation (IVS8-1G>T).

A partial deficiency of Porphobilinogen deaminase (PBG-D) is responsible for acute intermittent porphyria (AIP). AIP is inherited in an autosomal dominant fashion, and the prevalence in the Argentinean population is about 1:125,000. Here, two new mutations and three previously reported were found in the PBG-D gene in 12 Argentinean AIP patients corresponding to 5 different families. To screen for AIP mutations in symptomatic patients, genomic DNA isolated was amplified in 2 Multiplex PCR reactions, then all coding exons and flanking intronic regions were sequenced. The new mutations are 453-455delAGC in exon 9 which results in the loss of an alanine residue at position 152, and one new point mutation in the splicing aceptor site in the last position of intron 8 (IVS8-1G>T) which leds to a 15 bp deletion because a cryptic site (first AG upstream) is used. Both mutations produce amino acid deletion without frameshift effect. To further characterize the 453-455delAGC mutation, the pKK-PBGD construct for the mutant allele was expressed in E. coli, the enzymatic activity of the recombinant protein was 1.3% of the mean level expressed by the normal allele. Finally, three missense mutations, previously reported, were identified in three unrelated families.

Tissue distribution and kinetics of endogenous porphyrins synthesized after topical application of ALA in different vehicles.

The use of 5-aminolaevulinic acid (ALA) is gaining increasing attention for photosensitization in photodynamic therapy of superficially localized tumours. The aim of this work was to determine the kinetics of porphyrin generation in tissues after topical application of ALA delivered in different vehicles on the skin overlying the tumour and normal skin of mice. Maximal accumulation was found in tumour 3 h after ALA application in both cream and lotion preparations. Normal and overlying tumour skin tissues showed different kinetic patterns, reflecting histological changes when the latter is invaded by tumour cells. Liver, kidney, spleen and blood porphyrins also raised from basal levels, showing that ALA and/or ALA-induced porphyrins reach all tissues after topical application. During the first 24 h of ALA topical application, precursors and porphyrins are excreted by both urine and faeces. ALA lotion applied on the skin overlying the tumour induced higher accumulation of tumoural porphyrins than cream, and lotion applied on normal skin appeared to be the most efficient upon inducing total body porphyrins. This work has demonstrated the great influence of the formulation of ALA vehicle on penetration through the skin. Knowledge of the kinetics of porphyrin generation after different conditions of ALA application is needed for the optimization of diagnosis and phototherapy in human tumours.