Impaired cognitive self-awareness mediates the association between alexithymia and excitation/inhibition balance in the pgACC.

BACKGROUND: Previous research showed that automatic emotion regulation is associated with activation of subcortical areas and subsequent feedforward processes to cortical areas. In contrast, cognitive awareness of emotions is mediated by negative feedback from cortical to subcortical areas. Pregenual anterior cingulate cortex (pgACC) is essential in the modulation of both affect and alexithymia. We considered the interplay between these two mechanisms in the pgACC and their relationship with alexithymia. METHOD: In 68 healthy participants (30 women, age = 26.15 ± 4.22) we tested associations of emotion processing and alexithymia with excitation/inhibition (E/I) balance represented as glutamate (Glu)/GABA in the pgACC measured via magnetic resonance spectroscopy in 7 T. RESULTS: Alexithymia was positively correlated with the Glu/GABA ratio (N = 41, p = 0.0393). Further, cognitive self-awareness showed an association with Glu/GABA (N = 52, p = 0.003), which was driven by a correlation with GABA. In contrast, emotion regulation was only correlated with glutamate levels in the pgACC (N = 49, p = 0.008). CONCLUSION: Our results corroborate the importance of the pgACC as a mediating region of alexithymia, reflected in an altered E/I balance. Furthermore, we could specify that this altered balance is linked to a GABA-related modulation of cognitive self-awareness of emotions.

A description of an HPLC assay of coproporphyrinogen III oxidase activity in mononuclear cells.

Coproporphyrinogen III oxidase is deficient in hereditary coproporphyria. An activity assay for this enzyme in mononuclear cells, besides the preparation of the substrate, are presented. The separation conditions for the product of the test protoporphyrin IX by gradient, reversed-phase high-performance liquid chromatography are given. The normal value from mononuclear cells of healthy volunteers was 138 +/- 21 pkat/g total soluble protein (mean +/- SD). The enzyme activity of a family with hereditary coproporphyria was measured. The gene carriers exhibit a specific coproporphyrinogen III oxidase activity of 61-90 pkat/g total soluble protein.

Molecular, immunological, enzymatic and biochemical studies of coproporphyrinogen oxidase deficiency in a family with hereditary coproporphyria.

A 27-year-old woman who had recurrent pain in renal bed since 1998 with increasing character, was stationary admitted. The patient showed dark urine, complained of hair loss and took since 1994 a hormonal oral contraceptive. No photosensitivity was observed. Determinations of urinary porphyrin metabolites in 1998 revealed a porphyria cutanea tarda like excretion pattern with elevations of uro- (1767 nmol/24 hr, normal <29 nmol/24 hr) and heptacarboxyporphyrin (568 nmol/24 hr; normal <4 nmol/24 hr). Follow-up studies in feces showed the characteristics of a hereditary coproporphyria with dominance of coproporphyrin isomer III (total= 1470 nmol/g, isomer III= 93%), (normal: <37 nmol/g, isomer III = 25-35%). The excretion of porphyrin precursors (delta-aminolevulinic acid and porphobilinogen) was increased by taking an ethinylestradiol-cyproteronacetate-preparation, but acute and/or chronic manifestations were not observed. Coproporphyrinogen oxidase activity was decreased to 35% in the patient (normal=138+/-21 pkat/g protein; x+/-s), whereas the activity of red cell uroporphyrinogen decarboxylase was normal. Her mother and both sisters could be verified as heterozygous gene carriers of hereditary coproporphyria by their urinary and fecal excretion parameters and because of reduced coproporphyrinogen oxidase activity up to 50%. The father was normal with respect to his genotype. Molecular analysis revealed a hitherto unknown mutation with the transversion of a cytosine to thymine at nucleotide position 854 in exon 4 of the coproporphyrinogen oxidase gene. The gene defect was confirmed by DGGE in the mother and her three daughters. The investigation of the immunological nature of the defective coproporphyrinogen oxidase gene from the whole family revealed decreased concentrations of coproporphyrinogen oxidase protein in the patient, her mother and her two sisters.

Hereditary coproporphyria in Germany: clinical-biochemical studies in 53 patients.

OBJECTIVES: To describe the biochemical and clinical features in hereditary coproporphyria (HCP). DESIGN AND METHOD: Within the last 20 years, we investigated 53 patients (male:female = 1:2.5; age = 8-86 years) suffering from HCP. We describe the characteristic levels of urine, and fecal porphyrins and their precursors in hereditary coproporphyria and present the clinical features. Especially, we measured the coproporphyrin isomers I and III. RESULTS AND CONCLUSION: The group of hereditary coproporphyria patients exhibited a significantly higher (p<0.0001) excretion of urinary porphyrin precursors, delta-aminolevulinic acid (median = 84 micromol/24 h) and porphobilinogen (median = 39 micromol/24 h), as compared to controls (delta-aminolevulinic acid: 22 micromol/24 h, porphobilinogen: 3 micromol/24 h; median, n = 20). The median of coproporphyrin in urine (1315 nmol/24 h) and feces (1855 nmol/g) were enhanced 12- and 168-fold, as compared to healthy subjects (urinary coproporphyrin: 106 nmol/24 h, fecal coproporphyrin: 11 nmol/g; median, n = 20). During therapy on one female patient, with IV application of heme arginate, a considerable decline of porphyrin precursors and porphyrin excretion was observed. The examination of urinary and fecal coproporphyrin isomers I and III revealed an excessive elevation of the coproporphyrin isomer III of 87% in urine and 94% in feces, respectively (normal: urinary isomer III = 69-83% and fecal isomer III = 25-40%). In feces the increase of isomer III caused an inversion of the physiologic coproporphyrin isomer III:I ratio that could be recognized in all various stages in hereditary coproporphyria and in children. Acute attacks of hereditary coproporphyria are accompanied by an acute polysymptomatic clinical syndrome, and this is associated with high levels of urinary porphyrin precursors. On review of our patients, the highest percentage had abdominal pain (89%), followed by neurologic (33%), psychiatric (28%), cardiovascular (25%), and skin symptoms (14%).

Alcohol and porphyrin metabolism.

Alcohol is a porphyrinogenic agent which may cause disturbances in porphyrin metabolism in healthy persons as well as biochemical and clinical manifestations of acute and chronic hepatic porphyrias. After excessive consumption of alcohol, a temporary, clinically asymptomatic secondary hepatic coproporphyrinuria is observable, which can become persistent in cases of alcohol-induced liver damage. Nowadays, the alcohol-liver-porphyrinuria syndrome is the first to be mentioned in secondary hepatic disturbances of porphyrin metabolism. Acute hepatic porphyrias (acute intermittent porphyria, variegate porphyria and hereditary coproporphyria) are considered to be molecular regulatory diseases, in contrast to non-acute, chronic hepatic porphyria, clinically appearing as porphyria cutanea tarda (PCT). Porphyrins do not accumulate in the liver in acute porphyrias, whereas in chronic hepatic porphyrias they do. Thus, chronic hepatic porphyria is a porphyrin-accumulation disease, whereas acute hepatic porphyrias are haem-pathway-dysregulation diseases, characterized in general by induction of delta-aminolevulinic acid synthase in the liver and excessive stimulation of the pathway without storage of porphyrins in the liver. The clinical expression of acute hepatic porphyrias can be triggered by alcohol, because alcohol augments the inducibility of delta-aminolevulinic acid synthase. In chronic hepatic porphyrias, however, which are already associated with liver damage, alcohol potentiates the disturbance of the decarboxylation of uro- and heptacarboxyporphyrinogen, which is followed by a hepatic accumulation of uro- and heptacarboxyporphyrin and their sometimes extreme urinary excretion. Especially in persons with a genetic deficiency of uroporphyrinogen decarboxylase, but also in patients with the so-called sporadic variety of PCT, alcohol is able to transform an asymptomatic coproporphyrinuria into PCT. Alcohol has many biochemical and clinical effects on porphyrin and haem synthesis both in humans and laboratory animals. Ethanol suppresses the activity of porphobilinogen synthase (synonym: delta-aminolevulinic acid dehydratase), uroporphyrinogen decarboxylase, coproporphyrinogen oxidase and ferrochelatase, whereas it induces the first and rate-limiting enzyme in the pathway, delta-aminolevulinic acid synthase and also porphobilinogen deaminase. Therefore, teetotalism is a therapeutically and prophylactically important measure in all types of hepatic porphyrias.

[Hepatic porphyrias and alcohol]. / Hepatische Porphyrien und Alkohol.

Alcohol has an porphyrinogenic action and can cause a disturbance of porphyrin metabolism in healthy people as well as lead to a biochemical and clinical manifestation of acute and chronic hepatic porphyrias, especially acute intermittent porphyria and porphyria cutanea tarda. After excessive consumption of alcohol a temporary, clinically asymptomatic secondary hepatic coproporphyrinuria in man can be observed, which can become persistent in cases of alcohol-induced liver damage. Nowadays alcohol-liver-porphyrinuria syndrome is the first to be mentioned in secondary hepatic disturbances of porphyrin metabolism. In people with a genetic lack of uroporphyrinogen-decarboxylase alcohol is able to transform an asymptomatic coproporphyrinuria into a chronic hepatic porphyria or porphyria cutanea tarda. From experimental and clinical studies the conclusion can be drawn that alcohol inhibits the enzymes delta-aminolevulinic-acid-dehydratase (synonym: porphobilinogen-synthase), uroporphyrinogen-decarboxylase and coproporphyrinogen-oxidase and induces delta-aminolevulinic-acid-synthase in the liver. Abstinence of alcohol is a therapeutically and prophylactically important measurement in all types of hepatic porphyrias. For clinical experience follows that in cases with chronic consumption of alcohol, fatty liver, alcohol induced hepatitis and liver cirrhosis porphyrin studies in urine should be made to notice a hepatic porphyria in the latent phase very early. When dealing with abdominal and cutaneous symptoms in clinical context with consumption of alcohol one has to exclude hepatic porphyria differential diagnostically.

Studies on coproporphyrin isomers in urine and feces in the porphyrias.

The urinary and fecal distribution and the relative proportions of the four coproporphyrin (copro) isomers I-IV were analysed in 20 healthy subjects and in patients suffering from one of the seven common types of hepatic or erythropoietic hereditary porphyrias. The ratios of copro isomers I-IV were analyzed by ion-pair high-performance liquid chromatography (HPLC). Observations showed significantly increased proportions of fecal copro isomer I and decreased proportions of copro isomers III, II and IV in erythropoietic porphyrias. In acute hepatic porphyrias the excretion of fecal copro isomer III is dominant (isomer III = 58.4+/-24.0%; x+/-S.D.) and significantly higher (P < 0.001) than in erythropoietic porphyrias (isomer III = 15.3+/-7.7%; x+/-S.D.) and chronic hepatic porphyrias (isomer III = 25.8+/-7.6%; x+/-S.D.). The increased proportions of fecal copro isomer III proved to be important for the diagnosis of hereditary coproporphyria and porphyria variegata independent of the clinical phase existing. These last two acute hepatic porphyrias also showed markedly elevated percentages of the fecal atypical isomers II and IV. In urine significantly decreased proportions of copro isomer I in acute hepatic porphyrias (isomer I = 12.3+/-6.0%; x+/-S.D.) could be observed as compared with non-acute porphyrias (isomer I = 53.7+/-15.2%; x+/-S.D.). Conversely, the proportion of urinary copro isomer III was significantly higher in acute hepatic porphyrias (isomer III= 81.4+/-6.4%; x+/-S.D.). As expected, the greatest amounts of urinary copro isomer I were found in congenital erythropoietic porphyria (isomer I =92.0+/-3.3; x+/-S.D.) and protoporphyria with hepatobiliary complications (isomer I = 81.3+/-10.7; x+/-S.D.). The atypical urinary copro isomers I1 and IV were detected in all types of porphyrias ranging from 0.1 to 11.5%. The combined amounts of copro isomers II and IV show a significantly decreased percentage in congenital erythropoietic porphyria as compared with all other types of hereditary porphyrias. In conclusion, we demonstrate that the characteristic pattern of the copro isomer constellations I-IV in the various types of porphyrias are of differential diagnostic importance. The inversion of the I to III ratio in feces in hereditary coproporphyria and porphyria variegata allows the recognition of gene carriers.

In vitro apoptosis and expression of apoptosis-related molecules in lymphocytes from patients with systemic lupus erythematosus and other autoimmune diseases.

OBJECTIVE: To analyze factors related to apoptosis in systemic lupus erythematosus (SLE) peripheral blood mononuclear cells (PBMC) and to compare the findings in SLE PBMC with those in normal donor PBMC or PBMC from patients with other autoimmune diseases. METHODS: PBMC from normal healthy donors or patients with SLE, mixed connective tissue disease (MCTD), rheumatoid arthritis (RA), or various vasculitides were isolated. The percentage of apoptosis after activation through different signaling pathways was quantified using propidium iodide staining. Protein expression of Fas/APO-1 or bcl-2, and messenger RNA (mRNA) expression of bcl-2, bcl-xL, bax, bak, Fas/APO-1, Fas ligand (Fas-L), c-myc, mad, or max were determined. RESULTS: We confirmed previous findings of increased numbers of apoptotic cells in SLE PBMC compared with normal donor cells after in vitro incubation. After activation of PBMC with CD28 monoclonal antibody plus phorbol myristate acetate (CD28 MAb/ PMA), staphylococcal enterotoxin B (SEB), or phytohemagglutinin (PHA), the percentage of apoptotic cells was unchanged (SEB) or diminished (CD28 MAb/PMA, PHA) in SLE cells, and the difference between normal donor and SLE cells was less pronounced. On the mRNA level, expression of apoptosis-related gene products did not differ between SLE cells and normal donor cells. Expression of Fas/APO-1 protein was increased in freshly isolated SLE T lymphocytes compared with normal donor T lymphocytes, whereas bcl-2 protein was up-regulated after a 3-day culture period. Cellular activation further increased bcl-2 protein levels, eliminating differences between normal donors and SLE patients. In RA cells, the percentage of apoptosis was similar to that in normal donor PBMC, whereas results using cells from patients with other autoimmune diseases (MCTD, Wegener's granulomatosis, Takayasu arteritis, polyarteritis nodosa) were comparable with those found using SLE PBMC. Addition of growth factors such as interleukin-2 (IL-2), IL-4, or IL-15 to culture medium decreased the percentage of in vitro apoptosis in both normal donor and SLE cells. CONCLUSION: Based on these data, we conclude that accelerated in vitro apoptosis and increased Fas/ APO-1 and bcl-2 protein expression in SLE are nonspecific for the disease, and might be explained at least in part by the increased in vivo activation levels of PBMC from patients with SLE, MCTD, or autoimmune vasculitides combined with in vitro incubation under "noninflammatory" conditions and growth factor withdrawal.

Combination of the chemotherapeutic agent 5-fluorouracil with an inhibitor of its catabolism results in increased micronucleus induction.

The rate limiting step in 5-fluorouracil catabolism is catalyzed by the enzyme dihydropyrimidine dehydrogenase. Since degradation of 5-fluorouracil decreases its efficacy in chemotherapy, the inhibition of its catabolism is a promising tool. We investigated the formation of micronuclei in vitro in mouse L5178Y cells. 5-fluorouracil induced an increase in micronucleus frequency, which could significantly be enhanced by the concurrent application of 2,6-dihydroxypyridine, an inhibitor of dihydropyrimidine dehydrogenase. The 5-fluorouracil concentration necessary to reach maximal genotoxic effects could be reduced to half in the presence of inhibitor 2,6-Dihydroxypyridine alone and the naturally occurring enzyme substrate uracil did not induce micronucleus formation. Combined application of the chemotherapeutic agent 5-fluorouracil and an inhibitor of its could reduce side-effects by lowering the effective dose of the active drug. With this study we provide further support for the usefulness of this concept.