Missense mutations in codon 225 of ornithine transcarbamylase (OTC) result in decreased amounts of OTC protein: A hypothesis on the molecular mechanism of the OTC deficiency

Mutations P225L and P225R were identified in codon 225 of the gene for ornithine transcarbamylase (OTC) in two patients with the neonatal form of OTC deficiency. The mutations occur at a CpG dinucleotide and eliminate a unique MspI restriction site in exon 7 of the OTC gene. They do not alter existing splice sites or create new sites, as judged from the nucleotide sequence. Both mutations are associated with undetectable levels of OTC antigen in liver homogenates, and with either complete lack of OTC activity (P225R mutation) or very small residual activity (0.15% of normal in the P225L mutation). The residual activity observed with P225L exhibits normal pH dependence, little or no increases in the Km values for ornithine and carbamoyl phosphate and normal stability at either 37°C or, in the presence of 0.66 mol/L urea, at 0°C. The latter conditions were used to examine whether the P225L mutation favours dissociation of the active OTC trimer. Given the normal stability and lack of tendency to dissociation of the mutant enzyme, it appears likely that the dramatic reduction in the level of OTC protein is due to inefficient conversion of the mutant OTC precursor polypeptide (pOTC) into the correctly localized, appropriately folded, mature enzyme trimer, suggesting degradation of pOTC in transit to the mitochondria.     

Coccygectomy has a favorable effect on the intensity, manifestation, and characteristics of pain caused by coccygodynia: a retrospective evaluation of 34 patients followed for 3–18 years

Background  Coccygodynia can cause severe pain and disability in patients. There are contradictions in the literature regarding the final results of coccygectomy for coccygodynia. We evaluated the long-term effects of coccygectomy on the intensity, characteristics, and manifestation of pain caused by coccygodynia to determine the adequacy of operation among treatment modalities. Materials and methods  Thirty-four patients with coccygodynia were treated by coccygectomy. In 22 cases, trauma, and in one case childbirth was the cause. 11 cases were regarded as idiopathic. The intensity, characteristics of pain, and the most painful activities were evaluated at an average of 7.6 (3–18) years of follow-up time. Results  Before the operation, all 34 patients had pain while sitting, moreover, 26 of them had pain during standing, walking, at night or a combination of these. 21 patients had intolerable or very intensive, mainly acute, sharp or burning pain. 11 patients had dyschesia, 2 had dysuria and 6 had dyspareunia. At follow-up, 7 patients were completely free of pain, 15 others had moderate, 11 medium, and only one patient had severe, but none had intolerable pain. Only seven patients had acute, sharp or burning pain postoperatively. The decrease of average pain score from 8.0 to 3.2 was significant (P < 10⁻¹²). The number of the patients with dyschesia and dyspareunia decreased from 11 to 7 and from 6 to 3, respectively. Two patients had dysuria, but their complaints did not change after the operation. One of the two patients who needed reoperation had an excellent final result, while the other remained unchanged. 12 and 16 patients (together 82%) regarded the final result of the operation excellent and good, respectively. The condition of five others did not change, while one became worse. The patients with younger age, smaller body mass index, and less co-morbidities had better final result. There were no serious complications. Conclusion  Coccygectomy for coccygodynia is a safe method to decrease the intensity of pain and other complaints of the patients. The operation can be the choice of treatment if conservative measures fail.     

Catalase enzyme mutations and their association with diseases.

Enzyme catalase seems to be the main regulator of hydrogen peroxide metabolism. Hydrogen peroxide at high concentrations is a toxic agent, while at low concentrations it appears to modulate some physiological processes such as signaling in cell proliferation, apoptosis, carbohydrate metabolism, and platelet activation. Benign catalase gene mutations of 5' noncoding region (15) and intron 1 (4) have no effect on catalase activity and are not associated with disease.Catalase gene mutations have been detected in association with diabetes mellitus, hypertension, and vitiligo. Decreases in catalase activity in patients with tumors is more likely to be due to decreased enzyme synthesis rather than to catalase mutations.Acatalasemia, the inherited deficiency of catalase has been detected in 11 countries. Its clinical features might be oral gangrene, altered lipid, carbohydrate, homocysteine metabolism and the increased risk of diabetes mellitus. The Japanese, Swiss, and Hungarian types of acatalasemia display differences in biochemical and genetic aspects. However, there are only limited reports on the syndrome causing these mutations.These data show that acatalasemia may be a syndrome with clinical, biochemical, genetic characteristics rather than just a simple enzyme deficiency.     

Magnesium-orotate supplementation for idiopathic infertile male patients: a randomized, placebo-controlled clinical pilot study.

A randomized, placebo-controlled clinical pilot study was performed in order to examine the effect of magnesium-orotate in male idiopathic infertility. Ten males were treated daily for 90 consecutive days with 3000 mg magnesium-orotate (Magnerot) tablets (Group M). As a control, ten other males were treated in the same way with placebo (Group P). Conventional microscopic sperm characteristics (sperm concentration, motility ratio, total number of motile sperm cells, normal morphology ratio), plus total and ionized magnesium levels in seminal plasma and blood serum were evaluated both prior to treatment and on day 90, at the conclusion of the study. No significant changes in sperm characteristics, blood ionized or total Mg, or ejaculate total Mg levels were detected. However, ejaculate ionized Mg levels increased in Group M from 0.18 +/- 0.05 to 0.30 +/- 0.05 (mmol/l; mean +/- SD, p < 0.05). Within the observation period of 3 months, one pregnancy occurred in the partner of a male from Group M. In conclusion, magnesium-orotate treatment at a dose of 3000 mg/day leads neither to a significant improvement of sperm variables nor does it increase the pregnancy rates of female partners of treated males as compared to those of controls. Thus, magnesium-orotate treatment was not shown to be effective therapy for idiopathic male infertility.     

Time course of superoxide generation by leukocytes—The MCLA chemiluminescence system

This study was performed to examine the pattern of Superoxide (O ₂ ^– ·) generation from leukocytes using the O ₂ ^– · specific chemiluminescence (CL) method.Cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA) was used as a CL probe. The appropriate conditions of the MCLA method was first determined for the evaluation of the time course of O ₂ ^– · generation by leukocytes. The time course of O ₂ ^– · generation obtained by the MCLA-CL system was compared with that by the luminol-dependent CL, electron spin resonance (ESR)/spin trapping, and cytochromec systems. Following stimulation by three different stimulants (PMA, OZ, FMLP), leukocytes continuously generated O ₂ ^– · for up to 5 h in the MCLA-CL system, irrespective of the kind of stimulation. The curves obtained by generation ceased more rapidly in the luminol-CL, ESR/spin trapping, and cytochromec systems. A 50% activity of the initial value was observed at 70 min in the MCLA-CL system, but 30, 10 and 35 min in the other systems, respectively. The CL or O ₂ ^– · generation value decreased to less than 1% (possible termination) at 300, 90, 120 and 180 min, respectively. With the exception of ESR studies with OZ, the cell viability was not significantly affected in any of the trials. These results indicate that leukocytes can generate O ₂ ^– · much longer than previously estimated and that the MCLA-CL-system is the most suitable system for the measurement of the O ₂ ^– · generation by leukocytes.     

Cast syndrome

The term cast syndrome is used to denote duodenal obstruction occurring after application of a corrective plaster cast to patients with scoliosis. We report a classical case in a 14-year-old female who required surgical intervention after conservative treatment failed. Six months later the patient had no further gastrointestinal symptoms. Clinical, radiological, and pathological details as well as the surgical treatment are described and discussed. Offprint requests to: M. E. Martín Hortigüela