Heme delivery to heme oxygenase-2 involves glyceraldehyde-3-phosphate dehydrogenase

Heme regulatory motifs (HRMs) are found in a variety of proteins with diverse biological functions. In heme oxygenase-2 (HO2), heme binds to the HRMs and is readily transferred to the catalytic site in the core of the protein. To further define this heme transfer mechanism, we evaluated the ability of GAPDH, a known heme chaperone, to transfer heme to the HRMs and/or the catalytic core of HO2. Our results indicate GAPDH and HO2 form a complex in vitro. We have followed heme insertion at both sites by fluorescence quenching in HEK293 cells with HO2 reporter constructs. Upon mutation of residues essential for heme binding at each site in our reporter construct, we found that HO2 binds heme at the core and the HRMs in live cells and that heme delivery to HO2 is dependent on the presence of GAPDH that is competent for heme binding. In sum, GAPDH is involved in heme delivery to HO2 but, surprisingly, not to a specific site on HO2. Our results thus emphasize the importance of heme binding to both the core and the HRMs and the interplay of HO2 with the heme pool via GAPDH to maintain cellular heme homeostasis.

[Psychological factors of genital automutilation and medico-ethical interest in emergency vulvoplasty]

The genital self-mutilation is not rare in women. Risk factors found in these cases are: mood disorders, food behavior anomalies and antecedents of sexual aggression. However, surgical repair is not done in emergency: we find no similar report to our clinical case describing an added up bilateral reduction nymphoplasty carried out in emergency after hemorrhagic genital self-mutilation. We discuss psychological risk factors, psychiatric diagnosis and optimal treatment, studied from medico-ethical point of view, for this surgical emergency.

[Vaginal evisceration. Report of a new case]

Vaginal evisceration is rare and most commonly found in postmenopausal women. We report the case of a postmenopausal woman due to ruptured enterocele. Surgical treatment was done through a midline laparotomy and consisted of bowel resection with primary anastomosis and vaginal vault suture repair. Risk factors for this rare clinical entity are discussed along with the different therapeutic options.

Delayed delivery of second twin: a multicentre study of 35 cases

OBJECTIVE

The aim of this study was to conduct a statistical analysis to determine the outcome of conservative treatment after delivery of a first fetus in multiple pregnancy and thus define new prognostic factors.

STUDY DESIGN

Multicentre retrospective study involving 12 centers over a 10-year period.

RESULTS

Twenty-eight twin pregnancies and seven triplet pregnancies which were managed conservatively. In twin pregnancies, 79% of the delayed-delivery fetuses survived; only 7% of the first delivered fetuses survived. The mean interval between deliveries was 47 days. No statistical difference was found concerning cerclage, antibiotic therapy, tocolysis and hospitalization. Earlier delivery of the first twin and premature rupture of membranes for the second twin were significantly related to a longer interval between deliveries.

CONCLUSION

Delayed delivery in multifetal pregnancies can be successful if there are no contraindications and these pregnancies are managed in a tertiary perinatal center. Publications limited to successful cases have undoubtedly introduced some bias in assessment.

Purification of a toxic factor from Arabian Gulf catfish epidermal secretions

The Arabian Gulf catfish, Arius bilineatus (Valenciennes) secretes a proteinaceous epidermal secretion when threatened or injured. A toxic factor has been isolated and purified from the crude extract (crude skin toxin) of these secretions by a combination of gel filtration on Sephacryl S-300 and preparative discontinuous polyacrylamide gel electrophoresis. The purified skin toxin has a molecular weight of 39,000 Da and an isoelectric point (pI) of 5.45. Injection of the purified skin toxin into rabbits i.v. and determination of the LD50 indicated that the protein had been purified approximately 30 fold by these procedures. Injection of the purified skin toxin into rabbits caused agitation, convulsions and death within 5 min. Analysis of plasma levels of lactate dehydrogenase, glutamate-oxaloacetate transaminase and glutamate pyruvate transaminase in injected rabbits indicated that the skin toxin caused cardiac and liver damage to the animals.

Prostanoid synthesis in whole blood cells from fish of the Arabian Gulf

The ability to synthesise prostaglandins and thromboxane from 14C-labelled arachidonic acid was investigated in 11 species of fish from the Arabian Gulf. Cyclooxygenase activity was assessed in washed whole blood cells. Arachidonic acid and its metabolites were extracted and separated on silicic acid columns and thin layer chromatography (silica gel G). Total capacity to convert [14C]arachidonic acid to prostanoids varied from 1 to 35% among the 11 fish species studied. Gray shark (Chiloscyllium griseum) blood cells had the highest capacity (37 +/- 0.4%) to convert arachidonate into prostanoids and two species of catfish (Arius bilineatus and A. thalassinus) exhibited greater than 10% capacity to convert [14C]arachidonate into prostanoids. The major prostanoid synthesised by the two catfish (A. bilineatus and A thalassinus) was 6-keto PGF1 alpha, a stable metabolite of prostacyclin, PGI2. In contrast, A. teunispinis synthesised thromboxane B2, a stable metabolite of thromboxane A2. Thromboxane B2 (TXB2) was the major product synthesised by all three species of shark studied (Chil. griseum, Carcharhinus plumbeus, Carch. melanopterus), with 6-keto PGF1 alpha a minor product. Other fish studied showed a varied pattern of prostanoid synthesis. The synthesis of these prostanoids was almost completely blocked by preincubation of the whole blood cells from catfish and shark with indomethacin (0.5 microM) suggesting the involvement of cyclooxygenase-mediated prostanoid synthesis.

Evaluation of guided tissue regeneration in interproximal defects. (II). Membrane and bone versus membrane alone

This study clinically evaluates the use of expanded polytetrafluoroethylene (ePTFE) membranes with or without the addition of decalcified freezedried bone allograft (DFDBA) in the treatment of interproximal intraosseous defects. 25 patients (26 paired defects) diagnosed with advanced periodontitis and having at least 2 bilateral interproximal probing depths of > or = 6 mm participated in the study. After the hygiene phase, measurements were made to determine soft tissue recession, pocket depth, and clinical attachment levels. Defects from each pair were randomly treated with either ePTFE alone (control), or ePTFE+DFDBA (experimental). Measurements were made during the surgery to determine crestal resorption, defect resolution and defect fill. Membranes were removed at 4 to 6 weeks. At 6 months, the soft and hard tissue measurements (surgical reentry) were repeated. Both groups showed statistically significant improvement when compared to baseline (p < 0.001), but no difference was determined between groups. Control sites showed a 50% bone fill and experimental sites had 54% bone fill. The defect resolution changes were also similar between control and experimental groups, respectively (80%, 74%). For this short-term study, it was concluded that either technique was beneficial for the treatment of intraosseous defects. Other studies are needed to assess the long-term stability of the improvements rendered by these treatments.

Root resorptions in a patient with hemifacial atrophy

Hemifacial atrophy (Parry-Romberg syndrome) is a rare but well-recognized condition. The developmental effects on facial and oral structures have been well documented in the literature. However, the etiology of hemifacial atrophy remains unknown. Previous reported alterations in tooth growth and development include delayed tooth eruption, abnormal root morphology, and malocclusion but not root resorption. This report presents the orofacial changes from hemifacial atrophy in a 22-yr-old woman and describes the occurrence of root resorptions in two regions affected by this condition. The concurrent presence of root resorptions in both the maxilla and mandible in the regions showing the most severe dental malformations points to root resorption as an additional complication of hemifacial atrophy.

Comparative biochemical and pharmacological properties of epidermal secretions from Ariid catfish of the Arabian Gulf

1. Comparative biochemical and pharmacological studies on epidermal secretions from three species of Ariid catfish were carried out to determine whether they share common properties. 2. Protein compositions are generally similar, but show some differences in size and numbers of proteins. 3. Lipids also differ. However, seasonal and dietary changes in lipid compositions exceed the differences among species. 4. Enzymes in the secretions appear common to each fish species, though some differences are noted in relative activities. 5. Toxicity responses of rabbits to injections with secretions from each of the catfish species indicated that two were lethal, with similar lethal dose levels when injected intravenously. 6. Secretions from all three catfish induced changes in plasma enzyme levels indicative of heart and liver damage, and also induced changes in blood glucose and cholesterol levels.

Lipid composition of the epidermal gel secretion from the Arabian Gulf catfish (Arius thalassinus Ruppell)

Lipids associated with a threat induced epidermal gel secretion from the catfish, Arius thalassinus, have been analyzed. Phospholipids, neutral lipids and glycolipids are all present and each of these subclasses has been analyzed by thin layer and gas chromatography with a general similarity with membrane lipids being noted. The epidermal gel lipids differed from total liver lipids of the catfish. Fatty acid analysis showed the gel lipid to be rich in the unsaturated fatty acids: oleate (omega 7, C18:1), arachidonate (omega 6, C20:4), and docosahexaenoate (omega 3, C22:6). Some prostaglandins were quantitated in lipid extracts from the epidermal gel.

Vasoconstrictor components in the Arabian Gulf catfish (Arius thalassinus, Ruppell) proteinaceous skin secretion

The Arabian Gulf catfish (Arius thalassinus, Ruppell) produces toxic substances from its skin and from venom glands located near the base of the pectoral fins. Investigation of the pharmacological properties of the skin toxin have previously shown cholinergic vasoconstrictor activity in umbilical arteries. Cholinergic vasoconstriction was confirmed in sheep renal arteries. This activity was partially blocked by atropine, while most of the residual contraction was eliminated by simultaneous addition of indomethacin. Skin toxin treatment of arterial specimens caused a release of prostaglandin (PGE2, TXB2 and 6-keto-PGF1 alpha) into the organ bath. Prostaglandin release was blocked by pretreatment with indomethacin. Heat denaturation of skin toxin caused a loss of only the indomethacin-sensitive muscle contraction activity; most of the residual activity was blocked by atropine.

Immunologic studies of male infertility

Blood and semen samples were obtained from 13 men who had self-agglutination of spermatozoa and spermatozoal antibodies in their sera. The seminal plasma of these men produced spermatozoal immobilization and agglutination when added to normal semen from healthy men. Analysis of the seminal plasma samples showed that immunoglobulin G (IgG) levels were higher in the study group than in the control subjects. They contained IgA and complements C3 and C4, whereas only 2 of 15 samples from normal men contained IgA, and only one case contained C3 and C4. IgM was detected in 10 samples of the study group and in one sample of the control group. IgG levels in the blood of the study group were significantly higher than those in the blood of control subjects. Therefore, the immunoglobulins which probably play a role in the mechanism of autoagglutination and immobilization of spermatozoa are IgG, IgA, and IgM, and complements C3 and C4.