A 192-heme electron transfer network in the hydrazine dehydrogenase complex.

Anaerobic ammonium oxidation (anammox) is a major process in the biogeochemical nitrogen cycle in which nitrite and ammonium are converted to dinitrogen gas and water through the highly reactive intermediate hydrazine. So far, it is unknown how anammox organisms convert the toxic hydrazine into nitrogen and harvest the extremely low potential electrons (-750 mV) released in this process. We report the crystal structure and cryo electron microscopy structures of the responsible enzyme, hydrazine dehydrogenase, which is a 1.7 MDa multiprotein complex containing an extended electron transfer network of 192 heme groups spanning the entire complex. This unique molecular arrangement suggests a way in which the protein stores and releases the electrons obtained from hydrazine conversion, the final step in the globally important anammox process.

Pregnancy and Obstetrical Outcomes in Women Over 40 Years of Age.

Introduction: Delayed childbearing is increasing, and advanced maternal age has been associated with an increased risk of obstetrical complications. The purpose of this study was to evaluate pregnancy outcomes in women with advanced maternal age (≥ 40 years). Methods: Maternal and obstetrical data were collected from the Department of Obstetrics and Gynecology of the University of Wuerzburg for the period from 2006 to 2011. In this retrospective analysis we compared the outcomes for women aged ≥ 40 years (n = 405) with those of three younger subgroups (I: < 30 y; II: 30-34 y; III: 35-39 y). Results: Pregnant women older than 40 years had more chronic diseases such as hypertension, needed medical treatment more frequently and had a higher thrombosis risk. Pregnancy-induced diseases such as gestational diabetes, preeclampsia and pregnancy-associated hypertension occurred more often in women ≥ 40 years of age. Compared to mothers who were younger than 30 years, primiparous women ≥ 40 years had a more than four times higher overall cesarean section rate and four times higher elective cesarean section rate. Furthermore, they required longer hospital stays, both after cesarean section and after vaginal delivery. The preterm birth rate (≤ 32 weeks of gestation) was similar across the different age groups. Conclusions: The outcomes of pregnancy and childbirth and for newborns born to women ≥ 40 years did not vary significantly from those of younger women if the following conditions were met: a) pre-existing chronic diseases were treated medically and dietetically; b) pregnancy-induced morbidity was monitored regularly and controlled medically; c) women attended regular prenatal check-ups; d) a healthy lifestyle was adhered to during pregnancy, and e) delivery occurred in a perinatal center.

B cell epitopes of gliadin.

A phage displayed dodecapeptide library and synthetic octapeptides spanning the complete sequence of alpha- and gamma-type gliadin and overlapping in six amino acids (pepscan) were screened for binding to human gliadin antibodies (AGA). Phage display experiments led to four sequences recognized with significantly higher frequency by sera with raised IgA-AGA titres than by control sera. All these peptides contained the core sequence PEQ. Pepscan experiments revealed binding of AGA to five prominent regions: (i) QXQPFP (binding to IgG and IgA, X representing P, Q, and L); (ii) IPEQ (IgG) and WQIPEQ (IgA); (iii) FFQP (IgG) and QGXFQP (IgA, X representing F and S); (iv) PQQLPQ (IgG and IgA), all in alpha-type gliadin; and (v) QPQQPF (IgG and IgA) in gamma-type gliadin. In two of the sequences (QPQQPF and QQQPFP), substitution of Q by E resulting in QPEQPF and QEQPFP, respectively, increased significantly binding of AGA from sera of patients with biopsy-proven or suspected coeliac disease (CoD), all positive for endomysium antibodies (EmA). In contrast, binding of sera with high AGA titre from EmA-negative patients (CoD and dermatitis herpetiformis excluded) was not enhanced by this substitution. Thus, AGA directed against these modified epitopes can be regarded as specific for CoD. This is the first study demonstrating that deamidation of gliadin improves reactivity of AGA of CoD patients.

Efficacy of cultured epithelial autografts in pediatric burns and reconstructive surgery.

BACKGROUND: Cultured epithelial autografts are regularly used in burn patients, but they have not been tested in patients undergoing reconstructive surgery. The aim of this study was to analyze and compare the efficacy of cultured grafts in both burn and reconstructive surgery patients. METHODS: In six children with severe and massive burns, full-thickness areas were grafted with cultured grafts. In another six children with hypertrophic or hyperpigmented scars, or both, cultured grafts were used to cover defects resulting from scar excision or deep dermabrasion. RESULTS: In burn surgery the final cover rate averaged 60% (range, 0% to 100%). The functional and cosmetic results were good and at least equivalent to results after conventional grafting. Fragility, infection, and, in particular, mechanical instability of cultured grafts during the first weeks after transplantation were the main problems encountered. In reconstructive surgery the final cover rate was 100% in all patients. The functional and cosmetic results were very good and considered better than those obtained by using conventional grafting techniques. No major management problems were encountered. CONCLUSIONS: In massively burned children, cultured epithelial autografts represent an effective additional and potentially lifesaving method to conventional grafting. Questions remain regarding the use of this technique to treat less severe burns. For resurfacing-type scar revisions, cultured epithelial autografts yield excellent results that appear to be superior to those of conventional techniques.

[Total thyroxine (T4) and free thyroxine (FT4) in hypothyroidism and nonthyroid diseases of dogs]. / Gesamtthyroxin (T4) und freies Thyroxin (FT4) bei Hypothyreose und nichtthyreoidalen Krankheiten des Hundes.

In 1548 dogs total and free thyroxine were determined. 559 of these dogs had been divided into 13 groups: 130 were healthy dogs, 22 suffered from hypothyroidism, two from hyperthyroidism, 405 from various other internal diseases. The other 989 dogs did not belong to one of the groups of interest or could not be attached to a certain group. In all hypothyroid dogs FT4-values were hypothyroid, whereas T4 was hypothyroid just in 16 cases; the other six values were located in the "gray area", which is supposed to be 1.2 to 1.8 micrograms/dl (15 to 23 nmol/l). Many dogs with other diseases expressed low T4- and/or FT4-values, too. Low hormone values could be measured especially in case of severe diseases. If the clinical symptoms corresponded to hypothyroidism and both T4 and FT4 were situated in the hypothyroid area, hypothyroidism is generally assumed. In all the other cases further diagnostic procedures must be performed.

[Serum cholesterol in the dog]. / Untersuchungen zum Serum-Cholesterin des Hundes.

The reference values of cholesterol were examined in two groups of healthy dogs. In a group of 591 dogs a value of 122-389 mg/dl or 3.2-10.1 mmol/l was calculated (95% percentile). Statistically significant variations occurred with age, sex, breed, and feeding; however they were small and do not require consideration in diagnostic procedures. Serum cholesterol is increased in numerous diseases. It is questionable whether the consideration of serum cholesterol helped in the diagnosis of hypothyroidism.

[The determination of free thyroxine (FT4) in dog serum]. / Die Bestimmung des Freien Thyroxins (FT4) in Hundeserum.

Free thyroxine (FT4) was determined in canine serum by use of a commercially available test kit. The measurement of intra- and interassay precision showed very good results. Accuracy was examined by adding known amounts of thyroxine and by biological response testing. The results were also good. The reference value was determined in 129 dogs. It was calculated on the basis of a 95% percentile, and ranged from 0.6 to 3.7 ng/dl (7.7 to 47.4 pmol/l).

[The diagnosis of hypothyroidism in dogs with Larsson's FT4-cholesterol test]. / Zur Diagnostik von Hypothyreosen beim Hund mit dem FT4-Cholesterin-Test nach Larsson.

The FT4-cholesterol test (Larsson) is able to distinguish hypothyroid from healthy dogs. In dogs suffering from nonhypothyroidal diseases the test cannot be used since the values overlap with those of hypothyroid dogs. The reason is seen in an influence of numerous other diseases resulting in hypercholesterolaemia as well as a decrease of FT4.

Urinary oxalate and glycolate excretion in healthy infants and children.

The molar ratios of oxalate and glycolate over creatinine were determined in single urine samples of 26 infants and 27 children aged 1-5 years. In 135 children aged 5-16 years, two urine specimens were collected, one before breakfast and one at noon. Oxalate was determined by oxalate oxidase, and glycolate was measured by a colorimetric method (improved chromatotropic acid--sulphuric acid assay after prior purification by cation and anion exchanger). Both ratios (expressed in mmol/mol creatinine and analysed on a log-normal basis) were highest in infants 0-6 months old [mean oxalate 147 (95% confidence interval: 60-360), mean glycolate 175 (72-425)]. The mean oxalate ratio was 72 mmol/mol (29-174) at the age of 7-24 months, 44 (19-101) at the age of 2-5 years and 22 (12-40) in adolescents aged 16 years. Molar glycolate ratios were higher, but disclosed the same pattern. Oxalate and glycolate ratios in fasting urines did not differ significantly from those in noon samples (except glycolate in the oldest age group). Oxalate ratios correlated well with glycolate ratios in children up to 5 years of age only. Random urine samples are thus suitable for screening. However, interpretation of data requires use of age-specific reference values that are based on comparable methods.