Genetic analysis of haemophilia A in Bulgaria

Background  

Haemophilias are the most common hereditary severe disorders of blood clotting. In families afflicted with heamophilia, genetic analysis provides opportunities to prevent recurrence of the disease. This study establishes a diagnostical strategy for carriership determination and prenatal diagnostics of haemophilia A in Bulgarian haemophilic population.     

Cystic fibrosis and the phenotypic expression of autosomal dominant polycystic kidney disease

Recent experiments in cultured cyst epithelial cells from kidneys of patients with autosomal dominant polycystic kidney disease (ADPKD) have shown that the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is present in the apical surface of these cells and mediates chloride (Cl-) and fluid secretion in vitro. To determine whether the presence of CF with the expression of mutated CFTR proteins modifies cyst formation in ADPKD, we studied a large family with both inherited diseases. ADPKD in this family is linked to PKD1. The family is composed of 26 members; 11 members with ADPKD, 4 members with CF, and 2 members with both diseases. Renal volumes measured by computerized tomography (CT), calculated creatinine clearances, and other clinical parameters in the family members with ADPKD and CF were compared with those in the family members with ADPKD alone, as well as to a large population of patients with ADPKD. The patients with CF and ADPKD, but not the CF heterozygote carriers with ADPKD, had less severe polycystic kidney and liver disease, as indicated by normal renal function; smaller renal volume, even when corrected for height and body surface area; and the absence of hypertension and liver cysts. These observations suggest that the coexistence of CF may reduce the severity of ADPKD.     

Design,synthesis, tandem mass spectrometric sequencing and biological activity of NGF mimetics

Nine low molecular weight nerve growth factor (NGF)-like peptides have been designed to mimic the putative receptor-binding epitope of NGF defined by two β-hairpin loops. Eight different spacers were used as variable links between the β-loop amino acid residues, which from mutagenesis experiments were found to play an important role in the biological activity of NGF. These spacers were amino acids, natural or non-natural, differing in length (5–13 Å) and polarity. The peptides were synthesized via the Fmoc solid-phase peptide synthesis and purified by reversed-phase HPLC. Their primary sequences were analyzed by a combination of automated Edman degradation and mass spectrometry. The peptides were tested using two different biological assays, the fibre outgrowth from chick embryonic sympathetic ganglia and the PC 12 cell differentiation assay. Weak antagonistic effects could be observed for some peptides. © Munksgaard 1996.     

MALIGNANT HYPERTHERMIA IN BELGIAN LANDRACE PIGS RESTED OR EXCERCISED BEFORE EXPOSURE TO HALOTHANE

Thirteen of 31 Belgian Landrace pigs developed malignant hyperthermia(MH) after breathing halothane. A short period of exercise 1h before the administration of the triggering agent increasedthe incidence of the syndrome to 100% in eight similar pigs.Clinical symptoms were more marked and developed more rapidlyin the exercised pigs. All the reacting pigs became typicallyacidotic, developed rigor and died. Serum Na⁺, K+, Ca2⁺, c.p.k.,l.d.h. and protein concentrations were increased to a variableextent during the reaction and there was an increase in p.c.v.also. No hyper-glycaemia was detected in pigs which were restedbefore receiving halothane. Four of the eight exercised pigsbecame markedly hyperglycaemic and plasma noradrenaline increasedto higher values. Phosphocreatine and ATP decreased to low valuesand lactate increased in the muscles of all pigs which reacted.At the time of death, muscle glycogen had decreased significantlyin the rested, but not in the exercised, MH pigs. ^*Present address: ARC Meat Research Institute, Langford, BristolBS18 7DY.     

Metabolism of xylitol in dental plaque

Abstract – It has been reported previously that xylitol added to glucose used to challenge dental plaque in vivo caused a reduced acid formation. The aim of the present study was to approach the mechanism by which xylitol may affect glucose catabolism in plaque bacteria. Suspensions of freshly collected 4-day-old plaque bacteria were ineubated, one batch with labeled xylitol, one with labeled glucose, in vitro at 37°C. Samples of cells were taken out at time intervals, collected on paper discs and subjected to scintillation counting. It was observed that the plaque bacteria took up xylitol, the uptake increasing with incubation of more than 3–4 h, whereas the same cells took up glucose immediately. Cells which had taken up xylitol were extracted with boiling water, extracts concentrated and applied on thin-layer chromatography sheets. A radioactive component with mobility like xylitol-5-phosphate was isolated from the cell extracts, and also a component where labeled xylitol was associated with macromolecules. It is suggested that the accumulation of the metabolities within the cells inhibits glycolysis.     

Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63

Waanders E, Venselaar H, te Morsche RHM, de Koning DB, Kamath PS, Torres VE, Somlo S, Drenth JPH. Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63. Polycystic liver disease (PCLD) is characterized by intralobular bile duct cysts in the liver. It is caused by mutations in PRKCSH, encoding hepatocystin, and SEC63, encoding Sec63p. The main goals of this study were to screen for novel mutations and to analyze mutations for effects on protein structure and function. We screened 464 subjects including 76 probands by direct sequencing or conformation‐sensitive capillary electrophoresis. We analyzed the effects of all known and novel mutations using a combination of splice site recognition, evolutionary conservation, secondary and tertiary structure predictions, Poly Phen , and p Mut and sift . We identified a total of 26 novel mutations in PRKCSH (n = 14) and SEC63 (n = 12), including four splice site mutations, eight insertions/ deletions, six non‐sense mutations, and eight missense mutations. Out of 48 PCLD mutations, 13 were predicted to affect splicing. Most mutations were located in highly conserved regions and homology modeling for two domains of Sec63p showed severe effects of the residue substitutions. In conclusion, we identified 26 novel mutations associated with PCLD and we provide in silico analysis in order to delineate the role of these mutations.     

Blood parasites,body condition,and wing length in two subspecies of yellow wagtail (<Emphasis Type="Italic">Motacilla flava</Emphasis>) during migration

Blood parasites of migrating yellow wagtails of two subspecies—Motacilla flava feldegg and Motacilla flava flava—were studied on a sample of 473 birds caught in spring and autumn periods in Bulgaria. We controlled eight “migration waves” (flocks captured in different evenings) of yellow wagtails for four parameters—average body mass, average fat level, average wing length, and average prevalence of different hematozoan species. Gametocytes or meronts of a total of six species of hematozoa belonging to three genera were identified—Haemoproteus motacillae, Haemoproteus anthi, Plasmodium relictum, Plasmodium subpraecox, Plasmodium cathemerium, and Tryponosoma avium. Mixed infections were detected in 31 cases, of which 14 were of H. anthi/H. motacillae type. Parasite species composition was similar in the two studied subspecies of M. flava. We did not find any significant differences in the overall infection prevalence or number of infecting parasites between M. f. flava and M. f. feldegg. Parasite prevalence and the number of co-infecting parasites in spring were much higher than in fall. Season had a strong influence on the prevalence of H. anthi and H. motacillae, and for both, there was a marginally significant interaction between subspecies and season, but not a season-independent influence of subspecies. Males of M. f. feldegg had a significantly higher overall blood parasite prevalence and prevalence of H. anthi than females. Sex-related differences in the prevalence of other parasites were not significant. Migration waves of yellow wagtails differed in overall infection status and in H. motacillae prevalence, but not for H. anthi prevalence. We also found significant differences in fat score, weight, and wing length between the studied migration waves of the yellow wagtails. Fat scores of birds infected with different hematozoa were lower compared with those of the non-infected birds. This only marginally was true for body weight and was not the case for wing length. Overall, infected birds were in worse condition (estimated as the residual weight after regression with wing length) compared with the non-infected birds, but after controlling for seasonal effects, the differences in condition appeared to be due to migration season and did not significantly differ between infected and non-infected birds caught in the same season.     

GDF 15 - A Novel Biomarker in the Offing for Heart Failure

Background:

Several diagnostic and prognostic biomarkers are being explored in heart failure. GDF-15 belongs to the transforming growth factor β (TGF-β) cytokine family that is highly up regulated in inflammatory conditions. We undertook this systematic review to summarize the current evidence on the utility of GDF-15 as a biomarker in heart failure.

Design and Methods:

Multiple electronic databases for studies that reported the association between GDF- 15 and heart failure were searched using different electronic databases such as MEDLINE, Science Direct, Springer Link, Scopus, Cochrane Reviews, and Google Scholar using pre-defined inclusion- exclusion criteria.

Results:

Twenty one original studies were identified that included data from 20,920 study participants. GDF 15 was found to be a strong prognosticator of all-cause mortality in heart failure patients. Several studies found the benefit of using GDF-15 as a component of a multi-biomarker strategy in prognosticating patients with heart failure.

Conclusion:

More studies are warranted to elucidate the molecular pathways involving GDF-15 and to see how knowledge about GDF-15 can be used to make therapeutic decisions in the clinic.     

Electroencephalographic spectral power in writer's cramp patients: evidence for motor cortex malfunctioning during the cramp

We investigated cortical activation as reflected in task-related spectral power (TRPow) changes in 8 writer's cramp patients during writing on a digital board and during isometric contraction and compared them to those of 8 age-matched healthy subjects. Scalp EEG was recorded over the contralateral primary sensorimotor area (SM1(c)), and from the ipsilateral sensorimotor area (SM1(i)). The electromyogram (EMG) was recorded from the Extensor Digitorum Communis (Extensor), Flexor Digitorum Superficialis (Flexor), and First Dorsal Interosseous (FDI) muscles. We analyzed (1) handwriting performance, (2) changes in the TRPow confined to alpha and beta band, and (3) the EMG spectral power during both tasks, writing and isometric contraction. During writing, all patients developed writer's cramp. The handwriting in writer's cramp patients was associated with significantly less reduction of the beta-range TRPow and lower frequency of the TRPow reduction compared to controls. No significant differences between patients and controls for the alpha band TRPow reduction during handwriting were observed. During writing, the patients showed higher EMG spectral power than the controls but this difference was at the border of significance. The present results indicate disorder in the motor execution system, in writer's cramp patients, associated with impaired functional beta-network state of the contra- and ipsilateral sensorimotor cortices, most probably due to inadequate modulation of the intracortical inhibition associated with writing.