The Clinical and Biochemical Predictors of Bone Mass in Preterm Infants

BackgroundMetabolic bone disease of prematurity still occurs in preterm infants, although a significant improvement in neonatal care has been observed in recent decades. Dual-energy X-ray absorptiometry (DXA) is the precise technique for assessing bone mineral content (BMC) in preterm infants, but is not widely available.AimTo investigate the clinical and biochemical parameters, including bone metabolism markers as potential predictors of BMC, in preterm infants up to 3 months corrected age (CA).ResultsThe appropriate quality DXA scans were available for 160 infants (87%) examined at term and for 130 (71%) tested at 3 mo CA. Higher iPTH level was the only independent predictor of lower BMC at term, whereas lower BMC at 3 mo CA was associated both with lower urinary phosphate excretion and higher serum osteocalcin level. ROC analysis showed that iPTH >43.6 pg/mL provided 40% sensitivity and 88% specificity in identification of preterm infants with lower BMC at term. In turn, urinary phosphate excretion (TRP>97% or UP/Cr ≤0.74 mg/mg) and serum osteocalcin >172 ng/mL provided 40% sensitivity and 93% specificity in identification of infants with decreased BMC at 3 mo CA.ConclusionSerum iPTH might to be a simple predictor of reduced BMC in preterm infants at term age, but urinary phosphate excretion and serum osteocalcin might predict reduced BMC at 3 mo CA. These results represent a promising diagnostic tool based on simple, widely available biochemical measurements for bone mass assessment in preterm infants.     

Serum alkaline phosphatase polymorphism in pigs1

Genetic variants of serum alkaline phosphatase were studied by the method of starch gel electrophoresis in the Zlotnicka Pstra breed of pigs. Two regions of alkaline phosphatase migration were observed. A single fraction in region I and four different phenotypes: AB, B, BC and BD in region II, were found. For AB, B and BC phenotypes the genetic control by three alleles AkpA, AkpB and AkpC in suggested. The observed segregation ratios in some cases deviated significantly from the expected ones.     

Cytokinin-like activity in sea water andFucus vesiculosus L

Cytokinin activity was demonstrated in the Baltic sea waters. This activity was always higher in the near-bottom water, taken from theFucus vesiculosuszone, than in the superficial zone. A cytokinin-like substance showing properties typical of 6-(3-methyl-2-butenylamino)purine (2iP) was also present in extracts from the thallus ofFucus. It was found that exogenously applied cytokinins, in some concentration ranges, markedly increased the number of adventitious branches formed on the cut surface of the thallus fragments. The growth responses of the investigated plant tissues to the different cytokinins varied according to season and kind of cytokinin applied. The possibility of exudation of some cytokinin like substances by the algal cells into the surrounding waters was considered.     

Benefits and limitations of electrocardiographic and echocardiographic screening in top level endurance athletes

The study was designed to assess the usefulness of routine electrocardiography (ECG) as well as transthoracic echocardiography (TTE) in screening top level endurance athletes. An additional goal was to attempt to identify factors determining occurrence of adaptive and abnormal changes in ECG and TTE. The retrospective analysis included basic medical data, ECG and TTE results of 262 athletes (123 rowers, 32 canoeists and 107 cyclists), members of the Polish National Team. The athletes were divided into two age groups: young (≤ 18 years; n = 177) and elite (> 18 years; n = 85). ECG and TTE measurements were analysed according to the International Recommendations from 2017 and 2015, respectively. Adaptive ECG changes were found in 165 (63%) athletes. Abnormal ECG changes were identified in 10 (3.8%) athletes. 98% of athletes exceeded TTE norms for the general population and 26% exceeded norms for athletes. The occurrence of both adaptive ECG findings and abnormalities in the TTE (in norms for athletes) was strongly associated with the years of training, hours of training per week and the age of the athlete. Male gender and the years of training were independent predictors of the ECG and TTE findings. Abnormal ECG changes were not related to the time of sport. Among 10 athletes with ECG changes, only 3 had changes in TTE and no relationship was found between abnormal finding in ECG and TTE (p = 0.45). ECG and TTE screening complement each other in identifying endurance athletes requiring treatment or verification. Unlike abnormal ECG changes, adaptive ECG changes and TTE abnormalities are strongly related to the training duration, which reflects physiological adaptation of the heart to physical exertion in high endurance athletes.     

In search of female sterility causes in the tetraploid and pentaploid cytotype of Pilosella brzovecensis (Asteraceae)

Within the agamic Pilosella complex, apomixis (asexual reproduction through seed) involves apospory, parthenogenesis, and autonomous endosperm development. Observations of reproductive biology in P. brzovecensis throughout four growing seasons in the garden have shown that both tetraploid and pentaploid plants of this species do not produce viable seeds and reproduce exclusively vegetatively by underground stolons. The reasons for the seed development failure were unknown, therefore our research focused on the analysis of reproductive events in the ovules of this taxon. We found that apospory was initiated in the ovules of both cytotypes. Multiple aposporous initial (AI) cells differentiated in close proximity to the megaspore mother cell (MMC) and suppressed megasporogenesis at the stage of early prophase I. However, none of the AI cells was able to further develop into a multi-nucleate aposporous embryo sac (AES) due to the inhibition of mitotic divisions. It was unusual that callose was accumulated in the walls of AI cells and its synthesis was most likely associated with a response to the dysfunction of these cells. Callose is regarded as the isolating factor and its surprising deposition in the ovules of P. brzovecensis may signal disruption of reproductive processes that cause premature termination of the aposporous development pathway and ultimately lead to ovule sterility. The results of our embryological analysis may be the basis for undertaking advanced molecular studies aimed at fully understanding of the causes of female sterility in P. brzovecensis.

     

High level of genetic differentiation of Juniperus phoenicea (Cupressaceae) in the Mediterranean region: geographic implications

Fourteen natural populations of Juniperus phoenicea L. from the quite entire species range have been compared using isoenzyme polymorphism. Among 17 loci, 5 (Got1, 6Pgd3, Pgi2, Pgm2 and Shdh2) appeared to be differentiated sufficiently to provide useful information for discrimination between the subspecies phoenicea and turbinata (Guss.) Nyman. Two distinct groups of populations were detected using the Nei’s genetic distance unweighted pair group method with arithmetic mean (UPGMA) and discrimination analyses, one including the inland populations of the eastern Iberian Peninsula and southern France (subsp. phoenicea), and the second from the Mediterranean and Atlantic shores, and from the Atlas mountains in Africa (subsp. turbinata). The high level of differences confirms a long period of isolation, probably during the whole Pleistocene. The population from the Aegean Sea shore differed from the other Mediterranean shore plus Atlas mountain population. It also suggests spatial isolation between them, at least during the last Glaciation.