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The B chromosomes of maize typically undergo nondisjunction during the second microspore division (generative cell division). When the microspore nucleus contains only one B chromosome, two kinds of sperm result, one with two B chromosomes and one with no B chromosomes. The sperm with the B chromosomes preferentially fertilizes the egg cell. Previous studies of these phenomena have been limited to genetic analysis and chromosome spreads. In this study we show that a B chromosome-specific probe can be used with fluorescence in situ hybridization (FISH) analysis to detect the presence, location, and frequency of B chromosomes in intact interphase nuclei within mature pollen of maize. Using genetic line TB-10L18, our results indicate that nondisjunction of the B centromere occurs at an average frequency of 56.6%, based on four plants and 1306 pollen grains analyzed. This is consistent with the results of genetic studies using the same B-A translocation. In addition, our results suggest that B chromosome nondisjunction can occur during the first microspore division. Spatial distribution of the B chromosome-specific probe appears to be largely confined to one tip of the sperm nucleus, and a DNA fragment found outside the pollen nuclei often hybridizes to the B chromosome-specific probe.

Background: Large sessile colorectal adenomas (>/=2 cm in size) resected piecemeal have a 0% to 55% rate of residual adenoma at the first follow-up. Guidelines recommend inspection of the polypectomy site 3 to 6 months after resection. Some patients with a negative examination at 3 to 6 months have a subsequent 'late' recurrence. Objective: Our aim was to describe long-term follow-up of large sessile adenomas after piecemeal resection and to report the incidence and predictors of 'late' recurrence. Design: A retrospective study. Setting: A tertiary-referral center. Patients and Interventions: Large sessile colorectal adenomas were identified through an endoscopic database. Polyps were resected by piecemeal technique; flat areas that could not be snared were treated with argon plasma coagulation. Patients who completed follow-up examinations at our center 3 to 6 months and at least 1 year after initial resection were included. Main Outcome Measurements: 'Late' adenoma recurrence. Results: Of 136 polyps with complete follow-up, 24 (17.6%) had macroscopically evident residual adenoma at follow-up, including 18 at the first follow-up and 6 (4.4%) with a 'late' recurrence. Among 94 polyps with no visible adenoma and with negative biopsy specimens of the scar at the first follow-up, 92 polyps (97.9%) were eradicated at late follow-up, compared with 36 of 42 (85.7%) of the remaining polyps (P = .005). Limitation: A retrospective design. Conclusion: Our results confirm the phenomenon of 'late' recurrences after endoscopic piecemeal resection of large sessile adenomas. However, a normal macroscopic appearance of the polypectomy site and negative scar biopsy specimens at the first follow-up is predictive of long-term eradication. [ABSTRACT FROM AUTHOR]

Most of our knowledge about the regulation and function of sleep is based on studies in a restricted number of mammalian species, particularly nocturnal rodents. Hence, there is still much to learn from comparative studies in other species. Birds are interesting because they appear to share key aspects of sleep with mammals, including the presence of two different forms of sleep, i.e. non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. We examined sleep architecture and sleep homeostasis in the European starling, using miniature dataloggers for electroencephalogram (EEG) recordings. Under controlled laboratory conditions with a 12:12 h light-dark cycle, the birds displayed a pronounced daily rhythm in sleep and wakefulness with most sleep occurring during the dark phase. Sleep mainly consisted of NREM sleep. In fact, the amount of REM sleep added up to only 1~2% of total sleep time. Animals were subjected to 4 or 8 h sleep deprivation to assess sleep homeostatic responses. Sleep deprivation induced changes in subsequent NREM sleep EEG spectral qualities for several hours, with increased spectral power from 1.17 Hz up to at least 25 Hz. In contrast, power below 1.17 Hz was decreased after sleep deprivation. Sleep deprivation also resulted in a small compensatory increase in NREM sleep time the next day. Changes in EEG spectral power and sleep time were largely similar after 4 and 8 h sleep deprivation. REM sleep was not noticeably compensated after sleep deprivation. In conclusion, starlings display signs of NREM sleep homeostasis but the results do not support the notion of important REM sleep functions., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society.)

Sleep is considered to be of crucial importance for performance and health, yet much of what we know about sleep is based on studies in a few mammalian model species under strictly controlled laboratory conditions. Data on sleep in different species under more natural conditions may yield new insights in the regulation and functions of sleep. We therefore performed a study with miniature electroencephalogram (EEG) data loggers in starlings under semi-natural conditions, group housed in a large outdoor enclosure with natural temperature and light. The birds showed a striking 5-h difference in the daily amount of non-rapid-eye-movement (NREM) sleep between winter and summer. This variation in the amount of NREM sleep was best explained by night length. Most sleep occurred during the night, but when summer nights became short, the animals displayed mid-day naps. The decay of NREM sleep spectral power in the slow-wave range (1.1-4.3 Hz) was steeper in the short nights than in the longer nights, which suggests that birds in summer have higher sleep pressure. Additionally, sleep was affected by moon phase, with 2 h of NREM sleep less during full moon. The starlings displayed very little rapid-eye-movement (REM) sleep, adding up to 1.3% of total sleep time. In conclusion, this study demonstrates a pronounced phenotypical flexibility in sleep in starlings under semi-natural conditions and shows that environmental factors have a major impact on the organization of sleep and wakefulness., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Standard heart-lung machines lead to substantial hemodilution with associated impaired organ function and increased need for blood transfusions. The aim of this study was to evaluate the effect of the new PRECiSe low prime volume system on perioperative myocardial damage, hemodilution, and transfusions. In a case-matched prospective study, 40 patients undergoing coronary artery bypass surgery using PRECiSe were compared with 40 patients on a standard heart-lung machine. In the PRECiSe group, the prime volume was significantly reduced, resulting in less hemodilution and transfusion requirements during and after extracorporeal circulation: only 10% of patients needed transfusions vs. 35% in the control group, with an average transfusion need of 0.16 vs. 1.25 units. There were no significant differences in perioperative cardiac-specific enzymes. The PRECiSe system was considered safe and effective for coronary artery bypass surgery.

Hemodilution by the crystalloid priming volume of standard heart-lung machines in cardiac surgery is associated with impaired organ function and increased blood transfusion requirements. The aim of this study was to evaluate the effect of the use of the newly developed priming reduced extracorporeal circulation setup (PRECiSe) on perioperative hemodilution and transfusion requirements. In a matched prospective study, 40 patients who underwent operations with the PRECiSe in elective primary coronary artery bypass surgery were compared with 40 patients who underwent operations with the standard heart-lung machine. A significant reduction in final priming volume resulted in a significantly reduced degree of hemodilution and transfusion requirements during and after extracorporeal circulation. In the PRECiSe group, only 10% of the patients needed transfusions during their hospital stay, whereas 35% of the patients in the control group required any transfusion (P < .05). The average transfusion per patient was 0.16 units in the PRECiSe group and 1.25 units in the control group (P < .05). The PRECiSe was demonstrated to be safe and effective in coronary artery bypass surgery with respect to transfusion requirements and hemodilution, as well as with regard to patient safety, as represented by perioperative myocardial performance.

Studies using classic genetics as well as restriction fragment length polymorphism analysis have demonstrated that rye, unlike most flowering plants, has biparental inheritance of both plastids and mitochondria. Yet, a previous in-depth ultrastructural study found no plastids in rye sperm cells, and DNA-specific staining revealed no cytoplasmic DNA in the male gametes of this plant. In the present study, we examined serial ultrathin sections of eight rye sperm cells (four pairs) and found unambiguous examples of plastids in all cases. The number of plastids per sperm cell varies from two to 12. The sperm of a pair may vary with regard to plastid number; however, these differences are not consistent among the sperm pairs examined.