Cell cycle and cell death are not necessary for appressorium formation and plant infection in the fungal plant pathogen Colletotrichum gloeosporioides

<p>Abstract</p> <p>Background</p> <p>In order to initiate plant infection, fungal spores must germinate and penetrate into the host plant. Many fungal species differentiate specialized infection structures called appressoria on the host surface, which are essential for successful pathogenic development. In the model plant pathogen <it>Magnaporthe grisea </it>completion of mitosis and autophagy cell death of the spore are necessary for appressoria-mediated plant infection; blocking of mitosis prevents appressoria formation, and prevention of autophagy cell death results in non-functional appressoria.</p> <p>Results</p> <p>We found that in the closely related plant pathogen <it>Colletotrichum gloeosporioides</it>, blocking of the cell cycle did not prevent spore germination and appressoria formation. The cell cycle always lagged behind the morphogenetic changes that follow spore germination, including germ tube and appressorium formation, differentiation of the penetrating hypha, and <it>in planta </it>formation of primary hyphae. Nuclear division was arrested following appressorium formation and was resumed in mature appressoria after plant penetration. Unlike in <it>M. grisea</it>, blocking of mitosis had only a marginal effect on appressoria formation; development in hydroxyurea-treated spores continued only for a limited number of cell divisions, but normal numbers of fully developed mature appressoria were formed under conditions that support appressoria formation. Similar results were also observed in other <it>Colletotrichum </it>species. Spores, germ tubes, and appressoria retained intact nuclei and remained viable for several days post plant infection.</p> <p>Conclusion</p> <p>We showed that in <it>C. gloeosporioides </it>the differentiation of infection structures including appressoria precedes mitosis and can occur without nuclear division. This phenomenon was also found to be common in other <it>Colletotrichum </it>species. Spore cell death did not occur during plant infection and the fungus primary infection structures remained viable throughout the infection cycle. Our results show that the control of basic cellular processes such as those coupling cell cycle and morphogenesis during fungal infection can be substantially different between fungal species with similar lifestyles and pathogenic strategies.</p

Fluid management during video-assisted thoracoscopic surgery for lung resection: A randomized, controlled trial of effects on urinary output and postoperative renal function

BackgroundIncreased perioperative fluid administration is an independent risk factor for lung injury after pulmonary resection. In clinical practice, fluid therapy is heavily guided by urinary output; however, diuretic response to plasma volume expansion has been reported to be blunted during anesthesia and surgery. We therefore hypothesized that in patients undergoing video-assisted thoracoscopic surgery, different regimens of intraoperative fluid management would not affect urinary output as would be expected in the nonsurgical scenario. Moreover, a restrictive perioperative fluid approach, as indicated in these operations, will not harm renal function.MethodsOne hundred two patients undergoing video-assisted thoracoscopic surgery were randomly allocated to receive intraoperatively either high (8 mL/[kg · h]; n = 51) or low (2 mL/[kg · h]; n = 51) amounts of Ringer's lactate solution. The primary end point was intraoperative urinary output. Secondary end points included postoperative creatinine serum levels and postoperative complication rate.ResultsDemographic and surgical data were comparable between groups. Regardless of the intraoperatively fluids administered (mean ± SD, 2131 ± 850 vs 1035 ± 652 mL in high and low groups, respectively; P < .0001), urinary output was similar (median 300 mL). Perioperative creatinine serum levels decreased significantly postoperatively and were not significantly different among the groups.ConclusionsIn patients undergoing video-assisted thoracoscopic surgery, intraoperative urinary output and postoperative renal function are not affected by administration of fluids in the range of 2 to 8 mL/(kg · h). The clinical practice of administering fluids to enhance diuresis in the perioperative period should therefore be abandoned

Updated View on the Relation of the Pineal Gland to Autism Spectrum Disorders

Identification of the biological features of autism is essential for designing an efficient treatment and for prevention of the disorder. Though the subject of extensive research, the neurophysiological features of autism remain unclear. One of the proposed biological causes of autism is malfunction of the pineal gland and deficiency of its principal hormone, melatonin. The main function of melatonin is to link and synchronize the body's homeostasis processes to the circadian and seasonal rhythms, and to regulate the sleep-wake cycle. Therefore, pineal dysfunction has been implicated based on the common observation of low melatonin levels and sleep disorders associated with autism. In this perspective, we highlight several recent findings that support the hypothesis of pineal gland/melatonin involvement in autism. Another common symptom of autism is abnormal neuroplasticity, such as cortical overgrowth and dendritic spine dysgenesis. Here, we synthesize recent information and speculate on the possibility that this abnormal neuroplasticity is caused by hyperactivity of endogenous N,N-dimethyltryptamine (DMT). The pineal gland was proposed as the source of DMT in the brain and therefore, our assumption is that besides melatonin deficiency, pineal dysfunction might also play a part in the development of autism through abnormal metabolism of DMT. We hope that this manuscript will encourage future research of the DMT hypothesis and reexamination of several observations that were previously attributed to other factors, to see if they could be related to pineal gland/melatonin malfunction. Such research could contribute to the development of autism treatment by exogenous melatonin and monitored light exposure

Coherent electronic transport through a superconducting film

We study coherent quantum transport through a superconducting film connected to normal-metal electrodes. Simple expressions for the differential conductance and the local density of states are obtained in the clean limit and for transparent interfaces. Quasiparticle interference causes periodic vanishing of the Andreev reflection at the energies of geometrical resonances, subgap transport, and gapless superconductivity near the interfaces. Application of the results to spectroscopic measurements of the superconducting gap and the Fermi velocity is analyzed.Comment: 5 pages, 4 figure

Long-term outcomes of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump

ObjectiveMost studies describing the outcome of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump (IABP) have reported early results. The purpose of our study was to evaluate the early and long-term results.MethodsOf 2658 isolated coronary artery bypass grafting procedures performed from 1996 to 2001, 215 were supported preoperatively with an IABP. The indications for IABP insertion were cardiogenic shock in 18 (8.4%), acute evolving myocardial infarction in 38 (17.7%), clinical instability in 84 (39.1%), and critical coronary lesions in 75 (34.9%).ResultsOperative mortality was 12.6%. The mortality of the cardiogenic shock patients was greater (22.2%; P = .174). Logistic regression analysis showed patient age (odds ratio, 1.057; 95% confidence interval, 1.010-1.108) and cardiopulmonary bypass (CPB) time (odds ratio, 1.020; 95% confidence interval, 1.008-1.031) were associated with increased operative mortality. An increased number of bypass grafts had a protective effect (odds ratio, 0.241; 95% confidence interval, 0.113-0.515). The actual early mortality was lower than the logistic EuroSCORE calculated mortality (12.6% vs 32.8%, P < .0001). The mean follow-up was 8 ± 4 years. The Kaplan-Meier 10-year survival was 49%. The Cox adjusted overall (early and late) survival and major adverse cardiac events-free survival of the different IABP subgroups was similar. Cox analyses showed peripheral vascular disease, off-pump coronary artery bypass surgery, age, CPB time, female gender, and fewer bypass grafts were associated with decreased survival.ConclusionsIn patients supported preoperatively with an IABP, better early and long-term results were strongly related to younger age, a shorter CPB time, and a greater number of bypass grafts. Avoiding the use of CPB (off pump) in these emergency cases is not recommended

Role of Interfaces in the Proximity Effect in Anisotropic Superconductors

We report measurements of the critical temperature of YBCO-Co doped YBCO Superconductor-Normal bilayer films. Depending on the morphology of the S-N interface, the coupling between S and N layers can be turned on to depress the critical temperature of S by tens of degrees, or turned down so the layers appear almost totally decoupled. This novel effect can be explained by the mechanism of quasiparticle transmission into an anisotropic superconductor.Comment: 13 pages, 3 figure

Повторные измерения толщины слоя нервных волокон с помощью оптического когерентного томографа Stratus

PURPOSE: Assessment of optic disc damage is an essential part of the ocular examination and differential diagnosis between the patient with ocular hypertension and pre-perimetric or perimetric glaucoma. The Stratus optic coherent tomograph (Carl Zeiss Meditec, Inc, Dublin, Calif) is still one of the most used optic nerve imaging technology throughout the world. Therefore, the development of methodology that enhances the utility of optic disc measurements with the Stratus OCT remains a relevant and meaningful goal. In an attempt to determine the optimal number of repeated measurements we investigated how the average of three sets of manually repeated measurements of retina nerve firer layer (RNFL) thickness would compare with a single set. METHODS: A total of 73 individuals (136 eyes) aged 55.3±15.2 years with ocular hypertensive (OHT), pre-peri-metric glaucoma or glaucoma were included in the final analysis. When the data was evaluated using a quadrant analysis we observed that 13.6% of the patients exhibited a clinically meaningful difference of 20% or more in the serial RNFL thickness measurements. RESULTS: The difference ranged from 9.3 to 32.7 microns and in 10 of the 12 quadrants the averaged measurement exceeded the initial measurement. Most of the differences demonstrated in this study occurred in the horizontal meridian and are probably a result of instinctive saccadic eye movements. A difference in the vertical meridian (superior and/or inferior quadrants) which is the more relevant meridian for changes in glaucoma was seen in only 3 patients (4.1%). CONCLUSIONS: One reliable RNFL measurement would be sufficient in most of these cases because in 95.9% of the cases the differences observed for the vertical meridian were less than 20%. Nevertheless, it is important to recognize that there can be more variability in the horizontal meridian and that in cases with visual loss encroaching on fixation serial measurements may be useful. At any rate, as with all ancillary tests, whenever a change is detected, it is wise to repeat the test to verify the results.ЦЕЛЬ. Оценка изменений в диске зрительного нерва является важной частью офтальмологического обследования и дифференциальной диагностики у пациентов с офтальмогипертензией и ранней и развитой стадиями глаукомы. Оптический когерентный томограф Stratus (Carl Zeiss Meditec, Inc, Dublin, Calif) до сих пор является одним из самых часто используемых приборов для визуализации зрительного нерва по всему миру. Поэтому разработка методологии, оптимизирующей оценку состояния диска зрительного нерва с помощью Stratus, остается важной и актуальной задачей. В попытке определить оптимальное количество последовательных измерений, мы сравнивали результаты одиночного измерения толщины слоя нервных волокон с усредненными результатами серии из трех последовательных измерений. методы. Всего в исследовании участвовало 73 пациента (136 глаз) в возрасте 55,3±15,2 года с офтальмогипертензией или диагностированной глаукомой. При анализе полученных данных по квадрантам поля зрения у 13,6% пациентов было обнаружено клинически значимое различие ≥ 20% в толщине слоя нервных волокон. РЕЗУЛЬТАТЫ. Разница в измерениях составляла от 9,3 до 32,7 мкм, и в 10 из 12 квадрантов усредненный результат трех последовательных измерений превышал результат единичного измерения. В большинстве случав различие отмечалось в горизонтальном меридиане и, вероятно, являлось результатом естественных саккадных движений. Различие в результатах по более значимому для изменений поля зрения при глаукоме вертикальному меридиану (верхние и/или нижние квадранты) наблюдалось только у 3 (4,1%) пациентов. ЗАКЛЮЧЕНИЕ. Поскольку в 95,9% случаев разница результатов по вертикальному меридиану не превышает 20%, можно сделать вывод, что в большинстве случаев достаточно одного достоверного измерения толщины слоя нервных волокон сетчатки. Тем не менее полезно помнить о большей вариабельности результатов по горизонтальному меридиану. Например, в случае со снижением зрения, затрудняющим фиксацию взгляда, может быть полезным проведение серии из нескольких исследований подряд. В любом случае при появлении изменений в результатах этого или других вспомогательных исследований наилучшей тактикой является повторение исследования для подтверждения результатов