Neural crest derivatives in ocular and periocular structures

In vertebrates, the eye is an ectodermal compound structure associating neurectodermal and placodal anlagen. In addition, it benefits early on from a mesenchymal ectoderm-derived component, the neural crest. In this respect, the construction of chimeras between quail and chick has been a turning point, instrumental in appraising the contribution of the cephalic neural crest to the development of ocular and periocular structures. Given the variety of crest derivatives underscored in the developing eye, this study illustrates the fascinating ability of this unique structure to finely adapt its differentiation to microenvironmental cues. This analysis of neural crest cell contribution to ocular development emphasizes their paramount role to design the anterior segment of the eye, supply refracting media and contribute to the homeostasy of the anterior optic chamber.     

Quantitative assessment of degenerative changes in soleus muscle after hindlimb suspension and recovery

The aim of this study was to quantify the degenerative and regenerative changes in rat soleus muscle resulting from 3-week hindlimb suspension at 45° tilt (HS group, n = 8) and 4-week normal cage recovery (HS-R group, n = 7). Degenerative changes were quantified by microscope examination of muscle cross sections, and the myosin heavy chain (MHC) composition of soleus muscles was studied by sodium dodecyl sulphate polyacrylamide gel electrophoresis. At the end of 3-week hindlimb suspension, histological signs of muscle degenerative changes were detected in soleus muscles. There was a significant variability in the percentage of fibres referred to as degenerating (%dg) in individual animals in the HS group [%dg = 8.41 (SEM 0.5)%, range 4.66%–14.08%]. Moreover, %dg varied significantly along the length of the soleus muscle. The percentage of fibres with internal nuclei was less than %dg in HS-soleus muscles [4.12 (SEM 0.3)%, range 1.24%–8.86%]. In 4-week recovery rats, the greater part of the fibres that were not referred to as normal, retained central nuclei [15.8 (SEM 2.2)%, range 6.2%–21.1%]. A significant increase in the slow isoform of MHC was recorded in the HS-R rats, compared to muscles from age-matched rats (P < 0.01). These results would suggest that a cycle of myofibre degeneration-regeneration occurred during HS and passive recovery, and that the increased accumulation of slow MHC observed in soleus muscles after recovery from HS could be related to the prevalence of newly formed fibres. Accepted: 14 October 1996     

Quantitative radionuclide assessment of total pulmonary vascular volume changes

Current techniques do not permit continuous and noninvasive assessments of changes in total pulmonary intravascular volume. Hence, the present study was undertaken to determine whether quantitative radionuclide imaging can be used to determine the direction and estimate the magnitude of total pulmonary vascular volume changes. The pulmonary circulation was separately perfused at a constant rate via the pulmonary artery and drained at a constant pressure via the left atrium in nine dogs. Changes in pulmonary intravascular volume were recorded as reciprocal changes in extracorporeal reservoir volume during phenylephrine or isoproterenol administration, a 20% increase in pulmonary artery flow or a 5 mmHg (1 mmHg = 133.32 Pa) decrease in left atrial pressure. Erythrocytes were labeled with technetium-99m and pulmonary volume changes were determined from tissue attenuation, blood radioactivity, and changes in total pulmonary radioactivity obtained with a gamma-camera. During each of the interventions, count changes correlated with volume changes (r greater than or equal to 0.75). The technique reliably detected volume changes as small as 10 mL. For all 531 individual pairs of radionuclide- and reservoir-determined volume changes, the correlation between reservoir-determined and radionuclide-estimated pulmonary intravascular volume changes was 0.87. The standard error of the radionuclide estimate was 21 mL. Hence, the present study demonstrates that quantitative radionuclide imaging can be used to continuously and noninvasively determine total pulmonary vascular volume changes.     

Quantitative assessment of cellular changes provoked by microwave enhanced fixation of parathyroids

Rat parathyroids fixed by microwave enhancement, i.e. microwave irradiation in the presence of glutaraldehyde for 8 s and postfixation with OsO4 after a delay of 5 min, were compared with parathyroids fixed by perfusion with glutaraldehyde followed by immersion in glutaraldehyde and finally in OsO4. Morphometric analysis revealed that microwave enhanced fixation led to a larger mean cell volume, to larger cell surface area, and to larger surface area in membranes of RER and secretory granules. Though it is not known by which method parathyroid cells are conserved closer to the living state it is obvious that microwave enhanced fixation retains more membranes but provokes centrifugal dislocation of membranes mimicking exocytosis.     

Quantitative assessment of cellular changes provoked by microwave enhanced fixation of parathyroids

Summary Rat parathyroids fixed by microwave enhancement, i.e. microwave irradiation in the presence of glutaraldehyde for 8 s and postfixation with OsO₄ after a delay of 5 min, were compared with parathyroids fixed by perfusion with glutaraldehyde followed by immersion in glutaraldehyde and finally in OsO₄. Morphometric analysis revealed that microwave enhanced fixation led to larger mean cell volume, to larger cell surface area, and to larger suface area in membranes of RER and secretory granules. Though it is not known by which method parathyroid cells are conserved closer to the living state it is obvious that microwave enhanced fixation retains more membranes but provokes centrifugal dislocation of membranes mimiking exocytosis.     

Rimexolone控制白内障术后眼内炎症的Meta分析

目的：目的：对1％rimexolone滴眼液控制白内障手术相关性眼内炎症的疗效进行系统评价。方法：对两项多中心随机双盲对照临床研究进行Eeta分析。根据前瞻治疗分析模型对资料进行提取。通过计算机治疗3效应和比值来评估1％rimexolone滴眼液的治疗的治疗效果。并按照固定效应模型对两项研究的结果进行合并。结果：总计对357例患者进行有效性分析。在治疗结束时,炎症消失,治疗失败的合并比值比分别为3．28[95％CI2．10,5．11]0．13[95％CI0．05,0．33],前房炎症的合并治疗效应为－1．30[95％（CI－1．67,－0．93]。Rimexolone治疗相关副作用发生率为7．5％,而安慰剂高达33．3％,两组的眼内压改变没有显著性差异。结论：1％rimexolone滴眼液是一种既安全又有效的控制手术相关性眼内炎症的药物。     

Proteomic analysis of human tears: defensin expression after ocular surface surgery

Human tear protein profiles were monitored by surface enhanced laser desorption/ionization-time-of-flight mass spectrometry ProteinChip technology (SELDI-TOF ProteinChip) and liquid chromatography-mass spectrometry (LC-MS). Tears were collected from 21 patients scheduled for surgery to remove an ocular surface neoplasm prior to surgery (day 0) and on days 1, 3, and 30 postoperatively. Using this proteomic approach, we verified that three human alpha-defensins (HNP-1, HNP-2, and HNP-3) were significantly up-regulated in their expression after surgery and that their levels decreased to approximately normal by day 30 by which time healing was complete. Further confirmation of the identity of the alpha-defensins in human tears was made by LC purification, trypsin digestion, and ESI-MS/MS analysis of their tryptic digests. The concentrations of HNP-1 and HNP-2 were determined and shown to be markedly increased after ocular surface surgery. The results of the study suggest that human alpha-defensins HNP-1, HNP-2, and HNP-3 are up-regulated after surgery, and may in addition to their antimicrobial properties have an important role in wound healing.     

Retrospective analysis of reconstruction techniques after periocular basalioma excision

The paper presents our approach to reconstruction after periocular basalioma (pBCC) excision, especially of large lower lid (LL) and medial canthal (MC) pBCC. Retrospective analysis of data of 123 patients with pBCC, confirmed on histologic examination (HE), operated in period from 1998 to 2006, was performed. Oncologic safety margins of 3 mm were marked after local anesthesia was administered. Reconstruction was done in time of surgery. In pBCC away from a lid margin, adjacent myocutaneous flaps were used. For lid margin involving (LM) pBCC, size of 10 mm and less in horizontal diameter (HD), full-thickness lid excision was performed, combined with lateral canthotomy and/or Tenzel or McGregor flap. When size of LM pBCC was more than 10 mm in HD and it was on a LL, ipsilateral upper lid (UL) tarsoconjunctival (TC) graft combined with single pedicle transposition myocutaneous flap were used. The same size of LM pBCC on a UL required ipsilateral full-thickness LL "switch" flap and/or contralateral LL Hübner graft. In MC pBCC combined approach was used. The follow-up was up to 5 years. The 19 patients (15.4%) had positive tumor margin on HE. Five of them refused further surgery, but only two had recurrence. The rest of 121 patients had no recurrence during follow-up. In 5/14 patients, who underwent additional surgery, no tumor cells were found on HE. The 10/123 patients (8.1%) had complications. The imperative of our approach to reconstruction after pBCC was good functional and cosmetic result, avoiding prolonged lid closure. Accordingly, in large LL LM pBCC we used ipsilateral UL TC graft combined with single pedicle transposition myocutaneous flap. In MC pBCC combined approach was mandatory.     

The modern concepts of osseous tissue changes in spaceflight

This paper examines possible physiological mechanisms responsible for the loss of bone tissue associated with spaceflight. The authors apply the philosophical theories of V.I. Vernadsky to develop some models or algorithms of the body's functional systems and how they relate to bone loss. Loss of bone mineral content is discussed with relation to the functioning of other systems and organs, such as the liver, lungs, kidneys, endocrine system, etc. Coefficients of correlation are presented and discussed.     

心脏手术后视幻觉发生与肠道菌群变化的研究

目的探究心脏术后患者视幻觉症状发生情况及体内肠道菌群变化。方法选取2020年1月-2021年1月中国科学院大学宁波华美医院接受择期体外循环心脏手术的成年患者21例作为研究对象。分别在术前、术后第1次或第2次排便、术后6～8 d进行微生物分析和粪便短链脂肪酸(SCFAs)浓度测定。采用实时荧光定量PCR法检测肠道菌群组成,高效液相色谱检测SCFAs。术后1周进行视幻觉评价。结果21例患者中,视幻觉3例。与术前相比,术后第1和第2份粪便样本的微生物总数显著降低(P<0.05)。在专性厌氧菌中,第一次术后粪便样本中的球形梭菌数量、柔嫩梭菌数量显著低于术前样本。兼性厌氧菌中,术后第1次和第2次标本的乳酸杆菌总数均显著降低。植物乳杆菌数量在第1次术后粪便样本中较低。L. sakei数量在第2次术后标本中明显下降。术后第1次粪便样本中肠杆菌科的数量明显高于术前样本。与术前相比,术后第1次粪便样本中的肠球菌数量显著升高。术后第2次粪便标本中葡萄球菌数量明显高于术前标本。术后视幻觉组葡萄球菌数量明显高于非视幻觉组,第2次术后粪便样本中术后视幻觉组葡萄球菌数量也明显高于非幻视觉组。视幻觉组的假单胞菌数量明显高于非视幻觉组和术后第2次粪便样本。术后第1次粪便标本中,视幻觉组肠杆菌数量高于非视幻觉组。视幻觉组术后第一次粪便样本中总SCFAs浓度显著低于非视幻觉组。以上差异均具有统计学意义(P<0.05)。结论心脏手术后视幻觉的发生与肠道菌群变化存在一定联系,表现为肠道内肠杆菌科和肠球菌属数量增多,乳杆菌数量降低,同时还伴随着SCFAs浓度的降低。     

Quantitative and metabolic changes of hepatic collagens in rats after carbon tetrachloride poisoning

1. The collagen hydroxyproline in rat liver was composed of 3.5% neutral-soluble collagen, 4.9% acid-soluble collagen and 91.6% insoluble collagen. In labelling studies with [(14)C]proline in vitro, the specific radioactivities of neutral-soluble, acid-soluble and insoluble collagens in rat liver were found to be 233000, 69000 and 830d.p.m./mumol of hydroxyproline respectively after 1h. 2. During subacute carbon tetrachloride poisoning the hepatic content of insoluble collagen markedly increased, whereas those of soluble collagens did not change. During recovery from subacute poisoning hepatic contents of soluble collagens were markedly decreased. 3. After 8 weeks of carbon tetrachloride poisoning the specific radioactivities of hepatic soluble collagens increased, while that of insoluble collagen decreased. During recovery from subacute poisoning, the specific radioactivities of soluble collagens decreased to the normal range and that of insoluble collagen further decreased. 4. Hepatic collagenolytic activity solubilizing insoluble collagen, which differs from mammalian collagenase, decreased under the conditions of the subacute poisoning and also during recovery from subacute poisoning.     

In vivo assessment of changes in air and tissue volumes after pneumonectomy

Takeda, S., E. Y. Wu, R. H. Epstein, A. S. Estrera, and C. C. W. Hsia. In vivo assessment of changes in air and tissue volumes after pneumonectomy. J. Appl.Physiol. 82(4): 1340-1348, 1997.We examined theprogression and topographical distribution of postpneumonectomy volumechanges in immature foxhounds undergoing right pneumonectomy (R-Pnx,n = 5) or sham pneumonectomy (Sham, n = 6) at 2 mo of age and subsequentlyraised to maturity. Volumes of lung air (Vair) and tissue(Vti) were estimated by computerized tomography (CT) scan at 7, 22, and52 wk after surgery at a transpulmonary pressure of 20 cmH₂O. Estimates of Vti by CT scanincluded both septal tissue as well as nonseptal tissue (small- andmedium-sized airways and blood vessels); these were compared withestimates of septal Vti by an acetylene rebreathing (Rb) method. Wefound significant correlations between these techniques(Vair_CT = 0.83 Vair_Rb + 275, R = 0.97;Vti_CT = 1.62 Vti_Rb  30, R = 0.81). Extravascular septal Vtireturned to normal 7 wk after R-Pnx and remained normal up to maturity.Nonseptal Vti remained significantly below normal. The greatestincrease in Vti occurred in the midlung region just cephalad and caudalto the heart. After an early period of accelerated tissue growth afterR-Pnx, the rate of septal tissue growth matched that of somatic growth,whereas nonseptal tissue growth lagged behind. Compensatory growth ofthe remaining left lung was not associated with selectivealterations in thoracic development.