A Convenient and Effective Preoxygenation Technique for Prolonging Deep Inspiration Breath-Hold Duration With a Venturi Mask With a 50% Oxygen Concentration

PURPOSE

Voluntary deep inspiration breath-hold (DIBH) is commonly used in radiation therapy (RT), but the short duration of a single breath-hold, estimated to be around 20 to 40 seconds, is a limitation. This prospective study aimed to assess the feasibility and safety of using a simple preoxygenation technique with a Venturi mask to prolong voluntary DIBH.

METHODS AND MATERIALS

The study included 33 healthy volunteers and 21 RT patients. Preoxygenation was performed using a Venturi mask with a 50% oxygen concentration. Paired t tests compared the duration of a single DIBH in room air and after 5, 15, and 30 minutes of preoxygenation in healthy volunteers. Sustainability of breath-hold and tolerability of heart rate and blood pressure were assessed for multiple DIBH durations in both volunteers and patients.

RESULTS

In healthy volunteers, a 15-minute preoxygenation significantly prolonged the duration of a single DIBH by 24.95 seconds compared with 5-minute preoxygenation (89 ± 27.76 vs 113.95 ± 30.63 seconds; P < .001); although there was a statistically significant increase in DIBH duration after 30-minute preoxygenation, it was only extended by 4.95 seconds compared with 15-minute preoxygenation (113.95 ± 30.63 vs 118.9 ± 29.77 seconds; P < .01). After 15-minute preoxygenation, a single DIBH lasted over 100 seconds in healthy volunteers and over 80 seconds in RT patients, with no significant differences among 6 consecutive cycles of DIBH. Furthermore, there were no significant differences in heart rate or blood pressure after DIBHs, including DIBH in room air and 6 consecutive DIBHs after 15-minute preoxygenation (all P > .05).

CONCLUSIONS

Preoxygenation with a 50% oxygen concentration for 15 minutes effectively prolongs the duration of 6 cycles of DIBH both in healthy volunteers and RT patients. The utilization of a Venturi mask to deliver 50% oxygen concentration provides a solution characterized by its convenience, good tolerability, and effectiveness.

[Clinical analysis of 10 cases of multi-center tumor necrosis factor receptor-associated periodic syndrome]

Objective: To summarize the clinical characteristics of tumour necrosis factor receptor-associated periodic syndrome (TRAPS) in children. Methods: The clinical manifestations, laboratory tests, genetic testing and follow-up of 10 children with TRAPS from May 2011 to May 2021 in 6 hospitals in China were retrospectively analyzed. Results: Among the 10 patients with TRAPS, including 8 boys and 2 girls. The age of onset was 2 (1, 5) years, the age of diagnosis was (8±4) years, and the time from onset to diagnosis was 3 (1, 7) years. A total of 7 types of TNFRSF1A gene variants were detected, including 5 paternal variations, 1 maternal variation and 4 de novo variations. Six children had a family history of related diseases. Clinical manifestations included recurrent fever in 10 cases, rash in 4 cases, abdominal pain in 6 cases, joint involvement in 6 cases, periorbital edema in 1 case, and myalgia in 4 cases. Two patients had hematological system involvement. The erythrocyte sedimentation rate and C-reactive protein were significantly increased in 10 cases. All patients were negative for autoantibodies. In the course of treatment, 5 cases were treated with glucocorticoids, 7 cases with immunosuppressants, and 7 cases with biological agents. Conclusions: TRAPS is clinically characterized by recurrent fever accompanied by joint, gastrointestinal, skin, and muscle involvement. Inflammatory markers are elevated, and autoantibodies are mostly negative. Treatment mainly involves glucocorticoids, immunosuppressants, and biological agents.

FBW7 upregulation enhances cisplatin cytotoxicity in non- small cell lung cancer cells

INTRODUCTION

Lung cancer is extremely harmful to human health and has one of the highest worldwide incidences of all malignant tumors. Approximately 80% of lung cancers are classified as non-small cell lung cancers (NSCLCs). Cisplatin-based multidrug chemotherapy regimen is standard for such lesions, but drug resistance is an increasing problem. F-box/WD repeat-containing protein 7 (FBW7) is a member of the F-box protein family that regulates cell cycle progression, and cell growth and differentiation. FBW7 also functions as a tumor suppressor.

METHODS

We used cell viability assays, Western blotting, and immunofluorescence combined with siRNA interference or plasmid transfection to investigate the underlying mechanism of cisplatin resistance in NSCLC cells.

RESULTS

We found that FBW7 upregulation significantly increased cisplatin chemosensitivity and that cells expressing low levels of FBW7, such as NCI-H1299 cells, have a mesenchymal phenotype. Furthermore, siRNA-mediated silencing or plasmid-mediated upregulation of FBW7 resulted in altered epithelial-mesenchymal transition (EMT) patterns in NSCLC cells. These data support a role for FBW7 in regulating the EMT in NSCLC cells.

CONCLUSION

FBW7 is a potential drug target for combating drug resistance and regulating the EMT in NSCLC cells.

The number of CD8+ T cells and NKT cells increases in the aqueous humor of patients with Behçet's uveitis

To determine whether there are differences in the immunopathogenesis of different endogenous uveitis syndromes, the phenotypic characteristics of immune cells were analysed among patients with endogenous uveitis. The aetiology of the uveitis included idiopathic recurrent acute anterior uveitis (18 patients), idiopathic intermediate uveitis (13 patients), Behçet's uveitis (17 patients), Vogt-Koyanagi-Harada syndrome (7 patients), and so on. Flow cytometric analysis was performed using immune cells of the aqueous humor and the peripheral blood during the active phase of intraocular inflammation, and monoclonal antibodies to CD3, CD4, CD8, CD14, CD19, CD56, TCR gammadelta, pan TCR alphabeta and Valpha24. CD8+ T cells were predominant in the aqueous humor of the patients with Behçet's uveitis, whereas CD4+ T cells were mainly found in the aqueous humor of patients other than those with Behçet's uveitis. The number of NKT (CD3+CD56+) cells was significantly higher both in the aqueous humor and the peripheral blood of the patients with Behçet's uveitis compared with the other groups (P < 0.05). CD8+CD56+ cells were the predominant subtype of the increased NKT cells in patients with Behçet's uveitis. In addition, intraocular infiltration of CD14+ cells significantly differed among the uveitis patients (P < 0.05). These results suggest that the immunopathogenesis of endogenous uveitis can vary between syndromes, and that CD8+CD56+ NKT cells may play an important role in the immunopathogenesis of Behçet's uveitis.

Acidogenesis of dairy wastewater at various pH levels

Continuous experiments were conducted to study the influence of pH in the range 4.0-6.5 on the acidification of dairy wastewater at 37 degrees C with 12 hours of hydraulic retention in an upflow reactor. Results showed that degradation of dairy pollutants increased with pH from pH 4.0 to 5.5. At pH 5.5, 95% of carbohydrate, 82% of protein and 41% of lipid were degraded. Based on chemical oxygen demand (COD), 48.4% of dairy pollutants were converted into volatile fatty acids and alcohols in the mixed liquor, 6.1% into hydrogen and methane in biogas, and the remaining 4.9% into biomass. The biomass yield at pH 5.5 was estimated as 0.32 mg-VSS/mg-COD. Further increase of pH, up to 6.5, increased degradation of carbohydrate, protein and lipid only slightly, but resulted in the lowering of overall acid and alcohol production due to their increased conversion into methane. Acetate, propionate, butyrate and ethanol are the main products of acidogenesis. Productions of propionate and ethanol were favored at pH 4.0-4.5, whereas productions of acetate and butyrate were favored at pH 6.0-6.5.

Ethacrynic acid inhibits pancreatic exocrine secretion

AIM

The effect of ethacrynic acid on pancreatic exocrine secretion function and potential mechanisms of interference with the secretory process in pancreatic acinar cells were investigated.

METHODS

After incubation with ethacrynic acid for 30 min, caerulein-stimulated amylase release and cholecystokinin (CCK) receptor binding characteristics were assessed in isolated rat pancreatic acini. The level of thiol groups (glutathione and protein thiols) and cytosolic free calcium were measured in pancreatic acinar cells.

RESULTS

Ethacrynic acid decreased caerulein (0.1 nmol/L)-stimulated amylase release and the level of pancreatic acinar glutathione in a concentration-dependent fashion without a marked increase in cell damage. Ethacrynic acid also inhibited the caerulein (1 nmol/L)-induced Ca2+ mobilization in pancreatic acinar cells. But neither protein thiol nor CCK-receptor binding characteristics was altered by ethacrynic acid.

CONCLUSION

Ethacrynic acid inhibit pancreatic exocrine secretion by depletion of glutathione and down-regulation of caerulein-induced Ca2+ mobilization. Glutathione might play a potential role in the secretory process in pancreatic acinar cells and in the secretory blockade observed in acute pancreatitis.

The plant kinetochore

Kinetochores are large protein complexes that bind to centromeres. By interacting with microtubules and their associated motor proteins, kinetochores both generate and regulate chromosome movement. Kinetochores also function in the spindle checkpoint; a surveillance mechanism that ensures that metaphase is complete before anaphase begins. Although the ultrastructure of plant kinetochores has been known for many years, only recently have specific kinetochore proteins been identified. The recent data indicate that plant kinetochores contain homologs of many of the proteins implicated in animal and fungal kinetochore function, and that the plant kinetochore is a redundant structure with distinct biochemical subdomains.

Functional redundancy in the maize meiotic kinetochore

Kinetochores can be thought of as having three major functions in chromosome segregation: (a) moving plateward at prometaphase; (b) participating in spindle checkpoint control; and (c) moving poleward at anaphase. Normally, kinetochores cooperate with opposed sister kinetochores (mitosis, meiosis II) or paired homologous kinetochores (meiosis I) to carry out these functions. Here we exploit three- and four-dimensional light microscopy and the maize meiotic mutant absence of first division 1 (afd1) to investigate the properties of single kinetochores. As an outcome of premature sister kinetochore separation in afd1 meiocytes, all of the chromosomes at meiosis II carry single kinetochores. Approximately 60% of the single kinetochore chromosomes align at the spindle equator during prometaphase/metaphase II, whereas acentric fragments, also generated by afd1, fail to align at the equator. Immunocytochemistry suggests that the plateward movement occurs in part because the single kinetochores separate into half kinetochore units. Single kinetochores stain positive for spindle checkpoint proteins during prometaphase, but lose their staining as tension is applied to the half kinetochores. At anaphase, approximately 6% of the kinetochores develop stable interactions with microtubules (kinetochore fibers) from both spindle poles. Our data indicate that maize meiotic kinetochores are plastic, redundant structures that can carry out each of their major functions in duplicate.

Apoptosis of CD4+ T cells occurs in experimental autoimmune anterior uveitis (EAAU)

To investigate the spontaneous turning off mechanism of endogenous uveitis, EAAU was induced in Lewis rats. Immunohistochemical and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) stains revealed that CD4+ T cells were predominant in the uveal tissue of EAAU and that the apoptosis of these cells had occurred and progressed throughout the inflammatory period in EAAU eyes. The immunohistochemistry and in situ hybridization for Fas ligand (FasL) expression showed that the expression of Fas ligand was increased in the EAAU eyes compared with control eyes. These results suggest that the apoptosis of CD4+ T cells may play a key role in the spontaneous turning off mechanism of intra-ocular inflammation and that the induction of apoptosis may be mediated by the Fas-FasL system in EAAU.

A maize homolog of mammalian CENPC is a constitutive component of the inner kinetochore

Genes for three maize homologs (CenpcA, CenpcB, and CenpcC) of the conserved kinetochore assembly protein known as centromere protein C (CENPC) have been identified. The C-terminal portion of maize CENPC shares similarity with mammalian CENPC and its yeast homolog Mif2p over a 23-amino acid region known as region I. Immunolocalization experiments combined with three-dimensional light microscopy demonstrated that CENPC is a component of the kinetochore throughout interphase, mitosis, and meiosis. It is shown that sister kinetochore separation occurs in two discrete phases during meiosis. A partial separation of sister kinetochores occurs in prometaphase I, and a complete separation occurs in prometaphase II. CENPC is absent on structures known as neocentromeres that, in maize, demonstrate poleward movement but lack other important features of centromeres/kinetochores. CENPC and a previously identified centromeric DNA sequence interact closely but do not strictly colocalize on meiotic chromosomes. These and other data indicate that CENPC occupies an inner domain of the maize kinetochore.

A maize homolog of mammalian CENPC is a constitutive component of the inner kinetochore

Genes for three maize homologs (CenpcA, CenpcB, and CenpcC) of the conserved kinetochore assembly protein known as centromere protein C (CENPC) have been identified. The C-terminal portion of maize CENPC shares similarity with mammalian CENPC and its yeast homolog Mif2p over a 23-amino acid region known as region I. Immunolocalization experiments combined with three-dimensional light microscopy demonstrated that CENPC is a component of the kinetochore throughout interphase, mitosis, and meiosis. It is shown that sister kinetochore separation occurs in two discrete phases during meiosis. A partial separation of sister kinetochores occurs in prometaphase I, and a complete separation occurs in prometaphase II. CENPC is absent on structures known as neocentromeres that, in maize, demonstrate poleward movement but lack other important features of centromeres/kinetochores. CENPC and a previously identified centromeric DNA sequence interact closely but do not strictly colocalize on meiotic chromosomes. These and other data indicate that CENPC occupies an inner domain of the maize kinetochore.

Surgical treatment of subretinal neovascular membrane

The visual results of laser photocoagulation for subfoveal choroidal neovascular membrane (CNVM) has not always been satisfactory. The surgical removal of the neovascular membrane may be another treatment option. To investigate the prognosis and risk factors of this surgery, we analyzed the results of surgical removal of subfoveal CNVM (23 eyes), subfoveal hemorrhage with CNVM (6 eyes), and subfoveal hemorrhage alone (6 eyes). The mean follow-up period was 17.7 months (range 2 to 47 months). The mean preoperative membrane size was 0.89 disc diameter and the mean postoperative retinal pigment epithelial (RPE) defect size was 1.33 disc diameter. Visual improvement was observed in 13 out of the 23 eyes (56.5%) with sufoveal CNVM, four out of the six eyes (66.6%) with subretinal hemorrhage and CNVM, and five out of the six eyes (83.3%) with subretinal hemorrhage only. The visual outcome of subfoveal CNVM surgery was related to the presence of a subfoveal RPE defect (p = 0.005) rather than to the size of the RPE defect. No recurrence of neovascular membrane was observed during the follow up period. In conclusion, surgical removal may be a good alternative treatment for subfoveal CNVM.

The maize homologue of the cell cycle checkpoint protein MAD2 reveals kinetochore substructure and contrasting mitotic and meiotic localization patterns

We have identified a maize homologue of yeast MAD2, an essential component in the spindle checkpoint pathway that ensures metaphase is complete before anaphase begins. Combined immunolocalization of MAD2 and a recently cloned maize CENPC homologue indicates that MAD2 localizes to an outer domain of the prometaphase kinetochore. MAD2 staining was primarily observed on mitotic kinetochores that lacked attached microtubules; i.e., at prometaphase or when the microtubules were depolymerized with oryzalin. In contrast, the loss of MAD2 staining in meiosis was not correlated with initial microtubule attachment but was correlated with a measure of tension: the distance between homologous or sister kinetochores (in meiosis I and II, respectively). Further, the tension-sensitive 3F3/2 phosphoepitope colocalized, and was lost concomitantly, with MAD2 staining at the meiotic kinetochore. The mechanism of spindle assembly (discussed here with respect to maize mitosis and meiosis) is likely to affect the relative contributions of attachment and tension. We support the idea that MAD2 is attachment-sensitive and that tension stabilizes microtubule attachments.

Antiproliferative effect of mitomycin C on experimental proliferative vitreoretinopathy in rabbits

To investigate the therapeutic potential of mitomycin C (MMC) in the management of proliferative vitreoretinopathy (PVR), antiproliferative effect of MMC on rabbit retinal pigment epithelial (RPE) cells, its intraocular toxicity, and its preventive effect on experimental PVR were investigated. Cultured rabbit RPE cells were exposed to various concentrations of MMC ranging from 1.0 x 10(-3) to 1.0 microgram/ml for 72 hours. The RPE cells were then cultured in a medium without MMC for another 7 days, and the cells were harvested and counted. Toxicity of MMC to rabbit retina was evaluated after intravitreal injection of MMC by means of clinical observation, electrophysiologic test, and histopathologic examination. To test antiproliferative effect of MMC on experimental PVR, 200,000 cultured RPE cells were injected into the vitreous cavity of pigmented rabbits, and either 0.2 micrograms or 1.0 micrograms MMC was injected intravitreally 24 hours after RPE cell injection. Two to four weeks later, the vitreoretinal status was compared between MMC-treated eyes and control eyes. The antiproliferative effect of MMC on RPE cells was evident at the concentration of 1.0 x 10(-2) micrograms/ml. The drug concentration required for 50% inhibition of growth was 3 x 10(-2) micrograms/ml. Nontoxic intraocular doses of MMC were 2.0 micrograms in rabbit eyes with normal vitreous and 1.0 microgram in rabbit eyes with gas-compressed vitreous. The rates of traction retinal detachment after intravitreal RPE cell injection were reduced in the eyes treated with MMC compared with control eyes. These results indicate that MMC may have clinical application to the treatment of PVR.

Neocentromere-mediated chromosome movement in maize

Neocentromere activity is a classic example of nonkinetochore chromosome movement. In maize, neocentromeres are induced by a gene or genes on Abnormal chromosome 10 (Ab10) which causes heterochromatic knobs to move poleward at meiotic anaphase. Here we describe experiments that test how neocentromere activity affects the function of linked centromere/kinetochores (kinetochores) and whether neocentromeres and kinetochores are mobilized on the spindle by the same mechanism. Using a newly developed system for observing meiotic chromosome congression and segregation in living maize cells, we show that neocentromeres are active from prometaphase through anaphase. During mid-anaphase, normal chromosomes move on the spindle at an average rate of 0.79 micron/min. The presence of Ab10 does not affect the rate of normal chromosome movement but propels neocentromeres poleward at rates as high as 1.4 micron/min. Kinetochore-mediated chromosome movement is only marginally affected by the activity of a linked neocentromere. Combined in situ hybridization/immunocytochemistry is used to demonstrate that unlike kinetochores, neocentromeres associate laterally with microtubules and that neocentromere movement is correlated with knob size. These data suggest that microtubule depolymerization is not required for neocentromere motility. We argue that neocentromeres are mobilized on microtubules by the activity of minus end-directed motor proteins that interact either directly or indirectly with knob DNA sequences.

The outcome of cryotherapy for retinopathy of prematurity (ROP) according to ROP location

Cryotherapy has been shown to be an effective treatment for retinopathy of prematurity (ROP) stage 3+. However, the outcome of cryotherapy is less favorable in zone 1 ROP than in zone 2 ROP. We suspected whether there may be differences in the outcomes of cryotherapy if the zone of ROP is further divided. So we reviewed the records of 85 premature infants (145 eyes) who had undergone cryotherapy for ROP. The frequencies of favorable outcome were 42.9% of 14 eyes (zone 1), 78.9% of 38 eyes (posterior zone 2), 92.9% of 70 eyes (mid zone 2), and 100.0% of 23 eyes (anterior zone 2), respectively (p < 0.001). These results suggest that the more posteriorly the ROP is located, the less favorable the outcome of cryotherapy.

Change of refraction in premature infants after cryotherapy for retinopathy of prematurity between the age of six months and three years

To investigate the chronological change of refraction in premature infants after cryotherapy for retinopathy of prematurity (ROP), cycloplegic refractions had been performed at 6 months and 3 years after term in premature infants who underwent cryotherapy for ROP. The changes of refractions between the two study ages were evaluated not only in the total cryo-treated eyes, but also in the subdivided groups according to the posterior pole appearances. In the total 61 eyes of 32 premature infants, mean spherical equivalents were -4.05D vs. -5.94D (6 months vs. 3 years) (p = 0.0001). In the normal posterior pole group (48 eyes), mean spherical equivalents were -3.45D vs. -5.68D (6 months vs. 3 years) (p = 0.0000), and in the abnormal posterior pole group (13 eyes), -6.28D vs. -6.86D (6 months vs. 3 years) (p = 0.6496). These results mean that there is a myopic progressive change between 6 months and 3 years after term in the cryo-treated eyes for acute ROP and it is more evident in the eyes with normal posterior pole.

Results of vitreous surgery for posterior complications of chronic uveitis

To determine surgical results and predictive factors of final visual acuity, a total of 30 eyes in 30 uveitis patients who underwent vitreous surgery including pars plana vitrectomy were followed for at least 6 months and various preoperative factors and postoperative results were analyzed. Our surgical indications were vitreous opacity, traction retinal detachment, combined rhegmatogenous-traction detachment. Preoperatively detached retina was finally reattached in 15 (83.3%) of 18 eyes. Final visual acuity improved in 19 (63.3%) of 30 eyes, but decreased in 3 eyes compared with the initial acuity. Cystoid macular edema was the main cause of poor visual acuity after surgery. Eyes with good final visual acuity showed relatively normal electroretinograms before surgery, but the relationship between them was not statistically significant. Duration of postoperative inflammation affected final visual acuity significantly. These results suggest that chronic uveitis patients with vitreoretinal complications can be managed by vitreous surgery with good anatomic and functional results.