New radiofrequency ablation procedure for selective reduction in complicated monochorionic twin or triplet pregnancy using multistep, incremental expansion technique

OBJECTIVE

Radiofrequency ablation (RFA) is the preferred approach for selective reduction in complex monochorionic (MC) multiple pregnancies owing to the ease of operation and minimal invasiveness. To optimize the RFA technique and reduce the risk of adverse pregnancy outcome resulting from the heat-sink effect of RFA therapy, we used an innovative RFA method, in which an electrode needle was expanded incrementally and stepwise. This study aimed to assess the efficacy and safety profile of this novel multistep incremental expansion RFA method for selective fetal reduction in MC twin and triplet pregnancies.

METHODS

This was a single-center retrospective cohort study of all MC multiple pregnancies undergoing RFA between March 2016 and October 2022 at our center. The multistep RFA technique involved the use of an expandable needle, which was gradually expanded during the RFA procedure until cessation of umbilical cord blood flow was achieved. The needle used for the single-step RFA method was fully extended from the start of treatment.

RESULTS

In total, 132 MC multiple pregnancies underwent selective reduction using RFA, including 50 cases undergoing multistep RFA and 82 cases undergoing single-step RFA. The overall survival rates were not significantly different between the multistep and single-step RFA groups (81.1% vs 72.3%; P = 0.234). Similarly, the rates of preterm prelabor rupture of the membranes within 2 weeks after RFA, procedure-related complications, spontaneous preterm delivery and pathological findings on cranial ultrasound, as well as gestational age at delivery and birth weight, did not differ between the two groups. However, there was a trend towards a prolonged procedure-to-delivery interval following multistep RFA compared with single-step RFA (median, 109 vs 99 days; P = 0.377). Moreover, the fetal loss rate within 2 weeks after RFA in the multistep RFA group was significantly lower than that in the single-step RFA group (10.0% vs 24.4%; P = 0.041). The median ablation time was shorter (5.3 vs 7.8 min; P < 0.001) and the median ablation energy was lower (10.2 vs 18.0 kJ; P < 0.001) in multistep compared with single-step RFA. There were no significant differences in neonatal outcomes following multistep vs single-step RFA.

CONCLUSIONS

Overall survival rates were similar between the two RFA methods. However, the multistep RFA technique was associated with a lower risk of fetal loss within 2 weeks after RFA. The multistep RFA technique required significantly less ablation energy and a shorter ablation time compared with single-step RFA in selective fetal reduction of MC twin and triplet pregnancies. Additionally, there was a trend towards a prolonged procedure-to-delivery interval with the multistep RFA technique. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Structural performance of detachable precast concrete column-column joint

A novel type of detachable precast concrete column-column joint (DPC) is proposed in this study to solve the problems in current column-column dry connections including complex load path, uncertainty of structural stiffness of beam-column joints and inconvenience for disassembly. The dry connection technology is applied by composing of steel plate and concrete. Finite element models of DPC were created to study its structural performance including hysteresis curve, skeleton curve, ductility, and energy dissipation capacity. The benchmark models are firstly established and validated against the test data and after that a small-scale parametric study is prepared. The effect of axial pressure ratio and eccentricity distance size on the seismic performance of DPC was studied. Results indict that the optimal value of axial pressure ratio ranges from 0.5 to 0.7. With increase of the axial pressure ratio, the ductility coefficient shows a decreasing trend in general. The eccentricity has little effect on the energy dissipation capacity of the joint.

The Effects of Different Exercise Interventions on Patients with Subjective Cognitive Decline: A Systematic Review and Network Meta-Analysis

BACKGROUND AND OBJECTIVE

Exercise is a promising non-pharmacological therapy for subjective cognitive decline, but it is unclear which type of exercise is most effective. The objective was to assess the comparative effects and ranks of all exercise-based interventions on cognitive function in patients with subjective cognitive decline (SCD).

METHOD

In this network meta-analysis, Online databases for Web of Science, PubMed, Embase, Medline, Cochrane Library and PsycINFO were searched from inception to April 30, 2023. The included studies are randomized controlled trials assessing the efficacy of exercise interventions for individuals with SCD. The primary outcome measure is memory, while secondary outcome measures encompass executive function, attention, verbal fluency, and global cognitive function. Represented using Standardized Mean Differences (SMDs) along with their 95% Confidence Intervals (CIs). Bias assessment was conducted in accordance with the 'Cochrane Risk of Bias Assessment Tool, 2nd Edition' (RoB 2). Pairwise meta-analysis was carried out using the 'meta-analysis' module within STATA 14.0, and network meta-analysis was performed using the 'mvmeta' and 'network' packages available in STATA 14.0. Registration number CRD42023289687.

RESULT

This study included a total of 11 randomized controlled trials, encompassing 1,166 patients. Mind-body exercise was found to be efficacious in enhancing or sustaining memory (SMD: 0.58, 95%CI: 0.06 ~ 1.10) and executive function (SMD: 0.41, 95%CI: 0.09 ~ 0.73) in individuals with subjective cognitive decline. Furthermore, mind-body exercise exhibited the highest probability of being the most effective measures for improving or preventing the decline in memory (surface under cumulative ranking curve (SUCRA) value: 90.4) and executive function (SUCRA value: 91.8). The second-ranked moderate-intensity aerobic exercise has also shown a positive effect on the improvement of executive function in patients with subjective cognitive decline (SMD: 0.23, 95%CI: 0.03 ~ 0.43, SUCRA value: 68.2). However, we did not observe a significant effectiveness of exercise interventions on verbal fluency, attention, and overall cognitive function in subjective cognitive decline.

CONCLUSION

Mind-body exercise may potentially be the optimal strategies for enhancing memory and executive function in individuals with subjective cognitive decline. Additionally, moderate-intensity aerobic exercise has shown a modest positive effect on executive function in subjective cognitive decline. When resources permit, practical application of these findings may be considered. Nevertheless, further support for the conclusions of this study is warranted through larger sample sizes and well-designed multicenter trials.

Greater wax moth control in apiaries can be improved by combining Bacillus thuringiensis and entrapments

The greater wax moth (GWM), Galleria mellonella (Lepidoptera: Pyralidae), is a major bee pest that causes significant damage to beehives and results in economic losses. Bacillus thuringiensis (Bt) appears as a potential sustainable solution to control this pest. Here, we develop a novel Bt strain (designated BiotGm) that exhibits insecticidal activity against GWM larvae with a LC50 value lower than 2 μg/g, and low toxicity levels to honey bee with a LC50 = 20598.78 μg/mL for larvae and no observed adverse effect concentration = 100 μg/mL for adults. We design an entrapment method consisting of a lure for GWM larvae, BiotGm, and a trapping device that prevents bees from contacting the lure. We find that this method reduces the population of GWM larvae in both laboratory and field trials. Overall, these results provide a promising direction for the application of Bt-based biological control of GWM in beehives, although further optimization remain necessary.

Effect of pulmonary function on bone mineral density in the United States: results from the NHANES 2007-2010 study

The relationship between pulmonary function (PF) and bone mineral density (BMD) remains controversial. In the US population, we found a positive association between PF and BMD. Mixed variables such as age, gender, and race may influence this association.

INTRODUCTION

Based on the data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2010, this study explored whether there is a correlation between PF (1st second forceful expiratory volume as a percentage of expected value (FEV1(% predicted)), (one-second rate (FEV1/FVC)), and bone mineral density.

METHODS

We evaluated the relationship between PF and BMD in 6327 NHANES subjects (mean age 44.51 ± 15.64 years) from 2007 to 2010. The bone mineral density of the whole femur was measured by dual-energy X-ray absorptiometry (DXA). After adjusting for a wide range of confounders, we examined the relationship between PF and total femur BMD using a multiple linear regression model.

RESULTS

Correction of race, age, alcohol consumption, body mass index (BMI), height, poor income ratio (PIR), total protein, serum calcium, serum uric acid, cholesterol, serum phosphorus, blood urea nitrogen, FEV1(% predicted), and femur BMD were positively correlated (β = 0.032, 95% CI: 0.010-0.054, P = 0.004). FEV1/FVC was positively correlated with spine BMD (β = 0.275 95%CI: 0.102-0.448, P = 0.002).

CONCLUSIONS

Our study shows that PF is positively associated with BMD in the US population. A variety of factors such as race and age influence this relationship. the relationship between PF and BMD needs to be further investigated, including specific regulatory mechanisms and confounding factors.

[Analysis of treatment costs for pneumoconiosis patients in Hunan Province]

Objective: To explore the level and influencing factors of treatment costs for patients with pneumoconiosis, and to provide a basis for reducing the economic burden of patients with pneumoconiosis and optimizing the rational allocation of medical resources. Methods: In August 2020, the multi-stage stratified sampling method was used to obtain the treatment cost information of pneumoconiosis patients from January to December 2018 in 1123 sample medical institutions. The average cost per time of 2178 outpatients and 7425 inpatients was described, and the differences in the distribution of hospitalization costs for patients with pneumoconiosis were compared by one-way analysis of variance, and a multiple linear regression model was constructed to analyze the influencing factors of hospitalization costs for patients with pneumoconiosis. Results: The average cost of outpatients with pneumoconiosis was 465.88 yuan, and the average cost of inpatients was 12280.63 yuan. There were statistically significant differences in hospitalization expenses among different age, institution level, institution type, length of hospital stay and type of insured (F=10.49, 402.92, 416.35, 2390.48, 1298.14, P<0.001) . Age, length of hospital stay, reimbursement ratio, and institution level were influencing factors of the total hospitalization expenses of patients with pneumoconiosis (t=5.27, 62.20, 22.35, 21.20, P<0.001) . Conclusion: Patients with pneumoconiosis have a heavy burden of treatment costs. Age, length of hospital stay, institution level and reimbursement ratio are the main influencing factors of hospitalization costs. It is recommended to strengthen the prevention and treatment of key populations, standardize the use of medical insurance, and promote the rational allocation of medical resource to reduce the cost burden of pneumoconiosis patients.

The JAK2V617F-bearing vascular niche promotes clonal expansion in myeloproliferative neoplasms

The acquired kinase mutation JAK2V617F plays a central role in myeloproliferative neoplasms (MPNs). However, the mechanisms responsible for the malignant hematopoietic stem/progenitor cell (HSPC) expansion seen in patients with MPNs are not fully understood, limiting the effectiveness of current treatment. Endothelial cells (ECs) are an essential component of the hematopoietic niche, and they have been shown to express the JAK2V617F mutation in patients with MPNs. We show that the JAK2V617F-bearing vascular niche promotes the expansion of the JAK2V617F HSPCs in preference to JAK2WT HSPCs, potentially contributing to poor donor cell engraftment and disease relapse following stem cell transplantation. The expression of Chemokine (C-X-C motif) ligand 12 (CXCL12) and stem cell factor (SCF) were upregulated in JAK2V617F-bearing ECs compared to wild-type ECs, potentially accounting for this observation. We further identify that the thrombopoietin (TPO)/MPL signaling pathway is critical for the altered vascular niche function. A better understanding of how the vascular niche contributes to HSPC expansion and MPN development is essential for the design of more effective therapeutic strategies for patients with MPNs.

Clostridium difficile-associated clinical burden from lack of diagnostic testing in a Chinese tertiary hospital

Despite Clostridium difficile infection (CDI) being a common cause of diarrhoea in hospitals worldwide, diagnostic testing or management guidelines are not available in most hospitals in China. In this prospective two-year study, the incidence of CDI among 276 patients with watery diarrhoea was 23.1%. Lack of diagnostic testing for CDI was associated with improper management in 26.4% of patients, risk of nosocomial transmission from lack of isolation precautions, and risk of community transmission from discharging symptomatic toxigenic C. difficile carriers. Updating practice guidelines in line with the current evidence and implementing diagnostic testing for CDI are recommended in hospitals in China.

JAK2V617F-mutant megakaryocytes contribute to hematopoietic stem/progenitor cell expansion in a model of murine myeloproliferation

The myeloproliferative neoplasms (MPNs) are characterized by hematopoietic stem/progenitor cell (HSPC) expansion and overproduction of mature blood cells. The JAK2^V617F mutation is present in hematopoietic cells in a majority of patients with MPNs, but the mechanism(s) responsible for MPN stem cell expansion remain incomplete. One hallmark feature of the marrow in patients with MPNs is megakaryocyte (MK) hyperplasia. We report here that mice bearing a human JAK2^V617F gene restricted exclusively to the MK lineage develop many of the features of a MPN. Specifically, these mice exhibit thrombocytosis, splenomegaly, increased numbers of marrow and splenic hematopoietic progenitors and a substantial expansion of HSPCs. In addition, wild-type mice transplanted with cells from JAK2^V617F-bearing MK marrow develop a myeloproliferative syndrome with thrombocytosis and erythrocytosis as well as pan-hematopoietic progenitor and stem cell expansion. As marrow histology in this murine model of myeloproliferation reveals a preferentially perivascular localization of JAK2^V617F-mutant MKs and an increased marrow sinusoid vascular density, it adds to accumulating data that MKs are an important component of the marrow HSPC niche, and that MK expansion might indirectly contribute to the critical role of the thrombopoietin/c-Mpl signaling pathway in HSPC maintenance and expansion.

Complete mitochondrial genome of Drabescoides nuchalis (Hemiptera: Cicadellidae)

The complete mitochondrial genome (mitogenome) of Drabescoides nuchalis (Hemiptera: Cicadellidae) was sequenced. It is 15 309 bp in length with 75.62% (A + T) content and comprises 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNA genes, and a non-coding region (GenBank accession no. KR349344). Gene order is identical to that of the inferred ancestral insect genome. All PCGs start with an ATN codon and terminate with TAA except ND4, which has an incomplete stop codon (T). The anticodons are identical to those of Drosophila yakuba. The phylogenetic tree confirms D. nuchalis and two Cicadellidae species are clustered into a clade, and Cicadellidae is a monophyletic group and provides support for the sister relationship of leafhopper and treehopper.

Out-of-focus background subtraction for fast structured illumination super-resolution microscopy of optically thick samples

We propose a structured illumination microscopy method to combine super resolution and optical sectioning in three-dimensional (3D) samples that allows the use of two-dimensional (2D) data processing. Indeed, obtaining super-resolution images of thick samples is a difficult task if low spatial frequencies are present in the in-focus section of the sample, as these frequencies have to be distinguished from the out-of-focus background. A rigorous treatment would require a 3D reconstruction of the whole sample using a 3D point spread function and a 3D stack of structured illumination data. The number of raw images required, 15 per optical section in this case, limits the rate at which high-resolution images can be obtained. We show that by a succession of two different treatments of structured illumination data we can estimate the contrast of the illumination pattern and remove the out-of-focus content from the raw images. After this cleaning step, we can obtain super-resolution images of optical sections in thick samples using a two-beam harmonic illumination pattern and a limited number of raw images. This two-step processing makes it possible to obtain super resolved optical sections in thick samples as fast as if the sample was two-dimensional.

Infrequent Manifestations of Kabuki Syndrome in a Patient with Novel MLL2 Mutation

We present a case of a 9-month-old Hispanic female with Kabuki syndrome with some infrequent manifestations including a single umbilical artery, butterfly vertebrae, a small larynx, a preauricular pit, microtia with internal ear abnormalities, abnormal calcium metabolism, premature thelarche, neonatal/persistent hypoglycemia and eventration of the diaphragm. She was found to have a previously unreported nonsense MLL2 mutation. This is the first case that includes all such findings occurring simultaneously that was genotyped.

Expression analysis of genes putatively involved in chicken gonadal development

In mammals, testis development is initiated by the expression of the sex-determining gene, SRY whereas the genetic trigger for sex determination in birds remains unknown. In the present study, the expression of seven genes implicated in vertebrate sex determination and differentiation were studied in chicken embryonic gonads from day 4 to day 12 of incubation using reverse transcription and the polymerase chain reaction (RT-PCR). Results showed transcription of cLhx9, cGATA4, cVnnl, cPptl, cBrd3 were sexually dimorphic during chicken gonadal development, whereas cEki2, cFog2 were expressed at similar levels in both sexes. Results of comparative studies between mammals and chickens show that vertebrate sex-determining pathways comprise both conserved and divergent elements: expression profiles of cGATA4/cFog2 and cVnnl are similar to those in mammals, while others appear some differences. Possible functions of these genes on chicken gonadal development were analyzed based on their expression profiles.

The lactose repressor system: paradigms for regulation, allosteric behavior and protein folding

In 1961, Jacob and Monod proposed the operon model for gene regulation based on metabolism of lactose in Escherichia coli. This proposal was followed by an explication of allosteric behavior by Monod and colleagues. The operon model rationally depicted how genetic mechanisms can control metabolic events in response to environmental stimuli via coordinated transcription of a set of genes with related function (e.g. metabolism of lactose). The allosteric response found in the lactose repressor and many other proteins has been extended to a variety of cellular signaling pathways in all organisms. These two models have shaped our view of modern molecular biology and captivated the attention of a surprisingly broad range of scientists. More recently, the lactose repressor monomer was used as a model system for experimental and theoretical explorations of protein folding mechanisms. Thus, the lac system continues to advance our molecular understanding of genetic control and the relationship between sequence, structure and function.

Multiple cytokines in human tear specimens in seasonal and chronic allergic eye disease and in conjunctival fibroblast cultures

BACKGROUND

Several cytokines are involved in the recruitment and activation of inflammatory cells in ocular allergic diseases. The purpose of the study was to assay multiple cytokines and chemokines in tears, to compare subgroups of allergic conjunctivitis (AC) with controls, and in culture supernatants to determine whether conjunctival fibroblasts produce some of these cytokines.

METHODS

Fifty to one hundred microlitre tears were obtained from patients with active seasonal allergic conjunctivitis (SAC; n=12), vernal keratoconjunctivitis (VKC; n=18), atopic keratoconjunctivitis (AKC; n=6) and non-atopic controls (n=14). Primary conjunctival fibroblasts grown in vitro were stimulated with IL-4, IL-13 or TNF-alpha for 24 h. Cell-free tear and culture supernatants were assayed for IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, IFN-gamma, TNF-alpha, eotaxin, MCP-1 and RANTES using multiplex bead analysis. Induction of chemokine gene expression was determined by PCR.

RESULTS

IL-1beta, IL-2, IL-5, IL-6, IL-12, IL-13, MCP-1 were increased in all tears groups compared with controls, with highly significant correlations between many of these molecules. In addition IL-4, IFN-gamma, and IL-10 were elevated in SAC and VKC, while eotaxin and TNF-alpha were only increased in VKC. IL-6, IL-8, MCP-1, RANTES and eotaxin were detected from fibroblasts cultures, and were all up-regulated by TNF-alpha. By PCR, fibroblasts expressed MCP-1 transcripts constitutively, whereas IP-10 and Mig were up-regulated by TNF-alpha.

CONCLUSIONS

Differential cytokine levels support tears as a useful indicator of immune mechanisms occurring during AC. The striking similarities in chemokine profiles between tears and fibroblasts suggest these cells as likely sources of chemokines in tears.

11C-Methionine PET to predict survival of glioma patients treated by radiotherapy

1523

Background: The early prediction of glioma prognosis is very important. Amino acid metabolism of glioma is associated with numerous catabolic processes favoring tumor growth. As an essential amino acid, L-methionine plays a central role in the altered metabolism of cancer cells. The aim of this study was to evaluate the prognostic value of PET imaging using 11C-methionine (MET) in patients with gliomas treated by radiotherapy. Methods: MET PET was prospectively performed in 36 patients with gliomas before and within one month after radiotherapy. Tumor MET uptake was measured with the semiquantitative tumor-to-nontumor ratio (T/N ratio). The MET uptake in the tumor and relevant clinical parameters were entered into univariate and multivariate survival analysis. Results: All tumors were identified in the baseline MET PET study. Patients with a baseline T/N ratio of < 4.0 had a significant better survival than patients with a baseline T/N ratio > 4.0 (2-year survival rate: 50.8% versus 0%, P=0.026). Patients with a post radiotherapy ratio of <4.0 had a better survival than that with a post radiotherapy ratio > 4.0 (2-year survival rate: 50.4% versus 0%, P=0.0012). The univariate analysis showed that both baseline and postradiotherapy T/N ratio were statistically significant predictors of patient survival, and postradiotherapy T/N ratio was a significant independent survival predictor in multivariate analysis. Tumors with larger T/N ratio had a significantly poorer prognosis. Conclusions: Baseline MET uptake was a potential survival indicator and postradiotherapy MET uptake was a significant independent predicator in glioma patients treated by radiotherapy. MET PET is a valuable tool in the predication of survival in patients with gliomas treated by radiotherapy.

No significant financial relationships to disclose.

Analytical solutions of contaminant transport from finite one-, two-, and three-dimensional sources in a finite-thickness aquifer

Analytical study of contaminant transport from a finite source in a finite-thickness aquifer is most useful in hydrological and environmental sciences and engineering but rarely investigated in previous studies. This paper provides analytical solutions of contaminant transport from one-, two-, and three-dimensional finite sources in a finite-thickness aquifer using Green's function method. A library of unpublished analytical solutions with different finite source geometry is provided. A graphically integrated MATLAB script is developed to calculate the temporal integrations in the analytical solutions and obtain the final solutions of concentration. The analytical solutions are examined by reproducing the solutions of some special cases discussed in previous studies. The sensitivities of the line source solutions to source geometry, dispersion coefficients, and distance to the source are tested. The contaminant concentration in the near field is found to be sensitive to the source geometry and anisotropy of the dispersion coefficients. The contaminant concentration in the far field is found to be much less sensitive to the source geometry. The physical insights of the analytical solutions are interpreted.

[Effects of repeated high +Gz exposure on several enzyme activities in cardiomyocytes in rats and some protective measures]

Objective. To determine the changes of several myocardial enzymes in rats after repeated high +Gz exposure and the protective effects of preconditioning of low-G exposure and tea polyphenols (TP). Method. Thirty-two male Wistar rats were randomly divided into 4 groups (n = 8 each): control group (group A), +10 Gz group (group B), low-G preconditioning group (group C) and TP protection group (group D). Group B, C and D were exposed to repeated +10 Gz stress (each for 30s, 5 times/d with +1 Gz 1 min intervals, 3 d/wk, 3 weeks in total), but group A was only submitted to +1 Gz for 5 min. Group C was exposed to +2 Gz for 5 min about 1 h prior to +10 Gz stress. Additionally, TP (200 mg/kg) was given orally to group D about 1 h prior to the +Gz experiment, while distilled water was given to groups A, B and C instead. On the next day after the last centrifuge run, the hearts were taken out immediately for making frozen tissue sections. Enzyme histochemical staining and image analysis were carried out for acid phosphatase (ACP), succinate dehydrogenase (SDH), cytochromeoxidase (Cyt aa3) and adenosine triphosphatase (ATPase). Result. As compared with the control, the activities of ACP and SDH in +10 Gz stressed rats decreased significantly (P<0.05), and there was a declining trend for Cyt aa3. But, low-G preconditioning and TP had protective effects on +10 Gz stress-induced reduction of these enzymatic activities (P<0.05). Conclusion. The results showed that repeated high +Gz exposure could bring about decreases of activities in ACP (the marker enzyme of lysosome) and SDH (the marker enzyme of mitochondrial endomembrane), which indicated a reduction of oxidative metabolism in myocardial tissue; but preconditioning with low-G and natural antioxidant TP had protective effects.

[Establishment and experimental study on mouse model of Chlamydia pneumoniae pneumonitis]

OBJECTIVE

To evaluate mice as experimental animals for Chlamydia pneumoniae (C. Pneumoniae) infection and investigate the pathogenesis of C. pneumoniae pneumonitis.

METHODS

The Icr mice were inoculated with C. pneumoniae, strain CWL-029, by the intranasal or intravenous routes. After a single inoculation, mice were killed on the 1st, 3rd, 7th, 15th, 21th, 28th and 60th day separately. The pathological changes of lung tissue were analyzed.

RESULTS

The Icr mice were shown to be susceptible to C. pneumoniae. Inoculation of mice with C. pneumoniae induced a prolonged course of lung infection, as demonstrated by persistence of lung pathology (60 days). In the intranasal inoculation of mice, the lung pathology was characterized by patchy interstitial pneumonitis with predominately neutrophil leukocyte infiltration in the early(7 days) and lyphocytes infiltration in the later stages(14 days later) of infection. After i.v. inoculation, a similarly interstitial pneumonitis was seen, but it was milder and more patchy, especially in the early stage. C. pneumoniae DNA was detected by polymerase chain reaction(PCR) intermittently in the lung tissue. Inoculated mice developed serum IgG antibody responses.

CONCLUSIONS

The Icr mice were shown to be susceptible to C. pneumoniae and the pulmonary infection was characterized by interstitial pneumonitis, especially in mice of intranasal inoculation.

[The progress on +Gz stress-induced injuries of the cardiac structure and function and their mechanisms]

The heart is the dynamic pump of the circulation. To some extent, high +Gz acceleration exposure can result in injuries on cardiac ultrastructure, metabolism and function. Specifically, repeated +Gz exposures can produce harmful effects on aviators, as reported by French and American researchers. However, the mechanisms of injuries on heart under high +Gz stress have not been studied systematically till now; nor have some protective measures been adopted. In this article, acute and chronic +Gz stress induced injuries on cardiac structure and function in animals and detrimental effects on the hearts of pilots are reviewed. Moreover, the related mechanisms are also explained basing on stress injury, oxidative stress and genetic regulation.

Peptidases play an important role in cataractogenesis: an immunohistochemical study on lenses derived from Shumiya cataract rats

The role of proteolytic enzymes in Shumiya cataract rats in alterations to lens proteins during cataract formation was studied immunohistochemically using antibodies against exopeptidases, such as lysosomal dipeptidyl peptidase II (DPP II), cytosolic dipeptidyl peptidase III, and soluble and membrane-bound alanyl aminopeptidases, and against cytosolic endopeptidases such as mu- and m-calpains, and 20S proteasome. AlphaB-crystallin was detected as a proteolytic marker in the lenses. A constant immunoreactivity against all the antibodies employed was observed in the lens epithelium independent of the strain and age of the rats. A weak immunoreactivity against exo- and endopeptidases and an intense reactivity against alphaB-crystallin were observed in the lens fibres of control rats at all ages. The immunoreactivity of these peptidases in lens fibres increased with age in cataract rats, but that of alphaB-crystallin decreased. No reactivity against exo- and endopeptidases was seen in the perinuclear region of lenses of control rats at all ages or in Shumiya cataract rats at 8 and 10 weeks of age, but an intense reactivity against these peptidases was observed in the lens perinuclear region of lenses in cataract rats at 12 and 14 weeks of age. AlphaB-crystallin immunoreactivity was observed with ordered striations in the lens perinuclear region of all control rats whereas the striations in this area of cataract rat lens were disorganized. Membrane-bound alanyl aminopeptidase was detected feebly in the lens epithelium and fibres of both types of rat at all weeks of age. These findings indicate that exo- and endopeptidases, except for membrane-bound alanyl aminopeptidase, are expressed intensively and are age-dependent. Conversely, the amount of alphaB-crystallin decreased with age in lens fibres of cataract rats. Calpains (mu- and m-), 20S proteasome, dipeptidyl peptidases II and III and soluble alanyl aminopeptidase are thought to induce lens opacification kinetically during cataract formation in Shumiya cataract rats through the intracellular turnover of lens proteins.