Effect of dry eye on the reliability of keratometry for cataract surgery planning

PURPOSE

This study aimed to evaluate the effects of dry eye on the reproducibility of keratometry (K) measurements in patients presenting for cataract surgery.

METHODS

A non-randomized controlled clinical study was performed. Eighty-three eyes of eighty-three patients with cataracts who were enrolled in our hospital from March 2020 to July 2020 were studied. The mean non-invasive tear film break-up time (NIBUT), corneal fluorescein staining score, and ocular surface disease (OSD) SPEED II questionnaire were measured and recorded prior to surgery, and the patients were assigned to a "dry eye" group (n=35) or a "non-dry eye" group (n=48). The K of the patients was measured twice by a Tomey OA-2000 (an average of three times each). The difference of the mean K (ΔKm) and astigmatism vector (ΔKvector) between the two measurements was calculated. The ΔKm and ΔKvector between the two groups were compared. The relationship between the measurement parameters of dry eyes and the accuracy of the preoperative K values was analyzed.

RESULTS

ΔKm was 0.09 D [0.03; 0.19] in the non-dry eye control group and 0.28 D [0.18; 0.50] in the dry eye group, with a statistical difference between the two groups (P=0.005). The ΔKvector of the non-dry eye control group was 0.22 D [0.14; 0.42], and that of the dry eye group was 0.50 D [0.28; 1.06]. There was a significant difference between the two groups (P=0.010). Between the two groups, the percentage of the ΔKm and ΔKvector values greater than 0.5 D were statistically different (P<0.05). There was no significant difference in ΔKm between the groups with NIBUT>5s and NIBUT≤5s (P=0.537). There was no significant difference in ΔKm between groups≥2 and<2 on the OSD SPEED II questionnaire scores (P=0.442).

CONCLUSION

Dry eye can affect the reliability of keratometry measurements before cataract surgery, thereby affecting the accuracy of intraocular lens power calculations. In cataract surgery planning, it is necessary to detect subjective and objective indicators of dry eye in patients and carry out effective intervention so as to avoid refractive errors caused by inaccurate keratometry measurements.

Cataract, glaucoma, and diabetic retinopathy are independent risk factors affecting falls in the older adult with eye diseases

OBJECTIVES

Falls are the leading cause of injury-related hospitalization in older adult, presenting a significant public health concern. To examine the specific eye diseases for risk factors of falls in the older adult.

METHODS

A total of 775 older adults admitted to tertiary care hospitals were divided into a fall or non-fall group based on a questionnaire. Logistic regression analysis was used to identify factors associated with falls.

RESULTS

With 208 falls, 775 participants were recruited. The major associated factors of falls were older age (Odds ratios [OR]: 1.05), female (OR: 1.91), cardiovascular diseases (OR: 1.65), more outdoor activities (OR: 2.81), cataract (OR: 1.65), glaucoma (OR: 1.63), diabetic retinopathy (OR: 2.72).

CONCLUSIONS

Our study demonstrates that cataract, glaucoma, and diabetic retinopathy in the older adult with eye diseases are independent risk factors of falls, which may shed light on the prevention of falls in the older adult with eye diseases.

Lactobacillus coryniformis subsp. torquens inhibits bone loss in obese mice via modification of the gut microbiota

High-fat diet (HFD)-induced obesity results in bone loss associated with an imbalanced gut microbiota and altered immune status. Probiotics are live microorganisms that are beneficial to the host and are important in maintaining bone health and gut homeostasis. In this study, the probiotic Lactobacillus coryniformis subsp. torquens (T3L) was isolated from traditional yak milk cheese produced in Lhasa and showed distinct acid and bile salt resistance as potential probiotics. Our data indicated that T3L not only reversed HFD-induced gut dysbiosis, as indicated by decreased Firmicutes-to-Bacteroidetes ratios but also reduced bone loss. The anti-obesity, microbiome-modulating, and bone-protective effects were transmissible via horizontal faeces transfer from T3L-treated mice to HFD-fed mice. The protective effects of T3L on bone mass were associated with regulatory T (Treg) cell-mediated inhibition of osteoclast differentiation. Our data indicate that T3L is a regulator of the gut microbiota and bone homeostasis in an animal model.

[Autologous stem cell transplantation improves outcomes of patients with multiple myeloma receiving proteasome inhibitors and lenalidomide treatment]

OBJECTIVE

To evaluate the effect of autologous stem cell transplantation (ASCT) on treatment response and survival outcomes in patients with newly diagnosed multiple myeloma (MM) receiving treatments with proteasome inhibitors and lenalidomide.

METHODS

We retrospectively collected the clinical data of newly diagnosed MM patients, who were eligible for ASCT and received proteasome inhibitors or lenalidomide-based treatment in our hospital from January, 2015 to December, 2019. The patients were divided into transplantation group and non-transplantation group, and in transplantation group, the patients received 4 to 6 courses of induction therapy with proteasome inhibitors or lenalidomide before ASCT, while those in the non-transplantation group received more than 8 courses of induction and consolidation therapy with proteasome inhibitors or lenalidomide-based regimens. The therapeutic efficacy and survival outcomes of the patinets were compared between the two groups.

RESULTS

A total of 105 patients were enrolled in the study, including 48 (45.7%) in transplantation group and 57 (54.3%) in non-transplantation group. The two groups were matched for gender, age and treatment response after 4 courses of induction therapy (P > 0.05). The rate of optimal response before relapse differed significantly between the two groups (P=0.000), and the patients receiving ASCT had significantly higher rates of complete response (85.4% vs 54.4%, P= 0.001) and very good partial response or better (95.8% vs 73.7%, P=0.002) than those without ASCT. At the end of follow-up, the median progression-free survival in the transplantation group was not reached, as compared with 29 months in the nontransplantation group (P=0.013). The median overall survival (OS) in the two groups was not reached, but the OS was better in the transplant group than in the non-transplant group (P=0.022).

CONCLUSION

ASCT can further improve the depth of remission and survival outcomes in patients with newly diagnosed MM receiving treatments with proteasome inhibitors and lenalidomide.

Identification of translationally controlled tumor protein in promotion of DNA homologous recombination repair in cancer cells by affinity proteomics

Translationally controlled tumor protein(TCTP) has been implicated in the regulation of apoptosis, DNA repair and drug resistance. However, the underlying molecular mechanisms are poorly defined. To better understand the molecular mechanisms underlying TCTP involved in cellular processes, we performed an affinity purification-based proteomic profiling to identify proteins interacting with TCTP in human cervical cancer HeLa cells. We found that a group of proteins involved in DNA repair are enriched in the potential TCTP interactome. Silencing TCTP by short hairpin RNA in breast carcinoma MCF-7 cells leads to the declined repair efficiency for DNA double-strand breaks on the GFP-Pem1 reporter gene by homologous recombination, the persistent activation and the prolonged retention of γH2AX and Rad51 foci following ionizing radiation. Reciprocal immunoprecipitations indicated that TCTP forms complexes with Rad51 in vivo, and the stability maintenance of Rad51 requires TCTP in MCF-7 cells under normal cell culture conditions. Moreover, inactivation of TCTP by sertraline treatment enhances UVC irradiation-induced apoptosis in MCF-7 cells, and causes sensitization to DNA-damaging drug etoposide and DNA repair inhibitor olaparib. Thus, we have identified an important role of TCTP in promoting DNA double-stand break repair via facilitating DNA homologous recombination processes and highlighted the great potential of TCTP as a drug target to enhance conventional chemotherapy for cancer patients with high levels of TCTP expression.

Correlation between TRAIL and caspase-8 expression and their relationship with cell proliferation and apoptosis in human osteosarcoma

Osteosarcoma is a common malignant bone tumor that mainly affects children and adolescents. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor superfamily. Caspase-8 appears in the upstream of apoptosis signaling pathway among caspases. We investigated TRAIL and caspase-8 levels in osteosarcoma patients to determine their correlation with cell proliferation and apoptosis. Osteosarcoma and osteochondroma patients receiving surgery in our hospital were selected. TRAIL and caspase-8 expression levels in tissue were determined by immunohistochemistry, and protein levels in cells were evaluated by western blotting. Human osteosarcoma cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The osteosarcoma and osteochondroma cell cycles and apoptosis were investigated by flow cytometry. Correlation analysis was applied to TRAIL and caspase-8 levels during cell apoptosis. Positive TRAIL and caspase-8 expression rates in osteosarcoma tissue were significantly lower than in the controls (P < 0.05). TRAIL (0.114 ± 0.002) and caspase-8 (0.352 ± 0.124) levels in experimental cells were obviously lower than in the controls (P < 0.05). Osteosarcoma cells in the experimental group demonstrated higher proliferation and lower apoptosis at 24, 48, and 72 h (P < 0.05). The experimental cell number increased in the G1 stage and decreased in the S stage (P < 0.05). TRAIL and caspase-8 proteins showed positive correlation with apoptosis in osteosarcoma (P < 0.05). Human osteosarcoma presented reduced TRAIL and caspase-8 levels with enhanced cell proliferation and reduced apoptosis. TRAIL and caspase-8 expression levels were positively correlated with apoptosis in osteosarcoma.

The physics for the formation of cell-in-cell structures

The formations of cell-in-cell structures have been found in several important biological processes. Recent studies have shed light on the biochemical signaling pathways as well as the quantitative understandings of the underlying physics. Multiple new features that regulate the cellular engulfment have been identified. However, the driving forces promoting the structural formation are still under debate. This review focuses on the recent progress and discusses the potential significance of the existing physical models.

Reversal of multidrug resistance of gastric cancer cells by down-regulation of ZNRD1 with ZNRD1 siRNA

The over-expression of a new zinc ribbon (ZNRD1) gene has been shown previously to promote a multidrug-resistant phenotype in gastric cancer cells through the up-regulation of permeability-glycoprotein (P-gp). In the present study, siRNA eukaryotic expression vectors of ZNRD1 are constructed and transfected into SGC7901/VCR cells to examine whether or not down-regulation of ZNRD1 increases cell sensitivity towards chemotherapeutic drugs. After transfection, ZNRD1 expression decreased dramatically in ZNRD1 siRNA transfectants compared with that in parental cells and empty vector control cells. Down-regulation of ZNRD1 significantly enhanced the sensitivity of SGC7901/VCR cells to vincristine, adriamycin and etoposide, but not to 5-fluorouracil and cisplatin. Cell capacity to efflux adriamycin decreased markedly in ZNRD1 siRNA transfectants, and correlation between ZNRD1 down-regulation and increased multidrug resistance 1 (MDR1) gene transcriptional activity was observed. These results suggest that the ZNRD1 siRNA constructs down-regulate the expression of ZNRD1 effectively and reverse the resistant phenotype of gastric cancer cells. Furthermore, ZNRD1 might influence transcription of the MDR1 gene and thus play an important role in multidrug resistance in gastric carcinoma.

Growth in neurofibromatosis 1 microdeletion patients

Microdeletions of the entire NF1 gene and surrounding genomic region occur in about 5% of patients with neurofibromatosis 1 (NF1). NF1 microdeletion patients usually have more cutaneous and plexiform neurofibromas and a higher risk of developing malignant peripheral nerve sheath tumors than other people with NF1. Somatic overgrowth has also been observed in NF1 microdeletion patients, an observation that is remarkable because most NF1 patients are smaller than average for age and sex. We studied longitudinal measurements of height, weight, and head circumference in 56 patients with NF1 microdeletions and 226 NF1 patients with other kinds of mutations. Although children with NF1 microdeletions were much taller than non-deletion NF1 patients at all ages after 2 years, the lengths of deletion and nondeletion NF1 patients were similar in early infancy. NF1 microdeletion patients tended to be heavier than other NF1 patients, but height or weight more than 3 standard deviations above the mean for age and sex was infrequent in children with NF1 microdeletions. Head circumference and age of puberty were similar in deletion and non-deletion NF1 patients. The pattern of growth differs substantially in deletion and non-deletion NF1 patients, but the pathogenic basis for this difference is unknown.

High cytoplasmic expression of SALL4 predicts a malignant phenotype and poor prognosis of breast invasive ductal carcinoma

Sal-like 4(SALL4) is significant for maintaining self-renewal and pluripotency in embryonic stem cells, cancer cells and perhaps even cancer stem cells. The expression of SALL4 has been recorded in various kinds of cancers and is deemed to have a clinical value for diagnosis. However, little information on SALL4 expression has been illustrated in breast cancer. In this study, the expression of SALL4 was scrutinized by immunohistochemical analysis in breast invasive ductal carcinoma in a large cohort of 160 patients. High cytoplasmic expression of SALL4 was detected in breast cancer tissues compared with normal adjacent tissues. High SALL4 expression was associated with advanced tumor invasion (p = 0.019), lymph node stage (p = 0.027), ER (p = 0.030), PR (p = 0.037), HER2 (p = 0.019) and TNBC (p = 0.007) in overall patients. Interestingly, in Kaplan-Meier analysis, breast cancer patients with high expression of SALL4 demonstrated a worse OS. Both univariate and multivariate analysis illustrated that examination of SALL4 was of great prognostic value in OS. Thus, our data showed that high cytoplasmic expression of SALL4 was considered to be an independent prognostic indicator for breast invasive ductal carcinoma.

Detection of acute cerebral hemorrhage in rabbits by magnetic induction

Acute cerebral hemorrhage (ACH) is an important clinical problem that is often monitored and studied with expensive devices such as computed tomography, magnetic resonance imaging, and positron emission tomography. These devices are not readily available in economically underdeveloped regions of the world, emergency departments, and emergency zones. We have developed a less expensive tool for non-contact monitoring of ACH. The system measures the magnetic induction phase shift (MIPS) between the electromagnetic signals on two coils. ACH was induced in 6 experimental rabbits and edema was induced in 4 control rabbits by stereotactic methods, and their intracranial pressure and heart rate were monitored for 1 h. Signals were continuously monitored for up to 1 h at an exciting frequency of 10.7 MHz. Autologous blood was administered to the experimental group, and saline to the control group (1 to 3 mL) by injection of 1-mL every 5 min. The results showed a significant increase in MIPS as a function of the injection volume, but the heart rate was stable. In the experimental (ACH) group, there was a statistically significant positive correlation of the intracranial pressure and MIPS. The change of MIPS was greater in the ACH group than in the control group. This high-sensitivity system could detect a 1-mL change in blood volume. The MIPS was significantly related to the intracranial pressure. This observation suggests that the method could be valuable for detecting early warning signs in emergency medicine and critical care units.

Trends of hypertension prevalence, awareness, treatment and control in rural areas of northern China during 1991-2011

This study aims to investigate the trends in prevalence, awareness, treatment and control of hypertension among rural residents aged 35-74 years in northern China during the country's rapid economic development from 1991 to 2011. Two surveys, conducted in 1991 and 2011, included 2196 and 1939 participants aged 35-74 years from same villages in Ji County, Tianjin of China, respectively. The prevalence of hypertension, adjusted by age and gender using the world standard population in 2000, increased 30% (39.9% vs 51.7%) between 1991 and 2011. The increase was greatest (68%) in women aged 35-44 years. Meanwhile, the prevalence of stage II hypertension increased by 75% overall, with a 4-fold increase in men aged 45-54 years. Although the awareness, treatment and control of hypertension increased significantly during the same period, they remained unacceptably poor. In conclusion, the community-based surveys showed that the prevalence of hypertension in rural residents of northern China aged 35-74 years increased rapidly over the past 20 years, and most dramatically in young women. Efforts in the primary prevention of hypertension, particularly for young women, and promoting education for hypertension awareness, treatment and control are of paramount importance in rural China.

Mosaicism in von Hippel-Lindau disease with severe renal manifestations

von Hippel-Lindau (VHL) disease is an inheritable multisystem tumor syndrome characterized by multiple benign and malignant tumors affecting multiple organs. VHL is the result of a germline mutation in the VHL tumor suppressor gene. Molecular genomic analysis routinely confirms the clinical diagnosis. However, the use of molecular diagnostic methods can often be insufficient for the detection of mosaic germline VHL mutations, making the diagnosis of some cases of VHL difficult. Here, we report the case of a VHL mosaic patient with bilateral renal lesions in the absence of other VHL-associated lesions. A VHL mutation was not originally detected by routine molecular testing. Nonetheless, the detection of a heterozygous c.194C>G (p.Ser65Trp) VHL mutation in the patient's daughter prompted further genetic assessment and eventually resulted in the finding of a mosaic c.194C>G (p.Ser65Trp) VHL mutation in the patient. The mutation rate was 18.8 ± 3.84% in peripheral leukocytes. As the frequency of VHL mosaicism remains underdetermined, the possibility of a diagnosis of mosaic VHL should be considered in patients with both typical and atypical VHL-associated manifestations.

YKL-40 protein levels and clinical outcome of human endometrial cancer

The secreted glycoprotein YKL-40 is a member of the chitinase family and elevated serum YKL-40 levels have been reported to be associated with reduced survival in several malignancies, including endometrial cancer. This study investigated immunoreactivity to YKL-40 protein and its prognostic implications in endometrial cancer. Levels of YKL-40 protein in normal endometrium (n = 42), endometrial hyperplasia (n = 40) and endometrial adeno carcinoma (n = 68) were examined using immunohistochemistry. YKL-40 immunoreactivity was significantly higher in endometrial adenocarcinoma compared with hyperplastic and normal endo metrium. In addition, high immuno reactivity of YKL-40 protein was associated with advanced stage, high histological grade, lymph node metastasis and lympho vascular invasion. Moreover, positive immunoreactivity for YKL-40 was a significant predictor of poor prognosis, as measured by estimated progression-free survival and estimated overall survival, compared with negative immunoreactivity. In conclusion, high YKL-40 immuno reactivity in endometrial cancer may be associated with poor prognosis.

[Hypoxia induced HIF-1 accumulation and VEGF expression in gastric epithelial mucosa cell: involvement of ERK1/2 and PI3K/Akt]

Hypoxia is a common environmental stress that influences signaling pathways and cells function, which through initiating intracellular signaling pathways and hence leading to the activation of the transcription factor hypoxia-inducible factor-1 (HIF-1). In this study, we initially confirm that hypoxia activates HIF-1alpha protein expression in a time-dependent manner with a maximum reached at 60 min in vitro and 4h in vivo in gastric mucosa epithelial cells. The expression of HIF-1alpha is correlated with the activation of HIF-1 DNA binding and transcriptional activity. Hypoxia dose not affect HIF-1alpha mRNA transcription but regulates HIF-1alpha protein expression through a translation-dependent pathway to regulate protein synthesis. Hypoxia could induce phosphorylation of Akt, MAPK (ERK), and target of p70S6K1. PI3K and MAPK inhibitor, LY294002 and U0126 could inhibit hypoxia-induced HIF-1 and VEGF expression. We also investigated the role of reactive oxygen species (ROS) involved in HIF-1 and VEGF expression Exogenous addition of H2O2 was sufficient to activate Akt and ERK, scavengers of H2O2 significantly inhibited hypoxia-induced Akt and ERK, and subsequent HIF-lax expression and transcriptional activity. In conclusion, our data suggested that hypoxia- PI3K signaling through Akt and ERK kinases regulated ROS-dependent, hypoxia- induced HIF-1 activation and VEGF expression in gastric mucosa epithelial cells.

Multidrug-resistance-associated protein MGr1-Ag is identical to the human 37-kDa laminin receptor precursor

We report the isolation and functional characterization of the gene encoding MGr1-Ag, a multidrug-resistance-associated protein. A lambdagt11 cDNA library derived from colorectal carcinoma SW480 cells was screened with monoclonal antibody MGr1. DNA homology analysis of 22 positive clones (designated R1-R22) suggested human 37-kDa laminin receptor precursor (37LRP, R7/R9/R15/R16/R19/R20) and a novel gene (R22) as candidate genes encoding MGr1-Ag. Western blot analysis showed that anti-R20 serum reacted with a unique protein band that was consistent with MGr1-Ag, while anti-R22 serum could not react with MGr1-Ag. The coding gene for MGr1-Ag was amplified using reverse transcription-PCR. Sequence analysis revealed that the MGr1-Ag and 37LRP genes shared the same coding sequence. An in vitro drug sensitivity assay indicated that down-regulation of 37LRP by an antisense technique could significantly enhance the cytotoxicity of anticancer drugs to gastric cancer cells. Thus we draw the conclusion that MGr1-Ag is identical to 37LRP.

beta -Amyloid peptide-induced apoptosis regulated by a novel protein containing a g protein activation module

Degeneration of neurons in Alzheimer's disease is mediated by beta-amyloid peptide by diverse mechanisms, which include a putative apoptotic component stimulated by unidentified signaling events. This report describes a novel beta-amyloid peptide-binding protein (denoted BBP) containing a G protein-coupling module. BBP is one member of a family of three proteins containing this conserved structure. The BBP subtype bound human beta-amyloid peptide in vitro with high affinity and specificity. Expression of BBP in cell culture induced caspase-dependent vulnerability to beta-amyloid peptide toxicity. Expression of a signaling-deficient dominant negative BBP mutant suppressed sensitivity of human Ntera-2 neurons to beta-amyloid peptide mediated toxicity. These findings suggest that BBP is a target of neurotoxic beta-amyloid peptide and provide new insight into the molecular pathophysiology of Alzheimer's disease.

HOE-642 (cariporide) alters pH(i) and diastolic function after ischemia during reperfusion in pig hearts in situ

The specific Na(+)/H(+) exchange inhibitor HOE-642 prevents ischemic and reperfusion injury in the myocardium. Although this inhibitor alters H(+) ion flux during reperfusion in vitro, this action has not been confirmed during complex conditions in situ. Myocardial intracellular pH (pH(i)) and high-energy phosphates were monitored using (31)P magnetic resonance spectroscopy in open-chest pigs supported by cardiopulmonary bypass during 10 min of ischemia and reperfusion. Intravenous HOE-642 (2 mg/kg; n = 8) administered before ischemia prevented the increases in diastolic stiffness noted in control pigs (n = 8), although it did not alter the postischemic peak-elastance or pressure-rate product measured using a distensible balloon within the left ventricle. HOE-642 induced no change in pH(i) during ischemia but caused significant delays in intracellular realkalinization during reperfusion. HOE-642 did not alter phosphocreatine depletion and repletion but did improve ATP preservation. Na(+)/H(+) exchange inhibition through HOE-642 delays intracellular alkalinization in the myocardium in situ during reperfusion in association with improved diastolic function and high-energy phosphate preservation.

Animal study on lung injury caused by simulant segmented shock waves

OBJECTIVE

To study the lung injury caused by segmented shock waves.

METHODS

A total of 60 rabbits and 20 rats were used in this study. The process of transmission of shock waves was divided into three phases, i.e., the recompression phase (RP), the decompression phase (DP) and the underpressure phase (UP). And the recompression wave (RW), the decompression wave (DW) a nd the underpressure wave (UW) simulated the three phases, respectively, generated by the equipment designed by us. The RW test, DW test and UW test were respectively applied to the animals. And lung injuries caused by segmented shock waves were discussed.

RESULTS

Under the experimental conditions, the RW did not cause obvious lung injury, but the DW could cause different severities of lung injuries. The greater the decompression ranged and the shorter the decompression duration was adopted, the more severe the lung injury was observed. The UW, to some extent, could cause obvious lung injury.

CONCLUSIONS

It suggests that lung injury under shock waves probably occurs during the DP primarily. It probably does not cause direct obvious lung injury during the RP, but significantly influences the capability of causing lung injury during the DP.

CPP calculation of multiple scattering distributions for charged particles penetrating compounds or mixtures

Charged particle multiple scattering distributions may be constructed from individual atomic scattering events on the basis of compound Poisson process (CPP) theory. We present a CPP method for computing multiple scattering transition probability densities from charged particles penetrating compounds and mixtures. Water as a scattering medium provides here an example of the calculation method which is applicable to compounds or mixtures. Electrons are chosen as examples of charged particle beams. The Rutherford single scattering cross section and a partial wave analysis single scattering cross section are chosen as example cross sections. Transition probability densities predicted on the basis of CPP theory can be calculated with great accuracy for the improvement of radiation dose calculations. The advantages of the CPP method are (a) an effective atomic number need not be defined for the scattering medium, (b) it can be applied in both spherical and planar coordinate systems, and (c) it does not require any specific form for the single scattering cross section.

Cell surface expression of immature H glycoprotein in measles virus-infected cells

Two forms of hemagglutinin (H) protein, one with an apparent molecular mass of 78 kDa (78K H protein) and the other with that of 74 kDa (74K H protein), are present in cells infected with measles virus (MV). We previously observed that only the mature 78K H protein, a completely glycosylated form of the 74K H protein, was expressed on the cell surface of the infected cells. In the present study, we detected transient expression of the 74K H protein on the cell surface of infected cells by pulse-chase studies, although the level of this expression was much lower than that of the 78K H protein. On the cell surface the 74K H protein was present as dimers and sensitive to endo-beta-N-acetylglucosaminidase H digestion. Treatment with brefeldin A, which blocks the transport of membrane and secretory proteins from the endoplasmic reticulum to the Golgi apparatus, inhibited the cell surface expression of the 78K H protein, but not that of the 74K H protein. These data suggest that a part of the MV 74K H proteins could be transported directly to the cell surface - probably via an alternative pathway - without processing to the complex form in the Golgi apparatus.

Quantitative analysis of gene function in the Drosophila embryo

The specific functions of gene products frequently depend on the developmental context in which they are expressed. Thus, studies on gene function will benefit from systems that allow for manipulation of gene expression within model systems where the developmental context is well defined. Here we describe a system that allows for genetically controlled overexpression of any gene of interest under normal physiological conditions in the early Drosophila embryo. This regulated expression is achieved through the use of Drosophila lines that express a maternal mRNA for the yeast transcription factor GAL4. Embryos derived from females that express GAL4 maternally activate GAL4-dependent UAS transgenes at uniform levels throughout the embryo during the blastoderm stage of embryogenesis. The expression levels can be quantitatively manipulated through the use of lines that have different levels of maternal GAL4 activity. Specific phenotypes are produced by expression of a number of different developmental regulators with this system, including genes that normally do not function during Drosophila embryogenesis. Analysis of the response to overexpression of runt provides evidence that this pair-rule segmentation gene has a direct role in repressing transcription of the segment-polarity gene engrailed. The maternal GAL4 system will have applications both for the measurement of gene activity in reverse genetic experiments as well as for the identification of genetic factors that have quantitative effects on gene function in vivo.

Cholesterol efflux-mediated signal transduction in mammalian sperm: cholesterol release signals an increase in protein tyrosine phosphorylation during mouse sperm capacitation

We previously demonstrated that mouse sperm capacitation is accompanied by a time-dependent increase in protein tyrosine phosphorylation that is dependent on the presence of BSA, Ca2+, and NaHCO(3), all three of which are also required for this maturational event. We also demonstrated that activation of protein kinase A (PK-A) is upstream of this capacitation-associated increase in protein tyrosine phosphorylation. BSA is hypothesized to modulate capacitation through the removal of cholesterol from the sperm plasma membrane. In this report, we demonstrate that incubation of mouse sperm medium containing BSA results in a release of cholesterol from the sperm plasma membrane to the medium; release of this sterol does not occur in medium devoid of BSA. We next determined whether cholesterol release leads to changes in protein tyrosine phosphorylation. Blocking the action of BSA by adding exogenous cholesterol-SO-(4) to the BSA-containing medium inhibits the increase in protein tyrosine phosphorylation as well as capacitation. This inhibitory effect is overcome by (1) the addition of increasing concentrations of BSA at a given concentration of cholesterol-SO-(4) and (2) the addition of dibutyryl cAMP plus IBMX. High-density lipoprotein (HDL), another cholesterol binding protein, also supports the capacitation-associated increase in protein tyrosine phosphorylation through a cAMP-dependent pathway, whereas proteins that do not interact with cholesterol have no effect. HDL also supports sperm capacitation, as assessed by fertilization in vitro. Finally, we previously demonstrated that HCO-(3) is necessary for the capacitation-associated increase in protein tyrosine phosphorylation and demonstrate here, by examining the effectiveness of HCO-(3) or BSA addition to sperm on protein tyrosine phosphorylation, that the HCO-(3) effect is downstream of the site of BSA action. Taken together, these data demonstrate that cholesterol release is associated with the activation of a transmembrane signal transduction pathway involving PK-A and protein tyrosine phosphorylation, leading to functional maturation of the sperm.

Surveillance of risk factors from imported cases of falciparum malaria in Sichuan, China

With a sharp increase of the number of imported cases of falciparum malaria, the potential risk of the reemergent transmission of this kind of malaria is approaching imminently in Sichuan Province, China, where falciparum malaria had completely been eliminated by the 1960s. It has been of concern whether the epidemic would appear again, because there still exist malaria vectors and vulnerable populations in Sichuan. By undertaking surveillance on 31 cases returning from the endemic areas with falciparum malaria, and on their family members and neighbors, we have not found out any introduced case of falciparum malaria who was contracted from the imported ones. The vector monitoring results suggested that the use of insecticide-impregnated bednets interfered with malaria vectorial capacity and expectation of infective life. The epidemiological characteristics of the imported cases and reasons why no consequent malaria case was detected were analysed at dynastic level in detail.

Cholesterol efflux-mediated signal transduction in mammalian sperm. beta-cyclodextrins initiate transmembrane signaling leading to an increase in protein tyrosine phosphorylation and capacitation

Sperm capacitation in vitro is highly correlated with an increase in protein tyrosine phosphorylation that is regulated by cAMP through a unique mode of signal transduction cross-talk. The activation of this signaling pathway, as well as capacitation, requires bovine serum albumin (BSA) in the incubation medium. BSA is hypothesized to modulate capacitation through its ability to remove cholesterol from the sperm plasma membrane. Here we demonstrate that the cholesterol-binding heptasaccharides, methyl-beta-cyclodextrin and OH-propyl-beta-cyclodextrin, promote the release of cholesterol from the mouse sperm plasma membrane in media devoid of BSA. Both of these beta-cyclodextrins were also demonstrated to increase protein tyrosine phosphorylation in the absence of BSA in both mouse and bull sperm, and the patterns of phosphorylation were similar to those induced by media containing BSA. The potency of the different beta-cyclodextrins to increase protein tyrosine phosphorylation in sperm was correlated with their cholesterol binding efficiencies, and preincubation of the beta-cyclodextrins with cholesterol-SO4- to saturate their cholesterol-binding sites blocked the ability of these compounds to stimulate protein tyrosine phosphorylation. The beta-cyclodextrin effect on protein tyrosine phosphorylation was both NaHCO3 and protein kinase A-dependent. The beta-cyclodextrins were also able to capacitate mouse sperm in the absence of BSA, as measured by the ability of the zona pellucida to induce the acrosome reaction and by successful fertilization in vitro. In summary, beta-cyclodextrins can completely replace BSA in media to support signal transduction leading to capacitation. These data further support the coupling of cholesterol efflux to the activation of membrane and transmembrane signaling events leading to the activation of a unique signaling pathway involving the cross-talk between cAMP and tyrosine kinase second messenger systems, thus defining a new mode of cellular signal transduction initiated by cholesterol release.

[Clinical and experimental study on the Houpu Mahuang oral liquid in treating bronchial asthma]

OBJECTIVE

To probe into the curative effect and mechanism of action of the Houpu Mahuang oral liquid (HPMH) in treating bronchial asthma.

METHODS

The pulmonary function and level of serum IgE of the patients were determined before and after HPMH treatment. The anti-allergic reaction and relieving spasm effect of HPMH in animal were also observed.

RESULTS

HPMH is not only effective in improving clinical symptoms and pulmonary function (P < 0.05), so as to lower the abnormal raising of IgE (P < 0.01), but also has a notable inhibitory effect for passive allergic reaction of rat's skin, it can relieve spasm.

CONCLUSIONS

HPMH is effective in relieving spasm, antiallergic reaction, it can improve the symptoms of bronchial asthma.

[Differentiation of mumps virus strains by polymerase chain reaction and silver stained single-strand conformation polymorphism analysis]

The cDNA fragments amplified through nested RT-PCR from the small hydrophobic (SH) protein gene and its flanking region of the five wild mumps viruses and Enders strain were subjected to single-strand conformation polymorphism (SSCP) analysis by using silver staining. These five wild isolates could be divided into three SSCP patterns and they were differentiated from the Enders strain. Two wild strains which have 3.4% heterology of the nucleotide acid sequence could be distinguished by the method. The results were well correlated with sequence analysis of the SH gene segments, indicating high applicability of the silver staining SSCP analysis for differentiation of mumps virus strains. Furthermore, the method, which is not only quick, sensitive, safe and reliable, but also reproducible and inexpensive, can be used in the molecular epidemiology study of mumps viruses.