[En1 promotes cell proliferation and migration via Hedgehog signaling pathway in esophageal squamous cell carcinoma]

Objective: To explore the function and mechanism of transcription factor En1 in esophageal squamous cell carcinoma (ESCC). Methods: The correlations of En1 with prognosis were analyzed using the overall survival data of 9 397 pan-cancer patients and progression-free survival data of 4 349 pan-cancer patients from The Cancer Genome Atlas (TCGA) database. The En1 expression data in 53 and 155 cases of ESCC and their paired adjacent tissues were from Gene Expression Omnibus (GEO) database and National Genomics Data Center-Genome Sequence Archive(NGDC-GSA)database. Lentivirus was used to generate En1 stable knockout cell lines KYSE180 and KYSE450. The proliferation ability of the cells was detected by cell counting kit 8 and clone formation assay. The migration ability of the cells was detected by Transwell assay. The effect of En1 on the proliferation of ESCC was detected by xenograft experiment in BALB/c-nu/nu mice. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the expressions of En1, glioma-associated oncogene family zinc finger 1 (GLI1), glioma-associated oncogene family zinc finger 2 (GLI2) and smoothened (SMO). Results: Pan-cancer data from TCGA showed that patients with low En1 expression had longer overall survival and progression-free survival than patients with high En1 expression (P< 0.001). Data from GEO and GSA databases also showed a high expression level of En1 in ESCC tissues compared with paired tissues (P＜0.001). Proliferation was inhibited after knockout of En1 in KYSE180 and KYSE450 cells (P＜0.001). The colony formation numbers decreased. The colony formation numbers of KYSE180 cells in the shEn1#1 group and the shEn1#2 group were 138.33±23.07 and 127.00±19.70, respectively, significantly lower than that of the shNC group 340.67±12.06 (P<0.001). The colony formation numbers of KYSE450 cells in the shEn1#1 group and the shEn1#2 group were 65.33±2.52 and 9.00±3.00, respectively, significantly lower than that of the shNC group 139.00±13.00 (P<0.001). The migration numbers was inhibited after knockout of En1 [the Transwell numbers of KYSE180 cells in the shEn1#1 group and the shEn1#2 group were 66.67±12.66 and 71.33±11.02, respectively, significantly lower than that of the shNC group 334.67±16.56 (P<0.001). The Transwell numbers of KYSE450 cells in the shEn1#1 group and the shEn1#2 group were 112.33±14.57 and 54.33±5.51, respectively, significantly lower than that of the shNC group 253.33±21.03 (P<0.001)]. Xenograft model showed a slower growth rate of shEn1#1 and shEn1#2 cell lines (P＜0.001). The tumor weights of KYSE450 cells in the shEn1#1 group and the shEn1#2 group were (0.046±0.026)g and (0.047±0.025)g, respectively, significantly lower than that of the shNC group (0.130±0.038)g (P＜0.001). After knockdown of En1, the relative expression levels of GLI1 in KYSE180 cells of the shEn1#1 group and the shEn1#2 group were 0.326±0.162 and 0.322±0.133, and the relative expression levels of GLI1 in KYSE450 cells of the shEn1#1 and shEn1#2 groups were 0.131±0.006 and 0.352±0.050, respectively, which were all lower than that in the shNC group (P＜0.01). After knockdown of En1, overexpression of GLI1 attenuated the inhibitory effect of knockdown of En1 on cell proliferation (P＜0.001), colony formation[the colony formation numbers of the shEn1#1-GLI1 group were 151.00±9.54, higher than 102.33±10.02 (P=0.004) of the shEn1#1-vector group] and migration [the migration numbers of the shEn1#1-GLI1 group were 193.67±10.07, higher than 109.33±11.50 (P<0.001) in the shEn1#1-vector group]. In clinical samples of ESCC, major regulatory factors of the Hedgehog pathway were up-regulated and the pathway was activated. Conclusion: En1 promotes the proliferation and migration of ESCC cells by regulating the Hedgehog pathway and can be used as a new potential target for targeted therapy of ESCC.

[Intraoperative cochlear nerve monitoring in microvascular decompression of hemifacial spasm and resection of vestibular schwannoma]

Objective: To analyze the application of direct cochlear nerve monitoring technology-cochlear nerve action potential (CNAP) monitoring in resection of vestibular schwannoma (VS) and to compare with which in microvascular decompression (MVD) of hemifacial spasm (HFS), in order to provide reference for identification of the cochlear nerve during VS resection surgery and predicting postoperative hearing preservation. Methods: From June 2018 to March 2022, patients with facial spasm and vestibular schwannoma who underwent retrosigmoid approach surgery at the Chinese PLA General Hospital were collected. Before surgery, there were a total of 11 HFS patients and 30 VS patients. Before surgery, the former had hearing level of class A(AAO-HNS), while the latter had serviceable hearing (AAO-HNS class A-B), with a maximum tumor diameter of≤20 mm. CNAP combined with Auditory Brainstem Response (ABR) monitoring was performed during surgery. SPSS 23.0 software was used to analyze the differences of ABR and CNAP parameters between the two groups. Results: The preoperative ABR test in the VS group showed that the latency of wave V and I-V interval were significantly prolonged compared to the HFS group (t=8.36, P<0.001; t=4.61, P<0.001).In VS group, all tumors were totally removed with preserved facial nerve function (House-Brackmann grade Ⅰ-Ⅱ). The serviceable hearing preservation rate was 63.3%. In the HFS group, the initial CNAP waveforms were triphasic and biphasic, with N1 wave latency of (4.32±0.37) ms and amplitude of 25.20 [15.63, 35.40]μV. The distribution of CNAP waveforms before tumor resection in the VS group was the same as that in the HFS group, and which in the hearing preservation group after surgery was also the same. Compared with the HFS group, the latency of N1 wave was prolonged (t=2.670, P=0.011;t=4.584, P<0.001), and the amplitude of N1 wavein the VS group before tumor resection was lower (Z=-3.001, P=0.003). The amplitude of N1 wave in the hearing preservation group after surgery was 20.20 [6.23, 40.90] μV,which was significantly higher than that before tumor resection (Z=-2.133, P=0.033), but there was no statistically significant difference compared to the HFS group (Z=-0.495, P=0.621). Conclusions: The reference range of CNAP in normal hearing population can be preliminarily obtained by the analysis of CNAP in MVD surgery. The latency of N1 wave in VS patients is prolonged and the amplitude of N1 wave is decreased due to tumor compression. The CNAP waveform combined with the change of N1 wave amplitude can provide reference for intraoperative mapping of the cochlear nerve and prediction of postoperative hearing preservation.

A comprehensive analysis of nucleotide excision repair characteristics defines a novel prognostic signature for acute myeloid leukemia

OBJECTIVE

Nucleotide excision repair (NER) has been associated with various types of malignant tumors. However, the precise roles of nucleotide excision repair-related genes (NERGs) in acute myeloid leukemia (AML) remain incompletely understood. Hence, this study aimed to develop a prognostic signature incorporating NERGs in AML, which could potentially predict patient outcomes.

MATERIALS AND METHODS

By querying the Genotype-Tissue Expression (GTEx), The Cancer Genome Atlas (TCGA), and Gene Expression Omnibus (GEO) databases, we acquired RNA-seq data and clinical information pertaining to AML. To identify differentially expressed NERGs (DE-NERGs), we employed the Wilcoxon rank-sum test. Based on the expression patterns of DE-NERGs with prognostic significance, patients were categorized into two subgroups. A prognostic signature was developed through univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analyses to compare the differentially expressed genes (DEGs) between these two groups. Additionally, a nomogram was constructed using multivariate analysis. The biological pathways involved were elucidated through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, gene set variation analysis (GSVA), and gene set enrichment analysis (GSEA).

RESULTS

We developed a prognostic model based on an 11-gene signature. Furthermore, the risk score derived from this model was demonstrated to independently serve as a prognostic marker for patients diagnosed with AML.

CONCLUSIONS

Our prognostic model, based on NERGs, was developed and validated to provide insights into the onset and progression of AML and establish a foundation for more effective treatment. Our findings not only contribute to clinical decision-making but also underscore the significance of nucleotide excision repair. Furthermore, they may pave the way for the development of targeted therapeutic strategies specifically focused on this process.

Reduced blood circulating calcium level is an outstanding biomarker for preeclampsia among 48 types of human diseases

BACKGROUND

Calcium ion (Ca2+) is essential for human physiology by regulating various signal transduction pathways inside all cells and in the blood circulation.

AIM

We compared circulating Ca2+ levels in the healthy control against 48 different types of human diseases.

DESIGN

A total of 144 201 independent test results of Ca2+ levels from 48 clinically defined diseases and 141 679 independent test results of Ca2+ from healthy individuals who came to the hospital for annual physical examination were retrieved during the past 5 years.

METHODS

Ca2+ was determined by the standard 'Arsenazo III method' in the clinical laboratory of Affiliated Hospital of Qingdao University. We analyzed all data using RStudio V.1.3.1073 and python libraries 3.8.

RESULTS

All 48 types of diseases had decreased Ca2+ levels than the healthy control based on either mean or median values. Patients suffering from preeclampsia had the lowest Ca2+ levels among all 48 diseases. The perfect area under the curve, sensitivity, and specificity values of 1.0, 0.96 and 0.96 indicated that Ca2+ was an excellent biomarker for diagnosing preeclampsia. Extremely low Ca2+ was present in patients suffering kidney-related diseases. Since the correlation between each disease on the statistical features is proportional to their vector distance, the two-component analysis revealed that preeclampsia, sepsis and chronic obstructive pulmonary disease were closely related among 48 diseases.

CONCLUSIONS

All human diseases were associated with reduced circulating Ca2+ levels, where the decreased Ca2+ was a perfect biomarker for preeclampsia. Kidney-related conditions were related to over-down-regulation of Ca2+ levels. The resemblance of preeclampsia to sepsis and chronic obstructive pulmonary disease based on two-component analysis suggested that the three unrelated diseases might share a similar mechanism of the circulating Ca2+ regulation.

Analysis of the MCL-1 gene in Chinese women with idiopathic premature ovarian insufficiency

OBJECTIVE

Animal studies have demonstrated that myeloid cell leukemia-1 (Mcl-1) gene deficiency leads to premature ovarian failure and decreased reproductive ability in mice. This study investigated the relationship between MCL-1 gene variation and idiopathic premature ovarian insufficiency (POI) in Chinese women.

METHODS

A total of 200 idiopathic POI patients and 100 healthy controls were recruited for this study, and peripheral blood was collected. First, genomic DNA was extracted from peripheral leukocytes. Then, the entire coding region and splice sites of the MCL-1 gene were amplified by polymerase chain reaction. Chi-squared tests were used to compare the genotype distribution and allele frequency of single nucleotide polymorphisms between the POI and control groups.

RESULTS

Three mutations of the MCL-1 gene (c.-36C > T, c.-131C > T and c.78C > T) were identified. After data analysis, c.-36C > T and c.-131C > T in the 5'-untranslated region were both found in the POI group and the control group. No difference was found in the genotype distribution or allelic frequency of either variant between the POI group and the control group (p > 0.05). The synonymous variant (c.78C > T) in exon 1 was discovered in only one of the control subjects and did not result in a change in amino acid sequence (p.Gly26Gly).

CONCLUSION

MCL-1 gene mutation may not be associated with idiopathic POI in Chinese women.

[Management of toxicities associated with pegaspargase in treatment of patients with lymphoid malignancy: experience from 443 cases in a single center]

目的

总结培门冬酶治疗淋巴系统肿瘤的不良反应以及处理经验。

方法

通过回顾性分析北京同仁医院血液科2011年8月至2015年12月使用培门冬酶患者的临床资料，总结培门冬酶相关的不良反应以及处理经验。

结果

129例患者使用培门冬酶，累计共使用443例次，不良反应发生情况：2例（1.6%）患者出现过敏反应；19例（14.7%）患者发生胰腺炎（其中包括6例急性症状性胰腺炎、13例单纯胰酶升高的化学性胰腺炎），15例（11.6%）患者出现高甘油三酯血症，85例（65.9%）患者出现高血糖，7例（5.4%）患者出现低血糖；25例（19.4%）患者出现2级以上的转氨酶增高，21例（15.5%）患者发生高胆红素血症，62例（48.1%）患者发生低白蛋白血症；61例（47.3%）患者出现APTT延长，22例（17.1%）患者出现PT延长，15例（11.6%）患者出现TT延长，75例（58.1%）患者出现低纤维蛋白原血症，有11例患者（8.5%）出现血栓事件，有3例（2.3%）患者出现活动性出血。以上不良反应，分别经过抗过敏、抑制胰液分泌、降脂、降糖、保肝、补充血浆、止血等对症治疗后症状均好转。部分严重不良反应影响培门冬酶的按计划应用甚至导致停用。

结论

培门冬酶的不良反应非常广泛，有些非常严重，需要治疗时密切监测。

Effects of dietary supplementation with carnosine on meat quality and antioxidant capacity in broiler chickens

1. This study aimed to investigate the effects of carnosine supplementation on meat quality, antioxidant capacity and lipid peroxidation status in broiler chickens. 2. A total of 256 1-d-old male Arbor Acres broilers were randomly assigned to 4 treatments consisting of 8 replicates of 8 chickens each. The birds were supplied with 4 different diets: a basal diet or a basal diet supplemented with 100, 200 or 400 mg/kg carnosine, respectively. The whole experiment lasted 42 d. 3. The results showed that dietary supplementation with carnosine linearly increased the values of pH_45 min and redness and reduced drip loss of breast meat. Dietary carnosine increased the activity of antioxidant enzymes in liver, serum and breast meat and decreased the contents of lipid peroxides at 21 and 42 d of age. 4. These findings indicated that dietary supplementation with carnosine was beneficial to enhance meat quality, antioxidant capacity and decrease lipid peroxidation status of breast meat.

Zoledronic Acid Improves Bone Quality in the Streptozotocin-Induced Diabetes Rat through Affecting the Expression of the Osteoblast-Regulating Transcription Factors

AIMS

To evaluate the short term effect of zoledronic acid on bone remodeling in the streptozotocin induced diabetes rats.

MATERIALS AND METHODS

Diabetes was induced by an injection of streptozotocin (60 mg/kg). The rats were treated with zoledronic acid (0.1 mg/kg) at the onset of diabetes (Z-I group) and 2 weeks later (Z-II group). Rats were sacrificed at the 1, 2, 3, 4 and 5 weeks after the onset of diabetes. Real-time PCR and western blot were performed to detect the expression of the following osteogenic gene mRNAs and their proteins: bone morphogenetic proteins 2 (BMP2), Runx2, Osterix and Noggin. The bone mineral density (BMD) and the mechanical resistance test was measured.

RESULTS

BMP2, Runx2 and Osterix mRNA and protein expression in group D had regulated down, while Noggin expression increased. Z-I treatment could reverse the results. However group Z-II showed only a transient reversing effect. On the 5^th week in group D, the BMD decreased, the bone trabecular distance increased, while the trabecular thickness and bone trabecular volume were reduced, the biomechanics index decreased significantly. Zoledronic acid treatment restored these alterations.

CONCLUSIONS

Zoledronic acid administered in the early stage of the diabetes could prevent the osteopenia. The underlying mechanisms might be that zoledronic acid treatment reversed the effect of diabetes on the expression of osteoblast-regulating transcription factors: BMP2, Runx2 and Osterix.

Low miR-498 expression levels are associated with poor prognosis in ovarian cancer

OBJECTIVE

Decreased expression levels of microRNA (miR)-498 were reported in several human cancers. However, the prognostic value of the miR-498 expression in ovarian cancer has not been assessed. In this study, we addressed this knowledge gap by evaluating an association of miR-498 expression levels with ovarian cancer prognosis.

PATIENTS AND METHODS

qPCR was used to detect expression levels of miR-498 in cancer specimens and matched adjacent normal tissue specimens. The log-rank test was used to analyze survival rate, whereas the Cox regression model was used fir multivariate analysis of potential prognostic factors.

RESULTS

Expression levels of miR-498 were significantly lower in ovarian cancer tissue specimens compared with matched normal adjacent tissue (p < 0.001). Decreased miR-498 expression levels correlated well with FIGO stage, tumour grade and lymph node metastases (respective p = 0.001, 0.015, and 0.017). Furthermore, patients with lower miR-498 expression had shorter overall and progression-free survival (both p < 0.01 vs. those with high miR-498 expression).

CONCLUSIONS

Decreased expression levels of miR-498 are associated with worse overall survival and poor prognosis in patients with ovarian cancer, highlighting potential usefulness of this miR for prognosis in patients with ovarian cancer.

Thefurrygene ofDrosophilais important for maintaining the integrity of cellular extensions during morphogenesis

The Drosophila imaginal cells that produce epidermal hairs, the shafts of sensory bristles and the lateral extensions of the arista are attractive model systems for studying the morphogenesis of polarized cell extensions. We now report the identification and characterization of furry, an essential Drosophila gene that is involved in maintaining the integrity of these cellular extensions during morphogenesis. Mutations in furry result in the formation of branched arista laterals, branched bristles and a strong multiple hair cell phenotype that consists of clusters of epidermal hairs and branched hairs. By following the morphogenesis of arista laterals in pupae, we have determined that the branched laterals are due to the splitting of individual laterals during elongation. In genetic mosaics furry was found to act cell autonomously in the wing. The phenotypes of double mutant cells argue that furry functions independently of the frizzled planar polarity pathway and that it probably functions in the same pathway as the tricornered gene. We used a P-element insertion allele as a tag to clone the furry gene and found it to be a large and complicated gene that encodes a pair of large conserved proteins of unknown biochemical function.

A BODIPY fluorescent microplate assay for measuring activity of calpains and other proteases

The use of 4,4-difluoro-5,7-dimethyl-4-bora-3a, 4a-diaza-s-indacene-3-propionic acid (BODIPY-FL) labeled casein in autoquenching assays of proteolytic activity has been recently described, and we have adapted this assay to measurement of calpain activity. BODIPY-FL coupled to casein at a ratio of 8 mol of BODIPY-FL/mol of casein or higher produces a BODIPY-FL-casein substrate that can be used in an autoquenching assay of calpain proteolytic activity. This assay has a number of advantages for measuring calpain activity. (1) The procedure does not require precipitation and removal of undegraded protein, so it is much faster than other procedures that require a precipitation step, and it can be used directly in kinetic assays of proteolytic activity. (2) The BODIPY-FL-casein assay is easily adapted to a microtiter plate format, so it can be used to screen large numbers of samples. (3) Casein is an inexpensive and readily available protein substrate that more closely mimics the natural substrates of endoproteinases, such as the calpains, than synthetic peptide substrates do. Casein has K(m) values for micro- and m-calpain that are similar to those of other substrates such as fodrin or MAP2 that may be "natural" substrates for the calpains, and there is no reason to believe that calpain hydrolysis of casein is inherently different from hydrolysis of fodrin or MAP2, which are much less accessible as substrates for protease assays. (4) The BODIPY-FL-casein assay is capable of detecting 10 ng ( approximately 5 nM) of calpain and is nearly as sensitive as the most sensitive calpain assay reported thus far. (5) The BODIPY-FL-casein assay is as reproducible as the FITC-casein assay, whose reproducibility is comparable to or better than the reproducibility of other methods used to assay calpain activity. The BODIPY-FL-casein assay is a general assay for proteolytic activity and can be used with any protease that cleaves casein.

Isolation of differentially expressed cDNAs from p53-dependent apoptotic cells: activation of the human homologue of the Drosophila peroxidasin gene

Inactivation of the p53 tumor suppressor protein has been observed in a large number of human cancers. Overexpression of p53 induces either growth arrest or programmed cell death (apoptosis). The growth arrest function of p53 is mediated by induction of p21 (WAF1/CIP1), but the mechanisms underlying p53-dependent apoptosis are still largely unknown. To investigate these mechanisms, we have identified six differentially expressed transcripts in a human colon cancer cell line undergoing p53-dependent apoptosis. One of the p53-responsive genes showed significant homology to Drosophila peroxidasin, an extracellular matrix-associated peroxidase, and is likely to be its human homologue. Our results suggest a possible connection between p53-dependent apoptosis and the production of reactive oxygen species.

[Effect of total flavonoids of radix Astragali on free radical production by myocardial ischemia-reperfusion in rats]

Observation was made on the effect of TFA on FR produced by ischemia-reperfusion in two groups of Langendorff hearts of rats. The result showed that oxygen free radicals were reduced by TFA in myocardial ischemia-reperfusion in rats.

Effect of monoclonal antibodies specific for the 28-kDa subunit on catalytic properties of the calpains

Nine monoclonal antibodies (mAbs) specific for the 28-kDa subunit common to mu- and m-calpains have been assayed for their effects on mu- and m-calpains. All nine react with the COOH-terminal part (domain VI) of the 28-kDa subunit, and all nine affect the Ca2+ concentration required for autolysis of m-calpain, but have little effect on the Ca2+ concentration required for autolysis of mu-calpain. None of the nine affect the specific proteolytic activity of mu- or m-calpain. Two of the mAbs, 5B9 and 5B3, were selected for further study. mAb 5B9 decreased the Ca2+ concentration required for autolysis to one-fifth of that required in its absence; sequencing of chymotryptic fragments showed that the epitope for mAb 5B9 is between amino acid residues 92 and 104 of the 28-kDa subunit. mAb 5B3 increased the Ca2+ concentration required for autolysis; the epitope for mAb 5B3 is located between amino acid residues 148 and 178 of the 28-kDa subunit, which is the region that contains the first EF-hand Ca(2+)-binding sequence in this subunit. Although it increases the Ca2+ concentration required for autolysis, mAb 5B3 has no effect on the Ca2+ concentration required for proteolytic activity of m-calpain, and unautolyzed m-calpain is not a proenzyme. That all nine mAbs react with domain VI and not with the NH2-terminal domain V of the 28-kDa subunit suggests that domain VI (and not domain V) is involved in autolysis, contrary to the view that phosphatidylinositol lowers the Ca2+ concentration required for autolysis by binding to domain V.

Election spin resonance studies of free radical formation and oxygen consumption of lens epithelium during ultraviolet exposure

A long life election spin resonance (ESR) signal at g = 2.0006 was observed in the normal lens epithelium and cortical fibers. During ultraviolet (UV) exposure, a new ESR signal at g = 2.0060 was found in the lens epithelium. But this specific signal was not detected in the lens cortical fibers. This suggested that lens epithelial cells were more susceptible to the free radical formation which was induced by UV light. By means of ESR spin probe oximetry, the oxygen uptake of lens epithelial cells was measured. The more the oxygen uptake, the higher the K value was. The K value of the oxygen consumption of epithelial cell linearly correlated with time of consumption (20-60 min) and increased as a function of UV exposure time (1-5 min). The oxygen consumption rate of lens epithelial cell was approximately 1.38 x 10(6) and increased to 7.1 x 10(6) O2 molecules per cell per sec. The oxygen consumption rate increased more than 5 times. These results indicates that UV light can accelerate the respiratory function of lens epithelial cells. The necessity of excess oxygen of lens epithelial cells may play a role in the cataract formation induced by UV light.

The role of autolysis in activity of the Ca2+-dependent proteinases (mu-calpain and m-calpain)

A recent hypothesis suggests that proteolytic activity of the micromolar and millimolar Ca2+-requiring forms of the Ca2+-dependent proteinases (mu- and m-calpain, respectively) is regulated in vivo by their association with a phosphatidylinositol-containing site on the plasma membrane followed by autolysis of the proteinases. Phosphatidylinositol association lowers the Ca2+ concentration needed for autolysis, and autolysis, in turn, lowers the Ca2+ concentration needed for proteolytic activity. To test this hypothesis, we have compared the Ca2+ concentrations needed for autolysis and for proteolytic activity of the calpains both in the presence and the absence of phosphatidylinositol. Bovine skeletal muscle mu-calpain required 40-50 microM Ca2+ for half-maximal rate of proteolysis of a casein substrate, 140-150 microM Ca2+ for half-maximal autolysis in the presence of 80 microM phosphatidylinositol, and 190-210 microM Ca2+ for half-maximal autolysis in the absence of phosphatidylinositol. Consequently, mu-calpain is an active proteinase and does not require autolysis for activation. Bovine skeletal muscle m-calpain required 700-740 microM Ca2+ for half-maximal rate of proteolysis of a casein substrate, 370-400 microM Ca2+ for half-maximal autolysis in the presence of 80 microM phosphatidylinositol, and 740-780 microM Ca2+ for half-maximal autolysis in the absence of phosphatidylinositol. These results are consistent with the idea that m-calpain functions in its autolyzed form, but the results do not demonstrate that unautolyzed m-calpain is inactive. 80 microM phosphatidylinositol had no effect on the Ca2+ requirement of the autolyzed forms of either mu- or m-calpain but lowered the specific activity of mu-calpain to 20% of its activity in the absence of phosphatidylinositol. Of the four forms of the calpains, unautolyzed m-calpain, autolyzed m-calpain, and unautolyzed mu-calpain would not be proteolytically active at the free Ca2+ concentrations of 300-1200 nM present inside normal cells, and neither mu- nor m-calpain would undergo autolysis at these Ca2+ concentrations, even in the presence of phosphatidylinositol. Cells must contain a mechanism other than or in addition to membrane association and autolysis to activate the calpains.

Site-directed mutagenesis of colicin E1 provides specific attachment sites for spin labels whose spectra are sensitive to local conformation

Colicin E1 is an E. coli plasmid-encoded water-soluble protein that spontaneously inserts into lipid membranes to form a voltage-gated ion channel. We have employed a novel approach in which site-directed mutagenesis is used to provide highly specific attachment points for nitroxide spin labels. A series of colicin mutants, differing only by the position of a single cysteine residue, were prepared and selectively labeled at that cysteine. A hydrophilic sequence (398-406) within the C-terminal domain of the water-soluble form of the protein was investigated and exhibited an electron paramagnetic resonance (EPR) spectral periodicity strongly suggesting an amphiphilic alpha-helix. After removal of the N-terminus of the protein with trypsin, the spectra for this sequence indicate increased label mobility and a more flexible structure.

Menstrual blood loss, haemoglobin and ferritin concentration of Beijing women wearing steel ring, VCu 200, and TCu 220c IUDs

Menstrual blood loss (MBL), serum ferritin and whole blood cyanmethemoglobin were measured at pre- and 1, 3, 6, 12, 18 and 24th postinsertion cycles in 60 women wearing the Steel Ring, the Copper V (VCu 200) or the Copper T (TCu 220c). The MBL, incidence of menorrhagia and iron deficiency anemia were lower among users of the Steel Ring than among users of the Copper V and T. Anemia occurred later and the duration of menstruation was shorter with the Steel Ring than with the Copper T. There were no statistically significant differences between the Copper V and T.