[Association between mild cognitive impairment and all-cause mortality in elderly population in China: a Meta analysis].

Objective: To quantitatively evaluate the association between mild cognitive impairment and all-cause mortality. Methods: The research papers of the association between cognitive impairment and all-cause mortality in the elderly in the databases of PubMed, EMBASE, Wang Fang data and CNKI published as of August 1, 2021 were comprehensively retrieved. Software R 4.02 was used for Meta-analysis. Results: A total of 9 research papers were included, involving 48 709 patients. The quality of included papers was high. The results of Meta-analysis showed that the association between mild cognitive impairment and the increased risk of all-cause mortality was statistically significant. Compared with the normal cognitive population, the risk of mortality in the elderly with mild cognitive impairment increased by 39% (HR=1.39, 95%CI: 1.18-1.63). Conclusions: The current research evidence showed that mild cognitive impairment assessed by MMSE screening scale can be used as an independent predictor of the increased risk of all-cause mortality in the elderly population in China. However, due to the limitation of the number of included studies and sample size, the conclusions need to be supported by more evidence studies.

Protein disulfide isomerase a4 acts as a novel regulator of cancer growth through the procaspase pathway.

Protein disulfide isomerase a4 (PDIA4) is implicated in the growth and death of tumor cells; however, its molecular mechanism and therapeutic potential in cancer are unclear. Here, we found that PDIA4 expression was upregulated in a variety of tumor cell lines and human lung adenocarcinoma tissues. Knockdown and overexpression of PDIA4 in tumor cells showed that PDIA4 facilitated cell growth via the reduction of caspases 3 and 7 activity. Consistently, Lewis lung carcinoma cells overexpressing PDIA4 grew faster than did parental cells in tumor-bearing mice, as shown by a reduced survival rate, increased tumor size and metastasis, and decreased cell death and caspases 3 and 7 activity. PDIA4 knockdown resulted in opposite outcomes. Moreover, results obtained in mice with spontaneous hepatoma indicated that PDIA4 deficiency significantly reduced hepatic tumorigenesis and cyst formation and increased mouse survival, tumor death, and caspases 3 and 7 activity. Mechanistic studies illustrated that PDIA4 negatively regulated tumor cell death by inhibiting degradation and activation of procaspases 3 and 7 via their mutual interaction in a CGHC-dependent manner. Finally, we found that 1,2-dihydroxytrideca-5,7,9,11-tetrayne, a PDIA4 inhibitor, reduced tumor development via enhancement of caspase-mediated cell death in TSA tumor-bearing mice. These findings characterize PDIA4 as a negative regulator of cancer cell apoptosis and suggest that PDIA4 is a potential therapeutic target for cancer.

Sequence and molecular analysis of the rpoA cluster genes from Xanthomonas campestris pv. campestris.

The Xanthomonas campestris rpsM (S13)-rpsK (S11)-rpsD (S4)-rpoA (alpha)-rplQ (L17) cluster, encoding RNA polymerase alpha-subunit and four ribosomal proteins, reside in a 3164-bp DNA region. The N-terminal sequence of the authentic alpha-protein determined chemically matches that predicted from the nucleotide sequence. rplQ is monocistronic, instead of being co-transcribed with the other genes as in Escherichia coli. Antiserum against the His-tagged alpha-protein cross-reacted with the E. coli alpha-protein.

Selection of mutations altering specificity in restriction-modification enzymes using the bacteriophage P22 challenge-phage system.

A method for selecting mutants of site-specific DNA-binding proteins has been applied to the study of the EcoRI and RsrI restriction-modification enzymes. Catalytically inactive variants of both endonucleases are shown to function as pseudo-repressors in the bacteriophage P22 challenge-phage assay, and, upon further mutagenesis of the gene encoding R.EcoRI, a variant of that enzyme has been selected which appears to bind EcoRI-methylated GAATTC sequences to the exclusion of unmethylated sites: this specificity is the opposite of that belonging to the native enzyme. Variants of the EcoRI methylase have also been found that lack either catalytic activity or both binding and catalytic activities.

Hepatic, placental, and fetal trace elements following molybdenum supplementation during gestation.

The effect of dietary Mo (Na2Mo(4)2H2O) added to drinking water at levels of 0, 5, 10, 50, or 100 mg on hepatic (gestating dams), placental, and fetal Mo, Cu, Zn, and Fe contents of Sprague-Dawley rats was studied. These elements were determined by a polarographic catalytic procedure for Mo and by atomic absorption spectrophotometry for Cu, Fe, and Zn. Hepatic Mo increased two to sixfold (5-100 mg Mo). There was a 1.5-fold increase in hepatic Cu, significant only at the 50 to 100 mg Mo/L treatment levels. Although the hepatic Fe content of the gestating rats significantly increased with Mo supplementation, the extent of the increase appeared to be influenced by the litter size, fetal weights, and the degree of fetal resorption. Zinc values did not differ at any of the treatment levels. Placental Mo increased 3-76-fold, Cu one to threefold. No differences were observed in placenta Fe or Zn. Fetal Mo increased two to six-fold (10-100 mg/L) and Cu increased one to fivefold. There were no differences in the Fe and Zn content although both of these elements appeared to decline as the level of supplemental Mo increased. Significant correlations were also observed between hepatic, placental, and fetal Mo, Cu, Fe, and Zn. These results suggest that changes in trace mineral status in gestation, owing to high Mo intake, do occur and such occurrences are also reflected in the fetus.

Clinical experience of esophageal ulcers and esophagitis in AIDS patients.

In Taiwan, numbers of patients with the acquired immunodeficiency syndrome (AIDS) have been increasing in recent years. We present esophageal disease of different causes in 5(16%) heterosexual men among 31 AIDS patients over a 5-year period. Major symptoms included mild dysphagia in 4 (80%) patients and odynophagia in 3 (60%) patients. The duration of symptoms varied from 3 days to 6 months. The symptoms occurred before the diagnosis of AIDS in 3 patients. At esophagogastroduodenoscopy (endoscopy), all 5 patients had esophagitis and/or esophageal ulcers proved by histopathologic evaluation. Four had Candida esophagitis, 3 had cytomegalovirus esophagitis/ulcers and 2 had idiopathic esophageal ulcerations (IEU). Three patients had different esophagitis/ulcers at the same time or during follow-up. The median CD4 lymphocyte count at the time of diagnosis of esophageal disease was 12.2 cells/mm3 (range, 3 to 35 cells/mm3). The endoscopic pictures of the different causes of esophagitis/ ulcers lack uniformity in number, size and appearance. These observations make a conclusion that all AIDS patients with an esophageal disease should undergo endoscopy with biopsy to obtain a definitive diagnosis.

[Treatment of male breast cancer: an analysis of 41 cases].

41 male patients with breast cancer confirmed pathologically were treated. Of these, 35 were treated by radical mastectomy and 6 by modified radical mastectomy. The patients with axillary lymphatic metastasis were treated by postoperative radiotherapy, chemotherapy. The overall 5-, 10- and 15-year survival rates were 67.6%, 53.3% and 55.0%, respectively. The 15 year survival rates of TNM stage I-II and III patients were 55% and 50% respectively. We conclude that radical or modified radical mastectomy is the rational therapy for male breast cancer. The patients in stage III will benefit from postoperative adjuvant therapy in terms of improving prognosis.

Simulation of the contractile response of cells on an array of micro-posts.

A bio-chemo-mechanical model has been used to predict the contractile responses of smooth cells on a bed of micro-posts. Predictions obtained for smooth muscle cells reveal that, by converging onto a single set of parameters, the model captures all of the following responses in a self-consistent manner: (i) the scaling of the force exerted by the cells with the number of posts; (ii) actin distributions within the cells, including the rings of actin around the micro-posts; (iii) the curvature of the cell boundaries between the posts; and (iv) the higher post forces towards the cell periphery. Similar correspondences between predictions and measurements have been demonstrated for fibroblasts and mesenchymal stem cells once the maximum stress exerted by the stress fibre bundles has been recalibrated. Consistent with measurements, the model predicts that the forces exerted by the cells will increase with both increasing post stiffness and cell area (or equivalently, post spacing). In conjunction with previous assessments, these findings suggest that this framework represents an important step towards a complete model for the coupled bio-chemo-mechanical responses of cells.

Salmonella infections in infants and children.

BACKGROUND: Salmonella is an important pathogen for infants and children of which multiply resistant strains were recently reported. Our interest was the annual variation of clinical manifestations, serotype and the sensitivity rate for antibiotics during the past decade. Increased incidence of bacteremia in infants is reported. In order to find the predisposing factors of patients with acute gastroenteritis complicated with bacteremia, we conducted a retrospective analysis. METHODS: We reviewed the records of documented patients who had positive culture for Salmonella in our Pediatric Department from September 1982 to September 1992. Those patients with acute gastroenteritis were divided into two groups: I, those complicated with bacteremia and II, non-bacteremic cases. Then we compared the age, body temperature, severity of clinical symptoms, white blood cell count and Salmonella serotype of these two groups. RESULTS: There were 180 cases of Salmonella infection in our Pediatric Department during the past decade. The mean age was 14.80 months. Most (88.9%) patients were under two years old and 146 subjects were victims of acute gastroenteritis. Six cases had infection of the central nervous system (CNS). Five cases presented typhoid fever. Of three mortal cases, two died from meningitis with sepsis and one was a victim of malignant lymphoma and septic arthritis complicated with sepsis. Salmonella group B was the most common pathogen. There were no cases of typhoid fever after 1989. The sensitivity to ampicillin, chloramphenicol, and ceftriaxone for group B were 25.7%, 26.1% and 100% respectively. Multiply resistant Salmonella species were not present in our cases. The severity of clinical symptoms varied in significantly between those who had acute gastroenteritis with bacteremia (Group I) and those who had acute gastroenteritis without bacteremia (Group II). However, there was a significant distinction in the average age of the two groups (P = 0.005). CONCLUSIONS: Although the annual number of cases did not decrease in recent years, the number of cases of typhoid fever did decrease. Most patients were infants and acute gastroenteritis was most common. In our series, the relative sensitivity for ampicillin, chloramphenicol was small over the past decade. Multiply resistant Salmonella species were not found, which may be due to the small sample size.

Transcription termination directed by heteroduplex thr attenuator templates. Evidence that the transcript stem and loop structure is the termination signal.

We have constructed both homoduplex and heteroduplex restriction fragment templates that contained mutations in the G + C-rich region of dyad symmetry in the Escherichia coli thr operon attenuator and have studied their termination properties in an in vitro transcription system. We found that the DNA sequence of the template strand determines the transcription termination efficiency. We also constructed two double mutant heteroduplex templates to examine the role of possible complementary base pairs between the nontranscribed DNA strand and the nascent RNA in the transcription bubble. There was no indication that the potential DNA-RNA interactions in the G + C-rich region are involved in transcription termination. Taken together, our results are consistent with and extend those obtained by Ryan and Chamberlin (Ryan, T., and Chamberlin, J. (1983) J. Biol. Chem. 258, 4690-4693) for the trp operon attenuator and argue strongly against models that propose that DNA hairpin formation in the nontranscribed DNA strand or pairing of the nascent RNA with the nontranscribed DNA strand are important for transcription termination.

Isolation and footprint analysis of the Escherichia coli thr leader paused transcription complex.

The E. coli thr operon leader region contains a cluster of transcription pause sites upstream of the attenuator. In this report, we determine the exact sites of pausing and analyze the structure of the ternary complex by footprint techniques. Under synchronized transcription initiation conditions in vitro, three closely-spaced transcription pause sites were identified. These pause sites appeared downstream of the first region of dyad symmetry, which encodes an RNA hairpin in the transcript, and occurred at positions G112, G114 and A116 of the thr leader RNA. The results showed that the half-life of the thr paused complexes at G112 and G114 could be enhanced by limiting the concentration of the nucleoside triphosphate GTP in the transcription reactions. In addition, the half-life of the paused complexes was shown to increase in the presence of NusA protein. The thr leader complex that paused immediately before residues G112 and G114 of the nascent transcript was isolated and its structure was analyzed with enzymatic and chemical cleavage reagents. The footprinting studies using DNase I showed that there were approximately 35 nucleotides on both strands of the DNA that were protected by RNA polymerase from DNase I cleavage. The DNA segment protected by RNA polymerase is approximately 19 nucleotides upstream and 14 nucleotides downstream of the pause sites. The results from hydroxyl radical footprints also showed a similar pattern of protection at the transcription pause sites. However, no significant differences in the footprinting patterns were observed in the presence or absence of NusA protein.

Effect of molybdenum supplementation on hepatic trace elements and enzymes of female rats.

The effects of molybdenum (Mo) supplementation in the drinking water at the levels of 0.1, 0.5, 1.0, 2.0, 5.0 and 10.0 mg/l on the hepatic trace element concentrations and enzyme activities of female Sprague-Dawley rats were studied. The mean hepatic Mo concentration increased significantly in the rats supplemented with 0.1 mg Mo/l as compared to the nonsupplemented rats, but a further significant increase did not occur until the supplementation level reached 5-10 mg Mo/l drinking water. Hepatic copper concentration of the group given 0.1 mg Mo/l and hepatic iron content of the groups given 0.1 or 0.5 mg Mo/l were significantly higher than those of the other groups. The hepatic xanthine dehydrogenase/oxidase activity was not significantly affected by Mo supplementation. The hepatic sulfite oxidase (SOX) activity of the group given 0.1 mg Mo/l was significantly higher than that of the nonsupplemented group. The SOX activities of all the other supplemented groups were at a significantly different level intermediate between the first two. The hepatic superoxide dismutase (SOD) activity was significantly higher in the group given 0.1 mg/l than in the other groups. These results indicated that molybdenum enzymes and SOD might not be participants in previously reported anticarcinogenic activity of Mo, as supplementation at the level of 0.1 mg/l had been observed to be inefficacious in inhibiting N-nitrosomethylurea-induced mammary tumor incidence.

Transcription termination at the thr attenuator. Evidence that the adenine residues upstream of the stem and loop structure are not required for termination.

The Escherichia coli thr operon attenuator has a structure similar to other Rho-independent terminators. The DNA sequence immediately 5' to the termination site is dG+dC-rich and contains a region of dyad symmetry that, when transcribed into RNA, encodes a hairpin structure in the transcript. It also contains a stretch of 9 consecutive dA-dT residues immediately distal to the region of dyad symmetry which encode uridine residues at the 3' end of the terminated transcript. In addition, the thr attenuator has a stretch of 6 dA-dT residues immediately upstream of the region of dyad symmetry which encode 6 adenines. These adenines could potentially pair with the distal uridines to form a hairpin structure extended by as much as 6 A-U base pairs. In this report we have examined the role of the upstream adenines in transcription termination. We used templates that specify mismatches or create new base pairs in the potential A-U secondary structure of the transcript as well as templates that delete segments of the A residues upstream of the hairpin. We conclude that A-U pairing is not required for efficient transcription termination at the thr attenuator. This conclusion is likely to apply to other Rho-independent terminators that contain hairpin-proximal dA-dT residues.

Isolation and characterization of the Xanthomonas campestris rpoH gene coding for a 32-kDa heat shock sigma factor.

Degenerate oligonucleotide primers corresponding to the conserved regions of bacterial heat shock sigma factor RpoH (sigma 32) were used to amplify a 190-bp fragment by PCR on the X. campestris pv. campestris strain 11 chromosome. Using this fragment as a probe, plasmid pXC57 carrying a 4.7-kb insert was isolated from a genomic library of Xc11. Sequence analysis of a stretch of 2,053 bp from the pXC57 insert revealed an ORF encoding a polypeptide of 291 aa (32,854 dal) which displays 59.6% and 57.3% identity to the rpoH gene products of E. coli and P. aeruginosa, respectively. The Xc11 rpoH gene was able to complement the RpoH deficient E. coli strain A7448. Both amino acid and mRNA sequences deduced from the Xc11 rpoH gene show structural features characteristics of the corresponding sequences from those of the gamma subgroup proteobacteria. The RpoH levels in Xc11 were demonstrated to increase transiently in response to heat shock treatment by immunoblot analysis using the polyclonal antibody raised against the purified Xc11 RpoH.

Comparative study of long-term effects of surgical excision and excision combined with radiotherapy or chemotherapy in breast cancer: an analysis of 192 cases.

Clinical data of 192 patients with breast cancer with a primary lesion of 2-5 cm (stage II according to the criteria recommended by the UICC) and with histopathologically confirmed positive axillary lymph nodes were analyzed. The patients were divided into three groups: 1) surgical excision alone; 2) surgery plus irradiation; and 3) surgery plus chemotherapy. It was shown that the 5-year survival rates for these groups were 40.5%, 61.0%, and 62.0%, respectively (P less than .05).