Trans-translation ensures timely initiation of DNA replication and DnaA synthesis in Escherichia coli.

The trans-translation pathway, mediated by the transfer messenger RNA (tmRNA; encoded by the ssrA gene) and the SmpB protein (tmRNA-binding protein expressed in Salmonella enterica), which is conserved in bacteria, is required for various cellular processes. A previous study has shown that trans-translation is required to ensure timely (non-delayed) dnaA transcription and consequent initiation of DNA replication in Caulobacter crescentus. In this study, we observed that initiation of chromosome replication was delayed in Escherichia coli lacking the smpB and/or ssrA genes (DssrA, DsmpB, or DsmpBDssrA mutants). We observed that the growth rate of the mutant cells was much slower than that of its wild-type counterpart. However, the delayed initiation of replication and slower growth in the DssrA or DsmpB mutants were reversed by ectopic expression of tmRNA or SmpB. A synchronized DsmpBDssrA cell culture containing the dnaC2 mutant allele showed delayed protein (total and DnaA) accumulation per cell; DnaA accumulation was also delayed in the DsmpB. These results indicated that absence of trans-translation leads to a delay in initiation of DNA replication, synthesis of total protein (including DnaA), and a decrease in E. coli growth rate. In summary, we propose that the trans-translation pathway is required to ensure timely initiation of replication, protein synthesis, and subsequent cell cycle progression.

Dynamics and regulation of glycolysis-tricarboxylic acid metabolism in the midgut of Spodoptera litura during metamorphosis.

Significant changes usually take place in the internal metabolism of insects during metamorphosis. The glycolysis-tricarboxylic acid (glycolysis-TCA) pathway is important for energy metabolism. To elucidate its dynamics, the mRNA levels of genes involved in this pathway were examined in the midgut of Spodoptera litura during metamorphosis, and the pyruvate content was quantified. The expression patterns of these genes in response to starvation were examined, and the interaction between protein phosphatase 1 (PP1) and phosphofructokinase (PFK) was studied. The results revealed that the expression or activities of most glycolytic enzymes was down-regulated in prepupae and then recovered in some degree in pupae, and all TCA-related genes were remarkably suppressed in both the prepupae and pupae. Pyruvate was enriched in the pupal midgut. Taken together, these results suggest that insects decrease both glycolysis and TCA in prepupae to save energy and then up-regulate glycolysis but down-regulate TCA in pupae to increase the supply of intermediates for construction of new organs. The expression of all these genes were down-regulated by starvation, indicating that non-feeding during metamorphosis may be a regulator of glycolysis-TCA pathway in the midgut. Importantly, interaction between PP1 and PFK was identified and is suggested to be involved in the regulation of glycolysis.

Preoperative predictors of microvascular invasion in multinodular hepatocellular carcinoma.

BACKGROUND: The preoperative predictors of microvascular invasion (MVI) in multinodular hepatocellular carcinoma (HCC) are currently unclear. METHODS: We retrospectively analyzed 266 patients who underwent potentially curative resection of multinodular HCC. MVI was diagnosed on pathological examination in 64 patients. Preoperative risk factors for MVI were identified and survival curves were analyzed. RESULTS: Patients with MVI had significantly lower overall and recurrence-free survival rates than those without MVI (overall survival, 1 year: 86% vs. 71%, 3 years: 58% vs. 16%; recurrence-free survival, 1 year: 69% vs. 12%; 3 years: 48% vs. 12%; both P < 0.001). Multivariate analysis showed that serum alpha-fetoprotein (AFP) level >400 µg/L (odds ratio [OR] = 3.732, P = 0.016), serum gamma-glutamyltransferase (GGT) level >130 U/L (OR = 19.779, P < 0.001), total tumor diameter >8 cm (OR = 5.545, P = 0.010), and tumor number >3 (OR = 11.566, P = 0.007) were independent predictors of MVI. A scoring system was constructed, and the MVI rate was significantly higher in patients with a score of ≥3 than those with a score of <3 (64.1% vs. 10.9%, P < 0.001). Overall and recurrence-free survival rates were significantly lower in patients with a score of ≥3 (both P < 0.001). CONCLUSIONS: Serum AFP level >400 µg/L, serum GGT level >130 U/L, total tumor diameter >8 cm, and tumor number >3 were preoperative predictors of MVI in patients with multinodular HCC. In patients with a high risk of MVI and well-preserved liver function, anatomic resection may be worth considering.

[Study on quality of sleep and mental health in patients with hyperthyroidism].

Sleep quality and psychical health were investigated with Pittsburgh Sleeping Quality Index (PSQI) and SCL-90 in 128 patients with hyperthyroidism. The results showed that: 1. The PSQI scores of the patients with ages over 35 years old were higher than that less than 35 years old (P < 0.05). 2. Sleep problems occurred in 87.55% of the patients. Sleep quality of 9.38% of patients were worse. The sleep quality of the female patients were better than the male (P < 0.05). 3. Apart from interpersonal sensitivity, paranoid ideation and psychoticism, scores of the rest were higher than the general people (P < 0.05). 10.2% of the patients with hyperthyroidism had psychical problems. 4. Apart from sleep time and using sleep pill, there was a high correlation between the scores of SCL-90 and PSQI (P < 0.05-P < 0.001). The results showed that sleep problems of the patients with hyperthyroidism affected their psychical health. Lower sleep quality was a main dangerous factor which affected psychical health of the patients with hyperthyroidism.

[Urinary tract infections in patients with diabetes mellitus and related factors].

We investigated the results of urine culture between the mid-urine and the bladder puncture urine in 30 cases of diabetes millitus. The results showed that female elderly NIDDM and the patients with diabetic retionopathy, nephropathy and neuropathy had higher incidence of urinary infections. When the leukocyte count in routine urine examination was more than 10 increases/HP, the incidence of urinary infection was higher. The urine culture with bladder puncture was more reliable than midurine. In addition, the nuring care for prevention of the urinary infection in diabetes was dicussed.

[Quality of life of the patients with diabetes mellitus and risk factors ].

Quality of life is a comprehensive index for judging individual's physiological, psychological and social function and living condition. There were 143 patients with diabetes mellitus, based on WHO diagnosis standard, hospitalized' in PLA general hospital participated in the study. Investigation instrument included 156 questions (3 aspects) in total. The content of quality of life consisted of 14 items, covering physiological, psychological, social function and living conditions. The results showed that many abnormal changes of quality of life were found in the patients with diabetes mellitus. AMong them the impaired memory and concentration were most obvious. And less important changes were abnormal emotional reactions, reducing of entertainment activities, social adaptation and work ability. The age, degree of education, condition of the illness, complications, social and family background had effects on the quality of life.

[Study on prevention of untoward reaction of glucose tolerance test].

The prevention methods of the side effects of 75g glucose tolerance test were studied. The results showed that the speed of taking glucose water was 3-5 minutes; the water temperature was 20-30 degrees C; water volume of dissolving glucose was 300ml; 0.25g citric acid was added, the side effects will be avoided or reduced.

[Study of causes of untoward reactions of the glucose tolerance test].

The observation of the Side-effects and influent factores after 75g OGTT indioated that the aotal rate of side-effects was 52.43%. After OGTT the commonest side-effect was vomiting. Others were dizzy and palpitation. The side-effects were also related to age, sex, starvation, speed of taking glucose water, water volum of dissolving glucose, gastrointestinal diseases, blood glucose level, etc. It was recommended in this paper that the speed of taking glucose water should be 3-5 minutes, the water temperature below 40 degrees C and starvation about 14 hours.

Effect of lymph composition on an in vitro preparation of the alligator lizard cochlea.

The effects of different artificial lymphs on the cochlear duct of the alligator lizard were studied in an in vitro preparation. The duct was dissected and cemented to the glass floor of a chamber that had been filled with an artificial lymph. The vestibular membrane was removed and latex beads (1-5 microns in diameter) were allowed to settle on the endolymphatic surface of the duct. During perfusion with an artificial lymph solution, the positions of beads were measured and video images of the duct were obtained. Artificial lymphs were isosmotic and included artificial endolymph (AE), artificial perilymph (AP), Leibovitz's L-15 culture medium, an AE solution whose calcium concentration was the same as that of AP, and AE and AP solutions in which gluconate was substituted for chloride ions. Results obtained in AE were consistently different from those in other lymphs. The displacements of beads, the projected area of the papilla, the occurrence of blebs, and direct observation of cells in the duct all indicated that the tissue swelled in AE (with or without 2 mmol/l Ca) but showed no consistent shrinking or swelling in any of the other artificial lymphs. Thus for the solutions we used, the presence of both potassium and chloride was required to elicit the swelling response to isosmotic artificial lymphs. There were some regional differences in the swelling response: the swelling of the endolymphatic surface of the tissue in a direction orthogonal to the basilar membrane surface was smaller on the free-standing region of the basilar papilla than either on the tectorial membrane or on the hyaline epithelial cells. The preparation was osmotically stable in AP and in both AE and AP solutions in which gluconate was substituted for chloride ions. After exposure to these solutions for as much as 300 min, the preparation showed no gross signs of deterioration visible with the light microscope, and continued to exhibit a highly specific osmotic response to the composition of the bathing medium.