The FabA-FabB Pathway Is Not Essential for Unsaturated Fatty Acid Synthesis but Modulates Diffusible Signal Factor Synthesis in Xanthomonas campestris pv. campestris.

Most bacteria use type II fatty acid synthesis (FAS) systems for synthesizing fatty acids, of which the conserved FabA-FabB pathway is considered to be crucial for unsaturated fatty acid (UFA) synthesis in gram-negative bacteria. Xanthomonas campestris pv. campestris, the phytopathogen of black rot disease in crucifers, produces higher quantities of UFAs under low-temperature conditions for increasing membrane fluidity. The fabA and fabB genes were identified in the X. campestris pv. campestris genome by BLAST analysis; however, the growth of the X. campestris pv. campestris fabA and fabB deletion mutants was comparable to that of the wild-type strain in nutrient and minimal media. The X. campestris pv. campestris ΔfabA and ΔfabB strains produced large quantities of UFAs and, altogether, these results indicated that the FabA-FabB pathway is not essential for growth or UFA synthesis in X. campestris pv. campestris. We also observed that the expression of X. campestris pv. campestris fabA and fabB restored the growth of the temperature-sensitive Escherichia coli fabA and fabB mutants CL104 and CY242, respectively, under non-permissive conditions. The in-vitro assays demonstrated that the FabA and FabB proteins of X. campestris pv. campestris catalyzed FAS. Our study also demonstrated that the production of diffusible signal factor family signals that mediate quorum sensing was higher in the X. campestris pv. campestris ΔfabA and ΔfabB strains and greatly reduced in the complementary strains, which exhibited reduced swimming motility and attenuated host-plant pathogenicity. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

[CH4 Fluxes During the Algal Bloom in the Pengxi River].

Emissions of greenhouse gases in the Three Gorges Reservoir have been attracting attention in the recent years. This study was conducted to reveal the CH4 emission and removal during the process of algal growth at different nitrogen and phosphorus concentrations in the Pengxi River in the Three Gorges Reservoir. In-situ field experiments were conducted in the Gaoyang Lake in Pengxi River. From April 22nd, 2016, to May 9th, 2016, different concentrations of nitrogen and phosphorus were added to different experimental chambers. Results showed that CH4 emission decreased sharply from the first day of the experiment to the sixth day, and after that, CH4 emission in the water samples with only added phosphorus were obviously recovered compared to the other treatment. In this experiment, algal biomass was influenced by different concentrations of N and P. The biomass of algae were not affected by N, but were promoted under suitable concentration of P, such as 1P, 10P, 1NP, and 10NP. When the P concentration was too high, the biomass of algae was also limited. The emission and removal of CH4 in the experiment were significantly related to the addition of NO3--N.

Cut-off Values of Diagnostic Indices to Detect Iron Deficiency in Chinese Breast-fed Infants.

Iron deficiency anemia is one of the most prevalent nutritional deficiency worldwide. The commonly used cut-off values for identifying iron deficiency are extrapolated from older children and may not be suitable for infants. Therefore, our study aimed to establish appropriate cut-off values for the evaluation of iron status in Chinese infants. Pregnant women who delivered at ⋝37 gestational weeks with normal iron status were recruited. Later, infants with normal birth weight and who were breastfed in the first 4 months were selected. Blood samples were collected to assess hemoglobin, serum ferritin, soluble transferrin receptor, mean corpuscular volume and free erythrocyte protoporphyrin. Cut-offs of all iron indices were determined as the limit of 95% confidence interval.

Reconstruction of complex orbital fracture with titanium implants.

AIM: To evaluate the effectiveness and safety of complex orbital fracture reconstruction with titanium implants. METHODS: A retrospective review of 46 patients treated with complex orbital fractures reconstruction using titanium implants from January 2005 to December 2008 was conducted. The following data were recorded: age, gender, mechanism of injury, preoperative and postoperative orbital CT, visual acuity, diplopia, ocular motility and Hertel exophthalmometer. RESULTS: The most common cause was motor vehicle accident (47.8%), followed by industrial injury (30.4%). All patients had improved appearance after operation and CT scan at one week after operation showed the fracture defects of orbit and neighboring areas had been reconstructed. Forty-six cases had various degrees of enophthalmos before operation. Among them, 32 cases were completely corrected, 11 cases improved obviously and 3 cases had no improvement after operation. Thirty-six patients with visual acuity ≥20/60 revealed diplopia of various degrees, including 26 patients had diplopia in right ahead and/or reading positions. At the sixth month after operation, diplopia disappeared in five patients, 7 patients still had diplopia in right ahead and/or reading positions, 14 patients had diplopia in positions rather than right ahead and reading positions (<20°) and ten patients had diplopia only at peripheral gazing (>20°). All patients had various degrees of ocular motility disorders before operation. At the sixth month after operation, eyeball movement disorder disappeared in 9 patients, 31 patients showed improvement and 6 patients had no improvement. Complications of implant infection, rejection and displacement were not reported after operation. CONCLUSION: The application of titanium implants in the repair of complex orbital fractures greatly improves the appearance and functional results, which is a favorable material for plastic surgery of complex orbital fracture.

[Effect of impaired glucose tolerance during pregnancy on newborns].

OBJECTIVE: Abnormal glucose metabolism during pregnancy can result in significant adverse outcomes for newborns. This study was designed to investigate the effect of different degrees of impaired glucose tolerance on newborns. METHODS: Glucose challenge test (GCT) and oral glucose tolerance test (OGTT) were performed in pregnant women at 24-28 weeks of gestation. Based on the results of the two tests, their newborn infants were classified into five groups: gestational diabetes mellitus (GDM, n=182), gestational impaired oral glucose tolerance [GIGT, subdividing into GIGT 1 h (n=57) and GIGT 2-3 h groups (n=156)based on the occurrence time of abnormal blood glucose after glucose load], GCT abnormal but OGTT normal (only GCT abnormal, n=38) and normal glucose tolerance (control, n=1 025). The perinatal outcomes were compared among the five groups. RESULTS: The incidences of macrosomia, large for gestational age (LGA), small for gestational age (SGA), neonatal hypoglycemia and premature birth in the GIGT (1 h) group were significantly higher than those in the control group, but similar to those in the GDM group. The incidences of macrosomia, SGA, neonatal hypoglycemia and premature birth in the GIGT (2-3 h) and the only GCT abnormal groups significantly decreased as compared with those in the GDM group, and similar to those in the control group. GIGT (1 h ) group showed higher incidence of neonatal hypoglycemia and premature birth than the GIGT (2-3 h) and the only GCT abnormal groups. CONCLUSIONS: Different degrees of maternal impaired glucose tolerance have different effects on newborns. As maternal GDM, maternal GIGT (1 h) may increase the risk of macrosomia, LGA, SGA, neonatal hypoglycemia and premature birth.

[Transcranial operation for cranio-orbital communicating tumors and its complications].

OBJECTIVE: To investigate the procedure of transcranial operation via pterional approach for cranio-orbital communicating tumors, to improve surgery skills, to summarize the incidence of main complications and to discuss tips for avoiding damage of the normal orbital tissues. METHODS: Pterional approach was adopted for the operation. After the medial orbital wall or lateral orbital wall was bitten with rongeur and the orbital roof was removed, the extraocular muscles at orbital apex were separated and protected. The head of condenser was used to freeze the tumor, and the tissue around the tumor was separated until the tumor was extirpated. In cases where the tumor penetrated the dura mater and invaded the brain, surgery was performed by neurosurgeons. RESULTS: In 37 cases, 32 cases undertook total resection of tumors and palliative resection was performed in 5 cases due to severe tumor invasion of the cavernous sinus or sphenoid sinus. Of the 37 cases, 28 cases were benign tumors and accounted for 75.67% of total cases (28/37); 9 were malignant tumors and accounted for 24.32% (9/37). Pathological examination showed that 11 cases were meningioma which was the most common type of tumor and accounted for 29.73% of total cases(11/37). The most common complication was injury to extraocular muscles, which occurred in 21 cases and accounted for 56.76% of all cases (21/37). The most serious complication was vision loss, which occurred in 4 cases and accounted for 10.81% of all cases (4/37). CONCLUSIONS: Resection of cranio-orbital communicating tumors via pterional approach provides a wide observation field and facilities exposing tumors. Protecting important tissues in posterior orbital region will result in less postoperative complications.

[Microsurgical treatment for craniopharyngioma combined transorbital-subfrontal and temporal craniotomy].

OBJECTIVE: To summarize the experience in microsurgical removal of craniopharyngioma using combined transorbital-subfrontal and temporal craniotomy. METHODS: Eighteen patients with craniopharyngioma varied from 3.1 cm to 6.2 cm in diameter. The tumor was located in the suprasellar region in 7 patients, extended to the third ventricle in 6, and down to the intrasellar from the suprasellar region in 4, and in the third ventricle in 1. Complete or partial cystic tumor was seen in 13 patients, and solid tumor in 5, and calcified tumor in 12. All the patients were operated on via combined transorbital subfrontal and temporal approach. The tumor was dissected in the spaces I, II and IV with great attention to the preservation of the perforating arteries from the carotid, posterior communication and anterior choroidal arteries to the structure of the hypothalamus. The solid portion of the tumor was removed by piecemeal. RESULTS: The tumor was totally removed in 14 patients and subtotally in 4. Postoperation, follow-up for 8 to 41 months showed no change in 3 residual tumors and one lost to follow-up. All patients Postoperative Karnofsky scales showed 80 - 90, in 12 patients, 60 - 70 in 5 patients, and 50 in 1. CONCLUSIONS: Combined transorbital-subfrontal and temporal approach can provide an excellent exposure to the sellar region, craniopharyngioma and its surrounding structures. This approach ensures less cerebral retraction for easy access to craniopharyngioma, including other large neoplasm of the middle cranial base with ventricle or posterior cranial base extension. Microsurgical techniques play an important role in removing tumor and preserving hypothalamic function.

[Keyhole microsurgery for acoustic neurinomas through suboccipital retrosigmoid sinus approach].

BACKGROUND AND OBJECTIVE: Acoustic neurinomas is one of the most common benign tumor in central nervous system, the main treatment is surgical resection. This study is to explore keyhole surgery with suboccipital retrosigmoid sinus approach for acoustic tumor resection and discuss how to improve the surgical skill and effect. METHODS: Thirteen cases of acoustic neurinomas from Sept. 2000 to Dec. 2001 in our department were operated using keyhole craniotomy technique through unilateral modified suboccipital retrosigmoid approach with "[symbol: see text]" incision. All patient underwent suboccipital craniotomy in order to maintain anatomical replacement, and the tumors (2.0-4.4 cm in diameter) were removed under microscope. RESULTS: Tumors were completed resected in 11 cases, subtotally removed in 2 cases. Eleven patients had obtained anatomic preservation of the facial nerves. Complete follow-up information was obtained in all patients for a period of 3-15 months after operation. House-Brackmann Score in 8 case were Grade I-II, 4 cases Grade III-IV, one case Grade V. Grades I and II facial nerve function were maintained in 61.5% of cases, measurable hearing was preserved in 53.8% of cases(7 cases), and 38.5% of cases maintained serviceable hearing. No severe permanent operative complications were found and no surgical mortality occurred. CONCLUSIONS: Microsurgery with keyhole craniotomy is a safe and effective method for treatment of patients with small and medium-size acoustic neuromas. The advantages of keyhole suboccipital craniotomy are anatomical replacement, less postoperative complications, and beneficial to patient's mental health.