Isolation of a Bacillus cereus strain HBL-AI and its application for production of Trans-4-hydroxy-l-proline.

A new trans-4-hydroxy-l-proline (trans-Hyp) producing Bacillus cereus HBL-AI, was isolated from the air, which was screened just using l-proline as carbon and energy sources. This strain exhibited 73·4% bioconversion rate from initial l-proline (3 g l-1 ) to trans-Hyp. By sequencing the genome of this bacterium, 6244 coding sequences were obtained. Genome annotation analysis and functional expression were used to identify the proline-4-hydroxylase (BP4H) in HBL-AI. This enzyme belonged to a family of 2-oxoglutarate-related dioxygenases, which required 2-oxoglutarate and O2 as co-substrates for the reaction. Homologous modelling indicated that the enzyme had two monomers and contained conserved motifs, which included a distorted 'jelly roll' ß strand core and the residues (HXDXnH and RXS). The engineering Escherichia coli 3 Δ W3110/pTrc99a-proba-bp4h was constructed using BP4H, which transformed glucose to trans-Hyp in one step with high concentration of 46·2 g l-1 . This strategy provides a green and efficient method for synthesis of trans-Hyp and thus has a great potential in industrial application.

[Strategy and clinical outcome of deceased donor kidney transplantation for presensitized recipients].

Objective: To explore the management strategy and clinical outcome of renal transplantation in presensitized recipients using deceased donor kidneys. Methods: From January 2011 to June 2018, twenty-one presensitized patients, including 8 with positive donor specific antibodies (DSA) and 13 with positive panel-reactive antibodies (PRA) but no DSA, received renal retransplantation from deceased donors in our center. The incidence of delayed graft function (DGF) and acute rejection (AR), changes of DSA, and the graft and patient survival were retrospectively analyzed. Results: None of the renal allografts had primary non-function (PNF) and DGF after transplantation. Four of the 13 recipients with PRA(+)/DSA-had a total of 5 episodes of acute cell-mediated rejection (CMR), while 5 of 8 recipients with pre-existing DSA(+) developed AR, including 3 cases with CMR alone and 2 cases with mixed AR. All episodes of rejection were successfully reversed after targeted treatment. Interestingly, of the 8 recipients with positive preformed DSA, 4 cases with positive DR-DSA and/or class Ⅰ-DSA had their DSA disappeared after transplantation, whereas DQ-DSA remained positive in 4 of 5 recipients. After a median follow-up of 26 months, all recipients maintained normal renal allograft function, and the survival rates of both graft and recipient were 100%. Conclusions: With the use of deceased donors, kidney transplantation can be successfully performed in presensitized patients by appropriate HLA-matching screening, choosing donor kidneys with good quality, and the combination of optimal perioperative treatment.

Left Lobe Auxiliary Liver Transplantation for End-stage Hepatitis B Liver Cirrhosis.

Auxiliary liver transplantation (ALT) for hepatitis B virus (HBV)-related liver cirrhosis previously showed poor results, because the native liver was a significant source of HBV recurrence and the graft could be rapidly destroyed by HBV infection in an immunosuppressive condition. Four patients with HBV-related liver cirrhosis were unable to undergo orthotopic liver transplantation because the only available grafts of left lobe were too small. Under entecavir-based anti-HBV treatment, they underwent ALT in which the recipient left liver was removed and the small left lobe graft was implanted in the corresponding space. The mean graft weight/recipient weight was 0.49% (range, 0.38%-0.55%). One year after transplantation, the graft sizes were increased to 273% and the remnant livers were decreased to 44%. Serum HBV DNA was persistently undetectable. Periodic graft biopsy showed no signs of tissue injury and negative immunostaining for hepatitis B surface antigen and hepatitis B core antigen. After a mean follow-up period of 21 months, all patients live well with normal graft function. Our study suggests that ALT for HBV-related liver cirrhosis is feasible under entecavir-based anti-HBV treatment. Successful application of small left livers in end-stage liver cirrhosis may significantly increase the pool of left liver grafts for adult patients.

Dietary supplementation with glutamine and γ-aminobutyric acid improves growth performance and serum parameters in 22- to 35-day-old broilers exposed to hot environment.

This study was designed using 360 21-day-old chicks to determine the influences of diet supplementation with glutamine (5 g/kg), γ-aminobutyric acid (GABA, 100 mg/kg) or their combinations on performance and serum parameters exposed to cycling high temperatures. From 22 to 35 days, the experimental groups (2 × 2) were subjected to circular heat stress by exposing them to 30-34 °C cycling, while the positive control group was exposed to 23 °C constant. The blood of broilers was collected to detect serum parameters on days 28 and 35. Compared with the positive control group, the cycling high temperature decreased (p < 0.05) the feed consumption, weight gain and serum total protein (TP), glucose, thyroxine (T4), insulin, alkaline phosphatase (ALP), glutamine, GABA and glutamate levels, while increased (p < 0.05) the serum triglyceride (TG), corticosterone (CS), glucagon (GN), creatine kinase (CK), glutamic oxaloacetic transaminase (GOT), nitric oxide synthase (NOS), glutamate pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) levels during 22-35 days. However, dietary glutamine (5 g/kg) increased (p < 0.05) the feed consumption, weight gain and serum levels of glutamine, TP, insulin and ALP, but decreased (p < 0.05) the serum TG, CK, GOT, NOS and GPT levels. Diet supplemented with GABA also increased (p < 0.05) weight gain and the serum levels of TP, T4, ALP, GABA and glutamine. In addition, the significant interactions (p < 0.05) between glutamine and GABA were found in the feed consumption, weight gain and the serum ALP, CK, LDH, GABA, T3 and T4 levels of heat-stressed chickens. This research indicated that dietary glutamine and GABA improved the antistress ability in performance and serum parameters of broilers under hot environment.

The survival and value of liver transplantation for liver carcinoma: a single-center experience.

UNLABELLED: Liver transplantation for liver carcinoma with cirrhosis is a treatment still in dispute. The objectives were to summarize the survival and cost of 50 liver transplant cases performed for liver carcinoma over nearly 3 years. METHODS: We performed 138 liver transplants from January 1999 to February 2002. There were 50 cases (36.2%) of liver carcinoma with HBV cirrhosis, which were divided into three stages based on the tumor pathology: Stage 1 cases showed a single mass (< or = 5 cm), 4 cases; Stage 2, a single mass > 5 cm or intrahepatic multiple masses without PV cancer embolus, 32 cases; and Stage 3: tumor invasion of the PV or perihepatic lymph nodes or organs, 14 cases. All patients received three to six courses of chemotherapy postoperatively. RESULTS: All four cases of stage 1 survived > 1 year; one of them is at 3 years with good liver function and tumor free. The mean half-year medical cost was $27.100 +/- 108 in stage 1. The half-year survival and medical costs were 62.5% and $31,500 +/- 260 in stage 2 and 15.0% and $35,500 +/- 134 in stage 3. CONCLUSION: Liver transplantation is an effective treatment for early-stage liver carcinoma, that achieves good medical and economic results, but should be limited to advanced liver cancer.

Genotoxicity of drinking water from Chao Lake.

Genotoxic activity appears to originate primarily from reactions of chlorine with humic substances in the source waters. Comparisons of extracts of settled versus chlorinated water have confirmed that chlorinating during water treatment produces mutagenic activity in the mutagenicity tests. Present work on XAD-2 extracts of raw, chlorinated (treated), and settled water from the Chao Lake region of China has involved a battery of mutagenicity assays for various genetic endpoints: the Salmonella test, the sister-chromatid exchange (SCE) induction in Chinese hamster lung (CHL) cells, and the micronucleus (MN) induction in the peripheral blood erythrocytes of silver carp. Extracts of raw and treated water but not the settled water are mutagenic in the Salmonella assay. On the other hand, extracts of three water samples show activity in the SCE and MN assays, especially the raw and treated water. These data show that contamination and chlorinating contribute mutagens to drinking water and suggest that the mammalian assays may be more sensitive for detecting mutagenicity in aquatic environment than the Salmonella test.

Analysis of deaths in patients awaiting heart transplantation: impact on patient selection criteria.

OBJECTIVE: To analyse the clinical characteristics of patients who died on the Stanford heart transplant waiting list and to develop a method for risk stratifying status 2 patients (outpatients). METHODS: Data were reviewed from all patients over 18 years, excluding retransplants, who were accepted for heart transplantation over an eight year period from 1986 to 1994. RESULTS: 548 patients were accepted for heart transplantation; 53 died on the waiting list, and 52 survived on the waiting list for over one year. On multivariate analysis only peak oxygen consumption (peak VO2: 11.7 (SD 2.7) v 15.1 (5.2) ml/kg/min, P = 0.02) and cardiac output (3.97 (1.03) v 4.79 (1.06) litres/min, P = 0.04) were found to be independent prognostic risk factors. Peak VO2 and cardiac index (CI) were then analysed in the last 141 consecutive patients accepted for cardiac transplantation. All deaths and 88% of the deteriorations to status 1 on the waiting list occurred in patients with either a CI < 2.0 or a VO2 < 12. In those with a CI < 2.0 and a VO2 < 12, 38% died or deteriorated to status 1 in the first year on the waiting list. Patients with CI > or = 2.0 and a VO2 > or = 12 all survived throughout follow up. Using a Cox's proportional hazards model with CI and peak VO2 as covariates, tables were constructed predicting the chance of surviving for (a) 60 days and (b) 1 year on the waiting list. CONCLUSIONS: These data provide a basis for risk stratification of status 2 patients on the heart transplant waiting list.

Modulation of catecholamine cardiomyopathy by allopurinol.

It has been suggested that cardiac injury by catecholamines may be the result of coronary constriction leading to ischemic damage. Allopurinol (ALLO) has been shown to reduce the extent of myocardial necrosis in various systems. Hence the possibility that ALLO might limit norepinephrine (NE) injury was tested. Rabbit hearts were infused with NE (3 micrograms/min/kg) for 90 minutes, with or without ALLO (50 micrograms/min/kg). Control specimens infused with saline solution plus ALLO were also prepared. Hearts were excised 48 hours later and studied as isovolumic isolated heart preparations. Peak systolic pressure, coronary flow, and myocardial oxygen consumption were significantly reduced in the hearts infused with NE but not in the NE + ALLO hearts. Myocardial adenosine triphosphate and glycogen concentrations were 29% and 26% lower in the NE hearts compared with control hearts. These reductions were absent in the NE + ALLO group. Moreover, rates of creatine phosphokinase and lactic dehydrogenase release were sharply elevated in the NE hearts but not in those also given ALLO. These findings are consistent with the changes observed histologically. The amount of myocardial damage was less in the ALLO + NE group compared with the NE group (p less than 0.02). This appears to be the first report to demonstrate that ALLO reduces myocyte damage by NE. Possible mechanisms include decreased free radical production, scavenging of free radicals, and preservation of the adenine nucleotide pool. Because xanthine oxidase activity is absent in the rabbit, the latter two mechanisms are more likely explanations for the findings.

Catecholamine cardiomyopathy: review and analysis of pathogenetic mechanisms.

Catecholamines given in high concentrations produce myocardial damage in several mammalian species. The histological changes are similar to those found in patients given large amounts of pressor agents and in those who develop pheochromocytomas. They include myofiber necrosis, myofibrillar degeneration, and mononuclear leukocytic infiltration. Cardiac function is significantly impaired. Endogenous release of catecholamines can also induce myocardial injury in rabbits infused with tyramine. Anatomic and functional abnormalities described in various models of catecholamine cardiomyopathy are summarized. The several major theories regarding pathogenesis are reviewed. Recent data suggesting that O2-derived free radical generation is involved are discussed.

[Local injection of bleomycin A5 in lymphangioma in children. Analysis of 100 cases].

From Jan. 1985 to Dec. 1988, 100 newborn and small infants suffering from lymphangioma were treated with bleomycin A5 injecting into lymphangioma. The cases were divided into three types: (1) Bleomycin A5 local injection into the lymphangioma were practiced on 70 cases; (2) Surgical partial resection of lymphangioma plus local injection on 26 cases; (3) A previous excision but recurred postoperatively were 4 cases. The dosage of bleomycin A5 was 10 mg per time. The therapeutic course was not more than 5 times. The efficacy of bleomycin A5 were satisfactory in all cases except only one case with a large lymphangioma of previous palliative excision but recurred. There was not a recurrent patient at following-up from 3 months to 4 years.

Dancing modes and frequency shifts in a phase conjugator.

If the time-reversal symmetry of a ring phase conjugator is broken, the output of the device is no longer the phase conjugate of the input. For a TEM(00) input wave, the output wave can be a higher-order resonator mode, although there is no resonator. Additionally, there will be a frequency shift between the input and output waves that varies discontinuously as the asymmetry in the ring is increased. Experiments using photorefractive BaTiO(3) are in good agreement with theory and demonstrate the ability of the system to choose the combination of output mode and frequency that maximizes the mode gain.