[Application value of artificial intelligence in surgical precision diagnosis and treatment of rectal cancer].

Colorectal cancer is the most common malignant tumor of digestive tract, and the incidence of colorectal cancer in China is especially characterized by middle and low rectal cancer. In recent years, with the progress of computer science, artificial intelligence technology has developed rapidly, and has achieved a lot of application results in the medical field. At present, artificial intelligence technology has covered various stages of colorectal cancer, including screening, individualized assessment, auxiliary diagnosis and treatment decision-making, refined surgery and prognosis judgment, providing help for the accurate and individualized treatment of rectal cancer. However, the lack of standardized, systematic, and scalable AI models remains a major pain point for the field. Therefore, it is necessary to carry out large-scale prospective clinical studies on artificial intelligence model to further confirm its application value in the clinical diagnosis and treatment of rectal cancer.

[The value of minimal residual disease and IKZF1 deletion for predicting prognosis in adult patients with B-cell acute lymphoblastic leukemia].

Objective: To reassess the prognostic value of minimal residual disease (MRD) and IKZF1 gene deletions in adults with B-cell acute lymphoblastic leukemia (B-ALL) who received pediatric-specific chemotherapy regimens during the Nanfang Hospital PDT-ALL-2016 trial. Methods: We retrospectively analyzed the prognosis of 149 adult patients with B-ALL who were admitted to Nanfang Hospital from January 2016 to September 2020. Prognostic factors were identified using Cox regression models. Results: The complete remission rate was 93.2% in 149 patients, with a 5-year overall survival (OS) rate of (54.3±5.0) % and a cumulative incidence of relapse (CIR) of (47.5±5.2) %. The Cox regression analysis revealed that MRD positivity at day 45 (MRD(3)) after induction therapy was independently associated with relapse risk (HR=2.535, 95%CI 1.122-5.728, P=0.025). Deletion of IKZF1 gene was independently associated with mortality risk (HR=1.869, 95%CI 1.034-3.379, P=0.039). Based on MRD(3) and IKZF1 gene status, we categorized adult patients with B-ALL into the low-risk (MRD(3)-negative and IKZF1 gene deletion-negative) and high-risk (MRD(3)-positive and/or IKZF1 gene wild type) groups. The 5-year OS and CIR rates were (45.5±6.0) % vs (69.4±8.6) % (P<0.001) and (61.6±8.3) % vs (25.5±6.5) % (P<0.001), respectively, in the high-risk and low-risk groups, respectively. The multivariate analysis showed that the high-risk group was an independent risk factor for OS (HR=3.937, 95%CI 1.975-7.850, P<0.001) and CIR (HR=4.037, 95%CI 2.095-7.778, P<0.001) . Conclusion: The combined use of MRD and IKZF1 gene in prognostic stratification can improve clinical outcome prediction in adult patients with B-ALL, helping to guide their treatment.

Serum fibroblast growth factor-2 levels complement vital biomarkers for diagnosing heart failure.

BACKGROUND: Early diagnosis of atrial fibrillation is important as it is crucial for improving patient outcomes. Fibroblast growth factor-2 (FGF2) may serve as a diagnostic biomarker for heart failure due to its ability to promote cardiac fibrosis and hypertrophy; however, the relationship between FGF2 concentration and heart failure is unclear. Therefore, this study aimed to explore whether FGF2 could aid in distinguishing patients with heart failure from healthy controls and those with dyspnea without heart failure. Additionally, to evaluate the possible correlation between serum FGF2 levels and its diagnostic parameters in patients with heart failure. METHODS: Plasma FGF2 concentration was measured in 114 patients with a complaint of dyspnea (enrolled in the study between January 2022 and August 2022). Based on heart failure diagnosis, the patients were assigned to three groups, as follows: heart failure (n = 80), non-heart-failure dyspnea (n = 34), and healthy controls (n = 36), following physical examination. Possible correlations between serum FGF2 levels and other prognostic parameters in patients with heart failure were analyzed. RESULTS: Serum FGF2 levels were higher in patients with heart failure (125.60 [88.95, 183.40] pg/mL) than in those with non-heart-failure dyspnea (65.30 [28.85, 78.95] pg/mL) and healthy controls (78.90 [60.80, 87.20] pg/mL) (p < 0.001). Receiver operating characteristic curve analysis identified FGF2 concentration as a significant predictor in heart failure diagnosis, with an area under the curve of 0.8693 (p < 0.0001). Importantly, in the heart failure group, serum FGF2 concentrations correlated with key prognostic parameters for heart failure, such as reduced left ventricular ejection fraction and elevated serum levels of N-terminal pro-B-type natriuretic peptide. CONCLUSIONS: Elevated serum FGF2 level is strongly associated with an increased risk of heart failure and could serve as a useful biomarker to complement vital diagnostic parameters for heart failure.

[Preliminary analysis of the promotion effect of laparoscopic standardized surgical treatment for gastric cancer in regional medical centers in Shanghai].

Objective: To explore the promotion effect of laparoscopic standardized surgery for gastric cancer observational in some regional medical centers in Shanghai. Methods: A retrospective cohort study was carried out. Eleven regional medical centers in Shanghai received the promotion program of laparoscopic standardized surgery for gastric cancer, which was led by Ruijin Hospital, Shanghai Jiaotong University School of Medicine (Shanghai Minimally Invasive Surgery Center) from January to December 2020. Clinicopathological data of gastric cancer patients treated at these 11 regional medical centers before and after the promotion program were collected. Inclusion criteria were as follows: patients undergoing laparoscopic distal gastrectomy or total gastrectomy; gastric cancer confirmed by pathology; without distant metastasis or peritoneal metastasis. Patients who did not undergo laparoscopic D2 radical resection, or received neoadjuvant chemotherapy before surgery, or without complete clinical data were excluded. Patients undergoing laparoscopic surgery from January to December 2019 were included in the pre-promotion group (46 cases). Patients undergoing laparoscopic surgery from January to December 2021 were included in the post-promotion group (102 cases). In addition, patients undergoing laparoscopic surgery at Ruijin Hospital from January 2021 to December were included in the control group (138 cases). The baseline data, perioperative measurements postoperative complications, and pathological results of the three groups were analyzed and compared. Results: There were no significant differences in baseline characteristics among the three groups (all P>0.05). Compared with the pre-promotion group, the operation time in post-promotion group was significantly shorter [(207.3±36.0) minutes vs. (254.2±47.1) minutes, t=7.038,P<0.001], and the number of harvested lymph node was significantly more (24.4±12.2 vs. 18.9±5.5, t=2.900, P=0.004). However, there were no significant differences in the extent of resection, time to fluid intake, and postoperative hospital stay between the two groups (all P>0.05). Compared with the control group, the operation time [(207.3±36.0) minutes vs (172.6±26.0) minutes, t=8.281, P<0.001], time to fluid intake [(6.3±3.2) days than (5.5±3.0) days, t=2.029, P=0.044], and the postoperative hospital stay [(14.3±5.6) days vs. (10.1±4.8) days, t=6.036, P<0.001] in the post- promotion group were still longer. Total gastrectomy was less common in the post-promotion group compared with the control group [18 cases (17.6%) vs. 41 cases (29.7%), χ2=7.380, P=0.007]. However, there was no significant difference in the number of harvested lymph node between the two groups (P>0.05). The morbidity of postoperative complication in the post-promotion group (9.8%, 10/102) was significantly lower than that in the pre-promotion group (23.9%, 11/46) (χ2=5.183, P=0.023), while above morbidity was not significantly different between the post-promotion group and the control group [9.8% vs. 6.5% (9/138), χ2=0.867, P=0.352]. Conclusion: After the promotion of laparoscopic standardized surgery for gastric cancer in regional medical centers, the standardization degree of surgery has been improved, and the morbidity of postoperative complication decreases. Laparoscopic standardized surgery for gastric cancer can be promoted to more regional medical centers.

[Prognostic significance of IKZF1 gene deletions in patients with B-cell acute lymphoblastic leukemia].

Objective: This study aimed to investigate the prognostic significance of IKZF1 gene deletion in patients with acute B lymphoblastic leukemia (B-ALL) . Methods: The clinical data of 142 patients with B-ALL diagnosed in Nanfang Hospital between March 2016 and September 2019 were analyzed. Results: IKZF1 deletion was found in 36.0% of the 142 patients with B-ALL, whereas exon 4-7 deletion was found in 44.0% . White blood cell counts were higher in patients with the IKZF1 deletion (52.0% and 28.3% , P=0.005) ; these patients also experienced worse effects of mid-term induction therapy (40.0% and 70.7% , P<0.001) and had a higher proportion of Philadelphia chromosome-positive (52.0% and 21.7% , respectively, P<0.001) . Univariate analysis revealed that the 3-year overall survival rate (OS) and event-free survival rate (EFS) in the IKZF1 deletion group were significantly lower than the IKZF1 wild-type group [ (37.1±7.3) % vs (54.7±5.4) % , (51.8±7.9) % vs (73.9±4.7) % ; P=0.025, 0.013, respectively]. Multivariable analysis showed that harboring IKZF1 deletion was an adverse factor of EFS and OS (HR=1.744, 2.036; P=0.022, 0.020, respectively) . Furthermore, the IKZF1 deletion/chemotherapy group had significantly lower 3-year OS, EFS, and disease-free survival rates than other subgroups. In the IKZF1 deletion cohort, allo-hematopoietic stem cell transplantation (HSCT) significantly improved OS and EFS compared to non-allo-HSCT[ (67.9±10.4) % vs (31.9±11.0) % , (46.6±10.5) % vs (26.7±9.7) % ; P=0.005, 0.026, respectively]. Conclusion: Pediatric-inspired chemotherapy was unable to completely reverse the negative effect of IKZF1 deletion on prognosis. Pediatric-inspired regimen therapy combined with allo-HSCT, in contrast, significantly improved the overall prognosis of IKZF1 deletion B-ALL.

[Risk factors of newly developed nonalcoholic fatty liver disease after pancreaticoduodenectomy].

Objective: To identify the risk factors of newly developed nonalcoholic fatty liver disease(NAFLD) after pancreaticoduodenectomy(PD). Methods: The clinical data of 130 patients who had undergone PD at Department of Hepatopancreatobiliary Surgery, Nanjing Drum Tower Hospital, the Affiliated Hospital of Medical School of Nanjing University from June 2018 to December 2020 were collected retrospectively. There were 74 males and 56 females, with age(M(IQR)) of 62(16) years (range: 22 to 84 years). Twenty-nine patients who developed NAFLD were divided into NAFLD group and 101 patients who did not suffer NAFLD were divided into no NAFLD group. Observation indications included:(1)preoperative demographics,intraoperative and postoperative characteristics; (2)the risk factors of newly developed NAFLD after PD. Count data were analyzed using χ2 test or Fisher's exact test. Measurement data were analyzed by student t test or Mann-Whitney U test. Multivariate analysis was performed using Logistic regression model with a stepwise forward approach. Results: All 130 patients successfully underwent PD and 29 cases(22.3%) developed NAFLD in 6 months after PD. The results of univariate analysis showed that gender,diabetic mellitus,the level of triglyceride preoperatively,and pancreatic ductal adenocarcinoma were the related factors of the development of NAFLD after PD(t=-2.655, χ²=4.563,U=-2.192,χ²=7.044;all P<0.05).Multivariate analysis revealed that gender,body mass index and pancreatic ductal adenocarcinoma were independent risk factors for the development of NAFLD after PD(OR=2.849,1.214,4.165,all P<0.05). Conclusion: Gender, body mass index and pancreatic ductal adenocarcinoma were independent risk factors for the development of NAFLD after PD.

[Laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis].

Objective: To investigate the clinical value of laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis. Methods: From January 2019 to June 2019, the clinical data of 6 patients diagnosed as gastric cancer with peritoneal metastasis were retrospectively analyzed in the Gastrointestinal Surgery Department of Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine. Five were male and 1 was female. The median age was 69.5 (28-77) years. The median body mass index (BMI) was 22.8 (19.6-23.5). All procedures were performed under general anesthesia with endotracheal intubation. The patient's body position and facility layout in the operating room were consistent with those of laparoscopic gastrectomy. The operator's position: the main surgeon was located on the right side of the patient, the first assistant stood on the left side of the patient, and the scopist stood between the patient's legs. Surgical procedure: (1) trocar location: three abdominal trocars was adopted, with one 12 mm umbilical port for the 30° laparoscope (point A). Location of the other two trocars was dependent on the procedure of exploration or biopsy as well as the two polyester cuff position of the peritoneal dialysis catheter: Usually one 5 mm port in the anterior midline 5 cm inferior to the umbilicus point was selected as point B to ensure that the distal end of the catheter could reach the Douglas pouch. The other 5 mm port was located in the right lower quadrant lateral to the umbilicus to establish the subcutaneous tunnel tract, and the proximal cuff was situated 2 cm away from the desired exit site (point C).(2) exploration of the abdominal cavity: a 30° laparoscope was inserted from 12 mm trocar below the umbilicus to explore the entire peritoneal cavity. The uterus and adnexa should be explored additionally for women. Once peritoneal metastasis was investigated and identified, primary laparoscopic peritoneal dialysis catheter implantation was performed so as to facilitate subsequent peritoneal chemotherapy. Ascites were collected for cytology in patients with ascites. (3) peritoneal dialysis catheter placement: the peritoneal dialysis catheter was introduced into the abdominal cavity from point A. Under the direct vision of laparoscopy, 2-0 absorbable ligature was reserved at the expected fixation point of the proximal cuff (point B) for the final knot closure. Non-traumatic graspers were used to pull the distal cuff of peritoneal dialysis catheter out of the abdominal cavity through point B. The 5-mm trocar was removed simultaneously, and the distal cuff was fixed between bilateral rectus sheaths at the anterior midline port site preperitoneally. To prevent subsequent ascites and chemotherapy fluid extravasation, the reserved crocheted wire was knotted. From point C the subcutaneous tunnel tract was created before the peritoneal steath towards the port site lateral to the umbilicus. Satisfactory catheter irrigation and outflow were then confirmed. Chemotherapy regimen after peritoneal dialysis catheterization: all patients began intraperitoneal chemotherapy on the second day after surgery. On the 1st and 8th day of each 3-weeks cycle, paclitaxel (20 mg/m(2)) was administered through peritoneal dialysis catheter, and paclitaxel (50 mg/m(2)) was injected intravenously. Meanwhile, S-1 was orally administered twice daily at a dose of 80 mg·m(-2)·d(-1) for 14 consecutive days followed by 7-days rest. To observe the patients' intraoperative and postoperative conditions. Results: All the procedures were performed successfully without intraoperative complications or conversion to laparotomy. No 30 day postoperative complications were observed. The median operative time was 33.5 (23-38) min. The median time to first flatus was 1(1-2) days, and the median postoperative hospital stay was 3 (3-4) days, without short-term complications within 30 days postoperatively. The last follow-up was up to July 10, 2019, and the patients were followed for 4(1-6) months. No ascites extravasation was observed and no death occurred in the 6 patients. There was no catheter obstruction or peritoneal fluid extravasation during and after chemotherapy. Conclusion: Laparoscopic peritoneal dialysis catheter implantation was safe and feasible for patients with peritoneal metastasis of gastric cancer. The abdominal exploration, tumor staging and the abdominal chemotherapy device implantation can be completed simultaneously, which could simplify the surgical approach, improve the quality of life for patients and further propose a new direction for the development of abdominal chemotherapy.

[The value of (18)F-FDG PET-CT imaging in predicting the malignant potential of GIST].

Objective: To evaluate the value of (18)F-FDG PET-CT in predicting the malignant potential of Gastrointestinal Stromal Tumors (GIST). Methods: The clinical and pathological features of 31 patients with GIST confirmed by surgery or biopsy were retrospectively analyzed. The malignant potential of GIST before treatment was assessed by (18)F-FDG PET-CT. The GIST risk classification was graded according to the Standard revised by the National Institutes of Health (NIH) in 2008. The relationship between the maximal standard uptake value (SUVmax) and GIST risk classification, tumor diameter, Ki-67 index, and mitotic count were analyzed respectively. The cut-off level of SUVmax for the diagnosis of malignant GIST was calculated from the Receiver Operating Characteristic (ROC) curve. Results: Among the 31 cases of GIST patients, 14 cases were gastric primary (stomach group) and 17 cases were nongastric primary (outside stomach group). The SUVmax, tumor diameter, Ki-67 index and mitotic count of the 31 patients were 8.21±4.68, (7.82±5.12)cm, (10.03±11.07)% and (12.29±10.55)/50 HPF, respectively. SUVmax was significantly correlated with GIST risk classification (r=0.727, P<0.01), but not with tumor diameter, Ki-67 index and mitotic count (r=0.348, r=0.284, r=0.290, P=0.055, P=0.121, P=0.114). The SUVmax, tumor diameter, Ki-67 index and mitotic count in the stomach group were 4.36±2.36, (6.08±4.31)cm, (3.43±3.03)% and (5.71±2.20)/50 HPF, respectively. SUVmax was significantly correlated with tumor diameter, GIST risk classification and Ki-67 index (r=0.682, r=0.868, r=0.732, P<0.01) but not with mitotic count (r=0.510, P=0.063). The SUVmax of the GIST in the gastric group and the outside gastric group were 4.36±2.36 and 10.68±5.50, respectively. The difference was statistically significant (P=0.001). The SUVmax in the malignant group of GIST (middle or high risk grade) was 8.90±4.89, which was significantly higher than 2.22±0.86 in the benign group (low or very low risk grade). The difference was statistically significant between the two group (P<0.01). ROC curve analysis showed that a SUVmax cut-off of 3.75 was the most sensitive for predicting malignant GIST. When the area under the curve of 0.969, the sensitivity was 84.6% and the specificity was 100%. Conclusions: The SUVmax was strongly correlated with the GIST risk category and also with the tumor diameter and Ki-67 index in the gastric primary GIST, so it can be used as an effective indicator in predicting malignant potential of GIST before treatment.

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.

Molecular diversity of 5S-rRNA spacer domain in Fritillaria species revealed by PCR analysis.

Beimu (bulbs of Fritillaria) is an important traditional Chinese herbal medicine commonly used as an antitussive and expectorant. There are about 25 species and varieties of Fritillaria that carry the name Beimu on commercial markets. The price for each Beimu may differ by more than 100-fold. However, the identification of the origin of a particular species on the market is difficult. Here, a molecular method was used to identify various species of Fritillaria regardless of their geographical origin. The 5S-rRNA coding sequence is highly conserved in higher eukaryotes, but the spacer sequence of the 5S-rRNA gene is variable among different species. Total genomic DNA from fresh leaves and bulbs of Fritillaria cirrhosa, F. puqiensis, F. anhuiensis, and F. thunbergii was extracted. The 5S-rRNA spacer region of the extracted DNAs was amplified by PCR with a pair of primers located within the conserved coding region. The isolated cDNA clones (approximately 600 bp) covering the 5S-rRNA spacer domain were sequenced. By aligning the isolated nucleotide sequences of the four Fritillaria species, sequence diversity was found in the spacer region. Furthermore, a unique EcoR I site was used for the rapid identification of different species of Fritillaria. To our knowledge, this is the first report on the detection of 5S-rRNA spacer domain sequences of Fritillaria and their use to identify species.

Mutations in Nu1, the gene encoding the small subunit of bacteriophage lambda terminase, suppress the postcleavage DNA packaging defect of cosB mutations.

The linear double-stranded DNA molecules in lambda virions are generated by nicking of concatemeric intracellular DNA by terminase, the lambda DNA packaging enzyme. Staggered nicks are introduced at cosN to generate the cohesive ends of virion DNA. After nicking, the cohesive ends are separated by terminase; terminase bound to the left end of the DNA to be packaged then binds the empty protein shell, i.e., the prohead, and translocation of DNA into the prohead occurs. cosB, a site adjacent to cosN, is a terminase binding site. cosB facilitates the rate and fidelity of the cosN cleavage reaction by serving as an anchoring point for gpNu1, the small subunit of terminase. cosB is also crucial for the formation of a stable terminase-DNA complex, called complex I, formed after cosN cleavage. The role of complex I is to bind the prohead. Mutations in cosB affect both cosB functions, causing mild defects in cosN cleavage and severe packaging defects. The lethal cosB R3- R2- R1- mutation contains a transition mutation in each of the three gpNu1 binding sites of cosB. Pseudorevertants of lambda cosB R3- R2- R1- DNA contain suppressor mutations affecting gpNu1. Results of experiments that show that two such suppressors, Nu1ms1 and Nu1ms3, do not suppress the mild cosN cleavage defect caused by the cosB R3- R2- R1- mutation but strongly suppress the DNA packaging defect are presented. It is proposed that the suppressing terminases, unlike the wild-type enzyme, are able to assemble a stable complex I with cosB R3- R2- R1- DNA. Observations on the adenosine triphosphatase activities and protease susceptibilities of gpNu1 of the Nu1ms1 and Nu1ms3 terminases indicate that the conformation of gpNu1 is altered in the suppressing terminases.

The antigenicity of GST antigen extracted from Chinese strain of Schistosoma japonicum.

The GST antigen, similar to Sj26 (Philippine strain), which plays an important role in inducing protective immunity against Schistosoma japonicum, can be extracted and purified from adult worms of the Chinese strain of S. japonicum. There are two bands at 26 kDa and 28 kDa of GST antigen called the 26-28 kDa GST antigen as identified by SDS-PAGE, and these have GST activities. Mice were immunized with the 26-28 kDa antigen and the specific antibody response in serum was assayed by ELISA, IFA and western blot. The antigenicity of the 26-28 kDa GST antigen in mice was significant. For example, the antigen could stimulate mice to increase the level of serum IgM and IgGl; the antibodies in serum of immunized mice could be localized in the antigenic determinants of tegument or body of the worms; specific antibodies against the antigens increased markedly after immunization as measured by ELISA or IFA; the antibody from mice immunized with the 26-28 kDa GST antigen can recognize 26-28 kDa antigenic molecules, identified by immunoblot assay.

The temperature--dependent expression of GST of Schistosoma japonicum (Philippine strain).

Obtained from pSj5, the cDNA gene encoding GST antigen of Schistosoma japonicum (Philippine strain) was ligated with efficient temperature-dependent PBV220 vector which was constructed in CAPM, and then introduced into host bacterium-DH5 alpha (E. coli) by transformation. Transformants were selected by ampicillin and recombinant clones were identified by restriction mapping. The result showed that recombinant clone 43 was the one carrying recombinant plasmid PBV 220 with the correct insertion of the gene fragment. The GST expression ability of clone 43 was investigated by GST enzymic activity assay and SDS-PAGE. A relatively high level of GST enzymic activity was expressed by this clone under the temperature-dependent condition, that is, cultured at 30 degrees C and expressed at 42 degrees C. A more strongly stained 26 kDa protein band was identified by SDS-PAGE. The result indicated that GST of S. japonicum (Philippine strain) could be expressed not only by IPTG induction, but also by the temperature-dependent method.

Comparative study on antigenicity and immunogenicity of 26-28 kDa antigen and recombinant Sj26 (RSj26) of Schistosoma japonicum.

This paper reports a comparison of the recombinant Sj26 (rSj26) antigen derived from the Philippine strain and the 26-28 kDa antigen isolated and purified from the Chinese strain of Schistosoma japonicum with respect to their antigenicity and immunogenicity. The results showed that there were obvious cross reactions between rSj26 and 26-28 kDa antigen when rSj26 antigen was tested against specific antibodies in sera of mice infected with the Chinese strain of S. japonicum or the 26-28 kDa antigen was tested against specific anti-rSj26 antibodies by ELISA, IFA and Western blotting. Both the 26-28 kDa and the rSj26 antigen had weak cross reactions with SEA antigen. The worm reduction rate after challenging with Chinese strain cercariae in mice immunized with rSj26 was 26-32%, similar to that in mice immunized with 26-28 kDa antigen. It is suggested that rSj26 antigen can induce a certain level of specific protective immunity in the host against infection by the Chinese strain of S. japonicum cercariae.

The possibility of GST antigen from Chinese strain of Schistosoma japonicum for immunodiagnosis of schistosomiasis.

The GST antigen (called 26-28 kDa antigen) extracted and purified from Schistosoma japonicum adult worms was applied to the detection of specific antibodies in sera of infected mice and mice immunized with the above protein antigen by ELISA technique. The 26-28 kDa antigen was better than crude antigens (SEA, SWAP) when used to detect specific antibodies in sera from immunized mice. As with crude antigens (SEA and SWAP), the 26-28 kDa antigen could be used to detect specific antibodies in infected sera, with titers as high as 1:160-1:320. There were no false positive reactions and a positivity rate as high as that using SWAP occurred when the 26-28 kDa antigen was used in schistosomiasis patients and normal subjects by intradermal test. It is suggested that the 26-28 kDa antigen may be a suitable candidate for immunodiagnosis of schistosomiasis.

Function of IHF in lambda DNA packaging. II. Effects of mutations altering the IHF binding site and the intrinsic bend in cosB on lambda development.

cosB is the binding site on lambda DNA for terminase, the phage DNA packaging protein. cosB contains three binding sites for gpNu1, the small subunit of terminase, and a site for integration host factor (IHF). IHF plays an accessory role in lambda DNA packaging, and IHF stimulates the burst size of lambda several-fold, presumably by assisting the interaction of terminase with cosB. The present work includes a study of the effect on lambda development of a mutation, called I1A-, which consists of three adjacent base-pair changes in the IHF binding site. The I1A- mutation was found to abolish IHF stimulation of the lambda burst size, indicating that IHF is unable to bind to the mutant I1A site. A second mutation, called I1B- and also consisting of three adjacent base-pair changes, is a mutation that reduces an intrinsic bend found in cosB. lambda I1B- was more dependent on IHF than lambda+, raising the possibility that the intrinsic bend in cosB plays a role in cos function for lambda+ under the IHF- conditions. In vitro DNA packaging experiments established that the I1 mutations affect DNA packaging per se. A series of Nu1 mutations that create terminases able to suppress a variety of cosB defects were found to suppress the defects of the I1A- and I1B- mutations under IHF- conditions.

Development and evaluation of a system of microencapsulation of primary rat hepatocytes.

To determine the in vitro function of microencapsulated hepatocytes, viable hepatocytes were isolated from rats and encapsulated within biocompatible alginate-polylysine membranes for in vitro studies. Urea formation, prothrombin and cholinesterase activity, the incorporation of tritiated leucine into intracellular proteins and the immunolocation of synthesized albumin were monitored in culture. Despite a decrease in some of these activities, the cultured hepatocytes continued to function throughout the 5-week observation period, producing and excreting urea, prothrombin and cholinesterase activity into the medium. In addition, albumin could be demonstrated within encapsulated hepatocytes for up to 5 weeks. Scanning and transmission electron microscopy showed the cells to be embedded within the alginate matrix and to retain a globular shape.

Microencapsulated hepatocytes for bioartificial liver support.

Free hepatocytes, harvested from normal rat livers by portal vein collagenase perfusion, were encapsulated within alginate-polylysine membranes and served as a liver support system. The encapsulated hepatocytes remained viable and were able to synthesize protein for up to 3 weeks in culture. Allografts of encapsulated hepatocytes replaced the function of a damaged liver and reduced the mortality rate among rats with galactosamine-induced fulminant hepatic failure.