Dual-tracer PET/CT-targeted, mpMRI-targeted, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer: a pilot study

PURPOSE

Growing evidence proved the efficacy of multi-parametric MRI (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-guided targeted biopsy (TB) in prostate cancer (PCa) diagnosis, but there is no direct comparison between mpMRI-TB and PSMA PET/CT-TB. Gastrin-releasing peptide receptor (GRPR) is highly expressed in PCa, which can compensate for the unstable expression of PSMA in PCa. Therefore, we designed a study to compare the efficiency of mpMRI-TB, dual-tracer (GRPR and PSMA) PET/CT-TB, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer.

METHODS

One hundred twelve suspicious PCa patients were enrolled from September 2020 to June 2021. Patients with anyone of positive dual-tracer PET/CT or mpMRI underwent TB, and all enrolled patients underwent systematic biopsy (SB) after TB. The primary outcome was the detection rates of PCa in different biopsy strategies. Secondary outcomes were the performance of three imaging methods, omission diagnostic rates, and upgrading and downgrading of biopsy samples relative to those of prostatectomy specimens in different biopsy strategies. McNemar's tests and Bonferroni correction in multiple comparisons were used to compare the primary and secondary outcomes.

RESULTS

In 112 men, clinically significant PCa (grade group[GG] ≥ 2) accounted for 34.82% (39/112), and nonclinically significant PCa (GG = 1) accounted for 4.46% (5/112). ⁶⁸ Ga-PSMA PET/CT-TB achieved higher PCa detection rate (69.77%) and positive ratio of biopsy cores (0.44) compared with SB (39.29% and 0.12) and mpMRI-TB (36.14% and 0.23), respectively (P < 0.005). Dual-tracer PET/CT screen out patients for avoiding 52.67% (59/112) unnecessary biopsy, whereas dual-tracer PET/CT-TB plus SB achieved high detection rate (77.36%) without misdiagnosis of csPCa.

CONCLUSION

Dual-tracer PET/CT might screen patients for avoiding unnecessary biopsy. Dual-tracer PET/CT-TB plus SB might be a more effective and promising strategy for the definite diagnosis of clinically significant PCa than mpMRI-TB.

Artificial intelligence for prediction of COVID-19 progression using CT imaging and clinical data

OBJECTIVES

Early recognition of coronavirus disease 2019 (COVID-19) severity can guide patient management. However, it is challenging to predict when COVID-19 patients will progress to critical illness. This study aimed to develop an artificial intelligence system to predict future deterioration to critical illness in COVID-19 patients.

METHODS

An artificial intelligence (AI) system in a time-to-event analysis framework was developed to integrate chest CT and clinical data for risk prediction of future deterioration to critical illness in patients with COVID-19.

RESULTS

A multi-institutional international cohort of 1,051 patients with RT-PCR confirmed COVID-19 and chest CT was included in this study. Of them, 282 patients developed critical illness, which was defined as requiring ICU admission and/or mechanical ventilation and/or reaching death during their hospital stay. The AI system achieved a C-index of 0.80 for predicting individual COVID-19 patients' to critical illness. The AI system successfully stratified the patients into high-risk and low-risk groups with distinct progression risks (p < 0.0001).

CONCLUSIONS

Using CT imaging and clinical data, the AI system successfully predicted time to critical illness for individual patients and identified patients with high risk. AI has the potential to accurately triage patients and facilitate personalized treatment.

KEY POINT

• AI system can predict time to critical illness for patients with COVID-19 by using CT imaging and clinical data.

Pre-symptomatic local brain activity and functional connectivity alterations in nasopharyngeal carcinoma patients who developed radiation encephalopathy following radiotherapy

Radiation encephalopathy (RE) is a common complication in patients with nasopharyngeal carcinoma (NPC) who have received radiotherapy (RT), and recent neuroimaging studies have shown brain alterations in Post-RT patients prior to RE. However, whether there are functional alterations between those Post-RT patients who are proved to have RE in follow-up and those who do not develop it remains largely unknown. Here, we used resting state functional MRI to explore regional homogeneity (ReHo) and functional connectivity (FC) alterations in Post-RT patients with (Post-RT _{RE proved}; n = 18) or without (Post-RT _non-RE; n = 22) RE at follow-up, also making comparisons with a Pre-RT group (n = 23). Compared with the Pre-RT group, patients in Post-RT _non-RE and Post-RT _{RE proved} groups showed concurrent increased and decreased ReHo values in different brain regions inside and/or outside the radiation field, with the alterations in ReHo tending to increase if RE occurred. Seed-based FC analysis showed that compared with the Post-RT _non-RE group, patients in the Post-RT _{RE proved} group had different changing patterns of FC between a region of interest (ROI) in the right temporal lobe and distant brain regions (mainly in the sensorimotor system and default mode network). Receiver operating characteristic (ROC) curve analysis showed that the altered ReHo value in the ROI had excellent diagnostic performance for differentiating NPC patients who developed RE in follow-up from those who did not, with an area under the curve (AUC) value of 0.94. These ReHo and FC findings may provide new insights into the early diagnosis of RE.

Roles of hsa-miR-12462 and SLC9A1 in acute myeloid leukemia

MicroRNAs (miRNAs) play important roles in cell proliferation, differentiation, and survival and may be useful for acute myeloid leukemia (AML) diagnosis and prognosis. In this study, we defined a novel miRNA, hsa-miR-12462, through small RNA sequencing of the bone marrow (BM) cells from 128 AML patients. Overexpression of hsa-miR-12462 in AML cells (U937 and HL-60) significantly decreased their growth rate when compared with those of the wild-type and MOCK controls. In a xenograft mouse model, tumor weight and size in the mice bearing the U937 cells with hsa-miR-12462 overexpression were significantly reduced when compared with those bearing the mock cells. The AML cells overexpressing hsa-miR-12462 had increased sensitivity to cytarabine chemotherapy. Combining the data from the MiRDB, an online microRNA database (http://mirdb.org), with the RNA-sequencing results, SLC9A1 was predicted to be one of the targets of hsa-miR-12462. hsa-miR-12462 was further confirmed to bind exclusively to the 3′UTR of SLC9A1 in U937 cells, leading to downregulation of SLC9A1. In summary, a higher level of hsa-miR-12462 in AML cells is associated with increased sensitivity to cytarabine chemotherapy via downregulation of SLC9A1.

A Predictive Scoring Model for Short-Term Local Recurrent Nasopharyngeal Carcinoma Based on Magnetic Resonance Imaging

OBJECTIVE

To predict the early identification of recurrence based on magnetic resonance imaging (MRI) in nasopharyngeal cancer (NPC) patients.

METHODS

The clinical and MRI data of 215 patients with local recurrent NPC were retrospectively reviewed. Logistic regression analysis was performed to distinguish the independent risk factors for the short-term (less than 24 months) local recurrence of NPC. The predictive score model was based on the regression coefficients of significant independent variables.

RESULTS

Residual disease in the nasopharyngeal cavity (NC), masticator space invasion (MSI), skull base bone erosion (SBBE), and MRI-detected cranial nerve invasion (MDCNI) were all significant independent risk factors for the short-term recurrence of NPC (p < 0.05). The receiver operating characteristic curve showed that the total score had a maximal AUC (area under the curve) value of 0.897, with a cutoff point of 10.50. The sensitivity and specificity were 79.4% and 80.5%, respectively.

CONCLUSION

Residual lesions in NC, MSI, SBBE, and MDCNI are independent risk factors in predicting the short-term recurrence of NPC. The authors' findings suggest that patients with a score of more than 10.50 points should be hypervigilant regarding the possibility of short-term recurrence.

Cortical Surface Area Rather Than Cortical Thickness Potentially Differentiates Radiation Encephalopathy at Early Stage in Patients With Nasopharyngeal Carcinoma

Radiation encephalopathy (RE) is one of the most severe complications in nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). However, the morphological alteration of early RE is insufficiently investigated. We aimed to investigate the cortical thickness and surface area alterations in NPC patients with or without RE in the follow-up. A total of 168 NPC patients each underwent a single scan and analysis at various times either Pre-RT (n = 56) or Post-RT (n = 112). We further divided the Post-RT NPC patients into three groups based on the time of the analysis following RT (Post-RT_{within 6 months} and Post-RT_{7-12 months}) or whether RE signs were detected in the analysis (Post-RT_{RE proved in follow-up}). We confined the vertex-wise analyses of the cortical thickness and surface area to the bilateral temporal lobes. Interestingly, we revealed a gradual increase in the cortical surface area of the temporal lobe with increasing time after RT within the Post-RT_{RE proved in follow-up} group, consistent with the between-group findings, which showed a significant increase in cortical surface area in the Post-RT_{RE proved in follow-up} group relative to the Pre-RT group and the Post-RT_{within 6 months} group. By contrast, such a trend was not observed in the cortical thickness findings. We concluded that the cortical surface area, rather than cortical thickness, may serve as a potential biomarker for early diagnosis of RE.

Changes in activities of both photosystems and the regulatory effect of cyclic electron flow in field-grown cotton (Gossypium hirsutum L) under water deficit

To clarify the influence of water deficit on the functionality of the photosynthetic apparatus of cotton plants, leaf gas exchange, chlorophyll a fluorescence, and P700 redox state were examined in field-grown cotton Gossypium hirsutum L. cv. Xinluzao 45. In addition, we measured changes in the P515 signal and analyzed the activity of ATP synthase and the trans-thylakoid proton gradient (ΔpH). With increasing water deficit, the net CO₂ assimilation rate (A_N) and stomatal conductance (g_s) significantly decreased, but the maximum quantum efficiency of PSII photochemistry (F_v/F_m) did not change. The photochemical activity of photosystem II (PSII) was reflected by the photochemical quenching coefficient (qP), quantum efficiency of photosystem II [Y(II)], and electron transport rate through PSII [ETR(II)], while the activity of photosystem I (PSI) was reflected by the quantum efficiency of photosystem I [Y(I)] and the electron transport rate through PSI [ETR(I)]. Both activities were maintained under mild water deficit, but were slightly decreased under moderate water deficit. Under moderate water deficit, cyclic electron flow (CEF), the fraction of absorbed light dissipated thermally via the ΔpH- and xanthophyll-regulated process [Y(NPQ)], and the fraction of P700 oxidized under a given set of conditions [Y(ND)] increased. Our results suggest that the activities of both photosystems are stable under mild water deficit and decrease only slightly under moderate water deficit. Moderate water deficit stimulates CEF, and the stimulation of CEF is essential for protecting PSI and PSII against photoinhibition.

The half-life of the cytochrome bf complex in leaves of pea plants after transfer from moderately-high growth light to low light

The content of cytochrome (cyt) bf complex is the main rate-limiting factor that determines light- and CO2-saturated photosynthetic capacity. A study of the half-life of the cyt f content in leaves was conducted whereby Pisum sativum L. plants, grown in moderately high light (HL), were transferred to low light (LL). The cyt f content in fully-expanded leaves decreased steadily over the 2 weeks after the HL-to-LL transfer, whereas control leaves in HL retained their high contents. The difference between the time courses of HL-to-LL plants and control HL plants represents the time course of loss of cyt f content, with a half-life of 1.7 days, which is >3-fold shorter than that reported for tobacco leaves at constant growth irradiance using an RNA interference approach (Hojka et al. 2014). After transfer to LL (16h photoperiod), pea plants were re-exposed to HL for 0, 1.5h or 5h during the otherwise LL photoperiod, but the cyt f content of fully-expanded leaves declined practically at the same rate regardless of whether HL was re-introduced for 0, 1.5h or 5h during each 16h LL photoperiod. It appears that fully-expanded leaves, having matured under HL, were unable to increase their cyt f content when re-introduced to HL. These findings are relevant to any attempts to maintain a high photosynthetic capacity when the growth irradiance is temporarily decreased by shading or overcast weather.

Different strategies of acclimation of photosynthesis, electron transport and antioxidative activity in leaves of two cotton species to water deficit

To better understand the adaptation mechanisms of the photosynthetic apparatus of cotton plants to water deficit conditions, the influence of water deficit on photosynthesis, chlorophyll a fluorescence and the activities of antioxidant systems were determined simultaneously in Gossypium hirsutum L. cv. Xinluzao 45 (upland cotton) and Gossypium barbadense L. cv. Xinhai 21 (pima cotton). Water deficit decreased photosynthesis in both cotton species, but did not decrease chlorophyll content or induce any sustained photoinhibition in either cotton species. Water deficit increased ETR/4-AG, where ETR/4 estimates the linear photosynthetic electron flux and AG is the gross rate of carbon assimilation. The increase in ETR/4-AG, which represents an increase in photorespiration and alternative electron fluxes, was particularly pronounced in Xinluzao 45. In Xinluzao 45, water deficit increased the activities of antioxidative enzymes, as well as the contents of reactive oxygen species (ROS), which are related to the Mehler reaction. In contrast, moderate water deficit particularly increased non-photochemical quenching (NPQ) in Xinhai 21. Our results suggest that Xinluzao 45 relied on enhanced electron transport such as photorespiration and the Mehler reaction to dissipate excess light energy under mild and moderate water deficit. Xinhai 21 used enhanced photorespiration for light energy utilisation under mild water deficit but, when subjected to moderate water deficit, possessed a high capacity for dissipating excess light energy via heat dissipation.

Rapid recovery of photosynthetic rate following soil water deficit and re-watering in cotton plants (Gossypium herbaceum L.) is related to the stability of the photosystems

The responses of gas exchange, chlorophyll fluorescence and the anti-oxidative system of cotton leaves were studied during water deficit and recovery. The results show that water deficit led to a reversible reduction in the photosynthetic rate. This reduction was mainly accompanied by stomatal limitation. The activity of photosystem II (PSII) and photosystem I (PSI) was relatively stable during water deficit and recovery. Water deficit caused an enhanced production of reactive oxygen species (ROS) and increased lipid peroxidation. Proline accumulation and the anti-oxidative enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POD), along with the antioxidant ascorbate (AsA), increased during water deficit. On re-watering, the ROS generation rate, anti-oxidative enzymes activities and the extent of the lipid peroxidation returned to near control values. Overall, rapid recovery of the photosynthetic rate is related to the stability of the photosystems which appears to be a critical mechanism allowing cotton plants to withstand and survive drought environments.

Simultaneous silencing of XIAP and survivin causes partial mesenchymal-epithelial transition of human pancreatic cancer cells via the PTEN/PI3K/Akt pathway

Pancreatic cancer has one of the highest mortality rates among malignant tumors and is characterized by rapid invasion, early metastasis and chemoresistance. X-linked inhibitor of apoptosis (XIAP) and survivin are two of the most important members of the IAP family. Previous studies have shown that XIAP and survivin were overexpressed in pancreatic cancer and were closely associated with cell proliferation and chemoresistance to gemcitabine. In the present study, stable inhibition of XIAP and survivin in Panc-1 cells was performed using lentivirus-carried short hairpin RNAs. The expression of XIAP, survivin, E-cadherin, Slug, phosphatase and tensin homolog (PTEN) and phosphorylated Akt was then measured. In addition, cell proliferation, apoptosis, invasion and migration were assessed. The results showed that stable inhibition of XIAP and survivin expression in Panc-1 cells significantly reduced cell proliferation, increased apoptosis and partially reversed the epithelial-mesenchymal transition (EMT). Furthermore, the results of the present study demonstrated that the partial reversal of the EMT was accompanied by inhibited cell invasion and migration as well as increased chemosensitivity to gemcitabine in pancreatic cancer cells; this was indicated to be mediated via the PTEN/phosphatidylinositol 3-kinase/Akt signaling pathway. In conclusion, these results suggested that simultaneous inhibition of XIAP and survivin may be a promising strategy for the treatment of pancreatic cancer.

MicroRNA-145 suppresses cell proliferation, invasion and migration in pancreatic cancer cells by targeting NEDD9

MicroRNAs (miRNAs) represent a class of small non-coding RNAs regulating gene expression by inducing the degradation of RNA or interfering with translation. Aberrant miRNA expression has been described in several types of cancer in humans. In the present study, it was demonstrated that miR-145 is downregulated in pancreatic cancer tissues and the Panc-1 cell line. Restoration of miR-145 inhibited cell proliferation, invasion and migration in Panc-1 cells. Neural precursor cell expressed, developmentally down-regulated 9 (NEDD9) has been identified as a novel potential miR-145 target using bioinformatics. Using luciferase reporter constructs, it was observed that the NEDD9 3′-untranslated region is the location of the direct binding site for miR-145. Additionally, it was identified that miR-145 is inversely correlated with NEDD9 expression in pancreatic cancer tissues and that restoration of miR-145 in Panc-1 cells reduced NEDD9 mRNA and protein expression accompanied by inhibition of cell proliferation, invasion and migration. In conclusion, these findings indicate that miR-145 may be an effective target for pancreatic cancer therapy.

Alternative electron sinks are crucial for conferring photoprotection in field-grown cotton under water deficit during flowering and boll setting stages

To clarify the photoprotective mechanisms of cotton leaves under water deficit in the field, leaf gas exchange, chlorophyll a fluorescence as well as the corresponding physiological responses were examined in cotton (Gossypium hirsutum L.) to evaluate electron flux distribution. With increasing water deficit, net photosynthetic rate (Pn) significantly decreased, the total electron flux through PSII [Je(PSII)] gradually decreased and the fraction of electron flux required to sustain CO2 assimilation [Je(PCR)] markedly declined. Simultaneously, the ratio of quantum efficiency of PSII [Φ(PSII)] to the quantum efficiency of CO2 fixation [Φ(CO2)] increased, accompanied by an increase in the alternative electron flux (Ja). The enhanced alternative electron flux of O2-dependent Ja(O2-dependent) indicated that electrons had been transported to O2 in the Mehler-peroxide reaction (MPR) and that the remaining alternative electron flux Ja(O2-independent) had been used for nitrate reduction, as indicated by an increase in nitrate reductase (NR) and glutathinone reductase (GR) activities. In addition, mild water deficit increased the proportion of electron flux for the photorespiratory carbon oxidation [Je(PCO)]. Water deficit significantly increased surperoxide radical production rate (O2-•) and hydrogen peroxide content (H2O2), and the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD) and catalase (CAT) in cotton leaves also increased under water deficit. Therefore, the Mehler-peroxidation reaction, photorespiration and nitrate reduction helped to dissipated excess light energy, being important photoprotective mechanisms for adapting the photosynthetic apparatus to mild and moderate water deficit in cotton.

Double inhibition of NF-κB and XIAP via RNAi enhances the sensitivity of pancreatic cancer cells to gemcitabine

The majority of patients with pancreatic cancer are resistant to gemcitabine. One of the mechanisms involved is the anti-apoptotic ability of these cells. The median lethal dose (LD50) of gemcitabine for PANC-1 cells was higher than that for Mia PaCa-2 cells and the former had higher nuclear factor-κB (NF-κB) and X-linked inhibitor of apoptosis protein (XIAP) levels. NF-κB contributes to the inhibition of apoptosis by the downregulation of downstream genes, such as XIAP and Bcl-2 and it confers chemoresistance. The two cell lines were infected with NF-κB p65 small interfering RNA (siRNA). p65 protein was effectively downregulated accompanied by the downregulation of XIAP protein. The combination treatment with gemcitabine and p65 siRNA increased the apoptotic rates in both cell lines; however, this was not sufficient. XIAP is involved in apoptosis to a greater extent compated to Bcl-2. XIAP may serve as another factor affecting the sufficiency of chemotherapy. XIAP siRNA was designed to knockdown XIAP. Mia PaCa-2 and PANC-1 cells were co-infected with XIAP siRNA and p65 siRNA. XIAP and p65 proteins were effectively downregulated and the gemcitabine-induced apoptotic rates were significantly increased. These results suggest that XIAP and NF-κB are two important factors conferring the chemoresistance of pancreatic cancer cells, and that their downregulation via RNAi effectively enhances the chemosensitivity of pancreatic cancer cells to gemcitabine.

Targeting X-linked inhibitor of apoptosis protein inhibits pancreatic cancer cell growth through p-Akt depletion

AIM: To determine whether lentivirus-mediated shRNA targeting the X-linked inhibitor of apoptosis protein (XIAP) gene could be exploited in the treatment of pancreatic cancer.

METHODS: Human pancreatic cancer cells Panc-1, Mia-paca2, Bxpc-3 and SW1990, infected with lentivirus, were analyzed by real-time polymerase chain reaction (PCR). Western blotting was used to examine XIAP protein levels, survivin and p-Akt to confirm the result of real-time PCR and determine the possible mechanism. The 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to measure IC₅₀ to determine chemosensitivity to the chemotherapeutic drugs 5-fluorouracil (5-FU) and gemcitabine. A colony assay, MTT assay and a tumorigenicity experiment were used to study cell proliferation in vitro and in vivo. Caspase-3/7 activity, 4',6-diamidino-2-phenylindole-staining and flow cytometric measurements were used to study apoptosis in SW1990 cells.

RESULTS: XIAP proteins were found to be differentially expressed among pancreatic cancer cell lines Panc-1, Mia-paca2, Bxpc-3 and SW1990. Data of real-time PCR and Western blotting showed that XIAP was reduced persistently and markedly by lentivirus-mediated shRNA. Downregulation of XIAP by transfection with XIAP shRNA resulted in decreased p-Akt expression. XIAP shRNA also inhibited the growth of pancreatic cancer cells in vitro and in vivo, enhanced drug-induced apoptosis and increased chemosensitivity to 5-FU and gemcitabine. Results also suggest that inhibition of XIAP and subsequent p-Akt depletion may have an anti-tumor effect through attenuating the ability of cancer cells to survive.

CONCLUSION: Lentivirus-mediated gene therapy is an attractive strategy in the treatment of pancreatic cancer and justifies the use of lentivirus in pancreatic cancer gene therapy studies.

Isolation of laccase gene from Bacillus subtilis and analysis of its physicochemical properties

The present study reports the cloning and sequencing of lac2 from Bacillus subtilis. The gene is composed of 1542 bp and encodes a 514-amino acid protein. The gene has 86% homology with a published laccase with GeneID 936023. The lac2 gene was deposited in GenBank as a new nucleotide sequence. This new sequence was cloned into the multiple cloning site of pPIC9K to generate pPIC9K-lac2, which was then transformed into Pichia pastoris GS115 via electroporation. The recombinant GS115 (pPIC9K-lac2) was grown initially in BMGY medium and transferred to BMMY to induce gene expression for 48 h. The recombinant Lac2 protein shows laccase activity with α-naphthol and guaiacol as substrates. The optimal pH is between 3.2 and 4.7, and the optimal temperature is 25°C for enzyme reaction.

Lentivirus-mediated shRNA targeting XIAP and survivin inhibit SW1990 pancreatic cancer cell proliferation in vitro and in vivo

The aim of this study was to investigate the inhibitor of apoptosis proteins survivin and XIAP in pancreatic cancer by determining their biological characteristics and expression. XIAP and survivin are potential therapeutic targets for pancreatic cancer, and elucidating their association with cell proliferation and apoptosis may lead to the development of novel treatments for this disease. The human pancreatic cancer SW1990 cell line was infected with lentivirus and then analyzed by real-time PCR, and the results were confirmed by Western blotting. The MTT assay and the determination of caspase-3/-7 activity, DAPI-staining and tumorigenicity were used to measure cell proliferation and apoptosis in the human pancreatic cancer SW1990 cell line and in an experimental pancreatic cancer mouse xenograft model inoculated with the lentivirus-transfected SW1990 cells. The results revealed that the XIAP and survivin proteins were differentially expressed among the pancreatic cancer cell lines, and their decreased expression resulted in the inhibition of cell proliferation in vitro as well as in vivo. These findings suggest that lentivirus-mediated gene therapy targeting XIAP and survivin is a potential and attractive strategy for the treatment of pancreatic cancer.

Reduction of Toxic Effect of Ammonia on Metabolism of Recombinant CHO-GS Cell

The toxic effect of ammonia on rCHO-GS cell decreased obviously due to the transfection of GS system in serum-free culture. The maximum cell density, 15.6 x 10(5) cells/mL was obtained in the culture with 1.42 mmol/L ammonia. The growth of rCHO-GS cell was inhibited with an increased ammonia concentration. However, a cell density of 8.9 x 10(5) cells/mL was obtained when the concentration of ammonia was 12.65mmol/L. The intracellar metabolic pathways were affected due to the decrease of the toxic effect of ammonia on rCHO-GS cell. With the increase of initial ammonia concentration from 0.36mmol/L to 12.65mmol/L, the yield coefficients of cell to glucose and lactate to glucose decreased. The activities of hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) increased by 43%, 140% and 25%, respectively, indicating that the utilization of glucose increased and the glycolysis pathway was more prone to efficient energy metabolism pathway. An increased activity of glutamate-pyruvate aminotransferase (GPT) showed that the conversation from glutamate to alpha-ketoglutarate was shifted to glutamate-pyruvate transamination pathway. The deamination pathway was inhibited due to a decreased activity of glutamate dehydrogenase. In addition, the number of cells in G0/G1 phase increased and the specific production rate of recombinant protein increased by 2.1-fold with the increase of initial ammonia concentration from 0.36mmol/L to 12.65mmol/L.

[A study on the model of tuberculous pleurisy and intrapleural inflammatory and immunological responses in rats]

OBJECTIVE

To develop a rat model of tuberculous pleurisy and to explore the mechanism of intrapleural inflammatory and immunological responses.

METHODS

Fifty Wistar rats were injected intrapleurally with 0.03 mg of standard human mycobacterium tuberculous bacilli H37Rv each. The rats were killed in group on days 1, 2, 3, 5, 7, 10, 15, 20, 30 and 60 after the day of intrapleural injection. The thorax was opened and the amount of pleural effusion was recorded, and histopathology of pleural tissues and lung tissues were observed. The white blood cell (WBC) count and differentials, levels of total protein (TP), glucose (GLU) and lactic dehydrogenase (LDH) of pleural effusions were determined. Pleural fluid was analyzed for the levels of soluble intercellular adhesion molecule-1 (sICAM-1), transforming growth factor beta1 (TGF-beta1) and interferon gamma (IFN-gamma) by using appropriate bioassays. Ten rats were intrapleurally received 2 ml of normal saline and another 10 rats received 2 ml of undiluted PPD solution each as control.

RESULTS

Bilateral pleural effusions appeared within 15 days in all rats intrapleurally received tuberculous bacilli. The peak amount of pleural fluid was on day 5 (6.7 +/- 0.5 ml). The neutrophils were the predominant cells for the first 24 hours, and then were followed by lymphocytes. In the pleural fluid, total protein concentration was between 51-55 g/L. The levels of glucose and LDH were 5.2 mmol/L and 18.1 micromol.s(-1).L(-1) on day 1 and changed to 2.8 mmol/L and 28.9 micromol.s(-1).L(-1) on day 15 respectively. The biochemistry parameters were in accordance with characteristics of tuberculous pleurisy. The sICAM-1 level increased early (21.9 ng/ml on day 1) and peaked on day 3 (38.0 ng/ml), then decreased over time (4.4 ng/ml on day 15). The level of IFN-gamma was 41.2 pg/ml on day 1 and increased and maintained at high levels over time. TGF-beta1 levels increased and peaked on day 7 (47.2 ng/ml), and then on day 15 decreased to a level lower than that of day 1. The ratio of IFN-gamma/TGF-beta1 increased from 1.32 on day 1 to 5.69 on day 15. Correlation analysis showed that sICAM-1 and IFN-gamma were closely related with WBC count and its differentials, as well as with LDH levels. Histopathological study revealed early pleural inflammation and late caseation.

CONCLUSIONS

Wistar rats can be used as an experimental model for tuberculous pleurisy. Tuberculous inflammatory and immunological responses in acute tuberculous pleurisy is enhanced rather than suppressed.

Evaluation of clinical significance of isoferritin by development of new monoclonal antibodies specific for acidic isoferritin

We produced monoclonal antibodies (MAbs) against acidic isoferritin (AIF) of primary hepatic carcinoma (PHC) and human placental tissues. Competitive enzyme-linked immunosorbent assay (ELISA) revealed that each MAb bound to different antigenic determinants of AIF, but there is the same epitope between PHC AIF and placental AIF. Sandwich-type ELISA was developed to measure the concentration of serum AIF in the patients with PHC, chronic hepatitis, and cirrhosis. In most of cases of PHC, serum AIF levels were found to be significantly elevated, but were in low levels in almost all of the patients with chronic hepatitis and cirrhosis. On the other hand, we have studied the expression of AIF in liver tissue. Immunohistochemical study using MAb4c9 specific for PHC AIF and MAb7a9 specific for placental AIF has shown that AIF positive staining rates of hepatocytes with liver tissues of PHC, nonmalignant live diseases and normal control were 81.6, 6.7, 0%, and 73.7, 10, 0%, respectively. We also studied the p53 protein expression in those liver tissues (47.4, 0, 0% in PHC, nonmalignant liver diseases and normal liver, respectively). Our data indicated that there was significant correlation between AIF and p53 expression in liver tissues of PHC. Taken together, the results suggested that AIF is probably synthesized and secreted by the tumor cells of PHC and its production may reflect carcinogenesis of hepatocytes. Anti-PHC AIF MAb was clearly superior in diagnosis of PHC to antiplacental AIF MAb, and has potential application of immunotherapy.

[The distribution of epidemic hemorrhagic fever (EHF) viral antigen in tissues from EHF autopsies]

Tissues from twelve cases of epidemic hemorrhagic fever (EHF) autopsies between 1962 and 1986 were examined for the distribution of EHF viral antigen by double bridge peroxidase antiperoxidase (PAP) method and avidin biotin conjugate peroxidase technique. EHF viral antigen was found frequently in the brain, kidney, heart, lung, liver, spleen, adrenal gland and pancreas. Viral antigen was also detected in the cerebellum, spinal cord, pituitary gland, stomach, trachea, lymph nodes and tonsils in some of the cases. The positive cells were found mainly in the endothelia of capillaries and small blood vessels. Only a few parenchymal cells showed positive reaction. However, epithelia of renal tubules, alveolar cells of pancreas and some endocrine glands (adrenal, thyroid and pituitary, etc) were positive. The distribution of viral antigen was not fully consistent with the degree of pathologic changes in the tissues.