Anticancer pan-ErbB inhibitors reduce inflammation and tissue injury and exert broad-spectrum antiviral effects

Targeting host factors exploited by multiple viruses could offer broad-spectrum solutions for pandemic preparedness. Seventeen candidates targeting diverse functions emerged in a screen of 4,413 compounds for SARS-CoV-2 inhibitors. We demonstrated that lapatinib and other approved inhibitors of the ErbB family of receptor tyrosine kinases suppress replication of SARS-CoV-2, Venezuelan equine encephalitis virus (VEEV), and other emerging viruses with a high barrier to resistance. Lapatinib suppressed SARS-CoV-2 entry and later stages of the viral life cycle and showed synergistic effect with the direct-acting antiviral nirmatrelvir. We discovered that ErbB1, ErbB2, and ErbB4 bind SARS-CoV-2 S1 protein and regulate viral and ACE2 internalization, and they are required for VEEV infection. In human lung organoids, lapatinib protected from SARS-CoV-2-induced activation of ErbB-regulated pathways implicated in non-infectious lung injury, proinflammatory cytokine production, and epithelial barrier injury. Lapatinib suppressed VEEV replication, cytokine production, and disruption of blood-brain barrier integrity in microfluidics-based human neurovascular units, and reduced mortality in a lethal infection murine model. We validated lapatinib-mediated inhibition of ErbB activity as an important mechanism of antiviral action. These findings reveal regulation of viral replication, inflammation, and tissue injury via ErbBs and establish a proof of principle for a repurposed, ErbB-targeted approach to combat emerging viruses.

Anticancer pan-ErbB inhibitors reduce inflammation and tissue injury and exert broad-spectrum antiviral effects

Targeting host factors exploited by multiple viruses could offer broad-spectrum solutions for pandemic preparedness. Seventeen candidates targeting diverse functions emerged in a screen of 4,413 compounds for SARS-CoV-2 inhibitors. We demonstrated that lapatinib and other approved inhibitors of the ErbB family receptor tyrosine kinases suppress replication of SARS-CoV-2, Venezuelan equine encephalitis virus (VEEV), and other emerging viruses with a high barrier to resistance. Lapatinib suppressed SARS-CoV-2 entry and later stages of the viral life cycle and showed synergistic effect with the direct-acting antiviral nirmatrelvir. We discovered that ErbB1, 2 and 4 bind SARS-CoV-2 S1 protein and regulate viral and ACE2 internalization, and they are required for VEEV infection. In human lung organoids, lapatinib protected from SARS-CoV-2-induced activation of ErbB-regulated pathways implicated in non-infectious lung injury, pro-inflammatory cytokine production, and epithelial barrier injury. Lapatinib suppressed VEEV replication, cytokine production and disruption of the blood-brain barrier integrity in microfluidic-based human neurovascular units, and reduced mortality in a lethal infection murine model. We validated lapatinib-mediated inhibition of ErbB activity as an important mechanism of antiviral action. These findings reveal regulation of viral replication, inflammation, and tissue injury via ErbBs and establish a proof-of-principle for a repurposed, ErbB-targeted approach to combat emerging viruses.

Modular HIV-1 Capsid Assemblies Reveal Diverse Host-Capsid Recognition Mechanisms

The HIV-1 capsid is an ordered protein shell that houses the viral genome during early infection. Its expansive surface consists of an ordered and interfacing array of capsid protein hexamers and pentamers that are recognized by numerous cellular proteins. Many of these proteins recognize specific, assembled capsid interfaces not present in unassembled capsid subunits. We used protein-engineering tools to capture diverse capsid assembly intermediates. We built a repertoire of capsid assemblies (ranging from two to 42 capsid protein molecules) that recreate the various surfaces in infectious capsids. These assemblies reveal unique capsid-targeting mechanisms for each of the anti-HIV factors, TRIMCyp, MxB, and TRIM5α, linked to inhibition of virus uncoating and nuclear entry, as well as the HIV-1 cofactor FEZ1 that facilitates virus intracellular trafficking. This capsid assembly repertoire enables elucidation of capsid recognition modes by known capsid-interacting factors, identification of new capsid-interacting factors, and potentially, development of capsid-targeting therapeutics.

FEZ1 Is Recruited to a Conserved Cofactor Site on Capsid to Promote HIV-1 Trafficking

HIV-1 uses the microtubule network to traffic the viral capsid core toward the nucleus. Viral nuclear trafficking and infectivity require the kinesin-1 adaptor protein FEZ1. Here, we demonstrate that FEZ1 directly interacts with the HIV-1 capsid and specifically binds capsid protein (CA) hexamers. FEZ1 contains multiple acidic, poly-glutamate stretches that interact with the positively charged central pore of CA hexamers. The FEZ1-capsid interaction directly competes with nucleotides and inositol hexaphosphate (IP6) that bind at the same location. In addition, all-atom molecular dynamic (MD) simulations establish the molecular details of FEZ1-capsid interactions. Functionally, mutation of the FEZ1 capsid-interacting residues significantly reduces trafficking of HIV-1 particles toward the nucleus and early infection. These findings support a model in which the central capsid hexamer pore is a general HIV-1 cofactor-binding hub and FEZ1 serves as a unique CA hexamer pattern sensor to recognize this site and promote capsid trafficking in the cell.

[Value of double contrast-enhanced ultrasound QontraXt three-dimensional pseudocolor quantitative analysis to therapeutic effect evaluation of preoperative neoadjuvant chemotherapy in advanced gastric cancer patients]

Objective: To investigate the value of tumor perfusion parameter measured by using double contrast-enhanced ultrasound (DCEUS) QontraXt three-dimensional pseudocolor quantitative analysis to the therapeutic effect evaluation of preoperative neoadjuvant chemotherapy (NAC) in advanced gastric cancer (AGC) patients. Methods: Eighty-nine AGC patients underwent 3 cycles of preoperative NAC (XELOX) followed by complete resection of lesion. The DCEUS QontraXt three-dimensional pseudocolor was performed one or two weeks before the NAC and operation were applied, respectively. The peak enhancement (PE), time to peak (TP), sharpness of the bolus (β) and area under the enhancement curve (AUC) of primary gastric tumor were measured by QontraXt three-dimensional pseudocolor quantitative analysis. These DCEUS parameters between respond and non-respond groups before and after NAC therapy were compared. The prediction accuracy of DCEUS to the therapeutic effect evaluation of preoperative NAC was determined by the receive operating characteristic (ROC) curves. Results: Among 89 AGC patients, 52 patients responded to NAC therapy, while 37 patients resisted to NAC therapy. Twelve cases in respond group and 26 cases in non-respond group were mucinous carcinoma. Forty cases in respond group and 11 cases in non-respond group were non-mucinous carcinoma (P<0.05). In responder group, the PE and TP before NAC were (53.7±9.3)% and (14 521±2 667) ms, and (32.2±5.5)% and (17 235±1 898) ms after NAC. The ratio of changes of PE (ΔPE) and TP (ΔTP) were 0.43±0.17 and 0.36±0.14, respectively. In non-respond group, the PE and TP before NAC were (54.4±7.2)% and (13 869±3 247) ms, and (45.3±6.1)% and (15 127±1 423) ms after NAC therapy. The ratio of ΔPE and ΔTP were 0.24±0.20 and 0.22±0.12. The PE and TP after NAC, the ratio of ΔPE and ΔTP were significant different among these two groups (all of P<0.05). The ROC curves showed that the ratio of ΔPE in assessing the respond of gastric cancer patients to NAC was superior compared to other parameters (AUC=0.784, P=0.004). The optimal cut-off value of the ratio of ΔPE was 24% and its sensitivity and specificity to the therapeutic effect evaluation of NAC in gastric cancer were 82.7% and 64.9%. Conclusion: DCEUS QontraXt three-dimensional pseudocolor quantitative analysis might be a novel, noninvasive and reliable method to evaluate the therapeutic effect of preoperative NAC in AGC patients.

Isolation of biosurfactant producers, optimization and properties of biosurfactant produced by Acinetobacter sp. from petroleum-contaminated soil

AIMS

To screen and identify biosurfactant producers from petroleum-contaminated soil; to use response surface methodology (RSM) for medium optimization to enhance biosurfactant production; and to study the properties of the newly obtained biosurfactant towards pH, temperature and salinity.

METHODS AND RESULTS

We successfully isolated three biosurfactant producers from petroleum-contaminated soil and identified them through 16S rRNA sequence analysis, which exhibit the highest similarities to Acinetobacter beijerinckii (100%), Kocuria marina (99%) and Kineococcus marinus (99%), respectively. A quadratic response model was constructed through RSM designs, leading to a 57·5% increase of the growth-associated biosurfactant production by Acinetobacter sp. YC-X 2 with an optimized medium: beef extract 3·12 g l(-1) ; peptone 20·87 g l(-1) ; NaCl 1·04 g l(-1); and n-hexadecane 1·86 g l(-1). Biosurfactant produced by Acinetobacter sp. YC-X 2 retained its properties during exposure to a wide range of pH values (5-11), high temperatures (up to 121°C) and high salinities [up to 18% (w/v) Na(+) and Ca(2+) ], which was more sensitive to Ca(2+) than Na(+).

CONCLUSIONS

Two novel biosurfactant producers were isolated from petroleum-contaminated soil. Biosurfactant from Acinetobacter sp. YC-X 2 has good properties to a wide range of pH, high temperature and high salinity, and its production was optimized successfully through RSM.

SIGNIFICANCE AND IMPACT OF THE STUDY

The fact, an increasing demand of high-quality surfactants and the lack of cost-competitive bioprocesses of biosurfactants for commercial utilization, motivates researchers to develop cost-effective strategies for biosurfactant production through isolating new biosurfactant producers with special surface-active properties and optimizing their cultural conditions. Two novel biosurfactant producers in this study will widen our knowledge about this kind of micro-organism. This work is the first application of RSM designs for cultural optimization of biosurfactant produced by Acinetobacter genus and the first report that biosurfactant may be more sensitive to Ca(2+) than Na(+) .

Development of recombinant adeno-associated virus and adenovirus cocktail system for efficient hTERTC27 polypeptide-mediated cancer gene therapy

The low in vivo transduction efficiency of recombinant adeno-associated virus (rAAV) and the undesirably strong immunogenicity of adenovirus (rAdv) have limited their clinical utilization in cancer gene therapy. We have previously demonstrated that intratumoral injection of rAAV expressing a C-terminal polypeptide of human telomerase reverse transcriptase (rAAV-hTERTC27) effectively inhibits the growth of glioblastoma xenografts in nude mice. To further improve its efficacy, we combined rAAV-hTERTC27 with rAdv and investigated the efficiency of the cocktail vectors in vivo. At a nontherapeutic dose (1 x 10(8) plaque-forming units (PFUs)), rAdv-null and rAdv-hTERTC27 were equipotent in enhancing the therapeutic efficacy of rAAV-hTERTC27 (1.5 x 10(11) v.g.), and complete tumor regression was achieved in 25% of the treated animals. Importantly, the combination of rAAV-hTERTC27 and a therapeutic dose (2.5 x 10(9) PFU) of rAdv-hTERTC27 significantly augmented the therapeutic effects and led to a 38% complete tumor regression rate. In vivo optical imaging also showed that rAAV-luc/rAdv-luc cocktail vectors could synergistically enhance the early transient and latent sustained expression of luciferase, as compared to rAdv-luc and rAAV-luc alone. These findings suggest that the combination of rAAV-hTERTC27 and a therapeutic dose of rAdv-hTERTC27 is potentially a promising treatment for glioblastoma, and the rAAV/rAdv cocktail vector system warrants further development for cancer gene therapy.

A novel glioblastoma cancer gene therapy using AAV-mediated long-term expression of human TERT C-terminal polypeptide

Glioblastoma multiforme is the most aggressive form of human brain tumor, which has no effective cure. Previously, we have demonstrated that overexpression of the C-terminal fragment of the human telomerase reverse transcriptase (hTERTC27) inhibits the growth and tumorigenicity of human cervical cancer HeLa cells. In this study, the therapeutic effect and molecular mechanisms of hTERTC27-mediated cancer gene therapy were further explored in vivo in established human glioblastoma xenografts in nude mice. We showed that intratumoral injection of adeno-associated virus carrying hTERTC27 (rAAV-hTERTC27) is highly effective in reducing the growth of the subcutaneously transplanted glioblastoma tumors. Histological analyses showed that rAAV-hTERTC27 treatment leads to profound necrosis, apoptosis, infiltration of polymorphonuclear neutrophils and reduced microvessel density in the tumor samples. To study the molecular mechanism of rAAV-hTERTC27-mediated antitumor effects, we analyzed the global gene expression profiles of the rAAV-hTERTC27-treated tumor tissues and cell line as compared with that of the control rAAV-green fluorescent protein-treated samples by DNA microarray. Our results suggest that hTERTC27 exerts its effect through complex mechanisms, which involve genes regulating apoptosis, cell adhesion, cell cycle, immune responses, metabolism, signal transduction, transport, transcription and telomere maintenance.

Suspended aggregates as an immobilization mode for high-density perfusion culture of HEK 293 cells in a stirred tank bioreactor

Cells of the human embryonic kidney cell line (HEK 293) grown in repeated suspension and perfusion systems were characterized and described. Cell aggregates that formed immediately after the HEK 293 cells were inoculated in stirred vessels in serum-containing Dulbecco's modified Eagle's medium (D-MEM)/F-12 medium. The mean diameter of the cell aggregates reflecting the aggregate size increased with culture time, shifting from 63 to 239 mum after 1 and 8 days of culture in spinner flasks, respectively. No significant differences in cell performance were observed between HEK 293 cell populations grown as suspended aggregates and those grown as anchored monolayers. Replacing the D-MEM/F-12 with CD 293 medium caused the compact spherical cell aggregates to dissociate into single cells and small irregular aggregates without any apparent effect on cell performance. Moreover, the spherical cell aggregates could reform from individual cells and small aggregates when exposed to the serum-containing D-MEM/F-12 dominant medium. Perfusion culture of HEK 293 cells grown as suspended aggregates in a 7.5-l stirred tank bioreactor for 17 days resulted in a maximum viable cell density of 1.2 x 10(7) cells ml(-1). These results demonstrate the feasibility and proof-of-concept for using aggregates as an immobilization system in large-scale stirred bioreactors because a small-scale culture can be used as easily as the inoculum for larger bioreactors.

Structural influence of hanatoxin binding on the carboxyl terminus of S3 segment in voltage-gated K(+)-channel Kv2.1

The voltage-sensing domains of voltage-gated potassium channels Kv2.1 (drk1) contain four transmembrane segments in each subunit, termed S1 to S4. While S4 is known as the voltage sensor, the carboxyl terminus of S3 (S3C) bears a gradually broader interest concerning the site for gating modifier toxins like hanatoxin and thus the secondary structure arrangement as well as its surrounding environment. To further examine the putative three-dimensional (3-D) structure of S3C and to illustrate the residues required for hanatoxin binding (which may, in turn, show the influence on the S4 in terms of changes in channel gating), molecular simulations and dockings were performed. These were based on the solution structure of hanatoxin and the structural information from lysine-scanning results for S3C fragment. Our data suggest that several basic and acidic residues of hanatoxin are electrostatically and stereochemically mapped onto their partner residues on S3C helix, whereas some aromatic or hydrophobic residues located on the same helical fragment interact with the hydrophobic patch of the toxin upon binding. Therefore, a slight distortion of the S3C helix, in a direction toward the N-terminus of S4, may exist. Such conformational change of S3C upon toxin binding is presented as a possible explanation for the observed shift in hanatoxin binding-induced gating.

Effectiveness of postoperative adjuvant therapy in improving reproductive outcome of endometriosis-associated infertility

BACKGROUND AND PURPOSE

Treatment of endometriosis-associated infertility has not yet become standardized. Various protocols including surgical treatment, medical therapy, and a combination of both have been suggested but their use remains controversial. The objective of the present study was to determine whether postoperative adjuvant therapy for endometriosis is effective in improving reproductive outcome.

METHODS

Medical records of infertile patients with newly diagnosed endometriosis treated in a university teaching hospital during a 50-month period were reviewed. After exclusion of patients with other major infertility factors, a total of 209 patients were included in the retrospective analysis. These patients were divided into those receiving (n = 78) or not receiving (n = 131) peri- or postoperative adjuvant medical therapy. The adjuvant therapies included danazol (n = 62), gonadotropin releasing hormone analogues (n = 11), progestins (n = 3), oral contraceptives (n = 1), and mixed treatment (n = 1).

RESULTS

The pregnancy rate was lower in those receiving adjuvant therapy, although this result was not significant (32.1% vs 45.8%; p = 0.05). When patients using postoperative danazol therapy were considered alone, the pregnancy rate in patients receiving adjuvant therapy was significantly lower than that in patients not receiving it (p = 0.047). When the stage of endometriosis was considered, the pregnancy rate in patients receiving adjuvant therapy was again lower than in those not receiving it in patients with minimal or mild endometriosis (42.9% vs 60%; p = 0.043). However, in patients with moderate or severe endometriosis, the pregnancy rate was not different in the two groups (31% vs 36%; p = 0.56). Postoperative assisted reproductive techniques (ART) including controlled ovarian hyperstimulation/intrauterine insemination (COH/IUI) and in vitro fertilization (IVF) were effective in improving the pregnancy rates for all patients (53.9% with ART vs 33.1% without; p = 0.003) and for patients with advanced endometriosis (47.7% with ART vs 27.2% without; p = 0.016).

CONCLUSIONS

Our results suggest that postoperative adjuvant therapy is ineffective in improving reproductive outcome in patients with either early (minimal or mild) or advanced (moderate and severe) endometriosis. This finding suggests that if fertility is the goal of treatment, adjuvant therapy may be unnecessary after surgery. In contrast, our data suggest that empirical ART, including COH/IUI or IVF, may be a better alternative to improve the pregnancy outcome after surgery.

[Bovine alpha-sl-casein gene sequences direct expression of a variant of human tissue plasminogen activator in the milk of transgenic mice]

The fusion gene containing the promoter of casein gene, LAtPA minigene and 3' flanking sequences of casein gene was introduced into the fertilized eggs of mice by microinjection. Five positive transgenic mice were obtained. The concentration of LAtPA in the milk of one female transgenic mouse is 0.18 microgram/ml. This result showed that the LAtPA minigene could correctly express the bioactive LAtPA in the milk of the transgenic mouse under the control of the regulatory elements of the casein gene.

Identification of stress-responsive genes in Streptococcus mutans by differential display reverse transcription-PCR

Streptococcus mutans, which causes dental caries in the human oral cavity and occasionally causes infective endocarditis in the heart, withstands adverse environmental stress through diverse alterations in protein synthesis. Differential gene expression in response to environmental stress was analyzed by RNA fingerprinting using arbitrarily primed PCR with a panel of 11mer primers designed for differential display in Enterobacteriaceae. Dot and Northern blot hybridization confirmed that the transcription of several genes was up- or down-regulated following exposure to acid shock from pH 7.5 to 5.5. RNA of a gene designated AP-185 (acid-stress protein) was induced specifically by acid treatment, while RNA of GSP-781 (general-stress protein) was up-regulated significantly when bacteria were exposed to high osmolarity and temperature, as well as low pH. The deduced amino acid sequence of AP-185 shares homology (78% identity) with branched-chain amino acid aminotransferase. Cloning and sequence analysis of GSP-781 revealed a potential secreted protein of a molecular mass of about 43 kDa and with a pI predicted to be 5.5. Transcriptional levels of another gene, designated AR-186 (acid-repressed protein), which encodes putative aconitase, were repressed by acid treatment but were enhanced by plasma or serum components. Analogous results were identified in icd and citZ genes, and repression of these genes, along with AR-186, was also observed when they were exposed to high osmolarity and temperature. These results indicate that differential regulation of specific genes at the transcriptional level is triggered by different stress and that genes responsible for glutamate biosynthesis in the citrate pathway are coordinately regulated during the stress response of S. mutans.

[New advances and future perspectives in mammal cloning]

To the great extent, the study and application of transgenic animal are restricted by the inherent limitation of pronuclear microinjection. Recently, the rapid progresses in gene targeting and cloning of somatic cells have shown that the combination of these two technologies will become a virtual way to producing large transgenic animals.

[The expression of tPA directed by the bovine BLG regulatory elements in the mammary gland of transgenic mice]

In order to get the regulatory elements which are essential for generating mammary gland bioreactors, the whole 8.4 kb bovine BLG gene was obtained by PCR amplification. The 1.6 kb chicken lysozyme matrix attachment region (MAR) was used to overcome position effects. The bovine BLG-tPA expression vector was constructed and the BLG-tPA fusion gene was introduced into fertilized eggs of mice by microinjection to generate transgenic mouse. 170 offsprings were obtained, of which 9 were proved to be transgenic mice based on PCR and Southern-blot analysis. The tPA expression level amounted to 12 micrograms/mL in the milk of mice. The bovine BLG-tPA fusion gene integrated in the founders was inheritable.

The feasible sequential control strategy of treating high strength organic nitrogen wastewater with sequencing batch biofilm reactor

The bio-kinetics and feasible sequential control strategy of treating high strength organic carbon and nitrogen wastewater were investigated by conducting the ABS manufacturing wastewater in a series of Sequencing Batch Biofilm Reactors (SBBRs). The on-line ORP, pH, and DO monitoring parameters were applied to identify the feature-points when ammonification, nitrification, and denitrification ends. The carbonaceous matter removal kinetics in the anaerobic and aerobic reaction stages can be expressed by the Michaelis-Menten equation. High efficiency of organic carbon removal and organic nitrogen ammonification in the anaerobic stage can eliminate the substrate competition and activation inhibition to nitrifying organisms in the following aerobic stage. In the sequencing nitrogen removal processes, the producing time and system ORP values of these feature-points have good function relationships with the influent COD loading rates of SBBR, which can be integrated into a set-point (set-time and set-ORP) sequential control strategy of nitrogen removal. The automatic control operation results revealed ORP was one of the major control parameters of the sequencing nitrogen removal process in SBBR system and high overall removal efficiency were obtained.

[Co-integration of BLG-LAtPA and WAP improved the expression of LAtPA in transgenic mouse milk]

In order to improve the expression of longer acting tissue plasminogen activator in the mammary epithelium of transgenic mice, the fragment of BLG-LAtPA hydrid gene was microinjected into mouse embryos with mice whey acid protein gene. Three mouse were tested as being Co-integration of BLG-LAtPA and WAP transgene by PCR and Southern blot. Milk obtained from lactating females contains biologically active tPA, and the concentration of tPA was calculated to be about 10 micrograms/mL.

[High cell density culture of phosphotransacetylase mutants of Escherichia coli BL21(DE3)]

Cell culture, organic acid production and foreign protein (TNF) expression of E. coli BL21(DE3) and its pta mutant were investigated. Under shaking conditions, TNF expression in pta mutant increased by 23%. During the fed-batch culture without limitation of specific growth rates, the mutant reached a cell density as high as 32.5 g(DCW)/L and total TNF expression at 2.8 g/L, while the parental strain only obtained 19.5 g(DCW)/L and 0.84 g/L. The results indicate that utility of pta mutant as a host is advantageous in foreign protein expression and high cell density culture. Meanwhile, the analysis data of organic acids accumulated during fed-batch culture showed that as the decrease of acetate production(42% of the parental strain), the accumulation of other organic acids(mainly pyruvate, lactate and succinate) obviously increased. As a result, the amount of total organic acids increased by 123% over its parent. The lactate production may be the main obstacle in further growth of the cells.

Conopeptides from Conus striatus and Conus textile by cDNA cloning

Conopeptide content in Conus textile and Conus striatus venoms were examined by polymerase chain reaction amplification of alpha-conopeptide cDNA and rapid amplification of 3' cDNA ends of O-superfamily conopeptide cDNA. Two new alpha-conopeptide sequences and six new O-superfamily conopeptide sequences from C. textile, four new O-superfamily conopeptide sequences, and four previously biochemically characterized conopeptide sequences from C. striatus were identified. The results suggest that this cDNA method is rapid and requires less material for the study of conopeptides.

[The analysis of biological characteristics for the tissue-plasminogen activator (t-PA) mutant engineered cell line]

The morphology of t-PA mutant engineered cell line FSGGI48 is similar to that of CHO-dhfr- cell in polygon. When aminopterin (MTX) concentration is 5 x 10(-6) mol/L, a part of cells become slim, but they are still in polygon. Therefore, the morphology of FSGGI48 cell line is normal. The expression level is 4000 IU/10(6) cells/24 h in serum-free medium. The cell line is bequeathed for three months in vitro and revived after freezing three months, the greater part of cells are stable. The expression level is 3000-4000 IU/10(6) cells/24 h. The assay of tumorigenesis shows that the cells, cellular DNA and purified products don't form tumors in nude mice. The cell line hasn't been contaminated by mycoplasma. The results of chromosomal analysis show that the chromosomal number of CHO-dhfr- cell is 20 and the abnormal rate is 6%. FSGGI48 cell line is same as CHO-dhfr- cell in chromosomal number and the abnormal rate is 15%-18%, it is normal in scope. Therefore, the engineered cell line FSGGI48 is excellent.

Sclerotherapy on liver cirrhosis with esophageal variceal bleeding: eight years of experience

BACKGROUND

Patients with liver cirrhosis usually die of hepatic failure and variceal bleeding. Successful treatment of the latter can reduce mortality. Sclerotherapy is one method often used. This study compared (a) the successful rate of acute bleeding control; (b) short- and long-term survival rate between those with and without treatment with sclerotherapy to evaluate the clinical benefit of sclerotherapy for liver cirrhosis patients with esophageal variceal bleeding.

METHODS

Between August 1983 and December 1991, 183 cirrhotic patients with esophageal variceal bleeding receiving endoscopic injection sclerotherapy (EIS) was compared with 123 patients without sclerotherapy treatment retrospectively. The severity of underlying liver disease was classified using a modified Child's classification. Sclerotherapy was done within 48 hours after active bleeding in the sclerotherapy-treated group, while the medical treatment group received Sengstaken-Blakemore (SB) tube or pitressin infusion only.

RESULTS

Successful rate of acute bleeding control was 81.63% (120/147) in the EIS group and 59.35% (73/123) in the medical treatment group. The worse the hepatic function of the patients, the lower the success of acute bleeding control in both groups. Fifty subjects (74.63%) had varices eradicated in 67 sclerotherapy treatment patients with regular follow-up. Patients receiving EIS had a better long-term survival than those without treatment. Benefit of EIS on long-term survival was more significant in Child B patients and less in Child C and Child A patients. Death from variceal bleeding was lower in the EIS group than in the medical treatment group (32% vs 62.6%). Complications of EIS were rare. Eight patients died of aspiration pneumonia, spontaneous bacterial peritonitis or acute renal failure after sclerotherapy, and most were Child B and C patients. Sixteen patients had esophageal stricture. Four needed dilatation treatment.

CONCLUSIONS

The sclerotherapy-treated group had a higher control rate of acute bleeding and lower mortality rate from esophageal variceal bleeding compared with the medical-treated group. The procedure prolonged long-term survival in Child B patients but did so less frequently in Child A and Child C patients. The incidence of complications was low. As a whole, EIS is a safe and efficient method for control of esophageal variceal bleeding.

Body lead stores and urate excretion in men with chronic renal disease

OBJECTIVE

To determine the relationship of urate excretion to body lead stores in patients with chronic renal disease without previous lead exposure.

METHODS

We compared 40 male subjects in 3 groups, on the basis of their serum creatinine and histories of gout, with serum urate, creatinine clearance, urate clearance, daily urate excretion, fractional urate excretion, and body lead stores. Group 1 consisted of 10 patients with normal serum creatinine levels and no evidence of gout. Group 2 contained 10 men with gout and abnormal serum creatinine levels. Group 3 included 20 subjects with abnormal serum creatinine levels and no evidence of gout. All patients received EDTA mobilization tests and 72 h urine collections. The total amount of lead excreted over 72 h was estimated as the body lead stores. An ANOVA test with Fisher pairwise least significant difference, correlation coefficients, and multiple linear regression test were used to measure any statistical significance among these variables. A p value < 0.05 was considered significant.

RESULTS

Lead stores and serum urate were significantly higher in gouty patients with renal insufficiency than those of other groups, but the urate excretion of gouty patients was not relatively increased. Not only was there a significant correlation between creatinine clearance and urate excretion, but body lead stores also appeared to be negatively related to urate excretion in our patients, even though body lead stores in these subjects were within the normal range.

CONCLUSION

Our findings suggest that lead may play a role in gouty patients with impaired renal function and chronic low level environmental lead exposure may subtly affect urate excretion in patients with chronic renal disease.

Long-term observation of morphologic and functional features of cat corneal endothelium after wounding

PURPOSE

(1) To test the hypothesis that corneas with enlarged endothelial cells (and thus less intercellular space) have decreased endothelial permeability to small polar solutes. (2) To measure corneal endothelial ouabain binding (Na+/K+ ATPase "pump site" density) and Descemet's membrane production after endothelial wounding.

METHODS

Bilateral specular microscopy and anterior segment fluorophotometry were performed at 2-month intervals for 1 year in ten cats after mechanically damaging the corneal endothelium in one eye of each. The measurements were repeated at 2 years in four cats and at 3 years in two cats. Eighteen months after wounding, endothelial ouabain binding was measured in both eyes of six cats. Transmission electron micrographs of Descemet's membrane were analyzed in both eyes of six cats at 18 months, two cats at 2 years, and two cats at 3 years after wounding.

RESULTS

From 6 to 12 months after wounding, the endothelial permeability to carboxyfluorescein was significantly decreased (P < 0.05), and the mean endothelial cell size was significantly increased (P < 0.001) in the damaged eyes. The enlarged endothelial cells persisted in the few cats observed 2 and 3 years after wounding. There was no significant difference in endothelial ouabain binding between the damaged and control corneas in six cats tested 18 months after wounding. On subsequent histologic examination, a layer of abnormal Descemet's membrane was present in all ten wounded eyes, with additional normal Descemet's membrane posterior to it, between the abnormal layer and the endothelial cells.

CONCLUSIONS

The results are consistent with the hypothesis that corneal endothelial permeability to small polar solutes varies directly with the amount of intercellular space available for diffusion across the monolayer. The results also confirm clinical reports of decreased endothelial permeability in corneas with enlarged endothelial cells. In histopathologic specimens, a layer of abnormal Descemet's membrane can be a historical marker for a period of endothelial damage and corneal decompensation.

Expression of the cloned gene for enterotoxin STb of Escherichia coli

This study involved the construction of hybrid plasmids to produce heat-stable enterotoxin type II of Escherichia coli (STb). The translation of the open reading frame for the STb gene estA was demonstrated in several ways. Studies using in vivo labeling with [35S]cysteine demonstrated a radiolabeled protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the expected molecular weight of 5,000 for toxin STb. Insertion of translational or transcriptional termination signals into the BglII site of the estA gene blocked the expression of estA. The estA gene was cloned into high-expression vector pKC30 downstream from the strong pL promoter. Northern (RNA) blotting assays revealed a 10- to 20-fold increase in mRNA produced by strain C600F(pKC30STb) over other STb-producing strains, compared with little or no increase in enterotoxin activity demonstrated by bioassay. The estA gene, with its own promoter and Shine-Delgarno region and a portion of the sequence for the signal peptide deleted, was also inserted under the control of the tac promoter. Even after induction of the tac promoter by addition of isopropyl-beta-D-thiogalactopyranoside, no biologic enterotoxin activity could be identified. Neutralizing antibodies to STb were produced in rabbits by using either a purified OmpF-STb-beta-galactosidase fusion protein or a 19-amino-acid synthetic STb peptide coupled to keyhole limpet hemocyanin.

The morphology and function of healing cat corneal endothelium

We mechanically damaged the entire corneal endothelium of one eye of each of ten cats and then examined both eyes by fluorophotometry and specular microscopy for 5 months. Six weeks after damage, when the corneas had cleared sufficiently to make accurate measurements, the mean endothelial permeability to carboxyfluorescein was increased 11% (P = 0.02) and the mean central corneal thickness was increased 11% (P = 0.05) in the damaged eyes. The mean endothelial pump rate was decreased 29% (P = 0.05), indicating that the increase in permeability was insufficient to explain the increase in thickness. The permeability returned to normal by 3 months and the pump rate by 5 months. Six weeks after damage, the mean endothelial cell size was increased 89% (P less than 0.01), the mean coefficient of variation of cell size was increased 200% (P less than 0.01), and the mean percentage of hexagonal cells was decreased 34% (P less than 0.01). By 5 months, the mean cell size had changed very little, and none of the three morphologic measurements had returned to normal. As in rabbits, the endothelial barrier in cats recovers before the pump after wounding. Unlike in rabbits, functional recovery in cats requires at least several months. Such prolonged functional recovery after endothelial trauma might also be expected in humans who, like cats and unlike rabbits, have little capacity for endothelial mitosis during healing.

Effects of alteration in the light cycle on outer segment shedding in the fetal retina

Shedding of outer segment discs and their phagocytosis by retinal pigment epithelial cells (RPE) in the guinea pig starts to occur during in utero development. The number of phagosomes in the fetal RPE varies in a cyclical manner somewhat analogous to that observed in mature animals. The present study addresses the question of whether the cycles in fetus and mother are independent or linked. Pregnant guinea pigs were subjected to 10 days of alteration of their lighting schedules beginning on the 46th day of gestation. Dams and fetuses were sacrificed on day 56, and large phagosomes in the RPE of each were counted. A 10-hour phase advance was employed, ie, from 0800 (lights on): 2000 (light off) in controls, to 2200 (on): 1000 (off) in experimental animals. Counts of large phagosomes in the posterior retina were compared in both control and experimental nulliparous, gravid, and fetal animals. A significant burst of shedding occurred within one hour after light onset in the experimental groups comprised of either nulliparous or pregnant animals. The latter also showed a smaller rise in phagosome numbers at the original time of onset of illumination. In contrast, no shift in the time of maximum shedding activity was observed in fetuses in the experimental regime. Their activity was similar to that present in the original 0800:2000 cycle. Whereas maternal RPE shedding cycles can be reentrained in a 10-day period, those in the 46- to 56-day fetal retina are refractory to significant change. Based on this finding, it is likely that the shedding cycles in the mother and fetus at this age are under independent control, and, therefore, that shedding in the fetus is not mediated by maternal borne factors.

Phagocytosis in the fetal pigment epithelium: evidence for cyclic activity

Photoreceptor cells in guinea pig retinas begin to shed their outer segments while developing in utero. To ascertain whether phagocytosis of outer segments in the fetus is a cyclical event like that of mature animals, large phagosomes in fetal retinal pigment epithelial cells were counted at representative times during a 24 hr period. These data were then compared with similar data obtained from the pregnant dams. Gravid animals and fetuses both showed a burst of shedding after the onset of illumination. Shedding was well initiated in the pregnant animals 30 min after the onset of illumination but was delayed for 2 to 3 hr in their fetuses. Thereafter the two patterns of phagocytosis showed substantial differences. Congruent cyclical patterns could be discerned, however, by graphing fetal counts with an advance of 10 hr on the time scale relative to that of the gravid animals. The results presented here represent the first indication of a cyclical pattern of phagocytosis in a population of fetuses during retinal development.

Phagocytosis of photoreceptor outer segments during retinal development in utero

The retinal pigmented epithelium of the fetal guinea pig was examined for evidence of phagocytosis and degradation of outer segments. Beginning at the early stages of outer segment formation and continuing through the remaining fetal period, pigment epithelial cells contained large and small phagosomes with multi-lamellated internal structure. Thus, mammalian retinal photoreceptor cells which normally develop and mature in utero in the absence of light undergo a process of phagocytosis of outer segemnt fragments comparable to that found in species whose retinae mature postnatally outside of the uterus.