Magnifying image-enhanced endoscopy-only mode boosted early cancer diagnostic efficiency: a multicenter randomized controlled trial

BACKGROUND AND AIMS

Magnifying image-enhanced endoscopy (MIEE) is an advanced endoscopy with image enhancement and magnification used in preoperative examination. However, its impact on the detection rate is unknown.

METHODS

We conducted an open-label, randomized, parallel (1:1:1), controlled trial in 6 hospitals in China. Patients were recruited between February 14, 2022 and July 30, 2022. Eligible patients were aged ≥18 years and undergoing gastroscopy in outpatient departments. Participants were randomly assigned to the MIEE-only mode (o-MIEE) group, white-light endoscopy-only mode (o-WLE) group, and MIEE when necessary mode (n-MIEE) group (initial WLE followed by switching to another endoscope with MIEE if necessary). Biopsy sampling of suspicious lesions of the lesser curvature of the gastric antrum was performed. Primary and secondary aims were to compare detection rates and positive predictive value (PPV) of early cancer and precancerous lesions in these 3 modes, respectively.

RESULTS

A total of 5100 recruited patients were randomly assigned to the o-MIEE (n = 1700), o-WLE (n = 1700), and n-MIEE (n = 1700) groups. In the o-MIEE, o-WLE, and n-MIEE groups, 29 (1.51%; 95% confidence interval [CI], 1.05-2.16), 4 (.21%; 95% CI, .08-.54), and 8 (.43%; 95% CI, .22-.85) early cancers were found, respectively (P < .001). The PPV for early cancer was higher in the o-MIEE group compared with the o-WLE and n-MIEE groups (63.04%, 33.33%, and 38.1%, respectively; P = .062). The same trend was seen for precancerous lesions (36.67%, 10.00%, and 21.74%, respectively).

CONCLUSIONS

The o-MIEE mode resulted in a significant improvement in diagnosing early upper GI cancer and precancerous lesions; thus, it could be used for opportunistic screening. (Clinical trial registration number: ChiCTR2200064174.).

[Analysis of the cognitive effects of monocular blindness and related influencing factors]

Objective: To investigate the cognitive effects of monocular blindness and related influencing factors. Methods: A cross-sectional study was conducted. The patients with monocular blindness (the age of onset <16 years) were enrolled from Beijing Tongren Eye Center, Beijing Tongren Hospital between January 2018 and June 2020. The Montreal cognitive assessment (MoCA) scale was applied to assess seven cognitive domains including visuospatial and executive function, naming, attention, etc. Based on MoCA scores, all the patients were classified into two groups: normal cognitive functions and cognitive impairment. Spearman's correlation was used to perform the single factor analysis of the influencing factors of cognitive functions. Multivariate linear regression analyses were applied to identify the independent influencing risk factors. Results: A total of 45 patients with monocular blindness were enrolled. There were 25 males and 20 females, with age at testing being (27±10) years.The incidence of cognitive impairment in 45 patients was 60.0% (27/45). The abnormal items ranking from a high to low rate were language (95.6%, 43 cases), delayed recall (75.6%, 34 cases), visuospatial and executive function (60.0%, 27 cases), abstract (44.4%, 20 cases), attention (35.6%, 16 cases), naming (20.0%, 9 cases), and orientation (0%). There were statistically significant differences (all P<0.05) in total score (21.9±3.3 vs. 27.4±1.4), visuospatial and executive function (3.2±1.7 vs. 4.6±0.7), naming (2.7±0.6 vs. 2.9±0.2), attention (5.3±1.0 vs. 5.8±0.4), language (1.1±0.8 vs. 1.8±0.8), abstract (1.1±0.8 vs. 1.8±0.5) and delayed recall (2.3±1.3 vs. 4.4±0.8) between two groups of patients with and without cognitive impairment. Spearman's correlation analysis showed visuospatial and executive functions, attention, abstract and MoCA total score were positively correlated with education years (correlation coefficients being 0.355, 0.424, 0.434 and 0.370, respectively; all P<0.05). Multiple linear regression showed that duration of blindness was correlated with naming (β=-0.325), and years of education correlated with attention (β=0.472), abstract ability (β=0.441) and MoCA total score (β=0.390) (all P<0.05). Conclusions: Monocular blindness may affect language, delayed memory and visuospatial executive functions. The duration of blindness is an independent risk factor, and higher education is a protective factor of the cognitive impairment.

[Ultrasonic manifestations and axis length of blind microphthalmia]

Objective: To discuss the ultrasonic manifestations of blind microphthalmia, and to explore the correlation between axis length and complicity of intraocular structure of blind microphthalmia. Methods: Retrospective case series study. The data of ultrasonic imaging and axis length of 162 patients (162 eyes) with blind microphthalmia diagnosed in Tongren Eye Center, Beijing Tongren Hospital from July 2013 to July 2018 were collected. According to the degree of internal structure disorder, all affected eyes were divided into groups of the normal, the abnormal and the indistinguishable. The binocular axial length in these patients were compared. The relationship between the axial length and the age of the patients, and the structural changes of the blind microphthalmia with a basic structure were analyzed. Statistical methods were mainly performed by paired t-test, one-way linear regression analysis and one-way analysis of variance. Results: The disease was unilateral in all the 162 patients. The age ranged from 1 month to 58 years old. And 139 cases (85.80%) were under 12 years old. There were 90 males and 72 females. The mean axial length of the affected eyes (162 eyes) was (13.17±3.77) mm, while the mean axial length of the control eyes (162 eyes) was (21.85±2.01) mm. There was significantly statistical difference in the ocular size between them (t=-27.369; P<0.01). There was no significant correlation between the axial length of the affected eye and age in patients with unilateral blind microphthalmia (r=0.027; P>0.05), while there was a significant correlation between the axial length of the control eye and age (r=0.590; P<0.01). The axial length of the groups of the normal (14 eyes), the abnormal (91 eyes) and the indistinguishable (57 eyes) was (17.80±2.19) mm, (14.81±2.92) mm and (10.05±2.46) mm, respectively, and the difference was statistically significant (F=72.800; P<0.01), and there was also significant difference between the two groups (all P<0.01). Ocular ultrasonic imaging showed that 105 eyes (64.81%) had a basic ocular structure, 83 eyes (51.23%) had retinal detachment, 15 eyes (9.26%) had bulbar ossification, and 10 eyes (6.17%) had optic disc abnormality. Conclusions: Blind microphthalmia mostly has a basic ocular structure and is often associated with retinal detachment. The axial length of the affected eye is correlated with the degree of intraocular structural disorder. (Chin J Ophthalmol, 2021, 57: 825-829).

Intrinsical localization of both topological (anti-kink) envelope and gray (black) gap solitons of the condensed bosons in deep optical lattices

By developing quasi-discrete multiple-scale method combined with tight-binding approximation, a novel quadratic Riccati differential equation is first derived for the soliton dynamics of the condensed bosons trapped in the optical lattices. For a lack of exact solutions, the trial solutions of the Riccati equation have been analytically explored for the condensed bosons with various scattering length a_s. When the lattice depth is rather shallow, the results of sub-fundamental gap solitons are in qualitative agreement with the experimental observation. For the deeper lattice potentials, we predict that in the case of a_s>0, some novel intrinsically localized modes of symmetrical envelope, topological (kink) envelope, and anti-kink envelope solitons can be observed within the bandgap in the system, of which the amplitude increases with the increasing lattice spacing and (or) depth. In the case of a_s<0, the bandgap brings out intrinsically localized gray or black soliton. This well provides experimental protocols to realize transformation between the gray and black solitons by reducing light intensity of the laser beams forming optical lattice.

[Ocular manifestations and surgical treatment of the linear nevus sebaceous syndrome]

Objective: To report the clinical and pathological features and surgical treatment of the linear nevus sebaceous syndrome. Methods: It was a retrospective case series study. The clinical records of 11 patients (14 eyes) who were diagnosed as linear nevus sebaceous syndrome between April 2009 and February 2018 at Beijing Tongren Hospital were analyzed. Data collected included sex, age, clinical manifestations, disease site, pathological features, surgical treatment and therapeutic effects. Results: There were six males and five females, aged 6 months to 7 years (mean, 2.8 years). The nevus sebaceous was located at the head (9 patients), face (5 patients) and neck (3 patients). The most common ocular manifestations were blepharocoloboma (13 eyes) and external ocular mass (9 eyes). Surgical treatment was performed in 9 patients (11 eyes), including lid reconstruction in all these eyes, corneal and conjunctival mass resection in four patients (4 eyes), eyelid tumor resection in 5 patients (5 eyes), and symblepharon separation and conjunctival sac reconstruction in 3 patients (5 eyes). Pathological examinations of the external ocular, corneal and conjunctival masses (6 eyes) confirmed the diagnosis of complex choristoma. All operated patients had improved appearance. Conclusions: Linear nevus sebaceous syndrome has characteristic cutaneous lesions and ocular manifestations. Histopathologically, all epibulbar lesions prove to be complex choristomas. The appearance of patients with linear nevus sebaceous syndrome can be significantly improved by oculoplastic surgery. (Chin J Ophthalmol, 2020, 56: 846-852).

[Clinical features and surgical management of orbitotemporal neurofibromatosis]

Objective: To report the clinical features and surgical treatment of orbitotemporal neurofibromatosis. Methods: It was a retrospective case series study. The clinical records of 24 patients who were treated for orbitotemporal neurofibromatosis between April 2007 and July 2017 at Beijing Tongren Hospital, Capital Medical University were analyzed. Data collected included sex, age, laterality, periorbital deformities, surgical treatment, follow-up time, complication and recurrence. Results: Sixteen males and 8 females were included. Age at surgery was (15±7) years (4-30 years). All patients were unilaterally involved. Twenty-three patients (96%) had upper lid involvement and ptosis. Nine patients (38%) had lower lid involvement. Fourteen patients (58%) had lateral canthal disinsertion. Three patients (13%) had brow involvement, 10 patients (42%) had conjunctival involvement and 2 patients (8%) had lacrimal gland infiltration. All patients had tumor debulking procedure. Twenty-two patients (92%) had correction of ptosis. Fourteen patients (58%) required lid reconstruction and lateral canthus reattachment surgery. Three patients (13%) had correction of brow ptosis.One patient (4%) had skull and orbit reconstruction. The median follow-up time was 3.5 (1.0-10.0) years. All patients had improved appearance. Ptosis recurred in 6 patients, but were corrected with surgery. On the last follow-up, 7 patients were free of ptosis. In 14 patients, mild ptosis was noted, but the upper lid did not cover the pupil. In 2 patients the pupil was half covered. Only in 1 patient who had not received ptosis correction surgery the pupil was covered completely. Conclusions: The periorbital deformities of orbitotemporal neurofibromatosis include upper eyelid infiltration with ptosis, lateral canthal disinsertion and infiltration of lower eyelid, brow, conjunctiva and lacrimal gland. The appearance of patients with orbitotemporal neurofibromatosis can be significantly improved through oculoplastic surgery. (Chin J Ophthalmol, 2019, 55: 828-833).

[Etiological and drug sensitivity analysis of lacrimal canaliculitis]

Objective: To analyze the etiology and drug sensitivity of lacrimal canaliculitis. Methods: Retrospective study of case series. The general information, culture results and drug sensitivity results of 52 patients (including 10 males and 42 females with an average age of 60.3 years) clinically diagnosed with lacrimal canaliculitis during 2011 and 2016 at Beijing Tongren Hospital of Capital Medical University have been analyzed. The enumeration data have been tested with Chi-square method. Results: The positive rate of bacterial culture was 78.8%, and the fungal culture tests of all cases showed negative results. Sixty strains of bacteria were isolated from 41 patients whose bacterial culture tests showed positive results, Gram-positive bacteria have been confirmed as the main among the isolated bacteria with Streptococcus (18.3%), Propionibacterium (18.3%), and Streptococcus (15.0%) identified as the three common genera. Thirteen cases (25.0%, all the 13 patients were female) involved with mixed infection, 13.3% (8/60) of the isolated strains were multi-drug resistant bacteria. The drug sensitive rate of the bacteria to fluoroquinolones antibiotics(79.3%, 230/290) was higher than that to cephalosporins(62.1%, 36/58) and aminoglycoside antibiotics(56.3%, 98/174), and such differences are of statistical significance (χ(2)=7.977, 27.738, P<0.05). Except for the fact that gram-positive bacteria are mostly sensitive to vancomycin, the sensitive rate of the bacteria to gatifloxacin was the highest and that to tobramycin was the lowest. Conclusion: Lacrimal canaliculitis tend to affect women and elderly patients. Staphylococcus, Propionibacterium, and Streptococcus are the three most common genera. Gatifloxacin may be the preferred antibiotic. Antibiotics combination therapy should be applied for multi-drug resistant bacteria. (Chin J Ophthalmol, 2018, 54: 111-114).

[Value of CT in evaluating the risk of benign and malignant thyroid nodules]

Objective: To evaluate the value of CT in the risk assessment of thyroid benign nodules (BN) and malignant nodules (MN). Methods: The CT signs of 461 pieces of MN in 447 cases and 548 pieces of BN in 484 cases were retrospectively analyzed, the diagnoses were confirmed by histology, including nodular morphology, cookie bite sign, microcalcification, enhanced range narrow/blurred, cystic changes and enhanced.The signs of CT were analyzed by univariate and multivariate regression analysis.The positive CT signs were calculated to assess sensitivity and specificity in the diagnosis of BN and MN. Results: Univariate and multivariate analysis showed that irregular nodular morphology (χ(2)=509.263, P<0.001, OR=5.297), cookie bite sign (χ(2)=504.619, P<0.001, OR=3.467), microcalcification (χ(2)=97.793, P<0.001, OR=1.730), enhanced range reduction/blur (χ(2)=361.967, P<0.001, OR=5.729) were more common in MN.Cysts changes (χ(2)=223.208, P<0.001, OR=7.537) and enhancement signs (χ(2)=65.983, P<0.001, OR=10.782) were more common in BN.The sensitivity and specificity of irregular nodular morphology in the diagnosis of MN were 80.5% and 90%, those in cookie bite sign were 74.2% and 94.3%, microcalcification were 35.6% and 90.1%, enhanced range reduction/blur were 80.7% and 79.4%.The sensitivity and specificity of capsule-based and high-enhanced BN diagnosis were 42.2% and 98.1%, 19.0% and 97.4%, respectively. Conclusions: Irregular shape, cookie bite sign, microcalcification and enhanced range of narrowing/blur are significant CT signs in the assessment of MN, and cystic changes and enhancement are significant CT signs in the evaluation of BN.The diagnostic efficiency of various CT signs varies greatly, and combination of multiple CT signs can improve the diagnostic efficiency.

[Developing and application of an autoverification system for clinical chemistry and immunology test results]

Objective: To develop and validate an autoverification system for biochemistry and immunology test results for application in routine work. Methods: Algorithms was designed and translated into the laboratory information system. Parameters including verify limit, delta check, logic relation between tests was set up in the system. Verification rate of every test and the causes of fails were analyzed, according to which the system and parameters were modified. The autoverified reports were evaluated by chief technicians. Only when all of the autoverified results pass the evaluation, the system applied for routine work of releasing the results. Autoverification rate and turnaround time(TAT) were calculated for evaluation of the efficiency of the system. Results: A brand new autoverification system was developed and applied for routine work. The autoverification rate for each single test was 91.1%-96.6%. The autoverification rate for reports was 74%. With the autoverification system, the media of TAT reduced from 111.6(53.9-270.7) min to 87.2(45.4-202.4) min, whereas the time from instrument finishing analysis to releasing the reports reduced from 18.6(1.0-99.3) min to 0.1(0-58.3)min. The number of staff specified for results validation reduced from three to one. Conclusions: The newly developed system can be used for autoverification of biochemistry and immunology test results. The autoverification system can greatly reduce TAT and raise working efficiency. It's essential to employ carefully designed algorithm, appropriate parameters and comprehensive evaluation when developing a new autoverification system.

[Effects and related mechanism of quercetin on thrombin-induced proliferation and migration of rat vascular smooth muscle cells]

OBJECTIVE

To investigate the effects and related mechanism of quercetin on thrombin-induced proliferation and migration of rat vascular smooth muscle cells(VSMCs).

METHODS

Third to fifth generation VSMCs were divided into three groups, including control group (with PBS on the base of medium DMEM), thrombin group (with 1 U/ml thrombin on the base of medium DMEM) and quercetin group (treated with 100 μmol/L quercetin before 1 U/ml thrombin on the base of medium DMEM). The proliferation and migration capacitities were tested by CCK-8 kit and transwell chamber, respectively. The protein level of phospho-extracellular signal regulated kinase 1/2 and phosphor-p38 were measured by Western blot.

RESULTS

(1) According to the CCK-8 results, optical density value was significantly higher in thrombin group than that of control group(2.59±0.16 vs. 1.97±0.18, P<0.01), which could be significantly attenuated by pretreatment with quercetin(2.13±0.19, P<0.01), and there was no significant difference between quercetin group and control group(P>0.05). (2) The transwell results showed that the migrated VSMCs were significantly higher in thrombin group than in control group (1 337±162 vs. 99±26, P<0.01), which could be significantly reduced by pretreatment with quercetin (926±111, P<0.05), but still significantly higher than control group (P<0.01). (3) The protein expressions of phospho-extracellular signal regulated kinase 1/2 and phosphor-p38 were significantly upregulated in thrombin group compared to control group (both P<0.05), which could be significantly downregulated by pretreatment with quercetin (P<0.05).

CONCLUSION

Quercetin can effectively attenuate thrombin-induced vascular smooth muscle cells proliferation and migration, possibly through inhibiting the phosphorylation of extracellular signal regulated kinase 1/2 and p38 pathway.

Giant orbital paramagnetism in toroidal carbon nanopeapods

The electronic structure and the magnetic response of toroidal carbon nanopeapods (TCNPs) are investigated within the sp(3) tight-binding formalism. It is found that in the presence of mirror symmetry, there exists a level crossing at the Fermi level in the energy spectrum of a TCNP, leading to giant orbital paramagnetism (GOP), in spite of the curvatures and hybridizations of the outer toroidal carbon nanotube (TCN). When the mirror symmetry is broken by rotating the inner C(60)s, however, two level crossings appear at the Fermi level, and the GOP changes into a very small diamagnetic response. The results reveal the GOP in a filled TCN, depending on the characteristics of the filling materials and temperature.

Odd-even width effect on persistent current in zigzag hexagonal graphene rings

The electronic structure and thus the persistent current of zigzag hexagonal graphene rings are investigated within the tight-binding formalism. The flux-dependent energy spectrum is grouped into bands with six levels per band due to inter-valley scattering at the corners of the ring. It is found that the degeneracy at the Fermi level is determined by the even or odd quality of the ring width N. The sample ring becomes metallic at odd N but semiconducting at even N, showing up a strange odd-even width effect. In metallic rings, the persistent current within a flux period is linearly changed with magnetic flux varphi, while it is a sinusoidal periodical function of varphi in semiconducting rings. In addition, with increasing N, the persistent current exponentially decreases (increases) at odd (even) N, but finally falls into the consistence with each other at enough large N, showing that the odd-even effect may be experimentally observable only in narrow rings.

Visible photon-avalanche upconversion in Ho3+ singly doped beta-Na(Y1.5Na0.5)F6 under 980 nm excitation

Visible IR-to-green photon-avalanche upconversion is reported in an Ho3+ singly doped beta-Na(Y1.5Na0.5)F6 crystal under 980 nm excitation. Upconverted green, red, and IR emissions are observed at 540, 645, and 751 nm, respectively. Temporal evolution and excitation power dependent upconversion intensity are measured, suggesting that a photon-avalanche mechanism is responsible for the upconversion process. It is believed that an efficient cross relaxation (5S2,5I8)-->(5I6,5I6) mainly performs the population of 5I6 excited state, resulting in the intense photon-avalanche upconversion emission in the synthesized samples.

Raman frequency shift in oxygen-functionalized carbon nanotubes

Based on density functional theory, the geometrical and electronic structures of oxygen-functionalized single-wall carbon nanotubes (O-SWCNs) are obtained, of which the vibrational properties are calculated in terms of lattice dynamics theory. Both bond expansion and contraction are found to coexist in O-SWCNs. A distinct Raman shift is observed in the radial breathing mode (RBM) and the G modes, depending not only on the tube diameter and chirality but also on oxygen coverage and adsorption configurations. With the oxygen coverage increasing, interestingly, a nonmonotonic upshift and downshift is observed in the G modes, which is attributed to the competition between the bond expansion and contraction. In addition, the resonance Raman effect at different oxygen coverage, which may be observable in O-SWCNs, is discussed.

Lattice Dynamics of Carbon Chain Inside a Carbon Nanotube

Based on the density functional theory, we obtain the optimum geometry of carbon chain inside a carbon nanotube. The phonon spectrum and specific heat of such a chain and nanotube hybrid system are calculated in terms of lattice dynamics theory. Some new phonon branches that have been obtained come from the coupling vibrations of the nanotube and the chain. The bending and stretching modes of the chain appear at about 520 cm(-1)and 1935 cm(-1) at Gamma point, respectively. It is found that the softening of G modes results mainly from the chain induced variations in the bond length on nanotube, independent of van der Waals interaction, while the stiffening of radial breathing mode is developed by the competition between the two factors. In the low-frequency region, the vibrational density of states are very different from that of the bare nanotube. Its specific heat implies the underlying quantized phonon structures and much large thermal conductivity in the hybrid system. In addition, the chain-length dependent vibration modes are calculated, from which it is expected that a finite chain of about 14 carbon atoms in the nanotube may produce the experimental Raman peak at about 1850 cm(-1).

Electronic structure of carbon nanotori: the roles of curvature, hybridization, and disorder

An efficient and reasonable procedure is proposed for calculating the electronic structure of carbon nanotori in terms of rotational symmetry, within the tight binding formalism. It is shown that the curvature induced σ(*)-π(*) hybridization effects play an important role in determining the electronic structure of this novel nanostructure. The energy gap of the carbon nanotorus exhibits a well defined oscillation feature with increasing size of the torus, converging to that of the corresponding infinite nanotube, while its density of states spectrum evolves from the characteristic of a zero dimensional system to that of a quasi-one dimensional system. Effects of disorder on the electronic properties are also discussed.

Liver ischemia contributes to early islet failure following intraportal transplantation: benefits of liver ischemic-preconditioning

Early graft failure following intraportal islet transplantation (IPIT) represents a major obstacle for successful islet transplantation. Here, we examined the role of islet emboli in the induction of early graft failure and utilized a strategy of ischemic-preconditioning (IP) to prevent early islet destruction in a model of syngeneic IPIT in STZ-induced diabetic mice. Numerous focal areas of liver necrosis associated with the islet emboli were observed within 24 h post-IPIT. Pro-inflammatory cytokines, IL-1beta and IL-6, were significantly increased 3 h after IPIT, while TNF-alpha was elevated for up to 5 days post-IPIT. Caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling positive cells were observed in the transplanted islets trapped in areas of necrotic liver at 3 h and 1 day post-IPIT. Hyperglycemia was corrected immediately following IPIT of 200 islets, but recurrence of hyperglycemia was observed within 14 days associated with a poor response to glucose challenge. IP, a procedure of pre-exposure of the liver to transient ischemia and reperfusion, protected the liver from embolism-induced ischemic injury and prevented early islet graft failure. These data suggest that islet embolism in the portal vein is a major cause of functional loss following IPIT that can be prevented by liver IP.

Activation of the novel prothrombinase, fg12, as a basis for the pregnancy complications spontaneous abortion and pre-eclampsia

PROBLEM

Impaired trophoblast invasion during the first trimester of pregnancy is linked to spontaneous abortion, and defective invasion in the second trimester to hypertension + proteinuria (pre-eclampsia). Hypertension developing during the third trimester of human pregnancy represents, in part, a corrective response in the mother to provide adequate placental perfusion for fetal growth when trophoblast has not to invaded and converted the myometrial porprtion of maternal spiral arteries into to low resistance-high capacitance conduits. Deportation of vesicles from hypoxemic trophoblast is thought to cause hypertension plus proteinuria, vascular damage and a systemic coagulopathy. Trophoblast invasion may be inhibited by local cytokines, such as TGF-betas but Thl-type cytokines associated with pre-eclapmsia and spontaneous abortions (e.g., IL-1, TNF-alpha, IFN-gamma) are not known to inhibit migration at in situ concentrations. Trophoblast invasion is also inhibited by the binding of surface integrins to fibronectin and fibrin, and fibrin production is stimulated by these Th1 cytokines via up-regulation of prothrombinases(s) such as fg12 which directly and via TNF-alpha-facilitated inflamation compromise trophoblast cell integrity. We, therefore, asked if fg12 expression and TNF-alpha are increased in first trimester human miscarriage and in third trimester pre-eclampsia.

METHODS

fg12 mRNA was detected using in situ hybridization and fg12 protein by immunohistochemistry. TNF-alpha mRNA and protein were similarly tested. The techniques were validated using uterine sections from day 8.5 of CBA x DBA/2 pregnancies, and then were applied to sections of placentae from normal and pre-eclamptic pregnancies with and without intrauterine fetal growth restriction (IUGR). Fibrin was detectectd by immunohistochemistry.

RESULTS

Expression of fg12 protein correlated with fg12 mRNA expression in mouse uteri and in placentae from normal human pregnancies. Increased expression of fg12 and TNF-alpha mRNA and protein, and increased fibrin deposition was detected in placental trophoblast.

CONCLUSIONS

Activation of fg12 prothrombinase by Th1-type cytokines in pregnancy may lead to spontaneous abortion, or in ongoing pregnancy, to pre-eclampsia and/or IUGR.

Fgl2 prothrombinase expression in mouse trophoblast and decidua triggers abortion but may be countered by OX-2

Spontaneous abortion of normal karyotype embryos in mice and in humans is associated with an increase in uterine T helper (Th) 1 type proinflammatory cytokines, tumour necrosis factor (TNF)-alpha, interferon-gamma and interleukin (IL)-1, and a deficiency of Th2/3 type cytokines, IL-4, IL-10, and transforming growth factor (TGF)-beta2. In mice, Th1 cytokines up-regulate a novel prothrombinase, fgl2, which via thrombin, leads to activation of polymorphonuclear leukocytes that terminate the pregnancy. Here we show that Th1 cytokines up-regulate fgl2 mRNA in fetal trophoblast and secondary decidua of CBA/JxDBA/2 and CBA/JxBALB/c matings, and promote fibrin deposition. This pattern is accompanied by a high rate of abortion. However, the spontaneous abortion rates in abortion-prone CBAxDBA/2 matings and in low abortion rate CBAxBALB/c matings were significantly lower than that expected from the frequency of implantations with high levels of fibrin and fgl2 mRNA(hi). As the glycoprotein OX-2 occurs in the pregnant rat uterus and can deviate cytokine responses to Th2/3, we investigated OX-2 in pregnant CBA/J mice. We found OX-2 mRNA was present at the same sites as fgl2 mRNA, but was reduced in response to Th1 cytokines. Furthermore, anti-OX-2 raised the abortion rate to predicted levels, while recombinant OX-2 dramatically reduced the abortion rate. Fgl2 prothrombinase may provide a mechanism explaining pregnancy loss, and conversely, successful pregnancy may be due in part to OX-2-dependent activation of maternal tolerance mechanisms at the feto-maternal interface.

The emerging role of immunoregulation of fibrinogen-related procoagulant Fgl2 in the success or spontaneous abortion of early pregnancy in mice and humans

PROBLEM

Abortion of chromosomally normal embryos in the CBA X DBA/2 mating combination is triggered by release of Th1 cytokines (tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma, and interleukin [IL]-1), which cause abortion via a novel prothrombinase, Fgl2, and polymorphonuclear leukocytes. The site of activation may be maternal vascular endothelium on arteries and veins nourishing the placenta. Activation of coagulation is also prominent in spontaneous abortion of chromosomally normal human embryos. We asked where is Fgl2 up-regulated in the uterus in murine abortions, and if similar Fgl2 expression occurs in human pregnancy failure.

METHODS

Control CBA X DBA/2 pregnant mice, or from mice injected with TNF-alpha + IFN-gamma on day 7.5 of gestation, were removed on day 8.5, fixed, sectioned, and subject to in situ hybridization for Fgl2. Sections were also stained for fibrin. Elective first trimester termination samples or biopsies taken early in the course of a recurrent miscarriage were similarly fixed, sectioned, and analyzed by in situ hybridization. Control and cytokine-treated mice were anticoagulated with heparin, an activator of antithrombin III, and/or the direct anti-thrombin inhibitor hirudin.

RESULTS

Low level Fgl2 expression localized to basal decidua remote from the embryo was noted in control mice; cytokine treatment, which causes greater than 80% of abortions, produced a striking up-regulation in this area as well as in a band at the junction of decidua and myometrium. Trophoblast also became strikingly positive. Fgl2 expression was associated with increased fibrin staining. Anticoagulation significantly protected against abortions, but doses were limited by the complication of retroplacental hemorrhage. In tissue from normal first trimester pregnancy, minimal Fgl2 positivity was seen in some villous syncytiotrophoblast, in villous stroma, cytotrophoblast, and in some cells in decidua. In spontaneous abortion of normal embryo, striking Fgl2 positivity was seen in syncytiotrophoblast and extravillous cytotrophoblast, in association with areas of thrombus formation.

CONCLUSIONS

Fgl2 appears to be physiologically expressed and may protect against the internal danger of maternal and/or fetal bleeding during pregnancy and at parturition; a role in inhibiting transplacental traffic is also possible. External dangers in the form of stress, endotoxin, and antigens eliciting Th1 cytokine responses upregulate Fgl2 prothrombinase in trophoblast as well as in decidua, which results in spontaneous abortion of immunogenetically "weaker" embryos.

Expression of the fgl2 and its protein product (prothrombinase) in tissues during murine hepatitis virus strain-3 (MHV-3) infection

Murine Hepatitis Virus Strain 3 (MHV-3) produces fulminant hepatitis with 80-90% mortality in Balb/cJ mice. Previous studies in our laboratory have shown that peritoneal macrophages from MHV-3 infected mice produce a procoagulant (PCA) which has the ability to cleave prothrombin to thrombin (prothrombinase) encoded by the gene fgl2 located on chromosome 5. PCA accounts for sinusoidal thrombosis and hepatic necrosis and the necrosis and mortality can be prevented by treatment of animals with a monoclonal antibody to PCA. These present studies were designed to examine the expression of this gene (mRNA by Northern analysis and in situ hybridization) and the gene product PCA (immunochemistry) in tissues recovered from MHV-3 infected Balb/cJ mice in an attempt to explain the liver specific nature of MHV-3 disease. Fgl2 gene expression was detected as early as 8 hours after MHV-3 infection which persisted to 48 hours in the liver, spleen and lungs whereas no gene expression was seen in the brain or kidneys despite the fact that equivalent viral titers were detected in all tissues at all times. In the liver, fgl2 gene expression was confined to endothelial and Kupffer cells with no expression in hepatocytes. Immunochemistry localized the PCA protein to Kupffer cells and endothelial cells and necrotic foci within the liver. No PCA protein was detected by immunochemistry in any other tissues at any time during the course of MHV-3 infection. These results explain the liver specific nature (fulminant hepatitis) of MHV-3 infection and provides further evidence for the role of PCA in the pathogenesis of fulminant hepatitis. MHV-3 induces selective transcription of the gene fgl2 and only hepatic reticuloendothelial cells produce functional protein (PCA) which is known to account for fulminant hepatic failure produced by MHV-3.

Resistance of naive mice to murine hepatitis virus strain 3 requires development of a Th1, but not a Th2, response, whereas pre-existing antibody partially protects against primary infection

Murine hepatitis virus strain 3 (MHV-3) produces a host-strain-dependent spectrum of disease. The development of liver necrosis has been shown to be related to production of a unique macrophage procoagulant activity (PCA), encoded by the gene fgl-2, in susceptible mice. These studies were designed to examine the influence of Th1/Th2 cells on resistance/susceptibility and production of macrophage procoagulant activity (PCA) in resistant (A/J) and susceptible (Balb/cJ) strains of mice following infection with MHV-3. Immunization of A/J mice with MHV-3 induced a Th1 cellular immune response and one Th1 cell line (3F9.1) protected susceptible mice and inhibited production of PCA by macrophages both in vitro and in vivo. In contrast, immunization of Balb/cJ mice with an attenuated variant of MHV-3 derived from passaging MHV-3 in YAC-1 cells resulted in a Th2 response. Transfer of spleen cells and T cell lines from immunized Balb/cJ mice failed to protect naive susceptible syngeneic mice from infection with MHV-3 and augmented production of IL-1 beta, TNF-alpha and PCA by macrophages to MHV-3 in vitro. Serum from immunized Balb/cJ mice contained high titered neutralizing antibody which protected naive Balb/cJ animals from lethal primary MHV-3 infection. These results demonstrate that susceptible Balb/cJ mice generate a Th2 response following MHV-3 infection and that these Th2 cells neither inhibit MHV-3-induced macrophage PCA production nor protect naive mice from MHV-3 infection. The results suggest that antibody protects against primary infection, but could not eradicate ongoing infection. Ribavirin, a synthetic guanosine analogue prolonged survival to MHV-3 infection, inhibited production and transcription of the macrophage pro-inflammatory cytokines IL-1 beta and TNF-alpha and Th2 cytokines while preserving Th1 cytokine production. Thus, this data defines the differential role of Th1/Th2 lymphocytes in primary and secondary MHV-3 infection and further defines the importance of macrophage inflammatory mediators in the pathogenesis of MHV-3 infection.

Resistance to murine hepatitis virus strain 3 is dependent on production of nitric oxide

The strain-specific spectrum of liver disease following murine hepatitis virus type 3 (MHV-3) infection is dependent on inflammatory mediators released by macrophages. Production of nitric oxide (NO) by macrophages has been implicated in resistance to a number of viruses, including ectromelia virus, vaccinia virus, and herpes simplex virus type 1. This study was undertaken to define the role of NO in MHV-3 infection. Gamma interferon-induced production of NO inhibited growth of MHV-3 in a murine macrophage cell line (RAW 264.7). Viral inhibitory activity was reproduced by the NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP), whereas N-acetyl-DL-pencillamine (NAP), an inactive analog of SNAP, had no effect. Electron microscopy studies confirmed the inhibitory effects of NO on viral replication. Peritoneal macrophages isolated from A/J mice known to be resistant to MHV-3 produced a fivefold-higher level of NO and higher levels of mRNA transcripts of inducible NO synthase in response to gamma interferon than macrophages from susceptible BALB/cJ mice. SNAP inhibited growth of MHV-3 in macrophages from both strains of mice to similar degrees. In vivo inhibition of NO by N-monomethyl-L-arginine resulted in loss of resistance to MHV-3 in A/J mice. These results collectively demonstrate a defect in the production of NO in macrophages from susceptible BALB/cJ mice and define the importance of endogenous NO in resistance to MHV-3 infection in resistant A/J mice.

Ribavirin inhibits viral-induced macrophage production of TNF, IL-1, the procoagulant fgl2 prothrombinase and preserves Th1 cytokine production but inhibits Th2 cytokine response

Ribavirin, a synthetic guanosine analogue, possesses a broad spectrum of activity against DNA and RNA viruses. It has been previously shown to attenuate the course of fulminant hepatitis in mice produced by murine hepatitis virus strain 3. We therefore studied the effects of ribavirin on murine hepatitis virus strain 3 replication, macrophage production of proinflammatory mediators including TNF, IL-1, and the procoagulant activity (PCA), fgl2 prothrombinase; and Th1/Th2 cytokine production. Although ribavirin had inhibitory effects on viral replication (<1 log), even at high concentrations complete eradication of the virus was not seen. In contrast, at physiologic concentrations (up to 500 microg/ml), ribavirin markedly reduced viral-induced parameters of macrophage activation. With ribavirin treatment, the concentrations of PCA, TNF-alpha and IL-1beta all decreased to basal concentrations: PCA from 941 +/- 80 to 34 +/- 11 mU/10(6) cells; TNF-alpha from 10.73 +/- 2.15 to 2.74 +/- 0.93 ng/ml; and IL-1beta from 155.91 +/- 22.62 to 5.74 +/- 0.70 pg/ml. The inhibitory effects of ribavirin were at the level of gene transcription as evidenced by Northern analysis. Both in vitro and in vivo, ribavirin inhibited the production of IL-4 by Th2 cells, whereas it did not diminish the production of IFN-gamma in Th1 cells. In contrast, ribavirin had no inhibitory effect on TNF-alpha and IL-1beta production in LPS-stimulated macrophages. These results suggest that the beneficial effects of ribavirin are mediated by inhibition of induction of macrophage proinflammatory cytokines and Th2 cytokines while preserving Th1 cytokines.

Inhibition of amiloride-sensitive sodium-channel activity in distal lung epithelial cells by nitric oxide

Distal lung epithelial cells (DLECs) play an active role in fluid clearance from the alveolus by virtue of their ability to actively transport Na+ from the alveolus to the interstitial space. The present study evaluated the ability of activated macrophages to modulate the bioelectric properties of DLECs. Low numbers of lipopolysaccharide (LPS)-treated macrophages were able to significantly reduce amiloride-sensitive short-circuit current (Isc) without affecting total Isc or monolayer resistance. This was associated with a rise in the flufenamic acid-sensitive component of the Isc. The effect was reversed by the addition of N-monomethyl-L-arginine to the medium, implying a role for nitric oxide. We hypothesized that macrophages exerted their effect by expressing inducible nitric oxide synthase (iNOS) in DLECs. The products of LPS-treated macrophages increased the levels of iNOS protein and mRNA transcripts in DLECs as well as causing a rise in iNOS activity. Immunofluorescence microscopy of LPS-stimulated macrophage-DLEC cocultures with anti-nitrotyrosine antibodies provided evidence for the generation of peroxynitrite in macrophages but not in DLECs. These data indicate that activated macrophages in the lung may contribute to impaired resolution of acute respiratory distress syndrome and suggest a novel mechanism whereby nitric oxide might alter cell function by altering its ion-transporting phenotype.

Fulminant hepatic failure in murine hepatitis virus strain 3 infection: tissue-specific expression of a novel fgl2 prothrombinase

Activation of the immune coagulation system has been implicated in the pathogenesis of fulminant liver failure caused by murine hepatitis virus strain 3 (MHV-3). The recent discovery of the fgl2 gene, which encodes for MHV-3-induced prothrombinase (fgl2 prothrombinase), allows for fundamental studies to determine the molecular basis for fulminant liver failure. Transcription of the fgl2 gene and translation of the protein it encodes were examined in the liver and other organs of susceptible mice following MHV-3 infection. No constitutive expression of the fgl2 gene or the fgl2 prothrombinase was detected. Within 12 to 24 h of MHV-3 infection, however, fgl2 gene transcripts were detected in large amounts in the liver, spleen, and lungs, all of which are rich in reticuloendothelial cells, but were only focally present in small amounts in the kidney and brain. There was sequential detection of fgl2 prothrombinase in the liver, where it was localized specifically to the endothelium of intrahepatic veins and hepatic sinusoids; this was allowed by fibrin deposition, which resulted in confluent hepatocellular necrosis. These results provide further evidence for the role of the selective expression of this novel fgl2 prothrombinase in the pathogenesis of MHV-3-induced fulminant liver failure.

Function of reduced-size liver transplant in the rat

We have studied the function of partial orthotopic liver transplantation in the rat by evaluating prothrombin time (PT), liver blood flow, basal and glucose-stimulated insulin secretion and glucose tolerance, and the reticuloendothelial function (RES) in hepatectomized rats subjected to partial liver transplantation. A graft corresponding to 68% of a normal liver was transplanted to totally hepatectomized rats. Comparison was made between control rats and rats subjected to 32% liver resection. PT was not significantly different in the transplanted group compared with liver-resected and control rats. Laser Doppler flowmetry showed that at 28 days after surgery, blood flow had increased in the transplanted livers. Furthermore, on the third day after transplantation, basal plasma insulin was increased and the plasma insulin response to glucose was exaggerated, suggesting reduced insulin action and impaired insulin degradation. Finally, uptake of radioactive-labeled E. coli bacteria, as a measure of RES function, was not compromised in transplanted animals. Based on these results, we conclude that reduced-size liver transplant in out-bred rats results in fast normalization of liver function after surgery although, immediately after surgery, glucose intolerance is seen.

Effect of bile obstruction on liver regeneration following major hepatectomy: an experimental study in the rat

The regeneration of the liver following resection is regulated by a variety of factors and it might be expected that jaundice influences the process. We therefore evaluated the regenerative response to major hepatectomy in bile-obstructed rats. Two weeks after ligation of the common bile duct, a standardized 77% hepatectomy was undertaken. The jaundiced animals showed an augmented liver regeneration compared to nonjaundiced individuals (p < 0.01). However, blood clearance of radiolabelled Escherichia coli bacteria was impaired (p < 0.01) in animals with bile obstruction at 7 days after the hepatectomy, accompanied by reduced bacterial uptake in the liver as a sign of impaired reticuloendothelial system function.

Enhanced Kupffer cell activity after repeated hepatic arterial ischaemia in an experimental model

Kupffer cells are important for host defence against both foreign invaders and neoplasia. Several studies have demonstrated that ischaemia and reperfusion activates Kupffer cells. The effect of hepatic arterial ischaemia on Kupffer cell function was assessed using blood clearance and organ uptake of radiolabelled Escherichia coli. Transient ischaemia for 1 h did not alter Kupffer cell function in comparison with sham operation. However, prolonging arterial ischaemia for 2 h stimulated Kupffer cell function; both the phagocytic index and liver uptake of radiolabelled E. coli increased significantly (P < 0.01). Furthermore, this enhanced Kupffer cell activity was achieved each time the ischaemia was induced over a period of 5 days compared with repeated sham procedures (P < 0.05). Serum tumour necrosis factor (TNF) was significantly released after both single and repeated arterial occlusion for 2 h (P < 0.01). These observations show that transient arterial ischaemia enhances Kupffer cell function and induces TNF production.

Macrophage phagocytic dysfunction and reduced metabolic response in experimental obstructive jaundice

OBJECTIVE

To investigate the metabolic response as measured by microcalorimetry and the phagocytic activity or peritoneal macrophages that had been harvested from jaundiced and normal rats and incubated with Escherichia coli in vitro.

DESIGN

Open laboratory study.

SETTING

University departments of surgery and immunology.

MATERIAL

12 Male Sprague-Dawley rats.

INTERVENTIONS

Ligation and transsection of the common bile duct (n = 6) or sham operation (n = 6).

MAIN OUTCOME MEASURES

Metabolic response (pW/cell) measured by microcalorimetry and phagocytic function assessed by light microscopy after Giemsa stain two weeks after operation.

RESULTS

The mean (SEM) maximal metabolic response of macrophages and the metabolic rate one hour after inoculation with E coli were significantly reduced in jaundiced rats compared with controls (6.95 (1.95) compared with 27.39 (7.24), p = 0.005, and 5.50 (1.05) compared with 20.10 (3.35) p = 0.016, respectively) as were the number of E coli phagocytosed by macrophages harvested from jaundiced animals (p = 0.0002).

CONCLUSION

The reduced metabolic response and phagocytosis of E coli by peritoneal macrophages in rats by biliary obstruction is a sign of depressed reticuloendothelial function. This mechanism may explain the high incidence of infective complications inpatients with obstructive jaundice.

Obstructive jaundice impairs reticuloendothelial function and promotes bacterial translocation in the rat

Septic complications and renal insufficiency following biliary tract surgery are frequently seen in patients with obstructive jaundice. The precise mechanisms for understanding the susceptibility of the jaundiced patients to sepsis are, however, not clear. The present study aimed at investigating the influence of biliary obstruction on the reticuloendothelial function and bacterial translocation at various time intervals in the rat. Reticuloendothelial system (RES) function, as evaluated by measuring blood clearance of intravenously injected 125I-labeled Escherichia coli, and bacterial translocation were studied 3 days and 1, 2, and 3 weeks following either sham operation or common bile duct ligation (CBDL) and transection in the rat. RES function was significantly impaired and renal uptake of radiolabeled E. coli was significantly higher in jaundiced animals from Day 3 and on after CBDL (P < 0.01) concomitant with elevation of plasma levels of bilirubin and liver enzymes (P < 0.001) compared with their corresponding controls. The incidence of bacterial translocation 3 days and 1 and 2 weeks after biliary obstruction significantly increased (P < 0.05). We conclude that RES phagocytic function is impaired and the incidence of bacterial translocation is increased in jaundiced rats. These findings might contribute to explain the high susceptibility of postoperative septic complications and renal dysfunction in patients with obstructive jaundice.

Abdominal rubber drain piece aggravates intra-abdominal sepsis in the rat

Biomaterials in the peritoneal cavity disrupt the physiology of the host and may cause bacterial translocation. The current study was performed to determine whether biomaterials exacerbate intra-abdominal infections. Adult male rats were divided into four groups: group 1, celiotomy+intraperitoneal (i.p.) saline; group 2, celiotomy+i.p. Escherichia coli (3 x 10(8) cfu); group 3, i.p. rubber+i.p. saline; and group 4, i.p. rubber+i.p. E. coli (3 x 10(8) cfu). Twelve h after the challenge, enteric bacterial translocation, bacterial population levels in the cecum and serum levels of IL-6 and TNF were measured. Bacterial translocation to mesenteric lymph nodes and the liver was observed in animals from groups 2 and 3, but significantly increased in group 4 with a concomitant elevation of serum levels of TNF and IL-6, as compared with group 1. Histological examination revealed a more pronounced inflammatory reaction in the peritoneum and distal ileum in group 4 than in groups 2 and 3. These results suggest that the presence of rubbers in the peritoneal cavity aggravates intra-abdominal sepsis.

Inhibition of bacterial translocation in obstructive jaundice by muramyl tripeptide phosphatidylethanolamine in the rat

Obstructive jaundice is frequently associated with septic complications and enteric bacteria have been isolated from both the infectious focus and bile in jaundiced patients. The present study aimed to evaluate bacterial translocation and the influence of a macrophage-stimulant (muramyl tripeptide phosphatidylethanolamine) on bacterial translocation in obstructive jaundice. Male Sprague-Dawley rats were subjected to sham operation (n = 10) or common bile-duct ligation and transection (n = 35). Two weeks later, jaundiced animals received either physiological saline (n = 15), muramyl tripeptide phosphatidylethanolamine liposomes (n = 10) or placebo (empty) liposomes (n = 10) orally, while sham-operated rats received physiological saline, 48 h prior to evaluation of enteric bacterial translocation. Blood, bile and caecal contents were collected and cultured aerobically and anaerobically, as were tissue samples from the liver, spleen and mesenteric lymph nodes. Positive mesenteric lymph node cultures in animals with jaundice + saline (7/15; 47%) and jaundice + placebo liposomes (4/10; 40%) significantly differed (p < 0.05) from sham-operated animals (1/10; 10%) and muramyl tripeptide phosphatidylethanolamine treated animals (0/10). Caecal counts (CFU/g) of Escherichia coli, Lactobacilli and aerobic and microaerobic bacteria did not differ statistically among the groups, although the number of E. coli tended to be higher in jaundiced animals. Thus, liposomal muramyl tripeptide phosphatidylethanolamine inhibits bacterial translocation, probably by activating mucosal macrophages and enhancing reticuloendothelial system function in rats with biliary obstruction.

Modification of reticuloendothelial function by muramyl dipeptide-encapsulated liposomes in jaundiced rats treated with biliary decompression

Rats with 2 weeks of biliary obstruction, with and without 1 week of concomitant biliary decompression relieving the jaundice, were treated with physiologic saline, free muramyl dipeptide (MDP), placebo liposomes, or liposome-encapsulated MDP. Reticuloendothelial system (RES) function was evaluated by blood clearance of intravenously injected 125I-labelled Escherichia coli. The corrected phagocytic index (alpha) after 1 week of biliary decompression returned to normal levels in animals treated with MDP liposomes, whereas RES function was impaired (P < 0.05) in all other jaundiced and biliary-decompressed groups. In the biliary-decompressed, MDP-liposome-treated group, hepatic uptake of radiolabelled bacteria was significantly higher (P < 0.05) and renal entrapment of bacteria was significantly lower (P < 0.05) than in all other jaundiced and biliary-decompressed groups. We conclude that treatment with MDP liposomes improves the otherwise impaired RES function in rats with biliary obstruction and biliary decompression.

The role of bile and bile acids in bacterial translocation in obstructive jaundice in rats

Male Sprague-Dawley rats were randomly divided into five groups in which group 1 received a sham operation (controls), groups 2-5 underwent common bile duct ligation and transection 14 days before the experiments. Two days prior to the studies, animals in groups 1 and 2 received saline orally, while groups 3-5 received an oral administration of either cholic acid, deoxycholic acid or whole bile. Specimens were taken for bacterial culture, and blood was collected for endotoxin assay. The rate of positive bacterial cultures from mesenteric lymph nodes in jaundiced saline-treated animals was significantly higher (p < 0.05) as compared with both controls and the other jaundiced animals treated with either bile or bile acids. Assays were positive for endotoxin in the jaundiced saline-treated group, whereas they were negative in both controls and bile- or bile-acid-treated animals. We conclude that oral administration of cholic acid, deoxycholic acid or whole bile inhibited bacterial translocation and endotoxin absorption in obstructive jaundice in the rat.

The effect of biliary decompression on bacterial translocation in jaundiced rats

Patients with obstructive jaundice are prone to septic complications after biliary tract operations. Restoring bile flow to the intestine may help to decrease the complication rate. The present study is aimed at evaluating the effect of biliary decompression on bacterial translocation in jaundiced rats. Sixty-six male Sprague-Dawley rats were randomly allocated to six groups subjected to common bile duct ligation (CBDL) and transection (groups 2-6) or sham operation (group 1). In groups 1 and 2 the incidence of enteric bacterial translocation was determined 2 weeks after sham operation or CBDL. In groups 3-6, biliary decompression was achieved by performing a choledochoduodenostomy after 2 weeks of biliary decompression. Bacterial translocation was then studied 1, 2, 3 and 5 weeks following biliary decompression. The rate of bacterial translocation to mesenteric lymph nodes in obstructive jaundice was significantly higher as compared with controls and decreased with time to nil three weeks following biliary decompression. The incidence of bacterial translocation was closely correlated (r = 0.844; p = 0.034) with serum alkaline phosphatase activity and seemed to fit with the morphological changes noted in the small intestine. The decrease in bacterial translocation, however, lags behind the recovery of liver function as measured by routine liver function tests and antipyrine clearance. Obstructive jaundice thus promotes bacterial translocation in the rat. Biliary decompression gradually decreases the rate of bacterial translocation.

Effect of biliary decompression on reticuloendothelial function in jaundiced rats

The recovery of reticuloendothelial system (RES) function following decompression of obstructive jaundice was studied using a rat model with bile duct ligation and side-to-side choledochoduodenostomy. Histopathological changes in the liver were still present 5 weeks after relief of jaundice, while results of liver function tests had returned to normal. RES function evaluated by the blood clearance and organ uptake of radiolabelled Escherichia coli using a corrected phagocytic index gradually returned to normal following biliary decompression. The severely impaired RES activity noted 1 week after operation may explain the increased incidence of sepsis and renal insufficiency in the early period after biliary surgery in jaundiced patients.

The influence of biliary obstruction and sepsis on reticuloendothelial function in rats

Obstructive jaundice is frequently associated with septic complications and renal impairment. The present study was performed in order to evaluate reticuloendothelial system (RES) function in obstructive jaundice and the influence of a septic challenge. Male Sprague-Dawley rats were allocated into four groups (laparotomy alone, caecal ligation and puncture (CLP), ligation of the common bile duct (CBD) alone and CBD+CLP, respectively). Mortality, blood clearance and organ distribution of 125I labelled Escherichia coli were determined. Mortality in sepsis (CLP) significantly increased in jaundiced animals (p less than 0.033). Blood clearance of radiolabelled E. coli was significantly impaired in both jaundiced groups. In jaundiced animals, hepatic localisation and renal uptake of E. coli significantly increased (p less than 0.001), while radioactive counts in bile significantly decreased (p less than 0.01). Changes in organ distribution of bacteria did not depend on alterations in blood flow. Thus, RES function was impaired in jaundiced animals and mortality increased in a concomitant septic challenge in jaundiced animals.

Pharmacokinetics of mitomycin C following hepatic arterial chemoembolization with gelfoam

Twelve mongrel dogs were randomly allocated into two groups using matched paired-design. Catheters were inserted into the hepatic artery, hepatic vein and the femoral vein, respectively. In the first group, gelfoam supplemented with mitomycin C (MMC) was injected into the hepatic artery, whereas the second group received a hepatic arterial injection of MMC solution alone. Simultaneous blood sampling from the hepatic and femoral vein at regular intervals was performed. MMC concentrations in plasma was determined using high performance liquid chromatography (HPLC) and the pharmacokinetics of MMC were determined. MMC concentrations in hepatic and femoral veins did not differ and no significant difference in pharmacokinetics was found when comparing MMC administration into the hepatic artery with or without gelfoam supplementation. Thus, our results revealed that gelfoam could not delay the clearance of MMC from the liver.