[Preliminary clinical application of novel magnetic navigation and ultrasound-guided percutaneous transhepatic cholangiography drainage through the right liver duct for malignant obstructive jaundice]

Objective: To analyze the clinical application value of a novel magnetic navigation ultrasound (MNU) combined with digital subtraction angiography (DSA) dual-guided percutaneous transhepatic biliary drainage (PTCD) through the right hepatic duct for the treatment of malignant obstructive jaundice. Methods: Randomized controlled trial. The clinical data of 64 patients with malignant obstructive jaundice requiring PTCD through the right hepatic duct at the Hepatobiliary Center of the First Affiliated Hospital of Nanjing Medical University (Jiangsu Province People's Hospital) from December 2018 to December 2021 were retrospectively analyzed. The MNU group (n=32) underwent puncture guided by a novel domestic MNU combined with DSA, and the control group (n=32) underwent puncture guided by traditional DSA. The operation time, number of punctures, X-ray dose after biliary stenting as shown by DSA, patients' tolerance of the operation, success rate of the operation, pre- and post-operative total bilirubin, and incidence of postoperative complications were compared between the two groups. Results: The operation time of the MNU group was significantly shorter than that of the control group [(17.8±7.3) vs. (31.6±9.9) min, t=-6.35,P=0.001]; the number of punctures in the MNU group was significantly lower [(1.7±0.6) vs. (6.3±3.9) times, t=-6.59, P=0.001]; and the X-ray dose after biliary stenting as shown by DSA in the MNU group was lower than that in the control group [(132±88) vs. (746±187) mGy, t=-16.81,P<0.001]; Five patients in the control group were unable to tolerate the operation, and two stopped the operation, however all patients in the MNU group could tolerate the operation, and all completed the operation, with a success rate of 100% (32/32) in the MNU group compared to 93.8%(30/32) in the control group; the common complications of PTCD were biliary bleeding and infection, and the incidence of biliary bleeding (25.0%, 8/32) and infection (18.8%, 6/32) in the MNU group was significantly lower than that in the control group, 53.1% (17/32) and 28.1% (9/32), respectively. Conclusion: Magnetic navigation ultrasound combined with DSA dual-guided PTCD through the right biliary system for the treatment of malignant obstructive jaundice is safe and feasible.

[Application of pretrained model based on electronic medical record in recognition of acute respiratory infection]

Objective: To evaluate the recognition of acute respiratory infection (ARI) by a pretrained model based on electronic medical records (EMRs). Methods: 38 581 EMRs were obtained from Chongqing University Three Gorges Hospital in December 2021. Bidirectional encoder representation from transformers (BERT) pretrained model was used to identify ARI in EMRs. The results of medical professionals were considered as the gold standard to calculate the sensitivity, specificity, Kappa value, and area under the curve of the receiver operating characteristic (AUC). Results: There were 3 817 EMRs in the test set, with 1 200 ARIs. A total of 1 205 cases were determined as ARI by the model, with a sensitivity of 92.67% (1 112/1 200) and a specificity of 96.45% (2 524/2 617). The model identified ARI with similar accuracy in males and females (AUCs 0.95 and 0.94, respectively), and was more accurate in identifying ARI cases in those aged less than 18 than in adults 18-59 and adults 60 and older (AUCs 0.94, 0.89 and 0.94, respectively). The current model had a better identification of ARIs in outpatient patients than that in hospitalized patients, with AUCs of 0.74 and 0.95, respectively. Conclusion: The use of the BERT pretrained model based on EMRs has a good performance in the recognition of ARI cases, especially for the outpatients and juveniles. It shows a great potential to be applied to the monitoring of ARI cases in medical institutions.

Multi-cancer early detection test sensitivity for cancers with and without current population-level screening options

There are four solid tumors with common screening options in the average-risk population aged 21 to 75 years (breast, cervical, colorectal, and, based on personalized risk assessment, prostate), but many cancers lack recommended population screening and are often detected at advanced stages when mortality is high. Blood-based multi-cancer early detection tests have the potential to improve cancer mortality through additional population screening. Reported here is a post-hoc analysis from the third Circulating Cell-free Genome Atlas substudy to examine multi-cancer early detection test performance in solid tumors with and without population screening recommendations and in hematologic malignancies. Participants with cancer in the third Circulating Cell-free Genome Atlas substudy analysis were split into three subgroups: solid screened tumors (breast, cervical, colorectal, prostate), solid unscreened tumors, and hematologic malignancies. In this post hoc analysis, sensitivity is reported for each subgroup across all ages and those aged ⩾50 years overall, by cancer, and by clinical cancer stage. Aggregate sensitivity in the solid screened, solid unscreened, and hematologic malignancy subgroups was 34%, 66%, and 55% across all cancer stages, respectively; restricting to participants aged ⩾50 years showed similar aggregate sensitivity. Aggregate sensitivity was 27%, 53%, and 60% across stages I to III, respectively. Within the solid unscreened subgroup, aggregate sensitivity was >75% in 8/18 cancers (44%) and >50% in 13/18 (72%). This multi-cancer early detection test detected cancer signals at high (>75%) sensitivity for multiple cancers without existing population screening recommendations, suggesting its potential to complement recommended screening programs.

Clinical trial identifier: NCT02889978.

[Efficacy and safety of neoadjuvant immunotherapy for hepatocellular carcinoma]

Objective: To study the surgical safety and efficacy of preoperative neoadjuvant therapy with immune checkpoint inhibitors combined with anti-angiogenic drugs in patients with China liver cancer staging(CNLC)-Ⅱb and Ⅲa resectable hepatocellular carcinoma. Methods: The data of 129 patients with Ⅱb and Ⅲa hepatocellular carcinoma who underwent surgery at the First Affiliated Hospital of Nanjing Medical University from January 2018 to December 2020 were analyzed. All patients were divided into two groups: the neoadjuvant therapy group(n=14,13 males and 1 female,aged (55.4±12.6)years(range:34 to 75 years)) received immune combined targeted therapy before surgery,immune checkpoint inhibitor camrelizumab was administered intravenously at a dose of 200 mg each time,every 2 weeks for 3 cycles,anti-angiogenesis drug apatinib was taken orally and continuously with a dose of 250 mg for 3 weeks and the conventional surgery group(n=115,103 males and 12 females,aged (55.8±12.0)years(range:21 to 83 years)) did not receive antitumor systemic therapy before surgery. There were 3 patients with CNLC-Ⅱb,11 with CNLC-Ⅲa in the neoadjuvant group;28 patients with CNLC-Ⅱb,87 with CNLC-Ⅲa in the conventional group. Student's t test or rank-sum test was used to compare the differences between two groups for quantitative data, Fisher's exact probability method was used to compare the differences of proportions between two groups, and Log-rank test was used to compare survival differences between two groups. Results: The 1-year recurrence rate in the neoadjuvant group was 42.9%,and the 1-year recurrence rate in the conventional group was 64.0%,with a statistically significant difference between the two groups(χ²=3.850,P=0.050);The 1-year survival rate in the neoadjuvant group was 100% and that in the conventional group was 74.2%,with a statistically significant difference between the two groups(χ²=5.170,P=0.023). According to the stratified analysis of the number of tumors,for single tumor,the 1-year recurrence rate in the neoadjuvant group was 25.0%,and that in the conventional surgery group was 71.0%,and the difference between the two groups was statistically significant(χ²=5.280, P=0.022). For multiple tumors, the 1-year recurrence rate in the neoadjuvant group was 66.7%,and the 1-year recurrence rate in the conventional surgery group was 58.9%,with no significant difference between the two groups(χ²=0.110,P=0.736). The operative time,intraoperative blood loss,and postoperative hospital stay in the neoadjuvant group were similar to those in the conventional group,and their differences were not statistically significant. Conclusions: Immune checkpoint inhibitors combined with anti-angiogenic targeted drugs as a neoadjuvant therapy for resectable hepatocellular carcinoma can reduce the 1-year recurrence rate and improve the 1-year survival rate,especially for those with solitary tumor. Limited by the sample size of the neoadjuvant group,the safety of immune combined targeted therapy before surgery cannot be observed more comprehensively,and further studies will be explored.

Recent advances in the diagnosis and management of amyloid cardiomyopathy

Amyloidosis is a disorder characterized by misfolded precursor proteins that form depositions of fibrillar aggregates with an abnormal cross-beta-sheet conformation, known as amyloid, in the extracellular space of several tissues. Although there are more than 30 known amyloidogenic proteins, both hereditary and non-hereditary, cardiac amyloidosis (CA) typically arises from either misfolded transthyretin (ATTR amyloidosis) or immunoglobulin light-chain aggregation (AL amyloidosis). Its prevalence is more common than previously thought, especially among patients with heart failure and preserved ejection fraction (HFpEF) and aortic stenosis. If there is a clinical suspicion of CA, focused echocardiography, laboratory screening for the presence of a monoclonal protein (serum and urinary electrophoresis with immunofixation and serum free light-chain ratio), and cardiac scintigraphy with 99mtechnetium-labeled bone-tracers are sensitive and specific initial diagnostic tests. In some cases, more advanced/invasive techniques are necessary and, in the last several years, treatment options for both AL CA and ATTR CA have rapidly expanded. It is important to note that the aims of therapy are different. Systemic AL amyloidosis requires treatment targeted against the abnormal plasma cell clone, whereas therapy for ATTR CA must be targeted to the production and stabilization of the TTR molecule. It is likely that a multistep treatment approach will be optimal for both AL CA and ATTR CA. Additionally, treatment of CA includes the management of restrictive cardiomyopathy with preserved or reduced ejection fraction in addition to treating the amyloid deposition. Future studies are necessary to define optimal management strategies for AL CA and ATTR CA and confirm cardiac response to therapy.

Abstract 940: Global Analysis of Histone Modifications and Long-range Chromatin Interactions Revealed the Differential Cistrome Changes and Novel Transcriptional Players in Dilated Cardiomyopathy

Background: Acetylation and methylation of histone alter the chromatin structure and accessibility that allows or prevents transcriptional regulators to bind to enhancers or promoters. The binding of transcriptional regulators enables the interaction between enhancers and promoters, thus affecting gene expression. However, our knowledge on the regulation of promoter and enhancer interactions and histone modifications in patients with heart failure remains limited.

Methods and Results: We performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) for major histone modifications and proximity ligation-assisted ChIP-seq (PLAC-seq) for long-range chromatin interaction for enhancer and promoter (E-P) using left ventricular tissues from dilated cardiomyopathy (DCM) patients and non-heart failure (NF) donors (n=2-3). We detected 37,531, and 8,587 differential H3K27ac and H3K4me3 regions between NF and DCM respectively (FDR <0.05). While the average read density (ARD) for H3K27ac, an active enhancer histone mark, is similar between NF and DCM, we observed the ARD of H3K4me3, which marks the active promoter region of the genes, is significantly lower in DCM samples than in NF ones (p<0.01). Super-enhancer (SE) analysis revealed that 481 and 119 genes are associated with NF- and DCM-specific SE respectively. Moreover, the differential E-P interactions were observed in the known heart failure gene loci, e.g., CTGF and NPPA-NPPB and these alternation interactions are correlated with the gene expression levels. Motif analysis identified known cardiac factors, such as MEF 2D and A and possible novel players, such as SOX transcription factors, namely SOX4 and SOX8, are enriched within enhancers and prompter regions identified in DCM samples. Their expression levels were confirmed with the whole-transcriptome analysis and protein assays.

Conclusions: We have established cistrome for major histone modifications and long-range chromatin interaction for enhancer and promoter in NF and DCM tissues. The differential histone modifications and E-P interactions were found in DCM and these differences were associated with the gene expression level of a subset of disease-associated genes in human heart failure.

[Analysis on probability of premature death and cause eliminated life expectancy of major non-communicable diseases in Chongqing Municipality, 2016]

Objective: To analyze the premature death probability and cause-eliminated life expectancy of cardiovascular disease, cancer, chronic respiratory disease and diabetes in Chongqing residents in 2016 so as to provide recommendation for non-communicable diseases (NCDs) prevention and control in Chongqing. Methods: Death cases of Chongqing Municipality between January 1(st) and December 31(st), 2016 were reported through death case registry system of national center for disease prevention and control. Death cases were sorted by international classification of disease (ICD-10). Mortality rate, standardized mortality rate, constituent ratio, premature death probability, life expectancy, and cause-eliminated life expectancy of four major NCDs were analyzed. Results: A total of 218 004 death cases were reported in Chongqing, 2016, and the mortality rate was 731.73/100 000. Of them, a total of 179 637 death cases of the four major NCDs including cardiovascular disease, cancer, chronic respiratory disease and diabetes were reported, accounting for 82.40% of all death cases. The mortality rate and standardized mortality rate of four major NCDs was 602.95/100 000 and 455.82/100 000, respectively. The premature death probability of four major NCDs was 15.96%, and males (25.39%) had a higher premature death probability than females (10.78%). The premature death probability of cardiovascular disease, cancer, chronic respiratory disease, and diabetes were 6.01%, 8.32%, 2.05%, and 0.43%, respectively. Life expectancy would increase by 6.02, 3.19, 1.89, and 0.19 years, after eliminating cardiovascular disease, cancer, chronic respiratory disease and diabetes respectively. Conclusion: The premature death probability of major NCDs was high in Chongqing, and males had a higher premature death probability than females did. Intervention and health management of the population should be conducted according to different gender-based risk factors to reduce the premature death probability.

Recent advances in hypertrophic cardiomyopathy

Several advances in molecular genetics and cardiac imaging of patients with hypertrophic cardiomyopathy (HCM) have been developed in recent years. The commercially available genetic testing is currently used (a) to identify affected relatives in families known to have HCM and (b) to differentiate HCM from metabolic storage disorders and other HCM phenocopies. Cardiovascular magnetic resonance has emerged as a useful tool to assess the magnitude and distribution of hypertrophy or mitral valve apparatus anatomy, which may have an impact on decision making regarding invasive management of HCM.

Abstract 255: Neutrophil-to-Eosinophil Ratio Predicts Mortality in Patients with Advanced Heart Failure

Background: Higher neutrophil count has been associated with poor prognosis in patients with heart failure. Also, eosinopenia has been recently described in some studies as a prognostic marker. The prognostic value of neutrophil-to-eosinophil ratio (NER) in advanced heart failure patients has not been explored.

Methods: We reviewed 491 consecutive patients with stage D heart failure who underwent transplant evaluation from 2007 to 2010. NER = absolute neutrophil count / absolute eosinophil count. Based on NER, patients were divided into tertiles. Survival (death or heart transplant) analysis was analayzed by Kaplan-Meier curves in different tertiles.

Results: Mean NER was 62.8 ± 111.3. Mortality/transplant rates increased with increasing NER tertiles (43.6%, 50.6%, and 54.9%). Kaplan-Meier survival analysis showed statistically significant prognostic importance with increasing NER tertiles. (log rank, p = 0.03, Figure.1). NER (HR, 1.24, 95% CI, 1.05, 1.46, p = 0.009) proved to be an independent predictor of mortality in a multivariate model including age, gender, diabetes, albumin, sodium, creatinine, etc.

Conclusion: Neutrophil-to-Eosinophil ratio may provide independent prediction of adverse outcomes in patients with advanced heart failure.

Abstract 271: Lack Of Prognostic Value Of High Ankle Brachial Pressure Index (ABI) In Patients With Advanced Heart Failure

Introduction: Ankle brachial pressure index (ABI) is a noninvasive test to diagnose peripheral arterial disease (PAD). Abnormally high ABI has been associated with increased LV mass and mortality in patients free of cardiovascular disease, while low ABI is often indicative of PAD that portends poor prognosis. But the prognostic significance of high ABI in advanced heart failure patients has not been studied.

Methods: We reviewed 342 consecutive patients with advanced heart failure who underwent transplant evaluation between 2007 and 2011. Patients with history of PAD or ABI < 0.9 on either side were excluded. ABI values on both sides were added to create total ABI. Based on this total ABI, patients were divided into tertiles. Survival (death or heart transplant) analysis was assessed by Kaplan-Meier curves in different tertiles.

Results: Mean total ABI was 2.29 ± 0.39. Mortality/transplant rates were 52.4%, 43.2% and 50.4% in increasing ABI tertiles. Kaplan-Meier survival analysis did not show any statistically significant prognostic importance (log rank, p = 0.39, Figure.1). Similar results were obtained when patients with ischemic (p = 0.094) and non-ischemic cardiomyopathy (p =0.899) were analyzed separately. ABI was not an independent predictor of mortality in Cox regression analysis (HR 0.95, 95% CI 0.66, 1.36).

Conclusion: Higher tertiles of ABI were not associated with poor prognosis in patients with stage D heart failure. This remained true for both ischemic and non-ischemic cardiomyopathy.

Abstract 51: Neutrophil to Lymphocyte Ratio Predicts Mortality in Stage D Heart Failure Patients

Background Neutrophil to lymphocyte ratio (NLR) has shown to be a predictor of prognosis in acute heart failure and other disorders like pancreatitis and hepatocellular carcinoma, but utility of NLR in chronic heart failure has not been evaluated before. Our hypothesis is that NLR is an independent predictor of prognosis in advanced (“stage D”) chronic heart failure.

Methods We reviewed 537 consecutive patients with stage D heart failure who underwent evaluation for advanced heart failure therapies from 2007 to 2010. Patients were divided into tertiles based on NLR. Predictors of NLR and mortality were determined. Survival was determined by chart review and confirmed by Social Security Death Index.

Results In our study cohort (mean age 53.6 ± 12.8 years, 73% male, mean LVEF 21.6 ± 14.2%), higher NLR was associated with lower albumin (OR, 0.23, 95% CI, 0.16-0.34) and higher blood urea nitrogen (OR, 1.03, 95% CI, 1.01, 1.04). Death rates increased with NLR by tertiles (7.3%, 31.6%, and 41.8%). NLR (HR, 1.02, 95% CI, 1.01, 1.05) proved to be an independent predictor of mortality in a multivariate model including albumin and blood urea nitrogen.

Conclusion In patients with advanced Stage D chronic heart failure, NLR is an independent predictor of mortality.

Figure 1: Survival Analysis showing increasing mortality with increasing NLR by tertiles.

Abstract 50: Elevated Serum Cobalamin associated Increased Mortality in Advanced Heart Failure

Introduction: Elevated serum cobalamin (B12) has been associated with liver dysfunction in decompensated heart failure. We hypothesize that elevated B12 is associated with worse outcomes in advanced heart failure.

Methods: We examined 115 consecutive patients with advanced heart failure undergoing evaluation for advanced therapies. Patients receiving B12 injections were excluded. Our lab considers B12 >900pg/mL as elevated. Linear regression was performed to determine significant predictors. Survival was assessed by Kaplan Meier curves.

Results: Mean and median serum B12: 843± 362pg/mL, 795 pg/mL (IQR 551-1046). Patients with elevated values were more likely to be have diabetes, dyslipidemia, COPD, CAD, and CKD. Less likely to be on spironolactone or be transplanted. Patients had higher total bilirubin and RDW; lower MVO2 and cardiac index. Hepatic, cholestatic, inflammatory and renal biomarkers were not found to be predictive of elevated B12, but MVO 2 (OR: 0.93, [95%CI 0.87,0.99]) was. At 2-yr, transplanted patients with increased B12 had higher mortality (logrank p=0.006).

Conclusions: Serum B12 is elevated in patients with advanced heart failure. Decreased MVO2 and markers of chronic inflammation are predictive of higher B12 levels. Elevated B12 is a significant predictor of mortality. Mechanistic studies of B12 in heart failure could provide key insights into the complexity of heart failure pathophysiology.

Figure 1: Survival Analysis of Elevated versus normal Serum B12 levels

Rolofylline (KW-3902): a new adenosine A1-receptor antagonist for acute congestive heart failure

Rolofylline (KW-3902 or MK-7418) is an adenosine A1-receptor antagonist that exerts its effect by blocking adenosine-mediated constriction of the afferent glomerular arteriole. By blocking A1 receptors, rolofylline increases the glomerular blood flow and filtration and inhibits sodium reabsorption in the proximal tubule, thereby enhancing natriuresis and diuresis. Early phase clinical research data provided the proof-of-concept of an incremental effect beyond standard diuretic therapy. A large Phase III program is currently ongoing for the intravenous formulation of rolofylline in the treatment of acute heart failure.

A critical review of anti-adrenergic therapy in patients with heart failure and diabetes mellitus

Anti-adrenergic therapy has been widely accepted as an important therapeutic intervention in patients with chronic heart failure. However, there has been continuing controversy regarding the risks and clinical significance of metabolic effects of different anti-adrenergic drugs. This review summarizes what has been learned from clinical trial evidence regarding the benefits of anti-adrenergic drugs in diabetic patients with chronic heart failure.

10 GHz pulses generated across a ~100 nm tuning range using a gain-shifted mode-locked SOA ring laser

Widely-tunable picosecond pulses have been generated from a harmonically mode-locked semiconductor optical amplifier (SOA) ring laser with a center wavelength spanning from 1491 to 1588 nm. An intra-cavity birefringence loop mirror filter is used to define a 1.6 nm comb that governs the wavelength spacing of the tunable output pulses. The filter also serves to control the spectral gain profile of the laser cavity and thus extends the tuning range. By exploiting the spectral shift of the SOA gain with different amount of optical feedback, the output can be obtained over a wid wavelength range. Applying mode-locking together with the dispersion tuning approach, 10 GHz picosecond pulses have been successfully generated over a tuning range of 97 nm.

Repetition rate multiplication of multi-wavelength pulses by spectral elimination with a birefringence loop mirror filter

We demonstrate simultaneous repetition rate multiplication of laser pulses at multiple wavelengths using the spectral elimination approach. The phase coherence between the pulses is preserved while the aggregate bandwidth can be significantly enhanced. The repetition rates of pulses from both a mode-locked fiber ring laser and a pair of gain-switched DFB laser diodes have been multiplied to over 18 GHz per wavelength using the same setup. The key element is an all-fiber, polarization independent birefringence loop mirror comb filter. The broad transmission peaks of the filter also allow a large tolerance in the drift of the input wavelengths and repetition rates. A detuning range of 1.2 GHz is observed, corresponding to 13% of the input frequency.

Self-starting picosecond optical pulse source using stimulated Brillouin scattering in an optical fiber

We demonstrate a regeneratively mode-locked optical pulse source at about 10 GHz using an optoelectronic oscillator constructed with an electro-absorption modulator integrated distributed feedback laser diode. The 10 GHz RF component is derived from the interaction between the pump wave and the backscattered, frequency-downshifted Stokes wave resulted from stimulated Brillouin scattering in an optical fiber. The component serves as a modulation source for the 1556 nm laser diode without the need for any electrical or optical RF filter to perform the frequency extraction. Dispersion-compensated fiber, dispersion-shifted fiber, and standard single-mode fiber have been used respectively to generate optical pulses at variable repetition rates.

Effects of Epoetin alfa on hemostasis in chronic renal failure

Epoetin alfa is the cornerstone of anemia therapy in patients with end-stage renal disease. In addition to stimulating erythropoiesis, Epoetin alfa has been demonstrated to affect hemostasis. Such effects may be important because patients with chronic renal failure have a bleeding diathesis that is multifactorial in origin. Therefore, a computer literature search on the relationship between Epoetin alfa therapy for anemia in patients with end-stage renal disease and platelets, coagulation, coagulation inhibitors, and fibrinolysis was performed. All articles and abstracts reporting original data in the English language on Epoetin alfa and its effect on hemostasis were reviewed. The literature suggests that the effects of Epoetin alfa on the coagulation cascade are of minimal clinical importance. However, Epoetin alfa transiently increases the number of circulating platelets and improves platelet function, and these effects are associated with a return of the bleeding time towards normal.

Pathophysiological role of T lymphocytes in renal ischemia-reperfusion injury in mice

Mononuclear cell infiltrates are found in human renal ischemia-reperfusion injury (IRI), and peritubular T lymphocytes have been identified in experimental IRI. However, the role of T cells in the pathogenesis of renal IRI is unknown. We hypothesized that T cells are one of the important mediators of renal IRI. To test this hypothesis, we used an established mouse model of renal IRI, and evaluated mice with genetically engineered deficiency of both CD4+ and CD8+ T cells. At 48 h postischemia, CD4/CD8-knockout (KO) mice had marked improvement in renal function compared with control C57BL/6 mice (serum creatinine: 0.7 +/- 0.4 vs. 2.5 +/- 0.3 mg/dl, respectively; P < 0.05). Neutrophil infiltration into postischemic kidney was reduced in CD4/CD8 KO mice, compared with control mice, at both 24 h [polymorphonuclear neutrophils (PMNs)/10 high power fields: 714 +/- 354 vs. 3,514 +/- 660, respectively; P < 0.05] and 48 h (88 +/- 32 vs. 1,979 +/- 209, respectively; P < 0.05). Tubular necrosis score in CD4/CD8 KO mice, compared with control mice, was significantly less at 48 h (0.4 +/- 0.1 vs. 2.4 +/- 0.2, respectively; P < 0.05). Because adhesion between T cells and renal tubular epithelial cells (RTECs) may underlie the pathophysiological role of T cells in renal IRI, we also measured T cell adhesion to primary murine RTECs in vitro. Exposure of RTECs to 2 h of hypoxia followed by 1 h of reoxygenation increased T cell adhesion more than twofold. Phorbol ester treatment, which activates integrins, increased T cell adhesion threefold. These data suggest that T lymphocytes can mediate experimental renal IRI. Moreover, adhesion of infiltrating T cells to renal tubular cells may provide a potential mechanism underlying postischemic tubular dysfunction.

Glomerular extracellular matrix accumulation in experimental anti-GBM Ab glomerulonephritis

Thickening of the glomerular basement membrane (GBM) results from excessive accumulation of extracellular matrix (ECM) proteins following glomerular injury. We studied the temporal relationship between the expression of growth factors, ECM accumulation, ECM degrading proteinases, and their inhibitors in a rat model of anti-GBM antibody (Ab) glomerulonephritis (GN) by the RNase protection assay and immunohistochemistry. There were two- or fourfold increases in the expression of transforming growth factor-beta(1) (TGF-beta(1)) and platelet-derived growth factor (PDGF) A and B chain mRNAs 4 days after anti-GBM Ab administration. These changes were temporally associated with increased accumulation of alpha1(III) and alpha2(IV) collagens, fibronectin, and heparan sulfate proteoglycan along the GBM. The increase in matrix accumulation was associated with little or no increases in the proteinases, urokinase plasminogen activator (u-PA) and transin, respectively. There was a 1.6x increase in the u-PA/28s mRNA ratio on day 4 in rats with anti-GBM Ab GN, but this was not associated with an increase in u-PA biologic activity. By comparison, the mRNAs of the proteinase inhibitors, plasminogen activator inhibitor-1 (PAI-1) and tissue inhibitor of metalloproteinase (TIMP) were 5x greater than that of control rats on day 4. PAI-1 mRNA correlate with increased biologic activity. These data demonstrate a temporal association between TGF-beta(1) and PDGF expression and matrix accumulation within the GBM in anti-GBM Ab GN. In addition, it suggest that this matrix accumulation results from an imbalance between matrix synthesis and degradation.

Retinoic acid induces down-regulation of Wnt-3a, apoptosis and diversion of tail bud cells to a neural fate in the mouse embryo

The tail bud comprises the caudal extremity of the vertebrate embryo, containing a pool of pluripotent mesenchymal stem cells that gives rise to almost all the tissues of the sacro-caudal region. Treatment of pregnant mice with 100 mg/kg all-trans retinoic acid at 9.5 days post coitum induces severe truncation of the body axis, providing a model system for studying the mechanisms underlying development of caudal agenesis. In the present study, we find that retinoic acid treatment causes extensive apoptosis of tail bud cells 24 h after treatment. Once the apoptotic cells have been removed, the remaining mesenchymal cells differentiate into an extensive network of ectopic tubules, radially arranged around the notochord. These tubules express Pax-3 and Pax-6 in a regionally-restricted pattern that closely resembles expression in the definitive neural tube. Neurofilament-positive neurons subsequently grow out from the ectopic tubules. Thus, the tail bud cells remaining after retinoic acid-induced apoptosis appear to adopt a neural fate. Wnt-3a, a gene that has been shown to be essential for tail bud formation, is specifically down-regulated in the tail bud of retinoic acid-treated embryos, as early as 2 h after retinoic acid treatment and Wnt-3a transcripts become undetectable by 10 h. In contrast, Wnt-5a and RAR-gamma are still detectable in the tail bud at that time. Extensive cell death also occurs in the tail bud of embryos homozygous for the vestigial tail mutation, in which there is a marked reduction in Wnt-3a expression. These embryos go on to develop multiple neural tubes in their truncated caudal region. These results suggest that retinoic acid induces down-regulation of Wnt-3a which may play an important role in the pathogenesis of axial truncation, involving induction of widespread apoptosis, followed by an alteration of tail bud cell fate to form multiple ectopic neural tubes.

Crescentic glomerulonephritis in CD4- and CD8-deficient mice. Requirement for CD4 but not CD8 cells

The contribution of CD4 and CD8 cells to crescentic glomerulonephritis (GN) was studied in mice genetically deficient in CD4, CD8, and with combined CD4 and CD8 (CD4/CD8) deficiency. Wild-type (C57BL/6) mice developed GN with mild proliferative changes 7 days after an intravenous dose of sheep anti-mouse glomerular basement membrane globulin. Crescents were observed in 12.5 +/- 6.1% of glomeruli on day 14. On day 21, 51.5 +/- 7.3% of glomeruli were affected by crescents, and mice had marked azotemia and proteinuria. CD4 and combined CD4/CD8-deficient mice developed minimal evidence of GN. On day 21, their glomeruli showed only mild proliferative changes and crescents, azotemia, and proteinuria were absent. In contrast, CD8-deficient mice developed severe crescentic GN with three of five mice dying on day 20 with ascites and edema. The two mice surviving to day 21 had severe azotemia. Crescent development was accelerated (day 14, 51.6 +/- 2.4% of glomeruli; day 20 or 21, 62.0 +/- 4.0% of glomeruli). These studies demonstrate that CD4 cells are crucial for the development of crescentic GN in mice and that genetic absence of CD8 cells accelerates disease. They support the hypothesis that crescent formation is a manifestation of CD4-dependent (and CD8-independent) delayed type hypersensitivity in the glomerulus.

Chemokine expression in experimental tubulointerstitial nephritis

Chemokines may be important in the pathogenesis of leukocyte infiltration in tubulointerstitial nephritis associated with glomerular disease. We studied the renal cortical expression of the C-C (macrophage inflammatory protein-1alpha (MIP-1alpha)), monocyte chemotactic protein-1 (MCP-1), and RANTES) and C-X-C (interferon-inducible protein-10 (IP-10), MIP-2, and cytokine-induced neutrophil chemoattractant (CINC)) chemokines 4, 6, 8, 10, 14, and 21 days after the induction of puromycin aminonucleoside (PAN) nephrosis. There was a 7- to 10-fold increase in the steady state mRNA expression of IP-10 and MCP-1 in the renal cortex of rats 6 to 8 days after the administration of PAN that declines thereafter reaching control values by day 21. The site of IP-10 and MCP-1 mRNA production was localized to intrinsic tubulointerstitial cells and not to infiltrating monocytes or macrophages. By comparison, there was a low basal expression of RANTES mRNA in the renal cortex of nephrotic rats that did not differ from those of control rats. In contrast, CINC, MIP-2, and MIP-1alpha mRNAs were not detected. Translation of MCP-1 mRNA into protein was confirmed with an ELISA. These changes in chemokine gene expression were associated with a tubulointerstitial T lymphocyte and macrophage infiltration beginning on day 6 that peaked on day 10. Administration of a neutralizing Ab to rat MCP-1 (n = 5) beginning on day 4 resulted in a 45% decline in tubulointerstitial macrophage infiltration from 8.4 +/- 1.3% to 4.6 +/- 0.4% (p &lt; 0.001) on day 6. These data provide evidence that MCP-1, and possibly IP-10, are important in the pathogenesis of monocyte/macrophage infiltration in the tubulointerstitial nephritis associated with PAN nephrosis.

Chemokine expression in experimental tubulointerstitial nephritis

Chemokines may be important in the pathogenesis of leukocyte infiltration in tubulointerstitial nephritis associated with glomerular disease. We studied the renal cortical expression of the C-C (macrophage inflammatory protein-1alpha (MIP-1alpha)), monocyte chemotactic protein-1 (MCP-1), and RANTES) and C-X-C (interferon-inducible protein-10 (IP-10), MIP-2, and cytokine-induced neutrophil chemoattractant (CINC)) chemokines 4, 6, 8, 10, 14, and 21 days after the induction of puromycin aminonucleoside (PAN) nephrosis. There was a 7- to 10-fold increase in the steady state mRNA expression of IP-10 and MCP-1 in the renal cortex of rats 6 to 8 days after the administration of PAN that declines thereafter reaching control values by day 21. The site of IP-10 and MCP-1 mRNA production was localized to intrinsic tubulointerstitial cells and not to infiltrating monocytes or macrophages. By comparison, there was a low basal expression of RANTES mRNA in the renal cortex of nephrotic rats that did not differ from those of control rats. In contrast, CINC, MIP-2, and MIP-1alpha mRNAs were not detected. Translation of MCP-1 mRNA into protein was confirmed with an ELISA. These changes in chemokine gene expression were associated with a tubulointerstitial T lymphocyte and macrophage infiltration beginning on day 6 that peaked on day 10. Administration of a neutralizing Ab to rat MCP-1 (n = 5) beginning on day 4 resulted in a 45% decline in tubulointerstitial macrophage infiltration from 8.4 +/- 1.3% to 4.6 +/- 0.4% (p < 0.001) on day 6. These data provide evidence that MCP-1, and possibly IP-10, are important in the pathogenesis of monocyte/macrophage infiltration in the tubulointerstitial nephritis associated with PAN nephrosis.

Myofibroblast and alpha 1 (III) collagen expression in experimental tubulointerstitial nephritis

Despite the importance of tubulointerstitial fibrosis as a predictor of renal function in patients with primary glomerular disease, the identity of the cell(s) that is the source of interstitial collagen production remains unknown. The present study was performed to identify the site of alpha 1(III) production during the development of tubulointerstitial fibrosis. We studied a model of experimental tubulointerstitial nephritis associated with puromycin aminonucleoside (PAN) nephrosis. There was a twofold increase in renal cortical alpha 1 (III) mRNA expression coincident with the onset of tubulointerstitial myofibroblasts infiltration in rats with PAN nephrosis beginning on day 6, which increased to a fivefold difference by day 10. There were 60.8 +/- 40.3 myofibroblast/mm2 within the renal tubulointerstitium of rats with PAN nephrosis on day 6 that peaked at 240.2 +/- 11.1 myofibroblast/mm2 on day 14, which then declined to 43.7 +/- 9.8 myofibroblast/mm2 by day 21. By combining in situ hybridization with immunohistochemistry, alpha 1(III) mRNA expression was colocalized to cells that labeled for alpha-smooth muscle actin identifying them as myofibroblasts. Interestingly, the major site of alpha 1(III) mRNA expression shifted to tubuloepithelial cells with the waning of myofibroblast infiltration on day 21. To determine if PDGF-BB induced myofibroblasts to synthesize alpha 1(III) mRNA, we examined kidneys from rats that had been treated with PDGF-BB (5 mg/kg/day). alpha 1(III) mRNA expression also localized to cells that labeled for alpha-smooth muscle actin. These data demonstrate the cellular source of alpha 1(III) production within the renal tubulointerstitium following injury, and suggest that PDGF-BB may be mediating this production.

Leukemia inhibitory factor ameliorates experimental anti-GBM Ab glomerulonephritis

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that has been identified in acute and chronic inflammatory conditions such as rheumatoid arthritis, sepsis, and renal allograft rejection. We investigated the glomerular expression of LIF at 30 minutes, and 3, 6, 9, 15 and 24 hours after administration of anti-GBM Ab (N = 3) by the RNase protection assay. Control rats received rabbit sera and were sacrificed at 30 minutes, and 6 and 24 hours. LIF mRNA relative to GAPDH mRNA was detected at low levels within the glomeruli of occasional control rats. However with the induction of anti-GBM Ab GN, there was a marked increase in LIF steady-state mRNA beginning at three hours which persisted through 24 hour. LIF mRNA was also detected in cultured mesangial cells stimulated with IL-1 beta, identifying this cell type as a potential glomerular source for this cytokine. To investigate the in vivo effect of LIF, Lewis rats were continuously infused with recombinant (r) human (h) LIF (approximately 0.5 ng/hr) or saline vehicle i.p. with ALZA osmotic pumps beginning at t = -24 hours (N = 8). All rats were injected with anti-GBM Ab intravenously at t = 0 (N = 16). LIF infusion decreased 24-hour urinary protein excretion by 85% (17 +/- 15 vs. 114 +/- 37 mg/day, P = 0.0001) and was associated with a 60% decrease in glomerular macrophage infiltration (0.8 +/- 0.2 vs. 2.0 +/- 0.6 ED-1 cells/glom, P = 0.0001). The administration of rhLIF did not affect the binding of the anti-GBM Ab to glomeruli. The beneficial effects of LIF were associated with a decrease in glomerular MCP-1 (56%), IL-1 (41%) and TNF (17%) steady state mRNA expression. The latter was associated with a 29% decrease in TNF-alpha protein expression within the glomerular lysate of nephritic rats administered LIF when compared with control rats. These data demonstrate a potential role for LIF in the therapy of anti-GBM Ab GN.

Monocyte chemoattractant protein 1 mediates glomerular macrophage infiltration in anti-GBM Ab GN

Monocyte chemoattractant protein 1 (MCP-1) is a C-C chemokine with potent monocyte chemotactic and activating properties that may contribute to glomerular macrophage infiltration in anti-GBM Ab GN. We have previously reported increased glomerular steady state expression of MCP-1 mRNA relative to GAPDH mRNA in the heterologous phase of experimental anti-GBM Ab GN. In this report, we expand upon these data by demonstrating that the increase in MCP-1 mRNA correlated with MCP-1 protein expression at 24 hours that was determined with an ELISA (2069 +/- 147 pg/mg glom lysate). This increase in MCP-1 expression was associated with glomerular monocyte/ macrophage infiltration which peaked at 24 hours (8.2 +/- 1.0 ED-1 cells/glom). The site of MCP-1 mRNA production was localized by combining immunohistochemistry with in situ hybridization. The majority of cells which expressed MCP-1 mRNA at three hours were intrinsic glomerular cells, while 55% of the cells that expressed MCP-1 mRNA at 15 hours were monocytes/macrophages. To determine if MCP-1 affected glomerular macrophage infiltration, rats with alpha-GBM Ab GN were administered a polyclonal neutralizing Ab to rat MCP-1. This resulted in a 38% decline in glomerular macrophage infiltration (3.3 +/- 0.3 vs. 1.8 +/- 0.2 ED-1 cells/glom, P = 0.0001) that was associated with a 45% reduction in urinary protein excretion (260 +/- 53 vs. 162 +/- 46 mg/d, P = 0.0001). These data demonstrate an important role for MCP-1 in the pathogenesis of glomerular macrophage infiltration in anti-GBM Ab GN.

Platelet-derived growth factor-BB induces renal tubulointerstitial myofibroblast formation and tubulointerstitial fibrosis

Tubulointerstitial fibrosis correlates closely with renal function, although the mechanism regulating tubulointerstitial fibrogenesis remains poorly understood. Since platelet-derived growth factor (PDGF) is a growth factor for fibroblasts, we examined the effect of daily (for 7 days) PDGF-AA or PDGF-BB administration on renal tubulointerstitial architecture in rats. PDGF-AA administration at a dose of 5 mg/kg did not affect the renal tubulointerstitium. By comparison, PDGF-BB induced dose-dependent renal tubulointerstitial cell proliferation and fibrosis. At 5 mg/kg, PDGF-BB increased BrdU labeling in tubulointerstitial fibroblasts at 24 hours (19-fold), which peaked at 72 hours (23-fold) with bromodeoxyuridine uptake returning to control values by 7 days. Tubulointerstitial proliferation was associated with the differentiation of these cells into myofibroblasts as evidenced by alpha-smooth muscle actin expression beginning on day 3. The expression of alpha-smooth muscle actin peaked on day 5 and had markedly declined by day 21. In addition, apoptotic cells were identified within the tubulointerstitium on day 3 and progressively increased through day 7, suggesting that the disappearance of myofibroblasts may have occurred through apoptosis. These changes were accompanied by increased expression of alpha 1 (III) collagen mRNA and interstitial accumulation of type III collagen within the renal cortex. By morphometric analysis, an approximately twofold increase in collagen III immunolabeling within the interstitial compartment was evident at 24 hours and peaked on days 5 to 7 (approximately fourfold). These data suggest that PDGF-BB may be an important mediator of tubulointerstitial hyperplasia and fibrosis.

Intratracheal injection of endotoxin and cytokines. IX. Contribution of CD11a/ICAM-1 to neutrophil emigration

Intratracheal injection of endotoxin [lipopolysaccharide (LPS)] in rats causes acute inflammation characterized by the emigration of neutrophils (PMNs) into the bronchoalveolar airspace. Antibody to PMN adhesion molecule CD11a inhibited LPS-initiated PMN accumulation in bronchoalveolar lavage (BAL) fluid by 32% (P < 0.001). Antibody to the endothelial CD11a counterreceptor intercellular adhesion molecule-1 (ICAM-1) inhibited LPS-initiated PMN accumulation in BAL fluid by 66% (P < 0.0001). Combined antibody blockade of ICAM-1 and the C-X-C chemokine cytokine-induced neutrophil chemoattractant (CINC) inhibited LPS-initiated PMN emigration by 80%, significantly more than antibody against either ICAM-1 or CINC alone. To study the relative contribution of alveolar macrophages and PMNs to intra-alveolar tumor necrosis factor (TNF), the LPS-induced TNF in BAL fluid was measured after depletion of circulating PMNs with a cytolytic antibody to CD18. Although the anti-CD18 antibody completely abrogated LPS-initiated PMN emigration into BAL fluid, TNF levels in BAL fluid were unaffected, suggesting that alveolar macrophages are the predominant cellular source of LPS-induced TNF production. In conclusion, 1) CD11a, ICAM-1, and CINC play major roles in the LPS-initiated emigration of PMNs into the bronchoalveolar space, and 2) the TNF that drives ICAM-1 and CINC expression is derived largely from alveolar macrophages rather than PMNs.

Chemokine gene expression in anti-glomerular basement membrane antibody glomerulonephritis

Chemokines may be important in the pathogenesis of glomerular leukocyte infiltration in antiglomerular basement membrane (GBM) antibody (Ab) glomerulonephritis (GN). We studied the expression of the C-C chemokines [macrophage inflammatory protein (MIP)-1 alpha, monocyte chemotactic protein (MCP)-1, and RANTES] and C-X-C chemokines [platelet factor 4 (PF4), interferon-inducible protein of 10 kDa (IP-10), MIP-2, and cytokine-induced neutrophil chemoattractant (CINC)] at 30 min, 3, 6, 9, 15, and 24 h after induction of heterologous-phase anti-GBM Ab GN in Lewis rats. There was a rapid induction of CINC, MIP-2, MCP-1, and MIP-1 alpha mRNAs in the glomeruli of nephritic rats 30 min after administration of the anti-GBM Ab, whereas increases in PF4 and IP-10 mRNAs were not seen until 3 h. The mRNA expression of PF4, MIP-1 alpha, MIP-2, and IP-10 peaked at 3 h, whereas CINC and MCP-1 peaked at 6 and 15 h, respectively. By comparison, the expression of RANTES mRNA in rats with anti-GBM Ab GN did not differ from those of control rats. These changes in chemokine gene expression were associated with glomerular polymorphonuclear leukocytes (PMN) and monocyte/macrophage infiltration which peaked at 3 h (20.8 +/- 11.1 PMN/glomerulus) and 24 h (8.2 +/- 1.0 ED-1 cells/glomerulus), respectively. The administration of dexamethasone suppressed glomerular chemokine mRNA expression (60-98%) at both 3 and 15 h, which was associated with a 50-100% reduction in glomerular PMN and monocyte/macrophage infiltration, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein C inhibitor is expressed in tubular cells of human kidney

Protein C inhibitor (PCI) is a serpin that inhibits a number of proteases. PCI is found in urine and binds to kidney epithelial cells. To determine if kidney is a source of PCI, cDNA was produced from human kidney total RNA. Sequencing and restriction mapping showed identity between kidney and liver PCI cDNA sequences. Similar cDNAs were obtained from rhesus monkey kidney and liver RNAs. Conditioned medium from the rhesus monkey kidney cell line CCL7.1 was analyzed on immunoblots, showing a 57,000-D protein band that comigrated with human plasma PCI. Immunohistochemical staining and in situ hybridization of human kidney tissue sections showed that kidney PCI antigen and RNA were confined to tubular cells. The findings are consistent with the idea that PCI is synthesized and localized in kidney tissue where it may provide protease inhibitory activity and suggest that complexes of PCI with urokinase found in human urine may be produced locally in the kidney.

Cytokine expression, upregulation of intercellular adhesion molecule-1, and leukocyte infiltration in experimental tubulointerstitial nephritis

BACKGROUND

Cytokines are intercellular polypeptide messengers that mediate immune and inflammatory responses. The temporal profile of interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor alpha (TNF-alpha), and monocyte chemotactic protein 1 (MCP-1) expression was examined in anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN).

EXPERIMENTAL DESIGN

TIN was induced by immunization of Brown Norway rats with bovine cortical TBM, whereas control rats received ovalbumin. Whole kidney RNA was assessed with the RNase protection assay 3, 7, 8, 9, 10, 12, and 14 days after immunization. Cytokine mRNA expression was correlated with TNF-alpha bioactivity, renal intercellular adhesion molecule-1 expression, and CD18-positive leukocyte infiltration by immunohistochemistry.

RESULTS

Increased IL-1 beta, TNF-alpha, and MCP-1 mRNA relative to glyceraldehyde-3-phosphate dehydrogenase appeared on day 7 when TIN involved 10 to 40% of the cortex, and peaked rapidly on day 8 when there was 60 to 80% cortical involvement (at which time 75 to 80% of the infiltrating cells were neutrophils). The increase in TNF-alpha mRNA correlated with increased bioactivity. The influx of mononuclear cells on day 8 was preceded by the expression of MCP-1 mRNA. The infiltrating leukocytes expressed the leukocyte beta 2-integrin (CD18) and were found in areas with increased intercellular adhesion molecule-1 expression. The mRNAs for IL-1 beta, TNF-alpha, and MCP-1 were undetectable by day 10 (at which time 95% of the infiltrating cells were mononuclear). An increase in IL-1 receptor antagonist mRNA paralleled those of IL-1 beta. The expression of IL-6 mRNA was similar to that for IL-1, except that it disappeared by day 9.

CONCLUSIONS

There is a temporal association in the expression of IL-1 beta, TNF alpha, MCP-1, and IL-6 with the upregulation of intercellular adhesion molecule-1 and leukocyte infiltration within the tubulointerstitium in anti-TBM antibody-associated TIN. The narrow window of time through which these cytokines are expressed and the coincidence of their peak expression on day 8 suggest complex cytokine interactions in the pathogenesis of anti-TBM antibody TIN.

Extracellular matrix accumulation in immune-mediated tubulointerstitial injury

The accumulation of excessive extracellular matrix (ECM) following tubular injury likely represents an imbalance between ECM production and degradation. We assessed the temporal relationship between the accumulation of ECM, cell adhesion molecules, matrix degrading proteinases, and their inhibitors in a rat model of anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN) by the RNase protection assay and immunohistochemistry. There was an increase in the steady state expression of fibronectin (FN) and alpha 2(IV) collagen mRNAs beginning on day 7 with the onset of neutrophil infiltration. An increase in alpha 1(III) collagen and alpha 1-integrin did not occur until days 9 and 10, respectively, at which time mononuclear leukocytes were the predominant infiltrating cell. Increased levels of FN, alpha 1(III), alpha 2(IV) and alpha 1-integrin mRNAs occurred through day 14. By immunohistochemistry, increased accumulation of collagen IV, heparan sulfate proteoglycan, and laminin were detected along the thicken TBM; collagens I and III were immunolocalized within the tubulo-interstitium, while FN was present in both the TBM and interstitium in rats with TIN on day 14. The increase in matrix accumulation was associated with little or no increase in proteinases. u-PA transcripts fell beginning on day 8, with recovery to control values by day 12. Transin mRNA was found at low levels only on days 8 and 9, and the protein could not be detected by Western blotting. In contrast, these changes were associated with an increase in proteinase inhibitors, so that TIMP and PAI-1 mRNAs increased beginning on day 7 and persisted through day 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-1 receptor antagonist ameliorates experimental anti-glomerular basement membrane antibody-associated glomerulonephritis

The contribution of IL-1 to leukocyte infiltration in anti-glomerular basement membrane (GBM) antibody (Ab) glomerulonephritis (GN) was examined by the administration of a specific IL-1 receptor antagonist (IL-1ra). Lewis rats received anti-GBM Ab or normal rabbit serum and were treated with either 0.9% saline or 6 mg IL-1ra over a 24-h time period. Plasma IL-1ra concentration was 2,659 +/- 51 ng/ml 4 h after anti-GBM Ab and IL-1ra administration. PMN and monocyte/macrophage infiltration declined 39% (9.8 +/- 1.9 to 6.0 +/- 1.5 PMN/glomerulus, P < 0.001) and 29% (4.9 +/- 0.8 to 3.5 +/- 0.8 ED-1 cells/glomerulus, P = 0.002) with IL-1ra treatment at 4 h, respectively. Similarly, the number of glomerular cells staining for lymphocyte function-associated molecule-1 beta (CD18) declined 39% from 16.7 +/- 1.9 to 10.7 +/- 1.6 cells/glomerulus at 4 h (P = 0.0001). This was associated with a decrease in glomerular intracellular adhesion molecule-1 expression. The mean glomerular intracellular adhesion molecule-1 score in anti-GBM Ab GN rats treated with IL-1ra was less than that of rats administered anti-GBM Ab and 0.9% saline at 4 (2.0 +/- 0.2 vs 2.5 +/- 0.2, P < 0.05) and 24 (2.5 +/- 0.1 vs 3.1 +/- 0.2, P = 0.0001) h. These immunopathologic changes correlated with a 50% reduction in proteinuria from 147 +/- 34 to 75 +/- 25 mg/d (P < 0.002). Treatment with IL-1ra did not affect the steady state mRNA expression of either IL-1 beta or TNF alpha. An increase in the IL-1ra dose to 30 mg given within the initial 4 h provided no additional benefit. The decline in PMN and monocyte/macrophage infiltration of the glomerulus at 4 h was similar to that found in the initial study. Furthermore, the protective benefit of IL-1ra was abrogated by doubling the dose of the anti-GBM Ab GN, despite administering high dose IL-1ra (30 mg). In these studies, detectable IL-1ra was found in the serum of untreated anti-GBM Ab GN controls. These data suggest a positive yet limited role for IL-1ra in the therapeutic intervention of anti-GBM Ab GN.

Cloning two isoforms of rat cyclooxygenase: differential regulation of their expression

Two isoforms of cyclooxygenase (COX) have been identified in eukaryotic cells: COX-1 encoded by a 2.8-kb mRNA, and a mitogen-inducible COX-2 encoded by a 4-kb mRNA. We have cloned the COX-1 and COX-2 cDNAs from the cDNA library constructed from lipopolysaccharide (LPS)-stimulated rat peritoneal macrophages. The deduced amino acid sequence showed that COX-1 contained 602 amino acids, whereas COX-2 contained 604 amino acids. There is 95% conservation of the nucleotide sequence in the open reading frame of COX-1 between the rat and the mouse, while the homology of the 3' untranslated region is 68% except for a 150 bp segment adjacent to the stop codon which is nonhomologous with the mouse. Transfection of both COX cDNAs into Cos-7 cells resulted in increased COX activity. In rat vascular smooth muscle cells, interleukin-1 beta selectively increased the expression of COX-2, but not that of COX-1, as assessed by enzyme activity, immunoprecipitation of COX proteins, and mRNA analysis. Only the brain among tissues tested exhibits basal expression of COX-2 as the major form of the enzyme. However, COX-2 mRNA was expressed in vivo in the lung and kidney, but not in the heart, after systemic administration of LPS, suggesting that COX-2 but not COX-1 plays a major role in producing COX-derived products of arachidonic acid during endotoxic shock. Thus, the two COX isoforms were differentially expressed, and COX-2 was selectively induced in response to inflammatory stimuli in rats.

Cloning a novel form of rat PDGF A-chain with a unique 5'-UT: regulation during development and in glomerulonephritis

An unique form of rat platelet-derived growth factor A-chain (PDGF A-chain), with a novel 5' UT region, was cloned from a rat macrophage cDNA library and expressed. In the 5' UT, the homology of the 79 bp sequence adjacent to the ATG codon between rat and human was 92%; however, the homology of the remainder in the 5' UT was less than 30%. RNase mapping indicated this form was differentially expressed during development and immune glomerular injury, and that it probably arose from alternative splicing. We propose that the variant mRNAs reflect different levels of the control of PDGF A-chain expression.

Dysfunction of glomerular fibrinolysis in experimental antiglomerular basement membrane antibody glomerulonephritis

Glomerular plasminogen activator inhibitor-1 (PAI-1) steady-state mRNA and bioactivity were increased after the induction of an augmented form of antiglomerular basement membrane (GBM) antibody glomerulonephritis. PAI-1 mRNA expression was noted at 6 h, peaking at 1 day, and although falling thereafter, remained higher than that of the control group through Day 17. PAI-1 mRNA expression correlated with glomerular PAI-1 bioactivity as determined by a functional tissue type plasminogen activator (t-PA) binding assay. Glomerular PAI-1 bioactivity, not detected in controls, increased to 1.4 +/- 0.3 ng/mg of glomerular lysate at 6 h and then decreased to 0.7 +/- 0.1 ng/mg of glomerular lysate by Day 6. The mRNA of the plasminogen activators (urokinase plasminogen activator), t-PA) either remained unchanged or declined through Day 1, with a slight increase in t-PA mRNA at Day 6. Interleukin-1 beta mRNA expression was maximal at 6 h, declining by Day 3. Transforming growth factor beta 1 (TGF-beta 1) mRNA began to increase at Day 1, was maximal at Day 6, and fell only slightly by Day 17. Epidermal growth factor mRNA decreased. The increase in PAI-1 mRNA and bioactivity, possibly induced early by the interleukin-1 beta response and perhaps later by the TGF-beta 1 response, was associated with striking glomerular capillary lumen fibrin accumulations on Day 1, which decreased and appeared to recanalize as the PAI-1 mRNA and bioactivity fell. The glomerular lesion continued to have some fibrin deposits even on Day 17 and, in addition, had changes of thickened GBM, suggestive of the early stages of diffuse glomerulosclerosis. The latter had a temporal relationship with the persisting increase in TGF-beta 1 and PAI-1 mRNA levels. These observations suggest the possibility that inhibition of enzymes capable of remodeling excessive extracellular matrix production may have contributed to the thickened GBM.

Molecular cloning of rat cytokine synthesis inhibitory factor (IL-10) cDNA and expression in spleen and macrophages

Rat cytokine synthesis inhibitory factor (IL-10) was cloned. Like mouse and human IL-10 (mIL-10, hIL-10), rat IL-10 exhibits strong DNA and amino acid sequence homology to the open reading frame in the Epstein-Barr virus, BCRFI. The supernatant of COS-7 transfectants with rat IL-10 was found to inhibit the production of IFN-gamma by murine Th1 cells. A probe from the rat IL-10 was used in an RNase protection assay to demonstrate that IL-10 was expressed in LPS-stimulated rat spleen and FACS-purified OX-42-reactive peritoneal macrophages. The production of IL-10 by macrophages, as shown in the current study, suggests that IL-10 may have an autocrine function in inflammation.

Hyponatremia in hospitalized patients with the acquired immunodeficiency syndrome (AIDS) and the AIDS-related complex

STUDY OBJECTIVE

To determine the frequency, etiology, and clinical association of hyponatremia in patients with the acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC).

PATIENTS AND METHODS

A prospective analysis of 167 patients with AIDS and 45 patients with ARC admitted on 259 occasions to a large metropolitan teaching hospital during a 3-month period.

RESULTS

Eighty-three patients (39%) with hyponatremia (serum sodium concentration less than 135 mmol/L) were observed during 99 hospitalizations, for a frequency of 38%. The mean (+/- standard error) of the lowest serum sodium concentration was 128 +/- 1 mmol/L in the hyponatremic patients and 138 +/- 1 mmol/L in the normonatremic patients. Hyponatremia was present on admission during 57 hospitalizations and was associated with gastrointestinal losses and hypovolemia in 43%. When hyponatremia developed during hospitalization, 68% of the patients were clinically euvolemic and had a syndrome consistent with inappropriate secretion of antidiuretic hormone (SIADH). Patients with hyponatremia were hospitalized longer than those with normal serum sodium concentrations (17 +/- 1 versus 9 +/- 1 days, p < 0.001). In addition, the mortality rate in the hyponatremic group was higher than that in the normonatremic group (36.5% versus 19.7%, p < 0.01).

CONCLUSION

Hyponatremia is a common electrolyte disorder in patients hospitalized with AIDS or ARC and is frequently associated with gastrointestinal losses or SIADH as well as increased morbidity and mortality.