p38MAPKα Stromal Reprogramming Sensitizes Metastatic Breast Cancer to Immunotherapy

Metastatic breast cancer is an intractable disease that responds poorly to immunotherapy. We show that p38MAPKα inhibition (p38i) limits tumor growth by reprogramming the metastatic tumor microenvironment in a CD4+ T cell-, IFNγ-, and macrophage-dependent manner. To identify targets that further increased p38i efficacy, we utilized a stromal labeling approach and single-cell RNA sequencing. Thus, we combined p38i and an OX40 agonist that synergistically reduced metastatic growth and increased overall survival. Intriguingly, patients with a p38i metastatic stromal signature had better overall survival that was further improved by the presence of an increased mutational load, leading us to ask if our approach would be effective in antigenic breast cancer. The combination of p38i, anti-OX40, and cytotoxic T-cell engagement cured mice of metastatic disease and produced long-term immunologic memory. Our findings demonstrate that a detailed understanding of the stromal compartment can be used to design effective antimetastatic therapies.

SIGNIFICANCE

Immunotherapy is rarely effective in breast cancer. We dissected the metastatic tumor stroma, which revealed a novel therapeutic approach that targets the stromal p38MAPK pathway and creates an opportunity to unleash an immunologic response. Our work underscores the importance of understanding the tumor stromal compartment in therapeutic design. This article is highlighted in the In This Issue feature, p. 1275.

Treatment of HR+/HER2− breast cancer in urban mainland China: results from the CancerMPact Survey 2019

Purpose

To report the treatment utilization patterns for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) breast cancer in urban mainland China (CancerMPact®).

Methods

The results presented are from an online survey conducted in September 2019 with 45 physicians treating breast cancer patients from 11 cities in mainland China.

Results

Surveyed physicians reported that Stage I HR+/HER2(−) breast cancer patients are often treated with surgery alone (42%), whereas the use of surgery in combination with systemic therapy with or without radiotherapy increases in later stages (Stage II 67%, Stage III 77%). Doxorubicin–cyclophosphamide (AC)-based regimens were the most common in both the neoadjuvant and adjuvant settings in HR+/HER2(−) breast cancer patients, across all stages. In metastatic patients, use of surgery and radiotherapy decreases in favor of utilization of systemic therapy alone. Pre- and post-menopausal metastatic patients were frequently treated with hormone therapy or AC-based regimens in first line. Regardless of the first-line therapy administered, capecitabine-based regimens were commonly used in second line. In third line, chemotherapy regimens containing capecitabine or gemcitabine were given to nearly 40% of HR+/HER2(−) breast cancer patients. There were no standard of care regimens established for fourth or greater lines of treatment. In metastatic HR+/HER2(−) breast cancer, physicians reported 50% objective response rates in first-line settings with a progression-free survival of 16 months.

Conclusion

HR+/HER2(−) breast cancer patients in urban mainland China were prescribed chemotherapy regimens more frequently than CDK4/6 inhibitors. Treatment practices varied, with physicians reporting the use of multiple modalities and treatment regimens for their patients.

Abstract 251: Inhibition of stromal p38MAPKalpha triggers innate-adaptive anti-tumor immunity in metastatic breast cancer

Metastases are the main cause of death in breast cancer patients. Among breast metastatic sites, bone is the most prevalent site that can also seed secondary metastases. Moreover, once tumor cells reach the bone, the disease is considered incurable and treatments are only palliative. For this reason, new therapies that limit metastatic growth are desperately needed. We previously showed that pharmacological inhibition of p38MAPKα (p38i) limited visceral and bone metastases in several clinically relevant models of breast cancer metastasis. Indeed, we found that this approach had no impact on tumor cells but instead limited the supporting nature of the stromal compartment. These findings led us to ask how p38i impacted the stromal compartment. Using a novel strategy to segregate tumor-infiltrating from non-tumor-infiltrating stromal cells in the bone metastatic site, we carried out single cell RNA sequencing (scRNA-Seq) to investigate how p38i altered immune and non-immune tumor stroma. Our analyses revealed that p38i treatment shifts tumor-associated macrophages in the bone towards a tumor-suppressive phenotype with increased signatures for IFNγ signaling and adaptive immunity. Importantly, the gene signature we identified in bone macrophages under p38i treatment correlated with better survival among patients with luminal B breast tumors. Given the importance of the p38i gene signature in patient samples, we next depleted macrophages and also blocked IFNγ and found both approaches reversed the p38i anti-tumor effect. Because T cells are an important source of IFNγ in vivo, we next assessed whether T cells were required by p38i to limit tumor growth. Depletion of CD4+ T cells, but not CD8+ T cells, blunted the p38i anti-tumor effect. Although p38i did not increase CD4+ T cell infiltration, p38i increased the percentage of activated CD4+ T cells infiltrating bone metastases. The requirement for CD4+ T cells in our model and the lack of evident OX40 ligand in our scRNA-Seq data led us to ask if p38i could be used in combination with immunotherapy to further limit metastases. Indeed, combination of p38i and agonist anti-OX40 (agOX-40) immunotherapy synergistically reduced metastatic growth and increased overall survival in our mouse models. Finally, because our work revealed no obvious role for CD8+ T cells in this model, we next asked if introduction of a CD8+ T cell antigen could further increase the anti-tumor effects of p38i. We thus modified PyMT-BO1 cells to express ovalbumin, which contains a strong CD8 antigen and combined it with p38i and agOX40. This combination led to a greater than 90% cure rate of mice with metastatic lesions. Although the mechanisms by which inhibition of p38MAPKα shapes the metastatic tumor microenvironment are still under investigation, our findings indicate that metastatic breast cancer patients may benefit from immunotherapy when carried out in combination with p38i.

Citation Format: Douglas Vendas Faget, Xianmin Luo, Qihao Ren, Jiayu Ye, Thomas Cole, Zhangting Yao, Bhavna Murali, Xinming Su, Yalin Xu, Joseph B. Monahan, Katherine N. Weilbaecher, David G. DeNardo, Sheila A. Stewart. Inhibition of stromal p38MAPKalpha triggers innate-adaptive anti-tumor immunity in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 251.

Treatment patterns in non-small-cell lung cancer in China: Results from the CancerMPact survey 2020

PURPOSE

To report the treatment patterns of non-small-cell lung cancer (NSCLC) patients in China based on a survey of physicians (CancerMPact).

METHODS

117 Chinese physicians from 27 cities in mainland China were recruited for an online survey in October 2020, reporting on how they treat their patients across all disease stages, including histology and relevant biomarkers in advanced or metastatic NSCLC.

RESULTS

Surveyed physicians indicated that almost half of their stage I patients were treated with surgery only. For stage II patients, it is more common to treat with surgery in combination with radiation and/or systemic therapy (44.5%), whereas the use of surgery decreases for stage III patients and the overall use of systemic therapy increases (63.4%-68.8%). Physicians are more likely to use systemic therapy alone for stage IV patients (31.4%). Chosen treatment regimens for stage IV NSCLC varied by histology and biomarkers, and several observed treatment patterns differed from the USA. In China, platinum-based chemotherapy is standard of care for treating stage IV NSCLC patients, unlike the USA, where checkpoint inhibitors are the dominant choice in first-line. Further, Chinese physicians reported prescribing biomarker-targeted agents for one-third or less of their patients with EGFR, ALK, ROS-1, or BRAF driver mutations, compared to 60-95% in the USA.

CONCLUSION

As treatment options expand in NSCLC in China, physicians face complex decisions for the treatment of their patients. Treatment patterns often vary, including by disease histology and clinically relevant biomarkers. The standard of care for NSCLC in China also differs from the USA.

Therapy-Induced Senescence Drives Bone Loss

Chemotherapy is important for cancer treatment, however, toxicities limit its use. While great strides have been made to ameliorate the acute toxicities induced by chemotherapy, long-term comorbidities including bone loss remain a significant problem. Chemotherapy-driven estrogen loss is postulated to drive bone loss, but significant data suggests the existence of an estrogen-independent mechanism of bone loss. Using clinically relevant mouse models, we showed that senescence and its senescence-associated secretory phenotype (SASP) contribute to chemotherapy-induced bone loss that can be rescued by depleting senescent cells. Chemotherapy-induced SASP could be limited by targeting the p38MAPK-MK2 pathway, which resulted in preservation of bone integrity in chemotherapy-treated mice. These results transform our understanding of chemotherapy-induced bone loss by identifying senescent cells as major drivers of bone loss and the p38MAPK-MK2 axis as a putative therapeutic target that can preserve bone and improve a cancer survivor's quality of life. SIGNIFICANCE: Senescence drives chemotherapy-induced bone loss that is rescued by p38MAPK or MK2 inhibitors. These findings may lead to treatments for therapy-induced bone loss, significantly increasing quality of life for cancer survivors.

Solution based synthesis of Cu(In,Ga)Se2 microcrystals and thin films

Herein, for the first time, we report the synthesis of quaternary Cu(In,Ga)Se₂ microcrystals (CIGSe MCs) using a facile and economical one-pot heating-up method. The most important parameters such as reaction temperature and time were varied to study their influences on the structural, morphological, compositional and optical properties of the MCs. Based on the results, the formation of CIGSe was initiated from binary β-CuSe and then converted into pure phase CIGSe by gradual incorporation of In³⁺ and Ga³⁺ ions into the β-CuSe crystal lattice. As the reaction time increases, the band gap energy was increased from 1.10 to 1.28 eV, whereas the size of the crystals increased from 0.9 to 3.1 μm. Besides, large-scale synthesis of CIGSe MCs exhibited a high reaction yield of 90%. Furthermore, the CIGSe MCs dispersed in the ethanol was coated as thin films by a drop casting method, which showed the optimum carrier concentration, high mobility and low resistivity. Moreover, the photoconductivity of the CIGSe MC thin film was enhanced by three order magnitude in comparison with CIGSe NC thin films. The solar cells fabricated with CIGSe MCs showed the PCE of 0.59% which is 14.75 times higher than CIGSe NCs. These preliminary results confirmed the potential of CIGSe MCs as an active absorber layer in low-cost thin film solar cells.

Herein, for the first time, we report the synthesis of quaternary Cu(In,Ga)Se₂ microcrystals (CIGSe MCs) using a facile and economical one-pot heating-up method.

Inhibition of the Stromal p38MAPK/MK2 Pathway Limits Breast Cancer Metastases and Chemotherapy-Induced Bone Loss

The role of the stromal compartment in tumor progression is best illustrated in breast cancer bone metastases, where the stromal compartment supports tumor growth, albeit through poorly defined mechanisms. p38MAPKα is frequently expressed in tumor cells and surrounding stromal cells, and its expression levels correlate with poor prognosis. This observation led us to investigate whether inhibition of p38MAPKα could reduce breast cancer metastases in a clinically relevant model. Orally administered, small-molecule inhibitors of p38MAPKα or its downstream kinase MK2 each limited outgrowth of metastatic breast cancer cells in the bone and visceral organs. This effect was primarily mediated by inhibition of the p38MAPKα pathway within the stromal compartment. Beyond effectively limiting metastatic tumor growth, these inhibitors reduced tumor-associated and chemotherapy-induced bone loss, which is a devastating comorbidity that drastically affects quality of life for patients with cancer. These data underscore the vital role played by stromal-derived factors in tumor progression and identify the p38MAPK-MK2 pathway as a promising therapeutic target for metastatic disease and prevention of tumor-induced bone loss.Significance: Pharmacologically targeting the stromal p38MAPK-MK2 pathway limits metastatic breast cancer growth, preserves bone quality, and extends survival. Cancer Res; 78(19); 5618-30. ©2018 AACR.

Human ribonuclease H1 resolves R-loops and thereby enables progression of the DNA replication fork

Faithful DNA replication is essential for genome stability. To ensure accurate replication, numerous complex and redundant replication and repair mechanisms function in tandem with the core replication proteins to ensure DNA replication continues even when replication challenges are present that could impede progression of the replication fork. A unique topological challenge to the replication machinery is posed by RNA-DNA hybrids, commonly referred to as R-loops. Although R-loops play important roles in gene expression and recombination at immunoglobulin sites, their persistence is thought to interfere with DNA replication by slowing or impeding replication fork progression. Therefore, it is of interest to identify DNA-associated enzymes that help resolve replication-impeding R-loops. Here, using DNA fiber analysis, we demonstrate that human ribonuclease H1 (RNH1) plays an important role in replication fork movement in the mammalian nucleus by resolving R-loops. We found that RNH1 depletion results in accumulation of RNA-DNA hybrids, slowing of replication forks, and increased DNA damage. Our data uncovered a role for RNH1 in global DNA replication in the mammalian nucleus. Because accumulation of RNA-DNA hybrids is linked to various human cancers and neurodegenerative disorders, our study raises the possibility that replication fork progression might be impeded, adding to increased genomic instability and contributing to disease.

Abstract 2963: Inhibition of stromal p38MAPK abrogates breast cancer metastasis

Bone metastasis is a devastating and fatal complication of breast cancer for which we lack effective therapies. Thus, identifying therapies that effectively limit metastases will significantly reduce comorbidities and improve long-term survival. Recently we demonstrated that the p38MAPK pathway sustains the pro-tumorigenic senescence-associated secretory phenotype (SASP) and targeting this pathway limits the tumor-promoting capabilities of senescent cells and cancer-associated fibroblasts (CAFs). Because we found that a significant percentage of p38MAPK-dependent SASP factors are expressed in the stroma associated with breast cancer lesions, we asked whether targeting p38MAPK could limit primary and metastatic breast cancer growth. While p38MAPK inhibition modestly limited primary tumor growth, we found that its inhibition significantly reduced breast cancer bone metastases by specifically targeting the stromal compartment. Further, p38MAPK inhibition was as effective as paclitaxel at limiting tumor growth in the bone but in contrast to paclitaxel, which failed to protect from cancer-induced bone loss, p38MAPK inhibition also protected against devastating bone loss. This contrasts our p38MAPK approach from zoledronic acid, which limits bone loss but fails to slow tumor growth in already engrafted tumors. Analysis of the mechanism(s) responsible for this reduced metastasis suggests that p38MAPK inhibition targets reactive and/or senescent osteoblasts within the bones of animals harboring metastatic lesions. Because we find that senescent osteoblasts are present in human bone, we postulate that they promote metastatic outgrowth and thus p38MAPK inhibition limits the pro-metastatic activities of these cells. Finally, we will present recent data from our preclinical model that demonstrates that inhibition of the p38MAPK pathway can drastically reduce metastasis from the primary site. We propose that p38MAPK is an important stromal-specific therapy for breast cancer metastasis to the bone.

Citation Format: Sheila A. Stewart, Bhavna Murali, Qiaho Ren, Xinming Su, Kevin Flannagan, Xianmin Luo, Jasmine Sponagel, Yujie Fu, Elise Alspach, Kathlees Leahy, Roberta Faccio, Kathleen Weilbaecher, Joseph Monahan. Inhibition of stromal p38MAPK abrogates breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2963. doi:10.1158/1538-7445.AM2017-2963

Abstract LB-270: Inhibition of the stromal p38MAPK pathway abrogates breast cancer metastases

Bone metastasis is a devastating and fatal complication of breast cancer for which we lack effective therapies. Thus, identifying therapies that effectively limit metastases will significantly reduce comorbidities and improve long-term survival. Recently we demonstrated that the p38MAPK pathway sustains the pro-tumorigenic senescence-associated secretory phenotype (SASP) and targeting this pathway limits the tumor-promoting capabilities of senescent cells and cancer-associated fibroblasts (CAFs). Because we found that a significant percentage of p38MAPK-dependent SASP factors are expressed in the stroma associated with breast cancer lesions, we asked whether targeting p38MAPK could limit primary and metastatic breast cancer growth. While p38MAPK inhibition modestly limited primary tumor growth, we found that this inhibition significantly reduced breast cancer bone metastases by targeting the stromal compartment. Further, p38MAPK inhibition was as effective as paclitaxel at limiting tumor growth in the bone but in contrast to paclitaxel, which failed to protect from cancer-induced bone loss, p38MAPK inhibition also protected against devastating bone loss. This contrasts our p38MAPK approach from zoledronic acid, which limits bone loss but fails to slow tumor growth in already engrafted tumors. Analysis of the mechanism(s) responsible for this reduced metastasis suggests that p38MAPK inhibition specifically targets reactive and/or senescent osteoblasts within the bones of animals harboring metastatic lesions. Because we find that senescent osteoblasts are present in human bone, we postulate that they promote metastatic outgrowth and thus p38MAPK inhibition limits the pro-metastatic activities of these cells. Finally, we will present recent data from our clinically relevant preclinical model that demonstrates that inhibition of the p38MAPK pathway can drastically reduce metastasis from the primary site. We propose that p38MAPK is an important stromal-specific therapy for breast cancer metastasis to the bone.

Citation Format: Sheila A. Stewart, Bhavna Murali, Xinming Su, Kevin Flanagan, Jasmin Sponagel, Xianmin Luo, Yujie Fu, Elise Alspach, Kathleen Leahy, Joseph Monahan, Katherine Weilbeacher. Inhibition of the stromal p38MAPK pathway abrogates breast cancer metastases. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-270.

Stromal-Initiated Changes in the Bone Promote Metastatic Niche Development

More than 85% of advanced breast cancer patients suffer from metastatic bone lesions, yet the mechanisms that facilitate these metastases remain poorly understood. Recent studies suggest that tumor-derived factors initiate changes within the tumor microenvironment to facilitate metastasis. However, whether stromal-initiated changes are sufficient to drive increased metastasis in the bone remains an open question. Thus, we developed a model to induce reactive senescent osteoblasts and found that they increased breast cancer colonization of the bone. Analysis of senescent osteoblasts revealed that they failed to mineralize bone matrix and increased local osteoclastogenesis, the latter process being driven by the senescence-associated secretory phenotype factor, IL-6. Neutralization of IL-6 was sufficient to limit senescence-induced osteoclastogenesis and tumor cell localization to bone, thereby reducing tumor burden. Together, these data suggest that a reactive stromal compartment can condition the niche, in the absence of tumor-derived signals, to facilitate metastatic tumor growth in the bone.

In vitro comparative evaluation of non-leaves and leaves extracts of Andrographis paniculata on modulation of inflammatory mediators

This study was designed to evaluate and compare the inhibitory property of extracts of Andrographis paniculata leaves [methanolic (AP1), hydroalcoholic (AP2), successive water (AP3)] and non-leaves [methanolic (AP4), hydroalcoholic (AP5), successive water (AP6)] towards inflammatory mediators (NO, IL-1 beta, IL-6, TNF alpha, PGE2, TXB2 and LTB4). Stimulant induced J774A.1 murine macrophages and HL-60 promyelocytic leukemic cells were used to study the inhibitory potential of extracts of A. paniculata on inflammatory mediators. Results revealed that AP1 and AP4 exhibited inhibitory effect on all the inflammatory mediators excluding PGE2 and TNF-alpha. AP2 and AP5 exhibited inhibitory effect towards IL-1 beta, TXB2 and did not show inhibitory effect towards other mediators. However, AP3 and AP6 failed to show inhibitory activity against any of the inflammatory mediators at the tested concentrations. Further, we observed that the magnitude of inhibitory effect displayed by A. paniculata extracts depends on the andrographolide content, although, it does not appear to influence the inhibitory effect towards LTB4 production.

Low phosphate alters lateral root setpoint angle and gravitropism

PREMISE OF THE STUDY

Lateral roots, responsible for water and nutrient uptake, maintain nonvertical angles throughout development. Soil phosphate is one limiting nutrient for plant growth that is known to induce changes to root system architecture, such as increased lateral root formation. This study seeks to determine whether phosphate concentration affects lateral root orientation in addition to its previously described influences on root architecture.

METHODS

Images of intact Arabidopsis root systems were recorded for 24 h, and lateral root tip angles were measured for wild-type and mutant pgm-1 and pin3-1 roots on a full or low phosphate medium. Setpoint angles of unstimulated root systems were determined, as were gravitropic responses of lateral roots over time.

KEY RESULTS

The root system setpoint angles of wild-type and mutant pin3-1 roots showed a shift toward a more vertical orientation on low orthophosphate (Pi) medium. The gravitropic responses of both pgm-1 and pin3-1 roots on low Pi medium was elevated relative to control Pi medium. Mutations in two phosphate transporters with high levels of expression in the root showed a gravitropic response similar to wild-type roots grown on low Pi, supporting a role for Pi status in regulating lateral root gravitropism.

CONCLUSIONS

Lateral root orientation and gravitropism are affected by Pi status and may provide an important additional parameter for describing root responses to low Pi. The data also support the conclusion that gravitropic setpoint angle reacts to nutrient status and is under dynamic regulation.

Reproductive and Fertility Effects of an Extract of Andrographis paniculata in Male Wistar Rats

The possible effect of extract of Andrographis paniculata Nees ( A paniculata) standardized to ≥10% andrographolide, the main bioactive component, on male fertility in albino Wistar rats was evaluated, by orally administering 0, 20, 200, and 1000 mg/kg of body weight per day, for 65 days prior to mating and 21 days during mating. The treated groups showed no signs of dose-dependent toxicity. The body weight gain and feed consumption were not affected at any of the dose levels. The testosterone levels and fertility indices in treatment groups were found to be comparable with that of the control indicating no effect on fertility. Total sperm count and sperm motility were not affected. The testes and epididymides did not show any gross and histopathological changes. Based on these findings, it can be concluded that the no-observed adverse effect level of extract of A paniculata (≥10% andrographolide) was found to be more than 1000 mg/kg per day.

In vitro safety evaluation and anticlastogenic effect of BacoMind on human lymphocytes

OBJECTIVE

BacoMind (BM) is a standardized extract of Bacopa monnieri, which belongs to the family Scrophulariaceae and is a creeping annual plant found throughout the Indian subcontinent. It has been used by Ayurvedic medicinal practitioners in India for almost 3000 years and is classified as a medharasayana, a substance which improves memory and intellect. With the widespread traditional use as well as scientific validation of Bacopa monnieri for nootropic activity, a bioactive-rich unique phytochemical composition-BacoMind was developed from B. monnieri for use as a cognition and memory enhancing agent. The present study aimed to investigate the in vitro toxicity of this formulation of BacoMind on human lymphocytes and to rule out its possible contribution to mutagenicity.

METHODS

In the present investigation the active ingredients present in BM were identified and quantified by high performance liquid chromatography (HPLC) and high performance thin-layer chromatography (HPTLC). Antioxidant and anticlastogenic properties of BM were studied in vitro with and without metabolic activation. Doses of BM were chosen on the basis of mitotic index (MI) and cytokinesis-block proliferation index (CBPI). Clastogenicity assays were performed at 31.2 microg/mL, 62.5 microg/mL, and 125 microg/mL, while the Salmonella reverse mutation assay (Ames test) was performed at doses of 61.72, 185.18, 555.55, 1666.67, and 5000.00 microg/plate.

RESULTS

HPLC and HPTLC analysis of BM revealed the presence of bacoside A3, bacopaside I, bacopaside II, jujubogenin isomer of bacopasaponin C, bacosine, luteolin, apigenin, bacosine, and beta-sitosterol D glucoside. BM demonstrated significant antioxidant activity. The number of chromosomal aberrations and the frequency of micronuclei induced by BM were not statistically significant up to a dose of 62.5 microg/mL. A subsequent dose of 125 microg/mL prior to metabolic activation induced mild clastogenicity, but it was found to be biologically insignificant as this effect was not seen post metabolic activation. BM also demonstrated a dose-dependent protection against the clastogens used in this study using the above tests for clastogenicity. Maximum protection was observed in presence of metabolic activation. Moreover, BM demonstrated no mutagenic effect on the tested strains, as observed in the Ames test.

CONCLUSION

BM protected human lymphocytes against various clastogens. BM also exhibited high antioxidant activity which might be responsible for the observed protective effects against the clastogens since the used clastogens are known to induce their clastogenic effects via production of oxidative radicals.

Tolerance of aged Fischer 344 rats against chlordecone-amplified carbon tetrachloride toxicity

We have investigated the effects of chlordecone 1(CD)+CCl4 combination in adult (3 months), middle aged (14 months), and old aged (24 months) male Fischer 344 (F344) rats. After a non-toxic dietary regimen of CD (10 ppm) or normal powdered diet for 15 days, rats received a single non-toxic dose of CCl4 (100 microl/kg, i.p., 1:4 in corn oil) or corn oil (500 microl/kg, i.p.) alone on day 16. Liver injury was assessed by plasma ALT, AST, and histopathology during a time course of 0-96 h. Liver tissue repair was measured by [3H-CH3]-thymidine (3H-T) incorporation into hepatic nuclear DNA and proliferating cell nuclear antigen (PCNA) immunohistochemistry. Hepatomicrosomal CYP2E1 protein, enzyme activity, and covalent binding of 14CCl4-derived radiolabel were measured in normal and CD fed rats. Exposure to CCl4 alone caused modest liver injury only in 14- and 24-month-old rats but neither progression of injury nor mortality. The CD+CCl4 combination led to 100% mortality in 3-month-old rats by 72 h, whereas none of the 14- and 24-month-old rats died. Both 3- and 14-month-old rats exposed to CD+Cl4 had identical liver injury up to 36 h indicating that bioactivation-mediated CCl4 injury was the same in the two age groups. Thereafter, liver injury escalated only in 3-month-old while it declined in 14-month-old rats. In 24-month-old rats initial liver injury at 6 h was similar to the 3- and 14-month-old rats and thereafter did not develop to the level of the other two age groups, recovering from injury by 96 h as in the 14-month-old rats. Neither hepatomicrosomal CYP2E1 protein nor the associated p-nitrophenol hydroxylase activity or covalent binding of 14CCl4-derived radiolabel to liver tissue differed between the age groups or diet regimens 2 h after the administration of 14CCl4. Compensatory liver tissue repair (3H-T, PCNA) was prompt and robust soon after CCl4 liver injury in the 14- and 24-month-old rats. In stark contrast, in the 3-month-old rats it failed allowing unabated progression of liver injury. These findings suggest that stimulation of early onset and robust liver tissue repair rescue the 14- and 24-month-old F344 rats from the lethal effect of the CD+CCl4 combination.

Pulmonary thromboendarterectomy in a case of hereditary stomatocytosis

We present a case of pulmonary thromboendarterectomy performed successfully in a patient with stomatocytosis. Stomatocytosis is a rare condition of abnormal erythrocyte morphology in which haemolysis and hyperkalaemia occur at cooler temperatures. A 35-yr-old male with stomatocytosis was referred for pulmonary thromboendarterectomy in the context of chronic thromboembolic pulmonary hypertension. He had undergone splenectomy as a child, which rendered him hypercoagulable as the spleen normally removes the haemolysed red cell fragments from blood. By constantly monitoring urine for macroscopic haematuria, arterial and mixed venous blood gas analysis perioperatively and by limiting the period of deep hypothermic circulatory arrest that is normally required for this operation, we were able to perform the operation successfully.

Effect of chronic treatment with losartan on streptozotocin-induced renal dysfunction

The present investigation was undertaken to study the effect of chronic treatment with angiotensin (AT1) receptor antagonist losartan (2 mg/kg, p.o., 6 weeks) on streptozotocin (STZ) induced (45 mg/kg, i.v., single dose) renal dysfunctions in diabetic rats. Injection of streptozotocin produced not only the cardinal symptoms of diabetes mellitus like loss of body weight, hyperglycemia, and hypoinsulinemia but also the renal dysfunctions. Losartan treatment significantly prevented all these changes except STZ-induced hypoinsulinemia. There was a significant elevation of blood pressure in diabetic rats and treatment with losartan significantly brought it back to normal. Renal dysfunction in diabetic rats was characterized by a significant decrease in creatinine clearance, elevated levels of electrolytes and renal hypertrophy. Treatment with losartan prevented these changes. A good correlation was found between biochemical parameters and histopathological abnormalities. Our data suggests that, losartan may be considered as the drug of choice when there is a co-existence of diabetes mellitus and hypertension with compromised kidney function.

Effect of chronic treatment with Enicostemma littorale in non-insulin-dependent diabetic (NIDDM) rats

We have studied the effect of aqueous extract of Enicostemma. littorale (2 g/kg p.o.) daily for 6 weeks in neonatal non-insulin-dependent diabetes mellitus (NIDDM) rats. To induce NIDDM a single dose injection of STZ (70 mg/kg; i.p.) was given to the 5-day-old pups. After 3 months of STZ injection when animals were confirmed as diabetic, E. littorale was administered for 6 weeks. Fasting and fed glucose and insulin levels in NIDDM were significantly (P<0.05) higher than control rats and they were significantly decreased by the treatment with E. littorale. Results of the oral glucose tolerance test (OGTT) showed a significant (P<0.05) decrease in both AUC(glucose) and AUC(insulin) values in NIDDM treated group. Insulin sensitivity (K(ITT)) index of NIDDM control was significantly lower as compared with Wistar control and this was significantly (P<0.05) increased after treatment with E. littorale. Treatment with E. littorale also decreased the elevated cholesterol, triglyceride and creatinine levels observed in NIDDM rats. Our data suggest that aqueous extract of E. littorale is a potent herbal antidiabetic. It produces an increase in insulin sensitivity, normalizes dyslipidaemia and provides nephroprotection in diabetic rats.

Effect of chronic treatment with losartan on streptozotocin induced diabetic rats

Treatment of rats with streptozotocin (STZ, 45mg/kg, i.v.,single dose) produced cardinal symptoms of diabetes mellitus including hyperglycemia, hypoinsulinemia and increase in blood pressure. Treatment with losartan--an angiotensin (AT1) receptor antagonist, 2 mg/kg, po for 6 weeks decreased the blood glucose levels by 16.5%. There was 190% increase in AUCglucose and 59.4% decrease in AUCinsulin in STZ-diabetic rats as compared to control rats. Treatment with losartan caused slight decrease in AUCglucose and slight increase in AUCinsulin. There was no significant difference in insulin sensitivity (K(ITT)) index of STZ-diabetic group as compared to control. Losartan treatment failed to alter these levels significantly. Serum cholesterol and creatinine levels were found to be increased significantly in STZ-diabetic rats. Treatment with losartan significantly prevented the rise in cholesterol and creatinine levels by 20.1 and 81% respectively. The results suggest that losartan produces some beneficial effects in STZ-diabetic rats.

Improvement in insulin sensitivity by losartan in non-insulin-dependent diabetic (NIDDM) rats

The present investigation was undertaken to study the effects of chronic treatment with losartan (2 mg kg(-1)/ day P.O) in neonatal non-insulin-dependent diabetes mellitus (NIDDM) rats. To induce NIDDM single-dose injection of STZ (70 mg kg(-1); i.p.) was given to 5 day old pups. The animals were weaned at 30 days and after a period of 3 months, they were checked for fasting and fed glucose levels to confirm the status of NIDDM. Losartan (2 mg kg(-1); p.o.) was administered for 6 weeks into the confirmed diabetic rats. A group of control animals were also maintained and this group received saline 5 days after birth. Fasting and fed glucose levels in NIDDM rats were significantly higher than control rats. Treatment with losartan in the NIDDM rats caused a significant decrease in insulin levels and reduction in elevated fasting and fed glucose levels. Results of the oral glucose tolerance test (OGTT) showed a significant increase in AUC(glucose)and AUC(insulin)values in NIDDM control rats. Losartan treatment significantly decreased both AUC(glucose)and AUC(insulin)values. Insulin sensitivity (K(ITT)) index of NIDDM control was significantly low as compared to Wistar control animals followed by significant increase in T(1/2)glucose value. Losartan treatment significantly reversed both K(ITT)and T(1/2)glucose value. Our data indicates that losartan increases insulin sensitivity in NIDDM rats.

Effect of chronic treatment with losartan on streptozotocin induced diabetic nephropathy

Angiotensin converting enzyme (ACE) inhibitors produce a number of beneficial effects in a condition where diabetes - mellitus and hypertension co-exist. The present investigation was undertaken to study the effect of chronic treatment with losartan (2mg/kg, p.o.) on streptozotocin (STZ)-induced (45mg/kg, single dose, tail vein) diabetic nephropathy in rats. Treatment of rats with STZ produced a significant loss of body weight, polyuria. polydipsia, hypoinsulinemia, hyperglycemia and increase in blood pressure. There was a significant increase in blood glucose levels in STZ-diabetic rats. Serum cholesterol, creatinine, urea and blood urea nitrogen (BUN) levels were found to be increased significantly in the STZ group diabetic rats. Treatment with losartan significantly prevented the raise in cholesterol, creatinine, urea and blood urea nitrogen levels. Creatinine clearance was significantly less in STZ-diabetic rats as compared to control animals and treatment with losartan significantly increased creatinine clearence. Our data suggest a beneficial effect of losartan in STZ-induced nephropathy in rats.

Anthelmintic activity of essential oil of Ocimum sanctum and eugenol

The essential oil of Ocimum sanctum and eugenol, tested in vitro, showed potent anthelmintic activity in the Caenorhabditis elegans model. Eugenol exhibited an ED(50) of 62.1 microg/ml. Eugenol being the predominant component of the essential oil, is suggested as the putative anthelmintic principle.