Neuroendocrine challenges and clinical outcomes in men with chronic traumatic brain injury: a cross-sectional study.

BACKGROUND AND OBJECTIVES: Marked changes in the hypothalamic-pituitary axis have been documented in patients with traumatic brain injury (TBI). These enduring endocrine challenges could significantly influence the physical and psychological outcomes thereby impacting overall recovery. This study aimed to determine the prevalence and types of endocrine dysfunction in men with chronic TBI and to determine the association of endocrine dysfunction with clinical outcomes. METHODOLOGY: A cross-sectional study that included male participants of 25-45 years (N = 66) with moderate to severe TBI within 6-24 months of injury. Serum Cortisol, Free T4, TSH, Luteinizing hormone, Testosterone, ACTH, Prolactin and IGF-1 were assessed. Glasgow Outcome Scale Extended (GOS-E) and Modified Barthel Index (MBI) scores were also assessed in them. RESULTS: The study cohort comprised male patients with a mean ± age of 32.8 ± 5.7 years. Low IGF-1 levels were most commonly encountered, followed by hypogonadism. Hypopituitarism was present in 56.1%. The proportion of hypogonadism was significantly higher in the group with moderate-total dependence (13/26) as compared to the functionally independent (8/40) group (50% vs. 20%; P = 0.011). Univariate and multivariate logistic regression analysis was used to determine the factors associated with hypopituitarism, revealing that severity of injury (OR = 2.6;) and GOS-E (OR = 3.1) were significant (P < 0.10) on univariate analysis. CONCLUSIONS: This study emphasizes the need to screen TBI patients for neuroendocrine dysfunction during the chronic phases and to establish screening criteria.

Chronic Alcohol Consumption and its Impact on Bone and Metabolic Health - A Narrative Review.

Chronic consumption of a large quantity of alcohol often results in the disruption of the communication between the nervous, endocrine and immune systems leading to profound and serious consequences at the physiological and behavioral levels. The overall impact of excessive alcohol consumption on bone health, metabolic profile and body composition, especially at moderate levels, is not well understood. Chronic excessive alcohol consumption adversely affects bone health through multiple mechanisms leading to low bone mass. It may also be significantly associated with various components on the metabolic syndrome. This review summarizes the findings from published studies that provide consistent evidence on the various effects of alcohol abuse on the bone health and metabolism.

Does hip structural analysis confer additional benefit to routine BMD assessment in postmenopausal women with hip fracture? A study from a tertiary center in southern India.

This study from southern India showed that proximal hip geometry was significantly impaired in postmenopausal women with femoral neck fracture. The trabecular bone score (TBS), which is reflective of bone microarchitecture, was also significantly impaired in patients with fracture. INTRODUCTION: There is limited information with regard to comprehensive bone health in Indian postmenopausal women with neck of femur fracture. We studied the bone mineral density (BMD), trabecular bone score (TBS), proximal hip geometry, and bone mineral biochemistry in postmenopausal women with and without femoral neck fractures. METHODS: This was a cross-sectional study conducted at a tertiary care center in South India. BMD, TBS, and hip structural analysis (HSA) were assessed using a dual-energy X-ray absorptiometry (DXA) scanner. Bone mineral biochemical profiles were also studied. RESULTS: A total of 90 postmenopausal women with acute femoral neck fracture with mean (SD) age of 63.2 (6.1) years and 90 age-matched controls were included. The prevalence of osteoporosis was higher among cases as compared to controls (83.3% vs 47.8%; P < 0.001). Degraded bone microarchitecture (TBS value < 1.200) was more frequent among women with hip fracture as compared to controls (46.7% vs 31.1%; P = 0.032). Cross-sectional moment of inertia (CSMI) was significantly lower at the narrow neck (NN) and inter-trochanteric (IT) region in cases (P < 0.05) and buckling ratio (BR) was significantly higher at all three sites in postmenopausal women with femoral neck fracture as compared controls. Multivariate logistic regression analysis showed that femoral neck osteoporosis, low CSMI at NN and high BR at NN and femoral shaft emerged as factors significantly associated with femoral neck fractures. CONCLUSION: This study highlights that impaired parameters of proximal hip geometry and a low trabecular bone score may be significantly associated with femoral neck fractures in postmenopausal women.

A case of H. pylori infection presenting as refractory hypothyroidism.

We present the case of a 45-year-old lady with long standing hypothyroidism who was euthyroid on replacement for many years, but stopped responding even to supraphysiological doses of LT4 since the last five years. She complained of abdominal discomfort, bloating, and nausea. She did not have diarrhea or weight loss. Levothyroxine absorption test was done which was suggestive of malabsorption and she was started on triple therapy for H. pylori eradication after confirmation of diagnosis. After 10 days of treatment initiation, she developed symptoms of thyrotoxicosis with her supraphysiological dose of LT4, which was then tapered to a lower dose. Euthyroid state was ultimately achieved with lower doses of LT4 replacement.

Familial hypercholesterolemia: The skin speaks.

Familial hypercholesterolaemia (FH) is an autosomal dominant inherited disorder of lipoprotein metabolism caused by defects in the low-density lipoprotein receptor (LDLR) gene. It is characterized by high low-density lipoprotein (LDL) cholesterol levels, premature cardiovascular disease (CVD), and tendon xanthomas. We present the case of a 26-year-old gentleman who presented with multiple nodular eruptions over the extensor aspects of upper and lower limbs and was diagnosed as FH on the basis of positive family history, typical lipid profile abnormalities, and biopsy of the nodule consistent with tendon xanthomas. The diagnosis and management of this case is deftly feasible at the primary care level.

Micturition syncope secondary to urinary bladder paraganglioma.

Paraganglioma of the bladder is a rare tumour accounting for less than 0.06% of all urinary bladder tumours and has varied presentations. It may present with clinical symptoms of phaeochromocytoma, may be non-functioning and asymptomatic or may present with haematuria. Hence, paragangliomas are occasionally misdiagnosed, and this results in unanticipated intraoperative hypertensive crisis. We present the case of a 44-year-old woman with urinary bladder paraganglioma who presented with young onset hypertension, recurrent micturition syncope with prior history of coronary artery disease and stroke. She was stabilised preoperatively with alpha blocking agents and subsequently underwent successful transurethral resection of the same.

Cyclin-dependent kinase 7 is a therapeutic target in high-grade glioma.

High-grade glioma (HGG) is an incurable brain cancer. The transcriptomes of cells within HGG tumors are highly heterogeneous. This renders the tumors unresponsive or able to adapt to therapeutics targeted at single pathways, thereby causing treatment failure. To overcome this, we focused on cyclin-dependent kinase 7 (CDK7), a ubiquitously expressed molecule involved in two major drivers of HGG pathogenesis: cell cycle progression and RNA polymerase-II-based transcription. We tested the activity of THZ1, an irreversible CDK7 inhibitor, on patient-derived primary HGG cell lines and ex vivo HGG patient tissue slices, using proliferation assays, microarray analysis, high-resolution respirometry, cell cycle analysis and in vivo tumor orthografts. The cellular processes affected by CDK7 inhibition were analyzed by reverse transcriptase-quantitative PCR, western blot, flow cytometry and immunofluorescence. THZ1 perturbed the transcriptome and disabled CDK activation, leading to cell cycle arrest at G2 and DNA damage. THZ1 halted transcription of the nuclear-encoded mitochondrial ribosomal genes, reducing mitochondrial translation and oxidative respiration. It also inhibited the expression of receptor tyrosine kinases such as epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor-α (PDGFR-α), reducing signaling flux through the AKT, extracellular-signal-regulated kinase 1/2 (ERK1/2) and signal transducer and activator of transcription 3 (STAT3) downstream pathways. Finally, THZ1 disrupted nucleolar, Cajal body and nuclear speckle formation, resulting in reduced cytosolic translation and malfunction of the spliceosome and thus leading to aberrant mRNA processing. These findings indicate that CDK7 is crucial for gliomagenesis, validate CDK7 as a therapeutic target and provide new insight into the cellular processes that are affected by THZ1 and induce antitumor activity.

Mitochondrial DNA plasticity is an essential inducer of tumorigenesis.

Although mitochondrial DNA has been implicated in diseases such as cancer, its role remains to be defined. Using three models of tumorigenesis, namely glioblastoma multiforme, multiple myeloma and osteosarcoma, we show that mitochondrial DNA plays defining roles at early and late tumour progression. Specifically, tumour cells partially or completely depleted of mitochondrial DNA either restored their mitochondrial DNA content or actively recruited mitochondrial DNA, which affected the rate of tumorigenesis. Nevertheless, non-depleted tumour cells modulated mitochondrial DNA copy number at early and late progression in a mitochondrial DNA genotype-specific manner. In glioblastoma multiforme and osteosarcoma, this was coupled with loss and gain of mitochondrial DNA variants. Changes in mitochondrial DNA genotype affected tumour morphology and gene expression patterns at early and late progression. Importantly, this identified a subset of genes that are essential to early progression. Consequently, mitochondrial DNA and commonly expressed early tumour-specific genes provide novel targets against tumorigenesis.

Antioxidant and Anti-Inflammatory Activities of Kenyan Leafy Green Vegetables, Wild Fruits, and Medicinal Plants with Potential Relevance for Kwashiorkor.

Background. Inflammation, together with related oxidative stress, is linked with the etiology of kwashiorkor, a form of severe acute malnutrition in children. A diet rich in anti-inflammatory and antioxidant phytochemicals may offer potential for the prevention and treatment of kwashiorkor. We selected and assayed five leafy green vegetables, two wild fruits, and six medicinal plants from Kenya for their antioxidant and anti-inflammatory properties. Consensus regarding medicinal plant use was established from ethnobotanical data. Methods. Antioxidant activity and phenolic content were determined using the oxygen radical absorbance capacity (ORAC) assay and Folin-Ciocalteu procedure, respectively. Anti-inflammatory activity was assessed in vitro targeting the inflammatory mediator tumour necrosis factor-alpha (TNF-α). Results. Mangifera indica (leaves used medicinally) showed the greatest antioxidant activity (5940 ± 632 µM TE/µg) and total phenolic content (337 ± 3 mg GAE/g) but Amaranthus dubius (leafy vegetable) showed the greatest inhibition of TNF-α (IC50 = 9 ± 1 µg/mL), followed by Ocimum americanum (medicinal plant) (IC50 = 16 ± 1 µg/mL). Informant consensus was significantly correlated with anti-inflammatory effects among active medicinal plants (r (2) = 0.7639, P = 0.0228). Conclusions. Several plant species commonly consumed by Kenyan children possess activity profiles relevant to the prevention and treatment of kwashiorkor and warrant further investigation.

Mitochondrial DNA copy number is regulated by DNA methylation and demethylation of POLGA in stem and cancer cells and their differentiated progeny.

Mitochondrial DNA (mtDNA) copy number is strictly regulated during differentiation so that cells with a high requirement for ATP generated through oxidative phosphorylation have high mtDNA copy number, whereas those with a low requirement have few copies. Using immunoprecipitation of DNA methylation on 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC), which distinguish between de novo DNA methylation and demethylation, respectively, we set out to determine whether DNA methylation at exon 2 of the human mtDNA-specific polymerase (DNA polymerase gamma A (POLGA)) regulates cell-specific mtDNA copy number in highly proliferative and terminally differentiated cells. Highly proliferative cancer and pluripotent and multipotent cells possessed low mtDNA copy number and were highly methylated at exon 2 of POLGA in contrast to post-mitotic cells. Unlike neural stem cells, cancer cells were unable to differentiate and remained extensively DNA methylated at exon 2 of POLGA. However, mtDNA depletion of cancer cells reduced DNA methylation at exon 2 of POLGA as they replenished mtDNA to form tumours in mice. Glioblastoma cells treated with the DNA demethylation agent 5-azacytidine over 28 days of astrocyte-induced differentiation demethylated exon 2 of POLGA leading to increased mtDNA copy number and expression of the astrocyte endpoint marker glial fibrillary acidic protein (GFAP). However, the demethylation agent vitamin C (VitC) was unable to sustain increased mtDNA copy number and differentiation, as was the case when VitC was withdrawn after short-term treatment. These data demonstrate that DNA demethylation of POLGA is an essential regulator of mtDNA copy number and cellular fate and that cancer cells are only able to modulate DNA methylation of POLGA and mtDNA copy number in the presence of a DNA demethylation agent that inhibits de novo methyltransferase 1 activity.

EGFRvIII-mediated transactivation of receptor tyrosine kinases in glioma: mechanism and therapeutic implications.

A truncation mutant of the epidermal growth factor receptor, EGFRvIII, is commonly expressed in glioma, an incurable brain cancer. EGFRvIII is tumorigenic, in part, through its transactivation of other receptor tyrosine kinases (RTKs). Preventing the effects of this transactivation could form part of an effective therapy for glioma; however, the mechanism by which the transactivation occurs is unknown. Focusing on the RTK MET, we show that MET transactivation in U87MG human glioma cells in vitro is proportional to EGFRvIII activity and involves MET heterodimerization associated with a focal adhesion kinase (FAK) scaffold. The transactivation of certain other RTKs was, however, independent of FAK. Simultaneously targeting EGFRvIII (with panitumumab) and the transactivated RTKs themselves (with motesanib) in an intracranial mouse model of glioma resulted in significantly greater survival than with either agent alone, indicating that cotargeting these RTKs has potent antitumor efficacy and providing a strategy for treating EGFRvIII-expressing gliomas, which are usually refractory to treatment.

Cytotoxic activity of the MK2 inhibitor CMPD1 in glioblastoma cells is independent of MK2.

MAPK-activated protein kinase 2 (MK2) is a checkpoint kinase involved in the DNA damage response. MK2 inhibition enhances the efficacy of chemotherapeutic agents; however, whether MK2 inhibition alone, without concurrent chemotherapy, would attenuate survival of cancer cells has not been investigated. CMPD1 is a widely used non-ATP competitive inhibitor that prevents MK2 phosphorylation. We employed CMPD1 together with MK2 knock-down and ATP-competitive MK2 inhibitor III (MK2i) in a panel of glioblastoma cells to assess whether MK2 inhibition could induce cancer cell death. While CMPD1 was effective at selective killing of cancer cells, MK2i and MK2 knock-down had no effect on viability of glioblastoma cells. CMPD1 treatment induced a significant G2/M arrest but MK2i-treated cells were only minimally arrested at G1 phase. Intriguingly, at doses that were cytotoxic to glioblastoma cells, CMPD1 did not inhibit phosphorylation of MK2 and of its downstream substrate Hsp27. These results suggest that CMPD1 exhibits cytotoxic activity independently of MK2 inhibition. Indeed, we identified tubulin as a primary target of the CMPD1 cytotoxic activity. This study demonstrates how functional and mechanistic studies with appropriate selection of test compounds, combining genetic knock-down and pharmacological inhibition, coordinating timing and dose levels enabled us to uncover the primary target of an MK2 inhibitor commonly used in the research community. Tubulin is emerging as one of the most common non-kinase targets for kinase inhibitors and we propose that potential tubulin-targeting activity should be assessed in preclinical pharmacology studies of all novel kinase inhibitors.

Glioma-specific Domain IV EGFR cysteine mutations promote ligand-induced covalent receptor dimerization and display enhanced sensitivity to dacomitinib in vivo.

A feature of many gliomas is the amplification of the epidermal growth factor receptor (EGFR), resulting in its overexpression. Missense mutations or deletions within the extracellular domain are associated with this amplification and can lead to constitutive activation of the receptor, with the Domain I/II deletion, EGFRvIII, being the most common. These changes have also been associated with increased sensitivity to EGFR inhibition using small molecule inhibitors. We have expressed, in human glioma cells, EGFR containing four glioma-specific EGFR missense mutations within Domain IV (C620Y, C624F, C628Y and C636Y) to analyze their biological properties and sensitivity to EGFR inhibition. One of these mutants, C620Y, exhibited an enhanced basal phosphorylation, which was partially dependent on an EGFR-ligand autocrine loop. All Domain IV mutants responded equally as well as wildtype EGFR (wtEGFR) to ligand stimulation. Biochemical analysis revealed that a pre-formed, disulfide-bonded dimer associated with these mutations was underglycosylated, inactive and cytoplasmically retained. Ligand stimulation resulted in the formation of a tyrosine-phosphorylated, disulfide-bonded dimer for all Domain IV mutants but not for wtEGFR. Following treatment with the next-generation, irreversible pan-ErbB inhibitor dacomitinib, the C620Y, C624F and EGFRvIII mutants were inactivated, covalently dimerized and were retained in the cytoplasm, resulting in cell-surface receptor loss and, for C620Y and C624F, decreased binding of EGF. Dacomitinib treatment significantly reduced the in vivo growth of human glioma xenografts bearing C620Y, but not wtEGFR. Collectively, these data indicate that the unique biochemical traits of Domain IV EGFR cysteine mutants can be exploited for enhanced sensitivity to EGFR small molecule inhibitors, with potential clinical applications.

Combination gefitinib and methotrexate treatment for non-tubal ectopic pregnancies: a case series.

Non-tubal ectopic pregnancies are a rare subgroup of ectopic pregnancies implanted at sites other than the Fallopian tube. Mortality from non-tubal ectopic pregnancies is higher compared with that for tubal ectopic pregnancies, and they are becoming more common, partly due to the rising incidence of Caesarean sections and use of assisted reproductive technologies. Non-tubal ectopic pregnancies can be especially difficult to treat. Surgical treatment is complex, and follow-up after medical treatment is usually protracted. There is therefore a need for more effective medical therapies to resolve non-tubal ectopic pregnancies and reduce operative intervention. We have recently reported successful use of combination gefitinib (an orally available epidermal growth factor receptor inhibitor) and methotrexate for treatment of tubal pregnancies. To our knowledge, this combination has not been used to treat non-tubal pregnancies. Here we report the use of combination gefitinib and methotrexate to treat eight women with stable, non-tubal ectopic pregnancies at two tertiary academic teaching hospitals (Edinburgh, UK and Melbourne, Australia); five interstitial and three Caesarean section scar ectopic pregnancies. Pretreatment serum hCG levels ranged from 2458 to 48 550 IU/l, and six women had pretreatment hCG levels >5000 IU/l. The women were co-administered 1-2 doses of i.m. methotrexate (50 mg/m² on Day 1, ± Day 4 or Day 7) with seven once daily doses of oral gefitinib (250 mg). The women were monitored until complete resolution of the ectopic pregnancy, defined as a serum hCG <15 IU/l. Time to resolution (days from first methotrexate dose until serum hCG <15 IU/l), safety and tolerability, complication rates and subsequent fertility outcomes were also recorded. All eight women were successfully treated with combination gefitinib and methotrexate. The most common side effects were transient acne/rash and diarrhoea, known side effects of gefitinib. All women promptly resumed menstruation and importantly, three women subsequently conceived spontaneously. Two have delivered a healthy infant at term and the third is currently in her second trimester of pregnancy. Hence, our case series supports a future clinical trial to determine the efficacy of combination gefitinib and methotrexate to treat non-tubal ectopic pregnancies.

The regulation of mitochondrial DNA copy number in glioblastoma cells.

As stem cells undergo differentiation, mitochondrial DNA (mtDNA) copy number is strictly regulated in order that specialized cells can generate appropriate levels of adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS) to undertake their specific functions. It is not understood whether tumor-initiating cells regulate their mtDNA in a similar manner or whether mtDNA is essential for tumorigenesis. We show that human neural stem cells (hNSCs) increased their mtDNA content during differentiation in a process that was mediated by a synergistic relationship between the nuclear and mitochondrial genomes and results in increased respiratory capacity. Differentiating multipotent glioblastoma cells failed to match the expansion in mtDNA copy number, patterns of gene expression and increased respiratory capacity observed in hNSCs. Partial depletion of glioblastoma cell mtDNA rescued mtDNA replication events and enhanced cell differentiation. However, prolonged depletion resulted in impaired mtDNA replication, reduced proliferation and induced the expression of early developmental and pro-survival markers including POU class 5 homeobox 1 (OCT4) and sonic hedgehog (SHH). The transfer of glioblastoma cells depleted to varying degrees of their mtDNA content into immunocompromised mice resulted in tumors requiring significantly longer to form compared with non-depleted cells. The number of tumors formed and the time to tumor formation was relative to the degree of mtDNA depletion. The tumors derived from mtDNA depleted glioblastoma cells recovered their mtDNA copy number as part of the tumor formation process. These outcomes demonstrate the importance of mtDNA to the initiation and maintenance of tumorigenesis in glioblastoma multiforme.

Immunonutrition in patients undergoing major upper gastrointestinal surgery: a prospective double-blind randomised controlled study.

INTRODUCTION: current studies suggest immunonutrition decreases the inflammatory process, infection rates and reduces length of hospital stay in surgical patients, however studies are often conducted on heterogeneous groups of patients with varying composition of the immuno-nutrition. We aim to investigate the effect of immunonutrition on patients undergoing major upper gastrointestinal surgery by assessment of (i) the inflammatory and immune response and (ii) changes in clinical outcome when compared to a randomised control receiving conventional feeding. METHOD: a prospective double-blind randomised controlled study was undertaken to compare a feed supplemented with glutamine, arginine, -3 fatty acids and tributyrin, vitamin C, E and B-carotene and micronutrients (zinc, selenium and chromium) to an isonitrogenous, isocaloric control feed in patients undergoing major upper GI surgery. The primary end-points were defined as C-reactive protein (CRP), prealbumin and retinol binding protein (RBP) levels. Secondary end-points included performance scoring systems, length of hospital stay, adverse events and protein and nutrient assays. Variables were measured pre-operatively and routinely up to the 4th post-operative day. RESULTS: there was no statistically significant change in primary end-points between the immunonutrition group and the control group. There was no difference in length of hospital stay between the groups. The vitamin C level in the study group was significantly higher at the end of the study period. Both groups tolerated the feeds well with adequate target feeding rate. There were no other significant changes in clinical outcomes between the two groups. CONCLUSION: this study has not shown a benefit of immunonutrition through changes in inflammatory or nutritional markers, a decrease in length of hospital stay, or other morbidity. This may be because of inadequate numbers recruited to the study. Further, multi-centre, randomised trials on homogeneous patient groups are necessary to investigate the role of immunonutrition in major upper GI surgery.

The prepare pilot RCT of home-based progressive resistance exercises for venous leg ulcers.

OBJECTIVE: To establish the feasibility of conducting a home-based progressive resistance exercise programme to improve calf muscle pump function in community-based patients with venous leg ulcers. METHOD: Participants were randomised to receive a 12-week progressive resistance exercise programme using heel raises in addition to compression. The control was usual care in addition to compression. Randomisation was stratified by ulcer duration and ulcer size. Air plethysmography was used to determine changes in calf muscle pump function from baseline. Changes in ulcer parameters were measured using the SilhouetteMobile device. RESULTS: Forty participants were randomised. There were significantly greater improvements in ejection fraction of the calf muscle in the exercise group compared with the control (usual care) group (mean difference 18.5%, 95% CI 0.03 to 36.6%, p<0.05). Other parameters improved in the exercise group but the mean differences were not significant. Adherence with prescribed exercises was 81% and there was no significant difference in the numbers reporting adverse events. There were also no significant differences in ulcer healing parameters (change in area, percentage change in area, number healed at 12 weeks, time to healing). CONCLUSION: A community-based randomised trial of progressive resistance exercise is feasible. The prescribed exercises appeared to increase ejection fraction, but the effect of exercise on ulcer healing requires further investigation.

In vitro sensitivity testing of minimally passaged and uncultured gliomas with TRAIL and/or chemotherapy drugs.

TRAIL/Apo-2L has shown promise as an anti-glioma drug, based on investigations of TRAIL sensitivity in established glioma cell lines, but it is not known how accurately TRAIL signalling pathways of glioma cells in vivo are reproduced in these cell lines in vitro. To replicate as closely as possible the in vivo behaviour of malignant glioma cells, 17 early passage glioma cell lines and 5 freshly resected gliomas were exposed to TRAIL-based agents and/or chemotherapeutic drugs. Normal human hepatocytes and astrocytes and established glioma cell lines were also tested. Cross-linked TRAIL, but not soluble TRAIL, killed both normal cell types and cells from three tumours. Cells from only one glioma were killed by soluble TRAIL, although only inefficiently. High concentrations of cisplatin were lethal to glioma cells, hepatocytes and astrocytes. Isolated combinations of TRAIL and chemotherapy drugs were more toxic to particular gliomas than normal cells, but no combination was generally selective for glioma cells. This study highlights the widespread resistance of glioma cells to TRAIL-based agents, but suggests that a minority of high-grade glioma patients may benefit from particular combinations of TRAIL and chemotherapy drugs. In vitro sensitivity assays may help identify effective drug combinations for individual glioma patients.

The potency of immunomodulatory herbs may be primarily dependent upon macrophage activation.

Standardized extracts of Echinacea, cat's claw, and saw palmetto were each evaluated for ability to activate macrophage and natural killer cells, in vitro, using two independent measures of activation for each immune cell population. A standard series of exposure concentrations were tested for each herbal extract in a panel of four assays that evaluated macrophage phagocytosis, macrophage synthesis of interleukin-12, natural killer (NK) cell cytocidal activity (synthesis of granzyme B), and NK cell synthesis of interferon-gamma. Macrophage phagocytosis was stimulated by all three herbs tested: saw palmetto (up to 2.3-fold, P < .05), Echinacea (up to 3.6-fold, P < .01), and cat's claw (up to 4.7-fold, P < .01). Additionally, NK cell synthesis of interferon-gamma was stimulated by saw palmetto (up to 6.3-fold, P < .01) and Echinacea (up to 8.1 fold, P < .01) but not by exposure to cat's claw. None of the three herbs stimulated macrophage synthesis of interleukin-12 or NK cell synthesis of granzyme B. Comparison of the in vitro data with our earlier observations that cat's claw and Echinacea (but not saw palmetto) were each effective in reducing B16/F10 lung tumor colony formation in C57BL/6J mice suggests macrophage activation is the primary means by which these herbs modulate the immune system. Thus, macrophage activation (phagocytosis) may provide a potentially higher throughput method to identify herbal extracts with in vivo stimulatory effects.

Preclinical analysis of the analinoquinazoline AG1478, a specific small molecule inhibitor of EGF receptor tyrosine kinase.

The tyrphostin 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478) is a potent and specific inhibitor of EGFR tyrosine kinase whose favourable preclinical profile supports progression towards clinical trials. Microphysiometric evaluation revealed a short (<24 min) effective inhibition of cellular receptor response to EGF challenge in BaF/ERX cells indicating a need to maintain sustained levels of inhibitor. Initial pharmacokinetic evaluation in mice of novel AG1478 formulations in a beta-cyclodextrin (Captisol) showed monoexponential elimination from plasma (half-life 30 min) following subcutaneous administration. A two-fold dose escalation gave a 2.4-fold increase in the total AUC. Bolus i.v. and 6 h continuous infusion were investigated in rats to mimic a more clinically relevant administration regimen. Drug elimination following bolus i.v. administration was biphasic (terminal elimination half-life 30-48 min). The linear relationship between dose and AUC(0-->infinity) (r2=0.979) enabled the prediction of infusion rates and doses for sustained delivery using continuous 6 h infusions, where steady state was reached in 120 min. Plasma levels of AG1478>10 microM were achieved over the duration of the infusion. At the lowest dose, plasma drug levels after the cessation of infusion declined with a half-life of approximately 43 min. EGFR activity, measured both by autophosphorylation and downstream signalling, was inhibited in a dose-dependent manner by injection of AG1478 in mice bearing xenografts of the human glioblastoma cell line U87MG.delta2-7, which expresses a constitutively active variant of the EGF receptor. Taken together, these experiments provide essential data to assess the anti-tumour efficacy of AG1478 and will assist in the rational design of dose regimens for clinical studies.