Alpha 1-adrenoceptor subtypes linked to different mechanisms for increasing intracellular Ca2+ in smooth muscle

Receptor-mediated increases in intracellular Ca2+ levels can be caused by release from intracellular organelles and/or influx from the extracellular fluid. Noradrenaline (NA) released from sympathetic nerves acts on alpha 1-adrenoceptors to increase cytosolic Ca2+ and promote smooth muscle contraction. In many cells activation of alpha 1-adrenoceptors causes formation of inositol 1,4,5-trisphosphate which promotes Ca2+ release from intracellular stores. The mechanism by which receptor activation opens cell surface Ca2+ channels is not known, although in some cases it may be secondary to formation of inositol phosphates or release of stored intracellular Ca2+ (ref. 3). However, alpha 1-adrenoceptors have recently been shown to have different pharmacological properties in different tissues, and it has been proposed that different alpha 1-adrenoceptor subtypes may control mobilization of intracellular Ca2+ and gating of extracellular Ca2+ influx. We here report evidence for two subtypes of alpha 1-adrenoceptors which cause contractile responses through different molecular mechanisms. One subtype stimulates inositol phosphate (InsP) formation and causes contractions which are independent of extracellular Ca2+, and the other does not stimulate inositol phosphate formation and causes contractions which require the influx of extracellular Ca2+ through dihydropyridine-sensitive channels. These results suggest that neurotransmitters and hormones may control Ca2+ release from intracellular stores and influx through voltage-gated membrane channels through distinct receptor subtypes.

Evidence of radiographic benefit of treatment with infliximab plus methotrexate in rheumatoid arthritis patients who had no clinical improvement: a detailed subanalysis of data from the anti-tumor necrosis factor trial in rheumatoid arthritis with concomitant therapy study

OBJECTIVE

To assess the relationship between inflammation and joint destruction in rheumatoid arthritis (RA) patients who have not responded clinically to treatment.

METHODS

Changes from baseline to week 54 in clinical variables and measures of radiographic progression were compared between patients who received infliximab (3 mg/kg or 10 mg/kg every 4 or 8 weeks) plus methotrexate (MTX) and those who received MTX plus placebo in the Anti-Tumor Necrosis Factor Trial in RA with Concomitant Therapy trial.

RESULTS

At week 54, patients who did not show 20% improvement by American College of Rheumatology criteria (ACR20 nonresponders) while receiving infliximab plus MTX exhibited mild but statistically significant improvement in clinical variables, including the 28-joint Disease Activity Score (DAS28) (P < 0.001), tender joint count (P = 0.014), swollen joint count (P < 0.001), and C-reactive protein (CRP) level (P < 0.001). Whereas the clinical and CRP changes among ACR20 nonresponders to infliximab plus MTX were small and much lower than among ACR20 responders to this treatment, radiographic progression among ACR20 nonresponders to infliximab plus MTX was significantly inhibited (P < 0.001) compared with ACR20 nonresponders to MTX plus placebo. Radiographic progression was much greater in patients receiving MTX plus placebo than in patients receiving infliximab plus MTX, irrespective of ACR response status (mean change in modified Sharp/van der Heijde score 6.0 in ACR20 responders and 7.2 in ACR20 nonresponders in the MTX plus placebo-treated group, versus 0.1 in ACR20 responders and 1.2 in ACR20 nonresponders in the infliximab plus MTX-treated group). Furthermore, among patients who were ACR20 nonresponders through week 54, patients who were DAS nonresponders at weeks 30 and 54, and patients without any improvement in individual clinical variables, those receiving infliximab plus MTX still demonstrated inhibition of structural damage that was statistically significant compared with inhibition in patients who received MTX plus placebo (P < 0.05 to P < 0.001).

CONCLUSION

Even in patients without clinical improvement, treatment with infliximab plus MTX provided significant benefit with regard to the destructive process, suggesting that in such patients these 2 measures of disease are dissociated.

Prognostic significance of a novel hypoxia-regulated marker, carbonic anhydrase IX, in invasive breast carcinoma

PURPOSE

To assess the frequency of expression and the prognostic significance of a hypoxia-regulated marker, carbonic anhydrase IX (CA IX), in a cohort of patients with invasive breast cancer.

PATIENTS AND METHODS

CA IX expression was evaluated by immunohistochemistry with a murine monoclonal antibody, M75, in a series of 103 women treated surgically for invasive breast cancer. The majority of patients were treated with adjuvant hormonal or chemotherapy. The frequency of CA IX expression, its association with recognized prognostic factors, and the relationship with outcome was evaluated by univariate and multivariate statistical analyses.

RESULTS

CA IX expression was present in 49 (48%) of 103 cases. The level of CA IX expression was found to be significantly associated with tumor necrosis (P <.001), higher grade (P =.02), and negative estrogen receptor status (P <.001). Furthermore, CA IX expression was associated with a higher relapse rate (P =.004) and a worse overall survival (P =.001). By multivariate analysis, CA IX was also shown to be an independent predictive factor for overall survival (hazard ratio, 2.61; 95% confidence interval, 1.01 to 6.75, P =.05).

CONCLUSION

CA IX expression was associated with worse relapse-free survival and overall survival in an unselected cohort of patients with invasive breast carcinoma. The potential role of CA IX as a marker of hypoxia within breast carcinomas was also indicated by a significant association with necrosis. Further work assessing its prognostic significance in breast cancer is warranted, particularly interactions with radiotherapy and chemotherapy resistance.

A precision measurement of the mass of the top quark

The standard model of particle physics contains parameters--such as particle masses--whose origins are still unknown and which cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark (M(t)) and W boson (M(W)) constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of M(t) can therefore indicate where to look for the Higgs, and indeed whether the hypothesis of a standard model Higgs is consistent with experimental data. As top quarks are produced in pairs and decay in only about 10(-24) s into various final states, reconstructing their masses from their decay products is very challenging. Here we report a technique that extracts more information from each top-quark event and yields a greatly improved precision (of +/- 5.3 GeV/c2) when compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the only other measurements available, the new world average for M(t) becomes 178.0 +/- 4.3 GeV/c2. As a result, the most likely Higgs mass increases from the experimentally excluded value of 96 to 117 GeV/c2, which is beyond current experimental sensitivity. The upper limit on the Higgs mass at the 95% confidence level is raised from 219 to 251 GeV/c2.

Human umbilical cord mesenchymal stem cell derived exosomes encapsulated in functional peptide hydrogels promote cardiac repair

Stem cell-derived exosomes have been recognized as a potential therapy for cardiovascular disease. However, the low retention rate of exosomes after transplantation in vivo remains a major challenge in clinical applications. The aim of this study is to investigate whether human umbilical cord mesenchymal stem cell derived exosomes (UMSC-Exo) encapsulated in functional peptide hydrogels could increase the retention and stability of exosomes and improve heart function in a rat myocardial infarction model. Our results demonstrated that the PA-GHRPS peptide protected H9C2 cells from H2O2-induced oxidative stress. The gelatinization ability of PA-GHRPS can be enhanced by peptide NapFF. Therefore, these two peptides were mixed to form the PGN hydrogel, which was used to encapsulate exosomes. Our data showed that the PGN hydrogel was able to encapsulate exosomes effectively and ensured a stable and sustained release of exosomes. The exosome/PGN hydrogel mixture was injected into the infarcted border zone of rat hearts. Compared to the exosome treatment alone, the mixture improved the myocardial function by reducing inflammation, fibrosis and apoptosis, and by promoting angiogenesis. The strategy used in this study provided a practical and effective method to harness exosomes for myocardial regeneration.

Radiographic changes in rheumatoid arthritis patients attaining different disease activity states with methotrexate monotherapy and infliximab plus methotrexate: the impacts of remission and tumour necrosis factor blockade

OBJECTIVE

To examine the association of radiographic progression and disease activity states in patients with rheumatoid arthritis (RA) treated with methotrexate with or without infliximab.

METHODS

Patients (n = 1049) with active RA for 3 years or less and no previous methotrexate treatment were randomly assigned (4 : 5 : 5) to receive methotrexate plus placebo or methotrexate plus infliximab 3 or 6 mg/kg at weeks 0, 2 and 6, and every 8 weeks thereafter to week 46. Disease activity was classified by the simplified disease activity index as remission (< or =3.3), low (>3.3 to < or =11), moderate (>11 to < or =26), high (>26). Radiographic progression was measured as a change from baseline to week 54 in total Sharp score.

RESULTS

At weeks 14 and 54, more patients receiving methotrexate plus infliximab than methotrexate plus placebo were in remission (10.7% versus 2.8% week 14; 21.3% versus 12.3% week 54; p<0.001 for both). Methotrexate plus placebo halted radiographic progression only if patients achieved remission within 3 months, whereas methotrexate plus infliximab also halted or minimised progression in patients with low or moderate activity, respectively. Patients with persistently high disease activity levels had much less progression of joint damage if treated with methotrexate plus infliximab versus methotrexate monotherapy. Even with infliximab plus methotrexate there was a direct relationship between disease activity and radiographic changes, although the slope was deflected when compared with methotrexate monotherapy.

CONCLUSION

With methotrexate, joint damage progresses even at low and moderate disease activity levels, whereas methotrexate plus infliximab inhibits radiographic progression across all disease activity states.

Direct observations of ligand dynamics in hemoglobin by subpicosecond infrared spectroscopy

The photodissociation of CO from HbCO at ambient temperature is studied by means of a femtosecond IR technique. The bleaching of the FeCO absorption and the appearance of a new IR absorption near that of free CO are both observed at 300 fs after optical excitation. The bleach does not recover on the time scale of a few picoseconds but does recover by approximately 4% within 1 ns, which suggests that a barrier to recombination is formed within a few picoseconds. The CO spectrum does not change significantly between 300 fs and 1 ns, suggesting that the CO quickly finds some locations in the heme pocket that are not more than a few angstroms from the iron. The de-ligated CO appears in its ground vibrational level. There is evidence that 85 +/- 10% of this CO remains in the heme pocket at 1 ns; it probably resides there for 50 ns. The flow of excess vibrational energy from the heme to the solvent was directly observed in the IR experiments. The heme cools within 1-2 ps while thermal disruption of the surrounding solvent structure requires approximately 30 ps.

Lifetime tobacco, alcohol and other substance use in adolescent Minnesota twins: univariate and multivariate behavioral genetic analyses

AIMS

We sought to estimate the contribution of genetic and environmental factors to adolescent tobacco, alcohol and other substance use.

DESIGN, SETTING AND PARTICIPANTS

The sample consisted of 327 monozygotic and 174 like-sex dizygotic twin pairs born in Minnesota and aged 17-18 years at time of assessment. Biometrical methods were used to estimate the contribution of additive genetic, shared and non-shared environmental factors to adolescent substance use.

MEASUREMENTS

As part of a day-long psychological assessment, adolescent twins completed a computerized substance use interview to determine whether they had ever used tobacco, alcohol or other illicit drugs.

FINDINGS

The heritability for the liabilities to tobacco, alcohol and other drug use was estimated to be 59%, 60% and 33% among males, and 11%, 10% and 11% among females. However, the gender difference was not statistically significant. Estimates of shared environmental effect were substantial and insignificantly higher among females (71%, 68% and 36%, respectively) than among males (18%, 23% and 23%, respectively). The covariation among the three substance use phenotypes could be accounted for by a common underlying substance use factor. Estimates of the contributions of genetic, shared environmental and non-shared environmental factors to variance in this factor were 23% 63% and 14%, respectively.

CONCLUSIONS

These findings add to the growing behavioral genetic literature indicating that adolescent initiation of substance use, a powerful predictor of adult substance use diagnosis, is influenced primarily by environmental rather than genetic factors.

Imbalance between pro- and anti-inflammatory cytokines, and between Th1 and Th2 cytokines in depressed patients: the effect of electroacupuncture or fluoxetine treatment

BACKGROUND

An increase in inflammatory response and an imbalance between T-helper (Th) 1 and 2 functions have been implicated in major depression. The aims of the present study were to 1) study the relationship between pro- and anti-inflammatory cytokines and between Th1 and Th2 produced cytokines in depressed patients and 2) evaluate and compare the effect of treatments with electroacupuncture (EA) and fluoxetine on these cytokines.

METHODS

95 outpatients with major depressive disorder were treated for 6 weeks with EA, fluoxetine or placebo. Hamilton Depression Rating Scale (HDRS) and Clinical Global Impression (CGI) were used to assess severity and therapeutic effects. 30 volunteers served as controls. Serum cytokine concentrations were measured by ELISA.

RESULTS

Increased proinflammatory cytokine interleukin (IL)-1beta and decreased anti-inflammatory cytokine IL-10 were found in the depressed patients. By contract, Th1 produced proinflammatory cytokines, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma were decreased, and Th2 produced cytokine IL-4 was significantly increased in depressed patients. The ratio of IFN/IL-4 was also increased. Both acupuncture and fluoxetine treatments, but not the placebo, reduced IL-1beta concentrations in responders. However, only acupuncture attenuated TNF-alpha concentration and INF-gamma/IL-4 ratio towards the control level.

DISCUSSION

These results suggest that an imbalance between the pro- and anti-inflammatory cytokines (IL-1 and IL-10), and between Th1 and Th2 cytokines (INF-gamma or TNF-alpha and IL-4) occurred in untreated depressed patients. Both EA and fluoxetine had an anti-inflammatory effect by reducing IL-1beta. EA treatment also restored the balance between Th1 and Th2 systems by increasing TNF-alpha and decreasing IL-4.

Prognostic indicators for gastrointestinal stromal tumours: a clinicopathological and immunohistochemical study of 108 resected cases of the stomach

AIMS

Whether immunohistochemical markers increase accuracy in predicting prognosis for gastrointestinal stromal tumours (GISTs) remains uncertain. However, past studies have used only small, heterogeneous patient groups. Our aim was to test previously studied and more novel morphological features as well as four immunohistochemical markers as prognostic indicators amongst a large cohort of surgically resected, gastric GISTs.

METHODS AND RESULTS

Tissues from 127 gastric mesenchymal tumours were collected retrospectively and subjected to repeat histological assessment and immunophenotyping. Further immunohistochemistry was performed for Ki67, p53, Bcl-2 and cyclin D1. Complete follow-up data were collected for 108 patients with immunophenotyped diagnoses of GIST (i.e. c-kit+ tumours). At the census point, 52 patients were alive, 24 had died from their GISTs and the remainder of other causes. Univariate analysis showed the following predicted for shorter disease-specific survival: size > or =50 mm; necrosis, no intratumoral lymphocytes; mitotic count > or =5/50 high power fields; Ki67 labelling index > or =5%; p53 immunopositivity. Of these variables, multivariate analyses showed only mitotic count and, to a lesser extent, Ki67 labelling to be independent prognostic indicators.

CONCLUSIONS

Mitotic count remains the best predictor of outcome following surgical resection of gastric GISTs. Ki67 immunohistochemistry does not provide better prognostication and p53, Bcl-2 and cyclin D1 immunohistochemistry provide no additional prognostication.

Subtypes of alpha 1-adrenoceptors in rat blood vessels

Two alpha 1-adrenoceptor subtypes (alpha 1A and alpha 1B) have been distinguished by competitive antagonists and the alkylating agent chloroethylclonidine. The chloroethylclonidine-insensitive subtype (alpha 1A) has been suggested to selectively activate Ca2+ influx through dihydropyridine-sensitive channels in smooth muscle. We compared the effects of chloroethylclonidine and nifedipine on contractile responses to norepinephrine (NE) in rat blood vessels. Pretreatment with chloroethylclonidine caused a large shift to the right and decrease in maximum for NE-induced contractions of rat aorta, however, nifedipine had no effect in this tissue. Chloroethylclonidine had no effect on NE-induced contractions of rat renal arteries, which were almost completely abolished by nifedipine. Both chloroethylclonidine and nifedipine partially attenuated NE-induced contractions in rat mesenteric artery and portal vein. Addition of nifedipine abolished residual contractions remaining after chloroethylclonidine pretreatment in all four types of vessels. The pA2 for the competitive antagonist WB 4101 was highest in renal artery and lowest in aorta. These results suggest that the sensitivity of rat blood vessels to chloroethylclonidine is inversely related to their sensitivity to nifedipine, and support the existence of two alpha 1-adrenoceptor subtypes in rat blood vessels. Rat aorta appears to contain primarily alpha 1B receptors, renal artery primarily alpha 1A, and mesenteric artery and portal vein mixtures alpha 1A of and alpha 1B.

Carbonic anhydrase XII is a marker of good prognosis in invasive breast carcinoma

Hypoxia and pH influence gene expression in tumours, and it is becoming increasingly clear that the pattern of genes expressed by a tumour determines its growth and survival characteristics. Hypoxia-inducible factor-1 (HIF-1) is a key mediator of the cellular response to hypoxia and high HIF-1 expression has been identified as a poor prognostic factor in tumours. Recently, we identified the tumour-associated carbonic anhydrases (CA), CA9 and CA12 as hypoxia-inducible in tumour cell lines. Furthermore, we identified CA IX to be a poor prognostic factor in breast cancer. The aim of this study was to assess the prognostic significance of CA XII. CA XII expression was studied by immunohistochemistry in a series of 103 cases of invasive breast cancer and any association with recognised prognostic factors or relation with the outcome was examined. CA XII expression was present in 77 out of 103 (75%) cases and was associated with lower grade (P=0.001), positive estrogen receptor status (P<0.001), and negative epidermal growth factor receptor status (P<0.001). Furthermore, although CA XII expression was associated with an absence of necrosis (P<0.001), expression of CA XII in some high-grade tumours was induced in regions directly adjacent to morphological necrosis. Additionally, using univariate analysis, CA XII positive tumours were associated with a lower relapse rate (P=0.04) and a better overall survival (P=0.01). In conclusion, CA XII expression is influenced both by factors related to differentiation and hypoxia in breast cancer in vivo and CA XII expression is associated with a better prognosis in an unselected series of invasive breast carcinoma patients.

The effects of the selective progesterone receptor modulator asoprisnil on the morphology of uterine tissues after 3 months treatment in patients with symptomatic uterine leiomyomata

BACKGROUND

Asoprisnil is a selective progesterone receptor modulator with mixed progesterone agonist/antagonist activity which controls uterine bleeding via an endometrial effect. This study examined full-thickness endometrial, leiomyoma and myometrial morphology in hysterectomy specimens from patients with uterine leiomyomata, after treatment with asoprisnil for 3 months.

METHODS

In this double-blind, randomized, placebo-controlled study, 33 subjects with uterine leiomyomata were randomized to receive asoprisnil 10, 25 mg or placebo for an average of 95 days prior to hysterectomy. Samples of endometrium, myometrium and leiomyoma tissue were subjected to systematic morphological assessment with quantification of mitotic activity.

RESULTS

In patients treated with 10 or 25 mg asoprisnil, a unique pattern called 'non-physiologic secretory effect' was evident in endometrium, recognizable through partially developed secretory glandular appearances and stromal changes. Endometrial thickness was decreased, and there were low levels of mitotic activity in endometrial glands and stroma. Unusual thick-walled muscular arterioles and prominent aggregations of thin-walled vessels were present in endometrial stroma, but not in myometrium or non-endometrial vascular beds. Mitotic activity was decreased in leiomyomata.

CONCLUSIONS

Asoprisnil induces unique morphological changes and is associated with low levels of glandular and stromal proliferation in endometrium, and in leiomyomata. These changes are likely to contribute to the amenorrhoea experienced after exposure to the medication.

Exoplanet detection. A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary

Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

Extracellular vesicles in cardiovascular disease: Biological functions and therapeutic implications

Extracellular vesicles (EVs), including exosomes and microvesicles, are lipid bilayer particles naturally released from the cell. While exosomes are formed as intraluminal vesicles (ILVs) of the multivesicular endosomes (MVEs) and released to extracellular space upon MVE-plasma membrane fusion, microvesicles are generated through direct outward budding of the plasma membrane. Exosomes and microvesicles have same membrane orientation, different yet overlapping sizes; their cargo contents are selectively packed and dependent on the source cell type and functional state. Both exosomes and microvesicles can transfer bioactive RNAs, proteins, lipids, and metabolites from donor to recipient cells and influence the biological properties of the latter. Over the last decade, their potential roles as effective inter-tissue communicators in cardiovascular physiology and pathology have been increasingly appreciated. In addition, EVs are attractive sources of biomarkers for the diagnosis and prognosis of diseases, because they acquire their complex cargoes through cellular processes intimately linked to disease pathogenesis. Furthermore, EVs obtained from various stem/progenitor cell populations have been tested as cell-free therapy in various preclinical models of cardiovascular diseases and demonstrate unequivocally encouraging benefits. Here we summarize the findings from recent research on the biological functions of EVs in the ischemic heart disease and heart failure, and their potential as novel diagnostic biomarkers and therapeutic opportunities.

Cisplatin versus cisplatin combined with piroxicam in a canine model of human invasive urinary bladder cancer

PURPOSE

More than 12,000 people are expected to die from invasive transitional cell carcinoma (TCC) of the urinary bladder each year in the United States, indicating that more effective therapy is needed. Drugs inhibiting cyclooxygenase (cox) have recently been found to have chemopreventive and antitumor activity and may potentiate the effects of chemotherapy. The purpose of this study was to determine whether cisplatin combined with the cox-inhibitor piroxicam would induce remission more frequently than cisplatin alone in a relevant animal model of human invasive TCC.

METHODS

Pet dogs with naturally occurring, histopathologically confirmed, measurable TCC of the urinary bladder were randomized to receive cisplatin (60 mg/m2 i.v. every 21 days) or cisplatin (same dosage) combined with piroxicam (0.3 mg/kg orally every 24 h). Complete staging was performed prior to and at 6-week intervals during therapy.

RESULTS

After eight dogs had been evaluated in each treatment group, a significant difference in remission rate was noted (Fisher's Exact test, P < 0.004). Tumor responses in the cisplatin/piroxicam group included two complete remissions (CR), four partial remissions (PR), two stable disease (SD), and no progressive disease (PD). Tumor responses to cisplatin alone in eight dogs were no CR, no PR, four SD, and four PD. Six additional dogs were treated with cisplatin/piroxicam, and in total 10 of 14 dogs had remission (two CR, eight PR). Renal toxicity of cisplatin/ piroxicam was frequent and dose limiting.

CONCLUSIONS

Cisplatin/piroxicam induced remission more frequently than cisplatin alone in a canine model of human invasive TCC. Strategies to reduce renal toxicity need to be developed prior to evaluation of cisplatin/piroxicam in humans or general use of this treatment in pet dogs.

Water acquisition and partitioning inDrosophila melanogaster: effects of selection for desiccation-resistance

We examined physiological features related to water balance in five replicate populations of Drosophila melanogaster that have undergone selection for enhanced resistance to desiccation (D populations) and in five replicate control (C) populations. Adult D flies contain 34 % more water than the control flies. We examined two hypotheses for increased water acquisition in the D flies: (i) that they accumulate more water early in development and (ii) that they have a reduced post-eclosion diuretic water loss. We found no evidence of differential water or dry mass acquisition between the C and D populations prior to adulthood. We also found no evidence of differential post-eclosion diuresis, i.e. both C and D groups showed insignificant changes in water volume in the 4 h period immediately after eclosion. In addition, we quantified water content in the intra- and extracellular compartments of the C and D populations and were able to identify the hemolymph as the primary storage site of the ‘extra’ water carried by the desiccation-resistant flies. We estimated that 68 % of the increased water volume observed in the D flies was contained in the hemolymph. Desiccation-resistance was strongly correlated with hemolymph volume and only weakly with intracellular water volume. Survival during desiccation was also strongly related to the carbohydrate content of the D flies. It has been presumed that the D flies accumulate carbohydrate primarily as intracellular glycogen, which would result in a significant increase in intracellular water volume. We found that carbohydrate content was weakly correlated with intracellular water volume and more strongly with hemolymph volume. The carbohydrate pool in the D flies may, therefore, be contained in the extracellular compartment as well as in cells. These results are suggestive of the importance of modifications in hemolymph volume and hemolymph solute concentrations in the evolution of enhanced desiccation-tolerance in populations of Drosophila melanogaster.

Quantitation of circulating DNA in the serum of breast cancer patients by real-time PCR

The purpose of this study was to quantify the level of serum DNA in different groups of primary breast cancer patients and in healthy controls using real-time quantitative PCR in order to determine whether such measurements have diagnostic or prognostic value. A total of 96 serum samples of patients with primary breast cancer before surgery (with positive or negative lymph nodes and with high or low relapse-free survival) as well as 24 healthy controls were analysed. DNA concentrations in the serum of the patients differed significantly from the concentration of serum DNA in the controls (medians were 221 and 63 ng x ml(-1), respectively, P<0.001 M-W test). However, no statistically significant difference was observed between the patient groups (P=0.87, M-W test). The serum DNA levels were elevated independently of the size of primary tumour or lymph node metastases. The overall survival of patients with serum DNA concentrations >221 ng x ml(-1) was better than patients with serum DNA concentration Collapse

Key Words

• serum
• circulating dna
• breast cancer
• real-time pcr

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MESH Headings

• Adult
• Breast Neoplasms/genetics
• Breast Neoplasms/pathology
• Case-Control Studies
• DNA/blood
• Disease-Free Survival
• Female
• Genetic Markers
• Humans
• Lymphatic Metastasis
• Middle Aged
• Polymerase Chain Reaction/methods
• Prognosis
• Retrospective Studies

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Grants Collapse

A critical review of vascular endothelial growth factor (VEGF) analysis in peripheral blood: is the current literature meaningful?

Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor with a key role in many physiological and pathological processes. Investigation into the implications of circulating levels of this cytokine is progressing at an exponential rate. However, there are important inconsistencies between reports ranging from method of sample collection, processing, software manipulation and data interpretation and controversy as to whether plasma, serum or whole blood will provide the best prognostic information. Different techniques of centrifugation and temperature on sample handling and the impact of in vitro collection of blood on subsequent VEGF results have not been fully appreciated. We provide a critical review of the literature, report the results of our further investigations, suggest a uniform protocol for handling blood samples and highlight previously unsuspected problems in data interpretation.

Strategy for dose escalation using 3-dimensional conformal radiation therapy for lung cancer

PURPOSE

Local failure is a major obstacle to the cure of locally advanced non-small-cell lung cancer. 3-Dimensional conformal radiation therapy (3-DCRT) selects optimal treatment parameters to increase dose to tumor and reduce normal tissue dose, potentially permitting dose escalation. There are several ongoing trials of dose escalation using 3-Dimensional conformal radiation therapy for non-small-cell lung cancer. We performed this analysis to determine if data derived from dose volume histograms could be used as the basis for designing the method of dose escalation in these trials.

METHODS AND MATERIALS

Between 1990 and 1993, 31 patients were treated with 3-DCRT and had complete normal tissue dose volume histograms created as part of the planning process. The stage distribution was stage I/II 13%, stage IIIa in 45%, and stage IIIb in 42%. The median radiation dose to gross disease was 70.2 Gy (52.2-72 Gy). Elective mediastinal irradiation (50.4 Gy) was administered to 52% (16/31) of patients.

RESULTS

The major toxicity encountered in this experience was pulmonary. Dose-volume-histogram data were used to analyze the predictors of toxicity and showed a correlation between risk of pulmonary toxicity and indices of dose to lung parenchyma. Grade 3 or higher pulmonary toxicity occurred in 38% (3/8) of pts with >30%of lung volume receiving > or =25 Gy, versus 4% (1/23) of pts. with < or = 30% lung receiving > or = 25 Gy (p=0.04). Grade 3 or higher pulmonary toxicity occurred in 29% (4/14) of patients with a predicted pulmonary normal tissue complication probability of 12% or higher versus 0% (0/17) in patients with a predicted probability of less than 12% (p=0.03). The single fatality occurred in a patient with a calculated pneumonitis probability of 85% and a high percent (49%) lung volume receiving >= 25 GY.

CONCLUSION

This preliminary experience demonstrates a correlation between lung dose-volume-histogram data and the risk of severe pulmonary toxicity. This provides an opportunity to modify the method of radiation dose escalation. Dose-volume-histogram data can allow escalation according to the risk to the lung parenchyma (which is the major organ of concern) rather than escalation according to tumor dose levels. Because of teh major inter-patient variability of intrathoracic tumor bulk and anatomic distribution, this strategy is intuitively appropriate. This approach may facilitate completion of dose escalation studies and identification of maximum tolerable pulmonary dose levels.

The transcription factor DEC1 (stra13, SHARP2) is associated with the hypoxic response and high tumour grade in human breast cancers

DEC1, also known as SHARP-2 or Stra13, plays important roles in embryonic development, proliferation, apoptosis and cell differentiation in the mouse. DEC1 was recently identified as hypoxically induced in cDNA microarray studies of the human renal carcinoma cell line RCC4, to be regulated through hypoxia-inducible factor (HIF)-1α and via HIF-1α, able to block adipocyte differentiation. Nevertheless, its distribution and role in hypoxia and differentiation in human breast cancer are unknown. We therefore examined the pattern and level of expression of DEC1 using immunohistochemistry in whole tissue sections in normal, in situ and invasive breast carcinomas, and correlated the level of expression of DEC1 and clinicopathological factors and hypoxic tumour markers in 253 invasive carcinomas on tissue microarrays. We observed an increase in DEC1 expression during progression from normal to in situ and invasive carcinoma. Expression was not restricted to the tumour cell element but was also observed in endothelial, fibroblasts and inflammatory cells. There was a significant positive correlation between DEC1 and tumour grade (P=0.01), HIF-1α (P=0.04) and the hypoxically regulated gene angiogenin (P<0.0001), but no significant associations were observed with patient age (P=0.15), lymph node status (P=0.8), tumour size (P=0.3), oestrogen receptor (P=0.45), epidermal growth factor receptor (P=0.27) or Chalkley vessel count (P=0.45). There was no difference in relapse-free (P=0.84) or overall (P=0.78) survival. These findings suggest that DEC1 plays an important role in the progression to invasive breast cancer and that it may provide a mechanism by which hypoxia blocks tumour differentiation, and may contribute to a more aggressive phenotype. Reversing this phenotype may alter the biological behaviour of individual tumours.

Nav1.7-related small fiber neuropathy: impaired slow-inactivation and DRG neuron hyperexcitability

OBJECTIVES

Although small fiber neuropathy (SFN) often occurs without apparent cause, the molecular etiology of idiopathic SFN (I-SFN) has remained enigmatic. Sodium channel Na(v)1.7 is preferentially expressed within dorsal root ganglion (DRG) and sympathetic ganglion neurons and their small-diameter peripheral axons. We recently reported the presence of Na(v)1.7 variants that produce gain-of-function changes in channel properties in 28% of patients with painful I-SFN and demonstrated impaired slow-inactivation in one of these mutations after expression within HEK293 cells. Here we show that the I739V Na(v)1.7 variant in a patient with biopsy-confirmed I-SFN impairs slow-inactivation within DRG neurons and increases their excitability.

METHODS

A patient with SFN symptoms including pain, and no identifiable underlying cause, was evaluated by skin biopsy, quantitative sensory testing, nerve conduction studies, screening of genomic DNA for variants in SCN9A, and functional analysis.

RESULTS

Voltage-clamp analysis following expression within DRG neurons revealed that the Na(v)1.7/I739V substitution impairs slow-inactivation, depolarizing the midpoint (V(1/2)) by 5.6 mV, and increasing the noninactivating component at 10 mV from 16.5% to 22.2%. Expression of I739V channels within DRG neurons rendered these cells hyperexcitable, reducing current threshold and increasing the frequency of firing evoked by graded suprathreshold stimuli.

CONCLUSIONS

These observations provide support, from a patient with biopsy-confirmed SFN, for the suggestion that functional variants of Na(v)1.7 that impair slow-inactivation can produce DRG neuron hyperexcitability that contributes to pain in SFN. Na(v)1.7 channelopathy-associated SFN should be considered in the differential diagnosis of cases of SFN in which no other cause is found.