Regulation of the COPII secretory machinery via focal adhesions and extracellular matrix signaling

Proteins that enter the secretory pathway are transported from their place of synthesis in the endoplasmic reticulum to the Golgi complex by COPII-coated carriers. The networks of proteins that regulate these components in response to extracellular cues have remained largely elusive. Using high-throughput microscopy, we comprehensively screened 378 cytoskeleton-associated and related proteins for their functional interaction with the coat protein complex II (COPII) components SEC23A and SEC23B. Among these, we identified a group of proteins associated with focal adhesions (FERMT2, MACF1, MAPK8IP2, NGEF, PIK3CA, and ROCK1) that led to the downregulation of SEC23A when depleted by siRNA. Changes in focal adhesions induced by plating cells on ECM also led to the downregulation of SEC23A and decreases in VSVG transport from ER to Golgi. Both the expression of SEC23A and the transport defect could be rescued by treatment with a focal adhesion kinase inhibitor. Altogether, our results identify a network of cytoskeleton-associated proteins connecting focal adhesions and ECM-related signaling with the gene expression of the COPII secretory machinery and trafficking.

Neuropathic pain caused by miswiring and abnormal end organ targeting

Nerve injury leads to chronic pain and exaggerated sensitivity to gentle touch (allodynia) as well as a loss of sensation in the areas in which injured and non-injured nerves come together^1–3. The mechanisms that disambiguate these mixed and paradoxical symptoms are unknown. Here we longitudinally and non-invasively imaged genetically labelled populations of fibres that sense noxious stimuli (nociceptors) and gentle touch (low-threshold afferents) peripherally in the skin for longer than 10 months after nerve injury, while simultaneously tracking pain-related behaviour in the same mice. Fully denervated areas of skin initially lost sensation, gradually recovered normal sensitivity and developed marked allodynia and aversion to gentle touch several months after injury. This reinnervation-induced neuropathic pain involved nociceptors that sprouted into denervated territories precisely reproducing the initial pattern of innervation, were guided by blood vessels and showed irregular terminal connectivity in the skin and lowered activation thresholds mimicking low-threshold afferents. By contrast, low-threshold afferents—which normally mediate touch sensation as well as allodynia in intact nerve territories after injury^4–7—did not reinnervate, leading to an aberrant innervation of tactile end organs such as Meissner corpuscles with nociceptors alone. Genetic ablation of nociceptors fully abrogated reinnervation allodynia. Our results thus reveal the emergence of a form of chronic neuropathic pain that is driven by structural plasticity, abnormal terminal connectivity and malfunction of nociceptors during reinnervation, and provide a mechanistic framework for the paradoxical sensory manifestations that are observed clinically and can impose a heavy burden on patients.

Longitudinal imaging of nerve fibres in mice reveals that reinnervation after nerve injury can lead to neuropathic pain, which is mediated through aberrant patterns of reinnervation in denervated areas by nociceptors.

Room temperature laser power standard using a microfabricated, electrical substitution bolometer

The design and performance of a room temperature electrical substitution radiometer for use as an absolute standard for measuring continuous-wave laser power over a wide range of wavelengths, beam diameters, and powers are described. The standard achieves an accuracy of 0.46% (k = 2) for powers from 10 mW to 100 mW and 0.83% (k = 2) for powers from 1 mW to 10 mW and can accommodate laser beam diameters (1/e²) up to 11 mm and wavelengths from 300 nm to 2 μm. At low power levels, the uncertainty is dominated by sensitivity to fluctuations in the thermal environment. The core of the instrument is a planar, silicon microfabricated bolometer with vertically aligned carbon nanotube absorbers, commercial surface mount thermistors, and an integrated heater. Where possible, commercial electronics and components were used. The performance was validated by comparing it to a National Institute of Standards and Technology primary standard through a transfer standard silicon trap detector and by comparing it to the legacy "C-series" standards in operation at the U.S. Air Force Metrology and Calibration Division (AFMETCAL).

In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges

The spike protein (S) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required for cell entry and is the primary focus for vaccine development. In this study, we combined cryo-electron tomography, subtomogram averaging, and molecular dynamics simulations to structurally analyze S in situ. Compared with the recombinant S, the viral S was more heavily glycosylated and occurred mostly in the closed prefusion conformation. We show that the stalk domain of S contains three hinges, giving the head unexpected orientational freedom. We propose that the hinges allow S to scan the host cell surface, shielded from antibodies by an extensive glycan coat. The structure of native S contributes to our understanding of SARS-CoV-2 infection and potentially to the development of safe vaccines.

In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges

The spike protein (S) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required for cell entry and is the primary focus for vaccine development. In this study, we combined cryo-electron tomography, subtomogram averaging, and molecular dynamics simulations to structurally analyze S in situ. Compared with the recombinant S, the viral S was more heavily glycosylated and occurred mostly in the closed prefusion conformation. We show that the stalk domain of S contains three hinges, giving the head unexpected orientational freedom. We propose that the hinges allow S to scan the host cell surface, shielded from antibodies by an extensive glycan coat. The structure of native S contributes to our understanding of SARS-CoV-2 infection and potentially to the development of safe vaccines.

Glycogen accumulation, central carbon metabolism, and aging of hematopoietic stem and progenitor cells

Inspired by recent proteomic data demonstrating the upregulation of carbon and glycogen metabolism in aging human hematopoietic stem and progenitor cells (HPCs, CD34+ cells), this report addresses whether this is caused by elevated glycolysis of the HPCs on a per cell basis, or by a subpopulation that has become more glycolytic. The average glycogen content in individual CD34+ cells from older subjects (> 50 years) was 3.5 times higher and more heterogeneous compared to younger subjects (< 35 years). Representative glycolytic enzyme activities in HPCs confirmed a significant increase in glycolysis in older subjects. The HPCs from older subjects can be fractionated into three distinct subsets with high, intermediate, and low glucose uptake (GU) capacity, while the subset with a high GU capacity could scarcely be detected in younger subjects. Thus, we conclude that upregulated glycolysis in aging HPCs is caused by the expansion of a more glycolytic HPC subset. Since single-cell RNA analysis has also demonstrated that this subpopulation is linked to myeloid differentiation and increased proliferation, isolation and mechanistic characterization of this subpopulation can be utilized to elucidate specific targets for therapeutic interventions to restore the lineage balance of aging HPCs.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition)

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.

Evaluation of Anatomical and Functional Hip Joint Center Methods: The Effects of Activity Type, Gender, and Proximal Reference Segment

Accurate hip joint center (HJC) location is critical when studying hip joint biomechanics. The HJC is often determined from anatomical methods, but functional methods are becoming increasingly popular. Several studies have examined these methods using simulations and in vivo gait data, but none has studied high-range of motion activities, such a chair rise, nor has HJC prediction been compared between males and females. Furthermore, anterior superior iliac spine (ASIS) marker visibility during chair rise can be problematic, requiring a sacral cluster as an alternative proximal segment; but functional HJC has not been explored using this approach. For this study, the quality of HJC measurement was based on the joint gap error (JGE), which is the difference in global HJC between proximal and distal reference segments. The aims of the present study were to: (1) determine if JGE varies between pelvic and sacral referenced HJC for functional and anatomical methods, (2) investigate which functional calibration motion results in the lowest JGE and if the JGE varies depending on movement type (gait versus chair rise) and gender, and (3) assess whether the functional HJC calibration results in lower JGE than commonly used anatomical approaches and if it varies with movement type and gender. Data were collected on 39 healthy adults (19 males and 20 females) aged 14–50 yr old. Participants performed four hip “calibration” tests (arc, cross, star, and star-arc), as well as gait and chair rise (activities of daily living (ADL)). Two common anatomical methods were used to estimate HJC and were compared to HJC computed using a published functional method with the calibration motions above, when using pelvis or sacral cluster as the proximal reference. For ADL trials, functional methods resulted in lower JGE (12–19 mm) compared to anatomical methods (13–34 mm). It was also found that women had significantly higher JGE compared to men and JGE was significantly higher for chair rise compared to gait, across all methods. JGE for sacrum referenced HJC was consistently higher than for the pelvis, but only by 2.5 mm. The results indicate that dynamic hip range of movement and gender are significant factors in HJC quality. The findings also suggest that a rigid sacral cluster for HJC estimation is an acceptable alternative for relying solely on traditional pelvis markers.

A study comparing insulin lispro mix 25 with glargine plus lispro therapy in patients with Type 2 diabetes who have inadequate glycaemic control on oral anti-hyperglycaemic medication: results of the PARADIGM study

AIMS

To test the hypothesis that initiation and intensification with 25% insulin lispro, 75% insulin lispro protamine suspension (LM25), is non-inferior to initiation and intensification with glargine + insulin lispro therapy on change from baseline in HbA(1c).

METHODS

In this randomized, non-inferiority (margin of 0.4%), parallel, prospective, multi-country, 48-week, open-label study, patients (n = 426) with Type 2 diabetes inadequately controlled with oral anti-hyperglycaemic medications were assigned to either initiating therapy with one daily LM25 injection, progressing up to three daily injections (full analysis set n = 211; per protocol set n = 177) or initiating therapy with one daily glargine injection and progressing up to three daily insulin lispro injections (full analysis set n = 212; per protocol set n = 184).

RESULTS

LM25 therapy was found to be non-inferior to glargine + insulin lispro therapy by study end (upper limit of 95% CI < 0.4), with a least-squares mean difference (95% CI) in HbA(1c) (LM25 minus glargine + insulin lispro) of -0.4 mmol/mol (95% CI -2.7 to 1.9); -0.04% (95% CI -0.25 to 0.17). No statistically significant differences between treatment groups were found in the percentage of patients achieving HbA(1c) targets or postprandial blood glucose levels. The increase in insulin dose, number of injections and weight change during the course of the study were similar in both groups. Patients in both groups experienced similar hypoglycaemia rates and safety profile.

CONCLUSIONS

For patients with Type 2 diabetes inadequately controlled with oral anti-hyperglycaemic medications, glycaemic control when initiating and intensifying with LM25 therapy was found to be non-inferior to treatment with glargine + insulin lispro therapy.

An exploratory analysis of factors associated with weight change in a 16-week trial of oral vs. orally disintegrating olanzapine: the PLATYPUS study

BACKGROUND

We conducted exploratory analyses of the data from a multinational, randomised study to identify factors associated with weight change after 16 weeks of treatment with standard olanzapine tablets (SOT) or sublingual orally disintegrating olanzapine (ODO).

METHODS

One hundred and forty nine outpatients who gained weight during prior SOT therapy were enrolled into the study and treated with ODO (N = 84) or SOT (N = 65). Exploratory analyses were conducted with the subset of compliant patients (ODO: n = 60; SOT: n = 47).

RESULTS

The decrease in the rate of weight gain at the end of study therapy (change from baseline) was greater in the ODO group than the SOT group (-0.59 kg/week vs. -0.38 kg/week, p = 0.0246). Age was negatively associated with weight change (p = 0.0203) in both treatment groups combined: patients gained 0.7 kg less for every 10 years of age. The least squares mean weight gain was lower with ODO than SOT in male patients (0.35 kg vs. 3.04 kg, p = 0.061), but not female patients and in American patients (0.55 kg vs. 6.21 kg, p < 0.0001), but not Canadian or Mexican patients.

CONCLUSIONS

Although not conclusive, these data suggest that ODO may be a reasonable treatment option for some patients who gain weight with SOT. Further research is required to confirm these findings.

The Triple Threat of Recurrence after Breast Conserving Therapy: Race, Receptor Status and Age

PurposeThe purpose of this study is to evaluate the impact of race, receptor status, and age on recurrence in patients undergoing breast conserving therapy (BCT).MethodsThe study population consisted of 510 primary invasive female breast cancer patients (excluding Stage IV), who resided in Fulton-Dekalb counties, in Atlanta, GA. These patients were diagnosed in 2003-2004 and treated within the Emory University Affiliated Hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.5 and 4.4 years for recurrence and survival, respectively. Breast tumors were categorized as either triple negative (TN), which were estrogen, progesterone, and Her2-neu receptor negative tumors, versus (vs) non-TN, all other possible iterations. Women were evaluated for recurrence and death by TN status, race (African American (AA) vs Caucasian (C)), age, grade, tumor size, nodal status, socioeconomic status (SES), and receipt of chemotherapy. Both recurrence and survival were evaluated using chi-square, fisher exact, and cox regression analyses, p ≤ 0.05 significance.ResultsOf the 510 women, 193 received BCT. Of the 193, 92% completed radiation therapy and 45% received chemotherapy. Of the 184 women with known recurrence status, 11 recurred locally, 11 distantly, and none regionally. Compared to patients with non-TN tumors, TN patients had significantly higher local (13% vs 5%) and distant (16% vs 4%) recurrence rates. AA women had non-significant higher local recurrence than C women (7% vs 4%) and a higher distant recurrence rate (8% vs 3%). Finally, compared to women ≥50 years old, women age &lt;50 had a significantly higher local and distant recurrence rates, (13% vs 4%) and (9% vs 5%) respectively.Unadjusted hazard ratios (HR) and 95% confidence intervals (CI) for any recurrence were calculated: TN status (HR=2.8, 95%CI 1.2-6.5), AA race (HR=2.3, 95% CI 0.9-5.8), age &lt;50 years (HR= 2.3, 95%CI 1.0-5.1), grade 2/3 vs 1 (HR=2.3, 95%CI 1.0-5.1), and chemotherapy receipt (HR=3.0, 95%CI 1.2-7.4). Factors that were highly non-statistically significant included stage, tumor size, nodal status, and SES.In a multivariate model including receptor status, race, and age results were similar (HR = 2.5, 2.1, and 2.1 respectively). When tumor size, nodal status, grade, SES, and chemotherapy status were included in the previous model, only AA race independently predicted recurrence (HR=3.4, 95%CI 1.1-11.1), while TN status demonstrated a trend (HR=1.9, 95%CI 0.8-5.7).In survival analyses, neither TN status, AA race, nor age &lt;50 years predicted outcome in any of the models described above. However, TN status did show a trend for significance (HR=2.6, 95%CI 0.8-9.0).ConclusionWe observed that there was a significant increase in local and distant metastatic recurrence rates after BCT among patients diagnosed with TN breast cancers, AA women, and women &lt;50 years old. In contrast, we did not observe differences in survival, with the exception of TN breast cancers. This study suggests that among women who receive BCT, current standard radiation and systemic therapies may not be adequate in preventing recurrence among women with TN breast cancers, of AA race, or younger age.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6045.

The Effect of Radiotherapy on Local Regional Recurrence among Patients with Pathologic Complete Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Background: Radiotherapy has been shown to reduce local recurrence rates of breast cancer after treatment with surgery and adjuvant chemotherapy. Indications for postmastectomy radiation have historically been based on pathology, but indications for radiation in the setting of pathologic complete response (pCR) to neoadjuvant chemotherapy are not well defined. The aim of this study was to evaluate the rates of local regional recurrence (LRR) among patients with pCR to neoadjuvant chemotherapy followed by surgery with or without radiation (XRT).Patients and Methods: The case histories of 337 patients with locally advanced breast cancer treated with neoadjuvant chemotherapy, surgery with or without radiation from October 1997 to December 2006 were analyzed. Median age at diagnosis was 50.6 years (range: 25-84). The clinical stage at diagnosis was I in 3 (1%), IIA in 105 (31%), IIB in 94 (28%), and III in 135 (40%) patients. All patients received preoperative systemic therapy with a doxorubicin-based regimen (92%) or a single-agent taxane regimen (7%) or CMF (1%). A total of 272 patients received radiation following surgery and 65 did not receive any radiation. Median follow-up time was 40 months among all patients. The Kaplan-Meier method and log rank test were used to evaluate LRR rates and overall survival among both groups.Results: Patients treated with neoadjuvant chemotherapy followed by surgery and XRT had a lower incidence of LRR at 3 years with 24 cases of local recurrence among 272 patients who received XRT compared with 12 cases of local recurrence among the 65 patients who did not receive XRT (8.9% v 18.5%, P=0.02). Radiation also reduced local regional recurrence at 3 years among a subset of patients with clinical stage T2N1 disease (4.9% v 28.6%, P=0.03). There was no difference in overall survival or disease free survival among patients who received XRT compared to patients who did not receive XRT. There were 62 (18%) patients who achieved a pCR to neoadjuvant chemotherapy. Among patients with a pathologic complete response, radiation appeared to reduce the risk of LRR compared to patients who did not receive XRT (7.4% v 25%, P=0.17).Conclusion: Radiotherapy significantly reduced local regional recurrence rate among patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and surgery. Of particular interest, patients who achieve a pathologic complete response to neoadjuvant chemotherapy still had high LRR rates and may benefit from radiotherapy by lowering the risk of local regional recurrence. Further studies on the significance of LRR and overall survival among these patients are needed.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4114.

A randomized controlled trial of the effect of sublingual orally disintegrating olanzapine versus oral olanzapine on body mass index: the PLATYPUS Study

BACKGROUND

Patients with schizophrenia and bipolar disorder have frequently reported weight gain during olanzapine treatment. Previous studies have observed a decrease in weight gain, or weight loss, in patients switching from standard olanzapine tablets (SOT) to orally disintegrating olanzapine (ODO) tablets. The primary objective of this study was to investigate the change in body mass index (BMI) in patients who had previously gained weight with SOT and continued with this therapy during the study period, compared with those patients who switched to ODO during the study period.

METHODS

This was a 16-week, multicentre, randomized, double-blind, double-dummy, study of outpatients diagnosed with schizophrenia, schizoaffective disorder, related psychotic disorder or bipolar disorder, who were taking 5-20 mg SOT daily. Patients continued treatment with 5-20 mg olanzapine in a flexible single daily dose, and were randomized to either receive sublingual ODO plus an oral placebo, or sublingual placebo plus SOT.

RESULTS

No statistically significant between group differences in mean change from baseline in BMI, weight or waist circumference were observed. Analysis of change in body weight from baseline, by pre-specified category (no change, loss of >or=1.5 kg, gain of >or=1.5 kg), revealed a significant difference between groups, favoring ODO patients, who also experienced a significant reduction in subjective appetite and better treatment compliance, compared to patients in the SOT group.

CONCLUSIONS

In this study, patients treated with ODO experienced a similar mean change in BMI and weight from baseline, to those patients treated with SOT.

Triple negative breast cancer confers higher recurrence rates after breast conserving therapy

Abstract #5127

Purpose&#x2028; There has been a recent surge of information regarding the treatment outcomes for women with estrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative breast cancer; known as the triple negative (TN) subtype. The purpose of this study is to evaluate the impact of these receptor expressions on local, regional and distant recurrences, and overall survival (OS) in patients undergoing breast conserving therapy (BCT).&#x2028; Patients and Methods&#x2028; The study population included 475 primary invasive female breast cancer patients (excluding Stage IV); who were residents of Fulton-Dekalb counties in Atlanta when diagnosed in 2003-2004 and treated within the Emory University affiliated hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.4 years. The endpoints of the study were local, regional and distant recurrences, and OS. Tumors were subgrouped as: ER-/PR-/HER2- (TN), ER+/PR+/HER2-, ER+/PR+/HER2+, ER+/PR+/HER2-. Chi-square and Fisher exact tests were employed.&#x2028; Results&#x2028; For the entire population, median age was 58 years. TN tumors accounted for 17% of the cases. Of the TN patients, 78% were African-American (p&lt;0.01) and 40% had BCT. The majority of TN tumors were high grade (71%), p&lt; 0.01. Total recurrence was 33% among the TN patients vs. 14% in the combined non-TN patient group, p&lt; 0.01. Death occurred among 29% of TN vs. 14% of non-TN, p&lt; 0.01.&#x2028; For the patients that were treated with BCT, 94% of TN patients completed their adjuvant radiation therapy and 73% received chemotherapy. Of those receiving BCT, recurrence was 28% for TN patients and 6% for non-TN patients (p&lt;0.01). Local recurrence was 9% and 4% for TN and non-TN patients, respectively and distant metastatic rate was 16% versus 2% respectively (p&lt; 0.01). There were no regional recurrences in the BCT group. Time to recurrence, OS, time to death, and breast cancer specific death did not differ between the two groups.&#x2028; Conclusion&#x2028; A significant increase in local recurrence and distant metastatic rates were observed after BCT among patients diagnosed with TN breast cancers; however there was not a significant short-term survival difference between the TN and non-TN receptor groups. The complexity of this patient population within the conventional treatment algorithm warrants further investigation to reduce local and distant recurrences.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5127.

Preventive chemotherapy. Where has it got us? Where to go next?

The World Health Organization estimates that a third of the world's population is infected with Mycobacterium tuberculosis. Every second, one person becomes newly infected with tuberculosis (TB). In the past two decades, the spread of human immunodeficiency virus infection, worsening poverty and deteriorating health services have resulted in a steady increase in the overall incidence of TB globally. With treatment of latent TB infection (LTBI), the number of infected persons who develop active TB can be significantly diminished. Prevention through treatment of LTBI should therefore be an integral part of the control of TB. Although only a minority of those with LTBI will develop active disease, the risk varies substantially according to the time since infection and medical risk factors. If persons at low risk for TB are selected for preventive chemotherapy, the individual and public health benefits are low, and a large number will have to be treated to prevent a single active case. It is therefore important to identify and treat patients who are at high risk of disease. Tools for rapid and reliable identification of persons with LTBI who are most likely to progress to active disease are urgently needed, as this will permit rational use of preventive treatment by restricting treatment to those patients with the most favourable risk/benefit ratio. The major challenges are efficient identification of those at highest risk of developing disease and ensuring treatment completion with a non-toxic regimen. If these can be overcome, preventive treatment holds the promise to substantially assist in the achievement of global control of TB.

[Idiopathic hypereosinophilic syndrome: toward a new molecular-targeted therapy and a new cytomorphological and molecular definition]

Idiopathic hypereosinophilic syndrome is characterised by chronic hypereosinophilia leading to tissue damage, and after exclusion of reactive eosinophilia. Until recently no specific or efficient therapeutic was available. In 2003, a recurrent interstitial deletion 4q12 leading to the fusion of the FIP1L1 and PDGFRA genes was detected in hypereosinophilic syndromes. The resulting protein has constitutive tyrosine kinase activity which explains clinical and cytological remission of hypereosinophilic syndrome after treatment by a specific tyrosine kinase inhibitor, imatinib mesylate or Glivec, usually used in chronic myeloid leukaemia. Here we report a patient with hypereosinophilic syndrome associated to peculiar morphology of neutrophilic series and the 4q12 deletion. He presented clinical and haematological remission since the introduction of imatinib mesylate therapy.

A comparison of the fixed combination of latanoprost and timolol with the unfixed combination of brimonidine and timolol in patients with elevated intraocular pressure. A six month, evaluator masked, multicentre study in Europe

PURPOSE

To compare the intraocular pressure (IOP) reducing effect and safety of fixed combination (FC) latanoprost/timolol with unfixed combination (UFC) brimonidine/timolol in patients with increased IOP.

METHODS

In this 6 month, randomised, evaluator masked, parallel group European study, patients with glaucoma or ocular hypertension and IOP > or =21 mm Hg on monotherapy or >16 mm Hg on dual therapy received either FC latanoprost/timolol at 8:00AM or UFC brimonidine/timolol at 8:00AM and 8:00PM. The primary outcome was the difference from baseline to month 6 in mean diurnal IOP reduction.

RESULTS

325 of 334 randomised patients were included in intent to treat analyses (FC latanoprost/timolol, 163; UFC brimonidine/timolol, 162). Baseline diurnal IOP levels were similar: FC latanoprost/timolol, 26.4 (SD 2.7) mm Hg; UFC brimonidine/timolol, 26.5 (SD 2.8) mm Hg (p = 0.851). At month 6, levels were 16.9 (SD 2.8) mm Hg in FC latanoprost/timolol patients and 18.2 (SD 3.1) mm Hg in UFC brimonidine/timolol patients (p<0.001). No adverse events were reported by 76.4% and 75.5% of patients receiving FC latanoprost/timolol versus UFC brimonidine/timolol, respectively. Larger proportions of brimonidine/timolol treated patients reported study medication related adverse events (18.6% v 7.3%) and discontinued study participation because of this (10.8% v 1.8%).

CONCLUSION

Fixed combination latanoprost/timolol administered once daily is both more effective and better tolerated than twice daily dosing with UFC brimonidine/timolol.

A kinase-independent function of Ask1 in caspase-independent cell death

Ask1 (apoptosis signal-regulating kinase 1) is activated as a consequence of cell exposure to a variety of stresses and can then initiate apoptosis. A known pathway of apoptosis downstream of Ask1 involves the activation of the stress-activated protein kinases, the release of cytochrome c from mitochondria, the activation of caspases, and the fragmentation of nuclei. Here, we characterized a novel mechanism of Ask1-mediated cell killing that is triggered by the interaction with Daxx. Co-transfection of Ask1 and Daxx induced a caspase-independent cell-death process characterized at the morphological level by distinctive crumpled nuclei easily distinguishable from the condensed and fragmented nuclei seen during classical caspase-dependent apoptosis. The kinase activity of Ask1 was not involved in this process, because mutants lacking kinase activity were as efficient as wild type Ask1 in mediating Daxx-induced cell death. Ask1N, a deletant that lacks the C-terminal half including the kinase domain of Ask1, was constitutively active in producing crumpled nuclei. In contrast, Ask1DeltaN, the reciprocal deletant that possesses constitutive kinase activity, produced fragmented nuclei typical of caspase-dependent death processes. We conclude that in addition to a caspase-dependent pro-apoptotic function that depends on its kinase activity, Ask1 possesses a caspase-independent killing function that is independent on its kinase activity and is activable by interaction with Daxx. In the physiological situation, such an activity is induced as a consequence of the translocation of Daxx from the nucleus to the cytoplasm, a condition that occurs following activation of the death receptor Fas.

Older adults' acceptance of psychological and pharmacological treatments for depression

Two hundred participants aged 65 and older recruited from 4 different family medicine clinics rated the acceptability of 3 different treatments for geriatric depression: (a) cognitive therapy (CT), (b) cognitive bibliotherapy (CB), and (c) antidepressant medication (AM). Results showed that the acceptability of the treatments is a function of the severity of the symptoms of the depressed patient to whom they would be applied. CT and CB were rated as more acceptable than AM when patient symptoms were mild to moderate. However, CT was more acceptable than both CB and AM when patient symptoms were described as severe. Acceptability ratings were not related to the raters' own depressive symptoms. The practical implications of these results are discussed.

Higher than normal plasma interleukin-6 concentrations in cancer patients with depression: preliminary findings

OBJECTIVE

This study investigated whether cancer patients with and without major depression exhibit immune system abnormalities similar to those reported in medically healthy, depressed subjects without cancer.

METHOD

The study subjects consisted of patients diagnosed with pancreatic, esophageal, or breast cancer. Other groups consisted of subjects with major depression (without cancer) and healthy comparison subjects. Subjects' diagnoses were made with the Structured Clinical Interview for DSM-III-R. Severity of depression was measured with the Hamilton Depression Rating Scale. Plasma concentrations of interleukin-6 (IL-6) and postdexamethasone cortisol were measured.

RESULTS

Cancer patients with depression had markedly higher plasma concentrations of IL-6 than healthy comparison subjects and cancer patients without depression. Although significant correlations were found between Hamilton depression scale scores and plasma concentrations of postdexamethasone cortisol, no significant correlations were found between plasma IL-6 and postdexamethasone cortisol concentrations.

CONCLUSIONS

Higher than normal plasma IL-6 concentrations were associated with a diagnosis of major depression in cancer patients. IL-6 may contribute to sickness behavior that has overlapping symptoms with major depression.

Involvement of p38 in apoptosis-associated membrane blebbing and nuclear condensation

The stress-activated protein kinase p38 is often induced by cytotoxic agents, but its contribution to cell death is ill defined. In Rat-1 cells, we found a strong correlation between activation of p38 and induction of c-Myc-dependent apoptosis. In cells with deregulated c-Myc expression but not in control cells, cis-diamminedichloroplatinum induced p38 activity and typical features of apoptosis, including internucleosomal DNA degradation, induction of caspase activities, and both nuclear (nuclear condensation and fragmentation) and extranuclear (cell blebbing) morphological alterations. The pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone did not block p38 activation and the p38 inhibitor SB203580 had no detectable effect on the activation of caspases or the in vivo cleavage of several caspase substrates, suggesting that p38 and caspase activation can contribute distinct features of apoptosis. Accordingly, we found that cell blebbing was independent of caspase activity and, rather, depended on p38-sensitive changes in microfilament dynamics likely mediated by heat shock protein 27 phosphorylation. Furthermore, p38 activity contributed to both caspase-dependent and caspase-independent nuclear condensation and fragmentation, suggesting a role in an early event triggering both mechanisms of apoptosis or sensitizing the cells to the action of both types of apoptosis executioners. Inhibiting p38 also resulted in a significant enhancement in cell survival estimated by colony formation. This capacity to modulate the sensitivity to apoptosis in cells with deregulated c-Myc expression suggests an important role for p38 in tumor cell killing by chemotherapeutic agents.

A novel form of transcriptional silencing by Sum1-1 requires Hst1 and the origin recognition complex

In the yeast Saccharomyces cerevisiae, a and alpha mating-type information is stored in transcriptionally silenced cassettes called HML and HMR. Silencing of these loci, maintained by the formation of a specialized type of heterochromatin, requires trans-acting proteins and cis-acting elements. Proteins required for silencing include the Sir2 NAD(+)-dependent deacetylase, Sir3, and Sir4. Factors that bind to the cis elements at HMR and HML and that are important for silencing include the origin recognition complex (ORC). Mutations of any of these Sir proteins or combinations of cis elements result in loss of silencing. SUM1-1 was previously identified as a dominant mutation that restores silencing to HMR in the absence of either the Sir proteins or some of the cis elements. We have investigated the novel mechanism whereby Sum1-1 causes Sir-independent silencing at HMR and present the following findings: Sum1-1 requires the Sir2 homolog, Hst1, for silencing and most probably requires the NAD(+)-dependent deacetylase activity of this protein. Sum1-1 interacts strongly with ORC, and this strong interaction is dependent on HMR DNA. Furthermore, ORC is required for Sum1-1-mediated silencing at HMR. These observations lead to a model for Sum1-1 silencing of HMR in which Sum1-1 is recruited to HMR by binding to ORC. Sum1-1, in turn, recruits Hst1. Hst1 then deacetylates histones or other chromatin-associated proteins to cause chromatin condensation and transcriptional silencing.

Crystal structure of a SIR2 homolog-NAD complex

The SIR2 protein family comprises a novel class of nicotinamide-adenine dinucleotide (NAD)-dependent protein deacetylases that function in transcriptional silencing, DNA repair, and life-span extension in Saccharomyces cerevisiae. Two crystal structures of a SIR2 homolog from Archaeoglobus fulgidus complexed with NAD have been determined at 2.1 A and 2.4 A resolutions. The structures reveal that the protein consists of a large domain having a Rossmann fold and a small domain containing a three-stranded zinc ribbon motif. NAD is bound in a pocket between the two domains. A distinct mode of NAD binding and an unusual configuration of the zinc ribbon motif are observed. The structures also provide important insights into the catalytic mechanism of NAD-dependent protein deacetylation by this family of enzymes.

The interaction of HSP27 with Daxx identifies a potential regulatory role of HSP27 in Fas-induced apoptosis

The heat shock protein HSP27 protects cells against a wide variety of toxic treatments and blocks apoptosis induced by exposures to anticancer drugs and activation of the death receptor Fas. The molecular mechanisms of protection are unknown but appear to be regulated by phosphorylation of HSP27. Two apoptotic pathways can be activated downstream of Fas. The Fas-adaptor FADD mediates a caspase-dependent pathway. Fas also activates a caspase-independent pathway which correlates with Fas-induced translocation of Daxx from the nucleus to the cytoplasm and involves the interaction of Daxx with Fas and Ask1. We found that phosphorylated dimers of HSP27 interact with Daxx, preventing its interaction with Ask1 and Fas and blocking Daxx-mediated apoptosis. Expression of HSP27 also prevents the translocation of Daxx from the nucleus to the cytoplasm which is induced upon expression of Ask1 or stimulation of Fas. The observations reveal a new level of regulation of the Fas pathway. Whereas the FADD axis can be modulated by expression of FLIP, a natural inhibitor of FADD, our results show that HSP27 can accomplish a similar function for the Daxx axis.

Markers of neck failure in oral cavity and oropharyngeal carcinomas treated with radiotherapy

BACKGROUND

Neck management after radiotherapy remains controversial. It is not clear which patients may benefit from postradiotherapy neck dissection. Biologic markers may be useful in this setting.

METHOD

This study includes 81 patients with oral cavity and oropharyngeal carcinomas. The primary tumor had been treated with radical radiotherapy. Immunohistochemical staining to p53, ki-67, NEU, HSP-27, and GST has been performed.

RESULTS

There were 50 T1-2 and 31 T3-4 patients, as well as 36 NO and 45 N1-3. A total of 25 nodal failures was observed. With expressed HSP2, 23% of patients had neck failure compared with 51% when HSP-27 was absent (p = .02). With NEU overexpression, nodal control decreased from 72% to 34% (p = .008). In a Cox model, NEU (p = .01) and HSP-27 (p = .05) were associated with neck failure.

CONCLUSIONS

HSP-27 and NEU expression may play a role in predicting nodal failure. This should be confirmed in a larger, prospective study.

Isolation and quantitation of zeins in waxy and amylose-extender and wild flint and dent maize endosperm using a new solvent sequence for protein extraction

Protein distribution in endosperm of maize grains differing by their texture, flint or dent, and by their genotype, wild or waxy or amylose-extender, was examined by the successive use of 0.5 M NaCl, 0.5 M NaCl plus 0.6% 2-mercaptoethanol (2ME) at neutral and then alkaline pH, and 55% 2-propanol plus 0.6% 2ME as extractants. Proteins extracted in the presence of 2ME were characterized by their size polymorphism and amino acid composition. Proteins isolated with NaCl plus 2ME at neutral pH corresponded with a mixture of gamma-zein (27 kDa) and glutelin-like proteins. Proteins isolated with NaCl plus 2ME at pH 10 were a mixture of gamma-zeins (27 and 16 kDa) and beta-zeins (14 kDa). Alcohol-soluble proteins consisted of alpha-, beta-, and delta-zeins, alpha subunits being predominant. Zein quantitation was improved by weighing the nitrogen percentage of extracts by their zein content, as estimated from the data on amino acid composition. The data reported by Wolf et al. (Cereal Chem. 1975, 52, 765) were integrated to the results of this work to suggest the occurrence of an inverse correlation between amylose in starch and zeins in proteins.

Silent information regulator 2 family of NAD- dependent histone/protein deacetylases generates a unique product, 1-O-acetyl-ADP-ribose

Conflicting reports have suggested that the silent information regulator 2 (SIR2) protein family employs NAD(+) to ADP-ribosylate histones [Tanny, J. C., Dowd, G. J., Huang, J., Hilz, H. & Moazed, D. (1999) Cell 99, 735-745; Frye, R. A. (1999) Biochem. Biophys. Res. Commun. 260, 273-279], deacetylate histones [Landry, J., Sutton, A., Tafrov, S. T., Heller, R. C., Stebbins, J., Pillus, L. & Sternglanz, R. (2000) Proc. Natl. Acad. Sci. USA 97, 5807-5811; Smith, J. S., Brachmann, C. B., Celic, I., Kenna, M. A., Muhammad, S., Starai, V. J., Avalos, J. L., Escalante-Semerena, J. C., Grubmeyer, C., Wolberger, C. & Boeke, J. D. (2000) Proc. Natl. Acad. Sci. USA 97, 6658-6663], or both [Imai, S., Armstrong, C. M., Kaeberlein, M. & Guarente, L. (2000) Nature (London) 403, 795-800]. Uncovering the true enzymatic function of SIR2 is critical to the basic understanding of its cellular function. Therefore, we set out to authenticate the reaction products and to determine the intrinsic catalytic mechanism. We provide direct evidence that the efficient histone/protein deacetylase reaction is tightly coupled to the formation of a previously unidentified acetyl-ADP-ribose product (1-O-acetyl-ADP ribose). One molecule of NAD(+) and one molecule of acetyl-lysine are readily catalyzed to one molecule of deacetylated lysine, nicotinamide, and 1-O-acetyl-ADP-ribose. A unique reaction mechanism involving the attack of enzyme-bound acetate or the direct attack of acetyl-lysine on an oxocarbenium ADP-ribose intermediate is proposed. We suggest that the reported histone/protein ADP-ribosyltransferase activity is a low-efficiency side reaction that can be explained through the partial uncoupling of the intrinsic deacetylation and acetate transfer to ADP-ribose.

Role of NAD(+) in the deacetylase activity of the SIR2-like proteins

In this report we describe the role of NAD(+) in the deacetylation reaction catalyzed by the SIR2 family of enzymes. We first show that the products of the reaction detected by HPLC analysis are ADP-ribose, nicotinamide, and a deacetylated peptide substrate. These products are in a 1:1:1 molar ratio, indicating that deacetylation involves the hydrolysis of one NAD(+) to ADP-ribose and nicotinamide for each acetyl group removed. Three results suggest that deacetylation requires an enzyme-ADP-ribose intermediate. First, the enzyme can promote an NAD(+) if nicotinamide exchange reaction that depends on an acetylated substrate. Second, a non-hydrolyzable NAD(+) analog is a competitive inhibitor of the enzyme, and, third, nicotinamide shows product inhibition of deacetylase activity.