Leukemia circulation kinetics revealed through blood exchange method

Leukemias and their bone marrow microenvironments undergo dynamic changes over the course of disease. However, little is known about the circulation kinetics of leukemia cells, nor the impact of specific factors on the clearance of circulating leukemia cells (CLCs) from the blood. To gain a basic understanding of CLC dynamics over the course of disease progression and therapeutic response, we apply a blood exchange method to mouse models of acute leukemia. We find that CLCs circulate in the blood for 1-2 orders of magnitude longer than solid tumor circulating tumor cells. We further observe that: (i) leukemia presence in the marrow can limit the clearance of CLCs in a model of acute lymphocytic leukemia (ALL), and (ii) CLCs in a model of relapsed acute myeloid leukemia (AML) can clear faster than their untreated counterparts. Our approach can also directly quantify the impact of microenvironmental factors on CLC clearance properties. For example, data from two leukemia models suggest that E-selectin, a vascular adhesion molecule, alters CLC clearance. Our research highlights that clearance rates of CLCs can vary in response to tumor and treatment status and provides a strategy for identifying basic processes and factors that govern the kinetics of circulating cells.

Leukemia circulation kinetics revealed through blood exchange method

Leukemias and their bone marrow microenvironment are known to undergo dynamic changes over the course of disease. However, relatively little is known about the circulation kinetics of leukemia cells, nor the impact of specific factors on the clearance of circulating leukemia cells (CLCs) from the blood. To gain a basic understanding of leukemia cell dynamics over the course of disease progression and therapeutic response, we apply a blood exchange method to mouse models of acute leukemia. We find that CLCs circulate in the blood for 1-2 orders of magnitude longer than solid tumor circulating tumor cells. We further observe that: i) leukemia presence in the marrow can limit the clearance of CLCs in a model of acute lymphocytic leukemia (ALL), and ii) CLCs in a model of relapsed acute myeloid leukemia (AML) can clear faster than their untreated counterparts. Our approach can also directly quantify the impact of microenvironmental factors on CLC clearance properties. For example, data from two leukemia models suggest that E-selectin, a vascular adhesion molecule, alters CLC clearance. Our research highlights that clearance rates of CLCs can vary in response to tumor and treatment status and provides a strategy for identifying basic processes and factors that govern the kinetics of circulating cells.

Observation of photo-induced plasmon-phonon coupling in PbTe via ultrafast x-ray scattering

We report the observation of photo-induced plasmon-phonon coupled modes in the group IV-VI semiconductor PbTe using ultrafast x-ray diffuse scattering at the Linac Coherent Light Source. We measure the near-zone-center excited-state dispersion of the heavily screened longitudinal optical (LO) phonon branch as extracted from differential changes in x-ray diffuse scattering intensity following above bandgap photoexcitation. We suggest that upon photoexcitation, the LO phonon-plasmon coupled (LOPC) modes themselves become coupled to longitudinal acoustic modes that drive electron band shifts via acoustic deformation potentials and possibly to low-energy single-particle excitations within the plasma and that these couplings give rise to displacement-correlations that oscillate in time with a period given effectively by the heavily screened LOPC frequency.

A88 UNDERSTANDING NURSE PERCEPTIONS OF CARING FOR PATIENTS WITH ALCOHOL USE DISORDER: A CROSS-SECTIONAL STUDY

Background

Alcohol Use Disorder (AUD), the problematic consumption of alcohol, affects 107 million people worldwide. AUD increases morbidity and mortality and has a substantial impact on daily functioning including quality of life, relationships and employment. AUD is particularly detrimental in patients who already have liver damage like cirrhosis. The management of AUD includes screening, brief intervention and referral to treatment for psychological and pharmacotherapy based treatment. People with AUD have frequent interactions with the healthcare system. These interactions represent opportunities to engage patients with therapy. As front-line workers who have maximal contact with patients, nurses practicing in acute care are in an ideal position to initiate AUD related discussion with patients. Prior to the design of an educational intervention to increase nursing engagement with AUD screening and brief intervention, there is a need to understand baseline knowledge, attitudes and perceptions in this group.

Aims

The aim of the present study was to explore the knowledge, attitudes and perceptions of nurses caring for patients with cirrhosis and AUD.

Methods

We conducted a cross-sectional survey using the Survey of Attitudes and Perceptions (SAP). The SAP is derived from a validated tool to assess attitudes and perceptions towards patients with AUD. Anonymous surveys were distributed on inpatient medicine units across 5 geographic zones in Alberta between September 2019-March 2020. Data were analyzed using descriptive and inferential statistics.

Results

A total of 93 nurses from 7 inpatient medicine units across Alberta participated in the study. The majority of participants were Registered Nurses (74.9%), who practiced in an urban setting (69%), and had worked in their role for an average of 9.9 years. Few (22.6%) participants reported any prior structured education on caring for patients with AUD, with the majority reporting limited knowledge of alcohol and effects of alcohol consumption. Though most reported that caring for patients with AUD was part of their professional role, only 15.7% felt motivated to work with this group of patients. Responses to individual questions or sub-domains of the survey did not significantly differ by length or time in professional role, or practice setting.

Conclusions

Our results indicate that nurses have limited knowledge on caring for patients with AUD. Given the importance of AUD in the development and progression of cirrhosis as well as the frequency of hospitalizations for patients with cirrhosis, increasing nurse knowledge of AUD is crucial to improving the quality of care for these patients. The results of this study will be used to inform the development of an educational intervention to increase nursing knowledge of caring for patients with cirrhosis and AUD.

Funding Agencies

Alberta Innovates

Measuring kinetics and metastatic propensity of CTCs by blood exchange between mice

Existing preclinical methods for acquiring dissemination kinetics of rare circulating tumor cells (CTCs) en route to forming metastases have not been capable of providing a direct measure of CTC intravasation rate and subsequent half-life in the circulation. Here, we demonstrate an approach for measuring endogenous CTC kinetics by continuously exchanging CTC-containing blood over several hours between un-anesthetized, tumor-bearing mice and healthy, tumor-free counterparts. By tracking CTC transfer rates, we extrapolated half-life times in the circulation of between 40 and 260 s and intravasation rates between 60 and 107,000 CTCs/hour in mouse models of small-cell lung cancer (SCLC), pancreatic ductal adenocarcinoma (PDAC), and non-small cell lung cancer (NSCLC). Additionally, direct transfer of only 1-2% of daily-shed CTCs using our blood-exchange technique from late-stage, SCLC-bearing mice generated macrometastases in healthy recipient mice. We envision that our technique will help further elucidate the role of CTCs and the rate-limiting steps in metastasis.

Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of ^{7}Be in Superconducting Quantum Sensors

Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal to the dark sector. We report a new search for the existence of sub-MeV sterile neutrinos using the decay-momentum reconstruction technique in the decay of ^{7}Be. The experiment measures the total energy of the ^{7}Li daughter atom from the electron capture decay of ^{7}Be implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first experiment presents data from a single STJ operated at a low count rate for a net total of 28 days, and provides exclusion limits on sterile neutrinos in the mass range from 100 to 850 keV that improve upon previous work by up to an order of magnitude.

Direct Measurement of the ^{7}Be L/K Capture Ratio in Ta-Based Superconducting Tunnel Junctions

We report a high-statistics measurement of the L/K orbital electron capture ratio in ^{7}Be embedded in cryogenic Ta. The thin Ta film formed part of a high-resolution superconducting tunnel junction radiation detector that was used to identify the signals from different decay channels. The measured L/K capture ratio of 0.070(7) is significantly larger than the only previous measurement of this quantity and the theoretical predictions that include in-medium effects. This value is a uniquely sensitive probe of the 1s and 2s orbital overlaps with the nucleus and is of relevance to nuclear and atomic physics, as well as Li production in novae and other astrophysical scenarios. This is the first experiment that uses superconducting tunnel junctions for nuclear-recoil detection, opening a new experimental avenue for low-energy precision measurements with rare isotopes.

Characterization of the Observed Electric Field and Molecular Relaxation Times for Millimeter-Wave Chirped Pulse Instrumentation

In a chirped pulse experiment, the strength of the signal level is proportional to the amplitude of the electric field, which is weaker in the millimeter-wave or submillimeter-wave region than in the microwave region. Experiments in the millimeter region thus require an optimization of the coupling between the source and the molecular system and a method to estimate the amplitude of the electric field as seen by the molecular system. We have developed an analytical model capable of reproducing the coherent transient signals obtained with a millimeter-wave chirped pulse setup operated in a monochromatic pulse mode. The fit of the model against the experimental data allowed access to the amplitude of the electric field and, as a byproduct, to the molecular relaxation times T ₁ and T ₂.

Conformational landscape and inertial defect of methoxyphenol isomers studied by mm-wave spectroscopy and quantum chemistry calculations

Because methoxyphenols (MP) are emitted in significant quantities during biomass fires and contribute to the secondary organic aerosols formation which impacts the climate, their gas phase monitoring in the atmosphere is crucial and requires accurate rovibrational cross sections determined with a good knowledge of their ground state (GS) and vibrationally excited state (ES) molecular parameters. Therefore, the rotational spectra of the two isomers, 2-MP (guaïacol) and 4-MP (mequinol), have been measured in absorption and in emission at room temperature using a frequency multiplication chain and a mm-wave Fourier transform chirped-pulse spectrometer, respectively. Guided by quantum chemistry calculations, the conformational landscape has been characterised and the observation of only one rotamer in the spectra of 2-MP and 4-MP has been explained. For 2-MP, the most stable conformation is justified by an intramolecular O-H⋯OCH₃ hydrogen-bond which has been characterised by a topology analysis of the electron density. In a global fit including more than 30 000 line assignments, rotational and quartic centrifugal constants of the GS and the three lowest energy ES have been determined allowing to reproduce the millimeter-wave spectra at the experimental accuracy. The same work has been performed on the cis-rotamer of 4-MP highlighting some perturbations marring the fit quality for two vibrationally ES. Finally, the isomeric dependence of the negative inertial defect ΔI agrees with that of the lowest energy out of plane mode ν₄₅, and the variation of ΔI with the degree of vibrational excitation allows a fine estimation of v₄₅ = 1 vibrational wavenumber.

The origin of incipient ferroelectricity in lead telluride

The interactions between electrons and lattice vibrations are fundamental to materials behaviour. In the case of group IV–VI, V and related materials, these interactions are strong, and the materials exist near electronic and structural phase transitions. The prototypical example is PbTe whose incipient ferroelectric behaviour has been recently associated with large phonon anharmonicity and thermoelectricity. Here we show that it is primarily electron-phonon coupling involving electron states near the band edges that leads to the ferroelectric instability in PbTe. Using a combination of nonequilibrium lattice dynamics measurements and first principles calculations, we find that photoexcitation reduces the Peierls-like electronic instability and reinforces the paraelectric state. This weakens the long-range forces along the cubic direction tied to resonant bonding and low lattice thermal conductivity. Our results demonstrate how free-electron-laser-based ultrafast X-ray scattering can be utilized to shed light on the microscopic mechanisms that determine materials properties.

Group IV–VI materials often exist in a state near an electronic or structural phase transition. Here, the authors use ultrafast X-ray scattering to show that coupling of band-edge electrons and phonons causes the ferroelectric instability observed in lead telluride.

P4-16-05: A Randomized Phase 2 Study of a Loading Dose of Ibandronate in Patients with Bone Metastases from Breast Cancer

Bisphosphonates have proven efficacy in reducing skeletal complications in metastatic breast cancer. Potent third generation bisphosphonates are more effective but the dose limiting toxicity is usually renal. Ibandronate is a 3rd generation bisphosphonate available in oral and intravenous form which offers many clinical advantages in ease of administration and lack of renal toxicity. A dose-response effect has been observed between 2mg and 6 mg IV doses and there is a single study suggesting that higher dosing (4 mg IV daily for 3 days) is tolerable and effective. A steady state of oral ibandronate is achieved at 8 days with oral administration but time to response is not known. In trials so far, IV ibandronate 6mgs appears safe. Due to lack of renal toxicity there is potential for further escalation of IV ibandronate. The objective of this study was to establish if an IV loading dose can improve efficacy and time to biochemical response compared to oral standard therapy and to assess the safety of a higher IV dose of ibandronate.

Methods and Patients: This was an open randomised phase II study conducted on patients with bone metastases from breast cancer comparing IV ibandronate 12 mg on day 1 followed by oral ibandronate 50 mgs daily (Arm A) with standard oral therapy of 50 mgs daily from day 1 (Arm B). The primary study end-point was the percentage reduction in serum CTX from baseline by day 5 on study, secondary end- points were the percentage reduction of bone turnover markers including serum CTX from baseline end of week 8 and percentage reduction in urine NTX from baseline to day 5 on study and baseline to end of week 1–8. Bone pain was recorded by Brief Pain Inventory. Patients had metastatic breast cancer with proven bone metastases, no previous treatment with bisphosphonates or other bone directed therapy within 6 months and no change in systemic therapy within a 3 months preceding trial therapy. Sample size of 22 patients in each arm was calculated to give a 90% chance detecting a 20% difference in average percentage reduction between the IV and oral arms.

Results: Seventeen patients were randomised to each study arm. A more rapid change in bone turnover markers was demonstrated in patients recieving the 12 mg loading dose of ibandronate. There was a 15.8% greater reduction of serum CTX in Arm A compared with Arm B at day 5, p=0.005. The percentage reduction of serum PINP at day 5 was also greater in Arm A, p=0.002. Over the 8 week period of study there was no overall significant difference in bone turnover markers. All patients had pain at study entry, median baseline pain severity scores were 3 in study arm and 4 in controls. Average bone pair score remained higher in treatment arm B at the end of 8 weeks. There were no additional adverse side-effects following administration of 12 mg of IV ibandronate and no evidence of additional renal toxicity. Conclusion: A 12 mg dose of IV ibandronate can be safely administered without additional renal toxicity. A rapid reduction in bone turnover markers is demonstrated within 5 days of IV loading dose of ibandronate. Potential exists for dose escalation of ibandronate. The clinical benefit of a more rapid reduction in bone turnover markers is unknown.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-16-05.

Melanoma incidence and mortality in Scotland 1979-2003

We studied 12,450 cases of invasive melanoma diagnosed in Scotland in 1979-2003, by thickness, pathological type, and body site at ages under 40, 40-59, and 60 years and over. Melanoma incidence trebled in males from 3.57 to 10.93/10(5) per year, and increased 2.3-fold in females from 5.60 to 12.96/10(5) per year. The rate of increase fell in each successive 5-year period. The greatest increase was in males aged 60 years and over at diagnosis. Significant incidence increases were seen in melanomas < 1 mm in all three age groups, but those > 4 mm only increased significantly at ages 60 years and over. All histological types increased significantly at ages 60 years and over, and in this age group the greatest increase was seen on the head and neck. Five-year disease-free survival improved steadily. Survival figures for 1994-1998 ranged from 93.6% for males and 95.8% for females with tumours < 1 mm, to 52.4 and 48.3%, respectively, for those with tumours > 4 mm. Over the 25 years, melanoma mortality doubled in males from 1.1 to 2.4/10(5) per year, but was unchanged in females at 1.5/10(5) per year. Public education on melanoma is required both for primary prevention and earlier diagnosis, particularly for older males.

Acetylcholine causes an increase of intracellular calcium in human sperm

Sperm nicotinic acetylcholine receptors (nAChRs) can influence motility and the initiation of acrosome reaction (AR). We report that AR initiation by acetylcholine (ACh) in capacitated human sperm requires both Na+ and Ca2+ in the external medium. Pre-incubation with 50 microM 3-quinuclidinyl benzilate (QNB) or 50 nM strychnine failed to inhibit the ACh-initiated AR, demonstrating that muscarinic AChRs and nAChRs containing alpha9 subunits do not mediate this event. Choline (2.5, 5 and 10 mM), a highly specific but low potency agonist of the alpha7 nAChR initiated AR, with its effect blocked by the nAChR antagonist methyllycaconitine (MLA). ACh (50-400 microM) stimulated a small transient rise in the intracellular Ca2+ in sperm populations loaded with FURA-2, with 200 microM ACh being maximal (146 nM +/- 23 SEM). The nAChR antagonists, alpha-bungarotoxin (alpha-BTX) and MLA, reduced the ACh-initiated Ca2+ rise by 75 and 78%, respectively, demonstrating the majority of the rise is mediated through nAChRs containing alpha7 or alpha9 subunits. Single cell imaging studies using FLUO-3 resolved two patterns of ACh-stimulated Ca2+ increase in the sperm head: 94% of responding sperm displayed a rise (59.6% +/- 5.7 SEM increase from resting fluorescence intensity), returning to resting levels over a period of 2-3 min. The remaining sperm (6%) displayed a sharp spike of Ca2+ ( approximately 1 min; 86% +/- 4.3 SEM change in fluorescence intensity), followed by abrupt loss of fluorescence, a pattern suggestive of AR. A Ca2+ influx in the sperm midpiece appeared to accompany the Ca2+ influx seen in the head. These observations confirm an ionotropic role for nAChRs in sperm function.

Effects of resolution reduction on data analysis

BACKGROUND

There is often a need in flow cytometry to display and analyze histograms at resolutions lower than those native to the data. It is common, for example, to analyze DNA histograms at 256-channel resolution, even though the data were acquired at 1,024 channels or more. The most common method for reducing resolution, referred to as the consecutive summation (CS) method, can introduce distortions into the shape of histograms. Peaks that were symmetric in the original data can become skewed in the reduced-resolution histogram. Data analysis can be negatively affected by the distortions produced by reducing the histogram resolution. An alternative technique for reducing histogram resolution, the unbiased summation (US) method, minimizes shape distortion. This paper describes the US method and examines the benefits it provides in the analysis of DNA histograms.

METHODS

Reduced chi-square (RCS) was used to measure the response to three experimental variables in the least-squares analysis of simulated DNA histograms. For each variable (the percentage of coefficient of variation [%CV], number of events, and mean position of the G1 distribution), a test data set of 1,000 histograms was generated at 1,024-channel resolution. Histogram resolutions were reduced with each method and then analyzed with ModFit LT cell-cycle analysis software (Verity Software House, Topsham, ME). S-phase error and processor computation time of each method also were evaluated. A Monte Carlo experiment was performed to compare CS and US methods to theoretically correct reductions.

RESULTS

CS method analysis results were negatively affected by changes in %CV, number of events, and G1 peak position. The US method produced consistently lower RCS values (more accurate results) within the tested ranges. The US method eliminated bias in S-phase error and had negligible impact on analysis processing speed. It improved RCS values 44.50% on average (P < 0.0002) with actual DNA histograms. Whereas the CS method became less accurate (chi-square test) as the amount of reduction increased, the US method was unaffected, producing consistently better results.

CONCLUSIONS

The US method is recommended for reducing histogram resolution in modeling applications such as DNA cell-cycle analysis. It may have implications in other areas of flow cytometric data analysis.

Inhibitors of receptor tyrosine kinases do not suppress progesterone-induced [Ca2+]i signalling in human spermatozoa

Previous studies have implicated receptor tyrosine kinases in progesterone-induced [Ca2+]i signalling, and consequent induction of the acrosome reaction, in human spermatozoa. We have investigated the effects of tyrosine kinase inhibition on [Ca2+]i responses in large numbers of individual human spermatozoa. Genistein (5, 50 and 250 micromol/l), an inhibitor of receptor-linked tyrosine kinases, significantly inhibited the progesterone-induced acrosome reaction (P < 0.05). However, we could detect no effect of genistein on progesterone-induced [Ca2+]i signalling. In control experiments, application of progesterone induced a significant transient [Ca2+]i response in approximately 77% of cells and a sustained [Ca2+]i ramp/plateau in approximately 48% of cells (n = 26; 5411 cells). In preparations pretreated with genistein (50 micromol/l), significant transient and sustained responses were detected in 69.5 and 39.1% of cells respectively (n = 5; 1109 cells). The amplitudes of both transient and sustained [Ca2+]i responses were similar in control and genistein-pretreated preparations. Tyrphostin A47 (100 micromol/l), another receptor tyrosine kinase inhibitor, also failed to inhibit either the transient or sustained [Ca2+]i response (n = 3; 468 cells). Assessment of tyrosine phosphorylation of two sperm proteins (p105/81) showed greatly increased levels of phosphotyrosine in response to capacitation but a negligible increase in response to progesterone stimulation. Pretreatment with genistein (50 and 250 micromol/l) decreased capacitation-induced tyrosine phosphorylation and resulted in a loss of phosphorylation in response to progesterone treatment. We conclude that neither the transient nor sustained phases of the progesterone-induced [Ca2+]i response require receptor tyrosine kinase signalling. Previous reports of modulation of the progesterone-induced [Ca2+]i signal by tyrosine kinase inhibition probably reflect inhibition of the acrosome reaction.

Bullying nurses at work: theorizing a gendered experience

This paper is about bullying among nurses at work. It presents the psychoanalytically based theory that workplace bullies, impaired during infancy by primary caregivers who were less than loving, project their own hostile personalities onto others and then relate to others without empathy or understanding, in demeaning ways. When these hostile people are employed in a masculine workplace, they protest against the gendered imperatives imposed upon them, hysterically. Because of the masculinization of the workplace, hysterical bullying varies according to gender, with women bullying in a hostile connected way, and men bullying in a hostile separated way. Research data gathered in Canada in the 1990s is utilised in presenting the theories. Suggestions about anti-bullying practices that arise from this theoretical analysis conclude the work.

Biphasic elevation of [Ca(2+)](i) in individual human spermatozoa exposed to progesterone

Fluorimetric studies on progesterone-induced [Ca(2+)](i) signalling in mammalian spermatozoa show both the well-characterised [Ca(2+)](i) transient and a subsequent sustained phase. However, the sustained phase is thought to reflect release of the fluorochrome during the acrosome reaction and has not been subject to critical investigation. We have used single-cell imaging of [Ca(2+)](i) to analyse the progesterone-induced [Ca(2+)](i) response in large numbers (>2000) of capacitated, human spermatozoa. In 70% of cells, treatment with progesterone induced a transient increase, which typically peaked within 1 min and decayed with a similar time course. Upon rapid application of progesterone this response peaked within 5-20 s. In 35% of progesterone-treated spermatozoa a sustained elevation of [Ca(2+)](i) occurred, which became discernible during the falling phase of the transient response and persisted for at least 20 min. Both [Ca(2+)](i) responses were localised to the postacrosomal region. Averaging of large numbers of single cell responses generated traces similar to those seen in fluorimetric studies. Although the sustained response was strongly associated with the initial, transient response, a few spermatozoa generated sustained responses that were not preceded by a significant transient response (5% of cells). It is concluded that a genuine biphasic [Ca(2+)](i) signal is activated by progesterone and that the sustained response is a discrete signalling event with biological significance.

Divergent views--patient, career and staff perceptions of diagnosis and reasons for psychiatric admission to a district general hospital

This study explores the differing perceptions of patients, carers, and professional staff in relation to psychiatric admission. There is poor to moderate agreement between lay people and professional beliefs about diagnosis or purpose of admission, although good agreement about the necessity of admission. The chronicity of symptoms in admitted patients and a rural-urban divide in rates of admissions are also noted.

Renal chromophobe cell carcinoma: limitations of paraffin-embedded tissue

Chromophobe cell carcinoma of the kidney is distinguished from other renal cortical tumors by the ultrastructural presence of numerous cytoplasmic vesicles of unknown composition. Failure to detect vesicles in paraffin-embedded tissue in the archival material of 10 putative chromophobe cell tumors stimulated an investigation into the effects of fixatives and dehydrating solvents on vesicle integrity. We found that although vesicles are removed by dehydrating agents during paraffin embedding, osmium tetroxide postfixation prevents vesicle loss during dehydration for electron microscopy. We conclude that paraffin-embedded tissue is useless for histochemical studies of vesicle composition and cannot be employed for the ultrastructural confirmation of a histologic diagnosis of chromophobe cell carcinoma since the intracellular vesicles are no longer present.

Cytokeratin-containing globular filamentous bodies in renal oncocytoma

Eighty-four cortical neoplasms were studied for cytokeratin and vimentin expression by immunohistochemistry and for intermediate filament aggregates by electron microscopy. Twenty oncocytomas expressed cytokeratin, 16 in a distinctive punctate pattern. These same 16 tumors also contained small globular filamentous bodies (GFB) by electron microscopy. The GFB were characterized by a matrix of intermediate-sized filaments with incorporation of diverse cell organelles such as endoplasmic reticulum, lysosomes, mitochondria, and lipid. The GFB were not within a unit membrane. Although 11 of 64 carcinomas also contained intermediate filament aggregates, only 2 of these solely expressed cytokeratin, and this was restricted to a few cells in small foci. Small GFB were also present in 5 carcinomas by electron microscopy. Three mixed clear and granular cell carcinomas contained only rare cells, whereas 2 sarcomatoid carcinomas, both of rhabdoid cell phenotype, contained numerous GFB that coexpressed vimentin and cytokeratin. Cytokeratin-containing GFB are common in oncocytomas but are uncommon in carcinoma, and, when numerous, may provide a diagnostically useful immunohistochemical feature with which to distinguish oncocytoma from its carcinoma congeners.

Changes in salbutamol concentration in the reservoir solution of a jet nebulizer

An increase in concentration of salt in the reservoir solution of jet nebulizers driven by dry compressed gas has been observed but changes in salbutamol concentration have not been investigated; therefore: Concentration changes were observed following 10 minutes nebulization for two driving sources and starting volumes. Using an electric compressor, the time courses of changes in drug concentration and output were observed for a 5 mg dose of salbutamol in 2 and 4 ml starting volumes. Changes in drug concentration were smaller for a 4 ml starting volume and for compressor driven nebulizers. Salbutamol concentration increased with the length of nebulization and the rate of increase was inversely related to starting volume. There was poor agreement between fluid and drug output for the 2 ml starting volume and drug output did not increase significantly when nebulization exceeded 4 minutes. For the 4 ml fill there was closer agreement between fluid and drug output and drug output exceeded that for the 2 ml fill after 10 minutes. In conclusion, fluid output alone is an inadequate measure of drug output and changes in drug concentration cannot be overlooked when assessing nebulizers for nebulizer therapy.

Comparison of oxyfedrine and atenolol in angina pectoris--a double-blind study

We have compared oxyfedrine 24 mg four times daily with atenolol 100 mg once daily in the relief of angina pectoris in a double-blind cross-over study; assessments were by diary cards and treadmill testing. Both oxyfedrine and atenolol reduced the frequency of angina by similar amounts and both produced similar improvements in treadmill performance. Side effects were infrequent and minor with both drugs. The model of action of oxyfedrine appears to be different from atenolol. Oxyfedrine allows the double product of systolic blood pressure X heart rate at peak exercise to be maintained at levels similar to those with placebo; the double product at peak exercise is significantly less with atenolol.

Reduction in infarct size, arrhythmias and chest pain by early intravenous beta blockade in suspected acute myocardial infarction

Four hundred seventy-seven patients suspected of having had acute myocardial infarction within less than 12 hours were randomized to receive i.v. atenolol followed by oral treatment for 10 days or to a control group. In patients with ECG changes indicative of infarction at entry, i.v. atenolol significantly reduced enzyme release by one-third and enhanced R-wave preservation. In patients without such ECG changes, treatment significantly prevented the development of infarction in a proportion of patients. There was also a significant reduction in R-on-T ectopics, repetitive ventricular arrhythmias and supraventricular arrhythmias. Treated patients had significantly greater pain relief and required fewer opiate analgesics. Significantly fewer atenolol-treated patients died by 10 days (the treatment period), had nonfatal cardiac arrests, developed heart failure, or suffered reinfarction.

Early intravenous atenolol treatment in suspected acute myocardial infarction. Preliminary report of a randomised trial

214 patients were studied in a randomised trial to determine whether administraiton of intravenous atenolol within 12 hours of chest pain reduced eventual infarct size, as estimated by cumulative enzyme release and by ECG changes. 135 patients already had ECG evidence of infarction at entry; 72 received atenolol which significantly decreased subsequent enzyme release (atenolol and control means = 121 IU, SE +/- 10 and 177 IU, SE +/- 17; 2p < 0.005) and enhanced R-wave preservation (atenolol and control means = 46% +/- 3 and 36% +/- 3; 2p < 0.02). 79 patients had no evidence of infarction at entry; 44 did not receive atenolol and 27 of these subsequently developed infarction, whereas only 11 of 35 treated patients infarcted during their hospital stay (2p < 0.01). In hospital, fewer atenolol patients died (4 vs 9), had non-fatal cardiac arrests (2 vs 6), or required therapy for heart-failure (36 vs 47). Unlike many previous trials which had negative results, in this trial we gave the drug intravenously and promptly (median of 4 hours from onset of pain to injecton), thereby achieving early beta-blockade.