Long Term Patient Reported Quality of Life Outcomes and Patient Satisfaction of 1-Week Hypofractionated Whole Breast Radiation Therapy Using IMRT for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

Novel whole breast radiation therapy (WBRT) regimens have been recently reported with the aim of improving patient convenience while preserving local control and breast cosmesis. The UK FAST Forward trial showed that 26 Gy in 5 fx using 3D conformal WBRT was equivalent to the standard 3-week regimen. However, the use of inverse planned intensity modulated radiation therapy (IMRT) for this novel ultra-hypofractionated regimen has not been previously studied. We aim to study the patient reported quality of life (QOL) outcomes and patient satisfaction of WBRT using IMRT delivering 26 Gy in 5 fractions.

MATERIALS/METHODS

Patients receiving WBRT with 26 Gy in 5 fractions using IMRT at our institution from 2020 to 2022 were included. Patients were treated with 26 Gy in 5 daily fx with or without a single fx boost of 4-5.2 Gy. IMRT plans were generated using inverse planning with 2 to 3 volumetric modulated arcs (VMAT). To assess patient-reported QOL outcomes, a questionnaire was prospectively administered at 1 month post treatment and yearly thereafter including the EORTC QLQ-BR23 breast cancer module and other patient satisfaction questions. Patient assessment involved a four-point scale (not at all, a little, quite a bit, and very much; very satisfied, moderately satisfied, moderately dissatisfied, and very dissatisfied). Here, we report the 1-year patient reported acute toxicity QOL outcomes and patient satisfaction for those undergoing IMRT based WBRT. Cross-sectional analyses were used to determine the prevalence of "quite a bit" or "very much" effects versus "not at all" or "a little" effects.

RESULTS

A total of 96 patients were included. The median age at diagnosis was 65 years. The most common histology was invasive ductal carcinoma (53.1%). ER-positivity was found in 75.5% patients. Oncoplastic reconstruction was used in 51.0% patients. The median tumor size was 1.5 cm. There were 4/98 (4.3%) node positive patients and 22.5% received adjuvant chemotherapy. Endocrine therapy was used in 74.5% patients. A boost fraction was delivered in 95.9% patients. At the 1-year assessment, only 1/35 (2.9%), 2/35 (5.7%), and 4/35 (11.4%) patients reported "quite a bit" or "very much" breast pain, skin problems, and changes in breast appearance respectively. Additionally, 32/35 (91.4%) patients were either "very satisfied" or "moderately satisfied" with their treatment, while 32/35 (91.4%) patients reported "excellent" (n = 12) or "good" (n = 20) physical appearance of the breast.

CONCLUSION

WBRT using inverse planned IMRT with 26 Gy in 5 fx shows excellent patient reported QOL and patient satisfaction at 1-year post RT. Longer follow up is needed to assess the long-term toxicity, normal tissue effects, and cosmetic outcomes of IMRT based delivery of this ultra-hypofractionated regimen.

Zebrafish anterior segment mesenchyme progenitors are defined by function of tfap2a but not sox10

The anterior segment is a critical component of the visual system. Developing independent of the retina, the AS relies partially on cranial neural crest cells (cNCC) as its earliest progenitors. The cNCCs are thought to first adopt a periocular mesenchyme (POM) fate and subsequently target to the AS upon formation of the rudimentary retina. AS targeted POM is termed anterior segment mesenchyme (ASM). However, it remains unknown when and how the switch from cNCC to POM or POM to ASM takes place. As such, we sought to visualize the timing of these transitions and identify the regulators of this process using the zebrafish embryo model. Using two color fluorescence in situ hybridization, we tracked cNCC and ASM target gene expression from 12 to 24hpf. In doing so, we identified a tfap2a and foxC1a co-expression at 16hpf, identifying the earliest ASM to arrive at the AS. Interestingly, expression of two other key regulators of NCC, foxD3 and sox10 was not associated with early ASM. Functional analysis of tfap2a, foxD3 and sox10 revealed that tfap2a and foxD3 are both critical regulators of ASM specification and AS formation while sox10 was dispensable for either specification or development of the AS. Using genetic knockout lines, we show that in the absence of tfap2a or foxD3 function ASM cells are not specified, and subsequently the AS is malformed. Conversely, sox10 genetic mutants or CRISPR Cas9 injected embryos displayed no defects in ASM specification, migration or the AS. Lastly, using transcriptomic analysis, we show that GFP + cNCCs derived from Tg [foxD3:GFP] and Tg [foxC1b:GFP] share expression profiles consistent with ASM development whereas cNCCs isolated from Tg [sox10:GFP] exhibit expression profiles associated with vasculogenesis, muscle function and pigmentation. Taken together, we propose that the earliest stage of anterior segment mesenchyme (ASM) specification in zebrafish is approximately 16hpf and involves tfap2a/foxC1a positive cNCCs.

Contrast-enhanced ultrasound for abdominal image-guided procedures

INTRODUCTION

Since FDA approval for contrast-enhanced ultrasound (CEUS), clinical applications have increased to include diagnostic imaging of hepatic, renal, and other abdominal lesions. The modality has also demonstrated utility in certain image-guided procedures. Intravascular ultrasound contrast agents use microbubbles to improve visibility of solid tumors. Lesions not well seen on grayscale or Doppler ultrasound may become amenable to CEUS-guided biopsy or ablation.

MATERIALS AND METHODS

This pictorial essay provides eleven examples to illustrate the current use of CEUS in a variety of abdominal image-guided procedures. Hepatic, renal, peritoneal, and soft tissue cases are presented.

CONCLUSION

CEUS can improve visualization and targeting in abdominal image-guided procedures, without nephrotoxicity or radiation exposure.

Quality improvement time-saving intervention to increase use of a clinical decision support tool to reduce low-value diagnostic imaging in a safety net health system

Importance

Electronic health record (EHR) clinical decision support (CDS) tools can provide evidence-based feedback at the point of care to reduce low-value imaging. Success of these tools has been limited partly due to lack of engagement by busy clinicians.

Objective

Measure the impact of a time-saving quality improvement intervention to increase engagement with a CDS tool for low back pain imaging ordering.

Design, setting and participants

We conducted a quasi-experimental difference-in-differences analysis at (BLINDED), examining back pain imaging orders from 29 May 2015 to 07 January 2016. The intervention site was (BLINDED) Emergency Medicine/Urgent Care Center (n=5736) and control sites included all other (BLINDED) hospitals and clinics (n=1621). In May 2015, the Department of Health Services installed a CDS tool that triggered a survey when clinicians ordered an imaging test, generating an ‘appropriateness score’ based on the American College of Radiology guidelines. Clinicians often bypassed the tool, resulting in ‘unscored’ tests.

Intervention

To increase clinician engagement with the tool and decrease the rate of unscored imaging tests, a new policy was implemented at the intervention site on 15 August 2015. If clinicians completed the CDS survey and scored an appropriateness score >3, they could forego a previously mandatory telephone call for pre-imaging utilisation review with the radiology department.

Main outcomes and measures

We used EHR data to measure pre–post-intervention differences in: (1) percentage of unscored tests and (2) percentage of tests with high appropriateness scores (>7).

Results

Percentage of unscored tests decreased from 69.4% to 10.4% at the intervention site and from 50.6% to 34.8% at the control sites (between-group difference: −23.3%, p<0.001). Percentage of high scoring tests increased from 26.5% to 75.0% at the intervention site and from 17.2% to 22.7% at the control sites (between-group difference: 19%, p<0.001).

Conclusion

Workflow time-saving interventions may increase physician engagement with CDS tools and have potential to improve practice patterns.

Neoplasms of the Appendix: Pictorial Review with Clinical and Pathologic Correlation

Appendiceal neoplasms are uncommon tumors of the gastrointestinal tract that may manifest with symptoms of appendicitis, right lower quadrant pain, or palpable mass, leading to imaging or surgical intervention. The majority of appendiceal masses consist of primary epithelial neoplasms and neuroendocrine tumors (NETs). Epithelial neoplasms-mucinous and nonmucinous types-are more often detected at imaging than NETs due to their larger size and propensity for peritoneal spread and metastatic disease. Epithelial mucinous neoplasms are defined by the presence of mucin, detected at radiologic and pathologic examination. A mucocele or pseudomyxoma peritonei from epithelial mucinous tumors are the two most common cross-sectional imaging findings of appendiceal mucinous neoplasms. Nonmucinous epithelial tumors are less common and manifest as masses similar to colonic-type malignancies. NETs are often discovered incidentally at appendectomy due to their small size and nonaggressive behavior. Imaging findings of primary appendiceal tumors may overlap with those of acute appendicitis. Additionally, an appendiceal mass may cause acute appendicitis, obscuring the underlying mass. Other neoplasms including lymphoma, sarcoma, mesenchymal and nerve sheath tumors, or secondary malignant involvement of the appendix are rare. Treatment depends on the histologic subtype and extent of disease. Detailed description of organ, nodal, and peritoneal involvement informs surgical management with the goal of complete cytoreduction. Novel treatments such as hyperthermic intraperitoneal chemotherapy have increased survival for patients with mucinous tumors. ^©RSNA, 2017.

Multistate outbreak of Escherichia coli O145 infections associated with romaine lettuce consumption, 2010

Non-O157 Shiga toxin-producing Escherichia coli (STEC) can cause severe illness, including hemolytic uremic syndrome (HUS). STEC O145 is the sixth most commonly reported non-O157 STEC in the United States, although outbreaks have been infrequent. In April and May 2010, we investigated a multistate outbreak of STEC O145 infection. Confirmed cases were STEC O145 infections with isolate pulsed-field gel electrophoresis patterns indistinguishable from those of the outbreak strain. Probable cases were STEC O145 infections or HUS in persons who were epidemiologically linked. Case-control studies were conducted in Michigan and Ohio; food exposures were analyzed at the restaurant, menu, and ingredient level. Environmental inspections were conducted in implicated food establishments, and food samples were collected and tested. To characterize clinical findings associated with infections, we conducted a chart review for case patients who sought medical care. We identified 27 confirmed and 4 probable cases from five states. Of these, 14 (45%) were hospitalized, 3 (10%) developed HUS, and none died. Among two case-control studies conducted, illness was significantly associated with consumption of shredded romaine lettuce in Michigan (odds ratio [OR] = undefined; 95% confidence interval [CI] = 1.6 to undefined) and Ohio (OR = 10.9; 95% CI = 3.1 to 40.5). Samples from an unopened bag of shredded romaine lettuce yielded the predominant outbreak strain. Of 15 case patients included in the chart review, 14 (93%) had diarrhea and abdominal cramps and 11 (73%) developed bloody diarrhea. This report documents the first foodborne outbreak of STEC O145 infections in the United States. Current surveillance efforts focus primarily on E. coli O157 infections; however, non-O157 STEC can cause similar disease and outbreaks, and efforts should be made to identify both O157 and non-O157 STEC infections. Providers should test all patients with bloody diarrhea for both non-O157 and O157 STEC.

Development and Validation of HPTLC Method for Simultaneous Determination of Amlodipine Besylate and Metoprolol Succinate in Bulk and Tablets

A simple, selective, precise high-performance thin-layer chromatographic method for simultaneous determination of amlodipine besylate and metoprolol succinate in bulk and pharmaceutical combined dosage form was developed and validated. The method employed HPTLC aluminum plates precoated with silica gel 60F-254 (10×10) as the stationary phase. The solvent system consisted of toluene:ethyl acetate:methanol:triethylamine (4:1:1:0.4 v/v/v). The system was found to give a compact spot for amlodipine besylate (R(f) = 0.39±0.02) and metoprolol succinate (R(f) = 0.59±0.02). Densitometric analysis of amlodipine besylate and metoprolol succinate was carried out in the absorbance mode at 254 nm. Linear regression analysis data for the calibration plots showed good linear relationship with r(2) = 0.9990±0.0013 with respect to peak area in the concentration range 400-1400 ng per spot for amlodipine besylate and r(2) = 0.9993±0.0013 with respect to peak area in the concentration range 3800-13300 ng per spot for metoprolol succinate. The method was validated for precision, recovery and robustness. The limits of detection and quantitation were 39.99 and 121.20 ng per spot for amlodipine besylate and 234.31 and 710.03 ng per spot for metoprolol succinate, respectively. Statistical analysis proved that the method is selective, precise and accurate for the estimation of amlodipine and metoprolol.

Migration of intrauterine devices: radiologic findings and implications for patient care

Intrauterine devices (IUDs) are a commonly used form of contraception worldwide. However, migration of the IUD from its normal position in the uterine fundus is a frequently encountered complication, varying from uterine expulsion to displacement into the endometrial canal to uterine perforation. Different sites of IUD translocation vary in terms of their clinical significance and subsequent management, and the urgency of communicating IUD migration to the clinician is likewise variable. Expulsion or intrauterine displacement of the IUD leads to decreased contraceptive efficacy and should be clearly communicated, since it warrants IUD replacement to prevent unplanned pregnancy. Embedment of the IUD into the myometrium can usually be managed in the outpatient clinical setting but occasionally requires hysteroscopic removal. Complete uterine perforation, in which the IUD is partially or completely within the peritoneal cavity, requires surgical management, and timely and direct communication with the clinician is essential in such cases. Careful evaluation for intraabdominal complications is also important, since they may warrant urgent or emergent surgical intervention. The radiologist plays an important role in the diagnosis of IUD migration and should be familiar with its appearance at multiple imaging modalities.

Role of antisite disorder on preamorphization swelling in titanate pyrochlores

Ion irradiation experiments and atomistic simulations were used to demonstrate that irradiation-induced lattice swelling in a complex oxide, Lu2Ti2O7, is due initially to the formation of cation antisite defects. X-ray diffraction revealed that cation antisite formation correlates directly with lattice swelling and indicates that the volume per antisite pair is approximately 12  Å3. First principles calculations revealed that lattice swelling is best explained by cation antisite defects. Temperature accelerated dynamics simulations indicate that cation Frenkel defects are metastable and decay to form antisite defects.

[Sustainable production of bulk chemicals by application of "white biotechnology"]

Practically all organic chemicals and plastics are nowadays produced from crude oil and natural gas. However, it is possible to produce a wide range of bulk chemicals from renewable resources by application of biotechnology. This paper focuses on White Biotechnology, which makes use of bacteria (or yeasts) or enzymes for the conversion of the fermentable sugar to the target product. It is shown that White Biotechnology offers substantial savings of non-renewable energy use and greenhouse gas emissions for nearly all of the products studied. Under favorable boundary conditions up to two thirds (67%) of the current non-renewable energy use for the production of the selected chemicals can be saved by 2050 if substantial technological progress is made and if the use of lignocellulosic feedstocks is successfully developed. The analysis for Europe (E.U. 25 countries) shows that land requirements related to White Biotechnology chemicals are not likely to become a critical issue in the next few decades, especially considering the large unused and underutilized resources in Eastern Europe. Substantial macroeconomic savings can be achieved under favourable boundary conditions. In principle, natural bacteria and enzymes can be used for White Biotechnology but, according to many experts in the fields, Genetically Modified Organisms (GMO) will be necessary in order to achieve the high yields, concentrations and productivities that are required to reach economic viability. Safe containment and inactivation of GMOs after release is very important because not all possible implications caused by the interaction of recombinant genes with other populations can be foreseen. If adequate precautionary measures are taken, the risks related to the use of genetically modified organisms in White Biotechnology are manageable. We conclude that the core requirements to be fulfilled in order to make clear steps towards a bio-based chemical industry are substantial technological progress in the bioprocess step and in downstream processing, high prices for fossil fuels and low prices for fermentable sugar. We strongly recommend to develop an integrated White Biotechnology strategy taking into account these four core requirements and other important accompanying activities.

Producing bio-based bulk chemicals using industrial biotechnology saves energy and combats climate change

The production of bulk chemicals from biomass can make a significant contribution to solving two of the most urgent environmental problems: climate change and depletion of fossil energy. We analyzed current and future technology routes leading to 15 bulk chemicals using industrial biotechnology and calculated their CO2 emissions and fossil energy use. Savings of more than 100% in non-renewable energy use and greenhouse gas emissions are already possible with current state of the art biotechnology. Substantial further savings are possible for the future by improved fermentation and downstream processing. Worldwide CO2 savings in the range of 500-1000 million tons per year are possible using future technology. Industrial biotechnology hence offers excellent opportunities for mitigating greenhouse gas emissions and decreasing dependence on fossil energy sources and therefore has the potential to make inroads into the existing chemical industry.

Adenosine exerts multiple effects in dorsal horn neurones of the adult rat spinal cord

In the present study, we have examined the effects of adenosine and its analogues on the electrophysiological properties of dorsal horn neurones in the rat adult spinal cord. Adenosine and the A1 receptor agonist R-phenylisopropyl adenosine (RPIA) reversibly hyperpolarised these neurones via the generation of an outward current at -60 mV that was inhibited by pre-application of barium or Rp-adenosine 3', 5'-cyclic monophosphothioate triethylamine. In contrast, the A2a receptor agonist 2-[p-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680) had no effect on the resting membrane properties of these neurones. Stimulation of the dorsal root evoked non-NMDA receptor-mediated excitatory postsynaptic currents (EPSCs) at -60 mV that were completely abolished by 2,3-dihydroxy-6-nitro-7-sulophamoyl-benzo(F)quinoxalone (NBQX). Bath application of adenosine or RPIA reversibly inhibited these EPSCs in a concentration-dependent manner via a presynaptic action. In contrast, CGS21680 increased the amplitude of the EPSC in 20% of neurones tested and decreased the EPSC amplitude in 30% of neurones tested. It is concluded that adenosine exerts multiple effects upon the electrophysiological properties of dorsal horn neurones in the adult spinal cord via interaction with multiple receptors. These findings have important implications in the understanding of adenosine action in preclinical models of pain.

Smoking cessation in patients with chronic obstructive pulmonary disease: a double-blind, placebo-controlled, randomised trial

BACKGROUND

Tobacco smoking is associated with chronic obstructive pulmonary disease (COPD) in more than 80% of cases. Our aim was to investigate the effect of sustained-release bupropion (amfebutamone) (SR) in promoting abstinence from smoking in patients with COPD.

METHODS

In a double-blind, randomised, placebo-controlled trial 404 individuals with mild or moderate COPD who smoked 15 or more cigarettes per day, were assigned bupropion SR (150 mg twice daily) or placebo for 12 weeks. All patients received smoking cessation counselling. Study medication was taken for 1 week before patients attempted to stop smoking. The primary efficacy endpoint was the complete and continuous abstinence from smoking from the beginning of week 4 to the end of week 7. Participants were followed up at month 6. Analysis was by intention to treat.

FINDINGS

All patients were chronic smokers with a smoking history of about 51 pack-years. Continuous smoking abstinence rates from week 4 to 7 were significantly higher in participants receiving bupropion SR than in those receiving placebo (28% [57/204] vs 16% [32/200], p=0.003). Continuous abstinence rates from weeks 4 to 12 (18% [36/204] vs 10% [20/200]) and weeks 4 to 26 (16% [32/204] vs 9% [18/200]) were also higher in participants receiving bupropion SR than in those taking placebo (p<0.05). Furthermore, symptoms of tobacco craving and withdrawal were attenuated in those receiving bupropion SR. Seven individuals discontinued study medication because of adverse events.

INTERPRETATION

Bupropion SRis a well-tolerated and effective aid to smoking cessation in people with mild to moderate COPD.

Prognostic significance of periodic acid-Schiff-positive patterns in primary cutaneous melanoma

The patterns of periodic acid-Schiff (PAS) staining of extracellular matrix in histological sections of certain melanomas may be predictive of outcome. Recent in vitro and molecular genetic data suggest that the appearance of these patterns in both uveal and cutaneous melanoma is a function of aggressive tumor cells. We studied 96 patients with primary cutaneous melanomas treated at the University of Illinois at Chicago who were monitored for disease-free survival. Survival probabilities were determined by Kaplan-Meier estimates, and prognostic factors were evaluated by multivariate analysis. By univariate analysis, there was a significant decrease in disease-free survival among patients whose tumors contained parallel with cross-linking or network patterns (PXNs; P = 0.0070). Stepwise regression with Cox models that included the combinations of the PAS-positive patterns, tumor thickness, female gender, ulceration, and age yielded a model with thickness and the PAS-positive parallel with cross-linking or networks. Despite the relatively small sample size in this study, the detection of the PAS-positive parallel with cross-linking or networking in cutaneous melanoma was associated with a decrease in disease-free outcome. Additional studies of the prognostic significance of these patterns is warranted on larger data sets.

Properties of native P2X receptors in rat trigeminal mesencephalic nucleus neurones: lack of correlation with known, heterologously expressed P2X receptors

Trigeminal mesencephalic nucleus (MNV) neurones express functional P2X receptors. In order to determine the molecular identity of the P2X receptors in this nucleus we have used whole cell patch clamp recording of P2X receptor-mediated currents to determine the pharmacological properties of the receptors, and have compared them with those of cloned P2X receptor subunits. The purine nucleotides ATP (300 microM), ATP-gamma-S (30 microM) and alphabetameATP (300 microM) evoked inward currents in all MNV neurones whereas alphabetameADP (300 microM) did not. betagammame-L-ATP (300 microM) evoked only a small ( approximately 20 pA) current in 3 out of 6 MNV neurones. The P2X receptor antagonist TNP-ATP (10 nM-10 microM) and raised extracellular Ca(2+) (8 and 30 mM) reduced, but did not abolish, the current evoked by ATP-gamma-S. The current remaining in TNP-ATP was insensitive to blockade by raised Ca(2+). These properties suggest that MNV neurones do not express homomeric P2X(3), P2X(4) or P2X(6) receptors. Whilst the TNP-ATP-insensitive ATP-gamma-S-evoked current has many characteristics similar to both homomeric P2X(2) and P2X(5) receptors, its insensitivity to blockade by raised Ca(2+) is difficult to reconcile with the receptor being a P2X(2) or P2X(5) homomeric channel. More likely, the receptor is a heteromer that comprises either or both of these subunits. The TNP-ATP-sensitive component of the ATP-gamma-S-evoked current is dissimilar to known cloned homomeric or heteromeric P2X receptors.

Contributions of charged residues in a cytoplasmic linking region to Na channel gating

Na channels inactivate quickly after opening, and the very highly positively charged cytoplasmic linking region between homologous domains III and IV of the channel molecule acts as the inactivation gate. To test the hypothesis that the charged residues in the domain III to domain IV linker have a role in channel function, we measured currents through wild-type and two mutant skeletal muscle Na channels expressed in Xenopus oocytes, each lacking two or three charged residues in the inactivation gate. Microscopic current measures showed that removing charges hastened activation and inactivation. Macroscopic current measures showed that removing charges altered the voltage dependence of inactivation, suggesting less coupling of the inactivation and activation processes. Reduced intracellular ionic strength shifted the midpoint of equilibrium activation gating to a greater extent, and shifted the midpoint of equilibrium inactivation gating to a lesser extent in the mutant channels. The results allow the possibility that an electrostatic mechanism contributes to the role of charged residues in Na channel inactivation gating.

Heart rate variability in preterm brain-injured and very-low-birth-weight infants

Heart rate variability (HRV) reflects the complex interplay of the sympathetic and parasympathetic innervation of the heart. Developmental maturation of the fetus and newborn results in predictable alterations in the neural cardiac control of heart rate. Furthermore, patterns of HRV are closely correlated to clinical outcome in several pathologic situations. The first aim of this study was to characterize the maturational patterns of HRV in a group of developmentally at-risk newborns (those with severe hemorrhagic or ischemic brain injury and extremely immature, low-birth-weight infants). Secondly, we sought to determine whether a correlation exists between HRV and length of hospital stay, diagnosis of cerebral palsy, and neurodevelopmental test scores at 1-year corrected age. Time domain indices of HRV were computed longitudinally from 32 to 37 weeks of corrected gestational age in 19 very low birth weight, preterm infants. Among the 19 infants studied, 7 infants had no evidence of brain injury, 7 infants had periventricular leukomalacia (PVL), 3 infants had grade III/IV intraventricular hemorrhage (IVH), and 2 infants had both IVH and PVL. Neurologic injuries were documented using ultrasound and neurodevelopmental progress was followed through 1 year of corrected gestational age. A multivariate repeated measures analysis was performed to determine the relationship between the type of perinatal brain injury and neurodevelopmental status at 1 year of corrected gestational age. The type of perinatal brain injury was highly correlated to specific patterns of HRV with multivariate regression models producing adjusted r(2) values ranging from 0.63 to 0.99. The type of perinatal brain injury was highly correlated to the developmental outcome measures (p < 0.0000) with PVL patients having the lowest neurodevelopmental scores, IVH patients having the highest scores, and noninjured infants having midrange, grossly normal values. Using ANOVA, HRV was correlated to outcome, but individual comparisons revealed statistical significance only for the noninjured group (p < 0.04). However, multivariate models, which characterized outcome within each brain injury group, were highly significant (adjusted r (2) ranged from 0.23 to 0.89). In summary, the type of perinatal brain injury determined the pattern of HRV and HRV was highly correlated to length of hospital stay and neurodevelopmental function assessed at 1 year of corrected gestational age.

A ligand of peroxisome proliferator-activated receptor gamma, retinoids, and prevention of preneoplastic mammary lesions

BACKGROUND

Chemoprevention of breast cancer is an active area of investigation. Recent in vivo and in vitro studies have shown that thiazolidinediones (e.g., troglitazone) and retinoids are able to inhibit the growth of breast cancer cells. Troglitazone mediates its action via peroxisome proliferator-activated receptor gamma (PPARgamma). We evaluated the ability of troglitazone, alone or in combination with retinoids, to prevent the induction of preneoplastic lesions by 7,12-dimethylbenz[a]anthracene (DMBA) in a mouse mammary gland organ culture model.

METHODS

Mammary glands of BALB/c mice were treated with DMBA (2 microg/mL) to induce preneoplastic lesions in organ culture. Effects of troglitazone, all-trans-retinoic acid (retinoic acid; ligand for retinoic acid receptor [RAR] alpha), and LG10068 (ligand for retinoid X receptors [RXRs]), singly or in combination, on the development of lesions were evaluated. Expression of retinoid receptors (RARalpha and RXRalpha) and PPARgamma was determined by western blot analysis. Statistical significance was determined by generalized chi-squared analysis using the GENCAT software program and Bonferroni correction. All P values are two-sided.

RESULTS

Troglitazone (at 10(-5) M) or retinoic acid (at 10(-6) M) markedly inhibited the development of mammary lesions (both P values <.05); however, together they did not enhance the effectiveness of the other. In contrast, LG10068 (at 10(-7) M or 10(-8) M) alone had very little ability to inhibit development of these lesions, but a combination of LG10068 (at 10(-8) M) and troglitazone (at 10(-5) M or 10(-6) M) almost completely inhibited (by 85% and 100%, respectively; both P values <. 05) the development of mammary lesions. The expression of PPARgamma and RXRalpha remained unchanged with the various treatments, whereas the expression of RARalpha was substantially reduced after treatment with the combination of retinoic acid and troglitazone.

CONCLUSIONS

To our knowledge, this is the first report showing the possibility of a PPARgamma ligand having chemopreventive activity. Furthermore, an RXR-selective retinoid, LG10068, appears to enhance this activity.

Cyanide increases reduction but decreases sequestration of methylene blue by endothelial cells

The mechanisms of endothelial cell transplasma membrane electron transport (TMET) have not been completely identified. Redox probes such as methylene blue (MB) can be useful tools, but the complexity of their disposition upon exposure to the cells can hinder interpretation. For example, MB is reduced on the cell surface by TMET, but after entering the cell in reduced form, it is reoxidized and sequestered within the cell. We developed a method to separately quantify the reduction and reoxidation rates such that it can be determined whether a metabolic inhibitor such as cyanide affects the reduction or oxidation process. MB was introduced at the inlet to a column filled with endothelial cell covered beads either as a short 12 s injection (bolus) or a long 45 min infusion (pulse), and its effluent concentration was measured as a function of time. The cells extracted 56% of the MB from the bolus, but only 41% during the pulse steady state. In the presence of cyanide, these extractions increased to 70% and decreased to 4%, respectively. Mathematical model results support the interpretation that these paradoxical effects on bolus and pulse extractions reflect the differential effects of cyanide on extracellular reduction and intracellular oxidation, i.e., cyanide increased the reduction rate from 7.3 to 13.0 cm s-1 X 10(-5) and decreased the oxidation rate from 1.09 to 0.02 cm s-1 X 10(-3). Cyanide also increased intracellular NADH by almost eight times, suggesting that TMET is sensitive to the cell redox status, i.e., NADH is a direct or indirect electron source. The cyanide-induced decrease in sequestration indicates a cyanide-sensitive intracellular oxidation mechanism. The results also demonstrate the potential utility of this approach for further evaluation of these endothelial redox mechanisms.

Protein kinase C co-expression and the effects of halothane on rat skeletal muscle sodium channels

1. Voltage-gated Na channels, which are potential targets for general anaesthetics, are substrates for PKC, which phosphorylates a conserved site in the channel inactivation gate. We investigated the idea that PKC modulates the effect of volatile anaesthetics on Na channels via phosphorylation of this inactivation gate site. 2. Na currents through rat skeletal muscle Na channel alpha-subunits expressed in Xenopus oocytes were measured by two-microelectrode voltage clamp in the presence of the volatile anaesthetic agent halothane (2-bromo-2-chloro-1,1,1-trifluroethane). PKC activity was modulated by co-expression of a constitutively active PKC alpha-isozyme. 3. Halothane (0.4 mM) had no effect on Na currents. With co-expression of PKC, however, halothane dose-dependently enhanced the rate of Na current decay and caused a small, but statistically significant reduction in Na current amplitude. 4. The enhancement of Na current decay was absent in a Na channel mutant in which the inactivation gate phosphorylation site was disabled. Effects of halothane on amplitude were independent of this mutation. 5. Co-expression of a PKC alpha-isozyme permits an effect of halothane to hasten current decay and reduce current amplitude, at least in part through interaction with the inactivation gate phosphorylation site. We speculate that the interaction between halothane and Na channels is direct, and facilitated by PKC activity and by phosphorylation of a site in the channel inactivation gate.

Modulation of Xenopus oocyte-expressed phospholemman-induced ion currents by co-expression of protein kinases

Phospholemman (PLM), the major sarcolemmal substrate for phosphorylation by cAMP-dependent kinase (PKA) protein kinase C (PKC) and NIMA kinase in muscle, induces hyperpolarization-activated anion currents in Xenopus oocytes, most probably by enhancing endogenous oocyte currents. PLM peptides from the cytoplasmic tail are phosphorylated by PKA at S68, by NIMA kinase at S63, and by PKC at both S63 and S68. We have confirmed the phosphorylation sites in the intact protein, and we have investigated the role of phosphorylation in the regulatory activity of PLM using oocyte expression experiments. We found: (1) the cytoplasmic domain is not essential for inducing currents in oocytes; (2) co-expression of PKA increased the amplitude of oocyte currents and the amount of PLM in the oocyte membrane largely, but not exclusively, through phosphorylation of S68; (3) co-expression of PKA had no effect on a PLM mutant in which all putative phosphorylation sites had been inactivated by serine to alanine mutation (SSST 62, 63, 68, 69 AAAA); (4) co-expression of PKC had no effect in this system; (5) co-expression of NIMA kinase increased current amplitude and membrane protein level, but did not require PLM phosphorylation. These findings point to a role for phosphorylation in the function of PLM.

Coeliac disease in adults: variations on a theme

In childhood, coeliac disease (gluten enteropathy) tends to show itself with failure to thrive and growth retardation; in adult life with malabsorption syndromes. We report six cases in adults who presented atypically, with features including clotting disorder, hypoglycaemia, weight loss, anaemia and angina pectoris, all of which responded to gluten withdrawal.

Characterization of [3H]-heparin binding in human vascular smooth muscle cells and its relationship to the inhibition of DNA synthesis

1. The glycosaminoglycan heparin inhibits vascular smooth muscle cell (VSMC) proliferation and migration, but the mechanism of its antiproliferative action remains unclear. Heparin has been reported to bind to high affinity cell surface sites on animal VSMC before undergoing receptor mediated endocytosis resulting in signal transduction into the cytoplasm and modulation of genes involved in proliferation. In this study, we have characterized the binding of [3H]-heparin to human saphenous vein-derived VSMC and examined whether there is any relationship between the affinity of [3H]-heparin binding and the inhibitory effect of heparin and its structural analogues on DNA synthesis. 2. At 4 degrees C [3H]-heparin binding to human VSMC occurred in a specific, time and concentration-dependent manner and was not influenced by the removal of calcium ions. Binding of the ligand appeared to occur to the cell surface and was both saturable and reversible. Kinetic and steady state data indicated a single class of binding sites. 3. The pharmacology of [3H]-heparin binding was examined in displacement studies using unlabelled heparin and structural analogues. A comparison of the rank potencies of heparin, heparan sulphate fraction II, low molecular weight heparin and trehalose octasulphate showed that there was a marked discrepancy between their estimated affinities in the binding assays and their effect on DNA synthesis. 4. In summary, we have characterized the heparin binding site on human saphenous vein-derived VSMC. Our findings suggest that the action of heparin and its analogues on DNA synthesis does not simply reflect an interaction with the cell-associated heparin binding site defined in these studies, but may also be determined by the internalization and metabolism of the glycosaminoglycan(s).

Effects of Palmitoyl Carnitine on Perfused Heart and Papillary Muscle

BACKGROUND: Palmitoyl carnitine accumulation during ischemia causes profound electrophysiological changes, resulting in arrhythmias. We studied the electrophysiological and contractile effects of palmitoyl carnitine. METHODS AND RESULTS: Extracellular recordings made by using the endocardial unipolar paced evoked response (PER) in isolated perfused rabbit hearts were compared with action potentials (AP) recorded from septal artery perfused rabbit papillary muscle. Left ventricular pressure was monitored in isolated hearts. In perfused hearts palmitoyl carnitine (30 µmol/L, 30 minutes) significantly (P <.001) increased the latency of activation (St-R interval) by 58% +/- 8% and reduced repolarization time (R-E interval) by 39% +/- 4%. PER duration (St-E interval), was reduced by 30% +/- 3%. Palmitoyl carnitine (30 µmol/L) significantly (P <.001) decreased resting membrane potential (19 +/- 2 mV) of AP, reduced peak amplitude (33.5 +/- 8 mV) and rate of rise of phase 0 (41 +/- 8 V/s). Significant reductions (P <.001) in the action potential duration 50% (129.4 +/- 28 ms) and 90% (139.8 +/- 32 ms) were also observed. An initial positive inotropic effect, which declined as irreversible contracture developed, was also observed. Verapamil (1 µmol/L), nifedipine (1 µmol/L), and caffeine (10 mmol/L) failed to abolish the positive inotropy. CONCLUSIONS: We suggest that palmitoyl carnitine disrupts intracellular calcium homeostasis leading to disturbances in electrical and contractile activity. Its accumulation during myocardial ischemia could contribute to calcium overloading and initiate lethal arrhythmias.

Gene therapy with HSP72 is neuroprotective in rat models of stroke and epilepsy

Brain areas damaged by stroke and seizures express high levels of the 72-kd heat shock protein (HSP72). Whether HSP72 represents merely a marker of stress or plays a role in improving neuron survival in these cases has been debated. Some induced tolerance experiments have provided correlative evidence for a neuroprotective effect, and others have documented neuroprotection in the absence of HSP72 synthesis. We report that gene transfer therapy with defective herpes simplex virus vectors overexpressing hsp72 improves neuron survival against focal cerebral ischemia and systemic kainic acid administration. HSP72 overexpression improved striatal neuron survival from 62.3 to 95.4% in rats subjected to 1 hour of middle cerebral artery occlusion, and improved survival of hippocampal dentate gyrus neurons after systemic kainic acid administration, from 21.9 to 64.4%. We conclude that HSP72 may participate in processes that enhance neuron survival during transient focal cerebral ischemia and excitotoxin-induced seizures.

Familial slipped capital femoral epiphysis: a report and considerations in management

BACKGROUND

Familial inheritance of slipped capital femoral epiphysis (SCFE) is known. It has not been described in non-identical twins. A family where the mother and three of five siblings developed SCFE were investigated and managed.

METHODS

Anthropometric measurement consisted of height-weight ratios. Serum sex hormone levels and bone Gla Protein was measured. Bone mineral densities were evaluated.

RESULTS

The affected siblings had higher bodyweight percentiles. Other investigations were within normal limits.

CONCLUSION

The unfavourable height-to-weight ratio was one of the mainstays in developing a management protocol for all siblings. The management protocol developed for the family is discussed.

Plasma c-erbB-2 levels in breast cancer patients: prognostic significance in predicting response to chemotherapy

PURPOSE

To determine the significance of plasma c-erbB-2 levels to assess the extent of disease spread and to predict the response to chemotherapy in node-positive breast cancer patients.

METHODS

We determined plasma levels of c-erbB-2 in 79 stages II and III breast cancer patients who received cyclophosphamide, methotrexate, and flourouracil (CMF)/cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) chemotherapy. All patients had a minimum follow-up of greater than 60 months or until disease recurrence. Plasma samples were obtained before and after chemotherapy. Plasma c-erbB-2 levels were quantified by enzyme-linked immunoassay. c-erbB-2 levels were analyzed in relation to the patients' axillary lymph node status, menopausal status, disease status, disease-free survival (DFS), and steroid receptor status of tumor.

RESULTS

Plasma c-erbB-2 levels varied widely in breast cancer patients. In general, when all patients were included in the analyses, plasma c-erbB-2 levels before chemotherapy correlated significantly with the number of positive axillary lymph nodes and with postchemotherapy c-erbB-2 levels. No association was observed between pre- or postchemotherapy c-erbB-2 levels and other variables (patients' age at diagnosis, receptor status of the tumor, or disease status). The prognostic significance of different factors (ie, nodal status [one to three v > three positive nodes], menopausal status [pre- v postmenopausal women], estrogen receptor [ER] status [ER+ v ER-], and pre- and postchemotherapy c-erbB-2 levels) in predicting DFS was determined in all study patients. Among the variables examined, nodal status was the strongest predictor of DFS in these patients. The second most significant prognostic marker was postchemotherapy c-erbB-2 level. Prechemotherapy c-erbB-2 levels showed prognostic significance for DFS in a subset of breast cancer patients (ie, patients with > three positive nodes). Patients with greater than three positive lymph nodes and those with greater than 100 fmol/mL of plasma c-erbB-2 levels before therapy had significantly shorter DFS than did those patients with 100 fmol/mL or less c-erbB-2 levels.

CONCLUSION

In breast cancer patients, determination of c-erbB-2 levels before therapy is an important biomarker to assess the extent of disease spread in the lymph nodes. Postchemotherapy c-erbB-2 levels are also a prognostic indicator for DFS in patients who receive chemotherapy. Finally, in a subgroup of patients with greater than three positive nodes, prechemotherapy c-erbB-2 levels are a prognostic marker for response of patients to standard chemotherapy.

Vein graft stenosis and the heparin responsiveness of human vascular smooth muscle cells

BACKGROUND

Vascular smooth muscle cell (VMSC) proliferation is an essential component of myointimal hyperplasia, which is implicated in the failure of 30% to 50% of vascular interventions, such as coronary angioplasty and peripheral vein grafting. We have shown that cells derived from stenotic lesions in infrainguinal vein grafts were significantly more resistant than controls to growth inhibition by heparin.

METHODS AND RESULTS

In a prospective study, we correlated antiproliferative responses to heparin in vitro with graft patency after 1 year. Sixty-two patients with infrainguinal vein grafts were entered into a graft surveillance program for > or = 1 year. At operation, saphenous vein segments were explanted for VSMC culture. Cell proliferation in response to fetal calf serum was later determined in the presence and absence of heparin. In 35 cell cultures, including 13 from the above-mentioned patients, [3H]heparin binding was also estimated. VSMCs from patients with patent grafts were significantly more sensitive to growth inhibition by heparin than cells from patients with stenoses (median, 54% versus 20.9%, P<0.001), and [3H]heparin binding was strongly correlated with inhibition of proliferation (r=0.81).

CONCLUSIONS

Responsiveness to heparin in cultured VSMCs is a strong predictor of outcome for infrainguinal vein grafts, and reduced sensitivity to heparin is correlated with decreased heparin binding. Relative resistance to the antiproliferative action of heparin may be a marker for aberrant regulation of VSMC growth.

Low-dose heparin appears safe and can eliminate protamine use for carotid endarterectomy

OBJECTIVE

To determine the morbidity associated with carotid endarterectomy (CEA) when low doses of heparin (30 U/kg) are used for anticoagulation. This technique eliminates the need for protamine and its potentially deleterious effects on some patients.

DESIGN

A retrospective chart review.

SETTING

A large academic medical center.

PARTICIPANTS

The records of 420 consecutive CEAs in 337 patients (83 bilateral procedures).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The amount of heparin used was less than that used in most reported studies. Eighty-two percent of patients received only 2,000 U of heparin for their entire operation (range, 500 to 3,000 U). Complication rates were low. Neurologic complications included a 0.95% incidence of nonfatal stroke and a 2.1% incidence of transient neurologic deficits that resolved in the first day. There was no mortality. The wounds were described in the postoperative period as dry (96%), swollen (3%), or bloody (1%). No patients received protamine.

CONCLUSION

The use of 5 to 10,000 U of heparin will provide anticoagulation for more than an hour. In CEA surgery, anticoagulation for this duration is often unnecessary. A smaller dose of heparin (30 U/kg) can provide adequate anticoagulation for this procedure while eliminating the potentially deleterious effects of protamine use. No additional morbidity was attributed to this technique.

Ascorbate-mediated transplasma membrane electron transport in pulmonary arterial endothelial cells

Pulmonary endothelial cells are capable of reducing certain electron acceptors at the luminal plasma membrane surface. Motivation for studying this phenomenon comes in part from the expectation that it may be important both as an endothelial antioxidant defense mechanism and in redox cycling of toxic free radicals. Pulmonary arterial endothelial cells in culture reduce the oxidized forms of thiazine compounds that have been used as electron acceptor probes for studying the mechanisms of transplasma membrane electron transport. However, they reduce another commonly studied electron acceptor, ferricyanide, only very slowly by comparison. In the present study, we examined the influence of ascorbate [ascorbic acid (AA)] and dehydroascorbate [dehydroascorbic acid (DHAA)] on the ferricyanide and thiazine reductase activities of the bovine pulmonary arterial endothelial cell surface. The endothelial cells were grown on microcarrier beads so that the reduction of ferricyanide and methylene blue could be studied colorimetrically in spectrophotometer cuvettes and in flow-through cell columns. The ferricyanide reductase activity could be increased 80-fold by adding DHAA to the medium, with virtually no effect on methylene blue reduction. The DHAA effect persisted after the DHAA was removed from the medium. AA also stimulated the ferricyanide reductase activity but was less potent, and the relative potencies of AA and DHAA correlated with their relative rates of uptake by the cells. The results are consistent with the hypothesis that AA is an intracellular electron donor for an endothelial plasma membrane ferricyanide reductase and that the stimulatory effect of DHAA is the result of increasing intracellular AA. Adding sufficient DHAA to markedly increase extracellular ferricyanide reduction had little effect on the plasma membrane methylene blue reductase activity, suggesting that pulmonary arterial endothelial cells have at least two separate transplasma membrane electron transport systems.

Intravenous lidocaine speeds the return of bowel function, decreases postoperative pain, and shortens hospital stay in patients undergoing radical retropubic prostatectomy

Postoperative ileus is a concern among surgical patients. Epidural anesthesia and analgesia with local anesthetics can decrease the duration of ileus. Significant systemic absorption of local anesthesia occurs during epidural use. In this study, we examined whether many of the beneficial effects on bowel function seen with epidural lidocaine are also present when the drug is given parenterally. Forty patients undergoing radical retropubic prostatectomy were studied with one half of the patients receiving a lidocaine bolus (1.5 mg/kg) and infusion (3 mg/min, unless weight <70 kg, then 2 mg/min); the other half received a saline infusion. A blind observer recorded the patient's daily pain score, the time the patient first experienced flatulence and had the first bowel movement, and the total use of analgesics. Lidocaine-treated patients first experienced flatulence in a significantly shorter time (P < 0.01) than control patients. Lidocaine patients' hospital stay was also significantly shorter (P < 0.05); on average, they spent 1.1 fewer days in the hospital. I.V. lidocaine initiated before anesthesia and continued 1 h postoperatively significantly sped up the return of bowel function. Lidocaine patients were also more comfortable postoperatively. Many of the bowel function benefits attributed to epidural lidocaine are also present when the drug is administered parenterally. Additionally, the length of hospital stay was reduced in lidocaine-treated patients.

IMPLICATIONS

This study prospectively examined whether I.V. lidocaine could affect the return of bowel function after radical prostate surgery. Lidocaine-treated patients had shorter hospital stays, less pain, and faster return of bowel function. In this population, lidocaine infusion can be a useful adjunct in anesthetic management.

Thrombospondin-1 is a potent mitogen and chemoattractant for human vascular smooth muscle cells

Thrombospondin-1 (TSP-1) is a matricellular protein that is present in negligible amounts in normal human vasculature but occurs in significant amounts in diseased vessels. In this study, we examined the effect of TSP-1 on DNA synthesis, proliferation, and migration in human vascular smooth muscle cells grown from saphenous vein. TSP-1 (0.1 to 30 micrograms/mL) elicited a concentration-dependent increase in DNA synthesis under serum-free conditions. In combination with platelet-derived growth factor, TSP-1 induced a synergistic effect on DNA synthesis that was significantly higher than the additive effect of both agents. In proliferation assays, TSP-1 increased cell numbers by 50% relative to the serum-free controls over 14 days. In migration assays, conducted using modified Boyden chambers, TSP-1 (> or = 10 micrograms/mL) elicited marked chemotaxis to a degree equivalent to platelet-derived growth factor. The chemotactic response to TSP-1 (10 micrograms/mL) was abolished by the GRGDSP peptide but unaffected by the control GRGESP peptide, whereas neither peptide inhibited DNA synthesis stimulated by TSP-1. Inhibition of tyrosine kinase activity with genistein or tyrphostin A23 abolished DNA synthesis induced by TSP-1, and a neutralizing antibody to platelet-derived growth factor had no effect on DNA synthesis. Similarly, migration in response to TSP-1 was largely inhibited by these tyrosine kinase inhibitors. TSP-1 is a strong mitogen and chemoattractant for human vascular smooth muscle cells under serum-free conditions. The novel finding that TSP-1 is mitogenic for human cells contrasts with previous studies that have not shown any significant effect of TSP-1 itself on the growth of animal-derived smooth muscle cells. TSP-1 may play an important modulatory role in the local regulation of vascular smooth muscle function in vascular pathologies in humans.

Inhibition of proliferation by heparin and expression of p53 in cultured human vascular smooth muscle cells

Human vascular smooth muscle cells (HVSMC) cultured from restenotic lesions are resistant to inhibition of proliferation by heparin. We examined if altered expression of p53 protein might be related to this phenomenon. HVSMC were cultured from saphenous vein and p53 protein levels examined using immunocytochemistry, and by immunoprecipitation with antibodies specific for wild-type or mutant conformations followed by SDS PAGE and immunoblotting. Inhibition of proliferation by heparin was measured in 14-day growth assays. Elevated levels of p53 were found in five out of 41 HVSMC strains. The accumulated p53 protein was not precipitated by a mutant conformation-specific anti-p53 antibody in any of the five strains. In one of the five positive strains there was concomitant human cytomegaloviral infection. No significant difference was found between efficacy of heparin in the p53-positive and -negative strains. Furthermore heparin had no detectable effect on p53 protein levels. Although aberrant levels of p53 are detectable in a minority of HVSMC strains, these data do not support a role for altered p53 expression in resistance to the growth inhibitory effects of heparin in these cells.

Church-based education: an outreach program for African Americans with hypertension

The goals of this education outreach demonstration study were to prepare a cadre of registered nurses (RN) as Church Health Educators (CHE), and to test the efficacy of a hypertension (HBP) education and support program in African American (AA) churches for persons with HBP in managing blood pressure (BP). In this two-phase study, RNs were prepared as CHEs in phase 1 and a convenience sample of 97 subjects with HBP was taught by the CHEs in phase 2. The intervention's content included the bases of HBP and HBP management strategies, and was taught in eight 1-hour sessions. Using a pre-test-post-test design, data on knowledge, social support and BP were collected at baseline (pre), post-intervention (post1) and 3 months post-intervention (post2). Major findings include: (1) there was a significant increase in knowledge scores from pre to post1 and post2 (P < or = 0.0001; F = 95.08; df = 1.79); (2) education, age and number of years with HBP explained 49% of the variance associated with HBP knowledge; (3) systolic BP (SBP) and mean arterial BP (MAP) significantly decreased from pre to post1 and post2 (SBP-p < or = 0.0001, F = 18.35, df = 1.91; MAP-p < or = 0.0001, F = 17.80, df = 1.86); (4) DBP significantly decreased from pre to post1 only (p < or = 0.008, F = 17.48, df = 1.91); and (5) relationships were found between social support and DBP, and social support and MAP. Issues that emerged from this study with implications for outreach programming include recruitment and retention, randomization, selective sampling, intervention design and use of volunteers.

Effect of angiotension II on the expression of the early growth response gene c-fos and DNA synthesis in human vascular smooth muscle cells

OBJECTIVES

The aims of this study were to characterize the angiotensin II receptor subtype present on vascular smooth muscle cells from human saphenous vein and to assess the effect of angiotensin II on the expression of the early growth response gene c-fos and on DNA synthesis.

METHODS AND RESULTS

Using radioligand binding studies, we have defined the angiotensin II receptors present on these cells as being predominantly of the AT1 subtype. Angiotensin II increased peak intracellular calcium levels by 126 +/- 16 nmol/l (mean +/- SEM) in 17/49 cultures. Angiotensin II induced c-fos expression in a concentration-dependent manner only in cultures that exhibited an intracellular calcium transient in response to stimulation with angiotensin II. The induction of c-fos was inhibited by the selective AT1 antagonist losartan in accordance with the binding studies. Angiotensin II stimulated DNA synthesis with a maximal increase of 66.4% +/- 20.5% over serum-free levels at 1 nmol/l (mean +/- SEM, n = 6, P < 0.05). DNA synthesis declined with increasing angiotensin II concentration, falling to control values at 1 mumol/l, suggesting that a growth-inhibitory influence may counter-balance the stimulatory effect that is observed at lower concentrations.

CONCLUSION

Vascular smooth muscle cells from human saphenous vein possess predominantly AT1 receptors and in response to angiotensin II show an induction of c-fos and a modest increase in DNA synthesis.

Inhibition of human vascular smooth muscle cell proliferation by the novel multiple-action antihypertensive agent carvedilol

We examined the antiproliferative effect of the novel multiple-action antihypertensive agent carvedilol on human vascular smooth muscle cells (VSMC). Carvedilol inhibited the increase in cell number induced by foetal calf serum (FCS) in 86% (18 of 21) of human VSMC grown both from saphenous vein (17.6 +/- 3.5% inhibition, mean +/- SEM, n = 15) and restenotic lesions (31.4 +/- 5.5% inhibition, mean +/- SEM, n = 5). Carvedilol had a greater antiproliferative effect than other beta-adrenoceptor antagonists. In comparison with calcium channel blockers, carvedilol (10 microM) elicited a degree of growth inhibition similar to that of verapamil, but was less effective than the dihydropyridine amlodipine at equimolar concentrations. Although carvedilol had a greater antiproliferative effect on cells derived from restenotic lesions cells than on control saphenous vein cells, the difference was not statistically significant. In the present study, the antiproliferative effect of carvedilol on human VSMC in vitro occurred at concentrations higher than those in plasma. Although this may represent a limitation to the clinical efficacy of carvedilol against proliferation of VSMC associated with hypertension and atherosclerosis, the apparent relative selectivity of carvedilol for restenosis-derived cells is a promising line of investigation.

Mitochondrial calcium deposition in association with cyclosporine therapy and myocardial magnesium depletion: a serial histologic study in heart transplant recipients

Intramitochondrial calcification has been reported in heart transplant recipients treated with high-dose cyclosporine. Myocardial magnesium depletion is common in this group and, on the basis of extensive data from animal studies, would be expected to produce similar mitochondrial deposition of calcium. This prospective study investigated the occurrence of such calcification in biopsy specimens obtained serially in nine heart transplant recipients with simultaneous analysis of myocardial magnesium. During a mean follow-up of 32 weeks, 24 biopsy specimens were analyzed from nine patients. Mitochondrial calcium deposition was more marked in biopsy specimens from recipients with magnesium depletion (p < 0.025). Early toxic cyclosporine levels occurred in three recipients associated with a significant but reversible increase in mitochondrial calcification (p < 0.0001). Histologic rejection and use of calcium antagonists did not modify these findings. It is concluded that although cyclosporine toxicity does induce mitochondrial calcium deposition, such deposition can occur in the absence of toxicity should myocardial magnesium depletion be concurrent. Long-term follow-up will establish the clinical sequelae of such observations. However, when taken together with the results of this study, recent reports of attenuation of accelerated graft atherosclerosis by calcium antagonists may suggest that cyclosporine-induced myocardial magnesium depletion may have an etiologic role in this multifactorial process.

Patterns of physiologic and behavioral response of intermediate care preterm infants to intervention

PURPOSE

To determine the safety of a developmental intervention for use with preterm infants and feasibility of a time sampling procedure.

METHODOLOGY

An experimental design was used to test an intervention with clinically stable 33-34-week postconceptional age infants over a 4-day period. Repeated outcome measures included pulse rate, oxygen saturation levels, and infant behavioral state.

FINDINGS

The intervention resulted in significant differences in infant behavioral state with the experimental group achieving more alertness. Physiologic parameters remained within normal limits both during and after the intervention.

CONCLUSIONS

The protocol was found to be safe for implementation with clinically stable preterm infants. Behavioral state findings suggest the potential for the intervention to promote alertness. Results suggest that changes in oxygen saturation and pulse rate were dependent upon changes in behavioral state.