Strategic management to optimize response to cardiac resynchronization therapy registry

Background

Cardiac resynchronization therapy (CRT) is guideline-recommended for the treatment of symptomatic heart failure (HF) in patients (pts) with reduced LVEF and prolonged QRS. Clinical trials report Clinical Composite Score (CCS) response rates from 60 to 75%. However, patients with common comorbidities, such as atrial fibrillation, are often under-represented in clinical trials. The Strategic MAnagement to optimize response to cardiac Resynchronization Therapy (SMART) Registry (NCT03075215) was designed to examine outcomes in CRT patients in the real world.

Methods

The SMART Registry was a global, multicenter, prospective, clinical registry that enrolled subjects undergoing a de novo CRT-D implant or upgrade from pacemaker to CRT-D using a quadripolar LV lead. CCS was assessed at 12 months post-implant.

Results

For study design and CCS outcomes see Figure 1. CCS at 12 months showed that 58.8% of pts improved and 20.1% stabilized. Of the 21.1% of pts that worsened, 8.4% were due to death, 7.8% non-fatal heart failure event, and 5% worsening of NYHA or patient global assessment. Notably, this registry had a high prevalence of pts with NYHA I/II (51%), Non-LBBB (50%), AF (37%), diabetes (35%), and bradycardia (31%) at baseline. Age (>65), diabetes, ischemia, non-LBBB, atrial fibrillation (AF) and renal dysfunction correlated with worsened CCS outcomes. NYHA III/IV patients had significantly higher HF hospitalization (HFH) rates than NYHA I/II (P-value <0.001) (Figure 2a) and patients with AF had higher HFH rates than those without (P-value <0.001) (Figure 2b). Similar effects of NYHA score and AF were seen on mortality. The use of ACE/ARB, or ARNI, and MRA correlated with better outcomes, whereas diuretics and anticoagulants correlated with poorer outcomes.

Conclusions

In this large registry, clinical outcomes across important sub-populations are in line with expectations, with older age, ischemia, renal dysfunction, AF, non-LBBB, and diabetes associated with a lower likelihood of response to CRT. By including these patients, this study provides a clearer picture of the effectiveness of CRT in the real world. Future studies should examine optimization approaches to facilitate CRT effectiveness in these under studied patient populations.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This registry was funded by Boston Scientific (BSC)

916The impact of anesthesia choice on subcutaneous implantable cardioverter defibrillator outcomes: acute and one year results from the post approval study

Funding Acknowledgements

This study was financially supported by Boston Scientific

The influence of anesthesia technique on the outcomes of subcutaneous implantable cardioverter defibrillator (SICD) implantation has not been prospectively evaluated.

The aim of the present analysis was to characterize the effect of anesthesia choice acutely and over a year follow-up in the large "real-world" cohort of the SICD Post Approval Study (SICD-PAS).

Patients received either general anesthesia (GA), conscious sedation (CS), or monitored anesthesia care (MAC) at the implanting physicians" discretion.  Acute results and complications over one year were compared between GA, CS and MAC.

1,631 patients were studied.  64.3% received GA , 29.2% received CS and 6.6% received MAC.  Procedure times were shortest for MAC versus GA and CS (Table 1).  Cross-over from CS and MAC to GA occurred in 2.9% and 1.9% of procedures, respectively.  The mean left ventricular ejection fraction (LVEF) was lower in the MAC cohort compared with GA and CS.  GA patients were less often discharged the same day than CS and MAC.  Patients who had GA were more likely to have had intra-operative DFT testing, while successful DFT testing at implant did not differ among groups (Table 1).  At one year, freedom from total complications did not differ between groups (93.3% for GA, 92.9% for CS and 87.8% for MAC, p = 0.095) nor did freedom from inappropriate shocks (94% for GA, 94.2% for CS, 88.9% for MAC, p = 0.138) nor appropriate shocks (95.8% for GA, 95% for CS, 95% for MAC, p = 0.747).

All three anesthesia techniques had similar acute and one year outcomes but, despite having worse LVEF, patients who received MAC had shorter procedure times and infrequently required conversion to GA.  GA was associated with higher rates of next day patient discharge.  These results suggest that MAC may be preferred for the majority of patients. This observation should be confirmed with prospective trials.

Table 1:Characteristics and Outcomes Parameter Conscious Sedation General Anesthesia Monitored Anesthesia Care P value Gender[%(N/Total)] Male 68.1 (324/476) 69.3 (726/1048) 66.4 (71/107) 0.77 Age (years) mean ± SD 54 ± 15 53 ± 15 54 ± 13 0.61 Body Mass Index mean ± SD 30 ± 7 30 ± 8 29 ± 6 0.41 Creatinine (mg/dL) mean ± SD 2 ± 2 2 ± 4 2 ± 2 0.43 LVEF (%) mean ± SD 33 ± 15 32 ± 15 26 ± 9 <0.001 Procedure Time (min) mean ± SD 85 ± 42 75 ± 33 65 ± 30 <0.001 Same Day Discharge % 70.3% 64.3% 72.6% 0.03 DFT Attempted % 84% 89.1% 81.3% 0.004 Successful DFT % 98.7% 98.6% 98.8% 0.97

Occupational stress, job characteristics, coping, and the mental health of nurses

OBJECTIVES

 This study investigated the relationships between job characteristics and coping in predicting levels of anxiety and depression in nurses. The study was based on current theories of occupational stress, and predictors included job demands, social support, decision authority and skill discretion control, effort, over-commitment, rewards, and ways of coping. It was predicted that job demands, extrinsic effort, over-commitment, and negative coping behaviours would be positively associated with depression and anxiety, and social support, rewards, decision authority, skill discretion control, and positive coping would be negatively associated with depression and anxiety.

METHODS

 Participants were 870 nurses, who responded to a bulk mail sent randomly to 4,000 nurses from the south of England.

RESULTS

 The results showed that job demands, extrinsic effort, and over-commitment were associated with higher levels of anxiety and depression. Social support, rewards, and skill discretion were negatively associated with mental health problems. Few interactions were found between the variables. Coping behaviours significantly added to the explanation of variance in anxiety and depression outcomes, over and above the use of demand-control-support, and effort-reward factors alone.

CONCLUSION

 The results from the study demonstrated the importance of coping factors in work-stress research, in accordance with the multi-factorial premise of transactional stress models. It is argued that multi-factor research is needed to help develop effective organizational interventions.

Muscarinic type 2 receptors in the lateral dorsal tegmental area modulate cocaine and food seeking behavior in rats

The cholinergic input from the lateral dorsal tegmental area (LDTg) modulates the dopamine cells of the ventral tegmental area (VTA) and plays an important role in cocaine taking. Specific pharmacological agents that block or stimulate muscarinic receptors in the LDTg change acetylcholine (ACh) levels in the VTA. Furthermore, manipulations of cholinergic input in the VTA can change cocaine taking. In the current study, the ACh output from the LDTg was attenuated by treatment with the selective muscarinic type 2 (M2) autoreceptor agonist oxotremorine.sesquifumarate (OxoSQ). We hypothesized that OxoSQ would reduce the motivation of rats to self-administer both natural and drug rewards. Animals were tested on progressive ratio (PR) schedules of reinforcement for food pellets and cocaine. On test days, animals on food and on cocaine schedules were bilaterally microinjected prior to the test. Rats received either LDTg OxoSQ infusions or LDTg artificial cerebrospinal fluid (aCSF) infusions in a within-subjects design. In addition, infusions were delivered into a dorsal brain area above the LDTg as an anatomical control region. OxoSQ microinjection in the LDTg, compared to aCSF, significantly reduced both the number of self-administered pellets and cocaine infusions during the initial half of the session; this reduction was dose-dependent. OxoSQ microinjections into the area just dorsal to the LDTg had no significant effect on self-administration of food pellets or cocaine. Animals were also tested in locomotor activity chambers for motor effects following the above microinjections. Locomotor activity was mildly increased by OxoSQ microinjection into the LDTg during the initial half of the session. Overall, these data suggest that LDTg cholinergic neurons play an important role in modifying the reinforcing value of natural and drug rewards. These effects cannot be attributed to significant alterations of locomotor behavior and are likely accomplished through LDTg muscarinic autoreceptors.

Urocortin 1 microinjection into the mouse lateral septum regulates the acquisition and expression of alcohol consumption

Previous studies using genetic and lesion approaches have shown that the neuropeptide urocortin 1 (Ucn1) is involved in regulating alcohol consumption. Ucn1 is a corticotropin releasing factor (CRF) -like peptide that binds CRF1 and CRF2 receptors. Perioculomotor urocortin-containing neurons (pIIIu), also known as the non-preganglionic Edinger-Westphal nucleus, are the major source of Ucn1 in the brain and are known to innervate the lateral septum. Thus, the present study tested whether Ucn1 could regulate alcohol consumption through the lateral septum. In a series of experiments Ucn1 or CRF was bilaterally injected at various doses into the lateral septum of male C57BL/6J mice. Consumption of 20% volume/volume ethanol or water was tested immediately after the injections using a modification of a 2-h limited access sweetener-free "drinking-in-the-dark" procedure. Ucn1 significantly suppressed ethanol consumption when administered prior to the third ethanol drinking session (the expression phase of ethanol drinking) at doses as low as 6 pmol. Ethanol intake was differentially sensitive to Ucn1, as equivalent doses of this peptide did not suppress water consumption. In contrast, CRF suppressed both ethanol and water intake at 40 and 60 pmol, but not at lower doses. Repeated administration of Ucn1 during the acquisition of alcohol consumption showed that 40 pmol (but not 2 or 0.1 pmol) significantly attenuated ethanol intake. Repeated administration of Ucn1 also resulted in a decrease of ethanol intake in sham-injected animals, a finding suggesting that the suppressive effect of Ucn1 on ethanol intake can be conditioned. Taken together, these studies confirm the importance of lateral septum innervation by Ucn1 in the regulation of alcohol consumption.

Differentiation of parkinsonian syndromes according to differences in executive functions

Groups of patients with Parkinson's disease (PD), striatonigral degeneration-type multiple system atrophy (MSA) or progressive supranuclear palsy (PSP) with motor disability stages II and III according to Hoehn and Yahr, and a healthy control group were compared using neuropsychological tests of executive functions. The results indicate that all three patient groups were impaired in the tests of executive functions. In comparison with healthy subjects, the three patient groups showed impaired performance regarding verbal fluency, problem solving and verbal and figural working memory. Patients with PD differed significantly from healthy subjects in a test of verbal recency, while patients with MSA or PSP were unimpaired. The comparison of patient groups revealed no differences between PD and MSA patients. However, patients with PSP showed greater impairment in both phonemic and semantic fluency than patients with PD or MSA. Using discriminant function analysis, it was found that variables derived from four verbal fluency tasks (simple and alternate semantic and phonemic fluency) discriminated among the three patient groups at a level significantly exceeding chance. Over 90% of patients with PSP were correctly classified. Patients with PD and MSA were correctly classified in over 70% of cases. These results suggest that verbal fluency tasks may be sensitive measures in the differential diagnosis of PD, MSA and PSP.

Synthesis of acetylcholine by lung cancer

The role of autocrine growth factors in the stimulation of lung cancer growth is well established. Nicotine is an agonist for acetylcholine receptors and stimulates lung cancer growth. This suggests that if lung cancers synthesize acetylcholine (ACh), then ACh may be an autocrine growth factor for lung cancer. Analysis of normal lung demonstrated that the cells of origin of lung cancers express the proteins necessary for non-neuronal ACh storage and synthesis. Analysis of mRNA from squamous cell lung carcinoma, small cell lung carcinoma (SCLC) and adenocarcinoma showed synthesis of choline acetyltransferase (ChAT) and nicotinic receptors. Immunohistochemical analysis of a retrospective series of SCLC and adenocarcinomas showed that more than 50% of the lung cancers screened expressed ChAT and nicotinic receptors. To study the effect of endogenous ACh synthesis on growth, SCLC cell lines were studied. SCLC cell lines were found to express ChAT mRNA and to secrete ACh into the medium as measured by HPLC separation and enzymatically-coupled electrochemical detection. The SCLC cell line NCI-H82 synthesized highest levels of ACh. Showing that the endogenously synthesized ACh interacted with its receptors to stimulate cell growth, addition of muscarinic and nicotinic antagonists slowed H82 cell proliferation. These findings demonstrate that lung cancer cell lines synthesize and secrete ACh to act as an autocrine growth factor. The existence of a cholinergic autocrine loop in lung cancer provides a basis for understanding the effects of nicotine in cigarette smoke on lung cancer growth and provides a new pathway to investigate for potential therapeutic approaches to lung cancer.

Far-field responses to stimulation of the cochlear nucleus by microsurgically placed penetrating and surface electrodes in the cat

OBJECT

A new generation of penetrating electrodes for auditory brainstem implants is on the verge of being introduced into clinical practice. This study was designed to compare electrically evoked auditory brainstem responses (EABRs) to stimulation of the cochlear nucleus (CN) by microsurgically implanted surface electrodes and insertion electrodes (INSELs) with stimulation areas of identical size.

METHODS

Via a lateral suboccipital approach, arrays of surface and penetrating microelectrodes with geometric stimulation areas measuring 4,417 microm2 (diameter 75 microm) were placed over and inserted into the CN in 10 adult cats. After recording the auditory brainstem response (ABR) at the mastoid process, the CN, and the level of the inferior colliculus, EABRs to stimulation of the CN were recorded using biphasic, charge-balanced stimuli with phase durations of 80 microsec, 160 microsec, and 240 microsec at a repetition rate of 22.3 Hz. Waveform, threshold, maximum amplitude, and the dynamic range of the responses were compared for surface and penetrating electrodes. The EABR waveforms that appeared for both types of stimulation resembled each other closely. The mean impedance was slightly lower (30 +/- 3.4 kohm compared with 31.7 +/- 4.5 kohm, at 10 kHz), but the mean EABR threshold was significantly higher (51.8 microA compared with 40.5 microA, t = 3.5, p = 0.002) for surface electrode arrays as opposed to penetrating electrode arrays. Due to lower saturation levels of the INSEL array, dynamic ranges were almost identical between the two types of stimulation. Sectioning of the eighth cranial nerve did not abolish EABRs.

CONCLUSIONS

Microsurgical insertion of electrodes into the CN complex may be guided and monitored using techniques similar to those applied for implantation of surface electrodes. Lower thresholds and almost equivalent dynamic ranges indicate that a more direct access to secondary auditory neurons is achieved using penetrating electrodes.

Induction of mammary epithelial cell differentiation and inhibition of dimethylbenz(A)anthracene-induced mammary tumour by co-administration of a pure antiestrogen ICI 182,780 and testosterone enanthate

Epidemiological studies have shown that early first pregnancy is associated with a life-long reduction in breast cancer risk. The terminal differentiation associated with pregnancy and lactation has been proposed as a mechanism underlying the protective effect of pregnancy. We report that treatment of rats with ICI 182,780 (ICI) caused a marked reduction in epithelial cells and Ki-67 labelling index as compared to controls and testosterone enanthate-treated (TE) mammary glands. TE increased the Ki-67 labelling index, stimulated lobuloalveolar and ductal growth, as well as the secretory activity of acinar cells. Co-administration of TE and ICI resulted in a reduction in Ki-67 labelling index. Mammary epithelial cells became differentiated, resembling that observed at the end of pregnancy and during lactation as indicated by marked increase in secretory activity, lipid accumulation and presence of basal nuclei. The expression of differentiation markers such as whey acidic protein, mammary derived growth inhibitor, alpha-casein and beta-casein was detected only in TE plus ICI treated mammary tissues. Unlike TE, ICI caused a significant reduction in DMBA-induced tumour incidence, number of tumour bearing and tumour size. Tumour incidence was reduced to 8% when both ICI and TE were co-administered. Our data provide the novel molecular interactions between the estrogen and androgen in regulation of mammary growth and differentiation. These observations may give insight into novel actions of ICI and TE on breast differentiation and protection against carcinogenesis which may be useful in designing novel strategies for cancer prevention and/or treatment based on maximizing mammary epithelial cell differentiation.

[Anterior interosseous nerve syndrome as differential diagnosis of closed isolated flexor tendon lesion]

Lesions of the anterior interosseus nerve can result in a variety of clinical manifestations, depending on location and degree of axonal damage. Clinical presentation with an isolated palsy of the flexor pollicis longus muscle is difficult to distinguish from a closed tendon rupture, especially when a trauma occurred. We would like to present five of our cases and discuss the diagnostic and therapeutic modalities.

Cocaine- and alcohol-mediated expression of inducible transcription factors is blocked by pentobarbital anesthesia

Identifying the neurocircuitry involved in behavioral responses to drugs of abuse is an important step towards understanding the mechanisms of drug addiction. The present study sought to distinguish brain regions involved in pharmacological effects of cocaine and ethanol from secondary effects by administering these drugs in the presence or absence of pentobarbital anesthesia. Changes in neuronal activity were assessed by immunohistochemical analysis of expression of an inducible transcription factor (ITF), c-Fos, in the brain of rats habituated to repeated pentobarbital anesthesia or saline administration. Cocaine administration (15 mg/kg, i.v.) in non-anesthetized animals produced a strong induction of c-Fos in the striatum and large number of other brain areas. Ethanol administration (2 g/kg, i.p.) induced c-Fos in a smaller number of characteristic brain areas, including the central nucleus of amygdala and paraventricular nucleus of hypothalamus. However, neither of these drugs was able to induce c-Fos in pentobarbital-anesthetized rats (50 mg/kg, i.v.). The suppressive effects of pentobarbital were not specific to c-Fos, such that pentobarbital also suppressed expression of ITFs FosB and Egr1 in the striatum of cocaine-treated rats. On the other hand, pentobarbital by itself strongly induced c-Fos expression in the lateral habenula of saline-, cocaine-, and ethanol-injected rats. It is not clear whether the suppressive effects of anesthesia on ITF expression in other areas are mediated by activation of lateral habenula, or are independent of this event. Our data suggest that in the absence of conscious awareness of drug-associated cues, cocaine and alcohol activate only a fraction of the neural elements engaged in the unanesthetized state.

Workshop IV: drug treatment guidelines for the long-term management of Parkinson's disease

An attempt was made to establish a decision algorithm for the treatment of idiopathic Parkinson's disease at various stages and in different subgroups such as akinetic-rigid or tremor dominance type. We suggest treating young patients with selegiline and a dopamine agonist. In the tremor dominance type we use either budipine or a dopamine agonist. Due to levodopa-induced dyskinesia, we try to avoid levodopa in the early stages of the disease and use it only later in more advanced situations in a combination therapy with dopamine agonists. Since IPS is not only based upon dopamine deficiency but also on resulting glutamatergic overstimulation, we advocate the use of a glutamate antagonist such as amantadine or budipine. Catechol-O-methyl inhibitors are very helpful when wearing-off occurs. Anticholinergics are only used in the early stages of tremor-dominant IPS because we fear enhancing the risk of dementia.

Acetylcholine release in ventral tegmental area by hypothalamic self-stimulation, eating, and drinking

Evidence is presented for an acetylcholine (ACh) input to the midbrain ventral tegmental area (VTA) as part of a system for self-stimulation and ingestive behavior. Male rats were prepared with an electrode in the perifornical lateral hypothalamus and an ipsilateral guideshaft for microdialysis in the VTA. Extracellular ACh increased in the VTA during self-stimulation, auto-stimulation, eating, or drinking. Infusion of atropine into the VTA via the microdialysis probe was sufficient to stop self-stimulation and reduce intake of food. It is concluded that ACh acts at muscarinic receptors in the VTA as part of a circuit that modulates hypothalamic self-stimulation and ingestive behavior.

Epitope insertion into variable loops of HIV-1 gp120 as a potential means to improve immunogenicity of viral envelope protein

We report on the properties of a set of HIV-1 IIIB Env mutants carrying a linear gp41 epitope insertion (LLELDKWASL) in the V1, V2, V3 or V4 variable loop. Insertion of the epitope, which is defined by the HIV-1 neutralizing MAb 2F5, was well tolerated in the V1, V2 and V4 loops, as these mutants were properly expressed, retained reactivity to conformation-dependent monoclonal antibodies and exhibited patterns similar to the parental Env molecule. However, insertion of this epitope in the V3 loop was associated with drastically reduced protein expression. Relative to parental Env molecule, the V1, V2 and V4 insertion mutants demonstrated significantly increased binding to mAb 2F5 in vitro. To evaluate immunogenicity, mice and guinea pigs were immunized with plasmid expression vectors for the mutant proteins. For both mice and guinea pigs, all four mutants elicited anti-gp120 antibody responses. In mice the V1 and V3 insertion mutants, but neither the V2 or V4 insertion mutant nor the parental env, elicited significant titers against the epitope peptide, whereas in guinea pigs, V2 insertion mutant was most effective in eliciting anti-2F5 peptide antibody responses. While original V2 2F5 insertion mutant failed to elicit anti-2F5 peptide responses in mice, studies with 14 additional V2 insertion mutants revealed several insertion sites at which the epitope was able to induce epitope-specific antibody responses. This indicates that the precise position at which the epitope insertion takes place dictates the ability of the mutant to induce the epitope-specific antibody responses. When tested for virus neutralization activity, the guinea pig sera that contain high titers of anti-2F5 peptide antibody failed to enhance the virus neutralizing activity, suggesting that the configuration of 2F5 epitope plays a critical role in inducing neutralizing antibody responses. The results from this study may have potential implications with respect to modification of the HIV-1 Env molecule for the purpose of improving HIV-1 Env immunogenicity.

Self-administration of cocaine increases the release of acetylcholine to a greater extent than response-independent cocaine in the nucleus accumbens of rats

RATIONALE

The neurochemical effects of psychostimulant exposure may depend on how these drugs are encountered. A useful method for examining this issue is to compare neurotransmitter release following response-dependent, or self-administered, drug exposure and response-independent exposure.

OBJECTIVES

This experiment examined the effect of active and passive cocaine administration on acetylcholine (ACh) efflux in the shell region of the nucleus accumbens (NAc) in rats.

METHODS

One group of rats (CSA: cocaine self-administration) was trained to lever-press for intravenous infusions of cocaine (0.42 mg/kg per infusion) on a fixed-ratio-1 schedule of reinforcement. Cocaine infusions were accompanied by the onset of a stimulus light that signaled a 20-s time-out period. Control rats received intravenous cocaine (cocaine non-contingent: CNC) or saline (SAL) in a manner that was not contingent upon their behavior. Drug infusions in these groups were determined by the lever-press behavior of the animals in the CSA group, i.e. they were yoked to rats in the self-administration group such that CNC animals received equal amounts of cocaine as CSA rats. Animals received cocaine or saline in 3-h sessions for 13 consecutive days before testing. On day 14, extracellular ACh was measured in 15-min intervals before, during and after a 3-h session of cocaine exposure using unilateral microdialysis probes located in the NAc shell coupled with HPLC.

RESULTS

ACh efflux was significantly increased above baseline in both groups of rats that received cocaine but CSA rats had significantly higher ACh levels during the self-administration period compared to their yoked counterparts. In addition, ACh efflux remained elevated longer in CSA animals relative to CNC rats following cessation of cocaine exposure.

CONCLUSIONS

These results demonstrate that ACh interneurons in the NAc shell are responsive to cocaine exposure. In addition, these findings suggest that the manner in which the drug is administered (i.e. either by active self-administration or passive exposure) may be relevant to the magnitude of the neural response.

Reduced glutamate immunolabeling in the nucleus accumbens following extended withdrawal from self-administered cocaine

Alterations in the density of GABA and glutamate immunolabeling within nerve terminals in the shell region of the nucleus accumbens were assessed in rats withdrawn from intravenous cocaine exposure. Four groups of rats were used: one group self-administered cocaine (0.42 mg/kg/infusion) in daily 3-h sessions for approximately 2 weeks, two additional groups received either saline or cocaine in a noncontingent fashion, and a fourth comprised a drug-naive, age-matched control group. Immunogold electron microscopy was used to quantify presynaptic terminal GABA and glutamate density within the vesicular and mitochondrial pools approximately 18 days following the last drug or saline exposure in the treatment groups. A significant 27.7% decrease in vesicular glutamate density within asymmetrical nerve terminals was observed in animals that self-administered cocaine as compared to controls. This group also showed an 18.6% decrease in vesicular nerve terminal glutamate immunolabeling as compared to animals that were administered a similar total dose of cocaine in a response-independent fashion. No significant changes in the density of nerve terminal GABA vesicular immunolabeling were observed in any groups. For both transmitters, no differences were detected in the density of immunolabeling within the presynaptic mitochondrial (i.e., metabolic) pool. These results demonstrate that glutamate density is suppressed in the shell region of the nucleus accumbens following withdrawal from 2 weeks of cocaine exposure. The findings also suggest that the motivational aspects that accompany self-administration may participate in this reduction.

Effects of c-raf-1 and c-myc expression on radiation response in an in vitro model of human small-cell-lung carcinoma

In this study we examined the radiation survival response of simian virus 40 large tumor antigen-immortalized human bronchial epithelial cells (BEAS-2B) stably transfected with c-raf-1 and/or c-myc. C-raf-1 transfectants (2B-raf), and c-raf-1 and c-myc double transfectants (2B-raf/myc) were relatively radioresistant compared with c-myc (2B-myc) or control vector transfectants (2B-neo) (2B-raf, D0 = 2.445 Gy; 2B-raf/myc, D0 = 2.46 Gy; 2B-myc, D0 = 1.501 Gy; 2B-neo, D0 = 2.029 Gy). The steady state level of superoxide dismutase (SOD) mRNA was higher in radioresistant cells (2B-raf and 2B-raf/myc). In addition, 2B-raf but not 2B-raf/myc or 2B-myc transfectants revealed relatively higher number of cells in G2+M phase of the cell cycle. These findings present experimental evidence that Raf-1 expression correlates with the radiation-resistant response of 2B-raf or 2B-raf/myc transfectants and suggest a role of SOD in Raf-1-associated radiation resistance. Because 2B-raf transfectants are non-tumorigenic, and double transfectants (2B-raf/myc) are tumorigenic with some phenotypic traits found in small-cell lung carcinomas, our data imply a dissociation between the Raf-1-mediated mechanisms of radiation protection and progression of lung neoplasia.

D1 and D2 dopamine receptor mediation of amphetamine-induced acetylcholine release in nucleus accumbens

To assess the interaction of dopamine and acetylcholine systems in the rat nucleus accumbens in response to direct D-amphetamine administration, in vivo microdialysis measures of acetylcholine were used during reverse dialysis of amphetamine alone and in combination with D1 and D2 receptor antagonists SCH 23390 and sulpiride, respectively. During a 15-min exposure to amphetamine (50 microM) in the nucleus accumbens, acetylcholine increased to 33% above pre-infusion levels, became maximal at 15 min post-infusion (+41%) and gradually returned to baseline levels by 60 min post-amphetamine. Conversely, amphetamine (1 mM) administration caused a biphasic change in acetylcholine release with a trend toward a decrease (-14%) during exposure followed by a significant increase (+36%) at 30 min post-amphetamine that returned to baseline levels by 60 min after infusion. The increases observed during amphetamine (50 microM) exposure and during recovery from amphetamine (1 mM) were both blocked by co-administration with the D1 antagonist, SCH 23390 (10 microM), but not with the D2 antagonist, sulpiride (10 microM). Co-infusion of sulpiride eliminated the trend toward reduced acetylcholine release observed during 1 mM amphetamine whereas co-administration of SCH 23390 potentiated this decrease. A possible tonic D1 facilitation of nucleus accumbens acetylcholine release was indicated by the consistent reductions in acetylcholine release observed during infusion of SCH 23390. These results suggest that amphetamine administration in the nucleus accumbens induces a bidirectional change in acetylcholine release that is dependent on dose and opposing effects of nucleus accumbens D1 and D2 activation. In general, relatively low doses of amphetamine administered into the nucleus accumbens caused an increase in acetylcholine release that was dependent on dopamine D1 receptors whereas higher doses of amphetamine resulted in a D2-mediated decrease.

Galanin in the hypothalamus raises dopamine and lowers acetylcholine release in the nucleus accumbens: a possible mechanism for hypothalamic initiation of feeding behavior

Rats were prepared with two implanted guide shafts, one for microdialysis to measure extracellular dopamine (DA) and acetylcholine (ACh) in the posterior, medial nucleus accumbens (NAc), and the other for microinjection of galanin, neuropeptide Y or saline in the hypothalamic paraventricular nucleus (PVN). There was an increase in DA release and a decrease in ACh in the NAc following microinjections of galanin into the PVN. The effect was observed only in rats for which identical galanin injections induced feeding in separate tests. Ringer injections had no effects. Unlike galanin, neuropeptide Y in the PVN induced eating without altering DA/ACh; whereas earlier results showed that norepinephrine in the PVN works like galanin. These results suggest that galanin initiates feeding, in part, by activating the mesolimbic DA system and suppressing intrinsic cholinergic activity in the NAc. This may prime instrumental behavior with DA while disinhibiting behavior by lowering ACh.

OH-radical formation by ultrasound in aqueous solution--Part II: Terephthalate and Fricke dosimetry and the influence of various conditions on the sonolytic yield

Terephthalate and Fricke dosimetry have been carried out to determine the sonolytic energy yields of the OH free radical and of its recombination product H2O2 in aqueous solutions under various operating conditions (nature of operating gas, power, frequency, temperature). For example, in the sonolysis of Ar-saturated terephthalate solutions at room temperature, a frequency of 321 kHz, and a power of 170 W kg-1, the total yield [G(.OH) + 2 G(H2O2)], equals 16 x 10(-10) mol J-1. This represents the total of .OH that reach the liquid phase from gas phase of the cavitating bubble. The higher the solute concentration, the lower the H2O2 production as more of the OH free radicals are scavenged, in competition with their recombination. Fricke dosimetry, in the absence and presence of Cu2+ ions, shows that the yield of H atom reaching the liquid phase is much lower, with G(H.) of the order of 3 x 10(-10) mol J-1. These sonolytic yields are smaller in solutions that are at the point of gas saturation, and increase to an optimum as the initial sonication-induced degassing and effervescence subsides. The probing of the sonic field has shown that the rate of sonolytic free-radical formation may vary across the sonicated volume depending on frequency and power input.

Does N-acetylcysteine improve hemodynamics and graft function in liver transplantation?

The release of toxic oxidative free radicals induced by ischemia and reperfusion may jeopardize liver graft function. N-acetylcysteine (NAC) has shown protective effects on hypothermic and warm ischemia reperfusion liver injury in animals. NAC improves hemodynamics and survival rates in patients with fulminant hepatic failure. The aim of this study was to investigate whether intraoperative treatment with NAC would improve hemodynamics and postoperative graft function in liver transplantation. Sixty patients with chronic end-stage liver disease were included in a prospective randomized placebo-controlled study. NAC or the same volume of 5% glucose was started during the anhepatic phase. Hemodynamic data and calculated tissue oxygenation parameters were compared throughout the procedure. Postoperative graft function was assessed by measurements of aminotransferases, prothrombin time, and monoethylglycinexylidide test over the 3 first postoperative days. Patient demographics were similar before the infusion of NAC or glucose. Hemodynamic parameters, oxygen consumption, oxygen delivery, oxygen extraction ratio, and lactates were not different throughout the procedure. One hour after the revascularization of the hepatic artery, the oxygen extraction ratio by the liver was similar (17% +/- 7.6% v 17% +/- 6.2%) in both groups. Postoperative graft function was comparable within the 3 first postoperative days. This study failed to show any beneficial effect of the intraoperative administration of NAC on hemodynamics and graft function in liver transplantation in patients with chronic liver disease.

[Granulomatous tumor of the flexor tendon sheath as first manifestation of sarcoidosis]

While osseous tumors of the phalanges are more common, soft-tissue manifestations in the hand are uncommon in patients with sarcoidosis. Our patient presented with a large but painless tumor on the palmar aspect of the right index finger limiting finger flexion. Histology of a biopsy specimen was interpreted as a granuloma of sarcoidosis. Further X-ray investigations revealed large bilateral formations in the hila of the lung interpreted as stage I sarcoidosis in an otherwise healthy individual. Tuberculosis and polyarthritis were excluded by standard tests. The tumor was then radically excised, as it was located within the flexor tendon sheath. After uneventful wound healing the patient had regained full function of his finger at six weeks follow up. Interestingly enough, a chest film at that time showed the hilar changes to have decreased as well, which is considered quite typical for this disease.

Dopamine release in the nucleus accumbens by hypothalamic stimulation-escape behavior

It is known that lateral hypothalamic stimulation or self-stimulation can release dopamine in the nucleus accumbens (NAc). The present experiment illustrates that an aversively motivated behavior can also do this. Rats were prepared with microdialysis probes in the NAc and electrodes in the lateral hypothalamus (LH) or medial hypothalamus (MH). Automatic stimulation of the LH increased extracellular dopamine in the NAc 30% as reported earlier. The animals would perform both self-stimulation to turn the current on and stimulation-escape to turn it off, suggesting a combination of reward and aversion. Escape responding increased extracellular dopamine (DA) 100%, even though there was less total stimulation. Automatic stimulation of the MH did the opposite of the LH by decreasing accumbens dopamine (-20%), and the animals would only perform stimulation-escape, indicative of pure aversion. But again, extracellular DA in the NAc increased 100% during escape responding. Thus DA can be released during negative reinforcement when an animal's behavior is reinforced by escape from lateral or medial hypothalamic stimulation. This suggests that DA release was correlated with stimulation-escape behavior, rather than the aversiveness of automatic stimulation.

Characterization of recombinant hepatitis B surface antigen using surface plasmon resonance

Two commercial monoclonal antibodies were shown to interact with distinct epitopes within the major antigenic a determinant region of yeast recombinant hepatitis B surface antigen (rHBsAg) particles, contained in the hepatitis B vaccine, by using the surface plasmon resonance phenomenon on a BIAcore system. Apparent avidity for these antibodies were compared among different rHBsAg batches, showing the consistency of these epitopes. Furthermore, the effect of the alteration of these epitopes, achieved by chemical modifications, was readily reflected by changes in the apparent avidity for these antibodies. The procedures used in the present study provide a novel and efficient way to characterize rHBsAg particles present in different hepatitis B vaccine products.

Norepinephrine microinjections in the hypothalamic paraventricular nucleus increase extracellular dopamine and decrease acetylcholine in the nucleus accumbens: relevance to feeding reinforcement

Norepinephrine (NE) was microinjected into the paraventricular nucleus (PVN), while microdialysis was used to monitor extracellular dopamine (DA) and acetylcholine (ACh) in the nucleus accumbens (NAc). The PVN is a site where exogenously administered NE can act through alpha 2 receptors to elicit eating behavior and preference for carbohydrates. It was hypothesized that NE in the PVN acts on a behavior reinforcement system by altering the DA/ACh balance in the NAc. NE microinjections (80 nmol in 0.3 microliter), which effectively elicited feeding in satiated rats in a separate test, caused a significant increase in extracellular DA (109%) and decrease in ACh (-27%) when the same animals were tested in the absence of food. In contrast when the food was available and ingested, ACh increased (51%) instead of decreasing. These results support the hypothesis that a functional link exists between the PVN and the NAc in which DA helps initiate and ACh helps stop appetitive behavior involved in the reinforcement of eating.

Inescapable stress enhances extracellular acetylcholine in the rat hippocampus and prefrontal cortex but not the nucleus accumbens or amygdala

A number of experimental results has pointed to a cholinergic involvement in the stress response. Recently, analytical techniques have become available to measure acetylcholine release in vivo during exposure to various stressors. In these experiments, microdialysis was used to monitor acetylcholine output every 15 min in the dorsal hippocampus, amygdala, nucleus accumbens and prefrontal cortex before, during and after 1 h of restraint, including a 15-min session of intermittent tail-shock (1/min, 1 mA, 1-s duration) in rats. In response to the stressful event, acetylcholine release was significantly increased in the prefrontal cortex (186%; p < 0.01) and hippocampus (168%; P < 0.01) but not in the amygdala or nucleus accumbens. The sole effects observed in the amygdala and nucleus accumbens occurred upon release from the restrainer, at which point acetylcholine levels were significantly elevated in both areas (amygdala: 150%; P < 0.05; nucleus accumbens: 13%; P < 0.05). An enhanced acetylcholine release was also evident during this sample period in the hippocampus and prefrontal cortex. These data demonstrate an enhancement of cholinergic activity in response to stress in two acetylcholine projection systems (hippocampus and prefrontal cortex) but not in the intrinsic acetylcholine system of the nucleus accumbens or the extrinsic innervation of the amygdala. Moreover, the data showed that relief from stress was accompanied by a more ubiquitous acetylcholine response that extended to each site tested.

Morphine and naloxone, i.p. or locally, affect extracellular acetylcholine in the accumbens and prefrontal cortex

In rats with microdialysis probes in the nucleus accumbens (NAc) or prefrontal cortex (PFC), intraperitoneally (IP) delivered morphine on the 8th day of escalating doses decreased extracellular ACh in the NAc. On day 9, naloxone (5 mg/kg) precipitated withdrawal and increased the release of ACh. When morphine and methylnaloxonium were given locally into the NAc by reverse dialysis, the opiate again decreased extracellular ACh, and the opiate antagonist increased it. These effects were proportional to the dose of local infusions. Local morphine had the same ACh-lowering effect in morphine-dependent and nondependent rats, whereas local methylnaloxonium increased extracellular ACh significantly more in morphine-dependent animals. Systemic and local effects on ACh systems in the PFC were more complicated and showed some relation to locomotor activity. The results suggest that intrinsic ACh neurons in the NAc have a special relationship to opiate reinforcement such that extracellular ACh is low in response to morphine and high during withdrawal. Thus, low ACh may correlate with opiate reward, and high ACh with aversion.

[Trigger thumb in the child]

The trigger thumb is a quite frequent finding in the adult woman over 50 years. In newly born and small children we do, however, also occasionally observe trigger thumbs. As even pediatric specialists are not necessarily familiar with this diagnosis, they tend to refer these small patients as emergencies for acute distortions or subluxations. We describe the clinical findings and therapy for trigger thumb in the child and our own results in comparison with the literature. Except in the small child under six months, who displays a spontaneous recovery in about 30% of the cases, early surgical release of the pulley is the treatment of choice.

Affinity maturation of a high-affinity human monoclonal antibody against the third hypervariable loop of human immunodeficiency virus: use of phage display to improve affinity and broaden strain reactivity

The present study set out to investigate whether phage display could be used to improve the properties of a high-affinity human monoclonal antibody directed against the third hypervariable loop (V3 loop) of human immunodeficiency virus (HIV). The aim was to increase affinity through slowing the dissociation rate (off-rate constant of koff), whilst retaining the ability of this antibody to bind diverse V3 loop sequences. When reformatted as a scFv, the antibody fragment retained the properties of the parental IgG, including the ability to neutralise virus. Heavy and light chains were sequentially replaced with repertoires of variable domains from non-immunised human donors followed by selection on biotinylated synthetic peptide. All selected variants derived from the same germline as the parental antibody. Variants of the light chain provided little if any improvement, whereas two residue changes in VHCDR2 and one in VHFR3 resulted in a reduced koff from gp120 protein of the MN strain (MNgp120) and synthetic V3 loop peptides as measured by surface plasmon resonance using the BIAcore instrument (Pharmacia Biosensor). VHCDR3 was modified using synthetic oligonucleotides and several clones with reduced koff identified, a number of different substitutions occurring at a single residue position. The residues in the heavy chain identified as reducing koff were simultaneously randomised by site-directed mutagenesis, resulting in scFv variants with koff slowed up to sevenfold. Far from compromising recognition of variant loops, binding to these sequences was improved; the koff from synthetic peptides modelled on V3 loop variants being slowed to a degree similar to that observed with MNgp120. All four changes were located towards either extremes of CDRs 2 and 3, suggesting that the mechanism of improvement may be one of alternation of loop conformation. This work illustrates that phage display can be used to tailor the properties of a therapeutic monoclonal antibody in a predefined fashion.

Extracellular acetylcholine is increased in the nucleus accumbens following the presentation of an aversively conditioned taste stimulus

To determine if acetylcholine (ACh) is released in the nucleus accumbens in response to a conditioned stimulus (CS) that reminds the animal of an aversive event, in vivo microdialysis was used to monitor extracellular ACh during conditioned taste aversion. Saccharin flavored water (2.5 mM saccharin) was paired twice with nausea induced by i.p. lithium chloride (100 mg/kg). This is normally sufficient to create an aversion to the taste of saccharin, but instead of a preference test, the saccharin solution was squirted directly into the rat's mouth via a cheek catheter during nucleus accumbens microdialysis. The result was a 40% increase in extracellular ACh. We reported earlier that dopamine changes in the opposite direction; it decreases. This suggests that high synaptic ACh and low DA are correlated with an aversive state and cessation of behavior.

An appetitively conditioned taste elicits a preferential increase in mesolimbic dopamine release

Rats were prepared with intragastric (IG) cannulae for infusing a nutrient into the stomach and microdialysis guide shafts in the nucleus accumbens (NAC) and striatum (STR) for measuring changes in extracellular dopamine. Prior to dialysis, subjects were trained to prefer the mildly bitter taste of sucrose octaacetate (SOA; CS+) by pairing voluntary intake with automatic IG infusions of nutritive polycose. The mildly sour taste of citric acid (CS-) was paired with IG water infusions as a control. Unconditioned animals received four exposures to SOA and citric acid on counterbalanced, alternating days. After training, dialysis samples were collected every 30 min before, during, and after intake of the CS+ or CS- in response to 14 h water deprivation on counterbalanced, consecutive days. Voluntary intake of the CS+ for 30 min significantly increased extracellular DA in the NAC but not in the STR of conditioned subjects. Intake of the CS- did not alter DA efflux at either site. Unconditioned, control rats also showed no DA response to either taste. These results show selective activation of the mesolimbic dopaminergic projection system as a consequence of a conditioned taste stimulus paired with a nutritive gastric load. This suggests that conditioned DA release may play a role in learned ingestive behavior based on the postingestive effects of food.

Effects of supplemental choline on extracellular acetylcholine in the nucleus accumbens during normal behavior and pharmacological acetylcholine depletion

Brain microdialysis was used to determine whether systemic or local application of choline would modify the extracellular concentration of acetylcholine (ACh) in the nucleus accumbens (NAc) of freely moving rats. Supplemental choline given intraperitoneally or into the NAc of normal rats did not increase extracellular ACh. When local ACh interneurons in the NAc were treated pharmacologically to deplete the intracellular stores of ACh, then systemic choline (80 mg/kg) was an effective treatment. Specifically, 1) blockade of the high-affinity choline transporter with hemicholinium-3 (HC-3) to reduce ACh synthesis caused a decrease in extracellular ACh, but choline supplementation restored ACh toward its normal level in the NAc. 2) Local bicuculline treatment released ACh to the point of depletion, but systemic choline or locally infused choline helped maintain normal ACh levels. These results suggest that choline supplementation might be useful in preventing depletion of ACh in the nucleus accumbens during pathological conditions.

The influence of different amounts of n-3 polyunsaturated fatty acids on bleeding time and in vivo vascular reactivity

Mesenteric bleeding time, mesenteric vascular reactivity, platelet and erythrocyte lipid fatty acid composition were measured at 2-3 weeks, 5-6 weeks and 11-22 weeks in normotensive Wistar rats, fed on high (6.5% energy) or moderate (1.6% energy) intakes of eicosapentaenoic acid (20:5n-3; EPA) as fish oil, compared with controls fed on a diet devoid of EPA. All diets contained the same level of linoleic acid (4% energy): the moderate- and high-EPA diets also contained 1.1 and 4.4% of the energy as docosahexaenoic acid (22:6n-3) respectively. Moderate, but not high, intakes of EPA increased mesenteric bleeding time. Similar reductions in erythrocyte and platelet arachidonic acid (20:4n-6) occurred in animals fed on either high or low amounts of EPA, but the proportion of EPA increased dose-dependently. At high intakes of EPA the proportion of oleic acid in platelets and erythrocytes was decreased. Blood pressure platelet counts, mesenteric vessel diameter and mesenteric vascular reactivity to vasopressin were unaffected by treatment. High intakes of fish oil led to a slight fall in packed cell volume. In a second experiment bleeding time and mesenteric vascular reactivity to noradrenaline were increased 2-4 weeks after receiving a moderate intake of EPA and these effects persisted 5-21 d after switching to a control diet. A similar increase in vascular reactivity to noradrenaline was observed in animals given indomethacin (6 mg/kg) but not in those given aspirin (20 mg/kg).