State programs assisting pharmacy professionals with substance use disorders.

OBJECTIVES: To identify which states currently have substance use disorder (SUD) programs to facilitate the return of pharmacy professionals (including technicians, interns, and student pharmacists) to active practice, to identify the operational structures used by the states in providing these services and compare them with those reported previously, and to compile the most current and accurate contact information for each state SUD program. METHODS: Information specific to each state program was identified from Internet resources including state pharmacy associations, licensing boards, and professional associations. Each state's site was evaluated for currency within 2016-2017. Direct contact by e-mail or telephone using the program information, or association, or licensing board contacts was pursued to identify the current program status. RESULTS: Five states with no program in 1990 have since developed programs, and 2 states with programs in 1990 have closed their programs. Overall, 4 states do not currently have a program, 2 of which have never had one. One of the 2 states has recent authorization from their legislature to develop a program. Three other programs are currently in transition from 1 model to another, resulting in website inaccuracies. The operational models have undergone significant shifts with a decrease in the association (± [with or without] Foundation) model toward a group health care association or organization model including other health- or all state-licensed professionals. CONCLUSION: Currently, 46 states have programs for assisting pharmacy professionals. Information presented in this article provides the most current contact information and model structure used by states with programs. Frequent updating of program information is critical for those who might decide to seek assistance. Expansion to include a central database that enables rigorous evaluation of outcomes and specific features is viewed as desirable.

Electrophysiological and Immunohistochemical Evidence for an Increase in GABAergic Inputs and HCN Channels in Purkinje Cells that Survive Developmental Ethanol Exposure.

Ethanol exposures during the early postnatal period of the rat result in significant death of Purkinje cells (PCs). The magnitude, time-course, and lobular specificity of PC death have been well characterized in several studies. Additionally, significant reduction of climbing fiber inputs to the surviving PCs has been characterized. This study investigates whether further alterations to the cerebellar cortical circuits might occur as a result of developmental ethanol exposures. We first examined the firing pattern of PCs in acute slice preparations on postnatal days 13-15. While the basic firing frequency was not significantly altered, PCs from rat pups treated with ethanol on postnatal days 4-6 showed a significantly increased number of inhibitory postsynaptic potentials (IPSCs) and a larger Ih current. We conducted immunofluorescent studies to identify the probable cause of the increased IPSCs. We found a significant 21 % increase in the number of basket cells per PC and a near doubling of the volume of co-localized basket cell axonal membrane with PC. In addition, we identified a significant (~147 %) increase in HCN1 channel volume co-localized to PC volume. Therefore, the cerebellar cortex that survives targeted postnatal ethanol exposure is dramatically altered in development subsequent to PC death. The cerebellar cortical circuit that results is one that operates under a significant degree of increased resting inhibition. The alterations in the development of cerebellar circuitry following ethanol exposure, and the significant loss of PCs, could result in modifications of the structure and function of other brain regions that receive cerebellar inputs.

The fine temporal structure of the rat licking pattern: what causes the variabiliy in the interlick intervals and how is it affected by the drinking solution?

Licking is a repetitive behavior controlled by a central pattern generator. Even though interlick intervals (ILIs) within bursts of licks are considered fairly regular, the conditions that affect their variability are unknown. We analyzed the licking pattern in rats that licked water, 10% sucrose solution, or 10% ethanol solution, in 90-min recording sessions after 4h of water deprivation. The histograms of ILIs indicate that licking typically occurred at a preferred ILI of about 130-140ms with evidence of bimodal or multimodal distributions due to occasional licking failures. We found that the longer the pause between bursts of licks, the shorter was the first ILI of the burst. When bursts of licks were preceded by a pause >4 s, the ILI was the shortest (~110ms) at the beginning of the burst, and then it increased rapidly in the first few licks and slowly in subsequent licks. Interestingly, the first ILI of a burst of licks was not significantly different when licking any of the 3 solutions, but subsequent licks exhibited a temporal pattern characteristic of each solution. The rapid deceleration in intraburst licking rate was due to an increase from ~27ms to ~56ms in the tongue-spout contact duration while the intercontact interval was only slightly changed (80-90ms). Therefore, the contact duration seems to be the major factor that increases the variability in the ILIs and could be another means for the rat to adjust the amount of fluid ingested in each individual lick.

The utility of non-axial treatment beam orientations for lower lobe lung cancers.

Traditional treatment beams for non-small-cell lung cancer are limited to the axial plane. For many tumor geometries, non-axial orientations appear to reduce the dose to normal tissues (e.g. heart, liver). We hypothesize that non-axial beams provide a significant reduction in incidental irradiation of the heart and liver, while maintaining adequate target coverage. CT scans of twenty-four patients with lower lobe lung cancers were studied. For each patient, an opposed oblique axial beam pair and a competing non-axial opposed oblique pair were generated, both off-cord. The competing plans delivered comparable doses/margins to the GTV. DVHs and integral doses were computed for all structures of interest for the two competing plans. The integral dose was compared for axial and non-axial beams for each contoured organ using a paired t-test. Dose to the heart was significantly lower for the non-axial plans ( p = .0001). For 20/24 patients, the integral heart dose was reduced by using non-axial beams. In those patients with tumors located in the inferior right lower lobe, a lower dose to the liver was achieved when non-axial beams were used. There were no meaningful differences in dose to the GTV, lungs, or skin between axial and non-axial beams. Non-axial beams can reduce the dose to the heart and liver in patients with lower lobe lung cancers. Non-axial beams may be clinically beneficial in these patients and should be considered as an option during planning.

A Transgenic Mouse Model to Selectively Identify α3 Na,K-ATPase Expressing Cells in the Nervous System.

The α3 Na+,K+-ATPase (α3NKA) is one of four known α isoforms of the mammalian transporter. A deficiency in α3NKA is linked to severe movement control disorders. Understanding the pathogenesis of these disorders is limited by an incomplete knowledge of α3NKA expression in the brain as well as the challenges associated with identifying living cells that express the isoform for subsequent electrophysiological studies. To address this problem, transgenic mice were generated on the C57BL/6 genetic background, which utilize the mouse α3 subunit gene (Atp1a3) promoter to drive the expression of ZsGreen1 fluorescent protein. Consistent with published results on α3NKA distribution, a ZsGreen1 signal was detected in the brain, but not in the liver, with Atp1a3-ZsGreen1 transgenic mice. The intensity of ZsGreen1 fluorescence in neuronal cell bodies varied considerably in the brain, being highest in the brainstem, deep cerebellar and select thalamic nuclei, and relatively weak in cortical regions. Fluorescence was not detected in astrocytes or white matter areas. ZsGreen1-positive neurons were readily observed in fresh (unfixed) brain sections, which were amenable to patch-clamp recordings. Thus, the α3NKA-ZsGreen1 mouse model provides a powerful tool for studying the distribution and functional properties of α3NKA-expressing neurons in the brain.

Efficacy and Safety of Low-Dose Iodine Plaque Brachytherapy for Juxtapapillary Choroidal Melanoma.

PURPOSE: To evaluate low- vs high-dose plaque brachytherapy for juxtapapillary choroidal melanoma. DESIGN: Retrospective interventional case series. METHODS: Setting: Single institution. STUDY POPULATION: Forty-seven patients with juxtapapillary choroidal melanoma. INTERVENTION: Iodine-125 plaque brachytherapy. Eyes were divided into apex low-dose (LD) and high-dose (HD) groups (≤ or > median apex dose 84.35 Gy). Main outcome measures were time to distant failure, local failure, death, enucleation, radiation retinopathy, optic neuropathy, and best-corrected visual acuity (BCVA). RESULTS: Freedom from distant failure rates were 96% and 95% in apex LD and HD groups at 5 years and 77% and 95% at 10 years, respectively (P = .84). Freedom from local failure rates were 90% in the apex LD group vs 89% in the HD group at 5 and 10 years (P = .96). Apex LD and HD groups did not differ for time to death or enucleation. Five- and 10-year freedom from radiation retinopathy and optic neuropathy rates were higher in the apex LD than HD group. Loss of ≥3 BCVA lines, final BCVA 20/40 or better, and final BCVA 20/200 or worse were more favorable in the 5 mm LD compared to HD group. Visual acuity outcomes did not differ between apex LD and HD groups. CONCLUSIONS: Low-dose iodine-125 plaque brachytherapy (67.5-81 Gy at tumor apex) provides safe and effective tumor control for juxtapapillary choroidal melanoma and may be associated with reduced radiation toxicity. Larger trials are needed to determine the optimal therapeutic dose for juxtapapillary choroidal melanoma.

The impact of advanced technologies on treatment deviations in radiation treatment delivery.

PURPOSE: To assess the impact of new technologies on deviation rates in radiation therapy (RT). METHODS AND MATERIALS: Treatment delivery deviations in RT were prospectively monitored during a time of technology upgrade. In January 2003, our department had three accelerators, none with "modern" technologies (e.g., without multileaf collimators [MLC]). In 2003 to 2004, we upgraded to five new accelerators, four with MLC, and associated advanced capabilities. The deviation rates among patients treated on "high-technology" versus "low-technology" machines (defined as those with vs. without MLC) were compared over time using the two-tailed Fisher's exact test. RESULTS: In 2003, there was no significant difference between the deviation rate in the "high-technology" versus "low-technology" groups (0.16% vs. 0.11%, p = 0.45). In 2005 to 2006, the deviation rate for the "high-technology" groups was lower than the "low-technology" (0.083% vs. 0.21%, p = 0.009). This difference was caused by a decline in deviations on the "high-technology" machines over time (p = 0.053), as well as an unexpected trend toward an increase in deviations over time on the "low-technology" machines (p = 0.15). CONCLUSIONS: Advances in RT delivery systems appear to reduce the rate of treatment deviations. Deviation rates on "high-technology" machines with MLC decline over time, suggesting a learning curve after the introduction of new technologies. Associated with the adoption of "high-technology" was an unexpected increase in the deviation rate with "low-technology" approaches, which may reflect an over-reliance on tools inherent to "high-technology" machines. With the introduction of new technologies, continued diligence is needed to ensure that staff remain proficient with "low-technology" approaches.

Simultaneous integrated boost (SIB) for treatment of gynecologic carcinoma: Intensity-modulated radiation therapy (IMRT) vs volumetric-modulated arc therapy (VMAT) radiotherapy.

The aim of this study was to quantitatively compare dosimetric criteria between intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans for patients undergoing radiation treatment of gynecologic carcinoma with a simultaneous integrated boost (SIB) technique. IMRT and VMAT plans were retrospectively analyzed for 20 patients. The elective volume was planned to receive 45 Gy in 25 fractions of 1.8 Gy, with the integrated boost volume (involved nodes) receiving 55 Gy simultaneously. The same dose constraints were employed during the optimization of both techniques. IMRT plans consisted of 9 to 11 fields at equally spaced gantry angles. VMAT plans consisted of 3 full arcs of 360°. A large variety of dose metrics across planning target volume (PTV)45, PTV55, bladder, rectum, sigmoid, bowel, kidneys, and femoral heads were extracted per patient, per plan. Conformity and homogeneity indices were also calculated and compared for each target volume. The total number of monitor units as well as the integral dose was also compared between IMRT and VMAT. The Wilcoxon signed rank test was performed to evaluate any significant differences between parameters, with an applied Bonferroni correction to account for multiple testing (significance level, p < 0.0006). The results demonstrate the equivalence of the 2 planning techniques across all studied parameters, with the exception of the expected decrease in monitor units that VMAT is capable of achieving. The findings of this study suggest that IMRT and VMAT are both acceptable options for applying simultaneous integrated boost techniques for the treatment of gynecologic cancers. The technique of choice will be dependent on departmental resources and should be considered on a case-by-case basis.

Patterns of failure after resection of non-small-cell lung cancer: implications for postoperative radiation therapy volumes.

PURPOSE: To analyze local-regional patterns of failure after surgical resection of non-small-cell lung cancer (NSCLC). METHODS AND MATERIALS: This retrospective analysis included 61 patients who underwent resection of NSCLC at Duke University Medical Center. Inclusion into the study required the following: margin-negative resection, no neoadjuvant/adjuvant radiation therapy (RT), first recurrence involving a local-regional site, and imaging studies available for review. Sites of intrathoracic disease recurrence were documented. Diagrams were constructed that illustrated sites of failure on the basis of lobe of primary tumor. Failure rates were compared by application of a two-tailed Fisher's exact test. RESULTS: All patients had CT imaging for review, and 54% also had PET imaging. The median number of local-regional recurrent sites was two (range, 1-6). For all patients, the most common site of failure was the bronchial stump/staple line (44%), which was present more often in those who had a wedge resection than in those who had a more radical procedure (79% vs. 34%, p=0.005). Patients with initial nodal involvement (pN1-2) were not more likely to have involvement of the mediastinum than were patients with pN0 disease (64% vs. 72%, p=0.72), but were more likely to have involvement of the supraclavicular fossa (27% vs. 4%, p=0.04). Mediastinal involvement, without overt evidence of hilar involvement, occurred in 59% of patients. Left-sided tumors tended to involve the contralateral mediastinum more frequently than did right-sided tumors. Patterns of failure after resection are diagrammed and follow a fairly predictable pattern on the basis of involved lobe. CONCLUSIONS: These data may help clinicians construct postoperative RT volumes that are smaller than ones traditionally utilized, which may improve the therapeutic ratio.

Predictors of severe gastrointestinal toxicity after external beam radiotherapy and interstitial brachytherapy for advanced or recurrent gynecologic malignancies.

PURPOSE: The aim of this retrospective review of patients with gynecologic malignancies treated with external beam radiotherapy (EBRT) and interstitial brachytherapy was to determine the rate of Grade > or =2 rectovaginal fistula and Grade > or =4 small bowel obstruction as defined by the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3.0. METHODS AND MATERIALS: Thirty-six patients with primary and recurrent gynecologic cancers were treated with EBRT and interstitial brachytherapy. Median doses to tumor, bladder, and rectum were 75 Gy, 61 Gy, and 61 Gy, respectively. A univariate analysis was performed to identify variables that correlated with toxicity. RESULTS: At median follow-up of 19 months, the 3-year risk of small bowel obstruction was 6%. Those patients with prior abdomino-pelvic surgery who received EBRT with antero-posterior fields had higher rates of obstruction than patients without prior abdomino-pelvic surgery or those who received EBRT with four fields (50% vs. 0%, p < 0.0001). The 3-year risk of rectovaginal fistula was 18% and was significantly higher in patients who received >76 Gy to the rectum compared with those who received < or =76 Gy (100% vs. 7%, p = 0.009). CONCLUSIONS: Patients treated with EBRT and interstitial brachytherapy after abdomino-pelvic surgery should receive EBRT with four fields and the cumulative rectal dose should be < or =76 Gy.

Are oxidative mechanisms primary in ethanol induced Purkinje neuron death of the neonatal rat?

Rat cerebellar Purkinje neurons are vulnerable to ethanol exposure during the brain growth spurt, especially during early postnatal exposure. A prominent hypothesis is that ethanol induces oxidative types of alterations that result in the neurodegeneration. The purpose of this study was to test this hypothesis in two ways. One was to determine if the reactive oxidative species, nitrotyrosine (NT), was produced in the cerebellum following ethanol exposure. Second, was to determine if co-administration of the clinically useful antioxidant N-acetylcysteine (NAC) afforded any protection from Purkinje neuron loss. Rat pups were treated on postnatal day 4 with a single ethanol (6.0 g/kg) or isocaloric intragastric intubation. The cerebelli were analyzed for NT with ELISA assays at 2, 4, 6, or 8 h following the single exposure. No evidence of NT was found at any of these time points. Another group of animals received ethanol exposure on PN4, or ethanol exposure plus NAC. Control groups included isocaloric intubated controls (IC), IC plus NAC, and mother reared controls. Twenty-four hours following the exposures, the pups were perfused and the cerebellum processed for cell counting. Ethanol exposure reduced the number of Purkinje neurons in the cerebellum. Concurrent treatment with antioxidant did not protect the Purkinje neurons from ethanol-related cell loss. These in vivo analyses do not support a robust oxidative mechanism involving the production of reactive nitrogen species as a significant means of Purkinje cell neurodegeneration.

Target-determined expression of alpha3 isoform of the Na+,K+-ATPase in the somatic nervous system of rat.

Factors that determine the differential expression of isoforms of Na(+),K(+)-ATPase in the nervous system of vertebrates are not understood. To address this question we studied the expression of alpha(3) Na(+),K(+)-ATPase in the L5 dorsal root ganglia (DRG) of developing rat, the normal adult rat, and the adult rat after peripheral axotomy. During development, the first alpha(3) Na(+),K(+)-ATPase-positive DRG neurons appear by embryonic day 21. At birth, the L5 DRG have a full complement (14 +/- 2%) of these neurons. By 15 days after sciatic nerve transection in adult rat, the number of alpha(3) Na(+),K(+)-ATPase-positive DRG neurons and small myelinated L5 ventral root axons decreases to about 35% of control counts. These results combined with data from the literature suggest that the expression of alpha(3) Na(+),K(+)-ATPase by rat somatic neurons is determined by target-muscle spindle-derived factors.

Preliminary report of the 6-minute walk test as a predictor of radiation-induced pulmonary toxicity.

PURPOSE: To assess the 6-minute walk test (6MWT) as a predictor of radiation therapy-induced lung injury (RTLI). METHODS AND MATERIALS: The 6MWT is a simple, economical, and reproducible test that measures both how far a person can walk in 6 min and any associated changes in vital signs. As part of a prospective trial to study RTLI, a pre-RT 6MWT was performed in 41 patients. The predictive capacities of pre-RT 6MWT, forced expiratory volume in 1 s (FEV1), and single-breath diffusing capacity for carbon monoxide (DLCO) for the development of RTLI were assessed with receiver operating curve (ROC) techniques. To evaluate the 6MWT, alone or with mean lung dose (MLD) of radiation, as a predictor of RTLI, the rates of RTLI in patient subgroups defined by 6MWT results were compared by using Fisher's exact test. RESULTS: Thirty-one patients with > or =3 months' follow-up were evaluable. The median baseline 6MWT result was 1400 ft. Of 31 patients, 7 developed Grade > or =2 RTLI. Of 15 patients with an MLD >18 Gy (the median), 5 developed RTLI, compared with 2 of 16 with MLD < or =18 Gy (p = 0.22). Among those with an MLD < or =18 Gy, the RTLI rates were 0 of 8 and 2 of 8 for 6MWT results > or =1400 ft or <1400 ft, respectively, p = 0.46. The ROC area under the curve for individual metrics was as follows: FEV1 0.66, MLD 0.70, DLCO 0.61, and 6MWT 0.47. Combining FEV1 with 6MWT increased the ROC to 0.71, suggesting that the ratio might be a better predictor than the individual values. Patients with a high 6MWT/FEV1 ratio had a lower rate of RTLI than those with a relatively low ratio. CONCLUSIONS: The 6MWT might provide prognostic information beyond pulmonary function tests and dosimetric parameters in predicting RTLI. Additional work is needed to better assess the utility of these functional metrics.

An artificial neural network for predicting the incidence of radiation pneumonitis.

A method to predict radiation-induced pneumonitis (RP) using an artificial neural network (ANN) was investigated. A retrospective study was applied to the clinical data from 142 patients who have been treated with three-dimensional conformal radiotherapy for tumors in the thoracic region. These data were classified, based on their treatment outcome, into two patient clusters: with RP (Np=26) and without RP (Np= 116). An ANN was designed as a classifier. To perform the classification, a patient-treatment outcome with RP was assigned a value of 1, and a patient treatment outcome without RP was assigned a value of -1. The input of the ANN was limited to the patient lung dose-volume data only. A volume vector (VD) that describes patient lung subvolumes receiving more than a set of threshold doses was used as the network input variable. A zero value was used as the threshold to set the output value into -1 or 1. Three ANNs (ANN_1, ANN_2, and ANN_3), each with three layers, were trained to perform this classification function and to show the effect of training data on the ANN performance. Radial basis function was applied as the hidden layer neuron activation function and a sigmoid function was selected as the output layer neuron function. Backpropagation with a conjugate gradient algorithm was used to train the network. ANN_1 was trained and tested by using the leave-one-out method. ANN_2 was trained by randomly selecting 2/3 of the patient data, and tested by the remaining 1/3 of the data. ANN_3 was trained by a user selecting 2/3 of the patient data, and tested by the remaining 1/3 of the data. The predictive accuracy was verified as the area under a receiver operator characteristic (ROC) curve. The correct classification rates of 73% for RP cases, and 99% for non-RP cases were obtained from ANN_1. The corresponding correct classification rates of 44% for RP cases, and 89% for non-RP cases were obtained from ANN_2. From the ANN_3 test phase, the corresponding correct classification rates of 55% for RP cases, and 95% non-RP cases were achieved. The area under ROC curve was 0.85+/-0.05, 0.68+/-0.10, and 0.81+/-0.09 for ANN_1, ANN _2, and ANN_3, respectively, within its asymmetric 95% confidence interval. The sensitivity was 95%, 57%, and 71%, and the specificity was 94%, 88%, and 90% for ANN_1, ANN_2, and ANN_3, respectively. Preliminary results suggest that the ANN approach provides a useful tool for the prediction of radiation-induced lung pneumonitis, using the patient lung dose-volume information.

Predicting radiotherapy-induced cardiac perfusion defects.

The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/ chestwall patients treated with tangential photon fields. The mathematical models compared were three commonly used parametric models [Lyman normal tissue complication probability (LNTCP), relative serialty (RS), generalized equivalent uniform dose (gEUD)] and a nonparametric model (Linear discriminant analysis--LDA). Data used by the models were the left ventricular dose--volume histograms, or SPECT-based dose-function histograms, and the presence/absence of SPECT perfusion defects 6 months postradiation therapy (21 patients developed defects). For the parametric models, maximum likelihood estimation and F-tests were used to fit the model parameters. The nonparametric LDA model step-wise selected features (volumes/function above dose levels) using a method based on receiver operating characteristics (ROC) analysis to best separate the groups with and without defects. Optimistic (upper bound) and pessimistic (lower bound) estimates of each model's predictive capability were generated using ROC curves. A higher area under the ROC curve indicates a more accurate model (a model that is always accurate has area = 1). The areas under these curves for different models were used to statistically test for differences between them. Pessimistic estimates of areas under the ROC curve using dose-volume histogram/ dose-function histogram inputs, in order of increasing prediction accuracy, were LNTCP (0.79/0.75), RS (0.80/0.77), gEUD (0.81/0.78), and LDA (0.84/0.86). Only the LDA model benefited from SPECT-based regional functional information. In general, the LDA model was statistically superior to the parametric models. The LDA model selected as features the left ventricular volumes above approximately 23 Gy (V23), essentially volume in field, and 33 Gy (V33), as best separating the groups with and without defects. In conclusion, the nonparametric LDA model appears to be a more accurate predictor of radiotherapy-induced left ventricular perfusion defects than commonly used parametric models.

Myocardial perfusion changes in patients irradiated for left-sided breast cancer and correlation with coronary artery distribution.

PURPOSE: To evaluate postradiation regional heart perfusion changes with single photon emission tomography (SPECT) myocardial perfusion imaging in 69 patients treated with tangential photon beams radiation therapy (RT) for left-sided breast cancer. To correlate SPECT changes with percent irradiated left ventricle (LV) volume and risk factors for coronary artery disease (CAD). METHODS AND MATERIALS: Rest SPECT of the LV was acquired pre-RT and at 6-month intervals post-RT. The extent of defects (%) with a severity > 1.5 standard deviations below the mean was quantitatively analyzed for the distributions of the left anterior descending (LAD) artery, left circumflex (LCX) artery, and right coronary artery (RCA) based on computer assisted polar map reconstruction (i.e., bull's-eye-view). Changes in perfusion were correlated with percent irradiated LV receiving > 25 Gy (range 0-32%). Data on patient- and treatment-related factors were collected prospectively (e.g., cardiac premorbidity, risk factors for CAD, chemotherapy, and hormonal treatment). RESULTS: In the LAD distribution, there were increased perfusion defects at 6 months (median 11%; interquartile range 2-23) compared with baseline (median 5%; interquartile range 1-14) (p < 0.001). There were no increases in perfusion defects in the LCX or RCA distributions. In multivariate analysis, the SPECT perfusion changes in the LAD distribution at 6 months were independently associated with percent irradiated LV (p < 0.001), hormonal therapy (p = 0.005), and pre-RT hypercholesterolemia (p = 0.006). The SPECT defects in the LAD distribution at 12 and 18 months were not statistically different from those at 6 months. The perfusion defects in the LAD distribution were limited essentially to the regions of irradiated myocardium. CONCLUSION: Tangential photon beam RT in patients with left-sided breast cancer was associated with short-term SPECT defects in the vascular distribution corresponding to the radiation portals. Factors related to the extent of perfusion defects included the percent irradiated LV, hormonal treatment, and pre-RT hypercholesterolemia.

Altered expression of Bcl2, Bad and Bax mRNA occurs in the rat cerebellum within hours after ethanol exposure on postnatal day 4 but not on postnatal day 9.

Previous studies have demonstrated that ethanol exposure during the vulnerable postnatal (PN) day 4-6 period results in a dose-dependent loss of Purkinje neurons in rats by apoptosis. Although the mechanism of ethanol action and the reasons for Purkinje cell vulnerability are unknown, we hypothesize that during the PN4-6 vulnerable period Purkinje cells are dependent on active trophic factor suppression of apoptosis. Furthermore, ethanol acts to prevent the reception of this trophic signaling resulting in the execution of the apoptotic pathway that includes specific alterations of proteins in the Bcl2 gene family. Ethanol exposure that occurs after this vulnerable period (i.e. PN9) would not be expected to demonstrate alterations in these apoptotic proteins since the Purkinje cells no longer demonstrate vulnerability to ethanol. The current study was undertaken to identify the alterations in mRNA expression for members of the Bcl2-family within the initial hours following ethanol administration on PN4 or PN9. Semi-quantitative reverse transcriptase with polymerase chain reaction (PCR) techniques were used to determine the expression levels of pro-apoptotic factors Bad and Bax, and anti-apoptotic Bcl(2) mRNA. Ethanol was administered at four different doses (1.5, 3.0, 4.5, and 6.0 g/kg) on PN4 and analyses of whole cerebellar mRNA was conducted at 1, 4, 6, and 8 h after treatment. Doses greater than 1.5 g/kg produced significant decreases in Bcl(2) and significant increases in Bad and Bax mRNA during the 8-h period after treatment. In stark contrast, when ethanol was administered at 3.0 or 6.0 g/kg to PN9 pups, no significant alterations of these apoptotic factors were identified at either 1 or 4 h after treatment. These results are in agreement with and provide further support for our hypothesis that ethanol interrupts the active suppression of apoptosis that is a crucial feature of Purkinje cell vulnerability during this time period.

Ethanol-induced alterations of neurotrophin receptor expression on Purkinje cells in the neonatal rat cerebellum.

Ethanol causes loss of Purkinje cells in the cerebellum during the early stages of differentiation and maturation by a presently unknown mechanism. Neuronal vulnerability in the cerebellum parallels the prominent temporal and anatomical gradients of development (i.e. early to late interlobular and posterior to anterior, respectively). Development of Purkinje cells is known to require binding of the neurotrophins, including brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3), to the tyrosine-kinase (Trk) receptors TrkB and TrkC, respectively. In addition, Purkinje cells are reported to experience a critical switch between BDNF dependence and NT3 dependence during the period of highest ethanol sensitivity between postnatal days (PN) 4-6. To test the hypothesis that ethanol alters neurotrophin signaling leading to Purkinje neuronal death, the immunohistochemical expression of TrkB and TrkC receptors on Purkinje cells of rat pups following a moderate dose of ethanol was determined at various times surrounding the period of postnatal ethanol vulnerability. Ethanol selectively decreased Purkinje cell expression of TrkB and TrkC receptors following exposures within the vulnerable period (PN4-6). These results suggest that ethanol may induce loss of Purkinje cells by alteration of neurotrophic regulation at this critical stage.

Alterations of cerebellar mRNA specific for BDNF, p75NTR, and TrkB receptor isoforms occur within hours of ethanol administration to 4-day-old rat pups.

Developing cerebellar Purkinje cells of the rat are extremely sensitive to ethanol during postnatal days (PN) 4-6, but not at later times during development. Ethanol exposure during this vulnerable window induces rapid apoptotic Purkinje cell death that is hypothesized to result from ethanol inhibition in brain-derived nerve growth factor (BDNF)-TrkB neurotrophic signaling that results in loss of apoptotic suppression. In this study, the effect that different concentrations of ethanol (1.5, 3.0, 4.5 and 6.0 g/kg) have on steady-state mRNA expression of BDNF and different TrkB receptor isoforms in the cerebellum on PN4 was determined at 1, 4, 6, and 8 h after treatment. Significant decreases in mRNA specific for BDNF and TrkB isoforms were detected within 1 h after ethanol administration. No significant alterations in expression of mRNA specific to the low affinity p75(NTR) receptor were identified. These alterations are concurrent with the PN4 vulnerable period for Purkinje cells since equivalent treatment of PN9 rat pups does not produce significant alterations in mRNA specific to BDNF or TrkB at 4 h after exposure. These results support the hypothesis that ethanol induces a disruption of BDNF-TrkB signaling that results in loss of apoptotic suppression in vulnerable Purkinje cells by growth factor withdrawal.

Detection of Purkinje cell loss following drug exposures to developing rat pups using reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for calbindin-D28k mRNA expression.

A technique is described that allows for the identification and quantification of Purkinje cell loss in cerebellum subsequent to developmental toxic exposures. This technique relies upon the extensively validated findings that the Purkinje cell is the only site of expression in the cerebellum of the calcium binding protein calbindin-D28k. Thus, analysis of mRNA expression specific to this protein by comparison to matched controls provides a reliable means of determining whether cell loss has occurred. Purkinje cell loss was induced in rat pups by ethanol exposure on postnatal day (PN) 4 or valproic acid administration to pregnant dams on gestational day 13. Analysis was conducted on PN5 or PN10 and the results compared to parallel groups of pups where the Purkinje cells were counted by traditional means. When compared to matched control rat pups the decrease in calbindin-D28k mRNA expression indicates Purkinje cell loss regardless of whether the cell loss was induced by prenatal valproic acid or postnatal ethanol exposure. The availability of a biochemical alternative to histological cell counting allows for more detailed analyses of the mechanisms of Purkinje cell death induced by these two toxicants, including analyses of the early alterations in signal transduction proteins.