The impact of race and ethnicity on diffuse large B-cell lymphoma outcomes within the veterans health administration (VHA).

We performed a retrospective chart review of 6266 randomly selected DLBCL patients treated in the VHA nationwide between 1/1/2011 and 12/31/2021. The 3178 patients who met inclusion criteria were predominantly male (97%) and white (75%). Median age of diagnosis for Black patients was 63 years vs 69 years for the entire cohort (p < 0.001). However, patients in each race/ethnicity subgroup presented with similar rates of stage I/II and III/IV disease, IPI score, cell of origin and HIT status. Outcomes analysis revealed similar treatment, response rates, median overall survival, and 1-, 3-, and 5-year survival across all subgroups. Hispanic patients had a 21% lower risk of death (HR = 0.79) than white patients, and Black patients had no significant difference in survival (HR = 0.98). This large retrospective study shows that when standard of care therapy is given within an equal access system, short-term treatment and survival outcomes are the same for all races.

Clinical Characteristics, Treatment Patterns, and Outcomes of Patients With Locally Advanced/Metastatic Hepatocellular Carcinoma Treated at the Veterans Health Administration.

PURPOSE: This study retrospectively reviewed the outcomes of patients with advanced hepatocellular carcinoma (HCC) receiving atezolizumab with bevacizumab (A + B) therapy at the Veterans Health Administration (VHA). PATIENTS AND METHODS: Patients with advanced HCC who received first-line systemic therapy with A + B at the VHA between December 1, 2019, and March 1, 2022, were selected from electronic medical records (EMR) using ICD-9 and ICD-10 codes. Abstractors reviewed the EMR of the patients from their index date of A + B initiation until death or their last VHA visit, with the study period ending on January 31, 2023. The chi-square test was used to compare rates, and the Mann-Whitney test was used to compare medians. RESULTS: A total of 332 patients met the study criteria. The median age was 67 years; 99% were male, 63% were non-Hispanic Whites, 26% were Black, and 66% had an Eastern Cooperative Oncology Group performance status of ≥1. 84% had child Pugh score (CPS) class A, 16% had CPS classes B and C, 62% had a grade 2 albumin-bilirubin score, 56% had HCC caused by viral hepatitis, 80% had cirrhosis, and 67% had received prior local therapies. The 6-month progression-free survival (PFS) was 59%, while the 1-year PFS rate was 36%. Overall survival (OS) at 1-year was 52% in our study. CONCLUSION: In real world, despite having similar PFS as the phase III IMbrave 150 trial, our OS at 12 months was lower (52% vs. 67%) because our study included a higher proportion of elderly patients with moderate liver dysfunction and a 40% non-White. This study provided real-world outcomes that differed from the study population in a pivotal trial.

The Impact of Time From Diagnosis to Initiation of Chemotherapy on Survival of Patients With Newly Diagnosed Diffuse Large B-Cell Lymphoma in the Veterans Health Administration.

INTRODUCTION: Our retrospective study evaluates the impact of time from diagnosis to treatment (TDT) on outcomes of patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) treated within the Veterans Health Administration (VHA). METHODS: VHA patients diagnosed with DLBCL between 2011 and 2019 were included, while those with primary central nervous system lymphoma were excluded. The median overall survival and progression-free survival were estimated with the Kaplan-Meier method. Univariate, bivariate, and multivariable analyses were performed using the Cox proportional hazards model. The odds ratio for refractory outcomes was calculated using logistic regression. RESULTS: A total of 2448 patients were included. The median time from diagnosis to treatment of the cohort was 19 days. When comparing median progression-free survival, median overall survival, and the 2-year overall survival between the group that started treatment within 1 week and each of the other groups individually, there was a significant difference favoring improved survival in all groups with a TDT longer than 1 week (P < .0001). These patients also had a lower odds ratio for refractory outcomes. On multivariable analysis, TDT remained an independent prognostic factor. CONCLUSION: Our study shows that a TDT equal to or less than 1 week is associated with adverse clinical factors, worse outcomes, and response in DLBCL, even after adjusting for multiple known poor prognostic factors. This was the first time that response to first-line therapy was correlated to time to treatment. Our findings support ongoing efforts to improve currently standardized prognostic tools and the incorporation of TDT into clinical trials to avoid selection bias.

Durvalumab Treatment Patterns for Patients with Unresectable Stage III Non-Small Cell Lung Cancer in the Veterans Health Administration (VHA): A Nationwide, Real-World Study.

BACKGROUND: Durvalumab is approved for the treatment of adults with unresectable stage III non-small cell lung cancer (NSCLC) post-chemoradiotherapy (CRT). This real-world study describes patient characteristics and durvalumab treatment patterns (number of doses and therapy duration; treatment initiation delays, interruptions, discontinuations, and associated reasons) among VHA-treated patients. METHODS: This was a retrospective cohort study of adults with unresectable stage III NSCLC receiving durvalumab at the VHA between 1 January 2017 and 30 June 2020. Patient characteristics and treatment patterns were presented descriptively. RESULTS: A total of 935 patients were included (median age: 69 years; 95% males; 21% Blacks; 46% current smokers; 16% ECOG performance scores ≥ 2; 50% squamous histology). Durvalumab initiation was delayed in 39% of patients (n = 367). Among the 200 patients with recorded reasons, delays were mainly due to physician preference (20%) and CRT toxicity (11%). Overall, patients received a median (interquartile range) of 16 (7-24) doses of durvalumab over 9.0 (2.9-11.8) months. Treatment interruptions were experienced by 19% of patients (n = 180), with toxicity (7.8%) and social reasons (2.6%) being the most cited reasons. Early discontinuation occurred in 59% of patients (n = 551), largely due to disease progression (24.2%) and toxicity (18.2%). CONCLUSIONS: These real-world analyses corroborate PACIFIC study results in terms of the main reasons for treatment discontinuation in a VHA population with worse prognostic factors, including older age, predominantly male sex, and poorer performance score. One of the main reasons for durvalumab initiation delays, treatment interruptions, or discontinuations was due to toxicities. Patients could benefit from improved strategies to prevent, identify, and manage CRT and durvalumab toxicities timely and effectively.

Health Equity in Patients Receiving Durvalumab for Unresectable Stage III Non-Small Cell Lung Cancer in the US Veterans Health Administration.

BACKGROUND: Real-world evidence is limited regarding the relationship between race and use of durvalumab, an immunotherapy approved for use in adults with unresectable stage III non-small cell lung cancer (NSCLC) post-chemoradiotherapy (CRT). This study aimed to evaluate if durvalumab treatment patterns differed by race in patients with unresectable stage III NSCLC in a Veterans Health Administration (VHA) population. MATERIALS AND METHODS: This was a retrospective analysis of White and Black adults with unresectable stage III NSCLC treated with durvalumab presenting to any VHA facility in the US from January 1, 2017, to June 30, 2020. Data captured included baseline characteristics and durvalumab treatment patterns, including treatment initiation delay (TID), interruption (TI), and discontinuation (TD); defined as CRT completion to durvalumab initiation greater than 42 days, greater than 28 days between durvalumab infusions, and more than 28 days from the last durvalumab dose with no new durvalumab restarts, respectively. The number of doses, duration of therapy, and adverse events were also collected. RESULTS: A total of 924 patients were included in this study (White = 726; Black = 198). Race was not a significant factor in a multivariate logistic regression model for TID (OR, 1.39; 95% CI, 0.81-2.37), TI (OR, 1.58; 95% CI, 0.90-2.76), or TD (OR, 0.84; 95% CI, 0.50-1.38). There were also no significant differences in median (interquartile range [IQR]) number of doses (White: 15 [7-24], Black: 18 [7-25]; P = .25) or median (IQR) duration of therapy (White: 8.7 months [2.9-11.8], Black: 9.8 months [3.6-12.0]; P = .08), although Black patients were less likely to experience an immune-related adverse event (28% vs. 36%, P = .03) and less likely to experience pneumonitis (7% vs. 14%, P < .01). CONCLUSION: Race was not found to be linked with TID, TI, or TD in this real-world study of patients with unresectable stage III NSCLC treated with durvalumab at the VHA.

Intranasal budesonide for rhinitis during a high airborne pollution period: a randomized controlled trial.

BACKGROUND: Air pollution may induce or reinforce nasal inflammation regardless of allergy status. There is limited direct clinical evidence informing the treatment of airborne pollution-related rhinitis. OBJECTIVE: To assess the effectiveness of intranasal budesonide in adults with self-reported rhinitis symptoms triggered/worsened by airborne pollution. METHODS: Adults in northern China with self-reported rhinitis symptoms triggered or worsened by airborne pollution were randomized to budesonide 256 µg/day or placebo for 10 days in pollution season (October 2019 to February 2020). The primary endpoint was the mean change from baseline in 24-h reflective total nasal symptom score (rTNSS) averaged over 10 days. The secondary endpoints were subject-assessed Global Impression of Change (SGIC), mean change from baseline in individual nasal symptom severity, and mean change from baseline in individual non-nasal symptoms of cough and postnasal drip severity. One-sided P < 0.0125 was considered statistically significant. RESULTS: After an interruption by COVID-19, an interim analysis showed that the study could be ended for efficacy with n = 206 participants (103/group) since the primary efficacy endpoint demonstrated significant results. The final efficacy results showed that the 10-day-averaged rTNSS change in the budesonide group was greater than with placebo (- 2.20 vs - 1.72, P = 0.0107). Budesonide also significantly improved 10-day-averaged itching/sneezing change (- 0.75 vs - 0.51, P = 0.0009). Results for SGIC and all other individual symptoms did not show significant differences between the two groups. CONCLUSIONS: Intranasal budesonide 256 µg once daily improved the total nasal symptoms and itching/sneezing over 10 days in adults with rhinitis triggered/worsened by airborne pollution.

Outcomes in chronic lymphocytic leukemia patients on novel agents in the US Veterans Health Administration System.

The US veteran population has a high proportion of chronic lymphocytic leukemia (CLL) risk factors. Using the Veterans Health Administration (VHA) population, we conducted a retrospective chart review of 1205 CLL patients who initiated treatment with a novel oral agent. For 1L ibrutinib, 33% (n = 107) discontinued therapy during the study, of which 64% discontinued due to adverse events (AEs). For relapsed/refractory (R/R) ibrutinib, 35% (n = 262) discontinued therapy, of which 63% discontinued due to AEs. For R/R venetoclax, 31% (n = 27) discontinued therapy, of which 41% were due to AEs. For idelalisib, 84% (n = 41) discontinued therapy, of which 54% were due to AEs. This real-world study suggests that AEs play an important role in dose reductions and discontinuations; however, physician inexperience in using these drugs when they were first introduced could be part of what is leading to these negative outcomes.

Program development and implementation outcomes of a statewide addiction consultation service: Maryland Addiction Consultation Service (MACS).

Background: As the opioid epidemic continues, there is a mounting sense of urgency to improve access to high-quality early identification and treatment services. However, the need is outpacing capacity in many states and effective solutions to support primary care and specialty prescribers to identify and treat more patients with opioid use disorders are still emerging. This paper describes one state's approach to increase access to medication for opioid use disorders (MOUD) through development and implementation of a statewide addiction consultation service: Maryland Addiction Consultation Service (MACS). Methods: Program components include a warmline, outreach and training, and resource and referral linkages for prescribers based on related consultation service models and documented barriers to prescribing MOUDs. Results: Initial implementation outcomes indicate service components are being adopted as intended and by the target audience; many prescribers who engaged with the service have their buprenorphine waiver (44%) but do not have any additional formal addiction training (57%). Also, statewide penetration is promising with prescriber engagement in 100% of counites, however only 33% of counties in engaged in all four types of MACS services. Most calls (61%) originated from urban counties. Conclusions: The MACS program increases access to specialty addiction medicine consultation and training through use of technology. MACS can serve as a model for other states looking to bridge the gap in access to addiction treatment.

Local Overdose Fatality Review Team Recommendations for Overdose Death Prevention.

This study compiled and detailed recommendations from Maryland Local Overdose Fatality Review Teams (LOFRTs) to provide state and local health departments with innovative strategies to address the worsening opioid epidemic and overdose-related deaths. LOFRTs consist of jurisdictional multiagency, multidisciplinary teams that share data to critically examine drug overdose cases. Goals include identification of risk factors and intervention opportunities to inform overdose prevention programs and policy. The authors qualitatively analyzed reports from Maryland LOFRTs case reviews to categorize outcomes and assess using frequency analyses. A total of 9 macro-level categories emerged from the review of approximately 361 recommendations from LOFRTs. Most recommendations related to Prevention Education, Integrated Care, and Harm Reduction strategies. Overdose fatality review is an effective means of understanding the opioid epidemic, strengthening coordinated interventions, and informing local and state health department overdose prevention strategic planning. Teams have a unique vantage point from which to view systems-level gaps and policy issues because of their collaborative nature and the quality of data provided by agencies that directly served decedents.

Assessment of Different Cetirizine Dosing Strategies on Seasonal Allergic Rhinitis Symptoms: Findings of Two Randomized Trials.

BACKGROUND: Cetirizine has been shown to be effective for relief of seasonal allergic rhinitis (SAR) symptoms. Allergic rhinitis symptoms have been reported to have circadian variations, with symptoms tending to be most bothersome overnight and in the morning. OBJECTIVE: To evaluate the effects of different cetirizine dosing schedules in comparison to twice daily (BID) chlorpheniramine and placebo on SAR symptoms at 12 and 24 hours postdose. METHODS: Study 1 subjects received cetirizine 10-mg once daily in the morning (QAM), cetirizine 10-mg once daily at bedtime (QHS), cetirizine 5-mg twice daily, or placebo. Study 2 subjects received cetirizine 5-mg QAM, cetirizine 10-mg QHS, chlorpheniramine 8-mg BID, or placebo. The primary end point was total symptom severity complex (TSSC); TSSC was the sum of symptom severity ratings averaged over the 2-week study period. Post hoc analyses of reflective symptom severity assessed in the morning (TSSCAM) and in the evening (TSSCPM) were conducted to evaluate cetirizine's effects at 12 and 24 hours postdose. RESULTS: In study 1, subject- and investigator-assessed TSSC was significantly lower in all cetirizine groups versus placebo (P ≤ .003). In study 2, subject-assessed TSSC was significantly lower in all cetirizine groups versus placebo (P ≤ .04) and was numerically lower for investigator-assessed TSSC. Post hoc analyses demonstrated that cetirizine significantly improved TSSCAM at 12 and 24 hours postdose versus placebo in both studies regardless of dosing schedule. TSSCPM significantly improved at 12 and 24 hours postdose in all study 1 cetirizine groups versus placebo. In study 2, versus placebo, TSSCPM significantly improved at 12 hours postdose in cetirizine 5-mg QAM group and numerically improved at 24 hours postdose in cetirizine 10-mg QHS group. CONCLUSION: Regardless of dosing regimen, cetirizine demonstrates effective 24-hour relief of SAR symptoms, particularly on TSSCAM, which assesses overnight and early morning symptom control.

Time of day but not aging regulates 5-HT7 receptor binding sites in the hamster hippocampus.

Activation of 5-HT7 receptors influences memory as well as circadian rhythms and other processes. This study investigated the regulation of the 5-HT7 receptors in the hippocampus, a likely substrate for the effects of 5-HT7 receptor compounds on memory. Because endogenous serotonin release is higher during the active phase, and chronic treatment with a serotonin-selective reuptake inhibitor down-regulates 5-HT7 receptors, we hypothesized that 5-HT7 receptors exhibit 24-h variations. We also hypothesized that aging decreases 5-HT7 receptors in the hippocampus, as it does in the dorsal raphe nucleus, a brain site for serotonergic resetting of circadian rhythms. Male hamsters (young, 3-5 mos; old, 17-21 mos) exposed to a light:dark cycle were euthanized at 4 times of day (zeitgeber times [ZT]1, 6, 13, & 19; ZT12=time of lights:off). 5-HT7 receptor autoradiography was conducted on hippocampal sections using [3H]8-OH-DPAT [2nM] as the radioligand and SB-269970 [1µM] to define nonspecific binding. Slide-mounted sections and radioactive standards were apposed to X-ray films; the resultant autoradiograms were assessed by computer-assisted microdensitometry. Specific 5-HT7 receptor binding was robustly expressed in the dentate gyrus (DG) and CA1 but not in the CA2 or CA3. In the CA1 and DG, specific 5-HT7 receptor binding exhibited 24-h rhythms with troughs at night (P<0.005; P<0.05, respectively). Aging did not significantly affect specific 5-HT7 receptor binding in these regions, nor were significant time and age interactions observed. These findings suggest that the therapeutic effectiveness of 5-HT7 drugs may vary with time of day of administration but not with the age of the recipient.

Improving the baculovirus expression vector system with vankyrin-enhanced technology.

The baculovirus expression vector system (BEVS) is a widely used platform for the production of recombinant eukaryotic proteins. However, the BEVS has limitations in comparison to other higher eukaryotic expression systems. First, the insect cell lines used in the BEVS cannot produce glycoproteins with complex-type N-glycosylation patterns. Second, protein production is limited as cells die and lyse in response to baculovirus infection. To delay cell death and lysis, we transformed several insect cell lines with an expression plasmid harboring a vankyrin gene (P-vank-1), which encodes an anti-apoptotic protein. Specifically, we transformed Sf9 cells, Trichoplusia ni High FiveTM cells, and SfSWT-4 cells, which can produce glycoproteins with complex-type N-glycosylation patterns. The latter was included with the aim to increase production of glycoproteins with complex N-glycans, thereby overcoming the two aforementioned limitations of the BEVS. To further increase vankyrin expression levels and further delay cell death, we also modified baculovirus vectors with the P-vank-1 gene. We found that cell lysis was delayed and recombinant glycoprotein yield increased when SfSWT-4 cells were infected with a vankyrin-encoding baculovirus. A synergistic effect in elevated levels of recombinant protein production was observed when vankyrin-expressing cells were combined with a vankyrin-encoding baculovirus. These effects were observed with various model proteins including medically relevant therapeutic proteins. In summary, we found that cell lysis could be delayed and recombinant protein yields could be increased by using cell lines constitutively expressing vankyrin or vankyrin-encoding baculovirus vectors. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1496-1507, 2017.

Randomized, placebo-controlled study of cetirizine and loratadine in children with seasonal allergic rhinitis.

BACKGROUND: Pharmacologic treatment is a mainstay of allergy therapy and many caregivers use over-the-counter antihistamines for the treatment of seasonal allergic rhinitis (SAR) symptoms in children. OBJECTIVE: To assess the efficacy and safety of cetirizine 10 mg syrup versus loratadine 10 mg syrup versus placebo syrup in a randomized double-blind study of children, ages 6-11 years, with SAR. METHODS: This randomized, double-blind, parallel-group, placebo-controlled study was conducted at 71 U.S. centers during the spring tree and grass pollen season. After a 1-week placebo run-in period, qualified subjects were randomized to once-daily cetirizine 10 mg (n = 231), loratadine 10 mg (n = 221), and placebo (n = 231) for 2 weeks. The primary efficacy end point was change from baseline in the subject's mean reflective total symptom severity complex (TSSC) score over 14 days. RESULTS: Children treated with cetirizine experienced significantly greater TSSC score reductions versus children treated with placebo over 14 days (least square mean change, -2.1 versus -1.6; p = 0.006). The differences in TSSC score improvement over 14 days between the cetirizine versus loratadine groups (-2.1 versus -1.8; p = 0.124) and between the loratadine versus placebo groups (-1.8 versus -1.6; p = 0.230) were not statistically significant. Predominant adverse events in the cetirizine, loratadine, and placebo groups were headache (3.5, 3.6, and 3.1%, respectively) and pharyngitis (3.5, 2.7, and 3.5%, respectively). Somnolence was reported in three subjects (1.3%) treated with cetirizine and in none of the other subjects. CONCLUSION: Cetirizine 10 mg was statistically significantly more efficacious than placebo in the treatment of SAR symptoms in children ages 6-11 years. Symptom improvement was not significantly different between the loratadine 10 mg and placebo groups.

Incorporation of poison center services in a state-wide overdose education and naloxone distribution program.

BACKGROUND: To help curb the opioid overdose epidemic, many states are implementing overdose education and naloxone distribution (OEND) programs. Few evaluations of these programs exist. Maryland's OEND program incorporated the services of the poison center. It asked bystanders to call the poison center within 2 hours of administration of naloxone. Bystanders included law enforcement (LE). OBJECTIVE: Description of the initial experience with this unique OEND program component. METHODS: Retrospective case series of all cases of bystander-administered naloxone reported to the Maryland Poison Center over 16 months. Cases were followed to final outcome, for example, hospital discharge or death. Indications for naloxone included suspected opioid exposure and unresponsiveness, respiratory depression, or cyanosis. Naloxone response was defined as person's ability to breathe, talk, or walk within minutes of administration. RESULTS: Seventy-eight cases of bystander-administered naloxone were reported. Positive response to naloxone was observed in 75.6% of overall cases. Response rates were 86.1% and 70.9% for suspected exposures to heroin and prescription opioids, respectively. Two individuals failed to respond to naloxone and died. DISCUSSION: Naloxone response rates were higher and admission to the intensive care unit rates were lower in heroin overdoses than prescription opioid overdoses. CONCLUSIONS: This retrospective case series of 78 cases of bystander-administered naloxone reports a 75.6% overall rate of reversal. SCIENTIFIC SIGNIFICANCE: The findings of this study may be more generalizable. Incorporation of poison center services facilitated the capture of more timely data not usually available to OEND programs. (Am J Addict 2016;25:301-306).

Development of Maryland Local Overdose Fatality Review Teams: A Localized, Interdisciplinary Approach to Combat the Growing Problem of Drug Overdose Deaths.

The Maryland Local Overdose Fatality Review Teams (LOFRTs) are multiagency, multidisciplinary teams that critically analyze individual cases of drug overdose in their jurisdictions to identify preventable risk factors and missed opportunities for intervention, and to make policy and programmatic recommendations to prevent future overdose deaths. Three Maryland LOFRTs were first piloted in early 2014, and became established in law in May of the same year. LOFRTs provide unique opportunities for enhanced interagency collaboration and locally driven prevention efforts. This study describes the process of establishing LOFRTs in Maryland. The experiences and information regarding LOFRTs may help counties in other states combat the growing problem of deaths by drug overdose.

Sharing Overdose Data Across State Agencies to Inform Public Health Strategies: A Case Study.

Data sharing and analysis are important components of coordinated and cost-effective public health strategies. However, legal and policy barriers have made data from different agencies difficult to share and analyze for policy development. To address a rise in overdose deaths, Maryland used an innovative and focused approach to bring together data on overdose decedents across multiple agencies. The effort was focused on developing discrete intervention points based on information yielded on decedents' lives, such as vulnerability upon release from incarceration. Key aspects of this approach included gubernatorial leadership, a unified commitment to data sharing across agencies with memoranda of understanding, and designation of a data management team. Preliminary results have yielded valuable insights and have helped inform policy. This process of navigating legal and privacy concerns in data sharing across multiple agencies may be applied to a variety of public health problems challenging health departments across the country.

Effect of cetirizine on symptom severity and quality of life in perennial allergic rhinitis.

The effect of cetirizine on quality of life (QOL) in subjects with perennial allergic rhinitis (PAR) has been previously evaluated using generic instruments. While generic QOL tools are used across various conditions, disease-specific instruments evaluate the impact of treatment on areas that are affected by that particular condition. This study evaluated the effect of cetirizine on symptom severity and health-related QOL, using a disease-specific instrument, in adults with PAR. This randomized, double-blind, placebo-controlled study was conducted at 15 U.S. centers outside the pollen allergy season. After a 1-week placebo run-in period, qualified subjects aged 18-65 years with PAR were randomized to once-daily cetirizine 10 mg (n = 158) or placebo (n = 163) for 4 weeks. Change from baseline in total symptom severity complex (TSSC) and overall Rhinitis Quality of Life Questionnaire (RQLQ) scores were primary efficacy end points. Cetirizine produced significantly greater improvements in mean TSSC for each treatment week (p < 0.05) and for the entire 4-week treatment period (p = 0.005) compared with placebo. After 4 weeks, cetirizine-treated subjects reported significantly greater overall improvement in RQLQ scores compared with placebo-treated subjects (p = 0.004). After 1 week, cetirizine produced significant improvements in the nasal symptoms, practical problems, and activities RQLQ domain scores compared with placebo (p < 0.05). After 4 weeks, cetirizine-treated subjects reported significant reductions in these RQLQ domain scores and in emotion domain scores compared with placebo-treated subjects (p < 0.05). Cetirizine 10 mg daily produced significant improvements in symptom severity and allergic rhinitis-related QOL compared with placebo in adults with PAR.

Circadian rhythm disruption by a novel running wheel: roles of exercise and arousal in blockade of the luteinizing hormone surge.

Exposure of proestrous Syrian hamsters to a new room, cage, and novel running wheel blocks the luteinizing hormone (LH) surge until the next day in ~75% of hamsters [1]. The studies described here tested the hypotheses that 1) exercise and/or 2) orexinergic neurotransmission mediate novel wheel blockade of the LH surge and circadian phase advances. Female hamsters were exposed to a 14L:10D photoperiod and activity rhythms were monitored with infra-red detectors. In Expt. 1, to test the effect of exercise, hamsters received jugular cannulae and on the next day, proestrus (Day 1), shortly before zeitgeber time 5 (ZT 5, 7h before lights-off) the hamsters were transported to the laboratory. After obtaining a blood sample at ZT 5, the hamsters were transferred to a new cage with a novel wheel that was either freely rotating (unlocked), or locked until ZT 9, and exposed to constant darkness (DD). Blood samples were collected hourly for 2days from ZT 5-11 under red light for determination of plasma LH levels by radioimmunoassay. Running rhythms were monitored continuously for the next 10-14days. The locked wheels were as effective as unlocked wheels in blocking LH surges (no Day 1 LH surge in 6/9 versus 8/8 hamsters, P>0.05) and phase advances in the activity rhythms did not differ between the groups (P=0.28), suggesting that intense exercise is not essential for novel wheel blockade and phase advance of the proestrous LH surge. Expt. 2 tested whether orexin neurotransmission is essential for these effects. Hamsters were treated the same as those in Expt. 1 except that they were injected (i.p.) at ZT 4.5 and 5 with either the orexin 1 receptor antagonist SB334867 (15mg/kg per injection) or vehicle (25% DMSO in 2-hydroxypropyl-beta-cyclodextrin (HCD)). SB-334867 inhibited novel wheel blockade of the LH surge (surges blocked in 2/6 SB334867-injected animals versus 16/18 vehicle-injected animals, P<0.02) and also inhibited wheel running and circadian phase shifts, indicating that activation of orexin 1 receptors is necessary for these effects. Expt. 3 tested the hypothesis that novel wheel exposure activates orexin neurons. Proestrous hamsters were transferred at ZT 5 to a nearby room within the animal facility and were exposed to a new cage with a locked or unlocked novel wheel or left in their home cages. At ZT 8, the hamsters were anesthetized, blood was withdrawn, they were perfused with fixative and brains were removed for immunohistochemical localization of Fos, GnRH, and orexin. Exposure to a wheel, whether locked or unlocked, suppressed circulating LH concentrations at ZT 8, decreased the proportion of Fos-activated GnRH neurons, and increased Fos-immunoreactive orexin cells. Unlocked wheels had greater effects than locked wheels on all three endpoints. Thus in a familiar environment, exercise potentiated the effect of the novel wheel on Fos expression because a locked wheel was not a sufficient stimulus to block the LH surge. In conclusion, these studies indicate that novel wheel exposure activates orexin neurons and that blockade of orexin 1 receptors prevents novel wheel blockade of the LH surge. These findings are consistent with a role for both exercise and arousal in mediating novel wheel blockade of the LH surge.

Influence of aging on Bmal1 and Per2 expression in extra-SCN oscillators in hamster brain.

Deletion of the core clock gene, Bmal1, ablates circadian rhythms and accelerates aging, leading to cognitive deficits and tissue atrophy (e.g., skeletal muscle) (Kondratov et al., 2006, Kondratova et al., 2010). Although normal aging has been shown to attenuate Bmal1 expression in the master circadian pacemaker in the suprachiasmatic nucleus (SCN), relatively little is known about age-related changes in Bmal1 expression in other tissues, where Bmal1 may have multiple functions. This study tested the hypothesis that aging reduces Bmal1 expression in extra-SCN oscillators including brain substrates for memory and in skeletal muscle. Brains and gastrocnemius muscles were collected from young (3-5 months) and old hamsters (17-21 months) euthanized at four times of day. Bmal1 mRNA expression was determined by conducting in situ hybridization on brain sections or real-time PCR on muscle samples. The results showed age-related attenuation of Bmal1 expression in many brain regions, and included loss of diurnal rhythms in the hippocampal CA2 and CA3 subfields, but no change in muscle. In situ hybridization for Per2 mRNA was also conducted and showed age-related reduction of diurnal rhythm amplitude selectively in the hippocampal CA1 and DG subfields. In conclusion, aging has tissue-dependent effects on Bmal1 expression in extra-SCN oscillators. These finding on normal aging will provide a reference for comparing potential changes in Bmal1 and Per2 expression in age-related pathologies. In conjunction with previous reports, the results suggest the possibility that attenuation of clock gene expression in some brain regions (the hippocampus, cingulate cortex and SCN) may contribute to age-related cognitive deficits.

Distinct phase relationships between suprachiasmatic molecular rhythms, cerebral cortex molecular rhythms, and behavioral rhythms in early runner (CAST/EiJ) and nocturnal (C57BL/6J) mice.

STUDY OBJECTIVE: We have previously established that CAST/EiJ (CAST) mice differ from normal mice, such as C57BL/6J (B6), in the timing of wheel-running onset relative to light/dark cycles. These mice provide an animal model for studies of the genetic and neurobiological basis for circadian phase misalignment in humans. Neither differences in endogenous circadian period nor the shape of the photic phase response curve explain the difference in the timing of activity onset between CAST and B6 mice, suggesting a mechanism downstream of the circadian clock. Here, we further test the hypothesis that the two strains differ with respect to circadian oscillations at the molecular level. DESIGN: Sleep/wake cycles were examined and rhythms of Period1 (Per1) and Period2 (Per2) expression were measured in the cerebral cortex, suprachiasmatic nucleus (SCN), and other hypothalamic regions. SETTING: Basic sleep and molecular research laboratory. PATIENTS OR PARTICIPANTS: Male mice of the B6 and CAST inbred strains. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Sleep/wake cycles were advanced by approximately 4 h in CAST mice relative to B6 mice. This was paralleled by phase-advanced rhythms of Per1 and Per2 expression, as measured byin situ hybridization, in the cerebral cortex of CAST relative to B6. By contrast, the timing of circadian oscillations and the photic induction ofPer1 and Per2 expression in the SCN were unaffected by strain. CONCLUSION: The advanced phase of wheel running and sleep/wake cycles in CAST mice relative to B6 mice is apparently not associated with differences in molecular oscillations in the SCN clock itself, but most likely in mechanisms downstream of the SCN clock. CAST mice may therefore provide a model system to investigate circadian downstream mechanisms underlying unusual patterns of entrainment to the ambient photoperiod. CITATION: Jiang P; Franklin KM; Duncan MJ; O'Hara BF; Wisor JP. Distinct phase relationships between suprachiasmatic molecular rhythms, cerebral cortex molecular rhythms, and behavioral rhythms in early runner (CAST/EiJ) and nocturnal (C57BL/6J) mice. SLEEP 2012;35(10):1385-1394.