Impaired aldehyde detoxification exacerbates motor deficits in an alpha-synuclein mouse model of Parkinson's disease

INTRODUCTION

The discovery of biogenic aldehydes in the postmortem parkinsonian brain and the ability of these aldehydes to modify and cross-link proteins has called attention to their possible role in Parkinson's disease. For example, many in vitro studies have found that the aldehyde metabolite of dopamine, 3,4-dihydroxyphenylacetaldehyde (DOPAL), induces the formation of stable, neurotoxic alpha-synuclein oligomers.

METHODS

To study this in vivo, mice deficient in the two aldehyde dehydrogenase enzymes (Aldh1a1 and Aldh2, DKO) primarily responsible for detoxification of DOPAL in the nigrostriatal pathway were crossed with mice that overexpress human wild-type alpha-synuclein. DKO overexpressing human wild-type alpha-synuclein (DKO/ASO) offspring were evaluated for impairment on motor tasks associated with Parkinsonism.

RESULTS

DKO/ASO mice developed severe motor deficits greater than that of mice overexpressing human wild-type alpha-synuclein alone.

CONCLUSION

These results provide evidence to support the idea that biogenic aldehydes such as DOPAL interact with human wild-type alpha-synuclein, directly or indirectly, in vivo to exacerbate locomotor deficits in Parkinson's disease.

L-type calcium channel antagonist isradipine age-dependently decreases plaque associated dystrophic neurites in 5XFAD mouse model

Epidemiological studies suggest that L-type calcium channel (LTCC) antagonists may reduce the incidence of age-associated neurodegenerative diseases including Alzheimer's disease (AD). However, the neuroprotective mechanism of LTCC antagonists is unknown. Amyloid-β (Aβ) pathology disrupts intracellular calcium signaling, which regulates lysosomes and microglial responses. Neurons near Aβ plaques develop dystrophic neurites, which are abnormal swellings that accumulate lysosomes. Further, microglia accumulate around Aβ plaques and secrete inflammatory cytokines. We hypothesized that antagonism of LTCCs with isradipine would reduce Aβ plaque-associated dystrophic neurites and inflammatory microglia in the 5XFAD mouse model by restoring normal intracellular calcium regulation. To test this hypothesis, we treated 6- and 9-month-old 5XFAD mice with isradipine and tested behavior, examined Aβ plaques, microglia, and dystrophic neurites. We found that isradipine treatment age-dependently reduces dystrophic neurites and leads to trending decreases in Aβ but does not modulate plaque associated microglia regardless of age. Our findings provide insight into how antagonizing LTCCs alters specific cell types in the Aβ plaque environment, providing valuable information for potential treatment targets in future AD studies.

San Antonio Nathan Shock Center: your one-stop shop for aging research

With evolving cores, enrichment and training programs, and supported research projects, the San Antonio (SA) Nathan Shock Center has for 26 years provided critical support to investigators locally, nationally, and abroad. With its existing and growing intellectual capital, the SA Nathan Shock Center provides to local and external investigators an enhanced platform to conduct horizontally integrated (lifespan, healthspan, pathology, pharmacology) transformative research in the biology of aging, and serves as a springboard for advanced educational and training activities in aging research. The SA Nathan Shock Center consists of six cores: Administrative/Program Enrichment Core, Research Development Core, Aging Animal Models and Longevity Assessment Core, Pathology Core, Analytical Pharmacology and Drug Evaluation Core, and Integrated Physiology of Aging Core. The overarching goal of the SA Nathan Shock Center is to advance knowledge in the basic biology of aging and to identify molecular and cellular mechanisms that will facilitate the development of pharmacologic interventions and other strategies to extend healthy lifespan. In pursuit of this goal, we provide an innovative "one-stop shop" venue to accelerate transformative research in the biology of aging through our integrated research cores. Moreover, we aim to foster and promote career development of early-stage investigators in aging biology through our research development programs, to serve as a resource and partner to investigators from other Shock Centers, and to disseminate scientific knowledge and enhanced awareness about aging research. Overall, the SA Nathan Shock Center aims to be a leader in research that advances our understanding of the biology of aging and development of approaches to improve longevity and healthy aging.

Mixed-methods trial of a phosphatidylethanol-based contingency management intervention to initiate and maintain alcohol abstinence in formerly homeless adults with alcohol use disorders

Background

Contingency management (CM) is an intervention where incentives are provided in exchange for biochemically confirmed alcohol abstinence. CM is effective at initiating alcohol abstinence, but it is less effective at maintaining long-term abstinence. Phosphatidylethanol (PEth), collected via a finger-stick, can detect alcohol use for 14–28 days. PEth allows for the development of a CM model that includes increasingly less frequent monitoring of abstinence to assist high risk groups, such as formerly homeless individuals, maintain long-term abstinence.

Aims

Investigate whether PEth-based CM intervention targeting alcohol abstinence in formerly homeless, currently housed individuals with alcohol use disorders is: (1) acceptable and feasible for housing program tenants and personnel; and is associated with increased (2) alcohol abstinence and (3) housing tenure.

Methods

Acceptability and feasibility will be assessed using a QUAL+quant mixed-methods design using qualitative interviews and quantitative measures of satisfaction and attrition. Effectiveness will be evaluated through a randomized pilot trial of 50 study participants who will receive 6 months of either treatment as usual (TAU) including incentives (e.g., gift cards) for providing blood samples (Control Condition) or TAU and incentives for negative PEth results (PEth-CM Condition). Outcomes will be assessed during the intervention and at a three-month follow-up visit. The trial will be conducted via telehealth as a result of COVID-19.

Discussion

This protocol seeks to utilize a novel alcohol biomarker to evaluate the acceptability, feasibility, and initial effectiveness of a CM model that encourages long-term abstinence in a high-risk group.

Rapamycin enhances BCG-specific γδ T cells during intravesical BCG therapy for non-muscle invasive bladder cancer: a randomized, double-blind study

BACKGROUND

Although intravesical BCG is the standard treatment of high-grade non-muscle invasive bladder cancer (NMIBC), response rates remain unsatisfactory. In preclinical models, rapamycin enhances BCG vaccine efficacy against tuberculosis and the killing capacity of γδ T cells, which are critical for BCG's antitumor effects. Here, we monitored immunity, safety, and tolerability of rapamycin combined with BCG in patients with NMIBC.

METHODS

A randomized double-blind trial of oral rapamycin (0.5 or 2.0 mg daily) versus placebo for 1 month was conducted in patients with NMIBC concurrently receiving 3 weekly BCG instillations (NCT02753309). The primary outcome was induction of BCG-specific γδ T cells, measured as a percentage change from baseline. Post-BCG urinary cytokines and immune cells were examined as surrogates for local immune response in the bladder. Secondary outcomes measured were adverse events (AEs) and tolerability using validated patient-reported questionnaires.

RESULTS

Thirty-one patients were randomized (11 placebo, 8 rapamycin 2.0 mg, and 12 rapamycin 0.5 mg). AEs were similar across groups and most were grade 1-2. One (12.5%) patient randomized to 2.0 mg rapamycin was taken off treatment due to stomatitis. No significant differences in urinary symptoms, bowel function, or bother were observed between groups. The median (IQR) percentage change in BCG-specific γδ T cells from baseline per group was as follows: -26% (-51% to 24%) for placebo, 9.6% (-59% to 117%) for rapamycin 0.5 mg (versus placebo, p=0.18), and 78.8% (-31% to 115%) for rapamycin 2.0 mg (versus placebo, p=0.03). BCG-induced cytokines showed a progressive increase in IL-8 (p=0.02) and TNF-α (p=0.04) over time for patients on rapamycin 2.0 mg, whereas patients receiving placebo had no significant change in urinary cytokines. Compared with placebo, patients receiving 2.0 mg rapamycin had increased urinary γδ T cells at the first week of BCG (p=0.02).

CONCLUSIONS

Four weeks of 0.5 and 2.0 mg oral rapamycin daily is safe and tolerable in combination with BCG for patients with NMIBC. Rapamycin enhances BCG-specific γδ T cell immunity and boosts urinary cytokines during BCG treatment. Further study is needed to determine long-term rapamycin safety, tolerability and effects on BCG efficacy.

Acarbose improved survival for Apc+/Min mice

Acarbose blocks the digestion of complex carbohydrates, and the NIA Intervention Testing Program (ITP) found that it improved survival when fed to mice. Yet, we do not know if lifespan extension was caused by its effect on metabolism with regard to the soma or cancer suppression. Cancer caused death for ~80% of ITP mice. The ITP found rapamycin, an inhibitor to the pro-growth mTORC1 (mechanistic target of rapamycin complex 1) pathway, improved survival and it suppressed tumors in Apc+/Min mice providing a plausible rationale to ask if acarbose had a similar effect. Apc+/Min is a mouse model prone to intestinal polyposis and a mimic of familial adenomatous polyposis in people. Polyp-associated anemia contributed to their death. To address this knowledge gap, we fed two doses of acarbose to Apc+/Min mice. Acarbose improved median survival at both doses. A cross-sectional analysis was performed next. At both doses, ACA fed mice exhibited reduced intestinal crypt depth, weight loss despite increased food consumption and reduced postprandial blood glucose and plasma insulin, indicative of improved insulin sensitivity. Dose-independent and dose-dependent compensatory liver responses were observed for AMPK and mTORC1 activities, respectively. Only mice fed the high dose diet exhibited reductions in tumor number with higher hematocrits. Because low-dose acarbose improved lifespan but failed to reduced tumors, its effects seem to be independent of cancer. These data implicate the importance of improved carbohydrate metabolism on survival.

Evaluation of the pharmacokinetics of metformin and acarbose in the common marmoset

Metformin has beneficial effects on several age-related diseases (e.g., diabetes, obesity, cancer) and extends lifespan in nematodes and mice. Acarbose, an FDA-approved agent for treating type 2 diabetes, prevents breakdown of complex carbohydrates. Both compounds have been suggested as potential anti-aging interventions and acarbose has been shown to extend mouse longevity by the Intervention Testing Program (ITP). One potential next step is to assess the effect of these interventions on healthspan and lifespan in non-human primates. The common marmoset (Callithrix jacchus) is a small new world monkey with a relatively short life span and small size, both valuable for the translation potential of this nonhuman primate species for the study of aging and chronic disease. However, the dosing and assessment of potential side effects of either metformin or acarbose in this species have yet to be assessed. This study evaluated the pharmacokinetics of two dosage levels each of metformin or acarbose (given separately) in two small groups of young marmosets (n = 5/group) treated for 24 h to define the pharmacokinetics of each drug. The ability to rapidly and reliably dose socially housed marmosets with an oral form of acarbose or metformin that is well tolerated indicates that this species is a reliable model for testing acarbose and metformin in a safe and efficient way in a long-term intervention.

Glycine supplementation extends lifespan of male and female mice

Diets low in methionine extend lifespan of rodents, though through unknown mechanisms. Glycine can mitigate methionine toxicity, and a small prior study has suggested that supplemental glycine could extend lifespan of Fischer 344 rats. We therefore evaluated the effects of an 8% glycine diet on lifespan and pathology of genetically heterogeneous mice in the context of the Interventions Testing Program. Elevated glycine led to a small (4%-6%) but statistically significant lifespan increase, as well as an increase in maximum lifespan, in both males (p = 0.002) and females (p < 0.001). Pooling across sex, glycine increased lifespan at each of the three independent sites, with significance at p = 0.01, 0.053, and 0.03, respectively. Glycine-supplemented females were lighter than controls, but there was no effect on weight in males. End-of-life necropsies suggested that glycine-treated mice were less likely than controls to die of pulmonary adenocarcinoma (p = 0.03). Of the 40 varieties of incidental pathology evaluated in these mice, none were increased to a significant degree by the glycine-supplemented diet. In parallel analyses of the same cohort, we found no benefits from TM5441 (an inhibitor of PAI-1, the primary inhibitor of tissue and urokinase plasminogen activators), inulin (a source of soluble fiber), or aspirin at either of two doses. Our glycine results strengthen the idea that modulation of dietary amino acid levels can increase healthy lifespan in mice, and provide a foundation for further investigation of dietary effects on aging and late-life diseases.

Rapamycin Prevents Surgery-Induced Immune Dysfunction in Patients with Bladder Cancer

The mechanistic target of rapamycin (mTOR) integrates environmental inputs to regulate cellular growth and metabolism in tumors. However, mTOR also regulates T-cell differentiation and activation, rendering applications of mTOR inhibitors toward treating cancer complex. Preclinical data support distinct biphasic effects of rapamycin, with higher doses directly suppressing tumor cell growth and lower doses enhancing T-cell immunity. To address the translational relevance of these findings, the effects of the mTOR complex 1 (mTORC1) inhibitor, rapamycin, on tumor and T cells were monitored in patients undergoing cystectomy for bladder cancer. MB49 syngeneic murine bladder cancer models were tested to gain mechanistic insights. Surgery-induced T-cell exhaustion in humans and mice and was associated with increased pulmonary metastasis and decreased PD-L1 antibody efficacy in mouse bladder cancer. At 3 mg orally daily, rapamycin concentrations were 2-fold higher in bladder tissues than in blood. Rapamycin significantly inhibited tumor mTORC1, shown by decreased rpS6 phosphorylation in treated versus control patients (P = 0.008). Rapamycin reduced surgery-induced T-cell exhaustion in patients, evidenced by a significant decrease in the prevalence of dysfunctional programmed death-1 (PD-1)-expressing T cells. Grade 3 to 4 adverse event rates were similar between groups, but rapamycin-treated patients had a higher rate of wound complications versus controls. In conclusion, surgery promoted bladder cancer metastasis and decreased the efficacy of postoperative bladder cancer immunotherapy. Low-dose (3 mg daily) oral rapamycin has favorable pharmacodynamic and immune modulating activity in surgical patients and has the potential to decrease surgery-induced immune dysfunction.

Low-dose rapamycin extends lifespan in a mouse model of mtDNA depletion syndrome

Mitochondrial disorders affecting oxidative phosphorylation (OxPhos) are caused by mutations in both the nuclear and mitochondrial genomes. One promising candidate for treatment is the drug rapamycin, which has been shown to extend lifespan in multiple animal models, and which was previously shown to ameliorate mitochondrial disease in a knock-out mouse model lacking a nuclear-encoded gene specifying an OxPhos structural subunit (Ndufs4). In that model, relatively high-dose intraperitoneal rapamycin extended lifespan and improved markers of neurological disease, via an unknown mechanism. Here, we administered low-dose oral rapamycin to a knock-in (KI) mouse model of authentic mtDNA disease, specifically, progressive mtDNA depletion syndrome, resulting from a mutation in the mitochondrial nucleotide salvage enzyme thymidine kinase 2 (TK2). Importantly, low-dose oral rapamycin was sufficient to extend Tk2^KI/KI mouse lifespan significantly, and did so in the absence of detectable improvements in mitochondrial dysfunction. We found no evidence that rapamycin increased survival by acting through canonical pathways, including mitochondrial autophagy. However, transcriptomics and metabolomics analyses uncovered systemic metabolic changes pointing to a potential ‘rapamycin metabolic signature.’ These changes also implied that rapamycin may have enabled the Tk2^KI/KI mice to utilize alternative energy reserves, and possibly triggered indirect signaling events that modified mortality through developmental reprogramming. From a therapeutic standpoint, our results support the possibility that low-dose rapamycin, while not targeting the underlying mtDNA defect, could represent a crucial therapy for the treatment of mtDNA-driven, and some nuclear DNA-driven, mitochondrial diseases.

Rapamycin prevents surgery-induced T cell exhaustion in patients with bladder cancer

The mechanistic target of rapamycin (mTOR) integrates environmental inputs to regulate cellular growth and metabolism in tumors. However, mTOR also regulates T cell differentiation and activation, rendering applications of mTOR inhibitors towards treating cancer complex. Recent preclinical data supports distinct biphasic effects of rapamycin with higher doses directly suppressing tumor cell growth and lower doses enhancing T cell immunity. We conducted a randomized controlled pre-surgical clinical trial to study the tumor and immune effects of low dose mTOR complex 1 inhibition with rapamycin for patients with invasive, non-metastatic bladder cancer. At 3 mg daily for four weeks, rapamycin significantly inhibited tumor mTORC1 (ribosomal protein S6 phosphorylation), and achieved high bladder tissue levels. Rapamycin also reduced surgery-mediated T cell exhaustion, evidenced by a significant decrease in the prevalence of dysfunctional programmed death-1 (PD-1) expressing circulating T cells without decreasing T cell proliferation or cytokine production. In mice challenged with MB49 orthotopic bladder tumors, a 2 cm surgical laparotomy reduces the efficacy of α-PD-L1 immunotherapy but efficacy can be partly restored with presurgical administration of rapamycin. These findings support favorable delivery, pharmacodynamic activity, and immune modulatory profile of low dose rapamycin in bladder cancer and identifies a novel role for mTOR inhibition in modulating surgery-induced immune dysfunction.

mTOR drives cerebral blood flow and memory deficits in LDLR-/- mice modeling atherosclerosis and vascular cognitive impairment

We recently showed that mTOR attenuation blocks progression and abrogates established cognitive deficits in Alzheimer's disease (AD) mouse models. These outcomes were associated with the restoration of cerebral blood flow (CBF) and brain vascular density (BVD) resulting from relief of mTOR inhibition of NO release. Recent reports suggested a role of mTOR in atherosclerosis. Because mTOR drives aging and vascular dysfunction is a universal feature of aging, we hypothesized that mTOR may contribute to brain vascular and cognitive dysfunction associated with atherosclerosis. We measured CBF, BVD, cognitive function, markers of inflammation, and parameters of cardiovascular disease in LDLR-/- mice fed maintenance or high-fat diet ± rapamycin. Cardiovascular pathologies were proportional to severity of brain vascular dysfunction. Aortic atheromas were reduced, CBF and BVD were restored, and cognitive dysfunction was attenuated potentially through reduction in systemic and brain inflammation following chronic mTOR attenuation. Our studies suggest that mTOR regulates vascular integrity and function and that mTOR attenuation may restore neurovascular function and cardiovascular health. Together with our previous studies in AD models, our data suggest mTOR-driven vascular damage may be a mechanism shared by age-associated neurological diseases. Therefore, mTOR attenuation may have promise for treatment of cognitive impairment in atherosclerosis.

Pilot investigation of a phosphatidylethanol-based contingency management intervention targeting alcohol use

Phosphatidylethanol (PEth) can be detected in blood from 14 to as many as 28 days after alcohol consumption, depending on the amount and frequency of alcohol consumed. PEth may have utility for verifying abstinence in a contingency management (CM) intervention for alcohol use, particularly in settings where frequent verification of abstinence is impossible or impractical. Five nontreatment-seeking heavy drinkers (40% men) participated in an 11-week, ABA-phased within-subject experiment for which they submitted blood spots for PEth measurement, urine samples for ethyl glucuronide (EtG) testing, and self-report drinking data weekly. Participants received reinforcers for submitting samples throughout the A phases. During the B phase (CM phase), they received additional reinforcers when their PEth level was reduced from the previous week and was verified by a negative EtG (<150 ng/ml) urine test and self-report. PEth, EtG, and self-report outcomes were compared between A phases (Weeks 1-3, 8-11) and B phases (Weeks 4-7). During the A phases, 23% of PEth results indicated alcohol abstinence, whereas 53% of PEth samples submitted during the CM (B phase) indicated alcohol abstinence. Participants were more likely to submit EtG-negative urine samples and report lower levels of drinking and heavy drinking during the B phase, relative to the A phases. We also explored the ability of PEth to detect self-reported drinking. The combined PEth homologs (16:0/18:1 and 16:0/18:2) predicted self-reported drinking with area under the curve from 0.81 (1 week) to 0.80 (3 weeks). Results support the initial feasibility of a Peth-based CM intervention. (PsycINFO Database Record

Adaptations to chronic rapamycin in mice

Rapamycin inhibits mechanistic (or mammalian) target of rapamycin (mTOR) that promotes protein production in cells by facilitating ribosome biogenesis (RiBi) and eIF4E-mediated 5'cap mRNA translation. Chronic treatment with encapsulated rapamycin (eRapa) extended health and life span for wild-type and cancer-prone mice. Yet, the long-term consequences of chronic eRapa treatment are not known at the organ level. Here, we report our observations of chronic eRapa treatment on mTORC1 signaling and RiBi in mouse colon and visceral adipose. As expected, chronic eRapa treatment decreased detection of phosphorylated mTORC1/S6K substrate, ribosomal protein (rpS6) in colon and fat. However, in colon, contrary to expectations, there was an upregulation of 18S rRNA and some ribosomal protein genes (RPGs) suggesting increased RiBi. Among RPGs, eRapa increases rpl22l1 mRNA but not its paralog rpl22. Furthermore, there was an increase in the cap-binding protein, eIF4E relative to its repressor 4E-BP1 suggesting increased translation. By comparison, in fat, there was a decrease in the level of 18S rRNA (opposite to colon), while overall mRNAs encoding ribosomal protein genes appeared to increase, including rpl22, but not rpl22l1 (opposite to colon). In fat, there was a decrease in eIF4E relative to actin (opposite to colon) but also an increase in the eIF4E/4E-BP1 ratio likely due to reductions in 4E-BP1 at our lower eRapa dose (similar to colon). Thus, in contrast to predictions of decreased protein production seen in cell-based studies, we provide evidence that colon from chronically treated mice exhibited an adaptive ‘pseudo-anabolic’ state, which is only partially present in fat, which might relate to differing tissue levels of rapamycin, cell-type-specific responses, and/or strain differences.

Blood levels do not predict behavioral or physiological effects of Δ⁹-tetrahydrocannabinol in rhesus monkeys with different patterns of exposure

BACKGROUND

Recent changes in the legality of cannabis have prompted evaluation of whether blood levels of Δ(9)-tetrahydrocannabinol (THC) or its metabolites could be used to substantiate impairment, particularly related to behavioral tasks such as driving. However, because marked tolerance develops to behavioral effects of THC, the applicability of a particular threshold of blood THC as an index of impairment in people with different patterns of use remains unclear. Studies relevant to this issue are difficult to accomplish in humans, as prior drug exposure is difficult to control.

METHODS

Here, effects of THC to decrease rectal temperature and operant response rate compared to levels of THC and its metabolites were studied in blood in two groups of monkeys: one received intermittent treatment with THC (0.1 mg/kg i.v. every 3-4 days) and another received chronic THC (1 mg/kg/12 h s.c.) for several years.

RESULTS

In monkeys with intermittent THC exposure, a single dose of THC (3.2 mg/kg s.c.) decreased rectal temperature and response rate. The same dose did not affect response rate or rectal temperature in chronically exposed monkeys, indicative of greater tolerance. In both groups, blood levels of THC peaked 20-60 min post-injection and had a similar half-life of elimination, indicating no tolerance to the pharmacokinetics of THC. Notably, in both groups, the behavioral effects of THC were not apparent when blood levels were maximal (20-min post-administration).

CONCLUSION

These data indicate that thresholds for blood levels of THC do not provide a consistent index of behavioral impairment across individuals with different patterns of THC exposure.

Combined treatment of rapamycin and dietary restriction has a larger effect on the transcriptome and metabolome of liver

Rapamycin (Rapa) and dietary restriction (DR) have consistently been shown to increase lifespan. To investigate whether Rapa and DR affect similar pathways in mice, we compared the effects of feeding mice ad libitum (AL), Rapa, DR, or a combination of Rapa and DR (Rapa + DR) on the transcriptome and metabolome of the liver. The principal component analysis shows that Rapa and DR are distinct groups. Over 2500 genes are significantly changed with either Rapa or DR when compared with mice fed AL; more than 80% are unique to DR or Rapa. A similar observation was made when genes were grouped into pathways; two-thirds of the pathways were uniquely changed by DR or Rapa. The metabolome shows an even greater difference between Rapa and DR; no metabolites in Rapa-treated mice were changed significantly from AL mice, whereas 173 metabolites were changed in the DR mice. Interestingly, the number of genes significantly changed by Rapa + DR when compared with AL is twice as large as the number of genes significantly altered by either DR or Rapa alone. In summary, the global effects of DR or Rapa on the liver are quite different and a combination of Rapa and DR results in alterations in a large number of genes and metabolites that are not significantly changed by either manipulation alone, suggesting that a combination of DR and Rapa would be more effective in extending longevity than either treatment alone.

Mice fed rapamycin have an increase in lifespan associated with major changes in the liver transcriptome

Rapamycin was found to increase (11% to 16%) the lifespan of male and female C57BL/6J mice most likely by reducing the increase in the hazard for mortality (i.e., the rate of aging) term in the Gompertz mortality analysis. To identify the pathways that could be responsible for rapamycin's longevity effect, we analyzed the transcriptome of liver from 25-month-old male and female mice fed rapamycin starting at 4 months of age. Few changes (<300 transcripts) were observed in transcriptome of rapamycin-fed males; however, a large number of transcripts (>4,500) changed significantly in females. Using multidimensional scaling and heatmap analyses, the male mice fed rapamycin were found to segregate into two groups: one group that is almost identical to control males (Rapa-1) and a second group (Rapa-2) that shows a change in gene expression (>4,000 transcripts) with more than 60% of the genes shared with female mice fed Rapa. Using ingenuity pathway analysis, 13 pathways were significantly altered in both Rapa-2 males and rapamycin-fed females with mitochondrial function as the most significantly changed pathway. Our findings show that rapamycin has a major effect on the transcriptome and point to several pathways that would likely impact the longevity.

eRapa restores a normal life span in a FAP mouse model

Mutation of a single copy of the adenomatous polyposis coli (APC) gene results in familial adenomatous polyposis (FAP), which confers an extremely high risk for colon cancer. Apc(Min/+) mice exhibit multiple intestinal neoplasia (MIN) that causes anemia and death from bleeding by 6 months. Mechanistic target of rapamycin complex 1 (mTORC1) inhibitors were shown to improve Apc(Min/+) mouse survival when administered by oral gavage or added directly to the chow, but these mice still died from neoplasia well short of a natural life span. The National Institute of Aging Intervention Testing Program showed that enterically targeted rapamycin (eRapa) extended life span for wild-type genetically heterogeneous mice in part by inhibiting age-associated cancer. We hypothesized that eRapa would be effective in preventing neoplasia and extend survival of Apc(Min/+) mice. We show that eRapa improved survival of Apc(Min/+) mice in a dose-dependent manner. Remarkably, and in contrast to previous reports, most of the Apc(Min/+) mice fed 42 parts per million eRapa lived beyond the median life span reported for wild-type syngeneic mice. Furthermore, chronic eRapa did not cause detrimental immune effects in mouse models of cancer, infection, or autoimmunity, thus assuaging concerns that chronic rapamycin treatment suppresses immunity. Our studies suggest that a novel formulation (enteric targeting) of a well-known and widely used drug (rapamycin) can dramatically improve its efficacy in targeted settings. eRapa or other mTORC1 inhibitors could serve as effective cancer preventatives for people with FAP without suppressing the immune system, thus reducing the dependency on surgery as standard therapy.

Chronic rapamycin restores brain vascular integrity and function through NO synthase activation and improves memory in symptomatic mice modeling Alzheimer's disease

Vascular pathology is a major feature of Alzheimer's disease (AD) and other dementias. We recently showed that chronic administration of the target-of-rapamycin (TOR) inhibitor rapamycin, which extends lifespan and delays aging, halts the progression of AD-like disease in transgenic human (h)APP mice modeling AD when administered before disease onset. Here we demonstrate that chronic reduction of TOR activity by rapamycin treatment started after disease onset restored cerebral blood flow (CBF) and brain vascular density, reduced cerebral amyloid angiopathy and microhemorrhages, decreased amyloid burden, and improved cognitive function in symptomatic hAPP (AD) mice. Like acetylcholine (ACh), a potent vasodilator, acute rapamycin treatment induced the phosphorylation of endothelial nitric oxide (NO) synthase (eNOS) and NO release in brain endothelium. Administration of the NOS inhibitor L-NG-Nitroarginine methyl ester reversed vasodilation as well as the protective effects of rapamycin on CBF and vasculature integrity, indicating that rapamycin preserves vascular density and CBF in AD mouse brains through NOS activation. Taken together, our data suggest that chronic reduction of TOR activity by rapamycin blocked the progression of AD-like cognitive and histopathological deficits by preserving brain vascular integrity and function. Drugs that inhibit the TOR pathway may have promise as a therapy for AD and possibly for vascular dementias.

Rapamycin extends life and health in C57BL/6 mice

Target of rapamycin inhibition by rapamycin feeding has previously been shown to extend life in genetically heterogeneous mice. To examine whether it similarly affected mouse health, we fed encapsulated rapamycin or a control diet to C57BL/6Nia mice of both sexes starting at 19 months of age. We performed a range of health assessments 6 and 12 months later. Rapamycin feeding significantly reduced mTOR activity in most but not all tissues. It also reduced total and resting metabolic rate during the light (inactive) phase of the light:dark cycle in females only but had no effect on spontaneous activity or metabolism during the dark (active) phase of either sex. Males only had less fragmented sleep when fed rapamycin, whereas stride length and rotarod performance were improved in both sexes. Survival was also improved by this late-life rapamycin feeding, and some pathological lesions were delayed. We found no adverse health consequences associated with rapamycin treatment.

Evaluation of resveratrol, green tea extract, curcumin, oxaloacetic acid, and medium-chain triglyceride oil on life span of genetically heterogeneous mice

The National Institute on Aging Interventions Testing Program (ITP) was established to evaluate agents that are hypothesized to increase life span and/or health span in genetically heterogeneous mice. Each compound is tested in parallel at three test sites. It is the goal of the ITP to publish all results, negative or positive. We report here on the results of lifelong treatment of mice, beginning at 4 months of age, with each of five agents, that is, green tea extract (GTE), curcumin, oxaloacetic acid, medium-chain triglyceride oil, and resveratrol, on the life span of genetically heterogeneous mice. Each agent was administered beginning at 4 months of age. None of these five agents had a statistically significant effect on life span of male or female mice, by log-rank test, at the concentrations tested, although a secondary analysis suggested that GTE might diminish the risk of midlife deaths in females only.

Long-term oral delivery of encapsulated rapamycin is not detrimental to immunity in old mice (178.11)

Recently, encapsulated rapamycin (e-rapa) was shown to extend lifespan in mice when given at an old age (Harrison Nature 2009), so it has been suggested that this mTOR inhibitor may be efficacious in slowing the aging process. However, use of rapa in the elderly might further compromise immune competence. Therefore, we sought to test the effects of e-rapa on immunity in older individuals by looking at T cell and B cell responses. Because rapa has been shown to be protective against some bacteria and viruses, effects on humoral immunity to a viable microbe were tested. Adult (4 months) and old (20 months) mice on e-rapa or control diets were challenged with the periodontal bacteria Aggregatibacter actinomycetemcomitans; e-rapa did not negatively impact the antibody titers seen in either age group. E-rapa effects on responses to a protein antigen, TAChRα, were also tested. No significant e-rapa effect was seen on antibody titers following primary or boost immunizations. Moreover, pilot data show that T cell proliferation to p146-162, the immunodominant epitope of TAChRα, was not significantly affected by the encapsulated drug. Since TAChR is the autoantigen in Myasthenia Gravis, we also immunized TAChRα transgenic mice (JI 169:6570) and showed that tolerance was maintained and the levels of TREGS were unaffected by e-rapa treatment. To-date, our data suggest that encapsulated rapamycin will not negatively impact immune regulation in old individuals.

Neuroticism, acculturation and the cortisol awakening response in Mexican American adults

Neuroticism is associated with greater susceptibility to the adverse effects of stress and greater exposure to the stressors associated with acculturation in U.S. born Mexican Americans. Neuroticism and acculturation have been associated with injury to crucial stress response systems and are known risk factors for certain mood and anxiety disorders. The purpose of the current study was to examine the effects of neuroticism, and acculturation on the cortisol awakening response (CAR) in healthy Mexican-American adults. Salivary cortisol samples were collected at awakening and 30, 45, and 60 min thereafter, on two consecutive weekdays from 59 healthy Mexican American adult males (26) and females (33), ages 18 to 38 years. Participants were assessed for level of neuroticism and acculturation. Data were analyzed using a mixed effects regression model with repeated measures at four time points. Results showed a significant Neuroticism×Acculturation×Time interaction. The CAR was virtually eliminated in highly acculturated Mexican Americans with greater Anglo orientation and high neuroticism compared with less acculturated Mexican Americans with greater Mexican orientation and lower neuroticism. Findings suggest that some Mexican Americans with high levels of neuroticism may be particularly susceptible to certain challenges and stressors associated with acculturation leading over time to the development of allostatic load, desensitization of the Hypothalamic CRF system and attenuation of the CAR.

The cortisol awakening response predicts subclinical depressive symptomatology in Mexican American adults

While childhood trauma appears to be a risk factor for the onset of depression and subclinical depressive symptomatology in Mexican Americans, the specific physiological mechanisms contributing to this relationship remain to be clarified. Stress-induced dysregulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis is associated with depressive symptomatology in non-Hispanics. The current study assessed the extent to which the cortisol awakening response (CAR) predicts subclinical depressive symptomatology beyond the influence of childhood trauma in a sample of 55 Mexican American males and females ages 18-38 years, without a diagnosis of clinical depression. Participants were assessed for exposure to early trauma and current depressive symptomatology. Salivary cortisol samples were collected on two consecutive days at awakening, 30, 45, and 60 min thereafter, and again at 3 p.m., 6 p.m. and 9 p.m. Data were analyzed using general linear models with repeated measures at four morning time points, and again, at three afternoon and evening time points. Results indicated a significant Symptoms×Time interaction for the CAR(p<0.05). The Symptom×Time interaction was not significant for afternoon and evening cortisol concentrations. Moreover, subclinical symptomatology was associated with attenuation of the initial rise in CAR, after controlling for the total frequency of exposure to childhood traumas. Hierarchical analyses show attenuation of the initial rise in the CAR was the best predictor of greater subclinical depressive symptomatology beyond the influence of trauma, and independent of a current diagnosis of major depression in a sample of adult Mexican Americans.

Acculturation, childhood trauma and the cortisol awakening response in Mexican-American adults

Exposure to chronic and traumatic stress has been associated with the dysregulation of crucial stress response systems. Acculturation has been associated with unique forms of chronic psychosocial stress. The purpose of this study was to examine the effects of exposure to early traumatic stress and acculturation on dysregulation of the cortisol awakening response (CAR) in Mexican-American adults. Salivary cortisol samples were collected at awakening and 30, 45, and 60 min thereafter, on two consecutive weekdays from 59 healthy Mexican-American adult males (26) and females (33), ages 18-38 years. Participants were assessed for level of acculturation and exposure to early trauma. Data were analyzed using a mixed effects regression model with repeated measures at four time points. Mixed effects regression results indicated a significant Early Trauma x Time interaction (p=.0029) and a significant Acculturation x Time interaction (p=.0015), after controlling for age and sex. Subsequent analyses of the interaction of Trauma x Acculturation x Time showed that more than minimal exposure to either risk factor was associated with attenuation of the awakening cortisol response (p=.0002). Higher levels of acculturation with greater Anglo-orientation were associated with attenuation of the CAR in Mexican-American adults. Both moderate and higher levels of exposure to early trauma were associated with an attenuated CAR. However, greater exposure to both risk factors was only incrementally worse than exposure to either one.

Estimating driver risk using alcohol biomarkers, interlock blood alcohol concentration tests and psychometric assessments: initial descriptives

AIM

To identify alcohol biomarker and psychometric measures that relate to drivers' blood alcohol concentration (BAC) patterns from ignition interlock devices (IIDs).

DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS

In Alberta, Canada, 534 drivers, convicted of driving under the influence of alcohol (DUI), installed IIDs and agreed to participate in a research study. IID BAC tests are an established proxy for predicting future DUI convictions. Three risk groups were defined by rates of failed BAC tests. Program entry and follow-up blood samples (n = 302, 171) were used to measure phosphatidyl ethanol (PETH), carbohydrate deficient transferrin (%CDT), gamma glutamyltransferase (GGT) and other biomarkers. Program entry urine (n = 130) was analyzed for ethyl glucuronide (ETG) and ethyl sulphate (ETS). Entry hair samples were tested for fatty acid ethyl esters (FAEE) (n = 92) and ETG (n = 146). Psychometric measures included the DSM-4 Diagnostic Interview Schedule Alcohol Module, Alcohol Use Disorders Identification Test (AUDIT), the time-line follow-back (TLFB), the Drinker Inventory of Consequences (DRINC) and the Temptation and Restraint Inventory (TRI).

FINDINGS

Except for FAEE, all alcohol biomarkers were related significantly to the interlock BAC test profiles; higher marker levels predicted higher rates of interlock BAC test failures. PETH, the strongest with an overall analysis of variance F ratio of 35.5, had significant correlations with all nine of the other alcohol biomarkers and with 16 of 19 psychometric variables. Urine ETG and ETS were correlated strongly with the IID BAC tests.

CONCLUSIONS

The findings suggest that several alcohol biomarkers and assessments could play an important role in the prediction and control of driver alcohol risk when re-licensing.

Design of aging intervention studies: the NIA interventions testing program

The field of biogerontology has made great strides towards understanding the biological processes underlying aging, and the time is ripe to look towards applying this knowledge to the pursuit of aging interventions. Identification of safe, inexpensive, and non-invasive interventions that slow the aging process and promote healthy aging could have a significant impact on quality of life and health care expenditures for the aged. While there is a plethora of supplements and interventions on the market that purport to slow aging, the evidence to validate such claims is generally lacking. Here we describe the development of an aging interventions testing program funded by the National Institute on Aging (NIA) to test candidate interventions in a model system. The development of this program highlights the challenges of long-term intervention studies and provides approaches to cope with the stringent requirements of a multi-site testing program.

Acute tolerance to rate-decreasing effects of single doses of ethanol

Acute tolerance occurs when behavioral impairment is greater at a given blood ethanol concentration (BAC) on the ascending versus descending limb of the BAC-time curve following administration of a single dose of ethanol, however studies utilizing learned behaviors have not been widely reported. We assessed acute tolerance to single doses of ethanol in five Lewis rats responding under a fixed-ratio (FR8) schedule of food presentation. Response rates for food during 1-min components (ending 2, 4, 11, 18, 33, and 57 min after ethanol administration) were determined, and BAC was measured immediately after each component using a rat breathalyzer. Ethanol (0.4, 0.6, 0.8, and 1.2 g/kg, i.p.) produced dose-related decreases in responding for food that tended to recover over time for all but the highest dose tested. Similarly, dose-related increases in BAC were also observed. Using either an analysis that expressed impairment per unit BAC on the ascending limb versus the descending limb (by assessing the area under the curve (AUC) for behavior and BAC on each limb), the slope of the function that relates the behavioral effect to BAC (each expressed as percent maximum effect), or a variant of the Mellanby method (hysteresis), acute tolerance was observed following a dose of 0.4 g/kg ethanol. Though behavior appeared to recover on the descending limb following higher doses (especially 0.6 and 0.8 g/kg), acute tolerance to these doses was not present.

The effect of the ingestion of Ginkgo biloba extract (EGb 761) on the pharmacokinetics of metformin in non-diabetic and type 2 diabetic subjects--a double blind placebo-controlled, crossover study

BACKGROUND & AIMS

Ginkgo biloba extract (EGb 761) has been shown to ameliorate some defects associated with the insulin resistance syndrome and so patients with Type 2 diabetes mellitus (T2DM) may be inclined to co-ingest the herb with their medications, such as metformin. This study was designed to determine if the co-ingestion of EGb 761 and metformin would alter the pharmacokinetic properties of metformin in T2DM patients and persons without diabetes, who may ingest it for other purposes.

METHOD

Normal glucose tolerance (NGT) subjects (n=10; age, 39.2+/-14.0 years; fasting plasma glucose (FPG), 90+/-7 mg/dl; body mass index (BMI), 24.1+/-3.7 kg/m(2)) and 10 T2DM patients (n=10; age, 51.7+/-8.9 years; FPG, 150+/-7 mg/dl; BMI, 33.7+/-5.7 kg/m(2)) completed a randomized, double-blind, placebo-controlled crossover study. They ingested either EGb 761 (12 0mg/day as a single dose) or a vegetable-based placebo during each arm for 3 months. At the end of each arm, the NGT subject ingested a single 500 mg dose of metformin (non-diabetics) and the T2DM subject took his/her prescribed metformin dose (250-850 mg) with 120 mg EGb 761. Blood and urine samples were collected over an 8-h period, and in the case of T2DM subjects, additionally over the first 2h of the subsequent 3 days.

RESULTS

Ingestion of EGb 761 produced no significant changes in diagnostic laboratory tests in either group, except reducing glycosylated hemoglobin A(1c) levels (from 7.7+/-1.2 to 7.2+/-0.9%, P<0.05) in T2DM the subjects. The pharmacokinetic parameters of metformin were all significantly different (P<0.05) between the NGT (500 mg) and 8 out of 10 of the T2DM subjects who were prescribed 500 mg of metformin during the placebo cycles. During the EGb 761 cycles, only the elimination half-life in the T2DM subjects was significantly increased (0.117+/-0.085 to 0.141+/-0.100, P<0.05).

CONCLUSION

The co-ingestion of 120 mg of EGb 761 and 500 mg of metformin did not significantly affect the pharmacokinetic properties of metformin. Further studies are required to verify this observation for smaller and larger dose of metformin with other doses of EGb 761, since T2DM patients on medication constitute a very heterogeneous group.

Emerging Biomarkers: New Directions and Clinical Applications

This article summarizes content proceedings of a symposium held at the 2004 Research Society on Alcoholism Scientific Annual Meeting in Vancouver, Canada. The chairs were Friedrich M. Wurst and Raye Litten. The presentations were (1) Introduction, by Raye Litten; (2) Direct Ethanol Metabolites--On the Threshold From Science to Routine Use, by Friedrich M. Wurst; (3) Sialic Acid Index of Plasma Apolipoprotein J (SIJ) as a Viable Marker for Chronic Alcohol Consumption, by Philippe Marmillot; (4) The Emergence of Ethyl Glucuronide (EtG) Testing as a Tool in Monitoring Healthcare Professionals, by Gregory E. Skipper; (5) Application of Biomarkers for Alcohol Use Disorders in Clinical Practice, by Tim Neumann; (6) Utility of Biomarkers in Assessing the Efficacy of Medications for Treating Alcoholism, by Marty Javors; and (7) Discussion, by Raye Litten.

Effect of valproic acid on serotonin-2A receptor signaling in C6 glioma cells

Valproic acid (VPA), which has demonstrated efficacy in the treatment of bipolar disorder, has been shown to alter components of the phosphoinositide (PI) signaling cascade and to increase gene expression mediated by the transcription factor activator protein 1 (AP-1). Central serotonin-2A (5-HT2A) receptors, which have been implicated in the pathophysiology of manic-depressive illness, are coupled to PI hydrolysis. The promoter region of the 5-HT2A receptor gene contains AP-1 binding sites. We examined in C6 glioma cells the effect of VPA on 5-HT2A receptor signaling. Treatment of cells with VPA (100 microg/mL) for 20 h, but not 1.5 h, resulted in an enhancement of 5-HT2A receptor-stimulated PI hydrolysis. This effect of 20-h VPA exposure appeared not to be at the level of G protein or effector (i.e. phospholipase C: PLC) as inositol phosphate accumulation stimulated by aluminum fluoride or the PLC activator 2,4,6-trimethyl-N-(m-3-trifluromethylphenyl) benzenesulfonamide was not increased. The number of 5-HT2A receptors, as determined in saturation binding experiments using [3H]ketanserin, was increased by 20-h VPA treatment, with no change in affinity (KD). Taken together, our data suggest that the increase in 5-HT2A receptor-mediated PI hydrolysis following 20-h VPA exposure is not due to a general effect of VPA on this signaling cascade, but due to the up-regulation of 5-HT2A receptor number.

Modulatory effects of norepinephrine in the lateral bed nucleus of the stria terminalis on behavioral and neuroendocrine responses to acute stress

The brain noradrenergic system is activated by stress, and modulates the activity of forebrain regions involved in behavioral and neuroendocrine responses to stress, such as the lateral bed nucleus of the stria terminalis (BSTL). This region of the limbic forebrain receives dense noradrenergic innervation, and has been implicated in both anxiety and regulation of the hypothalamic-pituitary-adrenal axis. We hypothesized that stress-induced release of norepinephrine in the BSTL modulates anxiety-like behavioral responses to stress and activation of the hypothalamic-pituitary-adrenal stress axis. Using microdialysis, we showed that release of norepinephrine was increased in the BSTL of male Sprague-Dawley rats during immobilization stress. In the next experiment, we then microinjected noradrenergic antagonists into the BSTL immediately prior to acute immobilization stress to examine noradrenergic modulation of behavioral stress reactivity. Either the alpha(1)-receptor antagonist benoxathian, or a cocktail of beta(1)- and beta(2)-receptor antagonists (betaxolol+ICI 118,551) blocked the anxiety-like reduction in open-arm exploration on the elevated plus-maze, but not the reduction in social behavior induced in the social interaction test. In a third experiment, benoxathian reduced plasma levels of adrenocorticotropic hormone following stress, but beta-receptor antagonists had no effect. From these results we suggest that stress-induced norepinephrine release acts on both alpha(1)- and beta-receptors in the BSTL to facilitate anxiety-like behavioral responses on the plus-maze but not the social interaction test, and modulates hypothalamic-pituitary-adrenal axis activation via alpha(1)-receptors only. Together with previous results in which adrenergic antagonists in central amygdala attenuated behavioral responses on the social interaction test but not the plus-maze, these observations suggest the two behavioral tests measure different dimensions of stress reactivity, and that norepinephrine facilitates different components of the stress response by region- and receptor-specific mechanisms.

Behavioral reactivity to stress: amplification of stress-induced noradrenergic activation elicits a galanin-mediated anxiolytic effect in central amygdala

Brain norepinephrine (NE) modulates many aspects of the stress response. The interaction between NE and neuropeptides such as galanin, with which it is closely associated and which may be released from noradrenergic terminals under conditions of high activity, has not been well studied. We therefore investigated the modulatory effects of galanin in the central nucleus of the amygdala (CeA) on behavioral responsivity to stress when activation of the noradrenergic system was amplified using the adrenergic autoreceptor antagonist yohimbine (2.5 mg/kg ip). Either immobilization stress or yohimbine alone had anxiogenic effects on rat behavior in the elevated plus maze. However, yohimbine pretreatment before stress produced a paradoxical anxiolytic response, which we hypothesized was attributable to galanin release in CeA. Microdialysis verified that yohimbine amplified NE release in CeA during immobilization stress, and also showed that whereas there was no detectable change in galanin release in CeA during stress alone, there was an increase during immobilization stress after yohimbine pretreatment. Bilateral administration of the galanin antagonist M40 into CeA before stress blocked the anxiolytic influence of yohimbine pretreatment. Exogenous galanin mimicked the anxiolytic effect of yohimbine pretreatment, and this too was blocked by M40. These results suggest that amplifying the noradrenergic response to stress can recruit galanin release in CeA, which buffers the anxiety-like behavioral response to acute stress. The balance between noradrenergic and peptidergic neurotransmission may be modified by prior stress, drug treatment or genetic variability, and may represent a novel target for treatment of stress-related neuropsychiatric disorders.

Combining ondansetron and naltrexone treats biological alcoholics: corroboration of self-reported drinking by serum carbohydrate deficient transferrin, a biomarker

BACKGROUND

Recently, we showed by using self-report that combining ondansetron (4 microg/kg twice a day) and naltrexone (25 mg twice a day) was effective at reducing drinking and increasing abstinence among early-onset alcoholics (EOAs), who are characterized by a range of antisocial behaviors and high biological and familial disease predisposition. Here, we investigated whether the self-reported differences in drinking would be corroborated by measurements of serum carbohydrate-deficient transferrin (CDT) level, a sensitive, reliable, and well-validated marker of transient alcohol consumption.

METHOD

An 8-week double-blind clinical trial was performed in which 20 EOAs were randomized to receive ondansetron (4 microg/kg twice a day) and naltrexone (25 mg twice a day) or placebo as an adjunct to weekly standardized cognitive behavioral therapy. Serum CDT was assessed at weeks 0 (baseline), 4, and 8.

RESULTS

Log serum CDT was significantly lower in the ondansetron and naltrexone group (group mean, 1.44 +/- 0.076) compared with the placebo group (group mean, 1.82 +/- 0.113), as evidenced by a main effect of group [F(1,15) = 7.2, p = 0.017; effect size = 0.32], visit [F(1,16) = 11.2, p = 0.004; effect size = 0.41], and an interaction between group and visit [F(1,16) = 27.54, p < 0.001; effect size = 0.63].

CONCLUSIONS

The combination of ondansetron plus naltrexone was superior to placebo at reducing serum CDT. This corroborated our self-reported drinking data and demonstrated that the medication combination is an effective treatment for EOAs.

Innovative technologies for the diagnosis of alcohol abuse and monitoring abstinence

This article summarizes the proceedings of a workshop presented at the 2000 RSA Meeting in Denver, Colorado. The aim of this workshop was to discuss the basic methodologies, diagnostic performance, and clinical utility of three technologies: carbohydrate-deficient transferrin, the "Early Detection of Alcohol Consumption" score, and whole blood associated acetaldehyde. Each method adopts a different strategy to identify heavy alcohol consumption and offers a unique approach to determine alcohol abstinence and relapses. Appropriate application of these technologies can lead to early intervention for alcohol problems before significant tissue damage occurs. To date these methodologies have yet to be formally contrasted and compared. Sensitivity, specificity, predictive value, availability, ease of use, and interpretation of tests results are important aspects to consider when selecting the most appropriate and cost-effective system. Critical evaluation of these methodologies can enable research and clinical laboratories to choose the system that best meets their particular needs in terms of assay feasibility, budget, and goals.

Platelet serotonin uptake is higher in early-onset than in late-onset alcoholics

The main objective of this study was to compare platelet serotonin (5-HT) uptake between early-onset alcoholics (EOA) and late-onset alcoholics (LOA). Subjects were 24 dependent male alcoholic in-patients and 21 healthy control subjects. 5-HT uptake was quantified by incubating platelets with [3H]5-HT at various concentrations (0.5 to 1000 nM). 5-HT uptake was higher in EOA, compared to both the LOA and control groups (P < 0.02) at the highest 5-HT concentration (1000 nM). No significant difference was found between LOA and controls or between EOA + LOA and controls. Previous studies have shown that 5-HT uptake was higher in platelets, lymphocytes, and brain of alcoholics vs controls, but our data suggest that higher platelet serotonin transporter function is limited to EOA, not LOA.

Increased norepinephrine levels during catheterization in patients with spinal cord injury

The hypothesis for this study was that catecholamine levels increase during urinary catheterization in human patients with spinal cord injury. Catecholamine levels, blood pressure, and pulse were measured prospectively in 40 subjects at baseline and during urinary catheterization. Results showed a significant increase in norepinephrine levels from baseline 245 +/- 240 pg (standard deviation (SD)) to 314 +/- 311 pg (SD) during catheterization (P = 0.018, Wilcoxon's). Results also showed a nonsignificant increase in epinephrine levels from baseline (56 +/- 70 pg, SD) to catheterization (84 +/- 125 pg, SD; P = 0.35, Wilcoxon's). Systolic blood pressure increased from 114 to 124 mm Hg (P = 0.004, paired t test). Diastolic blood pressure increased from 75 to 78 mm Hg (P = 0.11, paired t test). There was no significant change in diastolic blood pressure or pulse (P = 0.11 and P = 0.29, respectively, paired t test). In conclusion, norepinephrine levels increased during catheterization in patients with spinal cord injury. Knowledge of catecholamine levels in this process may assist in determining both pathophysiology and potential pharmacologic treatment options in future studies.

Incorporation of [3H]valproic acid into lipids in GT1-7 neurons

Valproic acid (2-propylpentanoic acid, valproate, VPA), an 8-carbon, branched chain fatty acid, is effectively used in the treatment of mania and epilepsy. The biochemical mechanisms by which this drug has its therapeutic effects are not yet established. The purpose of this study was to partially characterize the incorporation of [3H]VPA into phospholipids of GT1-7 neurons, an immortalized hypothalamic cell line. GT1-7 neurons were grown to confluence in culture dishes, and then were incubated with various concentrations of [3H]VPA between 10 and 400 microg/mL for various times up to 20 hr. Total lipids were extracted and phospholipids were separated from neutral lipids using TLC. Our results indicate that [3H]VPA (10 microg/mL) was incorporated into phospholipids of GT1-7 neurons in a time-dependent and saturable manner over 300 min. Subsequent separation of the lipid fraction by TLC indicated that 44.4% of the radioactivity taken up by the cells was incorporated into phospholipids and neutral lipids. One of the phospholipids migrated with a slightly lower Rf value than authentic phosphatidylcholine. Our results show that the incorporation of VPA into phospholipids and glycerides was linear with VPA concentrations from 10 to 400 microg/mL. Finally, we synthesized 1-acyl-2-valproyl-sn-glycero-3-phosphocholine and validated its structure with nuclear magnetic resonance and electrospray mass spectrometry to verify the structure of this compound, confirming that this compound is structurally possible. We conclude that VPA is incorporated into lipids in GT1-7 neurons and discuss the possible effects of valproyl phospholipids on neuronal functional properties.

Platelet reactivity with liposome-encapsulated hemoglobin in the rat

Infusion of liposome-encapsulated hemoglobin (LEH) induces a transient thrombocytopenia in rats (Rabinovici R, Rudolph AS, Ligler FS, Smith EF, III, Feuerstein G [1992] Biological responses to exchange transfusion with liposome-encapsulated hemoglobin. Circ Shock 37:124). A specific mechanism such as a localization of platelets during this transient LEH-induced thrombocytopenia has not been reported previously in the literature. In this study, platelets were isolated and labeled with indium-111 (111In), then retransfused into the same animal. Fifteen minutes after the 111In platelets were retransfused and allowed to equilibrate with the blood pool, a 10% top load volume of either LEH (1.8 mL, 262 mg phospholipid/kg body weight, 92 mg hemoglobin (Hb)/kg body weight), liposome vehicle (LV) (1.8 mL, 262 mg phospholipid/kg body weight), or free bovine Hb (1.8 mL, 92 mg Hb/kg body weight) (n=6 per group) was infused. Serial blood samples were drawn to determine platelet counts by radioactivity and light scattering methods. LV and Hb demonstrated no significant changes from baseline levels in circulating platelet levels, whereas LEH caused a transient 50% decrease in 111In platelet activity 2-5 minutes postinfusion, which returned to baseline levels by 15 minutes. Platelet counts based on traditional light scattering methods were not significantly different among the three treatment groups over this same time course. Localization of these 111In platelets was monitored with a gamma scintigraphic camera. After infusion of LEH, 111In platelets rapidly moved out of the circulation and sequestered in the lungs and liver with subsequent return to the circulation by 15 minutes. In contrast, no significant changes in 111In platelet activity were noted in the lungs and liver after infusion of LV and Hb. 111In platelet activity in the spleen nearly doubled 30 minutes after Hb infusion and was significantly different than spleen 111In platelet activity in the LEH and LV groups. In vitro platelet aggregation studies were also performed to determine the direct effect of LEH, LV, and Hb on platelet aggregation. The rate of thrombin-induced aggregation did not differ among control samples and samples containing LEH, LV, or Hb; none of these agents induced platelet aggregation. We conclude that LEH-induced thrombocytopenia is associated with a transient (within minutes) sequestration of platelets in the lungs and liver, with subsequent release to the circulation within 15 minutes. Tetrameric bovine Hb is associated with increased platelet accumulation in the spleen. Light scattering methods for measuring platelet levels in blood samples containing LEH are unreliable because of particulate interference.

Cerebrospinal fluid biogenic amine metabolites in fibromyalgia/fibrositis syndrome and rheumatoid arthritis

OBJECTIVE

To compare the levels of biogenic amines in the cerebrospinal fluid (CSF) of primary fibromyalgia syndrome (PFS) patients with those in the CSF of controls.

METHODS

Metabolites of serotonin, norepinephrine, and dopamine were identified in CSF, using high performance liquid chromatography with coulometric detection.

RESULTS

CSF levels of metabolites from all 3 neurotransmitters were lower in PFS patients than in controls.

CONCLUSION

A low rate of turnover of several neurotransmitters supports the proposed hypothesis of a metabolic defect in PFS and suggests that the defect occurs at a neuroregulatory level.