Production of immunogenic West Nile virus-like particles using a herpes simplex virus 1 recombinant vector

West Nile virus (WNV) is a flavivirus that swept rapidly across North America in 1999, declined in prevalence, and then resurged in 2012. To date, no vaccine is available to prevent infection in the human population. Herpes simplex virus (HSV) replication-defective vaccine vectors induce a durable immunity characterized by strong antibody and CD8(+) T cell responses even in HSV-immune animals. In this study, a WNV protein expression cassette was optimized for virus-like particle (VLP) production in transfection studies, and the cassette was recombined into an HSV-1 d106-WNV virus vector, which produced extracellular VLPs, as confirmed by immunoelectron microscopy. Immunization of mice with the d106-WNV recombinant vector elicited a specific anti-WNV IgG response. This study highlights the flavivirus coding sequences needed for efficient assembly of virus-like particles. This information will facilitate generation of additional vaccine vectors against other flaviviruses including the recently emerged Zika virus.

The carbon footprint of acute care: how energy intensive is critical care?

OBJECTIVES

Climate change has the potential to threaten human health and the environment. Managers in healthcare systems face significant challenges to balance carbon mitigation targets with operational decisions about patient care. Critical care units are major users of energy and hence more evidence is needed on their carbon footprint.

STUDY DESIGN

The authors explore a methodology which estimates electricity use and associated carbon emissions within a Critical Care Unit (CCU).

METHODS

A bottom-up model was developed and calibrated which predicted the electricity consumed and carbon emissions within a CCU based on the type of patients treated and working practices in a case study in Cornwall, UK.

RESULTS

The model developed was able to predict the electricity consumed within CCU with an error of 1% when measured against actual meter readings. Just under half the electricity within CCU was used for delivering care to patients and monitoring their condition.

CONCLUSIONS

A model was developed which accurately predicted the electricity consumed within a CCU based on patient types, medical devices used and working practice. The model could be adapted to enable it to be used within hospitals as part of their planning to meet carbon reduction targets.

Medical conditions and symptoms associated with posttraumatic stress disorder in low-income urban women

BACKGROUND

Epidemiological studies have consistently reported rates of posttraumatic stress disorder (PTSD) in women that are twice that of men. In men and women, PTSD has been associated with comorbid medical conditions, medical symptoms and lower self-rating of health. In low-income urban women, rates of PTSD are even more elevated than in suburban women and may be related to observed health disparities.

METHODS

In this study, 250 women seeking healthcare at an urban clinic were interviewed for a PTSD diagnosis, major depressive disorder (MDD), the experience of traumatic events, the experience of current and past common medical conditions and symptoms, and subjective rating of health. A chart review was used to assess healthcare use in the past year.

RESULTS

More current (5.2 vs. 3.8, p < 0.05) and past medical conditions (4.6 vs. 3.3, p < 0.05) were reported by women with a lifetime history of PTSD than by women without this history, after controlling for demographics and current depression. Women with lifetime PTSD also had more annual clinic appointments (5.9 vs. 3.8 p < 0.03) and were 2.4 times (p < 0.05) more likely to report lower appraisal of their physical health.

CONCLUSIONS

These findings suggest that urban health-seeking women with PTSD experience health impairments that may cause increased morbidity and that healthcare providers should consider the health ramifications of PTSD when providing medical care to women.

The use of green fluorescent fusion proteins to monitor herpes simplex virus replication

The localization pattern of the seven herpes simplex virus (HSV) DNA replication proteins is dependent upon the status of viral DNA synthesis in the infected cell. Normally, the replication proteins accumulate within replication compartments, which expand as viral DNA synthesis increases. If viral replication is blocked, either by the addition of drugs or a genetic lesion, prereplicative sites are observed. Observing the distribution of a GFP-tagged HSV replication protein can monitor the progression of viral replication. Here, we demonstrate the use of an ICP8-GFP fusion protein to observe the status of HSV replication in cultured cells by the formation of viral replication compartments.

Disposition of CP-671, 305, a selective phosphodiesterase 4 inhibitor in preclinical species

1. The disposition of (+)-2-[4-({[2-(benzo[1,3] dioxol-5-yloxy)-pyridine-3-carbonyl]-amino)-methyl)-3-fluoro-phenoxyl-propionic acid (CP-671,305), a potent and selective inhibitor of phosphodiesterase 4 (subtype D), was characterized in several animal species in support of its selection for preclinical safety studies and potential clinical development. 2. CP-671,305 demonstrates generally favourable pharmacokinetic properties in all species examined. Systemic plasma clearance after intravenous administration was low in Sprague-Dawley rats (9.60+/-1.16 ml min(-1) kg(-1)), beagle dogs (2.90+/-0.81 ml min(-1) kg(-1)) and cynomolgus monkeys (2.94+/-0.87ml min(-1) kg(-1)) resulting in plasma half-lives > 5 h. Moderate to high bioavailability in rats (43-80%), dogs (45%) and monkeys (26%) was observed after oral dosing. In rats, oral pharmacokinetics were dose dependent over the dose range studied (10 and 25 mgkg(-1)). 3. CP-671,305 was > 97% bound to plasma proteins in rat, dog, monkey and human. 4. The principal route of clearance of CP-671,305 in rats and dogs was by renal and biliary excretion of unchanged drug. This finding was consistent with CP-671,305 resistance towards metabolism in hepatocytes and NADPH-supplemented liver microsomes from preclinical species and human. 5. CP-671,305 did not exhibit competitive inhibition of the five major cytochrome P450 enzymes, namely CYP1A2, 2C9, 2C19, 2D6 and 3A4 (IC50's > 50 microM). Likewise, no time-dependent inactivation of the five major cytochrome P450 enzymes was discernible with CP-671,305. 6. Overall, the results indicate that the absorption, distribution, metabolism and excretion (ADME) profile of CP-671,305 is relatively consistent across preclinical species and predict potentially favourable pharmacokinetic properties in humans, supporting its selection for toxicity/safety assessment studies and possible investigations in humans.

Inhibitors of the sodium potassium ATPase that impair herpes simplex virus replication identified via a chemical screening approach

Small molecules can provide valuable tools to investigate virus biology. We developed a chemical screening approach to identify small molecule inhibitors of poorly understood, pre-early gene expression steps in herpes simplex virus infection, using green fluorescent protein fused to an early protein. Our assay identified ouabain, a cardiac glycoside. Ouabain reversibly decreased viral yield by 100-fold without affecting cellular metabolic activity in an overnight assay. The antiviral potencies of other cardiac glycosides correlated with their potencies against the known target of these compounds, the cellular sodium potassium ATPase. Ouabain had a reduced effect if added 8 h post-infection. It did not inhibit viral attachment or entry, but did reduce the expression of viral immediate-early and early genes by at least 5-fold. Collectively, these results implicate a cellular target that was hitherto not considered important for a stage of HSV replication prior to viral gene expression.

Evidence for a direct interaction between HSV-1 ICP27 and ICP8 proteins

Herpes simplex virus 1 (HSV-1) ICP27 and ICP8 proteins have both been implicated in the transcription of late genes and regulation of viral gene expression. We showed previously that ICP27 and ICP8 associate with the RNAP II holoenzyme (Zhou and Knipe, J. Virol. 76, 5893-5904). Here, we demonstrate that ICP27 and ICP8 coprecipitate from lysates of HSV-1-infected HEp2 cells and from lysates of insect cells expressing ICP27 and ICP8, the latter being in the absence of other HSV-1 proteins. By expressing and purifying hexahistidine-tagged ICP8 (His-ICP8) and maltose binding protein (MBP)-tagged ICP27 (MBP-27) proteins and performing in vitro immunoprecipitation and pull-down assays, we also demonstrate that ICP27 and ICP8 coprecipitate in the absence of other viral or cellular proteins. Taken together, these data provide evidence that ICP27 and ICP8 interact directly in vitro and in infected cells. We hypothesize that the ICP27-ICP8 interaction plays a role in the stimulation of late gene transcription.

Proteomics of herpes simplex virus infected cell protein 27: association with translation initiation factors

The herpes simplex virus (HSV) immediate early ICP27 protein plays an essential role in stimulating viral early and late gene expression. ICP27 appears to be multifunctional in that it has been reported to stimulate viral late gene transcription, polyadenylation site usage, and RNA export. We report here on proteomic studies involving immunoprecipitation of ICP27 and mass spectrometric identification of co-precipitated proteins. These studies show an association of ICP27 with the cellular translation initiation factors poly A binding protein (PABP), eukaryotic initiation factor 3 (eIF3), and eukaryotic initiation factor 4G (eIF4G) in infected cells. Immunoprecipitation-western blot studies confirmed these associations. Finally, purified MBP-tagged ICP27 (MBP-27) can interact with eIF3 subunits p47 and p116 in vitro. These results suggest that ICP27 may also play a role in stimulating translation of certain viral and host mRNAs and/or in inhibiting host mRNA translation.

Proteomics of herpes simplex virus replication compartments: association of cellular DNA replication, repair, recombination, and chromatin remodeling proteins with ICP8

In this study, we have used immunoprecipitation and mass spectrometry to identify over 50 cellular and viral proteins that are associated with the herpes simplex virus 1 (HSV-1) ICP8 single-stranded DNA-binding protein. Many of the coprecipitating cellular proteins are known members of large cellular complexes involved in (i) DNA replication or damage repair, including RPA and MSH6; (ii) nonhomologous and homologous recombination, including the catalytic subunit of the DNA-dependent protein kinase, Ku86, and Rad50; and (iii) chromatin remodeling, including BRG1, BRM, hSNF2H, BAF155, mSin3a, and histone deacetylase 2. It appears that DNA mediates the association of certain proteins with ICP8, while more direct protein-protein interactions mediate the association with other proteins. A number of these proteins accumulate in viral replication compartments in the infected cell nucleus, indicating that these proteins may have a role in viral replication. WRN, which functions in cellular recombination pathways via its helicase and exonuclease activities, is not absolutely required for viral replication, as viral yields are only very slightly, if at all, decreased in WRN-deficient human primary fibroblasts compared to control cells. In Ku70-deficient murine embryonic fibroblasts, viral yields are increased by almost 50-fold, suggesting that the cellular nonhomologous end-joining pathway inhibits HSV replication. We hypothesize that some of the proteins coprecipitating with ICP8 are involved in HSV replication and may give new insight into viral replication mechanisms.

Herpes simplex virus replication compartments can form by coalescence of smaller compartments

Herpes simplex virus (HSV) uses intranuclear compartmentalization to concentrate the viral and cellular factors required for the progression of the viral life cycle. Processes as varied as viral DNA replication, late gene expression, and capsid assembly take place within discrete structures within the nucleus called replication compartments. Replication compartments are hypothesized to mature from a few distinct structures, called prereplicative sites, that form adjacent to cellular nuclear matrix-associated ND10 sites. During productive infection, the HSV single-stranded DNA-binding protein ICP8 localizes to replication compartments. To further the understanding of replication compartment maturation, we have constructed and characterized a recombinant HSV-1 strain that expresses an ICP8 molecule with green fluorescent protein (GFP) fused to its C terminus. In transfected Vero cells that were infected with HSV, the ICP8-GFP protein localized to prereplicative sites in the presence of the viral DNA synthesis inhibitor phosphonoacetic acid (PAA) or to replication compartments in the absence of PAA. A recombinant HSV-1 strain expressing the ICP8-GFP virus replicated in Vero cells, but the yield was increased by 150-fold in an ICP8-complementing cell line. Using the ICP8-GFP protein as a marker for replication compartments, we show here that these structures start as punctate structures early in infection and grow into large, globular structures that eventually fill the nucleus. Large replication compartments were formed by small structures that either moved through the nucleus to merge with adjacent compartments or remained relatively stationary within the nucleus and grew by accretion and fused with neighboring structures.

C-terminal region of herpes simplex virus ICP8 protein needed for intranuclear localization

The herpes simplex virus single-stranded DNA-binding protein, ICP8, localizes initially to structures in the nucleus called prereplicative sites. As replication proceeds, these sites mature into large globular structures called replication compartments. The details of what signals or proteins are involved in the redistribution of viral and cellular proteins within the nucleus between prereplicative sites and replication compartments are poorly understood; however, we showed previously that the dominant-negative d105 ICP8 does not localize to prereplicative sites and prevents the localization of other viral proteins to prereplicative sites (J. Virol. 74 (2000) 10122). Within the residues deleted in d105 (1083 to 1168), we identified a region between amino acid residues 1080 and 1135 that was predicted by computer models to contain two alpha-helices, one with considerable amphipathic nature. We used site-specific and random mutagenesis techniques to identify residues or structures within this region that are required for proper ICP8 localization within the nucleus. Proline substitutions in the predicted helix generated ICP8 molecules that did not localize to prereplicative sites and acted as dominant-negative inhibitors. Other substitutions that altered the charged residues in the predicted alpha-helix to alanine or leucine residues had little or no effect on ICP8 intranuclear localization. The predicted alpha-helix was dispensable for the interaction of ICP8 with the U(L)9 origin-binding protein. We propose that this C-terminal alpha-helix is required for localization of ICP8 to prereplicative sites by binding viral or cellular factors that target or retain ICP8 at specific intranuclear sites.

Herpes simplex virus

Herpes simplex virus (HSV) commonly causes human infections in the orofacial region (HSV-1) and in the genital region (HSV-2). Productive viral infection in mucosal epithelial cells may result in clinical symptoms and is followed by a latent infection within sensory neurons. During productive infection a large number of viral gene products are expressed while during latent infection few or no viral proteins are expressed. Reactivation from latency results in recurrent infections and disease at or near the primary site of infection. Understanding the details of the two stages of the HSV life cycle is a particular focus of current research on HSV. The virus interacts with and modifies numerous host cell functions in both epithelial and neuronal cells, and studies of HSV have enhanced our knowledge of many fundamental processes in eukaryotic cells. Ongoing research continues to uncover novel effects of HSV on cells, and a complete understanding of HSV infection during both productive and latent infection should allow the design of new antiviral agents and vaccines and increased knowledge of basic cell and molecular biology. This review article is designed to provide an introduction to HSV biology and key aspects of the infection cycle.

Naming the color of a word: is it responses or task sets that compete?

Subjects named the colors in which high- and low-frequency words and pronounceable nonwords, otherwise matched, were displayed. Color naming was slower for all three item types than for visually equivalent strings of nonalphanumeric symbols but was no slower for words than for nonwords, nor for high-frequency words than for low-frequency words. Unpronounceable letter strings had intermediate color-naming latencies. However, frequency and lexical status had large effects on latency for reading the same words and pseudowords aloud. Interference is thus predicted not by the strength of association between a letter string and its pronunciation but by the presence of word-like constituents. We argue that the interference from an unprimed noncolor word is due to, and isolates, one of two components of the classic Stroop effect: competition from the whole task set of reading. The other component, response competition, occurs only when lexical access is sufficiently primed.

Biological properties of herpes simplex virus 2 replication-defective mutant strains in a murine nasal infection model

We used a mouse nasal model of herpes simplex virus 2 (HSV-2) infection to examine the biological properties of HSV-2 wild-type (wt), TK-negative, and replication-defective strains in vivo. Nasal septa tissue is the major site of wt viral replication post intranasal (i.n.) inoculation. The HSV-2 strain 186 syn(+)-1 wt virus caused lethal encephalitis at doses of 10(4) PFU and above per nostril, and at lower doses no neurons in the trigeminal ganglia were positive for the latency-associated transcript, indicating a lack of latent infection. The 186DeltaKpn TK-negative mutant virus replicated in nasal septa tissue but showed low-level replication in trigeminal ganglia at only one timepoint. In situ hybridization of trigeminal ganglia showed that the number of LAT-positive neurons was proportional to the inoculum dose from 10(3) to 10(6) PFU per nare. The replication-defective mutant virus 5BlacZ showed no replication in nasal septa tissue and no persistence of viral DNA at the inoculation site or the trigeminal ganglia. Nevertheless, inoculation of 5BlacZ or the double-mutant dl5-29 at distal sites reduced acute replication and latent infection of 186DeltaKpn following intranasal challenge. This infection model provides a biological system to test the properties of HSV-2 strains and shows that replication-defective mutant strains do not persist at sites of inoculation or in sensory ganglia but can induce immune protection that reduces the latent viral load of a challenge virus.

A dominant-negative herpesvirus protein inhibits intranuclear targeting of viral proteins: effects on DNA replication and late gene expression

The d105 dominant-negative mutant form of the herpes simplex virus 1 (HSV-1) single-stranded DNA-binding protein, ICP8 (d105 ICP8), inhibits wild-type viral replication, and it blocks both viral DNA replication and late gene transcription, although to different degrees (M. Gao and D. M. Knipe, J. Virol. 65:2666-2675, 1991; Y. M. Chen and D. M. Knipe, Virology 221:281-290, 1996). We demonstrate here that this protein is also capable of preventing the formation of intranuclear prereplicative sites and replication compartments during HSV infection. We defined three patterns of ICP8 localization using indirect immunofluorescence staining of HSV-1-infected cells: large replication compartments, small compartments, and no specific intranuclear localization of ICP8. Cells that form large replication compartments replicate viral DNA and express late genes. Cells that form small replication compartments replicate viral DNA but do not express late genes, while cells without viral replication compartments are incapable of both DNA replication and late gene expression. The d105 ICP8 protein blocks formation of prereplicative sites and large replication compartments in 80% of infected cells and formation of large replication compartments in the remaining 20% of infected cells. The phenotype of d105 suggests a correlation between formation of large replication compartments and late gene expression and a role for intranuclear rearrangement of viral DNA and bound proteins in activation of late gene transcription. Thus, these results provide evidence for specialized machinery for late gene expression within replication compartments.

Treatment of a thyrotropinoma with octreotide-LAR in a patient with multiple endocrine neoplasia-1

OBJECTIVE

To note that a thyrotropin (TSH)-secreting macroadenoma may be part of the multiple endocrine neoplasia-1 (MEN-1) syndrome and to report the use of octreotide-LAR (OCT-LAR) to treat a TSH-secreting macroadenoma in a patient with MEN-1 with previous surgery for hyperparathyroidism and gastrinoma.

METHODS

We present a patient with a TSH-secreting pituitary macroadenoma and report the results of her endocrine, genetic, radiologic, and nuclear medicine testing and her response to treatment with octreotide (OCT), octreotide-LAR, and estrogen.

RESULTS

This patient's TSH-induced hyperthyroidism responded to octreotide for 5 months and octreotide-LAR for more than 11 months. Her hypercalcemia normalized while she was taking estrogen. Her genetic testing is reported to show a genetic defect that is typical of patients with MEN-1.

CONCLUSION

This report describes: (1) The use of octreotide-LAR to treat both a TSH-secreting pituitary tumor and a gastrinoma over 12 months; (2) the importance of including these tumors into the MEN-1 syndrome with its attendant implications; and (3) a genetic defect, typical of patients with MEN-1, associated with this tumor.

How the propagation of error through stochastic counters affects time discrimination and other psychophysical judgments

The performance of fallible counters is investigated in the context of pacemaker-counter models of interval timing. Failure to reliably transmit signals from one stage of a counter to the next generates periodicity in mean and variance of counts registered, with means power functions of input and standard deviations approximately proportional to the means (Weber's law). The transition diagrams and matrices of the counter are self-similar: Their eigenvalues have a fractal form and closely approximate Julia sets. The distributions of counts registered and of hitting times approximate Weibull densities, which provide the foundation for a signal-detection model of discrimination. Different schemes for weighting the values of each stage may be established by conditioning. As higher order stages of a cascade come on-line the veridicality of lower order stages degrades, leading to scale-invariance in error. The capacity of a counter is more likely to be limited by fallible transmission between stages than by a paucity of stages. Probabilities of successful transmission between stages of a binary counter around 0.98 yield predictions consistent with performance in temporal discrimination and production and with channel capacities for identification of unidimensional stimuli.

Differential attrition rates and active parental consent

Active parental consent in survey research poses ethical and practical concerns. One common argument against the requirement of active consent procedures is its effect on participation rates. There is additional concern that higher risk groups may be underrepresented in the final sample. Empirical support of differential attrition, however, is lacking. In the current multisite longitudinal study, passive consent procedures were approved for the collection of pretest data. For subsequent years of data collection, active parental consent procedures were required. In this article, we use the pretest data to examine demographic, attitudinal, and behavioral differences between those students for whom active consent was provided and those for whom active consent was either denied or for whom no response was received. The results indicate that active consent procedures produce deleterious effects on participation rates and lead to an underrepresentation of at-risk youth in the sample.

Reality check. Evaluating a school-based gang prevention model

The Gang Resistance Education and Training (G.R.E.A.T.) program is a school-based gang prevention initiative developed in 1991 through the collaborative efforts of the Bureau of Alcohol, Tobacco, and Firearms, the Federal Law Enforcement Training Center, and the Phoenix Police Department. Uniformed law enforcement officers, certified as G.R.E.A.T. instructors, teach the 9-week curriculum to middle students. In 1994, the National Institute of Justice funded a national evaluation of the G.R.E.A.T. program. The process evaluation component of this larger study is reported. First, results of on-site observations of the G.R.E.A.T. Officer Training program, including an overview of the training activities, and the authors' assessment of the training process are reported. Second, observations of the implementation of the program by officers at six sites are reported. Of primary concern was whether the program delivered to students was similar to the program taught to the officers during the G.R.E.A.T. Officer Training.

Effect of palytoxin on endothelium-dependent and -independent relaxation in rat aortic rings

Endothelium-intact rat aortic rings were incubated with palytoxin (PTX, 10(-11)-10(-9)M, 10 min) in oxygenated (O2 95%, CO2 5%) baths. Phenylephrine (PE)-contracted vascular rings demonstrated decreasing relaxation to acetylcholine (ACh), depending upon PTX incubation in a dose-dependent manner; however, sodium nitroprusside (NaNP) persisted in returning the ring to its pre-PE tension. After incubation with PTX, relaxation to the receptor-independent, endothelium-dependent relaxant A23187 was also attenuated. Thus, endothelium-dependent mechanism(s) normally responsive to both ACh and A23187, stimulators of nitric oxide (NO) release, were disrupted. Following incubation with PTX, endothelium-independent relaxation to NaNP remained intact but relaxation to atriopeptin II (APII) decreased. Electron microscopy demonstrated microvesiculation of endothelial cell cytoplasm and an irregular luminal surface following incubation with PTX. The intact response to NaNP, despite the loss of relaxation to ACh, indicated that soluble guanylate cyclase was not affected by PTX. However, loss of relaxation to AP-II, involving particulate guanylate cyclase of vascular smooth muscle (VSM), was inhibited by PTX pre-incubation. Determination of the site(s) of action of PTX requires further study.

Non-specific binding of palytoxin to plastic surfaces

The changes in blood pressure induced by palytoxin (PTX) administered intravenously through polyethylene (PE) tubing were varied, suggesting either non-specific binding of the toxin to PE or deactivation. By spectrophotometry and HPLC, we found that PTX bound non-specifically to PE tubing and that this binding was attenuated by adding 0.1% rat serum albumin. Furthermore, the chemical stability and activity of PTX were not affected by exposure to room light and/or room temperature. Biological deactivation was excluded as a cause of the observed variability because the hypertensive and lethal effects of infused PTX, delayed with simultaneous administration of sodium nitroprusside (NNP), were in full evidence when the NNP was discontinued 35 min later.

Clinical and epidemiological features of neurotoxic shellfish poisoning in North Carolina

BACKGROUND

In October 1987, a red tide due to P. brevis affected the North Carolina coast for the first time. The purpose of our study was to describe the clinical and epidemiological features of neurotoxic shellfish poisoning (NSP), an illness caused by eating shellfish contaminated with the neurotoxins of P. brevis.

METHODS

Active surveillance was established for cases of NSP. A descriptive study of the NSP cases was then completed.

RESULTS

Forty-eight persons, who had eaten oysters at 20 meals, met the case definition. A variety of gastrointestinal tract and neurological symptoms were reported. The illnesses were generally mild and of short duration, and there were no deaths. Forty-one (85 percent) affected persons lived in five communities located within a 70-kilometer area along the coast. Cases occurred from October 27 to December 9; 27 (56 percent) of the cases occurred before the first closure of affected shellfish waters on November 2. There was a significant increase in the illness attack rate with an increase in the number of oysters eaten.

CONCLUSIONS

Routine monitoring of coastal waters for P. brevis is needed to facilitate earlier recognition of red tides, closure of affected areas, and education of the public before substantial exposure to contaminated shellfish occurs.

Pineal function in burns: melatonin is not a marker for general sympathetic activity

Burn injury in humans or rats is a model of marked elevation of general sympathetic activity for weeks, manifested in part by increased heart rate, metabolic rate, core temperature, and plasma and urinary catecholamines. Plasma melatonin was sampled at 2-h intervals for 24 h in 9 control subjects and 11 patients with severe burn injury. Daytime melatonin was not different between the groups, but nighttime values were significantly lower in the burn patients. A nocturnal surge was still significant in the patients. Resting heart rate and rectal temperature were elevated in the burn patients. In male Sprague-Dawley rats, pineal melatonin content did not differ between controls and those with an experimental burn at 4 h into the light phase nor during the nocturnal surge. Male Syrian hamsters with burns had lower daytime pineal melatonin content than did controls, but the nocturnal surge in pineal melatonin was not significantly different between groups, nor was daytime morning serum melatonin. Sympathetic activity appears partitioned, with that controlling melatonin (nocturnal surge) regulated independently. In agreement with our previous findings in other models, melatonin is not a marker for general sympathetic activity, even following severe burn injury.