Biomolecular characterization of 3500-year-old ancient Egyptian mummification balms from the Valley of the Kings.

Ancient Egyptian mummification was practiced for nearly 4000 years as a key feature of some of the most complex mortuary practices documented in the archaeological record. Embalming, the preservation of the body and organs of the deceased for the afterlife, was a central component of the Egyptian mummification process. Here, we combine GC-MS, HT-GC-MS, and LC-MS/MS analyses to examine mummification balms excavated more than a century ago by Howard Carter from Tomb KV42 in the Valley of the Kings. Balm residues were scraped from now empty canopic jars that once contained the mummified organs of the noble lady Senetnay, dating to the 18th dynasty, ca. 1450 BCE. Our analysis revealed balms consisting of beeswax, plant oil, fats, bitumen, Pinaceae resins, a balsamic substance, and dammar or Pistacia tree resin. These are the richest, most complex balms yet identified for this early time period and they shed light on balm ingredients for which there is limited information in Egyptian textual sources. They highlight both the exceptional status of Senetnay and the myriad trade connections of the Egyptians in the 2nd millennium BCE. They further illustrate the excellent preservation possible even for organic remains long removed from their original archaeological context.

Radiation dose and leukemia risk in patients treated for cancer of the cervix.

To quantify the risk of radiation-induced leukemia and provide further information on the nature of the relationship between dose and response, a case-control study was undertaken in a cohort of over 150,000 women with invasive cancer of the uterine cervix. The cases either were reported to one of 17 population-based cancer registries or were treated in any of 16 oncologic clinics in Canada, Europe, and the United States. Four controls were individually matched to each of 195 cases of leukemia on the basis of age and calendar year when diagnosed with cervical cancer and survival time. Leukemia diagnoses were verified by one hematologist. Radiation dose to active bone marrow was estimated by medical physicists on the basis of the original radiotherapy records of study subjects. The risk of chronic lymphocytic leukemia, one of the few malignancies without evidence for an association with ionizing radiation, was not increased [relative risk (RR) = 1.03; n = 52]. However, for all other forms of leukemia taken together (n = 143), a twofold risk was evident (RR = 2.0; 90% confidence interval = 1.0-4.2). Risk increased with increasing radiation dose until average doses of about 400 rad (4 Gy) were reached and then decreased at higher doses. This pattern is consistent with experimental data for which the down-turn in risk at high doses has been interpreted as due to killing of potentially leukemic cells. The dose-response information was modeled with various RR functions, accounting for the nonhomogeneous distribution of radiation dose during radiotherapy. The local radiation doses to each of 14 bone marrow compartments for each patient were incorporated in the models, and the corresponding risks were summed. A good fit to the observed data was obtained with a linear-exponential function, which included a positive linear induction term and a negative exponential term. The estimate of the excess RR per rad was 0.9%, and the estimated RR at 100 rad (1 Gy) was 1.7. The model proposed in this study of risk proportional to mass exposed and of risk to an individual given by the sum of incremental risks to anatomic sites appears to be applicable to a wide range of dose distributions. Furthermore, the pattern of leukemia incidence associated with different levels of radiation dose is consistent with a model postulating increasing risk with increasing exposure, modified at high doses by increased frequency of cell death, which reduces risk.

An antidepressant mechanism of desipramine is to decrease tumor necrosis factor-alpha production culminating in increases in noradrenergic neurotransmission.

The monoamine theory of depression proposes decreased bioavailability of monoamines, such as norepinephrine (NE), as the underlying cause of depression. Thus, the antidepressant efficacy of NE-reuptake inhibitors such as desipramine is attributed to increases in synaptic concentrations of NE. The time difference between inhibition of reuptake and therapeutic efficacy, however, argues against this being the primary mechanism. If desipramine elicits its therapeutic efficacy by increasing NE release, in turn, increasing activation of the alpha(2)-adrenergic autoinhibitory receptor, then mimicking this increase with an exogenous agonist (clonidine) should support or even enhance the efficacy of the antidepressant. Intriguingly, simultaneous administration of clonidine with desipramine prevented the cellular and behavioral effects elicited by desipramine alone, in both acute and chronic administration paradigms. These results suggest the involvement of additional factor(s) in the mechanism of antidepressant action of this drug. Desipramine administration results in a virtual ablation of neuron-derived tumor necrosis factor-alpha (TNF), thus implicating an essential role of TNF in the therapeutic efficacy of this antidepressant. Additionally, following chronic administration of desipramine, TNF-regulation of NE release is transformed, from inhibition to facilitation. Here, we demonstrate that a transformation in TNF-regulation of NE release in the brain is a key element in the efficacy of this antidepressant. Interestingly, an increase in neurotransmission prior to the antidepressant's effect on TNF production prevents the efficacy of the antidepressant drug. Thus, the efficacy of desipramine is due to decreased levels of TNF in the brain induced by this drug, ultimately modifying noradrenergic neurotransmission.

Severe soft-tissue injury following intravenous infusion of phenytoin. Patient and drug administration risk factors.

From April 8, 1982, through June 1984, 11 patients in a single hospital experienced 17 episodes of limb edema and discoloration after the intravenous (IV) administration of phenytoin sodium (Dilantin). One patient required a below-the-elbow amputation; all other patients recovered. No single drug lot was implicated. A case-control study was performed using three controls for each case; controls received IV infusions of phenytoin and were hospitalized close in time to the case patients. Compared with controls, patients with reactions were more often female and elderly and had underlying cardiovascular disease. Affected patients also received phenytoin through an IV catheter smaller than 20 gauge (50% vs 6%), at a rate greater than 25 mg/min (63% vs 19%), and in two or more IV infusions of phenytoin given "IV push" at the same site (81% vs 24%). High-risk patients require careful monitoring and stricter guidelines for the IV administration of phenytoin.

Regulation of macrophage-derived tumor necrosis factor production by modification of adrenergic receptor sensitivity.

Catecholamines and prostaglandins are among the many diverse mediators which participate in an interactive communication between the nervous and immune systems. We have examined the response of murine peritoneal macrophages (M luminal diameter) to prostaglandin-E2 (PGE2) and the beta-adrenergic agonist isoproterenol. In the present study we found a relationship between the response elicited by PGE2 and a beta-adrenergic agonist, which in a fashion similar to the response of PGE2 on M luminal diameters suppresses lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) production. It has been established that exposure of M luminal diameters to PGE2 desensitizes the suppressive function of PGE2. In this study, prior exposure of M luminal diameters to a beta-adrenergic agonist and the effects on subsequent beta-adrenergic responses, as well as the relationship to PGE2 sensitivity was determined. Complete Freund's adjuvant-elicited M luminal diameters were incubated with or without either a beta-adrenergic agonist or antagonist. All groups of cells were then extensively washed, followed by incubation with LPS (100 ng/ml) with or without graded concentrations of PGE2 or the beta-adrenergic agonist isoproterenol. Supernatants were collected to determine TNF concentrations by a fibroblast cytolytic assay, and Northern blot analysis was used to determine changes in the regulation of TNF mRNA accumulation. Both isoproterenol and PGE2 inhibited LPS-stimulated TNF release and TNF mRNA accumulation. We have established M luminal diameters regulation of sensitivity to isoproterenol-induced suppression of TNF production. The isoproterenol concentration-effect curve was shifted to the right after pre-exposure of M luminal diameter to the beta-agonist, suggesting a desensitized beta-adrenergic receptor population. Further studies demonstrated that M luminal diameters pre-exposed to the beta-adrenergic antagonist, ICI 118.551, washed, and then challenged with LPS show an increased sensitivity for isoproterenol-induced suppression of TNF production. In addition, a decreased sensitivity of M luminal diameters to exogenous PGE2 was observed during the desensitization to the beta-adrenergic agonist. Although concomitant addition of isoproterenol increased PGE2-induced suppression of LPS-stimulated TNF production, M luminal diameter pre-exposed to isoproterenol (10(-6) M) demonstrated a decreased sensitivity for PGE2-induced suppression of LPS-stimulated TNF production and TNF mRNA accumulation. Our results show that the effects observed after acute administration of a mediator may be different when M luminal diameters have been previously exposed to that or other mediators. These investigations support a role for mediators released from the nervous system to regulate the release of a cytokine needed to maintain inflammatory responses.

Temporal regulation by adrenergic receptor stimulation of macrophage (M phi)-derived tumor necrosis factor (TNF) production post-LPS challenge.

Macrophage (M phi) responsiveness can be regulated by various mediators, including those which emanate from, and mimic, the sympathetic nervous system. Whereas beta-adrenergic agonists suppress, alpha 2-adrenergic agonists augment lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF) production and gene expressed. The susceptibility of M phi s to regulation of LPS-induced TNF production and mRNA accumulation was examined following beta-adrenergic and alpha 2-adrenergic receptor activation at specific time points post-LPS challenge. Complete Freund's adjuvant-elicited murine M phi s were incubated with LPS (30 ng/ml) in the presence or absence of adrenergic agonists or antagonists. We assessed the susceptibility of immunologically-activated M phi s to adrenergic receptor regulation: a) during the 1 h delay in the production of TNF after LPS-stimulation, and b) during the rapid increase in TNF production which follows. Disparate responsiveness of M phi s to adrenergic drugs was observed during this time course of TNF production and TNF mRNA accumulation. In particular, while the concomitant addition of an alpha 2-adrenergic antagonist and LPS resulted in 45% suppression of TNF production, this selective blockade of alpha 2-adrenergic receptors on M phi s was equally effective throughout the first 45 min post-LPS challenge. After this initial period, the alpha 2-adrenergic receptor became progressively less responsive as demonstrated by the delayed addition of yohimbine (10(-5) M) post-LPS challenge. The addition of the selective alpha 2-adrenergic agonist UK-14304 (10(-7) M) to LPS-activated M phi s augmented TNF mRNA accumulation. However, this augmentation was even greater when the addition of the alpha 2-adrenergic agonist was delayed post-LPS challenge. It was also shown that the beta-adrenergic agonist isoproterenol (10(-6) M) produced maximum suppression of TNF production within the first 1.5 h post-LPS challenge. Suppression by isoproterenol (10(-6) M) of TNF mRNA accumulation occurred throughout the 2-h period assessed post-LPS stimulation of M phi s. The decline in isoproterenol-induced regulation was accompanied by an elevation in beta 2-adrenergic receptor mRNA accumulation. Furthermore, suppression of TNF production induced by a maximum concentration of isoproterenol was observed at various LPS concentrations (0.001-1000 ng/ml), although this was not as pronounced a suppression as demonstrated for dibutyrl cAMP. These results demonstrate that the susceptibility of M phi s to adrenergic receptor regulation changes throughout the time period necessary for gene activation and ultimate release of TNF. Thus, the production of TNF during LPS-dependent disease states may be regulated by adrenergic mediators throughout different temporal windows, better explaining the role played by the nervous system.

Antidepressant drug administration modifies the interactive relationship between alpha(2)-adrenergic sensitivity and levels of TNF in the rat brain.

A reciprocally permissive interaction occurs between cellular responses elicited by the pleiotropic cytokine tumor necrosis factor-alpha (TNF) and alpha(2)-adrenergic receptor activation, such that each may adapt in response to modifications in the other's effects. Changes in presynaptic adrenergic sensitivity as well as neuronal sensitivity to TNF have been implicated in the mechanism of action of antidepressant drugs. The present study examines the influence of alpha(2)-adrenergic receptor activation on levels of TNF in regions of the brain associated with adrenergic function and the expression of mood. Additionally, the role of TNF as a neuromodulator is demonstrated by in vivo microinfusion of rrTNF proximal to the hippocampus. Administration to rats of an alpha(2)-adrenergic receptor agonist (clonidine) decreases levels of TNF in homogenates of rat locus coeruleus and hippocampus within 7.5 min. Chronic (14 days) administration of the antidepressant drugs desipramine or zimelidine transforms alpha(2)-adrenergic receptor-dependent decreases in TNF levels to increases in levels of TNF in the locus coeruleus. This transformation to an increase in total levels of TNF also occurs, although transiently, in the hippocampus following acute (1 day) antidepressant drug administration. The effect of TNF on presynaptic alpha(2)-adrenergic sensitivity was also investigated. Field stimulation of hippocampal slices from rats microinfused with rrTNF proximal to the hippocampus for 14 days demonstrates a decrease in fractional release of [3H]NE and an increase in alpha(2)-adrenergic autoreceptor sensitivity. These data demonstrate a mutual dependence between alpha(2)-adrenergic receptor activation and levels of TNF in the central nervous system that would culminate in an increase in neurotransmitter release following antidepressant drug administration.

Changes in noradrenergic sensitivity to tumor necrosis factor-alpha in brains of rats administered clonidine.

Tumor necrosis factor-alpha (TNF alpha) and the imidazoline clonidine modulate norepinephrine (NE) release from noradrenergic nerve terminals in the central nervous system. The present study demonstrates an intrinsic association between presynaptic alpha 2-adrenergic receptor sensitivity and TNF alpha responsiveness in governing this NE release. Superfusion and electrical field stimulation were applied to a series of rat hippocampal brain slices in order to study the regulation of [3H]-NE release. The alpha 2-adrenergic agonist clonidine and the cytokine TNF alpha concentration-dependently inhibit [3H]-NE release; whereas, the alpha 2-adrenergic antagonist idazoxan potentiates [3H]-NE release. The fractional release of [3H]-NE during field stimulation of control hippocampal slices was decreased by the addition of TNF alpha in a concentration-dependent manner, an effect which was potentiated by the alpha 2-adrenergic antagonist idazoxan; whereas, TNF alpha attenuated the concentration-dependent potentiating effect of idazoxan. Furthermore, constitutive TNF alpha, demonstrated to be present in several brain areas, was significantly decreased following administration of the alpha 2-adrenergic agonist clonidine (0.6 mg/kg, i.p., twice daily) to rats for either 1 or 14 days, without a change in TNF alpha mRNA accumulation. We next investigated whether the presynaptic sensitivity to TNF alpha was changed after clonidine administration to rats. TNF alpha enhanced, rather than inhibited, [3H]-NE release after 1 day of clonidine administration, while a suppressed sensitivity to TNF alpha was observed in the hippocampus after 14 days of clonidine administration. In addition, in the presence of idazoxan, TNF alpha potentiation of [3H]-NE release after 1 day clonidine administration was reversed to a decreased inhibition as compared to control slices exposed to idazoxan. Therefore, the temporary reversal in the presynaptic TNF alpha response after 1 day of clonidine administration illustrates a mechanism of action for its persistent antihypertensive effect, its transient sedative and antihyperpathic effects, and its acute ability to promote antidepressants. These results demonstrate a novel role for an immune mediator in the central nervous system, and demonstrates that presynaptic TNF alpha responsiveness is intimately associated with adrenergic receptor sensitivity.

Beta-adrenergic receptor regulation of macrophage-derived tumor necrosis factor-alpha production from rats with experimental arthritis.

Prostaglandin E2 (PGE2) and beta-adrenergic agonists can suppress lipopolysaccharide-induced tumor necrosis factor-alpha (TNF) production from elicited macrophages. We assessed the responsiveness of rat peritoneal macrophages to PGE2 and the beta-adrenergic agonist isoproterenol during immunologically-mediated arthritis. We assessed macrophage sensitivity to these mediators from resident macrophages and macrophages elicited with either streptococcal cell wall or complete Freund's adjuvant. Peritoneal macrophages were obtained from female Lewis rats that were (1) injected with complete Freund's adjuvant and non-arthritic (CFA); (2) injected with streptococcal cell wall and arthritic (ART); (3) injected with streptococcal cell wall and non-reactive (NON) and (4) non-elicited resident macrophages (RES). When challenged with graded concentrations of lipopolysaccharide (0.1 to 10,000 ng/ml), macrophages obtained from each group of rats released TNF in a concentration-dependent manner, with macrophages from arthritic rats (ART) producing the greatest amount of TNF (p < 0.001). While PGE2 suppressed lipopolysaccharide (100 ng/ml) stimulated TNF production in a concentration-dependent manner in all groups, the greatest sensitivity to PGE2 was observed with macrophages obtained from rats which received streptococcal cell wall when compared to both complete Freund's adjuvant-elicited and resident macrophages (p < 0.05). The beta-adrenergic agonist isoproterenol also inhibited lipopolysaccharide-stimulated TNF production from macrophages in all groups. In addition, the specific beta 2-adrenergic antagonist, ICI 118.551, shifted isoproterenol concentration-effect curves to the right (p < 0.01). Minimal responsiveness to isoproterenol was observed with resident peritoneal macrophages. Maximum isoproterenol-induced inhibition of TNF production was observed with complete Freund's adjuvant-elicited macrophages, and significantly less in macrophages of streptococcal cell wall-injected rats. Of particular interest, macrophages obtained from streptococcal cell wall-injected rats, which became arthritic, were significantly less sensitive to isoproterenol than those which did not develop arthritis (p < 0.02). In addition, these changes in sensitivity were not reflected by changes in the sensitivity of both CFA and ART groups to dibutyryl cAMP. The present study demonstrates a shift in the balance between inhibitory mediator responses in rats inoculated with one of two different adjuvants. These investigations support the role of PGE2 and a neurotransmitter as immunomodulating compounds which may effectively maintain an inflammatory lesion such as arthritis.

Adrenergic regulation of macrophage-derived tumor necrosis factor-alpha generation during a chronic polyarthritis pain model.

Increases in the levels of proinflammatory cytokines, such as TNF alpha, have been intricately linked with arthritis and the pathogenesis of several models of neuropathic pain. In addition, arthritis (as well as other types of persistent pain) is associated with increased sympathetic activity and alterations of other responses in autonomic nervous activity. Adrenergic regulation of LPS-stimulated TNF production by M phi isolated from rats with streptococcal-cell-wall (SCW)-induced arthritis has been examined. Serum TNF levels and the cellular composition of peritoneal exudates have also been assessed. M phi were obtained from: (1) normal control rats, (2) animals injected with complete Freund's adjuvant (CFA), 3 rats injected with SCW and arthritic, and (4) those injected with SCW, which failed to develop arthritis. Serum levels of TNF alpha in rats that develop arthritis are significantly greater (2.4 fold) than levels from the other groups. The proportion of OX19-positive T cell subpopulations are the same in peritoneal exudates from all groups. Immunocytochemical staining also reveals differences between M phi subgroups in the degree of activation. Peritoneal exudates from rats that develop arthritis contain a greater proportion of the high TNF producing subclass of M phi, as identified by positive ED3 staining (p < 0.001). In contrast, Ia antigen presenting M phi (OX6-positive) in the peritoneal exudate cells are only elevated in rats administered CFA. The selective blockade of adrenergic receptors by idazoxan or propranolol demonstrates that the constitutive involvement of either alpha 2 or beta-adrenergic regulation of M phi-derived TNF production is pronounced in rats with arthritis (p < 0.001). These investigations demonstrate a distinctive pattern of peripheral M phi populations in rats that develop chronic polyarthritic pain. We believe that identification of interactions between the adrenergic responses and proinflammatory cytokines will lead to the development of improved strategies to treat patients with chronic pain.

Neuronal-associated tumor necrosis factor (TNF alpha): its role in noradrenergic functioning and modification of its expression following antidepressant drug administration.

Tumor necrosis factor-alpha (TNF alpha) and the alpha 2-adrenergic agonist clonidine regulate norepinephrine (NE) release from noradrenergic nerve terminals in the central nervous system (CNS). In the present study, superfusion and electrical field stimulation were applied to a series of rat hippocampal brain slices in order to investigate the regulation of [3H]-NE release. NE release had been previously determined to be decreased by TNF alpha in a concentration-dependent manner, an effect which was potentiated by the alpha 2-adrenergic antagonist idazoxan. Presently, we demonstrate that similar to alpha 2-adrenergic activation, TNF alpha regulation of NE release in a region of the brain rich in noradrenergic nerve terminals, is dependent upon the frequency of electrical stimulation applied to the hippocampal slice. Furthermore, immunoperoxidase staining has verified our previous findings of constitutive TNF alpha protein in the rat brain. Staining for TNF alpha appears to be largely localized to neurons and neuronal processes, further substantiating the proposal that TNF alpha is either synthesized de novo or is accumulated in and released by neurons. After administration of the tricyclic antidepressant desipramine, tissue sections obtained from the rat hippocampus and locus coeruleus are devoid of neuronal-associated TNF alpha immunoreactivity. TNF alpha localization in neurons and its modification of NE release comparable to alpha 2-adrenergic receptor activation, explains a functional role for the cytokine as a neuromodulator in the CNS.

Cancer mortality following cardiac catheterization: a preliminary follow-up study on 4,891 irradiated children.

A retrospective cohort study was conducted on the risk of radiation-induced cancer mortality following cardiac catheterization. The study included 4,891 children with congenital heart disease who were assessed by cardiac catheterization during 1946 to 1968 at The Hospital for Sick Children, Toronto. The cohort was matched against the Ontario cancer death file from 1950 to 1975. The average period of follow-up was 13 years and more than 66,000 person-years have been accrued from the cohort. No deaths from breast cancer or thyroid cancer were identified. Five cancer deaths were observed and compared with 4.8 expected deaths based on Ontario cancer death rates. The five cancer deaths resulted from three leukemias, one Wilms' tumor, and one unspecified nervous system tumor. The preliminary findings did not demonstrate a significant leukemia risk arising from diagnostic cardiac catheterizations. Continued follow-up of this cohort is required to evaluate the risk of breast and thyroid cancers which can occur more than 20 years following radiation exposure.

Fatal farm injuries among young children.

Death certificate data concerning farm-related injury deaths among children 0 to 9 years of age in Wisconsin and Illinois for the period of 1979 to 1985 were reviewed. Average annual farm-related injury death rates were 3.2 per 100,000 rural children in Wisconsin (62 deaths) and 1.5 per 100,000 in Illinois (32 deaths). Rates were three times higher among boys than girls. The occurrence of two harvest-related peaks and the absence of fatality in children less than 1 year of age suggest that presence of children on the farm when supervision is diminished is a key factor in farm-related fatalities. Moving machinery (tractors, wagons, and trucks) was the source of injury in approximately 55% of all deaths. Drowning accounted for 15% of all farm-related deaths. Two fatalities related to gravity box wagons could have easily been prevented with simple safety devices. These findings suggest a need for developing environmental interventions in farms. This will require the allocation of more resources to farm safety programs and a revision of current farm safety legislation.

Tumor necrosis factor-alpha: presynaptic sensitivity is modified after antidepressant drug administration.

Presynaptic adrenergic functioning was coupled to cytokine sensitivity in order to further establish the mechanism of action of a tricyclic antidepressant drug. Antidepressant administration of desipramine to rats twice-daily for 2 weeks increased hippocampal TNF levels and transformed the presynaptic TNF response. One day of desipramine administration resulted in increased locus coeruleus TNF mRNA accumulation and, simultaneously, hippocampal TNF levels escalated. The fractional release of [3H]norepinephrine during field stimulation of control hippocampal slices was decreased by the addition of TNF in a concentration-dependent manner, an effect which was potentiated by the alpha 2-adrenergic antagonist idazoxan. While no change in sensitivity to TNF was observed in the hippocampus after one day of desipramine administration, TNF enhanced, rather than inhibited [3H]norepinephrine release after 14 days. In addition, TNF potentiation of [3H]norepinephrine release after chronic desipramine administration was reversed in the presence of idazoxan to a greater inhibition than in control slices exposed to idazoxan. Therefore, TNF-induced regulation of [3H]norepinephrine release appears to be associated with an alteration of alpha 2-adrenergic receptor responsiveness. The reversal in presynaptic TNF responsiveness after 14 days of tricyclic antidepressant drug administration describes a mechanism of action for their delayed clinical effect.

Brain-derived TNFalpha: involvement in neuroplastic changes implicated in the conscious perception of persistent pain.

The pleiotropic cytokine tumor necrosis factor-alpha (TNFalpha) is implicated in the development of persistent pain through its actions in the periphery and in the central nervous system (CNS). Activation of the alpha(2)-adrenergic receptor is associated with modulation of pain, possibly through its autoregulatory effect on norepinephrine (NE) release in the CNS. The present study employs a chronic constriction nerve injury (CCI) pain model to demonstrate the interactive role of presynaptic sensitivity to TNFalpha and the alpha(2)-adrenergic autoreceptor in the pathogenesis of neuropathic pain. Accumulation of TNFalpha is increased initially in a region of the brain containing the locus coeruleus (LC) at day 4 post-ligature placement, followed by an increase in TNFalpha in the hippocampus at day 8 post-ligature placement, coincident with hyperalgesia. Levels of TNFalpha in the thoraco-lumbar spinal cord are also increased at day 8 post-ligature placement. Concurrently, alpha(2)-adrenergic receptor and TNFalpha-induced inhibition of NE release are increased, and stimulated NE release is decreased in superfused hippocampal slices isolated at day 8 post-ligature placement. Stimulated NE release is also decreased in spinal cord slices (lumbar region) from animals undergoing CCI, although in contrast to that which occurs in the hippocampus, alpha(2)-adrenergic receptor inhibition of NE release is not changed. These results indicate an important role that TNFalpha plays in adrenergic neuroplastic changes in a region of the brain that, among its many functions, appears to be a crucial link in the conscious perception of pain. We predict that neuroplastic changes, involving increased functional responses of alpha(2)-adrenergic autoreceptors and increased presynaptic sensitivity to TNFalpha, culminate in decreased NE release in the CNS. These neuroplastic changes provide a mechanism for the role of CNS-derived TNFalpha in the pathogenesis of persistent pain.

Brain-derived TNFalpha mediates neuropathic pain.

Neuropathic pain is a chronic pain state that develops a central component following acute nerve injury. However, the pathogenic mechanisms involved in the expression of this central component are not completely understood. We have investigated the role of brain-associated TNF in the evolution of hyperalgesia in the chronic constriction injury (CCI) model of neuropathic pain. Thermal nociceptive threshold has been assessed in rats (male, Sprague-Dawley) that have undergone loose, chromic gut ligature placement around the sciatic nerve. Total levels of TNF in regions of the brain, spinal cord and plasma have been assayed (WEHI-13VAR bioassay). Bioactive TNF levels are elevated in the hippocampus. During the period of injury, hippocampal noradrenergic neurotransmission demonstrates a decrease in stimulated norepinephrine (NE) release, concomitant with elevated hippocampal TNF levels. Continuous intracerebroventricular (i.c.v.) microinfusion of TNF-antibodies (Abs) starting at four days, but not six days, following ligature placement completely abolishes the hyperalgesic response characteristic of this model, as assessed by the 58 degrees C hot-plate test. Antibody infusion does not decrease spinal cord or plasma levels of TNF. Continuous i.c.v. microinfusion of rrTNF alpha exacerbates the hyperalgesic response by ligatured animals, and induces a hyperalgesic response in animals not receiving ligatures. Likewise, field-stimulated hippocampal adrenergic neurotransmission is decreased upon continuous i.c.v. microinfusion of TNF. These results indicate an important role of brain-derived TNF, both in the pathology of neuropathic pain, as well as in fundamental pain perception.

Changes in alpha 2-adrenoceptor number and function in brains of morphine-dependent rats.

The effects of long-term treatment of rats with morphine sulfate were assessed upon the specific binding of [3H]clonidine to alpha 2-adrenoceptors on neural membranes isolated from various brain areas and upon the function of presynaptic alpha 2-adrenoceptors during field stimulation of hippocampal slices. Rats were injected with morphine every 8 h for 14 days with doses which started at 10 mg/kg per injection i.p., and which increased every 3 days to a final dose of 100 mg/kg per injection on the last 2 days. At 8 and 32 h after the last injection the Bmax for [3H]clonidine binding to neural membranes from various brain areas was significantly decreased. At the same times, the fractional release of [3H]noradrenaline during field stimulation of hippocampal slices was increased and the sensitivity of the hippocampal slice to clonidine was reduced which indicated the development of a functional subsensitivity of the presynaptic alpha 2-adrenoceptor. These changes in receptor function persisted at 72 h after the last morphine injection although at this time there were marked increases over control values in [3H]clonidine binding to membranes from all rat brain areas except the caudate nucleus. These findings suggest that changes in alpha 2-adrenoceptor number and function which develop during long-term morphine administration might play an important role in opiate dependence.

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. I. Birth defects and developmental disorders.

Members of the workgroup on birth defects and developmental disorders discussed methods to assess structural anomalies, genetic changes and mutations, fetal and infant mortality, functional deficits, and impaired fetal and neonatal growth. Tier 1 assessments for all five adverse reproductive outcomes consist of questionnaires and reviews of medical records rather than laboratory testing of biologic specimens. The work-group members noted a role for neurodevelopmental testing and for limited genetic studies, such as karyotyping in Tier 2 assessments. Emerging methodologies to identify chromosomal aberrations, DNA adducts, and repair inhibition were reserved for Tier 3.

Hyperaluminemia in renal failure: the influence of age and citrate intake.

Following the occurrence of aluminum encephalopathy in four patients with chronic renal failure, we studied 34 azotemic patients seen during the same year and five volunteers who took varying combinations of aluminum hydroxide and an alkalinizing citrate (Shohl's) solution. We found that the four encephalopathic cases were older than the 34 azotemic patients (68 years +/- 14 SD, vs 50 +/- 13, p less than 0.05), had a higher mean serum aluminum value (727 micrograms/l +/- 320 vs 92 +/- 73, p less than 0.005), had taken more aluminum hydroxide (5 g/day +/- 0.9 vs 1.6 +/- 1.8, p less than 0.01), and more Shohl's solution (64 ml/day +/- 19 vs 20 +/- 29, p less than 0.01). In all 38 patients the serum aluminum values correlated directly with age (p = 0.01), aluminum hydroxide (p = 0.001) and concomitant citrate intake (p = 0.004). In the five healthy volunteers the 24-hour urinary aluminum excretion increased from a baseline of 22 micrograms +/- 19 SD to 167 +/- 109 (p = 0.05) during aluminum hydroxide intake, rising to 580 +/- 267 (p = 0.01) during the simultaneous intake of citrate and aluminum hydroxide. Corresponding serum aluminum values were 11 micrograms/l +/- 2 SD, 44 +/- 34 (p = 0.1), and 98 +/- 58 (p less than 0.05). Thus citrate seems to enhance aluminum absorption and may cause encephalopathy in patients with chronic renal failure, especially the elderly.

An evaluation of the Vermont worksite smoking law.

In view of the fact that the impact of statewide smoking laws on private worksite policies and the smoking behavior of employees has not been evaluated, two cross-sectional surveys were performed in Vermont to measure compliance with such a law: a random-digit telephone survey of employees and a subsequent mail survey of their employers. Employers were not aware that one of their employees had been surveyed. Roughly half (56 percent) of the employees and 66.5 percent of their employers described policies that are in compliance. Among all employers who described policies in compliance with the law, 68.1 percent of their employees also described compliant policies. Among all employees who described non-compliant policies, 48.8 percent had employers who described compliant policies. Overall, employees and employers agreed on how their policies stood with respect to compliance in 67.6 percent of cases. The prevalence and amount of smoking at work declined after the institution of the law but so did the prevalence and amount of smoking at home. Changes toward more restrictive policies were associated with reductions in cigarette consumption at work, but not with quitting. The study suggests that a large fraction of worksite smoking policies may not comply with a statewide worksite smoking law. The proportion of companies complying with such a law may be overestimated if information on compliance is obtained only from employers.