The effect of feeding on cerebrospinal fluid corticotropin-releasing hormone levels in humans

Corticotropin-releasing hormone (CRH) is a neuropeptide thought to play a role in appetite regulation. In this report, we used a serial cerebrospinal fluid (CSF) sampling technique to examine the relationship between CSF CRH, plasma ACTH and cortisol and perceptions of hunger and satiety in fasting and sated volunteers. CSF was withdrawn continuously from 11:00 AM to 5:00 PM via an indwelling subarachnoid catheter. Blood was withdrawn every 10 min via an antecubital vein catheter. Fed subjects received a meal at 1:00 PM. Subjects who were fed had lower post-prandial ratings on hunger scales and higher ratings on satiety scales. Fed subjects also had slightly lower levels of CSF CRH after feeding. Furthermore, fed subjects had higher ACTH and cortisol concentrations in the first 3 h; by the fourth h the opposite was true. Our findings do not support the hypothesis that CNS CRH is a central satiety factor in the human. Instead our findings of slightly diminished CSF CRH levels after feeding may be accounted for by the rises in glucocorticoids and their associated negative feedback effects on CNS CRH. Alternatively, our findings could also reflect changes in CRH levels associated with feeding in multiple brain areas and in the spinal cord with the net effect being in the negative direction.

Efficacy and safety of infliximab monotherapy for plaque-type psoriasis: a randomised trial

BACKGROUND

Currently available treatments for moderate to severe psoriasis are either incompletely effective in some patients, or are associated with toxic effects. Since tumour necrosis factor alpha (TNF-alpha) is thought to have a role in the pathogenesis of psoriasis, we did a double-blind, randomised trial to assess the clinical benefit and safety of infliximab-a monoclonal antibody against TNF-alpha.

METHODS

33 patients with moderate to severe plaque psoriasis were randomly assigned intravenous placebo (n=11), infliximab 5 mg/kg (n=11), or infliximab 10 mg/kg (n=11) at weeks 0, 2, and 6. Patients were assessed at week 10 for the primary endpoint (score on the physician's global assessment [PGA]). Analysis was by intention to treat.

FINDINGS

Of the 33 patients enrolled, three dropped out. Nine of 11 (82%) patients in the infliximab 5 mg/kg group were responders (good, excellent, or clear rating on PGA), compared with two of 11 (18%) in the placebo group (difference 64% [95% CI 20-89], p=0.0089), and ten of 11 (91%) patients in the infliximab 10 mg/kg group were responders (difference from placebo 73% [30-94], p=0.0019). The median time to response was 4 weeks for patients in both infliximab groups. There were no serious adverse events, and infliximab was well tolerated.

INTERPRETATION

In this controlled trial, patients receiving the anti-TNF-alpha agent infliximab as monotherapy experienced a high degree of clinical benefit and rapid time to response in the treatment of moderate to severe plaque psoriasis compared with patients who received placebo. These findings suggest that TNF-alpha has a pivotal role in the pathogenesis of psoriasis.

Hepatic toxicity and recovery of Fischer 344 rats following exposure to 2-aminoanthracene by intraperitoneal injection

Humans may be exposed to 2-aminoanthracene (2-AA), a substituted polycyclic aromatic hydrocarbon, and a recognized mutagen and carcinogen, through oral and respiratory routes from contact with a variety of environmental sources. For the present study, we sought to evaluate hepatic damage and recovery in Fischer 344 rats following multiple i.p. injections of 5 mg of 2-AA. Rats were injected weekly for up to 5 weeks. Subgroups were then allowed to recover for 1, 5, or 9 weeks, and biochemical and pathologic changes were evaluated. We observed that weight gains were reduced relative to controls for all groups receiving > or = 2 injections. Serum enzyme levels indicative of liver damage were evident and included alterations in serum aspartate aminotransferase, alkaline phosphatase, total protein, albumin, and globulin. These alterations usually returned to normal by 5 weeks following cessation of 2-AA administration. In contrast, histologic liver changes, including hepatocyte hypertrophy, biliary hyperplasia with oval cell proliferation, altered foci, nodular hyperplasia, and one hepatocellular adenoma became more severe with time. This experiment demonstrates patterns of hepatic damage and recovery in rats exposed to 2-AA.

Suppression of arylamine toxicity in the Fischer-344 rat following ingestion of a complex mixture

The toxic effects of a mixture of 2-aminoanthracene (2-AA), benzanthracene (BA), and dinitropyrene isomers (DNP), and the toxic effects of these compounds individually, were investigated in the Fischer-344 rat following dietary exposure via a powdered basal diet. Animals were sacrificed at 14-, 30-, and 80-days of dietary exposure. Exposure to dietary 2-AA alone induced anorexia, cachexia, variable mortality, and altered serum chemistry profiles in the F-344 rat. Reduced lymphocyte counts were also shown in rats exposed to 2-AA. A temporal pattern of effect of 2-AA dietary exposure was observed in the progression of hepatic lesions in exposed animals. Dietary exposure to either DNP isomers or BA at a 10-fold higher concentration in the diet, relative to 2-AA, did not induce detectable toxic responses. However, exposure of rats to a mixture of 2-AA, BA, and DNP isomers (100 mg/kg, 1.0 g/kg, and 1.0 g/kg of diet, respectively) resulted in the attenuation of toxic effects when compared to exposure of F-344 rats to 2-AA alone. These results indicate that the toxic effects of 2-AA are suppressed by co-administration of DNP and BA and suggest that compound interactions need to be considered when predicting the toxic potential of specific environmental pollutants.

Cerebrospinal fluid and plasma testosterone levels in post-traumatic stress disorder and tobacco dependence

BACKGROUND

Little is known about the relationship between endogenous central nervous system (CNS) testosterone and any psychiatric syndrome. The goal of this study was to screen for potential abnormalities in CNS testosterone levels in patients with post-traumatic stress disorder (PTSD) and/or tobacco dependence.

METHODS

We sampled cerebrospinal fluid (CSF) via a subarachnoid catheter over six hours and determined hourly basal CSF concentrations of testosterone in 11 combat veterans with PTSD and 12 normal volunteers. Smokers were abstinent for 11-17 h. Testosterone in CSF and matching plasma samples was assayed by radioimmunoassay.

RESULTS

A factor analysis for effects of PTSD status, smoking status and sample time revealed significant effects of PTSD or smoking status, but not time, on CSF testosterone. CSF testosterone levels were lower in individuals with PTSD as compared with normal volunteers. When divided by smoking status, abstinent smokers had mean CSF testosterone levels higher than those of non-smokers. A similar analysis of plasma testosterone revealed no significant effects of any factor on plasma testosterone.

CONCLUSIONS

These results indicate that CSF testosterone is significantly influenced by PTSD and smoking status. The exposure of the brain to altered levels of testosterone in smokers and patients with PTSD may have pathophysiologic significance in these conditions.

Plasma and cerebrospinal fluid interleukin-6 concentrations in posttraumatic stress disorder

BACKGROUND

Interleukin-6 (IL-6) secretion is suppressed by glucocorticoids and stimulated by catecholamines. Patients with posttraumatic stress disorder (PTSD) have decreased cortisol and increased catecholamine secretion. The purpose of this study was to assess the relation of IL-6 levels and hypothalamic-pituitary-adrenal and noradrenergic activity in patients with well-characterized PTSD.

METHODS

Cerebrospinal fluid (CSF) was withdrawn via a lumbar subarachnoid catheter over 6 h from 11 combat veterans with PTSD and 8 age- and sex-matched healthy controls. Blood was withdrawn concurrently. We measured IL-6, CRH and norepinephrine concentrations in the CSF and IL-6, ACTH, cortisol and norepinephrine in plasma.

RESULTS

Mean and median CSF IL-6 concentrations were higher in PTSD than in controls (mean = 24.0 vs. 14.6, p = 0.05; median = 26.7 vs. 14.3, p < 0.03): plasma IL-6 concentrations, however, were not different between the two groups. Plasma IL-6 and norepinephrine were positively correlated in the PTSD group (r = +0.74, p < 0.04), but not in normals (r = -0.55, p = 0.20).

CONCLUSIONS

PTSD patients have increased CSF concentrations of IL-6. Their plasma IL-6 is not elevated but is more tightly associated with noradrenergic output in these patients than in normals. Both findings might be explained by the low cortisol secretion previously reported in PTSD as a result of lowered glucocorticoid suppression of IL-6 secretion. High levels of CSF IL-6 may reflect neurodegeneration or compensatory neuroprotection.

Uncoupling of serotonergic and noradrenergic systems in depression: preliminary evidence from continuous cerebrospinal fluid sampling

We used the technique of continuous cerebrospinal fluid (CSF) sampling to test the following hypotheses regarding CNS monoaminergic systems in depression: (1) absolute concentrations of the informational substances tryptophan and 5-hydroxyindoleacetic acid (5-HIAA) are altered in the CNS of depressed patients (2) abnormal rhythms of tryptophan and/or 5-HIAA, or defective conversion of tryptophan to serotonin (5HT), exist in the CNS of depressed patients, and (3) the relationship between the CNS 5HT and norepinephrine (NE) systems is disrupted in depressed patients. We obtained 6-h concentration time series of tryptophan, 5-HIAA, NE, and 3-methoxy-4-hydroxyphenylglycol (MHPG) in the CSF of 10 patients with major depression and in 10 normal volunteers. No significant differences in CSF tryptophan, 5-HIAA, NE, or MHPG concentrations or rhythms were observed between normal volunteers and depressed patients. Neither were there differences in the mean tryptophan-to-serotonin ratio. However, a negative linear relationship was observed between mean concentrations of 5-HIAA and NE in the CSF of the normal volunteers (r = 0.916 [r2 = 0.839], df = 9, P < 0.001) while, in contrast, depressed patients showed no such relationship (r = +0.094 [r2 = 0.00877], df = 9, n.s.). Furthermore, the correlation coefficients expressing the relationship between CSF MHPG and CSF 5-HIAA within the normal and depressed groups were significantly different. These data support the hypothesis that a disturbance in the interaction between the serotonergic and noradrenergic systems can exist in depressive illness in the absence of any simple 5HT or NE deficit or surplus.

Eradication of infection with Helicobacter spp. by use of neonatal transfer

BACKGROUND AND PURPOSE

Efficient methods for detection and elimination of Helicobacter spp. infections are needed to facilitate the development of Helicobacter-free mouse colonies. We developed an inexpensive, high-throughput method for preparation of fecal DNA for Helicobacter polymerase chain reaction (PCR) assays.

METHODS

Fecal DNA was prepared by heating fecal pellets to 95 degrees C for 10 minutes in an alkaline solution, then adjusting the pH by addition of Tris buffer. This solution is used for PCR assays without purification of DNA. We then tested fostering as a method of generating Helicobacter-free mice. Litters born to Helicobacter-positive dams were transferred to Helicobacter-negative foster dams on the first day of life.

RESULTS

Fostered pups tested Helicobacter negative up to 89 days of age, whereas pups raised by Helicobacter-positive dams were all test positive by 19 days of age.

CONCLUSION

These simple methods provide an efficient system for the development of Helicobacter-free mouse colonies.

The effect of lumbar puncture stress on dopamine and serotonin metabolites in human cerebrospinal fluid

In order to examine concentrations of cerebrospinal fluid (CSF) neurochemicals, the technique of lumbar puncture is typically used. However, the effect of the intrinsic stress of undergoing a lumbar puncture on CSF monoamine concentrations in humans has not yet been established. We used lumbar puncture followed 3 h later by continuous CSF sampling to examine the effect of lumbar puncture on levels of the dopamine and serotonin metabolites homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA), respectively. Additionally, we examined the effect of lumbar puncture on the CSF HVA to 5-HIAA ratio. Immediately post lumbar puncture, CSF concentrations of HVA and 5-HIAA were, respectively, only 51 and 54% of the mean levels detected hours later. However, the HVA to 5-HIAA ratio remained stable during lumbar puncture. While HVA and 5-HIAA levels in CSF obtained via lumbar puncture reflect highly variable responses to the stress of the procedure, the ratio of these metabolites is unaffected.

Cerebrospinal fluid and plasma leptin measurements: covariability with dopamine and cortisol in fasting humans

Leptin (OB protein) is an important signal in the regulation of energy balance. Leptin levels correlate with adiposity, but also decrease acutely with caloric restriction and increase with refeeding. The brain is an established critical site of leptin function, yet little is known about leptin concentrations in the central nervous system relative to plasma levels, psychiatric diagnoses, and other endocrine parameters. Therefore, using a novel ultrasensitive leptin assay, we explored relationships of human plasma and cerebrospinal fluid (CSF) leptin levels to body mass index, smoking, posttraumatic stress disorder diagnosis, and levels of dopamine, monoamine metabolites, beta-lipotropin, glucocorticoid, and thyroid and cytokine hormones. A strong linear relation between CSF and plasma leptin levels in the am (r = 0.63; P < 0.002) and afternoon (r = 0.90; P < 0.0001) was revealed. CSF and plasma leptin concentrations decreased during a 12- to 20-h period of fasting. A strong association was found between plasma leptin and CSF dopamine levels (r = 0.74; P < 0.01) as well as between CSF leptin levels and urinary free cortisol (r = 0.73; P < 0.01). Both of these parameters covaried with leptin independently of adiposity, as estimated by body mass index. Implications for leptin transport, regulation, and its potential role in therapeutic strategies for obesity and diabetes are discussed.

How well have diagnostic tests and therapies for gout been evaluated?

The first descriptions of gout can be traced to the dawn of recorded medical history, yet a number of controversies and unanswered questions remain regarding diagnosis and treatment of gout. Questions can still be posed about the need for crystal identification of all cases, the utility of a 24-hour urine collection for uric acid, and even the difficulty of choosing a technique for measurement of uric acid. Some time has elapsed since Mesner stated in 1623, "Love and gout are incurable." How far have we come? How have we evaluated different treatments for gout? Ongoing reviews of the Cochrane collaboration show that there is still very little reliable information based on randomized controlled trials on which to base treatment decisions in acute and chronic gout.

Serial CSF corticotropin-releasing hormone levels and adrenocortical activity in combat veterans with posttraumatic stress disorder

OBJECTIVE

The authors sought to carefully test, by using a technique of continuous CSF sampling, the hypothesis that basal elevations in CSF corticotropin-releasing hormone (CRH) concentrations exist in patients with posttraumatic stress disorder (PTSD). They also sought to assess the relationship among PTSD symptoms, adrenocortical activity, and CSF CRH levels.

METHOD

CSF was withdrawn by means of a flexible, indwelling subarachnoid catheter over a 6-hour period, and hourly CSF concentrations of CRH were determined for 11 well-characterized combat veterans with PTSD and 12 matched normal volunteers. Twenty-four-hour urinary-free cortisol excretion was also determined. PTSD and depressive symptoms were correlated with the neuroendocrine data.

RESULTS

Mean CSF CRH levels were significantly greater in PTSD patients than in normal subjects (55.2 [SD = 16.4] versus 42.3 pg/ml [SD = 15.6]). No correlation was found between CSF CRH concentrations and PTSD symptoms. While there was no significant difference between groups in 24-hour urinary-free cortisol excretion, the correlation between 24-hour urinary-free cortisol excretion and PTSD symptoms was negative and significant.

CONCLUSIONS

By using a serial CSF sampling technique, the authors found high basal CSF CRH concentrations and normal 24-hour urinary-free cortisol excretion in combat veterans with PTSD, a combination that appears to be unique among psychiatric conditions studied to date.

Establishment and validation of an isolated rat lung model for pulmonary metabolism studies

An isolated rat lung model was established and validated for use in pulmonary metabolism studies. During the establishment phase of the study, several problems were encountered and overcome in order to maintain the lungs in physiological condition. In the validation phase of the study, the lungs were removed, ventilated and perfused from 34 male Fischer 344 rats. After an equilibration period, lungs were ventilated and perfused for up to 4 h. Morphological, biochemical and functional parameters were evaluated to validate the physiological condition of the lungs. Morphological parameters included wet/dry lung weight ratios and gross and histological scoring for edema. Biochemical parameters included assays for tissue ATP and reduced glutathione content, glutathione reductase activity and glucose utilization. Functional parameters included changes in lung tidal volume, dynamic compliance and airway resistance. Results indicated that edema formation was only detected histologically, that lungs remained nearly biochemically normal for 210 min and that pulmonary function declined to about 80-90% of normal. Overall, these findings indicated that the isolated, perfused rat lung remained in acceptable physiological condition for ca. 210 min. This period of time should be adequate for conducting pulmonary metabolism studies with a variety of exogenous compounds.

Low CSF concentration of a dopamine metabolite in tobacco smokers

OBJECTIVE

To screen for dopaminergic abnormalities in tobacco smokers and patients with posttraumatic stress disorder (PTSD), the authors determined serial CSF and plasma concentrations of the dopamine metabolite homovanillic acid (HVA).

METHOD

Continuous subarachnoid sampling was used to obtain 37 serial CSF samples over 6 hours in 13 normal volunteers and 11 patients with combat-related PTSD; 10 smoked and 14 had never smoked. The smokers were abstinent from tobacco for 1 1 to 17 hours.

RESULTS

The smokers had markedly lower CSF, but not plasma, HVA levels. Their CSF HVA concentrations averaged only 54% of the concentrations of the nonsmokers, independent of diagnosis.

CONCLUSIONS

Smokers' low CSF concentrations of HVA may be associated either with chronic inhalation of nicotine or other constituents of tobacco smoke or with acute abstinence. Any possible basal dopaminergic abnormalities in patients with PTSD are small relative to the abnormalities associated with smoking.

Continuous covariability of dopamine and serotonin metabolites in human cerebrospinal fluid

BACKGROUND

Experiments in lower animals and humans have demonstrated the existence of functional interactions between serotonin and dopamine in neuronal tissue. However, the relationship between parameters of serotonin and dopamine neuronal activity over time within the central nervous system (CNS) of the individual human has not yet been established.

METHODS

We used continuous cerebrospinal fluid (CSF) sampling over 6 hours to test the hypothesis that the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the dopamine metabolite homovanillic acid (HVA) significantly covary in concentration over time. Two groups of normal volunteers (total n = 16) were studied at separate hospitals and CSF was assayed for 5-HIAA and HVA by high-performance liquid chromatography (HPLC). Three subjects underwent repeat CSF-withdrawal procedures after a 6-week interval.

RESULTS

Strong and sustained positive covariability in concentrations of HVA and 5-HIAA was observed in the CSF of individual humans. High intraindividual correlation coefficients were +0.897 and +0.871 in the two normal volunteer groups. The HVA to 5-HIAA concentration ratio in CSF was 2.2 +/- 0.7 with very little variability over intervals ranging from minutes to weeks.

CONCLUSIONS

The balance between CSF dopamine and serotonin metabolite concentrations remains relatively constant over time in healthy humans. Serial measures of CSF dopamine and serotonin metabolites within the same person could be an effective model in which to explore the interrelationships between these systems in various psychiatric syndromes, in response to drug treatment, and during provactive testing.

Experimental infection of inbred mouse strains with Spironucleus muris

Four inbred mouse strains: BALB/c ByJ, 129/J, C3H/HeJ, and DBA/lJ, differing in major histocompatibility type, were orally inoculated with 2 x 10(5) infectious cysts of Spironucleus muris. Fecal samples were collected for fecal cyst output prior to infection, and on days 2, 6, 7, 8, 9, 11, 13, 15, and 17 after infection. Following necropsy, formalin-fixed intestinal sections were examined for the presence of trophozoites. On post-inoculation days 6 and 8, mice of the 129/J strain shed significantly (p<0.05) fewer cysts than other strains. This pilot study suggests that major histocompatibility haplotype may influence susceptibility of inbred mouse strains to S. muris.

Natural pathogens of laboratory mice, rats, and rabbits and their effects on research

Laboratory mice, rats, and rabbits may harbor a variety of viral, bacterial, parasitic, and fungal agents. Frequently, these organisms cause no overt signs of disease. However, many of the natural pathogens of these laboratory animals may alter host physiology, rendering the host unsuitable for many experimental uses. While the number and prevalence of these pathogens have declined considerably, many still turn up in laboratory animals and represent unwanted variables in research. Investigators using mice, rats, and rabbits in biomedical experimentation should be aware of the profound effects that many of these agents can have on research.

Acute gouty arthritis is seasonal

OBJECTIVE

Information regarding effect of weather conditions on gout is sparse. We conducted a study in the USA to examine whether gout is seasonal.

METHODS

We reviewed synovial fluid (SF) analyses from our laboratory during 1990-1995 and identified 359 patients who had acute gouty attacks. All fluids of patients with acute gout had intracellular monosodium urate crystals and SF leukocyte counts > 2000/mm3 or more than 10 leukocytes per high power field (HPF). Retrospective chart review of all patients was performed to confirm a clinical picture of acute gout. A control group included 76 patients with acute pseudogout whose SF were analyzed during the same period and who had intracellular calcium pyrophosphate crystals and inflammatory leukocyte counts as in patients with gout.

RESULTS

Acute gout was most common during the spring; n = 115 (32%). Ninety (25%) patients had acute gout attacks in the fall; 81 (23%) had acute attacks during the summer; 73 (20%) had acute attacks in the winter. One-way analysis of variance (ANOVA) was used to compare the overall frequency of acute gout during the months and seasons. Using ANOVA, there was no overall statistically significant difference in the incidence of gout per season (p = 0.07), although it approached statistical significance. Acute gouty attacks were more common in the spring compared with winter (p = 0.002) and summer (p = 0.015). There was a trend but no statistically significant difference compared with fall. Winter was the season in which the fewest acute gouty cases were seen, although it was not statistically significant. No seasonal difference was seen in the pseudogout group. There was no correlation between either mean monthly temperature or humidity and the incidence of acute gouty attacks.

CONCLUSION

Acute gout attacks are significantly more common in the spring. No seasonal variation was seen in patients with acute pseudogout attacks.

Interpersonal trauma and animal-related experiences in female and male military veterans: implications for program development

Exposure to trauma is more frequent than was previously recognized. The prevalence and impact of trauma events, including trauma involving animals, was assessed in age-matched male and female veterans. High rates of exposure to at least one trauma event were reported by males (95%) and females (97%). Females were more likely to report sexual and physical abuse by a significant other. Both genders experienced higher trauma rates in the military than in civilian settings. A survey of animal-related experiences showed similar rates of losing a special pet, being frightened or hurt by an animal, witnessing or perpetrating violence toward animals, and having sexual interactions with animals. Almost one-third of the veterans showed evidence of post-traumatic stress disorder symptoms, highlighting the potential benefit of trauma screening to identify veterans in need of further evaluation and treatment.

Monosodium urate, hydroxyapatite, and calcium pyrophosphate crystals induce tumor necrosis factor-alpha expression in a mononuclear cell line

OBJECTIVE

Tumor necrosis factor-alpha (TNF-alpha) is thought to be important in chronic inflammation of joints characteristic of crystal induced arthritis. Monocytes are instrumental in maintaining that inflammation. We investigated production of mRNA and protein for TNF-alpha in vitro in a murine mononuclear cell line, after exposure to relevant crystal types.

METHODS

Using the cell line designated RAW 264.7, cells were grown in standard medium and exposed to varying amounts of monosodium urate (MSU), hydroxyapatite (HA), and calcium pyrophosphate dihydrate (CPPD) crystals for differing time periods. Analysis of TNF-alpha mRNA induced by such exposure was by Northern hybridization; analysis of TNF-alpha protein was by ELISA:

RESULTS

RNA analyses of cells treated with various levels of MSU, HA, and CPPD crystals showed strong induction of TNF-alpha transcripts. ELISA on culture supernatants confirmed high level TNF-alpha peptide secretion resulting from that transcriptional upregulation. Time course studies showed peak accumulation of TNF-alpha mRNA 1-6 h post-treatment. Study of the signalling pathway involved in TNF-alpha transcriptional upregulation indicated that increased phospholipase A2 activity was required.

CONCLUSION

These observations suggest that crystals in joints can directly stimulate production of TNF-alpha, and that the source of that cytokine may be the monocytes known to be present and playing an important role in chronic joint disease.

Relationship between posttraumatic stress disorder and self-reported physical symptoms in Persian Gulf War veterans

BACKGROUND

While prior studies show that combat veterans with posttraumatic stress disorder (PTSD) report more physical symptoms than veterans without PTSD, the link between PTSD and somatic complaints in Persian Gulf War veterans (PGWVs) is yet to be evaluated.

METHODS

A questionnaire booklet was completed by 188 PGWVs, of whom half were patients in a veterans health screening clinic and half were non-treatment-seeking volunteers on active duty. The booklet included the Combat Exposure Scale, the Mississippi Post-Traumatic Stress Disorder Scale (MPTSD), and a subjective symptom-based health questionnaire.

RESULTS

The 24 PGWVs (12.8%) with PTSD (MPTSD score > or = 116) reported more combat exposure (P = .02) and a greater number of physical symptoms (P = .001) than other PGWVs. Fatigue, nausea, muscle aches, dizziness, back pain, stomach ache, and numbness were much more likely to be reported by those with PTSD (MPTSD score > or = 116) than by those without PTSD (MPTSD score < or = 95).

CONCLUSIONS

Physicians examining PGWVs should be alert to the possibility of PTSD in this group and that those with PTSD are more likely to report physical symptoms that may overlap with those in Persian Gulf syndrome. Consequently, mental health screening is essential, since for those veterans with PTSD diagnosis of other coexisting conditions may be confounded and early effective treatment of their PTSD may be delayed. Also, given the increased reporting of certain symptoms by those with PTSD, those seeking the cause of Persian Gulf syndrome should control for PTSD when determining the symptom cluster that may constitute this condition.

Cerebrospinal fluid and plasma beta-endorphin in combat veterans with post-traumatic stress disorder

Opioid-mediated analgesia develops in experimental animals following traumatic stress and increased opioid-mediated analgesia has been observed in combat veterans with post-traumatic stress disorder (PTSD). These observations have led to the hypothesis that increased central nervous system (CNS) opioidergic activity exists in patients with PTSD. However, direct CNS data on opioid peptide concentrations and dynamics in patients with PTSD are lacking. We withdrew cerebrospinal fluid (CSF) via a flexible, indwelling subarachnoid catheter over a 6-h period and determined hourly CSF concentrations of immunoreactive beta-endorphin (ir beta END) in 10 well-characterized combat veterans with PTSD and nine matched normal volunteers. Blood was simultaneously withdrawn to obtain plasma for ir beta END. PTSD symptom clusters, as measured by the CAPS, were correlated with neuroendocrine data. Mean CSF ir beta END was significantly greater in patients with PTSD compared with normals and there was a negative correlation between the ir beta END and PTSD intrusive and avoidant symptoms of PTSD. No intergroup difference between plasma ir beta END was found, nor was there a significant correlation between CSF and plasma ir beta END. Immunoreactive beta-lipotropin (ir beta LPH) and pro-opiomelanocortin (irPOMC), both precursors of beta END, were much more plentiful in human CSF than was beta-endorphin itself, as has been previously reported. It remains to be determined whether the increased CNS opioid concentrations predate traumatic stress, thereby conferring a vulnerability to dissociative states and PTSD itself, or result from the trauma. The negative correlation between CSF ir beta END and avoidant and intrusive symptoms suggests that CNS hypersecretion of opioids might constitute an adaptive response to traumatic experience. Poor correlation between CSF and plasma ir beta END limits use of plasma measures to assess CNS opioid activity.

A comparison of the inflammatory potential of particulates derived from two composite materials

In order to develop total joint prostheses with moduli of elasticity close to bone while retaining excellent strength characteristics, composite materials are being developed. Composites consist of graphite fibers embedded in a polymer matrix. We studied the inflammatory potential of particulates derived from two composites with different matrix components, polysulfone (PFS) and polyetherketoneketone (PEKK), in the rat subcutaneous air pouch model. Neat components of the composites were studied separately in the air pouch. Particulates also were studied in culture using the macrophage cell line RAW 264.7, adherent synovial cells (ASC), and human polymorphonuclear neutrophils (PMNs). Particles derived from the PEKK-containing composite material consistently were less inflammatory than the PFS composite-derived particles, as measured by PMN infiltration, neutral metalloprotease activity, tumor necrosis factor (TNF) activity, and prostaglandin E2 (PGE2) accumulation. Results from the neat materials confirmed the findings in the composite-derived material. PEKK composite-derived material produced less TNF from macrophage cultures, but there were no significant differences noted in PGE2 production from ASC or in superoxide anion generation from PMNs. Particles from both PSF and PEKK produced minimal inflammatory responses in the rat subcutaneous air pouch. PEKK elicited a response virtually the same as the saline control and significantly less than that produced by particles of PSF.

Effect of a nonsteroidal antiinflammatory drug on synovial fluid in osteoarthritis

OBJECTIVE

The use of nonsteroidal antiinflammatory drug (NSAID) therapy in osteoarthritis (OA) is controversial because of suggestions that pure analgesics can be as effective as NSAID for pain relief. In addition, there is incomplete information whether antiinflammatory effects have any longterm benefit in OA. NSAID have been known to affect synovial fluid (SF) prostaglandins in rheumatoid arthritis. We describe the first examination of the effect of an NSAID, etodolac, on SF prostaglandins, cytokines, and cells in OA.

METHODS

Joint fluids were studied before and 2 weeks after initiation of therapy with etodolac 400 mg tid. Leukocyte counts, prostaglandin, interleukin 6, and tumor necrosis factor were measured.

RESULTS

Pretreatment features of SF did not predict clinical response. We found no change in the relatively low leukocyte counts. However, SF prostaglandin levels and interleukin 6 levels were significantly decreased and tumor necrosis factor alpha levels were increased after therapy with NSAID.

CONCLUSION

This NSAID had potentially important local effects that could be either beneficial or deleterious. Further studies on effects of this and other NSAID on a broader variety of SF and synovial cytokines may help predict longterm effects of NSAID on progression of OA.

Serum IgE levels in dairy calves: evaluation of parasite and pasture exposure as possible determinants of IgE response

Immunoglobulin E (IgE) has been regarded as an antibody isotype important in the host response to helminth infection and allergic conditions. Level of parasitic infection has been associated with serum total IgE level and the highest levels have been observed during the spring when environmental allergen levels are also high. Two groups of five parasite-native calves were maintained in a barn and one of the groups received an experimental gastrointestinal nematode infection. One group of five parasite-native calves was placed on clean pasture and another group of five was placed on a nematode-contaminated pasture. The contaminated pasture group acquired an acute gastrointestinal nematode infection, compared with a relatively low infection in the experimentally infected group. The only difference between the groups was a significant change (increase) in IgE level in calves on contaminated pasture, compared with the other three groups. This suggested that the infection acquired on pasture and not the experimental infection or environmental allergens encountered while grazing or in the barn stimulated an IgE response.

In vivo inflammatory response to silicone elastomer particulate debris

Silicone elastomer particles (Silastic silicone elastomer, Dow Corning, Midland, MI), polymethylmethacrylate particles, and monosodium urate particles smaller than 10 microns were injected into a rat subcutaneous air pouch lined with synovial membrane-like cells. Inflammatory exudate from the air pouch was retrieved at 6 hours, 24 hours, 48 hours, and 72 hours after injection. White blood cell count, tumor necrosis factor, and prostaglandin E2 were measured in the exudate. White blood cell and tumor necrosis factor levels in the exudate were the highest for the silicone group at 6 and 24 hours. Prostaglandin E2 was also significantly higher in the silicone group at 24 hours. We conclude that the acute inflammation is particle-type specific and that Silicone elastomer particles are acutely inflammatory.

Clinical assessment of the 1987 American College of Rheumatology criteria for rheumatoid arthritis

The 1987 American College of Rheumatology (ACR) criteria for the classification of rheumatoid arthritis (RA) were clinically assessed. These criteria do not include findings of synovial fluid (SF) analysis and require no exclusion criteria. We have studied sequential patients with arthritis seen in four rheumatology centers in the Philadelphia area. Classifications by the ACR criteria were compared with our clinical diagnoses. Two hundred ninety eight patients were evaluated, 113 with RA and 185 with other diagnoses. Classifications as RA by the ACR criteria corresponded to our clinical diagnosis in 95% of the cases, corroborating the high sensitivity previously reported. However, we found a lower specificity (73%) than that reported (89%). False positive classifications as RA were found in 71% of patients with psoriatic arthritis, 48% of patients with SLE, and 31% of patients with gout. The specificity could be improved to 89% by excluding disorders with obvious distinguishing extraarticular features such as psoriasis or by SF findings of monosodium urate crystals. Awareness of these possible sources of confusion will further increase the teaching and epidemiologic value of these useful simplified criteria.

An unusual coccidian parasite causing pneumonia in a northern cardinal (Cardinalis cardinalis)

In June 1993 an unusual coccidian parasite was identified in lung tissue from a northern cardinal (Cardinalis cardinalis), collected near Tucson, Arizona (USA), which died in respiratory distress. Histologically, there was evidence of severe, generalized interstitial pneumonia, associated with the parasite. Both asexual and sexual stages were seen. Schizonts, gamonts, and sporulated oocysts were seen in lung tissue. The parasite most closely resembled coccidia of the genus Lankesterella. This is the first report of such a coccidian parasite in the alveolar tissue of a cardinal.

A double-blind, randomized, placebo-controlled, multi-center study of brofaromine in the treatment of post-traumatic stress disorder

A large multi-center, double-blind, parallel trial to assess the efficacy of brofaromine in the treatment of post traumatic stress disorder (PTSD) failed to show a significant difference between the brofaromine and placebo treatment groups. The placebo response rate in this study was higher than that in previously published double-blind, placebo-controlled studies of PTSD.

Experimental oral inoculations in birds to evaluate potential definitive hosts of Neospora caninum

Experimental oral inoculations to evaluate potential definitive hosts of Neospora caninum were conducted by feeding infected rodent tissues to 9 carnivorous birds of 4 species. Birds included 2 red-tailed hawks (Buteo jamaicensis), 2 turkey vultures (Cathartes aura), 2 barn owls (Tyto alba), and 3 American crows (Corvus brachyrhynchus). The rodents (mice or rats) had been inoculated with 100,000 culture-derived tachyzoites of N. caninum 1-6 mo before feeding to the birds. Fecal samples were collected from each bird daily for 1 mo after feeding rodents and examined for oocysts by fecal flotation. In addition, processed aliquots from all avian fecal samples were fed to BALB/c mice. Five weeks after feeding, mice were bled and sera were tested for antibodies against N. caninum. One to two months later, mice were killed and brain tissue was examined microscopically for protozoal cysts. While occasional oocysts were found in avian fecal samples, these were likely not N. caninum because they were not infective to BALB/c mice. It was concluded that the bird species tested are not likely to be definitive hosts of N. caninum.

Squamous cell carcinoma growth in irradiated tissue: a murine model for quantitative assessment of treatment

Locoregional recurrent and distant metastases from squamous cell carcinomas, despite multimodality therapy, remain troublesome clinical realities. Discrepancies in success rates of various surgery and radiation treatment regimens dealing with these problems are confusing to the clinician attempting to recommend the most beneficial treatments. There is a need for an experimental model to assess therapeutic effectiveness quantitatively from which guidelines for developing clinical trials may be suggested. In this study, we provide such a model. We injected DBA-2 mice with defined numbers of KLN-205 squamous carcinoma cells to obtain baseline growth characteristics; 216 animals had no previous irradiation. The remaining 131 received 30 Gy irradiation to the right leg 50 days before injection of the tumor cells. Tumor incidence, growth and number, and location of tumor metastasis were determined in both previously irradiated and nonirradiated groups. The data demonstrate a growth-retardant effect on tumor groups by the previous irradiation (tumor bed effect). The data also show that the incidence of hematogenously spread metastases was more frequent in mice in which tumors developed in previously irradiated tissue than in mice with tumors in nonirradiated tissue.

Swine immunity to selected parasites

Swine parasitism exerts a significant economic impact worldwide. In the United States, the greatest losses are due directly or indirectly to the costs of zoonotic parasitisms. Three of the six most common foodborne parasitic diseases of humans in the United States are associated with pork consumption. These include toxoplasmosis, taeniasis or cysticercosis (caused by the pork tapeworm Taenia solium), and trichinellosis. Toxoplasmosis is of particular concern because of the fulminating disease that occurs in immunocompromised people. Generalizations and extrapolations of information derived from rodent and human studies, to swine parasitisms, are complicated by immunological differences between the hosts, and by the diverse biological characteristics of internal and external parasites studied. Swine studies thus far reported have demonstrated that protective immunity to helminth infection involves both cellular and humoral mechanisms, with antibodies and antibody-mediated responses playing important roles in preventing establishment of newly acquired larvae. Protection against protozoan parasites is primarily by cell-mediated strategies, whereas protective immunity to arthropod infestation is primarily through humoral mechanisms, principally those associated with type 1 hypersensitivity.

Persistence of immunity to toxoplasmosis in pigs vaccinated with a nonpersistent strain of Toxoplasma gondii

Persistence of the vaccine RH strain of Toxoplasma gondii was studied by bioassay and histologically in 14 pigs. Pigs were euthanatized 2, 4, 7, 8, 14, 15, 21, 29, 36, 42, 52, 57, and 76 days after IM inoculation with 100,000 T gondii tachyzoites. Viable T gondii tachyzoites derived from the RH strain were isolated by bioassay in mice inoculated with tissues of pigs euthanatized up to 14 days after vaccination. Except for fever, pigs vaccinated IM with the RH strain remained clinically normal. Two other pigs inoculated IV with 100,000 T gondii tachyzoites of the RH strain became ill, and 1 pig was comatose by 4 days after inoculation. These findings indicate that route of inoculation may influence the response of pigs to T gondii. To evaluate protective immunity in pigs vaccinated with the RH strain, 16 age-matched pigs were allotted to 4 groups (A-D) of 4 pigs each. Eight pigs (groups A and C) were vaccinated IM with 100,000 RH strain tachyzoites and 8 pigs (groups B and D) were nonvaccinated controls. Pigs of groups A and C were challenge-inoculated orally with a lethal dose of T gondii oocysts (100,000 oocysts) 81 days after vaccination, pigs of groups B and D were inoculated similarly 220 days after vaccination. The concentration of T gondii at 3 days after challenge inoculation of pigs vaccinated 81 days earlier was reduced 100,000-fold in mesenteric lymph nodes, compared with that in a nonvaccinated pig euthanatized at 3 days after challenge inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the inflammatory response to particulate polymethylmethacrylate debris with and without barium sulfate

Particulate polymethylmethacrylate debris has been implicated in the inflammatory response observed surrounding loosened cemented implants. The rat subcutaneous pouch model and the Howie implant model (used to study bone resorption) were used to quantify the response to mechanically produced endotoxin-free polymethylmethacrylate debris with and without 10% (wt/vol) BaSO4. In the rat subcutaneous pouch model, the inflammatory response to polymethylmethacrylate particles containing BaSO4 was greater than the response to plain polymethylmethacrylate particles of similar size. Increased inflammation was measured by leukocyte counts and levels of prostaglandin E2, tumor necrosis factor, and neutral metalloprotease. In addition, particulate polymethylmethacrylate with BaSO4 caused significantly greater bone resorption in the Howie model than did particulate plain polymethylmethacrylate. In in vitro studies, particulate polymethylmethacrylate with BaSO4 stimulated more prostaglandin E2, neutral metalloprotease, and tumor necrosis factor from human monocytes in culture and stimulated greater proliferation of synovial cells than did particulate plain polymethylmethacrylate. The presence of BaSO4 appears to significantly intensify the inflammatory response to polymethylmethacrylate debris.

Alpha-adrenergic and muscarinic cholinergic inhibition of ACh release in guinea pig trachea: role of neuronal K+ channels

Our goals were to establish that an alpha 2-adrenergic agonist (clonidine) inhibits ACh release from airway nerve endings and to test effects of iberiotoxin (IBTX), an inhibitor of fast-conductance, Ca(2+)-activated K+ channels on alpha 2-adrenergic and muscarinic attenuation of ACh release. Guinea pig tracheas were mounted between electrodes in buffer containing indomethacin and neostigmine, and high-performance liquid chromatography with electrochemical detection was used to measure ACh release during electrical field stimulation. Clonidine inhibited ACh release in a concentration-dependent fashion [maximum reduction: 48 +/- 3%; 50% inhibitory constant (IC50): 0.1 microM], and idazoxan, alpha 2-adrenergic antagonist, reversed the effect. However, IBTX failed to alter clonidine-induced attenuation of ACh release. In contrast, IBTX did cause an increase in tracheal tension. In addition, IBTX failed to reverse any of the potent autoinhibitory effects of endogenous ACh. Our results confirm the presence of inhibitory alpha 2-adrenergic receptors. However, activation of IBTX-sensitive K+ channels does not appear necessary for either alpha 2-adrenergic or muscarinic cholinergic inhibition of ACh release.

In vivo inflammatory response to polymethylmethacrylate particulate debris: effect of size, morphology, and surface area

Particulate debris, including that from polymethylmethacrylate (PMMA) cement, is observed commonly in the membrane surrounding loose joint prostheses. Such debris is assumed to cause an inflammatory response and contributes to osteolysis and failure of the implant. A subcutaneous rat air-pouch model was used to assess quantitatively the in vivo effects of the size, morphology, and surface area of PMMA particles on the acute inflammatory response. PMMA particles were divided into three groups. In Group A, mechanical grinding of cured bone cement produced irregularly shaped particles; Group B included spherical particles of PMMA powder (Simplex P); and Group C consisted of commercially prepared spherical latex particles. All three groups had two size distributions: < 20 microns and 50-350 microns. For a given mass or dose, the small, irregularly shaped mechanically produced particles in Group A elicited a significantly greater inflammatory reaction than the large particles in Group A, as expressed by the release of tumor necrosis factor (TNF), neutral metalloprotease (NMP), and prostaglandin E2 (PGE2) and the white blood cell (WBC) count within a 24-hour period. Similar findings were seen in Group B. Particles in Group C were used to compare the effect of absolute numbers of large and small particles and surface area. Large (10-126 microns) spherical PMMA particles at a dose of 1.7 x 10(6) particles/ml caused a significantly higher inflammatory response, as measured by WBC count and production of NMP and PGE2, than small (1-10 microns) spheres at a dose of 4 x 10(6) particles/ml. However, the production of TNF in the rats was significantly increased with small particles (p < 0.05) at a concentration 4-fold less than that with the large particles (4 x 10(5) compared with 1.7 x 10(6) particles/ml). This finding may reflect a different cellular mechanism for the TNF component of the inflammatory response than is measured by WBC counts or by levels of PGE2 and NMP. As the calculated surface area of the PMMA particles increased, a threshold level was reached, at which point the inflammatory response increased dramatically. The size of particles has a role in the prolongation and intensity of the release of specific cytokines. The total surface area of the particles appeared to be an important factor in determining the inflammatory response, as measured by WBC count, PGE2, TNF, and NMP.

Abomasal lymphatic lymphocyte subpopulations in cattle infected with Ostertagia ostertagi and Cooperia sp

Abomasal lymphatic cannulation was performed on steers naturally or experimentally infected with Ostertagia ostertagi and Cooperia sp.. Abomasal lymphatic lymphocyte subpopulations were evaluated using antibodies specific for bovine mononuclear cell surface antigens, followed by flow cytometric analysis. When compared with the non-infected or experimentally infected steers, naturally infected steers with Type 1 or Type 2 ostertagiosis had increased percentages of B-lymphocytes. The percentages of B-lymphocytes were related to the numbers of O. ostertagi and Cooperia sp.. These findings are compatible with reports of worm-specific antibody synthesis in bovine nematodiases.

SDS-PAGE profiles of somatic proteins from third-stage infective larvae of Ostertagia ostertagi and Cooperia oncophora

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of somatic proteins from third-stage infective larvae of Ostertagia ostertagi and Cooperia oncophora were evaluated using laser densitometry. Several protein bands were present from both parasite preparations. A few bands from each parasite appeared to be unique. Purification of these proteins for use in serologic monitoring of cattle naturally infected with O. ostertagi and C. oncophora should allow circumvention of cross-reactivity between the two genera, which has been reported by others.

Competency assessment in the elderly

Although brain changes and functional capacity impairment occur in both normal and abnormal aging, it is the extent of change which determines competency status. Dementia to some degree afflicts 10 percent to 15 percent of 30 million Americans over age 65. History, age-normed neuropsychological testing, and laboratory investigations are essential to competency assessment since physical and personality dysfunctions may masquerade as dementia. Since competency decisions profoundly impact the lives of the elderly, our fastest growing segment of national population, psychiatrists, psychologists, family physicians, and lawyers will become increasingly involved in competency issues.

Abomasal interstitial fluid-to-blood concentration gradient of pepsinogen in calves with type-1 and type-2 ostertagiosis

Pepsinogen and protein concentrations were determined in blood samples, collected from the left gastroepiploic artery and vein, and in abomasal lymph from 15 steers naturally infected with Ostertagia ostertagi and 4 uninfected steers. In steers with type-1 ostertagiosis, the concentration gradient between the mucosal interstitium and the blood alone could account for higher than normal serum pepsinogen concentrations. High interstitial pepsinogen concentrations may have resulted from increased epithelial permeability or increased pepsinogen production and secretion. However, in steers with type-2 ostertagiosis, the concentration gradient could not entirely account for the high serum pepsinogen concentrations, suggesting that capillary permeability or surface area may have been altered. Lymphatic uptake contributed pepsinogen to the blood in all infected steers.