Differential activities of secreted lymphotoxin-alpha3 and membrane lymphotoxin-alpha1beta2 in lymphotoxin-induced inflammation: critical role of TNF receptor 1 signaling

Lymphotoxin (LT, LT alpha, TNF beta) is a member of the immediate TNF family that also includes TNF-alpha and lymphotoxin-beta (LT beta). LT is produced by activated lymphocytes and functions as either a secreted homotrimer or a membrane-associated heterotrimer that includes the transmembrane protein LT beta. Secreted LT alpha3 can bind to two cell surface receptors, TNFR1 and TNFR2, while the membrane-bound heterotrimer LT alpha1beta2 has been shown to interact with a distinct receptor, LT betaR. LT alpha induces inflammation at the sites of expression of a rat insulin promoter-driven lymphotoxin (RIPLT) transgene in the pancreas and kidney. To determine the role of the various ligands and their receptors in LT-induced inflammation, mice deficient in either TNFR1, TNFR2, or LT beta were crossed to RIPLT-transgenic mice. Our results indicate that LT alpha-induced inflammation is dependent on the interaction of LT alpha3 with TNFR1, and there is no obvious role for TNFR2, since in its absence, LT alpha-induced inflammation is quantitatively and qualitatively similar to that seen in the wild type. However, the absence of LT beta results in accentuated infiltration of the kidney with an increase in the proportion of memory cells in the infiltrate. These data show a crucial role for the secreted LT alpha3 signaling via TNFR1 in LT alpha-induced inflammation, and a separate and distinct role for the membrane LT alpha1beta2 form in this inflammatory process.     

Stability of mycophenolate mofetil in an extemporaneously compounded oral liquid

The stability of mycophenolate mofetil in an extemporaneously prepared 100-mg/mL oral liquid was studied. The contents of 80 250-mg capsules of mycophenolate mofetil were combined with sterile water for irrigation and cherry-flavored syrup to produce 200 mL of suspension. Six 1-mL samples were analyzed immediately, and the rest of the suspension was poured into 12 2-oz amber polyethylene terephthalate [corrected] G(PETG) bottles; six bottles were stored at 23-25 degrees C and six at 2-8 degrees C. Samples were removed on days 14, 21, 28, 35, 49, 63, 92, and 121 for analysis by high-performance liquid chromatography; pH was measured initially and at each sampling time. The pH of the suspension was initially 6.1 and remained unchanged throughout the study. The suspension retained more than 90% of its initial drug concentration for 121 days at 23-25 and 2-8 degrees C. There was no detectable change in color or odor and no visible microbial growth in any sample. Mycophenolate mofetil in a 100-mg/mL oral liquid prepared with cherry-flavored vehicle and stored in amber PETG bottles was stable for 121 days at 23-25 and 2-8 degrees C.     

Glucocorticoid receptor polymorphism, skin vasoconstriction, and other metabolic intermediate phenotypes in normal human subjects

Genetic variation of the glucocorticoid receptor (GR) locus is associated with differences in blood pressure. To define the intermediate phenotypes associated with this variation, we investigated the biochemical and clinical significance of a BclI restriction fragment length polymorphism of the GR locus in 64 normal male volunteers. Blood samples were genotyped as either AA (homozygous large allele; n = 6), Aa (heterozygous; n = 51), or aa (homozygous small allele, n = 7). Four primary glucocorticoid variables were measured including GR binding characteristics and glucocorticoid-sensitive lysozyme release of leukocytes in vitro and the blanching response of forearm skin to budesonide. A large number of secondary variables (urinary and plasma steroid measurements, blood pressure and indices of body fat metabolism, and routine biochemical and hematological measurements) were also considered. In vivo sensitivity to budesonide was greater in AA than aa individuals (mean +/- SE EC50 values: 13 +/- 5 and 42 +/- 10 ng; P < 0.01). In contrast, leukocytes of AA subjects tended to have lower affinity and reduced sensitivity for dexamethasone, although these effects were not statistically significant. Based on urinary steroid measurements, 11 beta-hydroxysteroid dehydrogenase activity [ratio of tetrahydrocortisol (THF) to tetrahydrocortisone (THE) metabolites] was not affected by genotype. The relative activities of 5 alpha- and 5 beta-reductase activity (allo-THF/THF + THE) appeared lower in AA than aa subjects (0.22 +/- 0.04 cf. 0.33 +/- 0.06; P < 0.005) but were not judged to be significantly different when corrected for multiple comparisons. Single and multivariate analyses were carried out to determine which variables influence GR binding characteristics and glucocorticoid responsiveness and to see whether cardiovascular risk factors (blood pressure and body fat) were influenced by glucocorticoid-dependent functions. Only 15-20% of the variations in the dissociation constant (Kd) and maximum binding capacity (Bmax) were influenced by other variables; plasma cholesterol was the most important for affinity and plasma sodium concentration for binding capacity. Multivariate analysis showed that several factors including GR genotype and urinary cortisol account for 10% of the variation of in vivo responses to glucocorticoid hormones; plasma calcium concentration was the only variable that contributed to in vitro sensitivity of leukocytes to dexamethasone. Glucocorticoid-dependent responses were of negligible importance in determining blood pressure or percentage body fat within the narrow physiological ranges of the present study. We conclude that GR genotype affects steroid sensitivity in a tissue-specific manner because of altered GR function or possibly because of linkage to a locus that controls hormone access to the receptor by influencing steroid metabolism.     

Comparative safety of tetracycline, minocycline, and doxycycline

BACKGROUND: Because minocycline can cause serious adverse events including hypersensitivity syndrome reaction (HSR), serum sicknesslike reaction (SSLR), and drug-induced lupus, a follow-up study based on a retrospective review of our Drug Safety Clinic and the Health Protection Branch databases and a literature review was conducted to determine if similar rare events are associated with tetracycline and doxycycline. Cases of isolated single organ dysfunction (SOD) attributable to the use of these antibiotics also were identified. OBSERVATIONS: Nineteen cases of HSR due to minocycline, 2 due to tetracycline, and 1 due to doxycycline were identified. Eleven cases of SSLR due to minocycline, 3 due to tetracycline, and 2 due to doxycycline were identified. All 33 cases of drug-induced lupus were attributable to minocycline. Forty cases of SOD from minocycline, 37 cases from tetracycline, and 6 from doxycycline were detected. Hypersensitivity syndrome reaction, SSLR, and SOD occur on average within 4 weeks of therapy, whereas minocycline-induced lupus occurs on average 2 years after the initiation of therapy. CONCLUSIONS: Early serious events occurring during the course of tetracycline antibiotic treatment include HSR, SSLR, and SOD. Drug-induced lupus, which occurs late in the course of therapy, is reported only with minocycline. We theorize that minocycline metabolism may account for the increased frequency of serious adverse events with this drug.     

Drug interactions in human neuropathic pain pharmacotherapy

The effects of 0.3 mg/kg methylphenidate (MPH) and expectancy regarding medication on the performance and task persistence of 60 boys with attention deficit hyperactivity disorder (ADHD) were investigated. In a balanced-placebo design, boys in 4 groups (received placebo/drug crossed with told placebo/drug) completed the task in success and failure conditions. Medication improved participants' task persistence following failure. Participants' task performance was not affected by whether they thought they had received medication or placebo. Children made internal attributions for success and made external attributions for failure, regardless of medication or expectancy. These findings confirm previous reports that it is the pharmacological activity of MPH that affects ADHD children's self-evaluations and persistence. The results contradict anecdotal reports that MPH causes dysfunctional attributions and confirm previous studies showing that medication does not produce adverse effects on the causal attributions of children with ADHD.     

Intranigral iron infusion in the rat. Acute elevations in nigral lipid peroxidation and striatal dopaminergic markers with ensuing nigral degeneration

Iron is known to induce lipid peroxidation and recent evidence indicates that both iron and lipid peroxidation are elevated in the substantia nigra in Parkinson's disease (PD). To test whether excess intranigral iron induces lipid peroxidation, we infused an iron citrate solution (0.63 nmol in 0.25 microL) into the rat substantia nigra and measured nigral thiobarbituric acid reactive products at 1-h, 1-d, 1-wk, and 1-mo postinfusion. In a separate group of iron-infused animals, histologic analysis within the substantia nigra through 1-mo postinfusion was accomplished by thionine- and iron-staining, with concurrent assessment of striatal neurochemical markers. Concentrations of nigral thiobarbituric acid reactive products were significantly elevated at 1 h and 1 d in iron-infused animals compared to vehicle-infused and unoperated animals, with a return to control values by 1 wk. Similarly, striatal dopamine turnover was acutely elevated, suggesting damage to dopaminergic neurons, which was confirmed histologically. Although iron-staining within the iron diffusionary area was increased through the postinfusion month, there was an apparent progression of the cellular character of staining from predominantly neuronal to reactive glial and finally to oligodendroglial by 1 mo postinfusion. This progression of cellular iron-staining may indicate a shifting of infused iron to a more bound unreactive form, thus explaining only an acute elevation in lipid peroxidation through 1 d following intranigral iron infusion. The data indicate that damage to nigral neurons induced by iron infusion is transciently associated with a marker of oxidative damage and supports the possibility that iron-induced oxidative stress contributes to the pathogenesis of PD.     

Urinary assays for desmosine and hydroxylysylpyridinoline in the detection of cirrhosis

BACKGROUND/AIMS: Non-invasive markers of liver fibrosis have great potential for both the diagnosis and therapy of liver disease and cirrhosis. The aim of this study was to evaluate the potential of urinary amino acids desmosine (DES) and isodesmosine (IDES) derived from the breakdown of elastin and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) derived from fibrillar collagen in diagnosing chronic liver disease. METHODS: We studied 48 patients with chronic liver disease who had varying degrees of liver fibrosis, graded 0-6 using a modified Knodell score, and 20 control subjects without liver disease. Urinary DES (microg/g creatinine) and HP (nmol/mmol creatinine) were measured by an isotope dilution, high performance liquid chromatography method. For liver disease patients, aminoterminal propeptide of type III procollagen (PIIINP) and alanine aminotransferase were determined. The urine and serum markers were correlated to degree of fibrosis and inflammation on liver biopsies. Differences between groups were analyzed by ANOVA and multiple linear regression was applied to determine independence of variables. Sensitivity, specificity and receiver operating curves were derived for each marker. RESULTS: In the 17 patients with liver fibrosis score of 5-6, mean urinary DES, IDES, HP and LP were all significantly greater than in the control group (p<0.05). Urinary DES and IDES correlated best with fibrosis score, r=0.61 for both markers. The correlation coefficient between serum PIIINP and fibrosis score was 0.47. Urinary DES and HP each had an overall diagnostic accuracy of 77% for fibrosis. Combining markers improved accuracy to over 80%. No correlation was seen between the urinary markers and inflammation scores. CONCLUSIONS: Urinary DES and HP are potentially useful clinical markers for liver fibrosis, especially when used in combination or in association with PIIINP.     

Sj?gren''s syndrome with acute renal failure

STUDY OBJECTIVE: "Suicide by cop" is a term used by law enforcement officers to describe an incident in which a suicidal individual intentionally engages in life-threatening and criminal behavior with a lethal weapon or what appears to be a lethal weapon toward law enforcement officers or civilians to specifically provoke officers to shoot the suicidal individual in self-defense or to protect civilians. The objective of this study was to investigate the phenomenon that some individuals attempt or commit suicide by intentionally provoking law enforcement officers to shoot them. METHODS: We reviewed all files of officer-involved shootings investigated by the Los Angeles County Sheriff's Department from 1987 to 1997. Cases met the following criteria: (1) evidence of the individual's suicidal intent, (2) evidence they specifically wanted officers to shoot them, (3) evidence they possessed a lethal weapon or what appeared to be a lethal weapon, and (4) evidence they intentionally escalated the encounter and provoked officers to shoot them. RESULTS: Suicide by cop accounted for 11% (n=46) of all officer-involved shootings and 13% of all officer-involved justifiable homicides. Ages of suicidal individuals ranged from 18 to 54 years; 98% were male. Forty-eight percent of weapons possessed by suicidal individuals were firearms, 17% replica firearms. The median time from arrival of officers at the scene to the time of the shooting was 15 minutes with 70% of shootings occurring within 30 minutes of arrival of officers. Thirty-nine percent of cases involved domestic violence. Fifty-four percent of suicidal individuals sustained fatal gunshot wounds. All deaths were classified by the coroner as homicides, as opposed to suicides. CONCLUSION: Suicide by cop is an actual form of suicide. The most appropriate term for this phenomenon is law enforcement-forced-assisted suicide. Law enforcement agencies may be able to develop strategies for early recognition and handling of law enforcement-forced-assisted suicide (suicide by cop). Health care providers involved in the evaluation of potentially suicidal individuals and in the resuscitation of officer-involved shootings should be aware of law enforcement-forced-assisted suicide as a form of suicide.     

Teratocarcinosarcoma of the nasal cavity and ethmoid

Sialyl-Tn antigen (STn) expression was studied immunohistochemically in 211 primary advanced gastric carcinomas. The overall rate of positive STn staining was 17% (35/211), and positive STn staining was found not to be correlated with tumor size, depth of invasion, lymph node metastasis, liver metastasis, or peritoneal metastasis. However, patients with tumors that were immunoreactive for STn demonstrated significantly lower survival (P < 0.05). Multivariate analysis revealed that STn staining was an independent prognostic factor. From these findings we conclude that careful followup and intense postoperative therapy are required for patients with advanced gastric cancer who have positive immunoreactivity for STn.