Posttraumatic stress disorder and drug disorders: testing causal pathways

BACKGROUND: Although there is a high degree of comorbidity between posttraumatic stress disorder (PTSD) and drug use disorders, little is known about causal relationships between PTSD, exposure to traumatic events, and drug use disorders. METHODS: In a longitudinal study in southeast Michigan, 1007 adults aged 21 to 30 years were initially assessed in 1989 and were followed up 3 and 5 years later, in 1992 and 1994. Psychiatric disorders according to DSM-III-R criteria were measured by the National Institute of Mental Health Diagnostic Interview Schedule. To take into account temporal sequencing, the associations between PTSD, traumatic events, and drug use disorders were analyzed by using Cox proportional hazards models with time-dependent covariates. RESULTS: Posttraumatic stress disorder signaled an increased risk of drug abuse or dependence (hazards ratio, 4.5; 95% confidence interval, 2.6-7.6, adjusted for sex), whereas exposure to traumatic events in the absence of PTSD did not increase the risk of drug abuse or dependence. The risk for abuse or dependence was the highest for prescribed psychoactive drugs (hazards ratio, 13.0; 95% confidence interval, 5.3-32.0). There was no evidence that preexisting drug abuse or dependence increased the risk of subsequent exposure to traumatic events or the risk of PTSD after traumatic exposure. CONCLUSION: The results suggest that drug abuse or dependence in persons with PTSD might be the inadvertent result of efforts to medicate symptoms, although the possibility of shared vulnerability to PTSD and drug use disorders cannot be ruled out.     

Evidence of participation of McrB(S) in McrBC restriction in Escherichia coli K-12

The McrBC restriction system has the ability to restrict DNA containing 5-hydroxymethylcytosine, N4-methylcytosine, and 5-methylcytosine at specific sequences. The mcrB gene produces two gene products. The complete mcrB open reading frame produces a 51-kDa protein (McrB(L)) and a 33-kDa protein (McrB(S)). The smaller McrB polypeptide is produced from an in-frame, internal translational start site in the mcrB gene. The McrB(S) sequence is identical to that of McrB(L) except that it lacks 161 amino acids present at the N-terminal end of the latter protein. It has been suggested that McrB(L) is the DNA binding restriction subunit. The function of McrB(S) is unknown, although there has been speculation that it plays some role in the modulation of McrBC restriction. Studies of the function of McrB(S) have been challenging since it is produced in frame with McrB(L). In this study, we tested the effects of underproduction (via antisense RNA) and overproduction (via gene dosage) of mcrBC gene products on restriction levels of the mcrBC+ strain JM107. Among the parameters monitored was the induction of SOS responses, which indicate of DNA damage. Evidence from this study suggests that McrB(S) is necessary for stabilization of the McrBC restriction complex in vivo.     

Impact of multiple antenatal doses of betamethasone on growth and development of mice offspring

OBJECTIVE: Our purpose was to determine in a randomized, placebo-controlled manner whether multiple antenatal doses of betamethasone affect long-term growth and development of exposed mouse offspring. STUDY DESIGN: Sixty pregnant CD-1 mice received either two, four, or eight antepartum doses of 0.1 mg betamethasone or placebo. Perinatal outcomes, growth, and development of the offspring were compared in a blinded manner. Variables were compared by analysis of variance or chi 2 testing. RESULTS: Betamethasone-exposed subjects gained less weight during pregnancy and were delivered of fewer live pups, with fewer male survivors and lower birth weights. These trends were dose related. Growth measurements were similar after the neonatal period. No differences in functional development and physical maturation in the offspring were noted. The reproductive capability, perinatal outcomes, and growth and development of the second-generation offspring were unaffected by betamethasone exposure. CONCLUSION: Multiple antenatal dosings of betamethasone, reaching toxic levels, did not have an impact on the long-term growth and development of the surviving mouse offspring.     

Lansoprazole. An update of its pharmacological properties and clinical efficacy in the management of acid-related disorders

Lansoprazole is a proton pump inhibitor that reduces gastric acid secretion. It has proved effective in combination regimens for the eradication of Helicobacter pylori and as monotherapy to heal and relieve symptoms of gastric or duodenal ulcers and gastro-oesophageal reflux. After initial healing, it may be used to prevent recurrence of oesophageal erosions or peptic ulcers in patients in whom H. pylori is not the major cause of ulceration and to reduce basal acid output in patients with Zollinger-Ellison syndrome. Usual dosages are 15 to 60 mg/day, although dosages of < or = 180 mg/day have been used in patients with hypersecretory states. In patients with duodenal or gastric ulcer, short term lansoprazole monotherapy was similar to omeprazole and superior to histamine H2 receptor antagonists in achieving healing rates > 90%. Lansoprazole was as effective a component of H. pylori eradication regimens as omeprazole, tripotassium dicitrato bismuthate (colloidal bismuth subcitrate) or ranitidine. Lansoprazole was superior to ranitidine in symptom relief and healing of gastro-oesophageal reflux disease and tended to relieve symptoms more rapidly than omeprazole, although initial healing was similar. As maintenance treatment, lansoprazole was similar to omeprazole and superior to ranitidine in relieving symptoms and preventing relapse. Lansoprazole was also superior to ranitidine in healing and relieving symptoms of oesophageal erosions associated with Barrett's oesophagus; healing was maintained for a mean of 2.9 years in > or = 70% of patients. Lansoprazole was also superior to ranitidine in prophylaxis of redilatation of oesophageal strictures. After > or = 4 years of use in patients with Zollinger-Ellison syndrome, lansoprazole 60 to 180 mg/day effectively controlled basal acid output. Dosages may be reduced in some patients once healing and symptom relief has been achieved. Preliminary studies of lansoprazole in patients at risk of aspiration pneumonia or stress ulcers show promise. Although studies show lansoprazole is potentially effective in treating gastrointestinal bleeding, future studies should assess patients' H. pylori status. Lansoprazole has been well tolerated in clinical trials, with headache, diarrhoea, dizziness and nausea appearing to be the most common adverse effects. Tolerability of lansoprazole does not deteriorate with age and the drug is well tolerated in long term use (< or = 4 years) in patients with Zollinger-Ellison syndrome or reflux disease. Thus, lansoprazole is an important alternative to omeprazole and H2 receptor antagonists in acid-related disorders. In addition to its efficacy in healing or maintenance treatment, it may provide more effective symptom relief than other comparator agents.     

Defects at center P underlie diabetes-associated mitochondrial dysfunction

Detailed respiration studies on isolated liver mitochondria from streptozotocin-induced diabetic Sprague-Dawley rats revealed a disease-associated decrease in the ADP/O ratio, a marker for mitochondrial ability to couple the consumption of oxygen to the phosphorylation of ADP. This decrease was observed following induction of respiration with glutamate/malate, succinate, or duroquinol, which enter the electron transport chain selectively at complexes I (NADH dehydrogenase), II (succinate dehydrogenase), or III (cytochrome bc1 complex), respectively. These data, coupled with studies using respiratory inhibitors (most importantly antimycin A and myxothiazol), localize at least a portion of this defect to a single site within the electron transport chain (center P in the Q-cycle portion of complex III). These results suggest that liver mitochondria from diabetic animals may generate increased levels of reactive oxygen species at the portion of the electron transport chain already established as the major site of mitochondrial free radical generation. The reduction in the ADP/O ratio occurred in mitochondria that do not have overt defects in the respiratory control ratio or in State 3 and State 4 respiration. The data in this paper suggest that defects in center P of the electron transport chain likely increase mitochondrial exposure to oxidants in the diabetic. This data may partially explain the evidence of altered exposure and/or response to reactive species in mitochondria from diabetics. This work thus provides further clues to the interaction between oxidative stress and diabetes-associated mitochondrial dysfunction.     

Dietary modulation of avian coccidiosis

During the past several years, our laboratory has been investigating the anticoccidial activities of various natural products that have potential use as dietary supplements for coccidiosis control. Sources of fats containing high concentrations of n-3 fatty acids such as menhaden oil and flaxseed oil and flaxseed, when added to starter rations and fed to chicks from one day of age, effectively reduce lesions caused by the caecal parasite Eimeria tenella, but not lesions caused by Eimeria maxima. Our results are consistent with reports of effects of diets high in n-3 fatty acids on other protozoan parasites which suggest that the state of oxidative stress induced by these diets in the cells of both host and parasites is responsible for their parasitic actions. Artemisinin, a naturally occurring (Artemisia annua) endoperoxide and effective antimalarial significantly lowers lesions from E. tenella when given at low levels as a feed additive. The mechanism of its action is also considered to involve induction of oxidative stress. Diets supplemented with 8 p.p.m. gamma-tocopherol (abundant in flaxseeds) or with 1% of the spice tumeric, reduce mid-small intestinal lesion scores and improve weight gains during E. maxima infections. These compounds may exert their anticoccidial activity because they are effective antioxidants. Betaine, a choline analogue found in high concentrations in sugar beets, improves nutrient utilisation by animals under stress. When provided as a dietary supplement at a level of 0.15% it has enhanced the anticoccidial activity of the ionophore, salinomycin. Betaine may act as an osmoprotectant whereby it improves the integrity and function of the infected intestinal mucosa. In in vivo studies, betaine plus salinomycin significantly inhibit invasion of both E. tenella and E. acervulina. However, subsequent development of E. acervulina is inhibited more effectively with this combination treatment than development of E. tenella.     

Psoriasiform onychopachydermoperiostitis of the large toes: the OP3GO syndrome

OBJECTIVE: To describe our experience with primary appendiceal tumours. DESIGN: Retrospective study. SETTING: University hospital, Israel. SUBJECTS: 2520 patients who had appendectomies during the 14 years, January 1982-December 1996. RESULTS: 22 patients 5 male and 17 female, mean age 56.2 years, had primary neoplasms; 14 were carcinoid tumours and villous adenomas and were treated by appendicectomy only. Adenocarcinoma was diagnosed in 8 patients (0.3%), 5 after appendicectomy (0.2%) which is twice the reported incidence. They were all treated by right hemicolectomy. Seven of the patients were classified as Dukes' B and one as Dukes' C. All patients were alive and disease-free after a mean follow-up period of 57.4 months. CONCLUSION: Right hemicolectomy is the treatment of choice for adenocarcinoma of the appendix.     

Neuroendocrine differentiation is an independent prognostic factor in chemotherapy-treated nonsmall cell lung carcinoma

BACKGROUND: Neuroendocrine differentiation can be identified in 10-30% of patients with nonsmall cell lung carcinoma (NSCLC) by immunohistochemical or electron microscopic techniques. However, its clinical significance is not well established. METHODS: Tumors from 107 patients with Stage IIIA, IIIB, and IV NSCLC treated with cisplatin/etoposide with or without hydrazine in the North Central Cancer Treatment Group and Mayo Clinic protocols were analyzed immunohistochemically with antibodies to chromogranin A (CGA), Leu 7 (CD 57), and synaptophysin (SY). These results were compared with clinical outcomes. RESULTS: Keratin AE1/AE3, used as a control, was positive in 99.1% of cases; 34.6% had positive staining for at least 1 neuroendocrine marker, and 11.3% had positive staining for 2 or more markers. CGA was positive in 4.7%, Leu 7 in 18.7%, and SY in 24.3% of cases. A significant increase in survival was seen in patients with tumors expressing any one neuroendocrine marker or any combination of neuroendocrine markers (P < or = 0.01). There was no correlation between the presence of neuroendocrine differentiation and either response to chemotherapy or time to disease progression (P > 0.3), nor was there any correlation between chemotherapy response, time to progression, or survival with staining intensity or percent of cells positive per case. CONCLUSIONS: Neuroendocrine differentiation may be of prognostic significance in patients with advanced stage NSCLC treated with chemotherapy.