Metal Content Profiles in Mushrooms Collected in Primary Forests of Latin America

Ecotoxicology and environmental safety concerns suggested estimation of the content of 14 metals—some of them highly toxic, such as cadmium, mercury, and lead—in 26 mushrooms species (Basidiomycetes and Ascomycetes). The fungi—members of different genera—were collected during two periods, 1967–1969 and 1978–1981, in primary forests of Latin America (mainly French Guyana and a few samples from Colombia and Costa Rica), these areas are non- or slightly inhabited, therefore, industrial pollution has to be considered as totally nonexistent. Heavy metals, selectively concentrated in specific living organisms, should be regarded as toxin-like substances, taking into account the bioaccumulation sites (mushrooms) and the noxious activity toward various organs of mammals (i.e., central nervous system, kidneys, liver, etc.). The levels and distribution of the metals in the samples are given and compared. Most surprisingly, contents are not especially contrasted with those found in mushrooms collected in European urban areas, such as the Paris region; cadmium, lead, and mercury levels are of the same order of magnitude. Received: 20 July 1998/Accepted: 4 November 1998     

Cytochrome P450 CYP1A1 enzyme activity and DNA adducts in placenta of women environmentally exposed to organochlorines.

Organochlorine compounds bioaccumulate in fishing and hunting products included in the daily diet of many coastal populations. Prenatal and perinatal exposure to large doses of PCBs and PCDFs was shown to be deleterious on fetal and neonatal development, but information is scarce regarding possible effects of chronic low-dose exposure. This study investigates biomarkers of early effects in newborns from women exposed to organochlorines through the consumption of species from marine food chains, in two remote coastal regions of the province of Quebec (Canada). A CYP1A1-dependent enzyme activity (EROD) and DNA adducts were measured in placenta samples obtained from 30 women living on the Lower-North-Shore of the St. Lawrence River and 22 Inuit women from Nunavik (Arctic Quebec). These biomarkers were also assessed in 30 women from a Quebec urban center (Sept-Iles) as a reference group. Prenatal organochlorine exposure was determined by measuring these compounds in umbilical cord plasma. The amount of bulky polycyclic aromatic hydrocarbon (PAH)-related DNA adducts was significantly greater in the Lower-North-Shore group than in the reference group. Placental EROD activity and the amount of less bulky (OC-related) DNA adducts were significantly higher in the Nunavik group than in the reference group. For both biomarkers, smoking was found to be an important confounding factor. Organochlorine exposure was significantly associated with EROD activity and DNA adduct levels when stratifying for smoking. This study confirms that CYP1A1 enzyme induction and DNA adducts in placental tissue constitute useful biomarkers of early effects induced by environmental exposure to organochlorines.     

Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts

Background. Results of aortic arch reconstruction in the setting of biventricular physiology are well documented in the adult population, however, in children, surgical outcome of this subgroup of patients is less clear.

Methods. We studied the clinical outcomes of 37 children aged 8 days to 15 years (median 26 months), who underwent aortic arch reconstruction for arch hypoplasia from 1982 to 1997. The children were divided into three groups: Group 1 (20 patients) had isolated aortic arch lesions, Group 2 (13 patients) had associated intra-cardiac pathology yet conserving a biventricular physiology, Group 3 (4 patients) had Williams Syndrome. Previous interventions for coarctation had been performed in 30 patients (81%). Arch repair consisted of a patch aortoplasty in the majority of patients (35 of 37 children).

Results. Operative mortality occurred in 5 children, 4 in Group 2 (31%), 1 in Group 3 (25%) and none in Group 1. Permanent neurological complications occurred in 2 children (5 %). During the follow-up, which ranged from 1 month to 8 years, balloon angioplasty for arch obstruction was required in 1 child. There was one late death, associated with a subsequent intra-cardiac repair.

Conclusions. Aortic arch surgery in children with isolated arch hypoplasia, is associated with excellent early and late survival in addition to a low reintervention rate. Alternative perfusion and operative strategies must be implemented in infants with associated intra-cardiac anomalies to improve results.     

Dehydroepiandrosterone (DHEA) protects hippocampal cells from oxidative stress-induced damage

It has been postulated that decreases in plasma levels of dehydroepiandrosterone (DHEA) may contribute to the development of some age-related disorders. Along with neuroprotective and memory enhancing effects, DHEA has been shown to display antioxidant properties. Moreover, oxidative stress is known to cause lipid peroxidation and degenerative changes in the hippocampus, an area involved in memory processes and especially afflicted in Alzheimer's disease (AD). Accordingly, we investigated the antioxidant effects of DHEA in models of oxidative stress using rat primary hippocampal cells and human hippocampal tissue from AD patients and age-matched controls. A pre-treatment of rat primary mixed hippocampal cell cultures with DHEA (10-100 microM) protected against the toxicity induced by H2O2 and sodium nitroprusside. Moreover, DHEA (10-100 microM) was also able to prevent H2O2/FeSO4-stimulated lipid oxidation in both control and AD hippocampal tissues. Taken together, these data suggest that DHEA may be useful in treating age-related central nervous system diseases based on its protective effects in the hippocampus.     

Apolipoprotein E4, cholinergic integrity and the pharmacogenetics of Alzheimer's disease

Recent evidence indicates that apolipoprotein E (apoE) plays a central role in the brain's response to injury. The coordinated expression of apoE and its receptors (the so-called LDL [low density lipoprotein] receptor family) appears to regulate the transport and internalization of cholesterol and phospholipids during the early phase of the re-innervation process in the adult brain. During dendritic remodelling and synaptogenesis, neurons progressively repress the synthesis of cholesterol in favour of cholesterol internalization through the apoE/LDL receptor pathway. The discovery a few years ago, that the apolipoprotein epsilon 4 allele found in 15% of the normal population is strongly linked to both sporadic and familial late-onset Alzheimer's disease (AD), raises the possibility that a dysfunction of the lipid transport system associated with compensatory sprouting and synaptic remodelling could be central to the AD process. The role of apoE in the central nervous system is particularly important in relation to the cholinergic system, which relies to a certain extent on the integrity of phospholipid homeostasis in neurons. Recent evidence obtained by 4 independent research teams indicates that apo epsilon 4 allele directly affects cholinergic activity in the brain of AD subjects. It was also shown to modulate the drug efficacy profile of several cholinomimetic and noncholinomimetic drugs used for the treatment of AD patients.     

Multiorgan transplacental and neonatal carcinogenicity of 3'-azido-3'-deoxythymidine in mice

The anti-HIV drug 3'-azido-3'-deoxythymidine (AZT) is used successfully for reduction of perinatal viral transmission. However toxic side effects including carcinogenesis are possible. To test this, pregnant CD-1 Swiss mice were given 25.0 or 12.5 mg AZT on gestation days 12-18. Previously we reported an increase in lung, liver, and female reproductive system tumors in offspring euthanized at 1 year (Olivero et al., J. Natl. Cancer Inst. 89, 1602-1608, 1997). Findings for all remaining offspring up to 2 years old are reported here. AZT effects were most prominent in female offspring, with a significant threefold increase in lung tumors, a reduction in lymphoblastic and follicle center cell lymphomas, and a significant increase in histiocytic sarcomas (0 in controls, 3% after low-dose AZT, and 8% after high-dose AZT, p = 0.022). Dose-dependent incidences of mammary gland, ovarian, and seminal vesicle tumors were low but significant: 0/106 controls, 3/105 low-dose, and 8/105 high-dose mice presented one of these neoplasms (p = 0.0025). Incidences of females showing any clearly AZT-related neoplasm, in lung, liver, ovary, or mammary gland or histiocytic sarcoma, in the second year, were 12/32 after the low dose and 14/27 after the high dose vs 3/23 controls (p = 0.0045). Also, the sensitivity of neonatal mice was assessed by administration of 25, 50, 100, or 200 mg/kg AZT on postnatal days 1 through 8. The effects at 2 years were similar to those seen after transplacental exposure, with significant increases in lung, liver, and mammary tumors in females. The results confirm that AZT is a moderately effective perinatal carcinogen in mice, targeting several tissue types.     

Antihypertensive effects of cilazapril, 2.5 and 5 mg, once daily versus placebo on ambulatory blood pressure following single- and repeat-dose administration.

Ambulatory blood pressure (ABP) monitoring was used to evaluate the 24-h antihypertensive efficacy of single- and repeat-dose administrations of the nonsulfhydryl-converting enzyme inhibitor cilazapril, 2.5 and 5 mg, versus placebo in patients with mild to moderate essential hypertension. After a 2-week placebo run-in period, patients were randomized to receive, in a double-blind procedure, either 2.5 mg cilazapril (n = 14), 5 mg cilazapril (n = 14), or placebo (n = 14) for 4 weeks. In calculating the systolic/diastolic blood pressure (BP) trough-to-peak (T/P) ratio after subtraction of the placebo effect, 5 mg cilazapril appeared to be more effective than 2.5 mg cilazapril following single- (59/54% vs. 21/48%) and repeat-dose administration (47/76% vs. 31/49%). There were significant differences in 24-h and awake ABP for both 2.5 and 5 mg cilazapril as compared to placebo after single- and repeat-dose administrations. However, there were no significant differences in 24-h and awake ABP reduction between 2.5 and 5 mg cilazapril after single- and repeat-dose administrations. Furthermore, the percentages of "BP load" were identical with both regimens after the first dose (46 vs. 43%) and at steady-state (37 vs. 29%). These data demonstrate that 2.5 and 5 mg doses of cilazapril have equivalent antihypertensive efficacy using ABP and that 24-h ABP monitoring should also be performed in dose-response studies.     

Evaluation of patient counseling microcomputer software programs

Five patient counseling drug information programs are evaluated using specific criteria definitions. This article compares the features and ratings of each program. The scope of drug coverage is found to be good to excellent. Most of the programs fared poorly in the timeliness of the database. Updates to the programs range from quarterly to undefined schedule. The ease of readability of all the programs is excellent. The inclusion of key components of information is determined to be good to excellent. The overall patient performance ratings are excellent for each of the programs. The programs are all competitively priced. All of the programs evaluated are easy to use. The only distinguishing feature among the programs is the format of the printed output.     

Cardiac transplantation: treatment for cardiogenic shock.

Eighty-six patients received orthotopic cardiac transplants at the Royal Victoria Hospital in Montreal between 1985 and 1989. Of these, 16 mortally ill, being sustained in hospital by the intravenous administration of inotropic agents (15 patients [94%]) or intra-aortic balloon counterpulsation (6 [38%]). There was one early death (at 7 days), for a death rate of 6.3% (versus 8.6% for the 70 "elective" transplants). Two others died of delayed infection: one of viral hepatitis at 6 weeks, and one of pneumonia due to Pneumocystis 4 months after transplantation. The other 13 patients are alive and well 12 to 66 months postoperatively. Nine have returned to their preoperative work, three have decreased activity levels but are functioning well, and one is retired.