The Mental Health of Homeless Children

The literature addressing the mental health of homeless children is critically reviewed. Higher rates of behavioral, emotional, and cognitive problems have been reported for this population, but research results are qualified by significant methodological problems. Minimal attention has been given to the development and evaluation of specific intervention and prevention strategies. Recommendations are made for conducting research that will overcome previous methodological problems and focus more directly on identifying risk and protective mechanisms within the population of children exposed to homelessness.     

Autophagic degradation of protein generates a pool of ferric iron required for the killing of cultured hepatocytes by an oxidative stress

Pretreatment of cultured hepatocytes with the ferric iron chelator deferoxamine prevents the killing of the cells by tert-butyl hydroperoxide (TBHP). Incubation of the deferoxamine-pretreated hepatocytes in a serum-free medium containing only 0.25 nM iron restored the sensitivity of the cells to TBHP within 4 to 6 hr. An amino acid-free medium accelerated the restoration of sensitivity in parallel with an enhanced rate of degradation of 14C-prelabeled protein. By contrast, inhibitors of the autophagic degradation of protein, including chymostatin, 3-methyladenine, benzyl alcohol, colchicine, oligomycin, and methylamine, inhibited the restoration of sensitivity of deferoxamine-treated hepatocytes to TBHP in parallel with their inhibition of protein degradation. With chymostatin, 3-methyladenine, benzyl alcohol, and colchicine, there was a parallel dose dependency of both the inhibition of protein turnover and the inhibition of the restoration of sensitivity to TBHP. Ascorbic acid, known to specifically retard the autophagic degradation of ferritin, inhibited the restoration of sensitivity to TBHP without effect on the general rate of protein turnover. None of the agents studied had any protective effect on the toxicity of TBHP for hepatocytes that were not pretreated with deferoxamine. These data indicate that the autophagic degradation of protein generates a pool of ferric iron required for the killing of cultured hepatocytes by TBHP.     

Reversible endothelial changes in the monkey cornea.

As part of a study examining the effects of contact lens extended wear in monkeys (Macaca fascicularis), reversible endothelial changes were observed in the cornea with slit lamp biomicroscopy and contact specular microscopy. These changes were associated with anterior eye inflammation in four monkeys (as occurs in humans). However, in two monkeys no obvious cause for these changes other than the presence of a contact lens on the cornea was apparent. In these two monkeys the endothelium displayed features similar to the transient endothelial bleb response, which has been observed only in humans. The monkey (M fascicularis) may thus be an appropriate model for further investigation of the endothelial response during anterior eye inflammation and the transient endothelial bleb response.     

Tear plasmin activity with contact lens wear.

Plasmin, a proteolytic enzyme, has been detected in the tears of patients experiencing anterior ocular disease, and during contact lens wear. Using a radial caseinolysis procedure, we examined tear plasmin levels in 66 patients who were wearing soft and rigid lenses for daily and extended wear. Compared to non-contact lens wearers, patients wearing soft and rigid lenses for extended wear were significantly more likely to exhibit tear plasmin activity. Eight hours of open-eye thick HEMA lens wear did not induce tear plasmin activity in a group of 10 subjects. However, significant increases in tear plasmin activity were recorded after short-term (1 hour) eye closure with and without lens wear, and following overnight (8 hours) eye closure without lens wear. Overnight eye closure also resulted in significantly increased numbers of epithelial cells and leucocytes in the tear fluid. Our results suggest that increased tear plasmin activity during extended contact lens wear may be attributable to the effects of eye closure rather than hypoxia or the presence of the contact lens per se.     

Inappropriate Vancomycin Prescribing Based on Criteria from the Centers for Disease Control and Prevention

Increasing reports of vancomycin resistance have raised concerns about the future effectiveness of this drug in treatment of critically ill patients with gram-positive infections. Due to these concerns the Centers for Disease Control and Prevention (CDC) recently published criteria that delineate the prudent use of vancomycin. Using these criteria, we attempted to determine the appropriateness of vancomycin prescribing patterns at our institution. A retrospective chart review was performed for 135 hospitalized patients treated between May 1993 and April 1994. Inappropriate empiric vancomycin use was documented in 81 (60%) of these patients. When culture results were available, 28 (21%) patients inappropriately received the drug. Results of this study are similar to those of other studies of vancomycin use in hospitals based on non-CDC criteria. If CDC criteria are to have a positive impact on physicians' vancomycin prescribing patterns, significant educational efforts will be required.     

Current concepts on monoclonal gammopathies

This is a review of the monoclonal gammopathies, including a discussion of cause. The role of T lymphocytes and B lymphocytes is presented. The recognition of a monoclonal protein in the serum and urine is presented in detail.
The frequency of benign and malignant monoclonal gammopathies is provided. A long-term follow-up of 241 patients with apparently benign monoclonal gammopathy is examined closely. In this series, multiple myeloma, macroglobulinaemia, amyloidosis, or related disorders developed in 22% of the 241 patients with long-term disease. The median duration from the recognition of the monoclonal protein until the development of serious disease was approximately eight to ten years.
The differentiation of benign from malignant monoclonal gammopathics is examinad in detail. The point is made that paticnu must be folld indefinitely because malignancy may develop more than 20 years later. The association of monoclonal gammopathies with other apparently unrelated diseases discussed. (Aust NZ J Med 1992; 22: 291–302.)     

Striatal delivery of CERE-120, an AAV2 vector encoding human neurturin, enhances activity of the dopaminergic nigrostriatal system in aged monkeys.

Neurturin (NTN) is a potent survival factor for midbrain dopaminergic neurons. CERE-120, an adeno-associated virus type 2 (AAV2) vector encoding human NTN (AAV2-NTN), is currently being developed as a potential therapy for Parkinson's disease. This study examined the bioactivity and safety/tolerability of AAV2-NTN in the aged monkey model of nigrostriatal dopamine insufficiency. Aged rhesus monkeys received unilateral injections of AAV2-NTN into the caudate and putamen, with each animal therefore serving as its own control. Robust expression of NTN within the nigrostriatal system was observed 8 months postadministration. (18)F-fluorodopa imaging using positron emission tomography revealed statistically significant increases in (18)F-fluorodopa uptake in the injected striatum compared with the uninjected side at 4 and 8 months. In addition, at 8 months postadministration, a significant enhancement in tyrosine hydroxylase immunoreactive fibers and an increase in the number of tyrosine hydroxylase immunoreactive cells was observed in the AAV2-NTN injected striatum compared with the uninjected side. Robust activation of phosphorylated extracellular signal-regulated kinase immunoreactivity in the substantia nigra was also observed. Histopathological analyses revealed no adverse effects of AAV2-NTN in the brain. Collectively, these results are consistent with the neurotrophic effects of NTN on the dopaminergic nigrostriatal system and extend the growing body of evidence supporting the concept that AAV2-NTN may have therapeutic benefit for Parkinson's disease.     

Development of sample handling procedures for foods under USDA's National Food and Nutrient Analysis Program

The National Food and Nutrient Analysis Program (NFNAP) was implemented in 1997 to update and improve the quality of food composition data maintained by the United States Department of Agriculture (USDA). NFNAP was designed to sample and analyze frequently consumed foods in the U.S. food supply using statistically rigorous sampling plans, established sample handling procedures, and qualified analytical laboratories. Methods for careful handling of food samples from acquisition to analysis were developed to ensure the integrity of the samples and subsequent generation of accurate nutrient values. The infrastructure of NFNAP, under which over 1500 foods have been sampled, mandates tested sample handling protocols for a wide variety of foods. The majority of these foods were categorized into several major areas: (1) frozen foods; (2) fresh produce and/or highly perishable foods requiring refrigeration; (3) fast foods and prepared foods; (4) shelf-stable foods; (5) specialized study and non-retail (point of production) foods; and (6) foods from remote areas (e.g. American Indian reservations). This paper describes the sample handling approaches, from the collection and receipt of the food items to the preparation of the analytical samples, with emphasis on the strategies developed for those foods. It provides a foundation for developing sample handling protocols of foods to be analyzed under NFNAP and for other researchers working on similar projects.