Allelic losses on chromosomes 14, 10, and 1 in atypical and malignant meningiomas: a genetic model of meningioma progression

To investigate chromosomal events that underlie formation and progression of meningiomas, we have examined a set of 18 benign (WHO grade I), 15 atypical (grade II), and 13 anaplastic/malignant (grade III) meningiomas for loss of heterozygosity (LOH) on chromosomes 1p, 6p, 9q, 10q, and 14q. Frequent loss of loci on these chromosomes was seen in grade II and grade III tumors, specifically, 14q (II and III, 47 and 55%), 1p (40 and 70%), and 10q (27 and 40%). In contrast, LOH for these loci was infrequent in benign meningiomas, specifically, 14q (0%), 1p (11%), and 10q (12%). The smallest common regions of deletion that could be defined were 14q24-q32, 1p32-pter, and 10q24-qter. These observations indicate the likely presence of tumor suppressor genes in these regions that are involved in the development of WHO grade II and grade III meningiomas. Because LOH for loci on chromosomes 1p and 10q was found in tumors of all grades and because the frequency of LOH in all three regions increased with tumor grade, these results would support a model for the formation of aggressive meningiomas through tumor progression.     

Radiologic placement of long-term subcutaneous venous access ports in children

OBJECTIVE: The purpose of this study was to review the results of radiologically placed subcutaneous venous access ports in a pediatric population requiring long-term venous access. CONCLUSION: Sixteen of 20 patients had no significant problems with their ports. In the pediatric population, radiologically placed subcutaneous venous access ports offer a high success rate, a low complication rate, and significant cost savings over surgically placed ports.     

Thyroid function in a population of children with attention deficit hyperactivity disorder

4-Fluoro-3-nitrobenzoic acid attached to a solid support was shown to react under mild conditions with a wide range of functionalized phenols to yield, after cleavage, the corresponding biaryl ethers in excellent purity. In a similar fashion, biaryl thioethers could be obtained. Further elaboration of immobilized biaryl ethers demonstrates the potential for combinatorial library generation.     

NHLBI workshop on the utilization of ECG databases: preservation and use of existing ECG databases and development of future resources

During the last years several reports have demonstrated that melatonin is a efficient free radical scavenger and general antioxidant. In addition, it has been shown that this neurohormone is able to increase the activity of glutathione peroxidase in rat brain cortex as well as the gene expression for some antioxidant enzymes in the Harderian gland of female Syrian hamster. Also, it is well known that brain cells are particularly exposed to free radicals, with antioxidant enzymes as the major defense mechanism that the brain uses to neutralize reactive oxygen species. The aim of the present study was to examine the influence of melatonin on gene expression for antioxidant enzymes in rat brain cortex. Our results clearly demonstrate that exogenously administered melatonin increases the levels of mRNA for glutathione peroxidase, copper-zinc superoxide dismutase, and manganese superoxide dismutase in this tissue. These stimulatory effects are observed after both acute and chronic treatment with this hormone, producing in the latter case the more marked increase. We therefore conclude that melatonin exerts an important role in providing indirect protection against free radical injury by stimulating gene expression for antioxidant enzymes. Consequently, melatonin could be considered as a potential therapeutic agent in some age-related neurodegenerative diseases where excessive free radical production has been implicated.     

The maxillary sinus and odontogenic cysts

An unilateral maxillary sinusitis is frequently caused by dental pathology. An odontogenic cyst in the maxillary sinus usually lacks accompanying symptoms of infection. In three patients, a 35-year-old man and two women aged 16 and 28, an odontogenic cyst in the maxillary sinus was diagnosed. Consultation of a maxillofacial surgeon is needed because orthopantomographic imaging is diagnostically most helpful. In these patients combined treatment by an ENT surgeon and a maxillofacial surgeon is important.     

A hexameric transmembrane pore revealed by two-dimensional crystallization of the large mechanosensitive ion channel (MscL) of Escherichia coli

We have established a reconstitution method of the detergent-solubilized recombinant large mechanosensitive ion channel of Escherichia coli (MscL) that yielded two-dimensional crystals. For that purpose, we have developed a new protocol using Triton X-100 to solubilize and purify the MscL protein. This protocol not only allowed an increase in the protein yield but also made it possible to obtain a homogeneous delipidated and reproducible preparation of the purified protein. When examined by the patch-clamp method MscL channels were found to be fully functional, exhibiting characteristic conductance and activation by pressure. For electron crystallography the homogeneous Triton X-100-purified recombinant MscL was further reconstituted at low lipid-to-protein ratios using Bio-Beads SM2 to remove the detergent. Two-dimensional crystals, exhibiting a p6 plane group symmetry, have been produced and examined by negative stain electron microscopy. Image processing of selected micrographs yielded a projection map at 15-A resolution that provided the first explicit structural information about the molecular boundary and homohexameric organization of the MscL channels in the membrane bilayer.     

Office-based training in tobacco cessation for dental professionals

During a 90-minute, on-site training session, a dentist/tobacco-cessation educator trained 293 dental professionals from 57 offices. The authors report statistically significant increases between the pre-training and follow-up surveys for 12 tobacco-cessation activities and the amount of time spent on such activities (P < .001). Using participants' estimates-taken at three months after the training-the authors calculated that an average of two patients per office had stopped using tobacco, two had stopped and relapsed, and eight patients were considering stopping tobacco usage.