Gene expression in normal human bronchial epithelial (NHBE) cells following in vitro exposure to cigarette smoke condensate.

Cigarettes that burn tobacco produce a complex mixture of chemicals, including mutagens and carcinogens. Cigarettes that primarily heat tobacco produce smoke with marked reductions in the amount of mutagens and carcinogens and demonstrate reduced mutagenicity and carcinogenicity in a battery of toxicological assays. Chemically induced oxidative stress, DNA damage, and inflammation may alter cell cycle regulation and are important biological events in the carcinogenic process. The objective of this study was to characterize and compare the effects of smoke condensates from cigarettes that burn tobacco and those that primarily heat tobacco on gene expression in NHBE cells. For this comparison, we used quantitative RT/PCR and further evaluated the effects on cell cycling using flow cytometry. Cigarette smoke condensates (CSCs) were prepared from Kentucky 1R4F cigarettes (a tobacco-burning product designed to represent the average full-flavor, low "tar" cigarette in the US market) and Eclipse (a cigarette that primarily heats tobacco) using FTC machine smoking conditions. The CSC from 1R4F cigarettes induced statistically significant increases in the mRNA levels of genes responsive to DNA damage (GADD45) and involved in cell cycle regulation (p21;WAF1/CIP1), compared to the CSC from Eclipse cigarettes. In addition, genes coding for cyclooxygenase-2 (COX-2) and interleukin 8 (IL-8), which are associated with oxidative stress and inflammation, respectively, were increased statistically significantly more by CSC from 1R4F than by that from Eclipse. Furthermore, a dose-dependent increase in IL-8 protein secretion into cell culture media was stimulated by 1R4F exposure, whereas minimal IL-8 protein was secreted after Eclipse treatment. The biological relevance of the differential effect on gene expression was reflected in differential cell cycle regulation, as cells exposed to 1R4F CSC exhibited more significant S phase and G2 phase accumulation than cells exposed to Eclipse CSC. These data indicate that the simplified smoke chemistry of the tobacco-heating Eclipse cigarette yields statistically significant reductions in the expression of key genes involved in DNA damage, oxidative stress, inflammatory response, and cell cycle regulation in normal human bronchial epithelial cells compared to a representative tobacco-burning cigarette.     

Building geographic information system capacity in local health departments: lessons from a North Carolina project

State government, university, and local health department (LHD) partners collaborated to build the geographic information system (GIS) capacity of 5 LHDs in North Carolina. Project elements included procuring hardware and software, conducting individualized and group training, developing data layers, guiding the project development process, coordinating participation in technical conferences, providing ongoing project consultation, and evaluating project milestones. The project provided health department personnel with the skills and resources required to use sophisticated information management systems, particularly those that address spatial dimensions of public health practice. This capacity-building project helped LHDs incorporate GIS technology into daily operations, resulting in improved time and cost efficiency. Keys to success included (1) methods training rooted in problems specific to the LHD, (2) required project identification by LHD staff with associated timelines for development, (3) ongoing technical support as staff returned to home offices after training, (4) subgrants to LHDs to ease hardware and software resource constraints, (5) networks of relationships among LHDs and other professional GIS users, and (6) senior LHD leadership who supported the professional development activities being undertaken by staff.     

The effect of nitrous oxide on the dose-response relationship of rocuronium

It has been generally assumed that nitrous oxide (N(2)O) enhances the effects of nondepolarizing muscle relaxants only weakly if at all. More recent evidence suggests that drug potency may be more intense under N(2)O anesthesia compared with total IV anesthesia (TIVA). However, the magnitude of this effect has not been well defined. We measured the 50% effective dose of rocuronium in 35 patients receiving N(2)O-propofol-opioid anesthesia and a comparable group receiving TIVA. A single dose of rocuronium was given to each patient and drug potency was calculated for each individual from the Hill equation assuming a log-dose/logit slope of 4.5. In both groups, the relaxant was administered 15 min after induction of anesthesia. Neuromuscular function was measured using electromyography with single stimuli at 0.10 Hz. We measured a 50% effective dose of 0.209 +/- 0.051 mg/kg during TIVA and of 0.166 +/- 0.041 mg/kg during N(2)O anesthesia, a decrease of 20% (P < 0.001). The clinical importance of this effect must be considered modest; however, estimates of potency that are usually obtained during N(2)O anesthesia may underestimate drug requirements at the time of induction of anesthesia.     

Increased levels of circulating endothelial cells in chronic periaortitis as a marker of active disease

BACKGROUND: The pathogenesis of chronic periaortitis (CP) has not been clarified. The histologic features and the association with autoimmune diseases suggest an immune-mediated disorder with marked inflammatory vascular and perivascular lesions. To clarify the role of vascular damage we looked for the presence and the surface phenotype of circulating endothelial cells (CECs) in the peripheral blood of patients with chronic periaortitis. METHODS: Eleven patients with CP were evaluated for the presence of CECs; 9 patients had active and 2 inactive disease. Three patients with active disease were also evaluated 3 months after therapy. Ten atherosclerotic patients, 10 patients with renal insufficiency of variable degree and etiology, and 40 healthy subjects were evaluated as controls. Five-parameter, 3-color flow cytometry was performed with a FACScan. CECs were defined as CD45 negative, CD31, P1H12, and CD36 positive, and activated CECs as CD45 negative and P1H12, CD62 positive. RESULTS: The median number of CECs in patients with CP (10(6) cells/mL) was significantly higher than in healthy controls (16 cells/mL, P= 0.0004) and atherosclerotic patients (25 cells/mL, P= 0.0005) Two patients with inactive disease had a CEC count comparable to that of normal subjects. In 2 of the 3 patients reevaluated, 3 months after therapy CEC numbers normalized. Almost all CECs were microvascular in origin and showed an activated phenotype. CONCLUSION: The presence of a high number of CECs in the active phase of chronic periaortitis and their normalization during inactive disease suggest that endothelial damage may play a role in the pathogenesis of the disease.     

Temporal trends in early clinical manifestations of perinatal HIV infection in a population-based cohort

Context  The effect of early antiretroviral therapy (ART) on the early progression of perinatal human immunodeficiency virus (HIV) infection is not well defined. Objective  To examine early disease progression and survival in a population-based cohort with perinatal HIV infection in relation to year of birth and use of ART. Design, Setting, and Patients  Retrospective study of temporal trends in early progression of perinatal HIV infection among 205 HIV-infected children in Northern California born between January 1, 1988, and December 31, 2001, and followed up through age 3 years. Main Outcome Measures  Prevalence of and age at progression to a first US Centers for Disease Control and Prevention category C diagnosis relative to year of birth, type of ART, and age at initiation of therapy. Results  Of 205 children, 134 (65%) received ART and/or Pneumocystis jiroveci pneumonia prophylaxis. By age 3 years, 81 (40%) progressed to a category C diagnosis, 41 (51%) of whom died. Untreated children were significantly more likely to progress to a category C diagnosis (62% [44/71] untreated vs 28% [37/134] treated children, P<.001); none of 23 infants who received triple ART progressed to category C. However, even without triple ART, very early mono/dual ART (by age 2 months vs 3-4 months) was associated with delayed and decreased progression to category C (P = .02). Of 33 children born between January 1, 1996, and December 31, 2001, only 7 (21%) progressed to category C (P = .02 compared with 1988-1995), 6 of 7 of whom received no therapy. More recent year of birth and more advanced therapy were associated with improved survival. Conclusions  This population-based cohort demonstrated decreased early HIV progression and improved survival at age 3 years, associated with more advanced therapy. Although limited by small sample size, the findings suggest that very early treatment, even without triple ART, was associated with improved outcome.      

Bistability and Correlation with Arrhythmogenesis in a Model of the Right Atrium

Rapid pacing is an important tool for understanding cardiac arrhythmias. A recent experiment involving rapid pacing of sheep atria indicated that the initiation of atrial arrhythmias may be related to the 1:1/2:1 bistability. To elucidate the mechanism of this relation, this study applied the pacing protocol from the sheep study to an idealized model of the right atrium. The model included all major anatomical features, the sino-atrial node, and the regional differences in the action potential duration (APD). A pacing protocol was applied, in which the basic cycle length (BCL) was decreased in steps of 10 ms until the response switched to 2:1, then BCL was increased. The 1:1-to-2:1 transitions occurred at shorter BCLs than the 2:1-to-1:1 transitions yielding a global bistability window of 60 ms. As in the sheep study, idiopathic waves were observed at BCLs within or near the bistability window. The model was used to quantify the types, prevalence, and persistence of idiopatic waves, study their initiation and termination, and relate them to the model components. The results demonstrate that idiopatic waveforms move with the shift of the bistability window and that they disappear when bistability is eliminated. Thus, this modeling study supports causal relationship between the 1:1/2:1 bistability and the initiation of arrhythmias.     

Ocular abnormalities in Large(myd) and Large(vls) mice, spontaneous models for muscle, eye, and brain diseases

Here we demonstrate previously unreported ocular defects in mice homozygous for a new allele of the Large gene, veils, and for Large(myd) mice. Clinically, vitreal fibroplasia and retinal vessel tortuosity and fluorescein leakage are observed. These vascular defects may be due to the extreme disorganization of the astrocytic template on which endothelial cells migrate in the retina. Abnormal electroretinograms recorded from Large(vls) or Large(myd) mice are accompanied by disorganization of the outer plexiform layer (OPL) with a dramatic reduction in the number of synaptic complexes. In both mutants, the internal limiting membrane (ILM) is disrupted with ectopic cells in the vitreous. Interestingly, while all components of the dystrophin glycoprotein complex are present at reduced levels in the OPL, they were absent in the ILM of affected mice. Finally, hypoglycosylation of alpha-dystroglycan previously implicated in muscle and brain defects is also observed in the retina and may contribute to the ocular abnormalities.