A preliminary study on oxygen saturation levels of patients during periodontal surgery with and without oral conscious sedation using diazepam

BACKGROUND: Stress and anxiety alter respiratory rate and thereby alter oxygen saturation in the blood. Management of psychological stress in the dental office may help maintain blood gas homeostasis. One method of stress management is through the use of preoperative oral sedation. METHODS: The study population consisted of 13 patients scheduled to receive two quadrants of periodontal surgery at two different appointments. A randomized split-mouth crossover design was used with one quadrant of surgery involving preoperative oral sedation (diazepam) and local anesthetic, and the second using local anesthetic only. Oxygen saturation was monitored by pulse oximetry, which recorded the number of times saturation dropped below 95% in a given time period. Data were recorded at 5 time periods: 1) baseline; 2) from time of anesthetic administration to 20 minutes into surgery; 3) 21 to 40 minutes; 4) 41 to 60 minutes; and 5) 61 to 80 minutes into the surgery. Data were analyzed by a two-factor repeated measures ANOVA. The two within-group factors were treatment group and time. RESULTS: Results indicated no significant interaction between time and treatment (P > .05). However, data for groups over time suggested a trend supporting an interaction. The eta2 value of 0.124 suggested a moderate effect favoring the diazepam treatment. No significant difference was noted for the main effect of treatment and time. However, the eta2 value of 0.24 for treatment effect (diazepam versus no diazepam) suggested a meaningful difference between groups. Similarly the eta2 value of 0.135 for time suggested a moderate effect over time within-subjects. CONCLUSIONS: This study indicates that diazepam given orally in adult dosages does not cause significant respiratory depression, and is generally safe for those healthy patients who may require slight to mild sedation during periodontal surgery.     

Qualitative research: what does it have to offer to the gerontologist?

The growing challenges of promoting health and managing illness in an ever-changing health care system require an arsenal of research approaches. Qualitative methods have a long tradition in disciplines such as sociology and anthropology and are being used with greater frequency as interdisciplinary health-related disciplines attempt to understand and explain complex problems. The purpose of this article is to define and describe the main features of qualitative research and to examine ways in which this methodology is relevant and useful in gerontological studies. A concise comparison of quantitative and qualitative methods is made, and suggestions are provided for when qualitative approaches are useful. A review of the three most common approaches is provided. Most important, references are provided for those gerontologists interested in learning more about qualitative research methods.     

Herbivory,plant resistance,and climate in the tree ring record: interactions distort climatic reconstructions

To understand climate change, dendrochronologists have used tree ring analyses to reconstruct past climates, as well as ecological processes such as herbivore population dynamics. Such reconstructions, however, have been hindered by a lack of experiments that separate the influences of confounding impacts on tree rings, such as herbivores and the interactions of multiple factors. Our long-term experiments with scale insects on resistant and susceptible pines demonstrate three major points that are important to the application of this commonly used tool. (i) Herbivory reduced tree ring growth by 25-35%. (ii) The impact on ring growth distorted climate reconstruction, resulting in the overestimation of past moisture levels by more than 2-fold. Our data suggest that, if distortion because of herbivory has been a problem in previous reconstructions, estimates of the magnitude of recent climate changes are likely to be conservative. (iii) Our studies support a detectible plant resistance x herbivore x climate interaction in the tree ring record. Because resistance and susceptibility to herbivory are known to be genetically based in many systems, the potential exists to incorporate plant genetics into the field of dendrochronology, where it may be used to screen distortions from the tree ring record.     

Changing incidence of out-of-hospital ventricular fibrillation, 1980-2000

Context  Recent reports from 2 European cities and an earlier observation from Seattle, Wash, suggest that the number of patients treated for out-of-hospital ventricular fibrillation (VF) has declined. Objective  To analyze the incidence of cardiac arrest and to examine relationships among incidence, sex, race, age, and first identified cardiac rhythm in Seattle. Design, Setting, and Patients  Population-based study of all cardiac arrest cases with presumed cardiac etiology who received advanced life support from Seattle Fire Department emergency medical services during specified periods between 1979 and 2000. United States Census data for Seattle in 1980, 1990, and 2000 were used to determine incidence rates for treated cardiac arrest with adjustments for age and sex. Main Outcome Measures  Changes in incidence of cardiac arrest and initial recorded cardiac rhythm. Results  The adjusted annual incidence of cardiac arrest with VF as the first identified rhythm decreased by about 56% from 1980 to 2000 (from 0.85 to 0.38 per 1000; relative risk [RR], 0.44; 95% confidence interval [CI], 0.37-0.53). Similar reductions occurred in blacks (54%; RR, 0.45; 95% CI, 0.26-0.79) and whites (53%; RR, 0.47; 95% CI, 0.38-0.58) and was most evident in men (57%; RR, 0.43; 95% CI, 0.35-0.53), in whom the baseline incidence was relatively high. When all treated arrests with presumed cardiac etiology were considered, that incidence decreased by 43% (RR, 0.58; 95% CI, 0.49-0.67) in men but negligibly in women, for whom a relatively low incidence of VF also declined but was offset by more cases with asystole or pulseless electrical activity. Conclusion  We observed a major decline in the incidence of out-of-hospital VF and in all cases of treated cardiac arrest presumably due to heart disease in Seattle. These changes likely reflect the national decline in coronary heart disease mortality.      

Effects of hormone replacement therapy and antioxidant vitamin supplements on coronary atherosclerosis in postmenopausal women: a randomized controlled trial

Context  Hormone replacement therapy (HRT) and antioxidant vitamins are widely used for secondary prevention in postmenopausal women with coronary disease, but no clinical trials have demonstrated benefit to support their use. Objective  To determine whether HRT or antioxidant vitamin supplements, alone or in combination, influence the progression of coronary artery disease in postmenopausal women, as measured by serial quantitative coronary angiography. Design, Setting, and Patients  The Women's Angiographic Vitamin and Estrogen (WAVE) Trial, a randomized, double-blind trial of 423 postmenopausal women with at least one 15% to 75% coronary stenosis at baseline coronary angiography. The trial was conducted from July 1997 to January 2002 in 7 clinical centers in the United States and Canada. Interventions  Patients were randomly assigned in a 2 x 2 factorial design to receive either 0.625 mg/d of conjugated equine estrogen (plus 2.5 mg/d of medroxyprogesterone acetate for women who had not had a hysterectomy), or matching placebo, and 400 IU of vitamin E twice daily plus 500 mg of vitamin C twice daily, or placebo. Main Outcome Measure  Annualized mean (SD) change in minimum lumen diameter (MLD) from baseline to concluding angiogram of all qualifying coronary lesions averaged for each patient. Patients with intercurrent death or myocardial infarction (MI) were imputed the worst rank of angiographic outcome. Results  The mean (SD) interval between angiograms was 2.8 (0.9) years. Coronary progression, measured in mean (SD) change, worsened with HRT by 0.047 (0.15) mm/y and by 0.024 (0.15) mm/y with HRT placebo (P = .17); and for antioxidant vitamins by 0.044 (0.15) mm/y and with vitamin placebo by 0.028 (0.15) mm/y (P = .32). When patients with intercurrent death or MI were included, the primary outcome showed an increased risk for women in the active HRT group (P = .045), and suggested an increased risk in the active vitamin group (P = .09). Fourteen patients died in the HRT group and 8 in the HRT placebo group (hazard ratio [HR], 1.8; 95% confidence interval [CI], 0.75-4.3), and 16 in the vitamin group and 6 in the vitamin placebo group (HR, 2.8; 95% CI, 1.1-7.2). Death, nonfatal MI, or stroke occurred in 26 HRT patients vs 15 HRT controls (HR, 1.9; 95% CI, 0.97-3.6) and in 26 vitamin patients and 18 vitamin controls (HR, 1.5; 95% CI, 0.80-2.9). There was no interaction between the 2 treatment interventions. Conclusion  In postmenopausal women with coronary disease, neither HRT nor antioxidant vitamin supplements provide cardiovascular benefit. Instead, a potential for harm was suggested with each treatment.      

Socioeconomic inequality of cancer mortality in the United States: a spatial data mining approach

Background  

The objective of this study was to demonstrate the use of an association rule mining approach to discover associations between selected socioeconomic variables and the four most leading causes of cancer mortality in the United States. An association rule mining algorithm was applied to extract associations between the 1988–1992 cancer mortality rates for colorectal, lung, breast, and prostate cancers defined at the Health Service Area level and selected socioeconomic variables from the 1990 United States census. Geographic information system technology was used to integrate these data which were defined at different spatial resolutions, and to visualize and analyze the results from the association rule mining process.     

iNOS gene expression modulates microvascular responsiveness in endotoxin-challenged mice

Septic shock is characterized by vasodilation and decreased responsiveness to vasoconstrictors. Recent studies suggest this results from nitric oxide (NO) overproduction after expression of the calcium-independent isoform of NO synthase (iNOS) in smooth muscle cells. However, direct evidence linking iNOS (NOS2) expression and decreased microvascular responsiveness after septic stimuli is lacking. In the present study, we determined the effect of bacterial lipopolysaccharide (LPS, 20 mg/kg, IP) on smooth muscle contraction and endothelial relaxation in mesenteric resistance arteries from wild-type and iNOS knockout mice. Four hours after challenge with LPS or saline in vivo, concentration-dependent responses to norepinephrine (NE) and acetylcholine (NE+ACh) were measured in cannulated, pressurized vessels ex vivo. In vessels from wild-type mice, NE-induced contraction was markedly impaired after LPS, and pretreatment with the iNOS inhibitor aminoguanidine (AG) partly restored the NE contraction. In contrast, NE contraction in microvessels from iNOS knockout mice was unaffected by LPS. ACh-induced relaxation was unaffected by LPS in vessels from either genotype. These data provide direct evidence that iNOS gene expression mediates the LPS-induced decrease in microvascular responsiveness to vasoconstrictors. Moreover, the observation that AG did not fully restore NE contraction after LPS, whereas iNOS gene deficiency did, suggests that iNOS expression plays a central role in the development of the NO-independent effect of LPS on microvascular responsiveness. Finally, our data indicate that LPS or iNOS expression has little effect on endothelium-dependent relaxation, and eNOS activity does not appear to play a role in the decreased smooth muscle responsiveness after LPS in this model. The full text of this article is available at http://www.circresaha.org.     

Chemoprevention of spontaneous tumorigenesis in nullizygous p53- deficient mice by dehydroepiandrosterone and its analog 16alpha-fluoro- 5-androsten-17-one

Transgenic mice with both alleles of the p53 tumor suppressor gene product 'knocked out' by gene targeting are susceptible to early development of tumors, chiefly lymphomas and sarcomas. Compared with the control group, administration of dehydroepiandrosterone (DHEA) at 0.3% of the diet to male p53-deficient mice extended their lifespan by delaying death due to neoplasms (from 105 to 166 days on study, P = 0.002), primarily by suppressing lymphoblastic lymphoma (from 45 to 6% of neoplastic deaths, P = 0.010). Treatment with a synthetic DHEA analog, 16alpha-fluoro-5-androsten-17-one (compound 8354), at 0.15% of the diet also increased lifespan, to 140 days for mice that developed tumors (P = 0.037). The effects of these steroids on lifespan and tumor development did not appear to be strongly related to inhibition of food consumption and weight gain, in that a group pair-fed with control diet to the reduced food consumption of the DHEA-treated group developed and died of the same types of neoplasms at the same rate as the controls fed ad libitum. The chemopreventive effect of these steroids has been proposed to be due to suppression of DNA synthesis by inhibition of glucose 6-phosphate dehydrogenase, the rate-limiting enzyme of the pentose phosphate pathway. Although DHEA and its analog are strong non- competitive inhibitors of this enzyme in vitro, treatment with DHEA did not deplete cellular nucleotide pools in the liver, as would have been predicted. The chemopreventive effect of DHEA in this model may be due to steroid-induced thymic atrophy and suppression of T cell lymphoma, permitting these mice to survive long enough to develop tumors with longer latency.      

Low national breast and cervical cancer-screening rates in American Indian and Alaska Native women with diabetes

BACKGROUND: The cervical cancer mortality rate for American Indian and Alaska Native women is twice that of all races in the United States. To date the only published national breast and cervical cancer-screening rates for American Indian and Alaska Native women are based on self-reported data. When the Indian Health Service (IHS) conducts an annual audit on patients with diabetes, it includes cancer screening. This observational study presents national breast and cervical cancer-screening rates for American Indian and Alaska Native women with diabetes. METHODS: Cancer-screening rates were extracted from the 1995 diabetic audit for the 12 IHS areas. These rates were compared with rates for women without diabetes of the same age, 50 to 69 years, by chart review, at four IHS hospitals in the Aberdeen IHS area. RESULTS: Screening rates for women with diabetes in the 12 areas varied: mammogram (ever) 35% to 78%; clinical breast examination (last year) 28% to 70%, and Papanicolaou smear (last year) 26% to 69%. The Aberdeen IHS area women with diabetes had 51% more clinic visits per year than women without diabetes, but the groups had similar screening rates. CONCLUSION: Cancer-screening rates for American Indian and Alaska Native women vary by region. In the Aberdeen IHS area, women with diabetes had more visits (missed opportunities) but similar screening rates as women without diabetes. The diabetic audit could be used to monitor national IHS cancer-screening trends for women with diabetes and in the Aberdeen IHS area for all women aged 50 to 69 years.     

Prevalence and impact of chronic childhood conditions in Auckland, New Zealand

Objective : To establish the prevalence of specific chronic conditions of childhood in the Auckland area and to quantify resource use by these children.
Methodology : Estimates were made from available registry data and published data sources of the population of children with selected chronic conditions resident in the Auckland Area Health Board area. Resource use data were extracted for admissions to Auckland public hospitals and from providers of community based technology services.
Results : The largest community prevalence groups are those with asthma, intellectual handicap, congenital heart disease and epilepsy. Children aged 0-14 with chronic conditions accounted for at least 14340 hospital days stay in Auckland in 1992 at an estimated minimum cost of $7.9 million. Over 200 children are dependent on technological aids at home.
Conclusions : There are sparse data on the numbers and needs of children with chronic conditions in the population. A non-categorical approach which crosses disease entities may be the best method of meeting common needs.