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PubMed2004

Characteristics of rapid cycling bipolar-I patients in a bipolar speciality clinic.

OBJECTIVES: To investigate the characteristics of patients with rapid cycling bipolar illness. METHODS: The charts of bipolar patients treated at the Massachusetts General Hospital Bipolar Clinic were reviewed for age of the first affective episode, demographics and history of rapid cycling. RESULTS: Data from 223 bipolar-I-II patients, of whom 11.7% were bipolar-II, were obtained, and only the data from 197 bipolar-I patients were analyzed. Forty-three percent of them had a positive history of rapid cycling. Rapid cycling was more common in women, with rapid cycling females having an earlier age of onset than non-rapid cycling bipolar-I females. No such association was found in bipolar-I males. In addition, with respect to current age, rapid cyclers were younger than non-rapid cyclers in bipolar-I females. No association was found for duration of illness. CONCLUSIONS: Women with bipolar-I illness have an increased probability of rapid cycling, which may still be increased in those with an early onset. Therefore, biological factors, such as sex and age onset, appear to be relevant to the physiology of rapid cycling. The retrospective design and the selected population of bipolar-I patients from an academic tertiary-referral center may limit the generalizability of our results.

Adolescent↗
PubMed2002

Comprehensive testing of 10 different ankle braces. Evaluation of passive and rapidly induced stability in subjects with chronic ankle instability.

OBJECTIVE: The aim of the present investigation was to test the stability of 10 different ankle braces under passive and rapidly induced loading conditions in a population suffering from chronic ankle instability in order to provide objective information to choose or recommend an appropriate model for specific needs. In addition, the relationship between passive and rapidly induced testing of the stabilizing effect against inversion was evaluated to identify if passive support characteristics of braces are reflected under rapidly induced conditions. DESIGN: An experimental in vivo study with a repeated-measures design was used. BACKGROUND: Ankle braces are commonly used for treatment, rehabilitation, and prevention of ankle injuries. A variety of products exists but there is few information available to assist clinicians, physiotherapists and coaches as well as consumers in choosing a brace on a basis of objective information. Furthermore, there is a lack of studies that provide data for both passively and rapidly induced movement of the ankle joint when using different ankle braces. METHODS: Twenty-four subjects with chronic ankle instability participated in the project. Passive ankle range of motion measurements were performed in a custom-built fixture and simulated inversion sprains were elicited on a tilting platform. RESULTS: The tested braces restrict range of motion significantly compared to the no-brace condition for both the passively and rapidly induced inversion and marked differences between braces were revealed. A close relationship between passive and rapidly induced test results for inversion was found. CONCLUSIONS: Passive as well as rapidly induced stability tests provide a basis of objective information to describe the characteristics of different ankle braces. Combined results of passive and rapidly induced inversion as well as correlation between results demonstrate that passive support characteristics of braces are reflected under rapidly induced conditions but the amount of restriction is reduced. Therefore, caution should be taken when recommending braces for applications under dynamic circumstances only on the basis of passive support characteristics. RELEVANCE: A basis of information regarding the stability characteristics of different ankle braces under passive and rapidly induced conditions will help the clinician and consumer in choosing the most appropriate brace model for specific use. The results also provide more insights into factors that influence stability characteristics of ankle braces.

Adult↗
PubMed2002

A novel role of pedunculopontine tegmental kainate receptors: a mechanism of rapid eye movement sleep generation in the rat.

Considerable evidence suggests that pedunculopontine tegmental cholinergic cells are critically involved in normal regulation of rapid eye movement sleep. The major excitatory input to the cholinergic cell compartment of the pedunculopontine tegmentum arises from glutamatergic neurons in the pontine reticular formation. Immunohistochemical studies reveal that both ionotropic and metabotropic receptors are expressed in pedunculopontine tegmental cells. This study aimed to identify the role of endogenous glutamate and its specific receptors in the pedunculopontine tegmentum in the regulation of physiological rapid eye movement sleep. To identify this physiological rapid eye movement sleep-inducing glutamate receptor(s) in the pedunculopontine tegmental cholinergic cell compartment, specific receptors were blocked differentially by local microinjection of selective glutamate receptor antagonists into the pedunculopontine tegmental cholinergic cell compartment while quantifying the effects on rapid eye movement sleep in freely moving chronically instrumented rats. By comparing the alterations in the patterns of rapid eye movement sleep following injections of control vehicle and selective glutamate receptor antagonists, contributions made by each receptor subtype in rapid eye movement sleep were evaluated. The results demonstrate that when kainate receptors were blocked by local microinjection of a kainate receptor selective antagonist, spontaneous rapid eye movement sleep was completely absent for the first 2 h, and for the next 2 h the total percentage of rapid eye movement sleep was significantly less compared to the control values. In contrast, when N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid, groups I, II, and III metabotropic receptors were blocked, total percentages of rapid eye movement sleep did not change compared to the control values. These findings suggest, for the first time, that the activation of kainate receptors within the cholinergic cell compartment of the pedunculopontine tegmentum is a critical step for the regulation of normal rapid eye movement sleep in the freely moving rat. The results also suggest that the different types of glutamate receptors within a small part of the brainstem may be involved in different types of physiological functions.

Acetylcholine↗
PubMedDate not supplied

Characterization of the Phenomenon of rapid tolerance to ethanol.

Motor impairment (tilt-plane) and hypothermia tests were used to further characterize the phenomenon of rapid tolerance to ethanol. Five experiments were carried out to clarify the relationship between rapid and chronic tolerance. The first experiment demonstrated that the extent of tolerance on day 2 produced by the single dose of 4 g/kg alcohol on day 1 was similar to that resulting from two divided doses, administered 2 h apart. In the second experiment, a linear relationship between treatment dose and rapid tolerance development was demonstrated in that higher day 1 treatment doses resulted in greater rapid tolerance development. In the third, a parallel dose-response relationship, similar to that known for chronic tolerance, was observed for rapid tolerance. In the fourth experiment, we compared the development of rapid tolerance under three different conditions: (a) in groups of rats that were not subjected to testing at all (no testing); on day 1, (b) in groups of rats that were not tested on the apparatus but handled at all test times on day 1 (dummy testing); and (c) in groups of rats that were tested at all test times on day 1 (testing or intoxicated group). No testing on day 1 failed to produce rapid tolerance to ethanol whereas testing and dummy testing of animals on day 1 after pretreatment with ethanol-produced rapid tolerance to ethanol on day 2. In the last experiment, immediate posttrial administration of ketamine was found not to block rapid tolerance development. These findings provide additional support for similarities between the mechanisms of rapid and chronic tolerance.

Animals↗
PubMed1998

Rapid improvement teams.

BACKGROUND: Suggestions, most of which are supported by empirical studies, are provided on how total quality management (TQM) teams can be used to bring about faster organizationwide improvements. SUGGESTIONS: Ideas are offered on how to identify the right problem, have rapid meetings, plan rapidly, collect data rapidly, and make rapid whole-system changes. Suggestions for identifying the right problem include (1) postpone benchmarking when problems are obvious, (2) define the problem in terms of customer experience so as not to blame employees nor embed a solution in the problem statement, (3) communicate with the rest of the organization from the start, (4) state the problem from different perspectives, and (5) break large problems into smaller units. Suggestions for having rapid meetings include (1) choose a nonparticipating facilitator to expedite meetings, (2) meet with each team member before the team meeting, (3) postpone evaluation of ideas, and (4) rethink conclusions of a meeting before acting on them. Suggestions for rapid planning include reducing time spent on flowcharting by focusing on the future, not the present. Suggestions for rapid data collection include (1) sample patients for surveys, (2) rely on numerical estimates by process owners, and (3) plan for rapid data collection. Suggestions for rapid organizationwide implementation include (1) change membership on cross-functional teams, (2) get outside perspectives, (3) use unfolding storyboards, and (4) go beyond self-interest to motivate lasting change in the organization. CONCLUSIONS: Additional empirical investigations of time saved as a consequence of the strategies provided are needed. If organizations solve their problems rapidly, fewer unresolved problems may remain.

Benchmarking↗
PubMed1998

The sensitivity of rapid (partial) review of cervical smears.

Rapid review involves a daily rapid (e.g. 30 s) review of all smears not normally double-screened. It has been suggested that the method may increase the sensitivity of cervical cytology by identifying abnormalities not reported on initial screening, true false negatives (TFN). Rapid screening is reported to have high sensitivity for cervical neoplasia when used as a preview tool. To be effective, however, in a review mode it must be able to detect TFN. Several studies have found that many TFN result from factors such as low numbers of abnormal cells or subtle expression of diagnostic criteria. Studies on the sensitivity of rapid screening for detecting TFN would therefore provide a more reliable estimate of its value as a review tool. The sensitivity of rapid re-screening was evaluated using a test set of 200 cases. Each of 15 screeners rapidly reviewed (30 s partial screen) the set over a 2-week period. The set consisted of 129 normal, 28 low-grade squamous lesions (CIN I), 37 high-grade lesions (CIN II, III and adenocarcinoma in situ (AIS)) and six invasive carcinomas. The abnormals included 20 TFN cases. The median sensitivity for abnormalities was 62%. Rapid review was more sensitive for CIN II and CIN III (67%) and invasive carcinoma (66.7%) than for CIN I (53%). Great variation was apparent in the sensitivity for individual screeners, with a range of 41-86% for all abnormalities. The sensitivity for TFN cases varied even more (10-75%, median 35%) and for most screeners was significantly (P < 0.05) lower than for cases which were detected on initial screen (53-90%, median 70.6%). Following this trial rapid review was used routinely for a period of 3 months. In this time 11,413 cases were rapidly reviewed. This led to the full review of 415 slides (3.5%) and the identification of 16 cases of undetected CIN (12 CIN I, three CIN II, one CIN III). Based on current estimates of our laboratory false-negative rate this represents between a quarter and half of the TFN cases of CIN that probably occurred in this period. In conclusion, rapid screening is likely to be significantly less sensitive when used in a review rather than a preview mode. In routine practice the method requires a daily commitment of screener time, but does provide a higher yield of TFN smears than does random review, and allows amendment of these results prior to reporting.

Diagnostic Errors↗
PubMed1999

Parathyroid hormone is not a key hormone in the rapid minute-to-minute regulation of plasma Ca2+ homeostasis in rats.

BACKGROUND: The role of parathyroid hormone (PTH) in the rapid minute-to-minute regulation of plasma Ca2+ (p-Ca2+) was studied in vivo in rats. MATERIALS AND METHODS: The rapid calcaemic response to exogenous rat PTH1-34 (16 microg) was examined in normal rats, and the long-term calcaemic response was examined in parathyroidectomized (PTX) rats receiving PTH1-34 for 24 h at 0.2, 0. 4 and 0.8 microg h-1. Acute hypocalcaemia was induced by EGTA for 30 min, and then the rapid recovery of p-Ca2+ was studied for 130 min in normal rats, 24 h after PTX and in PTX rats infused with exogenous rat PTH1-34. The dynamics of the rapid recovery of p-Ca2+ was studied at two additional doses of EGTA. RESULTS: No rapid calcaemic response was observed in the first 60 min after administration of PTH and no hypocalcaemia was seen for 2 h after acute PTX. This slow effect of PTH suggests that PTH might not be responsible for maintaining the stable p-Ca2+ on a rapid minute-to-minute basis. EGTA induced acute hypocalcaemia in both normal and PTX rats (P < 0.01). In both groups a rapid and similar increase in p-Ca2+ took place 10 min after discontinuing EGTA (P < 0. 05). Within 60 min, p-Ca2+ increased further, independently of the presence of PTH. Infusion of PTH to PTX rats did not affect the rapid recovery of p-Ca2+ (P < 0.05) from EGTA induced hypocalcaemia. CONCLUSION: PTH is not a key hormone in the rapid recovery of p-Ca2+ after induction of hypocalcaemia, but might, however, set the long-term levels of p-Ca2+ maintained by mammalian organisms. The involvement of an as yet unknown factor in the rapid regulation of p-Ca2+ is suggested.

Animals↗
PubMed1996

Restenosis after coronary angioplasty for rapidly progressive coronary stenosis.

OBJECTIVES: We hypothesized that percutaneous transluminal coronary angioplasty performed on coronary stenoses that have demonstrated rapid angiographic progression would be associated with a high risk of restenosis. BACKGROUND: High rates of restenosis have been documented after percutaneous transluminal coronary angioplasty of unstable lesions and of lesions that recur rapidly after a successful initial angioplasty. This suggests that the "activity' of the plaque at the time of angioplasty may be an important factor determining the risk of restenosis. METHODS: In our institution we recommend angiographic follow-up for all patients with successful percutaneous transluminal coronary angioplasty. In this way we identified 86 consecutive patients who, at the time of angiographic follow-up had not developed restenosis at the dilated site, but required a further percutaneous transluminal coronary angioplasty at a different site. (which was successful). Based on quantitative angiographic measurements, 45 of these lesions (rapidly progressive lesions) had significantly increased in severity in the interval between the two angiograms (7.7 +/- 3.3 months) while 41 (stable lesions) had not. Rapid progression was defined as a > 0.4 mm decrease in minimal lumen diameter between initial angiography and percutaneous transluminal coronary angioplasty. All 86 patients had further angiographic follow-up 6 months later. RESULTS: Baseline clinical and angiographic variables were similar in both groups except that a higher proportion of patients in the rapid progression group had unstable angina (20% vs 5%; P < 0.05). Late loss during follow-up did not differ statistically between groups (0.31 mm) and minimal lumen diameter at follow-up was also similar (stable lesion group = 1.40 +/- 0.48 mm; rapidly progressive lesion group = 1.30 +/- 0.59 mm). The loss index (late loss divided by acute gain) was also similar in both groups (0.45 +/- 0.52 in the stable lesion group, 0.37 +/- 0.76 in the rapidly progressive lesion group). A strong correlation between acute gain and late loss was observed in the stable lesion group (r = 0.61; P < 0.0001); by contrast, there was no relationship between these two variables in the rapidly progressive lesion group (r = 0.20; P = 0.19). CONCLUSIONS: Percutaneous transluminal coronary angioplasty in patients with unstable angina or with early recurrence after a first percutaneous transluminal coronary angioplasty is associated with an increased risk of restenosis. By contrast, this study shows that angiographic instability, as evidenced by rapid stenosis progression, has no deleterious effect on the occurrence of restenosis. Percutaneous transluminal coronary angioplasty thus appears as a reasonable therapeutic option for coronary stenoses that have demonstrated rapid angiographic progression in the months prior to the procedure.

Age Factors↗
PubMed1994

Clinical impact of rapid in vitro susceptibility testing and bacterial identification.

During the past decade, a variety of instrument-assisted bacterial identification and antimicrobial susceptibility test systems have been developed which permit provision of test results in a matter of hours rather than days, as has been the case with traditional overnight procedures. These newer rapid techniques are much more expensive than older methods. It has been presumed but not proven that the clinical benefits of rapid testing to patients with infection offset the added cost. The intent of this study was to objectively define the clinical impact of rapid bacterial identification and antimicrobial susceptibility testing. A 1-year study was performed in which infected, hospitalized patients in a tertiary-care, teaching, medical center were randomly assigned to one of two groups: patients for whom identification and susceptibility testing was performed by using a semi-automated, rapid, same-day procedure and those for whom testing was accomplished by using traditional overnight techniques. The two groups were compared with respect to numerous demographic descriptors, and then patients were monitored prospectively through the end of their hospitalization with the aim of determining whether there existed objectively defineable differences in management and outcome between the two groups. The mean lengths of time to provision of susceptibility and identification test results in the rapid test group were 11.3 and 9.6 h, respectively. In the overnight test group, these values were 19.6 and 25.9 h, respectively (P < 0.0005). There were 273 evaluable patients in the first group and 300 in the second group. Other than the length of time required to provide susceptibility and identification test results, no significant differences were noted between the two groups with respect to > 100 demographic descriptors. With regard to measures of outcome, the mean lengths of hospitalization were also the same in both groups. Mortality rates were however, lower in the rapid test group (i.e., 8.8% versus 15.3%). Similarly, statistically significantly fewer laboratory studies, imaging procedures, days of intubation, and days in an intensive or intermediate-care area were observed with patients in the rapid test group. Rapid testing was also associated with significantly shortened lengths of elapsed time prior to alterations in antimicrobial therapy. Lastly, patient costs for hospitalization were significantly lower in the rapid test group. The results of this study indicate the rapid same-day bacterial identification and susceptibility testing in the microbiology laboratory can have a major impact on the care and outcome of hospitalized patients with infection.

Adolescent↗
PubMed2005

Rapid estrogenic regulation of extracellular signal- regulated kinase 1/2 signaling in cerebellar granule cells involves a G protein- and protein kinase A-dependent mechanism and intracellular activation of protein phosphatase 2A.

In neonatal rat cerebellar neurons, 17beta-estradiol (E(2)) rapidly stimulates ERK1/2 phosphorylation through a membrane-associated receptor. Here the mechanism of rapid E(2)-induced ERK1/2 signaling in primary cultured granule cells was investigated in more detail. The results of these studies show that E(2) and ICI182,780, a steroidal antagonist of estrogen receptor transactivation, rapidly increased ERK signaling with a time course similar to the transient activation induced by epidermal growth factor (EGF). However, EGF receptor (EGFR) autophosphorylation was not increased by E(2), and blockade of EGFR tyrosine kinase activity did not abrogate the rapid actions of E(2). The involvement of Src-tyrosine kinase activity was demonstrated by detection of increased c-Src phosphorylation in response to E(2) and by blockade of E(2)-induced ERK1/2 activation by inhibition of Src-family tyrosine kinase activity. Inhibition of Galphai signaling or protein kinase A (PKA) activity blocked the ability of ICI182,780 to rapidly stimulate ERK signaling. Under those conditions, E(2) treatment induced a rapid and transient suppression of basal ERK1/2 phosphorylation. Protein phosphatase 2A (PP2A) activity was rapidly increased by E(2) but not by E(2) covalently linked to BSA. Rapid E(2)-induced increases in PP2A activity were insensitive to pertussis toxin. The presented evidence indicates that the rapid effects of estrogens on ERK signaling in cerebellar granule cells are induced through a novel G protein-coupled receptor mechanism that requires PKA and Src-kinase activity to link E(2) to the ERK/MAPK signaling module. Along with stimulating ERK signaling, E(2) rapidly activates PP2A via an independent signaling mechanism that may serve as a cell-specific regulator of signal duration.

Animals↗
PubMedDate not supplied

The media of rapid urease test influence the diagnosis of Helicobacter pylori.

BACKGROUND/AIMS: The influence of different media on the validity of the rapid urease test, including accuracy, reaction time and cost-effectiveness is evaluated. METHODOLOGY: Biopsies were obtained from the antral and body mucosa of 100 KMUH patients (51 men, 49 women; mean age: 54.0 years, range: 21-79 years old) undergoing gastroendoscopy due to dyspepsia. None of the patients had received any Helicobacter pylori eradicating treatment, nor any other antibiotic or bismuth treatment in the previous one month, nor had they had any type of gastric operation in the past. Helicobacter pylori status was evaluated by seven different tests: culture, histology, home-made rapid urease test, 13C-urea breath test, and three different commercially available rapid urease tests--including the CLO test, the ProntoDry test, and the Pyloriset Urease test. Helicobacter pylori status was defined as positive when the culture was positive or if concordance of two of the other three tests (histology, homemade rapid urease test and 13C-urea breath test) was positive. RESULTS: Three different rapid urease tests have similar sensitivities (97.3% vs. 100% vs. 100%) and specificities (98.4% vs. 96.8% vs. 98.2%), and accuracy (98.4% vs. 96.8% vs. 98.2%). But the reaction time was longer in the CLO test than for the other two rapid urease tests (22.3 vs. 5.6 vs. 10.1 minutes) (P < 0.05). The ProntoDry test and the Pyloriset Urease test also have more rapid positive rate than CLO test. However, in vitro study, three tests show similar rapidity of positive reaction at different densities of Helicobacter pylori. CONCLUSIONS: These three tests have practical advantages for physicians who need a rapid and accurate method of diagnosing Helicobacter pylori infections. The ProntoDry test and Pyloriset Urease test have degrees of accuracy similar to the CLO test, but results are obtained more rapidly and they are cheaper. Furthermore, The ProntoDry test can be stored at room temperature and thereby save on the storage expense.

Adult↗
PubMed1991

Rapid blood clearance of immunoglobulin G2a and immunoglobulin G2b in nude mice.

An extremely rapid blood clearance rate of murine IgG2a antibodies was found in all strains tested of outbred Swiss nu/nu mice, including mice from the major commercial suppliers. The clearance half-life was less than 5 h, in comparison to a 4-5-day half-life in BALB/c mice. Therefore, most of the IgG2a antibody injected i.v. in such mice is cleared before it can reach interstitial fluid, which interferes with immunotherapy and immunodetection experiments. Individual nude mice varied greatly in their IgG2a clearance rates, which hampered investigation of the phenomena. In our experience, approximately three-fourths of nude mice had a rapid or intermediate clearance rate, whereas the remainder had an approximately normal clearance rate. The clearance rate in nude mice was age-dependent, at least in some instances, in that a rapid clearance rate was observed at 2 months of age, whereas the same mice retested at 4 months of age had a normal clearance rate. Rapid clearance could be inhibited by increasing the dose injected: 100 micrograms/mouse resulted in a normal clearance rate, whereas 30 micrograms/mouse was insufficient to inhibit rapid clearance. The clearance rate of IgG2b antibodies was affected similarly to that of IgG2a, whereas the clearance rate of IgG1 and IgG3 was not affected. The Fc region of IgG2a was required in order for rapid clearance to occur. Biodistribution experiments demonstrated that rapid blood clearance was due, at least partially, to binding to the liver and spleen. To determine the genetic basis for rapid IgG2a clearance, approximately 20 inbred and outbred mouse strains were tested. Unexpectedly, nu/+ as well as nu/nu outbred Swiss mice displayed rapid clearance, whereas control +/+ mice did not, so this phenotype appears to be a dominant effect of the nu mutation. BALB/c nu/nu and nu/+ mice did not display rapid clearance, which may be due to expression of the Igh-1a gene, which codes for the IgG2a present in BALB/c mice and in the monoclonal antibodies used in these studies. In conclusion, this clearance effect must be considered in experiments involving murine IgG2a or IgG2b antibodies in outbred Swiss nude mice, except those in which high antibody doses of greater than 0.1 mg/mouse are used. One method of circumventing this problem is to increase the antibody dose injected; a better but more long-range method is to develop strains of outbred nude mice that do have this characteristic.

Animals↗
PubMed1995

Evaluation of a rapid bedside assay for detection of serum cardiac troponin T.

OBJECTIVE: To evaluate a rapid, qualitative, bedside immunoassay for cardiac-specific troponin T (cTnT) using a handheld device containing monoclonal antibodies. DESIGN: Comparison of rapid cTnT assay with clinical standard for diagnosis of myocardial infarction (MI). SETTING: Tertiary care university medical center. PATIENTS: A cohort of 100 patients admitted for evaluation of chest pain who had sufficient blood samples at presentation for measurement of creatine kinase, creatine kinase MB fraction, and rapid cTnT as well as adequate clinical data to establish the diagnosis of MI. INTERVENTION: None; treating physicians were blinded to rapid cTnT results. MAIN OUTCOME MEASURES: Sensitivity and specificity of rapid cTnT assay for MI; likelihood ratios of positive and negative rapid cTnT assay results; relative risk (RR) for serious cardiac events with positive rapid cTnT assay result on admission. RESULTS: Sensitivity of the rapid cTnT assay increased from 33% within 2 hours from the onset of chest pain to 86% after 8 hours (P < .001); specificity ranged from 86% to 100% during the same time intervals. The odds of an MI increased sixfold with a positive assay result within 2 hours of chest pain and decreased sixfold with a negative assay result after 8 hours. The RR for experiencing death or nonfatal MI was 6.8 for patients presenting with a positive rapid cTnT assay. CONCLUSIONS: The rapid cTnT assay is a simple, efficient test that for the first time provides clinicians with a useful laboratory tool for point-of-care evaluation of patients with chest pain.

Biomarkers↗
PubMed1994

Rapid metabolic phenotypes for acetyltransferase and cytochrome P4501A2 and putative exposure to food-borne heterocyclic amines increase the risk for colorectal cancer or polyps.

The metabolic activation of food-borne heterocyclic amines to colon carcinogens in humans is hypothesized to occur via N-oxidation followed by O-acetylation to form the N-acetoxy arylamine that binds to DNA to give carcinogen-DNA adducts. These steps are catalyzed by hepatic cytochrome P4501A2 (CYP1A2) and acetyltransferase-2 (NAT-2), respectively, which are known to be polymorphic in humans. On the basis of this proposed metabolic activation pathway, patients at greatest risk to develop colorectal cancer or nonfamilial polyps should be those who possess both the rapid NAT-2 and rapid CYP1A2 phenotypes and are exposed to high dietary levels of carcinogenic heterocyclic amines. Using a method that involves caffeine administration and high pressure liquid chromatographic analysis of urinary metabolites, we have determined the CYP1A2 and NAT-2 phenotypes of 205 controls and 75 cancer/polyp cases. Exposure information was obtained using a dietary and health habits questionnaire. Both the rapid CYP1A2 and rapid NAT2 phenotypes were each slightly more prevalent in cases versus controls (57% and 52% versus 41% and 45%, respectively). However, the combined rapid CYP1A2-rapid NAT-2 phenotype was found in 35% of cases and only 16% of the controls, giving an odds ratio of 2.79 (P = 0.002). Univariate analysis of the questionnaire indicated that age, rapid-rapid phenotype, and consumption of well done red meat were associated with increased risk of colorectal neoplasia. Furthermore, a logistic regression model that included age (as a continuous variable), consumption of well done red meat, and rapid-rapid phenotype as independent covariates gave odds ratios of 1.08, 2.08, and 2.91, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetyltransferases↗
PubMed2004

Rapid HIV-1 testing during labor: a multicenter study.

CONTEXT: Timely testing of women in labor with undocumented human immunodeficiency virus (HIV) status could enable immediate provision of antiretroviral prophylaxis. OBJECTIVES: To determine the feasibility and acceptance of rapid HIV testing among women in labor and to assess rapid HIV assay performance. DESIGN, SETTING, AND PATIENTS: The Mother-Infant Rapid Intervention At Delivery (MIRIAD) study implemented 24-hour counseling and voluntary rapid HIV testing for women in labor at 16 US hospitals from November 16, 2001, through November 15, 2003. A rapid HIV-1 antibody test for whole blood was used. MAIN OUTCOME MEASURES: Acceptance of HIV testing; sensitivity, specificity, and predictive value of the rapid test; time from blood collection to patient notification of results. RESULTS: There were 91,707 visits to the labor and delivery units in the study, 7381 of which were by eligible women without documentation of HIV testing. Of these, 5744 (78%) women were approached for rapid HIV testing and 4849 (84%) consented. HIV-1 test results were positive for 34 women (prevalence = 7/1000). Sensitivity and specificity of the rapid test were 100% and 99.9%, respectively; positive predictive value was 90% compared with 76% for enzyme immunoassay (EIA). Factors independently associated with higher test acceptance included younger age, being black or Hispanic, gestational age less than 32 weeks, and having had no prenatal care. Lower acceptance was associated with being admitted between 4 pm and midnight, particularly on Friday nights, but this may be explained in part by fewer available personnel. Median time from blood collection to patient notification of result was 66 minutes (interquartile range, 45-120 minutes), compared with 28 hours for EIA (P<.001). CONCLUSIONS: Rapid HIV testing is feasible and delivers accurate and timely test results for women in labor. It provides HIV-positive women prompt access to intrapartum and neonatal antiretroviral prophylaxis, proven to reduce perinatal HIV transmission, and may be particularly applicable to higher-risk populations.

AIDS Serodiagnosis↗
PubMed2006

Accuracy and impact of a point-of-care rapid influenza test in young children with respiratory illnesses.

OBJECTIVE: To determine whether a point-of-care rapid influenza test impacts the diagnostic evaluation and treatment of children with acute respiratory illnesses. DESIGN: Randomized controlled trial. SETTING: Pediatric emergency department and acute care clinic of a children's hospital. PARTICIPANTS: Children aged younger than 5 years with fever or acute respiratory symptoms during 2 influenza seasons (2002 through 2004). INTERVENTIONS: Surveillance days were randomized to performance or no performance of a point-of-care rapid influenza test. All children had a nasal and throat swab obtained for laboratory tests. The rapid test group had another nasal swab obtained for the QuickVue Influenza Test (Quidel Corp, San Diego, Calif), which was performed by nurses; results were shared immediately with treating physicians. MAIN OUTCOME MEASURES: Rapid test results were compared with results of the viral culture or 2 polymerase chain reaction assays for influenza. Diagnostic test ordering and antibiotic prescribing were compared for the groups. RESULTS: Of 468 enrolled children, 306 were from the emergency department and 162 from the clinic. Overall, 88 children (19%) had influenza infection. Of 205 children in the rapid test group, 51 (25%) had influenza infection. The rapid influenza test was 82% sensitive and 99% specific. In the emergency department, fewer children in the rapid test group had diagnostic tests ordered than in the no rapid test group (39% vs 51%, P = .03). There was no difference in test ordering in the clinic or in antibiotic prescribing in either setting. The use of antivirals was low. CONCLUSIONS: Point-of-care rapid influenza tests were sensitive and specific and were associated with less diagnostic testing in the emergency department.

Child↗
PubMed2003

Rapid magnetic resonance imaging vs radiographs for patients with low back pain: a randomized controlled trial.

CONTEXT: Faster magnetic resonance imaging (MRI) scanning has made MRI a potential cost-effective replacement for radiographs for patients with low back pain. However, whether rapid MRI scanning results in better patient outcomes than radiographic evaluation or a cost-effective alternative is unknown. OBJECTIVE: To determine the clinical and economic consequences of replacing spine radiographs with rapid MRI for primary care patients. DESIGN, SETTING, AND PATIENTS: Randomized controlled trial of 380 patients aged 18 years or older whose primary physicians had ordered that their low back pain be evaluated by radiographs. The patients were recruited between November 1998 and June 2000 from 1 of 4 imaging centers in the Seattle, Wash, area: a university-based teaching program, a nonuniversity-based teaching program, and 2 private clinics. INTERVENTION: Patients were randomly assigned to receive lumbar spine evaluation by rapid MRI or by radiograph. MAIN OUTCOME MEASURES: Back-related disability measured by the modified Roland questionnaire. Secondary outcomes included Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), pain, preference scores, satisfaction, and costs. RESULTS: At 12 months, primary outcomes of functional disability were obtained from 337 (89%) of the 380 patients enrolled. The mean back-related disability modified Roland score for the 170 patients assigned to the radiograph evaluation group was 8.75 vs 9.34 for the 167 patients assigned the rapid MRI evaluation group (mean difference, -0.59; 95% CI, -1.69 to 0.87). The mean differences in the secondary outcomes were not statistically significant : pain bothersomeness (0.07; 95% CI -0.88 to 1.22), pain frequency (0.12; 95% CI, -0.69 to 1.37), and SF-36 subscales of bodily pain (1.25; 95% CI, -4.46 to 4.96), and physical functioning (2.73, 95% CI -4.09 to 6.22). Ten patients in the rapid MRI group vs 4 in the radiograph group had lumbar spine operations (risk difference, 0.34; 95% CI, -0.06 to 0.73). The rapid MRI strategy had a mean cost of 2380 dollars vs 2059 dollars for the radiograph strategy (mean difference, 321 dollars; 95% CI, -1100 to 458). CONCLUSIONS: Rapid MRIs and radiographs resulted in nearly identical outcomes for primary care patients with low back pain. Although physicians and patients preferred the rapid MRI, substituting rapid MRI for radiographic evaluations in the primary care setting may offer little additional benefit to patients, and it may increase the costs of care because of the increased number of spine operations that patients are likely to undergo.

Activities of Daily Living↗
PubMed2005

The role of tropomyosin-related kinase receptors in neurotrophin-induced rapid eye movement sleep in the cat.

The microinjection of nerve growth factor and neurotrophin-3 into the rostro-dorsal pontine tegmentum of the cat evokes a state that is comparable to naturally-occurring rapid eye movement sleep. Using two experimental paradigms, we tested the hypothesis that neurotrophin high-affinity receptors (trkA and trkC, tropomyosin-related kinase A and C, respectively) mediate this effect. First, trk and fos immunohistochemistry were combined to determine whether tyrosine kinase receptor-containing neurons in the dorsal pontine tegmentum are active in cats that exhibit long-lasting periods of rapid eye movement sleep following the local microinjection of nerve growth factor. During approximately two hours of recording, nerve growth factor-treated cats spent 59.8% of the time in a rapid eye movement sleep-like state; vehicle-injected (control) animals remained in quiet wakefulness and non-rapid eye movement sleep. Whereas control and nerve growth factor-treated cats exhibited a similar mean number of trkA- and trkC-immunoreactive neurons in the dorsal pontine tegmentum, the number of trkA- and trkC-immunoreactive neurons that expressed Fos, i.e. double-labeled cells that are presumably activated, was significantly larger in cats that were injected with nerve growth factor. Axon terminals contained tyrosine kinase receptor immunoreactivity in this region; many were apposed to Fos-immunoreactive neurons. In addition, patterns of tyrosine kinase receptor and Fos immunoreactivity similar to those observed in nerve growth factor-injected cats were present, in conjunction with long-lasting rapid eye movement sleep, following the microinjection of carbachol into the dorsal pons. In a second series of studies, nerve growth factor or neurotrophin-3 was injected alone or after K-252a, a blocker of tyrosine kinase receptors, into the rostro-dorsal pontine tegmentum. Nerve growth factor or neurotrophin-3 alone produced, with a mean latency of 4 min, a rapid eye movement sleep-like state. However, neurotrophin injections preceded by K-252a were not effective in inducing rapid eye movement sleep. These results indicate that the activation of trkA and trkC receptors in neurons in the pontine tegmentum is responsible, at least in part, for the rapid eye movement sleep-inducing effect of nerve growth factor and neurotrophin-3. Furthermore, the data suggest that these neurotrophins are capable of acting both pre- and postsynaptically to activate pontine neurons that are involved in the generation of rapid eye movement sleep.

Analgesics, Non-Narcotic↗