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At least 19 recordsLinked to original sources
PubMed2006

Ovarian reserve tests for predicting fertility outcomes for assisted reproductive technology: the International Systematic Collaboration of Ovarian Reserve Evaluation protocol for a systematic review of ovarian reserve test accuracy.

BACKGROUND: The presence of a wide range of tests of ovarian reserve suggests that no single test provides a sufficiently accurate result. Many tests are used without reference to an evidence base. So far, individual studies conducted on these tests are too small to give precise estimates of prognostic accuracy. OBJECTIVES: To systematically assess the accuracy of the available tests of ovarian reserve in terms of prediction of fertility outcomes. SEARCH STRATEGY: The search will be conducted using the name of the respective index test being studied (as listed on the MESH database), if more than 2000 citations are listed, 'ovary' and or 'ovarian', 'fertility' and or 'reserve' will be combined with the original search term as required. Studies of the accuracy of tests of ovarian reserve will be obtained without language restrictions from 1980 to 2005 using the following electronic databases and Ovid software: MEDLINE, EMBASE, PUBmed, Biological extracts, Pascal, Cochrane Library (CDSR, DARE, CCTR, HTA), Best Evidence databases, SCISEARCH, Conference Proceedings (ISI Proceedings, Healthstar, Current Contents, Science Citation Index, Cancerlit and Econlit and NHS Economic Evaluation database. The National Research Register, the Medical Research Council's Clinical Trials Register, MEDION, DARE, and the US Clinical Trials register. SELECTION CRITERIA: Studies will be selected if accuracy of tests are compared with a reference standard and include data that can be abstracted into a two-by-two table to calculate sensitivity and specificity. The studies to be included in this review will examine one of the following index 'tests' within a study population of women undergoing assisted reproductive technology: * Clinical variables--age, history of cancelled cycles. * Basal blood tests--follicle-stimulating hormone (FSH), lutenising hormone (LH), FSH:LH ratios, estradiol (E(2)), inhibin A and B, progesterone (P(4)), P(4):E(2) ratios, antimullerian hormone, testosterone, vascular endothelial growth factor, insulin-like growth factor-1:insulin-like growth factor binding protein-1 ratios. * Dynamic tests--clomiphene citrate challenge test, gonadotropin analogue stimulating test, exogenous FSH ovarian reserve test. * Ultrasound tests-antral follicle count, ovarian volume, ovarian stromal peak systolic velocity, including waveform and pulsatility index, ovarian follicular vascularity. * Histology--ovarian biopsy. Data collection and analysis Two independent reviewers will perform quality assessment and data extraction. Prognostic accuracy will be determined by calculating positive and negative likelihood ratios for the following outcomes or reference standards: live birth, ongoing pregnancy, clinical pregnancy, biochemical pregnancy, embryos available for transfer, eggs obtained at oocyte retrieval, cycles cancelled prior to oocyte retrieval. Main results and conclusions N/A.

Data Collection↗
PubMed2005

Civilian Health and Medical Program of the Uniformed Services (CHAMPUS); TRICARE Reserve Select for certain members of the selected reserve; Transitional Assistance Management Program; early eligibility for TRICARE for certain reserve component members. Interim final rule with comment period.

This interim final rule establishes requirements and procedures for implementation of TRICARE Reserve Select. It also revises requirements and procedures for the Transitional Assistance Management Program. In addition, it establishes requirements and procedures for implementation of the earlier TRICARE eligibility for certain reserve component members. The rule is being published as an interim final rule with comment period in order to comply with statutory effective dates.

Eligibility Determination↗
PubMed1995

Comparison between regional myocardial perfusion reserve and coronary flow reserve in the canine heart.

Diameter stenosis and flow reserve are indices of morphological and functional severity of coronary artery stenosis. Flow reserve can be determined at coronary arterial or at myocardial level. In the presence of functional collateral circulation, coronary flow reserve and myocardial perfusion reserve may differ. We studied coronary flow, coronary flow reserve and myocardial perfusion reserve in an open chest dog model with intact collateral circulation, before and after induction of coronary artery stenosis. Coronary flow was determined with perivascular ultrasonic flow probes and myocardial perfusion reserve from digital angiographic images, in the stenotic as well as the adjacent non-stenotic coronary arteries. Before induction of a stenosis, a significant correlation existed between coronary flow reserve and myocardial perfusion reserve of the left anterior descending (r = 0.59; P < 0.005) and the left circumflex arteries (r = 0.84, P < 0.005). In stenotic arteries, coronary flow reserve and myocardial perfusion reserve decreased significantly (P < 0.005), but in the adjacent non-stenotic arteries coronary flow reserve was not affected. Myocardial perfusion reserve in the non-stenotic adjacent left anterior descending artery decreased significantly (P < 0.05) and no correlation was found between coronary flow reserve and myocardial perfusion reserve, whereas in the adjacent non-stenotic left circumflex artery there was no statistically significant decrease (4.1 +/- 1.6 --> 3.5 +/- 1.4) but there was a good correlation between coronary flow reserve and myocardial perfusion reserve (r = 0.85; P < 0.005). This study demonstrates that, in the presence of a stenosis and functioning collateral circulation, coronary flow reserve is not a reliable predictor of myocardial perfusion reserve; both parameters provide mutually complementary information.

Angiography, Digital Subtraction↗
PubMed2000

Diastolic fractional flow reserve to assess the functional severity of moderate coronary artery stenoses: comparison with fractional flow reserve and coronary flow velocity reserve.

BACKGROUND: Coronary blood flow occurs mainly during the diastolic phase of each cardiac cycle and is mainly dependent on diastolic driving pressure, especially in the left anterior descending coronary artery (LAD). We hypothesized that calculation of the ratio of the diastolic driving pressure of a stenotic LAD to its normal value, namely diastolic FFR (d-FFR), might provide precise insight into the mechanism of FFR for assessment of the functional severity of the stenosis. We compared d-FFR with FFR, coronary flow reserve (CFR), and exercise myocardial thallium scintigraphy in an lesion of intermediate severity. METHODS AND RESULTS: The study population consisted of 46 consecutive patients with a moderate stenosis in the LAD in whom simultaneous measurements of aortic pressure, left ventricular pressure, and coronary pressure distal to the stenosis were obtained. Coronary flow velocity was successfully measured with a Doppler guidewire in 37 of the 46 patients. Values for FFR, d-FFR, and CFR in the noninvasive test-positive group were significantly lower than those in the negative group. With cutoff values of 0.75, 0.76, and 2.0 for FFR, d-FFR, and CFR, sensitivities were 83.3%, 95.8%, and 88.2% and specificities were 100%, 100%, and 95.0%, respectively. CONCLUSIONS: The close similarity of the sensitivity and specificity of FFR and d-FFR, around almost identical cutoff values (0.75 versus 0.76), confirms the physiological validity of FFR as a clinical standard. In clinical practice, FFR remains the index of choice for assessment of the functional severity of moderate coronary artery stenoses.

Blood Flow Velocity↗
PubMed2003

Matching marine reserve design to reserve objectives.

Recent interest in using marine reserves for marine resource management and conservation has largely been driven by the hope that reserves might counteract declines in fish populations and protect the biodiversity of the seas. However, the creation of reserves has led to dissension from some interested groups, such as fishermen, who fear that reserves will do more harm than good. These perceived differences in the effect of marine reserves on various stakeholder interests has led to a contentious debate over their merit. We argue here that recent findings in marine ecology suggest that this debate is largely unnecessary, and that a single general design of a network of reserves of moderate size and variable spacing can meet the needs and goals of most stakeholders interested in marine resources. Given the high fecundity of most marine organisms and recent evidence for limited distance of larval dispersal, it is likely that reserves can both maintain their own biodiversity and service nearby non-reserve areas. In particular, spillover of larger organisms and dispersal of larvae to areas outside reserves can lead to reserves sustaining or even increasing local fisheries. Ultimately, the success of any reserve network requires attention to the uncertainty and variability in dispersal patterns of marine organisms, clear statements of goals by all stakeholder groups and proper evaluation of reserve performance.

Conservation of Natural Resources↗
PubMed2002

What is cognitive reserve? Theory and research application of the reserve concept.

The idea of reserve against brain damage stems from the repeated observation that there does not appear to be a direct relationship between the degree of brain pathology or brain damage and the clinical manifestation of that damage. This paper attempts to develop a coherent theoretical account of reserve. One convenient subdivision of reserve models revolves around whether they envision reserve as a passive process, such as in brain reserve or threshold, or see the brain as actively attempting to cope with or compensate for pathology, as in cognitive reserve. Cognitive reserve may be based on more efficient utilization of brain networks or of enhanced ability to recruit alternate brain networks as needed. A distinction is suggested between reserve, the ability to optimize or maximize normal performance, and compensation, an attempt to maximize performance in the face of brain damage by using brain structures or networks not engaged when the brain is not damaged. Epidemiologic and imaging data that help to develop and support the concept of reserve are presented.

Aged↗
PubMed1987

Characterization of subcolumnar reserve cells and other epithelia of human uterine cervix. Demonstration of diverse cytokeratin polypeptides in reserve cells.

We have analyzed the expression of cytokeratin polypeptides in subcolumnar reserve cells of the human uterine endocervical mucosa and the other epithelial cells using immunoperoxidase and immunofluorescence microscopy as well as by applying two-dimensional gel electrophoresis to microdissected cytoskeletal preparations. Endocervical columnar cells were uniformly positive for antibodies directed against the simple epithelium-type cytokeratins nos. 7, 8, 18, and 19, while a variable proportion of these cells was stained by an antibody against cytokeratin no. 4. Reserve cells were not only positive for cytokeratins nos. 8 (weakly and variably) and 19 but were also decorated by antibody KA 1, which reacts with cytokeratins present in stratified squamous epithelia. This last antibody selectively decorated reserve cells even when they were flat and inconspicuous. Antibody KA 1 uniformly stained the ectocervical squamous epithelium, the basal cells of which were also decorated by antibodies directed against cytokeratins nos. 8 (weakly and variably) and 19. Ectocervical suprabasal cells were positive, to a variable extent, for antibodies against cytokeratins nos. 4, 10/11, and 13. Gel electrophoresis revealed the presence of squamous-type cytokeratins nos. 5 and 17 in reserve cell-rich, but not in reserve cell-free, endocervical mucosa. We also analyzed the distribution pattern of these cells, as revealed by antibody KA 1, in the endocervical mucosa of 26 uteri. In all the specimens examined reserve cells were present, but their numbers exhibited considerable variation. In some cases these cells were confined to small islets localized deep within the cervical canal and lacked any continuity with the squamous epithelium. The expression of cytokeratins nos. 5 and 17 in reserve cells indicates that these cells have undergone a low level of squamous differentiation. The additional expression of cytokeratins nos. 8 and 19 in these cells points to a relationship with simple epithelial cells. The present data would seem to favor the view that reserve cells originate in situ from the columnar epithelium; however, this would imply an acquisition of new differentiation properties.

Adult↗
PubMed1995

Comparison of pressure-derived fractional flow reserve with poststenotic coronary flow velocity reserve for prediction of stress myocardial perfusion imaging results.

The physiologic importance of coronary stenoses can be assessed indirectly by stress myocardial perfusion imaging or directly by translesional pressure and flow measurements. The aims of this study were to compare myocardial fractional flow reserve (FFRmyo), a recently proposed index of lesion significance derived from hyperemic translesional pressure gradients, with directly measured poststenotic flow velocity reserve for the prediction of myocardial perfusion stress imaging results in corresponding vascular beds. Poststenotic coronary flow velocity (0.018-inch guide wire) and translesional pressure gradients (2.7F fluid-filled catheter) were measured at baseline and after intracoronary adenosine (12 to 18 micrograms) in 70 arteries (diameter stenosis: mean 56% +/- 15%, range 14% to 94% by quantitative angiography). Coronary flow reserve was calculated as the ratio of hyperemic to basal mean flow velocity. FFRmyo was calculated during maximal hyperemia as equal to 1-(hyperemic gradient [mean aortic pressure-5]), where 5 is the assumed central venous pressure. Positive and negative predictive values and predictive accuracy for reversible stress myocardial perfusion abnormalities were computed. There was a significant correlation between pressure-derived FFRmyo and distal coronary flow reserve (r = 0.46; p < 0.0001). The strongest predictor of stress myocardial perfusion imaging results was the poststenotic coronary flow reserve (chi square = 33.2; p < 0.0001). The correlation between stress myocardial perfusion imaging and FFRmyo was also significant (chi square = 8.3; p < 0.005). There was no correlation between stress myocardial perfusion imaging and percentage diameter stenosis (chi square = 2.9; p = 0.10) or minimal lumen diameter (chi square = 0.47; p = 0.73). A poststenotic coronary flow reserve of < or = 2 had a positive predictive value of 89% for regionally abnormal myocardial perfusion imaging abnormalities, whereas the positive predictive values of FFRmyo and angiographic percentage diameter stenosis were only 71% and 67% respectively. In conclusion, the predictive value of poststenotic coronary flow velocity reserve for stress-induced myocardial perfusion abnormalities exceeds that of the translesional FFRmyo. These findings should be considered when applying these techniques for clinical decision making in the assessment of coronary stenosis severity.

Adult↗
PubMed1999

Non-invasive evaluation of coronary reserve. Assessment of coronary reserve in patients with coronary artery disease by transesophageal-Doppler echocardiography.

We assessed coronary flow reserve using transesophageal Doppler echocardiography in patients with coronary artery disease. The study included 33 coronary artery disease patients who were undergoing coronary arteriography. The blood flow velocities of the left anterior descending artery before and after intravenous infusion (0.56 mg/min for 4 min) of dipyridamole were recorded using transesophageal Doppler echocardiography. Fourteen normal healthy individuals, matched for age, served as a control group. The index of coronary flow reserve, i.e. the ratio of dipyridamole to baseline maximum diastolic velocity, was calculated. Maximal coronary flow reserve in coronary artery disease patients was significantly lower than in the control group (1.4+/-0.2 vs. 2.8+/-0.3, P<0.001). The coronary artery disease patients were classified into three groups: Group A included 10 patients with <50% left anterior descending artery stenosis; Group B included seven patients with 50-69% left anterior descending artery stenosis; 16 patients with >70% left anterior descending artery stenosis constituted Group C. The maximum coronary flow reserve was significantly different for A vs. B and A vs. C. (A, 1.77+/-0.18; B, 1.51+/-0.1; C, 1.28+/-0.24). A strong and significant correlation was found between the maximum coronary flow reserve and the degree of proximal left anterior descending artery stenosis (r=0.78, P<0.001). Coronary artery disease patients without left anterior descending artery stenosis on the arteriogram exhibited lower maximum coronary flow reserve compared to the control subjects (1.78+/-0.19 vs. 2.8+/-0.3, P=0.000).

Analysis of Variance↗
PubMed2006

Assessment of ovarian reserve--should we perform tests of ovarian reserve routinely?

Women undergoing IVF are routinely subjected to one or more tests of ovarian reserve. The results of these tests are also being extrapolated to women attending infertility clinics and those planning to delay childbearing. This debate examines the predictive power of currently available tests of ovarian reserve and questions the value of subjecting women to ovarian reserve tests. We propose that in the absence of an agreement on (i) a definition of poor ovarian reserve, (ii) the population to be tested and (iii) which interventions are effective in women with poor ovarian reserve, routine ovarian reserve testing is unhelpful.

Estradiol↗
PubMed2005

Low genetic diversity in a marine nature reserve: re-evaluating diversity criteria in reserve design.

Little consideration has been given to the genetic composition of populations associated with marine reserves, as reserve designation is generally to protect specific species, communities or habitats. Nevertheless, it is important to conserve genetic diversity since it provides the raw material for the maintenance of species diversity over longer, evolutionary time-scales and may also confer the basis for adaptation to environmental change. Many current marine reserves are small in size and isolated to some degree (e.g. sea loughs and offshore islands). While such features enable easier management, they may have important implications for the genetic structure of protected populations, the ability of populations to recover from local catastrophes and the potential for marine reserves to act as sources of propagules for surrounding areas. Here, we present a case study demonstrating genetic differentiation, isolation, inbreeding and reduced genetic diversity in populations of the dogwhelk Nucella lapillus in Lough Hyne Marine Nature Reserve (an isolated sea lough in southern Ireland), compared with populations on the local adjacent open coast and populations in England, Wales and France. Our study demonstrates that this sea lough is isolated from open coast populations, and highlights that there may be long-term genetic consequences of selecting reserves on the basis of isolation and ease of protection.

Analysis of Variance↗
PubMed1995

Improvement of subendocardial myocardial perfusion after percutaneous transluminal coronary angioplasty. A myocardial contrast echocardiography study with correlation between myocardial contrast reserve and Doppler coronary reserve.

BACKGROUND: After angioplasty coronary reserve improves but does not normalize in most patients. The purpose of this study was to examine before and after angioplasty coronary reserve and transmural myocardial blood flow distribution using myocardial contrast echocardiography. METHODS AND RESULTS: Twelve patients with left anterior descending coronary artery stenosis were investigated before and immediately after angioplasty. A Doppler catheter was placed in the proximal segment. Myocardial contrast echocardiography was performed by imaging the septum in M mode in a parasternal view using a 3.0-mL bolus of sonicated amidotrizoate sodium meglumine through the guiding catheter. The gray level before injection was subtracted from the gray level after injection to maximize contrast time-intensity curves. The area under the curve was used as an indicator of myocardial blood flow, and subendocardial/subepicardial ratios were measured. After baseline measurements were obtained, Doppler and echographic data were recorded after a bolus infusion of papaverine into the left main coronary artery. The same protocol was performed in patients after angioplasty and in five control subjects with normal coronary arteries. Before angioplasty, echocardiographic and Doppler coronary reserve were 2.57 +/- 0.48 and 2.54 +/- 0.57, respectively. Both increased after angioplasty to 3.65 +/- 0.57 and 3.36 +/- 0.70, respectively (P < .05). Coronary reserve values obtained in patients with these two methods under the different conditions and in control subjects were correlated (r = .81; P = .0001). Before angioplasty, subendocardial/subepicardial septal ratios decreased from 0.80 +/- 0.48 to 0.60 +/- 0.27 after papaverine (P < .05). However, after angioplasty, these ratios tended to increase, from 0.72 +/- 0.27 to 0.92 +/- 0.45 after papaverine, but they did not change in control subjects (1.11 +/- 0.23 to 0.92 +/- 0.11). CONCLUSIONS: These results show that myocardial contrast echocardiography yields flow reserve values that correlate with values obtained using intracoronary Doppler. This technique may be considered as an accurate tool to assess coronary reserve in humans.

Angioplasty, Balloon, Coronary↗
PubMed1994

Coronary reserve and contractile reserve in crystalloid- and blood-perfused rabbit hearts.

Coronary reserve and contractile reserve were compared between crystalloid-perfused and blood-perfused rabbit hearts at various perfusion pressures (40-110 mmHg). Contractile function of the crystalloid-perfused hearts was dependent on the perfusion pressure, according to Gregg's phenomenon. Developed left ventricular pressure (LVP) increased from 67 +/- 6 mmHg to 121 +/- 5 mmHg and positive dP/dt maximum (dP/dt max) from 1,083 +/- 75 to 2,233 +/- 126 mmHg/s at perfusion pressures between the lowest and highest perfusion pressure. In the blood-perfused hearts, the perfusion pressure-induced changes were less pronounced: developed LVP changed from 107 +/- 11 mmHg to 138 +/- 8 mmHg and dP/dt max from 1,517 +/- 181 to 2,008 +/- 187 mmHg/s. The blood-perfused hearts showed better cardiac function, especially negative dP/dt minimum (dP/dt min), compared to the crystalloid-perfused hearts. Contractile reserve estimated by paired pacing technique was quite independent of the perfusion pressure in the blood-perfused hearts but not in the crystalloid-perfused hearts, and was significantly better in the blood-perfused hearts (e.g., 81% increase of developed LVP with blood perfusion, and 26% increase with crystalloid perfusion at a perfusion pressure of 80 mmHg). Coronary reserve, estimated by reactive hyperemia, was independent of the perfusion pressure in both groups. Coronary reserve was small in the crystalloid-perfused hearts (< 23%) and more than double the control value in the blood-perfused hearts. It is proposed that blood-perfused hearts are more suitable for physiological and pathophysiological studies.

Animals↗
PubMed1992

[Extent and degree of coronary flow reserve in hypertrophic cardiomyopathy assessed by delta Fract map unfolding coronary flow reserve index].

Patients with hypertrophic cardiomyopathy (HCM) are known to have ischemic events and decreased coronary flow reserve, but the variabilities in the site and degree of fall between patients with this disease have not been clarified. To elucidate these variabilities, we performed exercise myocardial single photon emission computed tomography (SPECT) using double dose method in 30 patients with HCM (6 with obstruction, 17 with non-obstruction, 7 with apical hypertrophy) and 10 normals. Then, the delta Fract (coronary flow reserve index) map was obtained for each subject. Exercise and then rest Tl-201 myocardial scintigraphy were performed after administration of Tl-201. The data were reconstructed, making the circumferential curves from the same level of short-axis imaging during exercise and at rest. By subtracting the values at rest from the values during exercise, which were divided by the values at rest, delta Fract in each frame was obtained, and described on the unfolded map. The extent and degree of coronary flow reserve were visually estimated by this delta Fract map. Patients were categorized into 5 groups: diffuse fall of coronary flow reserve (D-type), 6 cases; localized fall of the septum or lateral wall (L-type), 5 cases; fall of apical region (A-type), 5 cases; mild fall (M-type), 6 cases; and normal pattern (N-type), 8 cases. We concluded that delta Fract map is useful for evaluating the extent and degree of coronary flow reserve in HCM.

Adult↗
PubMed1996

[Evaluation of reserved hepatic function in patients with hepatobiliary tumor by 99mTc-GSA: effect of hyperbilirubinemia and usefulness of regional reserved hepatic functional imaging].

The evaluation of the reserved hepatic function was performed by 99mTc-galactosyl serum albumin (99mTc-GSA) in seventy patients with hepatobiliary tumor. The dynamic study was performed to evaluate global reserved hepatic function following the intravenous bolus injection of 99mTc-GSA, and the hepatic single photon emission computed tomography (SPECT) was obtained to assess the regional reserved hepatic function. The functional hepatic index (LHL15) was derived from liver time-activity data, and it was compared with serum total-bilirubin level, serum albumin level and plasma disappearance rate of indocyanine green (ICG15). In the patients with hepatocellular carcinoma, LHL15 value agreed well with ICG15 value, serum total-bilirubin level, and serum albumin level. Moderate or severe hepatic dysfunction was observed at 65.4% of these patients. In the patients with cholangiocellular carcinoma, a discrepancy of LHL15 value and ICG15 value was observed. Increment of the ICG15 value was correlated with that of the serum total-bilirubin level, whereas the correlations was not observed between the LHL15 value and the serum total-bilirubin level. These results indicate that 99mTc-GSA scintigraphy can evaluate the reserved hepatic function without the embellishment of jaundice. This method is useful for assessing the global and regional reserved hepatic function.

Aged↗
PubMed2002

A mathematical model for pattern of change in beta-cell reserve and factors affecting residual reserve within the first 2 years of type 1 diabetes.

The aim of this study was to investigate the effects of age, duration of diabetes, sex and ICA (Islet cell cytoplasmic antibody) on beta-cell reserves and to develop a model within the first 2 years of Type 1 diabetes. Beta-cell reserve is evaluated as fasting (FCp) and 1 mg i.v. glucagon stimulated C-peptide (SCp) levels in 58 Type 1 diabetics and in 12 normoglycemic subjects. Patients were divided into 3 groups according to duration of diabetes: Group I (2.5+/-0.3 weeks), Group II (13.4+/-1.2 months) and Group III (24.2+/-1.8 months). FCp/SCp level in nmol/l (mean+/-SE) were as follows. Group I: 0.21+/-0.02/0.38+/-0.04, Group II: 0.15+/-0.01/0.27+/-0.02, Group III: 0.07+/-0.01/0.11+/-0.02, CONTROL GROUP: 0.42+/-0.09/1.29+/-0.13. The scatter plots of C-peptide levels vs time in all the diabetic patients fitted in to a 4th-order polynomial regression (R: 0.96-0.98). Age was strongly correlated with FCp (rs: 0.46, p<0.05) and ICA positivity affected Cp-levels negatively (p>0.05). In conclusion, as the duration of diabetes increases, response time to glucagon prolongs and amplitude of it shortens. Duration of diabetes of less than 2 weeks, feminity, puberty and ICA positivity affect beta-cell reserve negatively, conversely, masculinity, post-puberty, older age and ICA negativity affect the reserve positively. The dynamics of C-peptide response to glucagon follow a mathematical model and Type 1 diabetes causes a decrease not only in the amplitude of the response but also in the duration of the response.

Adolescent↗
PubMed2003

Coronary flow reserve in patients with vasospastic angina: correlation between coronary flow reserve and age or duration of angina.

OBJECTIVES: This study sought to assess the coronary flow reserve (CFR) in patients with pure vasospastic angina (VSA). METHODS AND RESULTS: The phasic flow velocities of both spasm-positive and spasm-negative coronary arteries of the left anterior descending artery (LAD) were recorded at rest and during hyperaemia (50 microg of adenosine triphosphate infusion intracoronary) using a 0.014 inch, 15 MHz Doppler guide wire in 42 patients with pure VSA and acetylcholine (ACh)-induced coronary artery spasms (20-100 microg), and 23 controls with normal coronary arteries without ACh-induced vasospasm. These 42 patients had 16 vessels with focal spasms (>99%), 17 vessels with diffuse spasms (>90%) in the LAD, and nine vessels with ACh-induced spasms in the right coronary artery, but not the LAD. Coronary flow reserve was obtained from the ratio of the hyperaemic/baseline time-averaged peak velocity. Coronary flow reserve did not differ between patients with VSA and the controls (2.9+/-0.8 versus 3.2+/-0.7, NS). Moreover, CFR did not differ among the four cases (focal: 2.8+/-0.7; diffuse: 3.0+/-0.9; non spasm: 2.9+/-0.7 versus controls: 3.2+/-0.7, respectively, NS). Coronary flow reserve in vessels with proximal spasms was significantly higher than that in vessels with mid or distal spasms (3.4+/-0.8 versus 2.6+/-0.6, 2.6+/-0.9, p<0.05). The only significant correlation was between CFR and age (p=0.0275) or the duration of angina before admission (p=0.0405). CONCLUSIONS: There was no difference in CFR in patients with ACh-induced spasms between the spasm-positive and spasm-negative vessels. Moreover, CFR was maintained normally in vessels with diffuse spasms, as in those with focal spasms. The most important determinant factors for CFR in patients with VSA were age and the duration of angina before admission.

Age Factors↗
PubMed1992

Comparison of drug use rates for reservation Indian, non-reservation Indian and Anglo youth.

Rates of drug use and involvement were compared for three groups: Indian youth living on reservations, Indian youth living off reservations and Anglo youth. A consistent pattern emerged, showing the lowest rates of use among Anglo youth, higher rates among non-reservation Indian youth, and the highest rates among Indian youth on reservations. Rates of tobacco use, both smoked and smokeless, and marijuana use are especially high for Indian youth. Indian youth also show a pattern of earlier initiation to drug use. Gender differences reveal slightly higher rates of use for males, although the differences are not great enough to suggest that prevention efforts for males should have a higher priority.

Adolescent↗