The ASPREE Healthy Ageing Biobank: Methodology and participant characteristics

ASPirin in Reducing Events in the Elderly (ASPREE), a placebo-controlled prevention trial of low dose aspirin, provided the opportunity to establish a biospecimen biobank from initially healthy persons aged 70+ years for future research. The ASPREE Healthy Ageing Biobank (ASPREE Biobank) collected, processed and stored blood and urine samples at -80degC or under nitrogen vapour at two timepoints, three years apart, from a willing subset of Australian ASPREE participants. Written informed consent included separate opt-in questions for biomarker and genetic testing. Fractionated blood and urine were aliquoted into multiple low-volume, barcoded cryotubes for frozen storage within 4 hours of collection. Specially designed and outfitted mobile laboratories provided opportunities for participation by people in regional and rural areas. Detailed, high quality demographic, physiological and clinical data were collected annually through the ASPREE trial. 12,219 participants contributed blood/urine at the first timepoint, 10,617 of these older adults provided 3-year follow-up samples, and an additional 1,712 provided saliva for DNA. The mean participant age was 74 years, 54% were female and 46% lived outside major cities. Despite geographical and logistical challenges, nearly 100% of blood/urine specimens were processed and frozen within 4 hours of collection into >1.4 million aliquots. After a median of 4.7 years, major clinical events among ASPREE Biobank participants included 332 with dementia, 613 with cardiovascular disease events, 1259 with cancer, 357 with major bleeds and 615 had died. The ASPREE Biobank houses and curates a large number of biospecimens collected prior to the clinical manifestations of major disease, and 3-year follow-up samples, all linked to high quality, extensive phenotypic information. This provides the opportunity to identify or validate diagnostic, prognostic and predictive biomarkers, and potentially study biological effectors, of ageing-related diseases or maintenance of older-age good health.

Arrhythmogenic right ventricular cardiomyopathy (ARVC): case report and review of literature

Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited condition characterised by fibrofatty replacement of the right ventricle. It causes sudden death in 30% of young adults and in 5% of those less than 65 years of age. As the presentation is non-specific, ARVD can be a diagnostic challenge leading to delayed treatment. We report a case along with the review of literature, of a 63-year-old man who presented (atypical) with a history of palpitations, dizziness and raised cardiac enzymes associated with ECG changes in the inferior and anterior leads. Further investigation helped in confirming this rare and potentially fatal cardiac condition.

Disease progression and adverse events in patients listed for elective percutaneous coronary intervention

OBJECTIVE

To record disease progression and the timing of adverse events in patients on a waiting list for elective percutaneous coronary intervention (PCI).

DESIGN

Observational prospective study.

SETTINGS

A UK tertiary cardiothoracic centre, at a time when waiting lists for PCI were up to 18 months.

PATIENTS

145 patients (116 men, median age 59.5 years) placed on an elective waiting list for PCI between October 1998 and September 1999.

MAIN OUTCOME MEASURES

Adverse events recorded were death, myocardial infarction, need for urgent hospital admission because of unstable angina, and need for emergency revascularisation while waiting for PCI.

RESULTS

During a median follow up of 10 months (range 1-18 months), nine (6.2%) patients experienced an adverse event. Eight (5.52%) patients were admitted with unstable angina as emergencies. One was admitted with a myocardial infarction. Twenty nine (20.0%) patients had significant disease progression at the time of the repeat angiogram before PCI. In 10 (7%), disease had progressed so that PCI was no longer feasible and patients were referred for coronary artery bypass graft. Sixteen (11%) were removed from the PCI waiting list because of almost complete resolution of their anginal symptoms.

CONCLUSION

Adverse coronary events and clinically significant disease progression occur commonly in patients waiting for PCI. Despite the presence of severe coronary lesions, myocardial infarction was rare and no patients died while on the waiting list. Resolution of anginal symptoms was also comparatively common. The pathophysiology of disease progression frequently necessitates a change in the treatment of patients waiting for PCI.

Relation between coronary pressure derived collateral flow, myocardial perfusion grade, and outcome in left ventricular function after rescue percutaneous coronary intervention

OBJECTIVE

To evaluate the relation between pressure derived coronary collateral flow (PDCF) index and angiographic TIMI (thrombolysis in myocardial infarction) myocardial perfusion (TMP) grade, angiographic collateral grade, and subsequent recovery of left ventricular function after rescue percutaneous coronary intervention (PCI) for failed reperfusion in acute myocardial infarction.

METHODS

The pressure wire was used as the guidewire in 38 consecutive patients who underwent rescue PCI between December 2000 and March 2002. Follow up angiography was performed at six months. Baseline and follow up single plane ventriculograms were analysed off line by an automated edge detection technique. A linear model was fitted to assess the relation between 0.1 unit increase in PDCF and change in left ventricular regional wall motion.

RESULTS

Patients with TMP 0 grade had significantly higher mean (SD) PDCF than patients with TMP 1-3 (0.30 (0.11) v 0.15 (0.07), p < 0.0001, r = -0.5). A similar relation was observed between TMP grade and coronary wedge pressure (mean (SD) 28 (16) mm Hg with TMP 0 v 9 (7) mm Hg with TMP 1-3, p = 0.001, r = -0.4). Higher PDCF was associated with increased left ventricular end diastolic pressures (0.28 (0.14) with end diastolic pressure > 20 mm Hg v 0.22 (0.09) with end diastolic pressure < 20 mm Hg, p = 0.08, r = 0.2). No correlation was observed between PDCF and Rentrops collateral grade (0.26 (0.13) with grade 0 v 0.25 (0.11) with grades 1-3, p = 0.4, r = -0.06). No linear relation existed between changes in PDCF and changes in left ventricular regional wall motion.

CONCLUSION

PDCF in the setting of rescue PCI for failed reperfusion after thrombolysis does not predict improvement in left ventricular function. Increased PDCF and coronary wedge pressure in acute myocardial infarction reflect a dysfunctional microcirculation rather than good collateral protection.

Cervical spine alignment in the immobilized ice hockey player. A computed tomographic analysis of the effects of helmet removal

To determine if helmet removal causes a significant increase in lordosis of the cervical spine in ice hockey players, we radiographically assessed the position of the cervical spine in subjects immobilized to a standard spine backboard wearing shoulder pads both with and without a helmet. Ten adult male volunteers (ages, 18 to 28 years) with no previous history of cervical spine injuries were fitted with an appropriately sized ice hockey helmet and shoulder pads and immobilized in a supine position to a standard spine backboard. Computerized tomographic lateral scout scans were obtained of the cervical spine for three conditions: 1) no equipment (control), 2) helmet and shoulder pads, and 3) shoulder pads only (helmet removed). With the helmet removed and the shoulder pads remaining, a significant increase in C2 to C7 lordosis was found when compared with the other two conditions. Individual segmental measurements revealed a significant increase in cervical lordosis at the C6-7 level with the helmet removed compared with the helmet and shoulder pads condition. Our results demonstrate that the removal of an ice hockey helmet from a supine player causes a significant increase in lordosis (extension) of the cervical spine. We recommend that ice hockey helmets not be removed from injured players, with rare exceptions, because doing so results in unnecessary motion of the cervical spine.

A prospective randomized multicenter clinical evaluation of an anterior cervical fusion cage

STUDY DESIGN

A prospective, concurrently controlled, randomized, multicenter trial of an anterior Bagby and Kuslich cervical fusion cage (BAK/C; Sulzer Spine-Tech, Minneapolis, MN) for treatment of degenerative disc disease of the cervical spine.

OBJECTIVES

To report clinical results with maximum 24-month follow-up of fusions performed with the BAK/C fusion cage.

SUMMARY OF BACKGROUND DATA

Threaded lumbar cages have been used during the past decade as a safe and effective surgical solution for chronic disabling low back pain. Threaded cages have now been developed for use in anterior cervical interbody fusions to obviate the need for allografts or autogenous bone grafting procedures while providing initial stability during the fusion process.

METHODS

Patients with symptomatic cervical discogenic radiculopathy were treated with either anterior cervical discectomy with uninstrumented bone-only fusion (ACDF) or BAK/C fusion cage(s). Independent radiographic assessment of fusion was made and patient-based outcome was assessed by visual analog pain scale and a Short Form (SF)-36 Health Status Questionnaire.

RESULTS

Data analysis included 344 patients at 1 year and 180 at 2 years. When the two cage groups (hydroxya, patite-coated or noncoated) were compared with the ACDF group, similar outcomes were noted for duration of surgery, hospital stay, improvements in neck pain and radicular pain in the affected limb, improvements in the SF-36 Physical Component subscale and Mental Component subscale, and the patients' perception of overall surgical outcome. Symptom improvements were maintained at 2 years. A greater percentage of patients with ACDF needed an iliac crest bone harvest than did BAK/C patients (67% vs.- 3%). Successful fusion for one-level procedures at 12 months was 97.9% for the BAK/C groups and 89.7% for the ACDF group (P < 0.05). The complication rate for the ACDF group was 20.4% compared with an overall complication rate of 11.8% with BAK/C. There was no difference in complications that necessitated a second operative procedure.

CONCLUSIONS

These results demonstrate that outcomes after a cervical fusion procedure with a threaded cage are the same as those of a conventional uninstrumented bone-only anterior discectomy and fusion with a low risk of complications and rare need for autogenous bone graft harvest.

Arrhythmogenic right ventricular dysplasia. An illustrated review highlighting developments in the diagnosis and management of this potentially fatal condition

Arrhythmogenic right ventricular dysplasia is an inherited, progressive condition. Characterised by fatty infiltration of the right ventricle, it frequently results in life threatening cardiac arrhythmias, and is one of the important causes of sudden cardiac death in the young. There are characteristic electrocardiographic and echocardiographic features that all physicians need to be aware of if we are to reduce these occurrences of premature death. Diagnosis with magnetic resonance imaging is discussed along with current treatment options.

Magnetic resonance evaluation of recurrent disc herniation: is gadolinium necessary?

STUDY DESIGN

Evaluation of magnetic resonance images (MRIs) with surgical reference standard.

OBJECTIVES

To determine whether the addition of contrast-enhanced MRI scans increases diagnostic efficacy in the evaluation of recurrent disc herniation.

SUMMARY OF BACKGROUND DATA

Many centers now routinely use gadolinium-enhanced examinations in the evaluation of recurrent disc herniation. Others, noting the additional expense of contrast injection, advocate a more limited role for contrast injection and emphasize the importance of T2-weighted axial sequences.

METHODS

The study included 165 consecutive patients who were referred to the authors' outpatient imaging center and had a history of previous lumbar discectomy and recurrent back and/or leg pain. The scanning protocol included sagittal and axial T1-weighted spin-echo pre- and postcontrast injection images and sagittal and axial T2-weighted fast spin-echo images. Twenty-eight patients (32 vertebral levels) had subsequent surgical exploration of a disc margin that had previously undergone discectomy. The surgical findings formed the reference standard. Three spine radiologists interpreted the MRI examinations without knowledge of the surgical results. They first interpreted the unenhanced studies, indicated whether they felt contrast injection would be helpful in further evaluation, and then (regardless of this determination) read the postcontrast study.

RESULTS

On pre- and post-contrast examinations Reader 1 had a sensitivity of 95% (20/21), a specificity of 100% (10/10), and an accuracy of 97% (30/31). Reader 2 had a sensitivity of 95% (20/21), a specificity of 90% (9/10), and an accuracy of 94% (29/31). Reader 3 had a sensitivity of 90% (19/21), a specificity of 100% (10/10), and an accuracy of 94% on the precontrast examinations. His postcontrast performance demonstrated a sensitivity of 86% (18/21), a specificity of 100% (10/10), and an accuracy of 90% (28/31). In the nine interpretations wherein the readers thought that a contrast-enhanced examination might provide useful additional information, they did not change their interpretations in three cases, improved their interpretations in two, and made their interpretations worse in four on the basis of addition of the enhanced images.

CONCLUSIONS

Routine use of contrast-enhanced examinations in patients who have had prior lumbar surgery probably adds little diagnostic value and may be confusing.

The magnetic resonance imaging appearance of individual structures of the posterolateral knee. A prospective study of normal knees and knees with surgically verified grade III injuries

The purpose of this study was to contrast the magnetic resonance imaging appearance of uninjured components of the posterolateral knee with that of injured structures, and to assess the accuracy of magnetic resonance imaging in identifying posterolateral knee complex injuries. Thin-slice coronal oblique T1-weighted images through the entire fibular head were used to identify the posterolateral structures in seven uninjured knees. The appearance of corresponding grade III injuries to these structures was identified prospectively in 20 patients and verified at the time of surgical reconstruction. The sensitivity, specificity, and accuracy of imaging for the most frequently injured posterolateral knee structures in this series were as follows: iliotibial band-deep layer (91.7%, 100%, and 95%), short head of the biceps femoris-direct arm (81.3%, 100%, and 85%), short head of the biceps femoris-anterior arm (92.9%, 100%, and 95%), midthird lateral capsular ligament-meniscotibial (93.8%, 100%, and 95%), fibular collateral ligament (94.4%, 100%, and 95%), popliteus origin on femur (93.3%, 80%, and 90%), popliteofibular ligament (68.8%, 66.7%, and 68%), and the fabellofibular ligament (85.7%, 85.7%, and 85.7%). Magnetic resonance imaging of the knee was accurate in the identification of these injuries.

Maternal smoking and Down syndrome: the confounding effect of maternal age

Inconsistent results have been reported from studies evaluating the association of maternal smoking with birth of a Down syndrome child. Control of known risk factors, particularly maternal age, has also varied across studies. By using a population-based case-control design (775 Down syndrome cases and 7,750 normal controls) and Washington State birth record data for 1984-1994, the authors examined this hypothesized association and found a crude odds ratio of 0.80 (95% confidence interval 0.65-0.98). Controlling for broad categories of maternal age (<35 years, > or =35 years), as described in prior studies, resulted in a negative association (odds ratio = 0.87, 95% confidence interval 0.71-1.07). However, controlling for exact year of maternal age in conjunction with race and parity resulted in no association (odds ratio = 1.00, 95% confidence interval 0.82-1.24). In this study, the prevalence of Down syndrome births increased with increasing maternal age, whereas among controls the reported prevalence of smoking during pregnancy decreased with increasing maternal age. There is a substantial potential for residual confounding by maternal age in studies of maternal smoking and Down syndrome. After adequately controlling for maternal age in this study, the authors found no clear relation between maternal smoking and the risk of Down syndrome.

Large airway obstruction by a chronic dissecting aortic aneurysm in the Marfan syndrome

We describe a patient with the Marfan syndrome who presented with an acute aortic dissection. She underwent composite graft replacement of the aortic root. She returned two years later with dyspnoea and stridor due to tracheal compression by a large chronic dissection of the thoracic aorta. Marfan patients are at risk of chronic dissection involving the remaining distal aorta and require regular noninvasive assessment following surgery.

Sclerosing epithelioid fibrosarcoma: short T2 on MR imaging

A case of sclerosing epithelioid fibrosarcoma and its appearance on MRI is presented. The tumor showed a zonal architecture on MRI with a large central core of very low signal intensity and a peripheral rim of intermediate to high signal intensity on T1- and T2-weighted spin echo pulse sequences. The core showed decreased cellularity with dense collagen deposition on histologic examination, and the peripheral zone increased cellularity with increased nuclear atypia. The presence of a prominent region of very low signal intensity on T1- and T2- weighted images can be seen with neural tumors, giant cell tumor of the tendon sheath, aggressive fibromatosis, and, in rare instances, with soft tissue sarcomas rich in collagen.

Rationale, design and methodology for the Navajo Health and Nutrition Survey

As recently as 1990, there was no reservation-wide, population-based health status information about Navajo Indians. To remedy this shortcoming, the Navajo Health and Nutrition Survey was conducted from 1991 to 1992 to assess the health and nutritional status of Navajo Reservation residents using a population-based sample. Using a three-stage design, a representative sample of reservation households was selected for inclusion. All members of selected households 12 y of age and older were invited to participate. A total of 985 people in 459 households participated in the study. Survey protocols were modeled on those of previous national surveys and included a standard blood chemistry profile, complete blood count, oral glucose tolerance test, blood pressure, anthropometric measurements, a single 24-h dietary recall and a questionnaire on health behaviors. The findings from this survey, reported in the accompanying papers, inform efforts to prevent and control chronic disease among the Navajo. Lessons learned from this survey may be of interest to those conducting similar surveys in other American Indian and Alaska Native populations.

Weight, body image, and weight control practices of Navajo Indians: findings from the Navajo Health and Nutrition Survey

Historically, the Navajo exhibited a low prevalence of overweight, but a number of small studies over the past few decades indicate that the prevalence is increasing. In the population-based Navajo Health and Nutrition Survey conducted in 1991-92, overweight was defined as a body mass index (BMI, kg/m2) at or above the 85th percentile (BMI > 27.8 for men, > 27.3 for women) of the Second National Health and Nutrition Examination Survey. One third of men age 20 and 39 and one half of men age 40 and 59, but fewer than 10% of men age 60 and older were overweight. Two thirds or more of women in all age groups were overweight. Nineteen percent of the participants underestimated their weight status (underweight, appropriate, overweight) relative to their BMI category and 17% overestimated their weight status. Women overestimated their weight status more often than men (P < 0.05), and participants age 20-39 overestimated their weight status more often than older participants (P < 0.001). Men and women age 60 and older preferred heavier body shape models as ideals of health more often than younger participants (P < 0.001). Nearly half of the participants, regardless of their weight status, reported that they were trying to lose weight; most reported using diet and exercise. Because overweight is an important risk factor for many chronic diseases, including diabetes mellitus, cardiovascular disease and cancer, primary prevention of overweight and weight management for adults are recommended to prevent an increase in the burden of chronic disease among the Navajo.

Prevalence of hypertension among Navajo Indians: findings from the Navajo Health and Nutrition Survey

Hypertension and other chronic diseases are becoming increasingly important health problems for many Native American people, including the Navajo. A community-based survey that included three standardized measurements of blood pressures, was conducted during 1991-92 on the Navajo Reservation. Among the 780 adults examined, the overall age-standardized prevalence of hypertension, defined as an elevated systolic (> or = 140 mm Hg) or diastolic (> or = 90 mm Hg) blood pressure, or possession of prescription antihypertensive medications, was 19% (24% among men and 15% among women). The prevalence of hypertension increased with age and relative weight, and among men, was associated with diabetes mellitus. Among women, hypertension was associated with a central distribution of body fat, cigarette smoking, self-reported diabetes mellitus and impaired glucose tolerance. Although only 50% of the persons found to have elevated blood pressure at the examination reported they had been previously told that they had hypertension, persons who had been previously diagnosed with hypertension had a slightly higher rate (approximately 60%) of blood pressure control than that seen in the general U.S. population. On the basis of these results, the prevalence of hypertension among the Navajo appears to have substantially increased since the 1930s. Improved prevention and management of hypertension, especially for overweight and diabetic individuals, may reduce morbidity and mortality from cardiovascular and renal disease.

Imaging of acute injuries to the wrist and hand

This article reviews the basic characteristics of common fractures and dislocations in the hand and wrist. There is increasing recognition that fractures and dislocations of the hand and wrist can result in long-term pain and dysfunction. This article includes descriptions and, when helpful, classifications for these fractures with attention to those features that are of prognostic and therapeutic significance. With prompt recognition and proper characterization of these injuries, patients can be triaged to the orthopedic surgeon for early and more aggressive treatment.

Lipoblastoma of the foot

Lipoblastoma is an uncommon benign lipomatous soft tissue mass of childhood, occurring most commonly in children less than 3 years of age. We present a case of lipoblastoma occurring in the foot of a 14-year-old boy and review the literature. The appearance of the mass on magnetic resonance imaging (MRI) is illustrated and is correlated with the findings at gross and microscopic pathological examination. A lobulated architecture, the presence of adipose tissue, thin nonenhancing septa, peripheral lobules of more immature and therefore less specific tissue, and a peripheral pseudocapsule were evident on MRI and at pathological examination.

Blood pressure and body measurements among Navajo adolescents

WE ASSESSED THE PREVALENCE of obesity, high normal blood pressure (BP), and the relationship between BP and anthropometric measurements in a sample of Navajo adolescents. The prevalence of obesity in boys and girls was 3 times that expected in U.S. white adolescents of the same age (17.1% for boys, 15.9% for girls) using body mass index as a criterion. The prevalence of high normal BP (between the 90th and 95th percentiles) was nearly twice that expected by definition (8.7% for boys and 9.1% for girls). Although systolic blood pressure (SBP) and diastolic blood pressure (DBP) increased significantly with age for boys and not for girls, SBP and DBP increased significantly with increasing body mass for both boys and girls. Given the high prevalence of obesity and the observed association with BP, primary prevention of hypertension among the Navajo should emphasize maintaining a healthy body weight at early ages.

Abnormal Papanicolaou smears and colposcopic follow-up among American Indian and Alaska Native women in the Pacific northwest

BACKGROUND

Mortality that is due to cervical cancer among American Indian and Alaska Native women in the Pacific Northwest exceeds that among women of other races. Nevertheless, little information is available regarding the prevalence and follow-up of abnormal Papanicolaou smears among American Indian and Alaska Native women in the region.

METHODS

We conducted a retrospective review of medical records of American Indian and Alaska Native women seen at 12 Indian Health Service and tribally operated clinics in Washington, Oregon, and Idaho who had an abnormal Papanicolaou smear in 1992.

RESULTS

Of 4547 Papanicolaou smear results reviewed, 280 (6.2 percent) had an abnormal result (dysplasia or carcinoma in situ). Of the recommended colposcopies, 167 of 224 (75 percent) were completed. Women with high-grade squamous intraepithelial lesions were more likely to obtain recommended colposcopy than were women with low-grade squamous intraepithelial lesions. Women treated at clinics that referred patients to outside providers for colposcopy were more likely to have colposcopy than were those who were offered the procedure on site.

CONCLUSIONS

The proportion of Pacific Northwest American Indian and Alaska Native women in Indian Health Service and tribal clinics with abnormal Papanicolaou smears and the proportion who receive colposcopy are similar to those in other populations. The higher rate of cervical cancer mortality among American Indian and Alaska Native women could be due to failure to screen high-risk women. Cytologic screening rates, methods to improve adherence to colposcopy recommendations, and the contribution of other factors to the cause of cervical cancer mortality need to be characterized in this population.

Obesity among Navajo adolescents. Relationship to dietary intake and blood pressure

We evaluated anthropometric measurements, blood pressures, dietary intakes, and self-perceived body image of 352 Navajo Indian adolescents. Thirty-three percent of the girls and 25% of the boys were obese according to a body mass index criterion. Navajo youth tended to have larger skinfolds than their white (National Health and Nutrition Examination Survey II) and Mexican American (Hispanic Health and Nutrition Examination Survey) counterparts, with the greater difference in the subscapular skinfolds indicating a greater amount of truncal rather than peripheral fat. When divided into lower, middle, and upper thirds of body mass index, systolic and diastolic blood pressures were positively related with increasing body mass index for girls, and systolic blood pressure and body mass index were related among boys. The high prevalence of obese adolescents and the apparent effect of the increased weight on blood pressure in this population indicate the need for interventions aimed at improving dietary habits and fitness levels.

Serum cholesterol concentrations among Navajo Indians

Navajo Indians have been reported by earlier investigators to have low concentrations of serum lipids and a low prevalence of hyperlipidemia, as well as low rates of ischemic heart disease. However, no data on serum lipid concentrations among Navajos have been reported for more than two decades. The authors conducted a study to determine the distribution of concentrations of serum total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, and triglyceride among persons 25-74 years old living in a representative community on the Navajo Indian reservation. Data are reported for 255 subjects, 105 men and 150 women, ages 25-74 years. The authors compared these data to those for the general population as determined by the second National Health and Nutrition Examination Survey (NHANES II). TC concentrations among Navajo men were similar to those from NHANES II. TC concentrations among younger Navajo women were similar to those for women younger than 55 years from NHANES II, but were significantly lower among older Navajo women. While 27.6 percent of men ages 25-74 years studied in NHANES II had TC concentrations greater than 240 milligrams per deciliter, 33.8 percent of Navajo men had similarly elevated TC. However, the prevalence of serum TC concentrations greater than 240 milligrams per deciliter among Navajo women (17.5 percent) was about half that among women studied in NHANES II (32.9 percent). A similar pattern was found for low density lipoprotein cholesterol. The researchers concluded that Navajo Indians are no longer characterized by low serum lipid concentrations, that increased cholesterol concentrations may be a harbinger of increasing rates of atherosclerotic coronary heart disease among Navajos, and that attention should be directed to primary prevention of hyperlipidemia in Navajo Indian communities.

Prevalence of diabetes and impaired glucose tolerance among Navajo Indians

OBJECTIVE

To estimate the prevalence of diabetes mellitus and impaired glucose tolerance and the incidence of clinically diagnosed diabetes in a community of Navajo Indians.

RESEARCH DESIGN AND METHODS

We conducted a survey of a representative Navajo community screened for diabetes 3 yr previously. We used 75-g oral glucose tolerance tests to determine the prevalence of diabetes mellitus and impaired glucose tolerance and conducted medical record reviews to identify cases of diabetes that were diagnosed during routine medical care after the earlier study.

RESULTS

By World Health Organization diagnostic criteria, the age-adjusted diabetes prevalence among 419 Navajo Indians 20-74 yr of age was 13.9% (95% confidence interval [CI] 9.2-18.5) for men and 18.4% (95% CI 14-22.8) for women. The ratio of the prevalence of diabetes among the Navajo population studied to that in the general United States population was 2.5. The prevalence of impaired glucose tolerance was 8% (95% CI 3.3-12.7) among men and 12.9% (95% CI 7.9-17.9) among women. Based on clinical diagnoses of diabetes made during routine medical care, mean +/- SE age-adjusted incidence of diagnosed diabetes among men was 8.6 +/- 4.3/1000 person-yr and 11.1 +/- 4.4/1000 person-yr among women.

CONCLUSIONS

Although lower than that of some other tribes, the prevalence of diabetes among Navajo Indians is substantially higher than that in the general U.S. population. The high rate of clinical diagnoses suggests that the prevalence of the disease may continue to rise.

Comparison of computed tomography and magnetic resonance imaging in the evaluation of focal hepatic lesions

Two combined magnetic resonance (MR) spin-echo pulse sequences at 0.35 T were compared with dynamic bolus contrast-enhanced computed tomography (CT) in the evaluation of focal hepatic lesions. Each combined MR sequence was performed in a separate group of patients. The first group consisted of 76 patients in whom a moderately T1-weighted sequence (spin echo [SE] 500/30 [repetition time/echo time]) was combined with a T2-weighted sequence (SE 2000/60). In the second group, consisting of 68 patients, a more heavily T1-weighted sequence (SE 250/15) was combined with the T2-weighted sequence. All studies were evaluated in a retrospective blinded fashion, with construction of receiver operating characteristic curves. We conclude that, in detection of patients with one or more focal hepatic lesions, either combined MR sequence was comparable to CT. In the detection of individual hepatic lesions, the sensitivity of the combined MR sequence with a moderately T1-weighted sequence (SE 500/30 and 2000/60) was essentially equivalent to CT (79 vs 77%, respectively). Additionally, a combined MR sequence with a heavily T1-weighted pulse sequence (SE 250/15 and 2000/60) was not statistically different than CT (86 vs 80%, respectively). These findings were supported by the receiver operating characteristic analysis.

Evidence for a secular change in obesity, height, and weight among Navajo Indian schoolchildren

A survey measuring heights and weights of 1969 schoolchildren residing on the Navajo Indian Reservation was conducted in 1989. The findings were compared with National Center for Health Statistics (NCHS) reference data and with surveys of Navajo children from 1955, 1968, and 1981. Approximately twice as many children exceeded the 95th percentile of weight-for-age (11.2% of girls, 12.5% of boys) than would be expected for the NCHS reference population. The mean weight-for-height z scores exceeded those for the NCHS reference population for all ages in both sexes. Compared with data from 1955, mean heights increased 6.1% among boys and 4.4% among girls whereas mean weights increased 28.8% among boys and 18.7% among girls across all age groups. The data suggest that there has been a secular change in height, weight, and obesity in Navajo Indian children over the past 35 y.

MR imaging of the larynx at 1.5 T

The normal magnetic resonance (MR) anatomy of the larynx at high field strength (1.5 T) was studied in 2 normal excised larynges and 62 subjects without laryngopharyngeal disease. The two normal excised larynges were imaged using a 1.5 T MR scanner with a 3 in diameter circular surface coil and a GE 9800 CT scanner. The larynges were sectioned transversely and the MR and CT images compared to gross and histologic sections. Unossified hyaline cartilage was intermediate in signal intensity on T1-weighted and proton density images and low in intensity on T2-weighted images. The signal intensity from ossified cartilage was determined by the amount of fatty marrow and was high in intensity on T1-weighted and proton density images and low to intermediate in intensity on T2-weighted images. A chemical shift artifact from high intensity fatty marrow obscured the calcified or ossified cortex of the major laryngeal cartilages along the frequency encoding axis. The epiglottic cartilage demonstrated an intermediate signal intensity on T1-weighted images and higher intensity on proton density and T2-weighted images. The intralaryngeal muscles were well demonstrated as low intensity structures. The conus elasticus and the vocal ligaments were not recognized as distinct structures. However, the quadrangular membrane and a previously undescribed membrane separating the preepiglottic and paralaryngeal spaces were shown on MR as low intensity linear structures. In the 62 subjects, MR at 1.5 T proved excellent for demonstrating the anatomical details of the major laryngeal cartilages, extra- and intralaryngeal muscles, ligaments, and soft tissues including the vocal cords, false vocal cords, laryngeal ventricles, aryepiglottic folds, preepiglottic space, and paralaryngeal spaces. Visibility and intensity of muscles, ligaments, and soft tissues did not depend on age or sex. The intensity pattern of the thyroid and cricoid cartilages demonstrated wide variations in the same sex and age groups, depending on the degree of ossification. However, they did show more high intensity foci in older men than in younger women. Magnetic resonance showed better contrast resolution and finer detail than CT scans in the same subjects. Magnetic resonance imaging at 1.5 T, with either a saddle-shaped neck surface coil or a 3 in diameter circular surface coil, provides high contrast and high spatial resolution images and could be useful for the diagnosis of lesions of the larynx.(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of thrombus by using phase-image MR scans: ROC curve analysis

Spin-echo phase images have been shown to be sensitive to blood flow and have been used to differentiate slow flow from thrombus, with an apparent advantage in comparison with spin-echo intensity images alone. In order to quantify the diagnostic efficacy of phase images, a study was performed comparing the sensitivity and specificity of MR imaging in identifying intravascular thrombus using spin-echo magnitude images alone and combined with phase images. In 45 subjects, 66 vessels with questionable intraluminal signal were reviewed in a blinded manner by four radiologists using seven levels of certitude for the diagnosis of thrombus. Vessels in the thorax, abdomen, and pelvis were included in the evaluation and were selected on the basis of the presence of intraluminal signal, which raised the possibility of intravascular disease. Corroborative studies were available in all cases. Receiver-operator-characteristic curves were constructed for the accuracy of the decision of intraluminal thrombus vs flow signal when using magnitude images alone and when using magnitude plus phase images. Magnitude images identified thrombus with a sensitivity of 35% at a specificity of 90%. On the other hand, combining magnitude image and phase images yielded sensitivities of 85% and 83% at specificities of 90% and 95%, respectively. We conclude that addition of phase images substantially increases the level of confidence in detecting intravascular thrombosis.

Normal penile anatomy and abnormal penile conditions: evaluation with MR imaging

The appearance of the normal penis and of a variety of penile abnormalities on magnetic resonance (MR) images was studied in 55 patients with either medium (0.35 T) or high (1.5 T) magnetic field strengths. Penile morphologic characteristics with anatomic detail of the corpora cavernosa and corpus spongiosum were demonstrated in each patient. MR images clearly displayed congenital anomalies (n = 6), penile prostheses (n = 7), fibrous tissue or hematoma due to trauma (n = 8), and fibrous plaque in Peyronie disease (n = 3). MR imaging also demonstrated urethral (n = 6) and penile (n = 5) neoplasms and allowed tumor staging, thus facilitating the surgical approach.

Evaluation of rebreathing in patients undergoing cataract surgery

Ten patients undergoing elective cataract surgery with local anesthesia were evaluated for rebreathing using mass spectrometry and arterial blood gas analysis. Results showed a 10 or 51 oxygen-air mixture with an inspired oxygen concentration of 50% (FIO2) administered via a face tent maintained normal blood gases and a satisfactorily low inspired carbon dioxide (FICO2) in conscious patients who were free of lung disease.

Juvenile xanthogranuloma of the kidney

Juvenile xanthogranuloma is a benign histiocytosis of infancy and childhood characteristically involving the skin, the eye, and, rarely, the lungs, liver and mesothelial structures. This report documents the first known case of renal involvement which is demonstrated by ultrasound and computed tomography.

Fluid balance and the adult respiratory distress syndrome

This study examined the effect of fluid balance on survival in ARDS. Of the 213 patients entered into a prospective data collection study, we evaluated 113 patients who met strict criteria for ARDS. Multiple variables were analyzed for as long as 14 days after intubation including cardiac output, pulmonary capillary wedge pressure, mean blood pressure, intake minus output (I-O), cumulative intake minus output (cum I-O), and change in weight (delta wt). We found significant differences in cum I-O and delta wt between survivors and nonsurvivors on almost every day. Survivors lost weight and had a significantly lower cum I-O compared with nonsurvivors. Logistic regression was used to determine if delta wt and cum I-O could predict survival. Patients who lost 3 kg or more weight had a much higher survival than did those who gained 3 kg or more weight (67 and 0%, respectively, on Day 14). Similar results were obtained using comparably low and high values for cum I-O. The logistic regression equations demonstrated that weight loss and low cumulative I-O correlated with improved survival. Although cause and effect relationships are difficult to determine from these types of analyses, they can be used to formulate prospective studies and predict survival in patients.