Spirometry reference values for American Indian adults: results from the Strong Heart Study.

STUDY OBJECTIVE: To derive spirometry normative values from a large population of American Indian adults and compare them to reference values for white adults. DESIGN: Pulmonary function was assessed using spirometry in participants of the Strong Heart Study, a multicenter, community-based, prospective study of cardiovascular risk factors and disease in American Indians, utilizing American Thoracic Society guidelines and a vigorous quality assurance program. SETTING: Central Arizona, southwestern Oklahoma, central South Dakota, and northeastern North Dakota. PARTICIPANTS: Acceptable spirometry results were obtained from 1,619 women and 1,005 men aged 45 to 74 years. RESULTS: Internal reference values and normal ranges for FEV(1), FVC, and the FEV(1)/FVC ratio were derived from a healthy subgroup of 253 women and 190 men, identified by excluding participants with factors associated with a lower FEV(1). Ten percent of the entire cohort (269 of 2,624 subjects) had airways obstruction, as defined by an FEV(1)/FVC below the lower limit of the normal (LLN) using the internal reference equations. After allowing for measurement "noise," 31 participants were below the LLN using reference equations for white adults from the large National Health and Nutrition Examination Study (NHANES) III study but were normal using the internal reference equations (1.3% false-positive), while 27 participants were classified as normal using NHANES III equations but had airways obstruction using the internal reference equations (1.2% false-negative). Similarly low misclassification rates were seen for a low FVC (prevalence, 17.6%). CONCLUSION: For clinical purposes, NHANES III spirometry reference equations for white adults may be used when testing American Indian women and men aged 45 to 74 years.

Does writing about the bereavement lessen grief following sudden, unintentional death?

Writing about traumatic events produces improvement in an array of areas including physical and psychological functioning. To see if these improvements extended to improved bereavement recovery after the accidental or homicidal death of a loved one, 64 undergraduates (51 women, 13 men) began, and 44 completed, a writing project. At pretest, they completed measures of depression, anxiety, grief, impact, and non-routine health visits. Then, they were randomly assigned to write about either the bereavement experience (profound condition), or innocuous topics (trivial condition). They wrote for 15 minutes a day for four days, then completed the same measures a second time (posttest). Six weeks later, they were mailed the same measures again (follow-up). A 2 (CONDITION: Profound versus Trivial) x 3 (Time: Pre-, Post-, or Follow-up) MANOVA yielded a significant main effect for time, but no main effect for condition and no interaction. Follow-up ANOVAs indicated that, across conditions, from pretest to follow-up testing participants reported less anxiety and depression, less impact, greater grief recovery, but about the same health center visits. A 2 (CONDITION) x 4 (Writing Day) MANOVA and follow-up tests indicated that those in the profound condition reported less subjective distress from Day 1 to Day 3, compared to those in the trivial condition. Combined with Kovac and Range (1999), present results suggest that writing projects may be more beneficial to those experiencing the unique bereavement of suicidal death, rather than those experiencing the nonintentional death of a loved one by accident or homicide.

Cisplatin ototoxicity, increased DPOAE amplitudes, and magnesium deficiency. Distortion product otoacoustic emissions.

Outer hair cell (OHC) metabolism is blocked by cisplatin. Concurrent changes in the renal handling of magnesium occur because of the damage cisplatin causes to the renal proximal tubule cells within the thick ascending loop of Henle. Although there is no evidence of cisplatin within the OHCs, there are significant levels of intracellular calcium, the antagonist to magnesium at the cell membrane. The OHC motile response is dependent on intracellular calcium. When the calcium current is suppressed by an antagonist, the extracellular OHC microphonic potential decreases. Magnesium deficiency is known to produce hyperexcitability within the central nervous system, including fatal audiogenic seizures. In addition, increases in the amplitude of the auditory brainstem response wave V occur with aminoglycoside therapy and magnesium deficiency. This paper illustrates the amplitude growth of distortion product otoacoustic emissions in two patients treated with cisplatin and explores the possible underlying reasons why this may be related to magnesium metabolism.

A simple method of computing hip axis length using fan-beam densitometry and anthropometric measurements.

Hip axis length (HAL), a simple measure obtained from dual X-ray absorptiometry (DXA) scans of the proximal femur, predicts hip fracture, independent of bone mineral density and age. Owing to a magnification error associated with newer fan-beam DXA, automatic calculation of HAL, which is available in pencil-beam DXA, is inaccurate. The purpose of this study was to model HAL, measured from a pencil-beam DXA, as a function of HAL from a fan-beam DXA combined with other anthropometric measures. Proximal femur scans were performed using pencil- and fan-beam DXA in 21 women (ages 24-60). Height, weight, hip circumference, subject thickness, height of the greater trochanter and anterior superior iliac spine from the scanning table, and HAL as measured by a ruler from the scan printouts were recorded. Anthropometric measurements were taken by two researchers; all but the greater trochanter were reproducible (r > or = 0.92). A simple linear model using the manual measurement of HAL from the fan-beam scan, height, weight, body mass index, and hip circumference was able to predict HAL measured using the pencil-beam DXA with a high degree of accuracy (R(2) > or = 0.96). The fan-beam-acquired values of HAL using our model are nonbiased and accurate estimates of the "gold standard" pencil-beam method. This model may provide researchers and clinicians with a simple method of calculating HAL using fan-beam DXA.

Sensorineural hearing loss caused by NSAID-induced aseptic meningitis.

Aseptic meningitis is a rare complication of nonsteroidal anti-inflammatory drug (NSAID) use. Otologic symptoms may include sensorineural hearing loss and tinnitus. A 66-year-old woman sought the care of an otologist for sudden bilateral sensorineural hearing loss and a substantial increase in baseline tinnitus. The patient had previously undergone a left tympanoplasty secondary to cholesteatoma and had been treated for atypical face pain with ibuprofen taken every six hours for three months. Magnetic resonance imaging (MRI) with gadolinium demonstrated abnormal enhancement of the dura mater and the surrounding basal cisterns, with extension of enhancing dura mater into the internal auditory canals. Cerebrospinal fluid examination revealed evidence of aseptic meningitis. An audiogram confirmed new bilateral sensorineural hearing loss. Hearing loss and tinnitus resolved and no abnormalities were observed with MRI when nonsteroidal anti-inflammatory medication was discontinued. Otolaryngologists are well aware of the otologic sequelae in patients with meningitis. However, NSAIDs need to be considered as possible causal agents in the evaluation of meningitis with otologic symptoms.

Conservative management of acoustic neuroma: an outcome study.

OBJECTIVE: This study analyzed selection criteria, clinical outcome, and tumor growth rates in patients with acoustic neuromas in whom the initial management strategy was observation. METHODS: A retrospective review of patients with conservatively managed unilateral acoustic neuromas was conducted. Minimum follow-up was 6 months. Patients with neurofibromatosis Type II were excluded. Differences in tumor growth rates were analyzed by use of the Wilcoxon rank sum test. RESULTS: Sixty-eight patients (31 men and 37 women) with a mean age of 67.1 years were followed for an average of 3.4 years after diagnosis. The reasons for a trial of observation included advanced age (55%), patient preference (21%), minimal symptoms (9%), poor general medical condition (7%), asymptomatic tumor (4%), and tumor in the only hearing ear (4%). Fifty-eight patients (85%) were successfully managed with observation alone. Ten patients (15%) ultimately required treatment (nine received microsurgical treatment and one patient underwent radiosurgical intervention) at a mean time interval of 4.0 years after diagnosis. Forty-eight tumors (71%) showed no growth and 20 (29%) enlarged during the study period. The mean tumor growth rate at the 1-year follow-up was significantly higher in the group requiring treatment (3.0 mm) than in the group not requiring treatment (0.36 mm) (P < 0.0001). Thus, the tumor growth rate at the 1-year follow-up was a strong predictor of the eventual need for treatment. CONCLUSION: Observation is a reasonable management strategy in carefully selected patients with acoustic neuromas. Diligent follow-up with serial magnetic resonance imaging is recommended, because some tumors will enlarge to the point at which active treatment is required.

Aphysiologic performance on dynamic posturography.

The remarkable ability of the body to maintain balance is the result of central nervous system integration of sophisticated inputs from the vestibular, visual, and somatosensory systems. Strategies by patients with balance dysfunction are aphysiologic when their performance is relatively better on more difficult conditions of sensory conflict than on easier ones. Twenty-two aphysiologic patterns on computerized dynamic posturography were compared with age-matched normal and vestibular patterns. The aphysiologic group performed significantly better than the patients in the vestibular dysfunction group on the most difficult subtests of computerized dynamic posturography, conditions 5 and 6, yet significantly poorer on the easier subtests, conditions 1 through 4. In addition, patients in the aphysiologic group tended to show greater intertrial variability compared with patients in both normal and vestibular system dysfunction groups. A stepwise linear discriminant analysis was used to determine a set of conditions that had significant value in discriminating between the three patient groups. Case studies are presented to further illustrate the clinical usefulness of computerized dynamic posturography testing in the evaluation of patients suspected of having a functional component to their on-feet balance problems.

Novel degradation pathway of glycated amino acids into free fructosamine by a Pseudomonas sp. soil strain extract.

A Pseudomonas sp. soil strain, selected for its ability to grow on epsilon-(1-deoxyfructosyl) aminocaproic acid, was induced to express a membrane-bound enzymatic activity which oxidatively degrades Amadori products into free fructosamine. Apparent Km values for fructosyl aminocaproate, epsilon-fructosyl lysine, fructosyl glycine, and ribated lysine were 0.21 mM, 2.73 mM, 3.52 mM, and 1.57 mM, respectively. The enzyme was also active against alpha-fructosyl lysine and borohydride-reduced Amadori product, weakly active with ribated and glycated polylysine, and inactive with reducing sugars, amino acids, and glycated proteins. The enzymatic activity was highest at pH 6.5 and 25 degrees C in 0.1 M sodium phosphate, while over 80% of the activity was lost above 65 degrees C. Complete inhibition was observed by HgCl2, NaN3, and NaCN suggesting a role for SH groups and copper in the enzymatic activity. The reaction products were characterized by 1H NMR, 13C NMR, and GC/MS and found to correspond to 1-deoxy-1-aminofructose, i.e. free "fructosamine," and adipic acid. Confirmation of the free fructosamine structure was based on the complete spectroscopic identity of the borohydride reduction product with commercially available glucamine (1-amino-1-deoxyglucitol). The new enzyme is provisorily classified as fructosyl N-alkyl amino acid oxidase (EC 1.5.3) (fructosyl-amino acid:oxygen oxidoreductase) and may thus belong to a novel class of "Amadoriases" which deglycate Amadori products oxidatively. In contrast, however, the new enzyme acts on the alkylamine bond rather than the ketoamine bond of the Amadori product.

Familial paragangliomas of the head and neck.

OBJECTIVE: It has been known for some time that paragangliomas of the head and neck may be familial. Recent evidence suggests genomic imprinting is an important factor in the clinical development of these tumors. In genomic imprinting the imprintable gene is transmitted in a mendelian manner, but expression of the gene is determined by the sex of the transmitting parent. In the case of paragangliomas, the gene does not result in the development of tumors when maternally inherited. The purpose of this study was to determine if this hypothesis correctly predicted the inheritance pattern of familial paraganglioma in a large series of patients. SETTING: A retrospective review of case records of the Mayo Clinic, Rochester, Minn, a tertiary referral center, was performed for the years 1950 to 1992 to identify patients with familial paragangliomas of the head and neck. PATIENTS: A total of 38 patients with familial paragangliomas of the head and neck were identified in nine kindreds. RESULTS: Carotid body tumors were the most common paragangliomas of the head and neck (34 cases). Glomus jugulare or glomus vagale occurred in eight cases. In 16 (42%) of the patients there were multiple tumors. Surgical complications, primarily cranial nerve palsies, were more frequent for tumors larger than 5 cm in diameter. CONCLUSIONS: An autosomal dominant inheritance pattern could be shown for paragangliomas of the head and neck that was consistent with genomic imprinting. It is recommended that all individuals in kindreds with paragangliomas be screened after the age of 16 years to detect early asymptomatic tumors.

Isolation, purification, and characterization of an Amadori product binding protein from a Pseudomonas sp. soil strain.

Sugars react nonenzymatically with protein amino groups to form a ketoamine adduct (Amadori product), which leads to the formation of advanced glycation end-products. These compounds are involved in the development of tissue modifications such as cross-linking and fluorescence in diabetes and aging. Searching for an enzyme to reverse protein glycation, we isolated a Pseudomonas sp. soil strain growing selectively on the Amadori product epsilon-fructosyl-aminocaproate. An Amadori product binding protein (ABP) was purified from the bacterial extract by single-step affinity chromatography on glycated lysine-Sepharose. The protein, a monomer of 45 kDa, did not bind to unglycated or NaBH4-reduced glycated lysine-Sepharose suggesting specificity for the Amadori compound. The concentration-dependent binding of glycated aminocaproate showed saturation with Kd = 1.49 microM and Bmax = 17.63 nmol/mg of protein corresponding to 0.8 mol/mol of protein. The binding of epsilon-1-[14C]fructosyl-aminocaproate to the protein was inhibited by other glucose-derived Amadori products, but not by free sugars, unglycated amines, or ribated lysine. The sequence of the first 16 NH2-terminal amino acids and a GenBank search revealed that ABP is a novel protein. Its synthesis was inducible by growth of the organism in Amadori product. Immunoblotting studies showed that ABP is not found in cell extracts from other prokaryotes, yeast, or liver homogenate and does not bind Amadori products in glycated proteins. ABP has no enzymatic activity toward glycated substrates and may thus have transport or permease function for glycated amino acids.

Immunoelectron microscopic analyses of Maillard reaction products in bovine anterior lens capsule and Descemet's membrane.

It has been hypothesized that Maillard reaction products form in basement membranes during aging and may affect protein turnover. The purpose of this study was to localize Maillard reaction products in intact lens capsules and Descemet's membranes by immunoelectron microscopy to determine whether Maillard products accumulated with age and whether basement membrane thickness increased to a similar degree. The monoclonal antibodies antiglucitollysine and antipyrraline were employed to detect the products in native and glucose-treated bovine basement membranes. The content of basic amino acids, furosine, and fluorophores (370/440), as well as resistance to trypsin digestion showed that the basement membranes formed significant quantities of Maillard products when incubated with 200 mM glucose in vitro (P < 0.05). Likewise, incubation in 200 mM glucose resulted in at least a 4-fold increase in immunoreactivity (P < 0.001). Native basement membranes increased in thickness more than 2-fold with age (P < 0.001). Immunoreactivity varied similarly in that bound antiglucitollysine increased approx. 2-fold and antipyrraline approx. 3-fold in old vs. young basement membranes, but these differences were significant only in pyrraline immunoreactivity in the lens capsule (P < 0.01). Advanced products other than pyrraline may accumulate in Descemet's membrane since significant increases in fluorescence and resistance to trypsin were noted. These data suggest that the Maillard reaction may, to a small degree, contribute to basement membrane thickening.

Tinnitus.

Tinnitus, a common complaint, reportedly affects more than 37 million Americans. Most often, it is associated with a sensorineural hearing loss in the high-frequency range. Tinnitus, however, is a symptom and not a disease. Complacency about this symptom complex may cause physicians to overlook a severe underlying pathologic process. Patients with unilateral tinnitus, pulsatile tinnitus, fluctuating tinnitus, or tinnitus associated with vertigo should undergo thorough assessment, including elicitation of a complete history, physical examination, and audiologic analysis. In many instances, treatment is effective. Masking of tinnitus, medical therapy, and biofeedback and counseling are some measures that have been used in the management of tinnitus.

Labyrinthitis ossificans: histopathologic consideration for cochlear implantation.

Labyrinthitis ossificans may be a hindrance to cochlear implantation by making electrode insertion difficult. We performed a histopathologic study of 24 temporal bones with labyrinthitis ossificans from multiple causes. The organ of Corti was graphically reconstructed and the degree of obstruction was estimated for each millimeter of the cochlea. Correlations were calculated between the degree of new bone formation and the cause, patient's age and sex, and time from the original temporal bone insult. Our results demonstrate that complete cochlear ossification is rare. The scala tympani in the basal turn of the cochlea is the most frequent area of ossification, regardless of the cause of the labyrinthitis ossificans. Meningogenic labyrinthitis, usually a childhood disease, was associated with the greatest amount of ossification. When ossification resulted from tympanogenic labyrinthitis, the scala tympani was completely ossified near the round window niche in all temporal bones. Neo-ossification of the basal turn associated with otosclerosis was limited to the proximal 6 mm of the scala tympani in all cases. Three temporal bones had a patent round window niche and basal turn, but significant apical and middle-turn ossification. Peripheral sensorineural elements were severely degenerated in the region of the ossification in all specimens, and spiral ganglion cell counts were decreased.