[Simultaneous measurement of muscle energy metabolism by MRS and frequency-domain NIR spectroscopy].

The frequency-domain near-infrared spectrometry (NIRS) is capable of measuring the absolute absorption and reduced scattering coefficient of tissue noninvasively. This allows the quantitation of tissue hemoglobin concentration which reflects the balance between oxygen delivery and oxygen utilization of the skeletal muscle. Phosphorus magnetic resonance spectroscopy (31P-MRS) has become a gold standard of noninvasive measurement of human skeletal muscle metabolism. The rate of phosphocreatine (PCr) resynthesis during recovery is an indicator of the rate of oxidative metabolism. The purpose of the present study was the effect of lower intracellular pH (pHi) on PCr and oxygenation recovery. The preliminary results of plantar flexion experiment on a healthy male subject show that both PCr resynthesis and reoxygenation were very much prolonged by severe acidosis (pHi = 6.42).

Treatment of osteonecrosis in the hip of pediatric patients by free vascularized fibular graft.

The purpose of the current study was to review the demographics and etiologies of symptomatic femoral head osteonecrosis in the pediatric and adolescent population and to assess the results of treatment using free vascularized fibular grafting. A group of patients with femoral head osteonecrosis who were treated with free vascularized fibular grafting was reviewed. Patients who were studied were 18 years of age or younger at the time of surgery. Records were examined for demographic data, etiology of osteonecrosis, stage of the disease at time of surgery, and results of treatment including preoperative and postoperative Harris hip scores. Eighty-two pediatric and adolescent patients with osteonecrosis of the femoral head underwent 90 free vascularized fibular grafting procedures. Fifty patients (54 hips) who have been followed up at least 2 or more years (average, 4.3 years) constituted the study group. At the last followup, total hip arthroplasty was performed in seven hips (seven patients) and hip fusion was performed in one hip (one patient). The average Harris hip scores in patients who did not undergo total hip arthroplasty improved from a preoperative average of 55.3 points to 90.2 points at the latest followup. Treatment of patients with osteonecrosis with free vascularized fibular grafting resulted in a lower rate of conversion to total hip arthroplasty or fusion (16%) in pediatric and adolescent patients when compared with conversion to total hip arthroplasty in adults (25%). The quality of life as evidenced by the increased Harris hip scores was improved significantly in this group of pediatric and adolescent patients.

Effects of epinephrine and lactate on the increase in oxygen consumption of nonexercising skeletal muscle after aerobic exercise.

The purpose of this study was to measure O2 consumption of nonexercising skeletal muscles (VO2nonex) at rest and after aerobic exercise and to investigate the stimulant factors of O2 consumption. In experiment 1, we measured the resting metabolic rate of the finger flexor muscles in seven healthy males by 31P-magnetic resonance spectroscopy during a 15 min arterial occlusion. In experiment 2, the VO2nonex of the finger flexor muscles was measured using near infrared continuous wave spectroscopy at rest, immediate postexercise, and 3, 5, 10, 15, and 20 min following a cycling exercise at a workload corresponding to 50% of peak pulmonary O2 uptake for 20 min. We also monitored deep tissue temperature in the VO2nonex measurement area and determined catecholamines and lactate concentrations in the blood at rest and immediate postexercise. VO2nonex at rest was 1.1 +/- 0.1 microM O2/S (mean +/- standard error) and VO2nonex after exercise increased 59.6 +/- 7.2% (p < 0.001) from the resting values. There were significant correlations between the increase in VO2nonex and the increase in epinephrine concentration (p < 0.01), and between the increase in VO2nonex and the increase in lactate concentration (p < 0.05). These results suggest that epinephrine and lactate concentrations are important VO2nonex stimulant factors.

Iron-binding antioxidant potential of plasma albumin.

1. The extracellular proteins caeruloplasmin and transferrin have important antioxidant properties by virtue of the fact that they inhibit iron-dependent free radical production, and ensuing damage to cells. 2. Albumin is a plasma protein which can loosely bind iron, but the redox activity of this iron has not been fully investigated. 3. The ability of albumin to bind iron and to prevent iron-dependent lipid peroxidation in vitro was investigated using liposomes and a rat brain homogenate system. 4. The iron-binding capacity of albumin was found to be substantial, and albumin inhibited lipid peroxidation in a concentration-dependent manner in both systems used. 5. This antioxidant property of albumin may be especially important in the plasma of babies born prematurely, in whom transferrin and caeruloplasmin concentrations are often very low, and in whom non-transferrin-bound iron has been detected in the plasma.

Chromatographic method for the determination of non-transferrin-bound iron suitable for use on the plasma and bronchoalveolar lavage fluid of preterm babies.

1. Non-protein-bound iron has been implicated in the aetiology of chronic lung disease of prematurity. 2. The modification of a method for the measurement of non-transferrin-bound iron in small volumes of plasma and bronchoalveolar lavage fluid from preterm babies is described. 3. The assay runs with a good degree of precision and a lower limit of detection of 0.02 mumol/l. 4. Non-transferrin-bound iron was detected in 50% of plasma samples and 11% of bronchoalveolar lavage fluid samples collected over the first week of life from babies born prematurely.

Factors that influence the elderly to use traditional or nontraditional nutrition information sources.

This study analyzed sociodemographic variables, access to medical care, health status-related variables, and nutrition status-related variables to determine their ability to predict an orientation toward traditional or nontraditional nutrition information sources among aged subjects in Eugene, OR. Data were collected from 165 randomly selected subjects by trained interviewers using face-to-face interviews. Nutritionist orientation was measured by a Traditional/Nontraditional Index (TNT Index) developed for the study. Nutrition knowledge and misinformation, supplement use, and sources of nutrition information were also investigated. Predictors of nontraditional nutritionist orientation were acceptance of nutrition misinformation and male sex (adjusted R2 = .09). For women, predictors of a similar orientation were acceptance of nutrition misinformation, low knowledge of general nutrition information, and low functional health status (adjusted R2 = .19). Mean nutrition knowledge scores were high, with a mean of 4.7 (standard deviation [SD] = 0.8) on a scale ranging from 4 (high) to 8 (low). However, many of the subjects did not list dairy foods (28%) and grains (27%) as necessary in the diet. In addition, belief in certain nutrition myths was widespread. More than 58% were taking one or more supplements (mean = 1.4 supplements per day, SD = 1.98). Physicians were mentioned as most likely sources of nutrition information, with dietitians and health food store personnel mentioned second, indicating the importance of marketing efforts for registered dietitians.

Thermoregulation in babies immediately after birth.

The fall in body temperature that occurs in babies soon after birth is influenced by the baby's weight and its environmental conditions. The rate of oxygen consumption 1 1/2 hours after birth was unrelated to body temperature and only slightly raised, indicating a limited thermogenic capacity. A radiant heater effectively prevented cooling in babies kept with their mothers in the delivery room. Washing soon after birth caused a significant cooling. Healthy term babies were found to have a limited thermogenic response to a cool environment over the first 12 hour of life and efforts to limit heat losses should be concentrated on this period.

Antenatal diagnosis of trisomy 13 with unexpected increase in alpha-feto protein.

A 24-year-old woman who had previously given birth to an infant with Down's syndrome was shown by chromosomal analysis of the liquor amnii to be carrying an infant with trisomy D. Routine examination of serum and liquor alpha-feto protein (AFP) in the antenatal period showed unexpected high levels of both, consistent with a neural tube defect. The fetus, however, did not have evidence of a neural tube defect but had scalp defects which were presumed to have allowed the leakage of AFP from the fetus into the liquor amnii and hance into the maternal serum.