Biomedical subjects

T Spillman

Publications and source records attributed to T Spillman.

8 recordsLinked to original sources

PubMed1992

Menstrual cycle phase affects temperature regulation during endurance exercise.

We investigated whether menstrual cycle phase would affect temperature regulation during an endurance exercise bout performed at room temperature (Ta) of 22 degrees C and 60% relative humidity. Nine eumenorrheic women [age 27.2 +/- 3.7 yr, peak O2 uptake (VO2) 2.52 +/- 0.35 l/min] performed 60 min of cycle exercise at 65% of peak VO2. Subjects were tested in both midfollicular (F) and midluteal (L) phases, although one woman did not show a rise in serum progesterone (P4) that is typically evident 1 wk after ovulation. VO2, rectal (Tre) and skin (Tsk) temperatures, heart rates (HR), and ratings of perceived exertion (RPE) were measured throughout exercise. Sweat loss (SL) was estimated from pre- and postexercise body weight differences. VO2, SL, and Tsk were not affected by menstrual cycle phase. Preexercise Tre was 0.3 degrees C higher during L than during F conditions, and this difference increased to 0.6 degrees C by the end of exercise (P less than 0.01). Compared with F, HRs during L were approximately 10 beats/min greater (P less than 0.001) at all times, whereas RPE responses were significantly greater (P less than 0.01) by 50 min of cycling. No differences in any measured values were found in the subject whose P4 was low in both test conditions. Results indicate that thermoregulation (specifically, regulation of Tre), as well as cardiovascular strain and perception of exercise, was adversely affected during the L phase.

Adult↗

PubMed1992

Maternal respiration and blood gases during aerobic exercise performed at moderate altitude.

We studied whether maternal acid-base status during aerobic exercise performed at moderate altitude is affected by pregnancy. Seven primiparus women were tested at 37 wk gestation and 12 wk postpartum. Subjects were studied at rest, and during two cycle (50 W, 75 W) and two treadmill (67 m.min-1; 2.5% grade, 67 m.min-1; 12% grade) protocols. Exercise bouts lasted 6 min with a 10-min rest between sessions. Minute (VE) and alveolar (VA) ventilation, tidal volume (VT), and ventilatory equivalent for carbon dioxide (VE/VCO2) were significantly (P less than 0.01) greater when exercise was performed during pregnancy. Physiological dead space (VD) was not affected by pregnancy status and did not differ between rest and exercise. Decreases (P less than 0.01) in arterial pH during exercise averaged 0.04 units in both pregnancy and postpartum. Despite similar change in maternal pH, carbon dioxide tension (PaCO2) remained unchanged during exercise at 37 wk gestation but decreased at 12 wk postpartum. Decreases in arterial bicarbonate [HCO3-] associated with exercise were smaller during pregnancy. Our findings indicate that pregnancy did not compromise maternal acid-base status during aerobic exercise.

Acid-Base Equilibrium↗

PubMed1991

Baroreflex function in normal pregnancy.

The sinoaortic baroreflex is one of the primary mechanisms that regulates blood pressure. Decreased baroreflex sensitivity has been reported in preeclampsia. We sought to determine whether pregnancy altered baroreflex sensitivity. From a radial artery catheter, heart rate and mean arterial pressure were recorded continuously onto a polygraph. The ratio of change in heart rate produced per unit of change in mean arterial pressure was calculated as an index of baroreflex sensitivity. Mean arterial pressure responses to incremental infusions of phenylephrine (0.4 to 2.0 micrograms/kg/min) were measured in the same patients at term (n = 9, 38.0 +/- 0.3 weeks) and again 6 to 8 weeks postpartum (n = 7). The results indicated (1) higher baroreflex sensitivity in pregnancy than in the postpartum period (0.9 vs 0.5 beats/min/mm Hg) (p less than 0.007); (2) attenuated vascular responsiveness to alpha-adrenergic stimulation in pregnancy (p less than 0.05); (3) a relationship between vascular responsiveness and baroreflex sensitivity. We conclude that pregnancy is associated with an increase in baroreflex sensitivity and that the attenuated response to phenylephrine is, at least in part, a result of increased baroreflex sensitivity.

Adolescent↗

PubMed1990

Screening antisera for subtype specificity based on immunoblotting of lectin-affinity electrophoresis: application toward alpha-fetoprotein subfractions.

We adapted a method for evaluating monoclonal antibody specificity toward isoforms and examined 29 alpha-fetoprotein (AFP) antibodies from Hybritech. These antibodies were separated by affinity electrophoresis on agarose-containing erythroagglutinating phytohemagglutinin (PHA-E) followed by immunoblotting onto nitrocellulose. Under these conditions, AFP separates into four subfractions: NR (nonreactive with PHA-E), WR (reactive weakly), RS2 (strongly reactive), and RS1 (very strongly reactive). When polyclonal goat anti-AFP control was used as the test antibody, the distribution of amniotic fluid AFP was approximately 50%, 31%, 12%, and 7% for NR, WR, RS2, and RS1, respectively. The distribution for these same bands from the serum of a patient with hepatocellular carcinoma was 39%, 31%, 30%, and 0%; from the serum of a patient with embryonal carcinoma, it was 29%, 38%, 0%, and 33%, respectively. Twenty-six monoclonal antibodies, including the two used in the Hybritech Tandem-E assay for AFP, showed similar distribution, while the remaining three antibodies showed no reactivity to any of the AFP antigens in this system. Although we were not able to demonstrate any specificity of these antisera toward any single AFP isoform, use of this affinity electrophoresis system provides a model for studying isoform specificity of other AFP antibodies and other antibody-antigen systems.

Amniotic Fluid↗

PubMed1989

Central hemodynamic assessment of normal term pregnancy.

Ten carefully screened primiparous patients between 36 and 38 weeks' gestation underwent pulmonary artery catheterization, arterial line placement, and central hemodynamic assessment in the left lateral recumbent position. Studies were repeated in the same patients between 11 and 13 weeks post partum. Compared with the nonpregnant state, there was a significant fall in systemic vascular resistance, pulmonary vascular resistance, colloid oncotic pressure, and colloid oncotic pressure-pulmonary capillary wedge pressure gradient by the late phase of the third trimester (p less than 0.05). Pregnancy was associated with a significant rise in cardiac output and pulse in all patients (p less than 0.05). There was no significant change in pulmonary capillary wedge pressure, central venous pressure, left ventricular stroke work index, or mean arterial pressure. Normally the late phase of the third trimester is not associated with hyperdynamic left ventricular function as assessed by the left ventricular stroke work index/pulmonary capillary wedge pressure ratio.

Adult↗

PubMed1985

Effect of differences in saturation sensitivity of phospholipid stains on clinical predictivity of L/S ratios.

Owing to the importance of the degree of fatty acid side chain saturation in the ability of lecithin molecules to function as surfactant, we assessed the clinical effectiveness of analytical methods which differ with respect to methodologic influences by saturated and unsaturated phospholipids. The lecithin/sphingomyelin ratios, determined with either cupric acetate or phosphomolybdate as the detection reagent, are compared for their abilities to predict respiratory distress syndrome (RDS), transient tachypnea (TTN), or the absence of respiratory difficulty in neonates. A group of 47 amniotic fluids were analyzed from 25 non-problem cases, 13 cases of TTN and 9 cases of RDS. Receiver operating characteristic analysis shows that in our sample population, the measurement of total lecithin for the prediction of neonatal respiratory distress failed to demonstrate an advantage over the measurement of unsaturated lecithin alone.

Amniotic Fluid↗

PubMed1979

Single strand DNA binding of simian virus 40 tumor antigen.

Simian virus 40 T antigen binds to both single and double strand DNA. The single and double strand DNA binding activity of crude T antigen preparations was evaluated by chromatography of the antigen on DNA-cellulose columns. Crude T antigen was retained on both native and denatured DNA-cellulos columns and was eluted from both columns under similar conditions. The interaction of highly purified T antigen with single and double strand DNA was evaluated by competition experiments using a DNA filter binding assay. These experiments showed that T antigen binds preferentially to single strand calf thymus DNA by more than an order of magnitude when compared to double strand calf thymus DNA.

Antigens, Neoplasm↗

PubMed1976

[Tympanometry in chronic otitis media].

We present an analysis of the otological and audiological findings in 63 patients (113 ears) in which a myringotomy for suspected serous otitis media has been performed. In 98 ears (87%) the impedance data correlated with otoscopy. Tympanograms did not give further information than otoscopy alone in 49 patients with reliable pure-tone audiometrical results, whereas tympanograms would have missed 6 out of 78 ears containing fluid and 6 out of 49 ears who improved in hearing following myringotomy and transtympanic tube therapy. We feel, however, that, in patients who are too young or too retarded to be tested audiometrically, tympanometry in combination with otoscopy could eventually be helpful in settling the indication for a myringotomy, since 3 out of 83 ears with middle ear fluid and hearing improvement following transtympanic tube therapy had pathological tympanograms in spite of normal-seeming ear drums.

Audiometry↗