Elastic properties in the circumferential direction in isolated rat small intestine

The aim was to study the passive biomechanical wall properties in the isolated duodenum, jejunum and ileum of the rat. The organ bath contained a Krebs–Ringer solution with 10^-2m MgCl₂ to abolish smooth muscle contractile activity. Stepwise inflation of an intraluminal balloon, in which the cross-sectional area (CSA) was measured, provided the distension stimulus. The circumferential wall stress–strain distributions were computed from steady-state values of these measurements and the unstressed wall thickness was measured in order to evaluate the passive elastic properties. The CSAs measured increased from duodenum to jejunum and to ileum (P<0.001). At the highest applied pressure load the CSA was 16.64±0.46 mm² for the duodenum, 18.70±0.53 mm² for the jejunum and 21.73±0.49 mm² for the ileum. The wall thickness was 0.19±0.01, 0.25±0.01 and 0.28±0.02 mm, in duodenum, jejunum and ileum, respectively (P<0.01). All segments showed stress–strain distributions that were exponential by nature. Applying the function Y=exp(a+bX) gave a median determination coefficient of 0.98 (quartiles 0.96–0.99). The duodenum was significantly stiffer than the two other segments. The values of a and b were 2.03±0.11 and 14.82±1.81, 1.39±0.20 and 13.15±1.42, and 1.13±0.13 and 10.69±0.65 for the duodenum, jejunum and ileum, respectively. The a differed between the duodenum and the other segments (P<0.001), whereas the b differed only between the duodenum and ileum (P<0.005). In conclusion, differences in the luminal CSA, wall thickness and elastic properties were found between the duodenum, jejunum and ileum.     

Simple mechanical-chemical systemic pressure-control device

An implantable mechanical-chemical device was constructed to act as a feedback mechanism in controlling the blood pressure. It consisted of a balloon connected to a rubber catheter ending in a slit valve. Flow-pressure curves were derived fromin vitro testings for three valve thresholds (120, 140 and 170 mmHg). Five fast-acting hypotensive drugs subsequently filled the device during 40 noradrenaline infusions in 25 dogs, with the balloon in the abdominal aorta and the catheter in the inferior vena cava. The results were as follows: (i) Following a short initial increase in systolic aortic pressure, significantly lower (p<0·001) than in control experiments, the device prevented any pressure rise above its threshold. (ii) The time needed for pressure lowering at the device's threshold depended on the drug used being 3·34±0·84 (mean ± s.e. in minutes) for sodium nitroprusside, 5·99±0·96 for phentolamin, 11·63±2·97 for hydralazine, 14·54±2·43 for a-methyl-dopa and 23·32±2·07 for diazoxide.     

Body fat and muscle thickness in Japanese and Caucasian females

Fat and muscle thicknesses were measured at eight sites by B-mode ultrasonography on 36 Japanese (age = 25.9 ± 1.9 years; mean ± SD) and 56 Caucasian females (25 ± 2 years) to compare the distribution of these tissues. The eight sites were the biceps, triceps, forearm, subscapular, abdomen, quadriceps, hamstring, and calf. Hydrostatically determined body density, corrected for residual lung volume, was similar (P > 0.05) for Japanese (1.048 ± 0.008 g · ml^?1) and Caucasians (1.050 ± 0.009 g · ml^?1). However, in part because of their greater body mass, Caucasians had significantly more (P < 0.05) fat mass (FM; 12.5 ± 3.2 kg) and fat-free mass (FFM; 45.1 ± 5.1 kg) compared to the Japanese (FM = 11.1 ± 2.3 kg, FFM = 38.0 ± 3.5 kg). From the results of a subsample analysis of a group matched for stature and body mass, Japanese women had a greater abdominal fat thickness than Caucasians, but had less fat thickness at the triceps and hamstring sites. Caucasians had greater muscle thicknesses than Japanese at all sites except for abdomen, hamstring, and calf. The ratio of fat thickness to FM · stature^?2 was higher on the trunk (P < 0.001) in Japanese (6.650 ± 1.721 mm³ · g^?1 × 10³) than in Caucasians (4.713 ± 1.441 mm³ · g^?1 × 10³). The ratio of muscle thickness to FFM · stature² was higher (P < 0.001) in Caucasians than in Japanese at the upper extremity and trunk sites. These results suggest that the distribution of subcutaneous fat might be specific to ethnic origin, and that Japanese women have less muscle development than Caucasians even when matched for stature and body mass. © 1994 Wiley-Liss, Inc.     

正常大鼠不同动脉血管应力-应变分布的比较

通过充压实验和无载荷状态及零应力状态,我们研究了16只雄性大鼠的胸主动脉、腹主动脉、左颈总动脉、左股动脉和左肺动脉的形态学和应力－应变分布特征,并比较了不同血管间的差异。结果表明,血管的内外周长、管壁和管腔面积、管壁厚度、管壁厚度与内半径之比以及在不同压力负荷下血管外直径的变化,五条动脉之间有显著差异（P＜0.01）。展开角在肺动脉最大,而胸主动脉最小（P＜0.01）。残余应变绝对值和残余应变梯度在股动脉最大,而在胸主动脉最小（P＜0.01）。应力－应变关系分析证明,在周向上,股动脉最硬;在轴向上,胸主动脉最硬。而在这两个方向上,肺动脉最软。本实验表明,无论在形态学指数方面,还是在生物力学特征方面,五条动脉血管间都有显著差异。     

容量负荷和压力负荷型心脏肥大大鼠模型的建立及评价

目的： 通过建立压力负荷型和容量负荷型心脏肥大大鼠模型，比较各种评价大鼠心脏结构和功能的方法。 方法： 采用腹主动脉-下腔静脉造瘘法和主动脉缩窄法分别复制容量负荷型和压力负荷型心脏肥大大鼠模型，应用超声心动图、血流动力学检测、心脏称量以及组织切片等多种方法评价心脏结构和功能。 结果： 手术组模型心脏重量均明显大于假手术组。动静脉瘘手术组1周时左心室内径及容积均明显大于假手术组［（0.67±0.03）cm vs （0.60±0.20）cm, （0.69±0.10）mL vs （0.50±0.04）mL，P<0.01］，相对室壁厚度 (RWT) 在手术组明显小于假手术组（0.46±0.05 vs 0.55±0.05，P<0.01）；主动脉缩窄手术组1周时室间隔厚度及左室后壁厚度明显大于假手术组［（0.20±0.03） cm vs （0.16±0.02）cm，P<0.01; （0.20±0.03）cm vs （0.16±0.02）cm，P<0.01］，RWT明显大于假手术组（0.71±0.17 vs （0.56±0.12，P<0.05）， +dp/dtmax明显增加(4 886±1 304 vs 3 674±325，P<0.05)。 2周时上述参数变化更为显著。 结论： 腹主动脉-下腔静脉造瘘和主动脉缩窄方法成功复制了容量负荷型和压力负荷型大鼠心脏肥大模型，通过超声心动图和血流动力学检测可较全面地评价心脏结构和功能变化，其中RWT是两种模型都敏感的指标。     

Usefulness of sodium chloride as a nondiffusible indicator in the measurement of extravascular lung thermal volume in dogs

The authors examined the usefulness of sodium chloride as a nondiffusible indicator during the first passage through dogs' lungs, before and after increased-permeability pulmonary oedema produced by an intravenous injection of alloxan. With an injection of a mixture of ice-cold 3 per cent sodium chloride and indocyanine green dye (a nondiffusible reference indicator), the authors simultaneously recorded three dilution curves from the aortic root: dye dilution, thermal and blood electrical conductivity dilution curves in six dogs. The mean transit time of sodium chloride in the conductivity dilution curve was significantly different from, but fairly equal to, that of indocyanine green dye (6·2±1·4 s (mean±SD) against 6·5±1·4s(p<0.01) in the baseline period, and 7·6±1·9 s against 8·4±2·1 s (p<0·01) in the oedema period, respectively). The calculated extravascular lung thermal volume with the thermal and conductivity dilution method (Y, ml kg⁻¹) correlated well with the gravimetrically determined extravascular lung mass in a total of 12 dogs, including six other dogs without intervention (x, g kg⁻¹) (y=0·72x±3·03, r=0·96). The authors conclude that sodium chloride is useful as a nondiffusible indicator in the first passage through the lungs, and that the thermal and conductivity dilution method is also useful for measuring extravascular lung water mass.     

Measurement of aortic compliance from the transthoracic admittance plethysmogram in the living dog

An attempt was made to measure the compliance and elastic modulus of the thoracic aorta from simultaneous recordings of the transthoracic admittance plethysmogram and intra-aortic pressure in living dogs. Initially, the compliance values determined by this method were correlated with those measured from the volume-pressure relationships in three different silicone-rubber tubes; these two groups of values were consistent with each other within the error range of ±10%. The mean value of the compliance of the thoracic aortae in four normal dogs (13–15 kg) measured by this method was 0·00387±0·00100 ml/mmHg cm. The elastic modulus E and velocity v of the pulse wave were calculated from this value; E=2·71±0·79×10⁵ dN/m² and v=4·52±2·44 m/s. These data were compared with those reported previously by other investigators. Taking simplicity, safety and practicability into consideration, it was concluded that this method would only be useful in clinics for the rough estimation of the elastic properties of the thoracic aorta.     

Wave-velocity in the proximal aorta

The wave velocity in the ascending aorta has been measured by 2 methods; (1) from the transit-time of the wave front between 2 points (the wave-front velocity) and (2) from the mean value of the phase shift of the harmonic components of both pressure waves (mean phase velocity). Close agreement was found between values obtained by both methods. With mean arterial pressure (M.A.P.) in the range 90–120 mm Hg the velocities recorded were (1) wave-front velocity, 4·04±(S.E.M.)0·14 m/s; (2) mean phase velocity, 3·98±0·12 m/s. With an electromagnetic flow probe on the ascending aorta the velocity was 3·98±0·09 m/s. Mean phase velocities were based on the values at frequencies above 2 Hz as wave reflection causes a large increase in measured phase-velocity below this frequency. Decrease in M.A.P. below 100 mm Hg produced no significant change in wave-velocity; above 100 mm Hg there was an increase in velocity to 5·6 m/s with a M.A.P. of 160 mm Hg. The wave-velocity in the ascending aorta is somewhat lower than that in the thoracic aorta.     

Variations in local elastic modulus along the length of the aorta as observed by use of a scanning haptic microscope (SHM)

Variations in microscopic elastic structures along the entire length of canine aorta were evaluated by use of a scanning haptic microscope (SHM). The total aorta from the aortic arch to the abdominal aorta was divided into 6 approximately equal segments. After embedding the aorta in agar, it was cut into horizontal circumferential segments to obtain disk-like agar portions containing ring-like samples of aorta with flat surfaces (thickness, approximately 1 mm). The elastic modulus and topography of the samples under no-load conditions were simultaneously measured along the entire thickness of the wall by SHM by using a probe with a diameter of 5 μm and a spatial resolution of 2 μm at a rate of 0.3 s/point. The elastic modulus of the wall was the highest on the side of the luminal surface and decreased gradually toward the adventitial side. This tendency was similar to that of the change in the elastin fiber content. During the evaluation of the mid-portion of each tunica media segment, the highest elastic modulus (40.8 ± 3.5 kPa) was identified at the thoracic section of the aorta that had the highest density of elastic fibers. Under no-load conditions, portions of the aorta with high elastin density have a high elastic modulus.     

MIB1, A PROMISING MARKER FOR THE CLASSIFICATION OF CERVICAL INTRAEPITHELIAL NEOPLASIA

Formalin-fixed and paraffin-embedded tissue specimens of normal and dysplastic cervical epithelia (five CIN1, seven CIN2, five CIN3, and five normal) were assessed by an immunoperoxidase technique, using the monoclonal antibody MIB1, regonizing a formalin-fixation-resistant epitope on the cell proliferation-associated Ki-67 antigen. An image analysis system was used to measure four parameters associated with proliferative activity: the Ki-67 labelling index (LI), the number of Ki-67-positive nuclei per unit length of basement membrane, and the maximum value and 90th percentile of the relative distances of Ki-67-positive nuclei from the basement membrane. All these four proliferation-related parameters were highly correlated with the grade of dysplastic change in the epithelium (0·90< r <0·97, p <0·0001). The best correlation was found for the 90th percentile of the relative distance and with this parameter all CIN lesions could be correctly classified. The means and standard deviations of the Ki-67 LIs in normal epithelium, CIN1, CIN2, and CIN3 lesions were 0·07±+0·03, 0·16±0·03, 0·25±0·06, and 0·39±0·06, respectively. These findings support the theory that CIN involves a progressive dysfunction of the proliferative activity of cervical epithelial cells. Image analysis of MIB1 is a promising alternative method for the objective, reproducible, and reliable classification of dysplastic changes in cervical epithelium.     

Response of the electric activity in the human stomach to water and a solid meal

The gastric electric activity paces the contractions of the stomach and can be measured noninvasively using surface electrodes placed on the abdomen. In this paper, response of the gastric electric activity to water and a solid meal was investigated using surface electrodes. Applying an improved recording technique, power spectral analysis and statistical analysis methods, the gastric electric activity in preprandial, postwater and postprandial states was measured and analysed from ten healthy volunteers. To more convincingly show the effect of water and the solid meal on the gastric slow wave and gastric motility, simultaneous recordings of the cutaneous EGG and manometric activities in the stomach were performed in three gastroparetic patients. It was found that water does not induce contractions of the stomach, but the gastric slow wave amplitude increases (p<0·05) and frequency decreases (p<0·05). The solid meal results in an increase in both the amplitude (p<0·01) and the frequency (p<0·02) of the gastric slow wave. It appears that the postprandial EGG amplitude increases because of a combination of stomach contractions and gastric distension bringing the stomach closer to the recording electrodes. The slow wave frequency, however, correlates well with stomach contractions.     

Spatial variation of aortic wall oxygen diffusion coefficient from transient polarographic measurements

Polarographic current transients following a voltage step (turn-on transient) were measured with bare cathodes (25 μm diameter) and shallowly recessed oxygen microelectrodes (<5μm diameter). Except for the initial part of the current transient, the experimental measurements were in excellent agreement with simple models in the literature, which predict an inverse relationship with . Turn-on transients were measured in aqueous solutions with known physical properties, and in aortic wall tissue from three different species (n=6 rabbits, n=3 dogs, and n=1 miniature pig). Oxygen diffusion coefficients (D) were determinedin vitro by comparing time constants measured by the same microelectrode in saline and in strips of aortic wall tissue at 37°C. On the inner side (endothelium and intima) of the aorta, D averaged (±S.E.) 7.0 (±0.8)×10⁻⁶ cm²/s in 6 rabbits, 6.4 (±1.0)×10⁻⁶ cm²/s in 3 dogs, and was 4.6×10⁻⁶ cm²/s in the pig. On the adventitial side, D was 9.5×10⁻⁶ cm²/s in 1 rabbit, 11.4 (±1.2)×10⁻⁶ cm²/s in 3 dogs, and 8.1×10⁻⁶ cm²/s in the pig. For every aortic strip on which D was measured from both sides, D for the inner wall was always lower, overall by a little more than one third (p<0.001). The lower D on the endothelial side may limit oxygen transport to the vascular wall and play a role in atherogenesis.     

Heart rate variability as an index of autonomic imbalance in patients with recent myocardial infarction

Autonomic nervous activities are estimated in three groups of patients; Group A consists of patients who had experienced myocardial infarction (MI) within 2–6 weeks before the tests; Group B consists of patients who had MI more than one year previously; Group C consists of matched controls, free of cardiac disease. Autonomic activity is estimated using postural effects on heart rate variability (HRV): a sympathetic activity index is defined as HRV power within a low frequency band (0·04–0·12 Hz) in the tilt position and a parasympathetic activity index is defined as HRV power in a high frequency band (0·18–0·28 Hz) in the supine position. Results show that, relative to controls, Group A patients have reduced parasympathetic activity index (5+3 against 13+8, normalised units; p<0·05) and an increased ratio of sympathetic to parasympathetic activity (17+17 against 4+2; p<0·05). Group B is not significantly different from Group A or C. The period of 2–6 weeks post-MI thus appears to be characterised by depressed parasympathetic nervous activity which can be measured using HRV analysis.     

Lowered microvascular vessel wall oxygen consumption augments tissue pO<Subscript>2</Subscript> during PgE1-induced vasodilation

Continuous infusion of intravenous prostaglandin E1 (PgE1, 2.5 μg/kg/min) was used to determine how vasodilation affects oxygen consumption of the microvascular wall and tissue pO₂ in the hamster window chamber model. While systemic measurements (mean arterial pressure and heart rate) and central blood gas measurements were not affected, PgE1 treatment caused arteriolar (64.6 ± 25.1 μm) and venular diameter (71.9 ± 29.5 μm) to rise to 1.15 ± 0.21 and 1.06 ± 0.19, respectively, relative to baseline. Arteriolar (3.2 × 10⁻² ± 4.3 × 10⁻² nl/s) and venular flow (7.8 × 10⁻³ ± 1.1 × 10⁻²/s) increased to 1.65 ± 0.93 and 1.32 ± 0.72 relative to baseline. Interstitial tissue pO₂ was increased significantly from baseline (21 ± 8 to 28 ± 7 mmHg; P < 0.001). The arteriolar vessel wall gradient, a measure of oxygen consumption by the microvascular wall decreased from 20 ± 6 to 16 ± 3 mmHg (P < 0.001). The arteriolar vessel wall gradient, a measure of oxygen consumption by the vascular wall, decreased from 20 ± 6 to 16 ± 3 mmHg (P < 0.001). This reduction reflects a 20% decrease in oxygen consumption by the vessel wall and up to 50% when cylindrical geometry is considered. The venular vessel wall gradient decreased from 12 ± 4 to 9 ± 4 mmHg (P < 0.001). Thus PgE1-mediated vasodilation has a positive microvascular effect: enhancement of tissue perfusion by increasing flow and then augmentation of tissue oxygenation by reducing oxygen consumption by the microvascular wall.     

Effect of indomethacin in vivo and PGE2 in vitro on MTAL Na-K-ATPase of the rat kidney

We have previously shown that prostaglandin synthesis inhibition in rats which reduces urinary excretion of PGE₂ and sodium, is associated with increased Na-K-ATPase activity in renal medulla. To further characterize this interaction studies were performed in isolated segments of medullary thick ascending limb of Henle's loop (MTAL) in rats. The effect of pretreatment with indomethacin in vivo and incubation with PGE₂ in vitro on MTAL Na-K-ATPase activity was studied. Pretreatment of rats with indomethacin increased Na-K-ATPase of the MTAL from 37.2±2.0×10⁻¹¹ mol/mm/min in controls to 62.7±2.2 (p<0.001) while Mg-ATPase was only slightly decreased. Incubation of MTAL Na-K-ATPase from indomethacin pretreated rats with increasing concentration of PGE₂ in vitro dose dependently inhibited MTAL Na-K-ATPase activity with no effect on Mg-ATPase. Baseline Na-K-ATPase was 62.7±2.2 in MTAL from indomethacin pretreated rats and decreased to 36.9±1.4 (p<0.001) with 1 uM of PGE₂, to 26.5±2.3 (p<0.001) with 10 uM PGS₂ and to 22.0±1.0 (p<0.001) with 100 uM PGE₂. 100 uM PGE₂ in the incubation medium inhibited MTAL Na-K-ATPase of intact rats from 37.2±2 to 21.3±1.2 (p<0.001) and completely abolished the indomethacin induced increase in MTAL Na-K-ATPase. The results of this study show stimulation of MTAL Na-K-ATPase by pretreatment with indomethacin in vivo and, direct inhibition of MTAL Na-K-ATPase by PGE₂ in vitro. These findings suggest that the increase in MTAL Na-K-ATPase induced by pretreatment with indomethacin may stem directly from PGE₂ depletion. These observations are consistent with direct inhibitory effect of PGE₂ on Na reabsorption in the MTAL.     

Serum cytokine and chemokine profiles in patients with myasthenia gravis

Myasthenia gravis (MG) is an autoimmune‐mediated inflammatory disease of the neuromuscular junction. Previous studies of animal MG models have suggested important roles of cytokines in MG pathogenesis, but adequate studies on cytokines in human MG are lacking. Using a multiplex suspension array system, we measured the serum levels of 27 cytokines/chemokines in 47 anti‐acetylcholine receptor antibody‐positive patients with MG and 20 normal controls (NC) to investigate the contribution of cytokines/chemokines toward MG pathogenesis. Correlations between clinical parameters and cytokine/chemokine levels in patients with MG were also examined. The serum levels of interleukin (IL)‐15 (mean ± standard deviation: 6·85 ± 6·97 pg/ml) and vascular endothelial growth factor (VEGF) (96·21 ± 71·60 pg/ml) significantly increased, whereas IL‐4 levels (3·57 ± 0·86 pg/ml) decreased in patients with MG compared with NC (IL‐15: 4·42 ± 1·55 pg/ml; VEGF: 63·51 ± 32·95 pg/ml; IL‐4: 4·15 ± 0·81 pg/ml, P < 0·05). In addition, eight cytokines (IL‐4, IL‐8, IL‐15, eotaxin, macrophage inflammatory protein‐1α, macrophage inflammatory protein‐1β, VEGF and IL‐1b) were significantly changed among MG patients with thymoma, MG patients without thymoma and NC (P < 0·05). Some cytokines, such as IL‐4, IL‐15, and VEGF, may play roles in the pathogenesis of MG.     

Characteristics of cardiac period responses to prolonged vagal stimulation in dogs

In 13 dogs anaesthetised with a-chloralose and urethane, and β-blocked with propranolol, the sensitivity of both the left and right cervical vagi was tested with constant-current electrical stimulation at 10 Hz. All 17 active vagi were stimulated for 60 s with supramaximal constant-current pulses at frequencies between 2·5 and 12·5 Hz. In all 17 vagi tested, statistically significant (p<0·0001) linear relationships were found between the vagal stimulus frequency and (i) the steady-state bradycardia, (ii) postvagal tachycardia and (iii) the slope of the response at the onset and termination of stimulation. Postvagal tachycardia was also correlated to the preceding bradycardia and to the slope of the response at the end of stimulation. In all 13 experiments and over 70 responses the steady-state bradycardia was highly correlated (r=0·9382) to the slope at the onset of stimulation. A simple model describing the release, hydrolysis and effect of ACh at the SA node is presented, which predicts the experimental results obtained and gives the average time constant for the hydrolysis of ACh at the cardiac pacemaker as 1·76±0·14 s (p<0·01).     

Avidity of thyroglobulin antibody in sera from patients with Hashimoto's thyroiditis with different thyroid functional status

The mechanism of disease progression in Hashimoto's thyroiditis (HT) is still unclear. Thyroglobulin antibody (TgAb) is a diagnostic hallmark of HT. The aim of our study was to evaluate the avidity of TgAb in sera from HT patients with different thyroid functional status. Sera from 50 patients with newly diagnosed HT were collected and divided into three groups according to thyroid function: patients with hypothyroidism (H, n = 18), subclinical hypothyroidism (sH, n = 18) and euthyroidism (Eu, n = 14). Titres and avidity of TgAb were determined by enzyme‐linked immunosorbent assays (ELISAs). Avidity constant (aK) was determined as the reciprocal value of the thyroglobulin molar concentration in the liquid phase resulting in 50% inhibition of TgAb binding to thyroglobulin in solid‐phase ELISAs. The titres and aK of TgAb were performed using log‐transformation, and expressed as lgT and lgaK, respectively. Mean lgT of TgAb in sera was 4·19 ± 0·60 in H, 3·77 ± 0·63 in sH, and 3·29 ± 0·64 in Eu, respectively. The median avidity of TgAb was 2·30 × 10⁹ in H, 8·80 × 10⁸ in sH, 2·00 × 10⁷ in Eu, respectively. lgT and lgaK of TgAb were at significantly lower levels in Eu than in sH and H (P < 0·05). Correlation was found between lgT and lgaK (r = 0·594, P < 0·05). lgaK was also related to TSH (r=0·308, P < 0·05). Our study indicated that patients with high‐avidity TgAb might be at high risk of developing subclinical, even to overt, hypothyroidism.     

Comparison of the histochemical and contractile properties of human triceps surae

The purpose of the study was to compare the contractile properties determined from an electrically stimulated twitch with histochemically determined fibre type parameters of the human triceps surae. Muscle samples were obtained from the medial head of the gastrocnemius of ten male athletes. Ages ranged from 20 to 29 years. Muscle samples from the belly of the medial gastrocnemius muscle were obtained using the needle biopsy technique. The samples were treated histochemically for myosin ATPase to classify the fibres as either slow twitch (ST) or fast twitch (FT) and to determine fibre areas. Surface electrical stimulation was used to determine muscle twitch parameters. The contractile variables of the muscle twitch were latency (L), time to peak force (TPF), peak force (PF), half-contraction time (1/2 CT) and half-relaxation time (1/2 RT). Backward elimination procedures for dependent variables were used to determine which contractile properties best represented the histochemical profile of the muscles. Prediction formulas were developed for FT and ST percentages (R²=0·98, p<0·001), relative area percentage (R²=0·87, p<0·001), and ST area (R²=0·85, p<0·01). It was concluded that the use of the electrotensiometer (ETM) protocol was a valid testing procedure when studying physiological relationships of histochemical properties in intact human skeletal muscle. Protected by patent no. 4 688 581.