A mechanism for altered flexibility in human skeletal muscle

1. We investigated the effect of a long-term stretching regimen on the tissue properties and stretch tolerance of human skeletal muscle. 2. Resistance to stretch was measured as torque (in N m) offered by the hamstring muscle group during passive knee extension while electromyographic (EMG) activity, knee joint angle and velocity were continuously monitored during a standardized stretch manoeuvre. Seven healthy subjects were tested before and after a 3 week training period using two separate protocols. Protocol 1 consisted of a slow stretch at 0.087 rad s-1 to a predetermined angle followed by a 90 s holding phase. Subjects were brought to the same angle before and after the training period. Protocol 2 was a similar stretch, but continued to the point of pain. 3. During protocol 1 the torque rose during the stretch and then declined during the holding phase. EMG activity was small and did not change significantly during the protocol. No significant differences in stiffness, energy and peak torque about the knee joint were seen as a result of the training. During protocol 2 the angle to which the knee could be extended was significantly increased as a result of the training. This was accompanied by a comparable increase in peak torque and energy. EMG activity was small and not affected by training. 4. It is concluded that reflex EMG activity does not limit the range of movement during slow stretches and that the increased range of motion achieved from training is a consequence of increased stretch tolerance on the part of the subject rather than a change in the mechanical or viscoelastic properties of the muscle.

A framework for the etiology of running-related injuries

The etiology of running-related injury is important to consider as the effectiveness of a given running-related injury prevention intervention is dependent on whether etiologic factors are readily modifiable and consistent with a biologically plausible causal mechanism. Therefore, the purpose of the present article was to present an evidence-informed conceptual framework outlining the multifactorial nature of running-related injury etiology. In the framework, four mutually exclusive parts are presented: (a) Structure-specific capacity when entering a running session; (b) structure-specific cumulative load per running session; (c) reduction in the structure-specific capacity during a running session; and (d) exceeding the structure-specific capacity. The framework can then be used to inform the design of future running-related injury prevention studies, including the formation of research questions and hypotheses, as well as the monitoring of participation-related and non-participation-related exposures. In addition, future research applications should focus on addressing how changes in one or more exposures influence the risk of running-related injury. This necessitates the investigation of how different factors affect the structure-specific load and/or the load capacity, and the dose-response relationship between running participation and injury risk. Ultimately, this direction allows researchers to move beyond traditional risk factor identification to produce research findings that are not only reliably reported in terms of the observed cause-effect association, but also translatable in practice.

Venous thromboembolism and the risk of subsequent symptomatic atherosclerosis

BACKGROUND

Recently, we reported an association between asymptomatic carotid atherosclerosis and venous thromboembolism (VTE) of unknown origin. We hypothesized that patients with VTE of unknown origin would be at a higher risk of developing symptomatic atherosclerosis than patients with VTE induced by known risk factors.

METHODS

To examine this hypothesis, we studied 1,919 consecutive patients followed prospectively after their first VTE episode. The primary outcome was non-fatal and fatal symptomatic atherosclerotic disease in patients with VTE of unknown origin as compared to those with secondary VTE. An independent committee assessed all study outcomes, and adjusted hazard ratios (HR) were calculated using the Cox's proportional hazards model.

RESULTS

After a median follow-up of 48 and 51 months, respectively, at least one symptomatic atherosclerotic complication was detected in 160 of the 1,063 patients (15.1%) with VTE of unknown origin, and in 73 of the 856 (8.5%) with secondary VTE. After adjusting for age and other risk factors of atherosclerosis, the HR for symptomatic atherosclerotic complications in patients with VTE of unknown origin compared to those with secondary VTE was 1.6 (95% confidence intervals; CI: 1.2-2.0). When the analysis was restricted to patients without previous symptomatic atherosclerosis, the HR became 1.7 (95% CI: 1.1-2.4).

CONCLUSIONS

Patients with VTE of unknown origin have a 60% higher risk of developing symptomatic atherosclerotic disease than do patients with secondary venous thrombosis.

Biomechanical differences in soccer kicking with the preferred and the non-preferred leg

The aims of this study were to examine the release speed of the ball in maximal instep kicking with the preferred and the non-preferred leg and to relate ball speed to biomechanical differences observed during the kicking action. Seven skilled soccer players performed maximal speed place kicks with the preferred and the non-preferred leg; their movements were filmed at 400 Hz. The inter-segmental kinematics and kinetics were derived. A coefficient of restitution between the foot and the ball was calculated and rate of force development in the hip flexors and the knee extensors was measured using a Kin-Com dynamometer. Higher ball speeds were achieved with the preferred leg as a result of the higher foot speed and coefficient of restitution at the time of impact compared with the non-preferred leg. These higher foot speeds were caused by a greater amount of work on the shank originating from the angular velocity of the thigh. No differences were found in muscle moments or rate of force development. We conclude that the difference in maximal ball speed between the preferred and the non-preferred leg is caused by a better inter-segmental motion pattern and a transfer of velocity from the foot to the ball when kicking with the preferred leg.

Penicillin in acute otitis media: a double-blind placebo-controlled trial

The effect of peroral penicillin-V (55 mg/kg/day in 7 days) on acute otitis media was studied in 149 children between the ages of 1 and 10 years in a double-blind, placebo-controlled investigation. The parameters of the disease employed were symptom scores for earache, fever and common cold, the use of analgetics, otoscopy, as well as tympanometry. The children were followed-up for 3 months. Penicillin had no effect on fever and common cold, but earache was significantly reduced on the 2nd day of treatment. The acute course of the disease was satisfactory in 69% of the children in the placebo group and in 86% in the penicillin group. In patients with pneumococci or haemolytic streptococci in the nasopharynx, the pain disappeared after 1-2 doses of penicillin, whereas the treatment had no effect in children with Haemophilus influenzae. There was no difference between the penicillin and the placebo groups with regard to the results of otoscopy and tympanometry after 1 week, 1 month and 3 months. No serious complications were observed. It is concluded that an attitude of "masterly inactivity" with regard to the treatment of acute otitis media is justifiable, provided sufficient analgesic treatment is given and also that the patient can be closely followed. As there are still many unanswered questions more controlled investigations are warranted.

Autologous fibrin glue with growth factors in reconstructive maxillofacial surgery

The aim of this paper was to describe a method for the preparation of autologous fibrin glue with platelet growth factors and to report its use with particulate cancellous bone in reconstructive maxillofacial surgery. The fibrin glue is a two-component glue, where the one component is a concentrated fibrinogen solution with platelet growth factors and the other component is a thrombin solution. Both components were produced from the patients own blood, thus making the glue entirely autologous. The glue was prepared from platelet rich plasma separated from 200 ml of the patient's blood prior to the operation. The fibrinogen in the glue was precipitated from the platelet rich plasma by ethanol precipitation at low temperature and separated together with the platelets by centrifugation. Raising the temperature to 37 degrees C redissolved the precipitate. The thrombin solution in the glue was produced from prothrombin precipitated from 10 ml of the platelet rich plasma by lowering the pH and the ionic strength. The precipitate was separated by centrifugation and dissolved in a calcium ion solution. Increasing the pH to neutral value induced activation to thrombin. Preparation of the fibrin glue was performed in the blood bank within 60 to 90 min with the use of standard equipment. The outcome from 200 ml of blood was approximately 8 ml of fibrin glue: 6 ml fibrinogen to be coagulated with 2 ml of thrombin. The glue had a fibrinogen concentration of approximately 12 times the value in platelet rich plasma and the concentration of growth factors was approximately eight times the value in platelet rich plasma. We have used this glue successfully with particulate bone grafts for reconstructive purposes within the oral and maxillofacial field. It might as well be applied to other surgical areas. Whenever larger amount of the glue will be needed, a whole unit of blood may be taken from the patient, and the red cells re-transfused to the patient during or after the operation.

Treatment of nasal polyps with intranasal beclomethasone dipropionate aerosol

In a double-blind trial thirty-five patients with moderately-severe nasal polyposis were treated with intranasal beclomethasone dipropionate aerosol for 3 weeks. The dose given (400 mug/day) had only local effect on the symptoms. Judged by diary card scores the nasal symptoms were reduced to 52% of the pre-trial level for the whole group. Corrected for the placebo effect the percentage was 68. The reduction of symptoms was equally apportioned to the three symptoms, sneezing, nasal secretion and blockage. The treatment was tolerated well, and it is concluded that intranasal treatment with beclomethasone dipropionate aerosol offers most patients with nasal polyps a good response without any risk of systemic steroid side-effects.

Transfusion practice in massively bleeding patients: time for a change?

BACKGROUND AND OBJECTIVES

We identified some fatal cases where massively bleeding patients received inadequate transfusion therapy. The aim of this study was to review and evaluate the transfusion practice in acutely multitransfused patients.

MATERIALS AND METHODS

Patients receiving > 10 units of red blood cells (RBC) within 24 h of admission and 30 blood components within 7 days of admission were reviewed.

RESULTS

Thirty-nine patients were identified, 13 of whom were inadequately transfused (IT) and had a higher mortality (12/13) than adequately transfused (AT) patients 13/26 (P = 0.013). Ten of 13 IT patients developed a microvascular bleed compared to four of 26 in the AT group (P = 0.001) and had a lower platelet count upon arrival at the intensive care unit (40 x 10(9)/l vs. 80 x 10(9)/l, P = 0.024).

CONCLUSIONS

An early balanced transfusion therapy is vital in massively bleeding patients, and a pro-active approach from the blood bank is warranted. We have introduced an acute transfusion package (ATP) consisting of 5 RBC, 5 FFP and 2 PC units, indicated in massively bleeding patients, securing a balanced transfusion therapy.

Simple mucin-type carbohydrates in oral stratified squamous and salivary gland epithelia

Simple mucin-type carbohydrate antigens, T, Tn, and sialosyl-Tn, have been found to be good markers of malignant transformation in several epithelial tissues as a result of incomplete synthesis with precursor accumulation. The T, Tn, and sialosyl-Tn antigens represent the initial, most immature glycosylation of serine and threonine amino acids of proteins. In normal adult cells these structures are generally masked by addition of further saccharides to form more complex structures. We analyzed simple mucin-type carbohydrates in human labial stratified squamous and minor salivary gland epithelia in order to define the glycosylation pattern in normal cells in relation to epithelial differentiation and maturation. A panel of monoclonal antibodies with well-characterized specificity for T, Tn, sialosyl-Tn and the histo-blood group H and A variants hereof were used in immunohistology of sections from 30 individuals with known ABO, Lewis, and secretor status. In stratified epithelium the sialylated T structure was confined to cell membranes of immature basal cells, whereas the H and A variants were observed on cell membranes of more mature parabasal and spinous cell layers. Furthermore, superficial spinous cells produced a fine granular cytoplasmic staining for Tn and sialosyl-Tn antigens. In minor salivary glands mucous cells expressed Tn and sialosyl-Tn as well as the H and A variants in the area of the nucleus, whereas T and the H variant were found in duct cells and unsubstituted T antigen in myoepithelial cells. These results indicate that incomplete synthesis, i.e., deletion of sialyltransferases and/or histo-blood group ABH transferases, may result in accumulation of T, Tn, and sialosyl-Tn antigens in oral epithelia, thus offering a baseline for further studies of changes in premalignant and malignant oral epithelia.

Effect of in vitro X-irradiation on lymphocyte and granulocyte function

Granulocyte transfusions have been complicated by graft-versus-host disease (GVHD) in the recipients. This risk can be eliminated by irradiation of the cell product. The effect of in vitro irradiation on elements of lymphocyte and granulocyte function was therefore studied in order to determine the dose of irradiation which blocked lymphocyte function without affecting the function of granulocytes. Lymphocyte blast transformation after stimulation with mitogens was reduced by 90% after irradiation with 1500 rad and by 97% after 5 000 rad. The response to microbial agents and allogeneic cells was far more radio-sensitive, being completely abolished after irradiation with 1 000 and 500 rad, respectively. Mobility was the function of polymorphonuclear leucocytes (PMN) most affected by irradiation, being slightly but significantly reduced after irradiation with 10 000-20 000 rad. The bactericidal activity was reduced only after irradiation with 40 000 rad or more, while the hexose monophosphate shunt activity and the myeloperoxidase activity were largely unaffected by irradiation with doses of up to 120 000 rad. Hence the results indicate that the irradiation of leucocytes intended for transfusion with a dose of 2 000 rad is likely to prevent GVHD without causing any apparent damage to the PMN.

Can the hamstring muscles protect the anterior cruciate ligament during a side-cutting maneuver?

Because anterior cruciate ligament (ACL) injuries are common in European handball the present study assessed knee joint shear forces to estimate ACL loading in six elite female handball players during a side-cutting maneuver. A pilot investigation in three dimensions showed that peak moments occurred in the sagittal plane at a high velocity. Therefore, analysis of the movement was performed in two dimensions using high-speed cinematography, ground reaction forces, and electromyography (EMG). Film and force plate data allowed for calculation of net joint moments (inverse dynamics), estimates of instantaneous muscle-tendon lengths, contraction velocities, and peak loading of the ACL. During the breaking phase of the maneuver the peak knee joint moment was 239 Nm (99-309), which yielded an ACL-load of 520 N (215-673). The corresponding peak EMG amplitudes for the hamstring muscles were 34-39% of maximum EMG. During the breaking phase the quadriceps muscle contracted eccentrically with a velocity of 216-253% fiber length/s. In contrast, the hamstring muscles contracted concentrically with a velocity of 222-427% fiber length/s. These results suggest that a side-cutting maneuver produces loads that are insufficient to rupture the ACL. Furthermore, the rapid concentric hamstring contraction suggests that even during maximal activation, the ability of the hamstrings to reduce the ACL load is marginal.

Regional cerebral blood flow in chronic alcoholics measured by single photon emission computerized tomography

Regional cerebral blood flow (CBF) was measured by single photon emission computerized tomography of inhaled 133-Xe in 20 chronic alcoholic men. Mean CBF was 51 ml/(100 g x min) compared with 53 ml/(100 g x min) in 20 normals. Reduced cerebellar blood flow correlated both to structural abnormalities seen on CT scan and to cognitive dysfunction. Slight abnormalities of the regional CBF was observed in the alcoholics. They had a higher incidence of regional low flow areas than a control group. Low flow areas were found in frontal and posterior parts of the brain not only in patients with atrophia, but also in patients without CT abnormalities, suggesting neuronal dysfunction. The occurrence of regional low flow areas was associated with the severity of alcoholism, cerebral atrophy and intellectual impairment.

Dynamics of the martial arts high front kick

Fast unloaded movements (i.e. striking, throwing and kicking) are typically performed in a proximo-distal sequence, where initially high proximal segments accelerate while distal segments lag behind, after which proximal segments decelerate while distal segments accelerate. The aims of this study were to examine whether proximal segment deceleration is performed actively by antagonist muscles or is a passive consequence of distal segment movement, and whether distal segment acceleration is enhanced by proximal segment deceleration. Seventeen skilled taekwon-do practitioners were filmed using a high-speed camera while performing a high front kick. During kicking, EMG recordings were obtained from five major lower extremity muscles. Based on the kinematic data, inverse dynamics computations were performed yielding muscle moments and motion-dependent moments. The results indicated that thigh deceleration was caused by motion-dependent moments arising from lower leg motion and not by active deceleration. This was supported by the EMG recordings. Lower leg acceleration was caused partly by a knee extensor muscle moment and partly by a motion-dependent moment arising from thigh angular velocity. Thus, lower leg acceleration was not enhanced by thigh deceleration. On the contrary, thigh deceleration, although not desirable, is unavoidable because of lower leg acceleration.

Assessment of the nasopharyngeal airway. A rhinomanometric and radiographic study in children with adenoids

An assessment of the nasopharyngeal airway in 24 children referred to hospital for adenoidectomy was based on symptoms, radiography and rhinomanometry. The only symptom that was significantly correlated to a small size of the nasopharyngeal airway was Snoring. By radiography, measurement of the airway as well as of the depth of soft tissue of the posterior wall was found well correlated to nasal respiratory resistance which was measured by a new technique. By this, rhinomanometry could be performed in all children down to the age of 5 years. Both radiography and rhinomanometry give valuable parameters for the indication of adenoidectomy.

Mutual pro-drugs of beta-lactam antibiotics and beta-lactamase inhibitors

The principle of combining a beta-lactam antibiotic with a beta-lactamase inhibitor in a single molecule functioning as pro-drug for the two active components is illustrated by the linked esters 3 and 4 in which ampicillin and mecillinam, respectively, are combined with the beta-lactamase inhibitor penicillanic acid sulfone. It is shown that in man these esters are excellently absorbed from the gastro-intestinal tract and after absorption hydrolyzed with simultaneous liberation of the active components. As a result high blood and tissue levels of antibiotic and beta-lactamase inhibitor in a balanced ratio are attained. The advantages of "mutual pro-drugs" over simple combinations are discussed.

A multilevel nonlinear mixed-effects approach to model growth in pigs

Growth functions have been used to predict market weight of pigs and maximize return over feed costs. This study was undertaken to compare 4 growth functions and methods of analyzing data, particularly one that considers nonlinear repeated measures. Data were collected from an experiment with 40 pigs maintained from birth to maturity and their BW measured weekly or every 2 wk up to 1,007 d. Gompertz, logistic, Bridges, and Lopez functions were fitted to the data and compared using information criteria. For each function, a multilevel nonlinear mixed effects model was employed because it allowed for estimation of all growth profiles simultaneously, and different sources of variation (i.e., sex, pig, and litter effects) were incorporated directly into the parameters. Furthermore, variance in-homogeneity and within-pig correlation were introduced to the functions. Inclusion of a variance of power function and a continuous autoregressive process of first order rendered a substantially improved fit to data for all 4 growth functions. The Lopez function provided the best fit to the data set and was used for characterizing mean growth curves for the 3 sexes (barrows, boars, and gilts). It was estimated that the maximum growth rate occurs at 117, 134, and 96 kg of BW for barrows, boars, and gilts, respectively. Hence, the gilts reached their maximum growth rate at an earlier stage in life compared with boars. Mature size of pigs varied systematically with sex and was estimated to be 466, 537, and 382 kg of BW for the barrows, boars, and gilts, respectively. These estimates are significantly affected by the duration of the experimental period, and it is recommended that future studies looking at estimating the mature size in animals are conducted long enough so that the BW visually stabilizes. Furthermore, studies should consider adding continuous autoregressive process when analyzing nonlinear mixed models with repeated measures.

Alcohol consumption, Lewis phenotypes, and risk of ischaemic heart disease

We have previously found an increased risk of ischaemic heart disease (IHD) in men with the Lewis phenotype Le(a-b-) and suggested that the Lewis blood group has a close genetic relation with insulin resistance. We have investigated whether any conventional risk factors explain the increased risk in Le(a-b-) men. 3383 men aged 53-75 years were examined in 1985-86, and morbidity and mortality during the next 4 years were recorded. At baseline, we excluded 343 men with a history of myocardial infarction, angina pectoris, intermittent claudication, or stroke. The potential risk factors examined were alcohol consumption, physical activity, tobacco smoking, serum cotinine, serum lipids, body-mass index, blood pressure, prevalence of hypertension and non-insulin-dependent diabetes mellitus, and social class. In 280 (9.6%) men with Le(a-b-), alcohol was the only risk factor significantly associated with risk of IHD. There was a significantly inverse dose-effect relation between alcohol consumption and risk; trend tests, with adjustment for age, were significant for fatal IHD (p = 0.02), all IHD (p = 0.03), and all causes of death (p = 0.02). In 2649 (90.4%) men with other phenotypes, there was a limited negative association with alcohol consumption. In Le(a-b-) men, a group genetically at high risk of IHD, alcohol consumption seems to be especially protective. We suggest that alcohol consumption may modify insulin resistance in Le(a-b-) men.

DNA sequences flanking the insulin gene on chromosome 11 confer risk of atherosclerosis

The allelic frequency of DNA restriction fragments of a large size class (U alleles) in the polymorphic region flanking the 5'-end of the human insulin gene on chromosome 11 was 2 X 5 times higher in a group of patients with extensive atherosclerosis than in subjects in whom atherosclerosis could not be demonstrated by coronary arteriography and careful clinical examination. The U alleles apparently do not confer risk of atherosclerosis through conventional risk factors such as body weight or blood pressure or levels of blood glucose, triglycerides, cholesterol, or lipoproteins.

Effects of intact glucosinolates and products produced from glucosinolates in myrosinase-catalyzed hydrolysis on the potato cyst nematode (Globodera rostochiensis Cv. Woll)

The potato cyst nematode (Globodera rostochiensis cv. Woll) is responsible for large yield losses in the potato crop, and opportunities for reducing the attack of these plant nematode species are, therefore, important. This study has been devoted to the testing of the in vitro effects on the potato cyst nematode of eight glucosinolates [prop-2-enyl-, but-3-enyl-, (R)-4-methylsulfinylbut-3-enyl-, benzyl-, phenethyl-, 4-hydroxybenzyl-, (2S)-2-hydroxybut-3-enyl-, and (2R)-2-hydroxy-2-phenylethylglucosinolate] as well as the effects of the products of this myrosinase-catalyzed hydrolysis. The glucosinolates were used at three concentrations, 0.05, 0.3, and 1.0 mg/mL, in the presence or absence of the enzyme myrosinase. The effects of the compounds on the mortality were monitored every 8 h for a 72 h period. No effects were found for any of the intact glucosinolates. However, when active myrosinase was included with 1 mg/mL phenethylglucosinolate at pH 6.5, 100% mortality was observed within just 16 h. A similar effect was achieved at the same concentration of benzyl- and prop-2-enylglucosinolates in the myrosinase-containing solutions, although longer exposures were required (24 and 40 h, respectively). The main aglucone products released from the glucosinolates with pronounced effects on the nematodes were shown to be the corresponding isothiocyanates. The results suggest that mixtures of these specific glucosinolates and active myrosinase or autolysis of plant materials containing these enzymes and glucosinolates might be used to control the potato cyst nematode in the soil.

Supercritical fluid chromatography as a method of analysis for the determination of 4-hydroxybenzylglucosinolate degradation products

In the present study analytical and preparative supercritical fluid chromatography (SFC) were used for investigation of myrosinase catalysed degradation of 4-hydroxybenzylglucosinolate (sinalbin). Sinalbin occurs as a major glucosinolate in seeds of Sinapis alba L., in various mustards and other food products. The degradation products were identified and quantified by analysis based on a developed SFC method using a bare silica column. Determinations comprised transformation products of sinalbin, produced both during degradation of isolated sinalbin, and during autolysis of meal from S. alba seeds. The conditions in the developed SFC method were used as basis for the preparative SFC procedure applied for isolation of the components prior to their identification by nuclear magnetic resonance (NMR) spectroscopy. Myrosinase catalysed sinalbin hydrolysis resulted in the reactive 4-hydroxybenzyl isothiocyanate as an initial product at pH values from 3.5 to 7.5 whereas 4-hydroxybenzyl cyanide was one of the major products at low pH values. 4-Hydroxybenzyl isothiocyanate was found to disappear from the aqueous reaction mixtures in a few hours, as it reacted easily with available nucleophilic reagents. 4-Hydroxybenzyl alcohol was found as the product from reaction with water, and with ascorbic acid, 4-hydroxybenzylascorbigen was produced.

Modulation of cytochrome P-450 and glutathione S-transferase isoform expression in vivo by intact and degraded indolyl glucosinolates

Various dietary substances modulate the xenobiotic metabolism and may thereby protect against toxicity and carcinogenicity of food toxins. The effects of pure indolyl glucosinolates, which are present in cruciferous vegetables, on induction of specific cytochrome P-450 (CYP) and glutathione S-transferase (GST) isoforms have not been studied previously. In the present study, glucobrassicin (GB) and neoglucobrassicin (NeoGB) were purified from broccoli by use of a single-column method. Furthermore, a mixture containing 48% GB, 36% NeoGB, and 16% 4-methoxyglucobrassicin was obtained. The modulatory effects of the pure GB, NeoGB, and the mixture on activities and levels of hepatic CYP 1A, 2B1/2, and 2E1 and alpha- and mu-GST isoforms were investigated in male Wistar rats. The indolyl mixture was the most powerful and NeoGB the weakest inducer of microsomal hepatic CYP 1A1 protein and 7-ethoxyresorufin O-deethylase activity. Furthermore, intact indolyl glucosinolates were more powerful inducers than the in vitro myrosinase-degraded indolyl glucosinolates. The hepatic 7-methoxyresorufin O-deethylase activities, but not CYP 1A2 protein, were induced by pure GB, whereas the mixture and NeoGB showed only minor effects. Neither CYP 2B1/2 nor 2E1 was induced by the indolyl glucosinolates. None of the hepatic GST subunits analyzed, rGST A1/2, A3, or M3, was induced significantly by the purified indolyl glucosinolates.

Two versus seven days penicillin treatment for acute otitis media. A placebo controlled trial in children

103 children between 1 and 10 years of age participated in a double-blind placebo-controlled trial testing the effect of penicillin-V, 55 mg/kg/day, for two days versus seven days in acute otitis media. No significant differences could be demonstrated with regard to earache, healing of the tympanic membrane, tympanometry, fever or common cold symptoms. 76% in the group treated for seven days had a satisfactory course of the disease, compared to 71% in the group treated for two days (p greater than 0.1). In spite of the relatively small number of patients, it is concluded that the effect of penicillin for additional five days in acute otitis media after the initial treatment for two days, can at most be marginal. The advantages of a shortened treatment period are several; the authors have outlined a new treatment modality, consisting of masterful inactivity for 8-12 hours, penicillin-V for two days, and myringotomy in refractory cases, after a new evaluation by the otologist. We believe hereby to be able to reduce penicillin consumption in children with acute otitis media to about 15% of the previous level, without increasing the risk of serious complications.

Relationship between stroke volume, cardiac output and filling of the heart during tilt

BACKGROUND

Cardiac function curves are widely accepted to apply to humans but are not established for the entire range of filling of the heart that can be elicited during head-up (HUT) and head-down tilt (HDT), taken to represent minimal and maximal physiological filling of the heart, respectively. With the supine resting position as a reference, we assessed stroke volume (SV), cardiac output (CO) and filling of the heart during graded tilt to evaluate whether SV and CO are maintained during an assumed maximal physiological filling of the heart elicited by 90 degrees HDT in healthy resting humans.

METHODS

In 26 subjects, central blood volume was manipulated with graded tilt from 60 degrees HUT to 90 degrees HDT. We measured SV, CO (Finometer) and cardiac filling by echocardiography of the left ventricular end-diastolic volume (LVEDV; n=12).

RESULTS

From supine rest to 60 degrees HUT, SV and CO decreased 23 ml [confidence intervals (CI): 16-30; P<0.001; 23%] and 0.9 l/min (0.4-1.4; P<0.0001; 14%), respectively, but neither SV nor CO changed during HDT up to 70 degrees . However, during 90 degrees HDT, SV decreased 12 ml (CI: 6-19; P<0.0001; 12%), with an increase of 21 ml (9-33; P=0.002; 16%) in LVEDV because HR increased 3 bpm and CO decreased 0.5 l/min (ns).

CONCLUSION

This study confirmed that SV and CO are maximal in resting, supine, healthy humans and decrease during HUT. However, 90 degrees HDT was associated with increased LVEDV and induced a reduction in SV.

EMG activity of the iliopsoas muscle and leg kinetics during the soccer place kick

The purpose of the study was to develop a method to record intramuscular electromyogram (EMG) from the iliopsoas muscle and to relate this activity to the kinetics during the soccer place kick. Seven skilled soccer players performed 3 maximal velocity place kicks. The kicks were filmed with a high-speed camera (400 Hz) and EMG recordings were obtained from 5 muscles of the kicking leg, including wire electrodes inserted into the m. iliopsoas. The EMG signals were compared to the kinetics of the kicking leg, which were calculated from the digitised film. The results showed hardly any torque reversal about the hip joint before impact. Angular deceleration of the thigh segment did not increase the angular velocity of the shank (work -3.57 to 0.0%). M. iliopsoas was active during the entire kicking motion (average EMG 65.1-100.9%), even in the period when the thigh was decelerating. Wire electrodes can successfully be applied to EMG recordings of fast unloaded movements.