Search PubMed⌕ Search

Biomedical subjects

A Linden

Publications and source records attributed to A Linden.

At least 73 records · Page 4Linked to original sources
PubMed1994

Cardio-respiratory, haematological and biochemical parameter adjustments to exercise: effect of a probiotic in horses during training.

Two randomly distributed groups of thoroughbred horses were compared during a 12-week period for their cardio-respiratory and metabolic adjustment to strenuous exercise, training and detraining. The horses were trained following the same standardized schedule and were regularly investigated using standardized treadmill exercise tests (SET) of increasing speed. After the first SET and during the whole experimental period, a group of 6 horses received a probiotic (Bioracing) once a day while a group of 5 horses received a placebo. All other conditions were similar for both groups. During each SET, the oxygen uptake, carbon dioxide output, tidal volume (inspired volume), respiratory rate and expired minute volume were obtained using 2 ultrasonic pneumotachographs and a mass spectrometer. All the parameters were the mean of the values calculated during the last 20 s of the SET. Heart rate was continuously measured with a polar horse tester. Venous blood was sampled before and after the test and analyzed for various biochemical parameters. In both groups, training induced significant modification in most of the cardio-respiratory parameters, ie peak oxygen uptake, peak carbon dioxide output, respiratory exchange ratio, ventilation/min to oxygen-uptake ratio and oxygen-uptake to heart-rate ratio. After the 3-week detraining period, most of the values were again similar to the pre-training values in both groups. However, the training-induced modifications of most of the cardio-respiratory parameters occurred earlier and were proportionally greater in the probiotic-treated group than in the control. The respiratory coefficient decreased in the control but not in the treated group. All other parameters changed similarly in both groups. This suggests that Bioracing could modify the physiological effects of training by improving some aerobic metabolic capacities for carbohydrate utilization, but that this effect occurs only during training and not during periods of physical inactivity.

Animal Feed↗
PubMed1993

Growth-induced haemodynamic changes in healthy Friesian calves.

This study investigated the pattern of growth-induced haemodynamic changes in normal calves during their first year of life. The central venous pressure (CVP), the right ventricular pressure (RVP), the pulmonary arterial pressure (PAP), the pulmonary capillary wedge pressure (PW), the systemic arterial pressure (SAP) and the cardiac output (CO) were measured in 41 healthy Friesian calves. The heart rate (HR), the stroke volume (SV), the cardiac and stroke indices (CI and SI, respectively), the pulmonary and systemic vascular resistance (PVR and SVR, respectively), the right ventricular and left ventricular work (RVW and LVW, respectively) and their corresponding indices (PVRI, SVRI, RVWI and LVWI, respectively) were also measured or calculated. The cardiac output, SV, SAP, PVRI, SVRI, RVW and LVW increased significantly while the HR, CI, PVR, SVR, RVWI and LVWI decreased significantly with somatic growth. The right-sided vascular pressures did not change significantly. The significant increase in systemic arterial pressure may be due to the simultaneous increase in CO. The high CI observed in the first few weeks of life was attributed to a high metabolic rate and might induce a reduced cardiac pumping reserve in young calves. In consequence, a therapeutic inotropic intervention may have little potential benefit at this age.

Aging↗
PubMed1992

Cardiovascular response to acute hypoxia in double-muscled calves.

Hypoxic-induced pulmonary hypertension is known to be intensive in the bovine species and sometimes leads to pathological cardiac repercussions. On the other hand, doubled-muscled cattle are predisposed to develop hypoxaemia during exercise and with respiratory diseases. Therefore the purpose of this study was to investigate the cardiovascular response to acute hypoxia in double-muscled calves compared with calves of standard conformation. Pulmonary arterial pressure, electrocardiogram and blood temperature were simultaneously recorded, arterial blood was sampled for blood gas analysis and cardiac output was determined in six Friesian calves and six double-muscled calves of the Belgian White and Blue breed(BWB) when breathing air (fractional inspiratory oxygen concentration [FIO2]: 21 per cent) and when breathing a hypoxic gas mixture (FIO2: 10 per cent). All the absolute values of the measured parameters were significantly (P less than or equal to 0.001) different between the two breeds, except heart rate and arterial blood gas values. The pattern of hypoxic-induced decrease in arterial PO2 was similar in the two breeds of calves, suggesting that the pulmonary exchange capacities during hypoxia are no less efficient in double-muscled calves than in calves of standard conformation. Similarly, the percentage of variation of the mean pulmonary arterial pressure from its normoxic to its hypoxic value was the same in the two breeds of calves, suggesting that double-muscled calves are not predisposed to develop a more precocious or more intense pulmonary hypertension for a given level of hypoxaemia. The significantly smaller normoxic and hypoxic cardiac index and stroke index found in BWB compared with Friesian calves was interpreted as a less efficient cardiac function in double-muscled subjects.

Acute Disease↗
PubMed1992

[NMR tomography in plasmacytoma].

In 20 patients with multiple myeloma, the results of MR, x-ray, bone scintigraphy, bone marrow scintigraphy and bone marrow biopsy were compared. MR proved the most sensitive imaging method for the detection of bone marrow infiltration followed by x-ray examinations. Bone marrow scintigraphy and especially bone scintigraphy revealed false-negative results more often. These findings were more impressive by the direct comparison of several investigated regions showing different findings of each imaging method. False-positive results were not found. In 4 patients false-negative results of bone marrow biopsy had to be assumed because of definitely pathological findings by x-ray and MRI.

Aged↗
PubMed1991

Ossicular chain reconstruction: a combined prosthesis with organic and synthetic material.

The surgical techniques to restore the sound pressure transfer mechanism in surgery of chronic otitis media are still in an evolutionary stage. Ossicular interposition is effective and certainly is not controversial. The use of various organic prostheses has been criticized. The prosthesis with a shaft of Teflon and a homograft bone flange is an alternative method which has been successful in our hands.

Bone and Bones↗
PubMed1991

Quantitative buffy coat analysis related to adrenocortical function in horses during a three-day event competition.

This study was carried out to investigate stress induced in a cross-country by measuring plasma cortisol and to compare the changes in cortisol level with the leucocytic changes measured with the quantitative buffy coat (QBC) analysis, which is a new method applicable in field conditions for the evaluation of haematological parameters in horses. Seven healthy horses competing in a national three-day event were investigated. Venous blood was sampled under resting condition, 2 min and 180 min after the completion of the cross-country and analysed for haematological parameters, plasma cortisol, protein and lactate levels. Immediately after the event, there was a significant increase in all values except in the granulocytes (Gr) to lymphocytes-monocytes (LM) ratio. 180 min after the event, all the parameters returned to their resting levels while white blood cells (WBC), Gr and Gr/LM ratio were significantly higher with respect to their resting values. A high correlation (r = 0.82) was found between the relative increase in plasma cortisol levels 2 min after exercise and the relative increase in Gr/LM 180 min after exercise. Therefore it was concluded that the Gr/LM ratio measured 180 min after exercise with the QBC analysis is a reliable index to estimate the plasma cortisol levels measured 2 min after exercise. This new technique could consequently be used in order to evaluate, in field conditions, the exercise-induced stress.

Adrenal Cortex↗
PubMed1991

Validation of the thermodilution technique for the estimation of the cardiac output in the unsedated calf.

The purpose of this study was to establish a standardized protocol in order to obtain accurate and reproducible cardiac output (CO) measurements by the thermodilution technique in the unsedated calf. In 5 healthy calves, the effect of various temperatures, volumes, rates, means and sites of injection of the thermal indicator were tested for their effect on accuracy and reproducibility of CO measurement by the thermodilution technique, the Fick method being used as the standard technique. Five milliliters of an iced 5% dextrose solution per 100 kg body weight constituted the correct amount of thermal indicator. Manual injection of the indicator bolus and/or injection of this bolus through the proximal lumen of a thermodilution Swan-Ganz catheter gave poor results of CO measurements by the thermodilution technique. On the other hand, results of CO measurements were highly reliable when the bolus injection was performed by an ECG-synchronized injection pump and/or through a right atrial catheter with a larger diameter and a shorter length than the classical Swan-Ganz catheter. It was concluded that an iced 5% solution of dextrose (5 ml/100 kg body weight) injected through a right atrial catheter by an ECG-synchronized pump gives the most accurate and reproducible CO measurements by the thermodilution technique in unsedated calves.

Animals↗
PubMed1991

[The early diagnosis of Perthes disease: the value of bone scintigraphy and magnetic resonance imaging in comparison with x-ray findings].

The value of conventional radiology, bone scintigraphy and magnetic resonance imaging (MRI) in the early diagnosis of Legg-Calvé-Perthes disease (LCPD) was assessed. The initial results were compared with the clinical and radiological findings of long-term follow-up in 43 children. Radiological and scintigraphic examination resulted in a relatively high number of equivocal findings (16% and 10%, respectively). MRI findings were less equivocal (3%). Depending on whether such findings were classified as normal or as pathological, the diagnostic accuracy ranged as follows: radiography 88-93%, bone scintigraphy 88-91%, and MRI 97-99%. Therefore, MRI by itself seems to be sufficient to detect or exclude LCPD. The results of this study and the radiation exposure associated with radiography and scintigraphy raise the question whether MRI should be the diagnostic method of choice in patients with suspected LCPD.

Child↗
PubMed1991

[Bone marrow changes in patients with thyroid carcinoma].

In 62 patients with thyroid carcinoma 79 MRI bone marrow examinations and 48 bone marrow scintigraphies were recorded before or following radioiodine therapy, to study the extent of bone marrow expansion. The results of both methods were the same. In 34/79 investigations normal findings were seen, in 18 the bone marrow expanded to the middle third and in 26 to the distal third of the femur. One patient showed bone marrow expansion to the tibia. These results were compared with the following data: histology of tumor, TNM-staging, time passed since thyroidectomy, accumulated doses of radioiodine therapy, results of 131I scintigraphy, hematological changes, thyroglobulin level, age and sex. No significant correlations were found between these and the bone marrow imaging results. Bone marrow changes in patients before radioiodine therapy were similar to those in patients treated with up to 48 GBq 131I. Blind biopsy of the posterior iliac crest in five patients showed slightly pathological reactive changes. In only 2/17 follow-up studies an increase of bone marrow expansion was seen. In 8 patients localized findings indicating malignant infiltration were observed. In 4/8 patients metastases of thyroid carcinoma were known or confirmed by pathological radioiodine uptake and in 2/8 metastatic involvement was assumed because of an increased thyroglobulin level.

Adenocarcinoma↗
PubMed1991

[Retrosternal lymph node metastases in breast cancer: lymphoscintigraphy and magnetic resonance tomography].

In 21 patients with breast cancer (pT1-4, N0, M0) internal mammary lymphoscintigraphy and magnetic resonance imaging (MRI) were performed to evaluate retrosternal lymph node metastases. In 6 patients normal findings of lymphoscintigraphy were confirmed by MRI. In the 15 patients with focal defects seen by lymphoscintigraphy no lymph nodes were found by MRI in 5 in the corresponding area, 5 showed normal-sized lymph nodes (less than 1 cm) and 5 enlarged lymph nodes indicating metastatic infiltration. In addition to internal mammary lymphoscintigraphy MRI may offer the possibility to improve TNM staging in patients with breast cancer.

Adult↗
PubMed1991

[The effect of hyper- and hypothyroidism on the energy metabolism of skeletal muscles--a study using 31P-magnetic resonance spectroscopy].

31P magnetic resonance spectroscopy allows non-invasive evaluation of phosphorus metabolism in man. The purpose of the present study was to assess the influence of hyper- and hypothyroidism on the metabolism of resting human skeletal muscle. The present data show that quantitative measurement of phosphate metabolism by NMR is possible as also demonstrated by other studies. Using a quantitative evaluation method with an external standard, significant differences in the levels of phosphocreatine, adenosine triphosphate, and phosphodiesters were found. In hypothyroid patients a TSH-dependent increase in phosphodiesters and a decrease in adenosine triphosphate and phosphocreatine was observed. In hyperthyroidism a similar decrease in adenosine triphosphate but a considerably higher decrease in phosphocreatine occurred. In the light of the results of other studies of muscle metabolism, these changes appear to be non-specific so that further studies are required to assess the clinical value of such measurements.

Adenosine Triphosphate↗
PubMed1990

[Bone marrow metastases of neuroblastoma: MRT in comparison with bone marrow cytology and mIBG scintigraphy].

Thirteen MRT investigations of the knee region of nine children with neuroblastoma stage IV/III were performed in order to demonstrate bone-marrow metastases. The MRT-findings were correlated with bone-marrow cytology, immunofluorescence, and mIBG-scintigraphy. MRT showed a high sensitivity in demonstrating bone-marrow abnormalities, although bone-marrow aspiration and mIBG-scintigraphy will still be needed to make a specific diagnosis. On the other hand, signs of bone-marrow involvement in MRT investigations without positive findings in bone-marrow cytology and mIBG-scintigraphy may be the first evidence of bone-marrow metastases.

3-Iodobenzylguanidine↗
PubMed1990

Immunoscintigraphic imaging of mIBG-negative metastases in neuroblastoma.

We report a study of seven children with recurrent stage IV neuroblastoma comparing the uptake pattern of 123I-metaiodobenzylguanidine (mIBG) with 99mTc-labeled monoclonal antibody (MAb) BW 575 by the tumor lesions. Immunofluorescence studies of bone marrow had verified specific binding of the antibody to the tumor cells. The majority of tumor sites was detected both by mIBG and MAb scans. However, five of 26 lesions were not detected by mIBG and eight of 26 were false negative by immunoscintigraphy. The false negative lesions by mIBG belonged to five different patients (one of five primary, four of five bone marrow). In conclusion, MAb BW 575 may detect mIBG-negative neuroblastoma sites. The presence of antibody-negative sites suggests the utilization of both scintigraphy methods together.

3-Iodobenzylguanidine↗
PubMed1990

Ventilatory mechanics in healthy calves during helium-oxygen breathing.

The mechanics of breathing was investigated in six healthy calves breathing either air or a mixture of 79% helium and 21% oxygen (He-O2). Intrapleural pressure (Ppl) was measured with an esophageal balloon catheter and transpulmonary pressure was obtained by subtracting the mouth pressure (Pm) from Ppl. Respiratory airflow (V) was measured using a Fleisch pneumotachograph N degrees 3 and tidal volume (Vt) was electronically derived by integrating V with respect to time. Respiratory airflow, Vt, Ppl and Pm were simultaneously recorded while the calves breathed first air (1 min), secondly He-O2 (1 min) and finally air again (1 min). The pulmonary function values were calculated on the tracings and the He-O2 values were compared to the corresponding "air" values. The ventilatory response to resistance unloading was characterized by a significant increase in minute volume exclusively due to an increase in respiratory frequency, while Vt remained unchanged. A decrease of 32% in the total pulmonary resistance (RL) and 16% in the work per litre of ventilation (Wrm/l) were observed when calves breathed He-O2. The effect of the He-O2 on RL and on Wrm/l suggests that, in the bovine species, airflow turbulances in the upper part of the respiratory tract play a significant role in the total airways resistance.

Airway Resistance↗
PubMed1990

[Magnetic resonance tomography of the bone marrow in cancer patients with a solitary area of increased uptake in the bone scintigram].

Solitary abnormalities in bone scintigrams of cancer patients are a finding causing special diagnostic problems. In a prospective study the value of MRI imaging of the bone marrow was to be ascertained when compared to recognized X-ray studies, as a method of clarifying suspect bone scintigraphy findings. 25 cancer patients presenting with a solitary suspect abnormality in bone scintigrams were examined by X-rays and MRI. In 15 patients, MRI showed that metastases were the probable cause of the hot spot. In 7 patients, radiography, the routinely used method to confirm or exclude the presence of metastases, failed to detect these metastases. In the remaining 10 patients other causes of increased activity in the bone scintigrams could be demonstrated, e.g. fracture, degenerative disease, benign tumour. The results were confirmed by biopsy, operation, autopsy or follow-up. Considering the clinical consequences of the diagnosis of bone metastases, we suggest that a bone marrow MRI of the affected region should be performed to clarify the cause of a solitary hot spot in bone scintigrams of cancer patients, especially if X-ray studies are inconclusive.

Adult↗
PubMed1990

Comparison of the adrenocortical response to both pharmacological and physiological stresses in sport horses.

Seven sport horses were investigated to compare physiological and pharmacological stresses on the plasma glucocorticosteroid levels. Venous blood was sampled and analysed for cortisol concentrations before and after each type of stress. The physiological stress was induced by the completion of a cross-country and the pharmacological one, by an intravenous ACTH administration (200 micrograms) in the same horses, one week after the course. Both exercise and ACTH injection induced a highly significant cortisol increase of 79 +/- 0.10% and 160 +/- 0.18%, respectively. The relative plasma cortisol increases due to exercise on the one hand, and due to ACTH administration on the other hand, were correlated with a coefficient of 0.82. It was concluded that the plasma cortisol increase induced by a standardised pharmacological stress could be used in order to predict the exercise-induced stress response.

Adrenal Cortex↗
PubMed1989

[Status of the captopril test in the diagnosis of hypertension].

The place of captopril (C) testing in the screening for renovascular hypertension is still controversial. Baseline and C-stimulated plasma renin concentrations (PRC) were measured in 113 hypertensives, who where referred for the exclusion of secondary hypertension. In addition intravenous digital subtraction angiography (DSA) and a renal scintigraphy were performed. When renal artery disease was revealed by DSA or renin was stimulated the renal arteries were visualized by direct arteriography (and treated by angioplasty if possible). 86 patients underwent each diagnostic test: 21% had renovascular hypertension. Unilateral renal artery stenosis (n = 10) was detected by the captopril test (cutoff values: baseline greater than 40 microU/ml, after C greater than 180 microU/ml, sensitivity 100%). Bilateral renal artery stenosis (n = 8) was missed when the disease was equally severe on either side (sensitivity 50%). The specificity of C testing was 82%, overall sensitivity (uni- and bilateral disease 78%, prevalence 21%, predictive value of the positive test 0.56, predictive value of the negative test 0.93). With i.v.-DSA the renal arteries were technically evaluable in 91% (82/92) of cases. The sensitivity for the detection of all renal artery stenoses was 79% (uni-lateral 100%, bilateral 40%, specificity 97%). The sensitivity of renal scintigraphy for the detection of unilateral renal artery stenoses was 50%, for the detection of bilateral renal artery stenoses 43%, specificity 81%. The present study demonstrates the usefulness of captopril for the detection of unilateral renal artery stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗