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Biomedical subjects

A Berg

Publications and source records attributed to A Berg.

At least 253 records · Page 14Linked to original sources
PubMed1987

[Effect of vitamins and iron on performance and recovery in humans and in sports anemia].

In sports, vitamins along with minerals, particularly iron, and the energy nutrients such as carbohydrates, are considered especially important. Frequently single or multiple vitamins in combination with other active substances such as iron, other minerals or carbohydrates are administered. In sports, vitamins are added to carbohydrate mixtures or electrolytes enriched with vitamins are offered and frequently used. There is no doubt that due to the numerous effects of vitamins, a connection must exist between the vitamin status and athletic performance capability. It can be concluded that vitamin deficiencies have a negative effect on physical and mental performance. The release of energy can only attain its maximum output when the organism has the required substances at its disposal. Iron is of central importance among these active substances, since its presence in haemoglobin is essential for the transport of oxygen and carbon dioxide, makes it possible for myoglobin to function as an oxygen supply depot and guarantees the functioning of internal respiration in the respiratory chain and various key enzymes. Muscle training increases not only the respiratory chain but also several other iron-rich enzymes. This makes even more astonishing the fact that a variety of recently published articles report on iron deficiency among athletes. The effect of the iron deficiency with anaemia (sports anaemia) is manifest in a reduction of aerobic capacity with an increase in lactate acidosis, greater fatigue, loss of appetite, muscular cramps and vasomotor disturbances.

Anemia, Hypochromic↗
PubMed1987

Influence of symptom-limited stress on blood lactate behaviour in coronary heart disease (CHD) patients.

In order to document the possible influence of stress limiting factors (STLF: chest pain, ST-segment depression) on exercise-induced blood lactate increase in CHD patients (post myocardial infarction) 88 males were examined in a stepwise bicycle stress test. Blood lactate samples were drawn at the end of each stress step. The patients were divided into 2 groups without (n = 45) and with (n = 43) STLF, higher blood lactate concentrations, however, were only observed in relation to the exercise intensity reached at the end of the stress test. Neither the symptom chest pain nor the degree of ST-depression showed a significant influence on the physical performance capacity and the lactate concentration at the anaerobic threshold. Nevertheless, a physical performance capacity above 1 W/kg seems to be necessary to reach the anaerobic threshold level. When the lactate measurement is used in CHD patients, the influence of age on the maximum lactate concentrations must be considered.

Aged↗
PubMed1987

Synthesis, isomerism and characterization of iopentol.

The synthesis of iopentol is described, and the IR, NMR and FAB MS data of the compound are discussed. Iopentol exists as a mixture of several diastereomers and conformers. This topic is discussed in some detail. The kinetics of the isomerization from pure exo-iopentol to an equilibrium mixture of exo- and endo-iopentol is measured by HPLC and 1H NMR spectroscopy. At 40 degrees C the endo:exo ratio is calculated from the HPLC experiments to be 0.26. The time it takes endo-iopentol to reach half of its equilibrium concentration, and the equilibration time are calculated to be 0.8 h and 5.0 h, respectively. Iopentol may exist as exo/endo pairs of four racemates. Neither GC, HPLC, IR nor high field NMR spectroscopy were suited to reveal the diastereomeric composition of the product.

Contrast Media↗
PubMed1987

Synthesis, analysis and toxicity of some compounds which may be formed during the synthesis of iopentol.

The process developed for the synthesis of iopentol consists of several steps. Nine possible impurities from the synthesis of iopentol have been synthesized and one has been isolated from iopentol mother liquor. These substances have been analysed by HPLC methods developed for routine control of iopentol bulk substance. Capacity factors have been calculated for each compound which relate its position in the chromatogram to iopentol. Some of the synthesized compounds have never been found in iopentol and their toxicities have therefore not been determined. Approximate intravenous LD50 values in mice have been determined for the remaining compounds. Taking into consideration these results and the small quantities in which the impurities are present, it is unlikely that they will affect the safety of the final product.

Animals↗
PubMed1987

Mortality in systemic lupus erythematosus.

Many factors influence survival in systemic lupus erythematosus (SLE). Earlier diagnosis and advances in treatment have led to improved survival. In an attempt to establish meaningful survival statistics for patients with SLE, a group of 9 medical institutions formed the Lupus Survival Study Group. We review their data and particularly the data from the State University of New York Health Science Center at Brooklyn, NY.

Follow-Up Studies↗
PubMed1987

Is intrauterine growth retardation a risk factor for child abuse?

A case-control study was conducted to determine whether infants with intrauterine growth retardation are at an increased risk of child abuse. Case children were those who had been born at Yale-New Haven Hospital and were reported to the hospital's child abuse committee because they had been physically abused. For each case, one control child was chosen from the hospital's log of births and matched to the case child by age, gender, race of the mother, method of payment for the hospitalization, and the provider of the child's health care at the time of birth. Infants were defined as having intrauterine growth retardation if they had either a ponderal index or a birth weight that was less than the tenth percentile for gestational age using the Kansas City or Denver growth standards. We identified 117 case-control pairs that met those criteria. The matched odds ratios for each of the four definitions of intrauterine growth retardation were less than one, indicating that infants with intrauterine growth retardation are at a decreased risk of abuse. The matched odds ratio for a low ponderal index according to the Kansas City standard was 0.4 (95% confidence interval 0.19, 0.83). This result was not affected by such possible confounding factors as the mother's age. We conclude that infants with intrauterine growth retardation are not at an increased risk and may be at a decreased risk of physical abuse.

Child↗
PubMed1986

Apolipoprotein profile in healthy males and its relation to maximum aerobic capacity (MAC).

In order to document possible variations of apolipoproteins in relation to the maximum aerobic capacity, 36 healthy young males of different aerobic performance were examined and the serum concentrations of apolipoprotein A-I, A-II, B, C-II, C-III, E investigated. In contrast to all other lipoproteins, significant differences between the endurance-trained and control subjects could be found in the apo A-I concentrations only (1025 +/- 92 vs 1456 +/- 179 mg/l, p less than 0.001). In addition, the apolipoprotein A-II, B, C-II, C-III, E concentrations correlated neither with the maximum aerobic capacity values nor with the relative body weight of the subjects.

Adolescent↗
PubMed1986

Preparative liquid chromatography in the field of X-ray contrast agents.

The use of preparative liquid chromatography (LC) for the effective purification of potential X-ray contrast agents or intermediates is described. Pure products in grams to kilogram quantities have been obtained by reversed-phase preparative LC of highly water-soluble non-ionic compounds, a weak aliphatic carboxylic acid and an isophthalic acid derivative. The mobile phases used were mixtures of methanol-water alone or with the addition of ammonium acetate buffers, tetrabutylammonium chloride and phosphate buffer.

Chromatography, High Pressure Liquid↗
PubMed1986

Fournier's gangrene complicating aggressive therapy for hematologic malignancy.

The authors describe two cases of Fournier's gangrene complicating aggressive therapy for hematologic malignancies. Fournier's gangrene is a fulminant necrotizing fasciitis of the scrotum and penis, often with an infectious etiology. Only one prior case has been reported in a patient receiving aggressive chemotherapy for a hematologic malignancy. Unique to these three cases was profound granulocytopenia and the culturing of Pseudomonas aeruginosa in both the blood and necrotic perineal-scrotal tissue. Maintaining a high index of suspicion with early recognition and aggressive therapy may decrease the morbidity and mortality of this devastating and life-threatening infection in the compromised host.

Adolescent↗
PubMed1986

Sex-related differences in free plasma catecholamines in individuals of similar performance ability during graded ergometric exercise.

Sex-related differences of catecholamine responses were evaluated in nine healthy women and six age-matched men at rest and during incremental treadmill exercise. Heart rate, oxygen uptake (VO2), glucose and lactate blood levels as well as the free plasma catecholamines, noradrenaline and adrenaline, were determined. No significant differences were observed for these parameters between the two groups at rest. The females had relative VO2max and maximal running velocities similar to the males, which points to a comparable dynamic performance ability. However, at identical work loads, noradrenaline, adrenaline and glucose levels were significantly higher in women than in men. Lactate, heart rate and relative VO2 showed a similar tendency at submaximal exercise levels, indicating higher strain at identical stress levels in women. The reason for the higher sympathetic activity in women at identical work loads may be their relatively smaller skeletal muscle mass in relation to the loads during this test.

Adult↗
PubMed1986

Skeletal muscle enzyme activities in healthy young subjects.

In three groups of healthy young subjects (n = 33; mean ages 6.4, 13.5, 17.1 years), muscle enzyme activities (creatine kinase, hexose phosphate isomerase, aldolase, pyruvate kinase, lactate dehydrogenase, citrate synthase, fumarase) of the vastus lateralis muscle were investigated to show age-dependent variations. A significant age-dependent increase in aldolase (P less than 0.05) and pyruvate kinase (P less than 0.01) activity and a decrease in fumarase activity (P less than 0.01) were computed. In relation to the age-dependent variation, maximum LDH activities could be measured at an age of 12-14 years; significantly decreased activities of the glycolytic enzymes could only be found in the youngest group.

Adolescent↗
PubMed1985

[Energy yield during physical exertion].

Every energy demanding process in the skeletal muscle is associated with the use of adenosinetriphosphate, the essential muscular high-energy phosphate. ATP is rephosphorylated by ADP (= adenosine diphosphate) and this process depends on the type, intensity and duration of the physical exercise. At the beginning of a vigorous physical exercise utilization of intramuscular ATP and phosphocreatine is predominant (= anaerobic-alactacide energy yielding). Then the ATP rephosphorylation based on the conversion of glycogen and glucose to lactate, especially by an exercise duration till 2 min (= anaerobic-alactacide energy yielding). Toward this duration or if the exertion intensity at start has been below 60 to 70% of maximal physical performance, ADP is rephosphorylated during oxidative phosphorylation by the skeletal muscle mitochondria using glycogen, glucose or free fatty acids as energy fuel. Training, age and sex may influence anaerobic and aerobic energy-yielding as well as metabolism and ultrastructure of skeletal muscle.

Adenosine Triphosphate↗
PubMed1985

Influence of maximum aerobic capacity and relative body weight on the lipoprotein profile in athletes.

The relationship between the individual maximum aerobic capacity (MAC) as well as the relative body weight (BW) and the corresponding lipoprotein profile was studied in male national-class athletes (n = 120, 18-36 years old). Using a stepwise regression analysis, it was shown that only the apoliprotein A-I and HDL cholesterol levels correlated primarily with the maximum aerobic capacity, whereas the serum concentrations of total cholesterol, triglycerides, apo B and LDL cholesterol as well as the apo B/apo A-I ratio were significantly dependent on the relative body weight. Only the HDL/tot. cholesterol ratio was significantly related to both variables, MAC and BW (r = 0.570; P less than 0.001).

Adolescent↗
PubMed1985

Hydrogen concentration in expired air analyzed with a new hydrogen sensor, plasma glucose rise, and symptoms of lactose intolerance after oral administration of 100 gram lactose.

A rapid breath hydrogen analyzer to detect lactose malabsorption is described. After ingestion of a lactose solution the patient expires into a mouthpiece attached to a hydrogen sensor at 30-min intervals for 3 1/2 h. The hydrogen of the expired air causes a voltage change that can be transformed into ppm from a calibration curve. A tolerance test with a load of 100 g lactose was performed in 43 consecutive patients with various gastrointestinal disturbances, referred to the laboratory for the commonly used lactose tolerance test based on plasma glucose measurements. Eleven patients developed symptoms of lactose intolerance during the test. Biopsy specimens from the distal duodenum or proximal jejunum showed partial villous atrophy in one, in whom celiac disease with lactose intolerance was diagnosed; the other 10 had normal specimens. In nine of them lactose intolerance was diagnosed and confirmed by observation for months on a lactose-poor diet. The 10th patient (H.P.L.) did not improve on such a diet. He also showed pronounced symptoms of intolerance during a test with monosaccharides (glucose + galactose). His intestinal disease remained undiagnosed. The 11 patients with symptoms of intolerance and 3 patients without symptoms during the lactose load showed a flat plasma glucose curve after drinking the lactose solution--that is, a maximum rise of the glucose concentration of 1.5 mmol/l. One of the symptom-free patients dropped out and could not be observed, another did not improve on a lactose-poor diet, and the third noticed a favorable effect of the diet on stool consistency but not on other abdominal symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗