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Biomedical subjects

M Senft

Publications and source records attributed to M Senft.

At least 37 records · Page 2Linked to original sources
PubMed1992

Long-term wheat germ intake beneficially affects plasma lipids and lipoproteins in hypercholesterolemic human subjects.

In previous short-term studies in rats and humans, the ingestion of raw wheat germ lowered plasma triglycerides and cholesterol. Thus, the present study was designed to investigate the possible long-term effects of wheat germ intake. Diet supplementation with raw wheat germ or partially defatted wheat germ was tested in two separate groups of 10 and 9 free-living human subjects, respectively. They all exhibited hypercholesterolemia (6.14-9.67 mmol/L cholesterol) and 11 had hypertriglyceridemia. None was diabetic. Fasting blood samples were taken at the beginning of the study, after 4 wk of 20 g/d wheat germ intake, after 14 additional weeks of 30 g/d wheat germ intake and after 12 wk without any supplementation. Dietary records were kept for seven and three consecutive days, before and during the wheat germ intake periods, respectively. Raw wheat germ intake significantly decreased plasma cholesterol (-8.7%) and tended to reduce VLDL cholesterol (-19.6%) after 4 wk. After 14 additional weeks, plasma cholesterol (-7.2%) and LDL cholesterol (-15.4%) remained lower and plasma triglycerides (-11.3%) tended to be lower. The apo B:apo A1 ratio significantly decreased after both periods. Partially defatted wheat germ transiently decreased plasma triglycerides and cholesterol after a 4-wk intake. The present data indicate that wheat germ reduces cholesterolemia in the long term and could play a beneficial role in the dietary management of type IIa and IIb hyperlipidemia.

Adult↗
PubMed1991

Plasma lipid lowering effects of wheat germ in hypercholesterolemic subjects.

The present study was performed to investigate the possible effects of wheat germ supplementation on lipid metabolism in humans. Ten free-living adult subjects participated in the study. None was obese or diabetic. They all presented an hypercholesterolemia (from 6.58 to 9.50 mM), associated in 6 over 10 cases to an hypertriglyceridemia (from 1.70 to 5.00 mM). The subjects were studied in three consecutive periods, during which they first were on their usual diet (first week), they then ingested a daily supplement of 30 g wheat germ (4 weeks) and then they returned to their usual basal diet (4 weeks follow-up). Dietary records were obtained for 7 and 3 consecutive days before and during wheat germ supplementation, respectively. Fasting blood samples were taken at the end of each period. After 4 weeks of wheat germ intake, glycemia did not change while total plasma cholesterol significantly decreased (paired Student's t test, p less than or equal to 0.05) from 7.80 to 7.15 mM. LDL and HDL cholesterol values did not show marked changes, but VLDL cholesterol significantly dropped by 40.6%. Thus, the plasma/HDL total cholesterol ratio was significantly lower. Apoprotein B and A1 decreased. In the hypertriglyceridemic subjects, this was accompanied by a significant reduction of plasma triglycerides (1.64 vs. 2.68 mM) and a marked drop of VLDL triglycerides (-51%). Taken as a whole, the present results obtained in humans are very close to those previously obtained in the rat and point out that wheat germ may play a beneficial role in the dietary management of hyperlipidemia.

Adult↗
PubMed1991

Gastric lipase: evidence of an adaptive response to dietary fat in the rabbit.

In the rabbit, the stomach is the only source of preduodenal lipase, and in humans, it is quantitatively the most important. Thus, the adaptive response of gastric and pancreatic lipases to dietary fat was studied in the adult rabbit. Effect of duration was studied by feeding rabbits 12% dietary fat for 1, 2, or 4 weeks or 2.7% for 2 weeks (control). To study the effects of the amount of fat, rabbits were fed the control diet (2.7% fat) or 6% and 12% dietary fat for 2 weeks. The influence of sunflower oil and butter was compared by feeding rabbits 12% dietary fat for 2 weeks. Approximately doubling (6% vs. 2.7%) the usual amount of dietary fat was sufficient to induce a maximum increase in gastric lipase activity in the fundus [+ 66.3% (units per gram tissue) or + 85.2% (units per milligram protein)] and the total stomach mucosa [+ 84.5% (units per mucosa)], whereas pancreatic lipase activity only significantly increased when rabbits were fed 12% dietary fat. A full adaptive response was observed for both gastric and pancreatic lipases after 2 weeks of diet. Triglyceride composition did not noticeably change the adaptive response of both lipolytic enzymes. The present results agree closely with those concerning lingual lipase in the rat and evidence that gastric lipase shows an adaptive response to moderate fat intake. The implications of these findings concerning humans are discussed.

Adaptation, Physiological↗
PubMed1990

Effect of wheat bran and wheat germ on the intestinal uptake of oleic acid, monoolein, and cholesterol in the rat.

The effects of fiber-rich wheat bran and wheat germ on the intestinal absorption of dietary cholesterol, free fatty acids, and monoglycerides were studied. Rats were given a test meal containing [(14)C]oleic acid, [(14)C]monoolein, and [(3)H]cholesterol. After a 1-hour digestion period, wheat bran or wheat germ (10% of meal solids) did not significantly modify the gastric emptying of lipids. No effect of wheat bran was evidenced on the amounts of lipids and cholesterol in the intestinal content or the mucosal segments, whereas wheat germ significantly increased the cholesterol in the small intestine content, decreasing its intestinal absorption. Both fractions only slightly influenced the levels of absorbed lipids and cholesterol in the plasma and liver. In vitro binding measurements showed that the wheat fractions bind only 7% to 15% of both lipids and cholesterol. Results indicate that wheat bran has no direct effect on the mucosal uptake process, whereas wheat germ might decrease the uptake of dietary cholesterol by an as yet unknown mechanism.

Journal Article↗
PubMed1990

Adaptation of lingual lipase to dietary fat in rats.

To study the adaptive response of lingual lipase and pancreatic lipase to dietary fat, three sets of experiments were performed in adult male rats. In the first experiment, rats were fed for 3 wk a low fat diet (4.5% fat) or a 10, 20 or 30% fat diet. In the second, rats were fed a 4.5% fat diet for 4 wk or a 20% fat diet for 1, 2 or 4 wk. In the third, rats were fed for 3 wk a 10% fat diet with various sources of fat (lard, sunflower oil, olive oil, peanut oil, butter, soybean oil, corn oil or salmon oil). The results demonstrated that 10% dietary fat was sufficient to promote a maximum significant increase in lingual lipase activity (expressed in units/g tissue and in units/mg protein), whereas pancreatic lipase responded steadily to 20 and 30% fat diets. After 1 wk of feeding 20% dietary fat, both enzyme specific activities had reached their maximum values. The fatty acid composition of dietary triglyceride molecules (chain length, number and location of double bonds) had no specific effect on the adaptation of lingual lipase. The physiological implications of these findings are discussed in regard to the role of intragastric lipolysis in fat digestion.

Animals↗
PubMed1989

Wheat bran and wheat germ: effect on digestion and intestinal absorption of dietary lipids in the rat.

We investigated the effects of fiber-rich wheat bran and wheat germ on dietary fat and cholesterol assimilation. Rats were given a test meal containing [14C]triolein and [3H]cholesterol. After various digestion periods, addition of the wheat fractions (10% of meal solids) did not modify the lipid gastric emptying rate. Gastric and intestinal triglyceride lipolysis was significantly reduced when wheat fractions were present. The mucosal uptakes of [14C]lipids and [3H]cholesterol were significantly modified by the wheat fractions after 1 and 2.5 h. No shift in the site of intestinal absorption and no change in the distribution of labeled lipid in the intestinal mucosa was observed. Plasma [14C]lipids and [3H]cholesterol were significantly decreased by both wheat fractions whereas these increased cecal accumulation of dietary lipids and cholesterol. Thus wheat bran and wheat germ alter fat and cholesterol processing in rats. A mechanism of action accounting for the data observed in proposed.

Animals↗
PubMed1989

Lack of effect of purified cellulose and hemicellulose on the digestion and the intestinal absorption of dietary lipids in the rat.

Fasted adult rats were intragastrically intubated an emulsified test meal containing both 14C-triolein and 3H-cholesterol, in the presence or absence of either purified hemicellulose (xylan) or cellulose (both 10% of meal solids). After a 1-hour digestion period, purified fibers did not significantly modify the rate of gastric emptying of lipids or the extent of triglyceride lipolysis in the stomach and the small intestine. The presence of cellulose or hemicellulose induced no change in the amounts of lipids and cholesterol found in the intestinal content, the mucosa, and the plasma, nor in the site of lipid mucosal uptake. As a whole, the present results show that cellulose or hemicellulose, which are the main fractions of dietary fiber in cereals, did not exert a determinant influence on the biochemical events involved in the digestion of dietary fats.

Animals↗
PubMed1989

[Comparison between oral nutrition and enteral nutrition using a percutaneous endoscopically guided gastrostomy (PEG) in patients undergoing radiotherapy for head and neck tumors].

The nutritional state of 99 patients with tumors in the head and neck area was determined prior to, during and after radiotherapy by anthropometric, laboratory-chemical and immunological parameters. In 73 orally nourished patients, the nutritional parameters deteriorated very quickly during radiotherapy and recovered slowly and incompletely after radiotherapy. In 26 patients treated prospectively by percutaneous endoscopically guided gastrostomy (PEG), however, an improved nutritional state was achieved already during the irradiation in spite of a less favorable starting point. The subjective feeling of patients was questioned by means of the "quality of life" index according to Padilla et al. (1983). The preliminary results show an identical deterioration of the subjective feeling in both groups, but - as opposed to the other patients - force and working capacity did not decrease during radiotherapy in the enterally nourished patients. This corresponds to the objective nutritional parameters. However, an improvement of the subjective feeling after the end of radiotherapy was observed only in the orally nourished patients. Possible reasons are discussed. We have the opinion that an early and constant enteral nutrition by PEG can stabilize the nutritional state of patients with tumors in the head and neck area. Therefore we recommend to establish a prophylactic, pretherapeutic PEG if an aggressive multimodal therapy is planned, especially in case of apparent primary malnutrition.

Body Mass Index↗
PubMed1988

Atopy and anaphylactic reactions to suxamethonium.

Muscle relaxants are widely used for general anesthesia and may be responsible for IgE-dependent anaphylactic reactions (AR). A controversial issue in the field of drug allergy is whether ARs are more frequent or severe in atopic subjects. Thus, we performed a case-control study comparing the distribution of various clinical and biologic signs of atopy. The case group included 32 patients with a history of AR to suxamethonium, the most commonly used muscle relaxant. The control group included 128 subjects, matched to the case group according to age, gender, and socioeconomic status. The case group consisted mainly of young and middle-aged women. Distribution of symptoms suggestive of atopy and of skin tests and specific IgE to common aeroallergens was similar in both groups. In contrast, total serum IgE level was much higher in the case group, suggesting the presence of specific IgE against suxamethonium or other drugs. Thus, despite previous studies in the literature, atopy is not a risk factor for the occurrence of anaphylactic reactions to muscle relaxants. As AR to suxamethonium is a pure model of an IgE-dependent drug allergy, our data do not support a relationship between atopy and allergic drug reactions.

Allergens↗
PubMed1988

[The role of alpha-amylase in baker's asthma].

We report a case of asthma in a baker provoked by an additive which is generally used in bread making, namely alpha-amylase, an extract of Aspergillus oryzae. Skin tests to alpha-amylase were positive in a concentration of 0.1 micrograms/ml. Specific IgE was detected to this enzyme. A provocation test to alpha-amylase was positive with a fall of the FEV1 of 42%. Provocation tests to flour gave a negative immediate and delayed reaction. Progress was made towards the disappearance of symptoms after several months of avoiding the allergen. This observation has enabled us to show the specificity of the allergy to alpha-amylase, a glycolytic enzyme, coming in the group of occupational diseases n. 63 (asthma due to lyophilised enzymes) whereas baker's asthma is at n. 66.

Adult↗
PubMed1987

Role of the quaternary ammonium ion determinants in allergy to muscle relaxants.

Anaphylaxis to muscle relaxants appears to be a very useful model to study the IgE-dependent mechanisms of mediator release in humans. The serum IgE binding sites of the drugs appeared to be the ammonium ion determinants. In patients allergic to suxamethonium, one of the most frequently used muscle relaxants for general anesthesia, significant histamine release could be obtained in each case with simple diammonium salts. The length of the chain linking the ammonium groups appears to play an important role. In fact, when the length was less than or equal to 4 A, no significant histamine release could be obtained, whereas the optimal length for histamine release appeared to be greater than or equal to 6 A. Furthermore, muscle relaxants with a rigid backbone between the ammonium determinants (such as pancuronium) are less active than flexible molecules (such as suxamethonium) in initiating mediator release. This study suggests that small divalent molecules can induce anaphylactic shock in sensitized patients and that the length and the flexibility of the chain bearing the haptenic determinants appear to be important factors in the elicitation of mediator release.

Drug Hypersensitivity↗
PubMed1987

Allergy to suxamethonium: persisting abnormalities in skin tests, specific IgE antibodies and leucocyte histamine release.

Twenty-one patients, who had previously experienced an anaphylactic reaction to suxamethonium during general anaesthesia, were selected for this study. Initially, skin tests with muscle relaxants were carried out in the twenty-one patients, detection of specific anti-choline IgE in nineteen, and leucocyte histamine release in seventeen. These three tests were then repeated between 1 year and 4 years after the initial evaluation. In the majority of patients, sensitization to the muscle relaxants persisted for more than 1 year after the anaphylactic reaction. Only three patients out of twenty-one (4%) had negative skin tests when retested 1-4 years later. A reduction in leucocyte histamine release was noticed in one of the seventeen retested patients (6%). Modifications of anti-choline IgE were observed in five of nineteen patients (26%). The persistence of sensitization to suxamethonium may result from repeated stimulation by occasional contacts with quaternary ammonium compounds. This study demonstrates the reliability of skin tests, leucocyte histamine release and detection of anti-choline IgE to diagnose allergic reactions to suxamethonium, even when they are performed a long time after the initial anaphylactic reaction.

Alcuronium↗
PubMed1986

[Anaphylactic complications due to suxamethonium].

A study was carried out on 36 patients who had presented with an anaphylactic reaction when they had been received anaesthetic induction agents including suxamethonium. After having been examined, they were assessed with various immunoallergic tests (skin tests, LHL, a search for specific anticholine IgE antibodies). They were compared with a group of 120 control patients with the same age, sex and professional characteristics. This study confirmed the part played by specific IgE antibodies in accidents involving suxamethonium. The specificity of the tests that could be used for the diagnosis was excellent. However, as far as sensitivity of the tests went, skin tests and LHL were more sensitive than the search for specific IgE antibodies. There was no statistical relationship between the limit for skin reactions and the degree of histamine release of the level of anticholine IgE antibody.

Adult↗
PubMed1985

[Immediate hypersensitivity to quinine].

Systemic anaphylactic reaction with shock was observed after ingestion of an antipyretic combination product containing quinine. That quinine was responsible for the reaction was proven by immediate skin tests and by oral challenge tests. The demonstration of specific IgE's by a radioallergosorbent test (RAST) provided evidence for an immediate hypersensitivity mechanism.

Adult↗
PubMed1985

Leukocyte histamine release to suxamethonium in patients with adverse reactions to muscle relaxants.

In an earlier study we confirmed the usefulness of intradermal skin tests and histamine release in diagnosis of patients reactive to muscle relaxants, and we suggested an IgE-mediated reaction rather than an idiosyncratic mechanism. In a later study, we studied the relationship between (Formula: see text) that is one of the muscle relaxants producing the most frequent adverse reactions under anesthesia. Histamine release was measured in five patients with increasing concentrations of suxamethonium in the presence or absence of human serum albumin in Tris buffer. Suxamethonium by itself without any carrier in the buffer could, in vitro, act as a true allergen on target leukocytes in the sensitized patients' group. Acetylcholine (20 and 200 micrograms/ml) did not induce significant histamine release in five patients with positive histamine release in the presence of suxamethonium. Preincubation of leukocytes from 11 patients for 30 min with 20 and 200 micrograms of acetylcholine in Tris albumin CA++ Mg++ buffer decreased the histamine release induced by suxamethonium (10 micrograms/ml); mean maximal histamine release of 46% +/- 4.2 was reduced to 31.4 +/- 5.8 and 7% +/- 4 (p less than 0.001), respectively. However, in eight control subjects similar concentrations of acetylcholine did not change the maximal histamine release induced by anti-IgE (0.2 micrograms/ml). In the same way acetylcholine did not modify histamine release induced by Dermatophagoides pteronyssinus extract (1/10,000 w/v) in six patients allergic to this allergen. This study suggests that suxamethonium acts as a true allergen and that acetylcholine or one of its metabolites may act as a hapten inhibitor in the model of histamine release induced by suxamethonium.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1985

Anaphylactic reactions to suxamethonium prevention of mediator release by choline.

IgE antibodies cross-reacting with choline and suxamethonium were found in the sera of 15 of 22 patients with life-threatening sensitivity to suxamethonium, one of the most commonly used muscle relaxants. Furthermore, choline that is one of the metabolites of acetylcholine and a monovalent part of the suxamethonium molecule could act as a hapten inhibitor in vitro and in vivo, blocking specifically the basophil histamine release induced by suxamethonium and the positive skin tests to the drug in allergic patients. These results confirm the IgE dependency of allergic reactions to suxamethonium and suggest a possible way of preventing such reactions with choline.

Anaphylaxis↗