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Biomedical subjects

U Herrmann

Publications and source records attributed to U Herrmann.

At least 19 recordsLinked to original sources
PubMed2005

A syringe exchange programme in prison as prevention strategy against HIV infection and hepatitis B and C in Berlin, Germany.

In two prisons in Berlin, Germany, provision of sterile injection equipment for injecting drug users (IDUs) started in 1998. To assess the programme's impact, the frequency of injecting drug use and syringe sharing, and the incidence of HIV, HBV, and HCV infection were determined in a follow-up study. Of all IDUs (n=174), 75% continued to inject. After the project start the level of syringe sharing declined from 71% during a 4-month period of previous imprisonment to 11% during the first 4 months of follow-up, and to virtually zero thereafter. Baseline seroprevalences for HIV, HBV, and HCV were 18, 53, and 82%. HIV and HCV seroprevalence at baseline was significantly associated with drug injection in prison prior to the project start. No HIV and HBV seroconversions, but four HCV seroconversions occurred. The provision of syringes for IDUs in appropriate prison settings may contribute to a substantial reduction of syringe sharing. However, the prevention of HCV infection requires additional strategies.

Adult↗
PubMed2003

Biotransformation of glucose to 5-keto-D-gluconic acid by recombinant Gluconobacter oxydans DSM 2343.

For the conversion of glucose to 5-keto-D-gluconate (5-KGA), a precursor of the industrially important L-(+)-tartaric acid, Gluconobacter strains were genetically engineered. In order to increase 5-KGA formation, a plasmid-encoded copy of the gene encoding the gluconate:NADP-5 oxidoreductase (gno) was overexpressed in G. oxydans strain DSM 2434. This enzyme is involved in the nonphosphorylative ketogenic oxidation of glucose and oxidizes gluconate to 5-KGA. As the 5-KGA reductase activity depends on the cofactor NADP+, the sthA gene (encoding Escherichia coli transhydrogenase) was cloned and overexpressed in the GNO-overproducing G. oxydans strain. Growth of the sthA-carrying strains was indistinguishable from the G. oxydans wild-type strain and therefore they were chosen for the coupled overexpression of sthA and gno. G. oxydans strain DSM 2343/pRS201-gno-sthA overproducing both enzymes showed an enhanced accumulation of 5-KGA.

Bacterial Proteins↗
PubMed2003

Urinary iodine concentration during pregnancy in an area of unstable dietary iodine intake in Switzerland.

We prospectively investigated urinary iodine concentration (UIC) in pregnant women and in female, non-pregnant controls in the canton of Berne, Switzerland, in 1992. Mean UIC of pregnant women [205 +/- 151 microg iodine/g creatinine (microg l/g Cr); no. = 153] steadily decreased from the first (236 +/- 180 microg l/g Cr; no. = 31) to the third trimester (183 +/- 111 microg l/g Cr, p < 0.0001; no. = 66) and differed significantly from that of the control group (91 +/- 37 microg l/g Cr, p < 0.0001; no. = 119). UIC increased 2.6-fold from levels indicating mild iodine deficiency in controls to the first trimester, demonstrating that high UIC during early gestation does not necessarily reflect a sufficient iodine supply to the overall population. Pregnancy is accompanied by important alterations in the regulation of thyroid function and iodine metabolism. Increased renal iodine clearance during pregnancy may explain increased UIC during early gestation, whereas increased thyroidal iodine clearance as well as the iodine shift from the maternal circulation to the growing fetal-placental unit, which both tend to lower the circulating serum levels of inorganic iodide, probably are the causes of the continuous decrease of UIC over the course of pregnancy. Mean UIC in our control group, as well as in one parallel and several consecutive investigations in the same region in the 1990s, was found to be below the actually recommended threshold, indicating a new tendency towards mild to moderate iodine deficiency. As salt is the main source of dietary iodine in Switzerland, its iodine concentration was therefore increased nationwide in 1998 for the fourth time, following increases in 1922, 1965 and 1980.

Adult↗
PubMed2000

Ascorbic acid in idiopathic recurrent calcium urolithiasis in humans--does it have an abettor role in oxalate, and calcium oxalate crystallization?

The role of ascorbic acid (ASC) in the pathophysiology of renal calcium stones is not clear. We evaluated ASC in blood and urine of fasting male patients with idiopathic calcium urolithiasis (ICU) and healthy volunteers. Using smaller subgroups, we also evaluated their response to exogenous ASC [either intravenous or oral ASC (5 mg/kg bodyweight)] administered together with an oxalate-free test meal. The influence of ASC on calcium oxalate crystallization, the morphology of crystals at urinary pH 5, 6 and 7, and the effect of increasing duration of urine incubation on urinary oxalate at these pHs, without and with addition of ASC, were studied too. In normo- and hypercalciuric ICU, blood and urinary ASC from fasting patients remained unchanged, but the slope of the regression line of urinary ASC versus urinary oxalate was steeper than in the controls; the plasma ASC half-life did not differ between controls, normo- and hypercalciuric ICU; the ASC-supplemented meal caused an increase in the integrated plasma oxalate in the normocalciuric subgroup versus controls. In normo- and hypercalciuric ICU urinary oxalate, the oxalate/glycolate ratio, and calcium oxalate supersaturation were increased, but urinary glycolate was unchanged. In the controls, oral ASC did not affect calcium oxalate crystallization, while in ICU, ASC inhibited crystal growth. In control urine calcium oxalate dihydrate and calcium oxalate monohydrate develops, while in ICU urine only the former crystal type develops. In vitro oxalate neoformation from ASC did not occur. It was concluded that (1) under normal conditions an abettor role of ASC for renal stones is not recognizable, (2) in ICU, urinary oxalate excess unrelated to degradation of exogenous ASC is exhibited, and that this is most likely unrelated to an initial increase in oxalate biosynthesis, and (3) ASC appears to modulate directly calcium oxalate crystallization in ICU, although the true mode of action is still not known.

Administration, Oral↗
PubMed2000

Maculopathy in patients with diabetes mellitus type 1 and type 2: associations with risk factors.

AIM: To examine possible relation between diabetic maculopathy and various risk factors for diabetic complications in patients with diabetes mellitus type 1 and type 2. METHODS: Cross sectional study of two cohorts of diabetic patients, comprising 1796 patients with type 1 diabetes (mean age 47 years, mean duration of diabetes 24 years) and 1563 patients with type 2 diabetes (mean age 62 years, mean duration of diabetes 16 years). Retinopathy levels (R0-RV) and maculopathy were assessed by fluorescence angiography and fundus photography and binocular biomicroscopy. Diabetic neuropathy was assessed by means of computer assisted electrocardiography and by thermal and vibratory sensory examination. Patients were classified as normoalbuminuric (<20 microg/min) or microalbuminuric (20-200 microg/min) according to their albumin excretion rates measured in urine collected overnight. Using univariate analyses, the effects of selected patient characteristics on the presence of maculopathy were evaluated. Multiple logistic regression analyses were performed to determine independent effects of risk variables on diabetic maculopathy. RESULTS: Background retinopathy (RII) was found to be present in 28% of type 1 diabetic patients and in 38% of type 2 diabetic patients. The prevalence of maculopathy in these patients was remarkably high (42% in type 1 and 53% in type 2 diabetic patients). Patients with maculopathy had significantly impaired visual acuity. Multiple logistic correlation analysis revealed that in both types of diabetes maculopathy exhibited independent associations with duration of diabetes and with neuropathy (p <0. 01); in type 1 diabetic patients there were significant associations with age at diabetes onset, serum triglyceride and total cholesterol levels (p <0.05); in type 2 diabetes with serum creatinine levels and with hypertension (p <0.05). CONCLUSIONS: Irrespective of the type of diabetes, diabetic patients with long standing diabetes have a high risk for the development of diabetic maculopathy. Diabetic maculopathy is closely associated with diabetic nephropathy and neuropathy and with several atherosclerotic risk factors which suggests that these factors might have an important role in the pathogenesis of maculopathy. However, prospective trials are necessary to evaluate the predictive value of such factors. The findings of the present cross sectional study reinforce the arguments of previous studies by others for tight control of hypertension and hyperglycaemia.

Adult↗
PubMed1999

Magnesium, citrate, magnesium citrate and magnesium-alkali citrate as modulators of calcium oxalate crystallization in urine: observations in patients with recurrent idiopathic calcium urolithiasis.

The effects of magnesium (Mg) and citrate on the metastable limit of calcium oxalate (CaOx) solubility (synonym: tolerable oxalate TO) were examined in artificial urine and in postprandial urine of male patients with idiopathic calcium urolithiasis (ICU). In artificial urine increasing pH, Mg and citrate elevate TO, decrease CaOx supersaturation only marginally, but elevate considerably free citrate; the effect of Mg alone was small in comparison with citrate alone, and the effects of both substances appeared additive. In ICU patients, matched for sex, age and CaOx supersaturation to non-stone-forming controls, TO was decreased (mean values 0.33 vs. 0.52 mM/l in controls, P < 0.05). Additional significant (P < 0.05) differences were found between ICU and controls: the former exhibited increased CaOx crystal growth, decreased crystal agglomeration time, a more acidic urinary pH, increased concentrations of free calcium and free Mg, and decreased free oxalate and free citrate. After ingestion of a urine-acidifying test meal, or this meal supplemented with either neutral Mg citrate or Mg-alkali citrate, by three groups of male ICU patients, matched for age and CaOx supersaturation, only the last-named preparation evoked an increase in TO and a decrease in crystal diameter, while the normally occurring pH decline from fasting urine was virtually abolished, and the ratios urinary Mg/citrate and calcium/citrate tended towards low values. In contrast, Mg citrate increased crystal agglomeration time, while changes in the other parameters were only insignificant. The crystals formed in urine were CaOx di- and monohydrate (by electron microscopy), and energy dispersive X-ray analysis showed calcium peaks exclusively. However, chemical analysis of crystals verified the presence not only of oxalate and calcium, but also of Mg, phosphate, citrate, and urate; moreover, these crystal constituents seemed to be influenced by Mg citrate and Mg-alkali citrate in different ways. It was concluded that (1) Mg and citrate are effectors of TO in artificial and natural urine; (2) in ICU, low TO and other disturbed CaOx crystallization parameters appear related to the prevailing low urinary pH and low free citrate; (3) Mg-alkali citrate inhibits CaOx crystallization, probably via actions of the citrate, but not the Mg. Because of the eminent role of Mg in human health and ICU, further studies on crystallization after oral intake of Mg in the form of citrate are warranted.

Calcium Oxalate↗
PubMed1999

Acute effects of calcium sodium citrate supplementation of a test meal on mineral homeostasis, oxalate, and calcium oxalate crystallization in the urine of healthy humans--preliminary results in patients with idiopathic calcium urolithiasis.

Calcium, in the form of regular food supplementation, can improve bone metabolism, but it can also increase the risk for renal calcium stones, and may aggravate pre-existing calcium urolithiasis. To study the first of these two aspects, ten healthy volunteers were given a conventional test meal (breakfast; calcium content 28 mg) with or without two dosages of calcium (as calcium-sodium citrate, CSC 1, 680 mg; CSC 2 1,360 mg), taken after an overnight 12 h fast. To study the latter aspect, patients with idiopathic recurrent calcium urolithiasis (ICU) received a balanced test meal of fixed composition, containing 1,000 mg calcium either as CSC (Meal + CSC3; n = 6) or as calcium gluconate (Mcal; n = 8). In normals, CSC induced a dose-dependent increasing intestinal absorption of calcium, and a decrease in oxalate absorption; in serum, CSC increased calcitonin and suppressed parathyroid hormone, but left unchanged the markers of bone turnover, serum osteocalcin and bone alkaline phosphatase. In urine, CSC decreased bone resorption markers (collagen crosslinks) and phosphaturia increased citrate, created signs of metabolic alkalosis, and inhibited several parameters of CaOx crystallization. In ICU, the CSC3 load failed to promote the crystallization of CaOx and calcium phosphate. It was concluded that CSC supplementation of a meal: (1) is well tolerated by healthy subjects and ICU patients, renders calcium highly available to bone, and prevents post-prandial oxaluria from rising; and, (2) is followed by the inhibition of crystallization of renal stone forming calcium-containing substances. Long-term studies aimed at evaluating the usefulness of CSC in preserving healthy bone, and in the metaphylaxis of renal stones would appear justified.

Adult↗
PubMed1998

Directional tuning of single motor units.

The directional activity of whole muscles has been shown to be broadly and often multimodally tuned, raising the question of how this tuning is subserved at the level of single motor units (SMUs). Previously defined rules of SMU activation would predict that units of the same muscle (or at least of the same neuromuscular compartment) are activated homogeneously with activity peaks in the same "best" direction(s). In the present study, the best directions of SMUs in human biceps (both heads) and deltoid (anterior, medial, and posterior portions) were determined by measuring the firing rate and threshold force of units for recruitment during isometric force ramps in many different directions. For all muscles studied, neighboring motor units could have significantly different best directions, suggesting that each muscle receives multiple directional commands. Furthermore, 17% of the units sampled clearly had a second-best direction, consistent with a convergence of different directional commands onto the same motoneuron. The best directions of the units changed gradually with location in the muscle. Best directions did not cluster into separate groups, thus, not supporting the existence of clearly distinguished neuromuscular compartments. Instead, the results reveal a more gradually distributed activation of the biceps and deltoid motoneuron pools. A model is proposed in which the central control mechanism optimizes the fulfillment of the continuously changing directional force requirements of a movement by gradually recruiting and derecruiting those units ideally suited for the production of the required force vector at any given time.

Adult↗
PubMed1997

Structure and function of a second gene cluster encoding the formate dehydrogenase of Wolinella succinogenes.

Wolinella succinogenes contains a single formate dehydrogenase, but two gene loci (fdhI and fdhII) code for the subunits of the enzyme. The nucleotide sequence of fdhII is almost identical with that of fdhI in the region comprising fdhEABCD. The sequences of fdhI and fdhII differ in the promotor regions upstream of fdhE. Deletion mutants lacking either fdhI or fdhII synthesize functional formate dehydrogenases, as shown by growth with formate as electron donor and either fumarate or polysulfide as acceptor substrates, and by the presence of the FdhA subunit and of enzyme activity. In the wild-type strain, the fdhI genes appear to be expressed preferentially during growth with formate and fumarate. The six-times greater amount of the enzyme present upon growth with formate and polysulfide is due to the expression of both fdhI and fdhII. The transcription start sites were located 196-bp and 129-bp upstream of the fdhE start codons of fdhI and fdhII, respectively. An apparently single transcript (5.6 kbp) was detected in polysulfide-grown W. succinogenes by Northern-blot analysis, suggesting that the five open reading frames form operons.

Amino Acid Sequence↗
PubMed1997

Postprandial hyperinsulinaemia, insulin resistance and inappropriately high phosphaturia are features of younger males with idiopathic calcium urolithiasis: attenuation by ascorbic acid supplementation of a test meal.

In idiopathic recurrent calcium urolithiasis (RCU) the state of insulin and carbohydrate metabolism, and relationships to minerals such as phosphate, are insufficiently understood. Therefore, in two groups of males with RCU (n = 30) and healthy controls (n = 8) the response to an oral carbohydrate- and calcium-rich test meal was studied with respect to glucose, insulin, and C-peptide in peripheral venous blood (taken before and up to 180 min post-load), and phosphate and glucose in fasting and post-load urine. In one RCU group (n = 16) the meal was supplemented with ascorbic acid (ASC; 5 mg/kg body weight). The mean age (RCU 29, RCU + ASC 30, controls 27 years) and mean body mass index [RCU 24.4, RCU + ASC 25.0, controls 24.0 kg/m2] were similar. Insulin resistance (synonymous sensitivity of peripheral organs to insulin) was calculated from insulin serum concentration, as was also integrated insulin, C-peptide, and glucose. Untreated stone patients (RCU) developed hyperinsulinaemia between 60 and 120 min post-load, increased integrated insulin, and insulin resistance (P < or = 0.05 vs controls), whereas the rise of C-peptide and glycaemia (absolute and integrated values) was only of borderline significance. Fasting phosphaturia was low in both RCU subgroups vs controls; however, phosphaturia in untreated RCU rose in response to the meal, contrasting sharply with a decrease in controls. ASC supplementation of the meal (in the RCU + ASC subgroup) normalized insulin, failed to normalize post-load phosphaturia, but reduced post-load glucosuria and urinary pH significantly (mean pH values 5.55 vs 5.93 in untreated RCU, controls 5.50). Postprandial urinary oxalate, calcium, protein, and supersaturation products were not changed. The postprandial changes in phosphaturia and insulin sensitivity were inversely correlated (n = 38, r = -0.44, P = 0.007). It was concluded that in younger RCU males: (1) postprandial hyperinsulinaemia, the failure to reduce phosphaturia and - within limits - glucosuria, appropriately, as well as poor urine acidification are important features of the metabolism; (2) these phenomena are probably caused by insulin resistance of organs, the kidney included; and (3) the addition of a supraphysiological dose of ASC to a meal, the subsequent abolition of hyperinsulinaemia, and the restoration of normal urine acidification suggest that this antioxidant is capable of counteracting some pre-existing basic abnormality of cell metabolism in RCU.

Adult↗
PubMed1997

Urinary phosphate excretion in the pathophysiology of idiopathic recurrent calcium urolithiasis: hormonal interactions and lipid metabolism.

Previous work in younger males with recurrent idiopathic calcium urolithiasis (RCU) demonstrated inappropriately high postprandial phosphaturia, hyperinsulinemia and insulin resistance, but normal glycemia. To investigate further whether these abnormalities occur also in RCU patients with a mean age corresponding to the life period with peak formation of calcium-containing stones, two trials were carried out in 155 males of comparable age and body mass index. All participants underwent a standardized laboratory examination, including collection of urine and blood before and following a test meal rich in carbohydrate and calcium but low in phosphorus. In trial 1, comprising control subjects (n = 12, mean age 42 years) and RCU patients (n = 24, mean age 41 years), phosphate (Pi) excretion and fractional Pi excretion in postprandial urine of controls did not change compared with the values in fasting urine, but were significantly increased in RCU, despite the fact that there was almost equal suppression of serum parathyroid hormone (PTH) and increase in serum calcitonin. Postprandially, RCU patients were hyperinsulinemic but still normoglycemic versus controls. In trial 2, carried out in unclassified (in terms of calciuria) RCU patients (n = 119, mean age 40 years) only, the post-load Pi-uria was similar in magnitude to Pi-uria of RCU patients in trial 1; increased postprandial Pi-uria was a phenomenon also of normocalciuria but was slightly more pronounced in hypercalciuria, while changes in calcium phosphate (brushite) and calcium oxalate supersaturation of urine were unrelated to calciuria. In RCU patients, but not controls, there was a tendency toward higher urinary glucose in post-load as compared with fasting urine. When urinary Pi and fractional Pi excretion in trial 2 were considered as dependent variables in multivariate regression analysis, they appeared unrelated to age, but positively associated with postprandial glycemia as the best predictor, followed by insulinemia, insulin resistance, to a lesser degree fasting serum PTH and the metabolic activity of stone disease, negatively associated with blood total lipids and very low density lipoprotein (VLDL) cholesterol. It was concluded that RCU males (1) show low Pi-uria during fasting but impaired renal Pi conservation in response to a mixed meal, a situation carrying the risk of Pi deficiency over the long term; (2) represent a population developing hyperPi-uria despite suppressed PTH; (3) exhibit insulin resistance but are still able to maintain normoglycemia at the expense of hyperinsulinemia. It is suggested that calcium-containing renal stones are related to impaired Pi and glucose translocation across cell membranes, and that the role of lipids in this setting deserves further investigation.

Adult↗
PubMed1995

An evaluation of laparoscopic adhesiolysis in patients with chronic abdominal pain.

The purpose of this prospective study was to determine whether laparoscopic adhesiolysis ameliorates chronic abdominal pain in patients with abdominal adhesions. Forty-five patients with chronic abdominal pain lasting for more than 6 months but with no abnormal findings other than adhesions found at laparoscopy underwent laparoscopic adhesiolysis. Thirty-six patients (80%) were available for follow-up after a median time interval of 10 months (range: 6-36 months). Seventeen patients (47.2%) were free from abdominal pain and 13 patients (36.1%) reported significant amelioration of their pain. Six (16.6%) patients had no amelioration. Twenty-nine patients (80.6%) judged the outcome of the operation to be good or beneficial and 35 (97.2%) said that they would undergo the operation a second time if that were necessary. Laparoscopy is an effective tool for the evaluation of patients with chronic abdominal pain, and laparoscopic adhesiolysis cures or ameliorates chronic abdominal pain in more than 80% of patients.

Abdominal Pain↗
PubMed1995

[Diagnosis of malignant uterine tumors by transvaginal ultrasound].

Two hundred and three non-pregnant women who underwent diagnostic dilatation and curettage or hysterectomy were included in a prospective study designed to assess the accuracy of transvaginal sonography in conforming or excluding the presence of uterine cancer. All preoperative sonographic findings were compared with the final histological diagnosis. The predictive value of sonographic evidence of malignancy was 71.1% (32/45), the predictive value of benign disease was 95.6% (151/158). Sensitivity was 82.1% (32/39) and specificity 92.1% (151/164). Although sensitivity and specificity increased as compared to an earlier study using transabdominal ultrasound, we recommend dilatation and curettage in women with postmenopausal bleeding.

Adult↗
PubMed1995

Moving effortlessly in three dimensions: does Donders' law apply to arm movement?

Donders' law, as applied to the arm, predicts that to every location of the hand in space there corresponds a unique posture of the arm as defined by shoulder and elbow angles. This prediction was tested experimentally by asking human subjects to make pointing movements to a select number of target locations starting from a wide range of initial hand locations. The posture of the arm was measured at the start and end of every movement by means of video cameras. It was found that, in general, the posture of the arm at a given hand location does depend on the starting location of the movement and that, consequently, Donders' law is violated in this experimental condition. Kinematic and kinetic factors that could account for the variations in arm posture were investigated. It proved impossible to predict the final posture of the arm purely from kinematics, based on the initial posture of the arm. One hypothesis was successful in predicting final arm postures, namely that the final posture minimizes the amount of work that must be done to transport the arm from the starting location.

Arm↗
PubMed1993

[The energetic utilization of L-fructose in rats].

The energetic utilization of L-fructose (LF) and D-fructose (DF) was investigated by means of indirect calorimetry in a difference trial on 9 male Wistar rats in the live weight range of 250 to 300 g. The daily rations in the two comparable periods with added fructose consisted of 10 g basal diet plus 2.7 g LF or 2.5 g DF. The digestibility and metabolizability of energy of the LF-ration were decreased by about 4 and 6%, resp., in comparison to the DF-ration. The efficiency of total utilization of energy (energy deposition/gross energy) amounted to (7 +/- 3)% (mean +/- SD) for the LF-ration and (10 +/- 3)% for the DF-ration. The lower digestibility of energy of the LF-ration was mainly due to a depression of apparent digestibility of crude protein, crude fat and crude fibre--obviously caused by increased microbial fermentation. With correction of the depression of digestibility the following values of energetic utilization resulted from the difference evaluation for LF and DF, resp.: digestibility (90 +/- 8)% and (100 +/- 6)%, metabolizability (85 +/- 8)% and (102 +/- 5)%, utilization of gross energy for energy deposition (69 +/- 11)% and (86 +/- 11)% and utilization of metabolizable energy (81 +/- 7)% and (84 +/- 11)%, resp.

Animals↗
PubMed1993

[The passage, absorption and secretion of nitrogen during the postprandial period using 15N-labeled wheat and marker in growing rats].

After a 9 day preparation period 42 Wistar rats (live weight 100 g) were fed a diet of 15N labelled wheat supplemented with the marker TiO2 (impulse labelling). At 7 time intervals (0.5 to 6 h after feeding) 6 animals were killed and thereafter total N, 15N and TiO2 levels were estimated in the digesta of different intestinal sections. The following results were obtained: The transit rate of the marker amounted to 10.3 +/- 0.62% per hour of the intake. The endogenous part of N increased during passage from stomach (3.5%) to duodenum (38.6%), jejunum (59.1%), ileum (64.8%), large intestine (78.3%) and faeces (87.7%). The apparent N digestibility in the stomach increased with time reaching 26% 6 h after feeding. In the whole small intestine it was 66.3%, in the ileum 78.9% and in the large intestine 90.4%. The true digestibility (6 h after feeding) showed the same course, but was always some units higher (stomach 33.3%, whole small intestine 82.5%, ileum 92.2% and large intestine 93.5%). Apparent and true digestibility values in the ileum correspond best to the data of precaecal digestibility; those of the large intestine correspond to the postileal digestibility. The N disappearance rate in the stomach is the sum of absorption rate (16%/h) and transit rate into the small intestine (12.4 +/- 1.6 mg N/h). Most absorption occurred during passage through the small intestine (2/3 of total absorption). The absorption in the small intestine was about 80% of the N amount flowing from the stomach into the intestine. The amount lay between 18.2 and 26.1 mg N/h and half of this was of endogenous origin. The reabsorption rate of endogenous N for the whole intestinal tract was estimated to be 91.4%. The N secretion into the whole intestine increased during the 6 h after feeding up to 85.5 mg (64% of N intake), for which 77 +/- 5.5% was secreted into the small intestine. Secretion into the stomach was relatively small and up to 4 hours after feeding, amounted only to 3.0 ... 6.7 mg N.

Animal Feed↗
PubMed1993

Investigations on the influence of Clenbuterol and recombinant porcine somatotropin on nitrogen and energy metabolism in growing pigs.

The effect of Clenbuterol and recombinant porcine Somatotropin (rpST) on the N and energy metabolism was tested by means of the respiration trial technique and compared with a control. In one experiment Clenbuterol was given per os on the nutrition level of three times energy maintenance requirement and in two experiments on the nutrition level 3.2 and 2.4 times energy maintenance requirement, rpST was injected s.c. The live weight gain of the treated animals was 9% (Clenbuterol), 18 and 24% (rpST) higher than that of the controls, protein energy deposition was 21% (Clenbuterol), 45 and 46% (rpST) higher and fat energy deposition was 14% (Clenbuterol), 33 and 37% (rpST) lower than that of the controls.

Aging↗