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Biomedical subjects

H Dittrich

Publications and source records attributed to H Dittrich.

At least 19 recordsLinked to original sources
PubMed2003

Randomised trial on the influence of continuous magnesium infusion on arrhythmias following cardiopulmonary bypass surgery for congenital heart disease.

OBJECTIVES: To check the hypothesis that continuous magnesium infusion protects the heart from arrhythmias following cardiopulmonary bypass surgery for congenital heart disease. DESIGN: A prospective randomised placebo-controlled study, with patients stratified in three weight groups. PATIENTS AND PARTICIPANTS: The study group ( n=65) postoperatively received a magnesium infusion (1 mmol/kg), the control group ( n=66) received placebo. In both groups serum and ionised magnesium values were followed, and all postoperative arrhythmias were documented for 24 h. MEASUREMENTS AND RESULTS: Serum and ionised magnesium in the blood was elevated after the end of bypass (0.54+/-0.15 mmol l(-1) pre-operatively, 0.88+/-0.24 mmol l(-1) postoperatively), where a cardioplegia solution containing magnesium was used. Magnesium values remained at this elevated level in the magnesium therapy group, and decreased to normal pre-operative values within 24 h in controls ( P<0.001). The incidence of postoperative arrhythmias was lower in the study group: 8/65 in the study group and 17/66 in the control group, respectively (chi-squared test, P=0.05). Lower patient weight (32.7 kg versus 22.6 kg), longer cardiopulmonary bypass time (128.7 min versus 87.9 min) and deeper body temperature during extracorporeal circulation (29.2 degrees C versus 32.6 degrees C) were identified as risk factors for postoperative arrhythmias ( P<0.05). CONCLUSIONS: Continuous magnesium infusion effectively reduces the rate of arrhythmias following cardiopulmonary bypass surgery for congenital heart disease and should, therefore, be routinely used.

Arrhythmias, Cardiac↗
PubMed2003

Neurodevelopment at 1 year of age in infants with congenital heart disease.

OBJECTIVE: To assess psychomotor development and neurological sequelae in infants after surgery for congenital heart defects. DESIGN AND SETTING: Single institution prospective cohort study. PATIENTS: 90 of 112 consecutive surviving infants of less than 1 year of age, without brain anomalies, conditions, or syndromes associated with delayed mental development, who underwent cardiac surgery during an 18 month period; 20 control infants with minor or no congenital heart defects. MAIN OUTCOME MEASURES: Griffiths developmental scales and standardised neurological examination at 1 year. RESULTS: Mean (SD) developmental quotient (DQ) in index infants was 99 (10.6), compared with 106.7 (6.6) in controls (p < 0.001). DQ was lower in infants after palliative surgery (n = 16; 88 (12.2)) than after corrective surgery (n = 74; 101.4 (8.6)) (p < 0.001). Of the 90 index infants, 24 (27%) had a DQ below 93.5 (more than 2 SD below the mean of controls). Developmental delay (DQ < 93.5) was more common after palliative surgery (10/16, 63%) than after corrective surgery (14/74, 19%) (p < 0.001). Of the 90 index infants, 29 (32%) had neurological abnormalities, compared with only one of the 20 controls (5%) (p = 0.013). Neurological abnormalities were more frequent after palliative surgery (11/16, 69%) than after corrective surgery (18/74, 24%) (p < 0.001). CONCLUSIONS: There is a considerable rate of neurodevelopmental impairment at 1 year of age in infants after cardiac surgery. Psychomotor impairment and neurological sequelae are apparently more severe in infants in whom only palliative surgery is possible.

Cohort Studies↗
PubMed2000

Detection of angiographically significant coronary artery disease with accelerated intermittent imaging after intravenous administration of ultrasound contrast material.

BACKGROUND: Accelerated intermittent harmonic imaging (AII) is used to detect myocardial perfusion abnormalities after intravenous injection of ultrasound contrast medium. A low mechanical index and frame rates of 10 to 20 Hz are used to allow simultaneous wall motion analysis. The purpose of this study was to determine whether the myocardial contrast enhancement achieved with AII can be used to detect angiographically significant coronary artery disease during stress echocardiography. METHODS: We gave intravenous perfluorocarbon containing microbubbles to 45 patients (total of 270 regions) during dobutamine (n = 27) or exercise (n = 18) stress testing with AII. Quantitative angiography was performed on all patients after the stress echocardiograms were interpreted. RESULTS: Quantitative angiography showed >50% diameter stenosis of at least 1 vessel in 32 patients (total of 118 regions). There were visually evident contrast defects in 100 (85%) of these regions, and wall motion was abnormal in 64 (54%). Overall, there was agreement between regional perfusion and quantitative angiographic findings in 217 of the 270 regions (kappa = 0.61; 80% agreement). Agreement with findings at quantitative angiography was good for both dobutamine stress (kappa = 0.66; 83% agreement) and exercise (kappa = 0.53; 77% agreement). The greatest incremental benefit of AII versus wall motion was gained during dobutamine stress. The contrast studies depicted 90% of the regions supplied by a vessel with >50% stenosis, whereas wall motion depicted only 32% (P =.001). CONCLUSIONS: The results of this study indicated that accelerated intermittent perfusion imaging during stress echocardiography can improve the sensitivity of the study in detecting angiographically significant coronary artery disease, especially during dobutamine stress.

Adult↗
PubMed1999

Evaluation of myocardial, hepatic, and renal perfusion in a variety of clinical conditions using an intravenous ultrasound contrast agent (Optison) and second harmonic imaging.

OBJECTIVE: To assess the potential of intravenous Optison, a second generation ultrasound contrast agent, and various ultrasound imaging modes to determine myocardial, kidney, and liver perfusion in normal subjects and patients with left ventricular dysfunction or chronic pulmonary disease together with renal or hepatic dysfunction. METHODS: Five normal subjects and 20 patients underwent grey scale echocardiographic imaging of myocardium, kidney, and liver during 505 intravenous injections of Optison. Images were assessed qualitatively by two independent observers and quantitatively using video densitometry to determine the peak contrast enhancement effect. RESULTS: Qualitative analysis showed that intermittent harmonic imaging was superior to either conventional fundamental or continuous harmonic imaging for all organs. Quantitative analysis showed that the peak change in echocardiographic intensity v baseline during continuous harmonic imaging was 11 units for myocardium (p < 0.03), 7 units for kidney (NS), and 14 units for liver (p < 0.05). During intermittent harmonic imaging the peak change was significantly greater, being 33 units for myocardium (p < 0.0001), 24 units for kidney (p < 0.0002), and 16 units for liver (p < 0.001). CONCLUSIONS: Organ tissue perfusion can be demonstrated following intravenous injection of Optison, particularly when used in combination with intermittent harmonic imaging techniques. This contrast agent is effective in a variety of clinical conditions.

Adult↗
PubMed1997

Detection of coronary artery disease with myocardial contrast echocardiography: comparison with 99mTc-sestamibi single-photon emission computed tomography.

BACKGROUND: The purpose of this study was to determine whether myocardial contrast echocardiography (MCE) can be used to detect coronary artery disease (CAD) during rest and pharmacological stress in humans through the use of venous injections of contrast. METHODS AND RESULTS: Thirty patients with known or suspected CAD underwent MCE and 99mTc-sestamibi single-photon emission computed tomography (SPECT) at baseline and after dipyridamole (0.56 mg x kg(-1)) infusion. Ten myocardial segments (5 each in the apical two- and four-chamber views) from the two sets of images using both methods were scored for myocardial perfusion as follows: 1=normal, 0.5=mildly reduced, and 0=severely reduced. The information from baseline and postdipyridamole images was then used to determine whether an abnormal segment was irreversible (similar abnormal perfusion at baseline and after dipyridamole) or reversible (perfusion better at baseline compared with after dipyridamole). Concordance between segmental scores was 92% (kappa=.99) for both methods. Concordance between normal perfusion and reversible or irreversible segmental defects was 90% (kappa=.80). Agreem between the two methods for each of the three vascular territories in each patient was 90% (kappa=.77), while agreement for the presence or absence of CAD in each patient was 86% (kappa=.86). In the 4 patients with disagreement, the perfusion scores were 0.5 for SPECT and 1.0 for MCE. CONCLUSIONS: This study shows that MCE, with venous injection of contrast, can define the presence of CAD during rest and pharmacological stress. The location of perfusion abnormalities and their physiologic relevance (reversible or irreversible) by MCE is similar to that provided by SPECT. MCE, therefore, holds promise for the noninvasive assessment of myocardial perfusion in humans.

Adult↗
PubMed1996

Provocation of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy. Comparison of orthostasis testing and nitrate application.

Several provocation maneuvers are described in hypertrophic cardiomyopathy to Doppler echocardiographically distinguish the obstructive from the non obstructive type. No data are available about the value of orthostasis testing in comparison with nitrate application in this disease. In this study, 16 consecutive patients with hypertrophic cardiomyopathy were examined. 11 patients with hypertrophic cardiomyopathy were classified as obstructive, 5 patients with hypertrophic cardiomyopathy as non obstructive. Normal left ventricular outflow tract velocities as detected by the Doppler method were defined as < 2.0 m/s. Doppler echocardiographic measurements were performed after 10 minutes in supine position, within 10 minutes after head-up tilt and again, within 10 minutes in supine position. If systolic blood pressure during this examination exceeded 100 mm Hg 2.5 mg isosorbiddinitrate were sprayed sublingually. Measurements were done after 20 minutes in supine position and within 10 minutes after head-up tilt. Only in 7 of the 11 patients with hypertrophic obstructive cardiomyopathy maximal left ventricular outflow tract velocity in supine position measured > 2.0 m/s (2.2 +/- 0.8). During head-up tilt, all patients showed increased values (3.8 +/- 1.2 m/s). No differences in maximal left ventricular outflow tract velocity between head-up tilt and nitrate application in supine position (3.5 +/- 1.4 m/s) were present. All patients with hypertrophic non obstructive cardiomyopathy showed maximal left ventricular outflow tract velocities < 2.0 m/s in every step of the examination. Consequently, orthostasis testing was able to identify all patients with hypertrophic obstructive cardiomyopathy and demonstrated a diagnostic value similar to nitrate application.

Adult↗
PubMed1995

Characterization and mechanism of the berberine bridge enzyme, a covalently flavinylated oxidase of benzophenanthridine alkaloid biosynthesis in plants.

The berberine bridge enzyme ((S)-reticuline:oxygen oxidoreductase (methylene-bridge-forming), EC 1.5.3.9) catalyzes the oxidative cyclization of the N-methyl moiety of (S)-reticuline into the berberine bridge carbon, C-8, of (S)-scoulerine. This is a reaction that has neither an equivalent in organic chemistry nor a parallel in nature. The uniqueness of this catalytic reaction prompted an in depth study that began with the isolation of the cDNA encoding the berberine bridge enzyme followed by the overexpression of this cDNA in insect cell culture. The heterologously expressed enzyme has herein been shown to contain covalently attached FAD in a molar ratio of cofactor to protein of 1:1.03. Site-directed mutagenesis and laser desorption time-of-flight mass spectrometry suggest that the site of covalent attachment is at His-104. The holoenzyme exhibited absorbance maxima at 380 and 442 nm and a fluorescence emission maximum at 628 nm (310 nm excitation). Enzymic transformation of a series of (S)-reticuline derivatives modified with respect to the stereochemistry at C-1 or in the aromatic ring substitution suggests that ring closure proceeds in two steps: formation of the methylene iminium ion and subsequent ring closure via an ionic mechanism.

Alkaloids↗
PubMed1995

[Morphology and biological integration of autodermoplasties in large incisional hernias. Results of an experimental study].

UNLABELLED: Their aim of the experimental study was to investigate the morphology and wound healing of "Kutisplastik"-technique, originally introduced by Loewe (1913) and Rehn (1914), from different conditions. We want to clarify the mechanism and development of revascularisation. RESULTS: The well known phases of wound healing also appear in the situation of a cutisplasty. In the exsudative reaction the cutis is covered from fibrin fibers. This leads to the development of granulation tissue. The cellular reaction demonstrates first the in-growth of capillary bundles and vessels in the collagen network of corium. The revascularisation is finished up to 14 days after the operation. The other part is the immigration of granulocytes and macrophages in the graft. The release of enzymes leads to the lysis of epidermal structures, cutaneous appendages and at least to collagen fibers of corium. There is also a proliferation from fibroblasts. The genesis from new collagen fibers is then observed so a scar tissue reveals. The "Kutisplastik"-technique contains that the epidermal side of the graft is turned upside-down towards the peritoneum and is sutured under as high tension as possible to the healthy fascia around. This morphology of healing is seen only under high-tension suturing. In the experimental mode of non-tension suturing there is a lack of success in cutisplasty for abdominal wall defects.

Animals↗
PubMed1994

[Morphology and healing of skin repair in abdominal wall defects. An animal experiment study].

UNLABELLED: The aim of the experimental study was to investigate morphology and wound healing following the skin plasty ("Kutisplastik") technique originally introduced by Loewe [11] and Rehn [17] under different conditions. We wanted to clarify the mechanism and development of revascularisation. RESULTS: The familiar phases of wound healing take the usual course after a skin plasty. In the exsudative reaction the cutis is covered with fibrin fibres. This leads to the development of granulation tissue. The cellular reaction takes place in two parts: first comes the ingrowth of capillary bundles and vessels in the collagen network of corium; revascularization is complete within 14 days after the operation. This is followed by the immigration of granulocytes and macrophages into the graft. The release of enzymes leads to the lysis of epidermal structures, cutaneous appendages and ultimately to collagen fibres of corium. There is also proliferation from fibroblasts. Genesis from new collagen fibres is then observed as scar tissue. The skin plasty technique involves turning the epidermal side of the graft to the peritoneum and suturing it under the highest tension possible to the surrounding healthy fascia. This course of healing is seen only with such high-tension suturing. Experimental nontension suturing has led to failure of skin plasty for abdominal wall defects.

Abdominal Muscles↗
PubMed1994

Heterologous expression of the plant proteins strictosidine synthase and berberine bridge enzyme in insect cell culture.

The heterologous expression of cDNAs encoding the alkaloid biosynthetic enzymes, strictosidine synthase [EC 4.3.3.2] from Rauvolfia serpentina and the berberine bridge enzyme [(S)-reticuline: oxygen oxidoreductase (methylene-bridge-forming), EC 1.5.3.9] from Eschscholtzia californica, has been achieved in a cell culture (Sf9) of the fall army worm, Spodoptera frugiperda, using a baculovirus-based expression system. The expression resulted in the overproduction of each plant enzyme in a catalytically active form. The maximal production attained was 4 mg purified, active enzyme per litre cell culture for both the strictosidine synthase and berberine bridge enzymes.

Amino Acid Sequence↗
PubMed1993

Migraine and migrainous stroke: risk factors and prognosis.

We compared epidemiologic and clinical data from 310 patients with migraine and 30 patients with acute migrainous stroke to identify factors predictive of migrainous stroke and assess the risk of future stroke in these two populations. We found no significant differences in gender ratio or in the frequency of smoking, estrogen use, hypertension, mitral valve prolapse, or family history of migraine between the two groups. A history of migraine with aura was significantly more common in the migrainous stroke group (24 of 30 [80%] versus 142 of 310 [46%]; p < 0.001), as was a history of prior stroke (nine of 30 [30%] versus four of 310 [1.3%]; p < 0.001). We followed 173 of the migraine patients for at least 1 year and a mean of 35.8 months, and no strokes occurred in this group. We followed 28 of the migrainous stroke patients for a mean of 25.3 months, and there were six recurrent strokes in that group, all again migraine-associated. Migrainous stroke is more common in individuals with aura than in those who are aura-free, but this association is of little value in attempting to distinguish patients destined for migrainous stroke from the migraine population at large. Patients with a history of migraine-associated stroke are at significantly increased risk for recurrent stroke.

Acute Disease↗
PubMed1993

[Treatment of pancreatic injuries. Study of a series of 34 patients].

Routine retrograde imaging of Wirsung's duct, an essential investigation of pancreatic injuries, should be carried out preoperatively and, in case of failure of the intervention, intraoperatively. Whereas simple drainage is sufficient treatment for injuries to the pancreatic parenchyma, lesions of Wirsung's duct require either duodeno-cephalic pancreatectomy or left pancreatic resection, depending on the site of the ductal wound, conservative treatment carrying the major risk of a post-traumatic acute pancreatitis with its particularly elevated mortality rate. Of the 34 cases, reported: 24 (70.6%) were treated by resection: 3 by duodenocephalic pancreatectomy and 21 by left pancreas resection, 6 (17.6%) by suture of the parenchyma and contact drainage and 4 (11.8%) by drainage of Wirsung's duct by catheter or excluded loop in Y. Mortality was 14.7% (5 of the 34 patients). Complications included pseudocysts requiring operative removal in 3 of the 6 patients treated by suture-drainage, and severe sepsis in 5 patients with a fatal outcome in 3 cases. Treatment was unsuccessful in 2 of the 4 patients treated by drainage by catheter or excluded loop in Y, whereas mortality was nil after pancreatic resection.

Adult↗
PubMed1993

[The content of hemoglobin in the blood and the abundant and trace elements in blood plasma and erythrocytes of sheep, fallow deer, dwarf goats and reindeer].

Of the 4 species, the blood of fallow deer had the highest concentration of Hb (10.9 +/- 0.7) and that of pygmy goats (6.5 +/- 1.4 mmol/l) the lowest. The highest concentration of protein in the plasma was found in the reindeer (81.2 +/- 2.1) and the lowest in the pygmy goats (59.1 +/- 4.3 g/l). High values of ascorbic acid were recorded in the reindeer (16.4 +/- 2.4) and in the Finnish sheep (16.3 +/- 2.5 micrograms/ml). There existed some differences in the concentrations of Na, K, Ca, Mg, Pa, Fe, Cu and Zn in the plasma of the sheep of 7 different breeds under similar nutritional conditions. The erythrocytes of the sheep of 3 breeds and that of fallow deer, of pygmy goats and of reindeer uniformly had a low Na- and a high K-concentration. The Ca-concentration of the erythrocytes of the sheep of most breeds and that of the fallow deer and pygmy goats was very low, that of Mg and Zn was higher than in the plasma.

Animals↗
PubMed1992

The jasmonate precursor, 12-oxo-phytodienoic acid, induces phytoalexin synthesis in Petroselinum crispum cell cultures.

The pentacyclic biosynthetic precursor of jasmonic acid, 12-oxo-phytodienoic acid, was found to induce synthesis of the major flavonoid, apiin, in cell suspension cultures of Petroselinum crispum. The accumulation of apiin was preceded by an increase in the relative levels of poly (A)+ RNAs that code for the flavonoid biosynthetic enzymes phenylalanine ammonia lyase, 4-coumarate:CoA ligase and chalcone synthase, Poly (A)+ RNAs reached maximal levels at approximately 4-6 h after the addition of elicitor while flavonoids continued to accumulate in the cultures for at least 6 days. 12-Oxo-phytodienoic acid is the first pentacyclic precursor in the jasmonic acid biosynthetic chain which functions as a signal transducer for phytoalexin induction.

Blotting, Northern↗
PubMed1992

Pitfalls in the histochemical demonstration of alpha-glucan phosphorylase activity in glycogen-depleted skeletal muscle fibres.

In the present communication, an investigation is described into the reliability of histochemical methods for the demonstration of alpha-glucan phosphorylase activity in glycogen-depleted skeletal muscle fibres. Human skeletal muscles with glycogen-depleted fibres from patients with diseases of the neuromuscular system and from subjects who had suffered from malignant hyperthermia were used for the study. The location of phosphorylase activity and glycogen was demonstrated with histochemical techniques. Biochemical techniques were used to assay the activity of phosphorylase and the content of glycogen. Biochemical determinations of phosphorylase activity did frequently not reveal significant differences between glycogen-depleted and non-depleted skeletal muscle fibres. In contrast, all histochemical methods investigated, showed little or no phosphorylase activity in the glycogen depleted fibres, indicating that none of the existing histochemical methods revealed reliable staining results in these fibres. Owing to the invalid staining results of the histochemical methods for glycogen-depleted muscle fibres, it is necessary that for metabolic studies a biochemical assay for phosphorylase activity is also to be performed.

Glycogen↗
PubMed1992

[The content of DNA, RNA and protein and the fresh weight:DNA, protein:DNA and RNA:DNA ratios in tissue of male calves, bulls, short-scrotum bulls and oxen during the growth period].

In male calves, in bulls, in short scrotum bulls and in oxen of different age the content of DNA, RNA and protein in various tissues (cerebrum, cerebellum, spinal cord, ventricles, lung, liver, cortex of the kidney, spleen, testicles, M. semimembranosus) was analysed. The fresh weight: DNA-, the protein: DNA- and the RNA: DNA-ratios were calculated. In the age of 78 weeks the short scrotum bulls had a body weight of 577 +/- 44, the bulls of 550 +/- 21 and the oxen of 462 +/- 41 kg. The testicles of the short scrotum bulls were smaller than that of the bulls. The differences in the content of DNA, RNA and protein per g tissue between male calves, bulls, short scrotum bulls and oxen of the same age were in part significant. The total content of DNA, of RNA and of protein for the 78 weeks old as well as the number of nuclei of the lung, the liver, the spleen and the testicles for the 6 and 78 weeks old animals were calculated. The biochemical parameters can be used for the characterization of the inhibition of growth of the different organs of calves and cattle by malnutrition and diseases.

Animals↗
PubMed1991

[The content of beta-carotene, vitamin A and ascorbic acid in different tissues of bulls, short-scrotum bulls and oxen of different body weights].

Analyses of the liver of bulls of different age show, that the concentration of beta-carotene in the age of 6 to that of 25 weeks increased only from 0.43 +/- 0.16 to 1.66 +/- 0.27 and that of vitamin A from 11.49 +/- 5.87 to 13.90 +/- 5.21 micrograms/g fresh weight. The concentration of beta-carotene and of vitamin A in the testis of bulls and of short scrotum bulls up to an age of 15 weeks was similar; thereafter the concentration in the short scrotum bulls was higher. At an age of 72 weeks the concentration of vitamin A in the liver of bulls (219.17 +/- 51.86) was higher (p less than 0.01) than in that of the short scrotum bulls (144.11 +/- 27.79) and that of the oxen (135.51 +/- 41.26 micrograms/g fresh weight). Analyses of the concentration of ascorbic acid in 8 different tissues of bulls and short scrotum bulls at 6 various periods show, that the highest values mostly were found in December.

Animals↗