Recommended dietary allowances (RDA) in the dietary management of children and adolescents with IDDM: an unfeasible target or an achievable cornerstone?

A diet in line with RDAs is seldom achieved by IDDM patients. High post-prandial glucose levels are often attributed to food excess rather than to inadequate insulin doses. Lower dietary CHO with greater fat (in particular SFA) and protein are progressively scheduled instead of increasing insulin units. We studied 194 IDDM patients (1-23 yr) on a diet conforming to RDAs with a restriction of sucrose and without a quantitative approach and exchange lists of food for one year. The diet consisted of a high intake of starchy foods and vegetables and a restricted amount of animal products. HbA1c mean values of the year were used as an indicator of metabolic control. The mean daily insulin dose was 0.53 U/kg in patients with diabetes duration (DD) < 2 yr and 0.81 U/kg in those with DD > 2 yr. Mean annual HbA1c was 7.1 +/- 0.9%. The prevalence of obesity was low (5.7%). Adolescent females were more obese than males. A dietary approach in line with RDA requirements, that may help prevent any complications related to an inappropriate diet pattern, coupled with a dynamic insulin adjustment, is the first-line intervention to prevent complications in IDDM patients.

Flow-dependent vasodilation in the coronary circulation: alterations in diseased states

Flow-dependent vasodilation has been recognized to play an important role in the perfusion of the myocardium and the occurrence of myocardial ischaemia. In the past few years, the role of the endothelium in the regulation of coronary artery dimensions has gained a lot of attraction. Changes in coronary artery size are caused through the contraction and relaxation of the smooth musculature within the vessel wall. Vasoactive substances released from the endothelium play a crucial role in the regulation of vessel size and coronary vasomotor tone. During physiologic exercise, normal coronary arteries dilate, whereas stenotic arteries constrict. This abnormal behaviour of the stenotic artery has been associated with the occurrence of myocardial ischaemia, and has been thought to be either due to: endothelial dysfunction with reduced release or production of the endothelial derived relaxant factor (EDRF); an increased sympathetic stimulation during exercise; enhanced platelet aggregation with release of thromboxane A2 and serotonin; and/or a passive collapse of the disease-free vessel segment within the stenosis when blood-flow velocity increases during exercise. Thus, a diseased coronary endothelium may have a dramatic effect on the function of the coronary arteries, and may cause or contribute to the occurrence of myocardial ischaemia under high-demand situations, e.g. physical exercise or mental stress. Changes in flow-dependent vasodilation have been described in various disease states, e.g. hypercholesterolaemia, hypertension, diabetes mellitus, but also in valvular heart disease, heart failure and transplantation. Most of these alterations are due to functional changes of the endothelium, but vascular remodelling of the coronary arteries with thickening of the intima and an enlargement of the artery may affect these functional changes importantly.

Cardiac risk after mediastinal irradiation for Hodgkin's disease

PURPOSE

To evaluate the risk of cardiac lesions after conventionally fractionated irradiation (Rt) of the mediastine with or without chemotherapy (Ct) in patients with Hodgkin's disease (HD) and to relate them to known cardiovascular risk factors.

PATIENTS AND METHODS

Between 1964 and 1992, 352 (total group) patients with HD were treated with curative intention using Rt with or without Ct including the mediastine and had a follow-up of at least 1 year. More than 96% of the patients had a complete follow-up. One hundred forty-four patients (64% of the living patients, heart study group) have regular follow-up in our department and had a special heart examination including rest and exercise ECG, echocardiography and myocardial perfusion scintigraphy (112 patients). Doses per fraction in the anterior heart region were between 1.3 and 2.1 Gy. Total doses were between 30.0 and 42.0 Gy in 93% of cases. The mean length of follow-up was 11.2 years (range 1.0-31.5 years). Other cardiovascular risk factors evaluated were body mass index, blood pressure, smoking history, diabetes mellitus, hypercholesterolemia and history of coronary artery disease before Rt.

RESULTS

In the total group, the risk of fatal cardiac ischemic events and/or of sudden unexpected death was significantly higher than expected with a relative risk of 4.2 for myocardial infarction and 6.7 for myocardial infarction or sudden death. In female patients and in patients without other cardiovascular risk factors, the risk of fatal or non-fatal ischemic cardiac events was not significantly different from the expected value. In the subgroup with no cardiovascular risk factors and treatment without Ct, there was no ischemic or other major cardiac event. Echocardiography showed valvular thickenings in a large amount of the patients (the cumulative risk after 30-year follow-up was above 60%) but mostly without hemodynamic disturbance. In patients without hypertension and without coronary artery disease, findings of perfusion scintigraphy and echocardiographic evaluation of systolic and diastolic function were normal. Treatment with Ct was not a significant risk factor for cardiac events but the number of patients whose treatment included adriamycin and with a follow-up exceeding 10 years is to low for a definitive evaluation.

CONCLUSIONS

In patients without the usual cardiovascular risk factors (smoking, hypertension, obesity, hypercholesterolemia, diabetes mellitus) the risk of serious cardiac lesions after conventionally fractionated irradiation of the mediastinum with an intermediate total dose between 30 and 40 Gy is low. Also the cardiac risk of the combination of this irradiation with Ct including adriamycin with a total dose between 200 and 300 mg/m2 seems low but further long-term observation is necessary.

Immunohistochemistry of matrix metalloproteinases (MMP), their substrates, and their inhibitors (TIMP) during trophoblast invasion in the human placenta

The invasion of extravillous trophoblast cells into the maternal endometrium is one of the key events in human placentation. The ability of these cells to infiltrate the uterine wall and to anchor the placenta to it as well as their ability to infiltrate and to adjust utero-placental vessels to pregnancy depends, among other things, on their ability to secrete enzymes that degrade the extracellular matrix. Most of the latter enzymes belong to the family of matrix metalloproteinases. Their activity is regulated by the tissue inhibitors of matrix metalloproteinases. We have studied the distribution patterns of matrix metalloproteinases-1, -2, -3, and -9 and their inhibitors TIMP-1 and TIMP-2 as compared to the distribution of their substrates along the invasive pathway of extravillous trophoblast of 1st, 2nd, and 3rd trimester placentas by means of light microscopy on paraffin and cryostat sections as well as at the ultrastructural level (only 3rd trimester placenta). The comparison of different methods proved to be necessary, since the immunohistochemical distribution patterns of these soluble enzymes are considerably influenced by the pretreatment of tissues. All three methods revealed immunoreactivities of both, proteinases and their inhibitors, not only intracellularly in the extravillous trophoblast but also extracellularly in its surrounding matrix, the distribution patterns depending on the stage of pregnancy and on the degree of differentiation of trophoblast cells along their invasive pathway. Within the extracellular matrix, immunolocalization of matrix metalloproteinases as well as their inhibitors showed a specific relation to certain extracellular matrix molecules.

The extent of trophoblast invasion in the preplacental vasculature of the guinea-pig

Pregnancy-induced structural changes in spiral arteries seem to be a prerequisite for successful fetal outcome in humans. It is unknown whether these changes also occur in other preplacental vessels (radial and arcuate arteries) in normal pregnancies. Since the radial and arcuate arteries need to dilate in order to accommodate the increase in placental blood flow during pregnancy, it is expected that they are also invaded by trophoblast and respond with structural changes. The objective of the present study was to evaluate the extent of trophoblast invasion in the guinea-pig preplacental vasculature and its effect on the vascular structure of mesometrial, myometrial and arcade arteries. Under general anaesthesia the vascular system of non- (n = 4), mid- (n = 4) and late- (n = 8) pregnant guinea-pigs was fixed by immersion or perfusion. Cross-sections of immersion-fixed mesometrial and arcade arteries were stained with toluidine blue. Cross-sections of perfusion-fixed mesometrial, myometrial and arcade arteries were stained with haematoxylin-eosin, Elastica van Gieson staining and antibodies against alpha-smooth-muscle-actin (ASMA), cytokeratin and factor VIII, to detect vascular smooth muscle, trophoblastic, and endothelial cells, respectively. In addition, the external and internal vascular circumference of sections from perfusion-fixed tissue was determined. All cross-sections were evaluated by light microscopy. In the course of pregnancy, progressive endothelial swelling, disappearance of the elastic lamina interna and disarrangement of the tunica media were observed in the myometrial and throughout the mesometrial arteries up to the junction with the arcade arteries. These changes coincided the migration of keratin-positive staining giant cells. It is concluded that in normal guinea-pig pregnancy, structural changes occur in the entire mesometrial artery and at least a part of the myometrial artery, although such changes were not seen in the arcade artery.

Neopterin plasma concentrations predict the course of severe acute pancreatitis

In a prospective, descriptive study in 25 patients with acute pancreatitis neopterin plasma concentrations were found to be associated with the severity of the disease, which was assessed using weights of the worst 17 physiological abnormalities of the APACHE-III score over a 24 h-period after hospital admission. Neopterin concentrations were higher in severe pancreatitis (n = 10) compared to mild disease, and there existed a positive exponential correlation between neopterin and the Acute Physiology Score (r = 0.66). Higher neopterin concentrations were associated with the development of multiple organ failure (p = 0.012) and death (p = 0.019). At a cut-off concentration of 12 nmol/l the sensitivity (80%) and specificity (100%) of neopterin for the discrimination between mild and severe clinical course of pancreatitis was more accurate than C-reactive protein at a risk threshold of 1.2 g/l (70% and 87%). Development of pancreatic necrosis was associated with higher neopterin concentrations than edematous pancreatitis (p < 0.001).

Oxygen and placental villous development: origins of fetal hypoxia

The increasing practice of preterm delivery in the fetal interest for conditions such as pre-eclampsia or intrauterine growth restriction (IUGR) has provided an opportunity to study placental structure in pregnancies with prenatal evidence of fetal compromise. These data suggest that the origin of fetal hypoxia in IUGR with absent end-diastolic flow in the umbilical arteries is due to a failure of oxygen transport from intervillous space to umbilical vein. Failure of the fetoplacental circulation to extract oxygen from the intervillous space under such circumstances means intervillous PO2 is closer to maternal arterial values than under physiological conditions. Correspondingly the placental villi are chronically exposed to a higher oxygen tension than under normal circumstances--the term ¿hyperoxia', relative to normal intraplacental oxygenation, is proposed to describe this situation. Both the trophoblast and villous core react to increased oxygen despite fetal hypoxia. These results challenge the generally accepted concept of ¿placental hypoxia' in all circumstances where fetal hypoxia might arise. Therefore three categories are proposed for the origins of fetal hypoxia: (1) preplacental hypoxia; (2) uteroplacental hypoxia; and (3) postplacental hypoxia. Examples for these three disease states are listed in this review and the structural reaction patterns of placental villi to these differences in oxygenation are discussed.

[Anemia and heart function]

Anemia typically leads to a state of hyperkinetic circulation with tachycardia, reduced peripheral resistance, increased stroke volume chamber dilatation, and finally to the development of left ventricular hypertrophy. These changes are usually well tolerated by patients with a healthy heart. In patients with heart diseases, however, anemia may lead to deterioration of ventricular performance and to increased morbidity and mortality respectively. Specific changes in cardiac function may arise depending on the causes of anemia such as myocardial iron deposition and dilatative cardiomyopathy in hemolytic anemia or alterations of homeostasis and reduction of cardiac function in renal anemia. With respect to cardiac function the cause of anemia must be corrected as far as possible and hemoglobin kept over a level of 10 g/dl. As far as renal anemia is concerned this goal can be reached by regular administration of erythropoietin and/or iron respectively.

Influence of a novel amino acid solution (enriched with the dipeptide glycyl-tyrosine) on plasma amino acid concentration of patients with acute renal failure

In this randomized, double-blind controlled study we compared the effect of parenteralnutrition with two different amino acid solutions on the plasma concentration of amino acids in 27 patients with acute renal failure. Fourteen patients received the new dipeptide-containing (glycyl-tyrosine) amino acid solution (AADI) in combination with glucose (60%) and fat (10%) as an 'all-in-one' solution over 120 h continuously via a central venous catheter. In the control group (AAST), parenteral nutrition with a standard amino acid solution in isonitrogenous and isocaloric form (0.7 g amino acids/kg BW/day and 25 kcal/kg BW/day) was administered to 13 patients over the same period of time. The administration of the dipeptide-containing amino acid solution caused a return to within the normal range of most of the amino acid concentrations which were decreased at the onset. A significant difference could be found between the AADI and AAST group for the achieved plasma concentrations of threonine (P < 0.01), phenylalanine (P<0.05), isoleucine (P<0.05), tryptophan (P<0.01) and ornithine (P<0.05), The phenylalanine/tyrosine ratio, did not change in the AADI group, while a marked increase was observed in the AAST group. (152.7 +/- 23.5 - 159.8 +/- 37.6 vs 172.6 +/- 24.6 - 310.6 +/- 136.7, respectively). The plasma concentration of glycyl-tyrosine was at the limit of detectability indicating rapid hydrolysis of the dipeptide in acute renal failure. These data suggest that the new dipeptide-containing amino acid solution offers a clear advantage over a standard amino acid formulation in correcting the amino acid imbalances in plasma of patients with ARF and is able to maintain normal tyrosine concentrations and phenylalanine/tyrosine ratio.

Preparation and gas chromatographic-mass spectrometric analysis of N-acetyl-O-trimethylsilyl derivatives of long-chain base residues of natural sphingomyelin

A procedure for the preparation of long-chain base residues of egg yolk, bovine milk and bovine brain sphingomyelin was developed. The bases were converted to N-acetyl-O-trimethylsilyl (TMS) derivatives before being submitted to gas chromatography and mass spectrometry. The chromatographic profile of the milk sample was complex with thirteen peaks, whereas the profiles of brain and egg yolk long-chain bases were simple and remarkably similar.

Coronary vasomotion after percutaneous transluminal coronary angioplasty depends on the severity of the culprit lesion

OBJECTIVES

This study sought to evaluate coronary vasomotor response to percutaneous transluminal coronary angioplasty (PTCA) and its influence on proximal and distal vessel diameters with regard to stenosis severity and coronary blood flow.

BACKGROUND

Coronary vasoconstriction of the distal vessel segment has been reported after PTCA. This vasoconstrictive effect was thought to be due to balloon-induced injury of the vessel wall, with release of local vasoconstrictors or stimulation of the sympathetic system with release of catecholamines, or both.

METHODS

Thirty-nine patients were prospectively studied before and after PTCA. Patients were classified into two groups according to the severity of the culprit lesion: group 1 = > or = 70% to < or = 85% diameter stenosis (n = 23); and group 2 = > 85% to < or = 95% diameter stenosis (n = 16). The coronary vessel diameter of the proximal and distal vessel segments as well as the minimal lumen diameter were determined by quantitative coronary angiography. In a subgroup of 16 patients, basal and maximal coronary flow velocity was measured before and after PTCA with the Doppler FloWire system.

RESULTS

The groups were comparable with regard to age, gender, serum cholesterol levels and medical therapy. The proximal vessel segment remained unchanged after PTCA in group 1 ([mean +/- SD] 0.9 +/- 3.5%, p = 0.8) but showed vasodilation in group 2 (+13.7 +/- 3.6%, p < 0.05). However, the distal segment showed vasoconstriction in group 1 (-6.7 +/- 2.0%, p < 0.01) and vasodilation in group 2 (+31 +/- 8.0%, p < 0.01). A significant correlation was found between the change in distal vessel diameter after PTCA and stenosis severity (r = 0.61, p < 0.0001). Changes in blood flow were directly correlated to stenosis severity (r = 0.85, p < 0.002); that is, rest flow increased after PTCA in narrow lesions but remained unchanged in moderate lesions. The diameter changes in the distal vessel segment after PTCA were significantly related to flow changes (r = 0.90, p < 0.0001). Coronary distending pressure of the distal vessel segment increased significantly in both groups; however, this increase was significantly greater in group 2 than in group 1 (55 +/- 4 vs. 14 +/- 3 mm Hg, p < 0.0001).

CONCLUSIONS

Coronary vasomotion of the proximal and distal vessel segments after PTCA depends on the severity of the culprit lesion; that is, vasoconstriction of the distal segment is found in patients with moderate lesions and vasodilation in those with severe lesions. Thus, vasomotion of the post-stenotic vessel segment depends on the severity of the culprit lesion and is influenced by changes in coronary flow or distending pressure, or both.

[Function of the residual myocardium after infarct and prognostic significance]

Changes of the left ventricle after myocardial infarction are characterized by geometric, structural, and vascular alterations, which have been summarized under the term "remodeling". This process takes place in the infarct region as well as in the surviving myocardium. Depending on to the size of infarction and the degree of neurohumoral activation, the left ventricle demonstrates diastolic dysfunction which may finally lead to systolic failure. The residual myocardium develops progressive myocyte hypertrophy and interstitial fibrosis. These structural alterations are due to changes in loading conditions and stimulation of the neurohumoral system with an activation of local paracrine and autocrine factors. Myocardial function can be assessed by different non-invasive (echocardiography, radionuclide ventriculography, magnetic resonance imaging, etc.) or invasive methods (e.g., simultaneous pressure-volume measurements). "Myocardial tagging" based on magnetic resonance imaging allows the assessment of 3D-motion of the left ventricle by labelling specific myocardial regions with a rectangular grid. A systolic "wringing" motion with clock-wise rotation at the base and counter-clockwise rotation at the apex has been described in normal subjects. In the ischemic myocardium, delayed relaxation with a prolonged back-rotation (untwisting) has been reported during early diastole, whereas decreased systolic contraction with delayed diastolic rotation has been observed in non-Q-wave infarction. In patients with anterolateral aneurysms, a complete loss of systolic rotation has been demonstrated. The prognostic significance of LV "remodeling" has been emphasized by several authors: The size of infarction, LV volume, LV ejection fraction, as well as the degree of neurohumoral activation have been identified as being associated with an unfavorable clinical outcome. Yearly mortality rates have been reported to range between 15 and 17% in patients with large infarcts and marked LV dilatation and between 3 and 7% in patients with small to medium-sized infarcts.

Carnitine palmitoyltransferase II deficiency: diagnosis by molecular analysis of blood

Four missense mutations have been reported to be associated with the typical, adult form of carnitine palmitoyltransferase II (CPT II) deficiency: Three amino acid substitutions (R631C. P50H and D553N) appear to be rare, while the S113L mutation was found to be common in a group of European patients with CPT II deficiency. We analyzed genomic DNA from 20 American patients with recurrent episodes of myoglobinuria as well as DNA from 10 normal controls in order to determine the frequency of the reported missense mutations in our patient population. The three previously described rare mutations were not found in our group of patients. The S113L mutation was found in 19 of our patients: 5 patients were homozygous, 14 patients were heterozygous. Given the high frequency of this mutation in our series of patients we concluded that the clinical diagnosis of CPT II deficiency can be confirmed by a 'blood test' without resorting to a muscle biopsy.

Elevated plasma levels of soluble tumor necrosis factor receptor (sTNFRp60) reflect severity of acute pancreatitis

OBJECTIVE

To investigate the role of activated leukocytes in acute pancreatitis, we measured soluble receptors of tumour necrosis factor alpha (sTNFR, p60 subtype) in plasma and evaluated the association of sTNFR with the clinical severity of the disease.

DESIGN

Prospective, descriptive study.

SETTING

A medical intensive care unit (ICU) in a university hospital.

PATIENTS

25 consecutive ICU admissions of adult patients with acute pancreatitis.

MEASUREMENTS AND RESULTS

The clinical severity of the disease was assessed using weights for the worst 17 physiological abnormalities of the Acute Physiology and Chronic Health Evaluation III score over a 24-h period after admission. According to the sum of these weights (giving the Acute Physiology Score, APS) patients were divided into a group with mild pancreatitis (APS < 25) and into a group with severe pancreatitis (APS > or = 25). Soluble TNFR was determined in plasma using an enzyme-linked immunoadsorbent assay. In patients with clinically severe pancreatitis, plasma sTNFR concentrations of 8.8 (16) ng/ ml (median, interquartile range) were significantly higher when compared to patients with mild disease [2.7 (1.5) ng/ml; p < 0.0001]. The sensitivity and specificity of sTNFR plasma concentrations (cutoff point at 5 ng/ml) for the prediction of severe pancreatitis were 90 and 100%, respectively. A highly positive correlation between sTNFR and deviations of physiological parameters from normal (APS score) was demonstrated (r = 0.81). The development of multiple organ failure (MOF) and death was associated with significantly higher sTNFR levels when compared to patients without MOF and survivors [16.4 (17) vs 3.2 (2) ng/ml, p = 0.0014 and 16.0 (18) vs 3.3 (4) ng/ml, p = 0.016, respectively]. For evidence of necrotizing pancreatitis, plasma C-reactive protein concentrations were measured and a significant exponential regression was found with sTNFR (r = 0.77, p < 0.0001). Patients developing pancreatic necrosis, as demonstrated by contrast-enhanced computed tomography, had significantly higher sTNFR concentrations when compared to patients with edematous pancreatitis [9.1 (17) vs 3.2 (2) ng/ml, p = 0.0018).

CONCLUSION

The p60 subtype of soluble TNFR is elevated in the plasma of patients with clinically severe acute pancreatitis. This elevation is positively correlated to abnormalities in physiological parameters, development of MOF, and mortality. The association with pancreatic necrosis suggests that, by mediating the effects of TNF, TNFRp60 reflects inflammatory tissue damage leading to severe systemic complications.

Classification of human placental stem villi: review of structural and functional aspects

The stem villi of the human placenta represent the central branches of the villous trees. They are characterized by a condensed fibrous stroma in which the fetal arteries and veins as well as the arterioles and venules are embedded. Functionally they are accepted as the mechanically supporting structures of the villous trees, and they are supposed to control fetal blood flow to the maternofetal exchange area, which is located in the peripheral villi. To obtain further insights into the functions of the stem villi, the recent literature has been reviewed, and some immunohistochemical, ultrastructural, and reconstruction studies have been added. These new studies were aimed at identifying immunohistochemically different subtypes of stem villi, their branching patterns, the distribution of macrophages, the stromal proliferation patterns, and the differentiation of extravascular stromal cells. Our findings demonstrate that the stem villi and their precursors, the immature intermediate villi, can selectively be identified by anti-gamma-smooth muscle (sm) actin staining. Furthermore, the existence of three different subtypes of stem villi is shown; these differ regarding the presence and distribution of gamma-sm actin-positive cells. These cells were immunohistochemically and ultrastructurally identified as smooth muscle cells and myofibroblasts. Increasingly complex coexpression patterns of cytoskeletal proteins reflect a clearly defined differentiation gradient of extravascular stromal cells, which covers the whole range of an undifferentiated germinative layer beneath the trophoblast to highly differentiated myofibroblasts surrounding the medias of the stem vessels. Possible functions of the extravascular contractile system include the regulation of villous turgor and the control of intervillous blood flow impedance.

Location of insulin receptors in the placenta and its progenitor tissues

The insulin receptor gene is constitutively expressed, so the presence of insulin receptor proteins might be expected on all mammalian tissues, with the plasma membrane as the predominant site of receptor location. Results reviewed here indicate that insulin receptors are also present in all placental tissues and the placenta's progenitor tissues and cells, i.e., oocytes, spermatozoa, and preimplantation embryos, in most of the species studied. Receptor densities, however, vary among individual cells and cell types and at various developmental stages. Three aspects deserve emphasis. 1) In human placenta, the insulin receptor distribution pattern is characterized by a spatiotemporal change between first trimester and term. At the beginning of pregnancy, insulin receptors are found predominantly on the maternal side (apical membrane of syncytiotrophoblast, low density on cytotrophoblast); at term, however, they are on the fetal side (lining the fetal vessels). This suggests that, in the first trimester, maternal insulin regulates insulin-dependent processes, whereas, at term, it must be fetal insulin mainly controlling these processes. 2) The majority of insulin receptors is expressed on structures that are currently assumed to drive placental growth, i.e., syncytial sprouts and mesenchymal villi in first-trimester placentas and fetal endothelium at term. Therefore, we hypothesize a growth-promoting function, among others, of insulin on the placenta. 3) At present, no histologic evidence is available to demonstrate insulin receptors in structures commonly associated with receptor-mediated endocytosis. Whether placental insulin receptors are internalized, therefore, awaits clarification.

Pressure dependence of so-called transtrophoblastic channels during fetal perfusion of human placental villi

To test the influence of perfusion pressures on structural preservation of human placental villi and on the dilatation of the so-called transtrophoblastic channels, cotyledons of 32 term human placentas have been perfused in vitro. Periods of perfusion with isotonic Ringer solution under various arterial and venous hydrostatic pressures were followed by perfusion fixation. In some experiments, lanthanum hydroxide as an extracellular marker was added to the fixative. Distention of the fetal vascular system, stromal edema and continuity, as well as trophoblastic vacuolization were studied via electron microscopy with subsequent morphometry. The findings suggest that arterial hydrostatic pressures in the perfusion system of about 80 cm H2O are needed to guarantee homogeneous perfusion of the fetal vascular system. To avoid stromal edema and trophoblastic vacuolization, venous hydrostatic pressures of 4 cm H2O and arterial hydrostatic pressures of 80 cm H2O should not be exceeded. It is concluded that the trophoblastic vacuoles are dilated segments of the so-called transtrophoblastic channels. The functional importance of in vivo variations of fetal intravascular hydrostatic pressure for the dilatation of transtrophoblastic channels and for fetal water balance is discussed.

[Diuretics in the treatment of heart failure: current pathophysiological aspects]

From a pathophysiologic point of view heart failure can be divided into systolic and diastolic dysfunction. Systolic dysfunction is characterized by a decreased ejection fraction and increased chamber volume which can be typically found in young people with congestive cardiomyopathy. Diastolic dysfunction is associated with an enhanced filling pressure but with a normal systolic pump function. This disorder can be typically found in elderly patients with myocardial hypertrophy. Treatment of congestive heart failure includes. 1.) reduction of central blood volume (preload reduction) 2.) decrease of peripheral resistance afterload reduction) 3.) regression of myocardial hypertrophy (improving myocardial stiffness) 4.) maintenance of atrial contraction (atrial kick) 5.) decrease of heart rate (prolongation of diastolic filling time and increase in contractility) 6.) improvement of LV relaxation (positive lusitropic effect) and 7.) prevention of myocardial ischemia (improvement in contractility and relaxation). The primary goal of medical therapy is symptomatic improvement. Reduction in morbidity and mortality is only a secondary consideration. To achieve this goal ACE-inhibitors and in certain cases betablockers (cave: neg. inotropic action) are suited best. Additionally, digitalis-especially in the presence of atrial fibrillation- and vasodilators can be used to further improve quality of life. In the case of severe heart failure with or without atrial fibrillation oral anticoagulation is indicated to prevent systemic embolication. Diuretics are often used for symptomatic improvement but have no effect on long-term survival. Aldosterone antagonists (e.g, spironolactone) have a beneficial effect on LV remodeling and probably also on mortality. The role of endothelin antagonists and atriopeptidase inhibitors in the treatment of heart failure are not yet clear.

Identification and quantification of Bifidobacterium species isolated from food with genus-specific 16S rRNA-targeted probes by colony hybridization and PCR

A Bifidobacterium genus-specific target sequence in the V9 variable region of the 16S rRNA has been elaborated and was used to develop a hybridization probe. The specificity of this probe, named lm3 (5'-CGGGTGCTI*CCCACTTTCATG-3'), was used to identify all known type strains and distinguish them from other bacteria. All of the 30 type strains of Bifidobacterium which are available at the German culture collection Deutsche Sammlung von Mikroorganismen und Zellkulturen, 6 commercially available production strains, and 34 closely related relevant strains (as negative controls) were tested. All tested bifidobacteria showed distinct positive signals by colony hybridization, whereas all negative controls showed no distinct dots except Gardnerella vaginalis DSM4944 and Propionibacterium freudenreichii subsp. shermanii DSM4902, which gave slight signals. Furthermore, we established a method for isolation and identification of bifidobacteria from food by using a PCR assay without prior isolation of DNA but breaking the cells with proteinase K. By this method, all Bifidobacterium strains lead to a DNA product of the expected size. We also established a quick assay to quantitatively measure Bifidobacterium counts in food and feces by dilution plating and colony hybridization. We were able to demonstrate that 2.1 x 10(6) to 2.3 x 10(7) colonies/g of sour milk containing bifidobacteria hybridized with the specific nucleotide probe. With these two methods, genus-specific colony hybridization and genus-specific PCR, it is now possible to readily and accurately detect any bifidobacteria in food and fecal samples and to discriminate between them and members of other genera.