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Biomedical subjects

M Ludwig

Publications and source records attributed to M Ludwig.

At least 199 records · Page 11Linked to original sources

[Long-term follow-up after acute myocardial infarct cause by non-arteriosclerotic spontaneous coronary artery dissection].

Spontaneous coronary artery dissection is a rare cause of acute myocardial infarction, primarily in young women. The etiology of dissections is still under discussion. Possible factors are inflammation, changes of flow dynamics, and preexisting intima lesions. We report on two young women, 49 and 30 years of age, who suffered and acute anterior wall infarction. Coronary angiography confirmed diagnosis of spontaneous coronary artery dissection of the LAD in the acute an subacute phase of acute myocardial infarction. The patients suffered no further cardiac events at long-term follow-up of up to 9 years.

Adult↗

Transurethral laser therapy and urinary tract infections.

To date transurethral laser ablation of the prostate (TULAP) in benign prostatic hyperplasia (BPH) is the commonest form of transurethral laser surgery. The invention of the so-called "sidefire" laser fibre was the prerequisite condition for effective transurethral laser ablation of the prostate. Since the first transurethral laser ablation in human BPH was performed by Costello in September 1990, a multitude of urologists have adopted this technique. In the meantime, a great many studies have been carried out and a lot of data have been published. The initial, to some extent euphoric, enthusiasm of some urologists as well as some patients, especially in the USA and Europe, has turned into a more critical reflection. There is no doubt at all that TULAP is a feasible alternative treatment method with reasonable results. Especially in the high-risk patient, there is neither severe blood loss nor an uptake of irrigation fluid. It is also beneficial to allow unlimited treatment in patients on anticoagulant medication. Nevertheless, the value of TULAP in comparison to transurethral electroresection of the prostate (TURP), generally accepted as the "gold-standard" in the surgical therapy of BPH, remains unclear. A final assessment will only be possible when further data on mortality, short and long term morbidity and outcome with this method have been presented. Strong evidence exists that the operation can be performed without blood loss and uptake of irrigation fluid. A further advantage seems to be preservation of sexual function, especially anterograde ejaculation in the majority of patients, in comparison to the "gold-standard" TURP. In most studies, the value of TULAP is further compared with regard to the elimination of obstruction by means of pressure-flow-studies. The aspect most frequently neglected by all investigators to date is the frequency and severity of urinary tract infections (UTI) in patients in whom TULAP is performed. Basically, UTI in the form of cystitis, ascending infections such as male adnexitis or pyelonephritis, prostatitis of the remaining parts of the prostate and catheter-induced urethritis are associated with transurethral surgery in general. Certain data indicate an age-related frequency of UTI. From a rate of approximately 1% of UTI in infants, the frequency rises to 30% in the 8th decade of life. According to these data, one can expect that in a study of TULAP in high risk patients, most of whom are elderly, a large number present for surgery with a preexisting UTI. Other data demonstrate that after 4.5 days 50% and more of patients with an indwelling catheter develop an ascending UTI, although a closed urinary drainage system has been used. In most cases enterobacteriaceae, in 80% Escherichia coli, are detected. Especially in TULAP, a period of prolonged catheterisation has to be expected in the majority of patients. The risk of UTI in the perioperative phase is therefore expected to be higher. There are several higher risks and possibilities of complications in transurethral surgery in patients with UTI. Taking this into account, all our patients routinely undergo low dose antibiotic prophylactic treatment. The frequency of infections of the remaining parts of the prostate after prostatic surgery is strongly correlated to the flow characteristics in the prostatic urethra and to the amount of destruction of the prostatic tissue. Here are further reasons for a higher risk of infection after TULAP. Due to the fact that the prostatic tissue is not removed by a clear cut, but coagulated by laser beam, a rough surface due to tissue necrosis results. This is an ideal culture medium for bacteria aggravated by the disturbed laminar flow in the prostatic urethra, which favours an intraprostatic reflux of infected urine. There is evidence that UTI are the most important factor of morbidity during the first weeks after TULAP because of their bothersome symptoms.(ABSTRACT TRUNCATED)

Aged↗

Chlamydia trachomatis antibodies in serum and ejaculate of male patients without acute urethritis.

In a prospective study, the prevalence of specific antibodies against Chlamydia trachomatis in serum and seminal plasma evaluated by a genus specific immunofluorescence test in 101 men without acute urethritis was investigated. The results were compared to the clinical diagnosis, cell culture of urethral swabs, demonstration of DNA particles by Polymerase Chain Reaction (PCR) in the ejaculate and signs of genital inflammation by counting peroxidase-positive leukocytes and elastase level in semen. The objective was to evaluate the significance of chlamydial antibodies in genital infection. Serum specific IgG and IgA antibodies were found in 26% and 15%, respectively; seminal IgG and IgA antibodies were present in 6% and 7%, respectively. Serum specific antibodies were not associated with the clinical diagnosis of infection nor with C. trachomatis cell culture, PCR findings, peroxidase positive leukocytes or PMN-elastase level. It is concluded that serum antibodies are not useful in detecting a chlamydial infection. Seminal plasma antibodies were not correlated with the clinical diagnosis of infection, positive cell culture, PMN-elastase levels and leukocytes in semen. However, a significant correlation was found for positive PCR in the ejaculate (p < 0.001 for IgG, p < 0.05 for IgA, p < 0.001 when combined). Though seminal antibodies may be more useful in detecting ascended or occult chlamydial infection, their significance remains unclear, their absence does not exclude chlamydial infection. In particular, the biological significance of locally derived IgA needs further evaluation.

Acute Disease↗

[Pregnancy and extreme myomatous uterus--conservative management].

The management of a pregnancy complicated by uterus myomatosus remains being controversially discussed. Myomectomy early in pregnancy is opposed by exspectative management with myomectomy subsequent to the post partum period. Therapeutic abortion and exstirpation of the gravid uterus represent only hypothetical but not reasonable alternatives. Complications like ureteral obstruction, sepsis, and torsion of the uterus with subperimetrial bleeding as a cause of fever of unknown origin may occur. Rapid growth of a fibromatous uterus in pregnancy may call for a biopsy. Two cases are presented to demonstrate that with intensive pregnancy surveillance exspectative management is justified and may lead to successful confinement of the pregnancy.

Adult↗

Vascular wall thickness in hypertension: the Perindopril Regression of Vascular Thickening European Community Trial: PROTECT.

A high prevalence of increased intima/media thickness of the arterial wall has been documented in hypertension. These alterations in vascular wall structure may be potent determinants for the promotion of the development of atherosclerosis. Direct histologic data from animal models of hypertension, and indirect data from hypertensive patients, have demonstrated a marked regression of increased intima/media thickness by angiotensin-converting enzyme (ACE) inhibition. Long-term effects of ACE inhibition on structural wall changes in humans have not been examined. Therefore, a multicenter, randomized, double-blind European trial was designed to compare the effects of the ACE inhibitor perindopril and the diuretic hydrochlorothiazide in slowing or reversing progression of increased intima/media thickness of carotid and femoral arteries in hypertensive patients. A total of 800 patients at 17 clinical centers in 7 European countries, aged 35-65 years, with hypertension and ultrasonographically proven intima/media thickness > or = 0.8 mm of the common carotid artery will be randomly assigned to receive in a double-blind fashion either perindopril or hydrochlorothiazide and will be followed for 24 months. High resolution duplex sonography will be used to quantify intima/media thickness at baseline and twice a year during follow-up. A change of 0.1 mm of intima/media thickness from baseline is considered to be detectable, and the standard deviations of the changes from baseline are expected not to be higher than 0.2 mm. The primary endpoint of the study is the comparison of changes in intima/media thickness of the common carotid artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Molecular comparison of carbonic anhydrase from Flaveria species demonstrating different photosynthetic pathways.

During the evolution of C4 plants from C3 plants, both the function and intracellular location of carbonic anhydrase (CA) have changed. To determine whether these changes are due to changes at the molecular level, we have studied the cDNA sequences and the expression of CA from Flaveria species demonstrating different photosynthetic pathways. In leaf extracts from F. bidentis (C4), F. brownii (C4-like), F. linearis (C3-C4) and F. pringlei (C3), two polypeptides of M(r) 31 kDa and 35 kDa cross-reacted with anti-spinach CA antibodies. However, the relative labelling intensities of the two polypeptides differed depending on the species. Northern blot analysis indicated at least two CA transcripts are present in each Flaveria species with sizes ranging from 1.1 to 1.6 kb. Carbonic anhydrase cDNAs from all four Flaveria species studied encode an open reading frame for a polypeptide of 35-36 kDa. The amino acid sequences deduced from all four Flaveria cDNAs share at least 70% homology with the sequences of other dicot CAs. The F. bidentis (C4) CA sequence was found to be the least similar of the Flaveria proteins and, as most of the sequence dissimilarity was found in the first third of the CA molecule, these differences may be involved in the intracellular targeting of CA. A neighbour-joining tree inferred from CA amino acid sequences showed that the Flaveria CAs cluster with other dicot CAs forming a group distinct from those of monocot CAs and prokaryotic and Chlamydomonas periplasmic CAs.

Amino Acid Sequence↗

Comparison of carbon dioxide, octenol and a host-odour as mosquito attractants in the Upper Rhine Valley, Germany.

Field studies were conducted in the Upper Rhine Valley to determine the responses of mosquitoes to CDC traps baited with either CO2, octenol, light or paired combinations of these. Among eight mosquito species caught, the attractant effect on trap catches was studied in the four most abundant: Aedes vexans, Ae.rossicus, Ae.cinereus and Culex pipiens. Traps baited only with light or octenol caught few mosquitoes, whereas many were caught by traps baited with CO2 alone or in combination with either of the other candidate attractants. CO2 baited traps, with or without light, caught the most Aedes. The combination of CO2 and octenol attracted most Cx pipiens, but this apparent synergy was not significant. Using a caged hamster compared to CO2 as bait in a CDC light-trap with only intermittent fan suction, the hamster attracted less mosquitoes than CO2 emitted at a rate of 225 g/h on days 1 and 2, whereas on days 3 and 4 the smell from the hamster's cage became significantly more attractive than this rate of CO2 for all species of mosquitoes.

Aedes↗

Functional role of intrahypothalamic release of oxytocin and vasopressin: consequences and controversies.

This brief review of vasopressin (VP) and oxytocin (OT) release into the extracellular space of the supraoptic (SON) and paraventricular (PVN) nuclei focuses on recent data illustrating the significance of their intranuclear release and the potential functional consequences. With the use of in vitro techniques, it has been demonstrated that administration of exogenous OT causes local peptide release and that, in vivo, this facilitates the milk ejection reflex. These findings lead to the idea that endogenous peptides are released into the hypothalamic nuclei. Microperfusion techniques have been used to monitor the dynamics of intranuclear OT and VP release in response to distinct stimuli. It is clear that intranuclear release of OT plays a role during reproductive states (parturition and lactation) and that intranuclear release of VP and OT is involved in osmoregulation. This review discusses 1) the origin of the intranuclearly released peptides, 2) stimuli which cause release into the hypothalamic nuclei, and 3) the function of intranuclear VP and OT, e.g., regulation of local morphology, feedback mechanisms and synchronization, and the possible role in regulating autonomic function and behavior.

Animals↗

Effects of tetrodotoxin on osmotically stimulated central and peripheral vasopressin and oxytocin release.

Tetrodotoxin (TTX) was used to (1) distinguish between axonal and dendritic/somatic release of vasopressin (VP) and oxytocin (OT) within the supraoptic nucleus (SON) and (2) to determine whether neuronal inputs trigger intranuclear peptide release in the response to osmotic stimulation. Microdialysis was used to administer TTX (10(-6) M or 10(-4)M) bilaterally into the SON with simultaneous monitoring of central and peripheral peptide release and mean arterial pressure in urethane-anesthetized male rats. Osmotic stimuli were given via the microdialysis probe (1 M NaCl-artificial CSF) or injected intraperitoneally (3.5 M NaCl; 600 mu l/100 g b.w.) SON perfusion with TTX did not alter basal intranuclear VP or OT release or the intranuclear peptide response to direct NaCl stimulation of the SON. However, TTX treatment abolished the effect of peripheral osmotic stimulation on central peptide release. Basal plasma peptide levels were significantly reduced by TTX, e.g. decreases of 94.8 and 75.8% for VP and OT, respectively. TTX also blocked the peripheral endocrine and cardiovascular responses to both modes of osmotic stimulation. The TTX insensitivity of directly stimulated intranuclear release suggests nonsynaptic peptide release from dendrites and/or cell bodies. The ability of TTX to abolish the central peptide response to systemic osmotic stimulation demonstrates that intranuclear release is a part of a cascade produced by osmotic activation of multisynaptic pathways.

Animals↗

Increased maximal pulmonary response to methacholine and airway smooth muscle in immature compared with mature rabbits.

We compared the effect of maturation upon the maximal pulmonary response to inhaled methacholine in rabbits and also assessed whether there was an age-related difference in the quantity of airway smooth muscle. In sedated, paralyzed, and mechanically ventilated rabbits, pulmonary resistance was measured following increasing doses of aerosolized methacholine (0.5 to 256 mg/ml). The six mature rabbits (6 mo) demonstrated a plateau in their dose-response curves whereas only three of six immature animals (1 mo) had a plateau. The immature compared with the mature animals had a greater maximal increase in pulmonary resistance (950% versus 380%). The lungs were examined by light microscopy to determine morphometrically the area of smooth muscle (ASM) in the airway walls. ASM was normalized for airway size by dividing by the ideal airway area. The normalized ASM was different for the two age groups and the immature animals' airways had more smooth muscle. The relationship between airway size and ASM was similar for the two age groups with smaller airways having proportionately more smooth muscle. The differences with age in ASM area were primarily due to the immature animals having a greater number of airways of small size. There was not a significant relationship between the maximal percent increase in pulmonary resistance and the normalized ASM. We conclude that inhaled methacholine produces a greater maximal increase in the pulmonary resistance of immature than mature rabbits and that this difference is unlikely to be caused by a proportionately greater quantity of ASM in the immature than the mature rabbit airways.

Aging↗

[Prostatitis].

During the last years, diagnosis and therapy of prostatitis have advanced rapidly. A detailed standardized diagnostic procedure is mandatory to delimit inflammatory from noninflammatory variations of the prostatitis syndrome. Whereas Gram-negative pathogens are agreed to be etiologically responsible, the relevance of chlamydia and mycoplasma is still under debate. Further diagnostic work-up should comprise ejaculate analysis, screening of the bladder voiding and transrectal prostatic sonography. The therapy of the inflammatory prostatitis is aimed to the demonstration of relevant pathogens, antibiotic treatment must be suited to expected sensitivity of the pathogen. Surgical procedures may be discussed when antibiotic treatment has failed. If it is not possible to identify relevant pathogens, the therapy remains of experimental character. Prostatodynia as noninflammatory disease often requires psychodynamic exploration.

Anti-Bacterial Agents↗

Dependence of CO2-baited suction trap captures on temperature variations.

In order to provide better standardized CO2-baited trap samples, the relationship between sample size and evening temperatures was studied. Adult mosquitoes were collected for 3 h centered on sunset by an automatic interval suction trap baited with CO2 in the Upper Rhine Valley, Germany. Aedes vexans females were most abundant, and their blood-seeking activity showed a significant correlation with the evening's average temperature (r = 0.76, P < or = 0.05). A higher degree of correlation was obtained when the number of specimens caught was related to temperature indices (r = 0.93-0.98, P < or = 0.01). A regression equation indicates the lower temperature threshold for Aedes vexans was between 9 and 10 degrees C. For each degree of increase in the average temperature index, it was estimated that a 5.5% greater number of mosquitoes would be trapped. An upper temperature threshold for this species was not observed at average temperatures < or = 23 degrees C. A relationship between catches of Aedes rossicus and Aedes cinereus and temperatures recorded at the site during the study was not found.

Aedes↗

Role of larval cadavers in recycling processes of Bacillus sphaericus.

The influence of larval cadavers of Culex pipiens on recycling processes of Bacillus sphaericus was investigated by bioassays and spore counts in the laboratory. Studies conducted with 3 different B. sphaericus concentrations (0.005, 0.01, 0.05 mg B. sphaericus/liter) indicated that the presence of cadavers in the water contributed to the maintenance of toxic levels of B. sphaericus. Larval cadavers seem to contain all the nutrients necessary both for vegetative multiplication and for toxin synthesis associated with the sporulation process. Bioassays of B. sphaericus revealed that the mortality of Culex pipiens remained on a high level over a period of 26 days when larval cadavers were added every second day to the test vessels. This result was supported by a sharp increase in spore density when cadavers were added at the same interval. The test series showed B. sphaericus recycles in intact cadavers of Culex pipiens, whereas this phenomenon could not be observed when crushed cadavers were used in the trials. Therefore, our results demonstrated that for successful recycling processes it seems of crucial importance that infected cadavers remain intact at least for a certain time and also that the dosage of the applied B. sphaericus plays a major role in recycling processes whereas larval density is only of minor importance to these processes.

Animals↗

The nucleotide sequence of a complementary DNA encoding Flaveria bidentis carbonic anhydrase.

We have isolated and characterised a cDNA clone encoding the cytosolic form of carbonic anhydrase in the leaves of Flaveria bidentis, a C4 dicotyledonous plant. The deduced amino acid sequence is similar to the carbonic anhydrase found in the chloroplasts of C3 dicotyledonous plants. Western blot analysis of crude leaf extracts of F. bidentis indicates that the leader sequence (equivalent to the transit peptide of the chloroplastic form of CA found in C3 plants) is not removed following translation of mRNA.

Amino Acid Sequence↗

Vasopressin facilitates its own release within the rat supraoptic nucleus in vivo.

A combined microdialysis/microinfusion technique was used to investigate whether arginine vasopressin (AVP) is involved in the regulation of its own release into the extracellular fluid of the supraoptic nucleus in vivo. While intranuclear neuropeptide release was monitored, 0.33 microliter of either vehicle, lysine vasopressin (LVP; 10 ng microliters -1) or a V1/V2 AVP receptor antagonist (100 ng microliters -1) was infused into the supraoptic nucleus of adult male Wistar rats before and during direct osmotic stimulation of the nucleus via the microdialysis probe. Administration of LVP increased basal AVP release, whereas administration of the V1/V2 receptor antagonist attenuated the increase in AVP release during osmotic stimulation observed in vehicle-treated controls. Taken together, these results indicate a receptor-mediated positive feedback action of endogenous AVP on its own release within the supraoptic nucleus.

Animals↗

Evidence for cardiovascular remodeling in a patient with Bartter's syndrome.

In a 56-year-old normotensive white male subject with a 12-year history of hypokalemic alkalosis, hyperreninemia, and aldosteronism, the diagnosis of Bartter's syndrome was established on the basis of an impaired maximal renal diluting capacity and decreased distal fractional chloride absorption [CH2O/(CH2O+CCl)]. Negative urine analysis for diuretics suggested that this renal tubular defect was not secondary to diuretic (ab)use. In this normotensive patient with hyperreninemia and secondary aldosteronism, significant cardiovascular remodeling could be observed. Thus, in spite of normal arterial blood pressure and normal left ventricular systolic function (ejection fraction > 70%), impaired left ventricular diastolic function was observed using pulsed-wave Doppler echocardiography. Moreover, duplex analysis of the common carotid artery revealed significant intima-media hypertrophy with an average intima-media diameter of 0.9 mm (normal < or = 0.6 mm). Also, forearm venous occlusion plethysmography revealed an abnormally high minimal forearm vascular resistance following a 10-min period of forearm ischemia handgrip exercise suggesting remodeling within the peripheral arterioles. Thus, in a patient with Bartter's syndrome and activated neurohormonal systems such as the renin-angiotensin system, cardiac and vascular remodeling can be observed in the absence of hypertension. In analogy to the results of experimental studies showing that angiotensin II and noradrenaline act as growth factors on cardiac and vascular cells, cardiovascular remodeling present in our patient with Bartter's syndrome may be explained by increased activity of angiotensin II and/or noradrenaline.

Arteries↗