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PubMed1997

[MR angiography of thoracic blood vessels].

Through the introduction of newly invented high-performance gradient systems to MRI, which enable for echoplanar imaging (EPI), also magnetic resonance angiography (MRA) has gained an entirely new field of applications and techniques. Ultrafast imaging techniques in MRA allow the investigation of larger vascular areas within a single breath-hold-period. Artifacts like motion induced signal misregistrations, dephasing or saturation of the vascular signal are minimized by extremely short echo times. The technique thus requires the intravenous application of a contrast media bolus, usually a gadolinium compound, which is in standard clinical use. Coordination of the bolus injection and the timing of the data acquisition is crucial for optimal results. The first pass evaluation of the contrast media resembles CTA to a certain extend. Due to the fast measurement and the high contrast in contrast-enhanced MRA (CE-MRA) new applications and indications are developed like MRA of the pulmonary vessels. The paper offers considerations and trials for optimization of thoracical CE-MRA. Besides parameter constellation also bolus-optimization is described with respect to the dedicated anatomical premises. Investigations on volunteers and on patients build a basis for suggestions of optimized CE-MRA procedures. To date, a final estimation of the clinical value of the new technique cannot be given since ongoing improvements change the optimal protocol frequently and the potential of further developments is high.

Adolescent↗
PubMed2006

[Maximilian Nitze (1848-1906): Obstetrician to urology].

Maximilian Carl Friedrich Nitze was born on the 18th of September 1848 in Berlin. In 1874 he passed his state examination in Leipzig for a doctorate in medicine. Nitze demonstrated the first urethroscope and cystoscope, which he had built with great effort and under considerable hardship, at the Dresden-Friedrichstadt Institute using a cadaver--this was the hour of birth of modern urology. Nitze's invention of the cystoscope and his achievements as a urologist have made urology into an independent specialist branch of medicine. This led, after his early death, to the establishment of the German Society for Urology and the Zeitschrift für Urologie in 1906, as well as the organization of the first urological congress in Vienna in 1907.

Cystoscopes↗
PubMed2004

The rebirth of PTSD: the rise of a new paradigm in psychiatry.

The new conception of psychological trauma that arose in the 1980s with the definition of PTSD in the DSM-III was a major change compared to the previous traumatic neurosis. While the clinical features were in some way similar, the political and sociological meanings of trauma were absolutely different. At that time, the invention of PTSD was much more the consequence of a broad mutation in mentality that introduced a new moral perspective in trauma studies than of a scientific discovery. In this paper, the author underlines from an anthropological point of view the second turning point that occurred in trauma studies in the mid 1990s when large epidemiological surveys did not confirm the first hypothesis. Readdressing the issues of vulnerability and risk factors that the previous version of PTSD had withdrawn, this second conception raises new epistemological questions that stay unsolved.

Diagnostic and Statistical Manual of Mental Disord↗
PubMed1999

[Diagnostic imaging of hemophilic osteoarthropathy].

Presently, the degree of the hemophilic arthropathy is estimated by the classification system of Pettersson, which is recommended by the Orthopedic Advisory Committee of the World Federation of Hemophilia. This classification system bases upon plain radiographs of the joints and analyses only those changes which represent the progression of the arthropathy. The value of this classification system has been established by inter-observer studies. However, it shows drawbacks at the exact definition of some parameters. Presently, it is more valuable for longitudinal than for transversal studies. Due to the possibilities of an adequate substitution therapy, only minor degrees of an arthropathy are observed in children. The ankle joints are more severly affected than the elbow joints and they more than the knee joints. This distribution is explained by an increasing sports activity in children. If more than 3 joint bleedings occur within a year the invent of an arthropathy must be presumed. Because the classification system of Pettersson analyses only osseous changes representing late changes, important early changes like hypertrophy of the synovialis and focal destruction of the joint cartilage are overlooked. Magnetic resonance imaging is suitable to show these early changes reliably. MRI can be recommended for the investigation of recurrently bleeding joints without evidence of major osseous changes and for decision making to perform a synovectomy.

Arthrography↗
PubMed1998

Heart transplantation without informed consent: discussion of a case.

OBJECTIVE: To discuss informed consent to heart transplantation in the case of an intensive care unit (ICU) patient: relatives' informed consent was refused by the patient himself whose cognitive ability appeared to be reasonable for the purpose. SETTING: ICU of a university teaching hospital. PATIENT: A 62-year-old man who underwent myocardial revascularization had in the immediate post-operative hemodynamic instability, continuous serious arrhythmias, ventilatory support, fentanyl infusion. Heart transplantation could be the only chance for his survival. INVENTION: Heart transplantation. RESULTS: Despite patient's refusal, we decided to hold the relative's consent as valid, and transplantation was accordingly performed, to the subsequent satisfaction of the patient. CONCLUSIONS: Our decision was based on two beliefs: (1) the severity of the patient's clinical condition may have impaired his cognitive abilities; (2) the very same conditions may mask impairment and certainly make reliable assessment of cognition and judgment impossible. This being so, the preservation of life assumes priority.

Cardiac Output, Low↗
PubMed2003

Secretins of Pseudomonas aeruginosa: large holes in the outer membrane.

Pseudomonas aeruginosa produces a large number of exoproteins, ranging from the ADP-ribosyltransferases exotoxin A and ExoS to degradative enzymes, such as elastase and chitinase. As it is a gram-negative bacterium, P. aeruginosa must be able to transport these exoproteins across both membranes of the cell envelope. In addition, also proteins that are part of cellular appendages, such as type IV pili and flagella, have to cross the cell envelope. Whereas the majority of the proteins transported across the inner membrane are dependent on the Sec channel, the systems for translocation across the outer membrane seem to be more diverse. Gram-negative bacteria have invented a number of different strategies during the course of evolution to achieve this goal. Although these transport machineries seem to be radically different, many of them actually depend on a member of the secretin protein family for their function. Recent results show that secretins form a large complex in the outer membrane, which constitutes the actual translocation channel. Understanding the working mechanism of this protein translocation channel could open up new strategies to target molecular machineries at the heart of many important virulence factors.

Bacterial Outer Membrane Proteins↗
PubMed2000

Analytical chemistry and the law: progress for half a millennium.

Chemistry has been used for the detection of adulteration since the earliest times of recorded history going back at least 3 1/2 millennia. Since the invention of printing the subject is easier to follow. Aspects of law and its application via chemistry in regard to precious metals, food, drink and medicinal materials are reviewed over the last half millennium with particular reference to the U.K.

Chemistry, Analytic↗
PubMed1998

An algorithm for correction of distortion in stereotaxic digital subtraction angiography.

An algorithm for correction of the geometrical distortion in digital subtraction angiography (DSA) images was developed. Originally invented for 3D X-ray angiography, the algorithm was implemented in a computer program designed to fulfil the specific needs of stereotaxic DSA. The algorithm is based on transformation of an image of a grid from a distorted image back into its original pattern. The same transformation is then applied pixel-by-pixel to the angiographic images, which are acquired in direct conjunction with the grid image, without moving the gantry. The algorithm was tested in phantom studies and in the clinical situation with seven patients in ten examinations. Comparisons were made between co-ordinate determinations made on conventional full-size cut film and those performed on uncorrected and corrected DSA images, using 30- and 23-cm fields of view. With our method of measurement we could not shown any remaining geometric distortion in the corrected DSA images. This distortion correction can, if properly applied, be used for high-precision stereotaxic DSA.

Algorithms↗
PubMed2005

Primate-specific endogenous cis-antisense transcription in the human 5q31 protocadherin gene cluster.

Protocadherins (PCDH), localized to synaptic junctions, contribute to the formation of neuronal networks during brain development; thus, it is speculated that protocadherins may play a role in evolution of neuronal complexity. While protocadherin genes are highly conserved in vertebrates, EST evidence from the locus suggests apparently species-specific cis-antisense transcripts. Novel cis-antisense transcripts, which partially overlap the PCDHalpha12 variable exon, PCDHbeta3 single-exon gene, and PCDHpsi5 unprocessed pseudogene in the human 5q31 PCDHalpha/beta/gamma gene cluster and which are coexpressed with sense-strand transcripts in fetal and adult brain, were identified computationally and validated by gene-specific strand-specific reverse transcriptase PCR (SSRTPCR) and sequencing. Absence of antisense transcripts arising from equivalent genomic locations in mouse indicates that the antisense transcripts originated in the primates after the primate-rodent divergence. Furthermore, not all expected orthologues of human sense and antisense PCDH transcripts were detected in rhesus macaque brain, implying that protocadherin expression patterns differ between primate species. RT followed by quantitative real-time PCR (QPCR) analysis of the three genes in the brain of all three species, and of the PCDHbeta15 gene paralogous to PCDHpsi5 in human and rhesus, revealed that the presence of antisense transcripts was significantly associated with lower sense expression levels across all orthologues. This inverse relationship, along with the pattern of sense and antisense coexpression in the brain, is consistent with a regulatory role for the primate-specific PCDH cis-antisense transcripts, which may represent recent evolutionary inventions modulating the activity of this conserved gene cluster.

Animals↗
PubMed2004

Liver tumors: evaluation with contrast-enhanced ultrasound.

The development and clinical introduction of microbubble contrast agents has had a particular impact on the detection and differential diagnosis of liver tumors. The first approach widely employed made use of high-transmission power ultrasound, which destroyed the microbubbles in the process of imaging them. It is particularly successful for those agents that have a liver-specific post-vascular phase because, like liver-specific agents used in other imaging modalities such as magnetic resonance imaging and nuclear medicine, malignancies do not retain the contrast, so they stand out with very high conspicuity. Used this way with color Doppler or variants of it, more subcentimeter lesions can be demonstrated with ultrasound than with computed tomography. However, the destructive nature of this approach meant that continuous real-time scanning was impossible. Two developments allowed this to be redressed: new classes of microbubbles with perfluoro gasses instead of air and the invention of multipulse scanning modes that are sensitive to the nonlinear (harmonic) responses of the microbubbles and suppresses tissue signals. This low-power approach is now used almost exclusively, and it has the advantage of displaying the arterial phase of blood supply to a mass and a later phase when the bubbles are trapped in the sinusoids so that the vascular volume of the tissue is depicted. Malignancies typically show a low signal intensity in this phase, regardless of whether they are hyper- or hypovascular in terms of their arterial supply. This allows them to be detected with high sensitivity and much more easily than the destructive modes allowed. In addition, the arterial supply that can be now depicted in real time has characteristics that allow most benign masses to be distinguished from each other and from malignancies, thus improving specificity. Microbubbles also can be used as tracers to provide functional information that can detect occult metastases and cirrhosis noninvasively.

Acoustics↗
PubMed2003

Review of the " Chirurgia" of Giovanni de Vigo: estimate of his position in the history of surgery.

Giovanni de Vigo, who was born in at Rapallo, Italy, lived in the early Renaissance period (1450-1525). In 1503, De Vigo became the personal surgeon to Pope Julius II. He wrote a surgical book, " Practica Copiosa in Arte Chirurgia," which was completed in 1514 and published in Latin. It was translated into English by Richard Traheron and printed by Edward Whytchurch in 1543. Vigo's " Chirurgia" consists of nine books ranging from a consideration of anatomy necessary for a surgeon, to sections on abscesses, wounds, ulcers, benign and malignant tumors, fractures and dislocations, pharmaceuticals, ointments and plasters, as well as sections on dentistry, exercise, diet, syphilis, among others. De Vigo introduces a novel approach for treating mandible dislocations and describes a trephine he invented, as well as a number of new instruments. Examination of his surgical piece demonstrates that he had a broad spectrum of knowledge in surgery based in part on the ancient Greek and Arabic medical literature but mainly on his personal experience. Giovanni de Vigo contributed significantly to the revival of medicine in the sixteenth century, and he can be considered as a bridge between Greek medicine of antiquity, Arabic medicine, and the Renaissance.

General Surgery↗
PubMed2005

The common sense of the self-nonself discrimination.

The vertebrate immune system was evolutionarily selected to express a large random somatically generated paratopic repertoire coupled to effector mechanisms invented, in large measure, by non-vertebrates. The self-nonself discrimination is determined by Decision 1, the sorting of this repertoire into those specificities (anti-self) which, if expressed, would debilitate the host and those specificities (anti-nonself) which, if not expressed, would result in the death of the host by infection. Decision 1, the sorting of the repertoire, is mediated by a somatic learning process operating epitope-by-epitope that deletes anti-self specificities leaving the residue as anti-nonself. The activation of anti-nonself is the first step on entry into Decision 2, which optimizes the choice and magnitude of the effector class that rids the pathogen without significantly debilitating the host. The principles governing Decision 1, the self-nonself discrimination are analyzed here.

Animals↗
PubMed2004

Julius Bruck (1840-1902) and his influence on the endoscopy of today.

A hundred years ago, on 20 April 1902, Breslaus most famous dentist of the time died. Julius Bruck was not only the most famous dentist and fighter for dentists' education in Germany in his time, but also one of the most successful inventors. In 1866, he produced light by using an exposed electrically heated platinum loop, which at that time was the most powerful light source known. He conceived of the possibility of placing the source of light in the distal end of an instrument and invented a double glass tube with a water-cooling compartment. This water cooled apparatus (diaphanoscope) was inserted into the rectum or vagina, to transilluminate the bladder. The key to further advances was born with the introduction of an internal electric light source. In 1877, the potential of Bruck's theoretical advance was realised in combination with other advances which virtually established the form of the clinically useful cystoscope as it is used today. The remarkable man responsible for this synthesis was Maximilian Nitze.

Cystoscopy↗
PubMed2006

The role of biofilm infection in urology.

In the process of endourological development a great variety of foreign bodies have been invented besides urinary catheters on which biofilm can be formed. Bacteria in the biofilm are less sensible to antibiotics. An additional problem of medical biomaterials in the urinary tract environment is the development of encrustation and consecutive obstruction. In this review, we tried to sum up the conditions where biofilm formation has a great impact on the development or maintenance of urological infections and on treatment success. Modification of the biomaterial surface seems to be the most promising prevention strategy for bacterial biofilms. Easier methods for diagnosing and quantifying biofilm infection, to develop more specific antimicrobial agents and ideal device surfaces would surely help the fight against biofilm formation.

Anti-Bacterial Agents↗
PubMed1999

The development of urological endoscopy in America.

This article deals with the history of medicine in American urology, where endoscopy is a very important subject. The development of endoscopy in America unrolled in three phases: the acquisition of European techniques and instruments, realization of the ideas of American researchers, and original creations that forwarded endoscopy considerably. European instruments were acquired in the nineteenth century, culminating in the instruments developed by Max Nitze. When Wappler started the production of endoscopes in 1905, they were the basis for the development of numerous modifications and innovations such as electrosurgery, developed by Beer in 1910, with the Resonator created by Wappler; the resectoscope, invented by Stern and McCarthy in 1931; "cold light" using glass fibers for illumination, described by ACMI in 1960; the flexible fiber ureterorenoscope, described by Marshall in 1960; and fluorescence cystoscopy, introduced by I. M. Bush and W. F. Whitmore in 1964.

Diagnostic Techniques, Urological↗
PubMed2000

CSF shunts 50 years on--past, present and future.

Cerebrospinal fluid (CSF) shunts were invented almost 50 years ago. While their introduction revolutionized the treatment of hydrocephalus, their complications have become legendary, and the focus of much investigation and development of new devices. New devices have been based upon improved understanding of the pathophysiology of hydrocephalus or shunt complications. Despite the rational, or frequently "more physiological," functioning of these devices, all too often unexpected complications have ensued, and the initial enthusiasm for the devices has waned. Assessing the efficacy of the devices has been difficult, owing to the lack of properly conducted studies. Nevertheless, the overall impact of shunt design improvements has seemed very limited. A recent randomized trial of CSF shunt design, examining the failure rates of two new and widely used valves (the Cordis Orbis Sigma and the Medtronic PS Medical Delta valves) failed to find any advantage of these over standard valve designs, many of which have been used almost since the inception of CSF shunts. A search for risk factors for failure, in a post hoc analysis of the data, indicated only that the etiology of the hydrocephalus and the position and local environment of the ventricular catheter tip were probably important. Remarkably, the rate of change in the size of the ventricles and the final ventricular size were not different despite the substantial differences in flow characteristics of the two new valves. Shunt failure rates of less than 5% at 1 year, with infection rates of less than 1%, seem like reasonable goals for the next decade in the new millenium. This can be achieved through basic research into the pathophysiology of shunt failure with improved mathematical models, and perhaps animal models of shunt failure. Efficacy of new devices or treatments must be scrutinized scientifically so as not to waste valuable resources and time on unproven treatments. Uncontrolled series and testimonial assertions about new treatments or devices, especially from proponents with a vested interest, should be regarded with great skepticism. Nevertheless, our best efforts are likely to result in a major advance in the management of pediatric hydrocephalus, which now seems tantalizingly close.

Animals↗
PubMed2004

Therapy of periprosthetical leakage with tissue augmentation using Bioplastique around the implanted voice prosthesis.

Having a voice prosthesis provides a good possibility for speech rehabilitation after total laryngectomy has been performed, especially if common complications such as leakage around the valve can be reduced effectively. The early applications of a voice prosthesis-which was originally invented and applied by Mozolewski in 1972, was further developed by Blom and Singer and became an internationally available implantable instrument by 1980- already made clear not only the typical benefits, but also the complications, such as possible leakage around the implanted valve. Remacle proposed the injection of collagen into the surrounding tissues in order to stop leakage. Knowing that collagen is usually resorbed as time goes by, new substances that can be tolerated by human tissues must be found. This article reports the experiences of the authors in the search for such an injectable material that cannot be resorbed and does not migrate. In order to solve the above-mentioned problem, Lichtenberger introduced the injection of Bioplastique into the perivalvular tissues. This delivered the best results ever achieved in this field at our department. During the past 2 years, Bioplastique augmentation was performed for seven laryngectomized and speech-rehabilitated patients in order to reduce periprosthetical leakage. All procedures were successful in terms of either eliminating or reducing the leakage, and also the non-resorbable property of Bioplastique has been proven.

Adult↗
PubMed1999

Munchausen syndrome by proxy and intra-alveolar haemosiderin.

Munchausen syndrome by proxy is characterised by the invention of a false history and/or the deliberate inducement of a factitious illness by parents in their child. First reported as a disorder of mothers, this syndrome is now recognised to have male perpetrators. One of the most common characteristic presentations is with the child allegedly suffering repeated apnoeic attacks. These are in fact deliberately induced episodes of upper airway obstruction. The children of these parents are at great risk of serious harm or death if not recognised. The identification of smothering at autopsy is fraught with difficulty and the presence of intra-alveolar haemosiderin has been claimed to be a marker of previous smothering. A case of Munchausen syndrome by proxy is presented where there were deliberate acts of repeated partial smothering and where the finding of intra-alveolar haemosiderin at autopsy provided additional supportive evidence of smothering.

Airway Obstruction↗