bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of the Urine Concentration Mechanism by the Oropharyngeal Afferent Pathway in Man
Authors: Kuramochi Gen , Kobayashi Isao
Published: April 2003

Background: It has been reported that the oropharyngeal afferent pathway behaves as a first-order factor regulating body fluid. However, the neural mechanism has not yet been clear. This study was designed to elucidate the characteristics of the neural mechanism in man. Methods: Healthy human subjects kept either an isotonic or hypertonic solution in the oral cavity so as to moisten the oropharyngeal mucosa without intake for 20 min. Plasma vasopressin (AVP) concentration, urine volume and urine and plasma osmolalities were measured before and after the application. Results: The oropharyngeal application of isotonic saline induced no significant changes in plasma AVP concentration, urine volume and osmolality, while that of hypertonic saline induced a significant decrease and increase in urine volume and osmolality, respectively. The plasma AVP concentration increased significantly after the application of hypertonic saline. Mannitol also induced a significant decrease and increase in urine volume and osmolality, respectively. However, the urinary responses after the application of mannitol were delayed compared with those of hypertonic saline. There were no significant changes in plasma osmolality before and after each application. Conclusion: These results suggest that the oropharyngeal afferent pathway from the oropharynx to hypothalamic AVP-producing cells takes part in the thirst mechanism regulating body fluid in humans. The oropharyngeal afferent signals may behave as sodium-chloride-sensitive osmoreceptor.
Cystatin C: Efficacy as Screening Test for Reduced Glomerular Filtration Rate
Authors: Herget-Rosenthal Stefan , Trabold Silke , Pietruck Frank , Holtmann Marianne , Philipp Thomas , Kribben Andreas
Published: April 2003

Serum cystatin C, a cysteine proteinase inhibitor, has been proposed as a marker of glomerular filtration rate (GFR). Serum cystatin C, serum creatinine and creatinine clearance were measured in 226 patients with various nephropathies, covering the entire range of renal function, to evaluate the efficacy of cystatin C as a screening test to detect reduced creatinine clearance in comparison to creatinine. Subgroups of 53 patients with glomerular and 26 patients with tubular impairment were compared to assess whether cystatin C performed differently in either glomerular or tubular impairment. Cystatin C detected reduced creatinine clearance with higher sensitivity (97 vs. 83%), and higher negative predictive value (96 vs. 87%) compared to creatinine. In parallel, 95% sensitivity of cystatin C as derived from receiver-operating characteristic plot was significantly higher (p < 0.05). In the subgroups with glomerular or tubular impairment, cystatin C and creatinine did not significantly differ with regard to efficacy. Serum cystatin C is as efficacious as serum creatinine to detect reduced GFR as measured by creatinine clearance. The efficacy of cystatin C as a screening test may even be superior compared to creatinine. In addition, the efficacy of cystatin C is independent of either glomerular or tubular impairment.
The Evaluation of Corticosteroid Therapy in Conjunction with Plasma Exchange in the Treatment of Renal Cholesterol Embolic Disease
Authors: Hasegawa Midori , Kawashima Shirou , Shikano Masahiko , Hasegawa Hiroshi , Tomita Makoto , Murakami Kazutaka , Kushimoto Hiroko , Katsumata Hideki , Toba Takako , Oohashi Atsushi , Hiramitsu Shinya , Matsunaga Kayoko
Published: April 2003

In this report, we describe 5 patients with cholesterol atheroembolic renal failure. In 3 of the 5 patients, combined therapy with corticosteroids and plasma exchange was performed. These 3 patients survived, with 2 showing an improvement in renal function. The 2 remaining patients died of multifactorial causes. The literature on therapy for cholesterol atheroembolic renal failure is reviewed and the efficacy of combined therapy by use of corticosteroids and plasma exchange is evaluated.
Analysis of Patients Dying within One Year of Starting Renal Replacement Therapy
Authors: Walters Giles , Warwick Graham , Walls John
Published: April 2003

Background: The annual gross mortality of end-stage renal failure patients remains very high (approximately 15-20%) leading some to question the wisdom of accepting patients with limited prognosis for dialysis. We have reviewed the demographic and clinical characteristics of patients who died within a year of commencing renal replacement therapy (RRT) over a 5-year period to establish whether these patients could be identified at the start of therapy. Methods: Case notes of patients who died within 1 year of commencing RRT between 1st April, 1991 and 31st March, 1996 were reviewed. Comorbidity at the start of dialysis was used to classify patients into high-, medium- and low-risk groups using two published scales to determine whether either graded a high proportion of deaths as high risk. Factors such as age, social circumstances, cause of death, renal diagnosis and mode of dialysis were also analysed. Results: 17.5% of patients commencing RRT died in the first year. Not all of these patients could be identified as high risk by comorbidity assessment at dialysis initiation - 50% of patients who died were classified by one scale as medium risk. Age did not clearly predict outcome, as 42% of patients who died were less than 65 years old. Conclusion: These data suggest that it is difficult to use current risk stratifications to accurately predict outcome on RRT.
Effects of Angiotensin-Converting Enzyme Inhibitor, Angiotensin II Receptor Antagonist and Calcium Antagonist on Urinary Podocytes in Patients with IgA Nephropathy
Authors: Nakamura Tsukasa , Ushiyama Chifuyu , Suzuki Shingo , Hara Masanori , Shimada Noriaki , Sekizuka Keiko , Ebihara Isao , Koide Hikaru
Published: April 2003

The urinary podocyte is postulated to be a marker for estimation of the severity of active glomerular injury and a predictor of disease progression in children with glomerulonephritis. Non-dihydropyridine calcium antagonist, including verapamil, reduce proteinuria to an extent similar to that of the angiotensin-converting enzyme inhibitor (ACEI), including trandolapril, but to a greater extent than other antihypertensives. Angiotensin (Ang) II receptor antagonists, including candesartan cilexetil, show potent and long-term preventive effects against the progression of renal injury. The aim of the present study is to assess whether verapamil, trandolapril and candesartan cilexetil affect proteinuria and urinary podocytes in patients with IgA nephropathy. Thirty-two normotensive patients aged 18-54 years with biopsy-proven IgA nephropathy, nonnephrotic proteinuria (1-3 g/day), and normal renal function (creatinine clearance >80 ml/min) were studied. Twenty patients with diffuse mesangial proliferative glomerulonephritis (non-IgA PGN) and 20 healthy controls were also included in this study. The number of urinary podocytes in patients with advanced IgA nephropathy (n = 16) was significantly higher than that in patients with the disease in the mild stage (n = 16) (p < 0.01) or in patients with non-IgA PGN (p < 0.01). Urinary podocytes were not detected in healthy controls. The 32 patients with IgA nephropathy were randomly divided into four treatment groups: those treated with verapamil (120 mg/day, n = 8); those treated with trandolapril (2 mg/day, n = 8); those treated with candesartan cilexetil (8 mg/day, n = 8), and those given a placebo (n = 8). Treatment continued for 3 months. Antiproteinuric response in the trandolapril group was similar to that in the candesartan cilexetil group (-38 vs. -40%). The action of trandolapril or candesartan cilexetil was greater than that of verapamil (p < 0.01). Reduction in the number of urinary podocytes from baseline was significantly greater in patients treated with trandolapril or candesartan cilexetil than in patients treated with verapamil (p < 0.01). However, there was no difference between patients treated with trandolapril and those treated with candesartan cilexetil. Proteinuria and urinary podocytes were unaffected in the placebo group. These data suggest that urinary podocytes may be a marker of disease activity in adult patients with IgA nephropathy and that trandolapril and candesartan cilexetil are more effective than verapamil in reducing the number of podocytes.
Hemolytic and Uremic Syndrome after Heart Transplantation
Authors: Mercadal L. , Petitclerc T. , Assogba U. , Beaufils H. , Deray G.
Published: April 2003

Two cases of hemolytic and uremic syndrome in heart transplant recipients are reported. Among solid organ transplantations, this complication mainly occurred in renal transplantation and only 1 case was reported in heart transplantation in the literature. Cyclosporine was the only etiologic factor found. The renal outcome was severe with end-stage renal failure and no recovery of the renal function despite stopping cyclosporine, corticoids and plasma exchange.
Borderline-Persönlichkeitsstörungen als Ausdruck des inneren Ringens um Einheitlichkeit von Bewusstsein
Authors: Emrich H.M.
Published: April 2003

Leider
besteht für diesen Artikel keine Zusammenfassung. Als Einstieg stellen wir den
Textanfang zur Verfügung. Eine begriffliche Präzisierung des Grenzgängertums, das im Terminus «Borderline-Persönlichkeitsstörungen» enthalten ist, muss die Geschichte dieses Begriffs mit einschliessen. Vor etwa 25 Jahren, in seiner ersten Version, war der Begriff der «Borderline-Erkrankungen» innigst verbunden mit der Rezeption des damaligen psychotherapeutischen Bestsellers von Hannah Green [1988]: «I Have Never Promised You a Rose Garden» – «Ich habe Dir nie einen Rosengarten versprochen». Das Grenzgängertum, um das es hier ging, war die schwierige Grenzziehung zwischen neurotischem und psychotischem Leben und Erleben, Verhalten und psychischem Leiden von Menschen, deren Störung nosologisch schwer einzuordnen erschien.
Individuation und gesellschaftliche Realität
Authors: Odermatt Martin
Published: April 2003

Leider besteht für diesen Artikel keine Zusammenfassung. Als Einstieg stellen wir den Textanfang zur Verfügung.Werde, der du bist; werde, der du sein kannst; werde, der du sein sollst. So und ähnlich ist durch Jahrtausende das Selbstverständnis des Menschen umschrieben worden. Mit solchen Formulierungen ist im wesentlichen auch ausgedrückt, was Carl Gustav Jung mit Individuation meint. Es geht um die Entfaltung dessen, was als Potential in der Seele eines Menschen angelegt ist; es geht um die Bewusstwerdung seiner selbst als einmaliges Individuum und um die Entwicklung seiner selbst auf das in der Seele mitverankerte Ziel hin. Und dieses Ziel heisst Sinnfindung in der grösstmöglichen Annäherung an die Ganzheit menschlicher Existenz. Individuation im Sinne Carl Gustav Jungs ist Ganzwerdung als kontinuierliche und wachsende Bezogenheit des bewussten Ich auf das je grössere Unbewusste. Individuation ereignet sich in der Schwingung der Seele zwischen den gegensätzlichen Polen der Wirklichkeit, als da sind: Geist und Instinkt, Innen und Aussen, Individualität und Kollektiv.
Ist die Analytische Psychologie C.G. Jungs ein Auslaufmodell?
Authors: Lier Doris
Published: April 2003

Leider besteht für diesen Artikel keine Zusammenfassung. Als Einstieg stellen wir den Textanfang zur Verfügung.Die im Titel gestellte Frage wurde mir kürzlich von einem Theologen als Tatsache präsentiert. «Die Jungsche Psychologie ist ein Auslaufmodell», war seine Aussage, ganz offensichtlich im Sinn von «überholt» und damit «nichts mehr wert». Die Antwort auf meine Frage, wie er zu diesem Schluss komme, war enttäuschend banal. Es fehle der Jungschen Psychologie an Techniken, an praktischen Anweisungen, wie man mit Menschen therapeutisch umzugehen habe. Die Feststellung ist natürlich nicht falsch, und es liegt auch auf der Hand, dass die Analytische Psychologie durch dieses Fehlen dem Denkmodus der Technik nicht entspricht.
Labyrinth und Minotauros
Authors: Schock Werner
Published: April 2003

Leider besteht für diesen Artikel keine Zusammenfassung. Als Einstieg stellen wir den Textanfang zur Verfügung.Während die wenigsten sich für die altkretische Kochkunst oder den Schiffsbau interessieren, übt die Geschichte vom Minotauros im Labyrinth eine weitgehende Faszination aus, die schon immer die Phantasie beschäftigt hat. Es ist die Eigentümlichkeit von Märchen, Sagen und Mythen, dass ihre Reden einen existentiellen, das menschliche Selbst betreffenden, Sinn haben. Die Geschichte vom Minotauros im Labyrinth zeigt in ihren unterschiedlichen Schichtungen Elemente aller drei Gattungen. Wenn sie im folgenden hauptsächlich als Mythos benannt wird, dann liegt der Grund darin, dass die menschliche Geschichte im Umkreis einer göttlichen Geschichte erscheint, was ihr eine möglichst weitgehende innere Umfänglichkeit und Allgemeinheit gibt.
Spatial Distribution of Responses to Simple and Complex Sounds in the Primary Auditory Cortex
Authors: Schreiner Christoph E.
Published: April 2003

The basic functional organization of the cat primary auditory cortex is discussed as it is revealed by electrophysiological studies of the distribution of elementary receptive field (RF) parameters. RFs of cortical neurons have been shown to vary considerably from neuron to neuron; additionally, specific RF properties vary independently. Furthermore, some of the RF properties are nonhomogeneously distributed across the auditory cortex and can be interpreted as forming ‘maps’ that represent specific stimulus information in a topographic way. Accordingly, the functional organization of the primary auditory cortex is interpreted as a series of superimposed independent parameter maps. The consequences of such a layout for the spatial and temporal coding of pure tones and speech sounds is illustrated and ramifications for the interpretation of far-field event-related potentials are discussed.
Neuronal Responses across Cortical Field A1 in Plasticity Induced by Peripheral Auditory Organ Damage
Authors: Rajan R. , Irvine D.R.F.
Published: April 2003

The adult auditory cortex is capable of a plastic reorganization of its tonotopic map after damage to restricted parts of the cochlear sensory epithelium. We examine the precise conditions of cochlear damage required to demonstrate such plasticity in the primary auditory cortex (A1) of the cat and the changes observed in neuronal responses in the A1 which has reorganized in plasticity of the tonotopic map. From these data we attempt to predict the conditions required for similar plasticity to occur in humans after coachlear damage.
Reliability of 80-Hz Amplitude- Modulation-Following Response Detected by Phase Coherence
Authors: Aoyagi Masaru , Suzuki Yutaka , Yokota Masashi , Furuse Hidekazu , Watanabe Tomoo , Ito Tsukasa
Published: April 2003

The reliability and frequency specificity of the 80-Hz amplitude-modulation-following response (80-Hz AMFR) during sleep detected by phase coherence as a measure of the hearing threshold was evaluated in 169 affected ears of 125 children with hearing impairment. The 80-Hz AMFR at a carrier frequency of 1000 Hz was monitored in all 169 ears and the auditory brainstem response (ABR) elicited by 1000-Hz tone pips was evaluated in 93 ears. Both responses were examined during sleep, and the thresholds were compared with the behavioral hearing threshold, which was determined by standard pure-tone audiometry or play audiometry. In 24 ears of 22 children with various patterns of audiogram, the 80-Hz AMFR was examined at different carrier frequencies, and the threshold pattern was compared with the pure-tone audiogram to investigate the frequency specificity of 80-Hz AMFR. The mean and standard deviation of the difference between the 80-Hz AMFR at a carrier frequency of 1000 Hz and pure-tone thresholds of 1000 Hz was 3.8 and 12.9 dB, and that between the ABR and pure-tone thresholds was 6.8 and 14.1 dB, respectively. The threshold patterns of 80-Hz AMFR clearly followed the corresponding audiogram patterns in all types of hearing impairment. The measurement of 80-Hz AMFR thus appears to be accurate in hearing assessment and to have good frequency specificity in children during sleep.
Human Frequency-Following Responses to Two-Tone Approximations of Steady-State Vowels
Authors: Krishnan Ananthanarayan
Published: April 2003

Auditory nerve single-unit population studies have demonstrated that phase-locking plays a dominant role in the neural encoding of the spectrum of speech sounds. Since the scalp-recorded human frequency-following response (FFR) reflects synchronous, phase-locked activity in a population of neurons in the rostral auditory brainstem, it was reasoned that the human FFR might preserve information about certain acoustic features of speech sounds. FFRs to three different two-tone approximations of vowels (/u/,/c/, and /a/) were obtained from 10 normal-hearing human adults at 85, 75, 65 and 55 dB nHL. Spectrum analyses of the FFRs revealed distinct peaks at frequencies corresponding to the first and the second formants across all levels suggesting that phase-locked activity among two distinct populations of neurons are indeed preserved in the FFR. Also, the FFR spectrum for vowels /c/ and /a/ revealed a robust component at 2F1–F2 frequency suggesting that the human FFR contains a neural representation of cochlear nonlinearity. Finally, comparison of FFRs to the vowel approximations and the individual components at F1 and F2 revealed effects that may be suggestive of two-tone synchrony suppression and/or lateral inhibition. These results suggest that the scalp-recorded FFR may be used to evaluate not only neural encoding of speech sounds but also processes associated with cochlear nonlinearity.
Intracochlear Acoustic Pressure Measurements: Transfer Functions of the Middle Ear and Cochlear Mechanics
Authors: Magnan Pascal , Dancer Armand , Probst Rudolf , Smurzynski Jacek , Avan Paul
Published: April 2003

Direct intracochlear acoustic pressure recordings (from 20 to 20,000 Hz) are used to measure the middle-ear transfer functions (forward and reverse) and to better understand the cochlear mechanics in the guinea pig. In the forward direction, the middle-ear transfer function is strongly dependent on the frequency and presents a maximum of +30 dB at 1,000 Hz (bulla open). In the reverse direction, the middle-ear transfer function looks like an ideal reverse middle-ear pressure transformer with –35 dB gain and 0° phase lag from 20 to 8,000 Hz (bulla open, closed ear canal). Passive cochlear mechanics is studied with the help of intracochlear pressure measurements and differential cochlear microphonic potential recordings in the different turns.
Measurements of Ossicular Vibrations in the Middle Ear
Authors: Schön Franz , Müller Joachim
Published: April 2003

The vibrations of the ossicles were measured with a laser Doppler vibrometer in temporal bone specimens. The data contradicted the generally accepted view that the malleus and incus rotate about a fixed axis. The vibrations of the ossicles show a more complex pattern and, consequently, a more sophisticated model is needed to portray the behaviour of the middle ear in a satisfactory manner. But in turn models with many degrees of freedom make the identification process a very difficult task. This dilemma can be resolved if the system is divided into subsystems of less complexity where each subsystem can be studied in an appropriate manner. The excitation by electrostatic forces, as applied in this study, seems to be a powerful tool to make possible a study of parts of the ossicular chain.
Behavioral and Neurophysiological Thresholds for Electrical Cochlear Stimulation in the Deaf Cat
Authors: Beitel Ralph E. , Vollmer Maike , Snyder Russell L. , Schreiner Christoph E. , Leake Patricia A.
Published: April 2003

Psychophysical detection thresholds for unmodulated electrical pulse trains or for sinusoidally amplitude-modulated (SAM) pulse trains were estimated in deaf juvenile cats using a conditioned avoidance paradigm. Biphasic current pulses (0.2 ms/phase) were delivered by scala tympani electrodes consisting of 4–8 electrode contacts driven as bipolar pairs. Electrical auditory brainstem response (EABR) thresholds were obtained periodically, and at the conclusion of behavioral training, response thresholds were obtained for neurons in the inferior colliculus (IC) and the primary auditory cortex (A1) in acute physiological experiments in the same animals. The results of the study include: (1) detection thresholds for unmodulated pulse trains and for SAM pulse trains were virtually identical; (2) EABR thresholds and behavioral thresholds were significantly correlated, although EABR thresholds consistently overestimated behavioral thresholds; (3) the lowest thresholds in the IC and the A1 were significantly correlated with behavioral thresholds, and (4) mean lowest thresholds in the IC and the A1 were essentially the same as the mean psychophysical detection threshold in the trained deaf cats.
Classification of Passive Auditory Event-Related Potentials Using Discriminant Analysis and Self-Organizing Feature Maps
Authors: Schönweiler Rainer , Wübbelt Peter , Tolloczko Ryczard , Rose Christina , Ptok Martin
Published: April 2003

Discriminant analysis (DA) and self-organizing feature maps (SOFM) were used to classify passively evoked auditory event-related potentials (ERP) P1, N1, P2 and N2. Responses from 16 children with severe behavioral auditory perception deficits, 16 children with marked behavioral auditory perception deficits, and 14 controls were examined. Eighteen ERP amplitude parameters were selected for examination of statistical differences between the groups. Different DA methods and SOFM configurations were trained to the values. SOFM had better classification results than DA methods. Subsequently, measures on another 37 subjects that were unknown for the trained SOFM were used to test the reliability of the system. With 10-dimensional vectors, reliable classifications were obtained that matched behavioral auditory perception deficits in 96%, implying central auditory processing disorder (CAPD). The results also support the assumption that CAPD includes a ‘non-peripheral’ auditory processing deficit.
Intracortical Mechanisms of Mismatch Negativity Dysfunction in Schizophrenia
Authors: Javitt Daniel C.
Published: April 2003

Event-related potentials provide an objective index of neurocognitive dysfunction in schizophrenia. Schizophrenia subjects show a decreased mismatch negativity (MMN) amplitude relative to age- and sex-matched controls, along with a characteristic pattern of MMN dysfunction across conditions. Deficits in MMN generation are accompanied by (1) impaired precision of auditory sensory memory performance and (2) an interstimulus-interval-dependent deficit in auditory N1 generation. Similar deficits are observed following systemic or local infusion of N-methyl-D-aspartate (NMDA) antagonists, supporting glutamatergic and phencyclidine/NMDA models of the disorder. Deficits in MMN generation may also be seen following focal cortical damage, especially to the dorsolateral prefrontal cortex. MMN thus provides a useful tool for investigating mechanisms underlying brain dysfunction in schizophrenia.
Development of Chondroitin Sulfate Proteoglycans in the Central Auditory System of Rats Correlates with Acquisition of Mature Properties
Authors: Friauf Eckhard
Published: April 2003

Chondroitin sulfate proteoglycans (CSPGs) are macromolecules which regulate the structural organization of the extracellular matrix and can mediate cell migration and axonal growth. Here the spatiotemporal distribution of CSPGs in the central auditory system of rats was investigated using a polyclonal antiserum. In adult brains, CSPGs surrounded many neuronal cell bodies and proximal dendrites at all stations of the auditory pathway except the medial geniculate body. During development, CSPG expression became visible at postnatal day (P) 4 in the superior olivary complex, at P8 in the midbrain, and at P18 in the cortex. Immunoreactivity increased strongly until P12 in the brainstem and until P24 in the cortex. The adult-like pattern in the pontine nuclei, the midbrain, and the cortex was seen at P12, P29, and P35, respectively. The relatively late expression of strong immunoreactivity indicates that the CSPGs are involved in the maturation of axonal connections, but not in early processes such as cell migration or neurite outgrowth.
Successful Treatment of Tumoral Calcinosis Using CAPD Combined with Hemodialysis with Low-Calcium Dialysate
Authors: Kuriyama Satoru , Tomonari Haruo , Nakayama Masaaki , Kawaguchi Yoshindo , Sakai Osamu
Published: April 2003

Successful treatment of tumoral calcinosis using continuous ambulatory peritoneal dialysis (CAPD) combined with hemodialysis is described. A 32-year-old male patient with a 2-year history of CAPD rapidly developed multiple metastatic calcification (tumoral calcinosis) adjacent to his fingers, elbows, and knee joints. Tests showed severe hyperphosphatemia, moderate hypercalcemia, and increased Ca-P product without elevation of intact parathyroid hormone. An enlarged parathyroid gland was not found by echography. In order to rapidly lower the excessive Ca and P levels, a combined therapy with CAPD and vigorous transient hemodialysis using a low-Ca dialysate was performed. In parallel, the patient was given calcitonin, bisphosphonate, and short-term Al to ameliorate the metastatic calcifications more effectively. The result was dramatic with disappearance of the tumoral calcinosis as well as improvement in subjective symptoms within a few months. The present case suggests that combined therapy with hemodialysis and CAPD using a low-Ca dialysate, together with Ca-modulating agents, can be effective in ameliorating tumoral calcinosis in patients on CAPD.
In vitro Characterization of a Membrane-Based Low-Density Lipoprotein Affinity Adsorption Device
Authors: Soltys Paul J. , Etzel Mark R.
Published: April 2003

The objective of this study was to explore the use of microporous membranes as an alternative substrate to porous beads in affinity adsorption of low-density lipoprotein (LDL) for therapeutic purposes. Flat sheet immunoaffinity membranes containing a polyclonal antibody preparation were utilized as the affinity substrate. The antibody was covalently immobilized to the surface through a poly(ethylene glycol) (PEG) spacer. Equilibrium adsorption of LDL from plasma was measured. Adsorption from plasma and elution of bound LDL using citrate buffer were studied as a function of flow rate.Specific capacity was as great as 2 mg apolipoprotein B per milliliter membrane volume. The superior transport properties of the membrane allowed rapid adsorption and regeneration, which translated to a large number of adsorptive cycles that can be performed within a given treatment time. On the basis of in vitro performance characteristics, it is estimated that an immunoaffinity membrane device can provide a reduction in patient plasma LDL concentration comparable to that provided by packed columns, but with almost an 80% reduction in the device volume.
Systemic Vascular Resistance in Intradialytic Hypotension Determined by Means of Impedance Cardiography
Authors: Straver B. , Roggekamp M.C. , de Vries P.M.J.M. , ter Wee P.M.
Published: April 2003

Background: Recurrent intradialytic hypotension still is a major source of discomfort in hemodialysis patients today, its origin being subject to extensive research. Different hypotheses have been raised to unravel this problem, without forming one coherent point of view. The aim of this study was to gain more insight into the mechanisms causing intradialytic hypotension by determining cardiovascular performance noninvasively during hemodialysis in a large group of patients. Methods: In the present study the variations in blood volume, stroke volume, cardiac output and systemic vascular resistance were investigated in 68 patients on chronic intermittent hemodialysis utilizing bioelectrical impedance cardiography. In addition, blood volume was monitored continuously with an on-line optical device. Results: Twenty-four patients experienced symptomatic hypotension during dialysis treatment. Compared to the hemodynamically stable patients, the hypotensive patients manifested a slightly greater decline in blood volume (mean ± SEM; –9.4 ± 1.2 vs. –6.5 ± 0.8%, p = 0.04) and cardiac output (–11.8 ± 4.2 vs. –7.3 ±2.7%, p = NS). The main difference, however, was a highly significant decrease in systemic vascular resistance (–17.9 ± 4.4%) in the hypotensive group compared to a rise in the stable group (+6.2 ± 3.5%, p < 0.001). Conclusion: Intradialytic hypotension seems the consequence of an inadequate compensatory response to ultrafiltration-induced blood volume reduction, resulting in a fall in systemic vascular resistance. The degree of hypovolemia itself appears to be less important in the origin of acute, intradialytic hypotensive episodes. Noninvasive monitoring during hemodialysis provides an opportunity to gain more insight into the pathophysiology of intradialytic hypotension and offers the possibility for controlled intervention and possible prevention of this complication.
Salt and Hypertension in End-Stage Renal Disease
Authors: Kooman J.P. , Leunissen K.M.L. , Luik A.J.
Published: April 2003

Salt and fluid overload play an important role in the pathogenesis of hypertension in patients with end-stage renal disease. However, in the individual patient, the relation between salt loading and blood pressure response is variable and appears to be influenced by various neurohumoral regulatory mechanisms. This may also have implications for the pathogenesis of structural cardiovascular abnormalities in patients with end-stage renal disease.
Analysis of the Influence of the Infusion Site on Dialyser Clearances Measured in an in vitro System Mimicking Haemodialysis and Haemodiafiltration
Authors: Ficheux A. , Argilés A. , Bosc J.Y. , Mion C.
Published: April 2003

Background: Blood flow (QB), dialysate flow (QD), and dialyser characteristics are the three major factors driving dialysis efficacy. Haemodiafiltration has added an increased convective volume to increase efficacy. We aimed to assess the influence of the infusion site of the replacement fluid in an in vitro system emulating haemodiafiltration. Methods: An in vitro system allowing us to control the dialysate temperature, concentration gradient, the flow of both dialyser sides over a range wider than that compatible with clinic, was set to evaluate the influence of the different parameters on dialysis efficacy. The total ion clearance was used as an accepted method for small molecule clearance assessment. Cellulose triacetate (CT190C, Baxter; FB170U, Nipro) and polysulfone (HF80, Fresenius) dialysers were included in the study. Dialysis as well as on-line diafiltration both with pre- and postdilutional infusion were assessed. The experimental conditions presented in this study included QD 620 and 970 ml/min. The convective flows ranged from 50 to 200 ml/min. Results: For a QD = 620 ml/min and a QB = 350 ml/min the total ion clearance ranged from 269 to 274 for HF80, from 291 to 294 for FB170 and from 294 to 302 for CT190. The variability of the measurements was very low (SD < 1%). Total ion clearance increased by 17–21% when QB was raised from 300 to 400 ml/min. Increasing QD from 420 to 970 ml/min (for QB = 350 ml/min), resulted in an increase in total ion clearance which was more marked at lower QD (from 420 to 620 ml/min) and plateaued thereafter (from 620 to 970 ml/min). Postdilutional on-line diafiltration with 100 ml/min of infusate resulted in an additional increase in total ion clearance of 5.4–8.6%. This increase was proportional to the infused volume. On the contrary, predilutional on-line diafiltration resulted in a decrease in total ion clearance which was also proportional to the infused volume (between –5.1 and –6.9% at 100 ml/min infusion volume and –9.7 to –12.9% at 200 ml/min). Conclusions: The present in vitro system provided accurate and reproducible results on dialyser clearances. Our experiments confirmed previous studies on the influence of QB and QD on dialyser efficacy. Further, they show that the proportional increase in postdilutional on-line diafiltration is lesser than that previously reported. More importantly, they also show that pre-dilution infusion in high efficiency systems results in a drop in dialyser clearance compared to dialysis alone, again proportional to the infusion rate. Thus, increasing the convective flow may increase dialysis efficacy even more than increasing QD alone. However, the choice of infusion site is crucial to obtaining this benefit in small molecule clearances.
Haemolipodialysis
Authors: Wratten M.L. , Navino C. , Tetta C. , Verzetti G.
Published: April 2003

Haemodialysis is associated with increased oxidant stress. This appears to be due to (1) an increased production of free radicals during haemodialysis, (2) a net reduction of many antioxidants and (3) factors intrinsic to the uremic state. These alterations can lead to cardiovascular disease and many of the pathologies associated with chronic renal failure. Haemolipodialysis (HLD) is a new haemodialytic technique aimed at reducing oxidant stress and removing hydrophobic or protein bound toxins. The technique uses dialysate containing ascorbic acid (vitamin C) and polyunsaturated unilamellar liposomes containing α-tocopherol (vitamin E). The liposomes interact with blood components at the haemodialysis membrane without passage through the membrane. Vitamin C and vitamin E are added to the system to protect the cell and plasma components from reactive oxygen species produced from activated inflammatory cells. This technique may provide a new approach in preventing free radical-associated pathologies in chronic haemodialysis patients.
Adequacy, Nutrition, and Biocompatibility: Their Relevance on Clinical Outcome in Haemodialysis Patients
Authors: Movilli E.
Published: April 2003

Mortality and morbidity in haemodialysis patients remain high in spite of great improvements in technology that one would expect to improve patient survival. The general effort of the scientific community to minimise morbidity and mortality in haemodialysis patients has identified three main topics that can influence patient outcome and well-being: the dialysis dose, nutrition, and biocompatibility of the dialysis procedure. The aim of this review is to provide a critical assessment of the current clinical evidence supporting a role for each one of these three main factors on patient outcome.
New Perspectives in the Treatment of Acute Renal Failure
Authors: Ronco C. , Ghezzi P. , Bellomo R. , Brendolan A.
Published: April 2003

The evolution of technology and biomaterials has permitted a parallel development of renal replacement therapies in the acute, critically ill patient. From the original description of continuous arterio-venous haemofiltration, new techniques such as continuous veno-venous haemofiltration, haemodiafiltration and high flux dialysis have been developed and clinically utilised. A parallel improvement in efficiency has been achieved with urea daily clearances as high as 50 litres or more. The use of special highly permeable dialysers has also permitted to increase the clearances of larger solutes thus leading to significant removals of chemical substances involved in the acute inflammation and sepsis. In this field, recent observations have suggested to use haemofiltration with high volumes of fluid exchange. The hardware and software of the newer continuous renal replacement therapies (CRRT) are certainly the key point in achieving these results and in safely performing such challenging techniques.
C-Reactive Protein as a Marker of Chronic Inflammation in Uremic Patients
Authors: Panichi Vincenzo , Migliori Massimiliano , De Pietro Stefano , Taccola Daniele , Bianchi Anna Maria , Norpoth Maria , Giovannini Luca , Palla Roberto , Tetta Ciro
Published: April 2003

Cardiovascular complications caused by an accelerated atherosclerotic disease represent the largest single cause of mortality in chronic renal failure patients. The rapidly developing atherosclerosis of the uremic syndrome appears to be caused by a synergism of different mechanisms, such as malnutrition, oxidative stress and genetic factors. Recent studies provide evidence that chronic inflammation plays an important role in the pathogenesis of cardiovascular diseases. Elevated serum levels of plasma C-reactive protein (CRP) are associated with an increased risk of experiencing myocardial infarction and sudden cardiac death in apparently healthy subjects. Several recently published papers have confirmed this strong association between CRP and the extent and severity of the atherosclerotic processes. In patients affected by predialytic renal failure, increased levels of CRP and interleukin (IL)-6 were recorded in 25% of our population; CRP and IL-6 were inversely related with renal function. These data suggest the activation – even in the predialytic phase of renal failure – of mechanisms known to contribute to the enhanced cardiovascular morbidity and mortality of the uremic syndrome. In recent years we have investigated the hypothesis that the chronic inflammatory state of the uremic patient could at least in part be due to the dialytic technique. We provide evidence suggesting that the increase of CRP in stable dialytic patients may be due to the stimulation of monocyte/macrophage by backfiltration of dialysate contaminants.
Why Hemodialysis Patients Are in a Prooxidant State? What Could Be Done to Correct the Pro/Antioxidant Imbalance
Authors: Morena Marion , Cristol Jean-Paul , Canaud Bernard
Published: April 2003

Oxidative stress which results from an imbalance between reactive oxygen species production and antioxidant defense mechanisms is now well recognized in hemodialysis (HD) patients and could be involved in dialysis-related pathologies such as accelerated atherosclerosis, amyloidosis and anemia. In order to evaluate the rationale for preventive intervention against oxidative damage during HD, we review the factors that are implied and may be responsible for the imbalance between pro- and antioxidative mechanisms. The inflammatory state mainly due to hemobioincompatibility of the dialysis system plays a critical role in the production of free oxygen radical species contributing by this way to worsen the prooxidant status of uremic patients. Two factors largely contribute to the stimulation of the NADPH oxidase: hemoreactivity of the membrane and trace amounts of endotoxins. The antioxidant system is severely impaired in uremic patients and gradually altered with the degree of renal failure. HD could further impair this antioxidant system mainly by losses of (a) hydrophilic unbound small-molecular-weight substances such as vitamin C, (b) trace elements and (c) enzyme-regulatory compounds. Two main axes may be proposed in order to prevent and/or to decrease oxidative stress in HD patients. One consists in improving the hemocompatibility of the dialysis system mainly by using a dialyzer with low hemoreactivity and ultrapure, sterile, nonpyrogenic dialysate. The other consists in supplementing the deficiency patients with antioxidants. This could be achieved by oral or perdialytic supplementation. Vitamin E could be bound on dialyzer membrane. Alternatively, hemolipodialysis consists in loading HD patients with vitamin C or E via an ancillary circuit made of vitamin E-rich liposomes. The presence of liposomes could also facilitate the removal of hydrophobic prooxidative substances.
Soluble Adhesion Molecules and Cytokines in Patients with Myasthenia Gravis Treated by Plasma Exchange
Authors: Tesař V. , Jelínková E. , Jirsa Jr. M. , Bakosová M. , Pitha P. , Chábová V.
Published: April 2003

Plasma exchange (PE) is an effective therapeutic method used in patients with myasthenia gravis (MG) refractory to common therapy and/or with life-threatening respiratory complications. Except for acetylcholine receptor antibodies (AChRAbs), some other inflammatory mediators possibly activated in MG may also be removed during PE. Serum levels of soluble adhesion molecules (sICAM-1 and sVCAM-1), IL-6 and soluble receptors for IL-2 (sIL-2R), IL-6 (sIL-6R) and TNFα (sTNF-R II) were measured in 20 MG patients assigned to treatment with PE. On the basis of the serum levels of AChRAb the patients were subdivided into 2 groups (8 patients with low AChRAb, 12 patients with high AChRAb). Soluble adhesion molecules and cytokines were measured before the first and last PE, at the end of the first PE and in the samples of plasma filtrate obtained during the first PE. Before the first PE patients with MG had higher serum levels of sICAM-1, sVCAM-1, sIL-2R and sTNF-R II than controls. Both after the first PE and during the course of PE, a substantial decrease in serum levels of AChRAb, sICAM-1 and sVCAM-1 was recorded. However, serum levels of sIL-2R and sTNF-R II were not significantly influenced by either a single treatment or during the course of PE. There were high levels of AChRAb, soluble adhesion molecules and soluble cytokine receptors in plasma filtrates too. Patients with high circulating AChRAb had higher serum levels of sICAM-1 and sVCAM-1 than patients with low AChRAb. Increased serum levels of soluble adhesion molecules and soluble cytokine receptors in patients with MG suggest some systemic activation of the immune response which is more pronounced in patients with high circulating AChRAb. PE led to the decrease in serum AChRAb and soluble adhesion molecules due to their effective filtration but, on the other hand, serum levels of soluble cytokine receptors were not influenced by PE, in spite of their effective filtration which is probably counteracted by their increased production, possibly stimulated by the contact of the blood with the synthetic membrane.
One-Year Immunological Evaluation of Chronic Hemodialysis in End-Stage Renal Disease Patients
Authors: Meier P. , von Fliedner V. , Markert M. , van Melle G. , Deppisch R. , Wauters J.-P.
Published: April 2003

Background: Much research has been devoted to the determination of acute leukocyte activation as well as acute cytokines production during and after blood hemodialysis membrane interaction. In contrast, few studies deal with chronic immunological evaluation of T-cell activation markers in hemodialysis. Methods: We evaluated different immune parameters using a modified cellulose low-flux hemophan vs. synthetic high-flux polyamide membrane during 1 year in 35 stable chronic hemodialysis patients. Leukocyte counts, lymphocyte subpopulations, T-cell activation markers (CD69, CD25, HLA-DR, CD54, CD62L, CD45RO, CD11a, CD28), complement-activation products (C3a) and serum elastase were measured at 0, 3, 6 and 12 months in the two patient groups and compared to 13 healthy control subjects. Results: Over dialysis time, all patients showed a significant level elevation of CD69/CD3 (p < 0.005) and CD25/ CD3 (p < 0.005) phenotypes. In contrast, HLA-DR and CD45RO remained unchanged suggesting a truncated pattern of activation. T lymphocyte subset analysis showed in both hemodialyzed groups a significant decrease in the expression of CD54 (ICAM-1) when compared to controls (p < 0.005). C3a and elastase measurements showed a significant upward trend with dialysis time in both hemodialyzed groups. Conclusion: Although the immunological changes seen in chronic hemodialyzed patients must be interpreted in conjunction with their basal uremic states and the membrane permeability properties, our study suggests that 1-year immunological evaluation of hemodialysis membranes biocompatibility is associated with changes in the pattern of chronic T-cell activation, which is in part related to the use of a particular membrane type. Moreover, some key molecules (CD54) are affected in patients with end-stage renal disease undergoing hemodialysis.
Haematopoietic Progenitors from Umbilical Cord Blood
Authors: Todaro A.M. , Pafumi C. , Pernicone G. , Munda S. , Pilastro M.R. , Russo A. , Farina M. , Messina A.
Published: April 2003

Background/Aim: The aim of this study is to improve the obstetrician-based cord blood collection system and an efficient recovery of CD34+ haematopoietic progenitor stem cells. Methods: CD34+ cells were purified from total blood using a positive selection enrichment method, called Mini-Macs. Results: The final yield of CD34+ cells we obtained was 104 cells/ml, with a CD34+ purity of 99%. Conclusion: Our results confirm that, by using this method, it is possible to get a significant stem cell number, thus improving transplanting both peripheral stem cells and umbilical cord ones.
Successful Use of Central Venous Catheter as Permanent Hemodialysis Access: 84-Month Follow-Up in Lucania
Authors: Di Iorio B. , Lopez T. , Procida M. , Marino P. , Valente V. , Iannuzziello F. , Bombini A. , Bellizzi V. , Terracciano V. , Bagnato C. , Casino F. , Gaudiano V. , Mostacci D. , Santarsia G. , Biscione R. , Caputo A. , Ferlan G. , Lauria M.A. , Marinaro G. , Molinari R. , Sanicandro D. , Lotito M.A. , Plastino G. , Carretta P.
Published: April 2003

Cuffed tunneled venous access catheters are commonly used for temporary and permanent access in hemodialysis (HD) patients. These catheters serve an essential role in providing permanent access in subjects in whom all other access options have been exhausted. The predominant complications are catheter thrombosis, catheter fibrin sheating and infection. The aim of this study was to evaluate long-term survival and complications of permanent venous catheters (PVC) placed for the purpose of HD during the period from January 1992 to December 1998, at the Dialysis Units of Lucania (a southern Italian region). A total of 98 PVC were placed in 88 patients during this period. The catheters used were of three types: (a) 72 VasCath Soft Cell catheters (Bard Instrument Company, Toronto, Ont., Canada); (b) 22 PermCath catheters (Quinton Instrument Company, Seattle, Wash., USA), and (c) 4 Tesio catheters (Bellco SpA, Mirandola, Italy). Survival curves of catheters were calculated using the Kaplan-Meier product-limit estimator. The patient survival was 60% at the 78th month. Actually, 52 patients (27 males, 25 females) are still alive: 15 (26.9%) of these patients have diabetes mellitus and 1 has been transplanted. The actuarial survival rate of PVC was 89% in the whole population studied and 82% in subjects alive after 84 months. Twenty-five patients (28.4%) had PVC as the first reliable vascular access. Long-term complications occurred 27 times (1 episode every 44.81 month/patient) as: breakage (3.1%); thrombosis (10.2%); displacement (2.0%); subcutaneous tunnel bleeding (3.1%); inadequate blood flow (7.1%), and infection (10.2%). In conclusion, our data confirm that PVC might represent an effective long-term blood access route for HD. Again, PVC are getting the access of choice for selected patients (i.e., older subjects with cardiovascular diseases and cancer patients) and are enjoying a dramatic increase in use for subjects who are terrified of repetitive venopuncture.
lntron based radiation hybrid mapping of 15 complex I genes of the human electron transport chain
Authors: Emahazion T. , Beskow A. , Gyllensten U. , Brookes A.J.
Published: April 2003

At least 34 complex I subunits of the electron transport chain are encoded by the nuclear genome, but only 14 of these have been mapped in the human. To rapidly map additional subunits, we have performed a combination of database mining and direct “wet” experimentation to identify intron and/or 5′ upstream genomic DNA regions for 16 complex I genes. Wet experimentation was applied to 5 genes, and involved direct PCR amplification of introns by inter-exon PCR or splinkerette based PCR walking. Database mining was applied to 11 genes, and entailed the identification of incompletely spliced mRNAs and genomic CpG island clone sequences. This data was in files that carried no documentary description of the non-exon regions. Non-exon sequences were thus derived for 15 complex I genes and used to design functional gene specific PCR assays. Radiation hybrid mapping of these PCRs located 15 complex I genes to chromosomes l, 4, 5 (2 genes), 7 (2 genes), 8, 9 (2 genes), 11, 14, 16 (2 genes), 18, and 19.