bluuebunny/crossref_metadata_2025 huggingface dataset:
Methylenetetrahydrofolate Reductase Gene C677T Polymorphism, Plasma Homocysteine and Folate in End-Stage Renal Disease Dialysis and Non-Dialysis Patients
Authors: Zychma MarcinJ. , Gumprecht Janusz , Grzeszczak Wladyslaw , Zukowska-Szczechowska Ewa
Published: April 2003

Background: It has been recently suggested that the presence of the methylenetetrahydrofolate reductase gene 677TT genotype is associated with younger age at initiation of dialysis, thus raising a hypothesis that younger renal patients carrying the TT genotype are at higher risk to develop end-stage renal disease. The aim of this study was to test the association between the C677T polymorphism and the presence of end-stage renal disease using a family-based study design. Material and Method: C677T polymorphism was genotyped in a group of 247 family trios (offspring affected with end-stage renal disease, dialysed or conservatively treated, and both parents). Transmission/disequilibrium test (TDT) was used to evaluate allele transmission from heterozygous parents to affected offspring. Results: The TDT analysis revealed no significant deviation in the transmission of the MTHFR C677T alleles to CRF patients (51 vs. 49% for the C allele and T allele transmission, respectively). We observed a significant relationship between MTHFR genotypes and total plasma homocysteine (tHcy), as well as folate concentration. Also, plasma tHcy and folate were negatively correlated. Conclusion: Our results did not show any association between the MTHFR reductase C677T polymorphism and the increased risk of the development of end-stage renal disease. Whether this polymorphism contributes to the faster rate of decline of renal function in renal patients, must be evaluated further.
Interleukin-6 Stimulates Tubular Regeneration in Rats with Glycerol-Induced Acute Renal Failure
Authors: Homsi Eduardo , Ribeiro-Alves Maria A. , Lopes de Faria José B. , Dias Eliana P.O.
Published: April 2003

Interleukin-6 stimulates tubular regeneration in rats with glycerol-induced acute renal failure. Background: Interleukin 6 (IL-6) is a pleiotropic cytokine released after endotoxemia, trauma and organ injury. IL-6 may act in cellular proliferation activating transduction signals and Ras/Map cascade or the HGF/c-met axis. We tested the effect of IL-6 in the regeneration of tubular epithelia after acute tubular necrosis (ATN) in rats. Methods: Rats with glycerol-induced acute renal failure (Gly-ARF) were treated with IL-6 200 µg/kg/day. Functional, histological and immunohistochemical tests were done 24 and 72 h after Gly-ARF to localise mitotic cells (BrdU). The renal expression of c-met (Western-Blot) and circulating levels of HGF (ELISA) were also determined. Results: Rats with Gly-ARF had reduced creatinine clearance that was not influenced by IL-6. The histological appearance of ATN was also unaffected by IL-6. The IL-6 treated rats showed a significant increase in tubular cell proliferation in cortex and medulla, as well as in the expression of c-met protein in the renal cortex, compared to untreated Gly-ARF rats. The plasma HGF concentration was equally elevated in treated and untreated Gly-ARF rats. Discussion: IL-6 stimulates tubular regeneration after Gly-ARF and increases the expression of c-met in the renal cortex. Gly-ARF rats have high circulating levels of HGF that is targeted to act in the injured kidneys by the IL-6 overexpressed renal c-met.
A Case of Postpartum Cerebellar Infarction with Hemolysis, Elevated Liver Enzymes, Low Platelets (HELLP) Syndrome
Authors: Soh Yoko , Yasuhi Ichiro , Nakayama Daisuke , Ishimaru Tadayuki
Published: April 2003

Cerebellar infarction has been described rarely during pregnancy, and there has been no case report of cerebellar infarction with hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome. A 39-year-old Japanese primipara had postpartum HELLP syndrome soon after cesarean section at term. Several hours later, she developed cerebellar infarction which was fatal. HELLP syndrome may have contributed to the development of cerebellar infarction in the case.
Identification of the Prelinitis Condition in Gastric Cancer and Analysis of TGF-β, TGF-β RII and pS2 Expression
Authors: Morita Katsuo , Fujimori Takahiro , Ono Yuko , Hiraishi Hideyuki , Yoshiura Kenta , Shimada Tadahito , Sugaya Hitoshi , Terano Akira
Published: April 2003

In the present study, we performed an immunohistochemical examination of the expression of transforming growth factor-β (TGF-β), TGF-β type II receptor (TGF-β RII) and a trefoil peptide, pS2, in the several types of gastric cancer. The TGF-β:TGF-β RII ratios of IIc-like type and Ménétrier type closely resembled that of linitis type. pS2 was intensely expressed in cytoplasm of the superficial and foveolar epithelium, as well as in scirrhous type gastric cancers which retained the gastric or intestinal phenotype. However, pS2 expression was significantly (p < 0.05) reduced in linitis type gastric cancers (1 of 6; 17%) when compared with other scirrhous types of gastric cancers (13 of 22; 59%). A decrease in the TGF-β:TGF-β RII ratios in linitis type, IIc-like type and Ménétrier type gastric cancers may be associated with the fibrosis seen in these types of cancer. Furthermore, reduction of pS2 expression in linitis type gastric cancer may represent a dedifferentiation of the cancer from gastric or intestinal phenotype. Judging by the expression patterns of TGF-β, TGF-β RII and pS2, it is possible that IIc-like type and Ménétrier type gastric cancers are precursor lesions of linitis type gastric cancer.
Correlation between ST-T-Segment Changes with Markers of Hemostasis in Patients with Acute Coronary Syndromes
Authors: Ehlers Raila , Büttcher Eva , Eltzschig Holger K. , Kazmaier Silke , Szabo Sebastian , Helber Uwe , Hoffmeister Hans Martin
Published: April 2003

Background: Disturbance of the hemostatic and the inflammatory system plays an important role in the pathophysiology of acute coronary syndromes (ACS). Their markers have been shown to predict further coronary events in patients with ACS. The prognostic value of the admission electrocardiogram (ECG), which is commonly used to evaluate ischemia, was studied previously. We investigated the correlation between serum markers of the hemostatic/inflammatory system and ECG changes in ACS. Methods: A standard 12-lead ECG was obtained from 85 patients with ACS on admission (0d). Markers of the hemostatic and inflammatory system were measured on admission and after 2 days (2d). Results: Patients with ST-T-changes had higher fibrinogen and thrombin-antithrombin III complex (TAT) levels than patients without ECG alterations at both times (fibrinogen: 0d: 492 ± 38 vs. 357 ± 36 mg/dl, p < 0.01; 2d: 633 ± 55 vs. 440 ± 50 mg/dl, p < 0.02; TAT: 0d: 7.2 ± 1.3 vs. 3.6 ± 0.7 µg/l, p < 0.05; 2d: 5.3 ± 0.9 vs. 3.2 ± 0.5 µg/l, p < 0.05). Tissue-type plasminogen activator (TPA) was elevated in patients with ECG changes initially (10.1 ± 0.6 vs. 7.2 ± 0.7 ng/ml, p < 0.02). D-dimers, the acute-phase proteins C-reactive protein, serum amyloid A and the soluble adhesion molecules showed no significance. Conclusions: The data reveal a correlation between electrocardiographic changes and hemostasis in patients with ACS. The association of myocardial damage and a disturbed hemostatic system might stratify patients who are at high risk of suffering further coronary events.
Expression of the ETA and ETB Endothelin Receptor Subtype mRNA in Human Detrusor Cultured Smooth Muscle Cells
Authors: Obara Kenji , Walden Paul D. , Hatano Akihiko , Tomita Yoshihiko , Takahashi Kota , Lepor Herbert
Published: April 2003

The aim of this study was to determine the expression of the endothelin receptor subtype mRNAs in human detrusor cultured smooth muscle cells using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization (ISH). First strand cDNA was made from human detrusor cultured smooth muscle cells total RNA and used for PCR with primers designed to amplify fragments of the ETA and ETB endothelin receptor subtype cDNA sequences. Subcloned fragments of the ETA and ETB endothelin receptor cDNAs were used to synthesize digoxigenin-labeled cRNA probes by in vitro transcription. COS-7 cells transfected with the ETA and ETB receptor cDNAs were used as positive control and to confirm the absence of cross-hybridization due to sequence homology. Both ETA and ETB receptor mRNAs were detected by RT-PCR analysis. By ISH, both ETA and ETB receptor subtype mRNAs were detected. However, ETA signal was much more intense than ETB signal. These results indicate that mRNAs for both ETA and ETB receptors are expressed in detrusor smooth muscle cells of human urinary bladder. The ETA receptor is the predominant detrusor ET receptor.
Bladder Pheochromocytoma: A 3-Year Follow-Up afterTransurethral Resec tion (TURB)
Authors: Baima C. , Casetta G. , Vella R. , Tizzani A.
Published: April 2003

We report a case of a 75-year-old female with pheochromocytoma of the bladder. Clinical evaluation included ultrasonography, intravenous pyelography, CT scan, I-MIBG scintiscan. A transurethral resection was performed for a exophytic tumor of 2 cm diameter. The histological result indicated the diagnosis of bladder pheochromocytoma. Three years later the patient remains disease free. Preoperative diagnosis is established by determination of blood and urine levels of catecholamines and their metabolites is a nonspecific diagnostic tool. The sensitivity of CT scan is 82%. Iodine-methyliodobenzylguanidine (I-MIBG), used by scintiscanning, specifically accumulates in pheochromocytomas. Life-long follow-up is necessary to diagnose late recurrences.
Multisensory Cues and Multimodal Communication in Spiders: Insights from Video/Audio Playback Studies
Authors: Uetz George W. , Roberts J. Andrew
Published: April 2003

Spiders perceive the world using multiple sensory modes, including vibration, vision, and chemical senses, for prey detection and communication. These sensory modes are used in many communication contexts, either individually or in multimodal signaling. Selection for effective signaler-receiver communication and species discrimination is especially strong for these predatory and potentially cannibalistic arthropods, resulting in the evolution of considerable diversity in signaling behaviors. In this paper, we review sensory mechanisms involved in spider signaling and present an overview of recent work done on wolf spiders (Lycosidae) that use multimodal communication (simultaneous visual and vibratory signals) in sexual signals during courtship. The relative importance of visual and vibratory signaling modes, and the use of multiple modes varies among closely related species in the genus Schizocosa, providing a model system for investigating multisensory guidance of complex behavior. Here we examine previous and current research on responses of female spiders to components of male courtship behavior, using several experimental techniques including cue isolation (single sensory modes), video/audio digitization and playback, and cue-conflict (mixed conspecific/heterospecific components) to tease apart elements of multimodal signaling.
Investigation of the Anti-HIV Properties of Oxihumate
Authors: van Rensburg C.E.J. , Dekker J. , Weis R. , Smith T.-L. , Janse van Rensburg E. , Schneider J.
Published: April 2003

A unique process has been developed to convert bituminous coal by controlled wet oxidation followed by base treatment to a water-soluble humate called oxihumate. Oxihumate inhibited HIV-1 infection of MT-2 cells with an IC50 of 12.5 µg/ml. Treatment of free and cell-attached HIV with oxihumate irreversibly reduced infectivity, while the susceptibility of target cells to the virus was not impaired by treatment prior to infection. The infectivity of the HIV particles was inhibited by interference with CD4 binding and the V3 loop-mediated step of virus entry. No viral resistance to oxihumate developed over a 12-week period in vitro. Oxihumate therefore holds promise for the treatment of HIV-infected patients.
Autonomic Dysfunction in Multiple Sclerosis: Correlation with Disease-Related Parameters
Authors: Gunal Dilek Ince , Afsar Nazire , Tanridag Tulin , Aktan Sevinc
Published: April 2003

Cardiovascular autonomic functions were investigated in a prospective, controlled study of 22 consecutive relapsing-remitting multiple sclerosis (MS) patients and 22 healthy subjects using 5 simple noninvasive tests and sympathetic skin response testing. Tests included the heart rate response to deep breathing, valsalva maneuver and standing, blood pressure response to standing and sustained hand grip, and were graded according to the Ewing and Clark classification as early, definite or severe impairment. The relationship between autonomic dysfunction and disease-related parameters such as the expanded disability status scale (EDSS) and disease duration was studied. Ninety percent of the patients had symptoms related with autonomic dysfunction, and 45.5 % had abnormal results in cardiovascular autonomic function testing with 4 patients also having abnormal sympathetic skin responses. Statistical analysis indicated that patients with a long disease duration rather than high EDSS carried a risk of autonomic involvement in MS. Both parasympathetic and sympathetic functions were impaired and this could have been easily overlooked by a standard EDSS follow-up. In this regard, autonomic function testing seems necessary in order to detect subclinical changes in MS patients and should be considered in outcome measures.
Mitochondrial DNA A4336G Mutation in Alzheimer’s and Parkinson’s Diseases
Authors: García-Lozano José Raúl , Mir Pablo , Alberca Román , Aguilera Isabel , Gil Néciga Eulogio , Fernández-López Olga , Cayuela Aurelio , Núñez-Roldan Antonio
Published: April 2003

Objectives: To determine whether the mitochondrial DNA (mtDNA) A4336G mutation represents a risk factor for Spanish patients with both Alzheimer’s disease (AD) and Parkinson’s disease (PD). Material and Methods: One hundred and sixty-one AD and 106 PD unrelated patients were included in the study. Seventy-eight age-matched and 144 randomly chosen healthy subjects served as controls. The frequency of the A4336G mutation in these groups was compared using the χ2 and Fisher’s exact tests. p < 0.05 was established as a statistically significant differential value. Results: The mtDNA A4336G mutation was present in 1/161 of AD patients (0.6%), in 3/106 of PD patients (2.8%), in 1/78 of age-matched controls (1.3%) and in 2/144 of the randomly chosen controls (1.4%). These differences were not statistically significant. Conclusion: Our results do not support the hypothesis that this mutation represents a risk factor for either AD or PD patients, at least in the case of this Spanish sample.
Models and Tests of Linkage and Association Studies of Quantitative Trait Locus for Multi-Allele Marker Loci
Authors: Fan Ruzong , Floros Joanna , Xiong Momiao
Published: April 2003

In this paper, we explore models and tests for association and linkage studies of a quantitative trait locus (QTL) linked to a multi-allele marker locus. Based on the difference between an offspring’s conditional trait means of receiving and not receiving an allele from a parent at marker locus, we propose three statistics Tm, Tm,row and Tm,col to test association or linkage disequilibrium between the marker locus and the QTL. These tests are composite tests, and use the offspring marginal sample means including offspring data of both homozygous and heterozygous parents. For the linkage study, we calculate the offspring’s conditional trait mean given the allele transmission status of a heterozygous parent at the marker locus. Based on the difference between the conditional means of a transmitted and a nontransmitted allele from a heterozygous parent, we propose statistics Tparsi, Tsatur, Tgen and Tm,het to perform composite tests of linkage between the marker locus and the quantitative trait locus in the presence of association. These tests only use the offspring data that are related to the heterozygous parents at the marker locus. Tparsi is a parsimonious or allele-wise statistic, Tsatur and Tgen are satured or genotype-wise statistics, and Tm,het compares the row and column sample means for offspring data of heterozygous parents. After comparing the powers and the sample sizes, we conclude that Tparsi has higher power than those of the bi-allele tests, Tsatur, Tgen, and Tm,het. If there is tight linkage between the marker and the trait locus, Tparsi is powerful in detecting linkage between the marker and the trait locus in the presence of association. By investigating the goodness-of-fit of Tparsi, we find that Tsatur does not gain much power compared to that of Tparsi. Moreover, Tparsi takes into account the pattern of the data that is consistent with linkage and linkage disequilibrium. As the number of alleles at the marker locus increases, Tparsi is very conservative, and can be useful even for sparse data. To illustrate the usefulness and the power of the methods proposed in this paper, we analyze the chromosome 6 data of the Oxford asthma data, Genetic Analysis Workshop 12.
Trend Tests for Case-Control Studies of Genetic Markers: Power, Sample Size and Robustness
Authors: Freidlin Boris , Zheng Gang , Li Zhaohai , Gastwirth Joseph L.
Published: April 2003

The Cochran-Armitage trend test is commonly used as a genotype-based test for candidate gene association. Corresponding to each underlying genetic model there is a particular set of scores assigned to the genotypes that maximizes its power. When the variance of the test statistic is known, the formulas for approximate power and associated sample size are readily obtained. In practice, however, the variance of the test statistic needs to be estimated. We present formulas for the required sample size to achieve a prespecified power that account for the need to estimate the variance of the test statistic. When the underlying genetic model is unknown one can incur a substantial loss of power when a test suitable for one mode of inheritance is used where another mode is the true one. Thus, tests having good power properties relative to the optimal tests for each model are useful. These tests are called efficiency robust and we study two of them: the maximin efficiency robust test is a linear combination of the standardized optimal tests that has high efficiency and the MAX test, the maximum of the standardized optimal tests. Simulation results of the robustness of these two tests indicate that the more computationally involved MAX test is preferable.
Investigating the Coordinated Functioning of Multifaceted Cultural Practices in Human Development
Authors: Rogoff Barbara , Angelillo Cathy
Published: April 2003

We argue for the importance of keeping a focus on the dynamically coordinated functioning of multifaceted cultural practices for investigating cultural aspects of human development. Although some research projects benefit from focusing on specific aspects of cultural functioning, it should be with the recognition that segmentation into ''variables’ is for the sake of analysis rather than assumed necessarily to reflect the reality of the phenomena that we study. The portfolio of research on cultural aspects of human development needs to include analyses that focus more broadly on the historically changing constellation of cultural practices in which individuals participate, even as other studies examine specific aspects as if they were freestanding variables. We illustrate this argument with research suggesting that middle-class European American adults’ ways of interacting with children can be illuminated by seeing their practices as an aspect of a somewhat coordinated historical, cultural system. Cultural analyses that focus on coordinated, multifaceted practices can help us understand human development in the context of people’s participation in pervasive cultural institutions such as schooling and societal changes such as industrialization. For the research portfolio to develop a comprehensive approach to investigating coordinated patterns in cultural aspects of human development, we need a more open-minded respect for a variety of approaches to cultural research than is sometimes found within disciplines.
On the Study of Culture in Developmental Science
Authors: van de Vijver Fons J.R. , Poortinga Ype H.
Published: April 2003

Cross-cultural developmental research faces the daunting task of studying the relationship of development and cultural context. The main argument of this article is that a variety of approaches is needed rather than one single perspective to make progress with this task. We illustrate how qualitative and quantitative research can be seen as complementary rather than mutually exclusive. We present four models, following Cole, that range from simple main effects to dynamic interaction models and argue that the debate about superiority of any one model is counterproductive; when applicable a more simple model is to be preferred. Thereafter a taxonomy of psychological domains is proposed (physiological, perceptual, cognitive, personality, and social aspects) that has a bearing on the choice of model. The final section describes some issues (and pseudoissues) of cross-cultural developmental science, such as the dichotomy between molar and molecular approaches, and the presumed need to maximize the understanding of cultural context in all research.
Renoprotective Effect of Small Doses of Losartan and Enalapril in Patients with Primary Glomerulonephritis
Authors: Tylicki Leszek , Rutkowski Przemyslaw , Renke Marcin , Rutkowski Boleslaw
Published: April 2003

Background: The renin-angiotensin system is thought to be involved in progression of chronic renal diseases of both diabetic and nondiabetic origin. It is confirmed that angiotensin-converting enzyme inhibitors reduce urinary protein excretion (UPE) and attenuate the development of renal injury. The angiotensin II receptor blockers are an alternative class of drugs inhibiting the renin-angiotensin system activity with preliminarily confirmed renoprotective activity. However, there is lack of data concerning renoprotective action of very small doses of these drugs. Methods: Prospective, randomized, 3-month study of the effects of losartan 25 mg (n = 17) vs. enalapril 10 mg (n = 17) vs. combination of losartan 25 mg and enalapril 10 mg (n = 15) on proteinuria, kidney function and metabolic profile in 51 patients with biopsy proven chronic glomerulonephritis with normal or slightly declined kidney function [creatinine clearance (CRCL) between 36 and 93 ml/min] was performed. Clinical evaluation and laboratory tests were estimated before treatment (basal), during the first week and after 3 months of therapy. Results: Both, monotherpy with losartan and enalapril significantly reduced proteinuria by 25.35 and 45.07%, respectively. There was no significant difference between groups. Combined therapy induced a more remarkable reduction of proteinuria (65.96%) than either of the drugs administered alone. This antiproteinuric effect was significantly more pronounced only in comparison with the losartan group (p = 0.009). Decreasing of blood pressure was most pronounced in the combined group. In all groups, no correlation between fall of UPE and reducing the systolic or diastolic blood pressure was found. Significant decline in CRCL was observed with enalapril treatment just after 1 week of therapy (p = 0.039) and at the end of observation (p = 0.043). CRCL remained stable in losartan-treated subjects. No changes in serum creatinine level, metabolic profile and sodium excretion were observed during therapy in studied groups. Conclusions: These results indicated that even very small doses of losartan and enalapril reduce proteinuria in patients with primary glomerulonephritis. Combination of these drugs could cause significantly greater antiproteinuric effect than either of the agents in monotherapy. It is likely that the treatment with losartan, compared to enalapril, is associated with less risk of acute fall of glomerular filtration at the beginning of therapy.
Intraindividual Reproducibility of Postprandial Hypotension
Authors: Puisieux François , Court Dominique , Baheu Eddy , Dipompeo Christophe , Bulckaen Hélène , Dewailly Philippe
Published: April 2003

Background: Postprandial hypotension (PPH) is increasingly recognized as a common cause of falls and syncopes in the elderly. The diagnosis of PPH is based on the measurement of meal-induced blood pressure (BP) changes. Although the problem of intraindividual reproducibility of PPH is of clinical importance, it has not been extensively studied. Objective:  To assess the intraindividual reproducibility of PPH. Methods: 50 patients (42 women and 8 males, 83 ± 8 years) were included in the study. To evaluate PPH, we measured the BP before and every 15 min for 2 h after the start of a standardized mixed meal. The PPH was defined as a decrease in systolic BP of 20 mm Hg or more. Three sets of BP were obtained for each subject on 2 successive days: (1) between 08.00 and 10.00 h and (2) between 16.00 and 18.00 h on the 1st day and (3) between 08.00 and 10.00 h on the 2nd day. Results: 32 participants (64%) experienced PPH on at least one test. Among them, 19 (38%) had PPH on the first test, 16 (32%) had PPH on the second test, and 21 (42%) had PPH on the third test. The intraindividual reproducibility of PPH was good when the results of the two morning tests were compared together (kappa coefficient = 0.6), but was low when the morning test results were compared with the afternoon test results of the 1st day (kappa coefficient = 0.1). Conclusions: Because of the good reproducibility of postprandial BP changes, we conclude that the diagnosis of PPH may be based on a single standardized test. However, the test must be performed under circumstances (time of the meal, medications) similar to those in which the symptoms occurred.
Use of Fluoroscopy-Guided Wire Manipulation and/or Laparoscopic Surgery in the Repair of Malfunctioning Peritoneal Dialysis Catheters
Authors: Kim Hee Jin , Lee Tae Won , Ihm Chun Gyoo , Kim Myung Jae
Published: April 2003

Background: Peritoneal catheter is the lifeline for the continuous ambulatory peritoneal dialysis (CAPD) patients. Over the years, obstruction or displacement of the CAPD catheter has been one of the common complications of CAPD. Fluoroscopy-guided wire manipulation or laparoscopic surgery has been developed to manage outflow obstruction. We analyzed the catheter outcome of fluoroscopy-guided wire manipulation or laparoscopic surgery to determine the ultimate benefit of these procedures. Methods: From June 1996 to August 2000, catheter complications were manipulated in 24 patients. Eleven (46%) of these patients were initially managed by guide wire under fluoroscopic control. The remaining 13 (54%) patients were manipulated by laparoscopic surgery. A successful outcome was defined as maintained normal peritoneal catheter function at 30 days after the manipulations. Among the catheters manipulated, 18 (75%) were inserted by nephrologist and 6 (25%) by surgeons at the initiation of CAPD. Tenckhoff double-cuff peritoneal catheters were inserted to all patients. Results: The time elapsed between catheter insertion and manipulation varied from 1 to 60 days with a mean of 11 days. The primary causes of catheter malfunction were kinking in 1 case, omental wrapping with adhesions in 9 cases, and catheter displacements in the remaining 14 cases. Thirty-day catheter function was achieved in 50% (12/24) of initial catheter manipulations, with guide wire under fluoroscopic control (46%, 5/11) and laparoscopic surgery (54%, 7/13). Overall success rate of repeated manipulation was 71% (17 of 24). Conclusion: The successful outcome in repairing of the malfunctioning CAPD catheters could be increased by the combination of fluoroscopy-guided wire manipulation and laparoscopic surgery.
Therapeutic Approach to Hyponatremia
Authors: Han Dae-Suk , Cho Byoung-Soo
Published: April 2003

Hyponatremia is a relatively common disorder occurring in up to 6% of hospitalized patients and can occur through any mechanism that produces a relative excess of body water to body sodium. Although most hyponatremia patients are asymptomatic, severe symptomatic hyponatremia is a medical emergency that may lead to cerebral edema, tentorial herniation and death. More aggressive therapy is indicated in these patients. However, in some patients, the treatment itself may result in central nervous system demyelination that may be associated with permanent neurologic sequelae. The therapeutic strategy that should guide optimal treatment of hyponatremia requires attention to the following four factors: the patient’s volume status, the presence or absence of symptoms, duration of hypo-osmolality, and the presence or absence of risk factors for the development of neurologic complication. An initial categorization according to the clinical ECF volume status of the patient will allow a determination of the appropriate initial therapy in the majority of cases. The importance of duration of hyponatremia and the presence or absence of symptoms relates to how well the brain has adapted to the hyponatremia. The severity of hyponatremia is also an important consideration because osmotic demyelination is rarely seen in patients with the initial serum sodium greater than 120 mEq/l. Clinical surveys have identified subgroups of patients at greatest risk for developing neurologic complication of hyponatremia. Optimal therapy of these patients must consider balancing the risks of hyponatremia against the risks of correction for each patient individually. Although individual variability in response to treatment is considerable, consensus guidelines for treating hyponatremic patients allow a rational and safe therapeutic approach to minimize the neurologic complications.
Smoking Is Associated with Alterations of Blood Thiol-Group Related Antioxidants in Patients on Hemodialysis
Authors: Wang Nai-Phon , Lim Paik-Seong , Chen Tsen-Tsai , Thien Lee-Moi , Wang Tsung-Hsiu , Hsu Wei-Ming
Published: April 2003

Cardiovascular disease is the major complication and cause of mortality in the dialysis population, accounting for about 40% of deaths. Oxidative stress has been strongly implicated in the pathogenesis of these events. As patients in end-stage renal disease (ESRD) are in a state of elevated free radical activity, the aim of the present study was to investigate the negative impact of smoking in 45 male hemodialysis (HD) patients. These patients, who were 40–85 years of age (mean age 60.9 ± 13.3 years), had been on hemodialysis for at least 12 months before participating in this study. Fasting blood sampling for serum lipid, albumin, urate, lipid peroxides total blood glutathione (tGSH), non-GSH free sulfhydryl compounds (non-GSH fSH), plasma glutathione peroxidase (pGSHPx), erythrocytes glutathione peroxidase (rGSHPx), plasma glutathione S-transferase (pGST) and erythrocytes glutathione S-transferase (rGST) were determined. Our study showed that the plasma malonyldialdehyde (MDA) concentration was significantly higher in HD patients who smoked than in those who were non- smokers (1.99 ± 0.53 vs. 1.55 ± 0.46 nmol/ml, p = 0.008). No association was found between levels of MDA in smokers and BMI, serum cholesterol and triglycerides and smoking index. We also found that the circulating plasma levels of tGSH and non-GSH fSH was lower in the HD patients who smoked (tGSH 164.9 ± 41.5 vs. 203.4 ± 45.3 µg/ml; fSH 271.1 ± 55.8 vs. 308.8 ± 46.7 µg/ml; p < 0.05 and p < 0.001, respectively). There were no significant differences in the plasma levels of uric acid, pGSHPx, rGSHPx, pGST, rGST, albumin, and age between the 2 groups. Partial correlation analysis of the plasma levels of the measured antioxidants and the smoking index revealed a negative correlation between the plasma levels of tGSH and smoking index (r = –0.62, p < 0.003). Similarly, the plasma levels of tGSH was found negatively correlated with the levels of plasma MDA (r = –0.32, p < 0.05) of the HD patients. In conclusion, our data suggest that cigarette smoking has a negative impact on plasma-circulating products of lipid peroxidation in HD patients. The lower blood levels of the tGSH and non-GSH fSH in HD patients who smoked suggests that these patients may be more susceptible to oxidative damage caused by smoking.
Interleukin 4 Co-Stimulates the PDGF-BB- and bFGF-Mediated Proliferation of Mesangial Cells and Myofibroblasts
Authors: Sommer M. , Eismann U. , Gerth J. , Stein G.
Published: April 2003

Background: Although many mediators involved in the pathogenesis of fibrosis are known, its precise mechanism is still unknown. In vitro experiments may contribute to the recognition of cellular changes which also take place during fibrosis. Methods: Renal tubular epithelial cells (EPC), mesangial cells (MC) and glomerular endothelial cells (GEDC) as well as endothelial cells (EDC) and myofibroblasts (MF) from cattle were isolated to measure the proliferation and protein synthesis in the presence of individual and combined cytokines/growth factors in cell cultures. Results: Cytokines stimulating or permitting the proliferation of myofibroblast-like cells (MFLC) (MC and MF), caused damage of endothelial cells (EDC, GEDC), whereas EPC were stable. The proliferation of MFLC was strongly stimulated by PDGF-BB and bFGF and elevated more than twofold in the presence of interleukin 4 (IL-4), but IL-4 alone had no effect. Furthermore, the proliferation of transdifferentiated endothelial cells (TEC), obtained by incubation of EDC with TNFα and bFGF, was stimulated with both PDGF-BB/IL-4 and bFGF/IL-4 in the same way and proved to be stable with respect to TNFα. Conclusion: Interleukin 4 co-stimulates the PDGF-BB- and bFGF-mediated proliferation of MC, MF, and TEC. TNFα does not inhibit the proliferation of extracellular matrix-synthesizing cells, but has an inhibitory or even toxic effect on EDC and GEDC. It may be concluded that cytokines released in inflamed renal tissue influence tubulointerstitial cells in different ways, resulting in progressive tissue damage and fibrosis in which the EDC would be the most sensitive cells. Thus, we speculate that microvascular injury in these areas leads to ischemia and malnutrition of tubular EPC and may be responsible for ongoing tubular damage and resulting renal interstitial fibrosis.
Is Aortic Valve Replacement with Bileaflet Prostheses Still Contraindicated in the Elderly?
Authors: De Feo Marisa , Renzulli Attilio , Vicchio Mariano , Della Corte Alessandro , Onorati Francesco , Cotrufo Maurizio
Published: April 2003

Background: Prolonged survival in the Western world has increased the number of elderly patients referred for open-heart surgery during the last decade. Aortic valve disease is the most common heart valve disease in aged patients. Which aortic valve substitute is best employed in the elderly is still a debated matter. The main concern is about the thromboembolic and hemorrhagic risks related to mechanical valves and anticoagulation. Objective: The study aimed at reviewing clinical results after isolated aortic valve replacement with bileaflet prostheses in patients over 70 years and at retrospectively comparing them with those of a group of otherwise comparable patients under 50 years of age who underwent isolated aortic valve replacement with a mechanical device. Methods: The study population included 118 consecutive elderly patients (group A) operated on between January 1988 and January 1999 and 122 young patients (group B) who underwent aortic valve replacement during the same time period. Patients with associated coronary artery disease, mitral stenosis or regurgitation, type A aortic dissection, and infective endocarditis were excluded from the study. Preoperative clinical data, early and late postoperative mortality, all valve-related complications, and all data concerning the anticoagulation status – including the mean international normalized ratio (INR) and the mean time interval between each INR assay – were compared between the two groups. Results: The hospital mortality was significantly lower in group B (2.45%) than in group A (9.3%; p = 0.022). The mean follow-up period was 50.98 ± 2.23 months. The 12-year actuarial survival was significantly lower (69.6 ± 0.08%) in group A than in group B (94.4 ± 0.02%; p < 0.001). No significant difference was found in terms of valve-related and anticoagulation-related complication rates and actuarial freedom as well as mean interval between consecutive INR checks (p = 0.219) and mean INR value (p = 0.914). Conclusions: Bileaflet prostheses in elderly patients can achieve excellent early and late clinical results, with a low incidence of anticoagulation-related complications and an extremely low risk of a reoperation. Older age can no longer be considered a contraindication to bileaflet prosthesis implantation in the aortic position.
Effect of Mannitol on Helicobacter pylori-Induced Cyclooxygenase-2 Expression in Gastric Epithelial AGS Cells
Authors: Kim Hyeyoung , Seo Jeong Yeon , Kim Kyung Hwan
Published: April 2003

Oxygen radicals have been considered to be important regulatory molecules in Helicobacter pylori-induced gastric ulceration and carcinogenesis. H. pylori-induced inflammation has been shown to be associated with cyclooxygenase-2 (COX-2) expression in experimental animals and human patients. This study aimed to determine if H. pylori produces oxygen radicals and induces COX-2 expression in gastric epithelial cells. A further aim was to resolve whether or not the H. pylori-induced COX-2 expression could be inhibited by mannitol, a known hydroxyl radical scavenger, and superoxide dismutase (SOD), an antioxidant enzyme, which was used as a positive control. A human gastric epithelial cell line, AGS, treated with or without mannitol or SOD, was incubated in the presence or absence of H. pylori. mRNA expression and protein levels for COX-2 were determined by Northern blot and Western blot analysis, respectively. Levels of the COX-2 products, 6-keto-prostaglandin F1α (6-keto-PGF1α) and thromboxane B2 (TXB2) and H2O2 were measured in the medium. The results showed that H. pylori induced H2O2 production, COX-2 mRNA and protein expression and increased the levels of 6-keto-PGF1α and TXB2. The H. pylori-induced COX-2 expression and the increase in the COX-2 products were inhibited by both mannitol and SOD. The inhibitory effect of mannitol on H. pylori-induced COX-2 expression suggests the possible involvement of oxygen radicals in the transcriptional regulation of the inflammatory mediators in gastric epithelial cells.
OPS Imaging of Human Microcirculation: A Short Technical Report
Authors: Lindert J. , Werner J. , Redlin M. , Kuppe H. , Habazettl H. , Pries A.R.
Published: April 2003

Despite the pivotal role of microcirculation in numerous diseases, techniques for the direct assessment of human microcirculation are limited. A new approach based on orthogonal polarization spectral (OPS) imaging (Cytoscan™ microscope) allows noninvasive observation of human microcirculation in all accessible tissue surfaces. Limitations remain: application of pressure with the instrument affects blood flow, lateral movement of tissue precludes continuous investigation of a given microvascular region, and blood flow velocities above 1 mm/s cannot be measured. We addressed these problems by (a) constructing an attachment to the probe, preventing direct contact of the instrument with the observed tissue area and allowing fixation of the tissue, and (b) implementing a double-flash spatial correlation technique extending the measuring range for blood flow velocities up to ∼40 mm/s. The modified approach was tested in vitro and in vivo. Velocity readings correlated well with velocities of an external standard (r2 = 0.99, range 1.9–33.8 mm/s). Pulsatile flow patterns synchronous with heart rate with maximal velocities of about 10 mm/s could be detected in arterioles of the human sublingual mucosa. The modified instrument may prove useful to investigate the microcirculation in the context of research, diagnosis and therapy control.
Sarcomatoid Carcinoma of Urinary Bladder: Immunohistochemical Study of an Uncommon Case
Authors: Cappello Francesco , Aragona Federico , Serretta Vincenzo , Randazzo Giuseppe , Melloni Darwin
Published: April 2003

A case of sarcomatoid carcinoma of the bladder is reported herein. Immunohistochemical staining with human pancytokeratin antibody was negative, while vimentin staining was strongly positive, suggesting a diagnosis of sarcoma of the bladder. Further immunohistochemical analysis revealed positivity for AE1/AE3 cytokeratins, permitting a correct diagnosis of sarcomatoid carcinoma of the bladder. It can be difficult to distinguish between sarcomatoid carcinoma, undifferentiated carcinoma and sarcoma, particularly if the biopsy specimens are of small size. In rare cases, sarcomatoid tumors may express epithelial markers different from those revealed by human pancytokeratin staining.
Morphological Changes and Nuclear Pore Clustering during Nuclear Degradation in Differentiating Bovine Lens Fibre Cells
Authors: Dahm Ralf , Prescott Alan R.
Published: April 2003

The programmed degradation of organelles is a characteristic feature of lens fibre cell differentiation. Due to the large number of similarities between the programmed organelle loss during lens development and the changes to organelles in apoptosis, lens cell differentiation has been suggested to share a common basis with programmed cell death. This study was aimed at characterising the morphological changes to the nucleus during cellular differentiation in the bovine lens at the ultrastructural level. Progressive shrinkage of the nucleus is accompanied by clumping and marginalisation of the chromatin to the nuclear periphery. Additionally, the fate of another key component of the nuclear envelope – the nuclear pore complexes – was followed. In parallel to the shrinkage of the nucleus, the nuclear pores progressively cluster into large aggregates that associate with the condensed DNA. These observations in differentiating lens fibres mirror the situation in cells undergoing apoptosis and thus provide additional data supporting a common basis between the two processes.
Gastric Damage Induced by Subchronic Administration of Preferential Cyclooxygenase-1 and Cyclooxygenase-2 Inhibitors in Rats
Authors: Villegas Isabel , Alarcón de la Lastra Catalina , Martín M. José , Motilva Virginia , La Casa García Carmen
Published: April 2003

Nonsteroidal anti-inflammatory drugs (NSAIDs) are well known to induce gastrointestinal damage including bleeding, ulceration and perforation in humans and animals. The aim of this study was to compare the effects of two oxicams, preferential cyclooxygenase (COX)-1 or COX-2 inhibitors, on both gastric mucosa and some biological parameters (hematological, hepatic and renal) after subchronic administration (14 and 28 days) in rats. Neutrophil infiltration was also assessed. Equipotent doses of meloxicam (3.75 and 7.5 mg/kg) and piroxicam (5 and 10 mg/kg) were administered. Both drugs dose-dependently caused multiple gastric erosions and hemorrhage in rats after 14 and 28 days of administration. Treatment with meloxicam led to a higher gastric damage than with piroxicam on day 14 although these results were not significant. The levels of myeloperoxidase activity (as an index of neutrophil infiltration) were not changed compared with control after drug treatment. All the hematological parameters obtained after drugs administration for 14 and 28 days were in the range of normal values, and a significant increase in platelet levels could be observed in the group treated with 5 mg/kg of piroxicam for 14 days. Aspartate aminotransferase (AST or GOT) increased significantly after 14 days, but after 28 days the values returned to normality. Creatinine and urea did not undergo significant changes except for the piroxicam 14-day 5 mg/kg group, in which uremia increased significantly over normal values. In conclusion, our results show that meloxicam, a preferential COX-2 inhibitor, causes rates of gastric lesion comparable to those seen with traditional NSAIDs, without inducing important changes in biological parameters.
Effects of SK-1080 on Intimal Thickening and Impaired Vascular Relaxation after Ballon Injury in Rats
Authors: Lee Byung Ho , Yoo Sung-Eun , Shin Hwa Sup
Published: April 2003

We investigated the effects of SK-1080, a novel angiotensin AT1 receptor antagonist, on neointimal proliferation in the rat carotid artery after balloon injury, together with its effects on the impaired endothelium-dependent vascular relaxation. SK-1080 (0.3 and 1.0 mg/kg/day) was orally administered in balloon-injured rats for 21 days (from 6 days before to 14 days after balloon injury). SK-1080 (1 mg/kg) exerted significant effects on three important parameters associated with the intimal thickening induced by balloon injury (50.0% reduction in neointimal area, 42.7% reduction in stenosis ratio and 69.1% increase in lumen/total area ratio). Acetylcholine-induced relaxation was significantly reduced in the balloon-injured carotid arteries (64.0 ± 9.1%), and this impairment of acetylcholine-induced relaxation was significantly restored by SK-1080 (maximal relaxation: 87.1 ± 6.5 and 88.6 ± 1.9% at 0.3 and 1.0 mg/kg, respectively, p < 0.05). However, the endothelial-independent, sodium nitroprusside-induced relaxation was clearly demonstrated and did not differ in carotid arteries from all treatment groups. Furthermore, acetylcholine-induced relaxation was completely inhibited by L-NAME but not by indomethacin. SK-1080 caused a slight hypotension 1 day before balloon injury (8.7%), which gradually returned to the baseline 6 and 13 days after balloon injury. These results suggest that SK-1080 may have therapeutic potential for the treatment of vascular diseases such as restenosis and atherosclerosis.
Partial Pancreatic Head Resection for Intraductal Papillary Mucinous Carcinoma Originating in a Branch of the Duct of Santorini
Authors: Nakagohri T. , Konishi M. , Inoue K. , Izuishi K. , Kinoshita T.
Published: April 2003

We report partial pancreatic head resection of intraductal papillary mucinous carcinoma originating in a branch of the duct of Santorini. The tumor was located in the ventral part of pancreatic head at a distance from the Wirsung duct. Magnetic resonance cholangiopancreatography accurately showed the communication between the duct of Santorini and the cystic tumor, and was useful for determining the part of the pancreas to be resected. Both the duct of Wirsung and the duct of Santorini were preserved. Partial pancreatic head resection would play an important role in surgical management of low-grade malignant neoplasm.
Abdominal Compartment Syndrome in Severe Acute Pancreatitis: An Indication for a Decompressing Laparotomy?
Authors: Gecelter Gary , Fahoum Bashar , Gardezi Syed , Schein Moshe
Published: April 2003

Background: The currently prevailing paradigm calls for non-operative management of severe acute pancreatitis for as long as there is no evidence of infection. Our purpose in presenting this anecdotal experience is to propose that there is a subset of patients who may need a laparotomy in the absence of infection in order to decompress a clinically significant abdominal compartment syndrome (ACS), which is associated with the acute pancreatitis. Methods: We present our recent experience with three patients suffering from severe acute pancreatitis. The three developed intra-abdominal hypertension (IAHT) and clinical ACS, which necessitated abdominal decompression and a laparostomy. One patient survived. Conclusions: The notion that patients with severe acute pancreatitis may develop ACS, which necessitate emergency abdominal decompression, has been ignored by current surgical literature. Only increased awareness to the syndrome of IAHT-ACS in acute pancreatitis and transvesical measurement of intra-abdominal pressure will reveal its prevalence and significance.