Substitution of acetic acid for hydrochloric acid in the bicarbonate buffered dialysate

In a multicenter study including 5 dialysis units, blood acetate changes during 4 h dialysis sessions in 141 patients treated with a 4 mM acetate-containing bicarbonate dialysate (ABD) were evaluated and compared to the values of 114 patients using an acetate-free bicarbonate dialysate (AFD). Acetate-free bicarbonate dialysate was delivered by a dialysis machine from the mixing with water for dialysis of a 1/26.2 bicarbonate concentrate, and a 1/35 acid-concentrate in which acetic acid was substituted for hydrochloric acid (Soludia, Fourquevaux, France). This new type of dialysate was routinely in use for 3 years on average (range, from 2 to 5 years). All patients fasted before and during dialysis. Blood samples were withdrawn at the start and at the end of dialysis sessions. The acetate plasma concentration was determined using the acetyl-CoA synthetase enzymatic method (Boehringer, Manheim, Germany). In patients treated with ABD whose predialysis blood acetate levels were in the physiologic range of < or = 100 microM (n = 113), the acetate plasma concentration increased from a predialysis mean value of 22+/-3 microM to a postdialysis mean value of 222+/-11 microM in 88 patients (78% of patients) whereas the acetate plasma concentration changes remained in the range of physiologic values from 21+/-6 to 58+/-7 microM in the other 25 patients. In contrast, patients treated with AFD whose predialysis blood acetate levels were in the physiologic range (n = 108), acetate plasma concentration increased from a predialysis mean value of 49+/-6 microM to 160+/-19 microM in only 13 patients (12% of patients) whereas acetate plasma concentration changes remained in the range of physiologic values of 23+/-2 to 41+/-3 microM in most of the patients of this group. In this study, a significant number of patients, whether receiving standard or acetate-free bicarbonate dialysates, exhibited an extremely high acetate plasma concentration at the start of the dialysis session. Hyperacetatemia was controlled with AFD in patients whose predialysis acetate plasma concentration of 316+/-82 decreased to 55 +/-23 microM (n = 6) at the end of the dialysis session whereas the acetate plasma concentration remained high when the predialysis concentration was 580+/-76 microM, with a postdialysis concentration of 233+/-39 microM (n = 28). It is concluded that in patients whose predialysis blood acetate levels were in the physiologic range, acetate-containing bicarbonate dialysate induces hyperacetatemia whereas postdialysis blood acetate remains in the normal range in such dialysis patients treated with acetate-free dialysate. Chronic hyperacetatemia, which could be found in dialysis patients, is well controlled by dialysis using an acetate-free dialysate.     

Clinical aspects of glomerulonephritis

With the help of 260 bioptically ascertained cases of glomerulonephritis clinical characteristics for individual forms of glomerulonephritis are explained. Specific laboratory findings and functional tests are correlated to the bioptic findings and their valency for the individual groups of diagnosis discussed. As a result of the investigation 99% of all cases of disease may be recognized only by the examination of the urine, taking into consideration the interference of the individual symptoms.     

Effects of dilute acetic acid on the cervical smear

BACKGROUND: Mesothelial integrity is essential for the prevention of pericardial adhesions. This study was performed to determine the effect of physical protection of the pericardium on mesothelial integrity. METHODS: A pericardial biopsy specimen was obtained at the time of pericardiotomy (0 minutes) in 10 patients undergoing a cardiac operation for the first time. The left free edge of the pericardiotomy was plicated inward to protect the mesothelium. Biopsy specimens were obtained from the protected and unprotected pericardium at 45 and 90 minutes after the start of extracorporeal circulation. Mesothelial integrity and the local inflammatory response were then assessed and graded histologically. RESULTS: The mesothelium was found to be present in the protected specimens at 0, 45, and 90 minutes, but it was found to be denuded in the unprotected specimens (p = 0.003 at 45 minutes; p = 0.004 at 90 minutes). Local inflammation was totally established in both the protected and unprotected specimens at 45 minutes. CONCLUSIONS: Physical agents appear to be the main factor that is damaging to the pericardial mesothelium, and this is an important concept to be taken into consideration when designing a method to prevent pericardial adhesions.     

Capillary electrophoretic determination of acetic acid and trifluoroacetic acid in synthetic peptide samples

Synthetic peptide samples may contain counter-ions such as acetate or trifluoroacetate as a result of their method of preparation. Furthermore, because acetic acid (HOAc) and trifluoroacetic acid (TFA) are frequently used reagents in peptide synthesis, these acids may be found in synthetic peptide samples as impurities. This paper describes a method validation to determine HOAc and TFA in synthetic peptide samples by capillary electrophoresis (CE) using an internal standard (I.S.) with indirect UV detection. Typical analytical parameters such as precision, linearity, accuracy, specificity, limit of detection and ruggedness were evaluated during the validation. In addition, the contents of HOAc and TFA in two synthetic opioid peptide samples, TIPP[psi] and Orphanin FQ, were determined using the validated method. A unique feature of the method is that it offers determination of both acids in a single assay using a common I.S. The method is very efficient because of relatively short electrophoretic migration times (typically 2 to 8 min) for the acids investigated. This paper also discusses the factors that affect precision in a CE assay.     

Effect of acetic acid bacterium on ethanol oxidation in vivo

We investigated the possible effects of acetic acid bacterium on ethanol oxidation in vivo by monitoring the blood ethanol level after injecting 5% ethanol with (treated group) or without (control group) a freeze-dried bacterial cell suspension directly into the stomach of anesthesized rats. Paired comparison t-tests of the results indicate that the blood ethanol concentration of the rats in the treated group was significantly (p < 0.07) lower than that in the control group. When measured 10 min after administering ethanol into the gullet, the concentration in the stomach of the rats that received acetic acid bacterium simultaneously with ethanol was significantly (p < 0.10) lower than that of the rats that received ethanol alone. We consider that freeze-dried cells of acetic acid bacterium oxidized ethanol in the stomach and could be effective for reducing the blood ethanol level after drinking.     

Clinical aspects of biclonal myelomas

In this study, a cohort of 109 patients with multiple myeloma were followed prospectively. Eight patients (7%) were found to have biclonal M component, an occurrence rate considerably higher than that reported in literature. Biclonal myelomas were compared with the other monoclonal variants of myeloma by a number of biologic, clinical, immunological, biochemical, roentgenological, therapeutical and prognostic parameters. Among the biclonal myeloma patients there was strong male predominance, higher frequency of patients in advanced stage of the disease, combined production of predominantly kappa light chains, hypoalbuminemia and thrombocytopenia. Their response to therapy did not differ from that of the patients with monoclonal myeloma variants. The median survival of patients with biclonal myelomas was 25 months, ranking third by shortened survival after patients with light chain and D-type myelomas.     

Cervico-mediastinal goiters. Clinical aspects

Among 660 cases of thyroid pathology diagnosed by the 2nd Institute of Clinical Surgery, Policlinico San Matteo, IRCCS, Pavia, during the period 1984 to 1993, 34 cases of cervical-mediastinal goiter were observed with an incidence of 5%. After a careful analysis of the main contributions to the study of cervical-mediastinal goiters, paying special attention to their classification, pathogenesis, methods of growth, and unique symptomatic manifestations, the authors focus on current radiological and instrumental studies, which are widely regarded as being useful for the diagnosis of the site and nature of this disease. They review the routes for aggressive surgery and appropriate techniques for the exeresis of the mediastinal mass. Having empasised the absolute indication for surgery the authors recommend quasi-total or total thyroidectomy as the elective form of surgery.     

Clinical aspects of salivary gland tumors

This paper reports on epithelial tumours arising primarily in the major and minor salivary glands. The purpose of this presentation is to summarize our experience of salivary gland tumours on the basis of a material comprising of approximately 3000 salivary gland tumours as well as a review of the literature to date. The tumours are classified according to the classification recommended by WHO 1972. The incidence, location, symptomatology, grade of malignancy and treatment of the different tumour types in this classification are reviewed. Diagnostic procedures are discussed and a scheme for surgical treatment and radiotherapy of the different types of salivary gland tumours is proposed.     

Clinical aspects of acid-base disorders]

Acid-base disorders are frequently recognized in a wide variety of clinical settings such as severe systemic hospitalized patients. The principal object is to assessment of acid-base equilibrium and to obtain an appropriate guide to therapy. The approach is centered to a systemic analysis of blood gas evaluation. To establish this complex matter is followed. Is an acid-base disorder present? Is the disorder a simple or a mixed abnormality? What is the primary cause? These evaluations should be obtained by accurate history taking, physical examination, and routine laboratory tests. In addition, the supporting analysises such as anion gap (AG) calculation, urine AG assessment, urine chloride concentration and so on are also useful for correct diagnosis. In view of the complexty and difficult expression of acid-base disorders, it is desirable that clinicians must have full knowledges of systemic approach to the blood gas analysis and its evaluation.     

Clinical aspects of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a progressive degenerative disease of upper and lower motor neurons with a prevalence of 4.3/100.000. The clinical symptoms include peripheral weakness and central spastic paresis and bulbar paralysis (weakness of mimic muscles, atrophy of the tongue, dysarthria). The prognosis leads to death within a few years. Pathogenetic factors are free O2-radicals, a disturbance of glutamate-metabolism, abnormal accumulation of neuronal proteins and autoimmunological mechanisms.     

Clinical aspects of amniotic fluid embolism

At the Clinic Obstetrics and Gynecology, Allgemeines Krankenhaus Celle, two cases of amniotic fluid embolism were observed. The first case showed the two characteristic phases of the disease (cardiopulmonary shock followed by severe disseminated intravascular coagulopathy). During the onset of the cardiorespiratory symptoms, the patient underwent cesarean section and a healthy infant was born. The mother survived. The other patient died of cardiopulmonary arrest. Cesarean section was carried out immediately. At first, the infant was heavily depressed, but further development was normal. Inspite of great advances in intensive care amniotic fluid embolism still is considered to be a very dangerous event with 86% maternal mortality.     

316L不锈钢在含氯高温醋酸溶液中的自钝化行为

研究了316L不锈钢在85℃,含0.2% KCl的60%醋酸溶液中的自钝化行为.通过测试试样的恒电流阴极极化曲线,以及恒电流阴极极化后开路电位随时间的变化曲线,提出了316L不锈钢钝化膜的结构模型.该模型认为316L不锈钢钝化膜由三层构成:最外层主要是由Fe的氧化物以及少量Cr的氧化物组成;第二层主要是Cr的氧化物,含有少量Fe,Mo和Ni的氧化物;最底层主要是Mo,Ni的氧化物和少量的Fe原子.研究发现:316L不锈钢在实验醋酸溶液中,经10mA阴极电流极化15min后钝化膜生长参数γ最大,而经0.45mA阴极电流极化30min后钝化膜生长参数γ最小;316L不锈钢在实验醋酸溶液中,经10mA阴极电流极化30min后,自钝化电位最小,而经1mA阴极电流极化15min后,自钝化电位最大.钝化膜结构模型能很好地解释316L不锈钢在实验醋酸溶液中的上述电化学行为.