Search

Donnan dialysis with ion-exchange membranes was investigated experimentally. The equation derived theoretically in the previous paper was fitted to the results of a Donnan dialytic experiment, and the diffusion coefficients of various kinds of ions and in various kinds of ion-exchange membranes were obtained. The flux of monovalent ions in Donnan dialysis was much larger than that of bivalent ions. Thus, monovalent drive ions are the best kind of drive ions to employ. It was found that the ratio of the diffusion coefficient in the ion-exchange membrane to that in the solution remained constant at 70 for monovalent feed and drive ions except for H+ ions, and at 175 for bivalent feed and drive ions. It became apparent that the fundamental equation derived from Fick's equation and no electric current might be used for Donnan dialysis instead of the Nernst-Planck equation.

The transfer of ions through ion-exchange membranes was investigated theoretically for Donnan dialysis. By applying Fick's equation and no electric current to the flux through the ion-exchange membrane on Donnan dialysis, and by changing the valences of feed and drive ions, three kinds of equations were derived: 1) feed ions and drive ions are of equal valence, 2) feed ions are monovalent and drive ions are bivalent, and 3) feed ions are bivalent and drive ions are monovalent. The equations were evaluated by use of a computer by the Runge-Kutta method. The relation between the valence of ions and the characteristic coefficients of the membrane became apparent from the calculated results.

An equation for estimating the limiting current density (LCD) in the electrodialytic equipment with spacers is derived by using the equation of the flow distribution and by assuming that the eddy diffusivity caused by the spacer is proportional to Re. The empirical constants of the eddy diffusivity in the equation were determined by measurement of LCD using spacers, electrolytes, feed concentrations, operating temperatures, and flow velocities. The results obtained show that LCD in the electrodialysis can be estimated from the equation derived here.

Abstract: The role of transferrin in iron absorption by the duodenal mucosa in rats with iron deficiency and controls was evaluated immunohistochemically. Ferric iron was administered to each rat using a metallic gastric tube. Transferrin was stained by an immunoperoxidase method and iron with Prussian blue in the same duodenal sections and observed by light microscopy. The localization of transferrin differed from that of ferric iron both in rats with iron deficiency and in controls. In iron-deficient rats, transferrin was weakly stained after iron administration but was strongly stained after saline administration. In contrast, in controls, transferrin was weakly stained after saline administration but was strongly stained after iron administration. By electron microscopy, x-ray energy spectrometric analysis of the transferrin-positive areas showed no iron peak. In iron-deficient rats, accumulation of electron-dense transferrinnegative microgranules was observed in some of the duodenal columnar epithelium. X-ray energy spectrometric analysis of this area revealed iron, indicating iron absorption. These results suggest that mucosal transferrin does not act as a shuttle protein in iron absorption via the rat duodenal columnar epithelium, and the function of this protein may be to inform the absorptive cells of the iron status of the body as observed in other organs.

The influence of "space" in the ion-exchange compartment (IEC) on limiting current density (LCD) during electrodialysis was investigated. A general equation to estimate LCD was derived for three types of electrodialytic equipment: 1) with the IEC tilled with spacers, 2) without spacers, and 3) with spacers and space. The theoretical values of LCD calculated from the equation were in good agreement with the experimental values obtained by varying the space thickness and employing various kinds of spacers; it follows that the value of LCD in all three types of electrodialytic equipment can be estimated from the general equation derived here.

One hundred fifty-two patients with esophageal varices underwent a total of 485 injection sclerotherapy procedures (mean, 3.2 times per each case). During 5 years of observation, 20 cases (13.2%) died following injection sclerotherapy. The 3-year survival rates, based on the Kaplan-Meier method, were 42% for emergency cases, 75% for elective cases and 90% for prophylactic cases. Significant differences (P<0.05) by the generalized Wilcoxon test were observed in the survival rates between emergency cases and prophylactic cases, and also between elective cases and prophylactic cases. Two cases (8.6%) of failure to control acute hemostasis were experienced. Twenty cases of bleeding after sclerotherapy were experienced, and 8 died of bleeding. The three-year bleeding rate according to the Kaplan-Meier method was 59% for emergency cases, 25% for elective cases and 7% for prophylatic cases. A significant difference (P<0.05) by the generalized Wilcoxon test was observed in the bleeding rate between elective cases and prophylactic cases. Non-bleeding rate (100%-bleeding rate) after sclerotherapy showed almost the same values as the survival rate. These results indicate that upper digestive tract hemorrhage influences the prognosis of patients after sclerotherapy.

The applicability of a new immunological fecal occult blood test in which hemoglobin (Hb) and transferrin (Tf) are simultaneously assayed was evaluated. The mean absorbance and standard deviation (510/630 nm) obtained by this test was 0.840±0.805 in 51 fecal samples from patients with colon cancer, 0.248±0.305 in 95 samples from patients with colon polyps, and 0.104±0.053 in 110 samples from control patients; these values differed significantly (P<0.005). Hb and Tf concentrations were separately determined in the same fecal sampels, and qualitative evaluation was performed with a cutoff value of 5.1µg/g feces for Hb and 0.4µg/g feces for Tf. Hb or Tf was positive in 41 of the 51 samples in the colon cancer group, 33 of the 95 in the colon polyp group, and 3 of the 110 in the control group. Qualitative analysis of the values obtained by the combination assay of Hb and Tf with a cutoff value of 0.200 revealed positive rates of 41/51 in the colon cancer gorup, 33/95 in the colon polyp group, and 4/110 in the control group. These results sugest the usefulness of a combination assay of Hb and Tf as a fecal occult blood test.

AbstractPartition coefficients of some cations between cation exchange membrane and solution were measured. The reciprocals of the partition coefficients were plotted against the corresponding: dimensionless concentrations of ions in solution. The relations obtained experimentally for monovalent-monovalent and monovalent-bivalent ions systems were in agreement with the respective theoretical equations. For the monovalent-monovalent exchange the relation was linear. While in the monovalent-bivalent case it was non linear. We proposed an empirically obtained linear relation for the monovalent-bivalent system. Therefore, the dependence of the reciprocal of partition coefficients on the dimensionless concentration of solution can be represented by a linear relation for both systems.

Background:Patients with dysphagia have alternative treatments;either nasogastric (NG)tube or percutaneous endoscopic gastrostomy (PEG).Quality of lives of these patients are often dependent on these treatments.Previously,a short term assessment for the comparison between these two treatments has been reported.And PEG had some advantages upon NG tube.However,these treatments last long,and so they need longterm assessment.In the present study, we perform long-term comparison including nutrition,complications,and long term survival. Materials and Method:Patients with dysphagia which are not indicated for curative therapy were eligible for the study. They were randomly divided into two groups.Group A were treated with NG tube feeding.Group B were treated with PEG. Results:Sixty seven patients were included in the study.from January 1994 through November 1999.Of 67 patients,40 are assigned to be enrolled in group A,and the other 27 are in group B.The two groups were comparable at baseline for all demographic and baseline characteristics. There were no significant differences in nutrition between Group A and Group B as for albumin (3.3vs3.4), cholesterol (175vs166), Hb (11.7vs10.7).As for the incidences of complications are as follows. Incidence of esophageal disorders is higher in group A than in group B (43%vs19%;p<0.05). The other complications like anemia,tube dislodgment,aspiration pneumonia(55%vs37%;p<0.01) are higher in Group A than Group B.Mean life expectancy is longer in Group B than Group A(11.1+/-3.3months vs 8.1+/-3.4months, p<0.05) Coclusion:Long term observation revealed that PEG feeding is a safer and long-standing nutritional method for patients with dysphagia than NG tube feeding.

Background:We have carried on percutaneous endoscopic gastrostomy (PEG) to the 27 dysphagic patients of our hospital these 4 years.Moreover in some cases we replaced the gastro-button(G.button) system (C.R.BARD,Inc.) following PEG.We report the advantages of this system.We used the “pull” method of PEG technique. Materials and Method:A total of 27 patients with impaired swallowing were consulted for PEG placement these 4 years. (age:50-92 yrs.,mean age:70yrs.) male:7,female: 20. The previous 9 cases were fed by PEG for the early 2 years. In the following 2 years we replaced G.button system for the other 18 cases instead of PEG feeding. The underlying diseases of PEG group were cerebrovascular diseases (CVD):4,dementia:2, Parkinson's disease:1, neoplasm:1 other:1,age:50-91 yrs. mean:70.5 yrs.The underlying diseases of G.button group were CVD:14,Alzheimer's dis.:2,brain tumor:1, other:1,age58-92 yrs. ,mean:73.6 yrs.,male:3,female:15. Results:The complications of PEG group were some esophagitis (LA-classification; grade0:5, gradeA:1, gradeB:1,gradeC:1,gradeD:1),aspiration pneumonia:4,The durations of PEG were from 1.5 months(M) to 10M and mean is 3.5months. Five of 9 cases were dead within 1 year since PEG placement.The other 4 are still alive.(mean survival:2.5M)Those of G.button group were a few esophagitis(LA classification;grade 0:14,grade A:2,gradeC:2) some gastric or duodenal ulcers(n=4),aspiration pneumonia(n=8) Seven of G.button group died from 3M to 22.5M since G.button replacement.(mean duration is 8M) Eleven of G.button are still alive.The durations of G.button group are from 0.5M to 28M ,mean is 11M.Two cases(1 of NG and 1 of PEG)were taken care of at home.Moreover,G.button is also recommended from an aesthetic point of view. This G.button system may be used more and more as a home nutritional support in the future. Conclusion:This study indicates that Gastro-button system would rather be recommended as a long-term nutritional support especially at home than PEG.