Surgical options in ulcerative colitis

Five operative options are now available for treatment of ulcerative colitis: (1) proctocolectomy with ileostomy, (2) abdominal colectomy with ileostomy and retention of the rectum, (3) abdominal colectomy with ileorectal anastomosis, (4) proctocolectomy with creation of a continent stoma or conversion of a standard ileostomy after proctocolectomy to a continent stoma, and (5) restorative proctocolectomy. Each procedure has advantages and disadvantages. With careful assessment, the specific needs of each patient can best be met. In many cases a permanent stoma can be avoided. The newer procedures have not been used long enough for long-term effects to be known, and they must be offered with reservation and then only to well-informed, stable, and relatively fit and cooperative patients.     

What are the differences in body image between patients with a conventional stoma compared with those who have had a conventional stoma followed by a continent pouch?

This paper describes a qualitative study of seven patients which explored the perceptions of body image in patients with a conventional stoma, compared with those who have had a conventional stoma followed by a continent pouch. The operation of choice for patients with ulcerative colitis (the group of patients in the study) who wish to avoid permanent ileostomy is restorative proctocolectomy with ileal reservoir, more commonly known as the 'pouch' procedure. The outcome of this study, using a phenomonenological approach, reflects the problems faced by patients undergoing stoma surgery; that is, patients with a stoma, on the whole, expressed difficulties in coming to terms with an ostomy, with perceived negative feelings of body image. In contrast, patients with a continent pouch, provided they were not experiencing difficulties with the pouch, were of the opinion that such a procedure enhanced their lives over that of an ileostomy. However, in examining these patients' feelings, it was found that the majority still considered their experience traumatic. This implies that the benefits of a continent pouch were not so obvious, as body image changes of stoma surgery still had a perceived negative effect on the patients. This affected the outcome of the study so that the differences of the two groups of patients were not as significant as perceived by the writer.     

Abnormal membrane cation transport in pregnancy-induced hypertension

An abnormality of sodium handling has been suggested as one of the mechanisms responsible for the development of pregnancy-induced hypertension. We analysed the plasma and urinary concentrations, and the intraerythrocyte activities of Na and K, and the RBC membrane Na+/K+-ATPase activity of 77 hypertensive and 133 normal pregnant women. Umbilical cord blood of infants from 21 hypertensive and 28 control women was studied. The Na+/K+-ATPase activity was determined by measuring the inorganic phosphate released by incubation in a reaction medium in the presence and absence of K ions or ouabain. The intra-erythrocyte sodium and potassium activities were measured by ion-selective electrode analysis of the haemolysates, after washing the RBCs in 110 mmol/l MgCl2. We found a significant increase in intracellular sodium and a reduction in Na+/K+-ATPase activity in the hypertensive women in comparison with the control subjects during pregnancy. No difference was observed in early puerperium. Cord blood from infants of pregnancy-induced hypertensive women showed an increase in intracellular Na+ activity and a decrease in the erythrocyte membrane Na+/K+-ATPase activity in comparison with cord blood samples from control subjects. The observed abnormalities in the plasma membrane sodium transport may play a major role in the pathophysiology of pregnancy-induced hypertension.     

The continent ileostomy: a viable alternative.

The continent ileostomy is one of the alternative techniques in managing patients who require a proctocolectomy. Although previously plagued with up to 30% revisions, the continent ileostomy appears to contribute significantly to the social and psychologic well-being of these patients. Our experience suggests that improved surgical techniques make this procedure a safe and favorable alternative to the traditional Brooke ileostomy.     

Na+ gradient-dependent p-aminohippurate (PAH) transport in rat basolateral membrane vesicles

The relationship between the transmembrane Na+ gradient and p-aminohippurate (PAH) transport was examined in isolated rat basolateral membrane vesicles. A 100 mM Na+ gradient (o leads to i) accelerated the influx of 50 microM [3H]PAH whereas similar gradients of choline+, K+, or Li+ did not. The sodium effect was not due to a diffusion potential. The Na+ gradient (o leads to i) decreased the apparent Michaelis constant for PAH from 0.167 +/- 0.016 to 0.054 +/- 0.016 mM and increased the maximum flux rate from 116.00 +/- 13.50 to 427.34 +/- 98.96 pmol/mg/min. An "overshoot" of [3H]PAH influx (159 +/- 4% of the equilibrium value) could be demonstrated only in the presence of a Na+ gradient (o leads to i) plus an opposing gradient of unlabeled PAH (i leads to o). These results suggest that PAH transport and the Na+ gradient are functionally related. A model for cellular uptake of PAH by a Na+ gradient-dependent anion exchange mechanism is presented.     

Effects of an intravenous saline load on erythrocyte sodium transport in normal human subjects

The effects of a 2 litre intravenous infusion of saline (0.9% NaCl solution) over 3 h on erythrocyte transmembrane sodium transport were studied in 12 normal human subjects. After saline infusion a significant (P less than 0.01) reduction of both outward Na+,K+ pump- and Na+,K+ cotransport-mediated Na+ effluxes was observed. The Na+,Li+ countertransport rate and the passive Na+ permeability did not change. The incubation of the subjects' erythrocytes, obtained on a separate occasion, with their own plasma taken after the saline infusion, induced an inhibition of both Na+,K+ pump and Na+,K+ cotransport outward sodium fluxes. The percentage decrease after incubation was closely correlated with the percentage reduction induced by the saline infusion in vivo (r = 0.93 for the pump and r = 0.96 for cotransport; P less than 0.01). These data suggest that extracellular fluid volume expansion affects the release of circulating factors modulating sodium transport by the Na+,K+ pump and by Na+,K+ cotransport.     

Effect of changes in dietary sodium on active electrolyte transport by erythrocytes at different stages of human pregnancy

1. Active electrolyte transport was examined in erythrocytes from women in the second and third trimesters of pregnancy and post partum, and compared with that in ovulating women. 2. There was a significant reduction in intracellular sodium ([Na]i) and increase in intracellular potassium ([K]i) in pregnancy with a return towards normal values in the post-partum period. 3. Maximum specific ouabain binding [number of Na+,K+-adenosine triphosphatase (Na+, K+-ATPase) units] was increased by 70% in pregnancy and returned slowly towards normal values post partum. 4. Na+,K+-ATPase activity as determined by ouabain-sensitive 86Rb influx in artificial media was also increased in pregnancy by 13%. It returned towards normal post partum. 5. The increases in Na+,K+-ATPase in pregnancy were not closely related to the concomitant increases in aldosterone or cholesterol nor to reticulocytosis and were not affected by 7 days of high (greater than 250 mmol/day) or low (less than 50 mmol/day) sodium intake.     

Effects of oral contraceptives containing oestrogen combined with norethisterone or levonorgestrel on erythrocyte cation transport in normal women.

1. Studies were undertaken in pre-menopausal women to examine the effects of treatment with standard oestrogen-progestogen and progestogen-ony oral contraceptives on erythrocyte Na+,K+ co-transport and Na(+)-Na+ countertransport over 3- and 6-month periods. Concurrent observations were made on other erythrocyte cation transport components, plasma lipid concentrations, plasma renin activity, plasma aldosterone concentration and blood pressure. 2. Na+,K+ co-transport, measured as the ouabain-resistant, frusemide-sensitive component of 86Rb+ influx, and Na(+)-Na+ countertransport, measured as the ouabain-resistant, phloretin-sensitive component of 22Na+ influx, were both increased in women taking, on days 1-21 of their cycle, ethinyloestradiol (30-50 micrograms) combined with norethisterone (1000 micrograms or 500-1000 micrograms) for 3 or 6 months. Neither of these fluxes was increased in a control group of women, or in women treated for the same time periods with ethinyloestradiol combined with levonorgestrel. 3. In a separate study of erythrocyte cation transport (excluding Na(+)-Na+ countertransport), in which women undertook treatment with norethisterone only (350 micrograms/day) for 6 months starting 6 weeks post partum, no changes in Na+,K+ co-transport were observed at 3 or 6 months; there were no changes in cation transport in a corresponding control group. 4. The results of these studies confirm that certain oral contraceptive compounds can alter erythrocyte cation transport, and indicate that norethisterone in higher dose preparations is the component predominantly responsible. The alterations observed could not be explained by a direct link with concurrent changes in plasma triacylglycerol concentrations or in the renin-aldosterone axis and were not closely associated with elevation of blood pressure.     

慢性阻塞性肺疾病急性加重期患者体液离子含量的变化

目的：了解慢性阻塞性肺疾病（COPD）患者体液离子含量的变化。方法：选择46例合并肺心病的COPD急性加重期患者，测定其血清、红细胞、白细胞及24h尿K、Na、Ca、Mg离子含量。结果：患者自细胞Ca增高，红细胞Ca、Mg、K及白细胞Mg、血清Mg、Na均显著降低。红细胞Mg与白细胞Mg显著正相关。该组患者尿Ca增多占54％，尿K、Na、Mg减低者分别占92％，65％及32％。结论：COPD患者存在K、Mg缺失，用红细胞Mg评价机体的Mg状态更具有实用性。     

Lack of effect of clinical doses of cyclosporin A on erythrocyte Na+/K+-ATPase activity.

Cyclosporin A (CsA) may exert its cytotoxic effects by altering the activity of different plasma membrane transport systems. Although CsA may act at the gene level, it has been also suggested that it can directly alter transport processes at the plasma membrane. To examine this possibility in a physiological context, we determined Na(+)/K(+)-ATPase activity in erythrocytes from two groups of subjects receiving CsA treatment: group I consisted of kidney transplant patients, and group II comprised patients with steroid-resistant idiopathic nephrotic syndrome. Group I patients showed a marked decrease (35%) in the activity of the Na(+)/K(+)-ATPase in erythrocytes immediately after surgery, before the initiation of CsA treatment. The activity remained low 2 days after the introduction of CsA, but had recovered to the original (pre-surgery) value 1 month later. Group II patients showed the same pattern of erythrocyte Na(+)/K(+)-ATPase activity as those in group I. When the blood CsA levels from all patients were plotted against the corresponding erythrocyte Na(+)/K(+)-ATPase transport activity, a significant linear correlation was found. Higher levels of CsA in the blood were correlated significantly with increased Na(+)/K(+)-ATPase activities. The blood sodium concentration was also correlated positively with both erythrocyte Na(+)/K(+)-ATPase activity and blood CsA concentration. Thus CsA treatment is not associated with inhibition of the Na(+)/K(+)-ATPase in erythrocytes.     

Red blood cell sodium and potassium fluxes in psoriatic patients

Psoriasis might be a widespread membrane disorder. Therefore, the red blood cell sodium, potassium and lithium outward fluxes (through Na-K-ATPase, Na-K-Cl co-transport, Li-Na countertransport and passive permeability), as well as the Na and K content, were studied in 31 psoriatic patients and 23 normal controls. A significant increase in intracellular potassium content, in the maximal velocity of the Na-K ATPase and of Na-K-Cl co-transport as well as in the outward passive permeability for Na were found in the psoriatic patients compared with controls. On the contrary, no differences were observed in sodium content, Li-Na countertransport and passive potassium permeability between the two groups. These results are compatible with a selective increase in inward, as well as outward, membrane permeability to sodium, which is compensated for by increased activity of the Na-K pump, and of the outward Na-K-Cl cotransport with a secondarily increased erythrocyte potassium content. They indicate that the red blood cell might be a useful model for the study of membrane transport in psoriatics.     

Role of cell membrane abnormalities in the etiology of arterial hypertension

AIM: To study the role of cell membrane disorders in the formation of arterial hypertension under conditions of Extreme North. MATERIALS AND METHODS: A total of 128 men aged 20-48 years with essential hypertension (EH) were examined. All of them worked in the duty regimen at the Extreme North. Control group consisted of EH patients living in the temperate climatic zone. Central and peripheral hemodynamic parameters and cell membrane characteristics were studied: activities of transmembrane ion transport enzymes, intracellular electrolytes sodium and calcium, lipid peroxides (LPO), antioxidant defense values in erythrocyte membranes, plasma and cell membrane cholesterol. RESULTS: Activation of LPO processes and decreased antioxidant defense in both groups modified the lipid spectrum of cell membranes. The levels of intracellular calcium and sodium were increased, activities of Na(+)-K(+)-ATPase and Ca(2+)-ATPase decreased; total peripheral vascular resistance and left ventricular myocardium were progressively increasing. CONCLUSION: Membrane-destabilizing processes and hemodynamic shifts were more expressed in subjects with arterial hypertension working in the duty regimen.     

Correction of hypokalemia corrects the abnormalities in erythrocyte sodium transport in Bartter''s syndrome

In Bartter's syndrome, the defective renal tubular transport has been postulated to be a manifestation of a more generalized membrane abnormality. To explore this possibility, sodium concentration, ouabain-sensitive (pump transport), ouabain-resistant but furosemide-sensitive (Na-K-Cl cotransport), and ouabain- and furosemide-resistant (passive transport) 22Na effluxes were measured in erythrocytes obtained from nine patients with Bartter's syndrome before and during correction of hypokalemia. Intracellular [Na+] in erythrocytes obtained from nine patients with Bartter's syndrome was significantly (P less than 0.001) higher than that in 30 normal controls (11.8 +/- 1.8 vs. 7.3 +/- 1.4 mmol/liter cells). Pump transport and Na-K-Cl cotransport 22Na effluxes were significantly (P less than 0.01) increased, whereas the rate constant for these effluxes as well as for passive 22Na efflux did not differ from normal. Correction of hypokalemia and maintenance of a normal serum potassium decreased intracellular [Na+] to 8.2 +/- 1.8 mmol/liter cells, a normal value, and corrected the ouabain-sensitive and furosemide-sensitive 22Na effluxes. The results indicate that exposure of erythrocytes to a low potassium environment is responsible for the high intracellular [Na+] and, in turn, the high sodium efflux in Bartter's syndrome. The normal sodium efflux observed during correction of hypokalemia and the consistently normal rate constants for all three efflux parameters measured suggest that intrinsic sodium transport processes in erythrocytes are normal in Bartter's syndrome.     

Transmembrane cation fluxes and fatty acid composition of erythrocytes in psoriatic patients.

Cation transport systems and lipid composition of erythrocyte membrane were studied in 27 psoriatic patients and in 34 healthy individuals. Whereas intracellular Na and K content, Na- and K-passive permeability and Li-Na countertransport of psoriatics did not show any statistical difference from normals, the Na/K ATPase pump activity was significantly higher and Na-K cotransport was significantly lower. Membrane lipid composition of psoriatics was different from normals: an increase in arachidonic acid and in unsaturated (poly- and total unsaturated) fatty acid content was found. A positive correlation was demonstrated between unsaturated/saturated fatty acid ratio and Na/K ATPase pump activity. These results demonstrate an alteration of erythrocyte Na/K ATPase pump and Na-K cotransport in psoriasis. These alterations of cation transport are associated with a perturbation of membrane fatty acid composition which appears a widespread phenomenon in cells of psoriatic patients.     

Abnormal membrane sodium transport in Liddle''s syndrome

We have documented the presence of abnormal sodium transport in Liddle's syndrome by measuring sodium concentration, sodium influx, and fractional sodium outflux in vitro in erythrocytes from normal subjects, two patients with Liddle's syndrome, and one patient with primary hyperaldosteronism. Sodium influx and fractional sodium outflux, but not sodium concentration, were significantly increased in patients with Liddle's syndrome. Sodium outflux in a patient with primary hyperaldosteronism did not differ significantly from normal. These alterations of sodium transport in erythrocytes from patients with Liddle's syndrome were not attributable to circulating levels of aldosterone, renin, angiotensin, or serum potassium. Furthermore, changes in aldosterone secretory rate and levels of circulating renin produced by varying dietary sodium intake, did not alter sodium influx or fractional sodium outflux in either patients with Liddle's syndrome or normal subjects. The response of fractional sodium outflux and sodium influx to ouabain, ethacrynic acid, and to changes in the cation composition of the incubation medium suggests that the increased sodium fluxes in Liddle's syndrome do not result solely from a quantitative increase in those components of sodium transport which occur in normal human erythrocytes. Instead, at least a portion of the increased erythrocyte sodium transport in Liddle's syndrome represents a component of sodium transport which does not occur in normal human erythrocytes.     

Continent intestinal reservoir

In this series, 170 patients have received a continent intestinal reservoir, with follow-up of one to eight years. In 126 a conventional ileostomy was converted to a continent intestinal reservoir, 38 at the time of coloproctectomy. Six had an unsatisfactory ileoanal or ileorectal anastomosis initially, and 26 (15%) required revisional surgery for problems involving the reservoir or valve. The incidence of valve slippage was 3%. Eighty-five percent achieved a normally functioning small bowel reservoir with one operation, and 19 more patients were added with one additional operation, for an ultimate good result of 96% with two operations at most. The average reservoir capacity is 400 ml, and most patients empty the pouch two or three times per day. Under favorable circumstances, the continent intestinal reservoir is preferable for most patients after coloproctectomy.     

Cardiac Na+, K+-adenosine triphosphatase inhibition by ouabain and myocardial sodium: a computer simulation.

The major evidence against the hypothesis that Na+, K+-adenosine triphosphatase (Na+, K+-ATPase) inhibition is the mechanism of the positive inotropic action of digitalis is that the myocardial sodium content does not increase at the time of the inotropic response. In order to understand the relationship between sodium pump inhibition and myocardial sodium content, a computer simulation of the intracellular sodium concentration ([Na+]i) during a cycle of myocardial function was performed. The model for the computer simulation is a small compartment adjacent to the inner surface of the sarcolemma. The change in [Na+]i in this compartment is determined by the rate of sodium influx (published data utilized) and the rate of active sodium transport was estimated from the activities of partially purified dog heart Na+, K+-ATPase preparations assayed with various concentrations of sodium and ouabain. The initial rapid sodium influx results in maximal sodium pump activation, but the pump activity decreases with time as the [Na+]i decreases. Thus, the sodium pump functions at a rate close to its maximal velocity during the initial phase of each cycle but at reduced rates during the later phase. Inhibition of Na+, K+-ATPase by ouabain decreases the maximal velocity during the intiial phase of each cycle but at reduced rates during the later phase. Inhibition of Na+, K+-ATPase by ouabain decreases the maximal velocity of the sodium pump but increases the time in each cycle at which the sodium pump operates at its highest possible rate under these conditions, i.e., a rate close to the inhibited maximal velocity. A 40% inhibition of Na+, K+-ATPase activity, caused by inotropic concentrations of ouabain, increases the peak [Na+]i but fails to cause intracellular sodium accumulation since [Na+]i approaches control levels before the beginning of the next cardiac cycle. With greater enzyme inhibition, caused by arrhythmic concentrations of ouabain, [Na+]i fails to return to the precycle level and thus each subsequent cycle causes a progressive accumulation of myocardial sodium. Computer simulation predicts that a positive inotropic concentration of ouabain causes a myocardial sodium accumulation at a high heart rate but not at a lower heart rate. This was confirmed by experiments with Langendorff preparations of guinea-pig hearts. It is concluded that a moderate sodium pump inhibition by inotropic concentrations of ouabain enhances the intracellular sodium transient (a transient increase in intracellular sodium concentration associated with each membrane excitation) but does not cause a significant myocardial sodium accumulation at normal heart rates. A progressive myocardial sodium accumulation occurs only when the degree of Na+, K+-ATPase inhibition exceeds a critical magnitude.     

Ileoanal reservoir: functional results and management

Restorative proctocolectomy with ileoanal reservoir is an alternative to Brooke ileostomy. This study of 56 patients emphasizes functional results and management of the loop ileostomy, transient incontinence, frequency of bowel function, constipation, perianal skin, and psychosocial issues.     

Endogenous digoxin-like immunoreactivity and erythrocyte sodium transport in uraemic patients undergoing dialysis

1. Erythrocyte Na+ transport (Na+ pump activity, co-transport, countertransport and passive Na+ efflux) and intracellular Na+ concentration were studied in 10 normal individuals and in 29 uraemic patients on chronic haemodialysis, before and after a haemodialysis session. Eight of them fulfilled the criteria of hypertension. 2. Normotensive patients before haemodialysis were classified in two groups: group 1 (pump-) with decreased erythrocyte Na+ pump activity, and group 2 (normal pump) with normal erythrocyte Na+ pump activity. Group 1 showed, compared with controls, a normal intracellular Na+ concentration and a decreased co-transport, but no difference in either countertransport or passive Na+ efflux. After haemodialysis this difference disappeared. Before haemodialysis, group 2 showed a high intracellular Na+ concentration, but activities of the Na+ transport systems studied were similar to those of controls. After haemodialysis, cell Na+ concentration decreased to a level not significantly different from that of controls. 3. Both before and after haemodialysis, hypertensive patients showed Na+ transport system activities and an intracellular Na+ concentration similar to those of controls. 4. Endogenous digoxin-like immunoreactivity (EDLI) and erythrocyte Na+ transport were studied in five normotensive and five hypertensive patients, before and after haemodialysis. EDLI in plasma was similar in both groups before and after haemodialysis. No correlation was found between EDLI and erythrocyte Na+ pump activity. 5. These results suggest the existence in some dialysed uraemic patients of alterations in erythrocyte Na+ fluxes, which may be corrected by haemodialysis. EDLI and erythrocyte Na+ fluxes do not seem to be markers of secondary hypertension in these patients.     

Oral magnesium supplements reduce erythrocyte dehydration in patients with sickle cell disease.

Intracellular polymerization and sickling depend markedly on the cellular concentration of sickle hemoglobin (Hb S). A possible therapeutic strategy for sickle cell disease is based on reducing the cellular concentration of Hb S through prevention of erythrocyte dehydration. The K-Cl cotransporter is a major determinant of sickle cell dehydration and is inhibited by increasing erythrocyte Mg content. We studied 10 patients with sickle cell disease before treatment and after 2 and 4 wk of treatment with oral Mg supplements (0.6 meq/kg/d Mg pidolate). Hematological parameters, erythrocyte Na, K, and Mg content, erythrocyte density, membrane transport of Na and K, and osmotic gradient ektacytometry were measured. We found significant increases in sickle erythrocyte Mg and K content and reduction in the number of dense sickle erythrocytes. Erythrocyte K-Cl cotransport was reduced significantly. We also observed a significant reduction in the absolute reticulocyte count and in the number of immature reticulocytes. Ektacytometric analysis showed changes indicative of improved hydration of the erythrocytes. There were no laboratory or clinical signs of hypermagnesemia. Mild, transient diarrhea was the only reported side effect. We conclude that oral Mg supplementation reduces the number of dense erythrocytes and improves the erythrocyte membrane transport abnormalities of patients with sickle cell disease.