Peritoneal dialysis as therapy for electrolyte and acid base disorders

Peritoneal dialysis (PD) does not demand special equipment and its fluid composition can be easily changed according to the individual condition. Nine patients with chronic or acute renal failure presented severe metabolic alkalosis (MA). Hemodialysis (HD) proved virtually ineffective and the MA persisted. Physiological saline solution was adopted as the main component of the PD fluid for the treament of MA. By this method, CI– can be shifted from PD fluid to extracellular fluid (ECF) and HCO3– from ECF to PD fluid by ionic gradient. Therefore, pH and base excess (BE) of these patients both improved to the normal range after several fluid exchanges. The lowering effect of BE (ΔBE/L) ranged from 0.99 to 2.6. Hyposaline and normo-osmol solution (Na+ 70 mEq/L) were used for one patient with hypernatremia and consciousness disturbance. Serum (S)-Na decreased from 170 to 138 mEq/L, and consciousness became almost clear with the use of 15 L of PD fluid. Hypersaline solution (Na+ 190 mEq/L) was used for two patients with hyponatremia (S-Na 113 and 121 mEq/L). S-Na rose to within the normal range after 16 and 9 L in the two cases. A fluid mixed with distilled water, 10% NaCl and 7% NaHCO3 (HCO3– 34 - 68 mEq/L) was used to treat lactic acidosis in two patients. By this method, HCO3– can be shifted from PD fluid to ECF and lactic acid from ECF to PD fluid. Two patients recovered from prolonged shock, and pH was corrected by 10 L and 4 L, respectively. PD should be considered for application in other diseases besides renal failure.

Effect of different dialyzer membranes on cutaneous microcirculation during hemodialysis

AIM

Biocompatibility profiles of synthetic membranes may vary. In this prospective crossover study, we examined the effect of various membranes on cutaneous microcirculation during HD.

SUBJECTS AND METHODS

11 HD patients without cardiovascular complications were enrolled in this study. They were dialyzed using three types of membrane in a randomized order: ethylene-vinyl alcohol copolymer (EVAL), vitamin E-bonded cellulose (VE-C) and polysulfone (PS). The transcutaneous oxygen tension (TcPO2) was examined on the dorsum of foot to assess the cutaneous microcirculation. Serum biochemical parameters were also measured.

RESULTS

The TcPO2 as a percentage of the predialysis level decreased from the beginning of HD, and significant differences were observed after 15 min of HD between EVAL and the other 2 membranes (98 +/- 6% (mean +/- SD) for EVAL versus 89 +/- 7% for VE-C (p < 0.01) and 88 +/- 10% for PS (p < 0.01)). Furthermore, there were significant differences at 30 and 60 min between EVAL and PS (30 min: 93 +/- 9% for EVAL versus 85 +/- 7% for PS (p < 0.05); 60 min: 92 +/- 10% for EVAL versus 79 +/- 10% for PS (p < 0.01)). The serum level of thiobarbituric acid reactants (TBARs), a marker of lipid peroxidation, increased significantly at the end of HD relative to that at the beginning of HD when using a PS membrane (from 1.9 +/- 0.5 to 2.1 +/- 0.5 nmol/ml, p < 0.05).

CONCLUSION

Our results indicate that an EVAL membrane is superior to PS and VE-C membranes in terms of its smaller influence on cutaneous microcirculation. The repeated occurrence of microcirculatory disturbance during HD sessions may cause chronic endothelial dysfunction and even cardiovascular complications in HD patients.

Remarkable response of adult-onset ganglioneuroblastoma in the advanced stage to unrelated cord blood transplantation: Case report

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Background: Adult-onset ganglioneuroblastoma (GNB) is a rare disease that carries the gravest prognosis. In this case report, we discuss a case of adult-onset GNB in the advanced stage which has responded favorably to unrelated cord blood transplantation (UCBT). Methods: The patient was a 22-year-old male. Posterior mediastinal tumor was excised and a diagnosis of GNB was made. The severity of GNB was classified as stage IV because bone metastasis affected the entire body. Three courses of combination chemotherapy using cisplatin (CDDP), cyclophosphamide (CY), vincristine sulfate (VCR) and pirarubicin hydrochloride-adriamycin (THP-ADR) turned out to be ineffective. Local radiation therapy to control the tumor metastasis to the right great wing of the sphenoid bone resulted in augmentation of the tumorous lesion. Then, bone marrow destructive pretreatment consisting of anticancer therapy [etoposide (VP-16) and thiotepa] and total body irradiation (TBI, 12Gy) was followed by UCBT. Cyclosporin and mycophenolate mofetil were administered to prevent graft versus host disease (GVHD). Results: The blood type compatible two-loci HLA mismatch transplant had 3.2x107 nucleated cells/kg. After the cord blood transplantation, the patient suffered complications such as acute GVHD (grade III), veno-occlusive disease (VOD) and viral hemorrhagic cystitis. Neuron-specific enolase (NSE), a GNB tumor marker, gradually decreased from 220 ng/ml to the normal level. The bone metastatic tumors were reduced in a stepwise manner. Fluorodeoxyglucose-positron-emission tomography (FDG-PET) scan demonstrated complete disappearance of abnormal accumulation. Three hundred days have passed since the unrelated cord blood transplantation. The patient is surviving and in the disease-free state. Conclusion: The remarkable response of adult-onset GNB in the advanced stage to UCBT has demonstrated the definite graft versus tumor (GVT) effect of UCBT on GNB. UCBT is regarded as a promising therapeutic intervention in solid tumors that are not associated with blood disorder.

No significant financial relationships to disclose.

Effects of vitamin supplementation on microcirculatory disturbance in hemodialysis patients without peripheral arterial disease

AIMS

Dysfunctional endothelium caused by oxidative stress is thought to play a role in pathogenesis of a variety of conditions including atherosclerosis. We investigated whether a microcirculatory disturbance in hemodialysis (HD) patients was associated with increased oxidative stress and endothelial injury.

PATIENTS AND METHODS

Transcutaneous oxygen tension (TcPO2) on the dorsum of the foot at rest was measured as a marker of microcirculation in 33 patients undergoing HD without clinical manifestations of peripheral arterial disease and 20 healthy controls. Furthermore, in order to examine whether TcPO2 was affected by antioxidants, oral supplementation with a combination of vitamin C (200 mg daily) and vitamin E (600 mg daily) was administered for 6 months to 8 patients with microcirculatory disturbance (TcPO2 values of 50 mmHg or less). Serum biochemical parameters including vitamins were also measured.

RESULTS

Mean TcPO2 value was significantly lower in HD patients than in control subjects (47.9 +/- 13.5 mmHg versus 62.4 +/- 11.9 mmHg, p < 0.001). After vitamin supplementation, TcPO2 values remarkably increased (40.6 +/- 10.0 mmHg versus 57.4 +/- 6.5 mmHg, p < 0.005). Serum vitamin C and vitamin E levels increased significantly as well, while serum levels of thrombomodulin, a marker of endothelial injury, and thiobarbituric acid reactants, a marker of lipid peroxidation, were significantly decreased in comparison with those before supplementation.

CONCLUSIONS

Our results suggest that the microcirculatory disturbance in HD patients seems to be associated with endothelial damage caused by oxidative stress. Combined supplementation with vitamin C and vitamin E may be of clinical benefit in improving the cutaneous microcirculation by reducing oxidative stress.

Deglucuronidation of a flavonoid, luteolin monoglucuronide, during inflammation

In this study, we investigated whether luteolin monoglucuronide was converted to free aglycone during inflammation using human neutrophils stimulated with ionomycin/cytochalasin B and rats treated with lipopolysaccharide (LPS). beta-Glucuronidase activity was assayed using 4-methylumbelliferyl-glucuronide and methanol extracts of rat plasma containing luteolin monoglucuronide. The released 4-methylumbelliferone, a fluorescent molecule, was quantified by fluorometry. Deglucuronidation of luteolin monoglucuronide was examined by high-performance liquid chromatography (HPLC) analysis. HPLC analyses showed that the supernatants obtained from neutrophils stimulated with ionomycin/cytochalasin B hydrolyzed luteolin monoglucuronide to free luteolin. beta-Glucuronidase activity in human serum from patients on hemodialysis increased significantly compared with that from healthy volunteers. The beta-glucuronidase activity in rat plasma increased after i.v. injection of LPS. The ratio of luteolin to luteolin monoglucuronide in plasma of LPS-treated rats also increased. These results suggest that during inflammation beta-glucuronidase is released from stimulated neutrophils or certain injured cells and then deglucuronidation of flavonoids occurs.

Correlation between plasma endotoxin, plasma cytokines, and plasminogen activator inhibitor-1 activities in septic patients

The objective of this study was to evaluate the relation between the clinical and plasma parameters and the changes in plasma endotoxin activity with 2 hours of endotoxin-adsorbing therapy using polymyxin B (PMX). A total of 88 consecutive patients were admitted for PMX treatment of severe sepsis or septic organ failure. Standard supportive care was continued without alteration during PMX treatment. Endotoxin, tumor necrosis factor-alpha (TNFalpha), interleukin-6 (IL-6), IL-10, and plasminogen activator inhibitor-1 (PAI-1) activities and clinical parameters were measured before, immediately after, and the day after PMX treatment. The mean APACHE II and III scores were 24.2 +/- 1.0 and 85.8 +/- 3.0, respectively. The 2-week survival rate was 51.1%. In survivors, TNFalpha, IL-6, IL-10, and PAI-1 activities were significantly decreased during the 2-hour PMX treatment, the following day, or both times. There was no significant change in the parameters, except for TNFalpha, after PMX in nonsurvivors. In the subgroup whose plasma endotoxin decreased more than 30%, IL-6, TNFalpha, and PAI-1 significantly decreased after 2 hours of PMX or the following day (or both), but all four parameters in nonsurvivors showed no significant change. Hence PMX adsorbed plasma endotoxins and contributed to reductions in plasma proinflammatory cytokine levels and to improved clinical parameters during the 2-hour treatment. Changes in these parameters correlated with changes in plasma endotoxin activity in survivors whose plasma endotoxin levels were adequately reduced.

Effects of L-carnitine supplementation on renal anemia in poor responders to erythropoietin

While renal anemia can be successfully treated by use of erythropoietin (EPO) in most hemodialysis (HD) patients, some patients have anemia that is refractory to treatment with a high dose of EPO. We examined whether L-carnitine treatment could raise hematocrit (Hct) levels in such patients. Fourteen HD patients who showed a poor response to EPO and no evident factors which inhibit a response to EPO were selected to receive oral L-carnitine (500 mg/day) in a 3-month trial. During the study, 36% of the patients showed Hct increases of more than 2%. Statistical analysis revealed significant increases of Hct (p = 0.003) and total iron-binding capacity (TIBC) (p = 0.050) and a significant decrease of ferritin (p = 0.005). In addition, we found that red blood cells (RBCs) in HD patients contained a comparable level of carnitine to normal controls, despite the presence of serum carnitine deficiency, and that RBC carnitine was not removed through HD, in contrast to serum carnitine. These results suggest that RBC carnitine may be essential for RBCs to perform their metabolic function in renal anemia and that oral L-carnitine treatment could improve anemia in poor responders to EPO.

[Effective use of camostat mesilate for chronic disseminated intravascular coagulation complicated by thoracoabdominal aortic aneurysm]

A 73-year-old man who had been receiving treatment for hypertension and angina pectoris was admitted to hospital following a transient ischemic attack. He was diagnosed as having chronic disseminated intravascular coagulation (DIC) complicated by a thoracoabdominal aortic aneurysm, and was treated with heparin sodium and a protease inhibitor. Although the DIC was controlled, the patient had to remain hospitalized in order to receive the medication by continuous infusion. Therefore, the heparin sodium and protease inhibitor were replaced by camostat mesilate, a drug suitable for oral administration and widely used for treatment of chronic pancreatitis. The drug proved effective for the chronic DIC, thus allowing the patient to receive regular treatment on an outpatient basis, and improving his quality of life.

Effects of L-carnitine supplementation on cardiac morbidity in hemodialyzed patients

Cardiac diseases are well known among patients on maintenance hemodialysis (HD), and carnitine deficiency may be an important factor in cardiac morbidity. We studied the effects of low-dose L-carnitine treatment (500 mg/day) on chest symptoms (dyspnea on exertion, chest pain, palpitation), cardiac function, and left ventricular (LV) mass in 9 HD patients with reduced ejection fraction (EF). After 6 months of L-carnitine treatment, most patients had at least some improvement in chest symptoms, while LVEF was increased and LV mass was decreased. Carnitine fractions increased and reached plateaus at 2-3 times the baseline levels. These results suggest that prolonged low-dose L-carnitine treatment can improve the cardiac morbidity by restoring decreased carnitine tissue levels and impaired oxidation of FFA.

[A case of leukemic lymphoma complicated by M-proteinemia: effectiveness of long-term daily administration of oral low-dose etoposide in continuing remission]

A 51-year-old man was admitted with systemic lymph node adenopathy. Hematological examination on admission revealed leukocytosis, and 35% of leukocytes were classified as pathologically abnormal. Moreover, increases in serum IgM (kappa type) and plasma viscosity were recognized. Following biopsy of the lymph node, a diagnosis of non-Hodgkin's lymphoma (diffuse, mixed type) was made. After the implementation of combination chemotherapy, the results of hematological and physical examinations improved. As the nadir receded, serum IgM increased once more, and nine courses of chemotherapy were necessary. In order to promote steady progress toward discharge, etoposide therapy was instituted. Subsequent low-dose etoposide therapy at 50 mg/day rarely resulted in an increase in serum IgM, subjective or objective adverse effects, except for mild lekopenia. After discharge the patient was placed on intermittent etoposide therapy and remained in a state of remission for approximately 11 months. Fortunately, his rehabilitation was successful, and he returned temporarily to his former position. The 2nd remission has continued for approximately seven months. Consequently, long-term low-dose etoposide therapy is speculated to be a significantly useful therapeutic technique for intractable malignant lymphoma.

[Successful lithium carbonate therapy for a patient with intractable and severe aplastic anemia]

A 16-year-old female patient who had been given a diagnosis of severe aplastic anemia underwent 2 courses of a combined regimen of corticosteroid pulse therapy and androgen therapy. This proved ineffective. Antilymphocyte globulin therapy was also ineffective. The patient was then given lithium carbonate at a dose of 600 mg/day in combination with an androgen derivative. This had a dramatic effect on her peripheral blood smear. Within 3 weeks after the first course of this treatment, she no longer required red blood cell transfusions. Also, once the lithium carbonate dose was increased to 1,200 mg/day, the patient no longer needed exogenous platelet transfusions. Approximately 6 months after the start of combination therapy, a peripheral blood smear showed entirely normal results. However, 2 months after lithium carbonate was discontinued probably as a result of drug-induced liver dysfunction, both leukocytopenia and thrombocytopenia reappeared. Therefore, lithium carbonate was readministered at a dose of 400 mg/day, and later at a dose of 800 mg/day. Again, the patient showed improvements in 3 blood components without any adverse effects. We concluded that lithium therapy was remarkably useful for this patient with intractable and severe aplastic anemia.

Peripheral deletion of gammadelta T cells in haemodialysis patients

Many patients with end-stage renal disease have altered host defenses against infectious agents. We have demonstrated that T cells, which play an important role in the immunological response, may undergo apoptosis by the Fas system in uraemia. To elucidate whether gammadelta T cells, which function as a first defense against intracellular pathogens, are altered in number or characteristics in dialysis patients, surface expressions of TCR, LFA-1 and Fas antigen on peripheral T cells were examined by immunofluorescence analysis. We demonstrated that the proportions of peripheral gammadelta T cells are altered significantly in haemodialysis (HD) patients. Interestingly, there were marked differences in the levels of expression of LFA-1 and Fas antigen between the two types of T cells. Moreover, both the expression of LFA-1 and that of Fas antigen were enhanced significantly in HD patients compared with normal controls. These results suggest that circulating gammadelta T cells may be susceptible to activation-induced cell death in comparison with alphabeta T cells in uraemic environments.

Effects of L-carnitine supplementation on muscular symptoms in hemodialyzed patients

Various muscle symptoms are well recognized among patients on maintenance hemodialysis. Carnitine deficiency may be an important factor of dialysis-associated muscle symptoms, whereas high-dose L-carnitine supplementation may result in unphysiologically high plasma levels of carnitine and carnitine esters. We studied the effect of low-dose L-carnitine treatment (500 mg/d) on muscle symptoms, plasma carnitine fractions, and lipid profiles in 30 periodically dialyzed patients with muscular weakness, fatigue, or cramps/aches. After 12 weeks of L-carnitine treatment, about two-thirds of patients had at least some improvement in muscular symptoms, whereas carnitine fractions were normal or slightly above normal ranges, but lipid profiles showed no demonstrable changes. This study also showed the correlation between plasma-free carnitine deficiency and months on dialysis. These results suggest that prolonged low-dose L-carnitine treatment can improve dialysis-associated muscle symptoms by restoring carnitine tissue levels and washing out acyl moieties.

Increased serum midkine levels during hemodialysis using heparin in chronic renal failure

The heparin-binding growth factor midkine (MK) has been implicated in neuron growth, angiogenesis, and inflammation. In this study, to elucidate the involvement of MK in the development of pathologies associated with uremia, we examined the serum MK levels in patients receiving hemodialysis (HD) by a highly sensitive enzyme-linked immunoassay. Although no significant difference was found between control serum and serum before dialysis in HD patients, serum MK levels increased significantly at the early stage of HD sessions using heparin and gradually decreased after dialysis. In normal controls, intravenous administration of heparin induced a similar sudden increase of MK, but the subsequent decrease was also rapid. In an in vitro study, MK was released in time- and heparin-dose dependent manner from cultured vessels, but not from peripheral leukocytes. These results indicate that, in HD patients, MK is released mainly from endothelial cells immediately after administration of heparin during HD and disappears gradually from blood due to renal impairment. This phenomenon might affect some complications associated with HD.

[Apoptosis in uremic complication]

Chronic renal failure (CRF) is often complicated by lymphopenia and sometimes by hepatic dysfunction. To elucidate the involvement of apoptosis in these complications, we analyzed Fas antigen which mediates apoptosis on peripheral blood T cells and hepatic cells. T cells from uremic patients expressed Fas with higher intensity than control T cells. When cultured in vitro, uremic T cells were shown to undergo acceleratd apoptosis in correlation with Fas expression. Immunohistological analysis of liver tissues revealed that hepatocytes in patients both with chronic hepatitis and with CRF expressed higher levels of Fas than those in patients alone with chronic hepatitis. These results suggest that T cells and hepatocytes in CRF may undergo apoptosis by the Fas system.

Regulation of phosphorylation of Gi2 alpha protein controls the secretory response to isoproterenol in rat parotid tissues

Treatment of rat parotid tissues with 1 microM isoproterenol (IPR) for 10 min caused a 60% decrease in pertussis toxin (IAP)-catalyzed ADP-ribosylation of Gi alpha and resulted in supersensitivity of amylase secretion from the tissues. However, conversely, IPR treatment for 30 min caused a 40% increase in IAP-catalyzed ADP-ribosylation of Gi alpha, coupled with desensitization of amylase secretion. No changes in Gs function were observed in IPR-induced phenomena. Pretreatment with okadaic acid induced enhancement of the supersensitivity of amylase secretion and disappearance of the desensitization. These phenomena were accompanied with decreases in IAP-catalyzed ADP-ribosylation of Gi alpha. IPR treatment for 30 min caused a 50% decrease in phosphorylation of Gi2 alpha immunoprecipitated with anti-G protein antiserum (AS/7) from [32P]Pi-labeled cells, but such treatment for 10 min caused a 40% increase in phosphorylation in the cells pretreated with okadaic acid. Phosphorylation and dephosphorylation of immunoprecipitates with AS/7 by protein kinase A (PKA) and alkaline phosphatase caused decreases and increases in IAP-catalyzed ADP-ribosylation, respectively, indicating the presence of PKA-mediated phosphorylation sites on Gi2 alpha. Thus, the control of the phosphorylation of Gi2 alpha is of importance and relevance in the regulation of biological processes and cellular responses.

First evidence for accumulation of protein-bound and protein-free pyrraline in human uremic plasma by mass spectrometry

Glucose-derived advanced glycation end products (AGEs) cross-link proteins and cause various biological tissue damage. One of them, pyrraline [epsilon-2-(formyl-5-hydroxymethyl-pyrrol-1-yl) -L-norleucine], has been demonstrated by utilizing antibody to accumulate in plasma and sclerosed matrix of diabetic individuals, suggesting responsibility for diabetic complications. To elucidate the involvement of pyrraline in uremia, we examined the pyrraline levels in patients with chronic renal failure by a mass spectrometric approach. Here we show that protein-free pyrraline as well as pyrraline with binding protein are significantly increased in non-diabetic uremic plasma compared to healthy subjects. Our results suggest that circulating pyrraline could be a substance contributing to complications in uremia.

Relationship between susceptibility to apoptosis and Fas expression in peripheral blood T cells from uremic patients: a possible mechanism for lymphopenia in chronic renal failure

Chronic renal failure (CRF) is often complicated by lymphopenia, which may be partly responsible for immune deficiency. We hypothesized that lymphopenia in CRF might result from apoptosis of T cells in vivo. To elucidate the involvement of Fas antigen which mediates apoptosis, we analyzed Fas expression on peripheral blood T cells in uremic non-dialyzed (non-HD) patients and hemodialysis (HD) patients. T cells from both uremic groups expressed Fas with higher intensity than control T cells. When two uremic groups were compared, Fas intensity on T cells was significantly higher in non-HD patients than in patients on HD. Moreover, uremic T cells were shown to undergo accelerated apoptosis when cultured in vitro, in correlation with Fas expression. Our results suggest that T cells in CRF may undergo apoptosis by the Fas system and that hemodialysis treatment has beneficial effects in the light of the inhibition of T cell apoptosis.

Age-dependent changes in response of rat prostatic tissues to isoproterenol and forskolin: changes with sexual maturation in function of G proteins

Developmental changes in the responses of rat ventral prostate to isoproterenol (IPR) and forskolin (F) were studied in relation to the function of beta-adrenoceptor-adenylate cyclase system. The response of adenylate cyclase in the tissues to IPR at 10(-7)M and above was steadily enhanced after birth and reached a maximum at 12 weeks, followed by a decrease with age. In contrast, the response of the enzyme to F at 10(-7)M and above was highest at 2 weeks, but thereafter decreased. The changes in the response of the enzyme to IPR coincided with changes in the beta-adrenoceptor density and the binding ability of GTP binding proteins (G proteins) to GTP. The ADP-ribosylation of inhibitory G proteins (Gi proteins) catalyzed by pertussis toxin (IAP) decreased 70% in the tissues from 4 to 8 weeks, and then maintained this level. On the other hand, the ADP-ribosylation of stimulatory G proteins (Gs proteins) catalyzed by cholera toxin (CT) increased only 20% in the tissues from 2 to 4 weeks. Thus, the ratio of ADP-ribosylation of Gs to that of Gi significantly increased from 4 weeks, reaching a maximum at 12 weeks, but thereafter decreased gradually with age. These changes paralleled those in the function of G proteins and the response of the enzyme to IPR. It is suggested that the rapid and marked decrease in apparent level of Gi proteins in the rat ventral prostate after 4 weeks may have a key role in controlling the function of the beta-adrenoceptor-adenylate cyclase system in the tissues.

Mechanism of isoproterenol-induced heterologous desensitization of mucin secretion from rat submandibular glands. Regulation of phosphorylation of Gi proteins controls the cell response to the subsequent stimulation

Short-term treatment of rat submandibular tissues with 10 microM isoproterenol (IPR) resulted in reduction of mucin secretion in response to the agonist during further incubation, and in increases in EC50 values. This IPR-induced reduction of secretion was coupled with selective decreases in the number of beta-adrenoceptors in the tissues and in their affinity for agonists, as assessed by measurement of the specific binding of [3H]dihydroalprenolol. Treatment of the tissues with IPR caused a 30% decrease in IPR-stimulated adenylate cyclase activity and a 25% increase in the GTP binding capacity of inhibitory G proteins (Gi proteins). This IPR treatment triggered a 60% increase in the ability of pertussis toxin (IAP) to catalyze ADP-ribosylation of Gi proteins in the tissue membranes. Enhanced function of stimulatory G proteins (Gs proteins) was observed only during the first incubation of the tissues with IPR. The IAP-catalyzed ADP-ribosylation of Gi proteins in tissues treated with IPR was decreased by prior treatment with cyclic AMP dependent protein kinase, but was increased markedly by prior treatment with alkaline phosphatase. Neither IPR-induced desensitization of protein secretion nor increase in the IAP-catalyzed ADP-ribosylation of Gi proteins was observed in the tissues pretreated with 0.25 microM okadaic acid. These findings suggest that the regulation of Gi protein phosphorylation plays an important role in the IPR-induced heterologous desensitization of mucin secretion from rat submandibular glands.

Dephosphorylation of nuclear non-histone proteins in submandibular glands of rats treated with isoproterenol

Protein phosphatase that removed [32P]phosphate from non-histone proteins, i.e., phenol-soluble acidic proteins, more rapidly and strongly than from histone proteins was present in nuclei of rat submandibular glands, but was not associated with chromatin. Cyclic AMP (10(-4)-10(-2) mM) stimulated the dephosphorylation of non-histone proteins, but not that of histone proteins. After a single injection of isoproterenol (IPR), the dephosphorylation of non-histone proteins in rat submandibular gland nuclei increased within 15 min, reached a maximum in 30 min and returned to normal control levels within 4 h. The stimulation of dephosphorylation of non-histone proteins induced by IPR was not observed after prior treatment of the animals with dichloroisoproterenol. The dephosphorylation of histone proteins was not affected by the injection of IPR. Stimulation of beta-adrenoceptors with IPR in rat submandibular glands resulted in increase in cyclic AMP and decrease in RNA synthesis in the tissues in the first few hours after the injection. This decrease in RNA synthesis was temporary and was preceded by the increase in cyclic AMP level and in the dephosphorylation of non-histone acidic proteins in the tissues. These results suggest that protein phosphatase in nuclei plays an important part in the events controlling RNA synthesis by regulating the state of phosphorylation of non-histone acidic proteins. In addition, the phosphatase may be regulated by a function of the cytoplasmic membranes.

[Accumulation of a disopyramide metabolite in renal failure]

Twenty-nine cases of hypoglycemia induced by disopyramide (DP) have been reported in the literature to date. Twenty of the reported cases showed hypo-renal function and a high concentration was rare. DP is metabolized to mono-N-dealkyldisopyramide (MND) in the liver and accumulation of MND is to be expected in renal failure. Both DP and MND bind mainly to alpha-1-acid glycoprotein (AAG) in the plasma. In 10 hemodialysis (HD) patients with normal liver function receiving DP therapy in the steady state. DP, MND and AAG were measured pre- and post-HD. Ten patients with normal renal and liver function were selected as the controls. The DP concentration was 2.08 +/- 0.39 micrograms/ml (mean +/- SD) in the control group, and the pre- and post-HD levels were 2.40 +/- 1.08 micrograms/ml and 1.73 +/- 0.87 micrograms/ml, respectively, in the HD group. The MND concentration was 0.42 +/- 0.23 micrograms/ml in the controls, 1.53 +/- 0.52 micrograms/ml in pre-HD and 1.08 +/- 0.32 micrograms/ml in post-HD. Although DP and MND are both classified as substances of small molecular weight, the average decrease in plasma concentration from pre- to post-HD was under 30% with both agents. The MND/DP ratio in the HD group was higher than in the controls, but there was no significant difference between pre- and post-HD. The AAG level was 75 +/- 5mg/dl in the controls and 109 +/- 11mg/dl before HD in the HD group (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Age-dependent changes in the phosphorylation of nuclear proteins of submandibular glands in isoproterenol-treated rats

Age-dependent changes in the regulation of the phosphorylation of nuclear proteins were investigated in relation to DNA synthesis in rat submandibular glands after injection of isoproterenol (IPR). The level of phosphorylation of nuclear proteins in the tissue increased rapidly after birth, reaching a maximum at 4 weeks, and then decreased to the level of 52-week-old rats. The level of protein kinase activity in nuclei varied in parallel with that of phosphorylation of nuclear non-histone proteins after birth. The time after the injection of IPR required to initiate the phosphorylation of nuclear non-histone proteins of rat submandibular glands, which occurs prior to the onset of RNA synthesis that precedes the replication of DNA, increased with age. These results suggest that this delayed onset of phosphorylation plays a regulatory role in cell proliferation and cell function during aging.

Accumulation of a disopyramide metabolite in renal failure

Ten hemodialysis (HD) patients with normal liver function received disopyramide (DP) therapy in the steady state. DP, mono-N-dealkyldisopyramide (MND) and alpha-1-acid glycoprotein (AAG) were measured before and after HD. Ten patients with normal renal and liver function were selected as controls. The DP concentration was 2.08 +/- 0.39 micrograms/ml (mean +/- SD) in the control group, and the pre and post HD levels were 2.40 +/- 1.08 micrograms/ml and 1.73 +/- 0.87 micrograms/ml, respectively, in the HD group. The MND concentration was 0.42 +/- 0.23 microgram/ml in controls, 1.53 +/- 0.52 micrograms/ml in pre HD and 1.08 +/- 0.32 microgram/ml in post-HD. Although DP and MND are both classified as small molecular weight substances, the average decrease in plasma concentration from pre to post HD was under 30% with both agents. The MND/DP ratio in the HD group was higher than in controls, but there was no significant difference between pre and post HD. The AAG level was 75 +/- 5 mg/dl in controls and 109 +/- 11 mg/dL before HD in the HD group (p < 0.001). In conclusion, an MND accumulation was observed in HD patients receiving DP therapy. Because the anticholinergic effect of MND is 24 times that of DP, MND is thought to contribute in some way to the hypoglycemia induced by DP in renal failure.

Diurnal variation of amylase secretion is coupled with alterations of beta-adrenoceptors in the rat parotid gland

Diurnal changes in the neurotransmitter receptors are important for studying the receptor function in neurophysiology. The purpose of this study is to gain an insight into the regulatory mechanisms of the diurnal variation of amylase secretion. Rat salivary amylase levels showed a diurnal variation with two peaks, a marked peak at 13 h and a lesser peak at 21 h. This increase in salivary amylase levels was completely inhibited by pretreatment of rats with the beta-adrenergic antagonist propranolol, but not by the alpha-adrenergic antagonist phentolamine. Amylase level in parotid tissue homogenate also showed a diurnal change, but there was only one peak, at 13 h. The number of maximal binding sites (Bmax) for [3H]dihydroalprenolol (DHA) in parotid membranes showed a diurnal variation with two marked peaks at 13 and 21 h, but the affinity of parotid beta-adrenoceptors for agonists or antagonists did not show any diurnal changes. Phosphorylation of nuclear non-histone proteins in the rat parotid gland showed diurnal variation with two marked peaks at 13 and 21 h. These results indicate that a diurnal variation in the number of rat parotid beta-adrenoceptors, which is presumably regulated by gene expression, is coupled with a change in salivary amylase secretion.

Clinical Effect of Continuous Gastric Cooling for Massive Gl Bleeding in Uremia

Continuous gastric cooling (CGC) with dialysate was done in nine hemodiaysis patients with massive gastro-intestinal (GI) bleeding. Eight patients were treated by direct irrigation using a double-lumen naso-gastric (NG) tube without balloon. Four patients with bleeding from the duodenum (B-f-D) had complete hemostasis, and there was only one recurrence. However, two out of four patients with bleeding from the stomach (B-f-S) had complete hemostasis, but all four suffered recurrence. The NG tube had to be reinserted in three patients with B-f-S because of obstruction by clots. The direct irrigation method of CGC thus appears to be more effective for the treatment of B-f-D than B-f-S, so we investigated a three lumen, single-balloon catheter (3L-SBC) with which the bleeding site in the stomach can be cooled and pressed without removing coagula. CGC using the 3L-SBC was done in one patient with B-f-S, and complete hemostasis was obtained without recurrence.

Clinical effect of continuous gastric cooling for massive GI bleeding in uremia

Continuous gastric cooling (CGC) with dialysate was done in nine hemodiaysis patients with massive gastro-intestinal (GI) bleeding. Eight patients were treated by direct irrigation using a double-lumen naso-gastric (NG) tube without balloon. Four patients with bleeding from the duodenum (B-f-D) had complete hemostasis, and there was only one recurrence. However, two out of four patients with bleeding from the stomach (B-f-S) had complete hemostasis, but all four suffered recurrence. The NG tube had to be reinserted in three patients with B-f-S because of obstruction by clots. The direct irrigation method of CGC thus appears to be more effective for the treatment of B-f-D than B-f-S, so we investigated a three lumen, single-balloon catheter (3L-SBC) with which the bleeding site in the stomach can be cooled and pressed without removing coagula. CGC using the 3L-SBC was done in one patient with B-f-S, and complete hemostasis was obtained without recurrence.

Development of alumina ceramic transcutaneous connector to prevent skin exit site infections around CAPD catheters

It is very important to prevent skin exit site infections in order to continue continuous ambulatory peritoneal dialysis (CAPD) safely over the long-term. The silicon material conventionally used can result in sinus formation between the skin and the catheter, and may trigger exit site infections. To resolve this problem, we employed a bioinert, rigid, and nonporous transcutaneous connector made of alumina ceramic. Earlier long-term animal experiments with alumina ceramic placed in soft tissue demonstrated the outstanding biocompatibility of this material. The transcutaneous connector was designed with a simple cylindrical configuration; in order to make sufficient contact between this connector and the patient, a silicon tube was made into a swan neck catheter with a disk-shaped Dacron cuff at the upper position in order to reinforce adhesion to soft tissue. Ten CAPD patients (maximum time on dialysis of 14 months) have used the new CAPD catheter system with no exit site infections to date. Furthermore, there has been virtually no downgrowth of the skin around the connector, while the connector and tissue have remained in very close contact.

Peritoneal dialysis as therapy for electrolyte and acid base disorders

Peritoneal dialysis (PD) does not demand special equipment and its fluid composition can be easily changed according to the individual condition. Nine patients with chronic or acute renal failure presented severe metabolic alkalosis (MA). Hemodialysis (HD) proved virtually ineffective and the MA persisted. Physiological saline solution was adopted as the main component of the PD fluid for the treatment of MA. By this method, Cl- can be shifted from PD fluid to extracellular fluid (ECF) and HCO3- from ECF to PD fluid by ionic gradient. Therefore, pH and base excess (BE) of these patients both improved to the normal range after several fluid exchanges. The lowering effect of BE (delta BE/L) ranged from 0.99 to 2.6. Hyposaline and normo-osmol solution (Na+ 70 mEq/L) were used for one patient with hypernatremia and consciousness disturbance. Serum (S)-Na decreased from 170 to 138 mEq/L, and consciousness became almost clear with the use of 15 L of PD fluid. Hypersaline solution (Na+ 190 mEq/L) was used for two patients with hyponatremia (S-Na 113 and 121 mEq/L). S-Na rose to within the normal range after 16 and 9 L in the two cases. A fluid mixed with distilled water, 10% NaCl and 7% NaHCO3 (HCO3 34-68 mEq/L) was used to treat lactic acidosis in two patients. By this method, HCO3- can be shifted from PD fluid to ECF and lactic acid from ECF to PD fluid. Two patients recovered from prolonged shock, and pH was corrected by 10 L and 4 L, respectively. PD should be considered for application in other diseases besides renal failure.

An ovulation inducing agent containing clomiphene citrate causes DNA-strand breaks without SOS responses in Escherichia coli

Effects of Clomid, an ovulation-inducing drug containing clomiphene citrate, on Escherichia coli were investigated. Radiation-sensitive mutants, uvrA and recA, were more sensitive to Clomid than the parental wild-type strain. DNA synthesis in these two strains was more depressed by Clomid than that in the wild-type strain. Clomid caused DNA-strand breaks, but few SOS responses such as mutation, induction of prophage and expression of the umuC+ gene were induced.