Hypochlorhydria and hypergastrinemia and their association with gastrointestinal bleeding in young patients with chronic renal failure

In 40 young patients with chronic renal failure (CRF) on maintenance hemodialysis and 22 control subjects, (1) basal and test meal-stimulated gastrin concentrations, (2) basal and pentagastrin-stimulated gastric acid outputs, and (3) endoscopic examinations were studied. Age-matched CRF patients with control subjects had higher circulating gastrin levels both in the fasting and the test meal-stimulated state and they also had hypochlorhydria. After a test meal, the peak increment of serum gastrin in the CRF patients was more prolonged and greater than in controls. Endoscopic findings showed that the most predominant lesion in the CRF patients was hemorrhagic gastritis. Nine (64.2%) out of 14 patients were hyposecretors and none were hypersecretors. Patients with hyposecretion had higher gastrin levels as well as the same incidence of abnormal endoscopic findings as patients with normosecretion. It is concluded that hypergastrinemia in young CRF patients might be due to a combined effect of impaired renal clearance capacity and overproduction of gastrin associated with hypochlorhydria and also that the cause of gastritis in the young CRF patients might partly be due to a relative impairment of the mucosal defensive mechanism to acid. Our data suggest that the parietal cell response to gastrin in CRF patient may be impaired.

Effect of PSK, a protein-bound polysaccharide from Coriolus versicolor, on drug-metabolizing enzymes in sarcoma-180 bearing and normal mice

The effects of PSK and Propionibacterium acnes (anaerobic Corynebacterium) on hepatic drug-metabolizing enzymes were studied using sarcoma-180 bearing and non-tumor bearing mice. PSK had no influence on aminopyrine N-demethylase and aniline hydroxylase activities, cytochrome P-450 concentration in hepatic microsomes, and the reductase activity of cytochrome c in normal mice. The content of cytochrome P-450 was not significantly reduced in S-180 bearing mice. On the other hand, P. acnes administration significantly decreased the amount of cytochromes P-450 and b5 and aminopyrine N-demethylase activity. When FT-207 (Tegafur) was administered orally to S-180 bearing mice combined with the immunoadjuvants, only P. acnes significantly reduced the 5-FU levels in the serum and some organs.

Hypochlorhydria and hypergastrinemia and their association with gastrointestinal bleeding in undialyzed and hemodialyzed patients

In 15 undialyzed (UD) patients and 26 hemodialyzed (HD) patients, (1) basal and test meal-stimulated gastrin concentrations, (2) basal and pentagastrin-stimulated gastric acid outputs, and (3) endoscopic examinations were studied. Also studied were the morphological and functional differences of the gastrointestinal tract between UD and HD patients. HD patients had lower gastric acid outputs and higher circulating gastrin levels in the fasting state. After a test meal, the peak increment of serum gastrin in UD and HD patients occurred 30 and 60 min later, respectively, and the response was prolonged in each group. Endoscopic findings showed that the incidence of abnormalities in each group was very similar, that is, the most predominant lesions in each group were hemorrhagic and atrophic gastritis. The data suggested that the response to gastrin of parietal cell and the defensive mechanism of gastrointestinal mucosa in HD patients may be impaired.

Quantitative description of nuclear morphology in assessing resistance of sarcoma 180 to adriamycin

Resistance to adriamycin generally is explained through changes of cell/drug interactions that possibly reflect structural alterations of intracellular targets. One of the main targets of adriamycin is believed to be nuclear chromatin. In order to recognize chromatin alterations, we studied cell nuclei morphology and chromatin structure by means of digital image analysis. The studies were performed in both adriamycin-sensitive and -resistant Sarcoma 180 cell lines which were cultured under growth-stimulated and nonstimulated conditions. Using specially developed methods, we extracted parameters characterizing geometrical, optical, and structural properties of the cell nuclei from light microscopical images. The latter parameters concerned microscopical appearances of condensed chromatin and were described by features of high-optical-density regions. The results demonstrated that the quantitative criteria applied enabled the discrimination of sensitive and resistant cells. The most important parameters are the nuclear size, number, distribution, and optical density of condensed chromatin regions. In addition, the criteria permit recognition of changes related to differences in the growth conditions of the cells. The data of the image analysis suggest that adriamycin resistance in Sarcoma 180 cells is associated with characteristic patterns of cell nuclear morphology which can be described with a sufficient number of appropriate parameters. The advantages of image analysis are evident when these results are compared with the flow cytometric findings. The conclusion is that structural features of nuclear chromatin provide information essential for the assessment of drug resistance.

Na-dependent effects of DOCA on cellular transport properties of CCDs from ADX rabbits

Microelectrode methods were used to assess the Na-dependent effects of mineralocorticoids on the conductive transport properties of cortical collecting ducts (CCD) from adrenalectomized (ADX) rabbits. Rabbits were divided into four groups: control, 3 h treatment with deoxycorticosterone (DOCA), 18 h DOCA treatment, and 18 h DOCA plus amiloride treatment. After only 3 h of DOCA treatment the transepithelial potential (VT) increased significantly from -1.4 to -8.7 mV, and after 18 h VT increased further to -19.3 mV. The basolateral membrane potential (Vb) significantly increased after 18 h (from -61.6 to -87.6 mV). However, compared with treatment with DOCA alone for 18 h, both -VT and -Vb were significantly attenuated with DOCA plus amiloride treatment to -8.3 and -72.9 mV, respectively. The apical membrane Na and K currents (INaa and IKa) and conductances (GNaa and GKa) were all increased after 3 h DOCA treatment. After 18 h of DOCA treatment, IKa, INaa, and GKa increased further, but GNaa remained unchanged. On simultaneous treatment with DOCA and amiloride, the maximum pump current (Ipmax), IKa, INaa, and GKa but not GNaa were all reduced significantly. These results support a mechanism whereby mineralocorticoids first increase GNaa. A rise in cell Na results then in the simultaneous increase in GKa and sodium transport, probably by insertion of new Na pumps. An additional direct effect of DOCA on GKa and Ipmax is not excluded.

Effects of adrenalectomy on CCD: evidence for differential response of two cell types

Electrophysiological and chemical methods were used to determine the Na and K transport properties of the isolated cortical collecting duct (CCD) of control and adrenalectomized (ADX) rabbits. Net fluxes of Na (JNa) and K (-JK) in controls were 5.7 and 3.2 pmol . mm-1 . min-1 and in ADX were 1.0 and 0.7 pmol . mm-1 . min-1, respectively, similar to electrically determined rates. In separate experiments, blind impalement of cells from adrenal intact (group 1), ADX (group 2), and ADX rabbits treated with deoxycorticosterone (group 3) allowed identification of two distinct cell types, majority cells (MA) and minority cells (MI). In all groups, MA were distinguished from MI by a relatively high basolateral membrane potential (-Vb), low apical membrane fractional resistance (FRa), and presence of apical and basolateral membrane K conductances. Vb of MA (-82.4 mV) was significantly hyperpolarized in groups 1 and 3 combined, when compared with group 2 (-66.4 mV). However, there was no significant difference between Vb of MI in group 2 (-38.9 mV) and Vb of MI in groups 1 and 3 (-36.2 mV). In MA of group 1 equivalent circuit values of apical membrane Na and K conductances (GNaa, GKa) and maximum pump current (Ipmax) were 0.84 and 6.72 mS/cm2 and 46.7 microA/cm2, respectively. These values in group 2 were significantly lower (0.28 and 1.52 mS/cm2 and 8.7 microA/cm2, respectively). It is concluded that two cell types can be distinguished electrically in the CCD. MA have properties consistent with principal cells and MI have properties consistent with intercalated cells. ADX causes a decrease in GNaa, GKa, and Ipmax of PC that results in proportionate decreases in INaa and IKa.

A case of rhabdomyolysis in chronic renal failure

Rhabdomyolysis can be induced by a variety of physical and chemical insults to skeletal muscle. Though there are only a few reports of myositis associated with viral diseases, and no reported cases of virus-induced rhabdomyolysis in uremic patients. Chronic uremic states have been known to potentiate a variety of metabolic and immunological abnormalities. Present case had an acute, progressive and fatal rhabdomyolysis which was thought to be induced by virus infection. A 43-year-old man had received hemodialysis therapy for 8 years. He suffered from an upper respiratory tract infection 11 days before admission. On admission, he was diagnosed as rhabdomyolysis with severe lactic acidosis and marked hyperkalemia. Although intensive care had been performed, he died of uncontrollable hyperkalemia (10.0 mEq/L) 2 days after admission. Maximum CPK and GOT levels were 105,200 and 56,800 mU/ml, respectively. Most probable cause of rhabdomyolysis was thought to be Parainfluenza type-3 infection, though histological examination failed to prove virus infection.

Polycythemia of end-stage renal failure: no inhibition of erythropoiesis by uremic serum and markedly increased serum erythropoietin level

This report describes the case of a 50-year-old male with end-stage renal failure accompanied with congenital heart disease and polycythemia. After he had received continuous ambulatory peritoneal dialysis for 1 year, he still remained polycythemic and his serum erythropoietin titer, assayed using fetal mouse liver cells, was markedly increased. An inhibitory effect on erythropoiesis was not detected by this method. Bone marrow examination showed erythroid hyperplasia. These phenomena could be explained by an overproduction of erythropoietin by the remnant kidneys or extrarenal organs, such as the liver, in response to persisting hypoxia. The patient's bone marrow was still responsive to erythropoietin.

Image analysis of hepatocyte nuclei in assessing di(2-ethylhexyl)phthalate effects eluding detection by conventional microscopy

The effect of di(2-ethylhexyl)phthalate (DEHP) administered in single intraperitoneal doses of 30, 300 and 3000 mg/kg in Syrian golden hamsters was studied by means of routine pathologic investigations, electron microscopy and image analysis. The morphological evaluations did not show apparent differences between the control and treated animals. Such differences, however, were recognized by using image analysis. They concerned morphology of the hepatocyte nuclei and were defined by quantitative parameters reflecting geometrical, optical and structural properties. Of importance for differentiating dose/effect relationships were features of chromatin structure. In order to describe those features we developed special algorithms capable of identifying and characterizing regions of condensed chromatin as subimages. These were distinguished by their size, shape and optical density and showed typical distributions within the nucleus. As our results demonstrate, image analysis methods permit detection of DEHP related pathology in animals which, as far as is evident from routine morphologic evaluations, belong to the no-effect experimental group.

Biosynthesis and intracellular processing of carbonic anhydrase in Chlamydomonas reinhardtii

Carbonic anhydrase (CA) of Chlamydomonas reinhardtii is a glycoprotein of 35 kDa which is localized outside the plasma membrane. The activity of CA was increased when the CO2 concentration during photoautotrophic growth was decreased to air level. After decreasing the CO2 concentration from 4% to 0.04%, several polypeptides including CA were induced continuously or transiently. To investigate the biosynthesis and intracellular processing of CA, the cells of wall-less mutant CW-15, which secretes CA into the culture medium, were pulse-labeled with radioactive arginine, chased, and radioactive proteins were immunoprecipitated with anti-CA serum. A 42-kDa polypeptide with isoelectric point (pI) of 7.1-7.3 was first synthesized. Within 5 min the molecular mass of this polypeptide was decreased to 35 kDa and it was then secreted into the culture medium within 30 min. This indicates that the former is the precursor form and the latter the mature form of CA. The primary translation product from poly(A)-rich RNA in a cell-free reticulocyte lysate system from a rabbit was a 38-kDa polypeptide. This was cotranslationally converted into the 42-kDa precursor in vitro in the presence of dog pancreatic microsomal membranes. As the 42-kDa precursor had a high affinity to concanavalin A, it was assumed to have a high-mannose-type oligosaccharide. The mature enzyme had a pI of 6.1-6.2 and was composed of more than two isoforms, which had a complex-type oligosaccharide with low affinity to concanavalin A. Chemical deglycosylation of the mature enzyme by trifluoromethanesulfonic acid indicated that the molecular mass of the polypeptide moiety was 32 kDa and the difference between this and the primary translation product suggests that cleavage of the polypeptide occurs during its biosynthesis.

[Effects of krestin (PSK) on drug-metabolizing enzymes with special reference to the activation of FT-207]

The effects of PSK on hepatic drug-metabolizing enzymes were investigated using Sarcoma 180-bearing and non-tumor-bearing ICR mice. PSK, an immunomodulator, has been commonly used in combination with tegafur for post-operative adjuvant chemotherapy. Tegafur is a typical masked compound transformed into 5-FU by the hepatic drug-metabolizing enzyme P-450. It has been reported that immunostimulants such as BCG and anaerobic Corynebacterium suppress the drug metabolism. PSK and Propionibacterium acnes were administered to mice inoculated s.c. with Sarcoma 180. It was demonstrated that Propionibacterium acnes had an effect of inhibiting these enzymatic activities, especially the amount of P-450 and cytochrome b5 and aminopyrine demethylation. On the other hand, PSK had no influence on the drug-metabolizing enzymes. Propionibacterium acnes was shown to decrease the 5-FU level in organs and sera of mice given FT-207 orally. By contrast, PSK showed no difference in 5-FU level compared to controls, indicating that PSK had no inhibitory effect on the activation of FT-207 by hepatic drug-metabolizing enzymes.

A simple and rapid method for the determination of macrophage activating factor involving a new type of apparatus suitable for the measurement of macrophage chemiluminescence

A simple and rapid method for the determination of macrophage activating factor is described. A new type of apparatus suitable for the measurement of macrophage chemiluminescence was devised, and the effect of lymphokines on macrophage activities was studied by measuring phorbol myristate acetate-induced luminol-dependent chemiluminescence. An outstanding feature of the new apparatus is that the plastic dish used for the cell culture can be used as the vessel for the chemiluminescence reaction. When thioglycollate-elicited ICR mouse peritoneal macrophages were incubated with lymphokines, their ability to generate chemiluminescence increased rapidly, reaching a maximal level at about 4 h, and then it progressively decreased to the control level at 8 h. Although this increasing effect of lymphokines on macrophage chemiluminescence was short-lived, it could be seen at a relatively low concentration, at which lymphokine-mediated cytotoxic activity of macrophages was not observed.

Quantitative analysis of the early changes of hepatocyte nuclei after treating Syrian golden hamsters with di(2-ethylhexyl)phthalate

Although the biological action of phthalates has been widely discussed there is little information on early cellular changes indicative for toxic or carcinogenic effects. To study subtle alterations in the cell morphology, we have by means of image processing evaluated the nuclei of hamster hepatocytes after treatment with di(2-ethylhexyl)phthalate given in single i.p. doses of 30, 300, and 3000 mg/kg. The results indicate that by using specially developed methods for analysis of images of cell nuclei and chromatin structure, it is possible to recognize changes eluding detection with usual light microscopy.

Dopaminergic inhibition of the action of vasopressin on the cortical collecting tubule

The dopaminergic inhibition of the hydrosmotic effect of vasopressin was studied by in vitro perfusion of the cortical collecting tubule isolated from the rabbit kidney. Arginine vasopressin (AVP) 100 microU/ml increased hydrosmotic water permeability (Pf, 10(-3) cm/s) by 11.4 +/- 1.59. Although dopamine 10(-5) M added alone to the bath did not affect Pf, the combined administration of 10(-5) M dopamine and 100 microU/ml AVP reduced the hydrosmotic effect of AVP to to 2.37 +/- 0.34. This inhibitory effect of dopamine was reversed by the simultaneous addition of 10(-5) M metoclopramide, a D2-antagonist. These observations suggest that dopaminergic receptors also exist in the cortical collecting tubule. The dopaminergic inhibition of the hydrosmotic action of AVP may be at least in part responsible for the diuretic action of dopamine.

Hypergastrinemia and achlorhydria in chronic renal failure

In 68 patients with chronic renal failure (CRF), 15 patients with duodenal ulcer and 15 normal subjects, basal plasma gastrin levels and basal and stimulated gastric acid secretion were measured. Two antisera were used: antiserum R2702 with specificity for human G34 and its N-terminal fragments [G34] and antiserum 2604 with specificity for the four main components of gastrin (total gastrin). Basal gastrin concentrations of both total gastrin and G34-like immunoreactivity (G34LI) were significantly higher in the CRF patients than in the other two groups, irrespective of dialysis. Total gastrin levels were not correlated with serum creatinine levels. Total gastrin levels were significantly decreased during hemodialysis, but G34LI levels showed no significant change. A small amount of total gastrin was detected in the dialysate by antiserum 2604. As to the postprandial gastrin release, in the first 30 min, the pattern of response in the patients with CRF was similar to that of the normal subjects, but the peak value was attained later, and the response was more rather prolonged. Gastric analysis showed a low basal acid out put and impaired acid secretion in response to secretagogue. It is concluded that (1) one of the predominant circulating forms of gastrin in CRF is G34LI, and (2) the hypergastrinemia in the CRF patients is probably due to reduced removal of gastrin by kidneys, increased gastrin production by impairment of the negative acid feedback mechanism induced by parietal cell dysfunction or reduced parietal cell sensitivity to gastrin by atrophic gastritis.

Light-induced conversion of nicotinamide adenine dinucleotide to nicotinamide adenine dinucleotide phosphate in higher plant leaves

Light-induced conversion of NAD to NADP was investigated in higher plants. Upon illumination, conversion of NAD to NADP was observed in intact leaves of wheat and pea following incubation in the dark. This conversion was also observed in mesophyll protoplasts of wheat leaves when they were isolated in the dark or isolated in light and then preincubated in the dark. Chloroplasts isolated from wheat protoplasts prepared in the dark carried out the conversion. The conversion in the mechanically isolated spinach chloroplasts was observed only when they were isolated in the dark from leaves preincubated in darkness.Sucrose density gradient centrifugation of wheat protoplast extracts and differential centrifugation of protoplast extracts from various plants showed that most of the NAD kinase was localized in the chloroplasts. Therefore, the conversion of NAD to NADP is considered to occur in the chloroplasts. However, with extracts of maize mesophyll protoplasts, the enzyme was localized in the extrachloroplast fraction. The NAD kinase was activated some 30% by illumination of leaves or protoplasts of pea and wheat after preincubation in the dark.These results suggest that, in general, the light-induced conversion of NAD to NADP occurs in the chloroplast and is catalyzed by photoactivated NAD kinase using photochemically produced ATP.

Properties of a Protein Activator of NAD Kinase from Plants

Purification of pea (Pisum sativum) seedling NAD kinase by DEAE-cellulose column chromatography resulted in loss of activity, due to dissociation of an activator from the enzyme. The purified enzyme preparation, which was almost completely inactive, regained the activity when the activator was added back.The activator was purified 320-fold by ion exchange chromatographies. The activator was susceptible to proteolytic enzymes, but not to ribonuclease, glucoamylase or pectinase, indicating that it is of a protein nature. This protein was relatively stable in boiling water, but susceptible to acid or alkali, especially under high temperatures. Restoration of catalytic activity of inactive enzyme was proportional to amounts of the activator added. Gel filtration indicated that molecular weight of the activator was 28,000.The activator was found in extracts from various plants.

Lipase Activities in Castor Bean Endosperm during Germination

Two lipases were found in extracts from castor bean (Ricinus communis L.) endosperm. One, with optimal activity at pH 5.0 (acid lipase), was present in dry seeds and displayed high activity during the first 2 days of germination. The second, with an alkaline pH optimum (alkaline lipase), was particularly active during days 3 to 5. When total homogenates of endosperm were fractionated into fat layer, supernatant, and particulate fractions, the acid lipase was recovered in the fat layer, and the alkaline lipase was located primarily in the particulate fraction. Sucrose density gradient centrifugation showed that the alkaline lipase was located mainly in glyoxysomes, with some 30% of the activity in the endoplasmic reticulum. When glyoxysomes were broken by osmotic shock and exposed to KCl, which solubilizes most of the enzymes, the alkaline lipase remained particulate and was recovered with the glyoxysomal "ghosts" at equilibrium density 1.21 g/cm(3) on the sucrose gradient. Association of the lipase with the gly-oxysomal membrane was supported by the responses to detergents and to butanol. The alkaline lipase hydrolyzed only monosubstituted glycerols. The roles of the two lipases in lipid utilization during germination of castor bean are discussed.