[Diagnosis of paroxysmal nocturnal hemoglobinuria with cytofluorometric of molecules bound to the membrane by glycosylphosphatidylinositol groups]

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (NPH) is a clonal disease in which a deficit in the expression of molecules bound to the cell membrane by glycosyl-phosphatidylinositol (MUGFI) groups has been demonstrated. The MUGFI are widely distributed and among them proteins regulating the action of complement may be found. The development of monoclonal antibodies (MoAb) against MUGFI may allow the introduction of a new diagnostic method in this disease and increase the sensitivity, particularly in transfused individuals.

METHODS

The erythrocytic and leukocytic phenotype of 14 patients with NPH clonality demonstrated by the classic tests of sensitivity to the complement was analyzed by immunofluorescence techniques and flow cytometry with the use of MoAb which recognize MUGFI (CD55, CD59, CD14, CD16 and CD24).

RESULTS

Cells with a decrease or absence of MUGFI were observed in all the patients. The defect was demonstrated in the red cells, monocytes and neutrophils of all the patients, while it was only observed in the lymphocytes of three patients. The percentage of cells with a decrease in MUGFI was variable (2-100%) as well the pattern of deficiency against the different MoAb used. The MoAb with greatest sensitivity for the detection of clonal population were the CD59 in erythrocytes, the CD14 in monocytes and the CD24 in neutrophils. The CD16 was normal in one patient and the CD55 in two. The transfusion of packed red cells did not influence the abnormal leukocyte pattern, with abnormalities even being observed in the erythrocytary CD59. The Ham test was negative in those cases in which the percentage of negative CD59 erythrocytes was lower than 5% of the total erythrocytic population.

CONCLUSIONS

The study of glucosylphosphatidylinositol by flow cytometry and monoclonal antibodies is a useful technique for the detection and quantification of the nocturnal paroxistic hemoglobinuria clone even in transfused patients.

[International diffusion of clinical trials carried out in Spain. An analysis based on their publication in scientific journals]

BACKGROUND

Few studies have evaluated the clinical trials carried out in Spain and published in international journals. The present study has analyzed this situation over the period from 1981 to 1990.

METHODS

Spanish studies including "clinical trial" as a key word present in Excerpta Medica CD (Drugs and Pharmacology) or MEDLINE in the CD-ROM version were evaluated.

RESULTS

Two hundred forty-one original articles were obtained. The number of clinical trials was relatively stable from 1981 to 1986 (n = 8.15) increasing to a maximum from 1986 to 1988 (n = 64) with a posterior decrease. The languages of publication were English (51%) and Spanish (49%). A significant increase was observed in the number of articles published in English (p < 0.01) in the last five years. Phase III and IV clinical trials were the most frequent (89%) followed by those of phase II (9%) and phase I (2%). The open design predominated in the phase III-IV trials (58%) over the double blind trials (37%) and the single blind trials (5%). Among the former 70% were comparative and 57% followed randomized treatments. The clinical trials were published in 112 journals, Medicina Clínica (n = 32) and Current Therapeutic Research Clinical and Experimental (n = 6) were the most frequently used in Spanish and English, respectively. Two hundred sixty-three drugs were studied in the clinical trials, cisplatin was the most frequently studied (n = 10). The most commonly studied pharmacologic groups were antiinfectious (n = 40) and cytostatic (n = 35). The number of randomized clinical trials increased significantly after 1986 (p < 0.01).

CONCLUSIONS

An increase in the number of clinical trials published in international journals was observed with preference for publication in English. The growing presence of randomized double blind clinical trials suggests an improvement in the quality of the clinical trials performed in Spain, particularly after 1986.

Regulated expression of human insulin in the liver of transgenic mice corrects diabetic alterations

Transgenic mice expressing the P-enolpyruvate carboxykinase (PEPCK)/human insulin chimeric gene have been obtained as a model to study the feasibility of gene therapy for diabetes. These transgenic animals were healthy and normoglycemic and expressed human insulin in a physiologically regulated manner, mainly in the liver. Streptozotocin-treated transgenic mice had high levels of human insulin immunoreactivity in serum and showed a significant decrease (up to 40%) in glycemia compared with streptozotocin-treated control mice. The expression of genes involved in liver glucose metabolism, such as glucokinase, pyruvate kinase, and PEPCK, which is markedly altered by diabetes, was significantly recovered in transgenic mice treated with streptozotocin. In addition, the activity of both glucokinase and glycogen synthase, and the content of glucose 6-phosphate and glycogen, were normal in the liver, even when transgenic animals were treated with diabetogenic doses of streptozotocin. These results constitute an indication in vivo that diabetes gene therapy is possible, by means of the production of insulin in extrapancreatic tissues.

Expression of the neomycin-resistance (neo) gene induces alterations in gene expression and metabolism

The amino 3'-glycosyl phosphotransferase (neo) gene is the selectable marker most widely used in stable transfection or infection protocols. Because the neo gene product has phosphotransferase activity, it might modify the phosphorylation state when introduced in mammalian cells. NIH-3T3 fibroblast cells expressing the neo gene, after either infection with retroviral vectors or transfection with plasmids, showed a 50% reduction in both fructose 2,6-bisphosphate (Fru 2,6-P2) concentration and lactate production compared with control NIH-3T3 cells, indicating that these neo-expressing cells are less glycolytic. In addition, a marked decrease in the levels of mRNA for the procollagen 1 alpha and fibronectin genes was also observed in neo-expressing NIH-3T3 cells. This decrease was concomitant with an increase in the mRNA concentration of the endogenous c-myc gene. FTO-2B rat hepatoma cells also showed modifications in gene expression when the neo gene was introduced by stable transfection or infection. In these cells an increase in both P-enolpyruvate carboxykinase (PEPCK) and tyrosine aminotransferase (TAT) mRNA was observed. These results suggest that neo gene expression may induce changes in the cells, which should be considered when neo-selected cells are used to deliver specific genes in different therapy approaches and in embryo manipulation.

Overexpression of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase in transgenic mice causes hepatic hyperketogenesis

Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMG-CoA synthase) is a key enzyme in the ketone body pathway. To determine its role in the regulation of liver ketogenesis, transgenic mice expressing a P-enolpyruvate carboxykinase/HMG-CoA synthase chimeric gene have been obtained. An increase in the concentration of mitochondrial HMG-CoA synthase mRNA was detected in these mice, which was associated with a 3-fold increase in HMG-CoA synthase activity in liver mitochondrial extracts. Transgenic mice were normoglycemic and had normal levels of plasma triglycerides and lower free fatty acids. However, the plasma concentration of ketone bodies was about three times higher in transgenic mice than in control animals. Hepatocytes in primary culture from transgenic mice expressed the chimeric gene in a regulated manner and showed a 3-fold increase in beta-hydroxybutyrate and acetoacetate concentrations in the medium. This animal model thus shows that the overexpression of mitochondrial HMG-CoA synthase causes ketone body overproduction, suggesting that this enzyme may be a regulatory step in liver ketogenesis.

Cloning of a gene involved in rRNA precursor processing and 23S rRNA cleavage in Rhodobacter capsulatus

In Rhodobacter capsulatus wild-type strains, the 23S rRNA is cleaved into [16S] and [14S] rRNA molecules. Our data show that a region predicted to form a hairpin-loop structure is removed from the 23S rRNA during this processing step. We have analyzed the processing of rRNA in the wild type and in the mutant strain Fm65, which does not cleave the 23S rRNA. In addition to the lack of 23S rRNA processing, strain Fm65 shows impeded processing of a larger 5.6-kb rRNA precursor and slow maturation of 23S and 16S rRNAs from pre-23S and pre-16S rRNA species. Similar effects have also been described previously for Escherichia coli RNase III mutants. Processing of the 5.6-kb precursor was independent of protein synthesis, while the cleavage of 23S rRNA to generate 16S and 14S rRNA required protein synthesis. We identified a DNA fragment of the wild-type R. capsulatus chromosome that conferred normal processing of 5.6-kb rRNA and 23S rRNA when it was expressed in strain Fm65.

Calcium-mobilizing effectors inhibit P-enolpyruvate carboxykinase gene expression in cultured rat hepatocytes

Incubation of primary cultures of hepatocytes from fed and fasted rats with calcium ionophore strongly decreased glucose production from pyruvate. Like insulin, calcium ionophore A23187, phenylephrine, vasopressin, and prostaglandins E2 and F2 alpha caused a significant reduction (50-60%) in basal concentrations of mRNA for P-enolpyruvate carboxykinase (PEPCK), the main regulatory enzyme of gluconeogenesis. Phenylephrine, prostaglandin E2 and calcium ionophore A23187 were also able to counteract the induction of PEPCK gene expression by Bt2cAMP. These effects were similar to those exerted by both vanadate and phorbol ester TPA. The decrease in extracellular calcium by the addition of the calcium-chelating agent EGTA to the incubation medium caused an increase in PEPCK mRNA levels. This effect was additive to that of Bt2cAMP and was counteracted by vanadate.

Comparative effects of velnacrine, tacrine and physostigmine on the twitch responses in the rat phrenic-hemidiaphragm preparation

1. Cholinesterase inhibitors potentiated twitch responses induced by nerve stimulation, with physostigmine more potent than tacrine and velnacrine. However, at higher concentrations, tacrine decreased twitch responses in a concentration-dependent manner. 2. Tacrine strongly depressed directly-induced twitch responses, whereas the other drugs had minimal effects. 3. Physostigmine was the most potent drug in reversal of tubocurarine-induced blockade, but its antagonism index was similar to those obtained with tacrine and velnacrine at higher concentrations. When evaluating their ability to reverse neomycin-induced blockade, all drugs exhibited a similar effect. 4. It is concluded that tacrine and velnacrine are less potent than physostigmine in potentiating skeletal neuromuscular transmission. Additionally, the blocking effects of tacrine could limit its therapeutic efficacy.

Vanadate treatment restores the expression of genes for key enzymes in the glucose and ketone bodies metabolism in the liver of diabetic rats

Oral administration of vanadate to diabetic streptozotocin-treated rats decreased the high blood glucose and D-3-hydroxybutyrate levels related to diabetes. The increase in the expression of the P-enolpyruvate carboxykinase (PEPCK) gene, the main regulatory enzyme of gluconeogenesis, was counteracted in the liver and the kidney after vanadate administration to diabetic rats. Vanadate also counteracted the induction in tyrosine aminotransferase gene expression due to diabetes and was able to increase the expression of the glucokinase gene to levels even higher than those found in healthy animals. Similarly, an induction in pyruvate kinase mRNA transcripts was observed in diabetic vanadate-treated rats. These effects were correlated with changes on glucokinase and pyruvate kinase activities. Vanadate treatment caused a decrease in the expression of the liver-specific glucose transporter, GLUT-2. Thus, vanadate was able to restore liver glucose utilization and block glucose production in diabetic rats. The increase in the expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCoAS) gene, the key regulatory enzyme in the ketone bodies production pathway, observed in diabetic rats was also blocked by vanadate. Furthermore, a similar pattern in the expression of PEPCK, GLUT-2, HMGCoAS, and the transcription factor CCAAT/enhancer-binding protein alpha genes has been observed. All of these results suggest that the regulation of the expression of genes involved in the glucose and ketone bodies metabolism could be a key step in the normalization process induced by vanadate administration to diabetic rats.

[The Prevalence of pain in hospitalized patients]

BACKGROUND

There are few studies evaluating the presence of pain in hospitalized patients. Different authors have suggested interest in epidemiological studies to establish the characteristics of pain at a hospitalary level. The present study was initiated to determine the prevalence of pain in acute and chronic patients admitted to hospital and to establish the relation of the pain with the prescription of analgesics.

METHODS

Pediatric, acute and chronic adult patients pertaining to a hospital in Sabadell (Barcelona) were included in the study. Patients from resuscitation, ICU, neonatology and the emergency wards were excluded. The variables studied were presence of pain and the existence of analgesic prescription. The first was determined by interview with the patient, while the second was obtained directly from the clinical history.

RESULTS

Fifty-five percent of the 217 adult patients with acute pathology manifest pain and in 45% of them total analgesics had been prescribed. The prevalence of pain was 61% among the 41 pediatric patients and 35% among the 98 adults with chronic disease. Prescription of analgesics was observed in 51 and 39%, respectively in the above groups of patients. The relation between the presence of pain and antialgic prescription was variable according to the groups. It must be emphasized that 50% of acute adult patients with pain did not have prescription of analgesics. Pain was present in all the pediatric patients with some analgesic prescribed. Sixty-eight percent of the chronic patients with prescribed analgesics also experienced pain.

CONCLUSIONS

The prevalence of pain in the hospital environment is high, not only in pediatric but also in adult and geriatric patients. The high number of patients who do not receive analgesics despite pain and those in whom the treatment does not totally eradicate the symptoms is of note. Analgesic therapy must acquire greater revelance in hospitalary assistance.

Glucose metabolism in transgenic mice containing a chimeric P-enolpyruvate carboxykinase/bovine growth hormone gene

Transgenic mice, containing the chimeric gene obtained by linking the promoter-regulatory region of P-enolpyruvate carboxykinase (PEPCK) gene to the bovine growth hormone structural gene (bGH), were used to investigate the long-term effects of bGH on glucose metabolism. Expression of the PEPCK/bGH gene was markedly enhanced by feeding a diet high in protein and inhibited by a high carbohydrate diet. All transgenic mice had normal levels of blood glucose but were hyperinsulinemic, indicating that they were insulin resistant. The glycogen synthase activity ratios in the muscle and liver of transgenic mice were lower than noted for control animals, and remained unchanged in liver after feeding a standard high carbohydrate or a high protein diet. Similar effects were detected in the activity of glycogen phosphorylase, except that a high carbohydrate diet activated this enzyme in the liver. The activation of glycogen phosphorylase in both muscle and liver correlated with the expression of their genes. These animals had a significant content of glycogen and glucose 6-phosphate, which was related to the levels of glucokinase mRNA in the liver. The concentration of fructose 2,6-bisphosphate in the liver of all fed transgenic mice was lower than noted in livers from fed animals. In addition, a decrease in the hepatic expression of the endogenous genes for PEPCK, tyrosine aminotransferase (TAT), and the glucose transporter GLUT-2 was observed and directly correlated with the expression of bGH. Thus, bGH can control glucose metabolism in vivo, at least in part, by modifying the expression of several genes coding for proteins of importance in carbohydrate metabolism. Taken together, these results indicate a state of insulin resistance caused by chronic exposure of the animals to an elevated concentration of bGH.

[Hodgkin's disease and non-Hodgkin's lymphoma occurring simultaneously]

The simultaneous appearance of Hodgkin's disease and a non Hodgkin's lymphoma is very infrequent and has classically been considered as coincidental. Nevertheless, recent clinical observations suggest that neoplastic cells which lead to Hodgkin's disease are of lymphoid origin. The case of a "discordant" lymphoma formed by a laterocervical Hodgkin's disease and a large cell gastric lymphoma is presented. The coexistence of these two diseases, as herein presented, supports the lymphoid origin of Hodgkin's disease.

[Long-term survival in chronic myeloid leukemia: frequency and fundamental characteristics in a series of 100 patients]

PURPOSE

To analyse the frequency and the main clinico-haematologic characteristics of the patients with Ph'-positive chronic myelogenous leukaemia (CML) with long survival.

MATERIAL AND METHODS

Of a series of 100 patients with CML diagnosed in the chronic phase and treated in the conventional way at the "Farreras Valentí" School of Haematology between 1969 and 1982, and followed-up for at least 10 years, those surviving more that 8-10 years since the diagnosis were considered eligible for this study. Their clinico-haematological characteristics at diagnosis were compared to those of the remaining patients by means of the Student's t and Mann-Whitney's U tests, plus chi square with the Yates correction. The actuarial survival in the series was assessed according to the Kaplan and Meier method. The Sokal prognostic index was calculated in the longest survivors.

RESULTS

The median survival of the series was 45 months (range: 4-171). Ninety-one patients died, 2 are alive in chronic phase and in 7 others the follow-up has been lost in the chronic phase. Eight patients survived more than 10 years and 14 more than eight years. Of these, six were men and eight women, 10 were under 50 years of age, one-half lacked splenomegaly at diagnosis and only 2 had Ph' chromosome mosaicism. According to the Sokal prognostic index, six of these patients were in the low-risk group, four were of intermediate risk, and four others were in the high-risk group. None of them had aplasia due to busulphan during the follow-up. When comparing the initial features of the patients surviving 8-10 years with those of the remainders, only the presence of a lower percentage of blast-cells (p = 0.03) and a lower number of blasts in peripheral blood (p = 0.01) in the former achieved statistically significant difference.

CONCLUSIONS

These findings confirm the difficulty in identifying the CML patients with expected long survival at diagnosis. High numbers of cases must be analysed in order to attain definite conclusions in this regard.

Epidermal growth factor inhibits phosphoenolpyruvate carboxykinase gene expression in rat hepatocytes in primary culture

Epidermal growth factor (EGF) decreased the basal, and blocked the dibutyryl cyclic AMP (Bt2cAMP)-induced, expression of P-enolpyruvate carboxykinase (GTP) (PEPCK) and tyrosine aminotransferase (TAT) genes in both rat hepatocytes in primary culture and the FTO-2B hepatoma cell line. Treatment of hepatocytes with EGF in combination with phorbol ester (TPA) resulted in an additive decrease of PEPCK mRNA levels. Overnight pretreatment of hepatocytes with TPA, which is known to downregulate protein kinase C, abolished the TPA and reduced the EGF-mediated inhibition of PEPCK gene expression. These results suggested that EGF caused its effect, at least in part, through protein kinase C.

Lithium restores glycogen synthesis from glucose in hepatocytes from diabetic rats

In hepatocytes incubated in the presence of 20 mM glucose, strong stimulation of glycogen synthesis by LiCl was observed in cells from both normal and streptozotocin-induced diabetic rats. This stimulation was concentration- and time-dependent, and it was related to an increase in the glycogen synthase activity ratio. No effects of LiCl on glycogen phosphorylase activity were detected under these conditions. When hepatocytes were incubated with LiCl and insulin together, an additive effect on glycogen synthesis from glucose was observed. However, when hepatocytes were incubated in the presence of gluconeogenic precursors, such as lactate and pyruvate, and then with LiCl, no effect on glycogen accumulation was observed. Under these conditions, simultaneous activation of glycogen synthase and glycogen phosphorylase occurred. These results indicate that lithium ions, like insulin, are able to stimulate glycogen synthesis from glucose in diabetic rat hepatocytes, although the mechanisms of action of the two effectors on hepatic glycogen metabolism are probably different.

[Bartter's syndrome: variability and clinical course]

The clinical, hydroelectrolytical and hormonal features, as well as the treatment of 3 patients with Bartter's syndrome are analyzed. The patients consulted due to severe hypokalaemia with little clinical expression (paresthesiae, carpopedal spasms, polyuria, polydipsia and/or weakness). All had normal blood pressure, hypokalemia, hyperreninaemic hyperaldosteronism and a decrease in the fractional distal chloride reabsorption; hyperuricaemia was observed in two cases and hypomagnesemia in one. Treatment with oral potassium supplements and indomethacin managed to raise serum K to around the lower limit of the normal range. However, the tubular defect and hyperreninaemic hyperaldosteronism persisted. The urinary excretion of prostaglandin E2 was normal in both the patients in whom it was measured. Given the minimal clinical expression of hypokalemia despite the difficulty in correcting it, it is probable that this syndrome often remains unrecognized.