Acid phosphatase isoenzymes in Gaucher's disease

Acid phosphatase (EC 3.1.3.2) isoenzyme profiles of extracts of splenic tissue and serum from patients with Gaucher's disease were measured by a mini-column ion-exchange chromatographic method [Clin. Chem., 23, 000 (1977)]. Diagnosis of Gaucher's disease in the five patients studied was confirmed by demonstrating decreased (2.3 to 4.1% of normal) glucocerebrosidase activity in the spleen. With p-nitrophenyl phosphate as substrate, increased acid phosphatase activity (three-to eight-fold normal) was demonstrated in spleen tissue from Gaucher;s disease patients; isoenzyme profiles by the ion-exchange column technique showed acid phosphatase isoenzyme 5 to be the predominant isoenzyme. Comparison of acid phosphatase isoenzyme profiles from patients with Gaucher's disease and prostatic carcinoma revealed distinct differences in the activities of isoenzymes 2 and 5. The isoenzyme-5 measurement thus appears to provide a diagnostic test for Gaucher's disease that can be done reapidly and easily in the routine clinical chemistry laboratory.     

Clinical characteristics of type I Gaucher's disease in Spain. Preliminary results of national survey. Spanish Group on Gaucher's Disease

BACKGROUND: To know the incidence and distribution of Gauchers's disease (GD) in Spain, a national inquiry was carried out in order to analyze the clinical, genetic and evolutive features of these patients. PATIENTS AND METHODS: A questionnaire including demographic, clinical, diagnostic, biological, radiological and evolutive data was sent to the hospitals. Each case with a presumptive diagnosis was considered a "censored patient". The cases without enzymatic or genetic diagnosis were studied in a reference laboratory (the same for all the samples). The Zimran's Severity index was employed to evaluate the clinical status. The enzymatic activity of acid beta-glucosidase was studied in cellular extracts of peripheral blood granulocytes by a fluorescent method using an artificial substrate (methyl-umbeliferyl-beta-deglycoside). The characterization of the mutations of the glucosidase gene was determined by PCR molecular analysis in the samples of DNA studying the mutations: N370S, L444P, 84GG and IVS2+1. RESULTS: Seventy five patients were censored; in 48 the inquiry was completed. These patients belonged to 54 families. The mean age at diagnosis was 24.7 years, being the M/F distribution 16/32. The illness was asymptomatic in 13.3%, visceral disease was present in 83.3% of patients and bone disease in 70.8%. The 45.8% of patients had hemoglobin levels < 110 g/l, 35.4% low leucocyte count < 4,0 x 10(9)/l and 77.0% low platelet count < 150 x 10(9)/l. High acid phosphatase levels were observed in 100% of cases and in 34.7% biochemical hepatic dysfunction was observed. The test for acid glucosidase showed a marked decrease in enzymatic activity. In 71% of the patients morphologic documentation (splenic or hepatic tissue, bone marrow biopsy or aspirates) was performed. The most frequent mutations observed were N370S (47.7% of the alleles detected), and L444P (24.4%). In 18.7% of the cases the disease was stable or slightly progressive, in 27.0% the spleen was removed between 1-14 years of the being made and 45.8% were put onto an alglucerase trial. CONCLUSIONS: The incidence of GD in Spain is at present lower that the previously reported for other european countries. The clinical features are not different except in the case of bone disease, less frequent in our cases, probably limited by the absence of MR. The pattern of distribution of mutation is also similar.     

Neuronopathic forms of Gaucher's disease

Neuronopathic Gaucher patients may have a wide variety of clinical manifestations and natural history, and can present with a range of degrees of severity of systemic disease and neurological deficit. The brain pathology of these patients has been well described, but the mechanism by which glucocerebrosidase deficiency leads to neuronal dysfunction is not yet understood. The almost 20 different mutations of the glucocerebrosidase gene that have been described in Type 2 and 3 Gaucher patients poorly predict the phenotype of individual patients. Enzyme replacement therapy (ERT), often at high doses, has been shown to reverse most of the systemic manifestations of this disease, but can rarely reverse the neurological deficits. Therefore, other forms of treatment, such as gene therapy or a more efficient and direct enzyme delivery to neurons, are being devised.     

Plasma and metabolic abnormalities in Gaucher's disease

An overview of the most important plasma abnormalities that can be found in Gaucher's disease is presented in this chapter. Attention is focussed on their practical applications and possible clinical relevance. In addition, the result of studies on metabolic alterations in Gaucher's disease are reviewed.     

Non-Hodgkin's lymphoma associated with Gaucher's disease

Gaucher's disease is an uncommon disorder which has been reported to be associated with an increased risk of lymphoproliferative disorders, including Non-Hodgkin's lymphoma (NHL). A new instance of such an association is described here. This was a 58 year-old-patient with adult type I Gaucher's disease who, one and a half year after the above diagnosis, presented with supraclavicular lymphadenopathy, massive splenomegaly, prominent retroperitoneal lymphadenopathy and increased serum LDH levels. This led to the diagnosis of large-cell NHL of B-cell type, successfully treated with chemotherapy. The previously published cases of Gaucher's disease associated with NHL as well as the possible mechanisms leading to this association are reviewed here.     

Prenatal ultrasound findings in a fetus diagnosed with Gaucher's disease (type 2) at birth

A 26-year-old woman with no significant history was found to have a fetus with hepatosplenomegaly and neurological abnormalities in utero on ultrasound. The baby was found to have a severe clinical manifestation of type 2 Gaucher's disease.     

Regulation of endogenous glucose production by glucose per se is impaired in type 2 diabetes mellitus

We examined the ability of an equivalent increase in circulating glucose concentrations to inhibit endogenous glucose production (EGP) and to stimulate glucose metabolism in patients with Type 2 diabetes mellitus (DM2). Somatostatin was infused in the presence of basal replacements of glucoregulatory hormones and plasma glucose was maintained either at 90 or 180 mg/dl. Overnight low-dose insulin was used to normalize the plasma glucose levels in DM2 before initiation of the study protocol. In the presence of identical and constant plasma insulin, glucagon, and growth hormone concentrations, a doubling of the plasma glucose levels inhibited EGP by 42% and stimulated peripheral glucose uptake by 69% in nondiabetic subjects. However, the same increment in the plasma glucose concentrations failed to lower EGP, and stimulated glucose uptake by only 49% in patients with DM2. The rate of glucose infusion required to maintain the same hyperglycemic plateau was 58% lower in DM2 than in nondiabetic individuals. Despite diminished rates of total glucose uptake during hyperglycemia, the ability of glucose per se (at basal insulin) to stimulate whole body glycogen synthesis (glucose uptake minus glycolysis) was comparable in DM2 and in nondiabetic subjects. To examine the mechanisms responsible for the lack of inhibition of EGP by hyperglycemia in DM2 we also assessed the rates of total glucose output (TGO), i.e., flux through glucose-6-phosphatase, and the rate of glucose cycling in a subgroup of the study subjects. In the nondiabetic group, hyperglycemia inhibited TGO by 35%, while glucose cycling did not change significantly. In DM2, neither TGO or glucose cycling was affected by hyperglycemia. The lack of increase in glucose cycling in the face of a doubling in circulating glucose concentrations suggested that hyperglycemia at basal insulin inhibits glucose-6-phosphatase activity in vivo. Conversely, the lack of increase in glucose cycling in the presence of hyperglycemia and unchanged TGO suggest that the increase in the plasma glucose concentration failed to enhance the flux through glucokinase in DM2. In summary, both lack of inhibition of EGP and diminished stimulation of glucose uptake contribute to impaired glucose effectiveness in DM2. The abilities of glucose at basal insulin to both increase the flux through glucokinase and to inhibit the flux through glucose-6-phosphatase are impaired in DM2. Conversely, glycogen synthesis is exquisitely sensitive to changes in plasma glucose in patients with DM2.     

The role of insulin and glucagon in the regulation of basal glucose production in the postabsorptive dog

The aim of the present experiments was to determine the role of insulin and glucagon in the regulation of basal glucose production in dogs fasted overnight. A deficiency of either or both pancreatic hormones was achieved by infusin somatostatin (1 mug/kg per min), a potent inhibitor of both insulin and glucagon secretion, alone or in combination with intraportal replacement infusions of either pancreatic hormone. Infusion of somatostatin alone caused the arterial levels of insulin and glucagon to drop rapidly by 72+/-6 and 81+/-8%, respectively. Intraportal infusion of insulin and glucagon at rates of 400 muU/kg per min and 1 ng/kg per min, respectively, resulted in the maintenance of the basal levels of each hormone. Glucose production was measured using tracer (primed constant infusion of [3-3H]glucose) and arteriovenous difference techniques. Isolated glucagon deficiency resulted in a 35+/-5% (P less than 0.05) rapid and sustained decrease in glucose production which was abolished upon restoration of the plasma glucagon level. Isolated insulin deficiency resulted in a 52+/-16% (P less than 0.01) increase in the rate of glucose production which was abolished when the insulin level was restored. Somatostatin had no effect on glucose production when the changes in the pancreatic hormone levels which it normally induces were prevented by simultaneous intraportal infusion of both insulin and glucagon. In conclusion, in the anesthetized dog fasted overnight; (a) basal glucagon is responsible for at least one-third of basal glucose production, (b) basal insulin prevents the increased glucose production which would result from the unrestrained action of glucagon, and (c) somatostatin has no acute effects on glucose turnover other than those it induces through perturbation of pancreatic hormone secretion. This study indicates that the opposing actions of the two pancreatic hormones are important in the regulation of basal glucose production in the postabsorptive state.     

Endothelin-1 inhibits basal and human chorionic gonadotrophin-stimulated progesterone production

Endothelin-1 (ET-1) is a peptide classically produced by endothelial cells and known for its powerful vasoconstrictor activity. However, recent data suggest an involvement of ET-1 also in reproductive function. This study was designed to examine the possible presence and role of ET-1 in human luteal cells. Purified luteal cells were incubated for different times with ET-1 (10(-9)-10(-6) M) or ET-3 (10(-9)-10(-6)) alone or associated with human chorionic gonadotrophin (HCG) (100 ng/ml). Both basal and HCG-induced progesterone production were significantly reduced by ET-1 at all examined times whereas preincubation of luteal cells with BQ485 (10(-9)-10(-6) M), an ET-A receptor antagonist, prevented the inhibitory effect of ET-1. Conversely, no effect on progesterone synthesis was observed when ET-3 was added to the cultures. Luteal cells were then incubated for 24 h with phorbol 12-myristate-13 acetate (PMA) (100 ng/ml), an activator of protein kinase C. Inhibition of progesterone synthesis by PMA was similar to that induced by ET-1 alone. This study demonstrates that ET-1 negatively affects, at physiological concentrations, basal and HCG-induced progesterone synthesis. These effects seem to be exerted through the ET-A receptors and the protein kinase C pathway. Conversely, ET-3 was not able to influence human luteal steroidogenesis.     

Gaucher's disease: clinical features and natural history

Gaucher's disease is an inherited disorder characterized by pathological storage of glycolipid in mononuclear phagocytes: it is a multi-system disease associated with striking variation in its clinical manifestations, severity and course. Although molecular analysis of the glucocerebrosidase gene in patients with Gaucher's disease has permitted broad correlations between genotype and phenotype to be made, with few exceptions genetic variation at this locus does not allow confident prediction of clinical phenotype or prognosis. Partial deficiency of glucocerebrosidase is associated principally with parenchymal disease of the liver, spleen, bone marrow and, in severe cases, the lung, in non-neuronopathic, Type 1, Gaucher's disease: here storage material in macrophages originates from turnover of exogenous glycolipids. Severe deficiency of glucocerebrosidase caused by disabling mutations is additionally associated with neurological manifestations that in part reflect a failure to degrade endogenous neuronal glycosphingolipids, the so-called neuronopathic, Type 2 and Type 3 disease categories. Here we describe the clinical features, complications and natural history principally of Type 1 Gaucher's disease: emphasis is placed on emerging pulmonary, osseous and other manifestations of obscure pathogenesis that respond poorly to enzyme-replacement therapy.     

Increased plasma IGF-1 levels but lack of changes in adipocyte glucose transport in weanling rats with dorsomedial hypothalamic nucleus lesions 1 year after lesion production

Experimental destruction of the dorsomedial hypothalamic nuclei (DMN) in weanling rats exerts an antiaging effect by preventing microalbuminuria and kidney lesions both 1 month and 1 year after lesion production. In the present study we report further on antiaging effects of DMN lesions (DMNL) by measuring glucose transport into adipocytes and plasma levels of insulin-like growth factors 1 and 2 (IGF-I, IGF-II). Male and female weanling Sprague-Dawley rats received bilateral electrolytic lesions in the DMN; sham-operated animals served as controls (SCON). The rats were maintained for 1 year and food intake was measured 3 weeks after surgery and 3 weeks prior to sacrifice. As expected, DMNL resulted in profound reductions of body weight and food intake, with male DMNL rats showing higher body weights and body weight gains than their female counterparts. The same was true of the respective SCON. In male DMNL rats, carcass fat in absolute terms was significantly reduced vs. SCON, but it was comparable among all groups when expressed in percent. Lean body mass (LBM), although significantly reduced in absolute terms in DMNL rats vs. SCON, was, however, significantly higher in male DMNL vs. SCON when expressed in percent, but not in females. LBM laid down per food energy taken in was higher in DMNL rats of both sexes than in their respective SCON. Efficiency of food utilization was normal in male DMNL vs. male SCON but was higher in female DMNL vs. SCON. Both male and female DMNL rats had significantly higher plasma IGF-1 concentrations than their respective SCON, and male DMNL rats had higher values than female DMNL rats. Plasma concentrations of IGF-II were significantly higher in DMNL vs. SCON, but only in females. Under both basal and insulin-stimulated conditions, DMNL rats had normal 3-0-methylglucose flux in adipocytes from epididymal fat pads vs. SCON. However, DMNL and SCON responded similarly to the stimulating effect of insulin. Although one-year-old rats may not be considered "aged", we do consider the observed lack of a drop in plasma IGF-I levels that occurs with aging as an "anti-aging" effect of DMN lesions.     

Increased calcium buffering in basal forebrain neurons during aging

Increased calcium buffering in basal forebrain neurons during aging. J. Neurophysiol. 80: 350-364, 1998. Alterations of neuronal calcium (Ca2+) homeostasis are thought to underlie many age-related changes in the nervous system. Basal forebrain neurons are susceptible to changes associated with aging and to related dysfunctions such as Alzheimer's disease. It recently was shown that neurons from the medial septum and nucleus of the diagonal band (MS/nDB) of aged (24-27 mo) F344 rats have an increased current influx through voltage-gated Ca2+ channels (VGCCs) relative to those of young (1-4. 5 mo) rats. Possible age-related changes in Ca2+ buffering in these neurons have been investigated using conventional whole cell and perforated-patch voltage clamp combined with fura-2 microfluorimetric techniques. Basal intracellular Ca2+ concentrations ([Ca2+]i), Ca2+ influx, Ca2+ transients (Delta[Ca2+]i), and time course of Delta[Ca2+]i were quantitated, and rapid Ca2+ buffering values were calculated in MS/nDB neurons from young and aged rats. The involvement of the smooth endoplasmic reticulum (SER) was examined with the SER Ca2+ uptake blocker, thapsigargin. An age-related increase in rapid Ca2+ buffering and Delta[Ca2+]i time course was observed, although basal [Ca2+]i was unchanged with age. The SER and endogenous diffusible buffering mechanisms were found to have roles in Ca2+ buffering, but they did not mediate the age-related changes. These findings suggest a model in which some aging central neurons could compensate for increased Ca2+ influx with greater Ca2+ buffering.     

Increased striatal glucose consumption in Sydenham's chorea

Positron emission tomography and 18F-fluorodeoxyglucose were used to measure the regional cerebral glucose consumption in a 15-year-old choreatic girl with classical Sydenham's chorea shortly after the onset of hyperkinetic movements and 5 months later after chorea had resolved and in a 74-year-old hemichoreatic woman with long-standing hyperkinesia as a residuum of Sydenham's chorea in adolescence. Whereas cerebellar, thalamic, and cortical glucose consumption was within normal limits in both patients, lentiform and caudate glucose consumption was significantly increased in both hemispheres of the 15-year-old patient and in the hemisphere contralateral to the chorea in the 74-year-old patient. In the younger patient, striatal glucose consumption returned to normal after her hyperkinesia had disappeared with antibiotic therapy. The observation of an increase in striatal glucose consumption in Sydenham's chorea, in contrast to the decrease of this variable encountered in the vast majority of other choreatic disorders, leads to questioning the pathophysiology of chorea in humans and suggests the use of emission tomographic measurement of variables related to cerebral energy metabolism for differential diagnosis in choreatic disorders.     

Increased immunoreactive endothelin-1 in human transplant coronary artery disease

BACKGROUND: The pathogenesis of transplant coronary artery disease (TCAD) is unknown, but it is thought to derive from an interaction between immune and nonimmune factors, leading to smooth muscle cell proliferation and accumulation in the expanded neointima. Endothelin-1 (ET-1), a potent vasoconstrictor with mitogenic properties for vascular smooth muscle cells, has recently been demonstrated in native vessel atherosclerosis. The present study used immunohistochemistry to investigate the role of ET-1 in TCAD. METHODS AND RESULTS: ET-1 immunoreactivity and cellular localization were assessed in human coronary arteries with TCAD (n = 13) and in normal coronary arteries (n = 10) with single- and double-label immunohistochemistry. The intensity of immunostaining was determined by a semiquantitative method. Diffuse and intense ET-1 immunoreactivity was found in 11 of 13 patients with TCAD (85%), mainly in myointimal cells and, in lesser amounts, in macrophages and endothelial cells. In contrast, normal coronary arteries had only faint immunostaining localized to the endothelial layer. Mean semiquantitative grade was significantly higher in TCAD than in normal arteries (1.8 versus 0.7; P < .05). ET-1 was more frequently present in lipid-rich, atheromatous lesions than in lipid-poor, proliferative ones. Intimal neovessels consistently immunostained for ET-1. CONCLUSIONS: Immunoreactivity for ET-1 is significantly increased in TCAD, possibly as a result of stimulatory cytokines and growth factors that are upregulated in the posttransplant state. The results suggest a role for this mitogenic peptide in the pathogenesis of graft arteriosclerosis.