In vivo co-ordinated interactions between inhibitory systems to control glutamate-mediated hippocampal excitability

We present an overview of the long-term adaptation of hippocampal neurotransmission to cholinergic and GABAergic deafferentation caused by excitotoxic lesion of the medial septum. Two months after septal microinjection of 2.7 nmol alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA), a 220% increase of GABA(A) receptor labelling in the hippocampal CA3 and the hilus was shown, and also changes in hippocampal neurotransmission characterised by in vivo microdialysis and HPLC. Basal amino acid and purine extracellular levels were studied in control and lesioned rats. In vivo effects of 100 mm KCl perfusion and adenosine A(1) receptor blockade with 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) on their release were also investigated. In lesioned animals GABA, glutamate and glutamine basal levels were decreased and taurine, adenosine and uric acid levels increased. A similar response to KCl infusion occurred in both groups except for GABA and glutamate, which release decreased in lesioned rats. Only in lesioned rats, DPCPX increased GABA basal level and KCl-induced glutamate release, and decreased glutamate turnover. Our results evidence that an excitotoxic septal lesion leads to increased hippocampal GABA(A) receptors and decreased glutamate neurotransmission. In this situation, a co-ordinated response of hippocampal retaliatory systems takes place to control neuron excitability.

Clonal plasma cells from monoclonal gammopathy of undetermined significance, multiple myeloma and plasma cell leukemia show different expression profiles of molecules involved in the interaction with the immunological bone marrow microenvironment

The immunological bone marrow (BM) microenvironment plays a major role in controlling growth and survival of clonal plasma cells (PC); this might translate into different patterns of expression of molecules involved in immune responses on PC from different types of monoclonal gammopathies (MG). We have studied the expression of a group of nine such molecules on both BMPC and the plasma of 61 newly diagnosed MG patients (30 MG of undetermined significance (MGUS), 27 multiple myeloma (MM) and four plasma cell leukemia (PCL)) and five normal individuals. Clonal PC from all MG displayed significantly increased levels of CD56, CD86 and CD126, and decreased amounts of CD38 (P<0.001). Additionally, HLA-I and beta2-microglobulin were abnormally highly expressed in MGUS, while CD40 expression was decreased in MM and PCL (P<0.05). Interestingly, a progressive increase in the soluble levels of beta2-microglobulin was found from MGUS to MM and PCL patients (P=0.03). In contrast, all groups showed similar surface and soluble amounts of CD126, CD130 and CD95, except for increased soluble levels of CD95 observed in PCL. Overall, those phenotypic differences are consistent with increased antigen presentation and costimulatory capacities in MGUS, which progressively deteriorate in malignant MG (MM and PCL).

Effect of a Simple Dose-Escalation Schedule on Tramadol Tolerability

OBJECTIVE

To assess the effect of a very simple dose-escalation schedule on tramadol tolerability in clinical practice. This schedule consists of starting treatment with sustained-release tramadol 50mg twice daily, and escalating the dose around 7 days later to 100mg twice daily.

METHODS

Data from 1925 outpatients with non-malignant chronic pain were collected in this multicentre, prospective, comparative, non-randomised, open, observational study.

RESULTS

A total of 1071 patients (55.6%) were included in the dose-escalation group (50mg group) and 854 patients (44.4%) in the control group (sustained-release tramadol 100mg twice daily; 100mg group). The proportion of patients who interrupted tramadol treatment due to the occurrence of adverse reactions was significantly lower in the 50mg group (5.6%) than in the 100mg group (12.6%) [p = 0.001]. In line with this, the proportion of patients who experienced at least one adverse reaction was significantly lower in the 50mg group (18.4%) than in the 100mg group (30.4%) [p = 0.001] and, interestingly, the two most frequently reported adverse reactions, nausea and dizziness, were found with a significantly lower frequency in the 50mg group (p < 0.001). Multivariate analysis showed that the risk of safety-related treatment cessations was 2.3 times higher in the 100mg group than in the 50mg group, and 2.2 times higher in females than in males. The two treatments were equally effective in reducing pain intensity (p = 0.121), measured as a reduction in pain score obtained by means of a visual analogue scale.

CONCLUSION

The instauration of tramadol treatment, starting with sustained-release 50mg capsules twice daily and escalating the dose some days later to 100mg twice daily, was shown to be an effective and easy way to improve tramadol tolerability in clinical practice, whilst maintaining its analgesic efficacy.

Putative glucosensing property in rat and human activated microglia

Microglial cells involved in the pathogenesis of many neurodegenerative diseases acquire the features of cytotoxic and phagocytic cells in response to certain pathogens and inflammatory signals. K(ATP) channels are energy sensors of ATP availability that link the cell's metabolic state to its membrane excitability. In pancreatic beta cells, they promote glucose-dependent insulin secretion, and in neurones, hyperpolarization that protects against hypoxic damage. This study analyses activated microglia in an in vivo rat neurodegenerative model based on acute hippocampal glutamate receptor overactivation and in postmortem samples from patients with Alzheimer's disease. We demonstrate that in activated microglia the K(ATP) channel components SUR-1 or SUR-2 are present together with glucokinase. Our results indicate that, according to glucose availability, these channels may modify microglia membrane potential. The functional relevance of these channels is seen as a new mechanism modulating the effects of external signals on microglia.

Epidemiology of chronic inflammatory bowel disease in the Northern area of Huelva

OBJECTIVE

To know the different epidemiologic aspects of chronic inflammatory bowel disease (IBD) in the Northern area of the province of Huelva.

MATERIAL AND METHODS

we carried out a retrospective (1980-1996) and prospective (1996-2003) study of all patients diagnosed with IBD in the Northern area of Huelva, with 77,856 inhabitants. The distribution of Crohn s disease (CD) and ulcerative colitis (UC) was analyzed, as well as sex, age and smoking habit at the time of diagnosis, familial aggregation, appendicectomy rate, phenotype (anatomical site and clinical types), extraintestinal manifestations, and immunosuppressive therapy or surgical requirements.

RESULTS

70 patients with IBD were studied, 40 with UC and 30 with CD. Sex distribution was 39 (55.7%) males (55% with CD vs 56.6% with UC; NS) and 31 (44.3%) females (45% with CD vs 43.3% with UC; NS). Mean age at presentation was 44.7 +/- 19.32 years in UC vs 32.3 +/- 16.43 in CD; p < 0.001. Familial association was 7.1%. Previous appendicectomy was referred in 2.5% of patients with UC vs 36.7% of those with CD (p < 0.001), and the percentage of smokers was also higher in CD 66.7% vs CU 12.5% (p < 0.001). Anatomical site in UC was: proctitis, 20%; proctosigmoiditis/left colon, 42.5%; extensive colitis, 25%; and pancolitis, 12.5%; in CD was: terminal ileum, 43.3%; colon, 20%; and ileo-colon, 36.7%. The disease patterns were: inflammatory 56.7%, obstruction 26.7%, and fistulization 16.7%. Extraintestinal manifestations were diagnosed in 7.5% of patients with UC vs 16.6% patients with CD; surgery was performed in one patient with UC vs 10 with CD, and one patient with UC required immunosuppressive treatment vs 12 with CD. A multivariant analysis showed that younger age and smoking habit were risk factors for CD vs advanced age in UC, in which case, the smoking habit was a protective factor. The mean incidence rate of IBD starting from 1996 and expressed in cases/100,000 inhabitants/year was 5.2 for UC and 6.6 for CD.

CONCLUSIONS

The mean incidence of UC in our area was 5.2 cases/100,000/inhabitants/year, and 6.6 for CD. Patients presenting with CD are diagnosed at a significantly younger age that those with UC; the smoking habit is a risk factor for CD while it protects from UC. The characteristics of IBD in our geographical area do not differ substantially from those in other regions of Spain.

Nonfatal splenic haematoma and pancytopenia in an ass

This report describes a case of nonfatal idiopathic splenic haematoma and pancytopenia in a female ass, a condition that has not been previously reported in this species. A 12-year-old female ass weighing 225 kg was presented with signs of anorexia, depression and prominent abdominal distension. At the onset of clinical signs there was evidence of anaemia, leucopenia and thrombocytopenia. A large mass was palpated per rectum. The mass was confluent with the spleen and extended across the entire width of the abdomen. Percutaneous transabdominal ultrasonography and laparoscopy under general anaesthesia confirmed the diagnosis of splenic haematoma. The ass was treated initially with intravenous polyionic fluids; vitamins, trace elements and aminoacids; clanobutin; and penicillin and gentamicin, and was transfused with whole blood. After 5 days of hospitalisation the ass appeared brighter, and after 10 days the animal was discharged to recuperate at pasture. Six months later the animal's demeanour and appetite had improved. Repeat ultrasonographic examination showed persistence of the mass, but its thickness had decreased by 2 to 3 cm. A small mineralised area suggesting organisation of the haematoma was also detected. The haematological parameters had returned to normal values and the ass was clinically normal.

In vivo neuroprotective adaptation of the glutamate/glutamine cycle to neuronal death

Synaptic increase of glutamate level, when not coupled to a heightened energy production, renders neurons susceptible to death. Astrocyte uptake and recycling of synaptic glutamate as glutamine is a major metabolic pathway dependent on energy metabolism, which inter-relationships are not fully understood and remain controversial. We examine how the glutamate-glutamine cycle and glucose metabolism are modified in two in vivo models of severe and mild brain injury. Graded reductions of glutaminase, the glutamate synthetic enzyme, were evidenced combined with increases in glutamine synthetase, the inactivating glutamate enzyme. Increased lactate dhydrogenase (LDH) activity was only present after a more severe injury. These results indicate an in vivo adaptation of the glutamate-glutamine cycle in order to increase the net glutamine output, reduce glutamate excitotoxicity, and avoid neuronal death. We conclude that the graded modification of the glutamate-glutamine correlation and neuronal lactate availability may be key factors in the apoptotic and necrotic neuronal demise, whose control may prove highly useful to potentiate neuronal survival.

The Clinical Global Impression-Schizophrenia scale: a simple instrument to measure the diversity of symptoms present in schizophrenia

OBJECTIVE

To describe the development and validation of the Clinical Global Impression-Schizophrenia (CGI-SCH) scale, designed to assess positive, negative, depressive and cognitive symptoms in schizophrenia.

METHOD

The CGI-SCH scale was adapted from the CGI scale. Concurrent validity and sensitivity to change were assessed by comparison with the Positive and Negative Symptom Severity (PANSS) and Global Assessment of Functioning (GAF) scales. To evaluate inter-rater reliability, all patients were assessed by two clinicians.

RESULTS

Symptoms were assessed in 114 patients. Correlation coefficients between the CGI-SCH and the GAF and PANSS scores were high (most above 0.75), and were highest for positive and negative symptoms. Reliability was substantial (intraclass correlation coefficient, ICC > 0.70) in all but one dimension (depressive dimension, ICC = 0.64).

CONCLUSION

The CGI-SCH scale is a valid, reliable instrument to evaluate severity and treatment response in schizophrenia. Given its simplicity, brevity and clinical face validity, the scale is appropriate for use in observational studies and routine clinical practice.

[Treatment of allergy to mushrooms]

The treatment of patients with respiratory allergy is based on environmental control measures, pharmacological and immunotherapy treatment. The third cause of allergic respiratory disease in our environment is mushrooms, the most frequently involved being the Alternaria class. However, due to the great difficulties in their diagnosis and specific treatment, there are few controlled studies on immunotherapy with mushroom extracts. A clinical test was carried out with a suitable, biologically standardized extract for the diagnosis and treatment of patients allergic to Alternaria. A second phase determined the maximum tolerated dosage of this extract administered through immunotherapy, in depot preparation and in conventional dosage, which was 0.1 mg/ml of Alt a I. This dosage was established as the maintenance dosage in the following phase (double blind test controlled with placebo), in which the efficacy and safety of the immunotherapy with this extract was determined, administered in immunotherapy to the mentioned maintenance dosage, to 28 patients with rhinitis and/or asthma due to allergy to Alternaria. All the patients reached the pre-established maintenance dosage of 1670 BSU. The treatment proved efficient, producing an improvement in the symptoms, respiratory function, subjective evaluation of patient and doctor, and severity of the disease. The immunological response supported the clinical efficacy, with an increase in the IgG and a fall in the IgE over the course of the study. Tolerance to the treatment was excellent, with only two light systemic reactions registered in the 711 dosages administered (0.28% reactions/dosages administered).

MAO-A and MAO-B localisation in human lung and spleen

Localisation of MAO-A and -B in human lung and spleen was studied by immunohistochemistry. The primary antibodies used were mouse monoclonal anti-human MAO-A (6G11/E1) and anti-human MAO-B (3F12/G10/2E3). Samples of lung and spleen were obtained from 6 routine autopsy cases. Both immunoreactivities showed a homogeneous distribution in lung, where all cell types had both MAO-A and -B staining. In spleen MAO-A and -B showed a very weak immunoreactivity, which was restricted to smooth muscle cells and reticular cells of the white pulp. These data represent the most comprehensive study of MAO-A and -B localisation in the two tissues.

Initial bacterial colonization in patients admitted to a respiratory intensive care unit: bacteriological pattern and risk factors

BACKGROUND

Colonization is an important risk factor for consecutive infection, but little is known about incidence and initial pattern on admission to respiratory intensive care units (RICU).

OBJECTIVE

To study the bacterial colonization during the first 24 h after admission to a RICU.

METHODS

Endotracheal aspirates, gastric juice, and pharyngeal and rectal swabs of 55 consecutive patients were cultured (45 men, age 66 +/- 14 years, APACHE II 20.1 +/- 5.6, no parenchymal infection). All samples were taken within the first 24 h after admission to a RICU. Potentially pathogenic microorganisms were grouped as community (c-PPM) and hospital acquired (h-PPM), and risk factors for colonization of each body site as well as for overall colonization (all sites excluding rectum) were identified by logistic regression analysis.

RESULTS

The trachea was colonized in 18% of the intubated patients with c-PPMs and in 11% with h-PPMs. Candida spp. were the most frequent c-PPMs isolated from trachea, pharynx, and stomach (excluding rectal swabs), and Pseudomonas aeruginosa was the most frequently isolated h-PPM in trachea. The incidence of overall colonization was 49% for c-PPMs (predominantly Escherichia coli) and 18% for h-PPMs (predominantly P. aeruginosa). Admission to the hospital > or = 48 h before ICU admission was an independent risk factor of colonization with h-PPMs in univariate (33 vs. 7%, p = 0.015) and multivariate analyses (odds ratio 7.2, 95% CI 1.4-38.3; p = 0.0197).

CONCLUSIONS

Colonization of the trachea with c-PPMs was already present in every 5th and with h-PPMs in every 10th intubated patient during the first 24 h of RICU admission even in the absence of parenchymal infections. Hospitalization more than 48 h prior to RICU admission was a risk factor of colonization with h-PPMs.

Cellular localization of monoamine oxidase A and B in human tissues outside of the central nervous system

We studied the localization of monoamine oxidase (MAO) A and B in human heart, liver, duodenum, blood vessels and kidney by immunohistochemistry. The primary antibodies used were mouse monoclonal anti-human MAO-A (6G11/E1) and anti-human MAO-B (3F12/G10/2E3). Samples were obtained from six routine autopsy cases and fixed in 2% paraformaldehyde. All cardiomyocytes and hepatocytes showed MAO-A and MAO-B immunoreactivity. In the duodenum, both immunoreactivities were present in all cells of the villi, Lieberkühn crypts, muscularis mucosae and muscular layers, whereas Brunner glands were devoid of MAO-A and MAO-B staining. Endothelial cells of lymphatic vessels showed MAO-A but no MAO-B immunoreactivity, whereas arteries and veins presented MAO-A and MAO-B staining in muscular layers and fibroblasts but not in endothelial cells. In the kidney, renal tubuli showed MAO-A and MAO-B immunoreactivities, whereas collecting ducts and the Bowman's capsule showed only MAO-A staining. These data represent the first study of the cellular distribution of MAO-A and MAO-B in these human tissues. They show that both enzymes have a widespread distribution in the human body with a matching pattern in many, but not all tissues, and with strong differences from the pattern of distribution in rodents.

Increase in AMPA receptors in aged memory-impaired rats is not associated with increase in monoamine oxidase B levels

Aged rats may be behaviorally classified as either cognitively impaired or unimpaired based upon their performance in the Morris water maze task. In aged Long-Evans rats, emergence of functional deficits has been related to the increase in the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subtype in most hippocampal subfields, not observed in other brain structures. As AMPA receptors expressed in astrocytes may participate in the delayed and long-term glial response to injury, we investigated whether astrocytes participate in the increase of AMPA receptor observed in these aged rats. To this end, distribution of monoamine oxidase B, used as an astroglial marker, was characterized by quantitative autoradiography in the hippocampus and septum of young adults (six months) and aged (24-25 months) rats using [3H]lazabemide. Specific binding to brain sections of young, aged unimpaired, and aged impaired animals were calculated densitometrically. Compared to young animals, all hippocampal subfields in the aged unimpaired group showed a significant age-related increased labeling, which was not present in the aged impaired group. This contrasts with the increased glial transcription described in this last group. We propose that increase in AMPA receptors in the aged memory-impaired animals may be related to an atypic astrocytic reactivity.

Efficacy and safety of dipyrone versus tramadol in the management of pain after hysterectomy: a randomized, double-blind, multicenter study

BACKGROUND AND OBJECTIVES

We assessed the efficacy and safety of dipyrone in comparison with tramadol in the relief of early postoperative pain following abdominal hysterectomy.

METHODS

A total of 151 women between 18 and 60 years of age undergoing abdominal hysterectomy during general anesthesia participated in a randomized, double-blind, controlled, multicenter study. Seventy-three patients received dipyrone and 78 received tramadol. Patients received an intravenous loading dose of the study drug immediately after operation followed by intravenous (IV) maintenance infusion and IV on-demand boluses up to a maximum number of predetermined doses/day of 8 g dipyrone and 500 mg tramadol. The duration of the study was 24 hours.

RESULTS

The mean (SD) number of boluses in the dipyrone group was 3.8 (2.4) and 3.5 (2.5) in the tramadol group (95% confidence interval, -0.455 to 1.175), and the percentage of patients requiring rescue IV morphine (dipyrone 26.9%, tramadol 26.8%) was not statistically significant. Other analgesic efficacy parameters, such as pain intensity differences, sum of pain intensity differences, pain relief assessed by the patient, or patients who required the maximum number of demand doses, were not different between treatment groups. A significantly higher percentage of adverse gastrointestinal effects was found in patients given tramadol (42.1%) than in patients given dipyrone (20.2%) (P <.05). Also, a significantly higher number of tramadol-treated patients required ondansetron to control nausea and vomiting at 1 hour (19% v 7%), 2 hours (26% v 11%), and 24 hours (46% v 29%) (P <.05) after surgery. Patients and the investigators reported similar tolerability for both study arms.

CONCLUSIONS

Dipyrone and tramadol showed similar efficacy for early pain relief after abdominal hysterectomy. Nausea and vomiting, possibly caused by the tramadol, occurred more frequently in those patients. In this group, the need of the antiemetic drug ondansetron was also higher.

Molecular characterization of acute myeloblastic leukemia according to the new WHO classification: a different distribution in Central-West Spain

BACKGROUND AND OBJECTIVES

Molecular analysis has contributed to the identification of several non-random chromosomal translocations, such as t(15;17), t(8:21), inv(16)/t(16;16) and 11q23 abnormalities, typically associated with acute myeloid leukemia (AML). The identification of these chromosomal abnormalities helps not only to define different AML subtypes with distinct prognoses and treatments but also to monitor the disappearance of malignant cells after treatment. Recent reports suggest that the frequency of these alterations may differ according to geographic distribution. However, most of these reports focus on just one or two genetic alterations, which may lead to some selection bias. Appropriate epidemiological studies should be based on unselected consecutive series of patients in which all relevant genes are simultaneously analyzed. The aim of the present study was to explore whether or not the incidence of genetic lesions in Spanish AML patients differs from that reported in other countries.

DESIGN AND METHODS

In a series of 145 consecutive un-selected adult patients with AML we simultaneously analyzed the presence of 4 genetic abnormalities, PML/RARalpha for t(15;17), AML1/ETO for t(8;21), CBFbeta/MYH11 for inv(16)/t(16;16) and rearrangements of the MLL gene for 11q23 abnormalities. AML were classified using the new World Health Organization (WHO) classification for hematologic malignancies. The techniques used were standardized according to the recommendations of the European BIOMED-1 Concerted Action.

RESULTS

The PML/RARalpha transcript was present in 34 patients (23.4%) (23 were bcr1, 2 bcr2 and 9 bcr3). The AML1/ETO fusion transcript was detected in only 2 cases (1.4%) both with M2 morphology, but 29 other cases with M2 morphology were negative. CBFbeta/MYH11 transcript was present in 9 cases (6.2%) eight of them displaying M4Eo morphology. Finally, 5 cases (3.5%) showed rearrangements of theMLL gene. Our results differ from those reported from the United States and North/Central Europe, particularly regarding the incidence of t(15;17) and t(8;21) translocations. In Spain the frequency of t(15;17) is higher while that of t(8;21) is lower.

INTERPRETATION AND CONCLUSIONS

These data add epidemiological information about geographic heterogeneity of such chromosome aberrations in AML and would contribute to the design of specific screening strategies adapted to the incidence in each country.

Tissue activity and cellular localization of human semicarbazide-sensitive amine oxidase

Semicarbazide-sensitive amine oxidase (SSAO), widely distributed in highly vascularized mammalian tissues, metabolizes endogenous and xenobiotic aromatic and aliphatic monoamines. To assess whether its physiological role in humans is restricted to oxidation, we used an immunohistochemical approach to examine the cellular localization of SSAO in human peripheral tissues (adrenal gland, duodenum, heart, kidney, lung, liver, pancreas, spleen, thyroid gland, and blood vessels) and also analyzed its subcellular localization. The results are in agreement with the specific activities also determined in the same samples and are discussed with reference to the tissue distribution of monoamine oxidase A and B. Together with the oxidative deamination of monoamines, SSAO cellular localization indicates that, in most human peripheral tissues, it might participate in the regulation of physiological processes via H(2)O(2) generation. (J Histochem Cytochem 49:209-217, 2001)

Perinatal human hypoxia-ischemia vulnerability correlates with brain calcification

Deregulation of intracellular calcium homeostasis is widely considered as one of the underlying pathophysiological mechanisms of hypoxic-ischemic brain injury. Whether this alteration can result in cerebral calcification was investigated in basal ganglia, cerebral cortex, and hippocampus of human premature and term neonates together with glial reaction. In all samples nonarteriosclerotic calcifications were observed, their number and size were area-specific and increased in term neonates. Basal ganglia always presented the highest degree of calcification and hippocampus the lowest, located mainly in the CA1 subfield. In all cases, neuronal damage was associated with astroglial reaction and calcium precipitates, with microglial reaction only in basal ganglia and cerebral cortex, and argues for the participation of excitatory amino acid receptors in hypoxia-ischemia damage. These data correlate with hypoxia-ischemia vulnerability in the perinatal period. The clinical relevance of these precipitates and the neuroprotective interest of non-NMDA receptor manipulation are discussed in the light of our results.

In vivo and in vitro effects of (p)ppGpp on the sigma(54) promoter Pu of the TOL plasmid of Pseudomonas putida

The connection between the physiological control of the sigma(54)-dependent Pu promoter of the TOL plasmid pWW0 of Pseudomonas putida and the stringent response mediated by the alarmone (p)ppGpp has been examined in vivo an in vitro. To this end, the key regulatory elements of the system were faithfully reproduced in an Escherichia coli strain and assayed as lacZ fusions in various genetic backgrounds lacking (p)ppGpp or overexpressing relA. Neither the responsiveness of Pu to 3-methyl benzylalcohol mediated by its cognate activator XylR nor the down-regulation of the promoter by rapid growth were affected in relA/spoT strains to an extent which could account for the known physiological control that governs this promoter. Overexpression of the relA gene [predicted to increase intracellullar (p)ppGpp levels] did, however, cause a significant gain in Pu activity. Since such a gain might be the result of indirect effects, we resorted to an in vitro transcription system to assay directly the effect of ppGpp on the transcriptional machinery. Although we did observe a significant increase in Pu performance through a range of sigma(54)-RNAP concentrations, such an increase never exceeded twofold. The difference between these results and the behavior of the related Po promoter of the phenol degradation plasmid pVI150 could be traced to the different promoter sequences, which may dictate the type of metabolic signals recruited for the physiological control of sigma(54)-systems.

Excitatory amino acids and neurodegeneration: a hypothetical role of calcium precipitation

Activation of excitatory amino acid (EAA) receptors can induce neurodegeneration by two major mechanisms of excitotoxicity, one related to the influx of Na(+), Cl(-) and water, and the other to the increase in intracellular calcium concentration ([Ca(2+)](i)). Thus, acute microinjection of EAAs in several areas of the central nervous system (CNS) has been used to produce neurodegenerative models. We studied the excitotoxic pattern associated with acute microinjection of AMPA in rat hippocampus, medial septum-diagonal band of Broca (MS-DBB), prefrontal cortex and retina. In all cases progressive neuronal loss, glial reaction and development of intra- and extracellular calcium concretions were observed. However, a CNS-area differential vulnerability was revealed, as shown by the specific atrophy of MS-DBB and its limited calcification. Whether calcium deposits are a defensive mechanism against the massive increment of free cytoplasmatic calcium is discussed on the basis of ultrastructural data and previous results.

Localization of monoamine oxidase A and B in human pancreas, thyroid, and adrenal glands

We studied monoamine oxidase (MAO) A and B localization in human pancreas, thyroid gland, and adrenal gland by immunohistochemistry. The primary antibodies used were mouse monoclonal anti-human MAO-A (6G11/E1) and anti-human MAO-B (3F12/G10/2E3). Samples were obtained from six routine autopsy cases and fixed in 2% paraformaldehyde. Exocrine pancreas showed a widespread distribution of MAO-A, whereas MAO-B was present only in centroacinar cells and epithelial cells of pancreatic ducts. In endocrine pancreas, MAO-A was observed in around 50% of islet cells, whereas MAO-B was less abundant and was restricted to the periphery of islets. Thyroid gland showed strong MAO-A immunoreactivity in all cell types and was MAO-B-negative. In adrenal gland, the capsule displayed MAO-A but not MAO-B immunoreactivity, whereas the cortex showed widespread MAO-A staining but was MAO-B-negative in interstitial cells. Finally, in the medulla only a few scattered cells showed either MAO-A or MAO-B immunoreactivity. To our knowledge, these data represent the first study of the cellular distribution of MAO-A and MAO-B in the three human tissues included.

Reliability of low-avidity IgG and of IgA in the diagnosis of primary infection by rubella virus with adaptation of a commercial test

The detection of IgA and low-avidity IgG and antibodies in serum is a potentially useful marker of recent infection by a microorganism. We studied the reliability of IgG avidity and presence of IgA for the diagnosis of recent acute infection by rubella virus. Low-avidity IgG (Avy-EIA test) was determined with a modified commercial test using 8 molar urea (indirect ELISA, DiaSorin, Italy) and IgA was determined with a homemade indirect ELISA test. Twenty-five patients with recent primary infection by rubella virus (group I) and 50 healthy subjects (group II) were studied. In group I low-avidity IgG varied between 100 and 0% (67.3+/-21.8%); IgA was present in 24 patients (96%). In group II low-avidity IgG varied from 50.4 to 0% (19.8+/-16.9%). IgA was present in 2 subjects (4%). The sensitivity of the Avi-EIA and the IgA test was 92 and 96%, respectively; specificity was 100 and 96%, respectively. We conclude that both low-avidity IgG and IgA tests are helpful and reliable for the diagnosis of recent primary infection.

Severe limb girdle muscular dystrophy in Spanish gypsies: further evidence for a founder mutation in the gamma-sarcoglycan gene

Limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive muscular dystrophy with primary gamma-sarcoglycan deficiency, generally associated with a severe clinical course. gamma-sarcoglycan, a 35kDa dystrophin-associated protein, is encoded by a single gene on chromosome 13q12. Six different mutations have been described in that gene, and it has been proved they are the origin of the disease. One of these mutations (C283Y), a G-->A transition in codon 283, was recently and exclusively identified in Gypsy patients from different European countries. We report the study of 11 LGMD2C unrelated Gypsy families (nine Spanish and two Portugese). The muscle biopsies of these patients showed a drastically decreased immunostaining with alpha and gamma-sarcoglycan antibodies. All the patients were homozygous for C283Y missense mutation, and all affected chromosomes (patients and heterozygous relatives) carried the allele 5 (112 bp) of the intragenic microsatellite D13S232. Unexpectedly, this allele is most frequent in the Caucasian population but not in the normal Gypsy population. The clinical severity of all patients demonstrates that the C283Y missense mutation in a homozygous state causes a severe LGMD2C (DMD-like). The elevated number of families ascertained let us assume that LGMD2C is prevalent in the Gypsy population, and that all the families have inherited a founding mutation.