Nitroglycerin-induced activation of monoaminergic transmission in the rat

When administered to migraine patients, nitroglycerin induces a spontaneous-like migraine attack, with a latency of several hours. Nitroglycerin acts directly and/or indirectly on the central nervous system, through the release of nitric oxide (NO). Systemic administration of the drug to the rat causes neuronal activation in selected subcortical areas, particularly in monoaminergic nuclei of the brainstem. In this study, we sought to investigate whether this activation correlates with changes in monoaminergic neurotransmission. For this purpose, we evaluated the tissue levels of catecholamines and serotonin in the hypothalamus, mesencephalon, pons and medulla of rats treated with systemic nitroglycerin or vehicle, at different time points (1, 2 and 4 h). We also evaluated the peripheral sympathetic response to the drug by measuring the concentrations of plasma catecholamines. Nitroglycerin caused an early (1 h) increase in cerebral (pons) and plasma levels of norepinephrine, followed by a delayed (4 h) decrease in medullary and pontine levels of serotonin. The initial noradrenergic activation may reflect the autonomic response to the rapid cardiovascular effects of the drug, while the delayed response may result from the interaction of nitroglycerin-released NO and 5-HT in central areas devoted to the modulation of nociception. These data might therefore help to clarify the mechanisms underlying the delayed migraine attack observed in migraine sufferers after systemic administration of nitroglycerin.

Informing the public about advances in cancer therapy

The word cancer continues to be associated with fear and pessimism among the general public, but they also hear of "new breakthroughs" in the field of oncology. This paper considers whether or not such research advances in cancer are occurring and, if so, is this information being accurately transmitted both within and outside the medical profession. If information is to be given to the public, what preparatory work needs to be achieved in order that this is done effectively.

The genetic abnormality in the beta cell determines the response to an oral glucose load

AIMS/HYPOTHESIS

We assessed how the role of genes genetic causation in causing maturity-onset diabetes of the young (MODY) alters the response to an oral glucose tolerance test (OGTT).

METHODS

We studied OGTT in 362 MODY subjects, from seven European centres; 245 had glucokinase gene mutations and 117 had Hepatocyte Nuclear Factor -1 alpha ( HNF-1alpha) gene mutations.

RESULTS

BMI and age were similar in the genetically defined groups. Fasting plasma glucose (FPG) was less than 5.5 mmol/l in 2 % glucokinase subjects and 46 % HNF-1 alpha subjects ( p < 0.0001). Glucokinase subjects had a higher FPG than HNF-1 alpha subjects ([means +/- SD] 6.8 +/- 0.8 vs 6.0 +/- 1.9 mmol/l, p < 0.0001), a lower 2-h value (8.9 +/- 2.3 vs 11.2 +/- 5.2 mmol/l, p < 0.0001) and a lower OGTT increment (2-h - fasting) (2.1 +/- 2.3 vs 5.2 +/- 3.9 mmol/l, p < 0.0001). The relative proportions classified as diabetic depended on whether fasting (38 % vs 22 %, glucokinase vs HNF-1 alpha) or 2-h values (19 % vs 44 %) were used. Fasting and 2-h glucose values were not correlated in the glucokinase subjects ( r = -0.047, p = 0.65) but were strongly correlated in HNF-1 alpha subjects ( r = 0.8, p < 0.001). Insulin concentrations were higher in the glucokinase subjects throughout the OGTT.

CONCLUSION/INTERPRETATION

The genetic cause of the beta-cell defect results in clear differences in both the fasting glucose and the response to an oral glucose load and this can help diagnostic genetic testing in MODY. OGTT results reflect not only the degree of hyperglycaemia but also the underlying cause.

Uric acid concentration in subjects at risk of type 2 diabetes mellitus: relationship to components of the metabolic syndrome

High uric acid concentration is a common finding in subjects with risk factors for cardiovascular disease (CVD), including some characteristics of the metabolic syndrome. However, its exact role in this setting and in the progression to type 2 diabetes mellitus (DM) is not well understood and could be affected by confounding factors such as hypertriglyceridemia. Our study aimed to establish the relationship between uric acid (avoiding the interference of high triglyceride levels), insulin sensitivity, and components of the metabolic syndrome in a group of subjects at high risk of developing DM. Among 201 subjects included in the study, 111 (55.2%) showed an abnormal oral glucose tolerance and uric acid levels higher than those measured in subjects with normal glucose tolerance. Body mass index (BMI), triglycerides, diastolic blood pressure (DBP), and 2-hour glycemia in the oral glucose tolerance test (OGTT) contributed independently to uric acid concentration (R2 =.59). However, uric acid did not affect either insulin sensitivity or glucose tolerance. The recovery tests revealed that a triglyceride concentration > or = 3 mmol/L interfered with the measurement of uric acid level when a colorimetric method was used, but not when a dry-chemistry method was used. In conclusion, uric acid concentration is higher in subjects at high risk of DM with abnormal glucose tolerance and is independently determined by various components of the metabolic syndrome.

Attitudes towards intramural continuing medical education: a european perspective

Continuing medical education (CME) is now one of the key areas of development in medical education. This paper describes the development of an intramural continuing medical education programme de novo in a newly opened cancer institute in Italy, which provided a unique opportunity to study attitudes towards the concepts and goals of continuing medical education as most of the individuals involved in this programme were exposed to continuing medical education for the first time. The continuing medical education programme was overseen by a CME committee for 1 year. Three 1-hour sessions were delivered each week and one credit point was awarded for each session. The sessions included grand rounds, clinical-based teaching and a 3-weekly rotating schedule of pathology, radiology and research. Participants were all the medical doctors attending the European Institute of Oncology. Attendance at greater than 50% of the total sessions available yearly qualified the individual for certification by the CME committee of the Institute. A questionnaire was circulated to all medical doctors at the Institute at the end of the academic year to assess attitudes to CME in general. Forty-six out of 84 questionnaires were returned. The majority of those involved in this CME intramural programme undertook self-directed CME activities and at least 50% had not previously attended either grand rounds or research seminars. Most felt that CME should not be mandatory but that its activities should be monitored. The greatest difficulty with CME was in its timing.

[Cerebral hematoma caused by mucormycosis]

INTRODUCTION

Invasion of the central nervous system by mucormycosis is rare. It is mainly seen in diabetic ketoacidosis, immunosensitive or severely debilitated patients and in cases of hematological neoplasias. We describe a case of cerebral hemorrhage with documented evidence of invasion of the cerebral vessels by mucormycosis, in a patient with a gastric adenocarcinoma.

CLINICAL CASE

A 38 year old woman complained of the sudden onset of headache and disorder of vision which progressed rapidly to coma. Computerized tomography showed the presence of a parieto occipital hematoma. The patient died six hours later. She had had an operation for gastric carcinoma eight months previously. Anatomopathological study of the brain showed invasion of the arterial wall by mucormycosis.

CONCLUSION

Solid tumors may lead to cerebral hemorrhage caused by mucormycosis.

Alexithymic features in stroke: effects of laterality and gender

OBJECTIVE

Stroke patients suffer from a high rate of behavioral disorders, and the laterality of the lesion may affect the expression of emotional disturbances. This study tested the hypothesis that stroke patients with a lesion in the right hemisphere are at high risk of developing alexithymic features.

METHODS

Forty-eight patients were interviewed with the Structured Clinical Interview for DSM-IV (patient edition), the Mini-Mental State Examination, the State-Trait Anxiety Inventory (state form), the Beck Depression Inventory, and the Toronto Alexithymia Scale (20-item version). Alexithymic differences between stroke patients with a lesion in the right hemisphere and those with a lesion in the left hemisphere were computed by analysis of covariance, using scores on the Mini-Mental State Examination, Beck Depression Inventory (psychic subscore), and State-Trait Anxiety Inventory as covariates and the score on the Toronto Alexithymia Scale as the dependent variable. A multivariate analysis of covariance and a series of follow-up analyses of covariance with the same covariates were used to discriminate differences in subscores on the Toronto Alexithymia Scale. An exploratory analysis of covariance was also performed to determine the effect of gender on alexithymic features in both groups of stroke patients.

RESULTS

The 21 stroke patients with a lesion in the right hemisphere were more alexithymic than the 27 patients with a lesion in the left hemisphere. This evidence was strengthened by the categorical analysis: 48% of the patients with a right-hemisphere lesion had alexithymia, compared with 22% of patients with a left-hemisphere lesion. Univariate analyses of covariance showed significant differences between the two groups in difficulty identifying feelings and difficulty describing feelings, but not in externally oriented thinking. The last exploratory analysis of covariance suggested that gender may influence alexithymic features.

CONCLUSIONS

This study provides direct evidence that alexithymia, and more specifically difficulty identifying feelings and difficulty describing feelings, is more common in stroke patients with a right-hemisphere lesion than in those with a left-hemisphere lesion. It also provides preliminary evidence that gender may affect alexithymic expression.

The specific-word frequency effect: implications for the representation of homophones in speech production

In a series of experiments, the authors investigated whether naming latencies for homophones (e.g., /nlambdan/) are a function of specific-word frequency (i.e., the frequency of nun) or a function of cumulative-homophone frequency (i.e., the sum of the frequencies of nun and none). Specific-word but not cumulative-homophone frequency affected picture-naming latencies. This result was obtained in 2 languages (English and Chinese). An analogous finding was obtained in a translation task, where bilingual speakers produced the English names of visually presented Spanish words. Control experiments ruled out that these results are an artifact of orthographic or articulatory factors, or of visual recognition. The results argue against the hypothesis that homophones share a common word-form representation, and support instead a model in which homophones have fully independent representations.

[Two case reports of cerebral autosomal dominant arteriophaty with subcortical infarctions and leukoencephalopathy (CADASIL)]

Cerebral autosomal dominant arteriopathy with subcortical infarctions and leukoencephalopathy (CADASIL) was first reported in European families and since 1993 it has been observed in America, Africa and Asia, suggesting that today the disease probably still remains largely underdiagnosed. CADASIL appears to be essentially a disorder of the arteries linked to single missense mutations in the Notch3 gene locus on chromosome 19; the aberrant dimerisation of Notch3, due to abnormal disulphide bridging with another Notch3 molecule or with another protein, may be involved in the pathogenesis of the disorder. It is characterized by recurrent stroke episodes and focal neurologic deficits progressing to pseudobulbar palsy and dementia, caused by multiple lacunar infarctions with ischemic and diffuse white matter abnormalities on neuroimaging. Migraine with aura, epileptic seizures and affective disorders are frequent additional symptoms of CADASIL. It is usually observed in the 3rd decade, but some individuals remain asymptomatic close to the age of 60. MRI displays a marked leukoencephalopathy in affected individuals as early as in the age of 20. The authors emphasize the role of a direct DNA test for gene mutation to make a differential diagnosis between CADASIL and other forms of vascular leukoencephalopathy as Alzheimer's dementia, multiple sclerosis and Binswanger's subcortical arteriopathic encephalopathy where CADASIL's arteriopathy is characterized by major alterations of vascular smooth muscle cells and the presence of specific granular osmiophilic deposits.

European School of Oncology: 20 years of cancer education and a contribution to European Guidelines of Oncology

Since its creation in 1982, the European School of Oncology (ESO) not only looks back on two successful decades of cancer education and active promotion of knowledge and provision of oncology training in almost all parts of the world, but also the establishment of the State-of-the-Art (START) European oncology guidelines, a free, Internet-based, and readily accessible program of evidence-based medicine. In addition, ESO has been at the forefront of various activities which have led to the evolution of a common Continuing Medical Education system in Europe. A special framework to support the training of health care providers in underdeveloped countries was also launched by ESO. On the occasion of its 20th anniversary, ESO reflects on the past, defines the status quo and presents its future prospects.

Alpha-interferon improves liver fibrosis in chronic hepatitis C: clinical significance of the serum N-terminal propeptide of procollagen type III

Our objective was to estimate the effect of interferon (IFN) on the evolution of fibrosis in chronic hepatitis C and the significance of the N-terminal propeptide of procollagen type III (PIIIP) as a marker of fibrogenesis. One hundred seventeen patients, 72 male (61%) and 45 female (39%), with a mean age of 40.7+/-11.9 years were treated with a2b-IFN, 3 to 5 MU, for 12 months: sustained responders (SR = 44), relapsers (RR = 35), and nonresponders (NR = 38). Liver biopsies were performed before treatment and 1 year after cessation of IFN for evaluation of the histological activity index (HAI). Serum PIIIP was obtained at the time of liver biopsy, at the beginning, during, and end of therapy and during the follow-up. The normal value in 29 healthy individuals was 0.37+/-0.18 U/L. Staging was reduced in 58% of SR, 12.5% of RR, and 11.5% of NR. There was a correlation between PIIIP and the HAI before (n = 71, r(s) = 0.41, P < 0.0004) and after IFN (n = 71, r(s) = 0.58, P < 0.0001). The SR had a better improvement in grading (90.3%; P < 0.05) and staging (58%; P < 0.001). The correlation of the HAI parameters with the variation of PIIIP showed significance only for fibrosis (r(s) = 0.36, P < 0.002) and portal inflammation (r(s) = 0.35, P < 0.01). PIIIP normalized only in patients whose fibrosis improved (P < 0.01). At the end of therapy, PIIIP had a predictive value in the distinction of SR from RR (PPV, 64; PNV, 55.6). During the follow-up, PIIIP remained lower in SR compared with RR and NR (P < 0.002). The response to a-IFN improved liver inflammation and fibrosis. Serum PIIIP is a useful noninvasive method to evaluate serially fibrogenesis in chronic hepatitis C treated with IFN.

Set size and repetition in the picture--word interference paradigm: implications for models of naming

Caramazza and Costa (Cognition 75 (2000) B51) reported results which demonstrate that a semantically related word distractor interferes in picture naming even when it is not in the response set and there is no possibility for mediated interference. They interpreted the results to be problematic for the model of lexical access proposed by Levelt, Roelofs, and Meyer (Behavioral and Brain Sciences 22 (1999) 1). Roelofs (Cognition 80 (2001, this issue 283--90)) argues that those results are not inconsistent with Levelt et al.'s model when certain new assumptions about the mechanism of lexical selection are considered. Here we show that even with these assumptions the model still makes the wrong predictions. We report new results which demonstrate that the semantic interference and facilitation effects that are obtained respectively in the basic-level and category-level naming variants of the picture-word interference paradigm are not the result of response set size and response repetitions.

Paracrine roles of NAD+ and cyclic ADP-ribose in increasing intracellular calcium and enhancing cell proliferation of 3T3 fibroblasts

CD38 is a bifunctional ectoenzyme synthesizing from NAD(+) (ADP-ribosyl cyclase) and degrading (hydrolase) cyclic ADP-ribose (cADPR), a powerful universal calcium mobilizer from intracellular stores. Recently, hexameric connexin 43 (Cx43) hemichannels have been shown to release cytosolic NAD(+) from isolated murine fibroblasts (Bruzzone, S., Guida, L., Zocchi, E., Franco, L. and De Flora, A. (2001) FASEB J. 15, 10-12), making this dinucleotide available to the ectocellular active site of CD38. Here we investigated transwell co-cultures of CD38(+) (transfected) and CD38(-) 3T3 cells in order to establish the role of extracellular NAD(+) and cADPR on [Ca(2+)](i) levels and on proliferation of the CD38(-) target cells. CD38(+), but not CD38(-), feeder cells induced a [Ca(2+)](i) increase in the CD38(-) target cells which was comparable to that observed with extracellular cADPR alone and inhibitable by NAD(+)-glycohydrolase or by the cADPR antagonist 8-NH(2)-cADPR. Addition of recombinant ADP-ribosyl cyclase to the medium of CD38(-) feeders induced sustained [Ca(2+)](i) increases in CD38(-) target cells. Co-culture on CD38(+) feeders enhanced the proliferation of CD38(-) target cells over control values and significantly shortened the S phase of cell cycle. These results demonstrate a paracrine process based on Cx43-mediated release of NAD(+), its CD38-catalyzed conversion to extracellular cADPR, and influx of this nucleotide into responsive cells to increase [Ca(2+)](i) and stimulate cell proliferation.

[Autoimmune cholangiopathy]

We report two patients with mixed characteristics of primary biliary cirrhosis and autoimmune hepatitis. They are two female patients in their fifties (54 and 58 years-old) one of them with autoimmune phenomenon, rheumatoid arthritis and Sjögren syndrome. Both of them showed laboratory values of cholestasis and the liver biopsy revealed liver cirrhosis with significant lesions of the bile ducts. They were treated with prednisolone with a rapid improvement and normalisation of their blood tests. They belong to a group called as overlap syndrome or autoimmune cholangitis with mixed characteristics, clinical, biochemical, immunological, and histopathologic overlapping between primary biliary cirrhosis and autoimmune hepatitis type I.

An autoregulatory feedback loop directs the localized expression of the Drosophila CPEB protein Orb in the developing oocyte

The RRM-type RNA binding protein Orb plays a central role in the establishment of polarity in the Drosophila egg and embryo. In addition to its role in the formation and initial differentiation of the egg chamber, orb is required later in oogenesis for the determination of the dorsoventral (DV) and anteroposterior (AP) axes. In DV axis formation, Orb protein is required to localize and translate gurken mRNA at the dorsoanterior part of the oocyte. In AP axis formation, Orb is required for the translation of oskar mRNA. In each case, Orb protein is already localized at the appropriate sites within the oocyte before the arrival of the mRNAs encoding axis determinants. We present evidence that an autoregulatory mechanism is responsible for directing the on site accumulation of Orb protein in the Drosophila oocyte. This orb autoregulatory activity ensures the accumulation of high levels of Orb protein at sites in the oocyte that contain localized orb message.