Relevance of silica surface morphology in Ampyra adsorption. Insights from quantum chemical calculations

Theoretical calculations are performed using the Vienna Ab-initio simulation package (VASP) to understand the mechanisms that control the adsorption of Ampyra drug on the different crystallographic planes of β-cristobalite: the hydroxylated (111) and (100) surfaces. The Ampyra-silica interaction is most favored on the (100) surface where the entire ring of the molecule interacts with the surface while on the (111) face, lesser exchange and fewer non-polar atoms are involved. Calculations show that the interactions mainly occur at the interface between the Ampyra and the closest silanol groups, according to the formation of the H-bonding interactions. The results indicate that the H-bonds have an important influence on the adsorption of the Ampyra. In consequence, adsorption on the (111) surface is observed to a lesser extent than on the (100) surface according the smaller hydroxyl density.

DFT calculations are performed to understand the mechanisms that control the adsorption of Ampyra drug on the different crystallographic planes of β-cristobalite: the hydroxylated (111) and (100) surfaces.

A first-principles study of pristine and Al-doped activated carbon interacting with 5-Fluorouracil anticancer drug

The adsorption of the 5-Fluorouracil (5-FU) molecule on the pristine and Al-doped activated carbon (AC) was investigated by using the Vienna Ab-initio Simulation Package. It is found that the 5-FU molecule is only weakly adsorbed on the pristine AC with high adsorption energy and large surface distance. The adsorption of the 5-FU molecule on pristine AC is highly disfavored. In contrast, the molecule shows strong interactions with the Al-doped AC confirmed by the lesser adsorption energy, the charge transfers on the Al-modified zone and the significant changes in the DOS at the Fermi level. The results of our study suggest that the Al dopant increases the adsorption capacity of AC enhancing its interactions with polar atoms of the adsorbate, hence improving its adsorption properties.

Towards high-siderophore-content foods: optimisation of coprogen production in submerged cultures of Penicillium nalgiovense

BACKGROUND

Fungal siderophores are likely to possess atheroprotective effects in humans, and therefore studies are needed to develop siderophore-rich food additives or functional foods to increase the siderophore uptake in people prone to cardiovascular diseases. In this study the siderophore contents of mould-ripened cheeses and meat products were analysed and the coprogen production by Penicillium nalgiovense was characterised.

RESULTS

High concentrations of hexadentate fungal siderophores were detected in penicillia-ripened Camembert- and Roquefort-type cheeses and also in some sausages. In one sausage fermented by P. nalgiovense, the siderophore content was comparable to those found in cheeses. Penicillium nalgiovense produced high concentrations of coprogen in submerged cultures, which were affected predominantly by the available carbon and nitrogen sources under iron starvation. Considerable coprogen yields were still detectable in the presence of iron when the fermentation medium was supplemented with the iron chelator Na₂-EDTA or when P. nalgiovense was co-cultivated with Saccharomyces cerevisiae.

CONCLUSION

These data may be exploitable in the future development of high-siderophore-content foods and/or food additives. Nevertheless, the use of P. nalgiovense fermentation broths for these purposes may be limited by the instability of coprogen in fermentation media and by the β-lactam production by the fungus.

Sterol composition of gonad, muscle and digestive gland of Pecten maximus from Málaga (South Spain)

Sterol composition and content and their seasonal variations over 18 months were investigated in adductor muscle, digestive gland and gonads of Pecten maximus. Sterols were isolated by Silicagel 60 thin layer chromatography and identified by gas chromatography/mass spectrometry. Eleven sterols were identified, with cholesterol, brassicasterol, 24-methylenecholesterol and 22-trans-dehydrocholesterol being the principal components. The same sterols were found in all three tissues independent of season. The relative amounts of each sterol present in each tissue differed. Total sterol levels in gonad and muscle were higher than in digestive gland. Statistically significant differences (P<0.05) were found between the concentrations of each of the sterols isolated from the gonad or muscle and digestive gland. The seasonal variations in the sterol content of the gonad seem be related to the reproductive cycle, while the sterol content of the digestive gland appears to be linked to diet, mainly diatoms or dinoflagellates. The muscle sterol content showed minor changes throughout the year.

Diagnosis of vascular dementia and Alzheimer's disease

Vascular dementia (VaD) and Alzheimer's disease are sometimes difficult to distinguish due to overlaps in symptomatology, pathophysiology and comorbidity. The issue of differential diagnosis is further complicated by the fact that many patients have concomitant Alzheimer's disease and cerebrovascular disease (CVD) ('mixed' dementia). Each pathology may contribute to varying degrees, giving rise to a continuum of patients in whom pure CVD and pure Alzheimer's disease represent the two extremes. Despite the clear overlap between the conditions, and the prevalence of 'mixed' dementia, a number of criteria for Alzheimer's disease and VaD do not make provision for 'mixed' dementia distinct from the coincidence of any two other dementing illnesses. We will discuss the current diagnostic criteria for VaD, with or without coexisting Alzheimer's disease, in an effort to determine how best to diagnose VaD. These include traditional criteria such as the Diagnostic and Statistical Manual of Mental Disorders or the Hachinski Ischemic Scale, and the more recently developed criteria by the California Alzheimer's Disease Diagnostic and Treatment Centers (CAD-DTC) and the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) International Workshop. The CAD-DTC and NINDS-AIREN rely on neuroimaging--ideally, every patient suspected of dementia should have brain imaging, but although this is possible in clinical trials (for which these criteria were designed), it is not always feasible in population-based epidemiological studies and clinical practice in some countries.

A proposal to declare neurocysticercosis an international reportable disease

Neurocysticercosis is an infection of the nervous system caused by Taenia solium. It is the most important human parasitic neurological disease and a common cause of epilepsy in Africa, Asia, and Latin America, representing enormous costs for anticonvulsants, medical resources and lost production. Neurocysticercosis is a human-to-human infection, acquired by the faecal-enteric route from carriers of intestinal T. solium, most often in areas with deficient sanitation. Intestinal tapeworms cause few symptoms, but adult taeniae carried by humans release large numbers of infective eggs and are extremely contagious. Ingestion of poorly cooked pig meat infested with T. solium larvae results in intestinal taeniosis but not neurocysticercosis. With a view to hastening the control of taeniosis and neurocysticercosis we propose that neurocysticercosis be declared an international reportable disease. New cases of neurocysticercosis should be reported by physicians or hospital administrators to their health ministries. An epidemiological intervention could then be launched to interrupt the chain of transmission by: (1) searching for, treating and reporting the sources of contagion, i.e. human carriers of tapeworms; (2) identifying and treating other exposed contacts; (3) providing health education on parasite transmission and improvement of hygiene and sanitary conditions; and (4) enforcing meat inspection policies and limiting the animal reservoir by treatment of pigs. We believe that the first step required to solve the problem of neurocysticercosis is to implement appropriate surveillance mechanisms under the responsibility of ministries of health. Compulsory notification also has the major advantage of providing accurate quantification of the incidence and prevalence of neurocysticercosis at regional level, thus permitting the rational use of resources in eradication campaigns.

Tropical myeloneuropathies revisited

An interesting neurological syndrome, characterized by recurrent optic neuritis, cervical myelopathy from syringomyelia, paraparesis, amenorrhea-galactorrhea, and other endocrine problems, has been described among young black women in the French West Indies. The etiology remains unknown, but possible links with Devic's disease, acute disseminated encephalomyelitis, and neurotoxicity from quinolines in Annona muricata teas have been postulated. The largest epidemic of neuropathy in this century occurred in Cuba in 1991-1994. Clinical features and etiologic studies are reviewed. Its primary cause was nutritional. A similar epidemic was recently described in Tanzania. A number of infectious neuropathies and myopathies are reviewed, including leprosy, tuberculosis, hemorrhagic fevers (Ebola and Marburg filoviruses, Lassa, Argentinean and Bolivian arenaviruses), the human retrovirus human T-cell lymphotropic virus type I, Lyme disease and postimmunization neuropathies. The tropics continue to contribute interesting and important clinical conditions that may illuminate the etiopathiogenesis of other common disorders.

Tropical spastic paraparesis: clinical, immunological, and virological studies in two patients from Martinique

Two patients from Martinique with tropical spastic paraparesis had antibodies to human T-lymphotropic virus type I (HTLV-I) in serum and spinal fluid but no antibodies to other retroviruses tested. They presented with spastic weakness of both lower extremities, hyperreflexia with upgoing toes, sphincteric dysfunction, and normal sensation. By means of agarose isoelectric focusing and selective immunoblotting we demonstrated an increased intrathecal synthesis of IgG antibodies to HTLV-I in the spinal fluid. Unique oligoclonal bands of IgG antibodies to HTLV-I were present in the cerebrospinal fluid. Using a battery of monoclonal antibodies we also found in these patients an increased number of circulating T cells that expressed activation markers. We conclude that the HTLV-I retrovirus associated with tropical spastic paraparesis has both lymphocytotropic and neurotropic properties.

HLA antigens in patients with schizophrenic syndromes

HLA antigens were studied in 50 patients, 40 males, 10 females and two brothers of patients, all suffering from schizophrenic syndromes. The average duration of illness for the whole group was 18 +/- 1.5 years. The frequency of A10 antigen was increased in the schizophrenic patients as compared with 449 healthy individuals. None of the findings concerning HLA and schizophrenia reported in the literature could be verified in the present study. Two ill brothers comprised in the study proved to have the same HLA phenotype as their respective ill sibling. So far there is no conclusive evidence for association between any HLA antigen and 'schizophrenia'. Further investigations should be concerned with families and not with single patients.

Parainfluenza virus type 3: isolation from CSF of a patient with Guillain-Barré syndrome

We report the isolation of parainfluenza virus type 3 from the CSF of a 19-year-old man with Guillain-Barré syndrome. Although parainfluenza viruses are usually associated with respiratory tract illnesses, some strains show a neurotropism not previously appreciated. Thus, parainfluenza viruses may be responsible for a portion of cases of Guillain-Barré syndrome.

Hereditary multiple exostoses. A rare cause of spinal cord compression

A case of hereditary multiple exostoses (HME) with compression of the cervical cord, the cervical plexus, and the ulnar nerve is reported. Complete recovery following surgery was obtianed. Review of the literature revealed 21 previous cases of HME with cord compression. The cervical and thoracic areas are predominantly affected and the symptoms usually evolve slowly. Recovery after laminectomy is to be expected in the majority of the cases.

Neurological manifestations of hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease): report of 2 cases and review of the literature

Two cases of hereditary hemorrhagic telangiectasia (HHT) with neurological involvement are presented. One patient had multiple vascular malformations including telangiectasias of the brain, medulla, and spinal cord and a berry aneurysm of the internal carotid artery; she also had a large cerebellar abscess, presumably reflecting the presence of a pulmonary arteriovenous fistula. The second patient had an idiopathic subarachnoid hemorrhage. In more than 200 reported patients with HHT involving the nervous system, 61% had lesions seondary to a pulmonary arteriovenous fistula (cerebral hypoxemia, paradoxical and septic emboli, and brain abscess). The findings emphasize the need for early surgical correction of such fistulas. In 36% of the patients with neurological involvement and HHT, vascular malformations of the brain and spinal cord were documented, and in 3%, portal-systemic encephalopathy was noted. Multiple lesions were frequent. HHT should be considered a generalized vascular dysplasia (universal or systemic angiomatosis), and not simply a benign mucocutaneous disease.

Cerebral malaria. A disseminated vasculomyelinopathy

Neuropathologic examination of 19 fatal cases of cerebral malaria and a review of the literature showed that the epidemiologic, clinical, and pathologic features of this entity suggest consideration of cerebral malaria as a form of disseminated vasculomyelinopathy, a hyperegic reaction of the CNS to the antigenic challenge of Plasmodium falciparum infection. Experimental evidence also substantiates this view The initial event seems to be vasculopathy, with alteration of the endothelial permeability, followed by brain edema, perivascular infiltrates and ring hemorrhages, perivascular demyelination, and gliosis (malarial granuloma) in the late stages. This chain of events could be interrupted early in its course by corticosteroids. Parenteral dexamethasone should then be seriously considered at the first signs of involvement of the CNS during P falciparum malaria along with the standard forms of antimalarial therapy.

Recurrent disseminated vasculomyelinopathy

The monosymptomatic (recurrent infantile hemiplegia) and the polysymptomatic forms of disseminated vasculomyelinopathy that follow various infections and antigenic challenge to the nervous system were seen in two cases. These cases emphasize the importance of vasculopathy as the initial and obligatory component of the postinfectious and postimmunization neurologic syndromes as well as the clinical and pathological variability of the secondary effects on the nervous system. Recurrent infantile hemiplegia occurred in the first patient. In the second patient, after two episodes of postinfectious myelinoclastic encephalopathy, concurrent acute hemorrhagic leukoencephalopathy and an acute Guillain-Barré syndrome following swine flu vaccination developed.

Neuroparalytic accidents of antirabies vaccination with suckling mouse brain vaccine. Clinical and pathologic study of 21 cases

Twenty-one cases of neuroparalytic accidents of rabies vaccination (with suckling mouse brain vaccine), 11 of them fatal, were observed, occurring predominantly in men; the mean age of the patients was 29 years. On the average, 13 doses of the vaccine were used. Only three patients received less than seven doses. The mean latent period was 14 days (range, 4 to 24 days). In 16 patients (76%), a Guillain-Barré syndrome occurred that was moderate in three, severe in seven, and fatal in six. Pathologically, this was shown to be a typical polyradiculoneuritis. Five patients had fatal involvement of the central nervous system. Three had an acute disseminated perivenous leukoencephalopathy, with concurrent rabies encephalitis in one case. One patient had a perivenous myeloradiculopathy and one a chronic encephalomyelopathy of six years' duration with demyelinating plaques in the periventricular white matter, cerebellum, and spinal cord. Since the reduction of postexposure rabies vaccination to seven doses, no new cases have been observed in Colombia.

Comparative clinical evaluation of lofepramine and imipramine. Pharmacological aspects

A multicentre comparative clinical evaluation of lofepramine, an imipramine analogue, and imipramine has been made with double-blind technique and fixed dosage (lofepramine 70 mg t.i.d., imipramine 50 mg t.i.d.). Plasma was drawn after 3 weeks for determination of noradrenaline-uptake inhibitory capacity of the parent compound and/or its active metabolites. Plasma concentrations of lofepramine and desmethylimipramine (DMI) were determined in the same samples. The concentrations of lofepramine in the whole material were low (5-27 ng/ml) except for one patient who had a level of 53 ng/ml. In both groups of patients there was an almost 40-fold range in the plasma levels of DMI or apparent DMI. The patients were rated for severity of depression before treatment, then once weekly for 3 weeks and finally during the fifth week. For further information concerning the psychiatric aspects, see d'Elia et al. in this issue (1977). A significant correlation was found between the concentrations of DMI and the noradrenaline-uptake inhibitory capacity in the plasma samples. No correlations were found between uptake inhibitory capacity of plasma samples and the amelioration scores.

Comparative clinical evaluation of lofepramine and imipramine. Psychiatric aspects

Lofepramine, an imipramine analogue, was compared with imipramine in a multicentre, double-blind clinical trial. The 62 patients (31 in each of two treatment groups) had a depressive syndrome that normally would have been treated with a tricyclic antidepressant. These patients had not received any adequate treatment for this present depressive episode. After a wash-out period and once a week during treatment (up to 5 weeks), routine laboratory tests and electrocardiograms was done. The dosage was 50 mg t.i.d. for imipramine and 70 mg t.i.d. for lofepramine. Depression ratings with the Cronholm-Ottosson depression rating scale were performed before treatment and once weekly for 3 weeks and then in the 5th week. The last four ratings were combined with rating of side-effects. In the 5th week of treatment 15 out of 31 in the lofepramine group and 18 out of 31 in the imipramine group had recovered. This difference was not significant, nor did the median values of individual symptoms differ between the groups. The side-effects were moderate and the two groups only differed significantly in the items "dry mouth" and accommodation disturbances in favour of lofepramine. The drug compliance was checked by plasma levels of desmethylimipramine in the imipramine group, parent compound, and "apparent" desmethylimipramine in the lofepramine group. The relationship between plasma drug levels, the effect on noradrenaline uptake in vitro and amelioration discussed in Siwers et al. (1977) in this issue. The clinical outcome in the two groups did not differ significantly; interpretation of this result is discussed in relation to the reliability and selection of patients.