Synthesis and bioactivity of nobilamide B.

An alternative and facile solution/solid-phase approach is reported for the total synthesis of neuroactive peptide, nobilamide B. Z-Dhb was formed in solution via EDC/CuCl induced elimination. The solid-phase synthesis employed HBTU/Oxyma Pure™ coupling using Barlos resin. Synthetic nobilamide B was also found to be neuroactive in primary cultures of dorsal root ganglion (DRG) neurons.

An experimental model of peripheral neuropathy induced in rats by Karwinskia humboldtiana (buckthorn) fruit.

Intoxication by Karwinskia humboldtiana (buckthorn) fruit presents a neurological picture similar to that of Guillain-Barré syndrome. In this report, we describe an experimental animal model of peripheral neuropathy induced by buckthorn fruit. Four groups of Wistar rats received one oral dose of 1.5 g/kg followed by oral doses of 0.5 g/kg at days 3, 7, 10, and 14 of dried and ground buckthorn fruit in aqueous suspension. Rats were sacrificed at 24, 48, 58, and 112 days after initial dose. Treated animals developed progressive paralysis through 58 days, then completely recovered by 112 days. Sciatic nerves showed segmental demyelination and cellular infiltrates until 58 days after exposure and then remyelinating changes at 112 days. This experimental model for peripheral neuropathy is reproducible and easy to handle. Its manipulation is relatively innocuous and allows us to study reversible peripheral nerve damage. This model can be developed in other animal species and may be useful to test new therapies for peripheral neuropathy.

Preparation of Entamoeba histolytica antigens without enzymatic inhibitors.

The goal of this work is to report a novel assay that preserves antigenicity of extracts with high protease content without using enzymatic inhibitors. A great reduction of proteolytic activity in the insoluble chloroform/methanol and heated amoebic fraction (IC:MC) was obtained by this method, even in the presence of sodium dodecyl sulphate and 2-mercaptoethanol. The substrates azo-casein and the hide powder azure were used to determine the reduction of proteolytic activity of IC:MC compared with the activity of crude extract and crude extract with iodoacetamide. The IC:MC SDS-PAGE pattern shows a higher quantity of bands than extract with the inhibitor iodoacetamide or than crude extract. In addition, anti-Entamoeba histolytica antibodies from amoebic liver abscess patients recognized a richer antigenic Western blot pattern in the IC:MC fraction than in crude extract alone or with inhibitor. The described method has proved to be suitable to preserve amoebic antigens for its use in diagnostic tests and it can be used for immunological response studies against E. histolytica antigens. Furthermore we propose that this method to obtain the IC:MC fraction can be applied for the study of other microorganisms or cells with high enzymatic content.

Evaluation of magnetic behaviour and in vitro biocompatibility of ferritic PM2000 alloy.

PM2000 is a ferritic alloy obtained by powder metallurgy and is being investigated for potential applications as a biomaterial. This work aimed to assess the biological compatibility and to determine the influence of the processing route and further recrystallisation treatment on the magnetic behaviour. The magnetic behaviour has been analysed as a function of the hysteresis loop obtained by using an inductive method. The biocompatibility has been tested using human osteoblast-like cells seeded onto discs of PM2000. The ability of cells, on its surface, to attach, grow, and produce alkaline phosphatase (ALP) was determined. It is shown that PM2000 is a soft magnetic material irrespective of its material condition, its remanent magnetisation being very low (up to about 3% for the recrystallised swaged material). Fields close to 200 Oe are required to saturate the material. The saturation magnetisation is about 135 emu g(-1). In vitro tests indicate that cells are able to attach and grow onto its surface, and produce ALP, a specific marker of cells with bone-forming activity. In this respect, PM2000 holds promise as a suitable substrate for bone integration. These properties could make PM2000 a useful candidate for the preparation of medical devices where biocompatible and soft magnetic materials are sought. Applications for dental magnetic attachments could be envisaged.

[Lack of iron in adolescents aged 10 to 14]. / Carencia de hierro en adolescentes (10-14 años).

AIMS: To study the prevalence of depletion of organic iron stores, ferropenia and ferropenic anemia in the adolescent population in a health care district in northern Spain. Design. Cross-sectional, with systematic sampling. SETTING: Primary health care service in a rural setting. PARTICIPANTS: Sample of 204 healthy adolescents aged 10.0 to 14.0 years; 93 males, 111 females. MAIN MEASURES: Familial and personal antecedents, physical activity, date of menarche, weight, height and body mass index, hemoglobin (Hb), mean corpuscular volume (MCV), transferrin saturation index (TSI) and serum ferritin (SF) were recorded for 1 out of every 4 adolescents who visited the health center for a regular check-up. Positive C-reactive protein or erythrocyte sedimentation rate were criteria for exclusion. Iron stores were considered to be depleted when SF was < 12 ng/dL, ferropenia was said to exist when, in addition, TSI was < 14% or MCV was < 75 fL, and ferropenic anemia was said to exist when, in addition, Hb was < 12 g/dL. RESULTS: Some stage of iron deficiency was found in 8.6% of the males and 12.6% of the females. Iron stores were depleted in 2.2% and 6.3%, respectively; ferropenia was found in 3.2% and 3.6%, respectively; and anemia was found in 3.2% and 2.7%, respectively. There were no significant differences between the sexes. CONCLUSIONS: In adolescents aged 10 to 14 years in our health care setting, iron deficiency was relatively common. Health care programs for children and adolescents should aim specifically to prevent, detect and control iron deficiency.

[Meningiomas of the cavernous sinus: the surgical resectability and complications]. / Meningiomas do seio cavernoso: correlação entre a extensão de ressecção cirúrgica e lesões neurovasculares em 16 pacientes.

The optimal management for patients with cavernous sinus meningiomas is to evacuate tumor without causing mortality or morbidity. The records of 16 patients, including 11 women and 5 men ranging in age from 31 to 63 years, underwent surgical treatment for this condition were reviewed. Completeness of tumor resection, cranial nerve morbidity, complications, mortality, the internal carotid artery encasement and outcome were studied. Total removal was achieved in six patients. Of ten patients who underwent subtotal resection there was one death and four were sent to radiotherapy. Morbidity was 24% for cranial nerves controlling extraocular motor function; trigeminal nerve function did not improve after surgical treatment. Symptomatic recurrence occurred in two patients who underwent subtotal tumor resection and in one who underwent complete tumor resection. The average follow-up period was of 26 months. According to our findings, we conclude: 1) the resectability of meningiomas of cavernous sinus depends on the degree of internal carotid artery involvement; 2) total resection of meningiomas confined in cavernous sinus is rare; 3) morbidity of the cranial nerves is significant; 4) subtotal resection is an effective mean to obtain control of the disease.

[Subfrontal approach in sellar and suprasellar lesions]. / Acesso sub-frontal a lesões selares e para-selares.

A variety of mass lesions are placed in and around of the sella turcica. Although their common location these lesions have distinguishing features and different approaches can be selected. There are conventional transcranial and sophisticated skull base approaches. We report our experience with a subfrontal route to the sellar region. Between February 1997 and March 1998, 19 tumors placed around the sella have been treated surgically by this method. Eleven of them were pituitary tumors, 3 were craniopharyngeomas, 2 were meningiomas, and 1 was germinoma. Total removal was achieved in 17 cases. There was not operative mortality. Postoperative complications included twelve cases of unilateral anosmia and four cases of transitory diabetes insipidus. Progressive stroke occurred in one patient. These results stress the importance of the subfrontal approach to reach such lesions in sellar region.

Posterior fossa craniotomy. Technical report.

The use of craniotomy to approach supratentorial lesions is quite well established in the literature. The use of craniotomy for posterior fossa approaches, however, is not well described. The aim of this article is to describe the technical aspects of this approach and to delineate the important landmarks. In our cases, posterior fossa craniotomies have been utilized for treat different pathologies. Additionally, the technique has not added any additional risk, and the cosmetic results have been excellent.