Differentiation induced by Achyrocline satureioides (Lam) infusion in PC12 cells.

Epidemiological studies have shown that flavonoid-rich plants induce beneficial health effects that are likely beyond their potent antioxidant capacity. Thus, the mechanisms by which Achyrocline satureioides (AS), a popular South American medicinal plant, protects cells and neurons in culture, are still unclear. In this sense, a recently described trophic capacity for flavonoids, similar to that evoked by growth factors, could be one of the mechanisms involved in AS cellular protection. Since this trophic activity causes differentiation of PC12 cells, the cell differentiation capacity of AS and some of its flavonoids were evaluated. PC12 cells were treated with AS infusion (10 or 20 microg/mL of total polyphenols), quercetin (Q) (12.5 or 25 microm), luteolin (L) (25 microm), Q + L (12.5 microm each one) or nerve growth factor (NGF) for 3 days. Four morphological parameters (percentage of cells with neurites longer than one cell body diameter, percentage of cells with neurites, average number of neurites per cell and percentage of fusiform cells) were explored. The AS infusion showed differentiation capacity on all parameters with similar potency when compared with NGF. Besides, AS was more potent than some of its constituent flavonoids: Q, L or their combination.

Regulation of axonal microtubules: effect of sympathetic hyperactivity elicited by reserpine.

The density of microtubules in sympathetic postganglionic fibres of the cat was studied with the electron-microscope before and after administration of reserpine. The microtubule density was 56 microtubules per square micron under basal conditions. Six hours after reserpine administration, the density rose by 46%. This change was still present 55 h later. At least 31% of the total microtubular protein in the axoplasm of sympathetic fibres of the unrestrained cat was estimated to be in the soluble form. The increase in microtubule density was prevented by a section of the preganglionic fibres. Microtubules of the unmyelinated fibres of the cutaneous sural nerve were unaffected by reserpine treatment. Since reserpine is known to produce hyperactivity of sympathetic nerves, it is concluded that this hyperactivity is instrumental in the increase of the number of axonal microtubules. It is proposed that the electrical activity of nerves regulates axonal microtubules in the living animal.

Neuroprotection by flavonoids.

The high morbidity, high socioeconomic costs and lack of specific treatments are key factors that define the relevance of brain pathology for human health and the importance of research on neuronal protective agents. Epidemiological studies have shown beneficial effects of flavonoids on arteriosclerosis-related pathology in general and neurodegeneration in particular. Flavonoids can protect the brain by their ability to modulate intracellular signals promoting cellular survival. Quercetin and structurally related flavonoids (myricetin, fisetin, luteolin) showed a marked cytoprotective capacity in in vitro experimental conditions in models of predominantly apoptotic death such as that induced by medium concentrations (200 M) of H2O2 added to PC12 cells in culture. Nevertheless, quercetin did not protect substantia nigra neurons in vivo from an oxidative insult (6-hydroxydopamine), probably due to difficulties in crossing the blood-brain barrier. On the other hand, treatment of permanent focal ischemia with a lecithin/quercetin preparation decreased lesion volume, showing that preparations that help to cross the blood-brain barrier may be critical for the expression of the effects of flavonoids on the brain. The hypothesis is advanced that a group of quercetin-related flavonoids could become lead molecules for the development of neuroprotective compounds with multitarget anti-ischemic effects.

Screening of antioxidant activity of three Indian medicinal plants, traditionally used for the management of neurodegenerative diseases.

A number of Indian medicinal plants have been used for thousands of years in the traditional system of medicine (Ayurveda). Amongst these are plants used for the management of neurodegenerative diseases such as Parkinson's, Alzheimer's, loss of memory, degeneration of nerves and other neuronal disorders by the Ayurvedic practitioners. Though the etiology of neurodegenerative diseases remains enigmatic, there is evidence, which indicates that defective energy metabolism, excitotoxicity and oxidative damage may be crucial factors (Ann. Neurol. 38 (3) (1995) 357). The part of the Ayurvedic system that provides an approach to prevention and treatment of degenerative diseases is known as Rasayana, and plants used for this purpose are classed as rejuvenators. This group of plants generally possesses strong antioxidant activity (Pharmacol. Biochem. Behav. 43 (1992) 1175), but only a few have been investigated in detail. In the present study, three such rasayana plants were tested for the first time for their toxicity and free radical scavenging activity both in vitro and ex vivo. All the three plant infusions (up to 1 mg/ml) showed no toxic effects on the viability of PC12 cell line as judged by MTT-test. Both ethanolic extracts and water infusions of the plants were tested for their antioxidant activity in the 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS*(+)) radical cation decolorization assay; inhibition of lipid peroxidation by plant infusions was carried out using spontaneous lipid peroxidation of rat brain homogenate, and IC50 values were determined. The results from the ABTS assay showed that the ethanolic extract of Sida cordifolia was found to be most potent (IC50 16.07 microg/ml), followed by Evolvulus alsinoides (IC50 33.39 microg/ml) and Cynodon dactylon (IC50 78.62 microg/ml). The relative antioxidant capacity for the water infusions was observed in the following order: E. alsinoides (IC50 172.25 microg/ml)>C. dactylon (IC50 273.64 microg/ml)>S. cordifolia (IC50 342.82 microg/ml). The results of water infusions of the plants on lipid peroxidation were as follows: E. alsinoides (IC50 89.23 microg/ml)>S. cordifolia) (IC50 126.78 microg/ml)>C. dactylon (IC50 608.31 microg/ml).

[Spermatic cord rhabdomyoma]. / Rabdomioma de cordón espermático.

OBJECTIVE: Rhabdomyomas are benign tumors of the skeletal muscle and extracardiac rhabdomyomas are very rare. METHODS/RESULTS: We report one case of spermatic cord rhabdomyoma in a 28-year-old male. CONCLUSIONS: Genital rhabdomyomas are rare benign tumors. Rhabdomyomas should be considered in the clinicopathological differential diagnosis of tumors of the male genital tract.

Transformation of the oomycete pathogen Phytophthora megasperma f. sp. glycinea occurs by DNA integration into single or multiple chromosomes.

A procedure for stable transformation was developed for Phytophthora megasperma f. sp. glycinea, an oomycete pathogen of soybean. Transformants were obtained using a bacterial hygromycin resistance gene fused to a promoter and terminator from the ham34 gene of another oomycete, Bremia lactucae. Vector DNA, alone or complexed to cationic liposomes, was introduced into protoplasts using polyethylene glycol and CaCl2. DNA and RNA hybridization, and phosphotransferase assays, confirmed the presence and expression of vector DNA in the transformants. Hybridization to electrophoretically separated chromosomes of P. m. glycinea showed that vector DNA had integrated into only one chromosome in four transformants, and into multiple chromosomes in one transformant.

The computed tomographic appearance of the spinal cord in diastematomyelia.

The myelographic and computed tomographic findings in 10 patients with diastematomyelia were reviewed. In all patients, including seven with osseous spurs, the hemicords were smaller than the normal cord above or below the cleft. The narrow hemicords distinguish diastematomyelia from diplomyelia.

Full- or half-cycle treatment of severe premenstrual syndrome with a serotonergic antidepressant.

Evidence that serotonergic antidepressants are effective for treating premenstrual syndrome (PMS) raises the question of whether dosing only in the symptomatic premenstrual phase is effective for this disorder. This preliminary randomized, double-blind study compared the responses to half-cycle or full-cycle dosing of sertraline in 31 patients who completed a preceding double-blind, short-term treatment trial. The subjects fulfilled criteria for severe PMS when they entered the preceding controlled trial. At the end of the short-term treatment trial, the double-blind was not broken; both improved and unimproved subjects were randomized in a double-blind fashion to receive either full-cycle or half-cycle sertraline in the 3-month extension study. Results showed that the total premenstrual scores from the Penn Daily Symptom Report (DSR) were lower in the half-cycle dosing group in each of the 3 treatment months but did not differ with statistical significance from the full-cycle dosing group. Further analysis of the 17 DSR items showed that mood swings, nervous tension, feeling out of control, and confusion were significantly lower (p < 0.05) at endpoint in the half-cycle dosing group. Overall, subjects who improved in prior treatment remained improved; approximately half the subjects who were unimproved at entry into the extension study improved, regardless of the dosing regimen. The results add support to other preliminary reports of efficacy of serotonergic antidepressants administered premenstrually and indicate the clinical importance of determining an optimal dose/benefit ratio of serotonergic antidepressants for PMS patients.

Accuracy and intraobserver variability of simulated cervical dilatation measurements.

OBJECTIVE: Our purpose was to assess the accuracy and intraobserver variability of clinical cervical diameter measurements among obstetric health care providers. STUDY DESIGN: Polyvinyl chloride pipes 1 to 10 cm in diameter were mounted in cardboard boxes and used to simulate cervical examinations. The boxes were designed so that the examiner had to rely solely on proprioception to determine the inner diameter. RESULTS: A total of 1574 simulated cervical diameter measurements were obtained from 102 different examiners in a two-part study. The overall accuracy for determining the exact diameter was 56.3%, which improved to 89.5% when an error of +/- 1 cm was allowed. Intraobserver variability for a given diameter measurement was 52.1%, which decreased to 10.5% when an error of +/- 1 cm was allowed. CONCLUSIONS: Cervical diameter measurements obtained by digital examination are precise when an error of +/- 1 cm is allowed for. Intraobserver variability is > 50% and is an important consideration when evaluating dysfunctional labor.

Neuroprotection by flavonoids

The high morbidity, high socioeconomic costs and lack of specific treatments are key factors that define the relevance of brain pathology for human health and the importance of research on neuronal protective agents. Epidemiological studies have shown beneficial effects of flavonoids on arteriosclerosis-related pathology in general and neurodegeneration in particular. Flavonoids can protect the brain by their ability to modulate intracellular signals promoting cellular survival. Quercetin and structurally related flavonoids (myricetin, fisetin, luteolin) showed a marked cytoprotective capacity in in vitro experimental conditions in models of predominantly apoptotic death such as that induced by medium concentrations (200 æM) of H2O2 added to PC12 cells in culture. Nevertheless, quercetin did not protect substantia nigra neurons in vivo from an oxidative insult (6-hydroxydopamine), probably due to difficulties in crossing the blood-brain barrier. On the other hand, treatment of permanent focal ischemia with a lecithin/quercetin preparation decreased lesion volume, showing that preparations that help to cross the blood-brain barrier may be critical for the expression of the effects of flavonoids on the brain. The hypothesis is advanced that a group of quercetin-related flavonoids could become lead molecules for the development of neuroprotective compounds with multitarget anti-ischemic effects.