L-Dopa release from mesoporous silica nanoparticles engineered through the concept of drug-structure-directing agents for Parkinson's disease.

Parkinson's disease (PD) is a progressive neurodegenerative disease, the 2nd most common after Alzheimer's disease, the main effect of which is the loss of dopaminergic neurons. Levodopa or l-Dopa is an amino acid used in the treatment of PD that acts as the immediate precursor to dopamine. However, over time the efficacy of the medication gradually decreases requiring modified delivery methods. One of the major challenges for the medication to work is to achieve a gradual continuous supply of l-Dopa to the brain to minimise symptoms. Herein, mesoporous silica nanoparticles (MSNs) were engineered through the concept of drug-structure-directing agents (DSDAs) with inherent therapeutic activity. The DSDA used was l-Dopa drug modified by amidation with fatty acids to build anionic surfactants that were able to form micelles as templates for the assembly of inorganic precursors to form the silica framework. This templating route produced MSNs with tunable sizes ranging from 100 nm to 1 µm and with different shapes: spherical, with either solid structures with radial mesopores and porous shells, or hollow-shells with inside large void cavities; and elongated, characterized by long hollows covered by mesoporous shells. The concept of using DSDAs to synthesize drug nanocarriers can be used to avoid the surfactant removal and subsequent drug loading steps involved in the synthesis of conventional MSNs. We hypothesized that the l-Dopa released from MSN materials is mediated by the size and solubility of the DSDAs, and the surface chemical interactions between the DSDAs and MSN hosts. Different pHs (acidic and neutral) simulating gastrointestinal tract conditions were tested, and the results showed hardly any release for gastric conditions at pH 1.2, avoiding the premature release in the stomach typical of conventional MSNs, while for intestinal conditions of pH 7.4, the release of l-Dopa occurred in a continuous and sustained manner, which is well suited to the drug's application and delivery route, and matches well with achieving a sustained l-Dopa delivery to relief symptoms. This could open up new uses for MSNs synthesized by this approach to treat PD.

Influence of the structural and textural properties of ordered mesoporous materials and hierarchical zeolitic supports on the controlled release of methylprednisolone hemisuccinate.

To alleviate the chronic inflammation, nasal obstruction, and loss of sense of smell that produces the rhinosinusitis disease, ordered mesoporous materials and hierarchical zeolites could be used for slow and sustained corticoid (methylprednisolone hemisuccinate conjugate) release. The correlations between the delivery performance of methylprednisolone hemisuccinate and the physicochemical properties of carriers' release systems, including pore mesostructure, texture and size, and surface chemistry, have been well established. Different two-dimensional (2-D) and three-dimensional (3-D) mesostructured materials (MCM-41, SBA-15, expanded SBA-15, FDU-12, and SBA-16) were employed. In addition, for the first time to the best of our knowledge, materials based on hierarchical zeolites with additional mesoporosity (h-ZSM-5 and h-BETA zeolites) were also tested. In particular, two materials (3-D cubic mesoporous silica SBA-16 and hierarchical Beta zeolite) have been probed to be potential candidates, exhibiting high drug adsorption capacities and slow drug release rates, which is the most favourable way of drug release in the particular rhinosinusitis application. Solid-state 1H-29Si HETCOR NMR analyses confirm the strong interactions of the drug with the surface of h-BETA and 3-D SBA-16 materials, via hydrogen bonding of carboxylic, ketone, and aliphatic moieties of the methylprednisolone hemisuccinate at surface silanol sites. Because of the remarkable release performance, it is expected that 3-D mesoporous silica SBA-16 and hierarchical Beta zeolite can be attractive candidates for current applications in nasal inflammation treatments. The drug release rate can be further retarded by decreasing the pH to around 4.6; at this point more attraction forces were detected as proved by zeta-potential measurements. Therefore, a slower delivery trend of methylprednisolone hemisuccinate has been observed for all the materials, which is more pronounced in the case of SBA-15 and SBA-16.

Amperometric determination of dipyrone in pharmaceutical formulations with a flow cell containing gold electrodes from recordable compact discs.

A simple, rapid, and precise amperometric method for quantification of dipyrone in pharmaceutical formulations is presented. The proposed method permits determinations in the 10(-7) mol L(-1) of the analyte and enables 90 determinations h(-1), employing only 100 microL of sample per determination. This method is based on the direct quantification of dipyrone in many pharmaceutical products, avoiding cumbersome processes such as previous separations, solvent extraction, or sample filtration. This new procedure was applied to commercial pharmaceutical tablets, and the results obtained were in excellent agreement with the ones obtained by the classical iodometric method.

Gold electrodes from compact discs modified with platinum for amperometric determination of ascorbic acid in pharmaceutical formulations.

A simple, rapid and precise amperometric method has been developed for quantification of ascorbic acid (AA) in pharmaceutical formulations using flow-injection analysis (FIA). A slice of recordable compact disc (CD) modified by electrodeposition of platinum was employed as the working electrode. The proposed flow system allows determinations in the 1 mumol l(-1) of the analyte and enables 90 determinations per h, employing only 150-mul sample. The method permits the direct quantification of ascorbic acid in many pharmaceutical products, avoiding cumbersome processes as previous separations, solvent extraction or sample filtration. This new procedure was applied to commercial pharmaceutical tablets and the results obtained were identical than the ones obtained by the classical iodometric method. The calibration plots for freshly prepared ascorbic acid standards were highly linear in the concentration range of 1-10 mumol l(-1) with a relative standard deviation (R.S.D.) <1%. For all real samples studied, the deviations were situated between 0.5 and 8.7%.

A new quantitative method for the diagnosis of right ventricular hypertensive disorders in 3 dimensions.

UNLABELLED: A new 3-dimensional (3D) method is described for the diagnosis of normal and hypertensive right ventricular (RV) conditions on the basis of similarity of RV structure to models of normal average shape or hypertensive average shape. Right ventricular quantification in multiple views (coronal, sagittal, and transverse) was obtained by measuring tangent angle differences (TADs) between RV tracings and average shapes at 128 points around the ventricular contour in each view. The TAD measurements of all views were then combined to quantify the closest 3D fit of the ventricle to a normal or hypertensive model. RESULTS: In 24 lamb casts measured in vitro, an accurate diagnosis was obtained in 11 of 12 normotensive casts (specificity 92%) and 11 of 12 hypertensive casts (sensitivity 92%). CONCLUSION: Accurate 3D diagnosis of in vitro normotensive and hypertensive RV conditions can be realized by measuring the TADs between the ventricle and average-shaped models.

Mental health care for Hispanic Americans: a current perspective.

In this article, the authors review patterns and challenges in the conceptualization, implementation, and academic support of the mental health services of Hispanic Americans. A critical analysis was conducted on information obtained through manual and computerized searches of published literature and conference reports. New clinical care approaches include the DSM-IV's cultural formulation with its complement of standardized multiaxial diagnosis, integration of services across clinical disorders or conditions and across sources of care, as well as pluralistic criteria and judges for service outcome appraisal. Emerging clinical approaches offer an opportunity to enhance the mental health care of Hispanic Americans within an increasingly multicultural U.S. society.

Pseudocyesis in organic mood disorders. Six cases.

Pseudocyesis, the delusion of pregnancy, has had an uncertain nosology, primarily because of the concentration on the content of the beliefs and lack of interest in the underlying phenomenology. Six patients with a major mood disorder caused by cerebral dysfunction are presented in this article. The delusion is reviewed with respect to the entities it overlaps, and the clinical manifestations are related to the mood disorders. Although no clear neuroanatomic localization was possible with this group of patients, there may be some association with desomatization caused by parietal lobe dysfunction.

Trauma torácico y ventilación mecánica independiente diferencial / Thoracic trauma and differential independent mechanical ventilation

Presentamos un caso de un paciente que sufre politraumatismo, incluyendo un trauma raquimedular con paraplejia con nivel motor T9 y traumatismo torácico predominante unilateral con atelectasia masiva del pulmón izquierdo, refractaria al tratamiento habitual, incluyendo ventilación mecánica con PEEP que respondió favorablemente a la aplicación de ventilación mecánica diferencial asincrónica. Este es un método si bien, excepcional, que puede ser de franca utilidad en la resolución terapéutica de patología pulmonar unilateral como en nuestro caso

Brief reactive psychosis.

A careful reevaluation of 24 patients diagnosed as suffering brief reactive psychosis failed to validate this diagnosis according to DSM-III criteria. Fourteen of the patients had other psychiatric disorders that could explain their symptoms, and 8 had psychosis lasting longer than 2 weeks; the precipitating events were unclear or had uncertain relationships to the psychoses. The criteria proposed for the DSM-III-R do not facilitate the diagnosis of brief reactive psychosis but perhaps make it even more confusing.

Graduates of foreign medical schools in American psychiatry.

Members of the American Psychiatric Association who graduated from foreign medical schools, currently 25 percent of APA membership, are increasingly integrating themselves into the mainstream of American psychiatry. Nevertheless, an APA survey of members who are foreign medical graduates (FMGs) conducted in 1984 indicates that FMGs continue to pass the American Board of Psychiatry and Neurology examination and to be awarded APA fellowships at a significantly lower rate than their U.S.-trained counterparts. Solutions to these disparities have been increasingly sought by the leaders of APA, especially those of the association's areas II, IV, and V, where FMGs are concentrated. The higher percentage of women among FMGs than among U.S.-trained psychiatrists and the increasing presence of Americans and Canadians among FMGs are likely to enhance pressure to solve the problems of FMGs.

Postpartum psychosis as a discrete entity.

Twelve patients with postpartum psychosis treated over a period of 18 years by 11 different psychiatrists appeared to suffer from a homogeneous disorder, with similar onset, clinical picture, course, and immediate prognosis. This observation, together with reports by other authors, suggests that postpartum psychosis deserves a place in the psychiatric nomenclature other than as "atypical psychosis."

Use of medicinal plants by ambulatory patients in Puerto Rico.

The use of medicinal plants by the patients at the outpatient clinics of five health-care centers in Puerto Rico was evaluated. Medication histories were obtained for 802 patients ranging in age from two months to 91 years. The most frequent medical diagnosis was cardiovascular disease (54% of the patients). Respiratory and digestive disorders were the least frequent conditions, identified in only 9% and 6% of the cases, respectively. Medicinal plants were used by 57% of the population. Patients 65 years or older tended to use herbal remedies more often. Seven of the 11 most commonly used plants were used to treat gastrointestinal disorders. Other medicinal uses given were for sedation, sleep disorders, elevated blood pressure, kidney disorders, and respiratory ailments. The most frequently used plant was Citrus aurantium L. (sour orange), which was used as a sedative by 39% of the patients and for gastrointestinal disorders by 17%. Two potentially toxic plants, Solanum americanum and Annona muricata, were among the most commonly used plants. Medicinal plants were used widely by the outpatient population studied. Most herbs were used to treat self-limiting conditions but some were used to treat potentially serious medical problems, such as hypertension.