Development and validation of a successful microbiological agar assay for determination of ceftriaxone sodium in powder for injectable solution.

Ceftriaxone sodium is a cephalosporin with broad-spectrum antimicrobial activity and belongs to the third generation of cephalosporins. Regarding the quality control of medicines, a validated microbiological assay for the determination of ceftriaxone sodium in powder for injectable solution has not been reported yet. This paper reports the development and validation of a simple, accurate and reproducible agar diffusion method to quantify ceftriaxone sodium in powder for injectable solution.

The stress-induced cytokine interleukin-6 decreases the inhibition/excitation ratio in the rat temporal cortex via trans-signaling.

Background: Although it is known that stress elevates the levels of pro-inflammatory cytokines and promotes hyper-excitable central conditions, a causal relationship between these two factors has not yet been identified. Recent studies suggest that increases in interleukin 6 (IL-6) levels are specifically associated with stress. We hypothesized that IL-6 acutely and directly induces cortical hyper-excitability by altering the balance between synaptic excitation and inhibition.

Extracting regulatory networks of Escherichia coli from RegulonDB.

RegulonDB contains the largest and currently best-known data set on transcriptional regulation in a single free-living organism, that of Escherichia coli K-12 (Gama-Castro et al. Nucleic Acids Res 36:D120-D124, 2008). This organized knowledge has been the gold standard for the implementation of bioinformatic predictive methods on gene regulation in bacteria (Collado-Vides et al.

A discriminating dissolution method for glimepiride polymorphs.

Glimepiride, an oral antidiabetic drug, is practically insoluble in water and exists in two polymorphic forms, I and II, of which form II has higher solubility in water. Because the dissolution rate of drugs can depend on the crystal form, there is a need to develop discriminating dissolution methods that are sensitive to changes in polymorphic forms. In this work, a dissolution method for the assessment of 4 mg glimepiride tablets was developed and validated.

Can Wistar rats be used as the normotensive controls for nerve morphometry investigations in spontaneously hypertensive rats (SHR)?

Purpose: We compared the sural nerve morphology among Wistar (WR), Wistar-Kyoto (WKY) and Spontaneously hypertensive (SHR) rats, including the nerve fascicles and myelinated fibers morphometry.

Methods: Age matched (20 weeks) female WR (N=6), WKY (N=6) and SHR (N=7) had their right and left sural nerves removed, embedded in epoxy resin, and observed by light microscopy. Morphometric analysis was performed with the aid of computer software.

Changes in autonomic control of the cardiovascular system in the Wistar audiogenic rat (WAR) strain.

We evaluated autonomic cardiovascular modulation and baroreflex control of heart rate (HR) in a particular epileptic rat strain, Wistar audiogenic rats (WARs). We studied spontaneous baroreflex sensitivity as well as reflex changes in HR evoked by phenylephrine/nitroprusside-induced changes in arterial pressure (AP). Atropine and propranolol were used to measure cardiac autonomic tone.

Role of cGMP and cAMP in the hemodynamic response to intrathecal sildenafil administration.

Introduction: Results from our laboratory have demonstrated that intracerebroventricular administration of sildenafil to conscious rats promoted a noticeable increase in both lumbar sympathetic activity and heart rate, with no change in the mean arterial pressure. The intracerebroventricular administration of sildenafil may have produced the hemodynamic effects by activating sympathetic preganglionic neurons in the supraspinal regions and spinal cord. It is well documented that sildenafil increases intracellular cGMP levels by inhibiting phosphodiesterase type 5 and increases cAMP levels by inhibiting other phosphodiesterases.

Pre- and postsynaptic effects of norepinephrine on γ-aminobutyric acid-mediated synaptic transmission in layer 2/3 of the rat auditory cortex.

Noradrenergic terminals from the locus coeruleus release norepinephrine (NE) throughout most brain areas, including the auditory cortex, where they affect neural processing by modulating numerous cellular properties including the inhibitory γ-aminobutyric acid (GABA)ergic transmission. We recently demonstrated that NE affects GABAergic signaling onto cortical pyramidal cells in a complex manner. In this study, we used a combination of patch-clamp recording and immunohistochemical techniques to identify the synaptic site and the location of the adrenergic receptors involved in the modulation of GABAergic signaling in cortical layer 2/3 of the rat.

Chemical and antidiarrheal studies of Plinia cauliflora.

Plinia cauliflora (Mart.) Kausel, widespread in South America, has edible fruits, and its bark is commonly used against diarrhea and other disorders, on account of its astringency. Because diarrhea is still one of the most important causes of illness and death among children in developing countries, where the population turns to traditional medicine for its treatment, the present study determined the composition of fruit and leaf extracts of P.

Comparison of HPLC and UV spectrophotometric methods for the determination of cefuroxime sodium in pharmaceutical products.

This paper describes the development and evaluation of a HPLC and UV spectrophotometric methods to quantify cefuroxime sodium in injectables. HPLC analysis were carried out using a C18 Wat 054275 column and a mobile phase composed of methanol and water (70:30), with a flow rate of 0.8 mL/min and UV detection at 280 nm.

Effect of baroreceptor denervation on the autonomic control of arterial pressure in conscious mice.

This study evaluated the role of arterial baroreceptors in arterial pressure (AP) and pulse interval (PI) regulation in conscious C57BL mice. Male animals, implanted with catheters in a femoral artery and a jugular vein, were submitted to sino-aortic (SAD), aortic (Ao-X) or carotid sinus denervation (Ca-X), 5 days prior to the experiments. After basal recording of AP, the lack of reflex bradycardia elicited by administration of phenylephrine was used to confirm the efficacy of SAD, and cardiac autonomic blockade with methylatropine and propranolol was performed.

Morphometric analysis of the phrenic nerve in male and female Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR).

Ventilatory differences between rat strains and genders have been described but the morphology of the phrenic nerve has not been investigated in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. A descriptive and morphometric study of the phrenic nerves of male (N = 8) and female (N = 9) SHR, and male (N = 5) and female (N = 6) WKY is presented. After arterial pressure and heart rate recordings, the phrenic nerves of 20-week-old animals were prepared for epoxy resin embedding and light microscopy.

Effect of Glycolic Extract of Dillenia indica L. Combined With Microcurrent Stimulation on Experimental Lesions in Wistar Rats.

Unlabelled: This study evaluated the wound healing activity of a glycolic extract of Dillenia indica (GED) prepared from the mature fruits of the plant applied alone or in combination with microcurrent stimulation to skin wounds surgically induced on the back of Wistar rats.

Methods: The animals were randomly divided into six groups: (A) negative control group; (B) group receiving microcurrent application (MC; [10 mA/2 mins]); (C) group treated with GED; (D) group treated with an emulsion containing GED; (E) group treated with GED and MC, and (F) group treated with the emulsion containing GED and MC. Tissue samples were obtained 2, 6, and 10 days after injury and underwent structural and morphometric analysis.

Antidiarrheal activity of Campomanesia xanthocarpa fruit.

The growing list of drug-resistant microorganisms and the persistence of deaths due to diarrhea are compelling reasons to study plants in search of new therapeutic agents. The chemical constitution and popular use of the edible fruits of Campomanesia xanthocarpa O. Berg motivated this study to assess the antimicrobial and antidiarrheal properties of the fruits.

Evaluation of preservative effectiveness of liquid crystalline systems with retynil palmitate by the challenge test and D-value.

The objective of this work was to evaluate the preservative effectiveness of liquid crystalline systems containing retynil palmitate (RP) by the challenge test (CT) and D-value. A system was developed containing water, silicon glycol copolymer, and polyether functional siloxane with 1% RP added. The analyses were carried out by methods in the U.

Assessing neuropsychological performance in a migrant farm working Colonia in Baja California, Mexico: a feasibility study.

Neuropsychological impairments (NPI) can lead to difficulties in daily functioning and ultimately contribute to poor health outcomes. However, evidence for the feasibility of NPI assessment in resource-limited settings using tests developed in high literacy/high education cultures is sparse. The main objectives were to: (1) determine the feasibility and appropriateness of conducting neuropsychological assessments among a migrant farm worker population in Baja California, Mexico and (2) preliminary describe neuropsychological test performance in this unique population.

Development and validation of a microbiological agar assay for determination of orbifloxacin in pharmaceutical preparations.

Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations.

Methods for exploring the morpho-functional relations of the aortic depressor nerve in experimental diabetes.

The present study investigated morpho-functional relations of the aortic depressor nerve (ADN) 5, 15 and 120 days after the onset of streptozotocin-induced diabetes in rats. Time control animals received vehicle. Under pentobarbital anesthesia, ADN activity was recorded simultaneously with arterial pressure.

Role of the spinal cord NO/cGMP pathway in the control of arterial pressure and heart rate.

The modulatory effect of nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway on sympathetic preganglionic neurons still deserves further investigation. The present study was designed to examine the role of the spinal cord NO/cGMP pathway in controlling mean arterial pressure and heart rate. We observed that intrathecal administration of the NO synthase inhibitor Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) causes an increase in mean arterial pressure but does not affect heart rate.

Hemodynamic responses to aortic depressor nerve stimulation in conscious L-NAME-induced hypertensive rats.

The present study investigated whether baroreflex control of autonomic function is impaired when there is a deficiency in NO production and the role of adrenergic and cholinergic mechanisms in mediating reflex responses. Electrical stimulation of the aortic depressor nerve in conscious normotensive and nitro-l-arginine methyl ester (L-NAME)-induced hypertensive rats was applied before and after administration of methylatropine, atenolol, and prazosin alone or in combination. The hypotensive response to progressive electrical stimulation (5 to 90 Hz) was greater in hypertensive (-27 ± 2 to -64 ± 3 mmHg) than in normotensive rats (-17 ± 1 to -46 ± 2 mmHg), whereas the bradycardic response was similar in both groups (-34 ± 5 to -92 ± 9 and -21 ± 2 to -79 ± 7 beats/min, respectively).

RegulonDB version 7.0: transcriptional regulation of Escherichia coli K-12 integrated within genetic sensory response units (Gensor Units).

RegulonDB (http://regulondb.ccg.unam.

Ovariectomy does not affect the cardiac sympathovagal balance of female SHR but estradiol does.

The low incidence of cardiovascular diseases, including hypertension, in premenopausal women has led to the conclusion that ovarian hormones may have a protective effect on the cardiovascular system. We evaluated the effects of ovariectomy and/or estradiol on sympathovagal balance and heart rate variability (HRV) in female spontaneously hypertensive rats (SHR) with tachycardia and compared them to Wistar rats (12 weeks old; N = 8-12). Ovariectomy (OVX) and/or estradiol (10 µg/kg) did not affect basal arterial pressure in either rat strain, but estradiol increased basal heart rate (HR) in OVX SHR (454 ± 18 vs 377 ± 9 bpm).

Theoretical and empirical quality assessment of transcription factor-binding motifs.

Position-specific scoring matrices (PSSMs) are routinely used to predict transcription factor (TF)-binding sites in genome sequences. However, their reliability to predict novel binding sites can be far from optimum, due to the use of a small number of training sites or the inappropriate choice of parameters when building the matrix or when scanning sequences with it. Measures of matrix quality such as E-value and information content rely on theoretical models, and may fail in the context of full genome sequences.

Baroreceptor and chemoreceptor contributions to the hypertensive response to bilateral carotid occlusion in conscious mice.

This study aimed to characterize the role played by baroreceptors and chemoreceptors in the hypertensive response to bilateral carotid occlusion (BCO) in conscious C57BL mice. On the day before the experiments the animals were implanted with pneumatic cuffs around their common carotid arteries and a femoral catheter for measurement of arterial pressure. Under the same surgical approach, groups of mice were submitted to aortic or carotid sinus denervation or sham surgery.

Dynamic modulation of short-term synaptic plasticity in the auditory cortex: the role of norepinephrine.

Norepinephrine (NE) is an important modulator of neuronal activity in the auditory cortex. Using patch-clamp recording and a pair pulse protocol on an auditory cortex slice preparation we recently demonstrated that NE affects cortical inhibition in a layer-specific manner, by decreasing apical but increasing basal inhibition onto layer II/III pyramidal cell dendrites. In the present study we used a similar protocol to investigate the dependence of noradrenergic modulation of inhibition on stimulus frequency, using 1s-long train pulses at 5, 10, and 20 Hz.