Avaliação da qualidade e equivalência farmacêutica de comprimidos contendo 10mg de sinvastatina / Assessment of quality and pharmaceutical equivalence of 10 mg simvastatin tablets

A sinvastatina, pertencente à classe das estatinas, é um importante fármaco redutor do colesterol e é encontrada comercialmente como medicamentos referência, genéricos e similares em diferentes dosagens, sendo a de 10 mg a mais comum. Este trabalho tem como objetivo avaliar a qualidade e a equivalência entre comprimidos de sinvastatina 10 mg comercializados no mercado brasileiro. Foram selecionados dois medicamentos similares, um genérico e referência. Os ensaios de controle de qualidade aplicados foram: determinação do peso médio, dureza, friabilidade, desintegração, teor de princípio ativo, uniformidade de conteúdo e dissolução in vitro. Para tanto, foi necessário desenvolvimento e validação de metodologia por espectrofotometria na região do ultravioleta (UV). As formulações apresentaram-se dentro dos limites preconizados para todas as análises. No entanto, quando analisou-se estatisticamente os perfis de dissolução, verificou-se a não equivalência entre os medicamentos similares e o de referência. Porém, através dos resultados obtidos, podemos evidenciar a equivalência entre o genérico e o de referência, sugerindo sua intercambialidade...

Simvastatin, a well-known medicine of the statin class, is used therapeutically for the reduction of cholesterol and is commercially available in reference, similar and generic forms, in various doses, the tablet of 10 mg being the commonest in prescriptions. The purpose of this study was to test the quality and the pharmaceutical equivalence of tablets containing 10 mg of simvastatin available on the Brazilian market. One generic, one reference and two similar dosage forms were selected. The quality-control variables used were: weight variation, hardness, friability, disintegration, content of the active principle, content uniformity and dissolution in vitro. A UV-spectrophotometric method was developed and validated. All formulations were approved in the quality analysis. By using mathematical and statistical models, it was observed that the dissolution profiles of the similar dosage forms were not equivalent to that of the reference. On the other hand, when the generic medicine was compared with the reference, their interchangeability was confirmed...

The control of precerebellar neuron migration by RNA-binding protein Csde1.

Neuronal migration during brain development sets the position of neurons for the subsequent wiring of neural circuits. To understand the molecular mechanism regulating the migrating process, we considered the migration of mouse precerebellar neurons. Precerebellar neurons originate in the rhombic lip of the hindbrain and show stereotypic, long-distance tangential migration along the circumference of the hindbrain to form precerebellar nuclei at discrete locations. To identify the molecular components underlying this navigation, we screened for genes expressed in the migrating precerebellar neurons. As a result, we identified the following three genes through the screening; Calm1, Septin 11, and Csde1. We report here functional analysis of one of these genes, Csde1, an RNA-binding protein implicated in the post-transcriptional regulation of a subset of cellular mRNA, by examining its participation in precerebellar neuronal migration. We found that shRNA-mediated inhibition of Csde1 expression resulted in a failure of precerebellar neurons to complete their migration into their prospective target regions, with many neurons remaining in migratory paths. Furthermore, those that did reach their destination failed to invade the depth of the hindbrain via radial migration. These results have uncovered a crucial role of Csde1 in the proper control of both radial and tangential migration of precerebellar neurons.

IgA pemphigus with paraneoplastic pemphigus-like clinical features showing IgA antibodies to desmoglein 1/3 and desmocollin 3, and IgG and IgA antibodies to the basement membrane zone.

A 79-year-old Japanese woman presented with severe recalcitrant erosions on her oral mucosa, resembling paraneoplastic pemphigus. Using indirect immunofluorescence, we detected IgA antibodies against the cell surface, and both IgG and IgA antibodies against the basement membrane zone. Immunoblotting showed that the IgG antibodies reacted weakly with bullous pemphigoid 230 and periplakin, whereas the IgA antibodies did not react with any antigen. IgA antibodies to both desmoglein (Dsg)1 and Dsg3 were detected by ELISA. IgA antibodies to desmocollin (Dsc)3 were also detected by using cDNAs for human Dsc1-3 transfected into COS-7 cells. Despite treatment with oral prednisolone, high-dose intravenous immunoglobulin and double-filtration plasmapheresis, the skin lesions remained active, and the patient died from bronchiolitis obliterans-like respiratory failure. Despite extensive investigations and postmortem examination, no underlying neoplasms were found. The complex immunopathological findings probably played an important role in the development of the patient's unusual clinical features.

Comparação da digestibilidade de um alimento seco extrusado entre cães adultos e filhotes / Digestibility of dry extruded food in adult dogs and puppies

Os diversos alimentos completos para cães existentes no mercado objetivam atender as necessidades nutricionais do animal quanto ao estádio fisiológico, conforme as alterações que possam ocorrer no aproveitamento dos nutrientes. Com a finalidade de comparar os coeficientes de digestibilidade aparente (CDA) e as características das fezes de um alimento seco extrusado de cães adultos e filhotes, foram utilizados 12 cães da raça Beagle, sendo seis adultos, cinco anos, e seis filhotes, cinco-seis meses, mantidos em gaiolas metabólicas e distribuídos em delineamento inteiramente ao acaso. Os animais foram alimentados duas vezes ao dia com um alimento completo seco extrusado para filhotes, por um período de adaptação de cinco dias seguidos por cinco dias de coleta total de fezes. Houve diferença apenas para o CDA do extrato etéreo em hidrólise ácida, sendo maior para os filhotes - 95,3 vs 89,5 por cento. Em relação às características das fezes, os filhotes apresentaram pior escore fecal, devido às fezes terem se mostrado mais úmidas, além de maior pH em fezes secas e maior teor de amônia, culminando em pior qualidade. Conclui-se que filhotes de 5-6 meses de idade apresentam maior digestibilidade da gordura quando comparado a cães adultos, porém defecam fezes com pior escore fecal.

Development, validation and stability study of pediatric atenolol syrup.

Atenolol [4-(2-hydroxy-isopropylaminopropoxy)-phenylacetamide], is a cardioselective beta1-adrenergic receptor blocking agent prescribed for treatment of hypertension, angina pectoris and cardiac arrhythmias. However, most of these medicines are not formulated for easy or accurate administration to children. Atenolol is unstable in solutions and therefore the development of a liquid dosage form is a significant challenge. Studies showed that the degradation rate of atenolol is dependent on the temperature, indicating higher stability at 4 degrees C. Atenolol syrup is stable for 9 days, with acceptable apearance. A second order model adequately described atenolol decomposition when stored as syrup. A stability-indicating method was developed and validated in order to evaluate these studies.

Acquired symmetrical dermal melanocytosis (naevus of Hori) developing after aggravated atopic dermatitis.

BACKGROUND: Acquired symmetrical dermal melanocytosis (ASDM) is a pigmentary disorder characterized by blue-brown macules most frequently seen on the face of young and middle-aged Asian women. ASDM developing after other skin diseases has not been previously reported. OBJECTIVES: To characterize the clinical and histopathological features of ASDM associated with atopic dermatitis (AD) and to elucidate the differences between AD-associated ASDM and idiopathic ASDM. METHODS: Sixteen patients with ASDM associated with AD were examined clinically and histopathologically and were compared with 69 patients with idiopathic ASDM. RESULTS: The AD patients associated with ASDM consisted of four men and 12 women with a mean age of 32.8 +/- 13.1 years. Most patients remembered that the pigmented macules appeared in places where refractory eczema had existed for a long time. The marked preponderance in females and the appearance in the early reproductive period were common features of AD-associated ASDM and idiopathic ASDM. AD-associated ASDM was most commonly observed on the forehead (68.8%) and on the backs of the hands (50.0%), whereas 89.9% of idiopathic ASDM was seen on the cheeks. There was no significant difference in the number of dermal melanocytes between AD-associated ASDM and idiopathic ASDM. Electron microscopic studies demonstrated many mature melanocytes and smaller numbers of immature melanocytes in the dermis. Some melanocytes were seen adjacent to mast cells. CONCLUSIONS: AD-associated ASDM does not appear to be rare in Japan. ASDM may be triggered in AD patients by sunlight exposure, some alterations in sex hormones and/or persistent cutaneous inflammation. Histamine and stem cell factor produced by mast cells may play crucial roles in the pathogenesis of AD-associated ASDM.

Light and electron microscopic study of corticorubral synapses in adult cat: evidence for extensive synaptic remodeling during postnatal development.

Spine-like dendritic protrusions (SLDPs) emanating from developing dendrites have been proposed to play an important role in early synaptogenesis. We previously analyzed synaptic termination sites on soma-dendritic membrane of newborn cats and found that corticorubral (CR) axons form synapses preferentially on SLDPs (Saito et al., 1997). In the present study, we examined CR synapses in adult cats to elucidate the maturation process of CR synapses in relation to SLDPs. Electron microscopic observation of serial thin sections of Phaseolus vulgaris-leucoagglutinin-labeled axons revealed that approximately 60% of CR terminals in adult cats formed synapses on dendritic spines. We also found that CR axons terminate on dendritic spines originating from the intermediate or distal dendrites of rubrospinal cells (more than 200 microm apart from the soma), in contrast to kittens in which CR fibers terminate on SLDPs originating from the proximal dendrites (less than 100 microm apart from the soma) of rubrospinal cells (Saito et al. [1997] J. Neurosci. 17:8792-8803). These results suggest that CR synapses undergo remarkable remodeling after initial termination on SLDP during postnatal development.

Excitatory postsynaptic potentials trigger a plateau potential in rat subthalamic neurons at hyperpolarized states.

The subthalamic nucleus (STN) directly innervates the output structures of the basal ganglia, playing a key role in basal ganglia function. It is therefore important to understand the regulatory mechanisms for the activity of STN neurons. In the present study, we aimed to investigate how the intrinsic membrane properties of STN neurons interact with their synaptic inputs, focusing on their generation and the properties of the long-lasting, plateau potential. Whole cell recordings were obtained from STN neurons in slices prepared from postnatal day 14 (P14) to P20 rats. We found that activation of glutamate receptor-mediated excitatory synaptic potentials (EPSPs) evoked a plateau potential in a subpopulation of STN neurons (n = 13/22), in a voltage-dependent manner. Plateau potentials could be induced only when the cell was hyperpolarized to more negative than about -75 mV. Plateau potentials, evoked with a depolarizing current pulse, again only from a hyperpolarized state, were observed in about half of STN neurons tested (n = 162/327). Only in neurons in which a plateau potential could be evoked by current injection did EPSPs evoke plateau potentials. L-type Ca(2+) channels, Ca(2+)-dependent K(+) channels, and TEA-sensitive K(+) channels were found to be involved in the generation of the potential. The stability of the plateau potential, tested by the injection of a negative pulse current during the plateau phase, was found to be robust at the early phase of the potential, but decreased toward the end. As a result the early part of the plateau potential was resistant to membrane potential perturbations and would be able to support a train of action potentials. We conclude that excitatory postsynaptic potentials, evoked in a subpopulation of STN neurons at a hyperpolarized state, activate L-type Ca(2+) and other channels, leading to the generation of a plateau potential. Thus about half of STN neurons can transform short-lasting synaptic excitation into a long train of output spikes by voltage-dependent generation of a plateau potential.

Crossing the floor plate triggers sharp turning of commissural axons.

During development of the vertebrate CNS, commissural axons initially grow circumferentially toward the ventral midline floor plate. After crossing the floor plate, they abruptly change their trajectory from the circumferential to the longitudinal axis. Although recent studies have unraveled the mechanisms that control navigation of these axons along the circumferential axis, those that result in the transition from circumferential to longitudinal trajectory remain unknown. Here, we examined whether an interaction with the floor plate is a prerequisite for the initiation of trajectory transition of commissural axons, using in vitro preparations of the rat metencephalon. We found that commissural axons in the metencephalon, once having crossed the floor plate, turned sharply to grow longitudinally. In contrast, axons extending in floor plate-deleted preparations, continued to grow circumferentially, ignoring the hypothetical turning point. These results suggest that a prior interaction of commissural axons with floor plate cells is a key step for these axons to activate a navigation program required for their change in axonal trajectory from the circumferential to the longitudinal axis.

HBV-related fulminant hepatic failure: successful intensive medical therapy in a candidate for liver transplantation.

Fulminant hepatic failure (FHF) usually has a fatal prognosis without liver transplantation. We describe the case of a woman who developed FHF, and was evaluated as a candidate for liver transplantation, but who was cured without transplantation through intensive medical care that included glucagon-insulin therapy, methylprednisolone pulse therapy, interferon beta and lamivudine administration, cyclosporine administration, and high-volume hemodiafiltration and plasma exchange. In a patient with FHF who is a candidate for liver transplantation but for whom the transplantation cannot be performed for some reason, intensive medical therapy, including regeneration-promoting therapy, immunosuppressive therapy, antiviral therapy, and vigorous hepatic support, should be carried out.

Visualization, direct isolation, and transplantation of midbrain dopaminergic neurons.

To visualize and isolate live dopamine (DA)-producing neurons in the embryonic ventral mesencephalon, we generated transgenic mice expressing green fluorescent protein (GFP) under the control of the rat tyrosine hydroxylase gene promoter. In the transgenic mice, GFP expression was observed in the developing DA neurons containing tyrosine hydroxylase. The outgrowth and cue-dependent guidance of GFP-labeled axons was monitored in vitro with brain culture systems. To isolate DA neurons expressing GFP from brain tissue, cells with GFP fluorescence were sorted by fluorescence-activated cell sorting. More than 60% of the sorted GFP(+) cells were positive for tyrosine hydroxylase, confirming that the population had been successfully enriched with DA neurons. The sorted GFP(+) cells were transplanted into a rat model of Parkinson's disease. Some of these cells survived and innervated the host striatum, resulting in a recovery from Parkinsonian behavioral defects. This strategy for isolating an enriched population of DA neurons should be useful for cellular and molecular studies of these neurons and for clinical applications in the treatment of Parkinson's disease.

The release of the substrate for xanthine oxidase in hypertensive patients was suppressed by angiotensin converting enzyme inhibitors and alpha1-blockers.

OBJECTIVE: Hyperuricemia is associated with the vascular injury of hypertension, and purine oxidation may play a pivotal role in this association, but the pathophysiology is not fully understood. We tested the hypothesis that in hypertensive patients, the excess amount of the purine metabolite, hypoxanthine, derived from skeletal muscles, would be oxidized by xanthine oxidase, leading to myogenic hyperuricemia as well as to impaired vascular resistance caused by oxygen radicals. METHODS: We investigated the production of hypoxanthione, the precursor of uric acid and substrate for xanthine oxidase, in hypertensive patients and found that skeletal muscles produced hypoxanthine in excess. We used the semi-ischemic forearm test to examine the release of hypoxanthine (deltaHX), ammonium (deltaAmm) and lactate (deltaLAC) from skeletal muscles in essential hypertensive patients before (UHT: n = 88) and after treatment with antihypertensive agents (THT: n = 37) in comparison to normotensive subjects (NT: n = 14). RESULTS: deltaHX, as well as deltaAmm and deltaLAC, were significantly higher in UHT and THT (P< 0.01) than in NT. This release of deltaHX from exercising skeletal muscles correlated significantly with the elevation of lactate in NT, UHT and THT (y = 0.209 + 0.031x; R2 = 0.222, n = 139: P < 0.01). Administration of doxazosin (n = 4), bevantolol (n = 5) and alacepil (n = 8) for 1 month significantly suppressed the ratio of percentage changes in deltaHX by -38.4 +/- 55.3%, -51.3 +/- 47.3% and -76.3 +/- 52.2%, respectively (P< 0.05) but losartan (n = 3), atenolol (n = 7) and manidipine (n = 10) did not reduce the ratio of changes; on the contrary, they increased it in deltaHX by +188.2 +/- 331%, +96.2 +/- 192.2% and +42.6 +/- 137.3%, respectively. The elevation of deltaHX after exercise correlated significantly with the serum concentration of uric acid at rest in untreated hypertensive patients (y = 0.194 - 0.255x; R2 = 0.185, n = 30: P < 0.05). The prevalence of reduction of both deltaHX and serum uric acid was significantly higher in the patients treated with alacepril, bevantolol and doxazosin (67%: P < 0.02) than in the patients treated with losartan, atenolol and manidipine (12%). CONCLUSIONS: It is concluded that the skeletal muscles of hypertensive patients released deltaHX in excess by activation of muscle-type adenosine monophosphate (AMP) deaminase, depending on the degree of hypoxia. The modification of deltaHX by angiotensin-converting enzyme inhibitors and alpha1-blockers influenced the level of serum uric acid, suggesting that the skeletal muscles may be an important source of uric acid as well as of the substrate of xanthine oxidase in hypertension.

Local nonpermissive and oriented permissive cues guide vestibular axons to the cerebellum.

Information that originates from peripheral sensory organs is conveyed by axons of cephalic sensory cranial ganglia connecting the sensory organs to appropriate central targets in the brain. Thus, the establishment of correct axonal projections by sensory afferents is one of the most important issues in neural development. Previously, we examined the development of the vestibular nerve that originates from the VIIIth ganglion using a flat whole-mount preparation of the rat hindbrain and developed an in vitro, culture preparation that can recapitulate vestibular nerve development (Tashiro, Y., Endo, T., Shirasaki, R., Miyahara, M., Heizmann, C. W. and Murakami, F. (2000) J. Comp. Neurol. 417, 491-500). Both in vivo and in vitro, the ascending branch of the VIIIth ganglion projecting to the cerebellum reaches the base of the cerebellar primordium and starts to splay out towards the rhombic lip, apparently avoiding the ventral metencephalon. We now examine the nature of cues that guide vestibulocerebellar axons by applying various manipulations to the flat whole-mount in vitro preparation. Our observations suggest that local nonpermissive cues and oriented cues play a pivotal role in the guidance of vestibular axons to their central target.

A factor XI deficiency associated with a nonsense mutation (Trp501stop) in the catalytic domain.

We identified a novel mutation in an asymptomatic 65-year-old Japanese man with severe factor XI deficiency. Sequence analysis after polymerase chain reaction single-stranded conformation polymorphism (PCR-SSCP) analysis of his factor XI gene revealed a G-->A transition in codon 501 of exon 13, resulting in a substitution of Trp501 (TGG) by a stop codon (TAG) in the catalytic domain. This mutation abolished a FokI restriction site. The PCR product from normal subjects was digested with FokI and yielded two fragments, one of 223 bp and one of 47 bp. The PCR product from the patient gave a single 270-bp fragment, demonstrating possible homozygosity.

Characterization of Ca(2+) channels in rat subthalamic nucleus neurons.

The subthalamic nucleus (STN) plays a key role in motor control. Although previous studies have suggested that Ca(2+) conductances may be involved in regulating the activity of STN neurons, Ca(2+) channels in this region have not yet been characterized. We have therefore investigated the subtypes and functional characteristics of Ca(2+) conductances in STN neurons, in both acutely isolated and slice preparations. Acutely isolated STN cells were identified by retrograde filling with the fluorescent dye, Fluoro-Gold. In acutely isolated STN neurons, Cd(2+)-sensitive, depolarization-activated Ba(2+) currents were observed in all cells studied. The current-voltage relationship and current kinetics were characteristic of high-voltage-activated Ca(2+) channels. The steady-state voltage-dependent activation curves and inactivation curves could both be fitted with a single Boltzmann function. Currents evoked with a prolonged pulse, however, inactivated with multiple time constants, suggesting either the presence of more than one Ca(2+) channel subtype or multiple inactivation processes with a single channel type in STN neurons. Experiments using organic Ca(2+) channel blockers revealed that on average, 21% of the current was nifedipine sensitive, 52% was sensitive to omega-conotoxin GVIA, 16% was blocked by a high concentration of omega-agatoxin IVA (200 nM), and the remainder of the current (9%) was resistant to the co-application of all blockers. These currents had similar voltage dependencies, but the nifedipine-sensitive current and the resistant current activated at slightly lower voltages. omega-Agatoxin IVA at 20 nM was ineffective in blocking the current. Together, the above results suggest that acutely isolated STN neurons have all subtypes of high-voltage-activated Ca(2+) channels except for P-type, but have no low-voltage-activated channels. Although acutely isolated neurons provide a good preparation for whole cell voltage-clamp study, dendritic processes are lost during dissociation. To gain information on Ca(2+) channels in dendrites, we thus studied Ca(2+) channels of STN neurons in a slice preparation, focusing on low-voltage-activated channels. In current-clamp recordings, a slow spike was always observed following termination of an injected hyperpolarizing current. The slow spike occurred at resting membrane potentials and was sensitive to micromolar concentrations of Ni(2+), suggesting that it is a low-threshold Ca(2+) spike. Together, our results suggest that STN neurons express low-voltage-activated Ca(2+) channels and several high-voltage-activated subtypes. Our results also suggest the possibility that the low-voltage-activated channels have a preferential distribution to the dendritic processes.

Dorsal spinal cord inhibits oligodendrocyte development.

Oligodendrocytes are the myelinating cells of the mammalian central nervous system. In the mouse spinal cord, oligodendrocytes are generated from strictly restricted regions of the ventral ventricular zone. To investigate how they originate from these specific regions, we used an explant culture system of the E12 mouse cervical spinal cord and hindbrain. In this culture system O4(+) cells were first detected along the ventral midline of the explant and were subsequently expanded to the dorsal region similar to in vivo. When we cultured the ventral and dorsal spinal cords separately, a robust increase in the number of O4(+) cells was observed in the ventral fragment. The number of both progenitor cells and mature cells also increased in the ventral fragment. This phenomenon suggests the presence of inhibitory factor for oligodendrocyte development from dorsal spinal cord. BMP4, a strong candidate for this factor that is secreted from the dorsal spinal cord, did not affect oligodendrocyte development. Previous studies demonstrated that signals from the notochord and ventral spinal cord, such as sonic hedgehog and neuregulin, promote the ventral region-specific development of oligodendrocytes. Our present study demonstrates that the dorsal spinal cord negatively regulates oligodendrocyte development.

Levels of interleukin (IL)-6, IL-8, and IL-1 receptor antagonist in the hepatic vein following liver surgery.

BACKGROUND/AIMS: The liver produces various cytokines, but local changes in the concentrations of these reaction products after liver surgery are unknown. We investigated the local changes of interleukin-6, interleukin-8 and interleukin-1 receptor antagonist after liver surgery. METHODOLOGY: We determined levels of interleukin-6, interleukin-8, and interleukin-1 receptor antagonist in the hepatic vein and radial artery after liver resection in 13 patients. These cytokine levels in the portal vein were also measured in 6 patients. RESULTS: Interleukin-6, interleukin-8, and interleukin-1 receptor antagonist levels were significantly increased during liver surgery (P < 0.05). The level of interleukin-6 was significantly lower in the hepatic vein than in the radial artery as well as in the portal vein at the end of the operation (P < 0.05, < 0.03). The level of interleukin-8 and interleukin-1 receptor antagonist was significantly higher in the hepatic vein than in the artery (P < 0.05). CONCLUSIONS: Interleukin-6 may be taken up by the liver after liver surgery, and the difference between hepatic venous and peripheral arterial interleukin-6 levels may be an indicator of liver regeneration after liver resection. Interleukin-8 and interleukin-1 receptor antagonist appear to be produced in the remaining liver.

[Significance of interferon alpha therapy for advanced renal cell carcinoma. Fukushima Renal Cancer Study Group].

We ranked prognostic factors to retrospectively evaluate the clinical significance of interferon alpha (IFN-alpha) therapy in patients with Robson stage IVB renal cell carcinoma. A total of 44 Robson stage IVB renal cancer patients were divided into 2 groups, one with more than 6 months administration of IFN-alpha (3-7 times a week: group A) and another without any IFN-alpha administration. The distribution of these 2 groups was not randomized. In addition to IFN-alpha therapy, survival was analyzed with respect to performance status (PS), mass reductive nephrectomy, concomitant use of other cytotoxic therapies, the number of metastatic organs, growth type, site of metastasis and the period of diagnosis, using a multivariate method with Cox proportional hazards regression. The multivariate analysis showed administration of IFN-alpha to be the most significant factor influencing a good prognosis. Improved survival was also significantly correlated with slow growing type and good PS. Among group A, a significant favorable prognosis was obtained in patients with the responses of no change (NC), partial response (PR) and complete remission (CR) 6 months after initiating administration of IFN-alpha, as well as with good PS and a slow growing type carcinoma. We conclude that IFN-alpha therapy might improve the prognosis of patients with Robson stage IVB renal cell carcinoma, especially, in cases when a greater than NC response is obtained after 6 months administration of IFN-alpha.