Prediction of plasma concentrations using in silico modelling and simulation approach: Case of Acebutolol.

PURPOSE: The aim of this study was to predict the plasma concentrations of acebutolol tablets with different dissolution profiles using computer modelling and evaluating whether they are bioequivalent using simulated population studies. METHODS: The dissolution behaviour of acebutolol was studied in the USP Apparatus-II using different dissolution media for pH 1.2, 4.5, and 6.8 at 37±0.5°C. The obtained dissolution data, as well as plasma concentration-time data of the reference product from the literature were used as inputs to build pharmacokinetic model of acebutolol within GastroPlus™ software (version 9.7, Simulations Plus Inc., Lancaster, CA, USA) to simulate the in vivo profiles of the drug. RESULTS: The dissolution profiles of the reference product Sectral® 400mg tablets and a locally produced generic product were>85% in 15min in three dissolution media. Simulation results demonstrated that the brand and generic products would show the same in vivo performance. Population simulation results of the ln-transformed 90% confidence interval for the ratio of Cmax, AUC0-t and AUC0-inf values for the two products were within the 80-125% interval, showing to be bioequivalent. CONCLUSION: Based on the in vitro results combined with in silico simulations using GastroPlus™, a biowaiver for immediate release acebutolol tablets is justified. Furthermore, computer modelling has shown to be a very intersting tool to prove the bioequivalence for these products.

[Quality control of mixtures for pediatric parenteral nutrition: Validation of sodium and potassium assay method]. / Contrôle qualité des mélanges pour nutrition parentérale pédiatriques : validation de la méthode de dosage du sodium et du potassium.

OBJECTIVES: Control of electrolyte concentration in mixtures for parenteral nutrition (MPN) for newborns is crucial before the release of the final product. We aimed to assess the validation of the electrolytes assay in MPN. METHODS: Electrolytes assay was performed with Ilyte Analyzer®. Validation of method was realized in accordance with ICH (International Conference on Harmonization) guideline Q2(R1) and the commission report of the French society of pharmaceutical science and technology. Linearity test solutions were prepared in triplicate using five levels of concentrations for sodium and potassium (60-140% of theoretical concentrations). Accuracy of the method was deducted from the same results of linearity. The intermediate precision was ensured by dosing the main electrolyte in six MPN, during three successive days. RESULTS: Linearity was assessed with correlation coefficients greater than 0.996 for both electrolytes. A non-significant result of comparison test of the intercept with zero (Student test) was obtained. A highly significant result of the test of existence of slopes (Fisher test) proved a linear regression for the 2 electrolytes (P<0.1%). Inter-day precision values were 2.68% and 2.65% respectively for sodium and potassium. CONCLUSION: The validation of sodium and potassium assay method was successfully performed with Ilyte Analyzer® allowing routine quality control in MPN.

Giant bilateral adrenal myelolipoma with congenital adrenal hyperplasia.

Myelolipomas are rare and benign neoplasms, predominant of the adrenal glands, consisting of adipose and mature hematopoietic tissue, commonly discovered incidentally with increased use of radiologic imaging. Few cases of giant bilateral adrenal masses are reported, especially in the setting of congenital adrenal hyperplasia (CAH). We report the case of a 39-year-old male with a history of CAH secondary to 21-α hydroxylase deficiency on steroids since childhood, self-discontinued during adolescence, presenting with abdominal distension, fatigue, decreased libido, and easy bruising. Imaging revealed giant bilateral adrenal masses. He subsequently underwent bilateral adrenalectomy found to be myelolipomas measuring 30 × 25 × 20 cm on the left and weighing 4.1 kg and 25 × 20 × 13 cm on the right and weighing 2.7 kg. Adrenal myelolipomas are found to coexist with many other conditions such as Cushing's syndrome, Addison's disease, and CAH. We discuss the association with high adrenocorticotropic hormone (ACTH) states and review the studies involving ACTH as proponent leading to myelolipomas. Massive growth of these tumors, as in our case, can produce compression and hemorrhagic symptoms. We believe it is possible that self-discontinuation of steroids, in the setting of CAH, may have resulted in the growth of his adrenal masses.

[Preparation of citrulline microspheres by spray drying technique for colonic targeting]. / Préparation des microsphères de citrulline à ciblage colique par la technique de spray drying.

INTRODUCTION: Citrulline is an amino acid that becomes essential in situations of intestinal insufficiency such as short bowel syndrome. It is therefore interesting to provide the patients with dosage forms for routing citrulline to the colon. The aim of this work is to formulate microspheres of citrulline for colonic targeting by the technique of spray drying. MATERIAL AND METHODS: Eudragit(®) FS 30D was selected as polymer to encapsulate citrulline using the spray drying technique. Citrulline and Eudragit(®) FS 30D were dissolved in water and ethanol, respectively. The aqueous and the ethanolic solutions were then mixed in 1:2 (v/v) ratio. Microspheres were obtained by nebulizing the citrulline-Eudragit(®) FS 30D solution using a Mini spray dryer equipped with a 0.7mm nozzle. The microspheres have been formulated using citrulline and Eudragit(®) FS 30D. The size distribution of microspheres was determined by light diffraction. The morphology of the microspheres was studied by electron microscopy. Manufacturing yields, encapsulation rate and dissolution profiles were also studied. RESULTS AND DISCUSSION: The microspheres obtained had a spherical shape with a smooth surface and a homogeneous size except for the microspheres containing the highest concentration of polymer (90 %). The formulation showed that the size and morphology of the microspheres are influenced by the polymer concentration. Manufacturing yields were about 51 % but encapsulation rate were always very high (above 90 %). The in vitro dissolution study showed that the use of the Eudragit(®) FS 30D under these conditions is not appropriate to change the dissolution profile of the citrulline. CONCLUSION: This technique has led to the formulation of microspheres with good physical properties in terms of morphology and size. The compression of the microspheres should help to control citrulline release for colonic targeting.

Morphology, seasonality and phylogeny of Zschokkella soleae sp. n. (Myxozoa, Myxosporea) parasite of Solea solea (L.) (Pleuronectiformes, Soleidae) from Ghar El Melh Lagoon, Tunisia.

A new Myxosporea, Zschokkella soleae sp. n., was found in the gall bladder and the bile of common sole, Solea solea (L.), from Ghar El Melh Lagoon in north-east Tunisia. This is the first record for the presence of Zschokkella species in Tunisian waters. The parasite's plasmodia are polysporic with variable size and shape. Some plasmodia appeared attached to the gall bladder epithelium while others were found free in bile. Mature spores are ellipsoidal in frontal view 13.8±0.38 µm long and 10.86±0.40 µm wide with two equal size spherical polar capsules 3.6±0.43 µm in size. The prevalence of infection seems to correlate with host size and changes over the year with maximum percentage in summer. Based on the 18S rDNA sequence data, Z. soleae sp. n. is readily distinguishable from other myxozoan DNA sequences in GenBank. Phylogenetically, the new species is placed in the freshwater Myxidium clade including several Zschokkella spp. infecting the gall bladder. Morphology, histology as well as DNA sequence analysis indicate that the examined species differs from all previously described Zschokkella species.

[Evaluation of urinary metanephrines for the diagnosis of pheochromocytoma]. / Evaluation du dosage des métanéphrines urinaires dans le diagnostic du phéochromocytome.

OBJECTIVE: evaluate the assay of urinary metanephrines in diagnosis of pheochromocytoma (PH) and determine diagnostic cut-off values. METHODS: this is a retrospective study about 87 patients suspected of pheochromocytoma,whose of 24-h urinary fractionated metanephrine was measured. These cases were collected from Internal Medecine Departments (A and B) at Charles Nicolle's Hospital. Two groups of patients were studied: a pheochromocytoma group (n=33) with a histologically-proven pheochromocytoma and a control group of 54 patients. Receiver Operating Characteristic (ROC) curves were used to determine the best sensitivities and specificities. RESULTS: The analysis of biological parameters showed that means and standard deviation of urinary fractionated metanephrines in pheochromocytoma group were significantly higher than those of control group. Sensitivity and specificity of urinary normetanephrine test (95% and 98.1% respectively) were higher than those of urinary metanephrine and 3-methoxytyramine. A correlation between urinary normetanephrine and tumor size of pheochromocytoma was found. CONCLUSION: Urinary fractionated metanephrines is an efficient biochemical test for the diagnosis of pheochromocytoma.

Aerobic training programs and glycemic control in diabetic children in relation to exercise frequency.

AIM: The aim of this study was to assess the effect of an aerobic training on glycemic control and lipid profile in diabetic children. METHODS: Thirty-three children with type 1 diabetes mellitus (T1DM) were equally divided in three groups. The control group (CG) did not perform any training intervention during the period of the investigation and the subjects were instructed to continue with their daily lifestyle patterns. The second group (G1) and the third group (G2) completed a six-month aerobic training programs. During the period of the investigation, G1 participated in one daily session (~60 min) of aerobic exercise twice weekly, while G2 performed in the form of daily session four times a week (~60 min). HbA1c and lipid profile were measured before training intervention, then after three and six months. RESULTS: The three-month periods was without significant changes of HbA1c in the two groups but significantly increased high-density lipoprotein cholesterol (HDL-C) in G1 (P<0.05). In G2, an increase of HDL-C was accompanied by a decrease of serum triglyceride (TG) (P<0.05). After six months, only HDL-C and TG levels were significantly lower in G1 (P<0.01), while in G2 HDL-C increased (68.8±5.7 mg/dL vs. 56.7 ±7.2 mg/dL; P<0.01), low-density lipoprotein cholesterol (LDL-C) (69.2±8.5 mg/dL vs. 81.6±11.8 mg/dL; P<0.01), TG concentrations decreased (60.7±6.9 mg/dL vs. 77.4±9.3 mg/dL; P<0.01) and HbA1c was significantly lower (6.8±1.1% vs. 8.2±1.5%; P<0.05), comparatively to those before training. CONCLUSION: However, the six-month periods showed that children exercising more than two times weekly significantly improved HbA1c and lipid profile. These results must encourage children with T1DM to regularly practice sporty activities for long periods.

Long-term outcomes with concurrent carboplatin, paclitaxel and radiation therapy for locally advanced, inoperable head and neck cancer.

BACKGROUND: Our goal was to evaluate long-term efficacy outcomes of patients with squamous cell carcinoma of the head and neck (SCCHN) treated with carboplatin, paclitaxel (Taxol) and radiotherapy. PATIENTS AND METHODS: We conducted a phase II trial in inoperable patients with locally advanced SCCHN. Carboplatin 100 mg/m(2) and paclitaxel 40 mg/m(2) were administered i.v. once a week during external beam radiation therapy (180 cGy per fraction) for 6-7 weeks. Interstitial brachytherapy was used as a boost in selected patients with primary malignancies of the oral cavity and the oropharynx. RESULTS: Fifty-five patients were enrolled. Fifty-two patients (95%) had stage IV and 51 (93%) had technically unresectable disease; 62% had an oropharyngeal primary site. Twenty-one patients underwent brachytherapy boost. Grade 3 or 4 mucositis occurred in 30% of patients. One death occurred during treatment that was related to complications of gastrostomy tube placement. Forty of 50 assessable patients (80%) had an objective response, with a complete response rate of 52%. With a median follow-up of 69 months for surviving patients, the 5-year progression-free survival was 36% and the 5-year overall survival was 35%. Two of the 18 long-term survivors of >50 months were gastrostomy tube feeding dependent. Patients undergoing brachytherapy boost (n = 21) had similar outcomes compared with the rest of the patients. In multivariate analysis, baseline hemoglobin levels and N stage were predictive of survival. CONCLUSION: Treatment with concurrent carboplatin, paclitaxel and radiation is safe and offers curative potential for poor prognosis patients with locally advanced SCCHN.

Establishment of multiple sublineages of H5N1 influenza virus in Asia: implications for pandemic control.

Preparedness for a possible influenza pandemic caused by highly pathogenic avian influenza A subtype H5N1 has become a global priority. The spread of the virus to Europe and continued human infection in Southeast Asia have heightened pandemic concern. It remains unknown from where the pandemic strain may emerge; current attention is directed at Vietnam, Thailand, and, more recently, Indonesia and China. Here, we report that genetically and antigenically distinct sublineages of H5N1 virus have become established in poultry in different geographical regions of Southeast Asia, indicating the long-term endemicity of the virus, and the isolation of H5N1 virus from apparently healthy migratory birds in southern China. Our data show that H5N1 influenza virus, has continued to spread from its established source in southern China to other regions through transport of poultry and bird migration. The identification of regionally distinct sublineages contributes to the understanding of the mechanism for the perpetuation and spread of H5N1, providing information that is directly relevant to control of the source of infection in poultry. It points to the necessity of surveillance that is geographically broader than previously supposed and that includes H5N1 viruses of greater genetic and antigenic diversity.

Characterization and mutant analysis of the Drosophila sema 5c gene.

Class V semaphorins are transmembrane glycoproteins characterised by the presence of thrombospondin type I (Tsp) repeats linked to their extracellular semaphorin domain. Sema 5C is the only class V semaphorin found in Drosophila. Dsema 5C RNA is maternally provided and its embryonic expression is prominent in the mesoderm and muscle attachment sites. Here, we show that DSema 5C exists in two protein isoforms as a result of alternative splicing and that both protein and RNA have similar expression patterns. Using a combination of various molecular markers, we show that the DSema 5C protein becomes enriched in mesodermal cells that would normally give rise to fat body and visceral structures. In late embryos, DSema 5C is expressed in segment boundary cells that would constitute subsets of muscle attachment sites. Both RNA and protein are excluded from the somatic precursors and the mature muscles. The expression data suggest DSema 5C localised to the epidermal component of muscle attachment sites. Mutations in Dsema 5C were isolated from a P-element excision screen and by blotting analysis. The Dsema 5C mutants are homozygous viable and show no obvious embryonic phenotypes, suggesting that the maternal and zygotic components of Dsema 5C are not essential for fly development.

[Epidemiologic data in renal lithiasis in adults]. / Données épidémiologiques de la lithiase rénale chez l'adulte.

The morpho-costitutional analysis of 574 urinary lithiasis emitted by tunisean adults permitted to define an épidemiology's profile. This resemble to the épidemiology's profile of under-developed conry: Amore raised frequency of the renal lithiasis at the man than at the woman with a sec ratio of 2.4. An average age of +14 years with a peak to 4th decade in 2 sexes. The upper localitation of the calculi is founded in 94% cases. The fréquency of the relapses, the mode of expulsion and the size of calculi are différent of those published in the litérature. Probably because the time of study which last 4 years is too short, so it don't enable us to find a result like the literature. The surgery is the mode of most fréquent élimination (51%). This s dû to the présence great size calculi in our popûlation and to the récent introduction of the lithotritie in our country.

Interaction with protein phosphatase 1 Is essential for bifocal function during the morphogenesis of the Drosophila compound eye.

The gene bifocal (bif), required for photoreceptor morphogenesis in the Drosophila compound eye, encodes a protein that is shown to interact with protein phosphatase 1 (PP1) using the yeast two-hybrid system. Complex formation between Bif and PP1 is supported by coprecipitation of the two proteins. Residues 992 to 995 (RVQF) in the carboxy-terminal region of Bif, which conform to the consensus PP1-binding motif, are shown to be essential for the interaction of Bif with PP1. The interaction of PP1 with bacterially expressed and endogenous Bif can be disrupted by a synthetic peptide known to block interaction of other regulatory subunits with PP1. Null bif mutants exhibit a rough eye phenotype, disorganized rhabdomeres (light-gathering rhodopsin-rich microvillar membrane structures in the photoreceptor cells) and alterations in the actin cytoskeleton. Expression of wild-type bif transgenes resulted in significant rescue of these abnormalities. In contrast, expression of transgenes encoding the Bif F995A mutant, which disrupts binding to PP1, was unable to rescue any aspect of the bif phenotype. The results indicate that the PP1-Bif interaction is critical for the rescue and that a major function of Bif is to target PP1c to a specific subcellular location. The role of the PP1-Bif complex in modulating the organization of the actin cytoskeleton underlying the rhabdomeres is discussed.

The Drosophila homolog of human AF10/AF17 leukemia fusion genes (Dalf) encodes a zinc finger/leucine zipper nuclear protein required in the nervous system for maintaining EVE expression and normal growth.

Sibling neurons in the embryonic central nervous system (CNS) of Drosophila can adopt distinct states as judged by gene expression and axon projection. In the NB4-2 lineage, two even-skipped (eve)-expressing sibling neuronal cells, RP2 and RP2sib, are formed in each hemineuromere. Throughout embryogenesis, only RP2, but not RP2sib, maintains eve expression. In this report, we describe a P-element induced mutation that alters the expression pattern of EVE in RP2 motoneurons in the Drosophila embryonic CNS. The mutation was mapped to a Drosophila homolog of human AF10/AF17 leukemia fusion genes (alf), and therefore named Dalf. Like its human counterparts, Dalf encodes a zinc finger/leucine zipper nuclear protein that is widely expressed in embryonic and larval tissues including neurons and glia. In Dalf mutant embryos, the RP2 motoneuron no longer maintains EVE expression. The effect of the Dalf mutation on EVE expression is RP2-specific and does not affect other characteristics of the RP2 motoneuron. In addition to the embryonic phenotype, Dalf mutant larvae are retarded in their growth and this defect can be rescued by the ectopic expression of a Dalf transgene under the control of a neuronal GAL4 driver. This indicates a requirement for Dalf function in the nervous system for maintaining gene expression and the facilitation of normal growth.

Receptor tyrosine phosphatases regulate axon guidance across the midline of the Drosophila embryo.

Neural receptor-linked protein tyrosine phosphatases (RPTPs) are required for guidance of motoneuron and photoreceptor growth cones in Drosophila. These phosphatases have not been implicated in growth cone responses to specific guidance cues, however, so it is unknown which aspects of axonal pathfinding are controlled by their activities. Three RPTPs, known as DLAR, DPTP69D, and DPTP99A, have been genetically characterized thus far. Here we report the isolation of mutations in the fourth neural RPTP, DPTP10D. The analysis of double mutant phenotypes shows that DPTP10D and DPTP69D are necessary for repulsion of growth cones from the midline of the embryonic central nervous system. Repulsion is thought to be triggered by binding of the secreted protein Slit, which is expressed by midline glia, to Roundabout (Robo) receptors on growth cones. Robo repulsion is downregulated by the Commissureless (Comm) protein, allowing axons to cross the midline. Here we show that the Rptp mutations genetically interact with robo, slit and comm. The nature of these interactions suggests that DPTP10D and DPTP69D are positive regulators of Slit/Roundabout repulsive signaling. We also show that elimination of all four neural RPTPs converts most noncrossing longitudinal pathways into commissures that cross the midline, indicating that tyrosine phosphorylation controls the manner in which growth cones respond to midline signals.

Lipase activity in germinating sunflower seedlings.

Studying lipase in germinating sunflower seedlings, we looked for an activator of the lipolytic activity. In the presence of 1.25 mM ATP, the enzyme activity increased 2-fold. Lipid-body lipase solubilization was realized using two detergents: Tween 80 and CHAPS. Lipolytic activity was increased 10-fold in the presence of 2% (w/v) CHAPS, showing the probable 'complexity' of the enzyme. Looking for the possible lipolytic activity of the 10000 g pellet we detected the presence of the enzyme. The pellet extract was mixed, in a range of concentrations, with the oil-body fraction. The resulting lipolytic activity was 4-fold higher. These results give clues as to the subcellular distribution of lipase and its intracellular transport.

Results of multifield conformal radiation therapy of nonsmall-cell lung carcinoma using multileaf collimation beams.

A five-field conformal technique with three-dimensional radiation therapy treatment planning (3-DRTP) has been shown to permit better definition of the target volume for lung cancer, while minimizing the normal tissue volume receiving greater than 50% of the target dose. In an initial study to confirm the safety of conventional doses, we used the five-field conformal 3-DRTP technique. We then used the technique in a second study, enhancing the therapeutic index in a series of 42 patients, as well as to evaluate feasibility, survival outcome, and treatment toxicity. Forty-two consecutive patients with nonsmall-cell lung carcinoma (NSCLC) were evaluated during the years 1993-1997. The median age was 60 years (range 34-80). The median radiation therapy (RT) dose to the gross tumor volume was 6,300 cGy (range 5,000-6,840 cGy) delivered over 6 to 6.5 weeks in 180-275 cGy daily fractions, 5 days per week. There were three patients who received a split course treatment of 5,500 cGy in 20 fractions, delivering 275 cGy daily with a 2-week break built into the treatment course after 10 fractions. The stages of disease were II in 2%, IIIA in 40%, IIIB in 42.9%, and recurrent disease in 14.3% of the patients. The mean tumor volume was 324.14 cc (range 88.3-773.7 cc); 57.1% of the patients received combined chemoradiotherapy, while the others were treated with radiation therapy alone. Of the 42 patients, 7 were excluded from the final analysis because of diagnosis of distant metastasis during treatment. Two of the patients had their histology reinterpreted as being other than NSCLC, 2 patients did not complete RT at the time of analysis, and 1 patient voluntarily discontinued treatment because of progressive deterioration. Median follow-up was 11.2 months (range 3-32.5 months). Survival for patients with Stage III disease was 70.2% at 1 year and 51.5% at 2 years, with median survival not yet reached. Local control for the entire series was 23.3+/-11.4% at 2 years. However, for Stage III patients, local control was 50% at 1 year and 30% at 2 years. Patients who received concurrent chemotherapy had significantly improved survival (P = 0.002) and local control (P = 0.004), compared with RT alone. Late esophageal toxicity of > or =Grade 3 occurred in 14.1+/-9.3% of patients (3 of 20) receiving combined chemoradiotherapy, but in none of the 15 patients treated with RT alone. Pulmonary toxicity limited to Grades 1-2 occurred in 6.8% of the patients, and none developed > or =Grade 3 pulmonary toxicity. Patients with locally advanced NSCLC, who commonly have tumor volumes in excess of 200 cc, presenta challenge for adequate dose delivery without significant toxicity. Our five-field conformal 3-DRTP technique, which incorporates treatment planning by dose/volume histogram (DVH) was associated with minimal toxicity and may facilitate dose escalation to the gross tumor.

Epidemiology of Trypanosoma evansi infection in crossbred dairy cattle in Malaysia.

An investigation into the epidemiology of Trypansoma evansi infection in crossbred dairy cattle was conducted for a period of 12 months on a dairy cattle farm in Penninsular Malaysia. The prevalence of parasitaemia was highest in lactating animals (13.4%), followed by those in the dry herd (8.8%), late pregnant animals (8.1%), early pregnant animals (4.7%), calves (0.3%) and heifers (0.2%). The prevalence of antigenaemia was highest in the lactating animals (54.7%), followed by that in dry animals (53.7%), heifers (51.1%), late pregnant animals (47.7%), early pregnant animals (46.5%) and calves (24.2%).

Inhibition of peridural fibrosis after laminectomy using low-dose external beam radiation in a rat model.

OBJECTIVE: Clinical studies have revealed a significant association between the presence of extensive postlumbar discectomy peridural scar formation and the reoccurrence of low back and radicular pain. Low-dose perioperative radiation therapy has been shown to inhibit scar formation. Its effect on peridural fibrosis, however, has not been studied. METHODS: Thirty male Sprague-Dawley rats underwent L5 laminectomies. Ten rats each received a single fraction of 700-cGy external beam radiation to the lumbar spine 24 hours before surgery; 10 rats each received 700 cGy 24 hours after surgery. The remaining 10 rats served as a control group. All of the rats were killed 30 days after surgery. The spines were harvested, and axial histological sections through the laminectomy defect were evaluated. Each specimen was scored for extent, density, and arachnoidal involvement by fibrosis. RESULTS: There was a statistically significant difference between the treatment and control groups regarding the extent of fibrosis along the dura (P < 0.001), the density of fibroblasts (P < 0.005), and the arachnoid involvement (P < 0.01). There was no difference in fibrosis reduction between the groups receiving pre- and postlaminectomy radiation. CONCLUSION: Low-dose external beam radiation therapy administered before or after laminectomy in a rat model significantly decreases the extent, density, and arachnoidal involvement of peridural fibrosis. This technique may improve the outcome of patients who undergo reoperations for recurrent radicular and/or low back pain after successful lumbar discectomy in whom there is a significant amount of peridural fibrosis.