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Biomedical subjects

K Bouzouita

Publications and source records attributed to K Bouzouita.

At least 19 recordsLinked to original sources

[NK/T-Cell lymphoma of nasopharynx].

OBJECTIVE: Discussion of the clinical and paraclinical features of a rare tumor in the nasopharynx, the NK/T-cell lymphoma, with an emphasis on the implications of Epstein Barr Virus (EBV) in its pathogenesis and prognosis. CASES REPORT: We report the cases of a woman and a man aged 34 and 48, respectively. Clinical presentation was non-specific and diagnosis was established with deep biopsies under general anesthesia. Immunochemistry and in situ hybridization were positive for Epstein Barr virus in tumor cells in both cases. The patients were first treated with chemotherapy (CHOP regimen), then underwent radiotherapy. The first patient achieved complete response at twenty months follow-up. The second patient presented two recurrences which were treated by chemotherapy. He died from acute renal failure during treatment of the second recurrence. CONCLUSION: Diagnosis of NK/T-cell lymphoma may be delayed in the event of non-specific symptoms. Deep biopsies outside necrotic tissue must be obtained. Search for EBV is important as its presence is a factor of poor prognosis.

Adult↗

Stability indicating LC method for the determination of pipamperone.

A high performance liquid chromatographic method for the determination of pipamperone in the presence of one related impurity and its degradation products is described. The method is based on the use of an amide functionalized bonded phase column (LC-ABZ+ Plus) and a mobile phase of acetonitrile-tetrahydrofuran-sodium phosphate monobasic (0.05 M, pH 6.5) (16:11:73, v/v/v). All peaks are eluted in <8 min. The method was demonstrated to be precise, accurate and specific. Degradation study showed that the drug is stable in acidic medium while it degrades under basic and oxidative conditions. The results indicated that the proposed method could be used in a stability assay.

Antipsychotic Agents↗

[Mycobacterial cervical lymphadenitis: role of surgery].

OBJECTIVE: To discuss the place of surgery in the management of mycobacterial cervical lymphadenitis. PATIENTS AND METHODS: It's a retrospective study (1982-2002) about 246 patients treated in the ENT department of Farhat Hached Sousse for cervical lymph node tuberculosis. Resolution was considered when neither symptoms nor lymphadenopathy in examination were noted. RESULTS: The mean age of our patients was 28 years. A light female prevalence was noted. In 5 patients diagnosis was established by lymph node punction. A medical treatment of first intention was then managed with a failure in 3 cases, after deadlines from 3 to 4 months. All other patients were operated: cellulolymphadenectomy (47%), adenectomy (47%) or drainage of a cervical abscess (4%). Recurrence and antituberculosis treatment resistance were noted respectively in 6% and 3% of cases. DISCUSSION: Two questions are still discussed in the management of mycobacterial cervical lymphadenitis: 1- Is surgery necessary for the diagnosis? 2- When is surgery indicated directly? Histological specimen established the diagnosis in all cases and excluded a mestastatic lymph node. In some situations surgery must be indicated at first: cold abscess, lymph node fistulation. CONCLUSION: Surgery still has an important place in the treatment of tuberculosis lymphadenopathy.

Adolescent↗

RP-HPLC and NMR study of cis-trans isomerization of enalaprilat.

The angiotensin converting enzyme inhibitor, enalaprilat can exist in solution as cis and trans conformers which interconvert around the amide bond at room temperature. A HPLC with UV detection was performed to study the influence of various chromatographic operational conditions on both rotamers separation and elution of enalaprilat as a single peak. In addition nuclear overhauser enhancement difference was used for the identification of the conformers. The isomer ratio integrated from the obtained 1H NMR result were 71.5:28.5 and 76:24 at 298 and 279 K, respectively where the trans was the major form.

Chromatography, High Pressure Liquid↗

Reversed-phase liquid chromatography of lisinopril conformers.

The effect of flow rate, temperature, pH, organic solvent and counter ion on peak shape and separation of the cis and trans conformers of lisinopril are investigated by HPLC. It was demonstrated that complete separation of the two isomers can be achieved at low temperature at either neutral or low pH together with appropriate type and concentration of organic solvent, whereas the elution of lisinopril as a single peak is favored by a decrease of flow rate, elevated temperature, choice of organic solvent (type and amount) and the use of an appropriate counter ion concentration.

Chromatography, Liquid↗

Determination and degradation study of haloperidol by high performance liquid chromatography.

A specific, high performance liquid chromatographic method was developed for the assay of haloperidol, together with an adequate separation of its degradation products. The method is based on the use of an octadecylsilane stationary phase column under isocratic conditions. The mobile phase consisted of 50 mM sodium phosphate monobasic pH 2.5-acetonitrile-THF-TEA (63:34:3:0.1, v/v/v/v) adjusted with o-phosphoric acid to a pH of 2.5. The degradation was performed in hydrochloric acid, sodium hydroxide and hydrogen peroxide. The main degradation products were identified. Application of the assay of haloperidol in tablet formulations is presented.

Antipsychotic Agents↗

Derivative spectrophotometric determination of droperidol in presence of parabens.

We have developed a fast and accurate method for the determination of droperidol in the presence of methylparaben and propylparaben using derivative spectrophotometry. The first derivative amplitudes at 255.2 nm were selected for the assay. Calibration graph follows Beer's law in the range of 5-35 microg ml(-1). The coefficient of variation (CV) for intra-day and inter-day precision were less than 1.0 and 2.0%, respectively. The method was applied in the quality control of commercial oral and injection solutions and proved to be suitable for routine analysis.

Chromatography, High Pressure Liquid↗

LC determination and degradation study of droperidol.

A specific, high performance liquid chromatographic method for the determination of droperidol in the presence of its degradation products is described. The method is based on the use of an amide functionalized bonded phase column (LC-ABZ(+) Plus) and a simple mobile phase of methanol-sodium phosphate monobasic (0.05 M, pH 4.5) (40:60, v/v). It enables the resolution of eight compounds from the parent drug and from each other. The degradation was carried out in hydrochloric acid, sodium hydroxide and hydrogen peroxide. The main degradation products were identified. Application of the assay for a commercial preparation of droperidol for injection is presented.

Calibration↗

[Submandibular lithiasis. Report of 48 cases].

This retrospective study concerned 48 patients treated surgically for sub mandibular lithiasis. Results of medical imaging (plain films, sialography, ultrasonography) are confronted with operative findings. The surgical indications are analysed according to lithiasis localisation.

Adult↗

Study of the cis-trans isomerization of enalapril by reversed-phase liquid chromatography.

Enalapril is a dipeptidic angiotensin converting enzyme inhibitor. It exists as a mixture of two conformers in solution with respect to the peptide bond involving the proline amino group. The RPLC of such products may yield peak splitting or multiple peaks as a result of the slow kinetics of the conformation change. In this study, the influence of the flow-rate, pH, temperature, organic modifier and counter ion on the peak shape and the separation of the cis and trans conformers are examined qualitatively by HPLC. It appears that decrease of relaxation time for isomerization with concomitant improvement in peak shape is favoured by a decrease in pH and flow-rate, increase of temperature, choice of organic solvent (nature, amount) and cationic counter ion concentration in the mobile phase. The elution order of the isomers was dependent on the nature of the organic modifier whereas the separation selectivity was improved by an increase of pH or the addition of a negatively charged counter ion. In addition, an NMR investigation on enalapril is described.

Chromatography, High Pressure Liquid↗

[Gougerot-Sjögren syndrome disclosed by MALT lymphoma of the salivary glands. Report of 3 cases].

Sjögren's syndrome is characterized by an increased risk of developing non-Hodgkin's lymphoma. The lymphoma is most frequently extra-nodal, preferentially affecting the salivary gland: low-grade MALT lymphoma. Conversely, underlying Sjögren's syndrome has been recently identified by some authors in patients with non-Hodgkin's lymphoma. In the present report, we present three cases of Sjögren's syndrome disclosed by low-grade salivary gland MALT lymphoma. The patients were all women aged 33, 38 and 52 years. Extension work-up revealed nodal and bone marrow involvement in one case and no evidence of disseminated disease in the two others. Using the European criteria, all of our patients had certain Sjögren's syndrome. Labial salivary gland biopsy and immunopathological studies in newly diagnosed low-grade MALT lymphoma would be helpful in identifying the real frequency of this association.

Adult↗

Zero-crossing derivative spectrophotometry for the determination of haloperidol in presence of parabens.

First derivative spectrophotometry with a zero-crossing technique of measurement is used for the quantitative determination of haloperidol in the presence of methylparaben and propylparaben, which is added as antimicrobial preservatives in pharmaceuticals. This technique permits the quantification of haloperidol in the presence of parabens, with closely overlapping spectral bands, and without any separation step. Linear calibration graphs of first derivative values (at 255.2 nm for haloperidol) versus concentration (in the range 4.0-20.0 micrograms ml-1) were obtained with negligible intercepts. Relative standard deviation of 0.83% was obtained for intra-day precision and 1.86% for inter-day precision. The recovery of haloperidol in synthetic mixtures with parabens and pharmaceutical dosage forms is also reported.

Calibration↗

[Dose-effect of adrenaline nebulization in asthma: comparative study with salbutamol].

UNLABELLED: The aim of this randomized cross-over trial was to evaluate the dose effect and systemic absorption of epinephrine nebulized at 2 and 5 mg in comparison with salbutamol (5 mg). Thirteen asthmatic patients (29 +/- 15 years, 4 men and 9 women) were randomly assigned to receive one nebulization of each of the three treatment regimens at 24 h interval. The evaluation concerned forced expiratory volume in 1 second (FEV1), heart rate, respiratory rate and arterial pressure. All measurements were done at baseline, every 15 minutes during the first hour, and hourly thereafter until return to baseline FEV1. Serum potassium was measured at baseline (T0) and sixty minutes after (T60). Plasma levels of epinephrine were measured at T0, T20, T60. Fifteen minutes after the beginning of nebulization FEV1 improved significantly over baseline in the three groups. These changes were similar in the three groups until T45, while FEV1 improvement was significantly greater in A5 and S groups than A2 group (+640 +/- 470 ml, +721 +/- 349 ml, +406 +/- 306 ml in A5, S and A2 groups respectively, p < 0.01). Bronchodilation lasted significantly longer with salbutamol than with epinephrine (p < 0.05). No side effects were recorded in spite of substantial and dose-dependent systemic absorption of epinephrine. CONCLUSION: Increasing epinephrine doses produces greater bronchodilation without additional side effects. However this bronchodilation lasts shorter than with salbutamol.

Administration, Inhalation↗

Modulation of cisplatin chronotoxicity related to reduced glutathione in mice.

Intracellular reduced glutathione (GSH) concentrations were measured according to the tissue sampling-time along the 24 h scale in male B6D2F1 mice. A significant circadian rhythm in GSH content was statistically validated in liver, jejunum, colon and bone-marrow (P < or = 0.02) but not in kidney. Tissue GSH concentration increased in the dark-activity span and decreased in the light-rest span of mice. The minimum and maximum of tissue GSH content corresponded respectively to the maximum and minimum of cisplatin (CDDP) toxicity. The role of GSH rhythms with regard to CDDP toxicity was investigated, using a specific inhibitor of GSH biosynthesis, buthionine sulfoximine (BSO). Its effects were assessed on both tissue GSH levels and CDDP toxicity at three circadian times. BSO resulted in a 10-fold decrease of the 24 h-mean GSH in kidney. However a moderate GSH decrease characterized liver (-23%) and jejunum (-30%). BSO pretreatment largely enhanced CDDP toxicity which varied according to a circadian rhythm. Although BSO partly and/or totally abolished the tissue GSH rhythms, it did not modify those in CDDP toxicity. We conclude that GSH have an important influence on CDDP toxicity but not in the circadian mechanism of such platinum chronotoxicity.

Animals↗

Comparative pharmacokinetics of oxaliplatin (L-OHP) and carboplatin (CBDCA) in mice with reference to circadian dosing time.

Carboplatin (CBDCA) and oxaliplatin (I-OHP) are non-nephrotoxic platinum (Pt) compounds, which exert their main respective toxicities on the bone marrow and on the intestinal mucosa in mice. Plasma and red blood cell (RBC) drug dispositions were investigated in 324 male B6D2F1 mice after a single IV injection of CBDCA (72 mg kg-1) or I-OHP (17 mg kg-1). Since the toxicities of either drug largely depended upon circadian dosing time, such a pharmacokinetic study was performed following injection of either Pt complex at a time of low (16 h after light onset-HALO), intermediate (0 HALO) or high (8 HALO) toxicity. Pt concentrations in plasma ultrafiltrate (PUF) and in total plasma declined in parallel and became barely detectable by 2 h following CBDCA injection. Conversely, free Pt became undetectable 1 h after I-OHP injection, whereas sustained levels of total Pt were found 24 h post dosing. This suggested that I-OHP had a high binding affinity for plasma proteins. Mean values of t1/2 alpha and mean residence time (MRT) of free Pt for I-OHP (6.7 min and 9.7 min respectively) were half those of CBDCA (12.5 min and 18.1 min respectively). The two drugs had a similar initial volume of distribution (Vdi) of free Pt (10.5 mL) in mice. However, plasma clearance of I-OHP was twice as high (1.06 mL min-1) as that of CBDCA (0.58 mL min-1). Free Pt AUCs were eight to ten times lower for I-OHP than for CBDCA. In contrast, erythrocyte Pt AUCs were three to four times as high for I-OHP as for CBDCA. Circadian changes in pharmacokinetic parameters were large, yet limited to the initial distribution phase (C0, t1/2 alpha, Vdi) as well as mean residence time. The smallest Vdi and the fastest plasma elimination occurred when either drug was injected at 0 HALO. The largest Vdi and the longest elimination were however observed at 8 HALO for CBDCA and 16 HALO for I-OHP. No consistent relationship was found for both Pt complexes with regard to circadian changes in blood pharmacokinetics and in target organ toxicities. The major pharmacokinetics differences between CBDCA and I-OHP were related to both protein binding and RBC handling.

Animals↗

[Tuberculosis of the upper digestive and respiratory tract].

Based on seventeen cases of upper digestive and respiratory tract tuberculosis, the authors review the different localizations of the disease. The mean age of the patients is 34 years old. The diagnostic is based on bacteriological and especially histological examination. The prognostic of the affection is excellent if tuberculosis chemotherapy is used for a minimum of 9 months.

Adult↗

[Malignant external otitis in diabetics].

The authors refer to 10 cases of malignant external otitis in diabetic patients. A group of five patients had a chirurgical treatment associated to an antibiotic therapy. The five other patients were treated medically. The prognosis of this disease is severe.

Aged↗