Preparation of chemically stable allergen‐specific sublingual immunotherapy from Egyptian allergens

BackgroundThe term “allergen extracts” refers to solutions of proteins or glycoproteins extracted from source raw materials.ObjectivesThis study was planned to prepare chemically stable sublingual immunotherapy from different allergens in Egypt.MethodsAllergen extraction from raw materials. The concentrated aqueous extract of each allergen was mixed with an equal volume of glycerol. The protein content of the preparations was determined using the modified Lowry assay method. The prepared allergens were stored for 9 months at 2–4°C. Samples were analyzed periodically (0, 3, 6, and 9 months of intervals) adopting the Lowry Assay method. Levels of specific IgE to Chenopodium album antigens were measured in patients’ sera by ELISA.ResultsThe concentration of all prepared allergens, as indicated by the concentration of the protein content, was found to decrease exponentially with time, implying first‐order kinetics of degradation. From the values of the slopes of the log plot for each allergen, the half‐life time (t _1/2) and (t _1/4) values were calculated. The expiration date was considered as the time after which the allergen loses 25% of its potency. The obtained values of t _1/4% vary according to the type of vaccine. The most stable one is that of Chenopodium album pollens (2.4 years) and the least stable is that of house dust Mites (9 months). The immunological characters of Chenopodium album extract were stable for at least 6 months.ConclusionDifferences exist among allergen extracts made by multiple manufacturers. So, developments in studies on allergen preparation and characterization in a different locality are necessary.     

Isoform-specific role of transforming growth factor-beta2 in the regulation of proliferation and differentiation of murine adrenal chromaffin cells in vivo

Chromaffin cells, the neuroendocrine cells of the adrenal medulla, play an important role in molecular, cellular, and developmental neurobiology. Unlike the closely related sympathetic neurons, chromaffin cells are able to proliferate throughout their whole life span. Proliferation of chromaffin cells in vivo is thought to be regulated by the interaction of neurogenic and hormonal signals. Previous studies have shown that chromaffin cells synthesize and release transforming growth factor-betas (TGF-betas). In the present study, effects of TGF-betas on proliferation and differentiation of chromaffin cells in mouse adrenal chromaffin cells were investigated in a genetic mouse model. We observed a significant increase in the total number of tyrosine hydroxylase-positive (TH(+)) cells in Tgfbeta2(-/-) knockout mouse embryos at embryonic day (E) 18.5 compared with wild-type animals (Tgfbeta2(+/+)), but no changes in the number of TH(+) cells were observed in Tgfbeta3(-/-) mouse mutants. At E15.5, but not at E18.5, there was a marked increase in the number of proliferative cell nuclear antigen-positive chromaffin cells in Tgfbeta2(-/-) knockout embryos compared with the wild-type group. On the other hand, there was a clear decrease in the ratio of total number of phenylethanolamine-N-methyltransferase-positive cells to the total TH(+) in Tgfbeta2(-/-) mice embryos at E18.5 compared with wild-type animals. This is the first documentation of the physiological significance of the TGF-beta2, an isoform that has been suggested to play a role in the regulation of chromaffin cells proliferation and differentiation based on in vitro experiments.     

Induction of protective immunity by DNA vaccination with Toxoplasma gondii HSP70, HSP30 and SAG1 genes

The vaccination with Toxoplasma gondii heat shock protein 70 (T.g.HSP70) gene (a virulent tachyzoite-specific) induced the most prominent reduction in T. gondii loads in various organs of B6 and BALB/c mice at the acute and chronic phases of toxoplasmosis compared with T.g.HSP30 (a bradyzoite-specific) and SAG1 (a tachyzoite-specific) genes. A single gene gun vaccination with 2 microg of T.g.HSP70 gene induced a significant reduction in the number of T. gondii organisms compared with 50 microg of T.g.HSP70 gene vaccination by intramuscular (i.m.) or intraperitoneal (i.p.) injection. The vaccine effects of T.g.HSP70 gene persisted for more than 3 months.     

Spectrofluorometric determination of nimodipine in dosage forms and human urine

A simple sensitive and specific spectrofluorometric method was developed for the determination of nimodipine (NDP) in pharmaceutical preparations and human urine. The method is based on reduction of nimodipine with Zn/HCl and measuring the obtained fluorescence at 425 nm after excitation at 360 nm. The factors affecting the development of the fluorophore and its stability were studied and optimized. The effect of some surfactants such as beta-cyclodextrin (betaCD), carboxymethylcelullose (CMC), sodium dodecyl sulphate (SDS) and Triton X-100, on the fluorescence intensity was studied. The fluorescence intensity-concentration plot is rectilinear over the range 0.1-5.0 microg/ml in presence of Triton X-100 with a minimum detectability limit of 0.06 microg/ml (1.62 x 10(-7) M). The proposed method was successfully applied to commercial tablets containing NDP, the percentage recovery agreed well with those obtained using the official methods. The method was further extended to the in vitro determination of NDP in spiked human urine samples. The % recovery was 102.1 +/- 2.54 (n = 4). A proposal of the reduction reaction pathway was postulated.     

Spectrophotometric determination of tolbutamide, thiamine hydrochloride, and pyridoxine hydrochloride in combination products.

The first derivative curve is used for tolbutamide determination in unit-dose tablets and in combination products. The absorbance contribution from tablet excipient and coexisting components, thiamine and pyridoxine, is thereby nullified. The interference from tolbutamide during thiamine and pyridoxine determination is eliminated by solvent extraction and pH-induced differential spectrophotometry. Thiamine is measured at the isosbestic point of pyridoxine. The latter is determined by the differential absorbance measurement at two wavelengths with the consequent computation of the delta absorbance value.     

Malignant fibrous histiocytoma: a retrospective study of 109 cases

The purpose of this report is to assess the prognostic factors that could influence management and clinical outcome of malignant fibrous histiocytoma (MFH) of soft tissues. Between 1975 and 1998, 109 patients diagnosed with MFH of the soft tissues, seen at King Faisal Specialist Hospital and Research Center, have been reviewed. Of the 109 patients, 75 were men and 34 were women. The median age at presentation was 48 years (range: 3-94). Seven patients (6%) had regional nodal disease and 10 other patients (9%) with distant metastases were excluded from survival analysis. The remaining 92 patients had localized disease and had surgery as the primary treatment modality with or without radiotherapy and/or chemotherapy. Extremities were the most common location (58%). Tumors less than 5 cm represented 32%, whereas 68% had tumors 5 cm or more. Low-grade tumors constituted 46%, and the remaining 54% were high grade. Thirty-seven percent of patients had positive surgical margins histologically after complete gross resection. The 5- and 10-year relapse-free survival (RFS) rates were 39% and 36%, respectively. Isolated local recurrence occurred in 20 patients (22%), isolated metastatic disease without local recurrence in 9 patients (10%), and combined local and metastatic disease occurred in 20 patients (22%). The overall 5- and 10-year overall survival (OS) rates were 50% and 43%, respectively. On multivariate analysis, tumor size and radiation dose were significant factors for RFS (p = 0.04 and 0.0005, respectively). In terms of OS, size, histologic grade, and surgical margins were significant factors on multivariate analysis (p = 0.001. 0.006, and 0.0001, respectively). Complete surgical resection at the time of primary tumor presentation is likely to afford the best chance for RFS and OS. Radiation therapy plays an important role, in combination with surgery for better local control, particularly in high-grade lesions, and in cases with positive surgical margins after wide complete gross excision. The role of adjuvant chemotherapy remains investigational.     

A five-year analysis of the incidence of glomerulonephritis at Cairo University Hospital-Egypt

Our study aimed to obtain a comprehensive review of the incidence of biopsy-proven glomerulonephritis (GN) at the Cairo University Hospitals, Egypt, over the last five years. We analyzed the clinical and pathological data of all renal biopsy samples that were performed during the period from July 2003 to July 2008. Renal biopsy samples of 924 patients were referred for pathological assessment during the period of the study [437 male and 487 female patients; their mean age was 26.5 ± 14.6 years (range: 2.5-71 years)]. Focal segmental glomerulo-nephritis was the most frequent cause of primary GN (21.21%), followed by mesangial proliferative GN (18.93%), diffuse proliferative GN (13.96%), focal proliferative GN (12.77%) and membranous GN (10.93%). The results could be explained by the high incidence of lupus nephritis among the study subjects as well as the relatively young age of the study group.     

Assessment of initial vancomycin dosing in neonates

BACKGROUND:

Vancomycin is recommended for optimal treatment of late-onset sepsis caused by coagulase-negative Staphylococcus in neonates.

OBJECTIVES:

To assess the performance of an empirical vancomycin dosing regimen in achieving target trough levels, and to revise this regimen if needed.

METHODS:

Data regarding doses and levels were collected and pharmacokinetic parameters were calculated, where possible, for neonates receiving vancomcyin in a neonatal intensive care unit. The primary measure was the percentage of neonates with initial prevancomycin levels of <10 mg/L, 10 mg/L to 20 mg/L and >20 mg/L. Secondary measures included the percentage of neonates with extrapolated trough levels in these ranges, total daily doses that achieved target levels (10 mg/L to 20 mg/L) and total daily doses/dosing intervals that were pharmacokinetically predicted to achieve trough levels of 15 mg/L.

RESULTS:

Of 153 infants started on the empirical regimen (15 mg/kg/day to 45 mg/kg/day, depending on postnatal age and weight), 34.2% initially achieved target trough levels (mean 8.7 mg/L). Analysis of actual doses and pharmacokinetically predicted doses required to reach target levels suggested increasing the empirical dosing for all neonatal age groups. The revised regimen used in the present study (20 mg/kg/day to 40 mg/kg/day, depending on postmenstrual age and postnatal age) was predicted to result in 72% of infants achieving initial target trough levels (mean 15.4 mg/L).

CONCLUSIONS:

A revised empirical vancomycin dosage regimen for neonates was required based on poor achievement of target trough levels (10 mg/L to 20 mg/L) using the previous regimen. The modified regimen is predicted to reach target trough levels more often and increase the mean initial trough levels achieved. This regimen requires clinical validation in an independent cohort in the future.