Stability of reconstituted solutions of ceftazidime for injections: an HPLC and CE approach

The stability of aqueous reconstituted ceftazidime injection vials containing ceftazidime pentahydrate blended with anhydrous sodium carbonate was investigated in different storage conditions (4 degrees C and 10 degrees C for 7 days in a refrigerator, 20 and 30 degrees C for 24 h) with validated HPLC and (micellar) CE methods. Stability indicating data were obtained for ceftazidime and two degradation products: pyridine and the delta2-ceftazidime isomer. Other degradation products were also identified (the complementarity of the two used experimental procedures was useful in such exercise) and characterized by their UV spectra and retention times. Stability data (7 days at 4 degrees C in a refrigerator and 18 h at room temperature) resulted in agreements with the manufacturers prescription and point out the need of a strict temperature control of the refrigerator's compartment used to store the reconstituted solution.

Improvement of fetal cell recovery from maternal blood: suitable density gradient for FACS separation

OBJECTIVE

To improve the recovery of fetal nucleated erythrocytes (NRBCs) from maternal blood for noninvasive prenatal genetic diagnosis.

METHODS

Blood samples were obtained from 10 women at 8-22 weeks of gestation. Samples were split and mononuclear cells were isolated using 1.083 and 1.090 g/ml of Percoll solution. Flow sorting with antibody to fetal hemoglobin and fluorescence in situ hybridization (FISH) analysis were used to evaluate the number of fetal cells recovered.

RESULTS

In samples separated with the 1.090 density gradient, the yield of true gamma-hemoglobin-positive cells (median 21.0, range 2.2-303.8) was 1.9 times higher than that in the 1.083 density (median 11.1, range 1.1-87.5), although it took 2. 1-fold longer time to flow sort the gamma-hemoglobin-positive cells. In 7 out of 10 cases, the number of gamma-hemoglobin-positive cells recovered from the 1.090 density gradient was 3 times or greater than that from 1.083 gradient. After FISH analysis, we detected a median of 13.3 (range 2.2-98.8) fetal NRBCs per 10-ml maternal blood in the 1.090 density gradient, whereas a median of 11.0 fetal NRBCs were detected in the 1.083 gradient (range 1.1-35.0). The number of fetal NRBCs in the 1.090 density was significantly higher than that in the 1.083.

CONCLUSION

Increased Percoll density results in improved fetal cell recovery in fresh posttermination maternal samples. The increased yield of fetal cells using this gradient may permit better noninvasive detection of fetal chromosome as well as DNA abnormalities in maternal blood.

Is the new TNM (1997) the best system for predicting prognosis?

In 1997, the U.I.C.C. (International Union against Cancer) modified the previous TNM stage grouping published in 1987. In the present study, TANIS and TNM '97 systems were compared in order to evaluate their prognostic ability. Data from 164 patients affected by primary squamous cell carcinoma cancers of the oral cavity (n=100) and oropharynx (n=64) were analyzed by means of survival analyses. Both systems showed a significant correlation with survival rate. TANIS yielded better results in association with the survival rate as compared with TNM '97.

Sonographic imaging of normal and osteoarthritic cartilage

OBJECTIVES

This study was undertaken to describe representative sonographic features of normal and osteoarthritic cartilage.

METHODS

Sonographic evaluation was performed with real-time ultrasound equipment, using 7.5-, 10-, 13-, 15-, and 20-MHz transducers. Normal and osteoarthritic cartilage has been studied in healthy subjects and in patients with osteoarthritis.

RESULTS

Ultrasonography allows a safe, quick, and careful evaluation of both normal and osteoarthritic cartilage. A spectrum of images ranging from loss of cartilage transparency to marked narrowing of the cartilage layer can be depicted clearly in patients with osteoarthritis. Loss of clarity of the cartilaginous band and loss of the normal sharpness of the synovial space-cartilage interface are the earlier features of cartilage damage.

CONCLUSIONS

Although the value of ultrasonography in the evaluation of articular cartilage remains to be determined, this imaging method can be regarded as a useful bedside procedure for initial diagnostic screening of osteoarthritic femoral condylar cartilage.

Morphologic characteristics of initial lymphatics of the healthy and diseased human gingiva

Investigation was performed on healthy and inflamed human gingivae. In the healthy mucosa lymphatic vessels generally appeared as flattened channels with a reduced lumen. Only in very inflamed tissue were some more evident vessels with a distended wall detectable. Ultrastructurally, most of the vessels had the characteristics of capillaries and they were delimited by a thin and irregular endothelial wall with large intercellular spaces. These observations indicate that in the gingival tissues, which are continuously exposed to inflammatory agents and need a really efficient draining system, the pathway of interstitial exudation and cell migration may include both the lymphatic vessel system and the intercellular spaces of the permeable junctional epithelium.

Down-regulation of cyclin B1 gene transcription in terminally differentiated skeletal muscle cells is associated with loss of functional CCAAT-binding NF-Y complex

The observation that cyclin B1 protein and mRNAs are down-regulated in terminally differentiated (TD) C2C12 cells, suggested us to investigate the transcriptional regulation of the cyclin B1 gene in these cells. Transfections of cyclin B1 promoter constructs indicate that two CCAAT boxes support cyclin B1 promoter activity in proliferating cells. EMSAs demonstrate that both CCAAT boxes are recognized by the trimeric NF-Y complex in proliferating but not in TD cells. Transfecting a dominant-negative mutant of NF-YA we provide evidence that NF-Y is required for maximal promoter activity. Addition of recombinant NF-YA to TD C2C12 nuclear extracts restores binding activity in vitro, thus indicating that the loss of NF-YA in TD cells is responsible for the lack of the NF-Y binding to the CCAAT boxes. Consistent with this, we found that the NF-YA protein is absent in TD C2C12 cells. In conclusion, our data demonstrate that NF-Y is required for cyclin B1 promoter activity. We also demonstrate that cyclin B1 expression is regulated at the transcriptional level in TD C2C12 cells and that the switch-off of cyclin B1 promoter activity in differentiated cells depends upon the loss of a functional NF-Y complex. In particular the loss of NF-YA protein is most likely responsible for its inactivation.

Fetal cell identifiers: results of microscope slide-based immunocytochemical studies as a function of gestational age and abnormality

OBJECTIVE

We evaluated monoclonal antibodies to 3 cell surface and 3 intracellular antigens for their relative usefulness as markers to identify fetal cells in maternal blood.

STUDY DESIGN

With indirect immunocytochemical labeling techniques, antigen expression was studied in 52 fetal blood samples as a function of gestational age, fetal karyotype, the presence of multiple anomalies detectable on ultrasonography, and anemia.

RESULTS

A decline in the expression of these antigens as gestational age advanced was demonstrated. Samples from karyotypically abnormal fetuses, fetuses with multiple anomalies, and anemic fetuses showed an antigenic distribution that was immature for gestational age. In normal fetuses zeta globin and epsilon globin expression decreased after 12 to 14 weeks, potentially limiting the utility of these proteins as fetal cell markers in the isolation of fetal cells from maternal blood.

CONCLUSIONS

The results of this study demonstrate a fetal developmental hematologic profile that varies with gestational age and also with pathologic condition. Antibodies to the gamma chain of fetal hemoglobin and the transferrin receptor (CD71) are the most useful fetal cell-identifying reagents.

Stage grouping reliability: TNM '97 versus TANIS in laryngeal cancer

PURPOSE

To compare the correlation of TANIS and TNM '97 with the survival rate in laryngeal cancer.

METHODS AND MATERIAL

From 1970 to 1990, 599 patients at the ENT Clinic, University of Ferrara, had a complete follow-up and met the criteria of enrollment. Data were analyzed by means of survival analyses (Kaplan-Meler and Cox algorithms).

RESULTS

Both systems showed a significant correlation with the survival rate. TANIS advanced subcategories were better correlated with the mortality rate than TNM stages IVa and IVb. Again, in the final statistical model, TANIS was more highly correlated with survival rate than TNM.

Stage grouping of oropharyngeal cancer: evaluation of three systems by means of survival analysis

Stage grouping is a method of summarizing multiple categories generated from the tumor, node, metastasis (TNM) classification system. Recently three different systems, the T and N integer score (TANIS), Hart, and 1997 Union Internationale Contre le Cancer systems, have been proposed. To verify their correlation to survival, a series of 64 patients affected by primary squamous cell carcinoma of the oropharynx was considered in this retrospective study. The data set was classified according to Union Internationale Contre le Cancer T stage and then grouped as recommended by the three systems. Results showed a crude survival rate of 28.13%. Univariate analysis by means of the logrank test yielded significant P values for the T and N integer score and Hart systems (0.0452 and 0.0179, respectively) and a borderline P value (0.0728) for the stratification based on the 1997 Union Internationale Contre le Cancer system. Multivariate analysis (Cox regression adjusted for age and sex) showed a significant correlation between the three staging systems and the mortality rate. Odds ratios were 1.36 (95% confidence interval, 1.12-1.66), 1.58 (95% confidence interval, 1.18-2.12), and 1.63 (95% confidence interval, 1.08-2.48) for the T and N integer score, Hart, and 1997 Union Internationale Contre le Cancer systems, respectively. The T and N integer score system showed the best statistical correlation, but a conclusive result could not be achieved because of the low number of patients in this study.

Extension as a prognostic factor in oropharyngeal cancer: largest mucosal dimension compared with number of (sub)sites involved

We report a retrospective study of 64 patients with primary squamous cell carcinoma of the oropharynx. The tumours were classified by the UICC (Union Internationale Contre le Cancer) system and a New Tumour Staging (NTS) system. Results showed a crude survival of 29% at 5 years. The most important prognostic factor for survival rate was the tumour (T) stage in both classifications. NTS recommendations that consider the number of sites and subsites involved yield a better correlation between survival and T stage. NTS also discriminates better between the T stages than the UICC criteria.

Neonatal neutrophil activation is a function of labor length in preterm infants

To understand better the development of the neonatal immune system, we evaluated the role of labor length, gestational age, and mode of delivery on the expression of the neonatal neutrophil cell surface antigens CD11b, CD11c, CD15, CD33, and CD66b in premature newborns. Peripheral blood samples from 68 apparently healthy preterm infants were obtained within 12 h of birth and incubated with MAb to the CD antigens. Samples were lysed, fixed, and analyzed by flow cytometry. Multivariate analysis was used to study the simultaneous effect of the labor length and gestational age on the neonatal neutrophil cell surface antigen expression. A positive correlation was demonstrated between neutrophil antigen expression and labor length (p < 0.001-0.026) but not with the mode of delivery (p = 0.191-0.638). There was no significant correlation between expression of neutrophil antigens and gestational age at delivery (p = 0.057-0.866), except for CD15 (p = 0.010). Our results indicate labor length is a significant factor in neonatal neutrophil activation at birth. These findings are independent of gestational age in preterm newborns. Mode of delivery does not seem to influence neonatal neutrophil activation. The neutrophils of premature infants can be activated antenatally and/or during labor.

Human alpha1-glycoprotein acid as chiral selector in the enantioseparation of midodrine and deglymidodrine racemates by HPLC

Human alpha1-acid glycoprotein (alpha1-AGP) has been used as a chiral stationary phase (CSP) for the enantioseparation of midodrine and deglymidodrine racemates in the same HPLC run. The imobilized AGP resulted as the best chiral selector for the enantioresolution of two compounds. Due to the modification of alpha1-AGP characters as a result of changing the composition of the mobile phase, an attempt study of the watery mobile phase (ionic strength and pH of the buffer, nature and concentration of the organic modifier) allowed for an increase in the enantioselectivity of the chromatographic system and an optimization of the resolution base-line of both enantiomeric pairs.

Analysis of ceftazidime and related compounds by micellar electrokinetic chromatography

A micellar electrokinetic chromatographic method for the separation and quantification of ceftazidime, its delta2-isomer and pyridine (two ceftazidime related impurities) was developed and validated. Optimised conditions were obtained using an electrolyte system consisting of 25 mM sodium tetraborate, at pH 9.2, and 75 mM sodium dodecylsulphate. A limit of detection of 0.2 microg ml(-1) and a limit of quantitation of 0.6 microg ml(-1) were estimated for pyridine and delta2-isomer: this means that levels of < 0.1% of pyridine and delta2-isomer in ceftazidime can be determined. Calibration curves for all analytes were linear over the studied ranges with correlation coefficients >0.999. Good reproducibility for migration times and corrected peak areas were achieved (RSD % 0.3 and 1.0, respectively). The results demonstrate that the method is reproducible, accurate and appropriate for ceftazidime assay in pharmaceutical samples.

A comparison between TNM and TANIS stage grouping for predicting prognosis of oral and oropharyngeal cancer

PURPOSE

The 1987 TNM classification system modified some T and N definition but it did not change stage grouping. Consequently it has not improved the prognostic validity of the advanced stage groups. In 1993, a new stage grouping was purposed, TANIS, that seems to have a higher correlation with survival. In this report, the TNM classification and TANIS system were compared to evaluate this prognostic ability.

PATIENTS AND METHODS

Data from 164 patients affected by primary cancers of oropharynx or oral cavity were analyzed by means of Kaplan-Meier and Cox regression analysis.

RESULTS

The crude survival rate at 5 years was 43.9%. Both systems showed a significant correlation with the survival rate by means of Cox regression analysis. TANIS subcategories were correlated to the mortality rate in the stage IV patients. TANIS resulted a better predictor of mortality when compared with TNM.

CONCLUSION

The TANIS system was able to separate the TNM stage IV patients into prognostic groups, yielding more information with respect to TNM for such a category of patients. When a comparison between TNM and TANIS was performed, it was observed that TANIS had a higher correlation with survival rate, whereas TNM did not add any information in defining the survival function.

Should we treat minor degrees of glucose intolerance in pregnancy?

We examined the pregnancy outcome of 112 women classified as minor degrees of glucose intolerance (MDGI) in pregnancy in a screening program based on Carpenter and Coustan's criteria. The MDGI group comprised 49 women with abnormal oral glucose challenge test (OGCT) followed by normal OGTT (group A), and 63 with "borderline" OGTT (1 abnormal value, group B). No treatment was offered to 88 MDGI women, while 26 received dietary advice and metabolic monitoring. A control group was constituted from 112 age- and BMI-matched negative screenees. Similar rates of cesarean sections and macrosomia, but higher rate of large for gestational age (LGA) babies (25.9% vs 14.3%) were found in MDGI, without difference between groups A and B. When comparing treated and untreated MDGI, lower LGA incidence (11.5% vs 30.2%) and no macrosomia were found in the former. In conclusion, untreated MDGI may present excessive fetal growth, which can be normalized by dietary treatment and metabolic monitoring.