Analysis of diltiazem and its related substances by HPLC and HPLC/MS.

Diltiazem (DTZ) is an optically active calcium channel blocker having a benzodiazepine structure. The drug used in therapy is (+)-cis-diltiazem with configuration (2S,3S). To describe the analytical profile of DTZ different stationary phases (RP-18, RP-8, monolithic support) were tested.

Urea host monomers for stoichiometric molecular imprinting of oxyanions.

A series of urea-based vinyl monomers was synthesized and investigated for their ability to function as polymerizable hosts for the molecular imprinting of N-Z-D- or L-glutamic acid in polar media (DMSO or DMF). The monomers were synthesized in one step from a polymerizable isocyanate and a nonpolymerizable amine or vice versa, with yields typically over 70%. Prior to polymerization their solution binding properties vis-a-vis tetrabutylammonium benzoate in DMSO were investigated by 1H NMR, UV-vis and fluorescence monitored titrations.

Primary epithelial lung malignancies in the pediatric population.

Background: Primary epithelial lung malignancies are rare in childhood and adolescence. We reviewed the Memorial Sloan-Kettering Cancer Center experience with these tumors to better understand their histology, time to diagnosis, treatment, and outcome.

Procedure: A retrospective review was performed on all patients 21 years of age or younger at diagnosis, treated for primary epithelial lung malignancies at Memorial Sloan-Kettering Cancer Center between 1980 and 2001.

Dynamic electric field assisted multi-dimensional liquid chromatography of biological samples.

Complex biological samples require very high resolution separation strategies. The platform introduced here capitalises on the hyphenation of liquid chromatographic (LC) and electric potential gradient electrochromatographic multi-dimensional separation genres. First-dimension selectivity is provided by simultaneous size exclusion (SEC) and strong cation exchange (SCX) chromatography modes, while the second dimension comprises reversed phase (RP) characteristics in a dynamic (time-variant) electric field.

Direct determination by capillary electrophoresis of cardiovascular drugs, previously included in liposomes.

The lipophilicity of some cardiovascular drugs was determined by capillary electrophoresis (CE). Mexiletine, amlodipine and indapamide, the drugs considered, were in contact with liposomial vescicles for 2, 4 or 6 h. After the contact time the drugs, penetrated into liposomial vesicles, were determined by CE using phosphate buffer (pH 6.

Micellar electrokinetic chromatography for determination of drug partition in phospholipids.

The lipophilicity of pipemidic, nalidixic and oxolinic acids was determined by forming phospholipidic micelles directly in an electrophoretic capillary. Phosphatidylcholine derivatives, namely L-alpha-dilauroyl phosphatidylcholine (DLPC) or L-alpha-dimiristoyl phosphatidylcholine (DMPC), were added in the run buffer (50 mM phosphate buffer at pH 7.4).

Renal transplantation from cadaveric donor after myocardial revascularization: still a matter of concern?

Renal transplantation in patients who have undergone coronary revascularization remains a matter of concern, few experiences have been reported in literature. From January 1997 to March 2003, 23 previously revascularized patients underwent renal transplants from cadaveric donors. We analyzed patient survival and cardiac events in this group of patients (group A) versus a similar population of 38 revascularized patients who were still on dialysis (group B) on the active waiting list (awl).

Use of a hepta-Tyr antibiotic modified silica stationary phase for the enantiomeric resolution of D,L-loxiglumide by electrochromatography and nano-liquid chromatography.

Hepta-Tyr antibiotic modified silica stationary phase was used for the chiral resolution of D,L-loxiglumide, a new drug under investigation proposed for the treatment of gastrointestinal diseases. The chiral stationary phase was packed into fused silica capillaries of 75 microm i.d.

An enantioselective imprinted receptor for Z-glutamate exhibiting a binding induced color change.

Using 1-(4-styryl)-3-(3-nitrophenyl)urea as host monomer for the imprinting of Z-(D or L)-Glu, a polymeric receptor exhibiting strong enantioselectivity and a change in color intensity upon binding of the guest was obtained.

Positional gene expression analysis identifies 12q overexpression and amplification in a subset of neuroblastomas.

Neuroblastoma is a heterogeneous disease with variable clinical behaviors. Unique molecular features are associated with clinically relevant subgroups. We performed a comprehensive microarray gene expression analysis of 95 neuroblastomas in an effort to define clinically important molecular subtypes.

Capillary electrophoresis studies on the aggregation process of beta-amyloid 1-42 and 1-40 peptides.

The possibility to monitor, in solution, the steps of beta-amyloid (Abeta) nucleation and therefore to describe this dynamic process by using capillary electrophoresis and under optimized experimental conditions is described. Striking differences in the electrophoretic patterns of Abeta 1-42 and Abeta 1-40 over time are here shown, and different aggregation states are elucidated, which reflect the very diverse oligomerization behavior of two very similar peptides. The isolation of one aggregated species of high molecular weight by ultracentrifugation allowed us to assess its role as toxic oligomer.

Approaches to imprinted stationary phases for affinity capillary electrochromatography.

The combination of two highly attractive technologies in analytical chemistry, namely molecular imprinting and capillary electrochromatography, is reviewed. Molecular imprinting represents an approach to incorporate affinity binding sites for one or a class of target molecules in network polymers whereas capillary electrochromatography is a technique that profits from the high separation efficiency of electrodriven separations and the high selectivity and capacity available with liquid chromatography. The review discusses and compares the various approaches taken, to combine these concepts aiming at robust, reproducible and easily available capillary-based affinity separation media.

Chiral investigation of midodrine, a long-acting alpha-adrenergic stimulating agent.

Midodrine hydrochloride is a peripheral alpha(1)-adrenoreceptor agonist that induces venous and arterial vasoconstriction. Midodrine, after oral or intravenous administration, undergoes enzymatic hydrolysis and releases deglymidodrine, a pharmacologically active metabolite. Midodrine and deglymidodrine have a chiral carbon in the 2-position.

Separation of tocopherols by nano-liquid chromatography.

Nanoliquid chromatography (nano-LC) was used for the separation of tocopherols (delta-, gamma-, alpha-TOH), alpha-tocopherol acetate (alpha-TOH-Ac) and an antioxidant compound, namely butylated hydroxytoluene (BHT) used to prevent TOHs autoxidation. The separation was carried out in a fused silica capillary of 100 microm I.D.

Surgical management and outcome of osteosarcoma patients with unilateral pulmonary metastases.

Purpose: The surgical management of osteosarcoma patients with unilateral pulmonary nodules is controversial. The authors reviewed their institutional experience to evaluate the incidence of occult contralateral metastases.

Methods: Data were obtained retrospectively on all consecutive osteosarcoma patients from 1980 to 2002.

The impact of gross total resection on local control and survival in high-risk neuroblastoma.

Background/purpose: Gross total resection of the primary tumor in treatment of high-risk neuroblastoma remains controversial. Furthermore, there are few reports of the effect of primary tumor resection on local control as opposed to overall survival. The authors reviewed their institutional experience to assess the effect of primary tumor resection on local control and overall survival.

Primary follicular lymphoma of the testis: excellent outcome following surgical resection without adjuvant chemotherapy.

The authors report a case of follicular lymphoma of the testis in a 3-year-old boy. Follicular lymphoma of childhood is rare, accounting for less than 5% of all non-Hodgkin lymphomas in the pediatric population. Children with follicular NHL have typically been described as presenting with localized disease, with a preponderance of male patients.

Pregnancy in kidney transplantation: satisfactory outcomes and harsh realities.

Since the first successful case of a pregnancy reported 40 yrs ago in a woman receiving a kidney transplant from her identical twin sister who did not receive immunosuppressive medications, the dream of a pregnancy in a renal transplant recipient has become reality. In women of childbearing age with a functioning transplant, the pregnancy rate has improved from 2 to 5%. Approximately 35% of pregnancies do not progress beyond the 1st trimester; the success rate is > 90% after the 1st trimester.

A substructure approach toward polymeric receptors targeting dihydrofolate reductase inhibitors. 2. Molecularly imprinted polymers against Z-l-glutamic acid showing affinity for larger molecules.

The preparation of a molecularly imprinted polymer against N-Z-L-glutamic acid using a novel bis-urea functional monomer is described. The polymer exhibits affinity for the template over N-Z-protected aspartic acid and glycine and, further, is capable of binding larger molecules, e.g.

Role of endogenous reverse transcriptase in murine early embryo development.

We report that a reverse transcriptase (RT) activity is present in early cleavage stage embryos as determined by a Polymerase chain reaction (PCR)-based detection assay. In an attempt to establish whether this activity plays a role in early embryonic development, we have blocked the endogenous RT by two independent approaches: (1) embryos were exposed to nevirapine, a highly specific nonnucleoside inhibitor of RT activity; (2) anti-RT antibody was microinjected into the nucleus of one blastomere of 2-cell embryos. When embryos were exposed to nevirapine in the developmental window between late 1-cell and 4-cell stages, development was arrested before the blastocyst stage.

Ibuprofen quality control by electrochromatography.

The quality control of drugs is generally made by HPLC. This control could be made also by capillary electrochromatography (CEC). In this paper we report the analysis by CEC of ibuprofen, a well-known anti-inflammatory non steroidic drug, and some of its impurities.

Determination of MPTP, a toxic impurity of pethidine.

Pethidine, predominantly a mu-receptor agonist, is a phenyl-piperidinic synthetic drug. It is used in the management of moderate to several pain. A possible hydrolytic degradation of an ester group can generate a very toxic compound, the N-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) which contaminates the drug.

Flexibility as an implementation strategy for a daily dialysis program.

Background: Daily hemodialysis (DHD) is an interesting dialysis option, experienced worldwide by only a few hundred patients, because of clinical and logistic limitations. This study describes the main clinical and implementation results of a flexible policy applied in starting a DHD program.

Methods: The setting is the University Nephrology Center of Turin, Italy (approximately 150 hemodialysis and 50 peritoneal dialysis (PD) patients) where in November 1998 a short daily DHD program was started.