Resistance to 6-thioguanine in mismatch repair-deficient human cancer cell lines correlates with an increase in induced mutations at the HPRT locus

Although the resistance to the cytotoxic response of certain DNA damaging agents has been well characterized in cells deficient in mismatch repair, little is known about how such resistance affects mutagenesis. Using human cancer cell lines defective in mismatch repair (MMR) and complementary cell lines in which the MMR defects were corrected by chromosome transfer, we present the cytotoxic effect and the mutagenic response at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus following exposure to the chemotherapeutic agent, 6-thioguanine (6-TG). Upon exposure to 6-TG, there was a differential cytotoxic response. The MMR-deficient cells were resistant to 6-TG exposure up to 5 microM, whereas the MMR-proficient cell lines were significantly more sensitive at the same levels of exposure. Furthermore, the mutagenic response at HPRT induced by 6-TG was substantially increased in the MMR-deficient lines relative to the MMR- proficient cell lines. These findings support the notion that cytotoxicity to 6-TG is mediated through functional MMR and that resistance to the cytotoxic effects of 6-TG is directly associated with an increase in induced mutations in MMR-defective cells. These data suggest that the use of 6-TG as a chemotherapeutic agent may result in the selection of MMR-defective cells, thereby predisposing the patient to an increased risk for developing secondary tumors.      

The use of clomiphene citrate/human menopausal gonadotrophins in conjunction with GnRH antagonist in an IVF/ICSI program is not a cost effective protocol

OBJECTIVE: To evaluate the cost effectiveness of a clomiphene citrate (CC)/human menopausal gonadotropin (hMG)/GnRH antagonist protocol versus a long-acting GnRH agonist/hMG protocol. PARTICIPANTS AND METHODS: One hundred eighty nine couples having their first trial of ICSI for male factor infertility were divided into two groups. Group I (no = 33) received CC 100-150 mg/day for five days starting from day 2 of the cycle and 150 IU of hMG/day on days 6-10. GnRH antagonist (Centrorelix) 0.25 mg/day was started when the leading follicle reached 16 mm in the absence of an LH surge. Group II (no = 156) received 0.1 mg Deacapeptyl/day as our standard long protocol. RESULTS: Clinical pregnancy was observed in 8 out of the 33 cases in group I (24%) while in group II, 92 out of 156 achieved clinical pregnancy (59%), the difference was statistically significant (P = 0.019). The cost of medications/cycle was estimated to be 1110+/-492 E.P in group I, while it was 1928+/-456 E.P. in group II. However, the total cost per pregnancy was 19653 EP in group I and 10047 EP in group II. CONCLUSION: The use of the clomid/hMG/antagonist protocol is not a cost effective strategy and should not be recommended in IVF-ICSI cycles.     

Serum fluoride levels in a group of Egyptian infants and children from Cairo city

In this study, the authors investigated fluoride levels in the serum of infants and children (n = 296) and in the breast milk from nursing mothers (n = 60) in Cairo city. Their goal was to evaluate the necessity and safety of implementing a fluoride supplementation program. The authors used an ion-selective electrode to assay fluoride by direct potentiometry. Also, 2- to 12-yr-old participants underwent clinical dental examinations to detect caries and/or fluorosis. The serum fluoride levels of infants were significantly lower than levels found in preschoolers and school-age children. Serum fluoride correlated positively with age; it was significantly lower during the 1st than 2nd yr of infancy (p = 0.005). Breast or formula feeding did not influence serum fluoride status; the fluoride levels in mothers' milk reflected the serum levels of their own infants. Dental examinations revealed that 81% of the children had caries, whereas there was no evidence of fluorosis. Serum fluoride levels did not vary with the presence or absence of dental caries and did not correlate with the number of decayed, missing, or filled teeth. Gender did not influence serum fluoride expression, and the percentile values were unrelated to height, weight, or head circumference. These findings suggest the necessity and safety of improving the fluoride consumption levels of infants and children in Cairo city. Wider-scale studies are needed to obtain better insight into the problem.     

Design and synthesis of some substituted 1H-pyrazolyl-thiazolo[4,5-d]pyrimidines as anti-inflammatory-antimicrobial Agents

The synthesis of two novel series of structurally related 1H-pyrazolyl derivatives of thiazolo[4,5-d]pyrimidines is described. All the newly synthesised compounds were examined for their in vivo anti-inflammatory activity in two different bioassays namely; cotton pellet-induced granuloma and carrageenan-induced paw edema in rats. The in vitro inhibitory activity of the most active compounds towards human COX-1 and COX-2 enzymes was also estimated. In addition, the ulcerogenic effects and acute toxicity (LD(50)) values of these compounds were determined. The same compounds were evaluated for their in vitro antimicrobial activity against Escherichia coli, as an example of Gram negative bacteria, Staphylococcus aureus as an example of Gram positive bacteria, and Candida albicans as a representative of fungi. The results revealed that compounds 5a, 9a, 9b, 10b and 12a exhibited anti-inflammatory activity comparable to that of indomethacin in both local and systemic in vivo animal models with no or minimal ulcerogenic effects (0-10%) and high safety margin (LD(50) > 500 mg kg(-1)). In addition, most of them displayed appreciable antibacterial activities when compared with ampicillin, especially against S. aureus. Compounds 9a and 12a are the most distinctive derivatives identified in the present study because of their remarkable in vivo and in vitro anti-inflammatory activity in addition to their pronounced antibacterial activities comparable to ampicillin against Gram positive and -negative bacteria. Therefore, they are considered as successful dual anti-inflammatory-antimicrobial candidates.     

Design and synthesis of some substituted 1H-pyrazolyl-oxazolidines or 1H-pyrazolyl-thiazolidines as anti-inflammatory-antimicrobial agents

Four series of 1 H-pyrazole derivatives have been synthesized. The first series was synthesized starting with the reaction of 3-(5-bromo-2-thienyl)-1-phenyl-1 H-pyrazole-4-carboxaldehyde 1 with L-serine, L-cysteine, or L-penicillamine, followed by N-protection using (Boc)(2)O to provide compounds 2. The latter compounds could be N-deprotected by 4N HCl/dioxane to afford the second series 3 or reacted with NH(4)OH in the presence of DCC/HOBt to give the corresponding amides 4 followed by N-deprotection giving rise to compounds 5. The newly synthesized compounds were evaluated for their anti-inflammatory-antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compound 5b (2RS, 4R)-2-[3-(5-bromo-2-thienyl)-1-phenyl-1H-pyrazol-4-yl]-5-methylthiazolidine-4-carboxamide, proved to be the most active anti-inflammatory-antimicrobial agent in the present study with a good safety margin and no ulcerogenic effect.     

In situ nasal absorption of midazolam in rats

Intranasal (i.n.) midazolam (MDZ) administrations may be used successfully for preoperative sedation, especially in young patients. However, clinicians have to use the commercial parenteral formulation, the low pH of which (3.3), necessary to solubilize MDZ (pK(a) 6.1), is probably responsible for the signs of local irritation frequently reported. As a starting point to design a formulation suitable for the nasal route, MDZ nasal absorption was investigated in rats. The effects of the MDZ solution concentration (10--100 microg/ml), osmolality (from less than 10 mOsm/kg up to 450 mOsm/kg) and pH (3.3--7.4) were studied using an in situ perfusion technique. MDZ was determined by reversed-phase HPLC in the circulating solution and results were expressed in clearance terms. MDZ absorption was independent of its concentration. The pH of the solutions was the key-parameter and only a pH above 4 allowed significant absorption. These results were consistent with a passive diffusion absorption of MDZ and partly followed the pH partition theory. In conclusion, satisfactory MDZ absorption should be expected with a formulation at a pH suitable for the nasal route in human (5.5--6.5).     

Synthesis and preliminary antimicrobial screening of new benzimidazole heterocycles

A series of 2-methylbenzimidazole incorporated to different heterocycles through ethyl or carbamoylethyl groups at position 1 of benzimidazole were synthesized. Also 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide incorporated with semicarbazides and thiosemicarbazides were prepared. Moreover, the triazole 5e underwent Michael addition and alkylation reaction. Some of the newly synthesized compounds showed considerable antimicrobial activity against gram positive, negative bacteria and yeast.     

PMD4 Outcomes Research Interests of a Community Pharmacist Research Network

OBJECTIVE: This purpose of this project was to document the outcomes research interests of members of a statewide Community Pharmacist Research Network (CPR-Net).
METHODS: Pharmacists electing to participate in the CPR-Net completed a survey in which they were asked to rank on a scale of 1 to 5 (1 = low interest, 5 = high interest) their interest in conducting outcomes-related research projects (Pharmacy Care, Health Related Quality of Life, Pharmacoeconomics, and Product Evaluation) in 21 disease states. These projects would be conducted in their pharmacies in conjunction with four faculty members from a college of pharmacy.
RESULTS: CPR-Net members ranked diabetes mellitus and hypertension as the most common disorders (93.8% each) in which they would be interested in conducting research projects. Other diseases in which a high interest level was demonstrated include asthma (85.4%), hypercholesterolemia (83.3%), and arthritis (81.2%). An intermediate level of interest was demonstrated with COPD (77%), allergic rhinitis (77%), child health issues (77%), and peptic ulcer disease (72.9%). Diseases in which a low interest level was expressed include AIDS/HIV (18.8%), epilepsy (12.5%), and thyroid disorders (12.5%). Additionally, 10.4% of pharmacists expressed low interest levels in conducting studies in patients with arrhythmias, congestive heart failure, depression, and anxiety.
CONCLUSION: Community pharmacists in this research network are most interested in conducting outcomes-related research projects in patients with common, expensive, chronic diseases.     

Primary hyperaldosteronism causing posttransplantation hypertension: localization by adrenal vein sampling

A 58 year-old man with end-stage renal disease who had received a cadaveric renal transplant presented with persistent hypertension and hypokalemia. Allograft renal artery stenosis, rejection, and cyclosporine effects were excluded. Hypokalemia persisted despite potassium supplementation and antihypertensive medications with hyperkalemic effects. The biochemical findings of primary hyperaldosteronism with a normal adrenal anatomy imaged by magnetic resonance imaging (MRI) necessitated adrenal vein sampling to lateralize a left adrenal adenoma. His hypokalemia was cured by the removal of the adenoma, and his blood pressure (BP) control was easily achieved with a less complex regimen of antihypertensives. We suggest that the concomitant existence of resistant hypokalemia and posttransplantation hypertension, especially in the cyclosporine era, should stimulate a search for hyperaldosteronism; once transplant renal artery stenosis has been excluded, the patient should be investigated for primary hyperaldosteronism. When imaging studies fail to show adrenal pathology, adrenal vein sampling will likely do so.