Lack of interaction between cefdinir and calcium polycarbophil: in vitro and in vivo studies

The effect of calcium polycarbophil on the absorption of cefdinir, cephalosporin derivative, was evaluated in both in vitro and in vivo studies. In the in vitro study, the release of cefdinir from a cellulose membrane in the presence or absence of metal cations was measured using the dissolution test procedure. In the in vivo study, volunteers and a randomized crossover design with two phases were used. In the first phase, the volunteers received 200 mg of cefdinir alone (Study 1); in the other phase, they received 200 mg of cefdinir and 1200 mg of fine calcium polycarbophil granules concomitantly (Study 2). The cefdinir concentrations in the samples or serum were measured by an UV-VIS spectrophotometer or high-performance liquid chromatography. Release in the presence of iron ions was slower than that in the absence of metal ions, however no difference was observed between release in the presence of calcium ions and that in the absence of metal ions. No difference was observed in AUC(0-10), C(max) and t(max) between Study 1 and Study 2. The absorption of cefdinir was not affected by co-administration of calcium polycarbophil. Moreover, the in vitro study on the release of drugs from a cellulose membrane may predict the absorption of a drug caused by the formation of chelate complexes between the drug and metal ions.     

Differential development of cation-chloride cotransporters and Cl- homeostasis contributes to differential GABAergic actions between developing rat visual cortex and dorsal lateral geniculate nucleus

A recent study suggested that gamma-aminobutyric acid (GABA) plays differential roles in activity-dependent plasticity between the visual cortex (VC) and the dorsal lateral geniculate nucleus (dLGN). In the present study, to investigate differential GABAergic functions in postnatal visual system development, the development of [Cl(-)](i), cation-Cl(-) cotransporter expression, and the [Ca(2+)](i) responses evoked by GABA were compared between VC and dLGN during the early stages of development. Using rat brain slices from postnatal days (P) 0-17, GABA-evoked [Ca(2+)](i) responses and resting [Cl(-)](i) were measured by means of optical imaging of Ca(2+) and Cl(-), respectively. Changes in the expression of cation-Cl(-) cotransporters (viz. the outwardly-directed K(+)-Cl(-) cotransporter, KCC2, and the inwardly-directed Na(+),K(+)-2Cl(-) cotransporter, NKCC1) were examined in VC and dLGN by in situ hybridization. At birth, the excitatory actions of GABA were powerful in VC, but missing in dLGN (as indicated by neuronal [Ca(2+)](i) transients), and the resting [Cl(-)](i) was significantly higher in VC than in dLGN. Signals for KCC2 mRNA expression were significantly higher in dLGN than in VC at P0. This suggests that extrusion of Cl(-) from neurons is stronger in dLGN than in VC at P0, so that a GABAergic excitatory effect was not observed in dLGN because of more negative equilibrium potential for Cl(-). The present study indicates clear differences in the molecular and physiological bases of Cl(-) homeostasis and GABA actions between the developing VC and dLGN. Such differential GABAergic actions may underlie the distinct mechanisms involved in VC and dLGN development within the visual system.     

Generation of free radicals and/or active oxygen by light or laser irradiation of hydrogen peroxide or sodium hypochlorite

Generation of free radical and/or active oxygen by light or laser irradiation of hydrogen peroxide (H2O2) or sodium hypochlorite (NaClO), which have been used for tooth whitening or root canal irrigation, was investigated using electron spin resonance spectroscopy combined with a spin-trapping technique. When H2O2 was exposed to light or laser radiation, the amount of hydroxyl radical generated changed according to the concentration of H2O2 and irradiation time. The amount of 5,5-dimethyl-1-pyrrolidone-(2)-oxyl-(1) (DMPO-X) also changed in accordance with irradiation time. The amounts of hydroxyl radical generated from H2O2 after irradiation were in the order: plasma lamp > halogen lamp > He-Ne laser > Yellow He-Ne laser. On the other hand, the amounts of DMPO-X generated from NaClO after irradiation were in the order: plasma lamp > Yellow He-Ne laser > halogen lamp > He-Ne laser.     

Four cases of non-clostridial gas gangrene with diabetes mellitus

We report four cases of non-clostridial gas gangrene. All cases were associated with diabetes mellitus as the underlying disease. Case 1: a 60-year-old male developed an ulcerative lesion on the dorsum of his left foot. Peptostreptococcus asaccharolyticus, Citrobacter freundii and Staphyrococcus epidermidis were identified in culture from odoriferous pus. Case 2: a 81-year-old female developed a lesion on her vulva spreading to the right lower abdomen. Bacteroides bivius, Peptostreptococcus asaccharolyticus and Streptococcus faecalis were identified in culture of the odoriferous pus. Case 3: a 80-year-old male developed a swollen area with ulcer on the right foot. Bacteroides fragiris, Enterococcus faecalis, Proteus mirabilis, Enterococcus avium and Enterococcus faecalis were identified by culture. Case 4: a 52-year-old female developed swelling of her left groin. Enterococcus faecalis and Streptococcus anginosus were identified in culture from the odoriferous pus. In all patients, a radiological examination revealed the presence of subcutaneous gas in the lesion. Prognosis of non-clostridial gas gangrene is usually poor. These four patients, however, all survived. Once an infectious sign is seen in the diabetic patient, it is important to discover a gas figure by using the radiological examination (plain film or computed tomography). Earlier diagnosis and debridement are the most important for a better prognosis. Because workers with diabetes mellitus are now increasing in number, occupational physicians should always keep in mind that a serious infectious disease like non-clostridial gas gangrene can develop even from minor accidental trauma, and they should control the working environment in the workplace where accidents often happen.     

Relationships between the in vitro cytotoxicity and transport characteristics of pirarubicin and doxorubicin in M5076 ovarian sarcoma cells, and comparison with those in Ehrlich ascites carcinoma cells

PURPOSE: We sought to determine whether the de novo resistance of M5076 ovarian sarcoma cells, which show sensitivity to pirarubicin (THP), to doxorubicin (DOX) is due to differences in the transport characteristics between THP and DOX, and the results were compared with those for drug-sensitive Ehrlich ascites carcinoma cells. METHODS: The in vitro cytotoxicity of the drugs was assessed by means of the tetrazolium dye assay. Transport experiments were performed by the rapid centrifugation method. RESULTS: In an in vitro cytotoxicity experiment, M5076 cells showed lower sensitivity to DOX than to THP, and the cytotoxicity of THP and DOX toward M5076 cells was lower than toward Ehrlich cells, and these results were similar to those of an in vivo experiment. This was due to the much lower expression of topoisomerase II in M5076 cells than in Ehrlich cells. The amount of intracellular DOX was found to be significantly lower than that of THP in both cell types, and furthermore, little free intracellular DOX was observed in M5076 cells, indicating that the low sensitivity of M5076 cells to DOX was partially a result of the low amount of intracellular DOX. There was no difference in the efflux rate, but there was an apparent difference in the uptake efficiency of the carrier between THP and DOX. CONCLUSIONS: These findings suggest that the cytotoxicities of THP and DOX toward M5076 and Ehrlich cells depend, at least in part, on the uptake efficiency of the carrier.     

A patient with advanced gastric cancer in the gastric tube whose QOL was improved by TS-1

We present the case of a 72-year-old man with gastric tube cancer accompanied by multiple liver metastases, after esophagectomy for esophageal cancer, whose quality of life (QOL) was improved with a small dosage of TS-1. The patient's high serum AFP level suggested alpha-fetoprotein-producing gastric cancer. He was treated with half the standard dose of TS-1, because the patient's poor general condition necessitated chemotherapy with low toxicity and high efficacy. The daily dose was 40 mg for the first three courses and 50 mg for the last two. Each treatment course consisted of a four-week administration followed by two drug-free weeks. The patient received five courses of chemotherapy at our outpatient clinic before his death from re-progression of liver metastasis. No serious side effect except temporary stomatitis was observed. A decrease in tumor markers, alpha-fetoprotein and carcinoembryonic antigen, was obtained after 4 weeks. After 2 cycles, computed tomography and endoscopy examinations showed regression of the primary tumor and liver metastases, and tumor markers were decreased remarkably. The patient's QOL improved gradually after the treatment. His performance status before the chemotherapy was 3, and improved to 1 after two cycles. The small dosage of TS-1 was effective without any adverse effects, and improved the patient's QOL, for 6 months.     

Intra-arterial chemotherapy with gemcitabine (GEM) for unresectable pancreatic cancer

PURPOSE: Most patients with pancreatic cancer are unresectable because of local invasion and liver metastasis at the time of diagnosis. To date, no treatment has had a significant impact on this disease. To deliver a high concentration of drug to the cancer, intra-arterial chemotherapy with GEM was performed in two patients with unresectable advanced cancer. PATIENTS AND METHODS: One patient, a 70-year-old man with liver metastasis, was treated with arterial infusion of GEM 1,000 mg/body. Another patient, a 55-year-old woman with local invasion and distant metastatic lymphadenopathy, was given intra-arterial infusion of GEM 400 mg and intra-venous infusion of GEM 1,000 mg/body. The patients were given GEM weekly for 3 weeks followed by a week of rest. RESULTS: In the first patient, the pain went away and CEA was decreased for 6 months. After that, the patient died due to intra-abdominal dissemination within 4 months. In the other patient, the pain went away. Tumor markers, such as CEA and CA19-9, were normalized and primary pancreatic cancer was reduced locally. The patient currently has a metastatic liver tumor, but she has had a significant improvement in performance status. CONCLUSION: Intra-arterial chemotherapy with GEM may be tolerated in patients with unresectable pancreatic cancer.     

Intrinsic angiotensin II-generating system in human pancreatic cancer tissues

To clarify whether an intrinsic angiotensin II-generating system exists in human advanced pancreatic cancer tissues, we measured angiotensin II concentration and angiotensin converting enzyme (ACE) activity in tissues of normal pancreas, pancreatic cancers, colon cancers and hepatocellular carcinomas. After the surgically resected specimens were homogenized, angiotensin II concentration and ACE activity in tissues were measured using the florisil method and Kasahara's method, respectively. Tissue angiotensin II levels in pancreatic cancers (n = 13) were significantly higher than those of normal pancreas (n = 7), colon cancers (n = 7), or hepatocellular carcinomas (n = 7). However, there was no significant difference in tissue ACE activity between them. This study provides in vivo evidence of ACE-independent angiotensin II-generating system in human pancreatic cancer tissues and suggests that this locally-formed angiotensin II influences the microenvironment of pancreatic cancer tissues in a paracrine fashion.     

Developmental changes in KCC1, KCC2 and NKCC1 mRNAs in the rat cerebellum

Cation chloride cotransporters are considered to play pivotal roles in controlling the intracellular and extracellular ionic environments of neurons, hence controlling neuronal function. To establish how these cotransporters are involved in cerebellum development, we investigated the expression of KCC1, KCC2 and NKCC1 mRNAs in the developing rat cerebellum using in situ hybridization histochemistry. In the external germinal layer, where premature cells exist, we found substantial KCC1 and NKCC1 mRNA expression on P7 and P14, while KCC2 mRNA was not detected. In contrast, KCC2 mRNA was already expressed in Purkinje cells on P1. We also observed KCC2 mRNA expression in postmigratory granule cells after P7. The expression of KCC1, KCC2, and NKCC1 mRNAs reached adult patterns by P21. In the adult cerebellum, KCC2 mRNA was expressed in most neurons, including Purkinje cells, granule cells, and stella/basket cells, while KCC1 and NKCC1 mRNAs were only detected in granule cells and glial cells. These findings suggest that in the rat cerebellum KCC2 mRNA expression is induced when neurons arrive their final destinations.