AIMTo evaluate the characteristics, the hypoglycemic efficacy and the pharmacokinetics of the insulin-liposomes double-coated by chitosan (CH) and chitosan-EDTA conjugates (CEC).

METHODSInsulin-liposomes were prepared by reversed-phase evaporation. The protection of insulin against peptic and tryptic digestion was studied with HPLC. The hypoglycemic effects of insulin-liposomes were investigated using the glucose oxidase method after oral administration to rats. Serum insulin concentration in rats were determined by radio-immunoassay, and were assessed by Pkanalyst computer program.

RESULTSThe insulin-liposomes double-coated by CH and CEC was shown to protect insulin against digestion of pepsin, trypsin and gastrointestinal contents. In glucose tolerance test in normal rats, as compared with phosphate buffer solution control group, the insulin-liposomes coated by CH and CEC could reduce the glucose-induced peak of hyperglycemia. The reduction of the insulin-liposomes double-coated by CH and CEC was superior to that of other insulin-liposomes. When administered intragastrically to normal rats, the insulin-liposomes coated by CH and CEC could reduce glycemia measured after an overnight fast. The hypoglycemic effect the insulin-liposomes double-coated by CH and CEC was superior to that of other insulin-liposomes, and the dosage of 50 mu x kg(-1) decreased by 45.98% of initial blood glucose level at 1 h. As compared with subcutaneous injection, the relative pharmacological bioavailability was 17.02% calculated by area under the curve of glucose level versus time profile after oral administration of the insulin-liposomes double-coated by CH and CEC to rats. The serum insulin concentration-time curves were found to best fit the one-compartment open model. As compared with subcutaneous injection, the relative bioavailability was 8.91% calculated by the area under the curve of serum insulin concentration versus time profile after oral administration of the insulin-liposomes double-coated by CH and CEC to rats.

CONCLUSIONThe stability and absorption of insulin-liposomes double-coated by CH and CEC was superior to that of the insulin-liposomes coated either by CH, or by CEC respectively.

Administration, Oral ; Animals ; Biological Availability ; Blood Glucose ; metabolism ; Chitosan ; chemistry ; Delayed-Action Preparations ; Drug Carriers ; Drug Delivery Systems ; Edetic Acid ; chemistry ; Hypoglycemic Agents ; administration & dosage ; pharmacokinetics ; pharmacology ; Insulin ; administration & dosage ; pharmacokinetics ; pharmacology ; Liposomes ; Male ; Nanotechnology ; Particle Size ; Rats ; Rats, Sprague-Dawley ; Technology, Pharmaceutical ; methods

AIMTo study the effect of the liposomes coated by chitosan and its derivatives as oral dosage form for peptide drugs on the gastrointestinal (GI) transit of drugs.

METHODSInsulin-liposomes were prepared by reversed-phase evaporation. The in situ perfusion experiment was used to investigate the enteral absorption of insulin. The hypoglycemic effects of insulin were investigated using the glucose oxidase method after administration in rats. The insulin concentrations of serum and enteral tissues were determined by radio-immunoassay in rats.

RESULTSIn in situ local intestinal perfusion experiment, the duodenum was the best segment for the absorption of the insulin liposomes coated by chitosan (CH) or chitosan-EDTA conjugates (CEC) , and double-coated by CH-CEC; the colon was the best segment for the absorption of the insulin solution from rat intestine; but the best segment for the absorption of the uncoated and N-trimethyl chitosan chloride (TMC) coated insulin liposomes was unclear. In all segments, the enteral absorption of the insulin liposomes double-coated by CH-CEC was superior to that of other insulin liposomes.

CONCLUSIONThe insulin-liposomes coated by chitosan and its derivatives can enhance enteral absorption of insulin and increase stability of insulin in GI tract.

Animals ; Area Under Curve ; Chitosan ; chemistry ; Colon ; metabolism ; Delayed-Action Preparations ; Drug Carriers ; Drug Delivery Systems ; Duodenum ; metabolism ; Edetic Acid ; chemistry ; Gastrointestinal Transit ; Hypoglycemic Agents ; administration & dosage ; pharmacokinetics ; Insulin ; administration & dosage ; pharmacokinetics ; Intestinal Absorption ; Liposomes ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the correlation between male infertility and Y chromosome microdeletions of azoospermia factor (AZF) regions, and to establish a reliable genetic diagnosis in idiopathic infertile male patients with azoospermia or severe oligozoospermia. METHODS: Multiplex PCR amplification of 6 sequence-tagged sites in AZF regions of the Y chromosome was examined among 100 normal karyotype male patients with azoospermia or oligozoospermia. RESULTS: Four patients (4%) had Y chromosome microdeletions, the microdeletions of 3 patients were idiopathic azoospermic and those of the other 1 patient were secretory azoospermia. CONCLUSION The PCR-based Y chromosome microdeletion screening is simple and effective in the diagnosis of patients with severe male infertility. Microdeletion of Y chromosome is one of the major causes of severe dyszooospermia.
Adult ; Azoospermia ; genetics ; Chromosome Deletion ; Chromosomes, Human, Y ; genetics ; Genetic Loci ; Humans ; Infertility, Male ; diagnosis ; genetics ; Karyotyping ; Male ; Oligospermia ; genetics ; Seminal Plasma Proteins ; genetics

Bladder cancer （BCa） is the most common malignant tumor of the urinary system， and its incidence is increasing year by year. At present， for all patients with resectable non-metastatic muscle-invasive BCa， radical cystectomy + bilateral pelvic lymph node dissection is strongly recommended， but they still face the risk of recurrence， metastasis and death. In recent years， the proportion of patients with advanced and metastatic BCa is increasing among patients with newly diagnosed BCa. Although current treatment models are diverse， they often struggle to achieve significant efficacy due to their low effectiveness and adverse effects， resulting in low survival rates for patients with advanced and metastatic BCa. Therefore， the treatment of BCa still faces great challenges， and there is an urgent need to discover an effective new antitumor drug. With the improvement of medical standards， traditional Chinese medicine has shown great advantages in the treatment of BCa. Traditional Chinese medicine is mild and easy to accept， and can inhibit tumor progression through a multi-pathway， multi-way and multi-target manner， so as to exert its anticancer effect. Taraxaci Herba is a medicinal and food homologous plant， which has many biological activities， such as antibacterial， anti-inflammatory， anti-oxidation， anti-tumor， protecting liver and gallbladder， reducing blood sugar and enhancing immunity， and it has shown a clear anticancer effect in breast cancer， liver cancer， gastric cancer， tongue cancer and lung cancer. By reviewing previous studies worldwide， this article summarizes the mechanism of Taraxaci Herba extract in inducing autophagy and apoptosis， inhibiting cell migration and invasion， regulating cell cycle and proliferation， regulating cell metabolism， inhibiting tumor angiogenesis， combining the effects of chemotherapeutic drugs， and regulating the transduction of related signal pathways. On this basis， this study systematically elaborates on the potential mechanism of Taraxaci Herba against BCa， in order to provide a theoretical basis for the research and treatment of BCa.

OBJECTIVE: To evaluate the safety of preoxygenation with high-flow nasal oxygenation in elderly patients during induction of general anesthesia with endotracheal intubation. METHODS: Fifty-six elderly patients without difficult airway were randomized equally into high-flow nasal oxygen group (HF group) and conventional mask oxygen group (M group). Preoxygenation was performed for 5 min before induction of general anesthesia and endotracheal intubation. Oxygenation was maintained during laryngoscopy in HF group, and ventilation lasted until laryngoscopy in M group. For all the patients, the general data, cross-sectional area (CSA) of the gastric antrum measured by ultrasonography, arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂) and arterial oxygen saturation (cSO₂) were recorded before preoxygenation (T1), at 5 min of preoxygenation (T2) and immediately after intubation (T3). The safety time of asphyxia, intubation time, times of mask ventilation and postoperative complications were compared between the two groups. RESULTS: The general data were comparable between the two groups. After 5 min of preoxygenation, PaO₂ and cSO₂ were significantly increased in both groups, and PaO₂ was significantly higher in HF group than in M group (F=118.108 vs 9.511, P < 0.05). Both PaO₂ and cSO₂ decreased after intubation, but PaO₂ decreased more slowly in HF group and still remained higher than that at T1; cSO₂ decreased significantly in M group to a lower level than that at T1. Compared with those in M group, the patients in HF group showed a significantly longer safety time of asphyxia (t=5.305, P < 0.05) with fewer times of mask ventilation (χ²= 6.720, P < 0.05). PaCO₂ increased after intubation in both groups but was comparable between the two groups (F=3.138, P > 0.05). CONCLUSION High-flow nasal oxygen is safe, simple and effective for pre-oxygenation, which, as compared with the conventional oxygen mask, improves arterial oxygen partial pressure and prolongs the safety time of asphyxia to ensure the safety of airway management during induction of general anesthesia in elderly patients with endotracheal intubation.
Aged ; Anesthesia, General ; Asphyxia ; Humans ; Intubation, Intratracheal ; Oxygen ; Partial Pressure