The aim of this work was to study in rats the nasal route for the brain delivery of the vasoactive intestinal peptide (VIP) neuropeptide. After evaluating VIP stability in solutions obtained from nasal washes, the effect of formulation parameters (pH 4-9, 0-1% (w/v) lauroylcarnitine (LC), hypo- or isoosmolality) on the brain uptake of intranasally administered VIP (10(-8)M)/125I-VIP (300,000 cpm/ml) was studied, using an in situ perfusion technique. Brain radioactivity distribution was assessed by quantitative autoradiographic analysis. Results were compared to intravenously administered VIP. With a hypotonic formulation at pH 4 containing 0.1% LC and 1% bovine serum albumin, VIP stability was satisfactory and loss by adsorption was minimal. Using this formulation, around 0.11% of initial radioactivity was found in the brain after 30 min perfusion and was located in the olfactory bulbs, the midbrain and the cerebellum. HPLC analysis of brain and blood extracts demonstrated the presence of intact VIP in brain and its complete degradation in the blood compartment. By intravenous administration, no intact VIP was found either in brain or in blood. In conclusion, intact VIP could be delivered successfully to the brain using the intranasal route for administration.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0378-5173(03)00039-5 | DOI Listing |
Food Res Int
December 2024
Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, Alberta T4L 1W1, Canada. Electronic address:
Meat product labels including information on livestock production systems are increasingly demanded, as consumers request total traceability of the products. The aim of this study was to explore the potential of visible and near-infrared spectroscopy (Vis-NIRS) to authenticate meat and fat from steers raised under different feeding systems (barley, corn, grass-fed). In total, spectra from 45 steers were collected (380-2,500 nm) on the subcutaneous fat and intact longissimus thoracis (LT) at 72 h postmortem and, after fabrication, on the frozen-thawed ground longissimus lumborum (LL).
View Article and Find Full Text PDFFront Oncol
June 2024
Department of Pediatric Surgery, The First Affiliated Hospital of Xiamen University, Xiamen University, Xiamen, Fujian, China.
A 13-year-old boy was admitted to the hospital with 1-month history of neck pain and a 2-week history of bilateral hip joint pain accompanied by low fever. Positron emission tomography-computed tomography (PET-CT) revealed the presence of a malignant tumor in the left kidney with metastases to the left renal hilum, retroperitoneum, para-aortic lymph nodes, and multiple bone sites throughout the body. Given that the patient's left kidney capsule was intact and the boundary with surrounding tissues was clear, left nephrectomy was performed.
View Article and Find Full Text PDFPLoS One
March 2024
The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China.
An important cellular barrier to maintain the stability of the brain's internal and external environment is the blood-brain barrier (BBB). It also prevents harmful substances from entering brain tissue through blood circulation while providing protection for the central nervous system. It should be noted, however, that the intact BBB can be a barrier to the transport of most drugs into the brain via the conventional route of administration, which can prevent them from reaching effective concentrations for the treatment of disorders affecting the central nervous system.
View Article and Find Full Text PDFPathol Res Pract
February 2024
Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing 100053, China; Clinical Research Center for Epilepsy, Capital Medical University, Beijing 100053, China; Beijing Municipal Geriatric Medical Research Center, Beijing 100053, China. Electronic address:
BMC Musculoskelet Disord
January 2024
Department of Spine Surgery, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China.
Objectives: Modified cortical bone trajectory (MCBT) technique was proposed by our team in previous studies, but its biomechanical properties at adjacent segments have not been discussed yet. Therefore, the purpose of this study is to investigate the biomechanical properties of modified cortical bone trajectory (MCBT) technique on adjacent segment degeneration (ASD) in transforaminal intradiscal lumbar disc fusion (TLIF) compare to traditional bone trajectory (TT) technique and cortical bone trajectory (CBT) technique.
Methods: The four human cadaveric lumbar specimens were provided by the anatomy teaching and research department of Xinjiang Medical University and four intact finite element models of the L1-S1 segment were generated.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!