A simple method for beveling micropipettes for intracellular recording and current injection

Summary A simple equipment for beveling intracellular microelectrodes has been made by modifying a conventional turntable. An agar disc containing ceric oxide polishing compound which was put on a flat glass disc was found to be suitable for beveling of Pyrex single- and double-barreled micropipette electrodes with a tip diameter larger than 0.1 m. Although the beveled microelectrodes have not always been shown to give better cell penetration into the frog retinal rods than unbeveled fine ones, better records could usually be obtained when electric currents were injected into cells, probably being due to their lower resistance, noise, tip potentials and coupling resistance between two barrels.     

A simple method to heparinize biological materials

A new method was developed inducing antithrombogenicity to biologic materials. A basic protein, protamine, was used to increase heparin binding to collagenous materials. Protamine sulfate solution was poured into a collagen-rich material (porcine ureter). The protamine adsorbed to the collagen was then cross-linked to the material by glutaraldehyde. The collagen-protamine complex was then interacted with a heparin solution to ionically bind heparin to the material. The amount and the distribution of the bound heparin can be controlled by changing the protamine fixation to the material. A heparinized porcine ureter as a vascular substitute showed excellent antithrombogenicity in experimental animal studies. This method is expected to be used as method for developing antithrombogenic artificial organs, and as a method for the development of antiadhesive membranes.     

A simple and reproducible method to evaluate granulocyte adherence

A simple method was devised to measure granulocyte adherence in whole blood. Columns of glass beads (4.5 mm diameter) in disposable plastic syringes were used. The assay showed great reproducibility when done in triplicate, the day to day variations in a given individual being minimal. Previous incubation of the blood with different ethanol concentrations diminished granulocyte adherence. The assay is easy to perform and does not require special equipment.     

A simple and versatile avoidance chamber for mice requiring no shock scrambler

We present a simple two-chamber apparatus for avoidance training of mice which does not require a shock scrambler. This apparatus can be used for active, passive and discriminated (Go-No-GO) avoidance tasks.     

A simple method to demonstrate duodenal gastric metaplasia

AIMS: The diagnosis of duodenal gastric metaplasia (DGM) is based on the demonstration of periodic acid Schiff (PAS) positive mucin in duodenal columnar cells. Recently, groups of duodenal columnar cells were seen to be autofluorescent in haematoxylin and eosin (H&E) stained sections from a patient with DGM. MATERIALS AND METHODS: Consecutive archival gastric and duodenal H&E sections from 30 patients with chronic gastritis and DGM (CG+DGM), from 30 with chronic gastritis without DGM (control group I), from 30 with normal gastric and duodenal mucosa (control group II), and from five patients with coeliac disease (control group III) were reviewed on a fluorescent microscope. RESULTS: The surface epithelium of the gastric mucosa in all 95 cases had autofluorescent material. In 31 cases with DGM (including one unreported case in control group I), groups of columnar duodenal cells also had autofluorescent material. In the remaining 64 cases, duodenal columnar cells were not autofluorescent. Results were confirmed with the PAS stain. CONCLUSIONS: The method described detected apical mucin secretion in columnar cells, both in the stomach and in the duodenum from patients with DGM. The autofluorescence was induced by eosin (which binds to neutral mucin). Observing H&E stained duodenal biopsies under a fluorescence microscope may be sufficient to confirm DGM or to detect incipient DGM. Despite long observation periods and a long exposure time while photographing, the autofluorescence did not fade away. Because re-cuttings for special staining (PAS) are no longer required when this method is used, both final diagnosing time and laboratory costs can be reduced.     

A simple method to optimize hospital beds capacity

OBJECTIVE: The number of acute hospital beds is determined by health authorities using methods based on ratios and/or target bed occupancy rates. These methods fail to consider the variability in hospitalization demands over time. On the other hand, the implementation of sophisticated models requires the decision concerning the number of beds to be made by an expert. Our aim is to develop a new method that is as simple to use as the ratio method while minimizing the roundabout approaches of these methods. METHOD: A score was constructed with three parameters: number of transfers due to lack of space, number of days with no possibility for S unscheduled admissions and number of days with at least a threshold of U unoccupied beds. The optimal number of beds is the number for which both the mean and the standard deviation of the score reach their minimum. We applied this method to two internal medicine departments and one urological surgery department and we compared the solutions proposed by this method with those put forward by the ratio method. RESULTS: The solutions proposed by this method were intermediate to those calculated by the local and national length of Stays ratio methods. Simulating an unusual increase in admission requests had no consequence on the bed number selected, indicating that the method was robust. CONCLUSION: Our tool represents a real alternative to the ratio methods. A software has been developed and is now available for use.     

A robust and simple security extension for the medical standard SCP-ECG

This paper proposes a SCP-ECG security extension after having analyzed the features of this standard, its security requirements and the current measures implemented by other medical protocols. Our approach permits SCP-ECG files to be stored safely and proper access to be granted (or denied) to users for different purposes: interpretation of the test, consultation, clinical research or teaching. The access privileges are scaled by means of role-based profiles supported by cryptographic elements (ciphering, digital certificates and digital signatures). These elements are arranged as metadata into a new section which extends the protocol and protects the remaining sections. The application built to implement this approach has been extensively tested, showing its capacity to authenticate users and to protect the integrity of files and the privacy of sensitive data, with a low impact on file size and access time. In addition, this solution is compatible with any version of the SCP-ECG and can be easily integrated into e-health platforms.     

A simple,rapid method for freezing hybridomas

Summary A simple, rapid method for freezing hybridomas in bio-freeze vials and in situ in 96-well microculture cluster plates is described. The method offers a convenient means of preserving hybridomas and a more manageable system for distributing the workload necessitated by the exponential increase in the number of wells after fusion or cloning or both.     

一种快速简单显示神经元树突棘的Golgi-Cox法(英文)

现存很多高尔基染色法有成功率低、产生沉淀或操作程序复杂等缺点。本文报道了我们发展的显示大脑皮层神经元树突棘的另一种Gogli-Cox染色方法。其方法是将动物灌注固定后取脑并将全脑浸于Golgi-Cox液中2周,然后浸于30%蔗糖中;反应采用100微米厚的震动切片,经过蒸馏水洗涤、氨化、酸性坚膜定影液反应、蒸馏水再洗涤,然后切片经上升梯度酒精脱水、透明,裱片后观察。结果显示,神经元的形状和树突棘标记十分清楚;相比之下,我们采用的另一种应用K2S的Golgi-Cox法则标记质量很差。本研究结果提示我们使用酸性坚膜定影液的变通Golgi-Cox染色法是一种简单而有效的标记神经元树突棘的方法。     

A simple and improved method to generate human hybridomas.

By improving our previous method for production of human hybridomas, we developed a simple and remarkably efficient method for production of human hybridomas. We reformed our previous method in the following three points: (1) we added irradiated (30 Gy) myeloma cells as feeder cells to culture of fusion cells; (2) ouabain concentration in the selective medium was reduced from 2 x 10(-6) M to 1 x 10(-6) M; (3) selective medium (GIT-HAT-OL) was added to the culture after overnight cultivation of fusion cells. Consequently, we obtained higher fusion frequency (1/700 vs. 1/5500) compared with our previous method. By our present method, only so small number of human B cells (EBV-LCL) is required, so that the time necessary to establish human hybridomas is reduced.     

Insect cell technology is a versatile and robust vaccine manufacturing platform

Baculovirus and insect cell culture technologies have mostly been limited to research laboratories for the transient expression of target proteins for drug development purposes. With the renaissance of the vaccine field and the regulatory acceptance of recombinant DNA technology, the baculovirus expression system has been more broadly adopted for the development of subunit vaccines, including virus-like particles. In the numerous clinical trials extensively discussed and cross-referenced in this article, product quality, safety and efficacy have been demonstrated for many candidate vaccines targeting infectious diseases. The 2007 market authorization of Cervarix, a bivalent human papillomavirus virus-like particle vaccine against cervical cancer, was a critical milestone for the regulatory acceptance of insect cell technology in manufacturing human vaccines, opening the door to the approval of more baculovirus-derived vaccines. Insect cell technology is now a dominant platform for veterinary vaccines. This article covers the application of recombinant baculovirus as vectored vaccines to mediate systemic and mucosal immune responses through the display or expression of foreign antigens. We will probably observe increasingly more baculovirus-derived products and market licensing of safe and efficacious vaccines.     

A simple method for detecting antibodies to rubella.

A simple microplate method of enzyme linked immunosorbent assay for Rubella antibody is described. This Micro-ELISA was compared with haemagglutination inhibition in a study of 188 human sera. The total discrepancy rate between the two tests was only 3-7%.     

A simple,rapid method for detecting mycoplasma contamination

Methods in Cell Science -