Tissue culture studies; standardization of techniques for quantitative culturing

Reproducible conditions have been described for quantitative tissue culturing in which all constituents including the tissue itself are added in known quantities to the culture. The conditions for transfer, cutting, and manipulation of tissue are also described. The data show that such culturing can be performed without loss or significant alteration of the nitrogen and phosphorus content of the tissue.     

Light and electron microscopic study of crocodile islets of Langerhans

The tissue of the islets of Langerhans was studied in Alligator mississippiensis and Caiman niger. The distribution of the insular tissue in the pancreas was described from the picture in the light microscope, together with the incidence of characteristic islets, which frequently surround the duct tress, and of scattered insular cells. Five types of endocrine cells, distinguishable by their staining properties and typical electron microscopic image, were described in the insular tissue. In addition to A-, B- and D-cells, others which very probably correspond to EC- and PP-cells are described. Mixed cells were also found. The pancreatic interstitial connective tissue contains large numbers of nerve fibre bundles; isolated nerve fibres may penetrate to the insular cells. At the site of contact of a nerve ending with an endocrine cell, characteristic thickening of the membranes is sometimes found.     

A radioenzymatic method for the determination of tissue 10-formyltetrahydrofolate

A radioenzymatic method for the determination of tissue 10-formyltetrahydrofolate is described based on the stable ternary complex formed from methylenetetrahydrofolate, tritiated fluorodeoxyuridylate and thymidylate synthase. Tissue extract 10-formyltetrahydrofolate is deacylated with 10-formyltetrahydrofolate deacylase and the tetrahydrofolate formed is converted to methylenetetrahydrofolate using formaldehyde. Mouse tissue 10-formyltetrahydrofolate levels and their stability to extraction procedures are described.     

Determinations of adipose cell size and number in suspensions of isolated rat and human adipose cells

The osmic acid fixation-Coulter electronic counter method described for determining adipose cell size and number in intact adipose tissue fragments has been modified for use with suspensions of isolated rat and human adipose cells. Mean cell sizes in tissue fragments and isolated cell suspensions prepared from the same tissue are virtually identical in rats of various weights. No statistically significant difference in mean adipose cell size between tissue and isolated cell suspension was observed in human adipose tissue although the variability was much greater than in rat tissue. The distribution of cell sizes among replicate samples is more uniform in the isolated cell preparations, possibly reflecting the considerably larger quantities of tissue used in preparing isolated cells than in determining cell size and number directly from tissue fragments. An example of the utility of the modified method during routine metabolic studies with isolated rat epididymal adipose cells is described; isolated cells of increasing size can be obtained from rats of increasing body weight, or from the separated distal and proximal portions of the fat pads of rats of the same weight.     

The emergence and pitfalls of international tissue banking

The rapid growth of tissue banking and associated international organisations following the fall of the Berlin wall in 1991 is described. This surge in collaboration led to a world-wide constructive movement to use and to produce human tissues. As the years progressed industrialisation, led by the USA, improved the quality of tissue allografts but led higher costs and consolidation within the developing industry. The growth of litigation more than kept pace with the industrial progress. One landmark case is described, the outcome of which could revolutionise the current practices now applied to eliminate possible viral contamination of implanted tissue grafts.     

Hexachrome Modification of Movat's Stain

A less than three-hour hexachrome modification of Movat's pentachrome stain is described, its various steps discussed, and its principal uses in histopathology presented. The hexachrome procedure consistently yields good results, with excellent and colorful differentiation of muscle, various connective tissue components, mucinous secretions and intra-cytoplasmic structures in human and animal tissues obtained surgically or at autopsy. Alternative abbreviated procedures for muscle-connective tissue differential staining and for study of nuclear detail are also described.     

Recovery of Dengue Viruses from Tissues of Experimentally Infected Rhesus Monkeys

A tissue explant culture technique for the recovery of dengue virus from experimentally infected monkey tissue is described and compared with tissue culture assay of tissue triturates and co-cultivation of trypsinized cells in cell cultures. The most efficient technique was one in which minced tissue was explanted in co-culture with dengue virus-susceptible LLC-MK2 monkey kidney cells. This technique shows promise of being useful for detection of virus in autopsy material from fatal dengue hemorrhagic fever cases.     

Hexachrome modification of Movat's stain.

A less than three-hour hexachrome modification of Movat's pentachrome stain is described, its various steps discussed, and its principal uses in histopathology presented. The hexachrome procedure consistently yields good results, with excellent and colorful differentiation of muscle, various connective tissue components, mucinous secretions and intra-cytoplasmic structures in human and animal tissues obtained surgically or at autopsy. Alternative abbreviated procedures for muscle-connective tissue differential staining and for study of nuclear detail are also described.     

Synchrotron radiation-induced formation and reactions of free radicals in human acellular dermal matrix

The present work characterizes the formation of free radicals in an implantable human acellular dermal tissue (Alloderm, LifeCell Corp., Branchburg, NJ) upon irradiation. The tissue was preserved in a vitreous carbohydrate matrix by freeze-drying. Freeze-dried samples were irradiated using a synchrotron light source, and free radicals generated were investigated using the electron paramagnetic resonance (EPR) technique. At least two free radical populations, with g factors of 1.993 (approximately 43%) and 2.002 (approximately 57%), respectively, were identified in the irradiated tissue. The transformation (reaction) kinetics of free radicals produced was investigated in the presence of nitrogen, oxygen and moisture. The reaction kinetics of free radicals was extremely slow in the nitrogen environment. The presence of oxygen and moisture greatly accelerated free radical reactions in the tissue matrix. The reaction of free radicals could not be described by traditional reaction kinetics. A dispersive kinetics model and a diffusion model were developed to analyze the reaction kinetics in the present study. The dispersive model took into consideration molecular mobility and dispersivity of free radicals in the heterogeneous tissue material. The diffusion model described the radical reaction kinetics as two parallel and simultaneous processes: a first-order fast kinetics mainly on tissue surface and a diffusion-limited slow kinetics in deeper layers of the tissue matrix. Both models described quantitative experimental data well. Further investigation is needed to verify whether any of these two models or concepts describes the inherent radical reaction kinetics in the solid tissue matrix.     

蕨类植物组织培养研究进展(综述)

蕨类植物组织培养可分为以孢子为外植体的无菌播种和以孢子体为外植体进行的组织培养.本文简要介绍国内外蕨类植物组织培养研究概况,综述培养基成份、培养方式及培养条件对组织培养过程中生长发育的影响,同时介绍蕨类植物组织培养中世代转换的诱导及调控.     

Extraction of peptides from guanidine thiocyanate homogenates used to isolate RNA

A method is described in which the concentrated tissue extract that remains after preparation of RNA in guanidine thiocyanate can be salvaged for simultaneous measurements of neuropeptides by RIA and other neuroactive factors by bioassay. This procedure may be used for assessing alterations in tissue peptide content in addition to mRNA changes in the same tissue sample.     

Studies on the pituitary "fettstoffwechselhormon". VI. Preparation of two highly purified lipolytic active peptides from hog pituitary glands.

The preparation of two highly purified lipolytically active hog pituitary peptides, called P-LF II C and P-LF II D is described. The two peptides are free of other pituitary hormone activities. In isolated rat and porcine adipose tissue, both fractions are lipolytically much more active than every other lipolytic active pituitary peptide described to date. By fraction P-LF II D, the first pituitary peptide was isolated which has lipolytic activity in isolated rat adipose tissue than corticotropin, the lipolytically most active pituitary hormone known so far. On isolated porcine adipose tissue, fraction P-LF II D as well as P-LF II C showed without doubt higher activity than corticotropin.     

On the histochemistry of epimerases

Summary A histochemical method for hydroxyproline epimerase together with its mechanism of enzymatic action is described. The epimerase is studied in different tissues and organs. The data resulting from the investigation reveal a particular epimerase activity in connective tissue and skeletal muscular tissue.     

"Apple coring" the nipple in subcutaneous mastectomy

A simple technique is described for removing the ductal tissue from the nipple in a subcutaneous mastectomy. We believe that complete removal of all the ductal tissue is desirable in this operation, and that it will also decrease the incidence of subsequent infection. The operative technique, the problems, the advantages, and the disadvantages of the procedure are described.     

The absorption and accumulation of solutes by living plant cells

In a previous paper (25) one of us (F.C.S.) has pointed out that accumulation of certain inorganic electrolytes by immersed potato tissue from dilute solutions is determined by those variables which also limit the aërobic respiration of the tissue. In order to understand fully the salt absorption by such tissues it is clearly imperative to know their respiratory behaviour under conditions identical with those adopted for the absorption work. A technique has already been described (26) which enables this to be done with adequate control of all the known variables which affect the respiration and salt accumulation of immersed storage tissue. The methods utilised in this paper were exclusively those already described.     

New device for preparing thin slices of adipose tissue for metabolic studies in vitro

A new microtome is described which allows the rapid preparation of equal slices of well-defined thickness of fresh human tissue, especially adipose tissue. Presetting the microtome for a section thickness of 500 micro m, we found a variation of about 5% with human adipose tissue. Slices of human adipose tissue sliced by the microtome showed a higher sensitivity to insulin and a better reproducibility of results than slices prepared freehand.     

The laser in the Lowry technique for microdissection of freeze-dried tissue slices

Synopsis A new technique for tissue microdissection is described. This procedure, using an u.v.-laser micropreparation instrument, overcomes the extremely timeconsuming manual preparation. The u.v.-laser micropreparation design allows fast, precise, reproducible and smear-contamination-free tissue microdissection. The preparation of the tissue sample can be programmed by tracing out the area to be sampled with a non-destructive 0.5 m W He-Ne-laser aiming-beam. The trace is stored in a small electronic unit, which then guides the motor-driven stepping stage on the microscope in the actual dissection run with the u.v.-laser.The laser power is adjustable in the range 4 to 40 kW and controlled by a photo diode displayed on an oscilloscope screen. In the tissue slice, prepared according to Lowry, an unlimited number of cells or tissue compartments can be dissected and afterwards weighed. The procedure described offers a broader use of the quantitative microhistochemical techniques of Lowry and of Neuhoff.Paper given at the Royal Microscopical Society's European Histochemistry Meeting at Nottingham in September, 1975.     

A new device for the freeze-clamping of tissue samples

Measurement of metabolite concentrations in tissue samples involves the following procedures: Removal of the sample from the animal, temporary arrest of metabolism, extraction (including weighing, homogenization, final fixation, and neutralization) and assay. Rapid temporary fixation following the sampling of tissue is essential to prevent autolytic changes in metabolite concentrations (1,2). The freeze-clamping technique described by Wollenberger et al. (3) meets this requirement as long as the final thickness of the freeze-clamped sample is sufficiently small. For brain tissue the limit seems to be about 2 mm (4).In our laboratory we have made extensive use of the freeze-clamping tongs of Wollenberger et al., especially for small tissue samples freeze-clamped in situ. However, when in situ clamping can not be used when more than 2–3 g of tissue must be sampled, the freeze-clamping press described below has proven very useful.     

Observations on a tissue response within the body cavity of fish infected with the plerocercoid larvae of Ligula intestinalis (L.) (Cestoda: Pseudophyllidea)

Infection of certain species of cyprinid fish with the plerocercoid larva of the cestode Ligula intestinalis is accompanied by a host tissue response.
The tissue reaction is evident in roach Rutilus rutilus as young as three months. An initial cellular infiltration is followed by the laying down of sheets of connective tissue. A case of calcification is described in a single infected rudd Scardinius erythrophthalmus .