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At least 37 records · Page 2Linked to original sources
PubMed1983

A new approach to the induction of duct epithelial hyperplasia and nesidioblastosis by cellophane wrapping of the hamster pancreas.

There is ample evidence that a relationship exists between duct epithelial hyperplasia and carcinoma of the pancreas. However, no experimental system exists to investigate the mechanisms involved. A new model is described in the Syrian golden hamster for inducing duct epithelial hyperplasia and nesidioblastosis. The head of the pancreas is wrapped with cellophane tape; ligation of the duct is not involved and there is no evidence of diffuse pancreatitis. Preliminary studies have revealed that this model results in periductal fibrosis in relation to the cellophane thus producing partial duct obstruction. Concomitant with the fibrosis there is duct epithelial hyperplasia in the head of the gland, while peripherally there is ductular proliferation and the initiation of nesidioblastosis. It is believed that this model will be of use in studies of pancreatic carcinogenesis and will thus enhance our knowledge of the interrelationships between etiologic factors, precursor lesions, and pancreatic cancer. This is of particular importance in the early recognition of this neoplasm in man.

Animals↗
PubMed1991

Cellophane--a dressing for split-thickness skin graft donor sites.

Cellophane paper has been used as a dressing for split-thickness skin graft donor sites in 251 patients between October 1985 and December 1989. Twelve donor sites in 10 patients were observed in detail to assess the usefulness of this material. The results of the study are presented and the merits and disadvantages of this dressing material have been discussed. In the opinion of the authors the cellophane paper dressing was found to be most satisfactory. It is also cheaper than the newly available dressing materials for the skin donor area.

Burns↗
PubMed1958

A cellophane-strip technique for culturing tissue in multipurpose culture chambers.

A new technique for the cultivation of living tissues in the multipurpose culture chamber is described. This procedure employs strips of cellophane as the agent for anchoring tissue explants to the coverslip walls of the chamber and disposes of the time-honored plasma-clot technique. The primary advance embodied in this procedure lies in the fact that cells emigrating from so-cultured explants manifest themselves in a highly differentiated manner comparable to the cells of origin, whereas the outgrowth from the same types of tissue in plasma clots results in a more undifferentiated type of growth. Comparisons of outgrowths from embryonic thyroid, bone, and muscle (chicken) are photographically documented, and attention is called to certain cytochemical methods which further corroborate the differentiated quality obtained with the cellophane-strip technique.

Bone and Bones↗
PubMed1989

The effect of cellophane wrapping of the pancreas in the Syrian golden hamster: autoradiographic observations.

We examined the effects of cellophane wrapping of the pancreas on the age-related uptake of tritiated thymidine (3H-TdR) by the differentiated cell types of the pancreas of the Syrian golden hamster. Fifty-two hamsters were studied. At 7 weeks of age, hamsters underwent cellophane wrapping (n = 32) or were allocated to a control group (n = 20). Animals 8-22 weeks of age (four at each interval) received 3H-TdR (2 microCi/g) intraperitoneally and were killed 1 h later. Pancreatic tissues from each animal was processed for autoradiography. The percent of acinar cells labeled with 3H-TdR at 8 weeks, in control and wrapped animals, was 1.17 +/- 0.26 and 1.51 +/- 0.38 respectively (p = N.S.). In control animals, this steadily diminished to 0.02 +/- 0.00 at 22 weeks. In wrapped animals, there was less of a tendency for acinar cell labeling to decrease with age, and the percent of labeled acinar cells in wrapped animals at 22 weeks was 0.05 +/- 0.00. The percent of ductular cells labeled with 3H-TdR at 8 weeks in control and wrapped animals was 0.24 +/- 0.24 and 0.98 +/- 0.24, respectively (p = N.S.), and at 22 weeks was 0.13 +/- 0.90 and 0.60 +/- 0.03, respectively (p less than 0.01). The percent of islet cells labeled with 3H-TdR at 8 weeks in control and wrapped animals was 0.16 +/- 0.01 and 0.42 +/- 0.01, respectively (p less than 0.05), and at 22 weeks was 0.18 +/- 0.01 and 0.63 +/- 0.05 (p less than 0.05), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Systemic and regional haemodynamic profile of captopril in conscious rabbits with bilateral cellophane perinephritis hypertension.

The radioactive microsphere technique was used to study the systemic and regional haemodynamic effects of the converting enzyme inhibitor captopril (0.1, 0.3 and 1.0 mg/kg) 10 min after intravenous administration in conscious rabbits with bilateral cellophane perinephritis hypertension, an experimental model of hypertension associated with normal plasma renin levels. Captopril lowered arterial blood pressure as a result of a dose-dependent decrease in total peripheral resistance. The fall in blood pressure was accompanied by an increase in cardiac output after the second and third dose of captopril; heart rate was not significantly altered. Captopril produced a generalized peripheral vasodilatation; the changes in vascular conductance being most pronounced in the kidneys, intestines and skin which resulted in a significant increase in blood flow to these vascular beds. The effective antihypertensive properties of captopril in this 'low plasma renin' model of hypertension and the uniform increase in vascular conductances produced by captopril, which antagonizes the generalized increase in vascular resistances that characterizes cellophane perinephritis hypertension, may indicate the involvement of an increased activity of the renin-angiotensin system, possibly in tissues, such as the vascular wall and brain, in the maintenance of the elevated blood pressure in this hypertensive form.

Animals↗
PubMed2005

Hypertension in Page (cellophane-wrapped) kidney is due to interstitial nephritis.

BACKGROUND: Cellophane wrapping of the kidneys (Page kidney) induces perinephrits and hypertension, assumed to be due to renal ischemia resulting from parenchymal compression by the fibrous hull surrounding the kidneys. We investigated if interstitial nephritis, rather than plasma angiotensin activity, played a role in the development of hypertension in the Page kidney model. METHODS: We followed for 7 weeks rats with bilateral cellophane wrapping of the kidneys that received 20 mg/kg/day of the immunosuppressive antiproliferative drug mycophenolate mofetil (MMF) (two-kidney wrap/MMF) (N = 10) or vehicle (two-kidney wrap) (N = 10), and sham-operated rats (N = 10). RESULTS: The two-kidney wrap group had progressive increment in blood pressure, inflammatory damage occupying 25% to 50% of the renal tubulointerstitial region and increased number of angiotensin II-positive cells, angiotensin II content, and oxidative stress in the kidney. MMF treatment prevented the development of hypertension and renal inflammation without modifying the perinephritic hull or the increment it induced in the intrarenal pressure. The plasma levels of angiotensin II were similar in the two-kidney wrap group, the two-kidney wrap/MMF group and the sham-operated animals and unchanged from baseline, despite the blood pressure increase in the two-kidney wrap group. CONCLUSION: Our results indicate that renal wrap hypertension is unrelated to plasma angiotensin II levels and related to the inflammatory damage caused by the external compression of the kidney.

Angiotensin II↗
PubMed2002

Cellophane banding of congenital intrahepatic portosystemic shunts in two Irish wolfhounds.

Two three-month-old, male Irish wolfhound siblings were diagnosed with breed-typical left divisional congenital intrahepatic portosystemic shunts consistent with patent ductus venosus. The shunts were amenable to surgical dissection at a posthepatic location. Both dogs had cellophane banding for shunt attenuation. One dog was euthanased after developing post-ligation neurological dysfunction, which was refractory to treatment. The other dog survived and demonstrated shunt attenuation. Successful surgical management using cellophane banding of a patent ductus venosus has not been previously described in a large-breed dog.

Animals↗
PubMed1965

STUDIES ON THE "CARRY-OVER" OF ANTIBIOTICS USING THE CELLOPHANE TRANSFER TECHNIQUE.

The cellophane transfer technique has been used in the clinical laboratory as a guide to combined treatment and also to study the bactericidal actions of all common antibiotics, but during recent work it became clear that some antibiotics are absorbed on to the cellophane and enough may be carried through on to the fresh medium to inhibit growth of survivors even after transfer. The present investigation has been made to determine the maximum concentrations which can be used without risk of inhibition by carry-over Certain concentrations are recommended and also the depth of agar, and with this there should be no risk of invalidating these bactericidal tests by bacteriostatic inhibition of survivors of carry-over. In clinical studies it is usually only necessary to test one of each group of antibiotics. That showing least carry-over should be used.

Agar↗
PubMed1981

Cellophane perinephritic hypertension in the dog: some biochemical, hemodynamic and pathological characteristics.

Perinephritic hypertension was induced in mongrel dogs by cellophane encapsulation of one kidney and simultaneous contralateral nephrectomy. Systolic blood pressure began to rise before diastolic blood pressure and both reached maximal values 3 weeks after surgery, their levels becoming stable thereafter up to the end of the study (20 weeks). Cardiac contractility, measured by the index dp/dt/P40 (rate of rise of isovolumic left intraventricular pressure at a developed left ventricular pressure of 40 mm Hg) was not altered during the evolution of hypertension; heart weight and left ventricular thickness were increased. Plasma renin activity markedly decreased in the chronic phase and plasma urea and creatinine levels rised initially in a moderate but significant way, thereafter remaining stable. The structure of the wrapped kidney remained normal 20 weeks after surgery, when microscopic arterial lesions were seen in other organs. The comparison of the evolution of this hypertensive model with other more commonly used renal experimental hypertension types allows us to conclude that cellophane perinephritic hypertension in the dog must be considered as an individual entity.

Animals↗
PubMed2002

Cellophane based mini-prep method for DNA extraction from the filamentous fungus Trichoderma reesei.

BACKGROUND: Methods for the extraction of DNA from filamentous fungi are frequently laborious and time consuming because most of the available protocols include maceration in liquid nitrogen after the mycelium has been grown in a liquid culture. This paper describes a new method to replace those steps, which involves the growth of the mycelium on cellophane disks overlaid on solid medium and the use of glass beads for cell wall disruption. RESULTS: Extractions carried out by this method provided approximately 2 microg of total DNA per cellophane disk for the filamentous fungus Trichoderma reesei. To assess the DNA's quality, we made a PCR (Polymerase Chain Reaction) amplification of a gene introduced by a transformation in this fungus's genome (hph gene), with successful results. We also confirmed the quality of the DNA by the use of Southern blotting to analyze the presence of the same gene, which was easily detected, resulting in a sharply defined and strong band. CONCLUSIONS: The use of this method enabled us to obtain pure DNA from Trichoderma reesei, dispensing with the laborious and time-consuming steps involved in most protocols. The DNA obtained was found to be suitable for PCR and Southern blot analyses. Another advantage of this method is the fact that several samples can be processed simultaneously, growing the fungus on multiple well cell culture plates. In addition, the absence of maceration also reduces sample handling, minimizing the risks of contamination, a particularly important factor in work involving PCR.

Cell Wall↗
PubMed1993

Growth estimation of solid-state koji by covering a cellophane membrane on the mash.

In a solid-substrate fermentation system, fungal growth within a solid mash is an important index for the efficiency of the saccharification and production of metabolites. Estimation of fungal mass in such a heterogeneous solid-substrate systems is difficult and tedious. In this work, the comparison of Aspergillus oryzae which is a common strain for the wine-brewing process cultured on a cellophane membrane placed on a koji juice agar medium and a small scale of steamed rice koji culture was conduted. Experimental results showed that the cellophane membrane technique resembled the steamed rice koji culture and is considered as a convenient and effective way for investigating the growth characteristics and cytology for solid-substrate koji system.

Journal Article↗
PubMed1989

Foreign body reaction against cellophane in the athymic nude mice.

There are no differences in the multinucleate cell formation in normal and athymic mice after the subcutaneous implantation of a cellophane strip. The number of Ia+ epitheloid cells and multinucleate foreign body giant cells was lower and the number of epitheloid cells sharing the marker of activated macrophages (M 57) was higher in athymic compared to normal mice. The epitheloid cells of athymic and euthymic animals exhibited no difference in the expression of Mac-2 molecule. The difference of the expression of surface markers between athymic and euthymic animals does not influence the foreign body giant cell formation.

Animals↗
PubMed1984

Analysis of mu DNA replicated on cellophane discs.

We have presented restriction analyses which indicate that the first transposition event after induction can be carried out and analyzed in vitro using cellophane disc lysates. This would be a first step in describing in molecular terms a "wiring diagram" of replicative transposition.

Bacteriophage mu↗
PubMed1979

Permeability of cellophane membranes to parotid during dialysis.

Pooled paratoid saliva was dialyzed in cellophane membranes against water for periods of up to 1 week and loss of proteins was monitored by acrylamide gel-electrophoresis. A gradual loss of cationic proteins was observed whereas anionic proteins were not appreciably affected. Loss of the cationic proteins could be greatly reduced by performing dialyses against dilute electrolyte solutions rather than water. These effects were attributed primarily to electrostatic changes associated with the dialysis membranes.

Adult↗
PubMed1982

Role of diffusion potential on the flow of angiotensin II, bradykinin and related molecules through cellophane membranes.

The diffusion of electrically charged peptides (angiotensin II, bradykinin and [Suc1]angiotensin II) across tight cellophane membranes, obtained by different degrees of acetylation, shows a kinetic behaviour which was interpreted in the literature as indicative of the existence of different molecular conformations presenting slow interconversion velocities and different permeabilities across the membrane. A diffusion potential (delta psi) was found to be present across the membrane along diffusion experiments performed in low ionic strength. Upon annihilation of delta psi by chemical voltage clamping (by equally increasing the ionic strength on both bathing solutions) the diffusion rate was decreased and the flow followed first order kinetics, indicating a major role of delta psi in the process. As the ionic strength increase could also affect molecular conformation, the role of delta psi on the diffusion of those molecules was tested by fitting flux and delta psi experimental results by an integrated form of Nernst-Planck flux equation. It is concluded that the deviation from first order diffusion kinetics, observed in low ionic strength, is solely due to the diffusion potential, and not to the existence of more than one molecular conformation in aqueous solution. This study was extended to amino acids and other related charged molecules.

Angiotensin II↗
PubMed1990

Plasmid transformation of Bacillus cereus on cellophane membranes.

A simple approach to test the ability of bacteria to undergo natural genetic transformation is suggested. The basic feature of the approach is the cultivation of bacterial cells in the presence of exogenous (plasmid) DNA on cellophane membranes placed successively on nutrient and selective agar. Using this approach the ability of Bacillus cereus for "natural" genetic transformation was detected. Transformation frequencies varied from 10(-8) to 10(-6).

Bacillus cereus↗
PubMed1978

In vitro transcription in E. coli crude lysates prepared on cellophane discs.

An in vitro RNA-synthesizing system consisting of gently lysed E. coli cells on cellophane discs is described. The system has been optimalized with respect to total RNA synthesis. Under certain standard conditions DNA dependent RNA polymerase (EC 2.7.7.6) is responsible for the majority of the RNA synthesis. The extensive rifampicin sensitivity of the synthesis indicates that most of the transcripts are initiated in vitro. The RNA synthesizing system described here has been developed with the aim of studying phage transcription in vitro. We show here that lysates of a P4 infected P2 lysogen support initiation and propagation of transcription from the P2 prophage.

Cellophane↗
PubMed2002

Structural factors increase blood pressure through the interaction of resistance vessel geometry with neurohumoral and local factors: estimates in rabbits with renal cellophane-wrap hypertension with intact effectors and during neurohumoral blockade.

BACKGROUND: The structural changes in hypertension include narrowing of the lumen of the large resistance vessels and an increase in their wall thickness : lumen ratio. Their haemodynamic role has been controversial. OBJECTIVE: To examine resting haemodynamics and the responses to graded drug-induced changes in tone in renal cellophane-wrap (wrap) and sham-operated (sham) rabbits, when their neurohumoral effectors were intact and during high-level blockade. METHODS: Each rabbit was implanted with a flow probe for measuring cardiac output, had catheters inserted for drug infusions, and underwent mean arterial pressure (MAP) measurements. Resting values were determined and we infused graded doses of dilator and constrictor drugs: acetylcholine or adenosine; angiotensin II or methoxamine. The dilator and constrictor dose-response curves were combined into a single relationship for MAP, cardiac output, total peripheral conductance (TPC) and heart rate; total peripheral resistance (TPR) was estimated as 1/TPC. RESULTS: Throughout the range of vascular tone and with intact effector function, MAP was greater and TPC lower in wrap than in sham rabbits, and cardiac output was the same in both groups. The ratios of wrap : sham slopes of the log dose-response regression lines were 0.47 for TPC, 2.04 for TPR and 1.89 for MAP. Thus MAP and TPR responses were enhanced to the same degree in wrap rabbits. During neurohumoral block, baroreflex-mediated heart rate responses were abolished. In addition, resting vascular tone was lower than with intact effectors in both wrap and sham rabbits; however, the ratios of wrap : sham slopes for TPC and TPR were similar to those with intact effectors, whereas the ratio for the slope for MAP was slightly smaller, although still enhanced. CONCLUSION: In wrap hypertension, the enhanced MAP and TPR responses are in accord with an interaction between vascular geometry and the sum of altered neurohumoral + local activity, plus a rarefaction component.

Adenosine↗